xref: /openbmc/linux/drivers/media/v4l2-core/v4l2-mem2mem.c (revision da27ef68751f804dbe6c2b84a49848f90ae48fd0)
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/media-device.h>
21 #include <media/videobuf2-v4l2.h>
22 #include <media/v4l2-mem2mem.h>
23 #include <media/v4l2-dev.h>
24 #include <media/v4l2-device.h>
25 #include <media/v4l2-fh.h>
26 #include <media/v4l2-event.h>
27 
28 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
29 MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
30 MODULE_LICENSE("GPL");
31 
32 static bool debug;
33 module_param(debug, bool, 0644);
34 
35 #define dprintk(fmt, arg...)						\
36 	do {								\
37 		if (debug)						\
38 			printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
39 	} while (0)
40 
41 
42 /* Instance is already queued on the job_queue */
43 #define TRANS_QUEUED		(1 << 0)
44 /* Instance is currently running in hardware */
45 #define TRANS_RUNNING		(1 << 1)
46 /* Instance is currently aborting */
47 #define TRANS_ABORT		(1 << 2)
48 
49 
50 /* Offset base for buffers on the destination queue - used to distinguish
51  * between source and destination buffers when mmapping - they receive the same
52  * offsets but for different queues */
53 #define DST_QUEUE_OFF_BASE	(1 << 30)
54 
55 enum v4l2_m2m_entity_type {
56 	MEM2MEM_ENT_TYPE_SOURCE,
57 	MEM2MEM_ENT_TYPE_SINK,
58 	MEM2MEM_ENT_TYPE_PROC
59 };
60 
61 static const char * const m2m_entity_name[] = {
62 	"source",
63 	"sink",
64 	"proc"
65 };
66 
67 /**
68  * struct v4l2_m2m_dev - per-device context
69  * @curr_ctx:		currently running instance
70  * @job_queue:		instances queued to run
71  * @job_spinlock:	protects job_queue
72  * @m2m_ops:		driver callbacks
73  */
74 struct v4l2_m2m_dev {
75 	struct v4l2_m2m_ctx	*curr_ctx;
76 #ifdef CONFIG_MEDIA_CONTROLLER
77 	struct media_entity	*source;
78 	struct media_pad	source_pad;
79 	struct media_entity	sink;
80 	struct media_pad	sink_pad;
81 	struct media_entity	proc;
82 	struct media_pad	proc_pads[2];
83 	struct media_intf_devnode *intf_devnode;
84 #endif
85 
86 	struct list_head	job_queue;
87 	spinlock_t		job_spinlock;
88 
89 	const struct v4l2_m2m_ops *m2m_ops;
90 };
91 
92 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
93 						enum v4l2_buf_type type)
94 {
95 	if (V4L2_TYPE_IS_OUTPUT(type))
96 		return &m2m_ctx->out_q_ctx;
97 	else
98 		return &m2m_ctx->cap_q_ctx;
99 }
100 
101 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
102 				       enum v4l2_buf_type type)
103 {
104 	struct v4l2_m2m_queue_ctx *q_ctx;
105 
106 	q_ctx = get_queue_ctx(m2m_ctx, type);
107 	if (!q_ctx)
108 		return NULL;
109 
110 	return &q_ctx->q;
111 }
112 EXPORT_SYMBOL(v4l2_m2m_get_vq);
113 
114 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
115 {
116 	struct v4l2_m2m_buffer *b;
117 	unsigned long flags;
118 
119 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
120 
121 	if (list_empty(&q_ctx->rdy_queue)) {
122 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
123 		return NULL;
124 	}
125 
126 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
127 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
128 	return &b->vb;
129 }
130 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
131 
132 void *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx)
133 {
134 	struct v4l2_m2m_buffer *b;
135 	unsigned long flags;
136 
137 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
138 
139 	if (list_empty(&q_ctx->rdy_queue)) {
140 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
141 		return NULL;
142 	}
143 
144 	b = list_last_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
145 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
146 	return &b->vb;
147 }
148 EXPORT_SYMBOL_GPL(v4l2_m2m_last_buf);
149 
150 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
151 {
152 	struct v4l2_m2m_buffer *b;
153 	unsigned long flags;
154 
155 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
156 	if (list_empty(&q_ctx->rdy_queue)) {
157 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
158 		return NULL;
159 	}
160 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
161 	list_del(&b->list);
162 	q_ctx->num_rdy--;
163 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
164 
165 	return &b->vb;
166 }
167 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
168 
