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35#include <linux/reservation.h>
36#include <linux/export.h>
37
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46
47
48
49DEFINE_WW_CLASS(reservation_ww_class);
50EXPORT_SYMBOL(reservation_ww_class);
51
52struct lock_class_key reservation_seqcount_class;
53EXPORT_SYMBOL(reservation_seqcount_class);
54
55const char reservation_seqcount_string[] = "reservation_seqcount";
56EXPORT_SYMBOL(reservation_seqcount_string);
57
58
59
60
61
62
63
64
65
66
67
68
69int reservation_object_reserve_shared(struct reservation_object *obj)
70{
71 struct reservation_object_list *fobj, *old;
72 u32 max;
73
74 old = reservation_object_get_list(obj);
75
76 if (old && old->shared_max) {
77 if (old->shared_count < old->shared_max) {
78
79 kfree(obj->staged);
80 obj->staged = NULL;
81 return 0;
82 } else
83 max = old->shared_max * 2;
84 } else
85 max = 4;
86
87
88
89
90
91 fobj = krealloc(obj->staged, offsetof(typeof(*fobj), shared[max]),
92 GFP_KERNEL);
93 if (!fobj)
94 return -ENOMEM;
95
96 obj->staged = fobj;
97 fobj->shared_max = max;
98 return 0;
99}
100EXPORT_SYMBOL(reservation_object_reserve_shared);
101
102static void
103reservation_object_add_shared_inplace(struct reservation_object *obj,
104 struct reservation_object_list *fobj,
105 struct fence *fence)
106{
107 u32 i;
108
109 fence_get(fence);
110
111 preempt_disable();
112 write_seqcount_begin(&obj->seq);
113
114 for (i = 0; i < fobj->shared_count; ++i) {
115 struct fence *old_fence;
116
117 old_fence = rcu_dereference_protected(fobj->shared[i],
118 reservation_object_held(obj));
119
120 if (old_fence->context == fence->context) {
121
122 RCU_INIT_POINTER(fobj->shared[i], fence);
123 write_seqcount_end(&obj->seq);
124 preempt_enable();
125
126 fence_put(old_fence);
127 return;
128 }
129 }
130
131
132
133
134
135 RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
136 fobj->shared_count++;
137
138 write_seqcount_end(&obj->seq);
139 preempt_enable();
140}
141
142static void
143reservation_object_add_shared_replace(struct reservation_object *obj,
144 struct reservation_object_list *old,
145 struct reservation_object_list *fobj,
146 struct fence *fence)
147{
148 unsigned i;
149 struct fence *old_fence = NULL;
150
151 fence_get(fence);
152
153 if (!old) {
154 RCU_INIT_POINTER(fobj->shared[0], fence);
155 fobj->shared_count = 1;
156 goto done;
157 }
158
159
160
161
162
163
164
165 fobj->shared_count = old->shared_count;
166
167 for (i = 0; i < old->shared_count; ++i) {
168 struct fence *check;
169
170 check = rcu_dereference_protected(old->shared[i],
171 reservation_object_held(obj));
172
173 if (!old_fence && check->context == fence->context) {
174 old_fence = check;
175 RCU_INIT_POINTER(fobj->shared[i], fence);
176 } else
177 RCU_INIT_POINTER(fobj->shared[i], check);
178 }
179 if (!old_fence) {
180 RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
181 fobj->shared_count++;
182 }
183
184done:
185 preempt_disable();
186 write_seqcount_begin(&obj->seq);
187
188
189
190
191 RCU_INIT_POINTER(obj->fence, fobj);
192 write_seqcount_end(&obj->seq);
193 preempt_enable();
194
195 if (old)
196 kfree_rcu(old, rcu);
197
198 if (old_fence)
199 fence_put(old_fence);
200}
201
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208
209
210void reservation_object_add_shared_fence(struct reservation_object *obj,
