vmwgfx_validation.c

  1// SPDX-License-Identifier: GPL-2.0 OR MIT
  2/**************************************************************************
  3 *
  4 * Copyright © 2018 - 2023 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#include "vmwgfx_bo.h"
 29#include "vmwgfx_drv.h"
 30#include "vmwgfx_resource_priv.h"
 31#include "vmwgfx_validation.h"
 32
 33#include <linux/slab.h>
 34
 35/**
 36 * struct vmw_validation_bo_node - Buffer object validation metadata.
 37 * @base: Metadata used for TTM reservation- and validation.
 38 * @hash: A hash entry used for the duplicate detection hash table.
 39 * @coherent_count: If switching backup buffers, number of new coherent
 40 * resources that will have this buffer as a backup buffer.
 41 *
 42 * Bit fields are used since these structures are allocated and freed in
 43 * large numbers and space conservation is desired.
 44 */
 45struct vmw_validation_bo_node {
 46	struct ttm_validate_buffer base;
 47	struct vmwgfx_hash_item hash;
 48	unsigned int coherent_count;
 49};
 50/**
 51 * struct vmw_validation_res_node - Resource validation metadata.
 52 * @head: List head for the resource validation list.
 53 * @hash: A hash entry used for the duplicate detection hash table.
 54 * @res: Reference counted resource pointer.
 55 * @new_guest_memory_bo: Non ref-counted pointer to new guest memory buffer
 56 * to be assigned to a resource.
 57 * @new_guest_memory_offset: Offset into the new backup mob for resources
 58 * that can share MOBs.
 59 * @no_buffer_needed: Kernel does not need to allocate a MOB during validation,
 60 * the command stream provides a mob bind operation.
 61 * @switching_guest_memory_bo: The validation process is switching backup MOB.
 62 * @first_usage: True iff the resource has been seen only once in the current
 63 * validation batch.
 64 * @reserved: Whether the resource is currently reserved by this process.
 65 * @dirty_set: Change dirty status of the resource.
 66 * @dirty: Dirty information VMW_RES_DIRTY_XX.
 67 * @private: Optionally additional memory for caller-private data.
 68 *
 69 * Bit fields are used since these structures are allocated and freed in
 70 * large numbers and space conservation is desired.
 71 */
 72struct vmw_validation_res_node {
 73	struct list_head head;
 74	struct vmwgfx_hash_item hash;
 75	struct vmw_resource *res;
 76	struct vmw_bo *new_guest_memory_bo;
 77	unsigned long new_guest_memory_offset;
 78	u32 no_buffer_needed : 1;
 79	u32 switching_guest_memory_bo : 1;
 80	u32 first_usage : 1;
 81	u32 reserved : 1;
 82	u32 dirty : 1;
 83	u32 dirty_set : 1;
 84	unsigned long private[];
 85};
 86
 87/**
 88 * vmw_validation_mem_alloc - Allocate kernel memory from the validation
 89 * context based allocator
 90 * @ctx: The validation context
 91 * @size: The number of bytes to allocated.
 92 *
 93 * The memory allocated may not exceed PAGE_SIZE, and the returned
 94 * address is aligned to sizeof(long). All memory allocated this way is
 95 * reclaimed after validation when calling any of the exported functions:
 96 * vmw_validation_unref_lists()
 97 * vmw_validation_revert()
 98 * vmw_validation_done()
 99 *
100 * Return: Pointer to the allocated memory on success. NULL on failure.
101 */
102void *vmw_validation_mem_alloc(struct vmw_validation_context *ctx,
103			       unsigned int size)
104{
105	void *addr;
106
107	size = vmw_validation_align(size);
108	if (size > PAGE_SIZE)
109		return NULL;
110
111	if (ctx->mem_size_left < size) {
112		struct page *page = alloc_page(GFP_KERNEL | __GFP_ZERO);
113		if (!page)
114			return NULL;
115
116		list_add_tail(&page->lru, &ctx->page_list);
117		ctx->page_address = page_address(page);
118		ctx->mem_size_left = PAGE_SIZE;
119	}
120
121	addr = (void *) (ctx->page_address + (PAGE_SIZE - ctx->mem_size_left));
122	ctx->mem_size_left -= size;
123
124	return addr;
125}
126
127/**
128 * vmw_validation_mem_free - Free all memory allocated using
129 * vmw_validation_mem_alloc()
130 * @ctx: The validation context
131 *
132 * All memory previously allocated for this context using
133 * vmw_validation_mem_alloc() is freed.