169 void v4l2_m2m_buf_remove_by_buf(struct v4l2_m2m_queue_ctx *q_ctx,
170 				struct vb2_v4l2_buffer *vbuf)
171 {
172 	struct v4l2_m2m_buffer *b;
173 	unsigned long flags;
174 
175 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
176 	b = container_of(vbuf, struct v4l2_m2m_buffer, vb);
177 	list_del(&b->list);
178 	q_ctx->num_rdy--;
179 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
180 }
181 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_buf);
182 
183 struct vb2_v4l2_buffer *
184 v4l2_m2m_buf_remove_by_idx(struct v4l2_m2m_queue_ctx *q_ctx, unsigned int idx)
185 
186 {
187 	struct v4l2_m2m_buffer *b, *tmp;
188 	struct vb2_v4l2_buffer *ret = NULL;
189 	unsigned long flags;
190 
191 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
192 	list_for_each_entry_safe(b, tmp, &q_ctx->rdy_queue, list) {
193 		if (b->vb.vb2_buf.index == idx) {
194 			list_del(&b->list);
195 			q_ctx->num_rdy--;
196 			ret = &b->vb;
197 			break;
198 		}
199 	}
200 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
201 
202 	return ret;
203 }
204 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_idx);
205 
206 /*
207  * Scheduling handlers
208  */
209 
210 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
211 {
212 	unsigned long flags;
213 	void *ret = NULL;
214 
215 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
216 	if (m2m_dev->curr_ctx)
217 		ret = m2m_dev->curr_ctx->priv;
218 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
219 
220 	return ret;
221 }
222 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
223 
224 /**
225  * v4l2_m2m_try_run() - select next job to perform and run it if possible
226  * @m2m_dev: per-device context
227  *
228  * Get next transaction (if present) from the waiting jobs list and run it.
229  */
230 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
231 {
232 	unsigned long flags;
233 
234 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
235 	if (NULL != m2m_dev->curr_ctx) {
236 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
237 		dprintk("Another instance is running, won't run now\n");
238 		return;
239 	}
240 
241 	if (list_empty(&m2m_dev->job_queue)) {
242 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
243 		dprintk("No job pending\n");
244 		return;
245 	}
246 
247 	m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
248 				   struct v4l2_m2m_ctx, queue);
249 	m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
250 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
251 
252 	m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
253 }
254 
255 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
256 {
257 	struct v4l2_m2m_dev *m2m_dev;
258 	unsigned long flags_job, flags_out, flags_cap;
259 
260 	m2m_dev = m2m_ctx->m2m_dev;
261 	dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
262 
263 	if (!m2m_ctx->out_q_ctx.q.streaming
264 	    || !m2m_ctx->cap_q_ctx.q.streaming) {
265 		dprintk("Streaming needs to be on for both queues\n");
266 		return;
267 	}
268 
269 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
270 
271 	/* If the context is aborted then don't schedule it */
272 	if (m2m_ctx->job_flags & TRANS_ABORT) {
273 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
274 		dprintk("Aborted context\n");
275 		return;
276 	}
277 
278 	if (m2m_ctx->job_flags & TRANS_QUEUED) {
279 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
280 		dprintk("On job queue already\n");
281 		return;
282 	}
283 
284 	spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
285 	if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)
286 	    && !m2m_ctx->out_q_ctx.buffered) {
287 		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
288 					flags_out);
289 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
290 		dprintk("No input buffers available\n");
291 		return;
292 	}
293 	spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
294 	if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)
295 	    && !m2m_ctx->cap_q_ctx.buffered) {
296 		spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock,
297 					flags_cap);
298 		spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
299 					flags_out);
300 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
301 		dprintk("No output buffers available\n");
302 		return;
303 	}
304 	spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
