1 /*
2  * videobuf2-v4l2.c - V4L2 driver helper framework
3  *
4  * Copyright (C) 2010 Samsung Electronics
5  *
6  * Author: Pawel Osciak <pawel@osciak.com>
7  *	   Marek Szyprowski <m.szyprowski@samsung.com>
8  *
9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
10  *	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation.
15  */
16 
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/freezer.h>
20 #include <linux/kernel.h>
21 #include <linux/kthread.h>
22 #include <linux/mm.h>
23 #include <linux/module.h>
24 #include <linux/poll.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 
28 #include <media/v4l2-common.h>
29 #include <media/v4l2-dev.h>
30 #include <media/v4l2-device.h>
31 #include <media/v4l2-event.h>
32 #include <media/v4l2-fh.h>
33 
34 #include <media/videobuf2-v4l2.h>
35 
36 static int debug;
37 module_param(debug, int, 0644);
38 
39 #define dprintk(q, level, fmt, arg...)					      \
40 	do {								      \
41 		if (debug >= level)					      \
42 			pr_info("vb2-v4l2: [%p] %s: " fmt,		      \
43 				(q)->name, __func__, ## arg);		      \
44 	} while (0)
45 
46 /* Flags that are set by us */
47 #define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
48 				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
49 				 V4L2_BUF_FLAG_PREPARED | \
50 				 V4L2_BUF_FLAG_IN_REQUEST | \
51 				 V4L2_BUF_FLAG_REQUEST_FD | \
52 				 V4L2_BUF_FLAG_TIMESTAMP_MASK)
53 /* Output buffer flags that should be passed on to the driver */
54 #define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | \
55 				 V4L2_BUF_FLAG_BFRAME | \
56 				 V4L2_BUF_FLAG_KEYFRAME | \
57 				 V4L2_BUF_FLAG_TIMECODE | \
58 				 V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)
59 
60 /*
61  * __verify_planes_array() - verify that the planes array passed in struct
62  * v4l2_buffer from userspace can be safely used
63  */
64 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
65 {
66 	if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
67 		return 0;
68 
69 	/* Is memory for copying plane information present? */
70 	if (b->m.planes == NULL) {
71 		dprintk(vb->vb2_queue, 1,
72 			"multi-planar buffer passed but planes array not provided\n");
73 		return -EINVAL;
74 	}
75 
76 	if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
77 		dprintk(vb->vb2_queue, 1,
78 			"incorrect planes array length, expected %d, got %d\n",
79 			vb->num_planes, b->length);
80 		return -EINVAL;
81 	}
82 
83 	return 0;
84 }
85 
86 static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
87 {
88 	return __verify_planes_array(vb, pb);
89 }
90 
91 /*
92  * __verify_length() - Verify that the bytesused value for each plane fits in
93  * the plane length and that the data offset doesn't exceed the bytesused value.
94  */
95 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
96 {
97 	unsigned int length;
98 	unsigned int bytesused;
99 	unsigned int plane;
100 
101 	if (V4L2_TYPE_IS_CAPTURE(b->type))
102 		return 0;
103 
104 	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
105 		for (plane = 0; plane < vb->num_planes; ++plane) {
106 			length = (b->memory == VB2_MEMORY_USERPTR ||
107 				  b->memory == VB2_MEMORY_DMABUF)
108 			       ? b->m.planes[plane].length
109 				: vb->planes[plane].length;
110 			bytesused = b->m.planes[plane].bytesused
111 				  ? b->m.planes[plane].bytesused : length;
112 
113 			if (b->m.planes[plane].bytesused > length)
114 				return -EINVAL;
115 
116 			if (b->m.planes[plane].data_offset > 0 &&
117 			    b->m.planes[plane].data_offset >= bytesused)
118 				return -EINVAL;
119 		}
120 	} else {
121 		length = (b->memory == VB2_MEMORY_USERPTR)
122 			? b->length : vb->planes[0].length;
123 
124 		if (b->bytesused > length)
125 			return -EINVAL;
126 	}
127 
128 	return 0;
129 }
130 
131 /*
132  * __init_vb2_v4l2_buffer() - initialize the vb2_v4l2_buffer struct
133  */
134 static void __init_vb2_v4l2_buffer(struct vb2_buffer *vb)
135 {
136 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
137 
138 	vbuf->request_fd = -1;
139 }
140 
141 static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
142 {
143 	const struct v4l2_buffer *b = pb;
144 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
145 	struct vb2_queue *q = vb->vb2_queue;
146 
147 	if (q->is_output) {
148 		/*
149 		 * For output buffers copy the timestamp if needed,
150 		 * and the timecode field and flag if needed.
151 		 */
152 		if (q->copy_timestamp)
153 			vb->timestamp = v4l2_buffer_get_timestamp(b);
154 		vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
155 		if (b->flags & V4L2_BUF_FLAG_TIMECODE)
156 			vbuf->timecode = b->timecode;
157 	}
158 };
159 
160 static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
161 {
162 	static bool check_once;
163 
164 	if (check_once)
165 		return;
166 
167 	check_once = true;
168 
169 	pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
170 	if (vb->vb2_queue->allow_zero_bytesused)
171 		pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
172 	else
173 		pr_warn("use the actual size instead.\n");
174 }
175 
176 static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
177 {
178 	struct vb2_queue *q = vb->vb2_queue;
179 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
180 	struct vb2_plane *planes = vbuf->planes;
181 	unsigned int plane;
182 	int ret;
183 
184 	ret = __verify_length(vb, b);
185 	if (ret < 0) {
186 		dprintk(q, 1, "plane parameters verification failed: %d\n", ret);
187 		return ret;
188 	}
189 	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
190 		/*
191 		 * If the format's field is ALTERNATE, then the buffer's field
192 		 * should be either TOP or BOTTOM, not ALTERNATE since that
193 		 * makes no sense. The driver has to know whether the
194 		 * buffer represents a top or a bottom field in order to
195 		 * program any DMA correctly. Using ALTERNATE is wrong, since
196 		 * that just says that it is either a top or a bottom field,
197 		 * but not which of the two it is.
