drm/i915/skl: Fix has_ipc on skl and document WaDisableIPC.

[mirror_ubuntu-bionic-kernel.git] / drivers / gpu / drm / i915 / intel_pm.c

/*
 * Copyright © 2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eugeni Dodonov <eugeni.dodonov@intel.com>
 *
 */

#include <linux/cpufreq.h>
#include <drm/drm_plane_helper.h>
#include "i915_drv.h"
#include "intel_drv.h"
#include "../../../platform/x86/intel_ips.h"
#include <linux/module.h>
#include <drm/drm_atomic_helper.h>

/**
 * DOC: RC6
 *
 * RC6 is a special power stage which allows the GPU to enter an very
 * low-voltage mode when idle, using down to 0V while at this stage.  This
 * stage is entered automatically when the GPU is idle when RC6 support is
 * enabled, and as soon as new workload arises GPU wakes up automatically as well.
 *
 * There are different RC6 modes available in Intel GPU, which differentiate
 * among each other with the latency required to enter and leave RC6 and
 * voltage consumed by the GPU in different states.
 *
 * The combination of the following flags define which states GPU is allowed
 * to enter, while RC6 is the normal RC6 state, RC6p is the deep RC6, and
 * RC6pp is deepest RC6. Their support by hardware varies according to the
 * GPU, BIOS, chipset and platform. RC6 is usually the safest one and the one
 * which brings the most power savings; deeper states save more power, but
 * require higher latency to switch to and wake up.
 */
#define INTEL_RC6_ENABLE                        (1<<0)
#define INTEL_RC6p_ENABLE                       (1<<1)
#define INTEL_RC6pp_ENABLE                      (1<<2)

static void gen9_init_clock_gating(struct drm_i915_private *dev_priv)
{
        if (HAS_LLC(dev_priv)) {
                /*
                 * WaCompressedResourceDisplayNewHashMode:skl,kbl
                 * Display WA#0390: skl,kbl
                 *
                 * Must match Sampler, Pixel Back End, and Media. See
                 * WaCompressedResourceSamplerPbeMediaNewHashMode.
                 */
                I915_WRITE(CHICKEN_PAR1_1,
                           I915_READ(CHICKEN_PAR1_1) |
                           SKL_DE_COMPRESSED_HASH_MODE);
        }

        /* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
        I915_WRITE(CHICKEN_PAR1_1,
                   I915_READ(CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);

        I915_WRITE(GEN8_CONFIG0,
                   I915_READ(GEN8_CONFIG0) | GEN9_DEFAULT_FIXES);

        /* WaEnableChickenDCPR:skl,bxt,kbl,glk,cfl */
        I915_WRITE(GEN8_CHICKEN_DCPR_1,
                   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);

        /* WaFbcTurnOffFbcWatermark:skl,bxt,kbl,cfl */
        /* WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl */
        I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
                   DISP_FBC_WM_DIS |
                   DISP_FBC_MEMORY_WAKE);

        /* WaFbcHighMemBwCorruptionAvoidance:skl,bxt,kbl,cfl */
        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
                   ILK_DPFC_DISABLE_DUMMY0);

        if (IS_SKYLAKE(dev_priv)) {
                /* WaDisableDopClockGating */
                I915_WRITE(GEN7_MISCCPCTL, I915_READ(GEN7_MISCCPCTL)
                           & ~GEN7_DOP_CLOCK_GATE_ENABLE);
        }
}

static void bxt_init_clock_gating(struct drm_i915_private *dev_priv)
{
        gen9_init_clock_gating(dev_priv);

        /* WaDisableSDEUnitClockGating:bxt */
        I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
                   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);

        /*
         * FIXME:
         * GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ applies on 3x6 GT SKUs only.
         */
        I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
                   GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ);

        /*
         * Wa: Backlight PWM may stop in the asserted state, causing backlight
         * to stay fully on.
         */
        I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
                   PWM1_GATING_DIS | PWM2_GATING_DIS);
}

static void glk_init_clock_gating(struct drm_i915_private *dev_priv)
{
        u32 val;
        gen9_init_clock_gating(dev_priv);

        /*
         * WaDisablePWMClockGating:glk
         * Backlight PWM may stop in the asserted state, causing backlight
         * to stay fully on.
         */
        I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
                   PWM1_GATING_DIS | PWM2_GATING_DIS);

        /* WaDDIIOTimeout:glk */
        if (IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1)) {
                u32 val = I915_READ(CHICKEN_MISC_2);
                val &= ~(GLK_CL0_PWR_DOWN |
                         GLK_CL1_PWR_DOWN |
                         GLK_CL2_PWR_DOWN);
                I915_WRITE(CHICKEN_MISC_2, val);
        }

        /* Display WA #1133: WaFbcSkipSegments:glk */
        val = I915_READ(ILK_DPFC_CHICKEN);
        val &= ~GLK_SKIP_SEG_COUNT_MASK;
        val |= GLK_SKIP_SEG_EN | GLK_SKIP_SEG_COUNT(1);
        I915_WRITE(ILK_DPFC_CHICKEN, val);
}

static void i915_pineview_get_mem_freq(struct drm_i915_private *dev_priv)
{
        u32 tmp;

        tmp = I915_READ(CLKCFG);

        switch (tmp & CLKCFG_FSB_MASK) {
        case CLKCFG_FSB_533:
                dev_priv->fsb_freq = 533; /* 133*4 */
                break;
        case CLKCFG_FSB_800:
                dev_priv->fsb_freq = 800; /* 200*4 */
                break;
        case CLKCFG_FSB_667:
                dev_priv->fsb_freq =  667; /* 167*4 */
                break;
        case CLKCFG_FSB_400:
                dev_priv->fsb_freq = 400; /* 100*4 */
                break;
        }

        switch (tmp & CLKCFG_MEM_MASK) {
        case CLKCFG_MEM_533:
                dev_priv->mem_freq = 533;
                break;
        case CLKCFG_MEM_667:
                dev_priv->mem_freq = 667;
                break;
        case CLKCFG_MEM_800:
                dev_priv->mem_freq = 800;
                break;
        }

        /* detect pineview DDR3 setting */
        tmp = I915_READ(CSHRDDR3CTL);
        dev_priv->is_ddr3 = (tmp & CSHRDDR3CTL_DDR3) ? 1 : 0;
}

static void i915_ironlake_get_mem_freq(struct drm_i915_private *dev_priv)
{
        u16 ddrpll, csipll;

        ddrpll = I915_READ16(DDRMPLL1);
        csipll = I915_READ16(CSIPLL0);

        switch (ddrpll & 0xff) {
        case 0xc:
                dev_priv->mem_freq = 800;
                break;
        case 0x10:
                dev_priv->mem_freq = 1066;
                break;
        case 0x14:
                dev_priv->mem_freq = 1333;
                break;
        case 0x18:
                dev_priv->mem_freq = 1600;
                break;
        default:
                DRM_DEBUG_DRIVER("unknown memory frequency 0x%02x\n",
                                 ddrpll & 0xff);
                dev_priv->mem_freq = 0;
                break;
        }

        dev_priv->ips.r_t = dev_priv->mem_freq;

        switch (csipll & 0x3ff) {
        case 0x00c:
                dev_priv->fsb_freq = 3200;
                break;
        case 0x00e:
                dev_priv->fsb_freq = 3733;
                break;
        case 0x010:
                dev_priv->fsb_freq = 4266;
                break;
        case 0x012:
                dev_priv->fsb_freq = 4800;
                break;
        case 0x014:
                dev_priv->fsb_freq = 5333;
                break;
        case 0x016:
                dev_priv->fsb_freq = 5866;
                break;
        case 0x018:
                dev_priv->fsb_freq = 6400;
                break;
        default:
                DRM_DEBUG_DRIVER("unknown fsb frequency 0x%04x\n",
                                 csipll & 0x3ff);
                dev_priv->fsb_freq = 0;
                break;
        }

        if (dev_priv->fsb_freq == 3200) {
                dev_priv->ips.c_m = 0;
        } else if (dev_priv->fsb_freq > 3200 && dev_priv->fsb_freq <= 4800) {
                dev_priv->ips.c_m = 1;
        } else {
                dev_priv->ips.c_m = 2;
        }
}

static const struct cxsr_latency cxsr_latency_table[] = {
        {1, 0, 800, 400, 3382, 33382, 3983, 33983},    /* DDR2-400 SC */
        {1, 0, 800, 667, 3354, 33354, 3807, 33807},    /* DDR2-667 SC */
        {1, 0, 800, 800, 3347, 33347, 3763, 33763},    /* DDR2-800 SC */
        {1, 1, 800, 667, 6420, 36420, 6873, 36873},    /* DDR3-667 SC */
        {1, 1, 800, 800, 5902, 35902, 6318, 36318},    /* DDR3-800 SC */

        {1, 0, 667, 400, 3400, 33400, 4021, 34021},    /* DDR2-400 SC */
        {1, 0, 667, 667, 3372, 33372, 3845, 33845},    /* DDR2-667 SC */
        {1, 0, 667, 800, 3386, 33386, 3822, 33822},    /* DDR2-800 SC */
        {1, 1, 667, 667, 6438, 36438, 6911, 36911},    /* DDR3-667 SC */
        {1, 1, 667, 800, 5941, 35941, 6377, 36377},    /* DDR3-800 SC */

        {1, 0, 400, 400, 3472, 33472, 4173, 34173},    /* DDR2-400 SC */
        {1, 0, 400, 667, 3443, 33443, 3996, 33996},    /* DDR2-667 SC */
        {1, 0, 400, 800, 3430, 33430, 3946, 33946},    /* DDR2-800 SC */
        {1, 1, 400, 667, 6509, 36509, 7062, 37062},    /* DDR3-667 SC */
        {1, 1, 400, 800, 5985, 35985, 6501, 36501},    /* DDR3-800 SC */

        {0, 0, 800, 400, 3438, 33438, 4065, 34065},    /* DDR2-400 SC */
        {0, 0, 800, 667, 3410, 33410, 3889, 33889},    /* DDR2-667 SC */
        {0, 0, 800, 800, 3403, 33403, 3845, 33845},    /* DDR2-800 SC */
        {0, 1, 800, 667, 6476, 36476, 6955, 36955},    /* DDR3-667 SC */
        {0, 1, 800, 800, 5958, 35958, 6400, 36400},    /* DDR3-800 SC */

        {0, 0, 667, 400, 3456, 33456, 4103, 34106},    /* DDR2-400 SC */
        {0, 0, 667, 667, 3428, 33428, 3927, 33927},    /* DDR2-667 SC */
        {0, 0, 667, 800, 3443, 33443, 3905, 33905},    /* DDR2-800 SC */
        {0, 1, 667, 667, 6494, 36494, 6993, 36993},    /* DDR3-667 SC */
        {0, 1, 667, 800, 5998, 35998, 6460, 36460},    /* DDR3-800 SC */

        {0, 0, 400, 400, 3528, 33528, 4255, 34255},    /* DDR2-400 SC */
        {0, 0, 400, 667, 3500, 33500, 4079, 34079},    /* DDR2-667 SC */
        {0, 0, 400, 800, 3487, 33487, 4029, 34029},    /* DDR2-800 SC */
        {0, 1, 400, 667, 6566, 36566, 7145, 37145},    /* DDR3-667 SC */
        {0, 1, 400, 800, 6042, 36042, 6584, 36584},    /* DDR3-800 SC */
};

static const struct cxsr_latency *intel_get_cxsr_latency(bool is_desktop,
                                                         bool is_ddr3,
                                                         int fsb,
                                                         int mem)
{
        const struct cxsr_latency *latency;
        int i;

        if (fsb == 0 || mem == 0)
                return NULL;

        for (i = 0; i < ARRAY_SIZE(cxsr_latency_table); i++) {
                latency = &cxsr_latency_table[i];
                if (is_desktop == latency->is_desktop &&
                    is_ddr3 == latency->is_ddr3 &&
                    fsb == latency->fsb_freq && mem == latency->mem_freq)
                        return latency;
        }

        DRM_DEBUG_KMS("Unknown FSB/MEM found, disable CxSR\n");

        return NULL;
}

static void chv_set_memory_dvfs(struct drm_i915_private *dev_priv, bool enable)
{
        u32 val;

        mutex_lock(&dev_priv->rps.hw_lock);

        val = vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2);
        if (enable)
                val &= ~FORCE_DDR_HIGH_FREQ;
        else
                val |= FORCE_DDR_HIGH_FREQ;
        val &= ~FORCE_DDR_LOW_FREQ;
        val |= FORCE_DDR_FREQ_REQ_ACK;
        vlv_punit_write(dev_priv, PUNIT_REG_DDR_SETUP2, val);

        if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2) &
                      FORCE_DDR_FREQ_REQ_ACK) == 0, 3))
                DRM_ERROR("timed out waiting for Punit DDR DVFS request\n");

        mutex_unlock(&dev_priv->rps.hw_lock);
}

static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
{
        u32 val;

        mutex_lock(&dev_priv->rps.hw_lock);

        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
        if (enable)
                val |= DSP_MAXFIFO_PM5_ENABLE;
        else
                val &= ~DSP_MAXFIFO_PM5_ENABLE;
        vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);

        mutex_unlock(&dev_priv->rps.hw_lock);
}

#define FW_WM(value, plane) \
        (((value) << DSPFW_ ## plane ## _SHIFT) & DSPFW_ ## plane ## _MASK)

static bool _intel_set_memory_cxsr(struct drm_i915_private *dev_priv, bool enable)
{
        bool was_enabled;
        u32 val;

        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
                was_enabled = I915_READ(FW_BLC_SELF_VLV) & FW_CSPWRDWNEN;
                I915_WRITE(FW_BLC_SELF_VLV, enable ? FW_CSPWRDWNEN : 0);
                POSTING_READ(FW_BLC_SELF_VLV);
        } else if (IS_G4X(dev_priv) || IS_I965GM(dev_priv)) {
                was_enabled = I915_READ(FW_BLC_SELF) & FW_BLC_SELF_EN;
                I915_WRITE(FW_BLC_SELF, enable ? FW_BLC_SELF_EN : 0);
                POSTING_READ(FW_BLC_SELF);
        } else if (IS_PINEVIEW(dev_priv)) {
                val = I915_READ(DSPFW3);
                was_enabled = val & PINEVIEW_SELF_REFRESH_EN;
                if (enable)
                        val |= PINEVIEW_SELF_REFRESH_EN;
                else
                        val &= ~PINEVIEW_SELF_REFRESH_EN;
                I915_WRITE(DSPFW3, val);
                POSTING_READ(DSPFW3);
        } else if (IS_I945G(dev_priv) || IS_I945GM(dev_priv)) {
                was_enabled = I915_READ(FW_BLC_SELF) & FW_BLC_SELF_EN;
                val = enable ? _MASKED_BIT_ENABLE(FW_BLC_SELF_EN) :
                               _MASKED_BIT_DISABLE(FW_BLC_SELF_EN);
                I915_WRITE(FW_BLC_SELF, val);
                POSTING_READ(FW_BLC_SELF);
        } else if (IS_I915GM(dev_priv)) {
                /*
                 * FIXME can't find a bit like this for 915G, and
                 * and yet it does have the related watermark in
                 * FW_BLC_SELF. What's going on?
                 */
                was_enabled = I915_READ(INSTPM) & INSTPM_SELF_EN;
                val = enable ? _MASKED_BIT_ENABLE(INSTPM_SELF_EN) :
                               _MASKED_BIT_DISABLE(INSTPM_SELF_EN);
                I915_WRITE(INSTPM, val);
                POSTING_READ(INSTPM);
        } else {
                return false;
        }

        trace_intel_memory_cxsr(dev_priv, was_enabled, enable);

        DRM_DEBUG_KMS("memory self-refresh is %s (was %s)\n",
                      enableddisabled(enable),
                      enableddisabled(was_enabled));

        return was_enabled;
}

/**
 * intel_set_memory_cxsr - Configure CxSR state
 * @dev_priv: i915 device
 * @enable: Allow vs. disallow CxSR
 *
 * Allow or disallow the system to enter a special CxSR
 * (C-state self refresh) state. What typically happens in CxSR mode
 * is that several display FIFOs may get combined into a single larger
 * FIFO for a particular plane (so called max FIFO mode) to allow the
 * system to defer memory fetches longer, and the memory will enter
 * self refresh.
 *
 * Note that enabling CxSR does not guarantee that the system enter
 * this special mode, nor does it guarantee that the system stays
 * in that mode once entered. So this just allows/disallows the system
 * to autonomously utilize the CxSR mode. Other factors such as core
 * C-states will affect when/if the system actually enters/exits the
 * CxSR mode.
 *
 * Note that on VLV/CHV this actually only controls the max FIFO mode,
 * and the system is free to enter/exit memory self refresh at any time
 * even when the use of CxSR has been disallowed.
 *
 * While the system is actually in the CxSR/max FIFO mode, some plane
 * control registers will not get latched on vblank. Thus in order to
 * guarantee the system will respond to changes in the plane registers
 * we must always disallow CxSR prior to making changes to those registers.
 * Unfortunately the system will re-evaluate the CxSR conditions at
 * frame start which happens after vblank start (which is when the plane
 * registers would get latched), so we can't proceed with the plane update
 * during the same frame where we disallowed CxSR.
 *
 * Certain platforms also have a deeper HPLL SR mode. Fortunately the
 * HPLL SR mode depends on CxSR itself, so we don't have to hand hold
 * the hardware w.r.t. HPLL SR when writing to plane registers.
 * Disallowing just CxSR is sufficient.
 */
bool intel_set_memory_cxsr(struct drm_i915_private *dev_priv, bool enable)
{
        bool ret;

        mutex_lock(&dev_priv->wm.wm_mutex);
        ret = _intel_set_memory_cxsr(dev_priv, enable);
        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                dev_priv->wm.vlv.cxsr = enable;
        else if (IS_G4X(dev_priv))
                dev_priv->wm.g4x.cxsr = enable;
        mutex_unlock(&dev_priv->wm.wm_mutex);

        return ret;
}

/*
 * Latency for FIFO fetches is dependent on several factors:
 *   - memory configuration (speed, channels)
 *   - chipset
 *   - current MCH state
 * It can be fairly high in some situations, so here we assume a fairly
 * pessimal value.  It's a tradeoff between extra memory fetches (if we
 * set this value too high, the FIFO will fetch frequently to stay full)
 * and power consumption (set it too low to save power and we might see
 * FIFO underruns and display "flicker").
 *
 * A value of 5us seems to be a good balance; safe for very low end
 * platforms but not overly aggressive on lower latency configs.
 */
static const int pessimal_latency_ns = 5000;

#define VLV_FIFO_START(dsparb, dsparb2, lo_shift, hi_shift) \
        ((((dsparb) >> (lo_shift)) & 0xff) | ((((dsparb2) >> (hi_shift)) & 0x1) << 8))

static void vlv_get_fifo_size(struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct vlv_fifo_state *fifo_state = &crtc_state->wm.vlv.fifo_state;
        enum pipe pipe = crtc->pipe;
        int sprite0_start, sprite1_start;

        switch (pipe) {
                uint32_t dsparb, dsparb2, dsparb3;
        case PIPE_A:
                dsparb = I915_READ(DSPARB);
                dsparb2 = I915_READ(DSPARB2);
                sprite0_start = VLV_FIFO_START(dsparb, dsparb2, 0, 0);
                sprite1_start = VLV_FIFO_START(dsparb, dsparb2, 8, 4);
                break;
        case PIPE_B:
                dsparb = I915_READ(DSPARB);
                dsparb2 = I915_READ(DSPARB2);
                sprite0_start = VLV_FIFO_START(dsparb, dsparb2, 16, 8);
                sprite1_start = VLV_FIFO_START(dsparb, dsparb2, 24, 12);
                break;
        case PIPE_C:
                dsparb2 = I915_READ(DSPARB2);
                dsparb3 = I915_READ(DSPARB3);
                sprite0_start = VLV_FIFO_START(dsparb3, dsparb2, 0, 16);
                sprite1_start = VLV_FIFO_START(dsparb3, dsparb2, 8, 20);
                break;
        default:
                MISSING_CASE(pipe);
                return;
        }

        fifo_state->plane[PLANE_PRIMARY] = sprite0_start;
        fifo_state->plane[PLANE_SPRITE0] = sprite1_start - sprite0_start;
        fifo_state->plane[PLANE_SPRITE1] = 511 - sprite1_start;
        fifo_state->plane[PLANE_CURSOR] = 63;
}

static int i9xx_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
{
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x7f;
        if (plane)
                size = ((dsparb >> DSPARB_CSTART_SHIFT) & 0x7f) - size;

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A", size);

        return size;
}

static int i830_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
{
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x1ff;
        if (plane)
                size = ((dsparb >> DSPARB_BEND_SHIFT) & 0x1ff) - size;
        size >>= 1; /* Convert to cachelines */

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A", size);

        return size;
}

static int i845_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
{
        uint32_t dsparb = I915_READ(DSPARB);
        int size;

        size = dsparb & 0x7f;
        size >>= 2; /* Convert to cachelines */

        DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
                      plane ? "B" : "A",
                      size);

        return size;
}

/* Pineview has different values for various configs */
static const struct intel_watermark_params pineview_display_wm = {
        .fifo_size = PINEVIEW_DISPLAY_FIFO,
        .max_wm = PINEVIEW_MAX_WM,
        .default_wm = PINEVIEW_DFT_WM,
        .guard_size = PINEVIEW_GUARD_WM,
        .cacheline_size = PINEVIEW_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params pineview_display_hplloff_wm = {
        .fifo_size = PINEVIEW_DISPLAY_FIFO,
        .max_wm = PINEVIEW_MAX_WM,
        .default_wm = PINEVIEW_DFT_HPLLOFF_WM,
        .guard_size = PINEVIEW_GUARD_WM,
        .cacheline_size = PINEVIEW_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params pineview_cursor_wm = {
        .fifo_size = PINEVIEW_CURSOR_FIFO,
        .max_wm = PINEVIEW_CURSOR_MAX_WM,
        .default_wm = PINEVIEW_CURSOR_DFT_WM,
        .guard_size = PINEVIEW_CURSOR_GUARD_WM,
        .cacheline_size = PINEVIEW_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params pineview_cursor_hplloff_wm = {
        .fifo_size = PINEVIEW_CURSOR_FIFO,
        .max_wm = PINEVIEW_CURSOR_MAX_WM,
        .default_wm = PINEVIEW_CURSOR_DFT_WM,
        .guard_size = PINEVIEW_CURSOR_GUARD_WM,
        .cacheline_size = PINEVIEW_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i965_cursor_wm_info = {
        .fifo_size = I965_CURSOR_FIFO,
        .max_wm = I965_CURSOR_MAX_WM,
        .default_wm = I965_CURSOR_DFT_WM,
        .guard_size = 2,
        .cacheline_size = I915_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i945_wm_info = {
        .fifo_size = I945_FIFO_SIZE,
        .max_wm = I915_MAX_WM,
        .default_wm = 1,
        .guard_size = 2,
        .cacheline_size = I915_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i915_wm_info = {
        .fifo_size = I915_FIFO_SIZE,
        .max_wm = I915_MAX_WM,
        .default_wm = 1,
        .guard_size = 2,
        .cacheline_size = I915_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i830_a_wm_info = {
        .fifo_size = I855GM_FIFO_SIZE,
        .max_wm = I915_MAX_WM,
        .default_wm = 1,
        .guard_size = 2,
        .cacheline_size = I830_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i830_bc_wm_info = {
        .fifo_size = I855GM_FIFO_SIZE,
        .max_wm = I915_MAX_WM/2,
        .default_wm = 1,
        .guard_size = 2,
        .cacheline_size = I830_FIFO_LINE_SIZE,
};
static const struct intel_watermark_params i845_wm_info = {
        .fifo_size = I830_FIFO_SIZE,
        .max_wm = I915_MAX_WM,
        .default_wm = 1,
        .guard_size = 2,
        .cacheline_size = I830_FIFO_LINE_SIZE,
};

/**
 * intel_wm_method1 - Method 1 / "small buffer" watermark formula
 * @pixel_rate: Pipe pixel rate in kHz
 * @cpp: Plane bytes per pixel
 * @latency: Memory wakeup latency in 0.1us units
 *
 * Compute the watermark using the method 1 or "small buffer"
 * formula. The caller may additonally add extra cachelines
 * to account for TLB misses and clock crossings.
 *
 * This method is concerned with the short term drain rate
 * of the FIFO, ie. it does not account for blanking periods
 * which would effectively reduce the average drain rate across
 * a longer period. The name "small" refers to the fact the
 * FIFO is relatively small compared to the amount of data
 * fetched.
 *
 * The FIFO level vs. time graph might look something like:
 *
 *   |\   |\
 *   | \  | \
 * __---__---__ (- plane active, _ blanking)
 * -> time
 *
 * or perhaps like this:
 *
 *   |\|\  |\|\
 * __----__----__ (- plane active, _ blanking)
 * -> time
 *
 * Returns:
 * The watermark in bytes
 */
static unsigned int intel_wm_method1(unsigned int pixel_rate,
                                     unsigned int cpp,
                                     unsigned int latency)
{
        uint64_t ret;

        ret = (uint64_t) pixel_rate * cpp * latency;
        ret = DIV_ROUND_UP_ULL(ret, 10000);

        return ret;
}

/**
 * intel_wm_method2 - Method 2 / "large buffer" watermark formula
 * @pixel_rate: Pipe pixel rate in kHz
 * @htotal: Pipe horizontal total
 * @width: Plane width in pixels
 * @cpp: Plane bytes per pixel
 * @latency: Memory wakeup latency in 0.1us units
 *
 * Compute the watermark using the method 2 or "large buffer"
 * formula. The caller may additonally add extra cachelines
 * to account for TLB misses and clock crossings.
 *
 * This method is concerned with the long term drain rate
 * of the FIFO, ie. it does account for blanking periods
 * which effectively reduce the average drain rate across
 * a longer period. The name "large" refers to the fact the
 * FIFO is relatively large compared to the amount of data
 * fetched.
 *
 * The FIFO level vs. time graph might look something like:
 *
 *    |\___       |\___
 *    |    \___   |    \___
 *    |        \  |        \
 * __ --__--__--__--__--__--__ (- plane active, _ blanking)
 * -> time
 *
 * Returns:
 * The watermark in bytes
 */
static unsigned int intel_wm_method2(unsigned int pixel_rate,
                                     unsigned int htotal,
                                     unsigned int width,
                                     unsigned int cpp,
                                     unsigned int latency)
{
        unsigned int ret;

        /*
         * FIXME remove once all users are computing
         * watermarks in the correct place.
         */
        if (WARN_ON_ONCE(htotal == 0))
                htotal = 1;

        ret = (latency * pixel_rate) / (htotal * 10000);
        ret = (ret + 1) * width * cpp;

        return ret;
}

/**
 * intel_calculate_wm - calculate watermark level
 * @pixel_rate: pixel clock
 * @wm: chip FIFO params
 * @cpp: bytes per pixel
 * @latency_ns: memory latency for the platform
 *
 * Calculate the watermark level (the level at which the display plane will
 * start fetching from memory again).  Each chip has a different display
 * FIFO size and allocation, so the caller needs to figure that out and pass
 * in the correct intel_watermark_params structure.
 *
 * As the pixel clock runs, the FIFO will be drained at a rate that depends
 * on the pixel size.  When it reaches the watermark level, it'll start
 * fetching FIFO line sized based chunks from memory until the FIFO fills
 * past the watermark point.  If the FIFO drains completely, a FIFO underrun
 * will occur, and a display engine hang could result.
 */
static unsigned int intel_calculate_wm(int pixel_rate,
                                       const struct intel_watermark_params *wm,
                                       int fifo_size, int cpp,
                                       unsigned int latency_ns)
{
        int entries, wm_size;

        /*
         * Note: we need to make sure we don't overflow for various clock &
         * latency values.
         * clocks go from a few thousand to several hundred thousand.
         * latency is usually a few thousand
         */
        entries = intel_wm_method1(pixel_rate, cpp,
                                   latency_ns / 100);
        entries = DIV_ROUND_UP(entries, wm->cacheline_size) +
                wm->guard_size;
        DRM_DEBUG_KMS("FIFO entries required for mode: %d\n", entries);

        wm_size = fifo_size - entries;
        DRM_DEBUG_KMS("FIFO watermark level: %d\n", wm_size);

        /* Don't promote wm_size to unsigned... */
        if (wm_size > wm->max_wm)
                wm_size = wm->max_wm;
        if (wm_size <= 0)
                wm_size = wm->default_wm;

        /*
         * Bspec seems to indicate that the value shouldn't be lower than
         * 'burst size + 1'. Certainly 830 is quite unhappy with low values.
         * Lets go for 8 which is the burst size since certain platforms
         * already use a hardcoded 8 (which is what the spec says should be
         * done).
         */
        if (wm_size <= 8)
                wm_size = 8;

        return wm_size;
}

static bool is_disabling(int old, int new, int threshold)
{
        return old >= threshold && new < threshold;
}

static bool is_enabling(int old, int new, int threshold)
{
        return old < threshold && new >= threshold;
}

static int intel_wm_num_levels(struct drm_i915_private *dev_priv)
{
        return dev_priv->wm.max_level + 1;
}

static bool intel_wm_plane_visible(const struct intel_crtc_state *crtc_state,
                                   const struct intel_plane_state *plane_state)
{
        struct intel_plane *plane = to_intel_plane(plane_state->base.plane);

        /* FIXME check the 'enable' instead */
        if (!crtc_state->base.active)
                return false;

        /*
         * Treat cursor with fb as always visible since cursor updates
         * can happen faster than the vrefresh rate, and the current
         * watermark code doesn't handle that correctly. Cursor updates
         * which set/clear the fb or change the cursor size are going
         * to get throttled by intel_legacy_cursor_update() to work
         * around this problem with the watermark code.
         */
        if (plane->id == PLANE_CURSOR)
                return plane_state->base.fb != NULL;
        else
                return plane_state->base.visible;
}

static struct intel_crtc *single_enabled_crtc(struct drm_i915_private *dev_priv)
{
        struct intel_crtc *crtc, *enabled = NULL;

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                if (intel_crtc_active(crtc)) {
                        if (enabled)
                                return NULL;
                        enabled = crtc;
                }
        }

        return enabled;
}

static void pineview_update_wm(struct intel_crtc *unused_crtc)
{
        struct drm_i915_private *dev_priv = to_i915(unused_crtc->base.dev);
        struct intel_crtc *crtc;
        const struct cxsr_latency *latency;
        u32 reg;
        unsigned int wm;

        latency = intel_get_cxsr_latency(IS_PINEVIEW_G(dev_priv),
                                         dev_priv->is_ddr3,
                                         dev_priv->fsb_freq,
                                         dev_priv->mem_freq);
        if (!latency) {
                DRM_DEBUG_KMS("Unknown FSB/MEM found, disable CxSR\n");
                intel_set_memory_cxsr(dev_priv, false);
                return;
        }

        crtc = single_enabled_crtc(dev_priv);
        if (crtc) {
                const struct drm_display_mode *adjusted_mode =
                        &crtc->config->base.adjusted_mode;
                const struct drm_framebuffer *fb =
                        crtc->base.primary->state->fb;
                int cpp = fb->format->cpp[0];
                int clock = adjusted_mode->crtc_clock;

                /* Display SR */
                wm = intel_calculate_wm(clock, &pineview_display_wm,
                                        pineview_display_wm.fifo_size,
                                        cpp, latency->display_sr);
                reg = I915_READ(DSPFW1);
                reg &= ~DSPFW_SR_MASK;
                reg |= FW_WM(wm, SR);
                I915_WRITE(DSPFW1, reg);
                DRM_DEBUG_KMS("DSPFW1 register is %x\n", reg);

                /* cursor SR */
                wm = intel_calculate_wm(clock, &pineview_cursor_wm,
                                        pineview_display_wm.fifo_size,
                                        4, latency->cursor_sr);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_CURSOR_SR_MASK;
                reg |= FW_WM(wm, CURSOR_SR);
                I915_WRITE(DSPFW3, reg);

                /* Display HPLL off SR */
                wm = intel_calculate_wm(clock, &pineview_display_hplloff_wm,
                                        pineview_display_hplloff_wm.fifo_size,
                                        cpp, latency->display_hpll_disable);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_HPLL_SR_MASK;
                reg |= FW_WM(wm, HPLL_SR);
                I915_WRITE(DSPFW3, reg);

                /* cursor HPLL off SR */
                wm = intel_calculate_wm(clock, &pineview_cursor_hplloff_wm,
                                        pineview_display_hplloff_wm.fifo_size,
                                        4, latency->cursor_hpll_disable);
                reg = I915_READ(DSPFW3);
                reg &= ~DSPFW_HPLL_CURSOR_MASK;
                reg |= FW_WM(wm, HPLL_CURSOR);
                I915_WRITE(DSPFW3, reg);
                DRM_DEBUG_KMS("DSPFW3 register is %x\n", reg);

                intel_set_memory_cxsr(dev_priv, true);
        } else {
                intel_set_memory_cxsr(dev_priv, false);
        }
}

/*
 * Documentation says:
 * "If the line size is small, the TLB fetches can get in the way of the
 *  data fetches, causing some lag in the pixel data return which is not
 *  accounted for in the above formulas. The following adjustment only
 *  needs to be applied if eight whole lines fit in the buffer at once.
 *  The WM is adjusted upwards by the difference between the FIFO size
 *  and the size of 8 whole lines. This adjustment is always performed
 *  in the actual pixel depth regardless of whether FBC is enabled or not."
 */
static int g4x_tlb_miss_wa(int fifo_size, int width, int cpp)
{
        int tlb_miss = fifo_size * 64 - width * cpp * 8;

        return max(0, tlb_miss);
}

static void g4x_write_wm_values(struct drm_i915_private *dev_priv,
                                const struct g4x_wm_values *wm)
{
        enum pipe pipe;

        for_each_pipe(dev_priv, pipe)
                trace_g4x_wm(intel_get_crtc_for_pipe(dev_priv, pipe), wm);

        I915_WRITE(DSPFW1,
                   FW_WM(wm->sr.plane, SR) |
                   FW_WM(wm->pipe[PIPE_B].plane[PLANE_CURSOR], CURSORB) |
                   FW_WM(wm->pipe[PIPE_B].plane[PLANE_PRIMARY], PLANEB) |
                   FW_WM(wm->pipe[PIPE_A].plane[PLANE_PRIMARY], PLANEA));
        I915_WRITE(DSPFW2,
                   (wm->fbc_en ? DSPFW_FBC_SR_EN : 0) |
                   FW_WM(wm->sr.fbc, FBC_SR) |
                   FW_WM(wm->hpll.fbc, FBC_HPLL_SR) |
                   FW_WM(wm->pipe[PIPE_B].plane[PLANE_SPRITE0], SPRITEB) |
                   FW_WM(wm->pipe[PIPE_A].plane[PLANE_CURSOR], CURSORA) |
                   FW_WM(wm->pipe[PIPE_A].plane[PLANE_SPRITE0], SPRITEA));
        I915_WRITE(DSPFW3,
                   (wm->hpll_en ? DSPFW_HPLL_SR_EN : 0) |
                   FW_WM(wm->sr.cursor, CURSOR_SR) |
                   FW_WM(wm->hpll.cursor, HPLL_CURSOR) |
                   FW_WM(wm->hpll.plane, HPLL_SR));

        POSTING_READ(DSPFW1);
}

#define FW_WM_VLV(value, plane) \
        (((value) << DSPFW_ ## plane ## _SHIFT) & DSPFW_ ## plane ## _MASK_VLV)

static void vlv_write_wm_values(struct drm_i915_private *dev_priv,
                                const struct vlv_wm_values *wm)
{
        enum pipe pipe;

        for_each_pipe(dev_priv, pipe) {
                trace_vlv_wm(intel_get_crtc_for_pipe(dev_priv, pipe), wm);

                I915_WRITE(VLV_DDL(pipe),
                           (wm->ddl[pipe].plane[PLANE_CURSOR] << DDL_CURSOR_SHIFT) |
                           (wm->ddl[pipe].plane[PLANE_SPRITE1] << DDL_SPRITE_SHIFT(1)) |
                           (wm->ddl[pipe].plane[PLANE_SPRITE0] << DDL_SPRITE_SHIFT(0)) |
                           (wm->ddl[pipe].plane[PLANE_PRIMARY] << DDL_PLANE_SHIFT));
        }

        /*
         * Zero the (unused) WM1 watermarks, and also clear all the
         * high order bits so that there are no out of bounds values
         * present in the registers during the reprogramming.
         */
        I915_WRITE(DSPHOWM, 0);
        I915_WRITE(DSPHOWM1, 0);
        I915_WRITE(DSPFW4, 0);
        I915_WRITE(DSPFW5, 0);
        I915_WRITE(DSPFW6, 0);

        I915_WRITE(DSPFW1,
                   FW_WM(wm->sr.plane, SR) |
                   FW_WM(wm->pipe[PIPE_B].plane[PLANE_CURSOR], CURSORB) |
                   FW_WM_VLV(wm->pipe[PIPE_B].plane[PLANE_PRIMARY], PLANEB) |
                   FW_WM_VLV(wm->pipe[PIPE_A].plane[PLANE_PRIMARY], PLANEA));
        I915_WRITE(DSPFW2,
                   FW_WM_VLV(wm->pipe[PIPE_A].plane[PLANE_SPRITE1], SPRITEB) |
                   FW_WM(wm->pipe[PIPE_A].plane[PLANE_CURSOR], CURSORA) |
                   FW_WM_VLV(wm->pipe[PIPE_A].plane[PLANE_SPRITE0], SPRITEA));
        I915_WRITE(DSPFW3,
                   FW_WM(wm->sr.cursor, CURSOR_SR));

        if (IS_CHERRYVIEW(dev_priv)) {
                I915_WRITE(DSPFW7_CHV,
                           FW_WM_VLV(wm->pipe[PIPE_B].plane[PLANE_SPRITE1], SPRITED) |
                           FW_WM_VLV(wm->pipe[PIPE_B].plane[PLANE_SPRITE0], SPRITEC));
                I915_WRITE(DSPFW8_CHV,
                           FW_WM_VLV(wm->pipe[PIPE_C].plane[PLANE_SPRITE1], SPRITEF) |
                           FW_WM_VLV(wm->pipe[PIPE_C].plane[PLANE_SPRITE0], SPRITEE));
                I915_WRITE(DSPFW9_CHV,
                           FW_WM_VLV(wm->pipe[PIPE_C].plane[PLANE_PRIMARY], PLANEC) |
                           FW_WM(wm->pipe[PIPE_C].plane[PLANE_CURSOR], CURSORC));
                I915_WRITE(DSPHOWM,
                           FW_WM(wm->sr.plane >> 9, SR_HI) |
                           FW_WM(wm->pipe[PIPE_C].plane[PLANE_SPRITE1] >> 8, SPRITEF_HI) |
                           FW_WM(wm->pipe[PIPE_C].plane[PLANE_SPRITE0] >> 8, SPRITEE_HI) |
                           FW_WM(wm->pipe[PIPE_C].plane[PLANE_PRIMARY] >> 8, PLANEC_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_SPRITE1] >> 8, SPRITED_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_SPRITE0] >> 8, SPRITEC_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_PRIMARY] >> 8, PLANEB_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_SPRITE1] >> 8, SPRITEB_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_SPRITE0] >> 8, SPRITEA_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_PRIMARY] >> 8, PLANEA_HI));
        } else {
                I915_WRITE(DSPFW7,
                           FW_WM_VLV(wm->pipe[PIPE_B].plane[PLANE_SPRITE1], SPRITED) |
                           FW_WM_VLV(wm->pipe[PIPE_B].plane[PLANE_SPRITE0], SPRITEC));
                I915_WRITE(DSPHOWM,
                           FW_WM(wm->sr.plane >> 9, SR_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_SPRITE1] >> 8, SPRITED_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_SPRITE0] >> 8, SPRITEC_HI) |
                           FW_WM(wm->pipe[PIPE_B].plane[PLANE_PRIMARY] >> 8, PLANEB_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_SPRITE1] >> 8, SPRITEB_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_SPRITE0] >> 8, SPRITEA_HI) |
                           FW_WM(wm->pipe[PIPE_A].plane[PLANE_PRIMARY] >> 8, PLANEA_HI));
        }

        POSTING_READ(DSPFW1);
}

#undef FW_WM_VLV

static void g4x_setup_wm_latency(struct drm_i915_private *dev_priv)
{
        /* all latencies in usec */
        dev_priv->wm.pri_latency[G4X_WM_LEVEL_NORMAL] = 5;
        dev_priv->wm.pri_latency[G4X_WM_LEVEL_SR] = 12;
        dev_priv->wm.pri_latency[G4X_WM_LEVEL_HPLL] = 35;

        dev_priv->wm.max_level = G4X_WM_LEVEL_HPLL;
}

static int g4x_plane_fifo_size(enum plane_id plane_id, int level)
{
        /*
         * DSPCNTR[13] supposedly controls whether the
         * primary plane can use the FIFO space otherwise
         * reserved for the sprite plane. It's not 100% clear
         * what the actual FIFO size is, but it looks like we
         * can happily set both primary and sprite watermarks
         * up to 127 cachelines. So that would seem to mean
         * that either DSPCNTR[13] doesn't do anything, or that
         * the total FIFO is >= 256 cachelines in size. Either
         * way, we don't seem to have to worry about this
         * repartitioning as the maximum watermark value the
         * register can hold for each plane is lower than the
         * minimum FIFO size.
         */
        switch (plane_id) {
        case PLANE_CURSOR:
                return 63;
        case PLANE_PRIMARY:
                return level == G4X_WM_LEVEL_NORMAL ? 127 : 511;
        case PLANE_SPRITE0:
                return level == G4X_WM_LEVEL_NORMAL ? 127 : 0;
        default:
                MISSING_CASE(plane_id);
                return 0;
        }
}

static int g4x_fbc_fifo_size(int level)
{
        switch (level) {
        case G4X_WM_LEVEL_SR:
                return 7;
        case G4X_WM_LEVEL_HPLL:
                return 15;
        default:
                MISSING_CASE(level);
                return 0;
        }
}

static uint16_t g4x_compute_wm(const struct intel_crtc_state *crtc_state,
                               const struct intel_plane_state *plane_state,
                               int level)
{
        struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
        struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
        const struct drm_display_mode *adjusted_mode =
                &crtc_state->base.adjusted_mode;
        int clock, htotal, cpp, width, wm;
        int latency = dev_priv->wm.pri_latency[level] * 10;

        if (latency == 0)
                return USHRT_MAX;

        if (!intel_wm_plane_visible(crtc_state, plane_state))
                return 0;

