2 * videobuf2-core.c - V4L2 driver helper framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
34 module_param(debug, int, 0644);
36 #define dprintk(level, fmt, arg...) \
39 pr_debug("vb2: %s: " fmt, __func__, ## arg); \
42 #ifdef CONFIG_VIDEO_ADV_DEBUG
45 * If advanced debugging is on, then count how often each op is called
46 * successfully, which can either be per-buffer or per-queue.
48 * This makes it easy to check that the 'init' and 'cleanup'
49 * (and variations thereof) stay balanced.
52 #define log_memop(vb, op) \
53 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
54 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
55 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
57 #define call_memop(vb, op, args...) \
59 struct vb2_queue *_q = (vb)->vb2_queue; \
63 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
65 (vb)->cnt_mem_ ## op++; \
69 #define call_ptr_memop(vb, op, args...) \
71 struct vb2_queue *_q = (vb)->vb2_queue; \
75 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
76 if (!IS_ERR_OR_NULL(ptr)) \
77 (vb)->cnt_mem_ ## op++; \
81 #define call_void_memop(vb, op, args...) \
83 struct vb2_queue *_q = (vb)->vb2_queue; \
86 if (_q->mem_ops->op) \
87 _q->mem_ops->op(args); \
88 (vb)->cnt_mem_ ## op++; \
91 #define log_qop(q, op) \
92 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
93 (q)->ops->op ? "" : " (nop)")
95 #define call_qop(q, op, args...) \
100 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
106 #define call_void_qop(q, op, args...) \
110 (q)->ops->op(args); \
114 #define log_vb_qop(vb, op, args...) \
115 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
116 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
117 (vb)->vb2_queue->ops->op ? "" : " (nop)")
119 #define call_vb_qop(vb, op, args...) \
123 log_vb_qop(vb, op); \
124 err = (vb)->vb2_queue->ops->op ? \
125 (vb)->vb2_queue->ops->op(args) : 0; \
127 (vb)->cnt_ ## op++; \
131 #define call_void_vb_qop(vb, op, args...) \
133 log_vb_qop(vb, op); \
134 if ((vb)->vb2_queue->ops->op) \
135 (vb)->vb2_queue->ops->op(args); \
136 (vb)->cnt_ ## op++; \
141 #define call_memop(vb, op, args...) \
142 ((vb)->vb2_queue->mem_ops->op ? \
143 (vb)->vb2_queue->mem_ops->op(args) : 0)
145 #define call_ptr_memop(vb, op, args...) \
146 ((vb)->vb2_queue->mem_ops->op ? \
147 (vb)->vb2_queue->mem_ops->op(args) : NULL)
149 #define call_void_memop(vb, op, args...) \
151 if ((vb)->vb2_queue->mem_ops->op) \
152 (vb)->vb2_queue->mem_ops->op(args); \
155 #define call_qop(q, op, args...) \
156 ((q)->ops->op ? (q)->ops->op(args) : 0)
158 #define call_void_qop(q, op, args...) \
161 (q)->ops->op(args); \
164 #define call_vb_qop(vb, op, args...) \
165 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
167 #define call_void_vb_qop(vb, op, args...) \
169 if ((vb)->vb2_queue->ops->op) \
170 (vb)->vb2_queue->ops->op(args); \
175 /* Flags that are set by the vb2 core */
176 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
177 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
178 V4L2_BUF_FLAG_PREPARED | \
179 V4L2_BUF_FLAG_TIMESTAMP_MASK)
180 /* Output buffer flags that should be passed on to the driver */
181 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
182 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
184 static void __vb2_queue_cancel(struct vb2_queue *q);
187 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
189 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
191 struct vb2_queue *q = vb->vb2_queue;
196 * Allocate memory for all planes in this buffer
197 * NOTE: mmapped areas should be page aligned
199 for (plane = 0; plane < vb->num_planes; ++plane) {
200 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
202 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
204 if (IS_ERR_OR_NULL(mem_priv))
207 /* Associate allocator private data with this plane */
208 vb->planes[plane].mem_priv = mem_priv;
209 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
214 /* Free already allocated memory if one of the allocations failed */
215 for (; plane > 0; --plane) {
216 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
217 vb->planes[plane - 1].mem_priv = NULL;
224 * __vb2_buf_mem_free() - free memory of the given buffer
226 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
230 for (plane = 0; plane < vb->num_planes; ++plane) {
231 call_void_memop(vb, put, vb->planes[plane].mem_priv);
232 vb->planes[plane].mem_priv = NULL;
233 dprintk(3, "freed plane %d of buffer %d\n", plane,
239 * __vb2_buf_userptr_put() - release userspace memory associated with
242 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
246 for (plane = 0; plane < vb->num_planes; ++plane) {
247 if (vb->planes[plane].mem_priv)
248 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
249 vb->planes[plane].mem_priv = NULL;
254 * __vb2_plane_dmabuf_put() - release memory associated with
255 * a DMABUF shared plane
257 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
263 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
265 call_void_memop(vb, detach_dmabuf, p->mem_priv);
266 dma_buf_put(p->dbuf);
267 memset(p, 0, sizeof(*p));
271 * __vb2_buf_dmabuf_put() - release memory associated with
272 * a DMABUF shared buffer
274 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
278 for (plane = 0; plane < vb->num_planes; ++plane)
279 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
283 * __setup_lengths() - setup initial lengths for every plane in
284 * every buffer on the queue
286 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
288 unsigned int buffer, plane;
289 struct vb2_buffer *vb;
291 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
292 vb = q->bufs[buffer];
296 for (plane = 0; plane < vb->num_planes; ++plane)
297 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
302 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
303 * every buffer on the queue
305 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
307 unsigned int buffer, plane;
308 struct vb2_buffer *vb;
311 if (q->num_buffers) {
312 struct v4l2_plane *p;
313 vb = q->bufs[q->num_buffers - 1];
314 p = &vb->v4l2_planes[vb->num_planes - 1];
315 off = PAGE_ALIGN(p->m.mem_offset + p->length);
320 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
321 vb = q->bufs[buffer];
325 for (plane = 0; plane < vb->num_planes; ++plane) {
326 vb->v4l2_planes[plane].m.mem_offset = off;
328 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
331 off += vb->v4l2_planes[plane].length;
332 off = PAGE_ALIGN(off);
338 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
339 * video buffer memory for all buffers/planes on the queue and initializes the
342 * Returns the number of buffers successfully allocated.
344 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
345 unsigned int num_buffers, unsigned int num_planes)
348 struct vb2_buffer *vb;
351 for (buffer = 0; buffer < num_buffers; ++buffer) {
352 /* Allocate videobuf buffer structures */
353 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
355 dprintk(1, "memory alloc for buffer struct failed\n");
359 /* Length stores number of planes for multiplanar buffers */
360 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
361 vb->v4l2_buf.length = num_planes;
363 vb->state = VB2_BUF_STATE_DEQUEUED;
365 vb->num_planes = num_planes;
366 vb->v4l2_buf.index = q->num_buffers + buffer;
367 vb->v4l2_buf.type = q->type;
368 vb->v4l2_buf.memory = memory;
370 /* Allocate video buffer memory for the MMAP type */
371 if (memory == V4L2_MEMORY_MMAP) {
372 ret = __vb2_buf_mem_alloc(vb);
374 dprintk(1, "failed allocating memory for "
375 "buffer %d\n", buffer);
380 * Call the driver-provided buffer initialization
381 * callback, if given. An error in initialization
382 * results in queue setup failure.
384 ret = call_vb_qop(vb, buf_init, vb);
386 dprintk(1, "buffer %d %p initialization"
387 " failed\n", buffer, vb);
388 __vb2_buf_mem_free(vb);
394 q->bufs[q->num_buffers + buffer] = vb;
397 __setup_lengths(q, buffer);
398 if (memory == V4L2_MEMORY_MMAP)
399 __setup_offsets(q, buffer);
401 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
408 * __vb2_free_mem() - release all video buffer memory for a given queue
410 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
413 struct vb2_buffer *vb;
415 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
417 vb = q->bufs[buffer];
421 /* Free MMAP buffers or release USERPTR buffers */
422 if (q->memory == V4L2_MEMORY_MMAP)
423 __vb2_buf_mem_free(vb);
424 else if (q->memory == V4L2_MEMORY_DMABUF)
425 __vb2_buf_dmabuf_put(vb);
427 __vb2_buf_userptr_put(vb);
432 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
433 * related information, if no buffers are left return the queue to an
434 * uninitialized state. Might be called even if the queue has already been freed.
436 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
441 * Sanity check: when preparing a buffer the queue lock is released for
442 * a short while (see __buf_prepare for the details), which would allow
443 * a race with a reqbufs which can call this function. Removing the
444 * buffers from underneath __buf_prepare is obviously a bad idea, so we
445 * check if any of the buffers is in the state PREPARING, and if so we
446 * just return -EAGAIN.
448 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
450 if (q->bufs[buffer] == NULL)
452 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
453 dprintk(1, "preparing buffers, cannot free\n");
458 /* Call driver-provided cleanup function for each buffer, if provided */
459 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
461 struct vb2_buffer *vb = q->bufs[buffer];
463 if (vb && vb->planes[0].mem_priv)
464 call_void_vb_qop(vb, buf_cleanup, vb);
467 /* Release video buffer memory */
468 __vb2_free_mem(q, buffers);
470 #ifdef CONFIG_VIDEO_ADV_DEBUG
472 * Check that all the calls were balances during the life-time of this
473 * queue. If not (or if the debug level is 1 or up), then dump the
474 * counters to the kernel log.