198 		 */
199 		dprintk(q, 1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
200 		return -EINVAL;
201 	}
202 	vbuf->sequence = 0;
203 	vbuf->request_fd = -1;
204 	vbuf->is_held = false;
205 
206 	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
207 		switch (b->memory) {
208 		case VB2_MEMORY_USERPTR:
209 			for (plane = 0; plane < vb->num_planes; ++plane) {
210 				planes[plane].m.userptr =
211 					b->m.planes[plane].m.userptr;
212 				planes[plane].length =
213 					b->m.planes[plane].length;
214 			}
215 			break;
216 		case VB2_MEMORY_DMABUF:
217 			for (plane = 0; plane < vb->num_planes; ++plane) {
218 				planes[plane].m.fd =
219 					b->m.planes[plane].m.fd;
220 				planes[plane].length =
221 					b->m.planes[plane].length;
222 			}
223 			break;
224 		default:
225 			for (plane = 0; plane < vb->num_planes; ++plane) {
226 				planes[plane].m.offset =
227 					vb->planes[plane].m.offset;
228 				planes[plane].length =
229 					vb->planes[plane].length;
230 			}
231 			break;
232 		}
233 
234 		/* Fill in driver-provided information for OUTPUT types */
235 		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
236 			/*
237 			 * Will have to go up to b->length when API starts
238 			 * accepting variable number of planes.
239 			 *
240 			 * If bytesused == 0 for the output buffer, then fall
241 			 * back to the full buffer size. In that case
242 			 * userspace clearly never bothered to set it and
243 			 * it's a safe assumption that they really meant to
244 			 * use the full plane sizes.
245 			 *
246 			 * Some drivers, e.g. old codec drivers, use bytesused == 0
247 			 * as a way to indicate that streaming is finished.
248 			 * In that case, the driver should use the
249 			 * allow_zero_bytesused flag to keep old userspace
250 			 * applications working.
251 			 */
252 			for (plane = 0; plane < vb->num_planes; ++plane) {
253 				struct vb2_plane *pdst = &planes[plane];
254 				struct v4l2_plane *psrc = &b->m.planes[plane];
255 
256 				if (psrc->bytesused == 0)
257 					vb2_warn_zero_bytesused(vb);
258 
259 				if (vb->vb2_queue->allow_zero_bytesused)
260 					pdst->bytesused = psrc->bytesused;
261 				else
262 					pdst->bytesused = psrc->bytesused ?
263 						psrc->bytesused : pdst->length;
264 				pdst->data_offset = psrc->data_offset;
265 			}
266 		}
267 	} else {
268 		/*
269 		 * Single-planar buffers do not use planes array,
270 		 * so fill in relevant v4l2_buffer struct fields instead.
271 		 * In videobuf we use our internal V4l2_planes struct for
272 		 * single-planar buffers as well, for simplicity.
273 		 *
274 		 * If bytesused == 0 for the output buffer, then fall back
275 		 * to the full buffer size as that's a sensible default.
276 		 *
277 		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
278 		 * a way to indicate that streaming is finished. In that case,
279 		 * the driver should use the allow_zero_bytesused flag to keep
280 		 * old userspace applications working.
281 		 */
282 		switch (b->memory) {
283 		case VB2_MEMORY_USERPTR:
284 			planes[0].m.userptr = b->m.userptr;
285 			planes[0].length = b->length;
286 			break;
287 		case VB2_MEMORY_DMABUF:
288 			planes[0].m.fd = b->m.fd;
289 			planes[0].length = b->length;
290 			break;
291 		default:
292 			planes[0].m.offset = vb->planes[0].m.offset;
293 			planes[0].length = vb->planes[0].length;
294 			break;
295 		}
296 
297 		planes[0].data_offset = 0;
298 		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
299 			if (b->bytesused == 0)
300 				vb2_warn_zero_bytesused(vb);
301 
302 			if (vb->vb2_queue->allow_zero_bytesused)
303 				planes[0].bytesused = b->bytesused;
304 			else
305 				planes[0].bytesused = b->bytesused ?
306 					b->bytesused : planes[0].length;
307 		} else
308 			planes[0].bytesused = 0;
309 
310 	}
311 
312 	/* Zero flags that we handle */
313 	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
314 	if (!vb->vb2_queue->copy_timestamp || V4L2_TYPE_IS_CAPTURE(b->type)) {
315 		/*
316 		 * Non-COPY timestamps and non-OUTPUT queues will get
317 		 * their timestamp and timestamp source flags from the
318 		 * queue.
319 		 */
320 		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
321 	}
322 
323 	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
324 		/*
325 		 * For output buffers mask out the timecode flag:
326 		 * this will be handled later in vb2_qbuf().
327 		 * The 'field' is valid metadata for this output buffer
328 		 * and so that needs to be copied here.
329 		 */
330 		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
331 		vbuf->field = b->field;
332 		if (!(q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF))
333 			vbuf->flags &= ~V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;
334 	} else {
335 		/* Zero any output buffer flags as this is a capture buffer */
336 		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
337 		/* Zero last flag, this is a signal from driver to userspace */
338 		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
339 	}
340 
341 	return 0;
342 }
343 
344 static void set_buffer_cache_hints(struct vb2_queue *q,
345 				   struct vb2_buffer *vb,
346 				   struct v4l2_buffer *b)
347 {
348 	/*
349 	 * DMA exporter should take care of cache syncs, so we can avoid
350 	 * explicit ->prepare()/->finish() syncs. For other ->memory types
351 	 * we always need ->prepare() or/and ->finish() cache sync.
