text: // 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"
  
  #define VMW_CMDBUF_RES_MAN_HT_ORDER 12
  
  /**
   * struct vmw_cmdbuf_res - Command buffer managed resource entry.
   *
   * @res: Refcounted pointer to a struct vmw_resource.
   * @hash: Hash entry for the manager hash table.
   * @head: List head used either by the staging list or the manager list
   * of commited resources.
   * @state: Staging state of this resource entry.
   * @man: Pointer to a resource manager for this entry.
   */
  struct vmw_cmdbuf_res {
  	struct vmw_resource *res;
  	struct drm_hash_item hash;
  	struct list_head head;
  	enum vmw_cmdbuf_res_state state;
  	struct vmw_cmdbuf_res_manager *man;
  };
  
  /**
   * struct vmw_cmdbuf_res_manager - Command buffer resource manager.
   *
   * @resources: Hash table containing staged and commited command buffer
   * resources
   * @list: List of commited command buffer resources.
   * @dev_priv: Pointer to a device private structure.
   *
   * @resources and @list are protected by the cmdbuf mutex for now.
   */
  struct vmw_cmdbuf_res_manager {
  	struct drm_open_hash resources;
  	struct list_head list;
  	struct vmw_private *dev_priv;
  };
  
  
  /**
   * vmw_cmdbuf_res_lookup - Look up a command buffer resource
   *
   * @man: Pointer to the command buffer resource manager
   * @resource_type: The resource type, that combined with the user key
   * identifies the resource.
   * @user_key: The user key.
   *
   * Returns a valid refcounted struct vmw_resource pointer on success,
   * an error pointer on failure.
   */
  struct vmw_resource *
  vmw_cmdbuf_res_lookup(struct vmw_cmdbuf_res_manager *man,
  		      enum vmw_cmdbuf_res_type res_type,
  		      u32 user_key)
  {
  	struct drm_hash_item *hash;
  	int ret;
  	unsigned long key = user_key | (res_type << 24);
  
  	ret = drm_ht_find_item(&man->resources, key, &hash);
  	if (unlikely(ret != 0))
  		return ERR_PTR(ret);
  
  	return drm_hash_entry(hash, struct vmw_cmdbuf_res, hash)->res;
  }
  
  /**
   * vmw_cmdbuf_res_free - Free a command buffer resource.
   *
   * @man: Pointer to the command buffer resource manager
   * @entry: Pointer to a struct vmw_cmdbuf_res.
   *
   * Frees a struct vmw_cmdbuf_res entry and drops its reference to the
   * struct vmw_resource.
   */
  static void vmw_cmdbuf_res_free(struct vmw_cmdbuf_res_manager *man,
  				struct vmw_cmdbuf_res *entry)
  {
  	list_del(&entry->head);
  	WARN_ON(drm_ht_remove_item(&man->resources, &entry->hash));
  	vmw_resource_unreference(&entry->res);
  	kfree(entry);
  }
  
  /**
   * vmw_cmdbuf_res_commit - Commit a list of command buffer resource actions
   *
   * @list: Caller's list of command buffer resource actions.
   *
   * This function commits a list of command buffer resource
   * additions or removals.
   * It is typically called when the execbuf ioctl call triggering these
   * actions has commited the fifo contents to the device.
   */
  void vmw_cmdbuf_res_commit(struct list_head *list)
  {
  	struct vmw_cmdbuf_res *entry, *next;
  
  	list_for_each_entry_safe(entry, next, list, head) {
  		list_del(&entry->head);
  		if (entry->res->func->commit_notify)
  			entry->res->func->commit_notify(entry->res,
  							entry->state);
  		switch (entry->state) {
  		case VMW_CMDBUF_RES_ADD:
  			entry->state = VMW_CMDBUF_RES_COMMITTED;
  			list_add_tail(&entry->head, &entry->man->list);
  			break;
  		case VMW_CMDBUF_RES_DEL:
  			vmw_resource_unreference(&entry->res);
  			kfree(entry);
  			break;
  		default:
  			BUG();
  			break;
  		}
  	}
  }
  
  /**
   * vmw_cmdbuf_res_revert - Revert a list of command buffer resource actions
   *
   * @man: Pointer to the command buffer resource manager
   * @list: Caller's list of command buffer resource action
   *
   * This function reverts a list of command buffer resource
   * additions or removals.
   * It is typically called when the execbuf ioctl call triggering these
   * actions failed for some reason, and the command stream was never
   * submitted.
   */
  void vmw_cmdbuf_res_revert(struct list_head *list)
  {
  	struct vmw_cmdbuf_res *entry, *next;
  	int ret;
  
  	list_for_each_entry_safe(entry, next, list, head) {
  		switch (entry->state) {
  		case VMW_CMDBUF_RES_ADD:
  			vmw_cmdbuf_res_free(entry->man, entry);
  			break;
  		case VMW_CMDBUF_RES_DEL:
  			ret = drm_ht_insert_item(&entry->man->resources,
  						 &entry->hash);
  			list_del(&entry->head);
  			list_add_tail(&entry->head, &entry->man->list);
  			entry->state = VMW_CMDBUF_RES_COMMITTED;
  			break;
  		default:
  			BUG();
  			break;
  		}
  	}
  }
  
