sync.c revision eeb2f571639feedcfce3f1718b0c3fd85d796812
1/*
2 * drivers/base/sync.c
3 *
4 * Copyright (C) 2012 Google, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 */
16
17#include <linux/debugfs.h>
18#include <linux/export.h>
19#include <linux/file.h>
20#include <linux/fs.h>
21#include <linux/kernel.h>
22#include <linux/poll.h>
23#include <linux/sched.h>
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/uaccess.h>
27#include <linux/anon_inodes.h>
28
29#include "sync.h"
30
31static void sync_fence_signal_pt(struct sync_pt *pt);
32static int _sync_pt_has_signaled(struct sync_pt *pt);
33static void sync_fence_free(struct kref *kref);
34static void sync_dump(void);
35
36static LIST_HEAD(sync_timeline_list_head);
37static DEFINE_SPINLOCK(sync_timeline_list_lock);
38
39static LIST_HEAD(sync_fence_list_head);
40static DEFINE_SPINLOCK(sync_fence_list_lock);
41
42struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
43					   int size, const char *name)
44{
45	struct sync_timeline *obj;
46	unsigned long flags;
47
48	if (size < sizeof(struct sync_timeline))
49		return NULL;
50
51	obj = kzalloc(size, GFP_KERNEL);
52	if (obj == NULL)
53		return NULL;
54
55	kref_init(&obj->kref);
56	obj->ops = ops;
57	strlcpy(obj->name, name, sizeof(obj->name));
58
59	INIT_LIST_HEAD(&obj->child_list_head);
60	spin_lock_init(&obj->child_list_lock);
61
62	INIT_LIST_HEAD(&obj->active_list_head);
63	spin_lock_init(&obj->active_list_lock);
64
65	spin_lock_irqsave(&sync_timeline_list_lock, flags);
66	list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
67	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
68
69	return obj;
70}
71EXPORT_SYMBOL(sync_timeline_create);
72
73static void sync_timeline_free(struct kref *kref)
74{
75	struct sync_timeline *obj =
76		container_of(kref, struct sync_timeline, kref);
77	unsigned long flags;
78
79	if (obj->ops->release_obj)
80		obj->ops->release_obj(obj);
81
82	spin_lock_irqsave(&sync_timeline_list_lock, flags);
83	list_del(&obj->sync_timeline_list);
84	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
85
86	kfree(obj);
87}
88
89void sync_timeline_destroy(struct sync_timeline *obj)
90{
91	obj->destroyed = true;
92
93	/*
94	 * If this is not the last reference, signal any children
95	 * that their parent is going away.
96	 */
97
98	if (!kref_put(&obj->kref, sync_timeline_free))
99		sync_timeline_signal(obj);
100}
101EXPORT_SYMBOL(sync_timeline_destroy);
102
103static void sync_timeline_add_pt(struct sync_timeline *obj, struct sync_pt *pt)
104{
105	unsigned long flags;
106
107	pt->parent = obj;
108
109	spin_lock_irqsave(&obj->child_list_lock, flags);
110	list_add_tail(&pt->child_list, &obj->child_list_head);
111	spin_unlock_irqrestore(&obj->child_list_lock, flags);
112}
113
114static void sync_timeline_remove_pt(struct sync_pt *pt)
115{
116	struct sync_timeline *obj = pt->parent;
117	unsigned long flags;
118
119	spin_lock_irqsave(&obj->active_list_lock, flags);
120	if (!list_empty(&pt->active_list))
121		list_del_init(&pt->active_list);
122	spin_unlock_irqrestore(&obj->active_list_lock, flags);
123
124	spin_lock_irqsave(&obj->child_list_lock, flags);
125	if (!list_empty(&pt->child_list)) {
126		list_del_init(&pt->child_list);
127	}
128	spin_unlock_irqrestore(&obj->child_list_lock, flags);
129}
130
131void sync_timeline_signal(struct sync_timeline *obj)
132{
133	unsigned long flags;
134	LIST_HEAD(signaled_pts);
135	struct list_head *pos, *n;
136
137	spin_lock_irqsave(&obj->active_list_lock, flags);