        /*
         * Not 100% sure which way ELK should go here as the
         * spec only says CL/CTG should assume 32bpp and BW
         * doesn't need to. But as these things followed the
         * mobile vs. desktop lines on gen3 as well, let's
         * assume ELK doesn't need this.
         *
         * The spec also fails to list such a restriction for
         * the HPLL watermark, which seems a little strange.
         * Let's use 32bpp for the HPLL watermark as well.
         */
        if (IS_GM45(dev_priv) && plane->id == PLANE_PRIMARY &&
            level != G4X_WM_LEVEL_NORMAL)
                cpp = 4;
        else
                cpp = plane_state->base.fb->format->cpp[0];

        clock = adjusted_mode->crtc_clock;
        htotal = adjusted_mode->crtc_htotal;

        if (plane->id == PLANE_CURSOR)
                width = plane_state->base.crtc_w;
        else
                width = drm_rect_width(&plane_state->base.dst);

        if (plane->id == PLANE_CURSOR) {
                wm = intel_wm_method2(clock, htotal, width, cpp, latency);
        } else if (plane->id == PLANE_PRIMARY &&
                   level == G4X_WM_LEVEL_NORMAL) {
                wm = intel_wm_method1(clock, cpp, latency);
        } else {
                int small, large;

                small = intel_wm_method1(clock, cpp, latency);
                large = intel_wm_method2(clock, htotal, width, cpp, latency);

                wm = min(small, large);
        }

        wm += g4x_tlb_miss_wa(g4x_plane_fifo_size(plane->id, level),
                              width, cpp);

        wm = DIV_ROUND_UP(wm, 64) + 2;

        return min_t(int, wm, USHRT_MAX);
}

static bool g4x_raw_plane_wm_set(struct intel_crtc_state *crtc_state,
                                 int level, enum plane_id plane_id, u16 value)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        bool dirty = false;

        for (; level < intel_wm_num_levels(dev_priv); level++) {
                struct g4x_pipe_wm *raw = &crtc_state->wm.g4x.raw[level];

                dirty |= raw->plane[plane_id] != value;
                raw->plane[plane_id] = value;
        }

        return dirty;
}

static bool g4x_raw_fbc_wm_set(struct intel_crtc_state *crtc_state,
                               int level, u16 value)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        bool dirty = false;

        /* NORMAL level doesn't have an FBC watermark */
        level = max(level, G4X_WM_LEVEL_SR);

        for (; level < intel_wm_num_levels(dev_priv); level++) {
                struct g4x_pipe_wm *raw = &crtc_state->wm.g4x.raw[level];

                dirty |= raw->fbc != value;
                raw->fbc = value;
        }

        return dirty;
}

static uint32_t ilk_compute_fbc_wm(const struct intel_crtc_state *cstate,
                                   const struct intel_plane_state *pstate,
                                   uint32_t pri_val);

static bool g4x_raw_plane_wm_compute(struct intel_crtc_state *crtc_state,
                                     const struct intel_plane_state *plane_state)
{
        struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
        int num_levels = intel_wm_num_levels(to_i915(plane->base.dev));
        enum plane_id plane_id = plane->id;
        bool dirty = false;
        int level;

        if (!intel_wm_plane_visible(crtc_state, plane_state)) {
                dirty |= g4x_raw_plane_wm_set(crtc_state, 0, plane_id, 0);
                if (plane_id == PLANE_PRIMARY)
                        dirty |= g4x_raw_fbc_wm_set(crtc_state, 0, 0);
                goto out;
        }

        for (level = 0; level < num_levels; level++) {
                struct g4x_pipe_wm *raw = &crtc_state->wm.g4x.raw[level];
                int wm, max_wm;

                wm = g4x_compute_wm(crtc_state, plane_state, level);
                max_wm = g4x_plane_fifo_size(plane_id, level);

                if (wm > max_wm)
                        break;

                dirty |= raw->plane[plane_id] != wm;
                raw->plane[plane_id] = wm;

                if (plane_id != PLANE_PRIMARY ||
                    level == G4X_WM_LEVEL_NORMAL)
                        continue;

                wm = ilk_compute_fbc_wm(crtc_state, plane_state,
                                        raw->plane[plane_id]);
                max_wm = g4x_fbc_fifo_size(level);

                /*
                 * FBC wm is not mandatory as we
                 * can always just disable its use.
                 */
                if (wm > max_wm)
                        wm = USHRT_MAX;

                dirty |= raw->fbc != wm;
                raw->fbc = wm;
        }

        /* mark watermarks as invalid */
        dirty |= g4x_raw_plane_wm_set(crtc_state, level, plane_id, USHRT_MAX);

        if (plane_id == PLANE_PRIMARY)
                dirty |= g4x_raw_fbc_wm_set(crtc_state, level, USHRT_MAX);

 out:
        if (dirty) {
                DRM_DEBUG_KMS("%s watermarks: normal=%d, SR=%d, HPLL=%d\n",
                              plane->base.name,
                              crtc_state->wm.g4x.raw[G4X_WM_LEVEL_NORMAL].plane[plane_id],
                              crtc_state->wm.g4x.raw[G4X_WM_LEVEL_SR].plane[plane_id],
                              crtc_state->wm.g4x.raw[G4X_WM_LEVEL_HPLL].plane[plane_id]);

                if (plane_id == PLANE_PRIMARY)
                        DRM_DEBUG_KMS("FBC watermarks: SR=%d, HPLL=%d\n",
                                      crtc_state->wm.g4x.raw[G4X_WM_LEVEL_SR].fbc,
                                      crtc_state->wm.g4x.raw[G4X_WM_LEVEL_HPLL].fbc);
        }

        return dirty;
}

static bool g4x_raw_plane_wm_is_valid(const struct intel_crtc_state *crtc_state,
                                      enum plane_id plane_id, int level)
{
        const struct g4x_pipe_wm *raw = &crtc_state->wm.g4x.raw[level];

        return raw->plane[plane_id] <= g4x_plane_fifo_size(plane_id, level);
}

static bool g4x_raw_crtc_wm_is_valid(const struct intel_crtc_state *crtc_state,
                                     int level)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);

        if (level > dev_priv->wm.max_level)
                return false;

        return g4x_raw_plane_wm_is_valid(crtc_state, PLANE_PRIMARY, level) &&
                g4x_raw_plane_wm_is_valid(crtc_state, PLANE_SPRITE0, level) &&
                g4x_raw_plane_wm_is_valid(crtc_state, PLANE_CURSOR, level);
}

/* mark all levels starting from 'level' as invalid */
static void g4x_invalidate_wms(struct intel_crtc *crtc,
                               struct g4x_wm_state *wm_state, int level)
{
        if (level <= G4X_WM_LEVEL_NORMAL) {
                enum plane_id plane_id;

                for_each_plane_id_on_crtc(crtc, plane_id)
                        wm_state->wm.plane[plane_id] = USHRT_MAX;
        }

        if (level <= G4X_WM_LEVEL_SR) {
                wm_state->cxsr = false;
                wm_state->sr.cursor = USHRT_MAX;
                wm_state->sr.plane = USHRT_MAX;
                wm_state->sr.fbc = USHRT_MAX;
        }

        if (level <= G4X_WM_LEVEL_HPLL) {
                wm_state->hpll_en = false;
                wm_state->hpll.cursor = USHRT_MAX;
                wm_state->hpll.plane = USHRT_MAX;
                wm_state->hpll.fbc = USHRT_MAX;
        }
}

static int g4x_compute_pipe_wm(struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        struct intel_atomic_state *state =
                to_intel_atomic_state(crtc_state->base.state);
        struct g4x_wm_state *wm_state = &crtc_state->wm.g4x.optimal;
        int num_active_planes = hweight32(crtc_state->active_planes &
                                          ~BIT(PLANE_CURSOR));
        const struct g4x_pipe_wm *raw;
        const struct intel_plane_state *old_plane_state;
        const struct intel_plane_state *new_plane_state;
        struct intel_plane *plane;
        enum plane_id plane_id;
        int i, level;
        unsigned int dirty = 0;

        for_each_oldnew_intel_plane_in_state(state, plane,
                                             old_plane_state,
                                             new_plane_state, i) {
                if (new_plane_state->base.crtc != &crtc->base &&
                    old_plane_state->base.crtc != &crtc->base)
                        continue;

                if (g4x_raw_plane_wm_compute(crtc_state, new_plane_state))
                        dirty |= BIT(plane->id);
        }

        if (!dirty)
                return 0;

        level = G4X_WM_LEVEL_NORMAL;
        if (!g4x_raw_crtc_wm_is_valid(crtc_state, level))
                goto out;

        raw = &crtc_state->wm.g4x.raw[level];
        for_each_plane_id_on_crtc(crtc, plane_id)
                wm_state->wm.plane[plane_id] = raw->plane[plane_id];

        level = G4X_WM_LEVEL_SR;

        if (!g4x_raw_crtc_wm_is_valid(crtc_state, level))
                goto out;

        raw = &crtc_state->wm.g4x.raw[level];
        wm_state->sr.plane = raw->plane[PLANE_PRIMARY];
        wm_state->sr.cursor = raw->plane[PLANE_CURSOR];
        wm_state->sr.fbc = raw->fbc;

        wm_state->cxsr = num_active_planes == BIT(PLANE_PRIMARY);

        level = G4X_WM_LEVEL_HPLL;

        if (!g4x_raw_crtc_wm_is_valid(crtc_state, level))
                goto out;

        raw = &crtc_state->wm.g4x.raw[level];
        wm_state->hpll.plane = raw->plane[PLANE_PRIMARY];
        wm_state->hpll.cursor = raw->plane[PLANE_CURSOR];
        wm_state->hpll.fbc = raw->fbc;

        wm_state->hpll_en = wm_state->cxsr;

        level++;

 out:
        if (level == G4X_WM_LEVEL_NORMAL)
                return -EINVAL;

        /* invalidate the higher levels */
        g4x_invalidate_wms(crtc, wm_state, level);

        /*
         * Determine if the FBC watermark(s) can be used. IF
         * this isn't the case we prefer to disable the FBC
         ( watermark(s) rather than disable the SR/HPLL
         * level(s) entirely.
         */
        wm_state->fbc_en = level > G4X_WM_LEVEL_NORMAL;

        if (level >= G4X_WM_LEVEL_SR &&
            wm_state->sr.fbc > g4x_fbc_fifo_size(G4X_WM_LEVEL_SR))
                wm_state->fbc_en = false;
        else if (level >= G4X_WM_LEVEL_HPLL &&
                 wm_state->hpll.fbc > g4x_fbc_fifo_size(G4X_WM_LEVEL_HPLL))
                wm_state->fbc_en = false;

        return 0;
}

static int g4x_compute_intermediate_wm(struct drm_device *dev,
                                       struct intel_crtc *crtc,
                                       struct intel_crtc_state *crtc_state)
{
        struct g4x_wm_state *intermediate = &crtc_state->wm.g4x.intermediate;
        const struct g4x_wm_state *optimal = &crtc_state->wm.g4x.optimal;
        const struct g4x_wm_state *active = &crtc->wm.active.g4x;
        enum plane_id plane_id;

        intermediate->cxsr = optimal->cxsr && active->cxsr &&
                !crtc_state->disable_cxsr;
        intermediate->hpll_en = optimal->hpll_en && active->hpll_en &&
                !crtc_state->disable_cxsr;
        intermediate->fbc_en = optimal->fbc_en && active->fbc_en;

        for_each_plane_id_on_crtc(crtc, plane_id) {
                intermediate->wm.plane[plane_id] =
                        max(optimal->wm.plane[plane_id],
                            active->wm.plane[plane_id]);

                WARN_ON(intermediate->wm.plane[plane_id] >
                        g4x_plane_fifo_size(plane_id, G4X_WM_LEVEL_NORMAL));
        }

        intermediate->sr.plane = max(optimal->sr.plane,
                                     active->sr.plane);
        intermediate->sr.cursor = max(optimal->sr.cursor,
                                      active->sr.cursor);
        intermediate->sr.fbc = max(optimal->sr.fbc,
                                   active->sr.fbc);

        intermediate->hpll.plane = max(optimal->hpll.plane,
                                       active->hpll.plane);
        intermediate->hpll.cursor = max(optimal->hpll.cursor,
                                        active->hpll.cursor);
        intermediate->hpll.fbc = max(optimal->hpll.fbc,
                                     active->hpll.fbc);

        WARN_ON((intermediate->sr.plane >
                 g4x_plane_fifo_size(PLANE_PRIMARY, G4X_WM_LEVEL_SR) ||
                 intermediate->sr.cursor >
                 g4x_plane_fifo_size(PLANE_CURSOR, G4X_WM_LEVEL_SR)) &&
                intermediate->cxsr);
        WARN_ON((intermediate->sr.plane >
                 g4x_plane_fifo_size(PLANE_PRIMARY, G4X_WM_LEVEL_HPLL) ||
                 intermediate->sr.cursor >
                 g4x_plane_fifo_size(PLANE_CURSOR, G4X_WM_LEVEL_HPLL)) &&
                intermediate->hpll_en);

        WARN_ON(intermediate->sr.fbc > g4x_fbc_fifo_size(1) &&
                intermediate->fbc_en && intermediate->cxsr);
        WARN_ON(intermediate->hpll.fbc > g4x_fbc_fifo_size(2) &&
                intermediate->fbc_en && intermediate->hpll_en);

        /*
         * If our intermediate WM are identical to the final WM, then we can
         * omit the post-vblank programming; only update if it's different.
         */
        if (memcmp(intermediate, optimal, sizeof(*intermediate)) != 0)
                crtc_state->wm.need_postvbl_update = true;

        return 0;
}

static void g4x_merge_wm(struct drm_i915_private *dev_priv,
                         struct g4x_wm_values *wm)
{
        struct intel_crtc *crtc;
        int num_active_crtcs = 0;

        wm->cxsr = true;
        wm->hpll_en = true;
        wm->fbc_en = true;

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                const struct g4x_wm_state *wm_state = &crtc->wm.active.g4x;

                if (!crtc->active)
                        continue;

                if (!wm_state->cxsr)
                        wm->cxsr = false;
                if (!wm_state->hpll_en)
                        wm->hpll_en = false;
                if (!wm_state->fbc_en)
                        wm->fbc_en = false;

                num_active_crtcs++;
        }

        if (num_active_crtcs != 1) {
                wm->cxsr = false;
                wm->hpll_en = false;
                wm->fbc_en = false;
        }

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                const struct g4x_wm_state *wm_state = &crtc->wm.active.g4x;
                enum pipe pipe = crtc->pipe;

                wm->pipe[pipe] = wm_state->wm;
                if (crtc->active && wm->cxsr)
                        wm->sr = wm_state->sr;
                if (crtc->active && wm->hpll_en)
                        wm->hpll = wm_state->hpll;
        }
}

static void g4x_program_watermarks(struct drm_i915_private *dev_priv)
{
        struct g4x_wm_values *old_wm = &dev_priv->wm.g4x;
        struct g4x_wm_values new_wm = {};

        g4x_merge_wm(dev_priv, &new_wm);

        if (memcmp(old_wm, &new_wm, sizeof(new_wm)) == 0)
                return;

        if (is_disabling(old_wm->cxsr, new_wm.cxsr, true))
                _intel_set_memory_cxsr(dev_priv, false);

        g4x_write_wm_values(dev_priv, &new_wm);

        if (is_enabling(old_wm->cxsr, new_wm.cxsr, true))
                _intel_set_memory_cxsr(dev_priv, true);

        *old_wm = new_wm;
}

static void g4x_initial_watermarks(struct intel_atomic_state *state,
                                   struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);

        mutex_lock(&dev_priv->wm.wm_mutex);
        crtc->wm.active.g4x = crtc_state->wm.g4x.intermediate;
        g4x_program_watermarks(dev_priv);
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static void g4x_optimize_watermarks(struct intel_atomic_state *state,
                                    struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc_state->base.crtc);

        if (!crtc_state->wm.need_postvbl_update)
                return;

        mutex_lock(&dev_priv->wm.wm_mutex);
        intel_crtc->wm.active.g4x = crtc_state->wm.g4x.optimal;
        g4x_program_watermarks(dev_priv);
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

/* latency must be in 0.1us units. */
static unsigned int vlv_wm_method2(unsigned int pixel_rate,
                                   unsigned int htotal,
                                   unsigned int width,
                                   unsigned int cpp,
                                   unsigned int latency)
{
        unsigned int ret;

        ret = intel_wm_method2(pixel_rate, htotal,
                               width, cpp, latency);
        ret = DIV_ROUND_UP(ret, 64);

        return ret;
}

static void vlv_setup_wm_latency(struct drm_i915_private *dev_priv)
{
        /* all latencies in usec */
        dev_priv->wm.pri_latency[VLV_WM_LEVEL_PM2] = 3;

        dev_priv->wm.max_level = VLV_WM_LEVEL_PM2;

        if (IS_CHERRYVIEW(dev_priv)) {
                dev_priv->wm.pri_latency[VLV_WM_LEVEL_PM5] = 12;
                dev_priv->wm.pri_latency[VLV_WM_LEVEL_DDR_DVFS] = 33;

                dev_priv->wm.max_level = VLV_WM_LEVEL_DDR_DVFS;
        }
}

static uint16_t vlv_compute_wm_level(const struct intel_crtc_state *crtc_state,
                                     const struct intel_plane_state *plane_state,
                                     int level)
{
        struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
        struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
        const struct drm_display_mode *adjusted_mode =
                &crtc_state->base.adjusted_mode;
        int clock, htotal, cpp, width, wm;

        if (dev_priv->wm.pri_latency[level] == 0)
                return USHRT_MAX;

        if (!intel_wm_plane_visible(crtc_state, plane_state))
                return 0;

        cpp = plane_state->base.fb->format->cpp[0];
        clock = adjusted_mode->crtc_clock;
        htotal = adjusted_mode->crtc_htotal;
        width = crtc_state->pipe_src_w;

        if (plane->id == PLANE_CURSOR) {
                /*
                 * FIXME the formula gives values that are
                 * too big for the cursor FIFO, and hence we
                 * would never be able to use cursors. For
                 * now just hardcode the watermark.
                 */
                wm = 63;
        } else {
                wm = vlv_wm_method2(clock, htotal, width, cpp,
                                    dev_priv->wm.pri_latency[level] * 10);
        }

        return min_t(int, wm, USHRT_MAX);
}

static bool vlv_need_sprite0_fifo_workaround(unsigned int active_planes)
{
        return (active_planes & (BIT(PLANE_SPRITE0) |
                                 BIT(PLANE_SPRITE1))) == BIT(PLANE_SPRITE1);
}

static int vlv_compute_fifo(struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        const struct g4x_pipe_wm *raw =
                &crtc_state->wm.vlv.raw[VLV_WM_LEVEL_PM2];
        struct vlv_fifo_state *fifo_state = &crtc_state->wm.vlv.fifo_state;
        unsigned int active_planes = crtc_state->active_planes & ~BIT(PLANE_CURSOR);
        int num_active_planes = hweight32(active_planes);
        const int fifo_size = 511;
        int fifo_extra, fifo_left = fifo_size;
        int sprite0_fifo_extra = 0;
        unsigned int total_rate;
        enum plane_id plane_id;

        /*
         * When enabling sprite0 after sprite1 has already been enabled
         * we tend to get an underrun unless sprite0 already has some
         * FIFO space allcoated. Hence we always allocate at least one
         * cacheline for sprite0 whenever sprite1 is enabled.
         *
         * All other plane enable sequences appear immune to this problem.
         */
        if (vlv_need_sprite0_fifo_workaround(active_planes))
                sprite0_fifo_extra = 1;

        total_rate = raw->plane[PLANE_PRIMARY] +
                raw->plane[PLANE_SPRITE0] +
                raw->plane[PLANE_SPRITE1] +
                sprite0_fifo_extra;

        if (total_rate > fifo_size)
                return -EINVAL;

        if (total_rate == 0)
                total_rate = 1;

        for_each_plane_id_on_crtc(crtc, plane_id) {
                unsigned int rate;

                if ((active_planes & BIT(plane_id)) == 0) {
                        fifo_state->plane[plane_id] = 0;
                        continue;
                }

                rate = raw->plane[plane_id];
                fifo_state->plane[plane_id] = fifo_size * rate / total_rate;
                fifo_left -= fifo_state->plane[plane_id];
        }

        fifo_state->plane[PLANE_SPRITE0] += sprite0_fifo_extra;
        fifo_left -= sprite0_fifo_extra;

        fifo_state->plane[PLANE_CURSOR] = 63;

        fifo_extra = DIV_ROUND_UP(fifo_left, num_active_planes ?: 1);

        /* spread the remainder evenly */
        for_each_plane_id_on_crtc(crtc, plane_id) {
                int plane_extra;

                if (fifo_left == 0)
                        break;

                if ((active_planes & BIT(plane_id)) == 0)
                        continue;

                plane_extra = min(fifo_extra, fifo_left);
                fifo_state->plane[plane_id] += plane_extra;
                fifo_left -= plane_extra;
        }

        WARN_ON(active_planes != 0 && fifo_left != 0);

        /* give it all to the first plane if none are active */
        if (active_planes == 0) {
                WARN_ON(fifo_left != fifo_size);
                fifo_state->plane[PLANE_PRIMARY] = fifo_left;
        }

        return 0;
}

/* mark all levels starting from 'level' as invalid */
static void vlv_invalidate_wms(struct intel_crtc *crtc,
                               struct vlv_wm_state *wm_state, int level)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

        for (; level < intel_wm_num_levels(dev_priv); level++) {
                enum plane_id plane_id;

                for_each_plane_id_on_crtc(crtc, plane_id)
                        wm_state->wm[level].plane[plane_id] = USHRT_MAX;

                wm_state->sr[level].cursor = USHRT_MAX;
                wm_state->sr[level].plane = USHRT_MAX;
        }
}

static u16 vlv_invert_wm_value(u16 wm, u16 fifo_size)
{
        if (wm > fifo_size)
                return USHRT_MAX;
        else
                return fifo_size - wm;
}

/*
 * Starting from 'level' set all higher
 * levels to 'value' in the "raw" watermarks.
 */
static bool vlv_raw_plane_wm_set(struct intel_crtc_state *crtc_state,
                                 int level, enum plane_id plane_id, u16 value)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        int num_levels = intel_wm_num_levels(dev_priv);
        bool dirty = false;

        for (; level < num_levels; level++) {
                struct g4x_pipe_wm *raw = &crtc_state->wm.vlv.raw[level];

                dirty |= raw->plane[plane_id] != value;
                raw->plane[plane_id] = value;
        }

        return dirty;
}

static bool vlv_raw_plane_wm_compute(struct intel_crtc_state *crtc_state,
                                     const struct intel_plane_state *plane_state)
{
        struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
        enum plane_id plane_id = plane->id;
        int num_levels = intel_wm_num_levels(to_i915(plane->base.dev));
        int level;
        bool dirty = false;

        if (!intel_wm_plane_visible(crtc_state, plane_state)) {
                dirty |= vlv_raw_plane_wm_set(crtc_state, 0, plane_id, 0);
                goto out;
        }

        for (level = 0; level < num_levels; level++) {
                struct g4x_pipe_wm *raw = &crtc_state->wm.vlv.raw[level];
                int wm = vlv_compute_wm_level(crtc_state, plane_state, level);
                int max_wm = plane_id == PLANE_CURSOR ? 63 : 511;

                if (wm > max_wm)
                        break;

                dirty |= raw->plane[plane_id] != wm;
                raw->plane[plane_id] = wm;
        }

        /* mark all higher levels as invalid */
        dirty |= vlv_raw_plane_wm_set(crtc_state, level, plane_id, USHRT_MAX);

out:
        if (dirty)
                DRM_DEBUG_KMS("%s watermarks: PM2=%d, PM5=%d, DDR DVFS=%d\n",
                              plane->base.name,
                              crtc_state->wm.vlv.raw[VLV_WM_LEVEL_PM2].plane[plane_id],
                              crtc_state->wm.vlv.raw[VLV_WM_LEVEL_PM5].plane[plane_id],
                              crtc_state->wm.vlv.raw[VLV_WM_LEVEL_DDR_DVFS].plane[plane_id]);

        return dirty;
}

static bool vlv_raw_plane_wm_is_valid(const struct intel_crtc_state *crtc_state,
                                      enum plane_id plane_id, int level)
{
        const struct g4x_pipe_wm *raw =
                &crtc_state->wm.vlv.raw[level];
        const struct vlv_fifo_state *fifo_state =
                &crtc_state->wm.vlv.fifo_state;

        return raw->plane[plane_id] <= fifo_state->plane[plane_id];
}

static bool vlv_raw_crtc_wm_is_valid(const struct intel_crtc_state *crtc_state, int level)
{
        return vlv_raw_plane_wm_is_valid(crtc_state, PLANE_PRIMARY, level) &&
                vlv_raw_plane_wm_is_valid(crtc_state, PLANE_SPRITE0, level) &&
                vlv_raw_plane_wm_is_valid(crtc_state, PLANE_SPRITE1, level) &&
                vlv_raw_plane_wm_is_valid(crtc_state, PLANE_CURSOR, level);
}

static int vlv_compute_pipe_wm(struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_atomic_state *state =
                to_intel_atomic_state(crtc_state->base.state);
        struct vlv_wm_state *wm_state = &crtc_state->wm.vlv.optimal;
        const struct vlv_fifo_state *fifo_state =
                &crtc_state->wm.vlv.fifo_state;
        int num_active_planes = hweight32(crtc_state->active_planes &
                                          ~BIT(PLANE_CURSOR));
        bool needs_modeset = drm_atomic_crtc_needs_modeset(&crtc_state->base);
        const struct intel_plane_state *old_plane_state;
        const struct intel_plane_state *new_plane_state;
        struct intel_plane *plane;
        enum plane_id plane_id;
        int level, ret, i;
        unsigned int dirty = 0;

        for_each_oldnew_intel_plane_in_state(state, plane,
                                             old_plane_state,
                                             new_plane_state, i) {
                if (new_plane_state->base.crtc != &crtc->base &&
                    old_plane_state->base.crtc != &crtc->base)
                        continue;

                if (vlv_raw_plane_wm_compute(crtc_state, new_plane_state))
                        dirty |= BIT(plane->id);
        }

        /*
         * DSPARB registers may have been reset due to the
         * power well being turned off. Make sure we restore
         * them to a consistent state even if no primary/sprite
         * planes are initially active.
         */
        if (needs_modeset)
                crtc_state->fifo_changed = true;

        if (!dirty)
                return 0;

        /* cursor changes don't warrant a FIFO recompute */
        if (dirty & ~BIT(PLANE_CURSOR)) {
                const struct intel_crtc_state *old_crtc_state =
                        intel_atomic_get_old_crtc_state(state, crtc);
                const struct vlv_fifo_state *old_fifo_state =
                        &old_crtc_state->wm.vlv.fifo_state;

                ret = vlv_compute_fifo(crtc_state);
                if (ret)
                        return ret;

                if (needs_modeset ||
                    memcmp(old_fifo_state, fifo_state,
                           sizeof(*fifo_state)) != 0)
                        crtc_state->fifo_changed = true;
        }

        /* initially allow all levels */
        wm_state->num_levels = intel_wm_num_levels(dev_priv);
        /*
         * Note that enabling cxsr with no primary/sprite planes
         * enabled can wedge the pipe. Hence we only allow cxsr
         * with exactly one enabled primary/sprite plane.
         */
        wm_state->cxsr = crtc->pipe != PIPE_C && num_active_planes == 1;

        for (level = 0; level < wm_state->num_levels; level++) {
                const struct g4x_pipe_wm *raw = &crtc_state->wm.vlv.raw[level];
                const int sr_fifo_size = INTEL_INFO(dev_priv)->num_pipes * 512 - 1;

                if (!vlv_raw_crtc_wm_is_valid(crtc_state, level))
                        break;

                for_each_plane_id_on_crtc(crtc, plane_id) {
                        wm_state->wm[level].plane[plane_id] =
                                vlv_invert_wm_value(raw->plane[plane_id],
                                                    fifo_state->plane[plane_id]);
                }

                wm_state->sr[level].plane =
                        vlv_invert_wm_value(max3(raw->plane[PLANE_PRIMARY],
                                                 raw->plane[PLANE_SPRITE0],
                                                 raw->plane[PLANE_SPRITE1]),
                                            sr_fifo_size);

                wm_state->sr[level].cursor =
                        vlv_invert_wm_value(raw->plane[PLANE_CURSOR],
                                            63);
        }

        if (level == 0)
                return -EINVAL;

        /* limit to only levels we can actually handle */
        wm_state->num_levels = level;

        /* invalidate the higher levels */
        vlv_invalidate_wms(crtc, wm_state, level);

        return 0;
}

#define VLV_FIFO(plane, value) \
        (((value) << DSPARB_ ## plane ## _SHIFT_VLV) & DSPARB_ ## plane ## _MASK_VLV)

static void vlv_atomic_update_fifo(struct intel_atomic_state *state,
                                   struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        const struct vlv_fifo_state *fifo_state =
                &crtc_state->wm.vlv.fifo_state;
        int sprite0_start, sprite1_start, fifo_size;

        if (!crtc_state->fifo_changed)
                return;

        sprite0_start = fifo_state->plane[PLANE_PRIMARY];
        sprite1_start = fifo_state->plane[PLANE_SPRITE0] + sprite0_start;
        fifo_size = fifo_state->plane[PLANE_SPRITE1] + sprite1_start;

        WARN_ON(fifo_state->plane[PLANE_CURSOR] != 63);
        WARN_ON(fifo_size != 511);

        trace_vlv_fifo_size(crtc, sprite0_start, sprite1_start, fifo_size);

        /*
         * uncore.lock serves a double purpose here. It allows us to
         * use the less expensive I915_{READ,WRITE}_FW() functions, and
         * it protects the DSPARB registers from getting clobbered by
         * parallel updates from multiple pipes.
         *
         * intel_pipe_update_start() has already disabled interrupts
         * for us, so a plain spin_lock() is sufficient here.
         */
        spin_lock(&dev_priv->uncore.lock);

        switch (crtc->pipe) {
                uint32_t dsparb, dsparb2, dsparb3;
        case PIPE_A:
                dsparb = I915_READ_FW(DSPARB);
                dsparb2 = I915_READ_FW(DSPARB2);

                dsparb &= ~(VLV_FIFO(SPRITEA, 0xff) |
                            VLV_FIFO(SPRITEB, 0xff));
                dsparb |= (VLV_FIFO(SPRITEA, sprite0_start) |
                           VLV_FIFO(SPRITEB, sprite1_start));

                dsparb2 &= ~(VLV_FIFO(SPRITEA_HI, 0x1) |
                             VLV_FIFO(SPRITEB_HI, 0x1));
                dsparb2 |= (VLV_FIFO(SPRITEA_HI, sprite0_start >> 8) |
                           VLV_FIFO(SPRITEB_HI, sprite1_start >> 8));

                I915_WRITE_FW(DSPARB, dsparb);
                I915_WRITE_FW(DSPARB2, dsparb2);
                break;
        case PIPE_B:
                dsparb = I915_READ_FW(DSPARB);
                dsparb2 = I915_READ_FW(DSPARB2);

                dsparb &= ~(VLV_FIFO(SPRITEC, 0xff) |
                            VLV_FIFO(SPRITED, 0xff));
                dsparb |= (VLV_FIFO(SPRITEC, sprite0_start) |
                           VLV_FIFO(SPRITED, sprite1_start));

                dsparb2 &= ~(VLV_FIFO(SPRITEC_HI, 0xff) |
                             VLV_FIFO(SPRITED_HI, 0xff));
                dsparb2 |= (VLV_FIFO(SPRITEC_HI, sprite0_start >> 8) |
                           VLV_FIFO(SPRITED_HI, sprite1_start >> 8));

                I915_WRITE_FW(DSPARB, dsparb);
                I915_WRITE_FW(DSPARB2, dsparb2);
                break;
        case PIPE_C:
                dsparb3 = I915_READ_FW(DSPARB3);
                dsparb2 = I915_READ_FW(DSPARB2);

                dsparb3 &= ~(VLV_FIFO(SPRITEE, 0xff) |
                             VLV_FIFO(SPRITEF, 0xff));
                dsparb3 |= (VLV_FIFO(SPRITEE, sprite0_start) |
                            VLV_FIFO(SPRITEF, sprite1_start));

                dsparb2 &= ~(VLV_FIFO(SPRITEE_HI, 0xff) |
                             VLV_FIFO(SPRITEF_HI, 0xff));
                dsparb2 |= (VLV_FIFO(SPRITEE_HI, sprite0_start >> 8) |
                           VLV_FIFO(SPRITEF_HI, sprite1_start >> 8));

                I915_WRITE_FW(DSPARB3, dsparb3);
                I915_WRITE_FW(DSPARB2, dsparb2);
                break;
        default:
                break;
        }

        POSTING_READ_FW(DSPARB);

        spin_unlock(&dev_priv->uncore.lock);
}

#undef VLV_FIFO

static int vlv_compute_intermediate_wm(struct drm_device *dev,
                                       struct intel_crtc *crtc,
                                       struct intel_crtc_state *crtc_state)
{
        struct vlv_wm_state *intermediate = &crtc_state->wm.vlv.intermediate;
        const struct vlv_wm_state *optimal = &crtc_state->wm.vlv.optimal;
        const struct vlv_wm_state *active = &crtc->wm.active.vlv;
        int level;

        intermediate->num_levels = min(optimal->num_levels, active->num_levels);
        intermediate->cxsr = optimal->cxsr && active->cxsr &&
                !crtc_state->disable_cxsr;

        for (level = 0; level < intermediate->num_levels; level++) {
                enum plane_id plane_id;

                for_each_plane_id_on_crtc(crtc, plane_id) {
                        intermediate->wm[level].plane[plane_id] =
                                min(optimal->wm[level].plane[plane_id],
                                    active->wm[level].plane[plane_id]);
                }

                intermediate->sr[level].plane = min(optimal->sr[level].plane,
                                                    active->sr[level].plane);
                intermediate->sr[level].cursor = min(optimal->sr[level].cursor,
                                                     active->sr[level].cursor);
        }

        vlv_invalidate_wms(crtc, intermediate, level);

        /*
         * If our intermediate WM are identical to the final WM, then we can
         * omit the post-vblank programming; only update if it's different.
         */
        if (memcmp(intermediate, optimal, sizeof(*intermediate)) != 0)
                crtc_state->wm.need_postvbl_update = true;

        return 0;
}

static void vlv_merge_wm(struct drm_i915_private *dev_priv,
                         struct vlv_wm_values *wm)
{
        struct intel_crtc *crtc;
        int num_active_crtcs = 0;

        wm->level = dev_priv->wm.max_level;
        wm->cxsr = true;

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                const struct vlv_wm_state *wm_state = &crtc->wm.active.vlv;

                if (!crtc->active)
                        continue;

                if (!wm_state->cxsr)
                        wm->cxsr = false;

                num_active_crtcs++;
                wm->level = min_t(int, wm->level, wm_state->num_levels - 1);
        }

        if (num_active_crtcs != 1)
                wm->cxsr = false;

        if (num_active_crtcs > 1)
                wm->level = VLV_WM_LEVEL_PM2;

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                const struct vlv_wm_state *wm_state = &crtc->wm.active.vlv;
                enum pipe pipe = crtc->pipe;

                wm->pipe[pipe] = wm_state->wm[wm->level];
                if (crtc->active && wm->cxsr)
                        wm->sr = wm_state->sr[wm->level];

                wm->ddl[pipe].plane[PLANE_PRIMARY] = DDL_PRECISION_HIGH | 2;
                wm->ddl[pipe].plane[PLANE_SPRITE0] = DDL_PRECISION_HIGH | 2;
                wm->ddl[pipe].plane[PLANE_SPRITE1] = DDL_PRECISION_HIGH | 2;
                wm->ddl[pipe].plane[PLANE_CURSOR] = DDL_PRECISION_HIGH | 2;
        }
}

static void vlv_program_watermarks(struct drm_i915_private *dev_priv)
{
        struct vlv_wm_values *old_wm = &dev_priv->wm.vlv;
        struct vlv_wm_values new_wm = {};

        vlv_merge_wm(dev_priv, &new_wm);

        if (memcmp(old_wm, &new_wm, sizeof(new_wm)) == 0)
                return;

        if (is_disabling(old_wm->level, new_wm.level, VLV_WM_LEVEL_DDR_DVFS))
                chv_set_memory_dvfs(dev_priv, false);

        if (is_disabling(old_wm->level, new_wm.level, VLV_WM_LEVEL_PM5))
                chv_set_memory_pm5(dev_priv, false);

        if (is_disabling(old_wm->cxsr, new_wm.cxsr, true))
                _intel_set_memory_cxsr(dev_priv, false);

        vlv_write_wm_values(dev_priv, &new_wm);

        if (is_enabling(old_wm->cxsr, new_wm.cxsr, true))
                _intel_set_memory_cxsr(dev_priv, true);

        if (is_enabling(old_wm->level, new_wm.level, VLV_WM_LEVEL_PM5))
                chv_set_memory_pm5(dev_priv, true);

        if (is_enabling(old_wm->level, new_wm.level, VLV_WM_LEVEL_DDR_DVFS))
                chv_set_memory_dvfs(dev_priv, true);

        *old_wm = new_wm;
}

static void vlv_initial_watermarks(struct intel_atomic_state *state,
                                   struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);

        mutex_lock(&dev_priv->wm.wm_mutex);
        crtc->wm.active.vlv = crtc_state->wm.vlv.intermediate;
        vlv_program_watermarks(dev_priv);
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static void vlv_optimize_watermarks(struct intel_atomic_state *state,
                                    struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc_state->base.crtc);

        if (!crtc_state->wm.need_postvbl_update)
                return;

        mutex_lock(&dev_priv->wm.wm_mutex);
        intel_crtc->wm.active.vlv = crtc_state->wm.vlv.optimal;
        vlv_program_watermarks(dev_priv);
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static void i965_update_wm(struct intel_crtc *unused_crtc)
{
        struct drm_i915_private *dev_priv = to_i915(unused_crtc->base.dev);
        struct intel_crtc *crtc;
        int srwm = 1;
        int cursor_sr = 16;
        bool cxsr_enabled;

        /* Calc sr entries for one plane configs */
        crtc = single_enabled_crtc(dev_priv);
        if (crtc) {
                /* self-refresh has much higher latency */
                static const int sr_latency_ns = 12000;
                const struct drm_display_mode *adjusted_mode =
                        &crtc->config->base.adjusted_mode;
                const struct drm_framebuffer *fb =
                        crtc->base.primary->state->fb;
                int clock = adjusted_mode->crtc_clock;
                int htotal = adjusted_mode->crtc_htotal;
                int hdisplay = crtc->config->pipe_src_w;
                int cpp = fb->format->cpp[0];
                int entries;

                entries = intel_wm_method2(clock, htotal,
                                           hdisplay, cpp, sr_latency_ns / 100);
                entries = DIV_ROUND_UP(entries, I915_FIFO_LINE_SIZE);
                srwm = I965_FIFO_SIZE - entries;
                if (srwm < 0)
                        srwm = 1;
                srwm &= 0x1ff;
                DRM_DEBUG_KMS("self-refresh entries: %d, wm: %d\n",
                              entries, srwm);

                entries = intel_wm_method2(clock, htotal,
                                           crtc->base.cursor->state->crtc_w, 4,
                                           sr_latency_ns / 100);
                entries = DIV_ROUND_UP(entries,
                                       i965_cursor_wm_info.cacheline_size) +
                        i965_cursor_wm_info.guard_size;

                cursor_sr = i965_cursor_wm_info.fifo_size - entries;
                if (cursor_sr > i965_cursor_wm_info.max_wm)
                        cursor_sr = i965_cursor_wm_info.max_wm;

                DRM_DEBUG_KMS("self-refresh watermark: display plane %d "
                              "cursor %d\n", srwm, cursor_sr);

                cxsr_enabled = true;
        } else {
                cxsr_enabled = false;
                /* Turn off self refresh if both pipes are enabled */
                intel_set_memory_cxsr(dev_priv, false);
        }

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: 8, B: 8, C: 8, SR %d\n",
                      srwm);

