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>
33 #include <trace/events/v4l2.h>
36 module_param(debug, int, 0644);
38 #define dprintk(level, fmt, arg...) \
41 pr_info("vb2: %s: " fmt, __func__, ## arg); \
44 #ifdef CONFIG_VIDEO_ADV_DEBUG
47 * If advanced debugging is on, then count how often each op is called
48 * successfully, which can either be per-buffer or per-queue.
50 * This makes it easy to check that the 'init' and 'cleanup'
51 * (and variations thereof) stay balanced.
54 #define log_memop(vb, op) \
55 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
56 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
57 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
59 #define call_memop(vb, op, args...) \
61 struct vb2_queue *_q = (vb)->vb2_queue; \
65 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
67 (vb)->cnt_mem_ ## op++; \
71 #define call_ptr_memop(vb, op, args...) \
73 struct vb2_queue *_q = (vb)->vb2_queue; \
77 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
78 if (!IS_ERR_OR_NULL(ptr)) \
79 (vb)->cnt_mem_ ## op++; \
83 #define call_void_memop(vb, op, args...) \
85 struct vb2_queue *_q = (vb)->vb2_queue; \
88 if (_q->mem_ops->op) \
89 _q->mem_ops->op(args); \
90 (vb)->cnt_mem_ ## op++; \
93 #define log_qop(q, op) \
94 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
95 (q)->ops->op ? "" : " (nop)")
97 #define call_qop(q, op, args...) \
102 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
108 #define call_void_qop(q, op, args...) \
112 (q)->ops->op(args); \
116 #define log_vb_qop(vb, op, args...) \
117 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
118 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
119 (vb)->vb2_queue->ops->op ? "" : " (nop)")
121 #define call_vb_qop(vb, op, args...) \
125 log_vb_qop(vb, op); \
126 err = (vb)->vb2_queue->ops->op ? \
127 (vb)->vb2_queue->ops->op(args) : 0; \
129 (vb)->cnt_ ## op++; \
133 #define call_void_vb_qop(vb, op, args...) \
135 log_vb_qop(vb, op); \
136 if ((vb)->vb2_queue->ops->op) \
137 (vb)->vb2_queue->ops->op(args); \
138 (vb)->cnt_ ## op++; \
143 #define call_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : 0)
147 #define call_ptr_memop(vb, op, args...) \
148 ((vb)->vb2_queue->mem_ops->op ? \
149 (vb)->vb2_queue->mem_ops->op(args) : NULL)
151 #define call_void_memop(vb, op, args...) \
153 if ((vb)->vb2_queue->mem_ops->op) \
154 (vb)->vb2_queue->mem_ops->op(args); \
157 #define call_qop(q, op, args...) \
158 ((q)->ops->op ? (q)->ops->op(args) : 0)
160 #define call_void_qop(q, op, args...) \
163 (q)->ops->op(args); \
166 #define call_vb_qop(vb, op, args...) \
167 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
169 #define call_void_vb_qop(vb, op, args...) \
171 if ((vb)->vb2_queue->ops->op) \
172 (vb)->vb2_queue->ops->op(args); \
177 /* Flags that are set by the vb2 core */
178 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
179 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
180 V4L2_BUF_FLAG_PREPARED | \
181 V4L2_BUF_FLAG_TIMESTAMP_MASK)
182 /* Output buffer flags that should be passed on to the driver */
183 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
184 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
186 static void __vb2_queue_cancel(struct vb2_queue *q);
187 static void __enqueue_in_driver(struct vb2_buffer *vb);
190 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
192 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
194 struct vb2_queue *q = vb->vb2_queue;
195 enum dma_data_direction dma_dir =
196 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
201 * Allocate memory for all planes in this buffer
202 * NOTE: mmapped areas should be page aligned
204 for (plane = 0; plane < vb->num_planes; ++plane) {
205 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
207 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
208 size, dma_dir, q->gfp_flags);
209 if (IS_ERR_OR_NULL(mem_priv))
212 /* Associate allocator private data with this plane */
213 vb->planes[plane].mem_priv = mem_priv;
214 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
219 /* Free already allocated memory if one of the allocations failed */
220 for (; plane > 0; --plane) {
221 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
222 vb->planes[plane - 1].mem_priv = NULL;
229 * __vb2_buf_mem_free() - free memory of the given buffer
231 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
235 for (plane = 0; plane < vb->num_planes; ++plane) {
236 call_void_memop(vb, put, vb->planes[plane].mem_priv);
237 vb->planes[plane].mem_priv = NULL;
238 dprintk(3, "freed plane %d of buffer %d\n", plane,
244 * __vb2_buf_userptr_put() - release userspace memory associated with
247 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
251 for (plane = 0; plane < vb->num_planes; ++plane) {
252 if (vb->planes[plane].mem_priv)
253 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
254 vb->planes[plane].mem_priv = NULL;
259 * __vb2_plane_dmabuf_put() - release memory associated with
260 * a DMABUF shared plane
262 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
268 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
270 call_void_memop(vb, detach_dmabuf, p->mem_priv);
271 dma_buf_put(p->dbuf);
272 memset(p, 0, sizeof(*p));
276 * __vb2_buf_dmabuf_put() - release memory associated with
277 * a DMABUF shared buffer
279 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
283 for (plane = 0; plane < vb->num_planes; ++plane)
284 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
288 * __setup_lengths() - setup initial lengths for every plane in
289 * every buffer on the queue
291 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
293 unsigned int buffer, plane;
294 struct vb2_buffer *vb;
296 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
297 vb = q->bufs[buffer];
301 for (plane = 0; plane < vb->num_planes; ++plane)
302 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
307 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
308 * every buffer on the queue
310 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
312 unsigned int buffer, plane;
313 struct vb2_buffer *vb;
316 if (q->num_buffers) {
317 struct v4l2_plane *p;
318 vb = q->bufs[q->num_buffers - 1];
319 p = &vb->v4l2_planes[vb->num_planes - 1];
320 off = PAGE_ALIGN(p->m.mem_offset + p->length);
325 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
326 vb = q->bufs[buffer];
330 for (plane = 0; plane < vb->num_planes; ++plane) {
331 vb->v4l2_planes[plane].m.mem_offset = off;
333 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
336 off += vb->v4l2_planes[plane].length;
337 off = PAGE_ALIGN(off);
343 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
344 * video buffer memory for all buffers/planes on the queue and initializes the
347 * Returns the number of buffers successfully allocated.
349 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
350 unsigned int num_buffers, unsigned int num_planes)
353 struct vb2_buffer *vb;
356 for (buffer = 0; buffer < num_buffers; ++buffer) {
357 /* Allocate videobuf buffer structures */
358 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
360 dprintk(1, "memory alloc for buffer struct failed\n");
364 /* Length stores number of planes for multiplanar buffers */
365 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
366 vb->v4l2_buf.length = num_planes;
368 vb->state = VB2_BUF_STATE_DEQUEUED;
370 vb->num_planes = num_planes;
371 vb->v4l2_buf.index = q->num_buffers + buffer;
372 vb->v4l2_buf.type = q->type;
373 vb->v4l2_buf.memory = memory;
375 /* Allocate video buffer memory for the MMAP type */
376 if (memory == V4L2_MEMORY_MMAP) {
377 ret = __vb2_buf_mem_alloc(vb);
379 dprintk(1, "failed allocating memory for "
380 "buffer %d\n", buffer);
385 * Call the driver-provided buffer initialization
386 * callback, if given. An error in initialization
387 * results in queue setup failure.
389 ret = call_vb_qop(vb, buf_init, vb);
391 dprintk(1, "buffer %d %p initialization"
392 " failed\n", buffer, vb);
393 __vb2_buf_mem_free(vb);
399 q->bufs[q->num_buffers + buffer] = vb;
402 __setup_lengths(q, buffer);
403 if (memory == V4L2_MEMORY_MMAP)
404 __setup_offsets(q, buffer);
406 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
413 * __vb2_free_mem() - release all video buffer memory for a given queue
415 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
418 struct vb2_buffer *vb;
420 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
422 vb = q->bufs[buffer];
426 /* Free MMAP buffers or release USERPTR buffers */
427 if (q->memory == V4L2_MEMORY_MMAP)
428 __vb2_buf_mem_free(vb);
429 else if (q->memory == V4L2_MEMORY_DMABUF)
430 __vb2_buf_dmabuf_put(vb);
432 __vb2_buf_userptr_put(vb);
437 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
438 * related information, if no buffers are left return the queue to an
439 * uninitialized state. Might be called even if the queue has already been freed.
441 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
446 * Sanity check: when preparing a buffer the queue lock is released for
447 * a short while (see __buf_prepare for the details), which would allow
448 * a race with a reqbufs which can call this function. Removing the
449 * buffers from underneath __buf_prepare is obviously a bad idea, so we
450 * check if any of the buffers is in the state PREPARING, and if so we
451 * just return -EAGAIN.
453 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
455 if (q->bufs[buffer] == NULL)
457 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
458 dprintk(1, "preparing buffers, cannot free\n");
463 /* Call driver-provided cleanup function for each buffer, if provided */
464 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
466 struct vb2_buffer *vb = q->bufs[buffer];
468 if (vb && vb->planes[0].mem_priv)
469 call_void_vb_qop(vb, buf_cleanup, vb);
472 /* Release video buffer memory */
473 __vb2_free_mem(q, buffers);
475 #ifdef CONFIG_VIDEO_ADV_DEBUG
477 * Check that all the calls were balances during the life-time of this
478 * queue. If not (or if the debug level is 1 or up), then dump the
479 * counters to the kernel log.
