2 * Copyright © 2008-2015 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
25 #include <linux/prefetch.h>
29 static const char *i915_fence_get_driver_name(struct fence *fence)
34 static const char *i915_fence_get_timeline_name(struct fence *fence)
36 /* Timelines are bound by eviction to a VM. However, since
37 * we only have a global seqno at the moment, we only have
38 * a single timeline. Note that each timeline will have
39 * multiple execution contexts (fence contexts) as we allow
40 * engines within a single timeline to execute in parallel.
45 static bool i915_fence_signaled(struct fence *fence)
47 return i915_gem_request_completed(to_request(fence));
50 static bool i915_fence_enable_signaling(struct fence *fence)
52 if (i915_fence_signaled(fence))
55 intel_engine_enable_signaling(to_request(fence));
59 static signed long i915_fence_wait(struct fence *fence,
61 signed long timeout_jiffies)
63 s64 timeout_ns, *timeout;
66 if (timeout_jiffies != MAX_SCHEDULE_TIMEOUT) {
67 timeout_ns = jiffies_to_nsecs(timeout_jiffies);
68 timeout = &timeout_ns;
73 ret = i915_wait_request(to_request(fence),
74 interruptible, timeout,
82 if (timeout_jiffies != MAX_SCHEDULE_TIMEOUT)
83 timeout_jiffies = nsecs_to_jiffies(timeout_ns);
85 return timeout_jiffies;
88 static void i915_fence_value_str(struct fence *fence, char *str, int size)
90 snprintf(str, size, "%u", fence->seqno);
93 static void i915_fence_timeline_value_str(struct fence *fence, char *str,
96 snprintf(str, size, "%u",
97 intel_engine_get_seqno(to_request(fence)->engine));
100 static void i915_fence_release(struct fence *fence)
102 struct drm_i915_gem_request *req = to_request(fence);
104 kmem_cache_free(req->i915->requests, req);
107 const struct fence_ops i915_fence_ops = {
108 .get_driver_name = i915_fence_get_driver_name,
109 .get_timeline_name = i915_fence_get_timeline_name,
110 .enable_signaling = i915_fence_enable_signaling,
111 .signaled = i915_fence_signaled,
112 .wait = i915_fence_wait,
113 .release = i915_fence_release,
114 .fence_value_str = i915_fence_value_str,
115 .timeline_value_str = i915_fence_timeline_value_str,
118 int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
119 struct drm_file *file)
121 struct drm_i915_private *dev_private;
122 struct drm_i915_file_private *file_priv;
124 WARN_ON(!req || !file || req->file_priv);
132 dev_private = req->i915;
133 file_priv = file->driver_priv;
135 spin_lock(&file_priv->mm.lock);
136 req->file_priv = file_priv;
137 list_add_tail(&req->client_list, &file_priv->mm.request_list);
138 spin_unlock(&file_priv->mm.lock);
144 i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
146 struct drm_i915_file_private *file_priv = request->file_priv;
151 spin_lock(&file_priv->mm.lock);
152 list_del(&request->client_list);
153 request->file_priv = NULL;
154 spin_unlock(&file_priv->mm.lock);
157 void i915_gem_retire_noop(struct i915_gem_active *active,
158 struct drm_i915_gem_request *request)
160 /* Space left intentionally blank */
163 static void i915_gem_request_retire(struct drm_i915_gem_request *request)
165 struct i915_gem_active *active, *next;
167 trace_i915_gem_request_retire(request);
168 list_del(&request->link);
170 /* We know the GPU must have read the request to have
171 * sent us the seqno + interrupt, so use the position
172 * of tail of the request to update the last known position
175 * Note this requires that we are always called in request
178 list_del(&request->ring_link);
179 request->ring->last_retired_head = request->postfix;
181 /* Walk through the active list, calling retire on each. This allows
182 * objects to track their GPU activity and mark themselves as idle
183 * when their *last* active request is completed (updating state
184 * tracking lists for eviction, active references for GEM, etc).
186 * As the ->retire() may free the node, we decouple it first and
187 * pass along the auxiliary information (to avoid dereferencing
188 * the node after the callback).
190 list_for_each_entry_safe(active, next, &request->active_list, link) {
191 /* In microbenchmarks or focusing upon time inside the kernel,
192 * we may spend an inordinate amount of time simply handling
193 * the retirement of requests and processing their callbacks.
