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:
718 case VB2_BUF_STATE_REQUEUEING:
723 if (__buffer_in_use(q, vb))
724 b->flags |= V4L2_BUF_FLAG_MAPPED;
728 * vb2_querybuf() - query video buffer information
730 * @b: buffer struct passed from userspace to vidioc_querybuf handler
733 * Should be called from vidioc_querybuf ioctl handler in driver.
734 * This function will verify the passed v4l2_buffer structure and fill the
735 * relevant information for the userspace.
737 * The return values from this function are intended to be directly returned
738 * from vidioc_querybuf handler in driver.
740 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
742 struct vb2_buffer *vb;
745 if (b->type != q->type) {
746 dprintk(1, "wrong buffer type\n");
750 if (b->index >= q->num_buffers) {
751 dprintk(1, "buffer index out of range\n");
754 vb = q->bufs[b->index];
755 ret = __verify_planes_array(vb, b);
757 __fill_v4l2_buffer(vb, b);
760 EXPORT_SYMBOL(vb2_querybuf);
763 * __verify_userptr_ops() - verify that all memory operations required for
764 * USERPTR queue type have been provided
766 static int __verify_userptr_ops(struct vb2_queue *q)
768 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
769 !q->mem_ops->put_userptr)
776 * __verify_mmap_ops() - verify that all memory operations required for
777 * MMAP queue type have been provided
779 static int __verify_mmap_ops(struct vb2_queue *q)
781 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
782 !q->mem_ops->put || !q->mem_ops->mmap)
789 * __verify_dmabuf_ops() - verify that all memory operations required for
790 * DMABUF queue type have been provided
792 static int __verify_dmabuf_ops(struct vb2_queue *q)
794 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
795 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
796 !q->mem_ops->unmap_dmabuf)
803 * __verify_memory_type() - Check whether the memory type and buffer type
804 * passed to a buffer operation are compatible with the queue.
806 static int __verify_memory_type(struct vb2_queue *q,
807 enum v4l2_memory memory, enum v4l2_buf_type type)
809 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
810 memory != V4L2_MEMORY_DMABUF) {
811 dprintk(1, "unsupported memory type\n");
815 if (type != q->type) {
816 dprintk(1, "requested type is incorrect\n");
821 * Make sure all the required memory ops for given memory type
824 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
825 dprintk(1, "MMAP for current setup unsupported\n");
829 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
830 dprintk(1, "USERPTR for current setup unsupported\n");
834 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
835 dprintk(1, "DMABUF for current setup unsupported\n");
840 * Place the busy tests at the end: -EBUSY can be ignored when
841 * create_bufs is called with count == 0, but count == 0 should still
842 * do the memory and type validation.
844 if (vb2_fileio_is_active(q)) {
845 dprintk(1, "file io in progress\n");
852 * __reqbufs() - Initiate streaming
853 * @q: videobuf2 queue
854 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
856 * Should be called from vidioc_reqbufs ioctl handler of a driver.
858 * 1) verifies streaming parameters passed from the userspace,
859 * 2) sets up the queue,
860 * 3) negotiates number of buffers and planes per buffer with the driver
861 * to be used during streaming,
862 * 4) allocates internal buffer structures (struct vb2_buffer), according to
863 * the agreed parameters,
864 * 5) for MMAP memory type, allocates actual video memory, using the
865 * memory handling/allocation routines provided during queue initialization
867 * If req->count is 0, all the memory will be freed instead.
868 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
869 * and the queue is not busy, memory will be reallocated.
871 * The return values from this function are intended to be directly returned
872 * from vidioc_reqbufs handler in driver.
874 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
876 unsigned int num_buffers, allocated_buffers, num_planes = 0;
880 dprintk(1, "streaming active\n");
884 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
886 * We already have buffers allocated, so first check if they
887 * are not in use and can be freed.
889 mutex_lock(&q->mmap_lock);
890 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
891 mutex_unlock(&q->mmap_lock);
892 dprintk(1, "memory in use, cannot free\n");
897 * Call queue_cancel to clean up any buffers in the PREPARED or
898 * QUEUED state which is possible if buffers were prepared or
899 * queued without ever calling STREAMON.
901 __vb2_queue_cancel(q);
902 ret = __vb2_queue_free(q, q->num_buffers);
903 mutex_unlock(&q->mmap_lock);
908 * In case of REQBUFS(0) return immediately without calling
909 * driver's queue_setup() callback and allocating resources.
916 * Make sure the requested values and current defaults are sane.
918 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
919 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
920 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
921 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
922 q->memory = req->memory;
925 * Ask the driver how many buffers and planes per buffer it requires.
926 * Driver also sets the size and allocator context for each plane.
928 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
929 q->plane_sizes, q->alloc_ctx);
933 /* Finally, allocate buffers and video memory */
934 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
935 if (allocated_buffers == 0) {
936 dprintk(1, "memory allocation failed\n");
941 * There is no point in continuing if we can't allocate the minimum
942 * number of buffers needed by this vb2_queue.
944 if (allocated_buffers < q->min_buffers_needed)
948 * Check if driver can handle the allocated number of buffers.
950 if (!ret && allocated_buffers < num_buffers) {
951 num_buffers = allocated_buffers;
953 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
954 &num_planes, q->plane_sizes, q->alloc_ctx);
956 if (!ret && allocated_buffers < num_buffers)
960 * Either the driver has accepted a smaller number of buffers,
961 * or .queue_setup() returned an error
965 mutex_lock(&q->mmap_lock);
966 q->num_buffers = allocated_buffers;
970 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
971 * from q->num_buffers.
973 __vb2_queue_free(q, allocated_buffers);
974 mutex_unlock(&q->mmap_lock);
977 mutex_unlock(&q->mmap_lock);
980 * Return the number of successfully allocated buffers
983 req->count = allocated_buffers;
984 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
990 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
992 * @q: videobuf2 queue
993 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
995 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
997 int ret = __verify_memory_type(q, req->memory, req->type);
999 return ret ? ret : __reqbufs(q, req);
1001 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1004 * __create_bufs() - Allocate buffers and any required auxiliary structs
1005 * @q: videobuf2 queue
1006 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1009 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1011 * 1) verifies parameter sanity
1012 * 2) calls the .queue_setup() queue operation
1013 * 3) performs any necessary memory allocations
1015 * The return values from this function are intended to be directly returned
1016 * from vidioc_create_bufs handler in driver.
1018 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1020 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1023 if (q->num_buffers == VIDEO_MAX_FRAME) {
1024 dprintk(1, "maximum number of buffers already allocated\n");
1028 if (!q->num_buffers) {
1029 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1030 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1031 q->memory = create->memory;
1032 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1035 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1038 * Ask the driver, whether the requested number of buffers, planes per
1039 * buffer and their sizes are acceptable
1041 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1042 &num_planes, q->plane_sizes, q->alloc_ctx);
1046 /* Finally, allocate buffers and video memory */
1047 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1049 if (allocated_buffers == 0) {
1050 dprintk(1, "memory allocation failed\n");
1055 * Check if driver can handle the so far allocated number of buffers.
1057 if (allocated_buffers < num_buffers) {
1058 num_buffers = allocated_buffers;
1061 * q->num_buffers contains the total number of buffers, that the
1062 * queue driver has set up
1064 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1065 &num_planes, q->plane_sizes, q->alloc_ctx);
1067 if (!ret && allocated_buffers < num_buffers)
1071 * Either the driver has accepted a smaller number of buffers,
1072 * or .queue_setup() returned an error
1076 mutex_lock(&q->mmap_lock);
1077 q->num_buffers += allocated_buffers;
1081 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1082 * from q->num_buffers.
1084 __vb2_queue_free(q, allocated_buffers);
1085 mutex_unlock(&q->mmap_lock);
1088 mutex_unlock(&q->mmap_lock);
1091 * Return the number of successfully allocated buffers
1094 create->count = allocated_buffers;
1100 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1101 * memory and type values.
1102 * @q: videobuf2 queue
1103 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1106 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1108 int ret = __verify_memory_type(q, create->memory, create->format.type);
1110 create->index = q->num_buffers;
1111 if (create->count == 0)
1112 return ret != -EBUSY ? ret : 0;
1113 return ret ? ret : __create_bufs(q, create);
1115 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1118 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1119 * @vb: vb2_buffer to which the plane in question belongs to
1120 * @plane_no: plane number for which the address is to be returned
1122 * This function returns a kernel virtual address of a given plane if
1123 * such a mapping exist, NULL otherwise.
