Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 902 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
new file mode 100644
index 000000000..f5c4a40fb
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
@@ -0,0 +1,902 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/**************************************************************************
+ *
+ * Copyright © 2018 - 2022 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+#include <linux/slab.h>
+#include "vmwgfx_validation.h"
+#include "vmwgfx_drv.h"
+
+
+#define VMWGFX_VALIDATION_MEM_GRAN (16*PAGE_SIZE)
+
+/**
+ * struct vmw_validation_bo_node - Buffer object validation metadata.
+ * @base: Metadata used for TTM reservation- and validation.
+ * @hash: A hash entry used for the duplicate detection hash table.
+ * @coherent_count: If switching backup buffers, number of new coherent
+ * resources that will have this buffer as a backup buffer.
+ * @as_mob: Validate as mob.
+ * @cpu_blit: Validate for cpu blit access.
+ *
+ * Bit fields are used since these structures are allocated and freed in
+ * large numbers and space conservation is desired.
+ */
+struct vmw_validation_bo_node {
+	struct ttm_validate_buffer base;
+	struct vmwgfx_hash_item hash;
+	unsigned int coherent_count;
+	u32 as_mob : 1;
+	u32 cpu_blit : 1;
+};
+/**
+ * struct vmw_validation_res_node - Resource validation metadata.
+ * @head: List head for the resource validation list.
+ * @hash: A hash entry used for the duplicate detection hash table.
+ * @res: Reference counted resource pointer.
+ * @new_backup: Non ref-counted pointer to new backup buffer to be assigned
+ * to a resource.
+ * @new_backup_offset: Offset into the new backup mob for resources that can
+ * share MOBs.
+ * @no_buffer_needed: Kernel does not need to allocate a MOB during validation,
+ * the command stream provides a mob bind operation.
+ * @switching_backup: The validation process is switching backup MOB.
+ * @first_usage: True iff the resource has been seen only once in the current
+ * validation batch.
+ * @reserved: Whether the resource is currently reserved by this process.
+ * @dirty_set: Change dirty status of the resource.
+ * @dirty: Dirty information VMW_RES_DIRTY_XX.
+ * @private: Optionally additional memory for caller-private data.
+ *
+ * Bit fields are used since these structures are allocated and freed in
+ * large numbers and space conservation is desired.
+ */
+struct vmw_validation_res_node {
+	struct list_head head;
+	struct vmwgfx_hash_item hash;
+	struct vmw_resource *res;
+	struct vmw_buffer_object *new_backup;
+	unsigned long new_backup_offset;
+	u32 no_buffer_needed : 1;
+	u32 switching_backup : 1;
+	u32 first_usage : 1;
+	u32 reserved : 1;
+	u32 dirty : 1;
+	u32 dirty_set : 1;
+	unsigned long private[];
+};
+
+/**
+ * vmw_validation_mem_alloc - Allocate kernel memory from the validation
+ * context based allocator
+ * @ctx: The validation context
+ * @size: The number of bytes to allocated.
+ *
+ * The memory allocated may not exceed PAGE_SIZE, and the returned
+ * address is aligned to sizeof(long). All memory allocated this way is
+ * reclaimed after validation when calling any of the exported functions:
+ * vmw_validation_unref_lists()
+ * vmw_validation_revert()
+ * vmw_validation_done()
+ *
+ * Return: Pointer to the allocated memory on success. NULL on failure.
+ */
+void *vmw_validation_mem_alloc(struct vmw_validation_context *ctx,
+			       unsigned int size)
+{
+	void *addr;
+
+	size = vmw_validation_align(size);
+	if (size > PAGE_SIZE)
+		return NULL;
+
+	if (ctx->mem_size_left < size) {
+		struct page *page;
+
+		if (ctx->vm && ctx->vm_size_left < PAGE_SIZE) {
+			ctx->vm_size_left += VMWGFX_VALIDATION_MEM_GRAN;
+			ctx->total_mem += VMWGFX_VALIDATION_MEM_GRAN;
+		}
+
+		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+		if (!page)
+			return NULL;
+
+		if (ctx->vm)
+			ctx->vm_size_left -= PAGE_SIZE;
+
+		list_add_tail(&page->lru, &ctx->page_list);
+		ctx->page_address = page_address(page);
+		ctx->mem_size_left = PAGE_SIZE;
+	}
+
+	addr = (void *) (ctx->page_address + (PAGE_SIZE - ctx->mem_size_left));
+	ctx->mem_size_left -= size;
+
+	return addr;
+}
+
+/**
+ * vmw_validation_mem_free - Free all memory allocated using
+ * vmw_validation_mem_alloc()
+ * @ctx: The validation context
+ *
+ * All memory previously allocated for this context using
+ * vmw_validation_mem_alloc() is freed.
