ttm_bo.c

   1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2/**************************************************************************
   3 *
   4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   5 * All Rights Reserved.
   6 *
   7 * Permission is hereby granted, free of charge, to any person obtaining a
   8 * copy of this software and associated documentation files (the
   9 * "Software"), to deal in the Software without restriction, including
  10 * without limitation the rights to use, copy, modify, merge, publish,
  11 * distribute, sub license, and/or sell copies of the Software, and to
  12 * permit persons to whom the Software is furnished to do so, subject to
  13 * the following conditions:
  14 *
  15 * The above copyright notice and this permission notice (including the
  16 * next paragraph) shall be included in all copies or substantial portions
  17 * of the Software.
  18 *
  19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26 *
  27 **************************************************************************/
  28/*
  29 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  30 */
  31
  32#define pr_fmt(fmt) "[TTM] " fmt
  33
  34#include <drm/drm_print.h>
  35#include <drm/ttm/ttm_allocation.h>
  36#include <drm/ttm/ttm_bo.h>
  37#include <drm/ttm/ttm_placement.h>
  38#include <drm/ttm/ttm_tt.h>
  39
  40#include <linux/export.h>
  41#include <linux/jiffies.h>
  42#include <linux/slab.h>
  43#include <linux/sched.h>
  44#include <linux/mm.h>
  45#include <linux/file.h>
  46#include <linux/module.h>
  47#include <linux/atomic.h>
  48#include <linux/cgroup_dmem.h>
  49#include <linux/dma-resv.h>
  50
  51#include "ttm_module.h"
  52#include "ttm_bo_internal.h"
  53
  54static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
  55					struct ttm_placement *placement)
  56{
  57	struct drm_printer p = drm_dbg_printer(NULL, DRM_UT_CORE, TTM_PFX);
  58	struct ttm_resource_manager *man;
  59	int i, mem_type;
  60
  61	for (i = 0; i < placement->num_placement; i++) {
  62		mem_type = placement->placement[i].mem_type;
  63		drm_printf(&p, "  placement[%d]=0x%08X (%d)\n",
  64			   i, placement->placement[i].flags, mem_type);
  65		man = ttm_manager_type(bo->bdev, mem_type);
  66		ttm_resource_manager_debug(man, &p);
  67	}
  68}
  69
  70/**
  71 * ttm_bo_move_to_lru_tail
  72 *
  73 * @bo: The buffer object.
  74 *
  75 * Move this BO to the tail of all lru lists used to lookup and reserve an
  76 * object. This function must be called with struct ttm_global::lru_lock
  77 * held, and is used to make a BO less likely to be considered for eviction.
  78 */
  79void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo)
  80{
  81	dma_resv_assert_held(bo->base.resv);
  82
  83	if (bo->resource)
  84		ttm_resource_move_to_lru_tail(bo->resource);
  85}
  86EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
  87
  88/**
  89 * ttm_bo_set_bulk_move - update BOs bulk move object
  90 *
  91 * @bo: The buffer object.
  92 * @bulk: bulk move structure
  93 *
  94 * Update the BOs bulk move object, making sure that resources are added/removed
  95 * as well. A bulk move allows to move many resource on the LRU at once,
  96 * resulting in much less overhead of maintaining the LRU.
  97 * The only requirement is that the resources stay together on the LRU and are
  98 * never separated. This is enforces by setting the bulk_move structure on a BO.
  99 * ttm_lru_bulk_move_tail() should be used to move all resources to the tail of
 100 * their LRU list.
 101 */
 102void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
 103			  struct ttm_lru_bulk_move *bulk)
 104{
 105	dma_resv_assert_held(bo->base.resv);
 106
 107	if (bo->bulk_move == bulk)
 108		return;
 109
 110	spin_lock(&bo->bdev->lru_lock);
 111	if (bo->resource)
 112		ttm_resource_del_bulk_move(bo->resource, bo);
 113	bo->bulk_move = bulk;
 114	if (bo->resource)
 115		ttm_resource_add_bulk_move(bo->resource, bo);
 116	spin_unlock(&bo->bdev->lru_lock);
 117}
 118EXPORT_SYMBOL(ttm_bo_set_bulk_move);
 119
 120static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 121				  struct ttm_resource *mem, bool evict,
 122				  struct ttm_operation_ctx *ctx,
 123				  struct ttm_place *hop)
 124{
 125	struct ttm_device *bdev = bo->bdev;
 126	bool old_use_tt, new_use_tt;
 127	int ret;
 128
 129	old_use_tt = !bo->resource || ttm_manager_type(bdev, bo->resource->mem_type)->use_tt;
 130	new_use_tt = ttm_manager_type(bdev, mem->mem_type)->use_tt;
 131
 132	ttm_bo_unmap_virtual(bo);
 133
 134	/*
 135	 * Create and bind a ttm if required.
 136	 */
 137
 138	if (new_use_tt) {
 139		/* Zero init the new TTM structure if the old location should
 140		 * have used one as well.
 141		 */
 142		ret = ttm_tt_create(bo, old_use_tt);
 143		if (ret)
 144			goto out_err;
 145
 146		if (mem->mem_type != TTM_PL_SYSTEM) {
 147			ret = ttm_bo_populate(bo, ctx);
 148			if (ret)
 149				goto out_err;
 150		}
 151	}
 152
 153	ret = dma_resv_reserve_fences(bo->base.resv, 1);
 154	if (ret)
 155		goto out_err;
 156
 157	ret = bdev->funcs->move(bo, evict, ctx, mem, hop);
 158	if (ret) {
 159		if (ret == -EMULTIHOP)
 160			return ret;
 161		goto out_err;
 162	}
 163
 164	ctx->bytes_moved += bo->base.size;
 165	return 0;
 166
 167out_err:
 168	if (!old_use_tt)
 169		ttm_bo_tt_destroy(bo);
 170
 171	return ret;
 172}
 173
 174/*
 175 * Call bo::reserved.
 176 * Will release GPU memory type usage on destruction.
