1 /* 1 /*
2 * Header file for reservations for dma-buf an 2 * Header file for reservations for dma-buf and ttm
3 * 3 *
4 * Copyright(C) 2011 Linaro Limited. All right 4 * Copyright(C) 2011 Linaro Limited. All rights reserved.
5 * Copyright (C) 2012-2013 Canonical Ltd 5 * Copyright (C) 2012-2013 Canonical Ltd
6 * Copyright (C) 2012 Texas Instruments 6 * Copyright (C) 2012 Texas Instruments
7 * 7 *
8 * Authors: 8 * Authors:
9 * Rob Clark <robdclark@gmail.com> 9 * Rob Clark <robdclark@gmail.com>
10 * Maarten Lankhorst <maarten.lankhorst@canoni 10 * Maarten Lankhorst <maarten.lankhorst@canonical.com>
11 * Thomas Hellstrom <thellstrom-at-vmware-dot- 11 * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
12 * 12 *
13 * Based on bo.c which bears the following cop 13 * Based on bo.c which bears the following copyright notice,
14 * but is dual licensed: 14 * but is dual licensed:
15 * 15 *
16 * Copyright (c) 2006-2009 VMware, Inc., Palo 16 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
17 * All Rights Reserved. 17 * All Rights Reserved.
18 * 18 *
19 * Permission is hereby granted, free of charg 19 * Permission is hereby granted, free of charge, to any person obtaining a
20 * copy of this software and associated docume 20 * copy of this software and associated documentation files (the
21 * "Software"), to deal in the Software withou 21 * "Software"), to deal in the Software without restriction, including
22 * without limitation the rights to use, copy, 22 * without limitation the rights to use, copy, modify, merge, publish,
23 * distribute, sub license, and/or sell copies 23 * distribute, sub license, and/or sell copies of the Software, and to
24 * permit persons to whom the Software is furn 24 * permit persons to whom the Software is furnished to do so, subject to
25 * the following conditions: 25 * the following conditions:
26 * 26 *
27 * The above copyright notice and this permiss 27 * The above copyright notice and this permission notice (including the
28 * next paragraph) shall be included in all co 28 * next paragraph) shall be included in all copies or substantial portions
29 * of the Software. 29 * of the Software.
30 * 30 *
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT W 31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
32 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE W 32 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
33 * FITNESS FOR A PARTICULAR PURPOSE AND NON-IN 33 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
34 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS S 34 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
35 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN A 35 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
36 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNE 36 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
37 * USE OR OTHER DEALINGS IN THE SOFTWARE. 37 * USE OR OTHER DEALINGS IN THE SOFTWARE.
38 */ 38 */
39 #ifndef _LINUX_RESERVATION_H 39 #ifndef _LINUX_RESERVATION_H
40 #define _LINUX_RESERVATION_H 40 #define _LINUX_RESERVATION_H
41 41
42 #include <linux/ww_mutex.h> 42 #include <linux/ww_mutex.h>
43 #include <linux/dma-fence.h> 43 #include <linux/dma-fence.h>
44 #include <linux/slab.h> 44 #include <linux/slab.h>
45 #include <linux/seqlock.h> 45 #include <linux/seqlock.h>
46 #include <linux/rcupdate.h> 46 #include <linux/rcupdate.h>
47 47
48 extern struct ww_class reservation_ww_class; 48 extern struct ww_class reservation_ww_class;
49 49
50 struct dma_resv_list; <<
51 <<
52 /** 50 /**
53 * enum dma_resv_usage - how the fences from a !! 51 * struct dma_resv_list - a list of shared fences
54 * !! 52 * @rcu: for internal use
