Loading...
Note: File does not exist in v3.1.
1/*
2 * SPDX-License-Identifier: MIT
3 *
4 * (C) Copyright 2016 Intel Corporation
5 */
6
7#include <linux/slab.h>
8#include <linux/dma-fence.h>
9#include <linux/irq_work.h>
10#include <linux/dma-resv.h>
11
12#include "i915_sw_fence.h"
13#include "i915_selftest.h"
14
15#define I915_SW_FENCE_FLAG_ALLOC BIT(3) /* after WQ_FLAG_* for safety */
16
17static DEFINE_SPINLOCK(i915_sw_fence_lock);
18
19enum {
20 DEBUG_FENCE_IDLE = 0,
21 DEBUG_FENCE_NOTIFY,
22};
23
24static void *i915_sw_fence_debug_hint(void *addr)
25{
26 return (void *)(((struct i915_sw_fence *)addr)->flags & I915_SW_FENCE_MASK);
27}
28
29#ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
30
31static struct debug_obj_descr i915_sw_fence_debug_descr = {
32 .name = "i915_sw_fence",
33 .debug_hint = i915_sw_fence_debug_hint,
34};
35
36static inline void debug_fence_init(struct i915_sw_fence *fence)
37{
38 debug_object_init(fence, &i915_sw_fence_debug_descr);
39}
40
41static inline void debug_fence_init_onstack(struct i915_sw_fence *fence)
42{
43 debug_object_init_on_stack(fence, &i915_sw_fence_debug_descr);
44}
45
46static inline void debug_fence_activate(struct i915_sw_fence *fence)
47{
48 debug_object_activate(fence, &i915_sw_fence_debug_descr);
49}
50
51static inline void debug_fence_set_state(struct i915_sw_fence *fence,
52 int old, int new)
53{
54 debug_object_active_state(fence, &i915_sw_fence_debug_descr, old, new);
55}
56
57static inline void debug_fence_deactivate(struct i915_sw_fence *fence)
58{
59 debug_object_deactivate(fence, &i915_sw_fence_debug_descr);
60}
61
62static inline void debug_fence_destroy(struct i915_sw_fence *fence)
63{
64 debug_object_destroy(fence, &i915_sw_fence_debug_descr);
65}
66
67static inline void debug_fence_free(struct i915_sw_fence *fence)
68{
69 debug_object_free(fence, &i915_sw_fence_debug_descr);
70 smp_wmb(); /* flush the change in state before reallocation */
71}
72
73static inline void debug_fence_assert(struct i915_sw_fence *fence)
74{
75 debug_object_assert_init(fence, &i915_sw_fence_debug_descr);
76}
77
78#else
79
80static inline void debug_fence_init(struct i915_sw_fence *fence)
81{
82}
83
84static inline void debug_fence_init_onstack(struct i915_sw_fence *fence)
85{
86}
87
88static inline void debug_fence_activate(struct i915_sw_fence *fence)
89{
90}
91
92static inline void debug_fence_set_state(struct i915_sw_fence *fence,
93 int old, int new)
94{
95}
96
97static inline void debug_fence_deactivate(struct i915_sw_fence *fence)
98{
99}
100
101static inline void debug_fence_destroy(struct i915_sw_fence *fence)
102{
103}
104
105static inline void debug_fence_free(struct i915_sw_fence *fence)
106{
107}
108
109static inline void debug_fence_assert(struct i915_sw_fence *fence)
110{
111}
112
113#endif
114
115static int __i915_sw_fence_notify(struct i915_sw_fence *fence,
116 enum i915_sw_fence_notify state)
117{
118 i915_sw_fence_notify_t fn;
119
120 fn = (i915_sw_fence_notify_t)(fence->flags & I915_SW_FENCE_MASK);
121 return fn(fence, state);
122}
123
124#ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
125void i915_sw_fence_fini(struct i915_sw_fence *fence)
126{
127 debug_fence_free(fence);
128}
129#endif
130
131static void __i915_sw_fence_wake_up_all(struct i915_sw_fence *fence,
132 struct list_head *continuation)
133{
134 wait_queue_head_t *x = &fence->wait;
135 wait_queue_entry_t *pos, *next;
136 unsigned long flags;
137
138 debug_fence_deactivate(fence);
139 atomic_set_release(&fence->pending, -1); /* 0 -> -1 [done] */
140
141 /*
142 * To prevent unbounded recursion as we traverse the graph of
143 * i915_sw_fences, we move the entry list from this, the next ready
144 * fence, to the tail of the original fence's entry list
145 * (and so added to the list to be woken).
