/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2017 Intel Corporation
 */

#include <linux/prime_numbers.h>
#include <linux/string_helpers.h>
#include <linux/swap.h>

#include "i915_selftest.h"

#include "gem/i915_gem_internal.h"
#include "gem/i915_gem_lmem.h"
#include "gem/i915_gem_pm.h"
#include "gem/i915_gem_region.h"

#include "gt/intel_gt.h"

#include "igt_gem_utils.h"
#include "mock_context.h"

#include "selftests/mock_drm.h"
#include "selftests/mock_gem_device.h"
#include "selftests/mock_region.h"
#include "selftests/i915_random.h"

static struct i915_gem_context *hugepage_ctx(struct drm_i915_private *i915,
                                             struct file *file)
{
        struct i915_gem_context *ctx = live_context(i915, file);
        struct i915_address_space *vm;

        if (IS_ERR(ctx))
                return ctx;

        vm = ctx->vm;
        if (vm)
                WRITE_ONCE(vm->scrub_64K, true);

        return ctx;
}

static const unsigned int page_sizes[] = {
        I915_GTT_PAGE_SIZE_2M,
        I915_GTT_PAGE_SIZE_64K,
        I915_GTT_PAGE_SIZE_4K,
};

static unsigned int get_largest_page_size(struct drm_i915_private *i915,
                                          u64 rem)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(page_sizes); ++i) {
                unsigned int page_size = page_sizes[i];

                if (HAS_PAGE_SIZES(i915, page_size) && rem >= page_size)
                        return page_size;
        }

        return 0;
}

static void huge_pages_free_pages(struct sg_table *st)
{
        struct scatterlist *sg;

        for (sg = st->sgl; sg; sg = __sg_next(sg)) {
                if (sg_page(sg))
                        __free_pages(sg_page(sg), get_order(sg->length));
        }

        sg_free_table(st);
        kfree(st);
}

static int get_huge_pages(struct drm_i915_gem_object *obj)
{
#define GFP (GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY)
        unsigned int page_mask = obj->mm.page_mask;
        struct sg_table *st;
        struct scatterlist *sg;
        unsigned int sg_page_sizes;
        u64 rem;

        /* restricted by sg_alloc_table */
        if (overflows_type(obj->base.size >> PAGE_SHIFT, unsigned int))
                return -E2BIG;

        st = kmalloc_obj(*st, GFP);
        if (!st)
                return -ENOMEM;

        if (sg_alloc_table(st, obj->base.size >> PAGE_SHIFT, GFP)) {
                kfree(st);
                return -ENOMEM;
        }

        rem = obj->base.size;
        sg = st->sgl;
        st->nents = 0;
        sg_page_sizes = 0;

        /*
         * Our goal here is simple, we want to greedily fill the object from
         * largest to smallest page-size, while ensuring that we use *every*
         * page-size as per the given page-mask.
         */
        do {
                unsigned int bit = ilog2(page_mask);
                unsigned int page_size = BIT(bit);
                int order = get_order(page_size);

                do {
                        struct page *page;

                        GEM_BUG_ON(order > MAX_PAGE_ORDER);
                        page = alloc_pages(GFP | __GFP_ZERO, order);
                        if (!page)
                                goto err;

                        sg_set_page(sg, page, page_size, 0);
                        sg_page_sizes |= page_size;
                        st->nents++;

                        rem -= page_size;
                        if (!rem) {
                                sg_mark_end(sg);
                                break;
                        }

                        sg = __sg_next(sg);
                } while ((rem - ((page_size-1) & page_mask)) >= page_size);

                page_mask &= (page_size-1);
        } while (page_mask);

        if (i915_gem_gtt_prepare_pages(obj, st))
                goto err;

        GEM_BUG_ON(sg_page_sizes != obj->mm.page_mask);
        __i915_gem_object_set_pages(obj, st);

        return 0;

err:
        sg_set_page(sg, NULL, 0, 0);
        sg_mark_end(sg);
        huge_pages_free_pages(st);

        return -ENOMEM;
}

static void put_huge_pages(struct drm_i915_gem_object *obj,
                           struct sg_table *pages)
{
        i915_gem_gtt_finish_pages(obj, pages);
        huge_pages_free_pages(pages);

        obj->mm.dirty = false;

        __start_cpu_write(obj);
}

static const struct drm_i915_gem_object_ops huge_page_ops = {
        .name = "huge-gem",
        .flags = I915_GEM_OBJECT_IS_SHRINKABLE,
        .get_pages = get_huge_pages,
        .put_pages = put_huge_pages,
};

static struct drm_i915_gem_object *
huge_pages_object(struct drm_i915_private *i915,
                  u64 size,
                  unsigned int page_mask)
{
        static struct lock_class_key lock_class;
        struct drm_i915_gem_object *obj;
        unsigned int cache_level;

        GEM_BUG_ON(!size);
        GEM_BUG_ON(!IS_ALIGNED(size, BIT(__ffs(page_mask))));

        if (size >> PAGE_SHIFT > INT_MAX)
                return ERR_PTR(-E2BIG);

        if (overflows_type(size, obj->base.size))
                return ERR_PTR(-E2BIG);

        obj = i915_gem_object_alloc();
        if (!obj)
                return ERR_PTR(-ENOMEM);

        drm_gem_private_object_init(&i915->drm, &obj->base, size);
        i915_gem_object_init(obj, &huge_page_ops, &lock_class, 0);
        obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE;
        i915_gem_object_set_volatile(obj);

        obj->write_domain = I915_GEM_DOMAIN_CPU;
        obj->read_domains = I915_GEM_DOMAIN_CPU;

        cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
        i915_gem_object_set_cache_coherency(obj, cache_level);

        obj->mm.page_mask = page_mask;

        return obj;
}

static int fake_get_huge_pages(struct drm_i915_gem_object *obj)
{
        struct drm_i915_private *i915 = to_i915(obj->base.dev);
        const u64 max_len = rounddown_pow_of_two(UINT_MAX);
        struct sg_table *st;
        struct scatterlist *sg;
        u64 rem;

        /* restricted by sg_alloc_table */
        if (overflows_type(obj->base.size >> PAGE_SHIFT, unsigned int))
                return -E2BIG;

        st = kmalloc_obj(*st, GFP);
        if (!st)
                return -ENOMEM;

        if (sg_alloc_table(st, obj->base.size >> PAGE_SHIFT, GFP)) {
                kfree(st);
                return -ENOMEM;
        }

        /* Use optimal page sized chunks to fill in the sg table */
        rem = obj->base.size;
        sg = st->sgl;
        st->nents = 0;
        do {
                unsigned int page_size = get_largest_page_size(i915, rem);
                unsigned int len = min(page_size * div_u64(rem, page_size),
                                       max_len);

                GEM_BUG_ON(!page_size);

                sg->offset = 0;
                sg->length = len;
                sg_dma_len(sg) = len;
                sg_dma_address(sg) = page_size;

                st->nents++;

                rem -= len;
                if (!rem) {
                        sg_mark_end(sg);
                        break;
                }

                sg = sg_next(sg);
        } while (1);

        i915_sg_trim(st);