211 struct fence *fence)
212{
213 struct reservation_object_list *old, *fobj = obj->staged;
214
215 old = reservation_object_get_list(obj);
216 obj->staged = NULL;
217
218 if (!fobj) {
219 BUG_ON(old->shared_count >= old->shared_max);
220 reservation_object_add_shared_inplace(obj, old, fence);
221 } else
222 reservation_object_add_shared_replace(obj, old, fobj, fence);
223}
224EXPORT_SYMBOL(reservation_object_add_shared_fence);
225
226
227
228
229
230
231
232
233void reservation_object_add_excl_fence(struct reservation_object *obj,
234 struct fence *fence)
235{
236 struct fence *old_fence = reservation_object_get_excl(obj);
237 struct reservation_object_list *old;
238 u32 i = 0;
239
240 old = reservation_object_get_list(obj);
241 if (old)
242 i = old->shared_count;
243
244 if (fence)
245 fence_get(fence);
246
247 preempt_disable();
248 write_seqcount_begin(&obj->seq);
249
250 RCU_INIT_POINTER(obj->fence_excl, fence);
251 if (old)
252 old->shared_count = 0;
253 write_seqcount_end(&obj->seq);
254 preempt_enable();
255
256
257 while (i--)
258 fence_put(rcu_dereference_protected(old->shared[i],
259 reservation_object_held(obj)));
260
261 if (old_fence)
262 fence_put(old_fence);
263}
264EXPORT_SYMBOL(reservation_object_add_excl_fence);
265
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276
277
278int reservation_object_get_fences_rcu(struct reservation_object *obj,
279 struct fence **pfence_excl,
280 unsigned *pshared_count,
281 struct fence ***pshared)
282{
283 unsigned shared_count = 0;
284 unsigned retry = 1;
285 struct fence **shared = NULL, *fence_excl = NULL;
286 int ret = 0;
287
288 while (retry) {
289 struct reservation_object_list *fobj;
290 unsigned seq;
291
292 seq = read_seqcount_begin(&obj->seq);
293
294 rcu_read_lock();
295
296 fobj = rcu_dereference(obj->fence);
297 if (fobj) {
298 struct fence **nshared;
299 size_t sz = sizeof(*shared) * fobj->shared_max;
300
301 nshared = krealloc(shared, sz,
302 GFP_NOWAIT | __GFP_NOWARN);
303 if (!nshared) {
304 rcu_read_unlock();
305 nshared = krealloc(shared, sz, GFP_KERNEL);
306 if (nshared) {
307 shared = nshared;
308 continue;
309 }
310
311 ret = -ENOMEM;
312 shared_count = 0;
313 break;
314 }
315 shared = nshared;
316 memcpy(shared, fobj->shared, sz);
317 shared_count = fobj->shared_count;
318 } else
319 shared_count = 0;
320 fence_excl = rcu_dereference(obj->fence_excl);
321
322 retry = read_seqcount_retry(&obj->seq, seq);
323 if (retry)
324 goto unlock;
325
326 if (!fence_excl || fence_get_rcu(fence_excl)) {
327 unsigned i;
328
329 for (i = 0; i < shared_count; ++i) {
330 if (fence_get_rcu(shared[i]))
331 continue;
332
333
334 while (i--)
335 fence_put(shared[i]);
336
337 if (fence_excl) {
338 fence_put(fence_excl);
339 fence_excl = NULL;
340 }
341
342 retry = 1;
343 break;
344 }
345 } else
346 retry = 1;
347
348unlock:
349 rcu_read_unlock();
350 }
351 *pshared_count = shared_count;
352 if (shared_count)
353 *pshared = shared;
354 else {
355 *pshared = NULL;
356 kfree(shared);
357 }
358 *pfence_excl = fence_excl;
359
360 return ret;
361}
362EXPORT_SYMBOL_GPL(reservation_object_get_fences_rcu);
363
364
365
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371
372
373
374
375
376long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
377 bool wait_all, bool intr,
378 unsigned long timeout)
379{
380 struct fence *fence;
381 unsigned seq, shared_count, i = 0;
