1 /*
2  * Copyright 2009 Jerome Glisse.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sub license, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
16  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
17  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
18  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
19  * USE OR OTHER DEALINGS IN THE SOFTWARE.
20  *
21  * The above copyright notice and this permission notice (including the
22  * next paragraph) shall be included in all copies or substantial portions
23  * of the Software.
24  *
25  */
26 /*
27  * Authors:
28  *    Jerome Glisse <glisse@freedesktop.org>
29  *    Dave Airlie
30  */
31 #include <linux/seq_file.h>
32 #include <linux/atomic.h>
33 #include <linux/wait.h>
34 #include <linux/kref.h>
35 #include <linux/slab.h>
36 #include <linux/firmware.h>
37 #include <linux/pm_runtime.h>
38 
39 #include <drm/drm_drv.h>
40 #include "amdgpu.h"
41 #include "amdgpu_trace.h"
42 
43 /*
44  * Fences
45  * Fences mark an event in the GPUs pipeline and are used
46  * for GPU/CPU synchronization.  When the fence is written,
47  * it is expected that all buffers associated with that fence
48  * are no longer in use by the associated ring on the GPU and
49  * that the the relevant GPU caches have been flushed.
50  */
51 
52 struct amdgpu_fence {
53 	struct dma_fence base;
54 
55 	/* RB, DMA, etc. */
56 	struct amdgpu_ring		*ring;
57 };
58 
59 static struct kmem_cache *amdgpu_fence_slab;
60 
61 int amdgpu_fence_slab_init(void)
62 {
63 	amdgpu_fence_slab = kmem_cache_create(
64 		"amdgpu_fence", sizeof(struct amdgpu_fence), 0,
65 		SLAB_HWCACHE_ALIGN, NULL);
66 	if (!amdgpu_fence_slab)
67 		return -ENOMEM;
68 	return 0;
69 }
70 
71 void amdgpu_fence_slab_fini(void)
72 {
73 	rcu_barrier();
74 	kmem_cache_destroy(amdgpu_fence_slab);
75 }
76 /*
77  * Cast helper
78  */
79 static const struct dma_fence_ops amdgpu_fence_ops;
80 static inline struct amdgpu_fence *to_amdgpu_fence(struct dma_fence *f)
81 {
82 	struct amdgpu_fence *__f = container_of(f, struct amdgpu_fence, base);
83 
84 	if (__f->base.ops == &amdgpu_fence_ops)
85 		return __f;
86 
87 	return NULL;
88 }
89 
90 /**
91  * amdgpu_fence_write - write a fence value
92  *
93  * @ring: ring the fence is associated with
94  * @seq: sequence number to write
95  *
96  * Writes a fence value to memory (all asics).
97  */
98 static void amdgpu_fence_write(struct amdgpu_ring *ring, u32 seq)
99 {
100 	struct amdgpu_fence_driver *drv = &ring->fence_drv;
101 
102 	if (drv->cpu_addr)
103 		*drv->cpu_addr = cpu_to_le32(seq);
104 }
105 
106 /**
107  * amdgpu_fence_read - read a fence value
108  *
109  * @ring: ring the fence is associated with
110  *
111  * Reads a fence value from memory (all asics).
112  * Returns the value of the fence read from memory.
113  */
114 static u32 amdgpu_fence_read(struct amdgpu_ring *ring)
115 {
116 	struct amdgpu_fence_driver *drv = &ring->fence_drv;
117 	u32 seq = 0;
118 
119 	if (drv->cpu_addr)
120 		seq = le32_to_cpu(*drv->cpu_addr);
121 	else
122 		seq = atomic_read(&drv->last_seq);
123 
124 	return seq;
125 }
126 
127 /**
128  * amdgpu_fence_emit - emit a fence on the requested ring
129  *
130  * @ring: ring the fence is associated with
131  * @f: resulting fence object
132  * @flags: flags to pass into the subordinate .emit_fence() call
133  *
134  * Emits a fence command on the requested ring (all asics).
135  * Returns 0 on success, -ENOMEM on failure.
