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 	spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
234 	if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
235 		spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
236 		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
237 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
238 		dprintk("No output buffers available\n");
239 		return;
240 	}
241 	spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
242 	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
243 
244 	if (m2m_dev->m2m_ops->job_ready
245 		&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
246 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
247 		dprintk("Driver not ready\n");
248 		return;
249 	}
250 
251 	list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
252 	m2m_ctx->job_flags |= TRANS_QUEUED;
253 
254 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
255 
256 	v4l2_m2m_try_run(m2m_dev);
257 }
258 
259 /**
260  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
261  * and have it clean up
262  *
263  * Called by a driver to yield back the device after it has finished with it.
264  * Should be called as soon as possible after reaching a state which allows
265  * other instances to take control of the device.
266  *
267  * This function has to be called only after device_run() callback has been
268  * called on the driver. To prevent recursion, it should not be called directly
269  * from the device_run() callback though.
270  */
271 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
272 			 struct v4l2_m2m_ctx *m2m_ctx)
273 {
274 	unsigned long flags;
275 
276 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
277 	if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
278 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
279 		dprintk("Called by an instance not currently running\n");
280 		return;
281 	}
282 
283 	list_del(&m2m_dev->curr_ctx->queue);
284 	m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
285 	wake_up(&m2m_dev->curr_ctx->finished);
286 	m2m_dev->curr_ctx = NULL;
287 
288 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
289 
290 	/* This instance might have more buffers ready, but since we do not
291 	 * allow more than one job on the job_queue per instance, each has
292 	 * to be scheduled separately after the previous one finishes. */
293 	v4l2_m2m_try_schedule(m2m_ctx);
294 	v4l2_m2m_try_run(m2m_dev);
295 }
296 EXPORT_SYMBOL(v4l2_m2m_job_finish);
297 
298 /**
299  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
300  */
301 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
302 		     struct v4l2_requestbuffers *reqbufs)
303 {
304 	struct vb2_queue *vq;
305 
306 	vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
307 	return vb2_reqbufs(vq, reqbufs);
308 }
309 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
310 
311 /**
312  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
313  *
314  * See v4l2_m2m_mmap() documentation for details.
315  */
316 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
317 		      struct v4l2_buffer *buf)
318 {
319 	struct vb2_queue *vq;
320 	int ret = 0;
321 	unsigned int i;
322 
323 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
324 	ret = vb2_querybuf(vq, buf);
325 
326 	/* Adjust MMAP memory offsets for the CAPTURE queue */
327 	if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
328 		if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
329 			for (i = 0; i < buf->length; ++i)
330 				buf->m.planes[i].m.mem_offset
331 					+= DST_QUEUE_OFF_BASE;
332 		} else {
333 			buf->m.offset += DST_QUEUE_OFF_BASE;
334 		}
335 	}
336 
337 	return ret;
338 }
339 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
340 
341 /**
342  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
343  * the type
344  */
345 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
346 		  struct v4l2_buffer *buf)
347 {
348 	struct vb2_queue *vq;
349 	int ret;
350 
351 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
352 	ret = vb2_qbuf(vq, buf);
353 	if (!ret)
354 		v4l2_m2m_try_schedule(m2m_ctx);
355 
356 	return ret;
357 }
358 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
359 
360 /**
361  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
362  * the type
363  */
364 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
365 		   struct v4l2_buffer *buf)
366 {
367 	struct vb2_queue *vq;
368 
369 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
370 	return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
371 }
372 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
373 
374 /**
375  * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
376  * the type
377  */
378 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
379 		  struct v4l2_exportbuffer *eb)
380 {
381 	struct vb2_queue *vq;
382 
383 	vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
384 	return vb2_expbuf(vq, eb);
385 }