  /**
   * vmw_cmdbuf_res_add - Stage a command buffer managed resource for addition.
   *
   * @man: Pointer to the command buffer resource manager.
   * @res_type: The resource type.
   * @user_key: The user-space id of the resource.
   * @res: Valid (refcount != 0) pointer to a struct vmw_resource.
   * @list: The staging list.
   *
   * This function allocates a struct vmw_cmdbuf_res entry and adds the
   * resource to the hash table of the manager identified by @man. The
   * entry is then put on the staging list identified by @list.
   */
  int vmw_cmdbuf_res_add(struct vmw_cmdbuf_res_manager *man,
  		       enum vmw_cmdbuf_res_type res_type,
  		       u32 user_key,
  		       struct vmw_resource *res,
  		       struct list_head *list)
  {
  	struct vmw_cmdbuf_res *cres;
  	int ret;
  
  	cres = kzalloc(sizeof(*cres), GFP_KERNEL);
  	if (unlikely(!cres))
  		return -ENOMEM;
  
  	cres->hash.key = user_key | (res_type << 24);
  	ret = drm_ht_insert_item(&man->resources, &cres->hash);
  	if (unlikely(ret != 0)) {
  		kfree(cres);
  		goto out_invalid_key;
  	}
  
  	cres->state = VMW_CMDBUF_RES_ADD;
  	cres->res = vmw_resource_reference(res);
  	cres->man = man;
  	list_add_tail(&cres->head, list);
  
  out_invalid_key:
  	return ret;
  }
  
  /**
   * vmw_cmdbuf_res_remove - Stage a command buffer managed resource for removal.
   *
   * @man: Pointer to the command buffer resource manager.
   * @res_type: The resource type.
   * @user_key: The user-space id of the resource.
   * @list: The staging list.
   * @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.
   *
   * This function looks up the struct vmw_cmdbuf_res entry from the manager
   * hash table and, if it exists, removes it. Depending on its current staging
   * state it then either removes the entry from the staging list or adds it
   * to it with a staging state of removal.
   */
  int vmw_cmdbuf_res_remove(struct vmw_cmdbuf_res_manager *man,
  			  enum vmw_cmdbuf_res_type res_type,
  			  u32 user_key,
  			  struct list_head *list,
  			  struct vmw_resource **res_p)
  {
  	struct vmw_cmdbuf_res *entry;
  	struct drm_hash_item *hash;
  	int ret;
  
  	ret = drm_ht_find_item(&man->resources, user_key | (res_type << 24),
  			       &hash);
  	if (likely(ret != 0))
  		return -EINVAL;
  
  	entry = drm_hash_entry(hash, struct vmw_cmdbuf_res, hash);
  
  	switch (entry->state) {
  	case VMW_CMDBUF_RES_ADD:
  		vmw_cmdbuf_res_free(man, entry);
  		*res_p = NULL;
  		break;
  	case VMW_CMDBUF_RES_COMMITTED:
  		(void) drm_ht_remove_item(&man->resources, &entry->hash);
  		list_del(&entry->head);
  		entry->state = VMW_CMDBUF_RES_DEL;
  		list_add_tail(&entry->head, list);
  		*res_p = entry->res;
  		break;
  	default:
  		BUG();
  		break;
  	}
  
  	return 0;
  }
  
  /**
   * vmw_cmdbuf_res_man_create - Allocate a command buffer managed resource
   * manager.
   *
   * @dev_priv: Pointer to a struct vmw_private
   *
   * Allocates and initializes a command buffer managed resource manager. Returns
   * an error pointer on failure.
   */
  struct vmw_cmdbuf_res_manager *
  vmw_cmdbuf_res_man_create(struct vmw_private *dev_priv)
  {
  	struct vmw_cmdbuf_res_manager *man;
  	int ret;
  
  	man = kzalloc(sizeof(*man), GFP_KERNEL);
  	if (!man)
  		return ERR_PTR(-ENOMEM);
  
  	man->dev_priv = dev_priv;
  	INIT_LIST_HEAD(&man->list);
  	ret = drm_ht_create(&man->resources, VMW_CMDBUF_RES_MAN_HT_ORDER);
  	if (ret == 0)
  		return man;
  
  	kfree(man);
  	return ERR_PTR(ret);
  }
  
  /**
   * vmw_cmdbuf_res_man_destroy - Destroy a command buffer managed resource
   * manager.
   *
   * @man: Pointer to the  manager to destroy.
   *
   * This function destroys a command buffer managed resource manager and
   * unreferences / frees all command buffer managed resources and -entries
   * associated with it.
   */
  void vmw_cmdbuf_res_man_destroy(struct vmw_cmdbuf_res_manager *man)
  {
  	struct vmw_cmdbuf_res *entry, *next;
  
  	list_for_each_entry_safe(entry, next, &man->list, head)
  		vmw_cmdbuf_res_free(man, entry);
  
  	drm_ht_remove(&man->resources);
  	kfree(man);
  }
  
  /**
   *
   * vmw_cmdbuf_res_man_size - Return the size of a command buffer managed
   * resource manager
   *
   * Returns the approximate allocation size of a command buffer managed
   * resource manager.
   */
  size_t vmw_cmdbuf_res_man_size(void)
  {
  	static size_t res_man_size;
  
  	if (unlikely(res_man_size == 0))
  		res_man_size =
  			ttm_round_pot(sizeof(struct vmw_cmdbuf_res_manager)) +
  			ttm_round_pot(sizeof(struct hlist_head) <<
  				      VMW_CMDBUF_RES_MAN_HT_ORDER);
  
  	return res_man_size;
  }
  