--- /dev/null
- struct scatterlist *sg;
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include <drm/ttm/ttm_bo_driver.h>
+#include <drm/ttm/ttm_placement.h>
+
+#include "i915_drv.h"
+#include "intel_memory_region.h"
+#include "intel_region_ttm.h"
+
+#include "gem/i915_gem_object.h"
+#include "gem/i915_gem_region.h"
+#include "gem/i915_gem_ttm.h"
+#include "gem/i915_gem_mman.h"
+
+#include "gt/intel_migrate.h"
+#include "gt/intel_engine_pm.h"
+
+#define I915_PL_LMEM0 TTM_PL_PRIV
+#define I915_PL_SYSTEM TTM_PL_SYSTEM
+#define I915_PL_STOLEN TTM_PL_VRAM
+#define I915_PL_GGTT TTM_PL_TT
+
+#define I915_TTM_PRIO_PURGE 0
+#define I915_TTM_PRIO_NO_PAGES 1
+#define I915_TTM_PRIO_HAS_PAGES 2
+
+/*
+ * Size of struct ttm_place vector in on-stack struct ttm_placement allocs
+ */
+#define I915_TTM_MAX_PLACEMENTS INTEL_REGION_UNKNOWN
+
+/**
+ * struct i915_ttm_tt - TTM page vector with additional private information
+ * @ttm: The base TTM page vector.
+ * @dev: The struct device used for dma mapping and unmapping.
+ * @cached_st: The cached scatter-gather table.
+ *
+ * Note that DMA may be going on right up to the point where the page-
+ * vector is unpopulated in delayed destroy. Hence keep the
+ * scatter-gather table mapped and cached up to that point. This is
+ * different from the cached gem object io scatter-gather table which
+ * doesn't have an associated dma mapping.
+ */
+struct i915_ttm_tt {
+ struct ttm_tt ttm;
+ struct device *dev;
+ struct sg_table *cached_st;
+};
+
+static const struct ttm_place sys_placement_flags = {
+ .fpfn = 0,
+ .lpfn = 0,
+ .mem_type = I915_PL_SYSTEM,
+ .flags = 0,
+};
+
+static struct ttm_placement i915_sys_placement = {
+ .num_placement = 1,
+ .placement = &sys_placement_flags,
+ .num_busy_placement = 1,
+ .busy_placement = &sys_placement_flags,
+};
+
+static int i915_ttm_err_to_gem(int err)
+{
+ /* Fastpath */
+ if (likely(!err))
+ return 0;
+
+ switch (err) {
+ case -EBUSY:
+ /*
+ * TTM likes to convert -EDEADLK to -EBUSY, and wants us to
+ * restart the operation, since we don't record the contending
+ * lock. We use -EAGAIN to restart.
+ */
+ return -EAGAIN;
+ case -ENOSPC:
+ /*
+ * Memory type / region is full, and we can't evict.
+ * Except possibly system, that returns -ENOMEM;
+ */
+ return -ENXIO;
+ default:
+ break;
+ }
+
+ return err;
+}
+
+static bool gpu_binds_iomem(struct ttm_resource *mem)
+{
+ return mem->mem_type != TTM_PL_SYSTEM;
+}
+
+static bool cpu_maps_iomem(struct ttm_resource *mem)
+{
+ /* Once / if we support GGTT, this is also false for cached ttm_tts */
+ return mem->mem_type != TTM_PL_SYSTEM;
+}
+
+static enum i915_cache_level
+i915_ttm_cache_level(struct drm_i915_private *i915, struct ttm_resource *res,
+ struct ttm_tt *ttm)
+{
+ return ((HAS_LLC(i915) || HAS_SNOOP(i915)) && !gpu_binds_iomem(res) &&
+ ttm->caching == ttm_cached) ? I915_CACHE_LLC :
+ I915_CACHE_NONE;
+}
+
+static void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj);
+
+static enum ttm_caching
+i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj)
+{
+ /*
+ * Objects only allowed in system get cached cpu-mappings.