136  */
137 int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
138 		      unsigned flags)
139 {
140 	struct amdgpu_device *adev = ring->adev;
141 	struct amdgpu_fence *fence;
142 	struct dma_fence __rcu **ptr;
143 	uint32_t seq;
144 	int r;
145 
146 	fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
147 	if (fence == NULL)
148 		return -ENOMEM;
149 
150 	seq = ++ring->fence_drv.sync_seq;
151 	fence->ring = ring;
152 	dma_fence_init(&fence->base, &amdgpu_fence_ops,
153 		       &ring->fence_drv.lock,
154 		       adev->fence_context + ring->idx,
155 		       seq);
156 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
157 			       seq, flags | AMDGPU_FENCE_FLAG_INT);
158 	pm_runtime_get_noresume(adev_to_drm(adev)->dev);
159 	ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
160 	if (unlikely(rcu_dereference_protected(*ptr, 1))) {
161 		struct dma_fence *old;
162 
163 		rcu_read_lock();
164 		old = dma_fence_get_rcu_safe(ptr);
165 		rcu_read_unlock();
166 
167 		if (old) {
168 			r = dma_fence_wait(old, false);
169 			dma_fence_put(old);
170 			if (r)
171 				return r;
172 		}
173 	}
174 
175 	/* This function can't be called concurrently anyway, otherwise
176 	 * emitting the fence would mess up the hardware ring buffer.
177 	 */
178 	rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
179 
180 	*f = &fence->base;
181 
182 	return 0;
183 }
184 
185 /**
186  * amdgpu_fence_emit_polling - emit a fence on the requeste ring
187  *
188  * @ring: ring the fence is associated with
189  * @s: resulting sequence number
190  * @timeout: the timeout for waiting in usecs
191  *
192  * Emits a fence command on the requested ring (all asics).
193  * Used For polling fence.
194  * Returns 0 on success, -ENOMEM on failure.
195  */
196 int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s,
197 			      uint32_t timeout)
198 {
199 	uint32_t seq;
200 	signed long r;
201 
202 	if (!s)
203 		return -EINVAL;
204 
205 	seq = ++ring->fence_drv.sync_seq;
206 	r = amdgpu_fence_wait_polling(ring,
207 				      seq - ring->fence_drv.num_fences_mask,
208 				      timeout);
209 	if (r < 1)
210 		return -ETIMEDOUT;
211 
212 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
213 			       seq, 0);
214 
215 	*s = seq;
216 
217 	return 0;
218 }
219 
220 /**
221  * amdgpu_fence_schedule_fallback - schedule fallback check
222  *
223  * @ring: pointer to struct amdgpu_ring
224  *
225  * Start a timer as fallback to our interrupts.
226  */
227 static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
228 {
229 	mod_timer(&ring->fence_drv.fallback_timer,
230 		  jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
231 }
232 
233 /**
234  * amdgpu_fence_process - check for fence activity
235  *
236  * @ring: pointer to struct amdgpu_ring
237  *
238  * Checks the current fence value and calculates the last
239  * signalled fence value. Wakes the fence queue if the
240  * sequence number has increased.
241  *
242  * Returns true if fence was processed
243  */
244 bool amdgpu_fence_process(struct amdgpu_ring *ring)
245 {
246 	struct amdgpu_fence_driver *drv = &ring->fence_drv;
247 	struct amdgpu_device *adev = ring->adev;
248 	uint32_t seq, last_seq;
249 	int r;
250 
251 	do {
252 		last_seq = atomic_read(&ring->fence_drv.last_seq);
253 		seq = amdgpu_fence_read(ring);
254 
255 	} while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
256 
257 	if (del_timer(&ring->fence_drv.fallback_timer) &&
258 	    seq != ring->fence_drv.sync_seq)
259 		amdgpu_fence_schedule_fallback(ring);
260 
261 	if (unlikely(seq == last_seq))
262 		return false;
263 
264 	last_seq &= drv->num_fences_mask;
265 	seq &= drv->num_fences_mask;
266 
267 	do {
268 		struct dma_fence *fence, **ptr;
269 
270 		++last_seq;
271 		last_seq &= drv->num_fences_mask;
272 		ptr = &drv->fences[last_seq];
273 
274 		/* There is always exactly one thread signaling this fence slot */
275 		fence = rcu_dereference_protected(*ptr, 1);
276 		RCU_INIT_POINTER(*ptr, NULL);
277 
278 		if (!fence)
279 			continue;
280 
281 		r = dma_fence_signal(fence);
282 		if (!r)
283 			DMA_FENCE_TRACE(fence, "signaled from irq context\n");
284 		else
285 			BUG();
286 
287 		dma_fence_put(fence);
288 		pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
289 		pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
290 	} while (last_seq != seq);
291 
292 	return true;
293 }
294 
295 /**
296  * amdgpu_fence_fallback - fallback for hardware interrupts
297  *
298  * @t: timer context used to obtain the pointer to ring structure
299  *
300  * Checks for fence activity.