194 * Of which, this loop itself is particularly hot due to the
195 * cache misses when jumping around the list of i915_gem_active.
196 * So we try to keep this loop as streamlined as possible and
197 * also prefetch the next i915_gem_active to try and hide
198 * the likely cache miss.
202 INIT_LIST_HEAD(&active->link);
203 RCU_INIT_POINTER(active->request, NULL);
205 active->retire(active, request);
208 i915_gem_request_remove_from_client(request);
210 if (request->previous_context) {
211 if (i915.enable_execlists)
212 intel_lr_context_unpin(request->previous_context,
216 i915_gem_context_put(request->ctx);
217 i915_gem_request_put(request);
220 void i915_gem_request_retire_upto(struct drm_i915_gem_request *req)
222 struct intel_engine_cs *engine = req->engine;
223 struct drm_i915_gem_request *tmp;
225 lockdep_assert_held(&req->i915->drm.struct_mutex);
226 GEM_BUG_ON(list_empty(&req->link));
229 tmp = list_first_entry(&engine->request_list,
232 i915_gem_request_retire(tmp);
233 } while (tmp != req);
236 static int i915_gem_check_wedge(struct drm_i915_private *dev_priv)
238 struct i915_gpu_error *error = &dev_priv->gpu_error;
240 if (i915_terminally_wedged(error))
243 if (i915_reset_in_progress(error)) {
244 /* Non-interruptible callers can't handle -EAGAIN, hence return
245 * -EIO unconditionally for these.
247 if (!dev_priv->mm.interruptible)
256 static int i915_gem_init_seqno(struct drm_i915_private *dev_priv, u32 seqno)
258 struct intel_engine_cs *engine;
261 /* Carefully retire all requests without writing to the rings */
262 for_each_engine(engine, dev_priv) {
263 ret = intel_engine_idle(engine,
264 I915_WAIT_INTERRUPTIBLE |
269 i915_gem_retire_requests(dev_priv);
271 /* If the seqno wraps around, we need to clear the breadcrumb rbtree */
272 if (!i915_seqno_passed(seqno, dev_priv->next_seqno)) {
273 while (intel_kick_waiters(dev_priv) ||
274 intel_kick_signalers(dev_priv))
278 /* Finally reset hw state */
279 for_each_engine(engine, dev_priv)
280 intel_engine_init_seqno(engine, seqno);
285 int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
287 struct drm_i915_private *dev_priv = to_i915(dev);
293 /* HWS page needs to be set less than what we
294 * will inject to ring
296 ret = i915_gem_init_seqno(dev_priv, seqno - 1);
300 dev_priv->next_seqno = seqno;
304 static int i915_gem_get_seqno(struct drm_i915_private *dev_priv, u32 *seqno)
306 /* reserve 0 for non-seqno */
307 if (unlikely(dev_priv->next_seqno == 0)) {
310 ret = i915_gem_init_seqno(dev_priv, 0);
314 dev_priv->next_seqno = 1;
317 *seqno = dev_priv->next_seqno++;
321 static int __i915_sw_fence_call
322 submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
324 struct drm_i915_gem_request *request =
325 container_of(fence, typeof(*request), submit);
327 /* Will be called from irq-context when using foreign DMA fences */
331 request->engine->last_submitted_seqno = request->fence.seqno;
332 request->engine->submit_request(request);
343 * i915_gem_request_alloc - allocate a request structure
345 * @engine: engine that we wish to issue the request on.
346 * @ctx: context that the request will be associated with.
347 * This can be NULL if the request is not directly related to
348 * any specific user context, in which case this function will
349 * choose an appropriate context to use.
351 * Returns a pointer to the allocated request if successful,
352 * or an error code if not.
354 struct drm_i915_gem_request *
355 i915_gem_request_alloc(struct intel_engine_cs *engine,
356 struct i915_gem_context *ctx)
358 struct drm_i915_private *dev_priv = engine->i915;
359 struct drm_i915_gem_request *req;
363 /* ABI: Before userspace accesses the GPU (e.g. execbuffer), report
364 * EIO if the GPU is already wedged, or EAGAIN to drop the struct_mutex
367 ret = i915_gem_check_wedge(dev_priv);
371 /* Move the oldest request to the slab-cache (if not in use!) */
372 req = list_first_entry_or_null(&engine->request_list,
374 if (req && i915_gem_request_completed(req))
375 i915_gem_request_retire(req);
377 /* Beware: Dragons be flying overhead.
