xref: /linux/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c (revision 52338415)
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 
38 #include <drm/drm_debugfs.h>
39 
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  *
133  * Emits a fence command on the requested ring (all asics).
134  * Returns 0 on success, -ENOMEM on failure.
135  */
136 int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f,
137 		      unsigned flags)
138 {
139 	struct amdgpu_device *adev = ring->adev;
140 	struct amdgpu_fence *fence;
141 	struct dma_fence __rcu **ptr;
142 	uint32_t seq;
143 	int r;
144 
145 	fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
146 	if (fence == NULL)
147 		return -ENOMEM;
148 
149 	seq = ++ring->fence_drv.sync_seq;
150 	fence->ring = ring;
151 	dma_fence_init(&fence->base, &amdgpu_fence_ops,
152 		       &ring->fence_drv.lock,
153 		       adev->fence_context + ring->idx,
154 		       seq);
155 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
156 			       seq, flags | AMDGPU_FENCE_FLAG_INT);
157 
158 	ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
159 	if (unlikely(rcu_dereference_protected(*ptr, 1))) {
160 		struct dma_fence *old;
161 
162 		rcu_read_lock();
163 		old = dma_fence_get_rcu_safe(ptr);
164 		rcu_read_unlock();
165 
166 		if (old) {
167 			r = dma_fence_wait(old, false);
168 			dma_fence_put(old);
169 			if (r)
170 				return r;
171 		}
172 	}
173 
174 	/* This function can't be called concurrently anyway, otherwise
175 	 * emitting the fence would mess up the hardware ring buffer.
176 	 */
177 	rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
178 
179 	*f = &fence->base;
180 
181 	return 0;
182 }
183 
184 /**
185  * amdgpu_fence_emit_polling - emit a fence on the requeste ring
186  *
187  * @ring: ring the fence is associated with
188  * @s: resulting sequence number
189  *
190  * Emits a fence command on the requested ring (all asics).
191  * Used For polling fence.
192  * Returns 0 on success, -ENOMEM on failure.
193  */
194 int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s)
195 {
196 	uint32_t seq;
197 
198 	if (!s)
199 		return -EINVAL;
200 
201 	seq = ++ring->fence_drv.sync_seq;
202 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
203 			       seq, 0);
204 
205 	*s = seq;
206 
207 	return 0;
208 }
209 
210 /**
211  * amdgpu_fence_schedule_fallback - schedule fallback check
212  *
213  * @ring: pointer to struct amdgpu_ring
214  *
215  * Start a timer as fallback to our interrupts.
216  */
217 static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
218 {
219 	mod_timer(&ring->fence_drv.fallback_timer,
220 		  jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
221 }
222 
223 /**
224  * amdgpu_fence_process - check for fence activity
225  *
226  * @ring: pointer to struct amdgpu_ring
227  *
228  * Checks the current fence value and calculates the last
229  * signalled fence value. Wakes the fence queue if the
230  * sequence number has increased.
231  *
232  * Returns true if fence was processed
233  */
234 bool amdgpu_fence_process(struct amdgpu_ring *ring)
235 {
236 	struct amdgpu_fence_driver *drv = &ring->fence_drv;
237 	uint32_t seq, last_seq;
238 	int r;
239 
240 	do {
241 		last_seq = atomic_read(&ring->fence_drv.last_seq);
242 		seq = amdgpu_fence_read(ring);
243 
244 	} while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
245 
246 	if (del_timer(&ring->fence_drv.fallback_timer) &&
247 	    seq != ring->fence_drv.sync_seq)
248 		amdgpu_fence_schedule_fallback(ring);
249 
250 	if (unlikely(seq == last_seq))
251 		return false;
252 
253 	last_seq &= drv->num_fences_mask;
254 	seq &= drv->num_fences_mask;
255 
256 	do {
257 		struct dma_fence *fence, **ptr;
258 
259 		++last_seq;
260 		last_seq &= drv->num_fences_mask;
261 		ptr = &drv->fences[last_seq];
262 
263 		/* There is always exactly one thread signaling this fence slot */
264 		fence = rcu_dereference_protected(*ptr, 1);
265 		RCU_INIT_POINTER(*ptr, NULL);
266 
267 		if (!fence)
268 			continue;
269 
270 		r = dma_fence_signal(fence);
271 		if (!r)
272 			DMA_FENCE_TRACE(fence, "signaled from irq context\n");
273 		else
274 			BUG();
275 
276 		dma_fence_put(fence);
277 	} while (last_seq != seq);
278 
279 	return true;
280 }
281 
282 /**
283  * amdgpu_fence_fallback - fallback for hardware interrupts
284  *
285  * @work: delayed work item
286  *
287  * Checks for fence activity.
