drm/i915: Update DRIVER_DATE to 20150928

[mirror_ubuntu-zesty-kernel.git] / drivers / gpu / drm / i915 / i915_irq.c

/* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
 */
/*
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/circ_buf.h>
#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_drv.h"

/**
 * DOC: interrupt handling
 *
 * These functions provide the basic support for enabling and disabling the
 * interrupt handling support. There's a lot more functionality in i915_irq.c
 * and related files, but that will be described in separate chapters.
 */

static const u32 hpd_ilk[HPD_NUM_PINS] = {
        [HPD_PORT_A] = DE_DP_A_HOTPLUG,
};

static const u32 hpd_ivb[HPD_NUM_PINS] = {
        [HPD_PORT_A] = DE_DP_A_HOTPLUG_IVB,
};

static const u32 hpd_bdw[HPD_NUM_PINS] = {
        [HPD_PORT_A] = GEN8_PORT_DP_A_HOTPLUG,
};

static const u32 hpd_ibx[HPD_NUM_PINS] = {
        [HPD_CRT] = SDE_CRT_HOTPLUG,
        [HPD_SDVO_B] = SDE_SDVOB_HOTPLUG,
        [HPD_PORT_B] = SDE_PORTB_HOTPLUG,
        [HPD_PORT_C] = SDE_PORTC_HOTPLUG,
        [HPD_PORT_D] = SDE_PORTD_HOTPLUG
};

static const u32 hpd_cpt[HPD_NUM_PINS] = {
        [HPD_CRT] = SDE_CRT_HOTPLUG_CPT,
        [HPD_SDVO_B] = SDE_SDVOB_HOTPLUG_CPT,
        [HPD_PORT_B] = SDE_PORTB_HOTPLUG_CPT,
        [HPD_PORT_C] = SDE_PORTC_HOTPLUG_CPT,
        [HPD_PORT_D] = SDE_PORTD_HOTPLUG_CPT
};

static const u32 hpd_spt[HPD_NUM_PINS] = {
        [HPD_PORT_A] = SDE_PORTA_HOTPLUG_SPT,
        [HPD_PORT_B] = SDE_PORTB_HOTPLUG_CPT,
        [HPD_PORT_C] = SDE_PORTC_HOTPLUG_CPT,
        [HPD_PORT_D] = SDE_PORTD_HOTPLUG_CPT,
        [HPD_PORT_E] = SDE_PORTE_HOTPLUG_SPT
};

static const u32 hpd_mask_i915[HPD_NUM_PINS] = {
        [HPD_CRT] = CRT_HOTPLUG_INT_EN,
        [HPD_SDVO_B] = SDVOB_HOTPLUG_INT_EN,
        [HPD_SDVO_C] = SDVOC_HOTPLUG_INT_EN,
        [HPD_PORT_B] = PORTB_HOTPLUG_INT_EN,
        [HPD_PORT_C] = PORTC_HOTPLUG_INT_EN,
        [HPD_PORT_D] = PORTD_HOTPLUG_INT_EN
};

static const u32 hpd_status_g4x[HPD_NUM_PINS] = {
        [HPD_CRT] = CRT_HOTPLUG_INT_STATUS,
        [HPD_SDVO_B] = SDVOB_HOTPLUG_INT_STATUS_G4X,
        [HPD_SDVO_C] = SDVOC_HOTPLUG_INT_STATUS_G4X,
        [HPD_PORT_B] = PORTB_HOTPLUG_INT_STATUS,
        [HPD_PORT_C] = PORTC_HOTPLUG_INT_STATUS,
        [HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
};

static const u32 hpd_status_i915[HPD_NUM_PINS] = {
        [HPD_CRT] = CRT_HOTPLUG_INT_STATUS,
        [HPD_SDVO_B] = SDVOB_HOTPLUG_INT_STATUS_I915,
        [HPD_SDVO_C] = SDVOC_HOTPLUG_INT_STATUS_I915,
        [HPD_PORT_B] = PORTB_HOTPLUG_INT_STATUS,
        [HPD_PORT_C] = PORTC_HOTPLUG_INT_STATUS,
        [HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
};

/* BXT hpd list */
static const u32 hpd_bxt[HPD_NUM_PINS] = {
        [HPD_PORT_A] = BXT_DE_PORT_HP_DDIA,
        [HPD_PORT_B] = BXT_DE_PORT_HP_DDIB,
        [HPD_PORT_C] = BXT_DE_PORT_HP_DDIC
};

/* IIR can theoretically queue up two events. Be paranoid. */
#define GEN8_IRQ_RESET_NDX(type, which) do { \
        I915_WRITE(GEN8_##type##_IMR(which), 0xffffffff); \
        POSTING_READ(GEN8_##type##_IMR(which)); \
        I915_WRITE(GEN8_##type##_IER(which), 0); \
        I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
        POSTING_READ(GEN8_##type##_IIR(which)); \
        I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
        POSTING_READ(GEN8_##type##_IIR(which)); \
} while (0)

#define GEN5_IRQ_RESET(type) do { \
        I915_WRITE(type##IMR, 0xffffffff); \
        POSTING_READ(type##IMR); \
        I915_WRITE(type##IER, 0); \
        I915_WRITE(type##IIR, 0xffffffff); \
        POSTING_READ(type##IIR); \
        I915_WRITE(type##IIR, 0xffffffff); \
        POSTING_READ(type##IIR); \
} while (0)

/*
 * We should clear IMR at preinstall/uninstall, and just check at postinstall.
 */
#define GEN5_ASSERT_IIR_IS_ZERO(reg) do { \
        u32 val = I915_READ(reg); \
        if (val) { \
                WARN(1, "Interrupt register 0x%x is not zero: 0x%08x\n", \
                     (reg), val); \
                I915_WRITE((reg), 0xffffffff); \
                POSTING_READ(reg); \
                I915_WRITE((reg), 0xffffffff); \
                POSTING_READ(reg); \
        } \
} while (0)

#define GEN8_IRQ_INIT_NDX(type, which, imr_val, ier_val) do { \
        GEN5_ASSERT_IIR_IS_ZERO(GEN8_##type##_IIR(which)); \
        I915_WRITE(GEN8_##type##_IER(which), (ier_val)); \
        I915_WRITE(GEN8_##type##_IMR(which), (imr_val)); \
        POSTING_READ(GEN8_##type##_IMR(which)); \
} while (0)

#define GEN5_IRQ_INIT(type, imr_val, ier_val) do { \
        GEN5_ASSERT_IIR_IS_ZERO(type##IIR); \
        I915_WRITE(type##IER, (ier_val)); \
        I915_WRITE(type##IMR, (imr_val)); \
        POSTING_READ(type##IMR); \
} while (0)

static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir);

/* For display hotplug interrupt */
static inline void
i915_hotplug_interrupt_update_locked(struct drm_i915_private *dev_priv,
                                     uint32_t mask,
                                     uint32_t bits)
{
        uint32_t val;

        assert_spin_locked(&dev_priv->irq_lock);
        WARN_ON(bits & ~mask);

        val = I915_READ(PORT_HOTPLUG_EN);
        val &= ~mask;
        val |= bits;
        I915_WRITE(PORT_HOTPLUG_EN, val);
}

/**
 * i915_hotplug_interrupt_update - update hotplug interrupt enable
 * @dev_priv: driver private
 * @mask: bits to update
 * @bits: bits to enable
 * NOTE: the HPD enable bits are modified both inside and outside
 * of an interrupt context. To avoid that read-modify-write cycles
 * interfer, these bits are protected by a spinlock. Since this
 * function is usually not called from a context where the lock is
 * held already, this function acquires the lock itself. A non-locking
 * version is also available.
 */
void i915_hotplug_interrupt_update(struct drm_i915_private *dev_priv,
                                   uint32_t mask,
                                   uint32_t bits)
{
        spin_lock_irq(&dev_priv->irq_lock);
        i915_hotplug_interrupt_update_locked(dev_priv, mask, bits);
        spin_unlock_irq(&dev_priv->irq_lock);
}

/**
 * ilk_update_display_irq - update DEIMR
 * @dev_priv: driver private
 * @interrupt_mask: mask of interrupt bits to update
 * @enabled_irq_mask: mask of interrupt bits to enable
 */
static void ilk_update_display_irq(struct drm_i915_private *dev_priv,
                                   uint32_t interrupt_mask,
                                   uint32_t enabled_irq_mask)
{
        uint32_t new_val;

        assert_spin_locked(&dev_priv->irq_lock);

        WARN_ON(enabled_irq_mask & ~interrupt_mask);

        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        new_val = dev_priv->irq_mask;
        new_val &= ~interrupt_mask;
        new_val |= (~enabled_irq_mask & interrupt_mask);

        if (new_val != dev_priv->irq_mask) {
                dev_priv->irq_mask = new_val;
                I915_WRITE(DEIMR, dev_priv->irq_mask);
                POSTING_READ(DEIMR);
        }
}

void
ironlake_enable_display_irq(struct drm_i915_private *dev_priv, u32 mask)
{
        ilk_update_display_irq(dev_priv, mask, mask);
}

void
ironlake_disable_display_irq(struct drm_i915_private *dev_priv, u32 mask)
{
        ilk_update_display_irq(dev_priv, mask, 0);
}

/**
 * ilk_update_gt_irq - update GTIMR
 * @dev_priv: driver private
 * @interrupt_mask: mask of interrupt bits to update
 * @enabled_irq_mask: mask of interrupt bits to enable
 */
static void ilk_update_gt_irq(struct drm_i915_private *dev_priv,
                              uint32_t interrupt_mask,
                              uint32_t enabled_irq_mask)
{
        assert_spin_locked(&dev_priv->irq_lock);

        WARN_ON(enabled_irq_mask & ~interrupt_mask);

        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        dev_priv->gt_irq_mask &= ~interrupt_mask;
        dev_priv->gt_irq_mask |= (~enabled_irq_mask & interrupt_mask);
        I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
        POSTING_READ(GTIMR);
}

void gen5_enable_gt_irq(struct drm_i915_private *dev_priv, uint32_t mask)
{
        ilk_update_gt_irq(dev_priv, mask, mask);
}

void gen5_disable_gt_irq(struct drm_i915_private *dev_priv, uint32_t mask)
{
        ilk_update_gt_irq(dev_priv, mask, 0);
}

static u32 gen6_pm_iir(struct drm_i915_private *dev_priv)
{
        return INTEL_INFO(dev_priv)->gen >= 8 ? GEN8_GT_IIR(2) : GEN6_PMIIR;
}

static u32 gen6_pm_imr(struct drm_i915_private *dev_priv)
{
        return INTEL_INFO(dev_priv)->gen >= 8 ? GEN8_GT_IMR(2) : GEN6_PMIMR;
}

static u32 gen6_pm_ier(struct drm_i915_private *dev_priv)
{
        return INTEL_INFO(dev_priv)->gen >= 8 ? GEN8_GT_IER(2) : GEN6_PMIER;
}

/**
  * snb_update_pm_irq - update GEN6_PMIMR
  * @dev_priv: driver private
  * @interrupt_mask: mask of interrupt bits to update
  * @enabled_irq_mask: mask of interrupt bits to enable
  */
static void snb_update_pm_irq(struct drm_i915_private *dev_priv,
                              uint32_t interrupt_mask,
                              uint32_t enabled_irq_mask)
{
        uint32_t new_val;

        WARN_ON(enabled_irq_mask & ~interrupt_mask);

        assert_spin_locked(&dev_priv->irq_lock);

        new_val = dev_priv->pm_irq_mask;
        new_val &= ~interrupt_mask;
        new_val |= (~enabled_irq_mask & interrupt_mask);

        if (new_val != dev_priv->pm_irq_mask) {
                dev_priv->pm_irq_mask = new_val;
                I915_WRITE(gen6_pm_imr(dev_priv), dev_priv->pm_irq_mask);
                POSTING_READ(gen6_pm_imr(dev_priv));
        }
}

void gen6_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
{
        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        snb_update_pm_irq(dev_priv, mask, mask);
}

static void __gen6_disable_pm_irq(struct drm_i915_private *dev_priv,
                                  uint32_t mask)
{
        snb_update_pm_irq(dev_priv, mask, 0);
}

void gen6_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
{
        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        __gen6_disable_pm_irq(dev_priv, mask);
}

void gen6_reset_rps_interrupts(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t reg = gen6_pm_iir(dev_priv);

        spin_lock_irq(&dev_priv->irq_lock);
        I915_WRITE(reg, dev_priv->pm_rps_events);
        I915_WRITE(reg, dev_priv->pm_rps_events);
        POSTING_READ(reg);
        dev_priv->rps.pm_iir = 0;
        spin_unlock_irq(&dev_priv->irq_lock);
}

void gen6_enable_rps_interrupts(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        spin_lock_irq(&dev_priv->irq_lock);

        WARN_ON(dev_priv->rps.pm_iir);
        WARN_ON(I915_READ(gen6_pm_iir(dev_priv)) & dev_priv->pm_rps_events);
        dev_priv->rps.interrupts_enabled = true;
        I915_WRITE(gen6_pm_ier(dev_priv), I915_READ(gen6_pm_ier(dev_priv)) |
                                dev_priv->pm_rps_events);
        gen6_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);

        spin_unlock_irq(&dev_priv->irq_lock);
}

u32 gen6_sanitize_rps_pm_mask(struct drm_i915_private *dev_priv, u32 mask)
{
        /*
         * SNB,IVB can while VLV,CHV may hard hang on looping batchbuffer
         * if GEN6_PM_UP_EI_EXPIRED is masked.
         *
         * TODO: verify if this can be reproduced on VLV,CHV.
         */
        if (INTEL_INFO(dev_priv)->gen <= 7 && !IS_HASWELL(dev_priv))
                mask &= ~GEN6_PM_RP_UP_EI_EXPIRED;

        if (INTEL_INFO(dev_priv)->gen >= 8)
                mask &= ~GEN8_PMINTR_REDIRECT_TO_NON_DISP;

        return mask;
}

void gen6_disable_rps_interrupts(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        spin_lock_irq(&dev_priv->irq_lock);
        dev_priv->rps.interrupts_enabled = false;
        spin_unlock_irq(&dev_priv->irq_lock);

        cancel_work_sync(&dev_priv->rps.work);

        spin_lock_irq(&dev_priv->irq_lock);

        I915_WRITE(GEN6_PMINTRMSK, gen6_sanitize_rps_pm_mask(dev_priv, ~0));

        __gen6_disable_pm_irq(dev_priv, dev_priv->pm_rps_events);
        I915_WRITE(gen6_pm_ier(dev_priv), I915_READ(gen6_pm_ier(dev_priv)) &
                                ~dev_priv->pm_rps_events);

        spin_unlock_irq(&dev_priv->irq_lock);

        synchronize_irq(dev->irq);
}

/**
  * bdw_update_port_irq - update DE port interrupt
  * @dev_priv: driver private
  * @interrupt_mask: mask of interrupt bits to update
  * @enabled_irq_mask: mask of interrupt bits to enable
  */
static void bdw_update_port_irq(struct drm_i915_private *dev_priv,
                                uint32_t interrupt_mask,
                                uint32_t enabled_irq_mask)
{
        uint32_t new_val;
        uint32_t old_val;

        assert_spin_locked(&dev_priv->irq_lock);

        WARN_ON(enabled_irq_mask & ~interrupt_mask);

        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        old_val = I915_READ(GEN8_DE_PORT_IMR);

        new_val = old_val;
        new_val &= ~interrupt_mask;
        new_val |= (~enabled_irq_mask & interrupt_mask);

        if (new_val != old_val) {
                I915_WRITE(GEN8_DE_PORT_IMR, new_val);
                POSTING_READ(GEN8_DE_PORT_IMR);
        }
}

/**
 * ibx_display_interrupt_update - update SDEIMR
 * @dev_priv: driver private
 * @interrupt_mask: mask of interrupt bits to update
 * @enabled_irq_mask: mask of interrupt bits to enable
 */
void ibx_display_interrupt_update(struct drm_i915_private *dev_priv,
                                  uint32_t interrupt_mask,
                                  uint32_t enabled_irq_mask)
{
        uint32_t sdeimr = I915_READ(SDEIMR);
        sdeimr &= ~interrupt_mask;
        sdeimr |= (~enabled_irq_mask & interrupt_mask);

        WARN_ON(enabled_irq_mask & ~interrupt_mask);

        assert_spin_locked(&dev_priv->irq_lock);

        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;

        I915_WRITE(SDEIMR, sdeimr);
        POSTING_READ(SDEIMR);
}

static void
__i915_enable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
                       u32 enable_mask, u32 status_mask)
{
        u32 reg = PIPESTAT(pipe);
        u32 pipestat = I915_READ(reg) & PIPESTAT_INT_ENABLE_MASK;

        assert_spin_locked(&dev_priv->irq_lock);
        WARN_ON(!intel_irqs_enabled(dev_priv));

        if (WARN_ONCE(enable_mask & ~PIPESTAT_INT_ENABLE_MASK ||
                      status_mask & ~PIPESTAT_INT_STATUS_MASK,
                      "pipe %c: enable_mask=0x%x, status_mask=0x%x\n",
                      pipe_name(pipe), enable_mask, status_mask))
                return;

        if ((pipestat & enable_mask) == enable_mask)
                return;

        dev_priv->pipestat_irq_mask[pipe] |= status_mask;

        /* Enable the interrupt, clear any pending status */
        pipestat |= enable_mask | status_mask;
        I915_WRITE(reg, pipestat);
        POSTING_READ(reg);
}

static void
__i915_disable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
                        u32 enable_mask, u32 status_mask)
{
        u32 reg = PIPESTAT(pipe);
        u32 pipestat = I915_READ(reg) & PIPESTAT_INT_ENABLE_MASK;

        assert_spin_locked(&dev_priv->irq_lock);
        WARN_ON(!intel_irqs_enabled(dev_priv));

        if (WARN_ONCE(enable_mask & ~PIPESTAT_INT_ENABLE_MASK ||
                      status_mask & ~PIPESTAT_INT_STATUS_MASK,
                      "pipe %c: enable_mask=0x%x, status_mask=0x%x\n",
                      pipe_name(pipe), enable_mask, status_mask))
                return;

        if ((pipestat & enable_mask) == 0)
                return;

        dev_priv->pipestat_irq_mask[pipe] &= ~status_mask;

        pipestat &= ~enable_mask;
        I915_WRITE(reg, pipestat);
        POSTING_READ(reg);
}

static u32 vlv_get_pipestat_enable_mask(struct drm_device *dev, u32 status_mask)
{
        u32 enable_mask = status_mask << 16;

