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 	if (!vb2_queue_allows_cache_hints(q)) {
349 		/*
350 		 * Clear buffer cache flags if queue does not support user
351 		 * space hints. That's to indicate to userspace that these
352 		 * flags won't work.
353 		 */
354 		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;
355 		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;
356 		return;
357 	}
358 
359 	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
360 		vb->skip_cache_sync_on_finish = 1;
361 
362 	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
363 		vb->skip_cache_sync_on_prepare = 1;
364 }
365 
366 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
367 				    struct v4l2_buffer *b, bool is_prepare,
368 				    struct media_request **p_req)
369 {
370 	const char *opname = is_prepare ? "prepare_buf" : "qbuf";
371 	struct media_request *req;
372 	struct vb2_v4l2_buffer *vbuf;
373 	struct vb2_buffer *vb;
374 	int ret;
375 
376 	if (b->type != q->type) {
377 		dprintk(q, 1, "%s: invalid buffer type\n", opname);
378 		return -EINVAL;
379 	}
380 
381 	if (b->index >= q->num_buffers) {
382 		dprintk(q, 1, "%s: buffer index out of range\n", opname);
383 		return -EINVAL;
384 	}
385 
386 	if (q->bufs[b->index] == NULL) {
387 		/* Should never happen */
388 		dprintk(q, 1, "%s: buffer is NULL\n", opname);
389 		return -EINVAL;
390 	}
391 
392 	if (b->memory != q->memory) {
393 		dprintk(q, 1, "%s: invalid memory type\n", opname);
394 		return -EINVAL;
395 	}
396 
397 	vb = q->bufs[b->index];
398 	vbuf = to_vb2_v4l2_buffer(vb);
399 	ret = __verify_planes_array(vb, b);
400 	if (ret)
401 		return ret;
402 
403 	if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&
404 	    vb->state != VB2_BUF_STATE_DEQUEUED) {
405 		dprintk(q, 1, "%s: buffer is not in dequeued state\n", opname);
406 		return -EINVAL;
407 	}
408 
409 	if (!vb->prepared) {
410 		set_buffer_cache_hints(q, vb, b);
411 		/* Copy relevant information provided by the userspace */
412 		memset(vbuf->planes, 0,
413 		       sizeof(vbuf->planes[0]) * vb->num_planes);
414 		ret = vb2_fill_vb2_v4l2_buffer(vb, b);
415 		if (ret)
416 			return ret;
417 	}
418 
419 	if (is_prepare)
420 		return 0;
421 
422 	if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
423 		if (q->requires_requests) {
424 			dprintk(q, 1, "%s: queue requires requests\n", opname);
425 			return -EBADR;
426 		}
427 		if (q->uses_requests) {
428 			dprintk(q, 1, "%s: queue uses requests\n", opname);
429 			return -EBUSY;
430 		}
431 		return 0;
432 	} else if (!q->supports_requests) {
433 		dprintk(q, 1, "%s: queue does not support requests\n", opname);
434 		return -EBADR;
435 	} else if (q->uses_qbuf) {
436 		dprintk(q, 1, "%s: queue does not use requests\n", opname);
437 		return -EBUSY;
438 	}
439 
440 	/*
441 	 * For proper locking when queueing a request you need to be able
442 	 * to lock access to the vb2 queue, so check that there is a lock
443 	 * that we can use. In addition p_req must be non-NULL.
444 	 */
445 	if (WARN_ON(!q->lock || !p_req))
446 		return -EINVAL;
447 
448 	/*
449 	 * Make sure this op is implemented by the driver. It's easy to forget
450 	 * this callback, but is it important when canceling a buffer in a
451 	 * queued request.
452 	 */
453 	if (WARN_ON(!q->ops->buf_request_complete))
454 		return -EINVAL;
455 	/*
456 	 * Make sure this op is implemented by the driver for the output queue.
457 	 * It's easy to forget this callback, but is it important to correctly
458 	 * validate the 'field' value at QBUF time.
459 	 */
460 	if (WARN_ON((q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||
461 		     q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) &&
462 		    !q->ops->buf_out_validate))
463 		return -EINVAL;
464 
465 	req = media_request_get_by_fd(mdev, b->request_fd);
466 	if (IS_ERR(req)) {
467 		dprintk(q, 1, "%s: invalid request_fd\n", opname);
468 		return PTR_ERR(req);
469 	}
470 
471 	/*
472 	 * Early sanity check. This is checked again when the buffer
473 	 * is bound to the request in vb2_core_qbuf().
