aboutsummaryrefslogtreecommitdiff
path: root/linux-core/drm_fence.c
blob: 7c78e09f4947afa91bdf43478b6f35f705bd11f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
/**************************************************************************
 *
 * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */

#include "drmP.h"


/*
 * Convenience function to be called by fence::wait methods that
 * need polling.
 */

int drm_fence_wait_polling(struct drm_fence_object *fence, int lazy,
			   int interruptible, uint32_t mask, 
			   unsigned long end_jiffies)
{
	struct drm_device *dev = fence->dev;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence->fence_class];
	uint32_t count = 0;
	int ret;

	DECLARE_WAITQUEUE(entry, current);
	add_wait_queue(&fc->fence_queue, &entry);

	ret = 0;
	
	for (;;) {
		__set_current_state((interruptible) ? 
				    TASK_INTERRUPTIBLE :
				    TASK_UNINTERRUPTIBLE);
		if (drm_fence_object_signaled(fence, mask))
			break;
		if (time_after_eq(jiffies, end_jiffies)) {
			ret = -EBUSY;
			break;
		}
		if (lazy)
			schedule_timeout(1);
		else if ((++count & 0x0F) == 0){
			__set_current_state(TASK_RUNNING);
			schedule();
			__set_current_state((interruptible) ? 
					    TASK_INTERRUPTIBLE :
					    TASK_UNINTERRUPTIBLE);
		}			
		if (interruptible && signal_pending(current)) {
			ret = -EAGAIN;
			break;
		}
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&fc->fence_queue, &entry);
	return ret;
}
EXPORT_SYMBOL(drm_fence_wait_polling);

/*
 * Typically called by the IRQ handler.
 */

void drm_fence_handler(struct drm_device *dev, uint32_t fence_class,
		       uint32_t sequence, uint32_t type, uint32_t error)
{
	int wake = 0;
	uint32_t diff;
	uint32_t relevant_type;
	uint32_t new_type;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence_class];
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	struct list_head *head;
	struct drm_fence_object *fence, *next;
	int found = 0;

	if (list_empty(&fc->ring))
		return;

	list_for_each_entry(fence, &fc->ring, ring) {
		diff = (sequence - fence->sequence) & driver->sequence_mask;
		if (diff > driver->wrap_diff) {
			found = 1;
			break;
		}
	}

	fc->waiting_types &= ~type;
	head = (found) ? &fence->ring : &fc->ring;

	list_for_each_entry_safe_reverse(fence, next, head, ring) {
		if (&fence->ring == &fc->ring)
			break;

		if (error) {
			fence->error = error;
			fence->signaled_types = fence->type;
			list_del_init(&fence->ring);
			wake = 1;
			break;
		}

		if (type & DRM_FENCE_TYPE_EXE)
			type |= fence->native_types;

		relevant_type = type & fence->type;
		new_type = (fence->signaled_types | relevant_type) ^
			fence->signaled_types;

		if (new_type) {
			fence->signaled_types |= new_type;
			DRM_DEBUG("Fence 0x%08lx signaled 0x%08x\n",
				  fence->base.hash.key, fence->signaled_types);

			if (driver->needed_flush)
				fc->pending_flush |= driver->needed_flush(fence);

			if (new_type & fence->waiting_types)
				wake = 1;
		}

		fc->waiting_types |= fence->waiting_types & ~fence->signaled_types;

		if (!(fence->type & ~fence->signaled_types)) {
			DRM_DEBUG("Fence completely signaled 0x%08lx\n",
				  fence->base.hash.key);
			list_del_init(&fence->ring);
		}
	}

	/*
	 * Reinstate lost waiting types.
	 */

	if ((fc->waiting_types & type) != type) {
		head = head->prev;
		list_for_each_entry(fence, head, ring) {
			if (&fence->ring == &fc->ring)
				break;
			diff = (fc->highest_waiting_sequence - fence->sequence) &
				driver->sequence_mask;
			if (diff > driver->wrap_diff)
				break;
			
			fc->waiting_types |= fence->waiting_types & ~fence->signaled_types;
		}
	}

	if (wake) 
		wake_up_all(&fc->fence_queue);
}
EXPORT_SYMBOL(drm_fence_handler);

static void drm_fence_unring(struct drm_device *dev, struct list_head *ring)
{
	struct drm_fence_manager *fm = &dev->fm;
	unsigned long flags;

	write_lock_irqsave(&fm->lock, flags);
	list_del_init(ring);
	write_unlock_irqrestore(&fm->lock, flags);
}

void drm_fence_usage_deref_locked(struct drm_fence_object **fence)
{
	struct drm_fence_object *tmp_fence = *fence;
	struct drm_device *dev = tmp_fence->dev;
	struct drm_fence_manager *fm = &dev->fm;