476 if (q->num_buffers) {
477 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
478 q->cnt_wait_prepare != q->cnt_wait_finish;
480 if (unbalanced || debug) {
481 pr_info("vb2: counters for queue %p:%s\n", q,
482 unbalanced ? " UNBALANCED!" : "");
483 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
484 q->cnt_queue_setup, q->cnt_start_streaming,
485 q->cnt_stop_streaming);
486 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
487 q->cnt_wait_prepare, q->cnt_wait_finish);
489 q->cnt_queue_setup = 0;
490 q->cnt_wait_prepare = 0;
491 q->cnt_wait_finish = 0;
492 q->cnt_start_streaming = 0;
493 q->cnt_stop_streaming = 0;
495 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
496 struct vb2_buffer *vb = q->bufs[buffer];
497 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
498 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
499 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
500 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
501 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
502 vb->cnt_buf_queue != vb->cnt_buf_done ||
503 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
504 vb->cnt_buf_init != vb->cnt_buf_cleanup;
506 if (unbalanced || debug) {
507 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
508 q, buffer, unbalanced ? " UNBALANCED!" : "");
509 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
510 vb->cnt_buf_init, vb->cnt_buf_cleanup,
511 vb->cnt_buf_prepare, vb->cnt_buf_finish);
512 pr_info("vb2: buf_queue: %u buf_done: %u\n",
513 vb->cnt_buf_queue, vb->cnt_buf_done);
514 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
515 vb->cnt_mem_alloc, vb->cnt_mem_put,
516 vb->cnt_mem_prepare, vb->cnt_mem_finish,
518 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
519 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
520 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
521 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
522 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
523 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
524 vb->cnt_mem_get_dmabuf,
525 vb->cnt_mem_num_users,
532 /* Free videobuf buffers */
533 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
535 kfree(q->bufs[buffer]);
536 q->bufs[buffer] = NULL;
539 q->num_buffers -= buffers;
540 if (!q->num_buffers) {
542 INIT_LIST_HEAD(&q->queued_list);
548 * __verify_planes_array() - verify that the planes array passed in struct
549 * v4l2_buffer from userspace can be safely used
551 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
553 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
556 /* Is memory for copying plane information present? */
557 if (NULL == b->m.planes) {
558 dprintk(1, "multi-planar buffer passed but "
559 "planes array not provided\n");
563 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
564 dprintk(1, "incorrect planes array length, "
565 "expected %d, got %d\n", vb->num_planes, b->length);
573 * __verify_length() - Verify that the bytesused value for each plane fits in
574 * the plane length and that the data offset doesn't exceed the bytesused value.
576 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
579 unsigned int bytesused;
582 if (!V4L2_TYPE_IS_OUTPUT(b->type))
585 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
586 for (plane = 0; plane < vb->num_planes; ++plane) {
587 length = (b->memory == V4L2_MEMORY_USERPTR ||
588 b->memory == V4L2_MEMORY_DMABUF)
589 ? b->m.planes[plane].length
590 : vb->v4l2_planes[plane].length;
591 bytesused = b->m.planes[plane].bytesused
592 ? b->m.planes[plane].bytesused : length;
594 if (b->m.planes[plane].bytesused > length)
597 if (b->m.planes[plane].data_offset > 0 &&
598 b->m.planes[plane].data_offset >= bytesused)
602 length = (b->memory == V4L2_MEMORY_USERPTR)
603 ? b->length : vb->v4l2_planes[0].length;
604 bytesused = b->bytesused ? b->bytesused : length;
606 if (b->bytesused > length)
614 * __buffer_in_use() - return true if the buffer is in use and
615 * the queue cannot be freed (by the means of REQBUFS(0)) call
617 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
620 for (plane = 0; plane < vb->num_planes; ++plane) {
621 void *mem_priv = vb->planes[plane].mem_priv;
623 * If num_users() has not been provided, call_memop
624 * will return 0, apparently nobody cares about this
625 * case anyway. If num_users() returns more than 1,
626 * we are not the only user of the plane's memory.
628 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
635 * __buffers_in_use() - return true if any buffers on the queue are in use and
636 * the queue cannot be freed (by the means of REQBUFS(0)) call
638 static bool __buffers_in_use(struct vb2_queue *q)
641 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
642 if (__buffer_in_use(q, q->bufs[buffer]))
649 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
650 * returned to userspace
652 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
654 struct vb2_queue *q = vb->vb2_queue;
656 /* Copy back data such as timestamp, flags, etc. */
657 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
658 b->reserved2 = vb->v4l2_buf.reserved2;
659 b->reserved = vb->v4l2_buf.reserved;
661 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
663 * Fill in plane-related data if userspace provided an array
664 * for it. The caller has already verified memory and size.
666 b->length = vb->num_planes;
667 memcpy(b->m.planes, vb->v4l2_planes,
668 b->length * sizeof(struct v4l2_plane));
671 * We use length and offset in v4l2_planes array even for
672 * single-planar buffers, but userspace does not.
674 b->length = vb->v4l2_planes[0].length;
675 b->bytesused = vb->v4l2_planes[0].bytesused;
676 if (q->memory == V4L2_MEMORY_MMAP)
677 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
678 else if (q->memory == V4L2_MEMORY_USERPTR)
679 b->m.userptr = vb->v4l2_planes[0].m.userptr;
680 else if (q->memory == V4L2_MEMORY_DMABUF)
681 b->m.fd = vb->v4l2_planes[0].m.fd;
685 * Clear any buffer state related flags.
687 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
688 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
689 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
690 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
692 * For non-COPY timestamps, drop timestamp source bits
693 * and obtain the timestamp source from the queue.
695 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
696 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
700 case VB2_BUF_STATE_QUEUED:
701 case VB2_BUF_STATE_ACTIVE:
702 b->flags |= V4L2_BUF_FLAG_QUEUED;
704 case VB2_BUF_STATE_ERROR:
705 b->flags |= V4L2_BUF_FLAG_ERROR;
707 case VB2_BUF_STATE_DONE:
708 b->flags |= V4L2_BUF_FLAG_DONE;
710 case VB2_BUF_STATE_PREPARED:
711 b->flags |= V4L2_BUF_FLAG_PREPARED;
713 case VB2_BUF_STATE_PREPARING:
714 case VB2_BUF_STATE_DEQUEUED:
719 if (__buffer_in_use(q, vb))
720 b->flags |= V4L2_BUF_FLAG_MAPPED;
724 * vb2_querybuf() - query video buffer information
726 * @b: buffer struct passed from userspace to vidioc_querybuf handler
729 * Should be called from vidioc_querybuf ioctl handler in driver.
730 * This function will verify the passed v4l2_buffer structure and fill the
731 * relevant information for the userspace.
733 * The return values from this function are intended to be directly returned
734 * from vidioc_querybuf handler in driver.
736 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
738 struct vb2_buffer *vb;
741 if (b->type != q->type) {
742 dprintk(1, "wrong buffer type\n");
746 if (b->index >= q->num_buffers) {
747 dprintk(1, "buffer index out of range\n");
750 vb = q->bufs[b->index];
751 ret = __verify_planes_array(vb, b);
753 __fill_v4l2_buffer(vb, b);
756 EXPORT_SYMBOL(vb2_querybuf);
759 * __verify_userptr_ops() - verify that all memory operations required for
760 * USERPTR queue type have been provided
762 static int __verify_userptr_ops(struct vb2_queue *q)
764 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
765 !q->mem_ops->put_userptr)
772 * __verify_mmap_ops() - verify that all memory operations required for
773 * MMAP queue type have been provided
775 static int __verify_mmap_ops(struct vb2_queue *q)
777 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
778 !q->mem_ops->put || !q->mem_ops->mmap)
785 * __verify_dmabuf_ops() - verify that all memory operations required for
786 * DMABUF queue type have been provided
788 static int __verify_dmabuf_ops(struct vb2_queue *q)
790 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
791 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
792 !q->mem_ops->unmap_dmabuf)
799 * __verify_memory_type() - Check whether the memory type and buffer type
800 * passed to a buffer operation are compatible with the queue.
802 static int __verify_memory_type(struct vb2_queue *q,
803 enum v4l2_memory memory, enum v4l2_buf_type type)
805 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
806 memory != V4L2_MEMORY_DMABUF) {
807 dprintk(1, "unsupported memory type\n");
811 if (type != q->type) {
812 dprintk(1, "requested type is incorrect\n");
817 * Make sure all the required memory ops for given memory type
820 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
821 dprintk(1, "MMAP for current setup unsupported\n");
825 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
826 dprintk(1, "USERPTR for current setup unsupported\n");
830 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
831 dprintk(1, "DMABUF for current setup unsupported\n");
836 * Place the busy tests at the end: -EBUSY can be ignored when
837 * create_bufs is called with count == 0, but count == 0 should still
838 * do the memory and type validation.
840 if (vb2_fileio_is_active(q)) {
841 dprintk(1, "file io in progress\n");
848 * __reqbufs() - Initiate streaming
849 * @q: videobuf2 queue
850 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
852 * Should be called from vidioc_reqbufs ioctl handler of a driver.
854 * 1) verifies streaming parameters passed from the userspace,
855 * 2) sets up the queue,
856 * 3) negotiates number of buffers and planes per buffer with the driver
857 * to be used during streaming,
858 * 4) allocates internal buffer structures (struct vb2_buffer), according to
859 * the agreed parameters,
860 * 5) for MMAP memory type, allocates actual video memory, using the
861 * memory handling/allocation routines provided during queue initialization
863 * If req->count is 0, all the memory will be freed instead.
864 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
865 * and the queue is not busy, memory will be reallocated.
867 * The return values from this function are intended to be directly returned
868 * from vidioc_reqbufs handler in driver.
870 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
872 unsigned int num_buffers, allocated_buffers, num_planes = 0;
876 dprintk(1, "streaming active\n");
880 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
882 * We already have buffers allocated, so first check if they
883 * are not in use and can be freed.
885 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
886 dprintk(1, "memory in use, cannot free\n");
891 * Call queue_cancel to clean up any buffers in the PREPARED or
892 * QUEUED state which is possible if buffers were prepared or
893 * queued without ever calling STREAMON.