1125 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1127 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1130 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1133 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1136 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1137 * @vb: vb2_buffer to which the plane in question belongs to
1138 * @plane_no: plane number for which the cookie is to be returned
1140 * This function returns an allocator specific cookie for a given plane if
1141 * available, NULL otherwise. The allocator should provide some simple static
1142 * inline function, which would convert this cookie to the allocator specific
1143 * type that can be used directly by the driver to access the buffer. This can
1144 * be for example physical address, pointer to scatter list or IOMMU mapping.
1146 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1148 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1151 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1153 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1156 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1157 * @vb: vb2_buffer returned from the driver
1158 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1159 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1160 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1161 * If start_streaming fails then it should return buffers with state
1162 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1164 * This function should be called by the driver after a hardware operation on
1165 * a buffer is finished and the buffer may be returned to userspace. The driver
1166 * cannot use this buffer anymore until it is queued back to it by videobuf
1167 * by the means of buf_queue callback. Only buffers previously queued to the
1168 * driver by buf_queue can be passed to this function.
1170 * While streaming a buffer can only be returned in state DONE or ERROR.
1171 * The start_streaming op can also return them in case the DMA engine cannot
1172 * be started for some reason. In that case the buffers should be returned with
1175 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1177 struct vb2_queue *q = vb->vb2_queue;
1178 unsigned long flags;
1181 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1184 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1185 state != VB2_BUF_STATE_ERROR &&
1186 state != VB2_BUF_STATE_QUEUED &&
1187 state != VB2_BUF_STATE_REQUEUEING))
1188 state = VB2_BUF_STATE_ERROR;
1190 #ifdef CONFIG_VIDEO_ADV_DEBUG
1192 * Although this is not a callback, it still does have to balance
1193 * with the buf_queue op. So update this counter manually.
1197 dprintk(4, "done processing on buffer %d, state: %d\n",
1198 vb->v4l2_buf.index, state);
1201 for (plane = 0; plane < vb->num_planes; ++plane)
1202 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1204 spin_lock_irqsave(&q->done_lock, flags);
1205 if (state == VB2_BUF_STATE_QUEUED ||
1206 state == VB2_BUF_STATE_REQUEUEING) {
1207 vb->state = VB2_BUF_STATE_QUEUED;
1209 /* Add the buffer to the done buffers list */
1210 list_add_tail(&vb->done_entry, &q->done_list);
1213 atomic_dec(&q->owned_by_drv_count);
1214 spin_unlock_irqrestore(&q->done_lock, flags);
1217 case VB2_BUF_STATE_QUEUED:
1219 case VB2_BUF_STATE_REQUEUEING:
1220 if (q->start_streaming_called)
1221 __enqueue_in_driver(vb);
1224 /* Inform any processes that may be waiting for buffers */
1225 wake_up(&q->done_wq);
1229 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1232 * vb2_discard_done() - discard all buffers marked as DONE
1233 * @q: videobuf2 queue
1235 * This function is intended to be used with suspend/resume operations. It
1236 * discards all 'done' buffers as they would be too old to be requested after
1239 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1240 * delayed works before calling this function to make sure no buffer will be
1241 * touched by the driver and/or hardware.
1243 void vb2_discard_done(struct vb2_queue *q)
1245 struct vb2_buffer *vb;
1246 unsigned long flags;
1248 spin_lock_irqsave(&q->done_lock, flags);
1249 list_for_each_entry(vb, &q->done_list, done_entry)
1250 vb->state = VB2_BUF_STATE_ERROR;
1251 spin_unlock_irqrestore(&q->done_lock, flags);
1253 EXPORT_SYMBOL_GPL(vb2_discard_done);
1255 static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
1257 static bool check_once;
1265 pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1266 if (vb->vb2_queue->allow_zero_bytesused)
1267 pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1269 pr_warn("use the actual size instead.\n");
1273 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1274 * v4l2_buffer by the userspace. The caller has already verified that struct
1275 * v4l2_buffer has a valid number of planes.
1277 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1278 struct v4l2_plane *v4l2_planes)
1282 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1283 if (b->memory == V4L2_MEMORY_USERPTR) {
1284 for (plane = 0; plane < vb->num_planes; ++plane) {
1285 v4l2_planes[plane].m.userptr =
1286 b->m.planes[plane].m.userptr;
1287 v4l2_planes[plane].length =
1288 b->m.planes[plane].length;
1291 if (b->memory == V4L2_MEMORY_DMABUF) {
1292 for (plane = 0; plane < vb->num_planes; ++plane) {
1293 v4l2_planes[plane].m.fd =
1294 b->m.planes[plane].m.fd;
1295 v4l2_planes[plane].length =
1296 b->m.planes[plane].length;
1300 /* Fill in driver-provided information for OUTPUT types */
1301 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1303 * Will have to go up to b->length when API starts
1304 * accepting variable number of planes.
1306 * If bytesused == 0 for the output buffer, then fall
1307 * back to the full buffer size. In that case
1308 * userspace clearly never bothered to set it and
1309 * it's a safe assumption that they really meant to
1310 * use the full plane sizes.
1312 * Some drivers, e.g. old codec drivers, use bytesused == 0
1313 * as a way to indicate that streaming is finished.
1314 * In that case, the driver should use the
1315 * allow_zero_bytesused flag to keep old userspace
1316 * applications working.
1318 for (plane = 0; plane < vb->num_planes; ++plane) {
1319 struct v4l2_plane *pdst = &v4l2_planes[plane];
1320 struct v4l2_plane *psrc = &b->m.planes[plane];
1322 if (psrc->bytesused == 0)
1323 vb2_warn_zero_bytesused(vb);
1325 if (vb->vb2_queue->allow_zero_bytesused)
1326 pdst->bytesused = psrc->bytesused;
1328 pdst->bytesused = psrc->bytesused ?
1329 psrc->bytesused : pdst->length;
1330 pdst->data_offset = psrc->data_offset;
1335 * Single-planar buffers do not use planes array,
1336 * so fill in relevant v4l2_buffer struct fields instead.
1337 * In videobuf we use our internal V4l2_planes struct for
1338 * single-planar buffers as well, for simplicity.
1340 * If bytesused == 0 for the output buffer, then fall back
1341 * to the full buffer size as that's a sensible default.
1343 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1344 * a way to indicate that streaming is finished. In that case,
1345 * the driver should use the allow_zero_bytesused flag to keep
1346 * old userspace applications working.
1348 if (b->memory == V4L2_MEMORY_USERPTR) {
1349 v4l2_planes[0].m.userptr = b->m.userptr;
1350 v4l2_planes[0].length = b->length;
1353 if (b->memory == V4L2_MEMORY_DMABUF) {
1354 v4l2_planes[0].m.fd = b->m.fd;
1355 v4l2_planes[0].length = b->length;
1358 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1359 if (b->bytesused == 0)
1360 vb2_warn_zero_bytesused(vb);
1362 if (vb->vb2_queue->allow_zero_bytesused)
1363 v4l2_planes[0].bytesused = b->bytesused;
1365 v4l2_planes[0].bytesused = b->bytesused ?
1366 b->bytesused : v4l2_planes[0].length;
1368 v4l2_planes[0].bytesused = 0;
1372 /* Zero flags that the vb2 core handles */
1373 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1374 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1375 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1377 * Non-COPY timestamps and non-OUTPUT queues will get
1378 * their timestamp and timestamp source flags from the
1381 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1384 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1386 * For output buffers mask out the timecode flag:
1387 * this will be handled later in vb2_internal_qbuf().
1388 * The 'field' is valid metadata for this output buffer
1389 * and so that needs to be copied here.