        __i915_gem_object_set_pages(obj, st);

        return 0;
}

static int fake_get_huge_pages_single(struct drm_i915_gem_object *obj)
{
        struct drm_i915_private *i915 = to_i915(obj->base.dev);
        struct sg_table *st;
        struct scatterlist *sg;
        unsigned int page_size;

        st = kmalloc_obj(*st, GFP);
        if (!st)
                return -ENOMEM;

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

        sg = st->sgl;
        st->nents = 1;

        page_size = get_largest_page_size(i915, obj->base.size);
        GEM_BUG_ON(!page_size);

        sg->offset = 0;
        sg->length = obj->base.size;
        sg_dma_len(sg) = obj->base.size;
        sg_dma_address(sg) = page_size;

        __i915_gem_object_set_pages(obj, st);

        return 0;
#undef GFP
}

static void fake_free_huge_pages(struct drm_i915_gem_object *obj,
                                 struct sg_table *pages)
{
        sg_free_table(pages);
        kfree(pages);
}

static void fake_put_huge_pages(struct drm_i915_gem_object *obj,
                                struct sg_table *pages)
{
        fake_free_huge_pages(obj, pages);
        obj->mm.dirty = false;
}

static const struct drm_i915_gem_object_ops fake_ops = {
        .name = "fake-gem",
        .flags = I915_GEM_OBJECT_IS_SHRINKABLE,
        .get_pages = fake_get_huge_pages,
        .put_pages = fake_put_huge_pages,
};

static const struct drm_i915_gem_object_ops fake_ops_single = {
        .name = "fake-gem",
        .flags = I915_GEM_OBJECT_IS_SHRINKABLE,
        .get_pages = fake_get_huge_pages_single,
        .put_pages = fake_put_huge_pages,
};

static struct drm_i915_gem_object *
fake_huge_pages_object(struct drm_i915_private *i915, u64 size, bool single)
{
        static struct lock_class_key lock_class;
        struct drm_i915_gem_object *obj;

        GEM_BUG_ON(!size);
        GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));

        if (size >> PAGE_SHIFT > UINT_MAX)
                return ERR_PTR(-E2BIG);

        if (overflows_type(size, obj->base.size))
                return ERR_PTR(-E2BIG);

        obj = i915_gem_object_alloc();
        if (!obj)
                return ERR_PTR(-ENOMEM);

        drm_gem_private_object_init(&i915->drm, &obj->base, size);

        if (single)
                i915_gem_object_init(obj, &fake_ops_single, &lock_class, 0);
        else
                i915_gem_object_init(obj, &fake_ops, &lock_class, 0);

        i915_gem_object_set_volatile(obj);

        obj->write_domain = I915_GEM_DOMAIN_CPU;
        obj->read_domains = I915_GEM_DOMAIN_CPU;
        obj->pat_index = i915_gem_get_pat_index(i915, I915_CACHE_NONE);

        return obj;
}

static int igt_check_page_sizes(struct i915_vma *vma)
{
        struct drm_i915_private *i915 = vma->vm->i915;
        unsigned int supported = RUNTIME_INFO(i915)->page_sizes;
        struct drm_i915_gem_object *obj = vma->obj;
        int err;

        /* We have to wait for the async bind to complete before our asserts */
        err = i915_vma_sync(vma);
        if (err)
                return err;

        if (!HAS_PAGE_SIZES(i915, vma->page_sizes.sg)) {
                pr_err("unsupported page_sizes.sg=%u, supported=%u\n",
                       vma->page_sizes.sg & ~supported, supported);
                err = -EINVAL;
        }

        if (!HAS_PAGE_SIZES(i915, vma->resource->page_sizes_gtt)) {
                pr_err("unsupported page_sizes.gtt=%u, supported=%u\n",
                       vma->resource->page_sizes_gtt & ~supported, supported);
                err = -EINVAL;
        }

        if (vma->page_sizes.phys != obj->mm.page_sizes.phys) {
                pr_err("vma->page_sizes.phys(%u) != obj->mm.page_sizes.phys(%u)\n",
                       vma->page_sizes.phys, obj->mm.page_sizes.phys);
                err = -EINVAL;
        }

        if (vma->page_sizes.sg != obj->mm.page_sizes.sg) {
                pr_err("vma->page_sizes.sg(%u) != obj->mm.page_sizes.sg(%u)\n",
                       vma->page_sizes.sg, obj->mm.page_sizes.sg);
                err = -EINVAL;
        }

        /*
         * The dma-api is like a box of chocolates when it comes to the
         * alignment of dma addresses, however for LMEM we have total control
         * and so can guarantee alignment, likewise when we allocate our blocks
         * they should appear in descending order, and if we know that we align
         * to the largest page size for the GTT address, we should be able to
         * assert that if we see 2M physical pages then we should also get 2M
         * GTT pages. If we don't then something might be wrong in our
         * construction of the backing pages.
         *
         * Maintaining alignment is required to utilise huge pages in the ppGGT.
         */
        if (i915_gem_object_is_lmem(obj) &&
            IS_ALIGNED(i915_vma_offset(vma), SZ_2M) &&
            vma->page_sizes.sg & SZ_2M &&
            vma->resource->page_sizes_gtt < SZ_2M) {
                pr_err("gtt pages mismatch for LMEM, expected 2M GTT pages, sg(%u), gtt(%u)\n",
                       vma->page_sizes.sg, vma->resource->page_sizes_gtt);
                err = -EINVAL;
        }

        return err;
}

static int igt_mock_exhaust_device_supported_pages(void *arg)
{
        struct i915_ppgtt *ppgtt = arg;
        struct drm_i915_private *i915 = ppgtt->vm.i915;
        unsigned int saved_mask = RUNTIME_INFO(i915)->page_sizes;
        struct drm_i915_gem_object *obj;
        struct i915_vma *vma;
        int i, j, single;
        int err;

        /*
         * Sanity check creating objects with every valid page support
         * combination for our mock device.
         */

        for (i = 1; i < BIT(ARRAY_SIZE(page_sizes)); i++) {
                unsigned int combination = SZ_4K; /* Required for ppGTT */

                for (j = 0; j < ARRAY_SIZE(page_sizes); j++) {
                        if (i & BIT(j))
                                combination |= page_sizes[j];
                }

                RUNTIME_INFO(i915)->page_sizes = combination;

                for (single = 0; single <= 1; ++single) {
                        obj = fake_huge_pages_object(i915, combination, !!single);
                        if (IS_ERR(obj)) {
                                err = PTR_ERR(obj);
                                goto out_device;
                        }

                        if (obj->base.size != combination) {
                                pr_err("obj->base.size=%zu, expected=%u\n",
                                       obj->base.size, combination);
                                err = -EINVAL;
                                goto out_put;
                        }

                        vma = i915_vma_instance(obj, &ppgtt->vm, NULL);
                        if (IS_ERR(vma)) {
                                err = PTR_ERR(vma);
                                goto out_put;
                        }

                        err = i915_vma_pin(vma, 0, 0, PIN_USER);
                        if (err)
                                goto out_put;

                        err = igt_check_page_sizes(vma);

                        if (vma->page_sizes.sg != combination) {
                                pr_err("page_sizes.sg=%u, expected=%u\n",
                                       vma->page_sizes.sg, combination);
                                err = -EINVAL;
                        }

                        i915_vma_unpin(vma);
                        i915_gem_object_put(obj);

