// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include <linux/prime_numbers.h>
#include <linux/sort.h>

#include <drm/drm_buddy.h>

#include "../i915_selftest.h"

#include "mock_drm.h"
#include "mock_gem_device.h"
#include "mock_region.h"

#include "gem/i915_gem_context.h"
#include "gem/i915_gem_lmem.h"
#include "gem/i915_gem_region.h"
#include "gem/i915_gem_ttm.h"
#include "gem/selftests/igt_gem_utils.h"
#include "gem/selftests/mock_context.h"
#include "gt/intel_engine_pm.h"
#include "gt/intel_engine_user.h"
#include "gt/intel_gt.h"
#include "gt/intel_migrate.h"
#include "i915_memcpy.h"
#include "i915_ttm_buddy_manager.h"
#include "selftests/igt_flush_test.h"
#include "selftests/i915_random.h"

static void close_objects(struct intel_memory_region *mem,
                          struct list_head *objects)
{
        struct drm_i915_private *i915 = mem->i915;
        struct drm_i915_gem_object *obj, *on;

        list_for_each_entry_safe(obj, on, objects, st_link) {
                i915_gem_object_lock(obj, NULL);
                if (i915_gem_object_has_pinned_pages(obj))
                        i915_gem_object_unpin_pages(obj);
                /* No polluting the memory region between tests */
                __i915_gem_object_put_pages(obj);
                i915_gem_object_unlock(obj);
                list_del(&obj->st_link);
                i915_gem_object_put(obj);
        }

        cond_resched();

        i915_gem_drain_freed_objects(i915);
}

static int igt_mock_fill(void *arg)
{
        struct intel_memory_region *mem = arg;
        resource_size_t total = resource_size(&mem->region);
        resource_size_t page_size;
        resource_size_t rem;
        unsigned long max_pages;
        unsigned long page_num;
        LIST_HEAD(objects);
        int err = 0;

        page_size = PAGE_SIZE;
        max_pages = div64_u64(total, page_size);
        rem = total;

        for_each_prime_number_from(page_num, 1, max_pages) {
                resource_size_t size = page_num * page_size;
                struct drm_i915_gem_object *obj;

                obj = i915_gem_object_create_region(mem, size, 0, 0);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        break;
                }

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

                list_add(&obj->st_link, &objects);
                rem -= size;
        }

        if (err == -ENOMEM)
                err = 0;
        if (err == -ENXIO) {
                if (page_num * page_size <= rem) {
                        pr_err("%s failed, space still left in region\n",
                               __func__);
                        err = -EINVAL;
                } else {
                        err = 0;
                }
        }

        close_objects(mem, &objects);

        return err;
}

static struct drm_i915_gem_object *
igt_object_create(struct intel_memory_region *mem,
                  struct list_head *objects,
                  u64 size,
                  unsigned int flags)
{
        struct drm_i915_gem_object *obj;
        int err;

        obj = i915_gem_object_create_region(mem, size, 0, flags);
        if (IS_ERR(obj))
                return obj;

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

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

put:
        i915_gem_object_put(obj);
        return ERR_PTR(err);
}

static void igt_object_release(struct drm_i915_gem_object *obj)
{
        i915_gem_object_lock(obj, NULL);
        i915_gem_object_unpin_pages(obj);
        __i915_gem_object_put_pages(obj);
        i915_gem_object_unlock(obj);
        list_del(&obj->st_link);
        i915_gem_object_put(obj);
}

static bool is_contiguous(struct drm_i915_gem_object *obj)
{
        struct scatterlist *sg;
        dma_addr_t addr = -1;

        for (sg = obj->mm.pages->sgl; sg; sg = sg_next(sg)) {
                if (addr != -1 && sg_dma_address(sg) != addr)
                        return false;

                addr = sg_dma_address(sg) + sg_dma_len(sg);
        }

        return true;
}

static int igt_mock_reserve(void *arg)
{
        struct intel_memory_region *mem = arg;
        struct drm_i915_private *i915 = mem->i915;
        resource_size_t avail = resource_size(&mem->region);
        struct drm_i915_gem_object *obj;
        const u32 chunk_size = SZ_32M;
        u32 i, offset, count, *order;
        u64 allocated, cur_avail;
        I915_RND_STATE(prng);
        LIST_HEAD(objects);
        int err = 0;

        count = avail / chunk_size;
        order = i915_random_order(count, &prng);
        if (!order)
                return 0;

        mem = mock_region_create(i915, 0, SZ_2G, I915_GTT_PAGE_SIZE_4K, 0, 0);
        if (IS_ERR(mem)) {
                pr_err("failed to create memory region\n");
                err = PTR_ERR(mem);
                goto out_free_order;
        }

