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 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
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.
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
34 module_param(debug, int, 0644);
36 #define dprintk(level, fmt, arg...) \
39 pr_info("vb2: %s: " fmt, __func__, ## arg); \
42 #ifdef CONFIG_VIDEO_ADV_DEBUG
45 * If advanced debugging is on, then count how often each op is called
46 * successfully, which can either be per-buffer or per-queue.
48 * This makes it easy to check that the 'init' and 'cleanup'
49 * (and variations thereof) stay balanced.
52 #define log_memop(vb, op) \
53 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
54 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
55 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
57 #define call_memop(vb, op, args...) \
59 struct vb2_queue *_q = (vb)->vb2_queue; \
63 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
65 (vb)->cnt_mem_ ## op++; \
69 #define call_ptr_memop(vb, op, args...) \
71 struct vb2_queue *_q = (vb)->vb2_queue; \
75 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
76 if (!IS_ERR_OR_NULL(ptr)) \
77 (vb)->cnt_mem_ ## op++; \
81 #define call_void_memop(vb, op, args...) \
83 struct vb2_queue *_q = (vb)->vb2_queue; \
86 if (_q->mem_ops->op) \
87 _q->mem_ops->op(args); \
88 (vb)->cnt_mem_ ## op++; \
91 #define log_qop(q, op) \
92 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
93 (q)->ops->op ? "" : " (nop)")
95 #define call_qop(q, op, args...) \
100 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
106 #define call_void_qop(q, op, args...) \
110 (q)->ops->op(args); \
114 #define log_vb_qop(vb, op, args...) \
115 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
116 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
117 (vb)->vb2_queue->ops->op ? "" : " (nop)")
119 #define call_vb_qop(vb, op, args...) \
123 log_vb_qop(vb, op); \
124 err = (vb)->vb2_queue->ops->op ? \
125 (vb)->vb2_queue->ops->op(args) : 0; \
127 (vb)->cnt_ ## op++; \
131 #define call_void_vb_qop(vb, op, args...) \
133 log_vb_qop(vb, op); \
134 if ((vb)->vb2_queue->ops->op) \
135 (vb)->vb2_queue->ops->op(args); \
136 (vb)->cnt_ ## op++; \
141 #define call_memop(vb, op, args...) \
142 ((vb)->vb2_queue->mem_ops->op ? \
143 (vb)->vb2_queue->mem_ops->op(args) : 0)
145 #define call_ptr_memop(vb, op, args...) \
146 ((vb)->vb2_queue->mem_ops->op ? \
147 (vb)->vb2_queue->mem_ops->op(args) : NULL)
149 #define call_void_memop(vb, op, args...) \
151 if ((vb)->vb2_queue->mem_ops->op) \
152 (vb)->vb2_queue->mem_ops->op(args); \
155 #define call_qop(q, op, args...) \
156 ((q)->ops->op ? (q)->ops->op(args) : 0)
158 #define call_void_qop(q, op, args...) \
161 (q)->ops->op(args); \
164 #define call_vb_qop(vb, op, args...) \
165 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
167 #define call_void_vb_qop(vb, op, args...) \
169 if ((vb)->vb2_queue->ops->op) \
170 (vb)->vb2_queue->ops->op(args); \
175 /* Flags that are set by the vb2 core */
176 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
177 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
178 V4L2_BUF_FLAG_PREPARED | \
179 V4L2_BUF_FLAG_TIMESTAMP_MASK)
180 /* Output buffer flags that should be passed on to the driver */
181 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
182 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
184 static void __vb2_queue_cancel(struct vb2_queue *q);
185 static void __enqueue_in_driver(struct vb2_buffer *vb);
188 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
190 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
192 struct vb2_queue *q = vb->vb2_queue;
193 enum dma_data_direction dma_dir =
194 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
199 * Allocate memory for all planes in this buffer
200 * NOTE: mmapped areas should be page aligned
202 for (plane = 0; plane < vb->num_planes; ++plane) {
203 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
205 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
206 size, dma_dir, q->gfp_flags);
207 if (IS_ERR_OR_NULL(mem_priv))
210 /* Associate allocator private data with this plane */
211 vb->planes[plane].mem_priv = mem_priv;
212 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
217 /* Free already allocated memory if one of the allocations failed */
218 for (; plane > 0; --plane) {
219 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
220 vb->planes[plane - 1].mem_priv = NULL;
227 * __vb2_buf_mem_free() - free memory of the given buffer
229 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
233 for (plane = 0; plane < vb->num_planes; ++plane) {
234 call_void_memop(vb, put, vb->planes[plane].mem_priv);
235 vb->planes[plane].mem_priv = NULL;
236 dprintk(3, "freed plane %d of buffer %d\n", plane,
242 * __vb2_buf_userptr_put() - release userspace memory associated with
245 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
249 for (plane = 0; plane < vb->num_planes; ++plane) {
250 if (vb->planes[plane].mem_priv)
251 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
252 vb->planes[plane].mem_priv = NULL;
257 * __vb2_plane_dmabuf_put() - release memory associated with
258 * a DMABUF shared plane
260 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
266 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
268 call_void_memop(vb, detach_dmabuf, p->mem_priv);
269 dma_buf_put(p->dbuf);
270 memset(p, 0, sizeof(*p));
274 * __vb2_buf_dmabuf_put() - release memory associated with
275 * a DMABUF shared buffer
277 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
281 for (plane = 0; plane < vb->num_planes; ++plane)
282 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
286 * __setup_lengths() - setup initial lengths for every plane in
287 * every buffer on the queue
289 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
291 unsigned int buffer, plane;
292 struct vb2_buffer *vb;
294 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
295 vb = q->bufs[buffer];
299 for (plane = 0; plane < vb->num_planes; ++plane)
300 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
305 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
306 * every buffer on the queue
308 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
310 unsigned int buffer, plane;
311 struct vb2_buffer *vb;
314 if (q->num_buffers) {
315 struct v4l2_plane *p;
316 vb = q->bufs[q->num_buffers - 1];
317 p = &vb->v4l2_planes[vb->num_planes - 1];
318 off = PAGE_ALIGN(p->m.mem_offset + p->length);
323 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
324 vb = q->bufs[buffer];
328 for (plane = 0; plane < vb->num_planes; ++plane) {
329 vb->v4l2_planes[plane].m.mem_offset = off;
331 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
334 off += vb->v4l2_planes[plane].length;
335 off = PAGE_ALIGN(off);
341 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
342 * video buffer memory for all buffers/planes on the queue and initializes the
345 * Returns the number of buffers successfully allocated.
347 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
348 unsigned int num_buffers, unsigned int num_planes)
351 struct vb2_buffer *vb;
354 for (buffer = 0; buffer < num_buffers; ++buffer) {
355 /* Allocate videobuf buffer structures */
356 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
358 dprintk(1, "memory alloc for buffer struct failed\n");
362 /* Length stores number of planes for multiplanar buffers */
363 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
364 vb->v4l2_buf.length = num_planes;
366 vb->state = VB2_BUF_STATE_DEQUEUED;
368 vb->num_planes = num_planes;
369 vb->v4l2_buf.index = q->num_buffers + buffer;
370 vb->v4l2_buf.type = q->type;
371 vb->v4l2_buf.memory = memory;
373 /* Allocate video buffer memory for the MMAP type */
374 if (memory == V4L2_MEMORY_MMAP) {
375 ret = __vb2_buf_mem_alloc(vb);
377 dprintk(1, "failed allocating memory for "
378 "buffer %d\n", buffer);
383 * Call the driver-provided buffer initialization
384 * callback, if given. An error in initialization
385 * results in queue setup failure.
387 ret = call_vb_qop(vb, buf_init, vb);
389 dprintk(1, "buffer %d %p initialization"
390 " failed\n", buffer, vb);
391 __vb2_buf_mem_free(vb);
397 q->bufs[q->num_buffers + buffer] = vb;
400 __setup_lengths(q, buffer);
401 if (memory == V4L2_MEMORY_MMAP)
402 __setup_offsets(q, buffer);
404 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
411 * __vb2_free_mem() - release all video buffer memory for a given queue
413 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
416 struct vb2_buffer *vb;
418 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
420 vb = q->bufs[buffer];
424 /* Free MMAP buffers or release USERPTR buffers */
425 if (q->memory == V4L2_MEMORY_MMAP)
426 __vb2_buf_mem_free(vb);
427 else if (q->memory == V4L2_MEMORY_DMABUF)
428 __vb2_buf_dmabuf_put(vb);
430 __vb2_buf_userptr_put(vb);
435 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
436 * related information, if no buffers are left return the queue to an
437 * uninitialized state. Might be called even if the queue has already been freed.
439 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
444 * Sanity check: when preparing a buffer the queue lock is released for
445 * a short while (see __buf_prepare for the details), which would allow
446 * a race with a reqbufs which can call this function. Removing the
447 * buffers from underneath __buf_prepare is obviously a bad idea, so we
448 * check if any of the buffers is in the state PREPARING, and if so we
449 * just return -EAGAIN.
451 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
453 if (q->bufs[buffer] == NULL)
455 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
456 dprintk(1, "preparing buffers, cannot free\n");
461 /* Call driver-provided cleanup function for each buffer, if provided */
462 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
464 struct vb2_buffer *vb = q->bufs[buffer];
466 if (vb && vb->planes[0].mem_priv)
467 call_void_vb_qop(vb, buf_cleanup, vb);
470 /* Release video buffer memory */
471 __vb2_free_mem(q, buffers);
473 #ifdef CONFIG_VIDEO_ADV_DEBUG
475 * Check that all the calls were balances during the life-time of this
476 * queue. If not (or if the debug level is 1 or up), then dump the
477 * counters to the kernel log.
