2 * SPDX-License-Identifier: MIT
4 * (C) Copyright 2016 Intel Corporation
7 #include <linux/slab.h>
8 #include <linux/dma-fence.h>
9 #include <linux/irq_work.h>
10 #include <linux/dma-resv.h>
12 #include "i915_sw_fence.h"
13 #include "i915_selftest.h"
15 #define I915_SW_FENCE_FLAG_ALLOC BIT(3) /* after WQ_FLAG_* for safety */
17 static DEFINE_SPINLOCK(i915_sw_fence_lock);
24 static void *i915_sw_fence_debug_hint(void *addr)
26 return (void *)(((struct i915_sw_fence *)addr)->flags & I915_SW_FENCE_MASK);
29 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
31 static struct debug_obj_descr i915_sw_fence_debug_descr = {
32 .name = "i915_sw_fence",
33 .debug_hint = i915_sw_fence_debug_hint,
36 static inline void debug_fence_init(struct i915_sw_fence *fence)
38 debug_object_init(fence, &i915_sw_fence_debug_descr);
41 static inline void debug_fence_init_onstack(struct i915_sw_fence *fence)
43 debug_object_init_on_stack(fence, &i915_sw_fence_debug_descr);
46 static inline void debug_fence_activate(struct i915_sw_fence *fence)
48 debug_object_activate(fence, &i915_sw_fence_debug_descr);
51 static inline void debug_fence_set_state(struct i915_sw_fence *fence,
54 debug_object_active_state(fence, &i915_sw_fence_debug_descr, old, new);
57 static inline void debug_fence_deactivate(struct i915_sw_fence *fence)
59 debug_object_deactivate(fence, &i915_sw_fence_debug_descr);
62 static inline void debug_fence_destroy(struct i915_sw_fence *fence)
64 debug_object_destroy(fence, &i915_sw_fence_debug_descr);
67 static inline void debug_fence_free(struct i915_sw_fence *fence)
69 debug_object_free(fence, &i915_sw_fence_debug_descr);
70 smp_wmb(); /* flush the change in state before reallocation */
73 static inline void debug_fence_assert(struct i915_sw_fence *fence)
75 debug_object_assert_init(fence, &i915_sw_fence_debug_descr);
80 static inline void debug_fence_init(struct i915_sw_fence *fence)
84 static inline void debug_fence_init_onstack(struct i915_sw_fence *fence)
88 static inline void debug_fence_activate(struct i915_sw_fence *fence)
92 static inline void debug_fence_set_state(struct i915_sw_fence *fence,
97 static inline void debug_fence_deactivate(struct i915_sw_fence *fence)
101 static inline void debug_fence_destroy(struct i915_sw_fence *fence)
105 static inline void debug_fence_free(struct i915_sw_fence *fence)
109 static inline void debug_fence_assert(struct i915_sw_fence *fence)
115 static int __i915_sw_fence_notify(struct i915_sw_fence *fence,
116 enum i915_sw_fence_notify state)
118 i915_sw_fence_notify_t fn;
120 fn = (i915_sw_fence_notify_t)(fence->flags & I915_SW_FENCE_MASK);
121 return fn(fence, state);
124 #ifdef CONFIG_DRM_I915_SW_FENCE_DEBUG_OBJECTS
125 void i915_sw_fence_fini(struct i915_sw_fence *fence)
127 debug_fence_free(fence);
131 static void __i915_sw_fence_wake_up_all(struct i915_sw_fence *fence,
132 struct list_head *continuation)
134 wait_queue_head_t *x = &fence->wait;
135 wait_queue_entry_t *pos, *next;
138 debug_fence_deactivate(fence);
139 atomic_set_release(&fence->pending, -1); /* 0 -> -1 [done] */
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).