352 	 */
353 	if (q->memory == VB2_MEMORY_DMABUF) {
354 		vb->need_cache_sync_on_finish = 0;
355 		vb->need_cache_sync_on_prepare = 0;
356 		return;
357 	}
358 
359 	/*
360 	 * Cache sync/invalidation flags are set by default in order to
361 	 * preserve existing behaviour for old apps/drivers.
362 	 */
363 	vb->need_cache_sync_on_prepare = 1;
364 	vb->need_cache_sync_on_finish = 1;
365 
366 	if (!vb2_queue_allows_cache_hints(q)) {
367 		/*
368 		 * Clear buffer cache flags if queue does not support user
369 		 * space hints. That's to indicate to userspace that these
370 		 * flags won't work.
371 		 */
372 		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;
373 		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;
374 		return;
375 	}
376 
377 	/*
378 	 * ->finish() cache sync can be avoided when queue direction is
379 	 * TO_DEVICE.
380 	 */
381 	if (q->dma_dir == DMA_TO_DEVICE)
382 		vb->need_cache_sync_on_finish = 0;
383 
384 	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
385 		vb->need_cache_sync_on_finish = 0;
386 
387 	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
388 		vb->need_cache_sync_on_prepare = 0;
389 }
390 
391 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
392 				    struct v4l2_buffer *b, bool is_prepare,
393 				    struct media_request **p_req)
394 {
395 	const char *opname = is_prepare ? "prepare_buf" : "qbuf";
396 	struct media_request *req;
397 	struct vb2_v4l2_buffer *vbuf;
398 	struct vb2_buffer *vb;
399 	int ret;
400 
401 	if (b->type != q->type) {
402 		dprintk(q, 1, "%s: invalid buffer type\n", opname);
403 		return -EINVAL;
404 	}
405 
406 	if (b->index >= q->num_buffers) {
407 		dprintk(q, 1, "%s: buffer index out of range\n", opname);
408 		return -EINVAL;
409 	}
410 
411 	if (q->bufs[b->index] == NULL) {
412 		/* Should never happen */
413 		dprintk(q, 1, "%s: buffer is NULL\n", opname);
414 		return -EINVAL;
415 	}
416 
417 	if (b->memory != q->memory) {
418 		dprintk(q, 1, "%s: invalid memory type\n", opname);
419 		return -EINVAL;
420 	}
421 
422 	vb = q->bufs[b->index];
423 	vbuf = to_vb2_v4l2_buffer(vb);
424 	ret = __verify_planes_array(vb, b);
425 	if (ret)
426 		return ret;
427 
428 	if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&
429 	    vb->state != VB2_BUF_STATE_DEQUEUED) {
430 		dprintk(q, 1, "%s: buffer is not in dequeued state\n", opname);
431 		return -EINVAL;
432 	}
433 
434 	if (!vb->prepared) {
435 		set_buffer_cache_hints(q, vb, b);
436 		/* Copy relevant information provided by the userspace */
437 		memset(vbuf->planes, 0,
438 		       sizeof(vbuf->planes[0]) * vb->num_planes);
439 		ret = vb2_fill_vb2_v4l2_buffer(vb, b);
440 		if (ret)
441 			return ret;
442 	}
443 
444 	if (is_prepare)
445 		return 0;
446 
447 	if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
448 		if (q->requires_requests) {
449 			dprintk(q, 1, "%s: queue requires requests\n", opname);
450 			return -EBADR;
451 		}
452 		if (q->uses_requests) {
453 			dprintk(q, 1, "%s: queue uses requests\n", opname);
454 			return -EBUSY;
455 		}
456 		return 0;
457 	} else if (!q->supports_requests) {
458 		dprintk(q, 1, "%s: queue does not support requests\n", opname);
459 		return -EBADR;
460 	} else if (q->uses_qbuf) {
461 		dprintk(q, 1, "%s: queue does not use requests\n", opname);
462 		return -EBUSY;
463 	}
464 
465 	/*
466 	 * For proper locking when queueing a request you need to be able
467 	 * to lock access to the vb2 queue, so check that there is a lock
468 	 * that we can use. In addition p_req must be non-NULL.
469 	 */
470 	if (WARN_ON(!q->lock || !p_req))
471 		return -EINVAL;
472 
473 	/*
474 	 * Make sure this op is implemented by the driver. It's easy to forget
475 	 * this callback, but is it important when canceling a buffer in a
476 	 * queued request.
477 	 */
478 	if (WARN_ON(!q->ops->buf_request_complete))
479 		return -EINVAL;
480 	/*
481 	 * Make sure this op is implemented by the driver for the output queue.
482 	 * It's easy to forget this callback, but is it important to correctly
483 	 * validate the 'field' value at QBUF time.
484 	 */
485 	if (WARN_ON((q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||
486 		     q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) &&
487 		    !q->ops->buf_out_validate))
488 		return -EINVAL;
489 
490 	req = media_request_get_by_fd(mdev, b->request_fd);
491 	if (IS_ERR(req)) {
492 		dprintk(q, 1, "%s: invalid request_fd\n", opname);
493 		return PTR_ERR(req);
494 	}
495 
496 	/*
497 	 * Early sanity check. This is checked again when the buffer
498 	 * is bound to the request in vb2_core_qbuf().