479 if (q->num_buffers) {
480 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
481 q->cnt_wait_prepare != q->cnt_wait_finish;
483 if (unbalanced || debug) {
484 pr_info("vb2: counters for queue %p:%s\n", q,
485 unbalanced ? " UNBALANCED!" : "");
486 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
487 q->cnt_queue_setup, q->cnt_start_streaming,
488 q->cnt_stop_streaming);
489 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
490 q->cnt_wait_prepare, q->cnt_wait_finish);
492 q->cnt_queue_setup = 0;
493 q->cnt_wait_prepare = 0;
494 q->cnt_wait_finish = 0;
495 q->cnt_start_streaming = 0;
496 q->cnt_stop_streaming = 0;
498 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
499 struct vb2_buffer *vb = q->bufs[buffer];
500 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
501 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
502 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
503 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
504 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
505 vb->cnt_buf_queue != vb->cnt_buf_done ||
506 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
507 vb->cnt_buf_init != vb->cnt_buf_cleanup;
509 if (unbalanced || debug) {
510 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
511 q, buffer, unbalanced ? " UNBALANCED!" : "");
512 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
513 vb->cnt_buf_init, vb->cnt_buf_cleanup,
514 vb->cnt_buf_prepare, vb->cnt_buf_finish);
515 pr_info("vb2: buf_queue: %u buf_done: %u\n",
516 vb->cnt_buf_queue, vb->cnt_buf_done);
517 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
518 vb->cnt_mem_alloc, vb->cnt_mem_put,
519 vb->cnt_mem_prepare, vb->cnt_mem_finish,
521 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
522 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
523 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
524 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
525 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
526 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
527 vb->cnt_mem_get_dmabuf,
528 vb->cnt_mem_num_users,
535 /* Free videobuf buffers */
536 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
538 kfree(q->bufs[buffer]);
539 q->bufs[buffer] = NULL;
542 q->num_buffers -= buffers;
543 if (!q->num_buffers) {
545 INIT_LIST_HEAD(&q->queued_list);
551 * __verify_planes_array() - verify that the planes array passed in struct
552 * v4l2_buffer from userspace can be safely used
554 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
556 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
559 /* Is memory for copying plane information present? */
560 if (NULL == b->m.planes) {
561 dprintk(1, "multi-planar buffer passed but "
562 "planes array not provided\n");
566 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
567 dprintk(1, "incorrect planes array length, "
568 "expected %d, got %d\n", vb->num_planes, b->length);
576 * __verify_length() - Verify that the bytesused value for each plane fits in
577 * the plane length and that the data offset doesn't exceed the bytesused value.
579 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
582 unsigned int bytesused;
585 if (!V4L2_TYPE_IS_OUTPUT(b->type))
588 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
589 for (plane = 0; plane < vb->num_planes; ++plane) {
590 length = (b->memory == V4L2_MEMORY_USERPTR ||
591 b->memory == V4L2_MEMORY_DMABUF)
592 ? b->m.planes[plane].length
593 : vb->v4l2_planes[plane].length;
594 bytesused = b->m.planes[plane].bytesused
595 ? b->m.planes[plane].bytesused : length;
597 if (b->m.planes[plane].bytesused > length)
600 if (b->m.planes[plane].data_offset > 0 &&
601 b->m.planes[plane].data_offset >= bytesused)
605 length = (b->memory == V4L2_MEMORY_USERPTR)
606 ? b->length : vb->v4l2_planes[0].length;
607 bytesused = b->bytesused ? b->bytesused : length;
609 if (b->bytesused > length)
617 * __buffer_in_use() - return true if the buffer is in use and
618 * the queue cannot be freed (by the means of REQBUFS(0)) call
620 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
623 for (plane = 0; plane < vb->num_planes; ++plane) {
624 void *mem_priv = vb->planes[plane].mem_priv;
626 * If num_users() has not been provided, call_memop
627 * will return 0, apparently nobody cares about this
628 * case anyway. If num_users() returns more than 1,
629 * we are not the only user of the plane's memory.
631 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
638 * __buffers_in_use() - return true if any buffers on the queue are in use and
639 * the queue cannot be freed (by the means of REQBUFS(0)) call
641 static bool __buffers_in_use(struct vb2_queue *q)
644 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
645 if (__buffer_in_use(q, q->bufs[buffer]))
652 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
653 * returned to userspace
655 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
657 struct vb2_queue *q = vb->vb2_queue;
659 /* Copy back data such as timestamp, flags, etc. */
660 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
661 b->reserved2 = vb->v4l2_buf.reserved2;
662 b->reserved = vb->v4l2_buf.reserved;
664 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
666 * Fill in plane-related data if userspace provided an array
667 * for it. The caller has already verified memory and size.
669 b->length = vb->num_planes;
670 memcpy(b->m.planes, vb->v4l2_planes,
671 b->length * sizeof(struct v4l2_plane));
674 * We use length and offset in v4l2_planes array even for
675 * single-planar buffers, but userspace does not.
677 b->length = vb->v4l2_planes[0].length;
678 b->bytesused = vb->v4l2_planes[0].bytesused;
679 if (q->memory == V4L2_MEMORY_MMAP)
680 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
681 else if (q->memory == V4L2_MEMORY_USERPTR)
682 b->m.userptr = vb->v4l2_planes[0].m.userptr;
683 else if (q->memory == V4L2_MEMORY_DMABUF)
684 b->m.fd = vb->v4l2_planes[0].m.fd;
688 * Clear any buffer state related flags.
690 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
691 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
692 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
693 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
695 * For non-COPY timestamps, drop timestamp source bits
696 * and obtain the timestamp source from the queue.
698 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
699 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
703 case VB2_BUF_STATE_QUEUED:
704 case VB2_BUF_STATE_ACTIVE:
705 b->flags |= V4L2_BUF_FLAG_QUEUED;
707 case VB2_BUF_STATE_ERROR:
708 b->flags |= V4L2_BUF_FLAG_ERROR;
710 case VB2_BUF_STATE_DONE:
711 b->flags |= V4L2_BUF_FLAG_DONE;
713 case VB2_BUF_STATE_PREPARED:
714 b->flags |= V4L2_BUF_FLAG_PREPARED;
716 case VB2_BUF_STATE_PREPARING:
717 case VB2_BUF_STATE_DEQUEUED:
722 if (__buffer_in_use(q, vb))
723 b->flags |= V4L2_BUF_FLAG_MAPPED;
727 * vb2_querybuf() - query video buffer information
729 * @b: buffer struct passed from userspace to vidioc_querybuf handler
732 * Should be called from vidioc_querybuf ioctl handler in driver.
733 * This function will verify the passed v4l2_buffer structure and fill the
734 * relevant information for the userspace.
736 * The return values from this function are intended to be directly returned
737 * from vidioc_querybuf handler in driver.
739 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
741 struct vb2_buffer *vb;
744 if (b->type != q->type) {
745 dprintk(1, "wrong buffer type\n");
749 if (b->index >= q->num_buffers) {
750 dprintk(1, "buffer index out of range\n");
753 vb = q->bufs[b->index];
754 ret = __verify_planes_array(vb, b);
756 __fill_v4l2_buffer(vb, b);
759 EXPORT_SYMBOL(vb2_querybuf);
762 * __verify_userptr_ops() - verify that all memory operations required for
763 * USERPTR queue type have been provided
765 static int __verify_userptr_ops(struct vb2_queue *q)
767 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
768 !q->mem_ops->put_userptr)
775 * __verify_mmap_ops() - verify that all memory operations required for
776 * MMAP queue type have been provided
778 static int __verify_mmap_ops(struct vb2_queue *q)
780 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
781 !q->mem_ops->put || !q->mem_ops->mmap)
788 * __verify_dmabuf_ops() - verify that all memory operations required for
789 * DMABUF queue type have been provided
791 static int __verify_dmabuf_ops(struct vb2_queue *q)
793 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
794 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
795 !q->mem_ops->unmap_dmabuf)
802 * __verify_memory_type() - Check whether the memory type and buffer type
803 * passed to a buffer operation are compatible with the queue.
805 static int __verify_memory_type(struct vb2_queue *q,
806 enum v4l2_memory memory, enum v4l2_buf_type type)
808 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
809 memory != V4L2_MEMORY_DMABUF) {
810 dprintk(1, "unsupported memory type\n");
814 if (type != q->type) {
815 dprintk(1, "requested type is incorrect\n");
820 * Make sure all the required memory ops for given memory type
823 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
824 dprintk(1, "MMAP for current setup unsupported\n");
828 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
829 dprintk(1, "USERPTR for current setup unsupported\n");
833 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
834 dprintk(1, "DMABUF for current setup unsupported\n");
839 * Place the busy tests at the end: -EBUSY can be ignored when
840 * create_bufs is called with count == 0, but count == 0 should still
841 * do the memory and type validation.
843 if (vb2_fileio_is_active(q)) {
844 dprintk(1, "file io in progress\n");
851 * __reqbufs() - Initiate streaming
852 * @q: videobuf2 queue
853 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
855 * Should be called from vidioc_reqbufs ioctl handler of a driver.
857 * 1) verifies streaming parameters passed from the userspace,
858 * 2) sets up the queue,
859 * 3) negotiates number of buffers and planes per buffer with the driver
860 * to be used during streaming,
861 * 4) allocates internal buffer structures (struct vb2_buffer), according to
862 * the agreed parameters,
863 * 5) for MMAP memory type, allocates actual video memory, using the
864 * memory handling/allocation routines provided during queue initialization
866 * If req->count is 0, all the memory will be freed instead.
867 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
868 * and the queue is not busy, memory will be reallocated.
870 * The return values from this function are intended to be directly returned
871 * from vidioc_reqbufs handler in driver.
873 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
875 unsigned int num_buffers, allocated_buffers, num_planes = 0;
879 dprintk(1, "streaming active\n");
883 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
885 * We already have buffers allocated, so first check if they
886 * are not in use and can be freed.
888 mutex_lock(&q->mmap_lock);
889 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
890 mutex_unlock(&q->mmap_lock);
891 dprintk(1, "memory in use, cannot free\n");
896 * Call queue_cancel to clean up any buffers in the PREPARED or
897 * QUEUED state which is possible if buffers were prepared or
898 * queued without ever calling STREAMON.
900 __vb2_queue_cancel(q);
901 ret = __vb2_queue_free(q, q->num_buffers);
902 mutex_unlock(&q->mmap_lock);
907 * In case of REQBUFS(0) return immediately without calling
908 * driver's queue_setup() callback and allocating resources.
915 * Make sure the requested values and current defaults are sane.
917 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
918 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
919 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
920 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
921 q->memory = req->memory;
924 * Ask the driver how many buffers and planes per buffer it requires.