55 * This enum describes the different use cases !! 53 * @shared_count: table of shared fences
56 * controls which fences are returned when que !! 54 * @shared_max: for growing shared fence table
57 * !! 55 * @shared: shared fence table
58 * An important fact is that there is the orde !! 56 */
59 * when the dma_resv object is asked for fence !! 57 struct dma_resv_list {
60 * for the lower use case are returned as well !! 58 struct rcu_head rcu;
61 * !! 59 u32 shared_count, shared_max;
62 * For example when asking for WRITE fences th !! 60 struct dma_fence __rcu *shared[];
63 * as well. Similar when asked for READ fences <<
64 * fences are returned as well. <<
65 * <<
66 * Already used fences can be promoted in the <<
67 * DMA_RESV_USAGE_BOOKKEEP could become DMA_RE <<
68 * with this usage. But fences can never be de <<
69 * with DMA_RESV_USAGE_WRITE could become DMA_ <<
70 */ <<
71 enum dma_resv_usage { <<
72 /** <<
73 * @DMA_RESV_USAGE_KERNEL: For in kern <<
74 * <<
75 * This should only be used for things <<
76 * with a DMA hardware engine for the <<
77 * management. <<
78 * <<
79 * Drivers *always* must wait for thos <<
80 * resource protected by the dma_resv <<
81 * that is when the resource is known <<
82 * pinning it previously. <<
83 */ <<
84 DMA_RESV_USAGE_KERNEL, <<
85 <<
86 /** <<
87 * @DMA_RESV_USAGE_WRITE: Implicit wri <<
88 * <<
89 * This should only be used for usersp <<
90 * an implicit write dependency. <<
91 */ <<
92 DMA_RESV_USAGE_WRITE, <<
93 <<
94 /** <<
95 * @DMA_RESV_USAGE_READ: Implicit read <<
96 * <<
97 * This should only be used for usersp <<
98 * an implicit read dependency. <<
99 */ <<
100 DMA_RESV_USAGE_READ, <<
101 <<
102 /** <<
103 * @DMA_RESV_USAGE_BOOKKEEP: No implic <<
104 * <<
105 * This should be used by submissions <<
106 * any implicit synchronization. <<
107 * <<
108 * The most common case are preemption <<
109 * flushes as well as explicit synced <<
110 * <<
111 * Explicit synced user user submissio <<
112 * DMA_RESV_USAGE_READ or DMA_RESV_USA <<
113 * dma_buf_import_sync_file() when imp <<
114 * become necessary after initial addi <<
115 */ <<
116 DMA_RESV_USAGE_BOOKKEEP <<
117 }; 61 };
118 62
119 /** 63 /**
120 * dma_resv_usage_rw - helper for implicit syn <<
121 * @write: true if we create a new implicit sy <<
122 * <<
123 * This returns the implicit synchronization u <<
124 * see enum dma_resv_usage and &dma_buf.resv. <<
125 */ <<
126 static inline enum dma_resv_usage dma_resv_usa <<
127 { <<
128 /* This looks confusing at first sight <<
129 * <<
130 * The rational is that new write oper <<
131 * existing read and write operations <<
132 * But a new read operation only needs <<
133 * operations to finish. <<
134 */ <<
135 return write ? DMA_RESV_USAGE_READ : D <<
136 } <<
137 <<
138 /** <<
139 * struct dma_resv - a reservation object mana 64 * struct dma_resv - a reservation object manages fences for a buffer
140 * !! 65 * @lock: update side lock
141 * This is a container for dma_fence objects w !! 66 * @seq: sequence count for managing RCU read-side synchronization
142 * cases. !! 67 * @fence_excl: the exclusive fence, if there is one currently
143 * !! 68 * @fence: list of current shared fences
144 * One use is to synchronize cross-driver acce <<
145 * dynamic buffer management or just to handle <<
146 * different users of the buffer in userspace. <<
147 * in-depth discussion. <<
148 * <<
149 * The other major use is to manage access and <<
150 * buffer based memory manager. struct ttm_buf <<
151 * example here, since this is where reservati <<
152 * use in drivers is spreading and some driver <<
153 * drm_gem_object with the same scheme. <<
154 */ 69 */
155 struct dma_resv { 70 struct dma_resv {
156 /** <<
157 * @lock: <<
158 * <<