499 	 */
500 	if (req->state != MEDIA_REQUEST_STATE_IDLE &&
501 	    req->state != MEDIA_REQUEST_STATE_UPDATING) {
502 		dprintk(q, 1, "%s: request is not idle\n", opname);
503 		media_request_put(req);
504 		return -EBUSY;
505 	}
506 
507 	*p_req = req;
508 	vbuf->request_fd = b->request_fd;
509 
510 	return 0;
511 }
512 
513 /*
514  * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
515  * returned to userspace
516  */
517 static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
518 {
519 	struct v4l2_buffer *b = pb;
520 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
521 	struct vb2_queue *q = vb->vb2_queue;
522 	unsigned int plane;
523 
524 	/* Copy back data such as timestamp, flags, etc. */
525 	b->index = vb->index;
526 	b->type = vb->type;
527 	b->memory = vb->memory;
528 	b->bytesused = 0;
529 
530 	b->flags = vbuf->flags;
531 	b->field = vbuf->field;
532 	v4l2_buffer_set_timestamp(b, vb->timestamp);
533 	b->timecode = vbuf->timecode;
534 	b->sequence = vbuf->sequence;
535 	b->reserved2 = 0;
536 	b->request_fd = 0;
537 
538 	if (q->is_multiplanar) {
539 		/*
540 		 * Fill in plane-related data if userspace provided an array
541 		 * for it. The caller has already verified memory and size.
542 		 */
543 		b->length = vb->num_planes;
544 		for (plane = 0; plane < vb->num_planes; ++plane) {
545 			struct v4l2_plane *pdst = &b->m.planes[plane];
546 			struct vb2_plane *psrc = &vb->planes[plane];
547 
548 			pdst->bytesused = psrc->bytesused;
549 			pdst->length = psrc->length;
550 			if (q->memory == VB2_MEMORY_MMAP)
551 				pdst->m.mem_offset = psrc->m.offset;
552 			else if (q->memory == VB2_MEMORY_USERPTR)
553 				pdst->m.userptr = psrc->m.userptr;
554 			else if (q->memory == VB2_MEMORY_DMABUF)
555 				pdst->m.fd = psrc->m.fd;
556 			pdst->data_offset = psrc->data_offset;
557 			memset(pdst->reserved, 0, sizeof(pdst->reserved));
558 		}
559 	} else {
560 		/*
561 		 * We use length and offset in v4l2_planes array even for
562 		 * single-planar buffers, but userspace does not.
563 		 */
564 		b->length = vb->planes[0].length;
565 		b->bytesused = vb->planes[0].bytesused;
566 		if (q->memory == VB2_MEMORY_MMAP)
567 			b->m.offset = vb->planes[0].m.offset;
568 		else if (q->memory == VB2_MEMORY_USERPTR)
569 			b->m.userptr = vb->planes[0].m.userptr;
570 		else if (q->memory == VB2_MEMORY_DMABUF)
571 			b->m.fd = vb->planes[0].m.fd;
572 	}
573 
574 	/*
575 	 * Clear any buffer state related flags.
576 	 */
577 	b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
578 	b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
579 	if (!q->copy_timestamp) {
580 		/*
581 		 * For non-COPY timestamps, drop timestamp source bits
582 		 * and obtain the timestamp source from the queue.
583 		 */
584 		b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
585 		b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
586 	}
587 
588 	switch (vb->state) {
589 	case VB2_BUF_STATE_QUEUED:
590 	case VB2_BUF_STATE_ACTIVE:
591 		b->flags |= V4L2_BUF_FLAG_QUEUED;
592 		break;
593 	case VB2_BUF_STATE_IN_REQUEST:
594 		b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
595 		break;
596 	case VB2_BUF_STATE_ERROR:
597 		b->flags |= V4L2_BUF_FLAG_ERROR;
598 		fallthrough;
599 	case VB2_BUF_STATE_DONE:
600 		b->flags |= V4L2_BUF_FLAG_DONE;
601 		break;
602 	case VB2_BUF_STATE_PREPARING:
603 	case VB2_BUF_STATE_DEQUEUED:
604 		/* nothing */
605 		break;
606 	}
607 
608 	if ((vb->state == VB2_BUF_STATE_DEQUEUED ||
609 	     vb->state == VB2_BUF_STATE_IN_REQUEST) &&
610 	    vb->synced && vb->prepared)
611 		b->flags |= V4L2_BUF_FLAG_PREPARED;
612 
613 	if (vb2_buffer_in_use(q, vb))
614 		b->flags |= V4L2_BUF_FLAG_MAPPED;
615 	if (vbuf->request_fd >= 0) {
616 		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
617 		b->request_fd = vbuf->request_fd;
618 	}
619 }
620 
621 /*
622  * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
623  * v4l2_buffer by the userspace. It also verifies that struct
624  * v4l2_buffer has a valid number of planes.
625  */
626 static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
627 {
628 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
629 	unsigned int plane;
630 
631 	if (!vb->vb2_queue->copy_timestamp)
632 		vb->timestamp = 0;
633 
634 	for (plane = 0; plane < vb->num_planes; ++plane) {
635 		if (vb->vb2_queue->memory != VB2_MEMORY_MMAP) {
636 			planes[plane].m = vbuf->planes[plane].m;
637 			planes[plane].length = vbuf->planes[plane].length;
638 		}
639 		planes[plane].bytesused = vbuf->planes[plane].bytesused;
640 		planes[plane].data_offset = vbuf->planes[plane].data_offset;
641 	}
642 	return 0;
643 }
644 
645 static const struct vb2_buf_ops v4l2_buf_ops = {
646 	.verify_planes_array	= __verify_planes_array_core,
647 	.init_buffer		= __init_vb2_v4l2_buffer,
648 	.fill_user_buffer	= __fill_v4l2_buffer,
649 	.fill_vb2_buffer	= __fill_vb2_buffer,
650 	.copy_timestamp		= __copy_timestamp,
651 };
652 
653 int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
654 		       unsigned int start_idx)
655 {
656 	unsigned int i;
657 
658 	for (i = start_idx; i < q->num_buffers; i++)
659 		if (q->bufs[i]->copied_timestamp &&
660 		    q->bufs[i]->timestamp == timestamp)
661 			return i;
662 	return -1;
663 }
664 EXPORT_SYMBOL_GPL(vb2_find_timestamp);
665 
666 /*
667  * vb2_querybuf() - query video buffer information
668  * @q:		videobuf queue
669  * @b:		buffer struct passed from userspace to vidioc_querybuf handler
670  *		in driver
671  *
672  * Should be called from vidioc_querybuf ioctl handler in driver.
