drivers/gpu/drm/vmwgfx/vmwgfx_so.c - linux/kernel/git/davem/net - Git at Google

 // SPDX-License-Identifier: GPL-2.0 OR MIT
 /**************************************************************************
  * Copyright 2014-2015 VMware, Inc., Palo Alto, CA., USA
  *
  * 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 "vmwgfx_drv.h"
 #include "vmwgfx_resource_priv.h"
 #include "vmwgfx_so.h"
 #include "vmwgfx_binding.h"

 /*
  * The currently only reason we need to keep track of views is that if we
  * destroy a hardware surface, all views pointing to it must also be destroyed,
  * otherwise the device will error.
  * So in particuar if a surface is evicted, we must destroy all views pointing
  * to it, and all context bindings of that view. Similarly we must restore
  * the view bindings, views and surfaces pointed to by the views when a
  * context is referenced in the command stream.
  */

 /**
  * struct vmw_view - view metadata
  *
  * @res: The struct vmw_resource we derive from
  * @ctx: Non-refcounted pointer to the context this view belongs to.
  * @srf: Refcounted pointer to the surface pointed to by this view.
  * @cotable: Refcounted pointer to the cotable holding this view.
  * @srf_head: List head for the surface-to-view list.
  * @cotable_head: List head for the cotable-to_view list.
  * @view_type: View type.
  * @view_id: User-space per context view id. Currently used also as per
  * context device view id.
  * @cmd_size: Size of the SVGA3D define view command that we've copied from the
  * command stream.
  * @committed: Whether the view is actually created or pending creation at the
  * device level.
  * @cmd: The SVGA3D define view command copied from the command stream.
  */
 struct vmw_view {
 	struct rcu_head rcu;
 	struct vmw_resource res;
 	struct vmw_resource *ctx;      /* Immutable */
 	struct vmw_resource *srf;      /* Immutable */
 	struct vmw_resource *cotable;  /* Immutable */
 	struct list_head srf_head;     /* Protected by binding_mutex */
 	struct list_head cotable_head; /* Protected by binding_mutex */
 	unsigned view_type;            /* Immutable */
 	unsigned view_id;              /* Immutable */
 	u32 cmd_size;                  /* Immutable */
 	bool committed;                /* Protected by binding_mutex */
 	u32 cmd[1];                    /* Immutable */
 };

 static int vmw_view_create(struct vmw_resource *res);
 static int vmw_view_destroy(struct vmw_resource *res);
 static void vmw_hw_view_destroy(struct vmw_resource *res);
 static void vmw_view_commit_notify(struct vmw_resource *res,
 				   enum vmw_cmdbuf_res_state state);

 static const struct vmw_res_func vmw_view_func = {
 	.res_type = vmw_res_view,
 	.needs_backup = false,
 	.may_evict = false,
 	.type_name = "DX view",
 	.backup_placement = NULL,
 	.create = vmw_view_create,
 	.commit_notify = vmw_view_commit_notify,
 };

 /**
  * struct vmw_view - view define command body stub
  *
  * @view_id: The device id of the view being defined
  * @sid: The surface id of the view being defined
  *
  * This generic struct is used by the code to change @view_id and @sid of a
  * saved view define command.
  */
 struct vmw_view_define {
 	uint32 view_id;
 	uint32 sid;
 };

 /**
  * vmw_view - Convert a struct vmw_resource to a struct vmw_view
  *
  * @res: Pointer to the resource to convert.
  *
  * Returns a pointer to a struct vmw_view.
  */
 static struct vmw_view *vmw_view(struct vmw_resource *res)
 {
 	return container_of(res, struct vmw_view, res);
 }

 /**
  * vmw_view_commit_notify - Notify that a view operation has been committed to
  * hardware from a user-supplied command stream.
  *
  * @res: Pointer to the view resource.
  * @state: Indicating whether a creation or removal has been committed.
  *
  */
 static void vmw_view_commit_notify(struct vmw_resource *res,
 				   enum vmw_cmdbuf_res_state state)
 {
 	struct vmw_view *view = vmw_view(res);
 	struct vmw_private *dev_priv = res->dev_priv;

 	mutex_lock(&dev_priv->binding_mutex);
 	if (state == VMW_CMDBUF_RES_ADD) {
 		struct vmw_surface *srf = vmw_res_to_srf(view->srf);

 		list_add_tail(&view->srf_head, &srf->view_list);
 		vmw_cotable_add_resource(view->cotable, &view->cotable_head);
 		view->committed = true;
 		res->id = view->view_id;

 	} else {
 		list_del_init(&view->cotable_head);
 		list_del_init(&view->srf_head);
 		view->committed = false;
 		res->id = -1;
 	}
 	mutex_unlock(&dev_priv->binding_mutex);
 }

