xref: /linux/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c (revision 43531dc661b7fb6be249c023bf25847b38215545)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /**************************************************************************
3  *
4  * Copyright 2014-2022 VMware, Inc., Palo Alto, CA., USA
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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26  **************************************************************************/
27 
28 #include "vmwgfx_drv.h"
29 #include "vmwgfx_resource_priv.h"
30 
31 #include <linux/hashtable.h>
32 
33 #define VMW_CMDBUF_RES_MAN_HT_ORDER 12
34 
35 /**
36  * struct vmw_cmdbuf_res - Command buffer managed resource entry.
37  *
38  * @res: Refcounted pointer to a struct vmw_resource.
39  * @hash: Hash entry for the manager hash table.
40  * @head: List head used either by the staging list or the manager list
41  * of committed resources.
42  * @state: Staging state of this resource entry.
43  * @man: Pointer to a resource manager for this entry.
44  */
45 struct vmw_cmdbuf_res {
46 	struct vmw_resource *res;
47 	struct vmwgfx_hash_item hash;
48 	struct list_head head;
49 	enum vmw_cmdbuf_res_state state;
50 	struct vmw_cmdbuf_res_manager *man;
51 };
52 
53 /**
54  * struct vmw_cmdbuf_res_manager - Command buffer resource manager.
55  *
56  * @resources: Hash table containing staged and committed command buffer
57  * resources
58  * @list: List of committed command buffer resources.
59  * @dev_priv: Pointer to a device private structure.
60  *
61  * @resources and @list are protected by the cmdbuf mutex for now.
62  */
63 struct vmw_cmdbuf_res_manager {
64 	DECLARE_HASHTABLE(resources, VMW_CMDBUF_RES_MAN_HT_ORDER);
65 	struct list_head list;
66 	struct vmw_private *dev_priv;
67 };
68 
69 
70 /**
71  * vmw_cmdbuf_res_lookup - Look up a command buffer resource
72  *
73  * @man: Pointer to the command buffer resource manager
74  * @res_type: The resource type, that combined with the user key
75  * identifies the resource.
76  * @user_key: The user key.
77  *
78  * Returns a valid refcounted struct vmw_resource pointer on success,
79  * an error pointer on failure.
80  */
81 struct vmw_resource *
82 vmw_cmdbuf_res_lookup(struct vmw_cmdbuf_res_manager *man,
83 		      enum vmw_cmdbuf_res_type res_type,
84 		      u32 user_key)
85 {
86 	struct vmwgfx_hash_item *hash;
87 	unsigned long key = user_key | (res_type << 24);
88 
89 	hash_for_each_possible_rcu(man->resources, hash, head, key) {
90 		if (hash->key == key)
91 			return drm_hash_entry(hash, struct vmw_cmdbuf_res, hash)->res;
92 	}
93 	return ERR_PTR(-EINVAL);
94 }
95 
96 /**
97  * vmw_cmdbuf_res_free - Free a command buffer resource.
98  *
99  * @man: Pointer to the command buffer resource manager
100  * @entry: Pointer to a struct vmw_cmdbuf_res.
101  *
102  * Frees a struct vmw_cmdbuf_res entry and drops its reference to the
103  * struct vmw_resource.
104  */
105 static void vmw_cmdbuf_res_free(struct vmw_cmdbuf_res_manager *man,
106 				struct vmw_cmdbuf_res *entry)
107 {
108 	list_del(&entry->head);
109 	hash_del_rcu(&entry->hash.head);
110 	vmw_resource_unreference(&entry->res);
111 	kfree(entry);
112 }
113 
114 /**
115  * vmw_cmdbuf_res_commit - Commit a list of command buffer resource actions
116  *
117  * @list: Caller's list of command buffer resource actions.
118  *
119  * This function commits a list of command buffer resource
120  * additions or removals.
121  * It is typically called when the execbuf ioctl call triggering these
122  * actions has committed the fifo contents to the device.
123  */
124 void vmw_cmdbuf_res_commit(struct list_head *list)
125 {
126 	struct vmw_cmdbuf_res *entry, *next;
127 
128 	list_for_each_entry_safe(entry, next, list, head) {
129 		list_del(&entry->head);
130 		if (entry->res->func->commit_notify)
131 			entry->res->func->commit_notify(entry->res,
132 							entry->state);
133 		switch (entry->state) {
134 		case VMW_CMDBUF_RES_ADD:
135 			entry->state = VMW_CMDBUF_RES_COMMITTED;
136 			list_add_tail(&entry->head, &entry->man->list);
137 			break;
138 		case VMW_CMDBUF_RES_DEL:
139 			vmw_resource_unreference(&entry->res);
140 			kfree(entry);
141 			break;
142 		default:
143 			BUG();
144 			break;
145 		}
146 	}
147 }
148 
149 /**
150  * vmw_cmdbuf_res_revert - Revert a list of command buffer resource actions
151  *
152  * @list: Caller's list of command buffer resource action
153  *
154  * This function reverts a list of command buffer resource
155  * additions or removals.
156  * It is typically called when the execbuf ioctl call triggering these
157  * actions failed for some reason, and the command stream was never
158  * submitted.