        /*
         * On pipe A we don't support the PSR interrupt yet,
         * on pipe B and C the same bit MBZ.
         */
        if (WARN_ON_ONCE(status_mask & PIPE_A_PSR_STATUS_VLV))
                return 0;
        /*
         * On pipe B and C we don't support the PSR interrupt yet, on pipe
         * A the same bit is for perf counters which we don't use either.
         */
        if (WARN_ON_ONCE(status_mask & PIPE_B_PSR_STATUS_VLV))
                return 0;

        enable_mask &= ~(PIPE_FIFO_UNDERRUN_STATUS |
                         SPRITE0_FLIP_DONE_INT_EN_VLV |
                         SPRITE1_FLIP_DONE_INT_EN_VLV);
        if (status_mask & SPRITE0_FLIP_DONE_INT_STATUS_VLV)
                enable_mask |= SPRITE0_FLIP_DONE_INT_EN_VLV;
        if (status_mask & SPRITE1_FLIP_DONE_INT_STATUS_VLV)
                enable_mask |= SPRITE1_FLIP_DONE_INT_EN_VLV;

        return enable_mask;
}

void
i915_enable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
                     u32 status_mask)
{
        u32 enable_mask;

        if (IS_VALLEYVIEW(dev_priv->dev))
                enable_mask = vlv_get_pipestat_enable_mask(dev_priv->dev,
                                                           status_mask);
        else
                enable_mask = status_mask << 16;
        __i915_enable_pipestat(dev_priv, pipe, enable_mask, status_mask);
}

void
i915_disable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
                      u32 status_mask)
{
        u32 enable_mask;

        if (IS_VALLEYVIEW(dev_priv->dev))
                enable_mask = vlv_get_pipestat_enable_mask(dev_priv->dev,
                                                           status_mask);
        else
                enable_mask = status_mask << 16;
        __i915_disable_pipestat(dev_priv, pipe, enable_mask, status_mask);
}

/**
 * i915_enable_asle_pipestat - enable ASLE pipestat for OpRegion
 */
static void i915_enable_asle_pipestat(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv->opregion.asle || !IS_MOBILE(dev))
                return;

        spin_lock_irq(&dev_priv->irq_lock);

        i915_enable_pipestat(dev_priv, PIPE_B, PIPE_LEGACY_BLC_EVENT_STATUS);
        if (INTEL_INFO(dev)->gen >= 4)
                i915_enable_pipestat(dev_priv, PIPE_A,
                                     PIPE_LEGACY_BLC_EVENT_STATUS);

        spin_unlock_irq(&dev_priv->irq_lock);
}

/*
 * This timing diagram depicts the video signal in and
 * around the vertical blanking period.
 *
 * Assumptions about the fictitious mode used in this example:
 *  vblank_start >= 3
 *  vsync_start = vblank_start + 1
 *  vsync_end = vblank_start + 2
 *  vtotal = vblank_start + 3
 *
 *           start of vblank:
 *           latch double buffered registers
 *           increment frame counter (ctg+)
 *           generate start of vblank interrupt (gen4+)
 *           |
 *           |          frame start:
 *           |          generate frame start interrupt (aka. vblank interrupt) (gmch)
 *           |          may be shifted forward 1-3 extra lines via PIPECONF
 *           |          |
 *           |          |  start of vsync:
 *           |          |  generate vsync interrupt
 *           |          |  |
 * ___xxxx___    ___xxxx___    ___xxxx___    ___xxxx___    ___xxxx___    ___xxxx
 *       .   \hs/   .      \hs/          \hs/          \hs/   .      \hs/
 * ----va---> <-----------------vb--------------------> <--------va-------------
 *       |          |       <----vs----->                     |
 * -vbs-----> <---vbs+1---> <---vbs+2---> <-----0-----> <-----1-----> <-----2--- (scanline counter gen2)
 * -vbs-2---> <---vbs-1---> <---vbs-----> <---vbs+1---> <---vbs+2---> <-----0--- (scanline counter gen3+)
 * -vbs-2---> <---vbs-2---> <---vbs-1---> <---vbs-----> <---vbs+1---> <---vbs+2- (scanline counter hsw+ hdmi)
 *       |          |                                         |
 *       last visible pixel                                   first visible pixel
 *                  |                                         increment frame counter (gen3/4)
 *                  pixel counter = vblank_start * htotal     pixel counter = 0 (gen3/4)
 *
 * x  = horizontal active
 * _  = horizontal blanking
 * hs = horizontal sync
 * va = vertical active
 * vb = vertical blanking
 * vs = vertical sync
 * vbs = vblank_start (number)
 *
 * Summary:
 * - most events happen at the start of horizontal sync
 * - frame start happens at the start of horizontal blank, 1-4 lines
 *   (depending on PIPECONF settings) after the start of vblank
 * - gen3/4 pixel and frame counter are synchronized with the start
 *   of horizontal active on the first line of vertical active
 */

static u32 i8xx_get_vblank_counter(struct drm_device *dev, int pipe)
{
        /* Gen2 doesn't have a hardware frame counter */
        return 0;
}

/* Called from drm generic code, passed a 'crtc', which
 * we use as a pipe index
 */
static u32 i915_get_vblank_counter(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long high_frame;
        unsigned long low_frame;
        u32 high1, high2, low, pixel, vbl_start, hsync_start, htotal;
        struct intel_crtc *intel_crtc =
                to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
        const struct drm_display_mode *mode = &intel_crtc->base.hwmode;

        htotal = mode->crtc_htotal;
        hsync_start = mode->crtc_hsync_start;
        vbl_start = mode->crtc_vblank_start;
        if (mode->flags & DRM_MODE_FLAG_INTERLACE)
                vbl_start = DIV_ROUND_UP(vbl_start, 2);

        /* Convert to pixel count */
        vbl_start *= htotal;

        /* Start of vblank event occurs at start of hsync */
        vbl_start -= htotal - hsync_start;

        high_frame = PIPEFRAME(pipe);
        low_frame = PIPEFRAMEPIXEL(pipe);

        /*
         * High & low register fields aren't synchronized, so make sure
         * we get a low value that's stable across two reads of the high
         * register.
         */
        do {
                high1 = I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK;
                low   = I915_READ(low_frame);
                high2 = I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK;
        } while (high1 != high2);

        high1 >>= PIPE_FRAME_HIGH_SHIFT;
        pixel = low & PIPE_PIXEL_MASK;
        low >>= PIPE_FRAME_LOW_SHIFT;

        /*
         * The frame counter increments at beginning of active.
         * Cook up a vblank counter by also checking the pixel
         * counter against vblank start.
         */
        return (((high1 << 8) | low) + (pixel >= vbl_start)) & 0xffffff;
}

static u32 gm45_get_vblank_counter(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int reg = PIPE_FRMCOUNT_GM45(pipe);

        return I915_READ(reg);
}

/* raw reads, only for fast reads of display block, no need for forcewake etc. */
#define __raw_i915_read32(dev_priv__, reg__) readl((dev_priv__)->regs + (reg__))

static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
{
        struct drm_device *dev = crtc->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        const struct drm_display_mode *mode = &crtc->base.hwmode;
        enum pipe pipe = crtc->pipe;
        int position, vtotal;

        vtotal = mode->crtc_vtotal;
        if (mode->flags & DRM_MODE_FLAG_INTERLACE)
                vtotal /= 2;

        if (IS_GEN2(dev))
                position = __raw_i915_read32(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN2;
        else
                position = __raw_i915_read32(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN3;

        /*
         * See update_scanline_offset() for the details on the
         * scanline_offset adjustment.
         */
        return (position + crtc->scanline_offset) % vtotal;
}

static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
                                    unsigned int flags, int *vpos, int *hpos,
                                    ktime_t *stime, ktime_t *etime)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        const struct drm_display_mode *mode = &intel_crtc->base.hwmode;
        int position;
        int vbl_start, vbl_end, hsync_start, htotal, vtotal;
        bool in_vbl = true;
        int ret = 0;
        unsigned long irqflags;

        if (WARN_ON(!mode->crtc_clock)) {
                DRM_DEBUG_DRIVER("trying to get scanoutpos for disabled "
                                 "pipe %c\n", pipe_name(pipe));
                return 0;
        }

        htotal = mode->crtc_htotal;
        hsync_start = mode->crtc_hsync_start;
        vtotal = mode->crtc_vtotal;
        vbl_start = mode->crtc_vblank_start;
        vbl_end = mode->crtc_vblank_end;

        if (mode->flags & DRM_MODE_FLAG_INTERLACE) {
                vbl_start = DIV_ROUND_UP(vbl_start, 2);
                vbl_end /= 2;
                vtotal /= 2;
        }

        ret |= DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE;

        /*
         * Lock uncore.lock, as we will do multiple timing critical raw
         * register reads, potentially with preemption disabled, so the
         * following code must not block on uncore.lock.
         */
        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

        /* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */

        /* Get optional system timestamp before query. */
        if (stime)
                *stime = ktime_get();

        if (IS_GEN2(dev) || IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
                /* No obvious pixelcount register. Only query vertical
                 * scanout position from Display scan line register.
                 */
                position = __intel_get_crtc_scanline(intel_crtc);
        } else {
                /* Have access to pixelcount since start of frame.
                 * We can split this into vertical and horizontal
                 * scanout position.
                 */
                position = (__raw_i915_read32(dev_priv, PIPEFRAMEPIXEL(pipe)) & PIPE_PIXEL_MASK) >> PIPE_PIXEL_SHIFT;

                /* convert to pixel counts */
                vbl_start *= htotal;
                vbl_end *= htotal;
                vtotal *= htotal;

                /*
                 * In interlaced modes, the pixel counter counts all pixels,
                 * so one field will have htotal more pixels. In order to avoid
                 * the reported position from jumping backwards when the pixel
                 * counter is beyond the length of the shorter field, just
                 * clamp the position the length of the shorter field. This
                 * matches how the scanline counter based position works since
                 * the scanline counter doesn't count the two half lines.
                 */
                if (position >= vtotal)
                        position = vtotal - 1;

                /*
                 * Start of vblank interrupt is triggered at start of hsync,
                 * just prior to the first active line of vblank. However we
                 * consider lines to start at the leading edge of horizontal
                 * active. So, should we get here before we've crossed into
                 * the horizontal active of the first line in vblank, we would
                 * not set the DRM_SCANOUTPOS_INVBL flag. In order to fix that,
                 * always add htotal-hsync_start to the current pixel position.
                 */
                position = (position + htotal - hsync_start) % vtotal;
        }

        /* Get optional system timestamp after query. */
        if (etime)
                *etime = ktime_get();

        /* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */

        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);

        in_vbl = position >= vbl_start && position < vbl_end;

        /*
         * While in vblank, position will be negative
         * counting up towards 0 at vbl_end. And outside
         * vblank, position will be positive counting
         * up since vbl_end.
         */
        if (position >= vbl_start)
                position -= vbl_end;
        else
                position += vtotal - vbl_end;

        if (IS_GEN2(dev) || IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
                *vpos = position;
                *hpos = 0;
        } else {
                *vpos = position / htotal;
                *hpos = position - (*vpos * htotal);
        }

        /* In vblank? */
        if (in_vbl)
                ret |= DRM_SCANOUTPOS_IN_VBLANK;

        return ret;
}

int intel_get_crtc_scanline(struct intel_crtc *crtc)
{
        struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
        unsigned long irqflags;
        int position;

        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
        position = __intel_get_crtc_scanline(crtc);
        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);

        return position;
}

static int i915_get_vblank_timestamp(struct drm_device *dev, int pipe,
                              int *max_error,
                              struct timeval *vblank_time,
                              unsigned flags)
{
        struct drm_crtc *crtc;

        if (pipe < 0 || pipe >= INTEL_INFO(dev)->num_pipes) {
                DRM_ERROR("Invalid crtc %d\n", pipe);
                return -EINVAL;
        }

        /* Get drm_crtc to timestamp: */
        crtc = intel_get_crtc_for_pipe(dev, pipe);
        if (crtc == NULL) {
                DRM_ERROR("Invalid crtc %d\n", pipe);
                return -EINVAL;
        }

        if (!crtc->hwmode.crtc_clock) {
                DRM_DEBUG_KMS("crtc %d is disabled\n", pipe);
                return -EBUSY;
        }

        /* Helper routine in DRM core does all the work: */
        return drm_calc_vbltimestamp_from_scanoutpos(dev, pipe, max_error,
                                                     vblank_time, flags,
                                                     crtc,
                                                     &crtc->hwmode);
}

static void ironlake_rps_change_irq_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 busy_up, busy_down, max_avg, min_avg;
        u8 new_delay;

        spin_lock(&mchdev_lock);

        I915_WRITE16(MEMINTRSTS, I915_READ(MEMINTRSTS));

        new_delay = dev_priv->ips.cur_delay;

        I915_WRITE16(MEMINTRSTS, MEMINT_EVAL_CHG);
        busy_up = I915_READ(RCPREVBSYTUPAVG);
        busy_down = I915_READ(RCPREVBSYTDNAVG);
        max_avg = I915_READ(RCBMAXAVG);
        min_avg = I915_READ(RCBMINAVG);

        /* Handle RCS change request from hw */
        if (busy_up > max_avg) {
                if (dev_priv->ips.cur_delay != dev_priv->ips.max_delay)
                        new_delay = dev_priv->ips.cur_delay - 1;
                if (new_delay < dev_priv->ips.max_delay)
                        new_delay = dev_priv->ips.max_delay;
        } else if (busy_down < min_avg) {
                if (dev_priv->ips.cur_delay != dev_priv->ips.min_delay)
                        new_delay = dev_priv->ips.cur_delay + 1;
                if (new_delay > dev_priv->ips.min_delay)
                        new_delay = dev_priv->ips.min_delay;
        }

        if (ironlake_set_drps(dev, new_delay))
                dev_priv->ips.cur_delay = new_delay;

        spin_unlock(&mchdev_lock);

        return;
}

static void notify_ring(struct intel_engine_cs *ring)
{
        if (!intel_ring_initialized(ring))
                return;

        trace_i915_gem_request_notify(ring);

        wake_up_all(&ring->irq_queue);
}

static void vlv_c0_read(struct drm_i915_private *dev_priv,
                        struct intel_rps_ei *ei)
{
        ei->cz_clock = vlv_punit_read(dev_priv, PUNIT_REG_CZ_TIMESTAMP);
        ei->render_c0 = I915_READ(VLV_RENDER_C0_COUNT);
        ei->media_c0 = I915_READ(VLV_MEDIA_C0_COUNT);
}

static bool vlv_c0_above(struct drm_i915_private *dev_priv,
                         const struct intel_rps_ei *old,
                         const struct intel_rps_ei *now,
                         int threshold)
{
        u64 time, c0;

        if (old->cz_clock == 0)
                return false;

        time = now->cz_clock - old->cz_clock;
        time *= threshold * dev_priv->mem_freq;

        /* Workload can be split between render + media, e.g. SwapBuffers
         * being blitted in X after being rendered in mesa. To account for
         * this we need to combine both engines into our activity counter.
         */
        c0 = now->render_c0 - old->render_c0;
        c0 += now->media_c0 - old->media_c0;
        c0 *= 100 * VLV_CZ_CLOCK_TO_MILLI_SEC * 4 / 1000;

        return c0 >= time;
}

void gen6_rps_reset_ei(struct drm_i915_private *dev_priv)
{
        vlv_c0_read(dev_priv, &dev_priv->rps.down_ei);
        dev_priv->rps.up_ei = dev_priv->rps.down_ei;
}

static u32 vlv_wa_c0_ei(struct drm_i915_private *dev_priv, u32 pm_iir)
{
        struct intel_rps_ei now;
        u32 events = 0;

        if ((pm_iir & (GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED)) == 0)
                return 0;

        vlv_c0_read(dev_priv, &now);
        if (now.cz_clock == 0)
                return 0;

        if (pm_iir & GEN6_PM_RP_DOWN_EI_EXPIRED) {
                if (!vlv_c0_above(dev_priv,
                                  &dev_priv->rps.down_ei, &now,
                                  dev_priv->rps.down_threshold))
                        events |= GEN6_PM_RP_DOWN_THRESHOLD;
                dev_priv->rps.down_ei = now;
        }

        if (pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) {
                if (vlv_c0_above(dev_priv,
                                 &dev_priv->rps.up_ei, &now,
                                 dev_priv->rps.up_threshold))
                        events |= GEN6_PM_RP_UP_THRESHOLD;
                dev_priv->rps.up_ei = now;
        }

        return events;
}

static bool any_waiters(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *ring;
        int i;

        for_each_ring(ring, dev_priv, i)
                if (ring->irq_refcount)
                        return true;

        return false;
}

static void gen6_pm_rps_work(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, struct drm_i915_private, rps.work);
        bool client_boost;
        int new_delay, adj, min, max;
        u32 pm_iir;

        spin_lock_irq(&dev_priv->irq_lock);
        /* Speed up work cancelation during disabling rps interrupts. */
        if (!dev_priv->rps.interrupts_enabled) {
                spin_unlock_irq(&dev_priv->irq_lock);
                return;
        }
        pm_iir = dev_priv->rps.pm_iir;
        dev_priv->rps.pm_iir = 0;
        /* Make sure not to corrupt PMIMR state used by ringbuffer on GEN6 */
        gen6_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);
        client_boost = dev_priv->rps.client_boost;
        dev_priv->rps.client_boost = false;
        spin_unlock_irq(&dev_priv->irq_lock);

        /* Make sure we didn't queue anything we're not going to process. */
        WARN_ON(pm_iir & ~dev_priv->pm_rps_events);

        if ((pm_iir & dev_priv->pm_rps_events) == 0 && !client_boost)
                return;

        mutex_lock(&dev_priv->rps.hw_lock);

        pm_iir |= vlv_wa_c0_ei(dev_priv, pm_iir);

        adj = dev_priv->rps.last_adj;
        new_delay = dev_priv->rps.cur_freq;
        min = dev_priv->rps.min_freq_softlimit;
        max = dev_priv->rps.max_freq_softlimit;

        if (client_boost) {
                new_delay = dev_priv->rps.max_freq_softlimit;
                adj = 0;
        } else if (pm_iir & GEN6_PM_RP_UP_THRESHOLD) {
                if (adj > 0)
                        adj *= 2;
                else /* CHV needs even encode values */
                        adj = IS_CHERRYVIEW(dev_priv) ? 2 : 1;
                /*
                 * For better performance, jump directly
                 * to RPe if we're below it.
                 */
                if (new_delay < dev_priv->rps.efficient_freq - adj) {
                        new_delay = dev_priv->rps.efficient_freq;
                        adj = 0;
                }
        } else if (any_waiters(dev_priv)) {
                adj = 0;
        } else if (pm_iir & GEN6_PM_RP_DOWN_TIMEOUT) {
                if (dev_priv->rps.cur_freq > dev_priv->rps.efficient_freq)
                        new_delay = dev_priv->rps.efficient_freq;
                else
                        new_delay = dev_priv->rps.min_freq_softlimit;
                adj = 0;
        } else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
                if (adj < 0)
                        adj *= 2;
                else /* CHV needs even encode values */
                        adj = IS_CHERRYVIEW(dev_priv) ? -2 : -1;
        } else { /* unknown event */
                adj = 0;
        }

        dev_priv->rps.last_adj = adj;