138
139	list_for_each_safe(pos, n, &obj->active_list_head) {
140		struct sync_pt *pt =
141			container_of(pos, struct sync_pt, active_list);
142
143		if (_sync_pt_has_signaled(pt)) {
144			list_del_init(pos);
145			list_add(&pt->signaled_list, &signaled_pts);
146			kref_get(&pt->fence->kref);
147		}
148	}
149
150	spin_unlock_irqrestore(&obj->active_list_lock, flags);
151
152	list_for_each_safe(pos, n, &signaled_pts) {
153		struct sync_pt *pt =
154			container_of(pos, struct sync_pt, signaled_list);
155
156		list_del_init(pos);
157		sync_fence_signal_pt(pt);
158		kref_put(&pt->fence->kref, sync_fence_free);
159	}
160}
161EXPORT_SYMBOL(sync_timeline_signal);
162
163struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size)
164{
165	struct sync_pt *pt;
166
167	if (size < sizeof(struct sync_pt))
168		return NULL;
169
170	pt = kzalloc(size, GFP_KERNEL);
171	if (pt == NULL)
172		return NULL;
173
174	INIT_LIST_HEAD(&pt->active_list);
175	kref_get(&parent->kref);
176	sync_timeline_add_pt(parent, pt);
177
178	return pt;
179}
180EXPORT_SYMBOL(sync_pt_create);
181
182void sync_pt_free(struct sync_pt *pt)
183{
184	if (pt->parent->ops->free_pt)
185		pt->parent->ops->free_pt(pt);
186
187	sync_timeline_remove_pt(pt);
188
189	kref_put(&pt->parent->kref, sync_timeline_free);
190
191	kfree(pt);
192}
193EXPORT_SYMBOL(sync_pt_free);
194
195/* call with pt->parent->active_list_lock held */
196static int _sync_pt_has_signaled(struct sync_pt *pt)
197{
198	int old_status = pt->status;
199
200	if (!pt->status)
201		pt->status = pt->parent->ops->has_signaled(pt);
202
203	if (!pt->status && pt->parent->destroyed)
204		pt->status = -ENOENT;
205
206	if (pt->status != old_status)
207		pt->timestamp = ktime_get();
208
209	return pt->status;
210}
211
212static struct sync_pt *sync_pt_dup(struct sync_pt *pt)
213{
214	return pt->parent->ops->dup(pt);
215}
216
217/* Adds a sync pt to the active queue.  Called when added to a fence */
218static void sync_pt_activate(struct sync_pt *pt)
219{
220	struct sync_timeline *obj = pt->parent;
221	unsigned long flags;
222	int err;
223
224	spin_lock_irqsave(&obj->active_list_lock, flags);
225
226	err = _sync_pt_has_signaled(pt);
227	if (err != 0)
228		goto out;
229
230	list_add_tail(&pt->active_list, &obj->active_list_head);
231
232out:
233	spin_unlock_irqrestore(&obj->active_list_lock, flags);
234}
235
236static int sync_fence_release(struct inode *inode, struct file *file);
237static unsigned int sync_fence_poll(struct file *file, poll_table *wait);
238static long sync_fence_ioctl(struct file *file, unsigned int cmd,
239			     unsigned long arg);
240
241
242static const struct file_operations sync_fence_fops = {
243	.release = sync_fence_release,
244	.poll = sync_fence_poll,
245	.unlocked_ioctl = sync_fence_ioctl,
246};
247
248static struct sync_fence *sync_fence_alloc(const char *name)
249{
250	struct sync_fence *fence;
251	unsigned long flags;
252
253	fence = kzalloc(sizeof(struct sync_fence), GFP_KERNEL);
254	if (fence == NULL)
255		return NULL;
256
257	fence->file = anon_inode_getfile("sync_fence", &sync_fence_fops,
258					 fence, 0);
259	if (fence->file == NULL)
260		goto err;
261
262	kref_init(&fence->kref);
263	strlcpy(fence->name, name, sizeof(fence->name));
264
265	INIT_LIST_HEAD(&fence->pt_list_head);
266	INIT_LIST_HEAD(&fence->waiter_list_head);
267	spin_lock_init(&fence->waiter_list_lock);
268
269	init_waitqueue_head(&fence->wq);
270