305 	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
306 
307 	if (m2m_dev->m2m_ops->job_ready
308 		&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
309 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
310 		dprintk("Driver not ready\n");
311 		return;
312 	}
313 
314 	list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
315 	m2m_ctx->job_flags |= TRANS_QUEUED;
316 
317 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
318 
319 	v4l2_m2m_try_run(m2m_dev);
320 }
321 EXPORT_SYMBOL_GPL(v4l2_m2m_try_schedule);
322 
323 /**
324  * v4l2_m2m_cancel_job() - cancel pending jobs for the context
325  * @m2m_ctx: m2m context with jobs to be canceled
326  *
327  * In case of streamoff or release called on any context,
328  * 1] If the context is currently running, then abort job will be called
329  * 2] If the context is queued, then the context will be removed from
330  *    the job_queue
331  */
332 static void v4l2_m2m_cancel_job(struct v4l2_m2m_ctx *m2m_ctx)
333 {
334 	struct v4l2_m2m_dev *m2m_dev;
335 	unsigned long flags;
336 
337 	m2m_dev = m2m_ctx->m2m_dev;
338 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
339 
340 	m2m_ctx->job_flags |= TRANS_ABORT;
341 	if (m2m_ctx->job_flags & TRANS_RUNNING) {
342 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
343 		if (m2m_dev->m2m_ops->job_abort)
344 			m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
345 		dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
346 		wait_event(m2m_ctx->finished,
347 				!(m2m_ctx->job_flags & TRANS_RUNNING));
348 	} else if (m2m_ctx->job_flags & TRANS_QUEUED) {
349 		list_del(&m2m_ctx->queue);
350 		m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
351 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
352 		dprintk("m2m_ctx: %p had been on queue and was removed\n",
353 			m2m_ctx);
354 	} else {
355 		/* Do nothing, was not on queue/running */
356 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
357 	}
358 }
359 
360 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
361 			 struct v4l2_m2m_ctx *m2m_ctx)
362 {
363 	unsigned long flags;
364 
365 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
366 	if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
367 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
368 		dprintk("Called by an instance not currently running\n");
369 		return;
370 	}
371 
372 	list_del(&m2m_dev->curr_ctx->queue);
373 	m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
374 	wake_up(&m2m_dev->curr_ctx->finished);
375 	m2m_dev->curr_ctx = NULL;
376 
377 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
378 
379 	/* This instance might have more buffers ready, but since we do not
380 	 * allow more than one job on the job_queue per instance, each has
381 	 * to be scheduled separately after the previous one finishes. */
382 	v4l2_m2m_try_schedule(m2m_ctx);
383 }
384 EXPORT_SYMBOL(v4l2_m2m_job_finish);
385 
386 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
387 		     struct v4l2_requestbuffers *reqbufs)
388 {
389 	struct vb2_queue *vq;
390 	int ret;
391 
392 	vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
393 	ret = vb2_reqbufs(vq, reqbufs);
394 	/* If count == 0, then the owner has released all buffers and he
395 	   is no longer owner of the queue. Otherwise we have an owner. */
396 	if (ret == 0)
397 		vq->owner = reqbufs->count ? file->private_data : NULL;
398 
399 	return ret;
400 }
401 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
402 
403 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
404 		      struct v4l2_buffer *buf)
405 {
406 	struct vb2_queue *vq;
407 	int ret = 0;
408 	unsigned int i;
409 
410 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
411 	ret = vb2_querybuf(vq, buf);
412 
413 	/* Adjust MMAP memory offsets for the CAPTURE queue */
414 	if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
415 		if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
416 			for (i = 0; i < buf->length; ++i)
417 				buf->m.planes[i].m.mem_offset
418 					+= DST_QUEUE_OFF_BASE;
419 		} else {
420 			buf->m.offset += DST_QUEUE_OFF_BASE;
421 		}
422 	}
423 
424 	return ret;
425 }
426 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
427 
428 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
429 		  struct v4l2_buffer *buf)