+ * Other objects get WC mapping for now. Even if in system.
+ */
+ if (obj->mm.region->type == INTEL_MEMORY_SYSTEM &&
+ obj->mm.n_placements <= 1)
+ return ttm_cached;
+
+ return ttm_write_combined;
+}
+
+static void
+i915_ttm_place_from_region(const struct intel_memory_region *mr,
+ struct ttm_place *place,
+ unsigned int flags)
+{
+ memset(place, 0, sizeof(*place));
+ place->mem_type = intel_region_to_ttm_type(mr);
+
+ if (flags & I915_BO_ALLOC_CONTIGUOUS)
+ place->flags = TTM_PL_FLAG_CONTIGUOUS;
+}
+
+static void
+i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
+ struct ttm_place *requested,
+ struct ttm_place *busy,
+ struct ttm_placement *placement)
+{
+ unsigned int num_allowed = obj->mm.n_placements;
+ unsigned int flags = obj->flags;
+ unsigned int i;
+
+ placement->num_placement = 1;
+ i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] :
+ obj->mm.region, requested, flags);
+
+ /* Cache this on object? */
+ placement->num_busy_placement = num_allowed;
+ for (i = 0; i < placement->num_busy_placement; ++i)
+ i915_ttm_place_from_region(obj->mm.placements[i], busy + i, flags);
+
+ if (num_allowed == 0) {
+ *busy = *requested;
+ placement->num_busy_placement = 1;
+ }
+
+ placement->placement = requested;
+ placement->busy_placement = busy;
+}
+
+static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
+ uint32_t page_flags)
+{
+ struct ttm_resource_manager *man =
+ ttm_manager_type(bo->bdev, bo->resource->mem_type);
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ struct i915_ttm_tt *i915_tt;
+ int ret;
+
+ i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL);
+ if (!i915_tt)
+ return NULL;
+
+ if (obj->flags & I915_BO_ALLOC_CPU_CLEAR &&
+ man->use_tt)
+ page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
+
+ ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags,
+ i915_ttm_select_tt_caching(obj));
+ if (ret) {
+ kfree(i915_tt);
+ return NULL;
+ }
+
+ i915_tt->dev = obj->base.dev->dev;
+
+ return &i915_tt->ttm;
+}
+
+static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
+{
+ struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
+
+ if (i915_tt->cached_st) {
+ dma_unmap_sgtable(i915_tt->dev, i915_tt->cached_st,
+ DMA_BIDIRECTIONAL, 0);
+ sg_free_table(i915_tt->cached_st);
+ kfree(i915_tt->cached_st);
+ i915_tt->cached_st = NULL;
+ }
+ ttm_pool_free(&bdev->pool, ttm);
+}
+
+static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
+{
+ struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
+
+ ttm_tt_destroy_common(bdev, ttm);
+ ttm_tt_fini(ttm);
+ kfree(i915_tt);
+}
+
+static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo,
+ const struct ttm_place *place)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+
+ /* Will do for now. Our pinned objects are still on TTM's LRU lists */
+ return i915_gem_object_evictable(obj);
+}
+
+static void i915_ttm_evict_flags(struct ttm_buffer_object *bo,
+ struct ttm_placement *placement)
+{
+ *placement = i915_sys_placement;
+}
+
+static int i915_ttm_move_notify(struct ttm_buffer_object *bo)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ int ret;
+
+ ret = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
+ if (ret)
+ return ret;
+
+ ret = __i915_gem_object_put_pages(obj);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void i915_ttm_free_cached_io_st(struct drm_i915_gem_object *obj)
+{
+ struct radix_tree_iter iter;
+ void __rcu **slot;
+
+ if (!obj->ttm.cached_io_st)
+ return;
+
+ rcu_read_lock();
+ radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0)
+ radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index);
+ rcu_read_unlock();
+
+ sg_free_table(obj->ttm.cached_io_st);
+ kfree(obj->ttm.cached_io_st);
+ obj->ttm.cached_io_st = NULL;
+}
+
+static void
+i915_ttm_adjust_domains_after_move(struct drm_i915_gem_object *obj)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+
+ if (cpu_maps_iomem(bo->resource) || bo->ttm->caching != ttm_cached) {
+ obj->write_domain = I915_GEM_DOMAIN_WC;
+ obj->read_domains = I915_GEM_DOMAIN_WC;
+ } else {
+ obj->write_domain = I915_GEM_DOMAIN_CPU;
+ obj->read_domains = I915_GEM_DOMAIN_CPU;
+ }
+}
+
+static void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+ unsigned int cache_level;
+ unsigned int i;
+
+ /*
+ * If object was moved to an allowable region, update the object
+ * region to consider it migrated. Note that if it's currently not
+ * in an allowable region, it's evicted and we don't update the
+ * object region.
