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 
32 #include <linux/atomic.h>
33 #include <linux/firmware.h>
34 #include <linux/kref.h>
35 #include <linux/sched/signal.h>
36 #include <linux/seq_file.h>
37 #include <linux/slab.h>
38 #include <linux/wait.h>
39 
40 #include <drm/drm_debugfs.h>
41 #include <drm/drm_device.h>
42 #include <drm/drm_file.h>
43 
44 #include "radeon.h"
45 #include "radeon_reg.h"
46 #include "radeon_trace.h"
47 
48 /*
49  * Fences
50  * Fences mark an event in the GPUs pipeline and are used
51  * for GPU/CPU synchronization.  When the fence is written,
52  * it is expected that all buffers associated with that fence
53  * are no longer in use by the associated ring on the GPU and
54  * that the the relevant GPU caches have been flushed.  Whether
55  * we use a scratch register or memory location depends on the asic
56  * and whether writeback is enabled.
57  */
58 
59 /**
60  * radeon_fence_write - write a fence value
61  *
62  * @rdev: radeon_device pointer
63  * @seq: sequence number to write
64  * @ring: ring index the fence is associated with
65  *
66  * Writes a fence value to memory or a scratch register (all asics).
67  */
68 static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
69 {
70 	struct radeon_fence_driver *drv = &rdev->fence_drv[ring];
71 	if (likely(rdev->wb.enabled || !drv->scratch_reg)) {
72 		if (drv->cpu_addr) {
73 			*drv->cpu_addr = cpu_to_le32(seq);
74 		}
75 	} else {
76 		WREG32(drv->scratch_reg, seq);
77 	}
78 }
79 
80 /**
81  * radeon_fence_read - read a fence value
82  *
83  * @rdev: radeon_device pointer
84  * @ring: ring index the fence is associated with
85  *
86  * Reads a fence value from memory or a scratch register (all asics).
87  * Returns the value of the fence read from memory or register.
88  */
89 static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
90 {
91 	struct radeon_fence_driver *drv = &rdev->fence_drv[ring];
92 	u32 seq = 0;
93 
94 	if (likely(rdev->wb.enabled || !drv->scratch_reg)) {
95 		if (drv->cpu_addr) {
96 			seq = le32_to_cpu(*drv->cpu_addr);
97 		} else {
98 			seq = lower_32_bits(atomic64_read(&drv->last_seq));
99 		}
100 	} else {
101 		seq = RREG32(drv->scratch_reg);
102 	}
103 	return seq;
104 }
105 
106 /**
107  * radeon_fence_schedule_check - schedule lockup check
108  *
109  * @rdev: radeon_device pointer
110  * @ring: ring index we should work with
111  *
112  * Queues a delayed work item to check for lockups.
113  */
114 static void radeon_fence_schedule_check(struct radeon_device *rdev, int ring)
115 {
116 	/*
117 	 * Do not reset the timer here with mod_delayed_work,
118 	 * this can livelock in an interaction with TTM delayed destroy.
119 	 */
120 	queue_delayed_work(system_power_efficient_wq,
121 			   &rdev->fence_drv[ring].lockup_work,
122 			   RADEON_FENCE_JIFFIES_TIMEOUT);
123 }
124 
125 /**
126  * radeon_fence_emit - emit a fence on the requested ring
127  *
128  * @rdev: radeon_device pointer
129  * @fence: radeon fence object
130  * @ring: ring index the fence is associated with
131  *
132  * Emits a fence command on the requested ring (all asics).
133  * Returns 0 on success, -ENOMEM on failure.
134  */
135 int radeon_fence_emit(struct radeon_device *rdev,
136 		      struct radeon_fence **fence,
137 		      int ring)
138 {
139 	u64 seq;
140 
141 	/* we are protected by the ring emission mutex */
142 	*fence = kmalloc(sizeof(struct radeon_fence), GFP_KERNEL);
143 	if ((*fence) == NULL) {
144 		return -ENOMEM;
145 	}
146 	(*fence)->rdev = rdev;
147 	(*fence)->seq = seq = ++rdev->fence_drv[ring].sync_seq[ring];
148 	(*fence)->ring = ring;
149 	(*fence)->is_vm_update = false;
150 	dma_fence_init(&(*fence)->base, &radeon_fence_ops,
151 		       &rdev->fence_queue.lock,
152 		       rdev->fence_context + ring,
153 		       seq);
154 	radeon_fence_ring_emit(rdev, ring, *fence);
155 	trace_radeon_fence_emit(rdev->ddev, ring, (*fence)->seq);
156 	radeon_fence_schedule_check(rdev, ring);
157 	return 0;
158 }
159 
160 /*
161  * radeon_fence_check_signaled - callback from fence_queue
162  *
163  * this function is called with fence_queue lock held, which is also used
164  * for the fence locking itself, so unlocked variants are used for
165  * fence_signal, and remove_wait_queue.