288  */
289 static void amdgpu_fence_fallback(struct timer_list *t)
290 {
291 	struct amdgpu_ring *ring = from_timer(ring, t,
292 					      fence_drv.fallback_timer);
293 
294 	if (amdgpu_fence_process(ring))
295 		DRM_WARN("Fence fallback timer expired on ring %s\n", ring->name);
296 }
297 
298 /**
299  * amdgpu_fence_wait_empty - wait for all fences to signal
300  *
301  * @adev: amdgpu device pointer
302  * @ring: ring index the fence is associated with
303  *
304  * Wait for all fences on the requested ring to signal (all asics).
305  * Returns 0 if the fences have passed, error for all other cases.
306  */
307 int amdgpu_fence_wait_empty(struct amdgpu_ring *ring)
308 {
309 	uint64_t seq = READ_ONCE(ring->fence_drv.sync_seq);
310 	struct dma_fence *fence, **ptr;
311 	int r;
312 
313 	if (!seq)
314 		return 0;
315 
316 	ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
317 	rcu_read_lock();
318 	fence = rcu_dereference(*ptr);
319 	if (!fence || !dma_fence_get_rcu(fence)) {
320 		rcu_read_unlock();
321 		return 0;
322 	}
323 	rcu_read_unlock();
324 
325 	r = dma_fence_wait(fence, false);
326 	dma_fence_put(fence);
327 	return r;
328 }
329 
330 /**
331  * amdgpu_fence_wait_polling - busy wait for givn sequence number
332  *
333  * @ring: ring index the fence is associated with
334  * @wait_seq: sequence number to wait
335  * @timeout: the timeout for waiting in usecs
336  *
337  * Wait for all fences on the requested ring to signal (all asics).
338  * Returns left time if no timeout, 0 or minus if timeout.
339  */
340 signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring,
341 				      uint32_t wait_seq,
342 				      signed long timeout)
343 {
344 	uint32_t seq;
345 
346 	do {
347 		seq = amdgpu_fence_read(ring);
348 		udelay(5);
349 		timeout -= 5;
350 	} while ((int32_t)(wait_seq - seq) > 0 && timeout > 0);
351 
352 	return timeout > 0 ? timeout : 0;
353 }
354 /**
355  * amdgpu_fence_count_emitted - get the count of emitted fences
356  *
357  * @ring: ring the fence is associated with
358  *
359  * Get the number of fences emitted on the requested ring (all asics).
360  * Returns the number of emitted fences on the ring.  Used by the
361  * dynpm code to ring track activity.
362  */
363 unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring)
364 {
365 	uint64_t emitted;
366 
367 	/* We are not protected by ring lock when reading the last sequence
368 	 * but it's ok to report slightly wrong fence count here.
369 	 */
370 	amdgpu_fence_process(ring);
371 	emitted = 0x100000000ull;
372 	emitted -= atomic_read(&ring->fence_drv.last_seq);
373 	emitted += READ_ONCE(ring->fence_drv.sync_seq);
374 	return lower_32_bits(emitted);
375 }
376 
377 /**
378  * amdgpu_fence_driver_start_ring - make the fence driver
379  * ready for use on the requested ring.
380  *
381  * @ring: ring to start the fence driver on
382  * @irq_src: interrupt source to use for this ring
383  * @irq_type: interrupt type to use for this ring
384  *
385  * Make the fence driver ready for processing (all asics).
386  * Not all asics have all rings, so each asic will only
387  * start the fence driver on the rings it has.
388  * Returns 0 for success, errors for failure.