1391 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1392 vb->v4l2_buf.field = b->field;
1394 /* Zero any output buffer flags as this is a capture buffer */
1395 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1400 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1402 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1404 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1405 return call_vb_qop(vb, buf_prepare, vb);
1409 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1411 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1413 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1414 struct vb2_queue *q = vb->vb2_queue;
1418 enum dma_data_direction dma_dir =
1419 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1420 bool reacquired = vb->planes[0].mem_priv == NULL;
1422 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1423 /* Copy relevant information provided by the userspace */
1424 __fill_vb2_buffer(vb, b, planes);
1426 for (plane = 0; plane < vb->num_planes; ++plane) {
1427 /* Skip the plane if already verified */
1428 if (vb->v4l2_planes[plane].m.userptr &&
1429 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1430 && vb->v4l2_planes[plane].length == planes[plane].length)
1433 dprintk(3, "userspace address for plane %d changed, "
1434 "reacquiring memory\n", plane);
1436 /* Check if the provided plane buffer is large enough */
1437 if (planes[plane].length < q->plane_sizes[plane]) {
1438 dprintk(1, "provided buffer size %u is less than "
1439 "setup size %u for plane %d\n",
1440 planes[plane].length,
1441 q->plane_sizes[plane], plane);
1446 /* Release previously acquired memory if present */
1447 if (vb->planes[plane].mem_priv) {
1450 call_void_vb_qop(vb, buf_cleanup, vb);
1452 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1455 vb->planes[plane].mem_priv = NULL;
1456 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1458 /* Acquire each plane's memory */
1459 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1460 planes[plane].m.userptr,
1461 planes[plane].length, dma_dir);
1462 if (IS_ERR_OR_NULL(mem_priv)) {
1463 dprintk(1, "failed acquiring userspace "
1464 "memory for plane %d\n", plane);
1465 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1468 vb->planes[plane].mem_priv = mem_priv;
1472 * Now that everything is in order, copy relevant information
1473 * provided by userspace.
1475 for (plane = 0; plane < vb->num_planes; ++plane)
1476 vb->v4l2_planes[plane] = planes[plane];
1480 * One or more planes changed, so we must call buf_init to do
1481 * the driver-specific initialization on the newly acquired
1482 * buffer, if provided.
1484 ret = call_vb_qop(vb, buf_init, vb);
1486 dprintk(1, "buffer initialization failed\n");
1491 ret = call_vb_qop(vb, buf_prepare, vb);
1493 dprintk(1, "buffer preparation failed\n");
1494 call_void_vb_qop(vb, buf_cleanup, vb);
1500 /* In case of errors, release planes that were already acquired */
1501 for (plane = 0; plane < vb->num_planes; ++plane) {
1502 if (vb->planes[plane].mem_priv)
1503 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1504 vb->planes[plane].mem_priv = NULL;
1505 vb->v4l2_planes[plane].m.userptr = 0;
1506 vb->v4l2_planes[plane].length = 0;
1513 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1515 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1517 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1518 struct vb2_queue *q = vb->vb2_queue;
1522 enum dma_data_direction dma_dir =
1523 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1524 bool reacquired = vb->planes[0].mem_priv == NULL;
1526 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1527 /* Copy relevant information provided by the userspace */
1528 __fill_vb2_buffer(vb, b, planes);
1530 for (plane = 0; plane < vb->num_planes; ++plane) {
1531 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1533 if (IS_ERR_OR_NULL(dbuf)) {
1534 dprintk(1, "invalid dmabuf fd for plane %d\n",
1540 /* use DMABUF size if length is not provided */
1541 if (planes[plane].length == 0)
1542 planes[plane].length = dbuf->size;
1544 if (planes[plane].length < q->plane_sizes[plane]) {
1545 dprintk(1, "invalid dmabuf length for plane %d\n",
1551 /* Skip the plane if already verified */
1552 if (dbuf == vb->planes[plane].dbuf &&
1553 vb->v4l2_planes[plane].length == planes[plane].length) {
1558 dprintk(1, "buffer for plane %d changed\n", plane);
1562 call_void_vb_qop(vb, buf_cleanup, vb);
1565 /* Release previously acquired memory if present */
1566 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1567 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1569 /* Acquire each plane's memory */
1570 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1571 dbuf, planes[plane].length, dma_dir);
1572 if (IS_ERR(mem_priv)) {
1573 dprintk(1, "failed to attach dmabuf\n");
1574 ret = PTR_ERR(mem_priv);
1579 vb->planes[plane].dbuf = dbuf;
1580 vb->planes[plane].mem_priv = mem_priv;
1583 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1584 * really we want to do this just before the DMA, not while queueing
1587 for (plane = 0; plane < vb->num_planes; ++plane) {
1588 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1590 dprintk(1, "failed to map dmabuf for plane %d\n",
1594 vb->planes[plane].dbuf_mapped = 1;
1598 * Now that everything is in order, copy relevant information
1599 * provided by userspace.
1601 for (plane = 0; plane < vb->num_planes; ++plane)
1602 vb->v4l2_planes[plane] = planes[plane];
1606 * Call driver-specific initialization on the newly acquired buffer,
1609 ret = call_vb_qop(vb, buf_init, vb);
1611 dprintk(1, "buffer initialization failed\n");
1616 ret = call_vb_qop(vb, buf_prepare, vb);
1618 dprintk(1, "buffer preparation failed\n");
1619 call_void_vb_qop(vb, buf_cleanup, vb);
1625 /* In case of errors, release planes that were already acquired */
1626 __vb2_buf_dmabuf_put(vb);
1632 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1634 static void __enqueue_in_driver(struct vb2_buffer *vb)
1636 struct vb2_queue *q = vb->vb2_queue;
1639 vb->state = VB2_BUF_STATE_ACTIVE;
1640 atomic_inc(&q->owned_by_drv_count);
1643 for (plane = 0; plane < vb->num_planes; ++plane)
1644 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1646 call_void_vb_qop(vb, buf_queue, vb);
1649 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1651 struct vb2_queue *q = vb->vb2_queue;
1654 ret = __verify_length(vb, b);
1656 dprintk(1, "plane parameters verification failed: %d\n", ret);
1659 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1661 * If the format's field is ALTERNATE, then the buffer's field
1662 * should be either TOP or BOTTOM, not ALTERNATE since that
1663 * makes no sense. The driver has to know whether the
1664 * buffer represents a top or a bottom field in order to
1665 * program any DMA correctly. Using ALTERNATE is wrong, since
1666 * that just says that it is either a top or a bottom field,
1667 * but not which of the two it is.
1669 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1674 dprintk(1, "fatal error occurred on queue\n");
1678 vb->state = VB2_BUF_STATE_PREPARING;
1679 vb->v4l2_buf.timestamp.tv_sec = 0;
1680 vb->v4l2_buf.timestamp.tv_usec = 0;
1681 vb->v4l2_buf.sequence = 0;
1683 switch (q->memory) {
1684 case V4L2_MEMORY_MMAP:
1685 ret = __qbuf_mmap(vb, b);
1687 case V4L2_MEMORY_USERPTR:
1688 down_read(¤t->mm->mmap_sem);
1689 ret = __qbuf_userptr(vb, b);
1690 up_read(¤t->mm->mmap_sem);
1692 case V4L2_MEMORY_DMABUF:
1693 ret = __qbuf_dmabuf(vb, b);
1696 WARN(1, "Invalid queue type\n");
1701 dprintk(1, "buffer preparation failed: %d\n", ret);
1702 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1707 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1710 if (b->type != q->type) {
1711 dprintk(1, "%s: invalid buffer type\n", opname);
1715 if (b->index >= q->num_buffers) {
1716 dprintk(1, "%s: buffer index out of range\n", opname);
1720 if (q->bufs[b->index] == NULL) {
1721 /* Should never happen */
1722 dprintk(1, "%s: buffer is NULL\n", opname);
1726 if (b->memory != q->memory) {
1727 dprintk(1, "%s: invalid memory type\n", opname);
1731 return __verify_planes_array(q->bufs[b->index], b);
1735 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1736 * @q: videobuf2 queue
1737 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1740 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1742 * 1) verifies the passed buffer,
1743 * 2) calls buf_prepare callback in the driver (if provided), in which
1744 * driver-specific buffer initialization can be performed,
1746 * The return values from this function are intended to be directly returned
1747 * from vidioc_prepare_buf handler in driver.
1749 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1751 struct vb2_buffer *vb;
1754 if (vb2_fileio_is_active(q)) {
1755 dprintk(1, "file io in progress\n");
1759 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1763 vb = q->bufs[b->index];
1764 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1765 dprintk(1, "invalid buffer state %d\n",
1770 ret = __buf_prepare(vb, b);
1772 /* Fill buffer information for the userspace */
1773 __fill_v4l2_buffer(vb, b);
1775 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1779 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1782 * vb2_start_streaming() - Attempt to start streaming.
