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1// SPDX-License-Identifier: MIT2/*3 * Copyright © 2021 Intel Corporation4 */5 6#include <drm/ttm/ttm_tt.h>7 8#include "i915_deps.h"9#include "i915_drv.h"10#include "intel_memory_region.h"11#include "intel_region_ttm.h"12 13#include "gem/i915_gem_object.h"14#include "gem/i915_gem_region.h"15#include "gem/i915_gem_ttm.h"16#include "gem/i915_gem_ttm_move.h"17 18#include "gt/intel_engine_pm.h"19#include "gt/intel_gt.h"20#include "gt/intel_migrate.h"21 22/**23 * DOC: Selftest failure modes for failsafe migration:24 *25 * For fail_gpu_migration, the gpu blit scheduled is always a clear blit26 * rather than a copy blit, and then we force the failure paths as if27 * the blit fence returned an error.28 *29 * For fail_work_allocation we fail the kmalloc of the async worker, we30 * sync the gpu blit. If it then fails, or fail_gpu_migration is set to31 * true, then a memcpy operation is performed sync.32 */33#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)34static bool fail_gpu_migration;35static bool fail_work_allocation;36static bool ban_memcpy;37 38void i915_ttm_migrate_set_failure_modes(bool gpu_migration,39					bool work_allocation)40{41	fail_gpu_migration = gpu_migration;42	fail_work_allocation = work_allocation;43}44 45void i915_ttm_migrate_set_ban_memcpy(bool ban)46{47	ban_memcpy = ban;48}49#endif50 51static enum i915_cache_level52i915_ttm_cache_level(struct drm_i915_private *i915, struct ttm_resource *res,53		     struct ttm_tt *ttm)54{55	return ((HAS_LLC(i915) || HAS_SNOOP(i915)) &&56		!i915_ttm_gtt_binds_lmem(res) &&57		ttm->caching == ttm_cached) ? I915_CACHE_LLC :58		I915_CACHE_NONE;59}60 61static struct intel_memory_region *62i915_ttm_region(struct ttm_device *bdev, int ttm_mem_type)63{64	struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);65 66	/* There's some room for optimization here... */67	GEM_BUG_ON(ttm_mem_type != I915_PL_SYSTEM &&68		   ttm_mem_type < I915_PL_LMEM0);69	if (ttm_mem_type == I915_PL_SYSTEM)70		return intel_memory_region_lookup(i915, INTEL_MEMORY_SYSTEM,71						  0);72 73	return intel_memory_region_lookup(i915, INTEL_MEMORY_LOCAL,74					  ttm_mem_type - I915_PL_LMEM0);75}76 77/**78 * i915_ttm_adjust_domains_after_move - Adjust the GEM domains after a79 * TTM move80 * @obj: The gem object81 */82void i915_ttm_adjust_domains_after_move(struct drm_i915_gem_object *obj)83{84	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);85 86	if (i915_ttm_cpu_maps_iomem(bo->resource) || bo->ttm->caching != ttm_cached) {87		obj->write_domain = I915_GEM_DOMAIN_WC;88		obj->read_domains = I915_GEM_DOMAIN_WC;89	} else {90		obj->write_domain = I915_GEM_DOMAIN_CPU;91		obj->read_domains = I915_GEM_DOMAIN_CPU;92	}93}94 95/**96 * i915_ttm_adjust_gem_after_move - Adjust the GEM state after a TTM move97 * @obj: The gem object98 *99 * Adjusts the GEM object's region, mem_flags and cache coherency after a100 * TTM move.101 */102void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj)103{104	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);105	unsigned int cache_level;106	unsigned int mem_flags;107	unsigned int i;108	int mem_type;109 110	/*111	 * We might have been purged (or swapped out) if the resource is NULL,112	 * in which case the SYSTEM placement is the closest match to describe113	 * the current domain. If the object is ever used in this state then we114	 * will require moving