148 spin_lock_irqsave_nested(&x->lock, flags, 1 + !!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);
154 list_move_tail(&pos->entry, continuation);
160 list_for_each_entry_safe(pos, next, &x->head, entry) {
162 TASK_NORMAL, fence->error,
166 if (list_empty(&extra))
169 list_splice_tail_init(&extra, &x->head);
172 spin_unlock_irqrestore(&x->lock, flags);
174 debug_fence_assert(fence);
177 static void __i915_sw_fence_complete(struct i915_sw_fence *fence,
178 struct list_head *continuation)
180 debug_fence_assert(fence);
182 if (!atomic_dec_and_test(&fence->pending))
185 debug_fence_set_state(fence, DEBUG_FENCE_IDLE, DEBUG_FENCE_NOTIFY);
187 if (__i915_sw_fence_notify(fence, FENCE_COMPLETE) != NOTIFY_DONE)
190 debug_fence_set_state(fence, DEBUG_FENCE_NOTIFY, DEBUG_FENCE_IDLE);
192 __i915_sw_fence_wake_up_all(fence, continuation);
194 debug_fence_destroy(fence);
195 __i915_sw_fence_notify(fence, FENCE_FREE);
198 void i915_sw_fence_complete(struct i915_sw_fence *fence)
200 debug_fence_assert(fence);
202 if (WARN_ON(i915_sw_fence_done(fence)))
205 __i915_sw_fence_complete(fence, NULL);
208 void i915_sw_fence_await(struct i915_sw_fence *fence)
210 debug_fence_assert(fence);
211 WARN_ON(atomic_inc_return(&fence->pending) <= 1);
214 void __i915_sw_fence_init(struct i915_sw_fence *fence,
215 i915_sw_fence_notify_t fn,
217 struct lock_class_key *key)
219 BUG_ON(!fn || (unsigned long)fn & ~I915_SW_FENCE_MASK);
221 debug_fence_init(fence);
223 __init_waitqueue_head(&fence->wait, name, key);
224 atomic_set(&fence->pending, 1);
227 fence->flags = (unsigned long)fn;
230 void i915_sw_fence_commit(struct i915_sw_fence *fence)
232 debug_fence_activate(fence);
233 i915_sw_fence_complete(fence);
236 static int i915_sw_fence_wake(wait_queue_entry_t *wq, unsigned mode, int flags, void *key)
238 i915_sw_fence_set_error_once(wq->private, flags);
240 list_del(&wq->entry);
241 __i915_sw_fence_complete(wq->private, key);
243 if (wq->flags & I915_SW_FENCE_FLAG_ALLOC)
248 static bool __i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
249 const struct i915_sw_fence * const signaler)
251 wait_queue_entry_t *wq;
253 if (__test_and_set_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
256 if (fence == signaler)
259 list_for_each_entry(wq, &fence->wait.head, entry) {
260 if (wq->func != i915_sw_fence_wake)
263 if (__i915_sw_fence_check_if_after(wq->private, signaler))
270 static void __i915_sw_fence_clear_checked_bit(struct i915_sw_fence *fence)
272 wait_queue_entry_t *wq;
274 if (!__test_and_clear_bit(I915_SW_FENCE_CHECKED_BIT, &fence->flags))
277 list_for_each_entry(wq, &fence->wait.head, entry) {
278 if (wq->func != i915_sw_fence_wake)
281 __i915_sw_fence_clear_checked_bit(wq->private);
285 static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
286 const struct i915_sw_fence * const signaler)
291 if (!IS_ENABLED(CONFIG_DRM_I915_SW_FENCE_CHECK_DAG))
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);
302 static 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)
309 debug_fence_assert(fence);
310 might_sleep_if(gfpflags_allow_blocking(gfp));
312 if (i915_sw_fence_done(signaler)) {
313 i915_sw_fence_set_error_once(fence, signaler->error);
317 debug_fence_assert(signaler);
319 /* The dependency graph must be acyclic. */
320 if (unlikely(i915_sw_fence_check_if_after(fence, signaler)))
325 wq = kmalloc(sizeof(*wq), gfp);
327 if (!gfpflags_allow_blocking(gfp))
330 i915_sw_fence_wait(signaler);
331 i915_sw_fence_set_error_once(fence, signaler->error);
335 pending |= I915_SW_FENCE_FLAG_ALLOC;
338 INIT_LIST_HEAD(&wq->entry);
340 wq->func = i915_sw_fence_wake;
343 i915_sw_fence_await(fence);
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);
350 i915_sw_fence_wake(wq, 0, signaler->error, NULL);
353 spin_unlock_irqrestore(&signaler->wait.lock, flags);
358 int i915_sw_fence_await_sw_fence(struct i915_sw_fence *fence,
359 struct i915_sw_fence *signaler,
360 wait_queue_entry_t *wq)
362 return __i915_sw_fence_await_sw_fence(fence, signaler, wq, 0);