 177 * This is the place to put in driver specific hooks to release
 178 * driver private resources.
 179 * Will release the bo::reserved lock.
 180 */
 181
 182static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
 183{
 184	if (bo->bdev->funcs->delete_mem_notify)
 185		bo->bdev->funcs->delete_mem_notify(bo);
 186
 187	ttm_bo_tt_destroy(bo);
 188	ttm_resource_free(bo, &bo->resource);
 189}
 190
 191static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 192{
 193	int r;
 194
 195	if (bo->base.resv == &bo->base._resv)
 196		return 0;
 197
 198	BUG_ON(!dma_resv_trylock(&bo->base._resv));
 199
 200	r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
 201	dma_resv_unlock(&bo->base._resv);
 202	if (r)
 203		return r;
 204
 205	if (bo->type != ttm_bo_type_sg) {
 206		/* This works because the BO is about to be destroyed and nobody
 207		 * reference it any more. The only tricky case is the trylock on
 208		 * the resv object while holding the lru_lock.
 209		 */
 210		spin_lock(&bo->bdev->lru_lock);
 211		bo->base.resv = &bo->base._resv;
 212		spin_unlock(&bo->bdev->lru_lock);
 213	}
 214
 215	return r;
 216}
 217
 218static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 219{
 220	struct dma_resv *resv = &bo->base._resv;
 221	struct dma_resv_iter cursor;
 222	struct dma_fence *fence;
 223
 224	dma_resv_iter_begin(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP);
 225	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 226		if (!fence->ops->signaled)
 227			dma_fence_enable_sw_signaling(fence);
 228	}
 229	dma_resv_iter_end(&cursor);
 230}
 231
 232/*
 233 * Block for the dma_resv object to become idle, lock the buffer and clean up
 234 * the resource and tt object.
 235 */
 236static void ttm_bo_delayed_delete(struct work_struct *work)
 237{
 238	struct ttm_buffer_object *bo;
 239
 240	bo = container_of(work, typeof(*bo), delayed_delete);
 241
 242	dma_resv_wait_timeout(&bo->base._resv, DMA_RESV_USAGE_BOOKKEEP, false,
 243			      MAX_SCHEDULE_TIMEOUT);
 244	dma_resv_lock(bo->base.resv, NULL);
 245	ttm_bo_cleanup_memtype_use(bo);
 246	dma_resv_unlock(bo->base.resv);
 247	ttm_bo_put(bo);
 248}
 249
 250static void ttm_bo_release(struct kref *kref)
 251{
 252	struct ttm_buffer_object *bo =
 253	    container_of(kref, struct ttm_buffer_object, kref);
 254	struct ttm_device *bdev = bo->bdev;
 255	int ret;
 256
 257	WARN_ON_ONCE(bo->pin_count);
 258	WARN_ON_ONCE(bo->bulk_move);
 259
 260	if (!bo->deleted) {
 261		ret = ttm_bo_individualize_resv(bo);
 262		if (ret) {
 263			/* Last resort, if we fail to allocate memory for the
 264			 * fences block for the BO to become idle
 265			 */
 266			dma_resv_wait_timeout(bo->base.resv,
 267					      DMA_RESV_USAGE_BOOKKEEP, false,
 268					      30 * HZ);
 269		}
 270
 271		if (bo->bdev->funcs->release_notify)
 272			bo->bdev->funcs->release_notify(bo);
 273
 274		drm_vma_offset_remove(bdev->vma_manager, &bo->base.vma_node);
 275		ttm_mem_io_free(bdev, bo->resource);
 276
 277		if (!dma_resv_test_signaled(&bo->base._resv,
 278					    DMA_RESV_USAGE_BOOKKEEP) ||
 279		    (want_init_on_free() && (bo->ttm != NULL)) ||
 280		    bo->type == ttm_bo_type_sg ||
 281		    !dma_resv_trylock(bo->base.resv)) {
 282			/* The BO is not idle, resurrect it for delayed destroy */
 283			ttm_bo_flush_all_fences(bo);
 284			bo->deleted = true;
 285
 286			spin_lock(&bo->bdev->lru_lock);
 287
 288			/*
 289			 * Make pinned bos immediately available to
 290			 * shrinkers, now that they are queued for
 291			 * destruction.
 292			 *
 293			 * FIXME: QXL is triggering this. Can be removed when the
 294			 * driver is fixed.
 295			 */
 296			if (bo->pin_count) {
 297				bo->pin_count = 0;
 298				ttm_resource_move_to_lru_tail(bo->resource);
 299			}
 300
 301			kref_init(&bo->kref);
 302			spin_unlock(&bo->bdev->lru_lock);
 303
 304			INIT_WORK(&bo->delayed_delete, ttm_bo_delayed_delete);
 305
 306			/* Schedule the worker on the closest NUMA node. This
 307			 * improves performance since system memory might be
 308			 * cleared on free and that is best done on a CPU core
 309			 * close to it.