+ */
+static void vmw_validation_mem_free(struct vmw_validation_context *ctx)
+{
+	struct page *entry, *next;
+
+	list_for_each_entry_safe(entry, next, &ctx->page_list, lru) {
+		list_del_init(&entry->lru);
+		__free_page(entry);
+	}
+
+	ctx->mem_size_left = 0;
+	if (ctx->vm && ctx->total_mem) {
+		ctx->total_mem = 0;
+		ctx->vm_size_left = 0;
+	}
+}
+
+/**
+ * vmw_validation_find_bo_dup - Find a duplicate buffer object entry in the
+ * validation context's lists.
+ * @ctx: The validation context to search.
+ * @vbo: The buffer object to search for.
+ *
+ * Return: Pointer to the struct vmw_validation_bo_node referencing the
+ * duplicate, or NULL if none found.
+ */
+static struct vmw_validation_bo_node *
+vmw_validation_find_bo_dup(struct vmw_validation_context *ctx,
+			   struct vmw_buffer_object *vbo)
+{
+	struct  vmw_validation_bo_node *bo_node = NULL;
+
+	if (!ctx->merge_dups)
+		return NULL;
+
+	if (ctx->sw_context) {
+		struct vmwgfx_hash_item *hash;
+		unsigned long key = (unsigned long) vbo;
+
+		hash_for_each_possible_rcu(ctx->sw_context->res_ht, hash, head, key) {
+			if (hash->key == key) {
+				bo_node = container_of(hash, typeof(*bo_node), hash);
+				break;
+			}
+		}
+	} else {
+		struct  vmw_validation_bo_node *entry;
+
+		list_for_each_entry(entry, &ctx->bo_list, base.head) {
+			if (entry->base.bo == &vbo->base) {
+				bo_node = entry;
+				break;
+			}
+		}
+	}
+
+	return bo_node;
+}
+
+/**
+ * vmw_validation_find_res_dup - Find a duplicate resource entry in the
+ * validation context's lists.
+ * @ctx: The validation context to search.
+ * @res: Reference counted resource pointer.
+ *
+ * Return: Pointer to the struct vmw_validation_bo_node referencing the
+ * duplicate, or NULL if none found.
+ */
+static struct vmw_validation_res_node *
+vmw_validation_find_res_dup(struct vmw_validation_context *ctx,
+			    struct vmw_resource *res)
+{
+	struct  vmw_validation_res_node *res_node = NULL;
+
+	if (!ctx->merge_dups)
+		return NULL;
+
+	if (ctx->sw_context) {
+		struct vmwgfx_hash_item *hash;
+		unsigned long key = (unsigned long) res;
+
+		hash_for_each_possible_rcu(ctx->sw_context->res_ht, hash, head, key) {
+			if (hash->key == key) {
+				res_node = container_of(hash, typeof(*res_node), hash);
+				break;
+			}
+		}
+	} else {
+		struct  vmw_validation_res_node *entry;
+
+		list_for_each_entry(entry, &ctx->resource_ctx_list, head) {
+			if (entry->res == res) {
+				res_node = entry;
+				goto out;
+			}
+		}
+
+		list_for_each_entry(entry, &ctx->resource_list, head) {
+			if (entry->res == res) {
+				res_node = entry;
+				break;
+			}
+		}
+
+	}
+out:
+	return res_node;
+}
+
+/**
+ * vmw_validation_add_bo - Add a buffer object to the validation context.
+ * @ctx: The validation context.
+ * @vbo: The buffer object.
+ * @as_mob: Validate as mob, otherwise suitable for GMR operations.
+ * @cpu_blit: Validate in a page-mappable location.
+ *
+ * Return: Zero on success, negative error code otherwise.