                        if (err)
                                goto out_device;
                }
        }

        goto out_device;

out_put:
        i915_gem_object_put(obj);
out_device:
        RUNTIME_INFO(i915)->page_sizes = saved_mask;

        return err;
}

static int igt_mock_memory_region_huge_pages(void *arg)
{
        const unsigned int flags[] = { 0, I915_BO_ALLOC_CONTIGUOUS };
        struct i915_ppgtt *ppgtt = arg;
        struct drm_i915_private *i915 = ppgtt->vm.i915;
        unsigned long supported = RUNTIME_INFO(i915)->page_sizes;
        struct intel_memory_region *mem;
        struct drm_i915_gem_object *obj;
        struct i915_vma *vma;
        int bit;
        int err = 0;

        mem = mock_region_create(i915, 0, SZ_2G, I915_GTT_PAGE_SIZE_4K, 0, 0);
        if (IS_ERR(mem)) {
                pr_err("%s failed to create memory region\n", __func__);
                return PTR_ERR(mem);
        }

        for_each_set_bit(bit, &supported, ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) {
                unsigned int page_size = BIT(bit);
                resource_size_t phys;
                int i;

                for (i = 0; i < ARRAY_SIZE(flags); ++i) {
                        obj = i915_gem_object_create_region(mem,
                                                            page_size, page_size,
                                                            flags[i]);
                        if (IS_ERR(obj)) {
                                err = PTR_ERR(obj);
                                goto out_region;
                        }

                        vma = i915_vma_instance(obj, &ppgtt->vm, NULL);
                        if (IS_ERR(vma)) {
                                err = PTR_ERR(vma);
                                goto out_put;
                        }

                        err = i915_vma_pin(vma, 0, 0, PIN_USER);
                        if (err)
                                goto out_put;

                        err = igt_check_page_sizes(vma);
                        if (err)
                                goto out_unpin;

                        phys = i915_gem_object_get_dma_address(obj, 0);
                        if (!IS_ALIGNED(phys, page_size)) {
                                pr_err("%s addr misaligned(%pa) page_size=%u\n",
                                       __func__, &phys, page_size);
                                err = -EINVAL;
                                goto out_unpin;
                        }

                        if (vma->resource->page_sizes_gtt != page_size) {
                                pr_err("%s page_sizes.gtt=%u, expected=%u\n",
                                       __func__, vma->resource->page_sizes_gtt,
                                       page_size);
                                err = -EINVAL;
                                goto out_unpin;
                        }

                        i915_vma_unpin(vma);
                        __i915_gem_object_put_pages(obj);
                        i915_gem_object_put(obj);
                }
        }

        goto out_region;

out_unpin:
        i915_vma_unpin(vma);
out_put:
        i915_gem_object_put(obj);
out_region:
        intel_memory_region_destroy(mem);
        return err;
}

static int igt_mock_ppgtt_misaligned_dma(void *arg)
{
        struct i915_ppgtt *ppgtt = arg;
        struct drm_i915_private *i915 = ppgtt->vm.i915;
        unsigned long supported = RUNTIME_INFO(i915)->page_sizes;
        struct drm_i915_gem_object *obj;
        int bit;
        int err;

        /*
         * Sanity check dma misalignment for huge pages -- the dma addresses we
         * insert into the paging structures need to always respect the page
         * size alignment.
         */

        bit = ilog2(I915_GTT_PAGE_SIZE_64K);

        for_each_set_bit_from(bit, &supported,
                              ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) {
                IGT_TIMEOUT(end_time);
                unsigned int page_size = BIT(bit);
                unsigned int flags = PIN_USER | PIN_OFFSET_FIXED;
                unsigned int offset;
                unsigned int size =
                        round_up(page_size, I915_GTT_PAGE_SIZE_2M) << 1;
                struct i915_vma *vma;

                obj = fake_huge_pages_object(i915, size, true);
                if (IS_ERR(obj))
                        return PTR_ERR(obj);

                if (obj->base.size != size) {
                        pr_err("obj->base.size=%zu, expected=%u\n",
                               obj->base.size, size);
                        err = -EINVAL;
                        goto out_put;
                }

                err = i915_gem_object_pin_pages_unlocked(obj);
                if (err)
                        goto out_put;

                /* Force the page size for this object */
                obj->mm.page_sizes.sg = page_size;

                vma = i915_vma_instance(obj, &ppgtt->vm, NULL);
                if (IS_ERR(vma)) {
                        err = PTR_ERR(vma);
                        goto out_unpin;
                }

                err = i915_vma_pin(vma, 0, 0, flags);
                if (err)
                        goto out_unpin;


                err = igt_check_page_sizes(vma);

                if (vma->resource->page_sizes_gtt != page_size) {
                        pr_err("page_sizes.gtt=%u, expected %u\n",
                               vma->resource->page_sizes_gtt, page_size);
                        err = -EINVAL;
                }

                i915_vma_unpin(vma);

                if (err)
                        goto out_unpin;

                /*
                 * Try all the other valid offsets until the next
                 * boundary -- should always fall back to using 4K
                 * pages.
                 */
                for (offset = 4096; offset < page_size; offset += 4096) {
                        err = i915_vma_unbind_unlocked(vma);
                        if (err)
                                goto out_unpin;

                        err = i915_vma_pin(vma, 0, 0, flags | offset);
                        if (err)
                                goto out_unpin;

                        err = igt_check_page_sizes(vma);

                        if (vma->resource->page_sizes_gtt != I915_GTT_PAGE_SIZE_4K) {
                                pr_err("page_sizes.gtt=%u, expected %llu\n",
                                       vma->resource->page_sizes_gtt,
                                       I915_GTT_PAGE_SIZE_4K);
                                err = -EINVAL;
                        }

                        i915_vma_unpin(vma);

                        if (err)
                                goto out_unpin;

                        if (igt_timeout(end_time,
                                        "%s timed out at offset %x with page-size %x\n",
                                        __func__, offset, page_size))
                                break;
                }

                i915_gem_object_lock(obj, NULL);
                i915_gem_object_unpin_pages(obj);
                __i915_gem_object_put_pages(obj);
                i915_gem_object_unlock(obj);
                i915_gem_object_put(obj);
        }

        return 0;

out_unpin:
        i915_gem_object_lock(obj, NULL);
        i915_gem_object_unpin_pages(obj);
        i915_gem_object_unlock(obj);
out_put:
        i915_gem_object_put(obj);

        return err;
}

static void close_object_list(struct list_head *objects)
{
        struct drm_i915_gem_object *obj, *on;

        list_for_each_entry_safe(obj, on, objects, st_link) {
                list_del(&obj->st_link);
                i915_gem_object_lock(obj, NULL);
                i915_gem_object_unpin_pages(obj);
                __i915_gem_object_put_pages(obj);
                i915_gem_object_unlock(obj);
                i915_gem_object_put(obj);
        }
}

static int igt_ppgtt_huge_fill(void *arg)
{
        struct drm_i915_private *i915 = arg;
        unsigned int supported = RUNTIME_INFO(i915)->page_sizes;
        bool has_pte64 = GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55);
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        unsigned long max_pages;
        unsigned long page_num;
        struct file *file;
        bool single = false;
        LIST_HEAD(objects);
        IGT_TIMEOUT(end_time);
        int err = -ENODEV;