271	spin_lock_irqsave(&sync_fence_list_lock, flags);
272	list_add_tail(&fence->sync_fence_list, &sync_fence_list_head);
273	spin_unlock_irqrestore(&sync_fence_list_lock, flags);
274
275	return fence;
276
277err:
278	kfree(fence);
279	return NULL;
280}
281
282/* TODO: implement a create which takes more that one sync_pt */
283struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
284{
285	struct sync_fence *fence;
286
287	if (pt->fence)
288		return NULL;
289
290	fence = sync_fence_alloc(name);
291	if (fence == NULL)
292		return NULL;
293
294	pt->fence = fence;
295	list_add(&pt->pt_list, &fence->pt_list_head);
296	sync_pt_activate(pt);
297
298	/*
299	 * signal the fence in case pt was activated before
300	 * sync_pt_activate(pt) was called
301	 */
302	sync_fence_signal_pt(pt);
303
304	return fence;
305}
306EXPORT_SYMBOL(sync_fence_create);
307
308static int sync_fence_copy_pts(struct sync_fence *dst, struct sync_fence *src)
309{
310	struct list_head *pos;
311
312	list_for_each(pos, &src->pt_list_head) {
313		struct sync_pt *orig_pt =
314			container_of(pos, struct sync_pt, pt_list);
315		struct sync_pt *new_pt = sync_pt_dup(orig_pt);
316
317		if (new_pt == NULL)
318			return -ENOMEM;
319
320		new_pt->fence = dst;
321		list_add(&new_pt->pt_list, &dst->pt_list_head);
322		sync_pt_activate(new_pt);
323	}
324
325	return 0;
326}
327
328static int sync_fence_merge_pts(struct sync_fence *dst, struct sync_fence *src)
329{
330	struct list_head *src_pos, *dst_pos, *n;
331
332	list_for_each(src_pos, &src->pt_list_head) {
333		struct sync_pt *src_pt =
334			container_of(src_pos, struct sync_pt, pt_list);
335		bool collapsed = false;
336
337		list_for_each_safe(dst_pos, n, &dst->pt_list_head) {
338			struct sync_pt *dst_pt =
339				container_of(dst_pos, struct sync_pt, pt_list);
340			/* collapse two sync_pts on the same timeline
341			 * to a single sync_pt that will signal at
342			 * the later of the two
343			 */
344			if (dst_pt->parent == src_pt->parent) {
345				if (dst_pt->parent->ops->compare(dst_pt, src_pt)
346						 == -1) {
347					struct sync_pt *new_pt =
348						sync_pt_dup(src_pt);
349					if (new_pt == NULL)
350						return -ENOMEM;
351
352					new_pt->fence = dst;
353					list_replace(&dst_pt->pt_list,
354						     &new_pt->pt_list);
355					sync_pt_activate(new_pt);
356					sync_pt_free(dst_pt);
357				}
358				collapsed = true;
359				break;
360			}
361		}
362
363		if (!collapsed) {
364			struct sync_pt *new_pt = sync_pt_dup(src_pt);
365
366			if (new_pt == NULL)
367				return -ENOMEM;
368
369			new_pt->fence = dst;
370			list_add(&new_pt->pt_list, &dst->pt_list_head);
371			sync_pt_activate(new_pt);
372		}
373	}
374
375	return 0;
376}
377
378static void sync_fence_detach_pts(struct sync_fence *fence)
379{
380	struct list_head *pos, *n;
381
382	list_for_each_safe(pos, n, &fence->pt_list_head) {
383		struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
384		sync_timeline_remove_pt(pt);
385	}
386}
387
388static void sync_fence_free_pts(struct sync_fence *fence)
389{
390	struct list_head *pos, *n;
391
392	list_for_each_safe(pos, n, &fence->pt_list_head) {
393		struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
394		sync_pt_free(pt);
395	}
396}
397
398struct sync_fence *sync_fence_fdget(int fd)
399{
400	struct file *file = fget(fd);
401
402	if (file == NULL)
403		return NULL;
404
405	if (file->f_op != &sync_fence_fops)
406		goto err;
407
408	return file->private_data;
409
410err:
411	fput(file);
412	return NULL;
