1 /*
2  * Memory-to-memory device framework for Video for Linux 2 and videobuf.
3  *
4  * Helper functions for devices that use videobuf buffers for both their
5  * source and destination.
6  *
7  * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
8  * Pawel Osciak, <pawel@osciak.com>
9  * Marek Szyprowski, <m.szyprowski@samsung.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by the
13  * Free Software Foundation; either version 2 of the License, or (at your
14  * option) any later version.
15  */
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 
20 #include <media/videobuf2-core.h>
21 #include <media/v4l2-mem2mem.h>
22 #include <media/v4l2-dev.h>
23 #include <media/v4l2-fh.h>
24 #include <media/v4l2-event.h>
25 
26 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
27 MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
28 MODULE_LICENSE("GPL");
29 
30 static bool debug;
31 module_param(debug, bool, 0644);
32 
33 #define dprintk(fmt, arg...)						\
34 	do {								\
35 		if (debug)						\
36 			printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
37 	} while (0)
38 
39 
40 /* Instance is already queued on the job_queue */
41 #define TRANS_QUEUED		(1 << 0)
42 /* Instance is currently running in hardware */
43 #define TRANS_RUNNING		(1 << 1)
44 
45 
46 /* Offset base for buffers on the destination queue - used to distinguish
47  * between source and destination buffers when mmapping - they receive the same
48  * offsets but for different queues */
49 #define DST_QUEUE_OFF_BASE	(1 << 30)
50 
51 
52 /**
53  * struct v4l2_m2m_dev - per-device context
54  * @curr_ctx:		currently running instance
55  * @job_queue:		instances queued to run
56  * @job_spinlock:	protects job_queue
57  * @m2m_ops:		driver callbacks
58  */
59 struct v4l2_m2m_dev {
60 	struct v4l2_m2m_ctx	*curr_ctx;
61 
62 	struct list_head	job_queue;
63 	spinlock_t		job_spinlock;
64 
65 	const struct v4l2_m2m_ops *m2m_ops;
66 };
67 
68 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
69 						enum v4l2_buf_type type)
70 {
71 	if (V4L2_TYPE_IS_OUTPUT(type))
72 		return &m2m_ctx->out_q_ctx;
73 	else
74 		return &m2m_ctx->cap_q_ctx;
75 }
76 
77 /**
78  * v4l2_m2m_get_vq() - return vb2_queue for the given type
79  */
80 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
81 				       enum v4l2_buf_type type)
82 {
83 	struct v4l2_m2m_queue_ctx *q_ctx;
84 
85 	q_ctx = get_queue_ctx(m2m_ctx, type);
86 	if (!q_ctx)
87 		return NULL;
88 
89 	return &q_ctx->q;
90 }
91 EXPORT_SYMBOL(v4l2_m2m_get_vq);
92 
93 /**
94  * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
95  */
96 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
97 {
98 	struct v4l2_m2m_buffer *b = NULL;
99 	unsigned long flags;
100 
101 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
102 
103 	if (list_empty(&q_ctx->rdy_queue)) {
104 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
105 		return NULL;
106 	}
107 
108 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
109 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
110 	return &b->vb;
111 }
112 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
113 
114 /**
115  * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
116  * return it
117  */
118 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
119 {
120 	struct v4l2_m2m_buffer *b = NULL;
121 	unsigned long flags;
122 
123 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
124 	if (list_empty(&q_ctx->rdy_queue)) {
125 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
126 		return NULL;
127 	}
128 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
129 	list_del(&b->list);
130 	q_ctx->num_rdy--;
131 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
132 
133 	return &b->vb;
134 }
135 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
136 
137 /*
138  * Scheduling handlers
139  */
140 
141 /**
142  * v4l2_m2m_get_curr_priv() - return driver private data for the currently
143  * running instance or NULL if no instance is running
144  */
145 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
146 {
147 	unsigned long flags;
148 	void *ret = NULL;
149 
150 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
151 	if (m2m_dev->curr_ctx)
152 		ret = m2m_dev->curr_ctx->priv;
153 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
154 
155 	return ret;
156 }
157 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
158 
159 /**
160  * v4l2_m2m_try_run() - select next job to perform and run it if possible
161  *
162  * Get next transaction (if present) from the waiting jobs list and run it.
