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);
187 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
189 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
191 struct vb2_queue *q = vb->vb2_queue;
192 enum dma_data_direction dma_dir =
193 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
198 * Allocate memory for all planes in this buffer
199 * NOTE: mmapped areas should be page aligned
201 for (plane = 0; plane < vb->num_planes; ++plane) {
202 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
204 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
205 size, dma_dir, q->gfp_flags);
206 if (IS_ERR_OR_NULL(mem_priv))
209 /* Associate allocator private data with this plane */
210 vb->planes[plane].mem_priv = mem_priv;
211 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
216 /* Free already allocated memory if one of the allocations failed */
217 for (; plane > 0; --plane) {
218 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
219 vb->planes[plane - 1].mem_priv = NULL;
226 * __vb2_buf_mem_free() - free memory of the given buffer
228 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
232 for (plane = 0; plane < vb->num_planes; ++plane) {
233 call_void_memop(vb, put, vb->planes[plane].mem_priv);
234 vb->planes[plane].mem_priv = NULL;
235 dprintk(3, "freed plane %d of buffer %d\n", plane,
241 * __vb2_buf_userptr_put() - release userspace memory associated with
244 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
248 for (plane = 0; plane < vb->num_planes; ++plane) {
249 if (vb->planes[plane].mem_priv)
250 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
251 vb->planes[plane].mem_priv = NULL;
256 * __vb2_plane_dmabuf_put() - release memory associated with
257 * a DMABUF shared plane
259 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
265 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
267 call_void_memop(vb, detach_dmabuf, p->mem_priv);
268 dma_buf_put(p->dbuf);
269 memset(p, 0, sizeof(*p));
273 * __vb2_buf_dmabuf_put() - release memory associated with
274 * a DMABUF shared buffer
276 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
280 for (plane = 0; plane < vb->num_planes; ++plane)
281 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
285 * __setup_lengths() - setup initial lengths for every plane in
286 * every buffer on the queue
288 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
290 unsigned int buffer, plane;
291 struct vb2_buffer *vb;
293 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
294 vb = q->bufs[buffer];
298 for (plane = 0; plane < vb->num_planes; ++plane)
299 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
304 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
305 * every buffer on the queue
307 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
309 unsigned int buffer, plane;
310 struct vb2_buffer *vb;
313 if (q->num_buffers) {
314 struct v4l2_plane *p;
315 vb = q->bufs[q->num_buffers - 1];
316 p = &vb->v4l2_planes[vb->num_planes - 1];
317 off = PAGE_ALIGN(p->m.mem_offset + p->length);
322 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
323 vb = q->bufs[buffer];
327 for (plane = 0; plane < vb->num_planes; ++plane) {
328 vb->v4l2_planes[plane].m.mem_offset = off;
330 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
333 off += vb->v4l2_planes[plane].length;
334 off = PAGE_ALIGN(off);
340 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
341 * video buffer memory for all buffers/planes on the queue and initializes the
344 * Returns the number of buffers successfully allocated.
346 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
347 unsigned int num_buffers, unsigned int num_planes)
350 struct vb2_buffer *vb;
353 for (buffer = 0; buffer < num_buffers; ++buffer) {
354 /* Allocate videobuf buffer structures */
355 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
357 dprintk(1, "memory alloc for buffer struct failed\n");
361 /* Length stores number of planes for multiplanar buffers */
362 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
363 vb->v4l2_buf.length = num_planes;
365 vb->state = VB2_BUF_STATE_DEQUEUED;
367 vb->num_planes = num_planes;
368 vb->v4l2_buf.index = q->num_buffers + buffer;
369 vb->v4l2_buf.type = q->type;
370 vb->v4l2_buf.memory = memory;
372 /* Allocate video buffer memory for the MMAP type */
373 if (memory == V4L2_MEMORY_MMAP) {
374 ret = __vb2_buf_mem_alloc(vb);
376 dprintk(1, "failed allocating memory for "
377 "buffer %d\n", buffer);
382 * Call the driver-provided buffer initialization
383 * callback, if given. An error in initialization
384 * results in queue setup failure.
386 ret = call_vb_qop(vb, buf_init, vb);
388 dprintk(1, "buffer %d %p initialization"
389 " failed\n", buffer, vb);
390 __vb2_buf_mem_free(vb);
396 q->bufs[q->num_buffers + buffer] = vb;
399 __setup_lengths(q, buffer);
400 if (memory == V4L2_MEMORY_MMAP)
401 __setup_offsets(q, buffer);
403 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
410 * __vb2_free_mem() - release all video buffer memory for a given queue
412 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
415 struct vb2_buffer *vb;
417 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
419 vb = q->bufs[buffer];
423 /* Free MMAP buffers or release USERPTR buffers */
424 if (q->memory == V4L2_MEMORY_MMAP)
425 __vb2_buf_mem_free(vb);
426 else if (q->memory == V4L2_MEMORY_DMABUF)
427 __vb2_buf_dmabuf_put(vb);
429 __vb2_buf_userptr_put(vb);
434 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
435 * related information, if no buffers are left return the queue to an
436 * uninitialized state. Might be called even if the queue has already been freed.
438 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
443 * Sanity check: when preparing a buffer the queue lock is released for
444 * a short while (see __buf_prepare for the details), which would allow
445 * a race with a reqbufs which can call this function. Removing the
446 * buffers from underneath __buf_prepare is obviously a bad idea, so we
447 * check if any of the buffers is in the state PREPARING, and if so we
448 * just return -EAGAIN.
450 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
452 if (q->bufs[buffer] == NULL)
454 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
455 dprintk(1, "preparing buffers, cannot free\n");
460 /* Call driver-provided cleanup function for each buffer, if provided */
461 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
463 struct vb2_buffer *vb = q->bufs[buffer];
465 if (vb && vb->planes[0].mem_priv)
466 call_void_vb_qop(vb, buf_cleanup, vb);
469 /* Release video buffer memory */
470 __vb2_free_mem(q, buffers);
472 #ifdef CONFIG_VIDEO_ADV_DEBUG
474 * Check that all the calls were balances during the life-time of this
475 * queue. If not (or if the debug level is 1 or up), then dump the
476 * counters to the kernel log.
478 if (q->num_buffers) {
479 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
480 q->cnt_wait_prepare != q->cnt_wait_finish;
482 if (unbalanced || debug) {
483 pr_info("vb2: counters for queue %p:%s\n", q,
484 unbalanced ? " UNBALANCED!" : "");
485 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
486 q->cnt_queue_setup, q->cnt_start_streaming,
487 q->cnt_stop_streaming);
488 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
489 q->cnt_wait_prepare, q->cnt_wait_finish);
491 q->cnt_queue_setup = 0;
492 q->cnt_wait_prepare = 0;
493 q->cnt_wait_finish = 0;
494 q->cnt_start_streaming = 0;
495 q->cnt_stop_streaming = 0;
497 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
498 struct vb2_buffer *vb = q->bufs[buffer];
499 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
500 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
501 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
502 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
503 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
504 vb->cnt_buf_queue != vb->cnt_buf_done ||
505 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
506 vb->cnt_buf_init != vb->cnt_buf_cleanup;
508 if (unbalanced || debug) {
509 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
510 q, buffer, unbalanced ? " UNBALANCED!" : "");
511 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
512 vb->cnt_buf_init, vb->cnt_buf_cleanup,
513 vb->cnt_buf_prepare, vb->cnt_buf_finish);
514 pr_info("vb2: buf_queue: %u buf_done: %u\n",
515 vb->cnt_buf_queue, vb->cnt_buf_done);
516 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
517 vb->cnt_mem_alloc, vb->cnt_mem_put,
518 vb->cnt_mem_prepare, vb->cnt_mem_finish,
520 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
521 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
522 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
523 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
524 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
525 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
526 vb->cnt_mem_get_dmabuf,
527 vb->cnt_mem_num_users,
534 /* Free videobuf buffers */
535 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
537 kfree(q->bufs[buffer]);
538 q->bufs[buffer] = NULL;
541 q->num_buffers -= buffers;
542 if (!q->num_buffers) {
544 INIT_LIST_HEAD(&q->queued_list);
550 * __verify_planes_array() - verify that the planes array passed in struct
551 * v4l2_buffer from userspace can be safely used
553 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
555 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
558 /* Is memory for copying plane information present? */
559 if (NULL == b->m.planes) {
560 dprintk(1, "multi-planar buffer passed but "
561 "planes array not provided\n");
565 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
566 dprintk(1, "incorrect planes array length, "
567 "expected %d, got %d\n", vb->num_planes, b->length);
575 * __verify_length() - Verify that the bytesused value for each plane fits in
576 * the plane length and that the data offset doesn't exceed the bytesused value.
578 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
581 unsigned int bytesused;
584 if (!V4L2_TYPE_IS_OUTPUT(b->type))
587 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
588 for (plane = 0; plane < vb->num_planes; ++plane) {
589 length = (b->memory == V4L2_MEMORY_USERPTR ||
590 b->memory == V4L2_MEMORY_DMABUF)
591 ? b->m.planes[plane].length
592 : vb->v4l2_planes[plane].length;
593 bytesused = b->m.planes[plane].bytesused
594 ? b->m.planes[plane].bytesused : length;
596 if (b->m.planes[plane].bytesused > length)
599 if (b->m.planes[plane].data_offset > 0 &&
600 b->m.planes[plane].data_offset >= bytesused)
604 length = (b->memory == V4L2_MEMORY_USERPTR)
605 ? b->length : vb->v4l2_planes[0].length;
606 bytesused = b->bytesused ? b->bytesused : length;
608 if (b->bytesused > length)
616 * __buffer_in_use() - return true if the buffer is in use and
617 * the queue cannot be freed (by the means of REQBUFS(0)) call
619 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
622 for (plane = 0; plane < vb->num_planes; ++plane) {
623 void *mem_priv = vb->planes[plane].mem_priv;
625 * If num_users() has not been provided, call_memop
626 * will return 0, apparently nobody cares about this
627 * case anyway. If num_users() returns more than 1,
628 * we are not the only user of the plane's memory.