474 	 */
475 	if (req->state != MEDIA_REQUEST_STATE_IDLE &&
476 	    req->state != MEDIA_REQUEST_STATE_UPDATING) {
477 		dprintk(q, 1, "%s: request is not idle\n", opname);
478 		media_request_put(req);
479 		return -EBUSY;
480 	}
481 
482 	*p_req = req;
483 	vbuf->request_fd = b->request_fd;
484 
485 	return 0;
486 }
487 
488 /*
489  * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
490  * returned to userspace
491  */
492 static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
493 {
494 	struct v4l2_buffer *b = pb;
495 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
496 	struct vb2_queue *q = vb->vb2_queue;
497 	unsigned int plane;
498 
499 	/* Copy back data such as timestamp, flags, etc. */
500 	b->index = vb->index;
501 	b->type = vb->type;
502 	b->memory = vb->memory;
503 	b->bytesused = 0;
504 
505 	b->flags = vbuf->flags;
506 	b->field = vbuf->field;
507 	v4l2_buffer_set_timestamp(b, vb->timestamp);
508 	b->timecode = vbuf->timecode;
509 	b->sequence = vbuf->sequence;
510 	b->reserved2 = 0;
511 	b->request_fd = 0;
512 
513 	if (q->is_multiplanar) {
514 		/*
515 		 * Fill in plane-related data if userspace provided an array
516 		 * for it. The caller has already verified memory and size.
517 		 */
518 		b->length = vb->num_planes;
519 		for (plane = 0; plane < vb->num_planes; ++plane) {
520 			struct v4l2_plane *pdst = &b->m.planes[plane];
521 			struct vb2_plane *psrc = &vb->planes[plane];
522 
523 			pdst->bytesused = psrc->bytesused;
524 			pdst->length = psrc->length;
525 			if (q->memory == VB2_MEMORY_MMAP)
526 				pdst->m.mem_offset = psrc->m.offset;
527 			else if (q->memory == VB2_MEMORY_USERPTR)
528 				pdst->m.userptr = psrc->m.userptr;
529 			else if (q->memory == VB2_MEMORY_DMABUF)
530 				pdst->m.fd = psrc->m.fd;
531 			pdst->data_offset = psrc->data_offset;
532 			memset(pdst->reserved, 0, sizeof(pdst->reserved));
533 		}
534 	} else {
535 		/*
536 		 * We use length and offset in v4l2_planes array even for
537 		 * single-planar buffers, but userspace does not.
538 		 */
539 		b->length = vb->planes[0].length;
540 		b->bytesused = vb->planes[0].bytesused;
541 		if (q->memory == VB2_MEMORY_MMAP)
542 			b->m.offset = vb->planes[0].m.offset;
543 		else if (q->memory == VB2_MEMORY_USERPTR)
544 			b->m.userptr = vb->planes[0].m.userptr;
545 		else if (q->memory == VB2_MEMORY_DMABUF)
546 			b->m.fd = vb->planes[0].m.fd;
547 	}
548 
549 	/*
550 	 * Clear any buffer state related flags.
551 	 */
552 	b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
553 	b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
554 	if (!q->copy_timestamp) {
555 		/*
556 		 * For non-COPY timestamps, drop timestamp source bits
557 		 * and obtain the timestamp source from the queue.
558 		 */
559 		b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
560 		b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
561 	}
562 
563 	switch (vb->state) {
564 	case VB2_BUF_STATE_QUEUED:
565 	case VB2_BUF_STATE_ACTIVE:
566 		b->flags |= V4L2_BUF_FLAG_QUEUED;
567 		break;
568 	case VB2_BUF_STATE_IN_REQUEST:
569 		b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
570 		break;
571 	case VB2_BUF_STATE_ERROR:
572 		b->flags |= V4L2_BUF_FLAG_ERROR;
573 		fallthrough;
574 	case VB2_BUF_STATE_DONE:
575 		b->flags |= V4L2_BUF_FLAG_DONE;
576 		break;
577 	case VB2_BUF_STATE_PREPARING:
578 	case VB2_BUF_STATE_DEQUEUED:
579 		/* nothing */
580 		break;
581 	}
582 
583 	if ((vb->state == VB2_BUF_STATE_DEQUEUED ||
584 	     vb->state == VB2_BUF_STATE_IN_REQUEST) &&
585 	    vb->synced && vb->prepared)
586 		b->flags |= V4L2_BUF_FLAG_PREPARED;
587 
588 	if (vb2_buffer_in_use(q, vb))
589 		b->flags |= V4L2_BUF_FLAG_MAPPED;
590 	if (vbuf->request_fd >= 0) {
591 		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
592 		b->request_fd = vbuf->request_fd;
593 	}
594 }
595 
596 /*
597  * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
598  * v4l2_buffer by the userspace. It also verifies that struct
599  * v4l2_buffer has a valid number of planes.