        /* Reserve a bunch of ranges within the region */
        for (i = 0; i < count; ++i) {
                u64 start = order[i] * chunk_size;
                u64 size = i915_prandom_u32_max_state(chunk_size, &prng);

                /* Allow for some really big holes */
                if (!size)
                        continue;

                size = round_up(size, PAGE_SIZE);
                offset = igt_random_offset(&prng, 0, chunk_size, size,
                                           PAGE_SIZE);

                err = intel_memory_region_reserve(mem, start + offset, size);
                if (err) {
                        pr_err("%s failed to reserve range", __func__);
                        goto out_close;
                }

                /* XXX: maybe sanity check the block range here? */
                avail -= size;
        }

        /* Try to see if we can allocate from the remaining space */
        allocated = 0;
        cur_avail = avail;
        do {
                u32 size = i915_prandom_u32_max_state(cur_avail, &prng);

                size = max_t(u32, round_up(size, PAGE_SIZE), PAGE_SIZE);
                obj = igt_object_create(mem, &objects, size, 0);
                if (IS_ERR(obj)) {
                        if (PTR_ERR(obj) == -ENXIO)
                                break;

                        err = PTR_ERR(obj);
                        goto out_close;
                }
                cur_avail -= size;
                allocated += size;
        } while (1);

        if (allocated != avail) {
                pr_err("%s mismatch between allocation and free space", __func__);
                err = -EINVAL;
        }

out_close:
        close_objects(mem, &objects);
        intel_memory_region_destroy(mem);
out_free_order:
        kfree(order);
        return err;
}

static int igt_mock_contiguous(void *arg)
{
        struct intel_memory_region *mem = arg;
        struct drm_i915_gem_object *obj;
        unsigned long n_objects;
        LIST_HEAD(objects);
        LIST_HEAD(holes);
        I915_RND_STATE(prng);
        resource_size_t total;
        resource_size_t min;
        u64 target;
        int err = 0;

        total = resource_size(&mem->region);

        /* Min size */
        obj = igt_object_create(mem, &objects, PAGE_SIZE,
                                I915_BO_ALLOC_CONTIGUOUS);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        if (!is_contiguous(obj)) {
                pr_err("%s min object spans disjoint sg entries\n", __func__);
                err = -EINVAL;
                goto err_close_objects;
        }

        igt_object_release(obj);

        /* Max size */
        obj = igt_object_create(mem, &objects, total, I915_BO_ALLOC_CONTIGUOUS);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        if (!is_contiguous(obj)) {
                pr_err("%s max object spans disjoint sg entries\n", __func__);
                err = -EINVAL;
                goto err_close_objects;
        }

        igt_object_release(obj);

        /* Internal fragmentation should not bleed into the object size */
        target = i915_prandom_u64_state(&prng);
        div64_u64_rem(target, total, &target);
        target = round_up(target, PAGE_SIZE);
        target = max_t(u64, PAGE_SIZE, target);

        obj = igt_object_create(mem, &objects, target,
                                I915_BO_ALLOC_CONTIGUOUS);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        if (obj->base.size != target) {
                pr_err("%s obj->base.size(%zx) != target(%llx)\n", __func__,
                       obj->base.size, target);
                err = -EINVAL;
                goto err_close_objects;
        }

        if (!is_contiguous(obj)) {
                pr_err("%s object spans disjoint sg entries\n", __func__);
                err = -EINVAL;
                goto err_close_objects;
        }

        igt_object_release(obj);

        /*
         * Try to fragment the address space, such that half of it is free, but
         * the max contiguous block size is SZ_64K.
         */

        target = SZ_64K;
        n_objects = div64_u64(total, target);

        while (n_objects--) {
                struct list_head *list;

                if (n_objects % 2)
                        list = &holes;
                else
                        list = &objects;

                obj = igt_object_create(mem, list, target,
                                        I915_BO_ALLOC_CONTIGUOUS);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        goto err_close_objects;
                }
        }

        close_objects(mem, &holes);

        min = target;
        target = total >> 1;

        /* Make sure we can still allocate all the fragmented space */
        obj = igt_object_create(mem, &objects, target, 0);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto err_close_objects;
        }

        igt_object_release(obj);