 /**
  * vmw_view_create - Create a hardware view.
  *
  * @res: Pointer to the view resource.
  *
  * Create a hardware view. Typically used if that view has previously been
  * destroyed by an eviction operation.
  */
 static int vmw_view_create(struct vmw_resource *res)
 {
 	struct vmw_view *view = vmw_view(res);
 	struct vmw_surface *srf = vmw_res_to_srf(view->srf);
 	struct vmw_private *dev_priv = res->dev_priv;
 	struct {
 		SVGA3dCmdHeader header;
 		struct vmw_view_define body;
 	} *cmd;

 	mutex_lock(&dev_priv->binding_mutex);
 	if (!view->committed) {
 		mutex_unlock(&dev_priv->binding_mutex);
 		return 0;
 	}

 	cmd = VMW_FIFO_RESERVE_DX(res->dev_priv, view->cmd_size, view->ctx->id);
 	if (!cmd) {
 		mutex_unlock(&dev_priv->binding_mutex);
 		return -ENOMEM;
 	}

 	memcpy(cmd, &view->cmd, view->cmd_size);
 	WARN_ON(cmd->body.view_id != view->view_id);
 	/* Sid may have changed due to surface eviction. */
 	WARN_ON(view->srf->id == SVGA3D_INVALID_ID);
 	cmd->body.sid = view->srf->id;
 	vmw_fifo_commit(res->dev_priv, view->cmd_size);
 	res->id = view->view_id;
 	list_add_tail(&view->srf_head, &srf->view_list);
 	vmw_cotable_add_resource(view->cotable, &view->cotable_head);
 	mutex_unlock(&dev_priv->binding_mutex);

 	return 0;
 }

 /**
  * vmw_view_destroy - Destroy a hardware view.
  *
  * @res: Pointer to the view resource.
  *
  * Destroy a hardware view. Typically used on unexpected termination of the
  * owning process or if the surface the view is pointing to is destroyed.
  */
 static int vmw_view_destroy(struct vmw_resource *res)
 {
 	struct vmw_private *dev_priv = res->dev_priv;
 	struct vmw_view *view = vmw_view(res);
 	struct {
 		SVGA3dCmdHeader header;
 		union vmw_view_destroy body;
 	} *cmd;

 	lockdep_assert_held_once(&dev_priv->binding_mutex);
 	vmw_binding_res_list_scrub(&res->binding_head);

 	if (!view->committed || res->id == -1)
 		return 0;

 	cmd = VMW_FIFO_RESERVE_DX(dev_priv, sizeof(*cmd), view->ctx->id);
 	if (!cmd)
 		return -ENOMEM;

 	cmd->header.id = vmw_view_destroy_cmds[view->view_type];
 	cmd->header.size = sizeof(cmd->body);
 	cmd->body.view_id = view->view_id;
 	vmw_fifo_commit(dev_priv, sizeof(*cmd));
 	res->id = -1;
 	list_del_init(&view->cotable_head);
 	list_del_init(&view->srf_head);

 	return 0;
 }

 /**
  * vmw_hw_view_destroy - Destroy a hardware view as part of resource cleanup.
  *
  * @res: Pointer to the view resource.
  *
  * Destroy a hardware view if it's still present.
  */
 static void vmw_hw_view_destroy(struct vmw_resource *res)
 {
 	struct vmw_private *dev_priv = res->dev_priv;

 	mutex_lock(&dev_priv->binding_mutex);
 	WARN_ON(vmw_view_destroy(res));
 	res->id = -1;
 	mutex_unlock(&dev_priv->binding_mutex);
 }

 /**
  * vmw_view_key - Compute a view key suitable for the cmdbuf resource manager
  *
  * @user_key: The user-space id used for the view.
  * @view_type: The view type.
  *
  * Destroy a hardware view if it's still present.
  */
 static u32 vmw_view_key(u32 user_key, enum vmw_view_type view_type)
 {
 	return user_key | (view_type << 20);
 }

 /**
  * vmw_view_id_ok - Basic view id and type range checks.
  *
  * @user_key: The user-space id used for the view.
  * @view_type: The view type.
  *
  * Checks that the view id and type (typically provided by user-space) is
  * valid.
  */
 static bool vmw_view_id_ok(u32 user_key, enum vmw_view_type view_type)
 {
 	return (user_key < SVGA_COTABLE_MAX_IDS &&
 		view_type < vmw_view_max);
 }

 /**
  * vmw_view_res_free - resource res_free callback for view resources
  *
  * @res: Pointer to a struct vmw_resource
  *
  * Frees memory and memory accounting held by a struct vmw_view.
  */
 static void vmw_view_res_free(struct vmw_resource *res)
 {
 	struct vmw_view *view = vmw_view(res);
 	size_t size = offsetof(struct vmw_view, cmd) + view->cmd_size;
 	struct vmw_private *dev_priv = res->dev_priv;

 	vmw_resource_unreference(&view->cotable);
 	vmw_resource_unreference(&view->srf);
 	kfree_rcu(view, rcu);
 	ttm_mem_global_free(vmw_mem_glob(dev_priv), size);
 }