600  */
601 static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
602 {
603 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
604 	unsigned int plane;
605 
606 	if (!vb->vb2_queue->copy_timestamp)
607 		vb->timestamp = 0;
608 
609 	for (plane = 0; plane < vb->num_planes; ++plane) {
610 		if (vb->vb2_queue->memory != VB2_MEMORY_MMAP) {
611 			planes[plane].m = vbuf->planes[plane].m;
612 			planes[plane].length = vbuf->planes[plane].length;
613 		}
614 		planes[plane].bytesused = vbuf->planes[plane].bytesused;
615 		planes[plane].data_offset = vbuf->planes[plane].data_offset;
616 	}
617 	return 0;
618 }
619 
620 static const struct vb2_buf_ops v4l2_buf_ops = {
621 	.verify_planes_array	= __verify_planes_array_core,
622 	.init_buffer		= __init_vb2_v4l2_buffer,
623 	.fill_user_buffer	= __fill_v4l2_buffer,
624 	.fill_vb2_buffer	= __fill_vb2_buffer,
625 	.copy_timestamp		= __copy_timestamp,
626 };
627 
628 int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
629 		       unsigned int start_idx)
630 {
631 	unsigned int i;
632 
633 	for (i = start_idx; i < q->num_buffers; i++)
634 		if (q->bufs[i]->copied_timestamp &&
635 		    q->bufs[i]->timestamp == timestamp)
636 			return i;
637 	return -1;
638 }
639 EXPORT_SYMBOL_GPL(vb2_find_timestamp);
640 
641 struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)
642 {
643 	unsigned int i;
644 
645 	for (i = 0; i < q->num_buffers; i++)
646 		if (q->bufs[i]->copied_timestamp &&
647 		    q->bufs[i]->timestamp == timestamp)
648 			return vb2_get_buffer(q, i);
649 	return NULL;
650 }
651 EXPORT_SYMBOL_GPL(vb2_find_buffer);
652 
653 /*
654  * vb2_querybuf() - query video buffer information
655  * @q:		videobuf queue
656  * @b:		buffer struct passed from userspace to vidioc_querybuf handler
657  *		in driver
658  *
659  * Should be called from vidioc_querybuf ioctl handler in driver.
660  * This function will verify the passed v4l2_buffer structure and fill the
661  * relevant information for the userspace.
662  *
663  * The return values from this function are intended to be directly returned
664  * from vidioc_querybuf handler in driver.
665  */
666 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
667 {
668 	struct vb2_buffer *vb;
669 	int ret;
670 
671 	if (b->type != q->type) {
672 		dprintk(q, 1, "wrong buffer type\n");
673 		return -EINVAL;
674 	}
675 
676 	if (b->index >= q->num_buffers) {
677 		dprintk(q, 1, "buffer index out of range\n");
678 		return -EINVAL;
679 	}
680 	vb = q->bufs[b->index];
681 	ret = __verify_planes_array(vb, b);
682 	if (!ret)
683 		vb2_core_querybuf(q, b->index, b);
684 	return ret;
685 }
686 EXPORT_SYMBOL(vb2_querybuf);
687 
688 static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
689 {
690 	*caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
691 	if (q->io_modes & VB2_MMAP)
692 		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP;
693 	if (q->io_modes & VB2_USERPTR)
694 		*caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;
695 	if (q->io_modes & VB2_DMABUF)
696 		*caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
697 	if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)
698 		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
699 	if (q->allow_cache_hints && q->io_modes & VB2_MMAP)
700 		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
701 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
702 	if (q->supports_requests)
703 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
704 #endif
705 }
706 
707 static void validate_memory_flags(struct vb2_queue *q,
708 				  int memory,
709 				  u32 *flags)
710 {
711 	if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) {
712 		/*
713 		 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only,
714 		 * but in order to avoid bugs we zero out all bits.