413}
414EXPORT_SYMBOL(sync_fence_fdget);
415
416void sync_fence_put(struct sync_fence *fence)
417{
418	fput(fence->file);
419}
420EXPORT_SYMBOL(sync_fence_put);
421
422void sync_fence_install(struct sync_fence *fence, int fd)
423{
424	fd_install(fd, fence->file);
425}
426EXPORT_SYMBOL(sync_fence_install);
427
428static int sync_fence_get_status(struct sync_fence *fence)
429{
430	struct list_head *pos;
431	int status = 1;
432
433	list_for_each(pos, &fence->pt_list_head) {
434		struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
435		int pt_status = pt->status;
436
437		if (pt_status < 0) {
438			status = pt_status;
439			break;
440		} else if (status == 1) {
441			status = pt_status;
442		}
443	}
444
445	return status;
446}
447
448struct sync_fence *sync_fence_merge(const char *name,
449				    struct sync_fence *a, struct sync_fence *b)
450{
451	struct sync_fence *fence;
452	int err;
453
454	fence = sync_fence_alloc(name);
455	if (fence == NULL)
456		return NULL;
457
458	err = sync_fence_copy_pts(fence, a);
459	if (err < 0)
460		goto err;
461
462	err = sync_fence_merge_pts(fence, b);
463	if (err < 0)
464		goto err;
465
466	/*
467	 * signal the fence in case one of it's pts were activated before
468	 * they were activated
469	 */
470	sync_fence_signal_pt(list_first_entry(&fence->pt_list_head,
471					      struct sync_pt,
472					      pt_list));
473
474	return fence;
475err:
476	sync_fence_free_pts(fence);
477	kfree(fence);
478	return NULL;
479}
480EXPORT_SYMBOL(sync_fence_merge);
481
482static void sync_fence_signal_pt(struct sync_pt *pt)
483{
484	LIST_HEAD(signaled_waiters);
485	struct sync_fence *fence = pt->fence;
486	struct list_head *pos;
487	struct list_head *n;
488	unsigned long flags;
489	int status;
490
491	status = sync_fence_get_status(fence);
492
493	spin_lock_irqsave(&fence->waiter_list_lock, flags);
494	/*
495	 * this should protect against two threads racing on the signaled
496	 * false -> true transition
497	 */
498	if (status && !fence->status) {
499		list_for_each_safe(pos, n, &fence->waiter_list_head)
500			list_move(pos, &signaled_waiters);
501
502		fence->status = status;
503	} else {
504		status = 0;
505	}
506	spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
507
508	if (status) {
509		list_for_each_safe(pos, n, &signaled_waiters) {
510			struct sync_fence_waiter *waiter =
511				container_of(pos, struct sync_fence_waiter,
512					     waiter_list);
513
514			list_del(pos);
515			waiter->callback(fence, waiter);
516		}
517		wake_up(&fence->wq);
518	}
519}
520
521int sync_fence_wait_async(struct sync_fence *fence,
522			  struct sync_fence_waiter *waiter)
523{
524	unsigned long flags;
525	int err = 0;
526
527	spin_lock_irqsave(&fence->waiter_list_lock, flags);
528
529	if (fence->status) {
530		err = fence->status;
531		goto out;
532	}
533
534	list_add_tail(&waiter->waiter_list, &fence->waiter_list_head);
535out:
536	spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
537
538	return err;
539}
540EXPORT_SYMBOL(sync_fence_wait_async);
541
542int sync_fence_cancel_async(struct sync_fence *fence,
543			     struct sync_fence_waiter *waiter)
544{
545	struct list_head *pos;
546	struct list_head *n;
547	unsigned long flags;
548	int ret = -ENOENT;
549
550	spin_lock_irqsave(&fence->waiter_list_lock, flags);
551	/*
552	 * Make sure waiter is still in waiter_list because it is possible for
553	 * the waiter to be removed from the list while the callback is still
554	 * pending.