925 * Driver also sets the size and allocator context for each plane.
927 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
928 q->plane_sizes, q->alloc_ctx);
932 /* Finally, allocate buffers and video memory */
933 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
934 if (allocated_buffers == 0) {
935 dprintk(1, "memory allocation failed\n");
940 * There is no point in continuing if we can't allocate the minimum
941 * number of buffers needed by this vb2_queue.
943 if (allocated_buffers < q->min_buffers_needed)
947 * Check if driver can handle the allocated number of buffers.
949 if (!ret && allocated_buffers < num_buffers) {
950 num_buffers = allocated_buffers;
952 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
953 &num_planes, q->plane_sizes, q->alloc_ctx);
955 if (!ret && allocated_buffers < num_buffers)
959 * Either the driver has accepted a smaller number of buffers,
960 * or .queue_setup() returned an error
964 mutex_lock(&q->mmap_lock);
965 q->num_buffers = allocated_buffers;
969 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
970 * from q->num_buffers.
972 __vb2_queue_free(q, allocated_buffers);
973 mutex_unlock(&q->mmap_lock);
976 mutex_unlock(&q->mmap_lock);
979 * Return the number of successfully allocated buffers
982 req->count = allocated_buffers;
983 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
989 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
991 * @q: videobuf2 queue
992 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
994 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
996 int ret = __verify_memory_type(q, req->memory, req->type);
998 return ret ? ret : __reqbufs(q, req);
1000 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1003 * __create_bufs() - Allocate buffers and any required auxiliary structs
1004 * @q: videobuf2 queue
1005 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1008 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1010 * 1) verifies parameter sanity
1011 * 2) calls the .queue_setup() queue operation
1012 * 3) performs any necessary memory allocations
1014 * The return values from this function are intended to be directly returned
1015 * from vidioc_create_bufs handler in driver.
1017 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1019 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1022 if (q->num_buffers == VIDEO_MAX_FRAME) {
1023 dprintk(1, "maximum number of buffers already allocated\n");
1027 if (!q->num_buffers) {
1028 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1029 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1030 q->memory = create->memory;
1031 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1034 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1037 * Ask the driver, whether the requested number of buffers, planes per
1038 * buffer and their sizes are acceptable
1040 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1041 &num_planes, q->plane_sizes, q->alloc_ctx);
1045 /* Finally, allocate buffers and video memory */
1046 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1048 if (allocated_buffers == 0) {
1049 dprintk(1, "memory allocation failed\n");
1054 * Check if driver can handle the so far allocated number of buffers.
1056 if (allocated_buffers < num_buffers) {
1057 num_buffers = allocated_buffers;
1060 * q->num_buffers contains the total number of buffers, that the
1061 * queue driver has set up
1063 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1064 &num_planes, q->plane_sizes, q->alloc_ctx);
1066 if (!ret && allocated_buffers < num_buffers)
1070 * Either the driver has accepted a smaller number of buffers,
1071 * or .queue_setup() returned an error
1075 mutex_lock(&q->mmap_lock);
1076 q->num_buffers += allocated_buffers;
1080 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1081 * from q->num_buffers.
1083 __vb2_queue_free(q, allocated_buffers);
1084 mutex_unlock(&q->mmap_lock);
1087 mutex_unlock(&q->mmap_lock);
1090 * Return the number of successfully allocated buffers
1093 create->count = allocated_buffers;
1099 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1100 * memory and type values.
1101 * @q: videobuf2 queue
1102 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1105 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1107 int ret = __verify_memory_type(q, create->memory, create->format.type);
1109 create->index = q->num_buffers;
1110 if (create->count == 0)
1111 return ret != -EBUSY ? ret : 0;
1112 return ret ? ret : __create_bufs(q, create);
1114 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1117 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1118 * @vb: vb2_buffer to which the plane in question belongs to
1119 * @plane_no: plane number for which the address is to be returned
1121 * This function returns a kernel virtual address of a given plane if
1122 * such a mapping exist, NULL otherwise.
1124 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1126 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1129 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1132 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1135 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1136 * @vb: vb2_buffer to which the plane in question belongs to
1137 * @plane_no: plane number for which the cookie is to be returned
1139 * This function returns an allocator specific cookie for a given plane if
1140 * available, NULL otherwise. The allocator should provide some simple static
1141 * inline function, which would convert this cookie to the allocator specific
1142 * type that can be used directly by the driver to access the buffer. This can
1143 * be for example physical address, pointer to scatter list or IOMMU mapping.
1145 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1147 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1150 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1152 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1155 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1156 * @vb: vb2_buffer returned from the driver
1157 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1158 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1159 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1160 * If start_streaming fails then it should return buffers with state
1161 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1163 * This function should be called by the driver after a hardware operation on
1164 * a buffer is finished and the buffer may be returned to userspace. The driver
1165 * cannot use this buffer anymore until it is queued back to it by videobuf
1166 * by the means of buf_queue callback. Only buffers previously queued to the
1167 * driver by buf_queue can be passed to this function.
1169 * While streaming a buffer can only be returned in state DONE or ERROR.
1170 * The start_streaming op can also return them in case the DMA engine cannot
1171 * be started for some reason. In that case the buffers should be returned with
1174 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1176 struct vb2_queue *q = vb->vb2_queue;
1177 unsigned long flags;
1180 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1183 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1184 state != VB2_BUF_STATE_ERROR &&
1185 state != VB2_BUF_STATE_QUEUED))
1186 state = VB2_BUF_STATE_ERROR;
1188 #ifdef CONFIG_VIDEO_ADV_DEBUG
1190 * Although this is not a callback, it still does have to balance
1191 * with the buf_queue op. So update this counter manually.
1195 dprintk(4, "done processing on buffer %d, state: %d\n",
1196 vb->v4l2_buf.index, state);
1199 for (plane = 0; plane < vb->num_planes; ++plane)
1200 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1202 /* Add the buffer to the done buffers list */
1203 spin_lock_irqsave(&q->done_lock, flags);
1205 if (state != VB2_BUF_STATE_QUEUED)
1206 list_add_tail(&vb->done_entry, &q->done_list);
1207 atomic_dec(&q->owned_by_drv_count);
1208 spin_unlock_irqrestore(&q->done_lock, flags);
1210 if (state == VB2_BUF_STATE_QUEUED) {
1211 if (q->start_streaming_called)
1212 __enqueue_in_driver(vb);
1216 /* Inform any processes that may be waiting for buffers */
1217 wake_up(&q->done_wq);
1219 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1222 * vb2_discard_done() - discard all buffers marked as DONE
1223 * @q: videobuf2 queue
1225 * This function is intended to be used with suspend/resume operations. It
1226 * discards all 'done' buffers as they would be too old to be requested after
1229 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1230 * delayed works before calling this function to make sure no buffer will be
1231 * touched by the driver and/or hardware.
1233 void vb2_discard_done(struct vb2_queue *q)
1235 struct vb2_buffer *vb;
1236 unsigned long flags;
1238 spin_lock_irqsave(&q->done_lock, flags);
1239 list_for_each_entry(vb, &q->done_list, done_entry)
1240 vb->state = VB2_BUF_STATE_ERROR;
1241 spin_unlock_irqrestore(&q->done_lock, flags);
1243 EXPORT_SYMBOL_GPL(vb2_discard_done);
1245 static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
1247 static bool __check_once __read_mostly;
1252 __check_once = true;
1255 pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1256 if (vb->vb2_queue->allow_zero_bytesused)
1257 pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1259 pr_warn_once("use the actual size instead.\n");
1263 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1264 * v4l2_buffer by the userspace. The caller has already verified that struct
1265 * v4l2_buffer has a valid number of planes.
1267 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1268 struct v4l2_plane *v4l2_planes)
1272 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1273 if (b->memory == V4L2_MEMORY_USERPTR) {
1274 for (plane = 0; plane < vb->num_planes; ++plane) {
1275 v4l2_planes[plane].m.userptr =
1276 b->m.planes[plane].m.userptr;
1277 v4l2_planes[plane].length =
1278 b->m.planes[plane].length;
1281 if (b->memory == V4L2_MEMORY_DMABUF) {
1282 for (plane = 0; plane < vb->num_planes; ++plane) {
1283 v4l2_planes[plane].m.fd =
1284 b->m.planes[plane].m.fd;
1285 v4l2_planes[plane].length =
1286 b->m.planes[plane].length;
1290 /* Fill in driver-provided information for OUTPUT types */
1291 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1293 * Will have to go up to b->length when API starts
1294 * accepting variable number of planes.
1296 * If bytesused == 0 for the output buffer, then fall
1297 * back to the full buffer size. In that case
1298 * userspace clearly never bothered to set it and
1299 * it's a safe assumption that they really meant to
1300 * use the full plane sizes.
1302 * Some drivers, e.g. old codec drivers, use bytesused == 0
1303 * as a way to indicate that streaming is finished.
1304 * In that case, the driver should use the
1305 * allow_zero_bytesused flag to keep old userspace
1306 * applications working.
1308 for (plane = 0; plane < vb->num_planes; ++plane) {
1309 struct v4l2_plane *pdst = &v4l2_planes[plane];
1310 struct v4l2_plane *psrc = &b->m.planes[plane];
1312 if (psrc->bytesused == 0)
1313 vb2_warn_zero_bytesused(vb);
1315 if (vb->vb2_queue->allow_zero_bytesused)
1316 pdst->bytesused = psrc->bytesused;
1318 pdst->bytesused = psrc->bytesused ?
1319 psrc->bytesused : pdst->length;
1320 pdst->data_offset = psrc->data_offset;
1325 * Single-planar buffers do not use planes array,
1326 * so fill in relevant v4l2_buffer struct fields instead.
1327 * In videobuf we use our internal V4l2_planes struct for
1328 * single-planar buffers as well, for simplicity.
1330 * If bytesused == 0 for the output buffer, then fall back
1331 * to the full buffer size as that's a sensible default.
1333 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1334 * a way to indicate that streaming is finished. In that case,
1335 * the driver should use the allow_zero_bytesused flag to keep
1336 * old userspace applications working.