166  */
167 static int radeon_fence_check_signaled(wait_queue_entry_t *wait, unsigned mode, int flags, void *key)
168 {
169 	struct radeon_fence *fence;
170 	u64 seq;
171 
172 	fence = container_of(wait, struct radeon_fence, fence_wake);
173 
174 	/*
175 	 * We cannot use radeon_fence_process here because we're already
176 	 * in the waitqueue, in a call from wake_up_all.
177 	 */
178 	seq = atomic64_read(&fence->rdev->fence_drv[fence->ring].last_seq);
179 	if (seq >= fence->seq) {
180 		int ret = dma_fence_signal_locked(&fence->base);
181 
182 		if (!ret)
183 			DMA_FENCE_TRACE(&fence->base, "signaled from irq context\n");
184 		else
185 			DMA_FENCE_TRACE(&fence->base, "was already signaled\n");
186 
187 		radeon_irq_kms_sw_irq_put(fence->rdev, fence->ring);
188 		__remove_wait_queue(&fence->rdev->fence_queue, &fence->fence_wake);
189 		dma_fence_put(&fence->base);
190 	} else
191 		DMA_FENCE_TRACE(&fence->base, "pending\n");
192 	return 0;
193 }
194 
195 /**
196  * radeon_fence_activity - check for fence activity
197  *
198  * @rdev: radeon_device pointer
199  * @ring: ring index the fence is associated with
200  *
201  * Checks the current fence value and calculates the last
202  * signalled fence value. Returns true if activity occured
203  * on the ring, and the fence_queue should be waken up.
204  */
205 static bool radeon_fence_activity(struct radeon_device *rdev, int ring)
206 {
207 	uint64_t seq, last_seq, last_emitted;
208 	unsigned count_loop = 0;
209 	bool wake = false;
210 
211 	/* Note there is a scenario here for an infinite loop but it's
212 	 * very unlikely to happen. For it to happen, the current polling
213 	 * process need to be interrupted by another process and another
214 	 * process needs to update the last_seq btw the atomic read and
215 	 * xchg of the current process.
216 	 *
217 	 * More over for this to go in infinite loop there need to be
218 	 * continuously new fence signaled ie radeon_fence_read needs
219 	 * to return a different value each time for both the currently
220 	 * polling process and the other process that xchg the last_seq
221 	 * btw atomic read and xchg of the current process. And the
222 	 * value the other process set as last seq must be higher than
223 	 * the seq value we just read. Which means that current process
224 	 * need to be interrupted after radeon_fence_read and before
225 	 * atomic xchg.
226 	 *
227 	 * To be even more safe we count the number of time we loop and
228 	 * we bail after 10 loop just accepting the fact that we might
229 	 * have temporarly set the last_seq not to the true real last
230 	 * seq but to an older one.
231 	 */
232 	last_seq = atomic64_read(&rdev->fence_drv[ring].last_seq);
233 	do {
234 		last_emitted = rdev->fence_drv[ring].sync_seq[ring];
235 		seq = radeon_fence_read(rdev, ring);
236 		seq |= last_seq & 0xffffffff00000000LL;
237 		if (seq < last_seq) {
238 			seq &= 0xffffffff;
239 			seq |= last_emitted & 0xffffffff00000000LL;
240 		}
241 
242 		if (seq <= last_seq || seq > last_emitted) {
243 			break;
244 		}
245 		/* If we loop over we don't want to return without
246 		 * checking if a fence is signaled as it means that the
247 		 * seq we just read is different from the previous on.
248 		 */
249 		wake = true;
250 		last_seq = seq;
251 		if ((count_loop++) > 10) {
252 			/* We looped over too many time leave with the
253 			 * fact that we might have set an older fence
254 			 * seq then the current real last seq as signaled
255 			 * by the hw.
256 			 */
257 			break;
258 		}
259 	} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
260 
261 	if (seq < last_emitted)
262 		radeon_fence_schedule_check(rdev, ring);
263 
264 	return wake;
265 }
266 
267 /**
268  * radeon_fence_check_lockup - check for hardware lockup
269  *
270  * @work: delayed work item
271  *
272  * Checks for fence activity and if there is none probe
273  * the hardware if a lockup occured.
274  */
275 static void radeon_fence_check_lockup(struct work_struct *work)
276 {
277 	struct radeon_fence_driver *fence_drv;
278 	struct radeon_device *rdev;
279 	int ring;
280 
281 	fence_drv = container_of(work, struct radeon_fence_driver,
282 				 lockup_work.work);
283 	rdev = fence_drv->rdev;
284 	ring = fence_drv - &rdev->fence_drv[0];
285 
286 	if (!down_read_trylock(&rdev->exclusive_lock)) {
287 		/* just reschedule the check if a reset is going on */
288 		radeon_fence_schedule_check(rdev, ring);
289 		return;
290 	}
291 
292 	if (fence_drv->delayed_irq && rdev->ddev->irq_enabled) {
293 		unsigned long irqflags;
294 
295 		fence_drv->delayed_irq = false;
296 		spin_lock_irqsave(&rdev->irq.lock, irqflags);
297 		radeon_irq_set(rdev);
298 		spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
299 	}
300 
301 	if (radeon_fence_activity(rdev, ring))
302 		wake_up_all(&rdev->fence_queue);
303 
304 	else if (radeon_ring_is_lockup(rdev, ring, &rdev->ring[ring])) {
305 
306 		/* good news we believe it's a lockup */
307 		dev_warn(rdev->dev, "GPU lockup (current fence id "
308 			 "0x%016llx last fence id 0x%016llx on ring %d)\n",
309 			 (uint64_t)atomic64_read(&fence_drv->last_seq),
310 			 fence_drv->sync_seq[ring], ring);
311 
312 		/* remember that we need an reset */
313 		rdev->needs_reset = true;
314 		wake_up_all(&rdev->fence_queue);
315 	}
316 	up_read(&rdev->exclusive_lock);
317 }
318 
319 /**
320  * radeon_fence_process - process a fence
321  *
322  * @rdev: radeon_device pointer
323  * @ring: ring index the fence is associated with
324  *
325  * Checks the current fence value and wakes the fence queue
326  * if the sequence number has increased (all asics).
