// SPDX-License-Identifier: MIT
/*
 * Copyright © 2008-2012 Intel Corporation
 */

#include <linux/errno.h>
#include <linux/mutex.h>

#include <drm/drm_mm.h>
#include <drm/drm_print.h>
#include <drm/intel/display_parent_interface.h>
#include <drm/intel/i915_drm.h>

#include "gem/i915_gem_lmem.h"
#include "gem/i915_gem_region.h"
#include "gt/intel_gt.h"
#include "gt/intel_gt_mcr.h"
#include "gt/intel_gt_regs.h"
#include "gt/intel_region_lmem.h"
#include "i915_drv.h"
#include "i915_gem_stolen.h"
#include "i915_pci.h"
#include "i915_reg.h"
#include "i915_utils.h"
#include "i915_vgpu.h"
#include "intel_mchbar_regs.h"
#include "intel_pci_config.h"

struct intel_stolen_node {
        struct drm_i915_private *i915;
        struct drm_mm_node node;
};

/*
 * The BIOS typically reserves some of the system's memory for the exclusive
 * use of the integrated graphics. This memory is no longer available for
 * use by the OS and so the user finds that his system has less memory
 * available than he put in. We refer to this memory as stolen.
 *
 * The BIOS will allocate its framebuffer from the stolen memory. Our
 * goal is try to reuse that object for our own fbcon which must always
 * be available for panics. Anything else we can reuse the stolen memory
 * for is a boon.
 */

static int __i915_gem_stolen_insert_node_in_range(struct drm_i915_private *i915,
                                                  struct drm_mm_node *node, u64 size,
                                                  unsigned int alignment, u64 start, u64 end)
{
        int ret;

        if (!drm_mm_initialized(&i915->mm.stolen))
                return -ENODEV;

        /* WaSkipStolenMemoryFirstPage:bdw+ */
        if (GRAPHICS_VER(i915) >= 8 && start < 4096)
                start = 4096;

        mutex_lock(&i915->mm.stolen_lock);
        ret = drm_mm_insert_node_in_range(&i915->mm.stolen, node,
                                          size, alignment, 0,
                                          start, end, DRM_MM_INSERT_BEST);
        mutex_unlock(&i915->mm.stolen_lock);

        return ret;
}

static int i915_gem_stolen_insert_node_in_range(struct intel_stolen_node *node, u64 size,
                                                unsigned int alignment, u64 start, u64 end)
{
        return __i915_gem_stolen_insert_node_in_range(node->i915, &node->node,
                                                      size, alignment,
                                                      start, end);
}

static int __i915_gem_stolen_insert_node(struct drm_i915_private *i915,
                                         struct drm_mm_node *node, u64 size,
                                         unsigned int alignment)
{
        return __i915_gem_stolen_insert_node_in_range(i915, node,
                                                      size, alignment,
                                                      I915_GEM_STOLEN_BIAS,
                                                      U64_MAX);
}

static int i915_gem_stolen_insert_node(struct intel_stolen_node *node, u64 size,
                                       unsigned int alignment)
{
        return __i915_gem_stolen_insert_node(node->i915, &node->node, size, alignment);
}

static void __i915_gem_stolen_remove_node(struct drm_i915_private *i915,
                                          struct drm_mm_node *node)
{
        mutex_lock(&i915->mm.stolen_lock);
        drm_mm_remove_node(node);
        mutex_unlock(&i915->mm.stolen_lock);
}

static void i915_gem_stolen_remove_node(struct intel_stolen_node *node)
{
        __i915_gem_stolen_remove_node(node->i915, &node->node);
}

static bool valid_stolen_size(struct drm_i915_private *i915, struct resource *dsm)
{
        return (dsm->start != 0 || HAS_LMEMBAR_SMEM_STOLEN(i915)) && dsm->end > dsm->start;
}

static int adjust_stolen(struct drm_i915_private *i915,
                         struct resource *dsm)
{
        struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
        struct intel_uncore *uncore = ggtt->vm.gt->uncore;

        if (!valid_stolen_size(i915, dsm))
                return -EINVAL;