481 if (q->num_buffers) {
482 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
483 q->cnt_wait_prepare != q->cnt_wait_finish;
485 if (unbalanced || debug) {
486 pr_info("vb2: counters for queue %p:%s\n", q,
487 unbalanced ? " UNBALANCED!" : "");
488 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
489 q->cnt_queue_setup, q->cnt_start_streaming,
490 q->cnt_stop_streaming);
491 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
492 q->cnt_wait_prepare, q->cnt_wait_finish);
494 q->cnt_queue_setup = 0;
495 q->cnt_wait_prepare = 0;
496 q->cnt_wait_finish = 0;
497 q->cnt_start_streaming = 0;
498 q->cnt_stop_streaming = 0;
500 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
501 struct vb2_buffer *vb = q->bufs[buffer];
502 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
503 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
504 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
505 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
506 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
507 vb->cnt_buf_queue != vb->cnt_buf_done ||
508 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
509 vb->cnt_buf_init != vb->cnt_buf_cleanup;
511 if (unbalanced || debug) {
512 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
513 q, buffer, unbalanced ? " UNBALANCED!" : "");
514 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
515 vb->cnt_buf_init, vb->cnt_buf_cleanup,
516 vb->cnt_buf_prepare, vb->cnt_buf_finish);
517 pr_info("vb2: buf_queue: %u buf_done: %u\n",
518 vb->cnt_buf_queue, vb->cnt_buf_done);
519 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
520 vb->cnt_mem_alloc, vb->cnt_mem_put,
521 vb->cnt_mem_prepare, vb->cnt_mem_finish,
523 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
524 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
525 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
526 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
527 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
528 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
529 vb->cnt_mem_get_dmabuf,
530 vb->cnt_mem_num_users,
537 /* Free videobuf buffers */
538 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
540 kfree(q->bufs[buffer]);
541 q->bufs[buffer] = NULL;
544 q->num_buffers -= buffers;
545 if (!q->num_buffers) {
547 INIT_LIST_HEAD(&q->queued_list);
553 * __verify_planes_array() - verify that the planes array passed in struct
554 * v4l2_buffer from userspace can be safely used
556 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
558 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
561 /* Is memory for copying plane information present? */
562 if (NULL == b->m.planes) {
563 dprintk(1, "multi-planar buffer passed but "
564 "planes array not provided\n");
568 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
569 dprintk(1, "incorrect planes array length, "
570 "expected %d, got %d\n", vb->num_planes, b->length);
578 * __verify_length() - Verify that the bytesused value for each plane fits in
579 * the plane length and that the data offset doesn't exceed the bytesused value.
581 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
584 unsigned int bytesused;
587 if (!V4L2_TYPE_IS_OUTPUT(b->type))
590 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
591 for (plane = 0; plane < vb->num_planes; ++plane) {
592 length = (b->memory == V4L2_MEMORY_USERPTR ||
593 b->memory == V4L2_MEMORY_DMABUF)
594 ? b->m.planes[plane].length
595 : vb->v4l2_planes[plane].length;
596 bytesused = b->m.planes[plane].bytesused
597 ? b->m.planes[plane].bytesused : length;
599 if (b->m.planes[plane].bytesused > length)
602 if (b->m.planes[plane].data_offset > 0 &&
603 b->m.planes[plane].data_offset >= bytesused)
607 length = (b->memory == V4L2_MEMORY_USERPTR)
608 ? b->length : vb->v4l2_planes[0].length;
609 bytesused = b->bytesused ? b->bytesused : length;
611 if (b->bytesused > length)
619 * __buffer_in_use() - return true if the buffer is in use and
620 * the queue cannot be freed (by the means of REQBUFS(0)) call
622 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
625 for (plane = 0; plane < vb->num_planes; ++plane) {
626 void *mem_priv = vb->planes[plane].mem_priv;
628 * If num_users() has not been provided, call_memop
629 * will return 0, apparently nobody cares about this
630 * case anyway. If num_users() returns more than 1,
631 * we are not the only user of the plane's memory.
633 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
640 * __buffers_in_use() - return true if any buffers on the queue are in use and
641 * the queue cannot be freed (by the means of REQBUFS(0)) call
643 static bool __buffers_in_use(struct vb2_queue *q)
646 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
647 if (__buffer_in_use(q, q->bufs[buffer]))
654 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
655 * returned to userspace
657 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
659 struct vb2_queue *q = vb->vb2_queue;
661 /* Copy back data such as timestamp, flags, etc. */
662 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
663 b->reserved2 = vb->v4l2_buf.reserved2;
664 b->reserved = vb->v4l2_buf.reserved;
666 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
668 * Fill in plane-related data if userspace provided an array
669 * for it. The caller has already verified memory and size.
671 b->length = vb->num_planes;
672 memcpy(b->m.planes, vb->v4l2_planes,
673 b->length * sizeof(struct v4l2_plane));
676 * We use length and offset in v4l2_planes array even for
677 * single-planar buffers, but userspace does not.
679 b->length = vb->v4l2_planes[0].length;
680 b->bytesused = vb->v4l2_planes[0].bytesused;
681 if (q->memory == V4L2_MEMORY_MMAP)
682 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
683 else if (q->memory == V4L2_MEMORY_USERPTR)
684 b->m.userptr = vb->v4l2_planes[0].m.userptr;
685 else if (q->memory == V4L2_MEMORY_DMABUF)
686 b->m.fd = vb->v4l2_planes[0].m.fd;
690 * Clear any buffer state related flags.
692 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
693 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
694 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
695 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
697 * For non-COPY timestamps, drop timestamp source bits
698 * and obtain the timestamp source from the queue.
700 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
701 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
705 case VB2_BUF_STATE_QUEUED:
706 case VB2_BUF_STATE_ACTIVE:
707 b->flags |= V4L2_BUF_FLAG_QUEUED;
709 case VB2_BUF_STATE_ERROR:
710 b->flags |= V4L2_BUF_FLAG_ERROR;
712 case VB2_BUF_STATE_DONE:
713 b->flags |= V4L2_BUF_FLAG_DONE;
715 case VB2_BUF_STATE_PREPARED:
716 b->flags |= V4L2_BUF_FLAG_PREPARED;
718 case VB2_BUF_STATE_PREPARING:
719 case VB2_BUF_STATE_DEQUEUED:
720 case VB2_BUF_STATE_REQUEUEING:
725 if (__buffer_in_use(q, vb))
726 b->flags |= V4L2_BUF_FLAG_MAPPED;
730 * vb2_querybuf() - query video buffer information
732 * @b: buffer struct passed from userspace to vidioc_querybuf handler
735 * Should be called from vidioc_querybuf ioctl handler in driver.
736 * This function will verify the passed v4l2_buffer structure and fill the
737 * relevant information for the userspace.
739 * The return values from this function are intended to be directly returned
740 * from vidioc_querybuf handler in driver.
742 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
744 struct vb2_buffer *vb;
747 if (b->type != q->type) {
748 dprintk(1, "wrong buffer type\n");
752 if (b->index >= q->num_buffers) {
753 dprintk(1, "buffer index out of range\n");
756 vb = q->bufs[b->index];
757 ret = __verify_planes_array(vb, b);
759 __fill_v4l2_buffer(vb, b);
762 EXPORT_SYMBOL(vb2_querybuf);
765 * __verify_userptr_ops() - verify that all memory operations required for
766 * USERPTR queue type have been provided
768 static int __verify_userptr_ops(struct vb2_queue *q)
770 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
771 !q->mem_ops->put_userptr)
778 * __verify_mmap_ops() - verify that all memory operations required for
779 * MMAP queue type have been provided
781 static int __verify_mmap_ops(struct vb2_queue *q)
783 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
784 !q->mem_ops->put || !q->mem_ops->mmap)
791 * __verify_dmabuf_ops() - verify that all memory operations required for
792 * DMABUF queue type have been provided
794 static int __verify_dmabuf_ops(struct vb2_queue *q)
796 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
797 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
798 !q->mem_ops->unmap_dmabuf)
805 * __verify_memory_type() - Check whether the memory type and buffer type
806 * passed to a buffer operation are compatible with the queue.
808 static int __verify_memory_type(struct vb2_queue *q,
809 enum v4l2_memory memory, enum v4l2_buf_type type)
811 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
812 memory != V4L2_MEMORY_DMABUF) {
813 dprintk(1, "unsupported memory type\n");
817 if (type != q->type) {
818 dprintk(1, "requested type is incorrect\n");
823 * Make sure all the required memory ops for given memory type
826 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
827 dprintk(1, "MMAP for current setup unsupported\n");
831 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
832 dprintk(1, "USERPTR for current setup unsupported\n");
836 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
837 dprintk(1, "DMABUF for current setup unsupported\n");
842 * Place the busy tests at the end: -EBUSY can be ignored when
843 * create_bufs is called with count == 0, but count == 0 should still
844 * do the memory and type validation.
846 if (vb2_fileio_is_active(q)) {
847 dprintk(1, "file io in progress\n");
854 * __reqbufs() - Initiate streaming
855 * @q: videobuf2 queue
856 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
858 * Should be called from vidioc_reqbufs ioctl handler of a driver.
860 * 1) verifies streaming parameters passed from the userspace,
861 * 2) sets up the queue,
862 * 3) negotiates number of buffers and planes per buffer with the driver
863 * to be used during streaming,
864 * 4) allocates internal buffer structures (struct vb2_buffer), according to
865 * the agreed parameters,
866 * 5) for MMAP memory type, allocates actual video memory, using the
867 * memory handling/allocation routines provided during queue initialization
869 * If req->count is 0, all the memory will be freed instead.
870 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
871 * and the queue is not busy, memory will be reallocated.
873 * The return values from this function are intended to be directly returned
874 * from vidioc_reqbufs handler in driver.
876 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
878 unsigned int num_buffers, allocated_buffers, num_planes = 0;
882 dprintk(1, "streaming active\n");
886 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
888 * We already have buffers allocated, so first check if they
889 * are not in use and can be freed.
891 mutex_lock(&q->mmap_lock);
892 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
893 mutex_unlock(&q->mmap_lock);
894 dprintk(1, "memory in use, cannot free\n");
899 * Call queue_cancel to clean up any buffers in the PREPARED or
900 * QUEUED state which is possible if buffers were prepared or
901 * queued without ever calling STREAMON.
903 __vb2_queue_cancel(q);
904 ret = __vb2_queue_free(q, q->num_buffers);
905 mutex_unlock(&q->mmap_lock);
910 * In case of REQBUFS(0) return immediately without calling
911 * driver's queue_setup() callback and allocating resources.
918 * Make sure the requested values and current defaults are sane.
920 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
921 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
922 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
923 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
924 q->memory = req->memory;
927 * Ask the driver how many buffers and planes per buffer it requires.
928 * Driver also sets the size and allocator context for each plane.
