2 * videobuf2-core.c - V4L2 driver helper framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation.
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
22 #include <media/v4l2-dev.h>
23 #include <media/v4l2-fh.h>
24 #include <media/v4l2-event.h>
25 #include <media/v4l2-common.h>
26 #include <media/videobuf2-core.h>
29 module_param(debug, int, 0644);
31 #define dprintk(level, fmt, arg...) \
34 pr_debug("vb2: %s: " fmt, __func__, ## arg); \
37 #ifdef CONFIG_VIDEO_ADV_DEBUG
40 * If advanced debugging is on, then count how often each op is called
41 * successfully, which can either be per-buffer or per-queue.
43 * This makes it easy to check that the 'init' and 'cleanup'
44 * (and variations thereof) stay balanced.
47 #define log_memop(vb, op) \
48 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
49 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
50 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
52 #define call_memop(vb, op, args...) \
54 struct vb2_queue *_q = (vb)->vb2_queue; \
58 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
60 (vb)->cnt_mem_ ## op++; \
64 #define call_ptr_memop(vb, op, args...) \
66 struct vb2_queue *_q = (vb)->vb2_queue; \
70 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
71 if (!IS_ERR_OR_NULL(ptr)) \
72 (vb)->cnt_mem_ ## op++; \
76 #define call_void_memop(vb, op, args...) \
78 struct vb2_queue *_q = (vb)->vb2_queue; \
81 if (_q->mem_ops->op) \
82 _q->mem_ops->op(args); \
83 (vb)->cnt_mem_ ## op++; \
86 #define log_qop(q, op) \
87 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
88 (q)->ops->op ? "" : " (nop)")
90 #define call_qop(q, op, args...) \
95 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
101 #define call_void_qop(q, op, args...) \
105 (q)->ops->op(args); \
109 #define log_vb_qop(vb, op, args...) \
110 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
111 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
112 (vb)->vb2_queue->ops->op ? "" : " (nop)")
114 #define call_vb_qop(vb, op, args...) \
118 log_vb_qop(vb, op); \
119 err = (vb)->vb2_queue->ops->op ? \
120 (vb)->vb2_queue->ops->op(args) : 0; \
122 (vb)->cnt_ ## op++; \
126 #define call_void_vb_qop(vb, op, args...) \
128 log_vb_qop(vb, op); \
129 if ((vb)->vb2_queue->ops->op) \
130 (vb)->vb2_queue->ops->op(args); \
131 (vb)->cnt_ ## op++; \
136 #define call_memop(vb, op, args...) \
137 ((vb)->vb2_queue->mem_ops->op ? \
138 (vb)->vb2_queue->mem_ops->op(args) : 0)
140 #define call_ptr_memop(vb, op, args...) \
141 ((vb)->vb2_queue->mem_ops->op ? \
142 (vb)->vb2_queue->mem_ops->op(args) : NULL)
144 #define call_void_memop(vb, op, args...) \
146 if ((vb)->vb2_queue->mem_ops->op) \
147 (vb)->vb2_queue->mem_ops->op(args); \
150 #define call_qop(q, op, args...) \
151 ((q)->ops->op ? (q)->ops->op(args) : 0)
153 #define call_void_qop(q, op, args...) \
156 (q)->ops->op(args); \
159 #define call_vb_qop(vb, op, args...) \
160 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
162 #define call_void_vb_qop(vb, op, args...) \
164 if ((vb)->vb2_queue->ops->op) \
165 (vb)->vb2_queue->ops->op(args); \
170 /* Flags that are set by the vb2 core */
171 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
172 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
173 V4L2_BUF_FLAG_PREPARED | \
174 V4L2_BUF_FLAG_TIMESTAMP_MASK)
175 /* Output buffer flags that should be passed on to the driver */
176 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
177 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
179 static void __vb2_queue_cancel(struct vb2_queue *q);
182 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
184 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
186 struct vb2_queue *q = vb->vb2_queue;
191 * Allocate memory for all planes in this buffer
192 * NOTE: mmapped areas should be page aligned
194 for (plane = 0; plane < vb->num_planes; ++plane) {
195 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
197 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
199 if (IS_ERR_OR_NULL(mem_priv))
202 /* Associate allocator private data with this plane */
203 vb->planes[plane].mem_priv = mem_priv;
204 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
209 /* Free already allocated memory if one of the allocations failed */
210 for (; plane > 0; --plane) {
211 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
212 vb->planes[plane - 1].mem_priv = NULL;
219 * __vb2_buf_mem_free() - free memory of the given buffer
221 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
225 for (plane = 0; plane < vb->num_planes; ++plane) {
226 call_void_memop(vb, put, vb->planes[plane].mem_priv);
227 vb->planes[plane].mem_priv = NULL;
228 dprintk(3, "Freed plane %d of buffer %d\n", plane,
234 * __vb2_buf_userptr_put() - release userspace memory associated with
237 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
241 for (plane = 0; plane < vb->num_planes; ++plane) {
242 if (vb->planes[plane].mem_priv)
243 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
244 vb->planes[plane].mem_priv = NULL;
249 * __vb2_plane_dmabuf_put() - release memory associated with
250 * a DMABUF shared plane
252 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
258 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
260 call_void_memop(vb, detach_dmabuf, p->mem_priv);
261 dma_buf_put(p->dbuf);
262 memset(p, 0, sizeof(*p));
266 * __vb2_buf_dmabuf_put() - release memory associated with
267 * a DMABUF shared buffer
269 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
273 for (plane = 0; plane < vb->num_planes; ++plane)
274 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
278 * __setup_lengths() - setup initial lengths for every plane in
279 * every buffer on the queue
281 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
283 unsigned int buffer, plane;
284 struct vb2_buffer *vb;
286 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
287 vb = q->bufs[buffer];
291 for (plane = 0; plane < vb->num_planes; ++plane)
292 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
297 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
298 * every buffer on the queue
300 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
302 unsigned int buffer, plane;
303 struct vb2_buffer *vb;
306 if (q->num_buffers) {
307 struct v4l2_plane *p;
308 vb = q->bufs[q->num_buffers - 1];
309 p = &vb->v4l2_planes[vb->num_planes - 1];
310 off = PAGE_ALIGN(p->m.mem_offset + p->length);
315 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
316 vb = q->bufs[buffer];
320 for (plane = 0; plane < vb->num_planes; ++plane) {
321 vb->v4l2_planes[plane].m.mem_offset = off;
323 dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
326 off += vb->v4l2_planes[plane].length;
327 off = PAGE_ALIGN(off);
333 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
334 * video buffer memory for all buffers/planes on the queue and initializes the
337 * Returns the number of buffers successfully allocated.
339 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
340 unsigned int num_buffers, unsigned int num_planes)
343 struct vb2_buffer *vb;
346 for (buffer = 0; buffer < num_buffers; ++buffer) {
347 /* Allocate videobuf buffer structures */
348 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
350 dprintk(1, "Memory alloc for buffer struct failed\n");
354 /* Length stores number of planes for multiplanar buffers */
355 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
356 vb->v4l2_buf.length = num_planes;
358 vb->state = VB2_BUF_STATE_DEQUEUED;
360 vb->num_planes = num_planes;
361 vb->v4l2_buf.index = q->num_buffers + buffer;
362 vb->v4l2_buf.type = q->type;
363 vb->v4l2_buf.memory = memory;
365 /* Allocate video buffer memory for the MMAP type */
366 if (memory == V4L2_MEMORY_MMAP) {
367 ret = __vb2_buf_mem_alloc(vb);
369 dprintk(1, "Failed allocating memory for "
370 "buffer %d\n", buffer);
375 * Call the driver-provided buffer initialization
376 * callback, if given. An error in initialization
377 * results in queue setup failure.
379 ret = call_vb_qop(vb, buf_init, vb);
381 dprintk(1, "Buffer %d %p initialization"
382 " failed\n", buffer, vb);
383 __vb2_buf_mem_free(vb);
389 q->bufs[q->num_buffers + buffer] = vb;
392 __setup_lengths(q, buffer);
393 if (memory == V4L2_MEMORY_MMAP)
394 __setup_offsets(q, buffer);
396 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
403 * __vb2_free_mem() - release all video buffer memory for a given queue
405 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
408 struct vb2_buffer *vb;
410 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
412 vb = q->bufs[buffer];
416 /* Free MMAP buffers or release USERPTR buffers */
417 if (q->memory == V4L2_MEMORY_MMAP)
418 __vb2_buf_mem_free(vb);
419 else if (q->memory == V4L2_MEMORY_DMABUF)
420 __vb2_buf_dmabuf_put(vb);
422 __vb2_buf_userptr_put(vb);
427 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
428 * related information, if no buffers are left return the queue to an
429 * uninitialized state. Might be called even if the queue has already been freed.
431 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
436 * Sanity check: when preparing a buffer the queue lock is released for
437 * a short while (see __buf_prepare for the details), which would allow
438 * a race with a reqbufs which can call this function. Removing the
439 * buffers from underneath __buf_prepare is obviously a bad idea, so we
440 * check if any of the buffers is in the state PREPARING, and if so we
441 * just return -EAGAIN.