 /**
  * vmw_view_add - Create a view resource and stage it for addition
  * as a command buffer managed resource.
  *
  * @man: Pointer to the compat shader manager identifying the shader namespace.
  * @ctx: Pointer to a struct vmw_resource identifying the active context.
  * @srf: Pointer to a struct vmw_resource identifying the surface the view
  * points to.
  * @view_type: The view type deduced from the view create command.
  * @user_key: The key that is used to identify the shader. The key is
  * unique to the view type and to the context.
  * @cmd: Pointer to the view create command in the command stream.
  * @cmd_size: Size of the view create command in the command stream.
  * @list: Caller's list of staged command buffer resource actions.
  */
 int vmw_view_add(struct vmw_cmdbuf_res_manager *man,
 		 struct vmw_resource *ctx,
 		 struct vmw_resource *srf,
 		 enum vmw_view_type view_type,
 		 u32 user_key,
 		 const void *cmd,
 		 size_t cmd_size,
 		 struct list_head *list)
 {
 	static const size_t vmw_view_define_sizes[] = {
 		[vmw_view_sr] = sizeof(SVGA3dCmdDXDefineShaderResourceView),
 		[vmw_view_rt] = sizeof(SVGA3dCmdDXDefineRenderTargetView),
 		[vmw_view_ds] = sizeof(SVGA3dCmdDXDefineDepthStencilView)
 	};

 	struct vmw_private *dev_priv = ctx->dev_priv;
 	struct vmw_resource *res;
 	struct vmw_view *view;
 	struct ttm_operation_ctx ttm_opt_ctx = {
 		.interruptible = true,
 		.no_wait_gpu = false
 	};
 	size_t size;
 	int ret;

 	if (cmd_size != vmw_view_define_sizes[view_type] +
 	    sizeof(SVGA3dCmdHeader)) {
 		VMW_DEBUG_USER("Illegal view create command size.\n");
 		return -EINVAL;
 	}

 	if (!vmw_view_id_ok(user_key, view_type)) {
 		VMW_DEBUG_USER("Illegal view add view id.\n");
 		return -EINVAL;
 	}

 	size = offsetof(struct vmw_view, cmd) + cmd_size;

 	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv), size, &ttm_opt_ctx);
 	if (ret) {
 		if (ret != -ERESTARTSYS)
 			DRM_ERROR("Out of graphics memory for view creation\n");
 		return ret;
 	}

 	view = kmalloc(size, GFP_KERNEL);
 	if (!view) {
 		ttm_mem_global_free(vmw_mem_glob(dev_priv), size);
 		return -ENOMEM;
 	}

 	res = &view->res;
 	view->ctx = ctx;
 	view->srf = vmw_resource_reference(srf);
 	view->cotable = vmw_resource_reference
 		(vmw_context_cotable(ctx, vmw_view_cotables[view_type]));
 	view->view_type = view_type;
 	view->view_id = user_key;
 	view->cmd_size = cmd_size;
 	view->committed = false;
 	INIT_LIST_HEAD(&view->srf_head);
 	INIT_LIST_HEAD(&view->cotable_head);
 	memcpy(&view->cmd, cmd, cmd_size);
 	ret = vmw_resource_init(dev_priv, res, true,
 				vmw_view_res_free, &vmw_view_func);
 	if (ret)
 		goto out_resource_init;

 	ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_view,
 				 vmw_view_key(user_key, view_type),
 				 res, list);
 	if (ret)
 		goto out_resource_init;

 	res->id = view->view_id;
 	res->hw_destroy = vmw_hw_view_destroy;

 out_resource_init:
 	vmw_resource_unreference(&res);

 	return ret;
 }

 /**
  * vmw_view_remove - Stage a view for removal.
  *
  * @man: Pointer to the view manager identifying the shader namespace.
  * @user_key: The key that is used to identify the view. The key is
  * unique to the view type.
  * @view_type: View type
  * @list: Caller's list of staged command buffer resource actions.
  * @res_p: If the resource is in an already committed state, points to the
  * struct vmw_resource on successful return. The pointer will be
  * non ref-counted.
  */
 int vmw_view_remove(struct vmw_cmdbuf_res_manager *man,
 		    u32 user_key, enum vmw_view_type view_type,
 		    struct list_head *list,
 		    struct vmw_resource **res_p)
 {
 	if (!vmw_view_id_ok(user_key, view_type)) {
 		VMW_DEBUG_USER("Illegal view remove view id.\n");
 		return -EINVAL;
 	}

 	return vmw_cmdbuf_res_remove(man, vmw_cmdbuf_res_view,
 				     vmw_view_key(user_key, view_type),
 				     list, res_p);
 }

 /**
  * vmw_view_cotable_list_destroy - Evict all views belonging to a cotable.
  *
  * @dev_priv: Pointer to a device private struct.
  * @list: List of views belonging to a cotable.
  * @readback: Unused. Needed for function interface only.
  *
  * This function evicts all views belonging to a cotable.
  * It must be called with the binding_mutex held, and the caller must hold
  * a reference to the view resource. This is typically called before the
  * cotable is paged out.
  */
 void vmw_view_cotable_list_destroy(struct vmw_private *dev_priv,
 				   struct list_head *list,
 				   bool readback)
 {
 	struct vmw_view *entry, *next;

 	lockdep_assert_held_once(&dev_priv->binding_mutex);

 	list_for_each_entry_safe(entry, next, list, cotable_head)
 		WARN_ON(vmw_view_destroy(&entry->res));
 }