930 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
931 q->plane_sizes, q->alloc_ctx);
935 /* Finally, allocate buffers and video memory */
936 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
937 if (allocated_buffers == 0) {
938 dprintk(1, "memory allocation failed\n");
943 * There is no point in continuing if we can't allocate the minimum
944 * number of buffers needed by this vb2_queue.
946 if (allocated_buffers < q->min_buffers_needed)
950 * Check if driver can handle the allocated number of buffers.
952 if (!ret && allocated_buffers < num_buffers) {
953 num_buffers = allocated_buffers;
955 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
956 &num_planes, q->plane_sizes, q->alloc_ctx);
958 if (!ret && allocated_buffers < num_buffers)
962 * Either the driver has accepted a smaller number of buffers,
963 * or .queue_setup() returned an error
967 mutex_lock(&q->mmap_lock);
968 q->num_buffers = allocated_buffers;
972 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
973 * from q->num_buffers.
975 __vb2_queue_free(q, allocated_buffers);
976 mutex_unlock(&q->mmap_lock);
979 mutex_unlock(&q->mmap_lock);
982 * Return the number of successfully allocated buffers
985 req->count = allocated_buffers;
986 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
992 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
994 * @q: videobuf2 queue
995 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
997 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
999 int ret = __verify_memory_type(q, req->memory, req->type);
1001 return ret ? ret : __reqbufs(q, req);
1003 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1006 * __create_bufs() - Allocate buffers and any required auxiliary structs
1007 * @q: videobuf2 queue
1008 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1011 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1013 * 1) verifies parameter sanity
1014 * 2) calls the .queue_setup() queue operation
1015 * 3) performs any necessary memory allocations
1017 * The return values from this function are intended to be directly returned
1018 * from vidioc_create_bufs handler in driver.
1020 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1022 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1025 if (q->num_buffers == VIDEO_MAX_FRAME) {
1026 dprintk(1, "maximum number of buffers already allocated\n");
1030 if (!q->num_buffers) {
1031 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1032 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1033 q->memory = create->memory;
1034 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1037 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1040 * Ask the driver, whether the requested number of buffers, planes per
1041 * buffer and their sizes are acceptable
1043 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1044 &num_planes, q->plane_sizes, q->alloc_ctx);
1048 /* Finally, allocate buffers and video memory */
1049 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1051 if (allocated_buffers == 0) {
1052 dprintk(1, "memory allocation failed\n");
1057 * Check if driver can handle the so far allocated number of buffers.
1059 if (allocated_buffers < num_buffers) {
1060 num_buffers = allocated_buffers;
1063 * q->num_buffers contains the total number of buffers, that the
1064 * queue driver has set up
1066 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1067 &num_planes, q->plane_sizes, q->alloc_ctx);
1069 if (!ret && allocated_buffers < num_buffers)
1073 * Either the driver has accepted a smaller number of buffers,
1074 * or .queue_setup() returned an error
1078 mutex_lock(&q->mmap_lock);
1079 q->num_buffers += allocated_buffers;
1083 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1084 * from q->num_buffers.
1086 __vb2_queue_free(q, allocated_buffers);
1087 mutex_unlock(&q->mmap_lock);
1090 mutex_unlock(&q->mmap_lock);
1093 * Return the number of successfully allocated buffers
1096 create->count = allocated_buffers;
1102 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1103 * memory and type values.
1104 * @q: videobuf2 queue
1105 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1108 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1110 int ret = __verify_memory_type(q, create->memory, create->format.type);
1112 create->index = q->num_buffers;
1113 if (create->count == 0)
1114 return ret != -EBUSY ? ret : 0;
1115 return ret ? ret : __create_bufs(q, create);
1117 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1120 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1121 * @vb: vb2_buffer to which the plane in question belongs to
1122 * @plane_no: plane number for which the address is to be returned
1124 * This function returns a kernel virtual address of a given plane if
1125 * such a mapping exist, NULL otherwise.
1127 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1129 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1132 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1135 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1138 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1139 * @vb: vb2_buffer to which the plane in question belongs to
1140 * @plane_no: plane number for which the cookie is to be returned
1142 * This function returns an allocator specific cookie for a given plane if
1143 * available, NULL otherwise. The allocator should provide some simple static
1144 * inline function, which would convert this cookie to the allocator specific
1145 * type that can be used directly by the driver to access the buffer. This can
1146 * be for example physical address, pointer to scatter list or IOMMU mapping.
1148 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1150 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1153 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1155 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1158 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1159 * @vb: vb2_buffer returned from the driver
1160 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1161 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1162 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1163 * If start_streaming fails then it should return buffers with state
1164 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1166 * This function should be called by the driver after a hardware operation on
1167 * a buffer is finished and the buffer may be returned to userspace. The driver
1168 * cannot use this buffer anymore until it is queued back to it by videobuf
1169 * by the means of buf_queue callback. Only buffers previously queued to the
1170 * driver by buf_queue can be passed to this function.
1172 * While streaming a buffer can only be returned in state DONE or ERROR.
1173 * The start_streaming op can also return them in case the DMA engine cannot
1174 * be started for some reason. In that case the buffers should be returned with
1177 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1179 struct vb2_queue *q = vb->vb2_queue;
1180 unsigned long flags;
1183 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1186 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1187 state != VB2_BUF_STATE_ERROR &&
1188 state != VB2_BUF_STATE_QUEUED &&
1189 state != VB2_BUF_STATE_REQUEUEING))
1190 state = VB2_BUF_STATE_ERROR;
1192 #ifdef CONFIG_VIDEO_ADV_DEBUG
1194 * Although this is not a callback, it still does have to balance
1195 * with the buf_queue op. So update this counter manually.
1199 dprintk(4, "done processing on buffer %d, state: %d\n",
1200 vb->v4l2_buf.index, state);
1203 for (plane = 0; plane < vb->num_planes; ++plane)
1204 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1206 spin_lock_irqsave(&q->done_lock, flags);
1207 if (state == VB2_BUF_STATE_QUEUED ||
1208 state == VB2_BUF_STATE_REQUEUEING) {
1209 vb->state = VB2_BUF_STATE_QUEUED;
1211 /* Add the buffer to the done buffers list */
1212 list_add_tail(&vb->done_entry, &q->done_list);
1215 atomic_dec(&q->owned_by_drv_count);
1216 spin_unlock_irqrestore(&q->done_lock, flags);
1218 trace_vb2_buf_done(q, vb);
1221 case VB2_BUF_STATE_QUEUED:
1223 case VB2_BUF_STATE_REQUEUEING:
1224 if (q->start_streaming_called)
1225 __enqueue_in_driver(vb);
1228 /* Inform any processes that may be waiting for buffers */
1229 wake_up(&q->done_wq);
1233 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1236 * vb2_discard_done() - discard all buffers marked as DONE
1237 * @q: videobuf2 queue
1239 * This function is intended to be used with suspend/resume operations. It
1240 * discards all 'done' buffers as they would be too old to be requested after
1243 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1244 * delayed works before calling this function to make sure no buffer will be
1245 * touched by the driver and/or hardware.
1247 void vb2_discard_done(struct vb2_queue *q)
1249 struct vb2_buffer *vb;
1250 unsigned long flags;
1252 spin_lock_irqsave(&q->done_lock, flags);
1253 list_for_each_entry(vb, &q->done_list, done_entry)
1254 vb->state = VB2_BUF_STATE_ERROR;
1255 spin_unlock_irqrestore(&q->done_lock, flags);
1257 EXPORT_SYMBOL_GPL(vb2_discard_done);
1259 static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
1261 static bool check_once;
1269 pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1270 if (vb->vb2_queue->allow_zero_bytesused)
1271 pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1273 pr_warn("use the actual size instead.\n");
1277 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1278 * v4l2_buffer by the userspace. The caller has already verified that struct
1279 * v4l2_buffer has a valid number of planes.
1281 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1282 struct v4l2_plane *v4l2_planes)
1286 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1287 if (b->memory == V4L2_MEMORY_USERPTR) {
1288 for (plane = 0; plane < vb->num_planes; ++plane) {
1289 v4l2_planes[plane].m.userptr =
1290 b->m.planes[plane].m.userptr;
1291 v4l2_planes[plane].length =
1292 b->m.planes[plane].length;
1295 if (b->memory == V4L2_MEMORY_DMABUF) {
1296 for (plane = 0; plane < vb->num_planes; ++plane) {
1297 v4l2_planes[plane].m.fd =
1298 b->m.planes[plane].m.fd;
1299 v4l2_planes[plane].length =
1300 b->m.planes[plane].length;
1304 /* Fill in driver-provided information for OUTPUT types */
1305 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1307 * Will have to go up to b->length when API starts
1308 * accepting variable number of planes.
1310 * If bytesused == 0 for the output buffer, then fall
1311 * back to the full buffer size. In that case
1312 * userspace clearly never bothered to set it and
1313 * it's a safe assumption that they really meant to
1314 * use the full plane sizes.
1316 * Some drivers, e.g. old codec drivers, use bytesused == 0
1317 * as a way to indicate that streaming is finished.
1318 * In that case, the driver should use the
1319 * allow_zero_bytesused flag to keep old userspace
1320 * applications working.
1322 for (plane = 0; plane < vb->num_planes; ++plane) {
1323 struct v4l2_plane *pdst = &v4l2_planes[plane];
1324 struct v4l2_plane *psrc = &b->m.planes[plane];
1326 if (psrc->bytesused == 0)
1327 vb2_warn_zero_bytesused(vb);
1329 if (vb->vb2_queue->allow_zero_bytesused)
1330 pdst->bytesused = psrc->bytesused;
1332 pdst->bytesused = psrc->bytesused ?
1333 psrc->bytesused : pdst->length;
1334 pdst->data_offset = psrc->data_offset;
1339 * Single-planar buffers do not use planes array,
1340 * so fill in relevant v4l2_buffer struct fields instead.
1341 * In videobuf we use our internal V4l2_planes struct for
1342 * single-planar buffers as well, for simplicity.
1344 * If bytesused == 0 for the output buffer, then fall back
1345 * to the full buffer size as that's a sensible default.
1347 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1348 * a way to indicate that streaming is finished. In that case,
1349 * the driver should use the allow_zero_bytesused flag to keep
1350 * old userspace applications working.