555	 */
556	list_for_each_safe(pos, n, &fence->waiter_list_head) {
557		struct sync_fence_waiter *list_waiter =
558			container_of(pos, struct sync_fence_waiter,
559				     waiter_list);
560		if (list_waiter == waiter) {
561			list_del(pos);
562			ret = 0;
563			break;
564		}
565	}
566	spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
567	return ret;
568}
569EXPORT_SYMBOL(sync_fence_cancel_async);
570
571static bool sync_fence_check(struct sync_fence *fence)
572{
573	/*
574	 * Make sure that reads to fence->status are ordered with the
575	 * wait queue event triggering
576	 */
577	smp_rmb();
578	return fence->status != 0;
579}
580
581int sync_fence_wait(struct sync_fence *fence, long timeout)
582{
583	int err = 0;
584
585	if (timeout > 0) {
586		timeout = msecs_to_jiffies(timeout);
587		err = wait_event_interruptible_timeout(fence->wq,
588						       sync_fence_check(fence),
589						       timeout);
590	} else if (timeout < 0) {
591		err = wait_event_interruptible(fence->wq, fence->status != 0);
592	}
593
594	if (err < 0)
595		return err;
596
597	if (fence->status < 0) {
598		pr_info("fence error %d on [%p]\n", fence->status, fence);
599		sync_dump();
600		return fence->status;
601	}
602
603	if (fence->status == 0) {
604		pr_info("fence timeout on [%p] after %dms\n", fence,
605			jiffies_to_msecs(timeout));
606		sync_dump();
607		return -ETIME;
608	}
609
610	return 0;
611}
612EXPORT_SYMBOL(sync_fence_wait);
613
614static void sync_fence_free(struct kref *kref)
615{
616	struct sync_fence *fence = container_of(kref, struct sync_fence, kref);
617
618	sync_fence_free_pts(fence);
619
620	kfree(fence);
621}
622
623static int sync_fence_release(struct inode *inode, struct file *file)
624{
625	struct sync_fence *fence = file->private_data;
626	unsigned long flags;
627
628	/*
629	 * We need to remove all ways to access this fence before droping
630	 * our ref.
631	 *
632	 * start with its membership in the global fence list
633	 */
634	spin_lock_irqsave(&sync_fence_list_lock, flags);
635	list_del(&fence->sync_fence_list);
636	spin_unlock_irqrestore(&sync_fence_list_lock, flags);
637
638	/*
639	 * remove its pts from their parents so that sync_timeline_signal()
640	 * can't reference the fence.
641	 */
642	sync_fence_detach_pts(fence);
643
644	kref_put(&fence->kref, sync_fence_free);
645
646	return 0;
647}
648
649static unsigned int sync_fence_poll(struct file *file, poll_table *wait)
650{
651	struct sync_fence *fence = file->private_data;
652
653	poll_wait(file, &fence->wq, wait);
654
655	/*
656	 * Make sure that reads to fence->status are ordered with the
657	 * wait queue event triggering
658	 */
659	smp_rmb();
660
661	if (fence->status == 1)
662		return POLLIN;
663	else if (fence->status < 0)
664		return POLLERR;
665	else
666		return 0;
667}
668
669static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
670{
671	__s32 value;
672
673	if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
674		return -EFAULT;
675
676	return sync_fence_wait(fence, value);
677}
678
679static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
680{
681	int fd = get_unused_fd();
682	int err;
683	struct sync_fence *fence2, *fence3;
684	struct sync_merge_data data;
685
686	if (fd < 0)
687		return fd;
688
689	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
690		err = -EFAULT;
691		goto err_put_fd;
692	}
693
694	fence2 = sync_fence_fdget(data.fd2);
695	if (fence2 == NULL) {
696		err = -ENOENT;
697		goto err_put_fd;
698	}
699
700	data.name[sizeof(data.name) - 1] = '\0';
