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 | 1293 |
1 files changed, 1293 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 000000000..be4c081e7 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -0,0 +1,1293 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2021 Intel Corporation + */ + +#include <linux/shmem_fs.h> + +#include <drm/ttm/ttm_bo_driver.h> +#include <drm/ttm/ttm_placement.h> +#include <drm/drm_buddy.h> + +#include "i915_drv.h" +#include "i915_ttm_buddy_manager.h" +#include "intel_memory_region.h" +#include "intel_region_ttm.h" + +#include "gem/i915_gem_mman.h" +#include "gem/i915_gem_object.h" +#include "gem/i915_gem_region.h" +#include "gem/i915_gem_ttm.h" +#include "gem/i915_gem_ttm_move.h" +#include "gem/i915_gem_ttm_pm.h" +#include "gt/intel_gpu_commands.h" + +#define I915_TTM_PRIO_PURGE 0 +#define I915_TTM_PRIO_NO_PAGES 1 +#define I915_TTM_PRIO_HAS_PAGES 2 +#define I915_TTM_PRIO_NEEDS_CPU_ACCESS 3 + +/* + * 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_rsgt: The cached scatter-gather table. + * @is_shmem: Set if using shmem. + * @filp: The shmem file, if using shmem backend. + * + * 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 i915_refct_sgt cached_rsgt; + + bool is_shmem; + struct file *filp; +}; + +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, +}; + +/** + * i915_ttm_sys_placement - Return the struct ttm_placement to be + * used for an object in system memory. + * + * Rather than making the struct extern, use this + * function. + * + * Return: A pointer to a static variable for sys placement. + */ +struct ttm_placement *i915_ttm_sys_placement(void) +{ + return &i915_sys_placement; +} + +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 enum ttm_caching +i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj) +{ + /* + * Objects only allowed in system get cached cpu-mappings, or when + * evicting lmem-only buffers to system for swapping. Other objects get + * WC mapping for now. Even if in system. + */ + if (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, + resource_size_t offset, + resource_size_t size, + unsigned int flags) +{ + memset(place, 0, sizeof(*place)); + place->mem_type = intel_region_to_ttm_type(mr); + + if (mr->type == INTEL_MEMORY_SYSTEM) + return; + + if (flags & I915_BO_ALLOC_CONTIGUOUS) + place->flags |= TTM_PL_FLAG_CONTIGUOUS; + if (offset != I915_BO_INVALID_OFFSET) { + place->fpfn = offset >> PAGE_SHIFT; + place->lpfn = place->fpfn + (size >> PAGE_SHIFT); + } else if (mr->io_size && mr->io_size < mr->total) { + if (flags & I915_BO_ALLOC_GPU_ONLY) { + place->flags |= TTM_PL_FLAG_TOPDOWN; + } else { + place->fpfn = 0; + place->lpfn = mr->io_size >> PAGE_SHIFT; + } + } +} + +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, obj->bo_offset, + obj->base.size, 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, + obj->bo_offset, obj->base.size, flags); + + if (num_allowed == 0) { + *busy = *requested; + placement->num_busy_placement = 1; + } + + placement->placement = requested; + placement->busy_placement = busy; +} + +static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev, + struct ttm_tt *ttm, + struct ttm_operation_ctx *ctx) +{ + struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev); + struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM]; + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); + const unsigned int max_segment = i915_sg_segment_size(i915->drm.dev); + const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT; + struct file *filp = i915_tt->filp; + struct sgt_iter sgt_iter; + struct sg_table *st; + struct page *page; + unsigned long i; + int err; + + if (!filp) { + struct address_space *mapping; + gfp_t mask; + + filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE); + if (IS_ERR(filp)) + return PTR_ERR(filp); + + mask = GFP_HIGHUSER | __GFP_RECLAIMABLE; + + mapping = filp->f_mapping; + mapping_set_gfp_mask(mapping, mask); + GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM)); + + i915_tt->filp = filp; + } + + st = &i915_tt->cached_rsgt.table; + err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping, + max_segment); + if (err) + return err; + + err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, + DMA_ATTR_SKIP_CPU_SYNC); + if (err) + goto err_free_st; + + i = 0; + for_each_sgt_page(page, sgt_iter, st) + ttm->pages[i++] = page; + + if (ttm->page_flags & TTM_TT_FLAG_SWAPPED) + ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; + + return 0; + +err_free_st: + shmem_sg_free_table(st, filp->f_mapping, false, false); + + return err; +} + +static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) +{ + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); + bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED; + struct sg_table *st = &i915_tt->cached_rsgt.table; + + shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping, + backup, backup); +} + +static void i915_ttm_tt_release(struct kref *ref) +{ + struct i915_ttm_tt *i915_tt = + container_of(ref, typeof(*i915_tt), cached_rsgt.kref); + struct sg_table *st = &i915_tt->cached_rsgt.table; + + GEM_WARN_ON(st->sgl); + + kfree(i915_tt); +} + +static const struct i915_refct_sgt_ops tt_rsgt_ops = { + .release = i915_ttm_tt_release +}; + +static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, + uint32_t page_flags) +{ + struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915), + bdev); + 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); + unsigned long ccs_pages = 0; + enum ttm_caching caching; + struct i915_ttm_tt *i915_tt; + int ret; + + if (i915_ttm_is_ghost_object(bo)) + return NULL; + + 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_TT_FLAG_ZERO_ALLOC; + + caching = i915_ttm_select_tt_caching(obj); + if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) { + page_flags |= TTM_TT_FLAG_EXTERNAL | + TTM_TT_FLAG_EXTERNAL_MAPPABLE; + i915_tt->is_shmem = true; + } + + if (i915_gem_object_needs_ccs_pages(obj)) + ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size, + NUM_BYTES_PER_CCS_BYTE), + PAGE_SIZE); + + ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, ccs_pages); + if (ret) + goto err_free; + + __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size, + &tt_rsgt_ops); + + i915_tt->dev = obj->base.dev->dev; + + return &i915_tt->ttm; + +err_free: + kfree(i915_tt); + return NULL; +} + +static int i915_ttm_tt_populate(struct ttm_device *bdev, + struct ttm_tt *ttm, + struct ttm_operation_ctx *ctx) +{ + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); + + if (i915_tt->is_shmem) + return i915_ttm_tt_shmem_populate(bdev, ttm, ctx); + + return ttm_pool_alloc(&bdev->pool, ttm, ctx); +} + +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); + struct sg_table *st = &i915_tt->cached_rsgt.table; + + if (st->sgl) + dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); + + if (i915_tt->is_shmem) { + i915_ttm_tt_shmem_unpopulate(ttm); + } else { + sg_free_table(st); + 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); + + if (i915_tt->filp) + fput(i915_tt->filp); + + ttm_tt_fini(ttm); + i915_refct_sgt_put(&i915_tt->cached_rsgt); +} + +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); + + if (i915_ttm_is_ghost_object(bo)) + return false; + + /* + * EXTERNAL objects should never be swapped out by TTM, instead we need + * to handle that ourselves. TTM will already skip such objects for us, + * but we would like to avoid grabbing locks for no good reason. + */ + if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL) + return false; + + /* Will do for now. Our pinned objects are still on TTM's LRU lists */ + if (!i915_gem_object_evictable(obj)) + return false; + + 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; +} + +/** + * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information + * @obj: The GEM object + * This function frees any LMEM-related information that is cached on + * the object. For example the radix tree for fast page lookup and the + * cached refcounted sg-table + */ +void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj) +{ + struct radix_tree_iter iter; + void __rcu **slot; + + if (!obj->ttm.cached_io_rsgt) + 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(); + + i915_refct_sgt_put(obj->ttm.cached_io_rsgt); + obj->ttm.cached_io_rsgt = NULL; +} + +/** + * i915_ttm_purge - Clear an object of its memory + * @obj: The object + * + * This function is called to clear an object of it's memory when it is + * marked as not needed anymore. + * + * Return: 0 on success, negative error