        /* sysfs frequency interfaces may have snuck in while servicing the
         * interrupt
         */
        new_delay += adj;
        new_delay = clamp_t(int, new_delay, min, max);

        intel_set_rps(dev_priv->dev, new_delay);

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


/**
 * ivybridge_parity_work - Workqueue called when a parity error interrupt
 * occurred.
 * @work: workqueue struct
 *
 * Doesn't actually do anything except notify userspace. As a consequence of
 * this event, userspace should try to remap the bad rows since statistically
 * it is likely the same row is more likely to go bad again.
 */
static void ivybridge_parity_work(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, struct drm_i915_private, l3_parity.error_work);
        u32 error_status, row, bank, subbank;
        char *parity_event[6];
        uint32_t misccpctl;
        uint8_t slice = 0;

        /* We must turn off DOP level clock gating to access the L3 registers.
         * In order to prevent a get/put style interface, acquire struct mutex
         * any time we access those registers.
         */
        mutex_lock(&dev_priv->dev->struct_mutex);

        /* If we've screwed up tracking, just let the interrupt fire again */
        if (WARN_ON(!dev_priv->l3_parity.which_slice))
                goto out;

        misccpctl = I915_READ(GEN7_MISCCPCTL);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
        POSTING_READ(GEN7_MISCCPCTL);

        while ((slice = ffs(dev_priv->l3_parity.which_slice)) != 0) {
                u32 reg;

                slice--;
                if (WARN_ON_ONCE(slice >= NUM_L3_SLICES(dev_priv->dev)))
                        break;

                dev_priv->l3_parity.which_slice &= ~(1<<slice);

                reg = GEN7_L3CDERRST1 + (slice * 0x200);

                error_status = I915_READ(reg);
                row = GEN7_PARITY_ERROR_ROW(error_status);
                bank = GEN7_PARITY_ERROR_BANK(error_status);
                subbank = GEN7_PARITY_ERROR_SUBBANK(error_status);

                I915_WRITE(reg, GEN7_PARITY_ERROR_VALID | GEN7_L3CDERRST1_ENABLE);
                POSTING_READ(reg);

                parity_event[0] = I915_L3_PARITY_UEVENT "=1";
                parity_event[1] = kasprintf(GFP_KERNEL, "ROW=%d", row);
                parity_event[2] = kasprintf(GFP_KERNEL, "BANK=%d", bank);
                parity_event[3] = kasprintf(GFP_KERNEL, "SUBBANK=%d", subbank);
                parity_event[4] = kasprintf(GFP_KERNEL, "SLICE=%d", slice);
                parity_event[5] = NULL;

                kobject_uevent_env(&dev_priv->dev->primary->kdev->kobj,
                                   KOBJ_CHANGE, parity_event);

                DRM_DEBUG("Parity error: Slice = %d, Row = %d, Bank = %d, Sub bank = %d.\n",
                          slice, row, bank, subbank);

                kfree(parity_event[4]);
                kfree(parity_event[3]);
                kfree(parity_event[2]);
                kfree(parity_event[1]);
        }

        I915_WRITE(GEN7_MISCCPCTL, misccpctl);

out:
        WARN_ON(dev_priv->l3_parity.which_slice);
        spin_lock_irq(&dev_priv->irq_lock);
        gen5_enable_gt_irq(dev_priv, GT_PARITY_ERROR(dev_priv->dev));
        spin_unlock_irq(&dev_priv->irq_lock);

        mutex_unlock(&dev_priv->dev->struct_mutex);
}

static void ivybridge_parity_error_irq_handler(struct drm_device *dev, u32 iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!HAS_L3_DPF(dev))
                return;

        spin_lock(&dev_priv->irq_lock);
        gen5_disable_gt_irq(dev_priv, GT_PARITY_ERROR(dev));
        spin_unlock(&dev_priv->irq_lock);

        iir &= GT_PARITY_ERROR(dev);
        if (iir & GT_RENDER_L3_PARITY_ERROR_INTERRUPT_S1)
                dev_priv->l3_parity.which_slice |= 1 << 1;

        if (iir & GT_RENDER_L3_PARITY_ERROR_INTERRUPT)
                dev_priv->l3_parity.which_slice |= 1 << 0;

        queue_work(dev_priv->wq, &dev_priv->l3_parity.error_work);
}

static void ilk_gt_irq_handler(struct drm_device *dev,
                               struct drm_i915_private *dev_priv,
                               u32 gt_iir)
{
        if (gt_iir &
            (GT_RENDER_USER_INTERRUPT | GT_RENDER_PIPECTL_NOTIFY_INTERRUPT))
                notify_ring(&dev_priv->ring[RCS]);
        if (gt_iir & ILK_BSD_USER_INTERRUPT)
                notify_ring(&dev_priv->ring[VCS]);
}

static void snb_gt_irq_handler(struct drm_device *dev,
                               struct drm_i915_private *dev_priv,
                               u32 gt_iir)
{

        if (gt_iir &
            (GT_RENDER_USER_INTERRUPT | GT_RENDER_PIPECTL_NOTIFY_INTERRUPT))
                notify_ring(&dev_priv->ring[RCS]);
        if (gt_iir & GT_BSD_USER_INTERRUPT)
                notify_ring(&dev_priv->ring[VCS]);
        if (gt_iir & GT_BLT_USER_INTERRUPT)
                notify_ring(&dev_priv->ring[BCS]);

        if (gt_iir & (GT_BLT_CS_ERROR_INTERRUPT |
                      GT_BSD_CS_ERROR_INTERRUPT |
                      GT_RENDER_CS_MASTER_ERROR_INTERRUPT))
                DRM_DEBUG("Command parser error, gt_iir 0x%08x\n", gt_iir);

        if (gt_iir & GT_PARITY_ERROR(dev))
                ivybridge_parity_error_irq_handler(dev, gt_iir);
}

static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
                                       u32 master_ctl)
{
        irqreturn_t ret = IRQ_NONE;

        if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
                u32 tmp = I915_READ_FW(GEN8_GT_IIR(0));
                if (tmp) {
                        I915_WRITE_FW(GEN8_GT_IIR(0), tmp);
                        ret = IRQ_HANDLED;

                        if (tmp & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT))
                                intel_lrc_irq_handler(&dev_priv->ring[RCS]);
                        if (tmp & (GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT))
                                notify_ring(&dev_priv->ring[RCS]);

                        if (tmp & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT))
                                intel_lrc_irq_handler(&dev_priv->ring[BCS]);
                        if (tmp & (GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT))
                                notify_ring(&dev_priv->ring[BCS]);
                } else
                        DRM_ERROR("The master control interrupt lied (GT0)!\n");
        }

        if (master_ctl & (GEN8_GT_VCS1_IRQ | GEN8_GT_VCS2_IRQ)) {
                u32 tmp = I915_READ_FW(GEN8_GT_IIR(1));
                if (tmp) {
                        I915_WRITE_FW(GEN8_GT_IIR(1), tmp);
                        ret = IRQ_HANDLED;

                        if (tmp & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT))
                                intel_lrc_irq_handler(&dev_priv->ring[VCS]);
                        if (tmp & (GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT))
                                notify_ring(&dev_priv->ring[VCS]);

                        if (tmp & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT))
                                intel_lrc_irq_handler(&dev_priv->ring[VCS2]);
                        if (tmp & (GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT))
                                notify_ring(&dev_priv->ring[VCS2]);
                } else
                        DRM_ERROR("The master control interrupt lied (GT1)!\n");
        }

        if (master_ctl & GEN8_GT_VECS_IRQ) {
                u32 tmp = I915_READ_FW(GEN8_GT_IIR(3));
                if (tmp) {
                        I915_WRITE_FW(GEN8_GT_IIR(3), tmp);
                        ret = IRQ_HANDLED;

                        if (tmp & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT))
                                intel_lrc_irq_handler(&dev_priv->ring[VECS]);
                        if (tmp & (GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT))
                                notify_ring(&dev_priv->ring[VECS]);
                } else
                        DRM_ERROR("The master control interrupt lied (GT3)!\n");
        }

        if (master_ctl & GEN8_GT_PM_IRQ) {
                u32 tmp = I915_READ_FW(GEN8_GT_IIR(2));
                if (tmp & dev_priv->pm_rps_events) {
                        I915_WRITE_FW(GEN8_GT_IIR(2),
                                      tmp & dev_priv->pm_rps_events);
                        ret = IRQ_HANDLED;
                        gen6_rps_irq_handler(dev_priv, tmp);
                } else
                        DRM_ERROR("The master control interrupt lied (PM)!\n");
        }

        return ret;
}

static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_A:
                return val & PORTA_HOTPLUG_LONG_DETECT;
        case PORT_B:
                return val & PORTB_HOTPLUG_LONG_DETECT;
        case PORT_C:
                return val & PORTC_HOTPLUG_LONG_DETECT;
        default:
                return false;
        }
}

static bool spt_port_hotplug2_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_E:
                return val & PORTE_HOTPLUG_LONG_DETECT;
        default:
                return false;
        }
}

static bool spt_port_hotplug_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_A:
                return val & PORTA_HOTPLUG_LONG_DETECT;
        case PORT_B:
                return val & PORTB_HOTPLUG_LONG_DETECT;
        case PORT_C:
                return val & PORTC_HOTPLUG_LONG_DETECT;
        case PORT_D:
                return val & PORTD_HOTPLUG_LONG_DETECT;
        default:
                return false;
        }
}

static bool ilk_port_hotplug_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_A:
                return val & DIGITAL_PORTA_HOTPLUG_LONG_DETECT;
        default:
                return false;
        }
}

static bool pch_port_hotplug_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_B:
                return val & PORTB_HOTPLUG_LONG_DETECT;
        case PORT_C:
                return val & PORTC_HOTPLUG_LONG_DETECT;
        case PORT_D:
                return val & PORTD_HOTPLUG_LONG_DETECT;
        default:
                return false;
        }
}

static bool i9xx_port_hotplug_long_detect(enum port port, u32 val)
{
        switch (port) {
        case PORT_B:
                return val & PORTB_HOTPLUG_INT_LONG_PULSE;
        case PORT_C:
                return val & PORTC_HOTPLUG_INT_LONG_PULSE;
        case PORT_D:
                return val & PORTD_HOTPLUG_INT_LONG_PULSE;
        default:
                return false;
        }
}

/*
 * Get a bit mask of pins that have triggered, and which ones may be long.
 * This can be called multiple times with the same masks to accumulate
 * hotplug detection results from several registers.
 *
 * Note that the caller is expected to zero out the masks initially.
 */
static void intel_get_hpd_pins(u32 *pin_mask, u32 *long_mask,
                             u32 hotplug_trigger, u32 dig_hotplug_reg,
                             const u32 hpd[HPD_NUM_PINS],
                             bool long_pulse_detect(enum port port, u32 val))
{
        enum port port;
        int i;

        for_each_hpd_pin(i) {
                if ((hpd[i] & hotplug_trigger) == 0)
                        continue;

                *pin_mask |= BIT(i);

                if (!intel_hpd_pin_to_port(i, &port))
                        continue;

                if (long_pulse_detect(port, dig_hotplug_reg))
                        *long_mask |= BIT(i);
        }

        DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x, dig 0x%08x, pins 0x%08x\n",
                         hotplug_trigger, dig_hotplug_reg, *pin_mask);

}

static void gmbus_irq_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        wake_up_all(&dev_priv->gmbus_wait_queue);
}

static void dp_aux_irq_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        wake_up_all(&dev_priv->gmbus_wait_queue);
}

#if defined(CONFIG_DEBUG_FS)
static void display_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe,
                                         uint32_t crc0, uint32_t crc1,
                                         uint32_t crc2, uint32_t crc3,
                                         uint32_t crc4)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
        struct intel_pipe_crc_entry *entry;
        int head, tail;

        spin_lock(&pipe_crc->lock);

        if (!pipe_crc->entries) {
                spin_unlock(&pipe_crc->lock);
                DRM_DEBUG_KMS("spurious interrupt\n");
                return;
        }

        head = pipe_crc->head;
        tail = pipe_crc->tail;

        if (CIRC_SPACE(head, tail, INTEL_PIPE_CRC_ENTRIES_NR) < 1) {
                spin_unlock(&pipe_crc->lock);
                DRM_ERROR("CRC buffer overflowing\n");
                return;
        }

        entry = &pipe_crc->entries[head];

        entry->frame = dev->driver->get_vblank_counter(dev, pipe);
        entry->crc[0] = crc0;
        entry->crc[1] = crc1;
        entry->crc[2] = crc2;
        entry->crc[3] = crc3;
        entry->crc[4] = crc4;

        head = (head + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
        pipe_crc->head = head;

        spin_unlock(&pipe_crc->lock);

        wake_up_interruptible(&pipe_crc->wq);
}
#else
static inline void
display_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe,
                             uint32_t crc0, uint32_t crc1,
                             uint32_t crc2, uint32_t crc3,
                             uint32_t crc4) {}
#endif


static void hsw_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        display_pipe_crc_irq_handler(dev, pipe,
                                     I915_READ(PIPE_CRC_RES_1_IVB(pipe)),
                                     0, 0, 0, 0);
}

static void ivb_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        display_pipe_crc_irq_handler(dev, pipe,
                                     I915_READ(PIPE_CRC_RES_1_IVB(pipe)),
                                     I915_READ(PIPE_CRC_RES_2_IVB(pipe)),
                                     I915_READ(PIPE_CRC_RES_3_IVB(pipe)),
                                     I915_READ(PIPE_CRC_RES_4_IVB(pipe)),
                                     I915_READ(PIPE_CRC_RES_5_IVB(pipe)));
}

static void i9xx_pipe_crc_irq_handler(struct drm_device *dev, enum pipe pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t res1, res2;

        if (INTEL_INFO(dev)->gen >= 3)
                res1 = I915_READ(PIPE_CRC_RES_RES1_I915(pipe));
        else
                res1 = 0;

        if (INTEL_INFO(dev)->gen >= 5 || IS_G4X(dev))
                res2 = I915_READ(PIPE_CRC_RES_RES2_G4X(pipe));
        else
                res2 = 0;

        display_pipe_crc_irq_handler(dev, pipe,
                                     I915_READ(PIPE_CRC_RES_RED(pipe)),
                                     I915_READ(PIPE_CRC_RES_GREEN(pipe)),
                                     I915_READ(PIPE_CRC_RES_BLUE(pipe)),
                                     res1, res2);
}

/* The RPS events need forcewake, so we add them to a work queue and mask their
 * IMR bits until the work is done. Other interrupts can be processed without
 * the work queue. */
static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
{
        if (pm_iir & dev_priv->pm_rps_events) {
                spin_lock(&dev_priv->irq_lock);
                gen6_disable_pm_irq(dev_priv, pm_iir & dev_priv->pm_rps_events);
                if (dev_priv->rps.interrupts_enabled) {
                        dev_priv->rps.pm_iir |= pm_iir & dev_priv->pm_rps_events;
                        queue_work(dev_priv->wq, &dev_priv->rps.work);
                }
                spin_unlock(&dev_priv->irq_lock);
        }

        if (INTEL_INFO(dev_priv)->gen >= 8)
                return;

        if (HAS_VEBOX(dev_priv->dev)) {
                if (pm_iir & PM_VEBOX_USER_INTERRUPT)
                        notify_ring(&dev_priv->ring[VECS]);

                if (pm_iir & PM_VEBOX_CS_ERROR_INTERRUPT)
                        DRM_DEBUG("Command parser error, pm_iir 0x%08x\n", pm_iir);
        }
}

static bool intel_pipe_handle_vblank(struct drm_device *dev, enum pipe pipe)
{
        if (!drm_handle_vblank(dev, pipe))
                return false;

        return true;
}

static void valleyview_pipestat_irq_handler(struct drm_device *dev, u32 iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pipe_stats[I915_MAX_PIPES] = { };
        int pipe;

        spin_lock(&dev_priv->irq_lock);
        for_each_pipe(dev_priv, pipe) {
                int reg;
                u32 mask, iir_bit = 0;

                /*
                 * PIPESTAT bits get signalled even when the interrupt is
                 * disabled with the mask bits, and some of the status bits do
                 * not generate interrupts at all (like the underrun bit). Hence
                 * we need to be careful that we only handle what we want to
                 * handle.
                 */

                /* fifo underruns are filterered in the underrun handler. */
                mask = PIPE_FIFO_UNDERRUN_STATUS;

                switch (pipe) {
                case PIPE_A:
                        iir_bit = I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
                        break;
                case PIPE_B:
                        iir_bit = I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
                        break;
                case PIPE_C:
                        iir_bit = I915_DISPLAY_PIPE_C_EVENT_INTERRUPT;
                        break;
                }
                if (iir & iir_bit)
                        mask |= dev_priv->pipestat_irq_mask[pipe];

                if (!mask)
                        continue;

                reg = PIPESTAT(pipe);
                mask |= PIPESTAT_INT_ENABLE_MASK;
                pipe_stats[pipe] = I915_READ(reg) & mask;

                /*
                 * Clear the PIPE*STAT regs before the IIR
                 */
                if (pipe_stats[pipe] & (PIPE_FIFO_UNDERRUN_STATUS |
                                        PIPESTAT_INT_STATUS_MASK))
                        I915_WRITE(reg, pipe_stats[pipe]);
        }
        spin_unlock(&dev_priv->irq_lock);

        for_each_pipe(dev_priv, pipe) {
                if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS &&
                    intel_pipe_handle_vblank(dev, pipe))
                        intel_check_page_flip(dev, pipe);

                if (pipe_stats[pipe] & PLANE_FLIP_DONE_INT_STATUS_VLV) {
                        intel_prepare_page_flip(dev, pipe);
                        intel_finish_page_flip(dev, pipe);
                }

                if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
                        i9xx_pipe_crc_irq_handler(dev, pipe);

                if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
                        intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
        }

        if (pipe_stats[0] & PIPE_GMBUS_INTERRUPT_STATUS)
                gmbus_irq_handler(dev);
}

static void i9xx_hpd_irq_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
        u32 pin_mask = 0, long_mask = 0;

        if (!hotplug_status)
                return;