it again.115	 */116	if (!bo->resource) {117		mem_flags = I915_BO_FLAG_STRUCT_PAGE;118		mem_type = I915_PL_SYSTEM;119		cache_level = I915_CACHE_NONE;120	} else {121		mem_flags = i915_ttm_cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :122			I915_BO_FLAG_STRUCT_PAGE;123		mem_type = bo->resource->mem_type;124		cache_level = i915_ttm_cache_level(to_i915(bo->base.dev), bo->resource,125						   bo->ttm);126	}127 128	/*129	 * If object was moved to an allowable region, update the object130	 * region to consider it migrated. Note that if it's currently not131	 * in an allowable region, it's evicted and we don't update the132	 * object region.133	 */134	if (intel_region_to_ttm_type(obj->mm.region) != mem_type) {135		for (i = 0; i < obj->mm.n_placements; ++i) {136			struct intel_memory_region *mr = obj->mm.placements[i];137 138			if (intel_region_to_ttm_type(mr) == mem_type &&139			    mr != obj->mm.region) {140				i915_gem_object_release_memory_region(obj);141				i915_gem_object_init_memory_region(obj, mr);142				break;143			}144		}145	}146 147	obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM);148	obj->mem_flags |= mem_flags;149 150	i915_gem_object_set_cache_coherency(obj, cache_level);151}152 153/**154 * i915_ttm_move_notify - Prepare an object for move155 * @bo: The ttm buffer object.156 *157 * This function prepares an object for move by removing all GPU bindings,158 * removing all CPU mappings and finally releasing the pages sg-table.159 *160 * Return: 0 if successful, negative error code on error.161 */162int i915_ttm_move_notify(struct ttm_buffer_object *bo)163{164	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);165	int ret;166 167	/*168	 * Note: The async unbinding here will actually transform the169	 * blocking wait for unbind into a wait before finally submitting170	 * evict / migration blit and thus stall the migration timeline171	 * which may not be good for overall throughput. We should make172	 * sure we await the unbind fences *after* the migration blit173	 * instead of *before* as we currently do.174	 */175	ret = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE |176				     I915_GEM_OBJECT_UNBIND_ASYNC);177	if (ret)178		return ret;179 180	ret = __i915_gem_object_put_pages(obj);181	if (ret)182		return ret;183 184	return 0;185}186 187static struct dma_fence *i915_ttm_accel_move(struct ttm_buffer_object *bo,188					     bool clear,189					     struct ttm_resource *dst_mem,190					     struct ttm_tt *dst_ttm,191					     struct sg_table *dst_st,192					     const struct i915_deps *deps)193{194	struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915),195						     bdev);196	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);197	struct i915_request *rq;198	struct ttm_tt *src_ttm = bo->ttm;199	enum i915_cache_level src_level, dst_level;200	int ret;201 202	if (!to_gt(i915)->migrate.context || intel_gt_is_wedged(to_gt(i915)))203		return ERR_PTR(-EINVAL);204 205	/* With fail_gpu_migration, we always perform a GPU clear. */206	if (I915_SELFTEST_ONLY(fail_gpu_migration))207		clear = true;208 209	dst_level = i915_ttm_cache_level(i915, dst_mem, dst_ttm);210	if (clear) {211		if (bo->type == ttm_bo_type_kernel &&212		    !I915_SELFTEST_ONLY(fail_gpu_migration))213			return ERR_PTR(-EINVAL);214 215		intel_engine_pm_get(to_gt(i915)->migrate.context->engine);216		ret = intel_context_migrate_clear(to_gt(i915)->migrate.context, deps,217						  