1783 * @q: videobuf2 queue
1785 * Attempt to start streaming. When this function is called there must be
1786 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1787 * number of buffers required for the DMA engine to function). If the
1788 * @start_streaming op fails it is supposed to return all the driver-owned
1789 * buffers back to vb2 in state QUEUED. Check if that happened and if
1790 * not warn and reclaim them forcefully.
1792 static int vb2_start_streaming(struct vb2_queue *q)
1794 struct vb2_buffer *vb;
1798 * If any buffers were queued before streamon,
1799 * we can now pass them to driver for processing.
1801 list_for_each_entry(vb, &q->queued_list, queued_entry)
1802 __enqueue_in_driver(vb);
1804 /* Tell the driver to start streaming */
1805 q->start_streaming_called = 1;
1806 ret = call_qop(q, start_streaming, q,
1807 atomic_read(&q->owned_by_drv_count));
1811 q->start_streaming_called = 0;
1813 dprintk(1, "driver refused to start streaming\n");
1815 * If you see this warning, then the driver isn't cleaning up properly
1816 * after a failed start_streaming(). See the start_streaming()
1817 * documentation in videobuf2-core.h for more information how buffers
1818 * should be returned to vb2 in start_streaming().
1820 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1824 * Forcefully reclaim buffers if the driver did not
1825 * correctly return them to vb2.
1827 for (i = 0; i < q->num_buffers; ++i) {
1829 if (vb->state == VB2_BUF_STATE_ACTIVE)
1830 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1832 /* Must be zero now */
1833 WARN_ON(atomic_read(&q->owned_by_drv_count));
1836 * If done_list is not empty, then start_streaming() didn't call
1837 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1840 WARN_ON(!list_empty(&q->done_list));
1844 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1846 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1847 struct vb2_buffer *vb;
1852 vb = q->bufs[b->index];
1854 switch (vb->state) {
1855 case VB2_BUF_STATE_DEQUEUED:
1856 ret = __buf_prepare(vb, b);
1860 case VB2_BUF_STATE_PREPARED:
1862 case VB2_BUF_STATE_PREPARING:
1863 dprintk(1, "buffer still being prepared\n");
1866 dprintk(1, "invalid buffer state %d\n", vb->state);
1871 * Add to the queued buffers list, a buffer will stay on it until
1872 * dequeued in dqbuf.
1874 list_add_tail(&vb->queued_entry, &q->queued_list);
1876 q->waiting_for_buffers = false;
1877 vb->state = VB2_BUF_STATE_QUEUED;
1878 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1880 * For output buffers copy the timestamp if needed,
1881 * and the timecode field and flag if needed.
1883 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1884 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1885 vb->v4l2_buf.timestamp = b->timestamp;
1886 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1887 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1888 vb->v4l2_buf.timecode = b->timecode;
1892 * If already streaming, give the buffer to driver for processing.
1893 * If not, the buffer will be given to driver on next streamon.
1895 if (q->start_streaming_called)
1896 __enqueue_in_driver(vb);
1898 /* Fill buffer information for the userspace */
1899 __fill_v4l2_buffer(vb, b);
1902 * If streamon has been called, and we haven't yet called
1903 * start_streaming() since not enough buffers were queued, and
1904 * we now have reached the minimum number of queued buffers,
1905 * then we can finally call start_streaming().
1907 if (q->streaming && !q->start_streaming_called &&
1908 q->queued_count >= q->min_buffers_needed) {
1909 ret = vb2_start_streaming(q);
1914 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1919 * vb2_qbuf() - Queue a buffer from userspace
1920 * @q: videobuf2 queue
1921 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1924 * Should be called from vidioc_qbuf ioctl handler of a driver.
1926 * 1) verifies the passed buffer,
1927 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1928 * which driver-specific buffer initialization can be performed,
1929 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1930 * callback for processing.
1932 * The return values from this function are intended to be directly returned
1933 * from vidioc_qbuf handler in driver.
1935 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1937 if (vb2_fileio_is_active(q)) {
1938 dprintk(1, "file io in progress\n");
1942 return vb2_internal_qbuf(q, b);
1944 EXPORT_SYMBOL_GPL(vb2_qbuf);
1947 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1950 * Will sleep if required for nonblocking == false.
1952 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1955 * All operations on vb_done_list are performed under done_lock
1956 * spinlock protection. However, buffers may be removed from
1957 * it and returned to userspace only while holding both driver's
1958 * lock and the done_lock spinlock. Thus we can be sure that as
1959 * long as we hold the driver's lock, the list will remain not
1960 * empty if list_empty() check succeeds.
1966 if (!q->streaming) {
1967 dprintk(1, "streaming off, will not wait for buffers\n");
1972 dprintk(1, "Queue in error state, will not wait for buffers\n");
1976 if (q->last_buffer_dequeued) {
1977 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1981 if (!list_empty(&q->done_list)) {
1983 * Found a buffer that we were waiting for.
1989 dprintk(1, "nonblocking and no buffers to dequeue, "
1995 * We are streaming and blocking, wait for another buffer to
1996 * become ready or for streamoff. Driver's lock is released to
1997 * allow streamoff or qbuf to be called while waiting.
1999 call_void_qop(q, wait_prepare, q);
2002 * All locks have been released, it is safe to sleep now.
2004 dprintk(3, "will sleep waiting for buffers\n");
2005 ret = wait_event_interruptible(q->done_wq,
2006 !list_empty(&q->done_list) || !q->streaming ||
2010 * We need to reevaluate both conditions again after reacquiring
2011 * the locks or return an error if one occurred.
2013 call_void_qop(q, wait_finish, q);
2015 dprintk(1, "sleep was interrupted\n");
2023 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2025 * Will sleep if required for nonblocking == false.
2027 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
2028 struct v4l2_buffer *b, int nonblocking)
2030 unsigned long flags;
2034 * Wait for at least one buffer to become available on the done_list.
2036 ret = __vb2_wait_for_done_vb(q, nonblocking);
2041 * Driver's lock has been held since we last verified that done_list
2042 * is not empty, so no need for another list_empty(done_list) check.
2044 spin_lock_irqsave(&q->done_lock, flags);
2045 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
2047 * Only remove the buffer from done_list if v4l2_buffer can handle all
2050 ret = __verify_planes_array(*vb, b);
2052 list_del(&(*vb)->done_entry);
2053 spin_unlock_irqrestore(&q->done_lock, flags);
2059 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2060 * @q: videobuf2 queue
2062 * This function will wait until all buffers that have been given to the driver
2063 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2064 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2065 * taken, for example from stop_streaming() callback.
2067 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2069 if (!q->streaming) {
2070 dprintk(1, "streaming off, will not wait for buffers\n");
2074 if (q->start_streaming_called)
2075 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2078 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2081 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2083 static void __vb2_dqbuf(struct vb2_buffer *vb)
2085 struct vb2_queue *q = vb->vb2_queue;
2088 /* nothing to do if the buffer is already dequeued */
2089 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2092 vb->state = VB2_BUF_STATE_DEQUEUED;
2094 /* unmap DMABUF buffer */
2095 if (q->memory == V4L2_MEMORY_DMABUF)
2096 for (i = 0; i < vb->num_planes; ++i) {
2097 if (!vb->planes[i].dbuf_mapped)
2099 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2100 vb->planes[i].dbuf_mapped = 0;
2104 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2106 struct vb2_buffer *vb = NULL;
2109 if (b->type != q->type) {
2110 dprintk(1, "invalid buffer type\n");
2113 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2117 switch (vb->state) {
2118 case VB2_BUF_STATE_DONE:
2119 dprintk(3, "returning done buffer\n");
2121 case VB2_BUF_STATE_ERROR:
2122 dprintk(3, "returning done buffer with errors\n");
2125 dprintk(1, "invalid buffer state\n");
2129 call_void_vb_qop(vb, buf_finish, vb);
2131 /* Fill buffer information for the userspace */
2132 __fill_v4l2_buffer(vb, b);
2133 /* Remove from videobuf queue */
2134 list_del(&vb->queued_entry);
2136 if (!V4L2_TYPE_IS_OUTPUT(q->type) &&
2137 vb->v4l2_buf.flags & V4L2_BUF_FLAG_LAST)
2138 q->last_buffer_dequeued = true;
2139 /* go back to dequeued state */
2142 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2143 vb->v4l2_buf.index, vb->state);
2149 * vb2_dqbuf() - Dequeue a buffer to the userspace
2150 * @q: videobuf2 queue
2151 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2153 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2154 * buffers ready for dequeuing are present. Normally the driver
2155 * would be passing (file->f_flags & O_NONBLOCK) here
2157 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2159 * 1) verifies the passed buffer,
2160 * 2) calls buf_finish callback in the driver (if provided), in which
2161 * driver can perform any additional operations that may be required before
2162 * returning the buffer to userspace, such as cache sync,
2163 * 3) the buffer struct members are filled with relevant information for
2166 * The return values from this function are intended to be directly returned
2167 * from vidioc_dqbuf handler in driver.