430 {
431 	struct vb2_queue *vq;
432 	int ret;
433 
434 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
435 	ret = vb2_qbuf(vq, buf);
436 	if (!ret)
437 		v4l2_m2m_try_schedule(m2m_ctx);
438 
439 	return ret;
440 }
441 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
442 
443 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
444 		   struct v4l2_buffer *buf)
445 {
446 	struct vb2_queue *vq;
447 
448 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
449 	return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
450 }
451 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
452 
453 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
454 			 struct v4l2_buffer *buf)
455 {
456 	struct vb2_queue *vq;
457 	int ret;
458 
459 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
460 	ret = vb2_prepare_buf(vq, buf);
461 	if (!ret)
462 		v4l2_m2m_try_schedule(m2m_ctx);
463 
464 	return ret;
465 }
466 EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf);
467 
468 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
469 			 struct v4l2_create_buffers *create)
470 {
471 	struct vb2_queue *vq;
472 
473 	vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
474 	return vb2_create_bufs(vq, create);
475 }
476 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
477 
478 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
479 		  struct v4l2_exportbuffer *eb)
480 {
481 	struct vb2_queue *vq;
482 
483 	vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
484 	return vb2_expbuf(vq, eb);
485 }
486 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
487 
488 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
489 		      enum v4l2_buf_type type)
490 {
491 	struct vb2_queue *vq;
492 	int ret;
493 
494 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
495 	ret = vb2_streamon(vq, type);
496 	if (!ret)
497 		v4l2_m2m_try_schedule(m2m_ctx);
498 
499 	return ret;
500 }
501 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
502 
503 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
504 		       enum v4l2_buf_type type)
505 {
506 	struct v4l2_m2m_dev *m2m_dev;
507 	struct v4l2_m2m_queue_ctx *q_ctx;
508 	unsigned long flags_job, flags;
509 	int ret;
510 
511 	/* wait until the current context is dequeued from job_queue */
512 	v4l2_m2m_cancel_job(m2m_ctx);
513 
514 	q_ctx = get_queue_ctx(m2m_ctx, type);
515 	ret = vb2_streamoff(&q_ctx->q, type);
516 	if (ret)
517 		return ret;
518 
519 	m2m_dev = m2m_ctx->m2m_dev;
520 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
521 	/* We should not be scheduled anymore, since we're dropping a queue. */
522 	if (m2m_ctx->job_flags & TRANS_QUEUED)
523 		list_del(&m2m_ctx->queue);
524 	m2m_ctx->job_flags = 0;
525 
526 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
527 	/* Drop queue, since streamoff returns device to the same state as after
528 	 * calling reqbufs. */
529 	INIT_LIST_HEAD(&q_ctx->rdy_queue);
530 	q_ctx->num_rdy = 0;
531 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
532 
533 	if (m2m_dev->curr_ctx == m2m_ctx) {
534 		m2m_dev->curr_ctx = NULL;
535 		wake_up(&m2m_ctx->finished);
536 	}
537 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
538 
539 	return 0;
540 }
541 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
542 
543 __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
544 			   struct poll_table_struct *wait)
545 {
546 	struct video_device *vfd = video_devdata(file);
547 	__poll_t req_events = poll_requested_events(wait);
548 	struct vb2_queue *src_q, *dst_q;
549 	struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
550 	__poll_t rc = 0;
551 	unsigned long flags;
552 
553 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
554 		struct v4l2_fh *fh = file->private_data;
555 
556 		if (v4l2_event_pending(fh))
557 			rc = EPOLLPRI;
558 		else if (req_events & EPOLLPRI)
559 			poll_wait(file, &fh->wait, wait);
560 		if (!(req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM)))
561 			return rc;
562 	}
563 
564 	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
565 	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
566 
567 	/*
568 	 * There has to be at least one buffer queued on each queued_list, which
569 	 * means either in driver already or waiting for driver to claim it
570 	 * and start processing.