        I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
        /*
         * Make sure hotplug status is cleared before we clear IIR, or else we
         * may miss hotplug events.
         */
        POSTING_READ(PORT_HOTPLUG_STAT);

        if (IS_G4X(dev) || IS_VALLEYVIEW(dev)) {
                u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_G4X;

                if (hotplug_trigger) {
                        intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                                           hotplug_trigger, hpd_status_g4x,
                                           i9xx_port_hotplug_long_detect);

                        intel_hpd_irq_handler(dev, pin_mask, long_mask);
                }

                if (hotplug_status & DP_AUX_CHANNEL_MASK_INT_STATUS_G4X)
                        dp_aux_irq_handler(dev);
        } else {
                u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_I915;

                if (hotplug_trigger) {
                        intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                                           hotplug_trigger, hpd_status_g4x,
                                           i9xx_port_hotplug_long_detect);

                        intel_hpd_irq_handler(dev, pin_mask, long_mask);
                }
        }
}

static irqreturn_t valleyview_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 iir, gt_iir, pm_iir;
        irqreturn_t ret = IRQ_NONE;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        while (true) {
                /* Find, clear, then process each source of interrupt */

                gt_iir = I915_READ(GTIIR);
                if (gt_iir)
                        I915_WRITE(GTIIR, gt_iir);

                pm_iir = I915_READ(GEN6_PMIIR);
                if (pm_iir)
                        I915_WRITE(GEN6_PMIIR, pm_iir);

                iir = I915_READ(VLV_IIR);
                if (iir) {
                        /* Consume port before clearing IIR or we'll miss events */
                        if (iir & I915_DISPLAY_PORT_INTERRUPT)
                                i9xx_hpd_irq_handler(dev);
                        I915_WRITE(VLV_IIR, iir);
                }

                if (gt_iir == 0 && pm_iir == 0 && iir == 0)
                        goto out;

                ret = IRQ_HANDLED;

                if (gt_iir)
                        snb_gt_irq_handler(dev, dev_priv, gt_iir);
                if (pm_iir)
                        gen6_rps_irq_handler(dev_priv, pm_iir);
                /* Call regardless, as some status bits might not be
                 * signalled in iir */
                valleyview_pipestat_irq_handler(dev, iir);
        }

out:
        return ret;
}

static irqreturn_t cherryview_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 master_ctl, iir;
        irqreturn_t ret = IRQ_NONE;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        for (;;) {
                master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~GEN8_MASTER_IRQ_CONTROL;
                iir = I915_READ(VLV_IIR);

                if (master_ctl == 0 && iir == 0)
                        break;

                ret = IRQ_HANDLED;

                I915_WRITE(GEN8_MASTER_IRQ, 0);

                /* Find, clear, then process each source of interrupt */

                if (iir) {
                        /* Consume port before clearing IIR or we'll miss events */
                        if (iir & I915_DISPLAY_PORT_INTERRUPT)
                                i9xx_hpd_irq_handler(dev);
                        I915_WRITE(VLV_IIR, iir);
                }

                gen8_gt_irq_handler(dev_priv, master_ctl);

                /* Call regardless, as some status bits might not be
                 * signalled in iir */
                valleyview_pipestat_irq_handler(dev, iir);

                I915_WRITE(GEN8_MASTER_IRQ, DE_MASTER_IRQ_CONTROL);
                POSTING_READ(GEN8_MASTER_IRQ);
        }

        return ret;
}

static void ibx_hpd_irq_handler(struct drm_device *dev, u32 hotplug_trigger,
                                const u32 hpd[HPD_NUM_PINS])
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        u32 dig_hotplug_reg, pin_mask = 0, long_mask = 0;

        dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
        I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);

        intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                           dig_hotplug_reg, hpd,
                           pch_port_hotplug_long_detect);

        intel_hpd_irq_handler(dev, pin_mask, long_mask);
}

static void ibx_irq_handler(struct drm_device *dev, u32 pch_iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;
        u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK;

        if (hotplug_trigger)
                ibx_hpd_irq_handler(dev, hotplug_trigger, hpd_ibx);

        if (pch_iir & SDE_AUDIO_POWER_MASK) {
                int port = ffs((pch_iir & SDE_AUDIO_POWER_MASK) >>
                               SDE_AUDIO_POWER_SHIFT);
                DRM_DEBUG_DRIVER("PCH audio power change on port %d\n",
                                 port_name(port));
        }

        if (pch_iir & SDE_AUX_MASK)
                dp_aux_irq_handler(dev);

        if (pch_iir & SDE_GMBUS)
                gmbus_irq_handler(dev);

        if (pch_iir & SDE_AUDIO_HDCP_MASK)
                DRM_DEBUG_DRIVER("PCH HDCP audio interrupt\n");

        if (pch_iir & SDE_AUDIO_TRANS_MASK)
                DRM_DEBUG_DRIVER("PCH transcoder audio interrupt\n");

        if (pch_iir & SDE_POISON)
                DRM_ERROR("PCH poison interrupt\n");

        if (pch_iir & SDE_FDI_MASK)
                for_each_pipe(dev_priv, pipe)
                        DRM_DEBUG_DRIVER("  pipe %c FDI IIR: 0x%08x\n",
                                         pipe_name(pipe),
                                         I915_READ(FDI_RX_IIR(pipe)));

        if (pch_iir & (SDE_TRANSB_CRC_DONE | SDE_TRANSA_CRC_DONE))
                DRM_DEBUG_DRIVER("PCH transcoder CRC done interrupt\n");

        if (pch_iir & (SDE_TRANSB_CRC_ERR | SDE_TRANSA_CRC_ERR))
                DRM_DEBUG_DRIVER("PCH transcoder CRC error interrupt\n");

        if (pch_iir & SDE_TRANSA_FIFO_UNDER)
                intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_A);

        if (pch_iir & SDE_TRANSB_FIFO_UNDER)
                intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_B);
}

static void ivb_err_int_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 err_int = I915_READ(GEN7_ERR_INT);
        enum pipe pipe;

        if (err_int & ERR_INT_POISON)
                DRM_ERROR("Poison interrupt\n");

        for_each_pipe(dev_priv, pipe) {
                if (err_int & ERR_INT_FIFO_UNDERRUN(pipe))
                        intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);

                if (err_int & ERR_INT_PIPE_CRC_DONE(pipe)) {
                        if (IS_IVYBRIDGE(dev))
                                ivb_pipe_crc_irq_handler(dev, pipe);
                        else
                                hsw_pipe_crc_irq_handler(dev, pipe);
                }
        }

        I915_WRITE(GEN7_ERR_INT, err_int);
}

static void cpt_serr_int_handler(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 serr_int = I915_READ(SERR_INT);

        if (serr_int & SERR_INT_POISON)
                DRM_ERROR("PCH poison interrupt\n");

        if (serr_int & SERR_INT_TRANS_A_FIFO_UNDERRUN)
                intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_A);

        if (serr_int & SERR_INT_TRANS_B_FIFO_UNDERRUN)
                intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_B);

        if (serr_int & SERR_INT_TRANS_C_FIFO_UNDERRUN)
                intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_C);

        I915_WRITE(SERR_INT, serr_int);
}

static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;
        u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_CPT;

        if (hotplug_trigger)
                ibx_hpd_irq_handler(dev, hotplug_trigger, hpd_cpt);

        if (pch_iir & SDE_AUDIO_POWER_MASK_CPT) {
                int port = ffs((pch_iir & SDE_AUDIO_POWER_MASK_CPT) >>
                               SDE_AUDIO_POWER_SHIFT_CPT);
                DRM_DEBUG_DRIVER("PCH audio power change on port %c\n",
                                 port_name(port));
        }

        if (pch_iir & SDE_AUX_MASK_CPT)
                dp_aux_irq_handler(dev);

        if (pch_iir & SDE_GMBUS_CPT)
                gmbus_irq_handler(dev);

        if (pch_iir & SDE_AUDIO_CP_REQ_CPT)
                DRM_DEBUG_DRIVER("Audio CP request interrupt\n");

        if (pch_iir & SDE_AUDIO_CP_CHG_CPT)
                DRM_DEBUG_DRIVER("Audio CP change interrupt\n");

        if (pch_iir & SDE_FDI_MASK_CPT)
                for_each_pipe(dev_priv, pipe)
                        DRM_DEBUG_DRIVER("  pipe %c FDI IIR: 0x%08x\n",
                                         pipe_name(pipe),
                                         I915_READ(FDI_RX_IIR(pipe)));

        if (pch_iir & SDE_ERROR_CPT)
                cpt_serr_int_handler(dev);
}

static void spt_irq_handler(struct drm_device *dev, u32 pch_iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_SPT &
                ~SDE_PORTE_HOTPLUG_SPT;
        u32 hotplug2_trigger = pch_iir & SDE_PORTE_HOTPLUG_SPT;
        u32 pin_mask = 0, long_mask = 0;

        if (hotplug_trigger) {
                u32 dig_hotplug_reg;

                dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
                I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);

                intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                                   dig_hotplug_reg, hpd_spt,
                                   spt_port_hotplug_long_detect);
        }

        if (hotplug2_trigger) {
                u32 dig_hotplug_reg;

                dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG2);
                I915_WRITE(PCH_PORT_HOTPLUG2, dig_hotplug_reg);

                intel_get_hpd_pins(&pin_mask, &long_mask, hotplug2_trigger,
                                   dig_hotplug_reg, hpd_spt,
                                   spt_port_hotplug2_long_detect);
        }

        if (pin_mask)
                intel_hpd_irq_handler(dev, pin_mask, long_mask);

        if (pch_iir & SDE_GMBUS_CPT)
                gmbus_irq_handler(dev);
}

static void ilk_hpd_irq_handler(struct drm_device *dev, u32 hotplug_trigger,
                                const u32 hpd[HPD_NUM_PINS])
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        u32 dig_hotplug_reg, pin_mask = 0, long_mask = 0;

        dig_hotplug_reg = I915_READ(DIGITAL_PORT_HOTPLUG_CNTRL);
        I915_WRITE(DIGITAL_PORT_HOTPLUG_CNTRL, dig_hotplug_reg);

        intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                           dig_hotplug_reg, hpd,
                           ilk_port_hotplug_long_detect);

        intel_hpd_irq_handler(dev, pin_mask, long_mask);
}

static void ilk_display_irq_handler(struct drm_device *dev, u32 de_iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum pipe pipe;
        u32 hotplug_trigger = de_iir & DE_DP_A_HOTPLUG;

        if (hotplug_trigger)
                ilk_hpd_irq_handler(dev, hotplug_trigger, hpd_ilk);

        if (de_iir & DE_AUX_CHANNEL_A)
                dp_aux_irq_handler(dev);

        if (de_iir & DE_GSE)
                intel_opregion_asle_intr(dev);

        if (de_iir & DE_POISON)
                DRM_ERROR("Poison interrupt\n");

        for_each_pipe(dev_priv, pipe) {
                if (de_iir & DE_PIPE_VBLANK(pipe) &&
                    intel_pipe_handle_vblank(dev, pipe))
                        intel_check_page_flip(dev, pipe);

                if (de_iir & DE_PIPE_FIFO_UNDERRUN(pipe))
                        intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);

                if (de_iir & DE_PIPE_CRC_DONE(pipe))
                        i9xx_pipe_crc_irq_handler(dev, pipe);

                /* plane/pipes map 1:1 on ilk+ */
                if (de_iir & DE_PLANE_FLIP_DONE(pipe)) {
                        intel_prepare_page_flip(dev, pipe);
                        intel_finish_page_flip_plane(dev, pipe);
                }
        }

        /* check event from PCH */
        if (de_iir & DE_PCH_EVENT) {
                u32 pch_iir = I915_READ(SDEIIR);

                if (HAS_PCH_CPT(dev))
                        cpt_irq_handler(dev, pch_iir);
                else
                        ibx_irq_handler(dev, pch_iir);

                /* should clear PCH hotplug event before clear CPU irq */
                I915_WRITE(SDEIIR, pch_iir);
        }

        if (IS_GEN5(dev) && de_iir & DE_PCU_EVENT)
                ironlake_rps_change_irq_handler(dev);
}

static void ivb_display_irq_handler(struct drm_device *dev, u32 de_iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum pipe pipe;
        u32 hotplug_trigger = de_iir & DE_DP_A_HOTPLUG_IVB;

        if (hotplug_trigger)
                ilk_hpd_irq_handler(dev, hotplug_trigger, hpd_ivb);

        if (de_iir & DE_ERR_INT_IVB)
                ivb_err_int_handler(dev);

        if (de_iir & DE_AUX_CHANNEL_A_IVB)
                dp_aux_irq_handler(dev);

        if (de_iir & DE_GSE_IVB)
                intel_opregion_asle_intr(dev);

        for_each_pipe(dev_priv, pipe) {
                if (de_iir & (DE_PIPE_VBLANK_IVB(pipe)) &&
                    intel_pipe_handle_vblank(dev, pipe))
                        intel_check_page_flip(dev, pipe);

                /* plane/pipes map 1:1 on ilk+ */
                if (de_iir & DE_PLANE_FLIP_DONE_IVB(pipe)) {
                        intel_prepare_page_flip(dev, pipe);
                        intel_finish_page_flip_plane(dev, pipe);
                }
        }

        /* check event from PCH */
        if (!HAS_PCH_NOP(dev) && (de_iir & DE_PCH_EVENT_IVB)) {
                u32 pch_iir = I915_READ(SDEIIR);

                cpt_irq_handler(dev, pch_iir);

                /* clear PCH hotplug event before clear CPU irq */
                I915_WRITE(SDEIIR, pch_iir);
        }
}

/*
 * To handle irqs with the minimum potential races with fresh interrupts, we:
 * 1 - Disable Master Interrupt Control.
 * 2 - Find the source(s) of the interrupt.
 * 3 - Clear the Interrupt Identity bits (IIR).
 * 4 - Process the interrupt(s) that had bits set in the IIRs.
 * 5 - Re-enable Master Interrupt Control.
 */
static irqreturn_t ironlake_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 de_iir, gt_iir, de_ier, sde_ier = 0;
        irqreturn_t ret = IRQ_NONE;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        /* We get interrupts on unclaimed registers, so check for this before we
         * do any I915_{READ,WRITE}. */
        intel_uncore_check_errors(dev);

        /* disable master interrupt before clearing iir  */
        de_ier = I915_READ(DEIER);
        I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
        POSTING_READ(DEIER);

        /* Disable south interrupts. We'll only write to SDEIIR once, so further
         * interrupts will will be stored on its back queue, and then we'll be
         * able to process them after we restore SDEIER (as soon as we restore
         * it, we'll get an interrupt if SDEIIR still has something to process
         * due to its back queue). */
        if (!HAS_PCH_NOP(dev)) {
                sde_ier = I915_READ(SDEIER);
                I915_WRITE(SDEIER, 0);
                POSTING_READ(SDEIER);
        }

        /* Find, clear, then process each source of interrupt */

        gt_iir = I915_READ(GTIIR);
        if (gt_iir) {
                I915_WRITE(GTIIR, gt_iir);
                ret = IRQ_HANDLED;
                if (INTEL_INFO(dev)->gen >= 6)
                        snb_gt_irq_handler(dev, dev_priv, gt_iir);
                else
                        ilk_gt_irq_handler(dev, dev_priv, gt_iir);
        }

        de_iir = I915_READ(DEIIR);
        if (de_iir) {
                I915_WRITE(DEIIR, de_iir);
                ret = IRQ_HANDLED;
                if (INTEL_INFO(dev)->gen >= 7)
                        ivb_display_irq_handler(dev, de_iir);
                else
                        ilk_display_irq_handler(dev, de_iir);
        }

        if (INTEL_INFO(dev)->gen >= 6) {
                u32 pm_iir = I915_READ(GEN6_PMIIR);
                if (pm_iir) {
                        I915_WRITE(GEN6_PMIIR, pm_iir);
                        ret = IRQ_HANDLED;
                        gen6_rps_irq_handler(dev_priv, pm_iir);
                }
        }

        I915_WRITE(DEIER, de_ier);
        POSTING_READ(DEIER);
        if (!HAS_PCH_NOP(dev)) {
                I915_WRITE(SDEIER, sde_ier);
                POSTING_READ(SDEIER);
        }

        return ret;
}

static void bxt_hpd_irq_handler(struct drm_device *dev, u32 hotplug_trigger,
                                const u32 hpd[HPD_NUM_PINS])
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        u32 dig_hotplug_reg, pin_mask = 0, long_mask = 0;

        dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
        I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);

        intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
                           dig_hotplug_reg, hpd,
                           bxt_port_hotplug_long_detect);

        intel_hpd_irq_handler(dev, pin_mask, long_mask);
}

static irqreturn_t gen8_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 master_ctl;
        irqreturn_t ret = IRQ_NONE;
        uint32_t tmp = 0;
        enum pipe pipe;
        u32 aux_mask = GEN8_AUX_CHANNEL_A;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        if (INTEL_INFO(dev_priv)->gen >= 9)
                aux_mask |=  GEN9_AUX_CHANNEL_B | GEN9_AUX_CHANNEL_C |
                        GEN9_AUX_CHANNEL_D;

        master_ctl = I915_READ_FW(GEN8_MASTER_IRQ);
        master_ctl &= ~GEN8_MASTER_IRQ_CONTROL;
        if (!master_ctl)
                return IRQ_NONE;

        I915_WRITE_FW(GEN8_MASTER_IRQ, 0);

        /* Find, clear, then process each source of interrupt */

        ret = gen8_gt_irq_handler(dev_priv, master_ctl);

        if (master_ctl & GEN8_DE_MISC_IRQ) {
                tmp = I915_READ(GEN8_DE_MISC_IIR);
                if (tmp) {
                        I915_WRITE(GEN8_DE_MISC_IIR, tmp);
                        ret = IRQ_HANDLED;
                        if (tmp & GEN8_DE_MISC_GSE)
                                intel_opregion_asle_intr(dev);
                        else
                                DRM_ERROR("Unexpected DE Misc interrupt\n");
                }
                else
                        DRM_ERROR("The master control interrupt lied (DE MISC)!\n");
        }

        if (master_ctl & GEN8_DE_PORT_IRQ) {
                tmp = I915_READ(GEN8_DE_PORT_IIR);
                if (tmp) {
                        bool found = false;
                        u32 hotplug_trigger = 0;