 310			 */
 311			queue_work_node(bdev->pool.nid, bdev->wq, &bo->delayed_delete);
 312			return;
 313		}
 314
 315		ttm_bo_cleanup_memtype_use(bo);
 316		dma_resv_unlock(bo->base.resv);
 317	}
 318
 319	atomic_dec(&ttm_glob.bo_count);
 320	bo->destroy(bo);
 321}
 322
 323/* TODO: remove! */
 324void ttm_bo_put(struct ttm_buffer_object *bo)
 325{
 326	kref_put(&bo->kref, ttm_bo_release);
 327}
 328
 329void ttm_bo_fini(struct ttm_buffer_object *bo)
 330{
 331	ttm_bo_put(bo);
 332}
 333EXPORT_SYMBOL(ttm_bo_fini);
 334
 335static int ttm_bo_bounce_temp_buffer(struct ttm_buffer_object *bo,
 336				     struct ttm_operation_ctx *ctx,
 337				     struct ttm_place *hop)
 338{
 339	struct ttm_placement hop_placement;
 340	struct ttm_resource *hop_mem;
 341	int ret;
 342
 343	hop_placement.num_placement = 1;
 344	hop_placement.placement = hop;
 345
 346	/* find space in the bounce domain */
 347	ret = ttm_bo_mem_space(bo, &hop_placement, &hop_mem, ctx);
 348	if (ret)
 349		return ret;
 350	/* move to the bounce domain */
 351	ret = ttm_bo_handle_move_mem(bo, hop_mem, false, ctx, NULL);
 352	if (ret) {
 353		ttm_resource_free(bo, &hop_mem);
 354		return ret;
 355	}
 356	return 0;
 357}
 358
 359static int ttm_bo_evict(struct ttm_buffer_object *bo,
 360			struct ttm_operation_ctx *ctx)
 361{
 362	struct ttm_device *bdev = bo->bdev;
 363	struct ttm_resource *evict_mem;
 364	struct ttm_placement placement;
 365	struct ttm_place hop;
 366	int ret = 0;
 367
 368	memset(&hop, 0, sizeof(hop));
 369
 370	dma_resv_assert_held(bo->base.resv);
 371
 372	placement.num_placement = 0;
 373	bdev->funcs->evict_flags(bo, &placement);
 374
 375	if (!placement.num_placement) {
 376		ret = ttm_bo_wait_ctx(bo, ctx);
 377		if (ret)
 378			return ret;
 379
 380		/*
 381		 * Since we've already synced, this frees backing store
 382		 * immediately.
 383		 */
 384		return ttm_bo_pipeline_gutting(bo);
 385	}
 386
 387	ret = ttm_bo_mem_space(bo, &placement, &evict_mem, ctx);
 388	if (ret) {
 389		if (ret != -ERESTARTSYS) {
 390			pr_err("Failed to find memory space for buffer 0x%p eviction\n",
 391			       bo);
 392			ttm_bo_mem_space_debug(bo, &placement);
 393		}
 394		goto out;
 395	}
 396
 397	do {
 398		ret = ttm_bo_handle_move_mem(bo, evict_mem, true, ctx, &hop);
 399		if (ret != -EMULTIHOP)
 400			break;
 401
 402		ret = ttm_bo_bounce_temp_buffer(bo, ctx, &hop);
 403	} while (!ret);
 404
 405	if (ret) {
 406		ttm_resource_free(bo, &evict_mem);
 407		if (ret != -ERESTARTSYS && ret != -EINTR)
 408			pr_err("Buffer eviction failed\n");
 409	}
 410out:
 411	return ret;
 412}
 413
 414/**
 415 * ttm_bo_eviction_valuable
 416 *
 417 * @bo: The buffer object to evict
 418 * @place: the placement we need to make room for
 419 *
 420 * Check if it is valuable to evict the BO to make room for the given placement.
 421 */
 422bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 423			      const struct ttm_place *place)
 424{
 425	struct ttm_resource *res = bo->resource;
 426	struct ttm_device *bdev = bo->bdev;
 427
 428	dma_resv_assert_held(bo->base.resv);
 429	if (bo->resource->mem_type == TTM_PL_SYSTEM)
 430		return true;
 431
 432	/* Don't evict this BO if it's outside of the
 433	 * requested placement range
 434	 */
 435	return ttm_resource_intersects(bdev, res, place, bo->base.size);
 436}
 437EXPORT_SYMBOL(ttm_bo_eviction_valuable);
 438
 439/**
 440 * ttm_bo_evict_first() - Evict the first bo on the manager's LRU list.
 441 * @bdev: The ttm device.
 442 * @man: The manager whose bo to evict.
 443 * @ctx: The TTM operation ctx governing the eviction.
 444 *
 445 * Return: 0 if successful or the resource disappeared. Negative error code on error.
 446 */
 447int ttm_bo_evict_first(struct ttm_device *bdev, struct ttm_resource_manager *man,
 448		       struct ttm_operation_ctx *ctx)
 449{
 450	struct ttm_resource_cursor cursor;
 451	struct ttm_buffer_object *bo;
 452	struct ttm_resource *res;
 453	unsigned int mem_type;
 454	int ret = 0;
 455
 456	spin_lock(&bdev->lru_lock);
 457	ttm_resource_cursor_init(&cursor, man);
 458	res = ttm_resource_manager_first(&cursor);
 459	ttm_resource_cursor_fini(&cursor);
 460	if (!res) {
 461		ret = -ENOENT;
 462		goto out_no_ref;
 463	}
 464	bo = res->bo;
 465	if (!ttm_bo_get_unless_zero(bo))
 466		goto out_no_ref;
 467	mem_type = res->mem_type;
 468	spin_unlock(&bdev->lru_lock);
 469	ret = ttm_bo_reserve(bo, ctx->interruptible, ctx->no_wait_gpu, NULL);
 470	if (ret)
 471		goto out_no_lock;
 472	if (!bo->resource || bo->resource->mem_type != mem_type)
 473		goto out_bo_moved;
 474
 475	if (bo->deleted) {
 476		ret = ttm_bo_wait_ctx(bo, ctx);
 477		if (!ret)
 478			ttm_bo_cleanup_memtype_use(bo);
 479	} else {
 480		ret = ttm_bo_evict(bo, ctx);
 481	}
 482out_bo_moved:
 483	dma_resv_unlock(bo->base.resv);
 484out_no_lock:
 485	ttm_bo_put(bo);
 486	return ret;
 487
 488out_no_ref:
 489	spin_unlock(&bdev->lru_lock);
 490	return ret;
 491}
 492
 493/**
 494 * struct ttm_bo_evict_walk - Parameters for the evict walk.