571 	 */
572 	if ((!src_q->streaming || list_empty(&src_q->queued_list))
573 		&& (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
574 		rc |= EPOLLERR;
575 		goto end;
576 	}
577 
578 	spin_lock_irqsave(&src_q->done_lock, flags);
579 	if (list_empty(&src_q->done_list))
580 		poll_wait(file, &src_q->done_wq, wait);
581 	spin_unlock_irqrestore(&src_q->done_lock, flags);
582 
583 	spin_lock_irqsave(&dst_q->done_lock, flags);
584 	if (list_empty(&dst_q->done_list)) {
585 		/*
586 		 * If the last buffer was dequeued from the capture queue,
587 		 * return immediately. DQBUF will return -EPIPE.
588 		 */
589 		if (dst_q->last_buffer_dequeued) {
590 			spin_unlock_irqrestore(&dst_q->done_lock, flags);
591 			return rc | EPOLLIN | EPOLLRDNORM;
592 		}
593 
594 		poll_wait(file, &dst_q->done_wq, wait);
595 	}
596 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
597 
598 	spin_lock_irqsave(&src_q->done_lock, flags);
599 	if (!list_empty(&src_q->done_list))
600 		src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
601 						done_entry);
602 	if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
603 			|| src_vb->state == VB2_BUF_STATE_ERROR))
604 		rc |= EPOLLOUT | EPOLLWRNORM;
605 	spin_unlock_irqrestore(&src_q->done_lock, flags);
606 
607 	spin_lock_irqsave(&dst_q->done_lock, flags);
608 	if (!list_empty(&dst_q->done_list))
609 		dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
610 						done_entry);
611 	if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
612 			|| dst_vb->state == VB2_BUF_STATE_ERROR))
613 		rc |= EPOLLIN | EPOLLRDNORM;
614 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
615 
616 end:
617 	return rc;
618 }
619 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
620 
621 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
622 			 struct vm_area_struct *vma)
623 {
624 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
625 	struct vb2_queue *vq;
626 
627 	if (offset < DST_QUEUE_OFF_BASE) {
628 		vq = v4l2_m2m_get_src_vq(m2m_ctx);
629 	} else {
630 		vq = v4l2_m2m_get_dst_vq(m2m_ctx);
631 		vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
632 	}
633 
634 	return vb2_mmap(vq, vma);
635 }
636 EXPORT_SYMBOL(v4l2_m2m_mmap);
637 
638 #if defined(CONFIG_MEDIA_CONTROLLER)
639 void v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev)
640 {
641 	media_remove_intf_links(&m2m_dev->intf_devnode->intf);
642 	media_devnode_remove(m2m_dev->intf_devnode);
643 
644 	media_entity_remove_links(m2m_dev->source);
645 	media_entity_remove_links(&m2m_dev->sink);
646 	media_entity_remove_links(&m2m_dev->proc);
647 	media_device_unregister_entity(m2m_dev->source);
648 	media_device_unregister_entity(&m2m_dev->sink);
649 	media_device_unregister_entity(&m2m_dev->proc);
650 	kfree(m2m_dev->source->name);
651 	kfree(m2m_dev->sink.name);
652 	kfree(m2m_dev->proc.name);
653 }
654 EXPORT_SYMBOL_GPL(v4l2_m2m_unregister_media_controller);
655 
656 static int v4l2_m2m_register_entity(struct media_device *mdev,
657 	struct v4l2_m2m_dev *m2m_dev, enum v4l2_m2m_entity_type type,
658 	struct video_device *vdev, int function)