895 __vb2_queue_cancel(q);
896 ret = __vb2_queue_free(q, q->num_buffers);
901 * In case of REQBUFS(0) return immediately without calling
902 * driver's queue_setup() callback and allocating resources.
909 * Make sure the requested values and current defaults are sane.
911 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
912 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
913 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
914 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
915 q->memory = req->memory;
918 * Ask the driver how many buffers and planes per buffer it requires.
919 * Driver also sets the size and allocator context for each plane.
921 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
922 q->plane_sizes, q->alloc_ctx);
926 /* Finally, allocate buffers and video memory */
927 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
928 if (allocated_buffers == 0) {
929 dprintk(1, "memory allocation failed\n");
934 * There is no point in continuing if we can't allocate the minimum
935 * number of buffers needed by this vb2_queue.
937 if (allocated_buffers < q->min_buffers_needed)
941 * Check if driver can handle the allocated number of buffers.
943 if (!ret && allocated_buffers < num_buffers) {
944 num_buffers = allocated_buffers;
946 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
947 &num_planes, q->plane_sizes, q->alloc_ctx);
949 if (!ret && allocated_buffers < num_buffers)
953 * Either the driver has accepted a smaller number of buffers,
954 * or .queue_setup() returned an error
958 q->num_buffers = allocated_buffers;
962 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
963 * from q->num_buffers.
965 __vb2_queue_free(q, allocated_buffers);
970 * Return the number of successfully allocated buffers
973 req->count = allocated_buffers;
979 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
981 * @q: videobuf2 queue
982 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
984 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
986 int ret = __verify_memory_type(q, req->memory, req->type);
988 return ret ? ret : __reqbufs(q, req);
990 EXPORT_SYMBOL_GPL(vb2_reqbufs);
993 * __create_bufs() - Allocate buffers and any required auxiliary structs
994 * @q: videobuf2 queue
995 * @create: creation parameters, passed from userspace to vidioc_create_bufs
998 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1000 * 1) verifies parameter sanity
1001 * 2) calls the .queue_setup() queue operation
1002 * 3) performs any necessary memory allocations
1004 * The return values from this function are intended to be directly returned
1005 * from vidioc_create_bufs handler in driver.
1007 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1009 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1012 if (q->num_buffers == VIDEO_MAX_FRAME) {
1013 dprintk(1, "maximum number of buffers already allocated\n");
1017 if (!q->num_buffers) {
1018 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1019 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1020 q->memory = create->memory;
1023 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1026 * Ask the driver, whether the requested number of buffers, planes per
1027 * buffer and their sizes are acceptable
1029 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1030 &num_planes, q->plane_sizes, q->alloc_ctx);
1034 /* Finally, allocate buffers and video memory */
1035 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1037 if (allocated_buffers == 0) {
1038 dprintk(1, "memory allocation failed\n");
1043 * Check if driver can handle the so far allocated number of buffers.
1045 if (allocated_buffers < num_buffers) {
1046 num_buffers = allocated_buffers;
1049 * q->num_buffers contains the total number of buffers, that the
1050 * queue driver has set up
1052 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1053 &num_planes, q->plane_sizes, q->alloc_ctx);
1055 if (!ret && allocated_buffers < num_buffers)
1059 * Either the driver has accepted a smaller number of buffers,
1060 * or .queue_setup() returned an error
1064 q->num_buffers += allocated_buffers;
1068 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1069 * from q->num_buffers.
1071 __vb2_queue_free(q, allocated_buffers);
1076 * Return the number of successfully allocated buffers
1079 create->count = allocated_buffers;
1085 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1086 * memory and type values.
1087 * @q: videobuf2 queue
1088 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1091 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1093 int ret = __verify_memory_type(q, create->memory, create->format.type);
1095 create->index = q->num_buffers;
1096 if (create->count == 0)
1097 return ret != -EBUSY ? ret : 0;
1098 return ret ? ret : __create_bufs(q, create);
1100 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1103 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1104 * @vb: vb2_buffer to which the plane in question belongs to
1105 * @plane_no: plane number for which the address is to be returned
1107 * This function returns a kernel virtual address of a given plane if
1108 * such a mapping exist, NULL otherwise.
1110 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1112 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1115 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1118 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1121 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1122 * @vb: vb2_buffer to which the plane in question belongs to
1123 * @plane_no: plane number for which the cookie is to be returned
1125 * This function returns an allocator specific cookie for a given plane if
1126 * available, NULL otherwise. The allocator should provide some simple static
1127 * inline function, which would convert this cookie to the allocator specific
1128 * type that can be used directly by the driver to access the buffer. This can
1129 * be for example physical address, pointer to scatter list or IOMMU mapping.
1131 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1133 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1136 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1138 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1141 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1142 * @vb: vb2_buffer returned from the driver
1143 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1144 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1145 * If start_streaming fails then it should return buffers with state
1146 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1148 * This function should be called by the driver after a hardware operation on
1149 * a buffer is finished and the buffer may be returned to userspace. The driver
1150 * cannot use this buffer anymore until it is queued back to it by videobuf
1151 * by the means of buf_queue callback. Only buffers previously queued to the
1152 * driver by buf_queue can be passed to this function.
1154 * While streaming a buffer can only be returned in state DONE or ERROR.
1155 * The start_streaming op can also return them in case the DMA engine cannot
1156 * be started for some reason. In that case the buffers should be returned with
1159 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1161 struct vb2_queue *q = vb->vb2_queue;
1162 unsigned long flags;
1165 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1168 if (!q->start_streaming_called) {
1169 if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
1170 state = VB2_BUF_STATE_QUEUED;
1171 } else if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1172 state != VB2_BUF_STATE_ERROR)) {
1173 state = VB2_BUF_STATE_ERROR;
1176 #ifdef CONFIG_VIDEO_ADV_DEBUG
1178 * Although this is not a callback, it still does have to balance
1179 * with the buf_queue op. So update this counter manually.
1183 dprintk(4, "done processing on buffer %d, state: %d\n",
1184 vb->v4l2_buf.index, state);
1187 for (plane = 0; plane < vb->num_planes; ++plane)
1188 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1190 /* Add the buffer to the done buffers list */
1191 spin_lock_irqsave(&q->done_lock, flags);
1193 if (state != VB2_BUF_STATE_QUEUED)
1194 list_add_tail(&vb->done_entry, &q->done_list);
1195 atomic_dec(&q->owned_by_drv_count);
1196 spin_unlock_irqrestore(&q->done_lock, flags);
1198 if (state == VB2_BUF_STATE_QUEUED)
1201 /* Inform any processes that may be waiting for buffers */
1202 wake_up(&q->done_wq);
1204 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1207 * vb2_discard_done() - discard all buffers marked as DONE
1208 * @q: videobuf2 queue
1210 * This function is intended to be used with suspend/resume operations. It
1211 * discards all 'done' buffers as they would be too old to be requested after
1214 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1215 * delayed works before calling this function to make sure no buffer will be
1216 * touched by the driver and/or hardware.
1218 void vb2_discard_done(struct vb2_queue *q)
1220 struct vb2_buffer *vb;
1221 unsigned long flags;
1223 spin_lock_irqsave(&q->done_lock, flags);
1224 list_for_each_entry(vb, &q->done_list, done_entry)
1225 vb->state = VB2_BUF_STATE_ERROR;
1226 spin_unlock_irqrestore(&q->done_lock, flags);
1228 EXPORT_SYMBOL_GPL(vb2_discard_done);
1231 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1232 * v4l2_buffer by the userspace. The caller has already verified that struct
1233 * v4l2_buffer has a valid number of planes.
1235 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1236 struct v4l2_plane *v4l2_planes)
1240 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1241 if (b->memory == V4L2_MEMORY_USERPTR) {
1242 for (plane = 0; plane < vb->num_planes; ++plane) {
1243 v4l2_planes[plane].m.userptr =
1244 b->m.planes[plane].m.userptr;
1245 v4l2_planes[plane].length =
1246 b->m.planes[plane].length;
1249 if (b->memory == V4L2_MEMORY_DMABUF) {
1250 for (plane = 0; plane < vb->num_planes; ++plane) {
1251 v4l2_planes[plane].m.fd =
1252 b->m.planes[plane].m.fd;
1253 v4l2_planes[plane].length =
1254 b->m.planes[plane].length;
1258 /* Fill in driver-provided information for OUTPUT types */
1259 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1261 * Will have to go up to b->length when API starts
1262 * accepting variable number of planes.
1264 * If bytesused == 0 for the output buffer, then fall
1265 * back to the full buffer size. In that case
1266 * userspace clearly never bothered to set it and
1267 * it's a safe assumption that they really meant to
1268 * use the full plane sizes.
1270 for (plane = 0; plane < vb->num_planes; ++plane) {
1271 struct v4l2_plane *pdst = &v4l2_planes[plane];
1272 struct v4l2_plane *psrc = &b->m.planes[plane];
1274 pdst->bytesused = psrc->bytesused ?
1275 psrc->bytesused : pdst->length;
1276 pdst->data_offset = psrc->data_offset;
1281 * Single-planar buffers do not use planes array,
1282 * so fill in relevant v4l2_buffer struct fields instead.
1283 * In videobuf we use our internal V4l2_planes struct for
1284 * single-planar buffers as well, for simplicity.
1286 * If bytesused == 0 for the output buffer, then fall back
1287 * to the full buffer size as that's a sensible default.
1289 if (b->memory == V4L2_MEMORY_USERPTR) {
1290 v4l2_planes[0].m.userptr = b->m.userptr;
1291 v4l2_planes[0].length = b->length;
1294 if (b->memory == V4L2_MEMORY_DMABUF) {
1295 v4l2_planes[0].m.fd = b->m.fd;
1296 v4l2_planes[0].length = b->length;
1299 if (V4L2_TYPE_IS_OUTPUT(b->type))
1300 v4l2_planes[0].bytesused = b->bytesused ?