	DRM_ASSERT_LOCKED(&dev->struct_mutex);
	*fence = NULL;
	if (atomic_dec_and_test(&tmp_fence->usage)) {
		drm_fence_unring(dev, &tmp_fence->ring);
		DRM_DEBUG("Destroyed a fence object 0x%08lx\n",
			  tmp_fence->base.hash.key);
		atomic_dec(&fm->count);
		BUG_ON(!list_empty(&tmp_fence->base.list));
		drm_ctl_free(tmp_fence, sizeof(*tmp_fence), DRM_MEM_FENCE);
	}
}
EXPORT_SYMBOL(drm_fence_usage_deref_locked);

void drm_fence_usage_deref_unlocked(struct drm_fence_object **fence)
{
	struct drm_fence_object *tmp_fence = *fence;
	struct drm_device *dev = tmp_fence->dev;
	struct drm_fence_manager *fm = &dev->fm;

	*fence = NULL;
	if (atomic_dec_and_test(&tmp_fence->usage)) {
		mutex_lock(&dev->struct_mutex);
		if (atomic_read(&tmp_fence->usage) == 0) {
			drm_fence_unring(dev, &tmp_fence->ring);
			atomic_dec(&fm->count);
			BUG_ON(!list_empty(&tmp_fence->base.list));
			drm_ctl_free(tmp_fence, sizeof(*tmp_fence), DRM_MEM_FENCE);
		}
		mutex_unlock(&dev->struct_mutex);
	}
}
EXPORT_SYMBOL(drm_fence_usage_deref_unlocked);

struct drm_fence_object
*drm_fence_reference_locked(struct drm_fence_object *src)
{
	DRM_ASSERT_LOCKED(&src->dev->struct_mutex);

	atomic_inc(&src->usage);
	return src;
}

void drm_fence_reference_unlocked(struct drm_fence_object **dst,
				  struct drm_fence_object *src)
{
	mutex_lock(&src->dev->struct_mutex);
	*dst = src;
	atomic_inc(&src->usage);
	mutex_unlock(&src->dev->struct_mutex);
}
EXPORT_SYMBOL(drm_fence_reference_unlocked);

static void drm_fence_object_destroy(struct drm_file *priv,
				     struct drm_user_object *base)
{
	struct drm_fence_object *fence =
	    drm_user_object_entry(base, struct drm_fence_object, base);

	drm_fence_usage_deref_locked(&fence);
}

int drm_fence_object_signaled(struct drm_fence_object *fence, uint32_t mask)
{
	unsigned long flags;
	int signaled;
	struct drm_device *dev = fence->dev;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	
	mask &= fence->type;
	read_lock_irqsave(&fm->lock, flags);
	signaled = (mask & fence->signaled_types) == mask;
	read_unlock_irqrestore(&fm->lock, flags);
	if (!signaled && driver->poll) {
		write_lock_irqsave(&fm->lock, flags);
		driver->poll(dev, fence->fence_class, mask);
		signaled = (mask & fence->signaled_types) == mask;
		write_unlock_irqrestore(&fm->lock, flags);
	}
	return signaled;
}
EXPORT_SYMBOL(drm_fence_object_signaled);


int drm_fence_object_flush(struct drm_fence_object *fence,
			   uint32_t type)
{
	struct drm_device *dev = fence->dev;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence->fence_class];
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	unsigned long irq_flags;
	uint32_t saved_pending_flush;
	uint32_t diff;
	int call_flush;

	if (type & ~fence->type) {
		DRM_ERROR("Flush trying to extend fence type, "
			  "0x%x, 0x%x\n", type, fence->type);
		return -EINVAL;
	}

	write_lock_irqsave(&fm->lock, irq_flags);
	fence->waiting_types |= type;
	fc->waiting_types |= fence->waiting_types;
	diff = (fence->sequence - fc->highest_waiting_sequence) & 
		driver->sequence_mask;

	if (diff < driver->wrap_diff)
		fc->highest_waiting_sequence = fence->sequence;

