summaryrefslogtreecommitdiffstats
path: root/drivers/media/video/v4l2-mem2mem.c
blob: 97b48318aee1826d3ad3bf5225efb93d053b02cc (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
/*
 * Memory-to-memory device framework for Video for Linux 2 and videobuf.
 *
 * Helper functions for devices that use videobuf buffers for both their
 * source and destination.
 *
 * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <pawel@osciak.com>
 * Marek Szyprowski, <m.szyprowski@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 */
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <media/videobuf2-core.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>

MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
MODULE_LICENSE("GPL");

static bool debug;
module_param(debug, bool, 0644);

#define dprintk(fmt, arg...)						\
	do {								\
		if (debug)						\
			printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
	} while (0)


/* Instance is already queued on the job_queue */
#define TRANS_QUEUED		(1 << 0)
/* Instance is currently running in hardware */
#define TRANS_RUNNING		(1 << 1)


/* Offset base for buffers on the destination queue - used to distinguish
 * between source and destination buffers when mmapping - they receive the same
 * offsets but for different queues */
#define DST_QUEUE_OFF_BASE	(1 << 30)


/**
 * struct v4l2_m2m_dev - per-device context
 * @curr_ctx:		currently running instance
 * @job_queue:		instances queued to run
 * @job_spinlock:	protects job_queue
 * @m2m_ops:		driver callbacks
 */
struct v4l2_m2m_dev {
	struct v4l2_m2m_ctx	*curr_ctx;

	struct list_head	job_queue;
	spinlock_t		job_spinlock;

	struct v4l2_m2m_ops	*m2m_ops;
};

static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
						enum v4l2_buf_type type)
{
	if (V4L2_TYPE_IS_OUTPUT(type))
		return &m2m_ctx->out_q_ctx;
	else
		return &m2m_ctx->cap_q_ctx;
}

/**
 * v4l2_m2m_get_vq() - return vb2_queue for the given type
 */
struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
				       enum v4l2_buf_type type)
{
	struct v4l2_m2m_queue_ctx *q_ctx;

	q_ctx = get_queue_ctx(m2m_ctx, type);
	if (!q_ctx)
		return NULL;

	return &q_ctx->q;
}
EXPORT_SYMBOL(v4l2_m2m_get_vq);

/**
 * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
 */
void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
{
	struct v4l2_m2m_buffer *b = NULL;
	unsigned long flags;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);

	if (list_empty(&q_ctx->rdy_queue)) {
		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
		return NULL;
	}

	b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
	return &b->vb;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);

/**
 * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
 * return it
 */
void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
{
	struct v4l2_m2m_buffer *b = NULL;
	unsigned long flags;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
	if (list_empty(&q_ctx->rdy_queue)) {
		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
		return NULL;
	}
	b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
	list_del(&b->list);
	q_ctx->num_rdy--;
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);

	return &b->vb;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);

/*
 * Scheduling handlers
 */

/**
 * v4l2_m2m_get_curr_priv() - return driver private data for the currently
 * running instance or NULL if no instance is running
 */
void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
{
	unsigned long flags;
	void *ret = NULL;

	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
	if (m2m_dev->curr_ctx)
		ret = m2m_dev->curr_ctx->priv;
	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);

	return ret;
}
EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);

/**
 * v4l2_m2m_try_run() - select next job to perform and run it if possible
 *
 * Get next transaction (if present) from the waiting jobs list and run it.
 */
static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
{
	unsigned long flags;

	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
	if (NULL != m2m_dev->curr_ctx) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
		dprintk("Another instance is running, won't run now\n");
		return;
	}

	if (list_empty(&m2m_dev->job_queue)) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
		dprintk("No job pending\n");
		return;
	}

	m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next,
				   struct v4l2_m2m_ctx, queue);
	m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);

	m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
}

/**
 * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
 * the pending job queue and add it if so.
 * @m2m_ctx:	m2m context assigned to the instance to be checked
 *
 * There are three basic requirements an instance has to meet to be able to run:
 * 1) at least one source buffer has to be queued,
 * 2) at least one destination buffer has to be queued,
 * 3) streaming has to be on.
 *
 * There may also be additional, custom requirements. In such case the driver
 * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
 * return 1 if the instance is ready.
 * An example of the above could be an instance that requires more than one
 * src/dst buffer per transaction.
 */
static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
{
	struct v4l2_m2m_dev *m2m_dev;
	unsigned long flags_job, flags;

	m2m_dev = m2m_ctx->m2m_dev;
	dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);

	if (!m2m_ctx->out_q_ctx.q.streaming
	    || !m2m_ctx->cap_q_ctx.q.streaming) {
		dprintk("Streaming needs to be on for both queues\n");
		return;
	}