301  */
302 static void amdgpu_fence_fallback(struct timer_list *t)
303 {
304 	struct amdgpu_ring *ring = from_timer(ring, t,
305 					      fence_drv.fallback_timer);
306 
307 	if (amdgpu_fence_process(ring))
308 		DRM_WARN("Fence fallback timer expired on ring %s\n", ring->name);
309 }
310 
311 /**
312  * amdgpu_fence_wait_empty - wait for all fences to signal
313  *
314  * @ring: ring index the fence is associated with
315  *
316  * Wait for all fences on the requested ring to signal (all asics).
317  * Returns 0 if the fences have passed, error for all other cases.
318  */
319 int amdgpu_fence_wait_empty(struct amdgpu_ring *ring)
320 {
321 	uint64_t seq = READ_ONCE(ring->fence_drv.sync_seq);
322 	struct dma_fence *fence, **ptr;
323 	int r;
324 
325 	if (!seq)
326 		return 0;
327 
328 	ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
329 	rcu_read_lock();
330 	fence = rcu_dereference(*ptr);
331 	if (!fence || !dma_fence_get_rcu(fence)) {
332 		rcu_read_unlock();
333 		return 0;
334 	}
335 	rcu_read_unlock();
336 
337 	r = dma_fence_wait(fence, false);
338 	dma_fence_put(fence);
339 	return r;
340 }
341 
342 /**
343  * amdgpu_fence_wait_polling - busy wait for givn sequence number
344  *
345  * @ring: ring index the fence is associated with
346  * @wait_seq: sequence number to wait
347  * @timeout: the timeout for waiting in usecs
348  *
349  * Wait for all fences on the requested ring to signal (all asics).
350  * Returns left time if no timeout, 0 or minus if timeout.
351  */
352 signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring,
353 				      uint32_t wait_seq,
354 				      signed long timeout)
355 {
356 	uint32_t seq;
357 
358 	do {
359 		seq = amdgpu_fence_read(ring);
360 		udelay(5);
361 		timeout -= 5;
362 	} while ((int32_t)(wait_seq - seq) > 0 && timeout > 0);
363 
364 	return timeout > 0 ? timeout : 0;
365 }
366 /**
367  * amdgpu_fence_count_emitted - get the count of emitted fences
368  *
369  * @ring: ring the fence is associated with
370  *
371  * Get the number of fences emitted on the requested ring (all asics).
372  * Returns the number of emitted fences on the ring.  Used by the
373  * dynpm code to ring track activity.
374  */
375 unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring)
376 {
377 	uint64_t emitted;
378 
379 	/* We are not protected by ring lock when reading the last sequence
380 	 * but it's ok to report slightly wrong fence count here.
381 	 */
382 	amdgpu_fence_process(ring);
383 	emitted = 0x100000000ull;
384 	emitted -= atomic_read(&ring->fence_drv.last_seq);
385 	emitted += READ_ONCE(ring->fence_drv.sync_seq);
386 	return lower_32_bits(emitted);
387 }
388 
389 /**
390  * amdgpu_fence_driver_start_ring - make the fence driver
391  * ready for use on the requested ring.
392  *
393  * @ring: ring to start the fence driver on
394  * @irq_src: interrupt source to use for this ring
395  * @irq_type: interrupt type to use for this ring
396  *
397  * Make the fence driver ready for processing (all asics).
398  * Not all asics have all rings, so each asic will only
399  * start the fence driver on the rings it has.
400  * Returns 0 for success, errors for failure.
401  */
402 int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
403 				   struct amdgpu_irq_src *irq_src,
404 				   unsigned irq_type)
405 {
406 	struct amdgpu_device *adev = ring->adev;
407 	uint64_t index;
408 
409 	if (ring->funcs->type != AMDGPU_RING_TYPE_UVD) {
410 		ring->fence_drv.cpu_addr = &adev->wb.wb[ring->fence_offs];
411 		ring->fence_drv.gpu_addr = adev->wb.gpu_addr + (ring->fence_offs * 4);
412 	} else {
413 		/* put fence directly behind firmware */
414 		index = ALIGN(adev->uvd.fw->size, 8);
415 		ring->fence_drv.cpu_addr = adev->uvd.inst[ring->me].cpu_addr + index;
416 		ring->fence_drv.gpu_addr = adev->uvd.inst[ring->me].gpu_addr + index;
417 	}
418 	amdgpu_fence_write(ring, atomic_read(&ring->fence_drv.last_seq));
419 
420 	if (irq_src)
421 		amdgpu_irq_get(adev, irq_src, irq_type);
422 
423 	ring->fence_drv.irq_src = irq_src;
424 	ring->fence_drv.irq_type = irq_type;
425 	ring->fence_drv.initialized = true;
426 
427 	DRM_DEV_DEBUG(adev->dev, "fence driver on ring %s use gpu addr 0x%016llx\n",
428 		      ring->name, ring->fence_drv.gpu_addr);
429 	return 0;
430 }
431 
432 /**
433  * amdgpu_fence_driver_init_ring - init the fence driver
434  * for the requested ring.