        /*
         * Even though we have enough free space, we don't have a big enough
         * contiguous block. Make sure that holds true.
         */

        do {
                bool should_fail = target > min;

                obj = igt_object_create(mem, &objects, target,
                                        I915_BO_ALLOC_CONTIGUOUS);
                if (should_fail != IS_ERR(obj)) {
                        pr_err("%s target allocation(%llx) mismatch\n",
                               __func__, target);
                        err = -EINVAL;
                        goto err_close_objects;
                }

                target >>= 1;
        } while (target >= PAGE_SIZE);

err_close_objects:
        list_splice_tail(&holes, &objects);
        close_objects(mem, &objects);
        return err;
}

static int igt_mock_splintered_region(void *arg)
{
        struct intel_memory_region *mem = arg;
        struct drm_i915_private *i915 = mem->i915;
        struct i915_ttm_buddy_resource *res;
        struct drm_i915_gem_object *obj;
        struct drm_buddy *mm;
        unsigned int expected_order;
        LIST_HEAD(objects);
        u64 size;
        int err = 0;

        /*
         * Sanity check we can still allocate everything even if the
         * mm.max_order != mm.size. i.e our starting address space size is not a
         * power-of-two.
         */

        size = (SZ_4G - 1) & PAGE_MASK;
        mem = mock_region_create(i915, 0, size, PAGE_SIZE, 0, 0);
        if (IS_ERR(mem))
                return PTR_ERR(mem);

        obj = igt_object_create(mem, &objects, size, 0);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto out_close;
        }

        res = to_ttm_buddy_resource(obj->mm.res);
        mm = res->mm;
        if (mm->size != size) {
                pr_err("%s size mismatch(%llu != %llu)\n",
                       __func__, mm->size, size);
                err = -EINVAL;
                goto out_put;
        }

        expected_order = get_order(rounddown_pow_of_two(size));
        if (mm->max_order != expected_order) {
                pr_err("%s order mismatch(%u != %u)\n",
                       __func__, mm->max_order, expected_order);
                err = -EINVAL;
                goto out_put;
        }

        close_objects(mem, &objects);

        obj = igt_object_create(mem, &objects, roundup_pow_of_two(size),
                                I915_BO_ALLOC_CONTIGUOUS);
        if (!IS_ERR(obj)) {
                pr_err("%s too large contiguous allocation was not rejected\n",
                       __func__);
                err = -EINVAL;
                goto out_close;
        }

        obj = igt_object_create(mem, &objects, size, I915_BO_ALLOC_CONTIGUOUS);
        if (IS_ERR(obj)) {
                pr_err("%s largest possible contiguous allocation failed\n",
                       __func__);
                err = PTR_ERR(obj);
                goto out_close;
        }

out_close:
        close_objects(mem, &objects);
out_put:
        intel_memory_region_destroy(mem);
        return err;
}

#ifndef SZ_8G
#define SZ_8G BIT_ULL(33)
#endif

static int igt_mock_max_segment(void *arg)
{
        struct intel_memory_region *mem = arg;
        struct drm_i915_private *i915 = mem->i915;
        struct i915_ttm_buddy_resource *res;
        struct drm_i915_gem_object *obj;
        struct drm_buddy_block *block;
        struct drm_buddy *mm;
        struct list_head *blocks;
        struct scatterlist *sg;
        I915_RND_STATE(prng);
        LIST_HEAD(objects);
        unsigned int max_segment;
        unsigned int ps;
        u64 size;
        int err = 0;

        /*
         * While we may create very large contiguous blocks, we may need
         * to break those down for consumption elsewhere. In particular,
         * dma-mapping with scatterlist elements have an implicit limit of
         * UINT_MAX on each element.
         */

        size = SZ_8G;
        ps = PAGE_SIZE;
        if (i915_prandom_u64_state(&prng) & 1)
                ps = SZ_64K; /* For something like DG2 */

        max_segment = round_down(UINT_MAX, ps);

        mem = mock_region_create(i915, 0, size, ps, 0, 0);
        if (IS_ERR(mem))
                return PTR_ERR(mem);

        obj = igt_object_create(mem, &objects, size, 0);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto out_put;
        }

        res = to_ttm_buddy_resource(obj->mm.res);
        blocks = &res->blocks;
        mm = res->mm;
        size = 0;
        list_for_each_entry(block, blocks, link) {
                if (drm_buddy_block_size(mm, block) > size)
                        size = drm_buddy_block_size(mm, block);
        }
        if (size < max_segment) {
                pr_err("%s: Failed to create a huge contiguous block [> %u], largest block %lld\n",
                       __func__, max_segment, size);
                err = -EINVAL;
                goto out_close;
        }

        for (sg = obj->mm.pages->sgl; sg; sg = sg_next(sg)) {
                dma_addr_t daddr = sg_dma_address(sg);

                if (sg->length > max_segment) {
                        pr_err("%s: Created an oversized scatterlist entry, %u > %u\n",
                               __func__, sg->length, max_segment);
                        err = -EINVAL;
                        goto out_close;
                }