 495 */
 496struct ttm_bo_evict_walk {
 497	/** @walk: The walk base parameters. */
 498	struct ttm_lru_walk walk;
 499	/** @place: The place passed to the resource allocation. */
 500	const struct ttm_place *place;
 501	/** @evictor: The buffer object we're trying to make room for. */
 502	struct ttm_buffer_object *evictor;
 503	/** @res: The allocated resource if any. */
 504	struct ttm_resource **res;
 505	/** @evicted: Number of successful evictions. */
 506	unsigned long evicted;
 507
 508	/** @limit_pool: Which pool limit we should test against */
 509	struct dmem_cgroup_pool_state *limit_pool;
 510	/** @try_low: Whether we should attempt to evict BO's with low watermark threshold */
 511	bool try_low;
 512	/** @hit_low: If we cannot evict a bo when @try_low is false (first pass) */
 513	bool hit_low;
 514};
 515
 516static s64 ttm_bo_evict_cb(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo)
 517{
 518	struct ttm_bo_evict_walk *evict_walk =
 519		container_of(walk, typeof(*evict_walk), walk);
 520	s64 lret;
 521
 522	if (!dmem_cgroup_state_evict_valuable(evict_walk->limit_pool, bo->resource->css,
 523					      evict_walk->try_low, &evict_walk->hit_low))
 524		return 0;
 525
 526	if (bo->pin_count || !bo->bdev->funcs->eviction_valuable(bo, evict_walk->place))
 527		return 0;
 528
 529	if (bo->deleted) {
 530		lret = ttm_bo_wait_ctx(bo, walk->arg.ctx);
 531		if (!lret)
 532			ttm_bo_cleanup_memtype_use(bo);
 533	} else {
 534		lret = ttm_bo_evict(bo, walk->arg.ctx);
 535	}
 536
 537	if (lret)
 538		goto out;
 539
 540	evict_walk->evicted++;
 541	if (evict_walk->res)
 542		lret = ttm_resource_alloc(evict_walk->evictor, evict_walk->place,
 543					  evict_walk->res, NULL);
 544	if (lret == 0)
 545		return 1;
 546out:
 547	/* Errors that should terminate the walk. */
 548	if (lret == -ENOSPC)
 549		return -EBUSY;
 550
 551	return lret;
 552}
 553
 554static const struct ttm_lru_walk_ops ttm_evict_walk_ops = {
 555	.process_bo = ttm_bo_evict_cb,
 556};
 557
 558static int ttm_bo_evict_alloc(struct ttm_device *bdev,
 559			      struct ttm_resource_manager *man,
 560			      const struct ttm_place *place,
 561			      struct ttm_buffer_object *evictor,
 562			      struct ttm_operation_ctx *ctx,
 563			      struct ww_acquire_ctx *ticket,
 564			      struct ttm_resource **res,
 565			      struct dmem_cgroup_pool_state *limit_pool)
 566{
 567	struct ttm_bo_evict_walk evict_walk = {
 568		.walk = {
 569			.ops = &ttm_evict_walk_ops,
 570			.arg = {
 571				.ctx = ctx,
 572				.ticket = ticket,
 573			}
 574		},
 575		.place = place,
 576		.evictor = evictor,
 577		.res = res,
 578		.limit_pool = limit_pool,
 579	};
 580	s64 lret;
 581
 582	evict_walk.walk.arg.trylock_only = true;
 583	lret = ttm_lru_walk_for_evict(&evict_walk.walk, bdev, man, 1);
 584
 585	/* One more attempt if we hit low limit? */
 586	if (!lret && evict_walk.hit_low) {
 587		evict_walk.try_low = true;
 588		lret = ttm_lru_walk_for_evict(&evict_walk.walk, bdev, man, 1);
 589	}
 590	if (lret || !ticket)
 591		goto out;
 592
 593	/* Reset low limit */
 594	evict_walk.try_low = evict_walk.hit_low = false;
 595	/* If ticket-locking, repeat while making progress. */
 596	evict_walk.walk.arg.trylock_only = false;
 597
 598retry:
 599	do {
 600		/* The walk may clear the evict_walk.walk.ticket field */
 601		evict_walk.walk.arg.ticket = ticket;
 602		evict_walk.evicted = 0;
 603		lret = ttm_lru_walk_for_evict(&evict_walk.walk, bdev, man, 1);
 604	} while (!lret && evict_walk.evicted);
 605
 606	/* We hit the low limit? Try once more */
 607	if (!lret && evict_walk.hit_low && !evict_walk.try_low) {
 608		evict_walk.try_low = true;
 609		goto retry;
 610	}
 611out:
 612	if (lret < 0)
 613		return lret;
 614	if (lret == 0)
 615		return -EBUSY;
 616	return 0;
 617}
 618
 619/**
 620 * ttm_bo_pin - Pin the buffer object.
 621 * @bo: The buffer object to pin
 622 *
 623 * Make sure the buffer is not evicted any more during memory pressure.
 624 * @bo must be unpinned again by calling ttm_bo_unpin().
 625 */
 626void ttm_bo_pin(struct ttm_buffer_object *bo)
 627{
 628	dma_resv_assert_held(bo->base.resv);
 629	WARN_ON_ONCE(!kref_read(&bo->kref));
 630	spin_lock(&bo->bdev->lru_lock);
 631	if (bo->resource)
 632		ttm_resource_del_bulk_move(bo->resource, bo);
 633	if (!bo->pin_count++ && bo->resource)
 634		ttm_resource_move_to_lru_tail(bo->resource);
 635	spin_unlock(&bo->bdev->lru_lock);
 636}
 637EXPORT_SYMBOL(ttm_bo_pin);
 638
 639/**
 640 * ttm_bo_unpin - Unpin the buffer object.
 641 * @bo: The buffer object to unpin
 642 *
 643 * Allows the buffer object to be evicted again during memory pressure.
 644 */
 645void ttm_bo_unpin(struct ttm_buffer_object *bo)
 646{
 647	dma_resv_assert_held(bo->base.resv);
 648	WARN_ON_ONCE(!kref_read(&bo->kref));
 649	if (WARN_ON_ONCE(!bo->pin_count))
 650		return;
 651
 652	spin_lock(&bo->bdev->lru_lock);
 653	if (!--bo->pin_count && bo->resource) {
 654		ttm_resource_add_bulk_move(bo->resource, bo);
 655		ttm_resource_move_to_lru_tail(bo->resource);
 656	}
 657	spin_unlock(&bo->bdev->lru_lock);
 658}
 659EXPORT_SYMBOL(ttm_bo_unpin);
 660
 661/*
 662 * Add the pipelined eviction fencesto the BO as kernel dependency and reserve new
 663 * fence slots.