+ */
+int vmw_validation_add_bo(struct vmw_validation_context *ctx,
+			  struct vmw_buffer_object *vbo,
+			  bool as_mob,
+			  bool cpu_blit)
+{
+	struct vmw_validation_bo_node *bo_node;
+
+	bo_node = vmw_validation_find_bo_dup(ctx, vbo);
+	if (bo_node) {
+		if (bo_node->as_mob != as_mob ||
+		    bo_node->cpu_blit != cpu_blit) {
+			DRM_ERROR("Inconsistent buffer usage.\n");
+			return -EINVAL;
+		}
+	} else {
+		struct ttm_validate_buffer *val_buf;
+
+		bo_node = vmw_validation_mem_alloc(ctx, sizeof(*bo_node));
+		if (!bo_node)
+			return -ENOMEM;
+
+		if (ctx->sw_context) {
+			bo_node->hash.key = (unsigned long) vbo;
+			hash_add_rcu(ctx->sw_context->res_ht, &bo_node->hash.head,
+				bo_node->hash.key);
+		}
+		val_buf = &bo_node->base;
+		val_buf->bo = ttm_bo_get_unless_zero(&vbo->base);
+		if (!val_buf->bo)
+			return -ESRCH;
+		val_buf->num_shared = 0;
+		list_add_tail(&val_buf->head, &ctx->bo_list);
+		bo_node->as_mob = as_mob;
+		bo_node->cpu_blit = cpu_blit;
+	}
+
+	return 0;
+}
+
+/**
+ * vmw_validation_add_resource - Add a resource to the validation context.
+ * @ctx: The validation context.
+ * @res: The resource.
+ * @priv_size: Size of private, additional metadata.
+ * @dirty: Whether to change dirty status.
+ * @p_node: Output pointer of additional metadata address.
+ * @first_usage: Whether this was the first time this resource was seen.
+ *
+ * Return: Zero on success, negative error code otherwise.
+ */
+int vmw_validation_add_resource(struct vmw_validation_context *ctx,
+				struct vmw_resource *res,
+				size_t priv_size,
+				u32 dirty,
+				void **p_node,
+				bool *first_usage)
+{
+	struct vmw_validation_res_node *node;
+
+	node = vmw_validation_find_res_dup(ctx, res);
+	if (node) {
+		node->first_usage = 0;
+		goto out_fill;
+	}
+
+	node = vmw_validation_mem_alloc(ctx, sizeof(*node) + priv_size);
+	if (!node) {
+		VMW_DEBUG_USER("Failed to allocate a resource validation entry.\n");
+		return -ENOMEM;
+	}
+
+	if (ctx->sw_context) {
+		node->hash.key = (unsigned long) res;
+		hash_add_rcu(ctx->sw_context->res_ht, &node->hash.head, node->hash.key);
+	}
+	node->res = vmw_resource_reference_unless_doomed(res);
+	if (!node->res)
+		return -ESRCH;
+
+	node->first_usage = 1;
+	if (!res->dev_priv->has_mob) {
+		list_add_tail(&node->head, &ctx->resource_list);
+	} else {
+		switch (vmw_res_type(res)) {
+		case vmw_res_context:
+		case vmw_res_dx_context:
+			list_add(&node->head, &ctx->resource_ctx_list);
+			break;
+		case vmw_res_cotable:
+			list_add_tail(&node->head, &ctx->resource_ctx_list);
+			break;
+		default:
+			list_add_tail(&node->head, &ctx->resource_list);
+			break;
+		}
+	}
+
+out_fill:
+	if (dirty) {
+		node->dirty_set = 1;
+		/* Overwriting previous information here is intentional! */
+		node->dirty = (dirty & VMW_RES_DIRTY_SET) ? 1 : 0;
+	}
+	if (first_usage)
+		*first_usage = node->first_usage;
+	if (p_node)
+		*p_node = &node->private;
+
+	return 0;
+}
+
+/**
+ * vmw_validation_res_set_dirty - Register a resource dirty set or clear during
+ * validation.
+ * @ctx: The validation context.
+ * @val_private: The additional meta-data pointer returned when the
+ * resource was registered with the validation context. Used to identify
+ * the resource.
