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786d7257 ML |
1 | /* |
2 | * Header file for reservations for dma-buf and ttm | |
3 | * | |
4 | * Copyright(C) 2011 Linaro Limited. All rights reserved. | |
5 | * Copyright (C) 2012-2013 Canonical Ltd | |
6 | * Copyright (C) 2012 Texas Instruments | |
7 | * | |
8 | * Authors: | |
0ba6b8fb | 9 | * Rob Clark <robdclark@gmail.com> |
786d7257 ML |
10 | * Maarten Lankhorst <maarten.lankhorst@canonical.com> |
11 | * Thomas Hellstrom <thellstrom-at-vmware-dot-com> | |
12 | * | |
13 | * Based on bo.c which bears the following copyright notice, | |
14 | * but is dual licensed: | |
15 | * | |
16 | * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA | |
17 | * All Rights Reserved. | |
18 | * | |
19 | * Permission is hereby granted, free of charge, to any person obtaining a | |
20 | * copy of this software and associated documentation files (the | |
21 | * "Software"), to deal in the Software without restriction, including | |
22 | * without limitation the rights to use, copy, modify, merge, publish, | |
23 | * distribute, sub license, and/or sell copies of the Software, and to | |
24 | * permit persons to whom the Software is furnished to do so, subject to | |
25 | * the following conditions: | |
26 | * | |
27 | * The above copyright notice and this permission notice (including the | |
28 | * next paragraph) shall be included in all copies or substantial portions | |
29 | * of the Software. | |
30 | * | |
31 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
32 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
33 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL | |
34 | * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, | |
35 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR | |
36 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE | |
37 | * USE OR OTHER DEALINGS IN THE SOFTWARE. | |
38 | */ | |
39 | #ifndef _LINUX_RESERVATION_H | |
40 | #define _LINUX_RESERVATION_H | |
41 | ||
1b375dc3 | 42 | #include <linux/ww_mutex.h> |
f54d1867 | 43 | #include <linux/dma-fence.h> |
0ba6b8fb | 44 | #include <linux/slab.h> |
3c3b177a ML |
45 | #include <linux/seqlock.h> |
46 | #include <linux/rcupdate.h> | |
786d7257 ML |
47 | |
48 | extern struct ww_class reservation_ww_class; | |
3c3b177a ML |
49 | extern struct lock_class_key reservation_seqcount_class; |
50 | extern const char reservation_seqcount_string[]; | |
786d7257 | 51 | |
dad6c394 RC |
52 | /** |
53 | * struct reservation_object_list - a list of shared fences | |
54 | * @rcu: for internal use | |
55 | * @shared_count: table of shared fences | |
56 | * @shared_max: for growing shared fence table | |
57 | * @shared: shared fence table | |
58 | */ | |
04a5faa8 | 59 | struct reservation_object_list { |
3c3b177a | 60 | struct rcu_head rcu; |
04a5faa8 | 61 | u32 shared_count, shared_max; |
f54d1867 | 62 | struct dma_fence __rcu *shared[]; |
04a5faa8 ML |
63 | }; |
64 | ||
dad6c394 RC |
65 | /** |
66 | * struct reservation_object - a reservation object manages fences for a buffer | |
67 | * @lock: update side lock | |
68 | * @seq: sequence count for managing RCU read-side synchronization | |
69 | * @fence_excl: the exclusive fence, if there is one currently | |
70 | * @fence: list of current shared fences | |
dad6c394 | 71 | */ |
786d7257 ML |
72 | struct reservation_object { |
73 | struct ww_mutex lock; | |
3c3b177a | 74 | seqcount_t seq; |
0ba6b8fb | 75 | |
f54d1867 | 76 | struct dma_fence __rcu *fence_excl; |
3c3b177a | 77 | struct reservation_object_list __rcu *fence; |
786d7257 ML |
78 | }; |
79 | ||
3c3b177a | 80 | #define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base) |
04a5faa8 ML |
81 | #define reservation_object_assert_held(obj) \ |
82 | lockdep_assert_held(&(obj)->lock.base) | |
83 | ||
dad6c394 RC |
84 | /** |
85 | * reservation_object_init - initialize a reservation object | |
86 | * @obj: the reservation object | |
87 | */ | |
786d7257 ML |
88 | static inline void |
89 | reservation_object_init(struct reservation_object *obj) | |
90 | { | |
91 | ww_mutex_init(&obj->lock, &reservation_ww_class); | |
0ba6b8fb | 92 | |
3c3b177a ML |