659 {
660 	struct media_entity *entity;
661 	struct media_pad *pads;
662 	char *name;
663 	unsigned int len;
664 	int num_pads;
665 	int ret;
666 
667 	switch (type) {
668 	case MEM2MEM_ENT_TYPE_SOURCE:
669 		entity = m2m_dev->source;
670 		pads = &m2m_dev->source_pad;
671 		pads[0].flags = MEDIA_PAD_FL_SOURCE;
672 		num_pads = 1;
673 		break;
674 	case MEM2MEM_ENT_TYPE_SINK:
675 		entity = &m2m_dev->sink;
676 		pads = &m2m_dev->sink_pad;
677 		pads[0].flags = MEDIA_PAD_FL_SINK;
678 		num_pads = 1;
679 		break;
680 	case MEM2MEM_ENT_TYPE_PROC:
681 		entity = &m2m_dev->proc;
682 		pads = m2m_dev->proc_pads;
683 		pads[0].flags = MEDIA_PAD_FL_SINK;
684 		pads[1].flags = MEDIA_PAD_FL_SOURCE;
685 		num_pads = 2;
686 		break;
687 	default:
688 		return -EINVAL;
689 	}
690 
691 	entity->obj_type = MEDIA_ENTITY_TYPE_BASE;
692 	if (type != MEM2MEM_ENT_TYPE_PROC) {
693 		entity->info.dev.major = VIDEO_MAJOR;
694 		entity->info.dev.minor = vdev->minor;
695 	}
696 	len = strlen(vdev->name) + 2 + strlen(m2m_entity_name[type]);
697 	name = kmalloc(len, GFP_KERNEL);
698 	if (!name)
699 		return -ENOMEM;
700 	snprintf(name, len, "%s-%s", vdev->name, m2m_entity_name[type]);
701 	entity->name = name;
702 	entity->function = function;
703 
704 	ret = media_entity_pads_init(entity, num_pads, pads);
705 	if (ret)
706 		return ret;
707 	ret = media_device_register_entity(mdev, entity);
708 	if (ret)
709 		return ret;
710 
711 	return 0;
712 }
713 
714 int v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,
715 		struct video_device *vdev, int function)
716 {
717 	struct media_device *mdev = vdev->v4l2_dev->mdev;
718 	struct media_link *link;
719 	int ret;
720 
721 	if (!mdev)
722 		return 0;
723 
724 	/* A memory-to-memory device consists in two
725 	 * DMA engine and one video processing entities.
726 	 * The DMA engine entities are linked to a V4L interface
727 	 */
728 
729 	/* Create the three entities with their pads */
730 	m2m_dev->source = &vdev->entity;
731 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
732 			MEM2MEM_ENT_TYPE_SOURCE, vdev, MEDIA_ENT_F_IO_V4L);
733 	if (ret)
734 		return ret;
735 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
736 			MEM2MEM_ENT_TYPE_PROC, vdev, function);
737 	if (ret)
738 		goto err_rel_entity0;
739 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
740 			MEM2MEM_ENT_TYPE_SINK, vdev, MEDIA_ENT_F_IO_V4L);
741 	if (ret)
742 		goto err_rel_entity1;
743 
744 	/* Connect the three entities */
745 	ret = media_create_pad_link(m2m_dev->source, 0, &m2m_dev->proc, 1,
746 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
747 	if (ret)
748 		goto err_rel_entity2;
749 
750 	ret = media_create_pad_link(&m2m_dev->proc, 0, &m2m_dev->sink, 0,
751 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
752 	if (ret)
753 		goto err_rm_links0;
754 
755 	/* Create video interface */
756 	m2m_dev->intf_devnode = media_devnode_create(mdev,
757 			MEDIA_INTF_T_V4L_VIDEO, 0,
758 			VIDEO_MAJOR, vdev->minor);
759 	if (!m2m_dev->intf_devnode) {
760 		ret = -ENOMEM;
761 		goto err_rm_links1;
762 	}
763 