715 		 */
716 		*flags = 0;
717 	} else {
718 		/* Clear all unknown flags. */
719 		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
720 	}
721 }
722 
723 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
724 {
725 	int ret = vb2_verify_memory_type(q, req->memory, req->type);
726 	u32 flags = req->flags;
727 
728 	fill_buf_caps(q, &req->capabilities);
729 	validate_memory_flags(q, req->memory, &flags);
730 	req->flags = flags;
731 	return ret ? ret : vb2_core_reqbufs(q, req->memory,
732 					    req->flags, &req->count);
733 }
734 EXPORT_SYMBOL_GPL(vb2_reqbufs);
735 
736 int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
737 		    struct v4l2_buffer *b)
738 {
739 	int ret;
740 
741 	if (vb2_fileio_is_active(q)) {
742 		dprintk(q, 1, "file io in progress\n");
743 		return -EBUSY;
744 	}
745 
746 	if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)
747 		return -EINVAL;
748 
749 	ret = vb2_queue_or_prepare_buf(q, mdev, b, true, NULL);
750 
751 	return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
752 }
753 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
754 
755 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
756 {
757 	unsigned requested_planes = 1;
758 	unsigned requested_sizes[VIDEO_MAX_PLANES];
759 	struct v4l2_format *f = &create->format;
760 	int ret = vb2_verify_memory_type(q, create->memory, f->type);
761 	unsigned i;
762 
763 	fill_buf_caps(q, &create->capabilities);
764 	validate_memory_flags(q, create->memory, &create->flags);
765 	create->index = q->num_buffers;
766 	if (create->count == 0)
767 		return ret != -EBUSY ? ret : 0;
768 
769 	switch (f->type) {
770 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
771 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
772 		requested_planes = f->fmt.pix_mp.num_planes;
773 		if (requested_planes == 0 ||
774 		    requested_planes > VIDEO_MAX_PLANES)
775 			return -EINVAL;
776 		for (i = 0; i < requested_planes; i++)
777 			requested_sizes[i] =
778 				f->fmt.pix_mp.plane_fmt[i].sizeimage;
779 		break;
780 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
781 	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
782 		requested_sizes[0] = f->fmt.pix.sizeimage;
783 		break;
784 	case V4L2_BUF_TYPE_VBI_CAPTURE:
785 	case V4L2_BUF_TYPE_VBI_OUTPUT:
786 		requested_sizes[0] = f->fmt.vbi.samples_per_line *
787 			(f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);
788 		break;
789 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
790 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
791 		requested_sizes[0] = f->fmt.sliced.io_size;
792 		break;
793 	case V4L2_BUF_TYPE_SDR_CAPTURE:
794 	case V4L2_BUF_TYPE_SDR_OUTPUT:
795 		requested_sizes[0] = f->fmt.sdr.buffersize;
796 		break;
797 	case V4L2_BUF_TYPE_META_CAPTURE:
798 	case V4L2_BUF_TYPE_META_OUTPUT:
799 		requested_sizes[0] = f->fmt.meta.buffersize;
800 		break;
801 	default:
802 		return -EINVAL;
803 	}
804 	for (i = 0; i < requested_planes; i++)
805 		if (requested_sizes[i] == 0)
806 			return -EINVAL;
807 	return ret ? ret : vb2_core_create_bufs(q, create->memory,
808 						create->flags,
809 						&create->count,
810 						requested_planes,
811 						requested_sizes);
812 }
813 EXPORT_SYMBOL_GPL(vb2_create_bufs);
814 
815 int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
816 	     struct v4l2_buffer *b)
817 {
818 	struct media_request *req = NULL;
819 	int ret;
820 
821 	if (vb2_fileio_is_active(q)) {
822 		dprintk(q, 1, "file io in progress\n");
823 		return -EBUSY;
824 	}
825 
826 	ret = vb2_queue_or_prepare_buf(q, mdev, b, false, &req);
827 	if (ret)
828 		return ret;
829 	ret = vb2_core_qbuf(q, b->index, b, req);
830 	if (req)
831 		media_request_put(req);
832 	return ret;
833 }
834 EXPORT_SYMBOL_GPL(vb2_qbuf);
835 
836 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
837 {
838 	int ret;
839 
840 	if (vb2_fileio_is_active(q)) {
841 		dprintk(q, 1, "file io in progress\n");
842 		return -EBUSY;
843 	}
844 
845 	if (b->type != q->type) {
846 		dprintk(q, 1, "invalid buffer type\n");
847 		return -EINVAL;
848 	}
849 
850 	ret = vb2_core_dqbuf(q, NULL, b, nonblocking);
851 
852 	if (!q->is_output &&
853 	    b->flags & V4L2_BUF_FLAG_DONE &&
854 	    b->flags & V4L2_BUF_FLAG_LAST)
855 		q->last_buffer_dequeued = true;
856 
857 	/*
858 	 *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
859 	 *  cleared.