        /*
         * Make sure we don't clobber the GTT if it's within stolen memory
         *
         * TODO: We have yet too encounter the case where the GTT wasn't at the
         * end of stolen. With that assumption we could simplify this.
         */
        if (GRAPHICS_VER(i915) <= 4 &&
            !IS_G33(i915) && !IS_PINEVIEW(i915) && !IS_G4X(i915)) {
                struct resource stolen[2] = {*dsm, *dsm};
                struct resource ggtt_res;
                resource_size_t ggtt_start;

                ggtt_start = intel_uncore_read(uncore, PGTBL_CTL);
                if (GRAPHICS_VER(i915) == 4)
                        ggtt_start = (ggtt_start & PGTBL_ADDRESS_LO_MASK) |
                                     (ggtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
                else
                        ggtt_start &= PGTBL_ADDRESS_LO_MASK;

                ggtt_res = DEFINE_RES_MEM(ggtt_start, ggtt_total_entries(ggtt) * 4);

                if (ggtt_res.start >= stolen[0].start && ggtt_res.start < stolen[0].end)
                        stolen[0].end = ggtt_res.start;
                if (ggtt_res.end > stolen[1].start && ggtt_res.end <= stolen[1].end)
                        stolen[1].start = ggtt_res.end;

                /* Pick the larger of the two chunks */
                if (resource_size(&stolen[0]) > resource_size(&stolen[1]))
                        *dsm = stolen[0];
                else
                        *dsm = stolen[1];

                if (stolen[0].start != stolen[1].start ||
                    stolen[0].end != stolen[1].end) {
                        drm_dbg(&i915->drm,
                                "GTT within stolen memory at %pR\n",
                                &ggtt_res);
                        drm_dbg(&i915->drm, "Stolen memory adjusted to %pR\n",
                                dsm);
                }
        }

        if (!valid_stolen_size(i915, dsm))
                return -EINVAL;

        return 0;
}

static int request_smem_stolen(struct drm_i915_private *i915,
                               struct resource *dsm)
{
        struct resource *r;

        /*
         * With stolen lmem, we don't need to request system memory for the
         * address range since it's local to the gpu.
         *
         * Starting MTL, in IGFX devices the stolen memory is exposed via
         * LMEMBAR and shall be considered similar to stolen lmem.
         */
        if (HAS_LMEM(i915) || HAS_LMEMBAR_SMEM_STOLEN(i915))
                return 0;

        /*
         * Verify that nothing else uses this physical address. Stolen
         * memory should be reserved by the BIOS and hidden from the
         * kernel. So if the region is already marked as busy, something
         * is seriously wrong.
         */
        r = devm_request_mem_region(i915->drm.dev, dsm->start,
                                    resource_size(dsm),
                                    "Graphics Stolen Memory");
        if (r == NULL) {
                /*
                 * One more attempt but this time requesting region from
                 * start + 1, as we have seen that this resolves the region
                 * conflict with the PCI Bus.
                 * This is a BIOS w/a: Some BIOS wrap stolen in the root
                 * PCI bus, but have an off-by-one error. Hence retry the
                 * reservation starting from 1 instead of 0.
                 * There's also BIOS with off-by-one on the other end.
                 */
                r = devm_request_mem_region(i915->drm.dev, dsm->start + 1,
                                            resource_size(dsm) - 2,
                                            "Graphics Stolen Memory");
                /*
                 * GEN3 firmware likes to smash pci bridges into the stolen
                 * range. Apparently this works.
                 */
                if (!r && GRAPHICS_VER(i915) != 3) {
                        drm_err(&i915->drm,
                                "conflict detected with stolen region: %pR\n",
                                dsm);

                        return -EBUSY;
                }
        }

        return 0;
}

static void i915_gem_cleanup_stolen(struct drm_i915_private *i915)
{
        if (!drm_mm_initialized(&i915->mm.stolen))
                return;

        drm_mm_takedown(&i915->mm.stolen);
}

static void g4x_get_stolen_reserved(struct drm_i915_private *i915,
                                    struct intel_uncore *uncore,
                                    resource_size_t *base,
                                    resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore,
                                        IS_GM45(i915) ?
                                        CTG_STOLEN_RESERVED :
                                        ELK_STOLEN_RESERVED);
        resource_size_t stolen_top = i915->dsm.stolen.end + 1;

        drm_dbg(&i915->drm, "%s_STOLEN_RESERVED = %08x\n",
                IS_GM45(i915) ? "CTG" : "ELK", reg_val);

        if ((reg_val & G4X_STOLEN_RESERVED_ENABLE) == 0)
                return;