+ */
+ if (intel_region_to_ttm_type(obj->mm.region) != bo->resource->mem_type) {
+ for (i = 0; i < obj->mm.n_placements; ++i) {
+ struct intel_memory_region *mr = obj->mm.placements[i];
+
+ if (intel_region_to_ttm_type(mr) == bo->resource->mem_type &&
+ mr != obj->mm.region) {
+ i915_gem_object_release_memory_region(obj);
+ i915_gem_object_init_memory_region(obj, mr);
+ break;
+ }
+ }
+ }
+
+ obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM);
+
+ obj->mem_flags |= cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :
+ I915_BO_FLAG_STRUCT_PAGE;
+
+ cache_level = i915_ttm_cache_level(to_i915(bo->base.dev), bo->resource,
+ bo->ttm);
+ i915_gem_object_set_cache_coherency(obj, cache_level);
+}
+
+static void i915_ttm_purge(struct drm_i915_gem_object *obj)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+ struct ttm_operation_ctx ctx = {
+ .interruptible = true,
+ .no_wait_gpu = false,
+ };
+ struct ttm_placement place = {};
+ int ret;
+
+ if (obj->mm.madv == __I915_MADV_PURGED)
+ return;
+
+ /* TTM's purge interface. Note that we might be reentering. */
+ ret = ttm_bo_validate(bo, &place, &ctx);
+ if (!ret) {
+ obj->write_domain = 0;
+ obj->read_domains = 0;
+ i915_ttm_adjust_gem_after_move(obj);
+ i915_ttm_free_cached_io_st(obj);
+ obj->mm.madv = __I915_MADV_PURGED;
+ }
+}
+
+static void i915_ttm_swap_notify(struct ttm_buffer_object *bo)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ int ret = i915_ttm_move_notify(bo);
+
+ GEM_WARN_ON(ret);
+ GEM_WARN_ON(obj->ttm.cached_io_st);
+ if (!ret && obj->mm.madv != I915_MADV_WILLNEED)
+ i915_ttm_purge(obj);
+}
+
+static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+
+ if (likely(obj)) {
+ /* This releases all gem object bindings to the backend. */
+ i915_ttm_free_cached_io_st(obj);
+ __i915_gem_free_object(obj);
+ }
+}
+
+static struct intel_memory_region *
+i915_ttm_region(struct ttm_device *bdev, int ttm_mem_type)
+{
+ struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);
+
+ /* There's some room for optimization here... */
+ GEM_BUG_ON(ttm_mem_type != I915_PL_SYSTEM &&
+ ttm_mem_type < I915_PL_LMEM0);
+ if (ttm_mem_type == I915_PL_SYSTEM)
+ return intel_memory_region_lookup(i915, INTEL_MEMORY_SYSTEM,
+ 0);
+
+ return intel_memory_region_lookup(i915, INTEL_MEMORY_LOCAL,
+ ttm_mem_type - I915_PL_LMEM0);
+}
+
+static struct sg_table *i915_ttm_tt_get_st(struct ttm_tt *ttm)
+{
+ struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
- sg = __sg_alloc_table_from_pages
- (st, ttm->pages, ttm->num_pages, 0,
- (unsigned long)ttm->num_pages << PAGE_SHIFT,
- i915_sg_segment_size(), NULL, 0, GFP_KERNEL);
- if (IS_ERR(sg)) {
+ struct sg_table *st;
+ int ret;
+
+ if (i915_tt->cached_st)
+ return i915_tt->cached_st;
+
+ st = kzalloc(sizeof(*st), GFP_KERNEL);
+ if (!st)
+ return ERR_PTR(-ENOMEM);
+
- return ERR_CAST(sg);
++ ret = sg_alloc_table_from_pages_segment(st,
++ ttm->pages, ttm->num_pages,
++ 0, (unsigned long)ttm->num_pages << PAGE_SHIFT,
++ i915_sg_segment_size(), GFP_KERNEL);