1338 if (b->memory == V4L2_MEMORY_USERPTR) {
1339 v4l2_planes[0].m.userptr = b->m.userptr;
1340 v4l2_planes[0].length = b->length;
1343 if (b->memory == V4L2_MEMORY_DMABUF) {
1344 v4l2_planes[0].m.fd = b->m.fd;
1345 v4l2_planes[0].length = b->length;
1348 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1349 if (b->bytesused == 0)
1350 vb2_warn_zero_bytesused(vb);
1352 if (vb->vb2_queue->allow_zero_bytesused)
1353 v4l2_planes[0].bytesused = b->bytesused;
1355 v4l2_planes[0].bytesused = b->bytesused ?
1356 b->bytesused : v4l2_planes[0].length;
1358 v4l2_planes[0].bytesused = 0;
1362 /* Zero flags that the vb2 core handles */
1363 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1364 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1365 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1367 * Non-COPY timestamps and non-OUTPUT queues will get
1368 * their timestamp and timestamp source flags from the
1371 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1374 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1376 * For output buffers mask out the timecode flag:
1377 * this will be handled later in vb2_internal_qbuf().
1378 * The 'field' is valid metadata for this output buffer
1379 * and so that needs to be copied here.
1381 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1382 vb->v4l2_buf.field = b->field;
1384 /* Zero any output buffer flags as this is a capture buffer */
1385 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1390 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1392 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1394 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1395 return call_vb_qop(vb, buf_prepare, vb);
1399 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1401 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1403 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1404 struct vb2_queue *q = vb->vb2_queue;
1408 enum dma_data_direction dma_dir =
1409 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1410 bool reacquired = vb->planes[0].mem_priv == NULL;
1412 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1413 /* Copy relevant information provided by the userspace */
1414 __fill_vb2_buffer(vb, b, planes);
1416 for (plane = 0; plane < vb->num_planes; ++plane) {
1417 /* Skip the plane if already verified */
1418 if (vb->v4l2_planes[plane].m.userptr &&
1419 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1420 && vb->v4l2_planes[plane].length == planes[plane].length)
1423 dprintk(3, "userspace address for plane %d changed, "
1424 "reacquiring memory\n", plane);
1426 /* Check if the provided plane buffer is large enough */
1427 if (planes[plane].length < q->plane_sizes[plane]) {
1428 dprintk(1, "provided buffer size %u is less than "
1429 "setup size %u for plane %d\n",
1430 planes[plane].length,
1431 q->plane_sizes[plane], plane);
1436 /* Release previously acquired memory if present */
1437 if (vb->planes[plane].mem_priv) {
1440 call_void_vb_qop(vb, buf_cleanup, vb);
1442 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1445 vb->planes[plane].mem_priv = NULL;
1446 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1448 /* Acquire each plane's memory */
1449 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1450 planes[plane].m.userptr,
1451 planes[plane].length, dma_dir);
1452 if (IS_ERR_OR_NULL(mem_priv)) {
1453 dprintk(1, "failed acquiring userspace "
1454 "memory for plane %d\n", plane);
1455 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1458 vb->planes[plane].mem_priv = mem_priv;
1462 * Now that everything is in order, copy relevant information
1463 * provided by userspace.
1465 for (plane = 0; plane < vb->num_planes; ++plane)
1466 vb->v4l2_planes[plane] = planes[plane];
1470 * One or more planes changed, so we must call buf_init to do
1471 * the driver-specific initialization on the newly acquired
1472 * buffer, if provided.
1474 ret = call_vb_qop(vb, buf_init, vb);
1476 dprintk(1, "buffer initialization failed\n");
1481 ret = call_vb_qop(vb, buf_prepare, vb);
1483 dprintk(1, "buffer preparation failed\n");
1484 call_void_vb_qop(vb, buf_cleanup, vb);
1490 /* In case of errors, release planes that were already acquired */
1491 for (plane = 0; plane < vb->num_planes; ++plane) {
1492 if (vb->planes[plane].mem_priv)
1493 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1494 vb->planes[plane].mem_priv = NULL;
1495 vb->v4l2_planes[plane].m.userptr = 0;
1496 vb->v4l2_planes[plane].length = 0;
1503 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1505 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1507 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1508 struct vb2_queue *q = vb->vb2_queue;
1512 enum dma_data_direction dma_dir =
1513 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1514 bool reacquired = vb->planes[0].mem_priv == NULL;
1516 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1517 /* Copy relevant information provided by the userspace */
1518 __fill_vb2_buffer(vb, b, planes);
1520 for (plane = 0; plane < vb->num_planes; ++plane) {
1521 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1523 if (IS_ERR_OR_NULL(dbuf)) {
1524 dprintk(1, "invalid dmabuf fd for plane %d\n",
1530 /* use DMABUF size if length is not provided */
1531 if (planes[plane].length == 0)
1532 planes[plane].length = dbuf->size;
1534 if (planes[plane].length < q->plane_sizes[plane]) {
1535 dprintk(1, "invalid dmabuf length for plane %d\n",
1541 /* Skip the plane if already verified */
1542 if (dbuf == vb->planes[plane].dbuf &&
1543 vb->v4l2_planes[plane].length == planes[plane].length) {
1548 dprintk(1, "buffer for plane %d changed\n", plane);
1552 call_void_vb_qop(vb, buf_cleanup, vb);
1555 /* Release previously acquired memory if present */
1556 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1557 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1559 /* Acquire each plane's memory */
1560 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1561 dbuf, planes[plane].length, dma_dir);
1562 if (IS_ERR(mem_priv)) {
1563 dprintk(1, "failed to attach dmabuf\n");
1564 ret = PTR_ERR(mem_priv);
1569 vb->planes[plane].dbuf = dbuf;
1570 vb->planes[plane].mem_priv = mem_priv;
1573 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1574 * really we want to do this just before the DMA, not while queueing
1577 for (plane = 0; plane < vb->num_planes; ++plane) {
1578 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1580 dprintk(1, "failed to map dmabuf for plane %d\n",
1584 vb->planes[plane].dbuf_mapped = 1;
1588 * Now that everything is in order, copy relevant information
1589 * provided by userspace.
1591 for (plane = 0; plane < vb->num_planes; ++plane)
1592 vb->v4l2_planes[plane] = planes[plane];
1596 * Call driver-specific initialization on the newly acquired buffer,
1599 ret = call_vb_qop(vb, buf_init, vb);
1601 dprintk(1, "buffer initialization failed\n");
1606 ret = call_vb_qop(vb, buf_prepare, vb);
1608 dprintk(1, "buffer preparation failed\n");
1609 call_void_vb_qop(vb, buf_cleanup, vb);
1615 /* In case of errors, release planes that were already acquired */
1616 __vb2_buf_dmabuf_put(vb);
1622 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1624 static void __enqueue_in_driver(struct vb2_buffer *vb)
1626 struct vb2_queue *q = vb->vb2_queue;
1629 vb->state = VB2_BUF_STATE_ACTIVE;
1630 atomic_inc(&q->owned_by_drv_count);
1633 for (plane = 0; plane < vb->num_planes; ++plane)
1634 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1636 call_void_vb_qop(vb, buf_queue, vb);
1639 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1641 struct vb2_queue *q = vb->vb2_queue;
1644 ret = __verify_length(vb, b);
1646 dprintk(1, "plane parameters verification failed: %d\n", ret);
1649 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1651 * If the format's field is ALTERNATE, then the buffer's field
1652 * should be either TOP or BOTTOM, not ALTERNATE since that
1653 * makes no sense. The driver has to know whether the
1654 * buffer represents a top or a bottom field in order to
1655 * program any DMA correctly. Using ALTERNATE is wrong, since
1656 * that just says that it is either a top or a bottom field,
1657 * but not which of the two it is.
1659 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1664 dprintk(1, "fatal error occurred on queue\n");
1668 vb->state = VB2_BUF_STATE_PREPARING;
1669 vb->v4l2_buf.timestamp.tv_sec = 0;
1670 vb->v4l2_buf.timestamp.tv_usec = 0;
1671 vb->v4l2_buf.sequence = 0;
1673 switch (q->memory) {
1674 case V4L2_MEMORY_MMAP:
1675 ret = __qbuf_mmap(vb, b);
1677 case V4L2_MEMORY_USERPTR:
1678 down_read(¤t->mm->mmap_sem);
1679 ret = __qbuf_userptr(vb, b);
1680 up_read(¤t->mm->mmap_sem);
1682 case V4L2_MEMORY_DMABUF:
1683 ret = __qbuf_dmabuf(vb, b);
1686 WARN(1, "Invalid queue type\n");
1691 dprintk(1, "buffer preparation failed: %d\n", ret);
1692 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1697 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1700 if (b->type != q->type) {
1701 dprintk(1, "%s: invalid buffer type\n", opname);
1705 if (b->index >= q->num_buffers) {
1706 dprintk(1, "%s: buffer index out of range\n", opname);
1710 if (q->bufs[b->index] == NULL) {
1711 /* Should never happen */
1712 dprintk(1, "%s: buffer is NULL\n", opname);
1716 if (b->memory != q->memory) {
1717 dprintk(1, "%s: invalid memory type\n", opname);
1721 return __verify_planes_array(q->bufs[b->index], b);
1725 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1726 * @q: videobuf2 queue
1727 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1730 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1732 * 1) verifies the passed buffer,
1733 * 2) calls buf_prepare callback in the driver (if provided), in which
1734 * driver-specific buffer initialization can be performed,
1736 * The return values from this function are intended to be directly returned
1737 * from vidioc_prepare_buf handler in driver.
1739 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1741 struct vb2_buffer *vb;
1744 if (vb2_fileio_is_active(q)) {
1745 dprintk(1, "file io in progress\n");
1749 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1753 vb = q->bufs[b->index];
1754 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1755 dprintk(1, "invalid buffer state %d\n",
1760 ret = __buf_prepare(vb, b);
1762 /* Fill buffer information for the userspace */
1763 __fill_v4l2_buffer(vb, b);
1765 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1769 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1772 * vb2_start_streaming() - Attempt to start streaming.
1773 * @q: videobuf2 queue
1775 * Attempt to start streaming. When this function is called there must be
1776 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1777 * number of buffers required for the DMA engine to function). If the
1778 * @start_streaming op fails it is supposed to return all the driver-owned
1779 * buffers back to vb2 in state QUEUED. Check if that happened and if
1780 * not warn and reclaim them forcefully.