 664 */
 665static int ttm_bo_add_pipelined_eviction_fences(struct ttm_buffer_object *bo,
 666						struct ttm_resource_manager *man,
 667						bool no_wait_gpu)
 668{
 669	struct dma_fence *fence;
 670	int i;
 671
 672	spin_lock(&man->eviction_lock);
 673	for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) {
 674		fence = man->eviction_fences[i];
 675		if (!fence)
 676			continue;
 677
 678		if (no_wait_gpu) {
 679			if (!dma_fence_is_signaled(fence)) {
 680				spin_unlock(&man->eviction_lock);
 681				return -EBUSY;
 682			}
 683		} else {
 684			dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL);
 685		}
 686	}
 687	spin_unlock(&man->eviction_lock);
 688
 689	/* TODO: this call should be removed. */
 690	return dma_resv_reserve_fences(bo->base.resv, 1);
 691}
 692
 693/**
 694 * ttm_bo_alloc_resource - Allocate backing store for a BO
 695 *
 696 * @bo: Pointer to a struct ttm_buffer_object of which we want a resource for
 697 * @placement: Proposed new placement for the buffer object
 698 * @ctx: if and how to sleep, lock buffers and alloc memory
 699 * @force_space: If we should evict buffers to force space
 700 * @res: The resulting struct ttm_resource.
 701 *
 702 * Allocates a resource for the buffer object pointed to by @bo, using the
 703 * placement flags in @placement, potentially evicting other buffer objects when
 704 * @force_space is true.
 705 * This function may sleep while waiting for resources to become available.
 706 * Returns:
 707 * -EBUSY: No space available (only if no_wait == true).
 708 * -ENOSPC: Could not allocate space for the buffer object, either due to
 709 * fragmentation or concurrent allocators.
 710 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
 711 */
 712static int ttm_bo_alloc_resource(struct ttm_buffer_object *bo,
 713				 struct ttm_placement *placement,
 714				 struct ttm_operation_ctx *ctx,
 715				 bool force_space,
 716				 struct ttm_resource **res)
 717{
 718	struct ttm_device *bdev = bo->bdev;
 719	struct ww_acquire_ctx *ticket;
 720	int i, ret;
 721
 722	ticket = dma_resv_locking_ctx(bo->base.resv);
 723	ret = dma_resv_reserve_fences(bo->base.resv, TTM_NUM_MOVE_FENCES);
 724	if (unlikely(ret))
 725		return ret;
 726
 727	for (i = 0; i < placement->num_placement; ++i) {
 728		const struct ttm_place *place = &placement->placement[i];
 729		struct dmem_cgroup_pool_state *limit_pool = NULL;
 730		struct ttm_resource_manager *man;
 731		bool may_evict;
 732
 733		man = ttm_manager_type(bdev, place->mem_type);
 734		if (!man || !ttm_resource_manager_used(man))
 735			continue;
 736
 737		if (place->flags & (force_space ? TTM_PL_FLAG_DESIRED :
 738				    TTM_PL_FLAG_FALLBACK))
 739			continue;
 740
 741		may_evict = (force_space && place->mem_type != TTM_PL_SYSTEM);
 742		ret = ttm_resource_alloc(bo, place, res, force_space ? &limit_pool : NULL);
 743		if (ret) {
 744			if (ret != -ENOSPC && ret != -EAGAIN) {
 745				dmem_cgroup_pool_state_put(limit_pool);
 746				return ret;
 747			}
 748			if (!may_evict) {
 749				dmem_cgroup_pool_state_put(limit_pool);
 750				continue;
 751			}
 752
 753			ret = ttm_bo_evict_alloc(bdev, man, place, bo, ctx,
 754						 ticket, res, limit_pool);
 755			dmem_cgroup_pool_state_put(limit_pool);
 756			if (ret == -EBUSY)
 757				continue;
 758			if (ret)
 759				return ret;
 760		}
 761
 762		ret = ttm_bo_add_pipelined_eviction_fences(bo, man, ctx->no_wait_gpu);
 763		if (unlikely(ret)) {
 764			ttm_resource_free(bo, res);
 765			if (ret == -EBUSY)
 766				continue;
 767
 768			return ret;
 769		}
 770		return 0;
 771	}
 772
 773	return -ENOSPC;
 774}
 775
 776/*
 777 * ttm_bo_mem_space - Wrapper around ttm_bo_alloc_resource
 778 *
 779 * @bo: Pointer to a struct ttm_buffer_object of which we want a resource for
 780 * @placement: Proposed new placement for the buffer object
 781 * @res: The resulting struct ttm_resource.
 782 * @ctx: if and how to sleep, lock buffers and alloc memory
 783 *
 784 * Tries both idle allocation and forcefully eviction of buffers. See
 785 * ttm_bo_alloc_resource for details.
 786 */
 787int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 788		     struct ttm_placement *placement,
 789		     struct ttm_resource **res,
 790		     struct ttm_operation_ctx *ctx)
 791{
 792	bool force_space = false;
 793	int ret;
 794
 795	do {
 796		ret = ttm_bo_alloc_resource(bo, placement, ctx,
 797					    force_space, res);
 798		force_space = !force_space;
 799	} while (ret == -ENOSPC && force_space);
 800
 801	return ret;
 802}
 803EXPORT_SYMBOL(ttm_bo_mem_space);
 804
 805/**
 806 * ttm_bo_validate
 807 *
 808 * @bo: The buffer object.
 809 * @placement: Proposed placement for the buffer object.
 810 * @ctx: validation parameters.
 811 *
 812 * Changes placement and caching policy of the buffer object
 813 * according proposed placement.
 814 * Returns
 815 * -EINVAL on invalid proposed placement.
 816 * -ENOMEM on out-of-memory condition.