                if (!IS_ALIGNED(daddr, ps)) {
                        pr_err("%s: Created an unaligned scatterlist entry, addr=%pa, ps=%u\n",
                               __func__, &daddr, ps);
                        err = -EINVAL;
                        goto out_close;
                }
        }

out_close:
        close_objects(mem, &objects);
out_put:
        intel_memory_region_destroy(mem);
        return err;
}

static u64 igt_object_mappable_total(struct drm_i915_gem_object *obj)
{
        struct intel_memory_region *mr = obj->mm.region;
        struct i915_ttm_buddy_resource *bman_res =
                to_ttm_buddy_resource(obj->mm.res);
        struct drm_buddy *mm = bman_res->mm;
        struct drm_buddy_block *block;
        u64 total;

        total = 0;
        list_for_each_entry(block, &bman_res->blocks, link) {
                u64 start = drm_buddy_block_offset(block);
                u64 end = start + drm_buddy_block_size(mm, block);

                if (start < resource_size(&mr->io))
                        total += min_t(u64, end, resource_size(&mr->io)) - start;
        }

        return total;
}

static int igt_mock_io_size(void *arg)
{
        struct intel_memory_region *mr = arg;
        struct drm_i915_private *i915 = mr->i915;
        struct drm_i915_gem_object *obj;
        u64 mappable_theft_total;
        u64 io_size;
        u64 total;
        u64 ps;
        u64 rem;
        u64 size;
        I915_RND_STATE(prng);
        LIST_HEAD(objects);
        int err = 0;

        ps = SZ_4K;
        if (i915_prandom_u64_state(&prng) & 1)
                ps = SZ_64K; /* For something like DG2 */

        div64_u64_rem(i915_prandom_u64_state(&prng), SZ_8G, &total);
        total = round_down(total, ps);
        total = max_t(u64, total, SZ_1G);

        div64_u64_rem(i915_prandom_u64_state(&prng), total - ps, &io_size);
        io_size = round_down(io_size, ps);
        io_size = max_t(u64, io_size, SZ_256M); /* 256M seems to be the common lower limit */

        pr_info("%s with ps=%llx, io_size=%llx, total=%llx\n",
                __func__, ps, io_size, total);

        mr = mock_region_create(i915, 0, total, ps, 0, io_size);
        if (IS_ERR(mr)) {
                err = PTR_ERR(mr);
                goto out_err;
        }

        mappable_theft_total = 0;
        rem = total - io_size;
        do {
                div64_u64_rem(i915_prandom_u64_state(&prng), rem, &size);
                size = round_down(size, ps);
                size = max(size, ps);

                obj = igt_object_create(mr, &objects, size,
                                        I915_BO_ALLOC_GPU_ONLY);
                if (IS_ERR(obj)) {
                        pr_err("%s TOPDOWN failed with rem=%llx, size=%llx\n",
                               __func__, rem, size);
                        err = PTR_ERR(obj);
                        goto out_close;
                }

                mappable_theft_total += igt_object_mappable_total(obj);
                rem -= size;
        } while (rem);

        pr_info("%s mappable theft=(%lluMiB/%lluMiB), total=%lluMiB\n",
                __func__,
                (u64)mappable_theft_total >> 20,
                (u64)io_size >> 20,
                (u64)total >> 20);

        /*
         * Even if we allocate all of the non-mappable portion, we should still
         * be able to dip into the mappable portion.
         */
        obj = igt_object_create(mr, &objects, io_size,
                                I915_BO_ALLOC_GPU_ONLY);
        if (IS_ERR(obj)) {
                pr_err("%s allocation unexpectedly failed\n", __func__);
                err = PTR_ERR(obj);
                goto out_close;
        }

        close_objects(mr, &objects);

        rem = io_size;
        do {
                div64_u64_rem(i915_prandom_u64_state(&prng), rem, &size);
                size = round_down(size, ps);
                size = max(size, ps);

                obj = igt_object_create(mr, &objects, size, 0);
                if (IS_ERR(obj)) {
                        pr_err("%s MAPPABLE failed with rem=%llx, size=%llx\n",
                               __func__, rem, size);
                        err = PTR_ERR(obj);
                        goto out_close;
                }

                if (igt_object_mappable_total(obj) != size) {
                        pr_err("%s allocation is not mappable(size=%llx)\n",
                               __func__, size);
                        err = -EINVAL;
                        goto out_close;
                }
                rem -= size;
        } while (rem);