386 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
387 /**
388  * v4l2_m2m_streamon() - turn on streaming for a video queue
389  */
390 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
391 		      enum v4l2_buf_type type)
392 {
393 	struct vb2_queue *vq;
394 	int ret;
395 
396 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
397 	ret = vb2_streamon(vq, type);
398 	if (!ret)
399 		v4l2_m2m_try_schedule(m2m_ctx);
400 
401 	return ret;
402 }
403 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
404 
405 /**
406  * v4l2_m2m_streamoff() - turn off streaming for a video queue
407  */
408 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
409 		       enum v4l2_buf_type type)
410 {
411 	struct v4l2_m2m_dev *m2m_dev;
412 	struct v4l2_m2m_queue_ctx *q_ctx;
413 	unsigned long flags_job, flags;
414 	int ret;
415 
416 	q_ctx = get_queue_ctx(m2m_ctx, type);
417 	ret = vb2_streamoff(&q_ctx->q, type);
418 	if (ret)
419 		return ret;
420 
421 	m2m_dev = m2m_ctx->m2m_dev;
422 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
423 	/* We should not be scheduled anymore, since we're dropping a queue. */
424 	INIT_LIST_HEAD(&m2m_ctx->queue);
425 	m2m_ctx->job_flags = 0;
426 
427 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
428 	/* Drop queue, since streamoff returns device to the same state as after
429 	 * calling reqbufs. */
430 	INIT_LIST_HEAD(&q_ctx->rdy_queue);
431 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
432 
433 	if (m2m_dev->curr_ctx == m2m_ctx) {
434 		m2m_dev->curr_ctx = NULL;
435 		wake_up(&m2m_ctx->finished);
436 	}
437 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
438 
439 	return 0;
440 }
441 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
442 
443 /**
444  * v4l2_m2m_poll() - poll replacement, for destination buffers only
445  *
446  * Call from the driver's poll() function. Will poll both queues. If a buffer
447  * is available to dequeue (with dqbuf) from the source queue, this will
448  * indicate that a non-blocking write can be performed, while read will be
449  * returned in case of the destination queue.
450  */
451 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
452 			   struct poll_table_struct *wait)
453 {
454 	struct video_device *vfd = video_devdata(file);
455 	unsigned long req_events = poll_requested_events(wait);
456 	struct vb2_queue *src_q, *dst_q;
457 	struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
458 	unsigned int rc = 0;
459 	unsigned long flags;
460 
461 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
462 		struct v4l2_fh *fh = file->private_data;
463 
464 		if (v4l2_event_pending(fh))
465 			rc = POLLPRI;
466 		else if (req_events & POLLPRI)
467 			poll_wait(file, &fh->wait, wait);
468 		if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
469 			return rc;
470 	}
471 
472 	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
473 	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
474 
475 	/*
476 	 * There has to be at least one buffer queued on each queued_list, which
477 	 * means either in driver already or waiting for driver to claim it
478 	 * and start processing.
479 	 */
480 	if ((!src_q->streaming || list_empty(&src_q->queued_list))
481 		&& (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
482 		rc |= POLLERR;
483 		goto end;
484 	}
485 
486 	if (m2m_ctx->m2m_dev->m2m_ops->unlock)
487 		m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
488 
489 	poll_wait(file, &src_q->done_wq, wait);
490 	poll_wait(file, &dst_q->done_wq, wait);
491 
492 	if (m2m_ctx->m2m_dev->m2m_ops->lock)
493 		m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
494 
495 	spin_lock_irqsave(&src_q->done_lock, flags);
496 	if (!list_empty(&src_q->done_list))
497 		src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
498 						done_entry);
499 	if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
500 			|| src_vb->state == VB2_BUF_STATE_ERROR))
501 		rc |= POLLOUT | POLLWRNORM;
502 	spin_unlock_irqrestore(&src_q->done_lock, flags);
503 
504 	spin_lock_irqsave(&dst_q->done_lock, flags);
505 	if (!list_empty(&dst_q->done_list))
506 		dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
507 						done_entry);
508 	if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
509 			|| dst_vb->state == VB2_BUF_STATE_ERROR))
510 		rc |= POLLIN | POLLRDNORM;
511 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
512 
513 end:
514 	return rc;
515 }
516 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
517 
518 /**
519  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
520  *
521  * Call from driver's mmap() function. Will handle mmap() for both queues
522  * seamlessly for videobuffer, which will receive normal per-queue offsets and
523  * proper videobuf queue pointers. The differentiation is made outside videobuf
524  * by adding a predefined offset to buffers from one of the queues and
525  * subtracting it before passing it back to videobuf. Only drivers (and
526  * thus applications) receive modified offsets.