        /* 965 has limitations... */
        I915_WRITE(DSPFW1, FW_WM(srwm, SR) |
                   FW_WM(8, CURSORB) |
                   FW_WM(8, PLANEB) |
                   FW_WM(8, PLANEA));
        I915_WRITE(DSPFW2, FW_WM(8, CURSORA) |
                   FW_WM(8, PLANEC_OLD));
        /* update cursor SR watermark */
        I915_WRITE(DSPFW3, FW_WM(cursor_sr, CURSOR_SR));

        if (cxsr_enabled)
                intel_set_memory_cxsr(dev_priv, true);
}

#undef FW_WM

static void i9xx_update_wm(struct intel_crtc *unused_crtc)
{
        struct drm_i915_private *dev_priv = to_i915(unused_crtc->base.dev);
        const struct intel_watermark_params *wm_info;
        uint32_t fwater_lo;
        uint32_t fwater_hi;
        int cwm, srwm = 1;
        int fifo_size;
        int planea_wm, planeb_wm;
        struct intel_crtc *crtc, *enabled = NULL;

        if (IS_I945GM(dev_priv))
                wm_info = &i945_wm_info;
        else if (!IS_GEN2(dev_priv))
                wm_info = &i915_wm_info;
        else
                wm_info = &i830_a_wm_info;

        fifo_size = dev_priv->display.get_fifo_size(dev_priv, 0);
        crtc = intel_get_crtc_for_plane(dev_priv, 0);
        if (intel_crtc_active(crtc)) {
                const struct drm_display_mode *adjusted_mode =
                        &crtc->config->base.adjusted_mode;
                const struct drm_framebuffer *fb =
                        crtc->base.primary->state->fb;
                int cpp;

                if (IS_GEN2(dev_priv))
                        cpp = 4;
                else
                        cpp = fb->format->cpp[0];

                planea_wm = intel_calculate_wm(adjusted_mode->crtc_clock,
                                               wm_info, fifo_size, cpp,
                                               pessimal_latency_ns);
                enabled = crtc;
        } else {
                planea_wm = fifo_size - wm_info->guard_size;
                if (planea_wm > (long)wm_info->max_wm)
                        planea_wm = wm_info->max_wm;
        }

        if (IS_GEN2(dev_priv))
                wm_info = &i830_bc_wm_info;

        fifo_size = dev_priv->display.get_fifo_size(dev_priv, 1);
        crtc = intel_get_crtc_for_plane(dev_priv, 1);
        if (intel_crtc_active(crtc)) {
                const struct drm_display_mode *adjusted_mode =
                        &crtc->config->base.adjusted_mode;
                const struct drm_framebuffer *fb =
                        crtc->base.primary->state->fb;
                int cpp;

                if (IS_GEN2(dev_priv))
                        cpp = 4;
                else
                        cpp = fb->format->cpp[0];

                planeb_wm = intel_calculate_wm(adjusted_mode->crtc_clock,
                                               wm_info, fifo_size, cpp,
                                               pessimal_latency_ns);
                if (enabled == NULL)
                        enabled = crtc;
                else
                        enabled = NULL;
        } else {
                planeb_wm = fifo_size - wm_info->guard_size;
                if (planeb_wm > (long)wm_info->max_wm)
                        planeb_wm = wm_info->max_wm;
        }

        DRM_DEBUG_KMS("FIFO watermarks - A: %d, B: %d\n", planea_wm, planeb_wm);

        if (IS_I915GM(dev_priv) && enabled) {
                struct drm_i915_gem_object *obj;

                obj = intel_fb_obj(enabled->base.primary->state->fb);

                /* self-refresh seems busted with untiled */
                if (!i915_gem_object_is_tiled(obj))
                        enabled = NULL;
        }

        /*
         * Overlay gets an aggressive default since video jitter is bad.
         */
        cwm = 2;

        /* Play safe and disable self-refresh before adjusting watermarks. */
        intel_set_memory_cxsr(dev_priv, false);

        /* Calc sr entries for one plane configs */
        if (HAS_FW_BLC(dev_priv) && enabled) {
                /* self-refresh has much higher latency */
                static const int sr_latency_ns = 6000;
                const struct drm_display_mode *adjusted_mode =
                        &enabled->config->base.adjusted_mode;
                const struct drm_framebuffer *fb =
                        enabled->base.primary->state->fb;
                int clock = adjusted_mode->crtc_clock;
                int htotal = adjusted_mode->crtc_htotal;
                int hdisplay = enabled->config->pipe_src_w;
                int cpp;
                int entries;

                if (IS_I915GM(dev_priv) || IS_I945GM(dev_priv))
                        cpp = 4;
                else
                        cpp = fb->format->cpp[0];

                entries = intel_wm_method2(clock, htotal, hdisplay, cpp,
                                           sr_latency_ns / 100);
                entries = DIV_ROUND_UP(entries, wm_info->cacheline_size);
                DRM_DEBUG_KMS("self-refresh entries: %d\n", entries);
                srwm = wm_info->fifo_size - entries;
                if (srwm < 0)
                        srwm = 1;

                if (IS_I945G(dev_priv) || IS_I945GM(dev_priv))
                        I915_WRITE(FW_BLC_SELF,
                                   FW_BLC_SELF_FIFO_MASK | (srwm & 0xff));
                else
                        I915_WRITE(FW_BLC_SELF, srwm & 0x3f);
        }

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n",
                      planea_wm, planeb_wm, cwm, srwm);

        fwater_lo = ((planeb_wm & 0x3f) << 16) | (planea_wm & 0x3f);
        fwater_hi = (cwm & 0x1f);

        /* Set request length to 8 cachelines per fetch */
        fwater_lo = fwater_lo | (1 << 24) | (1 << 8);
        fwater_hi = fwater_hi | (1 << 8);

        I915_WRITE(FW_BLC, fwater_lo);
        I915_WRITE(FW_BLC2, fwater_hi);

        if (enabled)
                intel_set_memory_cxsr(dev_priv, true);
}

static void i845_update_wm(struct intel_crtc *unused_crtc)
{
        struct drm_i915_private *dev_priv = to_i915(unused_crtc->base.dev);
        struct intel_crtc *crtc;
        const struct drm_display_mode *adjusted_mode;
        uint32_t fwater_lo;
        int planea_wm;

        crtc = single_enabled_crtc(dev_priv);
        if (crtc == NULL)
                return;

        adjusted_mode = &crtc->config->base.adjusted_mode;
        planea_wm = intel_calculate_wm(adjusted_mode->crtc_clock,
                                       &i845_wm_info,
                                       dev_priv->display.get_fifo_size(dev_priv, 0),
                                       4, pessimal_latency_ns);
        fwater_lo = I915_READ(FW_BLC) & ~0xfff;
        fwater_lo |= (3<<8) | planea_wm;

        DRM_DEBUG_KMS("Setting FIFO watermarks - A: %d\n", planea_wm);

        I915_WRITE(FW_BLC, fwater_lo);
}

/* latency must be in 0.1us units. */
static unsigned int ilk_wm_method1(unsigned int pixel_rate,
                                   unsigned int cpp,
                                   unsigned int latency)
{
        unsigned int ret;

        ret = intel_wm_method1(pixel_rate, cpp, latency);
        ret = DIV_ROUND_UP(ret, 64) + 2;

        return ret;
}

/* latency must be in 0.1us units. */
static unsigned int ilk_wm_method2(unsigned int pixel_rate,
                                   unsigned int htotal,
                                   unsigned int width,
                                   unsigned int cpp,
                                   unsigned int latency)
{
        unsigned int ret;

        ret = intel_wm_method2(pixel_rate, htotal,
                               width, cpp, latency);
        ret = DIV_ROUND_UP(ret, 64) + 2;

        return ret;
}

static uint32_t ilk_wm_fbc(uint32_t pri_val, uint32_t horiz_pixels,
                           uint8_t cpp)
{
        /*
         * Neither of these should be possible since this function shouldn't be
         * called if the CRTC is off or the plane is invisible.  But let's be
         * extra paranoid to avoid a potential divide-by-zero if we screw up
         * elsewhere in the driver.
         */
        if (WARN_ON(!cpp))
                return 0;
        if (WARN_ON(!horiz_pixels))
                return 0;

        return DIV_ROUND_UP(pri_val * 64, horiz_pixels * cpp) + 2;
}

struct ilk_wm_maximums {
        uint16_t pri;
        uint16_t spr;
        uint16_t cur;
        uint16_t fbc;
};

/*
 * For both WM_PIPE and WM_LP.
 * mem_value must be in 0.1us units.
 */
static uint32_t ilk_compute_pri_wm(const struct intel_crtc_state *cstate,
                                   const struct intel_plane_state *pstate,
                                   uint32_t mem_value,
                                   bool is_lp)
{
        uint32_t method1, method2;
        int cpp;

        if (!intel_wm_plane_visible(cstate, pstate))
                return 0;

        cpp = pstate->base.fb->format->cpp[0];

        method1 = ilk_wm_method1(cstate->pixel_rate, cpp, mem_value);

        if (!is_lp)
                return method1;

        method2 = ilk_wm_method2(cstate->pixel_rate,
                                 cstate->base.adjusted_mode.crtc_htotal,
                                 drm_rect_width(&pstate->base.dst),
                                 cpp, mem_value);

        return min(method1, method2);
}

/*
 * For both WM_PIPE and WM_LP.
 * mem_value must be in 0.1us units.
 */
static uint32_t ilk_compute_spr_wm(const struct intel_crtc_state *cstate,
                                   const struct intel_plane_state *pstate,
                                   uint32_t mem_value)
{
        uint32_t method1, method2;
        int cpp;

        if (!intel_wm_plane_visible(cstate, pstate))
                return 0;

        cpp = pstate->base.fb->format->cpp[0];

        method1 = ilk_wm_method1(cstate->pixel_rate, cpp, mem_value);
        method2 = ilk_wm_method2(cstate->pixel_rate,
                                 cstate->base.adjusted_mode.crtc_htotal,
                                 drm_rect_width(&pstate->base.dst),
                                 cpp, mem_value);
        return min(method1, method2);
}

/*
 * For both WM_PIPE and WM_LP.
 * mem_value must be in 0.1us units.
 */
static uint32_t ilk_compute_cur_wm(const struct intel_crtc_state *cstate,
                                   const struct intel_plane_state *pstate,
                                   uint32_t mem_value)
{
        int cpp;

        if (!intel_wm_plane_visible(cstate, pstate))
                return 0;

        cpp = pstate->base.fb->format->cpp[0];

        return ilk_wm_method2(cstate->pixel_rate,
                              cstate->base.adjusted_mode.crtc_htotal,
                              pstate->base.crtc_w, cpp, mem_value);
}

/* Only for WM_LP. */
static uint32_t ilk_compute_fbc_wm(const struct intel_crtc_state *cstate,
                                   const struct intel_plane_state *pstate,
                                   uint32_t pri_val)
{
        int cpp;

        if (!intel_wm_plane_visible(cstate, pstate))
                return 0;

        cpp = pstate->base.fb->format->cpp[0];

        return ilk_wm_fbc(pri_val, drm_rect_width(&pstate->base.dst), cpp);
}

static unsigned int
ilk_display_fifo_size(const struct drm_i915_private *dev_priv)
{
        if (INTEL_GEN(dev_priv) >= 8)
                return 3072;
        else if (INTEL_GEN(dev_priv) >= 7)
                return 768;
        else
                return 512;
}

static unsigned int
ilk_plane_wm_reg_max(const struct drm_i915_private *dev_priv,
                     int level, bool is_sprite)
{
        if (INTEL_GEN(dev_priv) >= 8)
                /* BDW primary/sprite plane watermarks */
                return level == 0 ? 255 : 2047;
        else if (INTEL_GEN(dev_priv) >= 7)
                /* IVB/HSW primary/sprite plane watermarks */
                return level == 0 ? 127 : 1023;
        else if (!is_sprite)
                /* ILK/SNB primary plane watermarks */
                return level == 0 ? 127 : 511;
        else
                /* ILK/SNB sprite plane watermarks */
                return level == 0 ? 63 : 255;
}

static unsigned int
ilk_cursor_wm_reg_max(const struct drm_i915_private *dev_priv, int level)
{
        if (INTEL_GEN(dev_priv) >= 7)
                return level == 0 ? 63 : 255;
        else
                return level == 0 ? 31 : 63;
}

static unsigned int ilk_fbc_wm_reg_max(const struct drm_i915_private *dev_priv)
{
        if (INTEL_GEN(dev_priv) >= 8)
                return 31;
        else
                return 15;
}

/* Calculate the maximum primary/sprite plane watermark */
static unsigned int ilk_plane_wm_max(const struct drm_device *dev,
                                     int level,
                                     const struct intel_wm_config *config,
                                     enum intel_ddb_partitioning ddb_partitioning,
                                     bool is_sprite)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        unsigned int fifo_size = ilk_display_fifo_size(dev_priv);

        /* if sprites aren't enabled, sprites get nothing */
        if (is_sprite && !config->sprites_enabled)
                return 0;

        /* HSW allows LP1+ watermarks even with multiple pipes */
        if (level == 0 || config->num_pipes_active > 1) {
                fifo_size /= INTEL_INFO(dev_priv)->num_pipes;

                /*
                 * For some reason the non self refresh
                 * FIFO size is only half of the self
                 * refresh FIFO size on ILK/SNB.
                 */
                if (INTEL_GEN(dev_priv) <= 6)
                        fifo_size /= 2;
        }

        if (config->sprites_enabled) {
                /* level 0 is always calculated with 1:1 split */
                if (level > 0 && ddb_partitioning == INTEL_DDB_PART_5_6) {
                        if (is_sprite)
                                fifo_size *= 5;
                        fifo_size /= 6;
                } else {
                        fifo_size /= 2;
                }
        }

        /* clamp to max that the registers can hold */
        return min(fifo_size, ilk_plane_wm_reg_max(dev_priv, level, is_sprite));
}

/* Calculate the maximum cursor plane watermark */
static unsigned int ilk_cursor_wm_max(const struct drm_device *dev,
                                      int level,
                                      const struct intel_wm_config *config)
{
        /* HSW LP1+ watermarks w/ multiple pipes */
        if (level > 0 && config->num_pipes_active > 1)
                return 64;

        /* otherwise just report max that registers can hold */
        return ilk_cursor_wm_reg_max(to_i915(dev), level);
}

static void ilk_compute_wm_maximums(const struct drm_device *dev,
                                    int level,
                                    const struct intel_wm_config *config,
                                    enum intel_ddb_partitioning ddb_partitioning,
                                    struct ilk_wm_maximums *max)
{
        max->pri = ilk_plane_wm_max(dev, level, config, ddb_partitioning, false);
        max->spr = ilk_plane_wm_max(dev, level, config, ddb_partitioning, true);
        max->cur = ilk_cursor_wm_max(dev, level, config);
        max->fbc = ilk_fbc_wm_reg_max(to_i915(dev));
}

static void ilk_compute_wm_reg_maximums(const struct drm_i915_private *dev_priv,
                                        int level,
                                        struct ilk_wm_maximums *max)
{
        max->pri = ilk_plane_wm_reg_max(dev_priv, level, false);
        max->spr = ilk_plane_wm_reg_max(dev_priv, level, true);
        max->cur = ilk_cursor_wm_reg_max(dev_priv, level);
        max->fbc = ilk_fbc_wm_reg_max(dev_priv);
}

static bool ilk_validate_wm_level(int level,
                                  const struct ilk_wm_maximums *max,
                                  struct intel_wm_level *result)
{
        bool ret;

        /* already determined to be invalid? */
        if (!result->enable)
                return false;

        result->enable = result->pri_val <= max->pri &&
                         result->spr_val <= max->spr &&
                         result->cur_val <= max->cur;

        ret = result->enable;

        /*
         * HACK until we can pre-compute everything,
         * and thus fail gracefully if LP0 watermarks
         * are exceeded...
         */
        if (level == 0 && !result->enable) {
                if (result->pri_val > max->pri)
                        DRM_DEBUG_KMS("Primary WM%d too large %u (max %u)\n",
                                      level, result->pri_val, max->pri);
                if (result->spr_val > max->spr)
                        DRM_DEBUG_KMS("Sprite WM%d too large %u (max %u)\n",
                                      level, result->spr_val, max->spr);
                if (result->cur_val > max->cur)
                        DRM_DEBUG_KMS("Cursor WM%d too large %u (max %u)\n",
                                      level, result->cur_val, max->cur);

                result->pri_val = min_t(uint32_t, result->pri_val, max->pri);
                result->spr_val = min_t(uint32_t, result->spr_val, max->spr);
                result->cur_val = min_t(uint32_t, result->cur_val, max->cur);
                result->enable = true;
        }

        return ret;
}

static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
                                 const struct intel_crtc *intel_crtc,
                                 int level,
                                 struct intel_crtc_state *cstate,
                                 struct intel_plane_state *pristate,
                                 struct intel_plane_state *sprstate,
                                 struct intel_plane_state *curstate,
                                 struct intel_wm_level *result)
{
        uint16_t pri_latency = dev_priv->wm.pri_latency[level];
        uint16_t spr_latency = dev_priv->wm.spr_latency[level];
        uint16_t cur_latency = dev_priv->wm.cur_latency[level];

        /* WM1+ latency values stored in 0.5us units */
        if (level > 0) {
                pri_latency *= 5;
                spr_latency *= 5;
                cur_latency *= 5;
        }

        if (pristate) {
                result->pri_val = ilk_compute_pri_wm(cstate, pristate,
                                                     pri_latency, level);
                result->fbc_val = ilk_compute_fbc_wm(cstate, pristate, result->pri_val);
        }

        if (sprstate)
                result->spr_val = ilk_compute_spr_wm(cstate, sprstate, spr_latency);

        if (curstate)
                result->cur_val = ilk_compute_cur_wm(cstate, curstate, cur_latency);

        result->enable = true;
}

static uint32_t
hsw_compute_linetime_wm(const struct intel_crtc_state *cstate)
{
        const struct intel_atomic_state *intel_state =
                to_intel_atomic_state(cstate->base.state);
        const struct drm_display_mode *adjusted_mode =
                &cstate->base.adjusted_mode;
        u32 linetime, ips_linetime;

        if (!cstate->base.active)
                return 0;
        if (WARN_ON(adjusted_mode->crtc_clock == 0))
                return 0;
        if (WARN_ON(intel_state->cdclk.logical.cdclk == 0))
                return 0;

        /* The WM are computed with base on how long it takes to fill a single
         * row at the given clock rate, multiplied by 8.
         * */
        linetime = DIV_ROUND_CLOSEST(adjusted_mode->crtc_htotal * 1000 * 8,
                                     adjusted_mode->crtc_clock);
        ips_linetime = DIV_ROUND_CLOSEST(adjusted_mode->crtc_htotal * 1000 * 8,
                                         intel_state->cdclk.logical.cdclk);

        return PIPE_WM_LINETIME_IPS_LINETIME(ips_linetime) |
               PIPE_WM_LINETIME_TIME(linetime);
}

static void intel_read_wm_latency(struct drm_i915_private *dev_priv,
                                  uint16_t wm[8])
{
        if (INTEL_GEN(dev_priv) >= 9) {
                uint32_t val;
                int ret, i;
                int level, max_level = ilk_wm_max_level(dev_priv);

                /* read the first set of memory latencies[0:3] */
                val = 0; /* data0 to be programmed to 0 for first set */
                mutex_lock(&dev_priv->rps.hw_lock);
                ret = sandybridge_pcode_read(dev_priv,
                                             GEN9_PCODE_READ_MEM_LATENCY,
                                             &val);
                mutex_unlock(&dev_priv->rps.hw_lock);

                if (ret) {
                        DRM_ERROR("SKL Mailbox read error = %d\n", ret);
                        return;
                }

                wm[0] = val & GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[1] = (val >> GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[2] = (val >> GEN9_MEM_LATENCY_LEVEL_2_6_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[3] = (val >> GEN9_MEM_LATENCY_LEVEL_3_7_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;

                /* read the second set of memory latencies[4:7] */
                val = 1; /* data0 to be programmed to 1 for second set */
                mutex_lock(&dev_priv->rps.hw_lock);
                ret = sandybridge_pcode_read(dev_priv,
                                             GEN9_PCODE_READ_MEM_LATENCY,
                                             &val);
                mutex_unlock(&dev_priv->rps.hw_lock);
                if (ret) {
                        DRM_ERROR("SKL Mailbox read error = %d\n", ret);
                        return;
                }

                wm[4] = val & GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[5] = (val >> GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[6] = (val >> GEN9_MEM_LATENCY_LEVEL_2_6_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;
                wm[7] = (val >> GEN9_MEM_LATENCY_LEVEL_3_7_SHIFT) &
                                GEN9_MEM_LATENCY_LEVEL_MASK;

                /*
                 * If a level n (n > 1) has a 0us latency, all levels m (m >= n)
                 * need to be disabled. We make sure to sanitize the values out
                 * of the punit to satisfy this requirement.
                 */
                for (level = 1; level <= max_level; level++) {
                        if (wm[level] == 0) {
                                for (i = level + 1; i <= max_level; i++)
                                        wm[i] = 0;
                                break;
                        }
                }

                /*
                 * WaWmMemoryReadLatency:skl+,glk
                 *
                 * punit doesn't take into account the read latency so we need
                 * to add 2us to the various latency levels we retrieve from the
                 * punit when level 0 response data us 0us.
                 */
                if (wm[0] == 0) {
                        wm[0] += 2;
                        for (level = 1; level <= max_level; level++) {
                                if (wm[level] == 0)
                                        break;
                                wm[level] += 2;
                        }
                }

        } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
                uint64_t sskpd = I915_READ64(MCH_SSKPD);

                wm[0] = (sskpd >> 56) & 0xFF;
                if (wm[0] == 0)
                        wm[0] = sskpd & 0xF;
                wm[1] = (sskpd >> 4) & 0xFF;
                wm[2] = (sskpd >> 12) & 0xFF;
                wm[3] = (sskpd >> 20) & 0x1FF;
                wm[4] = (sskpd >> 32) & 0x1FF;
        } else if (INTEL_GEN(dev_priv) >= 6) {
                uint32_t sskpd = I915_READ(MCH_SSKPD);

                wm[0] = (sskpd >> SSKPD_WM0_SHIFT) & SSKPD_WM_MASK;
                wm[1] = (sskpd >> SSKPD_WM1_SHIFT) & SSKPD_WM_MASK;
                wm[2] = (sskpd >> SSKPD_WM2_SHIFT) & SSKPD_WM_MASK;
                wm[3] = (sskpd >> SSKPD_WM3_SHIFT) & SSKPD_WM_MASK;
        } else if (INTEL_GEN(dev_priv) >= 5) {
                uint32_t mltr = I915_READ(MLTR_ILK);

                /* ILK primary LP0 latency is 700 ns */
                wm[0] = 7;
                wm[1] = (mltr >> MLTR_WM1_SHIFT) & ILK_SRLT_MASK;
                wm[2] = (mltr >> MLTR_WM2_SHIFT) & ILK_SRLT_MASK;
        } else {
                MISSING_CASE(INTEL_DEVID(dev_priv));
        }
}

static void intel_fixup_spr_wm_latency(struct drm_i915_private *dev_priv,
                                       uint16_t wm[5])
{
        /* ILK sprite LP0 latency is 1300 ns */
        if (IS_GEN5(dev_priv))
                wm[0] = 13;
}

static void intel_fixup_cur_wm_latency(struct drm_i915_private *dev_priv,
                                       uint16_t wm[5])
{
        /* ILK cursor LP0 latency is 1300 ns */
        if (IS_GEN5(dev_priv))
                wm[0] = 13;

        /* WaDoubleCursorLP3Latency:ivb */
        if (IS_IVYBRIDGE(dev_priv))
                wm[3] *= 2;
}

int ilk_wm_max_level(const struct drm_i915_private *dev_priv)
{
        /* how many WM levels are we expecting */
        if (INTEL_GEN(dev_priv) >= 9)
                return 7;
        else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                return 4;
        else if (INTEL_GEN(dev_priv) >= 6)
                return 3;
        else
                return 2;
}

static void intel_print_wm_latency(struct drm_i915_private *dev_priv,
                                   const char *name,
                                   const uint16_t wm[8])
{
        int level, max_level = ilk_wm_max_level(dev_priv);

        for (level = 0; level <= max_level; level++) {
                unsigned int latency = wm[level];

                if (latency == 0) {
                        DRM_ERROR("%s WM%d latency not provided\n",
                                  name, level);
                        continue;
                }

                /*
                 * - latencies are in us on gen9.
                 * - before then, WM1+ latency values are in 0.5us units
                 */
                if (INTEL_GEN(dev_priv) >= 9)
                        latency *= 10;
                else if (level > 0)
                        latency *= 5;

                DRM_DEBUG_KMS("%s WM%d latency %u (%u.%u usec)\n",
                              name, level, wm[level],
                              latency / 10, latency % 10);
        }
}

static bool ilk_increase_wm_latency(struct drm_i915_private *dev_priv,
                                    uint16_t wm[5], uint16_t min)
{
        int level, max_level = ilk_wm_max_level(dev_priv);

        if (wm[0] >= min)
                return false;

        wm[0] = max(wm[0], min);
        for (level = 1; level <= max_level; level++)
                wm[level] = max_t(uint16_t, wm[level], DIV_ROUND_UP(min, 5));

        return true;
}

static void snb_wm_latency_quirk(struct drm_i915_private *dev_priv)
{
        bool changed;

        /*
         * The BIOS provided WM memory latency values are often
         * inadequate for high resolution displays. Adjust them.
         */
        changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 12) |
                ilk_increase_wm_latency(dev_priv, dev_priv->wm.spr_latency, 12) |
                ilk_increase_wm_latency(dev_priv, dev_priv->wm.cur_latency, 12);

        if (!changed)
                return;

        DRM_DEBUG_KMS("WM latency values increased to avoid potential underruns\n");
        intel_print_wm_latency(dev_priv, "Primary", dev_priv->wm.pri_latency);
        intel_print_wm_latency(dev_priv, "Sprite", dev_priv->wm.spr_latency);
        intel_print_wm_latency(dev_priv, "Cursor", dev_priv->wm.cur_latency);
}

static void ilk_setup_wm_latency(struct drm_i915_private *dev_priv)
{
        intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency);

        memcpy(dev_priv->wm.spr_latency, dev_priv->wm.pri_latency,
               sizeof(dev_priv->wm.pri_latency));
        memcpy(dev_priv->wm.cur_latency, dev_priv->wm.pri_latency,
               sizeof(dev_priv->wm.pri_latency));

        intel_fixup_spr_wm_latency(dev_priv, dev_priv->wm.spr_latency);
        intel_fixup_cur_wm_latency(dev_priv, dev_priv->wm.cur_latency);

        intel_print_wm_latency(dev_priv, "Primary", dev_priv->wm.pri_latency);
        intel_print_wm_latency(dev_priv, "Sprite", dev_priv->wm.spr_latency);
        intel_print_wm_latency(dev_priv, "Cursor", dev_priv->wm.cur_latency);

        if (IS_GEN6(dev_priv))
                snb_wm_latency_quirk(dev_priv);
}

static void skl_setup_wm_latency(struct drm_i915_private *dev_priv)
{
        intel_read_wm_latency(dev_priv, dev_priv->wm.skl_latency);
        intel_print_wm_latency(dev_priv, "Gen9 Plane", dev_priv->wm.skl_latency);
}

static bool ilk_validate_pipe_wm(struct drm_device *dev,
                                 struct intel_pipe_wm *pipe_wm)
{
        /* LP0 watermark maximums depend on this pipe alone */
        const struct intel_wm_config config = {
                .num_pipes_active = 1,
                .sprites_enabled = pipe_wm->sprites_enabled,
                .sprites_scaled = pipe_wm->sprites_scaled,
        };
        struct ilk_wm_maximums max;

        /* LP0 watermarks always use 1/2 DDB partitioning */
        ilk_compute_wm_maximums(dev, 0, &config, INTEL_DDB_PART_1_2, &max);

        /* At least LP0 must be valid */
        if (!ilk_validate_wm_level(0, &max, &pipe_wm->wm[0])) {
                DRM_DEBUG_KMS("LP0 watermark invalid\n");
                return false;
        }

        return true;
}

/* Compute new watermarks for the pipe */
static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
{
        struct drm_atomic_state *state = cstate->base.state;
        struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
        struct intel_pipe_wm *pipe_wm;
        struct drm_device *dev = state->dev;
        const struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_plane *intel_plane;
        struct intel_plane_state *pristate = NULL;
        struct intel_plane_state *sprstate = NULL;
        struct intel_plane_state *curstate = NULL;
        int level, max_level = ilk_wm_max_level(dev_priv), usable_level;
        struct ilk_wm_maximums max;

        pipe_wm = &cstate->wm.ilk.optimal;

        for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
                struct intel_plane_state *ps;

                ps = intel_atomic_get_existing_plane_state(state,
                                                           intel_plane);
                if (!ps)
                        continue;

                if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
                        pristate = ps;
                else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
                        sprstate = ps;
                else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
                        curstate = ps;
        }

        pipe_wm->pipe_enabled = cstate->base.active;
        if (sprstate) {
                pipe_wm->sprites_enabled = sprstate->base.visible;
                pipe_wm->sprites_scaled = sprstate->base.visible &&
                        (drm_rect_width(&sprstate->base.dst) != drm_rect_width(&sprstate->base.src) >> 16 ||
                         drm_rect_height(&sprstate->base.dst) != drm_rect_height(&sprstate->base.src) >> 16);
        }

        usable_level = max_level;

        /* ILK/SNB: LP2+ watermarks only w/o sprites */
        if (INTEL_GEN(dev_priv) <= 6 && pipe_wm->sprites_enabled)
                usable_level = 1;

        /* ILK/SNB/IVB: LP1+ watermarks only w/o scaling */
        if (pipe_wm->sprites_scaled)
                usable_level = 0;

        ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
                             pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);

        memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
        pipe_wm->wm[0] = pipe_wm->raw_wm[0];

        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                pipe_wm->linetime = hsw_compute_linetime_wm(cstate);

        if (!ilk_validate_pipe_wm(dev, pipe_wm))
                return -EINVAL;

        ilk_compute_wm_reg_maximums(dev_priv, 1, &max);

        for (level = 1; level <= max_level; level++) {
                struct intel_wm_level *wm = &pipe_wm->raw_wm[level];

                ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
                                     pristate, sprstate, curstate, wm);

                /*
                 * Disable any watermark level that exceeds the
                 * register maximums since such watermarks are
                 * always invalid.
                 */
                if (level > usable_level)
                        continue;

                if (ilk_validate_wm_level(level, &max, wm))
                        pipe_wm->wm[level] = *wm;
                else
                        usable_level = level;
        }

        return 0;
}

/*
 * Build a set of 'intermediate' watermark values that satisfy both the old
 * state and the new state.  These can be programmed to the hardware
 * immediately.
 */
static int ilk_compute_intermediate_wm(struct drm_device *dev,
                                       struct intel_crtc *intel_crtc,
                                       struct intel_crtc_state *newstate)
{
        struct intel_pipe_wm *a = &newstate->wm.ilk.intermediate;
        struct intel_pipe_wm *b = &intel_crtc->wm.active.ilk;
        int level, max_level = ilk_wm_max_level(to_i915(dev));

        /*
         * Start with the final, target watermarks, then combine with the
         * currently active watermarks to get values that are safe both before
         * and after the vblank.
         */
        *a = newstate->wm.ilk.optimal;
        a->pipe_enabled |= b->pipe_enabled;
        a->sprites_enabled |= b->sprites_enabled;
        a->sprites_scaled |= b->sprites_scaled;

        for (level = 0; level <= max_level; level++) {
                struct intel_wm_level *a_wm = &a->wm[level];
                const struct intel_wm_level *b_wm = &b->wm[level];

                a_wm->enable &= b_wm->enable;
                a_wm->pri_val = max(a_wm->pri_val, b_wm->pri_val);
                a_wm->spr_val = max(a_wm->spr_val, b_wm->spr_val);
                a_wm->cur_val = max(a_wm->cur_val, b_wm->cur_val);
                a_wm->fbc_val = max(a_wm->fbc_val, b_wm->fbc_val);
        }

        /*
         * We need to make sure that these merged watermark values are
         * actually a valid configuration themselves.  If they're not,
         * there's no safe way to transition from the old state to
         * the new state, so we need to fail the atomic transaction.
         */
        if (!ilk_validate_pipe_wm(dev, a))
                return -EINVAL;

        /*
         * If our intermediate WM are identical to the final WM, then we can
         * omit the post-vblank programming; only update if it's different.
         */
        if (memcmp(a, &newstate->wm.ilk.optimal, sizeof(*a)) != 0)
                newstate->wm.need_postvbl_update = true;

        return 0;
}

/*
 * Merge the watermarks from all active pipes for a specific level.
 */
static void ilk_merge_wm_level(struct drm_device *dev,
                               int level,
                               struct intel_wm_level *ret_wm)
{
        const struct intel_crtc *intel_crtc;

        ret_wm->enable = true;

        for_each_intel_crtc(dev, intel_crtc) {
                const struct intel_pipe_wm *active = &intel_crtc->wm.active.ilk;
                const struct intel_wm_level *wm = &active->wm[level];

                if (!active->pipe_enabled)
                        continue;

                /*
                 * The watermark values may have been used in the past,
                 * so we must maintain them in the registers for some
                 * time even if the level is now disabled.
                 */
                if (!wm->enable)
                        ret_wm->enable = false;

                ret_wm->pri_val = max(ret_wm->pri_val, wm->pri_val);
                ret_wm->spr_val = max(ret_wm->spr_val, wm->spr_val);
                ret_wm->cur_val = max(ret_wm->cur_val, wm->cur_val);
                ret_wm->fbc_val = max(ret_wm->fbc_val, wm->fbc_val);
        }
}

/*
 * Merge all low power watermarks for all active pipes.
 */
static void ilk_wm_merge(struct drm_device *dev,
                         const struct intel_wm_config *config,
                         const struct ilk_wm_maximums *max,
                         struct intel_pipe_wm *merged)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        int level, max_level = ilk_wm_max_level(dev_priv);
        int last_enabled_level = max_level;

        /* ILK/SNB/IVB: LP1+ watermarks only w/ single pipe */
        if ((INTEL_GEN(dev_priv) <= 6 || IS_IVYBRIDGE(dev_priv)) &&
            config->num_pipes_active > 1)
                last_enabled_level = 0;

        /* ILK: FBC WM must be disabled always */
        merged->fbc_wm_enabled = INTEL_GEN(dev_priv) >= 6;

        /* merge each WM1+ level */
        for (level = 1; level <= max_level; level++) {
                struct intel_wm_level *wm = &merged->wm[level];

                ilk_merge_wm_level(dev, level, wm);

                if (level > last_enabled_level)
                        wm->enable = false;
                else if (!ilk_validate_wm_level(level, max, wm))
                        /* make sure all following levels get disabled */
                        last_enabled_level = level - 1;

                /*
                 * The spec says it is preferred to disable
                 * FBC WMs instead of disabling a WM level.
                 */
                if (wm->fbc_val > max->fbc) {
                        if (wm->enable)
                                merged->fbc_wm_enabled = false;
                        wm->fbc_val = 0;
                }
        }

        /* ILK: LP2+ must be disabled when FBC WM is disabled but FBC enabled */
        /*
         * FIXME this is racy. FBC might get enabled later.
         * What we should check here is whether FBC can be
         * enabled sometime later.
         */
        if (IS_GEN5(dev_priv) && !merged->fbc_wm_enabled &&
            intel_fbc_is_active(dev_priv)) {
                for (level = 2; level <= max_level; level++) {
                        struct intel_wm_level *wm = &merged->wm[level];

                        wm->enable = false;
                }
        }
}

static int ilk_wm_lp_to_level(int wm_lp, const struct intel_pipe_wm *pipe_wm)
{
        /* LP1,LP2,LP3 levels are either 1,2,3 or 1,3,4 */
        return wm_lp + (wm_lp >= 2 && pipe_wm->wm[4].enable);
}

/* The value we need to program into the WM_LPx latency field */
static unsigned int ilk_wm_lp_latency(struct drm_device *dev, int level)
{
        struct drm_i915_private *dev_priv = to_i915(dev);

        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                return 2 * level;
        else
                return dev_priv->wm.pri_latency[level];
}

static void ilk_compute_wm_results(struct drm_device *dev,
                                   const struct intel_pipe_wm *merged,
                                   enum intel_ddb_partitioning partitioning,
                                   struct ilk_wm_values *results)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_crtc *intel_crtc;
        int level, wm_lp;

        results->enable_fbc_wm = merged->fbc_wm_enabled;
        results->partitioning = partitioning;

        /* LP1+ register values */
        for (wm_lp = 1; wm_lp <= 3; wm_lp++) {
                const struct intel_wm_level *r;

                level = ilk_wm_lp_to_level(wm_lp, merged);

                r = &merged->wm[level];

                /*
                 * Maintain the watermark values even if the level is
                 * disabled. Doing otherwise could cause underruns.
                 */
                results->wm_lp[wm_lp - 1] =
                        (ilk_wm_lp_latency(dev, level) << WM1_LP_LATENCY_SHIFT) |
                        (r->pri_val << WM1_LP_SR_SHIFT) |
                        r->cur_val;

                if (r->enable)
                        results->wm_lp[wm_lp - 1] |= WM1_LP_SR_EN;

                if (INTEL_GEN(dev_priv) >= 8)
                        results->wm_lp[wm_lp - 1] |=
                                r->fbc_val << WM1_LP_FBC_SHIFT_BDW;
                else
                        results->wm_lp[wm_lp - 1] |=
                                r->fbc_val << WM1_LP_FBC_SHIFT;

                /*
                 * Always set WM1S_LP_EN when spr_val != 0, even if the
                 * level is disabled. Doing otherwise could cause underruns.
                 */
                if (INTEL_GEN(dev_priv) <= 6 && r->spr_val) {
                        WARN_ON(wm_lp != 1);
                        results->wm_lp_spr[wm_lp - 1] = WM1S_LP_EN | r->spr_val;
                } else
                        results->wm_lp_spr[wm_lp - 1] = r->spr_val;
        }

        /* LP0 register values */
        for_each_intel_crtc(dev, intel_crtc) {
                enum pipe pipe = intel_crtc->pipe;
                const struct intel_wm_level *r =
                        &intel_crtc->wm.active.ilk.wm[0];

                if (WARN_ON(!r->enable))
                        continue;

                results->wm_linetime[pipe] = intel_crtc->wm.active.ilk.linetime;

                results->wm_pipe[pipe] =
                        (r->pri_val << WM0_PIPE_PLANE_SHIFT) |
                        (r->spr_val << WM0_PIPE_SPRITE_SHIFT) |
                        r->cur_val;
        }
}

/* Find the result with the highest level enabled. Check for enable_fbc_wm in
 * case both are at the same level. Prefer r1 in case they're the same. */
static struct intel_pipe_wm *ilk_find_best_result(struct drm_device *dev,
                                                  struct intel_pipe_wm *r1,
                                                  struct intel_pipe_wm *r2)
{
        int level, max_level = ilk_wm_max_level(to_i915(dev));
        int level1 = 0, level2 = 0;

        for (level = 1; level <= max_level; level++) {
                if (r1->wm[level].enable)
                        level1 = level;
                if (r2->wm[level].enable)
                        level2 = level;
        }

        if (level1 == level2) {
                if (r2->fbc_wm_enabled && !r1->fbc_wm_enabled)
                        return r2;
                else
                        return r1;
        } else if (level1 > level2) {
                return r1;
        } else {
                return r2;
        }
}

/* dirty bits used to track which watermarks need changes */
#define WM_DIRTY_PIPE(pipe) (1 << (pipe))
#define WM_DIRTY_LINETIME(pipe) (1 << (8 + (pipe)))
#define WM_DIRTY_LP(wm_lp) (1 << (15 + (wm_lp)))
#define WM_DIRTY_LP_ALL (WM_DIRTY_LP(1) | WM_DIRTY_LP(2) | WM_DIRTY_LP(3))
#define WM_DIRTY_FBC (1 << 24)
#define WM_DIRTY_DDB (1 << 25)

static unsigned int ilk_compute_wm_dirty(struct drm_i915_private *dev_priv,
                                         const struct ilk_wm_values *old,
                                         const struct ilk_wm_values *new)
{
        unsigned int dirty = 0;
        enum pipe pipe;
        int wm_lp;

        for_each_pipe(dev_priv, pipe) {
                if (old->wm_linetime[pipe] != new->wm_linetime[pipe]) {
                        dirty |= WM_DIRTY_LINETIME(pipe);
                        /* Must disable LP1+ watermarks too */
                        dirty |= WM_DIRTY_LP_ALL;
                }

                if (old->wm_pipe[pipe] != new->wm_pipe[pipe]) {
                        dirty |= WM_DIRTY_PIPE(pipe);
                        /* Must disable LP1+ watermarks too */
                        dirty |= WM_DIRTY_LP_ALL;
                }
        }

        if (old->enable_fbc_wm != new->enable_fbc_wm) {
                dirty |= WM_DIRTY_FBC;
                /* Must disable LP1+ watermarks too */
                dirty |= WM_DIRTY_LP_ALL;
        }

        if (old->partitioning != new->partitioning) {
                dirty |= WM_DIRTY_DDB;
                /* Must disable LP1+ watermarks too */
                dirty |= WM_DIRTY_LP_ALL;
        }

        /* LP1+ watermarks already deemed dirty, no need to continue */
        if (dirty & WM_DIRTY_LP_ALL)
                return dirty;

        /* Find the lowest numbered LP1+ watermark in need of an update... */
        for (wm_lp = 1; wm_lp <= 3; wm_lp++) {
                if (old->wm_lp[wm_lp - 1] != new->wm_lp[wm_lp - 1] ||
                    old->wm_lp_spr[wm_lp - 1] != new->wm_lp_spr[wm_lp - 1])
                        break;
        }

        /* ...and mark it and all higher numbered LP1+ watermarks as dirty */
        for (; wm_lp <= 3; wm_lp++)
                dirty |= WM_DIRTY_LP(wm_lp);

        return dirty;
}

static bool _ilk_disable_lp_wm(struct drm_i915_private *dev_priv,
                               unsigned int dirty)
{
        struct ilk_wm_values *previous = &dev_priv->wm.hw;
        bool changed = false;

        if (dirty & WM_DIRTY_LP(3) && previous->wm_lp[2] & WM1_LP_SR_EN) {
                previous->wm_lp[2] &= ~WM1_LP_SR_EN;
                I915_WRITE(WM3_LP_ILK, previous->wm_lp[2]);
                changed = true;
        }
        if (dirty & WM_DIRTY_LP(2) && previous->wm_lp[1] & WM1_LP_SR_EN) {
                previous->wm_lp[1] &= ~WM1_LP_SR_EN;
                I915_WRITE(WM2_LP_ILK, previous->wm_lp[1]);
                changed = true;
        }
        if (dirty & WM_DIRTY_LP(1) && previous->wm_lp[0] & WM1_LP_SR_EN) {
                previous->wm_lp[0] &= ~WM1_LP_SR_EN;
                I915_WRITE(WM1_LP_ILK, previous->wm_lp[0]);
                changed = true;
        }