379 * We use RCU to look up requests in flight. The lookups may
380 * race with the request being allocated from the slab freelist.
381 * That is the request we are writing to here, may be in the process
382 * of being read by __i915_gem_active_get_rcu(). As such,
383 * we have to be very careful when overwriting the contents. During
384 * the RCU lookup, we change chase the request->engine pointer,
385 * read the request->fence.seqno and increment the reference count.
387 * The reference count is incremented atomically. If it is zero,
388 * the lookup knows the request is unallocated and complete. Otherwise,
389 * it is either still in use, or has been reallocated and reset
390 * with fence_init(). This increment is safe for release as we check
391 * that the request we have a reference to and matches the active
394 * Before we increment the refcount, we chase the request->engine
395 * pointer. We must not call kmem_cache_zalloc() or else we set
396 * that pointer to NULL and cause a crash during the lookup. If
397 * we see the request is completed (based on the value of the
398 * old engine and seqno), the lookup is complete and reports NULL.
399 * If we decide the request is not completed (new engine or seqno),
400 * then we grab a reference and double check that it is still the
401 * active request - which it won't be and restart the lookup.
403 * Do not use kmem_cache_zalloc() here!
405 req = kmem_cache_alloc(dev_priv->requests, GFP_KERNEL);
407 return ERR_PTR(-ENOMEM);
409 ret = i915_gem_get_seqno(dev_priv, &seqno);
413 spin_lock_init(&req->lock);
414 fence_init(&req->fence,
417 engine->fence_context,
420 i915_sw_fence_init(&req->submit, submit_notify);
422 INIT_LIST_HEAD(&req->active_list);
423 req->i915 = dev_priv;
424 req->engine = engine;
425 req->ctx = i915_gem_context_get(ctx);
427 /* No zalloc, must clear what we need by hand */
428 req->previous_context = NULL;
429 req->file_priv = NULL;
433 * Reserve space in the ring buffer for all the commands required to
434 * eventually emit this request. This is to guarantee that the
435 * i915_add_request() call can't fail. Note that the reserve may need
436 * to be redone if the request is not actually submitted straight
437 * away, e.g. because a GPU scheduler has deferred it.
439 req->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
441 if (i915.enable_execlists)
442 ret = intel_logical_ring_alloc_request_extras(req);
444 ret = intel_ring_alloc_request_extras(req);
448 /* Record the position of the start of the request so that
449 * should we detect the updated seqno part-way through the
450 * GPU processing the request, we never over-estimate the
451 * position of the head.
453 req->head = req->ring->tail;
458 i915_gem_context_put(ctx);
460 kmem_cache_free(dev_priv->requests, req);
465 i915_gem_request_await_request(struct drm_i915_gem_request *to,
466 struct drm_i915_gem_request *from)
470 GEM_BUG_ON(to == from);
472 if (to->engine == from->engine)
475 idx = intel_engine_sync_index(from->engine, to->engine);
476 if (from->fence.seqno <= from->engine->semaphore.sync_seqno[idx])
479 trace_i915_gem_ring_sync_to(to, from);
480 if (!i915.semaphores) {
481 if (!i915_spin_request(from, TASK_INTERRUPTIBLE, 2)) {
482 ret = i915_sw_fence_await_dma_fence(&to->submit,
489 ret = to->engine->semaphore.sync_to(to, from);
494 from->engine->semaphore.sync_seqno[idx] = from->fence.seqno;
499 * i915_gem_request_await_object - set this request to (async) wait upon a bo
501 * @to: request we are wishing to use
502 * @obj: object which may be in use on another ring.
504 * This code is meant to abstract object synchronization with the GPU.
505 * Conceptually we serialise writes between engines inside the GPU.
506 * We only allow one engine to write into a buffer at any time, but
507 * multiple readers. To ensure each has a coherent view of memory, we must:
509 * - If there is an outstanding write request to the object, the new
510 * request must wait for it to complete (either CPU or in hw, requests
511 * on the same ring will be naturally ordered).
513 * - If we are a write request (pending_write_domain is set), the new
514 * request must wait for outstanding read requests to complete.