134 */
135static void vmw_validation_mem_free(struct vmw_validation_context *ctx)
136{
137	struct page *entry, *next;
138
139	list_for_each_entry_safe(entry, next, &ctx->page_list, lru) {
140		list_del_init(&entry->lru);
141		__free_page(entry);
142	}
143
144	ctx->mem_size_left = 0;
145}
146
147/**
148 * vmw_validation_find_bo_dup - Find a duplicate buffer object entry in the
149 * validation context's lists.
150 * @ctx: The validation context to search.
151 * @vbo: The buffer object to search for.
152 *
153 * Return: Pointer to the struct vmw_validation_bo_node referencing the
154 * duplicate, or NULL if none found.
155 */
156static struct vmw_validation_bo_node *
157vmw_validation_find_bo_dup(struct vmw_validation_context *ctx,
158			   struct vmw_bo *vbo)
159{
160	struct  vmw_validation_bo_node *bo_node = NULL;
161
162	if (!ctx->merge_dups)
163		return NULL;
164
165	if (ctx->sw_context) {
166		struct vmwgfx_hash_item *hash;
167		unsigned long key = (unsigned long) vbo;
168
169		hash_for_each_possible_rcu(ctx->sw_context->res_ht, hash, head, key) {
170			if (hash->key == key) {
171				bo_node = container_of(hash, typeof(*bo_node), hash);
172				break;
173			}
174		}
175	} else {
176		struct  vmw_validation_bo_node *entry;
177
178		list_for_each_entry(entry, &ctx->bo_list, base.head) {
179			if (entry->base.bo == &vbo->tbo) {
180				bo_node = entry;
181				break;
182			}
183		}
184	}
185
186	return bo_node;
187}
188
189/**
190 * vmw_validation_find_res_dup - Find a duplicate resource entry in the
191 * validation context's lists.
192 * @ctx: The validation context to search.
193 * @res: Reference counted resource pointer.
194 *
195 * Return: Pointer to the struct vmw_validation_bo_node referencing the
196 * duplicate, or NULL if none found.
197 */
198static struct vmw_validation_res_node *
199vmw_validation_find_res_dup(struct vmw_validation_context *ctx,
200			    struct vmw_resource *res)
201{
202	struct  vmw_validation_res_node *res_node = NULL;
203
204	if (!ctx->merge_dups)
205		return NULL;
206
207	if (ctx->sw_context) {
208		struct vmwgfx_hash_item *hash;
209		unsigned long key = (unsigned long) res;
210
211		hash_for_each_possible_rcu(ctx->sw_context->res_ht, hash, head, key) {
212			if (hash->key == key) {
213				res_node = container_of(hash, typeof(*res_node), hash);
214				break;
215			}
216		}
217	} else {
218		struct  vmw_validation_res_node *entry;
219
220		list_for_each_entry(entry, &ctx->resource_ctx_list, head) {
221			if (entry->res == res) {
222				res_node = entry;
223				goto out;
224			}
225		}
226
227		list_for_each_entry(entry, &ctx->resource_list, head) {
228			if (entry->res == res) {
229				res_node = entry;
230				break;
231			}
232		}
233
234	}
235out:
236	return res_node;
237}
238
239/**
240 * vmw_validation_add_bo - Add a buffer object to the validation context.
241 * @ctx: The validation context.
242 * @vbo: The buffer object.
243 *
244 * Return: Zero on success, negative error code otherwise.