435  *
436  * @ring: ring to init the fence driver on
437  * @num_hw_submission: number of entries on the hardware queue
438  * @sched_score: optional score atomic shared with other schedulers
439  *
440  * Init the fence driver for the requested ring (all asics).
441  * Helper function for amdgpu_fence_driver_init().
442  */
443 int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
444 				  unsigned num_hw_submission,
445 				  atomic_t *sched_score)
446 {
447 	struct amdgpu_device *adev = ring->adev;
448 	long timeout;
449 	int r;
450 
451 	if (!adev)
452 		return -EINVAL;
453 
454 	if (!is_power_of_2(num_hw_submission))
455 		return -EINVAL;
456 
457 	ring->fence_drv.cpu_addr = NULL;
458 	ring->fence_drv.gpu_addr = 0;
459 	ring->fence_drv.sync_seq = 0;
460 	atomic_set(&ring->fence_drv.last_seq, 0);
461 	ring->fence_drv.initialized = false;
462 
463 	timer_setup(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback, 0);
464 
465 	ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
466 	spin_lock_init(&ring->fence_drv.lock);
467 	ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
468 					 GFP_KERNEL);
469 	if (!ring->fence_drv.fences)
470 		return -ENOMEM;
471 
472 	/* No need to setup the GPU scheduler for rings that don't need it */
473 	if (ring->no_scheduler)
474 		return 0;
475 
476 	switch (ring->funcs->type) {
477 	case AMDGPU_RING_TYPE_GFX:
478 		timeout = adev->gfx_timeout;
479 		break;
480 	case AMDGPU_RING_TYPE_COMPUTE:
481 		timeout = adev->compute_timeout;
482 		break;
483 	case AMDGPU_RING_TYPE_SDMA:
484 		timeout = adev->sdma_timeout;
485 		break;
486 	default:
487 		timeout = adev->video_timeout;
488 		break;
489 	}
490 
491 	r = drm_sched_init(&ring->sched, &amdgpu_sched_ops,
492 			   num_hw_submission, amdgpu_job_hang_limit,
493 			   timeout, sched_score, ring->name);
494 	if (r) {
495 		DRM_ERROR("Failed to create scheduler on ring %s.\n",
496 			  ring->name);
497 		return r;
498 	}
499 
500 	return 0;
501 }
502 
503 /**
504  * amdgpu_fence_driver_init - init the fence driver
505  * for all possible rings.
506  *
507  * @adev: amdgpu device pointer
508  *
509  * Init the fence driver for all possible rings (all asics).
510  * Not all asics have all rings, so each asic will only
511  * start the fence driver on the rings it has using
512  * amdgpu_fence_driver_start_ring().
513  * Returns 0 for success.
514  */
515 int amdgpu_fence_driver_init(struct amdgpu_device *adev)
516 {
517 	return 0;
518 }
519 
520 /**
521  * amdgpu_fence_driver_fini - tear down the fence driver
522  * for all possible rings.
523  *
524  * @adev: amdgpu device pointer
525  *
526  * Tear down the fence driver for all possible rings (all asics).