code on failure. + */ +int i915_ttm_purge(struct drm_i915_gem_object *obj) +{ + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + struct i915_ttm_tt *i915_tt = + container_of(bo->ttm, typeof(*i915_tt), ttm); + 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 0; + + ret = ttm_bo_validate(bo, &place, &ctx); + if (ret) + return ret; + + if (bo->ttm && i915_tt->filp) { + /* + * The below fput(which eventually calls shmem_truncate) might + * be delayed by worker, so when directly called to purge the + * pages(like by the shrinker) we should try to be more + * aggressive and release the pages immediately. + */ + shmem_truncate_range(file_inode(i915_tt->filp), + 0, (loff_t)-1); + fput(fetch_and_zero(&i915_tt->filp)); + } + + obj->write_domain = 0; + obj->read_domains = 0; + i915_ttm_adjust_gem_after_move(obj); + i915_ttm_free_cached_io_rsgt(obj); + obj->mm.madv = __I915_MADV_PURGED; + + return 0; +} + +static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags) +{ + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + struct i915_ttm_tt *i915_tt = + container_of(bo->ttm, typeof(*i915_tt), ttm); + struct ttm_operation_ctx ctx = { + .interruptible = true, + .no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT, + }; + struct ttm_placement place = {}; + int ret; + + if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM) + return 0; + + GEM_BUG_ON(!i915_tt->is_shmem); + + if (!i915_tt->filp) + return 0; + + ret = ttm_bo_wait_ctx(bo, &ctx); + if (ret) + return ret; + + switch (obj->mm.madv) { + case I915_MADV_DONTNEED: + return i915_ttm_purge(obj); + case __I915_MADV_PURGED: + return 0; + } + + if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED) + return 0; + + bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED; + ret = ttm_bo_validate(bo, &place, &ctx); + if (ret) { + bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; + return ret; + } + + if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK) + __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping); + + return 0; +} + +static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) +{ + struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); + + if (bo->resource && !i915_ttm_is_ghost_object(bo)) { + __i915_gem_object_pages_fini(obj); + i915_ttm_free_cached_io_rsgt(obj); + } +} + +static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm) +{ + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); + struct sg_table *st; + int ret; + + if (i915_tt->cached_rsgt.table.sgl) + return i915_refct_sgt_get(&i915_tt->cached_rsgt); + + st = &i915_tt->cached_rsgt.table; + 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(i915_tt->dev), GFP_KERNEL); + if (ret) { + st->sgl = NULL; + return ERR_PTR(ret); + } + + ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); + if (ret) { + sg_free_table(st); + return ERR_PTR(ret); + } + + return i915_refct_sgt_get(&i915_tt->cached_rsgt); +} + +/** + * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the + * resource memory + * @obj: The GEM object used for sg-table caching + * @res: The struct ttm_resource for which an sg-table is requested. + * + * This function returns a refcounted sg-table representing the memory + * pointed to by @res. If @res is the object's current resource it may also + * cache the sg_table on the object or attempt to access an already cached + * sg-table. The refcounted sg-table needs to be put when no-longer in use. + * + * Return: A valid pointer to a struct i915_refct_sgt or error pointer on + * failure. + */ +struct i915_refct_sgt * +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); + u32 page_alignment; + + if (!i915_ttm_gtt_binds_lmem(res)) + return i915_ttm_tt_get_st(bo->ttm); + + page_alignment = bo->page_alignment << PAGE_SHIFT; + if (!page_alignment) + page_alignment = obj->mm.region->min_page_size; + + /* + * If CPU mapping differs, we need to add the ttm_tt pages to + * the resulting st. Might make sense for GGTT. + */ + GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res)); + if (bo->resource == res) { + if (!obj->ttm.cached_io_rsgt) { + struct i915_refct_sgt *rsgt; + + rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region, + res, + page_alignment); + if (IS_ERR(rsgt)) + return rsgt; + + obj->ttm.cached_io_rsgt = rsgt; + } + return i915_refct_sgt_get(obj->ttm.cached_io_rsgt); + } + + return intel_region_ttm_resource_to_rsgt(obj->mm.region, res, + page_alignment); +} + +static int i915_ttm_truncate(struct drm_i915_gem_object *obj) +{ + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + int err; + + WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED); + + err = ttm_bo_wait(bo, true, false); + if (err) + return err; + + err = i915_ttm_move_notify(bo); + if (err) + return err; + + return i915_ttm_purge(obj); +} + +static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) +{ + struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); + int ret; + + if (i915_ttm_is_ghost_object(bo)) + return; + + ret = i915_ttm_move_notify(bo); + GEM_WARN_ON(ret); + GEM_WARN_ON(obj->ttm.cached_io_rsgt); + if (!ret && obj->mm.madv != I915_MADV_WILLNEED) + i915_ttm_purge(obj); +} + +/** + * i915_ttm_resource_mappable - Return true if the ttm resource is CPU + * accessible. + * @res: The TTM resource to check. + * + * This is interesting on small-BAR systems where we may encounter lmem objects + * that can't be accessed via the CPU. + */ +bool i915_ttm_resource_mappable(struct ttm_resource *res) +{ + struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res); + + if (!i915_ttm_cpu_maps_iomem(res)) + return true; + + return bman_res->used_visible_size == bman_res->base.num_pages; +} + +static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) +{ + struct drm_i915_gem_object *obj = i915_ttm_to_gem(mem->bo); + bool unknown_state; + + if (i915_ttm_is_ghost_object(mem->bo)) + return -EINVAL; + + if (!kref_get_unless_zero(&obj->base.refcount)) + return -EINVAL; + + assert_object_held(obj); + + unknown_state = i915_gem_object_has_unknown_state(obj); + i915_gem_object_put(obj); + if (unknown_state) + return -EINVAL; + + if (!i915_ttm_cpu_maps_iomem(mem)) + return 0; + + if (!i915_ttm_resource_mappable(mem)) + return -EINVAL; + + 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); + struct scatterlist *sg; + unsigned long base; + unsigned int ofs; + + GEM_BUG_ON(i915_ttm_is_ghost_object(bo)); + GEM_WARN_ON(bo->ttm); + + base = obj->mm.region->iomap.base - obj->mm.region->region.start; + 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; +} + +/* + * All callbacks need to take care not to downcast a struct ttm_buffer_object + * without checking its subclass, since it might be a TTM ghost object. + */ +static struct ttm_device_funcs i915_ttm_bo_driver = { + .ttm_tt_create = i915_ttm_tt_create, + .ttm_tt_populate = i915_ttm_tt_populate, + .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, + }; + 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); + } + + 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)) { + struct i915_refct_sgt *rsgt = + i915_ttm_resource_get_st(obj, bo->resource); + + if (IS_ERR(rsgt)) + return PTR_ERR(rsgt); + + GEM_BUG_ON(obj->mm.rsgt); + obj->mm.rsgt = rsgt; + __i915_gem_object_set_pages(obj, &rsgt->table, + i915_sg_dma_sizes(rsgt->table.sgl)); + } + + GEM_BUG_ON(bo->ttm && ((obj->base.size >> PAGE_SHIFT) < bo->ttm->num_pages)); + i915_ttm_adjust_lru(obj); + 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, + unsigned int flags) +{ + struct ttm_place requested; + struct ttm_placement placement; + int ret; + + i915_ttm_place_from_region(mr, &requested, obj->bo_offset, + obj->base.size, 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 int i915_ttm_migrate(struct drm_i915_gem_object *obj, + struct intel_memory_region *mr, + unsigned int flags) +{ + return __i915_ttm_migrate(obj, mr, flags); +} + +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. + */ + + if (obj->mm.rsgt) + i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt)); +} + +/** + * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists. + * @obj: The object + */ +void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) +{ + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + struct i915_ttm_tt *i915_tt = + container_of(bo->ttm, typeof(*i915_tt), ttm); + bool shrinkable = + bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm); + + /* + * 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; + + /* + * We skip managing the shrinker LRU in set_pages() and just manage + * everything