        /*
         * We assume CPU access is required by default, which should result in a
         * failure here, even though the non-mappable portion is free.
         */
        obj = igt_object_create(mr, &objects, ps, 0);
        if (!IS_ERR(obj)) {
                pr_err("%s allocation unexpectedly succeeded\n", __func__);
                err = -EINVAL;
                goto out_close;
        }

out_close:
        close_objects(mr, &objects);
        intel_memory_region_destroy(mr);
out_err:
        if (err == -ENOMEM)
                err = 0;

        return err;
}

static int igt_gpu_write_dw(struct intel_context *ce,
                            struct i915_vma *vma,
                            u32 dword,
                            u32 value)
{
        return igt_gpu_fill_dw(ce, vma, dword * sizeof(u32),
                               vma->size >> PAGE_SHIFT, value);
}

static int igt_cpu_check(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(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 igt_gpu_write(struct i915_gem_context *ctx,
                         struct drm_i915_gem_object *obj)
{
        struct i915_gem_engines *engines;
        struct i915_gem_engines_iter it;
        struct i915_address_space *vm;
        struct intel_context *ce;
        I915_RND_STATE(prng);
        IGT_TIMEOUT(end_time);
        unsigned int count;
        struct i915_vma *vma;
        int *order;
        int i, n;
        int err = 0;

        GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));

        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;

                vm = ce->vm;
                n++;
        }
        i915_gem_context_unlock_engines(ctx);
        if (!n)
                return 0;

        order = i915_random_order(count * count, &prng);
        if (!order)
                return -ENOMEM;

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

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

        i = 0;
        engines = i915_gem_context_lock_engines(ctx);
        do {
                u32 rng = prandom_u32_state(&prng);
                u32 dword = offset_in_page(rng) / 4;

                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_gpu_write_dw(ce, vma, dword, rng);
                if (err)
                        break;

                i915_gem_object_lock(obj, NULL);
                err = igt_cpu_check(obj, dword, rng);
                i915_gem_object_unlock(obj);
                if (err)
                        break;
        } while (!__igt_timeout(end_time, NULL));
        i915_gem_context_unlock_engines(ctx);

out_free:
        kfree(order);

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

        return err;
}

static int igt_lmem_create(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj;
        int err = 0;

        obj = i915_gem_object_create_lmem(i915, PAGE_SIZE, 0);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

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

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

        return err;
}

static int igt_lmem_create_with_ps(void *arg)
{
        struct drm_i915_private *i915 = arg;
        int err = 0;
        u32 ps;

        for (ps = PAGE_SIZE; ps <= SZ_1G; ps <<= 1) {
                struct drm_i915_gem_object *obj;
                dma_addr_t daddr;

                obj = __i915_gem_object_create_lmem_with_ps(i915, ps, ps, 0);
                if (IS_ERR(obj)) {
                        err = PTR_ERR(obj);
                        if (err == -ENXIO || err == -E2BIG) {
                                pr_info("%s not enough lmem for ps(%u) err=%d\n",
                                        __func__, ps, err);
                                err = 0;
                        }

                        break;
                }

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

                i915_gem_object_lock(obj, NULL);
                err = i915_gem_object_pin_pages(obj);
                if (err) {
                        if (err == -ENXIO || err == -E2BIG || err == -ENOMEM) {
                                pr_info("%s not enough lmem for ps(%u) err=%d\n",
                                        __func__, ps, err);
                                err = 0;
                        }
                        goto out_put;
                }

                daddr = i915_gem_object_get_dma_address(obj, 0);
                if (!IS_ALIGNED(daddr, ps)) {
                        pr_err("%s daddr(%pa) not aligned with ps(%u)\n",
                               __func__, &daddr, ps);
                        err = -EINVAL;
                        goto out_unpin;
                }

out_unpin:
                i915_gem_object_unpin_pages(obj);
                __i915_gem_object_put_pages(obj);
out_put:
                i915_gem_object_unlock(obj);
                i915_gem_object_put(obj);

                if (err)
                        break;
        }

        return err;
}

static int igt_lmem_create_cleared_cpu(void *arg)
{
        struct drm_i915_private *i915 = arg;
        I915_RND_STATE(prng);
        IGT_TIMEOUT(end_time);
        u32 size, i;
        int err;

        i915_gem_drain_freed_objects(i915);

        size = max_t(u32, PAGE_SIZE, i915_prandom_u32_max_state(SZ_32M, &prng));
        size = round_up(size, PAGE_SIZE);
        i = 0;

        do {
                struct drm_i915_gem_object *obj;
                unsigned int flags;
                u32 dword, val;
                void *vaddr;