++ if (ret) {
+ kfree(st);
++ return ERR_PTR(ret);
+ }
+
+ ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
+ if (ret) {
+ sg_free_table(st);
+ kfree(st);
+ return ERR_PTR(ret);
+ }
+
+ i915_tt->cached_st = st;
+ return st;
+}
+
+static struct sg_table *
+i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
+ struct ttm_resource *res)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+
+ if (!gpu_binds_iomem(res))
+ return i915_ttm_tt_get_st(bo->ttm);
+
+ /*
+ * If CPU mapping differs, we need to add the ttm_tt pages to
+ * the resulting st. Might make sense for GGTT.
+ */
+ GEM_WARN_ON(!cpu_maps_iomem(res));
+ return intel_region_ttm_resource_to_st(obj->mm.region, res);
+}
+
+static int i915_ttm_accel_move(struct ttm_buffer_object *bo,
+ struct ttm_resource *dst_mem,
+ struct sg_table *dst_st)
+{
+ struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915),
+ bdev);
+ struct ttm_resource_manager *src_man =
+ ttm_manager_type(bo->bdev, bo->resource->mem_type);
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ struct sg_table *src_st;
+ struct i915_request *rq;
+ struct ttm_tt *ttm = bo->ttm;
+ enum i915_cache_level src_level, dst_level;
+ int ret;
+
+ if (!i915->gt.migrate.context)
+ return -EINVAL;
+
+ dst_level = i915_ttm_cache_level(i915, dst_mem, ttm);
+ if (!ttm || !ttm_tt_is_populated(ttm)) {
+ if (bo->type == ttm_bo_type_kernel)
+ return -EINVAL;
+
+ if (ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC))
+ return 0;
+
+ intel_engine_pm_get(i915->gt.migrate.context->engine);
+ ret = intel_context_migrate_clear(i915->gt.migrate.context, NULL,
+ dst_st->sgl, dst_level,
+ gpu_binds_iomem(dst_mem),
+ 0, &rq);
+
+ if (!ret && rq) {
+ i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT);
+ i915_request_put(rq);
+ }
+ intel_engine_pm_put(i915->gt.migrate.context->engine);
+ } else {
+ src_st = src_man->use_tt ? i915_ttm_tt_get_st(ttm) :
+ obj->ttm.cached_io_st;
+
+ src_level = i915_ttm_cache_level(i915, bo->resource, ttm);
+ intel_engine_pm_get(i915->gt.migrate.context->engine);
+ ret = intel_context_migrate_copy(i915->gt.migrate.context,
+ NULL, src_st->sgl, src_level,
+ gpu_binds_iomem(bo->resource),
+ dst_st->sgl, dst_level,
+ gpu_binds_iomem(dst_mem),
+ &rq);
+ if (!ret && rq) {
+ i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT);
+ i915_request_put(rq);
+ }
+ intel_engine_pm_put(i915->gt.migrate.context->engine);
+ }
+
+ return ret;
+}
+
+static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,
+ struct ttm_operation_ctx *ctx,
+ struct ttm_resource *dst_mem,
+ struct ttm_place *hop)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ struct ttm_resource_manager *dst_man =
+ ttm_manager_type(bo->bdev, dst_mem->mem_type);
+ struct intel_memory_region *dst_reg, *src_reg;
+ union {
+ struct ttm_kmap_iter_tt tt;
+ struct ttm_kmap_iter_iomap io;
+ } _dst_iter, _src_iter;
+ struct ttm_kmap_iter *dst_iter, *src_iter;
+ struct sg_table *dst_st;
+ int ret;
+
+ dst_reg = i915_ttm_region(bo->bdev, dst_mem->mem_type);