527  */
528 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
529 			 struct vm_area_struct *vma)
530 {
531 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
532 	struct vb2_queue *vq;
533 
534 	if (offset < DST_QUEUE_OFF_BASE) {
535 		vq = v4l2_m2m_get_src_vq(m2m_ctx);
536 	} else {
537 		vq = v4l2_m2m_get_dst_vq(m2m_ctx);
538 		vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
539 	}
540 
541 	return vb2_mmap(vq, vma);
542 }
543 EXPORT_SYMBOL(v4l2_m2m_mmap);
544 
545 /**
546  * v4l2_m2m_init() - initialize per-driver m2m data
547  *
548  * Usually called from driver's probe() function.
549  */
550 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
551 {
552 	struct v4l2_m2m_dev *m2m_dev;
553 
554 	if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
555 			WARN_ON(!m2m_ops->job_abort))
556 		return ERR_PTR(-EINVAL);
557 
558 	m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
559 	if (!m2m_dev)
560 		return ERR_PTR(-ENOMEM);
561 
562 	m2m_dev->curr_ctx = NULL;
563 	m2m_dev->m2m_ops = m2m_ops;
564 	INIT_LIST_HEAD(&m2m_dev->job_queue);
565 	spin_lock_init(&m2m_dev->job_spinlock);
566 
567 	return m2m_dev;
568 }
569 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
570 
571 /**
572  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
573  *
574  * Usually called from driver's remove() function.
575  */
576 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
577 {
578 	kfree(m2m_dev);
579 }
580 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
581 
582 /**
583  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
584  * @priv - driver's instance private data
585  * @m2m_dev - a previously initialized m2m_dev struct
586  * @vq_init - a callback for queue type-specific initialization function to be
587  * used for initializing videobuf_queues
588  *
589  * Usually called from driver's open() function.
590  */
591 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
592 		void *drv_priv,
593 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
594 {
595 	struct v4l2_m2m_ctx *m2m_ctx;
596 	struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
597 	int ret;
598 
599 	m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
600 	if (!m2m_ctx)
601 		return ERR_PTR(-ENOMEM);
602 
603 	m2m_ctx->priv = drv_priv;
604 	m2m_ctx->m2m_dev = m2m_dev;
605 	init_waitqueue_head(&m2m_ctx->finished);
606 
607 	out_q_ctx = &m2m_ctx->out_q_ctx;
608 	cap_q_ctx = &m2m_ctx->cap_q_ctx;
609 
610 	INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
611 	INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
612 	spin_lock_init(&out_q_ctx->rdy_spinlock);
613 	spin_lock_init(&cap_q_ctx->rdy_spinlock);
614 
615 	INIT_LIST_HEAD(&m2m_ctx->queue);
616 
617 	ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
618 
619 	if (ret)
620 		goto err;
621 
622 	return m2m_ctx;
623 err:
624 	kfree(m2m_ctx);
625 	return ERR_PTR(ret);
626 }
627 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
628 
629 /**
630  * v4l2_m2m_ctx_release() - release m2m context
631  *
632  * Usually called from driver's release() function.
633  */
634 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
635 {
636 	struct v4l2_m2m_dev *m2m_dev;
637 	unsigned long flags;
638 
639 	m2m_dev = m2m_ctx->m2m_dev;
640 
641 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
642 	if (m2m_ctx->job_flags & TRANS_RUNNING) {
643 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
644 		m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
645 		dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
646 		wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
647 	} else if (m2m_ctx->job_flags & TRANS_QUEUED) {
648 		list_del(&m2m_ctx->queue);
649 		m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
650 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
651 		dprintk("m2m_ctx: %p had been on queue and was removed\n",
652 			m2m_ctx);
653 	} else {
654 		/* Do nothing, was not on queue/running */
655 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
656 	}
657 
658 	vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
659 	vb2_queue_release(&m2m_ctx->out_q_ctx.q);
660 
661 	kfree(m2m_ctx);
662 }
663 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
664 
665 /**
666  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
667  *
668  * Call from buf_queue(), videobuf_queue_ops callback.
669  */
670 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
671 {
672 	struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
673 	struct v4l2_m2m_queue_ctx *q_ctx;
674 	unsigned long flags;
675 
676 	q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
677 	if (!q_ctx)
678 		return;
679 
680 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
681 	list_add_tail(&b->list, &q_ctx->rdy_queue);
682 	q_ctx->num_rdy++;
683 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
684 }
685 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
686 
687