                /*
                 * Alternate between cleared and uncleared allocations, while
                 * also dirtying the pages each time to check that the pages are
                 * always cleared if requested, since we should get some overlap
                 * of the underlying pages, if not all, since we are the only
                 * user.
                 */

                flags = I915_BO_ALLOC_CPU_CLEAR;
                if (i & 1)
                        flags = 0;

                obj = i915_gem_object_create_lmem(i915, size, flags);
                if (IS_ERR(obj))
                        return PTR_ERR(obj);

                i915_gem_object_lock(obj, NULL);
                err = i915_gem_object_pin_pages(obj);
                if (err)
                        goto out_put;

                dword = i915_prandom_u32_max_state(PAGE_SIZE / sizeof(u32),
                                                   &prng);

                if (flags & I915_BO_ALLOC_CPU_CLEAR) {
                        err = igt_cpu_check(obj, dword, 0);
                        if (err) {
                                pr_err("%s failed with size=%u, flags=%u\n",
                                       __func__, size, flags);
                                goto out_unpin;
                        }
                }

                vaddr = i915_gem_object_pin_map(obj, I915_MAP_WC);
                if (IS_ERR(vaddr)) {
                        err = PTR_ERR(vaddr);
                        goto out_unpin;
                }

                val = prandom_u32_state(&prng);

                memset32(vaddr, val, obj->base.size / sizeof(u32));

                i915_gem_object_flush_map(obj);
                i915_gem_object_unpin_map(obj);
out_unpin:
                i915_gem_object_unpin_pages(obj);
                __i915_gem_object_put_pages(obj);
out_put:
                i915_gem_object_unlock(obj);
                i915_gem_object_put(obj);

                if (err)
                        break;
                ++i;
        } while (!__igt_timeout(end_time, NULL));

        pr_info("%s completed (%u) iterations\n", __func__, i);

        return err;
}

static int igt_lmem_write_gpu(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj;
        struct i915_gem_context *ctx;
        struct file *file;
        I915_RND_STATE(prng);
        u32 sz;
        int err;

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

        ctx = live_context(i915, file);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto out_file;
        }

        sz = round_up(prandom_u32_state(&prng) % SZ_32M, PAGE_SIZE);

        obj = i915_gem_object_create_lmem(i915, sz, 0);
        if (IS_ERR(obj)) {
                err = PTR_ERR(obj);
                goto out_file;
        }

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

        err = igt_gpu_write(ctx, obj);
        if (err)
                pr_err("igt_gpu_write failed(%d)\n", err);

        i915_gem_object_unpin_pages(obj);
out_put:
        i915_gem_object_put(obj);
out_file:
        fput(file);
        return err;
}

static struct intel_engine_cs *
random_engine_class(struct drm_i915_private *i915,
                    unsigned int class,
                    struct rnd_state *prng)
{
        struct intel_engine_cs *engine;
        unsigned int count;

        count = 0;
        for (engine = intel_engine_lookup_user(i915, class, 0);
             engine && engine->uabi_class == class;
             engine = rb_entry_safe(rb_next(&engine->uabi_node),
                                    typeof(*engine), uabi_node))
                count++;

        count = i915_prandom_u32_max_state(count, prng);
        return intel_engine_lookup_user(i915, class, count);
}

static int igt_lmem_write_cpu(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj;
        I915_RND_STATE(prng);
        IGT_TIMEOUT(end_time);
        u32 bytes[] = {
                0, /* rng placeholder */
                sizeof(u32),
                sizeof(u64),
                64, /* cl */
                PAGE_SIZE,
                PAGE_SIZE - sizeof(u32),
                PAGE_SIZE - sizeof(u64),
                PAGE_SIZE - 64,
        };
        struct intel_engine_cs *engine;
        struct i915_request *rq;
        u32 *vaddr;
        u32 sz;
        u32 i;
        int *order;
        int count;
        int err;

        engine = random_engine_class(i915, I915_ENGINE_CLASS_COPY, &prng);
        if (!engine)
                return 0;

        pr_info("%s: using %s\n", __func__, engine->name);

        sz = round_up(prandom_u32_state(&prng) % SZ_32M, PAGE_SIZE);
        sz = max_t(u32, 2 * PAGE_SIZE, sz);

        obj = i915_gem_object_create_lmem(i915, sz, I915_BO_ALLOC_CONTIGUOUS);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WC);
        if (IS_ERR(vaddr)) {
                err = PTR_ERR(vaddr);
                goto out_put;
        }

        i915_gem_object_lock(obj, NULL);

        err = dma_resv_reserve_fences(obj->base.resv, 1);
        if (err) {
                i915_gem_object_unlock(obj);
                goto out_put;
        }