860 	 */
861 	b->flags &= ~V4L2_BUF_FLAG_DONE;
862 
863 	return ret;
864 }
865 EXPORT_SYMBOL_GPL(vb2_dqbuf);
866 
867 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
868 {
869 	if (vb2_fileio_is_active(q)) {
870 		dprintk(q, 1, "file io in progress\n");
871 		return -EBUSY;
872 	}
873 	return vb2_core_streamon(q, type);
874 }
875 EXPORT_SYMBOL_GPL(vb2_streamon);
876 
877 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
878 {
879 	if (vb2_fileio_is_active(q)) {
880 		dprintk(q, 1, "file io in progress\n");
881 		return -EBUSY;
882 	}
883 	return vb2_core_streamoff(q, type);
884 }
885 EXPORT_SYMBOL_GPL(vb2_streamoff);
886 
887 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
888 {
889 	return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index,
890 				eb->plane, eb->flags);
891 }
892 EXPORT_SYMBOL_GPL(vb2_expbuf);
893 
894 int vb2_queue_init_name(struct vb2_queue *q, const char *name)
895 {
896 	/*
897 	 * Sanity check
898 	 */
899 	if (WARN_ON(!q)			  ||
900 	    WARN_ON(q->timestamp_flags &
901 		    ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
902 		      V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
903 		return -EINVAL;
904 
905 	/* Warn that the driver should choose an appropriate timestamp type */
906 	WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
907 		V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
908 
909 	/* Warn that vb2_memory should match with v4l2_memory */
910 	if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
911 		|| WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
912 		|| WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
913 		return -EINVAL;
914 
915 	if (q->buf_struct_size == 0)
916 		q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
917 
918 	q->buf_ops = &v4l2_buf_ops;
919 	q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
920 	q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
921 	q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
922 			== V4L2_BUF_FLAG_TIMESTAMP_COPY;
923 	/*
924 	 * For compatibility with vb1: if QBUF hasn't been called yet, then
925 	 * return EPOLLERR as well. This only affects capture queues, output
926 	 * queues will always initialize waiting_for_buffers to false.
927 	 */
928 	q->quirk_poll_must_check_waiting_for_buffers = true;
929 
930 	if (name)
931 		strscpy(q->name, name, sizeof(q->name));
932 	else
933 		q->name[0] = '\0';
934 
935 	return vb2_core_queue_init(q);
936 }
937 EXPORT_SYMBOL_GPL(vb2_queue_init_name);
938 
939 int vb2_queue_init(struct vb2_queue *q)
940 {
941 	return vb2_queue_init_name(q, NULL);
942 }
943 EXPORT_SYMBOL_GPL(vb2_queue_init);
944 
945 void vb2_queue_release(struct vb2_queue *q)
946 {
947 	vb2_core_queue_release(q);
948 }
949 EXPORT_SYMBOL_GPL(vb2_queue_release);
950 
951 int vb2_queue_change_type(struct vb2_queue *q, unsigned int type)
952 {
953 	if (type == q->type)
954 		return 0;
955 
956 	if (vb2_is_busy(q))
957 		return -EBUSY;
958 
959 	q->type = type;
960 
961 	return 0;
962 }
963 EXPORT_SYMBOL_GPL(vb2_queue_change_type);
964 
965 __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
966 {
967 	struct video_device *vfd = video_devdata(file);
968 	__poll_t res;
969 
970 	res = vb2_core_poll(q, file, wait);
971 
972 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
973 		struct v4l2_fh *fh = file->private_data;
974 
975 		poll_wait(file, &fh->wait, wait);
976 		if (v4l2_event_pending(fh))
977 			res |= EPOLLPRI;
978 	}
979 
980 	return res;
981 }
982 EXPORT_SYMBOL_GPL(vb2_poll);
983 
984 /*
985  * The following functions are not part of the vb2 core API, but are helper
986  * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
987  * and struct vb2_ops.