327  */
328 void radeon_fence_process(struct radeon_device *rdev, int ring)
329 {
330 	if (radeon_fence_activity(rdev, ring))
331 		wake_up_all(&rdev->fence_queue);
332 }
333 
334 /**
335  * radeon_fence_seq_signaled - check if a fence sequence number has signaled
336  *
337  * @rdev: radeon device pointer
338  * @seq: sequence number
339  * @ring: ring index the fence is associated with
340  *
341  * Check if the last signaled fence sequnce number is >= the requested
342  * sequence number (all asics).
343  * Returns true if the fence has signaled (current fence value
344  * is >= requested value) or false if it has not (current fence
345  * value is < the requested value.  Helper function for
346  * radeon_fence_signaled().
347  */
348 static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
349 				      u64 seq, unsigned ring)
350 {
351 	if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
352 		return true;
353 	}
354 	/* poll new last sequence at least once */
355 	radeon_fence_process(rdev, ring);
356 	if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
357 		return true;
358 	}
359 	return false;
360 }
361 
362 static bool radeon_fence_is_signaled(struct dma_fence *f)
363 {
364 	struct radeon_fence *fence = to_radeon_fence(f);
365 	struct radeon_device *rdev = fence->rdev;
366 	unsigned ring = fence->ring;
367 	u64 seq = fence->seq;
368 
369 	if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
370 		return true;
371 	}
372 
373 	if (down_read_trylock(&rdev->exclusive_lock)) {
374 		radeon_fence_process(rdev, ring);
375 		up_read(&rdev->exclusive_lock);
376 
377 		if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
378 			return true;
379 		}
380 	}
381 	return false;
382 }
383 
384 /**
385  * radeon_fence_enable_signaling - enable signalling on fence
386  * @f: fence
387  *
388  * This function is called with fence_queue lock held, and adds a callback
389  * to fence_queue that checks if this fence is signaled, and if so it
390  * signals the fence and removes itself.
391  */
392 static bool radeon_fence_enable_signaling(struct dma_fence *f)
393 {
394 	struct radeon_fence *fence = to_radeon_fence(f);
395 	struct radeon_device *rdev = fence->rdev;
396 
397 	if (atomic64_read(&rdev->fence_drv[fence->ring].last_seq) >= fence->seq)
398 		return false;
399 
400 	if (down_read_trylock(&rdev->exclusive_lock)) {
401 		radeon_irq_kms_sw_irq_get(rdev, fence->ring);
402 
403 		if (radeon_fence_activity(rdev, fence->ring))
404 			wake_up_all_locked(&rdev->fence_queue);
405 
406 		/* did fence get signaled after we enabled the sw irq? */
407 		if (atomic64_read(&rdev->fence_drv[fence->ring].last_seq) >= fence->seq) {
408 			radeon_irq_kms_sw_irq_put(rdev, fence->ring);
409 			up_read(&rdev->exclusive_lock);
410 			return false;
411 		}
412 
413 		up_read(&rdev->exclusive_lock);
414 	} else {
415 		/* we're probably in a lockup, lets not fiddle too much */
416 		if (radeon_irq_kms_sw_irq_get_delayed(rdev, fence->ring))
417 			rdev->fence_drv[fence->ring].delayed_irq = true;
418 		radeon_fence_schedule_check(rdev, fence->ring);
419 	}
420 
421 	fence->fence_wake.flags = 0;
422 	fence->fence_wake.private = NULL;
423 	fence->fence_wake.func = radeon_fence_check_signaled;
424 	__add_wait_queue(&rdev->fence_queue, &fence->fence_wake);
425 	dma_fence_get(f);
426 
427 	DMA_FENCE_TRACE(&fence->base, "armed on ring %i!\n", fence->ring);
428 	return true;
429 }
430 
431 /**
432  * radeon_fence_signaled - check if a fence has signaled
433  *
434  * @fence: radeon fence object
435  *
436  * Check if the requested fence has signaled (all asics).
437  * Returns true if the fence has signaled or false if it has not.