673  * This function will verify the passed v4l2_buffer structure and fill the
674  * relevant information for the userspace.
675  *
676  * The return values from this function are intended to be directly returned
677  * from vidioc_querybuf handler in driver.
678  */
679 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
680 {
681 	struct vb2_buffer *vb;
682 	int ret;
683 
684 	if (b->type != q->type) {
685 		dprintk(q, 1, "wrong buffer type\n");
686 		return -EINVAL;
687 	}
688 
689 	if (b->index >= q->num_buffers) {
690 		dprintk(q, 1, "buffer index out of range\n");
691 		return -EINVAL;
692 	}
693 	vb = q->bufs[b->index];
694 	ret = __verify_planes_array(vb, b);
695 	if (!ret)
696 		vb2_core_querybuf(q, b->index, b);
697 	return ret;
698 }
699 EXPORT_SYMBOL(vb2_querybuf);
700 
701 static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
702 {
703 	*caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
704 	if (q->io_modes & VB2_MMAP)
705 		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP;
706 	if (q->io_modes & VB2_USERPTR)
707 		*caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;
708 	if (q->io_modes & VB2_DMABUF)
709 		*caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
710 	if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)
711 		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
712 	if (q->allow_cache_hints && q->io_modes & VB2_MMAP)
713 		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
714 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
715 	if (q->supports_requests)
716 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
717 #endif
718 }
719 
720 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
721 {
722 	int ret = vb2_verify_memory_type(q, req->memory, req->type);
723 
724 	fill_buf_caps(q, &req->capabilities);
725 	return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count);
726 }
727 EXPORT_SYMBOL_GPL(vb2_reqbufs);
728 
729 int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
730 		    struct v4l2_buffer *b)
731 {
732 	int ret;
733 
734 	if (vb2_fileio_is_active(q)) {
735 		dprintk(q, 1, "file io in progress\n");
736 		return -EBUSY;
737 	}
738 
739 	if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)
740 		return -EINVAL;
741 
742 	ret = vb2_queue_or_prepare_buf(q, mdev, b, true, NULL);
743 
744 	return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
745 }
746 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
747 
748 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
749 {
750 	unsigned requested_planes = 1;
751 	unsigned requested_sizes[VIDEO_MAX_PLANES];
752 	struct v4l2_format *f = &create->format;
753 	int ret = vb2_verify_memory_type(q, create->memory, f->type);
754 	unsigned i;
755 
756 	fill_buf_caps(q, &create->capabilities);
757 	create->index = q->num_buffers;
758 	if (create->count == 0)
759 		return ret != -EBUSY ? ret : 0;
760 
761 	switch (f->type) {
762 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
763 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
764 		requested_planes = f->fmt.pix_mp.num_planes;
765 		if (requested_planes == 0 ||
766 		    requested_planes > VIDEO_MAX_PLANES)
767 			return -EINVAL;
768 		for (i = 0; i < requested_planes; i++)
769 			requested_sizes[i] =
770 				f->fmt.pix_mp.plane_fmt[i].sizeimage;
771 		break;
772 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
773 	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
774 		requested_sizes[0] = f->fmt.pix.sizeimage;
775 		break;
776 	case V4L2_BUF_TYPE_VBI_CAPTURE:
777 	case V4L2_BUF_TYPE_VBI_OUTPUT:
778 		requested_sizes[0] = f->fmt.vbi.samples_per_line *
779 			(f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);
780 		break;
781 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
782 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
783 		requested_sizes[0] = f->fmt.sliced.io_size;
784 		break;
785 	case V4L2_BUF_TYPE_SDR_CAPTURE:
786 	case V4L2_BUF_TYPE_SDR_OUTPUT:
787 		requested_sizes[0] = f->fmt.sdr.buffersize;
788 		break;
789 	case V4L2_BUF_TYPE_META_CAPTURE:
790 	case V4L2_BUF_TYPE_META_OUTPUT:
791 		requested_sizes[0] = f->fmt.meta.buffersize;
792 		break;
793 	default:
794 		return -EINVAL;
795 	}
796 	for (i = 0; i < requested_planes; i++)
797 		if (requested_sizes[i] == 0)
798 			return -EINVAL;
799 	return ret ? ret : vb2_core_create_bufs(q, create->memory,
800 						&create->count,
801 						requested_planes,
802 						requested_sizes);
803 }
804 EXPORT_SYMBOL_GPL(vb2_create_bufs);
805 
806 int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
807 	     struct v4l2_buffer *b)
808 {
809 	struct media_request *req = NULL;
810 	int ret;
811 
812 	if (vb2_fileio_is_active(q)) {
813 		dprintk(q, 1, "file io in progress\n");
814 		return -EBUSY;
815 	}
816 
817 	ret = vb2_queue_or_prepare_buf(q, mdev, b, false, &req);
818 	if (ret)
819 		return ret;
820 	ret = vb2_core_qbuf(q, b->index, b, req);
821 	if (req)
822 		media_request_put(req);
823 	return ret;
824 }
825 EXPORT_SYMBOL_GPL(vb2_qbuf);
826 
827 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
828 {
829 	int ret;
830 
831 	if (vb2_fileio_is_active(q)) {
832 		dprintk(q, 1, "file io in progress\n");
833 		return -EBUSY;
834 	}
835 
836 	if (b->type != q->type) {
837 		dprintk(q, 1, "invalid buffer type\n");
838 		return -EINVAL;
839 	}
840 
841 	ret = vb2_core_dqbuf(q, NULL, b, nonblocking);
842 
843 	if (!q->is_output &&
844 	    b->flags & V4L2_BUF_FLAG_DONE &&
845 	    b->flags & V4L2_BUF_FLAG_LAST)
846 		q->last_buffer_dequeued = true;
847 
848 	/*
849 	 *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
850 	 *  cleared.