764 	/* Connect the two DMA engines to the interface */
765 	link = media_create_intf_link(m2m_dev->source,
766 			&m2m_dev->intf_devnode->intf,
767 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
768 	if (!link) {
769 		ret = -ENOMEM;
770 		goto err_rm_devnode;
771 	}
772 
773 	link = media_create_intf_link(&m2m_dev->sink,
774 			&m2m_dev->intf_devnode->intf,
775 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
776 	if (!link) {
777 		ret = -ENOMEM;
778 		goto err_rm_intf_link;
779 	}
780 	return 0;
781 
782 err_rm_intf_link:
783 	media_remove_intf_links(&m2m_dev->intf_devnode->intf);
784 err_rm_devnode:
785 	media_devnode_remove(m2m_dev->intf_devnode);
786 err_rm_links1:
787 	media_entity_remove_links(&m2m_dev->sink);
788 err_rm_links0:
789 	media_entity_remove_links(&m2m_dev->proc);
790 	media_entity_remove_links(m2m_dev->source);
791 err_rel_entity2:
792 	media_device_unregister_entity(&m2m_dev->proc);
793 	kfree(m2m_dev->proc.name);
794 err_rel_entity1:
795 	media_device_unregister_entity(&m2m_dev->sink);
796 	kfree(m2m_dev->sink.name);
797 err_rel_entity0:
798 	media_device_unregister_entity(m2m_dev->source);
799 	kfree(m2m_dev->source->name);
800 	return ret;
801 	return 0;
802 }
803 EXPORT_SYMBOL_GPL(v4l2_m2m_register_media_controller);
804 #endif
805 
806 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
807 {
808 	struct v4l2_m2m_dev *m2m_dev;
809 
810 	if (!m2m_ops || WARN_ON(!m2m_ops->device_run))
811 		return ERR_PTR(-EINVAL);
812 
813 	m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
814 	if (!m2m_dev)
815 		return ERR_PTR(-ENOMEM);
816 
817 	m2m_dev->curr_ctx = NULL;
818 	m2m_dev->m2m_ops = m2m_ops;
819 	INIT_LIST_HEAD(&m2m_dev->job_queue);
820 	spin_lock_init(&m2m_dev->job_spinlock);
821 
822 	return m2m_dev;
823 }
824 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
825 
826 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
827 {
828 	kfree(m2m_dev);
829 }
830 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
831 
832 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
833 		void *drv_priv,
834 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
835 {
836 	struct v4l2_m2m_ctx *m2m_ctx;
837 	struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
838 	int ret;
839 
840 	m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
841 	if (!m2m_ctx)
842 		return ERR_PTR(-ENOMEM);
843 
844 	m2m_ctx->priv = drv_priv;
845 	m2m_ctx->m2m_dev = m2m_dev;
846 	init_waitqueue_head(&m2m_ctx->finished);
847 
848 	out_q_ctx = &m2m_ctx->out_q_ctx;
849 	cap_q_ctx = &m2m_ctx->cap_q_ctx;
850 
851 	INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
852 	INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
853 	spin_lock_init(&out_q_ctx->rdy_spinlock);
854 	spin_lock_init(&cap_q_ctx->rdy_spinlock);
855 
856 	INIT_LIST_HEAD(&m2m_ctx->queue);
857 
858 	ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
859 
860 	if (ret)
861 		goto err;
862 	/*
863 	 * If both queues use same mutex assign it as the common buffer
864 	 * queues lock to the m2m context. This lock is used in the
865 	 * v4l2_m2m_ioctl_* helpers.