 /**
  * vmw_view_surface_list_destroy - Evict all views pointing to a surface
  *
  * @dev_priv: Pointer to a device private struct.
  * @list: List of views pointing to a surface.
  *
  * This function evicts all views pointing to a surface. This is typically
  * called before the surface is evicted.
  */
 void vmw_view_surface_list_destroy(struct vmw_private *dev_priv,
 				   struct list_head *list)
 {
 	struct vmw_view *entry, *next;

 	lockdep_assert_held_once(&dev_priv->binding_mutex);

 	list_for_each_entry_safe(entry, next, list, srf_head)
 		WARN_ON(vmw_view_destroy(&entry->res));
 }

 /**
  * vmw_view_srf - Return a non-refcounted pointer to the surface a view is
  * pointing to.
  *
  * @res: pointer to a view resource.
  *
  * Note that the view itself is holding a reference, so as long
  * the view resource is alive, the surface resource will be.
  */
 struct vmw_resource *vmw_view_srf(struct vmw_resource *res)
 {
 	return vmw_view(res)->srf;
 }

 /**
  * vmw_view_lookup - Look up a view.
  *
  * @man: The context's cmdbuf ref manager.
  * @view_type: The view type.
  * @user_key: The view user id.
  *
  * returns a refcounted pointer to a view or an error pointer if not found.
  */
 struct vmw_resource *vmw_view_lookup(struct vmw_cmdbuf_res_manager *man,
 				     enum vmw_view_type view_type,
 				     u32 user_key)
 {
 	return vmw_cmdbuf_res_lookup(man, vmw_cmdbuf_res_view,
 				     vmw_view_key(user_key, view_type));
 }

 /**
  * vmw_view_dirtying - Return whether a view type is dirtying its resource
  * @res: Pointer to the view
  *
  * Each time a resource is put on the validation list as the result of a
  * view pointing to it, we need to determine whether that resource will
  * be dirtied (written to by the GPU) as a result of the corresponding
  * GPU operation. Currently only rendertarget- and depth-stencil views are
  * capable of dirtying its resource.
  *
  * Return: Whether the view type of @res dirties the resource it points to.
  */
 u32 vmw_view_dirtying(struct vmw_resource *res)
 {
 	static u32 view_is_dirtying[vmw_view_max] = {
 		[vmw_view_rt] = VMW_RES_DIRTY_SET,
 		[vmw_view_ds] = VMW_RES_DIRTY_SET,
 	};

 	/* Update this function as we add more view types */
 	BUILD_BUG_ON(vmw_view_max != 3);
 	return view_is_dirtying[vmw_view(res)->view_type];
 }

 const u32 vmw_view_destroy_cmds[] = {
 	[vmw_view_sr] = SVGA_3D_CMD_DX_DESTROY_SHADERRESOURCE_VIEW,
 	[vmw_view_rt] = SVGA_3D_CMD_DX_DESTROY_RENDERTARGET_VIEW,
 	[vmw_view_ds] = SVGA_3D_CMD_DX_DESTROY_DEPTHSTENCIL_VIEW,
 };

 const SVGACOTableType vmw_view_cotables[] = {
 	[vmw_view_sr] = SVGA_COTABLE_SRVIEW,
 	[vmw_view_rt] = SVGA_COTABLE_RTVIEW,
 	[vmw_view_ds] = SVGA_COTABLE_DSVIEW,
 };

 const SVGACOTableType vmw_so_cotables[] = {
 	[vmw_so_el] = SVGA_COTABLE_ELEMENTLAYOUT,
 	[vmw_so_bs] = SVGA_COTABLE_BLENDSTATE,
 	[vmw_so_ds] = SVGA_COTABLE_DEPTHSTENCIL,
 	[vmw_so_rs] = SVGA_COTABLE_RASTERIZERSTATE,
 	[vmw_so_ss] = SVGA_COTABLE_SAMPLER,
 	[vmw_so_so] = SVGA_COTABLE_STREAMOUTPUT
 };


 /* To remove unused function warning */
 static void vmw_so_build_asserts(void) __attribute__((used));


 /*
  * This function is unused at run-time, and only used to dump various build
  * asserts important for code optimization assumptions.
  */
 static void vmw_so_build_asserts(void)
 {
 	/* Assert that our vmw_view_cmd_to_type() function is correct. */
 	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_SHADERRESOURCE_VIEW !=
 		     SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 1);
 	BUILD_BUG_ON(SVGA_3D_CMD_DX_DEFINE_RENDERTARGET_VIEW !=
 		     SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 2);
 	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_RENDERTARGET_VIEW !=
 		     SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 3);
 	BUILD_BUG_ON(SVGA_3D_CMD_DX_DEFINE_DEPTHSTENCIL_VIEW !=
 		     SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 4);
 	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_DEPTHSTENCIL_VIEW !=
 		     SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 5);

 	/* Assert that our "one body fits all" assumption is valid */
 	BUILD_BUG_ON(sizeof(union vmw_view_destroy) != sizeof(u32));

 	/* Assert that the view key space can hold all view ids. */
 	BUILD_BUG_ON(SVGA_COTABLE_MAX_IDS >= ((1 << 20) - 1));