443 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
445 if (q->bufs[buffer] == NULL)
447 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
448 dprintk(1, "preparing buffers, cannot free\n");
453 /* Call driver-provided cleanup function for each buffer, if provided */
454 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
456 struct vb2_buffer *vb = q->bufs[buffer];
458 if (vb && vb->planes[0].mem_priv)
459 call_void_vb_qop(vb, buf_cleanup, vb);
462 /* Release video buffer memory */
463 __vb2_free_mem(q, buffers);
465 #ifdef CONFIG_VIDEO_ADV_DEBUG
467 * Check that all the calls were balances during the life-time of this
468 * queue. If not (or if the debug level is 1 or up), then dump the
469 * counters to the kernel log.
471 if (q->num_buffers) {
472 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
473 q->cnt_wait_prepare != q->cnt_wait_finish;
475 if (unbalanced || debug) {
476 pr_info("vb2: counters for queue %p:%s\n", q,
477 unbalanced ? " UNBALANCED!" : "");
478 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
479 q->cnt_queue_setup, q->cnt_start_streaming,
480 q->cnt_stop_streaming);
481 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
482 q->cnt_wait_prepare, q->cnt_wait_finish);
484 q->cnt_queue_setup = 0;
485 q->cnt_wait_prepare = 0;
486 q->cnt_wait_finish = 0;
487 q->cnt_start_streaming = 0;
488 q->cnt_stop_streaming = 0;
490 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
491 struct vb2_buffer *vb = q->bufs[buffer];
492 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
493 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
494 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
495 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
496 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
497 vb->cnt_buf_queue != vb->cnt_buf_done ||
498 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
499 vb->cnt_buf_init != vb->cnt_buf_cleanup;
501 if (unbalanced || debug) {
502 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
503 q, buffer, unbalanced ? " UNBALANCED!" : "");
504 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
505 vb->cnt_buf_init, vb->cnt_buf_cleanup,
506 vb->cnt_buf_prepare, vb->cnt_buf_finish);
507 pr_info("vb2: buf_queue: %u buf_done: %u\n",
508 vb->cnt_buf_queue, vb->cnt_buf_done);
509 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
510 vb->cnt_mem_alloc, vb->cnt_mem_put,
511 vb->cnt_mem_prepare, vb->cnt_mem_finish,
513 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
514 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
515 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
516 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
517 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
518 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
519 vb->cnt_mem_get_dmabuf,
520 vb->cnt_mem_num_users,
527 /* Free videobuf buffers */
528 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
530 kfree(q->bufs[buffer]);
531 q->bufs[buffer] = NULL;
534 q->num_buffers -= buffers;
535 if (!q->num_buffers) {
537 INIT_LIST_HEAD(&q->queued_list);
543 * __verify_planes_array() - verify that the planes array passed in struct
544 * v4l2_buffer from userspace can be safely used
546 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
548 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
551 /* Is memory for copying plane information present? */
552 if (NULL == b->m.planes) {
553 dprintk(1, "Multi-planar buffer passed but "
554 "planes array not provided\n");
558 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
559 dprintk(1, "Incorrect planes array length, "
560 "expected %d, got %d\n", vb->num_planes, b->length);
568 * __verify_length() - Verify that the bytesused value for each plane fits in
569 * the plane length and that the data offset doesn't exceed the bytesused value.
571 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
576 if (!V4L2_TYPE_IS_OUTPUT(b->type))
579 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
580 for (plane = 0; plane < vb->num_planes; ++plane) {
581 length = (b->memory == V4L2_MEMORY_USERPTR)
582 ? b->m.planes[plane].length
583 : vb->v4l2_planes[plane].length;
585 if (b->m.planes[plane].bytesused > length)
588 if (b->m.planes[plane].data_offset > 0 &&
589 b->m.planes[plane].data_offset >=
590 b->m.planes[plane].bytesused)
594 length = (b->memory == V4L2_MEMORY_USERPTR)
595 ? b->length : vb->v4l2_planes[0].length;
597 if (b->bytesused > length)
605 * __buffer_in_use() - return true if the buffer is in use and
606 * the queue cannot be freed (by the means of REQBUFS(0)) call
608 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
611 for (plane = 0; plane < vb->num_planes; ++plane) {
612 void *mem_priv = vb->planes[plane].mem_priv;
614 * If num_users() has not been provided, call_memop
615 * will return 0, apparently nobody cares about this
616 * case anyway. If num_users() returns more than 1,
617 * we are not the only user of the plane's memory.
619 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
626 * __buffers_in_use() - return true if any buffers on the queue are in use and
627 * the queue cannot be freed (by the means of REQBUFS(0)) call
629 static bool __buffers_in_use(struct vb2_queue *q)
632 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
633 if (__buffer_in_use(q, q->bufs[buffer]))
640 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
641 * returned to userspace
643 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
645 struct vb2_queue *q = vb->vb2_queue;
647 /* Copy back data such as timestamp, flags, etc. */
648 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
649 b->reserved2 = vb->v4l2_buf.reserved2;
650 b->reserved = vb->v4l2_buf.reserved;
652 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
654 * Fill in plane-related data if userspace provided an array
655 * for it. The caller has already verified memory and size.
657 b->length = vb->num_planes;
658 memcpy(b->m.planes, vb->v4l2_planes,
659 b->length * sizeof(struct v4l2_plane));
662 * We use length and offset in v4l2_planes array even for
663 * single-planar buffers, but userspace does not.
665 b->length = vb->v4l2_planes[0].length;
666 b->bytesused = vb->v4l2_planes[0].bytesused;
667 if (q->memory == V4L2_MEMORY_MMAP)
668 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
669 else if (q->memory == V4L2_MEMORY_USERPTR)
670 b->m.userptr = vb->v4l2_planes[0].m.userptr;
671 else if (q->memory == V4L2_MEMORY_DMABUF)
672 b->m.fd = vb->v4l2_planes[0].m.fd;
676 * Clear any buffer state related flags.
678 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
679 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
680 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
681 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
683 * For non-COPY timestamps, drop timestamp source bits
684 * and obtain the timestamp source from the queue.
686 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
687 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
691 case VB2_BUF_STATE_QUEUED:
692 case VB2_BUF_STATE_ACTIVE:
693 b->flags |= V4L2_BUF_FLAG_QUEUED;
695 case VB2_BUF_STATE_ERROR:
696 b->flags |= V4L2_BUF_FLAG_ERROR;
698 case VB2_BUF_STATE_DONE:
699 b->flags |= V4L2_BUF_FLAG_DONE;
701 case VB2_BUF_STATE_PREPARED:
702 b->flags |= V4L2_BUF_FLAG_PREPARED;
704 case VB2_BUF_STATE_PREPARING:
705 case VB2_BUF_STATE_DEQUEUED:
710 if (__buffer_in_use(q, vb))
711 b->flags |= V4L2_BUF_FLAG_MAPPED;
715 * vb2_querybuf() - query video buffer information
717 * @b: buffer struct passed from userspace to vidioc_querybuf handler
720 * Should be called from vidioc_querybuf ioctl handler in driver.
721 * This function will verify the passed v4l2_buffer structure and fill the
722 * relevant information for the userspace.
724 * The return values from this function are intended to be directly returned
725 * from vidioc_querybuf handler in driver.
727 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
729 struct vb2_buffer *vb;
732 if (b->type != q->type) {
733 dprintk(1, "wrong buffer type\n");
737 if (b->index >= q->num_buffers) {
738 dprintk(1, "buffer index out of range\n");
741 vb = q->bufs[b->index];
742 ret = __verify_planes_array(vb, b);
744 __fill_v4l2_buffer(vb, b);
747 EXPORT_SYMBOL(vb2_querybuf);
750 * __verify_userptr_ops() - verify that all memory operations required for
751 * USERPTR queue type have been provided
753 static int __verify_userptr_ops(struct vb2_queue *q)
755 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
756 !q->mem_ops->put_userptr)
763 * __verify_mmap_ops() - verify that all memory operations required for
764 * MMAP queue type have been provided
766 static int __verify_mmap_ops(struct vb2_queue *q)
768 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
769 !q->mem_ops->put || !q->mem_ops->mmap)
776 * __verify_dmabuf_ops() - verify that all memory operations required for
777 * DMABUF queue type have been provided
779 static int __verify_dmabuf_ops(struct vb2_queue *q)
781 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
782 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
783 !q->mem_ops->unmap_dmabuf)
790 * __verify_memory_type() - Check whether the memory type and buffer type
791 * passed to a buffer operation are compatible with the queue.
793 static int __verify_memory_type(struct vb2_queue *q,
794 enum v4l2_memory memory, enum v4l2_buf_type type)
796 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
797 memory != V4L2_MEMORY_DMABUF) {
798 dprintk(1, "unsupported memory type\n");
802 if (type != q->type) {
803 dprintk(1, "requested type is incorrect\n");
808 * Make sure all the required memory ops for given memory type
811 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
812 dprintk(1, "MMAP for current setup unsupported\n");
816 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
817 dprintk(1, "USERPTR for current setup unsupported\n");
821 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
822 dprintk(1, "DMABUF for current setup unsupported\n");
827 * Place the busy tests at the end: -EBUSY can be ignored when
828 * create_bufs is called with count == 0, but count == 0 should still
829 * do the memory and type validation.
832 dprintk(1, "file io in progress\n");
839 * __reqbufs() - Initiate streaming
840 * @q: videobuf2 queue
841 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
843 * Should be called from vidioc_reqbufs ioctl handler of a driver.