dst_st->sgl,218						  i915_gem_get_pat_index(i915, dst_level),219						  i915_ttm_gtt_binds_lmem(dst_mem),220						  0, &rq);221	} else {222		struct i915_refct_sgt *src_rsgt =223			i915_ttm_resource_get_st(obj, bo->resource);224 225		if (IS_ERR(src_rsgt))226			return ERR_CAST(src_rsgt);227 228		src_level = i915_ttm_cache_level(i915, bo->resource, src_ttm);229		intel_engine_pm_get(to_gt(i915)->migrate.context->engine);230		ret = intel_context_migrate_copy(to_gt(i915)->migrate.context,231						 deps, src_rsgt->table.sgl,232						 i915_gem_get_pat_index(i915, src_level),233						 i915_ttm_gtt_binds_lmem(bo->resource),234						 dst_st->sgl,235						 i915_gem_get_pat_index(i915, dst_level),236						 i915_ttm_gtt_binds_lmem(dst_mem),237						 &rq);238 239		i915_refct_sgt_put(src_rsgt);240	}241 242	intel_engine_pm_put(to_gt(i915)->migrate.context->engine);243 244	if (ret && rq) {245		i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT);246		i915_request_put(rq);247	}248 249	return ret ? ERR_PTR(ret) : &rq->fence;250}251 252/**253 * struct i915_ttm_memcpy_arg - argument for the bo memcpy functionality.254 * @_dst_iter: Storage space for the destination kmap iterator.255 * @_src_iter: Storage space for the source kmap iterator.256 * @dst_iter: Pointer to the destination kmap iterator.257 * @src_iter: Pointer to the source kmap iterator.258 * @num_pages: Number of pages259 * @clear: Whether to clear instead of copy.260 * @src_rsgt: Refcounted scatter-gather list of source memory.261 * @dst_rsgt: Refcounted scatter-gather list of destination memory.262 */263struct i915_ttm_memcpy_arg {264	union {265		struct ttm_kmap_iter_tt tt;266		struct ttm_kmap_iter_iomap io;267	} _dst_iter,268	_src_iter;269	struct ttm_kmap_iter *dst_iter;270	struct ttm_kmap_iter *src_iter;271	unsigned long num_pages;272	bool clear;273	struct i915_refct_sgt *src_rsgt;274	struct i915_refct_sgt *dst_rsgt;275};276 277/**278 * struct i915_ttm_memcpy_work - Async memcpy worker under a dma-fence.279 * @fence: The dma-fence.280 * @work: The work struct use for the memcpy work.281 * @lock: The fence lock. Not used to protect anything else ATM.282 * @irq_work: Low latency worker to signal the fence since it can't be done283 * from the callback for lockdep reasons.284 * @cb: Callback for the accelerated migration fence.285 * @arg: The argument for the memcpy functionality.286 * @i915: The i915 pointer.287 * @obj: The GEM object.288 * @memcpy_allowed: Instead of processing the @arg, and falling back to memcpy289 * or memset, we wedge the device and set the @obj unknown_state, to prevent290 * further access to the object with the CPU or GPU.  On some devices we might291 * only be permitted to use the blitter engine for such operations.292 */293struct i915_ttm_memcpy_work {294	struct dma_fence fence;295	struct work_struct work;296	spinlock_t lock;297	struct irq_work irq_work;298	struct dma_fence_cb cb;299	struct i915_ttm_memcpy_arg arg;300	struct drm_i915_private *i915;301	struct drm_i915_gem_object *obj;302	bool memcpy_allowed;303};304 305static void i915_ttm_move_memcpy(struct i915_ttm_memcpy_arg *arg)306{307	ttm_move_memcpy(arg->clear, arg->num_pages,308			arg->dst_iter, arg->src_iter);309}310 311static void i915_ttm_memcpy_init(struct i915_ttm_memcpy_arg *arg,312				 struct ttm_buffer_object *bo, bool clear,313				 struct ttm_resource *dst_mem,314				 struct ttm_tt *dst_ttm,315				 struct