+ src_reg = i915_ttm_region(bo->bdev, bo->resource->mem_type);
+ GEM_BUG_ON(!dst_reg || !src_reg);
+
+ /* Sync for now. We could do the actual copy async. */
+ ret = ttm_bo_wait_ctx(bo, ctx);
+ if (ret)
+ return ret;
+
+ ret = i915_ttm_move_notify(bo);
+ if (ret)
+ return ret;
+
+ if (obj->mm.madv != I915_MADV_WILLNEED) {
+ i915_ttm_purge(obj);
+ ttm_resource_free(bo, &dst_mem);
+ return 0;
+ }
+
+ /* Populate ttm with pages if needed. Typically system memory. */
+ if (bo->ttm && (dst_man->use_tt ||
+ (bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED))) {
+ ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx);
+ if (ret)
+ return ret;
+ }
+
+ dst_st = i915_ttm_resource_get_st(obj, dst_mem);
+ if (IS_ERR(dst_st))
+ return PTR_ERR(dst_st);
+
+ ret = i915_ttm_accel_move(bo, dst_mem, dst_st);
+ if (ret) {
+ /* If we start mapping GGTT, we can no longer use man::use_tt here. */
+ dst_iter = !cpu_maps_iomem(dst_mem) ?
+ ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm) :
+ ttm_kmap_iter_iomap_init(&_dst_iter.io, &dst_reg->iomap,
+ dst_st, dst_reg->region.start);
+
+ src_iter = !cpu_maps_iomem(bo->resource) ?
+ ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm) :
+ ttm_kmap_iter_iomap_init(&_src_iter.io, &src_reg->iomap,
+ obj->ttm.cached_io_st,
+ src_reg->region.start);
+
+ ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
+ }
+ /* Below dst_mem becomes bo->resource. */
+ ttm_bo_move_sync_cleanup(bo, dst_mem);
+ i915_ttm_adjust_domains_after_move(obj);
+ i915_ttm_free_cached_io_st(obj);
+
+ if (gpu_binds_iomem(dst_mem) || cpu_maps_iomem(dst_mem)) {
+ obj->ttm.cached_io_st = dst_st;
+ obj->ttm.get_io_page.sg_pos = dst_st->sgl;
+ obj->ttm.get_io_page.sg_idx = 0;
+ }
+
+ i915_ttm_adjust_gem_after_move(obj);
+ return 0;
+}
+
+static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem)
+{
+ if (!cpu_maps_iomem(mem))
+ return 0;
+
+ mem->bus.caching = ttm_write_combined;
+ mem->bus.is_iomem = true;
+
+ return 0;
+}
+
+static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
+ unsigned long page_offset)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+ unsigned long base = obj->mm.region->iomap.base - obj->mm.region->region.start;
+ struct scatterlist *sg;
+ unsigned int ofs;
+
+ GEM_WARN_ON(bo->ttm);
+
+ sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true);
+
+ return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs;
+}
+
+static struct ttm_device_funcs i915_ttm_bo_driver = {
+ .ttm_tt_create = i915_ttm_tt_create,
+ .ttm_tt_unpopulate = i915_ttm_tt_unpopulate,
+ .ttm_tt_destroy = i915_ttm_tt_destroy,
+ .eviction_valuable = i915_ttm_eviction_valuable,
+ .evict_flags = i915_ttm_evict_flags,
+ .move = i915_ttm_move,
+ .swap_notify = i915_ttm_swap_notify,
+ .delete_mem_notify = i915_ttm_delete_mem_notify,
+ .io_mem_reserve = i915_ttm_io_mem_reserve,
+ .io_mem_pfn = i915_ttm_io_mem_pfn,
+};
+
+/**
+ * i915_ttm_driver - Return a pointer to the TTM device funcs
+ *
+ * Return: Pointer to statically allocated TTM device funcs.