1782 static int vb2_start_streaming(struct vb2_queue *q)
1784 struct vb2_buffer *vb;
1788 * If any buffers were queued before streamon,
1789 * we can now pass them to driver for processing.
1791 list_for_each_entry(vb, &q->queued_list, queued_entry)
1792 __enqueue_in_driver(vb);
1794 /* Tell the driver to start streaming */
1795 q->start_streaming_called = 1;
1796 ret = call_qop(q, start_streaming, q,
1797 atomic_read(&q->owned_by_drv_count));
1801 q->start_streaming_called = 0;
1803 dprintk(1, "driver refused to start streaming\n");
1805 * If you see this warning, then the driver isn't cleaning up properly
1806 * after a failed start_streaming(). See the start_streaming()
1807 * documentation in videobuf2-core.h for more information how buffers
1808 * should be returned to vb2 in start_streaming().
1810 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1814 * Forcefully reclaim buffers if the driver did not
1815 * correctly return them to vb2.
1817 for (i = 0; i < q->num_buffers; ++i) {
1819 if (vb->state == VB2_BUF_STATE_ACTIVE)
1820 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1822 /* Must be zero now */
1823 WARN_ON(atomic_read(&q->owned_by_drv_count));
1826 * If done_list is not empty, then start_streaming() didn't call
1827 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1830 WARN_ON(!list_empty(&q->done_list));
1834 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1836 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1837 struct vb2_buffer *vb;
1842 vb = q->bufs[b->index];
1844 switch (vb->state) {
1845 case VB2_BUF_STATE_DEQUEUED:
1846 ret = __buf_prepare(vb, b);
1850 case VB2_BUF_STATE_PREPARED:
1852 case VB2_BUF_STATE_PREPARING:
1853 dprintk(1, "buffer still being prepared\n");
1856 dprintk(1, "invalid buffer state %d\n", vb->state);
1861 * Add to the queued buffers list, a buffer will stay on it until
1862 * dequeued in dqbuf.
1864 list_add_tail(&vb->queued_entry, &q->queued_list);
1866 q->waiting_for_buffers = false;
1867 vb->state = VB2_BUF_STATE_QUEUED;
1868 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1870 * For output buffers copy the timestamp if needed,
1871 * and the timecode field and flag if needed.
1873 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1874 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1875 vb->v4l2_buf.timestamp = b->timestamp;
1876 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1877 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1878 vb->v4l2_buf.timecode = b->timecode;
1882 * If already streaming, give the buffer to driver for processing.
1883 * If not, the buffer will be given to driver on next streamon.
1885 if (q->start_streaming_called)
1886 __enqueue_in_driver(vb);
1888 /* Fill buffer information for the userspace */
1889 __fill_v4l2_buffer(vb, b);
1892 * If streamon has been called, and we haven't yet called
1893 * start_streaming() since not enough buffers were queued, and
1894 * we now have reached the minimum number of queued buffers,
1895 * then we can finally call start_streaming().
1897 if (q->streaming && !q->start_streaming_called &&
1898 q->queued_count >= q->min_buffers_needed) {
1899 ret = vb2_start_streaming(q);
1904 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1909 * vb2_qbuf() - Queue a buffer from userspace
1910 * @q: videobuf2 queue
1911 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1914 * Should be called from vidioc_qbuf ioctl handler of a driver.
1916 * 1) verifies the passed buffer,
1917 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1918 * which driver-specific buffer initialization can be performed,
1919 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1920 * callback for processing.
1922 * The return values from this function are intended to be directly returned
1923 * from vidioc_qbuf handler in driver.
1925 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1927 if (vb2_fileio_is_active(q)) {
1928 dprintk(1, "file io in progress\n");
1932 return vb2_internal_qbuf(q, b);
1934 EXPORT_SYMBOL_GPL(vb2_qbuf);
1937 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1940 * Will sleep if required for nonblocking == false.
1942 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1945 * All operations on vb_done_list are performed under done_lock
1946 * spinlock protection. However, buffers may be removed from
1947 * it and returned to userspace only while holding both driver's
1948 * lock and the done_lock spinlock. Thus we can be sure that as
1949 * long as we hold the driver's lock, the list will remain not
1950 * empty if list_empty() check succeeds.
1956 if (!q->streaming) {
1957 dprintk(1, "streaming off, will not wait for buffers\n");
1962 dprintk(1, "Queue in error state, will not wait for buffers\n");
1966 if (q->last_buffer_dequeued) {
1967 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1971 if (!list_empty(&q->done_list)) {
1973 * Found a buffer that we were waiting for.
1979 dprintk(1, "nonblocking and no buffers to dequeue, "
1985 * We are streaming and blocking, wait for another buffer to
1986 * become ready or for streamoff. Driver's lock is released to
1987 * allow streamoff or qbuf to be called while waiting.
1989 call_void_qop(q, wait_prepare, q);
1992 * All locks have been released, it is safe to sleep now.
1994 dprintk(3, "will sleep waiting for buffers\n");
1995 ret = wait_event_interruptible(q->done_wq,
1996 !list_empty(&q->done_list) || !q->streaming ||
2000 * We need to reevaluate both conditions again after reacquiring
2001 * the locks or return an error if one occurred.
2003 call_void_qop(q, wait_finish, q);
2005 dprintk(1, "sleep was interrupted\n");
2013 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2015 * Will sleep if required for nonblocking == false.
2017 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
2018 struct v4l2_buffer *b, int nonblocking)
2020 unsigned long flags;
2024 * Wait for at least one buffer to become available on the done_list.
2026 ret = __vb2_wait_for_done_vb(q, nonblocking);
2031 * Driver's lock has been held since we last verified that done_list
2032 * is not empty, so no need for another list_empty(done_list) check.
2034 spin_lock_irqsave(&q->done_lock, flags);
2035 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
2037 * Only remove the buffer from done_list if v4l2_buffer can handle all
2040 ret = __verify_planes_array(*vb, b);
2042 list_del(&(*vb)->done_entry);
2043 spin_unlock_irqrestore(&q->done_lock, flags);
2049 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2050 * @q: videobuf2 queue
2052 * This function will wait until all buffers that have been given to the driver
2053 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2054 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2055 * taken, for example from stop_streaming() callback.
2057 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2059 if (!q->streaming) {
2060 dprintk(1, "streaming off, will not wait for buffers\n");
2064 if (q->start_streaming_called)
2065 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2068 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2071 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2073 static void __vb2_dqbuf(struct vb2_buffer *vb)
2075 struct vb2_queue *q = vb->vb2_queue;
2078 /* nothing to do if the buffer is already dequeued */
2079 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2082 vb->state = VB2_BUF_STATE_DEQUEUED;
2084 /* unmap DMABUF buffer */
2085 if (q->memory == V4L2_MEMORY_DMABUF)
2086 for (i = 0; i < vb->num_planes; ++i) {
2087 if (!vb->planes[i].dbuf_mapped)
2089 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2090 vb->planes[i].dbuf_mapped = 0;
2094 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2096 struct vb2_buffer *vb = NULL;
2099 if (b->type != q->type) {
2100 dprintk(1, "invalid buffer type\n");
2103 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2107 switch (vb->state) {
2108 case VB2_BUF_STATE_DONE:
2109 dprintk(3, "returning done buffer\n");
2111 case VB2_BUF_STATE_ERROR:
2112 dprintk(3, "returning done buffer with errors\n");
2115 dprintk(1, "invalid buffer state\n");
2119 call_void_vb_qop(vb, buf_finish, vb);
2121 /* Fill buffer information for the userspace */
2122 __fill_v4l2_buffer(vb, b);
2123 /* Remove from videobuf queue */
2124 list_del(&vb->queued_entry);
2126 if (!V4L2_TYPE_IS_OUTPUT(q->type) &&
2127 vb->v4l2_buf.flags & V4L2_BUF_FLAG_LAST)
2128 q->last_buffer_dequeued = true;
2129 /* go back to dequeued state */
2132 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2133 vb->v4l2_buf.index, vb->state);
2139 * vb2_dqbuf() - Dequeue a buffer to the userspace
2140 * @q: videobuf2 queue
2141 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2143 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2144 * buffers ready for dequeuing are present. Normally the driver
2145 * would be passing (file->f_flags & O_NONBLOCK) here
2147 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2149 * 1) verifies the passed buffer,
2150 * 2) calls buf_finish callback in the driver (if provided), in which
2151 * driver can perform any additional operations that may be required before
2152 * returning the buffer to userspace, such as cache sync,
2153 * 3) the buffer struct members are filled with relevant information for
2156 * The return values from this function are intended to be directly returned
2157 * from vidioc_dqbuf handler in driver.
2159 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2161 if (vb2_fileio_is_active(q)) {
2162 dprintk(1, "file io in progress\n");
2165 return vb2_internal_dqbuf(q, b, nonblocking);
2167 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2170 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2172 * Removes all queued buffers from driver's queue and all buffers queued by
2173 * userspace from videobuf's queue. Returns to state after reqbufs.
2175 static void __vb2_queue_cancel(struct vb2_queue *q)
2180 * Tell driver to stop all transactions and release all queued
2183 if (q->start_streaming_called)
2184 call_void_qop(q, stop_streaming, q);
2187 * If you see this warning, then the driver isn't cleaning up properly
2188 * in stop_streaming(). See the stop_streaming() documentation in
2189 * videobuf2-core.h for more information how buffers should be returned
2190 * to vb2 in stop_streaming().
2192 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2193 for (i = 0; i < q->num_buffers; ++i)
2194 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2195 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2196 /* Must be zero now */
2197 WARN_ON(atomic_read(&q->owned_by_drv_count));
2201 q->start_streaming_called = 0;
2202 q->queued_count = 0;
2206 * Remove all buffers from videobuf's list...
2208 INIT_LIST_HEAD(&q->queued_list);
2210 * ...and done list; userspace will not receive any buffers it
2211 * has not already dequeued before initiating cancel.
2213 INIT_LIST_HEAD(&q->done_list);
2214 atomic_set(&q->owned_by_drv_count, 0);
2215 wake_up_all(&q->done_wq);
2218 * Reinitialize all buffers for next use.