630 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
637 * __buffers_in_use() - return true if any buffers on the queue are in use and
638 * the queue cannot be freed (by the means of REQBUFS(0)) call
640 static bool __buffers_in_use(struct vb2_queue *q)
643 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
644 if (__buffer_in_use(q, q->bufs[buffer]))
651 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
652 * returned to userspace
654 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
656 struct vb2_queue *q = vb->vb2_queue;
658 /* Copy back data such as timestamp, flags, etc. */
659 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
660 b->reserved2 = vb->v4l2_buf.reserved2;
661 b->reserved = vb->v4l2_buf.reserved;
663 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
665 * Fill in plane-related data if userspace provided an array
666 * for it. The caller has already verified memory and size.
668 b->length = vb->num_planes;
669 memcpy(b->m.planes, vb->v4l2_planes,
670 b->length * sizeof(struct v4l2_plane));
673 * We use length and offset in v4l2_planes array even for
674 * single-planar buffers, but userspace does not.
676 b->length = vb->v4l2_planes[0].length;
677 b->bytesused = vb->v4l2_planes[0].bytesused;
678 if (q->memory == V4L2_MEMORY_MMAP)
679 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
680 else if (q->memory == V4L2_MEMORY_USERPTR)
681 b->m.userptr = vb->v4l2_planes[0].m.userptr;
682 else if (q->memory == V4L2_MEMORY_DMABUF)
683 b->m.fd = vb->v4l2_planes[0].m.fd;
687 * Clear any buffer state related flags.
689 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
690 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
691 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
692 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
694 * For non-COPY timestamps, drop timestamp source bits
695 * and obtain the timestamp source from the queue.
697 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
698 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
702 case VB2_BUF_STATE_QUEUED:
703 case VB2_BUF_STATE_ACTIVE:
704 b->flags |= V4L2_BUF_FLAG_QUEUED;
706 case VB2_BUF_STATE_ERROR:
707 b->flags |= V4L2_BUF_FLAG_ERROR;
709 case VB2_BUF_STATE_DONE:
710 b->flags |= V4L2_BUF_FLAG_DONE;
712 case VB2_BUF_STATE_PREPARED:
713 b->flags |= V4L2_BUF_FLAG_PREPARED;
715 case VB2_BUF_STATE_PREPARING:
716 case VB2_BUF_STATE_DEQUEUED:
721 if (__buffer_in_use(q, vb))
722 b->flags |= V4L2_BUF_FLAG_MAPPED;
726 * vb2_querybuf() - query video buffer information
728 * @b: buffer struct passed from userspace to vidioc_querybuf handler
731 * Should be called from vidioc_querybuf ioctl handler in driver.
732 * This function will verify the passed v4l2_buffer structure and fill the
733 * relevant information for the userspace.
735 * The return values from this function are intended to be directly returned
736 * from vidioc_querybuf handler in driver.
738 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
740 struct vb2_buffer *vb;
743 if (b->type != q->type) {
744 dprintk(1, "wrong buffer type\n");
748 if (b->index >= q->num_buffers) {
749 dprintk(1, "buffer index out of range\n");
752 vb = q->bufs[b->index];
753 ret = __verify_planes_array(vb, b);
755 __fill_v4l2_buffer(vb, b);
758 EXPORT_SYMBOL(vb2_querybuf);
761 * __verify_userptr_ops() - verify that all memory operations required for
762 * USERPTR queue type have been provided
764 static int __verify_userptr_ops(struct vb2_queue *q)
766 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
767 !q->mem_ops->put_userptr)
774 * __verify_mmap_ops() - verify that all memory operations required for
775 * MMAP queue type have been provided
777 static int __verify_mmap_ops(struct vb2_queue *q)
779 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
780 !q->mem_ops->put || !q->mem_ops->mmap)
787 * __verify_dmabuf_ops() - verify that all memory operations required for
788 * DMABUF queue type have been provided
790 static int __verify_dmabuf_ops(struct vb2_queue *q)
792 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
793 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
794 !q->mem_ops->unmap_dmabuf)
801 * __verify_memory_type() - Check whether the memory type and buffer type
802 * passed to a buffer operation are compatible with the queue.
804 static int __verify_memory_type(struct vb2_queue *q,
805 enum v4l2_memory memory, enum v4l2_buf_type type)
807 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
808 memory != V4L2_MEMORY_DMABUF) {
809 dprintk(1, "unsupported memory type\n");
813 if (type != q->type) {
814 dprintk(1, "requested type is incorrect\n");
819 * Make sure all the required memory ops for given memory type
822 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
823 dprintk(1, "MMAP for current setup unsupported\n");
827 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
828 dprintk(1, "USERPTR for current setup unsupported\n");
832 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
833 dprintk(1, "DMABUF for current setup unsupported\n");
838 * Place the busy tests at the end: -EBUSY can be ignored when
839 * create_bufs is called with count == 0, but count == 0 should still
840 * do the memory and type validation.
842 if (vb2_fileio_is_active(q)) {
843 dprintk(1, "file io in progress\n");
850 * __reqbufs() - Initiate streaming
851 * @q: videobuf2 queue
852 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
854 * Should be called from vidioc_reqbufs ioctl handler of a driver.
856 * 1) verifies streaming parameters passed from the userspace,
857 * 2) sets up the queue,
858 * 3) negotiates number of buffers and planes per buffer with the driver
859 * to be used during streaming,
860 * 4) allocates internal buffer structures (struct vb2_buffer), according to
861 * the agreed parameters,
862 * 5) for MMAP memory type, allocates actual video memory, using the
863 * memory handling/allocation routines provided during queue initialization
865 * If req->count is 0, all the memory will be freed instead.
866 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
867 * and the queue is not busy, memory will be reallocated.
869 * The return values from this function are intended to be directly returned
870 * from vidioc_reqbufs handler in driver.
872 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
874 unsigned int num_buffers, allocated_buffers, num_planes = 0;
878 dprintk(1, "streaming active\n");
882 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
884 * We already have buffers allocated, so first check if they
885 * are not in use and can be freed.
887 mutex_lock(&q->mmap_lock);
888 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
889 mutex_unlock(&q->mmap_lock);
890 dprintk(1, "memory in use, cannot free\n");
895 * Call queue_cancel to clean up any buffers in the PREPARED or
896 * QUEUED state which is possible if buffers were prepared or
897 * queued without ever calling STREAMON.
899 __vb2_queue_cancel(q);
900 ret = __vb2_queue_free(q, q->num_buffers);
901 mutex_unlock(&q->mmap_lock);
906 * In case of REQBUFS(0) return immediately without calling
907 * driver's queue_setup() callback and allocating resources.
914 * Make sure the requested values and current defaults are sane.
916 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
917 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
918 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
919 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
920 q->memory = req->memory;
923 * Ask the driver how many buffers and planes per buffer it requires.
924 * Driver also sets the size and allocator context for each plane.
926 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
927 q->plane_sizes, q->alloc_ctx);
931 /* Finally, allocate buffers and video memory */
932 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
933 if (allocated_buffers == 0) {
934 dprintk(1, "memory allocation failed\n");
939 * There is no point in continuing if we can't allocate the minimum
940 * number of buffers needed by this vb2_queue.
942 if (allocated_buffers < q->min_buffers_needed)
946 * Check if driver can handle the allocated number of buffers.
948 if (!ret && allocated_buffers < num_buffers) {
949 num_buffers = allocated_buffers;
951 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
952 &num_planes, q->plane_sizes, q->alloc_ctx);
954 if (!ret && allocated_buffers < num_buffers)
958 * Either the driver has accepted a smaller number of buffers,
959 * or .queue_setup() returned an error
963 mutex_lock(&q->mmap_lock);
964 q->num_buffers = allocated_buffers;
968 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
969 * from q->num_buffers.
971 __vb2_queue_free(q, allocated_buffers);
972 mutex_unlock(&q->mmap_lock);
975 mutex_unlock(&q->mmap_lock);
978 * Return the number of successfully allocated buffers
981 req->count = allocated_buffers;
982 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
988 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
990 * @q: videobuf2 queue
991 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
993 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
995 int ret = __verify_memory_type(q, req->memory, req->type);
997 return ret ? ret : __reqbufs(q, req);
999 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1002 * __create_bufs() - Allocate buffers and any required auxiliary structs
1003 * @q: videobuf2 queue
1004 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1007 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1009 * 1) verifies parameter sanity
1010 * 2) calls the .queue_setup() queue operation
1011 * 3) performs any necessary memory allocations
1013 * The return values from this function are intended to be directly returned
1014 * from vidioc_create_bufs handler in driver.
1016 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1018 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1021 if (q->num_buffers == VIDEO_MAX_FRAME) {
1022 dprintk(1, "maximum number of buffers already allocated\n");
1026 if (!q->num_buffers) {
1027 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1028 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1029 q->memory = create->memory;
1030 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1033 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1036 * Ask the driver, whether the requested number of buffers, planes per
1037 * buffer and their sizes are acceptable
1039 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1040 &num_planes, q->plane_sizes, q->alloc_ctx);
1044 /* Finally, allocate buffers and video memory */
1045 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1047 if (allocated_buffers == 0) {
1048 dprintk(1, "memory allocation failed\n");
1053 * Check if driver can handle the so far allocated number of buffers.