245 */
246int vmw_validation_add_bo(struct vmw_validation_context *ctx,
247			  struct vmw_bo *vbo)
248{
249	struct vmw_validation_bo_node *bo_node;
250
251	bo_node = vmw_validation_find_bo_dup(ctx, vbo);
252	if (!bo_node) {
253		struct ttm_validate_buffer *val_buf;
254
255		bo_node = vmw_validation_mem_alloc(ctx, sizeof(*bo_node));
256		if (!bo_node)
257			return -ENOMEM;
258
259		if (ctx->sw_context) {
260			bo_node->hash.key = (unsigned long) vbo;
261			hash_add_rcu(ctx->sw_context->res_ht, &bo_node->hash.head,
262				bo_node->hash.key);
263		}
264		val_buf = &bo_node->base;
265		vmw_bo_reference(vbo);
266		val_buf->bo = &vbo->tbo;
267		val_buf->num_shared = 0;
268		list_add_tail(&val_buf->head, &ctx->bo_list);
269	}
270
271	return 0;
272}
273
274/**
275 * vmw_validation_add_resource - Add a resource to the validation context.
276 * @ctx: The validation context.
277 * @res: The resource.
278 * @priv_size: Size of private, additional metadata.
279 * @dirty: Whether to change dirty status.
280 * @p_node: Output pointer of additional metadata address.
281 * @first_usage: Whether this was the first time this resource was seen.
282 *
283 * Return: Zero on success, negative error code otherwise.
284 */
285int vmw_validation_add_resource(struct vmw_validation_context *ctx,
286				struct vmw_resource *res,
287				size_t priv_size,
288				u32 dirty,
289				void **p_node,
290				bool *first_usage)
291{
292	struct vmw_validation_res_node *node;
293
294	node = vmw_validation_find_res_dup(ctx, res);
295	if (node) {
296		node->first_usage = 0;
297		goto out_fill;
298	}
299
300	node = vmw_validation_mem_alloc(ctx, sizeof(*node) + priv_size);
301	if (!node) {
302		VMW_DEBUG_USER("Failed to allocate a resource validation entry.\n");
303		return -ENOMEM;
304	}
305
306	if (ctx->sw_context) {
307		node->hash.key = (unsigned long) res;
308		hash_add_rcu(ctx->sw_context->res_ht, &node->hash.head, node->hash.key);
309	}
310	node->res = vmw_resource_reference_unless_doomed(res);
311	if (!node->res) {
312		hash_del_rcu(&node->hash.head);
313		return -ESRCH;
314	}
315
316	node->first_usage = 1;
317	if (!res->dev_priv->has_mob) {
318		list_add_tail(&node->head, &ctx->resource_list);
319	} else {
320		switch (vmw_res_type(res)) {
321		case vmw_res_context:
322		case vmw_res_dx_context:
323			list_add(&node->head, &ctx->resource_ctx_list);
324			break;
325		case vmw_res_cotable:
326			list_add_tail(&node->head, &ctx->resource_ctx_list);
327			break;
328		default:
329			list_add_tail(&node->head, &ctx->resource_list);
330			break;
331		}
332	}
333
334out_fill:
335	if (dirty) {
336		node->dirty_set = 1;
337		/* Overwriting previous information here is intentional! */
338		node->dirty = (dirty & VMW_RES_DIRTY_SET) ? 1 : 0;
339	}
340	if (first_usage)
341		*first_usage = node->first_usage;
342	if (p_node)
343		*p_node = &node->private;
344
345	return 0;
346}
347
348/**
349 * vmw_validation_res_set_dirty - Register a resource dirty set or clear during
350 * validation.
351 * @ctx: The validation context.
352 * @val_private: The additional meta-data pointer returned when the
353 * resource was registered with the validation context. Used to identify
354 * the resource.
355 * @dirty: Dirty information VMW_RES_DIRTY_XX
356 */
357void vmw_validation_res_set_dirty(struct vmw_validation_context *ctx,
358				  void *val_private, u32 dirty)
359{
360	struct vmw_validation_res_node *val;
361
362	if (!dirty)
363		return;
364
365	val = container_of(val_private, typeof(*val), private);
366	val->dirty_set = 1;
367	/* Overwriting previous information here is intentional! */
368	val->dirty = (dirty & VMW_RES_DIRTY_SET) ? 1 : 0;
369}
370
371/**
372 * vmw_validation_res_switch_backup - Register a backup MOB switch during
373 * validation.