93 | __seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class); |
94 | RCU_INIT_POINTER(obj->fence, NULL); | |
95 | RCU_INIT_POINTER(obj->fence_excl, NULL); | |
786d7257 ML |
96 | } |
97 | ||
dad6c394 RC |
98 | /** |
99 | * reservation_object_fini - destroys a reservation object | |
100 | * @obj: the reservation object | |
101 | */ | |
786d7257 ML |
102 | static inline void |
103 | reservation_object_fini(struct reservation_object *obj) | |
104 | { | |
0ba6b8fb | 105 | int i; |
04a5faa8 | 106 | struct reservation_object_list *fobj; |
f54d1867 | 107 | struct dma_fence *excl; |
0ba6b8fb | 108 | |
04a5faa8 ML |
109 | /* |
110 | * This object should be dead and all references must have | |
3c3b177a | 111 | * been released to it, so no need to be protected with rcu. |
04a5faa8 | 112 | */ |
3c3b177a ML |
113 | excl = rcu_dereference_protected(obj->fence_excl, 1); |
114 | if (excl) | |
f54d1867 | 115 | dma_fence_put(excl); |
04a5faa8 | 116 | |
3c3b177a | 117 | fobj = rcu_dereference_protected(obj->fence, 1); |
04a5faa8 ML |
118 | if (fobj) { |
119 | for (i = 0; i < fobj->shared_count; ++i) | |
f54d1867 | 120 | dma_fence_put(rcu_dereference_protected(fobj->shared[i], 1)); |
04a5faa8 ML |
121 | |
122 | kfree(fobj); | |
123 | } | |
0ba6b8fb | 124 | |
786d7257 ML |
125 | ww_mutex_destroy(&obj->lock); |
126 | } | |
127 | ||
dad6c394 RC |
128 | /** |
129 | * reservation_object_get_list - get the reservation object's | |
130 | * shared fence list, with update-side lock held | |
131 | * @obj: the reservation object | |
132 | * | |
133 | * Returns the shared fence list. Does NOT take references to | |
134 | * the fence. The obj->lock must be held. | |
135 | */ | |
04a5faa8 ML |
136 | static inline struct reservation_object_list * |
137 | reservation_object_get_list(struct reservation_object *obj) | |
138 | { | |
3c3b177a ML |
139 | return rcu_dereference_protected(obj->fence, |
140 | reservation_object_held(obj)); | |
04a5faa8 ML |
141 | } |
142 | ||
122020af CW |
143 | /** |
144 | * reservation_object_lock - lock the reservation object | |
145 | * @obj: the reservation object | |
146 | * @ctx: the locking context | |
147 | * | |
148 | * Locks the reservation object for exclusive access and modification. Note, | |
149 | * that the lock is only against other writers, readers will run concurrently | |
150 | * with a writer under RCU. The seqlock is used to notify readers if they | |
151 | * overlap with a writer. | |
152 | * | |
153 | * As the reservation object may be locked by multiple parties in an | |
154 | * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle | |
155 | * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation | |
156 | * object may be locked by itself by passing NULL as @ctx. | |
157 | */ | |
158 | static inline int | |
159 | reservation_object_lock(struct reservation_object *obj, | |
160 | struct ww_acquire_ctx *ctx) | |
161 | { | |
162 | return ww_mutex_lock(&obj->lock, ctx); | |
163 | } | |
164 | ||
5d276a1a CK |
165 | /** |
166 | * reservation_object_lock_interruptible - lock the reservation object | |
167 | * @obj: the reservation object | |
168 | * @ctx: the locking context | |
169 | * | |
170 | * Locks the reservation object interruptible for exclusive access and | |
171 | * modification. Note, that the lock is only against other writers, readers | |
172 | * will run concurrently with a writer under RCU. The seqlock is used to | |
173 | * notify readers if they overlap with a writer. | |
174 | * | |
175 | * As the reservation object may be locked by multiple parties in an | |
176 | * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle | |
177 | * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation | |
178 | * object may be locked by itself by passing NULL as @ctx. | |
179 | */ | |
180 | static inline int | |
181 | reservation_object_lock_interruptible(struct reservation_object *obj, | |
182 | struct ww_acquire_ctx *ctx) | |
183 | { | |
184 | return ww_mutex_lock_interruptible(&obj->lock, ctx); | |
185 | } | |
186 | ||
187 | ||
2955b73d CW |
188 | /** |
189 | * reservation_object_trylock - trylock the reservation object | |
190 | * @obj: the reservation object | |
191 | * | |
