drm/i915: Make AGP support optional

[mirror_ubuntu-bionic-kernel.git] / drivers / char / agp / intel-gtt.c

/*
 * Intel GTT (Graphics Translation Table) routines
 *
 * Caveat: This driver implements the linux agp interface, but this is far from
 * a agp driver! GTT support ended up here for purely historical reasons: The
 * old userspace intel graphics drivers needed an interface to map memory into
 * the GTT. And the drm provides a default interface for graphic devices sitting
 * on an agp port. So it made sense to fake the GTT support as an agp port to
 * avoid having to create a new api.
 *
 * With gem this does not make much sense anymore, just needlessly complicates
 * the code. But as long as the old graphics stack is still support, it's stuck
 * here.
 *
 * /fairy-tale-mode off
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/agp_backend.h>
#include <linux/delay.h>
#include <asm/smp.h>
#include "agp.h"
#include "intel-agp.h"
#include <drm/intel-gtt.h>

/*
 * If we have Intel graphics, we're not going to have anything other than
 * an Intel IOMMU. So make the correct use of the PCI DMA API contingent
 * on the Intel IOMMU support (CONFIG_INTEL_IOMMU).
 * Only newer chipsets need to bother with this, of course.
 */
#ifdef CONFIG_INTEL_IOMMU
#define USE_PCI_DMA_API 1
#else
#define USE_PCI_DMA_API 0
#endif

struct intel_gtt_driver {
        unsigned int gen : 8;
        unsigned int is_g33 : 1;
        unsigned int is_pineview : 1;
        unsigned int is_ironlake : 1;
        unsigned int has_pgtbl_enable : 1;
        unsigned int dma_mask_size : 8;
        /* Chipset specific GTT setup */
        int (*setup)(void);
        /* This should undo anything done in ->setup() save the unmapping
         * of the mmio register file, that's done in the generic code. */
        void (*cleanup)(void);
        void (*write_entry)(dma_addr_t addr, unsigned int entry, unsigned int flags);
        /* Flags is a more or less chipset specific opaque value.
         * For chipsets that need to support old ums (non-gem) code, this
         * needs to be identical to the various supported agp memory types! */
        bool (*check_flags)(unsigned int flags);
        void (*chipset_flush)(void);
};

static struct _intel_private {
        const struct intel_gtt_driver *driver;
        struct pci_dev *pcidev; /* device one */
        struct pci_dev *bridge_dev;
        u8 __iomem *registers;
        phys_addr_t gtt_bus_addr;
        u32 PGETBL_save;
        u32 __iomem *gtt;               /* I915G */
        bool clear_fake_agp; /* on first access via agp, fill with scratch */
        int num_dcache_entries;
        void __iomem *i9xx_flush_page;
        char *i81x_gtt_table;
        struct resource ifp_resource;
        int resource_valid;
        struct page *scratch_page;
        phys_addr_t scratch_page_dma;
        int refcount;
        /* Whether i915 needs to use the dmar apis or not. */
        unsigned int needs_dmar : 1;
        phys_addr_t gma_bus_addr;
        /*  Size of memory reserved for graphics by the BIOS */
        unsigned int stolen_size;
        /* Total number of gtt entries. */
        unsigned int gtt_total_entries;
        /* Part of the gtt that is mappable by the cpu, for those chips where
         * this is not the full gtt. */
        unsigned int gtt_mappable_entries;
} intel_private;

#define INTEL_GTT_GEN   intel_private.driver->gen
#define IS_G33          intel_private.driver->is_g33
#define IS_PINEVIEW     intel_private.driver->is_pineview
#define IS_IRONLAKE     intel_private.driver->is_ironlake
#define HAS_PGTBL_EN    intel_private.driver->has_pgtbl_enable

#if IS_ENABLED(CONFIG_AGP_INTEL)
static int intel_gtt_map_memory(struct page **pages,
                                unsigned int num_entries,
                                struct sg_table *st)
{
        struct scatterlist *sg;
        int i;

        DBG("try mapping %lu pages\n", (unsigned long)num_entries);

        if (sg_alloc_table(st, num_entries, GFP_KERNEL))
                goto err;

        for_each_sg(st->sgl, sg, num_entries, i)
                sg_set_page(sg, pages[i], PAGE_SIZE, 0);

        if (!pci_map_sg(intel_private.pcidev,
                        st->sgl, st->nents, PCI_DMA_BIDIRECTIONAL))
                goto err;

        return 0;

err:
        sg_free_table(st);
        return -ENOMEM;
}

static void intel_gtt_unmap_memory(struct scatterlist *sg_list, int num_sg)
{
        struct sg_table st;
        DBG("try unmapping %lu pages\n", (unsigned long)mem->page_count);

        pci_unmap_sg(intel_private.pcidev, sg_list,
                     num_sg, PCI_DMA_BIDIRECTIONAL);

        st.sgl = sg_list;
        st.orig_nents = st.nents = num_sg;

        sg_free_table(&st);
}

static void intel_fake_agp_enable(struct agp_bridge_data *bridge, u32 mode)
{
        return;
}

/* Exists to support ARGB cursors */
static struct page *i8xx_alloc_pages(void)
{
        struct page *page;

        page = alloc_pages(GFP_KERNEL | GFP_DMA32, 2);
        if (page == NULL)
                return NULL;

        if (set_pages_uc(page, 4) < 0) {
                set_pages_wb(page, 4);
                __free_pages(page, 2);
                return NULL;
        }
        get_page(page);
        atomic_inc(&agp_bridge->current_memory_agp);
        return page;
}

static void i8xx_destroy_pages(struct page *page)
{
        if (page == NULL)
                return;

        set_pages_wb(page, 4);
        put_page(page);
        __free_pages(page, 2);
        atomic_dec(&agp_bridge->current_memory_agp);
}
#endif

#define I810_GTT_ORDER 4
static int i810_setup(void)
{
        u32 reg_addr;
        char *gtt_table;