374 * @ctx: The validation context.
375 * @val_private: The additional meta-data pointer returned when the
376 * resource was registered with the validation context. Used to identify
377 * the resource.
378 * @vbo: The new backup buffer object MOB. This buffer object needs to have
379 * already been registered with the validation context.
380 * @guest_memory_offset: Offset into the new backup MOB.
381 */
382void vmw_validation_res_switch_backup(struct vmw_validation_context *ctx,
383				      void *val_private,
384				      struct vmw_bo *vbo,
385				      unsigned long guest_memory_offset)
386{
387	struct vmw_validation_res_node *val;
388
389	val = container_of(val_private, typeof(*val), private);
390
391	val->switching_guest_memory_bo = 1;
392	if (val->first_usage)
393		val->no_buffer_needed = 1;
394
395	val->new_guest_memory_bo = vbo;
396	val->new_guest_memory_offset = guest_memory_offset;
397}
398
399/**
400 * vmw_validation_res_reserve - Reserve all resources registered with this
401 * validation context.
402 * @ctx: The validation context.
403 * @intr: Use interruptible waits when possible.
404 *
405 * Return: Zero on success, -ERESTARTSYS if interrupted. Negative error
406 * code on failure.
407 */
408int vmw_validation_res_reserve(struct vmw_validation_context *ctx,
409			       bool intr)
410{
411	struct vmw_validation_res_node *val;
412	int ret = 0;
413
414	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
415
416	list_for_each_entry(val, &ctx->resource_list, head) {
417		struct vmw_resource *res = val->res;
418
419		ret = vmw_resource_reserve(res, intr, val->no_buffer_needed);
420		if (ret)
421			goto out_unreserve;
422
423		val->reserved = 1;
424		if (res->guest_memory_bo) {
425			struct vmw_bo *vbo = res->guest_memory_bo;
426
427			vmw_bo_placement_set(vbo,
428					     res->func->domain,
429					     res->func->busy_domain);
430			ret = vmw_validation_add_bo(ctx, vbo);
431			if (ret)
432				goto out_unreserve;
433		}
434
435		if (val->switching_guest_memory_bo && val->new_guest_memory_bo &&
436		    res->coherent) {
437			struct vmw_validation_bo_node *bo_node =
438				vmw_validation_find_bo_dup(ctx,
439							   val->new_guest_memory_bo);
440
441			if (WARN_ON(!bo_node)) {
442				ret = -EINVAL;
443				goto out_unreserve;
444			}
445			bo_node->coherent_count++;
446		}
447	}
448
449	return 0;
450
451out_unreserve:
452	vmw_validation_res_unreserve(ctx, true);
453	return ret;
454}
455
456/**
457 * vmw_validation_res_unreserve - Unreserve all reserved resources
458 * registered with this validation context.
459 * @ctx: The validation context.
460 * @backoff: Whether this is a backoff- of a commit-type operation. This
461 * is used to determine whether to switch backup MOBs or not.
462 */
463void vmw_validation_res_unreserve(struct vmw_validation_context *ctx,
464				 bool backoff)
465{
466	struct vmw_validation_res_node *val;
467
468	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
469	if (backoff)
470		list_for_each_entry(val, &ctx->resource_list, head) {
471			if (val->reserved)
472				vmw_resource_unreserve(val->res,
473						       false, false, false,
474						       NULL, 0);
475		}
476	else
477		list_for_each_entry(val, &ctx->resource_list, head) {
478			if (val->reserved)
479				vmw_resource_unreserve(val->res,
480						       val->dirty_set,
481						       val->dirty,
482						       val->switching_guest_memory_bo,
483						       val->new_guest_memory_bo,
484						       val->new_guest_memory_offset);
485		}
486}
487
488/**
489 * vmw_validation_bo_validate_single - Validate a single buffer object.
490 * @bo: The TTM buffer object base.