                        if (IS_BROXTON(dev_priv))
                                hotplug_trigger = tmp & BXT_DE_PORT_HOTPLUG_MASK;
                        else if (IS_BROADWELL(dev_priv))
                                hotplug_trigger = tmp & GEN8_PORT_DP_A_HOTPLUG;

                        I915_WRITE(GEN8_DE_PORT_IIR, tmp);
                        ret = IRQ_HANDLED;

                        if (tmp & aux_mask) {
                                dp_aux_irq_handler(dev);
                                found = true;
                        }

                        if (hotplug_trigger) {
                                if (IS_BROXTON(dev))
                                        bxt_hpd_irq_handler(dev, hotplug_trigger, hpd_bxt);
                                else
                                        ilk_hpd_irq_handler(dev, hotplug_trigger, hpd_bdw);
                                found = true;
                        }

                        if (IS_BROXTON(dev) && (tmp & BXT_DE_PORT_GMBUS)) {
                                gmbus_irq_handler(dev);
                                found = true;
                        }

                        if (!found)
                                DRM_ERROR("Unexpected DE Port interrupt\n");
                }
                else
                        DRM_ERROR("The master control interrupt lied (DE PORT)!\n");
        }

        for_each_pipe(dev_priv, pipe) {
                uint32_t pipe_iir, flip_done = 0, fault_errors = 0;

                if (!(master_ctl & GEN8_DE_PIPE_IRQ(pipe)))
                        continue;

                pipe_iir = I915_READ(GEN8_DE_PIPE_IIR(pipe));
                if (pipe_iir) {
                        ret = IRQ_HANDLED;
                        I915_WRITE(GEN8_DE_PIPE_IIR(pipe), pipe_iir);

                        if (pipe_iir & GEN8_PIPE_VBLANK &&
                            intel_pipe_handle_vblank(dev, pipe))
                                intel_check_page_flip(dev, pipe);

                        if (INTEL_INFO(dev_priv)->gen >= 9)
                                flip_done = pipe_iir & GEN9_PIPE_PLANE1_FLIP_DONE;
                        else
                                flip_done = pipe_iir & GEN8_PIPE_PRIMARY_FLIP_DONE;

                        if (flip_done) {
                                intel_prepare_page_flip(dev, pipe);
                                intel_finish_page_flip_plane(dev, pipe);
                        }

                        if (pipe_iir & GEN8_PIPE_CDCLK_CRC_DONE)
                                hsw_pipe_crc_irq_handler(dev, pipe);

                        if (pipe_iir & GEN8_PIPE_FIFO_UNDERRUN)
                                intel_cpu_fifo_underrun_irq_handler(dev_priv,
                                                                    pipe);


                        if (INTEL_INFO(dev_priv)->gen >= 9)
                                fault_errors = pipe_iir & GEN9_DE_PIPE_IRQ_FAULT_ERRORS;
                        else
                                fault_errors = pipe_iir & GEN8_DE_PIPE_IRQ_FAULT_ERRORS;

                        if (fault_errors)
                                DRM_ERROR("Fault errors on pipe %c\n: 0x%08x",
                                          pipe_name(pipe),
                                          pipe_iir & GEN8_DE_PIPE_IRQ_FAULT_ERRORS);
                } else
                        DRM_ERROR("The master control interrupt lied (DE PIPE)!\n");
        }

        if (HAS_PCH_SPLIT(dev) && !HAS_PCH_NOP(dev) &&
            master_ctl & GEN8_DE_PCH_IRQ) {
                /*
                 * FIXME(BDW): Assume for now that the new interrupt handling
                 * scheme also closed the SDE interrupt handling race we've seen
                 * on older pch-split platforms. But this needs testing.
                 */
                u32 pch_iir = I915_READ(SDEIIR);
                if (pch_iir) {
                        I915_WRITE(SDEIIR, pch_iir);
                        ret = IRQ_HANDLED;

                        if (HAS_PCH_SPT(dev_priv))
                                spt_irq_handler(dev, pch_iir);
                        else
                                cpt_irq_handler(dev, pch_iir);
                } else
                        DRM_ERROR("The master control interrupt lied (SDE)!\n");

        }

        I915_WRITE_FW(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL);
        POSTING_READ_FW(GEN8_MASTER_IRQ);

        return ret;
}

static void i915_error_wake_up(struct drm_i915_private *dev_priv,
                               bool reset_completed)
{
        struct intel_engine_cs *ring;
        int i;

        /*
         * Notify all waiters for GPU completion events that reset state has
         * been changed, and that they need to restart their wait after
         * checking for potential errors (and bail out to drop locks if there is
         * a gpu reset pending so that i915_error_work_func can acquire them).
         */

        /* Wake up __wait_seqno, potentially holding dev->struct_mutex. */
        for_each_ring(ring, dev_priv, i)
                wake_up_all(&ring->irq_queue);

        /* Wake up intel_crtc_wait_for_pending_flips, holding crtc->mutex. */
        wake_up_all(&dev_priv->pending_flip_queue);

        /*
         * Signal tasks blocked in i915_gem_wait_for_error that the pending
         * reset state is cleared.
         */
        if (reset_completed)
                wake_up_all(&dev_priv->gpu_error.reset_queue);
}

/**
 * i915_reset_and_wakeup - do process context error handling work
 *
 * Fire an error uevent so userspace can see that a hang or error
 * was detected.
 */
static void i915_reset_and_wakeup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct i915_gpu_error *error = &dev_priv->gpu_error;
        char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
        char *reset_event[] = { I915_RESET_UEVENT "=1", NULL };
        char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL };
        int ret;

        kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, error_event);

        /*
         * Note that there's only one work item which does gpu resets, so we
         * need not worry about concurrent gpu resets potentially incrementing
         * error->reset_counter twice. We only need to take care of another
         * racing irq/hangcheck declaring the gpu dead for a second time. A
         * quick check for that is good enough: schedule_work ensures the
         * correct ordering between hang detection and this work item, and since
         * the reset in-progress bit is only ever set by code outside of this
         * work we don't need to worry about any other races.
         */
        if (i915_reset_in_progress(error) && !i915_terminally_wedged(error)) {
                DRM_DEBUG_DRIVER("resetting chip\n");
                kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE,
                                   reset_event);

                /*
                 * In most cases it's guaranteed that we get here with an RPM
                 * reference held, for example because there is a pending GPU
                 * request that won't finish until the reset is done. This
                 * isn't the case at least when we get here by doing a
                 * simulated reset via debugs, so get an RPM reference.
                 */
                intel_runtime_pm_get(dev_priv);

                intel_prepare_reset(dev);

                /*
                 * All state reset _must_ be completed before we update the
                 * reset counter, for otherwise waiters might miss the reset
                 * pending state and not properly drop locks, resulting in
                 * deadlocks with the reset work.
                 */
                ret = i915_reset(dev);

                intel_finish_reset(dev);

                intel_runtime_pm_put(dev_priv);

                if (ret == 0) {
                        /*
                         * After all the gem state is reset, increment the reset
                         * counter and wake up everyone waiting for the reset to
                         * complete.
                         *
                         * Since unlock operations are a one-sided barrier only,
                         * we need to insert a barrier here to order any seqno
                         * updates before
                         * the counter increment.
                         */
                        smp_mb__before_atomic();
                        atomic_inc(&dev_priv->gpu_error.reset_counter);

                        kobject_uevent_env(&dev->primary->kdev->kobj,
                                           KOBJ_CHANGE, reset_done_event);
                } else {
                        atomic_set_mask(I915_WEDGED, &error->reset_counter);
                }

                /*
                 * Note: The wake_up also serves as a memory barrier so that
                 * waiters see the update value of the reset counter atomic_t.
                 */
                i915_error_wake_up(dev_priv, true);
        }
}

static void i915_report_and_clear_eir(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t instdone[I915_NUM_INSTDONE_REG];
        u32 eir = I915_READ(EIR);
        int pipe, i;

        if (!eir)
                return;

        pr_err("render error detected, EIR: 0x%08x\n", eir);

        i915_get_extra_instdone(dev, instdone);

        if (IS_G4X(dev)) {
                if (eir & (GM45_ERROR_MEM_PRIV | GM45_ERROR_CP_PRIV)) {
                        u32 ipeir = I915_READ(IPEIR_I965);

                        pr_err("  IPEIR: 0x%08x\n", I915_READ(IPEIR_I965));
                        pr_err("  IPEHR: 0x%08x\n", I915_READ(IPEHR_I965));
                        for (i = 0; i < ARRAY_SIZE(instdone); i++)
                                pr_err("  INSTDONE_%d: 0x%08x\n", i, instdone[i]);
                        pr_err("  INSTPS: 0x%08x\n", I915_READ(INSTPS));
                        pr_err("  ACTHD: 0x%08x\n", I915_READ(ACTHD_I965));
                        I915_WRITE(IPEIR_I965, ipeir);
                        POSTING_READ(IPEIR_I965);
                }
                if (eir & GM45_ERROR_PAGE_TABLE) {
                        u32 pgtbl_err = I915_READ(PGTBL_ER);
                        pr_err("page table error\n");
                        pr_err("  PGTBL_ER: 0x%08x\n", pgtbl_err);
                        I915_WRITE(PGTBL_ER, pgtbl_err);
                        POSTING_READ(PGTBL_ER);
                }
        }

        if (!IS_GEN2(dev)) {
                if (eir & I915_ERROR_PAGE_TABLE) {
                        u32 pgtbl_err = I915_READ(PGTBL_ER);
                        pr_err("page table error\n");
                        pr_err("  PGTBL_ER: 0x%08x\n", pgtbl_err);
                        I915_WRITE(PGTBL_ER, pgtbl_err);
                        POSTING_READ(PGTBL_ER);
                }
        }

        if (eir & I915_ERROR_MEMORY_REFRESH) {
                pr_err("memory refresh error:\n");
                for_each_pipe(dev_priv, pipe)
                        pr_err("pipe %c stat: 0x%08x\n",
                               pipe_name(pipe), I915_READ(PIPESTAT(pipe)));
                /* pipestat has already been acked */
        }
        if (eir & I915_ERROR_INSTRUCTION) {
                pr_err("instruction error\n");
                pr_err("  INSTPM: 0x%08x\n", I915_READ(INSTPM));
                for (i = 0; i < ARRAY_SIZE(instdone); i++)
                        pr_err("  INSTDONE_%d: 0x%08x\n", i, instdone[i]);
                if (INTEL_INFO(dev)->gen < 4) {
                        u32 ipeir = I915_READ(IPEIR);

                        pr_err("  IPEIR: 0x%08x\n", I915_READ(IPEIR));
                        pr_err("  IPEHR: 0x%08x\n", I915_READ(IPEHR));
                        pr_err("  ACTHD: 0x%08x\n", I915_READ(ACTHD));
                        I915_WRITE(IPEIR, ipeir);
                        POSTING_READ(IPEIR);
                } else {
                        u32 ipeir = I915_READ(IPEIR_I965);

                        pr_err("  IPEIR: 0x%08x\n", I915_READ(IPEIR_I965));
                        pr_err("  IPEHR: 0x%08x\n", I915_READ(IPEHR_I965));
                        pr_err("  INSTPS: 0x%08x\n", I915_READ(INSTPS));
                        pr_err("  ACTHD: 0x%08x\n", I915_READ(ACTHD_I965));
                        I915_WRITE(IPEIR_I965, ipeir);
                        POSTING_READ(IPEIR_I965);
                }
        }

        I915_WRITE(EIR, eir);
        POSTING_READ(EIR);
        eir = I915_READ(EIR);
        if (eir) {
                /*
                 * some errors might have become stuck,
                 * mask them.
                 */
                DRM_ERROR("EIR stuck: 0x%08x, masking\n", eir);
                I915_WRITE(EMR, I915_READ(EMR) | eir);
                I915_WRITE(IIR, I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
        }
}

/**
 * i915_handle_error - handle a gpu error
 * @dev: drm device
 *
 * Do some basic checking of regsiter state at error time and
 * dump it to the syslog.  Also call i915_capture_error_state() to make
 * sure we get a record and make it available in debugfs.  Fire a uevent
 * so userspace knows something bad happened (should trigger collection
 * of a ring dump etc.).
 */
void i915_handle_error(struct drm_device *dev, bool wedged,
                       const char *fmt, ...)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        va_list args;
        char error_msg[80];

        va_start(args, fmt);
        vscnprintf(error_msg, sizeof(error_msg), fmt, args);
        va_end(args);

        i915_capture_error_state(dev, wedged, error_msg);
        i915_report_and_clear_eir(dev);

        if (wedged) {
                atomic_set_mask(I915_RESET_IN_PROGRESS_FLAG,
                                &dev_priv->gpu_error.reset_counter);

                /*
                 * Wakeup waiting processes so that the reset function
                 * i915_reset_and_wakeup doesn't deadlock trying to grab
                 * various locks. By bumping the reset counter first, the woken
                 * processes will see a reset in progress and back off,
                 * releasing their locks and then wait for the reset completion.
                 * We must do this for _all_ gpu waiters that might hold locks
                 * that the reset work needs to acquire.
                 *
                 * Note: The wake_up serves as the required memory barrier to
                 * ensure that the waiters see the updated value of the reset
                 * counter atomic_t.
                 */
                i915_error_wake_up(dev_priv, false);
        }

        i915_reset_and_wakeup(dev);
}

/* Called from drm generic code, passed 'crtc' which
 * we use as a pipe index
 */
static int i915_enable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        if (INTEL_INFO(dev)->gen >= 4)
                i915_enable_pipestat(dev_priv, pipe,
                                     PIPE_START_VBLANK_INTERRUPT_STATUS);
        else
                i915_enable_pipestat(dev_priv, pipe,
                                     PIPE_VBLANK_INTERRUPT_STATUS);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);

        return 0;
}

static int ironlake_enable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;
        uint32_t bit = (INTEL_INFO(dev)->gen >= 7) ? DE_PIPE_VBLANK_IVB(pipe) :
                                                     DE_PIPE_VBLANK(pipe);

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        ironlake_enable_display_irq(dev_priv, bit);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);

        return 0;
}

static int valleyview_enable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        i915_enable_pipestat(dev_priv, pipe,
                             PIPE_START_VBLANK_INTERRUPT_STATUS);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);

        return 0;
}

static int gen8_enable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        dev_priv->de_irq_mask[pipe] &= ~GEN8_PIPE_VBLANK;
        I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]);
        POSTING_READ(GEN8_DE_PIPE_IMR(pipe));
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
        return 0;
}

/* Called from drm generic code, passed 'crtc' which
 * we use as a pipe index
 */
static void i915_disable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        i915_disable_pipestat(dev_priv, pipe,
                              PIPE_VBLANK_INTERRUPT_STATUS |
                              PIPE_START_VBLANK_INTERRUPT_STATUS);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static void ironlake_disable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;
        uint32_t bit = (INTEL_INFO(dev)->gen >= 7) ? DE_PIPE_VBLANK_IVB(pipe) :
                                                     DE_PIPE_VBLANK(pipe);

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        ironlake_disable_display_irq(dev_priv, bit);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static void valleyview_disable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        i915_disable_pipestat(dev_priv, pipe,
                              PIPE_START_VBLANK_INTERRUPT_STATUS);
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static void gen8_disable_vblank(struct drm_device *dev, int pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
        dev_priv->de_irq_mask[pipe] |= GEN8_PIPE_VBLANK;
        I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]);
        POSTING_READ(GEN8_DE_PIPE_IMR(pipe));
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static bool
ring_idle(struct intel_engine_cs *ring, u32 seqno)
{
        return (list_empty(&ring->request_list) ||
                i915_seqno_passed(seqno, ring->last_submitted_seqno));
}

static bool
ipehr_is_semaphore_wait(struct drm_device *dev, u32 ipehr)
{
        if (INTEL_INFO(dev)->gen >= 8) {
                return (ipehr >> 23) == 0x1c;
        } else {
                ipehr &= ~MI_SEMAPHORE_SYNC_MASK;
                return ipehr == (MI_SEMAPHORE_MBOX | MI_SEMAPHORE_COMPARE |
                                 MI_SEMAPHORE_REGISTER);
        }
}

static struct intel_engine_cs *
semaphore_wait_to_signaller_ring(struct intel_engine_cs *ring, u32 ipehr, u64 offset)
{
        struct drm_i915_private *dev_priv = ring->dev->dev_private;
        struct intel_engine_cs *signaller;
        int i;

        if (INTEL_INFO(dev_priv->dev)->gen >= 8) {
                for_each_ring(signaller, dev_priv, i) {
                        if (ring == signaller)
                                continue;

                        if (offset == signaller->semaphore.signal_ggtt[ring->id])
                                return signaller;
                }
        } else {
                u32 sync_bits = ipehr & MI_SEMAPHORE_SYNC_MASK;

                for_each_ring(signaller, dev_priv, i) {
                        if(ring == signaller)
                                continue;

                        if (sync_bits == signaller->semaphore.mbox.wait[ring->id])
                                return signaller;
                }
        }

        DRM_ERROR("No signaller ring found for ring %i, ipehr 0x%08x, offset 0x%016llx\n",
                  ring->id, ipehr, offset);

        return NULL;
}

static struct intel_engine_cs *
semaphore_waits_for(struct intel_engine_cs *ring, u32 *seqno)
{
        struct drm_i915_private *dev_priv = ring->dev->dev_private;
        u32 cmd, ipehr, head;
        u64 offset = 0;
        int i, backwards;

        ipehr = I915_READ(RING_IPEHR(ring->mmio_base));
        if (!ipehr_is_semaphore_wait(ring->dev, ipehr))
                return NULL;

        /*
         * HEAD is likely pointing to the dword after the actual command,
         * so scan backwards until we find the MBOX. But limit it to just 3
         * or 4 dwords depending on the semaphore wait command size.
         * Note that we don't care about ACTHD here since that might
         * point at at batch, and semaphores are always emitted into the
         * ringbuffer itself.
         */
        head = I915_READ_HEAD(ring) & HEAD_ADDR;
        backwards = (INTEL_INFO(ring->dev)->gen >= 8) ? 5 : 4;

        for (i = backwards; i; --i) {
                /*
                 * Be paranoid and presume the hw has gone off into the wild -
                 * our ring is smaller than what the hardware (and hence
                 * HEAD_ADDR) allows. Also handles wrap-around.
                 */
                head &= ring->buffer->size - 1;