1352 if (b->memory == V4L2_MEMORY_USERPTR) {
1353 v4l2_planes[0].m.userptr = b->m.userptr;
1354 v4l2_planes[0].length = b->length;
1357 if (b->memory == V4L2_MEMORY_DMABUF) {
1358 v4l2_planes[0].m.fd = b->m.fd;
1359 v4l2_planes[0].length = b->length;
1362 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1363 if (b->bytesused == 0)
1364 vb2_warn_zero_bytesused(vb);
1366 if (vb->vb2_queue->allow_zero_bytesused)
1367 v4l2_planes[0].bytesused = b->bytesused;
1369 v4l2_planes[0].bytesused = b->bytesused ?
1370 b->bytesused : v4l2_planes[0].length;
1372 v4l2_planes[0].bytesused = 0;
1376 /* Zero flags that the vb2 core handles */
1377 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1378 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1379 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1381 * Non-COPY timestamps and non-OUTPUT queues will get
1382 * their timestamp and timestamp source flags from the
1385 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1388 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1390 * For output buffers mask out the timecode flag:
1391 * this will be handled later in vb2_internal_qbuf().
1392 * The 'field' is valid metadata for this output buffer
1393 * and so that needs to be copied here.
1395 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1396 vb->v4l2_buf.field = b->field;
1398 /* Zero any output buffer flags as this is a capture buffer */
1399 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1404 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1406 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1408 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1409 return call_vb_qop(vb, buf_prepare, vb);
1413 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1415 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1417 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1418 struct vb2_queue *q = vb->vb2_queue;
1422 enum dma_data_direction dma_dir =
1423 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1424 bool reacquired = vb->planes[0].mem_priv == NULL;
1426 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1427 /* Copy relevant information provided by the userspace */
1428 __fill_vb2_buffer(vb, b, planes);
1430 for (plane = 0; plane < vb->num_planes; ++plane) {
1431 /* Skip the plane if already verified */
1432 if (vb->v4l2_planes[plane].m.userptr &&
1433 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1434 && vb->v4l2_planes[plane].length == planes[plane].length)
1437 dprintk(3, "userspace address for plane %d changed, "
1438 "reacquiring memory\n", plane);
1440 /* Check if the provided plane buffer is large enough */
1441 if (planes[plane].length < q->plane_sizes[plane]) {
1442 dprintk(1, "provided buffer size %u is less than "
1443 "setup size %u for plane %d\n",
1444 planes[plane].length,
1445 q->plane_sizes[plane], plane);
1450 /* Release previously acquired memory if present */
1451 if (vb->planes[plane].mem_priv) {
1454 call_void_vb_qop(vb, buf_cleanup, vb);
1456 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1459 vb->planes[plane].mem_priv = NULL;
1460 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1462 /* Acquire each plane's memory */
1463 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1464 planes[plane].m.userptr,
1465 planes[plane].length, dma_dir);
1466 if (IS_ERR_OR_NULL(mem_priv)) {
1467 dprintk(1, "failed acquiring userspace "
1468 "memory for plane %d\n", plane);
1469 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1472 vb->planes[plane].mem_priv = mem_priv;
1476 * Now that everything is in order, copy relevant information
1477 * provided by userspace.
1479 for (plane = 0; plane < vb->num_planes; ++plane)
1480 vb->v4l2_planes[plane] = planes[plane];
1484 * One or more planes changed, so we must call buf_init to do
1485 * the driver-specific initialization on the newly acquired
1486 * buffer, if provided.
1488 ret = call_vb_qop(vb, buf_init, vb);
1490 dprintk(1, "buffer initialization failed\n");
1495 ret = call_vb_qop(vb, buf_prepare, vb);
1497 dprintk(1, "buffer preparation failed\n");
1498 call_void_vb_qop(vb, buf_cleanup, vb);
1504 /* In case of errors, release planes that were already acquired */
1505 for (plane = 0; plane < vb->num_planes; ++plane) {
1506 if (vb->planes[plane].mem_priv)
1507 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1508 vb->planes[plane].mem_priv = NULL;
1509 vb->v4l2_planes[plane].m.userptr = 0;
1510 vb->v4l2_planes[plane].length = 0;
1517 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1519 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1521 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1522 struct vb2_queue *q = vb->vb2_queue;
1526 enum dma_data_direction dma_dir =
1527 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1528 bool reacquired = vb->planes[0].mem_priv == NULL;
1530 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1531 /* Copy relevant information provided by the userspace */
1532 __fill_vb2_buffer(vb, b, planes);
1534 for (plane = 0; plane < vb->num_planes; ++plane) {
1535 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1537 if (IS_ERR_OR_NULL(dbuf)) {
1538 dprintk(1, "invalid dmabuf fd for plane %d\n",
1544 /* use DMABUF size if length is not provided */
1545 if (planes[plane].length == 0)
1546 planes[plane].length = dbuf->size;
1548 if (planes[plane].length < q->plane_sizes[plane]) {
1549 dprintk(1, "invalid dmabuf length for plane %d\n",
1555 /* Skip the plane if already verified */
1556 if (dbuf == vb->planes[plane].dbuf &&
1557 vb->v4l2_planes[plane].length == planes[plane].length) {
1562 dprintk(1, "buffer for plane %d changed\n", plane);
1566 call_void_vb_qop(vb, buf_cleanup, vb);
1569 /* Release previously acquired memory if present */
1570 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1571 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1573 /* Acquire each plane's memory */
1574 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1575 dbuf, planes[plane].length, dma_dir);
1576 if (IS_ERR(mem_priv)) {
1577 dprintk(1, "failed to attach dmabuf\n");
1578 ret = PTR_ERR(mem_priv);
1583 vb->planes[plane].dbuf = dbuf;
1584 vb->planes[plane].mem_priv = mem_priv;
1587 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1588 * really we want to do this just before the DMA, not while queueing
1591 for (plane = 0; plane < vb->num_planes; ++plane) {
1592 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1594 dprintk(1, "failed to map dmabuf for plane %d\n",
1598 vb->planes[plane].dbuf_mapped = 1;
1602 * Now that everything is in order, copy relevant information
1603 * provided by userspace.
1605 for (plane = 0; plane < vb->num_planes; ++plane)
1606 vb->v4l2_planes[plane] = planes[plane];
1610 * Call driver-specific initialization on the newly acquired buffer,
1613 ret = call_vb_qop(vb, buf_init, vb);
1615 dprintk(1, "buffer initialization failed\n");
1620 ret = call_vb_qop(vb, buf_prepare, vb);
1622 dprintk(1, "buffer preparation failed\n");
1623 call_void_vb_qop(vb, buf_cleanup, vb);
1629 /* In case of errors, release planes that were already acquired */
1630 __vb2_buf_dmabuf_put(vb);
1636 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1638 static void __enqueue_in_driver(struct vb2_buffer *vb)
1640 struct vb2_queue *q = vb->vb2_queue;
1643 vb->state = VB2_BUF_STATE_ACTIVE;
1644 atomic_inc(&q->owned_by_drv_count);
1646 trace_vb2_buf_queue(q, vb);
1649 for (plane = 0; plane < vb->num_planes; ++plane)
1650 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1652 call_void_vb_qop(vb, buf_queue, vb);
1655 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1657 struct vb2_queue *q = vb->vb2_queue;
1660 ret = __verify_length(vb, b);
1662 dprintk(1, "plane parameters verification failed: %d\n", ret);
1665 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1667 * If the format's field is ALTERNATE, then the buffer's field
1668 * should be either TOP or BOTTOM, not ALTERNATE since that
1669 * makes no sense. The driver has to know whether the
1670 * buffer represents a top or a bottom field in order to
1671 * program any DMA correctly. Using ALTERNATE is wrong, since
1672 * that just says that it is either a top or a bottom field,
1673 * but not which of the two it is.
1675 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1680 dprintk(1, "fatal error occurred on queue\n");
1684 vb->state = VB2_BUF_STATE_PREPARING;
1685 vb->v4l2_buf.timestamp.tv_sec = 0;
1686 vb->v4l2_buf.timestamp.tv_usec = 0;
1687 vb->v4l2_buf.sequence = 0;
1689 switch (q->memory) {
1690 case V4L2_MEMORY_MMAP:
1691 ret = __qbuf_mmap(vb, b);
1693 case V4L2_MEMORY_USERPTR:
1694 ret = __qbuf_userptr(vb, b);
1696 case V4L2_MEMORY_DMABUF:
1697 ret = __qbuf_dmabuf(vb, b);
1700 WARN(1, "Invalid queue type\n");
1705 dprintk(1, "buffer preparation failed: %d\n", ret);
1706 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1711 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1714 if (b->type != q->type) {
1715 dprintk(1, "%s: invalid buffer type\n", opname);
1719 if (b->index >= q->num_buffers) {
1720 dprintk(1, "%s: buffer index out of range\n", opname);
1724 if (q->bufs[b->index] == NULL) {
1725 /* Should never happen */
1726 dprintk(1, "%s: buffer is NULL\n", opname);
1730 if (b->memory != q->memory) {
1731 dprintk(1, "%s: invalid memory type\n", opname);
1735 return __verify_planes_array(q->bufs[b->index], b);
1739 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1740 * @q: videobuf2 queue
1741 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1744 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1746 * 1) verifies the passed buffer,
1747 * 2) calls buf_prepare callback in the driver (if provided), in which
1748 * driver-specific buffer initialization can be performed,
1750 * The return values from this function are intended to be directly returned
1751 * from vidioc_prepare_buf handler in driver.
1753 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1755 struct vb2_buffer *vb;
1758 if (vb2_fileio_is_active(q)) {
1759 dprintk(1, "file io in progress\n");
1763 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1767 vb = q->bufs[b->index];
1768 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1769 dprintk(1, "invalid buffer state %d\n",
1774 ret = __buf_prepare(vb, b);
1776 /* Fill buffer information for the userspace */
1777 __fill_v4l2_buffer(vb, b);
1779 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1783 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1786 * vb2_start_streaming() - Attempt to start streaming.
1787 * @q: videobuf2 queue
1789 * Attempt to start streaming. When this function is called there must be
1790 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1791 * number of buffers required for the DMA engine to function). If the
1792 * @start_streaming op fails it is supposed to return all the driver-owned
1793 * buffers back to vb2 in state QUEUED. Check if that happened and if
1794 * not warn and reclaim them forcefully.