	/*
	 * fence->waiting_types has changed. Determine whether
	 * we need to initiate some kind of flush as a result of this.
	 */

	saved_pending_flush = fc->pending_flush;
	if (driver->needed_flush) 
		fc->pending_flush |= driver->needed_flush(fence);

	if (driver->poll)
		driver->poll(dev, fence->fence_class, fence->waiting_types);

	call_flush = fc->pending_flush;
	write_unlock_irqrestore(&fm->lock, irq_flags);

	if (call_flush && driver->flush)
		driver->flush(dev, fence->fence_class);

	return 0;
}
EXPORT_SYMBOL(drm_fence_object_flush);

/*
 * Make sure old fence objects are signaled before their fence sequences are
 * wrapped around and reused.
 */

void drm_fence_flush_old(struct drm_device *dev, uint32_t fence_class,
			 uint32_t sequence)
{
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence_class];
	struct drm_fence_object *fence;
	unsigned long irq_flags;
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	int call_flush;

	uint32_t diff;

	write_lock_irqsave(&fm->lock, irq_flags);

	list_for_each_entry_reverse(fence, &fc->ring, ring) {
		diff = (sequence - fence->sequence) & driver->sequence_mask;
		if (diff <= driver->flush_diff)
			break;
	
		fence->waiting_types = fence->type;
		fc->waiting_types |= fence->type;

		if (driver->needed_flush)
			fc->pending_flush |= driver->needed_flush(fence);
	}	
	
	if (driver->poll)
		driver->poll(dev, fence_class, fc->waiting_types);

	call_flush = fc->pending_flush;
	write_unlock_irqrestore(&fm->lock, irq_flags);

	if (call_flush && driver->flush)
		driver->flush(dev, fence->fence_class);

	/*
	 * FIXME: Shold we implement a wait here for really old fences?
	 */

}
EXPORT_SYMBOL(drm_fence_flush_old);

int drm_fence_object_wait(struct drm_fence_object *fence,
			  int lazy, int ignore_signals, uint32_t mask)
{
	struct drm_device *dev = fence->dev;
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence->fence_class];
	int ret = 0;
	unsigned long _end = 3 * DRM_HZ;

	if (mask & ~fence->type) {
		DRM_ERROR("Wait trying to extend fence type"
			  " 0x%08x 0x%08x\n", mask, fence->type);
		BUG();
		return -EINVAL;
	}

	if (driver->wait)
		return driver->wait(fence, lazy, !ignore_signals, mask);


	drm_fence_object_flush(fence, mask);
	if (driver->has_irq(dev, fence->fence_class, mask)) {
		if (!ignore_signals)
			ret = wait_event_interruptible_timeout
				(fc->fence_queue, 
				 drm_fence_object_signaled(fence, mask), 
				 3 * DRM_HZ);
		else 
			ret = wait_event_timeout
				(fc->fence_queue, 
				 drm_fence_object_signaled(fence, mask), 
				 3 * DRM_HZ);

		if (unlikely(ret == -ERESTARTSYS))
			return -EAGAIN;

		if (unlikely(ret == 0))
			return -EBUSY;

		return 0;
	}

	return drm_fence_wait_polling(fence, lazy, !ignore_signals, mask,
				      _end);
}
EXPORT_SYMBOL(drm_fence_object_wait);



int drm_fence_object_emit(struct drm_fence_object *fence, uint32_t fence_flags,
			  uint32_t fence_class, uint32_t type)
{
	struct drm_device *dev = fence->dev;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_driver *driver = dev->driver->fence_driver;
	struct drm_fence_class_manager *fc = &fm->fence_class[fence->fence_class];
	unsigned long flags;
	uint32_t sequence;
	uint32_t native_types;
	int ret;

	drm_fence_unring(dev, &fence->ring);
	ret = driver->emit(dev, fence_class, fence_flags, &sequence,
			   &native_types);
	if (ret)
		return ret;