2169 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2171 if (vb2_fileio_is_active(q)) {
2172 dprintk(1, "file io in progress\n");
2175 return vb2_internal_dqbuf(q, b, nonblocking);
2177 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2180 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2182 * Removes all queued buffers from driver's queue and all buffers queued by
2183 * userspace from videobuf's queue. Returns to state after reqbufs.
2185 static void __vb2_queue_cancel(struct vb2_queue *q)
2190 * Tell driver to stop all transactions and release all queued
2193 if (q->start_streaming_called)
2194 call_void_qop(q, stop_streaming, q);
2197 * If you see this warning, then the driver isn't cleaning up properly
2198 * in stop_streaming(). See the stop_streaming() documentation in
2199 * videobuf2-core.h for more information how buffers should be returned
2200 * to vb2 in stop_streaming().
2202 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2203 for (i = 0; i < q->num_buffers; ++i)
2204 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2205 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2206 /* Must be zero now */
2207 WARN_ON(atomic_read(&q->owned_by_drv_count));
2211 q->start_streaming_called = 0;
2212 q->queued_count = 0;
2216 * Remove all buffers from videobuf's list...
2218 INIT_LIST_HEAD(&q->queued_list);
2220 * ...and done list; userspace will not receive any buffers it
2221 * has not already dequeued before initiating cancel.
2223 INIT_LIST_HEAD(&q->done_list);
2224 atomic_set(&q->owned_by_drv_count, 0);
2225 wake_up_all(&q->done_wq);
2228 * Reinitialize all buffers for next use.
2229 * Make sure to call buf_finish for any queued buffers. Normally
2230 * that's done in dqbuf, but that's not going to happen when we
2231 * cancel the whole queue. Note: this code belongs here, not in
2232 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2233 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2234 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2236 for (i = 0; i < q->num_buffers; ++i) {
2237 struct vb2_buffer *vb = q->bufs[i];
2239 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2240 vb->state = VB2_BUF_STATE_PREPARED;
2241 call_void_vb_qop(vb, buf_finish, vb);
2247 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2251 if (type != q->type) {
2252 dprintk(1, "invalid stream type\n");
2257 dprintk(3, "already streaming\n");
2261 if (!q->num_buffers) {
2262 dprintk(1, "no buffers have been allocated\n");
2266 if (q->num_buffers < q->min_buffers_needed) {
2267 dprintk(1, "need at least %u allocated buffers\n",
2268 q->min_buffers_needed);
2273 * Tell driver to start streaming provided sufficient buffers
2276 if (q->queued_count >= q->min_buffers_needed) {
2277 ret = vb2_start_streaming(q);
2279 __vb2_queue_cancel(q);
2286 dprintk(3, "successful\n");
2291 * vb2_queue_error() - signal a fatal error on the queue
2292 * @q: videobuf2 queue
2294 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2295 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2296 * buffers will return -EIO.
2298 * The error flag will be cleared when cancelling the queue, either from
2299 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2300 * function before starting the stream, otherwise the error flag will remain set
2301 * until the queue is released when closing the device node.
2303 void vb2_queue_error(struct vb2_queue *q)
2307 wake_up_all(&q->done_wq);
2309 EXPORT_SYMBOL_GPL(vb2_queue_error);
2312 * vb2_streamon - start streaming
2313 * @q: videobuf2 queue
2314 * @type: type argument passed from userspace to vidioc_streamon handler
2316 * Should be called from vidioc_streamon handler of a driver.
2318 * 1) verifies current state
2319 * 2) passes any previously queued buffers to the driver and starts streaming
2321 * The return values from this function are intended to be directly returned
2322 * from vidioc_streamon handler in the driver.
2324 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2326 if (vb2_fileio_is_active(q)) {
2327 dprintk(1, "file io in progress\n");
2330 return vb2_internal_streamon(q, type);
2332 EXPORT_SYMBOL_GPL(vb2_streamon);
2334 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2336 if (type != q->type) {
2337 dprintk(1, "invalid stream type\n");
2342 * Cancel will pause streaming and remove all buffers from the driver
2343 * and videobuf, effectively returning control over them to userspace.
2345 * Note that we do this even if q->streaming == 0: if you prepare or
2346 * queue buffers, and then call streamoff without ever having called
2347 * streamon, you would still expect those buffers to be returned to
2348 * their normal dequeued state.
2350 __vb2_queue_cancel(q);
2351 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2352 q->last_buffer_dequeued = false;
2354 dprintk(3, "successful\n");
2359 * vb2_streamoff - stop streaming
2360 * @q: videobuf2 queue
2361 * @type: type argument passed from userspace to vidioc_streamoff handler
2363 * Should be called from vidioc_streamoff handler of a driver.
2365 * 1) verifies current state,
2366 * 2) stop streaming and dequeues any queued buffers, including those previously
2367 * passed to the driver (after waiting for the driver to finish).
2369 * This call can be used for pausing playback.
2370 * The return values from this function are intended to be directly returned
2371 * from vidioc_streamoff handler in the driver
2373 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2375 if (vb2_fileio_is_active(q)) {
2376 dprintk(1, "file io in progress\n");
2379 return vb2_internal_streamoff(q, type);
2381 EXPORT_SYMBOL_GPL(vb2_streamoff);
2384 * __find_plane_by_offset() - find plane associated with the given offset off
2386 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2387 unsigned int *_buffer, unsigned int *_plane)
2389 struct vb2_buffer *vb;
2390 unsigned int buffer, plane;
2393 * Go over all buffers and their planes, comparing the given offset
2394 * with an offset assigned to each plane. If a match is found,
2395 * return its buffer and plane numbers.
2397 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2398 vb = q->bufs[buffer];
2400 for (plane = 0; plane < vb->num_planes; ++plane) {
2401 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2413 * vb2_expbuf() - Export a buffer as a file descriptor
2414 * @q: videobuf2 queue
2415 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2418 * The return values from this function are intended to be directly returned
2419 * from vidioc_expbuf handler in driver.
2421 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2423 struct vb2_buffer *vb = NULL;
2424 struct vb2_plane *vb_plane;
2426 struct dma_buf *dbuf;
2428 if (q->memory != V4L2_MEMORY_MMAP) {
2429 dprintk(1, "queue is not currently set up for mmap\n");
2433 if (!q->mem_ops->get_dmabuf) {
2434 dprintk(1, "queue does not support DMA buffer exporting\n");
2438 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2439 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2443 if (eb->type != q->type) {
2444 dprintk(1, "invalid buffer type\n");
2448 if (eb->index >= q->num_buffers) {
2449 dprintk(1, "buffer index out of range\n");
2453 vb = q->bufs[eb->index];
2455 if (eb->plane >= vb->num_planes) {
2456 dprintk(1, "buffer plane out of range\n");
2460 if (vb2_fileio_is_active(q)) {
2461 dprintk(1, "expbuf: file io in progress\n");
2465 vb_plane = &vb->planes[eb->plane];
2467 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2468 if (IS_ERR_OR_NULL(dbuf)) {
2469 dprintk(1, "failed to export buffer %d, plane %d\n",
2470 eb->index, eb->plane);
2474 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2476 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2477 eb->index, eb->plane, ret);
2482 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2483 eb->index, eb->plane, ret);
2488 EXPORT_SYMBOL_GPL(vb2_expbuf);
2491 * vb2_mmap() - map video buffers into application address space
2492 * @q: videobuf2 queue
2493 * @vma: vma passed to the mmap file operation handler in the driver
2495 * Should be called from mmap file operation handler of a driver.