988  * They contain boilerplate code that most if not all drivers have to do
989  * and so they simplify the driver code.
990  */
991 
992 /* vb2 ioctl helpers */
993 
994 int vb2_ioctl_reqbufs(struct file *file, void *priv,
995 			  struct v4l2_requestbuffers *p)
996 {
997 	struct video_device *vdev = video_devdata(file);
998 	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
999 	u32 flags = p->flags;
1000 
1001 	fill_buf_caps(vdev->queue, &p->capabilities);
1002 	validate_memory_flags(vdev->queue, p->memory, &flags);
1003 	p->flags = flags;
1004 	if (res)
1005 		return res;
1006 	if (vb2_queue_is_busy(vdev->queue, file))
1007 		return -EBUSY;
1008 	res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count);
1009 	/* If count == 0, then the owner has released all buffers and he
1010 	   is no longer owner of the queue. Otherwise we have a new owner. */
1011 	if (res == 0)
1012 		vdev->queue->owner = p->count ? file->private_data : NULL;
1013 	return res;
1014 }
1015 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
1016 
1017 int vb2_ioctl_create_bufs(struct file *file, void *priv,
1018 			  struct v4l2_create_buffers *p)
1019 {
1020 	struct video_device *vdev = video_devdata(file);
1021 	int res = vb2_verify_memory_type(vdev->queue, p->memory,
1022 			p->format.type);
1023 
1024 	p->index = vdev->queue->num_buffers;
1025 	fill_buf_caps(vdev->queue, &p->capabilities);
1026 	validate_memory_flags(vdev->queue, p->memory, &p->flags);
1027 	/*
1028 	 * If count == 0, then just check if memory and type are valid.
1029 	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
1030 	 */
1031 	if (p->count == 0)
1032 		return res != -EBUSY ? res : 0;
1033 	if (res)
1034 		return res;
1035 	if (vb2_queue_is_busy(vdev->queue, file))
1036 		return -EBUSY;
1037 
1038 	res = vb2_create_bufs(vdev->queue, p);
1039 	if (res == 0)
1040 		vdev->queue->owner = file->private_data;
1041 	return res;
1042 }
1043 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
1044 
1045 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
1046 			  struct v4l2_buffer *p)
1047 {
1048 	struct video_device *vdev = video_devdata(file);
1049 
1050 	if (vb2_queue_is_busy(vdev->queue, file))
1051 		return -EBUSY;
1052 	return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
1053 }
1054 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
1055 
1056 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
1057 {
1058 	struct video_device *vdev = video_devdata(file);
1059 
1060 	/* No need to call vb2_queue_is_busy(), anyone can query buffers. */
1061 	return vb2_querybuf(vdev->queue, p);
1062 }
1063 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
1064 
1065 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1066 {
1067 	struct video_device *vdev = video_devdata(file);
1068 
1069 	if (vb2_queue_is_busy(vdev->queue, file))
1070 		return -EBUSY;
1071 	return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
1072 }
1073 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
1074 
1075 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1076 {
1077 	struct video_device *vdev = video_devdata(file);
1078 
1079 	if (vb2_queue_is_busy(vdev->queue, file))
1080 		return -EBUSY;
1081 	return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
1082 }
1083 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
1084 
1085 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
1086 {
1087 	struct video_device *vdev = video_devdata(file);
1088 
1089 	if (vb2_queue_is_busy(vdev->queue, file))
1090 		return -EBUSY;
1091 	return vb2_streamon(vdev->queue, i);
1092 }