438  */
439 bool radeon_fence_signaled(struct radeon_fence *fence)
440 {
441 	if (!fence)
442 		return true;
443 
444 	if (radeon_fence_seq_signaled(fence->rdev, fence->seq, fence->ring)) {
445 		int ret;
446 
447 		ret = dma_fence_signal(&fence->base);
448 		if (!ret)
449 			DMA_FENCE_TRACE(&fence->base, "signaled from radeon_fence_signaled\n");
450 		return true;
451 	}
452 	return false;
453 }
454 
455 /**
456  * radeon_fence_any_seq_signaled - check if any sequence number is signaled
457  *
458  * @rdev: radeon device pointer
459  * @seq: sequence numbers
460  *
461  * Check if the last signaled fence sequnce number is >= the requested
462  * sequence number (all asics).
463  * Returns true if any has signaled (current value is >= requested value)
464  * or false if it has not. Helper function for radeon_fence_wait_seq.
465  */
466 static bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
467 {
468 	unsigned i;
469 
470 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
471 		if (seq[i] && radeon_fence_seq_signaled(rdev, seq[i], i))
472 			return true;
473 	}
474 	return false;
475 }
476 
477 /**
478  * radeon_fence_wait_seq_timeout - wait for a specific sequence numbers
479  *
480  * @rdev: radeon device pointer
481  * @target_seq: sequence number(s) we want to wait for
482  * @intr: use interruptable sleep
483  * @timeout: maximum time to wait, or MAX_SCHEDULE_TIMEOUT for infinite wait
484  *
485  * Wait for the requested sequence number(s) to be written by any ring
486  * (all asics).  Sequnce number array is indexed by ring id.
487  * @intr selects whether to use interruptable (true) or non-interruptable
488  * (false) sleep when waiting for the sequence number.  Helper function
489  * for radeon_fence_wait_*().
490  * Returns remaining time if the sequence number has passed, 0 when
491  * the wait timeout, or an error for all other cases.
492  * -EDEADLK is returned when a GPU lockup has been detected.
493  */
494 static long radeon_fence_wait_seq_timeout(struct radeon_device *rdev,
495 					  u64 *target_seq, bool intr,
496 					  long timeout)
497 {
498 	long r;
499 	int i;
500 
501 	if (radeon_fence_any_seq_signaled(rdev, target_seq))
502 		return timeout;
503 
504 	/* enable IRQs and tracing */
505 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
506 		if (!target_seq[i])
507 			continue;
508 
509 		trace_radeon_fence_wait_begin(rdev->ddev, i, target_seq[i]);
510 		radeon_irq_kms_sw_irq_get(rdev, i);
511 	}
512 
513 	if (intr) {
514 		r = wait_event_interruptible_timeout(rdev->fence_queue, (
515 			radeon_fence_any_seq_signaled(rdev, target_seq)
516 			 || rdev->needs_reset), timeout);
517 	} else {
518 		r = wait_event_timeout(rdev->fence_queue, (
519 			radeon_fence_any_seq_signaled(rdev, target_seq)
520 			 || rdev->needs_reset), timeout);
521 	}
522 
523 	if (rdev->needs_reset)
524 		r = -EDEADLK;
525 
526 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
527 		if (!target_seq[i])
528 			continue;
529 
530 		radeon_irq_kms_sw_irq_put(rdev, i);
531 		trace_radeon_fence_wait_end(rdev->ddev, i, target_seq[i]);
532 	}
533 
534 	return r;
535 }
536 
537 /**
538  * radeon_fence_wait_timeout - wait for a fence to signal with timeout
539  *
540  * @fence: radeon fence object
541  * @intr: use interruptible sleep
542  *
543  * Wait for the requested fence to signal (all asics).
544  * @intr selects whether to use interruptable (true) or non-interruptable
545  * (false) sleep when waiting for the fence.
546  * @timeout: maximum time to wait, or MAX_SCHEDULE_TIMEOUT for infinite wait
547  * Returns remaining time if the sequence number has passed, 0 when
548  * the wait timeout, or an error for all other cases.
549  */
550 long radeon_fence_wait_timeout(struct radeon_fence *fence, bool intr, long timeout)
551 {
552 	uint64_t seq[RADEON_NUM_RINGS] = {};
553 	long r;
554 	int r_sig;
555 
556 	/*
557 	 * This function should not be called on !radeon fences.
558 	 * If this is the case, it would mean this function can
559 	 * also be called on radeon fences belonging to another card.
560 	 * exclusive_lock is not held in that case.
561 	 */
562 	if (WARN_ON_ONCE(!to_radeon_fence(&fence->base)))
563 		return dma_fence_wait(&fence->base, intr);
564 
565 	seq[fence->ring] = fence->seq;
566 	r = radeon_fence_wait_seq_timeout(fence->rdev, seq, intr, timeout);
567 	if (r <= 0) {
568 		return r;
569 	}
570 
571 	r_sig = dma_fence_signal(&fence->base);
572 	if (!r_sig)
573 		DMA_FENCE_TRACE(&fence->base, "signaled from fence_wait\n");
574 	return r;
575 }
576 
577 /**
578  * radeon_fence_wait - wait for a fence to signal
579  *
580  * @fence: radeon fence object
581  * @intr: use interruptible sleep
582  *
583  * Wait for the requested fence to signal (all asics).