        /*
         * Don't touch WM1S_LP_EN here.
         * Doing so could cause underruns.
         */

        return changed;
}

/*
 * The spec says we shouldn't write when we don't need, because every write
 * causes WMs to be re-evaluated, expending some power.
 */
static void ilk_write_wm_values(struct drm_i915_private *dev_priv,
                                struct ilk_wm_values *results)
{
        struct ilk_wm_values *previous = &dev_priv->wm.hw;
        unsigned int dirty;
        uint32_t val;

        dirty = ilk_compute_wm_dirty(dev_priv, previous, results);
        if (!dirty)
                return;

        _ilk_disable_lp_wm(dev_priv, dirty);

        if (dirty & WM_DIRTY_PIPE(PIPE_A))
                I915_WRITE(WM0_PIPEA_ILK, results->wm_pipe[0]);
        if (dirty & WM_DIRTY_PIPE(PIPE_B))
                I915_WRITE(WM0_PIPEB_ILK, results->wm_pipe[1]);
        if (dirty & WM_DIRTY_PIPE(PIPE_C))
                I915_WRITE(WM0_PIPEC_IVB, results->wm_pipe[2]);

        if (dirty & WM_DIRTY_LINETIME(PIPE_A))
                I915_WRITE(PIPE_WM_LINETIME(PIPE_A), results->wm_linetime[0]);
        if (dirty & WM_DIRTY_LINETIME(PIPE_B))
                I915_WRITE(PIPE_WM_LINETIME(PIPE_B), results->wm_linetime[1]);
        if (dirty & WM_DIRTY_LINETIME(PIPE_C))
                I915_WRITE(PIPE_WM_LINETIME(PIPE_C), results->wm_linetime[2]);

        if (dirty & WM_DIRTY_DDB) {
                if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
                        val = I915_READ(WM_MISC);
                        if (results->partitioning == INTEL_DDB_PART_1_2)
                                val &= ~WM_MISC_DATA_PARTITION_5_6;
                        else
                                val |= WM_MISC_DATA_PARTITION_5_6;
                        I915_WRITE(WM_MISC, val);
                } else {
                        val = I915_READ(DISP_ARB_CTL2);
                        if (results->partitioning == INTEL_DDB_PART_1_2)
                                val &= ~DISP_DATA_PARTITION_5_6;
                        else
                                val |= DISP_DATA_PARTITION_5_6;
                        I915_WRITE(DISP_ARB_CTL2, val);
                }
        }

        if (dirty & WM_DIRTY_FBC) {
                val = I915_READ(DISP_ARB_CTL);
                if (results->enable_fbc_wm)
                        val &= ~DISP_FBC_WM_DIS;
                else
                        val |= DISP_FBC_WM_DIS;
                I915_WRITE(DISP_ARB_CTL, val);
        }

        if (dirty & WM_DIRTY_LP(1) &&
            previous->wm_lp_spr[0] != results->wm_lp_spr[0])
                I915_WRITE(WM1S_LP_ILK, results->wm_lp_spr[0]);

        if (INTEL_GEN(dev_priv) >= 7) {
                if (dirty & WM_DIRTY_LP(2) && previous->wm_lp_spr[1] != results->wm_lp_spr[1])
                        I915_WRITE(WM2S_LP_IVB, results->wm_lp_spr[1]);
                if (dirty & WM_DIRTY_LP(3) && previous->wm_lp_spr[2] != results->wm_lp_spr[2])
                        I915_WRITE(WM3S_LP_IVB, results->wm_lp_spr[2]);
        }

        if (dirty & WM_DIRTY_LP(1) && previous->wm_lp[0] != results->wm_lp[0])
                I915_WRITE(WM1_LP_ILK, results->wm_lp[0]);
        if (dirty & WM_DIRTY_LP(2) && previous->wm_lp[1] != results->wm_lp[1])
                I915_WRITE(WM2_LP_ILK, results->wm_lp[1]);
        if (dirty & WM_DIRTY_LP(3) && previous->wm_lp[2] != results->wm_lp[2])
                I915_WRITE(WM3_LP_ILK, results->wm_lp[2]);

        dev_priv->wm.hw = *results;
}

bool ilk_disable_lp_wm(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);

        return _ilk_disable_lp_wm(dev_priv, WM_DIRTY_LP_ALL);
}

/*
 * FIXME: We still don't have the proper code detect if we need to apply the WA,
 * so assume we'll always need it in order to avoid underruns.
 */
static bool skl_needs_memory_bw_wa(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);

        if (IS_GEN9_BC(dev_priv) || IS_BROXTON(dev_priv))
                return true;

        return false;
}

static bool
intel_has_sagv(struct drm_i915_private *dev_priv)
{
        if (IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv) ||
            IS_CANNONLAKE(dev_priv))
                return true;

        if (IS_SKYLAKE(dev_priv) &&
            dev_priv->sagv_status != I915_SAGV_NOT_CONTROLLED)
                return true;

        return false;
}

/*
 * SAGV dynamically adjusts the system agent voltage and clock frequencies
 * depending on power and performance requirements. The display engine access
 * to system memory is blocked during the adjustment time. Because of the
 * blocking time, having this enabled can cause full system hangs and/or pipe
 * underruns if we don't meet all of the following requirements:
 *
 *  - <= 1 pipe enabled
 *  - All planes can enable watermarks for latencies >= SAGV engine block time
 *  - We're not using an interlaced display configuration
 */
int
intel_enable_sagv(struct drm_i915_private *dev_priv)
{
        int ret;

        if (!intel_has_sagv(dev_priv))
                return 0;

        if (dev_priv->sagv_status == I915_SAGV_ENABLED)
                return 0;

        DRM_DEBUG_KMS("Enabling the SAGV\n");
        mutex_lock(&dev_priv->rps.hw_lock);

        ret = sandybridge_pcode_write(dev_priv, GEN9_PCODE_SAGV_CONTROL,
                                      GEN9_SAGV_ENABLE);

        /* We don't need to wait for the SAGV when enabling */
        mutex_unlock(&dev_priv->rps.hw_lock);

        /*
         * Some skl systems, pre-release machines in particular,
         * don't actually have an SAGV.
         */
        if (IS_SKYLAKE(dev_priv) && ret == -ENXIO) {
                DRM_DEBUG_DRIVER("No SAGV found on system, ignoring\n");
                dev_priv->sagv_status = I915_SAGV_NOT_CONTROLLED;
                return 0;
        } else if (ret < 0) {
                DRM_ERROR("Failed to enable the SAGV\n");
                return ret;
        }

        dev_priv->sagv_status = I915_SAGV_ENABLED;
        return 0;
}

int
intel_disable_sagv(struct drm_i915_private *dev_priv)
{
        int ret;

        if (!intel_has_sagv(dev_priv))
                return 0;

        if (dev_priv->sagv_status == I915_SAGV_DISABLED)
                return 0;

        DRM_DEBUG_KMS("Disabling the SAGV\n");
        mutex_lock(&dev_priv->rps.hw_lock);

        /* bspec says to keep retrying for at least 1 ms */
        ret = skl_pcode_request(dev_priv, GEN9_PCODE_SAGV_CONTROL,
                                GEN9_SAGV_DISABLE,
                                GEN9_SAGV_IS_DISABLED, GEN9_SAGV_IS_DISABLED,
                                1);
        mutex_unlock(&dev_priv->rps.hw_lock);

        /*
         * Some skl systems, pre-release machines in particular,
         * don't actually have an SAGV.
         */
        if (IS_SKYLAKE(dev_priv) && ret == -ENXIO) {
                DRM_DEBUG_DRIVER("No SAGV found on system, ignoring\n");
                dev_priv->sagv_status = I915_SAGV_NOT_CONTROLLED;
                return 0;
        } else if (ret < 0) {
                DRM_ERROR("Failed to disable the SAGV (%d)\n", ret);
                return ret;
        }

        dev_priv->sagv_status = I915_SAGV_DISABLED;
        return 0;
}

bool intel_can_enable_sagv(struct drm_atomic_state *state)
{
        struct drm_device *dev = state->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct intel_crtc *crtc;
        struct intel_plane *plane;
        struct intel_crtc_state *cstate;
        enum pipe pipe;
        int level, latency;
        int sagv_block_time_us = IS_GEN9(dev_priv) ? 30 : 20;

        if (!intel_has_sagv(dev_priv))
                return false;

        /*
         * SKL+ workaround: bspec recommends we disable the SAGV when we have
         * more then one pipe enabled
         *
         * If there are no active CRTCs, no additional checks need be performed
         */
        if (hweight32(intel_state->active_crtcs) == 0)
                return true;
        else if (hweight32(intel_state->active_crtcs) > 1)
                return false;

        /* Since we're now guaranteed to only have one active CRTC... */
        pipe = ffs(intel_state->active_crtcs) - 1;
        crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
        cstate = to_intel_crtc_state(crtc->base.state);

        if (crtc->base.state->adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
                return false;

        for_each_intel_plane_on_crtc(dev, crtc, plane) {
                struct skl_plane_wm *wm =
                        &cstate->wm.skl.optimal.planes[plane->id];

                /* Skip this plane if it's not enabled */
                if (!wm->wm[0].plane_en)
                        continue;

                /* Find the highest enabled wm level for this plane */
                for (level = ilk_wm_max_level(dev_priv);
                     !wm->wm[level].plane_en; --level)
                     { }

                latency = dev_priv->wm.skl_latency[level];

                if (skl_needs_memory_bw_wa(intel_state) &&
                    plane->base.state->fb->modifier ==
                    I915_FORMAT_MOD_X_TILED)
                        latency += 15;

                /*
                 * If any of the planes on this pipe don't enable wm levels that
                 * incur memory latencies higher than sagv_block_time_us we
                 * can't enable the SAGV.
                 */
                if (latency < sagv_block_time_us)
                        return false;
        }

        return true;
}

static void
skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
                                   const struct intel_crtc_state *cstate,
                                   struct skl_ddb_entry *alloc, /* out */
                                   int *num_active /* out */)
{
        struct drm_atomic_state *state = cstate->base.state;
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct drm_crtc *for_crtc = cstate->base.crtc;
        unsigned int pipe_size, ddb_size;
        int nth_active_pipe;

        if (WARN_ON(!state) || !cstate->base.active) {
                alloc->start = 0;
                alloc->end = 0;
                *num_active = hweight32(dev_priv->active_crtcs);
                return;
        }

        if (intel_state->active_pipe_changes)
                *num_active = hweight32(intel_state->active_crtcs);
        else
                *num_active = hweight32(dev_priv->active_crtcs);

        ddb_size = INTEL_INFO(dev_priv)->ddb_size;
        WARN_ON(ddb_size == 0);

        ddb_size -= 4; /* 4 blocks for bypass path allocation */

        /*
         * If the state doesn't change the active CRTC's, then there's
         * no need to recalculate; the existing pipe allocation limits
         * should remain unchanged.  Note that we're safe from racing
         * commits since any racing commit that changes the active CRTC
         * list would need to grab _all_ crtc locks, including the one
         * we currently hold.
         */
        if (!intel_state->active_pipe_changes) {
                /*
                 * alloc may be cleared by clear_intel_crtc_state,
                 * copy from old state to be sure
                 */
                *alloc = to_intel_crtc_state(for_crtc->state)->wm.skl.ddb;
                return;
        }

        nth_active_pipe = hweight32(intel_state->active_crtcs &
                                    (drm_crtc_mask(for_crtc) - 1));
        pipe_size = ddb_size / hweight32(intel_state->active_crtcs);
        alloc->start = nth_active_pipe * ddb_size / *num_active;
        alloc->end = alloc->start + pipe_size;
}

static unsigned int skl_cursor_allocation(int num_active)
{
        if (num_active == 1)
                return 32;

        return 8;
}

static void skl_ddb_entry_init_from_hw(struct skl_ddb_entry *entry, u32 reg)
{
        entry->start = reg & 0x3ff;
        entry->end = (reg >> 16) & 0x3ff;
        if (entry->end)
                entry->end += 1;
}

void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
                          struct skl_ddb_allocation *ddb /* out */)
{
        struct intel_crtc *crtc;

        memset(ddb, 0, sizeof(*ddb));

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                enum intel_display_power_domain power_domain;
                enum plane_id plane_id;
                enum pipe pipe = crtc->pipe;

                power_domain = POWER_DOMAIN_PIPE(pipe);
                if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
                        continue;

                for_each_plane_id_on_crtc(crtc, plane_id) {
                        u32 val;

                        if (plane_id != PLANE_CURSOR)
                                val = I915_READ(PLANE_BUF_CFG(pipe, plane_id));
                        else
                                val = I915_READ(CUR_BUF_CFG(pipe));

                        skl_ddb_entry_init_from_hw(&ddb->plane[pipe][plane_id], val);
                }

                intel_display_power_put(dev_priv, power_domain);
        }
}

/*
 * Determines the downscale amount of a plane for the purposes of watermark calculations.
 * The bspec defines downscale amount as:
 *
 * """
 * Horizontal down scale amount = maximum[1, Horizontal source size /
 *                                           Horizontal destination size]
 * Vertical down scale amount = maximum[1, Vertical source size /
 *                                         Vertical destination size]
 * Total down scale amount = Horizontal down scale amount *
 *                           Vertical down scale amount
 * """
 *
 * Return value is provided in 16.16 fixed point form to retain fractional part.
 * Caller should take care of dividing & rounding off the value.
 */
static uint_fixed_16_16_t
skl_plane_downscale_amount(const struct intel_crtc_state *cstate,
                           const struct intel_plane_state *pstate)
{
        struct intel_plane *plane = to_intel_plane(pstate->base.plane);
        uint32_t src_w, src_h, dst_w, dst_h;
        uint_fixed_16_16_t fp_w_ratio, fp_h_ratio;
        uint_fixed_16_16_t downscale_h, downscale_w;

        if (WARN_ON(!intel_wm_plane_visible(cstate, pstate)))
                return u32_to_fixed16(0);

        /* n.b., src is 16.16 fixed point, dst is whole integer */
        if (plane->id == PLANE_CURSOR) {
                /*
                 * Cursors only support 0/180 degree rotation,
                 * hence no need to account for rotation here.
                 */
                src_w = pstate->base.src_w >> 16;
                src_h = pstate->base.src_h >> 16;
                dst_w = pstate->base.crtc_w;
                dst_h = pstate->base.crtc_h;
        } else {
                /*
                 * Src coordinates are already rotated by 270 degrees for
                 * the 90/270 degree plane rotation cases (to match the
                 * GTT mapping), hence no need to account for rotation here.
                 */
                src_w = drm_rect_width(&pstate->base.src) >> 16;
                src_h = drm_rect_height(&pstate->base.src) >> 16;
                dst_w = drm_rect_width(&pstate->base.dst);
                dst_h = drm_rect_height(&pstate->base.dst);
        }

        fp_w_ratio = div_fixed16(src_w, dst_w);
        fp_h_ratio = div_fixed16(src_h, dst_h);
        downscale_w = max_fixed16(fp_w_ratio, u32_to_fixed16(1));
        downscale_h = max_fixed16(fp_h_ratio, u32_to_fixed16(1));

        return mul_fixed16(downscale_w, downscale_h);
}

static uint_fixed_16_16_t
skl_pipe_downscale_amount(const struct intel_crtc_state *crtc_state)
{
        uint_fixed_16_16_t pipe_downscale = u32_to_fixed16(1);

        if (!crtc_state->base.enable)
                return pipe_downscale;

        if (crtc_state->pch_pfit.enabled) {
                uint32_t src_w, src_h, dst_w, dst_h;
                uint32_t pfit_size = crtc_state->pch_pfit.size;
                uint_fixed_16_16_t fp_w_ratio, fp_h_ratio;
                uint_fixed_16_16_t downscale_h, downscale_w;

                src_w = crtc_state->pipe_src_w;
                src_h = crtc_state->pipe_src_h;
                dst_w = pfit_size >> 16;
                dst_h = pfit_size & 0xffff;

                if (!dst_w || !dst_h)
                        return pipe_downscale;

                fp_w_ratio = div_fixed16(src_w, dst_w);
                fp_h_ratio = div_fixed16(src_h, dst_h);
                downscale_w = max_fixed16(fp_w_ratio, u32_to_fixed16(1));
                downscale_h = max_fixed16(fp_h_ratio, u32_to_fixed16(1));

                pipe_downscale = mul_fixed16(downscale_w, downscale_h);
        }

        return pipe_downscale;
}

int skl_check_pipe_max_pixel_rate(struct intel_crtc *intel_crtc,
                                  struct intel_crtc_state *cstate)
{
        struct drm_crtc_state *crtc_state = &cstate->base;
        struct drm_atomic_state *state = crtc_state->state;
        struct drm_plane *plane;
        const struct drm_plane_state *pstate;
        struct intel_plane_state *intel_pstate;
        int crtc_clock, dotclk;
        uint32_t pipe_max_pixel_rate;
        uint_fixed_16_16_t pipe_downscale;
        uint_fixed_16_16_t max_downscale = u32_to_fixed16(1);

        if (!cstate->base.enable)
                return 0;

        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, crtc_state) {
                uint_fixed_16_16_t plane_downscale;
                uint_fixed_16_16_t fp_9_div_8 = div_fixed16(9, 8);
                int bpp;

                if (!intel_wm_plane_visible(cstate,
                                            to_intel_plane_state(pstate)))
                        continue;

                if (WARN_ON(!pstate->fb))
                        return -EINVAL;

                intel_pstate = to_intel_plane_state(pstate);
                plane_downscale = skl_plane_downscale_amount(cstate,
                                                             intel_pstate);
                bpp = pstate->fb->format->cpp[0] * 8;
                if (bpp == 64)
                        plane_downscale = mul_fixed16(plane_downscale,
                                                      fp_9_div_8);

                max_downscale = max_fixed16(plane_downscale, max_downscale);
        }
        pipe_downscale = skl_pipe_downscale_amount(cstate);

        pipe_downscale = mul_fixed16(pipe_downscale, max_downscale);

        crtc_clock = crtc_state->adjusted_mode.crtc_clock;
        dotclk = to_intel_atomic_state(state)->cdclk.logical.cdclk;

        if (IS_GEMINILAKE(to_i915(intel_crtc->base.dev)))
                dotclk *= 2;

        pipe_max_pixel_rate = div_round_up_u32_fixed16(dotclk, pipe_downscale);

        if (pipe_max_pixel_rate < crtc_clock) {
                DRM_DEBUG_KMS("Max supported pixel clock with scaling exceeded\n");
                return -EINVAL;
        }

        return 0;
}

static unsigned int
skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
                             const struct drm_plane_state *pstate,
                             int y)
{
        struct intel_plane *plane = to_intel_plane(pstate->plane);
        struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
        uint32_t data_rate;
        uint32_t width = 0, height = 0;
        struct drm_framebuffer *fb;
        u32 format;
        uint_fixed_16_16_t down_scale_amount;

        if (!intel_pstate->base.visible)
                return 0;

        fb = pstate->fb;
        format = fb->format->format;

        if (plane->id == PLANE_CURSOR)
                return 0;
        if (y && format != DRM_FORMAT_NV12)
                return 0;

        /*
         * Src coordinates are already rotated by 270 degrees for
         * the 90/270 degree plane rotation cases (to match the
         * GTT mapping), hence no need to account for rotation here.
         */
        width = drm_rect_width(&intel_pstate->base.src) >> 16;
        height = drm_rect_height(&intel_pstate->base.src) >> 16;

        /* for planar format */
        if (format == DRM_FORMAT_NV12) {
                if (y)  /* y-plane data rate */
                        data_rate = width * height *
                                fb->format->cpp[0];
                else    /* uv-plane data rate */
                        data_rate = (width / 2) * (height / 2) *
                                fb->format->cpp[1];
        } else {
                /* for packed formats */
                data_rate = width * height * fb->format->cpp[0];
        }

        down_scale_amount = skl_plane_downscale_amount(cstate, intel_pstate);

        return mul_round_up_u32_fixed16(data_rate, down_scale_amount);
}

/*
 * We don't overflow 32 bits. Worst case is 3 planes enabled, each fetching
 * a 8192x4096@32bpp framebuffer:
 *   3 * 4096 * 8192  * 4 < 2^32
 */
static unsigned int
skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate,
                                 unsigned *plane_data_rate,
                                 unsigned *plane_y_data_rate)
{
        struct drm_crtc_state *cstate = &intel_cstate->base;
        struct drm_atomic_state *state = cstate->state;
        struct drm_plane *plane;
        const struct drm_plane_state *pstate;
        unsigned int total_data_rate = 0;

        if (WARN_ON(!state))
                return 0;

        /* Calculate and cache data rate for each plane */
        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, cstate) {
                enum plane_id plane_id = to_intel_plane(plane)->id;
                unsigned int rate;

                /* packed/uv */
                rate = skl_plane_relative_data_rate(intel_cstate,
                                                    pstate, 0);
                plane_data_rate[plane_id] = rate;

                total_data_rate += rate;

                /* y-plane */
                rate = skl_plane_relative_data_rate(intel_cstate,
                                                    pstate, 1);
                plane_y_data_rate[plane_id] = rate;

                total_data_rate += rate;
        }

        return total_data_rate;
}

static uint16_t
skl_ddb_min_alloc(const struct drm_plane_state *pstate,
                  const int y)
{
        struct drm_framebuffer *fb = pstate->fb;
        struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
        uint32_t src_w, src_h;
        uint32_t min_scanlines = 8;
        uint8_t plane_bpp;

        if (WARN_ON(!fb))
                return 0;

        /* For packed formats, no y-plane, return 0 */
        if (y && fb->format->format != DRM_FORMAT_NV12)
                return 0;

        /* For Non Y-tile return 8-blocks */
        if (fb->modifier != I915_FORMAT_MOD_Y_TILED &&
            fb->modifier != I915_FORMAT_MOD_Yf_TILED &&
            fb->modifier != I915_FORMAT_MOD_Y_TILED_CCS &&
            fb->modifier != I915_FORMAT_MOD_Yf_TILED_CCS)
                return 8;

        /*
         * Src coordinates are already rotated by 270 degrees for
         * the 90/270 degree plane rotation cases (to match the
         * GTT mapping), hence no need to account for rotation here.
         */
        src_w = drm_rect_width(&intel_pstate->base.src) >> 16;
        src_h = drm_rect_height(&intel_pstate->base.src) >> 16;

        /* Halve UV plane width and height for NV12 */
        if (fb->format->format == DRM_FORMAT_NV12 && !y) {
                src_w /= 2;
                src_h /= 2;
        }

        if (fb->format->format == DRM_FORMAT_NV12 && !y)
                plane_bpp = fb->format->cpp[1];
        else
                plane_bpp = fb->format->cpp[0];

        if (drm_rotation_90_or_270(pstate->rotation)) {
                switch (plane_bpp) {
                case 1:
                        min_scanlines = 32;
                        break;
                case 2:
                        min_scanlines = 16;
                        break;
                case 4:
                        min_scanlines = 8;
                        break;
                case 8:
                        min_scanlines = 4;
                        break;
                default:
                        WARN(1, "Unsupported pixel depth %u for rotation",
                             plane_bpp);
                        min_scanlines = 32;
                }
        }

        return DIV_ROUND_UP((4 * src_w * plane_bpp), 512) * min_scanlines/4 + 3;
}

static void
skl_ddb_calc_min(const struct intel_crtc_state *cstate, int num_active,
                 uint16_t *minimum, uint16_t *y_minimum)
{
        const struct drm_plane_state *pstate;
        struct drm_plane *plane;

        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, &cstate->base) {
                enum plane_id plane_id = to_intel_plane(plane)->id;

                if (plane_id == PLANE_CURSOR)
                        continue;

                if (!pstate->visible)
                        continue;

                minimum[plane_id] = skl_ddb_min_alloc(pstate, 0);
                y_minimum[plane_id] = skl_ddb_min_alloc(pstate, 1);
        }

        minimum[PLANE_CURSOR] = skl_cursor_allocation(num_active);
}

static int
skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
                      struct skl_ddb_allocation *ddb /* out */)
{
        struct drm_atomic_state *state = cstate->base.state;
        struct drm_crtc *crtc = cstate->base.crtc;
        struct drm_device *dev = crtc->dev;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        enum pipe pipe = intel_crtc->pipe;
        struct skl_ddb_entry *alloc = &cstate->wm.skl.ddb;
        uint16_t alloc_size, start;
        uint16_t minimum[I915_MAX_PLANES] = {};
        uint16_t y_minimum[I915_MAX_PLANES] = {};
        unsigned int total_data_rate;
        enum plane_id plane_id;
        int num_active;
        unsigned plane_data_rate[I915_MAX_PLANES] = {};
        unsigned plane_y_data_rate[I915_MAX_PLANES] = {};
        uint16_t total_min_blocks = 0;

        /* Clear the partitioning for disabled planes. */
        memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
        memset(ddb->y_plane[pipe], 0, sizeof(ddb->y_plane[pipe]));

        if (WARN_ON(!state))
                return 0;

        if (!cstate->base.active) {
                alloc->start = alloc->end = 0;
                return 0;
        }

        skl_ddb_get_pipe_allocation_limits(dev, cstate, alloc, &num_active);
        alloc_size = skl_ddb_entry_size(alloc);
        if (alloc_size == 0)
                return 0;

        skl_ddb_calc_min(cstate, num_active, minimum, y_minimum);

        /*
         * 1. Allocate the mininum required blocks for each active plane
         * and allocate the cursor, it doesn't require extra allocation
         * proportional to the data rate.
         */

        for_each_plane_id_on_crtc(intel_crtc, plane_id) {
                total_min_blocks += minimum[plane_id];
                total_min_blocks += y_minimum[plane_id];
        }

        if (total_min_blocks > alloc_size) {
                DRM_DEBUG_KMS("Requested display configuration exceeds system DDB limitations");
                DRM_DEBUG_KMS("minimum required %d/%d\n", total_min_blocks,
                                                        alloc_size);
                return -EINVAL;
        }

        alloc_size -= total_min_blocks;
        ddb->plane[pipe][PLANE_CURSOR].start = alloc->end - minimum[PLANE_CURSOR];
        ddb->plane[pipe][PLANE_CURSOR].end = alloc->end;

        /*
         * 2. Distribute the remaining space in proportion to the amount of
         * data each plane needs to fetch from memory.
         *
         * FIXME: we may not allocate every single block here.
         */
        total_data_rate = skl_get_total_relative_data_rate(cstate,
                                                           plane_data_rate,
                                                           plane_y_data_rate);
        if (total_data_rate == 0)
                return 0;

        start = alloc->start;
        for_each_plane_id_on_crtc(intel_crtc, plane_id) {
                unsigned int data_rate, y_data_rate;
                uint16_t plane_blocks, y_plane_blocks = 0;

                if (plane_id == PLANE_CURSOR)
                        continue;

                data_rate = plane_data_rate[plane_id];

                /*
                 * allocation for (packed formats) or (uv-plane part of planar format):
                 * promote the expression to 64 bits to avoid overflowing, the
                 * result is < available as data_rate / total_data_rate < 1
                 */
                plane_blocks = minimum[plane_id];
                plane_blocks += div_u64((uint64_t)alloc_size * data_rate,
                                        total_data_rate);

                /* Leave disabled planes at (0,0) */
                if (data_rate) {
                        ddb->plane[pipe][plane_id].start = start;
                        ddb->plane[pipe][plane_id].end = start + plane_blocks;
                }

                start += plane_blocks;

                /*
                 * allocation for y_plane part of planar format:
                 */
                y_data_rate = plane_y_data_rate[plane_id];

                y_plane_blocks = y_minimum[plane_id];
                y_plane_blocks += div_u64((uint64_t)alloc_size * y_data_rate,
                                        total_data_rate);

                if (y_data_rate) {
                        ddb->y_plane[pipe][plane_id].start = start;
                        ddb->y_plane[pipe][plane_id].end = start + y_plane_blocks;
                }

                start += y_plane_blocks;
        }

        return 0;
}

/*
 * The max latency should be 257 (max the punit can code is 255 and we add 2us
 * for the read latency) and cpp should always be <= 8, so that
 * should allow pixel_rate up to ~2 GHz which seems sufficient since max
 * 2xcdclk is 1350 MHz and the pixel rate should never exceed that.
*/
static uint_fixed_16_16_t
skl_wm_method1(const struct drm_i915_private *dev_priv, uint32_t pixel_rate,
               uint8_t cpp, uint32_t latency)
{
        uint32_t wm_intermediate_val;
        uint_fixed_16_16_t ret;

        if (latency == 0)
                return FP_16_16_MAX;

        wm_intermediate_val = latency * pixel_rate * cpp;
        ret = div_fixed16(wm_intermediate_val, 1000 * 512);

        if (INTEL_GEN(dev_priv) >= 10)
                ret = add_fixed16_u32(ret, 1);

        return ret;
}

static uint_fixed_16_16_t skl_wm_method2(uint32_t pixel_rate,
                        uint32_t pipe_htotal,
                        uint32_t latency,
                        uint_fixed_16_16_t plane_blocks_per_line)
{
        uint32_t wm_intermediate_val;
        uint_fixed_16_16_t ret;

        if (latency == 0)
                return FP_16_16_MAX;

        wm_intermediate_val = latency * pixel_rate;
        wm_intermediate_val = DIV_ROUND_UP(wm_intermediate_val,
                                           pipe_htotal * 1000);
        ret = mul_u32_fixed16(wm_intermediate_val, plane_blocks_per_line);
        return ret;
}

static uint_fixed_16_16_t
intel_get_linetime_us(struct intel_crtc_state *cstate)
{
        uint32_t pixel_rate;
        uint32_t crtc_htotal;
        uint_fixed_16_16_t linetime_us;

        if (!cstate->base.active)
                return u32_to_fixed16(0);

        pixel_rate = cstate->pixel_rate;

        if (WARN_ON(pixel_rate == 0))
                return u32_to_fixed16(0);

        crtc_htotal = cstate->base.adjusted_mode.crtc_htotal;
        linetime_us = div_fixed16(crtc_htotal * 1000, pixel_rate);

        return linetime_us;
}

static uint32_t
skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cstate,
                              const struct intel_plane_state *pstate)
{
        uint64_t adjusted_pixel_rate;
        uint_fixed_16_16_t downscale_amount;

        /* Shouldn't reach here on disabled planes... */
        if (WARN_ON(!intel_wm_plane_visible(cstate, pstate)))
                return 0;

        /*
         * Adjusted plane pixel rate is just the pipe's adjusted pixel rate
         * with additional adjustments for plane-specific scaling.
         */
        adjusted_pixel_rate = cstate->pixel_rate;
        downscale_amount = skl_plane_downscale_amount(cstate, pstate);

        return mul_round_up_u32_fixed16(adjusted_pixel_rate,
                                            downscale_amount);
}

static int
skl_compute_plane_wm_params(const struct drm_i915_private *dev_priv,
                            struct intel_crtc_state *cstate,
                            const struct intel_plane_state *intel_pstate,
                            struct skl_wm_params *wp)
{
        struct intel_plane *plane = to_intel_plane(intel_pstate->base.plane);
        const struct drm_plane_state *pstate = &intel_pstate->base;
        const struct drm_framebuffer *fb = pstate->fb;
        uint32_t interm_pbpl;
        struct intel_atomic_state *state =
                to_intel_atomic_state(cstate->base.state);
        bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state);

        if (!intel_wm_plane_visible(cstate, intel_pstate))
                return 0;

        wp->y_tiled = fb->modifier == I915_FORMAT_MOD_Y_TILED ||
                      fb->modifier == I915_FORMAT_MOD_Yf_TILED ||
                      fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
                      fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS;
        wp->x_tiled = fb->modifier == I915_FORMAT_MOD_X_TILED;
        wp->rc_surface = fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
                         fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS;

        if (plane->id == PLANE_CURSOR) {
                wp->width = intel_pstate->base.crtc_w;
        } else {
                /*
                 * Src coordinates are already rotated by 270 degrees for
                 * the 90/270 degree plane rotation cases (to match the
                 * GTT mapping), hence no need to account for rotation here.
                 */
                wp->width = drm_rect_width(&intel_pstate->base.src) >> 16;
        }

        wp->cpp = (fb->format->format == DRM_FORMAT_NV12) ? fb->format->cpp[1] :
                                                            fb->format->cpp[0];
        wp->plane_pixel_rate = skl_adjusted_plane_pixel_rate(cstate,
                                                             intel_pstate);

        if (drm_rotation_90_or_270(pstate->rotation)) {

                switch (wp->cpp) {
                case 1:
                        wp->y_min_scanlines = 16;
                        break;
                case 2:
                        wp->y_min_scanlines = 8;
                        break;
                case 4:
                        wp->y_min_scanlines = 4;
                        break;
                default:
                        MISSING_CASE(wp->cpp);
                        return -EINVAL;
                }
        } else {
                wp->y_min_scanlines = 4;
        }

        if (apply_memory_bw_wa)
                wp->y_min_scanlines *= 2;

        wp->plane_bytes_per_line = wp->width * wp->cpp;
        if (wp->y_tiled) {
                interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line *
                                           wp->y_min_scanlines, 512);

                if (INTEL_GEN(dev_priv) >= 10)
                        interm_pbpl++;

                wp->plane_blocks_per_line = div_fixed16(interm_pbpl,
                                                        wp->y_min_scanlines);
        } else if (wp->x_tiled && IS_GEN9(dev_priv)) {
                interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line, 512);
                wp->plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
        } else {
                interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line, 512) + 1;
                wp->plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
        }

        wp->y_tile_minimum = mul_u32_fixed16(wp->y_min_scanlines,
                                             wp->plane_blocks_per_line);
        wp->linetime_us = fixed16_to_u32_round_up(
                                        intel_get_linetime_us(cstate));

        return 0;
}

static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
                                struct intel_crtc_state *cstate,
                                const struct intel_plane_state *intel_pstate,
                                uint16_t ddb_allocation,
                                int level,
                                const struct skl_wm_params *wp,
                                uint16_t *out_blocks, /* out */
                                uint8_t *out_lines, /* out */
                                bool *enabled /* out */)
{
        const struct drm_plane_state *pstate = &intel_pstate->base;
        uint32_t latency = dev_priv->wm.skl_latency[level];
        uint_fixed_16_16_t method1, method2;
        uint_fixed_16_16_t selected_result;
        uint32_t res_blocks, res_lines;
        struct intel_atomic_state *state =
                to_intel_atomic_state(cstate->base.state);
        bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state);

        if (latency == 0 ||
            !intel_wm_plane_visible(cstate, intel_pstate)) {
                *enabled = false;
                return 0;
        }

        /* Display WA #1141: kbl,cfl */
        if ((IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv) ||
            IS_CNL_REVID(dev_priv, CNL_REVID_A0, CNL_REVID_B0)) &&
            dev_priv->ipc_enabled)
                latency += 4;

        if (apply_memory_bw_wa && wp->x_tiled)
                latency += 15;

        method1 = skl_wm_method1(dev_priv, wp->plane_pixel_rate,
                                 wp->cpp, latency);
        method2 = skl_wm_method2(wp->plane_pixel_rate,
                                 cstate->base.adjusted_mode.crtc_htotal,
                                 latency,
                                 wp->plane_blocks_per_line);

        if (wp->y_tiled) {
                selected_result = max_fixed16(method2, wp->y_tile_minimum);
        } else {
                if ((wp->cpp * cstate->base.adjusted_mode.crtc_htotal /
                     512 < 1) && (wp->plane_bytes_per_line / 512 < 1))
                        selected_result = method2;
                else if (ddb_allocation >=
                         fixed16_to_u32_round_up(wp->plane_blocks_per_line))
                        selected_result = min_fixed16(method1, method2);
                else if (latency >= wp->linetime_us)
                        selected_result = min_fixed16(method1, method2);
                else
                        selected_result = method1;
        }

        res_blocks = fixed16_to_u32_round_up(selected_result) + 1;
        res_lines = div_round_up_fixed16(selected_result,
                                         wp->plane_blocks_per_line);

        /* Display WA #1125: skl,bxt,kbl,glk */
        if (level == 0 && wp->rc_surface)
                res_blocks += fixed16_to_u32_round_up(wp->y_tile_minimum);

        /* Display WA #1126: skl,bxt,kbl,glk */
        if (level >= 1 && level <= 7) {
                if (wp->y_tiled) {
                        res_blocks += fixed16_to_u32_round_up(
                                                        wp->y_tile_minimum);
                        res_lines += wp->y_min_scanlines;
                } else {
                        res_blocks++;
                }
        }

        if (res_blocks >= ddb_allocation || res_lines > 31) {
                *enabled = false;

                /*
                 * If there are no valid level 0 watermarks, then we can't
                 * support this display configuration.
                 */
                if (level) {
                        return 0;
                } else {
                        struct drm_plane *plane = pstate->plane;

                        DRM_DEBUG_KMS("Requested display configuration exceeds system watermark limitations\n");
                        DRM_DEBUG_KMS("[PLANE:%d:%s] blocks required = %u/%u, lines required = %u/31\n",
                                      plane->base.id, plane->name,
                                      res_blocks, ddb_allocation, res_lines);
                        return -EINVAL;
                }
        }

        *out_blocks = res_blocks;
        *out_lines = res_lines;
        *enabled = true;

        return 0;
}

static int
skl_compute_wm_levels(const struct drm_i915_private *dev_priv,
                      struct skl_ddb_allocation *ddb,
                      struct intel_crtc_state *cstate,
                      const struct intel_plane_state *intel_pstate,
                      const struct skl_wm_params *wm_params,
                      struct skl_plane_wm *wm)
{
        struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
        struct drm_plane *plane = intel_pstate->base.plane;
        struct intel_plane *intel_plane = to_intel_plane(plane);
        uint16_t ddb_blocks;
        enum pipe pipe = intel_crtc->pipe;
        int level, max_level = ilk_wm_max_level(dev_priv);
        int ret;

        if (WARN_ON(!intel_pstate->base.fb))
                return -EINVAL;

        ddb_blocks = skl_ddb_entry_size(&ddb->plane[pipe][intel_plane->id]);

        for (level = 0; level <= max_level; level++) {
                struct skl_wm_level *result = &wm->wm[level];

                ret = skl_compute_plane_wm(dev_priv,
                                           cstate,
                                           intel_pstate,
                                           ddb_blocks,
                                           level,
                                           wm_params,
                                           &result->plane_res_b,
                                           &result->plane_res_l,
                                           &result->plane_en);
                if (ret)
                        return ret;
        }

        return 0;
}

static uint32_t
skl_compute_linetime_wm(struct intel_crtc_state *cstate)
{
        struct drm_atomic_state *state = cstate->base.state;
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        uint_fixed_16_16_t linetime_us;
        uint32_t linetime_wm;

        linetime_us = intel_get_linetime_us(cstate);

        if (is_fixed16_zero(linetime_us))
                return 0;

        linetime_wm = fixed16_to_u32_round_up(mul_u32_fixed16(8, linetime_us));

        /* Display WA #1135: bxt:ALL GLK:ALL */
        if ((IS_BROXTON(dev_priv) || IS_GEMINILAKE(dev_priv)) &&
            dev_priv->ipc_enabled)
                linetime_wm /= 2;

        return linetime_wm;
}

static void skl_compute_transition_wm(struct intel_crtc_state *cstate,
                                      struct skl_wm_params *wp,
                                      struct skl_wm_level *wm_l0,
                                      uint16_t ddb_allocation,
                                      struct skl_wm_level *trans_wm /* out */)
{
        struct drm_device *dev = cstate->base.crtc->dev;
        const struct drm_i915_private *dev_priv = to_i915(dev);
        uint16_t trans_min, trans_y_tile_min;
        const uint16_t trans_amount = 10; /* This is configurable amount */
        uint16_t trans_offset_b, res_blocks;

        if (!cstate->base.active)
                goto exit;

        /* Transition WM are not recommended by HW team for GEN9 */
        if (INTEL_GEN(dev_priv) <= 9)
                goto exit;

        /* Transition WM don't make any sense if ipc is disabled */
        if (!dev_priv->ipc_enabled)
                goto exit;

        if (INTEL_GEN(dev_priv) >= 10)
                trans_min = 4;

        trans_offset_b = trans_min + trans_amount;

        if (wp->y_tiled) {
                trans_y_tile_min = (uint16_t) mul_round_up_u32_fixed16(2,
                                                        wp->y_tile_minimum);
                res_blocks = max(wm_l0->plane_res_b, trans_y_tile_min) +
                                trans_offset_b;
        } else {
                res_blocks = wm_l0->plane_res_b + trans_offset_b;

                /* WA BUG:1938466 add one block for non y-tile planes */
                if (IS_CNL_REVID(dev_priv, CNL_REVID_A0, CNL_REVID_A0))
                        res_blocks += 1;

        }

        res_blocks += 1;

        if (res_blocks < ddb_allocation) {
                trans_wm->plane_res_b = res_blocks;
                trans_wm->plane_en = true;
                return;
        }

exit:
        trans_wm->plane_en = false;
}

static int skl_build_pipe_wm(struct intel_crtc_state *cstate,
                             struct skl_ddb_allocation *ddb,
                             struct skl_pipe_wm *pipe_wm)
{
        struct drm_device *dev = cstate->base.crtc->dev;
        struct drm_crtc_state *crtc_state = &cstate->base;
        const struct drm_i915_private *dev_priv = to_i915(dev);
        struct drm_plane *plane;
        const struct drm_plane_state *pstate;
        struct skl_plane_wm *wm;
        int ret;