	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
	if (m2m_ctx->job_flags & TRANS_QUEUED) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
		dprintk("On job queue already\n");
		return;
	}

	spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
	if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
		dprintk("No input buffers available\n");
		return;
	}
	if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
		dprintk("No output buffers available\n");
		return;
	}
	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);

	if (m2m_dev->m2m_ops->job_ready
		&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
		dprintk("Driver not ready\n");
		return;
	}

	list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
	m2m_ctx->job_flags |= TRANS_QUEUED;

	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);

	v4l2_m2m_try_run(m2m_dev);
}

/**
 * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 * and have it clean up
 *
 * Called by a driver to yield back the device after it has finished with it.
 * Should be called as soon as possible after reaching a state which allows
 * other instances to take control of the device.
 *
 * This function has to be called only after device_run() callback has been
 * called on the driver. To prevent recursion, it should not be called directly
 * from the device_run() callback though.
 */
void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
			 struct v4l2_m2m_ctx *m2m_ctx)
{
	unsigned long flags;

	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
	if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
		dprintk("Called by an instance not currently running\n");
		return;
	}

	list_del(&m2m_dev->curr_ctx->queue);
	m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
	wake_up(&m2m_dev->curr_ctx->finished);
	m2m_dev->curr_ctx = NULL;

	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);

	/* This instance might have more buffers ready, but since we do not
	 * allow more than one job on the job_queue per instance, each has
	 * to be scheduled separately after the previous one finishes. */
	v4l2_m2m_try_schedule(m2m_ctx);
	v4l2_m2m_try_run(m2m_dev);
}
EXPORT_SYMBOL(v4l2_m2m_job_finish);

/**
 * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 */
int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		     struct v4l2_requestbuffers *reqbufs)
{
	struct vb2_queue *vq;

	vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
	return vb2_reqbufs(vq, reqbufs);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);

/**
 * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 *
 * See v4l2_m2m_mmap() documentation for details.
 */
int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		      struct v4l2_buffer *buf)
{
	struct vb2_queue *vq;
	int ret = 0;
	unsigned int i;

	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
	ret = vb2_querybuf(vq, buf);

	/* Adjust MMAP memory offsets for the CAPTURE queue */
	if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
		if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
			for (i = 0; i < buf->length; ++i)
				buf->m.planes[i].m.mem_offset
					+= DST_QUEUE_OFF_BASE;
		} else {
			buf->m.offset += DST_QUEUE_OFF_BASE;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);

/**
 * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 * the type
 */
int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		  struct v4l2_buffer *buf)
{
	struct vb2_queue *vq;
	int ret;

	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
	ret = vb2_qbuf(vq, buf);
	if (!ret)
		v4l2_m2m_try_schedule(m2m_ctx);

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);

/**
 * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 * the type
 */
int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		   struct v4l2_buffer *buf)
{
	struct vb2_queue *vq;

	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
	return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);

/**
 * v4l2_m2m_streamon() - turn on streaming for a video queue
 */
int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		      enum v4l2_buf_type type)
{
	struct vb2_queue *vq;
	int ret;

	vq = v4l2_m2m_get_vq(m2m_ctx, type);
	ret = vb2_streamon(vq, type);
	if (!ret)
		v4l2_m2m_try_schedule(m2m_ctx);

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);

/**
 * v4l2_m2m_streamoff() - turn off streaming for a video queue
 */
int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
		       enum v4l2_buf_type type)
{
	struct vb2_queue *vq;

	vq = v4l2_m2m_get_vq(m2m_ctx, type);
	return vb2_streamoff(vq, type);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);

/**
 * v4l2_m2m_poll() - poll replacement, for destination buffers only
 *
 * Call from the driver's poll() function. Will poll both queues. If a buffer
 * is available to dequeue (with dqbuf) from the source queue, this will
 * indicate that a non-blocking write can be performed, while read will be
 * returned in case of the destination queue.
 */
unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
			   struct poll_table_struct *wait)
{
	struct video_device *vfd = video_devdata(file);
	unsigned long req_events = poll_requested_events(wait);
	struct vb2_queue *src_q, *dst_q;
	struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
	unsigned int rc = 0;
	unsigned long flags;

	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
		struct v4l2_fh *fh = file->private_data;

		if (v4l2_event_pending(fh))
			rc = POLLPRI;
		else if (req_events & POLLPRI)
			poll_wait(file, &fh->wait, wait);
		if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
			return rc;
	}

	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);