+ * @dirty: Dirty information VMW_RES_DIRTY_XX
+ */
+void vmw_validation_res_set_dirty(struct vmw_validation_context *ctx,
+				  void *val_private, u32 dirty)
+{
+	struct vmw_validation_res_node *val;
+
+	if (!dirty)
+		return;
+
+	val = container_of(val_private, typeof(*val), private);
+	val->dirty_set = 1;
+	/* Overwriting previous information here is intentional! */
+	val->dirty = (dirty & VMW_RES_DIRTY_SET) ? 1 : 0;
+}
+
+/**
+ * vmw_validation_res_switch_backup - Register a backup MOB switch during
+ * validation.
+ * @ctx: The validation context.
+ * @val_private: The additional meta-data pointer returned when the
+ * resource was registered with the validation context. Used to identify
+ * the resource.
+ * @vbo: The new backup buffer object MOB. This buffer object needs to have
+ * already been registered with the validation context.
+ * @backup_offset: Offset into the new backup MOB.
+ */
+void vmw_validation_res_switch_backup(struct vmw_validation_context *ctx,
+				      void *val_private,
+				      struct vmw_buffer_object *vbo,
+				      unsigned long backup_offset)
+{
+	struct vmw_validation_res_node *val;
+
+	val = container_of(val_private, typeof(*val), private);
+
+	val->switching_backup = 1;
+	if (val->first_usage)
+		val->no_buffer_needed = 1;
+
+	val->new_backup = vbo;
+	val->new_backup_offset = backup_offset;
+}
+
+/**
+ * vmw_validation_res_reserve - Reserve all resources registered with this
+ * validation context.
+ * @ctx: The validation context.
+ * @intr: Use interruptible waits when possible.
+ *
+ * Return: Zero on success, -ERESTARTSYS if interrupted. Negative error
+ * code on failure.
+ */
+int vmw_validation_res_reserve(struct vmw_validation_context *ctx,
+			       bool intr)
+{
+	struct vmw_validation_res_node *val;
+	int ret = 0;
+
+	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
+
+	list_for_each_entry(val, &ctx->resource_list, head) {
+		struct vmw_resource *res = val->res;
+
+		ret = vmw_resource_reserve(res, intr, val->no_buffer_needed);
+		if (ret)
+			goto out_unreserve;
+
+		val->reserved = 1;
+		if (res->backup) {
+			struct vmw_buffer_object *vbo = res->backup;
+
+			ret = vmw_validation_add_bo
+				(ctx, vbo, vmw_resource_needs_backup(res),
+				 false);
+			if (ret)
+				goto out_unreserve;
+		}
+
+		if (val->switching_backup && val->new_backup &&
+		    res->coherent) {
+			struct vmw_validation_bo_node *bo_node =
+				vmw_validation_find_bo_dup(ctx,
+							   val->new_backup);
+
+			if (WARN_ON(!bo_node)) {
+				ret = -EINVAL;
+				goto out_unreserve;
+			}
+			bo_node->coherent_count++;
+		}
+	}
+
+	return 0;
+
+out_unreserve:
+	vmw_validation_res_unreserve(ctx, true);
+	return ret;
+}
+
+/**
+ * vmw_validation_res_unreserve - Unreserve all reserved resources
+ * registered with this validation context.
+ * @ctx: The validation context.
+ * @backoff: Whether this is a backoff- of a commit-type operation. This
+ * is used to determine whether to switch backup MOBs or not.
+ */
+void vmw_validation_res_unreserve(struct vmw_validation_context *ctx,
+				 bool backoff)
+{
+	struct vmw_validation_res_node *val;
+
+	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
+	if (backoff)
+		list_for_each_entry(val, &ctx->resource_list, head) {
+			if (val->reserved)
+				vmw_resource_unreserve(val->res,
+						       false, false, false,
+						       NULL, 0);
+		}
+	else
+		list_for_each_entry(val, &ctx->resource_list, head) {
+			if (val->reserved)
+				vmw_resource_unreserve(val->res,
+						       val->dirty_set,
+						       val->dirty,
+						       val->switching_backup,
+						       val->new_backup,
+						       val->new_backup_offset);
+		}
+}
+
+/**
+ * vmw_validation_bo_validate_single - Validate a single buffer object.
+ * @bo: The TTM buffer object base.
+ * @interruptible: Whether to perform waits interruptible if possible.
+ * @validate_as_mob: Whether to validate in MOB memory.
+ *
+ * Return: Zero on success, -ERESTARTSYS if interrupted. Negative error
+ * code on failure.