2219 * Make sure to call buf_finish for any queued buffers. Normally
2220 * that's done in dqbuf, but that's not going to happen when we
2221 * cancel the whole queue. Note: this code belongs here, not in
2222 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2223 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2224 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2226 for (i = 0; i < q->num_buffers; ++i) {
2227 struct vb2_buffer *vb = q->bufs[i];
2229 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2230 vb->state = VB2_BUF_STATE_PREPARED;
2231 call_void_vb_qop(vb, buf_finish, vb);
2237 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2241 if (type != q->type) {
2242 dprintk(1, "invalid stream type\n");
2247 dprintk(3, "already streaming\n");
2251 if (!q->num_buffers) {
2252 dprintk(1, "no buffers have been allocated\n");
2256 if (q->num_buffers < q->min_buffers_needed) {
2257 dprintk(1, "need at least %u allocated buffers\n",
2258 q->min_buffers_needed);
2263 * Tell driver to start streaming provided sufficient buffers
2266 if (q->queued_count >= q->min_buffers_needed) {
2267 ret = vb2_start_streaming(q);
2269 __vb2_queue_cancel(q);
2276 dprintk(3, "successful\n");
2281 * vb2_queue_error() - signal a fatal error on the queue
2282 * @q: videobuf2 queue
2284 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2285 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2286 * buffers will return -EIO.
2288 * The error flag will be cleared when cancelling the queue, either from
2289 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2290 * function before starting the stream, otherwise the error flag will remain set
2291 * until the queue is released when closing the device node.
2293 void vb2_queue_error(struct vb2_queue *q)
2297 wake_up_all(&q->done_wq);
2299 EXPORT_SYMBOL_GPL(vb2_queue_error);
2302 * vb2_streamon - start streaming
2303 * @q: videobuf2 queue
2304 * @type: type argument passed from userspace to vidioc_streamon handler
2306 * Should be called from vidioc_streamon handler of a driver.
2308 * 1) verifies current state
2309 * 2) passes any previously queued buffers to the driver and starts streaming
2311 * The return values from this function are intended to be directly returned
2312 * from vidioc_streamon handler in the driver.
2314 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2316 if (vb2_fileio_is_active(q)) {
2317 dprintk(1, "file io in progress\n");
2320 return vb2_internal_streamon(q, type);
2322 EXPORT_SYMBOL_GPL(vb2_streamon);
2324 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2326 if (type != q->type) {
2327 dprintk(1, "invalid stream type\n");
2332 * Cancel will pause streaming and remove all buffers from the driver
2333 * and videobuf, effectively returning control over them to userspace.
2335 * Note that we do this even if q->streaming == 0: if you prepare or
2336 * queue buffers, and then call streamoff without ever having called
2337 * streamon, you would still expect those buffers to be returned to
2338 * their normal dequeued state.
2340 __vb2_queue_cancel(q);
2341 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2342 q->last_buffer_dequeued = false;
2344 dprintk(3, "successful\n");
2349 * vb2_streamoff - stop streaming
2350 * @q: videobuf2 queue
2351 * @type: type argument passed from userspace to vidioc_streamoff handler
2353 * Should be called from vidioc_streamoff handler of a driver.
2355 * 1) verifies current state,
2356 * 2) stop streaming and dequeues any queued buffers, including those previously
2357 * passed to the driver (after waiting for the driver to finish).
2359 * This call can be used for pausing playback.
2360 * The return values from this function are intended to be directly returned
2361 * from vidioc_streamoff handler in the driver
2363 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2365 if (vb2_fileio_is_active(q)) {
2366 dprintk(1, "file io in progress\n");
2369 return vb2_internal_streamoff(q, type);
2371 EXPORT_SYMBOL_GPL(vb2_streamoff);
2374 * __find_plane_by_offset() - find plane associated with the given offset off
2376 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2377 unsigned int *_buffer, unsigned int *_plane)
2379 struct vb2_buffer *vb;
2380 unsigned int buffer, plane;
2383 * Go over all buffers and their planes, comparing the given offset
2384 * with an offset assigned to each plane. If a match is found,
2385 * return its buffer and plane numbers.
2387 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2388 vb = q->bufs[buffer];
2390 for (plane = 0; plane < vb->num_planes; ++plane) {
2391 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2403 * vb2_expbuf() - Export a buffer as a file descriptor
2404 * @q: videobuf2 queue
2405 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2408 * The return values from this function are intended to be directly returned
2409 * from vidioc_expbuf handler in driver.
2411 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2413 struct vb2_buffer *vb = NULL;
2414 struct vb2_plane *vb_plane;
2416 struct dma_buf *dbuf;
2418 if (q->memory != V4L2_MEMORY_MMAP) {
2419 dprintk(1, "queue is not currently set up for mmap\n");
2423 if (!q->mem_ops->get_dmabuf) {
2424 dprintk(1, "queue does not support DMA buffer exporting\n");
2428 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2429 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2433 if (eb->type != q->type) {
2434 dprintk(1, "invalid buffer type\n");
2438 if (eb->index >= q->num_buffers) {
2439 dprintk(1, "buffer index out of range\n");
2443 vb = q->bufs[eb->index];
2445 if (eb->plane >= vb->num_planes) {
2446 dprintk(1, "buffer plane out of range\n");
2450 if (vb2_fileio_is_active(q)) {
2451 dprintk(1, "expbuf: file io in progress\n");
2455 vb_plane = &vb->planes[eb->plane];
2457 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2458 if (IS_ERR_OR_NULL(dbuf)) {
2459 dprintk(1, "failed to export buffer %d, plane %d\n",
2460 eb->index, eb->plane);
2464 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2466 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2467 eb->index, eb->plane, ret);
2472 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2473 eb->index, eb->plane, ret);
2478 EXPORT_SYMBOL_GPL(vb2_expbuf);
2481 * vb2_mmap() - map video buffers into application address space
2482 * @q: videobuf2 queue
2483 * @vma: vma passed to the mmap file operation handler in the driver
2485 * Should be called from mmap file operation handler of a driver.
2486 * This function maps one plane of one of the available video buffers to
2487 * userspace. To map whole video memory allocated on reqbufs, this function
2488 * has to be called once per each plane per each buffer previously allocated.
2490 * When the userspace application calls mmap, it passes to it an offset returned
2491 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2492 * a "cookie", which is then used to identify the plane to be mapped.
2493 * This function finds a plane with a matching offset and a mapping is performed
2494 * by the means of a provided memory operation.
2496 * The return values from this function are intended to be directly returned
2497 * from the mmap handler in driver.
2499 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2501 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2502 struct vb2_buffer *vb;
2503 unsigned int buffer = 0, plane = 0;
2505 unsigned long length;
2507 if (q->memory != V4L2_MEMORY_MMAP) {
2508 dprintk(1, "queue is not currently set up for mmap\n");
2513 * Check memory area access mode.
2515 if (!(vma->vm_flags & VM_SHARED)) {
2516 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2519 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2520 if (!(vma->vm_flags & VM_WRITE)) {
2521 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2525 if (!(vma->vm_flags & VM_READ)) {
2526 dprintk(1, "invalid vma flags, VM_READ needed\n");
2530 if (vb2_fileio_is_active(q)) {
2531 dprintk(1, "mmap: file io in progress\n");
2536 * Find the plane corresponding to the offset passed by userspace.
2538 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2542 vb = q->bufs[buffer];
2545 * MMAP requires page_aligned buffers.
2546 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2547 * so, we need to do the same here.
2549 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2550 if (length < (vma->vm_end - vma->vm_start)) {
2552 "MMAP invalid, as it would overflow buffer length\n");
2556 mutex_lock(&q->mmap_lock);
2557 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2558 mutex_unlock(&q->mmap_lock);
2562 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2565 EXPORT_SYMBOL_GPL(vb2_mmap);
2568 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2571 unsigned long pgoff,
2572 unsigned long flags)
2574 unsigned long off = pgoff << PAGE_SHIFT;
2575 struct vb2_buffer *vb;
2576 unsigned int buffer, plane;
2580 if (q->memory != V4L2_MEMORY_MMAP) {
2581 dprintk(1, "queue is not currently set up for mmap\n");
2586 * Find the plane corresponding to the offset passed by userspace.
2588 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2592 vb = q->bufs[buffer];
2594 vaddr = vb2_plane_vaddr(vb, plane);
2595 return vaddr ? (unsigned long)vaddr : -EINVAL;
2597 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2600 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2601 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2604 * vb2_poll() - implements poll userspace operation
2605 * @q: videobuf2 queue
2606 * @file: file argument passed to the poll file operation handler
2607 * @wait: wait argument passed to the poll file operation handler
2609 * This function implements poll file operation handler for a driver.
2610 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2611 * be informed that the file descriptor of a video device is available for
2613 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2614 * will be reported as available for writing.
2616 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2619 * The return values from this function are intended to be directly returned
2620 * from poll handler in driver.
2622 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2624 struct video_device *vfd = video_devdata(file);
2625 unsigned long req_events = poll_requested_events(wait);
2626 struct vb2_buffer *vb = NULL;
2627 unsigned int res = 0;
2628 unsigned long flags;
2630 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2631 struct v4l2_fh *fh = file->private_data;
2633 if (v4l2_event_pending(fh))
2635 else if (req_events & POLLPRI)
2636 poll_wait(file, &fh->wait, wait);
2639 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2641 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2645 * Start file I/O emulator only if streaming API has not been used yet.
2647 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2648 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2649 (req_events & (POLLIN | POLLRDNORM))) {
2650 if (__vb2_init_fileio(q, 1))
2651 return res | POLLERR;
2653 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2654 (req_events & (POLLOUT | POLLWRNORM))) {
2655 if (__vb2_init_fileio(q, 0))
2656 return res | POLLERR;
2658 * Write to OUTPUT queue can be done immediately.
2660 return res | POLLOUT | POLLWRNORM;
2665 * There is nothing to wait for if the queue isn't streaming, or if the
2666 * error flag is set.
2668 if (!vb2_is_streaming(q) || q->error)
2669 return res | POLLERR;
2671 * For compatibility with vb1: if QBUF hasn't been called yet, then
2672 * return POLLERR as well. This only affects capture queues, output
2673 * queues will always initialize waiting_for_buffers to false.