	write_lock_irqsave(&fm->lock, flags);
	fence->fence_class = fence_class;
	fence->type = type;
	fence->waiting_types = 0;
	fence->signaled_types = 0;
	fence->error = 0;
	fence->sequence = sequence;
	fence->native_types = native_types;
	if (list_empty(&fc->ring))
		fc->highest_waiting_sequence = sequence - 1;
	list_add_tail(&fence->ring, &fc->ring);
	fc->latest_queued_sequence = sequence;
	write_unlock_irqrestore(&fm->lock, flags);
	return 0;
}
EXPORT_SYMBOL(drm_fence_object_emit);

static int drm_fence_object_init(struct drm_device *dev, uint32_t fence_class,
				 uint32_t type,
				 uint32_t fence_flags,
				 struct drm_fence_object *fence)
{
	int ret = 0;
	unsigned long flags;
	struct drm_fence_manager *fm = &dev->fm;

	mutex_lock(&dev->struct_mutex);
	atomic_set(&fence->usage, 1);
	mutex_unlock(&dev->struct_mutex);

	write_lock_irqsave(&fm->lock, flags);
	INIT_LIST_HEAD(&fence->ring);

	/*
	 *  Avoid hitting BUG() for kernel-only fence objects.
	 */

	INIT_LIST_HEAD(&fence->base.list);
	fence->fence_class = fence_class;
	fence->type = type;
	fence->signaled_types = 0;
	fence->waiting_types = 0;
	fence->sequence = 0;
	fence->error = 0;
	fence->dev = dev;
	write_unlock_irqrestore(&fm->lock, flags);
	if (fence_flags & DRM_FENCE_FLAG_EMIT) {
		ret = drm_fence_object_emit(fence, fence_flags,
					    fence->fence_class, type);
	}
	return ret;
}

int drm_fence_add_user_object(struct drm_file *priv,
			      struct drm_fence_object *fence, int shareable)
{
	struct drm_device *dev = priv->minor->dev;
	int ret;

	mutex_lock(&dev->struct_mutex);
	ret = drm_add_user_object(priv, &fence->base, shareable);
	if (ret)
		goto out;
	atomic_inc(&fence->usage);
	fence->base.type = drm_fence_type;
	fence->base.remove = &drm_fence_object_destroy;
	DRM_DEBUG("Fence 0x%08lx created\n", fence->base.hash.key);
out:
	mutex_unlock(&dev->struct_mutex);
	return ret;
}
EXPORT_SYMBOL(drm_fence_add_user_object);

int drm_fence_object_create(struct drm_device *dev, uint32_t fence_class,
			    uint32_t type, unsigned flags,
			    struct drm_fence_object **c_fence)
{
	struct drm_fence_object *fence;
	int ret;
	struct drm_fence_manager *fm = &dev->fm;

	fence = drm_ctl_calloc(1, sizeof(*fence), DRM_MEM_FENCE);
	if (!fence) {
		DRM_ERROR("Out of memory creating fence object\n");
		return -ENOMEM;
	}
	ret = drm_fence_object_init(dev, fence_class, type, flags, fence);
	if (ret) {
		drm_fence_usage_deref_unlocked(&fence);
		return ret;
	}
	*c_fence = fence;
	atomic_inc(&fm->count);

	return 0;
}
EXPORT_SYMBOL(drm_fence_object_create);

void drm_fence_manager_init(struct drm_device *dev)
{
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_class_manager *fence_class;
	struct drm_fence_driver *fed = dev->driver->fence_driver;
	int i;
	unsigned long flags;

	rwlock_init(&fm->lock);
	write_lock_irqsave(&fm->lock, flags);
	fm->initialized = 0;
	if (!fed)
	    goto out_unlock;

	fm->initialized = 1;
	fm->num_classes = fed->num_classes;
	BUG_ON(fm->num_classes > _DRM_FENCE_CLASSES);

	for (i = 0; i < fm->num_classes; ++i) {
	    fence_class = &fm->fence_class[i];

	    memset(fence_class, 0, sizeof(*fence_class));
	    INIT_LIST_HEAD(&fence_class->ring);
	    DRM_INIT_WAITQUEUE(&fence_class->fence_queue);
	}

	atomic_set(&fm->count, 0);
 out_unlock:
	write_unlock_irqrestore(&fm->lock, flags);
}

void drm_fence_fill_arg(struct drm_fence_object *fence,
			struct drm_fence_arg *arg)
{
	struct drm_device *dev = fence->dev;
	struct drm_fence_manager *fm = &dev->fm;
	unsigned long irq_flags;