701	fence3 = sync_fence_merge(data.name, fence, fence2);
702	if (fence3 == NULL) {
703		err = -ENOMEM;
704		goto err_put_fence2;
705	}
706
707	data.fence = fd;
708	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
709		err = -EFAULT;
710		goto err_put_fence3;
711	}
712
713	sync_fence_install(fence3, fd);
714	sync_fence_put(fence2);
715	return 0;
716
717err_put_fence3:
718	sync_fence_put(fence3);
719
720err_put_fence2:
721	sync_fence_put(fence2);
722
723err_put_fd:
724	put_unused_fd(fd);
725	return err;
726}
727
728static int sync_fill_pt_info(struct sync_pt *pt, void *data, int size)
729{
730	struct sync_pt_info *info = data;
731	int ret;
732
733	if (size < sizeof(struct sync_pt_info))
734		return -ENOMEM;
735
736	info->len = sizeof(struct sync_pt_info);
737
738	if (pt->parent->ops->fill_driver_data) {
739		ret = pt->parent->ops->fill_driver_data(pt, info->driver_data,
740							size - sizeof(*info));
741		if (ret < 0)
742			return ret;
743
744		info->len += ret;
745	}
746
747	strlcpy(info->obj_name, pt->parent->name, sizeof(info->obj_name));
748	strlcpy(info->driver_name, pt->parent->ops->driver_name,
749		sizeof(info->driver_name));
750	info->status = pt->status;
751	info->timestamp_ns = ktime_to_ns(pt->timestamp);
752
753	return info->len;
754}
755
756static long sync_fence_ioctl_fence_info(struct sync_fence *fence,
757					unsigned long arg)
758{
759	struct sync_fence_info_data *data;
760	struct list_head *pos;
761	__u32 size;
762	__u32 len = 0;
763	int ret;
764
765	if (copy_from_user(&size, (void __user *)arg, sizeof(size)))
766		return -EFAULT;
767
768	if (size < sizeof(struct sync_fence_info_data))
769		return -EINVAL;
770
771	if (size > 4096)
772		size = 4096;
773
774	data = kzalloc(size, GFP_KERNEL);
775	if (data == NULL)
776		return -ENOMEM;
777
778	strlcpy(data->name, fence->name, sizeof(data->name));
779	data->status = fence->status;
780	len = sizeof(struct sync_fence_info_data);
781
782	list_for_each(pos, &fence->pt_list_head) {
783		struct sync_pt *pt =
784			container_of(pos, struct sync_pt, pt_list);
785
786		ret = sync_fill_pt_info(pt, (u8 *)data + len, size - len);
787
788		if (ret < 0)
789			goto out;
790
791		len += ret;
792	}
793
794	data->len = len;
795
796	if (copy_to_user((void __user *)arg, data, len))
797		ret = -EFAULT;
798	else
799		ret = 0;
800
801out:
802	kfree(data);
803
804	return ret;
805}
806
807static long sync_fence_ioctl(struct file *file, unsigned int cmd,
808			     unsigned long arg)
809{
810	struct sync_fence *fence = file->private_data;
811	switch (cmd) {
812	case SYNC_IOC_WAIT:
813		return sync_fence_ioctl_wait(fence, arg);
814
815	case SYNC_IOC_MERGE:
816		return sync_fence_ioctl_merge(fence, arg);
817
818	case SYNC_IOC_FENCE_INFO:
819		return sync_fence_ioctl_fence_info(fence, arg);
820
821	default:
822		return -ENOTTY;
823	}
824}
825
826#ifdef CONFIG_DEBUG_FS
827static const char *sync_status_str(int status)
828{
829	if (status > 0)
830		return "signaled";
831	else if (status == 0)
832		return "active";
833	else
834		return "error";
835}
836
837static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence)
838{
839	int status = pt->status;
840	seq_printf(s, "  %s%spt %s",
841		   fence ? pt->parent->name : "",
842		   fence ? "_" : "",
843		   sync_status_str(status));
844	if (pt->status) {
845		struct timeval tv = ktime_to_timeval(pt->timestamp);
846		seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec);
847	}
848
849	if (pt->parent->ops->print_pt) {
850		seq_printf(s, ": ");
851		pt->parent->ops->print_pt(s, pt);