192 | * Tries to lock the reservation object for exclusive access and modification. | |
193 | * Note, that the lock is only against other writers, readers will run | |
194 | * concurrently with a writer under RCU. The seqlock is used to notify readers | |
195 | * if they overlap with a writer. | |
196 | * | |
197 | * Also note that since no context is provided, no deadlock protection is | |
198 | * possible. | |
199 | * | |
200 | * Returns true if the lock was acquired, false otherwise. | |
201 | */ | |
202 | static inline bool __must_check | |
203 | reservation_object_trylock(struct reservation_object *obj) | |
204 | { | |
205 | return ww_mutex_trylock(&obj->lock); | |
206 | } | |
207 | ||
122020af CW |
208 | /** |
209 | * reservation_object_unlock - unlock the reservation object | |
210 | * @obj: the reservation object | |
211 | * | |
212 | * Unlocks the reservation object following exclusive access. | |
213 | */ | |
214 | static inline void | |
215 | reservation_object_unlock(struct reservation_object *obj) | |
216 | { | |
99fe21a7 CK |
217 | #ifdef CONFIG_DEBUG_MUTEXES |
218 | /* Test shared fence slot reservation */ | |
219 | if (obj->fence) | |
220 | obj->fence->shared_max = obj->fence->shared_count; | |
221 | #endif | |
122020af CW |
222 | ww_mutex_unlock(&obj->lock); |
223 | } | |
224 | ||
dad6c394 RC |
225 | /** |
226 | * reservation_object_get_excl - get the reservation object's | |
227 | * exclusive fence, with update-side lock held | |
228 | * @obj: the reservation object | |
229 | * | |
230 | * Returns the exclusive fence (if any). Does NOT take a | |
372c9329 LS |
231 | * reference. Writers must hold obj->lock, readers may only |
232 | * hold a RCU read side lock. | |
dad6c394 RC |
233 | * |
234 | * RETURNS | |
235 | * The exclusive fence or NULL | |
236 | */ | |
f54d1867 | 237 | static inline struct dma_fence * |
04a5faa8 ML |
238 | reservation_object_get_excl(struct reservation_object *obj) |
239 | { | |
3c3b177a ML |
240 | return rcu_dereference_protected(obj->fence_excl, |
241 | reservation_object_held(obj)); | |
04a5faa8 ML |
242 | } |
243 | ||
dad6c394 RC |
244 | /** |
245 | * reservation_object_get_excl_rcu - get the reservation object's | |
246 | * exclusive fence, without lock held. | |
247 | * @obj: the reservation object | |
248 | * | |
249 | * If there is an exclusive fence, this atomically increments it's | |
250 | * reference count and returns it. | |
251 | * | |
252 | * RETURNS | |
253 | * The exclusive fence or NULL if none | |
254 | */ | |
f54d1867 | 255 | static inline struct dma_fence * |
824815c4 RC |
256 | reservation_object_get_excl_rcu(struct reservation_object *obj) |
257 | { | |
f54d1867 | 258 | struct dma_fence *fence; |
6bfec6d9 CW |
259 | |
260 | if (!rcu_access_pointer(obj->fence_excl)) | |
261 | return NULL; | |
262 | ||
824815c4 | 263 | rcu_read_lock(); |
6bfec6d9 | 264 | fence = dma_fence_get_rcu_safe(&obj->fence_excl); |
824815c4 | 265 | rcu_read_unlock(); |
6bfec6d9 | 266 | |
824815c4 RC |
267 | return fence; |
268 | } | |
269 | ||
ca05359f CK |
270 | int reservation_object_reserve_shared(struct reservation_object *obj, |
271 | unsigned int num_fences); | |
04a5faa8 | 272 | void reservation_object_add_shared_fence(struct reservation_object *obj, |
f54d1867 | 273 | struct dma_fence *fence); |
04a5faa8 ML |
274 | |
275 | void reservation_object_add_excl_fence(struct reservation_object *obj, | |
f54d1867 | 276 | struct dma_fence *fence); |
04a5faa8 | 277 | |
3c3b177a | 278 | int reservation_object_get_fences_rcu(struct reservation_object *obj, |
f54d1867 | 279 | struct dma_fence **pfence_excl, |
3c3b177a | 280 | unsigned *pshared_count, |
f54d1867 | 281 | struct dma_fence ***pshared); |
3c3b177a | 282 | |
7faf952a CK |
283 | int reservation_object_copy_fences(struct reservation_object *dst, |
284 | struct reservation_object *src); | |
285 | ||
3c3b177a ML |
286 | long reservation_object_wait_timeout_rcu(struct reservation_object *obj, |
287 | bool wait_all, bool intr, | |
288 | unsigned long timeout); | |
289 | ||
290 | bool reservation_object_test_signaled_rcu(struct reservation_object *obj, | |
291 | bool test_all); | |
292 | ||
786d7257 | 293 | #endif /* _LINUX_RESERVATION_H */ |