        /* i81x does not preallocate the gtt. It's always 64kb in size. */
        gtt_table = alloc_gatt_pages(I810_GTT_ORDER);
        if (gtt_table == NULL)
                return -ENOMEM;
        intel_private.i81x_gtt_table = gtt_table;

        pci_read_config_dword(intel_private.pcidev, I810_MMADDR, &reg_addr);
        reg_addr &= 0xfff80000;

        intel_private.registers = ioremap(reg_addr, KB(64));
        if (!intel_private.registers)
                return -ENOMEM;

        writel(virt_to_phys(gtt_table) | I810_PGETBL_ENABLED,
               intel_private.registers+I810_PGETBL_CTL);

        intel_private.gtt_bus_addr = reg_addr + I810_PTE_BASE;

        if ((readl(intel_private.registers+I810_DRAM_CTL)
                & I810_DRAM_ROW_0) == I810_DRAM_ROW_0_SDRAM) {
                dev_info(&intel_private.pcidev->dev,
                         "detected 4MB dedicated video ram\n");
                intel_private.num_dcache_entries = 1024;
        }

        return 0;
}

static void i810_cleanup(void)
{
        writel(0, intel_private.registers+I810_PGETBL_CTL);
        free_gatt_pages(intel_private.i81x_gtt_table, I810_GTT_ORDER);
}

#if IS_ENABLED(CONFIG_AGP_INTEL)
static int i810_insert_dcache_entries(struct agp_memory *mem, off_t pg_start,
                                      int type)
{
        int i;

        if ((pg_start + mem->page_count)
                        > intel_private.num_dcache_entries)
                return -EINVAL;

        if (!mem->is_flushed)
                global_cache_flush();

        for (i = pg_start; i < (pg_start + mem->page_count); i++) {
                dma_addr_t addr = i << PAGE_SHIFT;
                intel_private.driver->write_entry(addr,
                                                  i, type);
        }
        readl(intel_private.gtt+i-1);

        return 0;
}

/*
 * The i810/i830 requires a physical address to program its mouse
 * pointer into hardware.
 * However the Xserver still writes to it through the agp aperture.
 */
static struct agp_memory *alloc_agpphysmem_i8xx(size_t pg_count, int type)
{
        struct agp_memory *new;
        struct page *page;

        switch (pg_count) {
        case 1: page = agp_bridge->driver->agp_alloc_page(agp_bridge);
                break;
        case 4:
                /* kludge to get 4 physical pages for ARGB cursor */
                page = i8xx_alloc_pages();
                break;
        default:
                return NULL;
        }

        if (page == NULL)
                return NULL;

        new = agp_create_memory(pg_count);
        if (new == NULL)
                return NULL;

        new->pages[0] = page;
        if (pg_count == 4) {
                /* kludge to get 4 physical pages for ARGB cursor */
                new->pages[1] = new->pages[0] + 1;
                new->pages[2] = new->pages[1] + 1;
                new->pages[3] = new->pages[2] + 1;
        }
        new->page_count = pg_count;
        new->num_scratch_pages = pg_count;
        new->type = AGP_PHYS_MEMORY;
        new->physical = page_to_phys(new->pages[0]);
        return new;
}

static void intel_i810_free_by_type(struct agp_memory *curr)
{
        agp_free_key(curr->key);
        if (curr->type == AGP_PHYS_MEMORY) {
                if (curr->page_count == 4)
                        i8xx_destroy_pages(curr->pages[0]);
                else {
                        agp_bridge->driver->agp_destroy_page(curr->pages[0],
                                                             AGP_PAGE_DESTROY_UNMAP);
                        agp_bridge->driver->agp_destroy_page(curr->pages[0],
                                                             AGP_PAGE_DESTROY_FREE);
                }
                agp_free_page_array(curr);
        }
        kfree(curr);
}
#endif

static int intel_gtt_setup_scratch_page(void)
{
        struct page *page;
        dma_addr_t dma_addr;

        page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
        if (page == NULL)
                return -ENOMEM;
        get_page(page);
        set_pages_uc(page, 1);

        if (intel_private.needs_dmar) {
                dma_addr = pci_map_page(intel_private.pcidev, page, 0,
                                    PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
                if (pci_dma_mapping_error(intel_private.pcidev, dma_addr))
                        return -EINVAL;

                intel_private.scratch_page_dma = dma_addr;
        } else
                intel_private.scratch_page_dma = page_to_phys(page);

        intel_private.scratch_page = page;

        return 0;
}

static void i810_write_entry(dma_addr_t addr, unsigned int entry,
                             unsigned int flags)
{
        u32 pte_flags = I810_PTE_VALID;

        switch (flags) {
        case AGP_DCACHE_MEMORY:
                pte_flags |= I810_PTE_LOCAL;
                break;
        case AGP_USER_CACHED_MEMORY:
                pte_flags |= I830_PTE_SYSTEM_CACHED;
                break;
        }

        writel(addr | pte_flags, intel_private.gtt + entry);
}

static const struct aper_size_info_fixed intel_fake_agp_sizes[] = {
        {32, 8192, 3},
        {64, 16384, 4},
        {128, 32768, 5},
        {256, 65536, 6},
        {512, 131072, 7},
};

static unsigned int intel_gtt_stolen_size(void)
{
        u16 gmch_ctrl;
        u8 rdct;
        int local = 0;
        static const int ddt[4] = { 0, 16, 32, 64 };
        unsigned int stolen_size = 0;

        if (INTEL_GTT_GEN == 1)
                return 0; /* no stolen mem on i81x */

        pci_read_config_word(intel_private.bridge_dev,
                             I830_GMCH_CTRL, &gmch_ctrl);