+ */
+int vmw_validation_bo_validate_single(struct ttm_buffer_object *bo,
+				      bool interruptible,
+				      bool validate_as_mob)
+{
+	struct vmw_buffer_object *vbo =
+		container_of(bo, struct vmw_buffer_object, base);
+	struct ttm_operation_ctx ctx = {
+		.interruptible = interruptible,
+		.no_wait_gpu = false
+	};
+	int ret;
+
+	if (atomic_read(&vbo->cpu_writers))
+		return -EBUSY;
+
+	if (vbo->base.pin_count > 0)
+		return 0;
+
+	if (validate_as_mob)
+		return ttm_bo_validate(bo, &vmw_mob_placement, &ctx);
+
+	/**
+	 * Put BO in VRAM if there is space, otherwise as a GMR.
+	 * If there is no space in VRAM and GMR ids are all used up,
+	 * start evicting GMRs to make room. If the DMA buffer can't be
+	 * used as a GMR, this will return -ENOMEM.
+	 */
+
+	ret = ttm_bo_validate(bo, &vmw_vram_gmr_placement, &ctx);
+	if (ret == 0 || ret == -ERESTARTSYS)
+		return ret;
+
+	/**
+	 * If that failed, try VRAM again, this time evicting
+	 * previous contents.
+	 */
+
+	ret = ttm_bo_validate(bo, &vmw_vram_placement, &ctx);
+	return ret;
+}
+
+/**
+ * vmw_validation_bo_validate - Validate all buffer objects registered with
+ * the validation context.
+ * @ctx: The validation context.
+ * @intr: Whether to perform waits interruptible if possible.
+ *
+ * Return: Zero on success, -ERESTARTSYS if interrupted,
+ * negative error code on failure.
+ */
+int vmw_validation_bo_validate(struct vmw_validation_context *ctx, bool intr)
+{
+	struct vmw_validation_bo_node *entry;
+	int ret;
+
+	list_for_each_entry(entry, &ctx->bo_list, base.head) {
+		struct vmw_buffer_object *vbo =
+			container_of(entry->base.bo, typeof(*vbo), base);
+
+		if (entry->cpu_blit) {
+			struct ttm_operation_ctx ttm_ctx = {
+				.interruptible = intr,
+				.no_wait_gpu = false
+			};
+
+			ret = ttm_bo_validate(entry->base.bo,
+					      &vmw_nonfixed_placement, &ttm_ctx);
+		} else {
+			ret = vmw_validation_bo_validate_single
+			(entry->base.bo, intr, entry->as_mob);
+		}
+		if (ret)
+			return ret;
+
+		/*
+		 * Rather than having the resource code allocating the bo
+		 * dirty tracker in resource_unreserve() where we can't fail,
+		 * Do it here when validating the buffer object.
+		 */
+		if (entry->coherent_count) {
+			unsigned int coherent_count = entry->coherent_count;
+
+			while (coherent_count) {
+				ret = vmw_bo_dirty_add(vbo);
+				if (ret)
+					return ret;
+
+				coherent_count--;
+			}
+			entry->coherent_count -= coherent_count;
+		}
+
+		if (vbo->dirty)
+			vmw_bo_dirty_scan(vbo);
+	}
+	return 0;
+}
+
+/**
+ * vmw_validation_res_validate - Validate all resources registered with the
+ * validation context.
+ * @ctx: The validation context.
+ * @intr: Whether to perform waits interruptible if possible.
+ *
+ * Before this function is called, all resource backup buffers must have
+ * been validated.
+ *
+ * Return: Zero on success, -ERESTARTSYS if interrupted,
+ * negative error code on failure.
+ */
+int vmw_validation_res_validate(struct vmw_validation_context *ctx, bool intr)
+{
+	struct vmw_validation_res_node *val;
+	int ret;
+
+	list_for_each_entry(val, &ctx->resource_list, head) {
+		struct vmw_resource *res = val->res;
+		struct vmw_buffer_object *backup = res->backup;
+
+		ret = vmw_resource_validate(res, intr, val->dirty_set &&
+					    val->dirty);
+		if (ret) {
+			if (ret != -ERESTARTSYS)
+				DRM_ERROR("Failed to validate resource.\n");
+			return ret;
+		}
+
+		/* Check if the resource switched backup buffer */
+		if (backup && res->backup && (backup != res->backup)) {
+			struct vmw_buffer_object *vbo = res->backup;
+
+			ret = vmw_validation_add_bo
+				(ctx, vbo, vmw_resource_needs_backup(res),
+				 false);
+			if (ret)
+				return ret;
+		}
+	}
+	return 0;
+}
+
+/**
+ * vmw_validation_drop_ht - Reset the hash table used for duplicate finding
+ * and unregister it from this validation context.