	read_lock_irqsave(&fm->lock, irq_flags);
	arg->handle = fence->base.hash.key;
	arg->fence_class = fence->fence_class;
	arg->type = fence->type;
	arg->signaled = fence->signaled_types;
	arg->error = fence->error;
	arg->sequence = fence->sequence;
	read_unlock_irqrestore(&fm->lock, irq_flags);
}
EXPORT_SYMBOL(drm_fence_fill_arg);

void drm_fence_manager_takedown(struct drm_device *dev)
{
}

struct drm_fence_object *drm_lookup_fence_object(struct drm_file *priv,
						 uint32_t handle)
{
	struct drm_device *dev = priv->minor->dev;
	struct drm_user_object *uo;
	struct drm_fence_object *fence;

	mutex_lock(&dev->struct_mutex);
	uo = drm_lookup_user_object(priv, handle);
	if (!uo || (uo->type != drm_fence_type)) {
		mutex_unlock(&dev->struct_mutex);
		return NULL;
	}
	fence = drm_fence_reference_locked(drm_user_object_entry(uo, struct drm_fence_object, base));
	mutex_unlock(&dev->struct_mutex);
	return fence;
}

int drm_fence_create_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	if (arg->flags & DRM_FENCE_FLAG_EMIT)
		LOCK_TEST_WITH_RETURN(dev, file_priv);
	ret = drm_fence_object_create(dev, arg->fence_class,
				      arg->type, arg->flags, &fence);
	if (ret)
		return ret;
	ret = drm_fence_add_user_object(file_priv, fence,
					arg->flags &
					DRM_FENCE_FLAG_SHAREABLE);
	if (ret) {
		drm_fence_usage_deref_unlocked(&fence);
		return ret;
	}

	/*
	 * usage > 0. No need to lock dev->struct_mutex;
	 */

	arg->handle = fence->base.hash.key;

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}

int drm_fence_reference_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	struct drm_user_object *uo;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	ret = drm_user_object_ref(file_priv, arg->handle, drm_fence_type, &uo);
	if (ret)
		return ret;
	fence = drm_lookup_fence_object(file_priv, arg->handle);
	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}


int drm_fence_unreference_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	return drm_user_object_unref(file_priv, arg->handle, drm_fence_type);
}

int drm_fence_signaled_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	fence = drm_lookup_fence_object(file_priv, arg->handle);
	if (!fence)
		return -EINVAL;

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}

int drm_fence_flush_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	fence = drm_lookup_fence_object(file_priv, arg->handle);
	if (!fence)
		return -EINVAL;
	ret = drm_fence_object_flush(fence, arg->type);

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}


int drm_fence_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	fence = drm_lookup_fence_object(file_priv, arg->handle);
	if (!fence)
		return -EINVAL;
	ret = drm_fence_object_wait(fence,
				    arg->flags & DRM_FENCE_FLAG_WAIT_LAZY,
				    0, arg->type);

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}


int drm_fence_emit_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	LOCK_TEST_WITH_RETURN(dev, file_priv);
	fence = drm_lookup_fence_object(file_priv, arg->handle);
	if (!fence)
		return -EINVAL;
	ret = drm_fence_object_emit(fence, arg->flags, arg->fence_class,
				    arg->type);

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}

int drm_fence_buffers_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	int ret;
	struct drm_fence_manager *fm = &dev->fm;
	struct drm_fence_arg *arg = data;
	struct drm_fence_object *fence;
	ret = 0;

	if (!fm->initialized) {
		DRM_ERROR("The DRM driver does not support fencing.\n");
		return -EINVAL;
	}

	if (!dev->bm.initialized) {
		DRM_ERROR("Buffer object manager is not initialized\n");
		return -EINVAL;
	}
	LOCK_TEST_WITH_RETURN(dev, file_priv);
	ret = drm_fence_buffer_objects(dev, NULL, arg->flags,
				       NULL, &fence);
	if (ret)
		return ret;

	if (!(arg->flags & DRM_FENCE_FLAG_NO_USER)) {
		ret = drm_fence_add_user_object(file_priv, fence,
						arg->flags &
						DRM_FENCE_FLAG_SHAREABLE);
		if (ret)
			return ret;
	}

	arg->handle = fence->base.hash.key;

	drm_fence_fill_arg(fence, arg);
	drm_fence_usage_deref_unlocked(&fence);

	return ret;
}