        if (supported == I915_GTT_PAGE_SIZE_4K)
                return 0;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }
        vm = i915_gem_context_get_eb_vm(ctx);
        max_pages = vm->total >> PAGE_SHIFT;

        for_each_prime_number_from(page_num, 1, max_pages) {
                struct drm_i915_gem_object *obj;
                u64 size = page_num << PAGE_SHIFT;
                struct i915_vma *vma;
                unsigned int expected_gtt = 0;
                int i;

                obj = fake_huge_pages_object(i915, size, single);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        break;
                }

                if (obj->base.size != size) {
                        pr_err("obj->base.size=%zd, expected=%llu\n",
                               obj->base.size, size);
                        i915_gem_object_put(obj);
                        err = -EINVAL;
                        break;
                }

                err = i915_gem_object_pin_pages_unlocked(obj);
                if (err) {
                        i915_gem_object_put(obj);
                        break;
                }

                list_add(&obj->st_link, &objects);

                vma = i915_vma_instance(obj, vm, NULL);
                if (IS_ERR(vma)) {
                        err = PTR_ERR(vma);
                        break;
                }

                /* vma start must be aligned to BIT(21) to allow 2M PTEs */
                err = i915_vma_pin(vma, 0, BIT(21), PIN_USER);
                if (err)
                        break;

                err = igt_check_page_sizes(vma);
                if (err) {
                        i915_vma_unpin(vma);
                        break;
                }

                /*
                 * Figure out the expected gtt page size knowing that we go from
                 * largest to smallest page size sg chunks, and that we align to
                 * the largest page size.
                 */
                for (i = 0; i < ARRAY_SIZE(page_sizes); ++i) {
                        unsigned int page_size = page_sizes[i];

                        if (HAS_PAGE_SIZES(i915, page_size) &&
                            size >= page_size) {
                                expected_gtt |= page_size;
                                size &= page_size-1;
                        }
                }

                GEM_BUG_ON(!expected_gtt);
                GEM_BUG_ON(size);

                if (!has_pte64 && (obj->base.size < I915_GTT_PAGE_SIZE_2M ||
                                   expected_gtt & I915_GTT_PAGE_SIZE_2M))
                        expected_gtt &= ~I915_GTT_PAGE_SIZE_64K;

                i915_vma_unpin(vma);

                if (!has_pte64 && vma->page_sizes.sg & I915_GTT_PAGE_SIZE_64K) {
                        if (!IS_ALIGNED(vma->node.start,
                                        I915_GTT_PAGE_SIZE_2M)) {
                                pr_err("node.start(%llx) not aligned to 2M\n",
                                       vma->node.start);
                                err = -EINVAL;
                                break;
                        }

                        if (!IS_ALIGNED(vma->node.size,
                                        I915_GTT_PAGE_SIZE_2M)) {
                                pr_err("node.size(%llx) not aligned to 2M\n",
                                       vma->node.size);
                                err = -EINVAL;
                                break;
                        }
                }

                if (vma->resource->page_sizes_gtt != expected_gtt) {
                        pr_err("gtt=%#x, expected=%#x, size=0x%zx, single=%s\n",
                               vma->resource->page_sizes_gtt, expected_gtt,
                               obj->base.size, str_yes_no(!!single));
                        err = -EINVAL;
                        break;
                }

                if (igt_timeout(end_time,
                                "%s timed out at size %zd\n",
                                __func__, obj->base.size))
                        break;

                single = !single;
        }

        close_object_list(&objects);

        if (err == -ENOMEM || err == -ENOSPC)
                err = 0;

        i915_vm_put(vm);
out:
        fput(file);
        return err;
}

static int igt_ppgtt_64K(void *arg)
{
        struct drm_i915_private *i915 = arg;
        bool has_pte64 = GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55);
        struct drm_i915_gem_object *obj;
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        struct file *file;
        const struct object_info {
                unsigned int size;
                unsigned int gtt;
                unsigned int offset;
        } objects[] = {
                /* Cases with forced padding/alignment */
                {
                        .size = SZ_64K,
                        .gtt = I915_GTT_PAGE_SIZE_64K,
                        .offset = 0,
                },
                {
                        .size = SZ_64K + SZ_4K,
                        .gtt = I915_GTT_PAGE_SIZE_4K,
                        .offset = 0,
                },
                {
                        .size = SZ_64K - SZ_4K,
                        .gtt = I915_GTT_PAGE_SIZE_4K,
                        .offset = 0,
                },
                {
                        .size = SZ_2M,
                        .gtt = I915_GTT_PAGE_SIZE_64K,
                        .offset = 0,
                },
                {
                        .size = SZ_2M - SZ_4K,
                        .gtt = I915_GTT_PAGE_SIZE_4K,
                        .offset = 0,
                },
                {
                        .size = SZ_2M + SZ_4K,
                        .gtt = I915_GTT_PAGE_SIZE_64K | I915_GTT_PAGE_SIZE_4K,
                        .offset = 0,
                },
                {
                        .size = SZ_2M + SZ_64K,
                        .gtt = I915_GTT_PAGE_SIZE_64K,
                        .offset = 0,
                },
                {
                        .size = SZ_2M - SZ_64K,
                        .gtt = I915_GTT_PAGE_SIZE_64K,
                        .offset = 0,
                },
                /* Try without any forced padding/alignment */
                {
                        .size = SZ_64K,
                        .offset = SZ_2M,
                        .gtt = I915_GTT_PAGE_SIZE_4K,
                },
                {
                        .size = SZ_128K,
                        .offset = SZ_2M - SZ_64K,
                        .gtt = I915_GTT_PAGE_SIZE_4K,
                },
        };
        struct i915_vma *vma;
        int i, single;
        int err;

        /*
         * Sanity check some of the trickiness with 64K pages -- either we can
         * safely mark the whole page-table(2M block) as 64K, or we have to
         * always fallback to 4K.
         */

        if (!HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_64K))
                return 0;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }
        vm = i915_gem_context_get_eb_vm(ctx);

        for (i = 0; i < ARRAY_SIZE(objects); ++i) {
                unsigned int size = objects[i].size;
                unsigned int expected_gtt = objects[i].gtt;
                unsigned int offset = objects[i].offset;
                unsigned int flags = PIN_USER;

                /*
                 * For modern GTT models, the requirements for marking a page-table
                 * as 64K have been relaxed.  Account for this.
                 */
                if (has_pte64) {
                        expected_gtt = 0;
                        if (size >= SZ_64K)
                                expected_gtt |= I915_GTT_PAGE_SIZE_64K;
                        if (size & (SZ_64K - 1))
                                expected_gtt |= I915_GTT_PAGE_SIZE_4K;
                }

                for (single = 0; single <= 1; single++) {
                        obj = fake_huge_pages_object(i915, size, !!single);
                        if (IS_ERR(obj)) {
                                err = PTR_ERR(obj);
                                goto out_vm;
                        }

                        err = i915_gem_object_pin_pages_unlocked(obj);
                        if (err)
                                goto out_object_put;

                        /*
                         * Disable 2M pages -- We only want to use 64K/4K pages
                         * for this test.
                         */
                        obj->mm.page_sizes.sg &= ~I915_GTT_PAGE_SIZE_2M;