        /*
         * Whether ILK really reuses the ELK register for this is unclear.
         * Let's see if we catch anyone with this supposedly enabled on ILK.
         */
        drm_WARN(&i915->drm, GRAPHICS_VER(i915) == 5,
                 "ILK stolen reserved found? 0x%08x\n",
                 reg_val);

        if (!(reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK))
                return;

        *base = (reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK) << 16;
        drm_WARN_ON(&i915->drm,
                    (reg_val & G4X_STOLEN_RESERVED_ADDR1_MASK) < *base);

        *size = stolen_top - *base;
}

static void gen6_get_stolen_reserved(struct drm_i915_private *i915,
                                     struct intel_uncore *uncore,
                                     resource_size_t *base,
                                     resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

        if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
                return;

        *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;

        switch (reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK) {
        case GEN6_STOLEN_RESERVED_1M:
                *size = 1024 * 1024;
                break;
        case GEN6_STOLEN_RESERVED_512K:
                *size = 512 * 1024;
                break;
        case GEN6_STOLEN_RESERVED_256K:
                *size = 256 * 1024;
                break;
        case GEN6_STOLEN_RESERVED_128K:
                *size = 128 * 1024;
                break;
        default:
                *size = 1024 * 1024;
                MISSING_CASE(reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK);
        }
}

static void vlv_get_stolen_reserved(struct drm_i915_private *i915,
                                    struct intel_uncore *uncore,
                                    resource_size_t *base,
                                    resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);
        resource_size_t stolen_top = i915->dsm.stolen.end + 1;

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

        if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
                return;

        switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
        default:
                MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
                fallthrough;
        case GEN7_STOLEN_RESERVED_1M:
                *size = 1024 * 1024;
                break;
        }

        /*
         * On vlv, the ADDR_MASK portion is left as 0 and HW deduces the
         * reserved location as (top - size).
         */
        *base = stolen_top - *size;
}

static void gen7_get_stolen_reserved(struct drm_i915_private *i915,
                                     struct intel_uncore *uncore,
                                     resource_size_t *base,
                                     resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

        if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
                return;

        *base = reg_val & GEN7_STOLEN_RESERVED_ADDR_MASK;

        switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
        case GEN7_STOLEN_RESERVED_1M:
                *size = 1024 * 1024;
                break;
        case GEN7_STOLEN_RESERVED_256K:
                *size = 256 * 1024;
                break;
        default:
                *size = 1024 * 1024;
                MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
        }
}

static void chv_get_stolen_reserved(struct drm_i915_private *i915,
                                    struct intel_uncore *uncore,
                                    resource_size_t *base,
                                    resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

        if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
                return;

        *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;

        switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
        case GEN8_STOLEN_RESERVED_1M:
                *size = 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_2M:
                *size = 2 * 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_4M:
                *size = 4 * 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_8M:
                *size = 8 * 1024 * 1024;
                break;
        default:
                *size = 8 * 1024 * 1024;
                MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
        }
}

static void bdw_get_stolen_reserved(struct drm_i915_private *i915,
                                    struct intel_uncore *uncore,
                                    resource_size_t *base,
                                    resource_size_t *size)
{
        u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);
        resource_size_t stolen_top = i915->dsm.stolen.end + 1;

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

        if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
                return;

        if (!(reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK))
                return;

        *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
        *size = stolen_top - *base;
}

static void icl_get_stolen_reserved(struct drm_i915_private *i915,
                                    struct intel_uncore *uncore,
                                    resource_size_t *base,
                                    resource_size_t *size)
{
        u64 reg_val = intel_uncore_read64(uncore, GEN6_STOLEN_RESERVED);

        drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = 0x%016llx\n", reg_val);

        /* Wa_14019821291 */
        if (MEDIA_VER_FULL(i915) == IP_VER(13, 0)) {
                /*
                 * This workaround is primarily implemented by the BIOS.  We
                 * just need to figure out whether the BIOS has applied the
                 * workaround (meaning the programmed address falls within
                 * the DSM) and, if so, reserve that part of the DSM to
                 * prevent accidental reuse.  The DSM location should be just
                 * below the WOPCM.
                 */
                u64 gscpsmi_base = intel_uncore_read64_2x32(uncore,
                                                            MTL_GSCPSMI_BASEADDR_LSB,
                                                            MTL_GSCPSMI_BASEADDR_MSB);
                if (gscpsmi_base >= i915->dsm.stolen.start &&
                    gscpsmi_base < i915->dsm.stolen.end) {
                        *base = gscpsmi_base;
                        *size = i915->dsm.stolen.end - gscpsmi_base;
                        return;
                }
        }

        switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
        case GEN8_STOLEN_RESERVED_1M:
                *size = 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_2M:
                *size = 2 * 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_4M:
                *size = 4 * 1024 * 1024;
                break;
        case GEN8_STOLEN_RESERVED_8M:
                *size = 8 * 1024 * 1024;
                break;
        default:
                *size = 8 * 1024 * 1024;
                MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
        }

        if (HAS_LMEMBAR_SMEM_STOLEN(i915))
                /* the base is initialized to stolen top so subtract size to get base */
                *base -= *size;
        else
                *base = reg_val & GEN11_STOLEN_RESERVED_ADDR_MASK;
}

/*
 * Initialize i915->dsm.reserved to contain the reserved space within the Data
 * Stolen Memory. This is a range on the top of DSM that is reserved, not to
 * be used by driver, so must be excluded from the region passed to the
 * allocator later. In the spec this is also called as WOPCM.
 *
 * Our expectation is that the reserved space is at the top of the stolen
 * region, as it has been the case for every platform, and *never* at the
 * bottom, so the calculation here can be simplified.
 */
static int init_reserved_stolen(struct drm_i915_private *i915)
{
        struct intel_uncore *uncore = &i915->uncore;
        resource_size_t reserved_base, stolen_top;
        resource_size_t reserved_size;
        int ret = 0;

        stolen_top = i915->dsm.stolen.end + 1;
        reserved_base = stolen_top;
        reserved_size = 0;

        if (GRAPHICS_VER(i915) >= 11) {
                icl_get_stolen_reserved(i915, uncore,
                                        &reserved_base, &reserved_size);
        } else if (GRAPHICS_VER(i915) >= 8) {
                if (IS_CHERRYVIEW(i915) || IS_BROXTON(i915) || IS_GEMINILAKE(i915))
                        chv_get_stolen_reserved(i915, uncore,
                                                &reserved_base, &reserved_size);
                else
                        bdw_get_stolen_reserved(i915, uncore,
                                                &reserved_base, &reserved_size);
        } else if (GRAPHICS_VER(i915) >= 7) {
                if (IS_VALLEYVIEW(i915))
                        vlv_get_stolen_reserved(i915, uncore,
                                                &reserved_base, &reserved_size);
                else
                        gen7_get_stolen_reserved(i915, uncore,
                                                 &reserved_base, &reserved_size);
        } else if (GRAPHICS_VER(i915) >= 6) {
                gen6_get_stolen_reserved(i915, uncore,
                                         &reserved_base, &reserved_size);
        } else if (GRAPHICS_VER(i915) >= 5 || IS_G4X(i915)) {
                g4x_get_stolen_reserved(i915, uncore,
                                        &reserved_base, &reserved_size);
        }

        /* No reserved stolen */
        if (reserved_base == stolen_top)
                goto bail_out;

        if (!reserved_base) {
                drm_err(&i915->drm,
                        "inconsistent reservation %pa + %pa; ignoring\n",
                        &reserved_base, &reserved_size);
                ret = -EINVAL;
                goto bail_out;
        }

        i915->dsm.reserved = DEFINE_RES_MEM(reserved_base, reserved_size);

        if (!resource_contains(&i915->dsm.stolen, &i915->dsm.reserved)) {
                drm_err(&i915->drm,
                        "Stolen reserved area %pR outside stolen memory %pR\n",
                        &i915->dsm.reserved, &i915->dsm.stolen);
                ret = -EINVAL;
                goto bail_out;
        }

        return 0;

bail_out:
        i915->dsm.reserved = DEFINE_RES_MEM(reserved_base, 0);

        return ret;
}

static int i915_gem_init_stolen(struct intel_memory_region *mem)
{
        struct drm_i915_private *i915 = mem->i915;

        mutex_init(&i915->mm.stolen_lock);

        if (intel_vgpu_active(i915)) {
                drm_notice(&i915->drm,
                           "%s, disabling use of stolen memory\n",
                           "iGVT-g active");
                return -ENOSPC;
        }

        if (i915_vtd_active(i915) && GRAPHICS_VER(i915) < 8) {
                drm_notice(&i915->drm,
                           "%s, disabling use of stolen memory\n",
                           "DMAR active");
                return -ENOSPC;
        }

        if (adjust_stolen(i915, &mem->region))
                return -ENOSPC;

        if (request_smem_stolen(i915, &mem->region))
                return -ENOSPC;

        i915->dsm.stolen = mem->region;

        if (init_reserved_stolen(i915))
                return -ENOSPC;