382 long ret = timeout;
383
384 if (!timeout)
385 return reservation_object_test_signaled_rcu(obj, wait_all);
386
387retry:
388 fence = NULL;
389 shared_count = 0;
390 seq = read_seqcount_begin(&obj->seq);
391 rcu_read_lock();
392
393 if (wait_all) {
394 struct reservation_object_list *fobj =
395 rcu_dereference(obj->fence);
396
397 if (fobj)
398 shared_count = fobj->shared_count;
399
400 if (read_seqcount_retry(&obj->seq, seq))
401 goto unlock_retry;
402
403 for (i = 0; i < shared_count; ++i) {
404 struct fence *lfence = rcu_dereference(fobj->shared[i]);
405
406 if (test_bit(FENCE_FLAG_SIGNALED_BIT, &lfence->flags))
407 continue;
408
409 if (!fence_get_rcu(lfence))
410 goto unlock_retry;
411
412 if (fence_is_signaled(lfence)) {
413 fence_put(lfence);
414 continue;
415 }
416
417 fence = lfence;
418 break;
419 }
420 }
421
422 if (!shared_count) {
423 struct fence *fence_excl = rcu_dereference(obj->fence_excl);
424
425 if (read_seqcount_retry(&obj->seq, seq))
426 goto unlock_retry;
427
428 if (fence_excl &&
429 !test_bit(FENCE_FLAG_SIGNALED_BIT, &fence_excl->flags)) {
430 if (!fence_get_rcu(fence_excl))
431 goto unlock_retry;
432
433 if (fence_is_signaled(fence_excl))
434 fence_put(fence_excl);
435 else
436 fence = fence_excl;
437 }
438 }
439
440 rcu_read_unlock();
441 if (fence) {
442 ret = fence_wait_timeout(fence, intr, ret);
443 fence_put(fence);
444 if (ret > 0 && wait_all && (i + 1 < shared_count))
445 goto retry;
446 }
447 return ret;
448
449unlock_retry:
450 rcu_read_unlock();
451 goto retry;
452}
453EXPORT_SYMBOL_GPL(reservation_object_wait_timeout_rcu);
454
455
456static inline int
457reservation_object_test_signaled_single(struct fence *passed_fence)
458{
459 struct fence *fence, *lfence = passed_fence;
460 int ret = 1;
461
462 if (!test_bit(FENCE_FLAG_SIGNALED_BIT, &lfence->flags)) {
463 fence = fence_get_rcu(lfence);
464 if (!fence)
465 return -1;
466
467 ret = !!fence_is_signaled(fence);
468 fence_put(fence);
469 }
470 return ret;
471}
472
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477
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480
481
482
483bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
484 bool test_all)
485{
486 unsigned seq, shared_count;
487 int ret = true;
488
489retry:
490 shared_count = 0;
491 seq = read_seqcount_begin(&obj->seq);
492 rcu_read_lock();
493
494 if (test_all) {
495 unsigned i;
496
497 struct reservation_object_list *fobj =
498 rcu_dereference(obj->fence);
499
500 if (fobj)
501 shared_count = fobj->shared_count;
502
503 if (read_seqcount_retry(&obj->seq, seq))
504 goto unlock_retry;
505
506 for (i = 0; i < shared_count; ++i) {
507 struct fence *fence = rcu_dereference(fobj->shared[i]);
508
509 ret = reservation_object_test_signaled_single(fence);
510 if (ret < 0)
511 goto unlock_retry;
512 else if (!ret)
513 break;
514 }
515
516
517
518
519
520
521
522 }
523
524 if (!shared_count) {
525 struct fence *fence_excl = rcu_dereference(obj->fence_excl);
526
527 if (read_seqcount_retry(&obj->seq, seq))
528 goto unlock_retry;
529
530 if (fence_excl) {
531 ret = reservation_object_test_signaled_single(
532 fence_excl);
533 if (ret < 0)
534 goto unlock_retry;
535 }
536 }
537
538 rcu_read_unlock();
539 return ret;
540
541unlock_retry:
542 rcu_read_unlock();
543 goto retry;
544}
545EXPORT_SYMBOL_GPL(reservation_object_test_signaled_rcu);
546