2496 * This function maps one plane of one of the available video buffers to
2497 * userspace. To map whole video memory allocated on reqbufs, this function
2498 * has to be called once per each plane per each buffer previously allocated.
2500 * When the userspace application calls mmap, it passes to it an offset returned
2501 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2502 * a "cookie", which is then used to identify the plane to be mapped.
2503 * This function finds a plane with a matching offset and a mapping is performed
2504 * by the means of a provided memory operation.
2506 * The return values from this function are intended to be directly returned
2507 * from the mmap handler in driver.
2509 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2511 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2512 struct vb2_buffer *vb;
2513 unsigned int buffer = 0, plane = 0;
2515 unsigned long length;
2517 if (q->memory != V4L2_MEMORY_MMAP) {
2518 dprintk(1, "queue is not currently set up for mmap\n");
2523 * Check memory area access mode.
2525 if (!(vma->vm_flags & VM_SHARED)) {
2526 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2529 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2530 if (!(vma->vm_flags & VM_WRITE)) {
2531 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2535 if (!(vma->vm_flags & VM_READ)) {
2536 dprintk(1, "invalid vma flags, VM_READ needed\n");
2540 if (vb2_fileio_is_active(q)) {
2541 dprintk(1, "mmap: file io in progress\n");
2546 * Find the plane corresponding to the offset passed by userspace.
2548 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2552 vb = q->bufs[buffer];
2555 * MMAP requires page_aligned buffers.
2556 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2557 * so, we need to do the same here.
2559 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2560 if (length < (vma->vm_end - vma->vm_start)) {
2562 "MMAP invalid, as it would overflow buffer length\n");
2566 mutex_lock(&q->mmap_lock);
2567 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2568 mutex_unlock(&q->mmap_lock);
2572 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2575 EXPORT_SYMBOL_GPL(vb2_mmap);
2578 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2581 unsigned long pgoff,
2582 unsigned long flags)
2584 unsigned long off = pgoff << PAGE_SHIFT;
2585 struct vb2_buffer *vb;
2586 unsigned int buffer, plane;
2590 if (q->memory != V4L2_MEMORY_MMAP) {
2591 dprintk(1, "queue is not currently set up for mmap\n");
2596 * Find the plane corresponding to the offset passed by userspace.
2598 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2602 vb = q->bufs[buffer];
2604 vaddr = vb2_plane_vaddr(vb, plane);
2605 return vaddr ? (unsigned long)vaddr : -EINVAL;
2607 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2610 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2611 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2614 * vb2_poll() - implements poll userspace operation
2615 * @q: videobuf2 queue
2616 * @file: file argument passed to the poll file operation handler
2617 * @wait: wait argument passed to the poll file operation handler
2619 * This function implements poll file operation handler for a driver.
2620 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2621 * be informed that the file descriptor of a video device is available for
2623 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2624 * will be reported as available for writing.
2626 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2629 * The return values from this function are intended to be directly returned
2630 * from poll handler in driver.
2632 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2634 struct video_device *vfd = video_devdata(file);
2635 unsigned long req_events = poll_requested_events(wait);
2636 struct vb2_buffer *vb = NULL;
2637 unsigned int res = 0;
2638 unsigned long flags;
2640 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2641 struct v4l2_fh *fh = file->private_data;
2643 if (v4l2_event_pending(fh))
2645 else if (req_events & POLLPRI)
2646 poll_wait(file, &fh->wait, wait);
2649 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2651 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2655 * Start file I/O emulator only if streaming API has not been used yet.
2657 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2658 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2659 (req_events & (POLLIN | POLLRDNORM))) {
2660 if (__vb2_init_fileio(q, 1))
2661 return res | POLLERR;
2663 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2664 (req_events & (POLLOUT | POLLWRNORM))) {
2665 if (__vb2_init_fileio(q, 0))
2666 return res | POLLERR;
2668 * Write to OUTPUT queue can be done immediately.
2670 return res | POLLOUT | POLLWRNORM;
2675 * There is nothing to wait for if the queue isn't streaming, or if the
2676 * error flag is set.
2678 if (!vb2_is_streaming(q) || q->error)
2679 return res | POLLERR;
2681 * For compatibility with vb1: if QBUF hasn't been called yet, then
2682 * return POLLERR as well. This only affects capture queues, output
2683 * queues will always initialize waiting_for_buffers to false.
2685 if (q->waiting_for_buffers)
2686 return res | POLLERR;
2689 * For output streams you can write as long as there are fewer buffers
2690 * queued than there are buffers available.
2692 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2693 return res | POLLOUT | POLLWRNORM;
2695 if (list_empty(&q->done_list)) {
2697 * If the last buffer was dequeued from a capture queue,
2698 * return immediately. DQBUF will return -EPIPE.
2700 if (q->last_buffer_dequeued)
2701 return res | POLLIN | POLLRDNORM;
2703 poll_wait(file, &q->done_wq, wait);
2707 * Take first buffer available for dequeuing.
2709 spin_lock_irqsave(&q->done_lock, flags);
2710 if (!list_empty(&q->done_list))
2711 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2713 spin_unlock_irqrestore(&q->done_lock, flags);
2715 if (vb && (vb->state == VB2_BUF_STATE_DONE
2716 || vb->state == VB2_BUF_STATE_ERROR)) {
2717 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2718 res | POLLOUT | POLLWRNORM :
2719 res | POLLIN | POLLRDNORM;
2723 EXPORT_SYMBOL_GPL(vb2_poll);
2726 * vb2_queue_init() - initialize a videobuf2 queue
2727 * @q: videobuf2 queue; this structure should be allocated in driver
2729 * The vb2_queue structure should be allocated by the driver. The driver is
2730 * responsible of clearing it's content and setting initial values for some
2731 * required entries before calling this function.
2732 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2733 * to the struct vb2_queue description in include/media/videobuf2-core.h
2734 * for more information.
2736 int vb2_queue_init(struct vb2_queue *q)
2743 WARN_ON(!q->mem_ops) ||
2744 WARN_ON(!q->type) ||
2745 WARN_ON(!q->io_modes) ||
2746 WARN_ON(!q->ops->queue_setup) ||
2747 WARN_ON(!q->ops->buf_queue) ||
2748 WARN_ON(q->timestamp_flags &
2749 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2750 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2753 /* Warn that the driver should choose an appropriate timestamp type */
2754 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2755 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2757 INIT_LIST_HEAD(&q->queued_list);
2758 INIT_LIST_HEAD(&q->done_list);
2759 spin_lock_init(&q->done_lock);
2760 mutex_init(&q->mmap_lock);
2761 init_waitqueue_head(&q->done_wq);
2763 if (q->buf_struct_size == 0)
2764 q->buf_struct_size = sizeof(struct vb2_buffer);
2768 EXPORT_SYMBOL_GPL(vb2_queue_init);
2771 * vb2_queue_release() - stop streaming, release the queue and free memory
2772 * @q: videobuf2 queue
2774 * This function stops streaming and performs necessary clean ups, including
2775 * freeing video buffer memory. The driver is responsible for freeing
2776 * the vb2_queue structure itself.
2778 void vb2_queue_release(struct vb2_queue *q)
2780 __vb2_cleanup_fileio(q);
2781 __vb2_queue_cancel(q);
2782 mutex_lock(&q->mmap_lock);
2783 __vb2_queue_free(q, q->num_buffers);
2784 mutex_unlock(&q->mmap_lock);
2786 EXPORT_SYMBOL_GPL(vb2_queue_release);
2789 * struct vb2_fileio_buf - buffer context used by file io emulator
2791 * vb2 provides a compatibility layer and emulator of file io (read and
2792 * write) calls on top of streaming API. This structure is used for
2793 * tracking context related to the buffers.