1796 static int vb2_start_streaming(struct vb2_queue *q)
1798 struct vb2_buffer *vb;
1802 * If any buffers were queued before streamon,
1803 * we can now pass them to driver for processing.
1805 list_for_each_entry(vb, &q->queued_list, queued_entry)
1806 __enqueue_in_driver(vb);
1808 /* Tell the driver to start streaming */
1809 q->start_streaming_called = 1;
1810 ret = call_qop(q, start_streaming, q,
1811 atomic_read(&q->owned_by_drv_count));
1815 q->start_streaming_called = 0;
1817 dprintk(1, "driver refused to start streaming\n");
1819 * If you see this warning, then the driver isn't cleaning up properly
1820 * after a failed start_streaming(). See the start_streaming()
1821 * documentation in videobuf2-core.h for more information how buffers
1822 * should be returned to vb2 in start_streaming().
1824 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1828 * Forcefully reclaim buffers if the driver did not
1829 * correctly return them to vb2.
1831 for (i = 0; i < q->num_buffers; ++i) {
1833 if (vb->state == VB2_BUF_STATE_ACTIVE)
1834 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1836 /* Must be zero now */
1837 WARN_ON(atomic_read(&q->owned_by_drv_count));
1840 * If done_list is not empty, then start_streaming() didn't call
1841 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1844 WARN_ON(!list_empty(&q->done_list));
1848 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1850 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1851 struct vb2_buffer *vb;
1856 vb = q->bufs[b->index];
1858 switch (vb->state) {
1859 case VB2_BUF_STATE_DEQUEUED:
1860 ret = __buf_prepare(vb, b);
1864 case VB2_BUF_STATE_PREPARED:
1866 case VB2_BUF_STATE_PREPARING:
1867 dprintk(1, "buffer still being prepared\n");
1870 dprintk(1, "invalid buffer state %d\n", vb->state);
1875 * Add to the queued buffers list, a buffer will stay on it until
1876 * dequeued in dqbuf.
1878 list_add_tail(&vb->queued_entry, &q->queued_list);
1880 q->waiting_for_buffers = false;
1881 vb->state = VB2_BUF_STATE_QUEUED;
1882 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1884 * For output buffers copy the timestamp if needed,
1885 * and the timecode field and flag if needed.
1887 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1888 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1889 vb->v4l2_buf.timestamp = b->timestamp;
1890 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1891 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1892 vb->v4l2_buf.timecode = b->timecode;
1895 trace_vb2_qbuf(q, vb);
1898 * If already streaming, give the buffer to driver for processing.
1899 * If not, the buffer will be given to driver on next streamon.
1901 if (q->start_streaming_called)
1902 __enqueue_in_driver(vb);
1904 /* Fill buffer information for the userspace */
1905 __fill_v4l2_buffer(vb, b);
1908 * If streamon has been called, and we haven't yet called
1909 * start_streaming() since not enough buffers were queued, and
1910 * we now have reached the minimum number of queued buffers,
1911 * then we can finally call start_streaming().
1913 if (q->streaming && !q->start_streaming_called &&
1914 q->queued_count >= q->min_buffers_needed) {
1915 ret = vb2_start_streaming(q);
1920 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1925 * vb2_qbuf() - Queue a buffer from userspace
1926 * @q: videobuf2 queue
1927 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1930 * Should be called from vidioc_qbuf ioctl handler of a driver.
1932 * 1) verifies the passed buffer,
1933 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1934 * which driver-specific buffer initialization can be performed,
1935 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1936 * callback for processing.
1938 * The return values from this function are intended to be directly returned
1939 * from vidioc_qbuf handler in driver.
1941 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1943 if (vb2_fileio_is_active(q)) {
1944 dprintk(1, "file io in progress\n");
1948 return vb2_internal_qbuf(q, b);
1950 EXPORT_SYMBOL_GPL(vb2_qbuf);
1953 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1956 * Will sleep if required for nonblocking == false.
1958 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1961 * All operations on vb_done_list are performed under done_lock
1962 * spinlock protection. However, buffers may be removed from
1963 * it and returned to userspace only while holding both driver's
1964 * lock and the done_lock spinlock. Thus we can be sure that as
1965 * long as we hold the driver's lock, the list will remain not
1966 * empty if list_empty() check succeeds.
1972 if (!q->streaming) {
1973 dprintk(1, "streaming off, will not wait for buffers\n");
1978 dprintk(1, "Queue in error state, will not wait for buffers\n");
1982 if (q->last_buffer_dequeued) {
1983 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1987 if (!list_empty(&q->done_list)) {
1989 * Found a buffer that we were waiting for.
1995 dprintk(1, "nonblocking and no buffers to dequeue, "
2001 * We are streaming and blocking, wait for another buffer to
2002 * become ready or for streamoff. Driver's lock is released to
2003 * allow streamoff or qbuf to be called while waiting.
2005 call_void_qop(q, wait_prepare, q);
2008 * All locks have been released, it is safe to sleep now.
2010 dprintk(3, "will sleep waiting for buffers\n");
2011 ret = wait_event_interruptible(q->done_wq,
2012 !list_empty(&q->done_list) || !q->streaming ||
2016 * We need to reevaluate both conditions again after reacquiring
2017 * the locks or return an error if one occurred.
2019 call_void_qop(q, wait_finish, q);
2021 dprintk(1, "sleep was interrupted\n");
2029 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2031 * Will sleep if required for nonblocking == false.
2033 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
2034 struct v4l2_buffer *b, int nonblocking)
2036 unsigned long flags;
2040 * Wait for at least one buffer to become available on the done_list.
2042 ret = __vb2_wait_for_done_vb(q, nonblocking);
2047 * Driver's lock has been held since we last verified that done_list
2048 * is not empty, so no need for another list_empty(done_list) check.
2050 spin_lock_irqsave(&q->done_lock, flags);
2051 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
2053 * Only remove the buffer from done_list if v4l2_buffer can handle all
2056 ret = __verify_planes_array(*vb, b);
2058 list_del(&(*vb)->done_entry);
2059 spin_unlock_irqrestore(&q->done_lock, flags);
2065 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2066 * @q: videobuf2 queue
2068 * This function will wait until all buffers that have been given to the driver
2069 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2070 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2071 * taken, for example from stop_streaming() callback.
2073 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2075 if (!q->streaming) {
2076 dprintk(1, "streaming off, will not wait for buffers\n");
2080 if (q->start_streaming_called)
2081 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2084 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2087 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2089 static void __vb2_dqbuf(struct vb2_buffer *vb)
2091 struct vb2_queue *q = vb->vb2_queue;
2094 /* nothing to do if the buffer is already dequeued */
2095 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2098 vb->state = VB2_BUF_STATE_DEQUEUED;
2100 /* unmap DMABUF buffer */
2101 if (q->memory == V4L2_MEMORY_DMABUF)
2102 for (i = 0; i < vb->num_planes; ++i) {
2103 if (!vb->planes[i].dbuf_mapped)
2105 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2106 vb->planes[i].dbuf_mapped = 0;
2110 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2112 struct vb2_buffer *vb = NULL;
2115 if (b->type != q->type) {
2116 dprintk(1, "invalid buffer type\n");
2119 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2123 switch (vb->state) {
2124 case VB2_BUF_STATE_DONE:
2125 dprintk(3, "returning done buffer\n");
2127 case VB2_BUF_STATE_ERROR:
2128 dprintk(3, "returning done buffer with errors\n");
2131 dprintk(1, "invalid buffer state\n");
2135 call_void_vb_qop(vb, buf_finish, vb);
2137 /* Fill buffer information for the userspace */
2138 __fill_v4l2_buffer(vb, b);
2139 /* Remove from videobuf queue */
2140 list_del(&vb->queued_entry);
2143 trace_vb2_dqbuf(q, vb);
2145 if (!V4L2_TYPE_IS_OUTPUT(q->type) &&
2146 vb->v4l2_buf.flags & V4L2_BUF_FLAG_LAST)
2147 q->last_buffer_dequeued = true;
2148 /* go back to dequeued state */
2151 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2152 vb->v4l2_buf.index, vb->state);
2158 * vb2_dqbuf() - Dequeue a buffer to the userspace
2159 * @q: videobuf2 queue
2160 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2162 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2163 * buffers ready for dequeuing are present. Normally the driver
2164 * would be passing (file->f_flags & O_NONBLOCK) here
2166 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2168 * 1) verifies the passed buffer,
2169 * 2) calls buf_finish callback in the driver (if provided), in which
2170 * driver can perform any additional operations that may be required before
2171 * returning the buffer to userspace, such as cache sync,
2172 * 3) the buffer struct members are filled with relevant information for
2175 * The return values from this function are intended to be directly returned
2176 * from vidioc_dqbuf handler in driver.
2178 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2180 if (vb2_fileio_is_active(q)) {
2181 dprintk(1, "file io in progress\n");
2184 return vb2_internal_dqbuf(q, b, nonblocking);
2186 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2189 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2191 * Removes all queued buffers from driver's queue and all buffers queued by
2192 * userspace from videobuf's queue. Returns to state after reqbufs.
2194 static void __vb2_queue_cancel(struct vb2_queue *q)
2199 * Tell driver to stop all transactions and release all queued
2202 if (q->start_streaming_called)
2203 call_void_qop(q, stop_streaming, q);
2206 * If you see this warning, then the driver isn't cleaning up properly
2207 * in stop_streaming(). See the stop_streaming() documentation in
2208 * videobuf2-core.h for more information how buffers should be returned
2209 * to vb2 in stop_streaming().
2211 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2212 for (i = 0; i < q->num_buffers; ++i)
2213 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2214 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2215 /* Must be zero now */
2216 WARN_ON(atomic_read(&q->owned_by_drv_count));
2220 q->start_streaming_called = 0;
2221 q->queued_count = 0;
2225 * Remove all buffers from videobuf's list...
2227 INIT_LIST_HEAD(&q->queued_list);
2229 * ...and done list; userspace will not receive any buffers it
2230 * has not already dequeued before initiating cancel.
2232 INIT_LIST_HEAD(&q->done_list);
2233 atomic_set(&q->owned_by_drv_count, 0);
2234 wake_up_all(&q->done_wq);
2237 * Reinitialize all buffers for next use.