                /* This here seems to blow up */
                cmd = ioread32(ring->buffer->virtual_start + head);
                if (cmd == ipehr)
                        break;

                head -= 4;
        }

        if (!i)
                return NULL;

        *seqno = ioread32(ring->buffer->virtual_start + head + 4) + 1;
        if (INTEL_INFO(ring->dev)->gen >= 8) {
                offset = ioread32(ring->buffer->virtual_start + head + 12);
                offset <<= 32;
                offset = ioread32(ring->buffer->virtual_start + head + 8);
        }
        return semaphore_wait_to_signaller_ring(ring, ipehr, offset);
}

static int semaphore_passed(struct intel_engine_cs *ring)
{
        struct drm_i915_private *dev_priv = ring->dev->dev_private;
        struct intel_engine_cs *signaller;
        u32 seqno;

        ring->hangcheck.deadlock++;

        signaller = semaphore_waits_for(ring, &seqno);
        if (signaller == NULL)
                return -1;

        /* Prevent pathological recursion due to driver bugs */
        if (signaller->hangcheck.deadlock >= I915_NUM_RINGS)
                return -1;

        if (i915_seqno_passed(signaller->get_seqno(signaller, false), seqno))
                return 1;

        /* cursory check for an unkickable deadlock */
        if (I915_READ_CTL(signaller) & RING_WAIT_SEMAPHORE &&
            semaphore_passed(signaller) < 0)
                return -1;

        return 0;
}

static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)
{
        struct intel_engine_cs *ring;
        int i;

        for_each_ring(ring, dev_priv, i)
                ring->hangcheck.deadlock = 0;
}

static enum intel_ring_hangcheck_action
ring_stuck(struct intel_engine_cs *ring, u64 acthd)
{
        struct drm_device *dev = ring->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 tmp;

        if (acthd != ring->hangcheck.acthd) {
                if (acthd > ring->hangcheck.max_acthd) {
                        ring->hangcheck.max_acthd = acthd;
                        return HANGCHECK_ACTIVE;
                }

                return HANGCHECK_ACTIVE_LOOP;
        }

        if (IS_GEN2(dev))
                return HANGCHECK_HUNG;

        /* Is the chip hanging on a WAIT_FOR_EVENT?
         * If so we can simply poke the RB_WAIT bit
         * and break the hang. This should work on
         * all but the second generation chipsets.
         */
        tmp = I915_READ_CTL(ring);
        if (tmp & RING_WAIT) {
                i915_handle_error(dev, false,
                                  "Kicking stuck wait on %s",
                                  ring->name);
                I915_WRITE_CTL(ring, tmp);
                return HANGCHECK_KICK;
        }

        if (INTEL_INFO(dev)->gen >= 6 && tmp & RING_WAIT_SEMAPHORE) {
                switch (semaphore_passed(ring)) {
                default:
                        return HANGCHECK_HUNG;
                case 1:
                        i915_handle_error(dev, false,
                                          "Kicking stuck semaphore on %s",
                                          ring->name);
                        I915_WRITE_CTL(ring, tmp);
                        return HANGCHECK_KICK;
                case 0:
                        return HANGCHECK_WAIT;
                }
        }

        return HANGCHECK_HUNG;
}

/*
 * This is called when the chip hasn't reported back with completed
 * batchbuffers in a long time. We keep track per ring seqno progress and
 * if there are no progress, hangcheck score for that ring is increased.
 * Further, acthd is inspected to see if the ring is stuck. On stuck case
 * we kick the ring. If we see no progress on three subsequent calls
 * we assume chip is wedged and try to fix it by resetting the chip.
 */
static void i915_hangcheck_elapsed(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, typeof(*dev_priv),
                             gpu_error.hangcheck_work.work);
        struct drm_device *dev = dev_priv->dev;
        struct intel_engine_cs *ring;
        int i;
        int busy_count = 0, rings_hung = 0;
        bool stuck[I915_NUM_RINGS] = { 0 };
#define BUSY 1
#define KICK 5
#define HUNG 20

        if (!i915.enable_hangcheck)
                return;

        for_each_ring(ring, dev_priv, i) {
                u64 acthd;
                u32 seqno;
                bool busy = true;

                semaphore_clear_deadlocks(dev_priv);

                seqno = ring->get_seqno(ring, false);
                acthd = intel_ring_get_active_head(ring);

                if (ring->hangcheck.seqno == seqno) {
                        if (ring_idle(ring, seqno)) {
                                ring->hangcheck.action = HANGCHECK_IDLE;

                                if (waitqueue_active(&ring->irq_queue)) {
                                        /* Issue a wake-up to catch stuck h/w. */
                                        if (!test_and_set_bit(ring->id, &dev_priv->gpu_error.missed_irq_rings)) {
                                                if (!(dev_priv->gpu_error.test_irq_rings & intel_ring_flag(ring)))
                                                        DRM_ERROR("Hangcheck timer elapsed... %s idle\n",
                                                                  ring->name);
                                                else
                                                        DRM_INFO("Fake missed irq on %s\n",
                                                                 ring->name);
                                                wake_up_all(&ring->irq_queue);
                                        }
                                        /* Safeguard against driver failure */
                                        ring->hangcheck.score += BUSY;
                                } else
                                        busy = false;
                        } else {
                                /* We always increment the hangcheck score
                                 * if the ring is busy and still processing
                                 * the same request, so that no single request
                                 * can run indefinitely (such as a chain of
                                 * batches). The only time we do not increment
                                 * the hangcheck score on this ring, if this
                                 * ring is in a legitimate wait for another
                                 * ring. In that case the waiting ring is a
                                 * victim and we want to be sure we catch the
                                 * right culprit. Then every time we do kick
                                 * the ring, add a small increment to the
                                 * score so that we can catch a batch that is
                                 * being repeatedly kicked and so responsible
                                 * for stalling the machine.
                                 */
                                ring->hangcheck.action = ring_stuck(ring,
                                                                    acthd);

                                switch (ring->hangcheck.action) {
                                case HANGCHECK_IDLE:
                                case HANGCHECK_WAIT:
                                case HANGCHECK_ACTIVE:
                                        break;
                                case HANGCHECK_ACTIVE_LOOP:
                                        ring->hangcheck.score += BUSY;
                                        break;
                                case HANGCHECK_KICK:
                                        ring->hangcheck.score += KICK;
                                        break;
                                case HANGCHECK_HUNG:
                                        ring->hangcheck.score += HUNG;
                                        stuck[i] = true;
                                        break;
                                }
                        }
                } else {
                        ring->hangcheck.action = HANGCHECK_ACTIVE;

                        /* Gradually reduce the count so that we catch DoS
                         * attempts across multiple batches.
                         */
                        if (ring->hangcheck.score > 0)
                                ring->hangcheck.score--;

                        ring->hangcheck.acthd = ring->hangcheck.max_acthd = 0;
                }

                ring->hangcheck.seqno = seqno;
                ring->hangcheck.acthd = acthd;
                busy_count += busy;
        }

        for_each_ring(ring, dev_priv, i) {
                if (ring->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG) {
                        DRM_INFO("%s on %s\n",
                                 stuck[i] ? "stuck" : "no progress",
                                 ring->name);
                        rings_hung++;
                }
        }

        if (rings_hung)
                return i915_handle_error(dev, true, "Ring hung");

        if (busy_count)
                /* Reset timer case chip hangs without another request
                 * being added */
                i915_queue_hangcheck(dev);
}

void i915_queue_hangcheck(struct drm_device *dev)
{
        struct i915_gpu_error *e = &to_i915(dev)->gpu_error;

        if (!i915.enable_hangcheck)
                return;

        /* Don't continually defer the hangcheck so that it is always run at
         * least once after work has been scheduled on any ring. Otherwise,
         * we will ignore a hung ring if a second ring is kept busy.
         */

        queue_delayed_work(e->hangcheck_wq, &e->hangcheck_work,
                           round_jiffies_up_relative(DRM_I915_HANGCHECK_JIFFIES));
}

static void ibx_irq_reset(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (HAS_PCH_NOP(dev))
                return;

        GEN5_IRQ_RESET(SDE);

        if (HAS_PCH_CPT(dev) || HAS_PCH_LPT(dev))
                I915_WRITE(SERR_INT, 0xffffffff);
}

/*
 * SDEIER is also touched by the interrupt handler to work around missed PCH
 * interrupts. Hence we can't update it after the interrupt handler is enabled -
 * instead we unconditionally enable all PCH interrupt sources here, but then
 * only unmask them as needed with SDEIMR.
 *
 * This function needs to be called before interrupts are enabled.
 */
static void ibx_irq_pre_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (HAS_PCH_NOP(dev))
                return;

        WARN_ON(I915_READ(SDEIER) != 0);
        I915_WRITE(SDEIER, 0xffffffff);
        POSTING_READ(SDEIER);
}

static void gen5_gt_irq_reset(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        GEN5_IRQ_RESET(GT);
        if (INTEL_INFO(dev)->gen >= 6)
                GEN5_IRQ_RESET(GEN6_PM);
}

/* drm_dma.h hooks
*/
static void ironlake_irq_reset(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(HWSTAM, 0xffffffff);

        GEN5_IRQ_RESET(DE);
        if (IS_GEN7(dev))
                I915_WRITE(GEN7_ERR_INT, 0xffffffff);

        gen5_gt_irq_reset(dev);

        ibx_irq_reset(dev);
}

static void vlv_display_irq_reset(struct drm_i915_private *dev_priv)
{
        enum pipe pipe;

        i915_hotplug_interrupt_update(dev_priv, 0xFFFFFFFF, 0);
        I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));

        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), 0xffff);

        GEN5_IRQ_RESET(VLV_);
}

static void valleyview_irq_preinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        /* VLV magic */
        I915_WRITE(VLV_IMR, 0);
        I915_WRITE(RING_IMR(RENDER_RING_BASE), 0);
        I915_WRITE(RING_IMR(GEN6_BSD_RING_BASE), 0);
        I915_WRITE(RING_IMR(BLT_RING_BASE), 0);

        gen5_gt_irq_reset(dev);

        I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);

        vlv_display_irq_reset(dev_priv);
}

static void gen8_gt_irq_reset(struct drm_i915_private *dev_priv)
{
        GEN8_IRQ_RESET_NDX(GT, 0);
        GEN8_IRQ_RESET_NDX(GT, 1);
        GEN8_IRQ_RESET_NDX(GT, 2);
        GEN8_IRQ_RESET_NDX(GT, 3);
}

static void gen8_irq_reset(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        I915_WRITE(GEN8_MASTER_IRQ, 0);
        POSTING_READ(GEN8_MASTER_IRQ);

        gen8_gt_irq_reset(dev_priv);

        for_each_pipe(dev_priv, pipe)
                if (intel_display_power_is_enabled(dev_priv,
                                                   POWER_DOMAIN_PIPE(pipe)))
                        GEN8_IRQ_RESET_NDX(DE_PIPE, pipe);

        GEN5_IRQ_RESET(GEN8_DE_PORT_);
        GEN5_IRQ_RESET(GEN8_DE_MISC_);
        GEN5_IRQ_RESET(GEN8_PCU_);

        if (HAS_PCH_SPLIT(dev))
                ibx_irq_reset(dev);
}

void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
                                     unsigned int pipe_mask)
{
        uint32_t extra_ier = GEN8_PIPE_VBLANK | GEN8_PIPE_FIFO_UNDERRUN;

        spin_lock_irq(&dev_priv->irq_lock);
        if (pipe_mask & 1 << PIPE_A)
                GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_A,
                                  dev_priv->de_irq_mask[PIPE_A],
                                  ~dev_priv->de_irq_mask[PIPE_A] | extra_ier);
        if (pipe_mask & 1 << PIPE_B)
                GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_B,
                                  dev_priv->de_irq_mask[PIPE_B],
                                  ~dev_priv->de_irq_mask[PIPE_B] | extra_ier);
        if (pipe_mask & 1 << PIPE_C)
                GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_C,
                                  dev_priv->de_irq_mask[PIPE_C],
                                  ~dev_priv->de_irq_mask[PIPE_C] | extra_ier);
        spin_unlock_irq(&dev_priv->irq_lock);
}

static void cherryview_irq_preinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE(GEN8_MASTER_IRQ, 0);
        POSTING_READ(GEN8_MASTER_IRQ);

        gen8_gt_irq_reset(dev_priv);

        GEN5_IRQ_RESET(GEN8_PCU_);

        I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK_CHV);

        vlv_display_irq_reset(dev_priv);
}

static u32 intel_hpd_enabled_irqs(struct drm_device *dev,
                                  const u32 hpd[HPD_NUM_PINS])
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_encoder *encoder;
        u32 enabled_irqs = 0;

        for_each_intel_encoder(dev, encoder)
                if (dev_priv->hotplug.stats[encoder->hpd_pin].state == HPD_ENABLED)
                        enabled_irqs |= hpd[encoder->hpd_pin];

        return enabled_irqs;
}

static void ibx_hpd_irq_setup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_irqs, hotplug, enabled_irqs;

        if (HAS_PCH_IBX(dev)) {
                hotplug_irqs = SDE_HOTPLUG_MASK;
                enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_ibx);
        } else {
                hotplug_irqs = SDE_HOTPLUG_MASK_CPT;
                enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_cpt);
        }

        ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);

        /*
         * Enable digital hotplug on the PCH, and configure the DP short pulse
         * duration to 2ms (which is the minimum in the Display Port spec).
         * The pulse duration bits are reserved on LPT+.
         */
        hotplug = I915_READ(PCH_PORT_HOTPLUG);
        hotplug &= ~(PORTD_PULSE_DURATION_MASK|PORTC_PULSE_DURATION_MASK|PORTB_PULSE_DURATION_MASK);
        hotplug |= PORTD_HOTPLUG_ENABLE | PORTD_PULSE_DURATION_2ms;
        hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
        hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
        /*
         * When CPU and PCH are on the same package, port A
         * HPD must be enabled in both north and south.
         */
        if (HAS_PCH_LPT_LP(dev))
                hotplug |= PORTA_HOTPLUG_ENABLE;
        I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
}

static void spt_hpd_irq_setup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_irqs, hotplug, enabled_irqs;

        hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
        enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_spt);

        ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);

        /* Enable digital hotplug on the PCH */
        hotplug = I915_READ(PCH_PORT_HOTPLUG);
        hotplug |= PORTD_HOTPLUG_ENABLE | PORTC_HOTPLUG_ENABLE |
                PORTB_HOTPLUG_ENABLE | PORTA_HOTPLUG_ENABLE;
        I915_WRITE(PCH_PORT_HOTPLUG, hotplug);

        hotplug = I915_READ(PCH_PORT_HOTPLUG2);
        hotplug |= PORTE_HOTPLUG_ENABLE;
        I915_WRITE(PCH_PORT_HOTPLUG2, hotplug);
}

static void ilk_hpd_irq_setup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_irqs, hotplug, enabled_irqs;

        if (INTEL_INFO(dev)->gen >= 8) {
                hotplug_irqs = GEN8_PORT_DP_A_HOTPLUG;
                enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_bdw);

                bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);
        } else if (INTEL_INFO(dev)->gen >= 7) {
                hotplug_irqs = DE_DP_A_HOTPLUG_IVB;
                enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_ivb);

                ilk_update_display_irq(dev_priv, hotplug_irqs, enabled_irqs);
        } else {
                hotplug_irqs = DE_DP_A_HOTPLUG;
                enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_ilk);

                ilk_update_display_irq(dev_priv, hotplug_irqs, enabled_irqs);
        }

        /*
         * Enable digital hotplug on the CPU, and configure the DP short pulse
         * duration to 2ms (which is the minimum in the Display Port spec)
         * The pulse duration bits are reserved on HSW+.
         */
        hotplug = I915_READ(DIGITAL_PORT_HOTPLUG_CNTRL);
        hotplug &= ~DIGITAL_PORTA_PULSE_DURATION_MASK;
        hotplug |= DIGITAL_PORTA_HOTPLUG_ENABLE | DIGITAL_PORTA_PULSE_DURATION_2ms;
        I915_WRITE(DIGITAL_PORT_HOTPLUG_CNTRL, hotplug);

        ibx_hpd_irq_setup(dev);
}

static void bxt_hpd_irq_setup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_irqs, hotplug, enabled_irqs;

        enabled_irqs = intel_hpd_enabled_irqs(dev, hpd_bxt);
        hotplug_irqs = BXT_DE_PORT_HOTPLUG_MASK;

        bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);

        hotplug = I915_READ(PCH_PORT_HOTPLUG);
        hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
                PORTA_HOTPLUG_ENABLE;
        I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
}

static void ibx_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 mask;

        if (HAS_PCH_NOP(dev))
                return;

        if (HAS_PCH_IBX(dev))
                mask = SDE_GMBUS | SDE_AUX_MASK | SDE_POISON;
        else
                mask = SDE_GMBUS_CPT | SDE_AUX_MASK_CPT;

        GEN5_ASSERT_IIR_IS_ZERO(SDEIIR);
        I915_WRITE(SDEIMR, ~mask);
}

static void gen5_gt_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pm_irqs, gt_irqs;

        pm_irqs = gt_irqs = 0;

        dev_priv->gt_irq_mask = ~0;
        if (HAS_L3_DPF(dev)) {
                /* L3 parity interrupt is always unmasked. */
                dev_priv->gt_irq_mask = ~GT_PARITY_ERROR(dev);
                gt_irqs |= GT_PARITY_ERROR(dev);
        }

        gt_irqs |= GT_RENDER_USER_INTERRUPT;
        if (IS_GEN5(dev)) {
                gt_irqs |= GT_RENDER_PIPECTL_NOTIFY_INTERRUPT |
                           ILK_BSD_USER_INTERRUPT;
        } else {
                gt_irqs |= GT_BLT_USER_INTERRUPT | GT_BSD_USER_INTERRUPT;
        }