	/*
	 * There has to be at least one buffer queued on each queued_list, which
	 * means either in driver already or waiting for driver to claim it
	 * and start processing.
	 */
	if ((!src_q->streaming || list_empty(&src_q->queued_list))
		&& (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
		rc |= POLLERR;
		goto end;
	}

	if (m2m_ctx->m2m_dev->m2m_ops->unlock)
		m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);

	poll_wait(file, &src_q->done_wq, wait);
	poll_wait(file, &dst_q->done_wq, wait);

	if (m2m_ctx->m2m_dev->m2m_ops->lock)
		m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);

	spin_lock_irqsave(&src_q->done_lock, flags);
	if (!list_empty(&src_q->done_list))
		src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
						done_entry);
	if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
			|| src_vb->state == VB2_BUF_STATE_ERROR))
		rc |= POLLOUT | POLLWRNORM;
	spin_unlock_irqrestore(&src_q->done_lock, flags);

	spin_lock_irqsave(&dst_q->done_lock, flags);
	if (!list_empty(&dst_q->done_list))
		dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
						done_entry);
	if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
			|| dst_vb->state == VB2_BUF_STATE_ERROR))
		rc |= POLLIN | POLLRDNORM;
	spin_unlock_irqrestore(&dst_q->done_lock, flags);

end:
	return rc;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_poll);

/**
 * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 *
 * Call from driver's mmap() function. Will handle mmap() for both queues
 * seamlessly for videobuffer, which will receive normal per-queue offsets and
 * proper videobuf queue pointers. The differentiation is made outside videobuf
 * by adding a predefined offset to buffers from one of the queues and
 * subtracting it before passing it back to videobuf. Only drivers (and
 * thus applications) receive modified offsets.
 */
int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
			 struct vm_area_struct *vma)
{
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	struct vb2_queue *vq;

	if (offset < DST_QUEUE_OFF_BASE) {
		vq = v4l2_m2m_get_src_vq(m2m_ctx);
	} else {
		vq = v4l2_m2m_get_dst_vq(m2m_ctx);
		vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
	}

	return vb2_mmap(vq, vma);
}
EXPORT_SYMBOL(v4l2_m2m_mmap);

/**
 * v4l2_m2m_init() - initialize per-driver m2m data
 *
 * Usually called from driver's probe() function.
 */
struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops)
{
	struct v4l2_m2m_dev *m2m_dev;

	if (!m2m_ops)
		return ERR_PTR(-EINVAL);

	BUG_ON(!m2m_ops->device_run);
	BUG_ON(!m2m_ops->job_abort);

	m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
	if (!m2m_dev)
		return ERR_PTR(-ENOMEM);

	m2m_dev->curr_ctx = NULL;
	m2m_dev->m2m_ops = m2m_ops;
	INIT_LIST_HEAD(&m2m_dev->job_queue);
	spin_lock_init(&m2m_dev->job_spinlock);

	return m2m_dev;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_init);

/**
 * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 *
 * Usually called from driver's remove() function.
 */
void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
{
	kfree(m2m_dev);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_release);

/**
 * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 * @priv - driver's instance private data
 * @m2m_dev - a previously initialized m2m_dev struct
 * @vq_init - a callback for queue type-specific initialization function to be
 * used for initializing videobuf_queues
 *
 * Usually called from driver's open() function.
 */
struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
		void *drv_priv,
		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
{
	struct v4l2_m2m_ctx *m2m_ctx;
	struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
	int ret;

	m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
	if (!m2m_ctx)
		return ERR_PTR(-ENOMEM);

	m2m_ctx->priv = drv_priv;
	m2m_ctx->m2m_dev = m2m_dev;
	init_waitqueue_head(&m2m_ctx->finished);

	out_q_ctx = &m2m_ctx->out_q_ctx;
	cap_q_ctx = &m2m_ctx->cap_q_ctx;

	INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
	INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
	spin_lock_init(&out_q_ctx->rdy_spinlock);
	spin_lock_init(&cap_q_ctx->rdy_spinlock);

	INIT_LIST_HEAD(&m2m_ctx->queue);

	ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);

	if (ret)
		goto err;

	return m2m_ctx;
err:
	kfree(m2m_ctx);
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);

/**
 * v4l2_m2m_ctx_release() - release m2m context
 *
 * Usually called from driver's release() function.
 */
void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
{
	struct v4l2_m2m_dev *m2m_dev;
	unsigned long flags;

	m2m_dev = m2m_ctx->m2m_dev;

	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
	if (m2m_ctx->job_flags & TRANS_RUNNING) {
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
		m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
		dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
		wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
	} else if (m2m_ctx->job_flags & TRANS_QUEUED) {
		list_del(&m2m_ctx->queue);
		m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
		dprintk("m2m_ctx: %p had been on queue and was removed\n",
			m2m_ctx);
	} else {
		/* Do nothing, was not on queue/running */
		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
	}

	vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
	vb2_queue_release(&m2m_ctx->out_q_ctx.q);

	kfree(m2m_ctx);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);

/**
 * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 *
 * Call from buf_queue(), videobuf_queue_ops callback.
 */
void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
{
	struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
	struct v4l2_m2m_queue_ctx *q_ctx;
	unsigned long flags;

	q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
	if (!q_ctx)
		return;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
	list_add_tail(&b->list, &q_ctx->rdy_queue);
	q_ctx->num_rdy++;
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);