584  * @intr selects whether to use interruptable (true) or non-interruptable
585  * (false) sleep when waiting for the fence.
586  * Returns 0 if the fence has passed, error for all other cases.
587  */
588 int radeon_fence_wait(struct radeon_fence *fence, bool intr)
589 {
590 	long r = radeon_fence_wait_timeout(fence, intr, MAX_SCHEDULE_TIMEOUT);
591 	if (r > 0) {
592 		return 0;
593 	} else {
594 		return r;
595 	}
596 }
597 
598 /**
599  * radeon_fence_wait_any - wait for a fence to signal on any ring
600  *
601  * @rdev: radeon device pointer
602  * @fences: radeon fence object(s)
603  * @intr: use interruptable sleep
604  *
605  * Wait for any requested fence to signal (all asics).  Fence
606  * array is indexed by ring id.  @intr selects whether to use
607  * interruptable (true) or non-interruptable (false) sleep when
608  * waiting for the fences. Used by the suballocator.
609  * Returns 0 if any fence has passed, error for all other cases.
610  */
611 int radeon_fence_wait_any(struct radeon_device *rdev,
612 			  struct radeon_fence **fences,
613 			  bool intr)
614 {
615 	uint64_t seq[RADEON_NUM_RINGS];
616 	unsigned i, num_rings = 0;
617 	long r;
618 
619 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
620 		seq[i] = 0;
621 
622 		if (!fences[i]) {
623 			continue;
624 		}
625 
626 		seq[i] = fences[i]->seq;
627 		++num_rings;
628 	}
629 
630 	/* nothing to wait for ? */
631 	if (num_rings == 0)
632 		return -ENOENT;
633 
634 	r = radeon_fence_wait_seq_timeout(rdev, seq, intr, MAX_SCHEDULE_TIMEOUT);
635 	if (r < 0) {
636 		return r;
637 	}
638 	return 0;
639 }
640 
641 /**
642  * radeon_fence_wait_next - wait for the next fence to signal
643  *
644  * @rdev: radeon device pointer
645  * @ring: ring index the fence is associated with
646  *
647  * Wait for the next fence on the requested ring to signal (all asics).
648  * Returns 0 if the next fence has passed, error for all other cases.
649  * Caller must hold ring lock.
650  */
651 int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
652 {
653 	uint64_t seq[RADEON_NUM_RINGS] = {};
654 	long r;
655 
656 	seq[ring] = atomic64_read(&rdev->fence_drv[ring].last_seq) + 1ULL;
657 	if (seq[ring] >= rdev->fence_drv[ring].sync_seq[ring]) {
658 		/* nothing to wait for, last_seq is
659 		   already the last emited fence */
660 		return -ENOENT;
661 	}
662 	r = radeon_fence_wait_seq_timeout(rdev, seq, false, MAX_SCHEDULE_TIMEOUT);
663 	if (r < 0)
664 		return r;
665 	return 0;
666 }
667 
668 /**
669  * radeon_fence_wait_empty - wait for all fences to signal
670  *
671  * @rdev: radeon device pointer
672  * @ring: ring index the fence is associated with
673  *
674  * Wait for all fences on the requested ring to signal (all asics).
675  * Returns 0 if the fences have passed, error for all other cases.
676  * Caller must hold ring lock.
677  */
678 int radeon_fence_wait_empty(struct radeon_device *rdev, int ring)
679 {
680 	uint64_t seq[RADEON_NUM_RINGS] = {};
681 	long r;
682 
683 	seq[ring] = rdev->fence_drv[ring].sync_seq[ring];
684 	if (!seq[ring])
685 		return 0;
686 
687 	r = radeon_fence_wait_seq_timeout(rdev, seq, false, MAX_SCHEDULE_TIMEOUT);
688 	if (r < 0) {
689 		if (r == -EDEADLK)
690 			return -EDEADLK;
691 
692 		dev_err(rdev->dev, "error waiting for ring[%d] to become idle (%ld)\n",
693 			ring, r);
694 	}
695 	return 0;
696 }
697 
698 /**
699  * radeon_fence_ref - take a ref on a fence
700  *
701  * @fence: radeon fence object
702  *
703  * Take a reference on a fence (all asics).
704  * Returns the fence.
705  */
706 struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
707 {
708 	dma_fence_get(&fence->base);
709 	return fence;
710 }
711 
712 /**
713  * radeon_fence_unref - remove a ref on a fence
714  *
715  * @fence: radeon fence object
716  *
717  * Remove a reference on a fence (all asics).
718  */
719 void radeon_fence_unref(struct radeon_fence **fence)
720 {
721 	struct radeon_fence *tmp = *fence;
722 
723 	*fence = NULL;
724 	if (tmp) {
725 		dma_fence_put(&tmp->base);
726 	}
727 }
728 
729 /**
730  * radeon_fence_count_emitted - get the count of emitted fences
731  *
732  * @rdev: radeon device pointer
733  * @ring: ring index the fence is associated with
734  *
735  * Get the number of fences emitted on the requested ring (all asics).
