diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_ttm.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c new file mode 100644 index 000000000000..2695b8c37e13 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -0,0 +1,540 @@ +// 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" + +#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 + +/** + * 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 lmem0_sys_placement_flags[] = { + { + .fpfn = 0, + .lpfn = 0, + .mem_type = I915_PL_LMEM0, + .flags = 0, + }, { + .fpfn = 0, + .lpfn = 0, + .mem_type = I915_PL_SYSTEM, + .flags = 0, + } +}; + +static struct ttm_placement i915_lmem0_placement = { + .num_placement = 1, + .placement = &lmem0_sys_placement_flags[0], + .num_busy_placement = 1, + .busy_placement = &lmem0_sys_placement_flags[0], +}; + +static struct ttm_placement i915_sys_placement = { + .num_placement = 1, + .placement = &lmem0_sys_placement_flags[1], + .num_busy_placement = 1, + .busy_placement = &lmem0_sys_placement_flags[1], +}; + +static void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj); + +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, ttm_write_combined); + 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); + 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 */ + if (!i915_gem_object_evictable(obj)) + return false; + + /* This isn't valid with a buddy allocator */ + return ttm_bo_eviction_valuable(bo, place); +} + +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) +{ + if (obj->ttm.cached_io_st) { + sg_free_table(obj->ttm.cached_io_st); + kfree(obj->ttm.cached_io_st); + obj->ttm.cached_io_st = NULL; + } +} + +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) { + 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_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); + struct scatterlist *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); + + 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)) { + kfree(st); + return ERR_CAST(sg); + } + + 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); + struct ttm_resource_manager *man = + ttm_manager_type(bo->bdev, res->mem_type); + + if (man->use_tt) + return i915_ttm_tt_get_st(bo->ttm); + + return intel_region_ttm_node_to_st(obj->mm.region, res); +} + +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 ttm_resource_manager *src_man = + ttm_manager_type(bo->bdev, bo->resource->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); + + /* If we start mapping GGTT, we can no longer use man::use_tt here. */ + dst_iter = dst_man->use_tt ? + 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 = src_man->use_tt ? + 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); + ttm_bo_move_sync_cleanup(bo, dst_mem); + i915_ttm_free_cached_io_st(obj); + + if (!dst_man->use_tt) + obj->ttm.cached_io_st = dst_st; + + return 0; +} + +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, +}; + +/** + * 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_buffer_object *bo = i915_gem_to_ttm(obj); + struct ttm_operation_ctx ctx = { + .interruptible = true, + .no_wait_gpu = false, + }; + struct sg_table *st; + int ret; + + /* Move to the requested placement. */ + ret = ttm_bo_validate(bo, &i915_lmem0_placement, &ctx); + if (ret) + return ret == -ENOSPC ? -ENXIO : ret; + + /* 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)); + + i915_ttm_adjust_lru(obj); + + return ret; +} + +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 const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { + .name = "i915_gem_object_ttm", + .flags = I915_GEM_OBJECT_HAS_IOMEM, + + .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, +}; + +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); + 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, + unsigned int flags) +{ + static struct lock_class_key lock_class; + struct drm_i915_private *i915 = mem->i915; + enum ttm_bo_type bo_type; + size_t alignment = 0; + int ret; + + /* Adjust alignment to GPU- and CPU huge page sizes. */ + + if (mem->is_range_manager) { + if (size >= SZ_1G) + alignment = SZ_1G >> PAGE_SHIFT; + else if (size >= SZ_2M) + alignment = SZ_2M >> PAGE_SHIFT; + else if (size >= SZ_64K) + alignment = SZ_64K >> PAGE_SHIFT; + } + + 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); + obj->read_domains = I915_GEM_DOMAIN_WC | I915_GEM_DOMAIN_GTT; + i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE); + + bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : + ttm_bo_type_kernel; + + /* + * 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(&i915->bdev, i915_gem_to_ttm(obj), size, + bo_type, &i915_sys_placement, alignment, + true, NULL, NULL, i915_ttm_bo_destroy); + + if (!ret) + obj->ttm.created = true; + + /* i915 wants -ENXIO when out of memory region space. */ + return (ret == -ENOSPC) ? -ENXIO : ret; +} |