 	/*
 	 * Assert that the offset of sid in all view define commands
 	 * is what we assume it to be.
 	 */
 	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
 		     offsetof(SVGA3dCmdDXDefineShaderResourceView, sid));
 	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
 		     offsetof(SVGA3dCmdDXDefineRenderTargetView, sid));
 	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
 		     offsetof(SVGA3dCmdDXDefineDepthStencilView, sid));
 }
	// SPDX-License-Identifier: GPL-2.0 OR MIT
	/**************************************************************************
	* Copyright 2014-2015 VMware, Inc., Palo Alto, CA., USA
	*
	* 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 "vmwgfx_drv.h"
	#include "vmwgfx_resource_priv.h"
	#include "vmwgfx_so.h"
	#include "vmwgfx_binding.h"

	/*
	* The currently only reason we need to keep track of views is that if we
	* destroy a hardware surface, all views pointing to it must also be destroyed,
	* otherwise the device will error.
	* So in particuar if a surface is evicted, we must destroy all views pointing
	* to it, and all context bindings of that view. Similarly we must restore
	* the view bindings, views and surfaces pointed to by the views when a
	* context is referenced in the command stream.
	*/

	/**
	* struct vmw_view - view metadata
	*
	* @res: The struct vmw_resource we derive from
	* @ctx: Non-refcounted pointer to the context this view belongs to.
	* @srf: Refcounted pointer to the surface pointed to by this view.
	* @cotable: Refcounted pointer to the cotable holding this view.
	* @srf_head: List head for the surface-to-view list.
	* @cotable_head: List head for the cotable-to_view list.
	* @view_type: View type.
	* @view_id: User-space per context view id. Currently used also as per
	* context device view id.
	* @cmd_size: Size of the SVGA3D define view command that we've copied from the
	* command stream.
	* @committed: Whether the view is actually created or pending creation at the
	* device level.
	* @cmd: The SVGA3D define view command copied from the command stream.
	*/
	struct vmw_view {
	struct rcu_head rcu;
	struct vmw_resource res;
	struct vmw_resource ctx; / Immutable */
	struct vmw_resource srf; / Immutable */
	struct vmw_resource cotable; / Immutable */
	struct list_head srf_head; /* Protected by binding_mutex */
	struct list_head cotable_head; /* Protected by binding_mutex */
	unsigned view_type; /* Immutable */
	unsigned view_id; /* Immutable */
	u32 cmd_size; /* Immutable */
	bool committed; /* Protected by binding_mutex */
	u32 cmd[1]; /* Immutable */
	};

	static int vmw_view_create(struct vmw_resource *res);
	static int vmw_view_destroy(struct vmw_resource *res);
	static void vmw_hw_view_destroy(struct vmw_resource *res);
	static void vmw_view_commit_notify(struct vmw_resource *res,
	enum vmw_cmdbuf_res_state state);

	static const struct vmw_res_func vmw_view_func = {
	.res_type = vmw_res_view,
	.needs_backup = false,
	.may_evict = false,
	.type_name = "DX view",
	.backup_placement = NULL,
	.create = vmw_view_create,
	.commit_notify = vmw_view_commit_notify,
	};

	/**
	* struct vmw_view - view define command body stub
	*
	* @view_id: The device id of the view being defined
	* @sid: The surface id of the view being defined
	*
	* This generic struct is used by the code to change @view_id and @sid of a
	* saved view define command.
	*/
	struct vmw_view_define {
	uint32 view_id;
	uint32 sid;
	};

	/**
	* vmw_view - Convert a struct vmw_resource to a struct vmw_view
	*
	* @res: Pointer to the resource to convert.
	*
	* Returns a pointer to a struct vmw_view.
	*/
	static struct vmw_view vmw_view(struct vmw_resource res)
	{
	return container_of(res, struct vmw_view, res);
	}

	/**
	* vmw_view_commit_notify - Notify that a view operation has been committed to
	* hardware from a user-supplied command stream.
	*
	* @res: Pointer to the view resource.
	* @state: Indicating whether a creation or removal has been committed.
	*
	*/
	static void vmw_view_commit_notify(struct vmw_resource *res,
	enum vmw_cmdbuf_res_state state)
	{
	struct vmw_view *view = vmw_view(res);
	struct vmw_private *dev_priv = res->dev_priv;

	mutex_lock(&dev_priv->binding_mutex);
	if (state == VMW_CMDBUF_RES_ADD) {
	struct vmw_surface *srf = vmw_res_to_srf(view->srf);

	list_add_tail(&view->srf_head, &srf->view_list);
	vmw_cotable_add_resource(view->cotable, &view->cotable_head);
	view->committed = true;
	res->id = view->view_id;

	} else {
	list_del_init(&view->cotable_head);
	list_del_init(&view->srf_head);
	view->committed = false;
	res->id = -1;
	}
	mutex_unlock(&dev_priv->binding_mutex);
	}