736  * Returns the number of emitted fences on the ring.  Used by the
737  * dynpm code to ring track activity.
738  */
739 unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
740 {
741 	uint64_t emitted;
742 
743 	/* We are not protected by ring lock when reading the last sequence
744 	 * but it's ok to report slightly wrong fence count here.
745 	 */
746 	radeon_fence_process(rdev, ring);
747 	emitted = rdev->fence_drv[ring].sync_seq[ring]
748 		- atomic64_read(&rdev->fence_drv[ring].last_seq);
749 	/* to avoid 32bits warp around */
750 	if (emitted > 0x10000000) {
751 		emitted = 0x10000000;
752 	}
753 	return (unsigned)emitted;
754 }
755 
756 /**
757  * radeon_fence_need_sync - do we need a semaphore
758  *
759  * @fence: radeon fence object
760  * @dst_ring: which ring to check against
761  *
762  * Check if the fence needs to be synced against another ring
763  * (all asics).  If so, we need to emit a semaphore.
764  * Returns true if we need to sync with another ring, false if
765  * not.
766  */
767 bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
768 {
769 	struct radeon_fence_driver *fdrv;
770 
771 	if (!fence) {
772 		return false;
773 	}
774 
775 	if (fence->ring == dst_ring) {
776 		return false;
777 	}
778 
779 	/* we are protected by the ring mutex */
780 	fdrv = &fence->rdev->fence_drv[dst_ring];
781 	if (fence->seq <= fdrv->sync_seq[fence->ring]) {
782 		return false;
783 	}
784 
785 	return true;
786 }
787 
788 /**
789  * radeon_fence_note_sync - record the sync point
790  *
791  * @fence: radeon fence object
792  * @dst_ring: which ring to check against
793  *
794  * Note the sequence number at which point the fence will
795  * be synced with the requested ring (all asics).
796  */
797 void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
798 {
799 	struct radeon_fence_driver *dst, *src;
800 	unsigned i;
801 
802 	if (!fence) {
803 		return;
804 	}
805 
806 	if (fence->ring == dst_ring) {
807 		return;
808 	}
809 
810 	/* we are protected by the ring mutex */
811 	src = &fence->rdev->fence_drv[fence->ring];
812 	dst = &fence->rdev->fence_drv[dst_ring];
813 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
814 		if (i == dst_ring) {
815 			continue;
816 		}
817 		dst->sync_seq[i] = max(dst->sync_seq[i], src->sync_seq[i]);
818 	}
819 }
820 
821 /**
822  * radeon_fence_driver_start_ring - make the fence driver
823  * ready for use on the requested ring.
824  *
825  * @rdev: radeon device pointer
826  * @ring: ring index to start the fence driver on
827  *
828  * Make the fence driver ready for processing (all asics).
829  * Not all asics have all rings, so each asic will only
830  * start the fence driver on the rings it has.
831  * Returns 0 for success, errors for failure.
832  */
833 int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
834 {
835 	uint64_t index;
836 	int r;
837 
838 	radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg);
839 	if (rdev->wb.use_event || !radeon_ring_supports_scratch_reg(rdev, &rdev->ring[ring])) {
840 		rdev->fence_drv[ring].scratch_reg = 0;
841 		if (ring != R600_RING_TYPE_UVD_INDEX) {
842 			index = R600_WB_EVENT_OFFSET + ring * 4;
843 			rdev->fence_drv[ring].cpu_addr = &rdev->wb.wb[index/4];
844 			rdev->fence_drv[ring].gpu_addr = rdev->wb.gpu_addr +
845 							 index;
846 
847 		} else {
848 			/* put fence directly behind firmware */
849 			index = ALIGN(rdev->uvd_fw->size, 8);
850 			rdev->fence_drv[ring].cpu_addr = rdev->uvd.cpu_addr + index;
851 			rdev->fence_drv[ring].gpu_addr = rdev->uvd.gpu_addr + index;
852 		}
853 
854 	} else {
855 		r = radeon_scratch_get(rdev, &rdev->fence_drv[ring].scratch_reg);
856 		if (r) {
857 			dev_err(rdev->dev, "fence failed to get scratch register\n");
858 			return r;
859 		}
860 		index = RADEON_WB_SCRATCH_OFFSET +
861 			rdev->fence_drv[ring].scratch_reg -
862 			rdev->scratch.reg_base;
863 		rdev->fence_drv[ring].cpu_addr = &rdev->wb.wb[index/4];
864 		rdev->fence_drv[ring].gpu_addr = rdev->wb.gpu_addr + index;
865 	}
866 	radeon_fence_write(rdev, atomic64_read(&rdev->fence_drv[ring].last_seq), ring);
867 	rdev->fence_drv[ring].initialized = true;
868 	dev_info(rdev->dev, "fence driver on ring %d use gpu addr 0x%016llx\n",
869 		 ring, rdev->fence_drv[ring].gpu_addr);
870 	return 0;
871 }
872 
873 /**
874  * radeon_fence_driver_init_ring - init the fence driver
875  * for the requested ring.