851 	 */
852 	b->flags &= ~V4L2_BUF_FLAG_DONE;
853 
854 	return ret;
855 }
856 EXPORT_SYMBOL_GPL(vb2_dqbuf);
857 
858 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
859 {
860 	if (vb2_fileio_is_active(q)) {
861 		dprintk(q, 1, "file io in progress\n");
862 		return -EBUSY;
863 	}
864 	return vb2_core_streamon(q, type);
865 }
866 EXPORT_SYMBOL_GPL(vb2_streamon);
867 
868 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
869 {
870 	if (vb2_fileio_is_active(q)) {
871 		dprintk(q, 1, "file io in progress\n");
872 		return -EBUSY;
873 	}
874 	return vb2_core_streamoff(q, type);
875 }
876 EXPORT_SYMBOL_GPL(vb2_streamoff);
877 
878 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
879 {
880 	return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index,
881 				eb->plane, eb->flags);
882 }
883 EXPORT_SYMBOL_GPL(vb2_expbuf);
884 
885 int vb2_queue_init_name(struct vb2_queue *q, const char *name)
886 {
887 	/*
888 	 * Sanity check
889 	 */
890 	if (WARN_ON(!q)			  ||
891 	    WARN_ON(q->timestamp_flags &
892 		    ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
893 		      V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
894 		return -EINVAL;
895 
896 	/* Warn that the driver should choose an appropriate timestamp type */
897 	WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
898 		V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
899 
900 	/* Warn that vb2_memory should match with v4l2_memory */
901 	if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
902 		|| WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
903 		|| WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
904 		return -EINVAL;
905 
906 	if (q->buf_struct_size == 0)
907 		q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
908 
909 	q->buf_ops = &v4l2_buf_ops;
910 	q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
911 	q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
912 	q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
913 			== V4L2_BUF_FLAG_TIMESTAMP_COPY;
914 	/*
915 	 * For compatibility with vb1: if QBUF hasn't been called yet, then
916 	 * return EPOLLERR as well. This only affects capture queues, output
917 	 * queues will always initialize waiting_for_buffers to false.
918 	 */
919 	q->quirk_poll_must_check_waiting_for_buffers = true;
920 
921 	if (name)
922 		strscpy(q->name, name, sizeof(q->name));
923 	else
924 		q->name[0] = '\0';
925 
926 	return vb2_core_queue_init(q);
927 }
928 EXPORT_SYMBOL_GPL(vb2_queue_init_name);
929 
930 int vb2_queue_init(struct vb2_queue *q)
931 {
932 	return vb2_queue_init_name(q, NULL);
933 }
934 EXPORT_SYMBOL_GPL(vb2_queue_init);
935 
936 void vb2_queue_release(struct vb2_queue *q)
937 {
938 	vb2_core_queue_release(q);
939 }
940 EXPORT_SYMBOL_GPL(vb2_queue_release);
941 
942 int vb2_queue_change_type(struct vb2_queue *q, unsigned int type)
943 {
944 	if (type == q->type)
945 		return 0;
946 
947 	if (vb2_is_busy(q))
948 		return -EBUSY;
949 
950 	q->type = type;
951 
952 	return 0;
953 }
954 EXPORT_SYMBOL_GPL(vb2_queue_change_type);
955 
956 __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
957 {
958 	struct video_device *vfd = video_devdata(file);
959 	__poll_t res;
960 
961 	res = vb2_core_poll(q, file, wait);
962 
963 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
964 		struct v4l2_fh *fh = file->private_data;
965 
966 		poll_wait(file, &fh->wait, wait);
967 		if (v4l2_event_pending(fh))
968 			res |= EPOLLPRI;
969 	}
970 
971 	return res;
972 }
973 EXPORT_SYMBOL_GPL(vb2_poll);
974 
975 /*
976  * The following functions are not part of the vb2 core API, but are helper
977  * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
978  * and struct vb2_ops.
979  * They contain boilerplate code that most if not all drivers have to do
980  * and so they simplify the driver code.