845 * 1) verifies streaming parameters passed from the userspace,
846 * 2) sets up the queue,
847 * 3) negotiates number of buffers and planes per buffer with the driver
848 * to be used during streaming,
849 * 4) allocates internal buffer structures (struct vb2_buffer), according to
850 * the agreed parameters,
851 * 5) for MMAP memory type, allocates actual video memory, using the
852 * memory handling/allocation routines provided during queue initialization
854 * If req->count is 0, all the memory will be freed instead.
855 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
856 * and the queue is not busy, memory will be reallocated.
858 * The return values from this function are intended to be directly returned
859 * from vidioc_reqbufs handler in driver.
861 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
863 unsigned int num_buffers, allocated_buffers, num_planes = 0;
867 dprintk(1, "streaming active\n");
871 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
873 * We already have buffers allocated, so first check if they
874 * are not in use and can be freed.
876 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
877 dprintk(1, "memory in use, cannot free\n");
882 * Call queue_cancel to clean up any buffers in the PREPARED or
883 * QUEUED state which is possible if buffers were prepared or
884 * queued without ever calling STREAMON.
886 __vb2_queue_cancel(q);
887 ret = __vb2_queue_free(q, q->num_buffers);
892 * In case of REQBUFS(0) return immediately without calling
893 * driver's queue_setup() callback and allocating resources.
900 * Make sure the requested values and current defaults are sane.
902 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
903 num_buffers = max_t(unsigned int, req->count, q->min_buffers_needed);
904 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
905 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
906 q->memory = req->memory;
909 * Ask the driver how many buffers and planes per buffer it requires.
910 * Driver also sets the size and allocator context for each plane.
912 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
913 q->plane_sizes, q->alloc_ctx);
917 /* Finally, allocate buffers and video memory */
918 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
919 if (allocated_buffers == 0) {
920 dprintk(1, "Memory allocation failed\n");
925 * There is no point in continuing if we can't allocate the minimum
926 * number of buffers needed by this vb2_queue.
928 if (allocated_buffers < q->min_buffers_needed)
932 * Check if driver can handle the allocated number of buffers.
934 if (!ret && allocated_buffers < num_buffers) {
935 num_buffers = allocated_buffers;
937 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
938 &num_planes, q->plane_sizes, q->alloc_ctx);
940 if (!ret && allocated_buffers < num_buffers)
944 * Either the driver has accepted a smaller number of buffers,
945 * or .queue_setup() returned an error
949 q->num_buffers = allocated_buffers;
953 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
954 * from q->num_buffers.
956 __vb2_queue_free(q, allocated_buffers);
961 * Return the number of successfully allocated buffers
964 req->count = allocated_buffers;
970 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
972 * @q: videobuf2 queue
973 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
975 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
977 int ret = __verify_memory_type(q, req->memory, req->type);
979 return ret ? ret : __reqbufs(q, req);
981 EXPORT_SYMBOL_GPL(vb2_reqbufs);
984 * __create_bufs() - Allocate buffers and any required auxiliary structs
985 * @q: videobuf2 queue
986 * @create: creation parameters, passed from userspace to vidioc_create_bufs
989 * Should be called from vidioc_create_bufs ioctl handler of a driver.
991 * 1) verifies parameter sanity
992 * 2) calls the .queue_setup() queue operation
993 * 3) performs any necessary memory allocations
995 * The return values from this function are intended to be directly returned
996 * from vidioc_create_bufs handler in driver.
998 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1000 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1003 if (q->num_buffers == VIDEO_MAX_FRAME) {
1004 dprintk(1, "maximum number of buffers already allocated\n");
1008 if (!q->num_buffers) {
1009 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1010 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1011 q->memory = create->memory;
1014 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1017 * Ask the driver, whether the requested number of buffers, planes per
1018 * buffer and their sizes are acceptable
1020 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1021 &num_planes, q->plane_sizes, q->alloc_ctx);
1025 /* Finally, allocate buffers and video memory */
1026 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1028 if (allocated_buffers == 0) {
1029 dprintk(1, "Memory allocation failed\n");
1034 * Check if driver can handle the so far allocated number of buffers.
1036 if (allocated_buffers < num_buffers) {
1037 num_buffers = allocated_buffers;
1040 * q->num_buffers contains the total number of buffers, that the
1041 * queue driver has set up
1043 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1044 &num_planes, q->plane_sizes, q->alloc_ctx);
1046 if (!ret && allocated_buffers < num_buffers)
1050 * Either the driver has accepted a smaller number of buffers,
1051 * or .queue_setup() returned an error
1055 q->num_buffers += allocated_buffers;
1059 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1060 * from q->num_buffers.
1062 __vb2_queue_free(q, allocated_buffers);
1067 * Return the number of successfully allocated buffers
1070 create->count = allocated_buffers;
1076 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1077 * memory and type values.
1078 * @q: videobuf2 queue
1079 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1082 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1084 int ret = __verify_memory_type(q, create->memory, create->format.type);
1086 create->index = q->num_buffers;
1087 if (create->count == 0)
1088 return ret != -EBUSY ? ret : 0;
1089 return ret ? ret : __create_bufs(q, create);
1091 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1094 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1095 * @vb: vb2_buffer to which the plane in question belongs to
1096 * @plane_no: plane number for which the address is to be returned
1098 * This function returns a kernel virtual address of a given plane if
1099 * such a mapping exist, NULL otherwise.
1101 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1103 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1106 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1109 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1112 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1113 * @vb: vb2_buffer to which the plane in question belongs to
1114 * @plane_no: plane number for which the cookie is to be returned
1116 * This function returns an allocator specific cookie for a given plane if
1117 * available, NULL otherwise. The allocator should provide some simple static
1118 * inline function, which would convert this cookie to the allocator specific
1119 * type that can be used directly by the driver to access the buffer. This can
1120 * be for example physical address, pointer to scatter list or IOMMU mapping.
1122 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1124 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1127 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1129 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1132 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1133 * @vb: vb2_buffer returned from the driver
1134 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1135 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1136 * If start_streaming fails then it should return buffers with state
1137 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1139 * This function should be called by the driver after a hardware operation on
1140 * a buffer is finished and the buffer may be returned to userspace. The driver
1141 * cannot use this buffer anymore until it is queued back to it by videobuf
1142 * by the means of buf_queue callback. Only buffers previously queued to the
1143 * driver by buf_queue can be passed to this function.
1145 * While streaming a buffer can only be returned in state DONE or ERROR.
1146 * The start_streaming op can also return them in case the DMA engine cannot
1147 * be started for some reason. In that case the buffers should be returned with
1150 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1152 struct vb2_queue *q = vb->vb2_queue;
1153 unsigned long flags;
1156 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1159 if (!q->start_streaming_called) {
1160 if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
1161 state = VB2_BUF_STATE_QUEUED;
1162 } else if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1163 state != VB2_BUF_STATE_ERROR)) {
1164 state = VB2_BUF_STATE_ERROR;
1167 #ifdef CONFIG_VIDEO_ADV_DEBUG
1169 * Although this is not a callback, it still does have to balance
1170 * with the buf_queue op. So update this counter manually.
1174 dprintk(4, "Done processing on buffer %d, state: %d\n",
1175 vb->v4l2_buf.index, state);
1178 for (plane = 0; plane < vb->num_planes; ++plane)
1179 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1181 /* Add the buffer to the done buffers list */
1182 spin_lock_irqsave(&q->done_lock, flags);
1184 if (state != VB2_BUF_STATE_QUEUED)
1185 list_add_tail(&vb->done_entry, &q->done_list);
1186 atomic_dec(&q->owned_by_drv_count);
1187 spin_unlock_irqrestore(&q->done_lock, flags);
1189 if (state == VB2_BUF_STATE_QUEUED)
1192 /* Inform any processes that may be waiting for buffers */
1193 wake_up(&q->done_wq);
1195 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1198 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1199 * v4l2_buffer by the userspace. The caller has already verified that struct
1200 * v4l2_buffer has a valid number of planes.
1202 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1203 struct v4l2_plane *v4l2_planes)
1207 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1208 /* Fill in driver-provided information for OUTPUT types */
1209 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1210 bool bytesused_is_used;
1212 /* Check if bytesused == 0 for all planes */
1213 for (plane = 0; plane < vb->num_planes; ++plane)
1214 if (b->m.planes[plane].bytesused)
1216 bytesused_is_used = plane < vb->num_planes;
1219 * Will have to go up to b->length when API starts
1220 * accepting variable number of planes.
1222 * If bytesused_is_used is false, then fall back to the
1223 * full buffer size. In that case userspace clearly
1224 * never bothered to set it and it's a safe assumption
1225 * that they really meant to use the full plane sizes.
1227 for (plane = 0; plane < vb->num_planes; ++plane) {
1228 struct v4l2_plane *pdst = &v4l2_planes[plane];
1229 struct v4l2_plane *psrc = &b->m.planes[plane];
1231 pdst->bytesused = bytesused_is_used ?