159  */
160 void vmw_cmdbuf_res_revert(struct list_head *list)
161 {
162 	struct vmw_cmdbuf_res *entry, *next;
163 
164 	list_for_each_entry_safe(entry, next, list, head) {
165 		switch (entry->state) {
166 		case VMW_CMDBUF_RES_ADD:
167 			vmw_cmdbuf_res_free(entry->man, entry);
168 			break;
169 		case VMW_CMDBUF_RES_DEL:
170 			hash_add_rcu(entry->man->resources, &entry->hash.head,
171 						entry->hash.key);
172 			list_move_tail(&entry->head, &entry->man->list);
173 			entry->state = VMW_CMDBUF_RES_COMMITTED;
174 			break;
175 		default:
176 			BUG();
177 			break;
178 		}
179 	}
180 }
181 
182 /**
183  * vmw_cmdbuf_res_add - Stage a command buffer managed resource for addition.
184  *
185  * @man: Pointer to the command buffer resource manager.
186  * @res_type: The resource type.
187  * @user_key: The user-space id of the resource.
188  * @res: Valid (refcount != 0) pointer to a struct vmw_resource.
189  * @list: The staging list.
190  *
191  * This function allocates a struct vmw_cmdbuf_res entry and adds the
192  * resource to the hash table of the manager identified by @man. The
193  * entry is then put on the staging list identified by @list.
194  */
195 int vmw_cmdbuf_res_add(struct vmw_cmdbuf_res_manager *man,
196 		       enum vmw_cmdbuf_res_type res_type,
197 		       u32 user_key,
198 		       struct vmw_resource *res,
199 		       struct list_head *list)
200 {
201 	struct vmw_cmdbuf_res *cres;
202 
203 	cres = kzalloc(sizeof(*cres), GFP_KERNEL);
204 	if (unlikely(!cres))
205 		return -ENOMEM;
206 
207 	cres->hash.key = user_key | (res_type << 24);
208 	hash_add_rcu(man->resources, &cres->hash.head, cres->hash.key);
209 
210 	cres->state = VMW_CMDBUF_RES_ADD;
211 	cres->res = vmw_resource_reference(res);
212 	cres->man = man;
213 	list_add_tail(&cres->head, list);
214 
215 	return 0;
216 }
217 
218 /**
219  * vmw_cmdbuf_res_remove - Stage a command buffer managed resource for removal.
220  *
221  * @man: Pointer to the command buffer resource manager.
222  * @res_type: The resource type.
223  * @user_key: The user-space id of the resource.
224  * @list: The staging list.
225  * @res_p: If the resource is in an already committed state, points to the
226  * struct vmw_resource on successful return. The pointer will be
227  * non ref-counted.
228  *
229  * This function looks up the struct vmw_cmdbuf_res entry from the manager
230  * hash table and, if it exists, removes it. Depending on its current staging
231  * state it then either removes the entry from the staging list or adds it
232  * to it with a staging state of removal.
233  */
234 int vmw_cmdbuf_res_remove(struct vmw_cmdbuf_res_manager *man,
235 			  enum vmw_cmdbuf_res_type res_type,
236 			  u32 user_key,
237 			  struct list_head *list,
238 			  struct vmw_resource **res_p)
239 {
240 	struct vmw_cmdbuf_res *entry = NULL;
241 	struct vmwgfx_hash_item *hash;
242 	unsigned long key = user_key | (res_type << 24);
243 
244 	hash_for_each_possible_rcu(man->resources, hash, head, key) {
245 		if (hash->key == key) {
246 			entry = drm_hash_entry(hash, struct vmw_cmdbuf_res, hash);
247 			break;
248 		}
249 	}
250 	if (unlikely(!entry))
251 		return -EINVAL;
252 
253 	switch (entry->state) {
254 	case VMW_CMDBUF_RES_ADD:
255 		vmw_cmdbuf_res_free(man, entry);
256 		*res_p = NULL;
257 		break;
258 	case VMW_CMDBUF_RES_COMMITTED:
259 		hash_del_rcu(&entry->hash.head);
260 		list_del(&entry->head);
261 		entry->state = VMW_CMDBUF_RES_DEL;
262 		list_add_tail(&entry->head, list);
263 		*res_p = entry->res;
264 		break;
265 	default:
266 		BUG();
267 		break;
268 	}
269 
270 	return 0;
271 }
272 
273 /**
274  * vmw_cmdbuf_res_man_create - Allocate a command buffer managed resource
275  * manager.
276  *
277  * @dev_priv: Pointer to a struct vmw_private
278  *
279  * Allocates and initializes a command buffer managed resource manager. Returns
280  * an error pointer on failure.
281  */
282 struct vmw_cmdbuf_res_manager *
283 vmw_cmdbuf_res_man_create(struct vmw_private *dev_priv)
284 {
285 	struct vmw_cmdbuf_res_manager *man;
286 
287 	man = kzalloc(sizeof(*man), GFP_KERNEL);
288 	if (!man)
289 		return ERR_PTR(-ENOMEM);
290 
291 	man->dev_priv = dev_priv;
292 	INIT_LIST_HEAD(&man->list);
293 	hash_init(man->resources);
294 	return man;
295 }
296 
297 /**
298  * vmw_cmdbuf_res_man_destroy - Destroy a command buffer managed resource
299  * manager.
300  *
301  * @man: Pointer to the  manager to destroy.
302  *
303  * This function destroys a command buffer managed resource manager and
304  * unreferences / frees all command buffer managed resources and -entries
305  * associated with it.
306  */
307 void vmw_cmdbuf_res_man_destroy(struct vmw_cmdbuf_res_manager *man)
308 {
309 	struct vmw_cmdbuf_res *entry, *next;
310 
311 	list_for_each_entry_safe(entry, next, &man->list, head)
312 		vmw_cmdbuf_res_free(man, entry);
313 
314 	kfree(man);
315 }
316 
317