        if (intel_private.bridge_dev->device == PCI_DEVICE_ID_INTEL_82830_HB ||
            intel_private.bridge_dev->device == PCI_DEVICE_ID_INTEL_82845G_HB) {
                switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
                case I830_GMCH_GMS_STOLEN_512:
                        stolen_size = KB(512);
                        break;
                case I830_GMCH_GMS_STOLEN_1024:
                        stolen_size = MB(1);
                        break;
                case I830_GMCH_GMS_STOLEN_8192:
                        stolen_size = MB(8);
                        break;
                case I830_GMCH_GMS_LOCAL:
                        rdct = readb(intel_private.registers+I830_RDRAM_CHANNEL_TYPE);
                        stolen_size = (I830_RDRAM_ND(rdct) + 1) *
                                        MB(ddt[I830_RDRAM_DDT(rdct)]);
                        local = 1;
                        break;
                default:
                        stolen_size = 0;
                        break;
                }
        } else {
                switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
                case I855_GMCH_GMS_STOLEN_1M:
                        stolen_size = MB(1);
                        break;
                case I855_GMCH_GMS_STOLEN_4M:
                        stolen_size = MB(4);
                        break;
                case I855_GMCH_GMS_STOLEN_8M:
                        stolen_size = MB(8);
                        break;
                case I855_GMCH_GMS_STOLEN_16M:
                        stolen_size = MB(16);
                        break;
                case I855_GMCH_GMS_STOLEN_32M:
                        stolen_size = MB(32);
                        break;
                case I915_GMCH_GMS_STOLEN_48M:
                        stolen_size = MB(48);
                        break;
                case I915_GMCH_GMS_STOLEN_64M:
                        stolen_size = MB(64);
                        break;
                case G33_GMCH_GMS_STOLEN_128M:
                        stolen_size = MB(128);
                        break;
                case G33_GMCH_GMS_STOLEN_256M:
                        stolen_size = MB(256);
                        break;
                case INTEL_GMCH_GMS_STOLEN_96M:
                        stolen_size = MB(96);
                        break;
                case INTEL_GMCH_GMS_STOLEN_160M:
                        stolen_size = MB(160);
                        break;
                case INTEL_GMCH_GMS_STOLEN_224M:
                        stolen_size = MB(224);
                        break;
                case INTEL_GMCH_GMS_STOLEN_352M:
                        stolen_size = MB(352);
                        break;
                default:
                        stolen_size = 0;
                        break;
                }
        }

        if (stolen_size > 0) {
                dev_info(&intel_private.bridge_dev->dev, "detected %dK %s memory\n",
                       stolen_size / KB(1), local ? "local" : "stolen");
        } else {
                dev_info(&intel_private.bridge_dev->dev,
                       "no pre-allocated video memory detected\n");
                stolen_size = 0;
        }

        return stolen_size;
}

static void i965_adjust_pgetbl_size(unsigned int size_flag)
{
        u32 pgetbl_ctl, pgetbl_ctl2;

        /* ensure that ppgtt is disabled */
        pgetbl_ctl2 = readl(intel_private.registers+I965_PGETBL_CTL2);
        pgetbl_ctl2 &= ~I810_PGETBL_ENABLED;
        writel(pgetbl_ctl2, intel_private.registers+I965_PGETBL_CTL2);

        /* write the new ggtt size */
        pgetbl_ctl = readl(intel_private.registers+I810_PGETBL_CTL);
        pgetbl_ctl &= ~I965_PGETBL_SIZE_MASK;
        pgetbl_ctl |= size_flag;
        writel(pgetbl_ctl, intel_private.registers+I810_PGETBL_CTL);
}

static unsigned int i965_gtt_total_entries(void)
{
        int size;
        u32 pgetbl_ctl;
        u16 gmch_ctl;

        pci_read_config_word(intel_private.bridge_dev,
                             I830_GMCH_CTRL, &gmch_ctl);

        if (INTEL_GTT_GEN == 5) {
                switch (gmch_ctl & G4x_GMCH_SIZE_MASK) {
                case G4x_GMCH_SIZE_1M:
                case G4x_GMCH_SIZE_VT_1M:
                        i965_adjust_pgetbl_size(I965_PGETBL_SIZE_1MB);
                        break;
                case G4x_GMCH_SIZE_VT_1_5M:
                        i965_adjust_pgetbl_size(I965_PGETBL_SIZE_1_5MB);
                        break;
                case G4x_GMCH_SIZE_2M:
                case G4x_GMCH_SIZE_VT_2M:
                        i965_adjust_pgetbl_size(I965_PGETBL_SIZE_2MB);
                        break;
                }
        }

        pgetbl_ctl = readl(intel_private.registers+I810_PGETBL_CTL);

        switch (pgetbl_ctl & I965_PGETBL_SIZE_MASK) {
        case I965_PGETBL_SIZE_128KB:
                size = KB(128);
                break;
        case I965_PGETBL_SIZE_256KB:
                size = KB(256);
                break;
        case I965_PGETBL_SIZE_512KB:
                size = KB(512);
                break;
        /* GTT pagetable sizes bigger than 512KB are not possible on G33! */
        case I965_PGETBL_SIZE_1MB:
                size = KB(1024);
                break;
        case I965_PGETBL_SIZE_2MB:
                size = KB(2048);
                break;
        case I965_PGETBL_SIZE_1_5MB:
                size = KB(1024 + 512);
                break;
        default:
                dev_info(&intel_private.pcidev->dev,
                         "unknown page table size, assuming 512KB\n");
                size = KB(512);
        }

        return size/4;
}

static unsigned int intel_gtt_total_entries(void)
{
        if (IS_G33 || INTEL_GTT_GEN == 4 || INTEL_GTT_GEN == 5)
                return i965_gtt_total_entries();
        else {
                /* On previous hardware, the GTT size was just what was
                 * required to map the aperture.
                 */
                return intel_private.gtt_mappable_entries;
        }
}

static unsigned int intel_gtt_mappable_entries(void)
{
        unsigned int aperture_size;

        if (INTEL_GTT_GEN == 1) {
                u32 smram_miscc;

                pci_read_config_dword(intel_private.bridge_dev,
                                      I810_SMRAM_MISCC, &smram_miscc);