 817 * -EBUSY if no_wait is true and buffer busy.
 818 * -ERESTARTSYS if interrupted by a signal.
 819 */
 820int ttm_bo_validate(struct ttm_buffer_object *bo,
 821		    struct ttm_placement *placement,
 822		    struct ttm_operation_ctx *ctx)
 823{
 824	struct ttm_resource *res;
 825	struct ttm_place hop;
 826	bool force_space;
 827	int ret;
 828
 829	dma_resv_assert_held(bo->base.resv);
 830
 831	/*
 832	 * Remove the backing store if no placement is given.
 833	 */
 834	if (!placement->num_placement)
 835		return ttm_bo_pipeline_gutting(bo);
 836
 837	force_space = false;
 838	do {
 839		/* Check whether we need to move buffer. */
 840		if (bo->resource &&
 841		    ttm_resource_compatible(bo->resource, placement,
 842					    force_space))
 843			return 0;
 844
 845		/* Moving of pinned BOs is forbidden */
 846		if (bo->pin_count)
 847			return -EINVAL;
 848
 849		/*
 850		 * Determine where to move the buffer.
 851		 *
 852		 * If driver determines move is going to need
 853		 * an extra step then it will return -EMULTIHOP
 854		 * and the buffer will be moved to the temporary
 855		 * stop and the driver will be called to make
 856		 * the second hop.
 857		 */
 858		ret = ttm_bo_alloc_resource(bo, placement, ctx, force_space,
 859					    &res);
 860		force_space = !force_space;
 861		if (ret == -ENOSPC)
 862			continue;
 863		if (ret)
 864			return ret;
 865
 866bounce:
 867		ret = ttm_bo_handle_move_mem(bo, res, false, ctx, &hop);
 868		if (ret == -EMULTIHOP) {
 869			ret = ttm_bo_bounce_temp_buffer(bo, ctx, &hop);
 870			/* try and move to final place now. */
 871			if (!ret)
 872				goto bounce;
 873		}
 874		if (ret) {
 875			ttm_resource_free(bo, &res);
 876			return ret;
 877		}
 878
 879	} while (ret && force_space);
 880
 881	/* For backward compatibility with userspace */
 882	if (ret == -ENOSPC)
 883		return bo->bdev->alloc_flags & TTM_ALLOCATION_PROPAGATE_ENOSPC ?
 884		       ret : -ENOMEM;
 885
 886	/*
 887	 * We might need to add a TTM.
 888	 */
 889	if (!bo->resource || bo->resource->mem_type == TTM_PL_SYSTEM) {
 890		ret = ttm_tt_create(bo, true);
 891		if (ret)
 892			return ret;
 893	}
 894	return 0;
 895}
 896EXPORT_SYMBOL(ttm_bo_validate);
 897
 898/**
 899 * ttm_bo_init_reserved
 900 *
 901 * @bdev: Pointer to a ttm_device struct.
 902 * @bo: Pointer to a ttm_buffer_object to be initialized.
 903 * @type: Requested type of buffer object.
 904 * @placement: Initial placement for buffer object.
 905 * @alignment: Data alignment in pages.
 906 * @ctx: TTM operation context for memory allocation.
 907 * @sg: Scatter-gather table.
 908 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
 909 * @destroy: Destroy function. Use NULL for kfree().
 910 *
 911 * This function initializes a pre-allocated struct ttm_buffer_object.
 912 * As this object may be part of a larger structure, this function,
 913 * together with the @destroy function, enables driver-specific objects
 914 * derived from a ttm_buffer_object.
 915 *
 916 * On successful return, the caller owns an object kref to @bo. The kref and
 917 * list_kref are usually set to 1, but note that in some situations, other
 918 * tasks may already be holding references to @bo as well.
 919 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
 920 * and it is the caller's responsibility to call ttm_bo_unreserve.
 921 *
 922 * If a failure occurs, the function will call the @destroy function. Thus,
 923 * after a failure, dereferencing @bo is illegal and will likely cause memory
 924 * corruption.
 925 *
 926 * Returns
 927 * -ENOMEM: Out of memory.
 928 * -EINVAL: Invalid placement flags.
 929 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 930 */
 931int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
 932			 enum ttm_bo_type type, struct ttm_placement *placement,
 933			 uint32_t alignment, struct ttm_operation_ctx *ctx,
 934			 struct sg_table *sg, struct dma_resv *resv,
 935			 void (*destroy) (struct ttm_buffer_object *))
 936{
 937	int ret;
 938
 939	kref_init(&bo->kref);
 940	bo->bdev = bdev;
 941	bo->type = type;
 942	bo->page_alignment = alignment;
 943	bo->destroy = destroy;
 944	bo->pin_count = 0;
 945	bo->sg = sg;
 946	bo->bulk_move = NULL;
 947	if (resv)
 948		bo->base.resv = resv;
 949	else
 950		bo->base.resv = &bo->base._resv;
 951	atomic_inc(&ttm_glob.bo_count);
 952
 953	/*
 954	 * For ttm_bo_type_device buffers, allocate
 955	 * address space from the device.
 956	 */
 957	if (bo->type == ttm_bo_type_device || bo->type == ttm_bo_type_sg) {
 958		ret = drm_vma_offset_add(bdev->vma_manager, &bo->base.vma_node,
 959					 PFN_UP(bo->base.size));
 960		if (ret)
 961			goto err_put;
 962	}
 963
 964	/* passed reservation objects should already be locked,
 965	 * since otherwise lockdep will be angered in radeon.
 966	 */
 967	if (!resv)
 968		WARN_ON(!dma_resv_trylock(bo->base.resv));
 969	else
 970		dma_resv_assert_held(resv);
 971
 972	ret = ttm_bo_validate(bo, placement, ctx);
 973	if (unlikely(ret))
 974		goto err_unlock;
 975
 976	return 0;
 977
 978err_unlock:
 979	if (!resv)
 980		dma_resv_unlock(bo->base.resv);
 981
 982err_put:
 983	ttm_bo_put(bo);
 984	return ret;
 985}
 986EXPORT_SYMBOL(ttm_bo_init_reserved);
 987
 988/**
 989 * ttm_bo_init_validate
 990 *
 991 * @bdev: Pointer to a ttm_device struct.