1301 b->bytesused : v4l2_planes[0].length;
1303 v4l2_planes[0].bytesused = 0;
1307 /* Zero flags that the vb2 core handles */
1308 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1309 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1310 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1312 * Non-COPY timestamps and non-OUTPUT queues will get
1313 * their timestamp and timestamp source flags from the
1316 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1319 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1321 * For output buffers mask out the timecode flag:
1322 * this will be handled later in vb2_internal_qbuf().
1323 * The 'field' is valid metadata for this output buffer
1324 * and so that needs to be copied here.
1326 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1327 vb->v4l2_buf.field = b->field;
1329 /* Zero any output buffer flags as this is a capture buffer */
1330 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1335 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1337 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1339 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1340 return call_vb_qop(vb, buf_prepare, vb);
1344 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1346 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1348 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1349 struct vb2_queue *q = vb->vb2_queue;
1353 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1354 bool reacquired = vb->planes[0].mem_priv == NULL;
1356 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1357 /* Copy relevant information provided by the userspace */
1358 __fill_vb2_buffer(vb, b, planes);
1360 for (plane = 0; plane < vb->num_planes; ++plane) {
1361 /* Skip the plane if already verified */
1362 if (vb->v4l2_planes[plane].m.userptr &&
1363 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1364 && vb->v4l2_planes[plane].length == planes[plane].length)
1367 dprintk(3, "userspace address for plane %d changed, "
1368 "reacquiring memory\n", plane);
1370 /* Check if the provided plane buffer is large enough */
1371 if (planes[plane].length < q->plane_sizes[plane]) {
1372 dprintk(1, "provided buffer size %u is less than "
1373 "setup size %u for plane %d\n",
1374 planes[plane].length,
1375 q->plane_sizes[plane], plane);
1380 /* Release previously acquired memory if present */
1381 if (vb->planes[plane].mem_priv) {
1384 call_void_vb_qop(vb, buf_cleanup, vb);
1386 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1389 vb->planes[plane].mem_priv = NULL;
1390 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1392 /* Acquire each plane's memory */
1393 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1394 planes[plane].m.userptr,
1395 planes[plane].length, write);
1396 if (IS_ERR_OR_NULL(mem_priv)) {
1397 dprintk(1, "failed acquiring userspace "
1398 "memory for plane %d\n", plane);
1399 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1402 vb->planes[plane].mem_priv = mem_priv;
1406 * Now that everything is in order, copy relevant information
1407 * provided by userspace.
1409 for (plane = 0; plane < vb->num_planes; ++plane)
1410 vb->v4l2_planes[plane] = planes[plane];
1414 * One or more planes changed, so we must call buf_init to do
1415 * the driver-specific initialization on the newly acquired
1416 * buffer, if provided.
1418 ret = call_vb_qop(vb, buf_init, vb);
1420 dprintk(1, "buffer initialization failed\n");
1425 ret = call_vb_qop(vb, buf_prepare, vb);
1427 dprintk(1, "buffer preparation failed\n");
1428 call_void_vb_qop(vb, buf_cleanup, vb);
1434 /* In case of errors, release planes that were already acquired */
1435 for (plane = 0; plane < vb->num_planes; ++plane) {
1436 if (vb->planes[plane].mem_priv)
1437 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1438 vb->planes[plane].mem_priv = NULL;
1439 vb->v4l2_planes[plane].m.userptr = 0;
1440 vb->v4l2_planes[plane].length = 0;
1447 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1449 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1451 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1452 struct vb2_queue *q = vb->vb2_queue;
1456 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1457 bool reacquired = vb->planes[0].mem_priv == NULL;
1459 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1460 /* Copy relevant information provided by the userspace */
1461 __fill_vb2_buffer(vb, b, planes);
1463 for (plane = 0; plane < vb->num_planes; ++plane) {
1464 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1466 if (IS_ERR_OR_NULL(dbuf)) {
1467 dprintk(1, "invalid dmabuf fd for plane %d\n",
1473 /* use DMABUF size if length is not provided */
1474 if (planes[plane].length == 0)
1475 planes[plane].length = dbuf->size;
1477 if (planes[plane].length < q->plane_sizes[plane]) {
1478 dprintk(1, "invalid dmabuf length for plane %d\n",
1484 /* Skip the plane if already verified */
1485 if (dbuf == vb->planes[plane].dbuf &&
1486 vb->v4l2_planes[plane].length == planes[plane].length) {
1491 dprintk(1, "buffer for plane %d changed\n", plane);
1495 call_void_vb_qop(vb, buf_cleanup, vb);
1498 /* Release previously acquired memory if present */
1499 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1500 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1502 /* Acquire each plane's memory */
1503 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1504 dbuf, planes[plane].length, write);
1505 if (IS_ERR(mem_priv)) {
1506 dprintk(1, "failed to attach dmabuf\n");
1507 ret = PTR_ERR(mem_priv);
1512 vb->planes[plane].dbuf = dbuf;
1513 vb->planes[plane].mem_priv = mem_priv;
1516 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1517 * really we want to do this just before the DMA, not while queueing
1520 for (plane = 0; plane < vb->num_planes; ++plane) {
1521 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1523 dprintk(1, "failed to map dmabuf for plane %d\n",
1527 vb->planes[plane].dbuf_mapped = 1;
1531 * Now that everything is in order, copy relevant information
1532 * provided by userspace.
1534 for (plane = 0; plane < vb->num_planes; ++plane)
1535 vb->v4l2_planes[plane] = planes[plane];
1539 * Call driver-specific initialization on the newly acquired buffer,
1542 ret = call_vb_qop(vb, buf_init, vb);
1544 dprintk(1, "buffer initialization failed\n");
1549 ret = call_vb_qop(vb, buf_prepare, vb);
1551 dprintk(1, "buffer preparation failed\n");
1552 call_void_vb_qop(vb, buf_cleanup, vb);
1558 /* In case of errors, release planes that were already acquired */
1559 __vb2_buf_dmabuf_put(vb);
1565 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1567 static void __enqueue_in_driver(struct vb2_buffer *vb)
1569 struct vb2_queue *q = vb->vb2_queue;
1572 vb->state = VB2_BUF_STATE_ACTIVE;
1573 atomic_inc(&q->owned_by_drv_count);
1576 for (plane = 0; plane < vb->num_planes; ++plane)
1577 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1579 call_void_vb_qop(vb, buf_queue, vb);
1582 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1584 struct vb2_queue *q = vb->vb2_queue;
1585 struct rw_semaphore *mmap_sem;
1588 ret = __verify_length(vb, b);
1590 dprintk(1, "plane parameters verification failed: %d\n", ret);
1593 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1595 * If the format's field is ALTERNATE, then the buffer's field
1596 * should be either TOP or BOTTOM, not ALTERNATE since that
1597 * makes no sense. The driver has to know whether the
1598 * buffer represents a top or a bottom field in order to
1599 * program any DMA correctly. Using ALTERNATE is wrong, since
1600 * that just says that it is either a top or a bottom field,
1601 * but not which of the two it is.
1603 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1608 dprintk(1, "fatal error occurred on queue\n");
1612 vb->state = VB2_BUF_STATE_PREPARING;
1613 vb->v4l2_buf.timestamp.tv_sec = 0;
1614 vb->v4l2_buf.timestamp.tv_usec = 0;
1615 vb->v4l2_buf.sequence = 0;
1617 switch (q->memory) {
1618 case V4L2_MEMORY_MMAP:
1619 ret = __qbuf_mmap(vb, b);
1621 case V4L2_MEMORY_USERPTR:
1623 * In case of user pointer buffers vb2 allocators need to get
1624 * direct access to userspace pages. This requires getting
1625 * the mmap semaphore for read access in the current process
1626 * structure. The same semaphore is taken before calling mmap
1627 * operation, while both qbuf/prepare_buf and mmap are called
1628 * by the driver or v4l2 core with the driver's lock held.
1629 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1630 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1631 * the videobuf2 core releases the driver's lock, takes
1632 * mmap_sem and then takes the driver's lock again.
1634 mmap_sem = ¤t->mm->mmap_sem;
1635 call_void_qop(q, wait_prepare, q);
1636 down_read(mmap_sem);
1637 call_void_qop(q, wait_finish, q);
1639 ret = __qbuf_userptr(vb, b);
1643 case V4L2_MEMORY_DMABUF:
1644 ret = __qbuf_dmabuf(vb, b);
1647 WARN(1, "Invalid queue type\n");
1652 dprintk(1, "buffer preparation failed: %d\n", ret);
1653 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1658 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1661 if (b->type != q->type) {
1662 dprintk(1, "%s: invalid buffer type\n", opname);
1666 if (b->index >= q->num_buffers) {
1667 dprintk(1, "%s: buffer index out of range\n", opname);
1671 if (q->bufs[b->index] == NULL) {
1672 /* Should never happen */
1673 dprintk(1, "%s: buffer is NULL\n", opname);
1677 if (b->memory != q->memory) {
1678 dprintk(1, "%s: invalid memory type\n", opname);
1682 return __verify_planes_array(q->bufs[b->index], b);
1686 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1687 * @q: videobuf2 queue
1688 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1691 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1693 * 1) verifies the passed buffer,
1694 * 2) calls buf_prepare callback in the driver (if provided), in which
1695 * driver-specific buffer initialization can be performed,
1697 * The return values from this function are intended to be directly returned
1698 * from vidioc_prepare_buf handler in driver.
1700 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1702 struct vb2_buffer *vb;
1705 if (vb2_fileio_is_active(q)) {
1706 dprintk(1, "file io in progress\n");
1710 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1714 vb = q->bufs[b->index];
1715 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1716 dprintk(1, "invalid buffer state %d\n",
1721 ret = __buf_prepare(vb, b);
1723 /* Fill buffer information for the userspace */
1724 __fill_v4l2_buffer(vb, b);
1726 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1730 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1733 * vb2_start_streaming() - Attempt to start streaming.