                        vma = i915_vma_instance(obj, vm, NULL);
                        if (IS_ERR(vma)) {
                                err = PTR_ERR(vma);
                                goto out_object_unpin;
                        }

                        if (offset)
                                flags |= PIN_OFFSET_FIXED | offset;

                        err = i915_vma_pin(vma, 0, 0, flags);
                        if (err)
                                goto out_object_unpin;

                        err = igt_check_page_sizes(vma);
                        if (err)
                                goto out_vma_unpin;

                        if (!has_pte64 && !offset &&
                            vma->page_sizes.sg & I915_GTT_PAGE_SIZE_64K) {
                                if (!IS_ALIGNED(vma->node.start,
                                                I915_GTT_PAGE_SIZE_2M)) {
                                        pr_err("node.start(%llx) not aligned to 2M\n",
                                               vma->node.start);
                                        err = -EINVAL;
                                        goto out_vma_unpin;
                                }

                                if (!IS_ALIGNED(vma->node.size,
                                                I915_GTT_PAGE_SIZE_2M)) {
                                        pr_err("node.size(%llx) not aligned to 2M\n",
                                               vma->node.size);
                                        err = -EINVAL;
                                        goto out_vma_unpin;
                                }
                        }

                        if (vma->resource->page_sizes_gtt != expected_gtt) {
                                pr_err("gtt=%#x, expected=%#x, i=%d, single=%s offset=%#x size=%#x\n",
                                       vma->resource->page_sizes_gtt,
                                       expected_gtt, i, str_yes_no(!!single),
                                       offset, size);
                                err = -EINVAL;
                                goto out_vma_unpin;
                        }

                        i915_vma_unpin(vma);
                        i915_gem_object_lock(obj, NULL);
                        i915_gem_object_unpin_pages(obj);
                        __i915_gem_object_put_pages(obj);
                        i915_gem_object_unlock(obj);
                        i915_gem_object_put(obj);

                        i915_gem_drain_freed_objects(i915);
                }
        }

        goto out_vm;

out_vma_unpin:
        i915_vma_unpin(vma);
out_object_unpin:
        i915_gem_object_lock(obj, NULL);
        i915_gem_object_unpin_pages(obj);
        i915_gem_object_unlock(obj);
out_object_put:
        i915_gem_object_put(obj);
out_vm:
        i915_vm_put(vm);
out:
        fput(file);
        return err;
}

static int gpu_write(struct intel_context *ce,
                     struct i915_vma *vma,
                     u32 dw,
                     u32 val)
{
        int err;

        i915_gem_object_lock(vma->obj, NULL);
        err = i915_gem_object_set_to_gtt_domain(vma->obj, true);
        i915_gem_object_unlock(vma->obj);
        if (err)
                return err;

        return igt_gpu_fill_dw(ce, vma, dw * sizeof(u32),
                               vma->size >> PAGE_SHIFT, val);
}

static int
__cpu_check_shmem(struct drm_i915_gem_object *obj, u32 dword, u32 val)
{
        unsigned int needs_flush;
        unsigned long n;
        int err;

        i915_gem_object_lock(obj, NULL);
        err = i915_gem_object_prepare_read(obj, &needs_flush);
        if (err)
                goto err_unlock;

        for (n = 0; n < obj->base.size >> PAGE_SHIFT; ++n) {
                u32 *ptr = kmap_local_page(i915_gem_object_get_page(obj, n));

                if (needs_flush & CLFLUSH_BEFORE)
                        drm_clflush_virt_range(ptr, PAGE_SIZE);

                if (ptr[dword] != val) {
                        pr_err("n=%lu ptr[%u]=%u, val=%u\n",
                               n, dword, ptr[dword], val);
                        kunmap_local(ptr);
                        err = -EINVAL;
                        break;
                }

                kunmap_local(ptr);
        }

        i915_gem_object_finish_access(obj);
err_unlock:
        i915_gem_object_unlock(obj);

        return err;
}

static int __cpu_check_vmap(struct drm_i915_gem_object *obj, u32 dword, u32 val)
{
        unsigned long n = obj->base.size >> PAGE_SHIFT;
        u32 *ptr;
        int err;

        err = i915_gem_object_wait(obj, 0, MAX_SCHEDULE_TIMEOUT);
        if (err)
                return err;

        ptr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WC);
        if (IS_ERR(ptr))
                return PTR_ERR(ptr);

        ptr += dword;
        while (n--) {
                if (*ptr != val) {
                        pr_err("base[%u]=%08x, val=%08x\n",
                               dword, *ptr, val);
                        err = -EINVAL;
                        break;
                }

                ptr += PAGE_SIZE / sizeof(*ptr);
        }

        i915_gem_object_unpin_map(obj);
        return err;
}

static int cpu_check(struct drm_i915_gem_object *obj, u32 dword, u32 val)
{
        if (i915_gem_object_has_struct_page(obj))
                return __cpu_check_shmem(obj, dword, val);
        else
                return __cpu_check_vmap(obj, dword, val);
}

static int __igt_write_huge(struct intel_context *ce,
                            struct drm_i915_gem_object *obj,
                            u64 size, u64 offset,
                            u32 dword, u32 val)
{
        unsigned int flags = PIN_USER | PIN_OFFSET_FIXED;
        struct i915_vma *vma;
        int err;

        vma = i915_vma_instance(obj, ce->vm, NULL);
        if (IS_ERR(vma))
                return PTR_ERR(vma);

        err = i915_vma_pin(vma, size, 0, flags | offset);
        if (err) {
                /*
                 * The ggtt may have some pages reserved so
                 * refrain from erroring out.
                 */
                if (err == -ENOSPC && i915_is_ggtt(ce->vm))
                        err = 0;

                return err;
        }

        err = igt_check_page_sizes(vma);
        if (err)
                goto out_vma_unpin;

        err = gpu_write(ce, vma, dword, val);
        if (err) {
                pr_err("gpu-write failed at offset=%llx\n", offset);
                goto out_vma_unpin;
        }

        err = cpu_check(obj, dword, val);
        if (err) {
                pr_err("cpu-check failed at offset=%llx\n", offset);
                goto out_vma_unpin;
        }

out_vma_unpin:
        i915_vma_unpin(vma);
        return err;
}

static int igt_write_huge(struct drm_i915_private *i915,
                          struct drm_i915_gem_object *obj)
{
        struct i915_gem_engines *engines;
        struct i915_gem_engines_iter it;
        struct intel_context *ce;
        I915_RND_STATE(prng);
        IGT_TIMEOUT(end_time);
        unsigned int max_page_size;
        unsigned int count;
        struct i915_gem_context *ctx;
        struct file *file;
        u64 max;
        u64 num;
        u64 size;
        int *order;
        int i, n;
        int err = 0;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }

        GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));

        size = obj->base.size;
        if (obj->mm.page_sizes.sg & I915_GTT_PAGE_SIZE_64K &&
            !HAS_64K_PAGES(i915))
                size = round_up(size, I915_GTT_PAGE_SIZE_2M);

        n = 0;
        count = 0;
        max = U64_MAX;
        for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
                count++;
                if (!intel_engine_can_store_dword(ce->engine))
                        continue;

                max = min(max, ce->vm->total);
                n++;
        }
        i915_gem_context_unlock_engines(ctx);
        if (!n)
                goto out;