        /*
         * We'll only calculate watermarks for planes that are actually
         * enabled, so make sure all other planes are set as disabled.
         */
        memset(pipe_wm->planes, 0, sizeof(pipe_wm->planes));

        drm_atomic_crtc_state_for_each_plane_state(plane, pstate, crtc_state) {
                const struct intel_plane_state *intel_pstate =
                                                to_intel_plane_state(pstate);
                enum plane_id plane_id = to_intel_plane(plane)->id;
                struct skl_wm_params wm_params;
                enum pipe pipe = to_intel_crtc(cstate->base.crtc)->pipe;
                uint16_t ddb_blocks;

                wm = &pipe_wm->planes[plane_id];
                ddb_blocks = skl_ddb_entry_size(&ddb->plane[pipe][plane_id]);
                memset(&wm_params, 0, sizeof(struct skl_wm_params));

                ret = skl_compute_plane_wm_params(dev_priv, cstate,
                                                  intel_pstate, &wm_params);
                if (ret)
                        return ret;

                ret = skl_compute_wm_levels(dev_priv, ddb, cstate,
                                            intel_pstate, &wm_params, wm);
                if (ret)
                        return ret;
                skl_compute_transition_wm(cstate, &wm_params, &wm->wm[0],
                                          ddb_blocks, &wm->trans_wm);
        }
        pipe_wm->linetime = skl_compute_linetime_wm(cstate);

        return 0;
}

static void skl_ddb_entry_write(struct drm_i915_private *dev_priv,
                                i915_reg_t reg,
                                const struct skl_ddb_entry *entry)
{
        if (entry->end)
                I915_WRITE(reg, (entry->end - 1) << 16 | entry->start);
        else
                I915_WRITE(reg, 0);
}

static void skl_write_wm_level(struct drm_i915_private *dev_priv,
                               i915_reg_t reg,
                               const struct skl_wm_level *level)
{
        uint32_t val = 0;

        if (level->plane_en) {
                val |= PLANE_WM_EN;
                val |= level->plane_res_b;
                val |= level->plane_res_l << PLANE_WM_LINES_SHIFT;
        }

        I915_WRITE(reg, val);
}

static void skl_write_plane_wm(struct intel_crtc *intel_crtc,
                               const struct skl_plane_wm *wm,
                               const struct skl_ddb_allocation *ddb,
                               enum plane_id plane_id)
{
        struct drm_crtc *crtc = &intel_crtc->base;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        int level, max_level = ilk_wm_max_level(dev_priv);
        enum pipe pipe = intel_crtc->pipe;

        for (level = 0; level <= max_level; level++) {
                skl_write_wm_level(dev_priv, PLANE_WM(pipe, plane_id, level),
                                   &wm->wm[level]);
        }
        skl_write_wm_level(dev_priv, PLANE_WM_TRANS(pipe, plane_id),
                           &wm->trans_wm);

        skl_ddb_entry_write(dev_priv, PLANE_BUF_CFG(pipe, plane_id),
                            &ddb->plane[pipe][plane_id]);
        skl_ddb_entry_write(dev_priv, PLANE_NV12_BUF_CFG(pipe, plane_id),
                            &ddb->y_plane[pipe][plane_id]);
}

static void skl_write_cursor_wm(struct intel_crtc *intel_crtc,
                                const struct skl_plane_wm *wm,
                                const struct skl_ddb_allocation *ddb)
{
        struct drm_crtc *crtc = &intel_crtc->base;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        int level, max_level = ilk_wm_max_level(dev_priv);
        enum pipe pipe = intel_crtc->pipe;

        for (level = 0; level <= max_level; level++) {
                skl_write_wm_level(dev_priv, CUR_WM(pipe, level),
                                   &wm->wm[level]);
        }
        skl_write_wm_level(dev_priv, CUR_WM_TRANS(pipe), &wm->trans_wm);

        skl_ddb_entry_write(dev_priv, CUR_BUF_CFG(pipe),
                            &ddb->plane[pipe][PLANE_CURSOR]);
}

bool skl_wm_level_equals(const struct skl_wm_level *l1,
                         const struct skl_wm_level *l2)
{
        if (l1->plane_en != l2->plane_en)
                return false;

        /* If both planes aren't enabled, the rest shouldn't matter */
        if (!l1->plane_en)
                return true;

        return (l1->plane_res_l == l2->plane_res_l &&
                l1->plane_res_b == l2->plane_res_b);
}

static inline bool skl_ddb_entries_overlap(const struct skl_ddb_entry *a,
                                           const struct skl_ddb_entry *b)
{
        return a->start < b->end && b->start < a->end;
}

bool skl_ddb_allocation_overlaps(const struct skl_ddb_entry **entries,
                                 const struct skl_ddb_entry *ddb,
                                 int ignore)
{
        int i;

        for (i = 0; i < I915_MAX_PIPES; i++)
                if (i != ignore && entries[i] &&
                    skl_ddb_entries_overlap(ddb, entries[i]))
                        return true;

        return false;
}

static int skl_update_pipe_wm(struct drm_crtc_state *cstate,
                              const struct skl_pipe_wm *old_pipe_wm,
                              struct skl_pipe_wm *pipe_wm, /* out */
                              struct skl_ddb_allocation *ddb, /* out */
                              bool *changed /* out */)
{
        struct intel_crtc_state *intel_cstate = to_intel_crtc_state(cstate);
        int ret;

        ret = skl_build_pipe_wm(intel_cstate, ddb, pipe_wm);
        if (ret)
                return ret;

        if (!memcmp(old_pipe_wm, pipe_wm, sizeof(*pipe_wm)))
                *changed = false;
        else
                *changed = true;

        return 0;
}

static uint32_t
pipes_modified(struct drm_atomic_state *state)
{
        struct drm_crtc *crtc;
        struct drm_crtc_state *cstate;
        uint32_t i, ret = 0;

        for_each_new_crtc_in_state(state, crtc, cstate, i)
                ret |= drm_crtc_mask(crtc);

        return ret;
}

static int
skl_ddb_add_affected_planes(struct intel_crtc_state *cstate)
{
        struct drm_atomic_state *state = cstate->base.state;
        struct drm_device *dev = state->dev;
        struct drm_crtc *crtc = cstate->base.crtc;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb;
        struct skl_ddb_allocation *cur_ddb = &dev_priv->wm.skl_hw.ddb;
        struct drm_plane_state *plane_state;
        struct drm_plane *plane;
        enum pipe pipe = intel_crtc->pipe;

        WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));

        drm_for_each_plane_mask(plane, dev, cstate->base.plane_mask) {
                enum plane_id plane_id = to_intel_plane(plane)->id;

                if (skl_ddb_entry_equal(&cur_ddb->plane[pipe][plane_id],
                                        &new_ddb->plane[pipe][plane_id]) &&
                    skl_ddb_entry_equal(&cur_ddb->y_plane[pipe][plane_id],
                                        &new_ddb->y_plane[pipe][plane_id]))
                        continue;

                plane_state = drm_atomic_get_plane_state(state, plane);
                if (IS_ERR(plane_state))
                        return PTR_ERR(plane_state);
        }

        return 0;
}

static int
skl_compute_ddb(struct drm_atomic_state *state)
{
        struct drm_device *dev = state->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct intel_crtc *intel_crtc;
        struct skl_ddb_allocation *ddb = &intel_state->wm_results.ddb;
        uint32_t realloc_pipes = pipes_modified(state);
        int ret;

        /*
         * If this is our first atomic update following hardware readout,
         * we can't trust the DDB that the BIOS programmed for us.  Let's
         * pretend that all pipes switched active status so that we'll
         * ensure a full DDB recompute.
         */
        if (dev_priv->wm.distrust_bios_wm) {
                ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
                                       state->acquire_ctx);
                if (ret)
                        return ret;

                intel_state->active_pipe_changes = ~0;

                /*
                 * We usually only initialize intel_state->active_crtcs if we
                 * we're doing a modeset; make sure this field is always
                 * initialized during the sanitization process that happens
                 * on the first commit too.
                 */
                if (!intel_state->modeset)
                        intel_state->active_crtcs = dev_priv->active_crtcs;
        }

        /*
         * If the modeset changes which CRTC's are active, we need to
         * recompute the DDB allocation for *all* active pipes, even
         * those that weren't otherwise being modified in any way by this
         * atomic commit.  Due to the shrinking of the per-pipe allocations
         * when new active CRTC's are added, it's possible for a pipe that
         * we were already using and aren't changing at all here to suddenly
         * become invalid if its DDB needs exceeds its new allocation.
         *
         * Note that if we wind up doing a full DDB recompute, we can't let
         * any other display updates race with this transaction, so we need
         * to grab the lock on *all* CRTC's.
         */
        if (intel_state->active_pipe_changes) {
                realloc_pipes = ~0;
                intel_state->wm_results.dirty_pipes = ~0;
        }

        /*
         * We're not recomputing for the pipes not included in the commit, so
         * make sure we start with the current state.
         */
        memcpy(ddb, &dev_priv->wm.skl_hw.ddb, sizeof(*ddb));

        for_each_intel_crtc_mask(dev, intel_crtc, realloc_pipes) {
                struct intel_crtc_state *cstate;

                cstate = intel_atomic_get_crtc_state(state, intel_crtc);
                if (IS_ERR(cstate))
                        return PTR_ERR(cstate);

                ret = skl_allocate_pipe_ddb(cstate, ddb);
                if (ret)
                        return ret;

                ret = skl_ddb_add_affected_planes(cstate);
                if (ret)
                        return ret;
        }

        return 0;
}

static void
skl_copy_wm_for_pipe(struct skl_wm_values *dst,
                     struct skl_wm_values *src,
                     enum pipe pipe)
{
        memcpy(dst->ddb.y_plane[pipe], src->ddb.y_plane[pipe],
               sizeof(dst->ddb.y_plane[pipe]));
        memcpy(dst->ddb.plane[pipe], src->ddb.plane[pipe],
               sizeof(dst->ddb.plane[pipe]));
}

static void
skl_print_wm_changes(const struct drm_atomic_state *state)
{
        const struct drm_device *dev = state->dev;
        const struct drm_i915_private *dev_priv = to_i915(dev);
        const struct intel_atomic_state *intel_state =
                to_intel_atomic_state(state);
        const struct drm_crtc *crtc;
        const struct drm_crtc_state *cstate;
        const struct intel_plane *intel_plane;
        const struct skl_ddb_allocation *old_ddb = &dev_priv->wm.skl_hw.ddb;
        const struct skl_ddb_allocation *new_ddb = &intel_state->wm_results.ddb;
        int i;

        for_each_new_crtc_in_state(state, crtc, cstate, i) {
                const struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
                enum pipe pipe = intel_crtc->pipe;

                for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
                        enum plane_id plane_id = intel_plane->id;
                        const struct skl_ddb_entry *old, *new;

                        old = &old_ddb->plane[pipe][plane_id];
                        new = &new_ddb->plane[pipe][plane_id];

                        if (skl_ddb_entry_equal(old, new))
                                continue;

                        DRM_DEBUG_ATOMIC("[PLANE:%d:%s] ddb (%d - %d) -> (%d - %d)\n",
                                         intel_plane->base.base.id,
                                         intel_plane->base.name,
                                         old->start, old->end,
                                         new->start, new->end);
                }
        }
}

static int
skl_compute_wm(struct drm_atomic_state *state)
{
        struct drm_crtc *crtc;
        struct drm_crtc_state *cstate;
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct skl_wm_values *results = &intel_state->wm_results;
        struct drm_device *dev = state->dev;
        struct skl_pipe_wm *pipe_wm;
        bool changed = false;
        int ret, i;

        /*
         * When we distrust bios wm we always need to recompute to set the
         * expected DDB allocations for each CRTC.
         */
        if (to_i915(dev)->wm.distrust_bios_wm)
                changed = true;

        /*
         * If this transaction isn't actually touching any CRTC's, don't
         * bother with watermark calculation.  Note that if we pass this
         * test, we're guaranteed to hold at least one CRTC state mutex,
         * which means we can safely use values like dev_priv->active_crtcs
         * since any racing commits that want to update them would need to
         * hold _all_ CRTC state mutexes.
         */
        for_each_new_crtc_in_state(state, crtc, cstate, i)
                changed = true;

        if (!changed)
                return 0;

        /* Clear all dirty flags */
        results->dirty_pipes = 0;

        ret = skl_compute_ddb(state);
        if (ret)
                return ret;

        /*
         * Calculate WM's for all pipes that are part of this transaction.
         * Note that the DDB allocation above may have added more CRTC's that
         * weren't otherwise being modified (and set bits in dirty_pipes) if
         * pipe allocations had to change.
         *
         * FIXME:  Now that we're doing this in the atomic check phase, we
         * should allow skl_update_pipe_wm() to return failure in cases where
         * no suitable watermark values can be found.
         */
        for_each_new_crtc_in_state(state, crtc, cstate, i) {
                struct intel_crtc_state *intel_cstate =
                        to_intel_crtc_state(cstate);
                const struct skl_pipe_wm *old_pipe_wm =
                        &to_intel_crtc_state(crtc->state)->wm.skl.optimal;

                pipe_wm = &intel_cstate->wm.skl.optimal;
                ret = skl_update_pipe_wm(cstate, old_pipe_wm, pipe_wm,
                                         &results->ddb, &changed);
                if (ret)
                        return ret;

                if (changed)
                        results->dirty_pipes |= drm_crtc_mask(crtc);

                if ((results->dirty_pipes & drm_crtc_mask(crtc)) == 0)
                        /* This pipe's WM's did not change */
                        continue;

                intel_cstate->update_wm_pre = true;
        }

        skl_print_wm_changes(state);

        return 0;
}

static void skl_atomic_update_crtc_wm(struct intel_atomic_state *state,
                                      struct intel_crtc_state *cstate)
{
        struct intel_crtc *crtc = to_intel_crtc(cstate->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        struct skl_pipe_wm *pipe_wm = &cstate->wm.skl.optimal;
        const struct skl_ddb_allocation *ddb = &state->wm_results.ddb;
        enum pipe pipe = crtc->pipe;
        enum plane_id plane_id;

        if (!(state->wm_results.dirty_pipes & drm_crtc_mask(&crtc->base)))
                return;

        I915_WRITE(PIPE_WM_LINETIME(pipe), pipe_wm->linetime);

        for_each_plane_id_on_crtc(crtc, plane_id) {
                if (plane_id != PLANE_CURSOR)
                        skl_write_plane_wm(crtc, &pipe_wm->planes[plane_id],
                                           ddb, plane_id);
                else
                        skl_write_cursor_wm(crtc, &pipe_wm->planes[plane_id],
                                            ddb);
        }
}

static void skl_initial_wm(struct intel_atomic_state *state,
                           struct intel_crtc_state *cstate)
{
        struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
        struct drm_device *dev = intel_crtc->base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct skl_wm_values *results = &state->wm_results;
        struct skl_wm_values *hw_vals = &dev_priv->wm.skl_hw;
        enum pipe pipe = intel_crtc->pipe;

        if ((results->dirty_pipes & drm_crtc_mask(&intel_crtc->base)) == 0)
                return;

        mutex_lock(&dev_priv->wm.wm_mutex);

        if (cstate->base.active_changed)
                skl_atomic_update_crtc_wm(state, cstate);

        skl_copy_wm_for_pipe(hw_vals, results, pipe);

        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static void ilk_compute_wm_config(struct drm_device *dev,
                                  struct intel_wm_config *config)
{
        struct intel_crtc *crtc;

        /* Compute the currently _active_ config */
        for_each_intel_crtc(dev, crtc) {
                const struct intel_pipe_wm *wm = &crtc->wm.active.ilk;

                if (!wm->pipe_enabled)
                        continue;

                config->sprites_enabled |= wm->sprites_enabled;
                config->sprites_scaled |= wm->sprites_scaled;
                config->num_pipes_active++;
        }
}

static void ilk_program_watermarks(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = &dev_priv->drm;
        struct intel_pipe_wm lp_wm_1_2 = {}, lp_wm_5_6 = {}, *best_lp_wm;
        struct ilk_wm_maximums max;
        struct intel_wm_config config = {};
        struct ilk_wm_values results = {};
        enum intel_ddb_partitioning partitioning;

        ilk_compute_wm_config(dev, &config);

        ilk_compute_wm_maximums(dev, 1, &config, INTEL_DDB_PART_1_2, &max);
        ilk_wm_merge(dev, &config, &max, &lp_wm_1_2);

        /* 5/6 split only in single pipe config on IVB+ */
        if (INTEL_GEN(dev_priv) >= 7 &&
            config.num_pipes_active == 1 && config.sprites_enabled) {
                ilk_compute_wm_maximums(dev, 1, &config, INTEL_DDB_PART_5_6, &max);
                ilk_wm_merge(dev, &config, &max, &lp_wm_5_6);

                best_lp_wm = ilk_find_best_result(dev, &lp_wm_1_2, &lp_wm_5_6);
        } else {
                best_lp_wm = &lp_wm_1_2;
        }

        partitioning = (best_lp_wm == &lp_wm_1_2) ?
                       INTEL_DDB_PART_1_2 : INTEL_DDB_PART_5_6;

        ilk_compute_wm_results(dev, best_lp_wm, partitioning, &results);

        ilk_write_wm_values(dev_priv, &results);
}

static void ilk_initial_watermarks(struct intel_atomic_state *state,
                                   struct intel_crtc_state *cstate)
{
        struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);

        mutex_lock(&dev_priv->wm.wm_mutex);
        intel_crtc->wm.active.ilk = cstate->wm.ilk.intermediate;
        ilk_program_watermarks(dev_priv);
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static void ilk_optimize_watermarks(struct intel_atomic_state *state,
                                    struct intel_crtc_state *cstate)
{
        struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);

        mutex_lock(&dev_priv->wm.wm_mutex);
        if (cstate->wm.need_postvbl_update) {
                intel_crtc->wm.active.ilk = cstate->wm.ilk.optimal;
                ilk_program_watermarks(dev_priv);
        }
        mutex_unlock(&dev_priv->wm.wm_mutex);
}

static inline void skl_wm_level_from_reg_val(uint32_t val,
                                             struct skl_wm_level *level)
{
        level->plane_en = val & PLANE_WM_EN;
        level->plane_res_b = val & PLANE_WM_BLOCKS_MASK;
        level->plane_res_l = (val >> PLANE_WM_LINES_SHIFT) &
                PLANE_WM_LINES_MASK;
}

void skl_pipe_wm_get_hw_state(struct drm_crtc *crtc,
                              struct skl_pipe_wm *out)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        enum pipe pipe = intel_crtc->pipe;
        int level, max_level;
        enum plane_id plane_id;
        uint32_t val;

        max_level = ilk_wm_max_level(dev_priv);

        for_each_plane_id_on_crtc(intel_crtc, plane_id) {
                struct skl_plane_wm *wm = &out->planes[plane_id];

                for (level = 0; level <= max_level; level++) {
                        if (plane_id != PLANE_CURSOR)
                                val = I915_READ(PLANE_WM(pipe, plane_id, level));
                        else
                                val = I915_READ(CUR_WM(pipe, level));

                        skl_wm_level_from_reg_val(val, &wm->wm[level]);
                }

                if (plane_id != PLANE_CURSOR)
                        val = I915_READ(PLANE_WM_TRANS(pipe, plane_id));
                else
                        val = I915_READ(CUR_WM_TRANS(pipe));

                skl_wm_level_from_reg_val(val, &wm->trans_wm);
        }

        if (!intel_crtc->active)
                return;

        out->linetime = I915_READ(PIPE_WM_LINETIME(pipe));
}

void skl_wm_get_hw_state(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct skl_wm_values *hw = &dev_priv->wm.skl_hw;
        struct skl_ddb_allocation *ddb = &dev_priv->wm.skl_hw.ddb;
        struct drm_crtc *crtc;
        struct intel_crtc *intel_crtc;
        struct intel_crtc_state *cstate;

        skl_ddb_get_hw_state(dev_priv, ddb);
        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                intel_crtc = to_intel_crtc(crtc);
                cstate = to_intel_crtc_state(crtc->state);

                skl_pipe_wm_get_hw_state(crtc, &cstate->wm.skl.optimal);

                if (intel_crtc->active)
                        hw->dirty_pipes |= drm_crtc_mask(crtc);
        }

        if (dev_priv->active_crtcs) {
                /* Fully recompute DDB on first atomic commit */
                dev_priv->wm.distrust_bios_wm = true;
        } else {
                /* Easy/common case; just sanitize DDB now if everything off */
                memset(ddb, 0, sizeof(*ddb));
        }
}

static void ilk_pipe_wm_get_hw_state(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct ilk_wm_values *hw = &dev_priv->wm.hw;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
        struct intel_pipe_wm *active = &cstate->wm.ilk.optimal;
        enum pipe pipe = intel_crtc->pipe;
        static const i915_reg_t wm0_pipe_reg[] = {
                [PIPE_A] = WM0_PIPEA_ILK,
                [PIPE_B] = WM0_PIPEB_ILK,
                [PIPE_C] = WM0_PIPEC_IVB,
        };

        hw->wm_pipe[pipe] = I915_READ(wm0_pipe_reg[pipe]);
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                hw->wm_linetime[pipe] = I915_READ(PIPE_WM_LINETIME(pipe));

        memset(active, 0, sizeof(*active));

        active->pipe_enabled = intel_crtc->active;

        if (active->pipe_enabled) {
                u32 tmp = hw->wm_pipe[pipe];

                /*
                 * For active pipes LP0 watermark is marked as
                 * enabled, and LP1+ watermaks as disabled since
                 * we can't really reverse compute them in case
                 * multiple pipes are active.
                 */
                active->wm[0].enable = true;
                active->wm[0].pri_val = (tmp & WM0_PIPE_PLANE_MASK) >> WM0_PIPE_PLANE_SHIFT;
                active->wm[0].spr_val = (tmp & WM0_PIPE_SPRITE_MASK) >> WM0_PIPE_SPRITE_SHIFT;
                active->wm[0].cur_val = tmp & WM0_PIPE_CURSOR_MASK;
                active->linetime = hw->wm_linetime[pipe];
        } else {
                int level, max_level = ilk_wm_max_level(dev_priv);

                /*
                 * For inactive pipes, all watermark levels
                 * should be marked as enabled but zeroed,
                 * which is what we'd compute them to.
                 */
                for (level = 0; level <= max_level; level++)
                        active->wm[level].enable = true;
        }

        intel_crtc->wm.active.ilk = *active;
}

#define _FW_WM(value, plane) \
        (((value) & DSPFW_ ## plane ## _MASK) >> DSPFW_ ## plane ## _SHIFT)
#define _FW_WM_VLV(value, plane) \
        (((value) & DSPFW_ ## plane ## _MASK_VLV) >> DSPFW_ ## plane ## _SHIFT)

static void g4x_read_wm_values(struct drm_i915_private *dev_priv,
                               struct g4x_wm_values *wm)
{
        uint32_t tmp;

        tmp = I915_READ(DSPFW1);
        wm->sr.plane = _FW_WM(tmp, SR);
        wm->pipe[PIPE_B].plane[PLANE_CURSOR] = _FW_WM(tmp, CURSORB);
        wm->pipe[PIPE_B].plane[PLANE_PRIMARY] = _FW_WM(tmp, PLANEB);
        wm->pipe[PIPE_A].plane[PLANE_PRIMARY] = _FW_WM(tmp, PLANEA);

        tmp = I915_READ(DSPFW2);
        wm->fbc_en = tmp & DSPFW_FBC_SR_EN;
        wm->sr.fbc = _FW_WM(tmp, FBC_SR);
        wm->hpll.fbc = _FW_WM(tmp, FBC_HPLL_SR);
        wm->pipe[PIPE_B].plane[PLANE_SPRITE0] = _FW_WM(tmp, SPRITEB);
        wm->pipe[PIPE_A].plane[PLANE_CURSOR] = _FW_WM(tmp, CURSORA);
        wm->pipe[PIPE_A].plane[PLANE_SPRITE0] = _FW_WM(tmp, SPRITEA);

        tmp = I915_READ(DSPFW3);
        wm->hpll_en = tmp & DSPFW_HPLL_SR_EN;
        wm->sr.cursor = _FW_WM(tmp, CURSOR_SR);
        wm->hpll.cursor = _FW_WM(tmp, HPLL_CURSOR);
        wm->hpll.plane = _FW_WM(tmp, HPLL_SR);
}

static void vlv_read_wm_values(struct drm_i915_private *dev_priv,
                               struct vlv_wm_values *wm)
{
        enum pipe pipe;
        uint32_t tmp;

        for_each_pipe(dev_priv, pipe) {
                tmp = I915_READ(VLV_DDL(pipe));

                wm->ddl[pipe].plane[PLANE_PRIMARY] =
                        (tmp >> DDL_PLANE_SHIFT) & (DDL_PRECISION_HIGH | DRAIN_LATENCY_MASK);
                wm->ddl[pipe].plane[PLANE_CURSOR] =
                        (tmp >> DDL_CURSOR_SHIFT) & (DDL_PRECISION_HIGH | DRAIN_LATENCY_MASK);
                wm->ddl[pipe].plane[PLANE_SPRITE0] =
                        (tmp >> DDL_SPRITE_SHIFT(0)) & (DDL_PRECISION_HIGH | DRAIN_LATENCY_MASK);
                wm->ddl[pipe].plane[PLANE_SPRITE1] =
                        (tmp >> DDL_SPRITE_SHIFT(1)) & (DDL_PRECISION_HIGH | DRAIN_LATENCY_MASK);
        }

        tmp = I915_READ(DSPFW1);
        wm->sr.plane = _FW_WM(tmp, SR);
        wm->pipe[PIPE_B].plane[PLANE_CURSOR] = _FW_WM(tmp, CURSORB);
        wm->pipe[PIPE_B].plane[PLANE_PRIMARY] = _FW_WM_VLV(tmp, PLANEB);
        wm->pipe[PIPE_A].plane[PLANE_PRIMARY] = _FW_WM_VLV(tmp, PLANEA);

        tmp = I915_READ(DSPFW2);
        wm->pipe[PIPE_A].plane[PLANE_SPRITE1] = _FW_WM_VLV(tmp, SPRITEB);
        wm->pipe[PIPE_A].plane[PLANE_CURSOR] = _FW_WM(tmp, CURSORA);
        wm->pipe[PIPE_A].plane[PLANE_SPRITE0] = _FW_WM_VLV(tmp, SPRITEA);

        tmp = I915_READ(DSPFW3);
        wm->sr.cursor = _FW_WM(tmp, CURSOR_SR);

        if (IS_CHERRYVIEW(dev_priv)) {
                tmp = I915_READ(DSPFW7_CHV);
                wm->pipe[PIPE_B].plane[PLANE_SPRITE1] = _FW_WM_VLV(tmp, SPRITED);
                wm->pipe[PIPE_B].plane[PLANE_SPRITE0] = _FW_WM_VLV(tmp, SPRITEC);

                tmp = I915_READ(DSPFW8_CHV);
                wm->pipe[PIPE_C].plane[PLANE_SPRITE1] = _FW_WM_VLV(tmp, SPRITEF);
                wm->pipe[PIPE_C].plane[PLANE_SPRITE0] = _FW_WM_VLV(tmp, SPRITEE);

                tmp = I915_READ(DSPFW9_CHV);
                wm->pipe[PIPE_C].plane[PLANE_PRIMARY] = _FW_WM_VLV(tmp, PLANEC);
                wm->pipe[PIPE_C].plane[PLANE_CURSOR] = _FW_WM(tmp, CURSORC);

                tmp = I915_READ(DSPHOWM);
                wm->sr.plane |= _FW_WM(tmp, SR_HI) << 9;
                wm->pipe[PIPE_C].plane[PLANE_SPRITE1] |= _FW_WM(tmp, SPRITEF_HI) << 8;
                wm->pipe[PIPE_C].plane[PLANE_SPRITE0] |= _FW_WM(tmp, SPRITEE_HI) << 8;
                wm->pipe[PIPE_C].plane[PLANE_PRIMARY] |= _FW_WM(tmp, PLANEC_HI) << 8;
                wm->pipe[PIPE_B].plane[PLANE_SPRITE1] |= _FW_WM(tmp, SPRITED_HI) << 8;
                wm->pipe[PIPE_B].plane[PLANE_SPRITE0] |= _FW_WM(tmp, SPRITEC_HI) << 8;
                wm->pipe[PIPE_B].plane[PLANE_PRIMARY] |= _FW_WM(tmp, PLANEB_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_SPRITE1] |= _FW_WM(tmp, SPRITEB_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_SPRITE0] |= _FW_WM(tmp, SPRITEA_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_PRIMARY] |= _FW_WM(tmp, PLANEA_HI) << 8;
        } else {
                tmp = I915_READ(DSPFW7);
                wm->pipe[PIPE_B].plane[PLANE_SPRITE1] = _FW_WM_VLV(tmp, SPRITED);
                wm->pipe[PIPE_B].plane[PLANE_SPRITE0] = _FW_WM_VLV(tmp, SPRITEC);

                tmp = I915_READ(DSPHOWM);
                wm->sr.plane |= _FW_WM(tmp, SR_HI) << 9;
                wm->pipe[PIPE_B].plane[PLANE_SPRITE1] |= _FW_WM(tmp, SPRITED_HI) << 8;
                wm->pipe[PIPE_B].plane[PLANE_SPRITE0] |= _FW_WM(tmp, SPRITEC_HI) << 8;
                wm->pipe[PIPE_B].plane[PLANE_PRIMARY] |= _FW_WM(tmp, PLANEB_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_SPRITE1] |= _FW_WM(tmp, SPRITEB_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_SPRITE0] |= _FW_WM(tmp, SPRITEA_HI) << 8;
                wm->pipe[PIPE_A].plane[PLANE_PRIMARY] |= _FW_WM(tmp, PLANEA_HI) << 8;
        }
}

#undef _FW_WM
#undef _FW_WM_VLV

void g4x_wm_get_hw_state(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct g4x_wm_values *wm = &dev_priv->wm.g4x;
        struct intel_crtc *crtc;

        g4x_read_wm_values(dev_priv, wm);

        wm->cxsr = I915_READ(FW_BLC_SELF) & FW_BLC_SELF_EN;

        for_each_intel_crtc(dev, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct g4x_wm_state *active = &crtc->wm.active.g4x;
                struct g4x_pipe_wm *raw;
                enum pipe pipe = crtc->pipe;
                enum plane_id plane_id;
                int level, max_level;

                active->cxsr = wm->cxsr;
                active->hpll_en = wm->hpll_en;
                active->fbc_en = wm->fbc_en;

                active->sr = wm->sr;
                active->hpll = wm->hpll;

                for_each_plane_id_on_crtc(crtc, plane_id) {
                        active->wm.plane[plane_id] =
                                wm->pipe[pipe].plane[plane_id];
                }

                if (wm->cxsr && wm->hpll_en)
                        max_level = G4X_WM_LEVEL_HPLL;
                else if (wm->cxsr)
                        max_level = G4X_WM_LEVEL_SR;
                else
                        max_level = G4X_WM_LEVEL_NORMAL;

                level = G4X_WM_LEVEL_NORMAL;
                raw = &crtc_state->wm.g4x.raw[level];
                for_each_plane_id_on_crtc(crtc, plane_id)
                        raw->plane[plane_id] = active->wm.plane[plane_id];

                if (++level > max_level)
                        goto out;

                raw = &crtc_state->wm.g4x.raw[level];
                raw->plane[PLANE_PRIMARY] = active->sr.plane;
                raw->plane[PLANE_CURSOR] = active->sr.cursor;
                raw->plane[PLANE_SPRITE0] = 0;
                raw->fbc = active->sr.fbc;

                if (++level > max_level)
                        goto out;

                raw = &crtc_state->wm.g4x.raw[level];
                raw->plane[PLANE_PRIMARY] = active->hpll.plane;
                raw->plane[PLANE_CURSOR] = active->hpll.cursor;
                raw->plane[PLANE_SPRITE0] = 0;
                raw->fbc = active->hpll.fbc;

        out:
                for_each_plane_id_on_crtc(crtc, plane_id)
                        g4x_raw_plane_wm_set(crtc_state, level,
                                             plane_id, USHRT_MAX);
                g4x_raw_fbc_wm_set(crtc_state, level, USHRT_MAX);

                crtc_state->wm.g4x.optimal = *active;
                crtc_state->wm.g4x.intermediate = *active;

                DRM_DEBUG_KMS("Initial watermarks: pipe %c, plane=%d, cursor=%d, sprite=%d\n",
                              pipe_name(pipe),
                              wm->pipe[pipe].plane[PLANE_PRIMARY],
                              wm->pipe[pipe].plane[PLANE_CURSOR],
                              wm->pipe[pipe].plane[PLANE_SPRITE0]);
        }

        DRM_DEBUG_KMS("Initial SR watermarks: plane=%d, cursor=%d fbc=%d\n",
                      wm->sr.plane, wm->sr.cursor, wm->sr.fbc);
        DRM_DEBUG_KMS("Initial HPLL watermarks: plane=%d, SR cursor=%d fbc=%d\n",
                      wm->hpll.plane, wm->hpll.cursor, wm->hpll.fbc);
        DRM_DEBUG_KMS("Initial SR=%s HPLL=%s FBC=%s\n",
                      yesno(wm->cxsr), yesno(wm->hpll_en), yesno(wm->fbc_en));
}

void g4x_wm_sanitize(struct drm_i915_private *dev_priv)
{
        struct intel_plane *plane;
        struct intel_crtc *crtc;

        mutex_lock(&dev_priv->wm.wm_mutex);

        for_each_intel_plane(&dev_priv->drm, plane) {
                struct intel_crtc *crtc =
                        intel_get_crtc_for_pipe(dev_priv, plane->pipe);
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct intel_plane_state *plane_state =
                        to_intel_plane_state(plane->base.state);
                struct g4x_wm_state *wm_state = &crtc_state->wm.g4x.optimal;
                enum plane_id plane_id = plane->id;
                int level;

                if (plane_state->base.visible)
                        continue;

                for (level = 0; level < 3; level++) {
                        struct g4x_pipe_wm *raw =
                                &crtc_state->wm.g4x.raw[level];

                        raw->plane[plane_id] = 0;
                        wm_state->wm.plane[plane_id] = 0;
                }

                if (plane_id == PLANE_PRIMARY) {
                        for (level = 0; level < 3; level++) {
                                struct g4x_pipe_wm *raw =
                                        &crtc_state->wm.g4x.raw[level];
                                raw->fbc = 0;
                        }

                        wm_state->sr.fbc = 0;
                        wm_state->hpll.fbc = 0;
                        wm_state->fbc_en = false;
                }
        }

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);

                crtc_state->wm.g4x.intermediate =
                        crtc_state->wm.g4x.optimal;
                crtc->wm.active.g4x = crtc_state->wm.g4x.optimal;
        }

        g4x_program_watermarks(dev_priv);

        mutex_unlock(&dev_priv->wm.wm_mutex);
}

void vlv_wm_get_hw_state(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct vlv_wm_values *wm = &dev_priv->wm.vlv;
        struct intel_crtc *crtc;
        u32 val;

        vlv_read_wm_values(dev_priv, wm);

        wm->cxsr = I915_READ(FW_BLC_SELF_VLV) & FW_CSPWRDWNEN;
        wm->level = VLV_WM_LEVEL_PM2;

        if (IS_CHERRYVIEW(dev_priv)) {
                mutex_lock(&dev_priv->rps.hw_lock);

                val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
                if (val & DSP_MAXFIFO_PM5_ENABLE)
                        wm->level = VLV_WM_LEVEL_PM5;

                /*
                 * If DDR DVFS is disabled in the BIOS, Punit
                 * will never ack the request. So if that happens
                 * assume we don't have to enable/disable DDR DVFS
                 * dynamically. To test that just set the REQ_ACK
                 * bit to poke the Punit, but don't change the
                 * HIGH/LOW bits so that we don't actually change
                 * the current state.
                 */
                val = vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2);
                val |= FORCE_DDR_FREQ_REQ_ACK;
                vlv_punit_write(dev_priv, PUNIT_REG_DDR_SETUP2, val);

                if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2) &
                              FORCE_DDR_FREQ_REQ_ACK) == 0, 3)) {
                        DRM_DEBUG_KMS("Punit not acking DDR DVFS request, "
                                      "assuming DDR DVFS is disabled\n");
                        dev_priv->wm.max_level = VLV_WM_LEVEL_PM5;
                } else {
                        val = vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2);
                        if ((val & FORCE_DDR_HIGH_FREQ) == 0)
                                wm->level = VLV_WM_LEVEL_DDR_DVFS;
                }

                mutex_unlock(&dev_priv->rps.hw_lock);
        }

        for_each_intel_crtc(dev, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct vlv_wm_state *active = &crtc->wm.active.vlv;
                const struct vlv_fifo_state *fifo_state =
                        &crtc_state->wm.vlv.fifo_state;
                enum pipe pipe = crtc->pipe;
                enum plane_id plane_id;
                int level;

                vlv_get_fifo_size(crtc_state);

                active->num_levels = wm->level + 1;
                active->cxsr = wm->cxsr;

                for (level = 0; level < active->num_levels; level++) {
                        struct g4x_pipe_wm *raw =
                                &crtc_state->wm.vlv.raw[level];

                        active->sr[level].plane = wm->sr.plane;
                        active->sr[level].cursor = wm->sr.cursor;

                        for_each_plane_id_on_crtc(crtc, plane_id) {
                                active->wm[level].plane[plane_id] =
                                        wm->pipe[pipe].plane[plane_id];

                                raw->plane[plane_id] =
                                        vlv_invert_wm_value(active->wm[level].plane[plane_id],
                                                            fifo_state->plane[plane_id]);
                        }
                }

                for_each_plane_id_on_crtc(crtc, plane_id)
                        vlv_raw_plane_wm_set(crtc_state, level,
                                             plane_id, USHRT_MAX);
                vlv_invalidate_wms(crtc, active, level);

                crtc_state->wm.vlv.optimal = *active;
                crtc_state->wm.vlv.intermediate = *active;

                DRM_DEBUG_KMS("Initial watermarks: pipe %c, plane=%d, cursor=%d, sprite0=%d, sprite1=%d\n",
                              pipe_name(pipe),
                              wm->pipe[pipe].plane[PLANE_PRIMARY],
                              wm->pipe[pipe].plane[PLANE_CURSOR],
                              wm->pipe[pipe].plane[PLANE_SPRITE0],
                              wm->pipe[pipe].plane[PLANE_SPRITE1]);
        }

        DRM_DEBUG_KMS("Initial watermarks: SR plane=%d, SR cursor=%d level=%d cxsr=%d\n",
                      wm->sr.plane, wm->sr.cursor, wm->level, wm->cxsr);
}

void vlv_wm_sanitize(struct drm_i915_private *dev_priv)
{
        struct intel_plane *plane;
        struct intel_crtc *crtc;

        mutex_lock(&dev_priv->wm.wm_mutex);

        for_each_intel_plane(&dev_priv->drm, plane) {
                struct intel_crtc *crtc =
                        intel_get_crtc_for_pipe(dev_priv, plane->pipe);
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct intel_plane_state *plane_state =
                        to_intel_plane_state(plane->base.state);
                struct vlv_wm_state *wm_state = &crtc_state->wm.vlv.optimal;
                const struct vlv_fifo_state *fifo_state =
                        &crtc_state->wm.vlv.fifo_state;
                enum plane_id plane_id = plane->id;
                int level;

                if (plane_state->base.visible)
                        continue;

                for (level = 0; level < wm_state->num_levels; level++) {
                        struct g4x_pipe_wm *raw =
                                &crtc_state->wm.vlv.raw[level];

                        raw->plane[plane_id] = 0;

                        wm_state->wm[level].plane[plane_id] =
                                vlv_invert_wm_value(raw->plane[plane_id],
                                                    fifo_state->plane[plane_id]);
                }
        }

        for_each_intel_crtc(&dev_priv->drm, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);

                crtc_state->wm.vlv.intermediate =
                        crtc_state->wm.vlv.optimal;
                crtc->wm.active.vlv = crtc_state->wm.vlv.optimal;
        }

        vlv_program_watermarks(dev_priv);

        mutex_unlock(&dev_priv->wm.wm_mutex);
}

void ilk_wm_get_hw_state(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct ilk_wm_values *hw = &dev_priv->wm.hw;
        struct drm_crtc *crtc;

        for_each_crtc(dev, crtc)
                ilk_pipe_wm_get_hw_state(crtc);

        hw->wm_lp[0] = I915_READ(WM1_LP_ILK);
        hw->wm_lp[1] = I915_READ(WM2_LP_ILK);
        hw->wm_lp[2] = I915_READ(WM3_LP_ILK);

        hw->wm_lp_spr[0] = I915_READ(WM1S_LP_ILK);
        if (INTEL_GEN(dev_priv) >= 7) {
                hw->wm_lp_spr[1] = I915_READ(WM2S_LP_IVB);
                hw->wm_lp_spr[2] = I915_READ(WM3S_LP_IVB);
        }

        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                hw->partitioning = (I915_READ(WM_MISC) & WM_MISC_DATA_PARTITION_5_6) ?
                        INTEL_DDB_PART_5_6 : INTEL_DDB_PART_1_2;
        else if (IS_IVYBRIDGE(dev_priv))
                hw->partitioning = (I915_READ(DISP_ARB_CTL2) & DISP_DATA_PARTITION_5_6) ?
                        INTEL_DDB_PART_5_6 : INTEL_DDB_PART_1_2;

        hw->enable_fbc_wm =
                !(I915_READ(DISP_ARB_CTL) & DISP_FBC_WM_DIS);
}

/**
 * intel_update_watermarks - update FIFO watermark values based on current modes
 *
 * Calculate watermark values for the various WM regs based on current mode
 * and plane configuration.
 *
 * There are several cases to deal with here:
 *   - normal (i.e. non-self-refresh)
 *   - self-refresh (SR) mode
 *   - lines are large relative to FIFO size (buffer can hold up to 2)
 *   - lines are small relative to FIFO size (buffer can hold more than 2
 *     lines), so need to account for TLB latency
 *
 *   The normal calculation is:
 *     watermark = dotclock * bytes per pixel * latency
 *   where latency is platform & configuration dependent (we assume pessimal
 *   values here).
 *
 *   The SR calculation is:
 *     watermark = (trunc(latency/line time)+1) * surface width *
 *       bytes per pixel
 *   where
 *     line time = htotal / dotclock
 *     surface width = hdisplay for normal plane and 64 for cursor
 *   and latency is assumed to be high, as above.
 *
 * The final value programmed to the register should always be rounded up,
 * and include an extra 2 entries to account for clock crossings.
 *
 * We don't use the sprite, so we can ignore that.  And on Crestline we have
 * to set the non-SR watermarks to 8.
 */
void intel_update_watermarks(struct intel_crtc *crtc)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

        if (dev_priv->display.update_wm)
                dev_priv->display.update_wm(crtc);
}

void intel_enable_ipc(struct drm_i915_private *dev_priv)
{
        u32 val;