 992 * @bo: Pointer to a ttm_buffer_object to be initialized.
 993 * @type: Requested type of buffer object.
 994 * @placement: Initial placement for buffer object.
 995 * @alignment: Data alignment in pages.
 996 * @interruptible: If needing to sleep to wait for GPU resources,
 997 * sleep interruptible.
 998 * pinned in physical memory. If this behaviour is not desired, this member
 999 * holds a pointer to a persistent shmem object. Typically, this would
1000 * point to the shmem object backing a GEM object if TTM is used to back a
1001 * GEM user interface.
1002 * @sg: Scatter-gather table.
1003 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
1004 * @destroy: Destroy function. Use NULL for kfree().
1005 *
1006 * This function initializes a pre-allocated struct ttm_buffer_object.
1007 * As this object may be part of a larger structure, this function,
1008 * together with the @destroy function,
1009 * enables driver-specific objects derived from a ttm_buffer_object.
1010 *
1011 * On successful return, the caller owns an object kref to @bo. The kref and
1012 * list_kref are usually set to 1, but note that in some situations, other
1013 * tasks may already be holding references to @bo as well.
1014 *
1015 * If a failure occurs, the function will call the @destroy function, Thus,
1016 * after a failure, dereferencing @bo is illegal and will likely cause memory
1017 * corruption.
1018 *
1019 * Returns
1020 * -ENOMEM: Out of memory.
1021 * -EINVAL: Invalid placement flags.
1022 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
1023 */
1024int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
1025			 enum ttm_bo_type type, struct ttm_placement *placement,
1026			 uint32_t alignment, bool interruptible,
1027			 struct sg_table *sg, struct dma_resv *resv,
1028			 void (*destroy) (struct ttm_buffer_object *))
1029{
1030	struct ttm_operation_ctx ctx = { interruptible, false };
1031	int ret;
1032
1033	ret = ttm_bo_init_reserved(bdev, bo, type, placement, alignment, &ctx,
1034				   sg, resv, destroy);
1035	if (ret)
1036		return ret;
1037
1038	if (!resv)
1039		ttm_bo_unreserve(bo);
1040
1041	return 0;
1042}
1043EXPORT_SYMBOL(ttm_bo_init_validate);
1044
1045/*
1046 * buffer object vm functions.
1047 */
1048
1049/**
1050 * ttm_bo_unmap_virtual
1051 *
1052 * @bo: tear down the virtual mappings for this BO
1053 */
1054void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
1055{
1056	struct ttm_device *bdev = bo->bdev;
1057
1058	drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
1059	ttm_mem_io_free(bdev, bo->resource);
1060}
1061EXPORT_SYMBOL(ttm_bo_unmap_virtual);
1062
1063/**
1064 * ttm_bo_wait_ctx - wait for buffer idle.
1065 *
1066 * @bo:  The buffer object.
1067 * @ctx: defines how to wait
1068 *
1069 * Waits for the buffer to be idle. Used timeout depends on the context.
1070 * Returns -EBUSY if wait timed outt, -ERESTARTSYS if interrupted by a signal or
1071 * zero on success.
1072 */
1073int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx)
1074{
1075	long ret;
1076
1077	if (ctx->no_wait_gpu) {
1078		if (dma_resv_test_signaled(bo->base.resv,
1079					   DMA_RESV_USAGE_BOOKKEEP))
1080			return 0;
1081		else
1082			return -EBUSY;
1083	}
1084
1085	ret = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
1086				    ctx->interruptible, 15 * HZ);
1087	if (unlikely(ret < 0))
1088		return ret;
1089	if (unlikely(ret == 0))
1090		return -EBUSY;
1091	return 0;
1092}
1093EXPORT_SYMBOL(ttm_bo_wait_ctx);
1094
1095/**
1096 * struct ttm_bo_swapout_walk - Parameters for the swapout walk
1097 */
1098struct ttm_bo_swapout_walk {
1099	/** @walk: The walk base parameters. */
1100	struct ttm_lru_walk walk;
1101	/** @gfp_flags: The gfp flags to use for ttm_tt_swapout() */
1102	gfp_t gfp_flags;
1103	/** @hit_low: Whether we should attempt to swap BO's with low watermark threshold */
1104	/** @evict_low: If we cannot swap a bo when @try_low is false (first pass) */
1105	bool hit_low, evict_low;
1106};
1107
1108static s64
1109ttm_bo_swapout_cb(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo)
1110{
1111	struct ttm_place place = {.mem_type = bo->resource->mem_type};
1112	struct ttm_bo_swapout_walk *swapout_walk =
1113		container_of(walk, typeof(*swapout_walk), walk);
1114	struct ttm_operation_ctx *ctx = walk->arg.ctx;
1115	s64 ret;
1116
1117	/*
1118	 * While the bo may already reside in SYSTEM placement, set
1119	 * SYSTEM as new placement to cover also the move further below.
1120	 * The driver may use the fact that we're moving from SYSTEM
1121	 * as an indication that we're about to swap out.