                if ((smram_miscc & I810_GFX_MEM_WIN_SIZE)
                                == I810_GFX_MEM_WIN_32M)
                        aperture_size = MB(32);
                else
                        aperture_size = MB(64);
        } else if (INTEL_GTT_GEN == 2) {
                u16 gmch_ctrl;

                pci_read_config_word(intel_private.bridge_dev,
                                     I830_GMCH_CTRL, &gmch_ctrl);

                if ((gmch_ctrl & I830_GMCH_MEM_MASK) == I830_GMCH_MEM_64M)
                        aperture_size = MB(64);
                else
                        aperture_size = MB(128);
        } else {
                /* 9xx supports large sizes, just look at the length */
                aperture_size = pci_resource_len(intel_private.pcidev, 2);
        }

        return aperture_size >> PAGE_SHIFT;
}

static void intel_gtt_teardown_scratch_page(void)
{
        set_pages_wb(intel_private.scratch_page, 1);
        pci_unmap_page(intel_private.pcidev, intel_private.scratch_page_dma,
                       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
        put_page(intel_private.scratch_page);
        __free_page(intel_private.scratch_page);
}

static void intel_gtt_cleanup(void)
{
        intel_private.driver->cleanup();

        iounmap(intel_private.gtt);
        iounmap(intel_private.registers);

        intel_gtt_teardown_scratch_page();
}

/* Certain Gen5 chipsets require require idling the GPU before
 * unmapping anything from the GTT when VT-d is enabled.
 */
static inline int needs_ilk_vtd_wa(void)
{
#ifdef CONFIG_INTEL_IOMMU
        const unsigned short gpu_devid = intel_private.pcidev->device;

        /* Query intel_iommu to see if we need the workaround. Presumably that
         * was loaded first.
         */
        if ((gpu_devid == PCI_DEVICE_ID_INTEL_IRONLAKE_M_HB ||
             gpu_devid == PCI_DEVICE_ID_INTEL_IRONLAKE_M_IG) &&
             intel_iommu_gfx_mapped)
                return 1;
#endif
        return 0;
}

static bool intel_gtt_can_wc(void)
{
        if (INTEL_GTT_GEN <= 2)
                return false;

        if (INTEL_GTT_GEN >= 6)
                return false;

        /* Reports of major corruption with ILK vt'd enabled */
        if (needs_ilk_vtd_wa())
                return false;

        return true;
}

static int intel_gtt_init(void)
{
        u32 gma_addr;
        u32 gtt_map_size;
        int ret;

        ret = intel_private.driver->setup();
        if (ret != 0)
                return ret;

        intel_private.gtt_mappable_entries = intel_gtt_mappable_entries();
        intel_private.gtt_total_entries = intel_gtt_total_entries();

        /* save the PGETBL reg for resume */
        intel_private.PGETBL_save =
                readl(intel_private.registers+I810_PGETBL_CTL)
                        & ~I810_PGETBL_ENABLED;
        /* we only ever restore the register when enabling the PGTBL... */
        if (HAS_PGTBL_EN)
                intel_private.PGETBL_save |= I810_PGETBL_ENABLED;

        dev_info(&intel_private.bridge_dev->dev,
                        "detected gtt size: %dK total, %dK mappable\n",
                        intel_private.gtt_total_entries * 4,
                        intel_private.gtt_mappable_entries * 4);

        gtt_map_size = intel_private.gtt_total_entries * 4;

        intel_private.gtt = NULL;
        if (intel_gtt_can_wc())
                intel_private.gtt = ioremap_wc(intel_private.gtt_bus_addr,
                                               gtt_map_size);
        if (intel_private.gtt == NULL)
                intel_private.gtt = ioremap(intel_private.gtt_bus_addr,
                                            gtt_map_size);
        if (intel_private.gtt == NULL) {
                intel_private.driver->cleanup();
                iounmap(intel_private.registers);
                return -ENOMEM;
        }

#if IS_ENABLED(CONFIG_AGP_INTEL)
        global_cache_flush();   /* FIXME: ? */
#endif

        intel_private.stolen_size = intel_gtt_stolen_size();

        intel_private.needs_dmar = USE_PCI_DMA_API && INTEL_GTT_GEN > 2;

        ret = intel_gtt_setup_scratch_page();
        if (ret != 0) {
                intel_gtt_cleanup();
                return ret;
        }

        if (INTEL_GTT_GEN <= 2)
                pci_read_config_dword(intel_private.pcidev, I810_GMADDR,
                                      &gma_addr);
        else
                pci_read_config_dword(intel_private.pcidev, I915_GMADDR,
                                      &gma_addr);

        intel_private.gma_bus_addr = (gma_addr & PCI_BASE_ADDRESS_MEM_MASK);

        return 0;
}

#if IS_ENABLED(CONFIG_AGP_INTEL)
static int intel_fake_agp_fetch_size(void)
{
        int num_sizes = ARRAY_SIZE(intel_fake_agp_sizes);
        unsigned int aper_size;
        int i;

        aper_size = (intel_private.gtt_mappable_entries << PAGE_SHIFT) / MB(1);

        for (i = 0; i < num_sizes; i++) {
                if (aper_size == intel_fake_agp_sizes[i].size) {
                        agp_bridge->current_size =
                                (void *) (intel_fake_agp_sizes + i);
                        return aper_size;
                }
        }

        return 0;
}
#endif

static void i830_cleanup(void)
{
}

/* The chipset_flush interface needs to get data that has already been
 * flushed out of the CPU all the way out to main memory, because the GPU
 * doesn't snoop those buffers.
 *
 * The 8xx series doesn't have the same lovely interface for flushing the
 * chipset write buffers that the later chips do. According to the 865
 * specs, it's 64 octwords, or 1KB.  So, to get those previous things in
 * that buffer out, we just fill 1KB and clflush it out, on the assumption
 * that it'll push whatever was in there out.  It appears to work.
 */
static void i830_chipset_flush(void)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(1000);