	/**
	* vmw_view_create - Create a hardware view.
	*
	* @res: Pointer to the view resource.
	*
	* Create a hardware view. Typically used if that view has previously been
	* destroyed by an eviction operation.
	*/
	static int vmw_view_create(struct vmw_resource *res)
	{
	struct vmw_view *view = vmw_view(res);
	struct vmw_surface *srf = vmw_res_to_srf(view->srf);
	struct vmw_private *dev_priv = res->dev_priv;
	struct {
	SVGA3dCmdHeader header;
	struct vmw_view_define body;
	} *cmd;

	mutex_lock(&dev_priv->binding_mutex);
	if (!view->committed) {
	mutex_unlock(&dev_priv->binding_mutex);
	return 0;
	}

	cmd = VMW_FIFO_RESERVE_DX(res->dev_priv, view->cmd_size, view->ctx->id);
	if (!cmd) {
	mutex_unlock(&dev_priv->binding_mutex);
	return -ENOMEM;
	}

	memcpy(cmd, &view->cmd, view->cmd_size);
	WARN_ON(cmd->body.view_id != view->view_id);
	/* Sid may have changed due to surface eviction. */
	WARN_ON(view->srf->id == SVGA3D_INVALID_ID);
	cmd->body.sid = view->srf->id;
	vmw_fifo_commit(res->dev_priv, view->cmd_size);
	res->id = view->view_id;
	list_add_tail(&view->srf_head, &srf->view_list);
	vmw_cotable_add_resource(view->cotable, &view->cotable_head);
	mutex_unlock(&dev_priv->binding_mutex);

	return 0;
	}

	/**
	* vmw_view_destroy - Destroy a hardware view.
	*
	* @res: Pointer to the view resource.
	*
	* Destroy a hardware view. Typically used on unexpected termination of the
	* owning process or if the surface the view is pointing to is destroyed.
	*/
	static int vmw_view_destroy(struct vmw_resource *res)
	{
	struct vmw_private *dev_priv = res->dev_priv;
	struct vmw_view *view = vmw_view(res);
	struct {
	SVGA3dCmdHeader header;
	union vmw_view_destroy body;
	} *cmd;

	lockdep_assert_held_once(&dev_priv->binding_mutex);
	vmw_binding_res_list_scrub(&res->binding_head);

	if (!view->committed \|\| res->id == -1)
	return 0;

	cmd = VMW_FIFO_RESERVE_DX(dev_priv, sizeof(*cmd), view->ctx->id);
	if (!cmd)
	return -ENOMEM;

	cmd->header.id = vmw_view_destroy_cmds[view->view_type];
	cmd->header.size = sizeof(cmd->body);
	cmd->body.view_id = view->view_id;
	vmw_fifo_commit(dev_priv, sizeof(*cmd));
	res->id = -1;
	list_del_init(&view->cotable_head);
	list_del_init(&view->srf_head);

	return 0;
	}

	/**
	* vmw_hw_view_destroy - Destroy a hardware view as part of resource cleanup.
	*
	* @res: Pointer to the view resource.
	*
	* Destroy a hardware view if it's still present.
	*/
	static void vmw_hw_view_destroy(struct vmw_resource *res)
	{
	struct vmw_private *dev_priv = res->dev_priv;

	mutex_lock(&dev_priv->binding_mutex);
	WARN_ON(vmw_view_destroy(res));
	res->id = -1;
	mutex_unlock(&dev_priv->binding_mutex);
	}

	/**
	* vmw_view_key - Compute a view key suitable for the cmdbuf resource manager
	*
	* @user_key: The user-space id used for the view.
	* @view_type: The view type.
	*
	* Destroy a hardware view if it's still present.
	*/
	static u32 vmw_view_key(u32 user_key, enum vmw_view_type view_type)
	{
	return user_key \| (view_type << 20);
	}

	/**
	* vmw_view_id_ok - Basic view id and type range checks.
	*
	* @user_key: The user-space id used for the view.
	* @view_type: The view type.
	*
	* Checks that the view id and type (typically provided by user-space) is
	* valid.
	*/
	static bool vmw_view_id_ok(u32 user_key, enum vmw_view_type view_type)
	{
	return (user_key < SVGA_COTABLE_MAX_IDS &&
	view_type < vmw_view_max);
	}

	/**
	* vmw_view_res_free - resource res_free callback for view resources
	*
	* @res: Pointer to a struct vmw_resource
	*
	* Frees memory and memory accounting held by a struct vmw_view.
	*/
	static void vmw_view_res_free(struct vmw_resource *res)
	{
	struct vmw_view *view = vmw_view(res);
	size_t size = offsetof(struct vmw_view, cmd) + view->cmd_size;
	struct vmw_private *dev_priv = res->dev_priv;

	vmw_resource_unreference(&view->cotable);
	vmw_resource_unreference(&view->srf);
	kfree_rcu(view, rcu);
	ttm_mem_global_free(vmw_mem_glob(dev_priv), size);
	}