491 * @interruptible: Whether to perform waits interruptible if possible.
492 *
493 * Return: Zero on success, -ERESTARTSYS if interrupted. Negative error
494 * code on failure.
495 */
496static int vmw_validation_bo_validate_single(struct ttm_buffer_object *bo,
497					     bool interruptible)
498{
499	struct vmw_bo *vbo = to_vmw_bo(&bo->base);
500	struct ttm_operation_ctx ctx = {
501		.interruptible = interruptible,
502		.no_wait_gpu = false
503	};
504	int ret;
505
506	if (atomic_read(&vbo->cpu_writers))
507		return -EBUSY;
508
509	if (vbo->tbo.pin_count > 0)
510		return 0;
511
512	ret = ttm_bo_validate(bo, &vbo->placement, &ctx);
513	if (ret == 0 || ret == -ERESTARTSYS)
514		return ret;
515
516	/*
517	 * If that failed, try again, this time evicting
518	 * previous contents.
519	 */
520	ctx.allow_res_evict = true;
521
522	return ttm_bo_validate(bo, &vbo->placement, &ctx);
523}
524
525/**
526 * vmw_validation_bo_validate - Validate all buffer objects registered with
527 * the validation context.
528 * @ctx: The validation context.
529 * @intr: Whether to perform waits interruptible if possible.
530 *
531 * Return: Zero on success, -ERESTARTSYS if interrupted,
532 * negative error code on failure.
533 */
534int vmw_validation_bo_validate(struct vmw_validation_context *ctx, bool intr)
535{
536	struct vmw_validation_bo_node *entry;
537	int ret;
538
539	list_for_each_entry(entry, &ctx->bo_list, base.head) {
540		struct vmw_bo *vbo = to_vmw_bo(&entry->base.bo->base);
541
542		ret = vmw_validation_bo_validate_single(entry->base.bo, intr);
543
544		if (ret)
545			return ret;
546
547		/*
548		 * Rather than having the resource code allocating the bo
549		 * dirty tracker in resource_unreserve() where we can't fail,
550		 * Do it here when validating the buffer object.
551		 */
552		if (entry->coherent_count) {
553			unsigned int coherent_count = entry->coherent_count;
554
555			while (coherent_count) {
556				ret = vmw_bo_dirty_add(vbo);
557				if (ret)
558					return ret;
559
560				coherent_count--;
561			}
562			entry->coherent_count -= coherent_count;
563		}
564
565		if (vbo->dirty)
566			vmw_bo_dirty_scan(vbo);
567	}
568	return 0;
569}
570
571/**
572 * vmw_validation_res_validate - Validate all resources registered with the
573 * validation context.
574 * @ctx: The validation context.
575 * @intr: Whether to perform waits interruptible if possible.
576 *
577 * Before this function is called, all resource backup buffers must have
578 * been validated.
579 *
580 * Return: Zero on success, -ERESTARTSYS if interrupted,
581 * negative error code on failure.
582 */
583int vmw_validation_res_validate(struct vmw_validation_context *ctx, bool intr)
584{
585	struct vmw_validation_res_node *val;
586	int ret;
587
588	list_for_each_entry(val, &ctx->resource_list, head) {
589		struct vmw_resource *res = val->res;
590		struct vmw_bo *backup = res->guest_memory_bo;
591
592		ret = vmw_resource_validate(res, intr, val->dirty_set &&
593					    val->dirty);
594		if (ret) {
595			if (ret != -ERESTARTSYS)
596				DRM_ERROR("Failed to validate resource.\n");
597			return ret;
598		}
599
600		/* Check if the resource switched backup buffer */
601		if (backup && res->guest_memory_bo && backup != res->guest_memory_bo) {
602			struct vmw_bo *vbo = res->guest_memory_bo;
603
604			vmw_bo_placement_set(vbo, res->func->domain,
605					     res->func->busy_domain);
606			ret = vmw_validation_add_bo(ctx, vbo);
607			if (ret)
608				return ret;
609		}
610	}
611	return 0;
612}
613
614/**
615 * vmw_validation_drop_ht - Reset the hash table used for duplicate finding
616 * and unregister it from this validation context.