2238 * Make sure to call buf_finish for any queued buffers. Normally
2239 * that's done in dqbuf, but that's not going to happen when we
2240 * cancel the whole queue. Note: this code belongs here, not in
2241 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2242 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2243 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2245 for (i = 0; i < q->num_buffers; ++i) {
2246 struct vb2_buffer *vb = q->bufs[i];
2248 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2249 vb->state = VB2_BUF_STATE_PREPARED;
2250 call_void_vb_qop(vb, buf_finish, vb);
2256 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2260 if (type != q->type) {
2261 dprintk(1, "invalid stream type\n");
2266 dprintk(3, "already streaming\n");
2270 if (!q->num_buffers) {
2271 dprintk(1, "no buffers have been allocated\n");
2275 if (q->num_buffers < q->min_buffers_needed) {
2276 dprintk(1, "need at least %u allocated buffers\n",
2277 q->min_buffers_needed);
2282 * Tell driver to start streaming provided sufficient buffers
2285 if (q->queued_count >= q->min_buffers_needed) {
2286 ret = vb2_start_streaming(q);
2288 __vb2_queue_cancel(q);
2295 dprintk(3, "successful\n");
2300 * vb2_queue_error() - signal a fatal error on the queue
2301 * @q: videobuf2 queue
2303 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2304 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2305 * buffers will return -EIO.
2307 * The error flag will be cleared when cancelling the queue, either from
2308 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2309 * function before starting the stream, otherwise the error flag will remain set
2310 * until the queue is released when closing the device node.
2312 void vb2_queue_error(struct vb2_queue *q)
2316 wake_up_all(&q->done_wq);
2318 EXPORT_SYMBOL_GPL(vb2_queue_error);
2321 * vb2_streamon - start streaming
2322 * @q: videobuf2 queue
2323 * @type: type argument passed from userspace to vidioc_streamon handler
2325 * Should be called from vidioc_streamon handler of a driver.
2327 * 1) verifies current state
2328 * 2) passes any previously queued buffers to the driver and starts streaming
2330 * The return values from this function are intended to be directly returned
2331 * from vidioc_streamon handler in the driver.
2333 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2335 if (vb2_fileio_is_active(q)) {
2336 dprintk(1, "file io in progress\n");
2339 return vb2_internal_streamon(q, type);
2341 EXPORT_SYMBOL_GPL(vb2_streamon);
2343 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2345 if (type != q->type) {
2346 dprintk(1, "invalid stream type\n");
2351 * Cancel will pause streaming and remove all buffers from the driver
2352 * and videobuf, effectively returning control over them to userspace.
2354 * Note that we do this even if q->streaming == 0: if you prepare or
2355 * queue buffers, and then call streamoff without ever having called
2356 * streamon, you would still expect those buffers to be returned to
2357 * their normal dequeued state.
2359 __vb2_queue_cancel(q);
2360 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2361 q->last_buffer_dequeued = false;
2363 dprintk(3, "successful\n");
2368 * vb2_streamoff - stop streaming
2369 * @q: videobuf2 queue
2370 * @type: type argument passed from userspace to vidioc_streamoff handler
2372 * Should be called from vidioc_streamoff handler of a driver.
2374 * 1) verifies current state,
2375 * 2) stop streaming and dequeues any queued buffers, including those previously
2376 * passed to the driver (after waiting for the driver to finish).
2378 * This call can be used for pausing playback.
2379 * The return values from this function are intended to be directly returned
2380 * from vidioc_streamoff handler in the driver
2382 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2384 if (vb2_fileio_is_active(q)) {
2385 dprintk(1, "file io in progress\n");
2388 return vb2_internal_streamoff(q, type);
2390 EXPORT_SYMBOL_GPL(vb2_streamoff);
2393 * __find_plane_by_offset() - find plane associated with the given offset off
2395 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2396 unsigned int *_buffer, unsigned int *_plane)
2398 struct vb2_buffer *vb;
2399 unsigned int buffer, plane;
2402 * Go over all buffers and their planes, comparing the given offset
2403 * with an offset assigned to each plane. If a match is found,
2404 * return its buffer and plane numbers.
2406 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2407 vb = q->bufs[buffer];
2409 for (plane = 0; plane < vb->num_planes; ++plane) {
2410 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2422 * vb2_expbuf() - Export a buffer as a file descriptor
2423 * @q: videobuf2 queue
2424 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2427 * The return values from this function are intended to be directly returned
2428 * from vidioc_expbuf handler in driver.
2430 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2432 struct vb2_buffer *vb = NULL;
2433 struct vb2_plane *vb_plane;
2435 struct dma_buf *dbuf;
2437 if (q->memory != V4L2_MEMORY_MMAP) {
2438 dprintk(1, "queue is not currently set up for mmap\n");
2442 if (!q->mem_ops->get_dmabuf) {
2443 dprintk(1, "queue does not support DMA buffer exporting\n");
2447 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2448 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2452 if (eb->type != q->type) {
2453 dprintk(1, "invalid buffer type\n");
2457 if (eb->index >= q->num_buffers) {
2458 dprintk(1, "buffer index out of range\n");
2462 vb = q->bufs[eb->index];
2464 if (eb->plane >= vb->num_planes) {
2465 dprintk(1, "buffer plane out of range\n");
2469 if (vb2_fileio_is_active(q)) {
2470 dprintk(1, "expbuf: file io in progress\n");
2474 vb_plane = &vb->planes[eb->plane];
2476 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2477 if (IS_ERR_OR_NULL(dbuf)) {
2478 dprintk(1, "failed to export buffer %d, plane %d\n",
2479 eb->index, eb->plane);
2483 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2485 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2486 eb->index, eb->plane, ret);
2491 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2492 eb->index, eb->plane, ret);
2497 EXPORT_SYMBOL_GPL(vb2_expbuf);
2500 * vb2_mmap() - map video buffers into application address space
2501 * @q: videobuf2 queue
2502 * @vma: vma passed to the mmap file operation handler in the driver
2504 * Should be called from mmap file operation handler of a driver.
2505 * This function maps one plane of one of the available video buffers to
2506 * userspace. To map whole video memory allocated on reqbufs, this function
2507 * has to be called once per each plane per each buffer previously allocated.
2509 * When the userspace application calls mmap, it passes to it an offset returned
2510 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2511 * a "cookie", which is then used to identify the plane to be mapped.
2512 * This function finds a plane with a matching offset and a mapping is performed
2513 * by the means of a provided memory operation.
2515 * The return values from this function are intended to be directly returned
2516 * from the mmap handler in driver.
2518 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2520 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2521 struct vb2_buffer *vb;
2522 unsigned int buffer = 0, plane = 0;
2524 unsigned long length;
2526 if (q->memory != V4L2_MEMORY_MMAP) {
2527 dprintk(1, "queue is not currently set up for mmap\n");
2532 * Check memory area access mode.
2534 if (!(vma->vm_flags & VM_SHARED)) {
2535 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2538 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2539 if (!(vma->vm_flags & VM_WRITE)) {
2540 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2544 if (!(vma->vm_flags & VM_READ)) {
2545 dprintk(1, "invalid vma flags, VM_READ needed\n");
2549 if (vb2_fileio_is_active(q)) {
2550 dprintk(1, "mmap: file io in progress\n");
2555 * Find the plane corresponding to the offset passed by userspace.
2557 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2561 vb = q->bufs[buffer];
2564 * MMAP requires page_aligned buffers.
2565 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2566 * so, we need to do the same here.
2568 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2569 if (length < (vma->vm_end - vma->vm_start)) {
2571 "MMAP invalid, as it would overflow buffer length\n");
2575 mutex_lock(&q->mmap_lock);
2576 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2577 mutex_unlock(&q->mmap_lock);
2581 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2584 EXPORT_SYMBOL_GPL(vb2_mmap);
2587 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2590 unsigned long pgoff,
2591 unsigned long flags)
2593 unsigned long off = pgoff << PAGE_SHIFT;
2594 struct vb2_buffer *vb;
2595 unsigned int buffer, plane;
2599 if (q->memory != V4L2_MEMORY_MMAP) {
2600 dprintk(1, "queue is not currently set up for mmap\n");
2605 * Find the plane corresponding to the offset passed by userspace.
2607 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2611 vb = q->bufs[buffer];
2613 vaddr = vb2_plane_vaddr(vb, plane);
2614 return vaddr ? (unsigned long)vaddr : -EINVAL;
2616 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2619 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2620 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2623 * vb2_poll() - implements poll userspace operation
2624 * @q: videobuf2 queue
2625 * @file: file argument passed to the poll file operation handler
2626 * @wait: wait argument passed to the poll file operation handler
2628 * This function implements poll file operation handler for a driver.
2629 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2630 * be informed that the file descriptor of a video device is available for
2632 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2633 * will be reported as available for writing.
2635 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2638 * The return values from this function are intended to be directly returned
2639 * from poll handler in driver.
2641 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2643 struct video_device *vfd = video_devdata(file);
2644 unsigned long req_events = poll_requested_events(wait);
2645 struct vb2_buffer *vb = NULL;
2646 unsigned int res = 0;
2647 unsigned long flags;
2649 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2650 struct v4l2_fh *fh = file->private_data;
2652 if (v4l2_event_pending(fh))
2654 else if (req_events & POLLPRI)
2655 poll_wait(file, &fh->wait, wait);
2658 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2660 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2664 * Start file I/O emulator only if streaming API has not been used yet.
2666 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2667 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2668 (req_events & (POLLIN | POLLRDNORM))) {
2669 if (__vb2_init_fileio(q, 1))
2670 return res | POLLERR;
2672 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2673 (req_events & (POLLOUT | POLLWRNORM))) {
2674 if (__vb2_init_fileio(q, 0))
2675 return res | POLLERR;
2677 * Write to OUTPUT queue can be done immediately.
2679 return res | POLLOUT | POLLWRNORM;
2684 * There is nothing to wait for if the queue isn't streaming, or if the
2685 * error flag is set.
2687 if (!vb2_is_streaming(q) || q->error)
2688 return res | POLLERR;
2690 * For compatibility with vb1: if QBUF hasn't been called yet, then
2691 * return POLLERR as well. This only affects capture queues, output
2692 * queues will always initialize waiting_for_buffers to false.