1093 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
1094 
1095 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
1096 {
1097 	struct video_device *vdev = video_devdata(file);
1098 
1099 	if (vb2_queue_is_busy(vdev->queue, file))
1100 		return -EBUSY;
1101 	return vb2_streamoff(vdev->queue, i);
1102 }
1103 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
1104 
1105 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
1106 {
1107 	struct video_device *vdev = video_devdata(file);
1108 
1109 	if (vb2_queue_is_busy(vdev->queue, file))
1110 		return -EBUSY;
1111 	return vb2_expbuf(vdev->queue, p);
1112 }
1113 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
1114 
1115 /* v4l2_file_operations helpers */
1116 
1117 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
1118 {
1119 	struct video_device *vdev = video_devdata(file);
1120 
1121 	return vb2_mmap(vdev->queue, vma);
1122 }
1123 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
1124 
1125 int _vb2_fop_release(struct file *file, struct mutex *lock)
1126 {
1127 	struct video_device *vdev = video_devdata(file);
1128 
1129 	if (lock)
1130 		mutex_lock(lock);
1131 	if (file->private_data == vdev->queue->owner) {
1132 		vb2_queue_release(vdev->queue);
1133 		vdev->queue->owner = NULL;
1134 	}
1135 	if (lock)
1136 		mutex_unlock(lock);
1137 	return v4l2_fh_release(file);
1138 }
1139 EXPORT_SYMBOL_GPL(_vb2_fop_release);
1140 
1141 int vb2_fop_release(struct file *file)
1142 {
1143 	struct video_device *vdev = video_devdata(file);
1144 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1145 
1146 	return _vb2_fop_release(file, lock);
1147 }
1148 EXPORT_SYMBOL_GPL(vb2_fop_release);
1149 
1150 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
1151 		size_t count, loff_t *ppos)
1152 {
1153 	struct video_device *vdev = video_devdata(file);
1154 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1155 	int err = -EBUSY;
1156 
1157 	if (!(vdev->queue->io_modes & VB2_WRITE))
1158 		return -EINVAL;
1159 	if (lock && mutex_lock_interruptible(lock))
1160 		return -ERESTARTSYS;
1161 	if (vb2_queue_is_busy(vdev->queue, file))
1162 		goto exit;
1163 	err = vb2_write(vdev->queue, buf, count, ppos,
1164 		       file->f_flags & O_NONBLOCK);
1165 	if (vdev->queue->fileio)
1166 		vdev->queue->owner = file->private_data;
1167 exit:
1168 	if (lock)
1169 		mutex_unlock(lock);
1170 	return err;
1171 }
1172 EXPORT_SYMBOL_GPL(vb2_fop_write);
1173 
1174 ssize_t vb2_fop_read(struct file *file, char __user *buf,
1175 		size_t count, loff_t *ppos)
1176 {
1177 	struct video_device *vdev = video_devdata(file);
1178 	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1179 	int err = -EBUSY;
1180 
1181 	if (!(vdev->queue->io_modes & VB2_READ))
1182 		return -EINVAL;
1183 	if (lock && mutex_lock_interruptible(lock))
1184 		return -ERESTARTSYS;
1185 	if (vb2_queue_is_busy(vdev->queue, file))
1186 		goto exit;
1187 	err = vb2_read(vdev->queue, buf, count, ppos,
1188 		       file->f_flags & O_NONBLOCK);
1189 	if (vdev->queue->fileio)
1190 		vdev->queue->owner = file->private_data;
1191 exit:
1192 	if (lock)
1193 		mutex_unlock(lock);
1194 	return err;
1195 }
1196 EXPORT_SYMBOL_GPL(vb2_fop_read);
1197 
1198 __poll_t vb2_fop_poll(struct file *file, poll_table *wait)
1199 {
1200 	struct video_device *vdev = video_devdata(file);
1201 	struct vb2_queue *q = vdev->queue;
1202 	struct mutex *lock = q->lock ? q->lock : vdev->lock;
1203 	__poll_t res;
1204 	void *fileio;
1205 
1206 	/*
1207 	 * If this helper doesn't know how to lock, then you shouldn't be using
1208 	 * it but you should write your own.