159 * Update side lock. Don't use directl <<
160 * functions like dma_resv_lock() and <<
161 * <<
162 * Drivers which use the reservation o <<
163 * also use this lock to protect buffe <<
164 * allocation policies or throughout c <<
165 */ <<
166 struct ww_mutex lock; 71 struct ww_mutex lock;
>> 72 seqcount_ww_mutex_t seq;
167 73
168 /** !! 74 struct dma_fence __rcu *fence_excl;
169 * @fences: !! 75 struct dma_resv_list __rcu *fence;
170 * <<
171 * Array of fences which where added t <<
172 * <<
173 * A new fence is added by calling dma <<
174 * often needs to be done past the poi <<
175 * submission it cannot fail, and ther <<
176 * reserved by calling dma_resv_reserv <<
177 */ <<
178 struct dma_resv_list __rcu *fences; <<
179 }; <<
180 <<
181 /** <<
182 * struct dma_resv_iter - current position int <<
183 * <<
184 * Don't touch this directly in the driver, us <<
185 * <<
186 * IMPORTANT <<
187 * <<
188 * When using the lockless iterators like dma_ <<
189 * dma_resv_for_each_fence_unlocked() beware t <<
190 * Code which accumulates statistics or simila <<
191 * dma_resv_iter_is_restarted(). <<
192 */ <<
193 struct dma_resv_iter { <<
194 /** @obj: The dma_resv object we itera <<
195 struct dma_resv *obj; <<
196 <<
197 /** @usage: Return fences with this us <<
198 enum dma_resv_usage usage; <<
199 <<
200 /** @fence: the currently handled fenc <<
201 struct dma_fence *fence; <<
202 <<
203 /** @fence_usage: the usage of the cur <<
204 enum dma_resv_usage fence_usage; <<
205 <<
206 /** @index: index into the shared fenc <<
207 unsigned int index; <<
208 <<
209 /** @fences: the shared fences; privat <<
210 struct dma_resv_list *fences; <<
211 <<
212 /** @num_fences: number of fences */ <<
213 unsigned int num_fences; <<
214 <<
215 /** @is_restarted: true if this is the <<
216 bool is_restarted; <<
217 }; 76 };
218 77
219 struct dma_fence *dma_resv_iter_first_unlocked !! 78 #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
220 struct dma_fence *dma_resv_iter_next_unlocked( !! 79 #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
221 struct dma_fence *dma_resv_iter_first(struct d <<
222 struct dma_fence *dma_resv_iter_next(struct dm <<
223 <<
224 /** <<
225 * dma_resv_iter_begin - initialize a dma_resv <<
226 * @cursor: The dma_resv_iter object to initia <<
227 * @obj: The dma_resv object which we want to <<
228 * @usage: controls which fences to include, s <<
229 */ <<
230 static inline void dma_resv_iter_begin(struct <<
231 struct <<
232 enum dm <<
233 { <<
234 cursor->obj = obj; <<
235 cursor->usage = usage; <<
236 cursor->fence = NULL; <<
237 } <<
238 <<
239 /** <<
240 * dma_resv_iter_end - cleanup a dma_resv_iter <<
241 * @cursor: the dma_resv_iter object which sho <<
242 * <<
243 * Make sure that the reference to the fence i <<
244 * dropped. <<
245 */ <<
246 static inline void dma_resv_iter_end(struct dm <<
247 { <<
248 dma_fence_put(cursor->fence); <<
249 } <<
250 <<
251 /** <<
252 * dma_resv_iter_usage - Return the usage of t <<
253 * @cursor: the cursor of the current position <<
254 * <<
255 * Returns the usage of the currently processe <<
256 */ <<
257 static inline enum dma_resv_usage <<
258 dma_resv_iter_usage(struct dma_resv_iter *curs <<
259 { <<
260 return cursor->fence_usage; <<
261 } <<
262 80
263 /** 81 /**
264 * dma_resv_iter_is_restarted - test if this i !! 82 * dma_resv_get_list - get the reservation object's
265 * @cursor: the cursor with the current positi !! 83 * shared fence list, with update-side lock held
>> 84 * @obj: the reservation object
266 * 85 *
267 * Return true if this is the first fence in a !! 86 * Returns the shared fence list. Does NOT take references to
>> 87 * the fence. The obj->lock must be held.