2694 if (q->waiting_for_buffers)
2695 return res | POLLERR;
2698 * For output streams you can write as long as there are fewer buffers
2699 * queued than there are buffers available.
2701 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2702 return res | POLLOUT | POLLWRNORM;
2704 if (list_empty(&q->done_list)) {
2706 * If the last buffer was dequeued from a capture queue,
2707 * return immediately. DQBUF will return -EPIPE.
2709 if (q->last_buffer_dequeued)
2710 return res | POLLIN | POLLRDNORM;
2712 poll_wait(file, &q->done_wq, wait);
2716 * Take first buffer available for dequeuing.
2718 spin_lock_irqsave(&q->done_lock, flags);
2719 if (!list_empty(&q->done_list))
2720 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2722 spin_unlock_irqrestore(&q->done_lock, flags);
2724 if (vb && (vb->state == VB2_BUF_STATE_DONE
2725 || vb->state == VB2_BUF_STATE_ERROR)) {
2726 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2727 res | POLLOUT | POLLWRNORM :
2728 res | POLLIN | POLLRDNORM;
2732 EXPORT_SYMBOL_GPL(vb2_poll);
2735 * vb2_queue_init() - initialize a videobuf2 queue
2736 * @q: videobuf2 queue; this structure should be allocated in driver
2738 * The vb2_queue structure should be allocated by the driver. The driver is
2739 * responsible of clearing it's content and setting initial values for some
2740 * required entries before calling this function.
2741 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2742 * to the struct vb2_queue description in include/media/videobuf2-core.h
2743 * for more information.
2745 int vb2_queue_init(struct vb2_queue *q)
2752 WARN_ON(!q->mem_ops) ||
2753 WARN_ON(!q->type) ||
2754 WARN_ON(!q->io_modes) ||
2755 WARN_ON(!q->ops->queue_setup) ||
2756 WARN_ON(!q->ops->buf_queue) ||
2757 WARN_ON(q->timestamp_flags &
2758 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2759 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2762 /* Warn that the driver should choose an appropriate timestamp type */
2763 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2764 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2766 INIT_LIST_HEAD(&q->queued_list);
2767 INIT_LIST_HEAD(&q->done_list);
2768 spin_lock_init(&q->done_lock);
2769 mutex_init(&q->mmap_lock);
2770 init_waitqueue_head(&q->done_wq);
2772 if (q->buf_struct_size == 0)
2773 q->buf_struct_size = sizeof(struct vb2_buffer);
2777 EXPORT_SYMBOL_GPL(vb2_queue_init);
2780 * vb2_queue_release() - stop streaming, release the queue and free memory
2781 * @q: videobuf2 queue
2783 * This function stops streaming and performs necessary clean ups, including
2784 * freeing video buffer memory. The driver is responsible for freeing
2785 * the vb2_queue structure itself.
2787 void vb2_queue_release(struct vb2_queue *q)
2789 __vb2_cleanup_fileio(q);
2790 __vb2_queue_cancel(q);
2791 mutex_lock(&q->mmap_lock);
2792 __vb2_queue_free(q, q->num_buffers);
2793 mutex_unlock(&q->mmap_lock);
2795 EXPORT_SYMBOL_GPL(vb2_queue_release);
2798 * struct vb2_fileio_buf - buffer context used by file io emulator
2800 * vb2 provides a compatibility layer and emulator of file io (read and
2801 * write) calls on top of streaming API. This structure is used for
2802 * tracking context related to the buffers.
2804 struct vb2_fileio_buf {
2808 unsigned int queued:1;
2812 * struct vb2_fileio_data - queue context used by file io emulator
2814 * @cur_index: the index of the buffer currently being read from or
2815 * written to. If equal to q->num_buffers then a new buffer
2817 * @initial_index: in the read() case all buffers are queued up immediately
2818 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2819 * buffers. However, in the write() case no buffers are initially
2820 * queued, instead whenever a buffer is full it is queued up by
2821 * __vb2_perform_fileio(). Only once all available buffers have
2822 * been queued up will __vb2_perform_fileio() start to dequeue
2823 * buffers. This means that initially __vb2_perform_fileio()
2824 * needs to know what buffer index to use when it is queuing up
2825 * the buffers for the first time. That initial index is stored
2826 * in this field. Once it is equal to q->num_buffers all
2827 * available buffers have been queued and __vb2_perform_fileio()
2828 * should start the normal dequeue/queue cycle.
2830 * vb2 provides a compatibility layer and emulator of file io (read and
2831 * write) calls on top of streaming API. For proper operation it required
2832 * this structure to save the driver state between each call of the read
2833 * or write function.
2835 struct vb2_fileio_data {
2836 struct v4l2_requestbuffers req;
2837 struct v4l2_plane p;
2838 struct v4l2_buffer b;
2839 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2840 unsigned int cur_index;
2841 unsigned int initial_index;
2842 unsigned int q_count;
2843 unsigned int dq_count;
2844 unsigned read_once:1;
2845 unsigned write_immediately:1;
2849 * __vb2_init_fileio() - initialize file io emulator
2850 * @q: videobuf2 queue
2851 * @read: mode selector (1 means read, 0 means write)
2853 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2855 struct vb2_fileio_data *fileio;
2857 unsigned int count = 0;
2862 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2863 (!read && !(q->io_modes & VB2_WRITE))))
2867 * Check if device supports mapping buffers to kernel virtual space.
2869 if (!q->mem_ops->vaddr)
2873 * Check if streaming api has not been already activated.
2875 if (q->streaming || q->num_buffers > 0)
2879 * Start with count 1, driver can increase it in queue_setup()
2883 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2884 (read) ? "read" : "write", count, q->fileio_read_once,
2885 q->fileio_write_immediately);
2887 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2891 fileio->read_once = q->fileio_read_once;
2892 fileio->write_immediately = q->fileio_write_immediately;
2895 * Request buffers and use MMAP type to force driver
2896 * to allocate buffers by itself.
2898 fileio->req.count = count;
2899 fileio->req.memory = V4L2_MEMORY_MMAP;
2900 fileio->req.type = q->type;
2902 ret = __reqbufs(q, &fileio->req);
2907 * Check if plane_count is correct
2908 * (multiplane buffers are not supported).
2910 if (q->bufs[0]->num_planes != 1) {
2916 * Get kernel address of each buffer.
2918 for (i = 0; i < q->num_buffers; i++) {
2919 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2920 if (fileio->bufs[i].vaddr == NULL) {
2924 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2928 * Read mode requires pre queuing of all buffers.
2931 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2934 * Queue all buffers.
2936 for (i = 0; i < q->num_buffers; i++) {
2937 struct v4l2_buffer *b = &fileio->b;
2939 memset(b, 0, sizeof(*b));
2941 if (is_multiplanar) {
2942 memset(&fileio->p, 0, sizeof(fileio->p));
2943 b->m.planes = &fileio->p;
2946 b->memory = q->memory;
2948 ret = vb2_internal_qbuf(q, b);
2951 fileio->bufs[i].queued = 1;
2954 * All buffers have been queued, so mark that by setting
2955 * initial_index to q->num_buffers
2957 fileio->initial_index = q->num_buffers;
2958 fileio->cur_index = q->num_buffers;
2964 ret = vb2_internal_streamon(q, q->type);
2971 fileio->req.count = 0;
2972 __reqbufs(q, &fileio->req);
2981 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2982 * @q: videobuf2 queue
2984 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2986 struct vb2_fileio_data *fileio = q->fileio;
2989 vb2_internal_streamoff(q, q->type);
2991 fileio->req.count = 0;
2992 vb2_reqbufs(q, &fileio->req);
2994 dprintk(3, "file io emulator closed\n");
3000 * __vb2_perform_fileio() - perform a single file io (read or write) operation
3001 * @q: videobuf2 queue
3002 * @data: pointed to target userspace buffer
3003 * @count: number of bytes to read or write
3004 * @ppos: file handle position tracking pointer
3005 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
3006 * @read: access mode selector (1 means read, 0 means write)
3008 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
3009 loff_t *ppos, int nonblock, int read)
3011 struct vb2_fileio_data *fileio;
3012 struct vb2_fileio_buf *buf;
3013 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
3015 * When using write() to write data to an output video node the vb2 core
3016 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
3017 * else is able to provide this information with the write() operation.
3019 bool set_timestamp = !read &&
3020 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3021 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3024 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
3025 read ? "read" : "write", (long)*ppos, count,
3026 nonblock ? "non" : "");
3032 * Initialize emulator on first call.
3034 if (!vb2_fileio_is_active(q)) {
3035 ret = __vb2_init_fileio(q, read);
3036 dprintk(3, "vb2_init_fileio result: %d\n", ret);
3043 * Check if we need to dequeue the buffer.
3045 index = fileio->cur_index;
3046 if (index >= q->num_buffers) {
3048 * Call vb2_dqbuf to get buffer back.
3050 memset(&fileio->b, 0, sizeof(fileio->b));
3051 fileio->b.type = q->type;
3052 fileio->b.memory = q->memory;
3053 if (is_multiplanar) {
3054 memset(&fileio->p, 0, sizeof(fileio->p));
3055 fileio->b.m.planes = &fileio->p;
3056 fileio->b.length = 1;
3058 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
3059 dprintk(5, "vb2_dqbuf result: %d\n", ret);
3062 fileio->dq_count += 1;
3064 fileio->cur_index = index = fileio->b.index;
3065 buf = &fileio->bufs[index];
3068 * Get number of bytes filled by the driver
3072 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
3073 : vb2_plane_size(q->bufs[index], 0);
3074 /* Compensate for data_offset on read in the multiplanar case. */
3075 if (is_multiplanar && read &&
3076 fileio->b.m.planes[0].data_offset < buf->size) {
3077 buf->pos = fileio->b.m.planes[0].data_offset;
3078 buf->size -= buf->pos;
3081 buf = &fileio->bufs[index];
3085 * Limit count on last few bytes of the buffer.
3087 if (buf->pos + count > buf->size) {
3088 count = buf->size - buf->pos;
3089 dprintk(5, "reducing read count: %zd\n", count);
3093 * Transfer data to userspace.
3095 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3096 count, index, buf->pos);
3098 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3100 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3102 dprintk(3, "error copying data\n");
3113 * Queue next buffer if required.