+ * @ctx: The validation context.
+ *
+ * The hash table used for duplicate finding is an expensive resource and
+ * may be protected by mutexes that may cause deadlocks during resource
+ * unreferencing if held. After resource- and buffer object registering,
+ * there is no longer any use for this hash table, so allow freeing it
+ * either to shorten any mutex locking time, or before resources- and
+ * buffer objects are freed during validation context cleanup.
+ */
+void vmw_validation_drop_ht(struct vmw_validation_context *ctx)
+{
+	struct vmw_validation_bo_node *entry;
+	struct vmw_validation_res_node *val;
+
+	if (!ctx->sw_context)
+		return;
+
+	list_for_each_entry(entry, &ctx->bo_list, base.head)
+		hash_del_rcu(&entry->hash.head);
+
+	list_for_each_entry(val, &ctx->resource_list, head)
+		hash_del_rcu(&val->hash.head);
+
+	list_for_each_entry(val, &ctx->resource_ctx_list, head)
+		hash_del_rcu(&entry->hash.head);
+
+	ctx->sw_context = NULL;
+}
+
+/**
+ * vmw_validation_unref_lists - Unregister previously registered buffer
+ * object and resources.
+ * @ctx: The validation context.
+ *
+ * Note that this function may cause buffer object- and resource destructors
+ * to be invoked.
+ */
+void vmw_validation_unref_lists(struct vmw_validation_context *ctx)
+{
+	struct vmw_validation_bo_node *entry;
+	struct vmw_validation_res_node *val;
+
+	list_for_each_entry(entry, &ctx->bo_list, base.head) {
+		ttm_bo_put(entry->base.bo);
+		entry->base.bo = NULL;
+	}
+
+	list_splice_init(&ctx->resource_ctx_list, &ctx->resource_list);
+	list_for_each_entry(val, &ctx->resource_list, head)
+		vmw_resource_unreference(&val->res);
+
+	/*
+	 * No need to detach each list entry since they are all freed with
+	 * vmw_validation_free_mem. Just make the inaccessible.
+	 */
+	INIT_LIST_HEAD(&ctx->bo_list);
+	INIT_LIST_HEAD(&ctx->resource_list);
+
+	vmw_validation_mem_free(ctx);
+}
+
+/**
+ * vmw_validation_prepare - Prepare a validation context for command
+ * submission.
+ * @ctx: The validation context.
+ * @mutex: The mutex used to protect resource reservation.
+ * @intr: Whether to perform waits interruptible if possible.
+ *
+ * Note that the single reservation mutex @mutex is an unfortunate
+ * construct. Ideally resource reservation should be moved to per-resource
+ * ww_mutexes.
+ * If this functions doesn't return Zero to indicate success, all resources
+ * are left unreserved but still referenced.
+ * Return: Zero on success, -ERESTARTSYS if interrupted, negative error code
+ * on error.
+ */
+int vmw_validation_prepare(struct vmw_validation_context *ctx,
+			   struct mutex *mutex,
+			   bool intr)
+{
+	int ret = 0;
+
+	if (mutex) {
+		if (intr)
+			ret = mutex_lock_interruptible(mutex);
+		else
+			mutex_lock(mutex);
+		if (ret)
+			return -ERESTARTSYS;
+	}
+
+	ctx->res_mutex = mutex;
+	ret = vmw_validation_res_reserve(ctx, intr);
+	if (ret)
+		goto out_no_res_reserve;
+
+	ret = vmw_validation_bo_reserve(ctx, intr);
+	if (ret)
+		goto out_no_bo_reserve;
+
+	ret = vmw_validation_bo_validate(ctx, intr);
+	if (ret)
+		goto out_no_validate;
+
+	ret = vmw_validation_res_validate(ctx, intr);
+	if (ret)
+		goto out_no_validate;
+
+	return 0;
+
+out_no_validate:
+	vmw_validation_bo_backoff(ctx);
+out_no_bo_reserve:
+	vmw_validation_res_unreserve(ctx, true);
+out_no_res_reserve:
+	if (mutex)
+		mutex_unlock(mutex);
+
+	return ret;
+}
+
+/**
+ * vmw_validation_revert - Revert validation actions if command submission
+ * failed.