        /* Exclude the reserved region from driver use */
        mem->region.end = i915->dsm.reserved.start - 1;
        mem->io = DEFINE_RES_MEM(mem->io.start,
                                 min(resource_size(&mem->io),
                                     resource_size(&mem->region)));

        i915->dsm.usable_size = resource_size(&mem->region);

        drm_dbg(&i915->drm,
                "Memory reserved for graphics device: %lluK, usable: %lluK\n",
                (u64)resource_size(&i915->dsm.stolen) >> 10,
                (u64)i915->dsm.usable_size >> 10);

        if (i915->dsm.usable_size == 0)
                return -ENOSPC;

        /* Basic memrange allocator for stolen space. */
        drm_mm_init(&i915->mm.stolen, 0, i915->dsm.usable_size);

        /*
         * Access to stolen lmem beyond certain size for MTL A0 stepping
         * would crash the machine. Disable stolen lmem for userspace access
         * by setting usable_size to zero.
         */
        if (IS_METEORLAKE(i915) && INTEL_REVID(i915) == 0x0)
                i915->dsm.usable_size = 0;

        return 0;
}

static void dbg_poison(struct i915_ggtt *ggtt,
                       dma_addr_t addr, resource_size_t size,
                       u8 x)
{
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
        if (!drm_mm_node_allocated(&ggtt->error_capture))
                return;

        if (ggtt->vm.bind_async_flags & I915_VMA_GLOBAL_BIND)
                return; /* beware stop_machine() inversion */

        GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));

        mutex_lock(&ggtt->error_mutex);
        while (size) {
                void __iomem *s;

                ggtt->vm.insert_page(&ggtt->vm, addr,
                                     ggtt->error_capture.start,
                                     i915_gem_get_pat_index(ggtt->vm.i915,
                                                            I915_CACHE_NONE),
                                     0);
                mb();

                s = io_mapping_map_wc(&ggtt->iomap,
                                      ggtt->error_capture.start,
                                      PAGE_SIZE);
                memset_io(s, x, PAGE_SIZE);
                io_mapping_unmap(s);

                addr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }
        mb();
        ggtt->vm.clear_range(&ggtt->vm, ggtt->error_capture.start, PAGE_SIZE);
        mutex_unlock(&ggtt->error_mutex);
#endif
}

static struct sg_table *
i915_pages_create_for_stolen(struct drm_device *dev,
                             resource_size_t offset, resource_size_t size)
{
        struct drm_i915_private *i915 = to_i915(dev);
        struct sg_table *st;
        struct scatterlist *sg;

        GEM_BUG_ON(range_overflows(offset, size, resource_size(&i915->dsm.stolen)));

        /* We hide that we have no struct page backing our stolen object
         * by wrapping the contiguous physical allocation with a fake
         * dma mapping in a single scatterlist.
         */

        st = kmalloc_obj(*st);
        if (st == NULL)
                return ERR_PTR(-ENOMEM);

        if (sg_alloc_table(st, 1, GFP_KERNEL)) {
                kfree(st);
                return ERR_PTR(-ENOMEM);
        }

        sg = st->sgl;
        sg->offset = 0;
        sg->length = size;

        sg_dma_address(sg) = (dma_addr_t)i915->dsm.stolen.start + offset;
        sg_dma_len(sg) = size;

        return st;
}

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
{
        struct drm_i915_private *i915 = to_i915(obj->base.dev);
        struct sg_table *pages =
                i915_pages_create_for_stolen(obj->base.dev,
                                             obj->stolen->start,
                                             obj->stolen->size);
        if (IS_ERR(pages))
                return PTR_ERR(pages);

        dbg_poison(to_gt(i915)->ggtt,
                   sg_dma_address(pages->sgl),
                   sg_dma_len(pages->sgl),
                   POISON_INUSE);