        /* Display WA #0477 WaDisableIPC: skl */
        if (IS_SKYLAKE(dev_priv)) {
                dev_priv->ipc_enabled = false;
                return;
        }

        val = I915_READ(DISP_ARB_CTL2);

        if (dev_priv->ipc_enabled)
                val |= DISP_IPC_ENABLE;
        else
                val &= ~DISP_IPC_ENABLE;

        I915_WRITE(DISP_ARB_CTL2, val);
}

void intel_init_ipc(struct drm_i915_private *dev_priv)
{
        dev_priv->ipc_enabled = false;
        if (!HAS_IPC(dev_priv))
                return;

        dev_priv->ipc_enabled = true;
        intel_enable_ipc(dev_priv);
}

/*
 * Lock protecting IPS related data structures
 */
DEFINE_SPINLOCK(mchdev_lock);

/* Global for IPS driver to get at the current i915 device. Protected by
 * mchdev_lock. */
static struct drm_i915_private *i915_mch_dev;

bool ironlake_set_drps(struct drm_i915_private *dev_priv, u8 val)
{
        u16 rgvswctl;

        lockdep_assert_held(&mchdev_lock);

        rgvswctl = I915_READ16(MEMSWCTL);
        if (rgvswctl & MEMCTL_CMD_STS) {
                DRM_DEBUG("gpu busy, RCS change rejected\n");
                return false; /* still busy with another command */
        }

        rgvswctl = (MEMCTL_CMD_CHFREQ << MEMCTL_CMD_SHIFT) |
                (val << MEMCTL_FREQ_SHIFT) | MEMCTL_SFCAVM;
        I915_WRITE16(MEMSWCTL, rgvswctl);
        POSTING_READ16(MEMSWCTL);

        rgvswctl |= MEMCTL_CMD_STS;
        I915_WRITE16(MEMSWCTL, rgvswctl);

        return true;
}

static void ironlake_enable_drps(struct drm_i915_private *dev_priv)
{
        u32 rgvmodectl;
        u8 fmax, fmin, fstart, vstart;

        spin_lock_irq(&mchdev_lock);

        rgvmodectl = I915_READ(MEMMODECTL);

        /* Enable temp reporting */
        I915_WRITE16(PMMISC, I915_READ(PMMISC) | MCPPCE_EN);
        I915_WRITE16(TSC1, I915_READ(TSC1) | TSE);

        /* 100ms RC evaluation intervals */
        I915_WRITE(RCUPEI, 100000);
        I915_WRITE(RCDNEI, 100000);

        /* Set max/min thresholds to 90ms and 80ms respectively */
        I915_WRITE(RCBMAXAVG, 90000);
        I915_WRITE(RCBMINAVG, 80000);

        I915_WRITE(MEMIHYST, 1);

        /* Set up min, max, and cur for interrupt handling */
        fmax = (rgvmodectl & MEMMODE_FMAX_MASK) >> MEMMODE_FMAX_SHIFT;
        fmin = (rgvmodectl & MEMMODE_FMIN_MASK);
        fstart = (rgvmodectl & MEMMODE_FSTART_MASK) >>
                MEMMODE_FSTART_SHIFT;

        vstart = (I915_READ(PXVFREQ(fstart)) & PXVFREQ_PX_MASK) >>
                PXVFREQ_PX_SHIFT;

        dev_priv->ips.fmax = fmax; /* IPS callback will increase this */
        dev_priv->ips.fstart = fstart;

        dev_priv->ips.max_delay = fstart;
        dev_priv->ips.min_delay = fmin;
        dev_priv->ips.cur_delay = fstart;

        DRM_DEBUG_DRIVER("fmax: %d, fmin: %d, fstart: %d\n",
                         fmax, fmin, fstart);

        I915_WRITE(MEMINTREN, MEMINT_CX_SUPR_EN | MEMINT_EVAL_CHG_EN);

        /*
         * Interrupts will be enabled in ironlake_irq_postinstall
         */

        I915_WRITE(VIDSTART, vstart);
        POSTING_READ(VIDSTART);

        rgvmodectl |= MEMMODE_SWMODE_EN;
        I915_WRITE(MEMMODECTL, rgvmodectl);

        if (wait_for_atomic((I915_READ(MEMSWCTL) & MEMCTL_CMD_STS) == 0, 10))
                DRM_ERROR("stuck trying to change perf mode\n");
        mdelay(1);

        ironlake_set_drps(dev_priv, fstart);

        dev_priv->ips.last_count1 = I915_READ(DMIEC) +
                I915_READ(DDREC) + I915_READ(CSIEC);
        dev_priv->ips.last_time1 = jiffies_to_msecs(jiffies);
        dev_priv->ips.last_count2 = I915_READ(GFXEC);
        dev_priv->ips.last_time2 = ktime_get_raw_ns();

        spin_unlock_irq(&mchdev_lock);
}

static void ironlake_disable_drps(struct drm_i915_private *dev_priv)
{
        u16 rgvswctl;

        spin_lock_irq(&mchdev_lock);

        rgvswctl = I915_READ16(MEMSWCTL);

        /* Ack interrupts, disable EFC interrupt */
        I915_WRITE(MEMINTREN, I915_READ(MEMINTREN) & ~MEMINT_EVAL_CHG_EN);
        I915_WRITE(MEMINTRSTS, MEMINT_EVAL_CHG);
        I915_WRITE(DEIER, I915_READ(DEIER) & ~DE_PCU_EVENT);
        I915_WRITE(DEIIR, DE_PCU_EVENT);
        I915_WRITE(DEIMR, I915_READ(DEIMR) | DE_PCU_EVENT);

        /* Go back to the starting frequency */
        ironlake_set_drps(dev_priv, dev_priv->ips.fstart);
        mdelay(1);
        rgvswctl |= MEMCTL_CMD_STS;
        I915_WRITE(MEMSWCTL, rgvswctl);
        mdelay(1);

        spin_unlock_irq(&mchdev_lock);
}

/* There's a funny hw issue where the hw returns all 0 when reading from
 * GEN6_RP_INTERRUPT_LIMITS. Hence we always need to compute the desired value
 * ourselves, instead of doing a rmw cycle (which might result in us clearing
 * all limits and the gpu stuck at whatever frequency it is at atm).
 */
static u32 intel_rps_limits(struct drm_i915_private *dev_priv, u8 val)
{
        u32 limits;

        /* Only set the down limit when we've reached the lowest level to avoid
         * getting more interrupts, otherwise leave this clear. This prevents a
         * race in the hw when coming out of rc6: There's a tiny window where
         * the hw runs at the minimal clock before selecting the desired
         * frequency, if the down threshold expires in that window we will not
         * receive a down interrupt. */
        if (INTEL_GEN(dev_priv) >= 9) {
                limits = (dev_priv->rps.max_freq_softlimit) << 23;
                if (val <= dev_priv->rps.min_freq_softlimit)
                        limits |= (dev_priv->rps.min_freq_softlimit) << 14;
        } else {
                limits = dev_priv->rps.max_freq_softlimit << 24;
                if (val <= dev_priv->rps.min_freq_softlimit)
                        limits |= dev_priv->rps.min_freq_softlimit << 16;
        }

        return limits;
}

static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
{
        int new_power;
        u32 threshold_up = 0, threshold_down = 0; /* in % */
        u32 ei_up = 0, ei_down = 0;

        new_power = dev_priv->rps.power;
        switch (dev_priv->rps.power) {
        case LOW_POWER:
                if (val > dev_priv->rps.efficient_freq + 1 &&
                    val > dev_priv->rps.cur_freq)
                        new_power = BETWEEN;
                break;

        case BETWEEN:
                if (val <= dev_priv->rps.efficient_freq &&
                    val < dev_priv->rps.cur_freq)
                        new_power = LOW_POWER;
                else if (val >= dev_priv->rps.rp0_freq &&
                         val > dev_priv->rps.cur_freq)
                        new_power = HIGH_POWER;
                break;

        case HIGH_POWER:
                if (val < (dev_priv->rps.rp1_freq + dev_priv->rps.rp0_freq) >> 1 &&
                    val < dev_priv->rps.cur_freq)
                        new_power = BETWEEN;
                break;
        }
        /* Max/min bins are special */
        if (val <= dev_priv->rps.min_freq_softlimit)
                new_power = LOW_POWER;
        if (val >= dev_priv->rps.max_freq_softlimit)
                new_power = HIGH_POWER;
        if (new_power == dev_priv->rps.power)
                return;

        /* Note the units here are not exactly 1us, but 1280ns. */
        switch (new_power) {
        case LOW_POWER:
                /* Upclock if more than 95% busy over 16ms */
                ei_up = 16000;
                threshold_up = 95;

                /* Downclock if less than 85% busy over 32ms */
                ei_down = 32000;
                threshold_down = 85;
                break;

        case BETWEEN:
                /* Upclock if more than 90% busy over 13ms */
                ei_up = 13000;
                threshold_up = 90;

                /* Downclock if less than 75% busy over 32ms */
                ei_down = 32000;
                threshold_down = 75;
                break;

        case HIGH_POWER:
                /* Upclock if more than 85% busy over 10ms */
                ei_up = 10000;
                threshold_up = 85;

                /* Downclock if less than 60% busy over 32ms */
                ei_down = 32000;
                threshold_down = 60;
                break;
        }

        /* When byt can survive without system hang with dynamic
         * sw freq adjustments, this restriction can be lifted.
         */
        if (IS_VALLEYVIEW(dev_priv))
                goto skip_hw_write;

        I915_WRITE(GEN6_RP_UP_EI,
                   GT_INTERVAL_FROM_US(dev_priv, ei_up));
        I915_WRITE(GEN6_RP_UP_THRESHOLD,
                   GT_INTERVAL_FROM_US(dev_priv,
                                       ei_up * threshold_up / 100));

        I915_WRITE(GEN6_RP_DOWN_EI,
                   GT_INTERVAL_FROM_US(dev_priv, ei_down));
        I915_WRITE(GEN6_RP_DOWN_THRESHOLD,
                   GT_INTERVAL_FROM_US(dev_priv,
                                       ei_down * threshold_down / 100));

        I915_WRITE(GEN6_RP_CONTROL,
                   GEN6_RP_MEDIA_TURBO |
                   GEN6_RP_MEDIA_HW_NORMAL_MODE |
                   GEN6_RP_MEDIA_IS_GFX |
                   GEN6_RP_ENABLE |
                   GEN6_RP_UP_BUSY_AVG |
                   GEN6_RP_DOWN_IDLE_AVG);

skip_hw_write:
        dev_priv->rps.power = new_power;
        dev_priv->rps.up_threshold = threshold_up;
        dev_priv->rps.down_threshold = threshold_down;
        dev_priv->rps.last_adj = 0;
}

static u32 gen6_rps_pm_mask(struct drm_i915_private *dev_priv, u8 val)
{
        u32 mask = 0;

        /* We use UP_EI_EXPIRED interupts for both up/down in manual mode */
        if (val > dev_priv->rps.min_freq_softlimit)
                mask |= GEN6_PM_RP_UP_EI_EXPIRED | GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT;
        if (val < dev_priv->rps.max_freq_softlimit)
                mask |= GEN6_PM_RP_UP_EI_EXPIRED | GEN6_PM_RP_UP_THRESHOLD;

        mask &= dev_priv->pm_rps_events;

        return gen6_sanitize_rps_pm_mask(dev_priv, ~mask);
}

/* gen6_set_rps is called to update the frequency request, but should also be
 * called when the range (min_delay and max_delay) is modified so that we can
 * update the GEN6_RP_INTERRUPT_LIMITS register accordingly. */
static int gen6_set_rps(struct drm_i915_private *dev_priv, u8 val)
{
        /* min/max delay may still have been modified so be sure to
         * write the limits value.
         */
        if (val != dev_priv->rps.cur_freq) {
                gen6_set_rps_thresholds(dev_priv, val);

                if (INTEL_GEN(dev_priv) >= 9)
                        I915_WRITE(GEN6_RPNSWREQ,
                                   GEN9_FREQUENCY(val));
                else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                        I915_WRITE(GEN6_RPNSWREQ,
                                   HSW_FREQUENCY(val));
                else
                        I915_WRITE(GEN6_RPNSWREQ,
                                   GEN6_FREQUENCY(val) |
                                   GEN6_OFFSET(0) |
                                   GEN6_AGGRESSIVE_TURBO);
        }

        /* Make sure we continue to get interrupts
         * until we hit the minimum or maximum frequencies.
         */
        I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, intel_rps_limits(dev_priv, val));
        I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));

        dev_priv->rps.cur_freq = val;
        trace_intel_gpu_freq_change(intel_gpu_freq(dev_priv, val));

        return 0;
}

static int valleyview_set_rps(struct drm_i915_private *dev_priv, u8 val)
{
        int err;

        if (WARN_ONCE(IS_CHERRYVIEW(dev_priv) && (val & 1),
                      "Odd GPU freq value\n"))
                val &= ~1;

        I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));

        if (val != dev_priv->rps.cur_freq) {
                err = vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
                if (err)
                        return err;

                gen6_set_rps_thresholds(dev_priv, val);
        }

        dev_priv->rps.cur_freq = val;
        trace_intel_gpu_freq_change(intel_gpu_freq(dev_priv, val));

        return 0;
}

/* vlv_set_rps_idle: Set the frequency to idle, if Gfx clocks are down
 *
 * * If Gfx is Idle, then
 * 1. Forcewake Media well.
 * 2. Request idle freq.
 * 3. Release Forcewake of Media well.
*/
static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
{
        u32 val = dev_priv->rps.idle_freq;
        int err;

        if (dev_priv->rps.cur_freq <= val)
                return;

        /* The punit delays the write of the frequency and voltage until it
         * determines the GPU is awake. During normal usage we don't want to
         * waste power changing the frequency if the GPU is sleeping (rc6).
         * However, the GPU and driver is now idle and we do not want to delay
         * switching to minimum voltage (reducing power whilst idle) as we do
         * not expect to be woken in the near future and so must flush the
         * change by waking the device.
         *
         * We choose to take the media powerwell (either would do to trick the
         * punit into committing the voltage change) as that takes a lot less
         * power than the render powerwell.
         */
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_MEDIA);
        err = valleyview_set_rps(dev_priv, val);
        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_MEDIA);

        if (err)
                DRM_ERROR("Failed to set RPS for idle\n");
}

void gen6_rps_busy(struct drm_i915_private *dev_priv)
{
        mutex_lock(&dev_priv->rps.hw_lock);
        if (dev_priv->rps.enabled) {
                u8 freq;

                if (dev_priv->pm_rps_events & GEN6_PM_RP_UP_EI_EXPIRED)
                        gen6_rps_reset_ei(dev_priv);
                I915_WRITE(GEN6_PMINTRMSK,
                           gen6_rps_pm_mask(dev_priv, dev_priv->rps.cur_freq));

                gen6_enable_rps_interrupts(dev_priv);

                /* Use the user's desired frequency as a guide, but for better
                 * performance, jump directly to RPe as our starting frequency.
                 */
                freq = max(dev_priv->rps.cur_freq,
                           dev_priv->rps.efficient_freq);

                if (intel_set_rps(dev_priv,
                                  clamp(freq,
                                        dev_priv->rps.min_freq_softlimit,
                                        dev_priv->rps.max_freq_softlimit)))
                        DRM_DEBUG_DRIVER("Failed to set idle frequency\n");
        }
        mutex_unlock(&dev_priv->rps.hw_lock);
}

void gen6_rps_idle(struct drm_i915_private *dev_priv)
{
        /* Flush our bottom-half so that it does not race with us
         * setting the idle frequency and so that it is bounded by
         * our rpm wakeref. And then disable the interrupts to stop any
         * futher RPS reclocking whilst we are asleep.
         */
        gen6_disable_rps_interrupts(dev_priv);

        mutex_lock(&dev_priv->rps.hw_lock);
        if (dev_priv->rps.enabled) {
                if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                        vlv_set_rps_idle(dev_priv);
                else
                        gen6_set_rps(dev_priv, dev_priv->rps.idle_freq);
                dev_priv->rps.last_adj = 0;
                I915_WRITE(GEN6_PMINTRMSK,
                           gen6_sanitize_rps_pm_mask(dev_priv, ~0));
        }
        mutex_unlock(&dev_priv->rps.hw_lock);
}

void gen6_rps_boost(struct drm_i915_gem_request *rq,
                    struct intel_rps_client *rps)
{
        struct drm_i915_private *i915 = rq->i915;
        unsigned long flags;
        bool boost;

        /* This is intentionally racy! We peek at the state here, then
         * validate inside the RPS worker.
         */
        if (!i915->rps.enabled)
                return;

        boost = false;
        spin_lock_irqsave(&rq->lock, flags);
        if (!rq->waitboost && !i915_gem_request_completed(rq)) {
                atomic_inc(&i915->rps.num_waiters);
                rq->waitboost = true;
                boost = true;
        }
        spin_unlock_irqrestore(&rq->lock, flags);
        if (!boost)
                return;

        if (READ_ONCE(i915->rps.cur_freq) < i915->rps.boost_freq)
                schedule_work(&i915->rps.work);

        atomic_inc(rps ? &rps->boosts : &i915->rps.boosts);
}

int intel_set_rps(struct drm_i915_private *dev_priv, u8 val)
{
        int err;

        lockdep_assert_held(&dev_priv->rps.hw_lock);
        GEM_BUG_ON(val > dev_priv->rps.max_freq);
        GEM_BUG_ON(val < dev_priv->rps.min_freq);

        if (!dev_priv->rps.enabled) {
                dev_priv->rps.cur_freq = val;
                return 0;
        }

        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                err = valleyview_set_rps(dev_priv, val);
        else
                err = gen6_set_rps(dev_priv, val);

        return err;
}

static void gen9_disable_rc6(struct drm_i915_private *dev_priv)
{
        I915_WRITE(GEN6_RC_CONTROL, 0);
        I915_WRITE(GEN9_PG_ENABLE, 0);
}

static void gen9_disable_rps(struct drm_i915_private *dev_priv)
{
        I915_WRITE(GEN6_RP_CONTROL, 0);
}

static void gen6_disable_rps(struct drm_i915_private *dev_priv)
{
        I915_WRITE(GEN6_RC_CONTROL, 0);
        I915_WRITE(GEN6_RPNSWREQ, 1 << 31);
        I915_WRITE(GEN6_RP_CONTROL, 0);
}

static void cherryview_disable_rps(struct drm_i915_private *dev_priv)
{
        I915_WRITE(GEN6_RC_CONTROL, 0);
}

static void valleyview_disable_rps(struct drm_i915_private *dev_priv)
{
        /* we're doing forcewake before Disabling RC6,
         * This what the BIOS expects when going into suspend */
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        I915_WRITE(GEN6_RC_CONTROL, 0);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void intel_print_rc6_info(struct drm_i915_private *dev_priv, u32 mode)
{
        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
                if (mode & (GEN7_RC_CTL_TO_MODE | GEN6_RC_CTL_EI_MODE(1)))
                        mode = GEN6_RC_CTL_RC6_ENABLE;
                else
                        mode = 0;
        }
        if (HAS_RC6p(dev_priv))
                DRM_DEBUG_DRIVER("Enabling RC6 states: "
                                 "RC6 %s RC6p %s RC6pp %s\n",
                                 onoff(mode & GEN6_RC_CTL_RC6_ENABLE),
                                 onoff(mode & GEN6_RC_CTL_RC6p_ENABLE),
                                 onoff(mode & GEN6_RC_CTL_RC6pp_ENABLE));

        else
                DRM_DEBUG_DRIVER("Enabling RC6 states: RC6 %s\n",
                                 onoff(mode & GEN6_RC_CTL_RC6_ENABLE));
}

static bool bxt_check_bios_rc6_setup(struct drm_i915_private *dev_priv)
{
        struct i915_ggtt *ggtt = &dev_priv->ggtt;
        bool enable_rc6 = true;
        unsigned long rc6_ctx_base;
        u32 rc_ctl;
        int rc_sw_target;

        rc_ctl = I915_READ(GEN6_RC_CONTROL);
        rc_sw_target = (I915_READ(GEN6_RC_STATE) & RC_SW_TARGET_STATE_MASK) >>
                       RC_SW_TARGET_STATE_SHIFT;
        DRM_DEBUG_DRIVER("BIOS enabled RC states: "
                         "HW_CTRL %s HW_RC6 %s SW_TARGET_STATE %x\n",
                         onoff(rc_ctl & GEN6_RC_CTL_HW_ENABLE),
                         onoff(rc_ctl & GEN6_RC_CTL_RC6_ENABLE),
                         rc_sw_target);

        if (!(I915_READ(RC6_LOCATION) & RC6_CTX_IN_DRAM)) {
                DRM_DEBUG_DRIVER("RC6 Base location not set properly.\n");
                enable_rc6 = false;
        }

        /*
         * The exact context size is not known for BXT, so assume a page size
         * for this check.
         */
        rc6_ctx_base = I915_READ(RC6_CTX_BASE) & RC6_CTX_BASE_MASK;
        if (!((rc6_ctx_base >= ggtt->stolen_reserved_base) &&
              (rc6_ctx_base + PAGE_SIZE <= ggtt->stolen_reserved_base +
                                        ggtt->stolen_reserved_size))) {
                DRM_DEBUG_DRIVER("RC6 Base address not as expected.\n");
                enable_rc6 = false;
        }

        if (!(((I915_READ(PWRCTX_MAXCNT_RCSUNIT) & IDLE_TIME_MASK) > 1) &&
              ((I915_READ(PWRCTX_MAXCNT_VCSUNIT0) & IDLE_TIME_MASK) > 1) &&
              ((I915_READ(PWRCTX_MAXCNT_BCSUNIT) & IDLE_TIME_MASK) > 1) &&
              ((I915_READ(PWRCTX_MAXCNT_VECSUNIT) & IDLE_TIME_MASK) > 1))) {
                DRM_DEBUG_DRIVER("Engine Idle wait time not set properly.\n");
                enable_rc6 = false;
        }

        if (!I915_READ(GEN8_PUSHBUS_CONTROL) ||
            !I915_READ(GEN8_PUSHBUS_ENABLE) ||
            !I915_READ(GEN8_PUSHBUS_SHIFT)) {
                DRM_DEBUG_DRIVER("Pushbus not setup properly.\n");
                enable_rc6 = false;
        }

        if (!I915_READ(GEN6_GFXPAUSE)) {
                DRM_DEBUG_DRIVER("GFX pause not setup properly.\n");
                enable_rc6 = false;
        }

        if (!I915_READ(GEN8_MISC_CTRL0)) {
                DRM_DEBUG_DRIVER("GPM control not setup properly.\n");
                enable_rc6 = false;
        }

        return enable_rc6;
}

int sanitize_rc6_option(struct drm_i915_private *dev_priv, int enable_rc6)
{
        /* No RC6 before Ironlake and code is gone for ilk. */
        if (INTEL_INFO(dev_priv)->gen < 6)
                return 0;

        if (!enable_rc6)
                return 0;

        if (IS_GEN9_LP(dev_priv) && !bxt_check_bios_rc6_setup(dev_priv)) {
                DRM_INFO("RC6 disabled by BIOS\n");
                return 0;
        }

        /* Respect the kernel parameter if it is set */
        if (enable_rc6 >= 0) {
                int mask;

                if (HAS_RC6p(dev_priv))
                        mask = INTEL_RC6_ENABLE | INTEL_RC6p_ENABLE |
                               INTEL_RC6pp_ENABLE;
                else
                        mask = INTEL_RC6_ENABLE;

                if ((enable_rc6 & mask) != enable_rc6)
                        DRM_DEBUG_DRIVER("Adjusting RC6 mask to %d "
                                         "(requested %d, valid %d)\n",
                                         enable_rc6 & mask, enable_rc6, mask);

                return enable_rc6 & mask;
        }

        if (IS_IVYBRIDGE(dev_priv))
                return (INTEL_RC6_ENABLE | INTEL_RC6p_ENABLE);

        return INTEL_RC6_ENABLE;
}

static void gen6_init_rps_frequencies(struct drm_i915_private *dev_priv)
{
        /* All of these values are in units of 50MHz */

        /* static values from HW: RP0 > RP1 > RPn (min_freq) */
        if (IS_GEN9_LP(dev_priv)) {
                u32 rp_state_cap = I915_READ(BXT_RP_STATE_CAP);
                dev_priv->rps.rp0_freq = (rp_state_cap >> 16) & 0xff;
                dev_priv->rps.rp1_freq = (rp_state_cap >>  8) & 0xff;
                dev_priv->rps.min_freq = (rp_state_cap >>  0) & 0xff;
        } else {
                u32 rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
                dev_priv->rps.rp0_freq = (rp_state_cap >>  0) & 0xff;
                dev_priv->rps.rp1_freq = (rp_state_cap >>  8) & 0xff;
                dev_priv->rps.min_freq = (rp_state_cap >> 16) & 0xff;
        }
        /* hw_max = RP0 until we check for overclocking */
        dev_priv->rps.max_freq = dev_priv->rps.rp0_freq;

        dev_priv->rps.efficient_freq = dev_priv->rps.rp1_freq;
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv) ||
            IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                u32 ddcc_status = 0;

                if (sandybridge_pcode_read(dev_priv,
                                           HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL,
                                           &ddcc_status) == 0)
                        dev_priv->rps.efficient_freq =
                                clamp_t(u8,
                                        ((ddcc_status >> 8) & 0xff),
                                        dev_priv->rps.min_freq,
                                        dev_priv->rps.max_freq);
        }

        if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                /* Store the frequency values in 16.66 MHZ units, which is
                 * the natural hardware unit for SKL
                 */
                dev_priv->rps.rp0_freq *= GEN9_FREQ_SCALER;
                dev_priv->rps.rp1_freq *= GEN9_FREQ_SCALER;
                dev_priv->rps.min_freq *= GEN9_FREQ_SCALER;
                dev_priv->rps.max_freq *= GEN9_FREQ_SCALER;
                dev_priv->rps.efficient_freq *= GEN9_FREQ_SCALER;
        }
}

static void reset_rps(struct drm_i915_private *dev_priv,
                      int (*set)(struct drm_i915_private *, u8))
{
        u8 freq = dev_priv->rps.cur_freq;

        /* force a reset */
        dev_priv->rps.power = -1;
        dev_priv->rps.cur_freq = -1;

        if (set(dev_priv, freq))
                DRM_ERROR("Failed to reset RPS to initial values\n");
}

/* See the Gen9_GT_PM_Programming_Guide doc for the below */
static void gen9_enable_rps(struct drm_i915_private *dev_priv)
{
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /* Program defaults and thresholds for RPS*/
        I915_WRITE(GEN6_RC_VIDEO_FREQ,
                GEN9_FREQUENCY(dev_priv->rps.rp1_freq));

        /* 1 second timeout*/
        I915_WRITE(GEN6_RP_DOWN_TIMEOUT,
                GT_INTERVAL_FROM_US(dev_priv, 1000000));

        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 0xa);

        /* Leaning on the below call to gen6_set_rps to program/setup the
         * Up/Down EI & threshold registers, as well as the RP_CONTROL,
         * RP_INTERRUPT_LIMITS & RPNSWREQ registers */
        reset_rps(dev_priv, gen6_set_rps);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void gen9_enable_rc6(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        uint32_t rc6_mask = 0;

        /* 1a: Software RC state - RC0 */
        I915_WRITE(GEN6_RC_STATE, 0);

        /* 1b: Get forcewake during program sequence. Although the driver
         * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /* 2a: Disable RC states. */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        /* 2b: Program RC6 thresholds.*/

        /* WaRsDoubleRc6WrlWithCoarsePowerGating: Doubling WRL only when CPG is enabled */
        if (IS_SKYLAKE(dev_priv))
                I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
        else
                I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
        for_each_engine(engine, dev_priv, id)
                I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);

        if (HAS_GUC(dev_priv))
                I915_WRITE(GUC_MAX_IDLE_COUNT, 0xA);

        I915_WRITE(GEN6_RC_SLEEP, 0);

        /* 2c: Program Coarse Power Gating Policies. */
        I915_WRITE(GEN9_MEDIA_PG_IDLE_HYSTERESIS, 25);
        I915_WRITE(GEN9_RENDER_PG_IDLE_HYSTERESIS, 25);

        /* 3a: Enable RC6 */
        if (intel_enable_rc6() & INTEL_RC6_ENABLE)
                rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
        DRM_INFO("RC6 %s\n", onoff(rc6_mask & GEN6_RC_CTL_RC6_ENABLE));
        I915_WRITE(GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */
        I915_WRITE(GEN6_RC_CONTROL,
                   GEN6_RC_CTL_HW_ENABLE | GEN6_RC_CTL_EI_MODE(1) | rc6_mask);

        /*
         * 3b: Enable Coarse Power Gating only when RC6 is enabled.
         * WaRsDisableCoarsePowerGating:skl,bxt - Render/Media PG need to be disabled with RC6.
         */
        if (NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
                I915_WRITE(GEN9_PG_ENABLE, 0);
        else
                I915_WRITE(GEN9_PG_ENABLE, (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?
                                (GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE) : 0);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void gen8_enable_rps(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        uint32_t rc6_mask = 0;

        /* 1a: Software RC state - RC0 */
        I915_WRITE(GEN6_RC_STATE, 0);

        /* 1c & 1d: Get forcewake during program sequence. Although the driver
         * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /* 2a: Disable RC states. */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        /* 2b: Program RC6 thresholds.*/
        I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
        for_each_engine(engine, dev_priv, id)
                I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
        I915_WRITE(GEN6_RC_SLEEP, 0);
        if (IS_BROADWELL(dev_priv))
                I915_WRITE(GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
        else
                I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */

        /* 3: Enable RC6 */
        if (intel_enable_rc6() & INTEL_RC6_ENABLE)
                rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
        intel_print_rc6_info(dev_priv, rc6_mask);
        if (IS_BROADWELL(dev_priv))
                I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
                                GEN7_RC_CTL_TO_MODE |
                                rc6_mask);
        else
                I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
                                GEN6_RC_CTL_EI_MODE(1) |
                                rc6_mask);

        /* 4 Program defaults and thresholds for RPS*/
        I915_WRITE(GEN6_RPNSWREQ,
                   HSW_FREQUENCY(dev_priv->rps.rp1_freq));
        I915_WRITE(GEN6_RC_VIDEO_FREQ,
                   HSW_FREQUENCY(dev_priv->rps.rp1_freq));
        /* NB: Docs say 1s, and 1000000 - which aren't equivalent */
        I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 100000000 / 128); /* 1 second timeout */

        /* Docs recommend 900MHz, and 300 MHz respectively */
        I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
                   dev_priv->rps.max_freq_softlimit << 24 |
                   dev_priv->rps.min_freq_softlimit << 16);

        I915_WRITE(GEN6_RP_UP_THRESHOLD, 7600000 / 128); /* 76ms busyness per EI, 90% */
        I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 31300000 / 128); /* 313ms busyness per EI, 70%*/
        I915_WRITE(GEN6_RP_UP_EI, 66000); /* 84.48ms, XXX: random? */
        I915_WRITE(GEN6_RP_DOWN_EI, 350000); /* 448ms, XXX: random? */

        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);

        /* 5: Enable RPS */
        I915_WRITE(GEN6_RP_CONTROL,
                   GEN6_RP_MEDIA_TURBO |
                   GEN6_RP_MEDIA_HW_NORMAL_MODE |
                   GEN6_RP_MEDIA_IS_GFX |
                   GEN6_RP_ENABLE |
                   GEN6_RP_UP_BUSY_AVG |
                   GEN6_RP_DOWN_IDLE_AVG);

        /* 6: Ring frequency + overclocking (our driver does this later */

        reset_rps(dev_priv, gen6_set_rps);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void gen6_enable_rps(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        u32 rc6vids, rc6_mask = 0;
        u32 gtfifodbg;
        int rc6_mode;
        int ret;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        /* Here begins a magic sequence of register writes to enable
         * auto-downclocking.
         *
         * Perhaps there might be some value in exposing these to
         * userspace...
         */
        I915_WRITE(GEN6_RC_STATE, 0);

        /* Clear the DBG now so we don't confuse earlier errors */
        gtfifodbg = I915_READ(GTFIFODBG);
        if (gtfifodbg) {
                DRM_ERROR("GT fifo had a previous error %x\n", gtfifodbg);
                I915_WRITE(GTFIFODBG, gtfifodbg);
        }

        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /* disable the counters and set deterministic thresholds */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        I915_WRITE(GEN6_RC1_WAKE_RATE_LIMIT, 1000 << 16);
        I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16 | 30);
        I915_WRITE(GEN6_RC6pp_WAKE_RATE_LIMIT, 30);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);

        for_each_engine(engine, dev_priv, id)
                I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);

        I915_WRITE(GEN6_RC_SLEEP, 0);
        I915_WRITE(GEN6_RC1e_THRESHOLD, 1000);
        if (IS_IVYBRIDGE(dev_priv))
                I915_WRITE(GEN6_RC6_THRESHOLD, 125000);
        else
                I915_WRITE(GEN6_RC6_THRESHOLD, 50000);
        I915_WRITE(GEN6_RC6p_THRESHOLD, 150000);
        I915_WRITE(GEN6_RC6pp_THRESHOLD, 64000); /* unused */

        /* Check if we are enabling RC6 */
        rc6_mode = intel_enable_rc6();
        if (rc6_mode & INTEL_RC6_ENABLE)
                rc6_mask |= GEN6_RC_CTL_RC6_ENABLE;

        /* We don't use those on Haswell */
        if (!IS_HASWELL(dev_priv)) {
                if (rc6_mode & INTEL_RC6p_ENABLE)
                        rc6_mask |= GEN6_RC_CTL_RC6p_ENABLE;

                if (rc6_mode & INTEL_RC6pp_ENABLE)
                        rc6_mask |= GEN6_RC_CTL_RC6pp_ENABLE;
        }

        intel_print_rc6_info(dev_priv, rc6_mask);

        I915_WRITE(GEN6_RC_CONTROL,
                   rc6_mask |
                   GEN6_RC_CTL_EI_MODE(1) |
                   GEN6_RC_CTL_HW_ENABLE);

        /* Power down if completely idle for over 50ms */
        I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 50000);
        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);

        reset_rps(dev_priv, gen6_set_rps);

        rc6vids = 0;
        ret = sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
        if (IS_GEN6(dev_priv) && ret) {
                DRM_DEBUG_DRIVER("Couldn't check for BIOS workaround\n");
        } else if (IS_GEN6(dev_priv) && (GEN6_DECODE_RC6_VID(rc6vids & 0xff) < 450)) {
                DRM_DEBUG_DRIVER("You should update your BIOS. Correcting minimum rc6 voltage (%dmV->%dmV)\n",
                          GEN6_DECODE_RC6_VID(rc6vids & 0xff), 450);
                rc6vids &= 0xffff00;
                rc6vids |= GEN6_ENCODE_RC6_VID(450);
                ret = sandybridge_pcode_write(dev_priv, GEN6_PCODE_WRITE_RC6VIDS, rc6vids);
                if (ret)
                        DRM_ERROR("Couldn't fix incorrect rc6 voltage\n");
        }

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void gen6_update_ring_freq(struct drm_i915_private *dev_priv)
{
        int min_freq = 15;
        unsigned int gpu_freq;
        unsigned int max_ia_freq, min_ring_freq;
        unsigned int max_gpu_freq, min_gpu_freq;
        int scaling_factor = 180;
        struct cpufreq_policy *policy;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        policy = cpufreq_cpu_get(0);
        if (policy) {
                max_ia_freq = policy->cpuinfo.max_freq;
                cpufreq_cpu_put(policy);
        } else {
                /*
                 * Default to measured freq if none found, PCU will ensure we
                 * don't go over
                 */
                max_ia_freq = tsc_khz;
        }

        /* Convert from kHz to MHz */
        max_ia_freq /= 1000;

        min_ring_freq = I915_READ(DCLK) & 0xf;
        /* convert DDR frequency from units of 266.6MHz to bandwidth */
        min_ring_freq = mult_frac(min_ring_freq, 8, 3);

        if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                /* Convert GT frequency to 50 HZ units */
                min_gpu_freq = dev_priv->rps.min_freq / GEN9_FREQ_SCALER;
                max_gpu_freq = dev_priv->rps.max_freq / GEN9_FREQ_SCALER;
        } else {
                min_gpu_freq = dev_priv->rps.min_freq;
                max_gpu_freq = dev_priv->rps.max_freq;
        }

        /*
         * For each potential GPU frequency, load a ring frequency we'd like
         * to use for memory access.  We do this by specifying the IA frequency
         * the PCU should use as a reference to determine the ring frequency.
         */
        for (gpu_freq = max_gpu_freq; gpu_freq >= min_gpu_freq; gpu_freq--) {
                int diff = max_gpu_freq - gpu_freq;
                unsigned int ia_freq = 0, ring_freq = 0;

                if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                        /*
                         * ring_freq = 2 * GT. ring_freq is in 100MHz units
                         * No floor required for ring frequency on SKL.
                         */
                        ring_freq = gpu_freq;
                } else if (INTEL_INFO(dev_priv)->gen >= 8) {
                        /* max(2 * GT, DDR). NB: GT is 50MHz units */
                        ring_freq = max(min_ring_freq, gpu_freq);
                } else if (IS_HASWELL(dev_priv)) {
                        ring_freq = mult_frac(gpu_freq, 5, 4);
                        ring_freq = max(min_ring_freq, ring_freq);
                        /* leave ia_freq as the default, chosen by cpufreq */
                } else {
                        /* On older processors, there is no separate ring
                         * clock domain, so in order to boost the bandwidth
                         * of the ring, we need to upclock the CPU (ia_freq).
                         *
                         * For GPU frequencies less than 750MHz,
                         * just use the lowest ring freq.
                         */
                        if (gpu_freq < min_freq)
                                ia_freq = 800;
                        else
                                ia_freq = max_ia_freq - ((diff * scaling_factor) / 2);
                        ia_freq = DIV_ROUND_CLOSEST(ia_freq, 100);
                }

                sandybridge_pcode_write(dev_priv,
                                        GEN6_PCODE_WRITE_MIN_FREQ_TABLE,
                                        ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT |
                                        ring_freq << GEN6_PCODE_FREQ_RING_RATIO_SHIFT |
                                        gpu_freq);
        }
}

static int cherryview_rps_max_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rp0;

        val = vlv_punit_read(dev_priv, FB_GFX_FMAX_AT_VMAX_FUSE);

        switch (INTEL_INFO(dev_priv)->sseu.eu_total) {
        case 8:
                /* (2 * 4) config */
                rp0 = (val >> FB_GFX_FMAX_AT_VMAX_2SS4EU_FUSE_SHIFT);
                break;
        case 12:
                /* (2 * 6) config */
                rp0 = (val >> FB_GFX_FMAX_AT_VMAX_2SS6EU_FUSE_SHIFT);
                break;
        case 16:
                /* (2 * 8) config */
        default:
                /* Setting (2 * 8) Min RP0 for any other combination */
                rp0 = (val >> FB_GFX_FMAX_AT_VMAX_2SS8EU_FUSE_SHIFT);
                break;
        }

        rp0 = (rp0 & FB_GFX_FREQ_FUSE_MASK);

        return rp0;
}

static int cherryview_rps_rpe_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rpe;

        val = vlv_punit_read(dev_priv, PUNIT_GPU_DUTYCYCLE_REG);
        rpe = (val >> PUNIT_GPU_DUTYCYCLE_RPE_FREQ_SHIFT) & PUNIT_GPU_DUTYCYCLE_RPE_FREQ_MASK;

        return rpe;
}

static int cherryview_rps_guar_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rp1;

        val = vlv_punit_read(dev_priv, FB_GFX_FMAX_AT_VMAX_FUSE);
        rp1 = (val & FB_GFX_FREQ_FUSE_MASK);

        return rp1;
}

static u32 cherryview_rps_min_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rpn;

        val = vlv_punit_read(dev_priv, FB_GFX_FMIN_AT_VMIN_FUSE);
        rpn = ((val >> FB_GFX_FMIN_AT_VMIN_FUSE_SHIFT) &
                       FB_GFX_FREQ_FUSE_MASK);

        return rpn;
}

static int valleyview_rps_guar_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rp1;

        val = vlv_nc_read(dev_priv, IOSF_NC_FB_GFX_FREQ_FUSE);

        rp1 = (val & FB_GFX_FGUARANTEED_FREQ_FUSE_MASK) >> FB_GFX_FGUARANTEED_FREQ_FUSE_SHIFT;

        return rp1;
}

static int valleyview_rps_max_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rp0;

        val = vlv_nc_read(dev_priv, IOSF_NC_FB_GFX_FREQ_FUSE);

        rp0 = (val & FB_GFX_MAX_FREQ_FUSE_MASK) >> FB_GFX_MAX_FREQ_FUSE_SHIFT;
        /* Clamp to max */
        rp0 = min_t(u32, rp0, 0xea);

        return rp0;
}

static int valleyview_rps_rpe_freq(struct drm_i915_private *dev_priv)
{
        u32 val, rpe;

        val = vlv_nc_read(dev_priv, IOSF_NC_FB_GFX_FMAX_FUSE_LO);
        rpe = (val & FB_FMAX_VMIN_FREQ_LO_MASK) >> FB_FMAX_VMIN_FREQ_LO_SHIFT;
        val = vlv_nc_read(dev_priv, IOSF_NC_FB_GFX_FMAX_FUSE_HI);
        rpe |= (val & FB_FMAX_VMIN_FREQ_HI_MASK) << 5;

        return rpe;
}

static int valleyview_rps_min_freq(struct drm_i915_private *dev_priv)
{
        u32 val;

        val = vlv_punit_read(dev_priv, PUNIT_REG_GPU_LFM) & 0xff;
        /*
         * According to the BYT Punit GPU turbo HAS 1.1.6.3 the minimum value
         * for the minimum frequency in GPLL mode is 0xc1. Contrary to this on
         * a BYT-M B0 the above register contains 0xbf. Moreover when setting
         * a frequency Punit will not allow values below 0xc0. Clamp it 0xc0
         * to make sure it matches what Punit accepts.
         */
        return max_t(u32, val, 0xc0);
}