+ *
+ * @ctx: The validation context.
+ *
+ * The caller still needs to unref resources after a call to this function.
+ */
+void vmw_validation_revert(struct vmw_validation_context *ctx)
+{
+	vmw_validation_bo_backoff(ctx);
+	vmw_validation_res_unreserve(ctx, true);
+	if (ctx->res_mutex)
+		mutex_unlock(ctx->res_mutex);
+	vmw_validation_unref_lists(ctx);
+}
+
+/**
+ * vmw_validation_done - Commit validation actions after command submission
+ * success.
+ * @ctx: The validation context.
+ * @fence: Fence with which to fence all buffer objects taking part in the
+ * command submission.
+ *
+ * The caller does NOT need to unref resources after a call to this function.
+ */
+void vmw_validation_done(struct vmw_validation_context *ctx,
+			 struct vmw_fence_obj *fence)
+{
+	vmw_validation_bo_fence(ctx, fence);
+	vmw_validation_res_unreserve(ctx, false);
+	if (ctx->res_mutex)
+		mutex_unlock(ctx->res_mutex);
+	vmw_validation_unref_lists(ctx);
+}
+
+/**
+ * vmw_validation_preload_bo - Preload the validation memory allocator for a
+ * call to vmw_validation_add_bo().
+ * @ctx: Pointer to the validation context.
+ *
+ * Iff this function returns successfully, the next call to
+ * vmw_validation_add_bo() is guaranteed not to sleep. An error is not fatal
+ * but voids the guarantee.
+ *
+ * Returns: Zero if successful, %-EINVAL otherwise.
+ */
+int vmw_validation_preload_bo(struct vmw_validation_context *ctx)
+{
+	unsigned int size = sizeof(struct vmw_validation_bo_node);
+
+	if (!vmw_validation_mem_alloc(ctx, size))
+		return -ENOMEM;
+
+	ctx->mem_size_left += size;
+	return 0;
+}
+
+/**
+ * vmw_validation_preload_res - Preload the validation memory allocator for a
+ * call to vmw_validation_add_res().
+ * @ctx: Pointer to the validation context.
+ * @size: Size of the validation node extra data. See below.
+ *
+ * Iff this function returns successfully, the next call to
+ * vmw_validation_add_res() with the same or smaller @size is guaranteed not to
+ * sleep. An error is not fatal but voids the guarantee.
+ *
+ * Returns: Zero if successful, %-EINVAL otherwise.
+ */
+int vmw_validation_preload_res(struct vmw_validation_context *ctx,
+			       unsigned int size)
+{
+	size = vmw_validation_align(sizeof(struct vmw_validation_res_node) +
+				    size) +
+		vmw_validation_align(sizeof(struct vmw_validation_bo_node));
+	if (!vmw_validation_mem_alloc(ctx, size))
+		return -ENOMEM;
+
+	ctx->mem_size_left += size;
+	return 0;
+}
+
+/**
+ * vmw_validation_bo_backoff - Unreserve buffer objects registered with a
+ * validation context
+ * @ctx: The validation context
+ *
+ * This function unreserves the buffer objects previously reserved using
+ * vmw_validation_bo_reserve. It's typically used as part of an error path
+ */
+void vmw_validation_bo_backoff(struct vmw_validation_context *ctx)
+{
+	struct vmw_validation_bo_node *entry;
+
+	/*
+	 * Switching coherent resource backup buffers failed.
+	 * Release corresponding buffer object dirty trackers.
+	 */
+	list_for_each_entry(entry, &ctx->bo_list, base.head) {
+		if (entry->coherent_count) {
+			unsigned int coherent_count = entry->coherent_count;
+			struct vmw_buffer_object *vbo =
+				container_of(entry->base.bo, typeof(*vbo),
+					     base);
+
+			while (coherent_count--)
+				vmw_bo_dirty_release(vbo);
+		}
+	}
+
+	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->bo_list);
+}