here. This does at least solve the issue with having + * temporary shmem mappings(like with evicted lmem) not being visible to + * the shrinker. Only our shmem objects are shrinkable, everything else + * we keep as unshrinkable. + * + * To make sure everything plays nice we keep an extra shrink pin in TTM + * if the underlying pages are not currently shrinkable. Once we release + * our pin, like when the pages are moved to shmem, the pages will then + * be added to the shrinker LRU, assuming the caller isn't also holding + * a pin. + * + * TODO: consider maybe also bumping the shrinker list here when we have + * already unpinned it, which should give us something more like an LRU. + * + * TODO: There is a small window of opportunity for this function to + * get called from eviction after we've dropped the last GEM refcount, + * but before the TTM deleted flag is set on the object. Avoid + * adjusting the shrinker list in such cases, since the object is + * not available to the shrinker anyway due to its zero refcount. + * To fix this properly we should move to a TTM shrinker LRU list for + * these objects. + */ + if (kref_get_unless_zero(&obj->base.refcount)) { + if (shrinkable != obj->mm.ttm_shrinkable) { + if (shrinkable) { + if (obj->mm.madv == I915_MADV_WILLNEED) + __i915_gem_object_make_shrinkable(obj); + else + __i915_gem_object_make_purgeable(obj); + } else { + i915_gem_object_make_unshrinkable(obj); + } + + obj->mm.ttm_shrinkable = shrinkable; + } + i915_gem_object_put(obj); + } + + /* + * Put on the correct LRU list depending on the MADV status + */ + spin_lock(&bo->bdev->lru_lock); + if (shrinkable) { + /* Try to keep shmem_tt from being considered for shrinking. */ + bo->priority = TTM_MAX_BO_PRIORITY - 1; + } else if (obj->mm.madv != I915_MADV_WILLNEED) { + bo->priority = I915_TTM_PRIO_PURGE; + } else if (!i915_gem_object_has_pages(obj)) { + bo->priority = I915_TTM_PRIO_NO_PAGES; + } else { + struct ttm_resource_manager *man = + ttm_manager_type(bo->bdev, bo->resource->mem_type); + + /* + * If we need to place an LMEM resource which doesn't need CPU + * access then we should try not to victimize mappable objects + * first, since we likely end up stealing more of the mappable + * portion. And likewise when we try to find space for a mappble + * object, we know not to ever victimize objects that don't + * occupy any mappable pages. + */ + if (i915_ttm_cpu_maps_iomem(bo->resource) && + i915_ttm_buddy_man_visible_size(man) < man->size && + !(obj->flags & I915_BO_ALLOC_GPU_ONLY)) + bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS; + else + bo->priority = I915_TTM_PRIO_HAS_PAGES; + } + + ttm_bo_move_to_lru_tail(bo); + 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) +{ + GEM_BUG_ON(!obj->ttm.created); + + ttm_bo_put(i915_gem_to_ttm(obj)); +} + +static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) +{ + struct vm_area_struct *area = vmf->vma; + struct ttm_buffer_object *bo = area->vm_private_data; + struct drm_device *dev = bo->base.dev; + struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); + intel_wakeref_t wakeref = 0; + vm_fault_t ret; + int idx; + + if (i915_ttm_is_ghost_object(bo)) + return VM_FAULT_SIGBUS; + + /* 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; + + ret = ttm_bo_vm_reserve(bo, vmf); + if (ret) + return ret; + + if (obj->mm.madv != I915_MADV_WILLNEED) { + dma_resv_unlock(bo->base.resv); + return VM_FAULT_SIGBUS; + } + + if (!i915_ttm_resource_mappable(bo->resource)) { + int err = -ENODEV; + int i; + + for (i = 0; i < obj->mm.n_placements; i++) { + struct intel_memory_region *mr = obj->mm.placements[i]; + unsigned int flags; + + if (!mr->io_size && mr->type != INTEL_MEMORY_SYSTEM) + continue; + + flags = obj->flags; + flags &= ~I915_BO_ALLOC_GPU_ONLY; + err = __i915_ttm_migrate(obj, mr, flags); + if (!err) + break; + } + + if (err) { + drm_dbg(dev, "Unable to make resource CPU accessible\n"); + dma_resv_unlock(bo->base.resv); + ret = VM_FAULT_SIGBUS; + goto out_rpm; + } + } + + if (i915_ttm_cpu_maps_iomem(bo->resource)) + wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); + + if (drm_dev_enter(dev, &idx)) { + ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot, + TTM_BO_VM_NUM_PREFAULT); + drm_dev_exit(idx); + } else { + ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot); + } + + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) + goto out_rpm; + + /* + * ttm_bo_vm_reserve() already has dma_resv_lock. + * userfault_count is protected by dma_resv lock and rpm wakeref. + */ + if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) { + obj->userfault_count = 1; + spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list); + spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + } + + if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND) + intel_wakeref_auto(&to_i915(obj->base.dev)->runtime_pm.userfault_wakeref, + msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)); + + i915_ttm_adjust_lru(obj); + + dma_resv_unlock(bo->base.resv); + +out_rpm: + if (wakeref) + intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); + + return ret; +} + +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(i915_ttm_is_ghost_object(vma->vm_private_data)); + 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(i915_ttm_is_ghost_object(vma->vm_private_data)); + 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 void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) +{ + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); + intel_wakeref_t wakeref = 0; + + assert_object_held_shared(obj); + + if (i915_ttm_cpu_maps_iomem(bo->resource)) { + wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); + + /* userfault_count is protected by obj lock and rpm wakeref. */ + if (obj->userfault_count) { + spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + list_del(&obj->userfault_link); + spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + obj->userfault_count = 0; + } + } + + ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); + + if (wakeref) + intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); +} + +static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { + .name = "i915_gem_object_ttm", + .flags = I915_GEM_OBJECT_IS_SHRINKABLE | + I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, + + .get_pages = i915_ttm_get_pages, + .put_pages = i915_ttm_put_pages, + .truncate = i915_ttm_truncate, + .shrink = i915_ttm_shrink, + + .adjust_lru = i915_ttm_adjust_lru, + .delayed_free = i915_ttm_delayed_free, + .migrate = i915_ttm_migrate, + + .mmap_offset = i915_ttm_mmap_offset, + .unmap_virtual = i915_ttm_unmap_virtual, + .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) { + /* + * We freely manage the shrinker LRU outide of the mm.pages life + * cycle. As a result when destroying the object we should be + * extra paranoid and ensure we remove it from the LRU, before + * we free the object. + * + * Touching the ttm_shrinkable outside of the object lock here + * should be safe now that the last GEM object ref was dropped. + */ + if (obj->mm.ttm_shrinkable) + i915_gem_object_make_unshrinkable(obj); + + i915_ttm_backup_free(obj); + + /* This releases all gem object bindings to the backend. */ + __i915_gem_free_object(obj); + + call_rcu(&obj->rcu, __i915_gem_free_object_rcu); + } else { + __i915_gem_object_fini(obj); + } +} + +/** + * __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 offset, + 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); + + obj->bo_offset = offset; + + /* Don't put on a region list until we're either locked or fully initialized. */ + obj->mm.region = mem; + INIT_LIST_HEAD(&obj->mm.region_link); + + 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); + + /* + * Keep an extra shrink pin to prevent the object from being made + * shrinkable too early. If the ttm_tt is ever allocated in shmem, we + * drop the pin. The TTM backend manages the shrinker LRU itself, + * outside of the normal mm.pages life cycle. + */ + i915_gem_object_make_unshrinkable(obj); + + /* + * 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), 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_gem_object_release_memory_region(obj); + i915_gem_object_init_memory_region(obj, mem); + 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, + .release = intel_region_ttm_fini, +}; + +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, 0, + type, instance, + &ttm_system_region_ops); + if (IS_ERR(mr)) + return mr; + + intel_memory_region_set_name(mr, "system-ttm"); + return mr; +} |