617 * @ctx: The validation context.
618 *
619 * The hash table used for duplicate finding is an expensive resource and
620 * may be protected by mutexes that may cause deadlocks during resource
621 * unreferencing if held. After resource- and buffer object registering,
622 * there is no longer any use for this hash table, so allow freeing it
623 * either to shorten any mutex locking time, or before resources- and
624 * buffer objects are freed during validation context cleanup.
625 */
626void vmw_validation_drop_ht(struct vmw_validation_context *ctx)
627{
628	struct vmw_validation_bo_node *entry;
629	struct vmw_validation_res_node *val;
630
631	if (!ctx->sw_context)
632		return;
633
634	list_for_each_entry(entry, &ctx->bo_list, base.head)
635		hash_del_rcu(&entry->hash.head);
636
637	list_for_each_entry(val, &ctx->resource_list, head)
638		hash_del_rcu(&val->hash.head);
639
640	list_for_each_entry(val, &ctx->resource_ctx_list, head)
641		hash_del_rcu(&val->hash.head);
642
643	ctx->sw_context = NULL;
644}
645
646/**
647 * vmw_validation_unref_lists - Unregister previously registered buffer
648 * object and resources.
649 * @ctx: The validation context.
650 *
651 * Note that this function may cause buffer object- and resource destructors
652 * to be invoked.
653 */
654void vmw_validation_unref_lists(struct vmw_validation_context *ctx)
655{
656	struct vmw_validation_bo_node *entry;
657	struct vmw_validation_res_node *val;
658
659	list_for_each_entry(entry, &ctx->bo_list, base.head) {
660		drm_gem_object_put(&entry->base.bo->base);
661		entry->base.bo = NULL;
662	}
663
664	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
665	list_for_each_entry(val, &ctx->resource_list, head)
666		vmw_resource_unreference(&val->res);
667
668	/*
669	 * No need to detach each list entry since they are all freed with
670	 * vmw_validation_free_mem. Just make the inaccessible.
671	 */
672	INIT_LIST_HEAD(&ctx->bo_list);
673	INIT_LIST_HEAD(&ctx->resource_list);
674
675	vmw_validation_mem_free(ctx);
676}
677
678/**
679 * vmw_validation_prepare - Prepare a validation context for command
680 * submission.
681 * @ctx: The validation context.
682 * @mutex: The mutex used to protect resource reservation.
683 * @intr: Whether to perform waits interruptible if possible.
684 *
685 * Note that the single reservation mutex @mutex is an unfortunate
686 * construct. Ideally resource reservation should be moved to per-resource
687 * ww_mutexes.
688 * If this functions doesn't return Zero to indicate success, all resources
689 * are left unreserved but still referenced.
690 * Return: Zero on success, -ERESTARTSYS if interrupted, negative error code
691 * on error.
692 */
693int vmw_validation_prepare(struct vmw_validation_context *ctx,
694			   struct mutex *mutex,
695			   bool intr)
696{
697	int ret = 0;
698
699	if (mutex) {
700		if (intr)
701			ret = mutex_lock_interruptible(mutex);
702		else
703			mutex_lock(mutex);
704		if (ret)
705			return -ERESTARTSYS;
706	}
707
708	ctx->res_mutex = mutex;
709	ret = vmw_validation_res_reserve(ctx, intr);
710	if (ret)
711		goto out_no_res_reserve;
712
713	ret = vmw_validation_bo_reserve(ctx, intr);
714	if (ret)
715		goto out_no_bo_reserve;
716
717	ret = vmw_validation_bo_validate(ctx, intr);
718	if (ret)
719		goto out_no_validate;
720
721	ret = vmw_validation_res_validate(ctx, intr);
722	if (ret)
723		goto out_no_validate;
724
725	return 0;
726
727out_no_validate:
728	vmw_validation_bo_backoff(ctx);
729out_no_bo_reserve:
730	vmw_validation_res_unreserve(ctx, true);
731out_no_res_reserve:
732	if (mutex)
733		mutex_unlock(mutex);
734
735	return ret;
736}
737
738/**
739 * vmw_validation_revert - Revert validation actions if command submission
740 * failed.