        __i915_gem_object_set_pages(obj, pages);

        return 0;
}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj,
                                             struct sg_table *pages)
{
        struct drm_i915_private *i915 = to_i915(obj->base.dev);
        /* Should only be called from i915_gem_object_release_stolen() */

        dbg_poison(to_gt(i915)->ggtt,
                   sg_dma_address(pages->sgl),
                   sg_dma_len(pages->sgl),
                   POISON_FREE);

        sg_free_table(pages);
        kfree(pages);
}

static void
i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
{
        struct drm_i915_private *i915 = to_i915(obj->base.dev);
        struct drm_mm_node *stolen = fetch_and_zero(&obj->stolen);

        GEM_BUG_ON(!stolen);
        __i915_gem_stolen_remove_node(i915, stolen);
        kfree(stolen);

        i915_gem_object_release_memory_region(obj);
}

static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
        .name = "i915_gem_object_stolen",
        .get_pages = i915_gem_object_get_pages_stolen,
        .put_pages = i915_gem_object_put_pages_stolen,
        .release = i915_gem_object_release_stolen,
};

static int __i915_gem_object_create_stolen(struct intel_memory_region *mem,
                                           struct drm_i915_gem_object *obj,
                                           struct drm_mm_node *stolen)
{
        static struct lock_class_key lock_class;
        unsigned int cache_level;
        unsigned int flags;
        int err;

        /*
         * Stolen objects are always physically contiguous since we just
         * allocate one big block underneath using the drm_mm range allocator.
         */
        flags = I915_BO_ALLOC_CONTIGUOUS;

        drm_gem_private_object_init(&mem->i915->drm, &obj->base, stolen->size);
        i915_gem_object_init(obj, &i915_gem_object_stolen_ops, &lock_class, flags);

        obj->stolen = stolen;
        obj->read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
        cache_level = HAS_LLC(mem->i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
        i915_gem_object_set_cache_coherency(obj, cache_level);

        if (WARN_ON(!i915_gem_object_trylock(obj, NULL)))
                return -EBUSY;

        i915_gem_object_init_memory_region(obj, mem);

        err = i915_gem_object_pin_pages(obj);
        if (err)
                i915_gem_object_release_memory_region(obj);
        i915_gem_object_unlock(obj);

        return err;
}

static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,
                                        struct drm_i915_gem_object *obj,
                                        resource_size_t offset,
                                        resource_size_t size,
                                        resource_size_t page_size,
                                        unsigned int flags)
{
        struct drm_i915_private *i915 = mem->i915;
        struct drm_mm_node *stolen;
        int ret;

        if (!drm_mm_initialized(&i915->mm.stolen))
                return -ENODEV;

        if (size == 0)
                return -EINVAL;

        /*
         * With discrete devices, where we lack a mappable aperture there is no
         * possible way to ever access this memory on the CPU side.
         */
        if (mem->type == INTEL_MEMORY_STOLEN_LOCAL && !resource_size(&mem->io) &&
            !(flags & I915_BO_ALLOC_GPU_ONLY))
                return -ENOSPC;

        stolen = kzalloc_obj(*stolen);
        if (!stolen)
                return -ENOMEM;

        if (offset != I915_BO_INVALID_OFFSET) {
                drm_dbg(&i915->drm,
                        "creating preallocated stolen object: stolen_offset=%pa, size=%pa\n",
                        &offset, &size);

                stolen->start = offset;
                stolen->size = size;
                mutex_lock(&i915->mm.stolen_lock);
                ret = drm_mm_reserve_node(&i915->mm.stolen, stolen);
                mutex_unlock(&i915->mm.stolen_lock);
        } else {
                ret = __i915_gem_stolen_insert_node(i915, stolen, size,
                                                    mem->min_page_size);
        }
        if (ret)
                goto err_free;

        ret = __i915_gem_object_create_stolen(mem, obj, stolen);
        if (ret)
                goto err_remove;

        return 0;

err_remove:
        __i915_gem_stolen_remove_node(i915, stolen);
err_free:
        kfree(stolen);
        return ret;
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen(struct drm_i915_private *i915,
                              resource_size_t size)
{
        return i915_gem_object_create_region(i915->mm.stolen_region, size, 0, 0);
}

static int init_stolen_smem(struct intel_memory_region *mem)
{
        int err;