365 int i915_sw_fence_await_sw_fence_gfp(struct i915_sw_fence *fence,
366 struct i915_sw_fence *signaler,
369 return __i915_sw_fence_await_sw_fence(fence, signaler, NULL, gfp);
372 struct 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;
380 static void dma_i915_sw_fence_wake(struct dma_fence *dma,
381 struct dma_fence_cb *data)
383 struct i915_sw_dma_fence_cb *cb = container_of(data, typeof(*cb), base);
385 i915_sw_fence_set_error_once(cb->fence, dma->error);
386 i915_sw_fence_complete(cb->fence);
390 static void timer_i915_sw_fence_wake(struct timer_list *t)
392 struct i915_sw_dma_fence_cb_timer *cb = from_timer(cb, t, timer);
393 struct i915_sw_fence *fence;
395 fence = xchg(&cb->base.fence, NULL);
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),
403 i915_sw_fence_debug_hint(fence));
405 i915_sw_fence_set_error_once(fence, -ETIMEDOUT);
406 i915_sw_fence_complete(fence);
409 static void dma_i915_sw_fence_wake_timer(struct dma_fence *dma,
410 struct dma_fence_cb *data)
412 struct i915_sw_dma_fence_cb_timer *cb =
413 container_of(data, typeof(*cb), base.base);
414 struct i915_sw_fence *fence;
416 fence = xchg(&cb->base.fence, NULL);
418 i915_sw_fence_complete(fence);
420 irq_work_queue(&cb->work);
423 static void irq_i915_sw_fence_work(struct irq_work *wrk)
425 struct i915_sw_dma_fence_cb_timer *cb =
426 container_of(wrk, typeof(*cb), work);
428 del_timer_sync(&cb->timer);
429 dma_fence_put(cb->dma);
434 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
435 struct dma_fence *dma,
436 unsigned long timeout,
439 struct i915_sw_dma_fence_cb *cb;
440 dma_fence_func_t func;
443 debug_fence_assert(fence);
444 might_sleep_if(gfpflags_allow_blocking(gfp));
446 if (dma_fence_is_signaled(dma))
449 cb = kmalloc(timeout ?
450 sizeof(struct i915_sw_dma_fence_cb_timer) :
451 sizeof(struct i915_sw_dma_fence_cb),
454 if (!gfpflags_allow_blocking(gfp))
457 return dma_fence_wait(dma, false);
461 i915_sw_fence_await(fence);
463 func = dma_i915_sw_fence_wake;
465 struct i915_sw_dma_fence_cb_timer *timer =
466 container_of(cb, typeof(*timer), base);
468 timer->dma = dma_fence_get(dma);
469 init_irq_work(&timer->work, irq_i915_sw_fence_work);
471 timer_setup(&timer->timer,
472 timer_i915_sw_fence_wake, TIMER_IRQSAFE);
473 mod_timer(&timer->timer, round_jiffies_up(jiffies + timeout));
475 func = dma_i915_sw_fence_wake_timer;
478 ret = dma_fence_add_callback(dma, &cb->base, func);
482 func(dma, &cb->base);
483 if (ret == -ENOENT) /* fence already signaled */
490 static void __dma_i915_sw_fence_wake(struct dma_fence *dma,
491 struct dma_fence_cb *data)
493 struct i915_sw_dma_fence_cb *cb = container_of(data, typeof(*cb), base);
495 i915_sw_fence_set_error_once(cb->fence, dma->error);
496 i915_sw_fence_complete(cb->fence);
499 int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
500 struct dma_fence *dma,
501 struct i915_sw_dma_fence_cb *cb)
505 debug_fence_assert(fence);
507 if (dma_fence_is_signaled(dma))
511 i915_sw_fence_await(fence);
513 ret = dma_fence_add_callback(dma, &cb->base, __dma_i915_sw_fence_wake);
517 __dma_i915_sw_fence_wake(dma, &cb->base);
518 if (ret == -ENOENT) /* fence already signaled */
525 int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
526 struct dma_resv *resv,
527 const struct dma_fence_ops *exclude,
529 unsigned long timeout,
532 struct dma_fence *excl;
533 int ret = 0, pending;
535 debug_fence_assert(fence);
536 might_sleep_if(gfpflags_allow_blocking(gfp));
539 struct dma_fence **shared;
540 unsigned int count, i;
542 ret = dma_resv_get_fences_rcu(resv,
543 &excl, &count, &shared);
547 for (i = 0; i < count; i++) {
548 if (shared[i]->ops == exclude)
551 pending = i915_sw_fence_await_dma_fence(fence,
563 for (i = 0; i < count; i++)
564 dma_fence_put(shared[i]);
567 excl = dma_resv_get_excl_rcu(resv);
570 if (ret >= 0 && excl && excl->ops != exclude) {
571 pending = i915_sw_fence_await_dma_fence(fence,
586 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
587 #include "selftests/lib_sw_fence.c"
588 #include "selftests/i915_sw_fence.c"