516 * Returns 0 if successful, else propagates up the lower layer error.
519 i915_gem_request_await_object(struct drm_i915_gem_request *to,
520 struct drm_i915_gem_object *obj,
523 struct i915_gem_active *active;
524 unsigned long active_mask;
528 active_mask = i915_gem_object_get_active(obj);
529 active = obj->last_read;
532 active = &obj->last_write;
535 for_each_active(active_mask, idx) {
536 struct drm_i915_gem_request *request;
539 request = i915_gem_active_peek(&active[idx],
540 &obj->base.dev->struct_mutex);
544 ret = i915_gem_request_await_request(to, request);
552 static void i915_gem_mark_busy(const struct intel_engine_cs *engine)
554 struct drm_i915_private *dev_priv = engine->i915;
556 dev_priv->gt.active_engines |= intel_engine_flag(engine);
557 if (dev_priv->gt.awake)
560 intel_runtime_pm_get_noresume(dev_priv);
561 dev_priv->gt.awake = true;
563 intel_enable_gt_powersave(dev_priv);
564 i915_update_gfx_val(dev_priv);
565 if (INTEL_GEN(dev_priv) >= 6)
566 gen6_rps_busy(dev_priv);
568 queue_delayed_work(dev_priv->wq,
569 &dev_priv->gt.retire_work,
570 round_jiffies_up_relative(HZ));
574 * NB: This function is not allowed to fail. Doing so would mean the the
575 * request is not being tracked for completion but the work itself is
576 * going to happen on the hardware. This would be a Bad Thing(tm).
578 void __i915_add_request(struct drm_i915_gem_request *request, bool flush_caches)
580 struct intel_engine_cs *engine = request->engine;
581 struct intel_ring *ring = request->ring;
582 struct drm_i915_gem_request *prev;
587 trace_i915_gem_request_add(request);
590 * To ensure that this call will not fail, space for its emissions
591 * should already have been reserved in the ring buffer. Let the ring
592 * know that it is time to use that space up.
594 request_start = ring->tail;
595 reserved_tail = request->reserved_space;
596 request->reserved_space = 0;
599 * Emit any outstanding flushes - execbuf can fail to emit the flush
600 * after having emitted the batchbuffer command. Hence we need to fix
601 * things up similar to emitting the lazy request. The difference here
602 * is that the flush _must_ happen before the next request, no matter
606 ret = engine->emit_flush(request, EMIT_FLUSH);
608 /* Not allowed to fail! */
609 WARN(ret, "engine->emit_flush() failed: %d!\n", ret);
612 /* Record the position of the start of the breadcrumb so that
613 * should we detect the updated seqno part-way through the
614 * GPU processing the request, we never over-estimate the
615 * position of the ring's HEAD.
617 request->postfix = ring->tail;
619 /* Not allowed to fail! */
620 ret = engine->emit_request(request);
621 WARN(ret, "(%s)->emit_request failed: %d!\n", engine->name, ret);
623 /* Sanity check that the reserved size was large enough. */
624 ret = ring->tail - request_start;
627 WARN_ONCE(ret > reserved_tail,
628 "Not enough space reserved (%d bytes) "
629 "for adding the request (%d bytes)\n",
632 /* Seal the request and mark it as pending execution. Note that
633 * we may inspect this state, without holding any locks, during
634 * hangcheck. Hence we apply the barrier to ensure that we do not
635 * see a more recent value in the hws than we are tracking.
638 prev = i915_gem_active_raw(&engine->last_request,
639 &request->i915->drm.struct_mutex);
641 i915_sw_fence_await_sw_fence(&request->submit, &prev->submit,
644 request->emitted_jiffies = jiffies;
645 request->previous_seqno = engine->last_pending_seqno;
646 engine->last_pending_seqno = request->fence.seqno;
647 i915_gem_active_set(&engine->last_request, request);
648 list_add_tail(&request->link, &engine->request_list);
649 list_add_tail(&request->ring_link, &ring->request_list);
651 i915_gem_mark_busy(engine);
654 i915_sw_fence_commit(&request->submit);
655 local_bh_enable(); /* Kick the execlists tasklet if just scheduled */
658 static void reset_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
662 spin_lock_irqsave(&q->lock, flags);
663 if (list_empty(&wait->task_list))
664 __add_wait_queue(q, wait);
665 spin_unlock_irqrestore(&q->lock, flags);
668 static unsigned long local_clock_us(unsigned int *cpu)
672 /* Cheaply and approximately convert from nanoseconds to microseconds.