2675 if (q->waiting_for_buffers)
2676 return res | POLLERR;
2679 * For output streams you can write as long as there are fewer buffers
2680 * queued than there are buffers available.
2682 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2683 return res | POLLOUT | POLLWRNORM;
2685 if (list_empty(&q->done_list)) {
2687 * If the last buffer was dequeued from a capture queue,
2688 * return immediately. DQBUF will return -EPIPE.
2690 if (q->last_buffer_dequeued)
2691 return res | POLLIN | POLLRDNORM;
2693 poll_wait(file, &q->done_wq, wait);
2697 * Take first buffer available for dequeuing.
2699 spin_lock_irqsave(&q->done_lock, flags);
2700 if (!list_empty(&q->done_list))
2701 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2703 spin_unlock_irqrestore(&q->done_lock, flags);
2705 if (vb && (vb->state == VB2_BUF_STATE_DONE
2706 || vb->state == VB2_BUF_STATE_ERROR)) {
2707 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2708 res | POLLOUT | POLLWRNORM :
2709 res | POLLIN | POLLRDNORM;
2713 EXPORT_SYMBOL_GPL(vb2_poll);
2716 * vb2_queue_init() - initialize a videobuf2 queue
2717 * @q: videobuf2 queue; this structure should be allocated in driver
2719 * The vb2_queue structure should be allocated by the driver. The driver is
2720 * responsible of clearing it's content and setting initial values for some
2721 * required entries before calling this function.
2722 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2723 * to the struct vb2_queue description in include/media/videobuf2-core.h
2724 * for more information.
2726 int vb2_queue_init(struct vb2_queue *q)
2733 WARN_ON(!q->mem_ops) ||
2734 WARN_ON(!q->type) ||
2735 WARN_ON(!q->io_modes) ||
2736 WARN_ON(!q->ops->queue_setup) ||
2737 WARN_ON(!q->ops->buf_queue) ||
2738 WARN_ON(q->timestamp_flags &
2739 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2740 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2743 /* Warn that the driver should choose an appropriate timestamp type */
2744 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2745 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2747 INIT_LIST_HEAD(&q->queued_list);
2748 INIT_LIST_HEAD(&q->done_list);
2749 spin_lock_init(&q->done_lock);
2750 mutex_init(&q->mmap_lock);
2751 init_waitqueue_head(&q->done_wq);
2753 if (q->buf_struct_size == 0)
2754 q->buf_struct_size = sizeof(struct vb2_buffer);
2758 EXPORT_SYMBOL_GPL(vb2_queue_init);
2761 * vb2_queue_release() - stop streaming, release the queue and free memory
2762 * @q: videobuf2 queue
2764 * This function stops streaming and performs necessary clean ups, including
2765 * freeing video buffer memory. The driver is responsible for freeing
2766 * the vb2_queue structure itself.
2768 void vb2_queue_release(struct vb2_queue *q)
2770 __vb2_cleanup_fileio(q);
2771 __vb2_queue_cancel(q);
2772 mutex_lock(&q->mmap_lock);
2773 __vb2_queue_free(q, q->num_buffers);
2774 mutex_unlock(&q->mmap_lock);
2776 EXPORT_SYMBOL_GPL(vb2_queue_release);
2779 * struct vb2_fileio_buf - buffer context used by file io emulator
2781 * vb2 provides a compatibility layer and emulator of file io (read and
2782 * write) calls on top of streaming API. This structure is used for
2783 * tracking context related to the buffers.
2785 struct vb2_fileio_buf {
2789 unsigned int queued:1;
2793 * struct vb2_fileio_data - queue context used by file io emulator
2795 * @cur_index: the index of the buffer currently being read from or
2796 * written to. If equal to q->num_buffers then a new buffer
2798 * @initial_index: in the read() case all buffers are queued up immediately
2799 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2800 * buffers. However, in the write() case no buffers are initially
2801 * queued, instead whenever a buffer is full it is queued up by
2802 * __vb2_perform_fileio(). Only once all available buffers have
2803 * been queued up will __vb2_perform_fileio() start to dequeue
2804 * buffers. This means that initially __vb2_perform_fileio()
2805 * needs to know what buffer index to use when it is queuing up
2806 * the buffers for the first time. That initial index is stored
2807 * in this field. Once it is equal to q->num_buffers all
2808 * available buffers have been queued and __vb2_perform_fileio()
2809 * should start the normal dequeue/queue cycle.
2811 * vb2 provides a compatibility layer and emulator of file io (read and
2812 * write) calls on top of streaming API. For proper operation it required
2813 * this structure to save the driver state between each call of the read
2814 * or write function.
2816 struct vb2_fileio_data {
2817 struct v4l2_requestbuffers req;
2818 struct v4l2_plane p;
2819 struct v4l2_buffer b;
2820 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2821 unsigned int cur_index;
2822 unsigned int initial_index;
2823 unsigned int q_count;
2824 unsigned int dq_count;
2825 unsigned read_once:1;
2826 unsigned write_immediately:1;
2830 * __vb2_init_fileio() - initialize file io emulator
2831 * @q: videobuf2 queue
2832 * @read: mode selector (1 means read, 0 means write)
2834 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2836 struct vb2_fileio_data *fileio;
2838 unsigned int count = 0;
2843 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2844 (!read && !(q->io_modes & VB2_WRITE))))
2848 * Check if device supports mapping buffers to kernel virtual space.
2850 if (!q->mem_ops->vaddr)
2854 * Check if streaming api has not been already activated.
2856 if (q->streaming || q->num_buffers > 0)
2860 * Start with count 1, driver can increase it in queue_setup()
2864 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2865 (read) ? "read" : "write", count, q->fileio_read_once,
2866 q->fileio_write_immediately);
2868 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2872 fileio->read_once = q->fileio_read_once;
2873 fileio->write_immediately = q->fileio_write_immediately;
2876 * Request buffers and use MMAP type to force driver
2877 * to allocate buffers by itself.
2879 fileio->req.count = count;
2880 fileio->req.memory = V4L2_MEMORY_MMAP;
2881 fileio->req.type = q->type;
2883 ret = __reqbufs(q, &fileio->req);
2888 * Check if plane_count is correct
2889 * (multiplane buffers are not supported).
2891 if (q->bufs[0]->num_planes != 1) {
2897 * Get kernel address of each buffer.
2899 for (i = 0; i < q->num_buffers; i++) {
2900 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2901 if (fileio->bufs[i].vaddr == NULL) {
2905 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2909 * Read mode requires pre queuing of all buffers.
2912 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2915 * Queue all buffers.
2917 for (i = 0; i < q->num_buffers; i++) {
2918 struct v4l2_buffer *b = &fileio->b;
2920 memset(b, 0, sizeof(*b));
2922 if (is_multiplanar) {
2923 memset(&fileio->p, 0, sizeof(fileio->p));
2924 b->m.planes = &fileio->p;
2927 b->memory = q->memory;
2929 ret = vb2_internal_qbuf(q, b);
2932 fileio->bufs[i].queued = 1;
2935 * All buffers have been queued, so mark that by setting
2936 * initial_index to q->num_buffers
2938 fileio->initial_index = q->num_buffers;
2939 fileio->cur_index = q->num_buffers;
2945 ret = vb2_internal_streamon(q, q->type);
2952 fileio->req.count = 0;
2953 __reqbufs(q, &fileio->req);
2962 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2963 * @q: videobuf2 queue
2965 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2967 struct vb2_fileio_data *fileio = q->fileio;
2970 vb2_internal_streamoff(q, q->type);
2972 fileio->req.count = 0;
2973 vb2_reqbufs(q, &fileio->req);
2975 dprintk(3, "file io emulator closed\n");
2981 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2982 * @q: videobuf2 queue
2983 * @data: pointed to target userspace buffer
2984 * @count: number of bytes to read or write
2985 * @ppos: file handle position tracking pointer
2986 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2987 * @read: access mode selector (1 means read, 0 means write)
2989 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2990 loff_t *ppos, int nonblock, int read)
2992 struct vb2_fileio_data *fileio;
2993 struct vb2_fileio_buf *buf;
2994 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2996 * When using write() to write data to an output video node the vb2 core
2997 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2998 * else is able to provide this information with the write() operation.
3000 bool set_timestamp = !read &&
3001 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3002 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3005 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
3006 read ? "read" : "write", (long)*ppos, count,
3007 nonblock ? "non" : "");
3013 * Initialize emulator on first call.
3015 if (!vb2_fileio_is_active(q)) {
3016 ret = __vb2_init_fileio(q, read);
3017 dprintk(3, "vb2_init_fileio result: %d\n", ret);
3024 * Check if we need to dequeue the buffer.
3026 index = fileio->cur_index;
3027 if (index >= q->num_buffers) {
3029 * Call vb2_dqbuf to get buffer back.
3031 memset(&fileio->b, 0, sizeof(fileio->b));
3032 fileio->b.type = q->type;
3033 fileio->b.memory = q->memory;
3034 if (is_multiplanar) {
3035 memset(&fileio->p, 0, sizeof(fileio->p));
3036 fileio->b.m.planes = &fileio->p;
3037 fileio->b.length = 1;
3039 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
3040 dprintk(5, "vb2_dqbuf result: %d\n", ret);
3043 fileio->dq_count += 1;
3045 fileio->cur_index = index = fileio->b.index;
3046 buf = &fileio->bufs[index];
3049 * Get number of bytes filled by the driver
3053 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
3054 : vb2_plane_size(q->bufs[index], 0);
3055 /* Compensate for data_offset on read in the multiplanar case. */
3056 if (is_multiplanar && read &&
3057 fileio->b.m.planes[0].data_offset < buf->size) {
3058 buf->pos = fileio->b.m.planes[0].data_offset;
3059 buf->size -= buf->pos;
3062 buf = &fileio->bufs[index];
3066 * Limit count on last few bytes of the buffer.
3068 if (buf->pos + count > buf->size) {
3069 count = buf->size - buf->pos;
3070 dprintk(5, "reducing read count: %zd\n", count);
3074 * Transfer data to userspace.
3076 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3077 count, index, buf->pos);
3079 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3081 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3083 dprintk(3, "error copying data\n");
3094 * Queue next buffer if required.