	/**
	* vmw_view_add - Create a view resource and stage it for addition
	* as a command buffer managed resource.
	*
	* @man: Pointer to the compat shader manager identifying the shader namespace.
	* @ctx: Pointer to a struct vmw_resource identifying the active context.
	* @srf: Pointer to a struct vmw_resource identifying the surface the view
	* points to.
	* @view_type: The view type deduced from the view create command.
	* @user_key: The key that is used to identify the shader. The key is
	* unique to the view type and to the context.
	* @cmd: Pointer to the view create command in the command stream.
	* @cmd_size: Size of the view create command in the command stream.
	* @list: Caller's list of staged command buffer resource actions.
	*/
	int vmw_view_add(struct vmw_cmdbuf_res_manager *man,
	struct vmw_resource *ctx,
	struct vmw_resource *srf,
	enum vmw_view_type view_type,
	u32 user_key,
	const void *cmd,
	size_t cmd_size,
	struct list_head *list)
	{
	static const size_t vmw_view_define_sizes[] = {
	[vmw_view_sr] = sizeof(SVGA3dCmdDXDefineShaderResourceView),
	[vmw_view_rt] = sizeof(SVGA3dCmdDXDefineRenderTargetView),
	[vmw_view_ds] = sizeof(SVGA3dCmdDXDefineDepthStencilView)
	};

	struct vmw_private *dev_priv = ctx->dev_priv;
	struct vmw_resource *res;
	struct vmw_view *view;
	struct ttm_operation_ctx ttm_opt_ctx = {
	.interruptible = true,
	.no_wait_gpu = false
	};
	size_t size;
	int ret;

	if (cmd_size != vmw_view_define_sizes[view_type] +
	sizeof(SVGA3dCmdHeader)) {
	VMW_DEBUG_USER("Illegal view create command size.\n");
	return -EINVAL;
	}

	if (!vmw_view_id_ok(user_key, view_type)) {
	VMW_DEBUG_USER("Illegal view add view id.\n");
	return -EINVAL;
	}

	size = offsetof(struct vmw_view, cmd) + cmd_size;

	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv), size, &ttm_opt_ctx);
	if (ret) {
	if (ret != -ERESTARTSYS)
	DRM_ERROR("Out of graphics memory for view creation\n");
	return ret;
	}

	view = kmalloc(size, GFP_KERNEL);
	if (!view) {
	ttm_mem_global_free(vmw_mem_glob(dev_priv), size);
	return -ENOMEM;
	}

	res = &view->res;
	view->ctx = ctx;
	view->srf = vmw_resource_reference(srf);
	view->cotable = vmw_resource_reference
	(vmw_context_cotable(ctx, vmw_view_cotables[view_type]));
	view->view_type = view_type;
	view->view_id = user_key;
	view->cmd_size = cmd_size;
	view->committed = false;
	INIT_LIST_HEAD(&view->srf_head);
	INIT_LIST_HEAD(&view->cotable_head);
	memcpy(&view->cmd, cmd, cmd_size);
	ret = vmw_resource_init(dev_priv, res, true,
	vmw_view_res_free, &vmw_view_func);
	if (ret)
	goto out_resource_init;

	ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_view,
	vmw_view_key(user_key, view_type),
	res, list);
	if (ret)
	goto out_resource_init;

	res->id = view->view_id;
	res->hw_destroy = vmw_hw_view_destroy;

	out_resource_init:
	vmw_resource_unreference(&res);

	return ret;
	}

	/**
	* vmw_view_remove - Stage a view for removal.
	*
	* @man: Pointer to the view manager identifying the shader namespace.
	* @user_key: The key that is used to identify the view. The key is
	* unique to the view type.
	* @view_type: View type
	* @list: Caller's list of staged command buffer resource actions.
	* @res_p: If the resource is in an already committed state, points to the
	* struct vmw_resource on successful return. The pointer will be
	* non ref-counted.
	*/
	int vmw_view_remove(struct vmw_cmdbuf_res_manager *man,
	u32 user_key, enum vmw_view_type view_type,
	struct list_head *list,
	struct vmw_resource **res_p)
	{
	if (!vmw_view_id_ok(user_key, view_type)) {
	VMW_DEBUG_USER("Illegal view remove view id.\n");
	return -EINVAL;
	}

	return vmw_cmdbuf_res_remove(man, vmw_cmdbuf_res_view,
	vmw_view_key(user_key, view_type),
	list, res_p);
	}

	/**
	* vmw_view_cotable_list_destroy - Evict all views belonging to a cotable.
	*
	* @dev_priv: Pointer to a device private struct.
	* @list: List of views belonging to a cotable.
	* @readback: Unused. Needed for function interface only.
	*
	* This function evicts all views belonging to a cotable.
	* It must be called with the binding_mutex held, and the caller must hold
	* a reference to the view resource. This is typically called before the
	* cotable is paged out.
	*/
	void vmw_view_cotable_list_destroy(struct vmw_private *dev_priv,
	struct list_head *list,
	bool readback)
	{
	struct vmw_view entry, next;

	lockdep_assert_held_once(&dev_priv->binding_mutex);

	list_for_each_entry_safe(entry, next, list, cotable_head)
	WARN_ON(vmw_view_destroy(&entry->res));
	}

	/**
	* vmw_view_surface_list_destroy - Evict all views pointing to a surface
	*
	* @dev_priv: Pointer to a device private struct.
	* @list: List of views pointing to a surface.
	*
	* This function evicts all views pointing to a surface. This is typically
	* called before the surface is evicted.
	*/
	void vmw_view_surface_list_destroy(struct vmw_private *dev_priv,
	struct list_head *list)
	{
	struct vmw_view entry, next;

	lockdep_assert_held_once(&dev_priv->binding_mutex);

	list_for_each_entry_safe(entry, next, list, srf_head)
	WARN_ON(vmw_view_destroy(&entry->res));
	}