389  */
390 int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
391 				   struct amdgpu_irq_src *irq_src,
392 				   unsigned irq_type)
393 {
394 	struct amdgpu_device *adev = ring->adev;
395 	uint64_t index;
396 
397 	if (ring->funcs->type != AMDGPU_RING_TYPE_UVD) {
398 		ring->fence_drv.cpu_addr = &adev->wb.wb[ring->fence_offs];
399 		ring->fence_drv.gpu_addr = adev->wb.gpu_addr + (ring->fence_offs * 4);
400 	} else {
401 		/* put fence directly behind firmware */
402 		index = ALIGN(adev->uvd.fw->size, 8);
403 		ring->fence_drv.cpu_addr = adev->uvd.inst[ring->me].cpu_addr + index;
404 		ring->fence_drv.gpu_addr = adev->uvd.inst[ring->me].gpu_addr + index;
405 	}
406 	amdgpu_fence_write(ring, atomic_read(&ring->fence_drv.last_seq));
407 	amdgpu_irq_get(adev, irq_src, irq_type);
408 
409 	ring->fence_drv.irq_src = irq_src;
410 	ring->fence_drv.irq_type = irq_type;
411 	ring->fence_drv.initialized = true;
412 
413 	DRM_DEV_DEBUG(adev->dev, "fence driver on ring %s use gpu addr "
414 		      "0x%016llx, cpu addr 0x%p\n", ring->name,
415 		      ring->fence_drv.gpu_addr, ring->fence_drv.cpu_addr);
416 	return 0;
417 }
418 
419 /**
420  * amdgpu_fence_driver_init_ring - init the fence driver
421  * for the requested ring.
422  *
423  * @ring: ring to init the fence driver on
424  * @num_hw_submission: number of entries on the hardware queue
425  *
426  * Init the fence driver for the requested ring (all asics).
427  * Helper function for amdgpu_fence_driver_init().
428  */
429 int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
430 				  unsigned num_hw_submission)
431 {
432 	struct amdgpu_device *adev = ring->adev;
433 	long timeout;
434 	int r;
435 
436 	if (!adev)
437 		return -EINVAL;
438 
439 	/* Check that num_hw_submission is a power of two */
440 	if ((num_hw_submission & (num_hw_submission - 1)) != 0)
441 		return -EINVAL;
442 
443 	ring->fence_drv.cpu_addr = NULL;
444 	ring->fence_drv.gpu_addr = 0;
445 	ring->fence_drv.sync_seq = 0;
446 	atomic_set(&ring->fence_drv.last_seq, 0);
447 	ring->fence_drv.initialized = false;
448 
449 	timer_setup(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback, 0);
450 
451 	ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
452 	spin_lock_init(&ring->fence_drv.lock);
453 	ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
454 					 GFP_KERNEL);
455 	if (!ring->fence_drv.fences)
456 		return -ENOMEM;
457 
458 	/* No need to setup the GPU scheduler for KIQ ring */
459 	if (ring->funcs->type != AMDGPU_RING_TYPE_KIQ) {
460 		switch (ring->funcs->type) {
461 		case AMDGPU_RING_TYPE_GFX:
462 			timeout = adev->gfx_timeout;
463 			break;
464 		case AMDGPU_RING_TYPE_COMPUTE:
465 			/*
466 			 * For non-sriov case, no timeout enforce
467 			 * on compute ring by default. Unless user
468 			 * specifies a timeout for compute ring.
469 			 *
470 			 * For sriov case, always use the timeout
471 			 * as gfx ring
472 			 */
473 			if (!amdgpu_sriov_vf(ring->adev))
474 				timeout = adev->compute_timeout;
475 			else
476 				timeout = adev->gfx_timeout;
477 			break;
478 		case AMDGPU_RING_TYPE_SDMA:
479 			timeout = adev->sdma_timeout;
480 			break;
481 		default:
482 			timeout = adev->video_timeout;
483 			break;
484 		}
485 
486 		r = drm_sched_init(&ring->sched, &amdgpu_sched_ops,
487 				   num_hw_submission, amdgpu_job_hang_limit,
488 				   timeout, ring->name);
489 		if (r) {
490 			DRM_ERROR("Failed to create scheduler on ring %s.\n",
491 				  ring->name);
492 			return r;
493 		}
494 	}
495 
496 	return 0;
497 }
498 
499 /**
500  * amdgpu_fence_driver_init - init the fence driver
501  * for all possible rings.
502  *
503  * @adev: amdgpu device pointer
504  *
505  * Init the fence driver for all possible rings (all asics).
506  * Not all asics have all rings, so each asic will only
507  * start the fence driver on the rings it has using
508  * amdgpu_fence_driver_start_ring().
509  * Returns 0 for success.
510  */
511 int amdgpu_fence_driver_init(struct amdgpu_device *adev)
512 {
513 	if (amdgpu_debugfs_fence_init(adev))
514 		dev_err(adev->dev, "fence debugfs file creation failed\n");
515 
516 	return 0;
517 }
518 
519 /**
520  * amdgpu_fence_driver_fini - tear down the fence driver
521  * for all possible rings.