1232 psrc->bytesused : psrc->length;
1233 pdst->data_offset = psrc->data_offset;
1237 if (b->memory == V4L2_MEMORY_USERPTR) {
1238 for (plane = 0; plane < vb->num_planes; ++plane) {
1239 v4l2_planes[plane].m.userptr =
1240 b->m.planes[plane].m.userptr;
1241 v4l2_planes[plane].length =
1242 b->m.planes[plane].length;
1245 if (b->memory == V4L2_MEMORY_DMABUF) {
1246 for (plane = 0; plane < vb->num_planes; ++plane) {
1247 v4l2_planes[plane].m.fd =
1248 b->m.planes[plane].m.fd;
1249 v4l2_planes[plane].length =
1250 b->m.planes[plane].length;
1255 * Single-planar buffers do not use planes array,
1256 * so fill in relevant v4l2_buffer struct fields instead.
1257 * In videobuf we use our internal V4l2_planes struct for
1258 * single-planar buffers as well, for simplicity.
1260 * If bytesused == 0, then fall back to the full buffer size
1261 * as that's a sensible default.
1263 if (V4L2_TYPE_IS_OUTPUT(b->type))
1264 v4l2_planes[0].bytesused =
1265 b->bytesused ? b->bytesused : b->length;
1267 v4l2_planes[0].bytesused = 0;
1269 if (b->memory == V4L2_MEMORY_USERPTR) {
1270 v4l2_planes[0].m.userptr = b->m.userptr;
1271 v4l2_planes[0].length = b->length;
1274 if (b->memory == V4L2_MEMORY_DMABUF) {
1275 v4l2_planes[0].m.fd = b->m.fd;
1276 v4l2_planes[0].length = b->length;
1280 /* Zero flags that the vb2 core handles */
1281 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1282 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1283 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1285 * Non-COPY timestamps and non-OUTPUT queues will get
1286 * their timestamp and timestamp source flags from the
1289 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1292 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1294 * For output buffers mask out the timecode flag:
1295 * this will be handled later in vb2_internal_qbuf().
1296 * The 'field' is valid metadata for this output buffer
1297 * and so that needs to be copied here.
1299 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1300 vb->v4l2_buf.field = b->field;
1302 /* Zero any output buffer flags as this is a capture buffer */
1303 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1308 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1310 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1312 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1313 return call_vb_qop(vb, buf_prepare, vb);
1317 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1319 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1321 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1322 struct vb2_queue *q = vb->vb2_queue;
1326 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1327 bool reacquired = vb->planes[0].mem_priv == NULL;
1329 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1330 /* Copy relevant information provided by the userspace */
1331 __fill_vb2_buffer(vb, b, planes);
1333 for (plane = 0; plane < vb->num_planes; ++plane) {
1334 /* Skip the plane if already verified */
1335 if (vb->v4l2_planes[plane].m.userptr &&
1336 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1337 && vb->v4l2_planes[plane].length == planes[plane].length)
1340 dprintk(3, "userspace address for plane %d changed, "
1341 "reacquiring memory\n", plane);
1343 /* Check if the provided plane buffer is large enough */
1344 if (planes[plane].length < q->plane_sizes[plane]) {
1345 dprintk(1, "provided buffer size %u is less than "
1346 "setup size %u for plane %d\n",
1347 planes[plane].length,
1348 q->plane_sizes[plane], plane);
1353 /* Release previously acquired memory if present */
1354 if (vb->planes[plane].mem_priv) {
1357 call_void_vb_qop(vb, buf_cleanup, vb);
1359 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1362 vb->planes[plane].mem_priv = NULL;
1363 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1365 /* Acquire each plane's memory */
1366 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1367 planes[plane].m.userptr,
1368 planes[plane].length, write);
1369 if (IS_ERR_OR_NULL(mem_priv)) {
1370 dprintk(1, "failed acquiring userspace "
1371 "memory for plane %d\n", plane);
1372 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1375 vb->planes[plane].mem_priv = mem_priv;
1379 * Now that everything is in order, copy relevant information
1380 * provided by userspace.
1382 for (plane = 0; plane < vb->num_planes; ++plane)
1383 vb->v4l2_planes[plane] = planes[plane];
1387 * One or more planes changed, so we must call buf_init to do
1388 * the driver-specific initialization on the newly acquired
1389 * buffer, if provided.
1391 ret = call_vb_qop(vb, buf_init, vb);
1393 dprintk(1, "buffer initialization failed\n");
1398 ret = call_vb_qop(vb, buf_prepare, vb);
1400 dprintk(1, "buffer preparation failed\n");
1401 call_void_vb_qop(vb, buf_cleanup, vb);
1407 /* In case of errors, release planes that were already acquired */
1408 for (plane = 0; plane < vb->num_planes; ++plane) {
1409 if (vb->planes[plane].mem_priv)
1410 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1411 vb->planes[plane].mem_priv = NULL;
1412 vb->v4l2_planes[plane].m.userptr = 0;
1413 vb->v4l2_planes[plane].length = 0;
1420 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1422 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1424 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1425 struct vb2_queue *q = vb->vb2_queue;
1429 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1430 bool reacquired = vb->planes[0].mem_priv == NULL;
1432 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1433 /* Copy relevant information provided by the userspace */
1434 __fill_vb2_buffer(vb, b, planes);
1436 for (plane = 0; plane < vb->num_planes; ++plane) {
1437 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1439 if (IS_ERR_OR_NULL(dbuf)) {
1440 dprintk(1, "invalid dmabuf fd for plane %d\n",
1446 /* use DMABUF size if length is not provided */
1447 if (planes[plane].length == 0)
1448 planes[plane].length = dbuf->size;
1450 if (planes[plane].length < q->plane_sizes[plane]) {
1451 dprintk(1, "invalid dmabuf length for plane %d\n",
1457 /* Skip the plane if already verified */
1458 if (dbuf == vb->planes[plane].dbuf &&
1459 vb->v4l2_planes[plane].length == planes[plane].length) {
1464 dprintk(1, "buffer for plane %d changed\n", plane);
1468 call_void_vb_qop(vb, buf_cleanup, vb);
1471 /* Release previously acquired memory if present */
1472 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1473 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1475 /* Acquire each plane's memory */
1476 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1477 dbuf, planes[plane].length, write);
1478 if (IS_ERR(mem_priv)) {
1479 dprintk(1, "failed to attach dmabuf\n");
1480 ret = PTR_ERR(mem_priv);
1485 vb->planes[plane].dbuf = dbuf;
1486 vb->planes[plane].mem_priv = mem_priv;
1489 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1490 * really we want to do this just before the DMA, not while queueing
1493 for (plane = 0; plane < vb->num_planes; ++plane) {
1494 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1496 dprintk(1, "failed to map dmabuf for plane %d\n",
1500 vb->planes[plane].dbuf_mapped = 1;
1504 * Now that everything is in order, copy relevant information
1505 * provided by userspace.
1507 for (plane = 0; plane < vb->num_planes; ++plane)
1508 vb->v4l2_planes[plane] = planes[plane];
1512 * Call driver-specific initialization on the newly acquired buffer,
1515 ret = call_vb_qop(vb, buf_init, vb);
1517 dprintk(1, "buffer initialization failed\n");
1522 ret = call_vb_qop(vb, buf_prepare, vb);
1524 dprintk(1, "buffer preparation failed\n");
1525 call_void_vb_qop(vb, buf_cleanup, vb);
1531 /* In case of errors, release planes that were already acquired */
1532 __vb2_buf_dmabuf_put(vb);
1538 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1540 static void __enqueue_in_driver(struct vb2_buffer *vb)
1542 struct vb2_queue *q = vb->vb2_queue;
1545 vb->state = VB2_BUF_STATE_ACTIVE;
1546 atomic_inc(&q->owned_by_drv_count);
1549 for (plane = 0; plane < vb->num_planes; ++plane)
1550 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1552 call_void_vb_qop(vb, buf_queue, vb);
1555 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1557 struct vb2_queue *q = vb->vb2_queue;
1558 struct rw_semaphore *mmap_sem;
1561 ret = __verify_length(vb, b);
1563 dprintk(1, "plane parameters verification failed: %d\n", ret);
1566 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1568 * If the format's field is ALTERNATE, then the buffer's field
1569 * should be either TOP or BOTTOM, not ALTERNATE since that
1570 * makes no sense. The driver has to know whether the
1571 * buffer represents a top or a bottom field in order to
1572 * program any DMA correctly. Using ALTERNATE is wrong, since
1573 * that just says that it is either a top or a bottom field,
1574 * but not which of the two it is.
1576 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1580 vb->state = VB2_BUF_STATE_PREPARING;
1581 vb->v4l2_buf.timestamp.tv_sec = 0;
1582 vb->v4l2_buf.timestamp.tv_usec = 0;
1583 vb->v4l2_buf.sequence = 0;
1585 switch (q->memory) {
1586 case V4L2_MEMORY_MMAP:
1587 ret = __qbuf_mmap(vb, b);
1589 case V4L2_MEMORY_USERPTR:
1591 * In case of user pointer buffers vb2 allocators need to get
1592 * direct access to userspace pages. This requires getting
1593 * the mmap semaphore for read access in the current process
1594 * structure. The same semaphore is taken before calling mmap
1595 * operation, while both qbuf/prepare_buf and mmap are called
1596 * by the driver or v4l2 core with the driver's lock held.
1597 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1598 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1599 * the videobuf2 core releases the driver's lock, takes
1600 * mmap_sem and then takes the driver's lock again.