268 */ 88 */
269 static inline bool dma_resv_iter_is_restarted( !! 89 static inline struct dma_resv_list *dma_resv_get_list(struct dma_resv *obj)
270 { 90 {
271 return cursor->is_restarted; !! 91 return rcu_dereference_protected(obj->fence,
>> 92 dma_resv_held(obj));
272 } 93 }
273 94
274 /** 95 /**
275 * dma_resv_for_each_fence_unlocked - unlocked <<
276 * @cursor: a struct dma_resv_iter pointer <<
277 * @fence: the current fence <<
278 * <<
279 * Iterate over the fences in a struct dma_res <<
280 * &dma_resv.lock and using RCU instead. The c <<
281 * with dma_resv_iter_begin() and cleaned up w <<
282 * the iterator a reference to the dma_fence i <<
283 * <<
284 * Beware that the iterator can be restarted w <<
285 * @cursor is modified. Code which accumulates <<
286 * check for this with dma_resv_iter_is_restar <<
287 * lock iterator dma_resv_for_each_fence() whe <<
288 */ <<
289 #define dma_resv_for_each_fence_unlocked(curso <<
290 for (fence = dma_resv_iter_first_unloc <<
291 fence; fence = dma_resv_iter_next <<
292 <<
293 /** <<
294 * dma_resv_for_each_fence - fence iterator <<
295 * @cursor: a struct dma_resv_iter pointer <<
296 * @obj: a dma_resv object pointer <<
297 * @usage: controls which fences to return <<
298 * @fence: the current fence <<
299 * <<
300 * Iterate over the fences in a struct dma_res <<
301 * &dma_resv.lock. @all_fences controls if the <<
302 * well. The cursor initialisation is part of <<
303 * valid as long as the lock is held and so no <<
304 * taken. <<
305 */ <<
306 #define dma_resv_for_each_fence(cursor, obj, u <<
307 for (dma_resv_iter_begin(cursor, obj, <<
308 fence = dma_resv_iter_first(curso <<
309 fence = dma_resv_iter_next(cursor <<
310 <<
311 #define dma_resv_held(obj) lockdep_is_held(&(o <<
312 #define dma_resv_assert_held(obj) lockdep_asse <<
313 <<
314 #ifdef CONFIG_DEBUG_MUTEXES <<
315 void dma_resv_reset_max_fences(struct dma_resv <<
316 #else <<
317 static inline void dma_resv_reset_max_fences(s <<
318 #endif <<
319 <<
320 /** <<
321 * dma_resv_lock - lock the reservation object 96 * dma_resv_lock - lock the reservation object
322 * @obj: the reservation object 97 * @obj: the reservation object
323 * @ctx: the locking context 98 * @ctx: the locking context
324 * 99 *
325 * Locks the reservation object for exclusive 100 * Locks the reservation object for exclusive access and modification. Note,
326 * that the lock is only against other writers 101 * that the lock is only against other writers, readers will run concurrently
327 * with a writer under RCU. The seqlock is use 102 * with a writer under RCU. The seqlock is used to notify readers if they
328 * overlap with a writer. 103 * overlap with a writer.
329 * 104 *
330 * As the reservation object may be locked by 105 * As the reservation object may be locked by multiple parties in an
331 * undefined order, a #ww_acquire_ctx is passe 106 * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle
332 * is detected. See ww_mutex_lock() and ww_acq 107 * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation
333 * object may be locked by itself by passing N 108 * object may be locked by itself by passing NULL as @ctx.