1055 if (allocated_buffers < num_buffers) {
1056 num_buffers = allocated_buffers;
1059 * q->num_buffers contains the total number of buffers, that the
1060 * queue driver has set up
1062 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1063 &num_planes, q->plane_sizes, q->alloc_ctx);
1065 if (!ret && allocated_buffers < num_buffers)
1069 * Either the driver has accepted a smaller number of buffers,
1070 * or .queue_setup() returned an error
1074 mutex_lock(&q->mmap_lock);
1075 q->num_buffers += allocated_buffers;
1079 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1080 * from q->num_buffers.
1082 __vb2_queue_free(q, allocated_buffers);
1083 mutex_unlock(&q->mmap_lock);
1086 mutex_unlock(&q->mmap_lock);
1089 * Return the number of successfully allocated buffers
1092 create->count = allocated_buffers;
1098 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1099 * memory and type values.
1100 * @q: videobuf2 queue
1101 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1104 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1106 int ret = __verify_memory_type(q, create->memory, create->format.type);
1108 create->index = q->num_buffers;
1109 if (create->count == 0)
1110 return ret != -EBUSY ? ret : 0;
1111 return ret ? ret : __create_bufs(q, create);
1113 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1116 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1117 * @vb: vb2_buffer to which the plane in question belongs to
1118 * @plane_no: plane number for which the address is to be returned
1120 * This function returns a kernel virtual address of a given plane if
1121 * such a mapping exist, NULL otherwise.
1123 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1125 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1128 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1131 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1134 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1135 * @vb: vb2_buffer to which the plane in question belongs to
1136 * @plane_no: plane number for which the cookie is to be returned
1138 * This function returns an allocator specific cookie for a given plane if
1139 * available, NULL otherwise. The allocator should provide some simple static
1140 * inline function, which would convert this cookie to the allocator specific
1141 * type that can be used directly by the driver to access the buffer. This can
1142 * be for example physical address, pointer to scatter list or IOMMU mapping.
1144 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1146 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1149 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1151 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1154 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1155 * @vb: vb2_buffer returned from the driver
1156 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1157 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1158 * If start_streaming fails then it should return buffers with state
1159 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1161 * This function should be called by the driver after a hardware operation on
1162 * a buffer is finished and the buffer may be returned to userspace. The driver
1163 * cannot use this buffer anymore until it is queued back to it by videobuf
1164 * by the means of buf_queue callback. Only buffers previously queued to the
1165 * driver by buf_queue can be passed to this function.
1167 * While streaming a buffer can only be returned in state DONE or ERROR.
1168 * The start_streaming op can also return them in case the DMA engine cannot
1169 * be started for some reason. In that case the buffers should be returned with
1172 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1174 struct vb2_queue *q = vb->vb2_queue;
1175 unsigned long flags;
1178 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1181 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1182 state != VB2_BUF_STATE_ERROR &&
1183 state != VB2_BUF_STATE_QUEUED))
1184 state = VB2_BUF_STATE_ERROR;
1186 #ifdef CONFIG_VIDEO_ADV_DEBUG
1188 * Although this is not a callback, it still does have to balance
1189 * with the buf_queue op. So update this counter manually.
1193 dprintk(4, "done processing on buffer %d, state: %d\n",
1194 vb->v4l2_buf.index, state);
1197 for (plane = 0; plane < vb->num_planes; ++plane)
1198 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1200 /* Add the buffer to the done buffers list */
1201 spin_lock_irqsave(&q->done_lock, flags);
1203 if (state != VB2_BUF_STATE_QUEUED)
1204 list_add_tail(&vb->done_entry, &q->done_list);
1205 atomic_dec(&q->owned_by_drv_count);
1206 spin_unlock_irqrestore(&q->done_lock, flags);
1208 if (state == VB2_BUF_STATE_QUEUED)
1211 /* Inform any processes that may be waiting for buffers */
1212 wake_up(&q->done_wq);
1214 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1217 * vb2_discard_done() - discard all buffers marked as DONE
1218 * @q: videobuf2 queue
1220 * This function is intended to be used with suspend/resume operations. It
1221 * discards all 'done' buffers as they would be too old to be requested after
1224 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1225 * delayed works before calling this function to make sure no buffer will be
1226 * touched by the driver and/or hardware.
1228 void vb2_discard_done(struct vb2_queue *q)
1230 struct vb2_buffer *vb;
1231 unsigned long flags;
1233 spin_lock_irqsave(&q->done_lock, flags);
1234 list_for_each_entry(vb, &q->done_list, done_entry)
1235 vb->state = VB2_BUF_STATE_ERROR;
1236 spin_unlock_irqrestore(&q->done_lock, flags);
1238 EXPORT_SYMBOL_GPL(vb2_discard_done);
1241 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1242 * v4l2_buffer by the userspace. The caller has already verified that struct
1243 * v4l2_buffer has a valid number of planes.
1245 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1246 struct v4l2_plane *v4l2_planes)
1250 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1251 if (b->memory == V4L2_MEMORY_USERPTR) {
1252 for (plane = 0; plane < vb->num_planes; ++plane) {
1253 v4l2_planes[plane].m.userptr =
1254 b->m.planes[plane].m.userptr;
1255 v4l2_planes[plane].length =
1256 b->m.planes[plane].length;
1259 if (b->memory == V4L2_MEMORY_DMABUF) {
1260 for (plane = 0; plane < vb->num_planes; ++plane) {
1261 v4l2_planes[plane].m.fd =
1262 b->m.planes[plane].m.fd;
1263 v4l2_planes[plane].length =
1264 b->m.planes[plane].length;
1268 /* Fill in driver-provided information for OUTPUT types */
1269 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1271 * Will have to go up to b->length when API starts
1272 * accepting variable number of planes.
1274 * If bytesused == 0 for the output buffer, then fall
1275 * back to the full buffer size. In that case
1276 * userspace clearly never bothered to set it and
1277 * it's a safe assumption that they really meant to
1278 * use the full plane sizes.
1280 for (plane = 0; plane < vb->num_planes; ++plane) {
1281 struct v4l2_plane *pdst = &v4l2_planes[plane];
1282 struct v4l2_plane *psrc = &b->m.planes[plane];
1284 pdst->bytesused = psrc->bytesused ?
1285 psrc->bytesused : pdst->length;
1286 pdst->data_offset = psrc->data_offset;
1291 * Single-planar buffers do not use planes array,
1292 * so fill in relevant v4l2_buffer struct fields instead.
1293 * In videobuf we use our internal V4l2_planes struct for
1294 * single-planar buffers as well, for simplicity.
1296 * If bytesused == 0 for the output buffer, then fall back
1297 * to the full buffer size as that's a sensible default.
1299 if (b->memory == V4L2_MEMORY_USERPTR) {
1300 v4l2_planes[0].m.userptr = b->m.userptr;
1301 v4l2_planes[0].length = b->length;
1304 if (b->memory == V4L2_MEMORY_DMABUF) {
1305 v4l2_planes[0].m.fd = b->m.fd;
1306 v4l2_planes[0].length = b->length;
1309 if (V4L2_TYPE_IS_OUTPUT(b->type))
1310 v4l2_planes[0].bytesused = b->bytesused ?
1311 b->bytesused : v4l2_planes[0].length;
1313 v4l2_planes[0].bytesused = 0;
1317 /* Zero flags that the vb2 core handles */
1318 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1319 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1320 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1322 * Non-COPY timestamps and non-OUTPUT queues will get
1323 * their timestamp and timestamp source flags from the
1326 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1329 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1331 * For output buffers mask out the timecode flag:
1332 * this will be handled later in vb2_internal_qbuf().
1333 * The 'field' is valid metadata for this output buffer
1334 * and so that needs to be copied here.
1336 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1337 vb->v4l2_buf.field = b->field;
1339 /* Zero any output buffer flags as this is a capture buffer */
1340 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1345 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1347 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1349 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1350 return call_vb_qop(vb, buf_prepare, vb);
1354 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1356 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1358 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1359 struct vb2_queue *q = vb->vb2_queue;
1363 enum dma_data_direction dma_dir =
1364 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1365 bool reacquired = vb->planes[0].mem_priv == NULL;
1367 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1368 /* Copy relevant information provided by the userspace */
1369 __fill_vb2_buffer(vb, b, planes);
1371 for (plane = 0; plane < vb->num_planes; ++plane) {
1372 /* Skip the plane if already verified */
1373 if (vb->v4l2_planes[plane].m.userptr &&
1374 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1375 && vb->v4l2_planes[plane].length == planes[plane].length)
1378 dprintk(3, "userspace address for plane %d changed, "
1379 "reacquiring memory\n", plane);
1381 /* Check if the provided plane buffer is large enough */
1382 if (planes[plane].length < q->plane_sizes[plane]) {
1383 dprintk(1, "provided buffer size %u is less than "
1384 "setup size %u for plane %d\n",
1385 planes[plane].length,
1386 q->plane_sizes[plane], plane);
1391 /* Release previously acquired memory if present */
1392 if (vb->planes[plane].mem_priv) {
1395 call_void_vb_qop(vb, buf_cleanup, vb);
1397 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1400 vb->planes[plane].mem_priv = NULL;
1401 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1403 /* Acquire each plane's memory */
1404 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1405 planes[plane].m.userptr,
1406 planes[plane].length, dma_dir);
1407 if (IS_ERR_OR_NULL(mem_priv)) {
1408 dprintk(1, "failed acquiring userspace "
1409 "memory for plane %d\n", plane);
1410 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1413 vb->planes[plane].mem_priv = mem_priv;
1417 * Now that everything is in order, copy relevant information
1418 * provided by userspace.