522  *
523  * @adev: amdgpu device pointer
524  *
525  * Tear down the fence driver for all possible rings (all asics).
526  */
527 void amdgpu_fence_driver_fini(struct amdgpu_device *adev)
528 {
529 	unsigned i, j;
530 	int 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 		r = amdgpu_fence_wait_empty(ring);
538 		if (r) {
539 			/* no need to trigger GPU reset as we are unloading */
540 			amdgpu_fence_driver_force_completion(ring);
541 		}
542 		amdgpu_irq_put(adev, ring->fence_drv.irq_src,
543 			       ring->fence_drv.irq_type);
544 		drm_sched_fini(&ring->sched);
545 		del_timer_sync(&ring->fence_drv.fallback_timer);
546 		for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
547 			dma_fence_put(ring->fence_drv.fences[j]);
548 		kfree(ring->fence_drv.fences);
549 		ring->fence_drv.fences = NULL;
550 		ring->fence_drv.initialized = false;
551 	}
552 }
553 
554 /**
555  * amdgpu_fence_driver_suspend - suspend the fence driver
556  * for all possible rings.
557  *
558  * @adev: amdgpu device pointer
559  *
560  * Suspend the fence driver for all possible rings (all asics).
561  */
562 void amdgpu_fence_driver_suspend(struct amdgpu_device *adev)
563 {
564 	int i, r;
565 
566 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
567 		struct amdgpu_ring *ring = adev->rings[i];
568 		if (!ring || !ring->fence_drv.initialized)
569 			continue;
570 
571 		/* wait for gpu to finish processing current batch */
572 		r = amdgpu_fence_wait_empty(ring);
573 		if (r) {
574 			/* delay GPU reset to resume */
575 			amdgpu_fence_driver_force_completion(ring);
576 		}
577 
578 		/* disable the interrupt */
579 		amdgpu_irq_put(adev, ring->fence_drv.irq_src,
580 			       ring->fence_drv.irq_type);
581 	}
582 }
583 
584 /**
585  * amdgpu_fence_driver_resume - resume the fence driver
586  * for all possible rings.
587  *
588  * @adev: amdgpu device pointer
589  *
590  * Resume the fence driver for all possible rings (all asics).
591  * Not all asics have all rings, so each asic will only
592  * start the fence driver on the rings it has using
593  * amdgpu_fence_driver_start_ring().
594  * Returns 0 for success.
595  */
596 void amdgpu_fence_driver_resume(struct amdgpu_device *adev)
597 {
598 	int i;
599 
600 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
601 		struct amdgpu_ring *ring = adev->rings[i];
602 		if (!ring || !ring->fence_drv.initialized)
603 			continue;
604 
605 		/* enable the interrupt */
606 		amdgpu_irq_get(adev, ring->fence_drv.irq_src,
607 			       ring->fence_drv.irq_type);
608 	}
609 }
610 
611 /**
612  * amdgpu_fence_driver_force_completion - force signal latest fence of ring
613  *
614  * @ring: fence of the ring to signal
615  *
616  */
617 void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring)
618 {
619 	amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
620 	amdgpu_fence_process(ring);
621 }
622 
623 /*
624  * Common fence implementation
625  */
626 
627 static const char *amdgpu_fence_get_driver_name(struct dma_fence *fence)
628 {
629 	return "amdgpu";
630 }
631 
632 static const char *amdgpu_fence_get_timeline_name(struct dma_fence *f)
633 {
634 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
635 	return (const char *)fence->ring->name;
636 }
637 
638 /**
639  * amdgpu_fence_enable_signaling - enable signalling on fence
640  * @fence: fence
641  *
642  * This function is called with fence_queue lock held, and adds a callback
643  * to fence_queue that checks if this fence is signaled, and if so it
644  * signals the fence and removes itself.
645  */
646 static bool amdgpu_fence_enable_signaling(struct dma_fence *f)
647 {
648 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
649 	struct amdgpu_ring *ring = fence->ring;
650 
651 	if (!timer_pending(&ring->fence_drv.fallback_timer))
652 		amdgpu_fence_schedule_fallback(ring);
653 
654 	DMA_FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
655 
656 	return true;
657 }
658 
659 /**
660  * amdgpu_fence_free - free up the fence memory
661  *
662  * @rcu: RCU callback head
663  *
664  * Free up the fence memory after the RCU grace period.