/* Check that the pctx buffer wasn't move under us. */
static void valleyview_check_pctx(struct drm_i915_private *dev_priv)
{
        unsigned long pctx_addr = I915_READ(VLV_PCBR) & ~4095;

        WARN_ON(pctx_addr != dev_priv->mm.stolen_base +
                             dev_priv->vlv_pctx->stolen->start);
}


/* Check that the pcbr address is not empty. */
static void cherryview_check_pctx(struct drm_i915_private *dev_priv)
{
        unsigned long pctx_addr = I915_READ(VLV_PCBR) & ~4095;

        WARN_ON((pctx_addr >> VLV_PCBR_ADDR_SHIFT) == 0);
}

static void cherryview_setup_pctx(struct drm_i915_private *dev_priv)
{
        struct i915_ggtt *ggtt = &dev_priv->ggtt;
        unsigned long pctx_paddr, paddr;
        u32 pcbr;
        int pctx_size = 32*1024;

        pcbr = I915_READ(VLV_PCBR);
        if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
                DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");
                paddr = (dev_priv->mm.stolen_base +
                         (ggtt->stolen_size - pctx_size));

                pctx_paddr = (paddr & (~4095));
                I915_WRITE(VLV_PCBR, pctx_paddr);
        }

        DRM_DEBUG_DRIVER("PCBR: 0x%08x\n", I915_READ(VLV_PCBR));
}

static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
{
        struct drm_i915_gem_object *pctx;
        unsigned long pctx_paddr;
        u32 pcbr;
        int pctx_size = 24*1024;

        pcbr = I915_READ(VLV_PCBR);
        if (pcbr) {
                /* BIOS set it up already, grab the pre-alloc'd space */
                int pcbr_offset;

                pcbr_offset = (pcbr & (~4095)) - dev_priv->mm.stolen_base;
                pctx = i915_gem_object_create_stolen_for_preallocated(dev_priv,
                                                                      pcbr_offset,
                                                                      I915_GTT_OFFSET_NONE,
                                                                      pctx_size);
                goto out;
        }

        DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");

        /*
         * From the Gunit register HAS:
         * The Gfx driver is expected to program this register and ensure
         * proper allocation within Gfx stolen memory.  For example, this
         * register should be programmed such than the PCBR range does not
         * overlap with other ranges, such as the frame buffer, protected
         * memory, or any other relevant ranges.
         */
        pctx = i915_gem_object_create_stolen(dev_priv, pctx_size);
        if (!pctx) {
                DRM_DEBUG("not enough stolen space for PCTX, disabling\n");
                goto out;
        }

        pctx_paddr = dev_priv->mm.stolen_base + pctx->stolen->start;
        I915_WRITE(VLV_PCBR, pctx_paddr);

out:
        DRM_DEBUG_DRIVER("PCBR: 0x%08x\n", I915_READ(VLV_PCBR));
        dev_priv->vlv_pctx = pctx;
}

static void valleyview_cleanup_pctx(struct drm_i915_private *dev_priv)
{
        if (WARN_ON(!dev_priv->vlv_pctx))
                return;

        i915_gem_object_put(dev_priv->vlv_pctx);
        dev_priv->vlv_pctx = NULL;
}

static void vlv_init_gpll_ref_freq(struct drm_i915_private *dev_priv)
{
        dev_priv->rps.gpll_ref_freq =
                vlv_get_cck_clock(dev_priv, "GPLL ref",
                                  CCK_GPLL_CLOCK_CONTROL,
                                  dev_priv->czclk_freq);

        DRM_DEBUG_DRIVER("GPLL reference freq: %d kHz\n",
                         dev_priv->rps.gpll_ref_freq);
}

static void valleyview_init_gt_powersave(struct drm_i915_private *dev_priv)
{
        u32 val;

        valleyview_setup_pctx(dev_priv);

        vlv_init_gpll_ref_freq(dev_priv);

        val = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS);
        switch ((val >> 6) & 3) {
        case 0:
        case 1:
                dev_priv->mem_freq = 800;
                break;
        case 2:
                dev_priv->mem_freq = 1066;
                break;
        case 3:
                dev_priv->mem_freq = 1333;
                break;
        }
        DRM_DEBUG_DRIVER("DDR speed: %d MHz\n", dev_priv->mem_freq);

        dev_priv->rps.max_freq = valleyview_rps_max_freq(dev_priv);
        dev_priv->rps.rp0_freq = dev_priv->rps.max_freq;
        DRM_DEBUG_DRIVER("max GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.max_freq),
                         dev_priv->rps.max_freq);

        dev_priv->rps.efficient_freq = valleyview_rps_rpe_freq(dev_priv);
        DRM_DEBUG_DRIVER("RPe GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
                         dev_priv->rps.efficient_freq);

        dev_priv->rps.rp1_freq = valleyview_rps_guar_freq(dev_priv);
        DRM_DEBUG_DRIVER("RP1(Guar Freq) GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.rp1_freq),
                         dev_priv->rps.rp1_freq);

        dev_priv->rps.min_freq = valleyview_rps_min_freq(dev_priv);
        DRM_DEBUG_DRIVER("min GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.min_freq),
                         dev_priv->rps.min_freq);
}

static void cherryview_init_gt_powersave(struct drm_i915_private *dev_priv)
{
        u32 val;

        cherryview_setup_pctx(dev_priv);

        vlv_init_gpll_ref_freq(dev_priv);

        mutex_lock(&dev_priv->sb_lock);
        val = vlv_cck_read(dev_priv, CCK_FUSE_REG);
        mutex_unlock(&dev_priv->sb_lock);

        switch ((val >> 2) & 0x7) {
        case 3:
                dev_priv->mem_freq = 2000;
                break;
        default:
                dev_priv->mem_freq = 1600;
                break;
        }
        DRM_DEBUG_DRIVER("DDR speed: %d MHz\n", dev_priv->mem_freq);

        dev_priv->rps.max_freq = cherryview_rps_max_freq(dev_priv);
        dev_priv->rps.rp0_freq = dev_priv->rps.max_freq;
        DRM_DEBUG_DRIVER("max GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.max_freq),
                         dev_priv->rps.max_freq);

        dev_priv->rps.efficient_freq = cherryview_rps_rpe_freq(dev_priv);
        DRM_DEBUG_DRIVER("RPe GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
                         dev_priv->rps.efficient_freq);

        dev_priv->rps.rp1_freq = cherryview_rps_guar_freq(dev_priv);
        DRM_DEBUG_DRIVER("RP1(Guar) GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.rp1_freq),
                         dev_priv->rps.rp1_freq);

        dev_priv->rps.min_freq = cherryview_rps_min_freq(dev_priv);
        DRM_DEBUG_DRIVER("min GPU freq: %d MHz (%u)\n",
                         intel_gpu_freq(dev_priv, dev_priv->rps.min_freq),
                         dev_priv->rps.min_freq);

        WARN_ONCE((dev_priv->rps.max_freq |
                   dev_priv->rps.efficient_freq |
                   dev_priv->rps.rp1_freq |
                   dev_priv->rps.min_freq) & 1,
                  "Odd GPU freq values\n");
}

static void valleyview_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
{
        valleyview_cleanup_pctx(dev_priv);
}

static void cherryview_enable_rps(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        u32 gtfifodbg, val, rc6_mode = 0, pcbr;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        gtfifodbg = I915_READ(GTFIFODBG) & ~(GT_FIFO_SBDEDICATE_FREE_ENTRY_CHV |
                                             GT_FIFO_FREE_ENTRIES_CHV);
        if (gtfifodbg) {
                DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
                                 gtfifodbg);
                I915_WRITE(GTFIFODBG, gtfifodbg);
        }

        cherryview_check_pctx(dev_priv);

        /* 1a & 1b: Get forcewake during program sequence. Although the driver
         * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /*  Disable RC states. */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        /* 2a: Program RC6 thresholds.*/
        I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */

        for_each_engine(engine, dev_priv, id)
                I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
        I915_WRITE(GEN6_RC_SLEEP, 0);

        /* TO threshold set to 500 us ( 0x186 * 1.28 us) */
        I915_WRITE(GEN6_RC6_THRESHOLD, 0x186);

        /* allows RC6 residency counter to work */
        I915_WRITE(VLV_COUNTER_CONTROL,
                   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
                                      VLV_MEDIA_RC6_COUNT_EN |
                                      VLV_RENDER_RC6_COUNT_EN));

        /* For now we assume BIOS is allocating and populating the PCBR  */
        pcbr = I915_READ(VLV_PCBR);

        /* 3: Enable RC6 */
        if ((intel_enable_rc6() & INTEL_RC6_ENABLE) &&
            (pcbr >> VLV_PCBR_ADDR_SHIFT))
                rc6_mode = GEN7_RC_CTL_TO_MODE;

        I915_WRITE(GEN6_RC_CONTROL, rc6_mode);

        /* 4 Program defaults and thresholds for RPS*/
        I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 1000000);
        I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
        I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 245000);
        I915_WRITE(GEN6_RP_UP_EI, 66000);
        I915_WRITE(GEN6_RP_DOWN_EI, 350000);

        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);

        /* 5: Enable RPS */
        I915_WRITE(GEN6_RP_CONTROL,
                   GEN6_RP_MEDIA_HW_NORMAL_MODE |
                   GEN6_RP_MEDIA_IS_GFX |
                   GEN6_RP_ENABLE |
                   GEN6_RP_UP_BUSY_AVG |
                   GEN6_RP_DOWN_IDLE_AVG);

        /* Setting Fixed Bias */
        val = VLV_OVERRIDE_EN |
                  VLV_SOC_TDP_EN |
                  CHV_BIAS_CPU_50_SOC_50;
        vlv_punit_write(dev_priv, VLV_TURBO_SOC_OVERRIDE, val);

        val = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS);

        /* RPS code assumes GPLL is used */
        WARN_ONCE((val & GPLLENABLE) == 0, "GPLL not enabled\n");

        DRM_DEBUG_DRIVER("GPLL enabled? %s\n", yesno(val & GPLLENABLE));
        DRM_DEBUG_DRIVER("GPU status: 0x%08x\n", val);

        reset_rps(dev_priv, valleyview_set_rps);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static void valleyview_enable_rps(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        u32 gtfifodbg, val, rc6_mode = 0;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        valleyview_check_pctx(dev_priv);

        gtfifodbg = I915_READ(GTFIFODBG);
        if (gtfifodbg) {
                DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
                                 gtfifodbg);
                I915_WRITE(GTFIFODBG, gtfifodbg);
        }

        /* If VLV, Forcewake all wells, else re-direct to regular path */
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

        /*  Disable RC states. */
        I915_WRITE(GEN6_RC_CONTROL, 0);

        I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 1000000);
        I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
        I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 245000);
        I915_WRITE(GEN6_RP_UP_EI, 66000);
        I915_WRITE(GEN6_RP_DOWN_EI, 350000);

        I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);

        I915_WRITE(GEN6_RP_CONTROL,
                   GEN6_RP_MEDIA_TURBO |
                   GEN6_RP_MEDIA_HW_NORMAL_MODE |
                   GEN6_RP_MEDIA_IS_GFX |
                   GEN6_RP_ENABLE |
                   GEN6_RP_UP_BUSY_AVG |
                   GEN6_RP_DOWN_IDLE_CONT);

        I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 0x00280000);
        I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
        I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);

        for_each_engine(engine, dev_priv, id)
                I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);

        I915_WRITE(GEN6_RC6_THRESHOLD, 0x557);

        /* allows RC6 residency counter to work */
        I915_WRITE(VLV_COUNTER_CONTROL,
                   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
                                      VLV_MEDIA_RC0_COUNT_EN |
                                      VLV_RENDER_RC0_COUNT_EN |
                                      VLV_MEDIA_RC6_COUNT_EN |
                                      VLV_RENDER_RC6_COUNT_EN));

        if (intel_enable_rc6() & INTEL_RC6_ENABLE)
                rc6_mode = GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;

        intel_print_rc6_info(dev_priv, rc6_mode);

        I915_WRITE(GEN6_RC_CONTROL, rc6_mode);

        /* Setting Fixed Bias */
        val = VLV_OVERRIDE_EN |
                  VLV_SOC_TDP_EN |
                  VLV_BIAS_CPU_125_SOC_875;
        vlv_punit_write(dev_priv, VLV_TURBO_SOC_OVERRIDE, val);

        val = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS);

        /* RPS code assumes GPLL is used */
        WARN_ONCE((val & GPLLENABLE) == 0, "GPLL not enabled\n");

        DRM_DEBUG_DRIVER("GPLL enabled? %s\n", yesno(val & GPLLENABLE));
        DRM_DEBUG_DRIVER("GPU status: 0x%08x\n", val);

        reset_rps(dev_priv, valleyview_set_rps);

        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

static unsigned long intel_pxfreq(u32 vidfreq)
{
        unsigned long freq;
        int div = (vidfreq & 0x3f0000) >> 16;
        int post = (vidfreq & 0x3000) >> 12;
        int pre = (vidfreq & 0x7);

        if (!pre)
                return 0;

        freq = ((div * 133333) / ((1<<post) * pre));

        return freq;
}

static const struct cparams {
        u16 i;
        u16 t;
        u16 m;
        u16 c;
} cparams[] = {
        { 1, 1333, 301, 28664 },
        { 1, 1066, 294, 24460 },
        { 1, 800, 294, 25192 },
        { 0, 1333, 276, 27605 },
        { 0, 1066, 276, 27605 },
        { 0, 800, 231, 23784 },
};

static unsigned long __i915_chipset_val(struct drm_i915_private *dev_priv)
{
        u64 total_count, diff, ret;
        u32 count1, count2, count3, m = 0, c = 0;
        unsigned long now = jiffies_to_msecs(jiffies), diff1;
        int i;

        lockdep_assert_held(&mchdev_lock);

        diff1 = now - dev_priv->ips.last_time1;

        /* Prevent division-by-zero if we are asking too fast.
         * Also, we don't get interesting results if we are polling
         * faster than once in 10ms, so just return the saved value
         * in such cases.
         */
        if (diff1 <= 10)
                return dev_priv->ips.chipset_power;

        count1 = I915_READ(DMIEC);
        count2 = I915_READ(DDREC);
        count3 = I915_READ(CSIEC);

        total_count = count1 + count2 + count3;

        /* FIXME: handle per-counter overflow */
        if (total_count < dev_priv->ips.last_count1) {
                diff = ~0UL - dev_priv->ips.last_count1;
                diff += total_count;
        } else {
                diff = total_count - dev_priv->ips.last_count1;
        }

        for (i = 0; i < ARRAY_SIZE(cparams); i++) {
                if (cparams[i].i == dev_priv->ips.c_m &&
                    cparams[i].t == dev_priv->ips.r_t) {
                        m = cparams[i].m;
                        c = cparams[i].c;
                        break;
                }
        }

        diff = div_u64(diff, diff1);
        ret = ((m * diff) + c);
        ret = div_u64(ret, 10);

        dev_priv->ips.last_count1 = total_count;
        dev_priv->ips.last_time1 = now;

        dev_priv->ips.chipset_power = ret;

        return ret;
}

unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
{
        unsigned long val;

        if (INTEL_INFO(dev_priv)->gen != 5)
                return 0;

        spin_lock_irq(&mchdev_lock);

        val = __i915_chipset_val(dev_priv);

        spin_unlock_irq(&mchdev_lock);

        return val;
}

unsigned long i915_mch_val(struct drm_i915_private *dev_priv)
{
        unsigned long m, x, b;
        u32 tsfs;

        tsfs = I915_READ(TSFS);

        m = ((tsfs & TSFS_SLOPE_MASK) >> TSFS_SLOPE_SHIFT);
        x = I915_READ8(TR1);

        b = tsfs & TSFS_INTR_MASK;

        return ((m * x) / 127) - b;
}

static int _pxvid_to_vd(u8 pxvid)
{
        if (pxvid == 0)
                return 0;

        if (pxvid >= 8 && pxvid < 31)
                pxvid = 31;

        return (pxvid + 2) * 125;
}

static u32 pvid_to_extvid(struct drm_i915_private *dev_priv, u8 pxvid)
{
        const int vd = _pxvid_to_vd(pxvid);
        const int vm = vd - 1125;

        if (INTEL_INFO(dev_priv)->is_mobile)
                return vm > 0 ? vm : 0;

        return vd;
}

static void __i915_update_gfx_val(struct drm_i915_private *dev_priv)
{
        u64 now, diff, diffms;
        u32 count;

        lockdep_assert_held(&mchdev_lock);

        now = ktime_get_raw_ns();
        diffms = now - dev_priv->ips.last_time2;
        do_div(diffms, NSEC_PER_MSEC);

        /* Don't divide by 0 */
        if (!diffms)
                return;

        count = I915_READ(GFXEC);

        if (count < dev_priv->ips.last_count2) {
                diff = ~0UL - dev_priv->ips.last_count2;
                diff += count;
        } else {
                diff = count - dev_priv->ips.last_count2;
        }

        dev_priv->ips.last_count2 = count;
        dev_priv->ips.last_time2 = now;

        /* More magic constants... */
        diff = diff * 1181;
        diff = div_u64(diff, diffms * 10);
        dev_priv->ips.gfx_power = diff;
}

void i915_update_gfx_val(struct drm_i915_private *dev_priv)
{
        if (INTEL_INFO(dev_priv)->gen != 5)
                return;

        spin_lock_irq(&mchdev_lock);

        __i915_update_gfx_val(dev_priv);

        spin_unlock_irq(&mchdev_lock);
}

static unsigned long __i915_gfx_val(struct drm_i915_private *dev_priv)
{
        unsigned long t, corr, state1, corr2, state2;
        u32 pxvid, ext_v;

        lockdep_assert_held(&mchdev_lock);

        pxvid = I915_READ(PXVFREQ(dev_priv->rps.cur_freq));
        pxvid = (pxvid >> 24) & 0x7f;
        ext_v = pvid_to_extvid(dev_priv, pxvid);

        state1 = ext_v;

        t = i915_mch_val(dev_priv);

        /* Revel in the empirically derived constants */

        /* Correction factor in 1/100000 units */
        if (t > 80)
                corr = ((t * 2349) + 135940);
        else if (t >= 50)
                corr = ((t * 964) + 29317);
        else /* < 50 */
                corr = ((t * 301) + 1004);

        corr = corr * ((150142 * state1) / 10000 - 78642);
        corr /= 100000;
        corr2 = (corr * dev_priv->ips.corr);

        state2 = (corr2 * state1) / 10000;
        state2 /= 100; /* convert to mW */

        __i915_update_gfx_val(dev_priv);

        return dev_priv->ips.gfx_power + state2;
}

unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
{
        unsigned long val;

        if (INTEL_INFO(dev_priv)->gen != 5)
                return 0;

        spin_lock_irq(&mchdev_lock);

        val = __i915_gfx_val(dev_priv);

        spin_unlock_irq(&mchdev_lock);

        return val;
}

/**
 * i915_read_mch_val - return value for IPS use
 *
 * Calculate and return a value for the IPS driver to use when deciding whether
 * we have thermal and power headroom to increase CPU or GPU power budget.
 */
unsigned long i915_read_mch_val(void)
{
        struct drm_i915_private *dev_priv;
        unsigned long chipset_val, graphics_val, ret = 0;

        spin_lock_irq(&mchdev_lock);
        if (!i915_mch_dev)
                goto out_unlock;
        dev_priv = i915_mch_dev;

        chipset_val = __i915_chipset_val(dev_priv);
        graphics_val = __i915_gfx_val(dev_priv);

        ret = chipset_val + graphics_val;

out_unlock:
        spin_unlock_irq(&mchdev_lock);

        return ret;
}
EXPORT_SYMBOL_GPL(i915_read_mch_val);

/**
 * i915_gpu_raise - raise GPU frequency limit
 *
 * Raise the limit; IPS indicates we have thermal headroom.
 */
bool i915_gpu_raise(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        spin_lock_irq(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        if (dev_priv->ips.max_delay > dev_priv->ips.fmax)
                dev_priv->ips.max_delay--;

out_unlock:
        spin_unlock_irq(&mchdev_lock);

        return ret;
}
EXPORT_SYMBOL_GPL(i915_gpu_raise);

/**
 * i915_gpu_lower - lower GPU frequency limit
 *
 * IPS indicates we're close to a thermal limit, so throttle back the GPU
 * frequency maximum.
 */
bool i915_gpu_lower(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        spin_lock_irq(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        if (dev_priv->ips.max_delay < dev_priv->ips.min_delay)
                dev_priv->ips.max_delay++;

out_unlock:
        spin_unlock_irq(&mchdev_lock);

        return ret;
}
EXPORT_SYMBOL_GPL(i915_gpu_lower);

/**
 * i915_gpu_busy - indicate GPU business to IPS
 *
 * Tell the IPS driver whether or not the GPU is busy.
 */
bool i915_gpu_busy(void)
{
        bool ret = false;

        spin_lock_irq(&mchdev_lock);
        if (i915_mch_dev)
                ret = i915_mch_dev->gt.awake;
        spin_unlock_irq(&mchdev_lock);

        return ret;
}
EXPORT_SYMBOL_GPL(i915_gpu_busy);

/**
 * i915_gpu_turbo_disable - disable graphics turbo
 *
 * Disable graphics turbo by resetting the max frequency and setting the
 * current frequency to the default.
 */
bool i915_gpu_turbo_disable(void)
{
        struct drm_i915_private *dev_priv;
        bool ret = true;

        spin_lock_irq(&mchdev_lock);
        if (!i915_mch_dev) {
                ret = false;
                goto out_unlock;
        }
        dev_priv = i915_mch_dev;

        dev_priv->ips.max_delay = dev_priv->ips.fstart;

        if (!ironlake_set_drps(dev_priv, dev_priv->ips.fstart))
                ret = false;

out_unlock:
        spin_unlock_irq(&mchdev_lock);

        return ret;
}
EXPORT_SYMBOL_GPL(i915_gpu_turbo_disable);

/**
 * Tells the intel_ips driver that the i915 driver is now loaded, if
 * IPS got loaded first.
 *
 * This awkward dance is so that neither module has to depend on the
 * other in order for IPS to do the appropriate communication of
 * GPU turbo limits to i915.
 */
static void
ips_ping_for_i915_load(void)
{
        void (*link)(void);

        link = symbol_get(ips_link_to_i915_driver);
        if (link) {
                link();
                symbol_put(ips_link_to_i915_driver);
        }
}

void intel_gpu_ips_init(struct drm_i915_private *dev_priv)
{
        /* We only register the i915 ips part with intel-ips once everything is
         * set up, to avoid intel-ips sneaking in and reading bogus values. */
        spin_lock_irq(&mchdev_lock);
        i915_mch_dev = dev_priv;
        spin_unlock_irq(&mchdev_lock);

        ips_ping_for_i915_load();
}

void intel_gpu_ips_teardown(void)
{
        spin_lock_irq(&mchdev_lock);
        i915_mch_dev = NULL;
        spin_unlock_irq(&mchdev_lock);
}

static void intel_init_emon(struct drm_i915_private *dev_priv)
{
        u32 lcfuse;
        u8 pxw[16];
        int i;

        /* Disable to program */
        I915_WRITE(ECR, 0);
        POSTING_READ(ECR);

        /* Program energy weights for various events */
        I915_WRITE(SDEW, 0x15040d00);
        I915_WRITE(CSIEW0, 0x007f0000);
        I915_WRITE(CSIEW1, 0x1e220004);
        I915_WRITE(CSIEW2, 0x04000004);

        for (i = 0; i < 5; i++)
                I915_WRITE(PEW(i), 0);
        for (i = 0; i < 3; i++)
                I915_WRITE(DEW(i), 0);

        /* Program P-state weights to account for frequency power adjustment */
        for (i = 0; i < 16; i++) {
                u32 pxvidfreq = I915_READ(PXVFREQ(i));
                unsigned long freq = intel_pxfreq(pxvidfreq);
                unsigned long vid = (pxvidfreq & PXVFREQ_PX_MASK) >>
                        PXVFREQ_PX_SHIFT;
                unsigned long val;

                val = vid * vid;
                val *= (freq / 1000);
                val *= 255;
                val /= (127*127*900);
                if (val > 0xff)
                        DRM_ERROR("bad pxval: %ld\n", val);
                pxw[i] = val;
        }
        /* Render standby states get 0 weight */
        pxw[14] = 0;
        pxw[15] = 0;

        for (i = 0; i < 4; i++) {
                u32 val = (pxw[i*4] << 24) | (pxw[(i*4)+1] << 16) |
                        (pxw[(i*4)+2] << 8) | (pxw[(i*4)+3]);
                I915_WRITE(PXW(i), val);
        }

        /* Adjust magic regs to magic values (more experimental results) */
        I915_WRITE(OGW0, 0);
        I915_WRITE(OGW1, 0);
        I915_WRITE(EG0, 0x00007f00);
        I915_WRITE(EG1, 0x0000000e);
        I915_WRITE(EG2, 0x000e0000);
        I915_WRITE(EG3, 0x68000300);
        I915_WRITE(EG4, 0x42000000);
        I915_WRITE(EG5, 0x00140031);
        I915_WRITE(EG6, 0);
        I915_WRITE(EG7, 0);

        for (i = 0; i < 8; i++)
                I915_WRITE(PXWL(i), 0);

        /* Enable PMON + select events */
        I915_WRITE(ECR, 0x80000019);

        lcfuse = I915_READ(LCFUSE02);

        dev_priv->ips.corr = (lcfuse & LCFUSE_HIV_MASK);
}

void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
{
        /*
         * RPM depends on RC6 to save restore the GT HW context, so make RC6 a
         * requirement.
         */
        if (!i915_modparams.enable_rc6) {
                DRM_INFO("RC6 disabled, disabling runtime PM support\n");
                intel_runtime_pm_get(dev_priv);
        }

        mutex_lock(&dev_priv->drm.struct_mutex);
        mutex_lock(&dev_priv->rps.hw_lock);

        /* Initialize RPS limits (for userspace) */
        if (IS_CHERRYVIEW(dev_priv))
                cherryview_init_gt_powersave(dev_priv);
        else if (IS_VALLEYVIEW(dev_priv))
                valleyview_init_gt_powersave(dev_priv);
        else if (INTEL_GEN(dev_priv) >= 6)
                gen6_init_rps_frequencies(dev_priv);

        /* Derive initial user preferences/limits from the hardware limits */
        dev_priv->rps.idle_freq = dev_priv->rps.min_freq;
        dev_priv->rps.cur_freq = dev_priv->rps.idle_freq;

        dev_priv->rps.max_freq_softlimit = dev_priv->rps.max_freq;
        dev_priv->rps.min_freq_softlimit = dev_priv->rps.min_freq;

        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                dev_priv->rps.min_freq_softlimit =
                        max_t(int,
                              dev_priv->rps.efficient_freq,
                              intel_freq_opcode(dev_priv, 450));

        /* After setting max-softlimit, find the overclock max freq */
        if (IS_GEN6(dev_priv) ||
            IS_IVYBRIDGE(dev_priv) || IS_HASWELL(dev_priv)) {
                u32 params = 0;

                sandybridge_pcode_read(dev_priv, GEN6_READ_OC_PARAMS, &params);
                if (params & BIT(31)) { /* OC supported */
                        DRM_DEBUG_DRIVER("Overclocking supported, max: %dMHz, overclock: %dMHz\n",
                                         (dev_priv->rps.max_freq & 0xff) * 50,
                                         (params & 0xff) * 50);
                        dev_priv->rps.max_freq = params & 0xff;
                }
        }

        /* Finally allow us to boost to max by default */
        dev_priv->rps.boost_freq = dev_priv->rps.max_freq;

        mutex_unlock(&dev_priv->rps.hw_lock);
        mutex_unlock(&dev_priv->drm.struct_mutex);

        intel_autoenable_gt_powersave(dev_priv);
}

void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
{
        if (IS_VALLEYVIEW(dev_priv))
                valleyview_cleanup_gt_powersave(dev_priv);

        if (!i915_modparams.enable_rc6)
                intel_runtime_pm_put(dev_priv);
}

/**
 * intel_suspend_gt_powersave - suspend PM work and helper threads
 * @dev_priv: i915 device
 *
 * We don't want to disable RC6 or other features here, we just want
 * to make sure any work we've queued has finished and won't bother
 * us while we're suspended.
 */
void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv)
{
        if (INTEL_GEN(dev_priv) < 6)
                return;

        if (cancel_delayed_work_sync(&dev_priv->rps.autoenable_work))
                intel_runtime_pm_put(dev_priv);

        /* gen6_rps_idle() will be called later to disable interrupts */
}

void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv)
{
        dev_priv->rps.enabled = true; /* force disabling */
        intel_disable_gt_powersave(dev_priv);

        gen6_reset_rps_interrupts(dev_priv);
}

void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
{
        if (!READ_ONCE(dev_priv->rps.enabled))
                return;

        mutex_lock(&dev_priv->rps.hw_lock);

        if (INTEL_GEN(dev_priv) >= 9) {
                gen9_disable_rc6(dev_priv);
                gen9_disable_rps(dev_priv);
        } else if (IS_CHERRYVIEW(dev_priv)) {
                cherryview_disable_rps(dev_priv);
        } else if (IS_VALLEYVIEW(dev_priv)) {
                valleyview_disable_rps(dev_priv);
        } else if (INTEL_GEN(dev_priv) >= 6) {
                gen6_disable_rps(dev_priv);
        }  else if (IS_IRONLAKE_M(dev_priv)) {
                ironlake_disable_drps(dev_priv);
        }

        dev_priv->rps.enabled = false;
        mutex_unlock(&dev_priv->rps.hw_lock);
}

void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
{
        /* We shouldn't be disabling as we submit, so this should be less
         * racy than it appears!
         */
        if (READ_ONCE(dev_priv->rps.enabled))
                return;

        /* Powersaving is controlled by the host when inside a VM */
        if (intel_vgpu_active(dev_priv))
                return;

        mutex_lock(&dev_priv->rps.hw_lock);

        if (IS_CHERRYVIEW(dev_priv)) {
                cherryview_enable_rps(dev_priv);
        } else if (IS_VALLEYVIEW(dev_priv)) {
                valleyview_enable_rps(dev_priv);
        } else if (INTEL_GEN(dev_priv) >= 9) {
                gen9_enable_rc6(dev_priv);
                gen9_enable_rps(dev_priv);
                if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv))
                        gen6_update_ring_freq(dev_priv);
        } else if (IS_BROADWELL(dev_priv)) {
                gen8_enable_rps(dev_priv);
                gen6_update_ring_freq(dev_priv);
        } else if (INTEL_GEN(dev_priv) >= 6) {
                gen6_enable_rps(dev_priv);
                gen6_update_ring_freq(dev_priv);
        } else if (IS_IRONLAKE_M(dev_priv)) {
                ironlake_enable_drps(dev_priv);
                intel_init_emon(dev_priv);
        }

        WARN_ON(dev_priv->rps.max_freq < dev_priv->rps.min_freq);
        WARN_ON(dev_priv->rps.idle_freq > dev_priv->rps.max_freq);

        WARN_ON(dev_priv->rps.efficient_freq < dev_priv->rps.min_freq);
        WARN_ON(dev_priv->rps.efficient_freq > dev_priv->rps.max_freq);

        dev_priv->rps.enabled = true;
        mutex_unlock(&dev_priv->rps.hw_lock);
}

static void __intel_autoenable_gt_powersave(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, typeof(*dev_priv), rps.autoenable_work.work);
        struct intel_engine_cs *rcs;
        struct drm_i915_gem_request *req;

        if (READ_ONCE(dev_priv->rps.enabled))
                goto out;

        rcs = dev_priv->engine[RCS];
        if (rcs->last_retired_context)
                goto out;

        if (!rcs->init_context)
                goto out;

        mutex_lock(&dev_priv->drm.struct_mutex);

        req = i915_gem_request_alloc(rcs, dev_priv->kernel_context);
        if (IS_ERR(req))
                goto unlock;

        if (!i915_modparams.enable_execlists && i915_switch_context(req) == 0)
                rcs->init_context(req);

        /* Mark the device busy, calling intel_enable_gt_powersave() */
        i915_add_request(req);

unlock:
        mutex_unlock(&dev_priv->drm.struct_mutex);
out:
        intel_runtime_pm_put(dev_priv);
}

void intel_autoenable_gt_powersave(struct drm_i915_private *dev_priv)
{
        if (READ_ONCE(dev_priv->rps.enabled))
                return;

        if (IS_IRONLAKE_M(dev_priv)) {
                ironlake_enable_drps(dev_priv);
                intel_init_emon(dev_priv);
        } else if (INTEL_INFO(dev_priv)->gen >= 6) {
                /*
                 * PCU communication is slow and this doesn't need to be
                 * done at any specific time, so do this out of our fast path
                 * to make resume and init faster.
                 *
                 * We depend on the HW RC6 power context save/restore
                 * mechanism when entering D3 through runtime PM suspend. So
                 * disable RPM until RPS/RC6 is properly setup. We can only
                 * get here via the driver load/system resume/runtime resume
                 * paths, so the _noresume version is enough (and in case of
                 * runtime resume it's necessary).
                 */
                if (queue_delayed_work(dev_priv->wq,
                                       &dev_priv->rps.autoenable_work,
                                       round_jiffies_up_relative(HZ)))
                        intel_runtime_pm_get_noresume(dev_priv);
        }
}

static void ibx_init_clock_gating(struct drm_i915_private *dev_priv)
{
        /*
         * On Ibex Peak and Cougar Point, we need to disable clock
         * gating for the panel power sequencer or it will fail to
         * start up when no ports are active.
         */
        I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
}

static void g4x_disable_trickle_feed(struct drm_i915_private *dev_priv)
{
        enum pipe pipe;

        for_each_pipe(dev_priv, pipe) {
                I915_WRITE(DSPCNTR(pipe),
                           I915_READ(DSPCNTR(pipe)) |
                           DISPPLANE_TRICKLE_FEED_DISABLE);

                I915_WRITE(DSPSURF(pipe), I915_READ(DSPSURF(pipe)));
                POSTING_READ(DSPSURF(pipe));
        }
}

static void ilk_init_lp_watermarks(struct drm_i915_private *dev_priv)
{
        I915_WRITE(WM3_LP_ILK, I915_READ(WM3_LP_ILK) & ~WM1_LP_SR_EN);
        I915_WRITE(WM2_LP_ILK, I915_READ(WM2_LP_ILK) & ~WM1_LP_SR_EN);
        I915_WRITE(WM1_LP_ILK, I915_READ(WM1_LP_ILK) & ~WM1_LP_SR_EN);

        /*
         * Don't touch WM1S_LP_EN here.
         * Doing so could cause underruns.
         */
}

static void ilk_init_clock_gating(struct drm_i915_private *dev_priv)
{
        uint32_t dspclk_gate = ILK_VRHUNIT_CLOCK_GATE_DISABLE;

        /*
         * Required for FBC
         * WaFbcDisableDpfcClockGating:ilk
         */
        dspclk_gate |= ILK_DPFCRUNIT_CLOCK_GATE_DISABLE |
                   ILK_DPFCUNIT_CLOCK_GATE_DISABLE |
                   ILK_DPFDUNIT_CLOCK_GATE_ENABLE;

        I915_WRITE(PCH_3DCGDIS0,
                   MARIUNIT_CLOCK_GATE_DISABLE |
                   SVSMUNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(PCH_3DCGDIS1,
                   VFMUNIT_CLOCK_GATE_DISABLE);

        /*
         * According to the spec the following bits should be set in
         * order to enable memory self-refresh
         * The bit 22/21 of 0x42004
         * The bit 5 of 0x42020
         * The bit 15 of 0x45000
         */
        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   (I915_READ(ILK_DISPLAY_CHICKEN2) |
                    ILK_DPARB_GATE | ILK_VSDPFD_FULL));
        dspclk_gate |= ILK_DPARBUNIT_CLOCK_GATE_ENABLE;
        I915_WRITE(DISP_ARB_CTL,
                   (I915_READ(DISP_ARB_CTL) |
                    DISP_FBC_WM_DIS));

        ilk_init_lp_watermarks(dev_priv);

        /*
         * Based on the document from hardware guys the following bits
         * should be set unconditionally in order to enable FBC.
         * The bit 22 of 0x42000
         * The bit 22 of 0x42004
         * The bit 7,8,9 of 0x42020.
         */
        if (IS_IRONLAKE_M(dev_priv)) {
                /* WaFbcAsynchFlipDisableFbcQueue:ilk */
                I915_WRITE(ILK_DISPLAY_CHICKEN1,
                           I915_READ(ILK_DISPLAY_CHICKEN1) |
                           ILK_FBCQ_DIS);
                I915_WRITE(ILK_DISPLAY_CHICKEN2,
                           I915_READ(ILK_DISPLAY_CHICKEN2) |
                           ILK_DPARB_GATE);
        }

        I915_WRITE(ILK_DSPCLK_GATE_D, dspclk_gate);

        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_ELPIN_409_SELECT);
        I915_WRITE(_3D_CHICKEN2,
                   _3D_CHICKEN2_WM_READ_PIPELINED << 16 |
                   _3D_CHICKEN2_WM_READ_PIPELINED);

        /* WaDisableRenderCachePipelinedFlush:ilk */
        I915_WRITE(CACHE_MODE_0,
                   _MASKED_BIT_ENABLE(CM0_PIPELINED_RENDER_FLUSH_DISABLE));

        /* WaDisable_RenderCache_OperationalFlush:ilk */
        I915_WRITE(CACHE_MODE_0, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        g4x_disable_trickle_feed(dev_priv);

        ibx_init_clock_gating(dev_priv);
}

static void cpt_init_clock_gating(struct drm_i915_private *dev_priv)
{
        int pipe;
        uint32_t val;

        /*
         * On Ibex Peak and Cougar Point, we need to disable clock
         * gating for the panel power sequencer or it will fail to
         * start up when no ports are active.
         */
        I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE |
                   PCH_DPLUNIT_CLOCK_GATE_DISABLE |
                   PCH_CPUNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) |
                   DPLS_EDP_PPS_FIX_DIS);
        /* The below fixes the weird display corruption, a few pixels shifted
         * downward, on (only) LVDS of some HP laptops with IVY.
         */
        for_each_pipe(dev_priv, pipe) {
                val = I915_READ(TRANS_CHICKEN2(pipe));
                val |= TRANS_CHICKEN2_TIMING_OVERRIDE;
                val &= ~TRANS_CHICKEN2_FDI_POLARITY_REVERSED;
                if (dev_priv->vbt.fdi_rx_polarity_inverted)
                        val |= TRANS_CHICKEN2_FDI_POLARITY_REVERSED;
                val &= ~TRANS_CHICKEN2_FRAME_START_DELAY_MASK;
                val &= ~TRANS_CHICKEN2_DISABLE_DEEP_COLOR_COUNTER;
                val &= ~TRANS_CHICKEN2_DISABLE_DEEP_COLOR_MODESWITCH;
                I915_WRITE(TRANS_CHICKEN2(pipe), val);
        }
        /* WADP0ClockGatingDisable */
        for_each_pipe(dev_priv, pipe) {
                I915_WRITE(TRANS_CHICKEN1(pipe),
                           TRANS_CHICKEN1_DP0UNIT_GC_DISABLE);
        }
}

static void gen6_check_mch_setup(struct drm_i915_private *dev_priv)
{
        uint32_t tmp;

        tmp = I915_READ(MCH_SSKPD);
        if ((tmp & MCH_SSKPD_WM0_MASK) != MCH_SSKPD_WM0_VAL)
                DRM_DEBUG_KMS("Wrong MCH_SSKPD value: 0x%08x This can cause underruns.\n",
                              tmp);
}

static void gen6_init_clock_gating(struct drm_i915_private *dev_priv)
{
        uint32_t dspclk_gate = ILK_VRHUNIT_CLOCK_GATE_DISABLE;

        I915_WRITE(ILK_DSPCLK_GATE_D, dspclk_gate);

        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_ELPIN_409_SELECT);

        /* WaDisableHiZPlanesWhenMSAAEnabled:snb */
        I915_WRITE(_3D_CHICKEN,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN_HIZ_PLANE_DISABLE_MSAA_4X_SNB));

        /* WaDisable_RenderCache_OperationalFlush:snb */
        I915_WRITE(CACHE_MODE_0, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        /*
         * BSpec recoomends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
         *
         * Note that PS/WM thread counts depend on the WIZ hashing
         * disable bit, which we don't touch here, but it's good
         * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN6_GT_MODE,
                   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));

        ilk_init_lp_watermarks(dev_priv);

        I915_WRITE(CACHE_MODE_0,
                   _MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));

        I915_WRITE(GEN6_UCGCTL1,
                   I915_READ(GEN6_UCGCTL1) |
                   GEN6_BLBUNIT_CLOCK_GATE_DISABLE |
                   GEN6_CSUNIT_CLOCK_GATE_DISABLE);

        /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock
         * gating disable must be set.  Failure to set it results in
         * flickering pixels due to Z write ordering failures after
         * some amount of runtime in the Mesa "fire" demo, and Unigine
         * Sanctuary and Tropics, and apparently anything else with
         * alpha test or pixel discard.
         *
         * According to the spec, bit 11 (RCCUNIT) must also be set,
         * but we didn't debug actual testcases to find it out.
         *
         * WaDisableRCCUnitClockGating:snb
         * WaDisableRCPBUnitClockGating:snb
         */
        I915_WRITE(GEN6_UCGCTL2,
                   GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
                   GEN6_RCCUNIT_CLOCK_GATE_DISABLE);