163  */
164 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
165 {
166 	unsigned long flags;
167 
168 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
169 	if (NULL != m2m_dev->curr_ctx) {
170 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
171 		dprintk("Another instance is running, won't run now\n");
172 		return;
173 	}
174 
175 	if (list_empty(&m2m_dev->job_queue)) {
176 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
177 		dprintk("No job pending\n");
178 		return;
179 	}
180 
181 	m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
182 				   struct v4l2_m2m_ctx, queue);
183 	m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
184 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
185 
186 	m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
187 }
188 
189 /**
190  * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
191  * the pending job queue and add it if so.
192  * @m2m_ctx:	m2m context assigned to the instance to be checked
193  *
194  * There are three basic requirements an instance has to meet to be able to run:
195  * 1) at least one source buffer has to be queued,
196  * 2) at least one destination buffer has to be queued,
197  * 3) streaming has to be on.
198  *
199  * There may also be additional, custom requirements. In such case the driver
200  * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
201  * return 1 if the instance is ready.
202  * An example of the above could be an instance that requires more than one
203  * src/dst buffer per transaction.
204  */
205 static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
206 {
207 	struct v4l2_m2m_dev *m2m_dev;
208 	unsigned long flags_job, flags;
209 
210 	m2m_dev = m2m_ctx->m2m_dev;
211 	dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
212 
213 	if (!m2m_ctx->out_q_ctx.q.streaming
214 	    || !m2m_ctx->cap_q_ctx.q.streaming) {
215 		dprintk("Streaming needs to be on for both queues\n");
216 		return;
217 	}
218 
219 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
220 	if (m2m_ctx->job_flags & TRANS_QUEUED) {
221 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
222 		dprintk("On job queue already\n");
223 		return;
224 	}
225 
226 	spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
227 	if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
228 		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
229 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
230 		dprintk("No input buffers available\n");
231 		return;
232 	}
233 	if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
234 		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
235 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
236 		dprintk("No output buffers available\n");
237 		return;
238 	}
239 	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
240 
241 	if (m2m_dev->m2m_ops->job_ready
242 		&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
243 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
244 		dprintk("Driver not ready\n");
245 		return;
246 	}
247 
248 	list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
249 	m2m_ctx->job_flags |= TRANS_QUEUED;
250 
251 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
252 
253 	v4l2_m2m_try_run(m2m_dev);
254 }
255 
256 /**
257  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
258  * and have it clean up
259  *
260  * Called by a driver to yield back the device after it has finished with it.
261  * Should be called as soon as possible after reaching a state which allows
262  * other instances to take control of the device.
263  *
264  * This function has to be called only after device_run() callback has been
265  * called on the driver. To prevent recursion, it should not be called directly
266  * from the device_run() callback though.
267  */
268 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
269 			 struct v4l2_m2m_ctx *m2m_ctx)
270 {
271 	unsigned long flags;
272 
273 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
274 	if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
275 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
276 		dprintk("Called by an instance not currently running\n");
277 		return;
278 	}
279 
280 	list_del(&m2m_dev->curr_ctx->queue);
281 	m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
282 	wake_up(&m2m_dev->curr_ctx->finished);
283 	m2m_dev->curr_ctx = NULL;
284 
285 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
286 
287 	/* This instance might have more buffers ready, but since we do not
288 	 * allow more than one job on the job_queue per instance, each has
289 	 * to be scheduled separately after the previous one finishes. */
290 	v4l2_m2m_try_schedule(m2m_ctx);
291 	v4l2_m2m_try_run(m2m_dev);
292 }
293 EXPORT_SYMBOL(v4l2_m2m_job_finish);
294 
295 /**
296  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
297  */
298 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
299 		     struct v4l2_requestbuffers *reqbufs)
300 {
301 	struct vb2_queue *vq;
302 
303 	vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
304 	return vb2_reqbufs(vq, reqbufs);
305 }
306 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
307 
308 /**
309  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
310  *
311  * See v4l2_m2m_mmap() documentation for details.