981  */
982 
983 /* The queue is busy if there is a owner and you are not that owner. */
984 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
985 {
986 	return vdev->queue->owner && vdev->queue->owner != file->private_data;
987 }
988 
989 /* vb2 ioctl helpers */
990 
991 int vb2_ioctl_reqbufs(struct file *file, void *priv,
992 			  struct v4l2_requestbuffers *p)
993 {
994 	struct video_device *vdev = video_devdata(file);
995 	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
996 
997 	fill_buf_caps(vdev->queue, &p->capabilities);
998 	if (res)
999 		return res;
1000 	if (vb2_queue_is_busy(vdev, file))
1001 		return -EBUSY;
1002 	res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count);
1003 	/* If count == 0, then the owner has released all buffers and he
1004 	   is no longer owner of the queue. Otherwise we have a new owner. */
1005 	if (res == 0)
1006 		vdev->queue->owner = p->count ? file->private_data : NULL;
1007 	return res;
1008 }
1009 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
1010 
1011 int vb2_ioctl_create_bufs(struct file *file, void *priv,
1012 			  struct v4l2_create_buffers *p)
1013 {
1014 	struct video_device *vdev = video_devdata(file);
1015 	int res = vb2_verify_memory_type(vdev->queue, p->memory,
1016 			p->format.type);
1017 
1018 	p->index = vdev->queue->num_buffers;
1019 	fill_buf_caps(vdev->queue, &p->capabilities);
1020 	/*
1021 	 * If count == 0, then just check if memory and type are valid.
1022 	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
1023 	 */
1024 	if (p->count == 0)
1025 		return res != -EBUSY ? res : 0;
1026 	if (res)
1027 		return res;
1028 	if (vb2_queue_is_busy(vdev, file))
1029 		return -EBUSY;
1030 
1031 	res = vb2_create_bufs(vdev->queue, p);
1032 	if (res == 0)
1033 		vdev->queue->owner = file->private_data;
1034 	return res;
1035 }
1036 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
1037 
1038 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
1039 			  struct v4l2_buffer *p)
1040 {
1041 	struct video_device *vdev = video_devdata(file);
1042 
1043 	if (vb2_queue_is_busy(vdev, file))
1044 		return -EBUSY;
1045 	return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
1046 }
1047 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
1048 
1049 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
1050 {
1051 	struct video_device *vdev = video_devdata(file);
1052 
1053 	/* No need to call vb2_queue_is_busy(), anyone can query buffers. */
1054 	return vb2_querybuf(vdev->queue, p);
1055 }
1056 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
1057 
1058 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1059 {
1060 	struct video_device *vdev = video_devdata(file);
1061 
1062 	if (vb2_queue_is_busy(vdev, file))
1063 		return -EBUSY;
1064 	return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
1065 }
1066 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
1067 
1068 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1069 {
1070 	struct video_device *vdev = video_devdata(file);
1071 
1072 	if (vb2_queue_is_busy(vdev, file))
1073 		return -EBUSY;
1074 	return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
1075 }
1076 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
1077 
1078 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
1079 {
1080 	struct video_device *vdev = video_devdata(file);
1081 
1082 	if (vb2_queue_is_busy(vdev, file))
1083 		return -EBUSY;
1084 	return vb2_streamon(vdev->queue, i);
1085 }
1086 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
1087 
1088 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
1089 {
1090 	struct video_device *vdev = video_devdata(file);
1091 
1092 	if (vb2_queue_is_busy(vdev, file))
1093 		return -EBUSY;
1094 	return vb2_streamoff(vdev->queue, i);
1095 }
1096 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
1097 
1098 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
1099 {
1100 	struct video_device *vdev = video_devdata(file);
1101 
1102 	if (vb2_queue_is_busy(vdev, file))
1103 		return -EBUSY;
1104 	return vb2_expbuf(vdev->queue, p);
1105 }
1106 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
1107 
1108 /* v4l2_file_operations helpers */
1109 
1110 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
1111 {
1112 	struct video_device *vdev = video_devdata(file);
1113 
1114 	return vb2_mmap(vdev->queue, vma);
1115 }
1116 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
1117 
1118 int _vb2_fop_release(struct file *file, struct mutex *lock)
1119 {
1120 	struct video_device *vdev = video_devdata(file);
1121 
1122 	if (lock)
1123 		mutex_lock(lock);
1124 	if (file->private_data == vdev->queue->owner) {
1125 		vb2_queue_release(vdev->queue);
1126 		vdev->queue->owner = NULL;
1127 	}
1128 	if (lock)
1129 		mutex_unlock(lock);
1130 	return v4l2_fh_release(file);
1131 }
1132 EXPORT_SYMBOL_GPL(_vb2_fop_release);
1133 
1134 int vb2_fop_release(struct file *file)
1135 {
1136 	struct video_device *vdev = video_devdata(file);
1137 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1138 
1139 	return _vb2_fop_release(file, lock);
1140 }
1141 EXPORT_SYMBOL_GPL(vb2_fop_release);
1142 
1143 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
1144 		size_t count, loff_t *ppos)
1145 {
1146 	struct video_device *vdev = video_devdata(file);
1147 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1148 	int err = -EBUSY;
1149 
1150 	if (!(vdev->queue->io_modes & VB2_WRITE))
1151 		return -EINVAL;
1152 	if (lock && mutex_lock_interruptible(lock))
1153 		return -ERESTARTSYS;
1154 	if (vb2_queue_is_busy(vdev, file))
1155 		goto exit;
1156 	err = vb2_write(vdev->queue, buf, count, ppos,
1157 		       file->f_flags & O_NONBLOCK);
1158 	if (vdev->queue->fileio)
1159 		vdev->queue->owner = file->private_data;
1160 exit:
1161 	if (lock)
1162 		mutex_unlock(lock);
1163 	return err;
1164 }
1165 EXPORT_SYMBOL_GPL(vb2_fop_write);
1166 
1167 ssize_t vb2_fop_read(struct file *file, char __user *buf,
1168 		size_t count, loff_t *ppos)
1169 {
1170 	struct video_device *vdev = video_devdata(file);
1171 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1172 	int err = -EBUSY;
1173 
1174 	if (!(vdev->queue->io_modes & VB2_READ))
1175 		return -EINVAL;
1176 	if (lock && mutex_lock_interruptible(lock))
1177 		return -ERESTARTSYS;
1178 	if (vb2_queue_is_busy(vdev, file))
1179 		goto exit;
1180 	err = vb2_read(vdev->queue, buf, count, ppos,
1181 		       file->f_flags & O_NONBLOCK);
1182 	if (vdev->queue->fileio)
1183 		vdev->queue->owner = file->private_data;
1184 exit:
1185 	if (lock)
1186 		mutex_unlock(lock);
1187 	return err;
1188 }
1189 EXPORT_SYMBOL_GPL(vb2_fop_read);
1190 
1191 __poll_t vb2_fop_poll(struct file *file, poll_table *wait)
1192 {
1193 	struct video_device *vdev = video_devdata(file);
1194 	struct vb2_queue *q = vdev->queue;
1195 	struct mutex *lock = q->lock ? q->lock : vdev->lock;
1196 	__poll_t res;
1197 	void *fileio;
1198 
1199 	/*
1200 	 * If this helper doesn't know how to lock, then you shouldn't be using
1201 	 * it but you should write your own.