        /* Put the pages into a known state -- from the gpu for added fun */
        intel_engine_pm_get(engine);
        err = intel_context_migrate_clear(engine->gt->migrate.context, NULL,
                                          obj->mm.pages->sgl,
                                          i915_gem_get_pat_index(i915,
                                                                 I915_CACHE_NONE),
                                          true, 0xdeadbeaf, &rq);
        if (rq) {
                dma_resv_add_fence(obj->base.resv, &rq->fence,
                                   DMA_RESV_USAGE_WRITE);
                i915_request_put(rq);
        }

        intel_engine_pm_put(engine);
        if (!err)
                err = i915_gem_object_set_to_wc_domain(obj, true);
        i915_gem_object_unlock(obj);
        if (err)
                goto out_unpin;

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

        /* A random multiple of u32, picked between [64, PAGE_SIZE - 64] */
        bytes[0] = igt_random_offset(&prng, 64, PAGE_SIZE - 64, 0, sizeof(u32));
        GEM_BUG_ON(!IS_ALIGNED(bytes[0], sizeof(u32)));

        i = 0;
        do {
                u32 offset;
                u32 align;
                u32 dword;
                u32 size;
                u32 val;

                size = bytes[order[i] % count];
                i = (i + 1) % (count * count);

                align = bytes[order[i] % count];
                i = (i + 1) % (count * count);

                align = max_t(u32, sizeof(u32), rounddown_pow_of_two(align));

                offset = igt_random_offset(&prng, 0, obj->base.size,
                                           size, align);

                val = prandom_u32_state(&prng);
                memset32(vaddr + offset / sizeof(u32), val ^ 0xdeadbeaf,
                         size / sizeof(u32));

                /*
                 * Sample random dw -- don't waste precious time reading every
                 * single dw.
                 */
                dword = igt_random_offset(&prng, offset,
                                          offset + size,
                                          sizeof(u32), sizeof(u32));
                dword /= sizeof(u32);
                if (vaddr[dword] != (val ^ 0xdeadbeaf)) {
                        pr_err("%s vaddr[%u]=%u, val=%u, size=%u, align=%u, offset=%u\n",
                               __func__, dword, vaddr[dword], val ^ 0xdeadbeaf,
                               size, align, offset);
                        err = -EINVAL;
                        break;
                }
        } while (!__igt_timeout(end_time, NULL));

out_unpin:
        i915_gem_object_unpin_map(obj);
out_put:
        i915_gem_object_put(obj);

        return err;
}

static const char *repr_type(u32 type)
{
        switch (type) {
        case I915_MAP_WB:
                return "WB";
        case I915_MAP_WC:
                return "WC";
        }

        return "";
}

static struct drm_i915_gem_object *
create_region_for_mapping(struct intel_memory_region *mr, u64 size, u32 type,
                          void **out_addr)
{
        struct drm_i915_gem_object *obj;
        void *addr;

        obj = i915_gem_object_create_region(mr, size, 0, 0);
        if (IS_ERR(obj)) {
                if (PTR_ERR(obj) == -ENOSPC) /* Stolen memory */
                        return ERR_PTR(-ENODEV);
                return obj;
        }

        addr = i915_gem_object_pin_map_unlocked(obj, type);
        if (IS_ERR(addr)) {
                i915_gem_object_put(obj);
                if (PTR_ERR(addr) == -ENXIO)
                        return ERR_PTR(-ENODEV);
                return addr;
        }

        *out_addr = addr;
        return obj;
}

static int wrap_ktime_compare(const void *A, const void *B)
{
        const ktime_t *a = A, *b = B;

        return ktime_compare(*a, *b);
}

static void igt_memcpy_long(void *dst, const void *src, size_t size)
{
        unsigned long *tmp = dst;
        const unsigned long *s = src;

        size = size / sizeof(unsigned long);
        while (size--)
                *tmp++ = *s++;
}

static inline void igt_memcpy(void *dst, const void *src, size_t size)
{
        memcpy(dst, src, size);
}

static inline void igt_memcpy_from_wc(void *dst, const void *src, size_t size)
{
        i915_memcpy_from_wc(dst, src, size);
}

static int _perf_memcpy(struct intel_memory_region *src_mr,
                        struct intel_memory_region *dst_mr,
                        u64 size, u32 src_type, u32 dst_type)
{
        struct drm_i915_private *i915 = src_mr->i915;
        const struct {
                const char *name;
                void (*copy)(void *dst, const void *src, size_t size);
                bool skip;
        } tests[] = {
                {
                        "memcpy",
                        igt_memcpy,
                },
                {
                        "memcpy_long",
                        igt_memcpy_long,
                },
                {
                        "memcpy_from_wc",
                        igt_memcpy_from_wc,
                        !i915_has_memcpy_from_wc(),
                },
        };
        struct drm_i915_gem_object *src, *dst;
        void *src_addr, *dst_addr;
        int ret = 0;
        int i;

        src = create_region_for_mapping(src_mr, size, src_type, &src_addr);
        if (IS_ERR(src)) {
                ret = PTR_ERR(src);
                goto out;
        }

        dst = create_region_for_mapping(dst_mr, size, dst_type, &dst_addr);
        if (IS_ERR(dst)) {
                ret = PTR_ERR(dst);
                goto out_unpin_src;
        }

        for (i = 0; i < ARRAY_SIZE(tests); ++i) {
                ktime_t t[5];
                int pass;

                if (tests[i].skip)
                        continue;

                for (pass = 0; pass < ARRAY_SIZE(t); pass++) {
                        ktime_t t0, t1;