312  */
313 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
314 		      struct v4l2_buffer *buf)
315 {
316 	struct vb2_queue *vq;
317 	int ret = 0;
318 	unsigned int i;
319 
320 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
321 	ret = vb2_querybuf(vq, buf);
322 
323 	/* Adjust MMAP memory offsets for the CAPTURE queue */
324 	if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
325 		if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
326 			for (i = 0; i < buf->length; ++i)
327 				buf->m.planes[i].m.mem_offset
328 					+= DST_QUEUE_OFF_BASE;
329 		} else {
330 			buf->m.offset += DST_QUEUE_OFF_BASE;
331 		}
332 	}
333 
334 	return ret;
335 }
336 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
337 
338 /**
339  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
340  * the type
341  */
342 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
343 		  struct v4l2_buffer *buf)
344 {
345 	struct vb2_queue *vq;
346 	int ret;
347 
348 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
349 	ret = vb2_qbuf(vq, buf);
350 	if (!ret)
351 		v4l2_m2m_try_schedule(m2m_ctx);
352 
353 	return ret;
354 }
355 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
356 
357 /**
358  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
359  * the type
360  */
361 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
362 		   struct v4l2_buffer *buf)
363 {
364 	struct vb2_queue *vq;
365 
366 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
367 	return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
368 }
369 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
370 
371 /**
372  * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
373  * the type
374  */
375 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
376 		  struct v4l2_exportbuffer *eb)
377 {
378 	struct vb2_queue *vq;
379 
380 	vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
381 	return vb2_expbuf(vq, eb);
382 }
383 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
384 /**
385  * v4l2_m2m_streamon() - turn on streaming for a video queue
386  */
387 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
388 		      enum v4l2_buf_type type)
389 {
390 	struct vb2_queue *vq;
391 	int ret;
392 
393 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
394 	ret = vb2_streamon(vq, type);
395 	if (!ret)
396 		v4l2_m2m_try_schedule(m2m_ctx);
397 
398 	return ret;
399 }
400 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
401 
402 /**
403  * v4l2_m2m_streamoff() - turn off streaming for a video queue
404  */
405 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
406 		       enum v4l2_buf_type type)
407 {
408 	struct vb2_queue *vq;
409 
410 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
411 	return vb2_streamoff(vq, type);
412 }
413 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
414 
415 /**
416  * v4l2_m2m_poll() - poll replacement, for destination buffers only
417  *
418  * Call from the driver's poll() function. Will poll both queues. If a buffer
419  * is available to dequeue (with dqbuf) from the source queue, this will
420  * indicate that a non-blocking write can be performed, while read will be
421  * returned in case of the destination queue.
422  */
423 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
424 			   struct poll_table_struct *wait)
425 {
426 	struct video_device *vfd = video_devdata(file);
427 	unsigned long req_events = poll_requested_events(wait);
428 	struct vb2_queue *src_q, *dst_q;
429 	struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
430 	unsigned int rc = 0;
431 	unsigned long flags;
432 
433 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
434 		struct v4l2_fh *fh = file->private_data;
435 
436 		if (v4l2_event_pending(fh))
437 			rc = POLLPRI;
438 		else if (req_events & POLLPRI)
439 			poll_wait(file, &fh->wait, wait);
440 		if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
441 			return rc;
442 	}
443 
444 	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
445 	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
446 
447 	/*
448 	 * There has to be at least one buffer queued on each queued_list, which
449 	 * means either in driver already or waiting for driver to claim it
450 	 * and start processing.
451 	 */
452 	if ((!src_q->streaming || list_empty(&src_q->queued_list))
453 		&& (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
454 		rc |= POLLERR;
455 		goto end;
456 	}
457 
458 	if (m2m_ctx->m2m_dev->m2m_ops->unlock)
459 		m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
460 
461 	poll_wait(file, &src_q->done_wq, wait);
462 	poll_wait(file, &dst_q->done_wq, wait);
463 
464 	if (m2m_ctx->m2m_dev->m2m_ops->lock)
465 		m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
466 
467 	spin_lock_irqsave(&src_q->done_lock, flags);
468 	if (!list_empty(&src_q->done_list))
469 		src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
470 						done_entry);
471 	if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
472 			|| src_vb->state == VB2_BUF_STATE_ERROR))
473 		rc |= POLLOUT | POLLWRNORM;
474 	spin_unlock_irqrestore(&src_q->done_lock, flags);
475 
476 	spin_lock_irqsave(&dst_q->done_lock, flags);
477 	if (!list_empty(&dst_q->done_list))
478 		dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
479 						done_entry);
480 	if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
481 			|| dst_vb->state == VB2_BUF_STATE_ERROR))
482 		rc |= POLLIN | POLLRDNORM;
483 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
484 
485 end:
486 	return rc;
487 }
488 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
489 
490 /**
491  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
492  *
493  * Call from driver's mmap() function. Will handle mmap() for both queues
494  * seamlessly for videobuffer, which will receive normal per-queue offsets and
495  * proper videobuf queue pointers. The differentiation is made outside videobuf
496  * by adding a predefined offset to buffers from one of the queues and
497  * subtracting it before passing it back to videobuf. Only drivers (and
498  * thus applications) receive modified offsets.