334 * <<
335 * When a die situation is indicated by return <<
336 * @ctx must be unlocked and then dma_resv_loc <<
337 * <<
338 * Unlocked by calling dma_resv_unlock(). <<
339 * <<
340 * See also dma_resv_lock_interruptible() for <<
341 */ 109 */
342 static inline int dma_resv_lock(struct dma_res 110 static inline int dma_resv_lock(struct dma_resv *obj,
343 struct ww_acqu 111 struct ww_acquire_ctx *ctx)
344 { 112 {
345 return ww_mutex_lock(&obj->lock, ctx); 113 return ww_mutex_lock(&obj->lock, ctx);
346 } 114 }
347 115
348 /** 116 /**
349 * dma_resv_lock_interruptible - lock the rese 117 * dma_resv_lock_interruptible - lock the reservation object
350 * @obj: the reservation object 118 * @obj: the reservation object
351 * @ctx: the locking context 119 * @ctx: the locking context
352 * 120 *
353 * Locks the reservation object interruptible 121 * Locks the reservation object interruptible for exclusive access and
354 * modification. Note, that the lock is only a 122 * modification. Note, that the lock is only against other writers, readers
355 * will run concurrently with a writer under R 123 * will run concurrently with a writer under RCU. The seqlock is used to
356 * notify readers if they overlap with a write 124 * notify readers if they overlap with a writer.
357 * 125 *
358 * As the reservation object may be locked by 126 * As the reservation object may be locked by multiple parties in an
359 * undefined order, a #ww_acquire_ctx is passe 127 * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle
360 * is detected. See ww_mutex_lock() and ww_acq 128 * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation
361 * object may be locked by itself by passing N 129 * object may be locked by itself by passing NULL as @ctx.
362 * <<
363 * When a die situation is indicated by return <<
364 * @ctx must be unlocked and then dma_resv_loc <<
365 * @obj. <<
366 * <<
367 * Unlocked by calling dma_resv_unlock(). <<
368 */ 130 */
369 static inline int dma_resv_lock_interruptible( 131 static inline int dma_resv_lock_interruptible(struct dma_resv *obj,
370 132 struct ww_acquire_ctx *ctx)
371 { 133 {
372 return ww_mutex_lock_interruptible(&ob 134 return ww_mutex_lock_interruptible(&obj->lock, ctx);
373 } 135 }
374 136
375 /** 137 /**
376 * dma_resv_lock_slow - slowpath lock the rese 138 * dma_resv_lock_slow - slowpath lock the reservation object
377 * @obj: the reservation object 139 * @obj: the reservation object
378 * @ctx: the locking context 140 * @ctx: the locking context
379 * 141 *
380 * Acquires the reservation object after a die 142 * Acquires the reservation object after a die case. This function
381 * will sleep until the lock becomes available 143 * will sleep until the lock becomes available. See dma_resv_lock() as
382 * well. 144 * well.
383 * <<
384 * See also dma_resv_lock_slow_interruptible() <<
385 */ 145 */
386 static inline void dma_resv_lock_slow(struct d 146 static inline void dma_resv_lock_slow(struct dma_resv *obj,
387 struct w 147 struct ww_acquire_ctx *ctx)
388 { 148 {
389 ww_mutex_lock_slow(&obj->lock, ctx); 149 ww_mutex_lock_slow(&obj->lock, ctx);
390 } 150 }
391 151
392 /** 152 /**
393 * dma_resv_lock_slow_interruptible - slowpath 153 * dma_resv_lock_slow_interruptible - slowpath lock the reservation
394 * object, interruptible 154 * object, interruptible
395 * @obj: the reservation object 155 * @obj: the reservation object
396 * @ctx: the locking context 156 * @ctx: the locking context
397 * 157 *
398 * Acquires the reservation object interruptib 158 * Acquires the reservation object interruptible after a die case. This function
399 * will sleep until the lock becomes available 159 * will sleep until the lock becomes available. See
400 * dma_resv_lock_interruptible() as well. 160 * dma_resv_lock_interruptible() as well.