                        t0 = ktime_get();

                        tests[i].copy(dst_addr, src_addr, size);

                        t1 = ktime_get();
                        t[pass] = ktime_sub(t1, t0);
                }

                sort(t, ARRAY_SIZE(t), sizeof(*t), wrap_ktime_compare, NULL);
                if (t[0] <= 0) {
                        /* ignore the impossible to protect our sanity */
                        pr_debug("Skipping %s src(%s, %s) -> dst(%s, %s) %14s %4lluKiB copy, unstable measurement [%lld, %lld]\n",
                                 __func__,
                                 src_mr->name, repr_type(src_type),
                                 dst_mr->name, repr_type(dst_type),
                                 tests[i].name, size >> 10,
                                 t[0], t[4]);
                        continue;
                }

                pr_info("%s src(%s, %s) -> dst(%s, %s) %14s %4llu KiB copy: %5lld MiB/s\n",
                        __func__,
                        src_mr->name, repr_type(src_type),
                        dst_mr->name, repr_type(dst_type),
                        tests[i].name, size >> 10,
                        div64_u64(mul_u32_u32(4 * size,
                                              1000 * 1000 * 1000),
                                  t[1] + 2 * t[2] + t[3]) >> 20);

                cond_resched();
        }

        i915_gem_object_unpin_map(dst);
        i915_gem_object_put(dst);
out_unpin_src:
        i915_gem_object_unpin_map(src);
        i915_gem_object_put(src);

        i915_gem_drain_freed_objects(i915);
out:
        if (ret == -ENODEV)
                ret = 0;

        return ret;
}

static int perf_memcpy(void *arg)
{
        struct drm_i915_private *i915 = arg;
        static const u32 types[] = {
                I915_MAP_WB,
                I915_MAP_WC,
        };
        static const u32 sizes[] = {
                SZ_4K,
                SZ_64K,
                SZ_4M,
        };
        struct intel_memory_region *src_mr, *dst_mr;
        int src_id, dst_id;
        int i, j, k;
        int ret;

        for_each_memory_region(src_mr, i915, src_id) {
                for_each_memory_region(dst_mr, i915, dst_id) {
                        for (i = 0; i < ARRAY_SIZE(sizes); ++i) {
                                for (j = 0; j < ARRAY_SIZE(types); ++j) {
                                        for (k = 0; k < ARRAY_SIZE(types); ++k) {
                                                ret = _perf_memcpy(src_mr,
                                                                   dst_mr,
                                                                   sizes[i],
                                                                   types[j],
                                                                   types[k]);
                                                if (ret)
                                                        return ret;
                                        }
                                }
                        }
                }
        }

        return 0;
}

int intel_memory_region_mock_selftests(void)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_mock_reserve),
                SUBTEST(igt_mock_fill),
                SUBTEST(igt_mock_contiguous),
                SUBTEST(igt_mock_splintered_region),
                SUBTEST(igt_mock_max_segment),
                SUBTEST(igt_mock_io_size),
        };
        struct intel_memory_region *mem;
        struct drm_i915_private *i915;
        int err;

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

        mem = mock_region_create(i915, 0, SZ_2G, I915_GTT_PAGE_SIZE_4K, 0, 0);
        if (IS_ERR(mem)) {
                pr_err("failed to create memory region\n");
                err = PTR_ERR(mem);
                goto out_unref;
        }

        err = i915_subtests(tests, mem);

        intel_memory_region_destroy(mem);
out_unref:
        mock_destroy_device(i915);
        return err;
}

int intel_memory_region_live_selftests(struct drm_i915_private *i915)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_lmem_create),
                SUBTEST(igt_lmem_create_with_ps),
                SUBTEST(igt_lmem_create_cleared_cpu),
                SUBTEST(igt_lmem_write_cpu),
                SUBTEST(igt_lmem_write_gpu),
        };

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

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

        return i915_live_subtests(tests, i915);
}

int intel_memory_region_perf_selftests(struct drm_i915_private *i915)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(perf_memcpy),
        };

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

        return i915_live_subtests(tests, i915);
}