1122	 */
1123	if (bo->pin_count || !bo->bdev->funcs->eviction_valuable(bo, &place)) {
1124		ret = -EBUSY;
1125		goto out;
1126	}
1127
1128	if (!bo->ttm || !ttm_tt_is_populated(bo->ttm) ||
1129	    bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL ||
1130	    bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED) {
1131		ret = -EBUSY;
1132		goto out;
1133	}
1134
1135	if (bo->deleted) {
1136		pgoff_t num_pages = bo->ttm->num_pages;
1137
1138		ret = ttm_bo_wait_ctx(bo, ctx);
1139		if (ret)
1140			goto out;
1141
1142		ttm_bo_cleanup_memtype_use(bo);
1143		ret = num_pages;
1144		goto out;
1145	}
1146
1147	/*
1148	 * Move to system cached
1149	 */
1150	if (bo->resource->mem_type != TTM_PL_SYSTEM) {
1151		struct ttm_resource *evict_mem;
1152		struct ttm_place hop;
1153
1154		memset(&hop, 0, sizeof(hop));
1155		place.mem_type = TTM_PL_SYSTEM;
1156		ret = ttm_resource_alloc(bo, &place, &evict_mem, NULL);
1157		if (ret)
1158			goto out;
1159
1160		ret = ttm_bo_handle_move_mem(bo, evict_mem, true, ctx, &hop);
1161		if (ret) {
1162			WARN(ret == -EMULTIHOP,
1163			     "Unexpected multihop in swapout - likely driver bug.\n");
1164			ttm_resource_free(bo, &evict_mem);
1165			goto out;
1166		}
1167	}
1168
1169	/*
1170	 * Make sure BO is idle.
1171	 */
1172	ret = ttm_bo_wait_ctx(bo, ctx);
1173	if (ret)
1174		goto out;
1175
1176	ttm_bo_unmap_virtual(bo);
1177	if (bo->bdev->funcs->swap_notify)
1178		bo->bdev->funcs->swap_notify(bo);
1179
1180	if (ttm_tt_is_populated(bo->ttm)) {
1181		spin_lock(&bo->bdev->lru_lock);
1182		ttm_resource_del_bulk_move(bo->resource, bo);
1183		spin_unlock(&bo->bdev->lru_lock);
1184
1185		ret = ttm_tt_swapout(bo->bdev, bo->ttm, swapout_walk->gfp_flags);
1186
1187		spin_lock(&bo->bdev->lru_lock);
1188		if (ret)
1189			ttm_resource_add_bulk_move(bo->resource, bo);
1190		ttm_resource_move_to_lru_tail(bo->resource);
1191		spin_unlock(&bo->bdev->lru_lock);
1192	}
1193
1194out:
1195	/* Consider -ENOMEM and -ENOSPC non-fatal. */
1196	if (ret == -ENOMEM || ret == -ENOSPC)
1197		ret = -EBUSY;
1198
1199	return ret;
1200}
1201
1202const struct ttm_lru_walk_ops ttm_swap_ops = {
1203	.process_bo = ttm_bo_swapout_cb,
1204};
1205
1206/**
1207 * ttm_bo_swapout() - Swap out buffer objects on the LRU list to shmem.
1208 * @bdev: The ttm device.
1209 * @ctx: The ttm_operation_ctx governing the swapout operation.
1210 * @man: The resource manager whose resources / buffer objects are
1211 * goint to be swapped out.
1212 * @gfp_flags: The gfp flags used for shmem page allocations.
1213 * @target: The desired number of bytes to swap out.
1214 *
1215 * Return: The number of bytes actually swapped out, or negative error code
1216 * on error.
1217 */
1218s64 ttm_bo_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
1219		   struct ttm_resource_manager *man, gfp_t gfp_flags,
1220		   s64 target)
1221{
1222	struct ttm_bo_swapout_walk swapout_walk = {
1223		.walk = {
1224			.ops = &ttm_swap_ops,
1225			.arg = {
1226				.ctx = ctx,
1227				.trylock_only = true,
1228			},
1229		},
1230		.gfp_flags = gfp_flags,
1231	};
1232
1233	return ttm_lru_walk_for_evict(&swapout_walk.walk, bdev, man, target);
1234}
1235
1236void ttm_bo_tt_destroy(struct ttm_buffer_object *bo)
1237{
1238	if (bo->ttm == NULL)
1239		return;
1240
1241	ttm_tt_unpopulate(bo->bdev, bo->ttm);
1242	ttm_tt_destroy(bo->bdev, bo->ttm);
1243	bo->ttm = NULL;
1244}
1245
1246/**
1247 * ttm_bo_populate() - Ensure that a buffer object has backing pages
1248 * @bo: The buffer object
1249 * @ctx: The ttm_operation_ctx governing the operation.
1250 *
1251 * For buffer objects in a memory type whose manager uses
1252 * struct ttm_tt for backing pages, ensure those backing pages
1253 * are present and with valid content. The bo's resource is also
1254 * placed on the correct LRU list if it was previously swapped
1255 * out.
1256 *
1257 * Return: 0 if successful, negative error code on failure.
1258 * Note: May return -EINTR or -ERESTARTSYS if @ctx::interruptible
1259 * is set to true.
1260 */
1261int ttm_bo_populate(struct ttm_buffer_object *bo,
1262		    struct ttm_operation_ctx *ctx)
1263{
1264	struct ttm_tt *tt = bo->ttm;
1265	bool swapped;
1266	int ret;
1267
1268	dma_resv_assert_held(bo->base.resv);
1269
1270	if (!tt)
1271		return 0;
1272
1273	swapped = ttm_tt_is_swapped(tt);
1274	ret = ttm_tt_populate(bo->bdev, tt, ctx);
1275	if (ret)
1276		return ret;
1277
1278	if (swapped && !ttm_tt_is_swapped(tt) && !bo->pin_count &&
1279	    bo->resource) {
1280		spin_lock(&bo->bdev->lru_lock);
1281		ttm_resource_add_bulk_move(bo->resource, bo);
1282		ttm_resource_move_to_lru_tail(bo->resource);
1283		spin_unlock(&bo->bdev->lru_lock);
1284	}
1285
1286	return 0;
1287}
1288EXPORT_SYMBOL(ttm_bo_populate);
1289
1290int ttm_bo_setup_export(struct ttm_buffer_object *bo,
1291			struct ttm_operation_ctx *ctx)
1292{
1293	int ret;
1294
1295	ret = ttm_bo_reserve(bo, false, false, NULL);
1296	if (ret != 0)
1297		return ret;
1298
1299	ret = ttm_bo_populate(bo, ctx);
1300	ttm_bo_unreserve(bo);
1301	return ret;
1302}
1303EXPORT_SYMBOL(ttm_bo_setup_export);