1602 mmap_sem = ¤t->mm->mmap_sem;
1603 call_void_qop(q, wait_prepare, q);
1604 down_read(mmap_sem);
1605 call_void_qop(q, wait_finish, q);
1607 ret = __qbuf_userptr(vb, b);
1611 case V4L2_MEMORY_DMABUF:
1612 ret = __qbuf_dmabuf(vb, b);
1615 WARN(1, "Invalid queue type\n");
1620 dprintk(1, "buffer preparation failed: %d\n", ret);
1621 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1626 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1629 if (b->type != q->type) {
1630 dprintk(1, "%s: invalid buffer type\n", opname);
1634 if (b->index >= q->num_buffers) {
1635 dprintk(1, "%s: buffer index out of range\n", opname);
1639 if (q->bufs[b->index] == NULL) {
1640 /* Should never happen */
1641 dprintk(1, "%s: buffer is NULL\n", opname);
1645 if (b->memory != q->memory) {
1646 dprintk(1, "%s: invalid memory type\n", opname);
1650 return __verify_planes_array(q->bufs[b->index], b);
1654 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1655 * @q: videobuf2 queue
1656 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1659 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1661 * 1) verifies the passed buffer,
1662 * 2) calls buf_prepare callback in the driver (if provided), in which
1663 * driver-specific buffer initialization can be performed,
1665 * The return values from this function are intended to be directly returned
1666 * from vidioc_prepare_buf handler in driver.
1668 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1670 struct vb2_buffer *vb;
1674 dprintk(1, "file io in progress\n");
1678 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1682 vb = q->bufs[b->index];
1683 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1684 dprintk(1, "invalid buffer state %d\n",
1689 ret = __buf_prepare(vb, b);
1691 /* Fill buffer information for the userspace */
1692 __fill_v4l2_buffer(vb, b);
1694 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1698 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1701 * vb2_start_streaming() - Attempt to start streaming.
1702 * @q: videobuf2 queue
1704 * Attempt to start streaming. When this function is called there must be
1705 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1706 * number of buffers required for the DMA engine to function). If the
1707 * @start_streaming op fails it is supposed to return all the driver-owned
1708 * buffers back to vb2 in state QUEUED. Check if that happened and if
1709 * not warn and reclaim them forcefully.
1711 static int vb2_start_streaming(struct vb2_queue *q)
1713 struct vb2_buffer *vb;
1717 * If any buffers were queued before streamon,
1718 * we can now pass them to driver for processing.
1720 list_for_each_entry(vb, &q->queued_list, queued_entry)
1721 __enqueue_in_driver(vb);
1723 /* Tell the driver to start streaming */
1724 ret = call_qop(q, start_streaming, q,
1725 atomic_read(&q->owned_by_drv_count));
1726 q->start_streaming_called = ret == 0;
1730 dprintk(1, "driver refused to start streaming\n");
1731 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1735 * Forcefully reclaim buffers if the driver did not
1736 * correctly return them to vb2.
1738 for (i = 0; i < q->num_buffers; ++i) {
1740 if (vb->state == VB2_BUF_STATE_ACTIVE)
1741 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1743 /* Must be zero now */
1744 WARN_ON(atomic_read(&q->owned_by_drv_count));
1749 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1751 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1752 struct vb2_buffer *vb;
1757 vb = q->bufs[b->index];
1759 switch (vb->state) {
1760 case VB2_BUF_STATE_DEQUEUED:
1761 ret = __buf_prepare(vb, b);
1765 case VB2_BUF_STATE_PREPARED:
1767 case VB2_BUF_STATE_PREPARING:
1768 dprintk(1, "buffer still being prepared\n");
1771 dprintk(1, "invalid buffer state %d\n", vb->state);
1776 * Add to the queued buffers list, a buffer will stay on it until
1777 * dequeued in dqbuf.
1779 list_add_tail(&vb->queued_entry, &q->queued_list);
1781 vb->state = VB2_BUF_STATE_QUEUED;
1782 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1784 * For output buffers copy the timestamp if needed,
1785 * and the timecode field and flag if needed.
1787 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1788 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1789 vb->v4l2_buf.timestamp = b->timestamp;
1790 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1791 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1792 vb->v4l2_buf.timecode = b->timecode;
1796 * If already streaming, give the buffer to driver for processing.
1797 * If not, the buffer will be given to driver on next streamon.
1799 if (q->start_streaming_called)
1800 __enqueue_in_driver(vb);
1802 /* Fill buffer information for the userspace */
1803 __fill_v4l2_buffer(vb, b);
1806 * If streamon has been called, and we haven't yet called
1807 * start_streaming() since not enough buffers were queued, and
1808 * we now have reached the minimum number of queued buffers,
1809 * then we can finally call start_streaming().
1811 if (q->streaming && !q->start_streaming_called &&
1812 q->queued_count >= q->min_buffers_needed) {
1813 ret = vb2_start_streaming(q);
1818 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1823 * vb2_qbuf() - Queue a buffer from userspace
1824 * @q: videobuf2 queue
1825 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1828 * Should be called from vidioc_qbuf ioctl handler of a driver.
1830 * 1) verifies the passed buffer,
1831 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1832 * which driver-specific buffer initialization can be performed,
1833 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1834 * callback for processing.
1836 * The return values from this function are intended to be directly returned
1837 * from vidioc_qbuf handler in driver.
1839 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1842 dprintk(1, "file io in progress\n");
1846 return vb2_internal_qbuf(q, b);
1848 EXPORT_SYMBOL_GPL(vb2_qbuf);
1851 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1854 * Will sleep if required for nonblocking == false.
1856 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1859 * All operations on vb_done_list are performed under done_lock
1860 * spinlock protection. However, buffers may be removed from
1861 * it and returned to userspace only while holding both driver's
1862 * lock and the done_lock spinlock. Thus we can be sure that as
1863 * long as we hold the driver's lock, the list will remain not
1864 * empty if list_empty() check succeeds.
1870 if (!q->streaming) {
1871 dprintk(1, "Streaming off, will not wait for buffers\n");
1875 if (!list_empty(&q->done_list)) {
1877 * Found a buffer that we were waiting for.
1883 dprintk(1, "Nonblocking and no buffers to dequeue, "
1889 * We are streaming and blocking, wait for another buffer to
1890 * become ready or for streamoff. Driver's lock is released to
1891 * allow streamoff or qbuf to be called while waiting.
1893 call_void_qop(q, wait_prepare, q);
1896 * All locks have been released, it is safe to sleep now.
1898 dprintk(3, "Will sleep waiting for buffers\n");
1899 ret = wait_event_interruptible(q->done_wq,
1900 !list_empty(&q->done_list) || !q->streaming);
1903 * We need to reevaluate both conditions again after reacquiring
1904 * the locks or return an error if one occurred.
1906 call_void_qop(q, wait_finish, q);
1908 dprintk(1, "Sleep was interrupted\n");
1916 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1918 * Will sleep if required for nonblocking == false.
1920 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1921 struct v4l2_buffer *b, int nonblocking)
1923 unsigned long flags;
1927 * Wait for at least one buffer to become available on the done_list.
1929 ret = __vb2_wait_for_done_vb(q, nonblocking);
1934 * Driver's lock has been held since we last verified that done_list
1935 * is not empty, so no need for another list_empty(done_list) check.
1937 spin_lock_irqsave(&q->done_lock, flags);
1938 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1940 * Only remove the buffer from done_list if v4l2_buffer can handle all
1943 ret = __verify_planes_array(*vb, b);
1945 list_del(&(*vb)->done_entry);
1946 spin_unlock_irqrestore(&q->done_lock, flags);
1952 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1953 * @q: videobuf2 queue
1955 * This function will wait until all buffers that have been given to the driver
1956 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1957 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1958 * taken, for example from stop_streaming() callback.
1960 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1962 if (!q->streaming) {
1963 dprintk(1, "Streaming off, will not wait for buffers\n");
1967 if (q->start_streaming_called)
1968 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1971 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1974 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1976 static void __vb2_dqbuf(struct vb2_buffer *vb)
1978 struct vb2_queue *q = vb->vb2_queue;
1981 /* nothing to do if the buffer is already dequeued */
1982 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1985 vb->state = VB2_BUF_STATE_DEQUEUED;
1987 /* unmap DMABUF buffer */
1988 if (q->memory == V4L2_MEMORY_DMABUF)
1989 for (i = 0; i < vb->num_planes; ++i) {
1990 if (!vb->planes[i].dbuf_mapped)
1992 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1993 vb->planes[i].dbuf_mapped = 0;
1997 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1999 struct vb2_buffer *vb = NULL;
2002 if (b->type != q->type) {
2003 dprintk(1, "invalid buffer type\n");
2006 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2010 switch (vb->state) {
2011 case VB2_BUF_STATE_DONE:
2012 dprintk(3, "Returning done buffer\n");
2014 case VB2_BUF_STATE_ERROR:
2015 dprintk(3, "Returning done buffer with errors\n");
2018 dprintk(1, "Invalid buffer state\n");
2022 call_void_vb_qop(vb, buf_finish, vb);
2024 /* Fill buffer information for the userspace */
2025 __fill_v4l2_buffer(vb, b);
2026 /* Remove from videobuf queue */
2027 list_del(&vb->queued_entry);
2029 /* go back to dequeued state */
2032 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2033 vb->v4l2_buf.index, vb->state);
2039 * vb2_dqbuf() - Dequeue a buffer to the userspace
2040 * @q: videobuf2 queue
2041 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2043 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2044 * buffers ready for dequeuing are present. Normally the driver
2045 * would be passing (file->f_flags & O_NONBLOCK) here
2047 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2049 * 1) verifies the passed buffer,
2050 * 2) calls buf_finish callback in the driver (if provided), in which
2051 * driver can perform any additional operations that may be required before
2052 * returning the buffer to userspace, such as cache sync,
2053 * 3) the buffer struct members are filled with relevant information for
2056 * The return values from this function are intended to be directly returned
2057 * from vidioc_dqbuf handler in driver.