527  */
528 void amdgpu_fence_driver_fini_hw(struct amdgpu_device *adev)
529 {
530 	int i, r;
531 
532 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
533 		struct amdgpu_ring *ring = adev->rings[i];
534 
535 		if (!ring || !ring->fence_drv.initialized)
536 			continue;
537 		if (!ring->no_scheduler)
538 			drm_sched_fini(&ring->sched);
539 		/* You can't wait for HW to signal if it's gone */
540 		if (!drm_dev_is_unplugged(&adev->ddev))
541 			r = amdgpu_fence_wait_empty(ring);
542 		else
543 			r = -ENODEV;
544 		/* no need to trigger GPU reset as we are unloading */
545 		if (r)
546 			amdgpu_fence_driver_force_completion(ring);
547 
548 		if (ring->fence_drv.irq_src)
549 			amdgpu_irq_put(adev, ring->fence_drv.irq_src,
550 				       ring->fence_drv.irq_type);
551 
552 		del_timer_sync(&ring->fence_drv.fallback_timer);
553 	}
554 }
555 
556 void amdgpu_fence_driver_fini_sw(struct amdgpu_device *adev)
557 {
558 	unsigned int i, j;
559 
560 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
561 		struct amdgpu_ring *ring = adev->rings[i];
562 
563 		if (!ring || !ring->fence_drv.initialized)
564 			continue;
565 
566 		for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
567 			dma_fence_put(ring->fence_drv.fences[j]);
568 		kfree(ring->fence_drv.fences);
569 		ring->fence_drv.fences = NULL;
570 		ring->fence_drv.initialized = false;
571 	}
572 }
573 
574 /**
575  * amdgpu_fence_driver_suspend - suspend the fence driver
576  * for all possible rings.
577  *
578  * @adev: amdgpu device pointer
579  *
580  * Suspend the fence driver for all possible rings (all asics).
581  */
582 void amdgpu_fence_driver_suspend(struct amdgpu_device *adev)
583 {
584 	int i, r;
585 
586 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
587 		struct amdgpu_ring *ring = adev->rings[i];
588 		if (!ring || !ring->fence_drv.initialized)
589 			continue;
590 
591 		/* wait for gpu to finish processing current batch */
592 		r = amdgpu_fence_wait_empty(ring);
593 		if (r) {
594 			/* delay GPU reset to resume */
595 			amdgpu_fence_driver_force_completion(ring);
596 		}
597 
598 		/* disable the interrupt */
599 		if (ring->fence_drv.irq_src)
600 			amdgpu_irq_put(adev, ring->fence_drv.irq_src,
601 				       ring->fence_drv.irq_type);
602 	}
603 }
604 
605 /**
606  * amdgpu_fence_driver_resume - resume the fence driver
607  * for all possible rings.
608  *
609  * @adev: amdgpu device pointer
610  *
611  * Resume the fence driver for all possible rings (all asics).
612  * Not all asics have all rings, so each asic will only
613  * start the fence driver on the rings it has using
614  * amdgpu_fence_driver_start_ring().
615  * Returns 0 for success.
616  */
617 void amdgpu_fence_driver_resume(struct amdgpu_device *adev)
618 {
619 	int i;
620 
621 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
622 		struct amdgpu_ring *ring = adev->rings[i];
623 		if (!ring || !ring->fence_drv.initialized)
624 			continue;
625 
626 		/* enable the interrupt */
627 		if (ring->fence_drv.irq_src)
628 			amdgpu_irq_get(adev, ring->fence_drv.irq_src,
629 				       ring->fence_drv.irq_type);
630 	}
631 }
632 
633 /**
634  * amdgpu_fence_driver_force_completion - force signal latest fence of ring
635  *
636  * @ring: fence of the ring to signal
637  *
638  */
639 void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring)
640 {
641 	amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
642 	amdgpu_fence_process(ring);
643 }
644 
645 /*
646  * Common fence implementation
647  */
648 
649 static const char *amdgpu_fence_get_driver_name(struct dma_fence *fence)
650 {
651 	return "amdgpu";
652 }
653 
654 static const char *amdgpu_fence_get_timeline_name(struct dma_fence *f)
655 {
656 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
657 	return (const char *)fence->ring->name;
658 }
659 
660 /**
661  * amdgpu_fence_enable_signaling - enable signalling on fence
662  * @f: fence
663  *
664  * This function is called with fence_queue lock held, and adds a callback
665  * to fence_queue that checks if this fence is signaled, and if so it
666  * signals the fence and removes itself.
667  */
668 static bool amdgpu_fence_enable_signaling(struct dma_fence *f)
669 {
670 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
671 	struct amdgpu_ring *ring = fence->ring;
672 
673 	if (!timer_pending(&ring->fence_drv.fallback_timer))
674 		amdgpu_fence_schedule_fallback(ring);
675 
676 	DMA_FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
677 
678 	return true;
679 }
680 
681 /**
682  * amdgpu_fence_free - free up the fence memory
683  *
684  * @rcu: RCU callback head
685  *
686  * Free up the fence memory after the RCU grace period.
687  */
688 static void amdgpu_fence_free(struct rcu_head *rcu)
689 {
690 	struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
691 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
692 	kmem_cache_free(amdgpu_fence_slab, fence);
693 }
694 
695 /**
696  * amdgpu_fence_release - callback that fence can be freed
697  *
698  * @f: fence
699  *
700  * This function is called when the reference count becomes zero.