3115 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
3117 * Check if this is the last buffer to read.
3119 if (read && fileio->read_once && fileio->dq_count == 1) {
3120 dprintk(3, "read limit reached\n");
3121 return __vb2_cleanup_fileio(q);
3125 * Call vb2_qbuf and give buffer to the driver.
3127 memset(&fileio->b, 0, sizeof(fileio->b));
3128 fileio->b.type = q->type;
3129 fileio->b.memory = q->memory;
3130 fileio->b.index = index;
3131 fileio->b.bytesused = buf->pos;
3132 if (is_multiplanar) {
3133 memset(&fileio->p, 0, sizeof(fileio->p));
3134 fileio->p.bytesused = buf->pos;
3135 fileio->b.m.planes = &fileio->p;
3136 fileio->b.length = 1;
3139 v4l2_get_timestamp(&fileio->b.timestamp);
3140 ret = vb2_internal_qbuf(q, &fileio->b);
3141 dprintk(5, "vb2_dbuf result: %d\n", ret);
3146 * Buffer has been queued, update the status
3150 buf->size = vb2_plane_size(q->bufs[index], 0);
3151 fileio->q_count += 1;
3153 * If we are queuing up buffers for the first time, then
3154 * increase initial_index by one.
3156 if (fileio->initial_index < q->num_buffers)
3157 fileio->initial_index++;
3159 * The next buffer to use is either a buffer that's going to be
3160 * queued for the first time (initial_index < q->num_buffers)
3161 * or it is equal to q->num_buffers, meaning that the next
3162 * time we need to dequeue a buffer since we've now queued up
3163 * all the 'first time' buffers.
3165 fileio->cur_index = fileio->initial_index;
3169 * Return proper number of bytes processed.
3176 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3177 loff_t *ppos, int nonblocking)
3179 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3181 EXPORT_SYMBOL_GPL(vb2_read);
3183 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3184 loff_t *ppos, int nonblocking)
3186 return __vb2_perform_fileio(q, (char __user *) data, count,
3187 ppos, nonblocking, 0);
3189 EXPORT_SYMBOL_GPL(vb2_write);
3191 struct vb2_threadio_data {
3192 struct task_struct *thread;
3198 static int vb2_thread(void *data)
3200 struct vb2_queue *q = data;
3201 struct vb2_threadio_data *threadio = q->threadio;
3202 struct vb2_fileio_data *fileio = q->fileio;
3203 bool set_timestamp = false;
3208 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3209 prequeue = q->num_buffers;
3211 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3212 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3218 struct vb2_buffer *vb;
3221 * Call vb2_dqbuf to get buffer back.
3223 memset(&fileio->b, 0, sizeof(fileio->b));
3224 fileio->b.type = q->type;
3225 fileio->b.memory = q->memory;
3227 fileio->b.index = index++;
3230 call_void_qop(q, wait_finish, q);
3231 if (!threadio->stop)
3232 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3233 call_void_qop(q, wait_prepare, q);
3234 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3236 if (ret || threadio->stop)
3240 vb = q->bufs[fileio->b.index];
3241 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3242 if (threadio->fnc(vb, threadio->priv))
3244 call_void_qop(q, wait_finish, q);
3246 v4l2_get_timestamp(&fileio->b.timestamp);
3247 if (!threadio->stop)
3248 ret = vb2_internal_qbuf(q, &fileio->b);
3249 call_void_qop(q, wait_prepare, q);
3250 if (ret || threadio->stop)
3254 /* Hmm, linux becomes *very* unhappy without this ... */
3255 while (!kthread_should_stop()) {
3256 set_current_state(TASK_INTERRUPTIBLE);
3263 * This function should not be used for anything else but the videobuf2-dvb
3264 * support. If you think you have another good use-case for this, then please
3265 * contact the linux-media mailinglist first.
3267 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3268 const char *thread_name)
3270 struct vb2_threadio_data *threadio;
3277 if (WARN_ON(q->fileio))
3280 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3281 if (threadio == NULL)
3283 threadio->fnc = fnc;
3284 threadio->priv = priv;
3286 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3287 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3290 q->threadio = threadio;
3291 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3292 if (IS_ERR(threadio->thread)) {
3293 ret = PTR_ERR(threadio->thread);
3294 threadio->thread = NULL;
3300 __vb2_cleanup_fileio(q);
3305 EXPORT_SYMBOL_GPL(vb2_thread_start);
3307 int vb2_thread_stop(struct vb2_queue *q)
3309 struct vb2_threadio_data *threadio = q->threadio;
3312 if (threadio == NULL)
3314 threadio->stop = true;
3315 /* Wake up all pending sleeps in the thread */
3317 err = kthread_stop(threadio->thread);
3318 __vb2_cleanup_fileio(q);
3319 threadio->thread = NULL;
3324 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3327 * The following functions are not part of the vb2 core API, but are helper
3328 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3329 * and struct vb2_ops.
3330 * They contain boilerplate code that most if not all drivers have to do
3331 * and so they simplify the driver code.
3334 /* The queue is busy if there is a owner and you are not that owner. */
3335 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3337 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3340 /* vb2 ioctl helpers */
3342 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3343 struct v4l2_requestbuffers *p)
3345 struct video_device *vdev = video_devdata(file);
3346 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3350 if (vb2_queue_is_busy(vdev, file))
3352 res = __reqbufs(vdev->queue, p);
3353 /* If count == 0, then the owner has released all buffers and he
3354 is no longer owner of the queue. Otherwise we have a new owner. */
3356 vdev->queue->owner = p->count ? file->private_data : NULL;
3359 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3361 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3362 struct v4l2_create_buffers *p)
3364 struct video_device *vdev = video_devdata(file);
3365 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3367 p->index = vdev->queue->num_buffers;
3368 /* If count == 0, then just check if memory and type are valid.
3369 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3371 return res != -EBUSY ? res : 0;
3374 if (vb2_queue_is_busy(vdev, file))
3376 res = __create_bufs(vdev->queue, p);
3378 vdev->queue->owner = file->private_data;
3381 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3383 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3384 struct v4l2_buffer *p)
3386 struct video_device *vdev = video_devdata(file);
3388 if (vb2_queue_is_busy(vdev, file))
3390 return vb2_prepare_buf(vdev->queue, p);
3392 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3394 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3396 struct video_device *vdev = video_devdata(file);
3398 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3399 return vb2_querybuf(vdev->queue, p);
3401 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3403 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3405 struct video_device *vdev = video_devdata(file);
3407 if (vb2_queue_is_busy(vdev, file))
3409 return vb2_qbuf(vdev->queue, p);
3411 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3413 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3415 struct video_device *vdev = video_devdata(file);
3417 if (vb2_queue_is_busy(vdev, file))
3419 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3421 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3423 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3425 struct video_device *vdev = video_devdata(file);
3427 if (vb2_queue_is_busy(vdev, file))
3429 return vb2_streamon(vdev->queue, i);
3431 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3433 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3435 struct video_device *vdev = video_devdata(file);
3437 if (vb2_queue_is_busy(vdev, file))
3439 return vb2_streamoff(vdev->queue, i);
3441 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3443 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3445 struct video_device *vdev = video_devdata(file);
3447 if (vb2_queue_is_busy(vdev, file))
3449 return vb2_expbuf(vdev->queue, p);
3451 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3453 /* v4l2_file_operations helpers */
3455 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3457 struct video_device *vdev = video_devdata(file);
3459 return vb2_mmap(vdev->queue, vma);
3461 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3463 int _vb2_fop_release(struct file *file, struct mutex *lock)
3465 struct video_device *vdev = video_devdata(file);
3469 if (file->private_data == vdev->queue->owner) {
3470 vb2_queue_release(vdev->queue);
3471 vdev->queue->owner = NULL;
3475 return v4l2_fh_release(file);
3477 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3479 int vb2_fop_release(struct file *file)
3481 struct video_device *vdev = video_devdata(file);
3482 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3484 return _vb2_fop_release(file, lock);
3486 EXPORT_SYMBOL_GPL(vb2_fop_release);
3488 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3489 size_t count, loff_t *ppos)
3491 struct video_device *vdev = video_devdata(file);
3492 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3495 if (!(vdev->queue->io_modes & VB2_WRITE))
3497 if (lock && mutex_lock_interruptible(lock))
3498 return -ERESTARTSYS;
3499 if (vb2_queue_is_busy(vdev, file))
3501 err = vb2_write(vdev->queue, buf, count, ppos,
3502 file->f_flags & O_NONBLOCK);
3503 if (vdev->queue->fileio)
3504 vdev->queue->owner = file->private_data;
3510 EXPORT_SYMBOL_GPL(vb2_fop_write);
3512 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3513 size_t count, loff_t *ppos)
3515 struct video_device *vdev = video_devdata(file);
3516 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3519 if (!(vdev->queue->io_modes & VB2_READ))
3521 if (lock && mutex_lock_interruptible(lock))
3522 return -ERESTARTSYS;
3523 if (vb2_queue_is_busy(vdev, file))
3525 err = vb2_read(vdev->queue, buf, count, ppos,
3526 file->f_flags & O_NONBLOCK);
3527 if (vdev->queue->fileio)
3528 vdev->queue->owner = file->private_data;
3534 EXPORT_SYMBOL_GPL(vb2_fop_read);
3536 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3538 struct video_device *vdev = video_devdata(file);
3539 struct vb2_queue *q = vdev->queue;
3540 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3545 * If this helper doesn't know how to lock, then you shouldn't be using
3546 * it but you should write your own.
3550 if (lock && mutex_lock_interruptible(lock))
3555 res = vb2_poll(vdev->queue, file, wait);
3557 /* If fileio was started, then we have a new queue owner. */
3558 if (!fileio && q->fileio)
3559 q->owner = file->private_data;
3564 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3567 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3568 unsigned long len, unsigned long pgoff, unsigned long flags)
3570 struct video_device *vdev = video_devdata(file);
3572 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3574 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3577 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3579 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3581 mutex_unlock(vq->lock);
3583 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3585 void vb2_ops_wait_finish(struct vb2_queue *vq)
3587 mutex_lock(vq->lock);
3589 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3591 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3592 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3593 MODULE_LICENSE("GPL");