1209 	 */
1210 	WARN_ON(!lock);
1211 
1212 	if (lock && mutex_lock_interruptible(lock))
1213 		return EPOLLERR;
1214 
1215 	fileio = q->fileio;
1216 
1217 	res = vb2_poll(vdev->queue, file, wait);
1218 
1219 	/* If fileio was started, then we have a new queue owner. */
1220 	if (!fileio && q->fileio)
1221 		q->owner = file->private_data;
1222 	if (lock)
1223 		mutex_unlock(lock);
1224 	return res;
1225 }
1226 EXPORT_SYMBOL_GPL(vb2_fop_poll);
1227 
1228 #ifndef CONFIG_MMU
1229 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
1230 		unsigned long len, unsigned long pgoff, unsigned long flags)
1231 {
1232 	struct video_device *vdev = video_devdata(file);
1233 
1234 	return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
1235 }
1236 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
1237 #endif
1238 
1239 void vb2_video_unregister_device(struct video_device *vdev)
1240 {
1241 	/* Check if vdev was ever registered at all */
1242 	if (!vdev || !video_is_registered(vdev))
1243 		return;
1244 
1245 	/*
1246 	 * Calling this function only makes sense if vdev->queue is set.
1247 	 * If it is NULL, then just call video_unregister_device() instead.
1248 	 */
1249 	WARN_ON(!vdev->queue);
1250 
1251 	/*
1252 	 * Take a reference to the device since video_unregister_device()
1253 	 * calls device_unregister(), but we don't want that to release
1254 	 * the device since we want to clean up the queue first.
1255 	 */
1256 	get_device(&vdev->dev);
1257 	video_unregister_device(vdev);
1258 	if (vdev->queue && vdev->queue->owner) {
1259 		struct mutex *lock = vdev->queue->lock ?
1260 			vdev->queue->lock : vdev->lock;
1261 
1262 		if (lock)
1263 			mutex_lock(lock);
1264 		vb2_queue_release(vdev->queue);
1265 		vdev->queue->owner = NULL;
1266 		if (lock)
1267 			mutex_unlock(lock);
1268 	}
1269 	/*
1270 	 * Now we put the device, and in most cases this will release
1271 	 * everything.
1272 	 */
1273 	put_device(&vdev->dev);
1274 }
1275 EXPORT_SYMBOL_GPL(vb2_video_unregister_device);
1276 
1277 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
1278 
1279 void vb2_ops_wait_prepare(struct vb2_queue *vq)
1280 {
1281 	mutex_unlock(vq->lock);
1282 }
1283 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
1284 
1285 void vb2_ops_wait_finish(struct vb2_queue *vq)
1286 {
1287 	mutex_lock(vq->lock);
1288 }
1289 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
1290 
1291 /*
1292  * Note that this function is called during validation time and
1293  * thus the req_queue_mutex is held to ensure no request objects
1294  * can be added or deleted while validating. So there is no need
1295  * to protect the objects list.
1296  */
1297 int vb2_request_validate(struct media_request *req)
1298 {
1299 	struct media_request_object *obj;
1300 	int ret = 0;
1301 
1302 	if (!vb2_request_buffer_cnt(req))
1303 		return -ENOENT;
1304 
1305 	list_for_each_entry(obj, &req->objects, list) {
1306 		if (!obj->ops->prepare)
1307 			continue;
1308 
1309 		ret = obj->ops->prepare(obj);
1310 		if (ret)
1311 			break;
1312 	}
1313 
1314 	if (ret) {
1315 		list_for_each_entry_continue_reverse(obj, &req->objects, list)
1316 			if (obj->ops->unprepare)
1317 				obj->ops->unprepare(obj);
1318 		return ret;
1319 	}
1320 	return 0;
1321 }
1322 EXPORT_SYMBOL_GPL(vb2_request_validate);
1323 
1324 void vb2_request_queue(struct media_request *req)
1325 {
1326 	struct media_request_object *obj, *obj_safe;
1327 
1328 	/*
1329 	 * Queue all objects. Note that buffer objects are at the end of the
1330 	 * objects list, after all other object types. Once buffer objects
1331 	 * are queued, the driver might delete them immediately (if the driver
1332 	 * processes the buffer at once), so we have to use
1333 	 * list_for_each_entry_safe() to handle the case where the object we
1334 	 * queue is deleted.
1335 	 */
1336 	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
1337 		if (obj->ops->queue)
1338 			obj->ops->queue(obj);
1339 }
1340 EXPORT_SYMBOL_GPL(vb2_request_queue);
1341 
1342 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
1343 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
1344 MODULE_LICENSE("GPL");
1345