1420 for (plane = 0; plane < vb->num_planes; ++plane)
1421 vb->v4l2_planes[plane] = planes[plane];
1425 * One or more planes changed, so we must call buf_init to do
1426 * the driver-specific initialization on the newly acquired
1427 * buffer, if provided.
1429 ret = call_vb_qop(vb, buf_init, vb);
1431 dprintk(1, "buffer initialization failed\n");
1436 ret = call_vb_qop(vb, buf_prepare, vb);
1438 dprintk(1, "buffer preparation failed\n");
1439 call_void_vb_qop(vb, buf_cleanup, vb);
1445 /* In case of errors, release planes that were already acquired */
1446 for (plane = 0; plane < vb->num_planes; ++plane) {
1447 if (vb->planes[plane].mem_priv)
1448 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1449 vb->planes[plane].mem_priv = NULL;
1450 vb->v4l2_planes[plane].m.userptr = 0;
1451 vb->v4l2_planes[plane].length = 0;
1458 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1460 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1462 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1463 struct vb2_queue *q = vb->vb2_queue;
1467 enum dma_data_direction dma_dir =
1468 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1469 bool reacquired = vb->planes[0].mem_priv == NULL;
1471 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1472 /* Copy relevant information provided by the userspace */
1473 __fill_vb2_buffer(vb, b, planes);
1475 for (plane = 0; plane < vb->num_planes; ++plane) {
1476 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1478 if (IS_ERR_OR_NULL(dbuf)) {
1479 dprintk(1, "invalid dmabuf fd for plane %d\n",
1485 /* use DMABUF size if length is not provided */
1486 if (planes[plane].length == 0)
1487 planes[plane].length = dbuf->size;
1489 if (planes[plane].length < q->plane_sizes[plane]) {
1490 dprintk(1, "invalid dmabuf length for plane %d\n",
1496 /* Skip the plane if already verified */
1497 if (dbuf == vb->planes[plane].dbuf &&
1498 vb->v4l2_planes[plane].length == planes[plane].length) {
1503 dprintk(1, "buffer for plane %d changed\n", plane);
1507 call_void_vb_qop(vb, buf_cleanup, vb);
1510 /* Release previously acquired memory if present */
1511 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1512 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1514 /* Acquire each plane's memory */
1515 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1516 dbuf, planes[plane].length, dma_dir);
1517 if (IS_ERR(mem_priv)) {
1518 dprintk(1, "failed to attach dmabuf\n");
1519 ret = PTR_ERR(mem_priv);
1524 vb->planes[plane].dbuf = dbuf;
1525 vb->planes[plane].mem_priv = mem_priv;
1528 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1529 * really we want to do this just before the DMA, not while queueing
1532 for (plane = 0; plane < vb->num_planes; ++plane) {
1533 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1535 dprintk(1, "failed to map dmabuf for plane %d\n",
1539 vb->planes[plane].dbuf_mapped = 1;
1543 * Now that everything is in order, copy relevant information
1544 * provided by userspace.
1546 for (plane = 0; plane < vb->num_planes; ++plane)
1547 vb->v4l2_planes[plane] = planes[plane];
1551 * Call driver-specific initialization on the newly acquired buffer,
1554 ret = call_vb_qop(vb, buf_init, vb);
1556 dprintk(1, "buffer initialization failed\n");
1561 ret = call_vb_qop(vb, buf_prepare, vb);
1563 dprintk(1, "buffer preparation failed\n");
1564 call_void_vb_qop(vb, buf_cleanup, vb);
1570 /* In case of errors, release planes that were already acquired */
1571 __vb2_buf_dmabuf_put(vb);
1577 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1579 static void __enqueue_in_driver(struct vb2_buffer *vb)
1581 struct vb2_queue *q = vb->vb2_queue;
1584 vb->state = VB2_BUF_STATE_ACTIVE;
1585 atomic_inc(&q->owned_by_drv_count);
1588 for (plane = 0; plane < vb->num_planes; ++plane)
1589 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1591 call_void_vb_qop(vb, buf_queue, vb);
1594 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1596 struct vb2_queue *q = vb->vb2_queue;
1599 ret = __verify_length(vb, b);
1601 dprintk(1, "plane parameters verification failed: %d\n", ret);
1604 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1606 * If the format's field is ALTERNATE, then the buffer's field
1607 * should be either TOP or BOTTOM, not ALTERNATE since that
1608 * makes no sense. The driver has to know whether the
1609 * buffer represents a top or a bottom field in order to
1610 * program any DMA correctly. Using ALTERNATE is wrong, since
1611 * that just says that it is either a top or a bottom field,
1612 * but not which of the two it is.
1614 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1619 dprintk(1, "fatal error occurred on queue\n");
1623 vb->state = VB2_BUF_STATE_PREPARING;
1624 vb->v4l2_buf.timestamp.tv_sec = 0;
1625 vb->v4l2_buf.timestamp.tv_usec = 0;
1626 vb->v4l2_buf.sequence = 0;
1628 switch (q->memory) {
1629 case V4L2_MEMORY_MMAP:
1630 ret = __qbuf_mmap(vb, b);
1632 case V4L2_MEMORY_USERPTR:
1633 down_read(¤t->mm->mmap_sem);
1634 ret = __qbuf_userptr(vb, b);
1635 up_read(¤t->mm->mmap_sem);
1637 case V4L2_MEMORY_DMABUF:
1638 ret = __qbuf_dmabuf(vb, b);
1641 WARN(1, "Invalid queue type\n");
1646 dprintk(1, "buffer preparation failed: %d\n", ret);
1647 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1652 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1655 if (b->type != q->type) {
1656 dprintk(1, "%s: invalid buffer type\n", opname);
1660 if (b->index >= q->num_buffers) {
1661 dprintk(1, "%s: buffer index out of range\n", opname);
1665 if (q->bufs[b->index] == NULL) {
1666 /* Should never happen */
1667 dprintk(1, "%s: buffer is NULL\n", opname);
1671 if (b->memory != q->memory) {
1672 dprintk(1, "%s: invalid memory type\n", opname);
1676 return __verify_planes_array(q->bufs[b->index], b);
1680 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1681 * @q: videobuf2 queue
1682 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1685 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1687 * 1) verifies the passed buffer,
1688 * 2) calls buf_prepare callback in the driver (if provided), in which
1689 * driver-specific buffer initialization can be performed,
1691 * The return values from this function are intended to be directly returned
1692 * from vidioc_prepare_buf handler in driver.
1694 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1696 struct vb2_buffer *vb;
1699 if (vb2_fileio_is_active(q)) {
1700 dprintk(1, "file io in progress\n");
1704 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1708 vb = q->bufs[b->index];
1709 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1710 dprintk(1, "invalid buffer state %d\n",
1715 ret = __buf_prepare(vb, b);
1717 /* Fill buffer information for the userspace */
1718 __fill_v4l2_buffer(vb, b);
1720 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1724 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1727 * vb2_start_streaming() - Attempt to start streaming.
1728 * @q: videobuf2 queue
1730 * Attempt to start streaming. When this function is called there must be
1731 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1732 * number of buffers required for the DMA engine to function). If the
1733 * @start_streaming op fails it is supposed to return all the driver-owned
1734 * buffers back to vb2 in state QUEUED. Check if that happened and if
1735 * not warn and reclaim them forcefully.
1737 static int vb2_start_streaming(struct vb2_queue *q)
1739 struct vb2_buffer *vb;
1743 * If any buffers were queued before streamon,
1744 * we can now pass them to driver for processing.
1746 list_for_each_entry(vb, &q->queued_list, queued_entry)
1747 __enqueue_in_driver(vb);
1749 /* Tell the driver to start streaming */
1750 q->start_streaming_called = 1;
1751 ret = call_qop(q, start_streaming, q,
1752 atomic_read(&q->owned_by_drv_count));
1756 q->start_streaming_called = 0;
1758 dprintk(1, "driver refused to start streaming\n");
1760 * If you see this warning, then the driver isn't cleaning up properly
1761 * after a failed start_streaming(). See the start_streaming()
1762 * documentation in videobuf2-core.h for more information how buffers
1763 * should be returned to vb2 in start_streaming().
1765 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1769 * Forcefully reclaim buffers if the driver did not
1770 * correctly return them to vb2.
1772 for (i = 0; i < q->num_buffers; ++i) {
1774 if (vb->state == VB2_BUF_STATE_ACTIVE)
1775 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1777 /* Must be zero now */
1778 WARN_ON(atomic_read(&q->owned_by_drv_count));
1781 * If done_list is not empty, then start_streaming() didn't call
1782 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1785 WARN_ON(!list_empty(&q->done_list));
1789 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1791 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1792 struct vb2_buffer *vb;
1797 vb = q->bufs[b->index];
1799 switch (vb->state) {
1800 case VB2_BUF_STATE_DEQUEUED:
1801 ret = __buf_prepare(vb, b);
1805 case VB2_BUF_STATE_PREPARED:
1807 case VB2_BUF_STATE_PREPARING:
1808 dprintk(1, "buffer still being prepared\n");
1811 dprintk(1, "invalid buffer state %d\n", vb->state);
1816 * Add to the queued buffers list, a buffer will stay on it until
1817 * dequeued in dqbuf.