401 */ 161 */
402 static inline int dma_resv_lock_slow_interrupt 162 static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj,
403 163 struct ww_acquire_ctx *ctx)
404 { 164 {
405 return ww_mutex_lock_slow_interruptibl 165 return ww_mutex_lock_slow_interruptible(&obj->lock, ctx);
406 } 166 }
407 167
408 /** 168 /**
409 * dma_resv_trylock - trylock the reservation 169 * dma_resv_trylock - trylock the reservation object
410 * @obj: the reservation object 170 * @obj: the reservation object
411 * 171 *
412 * Tries to lock the reservation object for ex 172 * Tries to lock the reservation object for exclusive access and modification.
413 * Note, that the lock is only against other w 173 * Note, that the lock is only against other writers, readers will run
414 * concurrently with a writer under RCU. The s 174 * concurrently with a writer under RCU. The seqlock is used to notify readers
415 * if they overlap with a writer. 175 * if they overlap with a writer.
416 * 176 *
417 * Also note that since no context is provided 177 * Also note that since no context is provided, no deadlock protection is
418 * possible, which is also not needed for a tr !! 178 * possible.
419 * 179 *
420 * Returns true if the lock was acquired, fals 180 * Returns true if the lock was acquired, false otherwise.
421 */ 181 */
422 static inline bool __must_check dma_resv_trylo 182 static inline bool __must_check dma_resv_trylock(struct dma_resv *obj)
423 { 183 {
424 return ww_mutex_trylock(&obj->lock, NU !! 184 return ww_mutex_trylock(&obj->lock);
425 } 185 }
426 186
427 /** 187 /**
428 * dma_resv_is_locked - is the reservation obj 188 * dma_resv_is_locked - is the reservation object locked
429 * @obj: the reservation object 189 * @obj: the reservation object
430 * 190 *
431 * Returns true if the mutex is locked, false 191 * Returns true if the mutex is locked, false if unlocked.
432 */ 192 */
433 static inline bool dma_resv_is_locked(struct d 193 static inline bool dma_resv_is_locked(struct dma_resv *obj)
434 { 194 {
435 return ww_mutex_is_locked(&obj->lock); 195 return ww_mutex_is_locked(&obj->lock);
436 } 196 }
437 197
438 /** 198 /**
439 * dma_resv_locking_ctx - returns the context 199 * dma_resv_locking_ctx - returns the context used to lock the object
440 * @obj: the reservation object 200 * @obj: the reservation object
441 * 201 *
442 * Returns the context used to lock a reservat 202 * Returns the context used to lock a reservation object or NULL if no context
443 * was used or the object is not locked at all 203 * was used or the object is not locked at all.
444 * <<
445 * WARNING: This interface is pretty horrible, <<
446 * doesn't pass the struct ww_acquire_ctx arou <<
447 * Everyone else just uses it to check whether <<
448 * not. <<
449 */ 204 */
450 static inline struct ww_acquire_ctx *dma_resv_ 205 static inline struct ww_acquire_ctx *dma_resv_locking_ctx(struct dma_resv *obj)
451 { 206 {
452 return READ_ONCE(obj->lock.ctx); 207 return READ_ONCE(obj->lock.ctx);
453 } 208 }
454 209
455 /** 210 /**
456 * dma_resv_unlock - unlock the reservation ob 211 * dma_resv_unlock - unlock the reservation object
457 * @obj: the reservation object 212 * @obj: the reservation object
458 * 213 *
459 * Unlocks the reservation object following ex 214 * Unlocks the reservation object following exclusive access.