1734 * @q: videobuf2 queue
1736 * Attempt to start streaming. When this function is called there must be
1737 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1738 * number of buffers required for the DMA engine to function). If the
1739 * @start_streaming op fails it is supposed to return all the driver-owned
1740 * buffers back to vb2 in state QUEUED. Check if that happened and if
1741 * not warn and reclaim them forcefully.
1743 static int vb2_start_streaming(struct vb2_queue *q)
1745 struct vb2_buffer *vb;
1749 * If any buffers were queued before streamon,
1750 * we can now pass them to driver for processing.
1752 list_for_each_entry(vb, &q->queued_list, queued_entry)
1753 __enqueue_in_driver(vb);
1755 /* Tell the driver to start streaming */
1756 q->start_streaming_called = 1;
1757 ret = call_qop(q, start_streaming, q,
1758 atomic_read(&q->owned_by_drv_count));
1762 q->start_streaming_called = 0;
1764 dprintk(1, "driver refused to start streaming\n");
1765 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1769 * Forcefully reclaim buffers if the driver did not
1770 * correctly return them to vb2.
1772 for (i = 0; i < q->num_buffers; ++i) {
1774 if (vb->state == VB2_BUF_STATE_ACTIVE)
1775 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1777 /* Must be zero now */
1778 WARN_ON(atomic_read(&q->owned_by_drv_count));
1783 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1785 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1786 struct vb2_buffer *vb;
1791 vb = q->bufs[b->index];
1793 switch (vb->state) {
1794 case VB2_BUF_STATE_DEQUEUED:
1795 ret = __buf_prepare(vb, b);
1799 case VB2_BUF_STATE_PREPARED:
1801 case VB2_BUF_STATE_PREPARING:
1802 dprintk(1, "buffer still being prepared\n");
1805 dprintk(1, "invalid buffer state %d\n", vb->state);
1810 * Add to the queued buffers list, a buffer will stay on it until
1811 * dequeued in dqbuf.
1813 list_add_tail(&vb->queued_entry, &q->queued_list);
1815 vb->state = VB2_BUF_STATE_QUEUED;
1816 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1818 * For output buffers copy the timestamp if needed,
1819 * and the timecode field and flag if needed.
1821 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1822 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1823 vb->v4l2_buf.timestamp = b->timestamp;
1824 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1825 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1826 vb->v4l2_buf.timecode = b->timecode;
1830 * If already streaming, give the buffer to driver for processing.
1831 * If not, the buffer will be given to driver on next streamon.
1833 if (q->start_streaming_called)
1834 __enqueue_in_driver(vb);
1836 /* Fill buffer information for the userspace */
1837 __fill_v4l2_buffer(vb, b);
1840 * If streamon has been called, and we haven't yet called
1841 * start_streaming() since not enough buffers were queued, and
1842 * we now have reached the minimum number of queued buffers,
1843 * then we can finally call start_streaming().
1845 if (q->streaming && !q->start_streaming_called &&
1846 q->queued_count >= q->min_buffers_needed) {
1847 ret = vb2_start_streaming(q);
1852 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1857 * vb2_qbuf() - Queue a buffer from userspace
1858 * @q: videobuf2 queue
1859 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1862 * Should be called from vidioc_qbuf ioctl handler of a driver.
1864 * 1) verifies the passed buffer,
1865 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1866 * which driver-specific buffer initialization can be performed,
1867 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1868 * callback for processing.
1870 * The return values from this function are intended to be directly returned
1871 * from vidioc_qbuf handler in driver.
1873 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1875 if (vb2_fileio_is_active(q)) {
1876 dprintk(1, "file io in progress\n");
1880 return vb2_internal_qbuf(q, b);
1882 EXPORT_SYMBOL_GPL(vb2_qbuf);
1885 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1888 * Will sleep if required for nonblocking == false.
1890 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1893 * All operations on vb_done_list are performed under done_lock
1894 * spinlock protection. However, buffers may be removed from
1895 * it and returned to userspace only while holding both driver's
1896 * lock and the done_lock spinlock. Thus we can be sure that as
1897 * long as we hold the driver's lock, the list will remain not
1898 * empty if list_empty() check succeeds.
1904 if (!q->streaming) {
1905 dprintk(1, "streaming off, will not wait for buffers\n");
1910 dprintk(1, "Queue in error state, will not wait for buffers\n");
1914 if (!list_empty(&q->done_list)) {
1916 * Found a buffer that we were waiting for.
1922 dprintk(1, "nonblocking and no buffers to dequeue, "
1928 * We are streaming and blocking, wait for another buffer to
1929 * become ready or for streamoff. Driver's lock is released to
1930 * allow streamoff or qbuf to be called while waiting.
1932 call_void_qop(q, wait_prepare, q);
1935 * All locks have been released, it is safe to sleep now.
1937 dprintk(3, "will sleep waiting for buffers\n");
1938 ret = wait_event_interruptible(q->done_wq,
1939 !list_empty(&q->done_list) || !q->streaming ||
1943 * We need to reevaluate both conditions again after reacquiring
1944 * the locks or return an error if one occurred.
1946 call_void_qop(q, wait_finish, q);
1948 dprintk(1, "sleep was interrupted\n");
1956 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1958 * Will sleep if required for nonblocking == false.
1960 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1961 struct v4l2_buffer *b, int nonblocking)
1963 unsigned long flags;
1967 * Wait for at least one buffer to become available on the done_list.
1969 ret = __vb2_wait_for_done_vb(q, nonblocking);
1974 * Driver's lock has been held since we last verified that done_list
1975 * is not empty, so no need for another list_empty(done_list) check.
1977 spin_lock_irqsave(&q->done_lock, flags);
1978 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1980 * Only remove the buffer from done_list if v4l2_buffer can handle all
1983 ret = __verify_planes_array(*vb, b);
1985 list_del(&(*vb)->done_entry);
1986 spin_unlock_irqrestore(&q->done_lock, flags);
1992 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1993 * @q: videobuf2 queue
1995 * This function will wait until all buffers that have been given to the driver
1996 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1997 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1998 * taken, for example from stop_streaming() callback.
2000 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2002 if (!q->streaming) {
2003 dprintk(1, "streaming off, will not wait for buffers\n");
2007 if (q->start_streaming_called)
2008 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2011 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2014 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2016 static void __vb2_dqbuf(struct vb2_buffer *vb)
2018 struct vb2_queue *q = vb->vb2_queue;
2021 /* nothing to do if the buffer is already dequeued */
2022 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2025 vb->state = VB2_BUF_STATE_DEQUEUED;
2027 /* unmap DMABUF buffer */
2028 if (q->memory == V4L2_MEMORY_DMABUF)
2029 for (i = 0; i < vb->num_planes; ++i) {
2030 if (!vb->planes[i].dbuf_mapped)
2032 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2033 vb->planes[i].dbuf_mapped = 0;
2037 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2039 struct vb2_buffer *vb = NULL;
2042 if (b->type != q->type) {
2043 dprintk(1, "invalid buffer type\n");
2046 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2050 switch (vb->state) {
2051 case VB2_BUF_STATE_DONE:
2052 dprintk(3, "returning done buffer\n");
2054 case VB2_BUF_STATE_ERROR:
2055 dprintk(3, "returning done buffer with errors\n");
2058 dprintk(1, "invalid buffer state\n");
2062 call_void_vb_qop(vb, buf_finish, vb);
2064 /* Fill buffer information for the userspace */
2065 __fill_v4l2_buffer(vb, b);
2066 /* Remove from videobuf queue */
2067 list_del(&vb->queued_entry);
2069 /* go back to dequeued state */
2072 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2073 vb->v4l2_buf.index, vb->state);
2079 * vb2_dqbuf() - Dequeue a buffer to the userspace
2080 * @q: videobuf2 queue
2081 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2083 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2084 * buffers ready for dequeuing are present. Normally the driver
2085 * would be passing (file->f_flags & O_NONBLOCK) here
2087 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2089 * 1) verifies the passed buffer,
2090 * 2) calls buf_finish callback in the driver (if provided), in which
2091 * driver can perform any additional operations that may be required before
2092 * returning the buffer to userspace, such as cache sync,
2093 * 3) the buffer struct members are filled with relevant information for
2096 * The return values from this function are intended to be directly returned
2097 * from vidioc_dqbuf handler in driver.
2099 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2101 if (vb2_fileio_is_active(q)) {
2102 dprintk(1, "file io in progress\n");
2105 return vb2_internal_dqbuf(q, b, nonblocking);
2107 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2110 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2112 * Removes all queued buffers from driver's queue and all buffers queued by
2113 * userspace from videobuf's queue. Returns to state after reqbufs.
2115 static void __vb2_queue_cancel(struct vb2_queue *q)
2120 * Tell driver to stop all transactions and release all queued
2123 if (q->start_streaming_called)
2124 call_void_qop(q, stop_streaming, q);
2126 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2127 for (i = 0; i < q->num_buffers; ++i)
2128 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2129 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2130 /* Must be zero now */
2131 WARN_ON(atomic_read(&q->owned_by_drv_count));
2135 q->start_streaming_called = 0;
2136 q->queued_count = 0;
2140 * Remove all buffers from videobuf's list...
2142 INIT_LIST_HEAD(&q->queued_list);
2144 * ...and done list; userspace will not receive any buffers it
2145 * has not already dequeued before initiating cancel.
2147 INIT_LIST_HEAD(&q->done_list);
2148 atomic_set(&q->owned_by_drv_count, 0);
2149 wake_up_all(&q->done_wq);
2152 * Reinitialize all buffers for next use.