852	}
853
854	seq_printf(s, "\n");
855}
856
857static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
858{
859	struct list_head *pos;
860	unsigned long flags;
861
862	seq_printf(s, "%s %s", obj->name, obj->ops->driver_name);
863
864	if (obj->ops->print_obj) {
865		seq_printf(s, ": ");
866		obj->ops->print_obj(s, obj);
867	}
868
869	seq_printf(s, "\n");
870
871	spin_lock_irqsave(&obj->child_list_lock, flags);
872	list_for_each(pos, &obj->child_list_head) {
873		struct sync_pt *pt =
874			container_of(pos, struct sync_pt, child_list);
875		sync_print_pt(s, pt, false);
876	}
877	spin_unlock_irqrestore(&obj->child_list_lock, flags);
878}
879
880static void sync_print_fence(struct seq_file *s, struct sync_fence *fence)
881{
882	struct list_head *pos;
883	unsigned long flags;
884
885	seq_printf(s, "[%p] %s: %s\n", fence, fence->name,
886		   sync_status_str(fence->status));
887
888	list_for_each(pos, &fence->pt_list_head) {
889		struct sync_pt *pt =
890			container_of(pos, struct sync_pt, pt_list);
891		sync_print_pt(s, pt, true);
892	}
893
894	spin_lock_irqsave(&fence->waiter_list_lock, flags);
895	list_for_each(pos, &fence->waiter_list_head) {
896		struct sync_fence_waiter *waiter =
897			container_of(pos, struct sync_fence_waiter,
898				     waiter_list);
899
900		seq_printf(s, "waiter %pF\n", waiter->callback);
901	}
902	spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
903}
904
905static int sync_debugfs_show(struct seq_file *s, void *unused)
906{
907	unsigned long flags;
908	struct list_head *pos;
909
910	seq_printf(s, "objs:\n--------------\n");
911
912	spin_lock_irqsave(&sync_timeline_list_lock, flags);
913	list_for_each(pos, &sync_timeline_list_head) {
914		struct sync_timeline *obj =
915			container_of(pos, struct sync_timeline,
916				     sync_timeline_list);
917
918		sync_print_obj(s, obj);
919		seq_printf(s, "\n");
920	}
921	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
922
923	seq_printf(s, "fences:\n--------------\n");
924
925	spin_lock_irqsave(&sync_fence_list_lock, flags);
926	list_for_each(pos, &sync_fence_list_head) {
927		struct sync_fence *fence =
928			container_of(pos, struct sync_fence, sync_fence_list);
929
930		sync_print_fence(s, fence);
931		seq_printf(s, "\n");
932	}
933	spin_unlock_irqrestore(&sync_fence_list_lock, flags);
934	return 0;
935}
936
937static int sync_debugfs_open(struct inode *inode, struct file *file)
938{
939	return single_open(file, sync_debugfs_show, inode->i_private);
940}
941
942static const struct file_operations sync_debugfs_fops = {
943	.open           = sync_debugfs_open,
944	.read           = seq_read,
945	.llseek         = seq_lseek,
946	.release        = single_release,
947};
948
949static __init int sync_debugfs_init(void)
950{
951	debugfs_create_file("sync", S_IRUGO, NULL, NULL, &sync_debugfs_fops);
952	return 0;
953}
954late_initcall(sync_debugfs_init);
955
956#define DUMP_CHUNK 256
957static char sync_dump_buf[64 * 1024];
958void sync_dump(void)
959{
960	struct seq_file s = {
961		.buf = sync_dump_buf,
962		.size = sizeof(sync_dump_buf) - 1,
963	};
964	int i;
965
966	sync_debugfs_show(&s, NULL);
967
968	for (i = 0; i < s.count; i += DUMP_CHUNK) {
969		if ((s.count - i) > DUMP_CHUNK) {
970			char c = s.buf[i + DUMP_CHUNK];
971			s.buf[i + DUMP_CHUNK] = 0;
972			pr_cont("%s", s.buf + i);
973			s.buf[i + DUMP_CHUNK] = c;
974		} else {
975			s.buf[s.count] = 0;
976			pr_cont("%s", s.buf + i);
977		}
978	}
979}
980#else
981static void sync_dump(void)
982{
983}
984#endif
985