146 */
147
148 spin_lock_irqsave_nested(&x->lock, flags, 1 + !!continuation);
149 if (continuation) {
150 list_for_each_entry_safe(pos, next, &x->head, entry) {
151 if (pos->func == autoremove_wake_function)
152 pos->func(pos, TASK_NORMAL, 0, continuation);
153 else
154 list_move_tail(&pos->entry, continuation);
155 }
156 } else {
157 LIST_HEAD(extra);
158
159 do {
160 list_for_each_entry_safe(pos, next, &x->head, entry) {
161 pos->func(pos,
162 TASK_NORMAL, fence->error,
163 &extra);
164 }
165
166 if (list_empty(&extra))
167 break;
168
169 list_splice_tail_init(&extra, &x->head);
170 } while (1);
171 }
172 spin_unlock_irqrestore(&x->lock, flags);
173
174 debug_fence_assert(fence);
175}
176
177static void __i915_sw_fence_complete(struct i915_sw_fence *fence,
178 struct list_head *continuation)
179{
180 debug_fence_assert(fence);
181
182 if (!atomic_dec_and_test(&fence->pending))
183 return;
184
185 debug_fence_set_state(fence, DEBUG_FENCE_IDLE, DEBUG_FENCE_NOTIFY);
186
187 if (__i915_sw_fence_notify(fence, FENCE_COMPLETE) != NOTIFY_DONE)
188 return;
189
190 debug_fence_set_state(fence, DEBUG_FENCE_NOTIFY, DEBUG_FENCE_IDLE);
191
192 __i915_sw_fence_wake_up_all(fence, continuation);
193
194 debug_fence_destroy(fence);
195 __i915_sw_fence_notify(fence, FENCE_FREE);
196}
197
198void i915_sw_fence_complete(struct i915_sw_fence *fence)
199{
200 debug_fence_assert(fence);
201
202 if (WARN_ON(i915_sw_fence_done(fence)))
203 return;
204
205 __i915_sw_fence_complete(fence, NULL);
206}
207
208void i915_sw_fence_await(struct i915_sw_fence *fence)
209{
210 debug_fence_assert(fence);
211 WARN_ON(atomic_inc_return(&fence->pending) <= 1);
212}
213
214void __i915_sw_fence_init(struct i915_sw_fence *fence,
215 i915_sw_fence_notify_t fn,
216 const char *name,
217 struct lock_class_key *key)
218{
219 BUG_ON(!fn || (unsigned long)fn & ~I915_SW_FENCE_MASK);
220
221 debug_fence_init(fence);
222
223 __init_waitqueue_head(&fence->wait, name, key);
224 atomic_set(&fence->pending, 1);
225 fence->error = 0;
226
227 fence->flags = (unsigned long)fn;
228}
229
230void i915_sw_fence_commit(struct i915_sw_fence *fence)
231{
232 debug_fence_activate(fence);
233 i915_sw_fence_complete(fence);
234}
235
236static int i915_sw_fence_wake(wait_queue_entry_t *wq, unsigned mode, int flags, void *key)
237{
238 i915_sw_fence_set_error_once(wq->private, flags);
239
240 list_del(&wq->entry);
241 __i915_sw_fence_complete(wq->private, key);
242
243 if (wq->flags & I915_SW_FENCE_FLAG_ALLOC)
244 kfree(wq);
245 return 0;
246}
247
248static bool __i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
249 const struct i915_sw_fence * const signaler)
250{
251 wait_queue_entry_t *wq;
252
253 if (__test_and_set_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
254 return false;
255
256 if (fence == signaler)
257 return true;
258
259 list_for_each_entry(wq, &fence->wait.head, entry) {
260 if (wq->func != i915_sw_fence_wake)
261 continue;
262
263 if (__i915_sw_fence_check_if_after(wq->private, signaler))
264 return true;
265 }
266
267 return false;
268}
269
270static void __i915_sw_fence_clear_checked_bit(struct i915_sw_fence *fence)
271{
272 wait_queue_entry_t *wq;
273
274 if (!__test_and_clear_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
275 return;
276
277 list_for_each_entry(wq, &fence->wait.head, entry) {
278 if (wq->func != i915_sw_fence_wake)
279 continue;
280
281 __i915_sw_fence_clear_checked_bit(wq->private);
282 }
283}
284
285static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
286 const struct i915_sw_fence * const signaler)
287{
288 unsigned long flags;
289 bool err;
290
291 if (!IS_ENABLED(CONFIG_DRM_I915_SW_FENCE_CHECK_DAG))
292 return false;
293
294 spin_lock_irqsave(&i915_sw_fence_lock, flags);
295 err = __i915_sw_fence_check_if_after(fence, signaler);
296 __i915_sw_fence_clear_checked_bit(fence);
297 spin_unlock_irqrestore(&i915_sw_fence_lock, flags);