2059 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2062 dprintk(1, "file io in progress\n");
2065 return vb2_internal_dqbuf(q, b, nonblocking);
2067 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2070 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2072 * Removes all queued buffers from driver's queue and all buffers queued by
2073 * userspace from videobuf's queue. Returns to state after reqbufs.
2075 static void __vb2_queue_cancel(struct vb2_queue *q)
2080 * Tell driver to stop all transactions and release all queued
2083 if (q->start_streaming_called)
2084 call_qop(q, stop_streaming, q);
2086 q->start_streaming_called = 0;
2087 q->queued_count = 0;
2089 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2090 for (i = 0; i < q->num_buffers; ++i)
2091 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2092 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2093 /* Must be zero now */
2094 WARN_ON(atomic_read(&q->owned_by_drv_count));
2098 * Remove all buffers from videobuf's list...
2100 INIT_LIST_HEAD(&q->queued_list);
2102 * ...and done list; userspace will not receive any buffers it
2103 * has not already dequeued before initiating cancel.
2105 INIT_LIST_HEAD(&q->done_list);
2106 atomic_set(&q->owned_by_drv_count, 0);
2107 wake_up_all(&q->done_wq);
2110 * Reinitialize all buffers for next use.
2111 * Make sure to call buf_finish for any queued buffers. Normally
2112 * that's done in dqbuf, but that's not going to happen when we
2113 * cancel the whole queue. Note: this code belongs here, not in
2114 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2115 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2116 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2118 for (i = 0; i < q->num_buffers; ++i) {
2119 struct vb2_buffer *vb = q->bufs[i];
2121 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2122 vb->state = VB2_BUF_STATE_PREPARED;
2123 call_void_vb_qop(vb, buf_finish, vb);
2129 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2133 if (type != q->type) {
2134 dprintk(1, "invalid stream type\n");
2139 dprintk(3, "already streaming\n");
2143 if (!q->num_buffers) {
2144 dprintk(1, "no buffers have been allocated\n");
2148 if (!q->num_buffers) {
2149 dprintk(1, "no buffers have been allocated\n");
2152 if (q->num_buffers < q->min_buffers_needed) {
2153 dprintk(1, "need at least %u allocated buffers\n",
2154 q->min_buffers_needed);
2159 * Tell driver to start streaming provided sufficient buffers
2162 if (q->queued_count >= q->min_buffers_needed) {
2163 ret = vb2_start_streaming(q);
2165 __vb2_queue_cancel(q);
2172 dprintk(3, "successful\n");
2177 * vb2_streamon - start streaming
2178 * @q: videobuf2 queue
2179 * @type: type argument passed from userspace to vidioc_streamon handler
2181 * Should be called from vidioc_streamon handler of a driver.
2183 * 1) verifies current state
2184 * 2) passes any previously queued buffers to the driver and starts streaming
2186 * The return values from this function are intended to be directly returned
2187 * from vidioc_streamon handler in the driver.
2189 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2192 dprintk(1, "file io in progress\n");
2195 return vb2_internal_streamon(q, type);
2197 EXPORT_SYMBOL_GPL(vb2_streamon);
2199 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2201 if (type != q->type) {
2202 dprintk(1, "invalid stream type\n");
2207 * Cancel will pause streaming and remove all buffers from the driver
2208 * and videobuf, effectively returning control over them to userspace.
2210 * Note that we do this even if q->streaming == 0: if you prepare or
2211 * queue buffers, and then call streamoff without ever having called
2212 * streamon, you would still expect those buffers to be returned to
2213 * their normal dequeued state.
2215 __vb2_queue_cancel(q);
2217 dprintk(3, "successful\n");
2222 * vb2_streamoff - stop streaming
2223 * @q: videobuf2 queue
2224 * @type: type argument passed from userspace to vidioc_streamoff handler
2226 * Should be called from vidioc_streamoff handler of a driver.
2228 * 1) verifies current state,
2229 * 2) stop streaming and dequeues any queued buffers, including those previously
2230 * passed to the driver (after waiting for the driver to finish).
2232 * This call can be used for pausing playback.
2233 * The return values from this function are intended to be directly returned
2234 * from vidioc_streamoff handler in the driver
2236 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2239 dprintk(1, "file io in progress\n");
2242 return vb2_internal_streamoff(q, type);
2244 EXPORT_SYMBOL_GPL(vb2_streamoff);
2247 * __find_plane_by_offset() - find plane associated with the given offset off
2249 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2250 unsigned int *_buffer, unsigned int *_plane)
2252 struct vb2_buffer *vb;
2253 unsigned int buffer, plane;
2256 * Go over all buffers and their planes, comparing the given offset
2257 * with an offset assigned to each plane. If a match is found,
2258 * return its buffer and plane numbers.
2260 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2261 vb = q->bufs[buffer];
2263 for (plane = 0; plane < vb->num_planes; ++plane) {
2264 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2276 * vb2_expbuf() - Export a buffer as a file descriptor
2277 * @q: videobuf2 queue
2278 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2281 * The return values from this function are intended to be directly returned
2282 * from vidioc_expbuf handler in driver.
2284 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2286 struct vb2_buffer *vb = NULL;
2287 struct vb2_plane *vb_plane;
2289 struct dma_buf *dbuf;
2291 if (q->memory != V4L2_MEMORY_MMAP) {
2292 dprintk(1, "Queue is not currently set up for mmap\n");
2296 if (!q->mem_ops->get_dmabuf) {
2297 dprintk(1, "Queue does not support DMA buffer exporting\n");
2301 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2302 dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
2306 if (eb->type != q->type) {
2307 dprintk(1, "invalid buffer type\n");
2311 if (eb->index >= q->num_buffers) {
2312 dprintk(1, "buffer index out of range\n");
2316 vb = q->bufs[eb->index];
2318 if (eb->plane >= vb->num_planes) {
2319 dprintk(1, "buffer plane out of range\n");
2323 vb_plane = &vb->planes[eb->plane];
2325 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2326 if (IS_ERR_OR_NULL(dbuf)) {
2327 dprintk(1, "Failed to export buffer %d, plane %d\n",
2328 eb->index, eb->plane);
2332 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2334 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2335 eb->index, eb->plane, ret);
2340 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2341 eb->index, eb->plane, ret);
2346 EXPORT_SYMBOL_GPL(vb2_expbuf);
2349 * vb2_mmap() - map video buffers into application address space
2350 * @q: videobuf2 queue
2351 * @vma: vma passed to the mmap file operation handler in the driver
2353 * Should be called from mmap file operation handler of a driver.
2354 * This function maps one plane of one of the available video buffers to
2355 * userspace. To map whole video memory allocated on reqbufs, this function
2356 * has to be called once per each plane per each buffer previously allocated.
2358 * When the userspace application calls mmap, it passes to it an offset returned
2359 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2360 * a "cookie", which is then used to identify the plane to be mapped.
2361 * This function finds a plane with a matching offset and a mapping is performed
2362 * by the means of a provided memory operation.
2364 * The return values from this function are intended to be directly returned
2365 * from the mmap handler in driver.
2367 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2369 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2370 struct vb2_buffer *vb;
2371 unsigned int buffer, plane;
2373 unsigned long length;
2375 if (q->memory != V4L2_MEMORY_MMAP) {
2376 dprintk(1, "Queue is not currently set up for mmap\n");
2381 * Check memory area access mode.
2383 if (!(vma->vm_flags & VM_SHARED)) {
2384 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
2387 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2388 if (!(vma->vm_flags & VM_WRITE)) {
2389 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
2393 if (!(vma->vm_flags & VM_READ)) {
2394 dprintk(1, "Invalid vma flags, VM_READ needed\n");
2400 * Find the plane corresponding to the offset passed by userspace.
2402 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2406 vb = q->bufs[buffer];
2409 * MMAP requires page_aligned buffers.
2410 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2411 * so, we need to do the same here.
2413 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2414 if (length < (vma->vm_end - vma->vm_start)) {
2416 "MMAP invalid, as it would overflow buffer length\n");
2420 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2424 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
2427 EXPORT_SYMBOL_GPL(vb2_mmap);
2430 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2433 unsigned long pgoff,
2434 unsigned long flags)
2436 unsigned long off = pgoff << PAGE_SHIFT;
2437 struct vb2_buffer *vb;
2438 unsigned int buffer, plane;
2441 if (q->memory != V4L2_MEMORY_MMAP) {
2442 dprintk(1, "Queue is not currently set up for mmap\n");
2447 * Find the plane corresponding to the offset passed by userspace.