866 	 */
867 	if (out_q_ctx->q.lock == cap_q_ctx->q.lock)
868 		m2m_ctx->q_lock = out_q_ctx->q.lock;
869 
870 	return m2m_ctx;
871 err:
872 	kfree(m2m_ctx);
873 	return ERR_PTR(ret);
874 }
875 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
876 
877 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
878 {
879 	/* wait until the current context is dequeued from job_queue */
880 	v4l2_m2m_cancel_job(m2m_ctx);
881 
882 	vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
883 	vb2_queue_release(&m2m_ctx->out_q_ctx.q);
884 
885 	kfree(m2m_ctx);
886 }
887 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
888 
889 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
890 		struct vb2_v4l2_buffer *vbuf)
891 {
892 	struct v4l2_m2m_buffer *b = container_of(vbuf,
893 				struct v4l2_m2m_buffer, vb);
894 	struct v4l2_m2m_queue_ctx *q_ctx;
895 	unsigned long flags;
896 
897 	q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type);
898 	if (!q_ctx)
899 		return;
900 
901 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
902 	list_add_tail(&b->list, &q_ctx->rdy_queue);
903 	q_ctx->num_rdy++;
904 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
905 }
906 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
907 
908 /* Videobuf2 ioctl helpers */
909 
910 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
911 				struct v4l2_requestbuffers *rb)
912 {
913 	struct v4l2_fh *fh = file->private_data;
914 
915 	return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb);
916 }
917 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_reqbufs);
918 
919 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv,
920 				struct v4l2_create_buffers *create)
921 {
922 	struct v4l2_fh *fh = file->private_data;
923 
924 	return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create);
925 }
926 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs);
927 
928 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
929 				struct v4l2_buffer *buf)
930 {
931 	struct v4l2_fh *fh = file->private_data;
932 
933 	return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf);
934 }
935 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_querybuf);
936 
937 int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv,
938 				struct v4l2_buffer *buf)
939 {
940 	struct v4l2_fh *fh = file->private_data;
941 
942 	return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf);
943 }
944 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_qbuf);
945 
946 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
947 				struct v4l2_buffer *buf)
948 {
949 	struct v4l2_fh *fh = file->private_data;
950 
951 	return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf);
952 }
953 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf);
954 
955 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
956 			       struct v4l2_buffer *buf)
957 {
958 	struct v4l2_fh *fh = file->private_data;
959 
960 	return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
961 }
962 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf);
963 
964 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
965 				struct v4l2_exportbuffer *eb)
966 {
967 	struct v4l2_fh *fh = file->private_data;
968 
969 	return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb);
970 }
971 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_expbuf);
972 
973 int v4l2_m2m_ioctl_streamon(struct file *file, void *priv,
974 				enum v4l2_buf_type type)
975 {
976 	struct v4l2_fh *fh = file->private_data;
977 
978 	return v4l2_m2m_streamon(file, fh->m2m_ctx, type);
979 }
980 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamon);
981 
982 int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv,
983 				enum v4l2_buf_type type)
984 {
985 	struct v4l2_fh *fh = file->private_data;
986 
987 	return v4l2_m2m_streamoff(file, fh->m2m_ctx, type);
988 }
989 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamoff);
990 
991 /*
992  * v4l2_file_operations helpers. It is assumed here same lock is used
993  * for the output and the capture buffer queue.
994  */
995 
996 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma)
997 {
998 	struct v4l2_fh *fh = file->private_data;
999 
1000 	return v4l2_m2m_mmap(file, fh->m2m_ctx, vma);
1001 }
1002 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_mmap);
1003 
1004 __poll_t v4l2_m2m_fop_poll(struct file *file, poll_table *wait)
1005 {
1006 	struct v4l2_fh *fh = file->private_data;
1007 	struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx;
1008 	__poll_t ret;
1009 
1010 	if (m2m_ctx->q_lock)
1011 		mutex_lock(m2m_ctx->q_lock);
1012 
1013 	ret = v4l2_m2m_poll(file, m2m_ctx, wait);
1014 
1015 	if (m2m_ctx->q_lock)
1016 		mutex_unlock(m2m_ctx->q_lock);
1017 
1018 	return ret;
1019 }
1020 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_poll);
1021 
1022