	/**
	* vmw_view_srf - Return a non-refcounted pointer to the surface a view is
	* pointing to.
	*
	* @res: pointer to a view resource.
	*
	* Note that the view itself is holding a reference, so as long
	* the view resource is alive, the surface resource will be.
	*/
	struct vmw_resource vmw_view_srf(struct vmw_resource res)
	{
	return vmw_view(res)->srf;
	}

	/**
	* vmw_view_lookup - Look up a view.
	*
	* @man: The context's cmdbuf ref manager.
	* @view_type: The view type.
	* @user_key: The view user id.
	*
	* returns a refcounted pointer to a view or an error pointer if not found.
	*/
	struct vmw_resource vmw_view_lookup(struct vmw_cmdbuf_res_manager man,
	enum vmw_view_type view_type,
	u32 user_key)
	{
	return vmw_cmdbuf_res_lookup(man, vmw_cmdbuf_res_view,
	vmw_view_key(user_key, view_type));
	}

	/**
	* vmw_view_dirtying - Return whether a view type is dirtying its resource
	* @res: Pointer to the view
	*
	* Each time a resource is put on the validation list as the result of a
	* view pointing to it, we need to determine whether that resource will
	* be dirtied (written to by the GPU) as a result of the corresponding
	* GPU operation. Currently only rendertarget- and depth-stencil views are
	* capable of dirtying its resource.
	*
	* Return: Whether the view type of @res dirties the resource it points to.
	*/
	u32 vmw_view_dirtying(struct vmw_resource *res)
	{
	static u32 view_is_dirtying[vmw_view_max] = {
	[vmw_view_rt] = VMW_RES_DIRTY_SET,
	[vmw_view_ds] = VMW_RES_DIRTY_SET,
	};

	/* Update this function as we add more view types */
	BUILD_BUG_ON(vmw_view_max != 3);
	return view_is_dirtying[vmw_view(res)->view_type];
	}

	const u32 vmw_view_destroy_cmds[] = {
	[vmw_view_sr] = SVGA_3D_CMD_DX_DESTROY_SHADERRESOURCE_VIEW,
	[vmw_view_rt] = SVGA_3D_CMD_DX_DESTROY_RENDERTARGET_VIEW,
	[vmw_view_ds] = SVGA_3D_CMD_DX_DESTROY_DEPTHSTENCIL_VIEW,
	};

	const SVGACOTableType vmw_view_cotables[] = {
	[vmw_view_sr] = SVGA_COTABLE_SRVIEW,
	[vmw_view_rt] = SVGA_COTABLE_RTVIEW,
	[vmw_view_ds] = SVGA_COTABLE_DSVIEW,
	};

	const SVGACOTableType vmw_so_cotables[] = {
	[vmw_so_el] = SVGA_COTABLE_ELEMENTLAYOUT,
	[vmw_so_bs] = SVGA_COTABLE_BLENDSTATE,
	[vmw_so_ds] = SVGA_COTABLE_DEPTHSTENCIL,
	[vmw_so_rs] = SVGA_COTABLE_RASTERIZERSTATE,
	[vmw_so_ss] = SVGA_COTABLE_SAMPLER,
	[vmw_so_so] = SVGA_COTABLE_STREAMOUTPUT
	};


	/* To remove unused function warning */
	static void vmw_so_build_asserts(void) __attribute__((used));


	/*
	* This function is unused at run-time, and only used to dump various build
	* asserts important for code optimization assumptions.
	*/
	static void vmw_so_build_asserts(void)
	{
	/* Assert that our vmw_view_cmd_to_type() function is correct. */
	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_SHADERRESOURCE_VIEW !=
	SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 1);
	BUILD_BUG_ON(SVGA_3D_CMD_DX_DEFINE_RENDERTARGET_VIEW !=
	SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 2);
	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_RENDERTARGET_VIEW !=
	SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 3);
	BUILD_BUG_ON(SVGA_3D_CMD_DX_DEFINE_DEPTHSTENCIL_VIEW !=
	SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 4);
	BUILD_BUG_ON(SVGA_3D_CMD_DX_DESTROY_DEPTHSTENCIL_VIEW !=
	SVGA_3D_CMD_DX_DEFINE_SHADERRESOURCE_VIEW + 5);

	/* Assert that our "one body fits all" assumption is valid */
	BUILD_BUG_ON(sizeof(union vmw_view_destroy) != sizeof(u32));

	/* Assert that the view key space can hold all view ids. */
	BUILD_BUG_ON(SVGA_COTABLE_MAX_IDS >= ((1 << 20) - 1));

	/*
	* Assert that the offset of sid in all view define commands
	* is what we assume it to be.
	*/
	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
	offsetof(SVGA3dCmdDXDefineShaderResourceView, sid));
	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
	offsetof(SVGA3dCmdDXDefineRenderTargetView, sid));
	BUILD_BUG_ON(offsetof(struct vmw_view_define, sid) !=
	offsetof(SVGA3dCmdDXDefineDepthStencilView, sid));
	}