2449 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2453 vb = q->bufs[buffer];
2455 return (unsigned long)vb2_plane_vaddr(vb, plane);
2457 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2460 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2461 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2464 * vb2_poll() - implements poll userspace operation
2465 * @q: videobuf2 queue
2466 * @file: file argument passed to the poll file operation handler
2467 * @wait: wait argument passed to the poll file operation handler
2469 * This function implements poll file operation handler for a driver.
2470 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2471 * be informed that the file descriptor of a video device is available for
2473 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2474 * will be reported as available for writing.
2476 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2479 * The return values from this function are intended to be directly returned
2480 * from poll handler in driver.
2482 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2484 struct video_device *vfd = video_devdata(file);
2485 unsigned long req_events = poll_requested_events(wait);
2486 struct vb2_buffer *vb = NULL;
2487 unsigned int res = 0;
2488 unsigned long flags;
2490 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2491 struct v4l2_fh *fh = file->private_data;
2493 if (v4l2_event_pending(fh))
2495 else if (req_events & POLLPRI)
2496 poll_wait(file, &fh->wait, wait);
2499 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2501 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2505 * Start file I/O emulator only if streaming API has not been used yet.
2507 if (q->num_buffers == 0 && q->fileio == NULL) {
2508 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2509 (req_events & (POLLIN | POLLRDNORM))) {
2510 if (__vb2_init_fileio(q, 1))
2511 return res | POLLERR;
2513 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2514 (req_events & (POLLOUT | POLLWRNORM))) {
2515 if (__vb2_init_fileio(q, 0))
2516 return res | POLLERR;
2518 * Write to OUTPUT queue can be done immediately.
2520 return res | POLLOUT | POLLWRNORM;
2525 * There is nothing to wait for if no buffers have already been queued.
2527 if (list_empty(&q->queued_list))
2528 return res | POLLERR;
2530 if (list_empty(&q->done_list))
2531 poll_wait(file, &q->done_wq, wait);
2534 * Take first buffer available for dequeuing.
2536 spin_lock_irqsave(&q->done_lock, flags);
2537 if (!list_empty(&q->done_list))
2538 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2540 spin_unlock_irqrestore(&q->done_lock, flags);
2542 if (vb && (vb->state == VB2_BUF_STATE_DONE
2543 || vb->state == VB2_BUF_STATE_ERROR)) {
2544 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2545 res | POLLOUT | POLLWRNORM :
2546 res | POLLIN | POLLRDNORM;
2550 EXPORT_SYMBOL_GPL(vb2_poll);
2553 * vb2_queue_init() - initialize a videobuf2 queue
2554 * @q: videobuf2 queue; this structure should be allocated in driver
2556 * The vb2_queue structure should be allocated by the driver. The driver is
2557 * responsible of clearing it's content and setting initial values for some
2558 * required entries before calling this function.
2559 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2560 * to the struct vb2_queue description in include/media/videobuf2-core.h
2561 * for more information.
2563 int vb2_queue_init(struct vb2_queue *q)
2570 WARN_ON(!q->mem_ops) ||
2571 WARN_ON(!q->type) ||
2572 WARN_ON(!q->io_modes) ||
2573 WARN_ON(!q->ops->queue_setup) ||
2574 WARN_ON(!q->ops->buf_queue) ||
2575 WARN_ON(q->timestamp_flags &
2576 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2577 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2580 /* Warn that the driver should choose an appropriate timestamp type */
2581 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2582 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2584 INIT_LIST_HEAD(&q->queued_list);
2585 INIT_LIST_HEAD(&q->done_list);
2586 spin_lock_init(&q->done_lock);
2587 init_waitqueue_head(&q->done_wq);
2589 if (q->buf_struct_size == 0)
2590 q->buf_struct_size = sizeof(struct vb2_buffer);
2594 EXPORT_SYMBOL_GPL(vb2_queue_init);
2597 * vb2_queue_release() - stop streaming, release the queue and free memory
2598 * @q: videobuf2 queue
2600 * This function stops streaming and performs necessary clean ups, including
2601 * freeing video buffer memory. The driver is responsible for freeing
2602 * the vb2_queue structure itself.
2604 void vb2_queue_release(struct vb2_queue *q)
2606 __vb2_cleanup_fileio(q);
2607 __vb2_queue_cancel(q);
2608 __vb2_queue_free(q, q->num_buffers);
2610 EXPORT_SYMBOL_GPL(vb2_queue_release);
2613 * struct vb2_fileio_buf - buffer context used by file io emulator
2615 * vb2 provides a compatibility layer and emulator of file io (read and
2616 * write) calls on top of streaming API. This structure is used for
2617 * tracking context related to the buffers.
2619 struct vb2_fileio_buf {
2623 unsigned int queued:1;
2627 * struct vb2_fileio_data - queue context used by file io emulator
2629 * @cur_index: the index of the buffer currently being read from or
2630 * written to. If equal to q->num_buffers then a new buffer
2632 * @initial_index: in the read() case all buffers are queued up immediately
2633 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2634 * buffers. However, in the write() case no buffers are initially
2635 * queued, instead whenever a buffer is full it is queued up by
2636 * __vb2_perform_fileio(). Only once all available buffers have
2637 * been queued up will __vb2_perform_fileio() start to dequeue
2638 * buffers. This means that initially __vb2_perform_fileio()
2639 * needs to know what buffer index to use when it is queuing up
2640 * the buffers for the first time. That initial index is stored
2641 * in this field. Once it is equal to q->num_buffers all
2642 * available buffers have been queued and __vb2_perform_fileio()
2643 * should start the normal dequeue/queue cycle.
2645 * vb2 provides a compatibility layer and emulator of file io (read and
2646 * write) calls on top of streaming API. For proper operation it required
2647 * this structure to save the driver state between each call of the read
2648 * or write function.
2650 struct vb2_fileio_data {
2651 struct v4l2_requestbuffers req;
2652 struct v4l2_buffer b;
2653 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2654 unsigned int cur_index;
2655 unsigned int initial_index;
2656 unsigned int q_count;
2657 unsigned int dq_count;
2662 * __vb2_init_fileio() - initialize file io emulator
2663 * @q: videobuf2 queue
2664 * @read: mode selector (1 means read, 0 means write)
2666 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2668 struct vb2_fileio_data *fileio;
2670 unsigned int count = 0;
2675 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2676 (!read && !(q->io_modes & VB2_WRITE))))
2680 * Check if device supports mapping buffers to kernel virtual space.
2682 if (!q->mem_ops->vaddr)
2686 * Check if streaming api has not been already activated.
2688 if (q->streaming || q->num_buffers > 0)
2692 * Start with count 1, driver can increase it in queue_setup()
2696 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2697 (read) ? "read" : "write", count, q->io_flags);
2699 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2703 fileio->flags = q->io_flags;
2706 * Request buffers and use MMAP type to force driver
2707 * to allocate buffers by itself.
2709 fileio->req.count = count;
2710 fileio->req.memory = V4L2_MEMORY_MMAP;
2711 fileio->req.type = q->type;
2712 ret = vb2_reqbufs(q, &fileio->req);
2717 * Check if plane_count is correct
2718 * (multiplane buffers are not supported).
2720 if (q->bufs[0]->num_planes != 1) {
2726 * Get kernel address of each buffer.
2728 for (i = 0; i < q->num_buffers; i++) {
2729 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2730 if (fileio->bufs[i].vaddr == NULL) {
2734 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2738 * Read mode requires pre queuing of all buffers.
2742 * Queue all buffers.
2744 for (i = 0; i < q->num_buffers; i++) {
2745 struct v4l2_buffer *b = &fileio->b;
2746 memset(b, 0, sizeof(*b));
2748 b->memory = q->memory;
2750 ret = vb2_qbuf(q, b);
2753 fileio->bufs[i].queued = 1;
2756 * All buffers have been queued, so mark that by setting
2757 * initial_index to q->num_buffers
2759 fileio->initial_index = q->num_buffers;
2760 fileio->cur_index = q->num_buffers;
2766 ret = vb2_streamon(q, q->type);
2775 fileio->req.count = 0;
2776 vb2_reqbufs(q, &fileio->req);
2784 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2785 * @q: videobuf2 queue
2787 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2789 struct vb2_fileio_data *fileio = q->fileio;
2792 vb2_internal_streamoff(q, q->type);
2794 fileio->req.count = 0;
2795 vb2_reqbufs(q, &fileio->req);
2797 dprintk(3, "file io emulator closed\n");
2803 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2804 * @q: videobuf2 queue
2805 * @data: pointed to target userspace buffer
2806 * @count: number of bytes to read or write
2807 * @ppos: file handle position tracking pointer
2808 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2809 * @read: access mode selector (1 means read, 0 means write)
2811 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2812 loff_t *ppos, int nonblock, int read)
2814 struct vb2_fileio_data *fileio;
2815 struct vb2_fileio_buf *buf;
2817 * When using write() to write data to an output video node the vb2 core
2818 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2819 * else is able to provide this information with the write() operation.
2821 bool set_timestamp = !read &&
2822 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2823 V4L2_BUF_FLAG_TIMESTAMP_COPY;
2826 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2827 read ? "read" : "write", (long)*ppos, count,
2828 nonblock ? "non" : "");
2834 * Initialize emulator on first call.