        /*
         * To keep things interesting when alternating between engines in our
         * randomized order, lets also make feeding to the same engine a few
         * times in succession a possibility by enlarging the permutation array.
         */
        order = i915_random_order(count * count, &prng);
        if (!order) {
                err = -ENOMEM;
                goto out;
        }

        max_page_size = rounddown_pow_of_two(obj->mm.page_sizes.sg);
        max = div_u64(max - size, max_page_size);

        /*
         * Try various offsets in an ascending/descending fashion until we
         * timeout -- we want to avoid issues hidden by effectively always using
         * offset = 0.
         */
        i = 0;
        engines = i915_gem_context_lock_engines(ctx);
        for_each_prime_number_from(num, 0, max) {
                u64 offset_low = num * max_page_size;
                u64 offset_high = (max - num) * max_page_size;
                u32 dword = offset_in_page(num) / 4;
                struct intel_context *ce;

                ce = engines->engines[order[i] % engines->num_engines];
                i = (i + 1) % (count * count);
                if (!ce || !intel_engine_can_store_dword(ce->engine))
                        continue;

                /*
                 * In order to utilize 64K pages we need to both pad the vma
                 * size and ensure the vma offset is at the start of the pt
                 * boundary, however to improve coverage we opt for testing both
                 * aligned and unaligned offsets.
                 *
                 * With PS64 this is no longer the case, but to ensure we
                 * sometimes get the compact layout for smaller objects, apply
                 * the round_up anyway.
                 */
                if (obj->mm.page_sizes.sg & I915_GTT_PAGE_SIZE_64K)
                        offset_low = round_down(offset_low,
                                                I915_GTT_PAGE_SIZE_2M);

                err = __igt_write_huge(ce, obj, size, offset_low,
                                       dword, num + 1);
                if (err)
                        break;

                err = __igt_write_huge(ce, obj, size, offset_high,
                                       dword, num + 1);
                if (err)
                        break;

                if (igt_timeout(end_time,
                                "%s timed out on %s, offset_low=%llx offset_high=%llx, max_page_size=%x\n",
                                __func__, ce->engine->name, offset_low, offset_high,
                                max_page_size))
                        break;
        }
        i915_gem_context_unlock_engines(ctx);

        kfree(order);

out:
        fput(file);
        return err;
}

typedef struct drm_i915_gem_object *
(*igt_create_fn)(struct drm_i915_private *i915, u32 size, u32 flags);

static inline bool igt_can_allocate_thp(struct drm_i915_private *i915)
{
        return !!drm_gem_get_huge_mnt(&i915->drm);
}

static struct drm_i915_gem_object *
igt_create_shmem(struct drm_i915_private *i915, u32 size, u32 flags)
{
        if (!igt_can_allocate_thp(i915)) {
                pr_info("%s missing THP support, skipping\n", __func__);
                return ERR_PTR(-ENODEV);
        }

        return i915_gem_object_create_shmem(i915, size);
}

static struct drm_i915_gem_object *
igt_create_internal(struct drm_i915_private *i915, u32 size, u32 flags)
{
        return i915_gem_object_create_internal(i915, size);
}

static struct drm_i915_gem_object *
igt_create_system(struct drm_i915_private *i915, u32 size, u32 flags)
{
        return huge_pages_object(i915, size, size);
}

static struct drm_i915_gem_object *
igt_create_local(struct drm_i915_private *i915, u32 size, u32 flags)
{
        return i915_gem_object_create_lmem(i915, size, flags);
}

static u32 igt_random_size(struct rnd_state *prng,
                           u32 min_page_size,
                           u32 max_page_size)
{
        u64 mask;
        u32 size;

        GEM_BUG_ON(!is_power_of_2(min_page_size));
        GEM_BUG_ON(!is_power_of_2(max_page_size));
        GEM_BUG_ON(min_page_size < PAGE_SIZE);
        GEM_BUG_ON(min_page_size > max_page_size);

        mask = ((max_page_size << 1ULL) - 1) & PAGE_MASK;
        size = prandom_u32_state(prng) & mask;
        if (size < min_page_size)
                size |= min_page_size;

        return size;
}

static int igt_ppgtt_smoke_huge(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj;
        I915_RND_STATE(prng);
        struct {
                igt_create_fn fn;
                u32 min;
                u32 max;
        } backends[] = {
                { igt_create_internal, SZ_64K, SZ_2M,  },
                { igt_create_shmem,    SZ_64K, SZ_32M, },
                { igt_create_local,    SZ_64K, SZ_1G,  },
        };
        int err;
        int i;

        /*
         * Sanity check that the HW uses huge pages correctly through our
         * various backends -- ensure that our writes land in the right place.
         */

        for (i = 0; i < ARRAY_SIZE(backends); ++i) {
                u32 min = backends[i].min;
                u32 max = backends[i].max;
                u32 size = max;

try_again:
                size = igt_random_size(&prng, min, rounddown_pow_of_two(size));

                obj = backends[i].fn(i915, size, 0);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        if (err == -E2BIG) {
                                size >>= 1;
                                goto try_again;
                        } else if (err == -ENODEV) {
                                err = 0;
                                continue;
                        }

                        return err;
                }

                err = i915_gem_object_pin_pages_unlocked(obj);
                if (err) {
                        if (err == -ENXIO || err == -E2BIG || err == -ENOMEM) {
                                i915_gem_object_put(obj);
                                size >>= 1;
                                goto try_again;
                        }
                        goto out_put;
                }

                if (obj->mm.page_sizes.phys < min) {
                        pr_info("%s unable to allocate huge-page(s) with size=%u, i=%d\n",
                                __func__, size, i);
                        err = -ENOMEM;
                        goto out_unpin;
                }

                err = igt_write_huge(i915, obj);
                if (err) {
                        pr_err("%s write-huge failed with size=%u, i=%d\n",
                               __func__, size, i);
                }
out_unpin:
                i915_gem_object_lock(obj, NULL);
                i915_gem_object_unpin_pages(obj);
                __i915_gem_object_put_pages(obj);
                i915_gem_object_unlock(obj);
out_put:
                i915_gem_object_put(obj);

                if (err == -ENOMEM || err == -ENXIO)
                        err = 0;

                if (err)
                        break;

                cond_resched();
        }

        return err;
}

static int igt_ppgtt_sanity_check(void *arg)
{
        struct drm_i915_private *i915 = arg;
        unsigned int supported = RUNTIME_INFO(i915)->page_sizes;
        struct {
                igt_create_fn fn;
                unsigned int flags;
        } backends[] = {
                { igt_create_system, 0,                        },
                { igt_create_local,  0,                        },
                { igt_create_local,  I915_BO_ALLOC_CONTIGUOUS, },
        };
        struct {
                u32 size;
                u32 pages;
        } combos[] = {
                { SZ_64K,               SZ_64K          },
                { SZ_2M,                SZ_2M           },
                { SZ_2M,                SZ_64K          },
                { SZ_2M - SZ_64K,       SZ_64K          },
                { SZ_2M - SZ_4K,        SZ_64K | SZ_4K  },
                { SZ_2M + SZ_4K,        SZ_64K | SZ_4K  },
                { SZ_2M + SZ_4K,        SZ_2M  | SZ_4K  },
                { SZ_2M + SZ_64K,       SZ_2M  | SZ_64K },
                { SZ_2M + SZ_64K,       SZ_64K          },
        };
        int i, j;
        int err;

        if (supported == I915_GTT_PAGE_SIZE_4K)
                return 0;