i915_refct_sgt *dst_rsgt)316{317	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);318	struct intel_memory_region *dst_reg, *src_reg;319 320	dst_reg = i915_ttm_region(bo->bdev, dst_mem->mem_type);321	src_reg = i915_ttm_region(bo->bdev, bo->resource->mem_type);322	GEM_BUG_ON(!dst_reg || !src_reg);323 324	arg->dst_iter = !i915_ttm_cpu_maps_iomem(dst_mem) ?325		ttm_kmap_iter_tt_init(&arg->_dst_iter.tt, dst_ttm) :326		ttm_kmap_iter_iomap_init(&arg->_dst_iter.io, &dst_reg->iomap,327					 &dst_rsgt->table, dst_reg->region.start);328 329	arg->src_iter = !i915_ttm_cpu_maps_iomem(bo->resource) ?330		ttm_kmap_iter_tt_init(&arg->_src_iter.tt, bo->ttm) :331		ttm_kmap_iter_iomap_init(&arg->_src_iter.io, &src_reg->iomap,332					 &obj->ttm.cached_io_rsgt->table,333					 src_reg->region.start);334	arg->clear = clear;335	arg->num_pages = bo->base.size >> PAGE_SHIFT;336 337	arg->dst_rsgt = i915_refct_sgt_get(dst_rsgt);338	arg->src_rsgt = clear ? NULL :339		i915_ttm_resource_get_st(obj, bo->resource);340}341 342static void i915_ttm_memcpy_release(struct i915_ttm_memcpy_arg *arg)343{344	i915_refct_sgt_put(arg->src_rsgt);345	i915_refct_sgt_put(arg->dst_rsgt);346}347 348static void __memcpy_work(struct work_struct *work)349{350	struct i915_ttm_memcpy_work *copy_work =351		container_of(work, typeof(*copy_work), work);352	struct i915_ttm_memcpy_arg *arg = &copy_work->arg;353	bool cookie;354 355	/*356	 * FIXME: We need to take a closer look here. We should be able to plonk357	 * this into the fence critical section.358	 */359	if (!copy_work->memcpy_allowed) {360		struct intel_gt *gt;361		unsigned int id;362 363		for_each_gt(gt, copy_work->i915, id)364			intel_gt_set_wedged(gt);365	}366 367	cookie = dma_fence_begin_signalling();368 369	if (copy_work->memcpy_allowed) {370		i915_ttm_move_memcpy(arg);371	} else {372		/*373		 * Prevent further use of the object. Any future GTT binding or374		 * CPU access is not allowed once we signal the fence. Outside375		 * of the fence critical section, we then also then wedge the gpu376		 * to indicate the device is not functional.377		 *378		 * The below dma_fence_signal() is our write-memory-barrier.379		 */380		copy_work->obj->mm.unknown_state = true;381	}382 383	dma_fence_end_signalling(cookie);384 385	dma_fence_signal(&copy_work->fence);386 387	i915_ttm_memcpy_release(arg);388	i915_gem_object_put(copy_work->obj);389	dma_fence_put(&copy_work->fence);390}391 392static void __memcpy_irq_work(struct irq_work *irq_work)393{394	struct i915_ttm_memcpy_work *copy_work =395		container_of(irq_work, typeof(*copy_work), irq_work);396	struct i915_ttm_memcpy_arg *arg = &copy_work->arg;397 398	dma_fence_signal(&copy_work->fence);399	i915_ttm_memcpy_release(arg);400	i915_gem_object_put(copy_work->obj);401	dma_fence_put(&copy_work->fence);402}403 404static void __memcpy_cb(struct dma_fence *fence, struct dma_fence_cb *cb)405{406	struct i915_ttm_memcpy_work *copy_work =407		container_of(cb, typeof(*copy_work), cb);408 409	if (unlikely(fence->error || I915_SELFTEST_ONLY(fail_gpu_migration))) {410		INIT_WORK(&copy_work->work, __memcpy_work);411		queue_work(system_unbound_wq, &copy_work->work);412	} else {413		init_irq_work(&copy_work->irq_work, __memcpy_irq_work);414		irq_work_queue(&copy_work->irq_work);415	}416}417 418static const char *get_driver_name(struct dma_fence *fence)419{420	return "i915_ttm_memcpy_work";421}422 423static const char *get_timeline_name(struct dma_fence *fence)424{425	return "unbound";426}427 428static const struct dma_fence_ops dma_fence_memcpy_ops = {429	.get_driver_name = get_driver_name,430	.get_timeline_name = get_timeline_name,431};432 433static struct dma_fence *434i915_ttm_memcpy_work_arm(struct i915_ttm_memcpy_work *work,435			 struct dma_fence *dep)436{437	int ret;438 439	spin_lock_init(&work->lock);440	dma_fence_init(&work->fence, &dma_fence_memcpy_ops, &work->lock, 0, 0);441	dma_fence_get(&work->fence);442	ret = dma_fence_add_callback(dep, &work->cb, __memcpy_cb);443	if (ret) {444		if (ret != -ENOENT)445			dma_fence_wait(dep, false);446 447		return ERR_PTR(I915_SELFTEST_ONLY(fail_gpu_migration) ? -EINVAL :448			       dep->error);449	}450 451	return &work->fence;452}453 454static bool i915_ttm_memcpy_allowed(struct ttm_buffer_object *bo,455				    struct ttm_resource *dst_mem)456{457	if (i915_gem_object_needs_ccs_pages(i915_ttm_to_gem(bo)))458		return false;459 460	if (!(i915_ttm_resource_mappable(bo->resource) &&461	      i915_ttm_resource_mappable(dst_mem)))462		return false;463 464	return I915_SELFTEST_ONLY(ban_memcpy) ? false : true;465}466 467static struct dma_fence *468__i915_ttm_move(struct ttm_buffer_object *bo,469		const struct ttm_operation_ctx *ctx, bool clear,470		struct ttm_resource *dst_mem, struct ttm_tt *dst_ttm,471		struct i915_refct_sgt *dst_rsgt, bool allow_accel,472		const struct i915_deps *move_deps)473{474	const bool memcpy_allowed = i915_ttm_memcpy_allowed(bo, dst_mem);475	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);476	struct drm_i915_private *i915 = to_i915(bo->base.dev);477	struct i915_ttm_memcpy_work *copy_work = NULL;478	struct i915_ttm_memcpy_arg _arg, *arg = &_arg;479	struct dma_fence *fence = ERR_PTR(-EINVAL);480 481	if (allow_accel) {482		fence = i915_ttm_accel_move(bo, clear, dst_mem, dst_ttm,483					    &dst_rsgt->table, move_deps);484 485		/*486		 * We only need to intercept the error when moving to lmem.487		 * When moving to system, TTM or shmem will provide us with488		 * cleared pages.489		 */490		if (!IS_ERR(fence) && !i915_ttm_gtt_binds_lmem(dst_mem) &&491		    !I915_SELFTEST_ONLY(fail_gpu_migration ||492					fail_work_allocation))493			goto out;494	}495 496	/* If we've scheduled gpu migration. Try to arm error intercept. */497	if (!IS_ERR(fence)) {498		struct dma_fence *dep = fence;499 500		if (!I915_SELFTEST_ONLY(fail_work_allocation))501			copy_work = kzalloc(sizeof(*copy_work), GFP_KERNEL);502 503		if (copy_work) {504			copy_work->i915 = i915;505			copy_work->memcpy_allowed = memcpy_allowed;506			copy_work->obj = i915_gem_object_get(obj);507			arg = &copy_work->arg;508			if (memcpy_allowed)509				i915_ttm_memcpy_init(arg, bo, clear, dst_mem,510						     dst_ttm, dst_rsgt);511 512			fence = i915_ttm_memcpy_work_arm(copy_work, dep);513		} else {514			dma_fence_wait(dep, false);515			fence = ERR_PTR(I915_SELFTEST_ONLY(fail_gpu_migration) ?516					-EINVAL : fence->error);517		}518		dma_fence_put(dep);519 520		if (!IS_ERR(fence))521			goto out;522	} else {523		int err = PTR_ERR(fence);524 525		if (err == -EINTR || err == -ERESTARTSYS || err == -EAGAIN)526			return fence;527 528		if (move_deps) {529			err = i915_deps_sync(move_deps, ctx);530			if (err)531				return ERR_PTR(err);532		}533	}534 535	/* Error intercept failed or no accelerated migration to start with */536 537	if (memcpy_allowed) {538		if (!copy_work)539			