1819 list_add_tail(&vb->queued_entry, &q->queued_list);
1821 q->waiting_for_buffers = false;
1822 vb->state = VB2_BUF_STATE_QUEUED;
1823 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1825 * For output buffers copy the timestamp if needed,
1826 * and the timecode field and flag if needed.
1828 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1829 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1830 vb->v4l2_buf.timestamp = b->timestamp;
1831 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1832 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1833 vb->v4l2_buf.timecode = b->timecode;
1837 * If already streaming, give the buffer to driver for processing.
1838 * If not, the buffer will be given to driver on next streamon.
1840 if (q->start_streaming_called)
1841 __enqueue_in_driver(vb);
1843 /* Fill buffer information for the userspace */
1844 __fill_v4l2_buffer(vb, b);
1847 * If streamon has been called, and we haven't yet called
1848 * start_streaming() since not enough buffers were queued, and
1849 * we now have reached the minimum number of queued buffers,
1850 * then we can finally call start_streaming().
1852 if (q->streaming && !q->start_streaming_called &&
1853 q->queued_count >= q->min_buffers_needed) {
1854 ret = vb2_start_streaming(q);
1859 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1864 * vb2_qbuf() - Queue a buffer from userspace
1865 * @q: videobuf2 queue
1866 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1869 * Should be called from vidioc_qbuf ioctl handler of a driver.
1871 * 1) verifies the passed buffer,
1872 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1873 * which driver-specific buffer initialization can be performed,
1874 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1875 * callback for processing.
1877 * The return values from this function are intended to be directly returned
1878 * from vidioc_qbuf handler in driver.
1880 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1882 if (vb2_fileio_is_active(q)) {
1883 dprintk(1, "file io in progress\n");
1887 return vb2_internal_qbuf(q, b);
1889 EXPORT_SYMBOL_GPL(vb2_qbuf);
1892 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1895 * Will sleep if required for nonblocking == false.
1897 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1900 * All operations on vb_done_list are performed under done_lock
1901 * spinlock protection. However, buffers may be removed from
1902 * it and returned to userspace only while holding both driver's
1903 * lock and the done_lock spinlock. Thus we can be sure that as
1904 * long as we hold the driver's lock, the list will remain not
1905 * empty if list_empty() check succeeds.
1911 if (!q->streaming) {
1912 dprintk(1, "streaming off, will not wait for buffers\n");
1917 dprintk(1, "Queue in error state, will not wait for buffers\n");
1921 if (!list_empty(&q->done_list)) {
1923 * Found a buffer that we were waiting for.
1929 dprintk(1, "nonblocking and no buffers to dequeue, "
1935 * We are streaming and blocking, wait for another buffer to
1936 * become ready or for streamoff. Driver's lock is released to
1937 * allow streamoff or qbuf to be called while waiting.
1939 call_void_qop(q, wait_prepare, q);
1942 * All locks have been released, it is safe to sleep now.
1944 dprintk(3, "will sleep waiting for buffers\n");
1945 ret = wait_event_interruptible(q->done_wq,
1946 !list_empty(&q->done_list) || !q->streaming ||
1950 * We need to reevaluate both conditions again after reacquiring
1951 * the locks or return an error if one occurred.
1953 call_void_qop(q, wait_finish, q);
1955 dprintk(1, "sleep was interrupted\n");
1963 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1965 * Will sleep if required for nonblocking == false.
1967 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1968 struct v4l2_buffer *b, int nonblocking)
1970 unsigned long flags;
1974 * Wait for at least one buffer to become available on the done_list.
1976 ret = __vb2_wait_for_done_vb(q, nonblocking);
1981 * Driver's lock has been held since we last verified that done_list
1982 * is not empty, so no need for another list_empty(done_list) check.
1984 spin_lock_irqsave(&q->done_lock, flags);
1985 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1987 * Only remove the buffer from done_list if v4l2_buffer can handle all
1990 ret = __verify_planes_array(*vb, b);
1992 list_del(&(*vb)->done_entry);
1993 spin_unlock_irqrestore(&q->done_lock, flags);
1999 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2000 * @q: videobuf2 queue
2002 * This function will wait until all buffers that have been given to the driver
2003 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2004 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2005 * taken, for example from stop_streaming() callback.
2007 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2009 if (!q->streaming) {
2010 dprintk(1, "streaming off, will not wait for buffers\n");
2014 if (q->start_streaming_called)
2015 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2018 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2021 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2023 static void __vb2_dqbuf(struct vb2_buffer *vb)
2025 struct vb2_queue *q = vb->vb2_queue;
2028 /* nothing to do if the buffer is already dequeued */
2029 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2032 vb->state = VB2_BUF_STATE_DEQUEUED;
2034 /* unmap DMABUF buffer */
2035 if (q->memory == V4L2_MEMORY_DMABUF)
2036 for (i = 0; i < vb->num_planes; ++i) {
2037 if (!vb->planes[i].dbuf_mapped)
2039 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2040 vb->planes[i].dbuf_mapped = 0;
2044 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2046 struct vb2_buffer *vb = NULL;
2049 if (b->type != q->type) {
2050 dprintk(1, "invalid buffer type\n");
2053 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2057 switch (vb->state) {
2058 case VB2_BUF_STATE_DONE:
2059 dprintk(3, "returning done buffer\n");
2061 case VB2_BUF_STATE_ERROR:
2062 dprintk(3, "returning done buffer with errors\n");
2065 dprintk(1, "invalid buffer state\n");
2069 call_void_vb_qop(vb, buf_finish, vb);
2071 /* Fill buffer information for the userspace */
2072 __fill_v4l2_buffer(vb, b);
2073 /* Remove from videobuf queue */
2074 list_del(&vb->queued_entry);
2076 /* go back to dequeued state */
2079 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2080 vb->v4l2_buf.index, vb->state);
2086 * vb2_dqbuf() - Dequeue a buffer to the userspace
2087 * @q: videobuf2 queue
2088 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2090 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2091 * buffers ready for dequeuing are present. Normally the driver
2092 * would be passing (file->f_flags & O_NONBLOCK) here
2094 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2096 * 1) verifies the passed buffer,
2097 * 2) calls buf_finish callback in the driver (if provided), in which
2098 * driver can perform any additional operations that may be required before
2099 * returning the buffer to userspace, such as cache sync,
2100 * 3) the buffer struct members are filled with relevant information for
2103 * The return values from this function are intended to be directly returned
2104 * from vidioc_dqbuf handler in driver.
2106 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2108 if (vb2_fileio_is_active(q)) {
2109 dprintk(1, "file io in progress\n");
2112 return vb2_internal_dqbuf(q, b, nonblocking);
2114 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2117 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2119 * Removes all queued buffers from driver's queue and all buffers queued by
2120 * userspace from videobuf's queue. Returns to state after reqbufs.
2122 static void __vb2_queue_cancel(struct vb2_queue *q)
2127 * Tell driver to stop all transactions and release all queued
2130 if (q->start_streaming_called)
2131 call_void_qop(q, stop_streaming, q);
2134 * If you see this warning, then the driver isn't cleaning up properly
2135 * in stop_streaming(). See the stop_streaming() documentation in
2136 * videobuf2-core.h for more information how buffers should be returned
2137 * to vb2 in stop_streaming().
2139 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2140 for (i = 0; i < q->num_buffers; ++i)
2141 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2142 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2143 /* Must be zero now */
2144 WARN_ON(atomic_read(&q->owned_by_drv_count));
2148 q->start_streaming_called = 0;
2149 q->queued_count = 0;
2153 * Remove all buffers from videobuf's list...
2155 INIT_LIST_HEAD(&q->queued_list);
2157 * ...and done list; userspace will not receive any buffers it
2158 * has not already dequeued before initiating cancel.
2160 INIT_LIST_HEAD(&q->done_list);
2161 atomic_set(&q->owned_by_drv_count, 0);
2162 wake_up_all(&q->done_wq);
2165 * Reinitialize all buffers for next use.
2166 * Make sure to call buf_finish for any queued buffers. Normally
2167 * that's done in dqbuf, but that's not going to happen when we
2168 * cancel the whole queue. Note: this code belongs here, not in
2169 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2170 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2171 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2173 for (i = 0; i < q->num_buffers; ++i) {
2174 struct vb2_buffer *vb = q->bufs[i];
2176 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2177 vb->state = VB2_BUF_STATE_PREPARED;
2178 call_void_vb_qop(vb, buf_finish, vb);
2184 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2188 if (type != q->type) {
2189 dprintk(1, "invalid stream type\n");
2194 dprintk(3, "already streaming\n");
2198 if (!q->num_buffers) {
2199 dprintk(1, "no buffers have been allocated\n");
2203 if (q->num_buffers < q->min_buffers_needed) {
2204 dprintk(1, "need at least %u allocated buffers\n",
2205 q->min_buffers_needed);
2210 * Tell driver to start streaming provided sufficient buffers
2213 if (q->queued_count >= q->min_buffers_needed) {
2214 ret = vb2_start_streaming(q);
2216 __vb2_queue_cancel(q);
2223 dprintk(3, "successful\n");
2228 * vb2_queue_error() - signal a fatal error on the queue
2229 * @q: videobuf2 queue
2231 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2232 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2233 * buffers will return -EIO.
2235 * The error flag will be cleared when cancelling the queue, either from
2236 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2237 * function before starting the stream, otherwise the error flag will remain set
2238 * until the queue is released when closing the device node.