499  */
500 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
501 			 struct vm_area_struct *vma)
502 {
503 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
504 	struct vb2_queue *vq;
505 
506 	if (offset < DST_QUEUE_OFF_BASE) {
507 		vq = v4l2_m2m_get_src_vq(m2m_ctx);
508 	} else {
509 		vq = v4l2_m2m_get_dst_vq(m2m_ctx);
510 		vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
511 	}
512 
513 	return vb2_mmap(vq, vma);
514 }
515 EXPORT_SYMBOL(v4l2_m2m_mmap);
516 
517 /**
518  * v4l2_m2m_init() - initialize per-driver m2m data
519  *
520  * Usually called from driver's probe() function.
521  */
522 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
523 {
524 	struct v4l2_m2m_dev *m2m_dev;
525 
526 	if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
527 			WARN_ON(!m2m_ops->job_abort))
528 		return ERR_PTR(-EINVAL);
529 
530 	m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
531 	if (!m2m_dev)
532 		return ERR_PTR(-ENOMEM);
533 
534 	m2m_dev->curr_ctx = NULL;
535 	m2m_dev->m2m_ops = m2m_ops;
536 	INIT_LIST_HEAD(&m2m_dev->job_queue);
537 	spin_lock_init(&m2m_dev->job_spinlock);
538 
539 	return m2m_dev;
540 }
541 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
542 
543 /**
544  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
545  *
546  * Usually called from driver's remove() function.
547  */
548 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
549 {
550 	kfree(m2m_dev);
551 }
552 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
553 
554 /**
555  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
556  * @priv - driver's instance private data
557  * @m2m_dev - a previously initialized m2m_dev struct
558  * @vq_init - a callback for queue type-specific initialization function to be
559  * used for initializing videobuf_queues
560  *
561  * Usually called from driver's open() function.
562  */
563 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
564 		void *drv_priv,
565 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
566 {
567 	struct v4l2_m2m_ctx *m2m_ctx;
568 	struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
569 	int ret;
570 
571 	m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
572 	if (!m2m_ctx)
573 		return ERR_PTR(-ENOMEM);
574 
575 	m2m_ctx->priv = drv_priv;
576 	m2m_ctx->m2m_dev = m2m_dev;
577 	init_waitqueue_head(&m2m_ctx->finished);
578 
579 	out_q_ctx = &m2m_ctx->out_q_ctx;
580 	cap_q_ctx = &m2m_ctx->cap_q_ctx;
581 
582 	INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
583 	INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
584 	spin_lock_init(&out_q_ctx->rdy_spinlock);
585 	spin_lock_init(&cap_q_ctx->rdy_spinlock);
586 
587 	INIT_LIST_HEAD(&m2m_ctx->queue);
588 
589 	ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
590 
591 	if (ret)
592 		goto err;
593 
594 	return m2m_ctx;
595 err:
596 	kfree(m2m_ctx);
597 	return ERR_PTR(ret);
598 }
599 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
600 
601 /**
602  * v4l2_m2m_ctx_release() - release m2m context
603  *
604  * Usually called from driver's release() function.
605  */
606 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
607 {
608 	struct v4l2_m2m_dev *m2m_dev;
609 	unsigned long flags;
610 
611 	m2m_dev = m2m_ctx->m2m_dev;
612 
613 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
614 	if (m2m_ctx->job_flags & TRANS_RUNNING) {
615 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
616 		m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
617 		dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
618 		wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
619 	} else if (m2m_ctx->job_flags & TRANS_QUEUED) {
620 		list_del(&m2m_ctx->queue);
621 		m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
622 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
623 		dprintk("m2m_ctx: %p had been on queue and was removed\n",
624 			m2m_ctx);
625 	} else {
626 		/* Do nothing, was not on queue/running */
627 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
628 	}
629 
630 	vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
631 	vb2_queue_release(&m2m_ctx->out_q_ctx.q);
632 
633 	kfree(m2m_ctx);
634 }
635 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
636 
637 /**
638  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
639  *
640  * Call from buf_queue(), videobuf_queue_ops callback.
641  */
642 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
643 {
644 	struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
645 	struct v4l2_m2m_queue_ctx *q_ctx;
646 	unsigned long flags;
647 
648 	q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
649 	if (!q_ctx)
650 		return;
651 
652 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
653 	list_add_tail(&b->list, &q_ctx->rdy_queue);
654 	q_ctx->num_rdy++;
655 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
656 }
657 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
658 
659