701  * It just RCU schedules freeing up the fence.
702  */
703 static void amdgpu_fence_release(struct dma_fence *f)
704 {
705 	call_rcu(&f->rcu, amdgpu_fence_free);
706 }
707 
708 static const struct dma_fence_ops amdgpu_fence_ops = {
709 	.get_driver_name = amdgpu_fence_get_driver_name,
710 	.get_timeline_name = amdgpu_fence_get_timeline_name,
711 	.enable_signaling = amdgpu_fence_enable_signaling,
712 	.release = amdgpu_fence_release,
713 };
714 
715 /*
716  * Fence debugfs
717  */
718 #if defined(CONFIG_DEBUG_FS)
719 static int amdgpu_debugfs_fence_info_show(struct seq_file *m, void *unused)
720 {
721 	struct amdgpu_device *adev = (struct amdgpu_device *)m->private;
722 	int i;
723 
724 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
725 		struct amdgpu_ring *ring = adev->rings[i];
726 		if (!ring || !ring->fence_drv.initialized)
727 			continue;
728 
729 		amdgpu_fence_process(ring);
730 
731 		seq_printf(m, "--- ring %d (%s) ---\n", i, ring->name);
732 		seq_printf(m, "Last signaled fence          0x%08x\n",
733 			   atomic_read(&ring->fence_drv.last_seq));
734 		seq_printf(m, "Last emitted                 0x%08x\n",
735 			   ring->fence_drv.sync_seq);
736 
737 		if (ring->funcs->type == AMDGPU_RING_TYPE_GFX ||
738 		    ring->funcs->type == AMDGPU_RING_TYPE_SDMA) {
739 			seq_printf(m, "Last signaled trailing fence 0x%08x\n",
740 				   le32_to_cpu(*ring->trail_fence_cpu_addr));
741 			seq_printf(m, "Last emitted                 0x%08x\n",
742 				   ring->trail_seq);
743 		}
744 
745 		if (ring->funcs->type != AMDGPU_RING_TYPE_GFX)
746 			continue;
747 
748 		/* set in CP_VMID_PREEMPT and preemption occurred */
749 		seq_printf(m, "Last preempted               0x%08x\n",
750 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 2)));
751 		/* set in CP_VMID_RESET and reset occurred */
752 		seq_printf(m, "Last reset                   0x%08x\n",
753 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 4)));
754 		/* Both preemption and reset occurred */
755 		seq_printf(m, "Last both                    0x%08x\n",
756 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 6)));
757 	}
758 	return 0;
759 }
760 
761 /*
762  * amdgpu_debugfs_gpu_recover - manually trigger a gpu reset & recover
763  *
764  * Manually trigger a gpu reset at the next fence wait.
765  */
766 static int gpu_recover_get(void *data, u64 *val)
767 {
768 	struct amdgpu_device *adev = (struct amdgpu_device *)data;
769 	struct drm_device *dev = adev_to_drm(adev);
770 	int r;
771 
772 	r = pm_runtime_get_sync(dev->dev);
773 	if (r < 0) {
774 		pm_runtime_put_autosuspend(dev->dev);
775 		return 0;
776 	}
777 
778 	*val = amdgpu_device_gpu_recover(adev, NULL);
779 
780 	pm_runtime_mark_last_busy(dev->dev);
781 	pm_runtime_put_autosuspend(dev->dev);
782 
783 	return 0;
784 }
785 
786 DEFINE_SHOW_ATTRIBUTE(amdgpu_debugfs_fence_info);
787 DEFINE_DEBUGFS_ATTRIBUTE(amdgpu_debugfs_gpu_recover_fops, gpu_recover_get, NULL,
788 			 "%lld\n");
789 
790 #endif
791 
792 void amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
793 {
794 #if defined(CONFIG_DEBUG_FS)
795 	struct drm_minor *minor = adev_to_drm(adev)->primary;
796 	struct dentry *root = minor->debugfs_root;
797 
798 	debugfs_create_file("amdgpu_fence_info", 0444, root, adev,
799 			    &amdgpu_debugfs_fence_info_fops);
800 
801 	if (!amdgpu_sriov_vf(adev))
802 		debugfs_create_file("amdgpu_gpu_recover", 0444, root, adev,
803 				    &amdgpu_debugfs_gpu_recover_fops);
804 #endif
805 }
806 
807