        /* Forcibly evict everything from the CPU write buffers.
         * clflush appears to be insufficient.
         */
        wbinvd_on_all_cpus();

        /* Now we've only seen documents for this magic bit on 855GM,
         * we hope it exists for the other gen2 chipsets...
         *
         * Also works as advertised on my 845G.
         */
        writel(readl(intel_private.registers+I830_HIC) | (1<<31),
               intel_private.registers+I830_HIC);

        while (readl(intel_private.registers+I830_HIC) & (1<<31)) {
                if (time_after(jiffies, timeout))
                        break;

                udelay(50);
        }
}

static void i830_write_entry(dma_addr_t addr, unsigned int entry,
                             unsigned int flags)
{
        u32 pte_flags = I810_PTE_VALID;

        if (flags ==  AGP_USER_CACHED_MEMORY)
                pte_flags |= I830_PTE_SYSTEM_CACHED;

        writel(addr | pte_flags, intel_private.gtt + entry);
}

bool intel_enable_gtt(void)
{
        u8 __iomem *reg;

        if (INTEL_GTT_GEN == 2) {
                u16 gmch_ctrl;

                pci_read_config_word(intel_private.bridge_dev,
                                     I830_GMCH_CTRL, &gmch_ctrl);
                gmch_ctrl |= I830_GMCH_ENABLED;
                pci_write_config_word(intel_private.bridge_dev,
                                      I830_GMCH_CTRL, gmch_ctrl);

                pci_read_config_word(intel_private.bridge_dev,
                                     I830_GMCH_CTRL, &gmch_ctrl);
                if ((gmch_ctrl & I830_GMCH_ENABLED) == 0) {
                        dev_err(&intel_private.pcidev->dev,
                                "failed to enable the GTT: GMCH_CTRL=%x\n",
                                gmch_ctrl);
                        return false;
                }
        }

        /* On the resume path we may be adjusting the PGTBL value, so
         * be paranoid and flush all chipset write buffers...
         */
        if (INTEL_GTT_GEN >= 3)
                writel(0, intel_private.registers+GFX_FLSH_CNTL);

        reg = intel_private.registers+I810_PGETBL_CTL;
        writel(intel_private.PGETBL_save, reg);
        if (HAS_PGTBL_EN && (readl(reg) & I810_PGETBL_ENABLED) == 0) {
                dev_err(&intel_private.pcidev->dev,
                        "failed to enable the GTT: PGETBL=%x [expected %x]\n",
                        readl(reg), intel_private.PGETBL_save);
                return false;
        }

        if (INTEL_GTT_GEN >= 3)
                writel(0, intel_private.registers+GFX_FLSH_CNTL);

        return true;
}
EXPORT_SYMBOL(intel_enable_gtt);

static int i830_setup(void)
{
        u32 reg_addr;

        pci_read_config_dword(intel_private.pcidev, I810_MMADDR, &reg_addr);
        reg_addr &= 0xfff80000;

        intel_private.registers = ioremap(reg_addr, KB(64));
        if (!intel_private.registers)
                return -ENOMEM;

        intel_private.gtt_bus_addr = reg_addr + I810_PTE_BASE;

        return 0;
}

#if IS_ENABLED(CONFIG_AGP_INTEL)
static int intel_fake_agp_create_gatt_table(struct agp_bridge_data *bridge)
{
        agp_bridge->gatt_table_real = NULL;
        agp_bridge->gatt_table = NULL;
        agp_bridge->gatt_bus_addr = 0;

        return 0;
}

static int intel_fake_agp_free_gatt_table(struct agp_bridge_data *bridge)
{
        return 0;
}

static int intel_fake_agp_configure(void)
{
        if (!intel_enable_gtt())
            return -EIO;

        intel_private.clear_fake_agp = true;
        agp_bridge->gart_bus_addr = intel_private.gma_bus_addr;

        return 0;
}
#endif

static bool i830_check_flags(unsigned int flags)
{
        switch (flags) {
        case 0:
        case AGP_PHYS_MEMORY:
        case AGP_USER_CACHED_MEMORY:
        case AGP_USER_MEMORY:
                return true;
        }

        return false;
}

void intel_gtt_insert_sg_entries(struct sg_table *st,
                                 unsigned int pg_start,
                                 unsigned int flags)
{
        struct scatterlist *sg;
        unsigned int len, m;
        int i, j;

        j = pg_start;

        /* sg may merge pages, but we have to separate
         * per-page addr for GTT */
        for_each_sg(st->sgl, sg, st->nents, i) {
                len = sg_dma_len(sg) >> PAGE_SHIFT;
                for (m = 0; m < len; m++) {
                        dma_addr_t addr = sg_dma_address(sg) + (m << PAGE_SHIFT);
                        intel_private.driver->write_entry(addr, j, flags);
                        j++;
                }
        }
        readl(intel_private.gtt+j-1);
}
EXPORT_SYMBOL(intel_gtt_insert_sg_entries);

#if IS_ENABLED(CONFIG_AGP_INTEL)
static void intel_gtt_insert_pages(unsigned int first_entry,
                                   unsigned int num_entries,
                                   struct page **pages,
                                   unsigned int flags)
{
        int i, j;

        for (i = 0, j = first_entry; i < num_entries; i++, j++) {
                dma_addr_t addr = page_to_phys(pages[i]);
                intel_private.driver->write_entry(addr,
                                                  j, flags);
        }
        readl(intel_private.gtt+j-1);
}

static int intel_fake_agp_insert_entries(struct agp_memory *mem,
                                         off_t pg_start, int type)
{
        int ret = -EINVAL;

        if (intel_private.clear_fake_agp) {
                int start = intel_private.stolen_size / PAGE_SIZE;
                int end = intel_private.gtt_mappable_entries;
                intel_gtt_clear_range(start, end - start);
                intel_private.clear_fake_agp = false;
        }