        /*
         * Initialise stolen early so that we may reserve preallocated
         * objects for the BIOS to KMS transition.
         */
        err = i915_gem_init_stolen(mem);
        if (err)
                drm_dbg(&mem->i915->drm, "Skip stolen region: failed to setup\n");

        return 0;
}

static int release_stolen_smem(struct intel_memory_region *mem)
{
        i915_gem_cleanup_stolen(mem->i915);
        return 0;
}

static const struct intel_memory_region_ops i915_region_stolen_smem_ops = {
        .init = init_stolen_smem,
        .release = release_stolen_smem,
        .init_object = _i915_gem_object_stolen_init,
};

static int init_stolen_lmem(struct intel_memory_region *mem)
{
        int err;

        if (GEM_WARN_ON(resource_size(&mem->region) == 0))
                return 0;

        err = i915_gem_init_stolen(mem);
        if (err) {
                drm_dbg(&mem->i915->drm, "Skip stolen region: failed to setup\n");
                return 0;
        }

        if (resource_size(&mem->io) &&
            !io_mapping_init_wc(&mem->iomap, mem->io.start, resource_size(&mem->io)))
                goto err_cleanup;

        return 0;

err_cleanup:
        i915_gem_cleanup_stolen(mem->i915);
        return err;
}

static int release_stolen_lmem(struct intel_memory_region *mem)
{
        if (resource_size(&mem->io))
                io_mapping_fini(&mem->iomap);
        i915_gem_cleanup_stolen(mem->i915);
        return 0;
}

static const struct intel_memory_region_ops i915_region_stolen_lmem_ops = {
        .init = init_stolen_lmem,
        .release = release_stolen_lmem,
        .init_object = _i915_gem_object_stolen_init,
};

static int mtl_get_gms_size(struct intel_uncore *uncore)
{
        u16 ggc, gms;

        ggc = intel_uncore_read16(uncore, GGC);

        /* check GGMS, should be fixed 0x3 (8MB) */
        if ((ggc & GGMS_MASK) != GGMS_MASK)
                return -EIO;

        /* return valid GMS value, -EIO if invalid */
        gms = REG_FIELD_GET(GMS_MASK, ggc);
        switch (gms) {
        case 0x0 ... 0x04:
                return gms * 32;
        case 0xf0 ... 0xfe:
                return (gms - 0xf0 + 1) * 4;
        default:
                MISSING_CASE(gms);
                return -EIO;
        }
}

struct intel_memory_region *
i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type,
                           u16 instance)
{
        struct intel_uncore *uncore = &i915->uncore;
        struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
        resource_size_t dsm_size, dsm_base, lmem_size;
        struct intel_memory_region *mem;
        resource_size_t io_start, io_size;
        resource_size_t min_page_size;
        int ret;

        if (WARN_ON_ONCE(instance))
                return ERR_PTR(-ENODEV);

        if (!i915_pci_resource_valid(pdev, GEN12_LMEM_BAR))
                return ERR_PTR(-ENXIO);

        if (HAS_LMEMBAR_SMEM_STOLEN(i915) || IS_DG1(i915)) {
                lmem_size = pci_resource_len(pdev, GEN12_LMEM_BAR);
        } else {
                resource_size_t lmem_range;

                lmem_range = intel_gt_mcr_read_any(to_gt(i915), XEHP_TILE0_ADDR_RANGE) & 0xFFFF;
                lmem_size = lmem_range >> XEHP_TILE_LMEM_RANGE_SHIFT;
                lmem_size *= SZ_1G;
        }

        if (HAS_LMEMBAR_SMEM_STOLEN(i915)) {
                /*
                 * MTL dsm size is in GGC register.
                 * Also MTL uses offset to GSMBASE in ptes, so i915
                 * uses dsm_base = 8MBs to setup stolen region, since
                 * DSMBASE = GSMBASE + 8MB.
                 */
                ret = mtl_get_gms_size(uncore);
                if (ret < 0) {
                        drm_err(&i915->drm, "invalid MTL GGC register setting\n");
                        return ERR_PTR(ret);
                }

                dsm_base = SZ_8M;
                dsm_size = (resource_size_t)(ret * SZ_1M);