876  *
877  * @rdev: radeon device pointer
878  * @ring: ring index to start the fence driver on
879  *
880  * Init the fence driver for the requested ring (all asics).
881  * Helper function for radeon_fence_driver_init().
882  */
883 static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
884 {
885 	int i;
886 
887 	rdev->fence_drv[ring].scratch_reg = -1;
888 	rdev->fence_drv[ring].cpu_addr = NULL;
889 	rdev->fence_drv[ring].gpu_addr = 0;
890 	for (i = 0; i < RADEON_NUM_RINGS; ++i)
891 		rdev->fence_drv[ring].sync_seq[i] = 0;
892 	atomic64_set(&rdev->fence_drv[ring].last_seq, 0);
893 	rdev->fence_drv[ring].initialized = false;
894 	INIT_DELAYED_WORK(&rdev->fence_drv[ring].lockup_work,
895 			  radeon_fence_check_lockup);
896 	rdev->fence_drv[ring].rdev = rdev;
897 }
898 
899 /**
900  * radeon_fence_driver_init - init the fence driver
901  * for all possible rings.
902  *
903  * @rdev: radeon device pointer
904  *
905  * Init the fence driver for all possible rings (all asics).
906  * Not all asics have all rings, so each asic will only
907  * start the fence driver on the rings it has using
908  * radeon_fence_driver_start_ring().
909  * Returns 0 for success.
910  */
911 int radeon_fence_driver_init(struct radeon_device *rdev)
912 {
913 	int ring;
914 
915 	init_waitqueue_head(&rdev->fence_queue);
916 	for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
917 		radeon_fence_driver_init_ring(rdev, ring);
918 	}
919 	if (radeon_debugfs_fence_init(rdev)) {
920 		dev_err(rdev->dev, "fence debugfs file creation failed\n");
921 	}
922 	return 0;
923 }
924 
925 /**
926  * radeon_fence_driver_fini - tear down the fence driver
927  * for all possible rings.
928  *
929  * @rdev: radeon device pointer
930  *
931  * Tear down the fence driver for all possible rings (all asics).
932  */
933 void radeon_fence_driver_fini(struct radeon_device *rdev)
934 {
935 	int ring, r;
936 
937 	mutex_lock(&rdev->ring_lock);
938 	for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
939 		if (!rdev->fence_drv[ring].initialized)
940 			continue;
941 		r = radeon_fence_wait_empty(rdev, ring);
942 		if (r) {
943 			/* no need to trigger GPU reset as we are unloading */
944 			radeon_fence_driver_force_completion(rdev, ring);
945 		}
946 		cancel_delayed_work_sync(&rdev->fence_drv[ring].lockup_work);
947 		wake_up_all(&rdev->fence_queue);
948 		radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg);
949 		rdev->fence_drv[ring].initialized = false;
950 	}
951 	mutex_unlock(&rdev->ring_lock);
952 }
953 
954 /**
955  * radeon_fence_driver_force_completion - force all fence waiter to complete
956  *
957  * @rdev: radeon device pointer
958  * @ring: the ring to complete
959  *
960  * In case of GPU reset failure make sure no process keep waiting on fence
961  * that will never complete.
962  */
963 void radeon_fence_driver_force_completion(struct radeon_device *rdev, int ring)
964 {
965 	if (rdev->fence_drv[ring].initialized) {
966 		radeon_fence_write(rdev, rdev->fence_drv[ring].sync_seq[ring], ring);
967 		cancel_delayed_work_sync(&rdev->fence_drv[ring].lockup_work);
968 	}
969 }
970 
971 
972 /*
973  * Fence debugfs
974  */
975 #if defined(CONFIG_DEBUG_FS)
976 static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
977 {
978 	struct drm_info_node *node = (struct drm_info_node *)m->private;
979 	struct drm_device *dev = node->minor->dev;
980 	struct radeon_device *rdev = dev->dev_private;
981 	int i, j;
982 
983 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
984 		if (!rdev->fence_drv[i].initialized)
985 			continue;
986 
987 		radeon_fence_process(rdev, i);
988 
989 		seq_printf(m, "--- ring %d ---\n", i);
990 		seq_printf(m, "Last signaled fence 0x%016llx\n",
991 			   (unsigned long long)atomic64_read(&rdev->fence_drv[i].last_seq));
992 		seq_printf(m, "Last emitted        0x%016llx\n",
993 			   rdev->fence_drv[i].sync_seq[i]);
994 
995 		for (j = 0; j < RADEON_NUM_RINGS; ++j) {
996 			if (i != j && rdev->fence_drv[j].initialized)
997 				seq_printf(m, "Last sync to ring %d 0x%016llx\n",
998 					   j, rdev->fence_drv[i].sync_seq[j]);
999 		}
1000 	}
1001 	return 0;
1002 }
1003 
1004 /*
1005  * radeon_debugfs_gpu_reset - manually trigger a gpu reset
1006  *
1007  * Manually trigger a gpu reset at the next fence wait.