        if (INTEL_GTT_GEN == 1 && type == AGP_DCACHE_MEMORY)
                return i810_insert_dcache_entries(mem, pg_start, type);

        if (mem->page_count == 0)
                goto out;

        if (pg_start + mem->page_count > intel_private.gtt_total_entries)
                goto out_err;

        if (type != mem->type)
                goto out_err;

        if (!intel_private.driver->check_flags(type))
                goto out_err;

        if (!mem->is_flushed)
                global_cache_flush();

        if (intel_private.needs_dmar) {
                struct sg_table st;

                ret = intel_gtt_map_memory(mem->pages, mem->page_count, &st);
                if (ret != 0)
                        return ret;

                intel_gtt_insert_sg_entries(&st, pg_start, type);
                mem->sg_list = st.sgl;
                mem->num_sg = st.nents;
        } else
                intel_gtt_insert_pages(pg_start, mem->page_count, mem->pages,
                                       type);

out:
        ret = 0;
out_err:
        mem->is_flushed = true;
        return ret;
}
#endif

void intel_gtt_clear_range(unsigned int first_entry, unsigned int num_entries)
{
        unsigned int i;

        for (i = first_entry; i < (first_entry + num_entries); i++) {
                intel_private.driver->write_entry(intel_private.scratch_page_dma,
                                                  i, 0);
        }
        readl(intel_private.gtt+i-1);
}
EXPORT_SYMBOL(intel_gtt_clear_range);

#if IS_ENABLED(CONFIG_AGP_INTEL)
static int intel_fake_agp_remove_entries(struct agp_memory *mem,
                                         off_t pg_start, int type)
{
        if (mem->page_count == 0)
                return 0;

        intel_gtt_clear_range(pg_start, mem->page_count);

        if (intel_private.needs_dmar) {
                intel_gtt_unmap_memory(mem->sg_list, mem->num_sg);
                mem->sg_list = NULL;
                mem->num_sg = 0;
        }

        return 0;
}

static struct agp_memory *intel_fake_agp_alloc_by_type(size_t pg_count,
                                                       int type)
{
        struct agp_memory *new;

        if (type == AGP_DCACHE_MEMORY && INTEL_GTT_GEN == 1) {
                if (pg_count != intel_private.num_dcache_entries)
                        return NULL;

                new = agp_create_memory(1);
                if (new == NULL)
                        return NULL;

                new->type = AGP_DCACHE_MEMORY;
                new->page_count = pg_count;
                new->num_scratch_pages = 0;
                agp_free_page_array(new);
                return new;
        }
        if (type == AGP_PHYS_MEMORY)
                return alloc_agpphysmem_i8xx(pg_count, type);
        /* always return NULL for other allocation types for now */
        return NULL;
}
#endif

static int intel_alloc_chipset_flush_resource(void)
{
        int ret;
        ret = pci_bus_alloc_resource(intel_private.bridge_dev->bus, &intel_private.ifp_resource, PAGE_SIZE,
                                     PAGE_SIZE, PCIBIOS_MIN_MEM, 0,
                                     pcibios_align_resource, intel_private.bridge_dev);

        return ret;
}

static void intel_i915_setup_chipset_flush(void)
{
        int ret;
        u32 temp;

        pci_read_config_dword(intel_private.bridge_dev, I915_IFPADDR, &temp);
        if (!(temp & 0x1)) {
                intel_alloc_chipset_flush_resource();
                intel_private.resource_valid = 1;
                pci_write_config_dword(intel_private.bridge_dev, I915_IFPADDR, (intel_private.ifp_resource.start & 0xffffffff) | 0x1);
        } else {
                temp &= ~1;

                intel_private.resource_valid = 1;
                intel_private.ifp_resource.start = temp;
                intel_private.ifp_resource.end = temp + PAGE_SIZE;
                ret = request_resource(&iomem_resource, &intel_private.ifp_resource);
                /* some BIOSes reserve this area in a pnp some don't */
                if (ret)
                        intel_private.resource_valid = 0;
        }
}

static void intel_i965_g33_setup_chipset_flush(void)
{
        u32 temp_hi, temp_lo;
        int ret;

        pci_read_config_dword(intel_private.bridge_dev, I965_IFPADDR + 4, &temp_hi);
        pci_read_config_dword(intel_private.bridge_dev, I965_IFPADDR, &temp_lo);

        if (!(temp_lo & 0x1)) {

                intel_alloc_chipset_flush_resource();

                intel_private.resource_valid = 1;
                pci_write_config_dword(intel_private.bridge_dev, I965_IFPADDR + 4,
                        upper_32_bits(intel_private.ifp_resource.start));
                pci_write_config_dword(intel_private.bridge_dev, I965_IFPADDR, (intel_private.ifp_resource.start & 0xffffffff) | 0x1);
        } else {
                u64 l64;

                temp_lo &= ~0x1;
                l64 = ((u64)temp_hi << 32) | temp_lo;

                intel_private.resource_valid = 1;
                intel_private.ifp_resource.start = l64;
                intel_private.ifp_resource.end = l64 + PAGE_SIZE;
                ret = request_resource(&iomem_resource, &intel_private.ifp_resource);
                /* some BIOSes reserve this area in a pnp some don't */
                if (ret)
                        intel_private.resource_valid = 0;
        }
}

static void intel_i9xx_setup_flush(void)
{
        /* return if already configured */
        if (intel_private.ifp_resource.start)
                return;

        if (INTEL_GTT_GEN == 6)
                return;

        /* setup a resource for this object */
        intel_private.ifp_resource.name = "Intel Flush Page";
        intel_private.ifp_resource.flags = IORESOURCE_MEM;