3096 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
3098 * Check if this is the last buffer to read.
3100 if (read && fileio->read_once && fileio->dq_count == 1) {
3101 dprintk(3, "read limit reached\n");
3102 return __vb2_cleanup_fileio(q);
3106 * Call vb2_qbuf and give buffer to the driver.
3108 memset(&fileio->b, 0, sizeof(fileio->b));
3109 fileio->b.type = q->type;
3110 fileio->b.memory = q->memory;
3111 fileio->b.index = index;
3112 fileio->b.bytesused = buf->pos;
3113 if (is_multiplanar) {
3114 memset(&fileio->p, 0, sizeof(fileio->p));
3115 fileio->p.bytesused = buf->pos;
3116 fileio->b.m.planes = &fileio->p;
3117 fileio->b.length = 1;
3120 v4l2_get_timestamp(&fileio->b.timestamp);
3121 ret = vb2_internal_qbuf(q, &fileio->b);
3122 dprintk(5, "vb2_dbuf result: %d\n", ret);
3127 * Buffer has been queued, update the status
3131 buf->size = vb2_plane_size(q->bufs[index], 0);
3132 fileio->q_count += 1;
3134 * If we are queuing up buffers for the first time, then
3135 * increase initial_index by one.
3137 if (fileio->initial_index < q->num_buffers)
3138 fileio->initial_index++;
3140 * The next buffer to use is either a buffer that's going to be
3141 * queued for the first time (initial_index < q->num_buffers)
3142 * or it is equal to q->num_buffers, meaning that the next
3143 * time we need to dequeue a buffer since we've now queued up
3144 * all the 'first time' buffers.
3146 fileio->cur_index = fileio->initial_index;
3150 * Return proper number of bytes processed.
3157 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3158 loff_t *ppos, int nonblocking)
3160 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3162 EXPORT_SYMBOL_GPL(vb2_read);
3164 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3165 loff_t *ppos, int nonblocking)
3167 return __vb2_perform_fileio(q, (char __user *) data, count,
3168 ppos, nonblocking, 0);
3170 EXPORT_SYMBOL_GPL(vb2_write);
3172 struct vb2_threadio_data {
3173 struct task_struct *thread;
3179 static int vb2_thread(void *data)
3181 struct vb2_queue *q = data;
3182 struct vb2_threadio_data *threadio = q->threadio;
3183 struct vb2_fileio_data *fileio = q->fileio;
3184 bool set_timestamp = false;
3189 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3190 prequeue = q->num_buffers;
3192 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3193 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3199 struct vb2_buffer *vb;
3202 * Call vb2_dqbuf to get buffer back.
3204 memset(&fileio->b, 0, sizeof(fileio->b));
3205 fileio->b.type = q->type;
3206 fileio->b.memory = q->memory;
3208 fileio->b.index = index++;
3211 call_void_qop(q, wait_finish, q);
3212 if (!threadio->stop)
3213 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3214 call_void_qop(q, wait_prepare, q);
3215 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3217 if (ret || threadio->stop)
3221 vb = q->bufs[fileio->b.index];
3222 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3223 if (threadio->fnc(vb, threadio->priv))
3225 call_void_qop(q, wait_finish, q);
3227 v4l2_get_timestamp(&fileio->b.timestamp);
3228 if (!threadio->stop)
3229 ret = vb2_internal_qbuf(q, &fileio->b);
3230 call_void_qop(q, wait_prepare, q);
3231 if (ret || threadio->stop)
3235 /* Hmm, linux becomes *very* unhappy without this ... */
3236 while (!kthread_should_stop()) {
3237 set_current_state(TASK_INTERRUPTIBLE);
3244 * This function should not be used for anything else but the videobuf2-dvb
3245 * support. If you think you have another good use-case for this, then please
3246 * contact the linux-media mailinglist first.
3248 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3249 const char *thread_name)
3251 struct vb2_threadio_data *threadio;
3258 if (WARN_ON(q->fileio))
3261 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3262 if (threadio == NULL)
3264 threadio->fnc = fnc;
3265 threadio->priv = priv;
3267 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3268 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3271 q->threadio = threadio;
3272 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3273 if (IS_ERR(threadio->thread)) {
3274 ret = PTR_ERR(threadio->thread);
3275 threadio->thread = NULL;
3281 __vb2_cleanup_fileio(q);
3286 EXPORT_SYMBOL_GPL(vb2_thread_start);
3288 int vb2_thread_stop(struct vb2_queue *q)
3290 struct vb2_threadio_data *threadio = q->threadio;
3293 if (threadio == NULL)
3295 threadio->stop = true;
3296 /* Wake up all pending sleeps in the thread */
3298 err = kthread_stop(threadio->thread);
3299 __vb2_cleanup_fileio(q);
3300 threadio->thread = NULL;
3305 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3308 * The following functions are not part of the vb2 core API, but are helper
3309 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3310 * and struct vb2_ops.
3311 * They contain boilerplate code that most if not all drivers have to do
3312 * and so they simplify the driver code.
3315 /* The queue is busy if there is a owner and you are not that owner. */
3316 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3318 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3321 /* vb2 ioctl helpers */
3323 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3324 struct v4l2_requestbuffers *p)
3326 struct video_device *vdev = video_devdata(file);
3327 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3331 if (vb2_queue_is_busy(vdev, file))
3333 res = __reqbufs(vdev->queue, p);
3334 /* If count == 0, then the owner has released all buffers and he
3335 is no longer owner of the queue. Otherwise we have a new owner. */
3337 vdev->queue->owner = p->count ? file->private_data : NULL;
3340 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3342 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3343 struct v4l2_create_buffers *p)
3345 struct video_device *vdev = video_devdata(file);
3346 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3348 p->index = vdev->queue->num_buffers;
3349 /* If count == 0, then just check if memory and type are valid.
3350 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3352 return res != -EBUSY ? res : 0;
3355 if (vb2_queue_is_busy(vdev, file))
3357 res = __create_bufs(vdev->queue, p);
3359 vdev->queue->owner = file->private_data;
3362 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3364 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3365 struct v4l2_buffer *p)
3367 struct video_device *vdev = video_devdata(file);
3369 if (vb2_queue_is_busy(vdev, file))
3371 return vb2_prepare_buf(vdev->queue, p);
3373 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3375 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3377 struct video_device *vdev = video_devdata(file);
3379 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3380 return vb2_querybuf(vdev->queue, p);
3382 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3384 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3386 struct video_device *vdev = video_devdata(file);
3388 if (vb2_queue_is_busy(vdev, file))
3390 return vb2_qbuf(vdev->queue, p);
3392 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3394 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3396 struct video_device *vdev = video_devdata(file);
3398 if (vb2_queue_is_busy(vdev, file))
3400 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3402 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3404 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3406 struct video_device *vdev = video_devdata(file);
3408 if (vb2_queue_is_busy(vdev, file))
3410 return vb2_streamon(vdev->queue, i);
3412 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3414 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3416 struct video_device *vdev = video_devdata(file);
3418 if (vb2_queue_is_busy(vdev, file))
3420 return vb2_streamoff(vdev->queue, i);
3422 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3424 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3426 struct video_device *vdev = video_devdata(file);
3428 if (vb2_queue_is_busy(vdev, file))
3430 return vb2_expbuf(vdev->queue, p);
3432 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3434 /* v4l2_file_operations helpers */
3436 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3438 struct video_device *vdev = video_devdata(file);
3440 return vb2_mmap(vdev->queue, vma);
3442 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3444 int _vb2_fop_release(struct file *file, struct mutex *lock)
3446 struct video_device *vdev = video_devdata(file);
3450 if (file->private_data == vdev->queue->owner) {
3451 vb2_queue_release(vdev->queue);
3452 vdev->queue->owner = NULL;
3456 return v4l2_fh_release(file);
3458 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3460 int vb2_fop_release(struct file *file)
3462 struct video_device *vdev = video_devdata(file);
3463 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3465 return _vb2_fop_release(file, lock);
3467 EXPORT_SYMBOL_GPL(vb2_fop_release);
3469 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3470 size_t count, loff_t *ppos)
3472 struct video_device *vdev = video_devdata(file);
3473 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3476 if (!(vdev->queue->io_modes & VB2_WRITE))
3478 if (lock && mutex_lock_interruptible(lock))
3479 return -ERESTARTSYS;
3480 if (vb2_queue_is_busy(vdev, file))
3482 err = vb2_write(vdev->queue, buf, count, ppos,
3483 file->f_flags & O_NONBLOCK);
3484 if (vdev->queue->fileio)
3485 vdev->queue->owner = file->private_data;
3491 EXPORT_SYMBOL_GPL(vb2_fop_write);
3493 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3494 size_t count, loff_t *ppos)
3496 struct video_device *vdev = video_devdata(file);
3497 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3500 if (!(vdev->queue->io_modes & VB2_READ))
3502 if (lock && mutex_lock_interruptible(lock))
3503 return -ERESTARTSYS;
3504 if (vb2_queue_is_busy(vdev, file))
3506 err = vb2_read(vdev->queue, buf, count, ppos,
3507 file->f_flags & O_NONBLOCK);
3508 if (vdev->queue->fileio)
3509 vdev->queue->owner = file->private_data;
3515 EXPORT_SYMBOL_GPL(vb2_fop_read);
3517 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3519 struct video_device *vdev = video_devdata(file);
3520 struct vb2_queue *q = vdev->queue;
3521 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3526 * If this helper doesn't know how to lock, then you shouldn't be using
3527 * it but you should write your own.
3531 if (lock && mutex_lock_interruptible(lock))
3536 res = vb2_poll(vdev->queue, file, wait);
3538 /* If fileio was started, then we have a new queue owner. */
3539 if (!fileio && q->fileio)
3540 q->owner = file->private_data;
3545 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3548 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3549 unsigned long len, unsigned long pgoff, unsigned long flags)
3551 struct video_device *vdev = video_devdata(file);
3553 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3555 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3558 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3560 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3562 mutex_unlock(vq->lock);
3564 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3566 void vb2_ops_wait_finish(struct vb2_queue *vq)
3568 mutex_lock(vq->lock);
3570 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3572 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3573 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3574 MODULE_LICENSE("GPL");