2795 struct vb2_fileio_buf {
2799 unsigned int queued:1;
2803 * struct vb2_fileio_data - queue context used by file io emulator
2805 * @cur_index: the index of the buffer currently being read from or
2806 * written to. If equal to q->num_buffers then a new buffer
2808 * @initial_index: in the read() case all buffers are queued up immediately
2809 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2810 * buffers. However, in the write() case no buffers are initially
2811 * queued, instead whenever a buffer is full it is queued up by
2812 * __vb2_perform_fileio(). Only once all available buffers have
2813 * been queued up will __vb2_perform_fileio() start to dequeue
2814 * buffers. This means that initially __vb2_perform_fileio()
2815 * needs to know what buffer index to use when it is queuing up
2816 * the buffers for the first time. That initial index is stored
2817 * in this field. Once it is equal to q->num_buffers all
2818 * available buffers have been queued and __vb2_perform_fileio()
2819 * should start the normal dequeue/queue cycle.
2821 * vb2 provides a compatibility layer and emulator of file io (read and
2822 * write) calls on top of streaming API. For proper operation it required
2823 * this structure to save the driver state between each call of the read
2824 * or write function.
2826 struct vb2_fileio_data {
2827 struct v4l2_requestbuffers req;
2828 struct v4l2_plane p;
2829 struct v4l2_buffer b;
2830 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2831 unsigned int cur_index;
2832 unsigned int initial_index;
2833 unsigned int q_count;
2834 unsigned int dq_count;
2835 unsigned read_once:1;
2836 unsigned write_immediately:1;
2840 * __vb2_init_fileio() - initialize file io emulator
2841 * @q: videobuf2 queue
2842 * @read: mode selector (1 means read, 0 means write)
2844 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2846 struct vb2_fileio_data *fileio;
2848 unsigned int count = 0;
2853 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2854 (!read && !(q->io_modes & VB2_WRITE))))
2858 * Check if device supports mapping buffers to kernel virtual space.
2860 if (!q->mem_ops->vaddr)
2864 * Check if streaming api has not been already activated.
2866 if (q->streaming || q->num_buffers > 0)
2870 * Start with count 1, driver can increase it in queue_setup()
2874 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2875 (read) ? "read" : "write", count, q->fileio_read_once,
2876 q->fileio_write_immediately);
2878 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2882 fileio->read_once = q->fileio_read_once;
2883 fileio->write_immediately = q->fileio_write_immediately;
2886 * Request buffers and use MMAP type to force driver
2887 * to allocate buffers by itself.
2889 fileio->req.count = count;
2890 fileio->req.memory = V4L2_MEMORY_MMAP;
2891 fileio->req.type = q->type;
2893 ret = __reqbufs(q, &fileio->req);
2898 * Check if plane_count is correct
2899 * (multiplane buffers are not supported).
2901 if (q->bufs[0]->num_planes != 1) {
2907 * Get kernel address of each buffer.
2909 for (i = 0; i < q->num_buffers; i++) {
2910 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2911 if (fileio->bufs[i].vaddr == NULL) {
2915 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2919 * Read mode requires pre queuing of all buffers.
2922 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2925 * Queue all buffers.
2927 for (i = 0; i < q->num_buffers; i++) {
2928 struct v4l2_buffer *b = &fileio->b;
2930 memset(b, 0, sizeof(*b));
2932 if (is_multiplanar) {
2933 memset(&fileio->p, 0, sizeof(fileio->p));
2934 b->m.planes = &fileio->p;
2937 b->memory = q->memory;
2939 ret = vb2_internal_qbuf(q, b);
2942 fileio->bufs[i].queued = 1;
2945 * All buffers have been queued, so mark that by setting
2946 * initial_index to q->num_buffers
2948 fileio->initial_index = q->num_buffers;
2949 fileio->cur_index = q->num_buffers;
2955 ret = vb2_internal_streamon(q, q->type);
2962 fileio->req.count = 0;
2963 __reqbufs(q, &fileio->req);
2972 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2973 * @q: videobuf2 queue
2975 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2977 struct vb2_fileio_data *fileio = q->fileio;
2980 vb2_internal_streamoff(q, q->type);
2982 fileio->req.count = 0;
2983 vb2_reqbufs(q, &fileio->req);
2985 dprintk(3, "file io emulator closed\n");
2991 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2992 * @q: videobuf2 queue
2993 * @data: pointed to target userspace buffer
2994 * @count: number of bytes to read or write
2995 * @ppos: file handle position tracking pointer
2996 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2997 * @read: access mode selector (1 means read, 0 means write)
2999 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
3000 loff_t *ppos, int nonblock, int read)
3002 struct vb2_fileio_data *fileio;
3003 struct vb2_fileio_buf *buf;
3004 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
3006 * When using write() to write data to an output video node the vb2 core
3007 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
3008 * else is able to provide this information with the write() operation.
3010 bool set_timestamp = !read &&
3011 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3012 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3015 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
3016 read ? "read" : "write", (long)*ppos, count,
3017 nonblock ? "non" : "");
3023 * Initialize emulator on first call.
3025 if (!vb2_fileio_is_active(q)) {
3026 ret = __vb2_init_fileio(q, read);
3027 dprintk(3, "vb2_init_fileio result: %d\n", ret);
3034 * Check if we need to dequeue the buffer.
3036 index = fileio->cur_index;
3037 if (index >= q->num_buffers) {
3039 * Call vb2_dqbuf to get buffer back.
3041 memset(&fileio->b, 0, sizeof(fileio->b));
3042 fileio->b.type = q->type;
3043 fileio->b.memory = q->memory;
3044 if (is_multiplanar) {
3045 memset(&fileio->p, 0, sizeof(fileio->p));
3046 fileio->b.m.planes = &fileio->p;
3047 fileio->b.length = 1;
3049 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
3050 dprintk(5, "vb2_dqbuf result: %d\n", ret);
3053 fileio->dq_count += 1;
3055 fileio->cur_index = index = fileio->b.index;
3056 buf = &fileio->bufs[index];
3059 * Get number of bytes filled by the driver
3063 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
3064 : vb2_plane_size(q->bufs[index], 0);
3065 /* Compensate for data_offset on read in the multiplanar case. */
3066 if (is_multiplanar && read &&
3067 fileio->b.m.planes[0].data_offset < buf->size) {
3068 buf->pos = fileio->b.m.planes[0].data_offset;
3069 buf->size -= buf->pos;
3072 buf = &fileio->bufs[index];
3076 * Limit count on last few bytes of the buffer.
3078 if (buf->pos + count > buf->size) {
3079 count = buf->size - buf->pos;
3080 dprintk(5, "reducing read count: %zd\n", count);
3084 * Transfer data to userspace.
3086 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3087 count, index, buf->pos);
3089 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3091 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3093 dprintk(3, "error copying data\n");
3104 * Queue next buffer if required.
3106 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
3108 * Check if this is the last buffer to read.
3110 if (read && fileio->read_once && fileio->dq_count == 1) {
3111 dprintk(3, "read limit reached\n");
3112 return __vb2_cleanup_fileio(q);
3116 * Call vb2_qbuf and give buffer to the driver.
3118 memset(&fileio->b, 0, sizeof(fileio->b));
3119 fileio->b.type = q->type;
3120 fileio->b.memory = q->memory;
3121 fileio->b.index = index;
3122 fileio->b.bytesused = buf->pos;
3123 if (is_multiplanar) {
3124 memset(&fileio->p, 0, sizeof(fileio->p));
3125 fileio->p.bytesused = buf->pos;
3126 fileio->b.m.planes = &fileio->p;
3127 fileio->b.length = 1;
3130 v4l2_get_timestamp(&fileio->b.timestamp);
3131 ret = vb2_internal_qbuf(q, &fileio->b);
3132 dprintk(5, "vb2_dbuf result: %d\n", ret);
3137 * Buffer has been queued, update the status
3141 buf->size = vb2_plane_size(q->bufs[index], 0);
3142 fileio->q_count += 1;
3144 * If we are queuing up buffers for the first time, then
3145 * increase initial_index by one.
3147 if (fileio->initial_index < q->num_buffers)
3148 fileio->initial_index++;
3150 * The next buffer to use is either a buffer that's going to be
3151 * queued for the first time (initial_index < q->num_buffers)
3152 * or it is equal to q->num_buffers, meaning that the next
3153 * time we need to dequeue a buffer since we've now queued up
3154 * all the 'first time' buffers.
3156 fileio->cur_index = fileio->initial_index;
3160 * Return proper number of bytes processed.