        /* Setup chipset flush for 915 */
        if (IS_G33 || INTEL_GTT_GEN >= 4) {
                intel_i965_g33_setup_chipset_flush();
        } else {
                intel_i915_setup_chipset_flush();
        }

        if (intel_private.ifp_resource.start)
                intel_private.i9xx_flush_page = ioremap_nocache(intel_private.ifp_resource.start, PAGE_SIZE);
        if (!intel_private.i9xx_flush_page)
                dev_err(&intel_private.pcidev->dev,
                        "can't ioremap flush page - no chipset flushing\n");
}

static void i9xx_cleanup(void)
{
        if (intel_private.i9xx_flush_page)
                iounmap(intel_private.i9xx_flush_page);
        if (intel_private.resource_valid)
                release_resource(&intel_private.ifp_resource);
        intel_private.ifp_resource.start = 0;
        intel_private.resource_valid = 0;
}

static void i9xx_chipset_flush(void)
{
        if (intel_private.i9xx_flush_page)
                writel(1, intel_private.i9xx_flush_page);
}

static void i965_write_entry(dma_addr_t addr,
                             unsigned int entry,
                             unsigned int flags)
{
        u32 pte_flags;

        pte_flags = I810_PTE_VALID;
        if (flags == AGP_USER_CACHED_MEMORY)
                pte_flags |= I830_PTE_SYSTEM_CACHED;

        /* Shift high bits down */
        addr |= (addr >> 28) & 0xf0;
        writel(addr | pte_flags, intel_private.gtt + entry);
}

static int i9xx_setup(void)
{
        u32 reg_addr, gtt_addr;
        int size = KB(512);

        pci_read_config_dword(intel_private.pcidev, I915_MMADDR, &reg_addr);

        reg_addr &= 0xfff80000;

        intel_private.registers = ioremap(reg_addr, size);
        if (!intel_private.registers)
                return -ENOMEM;

        switch (INTEL_GTT_GEN) {
        case 3:
                pci_read_config_dword(intel_private.pcidev,
                                      I915_PTEADDR, &gtt_addr);
                intel_private.gtt_bus_addr = gtt_addr;
                break;
        case 5:
                intel_private.gtt_bus_addr = reg_addr + MB(2);
                break;
        default:
                intel_private.gtt_bus_addr = reg_addr + KB(512);
                break;
        }

        intel_i9xx_setup_flush();

        return 0;
}

#if IS_ENABLED(CONFIG_AGP_INTEL)
static const struct agp_bridge_driver intel_fake_agp_driver = {
        .owner                  = THIS_MODULE,
        .size_type              = FIXED_APER_SIZE,
        .aperture_sizes         = intel_fake_agp_sizes,
        .num_aperture_sizes     = ARRAY_SIZE(intel_fake_agp_sizes),
        .configure              = intel_fake_agp_configure,
        .fetch_size             = intel_fake_agp_fetch_size,
        .cleanup                = intel_gtt_cleanup,
        .agp_enable             = intel_fake_agp_enable,
        .cache_flush            = global_cache_flush,
        .create_gatt_table      = intel_fake_agp_create_gatt_table,
        .free_gatt_table        = intel_fake_agp_free_gatt_table,
        .insert_memory          = intel_fake_agp_insert_entries,
        .remove_memory          = intel_fake_agp_remove_entries,
        .alloc_by_type          = intel_fake_agp_alloc_by_type,
        .free_by_type           = intel_i810_free_by_type,
        .agp_alloc_page         = agp_generic_alloc_page,
        .agp_alloc_pages        = agp_generic_alloc_pages,
        .agp_destroy_page       = agp_generic_destroy_page,
        .agp_destroy_pages      = agp_generic_destroy_pages,
};
#endif

static const struct intel_gtt_driver i81x_gtt_driver = {
        .gen = 1,
        .has_pgtbl_enable = 1,
        .dma_mask_size = 32,
        .setup = i810_setup,
        .cleanup = i810_cleanup,
        .check_flags = i830_check_flags,
        .write_entry = i810_write_entry,
};
static const struct intel_gtt_driver i8xx_gtt_driver = {
        .gen = 2,
        .has_pgtbl_enable = 1,
        .setup = i830_setup,
        .cleanup = i830_cleanup,
        .write_entry = i830_write_entry,
        .dma_mask_size = 32,
        .check_flags = i830_check_flags,
        .chipset_flush = i830_chipset_flush,
};
static const struct intel_gtt_driver i915_gtt_driver = {
        .gen = 3,
        .has_pgtbl_enable = 1,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        /* i945 is the last gpu to need phys mem (for overlay and cursors). */
        .write_entry = i830_write_entry,
        .dma_mask_size = 32,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};
static const struct intel_gtt_driver g33_gtt_driver = {
        .gen = 3,
        .is_g33 = 1,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        .write_entry = i965_write_entry,
        .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};
static const struct intel_gtt_driver pineview_gtt_driver = {
        .gen = 3,
        .is_pineview = 1, .is_g33 = 1,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        .write_entry = i965_write_entry,
        .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};
static const struct intel_gtt_driver i965_gtt_driver = {
        .gen = 4,
        .has_pgtbl_enable = 1,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        .write_entry = i965_write_entry,
        .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};
static const struct intel_gtt_driver g4x_gtt_driver = {
        .gen = 5,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        .write_entry = i965_write_entry,
        .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};
static const struct intel_gtt_driver ironlake_gtt_driver = {
        .gen = 5,
        .is_ironlake = 1,
        .setup = i9xx_setup,
        .cleanup = i9xx_cleanup,
        .write_entry = i965_write_entry,
        .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
};