460 */ 215 */
461 static inline void dma_resv_unlock(struct dma_ 216 static inline void dma_resv_unlock(struct dma_resv *obj)
462 { 217 {
463 dma_resv_reset_max_fences(obj); !! 218 #ifdef CONFIG_DEBUG_MUTEXES
>> 219 /* Test shared fence slot reservation */
>> 220 if (rcu_access_pointer(obj->fence)) {
>> 221 struct dma_resv_list *fence = dma_resv_get_list(obj);
>> 222
>> 223 fence->shared_max = fence->shared_count;
>> 224 }
>> 225 #endif
464 ww_mutex_unlock(&obj->lock); 226 ww_mutex_unlock(&obj->lock);
465 } 227 }
466 228
>> 229 /**
>> 230 * dma_resv_get_excl - get the reservation object's
>> 231 * exclusive fence, with update-side lock held
>> 232 * @obj: the reservation object
>> 233 *
>> 234 * Returns the exclusive fence (if any). Does NOT take a
>> 235 * reference. Writers must hold obj->lock, readers may only
>> 236 * hold a RCU read side lock.
>> 237 *
>> 238 * RETURNS
>> 239 * The exclusive fence or NULL
>> 240 */
>> 241 static inline struct dma_fence *
>> 242 dma_resv_get_excl(struct dma_resv *obj)
>> 243 {
>> 244 return rcu_dereference_protected(obj->fence_excl,
>> 245 dma_resv_held(obj));
>> 246 }
>> 247
>> 248 /**
>> 249 * dma_resv_get_excl_rcu - get the reservation object's
>> 250 * exclusive fence, without lock held.
>> 251 * @obj: the reservation object
>> 252 *
>> 253 * If there is an exclusive fence, this atomically increments it's
>> 254 * reference count and returns it.
>> 255 *
>> 256 * RETURNS
>> 257 * The exclusive fence or NULL if none
>> 258 */
>> 259 static inline struct dma_fence *
>> 260 dma_resv_get_excl_rcu(struct dma_resv *obj)
>> 261 {
>> 262 struct dma_fence *fence;
>> 263
>> 264 if (!rcu_access_pointer(obj->fence_excl))
>> 265 return NULL;
>> 266
>> 267 rcu_read_lock();
>> 268 fence = dma_fence_get_rcu_safe(&obj->fence_excl);
>> 269 rcu_read_unlock();
>> 270
>> 271 return fence;
>> 272 }
>> 273
467 void dma_resv_init(struct dma_resv *obj); 274 void dma_resv_init(struct dma_resv *obj);
468 void dma_resv_fini(struct dma_resv *obj); 275 void dma_resv_fini(struct dma_resv *obj);
469 int dma_resv_reserve_fences(struct dma_resv *o !! 276 int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences);
470 void dma_resv_add_fence(struct dma_resv *obj, !! 277 void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence);
471 enum dma_resv_usage us !! 278
472 void dma_resv_replace_fences(struct dma_resv * !! 279 void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence);
473 struct dma_fence !! 280
474 enum dma_resv_usa !! 281 int dma_resv_get_fences_rcu(struct dma_resv *obj,
475 int dma_resv_get_fences(struct dma_resv *obj, !! 282 struct dma_fence **pfence_excl,
476 unsigned int *num_fenc !! 283 unsigned *pshared_count,
477 int dma_resv_get_singleton(struct dma_resv *ob !! 284 struct dma_fence ***pshared);
478 struct dma_fence ** !! 285
479 int dma_resv_copy_fences(struct dma_resv *dst, 286 int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
480 long dma_resv_wait_timeout(struct dma_resv *ob !! 287
481 bool intr, unsigned !! 288 long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr,
482 void dma_resv_set_deadline(struct dma_resv *ob !! 289 unsigned long timeout);
483 ktime_t deadline); !! 290
484 bool dma_resv_test_signaled(struct dma_resv *o !! 291 bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all);
485 void dma_resv_describe(struct dma_resv *obj, s <<
486 292
487 #endif /* _LINUX_RESERVATION_H */ 293 #endif /* _LINUX_RESERVATION_H */
488 294
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