741 *
742 * @ctx: The validation context.
743 *
744 * The caller still needs to unref resources after a call to this function.
745 */
746void vmw_validation_revert(struct vmw_validation_context *ctx)
747{
748	vmw_validation_bo_backoff(ctx);
749	vmw_validation_res_unreserve(ctx, true);
750	if (ctx->res_mutex)
751		mutex_unlock(ctx->res_mutex);
752	vmw_validation_unref_lists(ctx);
753}
754
755/**
756 * vmw_validation_done - Commit validation actions after command submission
757 * success.
758 * @ctx: The validation context.
759 * @fence: Fence with which to fence all buffer objects taking part in the
760 * command submission.
761 *
762 * The caller does NOT need to unref resources after a call to this function.
763 */
764void vmw_validation_done(struct vmw_validation_context *ctx,
765			 struct vmw_fence_obj *fence)
766{
767	vmw_validation_bo_fence(ctx, fence);
768	vmw_validation_res_unreserve(ctx, false);
769	if (ctx->res_mutex)
770		mutex_unlock(ctx->res_mutex);
771	vmw_validation_unref_lists(ctx);
772}
773
774/**
775 * vmw_validation_preload_bo - Preload the validation memory allocator for a
776 * call to vmw_validation_add_bo().
777 * @ctx: Pointer to the validation context.
778 *
779 * Iff this function returns successfully, the next call to
780 * vmw_validation_add_bo() is guaranteed not to sleep. An error is not fatal
781 * but voids the guarantee.
782 *
783 * Returns: Zero if successful, %-EINVAL otherwise.
784 */
785int vmw_validation_preload_bo(struct vmw_validation_context *ctx)
786{
787	unsigned int size = sizeof(struct vmw_validation_bo_node);
788
789	if (!vmw_validation_mem_alloc(ctx, size))
790		return -ENOMEM;
791
792	ctx->mem_size_left += size;
793	return 0;
794}
795
796/**
797 * vmw_validation_preload_res - Preload the validation memory allocator for a
798 * call to vmw_validation_add_res().
799 * @ctx: Pointer to the validation context.
800 * @size: Size of the validation node extra data. See below.
801 *
802 * Iff this function returns successfully, the next call to
803 * vmw_validation_add_res() with the same or smaller @size is guaranteed not to
804 * sleep. An error is not fatal but voids the guarantee.
805 *
806 * Returns: Zero if successful, %-EINVAL otherwise.
807 */
808int vmw_validation_preload_res(struct vmw_validation_context *ctx,
809			       unsigned int size)
810{
811	size = vmw_validation_align(sizeof(struct vmw_validation_res_node) +
812				    size) +
813		vmw_validation_align(sizeof(struct vmw_validation_bo_node));
814	if (!vmw_validation_mem_alloc(ctx, size))
815		return -ENOMEM;
816
817	ctx->mem_size_left += size;
818	return 0;
819}
820
821/**
822 * vmw_validation_bo_backoff - Unreserve buffer objects registered with a
823 * validation context
824 * @ctx: The validation context
825 *
826 * This function unreserves the buffer objects previously reserved using
827 * vmw_validation_bo_reserve. It's typically used as part of an error path
828 */
829void vmw_validation_bo_backoff(struct vmw_validation_context *ctx)
830{
831	struct vmw_validation_bo_node *entry;
832
833	/*
834	 * Switching coherent resource backup buffers failed.
835	 * Release corresponding buffer object dirty trackers.
836	 */
837	list_for_each_entry(entry, &ctx->bo_list, base.head) {
838		if (entry->coherent_count) {
839			unsigned int coherent_count = entry->coherent_count;
840			struct vmw_bo *vbo = to_vmw_bo(&entry->base.bo->base);
841
842			while (coherent_count--)
843				vmw_bo_dirty_release(vbo);
844		}
845	}
846
847	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->bo_list);
848}