i915_ttm_memcpy_init(arg, bo, clear, dst_mem, dst_ttm,540					     dst_rsgt);541		i915_ttm_move_memcpy(arg);542		i915_ttm_memcpy_release(arg);543	}544	if (copy_work)545		i915_gem_object_put(copy_work->obj);546	kfree(copy_work);547 548	return memcpy_allowed ? NULL : ERR_PTR(-EIO);549out:550	if (!fence && copy_work) {551		i915_ttm_memcpy_release(arg);552		i915_gem_object_put(copy_work->obj);553		kfree(copy_work);554	}555 556	return fence;557}558 559/**560 * i915_ttm_move - The TTM move callback used by i915.561 * @bo: The buffer object.562 * @evict: Whether this is an eviction.563 * @ctx: Pointer to a struct ttm_operation_ctx indicating how the waits should be564 *       performed if waiting565 * @dst_mem: The destination ttm resource.566 * @hop: If we need multihop, what temporary memory type to move to.567 *568 * Return: 0 if successful, negative error code otherwise.569 */570int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,571		  struct ttm_operation_ctx *ctx,572		  struct ttm_resource *dst_mem,573		  struct ttm_place *hop)574{575	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);576	struct ttm_resource_manager *dst_man =577		ttm_manager_type(bo->bdev, dst_mem->mem_type);578	struct dma_fence *migration_fence = NULL;579	struct ttm_tt *ttm = bo->ttm;580	struct i915_refct_sgt *dst_rsgt;581	bool clear, prealloc_bo;582	int ret;583 584	if (GEM_WARN_ON(i915_ttm_is_ghost_object(bo))) {585		ttm_bo_move_null(bo, dst_mem);586		return 0;587	}588 589	if (!bo->resource) {590		if (dst_mem->mem_type != TTM_PL_SYSTEM) {591			hop->mem_type = TTM_PL_SYSTEM;592			hop->flags = TTM_PL_FLAG_TEMPORARY;593			return -EMULTIHOP;594		}595 596		/*597		 * This is only reached when first creating the object, or if598		 * the object was purged or swapped out (pipeline-gutting). For599		 * the former we can safely skip all of the below since we are600		 * only using a dummy SYSTEM placement here. And with the latter601		 * we will always re-enter here with bo->resource set correctly602		 * (as per the above), since this is part of a multi-hop603		 * sequence, where at the end we can do the move for real.604		 *605		 * The special case here is when the dst_mem is TTM_PL_SYSTEM,606		 * which doens't require any kind of move, so it should be safe607		 * to skip all the below and call ttm_bo_move_null() here, where608		 * the caller in __i915_ttm_get_pages() will take care of the609		 * rest, since we should have a valid ttm_tt.610		 */611		ttm_bo_move_null(bo, dst_mem);612		return 0;613	}614 615	ret = i915_ttm_move_notify(bo);616	if (ret)617		return ret;618 619	if (obj->mm.madv != I915_MADV_WILLNEED) {620		i915_ttm_purge(obj);621		ttm_resource_free(bo, &dst_mem);622		return 0;623	}624 625	/* Populate ttm with pages if needed. Typically system memory. */626	if (ttm && (dst_man->use_tt || (ttm->page_flags & TTM_TT_FLAG_SWAPPED))) {627		ret = ttm_tt_populate(bo->bdev, ttm, ctx);628		if (ret)629			return ret;630	}631 632	dst_rsgt = i915_ttm_resource_get_st(obj, dst_mem);633	if (IS_ERR(dst_rsgt))634		return PTR_ERR(dst_rsgt);635 636	clear = !i915_ttm_cpu_maps_iomem(bo->resource) && (!ttm || !ttm_tt_is_populated(ttm));637	prealloc_bo = obj->flags & I915_BO_PREALLOC;638	if (!(clear && ttm && !((ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC) && !prealloc_bo))) {639		struct i915_deps deps;640 641		i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);642		ret = i915_deps_add_resv(&deps, bo->base.resv, ctx);643		if (ret) {644			i915_refct_sgt_put(dst_rsgt);645			return ret;646		}647 648		migration_fence = __i915_ttm_move(bo, ctx, clear, dst_mem, ttm,649						  dst_rsgt, true, &deps);650		i915_deps_fini(&deps);651	}652 653	/* We can possibly get an -ERESTARTSYS here */654	if (IS_ERR(migration_fence)) {655		i915_refct_sgt_put(dst_rsgt);656		return PTR_ERR(migration_fence);657	}658 659	if (migration_fence) {660		if (I915_SELFTEST_ONLY(evict && fail_gpu_migration))661			ret = -EIO; /* never feed non-migrate fences into ttm */662		else663			ret = ttm_bo_move_accel_cleanup(bo, migration_fence, evict,664							true, dst_mem);665		if (ret) {666			dma_fence_wait(migration_fence, false);667			ttm_bo_move_sync_cleanup(bo, dst_mem);668		}669		dma_fence_put(migration_fence);670	} else {671		ttm_bo_move_sync_cleanup(bo, dst_mem);672	}673 674	i915_ttm_adjust_domains_after_move(obj);675	i915_ttm_free_cached_io_rsgt(obj);676 677	if (i915_ttm_gtt_binds_lmem(dst_mem) || i915_ttm_cpu_maps_iomem(dst_mem)) {678		obj->ttm.cached_io_rsgt = dst_rsgt;679		obj->ttm.get_io_page.sg_pos = dst_rsgt->table.sgl;680		obj->ttm.get_io_page.sg_idx = 0;681	} else {682		i915_refct_sgt_put(dst_rsgt);683	}684 685	i915_ttm_adjust_lru(obj);686	i915_ttm_adjust_gem_after_move(obj);687	return 0;688}689 690/**691 * i915_gem_obj_copy_ttm - Copy the contents of one ttm-based gem object to692 * another693 * @dst: The destination object694 * @src: The source object695 * @allow_accel: Allow using the blitter. Otherwise TTM memcpy is used.696 * @intr: Whether to perform waits interruptible:697 *698 * Note: The caller is responsible for assuring that the underlying699 * TTM objects are populated if needed and locked.700 *701 * Return: Zero on success. Negative error code on error. If @intr == true,702 * then it may return -ERESTARTSYS or -EINTR.703 */704int i915_gem_obj_copy_ttm(struct drm_i915_gem_object *dst,705			  struct drm_i915_gem_object *src,706			  bool allow_accel, bool intr)707{708	struct ttm_buffer_object *dst_bo = i915_gem_to_ttm(dst);709	struct ttm_buffer_object *src_bo = i915_gem_to_ttm(src);710	struct ttm_operation_ctx ctx = {711		.interruptible = intr,712	};713	struct i915_refct_sgt *dst_rsgt;714	struct dma_fence *copy_fence;715	struct i915_deps deps;716	int ret;717 718	assert_object_held(dst);719	assert_object_held(src);720 721	if (GEM_WARN_ON(!src_bo->resource || !dst_bo->resource))722		return -EINVAL;723 724	i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);725 726	ret = dma_resv_reserve_fences(src_bo->base.resv, 1);727	if (ret)728		return ret;729 730	ret = dma_resv_reserve_fences(dst_bo->base.resv, 1);731	if (ret)732		return ret;733 734	ret = i915_deps_add_resv(&deps, dst_bo->base.resv, &ctx);735	if (ret)736		return ret;737 738	ret = i915_deps_add_resv(&deps, src_bo->base.resv, &ctx);739	if (ret)740		return ret;741 742	dst_rsgt = i915_ttm_resource_get_st(dst, dst_bo->resource);743	copy_fence = __i915_ttm_move(src_bo, &ctx, false, dst_bo->resource,744				     dst_bo->ttm, dst_rsgt, allow_accel,745				     &deps);746 747	i915_deps_fini(&deps);748	i915_refct_sgt_put(dst_rsgt);749	if (IS_ERR_OR_NULL(copy_fence))750		return PTR_ERR_OR_ZERO(copy_fence);751 752	dma_resv_add_fence(dst_bo->base.resv, copy_fence, DMA_RESV_USAGE_WRITE);753	dma_resv_add_fence(src_bo->base.resv, copy_fence, DMA_RESV_USAGE_READ);754	dma_fence_put(copy_fence);755 756	return 0;757}758