2240 void vb2_queue_error(struct vb2_queue *q)
2244 wake_up_all(&q->done_wq);
2246 EXPORT_SYMBOL_GPL(vb2_queue_error);
2249 * vb2_streamon - start streaming
2250 * @q: videobuf2 queue
2251 * @type: type argument passed from userspace to vidioc_streamon handler
2253 * Should be called from vidioc_streamon handler of a driver.
2255 * 1) verifies current state
2256 * 2) passes any previously queued buffers to the driver and starts streaming
2258 * The return values from this function are intended to be directly returned
2259 * from vidioc_streamon handler in the driver.
2261 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2263 if (vb2_fileio_is_active(q)) {
2264 dprintk(1, "file io in progress\n");
2267 return vb2_internal_streamon(q, type);
2269 EXPORT_SYMBOL_GPL(vb2_streamon);
2271 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2273 if (type != q->type) {
2274 dprintk(1, "invalid stream type\n");
2279 * Cancel will pause streaming and remove all buffers from the driver
2280 * and videobuf, effectively returning control over them to userspace.
2282 * Note that we do this even if q->streaming == 0: if you prepare or
2283 * queue buffers, and then call streamoff without ever having called
2284 * streamon, you would still expect those buffers to be returned to
2285 * their normal dequeued state.
2287 __vb2_queue_cancel(q);
2288 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2290 dprintk(3, "successful\n");
2295 * vb2_streamoff - stop streaming
2296 * @q: videobuf2 queue
2297 * @type: type argument passed from userspace to vidioc_streamoff handler
2299 * Should be called from vidioc_streamoff handler of a driver.
2301 * 1) verifies current state,
2302 * 2) stop streaming and dequeues any queued buffers, including those previously
2303 * passed to the driver (after waiting for the driver to finish).
2305 * This call can be used for pausing playback.
2306 * The return values from this function are intended to be directly returned
2307 * from vidioc_streamoff handler in the driver
2309 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2311 if (vb2_fileio_is_active(q)) {
2312 dprintk(1, "file io in progress\n");
2315 return vb2_internal_streamoff(q, type);
2317 EXPORT_SYMBOL_GPL(vb2_streamoff);
2320 * __find_plane_by_offset() - find plane associated with the given offset off
2322 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2323 unsigned int *_buffer, unsigned int *_plane)
2325 struct vb2_buffer *vb;
2326 unsigned int buffer, plane;
2329 * Go over all buffers and their planes, comparing the given offset
2330 * with an offset assigned to each plane. If a match is found,
2331 * return its buffer and plane numbers.
2333 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2334 vb = q->bufs[buffer];
2336 for (plane = 0; plane < vb->num_planes; ++plane) {
2337 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2349 * vb2_expbuf() - Export a buffer as a file descriptor
2350 * @q: videobuf2 queue
2351 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2354 * The return values from this function are intended to be directly returned
2355 * from vidioc_expbuf handler in driver.
2357 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2359 struct vb2_buffer *vb = NULL;
2360 struct vb2_plane *vb_plane;
2362 struct dma_buf *dbuf;
2364 if (q->memory != V4L2_MEMORY_MMAP) {
2365 dprintk(1, "queue is not currently set up for mmap\n");
2369 if (!q->mem_ops->get_dmabuf) {
2370 dprintk(1, "queue does not support DMA buffer exporting\n");
2374 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2375 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2379 if (eb->type != q->type) {
2380 dprintk(1, "invalid buffer type\n");
2384 if (eb->index >= q->num_buffers) {
2385 dprintk(1, "buffer index out of range\n");
2389 vb = q->bufs[eb->index];
2391 if (eb->plane >= vb->num_planes) {
2392 dprintk(1, "buffer plane out of range\n");
2396 if (vb2_fileio_is_active(q)) {
2397 dprintk(1, "expbuf: file io in progress\n");
2401 vb_plane = &vb->planes[eb->plane];
2403 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2404 if (IS_ERR_OR_NULL(dbuf)) {
2405 dprintk(1, "failed to export buffer %d, plane %d\n",
2406 eb->index, eb->plane);
2410 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2412 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2413 eb->index, eb->plane, ret);
2418 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2419 eb->index, eb->plane, ret);
2424 EXPORT_SYMBOL_GPL(vb2_expbuf);
2427 * vb2_mmap() - map video buffers into application address space
2428 * @q: videobuf2 queue
2429 * @vma: vma passed to the mmap file operation handler in the driver
2431 * Should be called from mmap file operation handler of a driver.
2432 * This function maps one plane of one of the available video buffers to
2433 * userspace. To map whole video memory allocated on reqbufs, this function
2434 * has to be called once per each plane per each buffer previously allocated.
2436 * When the userspace application calls mmap, it passes to it an offset returned
2437 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2438 * a "cookie", which is then used to identify the plane to be mapped.
2439 * This function finds a plane with a matching offset and a mapping is performed
2440 * by the means of a provided memory operation.
2442 * The return values from this function are intended to be directly returned
2443 * from the mmap handler in driver.
2445 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2447 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2448 struct vb2_buffer *vb;
2449 unsigned int buffer = 0, plane = 0;
2451 unsigned long length;
2453 if (q->memory != V4L2_MEMORY_MMAP) {
2454 dprintk(1, "queue is not currently set up for mmap\n");
2459 * Check memory area access mode.
2461 if (!(vma->vm_flags & VM_SHARED)) {
2462 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2465 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2466 if (!(vma->vm_flags & VM_WRITE)) {
2467 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2471 if (!(vma->vm_flags & VM_READ)) {
2472 dprintk(1, "invalid vma flags, VM_READ needed\n");
2476 if (vb2_fileio_is_active(q)) {
2477 dprintk(1, "mmap: file io in progress\n");
2482 * Find the plane corresponding to the offset passed by userspace.
2484 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2488 vb = q->bufs[buffer];
2491 * MMAP requires page_aligned buffers.
2492 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2493 * so, we need to do the same here.
2495 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2496 if (length < (vma->vm_end - vma->vm_start)) {
2498 "MMAP invalid, as it would overflow buffer length\n");
2502 mutex_lock(&q->mmap_lock);
2503 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2504 mutex_unlock(&q->mmap_lock);
2508 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2511 EXPORT_SYMBOL_GPL(vb2_mmap);
2514 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2517 unsigned long pgoff,
2518 unsigned long flags)
2520 unsigned long off = pgoff << PAGE_SHIFT;
2521 struct vb2_buffer *vb;
2522 unsigned int buffer, plane;
2526 if (q->memory != V4L2_MEMORY_MMAP) {
2527 dprintk(1, "queue is not currently set up for mmap\n");
2532 * Find the plane corresponding to the offset passed by userspace.
2534 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2538 vb = q->bufs[buffer];
2540 vaddr = vb2_plane_vaddr(vb, plane);
2541 return vaddr ? (unsigned long)vaddr : -EINVAL;
2543 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2546 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2547 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2550 * vb2_poll() - implements poll userspace operation
2551 * @q: videobuf2 queue
2552 * @file: file argument passed to the poll file operation handler
2553 * @wait: wait argument passed to the poll file operation handler
2555 * This function implements poll file operation handler for a driver.
2556 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2557 * be informed that the file descriptor of a video device is available for
2559 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2560 * will be reported as available for writing.
2562 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2565 * The return values from this function are intended to be directly returned
2566 * from poll handler in driver.
2568 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2570 struct video_device *vfd = video_devdata(file);
2571 unsigned long req_events = poll_requested_events(wait);
2572 struct vb2_buffer *vb = NULL;
2573 unsigned int res = 0;
2574 unsigned long flags;
2576 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2577 struct v4l2_fh *fh = file->private_data;
2579 if (v4l2_event_pending(fh))
2581 else if (req_events & POLLPRI)
2582 poll_wait(file, &fh->wait, wait);
2585 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2587 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2591 * Start file I/O emulator only if streaming API has not been used yet.
2593 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2594 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2595 (req_events & (POLLIN | POLLRDNORM))) {
2596 if (__vb2_init_fileio(q, 1))
2597 return res | POLLERR;
2599 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2600 (req_events & (POLLOUT | POLLWRNORM))) {
2601 if (__vb2_init_fileio(q, 0))
2602 return res | POLLERR;
2604 * Write to OUTPUT queue can be done immediately.
2606 return res | POLLOUT | POLLWRNORM;
2611 * There is nothing to wait for if the queue isn't streaming, or if the
2612 * error flag is set.
2614 if (!vb2_is_streaming(q) || q->error)
2615 return res | POLLERR;
2617 * For compatibility with vb1: if QBUF hasn't been called yet, then
2618 * return POLLERR as well. This only affects capture queues, output
2619 * queues will always initialize waiting_for_buffers to false.
2621 if (q->waiting_for_buffers)
2622 return res | POLLERR;
2625 * For output streams you can write as long as there are fewer buffers
2626 * queued than there are buffers available.
2628 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2629 return res | POLLOUT | POLLWRNORM;
2631 if (list_empty(&q->done_list))
2632 poll_wait(file, &q->done_wq, wait);
2635 * Take first buffer available for dequeuing.
2637 spin_lock_irqsave(&q->done_lock, flags);
2638 if (!list_empty(&q->done_list))
2639 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2641 spin_unlock_irqrestore(&q->done_lock, flags);
2643 if (vb && (vb->state == VB2_BUF_STATE_DONE
2644 || vb->state == VB2_BUF_STATE_ERROR)) {
2645 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2646 res | POLLOUT | POLLWRNORM :
2647 res | POLLIN | POLLRDNORM;
2651 EXPORT_SYMBOL_GPL(vb2_poll);
2654 * vb2_queue_init() - initialize a videobuf2 queue
2655 * @q: videobuf2 queue; this structure should be allocated in driver
2657 * The vb2_queue structure should be allocated by the driver. The driver is
2658 * responsible of clearing it's content and setting initial values for some
2659 * required entries before calling this function.