1202 	 */
1203 	WARN_ON(!lock);
1204 
1205 	if (lock && mutex_lock_interruptible(lock))
1206 		return EPOLLERR;
1207 
1208 	fileio = q->fileio;
1209 
1210 	res = vb2_poll(vdev->queue, file, wait);
1211 
1212 	/* If fileio was started, then we have a new queue owner. */
1213 	if (!fileio && q->fileio)
1214 		q->owner = file->private_data;
1215 	if (lock)
1216 		mutex_unlock(lock);
1217 	return res;
1218 }
1219 EXPORT_SYMBOL_GPL(vb2_fop_poll);
1220 
1221 #ifndef CONFIG_MMU
1222 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
1223 		unsigned long len, unsigned long pgoff, unsigned long flags)
1224 {
1225 	struct video_device *vdev = video_devdata(file);
1226 
1227 	return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
1228 }
1229 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
1230 #endif
1231 
1232 void vb2_video_unregister_device(struct video_device *vdev)
1233 {
1234 	/* Check if vdev was ever registered at all */
1235 	if (!vdev || !video_is_registered(vdev))
1236 		return;
1237 
1238 	/*
1239 	 * Calling this function only makes sense if vdev->queue is set.
1240 	 * If it is NULL, then just call video_unregister_device() instead.
1241 	 */
1242 	WARN_ON(!vdev->queue);
1243 
1244 	/*
1245 	 * Take a reference to the device since video_unregister_device()
1246 	 * calls device_unregister(), but we don't want that to release
1247 	 * the device since we want to clean up the queue first.
1248 	 */
1249 	get_device(&vdev->dev);
1250 	video_unregister_device(vdev);
1251 	if (vdev->queue && vdev->queue->owner) {
1252 		struct mutex *lock = vdev->queue->lock ?
1253 			vdev->queue->lock : vdev->lock;
1254 
1255 		if (lock)
1256 			mutex_lock(lock);
1257 		vb2_queue_release(vdev->queue);
1258 		vdev->queue->owner = NULL;
1259 		if (lock)
1260 			mutex_unlock(lock);
1261 	}
1262 	/*
1263 	 * Now we put the device, and in most cases this will release
1264 	 * everything.
1265 	 */
1266 	put_device(&vdev->dev);
1267 }
1268 EXPORT_SYMBOL_GPL(vb2_video_unregister_device);
1269 
1270 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
1271 
1272 void vb2_ops_wait_prepare(struct vb2_queue *vq)
1273 {
1274 	mutex_unlock(vq->lock);
1275 }
1276 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
1277 
1278 void vb2_ops_wait_finish(struct vb2_queue *vq)
1279 {
1280 	mutex_lock(vq->lock);
1281 }
1282 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
1283 
1284 /*
1285  * Note that this function is called during validation time and
1286  * thus the req_queue_mutex is held to ensure no request objects
1287  * can be added or deleted while validating. So there is no need
1288  * to protect the objects list.
1289  */
1290 int vb2_request_validate(struct media_request *req)
1291 {
1292 	struct media_request_object *obj;
1293 	int ret = 0;
1294 
1295 	if (!vb2_request_buffer_cnt(req))
1296 		return -ENOENT;
1297 
1298 	list_for_each_entry(obj, &req->objects, list) {
1299 		if (!obj->ops->prepare)
1300 			continue;
1301 
1302 		ret = obj->ops->prepare(obj);
1303 		if (ret)
1304 			break;
1305 	}
1306 
1307 	if (ret) {
1308 		list_for_each_entry_continue_reverse(obj, &req->objects, list)
1309 			if (obj->ops->unprepare)
1310 				obj->ops->unprepare(obj);
1311 		return ret;
1312 	}
1313 	return 0;
1314 }
1315 EXPORT_SYMBOL_GPL(vb2_request_validate);
1316 
1317 void vb2_request_queue(struct media_request *req)
1318 {
1319 	struct media_request_object *obj, *obj_safe;
1320 
1321 	/*
1322 	 * Queue all objects. Note that buffer objects are at the end of the
1323 	 * objects list, after all other object types. Once buffer objects
1324 	 * are queued, the driver might delete them immediately (if the driver
1325 	 * processes the buffer at once), so we have to use
1326 	 * list_for_each_entry_safe() to handle the case where the object we
1327 	 * queue is deleted.
1328 	 */
1329 	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
1330 		if (obj->ops->queue)
1331 			obj->ops->queue(obj);
1332 }
1333 EXPORT_SYMBOL_GPL(vb2_request_queue);
1334 
1335 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
1336 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
1337 MODULE_LICENSE("GPL");
1338