        GEN5_IRQ_INIT(GT, dev_priv->gt_irq_mask, gt_irqs);

        if (INTEL_INFO(dev)->gen >= 6) {
                /*
                 * RPS interrupts will get enabled/disabled on demand when RPS
                 * itself is enabled/disabled.
                 */
                if (HAS_VEBOX(dev))
                        pm_irqs |= PM_VEBOX_USER_INTERRUPT;

                dev_priv->pm_irq_mask = 0xffffffff;
                GEN5_IRQ_INIT(GEN6_PM, dev_priv->pm_irq_mask, pm_irqs);
        }
}

static int ironlake_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 display_mask, extra_mask;

        if (INTEL_INFO(dev)->gen >= 7) {
                display_mask = (DE_MASTER_IRQ_CONTROL | DE_GSE_IVB |
                                DE_PCH_EVENT_IVB | DE_PLANEC_FLIP_DONE_IVB |
                                DE_PLANEB_FLIP_DONE_IVB |
                                DE_PLANEA_FLIP_DONE_IVB | DE_AUX_CHANNEL_A_IVB);
                extra_mask = (DE_PIPEC_VBLANK_IVB | DE_PIPEB_VBLANK_IVB |
                              DE_PIPEA_VBLANK_IVB | DE_ERR_INT_IVB |
                              DE_DP_A_HOTPLUG_IVB);
        } else {
                display_mask = (DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT |
                                DE_PLANEA_FLIP_DONE | DE_PLANEB_FLIP_DONE |
                                DE_AUX_CHANNEL_A |
                                DE_PIPEB_CRC_DONE | DE_PIPEA_CRC_DONE |
                                DE_POISON);
                extra_mask = (DE_PIPEA_VBLANK | DE_PIPEB_VBLANK | DE_PCU_EVENT |
                              DE_PIPEB_FIFO_UNDERRUN | DE_PIPEA_FIFO_UNDERRUN |
                              DE_DP_A_HOTPLUG);
        }

        dev_priv->irq_mask = ~display_mask;

        I915_WRITE(HWSTAM, 0xeffe);

        ibx_irq_pre_postinstall(dev);

        GEN5_IRQ_INIT(DE, dev_priv->irq_mask, display_mask | extra_mask);

        gen5_gt_irq_postinstall(dev);

        ibx_irq_postinstall(dev);

        if (IS_IRONLAKE_M(dev)) {
                /* Enable PCU event interrupts
                 *
                 * spinlocking not required here for correctness since interrupt
                 * setup is guaranteed to run in single-threaded context. But we
                 * need it to make the assert_spin_locked happy. */
                spin_lock_irq(&dev_priv->irq_lock);
                ironlake_enable_display_irq(dev_priv, DE_PCU_EVENT);
                spin_unlock_irq(&dev_priv->irq_lock);
        }

        return 0;
}

static void valleyview_display_irqs_install(struct drm_i915_private *dev_priv)
{
        u32 pipestat_mask;
        u32 iir_mask;
        enum pipe pipe;

        pipestat_mask = PIPESTAT_INT_STATUS_MASK |
                        PIPE_FIFO_UNDERRUN_STATUS;

        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), pipestat_mask);
        POSTING_READ(PIPESTAT(PIPE_A));

        pipestat_mask = PLANE_FLIP_DONE_INT_STATUS_VLV |
                        PIPE_CRC_DONE_INTERRUPT_STATUS;

        i915_enable_pipestat(dev_priv, PIPE_A, PIPE_GMBUS_INTERRUPT_STATUS);
        for_each_pipe(dev_priv, pipe)
                      i915_enable_pipestat(dev_priv, pipe, pipestat_mask);

        iir_mask = I915_DISPLAY_PORT_INTERRUPT |
                   I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                   I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
        if (IS_CHERRYVIEW(dev_priv))
                iir_mask |= I915_DISPLAY_PIPE_C_EVENT_INTERRUPT;
        dev_priv->irq_mask &= ~iir_mask;

        I915_WRITE(VLV_IIR, iir_mask);
        I915_WRITE(VLV_IIR, iir_mask);
        I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
        I915_WRITE(VLV_IMR, dev_priv->irq_mask);
        POSTING_READ(VLV_IMR);
}

static void valleyview_display_irqs_uninstall(struct drm_i915_private *dev_priv)
{
        u32 pipestat_mask;
        u32 iir_mask;
        enum pipe pipe;

        iir_mask = I915_DISPLAY_PORT_INTERRUPT |
                   I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                   I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
        if (IS_CHERRYVIEW(dev_priv))
                iir_mask |= I915_DISPLAY_PIPE_C_EVENT_INTERRUPT;

        dev_priv->irq_mask |= iir_mask;
        I915_WRITE(VLV_IMR, dev_priv->irq_mask);
        I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
        I915_WRITE(VLV_IIR, iir_mask);
        I915_WRITE(VLV_IIR, iir_mask);
        POSTING_READ(VLV_IIR);

        pipestat_mask = PLANE_FLIP_DONE_INT_STATUS_VLV |
                        PIPE_CRC_DONE_INTERRUPT_STATUS;

        i915_disable_pipestat(dev_priv, PIPE_A, PIPE_GMBUS_INTERRUPT_STATUS);
        for_each_pipe(dev_priv, pipe)
                i915_disable_pipestat(dev_priv, pipe, pipestat_mask);

        pipestat_mask = PIPESTAT_INT_STATUS_MASK |
                        PIPE_FIFO_UNDERRUN_STATUS;

        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), pipestat_mask);
        POSTING_READ(PIPESTAT(PIPE_A));
}

void valleyview_enable_display_irqs(struct drm_i915_private *dev_priv)
{
        assert_spin_locked(&dev_priv->irq_lock);

        if (dev_priv->display_irqs_enabled)
                return;

        dev_priv->display_irqs_enabled = true;

        if (intel_irqs_enabled(dev_priv))
                valleyview_display_irqs_install(dev_priv);
}

void valleyview_disable_display_irqs(struct drm_i915_private *dev_priv)
{
        assert_spin_locked(&dev_priv->irq_lock);

        if (!dev_priv->display_irqs_enabled)
                return;

        dev_priv->display_irqs_enabled = false;

        if (intel_irqs_enabled(dev_priv))
                valleyview_display_irqs_uninstall(dev_priv);
}

static void vlv_display_irq_postinstall(struct drm_i915_private *dev_priv)
{
        dev_priv->irq_mask = ~0;

        i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
        POSTING_READ(PORT_HOTPLUG_EN);

        I915_WRITE(VLV_IIR, 0xffffffff);
        I915_WRITE(VLV_IIR, 0xffffffff);
        I915_WRITE(VLV_IER, ~dev_priv->irq_mask);
        I915_WRITE(VLV_IMR, dev_priv->irq_mask);
        POSTING_READ(VLV_IMR);

        /* Interrupt setup is already guaranteed to be single-threaded, this is
         * just to make the assert_spin_locked check happy. */
        spin_lock_irq(&dev_priv->irq_lock);
        if (dev_priv->display_irqs_enabled)
                valleyview_display_irqs_install(dev_priv);
        spin_unlock_irq(&dev_priv->irq_lock);
}

static int valleyview_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        vlv_display_irq_postinstall(dev_priv);

        gen5_gt_irq_postinstall(dev);

        /* ack & enable invalid PTE error interrupts */
#if 0 /* FIXME: add support to irq handler for checking these bits */
        I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);
        I915_WRITE(DPINVGTT, DPINVGTT_EN_MASK);
#endif

        I915_WRITE(VLV_MASTER_IER, MASTER_INTERRUPT_ENABLE);

        return 0;
}

static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
{
        /* These are interrupts we'll toggle with the ring mask register */
        uint32_t gt_interrupts[] = {
                GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
                        GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
                        GT_RENDER_L3_PARITY_ERROR_INTERRUPT |
                        GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT |
                        GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT,
                GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT |
                        GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT |
                        GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT |
                        GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT,
                0,
                GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT |
                        GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT
                };

        dev_priv->pm_irq_mask = 0xffffffff;
        GEN8_IRQ_INIT_NDX(GT, 0, ~gt_interrupts[0], gt_interrupts[0]);
        GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
        /*
         * RPS interrupts will get enabled/disabled on demand when RPS itself
         * is enabled/disabled.
         */
        GEN8_IRQ_INIT_NDX(GT, 2, dev_priv->pm_irq_mask, 0);
        GEN8_IRQ_INIT_NDX(GT, 3, ~gt_interrupts[3], gt_interrupts[3]);
}

static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
{
        uint32_t de_pipe_masked = GEN8_PIPE_CDCLK_CRC_DONE;
        uint32_t de_pipe_enables;
        u32 de_port_masked = GEN8_AUX_CHANNEL_A;
        u32 de_port_enables;
        enum pipe pipe;

        if (INTEL_INFO(dev_priv)->gen >= 9) {
                de_pipe_masked |= GEN9_PIPE_PLANE1_FLIP_DONE |
                                  GEN9_DE_PIPE_IRQ_FAULT_ERRORS;
                de_port_masked |= GEN9_AUX_CHANNEL_B | GEN9_AUX_CHANNEL_C |
                                  GEN9_AUX_CHANNEL_D;
                if (IS_BROXTON(dev_priv))
                        de_port_masked |= BXT_DE_PORT_GMBUS;
        } else {
                de_pipe_masked |= GEN8_PIPE_PRIMARY_FLIP_DONE |
                                  GEN8_DE_PIPE_IRQ_FAULT_ERRORS;
        }

        de_pipe_enables = de_pipe_masked | GEN8_PIPE_VBLANK |
                                           GEN8_PIPE_FIFO_UNDERRUN;

        de_port_enables = de_port_masked;
        if (IS_BROXTON(dev_priv))
                de_port_enables |= BXT_DE_PORT_HOTPLUG_MASK;
        else if (IS_BROADWELL(dev_priv))
                de_port_enables |= GEN8_PORT_DP_A_HOTPLUG;

        dev_priv->de_irq_mask[PIPE_A] = ~de_pipe_masked;
        dev_priv->de_irq_mask[PIPE_B] = ~de_pipe_masked;
        dev_priv->de_irq_mask[PIPE_C] = ~de_pipe_masked;

        for_each_pipe(dev_priv, pipe)
                if (intel_display_power_is_enabled(dev_priv,
                                POWER_DOMAIN_PIPE(pipe)))
                        GEN8_IRQ_INIT_NDX(DE_PIPE, pipe,
                                          dev_priv->de_irq_mask[pipe],
                                          de_pipe_enables);

        GEN5_IRQ_INIT(GEN8_DE_PORT_, ~de_port_masked, de_port_enables);
}

static int gen8_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (HAS_PCH_SPLIT(dev))
                ibx_irq_pre_postinstall(dev);

        gen8_gt_irq_postinstall(dev_priv);
        gen8_de_irq_postinstall(dev_priv);

        if (HAS_PCH_SPLIT(dev))
                ibx_irq_postinstall(dev);

        I915_WRITE(GEN8_MASTER_IRQ, DE_MASTER_IRQ_CONTROL);
        POSTING_READ(GEN8_MASTER_IRQ);

        return 0;
}

static int cherryview_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        vlv_display_irq_postinstall(dev_priv);

        gen8_gt_irq_postinstall(dev_priv);

        I915_WRITE(GEN8_MASTER_IRQ, MASTER_INTERRUPT_ENABLE);
        POSTING_READ(GEN8_MASTER_IRQ);

        return 0;
}

static void gen8_irq_uninstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv)
                return;

        gen8_irq_reset(dev);
}

static void vlv_display_irq_uninstall(struct drm_i915_private *dev_priv)
{
        /* Interrupt setup is already guaranteed to be single-threaded, this is
         * just to make the assert_spin_locked check happy. */
        spin_lock_irq(&dev_priv->irq_lock);
        if (dev_priv->display_irqs_enabled)
                valleyview_display_irqs_uninstall(dev_priv);
        spin_unlock_irq(&dev_priv->irq_lock);

        vlv_display_irq_reset(dev_priv);

        dev_priv->irq_mask = ~0;
}

static void valleyview_irq_uninstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv)
                return;

        I915_WRITE(VLV_MASTER_IER, 0);

        gen5_gt_irq_reset(dev);

        I915_WRITE(HWSTAM, 0xffffffff);

        vlv_display_irq_uninstall(dev_priv);
}

static void cherryview_irq_uninstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv)
                return;

        I915_WRITE(GEN8_MASTER_IRQ, 0);
        POSTING_READ(GEN8_MASTER_IRQ);

        gen8_gt_irq_reset(dev_priv);

        GEN5_IRQ_RESET(GEN8_PCU_);

        vlv_display_irq_uninstall(dev_priv);
}

static void ironlake_irq_uninstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!dev_priv)
                return;

        ironlake_irq_reset(dev);
}

static void i8xx_irq_preinstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), 0);
        I915_WRITE16(IMR, 0xffff);
        I915_WRITE16(IER, 0x0);
        POSTING_READ16(IER);
}

static int i8xx_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        I915_WRITE16(EMR,
                     ~(I915_ERROR_PAGE_TABLE | I915_ERROR_MEMORY_REFRESH));

        /* Unmask the interrupts that we always want on. */
        dev_priv->irq_mask =
                ~(I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
                  I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                  I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT);
        I915_WRITE16(IMR, dev_priv->irq_mask);

        I915_WRITE16(IER,
                     I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                     I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
                     I915_USER_INTERRUPT);
        POSTING_READ16(IER);

        /* Interrupt setup is already guaranteed to be single-threaded, this is
         * just to make the assert_spin_locked check happy. */
        spin_lock_irq(&dev_priv->irq_lock);
        i915_enable_pipestat(dev_priv, PIPE_A, PIPE_CRC_DONE_INTERRUPT_STATUS);
        i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
        spin_unlock_irq(&dev_priv->irq_lock);

        return 0;
}

/*
 * Returns true when a page flip has completed.
 */
static bool i8xx_handle_vblank(struct drm_device *dev,
                               int plane, int pipe, u32 iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u16 flip_pending = DISPLAY_PLANE_FLIP_PENDING(plane);

        if (!intel_pipe_handle_vblank(dev, pipe))
                return false;

        if ((iir & flip_pending) == 0)
                goto check_page_flip;

        /* We detect FlipDone by looking for the change in PendingFlip from '1'
         * to '0' on the following vblank, i.e. IIR has the Pendingflip
         * asserted following the MI_DISPLAY_FLIP, but ISR is deasserted, hence
         * the flip is completed (no longer pending). Since this doesn't raise
         * an interrupt per se, we watch for the change at vblank.
         */
        if (I915_READ16(ISR) & flip_pending)
                goto check_page_flip;

        intel_prepare_page_flip(dev, plane);
        intel_finish_page_flip(dev, pipe);
        return true;

check_page_flip:
        intel_check_page_flip(dev, pipe);
        return false;
}

static irqreturn_t i8xx_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u16 iir, new_iir;
        u32 pipe_stats[2];
        int pipe;
        u16 flip_mask =
                I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        iir = I915_READ16(IIR);
        if (iir == 0)
                return IRQ_NONE;

        while (iir & ~flip_mask) {
                /* Can't rely on pipestat interrupt bit in iir as it might
                 * have been cleared after the pipestat interrupt was received.
                 * It doesn't set the bit in iir again, but it still produces
                 * interrupts (for non-MSI).
                 */
                spin_lock(&dev_priv->irq_lock);
                if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
                        DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);

                for_each_pipe(dev_priv, pipe) {
                        int reg = PIPESTAT(pipe);
                        pipe_stats[pipe] = I915_READ(reg);

                        /*
                         * Clear the PIPE*STAT regs before the IIR
                         */
                        if (pipe_stats[pipe] & 0x8000ffff)
                                I915_WRITE(reg, pipe_stats[pipe]);
                }
                spin_unlock(&dev_priv->irq_lock);

                I915_WRITE16(IIR, iir & ~flip_mask);
                new_iir = I915_READ16(IIR); /* Flush posted writes */

                if (iir & I915_USER_INTERRUPT)
                        notify_ring(&dev_priv->ring[RCS]);

                for_each_pipe(dev_priv, pipe) {
                        int plane = pipe;
                        if (HAS_FBC(dev))
                                plane = !plane;

                        if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS &&
                            i8xx_handle_vblank(dev, plane, pipe, iir))
                                flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(plane);

                        if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
                                i9xx_pipe_crc_irq_handler(dev, pipe);

                        if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
                                intel_cpu_fifo_underrun_irq_handler(dev_priv,
                                                                    pipe);
                }

                iir = new_iir;
        }

        return IRQ_HANDLED;
}

static void i8xx_irq_uninstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        for_each_pipe(dev_priv, pipe) {
                /* Clear enable bits; then clear status bits */
                I915_WRITE(PIPESTAT(pipe), 0);
                I915_WRITE(PIPESTAT(pipe), I915_READ(PIPESTAT(pipe)));
        }
        I915_WRITE16(IMR, 0xffff);
        I915_WRITE16(IER, 0x0);
        I915_WRITE16(IIR, I915_READ16(IIR));
}

static void i915_irq_preinstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        if (I915_HAS_HOTPLUG(dev)) {
                i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
                I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
        }

        I915_WRITE16(HWSTAM, 0xeffe);
        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), 0);
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);
        POSTING_READ(IER);
}

static int i915_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 enable_mask;

        I915_WRITE(EMR, ~(I915_ERROR_PAGE_TABLE | I915_ERROR_MEMORY_REFRESH));

        /* Unmask the interrupts that we always want on. */
        dev_priv->irq_mask =
                ~(I915_ASLE_INTERRUPT |
                  I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
                  I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                  I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT);

        enable_mask =
                I915_ASLE_INTERRUPT |
                I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
                I915_USER_INTERRUPT;

        if (I915_HAS_HOTPLUG(dev)) {
                i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
                POSTING_READ(PORT_HOTPLUG_EN);

                /* Enable in IER... */
                enable_mask |= I915_DISPLAY_PORT_INTERRUPT;
                /* and unmask in IMR */
                dev_priv->irq_mask &= ~I915_DISPLAY_PORT_INTERRUPT;
        }

        I915_WRITE(IMR, dev_priv->irq_mask);
        I915_WRITE(IER, enable_mask);
        POSTING_READ(IER);

        i915_enable_asle_pipestat(dev);

        /* Interrupt setup is already guaranteed to be single-threaded, this is
         * just to make the assert_spin_locked check happy. */
        spin_lock_irq(&dev_priv->irq_lock);
        i915_enable_pipestat(dev_priv, PIPE_A, PIPE_CRC_DONE_INTERRUPT_STATUS);
        i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
        spin_unlock_irq(&dev_priv->irq_lock);

        return 0;
}

/*
 * Returns true when a page flip has completed.
 */
static bool i915_handle_vblank(struct drm_device *dev,
                               int plane, int pipe, u32 iir)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 flip_pending = DISPLAY_PLANE_FLIP_PENDING(plane);

        if (!intel_pipe_handle_vblank(dev, pipe))
                return false;

        if ((iir & flip_pending) == 0)
                goto check_page_flip;