        /*
         * Sanity check that the HW behaves with a limited set of combinations.
         * We already have a bunch of randomised testing, which should give us
         * a decent amount of variation between runs, however we should keep
         * this to limit the chances of introducing a temporary regression, by
         * testing the most obvious cases that might make something blow up.
         */

        for (i = 0; i < ARRAY_SIZE(backends); ++i) {
                for (j = 0; j < ARRAY_SIZE(combos); ++j) {
                        struct drm_i915_gem_object *obj;
                        u32 size = combos[j].size;
                        u32 pages = combos[j].pages;

                        obj = backends[i].fn(i915, size, backends[i].flags);
                        if (IS_ERR(obj)) {
                                err = PTR_ERR(obj);
                                if (err == -ENODEV) {
                                        pr_info("Device lacks local memory, skipping\n");
                                        err = 0;
                                        break;
                                }

                                return err;
                        }

                        err = i915_gem_object_pin_pages_unlocked(obj);
                        if (err) {
                                i915_gem_object_put(obj);
                                goto out;
                        }

                        GEM_BUG_ON(pages > obj->base.size);
                        pages = pages & supported;

                        if (pages)
                                obj->mm.page_sizes.sg = pages;

                        err = igt_write_huge(i915, obj);

                        i915_gem_object_lock(obj, NULL);
                        i915_gem_object_unpin_pages(obj);
                        __i915_gem_object_put_pages(obj);
                        i915_gem_object_unlock(obj);
                        i915_gem_object_put(obj);

                        if (err) {
                                pr_err("%s write-huge failed with size=%u pages=%u i=%d, j=%d\n",
                                       __func__, size, pages, i, j);
                                goto out;
                        }
                }

                cond_resched();
        }

out:
        if (err == -ENOMEM)
                err = 0;

        return err;
}

static int igt_ppgtt_compact(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj;
        int err;

        /*
         * Simple test to catch issues with compact 64K pages -- since the pt is
         * compacted to 256B that gives us 32 entries per pt, however since the
         * backing page for the pt is 4K, any extra entries we might incorrectly
         * write out should be ignored by the HW. If ever hit such a case this
         * test should catch it since some of our writes would land in scratch.
         */

        if (!HAS_64K_PAGES(i915)) {
                pr_info("device lacks compact 64K page support, skipping\n");
                return 0;
        }

        if (!HAS_LMEM(i915)) {
                pr_info("device lacks LMEM support, skipping\n");
                return 0;
        }

        /* We want the range to cover multiple page-table boundaries. */
        obj = i915_gem_object_create_lmem(i915, SZ_4M, 0);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        err = i915_gem_object_pin_pages_unlocked(obj);
        if (err)
                goto out_put;

        if (obj->mm.page_sizes.phys < I915_GTT_PAGE_SIZE_64K) {
                pr_info("LMEM compact unable to allocate huge-page(s)\n");
                goto out_unpin;
        }

        /*
         * Disable 2M GTT pages by forcing the page-size to 64K for the GTT
         * insertion.
         */
        obj->mm.page_sizes.sg = I915_GTT_PAGE_SIZE_64K;

        err = igt_write_huge(i915, obj);
        if (err)
                pr_err("LMEM compact write-huge failed\n");

out_unpin:
        i915_gem_object_unpin_pages(obj);
out_put:
        i915_gem_object_put(obj);

        if (err == -ENOMEM)
                err = 0;

        return err;
}

static int igt_ppgtt_mixed(void *arg)
{
        struct drm_i915_private *i915 = arg;
        const unsigned long flags = PIN_OFFSET_FIXED | PIN_USER;
        struct drm_i915_gem_object *obj, *on;
        struct i915_gem_engines *engines;
        struct i915_gem_engines_iter it;
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        struct intel_context *ce;
        struct file *file;
        I915_RND_STATE(prng);
        LIST_HEAD(objects);
        struct intel_memory_region *mr;
        struct i915_vma *vma;
        unsigned int count;
        u32 i, addr;
        int *order;
        int n, err;

        /*
         * Sanity check mixing 4K and 64K pages within the same page-table via
         * the new PS64 TLB hint.
         */

        if (!HAS_64K_PAGES(i915)) {
                pr_info("device lacks PS64, skipping\n");
                return 0;
        }

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }
        vm = i915_gem_context_get_eb_vm(ctx);

        i = 0;
        addr = 0;
        do {
                u32 sz;

                sz = i915_prandom_u32_max_state(SZ_4M, &prng);
                sz = max_t(u32, sz, SZ_4K);

                mr = i915->mm.regions[INTEL_REGION_LMEM_0];
                if (i & 1)
                        mr = i915->mm.regions[INTEL_REGION_SMEM];

                obj = i915_gem_object_create_region(mr, sz, 0, 0);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        goto out_vm;
                }

                list_add_tail(&obj->st_link, &objects);

                vma = i915_vma_instance(obj, vm, NULL);
                if (IS_ERR(vma)) {
                        err = PTR_ERR(vma);
                        goto err_put;
                }

                addr = round_up(addr, mr->min_page_size);
                err = i915_vma_pin(vma, 0, 0, addr | flags);
                if (err)
                        goto err_put;

                if (mr->type == INTEL_MEMORY_LOCAL &&
                    (vma->resource->page_sizes_gtt & I915_GTT_PAGE_SIZE_4K)) {
                        err = -EINVAL;
                        goto err_put;
                }

                addr += obj->base.size;
                i++;
        } while (addr <= SZ_16M);

        n = 0;
        count = 0;
        for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
                count++;
                if (!intel_engine_can_store_dword(ce->engine))
                        continue;

                n++;
        }
        i915_gem_context_unlock_engines(ctx);
        if (!n)
                goto err_put;

        order = i915_random_order(count * count, &prng);
        if (!order) {
                err = -ENOMEM;
                goto err_put;
        }

        i = 0;
        addr = 0;
        engines = i915_gem_context_lock_engines(ctx);
        list_for_each_entry(obj, &objects, st_link) {
                u32 rnd = i915_prandom_u32_max_state(UINT_MAX, &prng);

                addr = round_up(addr, obj->mm.region->min_page_size);

                ce = engines->engines[order[i] % engines->num_engines];
                i = (i + 1) % (count * count);
                if (!ce || !intel_engine_can_store_dword(ce->engine))
                        continue;

                err = __igt_write_huge(ce, obj, obj->base.size, addr, 0, rnd);
                if (err)
                        break;

                err = __igt_write_huge(ce, obj, obj->base.size, addr,
                                       offset_in_page(rnd) / sizeof(u32), rnd + 1);
                if (err)
                        break;

                err = __igt_write_huge(ce, obj, obj->base.size, addr,
                                       (PAGE_SIZE / sizeof(u32)) - 1,
                                       rnd + 2);
                if (err)
                        break;

                addr += obj->base.size;

                cond_resched();
        }

        i915_gem_context_unlock_engines(ctx);
        kfree(order);
err_put:
        list_for_each_entry_safe(obj, on, &objects, st_link) {
                list_del(&obj->st_link);
                i915_gem_object_put(obj);
        }
out_vm:
        i915_vm_put(vm);
out:
        fput(file);
        return err;
}

static int igt_tmpfs_fallback(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        struct drm_i915_gem_object *obj;
        struct i915_vma *vma;
        struct file *file;
        u32 *vaddr;
        int err = 0;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }
        vm = i915_gem_context_get_eb_vm(ctx);

        obj = i915_gem_object_create_region(i915->mm.regions[INTEL_REGION_SMEM],
                                            PAGE_SIZE, 0, I915_BO_ALLOC_NOTHP);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto out_restore;
        }

        vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
        if (IS_ERR(vaddr)) {
                err = PTR_ERR(vaddr);
                goto out_put;
        }
        *vaddr = 0xdeadbeaf;