2153 * Make sure to call buf_finish for any queued buffers. Normally
2154 * that's done in dqbuf, but that's not going to happen when we
2155 * cancel the whole queue. Note: this code belongs here, not in
2156 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2157 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2158 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2160 for (i = 0; i < q->num_buffers; ++i) {
2161 struct vb2_buffer *vb = q->bufs[i];
2163 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2164 vb->state = VB2_BUF_STATE_PREPARED;
2165 call_void_vb_qop(vb, buf_finish, vb);
2171 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2175 if (type != q->type) {
2176 dprintk(1, "invalid stream type\n");
2181 dprintk(3, "already streaming\n");
2185 if (!q->num_buffers) {
2186 dprintk(1, "no buffers have been allocated\n");
2190 if (q->num_buffers < q->min_buffers_needed) {
2191 dprintk(1, "need at least %u allocated buffers\n",
2192 q->min_buffers_needed);
2197 * Tell driver to start streaming provided sufficient buffers
2200 if (q->queued_count >= q->min_buffers_needed) {
2201 ret = vb2_start_streaming(q);
2203 __vb2_queue_cancel(q);
2210 dprintk(3, "successful\n");
2215 * vb2_queue_error() - signal a fatal error on the queue
2216 * @q: videobuf2 queue
2218 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2219 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2220 * buffers will return -EIO.
2222 * The error flag will be cleared when cancelling the queue, either from
2223 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2224 * function before starting the stream, otherwise the error flag will remain set
2225 * until the queue is released when closing the device node.
2227 void vb2_queue_error(struct vb2_queue *q)
2231 wake_up_all(&q->done_wq);
2233 EXPORT_SYMBOL_GPL(vb2_queue_error);
2236 * vb2_streamon - start streaming
2237 * @q: videobuf2 queue
2238 * @type: type argument passed from userspace to vidioc_streamon handler
2240 * Should be called from vidioc_streamon handler of a driver.
2242 * 1) verifies current state
2243 * 2) passes any previously queued buffers to the driver and starts streaming
2245 * The return values from this function are intended to be directly returned
2246 * from vidioc_streamon handler in the driver.
2248 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2250 if (vb2_fileio_is_active(q)) {
2251 dprintk(1, "file io in progress\n");
2254 return vb2_internal_streamon(q, type);
2256 EXPORT_SYMBOL_GPL(vb2_streamon);
2258 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2260 if (type != q->type) {
2261 dprintk(1, "invalid stream type\n");
2266 * Cancel will pause streaming and remove all buffers from the driver
2267 * and videobuf, effectively returning control over them to userspace.
2269 * Note that we do this even if q->streaming == 0: if you prepare or
2270 * queue buffers, and then call streamoff without ever having called
2271 * streamon, you would still expect those buffers to be returned to
2272 * their normal dequeued state.
2274 __vb2_queue_cancel(q);
2276 dprintk(3, "successful\n");
2281 * vb2_streamoff - stop streaming
2282 * @q: videobuf2 queue
2283 * @type: type argument passed from userspace to vidioc_streamoff handler
2285 * Should be called from vidioc_streamoff handler of a driver.
2287 * 1) verifies current state,
2288 * 2) stop streaming and dequeues any queued buffers, including those previously
2289 * passed to the driver (after waiting for the driver to finish).
2291 * This call can be used for pausing playback.
2292 * The return values from this function are intended to be directly returned
2293 * from vidioc_streamoff handler in the driver
2295 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2297 if (vb2_fileio_is_active(q)) {
2298 dprintk(1, "file io in progress\n");
2301 return vb2_internal_streamoff(q, type);
2303 EXPORT_SYMBOL_GPL(vb2_streamoff);
2306 * __find_plane_by_offset() - find plane associated with the given offset off
2308 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2309 unsigned int *_buffer, unsigned int *_plane)
2311 struct vb2_buffer *vb;
2312 unsigned int buffer, plane;
2315 * Go over all buffers and their planes, comparing the given offset
2316 * with an offset assigned to each plane. If a match is found,
2317 * return its buffer and plane numbers.
2319 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2320 vb = q->bufs[buffer];
2322 for (plane = 0; plane < vb->num_planes; ++plane) {
2323 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2335 * vb2_expbuf() - Export a buffer as a file descriptor
2336 * @q: videobuf2 queue
2337 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2340 * The return values from this function are intended to be directly returned
2341 * from vidioc_expbuf handler in driver.
2343 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2345 struct vb2_buffer *vb = NULL;
2346 struct vb2_plane *vb_plane;
2348 struct dma_buf *dbuf;
2350 if (q->memory != V4L2_MEMORY_MMAP) {
2351 dprintk(1, "queue is not currently set up for mmap\n");
2355 if (!q->mem_ops->get_dmabuf) {
2356 dprintk(1, "queue does not support DMA buffer exporting\n");
2360 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2361 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2365 if (eb->type != q->type) {
2366 dprintk(1, "invalid buffer type\n");
2370 if (eb->index >= q->num_buffers) {
2371 dprintk(1, "buffer index out of range\n");
2375 vb = q->bufs[eb->index];
2377 if (eb->plane >= vb->num_planes) {
2378 dprintk(1, "buffer plane out of range\n");
2382 if (vb2_fileio_is_active(q)) {
2383 dprintk(1, "expbuf: file io in progress\n");
2387 vb_plane = &vb->planes[eb->plane];
2389 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2390 if (IS_ERR_OR_NULL(dbuf)) {
2391 dprintk(1, "failed to export buffer %d, plane %d\n",
2392 eb->index, eb->plane);
2396 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2398 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2399 eb->index, eb->plane, ret);
2404 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2405 eb->index, eb->plane, ret);
2410 EXPORT_SYMBOL_GPL(vb2_expbuf);
2413 * vb2_mmap() - map video buffers into application address space
2414 * @q: videobuf2 queue
2415 * @vma: vma passed to the mmap file operation handler in the driver
2417 * Should be called from mmap file operation handler of a driver.
2418 * This function maps one plane of one of the available video buffers to
2419 * userspace. To map whole video memory allocated on reqbufs, this function
2420 * has to be called once per each plane per each buffer previously allocated.
2422 * When the userspace application calls mmap, it passes to it an offset returned
2423 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2424 * a "cookie", which is then used to identify the plane to be mapped.
2425 * This function finds a plane with a matching offset and a mapping is performed
2426 * by the means of a provided memory operation.
2428 * The return values from this function are intended to be directly returned
2429 * from the mmap handler in driver.
2431 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2433 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2434 struct vb2_buffer *vb;
2435 unsigned int buffer = 0, plane = 0;
2437 unsigned long length;
2439 if (q->memory != V4L2_MEMORY_MMAP) {
2440 dprintk(1, "queue is not currently set up for mmap\n");
2445 * Check memory area access mode.
2447 if (!(vma->vm_flags & VM_SHARED)) {
2448 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2451 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2452 if (!(vma->vm_flags & VM_WRITE)) {
2453 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2457 if (!(vma->vm_flags & VM_READ)) {
2458 dprintk(1, "invalid vma flags, VM_READ needed\n");
2462 if (vb2_fileio_is_active(q)) {
2463 dprintk(1, "mmap: file io in progress\n");
2468 * Find the plane corresponding to the offset passed by userspace.
2470 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2474 vb = q->bufs[buffer];
2477 * MMAP requires page_aligned buffers.
2478 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2479 * so, we need to do the same here.
2481 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2482 if (length < (vma->vm_end - vma->vm_start)) {
2484 "MMAP invalid, as it would overflow buffer length\n");
2488 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2492 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2495 EXPORT_SYMBOL_GPL(vb2_mmap);
2498 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2501 unsigned long pgoff,
2502 unsigned long flags)
2504 unsigned long off = pgoff << PAGE_SHIFT;
2505 struct vb2_buffer *vb;
2506 unsigned int buffer, plane;
2509 if (q->memory != V4L2_MEMORY_MMAP) {
2510 dprintk(1, "queue is not currently set up for mmap\n");
2515 * Find the plane corresponding to the offset passed by userspace.
2517 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2521 vb = q->bufs[buffer];
2523 return (unsigned long)vb2_plane_vaddr(vb, plane);
2525 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2528 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2529 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2532 * vb2_poll() - implements poll userspace operation
2533 * @q: videobuf2 queue
2534 * @file: file argument passed to the poll file operation handler
2535 * @wait: wait argument passed to the poll file operation handler
2537 * This function implements poll file operation handler for a driver.
2538 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2539 * be informed that the file descriptor of a video device is available for
2541 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2542 * will be reported as available for writing.
2544 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2547 * The return values from this function are intended to be directly returned
2548 * from poll handler in driver.
2550 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2552 struct video_device *vfd = video_devdata(file);
2553 unsigned long req_events = poll_requested_events(wait);
2554 struct vb2_buffer *vb = NULL;
2555 unsigned int res = 0;
2556 unsigned long flags;
2558 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2559 struct v4l2_fh *fh = file->private_data;
2561 if (v4l2_event_pending(fh))
2563 else if (req_events & POLLPRI)
2564 poll_wait(file, &fh->wait, wait);
2567 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2569 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2573 * Start file I/O emulator only if streaming API has not been used yet.
2575 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2576 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2577 (req_events & (POLLIN | POLLRDNORM))) {
2578 if (__vb2_init_fileio(q, 1))
2579 return res | POLLERR;
2581 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2582 (req_events & (POLLOUT | POLLWRNORM))) {
2583 if (__vb2_init_fileio(q, 0))
2584 return res | POLLERR;
2586 * Write to OUTPUT queue can be done immediately.
2588 return res | POLLOUT | POLLWRNORM;
2593 * There is nothing to wait for if no buffer has been queued and the
2594 * queue isn't streaming, or if the error flag is set.
2596 if ((list_empty(&q->queued_list) && !vb2_is_streaming(q)) || q->error)
2597 return res | POLLERR;
2600 * For output streams you can write as long as there are fewer buffers
2601 * queued than there are buffers available.
2603 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2604 return res | POLLOUT | POLLWRNORM;
2606 if (list_empty(&q->done_list))
2607 poll_wait(file, &q->done_wq, wait);
2610 * Take first buffer available for dequeuing.