673 * The result and subsequent calculations are also defined in the same
674 * approximate microseconds units. The principal source of timing
675 * error here is from the simple truncation.
677 * Note that local_clock() is only defined wrt to the current CPU;
678 * the comparisons are no longer valid if we switch CPUs. Instead of
679 * blocking preemption for the entire busywait, we can detect the CPU
680 * switch and use that as indicator of system load and a reason to
681 * stop busywaiting, see busywait_stop().
684 t = local_clock() >> 10;
690 static bool busywait_stop(unsigned long timeout, unsigned int cpu)
692 unsigned int this_cpu;
694 if (time_after(local_clock_us(&this_cpu), timeout))
697 return this_cpu != cpu;
700 bool __i915_spin_request(const struct drm_i915_gem_request *req,
701 int state, unsigned long timeout_us)
705 /* When waiting for high frequency requests, e.g. during synchronous
706 * rendering split between the CPU and GPU, the finite amount of time
707 * required to set up the irq and wait upon it limits the response
708 * rate. By busywaiting on the request completion for a short while we
709 * can service the high frequency waits as quick as possible. However,
710 * if it is a slow request, we want to sleep as quickly as possible.
711 * The tradeoff between waiting and sleeping is roughly the time it
712 * takes to sleep on a request, on the order of a microsecond.
715 timeout_us += local_clock_us(&cpu);
717 if (i915_gem_request_completed(req))
720 if (signal_pending_state(state, current))
723 if (busywait_stop(timeout_us, cpu))
726 cpu_relax_lowlatency();
727 } while (!need_resched());
733 * i915_wait_request - wait until execution of request has finished
735 * @flags: how to wait
736 * @timeout: in - how long to wait (NULL forever); out - how much time remaining
737 * @rps: client to charge for RPS boosting
739 * Note: It is of utmost importance that the passed in seqno and reset_counter
740 * values have been read by the caller in an smp safe manner. Where read-side
741 * locks are involved, it is sufficient to read the reset_counter before
742 * unlocking the lock that protects the seqno. For lockless tricks, the
743 * reset_counter _must_ be read before, and an appropriate smp_rmb must be
746 * Returns 0 if the request was found within the alloted time. Else returns the
747 * errno with remaining time filled in timeout argument.
749 int i915_wait_request(struct drm_i915_gem_request *req,
752 struct intel_rps_client *rps)
754 const int state = flags & I915_WAIT_INTERRUPTIBLE ?
755 TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
757 struct intel_wait wait;
758 unsigned long timeout_remain;
762 #if IS_ENABLED(CONFIG_LOCKDEP)
763 GEM_BUG_ON(!!lockdep_is_held(&req->i915->drm.struct_mutex) !=
764 !!(flags & I915_WAIT_LOCKED));
767 if (i915_gem_request_completed(req))
770 timeout_remain = MAX_SCHEDULE_TIMEOUT;
772 if (WARN_ON(*timeout < 0))
778 /* Record current time in case interrupted, or wedged */
779 timeout_remain = nsecs_to_jiffies_timeout(*timeout);
780 *timeout += ktime_get_raw_ns();
783 trace_i915_gem_request_wait_begin(req);
785 /* This client is about to stall waiting for the GPU. In many cases
786 * this is undesirable and limits the throughput of the system, as
787 * many clients cannot continue processing user input/output whilst
788 * blocked. RPS autotuning may take tens of milliseconds to respond
789 * to the GPU load and thus incurs additional latency for the client.
790 * We can circumvent that by promoting the GPU frequency to maximum
791 * before we wait. This makes the GPU throttle up much more quickly
792 * (good for benchmarks and user experience, e.g. window animations),
793 * but at a cost of spending more power processing the workload
794 * (bad for battery). Not all clients even want their results
795 * immediately and for them we should just let the GPU select its own
796 * frequency to maximise efficiency. To prevent a single client from
797 * forcing the clocks too high for the whole system, we only allow
798 * each client to waitboost once in a busy period.