1008  */
1009 static int radeon_debugfs_gpu_reset(struct seq_file *m, void *data)
1010 {
1011 	struct drm_info_node *node = (struct drm_info_node *) m->private;
1012 	struct drm_device *dev = node->minor->dev;
1013 	struct radeon_device *rdev = dev->dev_private;
1014 
1015 	down_read(&rdev->exclusive_lock);
1016 	seq_printf(m, "%d\n", rdev->needs_reset);
1017 	rdev->needs_reset = true;
1018 	wake_up_all(&rdev->fence_queue);
1019 	up_read(&rdev->exclusive_lock);
1020 
1021 	return 0;
1022 }
1023 
1024 static struct drm_info_list radeon_debugfs_fence_list[] = {
1025 	{"radeon_fence_info", &radeon_debugfs_fence_info, 0, NULL},
1026 	{"radeon_gpu_reset", &radeon_debugfs_gpu_reset, 0, NULL}
1027 };
1028 #endif
1029 
1030 int radeon_debugfs_fence_init(struct radeon_device *rdev)
1031 {
1032 #if defined(CONFIG_DEBUG_FS)
1033 	return radeon_debugfs_add_files(rdev, radeon_debugfs_fence_list, 2);
1034 #else
1035 	return 0;
1036 #endif
1037 }
1038 
1039 static const char *radeon_fence_get_driver_name(struct dma_fence *fence)
1040 {
1041 	return "radeon";
1042 }
1043 
1044 static const char *radeon_fence_get_timeline_name(struct dma_fence *f)
1045 {
1046 	struct radeon_fence *fence = to_radeon_fence(f);
1047 	switch (fence->ring) {
1048 	case RADEON_RING_TYPE_GFX_INDEX: return "radeon.gfx";
1049 	case CAYMAN_RING_TYPE_CP1_INDEX: return "radeon.cp1";
1050 	case CAYMAN_RING_TYPE_CP2_INDEX: return "radeon.cp2";
1051 	case R600_RING_TYPE_DMA_INDEX: return "radeon.dma";
1052 	case CAYMAN_RING_TYPE_DMA1_INDEX: return "radeon.dma1";
1053 	case R600_RING_TYPE_UVD_INDEX: return "radeon.uvd";
1054 	case TN_RING_TYPE_VCE1_INDEX: return "radeon.vce1";
1055 	case TN_RING_TYPE_VCE2_INDEX: return "radeon.vce2";
1056 	default: WARN_ON_ONCE(1); return "radeon.unk";
1057 	}
1058 }
1059 
1060 static inline bool radeon_test_signaled(struct radeon_fence *fence)
1061 {
1062 	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags);
1063 }
1064 
1065 struct radeon_wait_cb {
1066 	struct dma_fence_cb base;
1067 	struct task_struct *task;
1068 };
1069 
1070 static void
1071 radeon_fence_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
1072 {
1073 	struct radeon_wait_cb *wait =
1074 		container_of(cb, struct radeon_wait_cb, base);
1075 
1076 	wake_up_process(wait->task);
1077 }
1078 
1079 static signed long radeon_fence_default_wait(struct dma_fence *f, bool intr,
1080 					     signed long t)
1081 {
1082 	struct radeon_fence *fence = to_radeon_fence(f);
1083 	struct radeon_device *rdev = fence->rdev;
1084 	struct radeon_wait_cb cb;
1085 
1086 	cb.task = current;
1087 
1088 	if (dma_fence_add_callback(f, &cb.base, radeon_fence_wait_cb))
1089 		return t;
1090 
1091 	while (t > 0) {
1092 		if (intr)
1093 			set_current_state(TASK_INTERRUPTIBLE);
1094 		else
1095 			set_current_state(TASK_UNINTERRUPTIBLE);
1096 
1097 		/*
1098 		 * radeon_test_signaled must be called after
1099 		 * set_current_state to prevent a race with wake_up_process
1100 		 */
1101 		if (radeon_test_signaled(fence))
1102 			break;
1103 
1104 		if (rdev->needs_reset) {
1105 			t = -EDEADLK;
1106 			break;
1107 		}
1108 
1109 		t = schedule_timeout(t);
1110 
1111 		if (t > 0 && intr && signal_pending(current))
1112 			t = -ERESTARTSYS;
1113 	}
1114 
1115 	__set_current_state(TASK_RUNNING);
1116 	dma_fence_remove_callback(f, &cb.base);
1117 
1118 	return t;
1119 }
1120 
1121 const struct dma_fence_ops radeon_fence_ops = {
1122 	.get_driver_name = radeon_fence_get_driver_name,
1123 	.get_timeline_name = radeon_fence_get_timeline_name,
1124 	.enable_signaling = radeon_fence_enable_signaling,
1125 	.signaled = radeon_fence_is_signaled,
1126 	.wait = radeon_fence_default_wait,
1127 	.release = NULL,
1128 };
1129