2612 spin_lock_irqsave(&q->done_lock, flags);
2613 if (!list_empty(&q->done_list))
2614 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2616 spin_unlock_irqrestore(&q->done_lock, flags);
2618 if (vb && (vb->state == VB2_BUF_STATE_DONE
2619 || vb->state == VB2_BUF_STATE_ERROR)) {
2620 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2621 res | POLLOUT | POLLWRNORM :
2622 res | POLLIN | POLLRDNORM;
2626 EXPORT_SYMBOL_GPL(vb2_poll);
2629 * vb2_queue_init() - initialize a videobuf2 queue
2630 * @q: videobuf2 queue; this structure should be allocated in driver
2632 * The vb2_queue structure should be allocated by the driver. The driver is
2633 * responsible of clearing it's content and setting initial values for some
2634 * required entries before calling this function.
2635 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2636 * to the struct vb2_queue description in include/media/videobuf2-core.h
2637 * for more information.
2639 int vb2_queue_init(struct vb2_queue *q)
2646 WARN_ON(!q->mem_ops) ||
2647 WARN_ON(!q->type) ||
2648 WARN_ON(!q->io_modes) ||
2649 WARN_ON(!q->ops->queue_setup) ||
2650 WARN_ON(!q->ops->buf_queue) ||
2651 WARN_ON(q->timestamp_flags &
2652 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2653 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2656 /* Warn that the driver should choose an appropriate timestamp type */
2657 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2658 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2660 INIT_LIST_HEAD(&q->queued_list);
2661 INIT_LIST_HEAD(&q->done_list);
2662 spin_lock_init(&q->done_lock);
2663 init_waitqueue_head(&q->done_wq);
2665 if (q->buf_struct_size == 0)
2666 q->buf_struct_size = sizeof(struct vb2_buffer);
2670 EXPORT_SYMBOL_GPL(vb2_queue_init);
2673 * vb2_queue_release() - stop streaming, release the queue and free memory
2674 * @q: videobuf2 queue
2676 * This function stops streaming and performs necessary clean ups, including
2677 * freeing video buffer memory. The driver is responsible for freeing
2678 * the vb2_queue structure itself.
2680 void vb2_queue_release(struct vb2_queue *q)
2682 __vb2_cleanup_fileio(q);
2683 __vb2_queue_cancel(q);
2684 __vb2_queue_free(q, q->num_buffers);
2686 EXPORT_SYMBOL_GPL(vb2_queue_release);
2689 * struct vb2_fileio_buf - buffer context used by file io emulator
2691 * vb2 provides a compatibility layer and emulator of file io (read and
2692 * write) calls on top of streaming API. This structure is used for
2693 * tracking context related to the buffers.
2695 struct vb2_fileio_buf {
2699 unsigned int queued:1;
2703 * struct vb2_fileio_data - queue context used by file io emulator
2705 * @cur_index: the index of the buffer currently being read from or
2706 * written to. If equal to q->num_buffers then a new buffer
2708 * @initial_index: in the read() case all buffers are queued up immediately
2709 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2710 * buffers. However, in the write() case no buffers are initially
2711 * queued, instead whenever a buffer is full it is queued up by
2712 * __vb2_perform_fileio(). Only once all available buffers have
2713 * been queued up will __vb2_perform_fileio() start to dequeue
2714 * buffers. This means that initially __vb2_perform_fileio()
2715 * needs to know what buffer index to use when it is queuing up
2716 * the buffers for the first time. That initial index is stored
2717 * in this field. Once it is equal to q->num_buffers all
2718 * available buffers have been queued and __vb2_perform_fileio()
2719 * should start the normal dequeue/queue cycle.
2721 * vb2 provides a compatibility layer and emulator of file io (read and
2722 * write) calls on top of streaming API. For proper operation it required
2723 * this structure to save the driver state between each call of the read
2724 * or write function.
2726 struct vb2_fileio_data {
2727 struct v4l2_requestbuffers req;
2728 struct v4l2_plane p;
2729 struct v4l2_buffer b;
2730 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2731 unsigned int cur_index;
2732 unsigned int initial_index;
2733 unsigned int q_count;
2734 unsigned int dq_count;
2739 * __vb2_init_fileio() - initialize file io emulator
2740 * @q: videobuf2 queue
2741 * @read: mode selector (1 means read, 0 means write)
2743 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2745 struct vb2_fileio_data *fileio;
2747 unsigned int count = 0;
2752 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2753 (!read && !(q->io_modes & VB2_WRITE))))
2757 * Check if device supports mapping buffers to kernel virtual space.
2759 if (!q->mem_ops->vaddr)
2763 * Check if streaming api has not been already activated.
2765 if (q->streaming || q->num_buffers > 0)
2769 * Start with count 1, driver can increase it in queue_setup()
2773 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2774 (read) ? "read" : "write", count, q->io_flags);
2776 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2780 fileio->flags = q->io_flags;
2783 * Request buffers and use MMAP type to force driver
2784 * to allocate buffers by itself.
2786 fileio->req.count = count;
2787 fileio->req.memory = V4L2_MEMORY_MMAP;
2788 fileio->req.type = q->type;
2790 ret = __reqbufs(q, &fileio->req);
2795 * Check if plane_count is correct
2796 * (multiplane buffers are not supported).
2798 if (q->bufs[0]->num_planes != 1) {
2804 * Get kernel address of each buffer.
2806 for (i = 0; i < q->num_buffers; i++) {
2807 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2808 if (fileio->bufs[i].vaddr == NULL) {
2812 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2816 * Read mode requires pre queuing of all buffers.
2819 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2822 * Queue all buffers.
2824 for (i = 0; i < q->num_buffers; i++) {
2825 struct v4l2_buffer *b = &fileio->b;
2827 memset(b, 0, sizeof(*b));
2829 if (is_multiplanar) {
2830 memset(&fileio->p, 0, sizeof(fileio->p));
2831 b->m.planes = &fileio->p;
2834 b->memory = q->memory;
2836 ret = vb2_internal_qbuf(q, b);
2839 fileio->bufs[i].queued = 1;
2842 * All buffers have been queued, so mark that by setting
2843 * initial_index to q->num_buffers
2845 fileio->initial_index = q->num_buffers;
2846 fileio->cur_index = q->num_buffers;
2852 ret = vb2_internal_streamon(q, q->type);
2859 fileio->req.count = 0;
2860 __reqbufs(q, &fileio->req);
2869 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2870 * @q: videobuf2 queue
2872 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2874 struct vb2_fileio_data *fileio = q->fileio;
2877 vb2_internal_streamoff(q, q->type);
2879 fileio->req.count = 0;
2880 vb2_reqbufs(q, &fileio->req);
2882 dprintk(3, "file io emulator closed\n");
2888 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2889 * @q: videobuf2 queue
2890 * @data: pointed to target userspace buffer
2891 * @count: number of bytes to read or write
2892 * @ppos: file handle position tracking pointer
2893 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2894 * @read: access mode selector (1 means read, 0 means write)
2896 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2897 loff_t *ppos, int nonblock, int read)
2899 struct vb2_fileio_data *fileio;
2900 struct vb2_fileio_buf *buf;
2901 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2903 * When using write() to write data to an output video node the vb2 core
2904 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2905 * else is able to provide this information with the write() operation.
2907 bool set_timestamp = !read &&
2908 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2909 V4L2_BUF_FLAG_TIMESTAMP_COPY;
2912 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2913 read ? "read" : "write", (long)*ppos, count,
2914 nonblock ? "non" : "");
2920 * Initialize emulator on first call.
2922 if (!vb2_fileio_is_active(q)) {
2923 ret = __vb2_init_fileio(q, read);
2924 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2931 * Check if we need to dequeue the buffer.
2933 index = fileio->cur_index;
2934 if (index >= q->num_buffers) {
2936 * Call vb2_dqbuf to get buffer back.
2938 memset(&fileio->b, 0, sizeof(fileio->b));
2939 fileio->b.type = q->type;
2940 fileio->b.memory = q->memory;
2941 if (is_multiplanar) {
2942 memset(&fileio->p, 0, sizeof(fileio->p));
2943 fileio->b.m.planes = &fileio->p;
2944 fileio->b.length = 1;
2946 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
2947 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2950 fileio->dq_count += 1;
2952 fileio->cur_index = index = fileio->b.index;
2953 buf = &fileio->bufs[index];
2956 * Get number of bytes filled by the driver
2960 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2961 : vb2_plane_size(q->bufs[index], 0);
2963 buf = &fileio->bufs[index];
2967 * Limit count on last few bytes of the buffer.
2969 if (buf->pos + count > buf->size) {
2970 count = buf->size - buf->pos;
2971 dprintk(5, "reducing read count: %zd\n", count);
2975 * Transfer data to userspace.
2977 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2978 count, index, buf->pos);
2980 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2982 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2984 dprintk(3, "error copying data\n");
2995 * Queue next buffer if required.
2997 if (buf->pos == buf->size ||
2998 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
3000 * Check if this is the last buffer to read.
3002 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
3003 fileio->dq_count == 1) {
3004 dprintk(3, "read limit reached\n");
3005 return __vb2_cleanup_fileio(q);
3009 * Call vb2_qbuf and give buffer to the driver.
3011 memset(&fileio->b, 0, sizeof(fileio->b));
3012 fileio->b.type = q->type;
3013 fileio->b.memory = q->memory;
3014 fileio->b.index = index;
3015 fileio->b.bytesused = buf->pos;
3016 if (is_multiplanar) {
3017 memset(&fileio->p, 0, sizeof(fileio->p));
3018 fileio->p.bytesused = buf->pos;
3019 fileio->b.m.planes = &fileio->p;
3020 fileio->b.length = 1;
3023 v4l2_get_timestamp(&fileio->b.timestamp);
3024 ret = vb2_internal_qbuf(q, &fileio->b);
3025 dprintk(5, "vb2_dbuf result: %d\n", ret);
3030 * Buffer has been queued, update the status
3034 buf->size = vb2_plane_size(q->bufs[index], 0);
3035 fileio->q_count += 1;
3037 * If we are queuing up buffers for the first time, then
3038 * increase initial_index by one.