800 if (IS_RPS_CLIENT(rps) && INTEL_GEN(req->i915) >= 6)
801 gen6_rps_boost(req->i915, rps, req->emitted_jiffies);
803 /* Optimistic short spin before touching IRQs */
804 if (i915_spin_request(req, state, 5))
807 set_current_state(state);
808 if (flags & I915_WAIT_LOCKED)
809 add_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
811 intel_wait_init(&wait, req->fence.seqno);
812 if (intel_engine_add_wait(req->engine, &wait))
813 /* In order to check that we haven't missed the interrupt
814 * as we enabled it, we need to kick ourselves to do a
815 * coherent check on the seqno before we sleep.
820 if (signal_pending_state(state, current)) {
825 timeout_remain = io_schedule_timeout(timeout_remain);
826 if (timeout_remain == 0) {
831 if (intel_wait_complete(&wait))
834 set_current_state(state);
837 /* Carefully check if the request is complete, giving time
838 * for the seqno to be visible following the interrupt.
839 * We also have to check in case we are kicked by the GPU
840 * reset in order to drop the struct_mutex.
842 if (__i915_request_irq_complete(req))
845 /* If the GPU is hung, and we hold the lock, reset the GPU
846 * and then check for completion. On a full reset, the engine's
847 * HW seqno will be advanced passed us and we are complete.
848 * If we do a partial reset, we have to wait for the GPU to
849 * resume and update the breadcrumb.
851 * If we don't hold the mutex, we can just wait for the worker
852 * to come along and update the breadcrumb (either directly
853 * itself, or indirectly by recovering the GPU).
855 if (flags & I915_WAIT_LOCKED &&
856 i915_reset_in_progress(&req->i915->gpu_error)) {
857 __set_current_state(TASK_RUNNING);
858 i915_reset(req->i915);
859 reset_wait_queue(&req->i915->gpu_error.wait_queue,
864 /* Only spin if we know the GPU is processing this request */
865 if (i915_spin_request(req, state, 2))
869 intel_engine_remove_wait(req->engine, &wait);
870 if (flags & I915_WAIT_LOCKED)
871 remove_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
872 __set_current_state(TASK_RUNNING);
875 trace_i915_gem_request_wait_end(req);
878 *timeout -= ktime_get_raw_ns();
883 * Apparently ktime isn't accurate enough and occasionally has a
884 * bit of mismatch in the jiffies<->nsecs<->ktime loop. So patch
885 * things up to make the test happy. We allow up to 1 jiffy.
887 * This is a regrssion from the timespec->ktime conversion.
889 if (ret == -ETIME && *timeout < jiffies_to_usecs(1)*1000)
893 if (IS_RPS_USER(rps) &&
894 req->fence.seqno == req->engine->last_submitted_seqno) {
895 /* The GPU is now idle and this client has stalled.
896 * Since no other client has submitted a request in the
897 * meantime, assume that this client is the only one
898 * supplying work to the GPU but is unable to keep that
899 * work supplied because it is waiting. Since the GPU is
900 * then never kept fully busy, RPS autoclocking will
901 * keep the clocks relatively low, causing further delays.
902 * Compensate by giving the synchronous client credit for
903 * a waitboost next time.
905 spin_lock(&req->i915->rps.client_lock);
906 list_del_init(&rps->link);
907 spin_unlock(&req->i915->rps.client_lock);
913 static bool engine_retire_requests(struct intel_engine_cs *engine)
915 struct drm_i915_gem_request *request, *next;
917 list_for_each_entry_safe(request, next, &engine->request_list, link) {
918 if (!i915_gem_request_completed(request))
921 i915_gem_request_retire(request);
927 void i915_gem_retire_requests(struct drm_i915_private *dev_priv)
929 struct intel_engine_cs *engine;
932 lockdep_assert_held(&dev_priv->drm.struct_mutex);
934 if (dev_priv->gt.active_engines == 0)
937 GEM_BUG_ON(!dev_priv->gt.awake);
939 for_each_engine_masked(engine, dev_priv, dev_priv->gt.active_engines, tmp)
940 if (engine_retire_requests(engine))
941 dev_priv->gt.active_engines &= ~intel_engine_flag(engine);
943 if (dev_priv->gt.active_engines == 0)
944 queue_delayed_work(dev_priv->wq,
945 &dev_priv->gt.idle_work,
946 msecs_to_jiffies(100));