                GEM_BUG_ON(pci_resource_len(pdev, GEN12_LMEM_BAR) != SZ_256M);
                GEM_BUG_ON((dsm_base + dsm_size) > lmem_size);
        } else {
                /* Use DSM base address instead for stolen memory */
                dsm_base = intel_uncore_read64(uncore, GEN6_DSMBASE) & GEN11_BDSM_MASK;
                if (lmem_size < dsm_base) {
                        drm_dbg(&i915->drm,
                                "Disabling stolen memory support due to OOB placement: lmem_size = %pa vs dsm_base = %pa\n",
                                &lmem_size, &dsm_base);
                        return NULL;
                }
                dsm_size = ALIGN_DOWN(lmem_size - dsm_base, SZ_1M);
        }

        if (i915_direct_stolen_access(i915)) {
                drm_dbg(&i915->drm, "Using direct DSM access\n");
                io_start = intel_uncore_read64(uncore, GEN6_DSMBASE) & GEN11_BDSM_MASK;
                io_size = dsm_size;
        } else if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) {
                io_start = 0;
                io_size = 0;
        } else {
                io_start = pci_resource_start(pdev, GEN12_LMEM_BAR) + dsm_base;
                io_size = dsm_size;
        }

        min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K :
                                                I915_GTT_PAGE_SIZE_4K;

        mem = intel_memory_region_create(i915, dsm_base, dsm_size,
                                         min_page_size,
                                         io_start, io_size,
                                         type, instance,
                                         &i915_region_stolen_lmem_ops);
        if (IS_ERR(mem))
                return mem;

        intel_memory_region_set_name(mem, "stolen-local");

        mem->private = true;

        return mem;
}

struct intel_memory_region*
i915_gem_stolen_smem_setup(struct drm_i915_private *i915, u16 type,
                           u16 instance)
{
        struct intel_memory_region *mem;

        mem = intel_memory_region_create(i915,
                                         intel_graphics_stolen_res.start,
                                         resource_size(&intel_graphics_stolen_res),
                                         PAGE_SIZE, 0, 0, type, instance,
                                         &i915_region_stolen_smem_ops);
        if (IS_ERR(mem))
                return mem;

        intel_memory_region_set_name(mem, "stolen-system");

        mem->private = true;

        return mem;
}

bool i915_gem_object_is_stolen(const struct drm_i915_gem_object *obj)
{
        return obj->ops == &i915_gem_object_stolen_ops;
}

static bool i915_gem_stolen_initialized(struct drm_device *drm)
{
        struct drm_i915_private *i915 = to_i915(drm);

        return drm_mm_initialized(&i915->mm.stolen);
}

static u64 i915_gem_stolen_area_address(struct drm_device *drm)
{
        struct drm_i915_private *i915 = to_i915(drm);

        return i915->dsm.stolen.start;
}

static u64 i915_gem_stolen_area_size(struct drm_device *drm)
{
        struct drm_i915_private *i915 = to_i915(drm);

        return resource_size(&i915->dsm.stolen);
}

static u64 i915_gem_stolen_node_offset(const struct intel_stolen_node *node)
{
        return node->node.start;
}

static u64 i915_gem_stolen_node_address(const struct intel_stolen_node *node)
{
        struct drm_i915_private *i915 = node->i915;

        return i915->dsm.stolen.start + i915_gem_stolen_node_offset(node);
}

static bool i915_gem_stolen_node_allocated(const struct intel_stolen_node *node)
{
        return drm_mm_node_allocated(&node->node);
}

static u64 i915_gem_stolen_node_size(const struct intel_stolen_node *node)
{
        return node->node.size;
}

static struct intel_stolen_node *i915_gem_stolen_node_alloc(struct drm_device *drm)
{
        struct drm_i915_private *i915 = to_i915(drm);
        struct intel_stolen_node *node;

        node = kzalloc_obj(*node);
        if (!node)
                return NULL;

        node->i915 = i915;

        return node;
}

static void i915_gem_stolen_node_free(const struct intel_stolen_node *node)
{
        kfree(node);
}

const struct intel_display_stolen_interface i915_display_stolen_interface = {
        .insert_node_in_range = i915_gem_stolen_insert_node_in_range,
        .insert_node = i915_gem_stolen_insert_node,
        .remove_node = i915_gem_stolen_remove_node,
        .initialized = i915_gem_stolen_initialized,
        .node_allocated = i915_gem_stolen_node_allocated,
        .node_offset = i915_gem_stolen_node_offset,
        .area_address = i915_gem_stolen_area_address,
        .area_size = i915_gem_stolen_area_size,
        .node_address = i915_gem_stolen_node_address,
        .node_size = i915_gem_stolen_node_size,
        .node_alloc = i915_gem_stolen_node_alloc,
        .node_free = i915_gem_stolen_node_free,
};