        /* We detect FlipDone by looking for the change in PendingFlip from '1'
         * to '0' on the following vblank, i.e. IIR has the Pendingflip
         * asserted following the MI_DISPLAY_FLIP, but ISR is deasserted, hence
         * the flip is completed (no longer pending). Since this doesn't raise
         * an interrupt per se, we watch for the change at vblank.
         */
        if (I915_READ(ISR) & flip_pending)
                goto check_page_flip;

        intel_prepare_page_flip(dev, plane);
        intel_finish_page_flip(dev, pipe);
        return true;

check_page_flip:
        intel_check_page_flip(dev, pipe);
        return false;
}

static irqreturn_t i915_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 iir, new_iir, pipe_stats[I915_MAX_PIPES];
        u32 flip_mask =
                I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
        int pipe, ret = IRQ_NONE;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        iir = I915_READ(IIR);
        do {
                bool irq_received = (iir & ~flip_mask) != 0;
                bool blc_event = false;

                /* Can't rely on pipestat interrupt bit in iir as it might
                 * have been cleared after the pipestat interrupt was received.
                 * It doesn't set the bit in iir again, but it still produces
                 * interrupts (for non-MSI).
                 */
                spin_lock(&dev_priv->irq_lock);
                if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
                        DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);

                for_each_pipe(dev_priv, pipe) {
                        int reg = PIPESTAT(pipe);
                        pipe_stats[pipe] = I915_READ(reg);

                        /* Clear the PIPE*STAT regs before the IIR */
                        if (pipe_stats[pipe] & 0x8000ffff) {
                                I915_WRITE(reg, pipe_stats[pipe]);
                                irq_received = true;
                        }
                }
                spin_unlock(&dev_priv->irq_lock);

                if (!irq_received)
                        break;

                /* Consume port.  Then clear IIR or we'll miss events */
                if (I915_HAS_HOTPLUG(dev) &&
                    iir & I915_DISPLAY_PORT_INTERRUPT)
                        i9xx_hpd_irq_handler(dev);

                I915_WRITE(IIR, iir & ~flip_mask);
                new_iir = I915_READ(IIR); /* Flush posted writes */

                if (iir & I915_USER_INTERRUPT)
                        notify_ring(&dev_priv->ring[RCS]);

                for_each_pipe(dev_priv, pipe) {
                        int plane = pipe;
                        if (HAS_FBC(dev))
                                plane = !plane;

                        if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS &&
                            i915_handle_vblank(dev, plane, pipe, iir))
                                flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(plane);

                        if (pipe_stats[pipe] & PIPE_LEGACY_BLC_EVENT_STATUS)
                                blc_event = true;

                        if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
                                i9xx_pipe_crc_irq_handler(dev, pipe);

                        if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
                                intel_cpu_fifo_underrun_irq_handler(dev_priv,
                                                                    pipe);
                }

                if (blc_event || (iir & I915_ASLE_INTERRUPT))
                        intel_opregion_asle_intr(dev);

                /* With MSI, interrupts are only generated when iir
                 * transitions from zero to nonzero.  If another bit got
                 * set while we were handling the existing iir bits, then
                 * we would never get another interrupt.
                 *
                 * This is fine on non-MSI as well, as if we hit this path
                 * we avoid exiting the interrupt handler only to generate
                 * another one.
                 *
                 * Note that for MSI this could cause a stray interrupt report
                 * if an interrupt landed in the time between writing IIR and
                 * the posting read.  This should be rare enough to never
                 * trigger the 99% of 100,000 interrupts test for disabling
                 * stray interrupts.
                 */
                ret = IRQ_HANDLED;
                iir = new_iir;
        } while (iir & ~flip_mask);

        return ret;
}

static void i915_irq_uninstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        if (I915_HAS_HOTPLUG(dev)) {
                i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
                I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
        }

        I915_WRITE16(HWSTAM, 0xffff);
        for_each_pipe(dev_priv, pipe) {
                /* Clear enable bits; then clear status bits */
                I915_WRITE(PIPESTAT(pipe), 0);
                I915_WRITE(PIPESTAT(pipe), I915_READ(PIPESTAT(pipe)));
        }
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);

        I915_WRITE(IIR, I915_READ(IIR));
}

static void i965_irq_preinstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
        I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));

        I915_WRITE(HWSTAM, 0xeffe);
        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), 0);
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);
        POSTING_READ(IER);
}

static int i965_irq_postinstall(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 enable_mask;
        u32 error_mask;

        /* Unmask the interrupts that we always want on. */
        dev_priv->irq_mask = ~(I915_ASLE_INTERRUPT |
                               I915_DISPLAY_PORT_INTERRUPT |
                               I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
                               I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
                               I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                               I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT |
                               I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);

        enable_mask = ~dev_priv->irq_mask;
        enable_mask &= ~(I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                         I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT);
        enable_mask |= I915_USER_INTERRUPT;

        if (IS_G4X(dev))
                enable_mask |= I915_BSD_USER_INTERRUPT;

        /* Interrupt setup is already guaranteed to be single-threaded, this is
         * just to make the assert_spin_locked check happy. */
        spin_lock_irq(&dev_priv->irq_lock);
        i915_enable_pipestat(dev_priv, PIPE_A, PIPE_GMBUS_INTERRUPT_STATUS);
        i915_enable_pipestat(dev_priv, PIPE_A, PIPE_CRC_DONE_INTERRUPT_STATUS);
        i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
        spin_unlock_irq(&dev_priv->irq_lock);

        /*
         * Enable some error detection, note the instruction error mask
         * bit is reserved, so we leave it masked.
         */
        if (IS_G4X(dev)) {
                error_mask = ~(GM45_ERROR_PAGE_TABLE |
                               GM45_ERROR_MEM_PRIV |
                               GM45_ERROR_CP_PRIV |
                               I915_ERROR_MEMORY_REFRESH);
        } else {
                error_mask = ~(I915_ERROR_PAGE_TABLE |
                               I915_ERROR_MEMORY_REFRESH);
        }
        I915_WRITE(EMR, error_mask);

        I915_WRITE(IMR, dev_priv->irq_mask);
        I915_WRITE(IER, enable_mask);
        POSTING_READ(IER);

        i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
        POSTING_READ(PORT_HOTPLUG_EN);

        i915_enable_asle_pipestat(dev);

        return 0;
}

static void i915_hpd_irq_setup(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 hotplug_en;

        assert_spin_locked(&dev_priv->irq_lock);

        /* Note HDMI and DP share hotplug bits */
        /* enable bits are the same for all generations */
        hotplug_en = intel_hpd_enabled_irqs(dev, hpd_mask_i915);
        /* Programming the CRT detection parameters tends
           to generate a spurious hotplug event about three
           seconds later.  So just do it once.
        */
        if (IS_G4X(dev))
                hotplug_en |= CRT_HOTPLUG_ACTIVATION_PERIOD_64;
        hotplug_en |= CRT_HOTPLUG_VOLTAGE_COMPARE_50;

        /* Ignore TV since it's buggy */
        i915_hotplug_interrupt_update_locked(dev_priv,
                                      (HOTPLUG_INT_EN_MASK
                                       | CRT_HOTPLUG_VOLTAGE_COMPARE_MASK),
                                      hotplug_en);
}

static irqreturn_t i965_irq_handler(int irq, void *arg)
{
        struct drm_device *dev = arg;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 iir, new_iir;
        u32 pipe_stats[I915_MAX_PIPES];
        int ret = IRQ_NONE, pipe;
        u32 flip_mask =
                I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
                I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;

        if (!intel_irqs_enabled(dev_priv))
                return IRQ_NONE;

        iir = I915_READ(IIR);

        for (;;) {
                bool irq_received = (iir & ~flip_mask) != 0;
                bool blc_event = false;

                /* Can't rely on pipestat interrupt bit in iir as it might
                 * have been cleared after the pipestat interrupt was received.
                 * It doesn't set the bit in iir again, but it still produces
                 * interrupts (for non-MSI).
                 */
                spin_lock(&dev_priv->irq_lock);
                if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
                        DRM_DEBUG("Command parser error, iir 0x%08x\n", iir);

                for_each_pipe(dev_priv, pipe) {
                        int reg = PIPESTAT(pipe);
                        pipe_stats[pipe] = I915_READ(reg);

                        /*
                         * Clear the PIPE*STAT regs before the IIR
                         */
                        if (pipe_stats[pipe] & 0x8000ffff) {
                                I915_WRITE(reg, pipe_stats[pipe]);
                                irq_received = true;
                        }
                }
                spin_unlock(&dev_priv->irq_lock);

                if (!irq_received)
                        break;

                ret = IRQ_HANDLED;

                /* Consume port.  Then clear IIR or we'll miss events */
                if (iir & I915_DISPLAY_PORT_INTERRUPT)
                        i9xx_hpd_irq_handler(dev);

                I915_WRITE(IIR, iir & ~flip_mask);
                new_iir = I915_READ(IIR); /* Flush posted writes */

                if (iir & I915_USER_INTERRUPT)
                        notify_ring(&dev_priv->ring[RCS]);
                if (iir & I915_BSD_USER_INTERRUPT)
                        notify_ring(&dev_priv->ring[VCS]);

                for_each_pipe(dev_priv, pipe) {
                        if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS &&
                            i915_handle_vblank(dev, pipe, pipe, iir))
                                flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(pipe);

                        if (pipe_stats[pipe] & PIPE_LEGACY_BLC_EVENT_STATUS)
                                blc_event = true;

                        if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
                                i9xx_pipe_crc_irq_handler(dev, pipe);

                        if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
                                intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
                }

                if (blc_event || (iir & I915_ASLE_INTERRUPT))
                        intel_opregion_asle_intr(dev);

                if (pipe_stats[0] & PIPE_GMBUS_INTERRUPT_STATUS)
                        gmbus_irq_handler(dev);

                /* With MSI, interrupts are only generated when iir
                 * transitions from zero to nonzero.  If another bit got
                 * set while we were handling the existing iir bits, then
                 * we would never get another interrupt.
                 *
                 * This is fine on non-MSI as well, as if we hit this path
                 * we avoid exiting the interrupt handler only to generate
                 * another one.
                 *
                 * Note that for MSI this could cause a stray interrupt report
                 * if an interrupt landed in the time between writing IIR and
                 * the posting read.  This should be rare enough to never
                 * trigger the 99% of 100,000 interrupts test for disabling
                 * stray interrupts.
                 */
                iir = new_iir;
        }

        return ret;
}

static void i965_irq_uninstall(struct drm_device * dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int pipe;

        if (!dev_priv)
                return;

        i915_hotplug_interrupt_update(dev_priv, 0xffffffff, 0);
        I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));

        I915_WRITE(HWSTAM, 0xffffffff);
        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe), 0);
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);

        for_each_pipe(dev_priv, pipe)
                I915_WRITE(PIPESTAT(pipe),
                           I915_READ(PIPESTAT(pipe)) & 0x8000ffff);
        I915_WRITE(IIR, I915_READ(IIR));
}

/**
 * intel_irq_init - initializes irq support
 * @dev_priv: i915 device instance
 *
 * This function initializes all the irq support including work items, timers
 * and all the vtables. It does not setup the interrupt itself though.
 */
void intel_irq_init(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;

        intel_hpd_init_work(dev_priv);

        INIT_WORK(&dev_priv->rps.work, gen6_pm_rps_work);
        INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);

        /* Let's track the enabled rps events */
        if (IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv))
                /* WaGsvRC0ResidencyMethod:vlv */
                dev_priv->pm_rps_events = GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED;
        else
                dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;

        INIT_DELAYED_WORK(&dev_priv->gpu_error.hangcheck_work,
                          i915_hangcheck_elapsed);

        pm_qos_add_request(&dev_priv->pm_qos, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE);

        if (IS_GEN2(dev_priv)) {
                dev->max_vblank_count = 0;
                dev->driver->get_vblank_counter = i8xx_get_vblank_counter;
        } else if (IS_G4X(dev_priv) || INTEL_INFO(dev_priv)->gen >= 5) {
                dev->max_vblank_count = 0xffffffff; /* full 32 bit counter */
                dev->driver->get_vblank_counter = gm45_get_vblank_counter;
        } else {
                dev->driver->get_vblank_counter = i915_get_vblank_counter;
                dev->max_vblank_count = 0xffffff; /* only 24 bits of frame count */
        }

        /*
         * Opt out of the vblank disable timer on everything except gen2.
         * Gen2 doesn't have a hardware frame counter and so depends on
         * vblank interrupts to produce sane vblank seuquence numbers.
         */
        if (!IS_GEN2(dev_priv))
                dev->vblank_disable_immediate = true;

        dev->driver->get_vblank_timestamp = i915_get_vblank_timestamp;
        dev->driver->get_scanout_position = i915_get_crtc_scanoutpos;

        if (IS_CHERRYVIEW(dev_priv)) {
                dev->driver->irq_handler = cherryview_irq_handler;
                dev->driver->irq_preinstall = cherryview_irq_preinstall;
                dev->driver->irq_postinstall = cherryview_irq_postinstall;
                dev->driver->irq_uninstall = cherryview_irq_uninstall;
                dev->driver->enable_vblank = valleyview_enable_vblank;
                dev->driver->disable_vblank = valleyview_disable_vblank;
                dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
        } else if (IS_VALLEYVIEW(dev_priv)) {
                dev->driver->irq_handler = valleyview_irq_handler;
                dev->driver->irq_preinstall = valleyview_irq_preinstall;
                dev->driver->irq_postinstall = valleyview_irq_postinstall;
                dev->driver->irq_uninstall = valleyview_irq_uninstall;
                dev->driver->enable_vblank = valleyview_enable_vblank;
                dev->driver->disable_vblank = valleyview_disable_vblank;
                dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
        } else if (INTEL_INFO(dev_priv)->gen >= 8) {
                dev->driver->irq_handler = gen8_irq_handler;
                dev->driver->irq_preinstall = gen8_irq_reset;
                dev->driver->irq_postinstall = gen8_irq_postinstall;
                dev->driver->irq_uninstall = gen8_irq_uninstall;
                dev->driver->enable_vblank = gen8_enable_vblank;
                dev->driver->disable_vblank = gen8_disable_vblank;
                if (IS_BROXTON(dev))
                        dev_priv->display.hpd_irq_setup = bxt_hpd_irq_setup;
                else if (HAS_PCH_SPT(dev))
                        dev_priv->display.hpd_irq_setup = spt_hpd_irq_setup;
                else
                        dev_priv->display.hpd_irq_setup = ilk_hpd_irq_setup;
        } else if (HAS_PCH_SPLIT(dev)) {
                dev->driver->irq_handler = ironlake_irq_handler;
                dev->driver->irq_preinstall = ironlake_irq_reset;
                dev->driver->irq_postinstall = ironlake_irq_postinstall;
                dev->driver->irq_uninstall = ironlake_irq_uninstall;
                dev->driver->enable_vblank = ironlake_enable_vblank;
                dev->driver->disable_vblank = ironlake_disable_vblank;
                dev_priv->display.hpd_irq_setup = ilk_hpd_irq_setup;
        } else {
                if (INTEL_INFO(dev_priv)->gen == 2) {
                        dev->driver->irq_preinstall = i8xx_irq_preinstall;
                        dev->driver->irq_postinstall = i8xx_irq_postinstall;
                        dev->driver->irq_handler = i8xx_irq_handler;
                        dev->driver->irq_uninstall = i8xx_irq_uninstall;
                } else if (INTEL_INFO(dev_priv)->gen == 3) {
                        dev->driver->irq_preinstall = i915_irq_preinstall;
                        dev->driver->irq_postinstall = i915_irq_postinstall;
                        dev->driver->irq_uninstall = i915_irq_uninstall;
                        dev->driver->irq_handler = i915_irq_handler;
                } else {
                        dev->driver->irq_preinstall = i965_irq_preinstall;
                        dev->driver->irq_postinstall = i965_irq_postinstall;
                        dev->driver->irq_uninstall = i965_irq_uninstall;
                        dev->driver->irq_handler = i965_irq_handler;
                }
                if (I915_HAS_HOTPLUG(dev_priv))
                        dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
                dev->driver->enable_vblank = i915_enable_vblank;
                dev->driver->disable_vblank = i915_disable_vblank;
        }
}

/**
 * intel_irq_install - enables the hardware interrupt
 * @dev_priv: i915 device instance
 *
 * This function enables the hardware interrupt handling, but leaves the hotplug
 * handling still disabled. It is called after intel_irq_init().
 *
 * In the driver load and resume code we need working interrupts in a few places
 * but don't want to deal with the hassle of concurrent probe and hotplug
 * workers. Hence the split into this two-stage approach.
 */
int intel_irq_install(struct drm_i915_private *dev_priv)
{
        /*
         * We enable some interrupt sources in our postinstall hooks, so mark
         * interrupts as enabled _before_ actually enabling them to avoid
         * special cases in our ordering checks.
         */
        dev_priv->pm.irqs_enabled = true;

        return drm_irq_install(dev_priv->dev, dev_priv->dev->pdev->irq);
}

/**
 * intel_irq_uninstall - finilizes all irq handling
 * @dev_priv: i915 device instance
 *
 * This stops interrupt and hotplug handling and unregisters and frees all
 * resources acquired in the init functions.
 */
void intel_irq_uninstall(struct drm_i915_private *dev_priv)
{
        drm_irq_uninstall(dev_priv->dev);
        intel_hpd_cancel_work(dev_priv);
        dev_priv->pm.irqs_enabled = false;
}

/**
 * intel_runtime_pm_disable_interrupts - runtime interrupt disabling
 * @dev_priv: i915 device instance
 *
 * This function is used to disable interrupts at runtime, both in the runtime
 * pm and the system suspend/resume code.
 */
void intel_runtime_pm_disable_interrupts(struct drm_i915_private *dev_priv)
{
        dev_priv->dev->driver->irq_uninstall(dev_priv->dev);
        dev_priv->pm.irqs_enabled = false;
        synchronize_irq(dev_priv->dev->irq);
}

/**
 * intel_runtime_pm_enable_interrupts - runtime interrupt enabling
 * @dev_priv: i915 device instance
 *
 * This function is used to enable interrupts at runtime, both in the runtime
 * pm and the system suspend/resume code.
 */
void intel_runtime_pm_enable_interrupts(struct drm_i915_private *dev_priv)
{
        dev_priv->pm.irqs_enabled = true;
        dev_priv->dev->driver->irq_preinstall(dev_priv->dev);
        dev_priv->dev->driver->irq_postinstall(dev_priv->dev);
}