+ */
+struct ttm_device_funcs *i915_ttm_driver(void)
+{
+ return &i915_ttm_bo_driver;
+}
+
+static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
+ struct ttm_placement *placement)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+ struct ttm_operation_ctx ctx = {
+ .interruptible = true,
+ .no_wait_gpu = false,
+ };
+ struct sg_table *st;
+ int real_num_busy;
+ int ret;
+
+ /* First try only the requested placement. No eviction. */
+ real_num_busy = fetch_and_zero(&placement->num_busy_placement);
+ ret = ttm_bo_validate(bo, placement, &ctx);
+ if (ret) {
+ ret = i915_ttm_err_to_gem(ret);
+ /*
+ * Anything that wants to restart the operation gets to
+ * do that.
+ */
+ if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS ||
+ ret == -EAGAIN)
+ return ret;
+
+ /*
+ * If the initial attempt fails, allow all accepted placements,
+ * evicting if necessary.
+ */
+ placement->num_busy_placement = real_num_busy;
+ ret = ttm_bo_validate(bo, placement, &ctx);
+ if (ret)
+ return i915_ttm_err_to_gem(ret);
+ }
+
+ i915_ttm_adjust_lru(obj);
+ if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) {
+ ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx);
+ if (ret)
+ return ret;
+
+ i915_ttm_adjust_domains_after_move(obj);
+ i915_ttm_adjust_gem_after_move(obj);
+ }
+
+ if (!i915_gem_object_has_pages(obj)) {
+ /* Object either has a page vector or is an iomem object */
+ st = bo->ttm ? i915_ttm_tt_get_st(bo->ttm) : obj->ttm.cached_io_st;
+ if (IS_ERR(st))
+ return PTR_ERR(st);
+
+ __i915_gem_object_set_pages(obj, st, i915_sg_dma_sizes(st->sgl));
+ }
+
+ return ret;
+}
+
+static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
+{
+ struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS];
+ struct ttm_placement placement;
+
+ GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS);
+
+ /* Move to the requested placement. */
+ i915_ttm_placement_from_obj(obj, &requested, busy, &placement);
+
+ return __i915_ttm_get_pages(obj, &placement);
+}
+
+/**
+ * DOC: Migration vs eviction
+ *
+ * GEM migration may not be the same as TTM migration / eviction. If
+ * the TTM core decides to evict an object it may be evicted to a
+ * TTM memory type that is not in the object's allowable GEM regions, or
+ * in fact theoretically to a TTM memory type that doesn't correspond to
+ * a GEM memory region. In that case the object's GEM region is not
+ * updated, and the data is migrated back to the GEM region at
+ * get_pages time. TTM may however set up CPU ptes to the object even
+ * when it is evicted.
+ * Gem forced migration using the i915_ttm_migrate() op, is allowed even
+ * to regions that are not in the object's list of allowable placements.
+ */
+static int i915_ttm_migrate(struct drm_i915_gem_object *obj,
+ struct intel_memory_region *mr)
+{
+ struct ttm_place requested;
+ struct ttm_placement placement;
+ int ret;
+
+ i915_ttm_place_from_region(mr, &requested, obj->flags);
+ placement.num_placement = 1;
+ placement.num_busy_placement = 1;
+ placement.placement = &requested;
+ placement.busy_placement = &requested;
+
+ ret = __i915_ttm_get_pages(obj, &placement);
+ if (ret)
+ return ret;
+
+ /*
+ * Reinitialize the region bindings. This is primarily
+ * required for objects where the new region is not in
+ * its allowable placements.