        /* WaStripsFansDisableFastClipPerformanceFix:snb */
        I915_WRITE(_3D_CHICKEN3,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN3_SF_DISABLE_FASTCLIP_CULL));

        /*
         * Bspec says:
         * "This bit must be set if 3DSTATE_CLIP clip mode is set to normal and
         * 3DSTATE_SF number of SF output attributes is more than 16."
         */
        I915_WRITE(_3D_CHICKEN3,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN3_SF_DISABLE_PIPELINED_ATTR_FETCH));

        /*
         * According to the spec the following bits should be
         * set in order to enable memory self-refresh and fbc:
         * The bit21 and bit22 of 0x42000
         * The bit21 and bit22 of 0x42004
         * The bit5 and bit7 of 0x42020
         * The bit14 of 0x70180
         * The bit14 of 0x71180
         *
         * WaFbcAsynchFlipDisableFbcQueue:snb
         */
        I915_WRITE(ILK_DISPLAY_CHICKEN1,
                   I915_READ(ILK_DISPLAY_CHICKEN1) |
                   ILK_FBCQ_DIS | ILK_PABSTRETCH_DIS);
        I915_WRITE(ILK_DISPLAY_CHICKEN2,
                   I915_READ(ILK_DISPLAY_CHICKEN2) |
                   ILK_DPARB_GATE | ILK_VSDPFD_FULL);
        I915_WRITE(ILK_DSPCLK_GATE_D,
                   I915_READ(ILK_DSPCLK_GATE_D) |
                   ILK_DPARBUNIT_CLOCK_GATE_ENABLE  |
                   ILK_DPFDUNIT_CLOCK_GATE_ENABLE);

        g4x_disable_trickle_feed(dev_priv);

        cpt_init_clock_gating(dev_priv);

        gen6_check_mch_setup(dev_priv);
}

static void gen7_setup_fixed_func_scheduler(struct drm_i915_private *dev_priv)
{
        uint32_t reg = I915_READ(GEN7_FF_THREAD_MODE);

        /*
         * WaVSThreadDispatchOverride:ivb,vlv
         *
         * This actually overrides the dispatch
         * mode for all thread types.
         */
        reg &= ~GEN7_FF_SCHED_MASK;
        reg |= GEN7_FF_TS_SCHED_HW;
        reg |= GEN7_FF_VS_SCHED_HW;
        reg |= GEN7_FF_DS_SCHED_HW;

        I915_WRITE(GEN7_FF_THREAD_MODE, reg);
}

static void lpt_init_clock_gating(struct drm_i915_private *dev_priv)
{
        /*
         * TODO: this bit should only be enabled when really needed, then
         * disabled when not needed anymore in order to save power.
         */
        if (HAS_PCH_LPT_LP(dev_priv))
                I915_WRITE(SOUTH_DSPCLK_GATE_D,
                           I915_READ(SOUTH_DSPCLK_GATE_D) |
                           PCH_LP_PARTITION_LEVEL_DISABLE);

        /* WADPOClockGatingDisable:hsw */
        I915_WRITE(TRANS_CHICKEN1(PIPE_A),
                   I915_READ(TRANS_CHICKEN1(PIPE_A)) |
                   TRANS_CHICKEN1_DP0UNIT_GC_DISABLE);
}

static void lpt_suspend_hw(struct drm_i915_private *dev_priv)
{
        if (HAS_PCH_LPT_LP(dev_priv)) {
                uint32_t val = I915_READ(SOUTH_DSPCLK_GATE_D);

                val &= ~PCH_LP_PARTITION_LEVEL_DISABLE;
                I915_WRITE(SOUTH_DSPCLK_GATE_D, val);
        }
}

static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
                                   int general_prio_credits,
                                   int high_prio_credits)
{
        u32 misccpctl;

        /* WaTempDisableDOPClkGating:bdw */
        misccpctl = I915_READ(GEN7_MISCCPCTL);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);

        I915_WRITE(GEN8_L3SQCREG1,
                   L3_GENERAL_PRIO_CREDITS(general_prio_credits) |
                   L3_HIGH_PRIO_CREDITS(high_prio_credits));

        /*
         * Wait at least 100 clocks before re-enabling clock gating.
         * See the definition of L3SQCREG1 in BSpec.
         */
        POSTING_READ(GEN8_L3SQCREG1);
        udelay(1);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl);
}

static void cnp_init_clock_gating(struct drm_i915_private *dev_priv)
{
        if (!HAS_PCH_CNP(dev_priv))
                return;

        /* Wa #1181 */
        I915_WRITE(SOUTH_DSPCLK_GATE_D, I915_READ(SOUTH_DSPCLK_GATE_D) |
                   CNP_PWM_CGE_GATING_DISABLE);
}

static void cnl_init_clock_gating(struct drm_i915_private *dev_priv)
{
        u32 val;
        cnp_init_clock_gating(dev_priv);

        /* This is not an Wa. Enable for better image quality */
        I915_WRITE(_3D_CHICKEN3,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE));

        /* WaEnableChickenDCPR:cnl */
        I915_WRITE(GEN8_CHICKEN_DCPR_1,
                   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);

        /* WaFbcWakeMemOn:cnl */
        I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
                   DISP_FBC_MEMORY_WAKE);

        /* WaSarbUnitClockGatingDisable:cnl (pre-prod) */
        if (IS_CNL_REVID(dev_priv, CNL_REVID_A0, CNL_REVID_B0))
                I915_WRITE(SLICE_UNIT_LEVEL_CLKGATE,
                           I915_READ(SLICE_UNIT_LEVEL_CLKGATE) |
                           SARBUNIT_CLKGATE_DIS);

        /* Display WA #1133: WaFbcSkipSegments:cnl */
        val = I915_READ(ILK_DPFC_CHICKEN);
        val &= ~GLK_SKIP_SEG_COUNT_MASK;
        val |= GLK_SKIP_SEG_EN | GLK_SKIP_SEG_COUNT(1);
        I915_WRITE(ILK_DPFC_CHICKEN, val);
}

static void cfl_init_clock_gating(struct drm_i915_private *dev_priv)
{
        cnp_init_clock_gating(dev_priv);
        gen9_init_clock_gating(dev_priv);

        /* WaFbcNukeOnHostModify:cfl */
        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
                   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
}

static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
{
        gen9_init_clock_gating(dev_priv);

        /* WaDisableSDEUnitClockGating:kbl */
        if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
                I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
                           GEN8_SDEUNIT_CLOCK_GATE_DISABLE);

        /* WaDisableGamClockGating:kbl */
        if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
                I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
                           GEN6_GAMUNIT_CLOCK_GATE_DISABLE);

        /* WaFbcNukeOnHostModify:kbl */
        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
                   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
}

static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
{
        gen9_init_clock_gating(dev_priv);

        /* WAC6entrylatency:skl */
        I915_WRITE(FBC_LLC_READ_CTRL, I915_READ(FBC_LLC_READ_CTRL) |
                   FBC_LLC_FULLY_OPEN);

        /* WaFbcNukeOnHostModify:skl */
        I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
                   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
}

static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
{
        enum pipe pipe;

        ilk_init_lp_watermarks(dev_priv);

        /* WaSwitchSolVfFArbitrationPriority:bdw */
        I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);

        /* WaPsrDPAMaskVBlankInSRD:bdw */
        I915_WRITE(CHICKEN_PAR1_1,
                   I915_READ(CHICKEN_PAR1_1) | DPA_MASK_VBLANK_SRD);

        /* WaPsrDPRSUnmaskVBlankInSRD:bdw */
        for_each_pipe(dev_priv, pipe) {
                I915_WRITE(CHICKEN_PIPESL_1(pipe),
                           I915_READ(CHICKEN_PIPESL_1(pipe)) |
                           BDW_DPRS_MASK_VBLANK_SRD);
        }

        /* WaVSRefCountFullforceMissDisable:bdw */
        /* WaDSRefCountFullforceMissDisable:bdw */
        I915_WRITE(GEN7_FF_THREAD_MODE,
                   I915_READ(GEN7_FF_THREAD_MODE) &
                   ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));

        I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
                   _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));

        /* WaDisableSDEUnitClockGating:bdw */
        I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
                   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);

        /* WaProgramL3SqcReg1Default:bdw */
        gen8_set_l3sqc_credits(dev_priv, 30, 2);

        /*
         * WaGttCachingOffByDefault:bdw
         * GTT cache may not work with big pages, so if those
         * are ever enabled GTT cache may need to be disabled.
         */
        I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL);

        /* WaKVMNotificationOnConfigChange:bdw */
        I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1)
                   | KVM_CONFIG_CHANGE_NOTIFICATION_SELECT);

        lpt_init_clock_gating(dev_priv);

        /* WaDisableDopClockGating:bdw
         *
         * Also see the CHICKEN2 write in bdw_init_workarounds() to disable DOP
         * clock gating.
         */
        I915_WRITE(GEN6_UCGCTL1,
                   I915_READ(GEN6_UCGCTL1) | GEN6_EU_TCUNIT_CLOCK_GATE_DISABLE);
}

static void hsw_init_clock_gating(struct drm_i915_private *dev_priv)
{
        ilk_init_lp_watermarks(dev_priv);

        /* L3 caching of data atomics doesn't work -- disable it. */
        I915_WRITE(HSW_SCRATCH1, HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE);
        I915_WRITE(HSW_ROW_CHICKEN3,
                   _MASKED_BIT_ENABLE(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE));

        /* This is required by WaCatErrorRejectionIssue:hsw */
        I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
                        I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
                        GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);

        /* WaVSRefCountFullforceMissDisable:hsw */
        I915_WRITE(GEN7_FF_THREAD_MODE,
                   I915_READ(GEN7_FF_THREAD_MODE) & ~GEN7_FF_VS_REF_CNT_FFME);

        /* WaDisable_RenderCache_OperationalFlush:hsw */
        I915_WRITE(CACHE_MODE_0_GEN7, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        /* enable HiZ Raw Stall Optimization */
        I915_WRITE(CACHE_MODE_0_GEN7,
                   _MASKED_BIT_DISABLE(HIZ_RAW_STALL_OPT_DISABLE));

        /* WaDisable4x2SubspanOptimization:hsw */
        I915_WRITE(CACHE_MODE_1,
                   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));

        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
         *
         * Note that PS/WM thread counts depend on the WIZ hashing
         * disable bit, which we don't touch here, but it's good
         * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));

        /* WaSampleCChickenBitEnable:hsw */
        I915_WRITE(HALF_SLICE_CHICKEN3,
                   _MASKED_BIT_ENABLE(HSW_SAMPLE_C_PERFORMANCE));

        /* WaSwitchSolVfFArbitrationPriority:hsw */
        I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);

        /* WaRsPkgCStateDisplayPMReq:hsw */
        I915_WRITE(CHICKEN_PAR1_1,
                   I915_READ(CHICKEN_PAR1_1) | FORCE_ARB_IDLE_PLANES);

        lpt_init_clock_gating(dev_priv);
}

static void ivb_init_clock_gating(struct drm_i915_private *dev_priv)
{
        uint32_t snpcr;

        ilk_init_lp_watermarks(dev_priv);

        I915_WRITE(ILK_DSPCLK_GATE_D, ILK_VRHUNIT_CLOCK_GATE_DISABLE);

        /* WaDisableEarlyCull:ivb */
        I915_WRITE(_3D_CHICKEN3,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN_SF_DISABLE_OBJEND_CULL));

        /* WaDisableBackToBackFlipFix:ivb */
        I915_WRITE(IVB_CHICKEN3,
                   CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
                   CHICKEN3_DGMG_DONE_FIX_DISABLE);

        /* WaDisablePSDDualDispatchEnable:ivb */
        if (IS_IVB_GT1(dev_priv))
                I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
                           _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));

        /* WaDisable_RenderCache_OperationalFlush:ivb */
        I915_WRITE(CACHE_MODE_0_GEN7, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        /* Apply the WaDisableRHWOOptimizationForRenderHang:ivb workaround. */
        I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
                   GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);

        /* WaApplyL3ControlAndL3ChickenMode:ivb */
        I915_WRITE(GEN7_L3CNTLREG1,
                        GEN7_WA_FOR_GEN7_L3_CONTROL);
        I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER,
                   GEN7_WA_L3_CHICKEN_MODE);
        if (IS_IVB_GT1(dev_priv))
                I915_WRITE(GEN7_ROW_CHICKEN2,
                           _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
        else {
                /* must write both registers */
                I915_WRITE(GEN7_ROW_CHICKEN2,
                           _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
                I915_WRITE(GEN7_ROW_CHICKEN2_GT2,
                           _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
        }

        /* WaForceL3Serialization:ivb */
        I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
                   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);

        /*
         * According to the spec, bit 13 (RCZUNIT) must be set on IVB.
         * This implements the WaDisableRCZUnitClockGating:ivb workaround.
         */
        I915_WRITE(GEN6_UCGCTL2,
                   GEN6_RCZUNIT_CLOCK_GATE_DISABLE);

        /* This is required by WaCatErrorRejectionIssue:ivb */
        I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
                        I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
                        GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);

        g4x_disable_trickle_feed(dev_priv);

        gen7_setup_fixed_func_scheduler(dev_priv);

        if (0) { /* causes HiZ corruption on ivb:gt1 */
                /* enable HiZ Raw Stall Optimization */
                I915_WRITE(CACHE_MODE_0_GEN7,
                           _MASKED_BIT_DISABLE(HIZ_RAW_STALL_OPT_DISABLE));
        }

        /* WaDisable4x2SubspanOptimization:ivb */
        I915_WRITE(CACHE_MODE_1,
                   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));

        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
         *
         * Note that PS/WM thread counts depend on the WIZ hashing
         * disable bit, which we don't touch here, but it's good
         * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));

        snpcr = I915_READ(GEN6_MBCUNIT_SNPCR);
        snpcr &= ~GEN6_MBC_SNPCR_MASK;
        snpcr |= GEN6_MBC_SNPCR_MED;
        I915_WRITE(GEN6_MBCUNIT_SNPCR, snpcr);

        if (!HAS_PCH_NOP(dev_priv))
                cpt_init_clock_gating(dev_priv);

        gen6_check_mch_setup(dev_priv);
}

static void vlv_init_clock_gating(struct drm_i915_private *dev_priv)
{
        /* WaDisableEarlyCull:vlv */
        I915_WRITE(_3D_CHICKEN3,
                   _MASKED_BIT_ENABLE(_3D_CHICKEN_SF_DISABLE_OBJEND_CULL));

        /* WaDisableBackToBackFlipFix:vlv */
        I915_WRITE(IVB_CHICKEN3,
                   CHICKEN3_DGMG_REQ_OUT_FIX_DISABLE |
                   CHICKEN3_DGMG_DONE_FIX_DISABLE);

        /* WaPsdDispatchEnable:vlv */
        /* WaDisablePSDDualDispatchEnable:vlv */
        I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
                   _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP |
                                      GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));

        /* WaDisable_RenderCache_OperationalFlush:vlv */
        I915_WRITE(CACHE_MODE_0_GEN7, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        /* WaForceL3Serialization:vlv */
        I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
                   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);

        /* WaDisableDopClockGating:vlv */
        I915_WRITE(GEN7_ROW_CHICKEN2,
                   _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));

        /* This is required by WaCatErrorRejectionIssue:vlv */
        I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
                   I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
                   GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);

        gen7_setup_fixed_func_scheduler(dev_priv);

        /*
         * According to the spec, bit 13 (RCZUNIT) must be set on IVB.
         * This implements the WaDisableRCZUnitClockGating:vlv workaround.
         */
        I915_WRITE(GEN6_UCGCTL2,
                   GEN6_RCZUNIT_CLOCK_GATE_DISABLE);

        /* WaDisableL3Bank2xClockGate:vlv
         * Disabling L3 clock gating- MMIO 940c[25] = 1
         * Set bit 25, to disable L3_BANK_2x_CLK_GATING */
        I915_WRITE(GEN7_UCGCTL4,
                   I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);

        /*
         * BSpec says this must be set, even though
         * WaDisable4x2SubspanOptimization isn't listed for VLV.
         */
        I915_WRITE(CACHE_MODE_1,
                   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));

        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
         *
         * Note that PS/WM thread counts depend on the WIZ hashing
         * disable bit, which we don't touch here, but it's good
         * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));

        /*
         * WaIncreaseL3CreditsForVLVB0:vlv
         * This is the hardware default actually.
         */
        I915_WRITE(GEN7_L3SQCREG1, VLV_B0_WA_L3SQCREG1_VALUE);

        /*
         * WaDisableVLVClockGating_VBIIssue:vlv
         * Disable clock gating on th GCFG unit to prevent a delay
         * in the reporting of vblank events.
         */
        I915_WRITE(VLV_GUNIT_CLOCK_GATE, GCFG_DIS);
}

static void chv_init_clock_gating(struct drm_i915_private *dev_priv)
{
        /* WaVSRefCountFullforceMissDisable:chv */
        /* WaDSRefCountFullforceMissDisable:chv */
        I915_WRITE(GEN7_FF_THREAD_MODE,
                   I915_READ(GEN7_FF_THREAD_MODE) &
                   ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));

        /* WaDisableSemaphoreAndSyncFlipWait:chv */
        I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
                   _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));

        /* WaDisableCSUnitClockGating:chv */
        I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
                   GEN6_CSUNIT_CLOCK_GATE_DISABLE);

        /* WaDisableSDEUnitClockGating:chv */
        I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
                   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);

        /*
         * WaProgramL3SqcReg1Default:chv
         * See gfxspecs/Related Documents/Performance Guide/
         * LSQC Setting Recommendations.
         */
        gen8_set_l3sqc_credits(dev_priv, 38, 2);

        /*
         * GTT cache may not work with big pages, so if those
         * are ever enabled GTT cache may need to be disabled.
         */
        I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL);
}

static void g4x_init_clock_gating(struct drm_i915_private *dev_priv)
{
        uint32_t dspclk_gate;

        I915_WRITE(RENCLK_GATE_D1, 0);
        I915_WRITE(RENCLK_GATE_D2, VF_UNIT_CLOCK_GATE_DISABLE |
                   GS_UNIT_CLOCK_GATE_DISABLE |
                   CL_UNIT_CLOCK_GATE_DISABLE);
        I915_WRITE(RAMCLK_GATE_D, 0);
        dspclk_gate = VRHUNIT_CLOCK_GATE_DISABLE |
                OVRUNIT_CLOCK_GATE_DISABLE |
                OVCUNIT_CLOCK_GATE_DISABLE;
        if (IS_GM45(dev_priv))
                dspclk_gate |= DSSUNIT_CLOCK_GATE_DISABLE;
        I915_WRITE(DSPCLK_GATE_D, dspclk_gate);

        /* WaDisableRenderCachePipelinedFlush */
        I915_WRITE(CACHE_MODE_0,
                   _MASKED_BIT_ENABLE(CM0_PIPELINED_RENDER_FLUSH_DISABLE));

        /* WaDisable_RenderCache_OperationalFlush:g4x */
        I915_WRITE(CACHE_MODE_0, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));

        g4x_disable_trickle_feed(dev_priv);
}

static void i965gm_init_clock_gating(struct drm_i915_private *dev_priv)
{
        I915_WRITE(RENCLK_GATE_D1, I965_RCC_CLOCK_GATE_DISABLE);
        I915_WRITE(RENCLK_GATE_D2, 0);
        I915_WRITE(DSPCLK_GATE_D, 0);
        I915_WRITE(RAMCLK_GATE_D, 0);
        I915_WRITE16(DEUC, 0);
        I915_WRITE(MI_ARB_STATE,
                   _MASKED_BIT_ENABLE(MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE));

        /* WaDisable_RenderCache_OperationalFlush:gen4 */
        I915_WRITE(CACHE_MODE_0, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));
}

static void i965g_init_clock_gating(struct drm_i915_private *dev_priv)
{
        I915_WRITE(RENCLK_GATE_D1, I965_RCZ_CLOCK_GATE_DISABLE |
                   I965_RCC_CLOCK_GATE_DISABLE |
                   I965_RCPB_CLOCK_GATE_DISABLE |
                   I965_ISC_CLOCK_GATE_DISABLE |
                   I965_FBC_CLOCK_GATE_DISABLE);
        I915_WRITE(RENCLK_GATE_D2, 0);
        I915_WRITE(MI_ARB_STATE,
                   _MASKED_BIT_ENABLE(MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE));

        /* WaDisable_RenderCache_OperationalFlush:gen4 */
        I915_WRITE(CACHE_MODE_0, _MASKED_BIT_DISABLE(RC_OP_FLUSH_ENABLE));
}

static void gen3_init_clock_gating(struct drm_i915_private *dev_priv)
{
        u32 dstate = I915_READ(D_STATE);

        dstate |= DSTATE_PLL_D3_OFF | DSTATE_GFX_CLOCK_GATING |
                DSTATE_DOT_CLOCK_GATING;
        I915_WRITE(D_STATE, dstate);

        if (IS_PINEVIEW(dev_priv))
                I915_WRITE(ECOSKPD, _MASKED_BIT_ENABLE(ECO_GATING_CX_ONLY));

        /* IIR "flip pending" means done if this bit is set */
        I915_WRITE(ECOSKPD, _MASKED_BIT_DISABLE(ECO_FLIP_DONE));

        /* interrupts should cause a wake up from C3 */
        I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_AGPBUSY_INT_EN));

        /* On GEN3 we really need to make sure the ARB C3 LP bit is set */
        I915_WRITE(MI_ARB_STATE, _MASKED_BIT_ENABLE(MI_ARB_C3_LP_WRITE_ENABLE));

        I915_WRITE(MI_ARB_STATE,
                   _MASKED_BIT_ENABLE(MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE));
}

static void i85x_init_clock_gating(struct drm_i915_private *dev_priv)
{
        I915_WRITE(RENCLK_GATE_D1, SV_CLOCK_GATE_DISABLE);

        /* interrupts should cause a wake up from C3 */
        I915_WRITE(MI_STATE, _MASKED_BIT_ENABLE(MI_AGPBUSY_INT_EN) |
                   _MASKED_BIT_DISABLE(MI_AGPBUSY_830_MODE));

        I915_WRITE(MEM_MODE,
                   _MASKED_BIT_ENABLE(MEM_DISPLAY_TRICKLE_FEED_DISABLE));
}

static void i830_init_clock_gating(struct drm_i915_private *dev_priv)
{
        I915_WRITE(MEM_MODE,
                   _MASKED_BIT_ENABLE(MEM_DISPLAY_A_TRICKLE_FEED_DISABLE) |
                   _MASKED_BIT_ENABLE(MEM_DISPLAY_B_TRICKLE_FEED_DISABLE));
}

void intel_init_clock_gating(struct drm_i915_private *dev_priv)
{
        dev_priv->display.init_clock_gating(dev_priv);
}

void intel_suspend_hw(struct drm_i915_private *dev_priv)
{
        if (HAS_PCH_LPT(dev_priv))
                lpt_suspend_hw(dev_priv);
}

static void nop_init_clock_gating(struct drm_i915_private *dev_priv)
{
        DRM_DEBUG_KMS("No clock gating settings or workarounds applied.\n");
}

/**
 * intel_init_clock_gating_hooks - setup the clock gating hooks
 * @dev_priv: device private
 *
 * Setup the hooks that configure which clocks of a given platform can be
 * gated and also apply various GT and display specific workarounds for these
 * platforms. Note that some GT specific workarounds are applied separately
 * when GPU contexts or batchbuffers start their execution.
 */
void intel_init_clock_gating_hooks(struct drm_i915_private *dev_priv)
{
        if (IS_CANNONLAKE(dev_priv))
                dev_priv->display.init_clock_gating = cnl_init_clock_gating;
        else if (IS_COFFEELAKE(dev_priv))
                dev_priv->display.init_clock_gating = cfl_init_clock_gating;
        else if (IS_SKYLAKE(dev_priv))
                dev_priv->display.init_clock_gating = skl_init_clock_gating;
        else if (IS_KABYLAKE(dev_priv))
                dev_priv->display.init_clock_gating = kbl_init_clock_gating;
        else if (IS_BROXTON(dev_priv))
                dev_priv->display.init_clock_gating = bxt_init_clock_gating;
        else if (IS_GEMINILAKE(dev_priv))
                dev_priv->display.init_clock_gating = glk_init_clock_gating;
        else if (IS_BROADWELL(dev_priv))
                dev_priv->display.init_clock_gating = bdw_init_clock_gating;
        else if (IS_CHERRYVIEW(dev_priv))
                dev_priv->display.init_clock_gating = chv_init_clock_gating;
        else if (IS_HASWELL(dev_priv))
                dev_priv->display.init_clock_gating = hsw_init_clock_gating;
        else if (IS_IVYBRIDGE(dev_priv))
                dev_priv->display.init_clock_gating = ivb_init_clock_gating;
        else if (IS_VALLEYVIEW(dev_priv))
                dev_priv->display.init_clock_gating = vlv_init_clock_gating;
        else if (IS_GEN6(dev_priv))
                dev_priv->display.init_clock_gating = gen6_init_clock_gating;
        else if (IS_GEN5(dev_priv))
                dev_priv->display.init_clock_gating = ilk_init_clock_gating;
        else if (IS_G4X(dev_priv))
                dev_priv->display.init_clock_gating = g4x_init_clock_gating;
        else if (IS_I965GM(dev_priv))
                dev_priv->display.init_clock_gating = i965gm_init_clock_gating;
        else if (IS_I965G(dev_priv))
                dev_priv->display.init_clock_gating = i965g_init_clock_gating;
        else if (IS_GEN3(dev_priv))
                dev_priv->display.init_clock_gating = gen3_init_clock_gating;
        else if (IS_I85X(dev_priv) || IS_I865G(dev_priv))
                dev_priv->display.init_clock_gating = i85x_init_clock_gating;
        else if (IS_GEN2(dev_priv))
                dev_priv->display.init_clock_gating = i830_init_clock_gating;
        else {
                MISSING_CASE(INTEL_DEVID(dev_priv));
                dev_priv->display.init_clock_gating = nop_init_clock_gating;
        }
}

/* Set up chip specific power management-related functions */
void intel_init_pm(struct drm_i915_private *dev_priv)
{
        intel_fbc_init(dev_priv);

        /* For cxsr */
        if (IS_PINEVIEW(dev_priv))
                i915_pineview_get_mem_freq(dev_priv);
        else if (IS_GEN5(dev_priv))
                i915_ironlake_get_mem_freq(dev_priv);

        /* For FIFO watermark updates */
        if (INTEL_GEN(dev_priv) >= 9) {
                skl_setup_wm_latency(dev_priv);
                dev_priv->display.initial_watermarks = skl_initial_wm;
                dev_priv->display.atomic_update_watermarks = skl_atomic_update_crtc_wm;
                dev_priv->display.compute_global_watermarks = skl_compute_wm;
        } else if (HAS_PCH_SPLIT(dev_priv)) {
                ilk_setup_wm_latency(dev_priv);

                if ((IS_GEN5(dev_priv) && dev_priv->wm.pri_latency[1] &&
                     dev_priv->wm.spr_latency[1] && dev_priv->wm.cur_latency[1]) ||
                    (!IS_GEN5(dev_priv) && dev_priv->wm.pri_latency[0] &&
                     dev_priv->wm.spr_latency[0] && dev_priv->wm.cur_latency[0])) {
                        dev_priv->display.compute_pipe_wm = ilk_compute_pipe_wm;
                        dev_priv->display.compute_intermediate_wm =
                                ilk_compute_intermediate_wm;
                        dev_priv->display.initial_watermarks =
                                ilk_initial_watermarks;
                        dev_priv->display.optimize_watermarks =
                                ilk_optimize_watermarks;
                } else {
                        DRM_DEBUG_KMS("Failed to read display plane latency. "
                                      "Disable CxSR\n");
                }
        } else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
                vlv_setup_wm_latency(dev_priv);
                dev_priv->display.compute_pipe_wm = vlv_compute_pipe_wm;
                dev_priv->display.compute_intermediate_wm = vlv_compute_intermediate_wm;
                dev_priv->display.initial_watermarks = vlv_initial_watermarks;
                dev_priv->display.optimize_watermarks = vlv_optimize_watermarks;
                dev_priv->display.atomic_update_watermarks = vlv_atomic_update_fifo;
        } else if (IS_G4X(dev_priv)) {
                g4x_setup_wm_latency(dev_priv);
                dev_priv->display.compute_pipe_wm = g4x_compute_pipe_wm;
                dev_priv->display.compute_intermediate_wm = g4x_compute_intermediate_wm;
                dev_priv->display.initial_watermarks = g4x_initial_watermarks;
                dev_priv->display.optimize_watermarks = g4x_optimize_watermarks;
        } else if (IS_PINEVIEW(dev_priv)) {
                if (!intel_get_cxsr_latency(IS_PINEVIEW_G(dev_priv),
                                            dev_priv->is_ddr3,
                                            dev_priv->fsb_freq,
                                            dev_priv->mem_freq)) {
                        DRM_INFO("failed to find known CxSR latency "
                                 "(found ddr%s fsb freq %d, mem freq %d), "
                                 "disabling CxSR\n",
                                 (dev_priv->is_ddr3 == 1) ? "3" : "2",
                                 dev_priv->fsb_freq, dev_priv->mem_freq);
                        /* Disable CxSR and never update its watermark again */
                        intel_set_memory_cxsr(dev_priv, false);
                        dev_priv->display.update_wm = NULL;
                } else
                        dev_priv->display.update_wm = pineview_update_wm;
        } else if (IS_GEN4(dev_priv)) {
                dev_priv->display.update_wm = i965_update_wm;
        } else if (IS_GEN3(dev_priv)) {
                dev_priv->display.update_wm = i9xx_update_wm;
                dev_priv->display.get_fifo_size = i9xx_get_fifo_size;
        } else if (IS_GEN2(dev_priv)) {
                if (INTEL_INFO(dev_priv)->num_pipes == 1) {
                        dev_priv->display.update_wm = i845_update_wm;
                        dev_priv->display.get_fifo_size = i845_get_fifo_size;
                } else {
                        dev_priv->display.update_wm = i9xx_update_wm;
                        dev_priv->display.get_fifo_size = i830_get_fifo_size;
                }
        } else {
                DRM_ERROR("unexpected fall-through in intel_init_pm\n");
        }
}

static inline int gen6_check_mailbox_status(struct drm_i915_private *dev_priv)
{
        uint32_t flags =
                I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_ERROR_MASK;

        switch (flags) {
        case GEN6_PCODE_SUCCESS:
                return 0;
        case GEN6_PCODE_UNIMPLEMENTED_CMD:
                return -ENODEV;
        case GEN6_PCODE_ILLEGAL_CMD:
                return -ENXIO;
        case GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
        case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
                return -EOVERFLOW;
        case GEN6_PCODE_TIMEOUT:
                return -ETIMEDOUT;
        default:
                MISSING_CASE(flags);
                return 0;
        }
}

static inline int gen7_check_mailbox_status(struct drm_i915_private *dev_priv)
{
        uint32_t flags =
                I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_ERROR_MASK;

        switch (flags) {
        case GEN6_PCODE_SUCCESS:
                return 0;
        case GEN6_PCODE_ILLEGAL_CMD:
                return -ENXIO;
        case GEN7_PCODE_TIMEOUT:
                return -ETIMEDOUT;
        case GEN7_PCODE_ILLEGAL_DATA:
                return -EINVAL;
        case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
                return -EOVERFLOW;
        default:
                MISSING_CASE(flags);
                return 0;
        }
}

int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u32 mbox, u32 *val)
{
        int status;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        /* GEN6_PCODE_* are outside of the forcewake domain, we can
         * use te fw I915_READ variants to reduce the amount of work
         * required when reading/writing.
         */

        if (I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) {
                DRM_DEBUG_DRIVER("warning: pcode (read from mbox %x) mailbox access failed for %ps\n",
                                 mbox, __builtin_return_address(0));
                return -EAGAIN;
        }

        I915_WRITE_FW(GEN6_PCODE_DATA, *val);
        I915_WRITE_FW(GEN6_PCODE_DATA1, 0);
        I915_WRITE_FW(GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | mbox);

        if (__intel_wait_for_register_fw(dev_priv,
                                         GEN6_PCODE_MAILBOX, GEN6_PCODE_READY, 0,
                                         500, 0, NULL)) {
                DRM_ERROR("timeout waiting for pcode read (from mbox %x) to finish for %ps\n",
                          mbox, __builtin_return_address(0));
                return -ETIMEDOUT;
        }

        *val = I915_READ_FW(GEN6_PCODE_DATA);
        I915_WRITE_FW(GEN6_PCODE_DATA, 0);

        if (INTEL_GEN(dev_priv) > 6)
                status = gen7_check_mailbox_status(dev_priv);
        else
                status = gen6_check_mailbox_status(dev_priv);

        if (status) {
                DRM_DEBUG_DRIVER("warning: pcode (read from mbox %x) mailbox access failed for %ps: %d\n",
                                 mbox, __builtin_return_address(0), status);
                return status;
        }

        return 0;
}

int sandybridge_pcode_write(struct drm_i915_private *dev_priv,
                            u32 mbox, u32 val)
{
        int status;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

        /* GEN6_PCODE_* are outside of the forcewake domain, we can
         * use te fw I915_READ variants to reduce the amount of work
         * required when reading/writing.
         */

        if (I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY) {
                DRM_DEBUG_DRIVER("warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps\n",
                                 val, mbox, __builtin_return_address(0));
                return -EAGAIN;
        }

        I915_WRITE_FW(GEN6_PCODE_DATA, val);
        I915_WRITE_FW(GEN6_PCODE_DATA1, 0);
        I915_WRITE_FW(GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | mbox);

        if (__intel_wait_for_register_fw(dev_priv,
                                         GEN6_PCODE_MAILBOX, GEN6_PCODE_READY, 0,
                                         500, 0, NULL)) {
                DRM_ERROR("timeout waiting for pcode write of 0x%08x to mbox %x to finish for %ps\n",
                          val, mbox, __builtin_return_address(0));
                return -ETIMEDOUT;
        }

        I915_WRITE_FW(GEN6_PCODE_DATA, 0);

        if (INTEL_GEN(dev_priv) > 6)
                status = gen7_check_mailbox_status(dev_priv);
        else
                status = gen6_check_mailbox_status(dev_priv);

        if (status) {
                DRM_DEBUG_DRIVER("warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps: %d\n",
                                 val, mbox, __builtin_return_address(0), status);
                return status;
        }

        return 0;
}

static bool skl_pcode_try_request(struct drm_i915_private *dev_priv, u32 mbox,
                                  u32 request, u32 reply_mask, u32 reply,
                                  u32 *status)
{
        u32 val = request;

        *status = sandybridge_pcode_read(dev_priv, mbox, &val);

        return *status || ((val & reply_mask) == reply);
}

/**
 * skl_pcode_request - send PCODE request until acknowledgment
 * @dev_priv: device private
 * @mbox: PCODE mailbox ID the request is targeted for
 * @request: request ID
 * @reply_mask: mask used to check for request acknowledgment
 * @reply: value used to check for request acknowledgment
 * @timeout_base_ms: timeout for polling with preemption enabled
 *
 * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
 * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
 * The request is acknowledged once the PCODE reply dword equals @reply after
 * applying @reply_mask. Polling is first attempted with preemption enabled
 * for @timeout_base_ms and if this times out for another 50 ms with
 * preemption disabled.
 *
 * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
 * other error as reported by PCODE.
 */
int skl_pcode_request(struct drm_i915_private *dev_priv, u32 mbox, u32 request,
                      u32 reply_mask, u32 reply, int timeout_base_ms)
{
        u32 status;
        int ret;

        WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));

#define COND skl_pcode_try_request(dev_priv, mbox, request, reply_mask, reply, \
                                   &status)

        /*
         * Prime the PCODE by doing a request first. Normally it guarantees
         * that a subsequent request, at most @timeout_base_ms later, succeeds.
         * _wait_for() doesn't guarantee when its passed condition is evaluated
         * first, so send the first request explicitly.
         */
        if (COND) {
                ret = 0;
                goto out;
        }
        ret = _wait_for(COND, timeout_base_ms * 1000, 10);
        if (!ret)
                goto out;

        /*
         * The above can time out if the number of requests was low (2 in the
         * worst case) _and_ PCODE was busy for some reason even after a
         * (queued) request and @timeout_base_ms delay. As a workaround retry
         * the poll with preemption disabled to maximize the number of
         * requests. Increase the timeout from @timeout_base_ms to 50ms to
         * account for interrupts that could reduce the number of these
         * requests, and for any quirks of the PCODE firmware that delays
         * the request completion.
         */
        DRM_DEBUG_KMS("PCODE timeout, retrying with preemption disabled\n");
        WARN_ON_ONCE(timeout_base_ms > 3);
        preempt_disable();
        ret = wait_for_atomic(COND, 50);
        preempt_enable();

out:
        return ret ? ret : status;
#undef COND
}

static int byt_gpu_freq(struct drm_i915_private *dev_priv, int val)
{
        /*
         * N = val - 0xb7
         * Slow = Fast = GPLL ref * N
         */
        return DIV_ROUND_CLOSEST(dev_priv->rps.gpll_ref_freq * (val - 0xb7), 1000);
}

static int byt_freq_opcode(struct drm_i915_private *dev_priv, int val)
{
        return DIV_ROUND_CLOSEST(1000 * val, dev_priv->rps.gpll_ref_freq) + 0xb7;
}

static int chv_gpu_freq(struct drm_i915_private *dev_priv, int val)
{
        /*
         * N = val / 2
         * CU (slow) = CU2x (fast) / 2 = GPLL ref * N / 2
         */
        return DIV_ROUND_CLOSEST(dev_priv->rps.gpll_ref_freq * val, 2 * 2 * 1000);
}

static int chv_freq_opcode(struct drm_i915_private *dev_priv, int val)
{
        /* CHV needs even values */
        return DIV_ROUND_CLOSEST(2 * 1000 * val, dev_priv->rps.gpll_ref_freq) * 2;
}

int intel_gpu_freq(struct drm_i915_private *dev_priv, int val)
{
        if (INTEL_GEN(dev_priv) >= 9)
                return DIV_ROUND_CLOSEST(val * GT_FREQUENCY_MULTIPLIER,
                                         GEN9_FREQ_SCALER);
        else if (IS_CHERRYVIEW(dev_priv))
                return chv_gpu_freq(dev_priv, val);
        else if (IS_VALLEYVIEW(dev_priv))
                return byt_gpu_freq(dev_priv, val);
        else
                return val * GT_FREQUENCY_MULTIPLIER;
}

int intel_freq_opcode(struct drm_i915_private *dev_priv, int val)
{
        if (INTEL_GEN(dev_priv) >= 9)
                return DIV_ROUND_CLOSEST(val * GEN9_FREQ_SCALER,
                                         GT_FREQUENCY_MULTIPLIER);
        else if (IS_CHERRYVIEW(dev_priv))
                return chv_freq_opcode(dev_priv, val);
        else if (IS_VALLEYVIEW(dev_priv))
                return byt_freq_opcode(dev_priv, val);
        else
                return DIV_ROUND_CLOSEST(val, GT_FREQUENCY_MULTIPLIER);
}

void intel_pm_setup(struct drm_i915_private *dev_priv)
{
        mutex_init(&dev_priv->rps.hw_lock);

        INIT_DELAYED_WORK(&dev_priv->rps.autoenable_work,
                          __intel_autoenable_gt_powersave);
        atomic_set(&dev_priv->rps.num_waiters, 0);

        dev_priv->pm.suspended = false;
        atomic_set(&dev_priv->pm.wakeref_count, 0);
}

static u64 vlv_residency_raw(struct drm_i915_private *dev_priv,
                             const i915_reg_t reg)
{
        u32 lower, upper, tmp;
        int loop = 2;

        /* The register accessed do not need forcewake. We borrow
         * uncore lock to prevent concurrent access to range reg.
         */
        spin_lock_irq(&dev_priv->uncore.lock);

        /* vlv and chv residency counters are 40 bits in width.
         * With a control bit, we can choose between upper or lower
         * 32bit window into this counter.
         *
         * Although we always use the counter in high-range mode elsewhere,
         * userspace may attempt to read the value before rc6 is initialised,
         * before we have set the default VLV_COUNTER_CONTROL value. So always
         * set the high bit to be safe.
         */
        I915_WRITE_FW(VLV_COUNTER_CONTROL,
                      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
        upper = I915_READ_FW(reg);
        do {
                tmp = upper;

                I915_WRITE_FW(VLV_COUNTER_CONTROL,
                              _MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
                lower = I915_READ_FW(reg);

                I915_WRITE_FW(VLV_COUNTER_CONTROL,
                              _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
                upper = I915_READ_FW(reg);
        } while (upper != tmp && --loop);

        /* Everywhere else we always use VLV_COUNTER_CONTROL with the
         * VLV_COUNT_RANGE_HIGH bit set - so it is safe to leave it set
         * now.
         */

        spin_unlock_irq(&dev_priv->uncore.lock);

        return lower | (u64)upper << 8;
}

u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
                           const i915_reg_t reg)
{
        u64 time_hw, units, div;

        if (!intel_enable_rc6())
                return 0;

        intel_runtime_pm_get(dev_priv);

        /* On VLV and CHV, residency time is in CZ units rather than 1.28us */
        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
                units = 1000;
                div = dev_priv->czclk_freq;

                time_hw = vlv_residency_raw(dev_priv, reg);
        } else if (IS_GEN9_LP(dev_priv)) {
                units = 1000;
                div = 1200;             /* 833.33ns */

                time_hw = I915_READ(reg);
        } else {
                units = 128000; /* 1.28us */
                div = 100000;

                time_hw = I915_READ(reg);
        }

        intel_runtime_pm_put(dev_priv);
        return DIV_ROUND_UP_ULL(time_hw * units, div);
}