3167 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3168 loff_t *ppos, int nonblocking)
3170 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3172 EXPORT_SYMBOL_GPL(vb2_read);
3174 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3175 loff_t *ppos, int nonblocking)
3177 return __vb2_perform_fileio(q, (char __user *) data, count,
3178 ppos, nonblocking, 0);
3180 EXPORT_SYMBOL_GPL(vb2_write);
3182 struct vb2_threadio_data {
3183 struct task_struct *thread;
3189 static int vb2_thread(void *data)
3191 struct vb2_queue *q = data;
3192 struct vb2_threadio_data *threadio = q->threadio;
3193 struct vb2_fileio_data *fileio = q->fileio;
3194 bool set_timestamp = false;
3199 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3200 prequeue = q->num_buffers;
3202 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3203 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3209 struct vb2_buffer *vb;
3212 * Call vb2_dqbuf to get buffer back.
3214 memset(&fileio->b, 0, sizeof(fileio->b));
3215 fileio->b.type = q->type;
3216 fileio->b.memory = q->memory;
3218 fileio->b.index = index++;
3221 call_void_qop(q, wait_finish, q);
3222 if (!threadio->stop)
3223 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3224 call_void_qop(q, wait_prepare, q);
3225 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3227 if (ret || threadio->stop)
3231 vb = q->bufs[fileio->b.index];
3232 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3233 if (threadio->fnc(vb, threadio->priv))
3235 call_void_qop(q, wait_finish, q);
3237 v4l2_get_timestamp(&fileio->b.timestamp);
3238 if (!threadio->stop)
3239 ret = vb2_internal_qbuf(q, &fileio->b);
3240 call_void_qop(q, wait_prepare, q);
3241 if (ret || threadio->stop)
3245 /* Hmm, linux becomes *very* unhappy without this ... */
3246 while (!kthread_should_stop()) {
3247 set_current_state(TASK_INTERRUPTIBLE);
3254 * This function should not be used for anything else but the videobuf2-dvb
3255 * support. If you think you have another good use-case for this, then please
3256 * contact the linux-media mailinglist first.
3258 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3259 const char *thread_name)
3261 struct vb2_threadio_data *threadio;
3268 if (WARN_ON(q->fileio))
3271 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3272 if (threadio == NULL)
3274 threadio->fnc = fnc;
3275 threadio->priv = priv;
3277 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3278 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3281 q->threadio = threadio;
3282 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3283 if (IS_ERR(threadio->thread)) {
3284 ret = PTR_ERR(threadio->thread);
3285 threadio->thread = NULL;
3291 __vb2_cleanup_fileio(q);
3296 EXPORT_SYMBOL_GPL(vb2_thread_start);
3298 int vb2_thread_stop(struct vb2_queue *q)
3300 struct vb2_threadio_data *threadio = q->threadio;
3303 if (threadio == NULL)
3305 threadio->stop = true;
3306 /* Wake up all pending sleeps in the thread */
3308 err = kthread_stop(threadio->thread);
3309 __vb2_cleanup_fileio(q);
3310 threadio->thread = NULL;
3315 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3318 * The following functions are not part of the vb2 core API, but are helper
3319 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3320 * and struct vb2_ops.
3321 * They contain boilerplate code that most if not all drivers have to do
3322 * and so they simplify the driver code.
3325 /* The queue is busy if there is a owner and you are not that owner. */
3326 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3328 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3331 /* vb2 ioctl helpers */
3333 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3334 struct v4l2_requestbuffers *p)
3336 struct video_device *vdev = video_devdata(file);
3337 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3341 if (vb2_queue_is_busy(vdev, file))
3343 res = __reqbufs(vdev->queue, p);
3344 /* If count == 0, then the owner has released all buffers and he
3345 is no longer owner of the queue. Otherwise we have a new owner. */
3347 vdev->queue->owner = p->count ? file->private_data : NULL;
3350 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3352 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3353 struct v4l2_create_buffers *p)
3355 struct video_device *vdev = video_devdata(file);
3356 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3358 p->index = vdev->queue->num_buffers;
3359 /* If count == 0, then just check if memory and type are valid.
3360 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3362 return res != -EBUSY ? res : 0;
3365 if (vb2_queue_is_busy(vdev, file))
3367 res = __create_bufs(vdev->queue, p);
3369 vdev->queue->owner = file->private_data;
3372 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3374 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3375 struct v4l2_buffer *p)
3377 struct video_device *vdev = video_devdata(file);
3379 if (vb2_queue_is_busy(vdev, file))
3381 return vb2_prepare_buf(vdev->queue, p);
3383 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3385 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3387 struct video_device *vdev = video_devdata(file);
3389 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3390 return vb2_querybuf(vdev->queue, p);
3392 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3394 int vb2_ioctl_qbuf(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_qbuf(vdev->queue, p);
3402 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3404 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3406 struct video_device *vdev = video_devdata(file);
3408 if (vb2_queue_is_busy(vdev, file))
3410 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3412 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3414 int vb2_ioctl_streamon(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_streamon(vdev->queue, i);
3422 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3424 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3426 struct video_device *vdev = video_devdata(file);
3428 if (vb2_queue_is_busy(vdev, file))
3430 return vb2_streamoff(vdev->queue, i);
3432 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3434 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3436 struct video_device *vdev = video_devdata(file);
3438 if (vb2_queue_is_busy(vdev, file))
3440 return vb2_expbuf(vdev->queue, p);
3442 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3444 /* v4l2_file_operations helpers */
3446 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3448 struct video_device *vdev = video_devdata(file);
3450 return vb2_mmap(vdev->queue, vma);
3452 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3454 int _vb2_fop_release(struct file *file, struct mutex *lock)
3456 struct video_device *vdev = video_devdata(file);
3460 if (file->private_data == vdev->queue->owner) {
3461 vb2_queue_release(vdev->queue);
3462 vdev->queue->owner = NULL;
3466 return v4l2_fh_release(file);
3468 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3470 int vb2_fop_release(struct file *file)
3472 struct video_device *vdev = video_devdata(file);
3473 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3475 return _vb2_fop_release(file, lock);
3477 EXPORT_SYMBOL_GPL(vb2_fop_release);
3479 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3480 size_t count, loff_t *ppos)
3482 struct video_device *vdev = video_devdata(file);
3483 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3486 if (!(vdev->queue->io_modes & VB2_WRITE))
3488 if (lock && mutex_lock_interruptible(lock))
3489 return -ERESTARTSYS;
3490 if (vb2_queue_is_busy(vdev, file))
3492 err = vb2_write(vdev->queue, buf, count, ppos,
3493 file->f_flags & O_NONBLOCK);
3494 if (vdev->queue->fileio)
3495 vdev->queue->owner = file->private_data;
3501 EXPORT_SYMBOL_GPL(vb2_fop_write);
3503 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3504 size_t count, loff_t *ppos)
3506 struct video_device *vdev = video_devdata(file);
3507 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3510 if (!(vdev->queue->io_modes & VB2_READ))
3512 if (lock && mutex_lock_interruptible(lock))
3513 return -ERESTARTSYS;
3514 if (vb2_queue_is_busy(vdev, file))
3516 err = vb2_read(vdev->queue, buf, count, ppos,
3517 file->f_flags & O_NONBLOCK);
3518 if (vdev->queue->fileio)
3519 vdev->queue->owner = file->private_data;
3525 EXPORT_SYMBOL_GPL(vb2_fop_read);
3527 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3529 struct video_device *vdev = video_devdata(file);
3530 struct vb2_queue *q = vdev->queue;
3531 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3536 * If this helper doesn't know how to lock, then you shouldn't be using
3537 * it but you should write your own.
3541 if (lock && mutex_lock_interruptible(lock))
3546 res = vb2_poll(vdev->queue, file, wait);
3548 /* If fileio was started, then we have a new queue owner. */
3549 if (!fileio && q->fileio)
3550 q->owner = file->private_data;
3555 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3558 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3559 unsigned long len, unsigned long pgoff, unsigned long flags)
3561 struct video_device *vdev = video_devdata(file);
3563 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3565 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3568 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3570 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3572 mutex_unlock(vq->lock);
3574 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3576 void vb2_ops_wait_finish(struct vb2_queue *vq)
3578 mutex_lock(vq->lock);
3580 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3582 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3583 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3584 MODULE_LICENSE("GPL");