298
299 return err;
300}
301
302static int __i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
303 struct i915_sw_fence *signaler,
304 wait_queue_entry_t *wq, gfp_t gfp)
305{
306 unsigned long flags;
307 int pending;
308
309 debug_fence_assert(fence);
310 might_sleep_if(gfpflags_allow_blocking(gfp));
311
312 if (i915_sw_fence_done(signaler)) {
313 i915_sw_fence_set_error_once(fence, signaler->error);
314 return 0;
315 }
316
317 debug_fence_assert(signaler);
318
319 /* The dependency graph must be acyclic. */
320 if (unlikely(i915_sw_fence_check_if_after(fence, signaler)))
321 return -EINVAL;
322
323 pending = 0;
324 if (!wq) {
325 wq = kmalloc(sizeof(*wq), gfp);
326 if (!wq) {
327 if (!gfpflags_allow_blocking(gfp))
328 return -ENOMEM;
329
330 i915_sw_fence_wait(signaler);
331 i915_sw_fence_set_error_once(fence, signaler->error);
332 return 0;
333 }
334
335 pending |= I915_SW_FENCE_FLAG_ALLOC;
336 }
337
338 INIT_LIST_HEAD(&wq->entry);
339 wq->flags = pending;
340 wq->func = i915_sw_fence_wake;
341 wq->private = fence;
342
343 i915_sw_fence_await(fence);
344
345 spin_lock_irqsave(&signaler->wait.lock, flags);
346 if (likely(!i915_sw_fence_done(signaler))) {
347 __add_wait_queue_entry_tail(&signaler->wait, wq);
348 pending = 1;
349 } else {
350 i915_sw_fence_wake(wq, 0, signaler->error, NULL);
351 pending = 0;
352 }
353 spin_unlock_irqrestore(&signaler->wait.lock, flags);
354
355 return pending;
356}
357
358int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
359 struct i915_sw_fence *signaler,
360 wait_queue_entry_t *wq)
361{
362 return __i915_sw_fence_await_sw_fence(fence, signaler, wq, 0);
363}
364
365int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
366 struct i915_sw_fence *signaler,
367 gfp_t gfp)
368{
369 return __i915_sw_fence_await_sw_fence(fence, signaler, NULL, gfp);
370}
371
372struct i915_sw_dma_fence_cb_timer {
373 struct i915_sw_dma_fence_cb base;
374 struct dma_fence *dma;
375 struct timer_list timer;
376 struct irq_work work;
377 struct rcu_head rcu;
378};
379
380static void dma_i915_sw_fence_wake(struct dma_fence *dma,
381 struct dma_fence_cb *data)
382{
383 struct i915_sw_dma_fence_cb *cb = container_of(data, typeof(*cb), base);
384
385 i915_sw_fence_set_error_once(cb->fence, dma->error);
386 i915_sw_fence_complete(cb->fence);
387 kfree(cb);
388}
389
390static void timer_i915_sw_fence_wake(struct timer_list *t)
391{
392 struct i915_sw_dma_fence_cb_timer *cb = from_timer(cb, t, timer);
393 struct i915_sw_fence *fence;
394
395 fence = xchg(&cb->base.fence, NULL);
396 if (!fence)
397 return;
398
399 pr_notice("Asynchronous wait on fence %s:%s:%llx timed out (hint:%pS)\n",
400 cb->dma->ops->get_driver_name(cb->dma),
401 cb->dma->ops->get_timeline_name(cb->dma),
402 cb->dma->seqno,
403 i915_sw_fence_debug_hint(fence));
404
405 i915_sw_fence_set_error_once(fence, -ETIMEDOUT);
406 i915_sw_fence_complete(fence);
407}
408
409static void dma_i915_sw_fence_wake_timer(struct dma_fence *dma,
410 struct dma_fence_cb *data)
411{
412 struct i915_sw_dma_fence_cb_timer *cb =
413 container_of(data, typeof(*cb), base.base);
414 struct i915_sw_fence *fence;
415
416 fence = xchg(&cb->base.fence, NULL);
417 if (fence)
418 i915_sw_fence_complete(fence);
419
420 irq_work_queue(&cb->work);
421}
422
423static void irq_i915_sw_fence_work(struct irq_work *wrk)
424{
425 struct i915_sw_dma_fence_cb_timer *cb =
426 container_of(wrk, typeof(*cb), work);
427
428 del_timer_sync(&cb->timer);
429 dma_fence_put(cb->dma);
430
431 kfree_rcu(cb, rcu);
432}
433
434int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
435 struct dma_fence *dma,
436 unsigned long timeout,
437 gfp_t gfp)
438{
439 struct i915_sw_dma_fence_cb *cb;
440 dma_fence_func_t func;
441 int ret;
442
443 debug_fence_assert(fence);
444 might_sleep_if(gfpflags_allow_blocking(gfp));
445
446 if (dma_fence_is_signaled(dma))
447 return 0;
448
449 cb = kmalloc(timeout ?