/* Table to describe Intel GMCH and AGP/PCIE GART drivers.  At least one of
 * driver and gmch_driver must be non-null, and find_gmch will determine
 * which one should be used if a gmch_chip_id is present.
 */
static const struct intel_gtt_driver_description {
        unsigned int gmch_chip_id;
        char *name;
        const struct intel_gtt_driver *gtt_driver;
} intel_gtt_chipsets[] = {
        { PCI_DEVICE_ID_INTEL_82810_IG1, "i810",
                &i81x_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82810_IG3, "i810",
                &i81x_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82810E_IG, "i810",
                &i81x_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82815_CGC, "i815",
                &i81x_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82830_CGC, "830M",
                &i8xx_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82845G_IG, "845G",
                &i8xx_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82854_IG, "854",
                &i8xx_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82855GM_IG, "855GM",
                &i8xx_gtt_driver},
        { PCI_DEVICE_ID_INTEL_82865_IG, "865",
                &i8xx_gtt_driver},
        { PCI_DEVICE_ID_INTEL_E7221_IG, "E7221 (i915)",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82915G_IG, "915G",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82915GM_IG, "915GM",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82945G_IG, "945G",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82945GM_IG, "945GM",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82945GME_IG, "945GME",
                &i915_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82946GZ_IG, "946GZ",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82G35_IG, "G35",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82965Q_IG, "965Q",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82965G_IG, "965G",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82965GM_IG, "965GM",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_82965GME_IG, "965GME/GLE",
                &i965_gtt_driver },
        { PCI_DEVICE_ID_INTEL_G33_IG, "G33",
                &g33_gtt_driver },
        { PCI_DEVICE_ID_INTEL_Q35_IG, "Q35",
                &g33_gtt_driver },
        { PCI_DEVICE_ID_INTEL_Q33_IG, "Q33",
                &g33_gtt_driver },
        { PCI_DEVICE_ID_INTEL_PINEVIEW_M_IG, "GMA3150",
                &pineview_gtt_driver },
        { PCI_DEVICE_ID_INTEL_PINEVIEW_IG, "GMA3150",
                &pineview_gtt_driver },
        { PCI_DEVICE_ID_INTEL_GM45_IG, "GM45",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_EAGLELAKE_IG, "Eaglelake",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_Q45_IG, "Q45/Q43",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_G45_IG, "G45/G43",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_B43_IG, "B43",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_B43_1_IG, "B43",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_G41_IG, "G41",
                &g4x_gtt_driver },
        { PCI_DEVICE_ID_INTEL_IRONLAKE_D_IG,
            "HD Graphics", &ironlake_gtt_driver },
        { PCI_DEVICE_ID_INTEL_IRONLAKE_M_IG,
            "HD Graphics", &ironlake_gtt_driver },
        { 0, NULL, NULL }
};

static int find_gmch(u16 device)
{
        struct pci_dev *gmch_device;

        gmch_device = pci_get_device(PCI_VENDOR_ID_INTEL, device, NULL);
        if (gmch_device && PCI_FUNC(gmch_device->devfn) != 0) {
                gmch_device = pci_get_device(PCI_VENDOR_ID_INTEL,
                                             device, gmch_device);
        }

        if (!gmch_device)
                return 0;

        intel_private.pcidev = gmch_device;
        return 1;
}

int intel_gmch_probe(struct pci_dev *bridge_pdev, struct pci_dev *gpu_pdev,
                     struct agp_bridge_data *bridge)
{
        int i, mask;

        /*
         * Can be called from the fake agp driver but also directly from
         * drm/i915.ko. Hence we need to check whether everything is set up
         * already.
         */
        if (intel_private.driver) {
                intel_private.refcount++;
                return 1;
        }

        for (i = 0; intel_gtt_chipsets[i].name != NULL; i++) {
                if (gpu_pdev) {
                        if (gpu_pdev->device ==
                            intel_gtt_chipsets[i].gmch_chip_id) {
                                intel_private.pcidev = pci_dev_get(gpu_pdev);
                                intel_private.driver =
                                        intel_gtt_chipsets[i].gtt_driver;

                                break;
                        }
                } else if (find_gmch(intel_gtt_chipsets[i].gmch_chip_id)) {
                        intel_private.driver =
                                intel_gtt_chipsets[i].gtt_driver;
                        break;
                }
        }

        if (!intel_private.driver)
                return 0;

        intel_private.refcount++;

#if IS_ENABLED(CONFIG_AGP_INTEL)
        if (bridge) {
                bridge->driver = &intel_fake_agp_driver;
                bridge->dev_private_data = &intel_private;
                bridge->dev = bridge_pdev;
        }
#endif

        intel_private.bridge_dev = pci_dev_get(bridge_pdev);

        dev_info(&bridge_pdev->dev, "Intel %s Chipset\n", intel_gtt_chipsets[i].name);

        mask = intel_private.driver->dma_mask_size;
        if (pci_set_dma_mask(intel_private.pcidev, DMA_BIT_MASK(mask)))
                dev_err(&intel_private.pcidev->dev,
                        "set gfx device dma mask %d-bit failed!\n", mask);
        else
                pci_set_consistent_dma_mask(intel_private.pcidev,
                                            DMA_BIT_MASK(mask));

        if (intel_gtt_init() != 0) {
                intel_gmch_remove();

                return 0;
        }

        return 1;
}
EXPORT_SYMBOL(intel_gmch_probe);

void intel_gtt_get(size_t *gtt_total, size_t *stolen_size,
                   phys_addr_t *mappable_base, unsigned long *mappable_end)
{
        *gtt_total = intel_private.gtt_total_entries << PAGE_SHIFT;
        *stolen_size = intel_private.stolen_size;
        *mappable_base = intel_private.gma_bus_addr;
        *mappable_end = intel_private.gtt_mappable_entries << PAGE_SHIFT;
}
EXPORT_SYMBOL(intel_gtt_get);

void intel_gtt_chipset_flush(void)
{
        if (intel_private.driver->chipset_flush)
                intel_private.driver->chipset_flush();
}
EXPORT_SYMBOL(intel_gtt_chipset_flush);

void intel_gmch_remove(void)
{
        if (--intel_private.refcount)
                return;

        if (intel_private.pcidev)
                pci_dev_put(intel_private.pcidev);
        if (intel_private.bridge_dev)
                pci_dev_put(intel_private.bridge_dev);
        intel_private.driver = NULL;
}
EXPORT_SYMBOL(intel_gmch_remove);

MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
MODULE_LICENSE("GPL and additional rights");