+ */
+ if (obj->mm.region != mr) {
+ i915_gem_object_release_memory_region(obj);
+ i915_gem_object_init_memory_region(obj, mr);
+ }
+
+ return 0;
+}
+
+static void i915_ttm_put_pages(struct drm_i915_gem_object *obj,
+ struct sg_table *st)
+{
+ /*
+ * We're currently not called from a shrinker, so put_pages()
+ * typically means the object is about to destroyed, or called
+ * from move_notify(). So just avoid doing much for now.
+ * If the object is not destroyed next, The TTM eviction logic
+ * and shrinkers will move it out if needed.
+ */
+
+ i915_ttm_adjust_lru(obj);
+}
+
+static void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj)
+{
+ struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
+
+ /*
+ * Don't manipulate the TTM LRUs while in TTM bo destruction.
+ * We're called through i915_ttm_delete_mem_notify().
+ */
+ if (!kref_read(&bo->kref))
+ return;
+
+ /*
+ * Put on the correct LRU list depending on the MADV status
+ */
+ spin_lock(&bo->bdev->lru_lock);
+ if (obj->mm.madv != I915_MADV_WILLNEED) {
+ bo->priority = I915_TTM_PRIO_PURGE;
+ } else if (!i915_gem_object_has_pages(obj)) {
+ if (bo->priority < I915_TTM_PRIO_HAS_PAGES)
+ bo->priority = I915_TTM_PRIO_HAS_PAGES;
+ } else {
+ if (bo->priority > I915_TTM_PRIO_NO_PAGES)
+ bo->priority = I915_TTM_PRIO_NO_PAGES;
+ }
+
+ ttm_bo_move_to_lru_tail(bo, bo->resource, NULL);
+ spin_unlock(&bo->bdev->lru_lock);
+}
+
+/*
+ * TTM-backed gem object destruction requires some clarification.
+ * Basically we have two possibilities here. We can either rely on the
+ * i915 delayed destruction and put the TTM object when the object
+ * is idle. This would be detected by TTM which would bypass the
+ * TTM delayed destroy handling. The other approach is to put the TTM
+ * object early and rely on the TTM destroyed handling, and then free
+ * the leftover parts of the GEM object once TTM's destroyed list handling is
+ * complete. For now, we rely on the latter for two reasons:
+ * a) TTM can evict an object even when it's on the delayed destroy list,
+ * which in theory allows for complete eviction.
+ * b) There is work going on in TTM to allow freeing an object even when
+ * it's not idle, and using the TTM destroyed list handling could help us
+ * benefit from that.
+ */
+static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj)
+{
+ if (obj->ttm.created) {
+ ttm_bo_put(i915_gem_to_ttm(obj));
+ } else {
+ __i915_gem_free_object(obj);
+ call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
+ }
+}
+
+static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
+{
+ struct vm_area_struct *area = vmf->vma;
+ struct drm_i915_gem_object *obj =
+ i915_ttm_to_gem(area->vm_private_data);
+
+ /* Sanity check that we allow writing into this object */
+ if (unlikely(i915_gem_object_is_readonly(obj) &&
+ area->vm_flags & VM_WRITE))
+ return VM_FAULT_SIGBUS;
+
+ return ttm_bo_vm_fault(vmf);
+}
+
+static int
+vm_access_ttm(struct vm_area_struct *area, unsigned long addr,
+ void *buf, int len, int write)
+{
+ struct drm_i915_gem_object *obj =
+ i915_ttm_to_gem(area->vm_private_data);
+
+ if (i915_gem_object_is_readonly(obj) && write)
+ return -EACCES;
+
+ return ttm_bo_vm_access(area, addr, buf, len, write);
+}
+
+static void ttm_vm_open(struct vm_area_struct *vma)
+{
+ struct drm_i915_gem_object *obj =
+ i915_ttm_to_gem(vma->vm_private_data);
+
+ GEM_BUG_ON(!obj);
+ i915_gem_object_get(obj);
+}
+
+static void ttm_vm_close(struct vm_area_struct *vma)
+{
+ struct drm_i915_gem_object *obj =