665  */
666 static void amdgpu_fence_free(struct rcu_head *rcu)
667 {
668 	struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
669 	struct amdgpu_fence *fence = to_amdgpu_fence(f);
670 	kmem_cache_free(amdgpu_fence_slab, fence);
671 }
672 
673 /**
674  * amdgpu_fence_release - callback that fence can be freed
675  *
676  * @fence: fence
677  *
678  * This function is called when the reference count becomes zero.
679  * It just RCU schedules freeing up the fence.
680  */
681 static void amdgpu_fence_release(struct dma_fence *f)
682 {
683 	call_rcu(&f->rcu, amdgpu_fence_free);
684 }
685 
686 static const struct dma_fence_ops amdgpu_fence_ops = {
687 	.get_driver_name = amdgpu_fence_get_driver_name,
688 	.get_timeline_name = amdgpu_fence_get_timeline_name,
689 	.enable_signaling = amdgpu_fence_enable_signaling,
690 	.release = amdgpu_fence_release,
691 };
692 
693 /*
694  * Fence debugfs
695  */
696 #if defined(CONFIG_DEBUG_FS)
697 static int amdgpu_debugfs_fence_info(struct seq_file *m, void *data)
698 {
699 	struct drm_info_node *node = (struct drm_info_node *)m->private;
700 	struct drm_device *dev = node->minor->dev;
701 	struct amdgpu_device *adev = dev->dev_private;
702 	int i;
703 
704 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
705 		struct amdgpu_ring *ring = adev->rings[i];
706 		if (!ring || !ring->fence_drv.initialized)
707 			continue;
708 
709 		amdgpu_fence_process(ring);
710 
711 		seq_printf(m, "--- ring %d (%s) ---\n", i, ring->name);
712 		seq_printf(m, "Last signaled fence          0x%08x\n",
713 			   atomic_read(&ring->fence_drv.last_seq));
714 		seq_printf(m, "Last emitted                 0x%08x\n",
715 			   ring->fence_drv.sync_seq);
716 
717 		if (ring->funcs->type == AMDGPU_RING_TYPE_GFX ||
718 		    ring->funcs->type == AMDGPU_RING_TYPE_SDMA) {
719 			seq_printf(m, "Last signaled trailing fence 0x%08x\n",
720 				   le32_to_cpu(*ring->trail_fence_cpu_addr));
721 			seq_printf(m, "Last emitted                 0x%08x\n",
722 				   ring->trail_seq);
723 		}
724 
725 		if (ring->funcs->type != AMDGPU_RING_TYPE_GFX)
726 			continue;
727 
728 		/* set in CP_VMID_PREEMPT and preemption occurred */
729 		seq_printf(m, "Last preempted               0x%08x\n",
730 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 2)));
731 		/* set in CP_VMID_RESET and reset occurred */
732 		seq_printf(m, "Last reset                   0x%08x\n",
733 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 4)));
734 		/* Both preemption and reset occurred */
735 		seq_printf(m, "Last both                    0x%08x\n",
736 			   le32_to_cpu(*(ring->fence_drv.cpu_addr + 6)));
737 	}
738 	return 0;
739 }
740 
741 /**
742  * amdgpu_debugfs_gpu_recover - manually trigger a gpu reset & recover
743  *
744  * Manually trigger a gpu reset at the next fence wait.
745  */
746 static int amdgpu_debugfs_gpu_recover(struct seq_file *m, void *data)
747 {
748 	struct drm_info_node *node = (struct drm_info_node *) m->private;
749 	struct drm_device *dev = node->minor->dev;
750 	struct amdgpu_device *adev = dev->dev_private;
751 
752 	seq_printf(m, "gpu recover\n");
753 	amdgpu_device_gpu_recover(adev, NULL);
754 
755 	return 0;
756 }
757 
758 static const struct drm_info_list amdgpu_debugfs_fence_list[] = {
759 	{"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
760 	{"amdgpu_gpu_recover", &amdgpu_debugfs_gpu_recover, 0, NULL}
761 };
762 
763 static const struct drm_info_list amdgpu_debugfs_fence_list_sriov[] = {
764 	{"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
765 };
766 #endif
767 
768 int amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
769 {
770 #if defined(CONFIG_DEBUG_FS)
771 	if (amdgpu_sriov_vf(adev))
772 		return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list_sriov, 1);
773 	return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list, 2);
774 #else
775 	return 0;
776 #endif
777 }
778 
779