2660 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2661 * to the struct vb2_queue description in include/media/videobuf2-core.h
2662 * for more information.
2664 int vb2_queue_init(struct vb2_queue *q)
2671 WARN_ON(!q->mem_ops) ||
2672 WARN_ON(!q->type) ||
2673 WARN_ON(!q->io_modes) ||
2674 WARN_ON(!q->ops->queue_setup) ||
2675 WARN_ON(!q->ops->buf_queue) ||
2676 WARN_ON(q->timestamp_flags &
2677 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2678 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2681 /* Warn that the driver should choose an appropriate timestamp type */
2682 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2683 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2685 INIT_LIST_HEAD(&q->queued_list);
2686 INIT_LIST_HEAD(&q->done_list);
2687 spin_lock_init(&q->done_lock);
2688 mutex_init(&q->mmap_lock);
2689 init_waitqueue_head(&q->done_wq);
2691 if (q->buf_struct_size == 0)
2692 q->buf_struct_size = sizeof(struct vb2_buffer);
2696 EXPORT_SYMBOL_GPL(vb2_queue_init);
2699 * vb2_queue_release() - stop streaming, release the queue and free memory
2700 * @q: videobuf2 queue
2702 * This function stops streaming and performs necessary clean ups, including
2703 * freeing video buffer memory. The driver is responsible for freeing
2704 * the vb2_queue structure itself.
2706 void vb2_queue_release(struct vb2_queue *q)
2708 __vb2_cleanup_fileio(q);
2709 __vb2_queue_cancel(q);
2710 mutex_lock(&q->mmap_lock);
2711 __vb2_queue_free(q, q->num_buffers);
2712 mutex_unlock(&q->mmap_lock);
2714 EXPORT_SYMBOL_GPL(vb2_queue_release);
2717 * struct vb2_fileio_buf - buffer context used by file io emulator
2719 * vb2 provides a compatibility layer and emulator of file io (read and
2720 * write) calls on top of streaming API. This structure is used for
2721 * tracking context related to the buffers.
2723 struct vb2_fileio_buf {
2727 unsigned int queued:1;
2731 * struct vb2_fileio_data - queue context used by file io emulator
2733 * @cur_index: the index of the buffer currently being read from or
2734 * written to. If equal to q->num_buffers then a new buffer
2736 * @initial_index: in the read() case all buffers are queued up immediately
2737 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2738 * buffers. However, in the write() case no buffers are initially
2739 * queued, instead whenever a buffer is full it is queued up by
2740 * __vb2_perform_fileio(). Only once all available buffers have
2741 * been queued up will __vb2_perform_fileio() start to dequeue
2742 * buffers. This means that initially __vb2_perform_fileio()
2743 * needs to know what buffer index to use when it is queuing up
2744 * the buffers for the first time. That initial index is stored
2745 * in this field. Once it is equal to q->num_buffers all
2746 * available buffers have been queued and __vb2_perform_fileio()
2747 * should start the normal dequeue/queue cycle.
2749 * vb2 provides a compatibility layer and emulator of file io (read and
2750 * write) calls on top of streaming API. For proper operation it required
2751 * this structure to save the driver state between each call of the read
2752 * or write function.
2754 struct vb2_fileio_data {
2755 struct v4l2_requestbuffers req;
2756 struct v4l2_plane p;
2757 struct v4l2_buffer b;
2758 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2759 unsigned int cur_index;
2760 unsigned int initial_index;
2761 unsigned int q_count;
2762 unsigned int dq_count;
2767 * __vb2_init_fileio() - initialize file io emulator
2768 * @q: videobuf2 queue
2769 * @read: mode selector (1 means read, 0 means write)
2771 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2773 struct vb2_fileio_data *fileio;
2775 unsigned int count = 0;
2780 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2781 (!read && !(q->io_modes & VB2_WRITE))))
2785 * Check if device supports mapping buffers to kernel virtual space.
2787 if (!q->mem_ops->vaddr)
2791 * Check if streaming api has not been already activated.
2793 if (q->streaming || q->num_buffers > 0)
2797 * Start with count 1, driver can increase it in queue_setup()
2801 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2802 (read) ? "read" : "write", count, q->io_flags);
2804 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2808 fileio->flags = q->io_flags;
2811 * Request buffers and use MMAP type to force driver
2812 * to allocate buffers by itself.
2814 fileio->req.count = count;
2815 fileio->req.memory = V4L2_MEMORY_MMAP;
2816 fileio->req.type = q->type;
2818 ret = __reqbufs(q, &fileio->req);
2823 * Check if plane_count is correct
2824 * (multiplane buffers are not supported).
2826 if (q->bufs[0]->num_planes != 1) {
2832 * Get kernel address of each buffer.
2834 for (i = 0; i < q->num_buffers; i++) {
2835 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2836 if (fileio->bufs[i].vaddr == NULL) {
2840 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2844 * Read mode requires pre queuing of all buffers.
2847 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2850 * Queue all buffers.
2852 for (i = 0; i < q->num_buffers; i++) {
2853 struct v4l2_buffer *b = &fileio->b;
2855 memset(b, 0, sizeof(*b));
2857 if (is_multiplanar) {
2858 memset(&fileio->p, 0, sizeof(fileio->p));
2859 b->m.planes = &fileio->p;
2862 b->memory = q->memory;
2864 ret = vb2_internal_qbuf(q, b);
2867 fileio->bufs[i].queued = 1;
2870 * All buffers have been queued, so mark that by setting
2871 * initial_index to q->num_buffers
2873 fileio->initial_index = q->num_buffers;
2874 fileio->cur_index = q->num_buffers;
2880 ret = vb2_internal_streamon(q, q->type);
2887 fileio->req.count = 0;
2888 __reqbufs(q, &fileio->req);
2897 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2898 * @q: videobuf2 queue
2900 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2902 struct vb2_fileio_data *fileio = q->fileio;
2905 vb2_internal_streamoff(q, q->type);
2907 fileio->req.count = 0;
2908 vb2_reqbufs(q, &fileio->req);
2910 dprintk(3, "file io emulator closed\n");
2916 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2917 * @q: videobuf2 queue
2918 * @data: pointed to target userspace buffer
2919 * @count: number of bytes to read or write
2920 * @ppos: file handle position tracking pointer
2921 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2922 * @read: access mode selector (1 means read, 0 means write)
2924 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2925 loff_t *ppos, int nonblock, int read)
2927 struct vb2_fileio_data *fileio;
2928 struct vb2_fileio_buf *buf;
2929 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2931 * When using write() to write data to an output video node the vb2 core
2932 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2933 * else is able to provide this information with the write() operation.
2935 bool set_timestamp = !read &&
2936 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2937 V4L2_BUF_FLAG_TIMESTAMP_COPY;
2940 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2941 read ? "read" : "write", (long)*ppos, count,
2942 nonblock ? "non" : "");
2948 * Initialize emulator on first call.
2950 if (!vb2_fileio_is_active(q)) {
2951 ret = __vb2_init_fileio(q, read);
2952 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2959 * Check if we need to dequeue the buffer.
2961 index = fileio->cur_index;
2962 if (index >= q->num_buffers) {
2964 * Call vb2_dqbuf to get buffer back.
2966 memset(&fileio->b, 0, sizeof(fileio->b));
2967 fileio->b.type = q->type;
2968 fileio->b.memory = q->memory;
2969 if (is_multiplanar) {
2970 memset(&fileio->p, 0, sizeof(fileio->p));
2971 fileio->b.m.planes = &fileio->p;
2972 fileio->b.length = 1;
2974 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
2975 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2978 fileio->dq_count += 1;
2980 fileio->cur_index = index = fileio->b.index;
2981 buf = &fileio->bufs[index];
2984 * Get number of bytes filled by the driver
2988 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2989 : vb2_plane_size(q->bufs[index], 0);
2990 /* Compensate for data_offset on read in the multiplanar case. */
2991 if (is_multiplanar && read &&
2992 fileio->b.m.planes[0].data_offset < buf->size) {
2993 buf->pos = fileio->b.m.planes[0].data_offset;
2994 buf->size -= buf->pos;
2997 buf = &fileio->bufs[index];
3001 * Limit count on last few bytes of the buffer.
3003 if (buf->pos + count > buf->size) {
3004 count = buf->size - buf->pos;
3005 dprintk(5, "reducing read count: %zd\n", count);
3009 * Transfer data to userspace.
3011 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3012 count, index, buf->pos);
3014 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3016 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3018 dprintk(3, "error copying data\n");
3029 * Queue next buffer if required.
3031 if (buf->pos == buf->size ||
3032 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
3034 * Check if this is the last buffer to read.
3036 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
3037 fileio->dq_count == 1) {
3038 dprintk(3, "read limit reached\n");
3039 return __vb2_cleanup_fileio(q);
3043 * Call vb2_qbuf and give buffer to the driver.