+ i915_ttm_to_gem(vma->vm_private_data);
+
+ GEM_BUG_ON(!obj);
+ i915_gem_object_put(obj);
+}
+
+static const struct vm_operations_struct vm_ops_ttm = {
+ .fault = vm_fault_ttm,
+ .access = vm_access_ttm,
+ .open = ttm_vm_open,
+ .close = ttm_vm_close,
+};
+
+static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
+{
+ /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */
+ GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node));
+
+ return drm_vma_node_offset_addr(&obj->base.vma_node);
+}
+
+static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
+ .name = "i915_gem_object_ttm",
+
+ .get_pages = i915_ttm_get_pages,
+ .put_pages = i915_ttm_put_pages,
+ .truncate = i915_ttm_purge,
+ .adjust_lru = i915_ttm_adjust_lru,
+ .delayed_free = i915_ttm_delayed_free,
+ .migrate = i915_ttm_migrate,
+ .mmap_offset = i915_ttm_mmap_offset,
+ .mmap_ops = &vm_ops_ttm,
+};
+
+void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
+{
+ struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
+
+ i915_gem_object_release_memory_region(obj);
+ mutex_destroy(&obj->ttm.get_io_page.lock);
+ if (obj->ttm.created)
+ call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
+}
+
+/**
+ * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
+ * @mem: The initial memory region for the object.
+ * @obj: The gem object.
+ * @size: Object size in bytes.
+ * @flags: gem object flags.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
+ struct drm_i915_gem_object *obj,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags)
+{
+ static struct lock_class_key lock_class;
+ struct drm_i915_private *i915 = mem->i915;
+ struct ttm_operation_ctx ctx = {
+ .interruptible = true,
+ .no_wait_gpu = false,
+ };
+ enum ttm_bo_type bo_type;
+ int ret;
+
+ drm_gem_private_object_init(&i915->drm, &obj->base, size);
+ i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags);
+ i915_gem_object_init_memory_region(obj, mem);
+ i915_gem_object_make_unshrinkable(obj);
+ INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN);
+ mutex_init(&obj->ttm.get_io_page.lock);
+ bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device :
+ ttm_bo_type_kernel;
+
+ obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
+
+ /* Forcing the page size is kernel internal only */
+ GEM_BUG_ON(page_size && obj->mm.n_placements);
+
+ /*
+ * If this function fails, it will call the destructor, but
+ * our caller still owns the object. So no freeing in the
+ * destructor until obj->ttm.created is true.
+ * Similarly, in delayed_destroy, we can't call ttm_bo_put()
+ * until successful initialization.
+ */
+ ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size,
+ bo_type, &i915_sys_placement,
+ page_size >> PAGE_SHIFT,
+ &ctx, NULL, NULL, i915_ttm_bo_destroy);
+ if (ret)
+ return i915_ttm_err_to_gem(ret);
+
+ obj->ttm.created = true;
+ i915_ttm_adjust_domains_after_move(obj);
+ i915_ttm_adjust_gem_after_move(obj);
+ i915_gem_object_unlock(obj);
+
+ return 0;
+}
+
+static const struct intel_memory_region_ops ttm_system_region_ops = {
+ .init_object = __i915_gem_ttm_object_init,
+};
+
+struct intel_memory_region *
+i915_gem_ttm_system_setup(struct drm_i915_private *i915,
+ u16 type, u16 instance)
+{
+ struct intel_memory_region *mr;
+
+ mr = intel_memory_region_create(i915, 0,
+ totalram_pages() << PAGE_SHIFT,
+ PAGE_SIZE, 0,
+ type, instance,
+ &ttm_system_region_ops);
+ if (IS_ERR(mr))
+ return mr;
+
+ intel_memory_region_set_name(mr, "system-ttm");
+ return mr;
+}