450 sizeof(struct i915_sw_dma_fence_cb_timer) :
451 sizeof(struct i915_sw_dma_fence_cb),
452 gfp);
453 if (!cb) {
454 if (!gfpflags_allow_blocking(gfp))
455 return -ENOMEM;
456
457 return dma_fence_wait(dma, false);
458 }
459
460 cb->fence = fence;
461 i915_sw_fence_await(fence);
462
463 func = dma_i915_sw_fence_wake;
464 if (timeout) {
465 struct i915_sw_dma_fence_cb_timer *timer =
466 container_of(cb, typeof(*timer), base);
467
468 timer->dma = dma_fence_get(dma);
469 init_irq_work(&timer->work, irq_i915_sw_fence_work);
470
471 timer_setup(&timer->timer,
472 timer_i915_sw_fence_wake, TIMER_IRQSAFE);
473 mod_timer(&timer->timer, round_jiffies_up(jiffies + timeout));
474
475 func = dma_i915_sw_fence_wake_timer;
476 }
477
478 ret = dma_fence_add_callback(dma, &cb->base, func);
479 if (ret == 0) {
480 ret = 1;
481 } else {
482 func(dma, &cb->base);
483 if (ret == -ENOENT) /* fence already signaled */
484 ret = 0;
485 }
486
487 return ret;
488}
489
490static void __dma_i915_sw_fence_wake(struct dma_fence *dma,
491 struct dma_fence_cb *data)
492{
493 struct i915_sw_dma_fence_cb *cb = container_of(data, typeof(*cb), base);
494
495 i915_sw_fence_set_error_once(cb->fence, dma->error);
496 i915_sw_fence_complete(cb->fence);
497}
498
499int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
500 struct dma_fence *dma,
501 struct i915_sw_dma_fence_cb *cb)
502{
503 int ret;
504
505 debug_fence_assert(fence);
506
507 if (dma_fence_is_signaled(dma))
508 return 0;
509
510 cb->fence = fence;
511 i915_sw_fence_await(fence);
512
513 ret = dma_fence_add_callback(dma, &cb->base, __dma_i915_sw_fence_wake);
514 if (ret == 0) {
515 ret = 1;
516 } else {
517 __dma_i915_sw_fence_wake(dma, &cb->base);
518 if (ret == -ENOENT) /* fence already signaled */
519 ret = 0;
520 }
521
522 return ret;
523}
524
525int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
526 struct dma_resv *resv,
527 const struct dma_fence_ops *exclude,
528 bool write,
529 unsigned long timeout,
530 gfp_t gfp)
531{
532 struct dma_fence *excl;
533 int ret = 0, pending;
534
535 debug_fence_assert(fence);
536 might_sleep_if(gfpflags_allow_blocking(gfp));
537
538 if (write) {
539 struct dma_fence **shared;
540 unsigned int count, i;
541
542 ret = dma_resv_get_fences_rcu(resv,
543 &excl, &count, &shared);
544 if (ret)
545 return ret;
546
547 for (i = 0; i < count; i++) {
548 if (shared[i]->ops == exclude)
549 continue;
550
551 pending = i915_sw_fence_await_dma_fence(fence,
552 shared[i],
553 timeout,
554 gfp);
555 if (pending < 0) {
556 ret = pending;
557 break;
558 }
559
560 ret |= pending;
561 }
562
563 for (i = 0; i < count; i++)
564 dma_fence_put(shared[i]);
565 kfree(shared);
566 } else {
567 excl = dma_resv_get_excl_rcu(resv);
568 }
569
570 if (ret >= 0 && excl && excl->ops != exclude) {
571 pending = i915_sw_fence_await_dma_fence(fence,
572 excl,
573 timeout,
574 gfp);
575 if (pending < 0)
576 ret = pending;
577 else
578 ret |= pending;
579 }
580
581 dma_fence_put(excl);
582
583 return ret;
584}
585
586#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
587#include "selftests/lib_sw_fence.c"
588#include "selftests/i915_sw_fence.c"
589#endif