3040 if (fileio->initial_index < q->num_buffers)
3041 fileio->initial_index++;
3043 * The next buffer to use is either a buffer that's going to be
3044 * queued for the first time (initial_index < q->num_buffers)
3045 * or it is equal to q->num_buffers, meaning that the next
3046 * time we need to dequeue a buffer since we've now queued up
3047 * all the 'first time' buffers.
3049 fileio->cur_index = fileio->initial_index;
3053 * Return proper number of bytes processed.
3060 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3061 loff_t *ppos, int nonblocking)
3063 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3065 EXPORT_SYMBOL_GPL(vb2_read);
3067 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3068 loff_t *ppos, int nonblocking)
3070 return __vb2_perform_fileio(q, (char __user *) data, count,
3071 ppos, nonblocking, 0);
3073 EXPORT_SYMBOL_GPL(vb2_write);
3075 struct vb2_threadio_data {
3076 struct task_struct *thread;
3082 static int vb2_thread(void *data)
3084 struct vb2_queue *q = data;
3085 struct vb2_threadio_data *threadio = q->threadio;
3086 struct vb2_fileio_data *fileio = q->fileio;
3087 bool set_timestamp = false;
3092 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3093 prequeue = q->num_buffers;
3095 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3096 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3102 struct vb2_buffer *vb;
3105 * Call vb2_dqbuf to get buffer back.
3107 memset(&fileio->b, 0, sizeof(fileio->b));
3108 fileio->b.type = q->type;
3109 fileio->b.memory = q->memory;
3111 fileio->b.index = index++;
3114 call_void_qop(q, wait_finish, q);
3115 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3116 call_void_qop(q, wait_prepare, q);
3117 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3125 vb = q->bufs[fileio->b.index];
3126 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3127 ret = threadio->fnc(vb, threadio->priv);
3130 call_void_qop(q, wait_finish, q);
3132 v4l2_get_timestamp(&fileio->b.timestamp);
3133 ret = vb2_internal_qbuf(q, &fileio->b);
3134 call_void_qop(q, wait_prepare, q);
3139 /* Hmm, linux becomes *very* unhappy without this ... */
3140 while (!kthread_should_stop()) {
3141 set_current_state(TASK_INTERRUPTIBLE);
3148 * This function should not be used for anything else but the videobuf2-dvb
3149 * support. If you think you have another good use-case for this, then please
3150 * contact the linux-media mailinglist first.
3152 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3153 const char *thread_name)
3155 struct vb2_threadio_data *threadio;
3162 if (WARN_ON(q->fileio))
3165 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3166 if (threadio == NULL)
3168 threadio->fnc = fnc;
3169 threadio->priv = priv;
3171 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3172 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3175 q->threadio = threadio;
3176 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3177 if (IS_ERR(threadio->thread)) {
3178 ret = PTR_ERR(threadio->thread);
3179 threadio->thread = NULL;
3185 __vb2_cleanup_fileio(q);
3190 EXPORT_SYMBOL_GPL(vb2_thread_start);
3192 int vb2_thread_stop(struct vb2_queue *q)
3194 struct vb2_threadio_data *threadio = q->threadio;
3195 struct vb2_fileio_data *fileio = q->fileio;
3198 if (threadio == NULL)
3200 call_void_qop(q, wait_finish, q);
3201 threadio->stop = true;
3202 vb2_internal_streamoff(q, q->type);
3203 call_void_qop(q, wait_prepare, q);
3205 fileio->req.count = 0;
3206 vb2_reqbufs(q, &fileio->req);
3208 err = kthread_stop(threadio->thread);
3209 threadio->thread = NULL;
3215 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3218 * The following functions are not part of the vb2 core API, but are helper
3219 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3220 * and struct vb2_ops.
3221 * They contain boilerplate code that most if not all drivers have to do
3222 * and so they simplify the driver code.
3225 /* The queue is busy if there is a owner and you are not that owner. */
3226 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3228 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3231 /* vb2 ioctl helpers */
3233 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3234 struct v4l2_requestbuffers *p)
3236 struct video_device *vdev = video_devdata(file);
3237 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3241 if (vb2_queue_is_busy(vdev, file))
3243 res = __reqbufs(vdev->queue, p);
3244 /* If count == 0, then the owner has released all buffers and he
3245 is no longer owner of the queue. Otherwise we have a new owner. */
3247 vdev->queue->owner = p->count ? file->private_data : NULL;
3250 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3252 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3253 struct v4l2_create_buffers *p)
3255 struct video_device *vdev = video_devdata(file);
3256 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3258 p->index = vdev->queue->num_buffers;
3259 /* If count == 0, then just check if memory and type are valid.
3260 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3262 return res != -EBUSY ? res : 0;
3265 if (vb2_queue_is_busy(vdev, file))
3267 res = __create_bufs(vdev->queue, p);
3269 vdev->queue->owner = file->private_data;
3272 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3274 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3275 struct v4l2_buffer *p)
3277 struct video_device *vdev = video_devdata(file);
3279 if (vb2_queue_is_busy(vdev, file))
3281 return vb2_prepare_buf(vdev->queue, p);
3283 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3285 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3287 struct video_device *vdev = video_devdata(file);
3289 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3290 return vb2_querybuf(vdev->queue, p);
3292 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3294 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3296 struct video_device *vdev = video_devdata(file);
3298 if (vb2_queue_is_busy(vdev, file))
3300 return vb2_qbuf(vdev->queue, p);
3302 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3304 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3306 struct video_device *vdev = video_devdata(file);
3308 if (vb2_queue_is_busy(vdev, file))
3310 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3312 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3314 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3316 struct video_device *vdev = video_devdata(file);
3318 if (vb2_queue_is_busy(vdev, file))
3320 return vb2_streamon(vdev->queue, i);
3322 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3324 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3326 struct video_device *vdev = video_devdata(file);
3328 if (vb2_queue_is_busy(vdev, file))
3330 return vb2_streamoff(vdev->queue, i);
3332 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3334 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3336 struct video_device *vdev = video_devdata(file);
3338 if (vb2_queue_is_busy(vdev, file))
3340 return vb2_expbuf(vdev->queue, p);
3342 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3344 /* v4l2_file_operations helpers */
3346 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3348 struct video_device *vdev = video_devdata(file);
3349 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3352 if (lock && mutex_lock_interruptible(lock))
3353 return -ERESTARTSYS;
3354 err = vb2_mmap(vdev->queue, vma);
3359 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3361 int _vb2_fop_release(struct file *file, struct mutex *lock)
3363 struct video_device *vdev = video_devdata(file);
3365 if (file->private_data == vdev->queue->owner) {
3368 vb2_queue_release(vdev->queue);
3369 vdev->queue->owner = NULL;
3373 return v4l2_fh_release(file);
3375 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3377 int vb2_fop_release(struct file *file)
3379 struct video_device *vdev = video_devdata(file);
3380 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3382 return _vb2_fop_release(file, lock);
3384 EXPORT_SYMBOL_GPL(vb2_fop_release);
3386 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3387 size_t count, loff_t *ppos)
3389 struct video_device *vdev = video_devdata(file);
3390 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3393 if (lock && mutex_lock_interruptible(lock))
3394 return -ERESTARTSYS;
3395 if (vb2_queue_is_busy(vdev, file))
3397 err = vb2_write(vdev->queue, buf, count, ppos,
3398 file->f_flags & O_NONBLOCK);
3399 if (vdev->queue->fileio)
3400 vdev->queue->owner = file->private_data;
3406 EXPORT_SYMBOL_GPL(vb2_fop_write);
3408 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3409 size_t count, loff_t *ppos)
3411 struct video_device *vdev = video_devdata(file);
3412 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3415 if (lock && mutex_lock_interruptible(lock))
3416 return -ERESTARTSYS;
3417 if (vb2_queue_is_busy(vdev, file))
3419 err = vb2_read(vdev->queue, buf, count, ppos,
3420 file->f_flags & O_NONBLOCK);
3421 if (vdev->queue->fileio)
3422 vdev->queue->owner = file->private_data;
3428 EXPORT_SYMBOL_GPL(vb2_fop_read);
3430 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3432 struct video_device *vdev = video_devdata(file);
3433 struct vb2_queue *q = vdev->queue;
3434 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3435 unsigned long req_events = poll_requested_events(wait);
3438 bool must_lock = false;
3440 /* Try to be smart: only lock if polling might start fileio,
3441 otherwise locking will only introduce unwanted delays. */
3442 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
3443 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
3444 (req_events & (POLLIN | POLLRDNORM)))
3446 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
3447 (req_events & (POLLOUT | POLLWRNORM)))
3451 /* If locking is needed, but this helper doesn't know how, then you
3452 shouldn't be using this helper but you should write your own. */
3453 WARN_ON(must_lock && !lock);
3455 if (must_lock && lock && mutex_lock_interruptible(lock))
3460 res = vb2_poll(vdev->queue, file, wait);
3462 /* If fileio was started, then we have a new queue owner. */
3463 if (must_lock && !fileio && q->fileio)
3464 q->owner = file->private_data;
3465 if (must_lock && lock)
3469 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3472 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3473 unsigned long len, unsigned long pgoff, unsigned long flags)
3475 struct video_device *vdev = video_devdata(file);
3476 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3479 if (lock && mutex_lock_interruptible(lock))
3480 return -ERESTARTSYS;
3481 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3486 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3489 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3491 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3493 mutex_unlock(vq->lock);
3495 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3497 void vb2_ops_wait_finish(struct vb2_queue *vq)
3499 mutex_lock(vq->lock);
3501 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3503 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3504 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3505 MODULE_LICENSE("GPL");