2837 ret = __vb2_init_fileio(q, read);
2838 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2845 * Check if we need to dequeue the buffer.
2847 index = fileio->cur_index;
2848 if (index >= q->num_buffers) {
2850 * Call vb2_dqbuf to get buffer back.
2852 memset(&fileio->b, 0, sizeof(fileio->b));
2853 fileio->b.type = q->type;
2854 fileio->b.memory = q->memory;
2855 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
2856 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2859 fileio->dq_count += 1;
2861 fileio->cur_index = index = fileio->b.index;
2862 buf = &fileio->bufs[index];
2865 * Get number of bytes filled by the driver
2869 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2870 : vb2_plane_size(q->bufs[index], 0);
2872 buf = &fileio->bufs[index];
2876 * Limit count on last few bytes of the buffer.
2878 if (buf->pos + count > buf->size) {
2879 count = buf->size - buf->pos;
2880 dprintk(5, "reducing read count: %zd\n", count);
2884 * Transfer data to userspace.
2886 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2887 count, index, buf->pos);
2889 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2891 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2893 dprintk(3, "error copying data\n");
2904 * Queue next buffer if required.
2906 if (buf->pos == buf->size ||
2907 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
2909 * Check if this is the last buffer to read.
2911 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2912 fileio->dq_count == 1) {
2913 dprintk(3, "read limit reached\n");
2914 return __vb2_cleanup_fileio(q);
2918 * Call vb2_qbuf and give buffer to the driver.
2920 memset(&fileio->b, 0, sizeof(fileio->b));
2921 fileio->b.type = q->type;
2922 fileio->b.memory = q->memory;
2923 fileio->b.index = index;
2924 fileio->b.bytesused = buf->pos;
2926 v4l2_get_timestamp(&fileio->b.timestamp);
2927 ret = vb2_internal_qbuf(q, &fileio->b);
2928 dprintk(5, "vb2_dbuf result: %d\n", ret);
2933 * Buffer has been queued, update the status
2937 buf->size = vb2_plane_size(q->bufs[index], 0);
2938 fileio->q_count += 1;
2940 * If we are queuing up buffers for the first time, then
2941 * increase initial_index by one.
2943 if (fileio->initial_index < q->num_buffers)
2944 fileio->initial_index++;
2946 * The next buffer to use is either a buffer that's going to be
2947 * queued for the first time (initial_index < q->num_buffers)
2948 * or it is equal to q->num_buffers, meaning that the next
2949 * time we need to dequeue a buffer since we've now queued up
2950 * all the 'first time' buffers.
2952 fileio->cur_index = fileio->initial_index;
2956 * Return proper number of bytes processed.
2963 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2964 loff_t *ppos, int nonblocking)
2966 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2968 EXPORT_SYMBOL_GPL(vb2_read);
2970 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2971 loff_t *ppos, int nonblocking)
2973 return __vb2_perform_fileio(q, (char __user *) data, count,
2974 ppos, nonblocking, 0);
2976 EXPORT_SYMBOL_GPL(vb2_write);
2980 * The following functions are not part of the vb2 core API, but are helper
2981 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2982 * and struct vb2_ops.
2983 * They contain boilerplate code that most if not all drivers have to do
2984 * and so they simplify the driver code.
2987 /* The queue is busy if there is a owner and you are not that owner. */
2988 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
2990 return vdev->queue->owner && vdev->queue->owner != file->private_data;
2993 /* vb2 ioctl helpers */
2995 int vb2_ioctl_reqbufs(struct file *file, void *priv,
2996 struct v4l2_requestbuffers *p)
2998 struct video_device *vdev = video_devdata(file);
2999 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3003 if (vb2_queue_is_busy(vdev, file))
3005 res = __reqbufs(vdev->queue, p);
3006 /* If count == 0, then the owner has released all buffers and he
3007 is no longer owner of the queue. Otherwise we have a new owner. */
3009 vdev->queue->owner = p->count ? file->private_data : NULL;
3012 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3014 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3015 struct v4l2_create_buffers *p)
3017 struct video_device *vdev = video_devdata(file);
3018 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3020 p->index = vdev->queue->num_buffers;
3021 /* If count == 0, then just check if memory and type are valid.
3022 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3024 return res != -EBUSY ? res : 0;
3027 if (vb2_queue_is_busy(vdev, file))
3029 res = __create_bufs(vdev->queue, p);
3031 vdev->queue->owner = file->private_data;
3034 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3036 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3037 struct v4l2_buffer *p)
3039 struct video_device *vdev = video_devdata(file);
3041 if (vb2_queue_is_busy(vdev, file))
3043 return vb2_prepare_buf(vdev->queue, p);
3045 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3047 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3049 struct video_device *vdev = video_devdata(file);
3051 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3052 return vb2_querybuf(vdev->queue, p);
3054 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3056 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3058 struct video_device *vdev = video_devdata(file);
3060 if (vb2_queue_is_busy(vdev, file))
3062 return vb2_qbuf(vdev->queue, p);
3064 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3066 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3068 struct video_device *vdev = video_devdata(file);
3070 if (vb2_queue_is_busy(vdev, file))
3072 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3074 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3076 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3078 struct video_device *vdev = video_devdata(file);
3080 if (vb2_queue_is_busy(vdev, file))
3082 return vb2_streamon(vdev->queue, i);
3084 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3086 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3088 struct video_device *vdev = video_devdata(file);
3090 if (vb2_queue_is_busy(vdev, file))
3092 return vb2_streamoff(vdev->queue, i);
3094 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3096 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3098 struct video_device *vdev = video_devdata(file);
3100 if (vb2_queue_is_busy(vdev, file))
3102 return vb2_expbuf(vdev->queue, p);
3104 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3106 /* v4l2_file_operations helpers */
3108 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3110 struct video_device *vdev = video_devdata(file);
3111 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3114 if (lock && mutex_lock_interruptible(lock))
3115 return -ERESTARTSYS;
3116 err = vb2_mmap(vdev->queue, vma);
3121 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3123 int _vb2_fop_release(struct file *file, struct mutex *lock)
3125 struct video_device *vdev = video_devdata(file);
3127 if (file->private_data == vdev->queue->owner) {
3130 vb2_queue_release(vdev->queue);
3131 vdev->queue->owner = NULL;
3135 return v4l2_fh_release(file);
3137 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3139 int vb2_fop_release(struct file *file)
3141 struct video_device *vdev = video_devdata(file);
3142 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3144 return _vb2_fop_release(file, lock);
3146 EXPORT_SYMBOL_GPL(vb2_fop_release);
3148 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3149 size_t count, loff_t *ppos)
3151 struct video_device *vdev = video_devdata(file);
3152 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3155 if (lock && mutex_lock_interruptible(lock))
3156 return -ERESTARTSYS;
3157 if (vb2_queue_is_busy(vdev, file))
3159 err = vb2_write(vdev->queue, buf, count, ppos,
3160 file->f_flags & O_NONBLOCK);
3161 if (vdev->queue->fileio)
3162 vdev->queue->owner = file->private_data;
3168 EXPORT_SYMBOL_GPL(vb2_fop_write);
3170 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3171 size_t count, loff_t *ppos)
3173 struct video_device *vdev = video_devdata(file);
3174 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3177 if (lock && mutex_lock_interruptible(lock))
3178 return -ERESTARTSYS;
3179 if (vb2_queue_is_busy(vdev, file))
3181 err = vb2_read(vdev->queue, buf, count, ppos,
3182 file->f_flags & O_NONBLOCK);
3183 if (vdev->queue->fileio)
3184 vdev->queue->owner = file->private_data;
3190 EXPORT_SYMBOL_GPL(vb2_fop_read);
3192 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3194 struct video_device *vdev = video_devdata(file);
3195 struct vb2_queue *q = vdev->queue;
3196 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3197 unsigned long req_events = poll_requested_events(wait);
3200 bool must_lock = false;
3202 /* Try to be smart: only lock if polling might start fileio,
3203 otherwise locking will only introduce unwanted delays. */
3204 if (q->num_buffers == 0 && q->fileio == NULL) {
3205 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
3206 (req_events & (POLLIN | POLLRDNORM)))
3208 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
3209 (req_events & (POLLOUT | POLLWRNORM)))
3213 /* If locking is needed, but this helper doesn't know how, then you
3214 shouldn't be using this helper but you should write your own. */
3215 WARN_ON(must_lock && !lock);
3217 if (must_lock && lock && mutex_lock_interruptible(lock))
3222 res = vb2_poll(vdev->queue, file, wait);
3224 /* If fileio was started, then we have a new queue owner. */
3225 if (must_lock && !fileio && q->fileio)
3226 q->owner = file->private_data;
3227 if (must_lock && lock)
3231 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3234 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3235 unsigned long len, unsigned long pgoff, unsigned long flags)
3237 struct video_device *vdev = video_devdata(file);
3238 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3241 if (lock && mutex_lock_interruptible(lock))
3242 return -ERESTARTSYS;
3243 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3248 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3251 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3253 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3255 mutex_unlock(vq->lock);
3257 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3259 void vb2_ops_wait_finish(struct vb2_queue *vq)
3261 mutex_lock(vq->lock);
3263 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3265 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3266 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3267 MODULE_LICENSE("GPL");