        __i915_gem_object_flush_map(obj, 0, 64);
        i915_gem_object_unpin_map(obj);

        vma = i915_vma_instance(obj, vm, NULL);
        if (IS_ERR(vma)) {
                err = PTR_ERR(vma);
                goto out_put;
        }

        err = i915_vma_pin(vma, 0, 0, PIN_USER);
        if (err)
                goto out_put;

        err = igt_check_page_sizes(vma);

        i915_vma_unpin(vma);
out_put:
        i915_gem_object_put(obj);
out_restore:

        i915_vm_put(vm);
out:
        fput(file);
        return err;
}

static int igt_shrink_thp(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        struct drm_i915_gem_object *obj;
        struct i915_gem_engines_iter it;
        struct intel_context *ce;
        struct i915_vma *vma;
        struct file *file;
        unsigned int flags = PIN_USER;
        unsigned int n;
        intel_wakeref_t wf;
        bool should_swap;
        int err;

        if (!igt_can_allocate_thp(i915)) {
                pr_info("missing THP support, skipping\n");
                return 0;
        }

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        ctx = hugepage_ctx(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out;
        }
        vm = i915_gem_context_get_eb_vm(ctx);

        /*
         * Sanity check shrinking huge-paged object -- make sure nothing blows
         * up.
         */

        obj = i915_gem_object_create_shmem(i915, SZ_2M);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto out_vm;
        }

        vma = i915_vma_instance(obj, vm, NULL);
        if (IS_ERR(vma)) {
                err = PTR_ERR(vma);
                goto out_put;
        }

        wf = intel_runtime_pm_get(&i915->runtime_pm); /* active shrink */

        err = i915_vma_pin(vma, 0, 0, flags);
        if (err)
                goto out_wf;

        if (obj->mm.page_sizes.phys < I915_GTT_PAGE_SIZE_2M) {
                pr_info("failed to allocate THP, finishing test early\n");
                goto out_unpin;
        }

        err = igt_check_page_sizes(vma);
        if (err)
                goto out_unpin;

        n = 0;

        for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
                if (!intel_engine_can_store_dword(ce->engine))
                        continue;

                err = gpu_write(ce, vma, n++, 0xdeadbeaf);
                if (err)
                        break;
        }
        i915_gem_context_unlock_engines(ctx);
        /*
         * Nuke everything *before* we unpin the pages so we can be reasonably
         * sure that when later checking get_nr_swap_pages() that some random
         * leftover object doesn't steal the remaining swap space.
         */
        i915_gem_shrink(NULL, i915, -1UL, NULL,
                        I915_SHRINK_BOUND |
                        I915_SHRINK_UNBOUND |
                        I915_SHRINK_ACTIVE);
        i915_vma_unpin(vma);
        if (err)
                goto out_wf;

        /*
         * Now that the pages are *unpinned* shrinking should invoke
         * shmem to truncate our pages, if we have available swap.
         */
        should_swap = get_nr_swap_pages() > 0;
        i915_gem_shrink(NULL, i915, -1UL, NULL,
                        I915_SHRINK_BOUND |
                        I915_SHRINK_UNBOUND |
                        I915_SHRINK_ACTIVE |
                        I915_SHRINK_WRITEBACK);
        if (should_swap == i915_gem_object_has_pages(obj)) {
                pr_err("unexpected pages mismatch, should_swap=%s\n",
                       str_yes_no(should_swap));
                err = -EINVAL;
                goto out_wf;
        }

        if (should_swap == (obj->mm.page_sizes.sg || obj->mm.page_sizes.phys)) {
                pr_err("unexpected residual page-size bits, should_swap=%s\n",
                       str_yes_no(should_swap));
                err = -EINVAL;
                goto out_wf;
        }

        err = i915_vma_pin(vma, 0, 0, flags);
        if (err)
                goto out_wf;

        while (n--) {
                err = cpu_check(obj, n, 0xdeadbeaf);
                if (err)
                        break;
        }

out_unpin:
        i915_vma_unpin(vma);
out_wf:
        intel_runtime_pm_put(&i915->runtime_pm, wf);
out_put:
        i915_gem_object_put(obj);
out_vm:
        i915_vm_put(vm);
out:
        fput(file);
        return err;
}

int i915_gem_huge_page_mock_selftests(void)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_mock_exhaust_device_supported_pages),
                SUBTEST(igt_mock_memory_region_huge_pages),
                SUBTEST(igt_mock_ppgtt_misaligned_dma),
        };
        struct drm_i915_private *i915;
        struct i915_ppgtt *ppgtt;
        int err;

        i915 = mock_gem_device();
        if (!i915)
                return -ENOMEM;

        /* Pretend to be a device which supports the 48b PPGTT */
        RUNTIME_INFO(i915)->ppgtt_type = INTEL_PPGTT_FULL;
        RUNTIME_INFO(i915)->ppgtt_size = 48;

        ppgtt = i915_ppgtt_create(to_gt(i915), 0);
        if (IS_ERR(ppgtt)) {
                err = PTR_ERR(ppgtt);
                goto out_unlock;
        }

        if (!i915_vm_is_4lvl(&ppgtt->vm)) {
                pr_err("failed to create 48b PPGTT\n");
                err = -EINVAL;
                goto out_put;
        }

        /* If we were ever hit this then it's time to mock the 64K scratch */
        if (!i915_vm_has_scratch_64K(&ppgtt->vm)) {
                pr_err("PPGTT missing 64K scratch page\n");
                err = -EINVAL;
                goto out_put;
        }

        err = i915_subtests(tests, ppgtt);

out_put:
        i915_vm_put(&ppgtt->vm);
out_unlock:
        mock_destroy_device(i915);
        return err;
}

int i915_gem_huge_page_live_selftests(struct drm_i915_private *i915)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_shrink_thp),
                SUBTEST(igt_tmpfs_fallback),
                SUBTEST(igt_ppgtt_smoke_huge),
                SUBTEST(igt_ppgtt_sanity_check),
                SUBTEST(igt_ppgtt_compact),
                SUBTEST(igt_ppgtt_mixed),
                SUBTEST(igt_ppgtt_huge_fill),
                SUBTEST(igt_ppgtt_64K),
        };

        if (!HAS_PPGTT(i915)) {
                pr_info("PPGTT not supported, skipping live-selftests\n");
                return 0;
        }

        if (intel_gt_is_wedged(to_gt(i915)))
                return 0;

        return i915_live_subtests(tests, i915);
}