3045 memset(&fileio->b, 0, sizeof(fileio->b));
3046 fileio->b.type = q->type;
3047 fileio->b.memory = q->memory;
3048 fileio->b.index = index;
3049 fileio->b.bytesused = buf->pos;
3050 if (is_multiplanar) {
3051 memset(&fileio->p, 0, sizeof(fileio->p));
3052 fileio->p.bytesused = buf->pos;
3053 fileio->b.m.planes = &fileio->p;
3054 fileio->b.length = 1;
3057 v4l2_get_timestamp(&fileio->b.timestamp);
3058 ret = vb2_internal_qbuf(q, &fileio->b);
3059 dprintk(5, "vb2_dbuf result: %d\n", ret);
3064 * Buffer has been queued, update the status
3068 buf->size = vb2_plane_size(q->bufs[index], 0);
3069 fileio->q_count += 1;
3071 * If we are queuing up buffers for the first time, then
3072 * increase initial_index by one.
3074 if (fileio->initial_index < q->num_buffers)
3075 fileio->initial_index++;
3077 * The next buffer to use is either a buffer that's going to be
3078 * queued for the first time (initial_index < q->num_buffers)
3079 * or it is equal to q->num_buffers, meaning that the next
3080 * time we need to dequeue a buffer since we've now queued up
3081 * all the 'first time' buffers.
3083 fileio->cur_index = fileio->initial_index;
3087 * Return proper number of bytes processed.
3094 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3095 loff_t *ppos, int nonblocking)
3097 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3099 EXPORT_SYMBOL_GPL(vb2_read);
3101 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3102 loff_t *ppos, int nonblocking)
3104 return __vb2_perform_fileio(q, (char __user *) data, count,
3105 ppos, nonblocking, 0);
3107 EXPORT_SYMBOL_GPL(vb2_write);
3109 struct vb2_threadio_data {
3110 struct task_struct *thread;
3116 static int vb2_thread(void *data)
3118 struct vb2_queue *q = data;
3119 struct vb2_threadio_data *threadio = q->threadio;
3120 struct vb2_fileio_data *fileio = q->fileio;
3121 bool set_timestamp = false;
3126 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3127 prequeue = q->num_buffers;
3129 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3130 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3136 struct vb2_buffer *vb;
3139 * Call vb2_dqbuf to get buffer back.
3141 memset(&fileio->b, 0, sizeof(fileio->b));
3142 fileio->b.type = q->type;
3143 fileio->b.memory = q->memory;
3145 fileio->b.index = index++;
3148 call_void_qop(q, wait_finish, q);
3149 if (!threadio->stop)
3150 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3151 call_void_qop(q, wait_prepare, q);
3152 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3154 if (ret || threadio->stop)
3158 vb = q->bufs[fileio->b.index];
3159 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3160 if (threadio->fnc(vb, threadio->priv))
3162 call_void_qop(q, wait_finish, q);
3164 v4l2_get_timestamp(&fileio->b.timestamp);
3165 if (!threadio->stop)
3166 ret = vb2_internal_qbuf(q, &fileio->b);
3167 call_void_qop(q, wait_prepare, q);
3168 if (ret || threadio->stop)
3172 /* Hmm, linux becomes *very* unhappy without this ... */
3173 while (!kthread_should_stop()) {
3174 set_current_state(TASK_INTERRUPTIBLE);
3181 * This function should not be used for anything else but the videobuf2-dvb
3182 * support. If you think you have another good use-case for this, then please
3183 * contact the linux-media mailinglist first.
3185 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3186 const char *thread_name)
3188 struct vb2_threadio_data *threadio;
3195 if (WARN_ON(q->fileio))
3198 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3199 if (threadio == NULL)
3201 threadio->fnc = fnc;
3202 threadio->priv = priv;
3204 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3205 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3208 q->threadio = threadio;
3209 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3210 if (IS_ERR(threadio->thread)) {
3211 ret = PTR_ERR(threadio->thread);
3212 threadio->thread = NULL;
3218 __vb2_cleanup_fileio(q);
3223 EXPORT_SYMBOL_GPL(vb2_thread_start);
3225 int vb2_thread_stop(struct vb2_queue *q)
3227 struct vb2_threadio_data *threadio = q->threadio;
3228 struct vb2_fileio_data *fileio = q->fileio;
3231 if (threadio == NULL)
3233 threadio->stop = true;
3234 /* Wake up all pending sleeps in the thread */
3236 err = kthread_stop(threadio->thread);
3237 __vb2_cleanup_fileio(q);
3238 threadio->thread = NULL;
3243 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3246 * The following functions are not part of the vb2 core API, but are helper
3247 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3248 * and struct vb2_ops.
3249 * They contain boilerplate code that most if not all drivers have to do
3250 * and so they simplify the driver code.
3253 /* The queue is busy if there is a owner and you are not that owner. */
3254 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3256 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3259 /* vb2 ioctl helpers */
3261 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3262 struct v4l2_requestbuffers *p)
3264 struct video_device *vdev = video_devdata(file);
3265 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3269 if (vb2_queue_is_busy(vdev, file))
3271 res = __reqbufs(vdev->queue, p);
3272 /* If count == 0, then the owner has released all buffers and he
3273 is no longer owner of the queue. Otherwise we have a new owner. */
3275 vdev->queue->owner = p->count ? file->private_data : NULL;
3278 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3280 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3281 struct v4l2_create_buffers *p)
3283 struct video_device *vdev = video_devdata(file);
3284 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3286 p->index = vdev->queue->num_buffers;
3287 /* If count == 0, then just check if memory and type are valid.
3288 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3290 return res != -EBUSY ? res : 0;
3293 if (vb2_queue_is_busy(vdev, file))
3295 res = __create_bufs(vdev->queue, p);
3297 vdev->queue->owner = file->private_data;
3300 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3302 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3303 struct v4l2_buffer *p)
3305 struct video_device *vdev = video_devdata(file);
3307 if (vb2_queue_is_busy(vdev, file))
3309 return vb2_prepare_buf(vdev->queue, p);
3311 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3313 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3315 struct video_device *vdev = video_devdata(file);
3317 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3318 return vb2_querybuf(vdev->queue, p);
3320 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3322 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3324 struct video_device *vdev = video_devdata(file);
3326 if (vb2_queue_is_busy(vdev, file))
3328 return vb2_qbuf(vdev->queue, p);
3330 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3332 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3334 struct video_device *vdev = video_devdata(file);
3336 if (vb2_queue_is_busy(vdev, file))
3338 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3340 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3342 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3344 struct video_device *vdev = video_devdata(file);
3346 if (vb2_queue_is_busy(vdev, file))
3348 return vb2_streamon(vdev->queue, i);
3350 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3352 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3354 struct video_device *vdev = video_devdata(file);
3356 if (vb2_queue_is_busy(vdev, file))
3358 return vb2_streamoff(vdev->queue, i);
3360 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3362 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3364 struct video_device *vdev = video_devdata(file);
3366 if (vb2_queue_is_busy(vdev, file))
3368 return vb2_expbuf(vdev->queue, p);
3370 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3372 /* v4l2_file_operations helpers */
3374 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3376 struct video_device *vdev = video_devdata(file);
3378 return vb2_mmap(vdev->queue, vma);
3380 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3382 int _vb2_fop_release(struct file *file, struct mutex *lock)
3384 struct video_device *vdev = video_devdata(file);
3388 if (file->private_data == vdev->queue->owner) {
3389 vb2_queue_release(vdev->queue);
3390 vdev->queue->owner = NULL;
3394 return v4l2_fh_release(file);
3396 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3398 int vb2_fop_release(struct file *file)
3400 struct video_device *vdev = video_devdata(file);
3401 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3403 return _vb2_fop_release(file, lock);
3405 EXPORT_SYMBOL_GPL(vb2_fop_release);
3407 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3408 size_t count, loff_t *ppos)
3410 struct video_device *vdev = video_devdata(file);
3411 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3414 if (lock && mutex_lock_interruptible(lock))
3415 return -ERESTARTSYS;
3416 if (vb2_queue_is_busy(vdev, file))
3418 err = vb2_write(vdev->queue, buf, count, ppos,
3419 file->f_flags & O_NONBLOCK);
3420 if (vdev->queue->fileio)
3421 vdev->queue->owner = file->private_data;
3427 EXPORT_SYMBOL_GPL(vb2_fop_write);
3429 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3430 size_t count, loff_t *ppos)
3432 struct video_device *vdev = video_devdata(file);
3433 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3436 if (lock && mutex_lock_interruptible(lock))
3437 return -ERESTARTSYS;
3438 if (vb2_queue_is_busy(vdev, file))
3440 err = vb2_read(vdev->queue, buf, count, ppos,
3441 file->f_flags & O_NONBLOCK);
3442 if (vdev->queue->fileio)
3443 vdev->queue->owner = file->private_data;
3449 EXPORT_SYMBOL_GPL(vb2_fop_read);
3451 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3453 struct video_device *vdev = video_devdata(file);
3454 struct vb2_queue *q = vdev->queue;
3455 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3460 * If this helper doesn't know how to lock, then you shouldn't be using
3461 * it but you should write your own.
3465 if (lock && mutex_lock_interruptible(lock))
3470 res = vb2_poll(vdev->queue, file, wait);
3472 /* If fileio was started, then we have a new queue owner. */
3473 if (!fileio && q->fileio)
3474 q->owner = file->private_data;
3479 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3482 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3483 unsigned long len, unsigned long pgoff, unsigned long flags)
3485 struct video_device *vdev = video_devdata(file);
3487 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3489 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3492 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3494 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3496 mutex_unlock(vq->lock);
3498 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3500 void vb2_ops_wait_finish(struct vb2_queue *vq)
3502 mutex_lock(vq->lock);
3504 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3506 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3507 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3508 MODULE_LICENSE("GPL");