2 * videobuf2-core.c - V4L2 driver helper framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
34 module_param(debug, int, 0644);
36 #define dprintk(level, fmt, arg...) \
39 pr_info("vb2: %s: " fmt, __func__, ## arg); \
42 #ifdef CONFIG_VIDEO_ADV_DEBUG
45 * If advanced debugging is on, then count how often each op is called
46 * successfully, which can either be per-buffer or per-queue.
48 * This makes it easy to check that the 'init' and 'cleanup'
49 * (and variations thereof) stay balanced.
52 #define log_memop(vb, op) \
53 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
54 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
55 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
57 #define call_memop(vb, op, args...) \
59 struct vb2_queue *_q = (vb)->vb2_queue; \
63 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
65 (vb)->cnt_mem_ ## op++; \
69 #define call_ptr_memop(vb, op, args...) \
71 struct vb2_queue *_q = (vb)->vb2_queue; \
75 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
76 if (!IS_ERR_OR_NULL(ptr)) \
77 (vb)->cnt_mem_ ## op++; \
81 #define call_void_memop(vb, op, args...) \
83 struct vb2_queue *_q = (vb)->vb2_queue; \
86 if (_q->mem_ops->op) \
87 _q->mem_ops->op(args); \
88 (vb)->cnt_mem_ ## op++; \
91 #define log_qop(q, op) \
92 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
93 (q)->ops->op ? "" : " (nop)")
95 #define call_qop(q, op, args...) \
100 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
106 #define call_void_qop(q, op, args...) \
110 (q)->ops->op(args); \
114 #define log_vb_qop(vb, op, args...) \
115 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
116 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
117 (vb)->vb2_queue->ops->op ? "" : " (nop)")
119 #define call_vb_qop(vb, op, args...) \
123 log_vb_qop(vb, op); \
124 err = (vb)->vb2_queue->ops->op ? \
125 (vb)->vb2_queue->ops->op(args) : 0; \
127 (vb)->cnt_ ## op++; \
131 #define call_void_vb_qop(vb, op, args...) \
133 log_vb_qop(vb, op); \
134 if ((vb)->vb2_queue->ops->op) \
135 (vb)->vb2_queue->ops->op(args); \
136 (vb)->cnt_ ## op++; \
141 #define call_memop(vb, op, args...) \
142 ((vb)->vb2_queue->mem_ops->op ? \
143 (vb)->vb2_queue->mem_ops->op(args) : 0)
145 #define call_ptr_memop(vb, op, args...) \
146 ((vb)->vb2_queue->mem_ops->op ? \
147 (vb)->vb2_queue->mem_ops->op(args) : NULL)
149 #define call_void_memop(vb, op, args...) \
151 if ((vb)->vb2_queue->mem_ops->op) \
152 (vb)->vb2_queue->mem_ops->op(args); \
155 #define call_qop(q, op, args...) \
156 ((q)->ops->op ? (q)->ops->op(args) : 0)
158 #define call_void_qop(q, op, args...) \
161 (q)->ops->op(args); \
164 #define call_vb_qop(vb, op, args...) \
165 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
167 #define call_void_vb_qop(vb, op, args...) \
169 if ((vb)->vb2_queue->ops->op) \
170 (vb)->vb2_queue->ops->op(args); \
175 /* Flags that are set by the vb2 core */
176 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
177 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
178 V4L2_BUF_FLAG_PREPARED | \
179 V4L2_BUF_FLAG_TIMESTAMP_MASK)
180 /* Output buffer flags that should be passed on to the driver */
181 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
182 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
184 static void __vb2_queue_cancel(struct vb2_queue *q);
187 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
189 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
191 struct vb2_queue *q = vb->vb2_queue;
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 mutex_lock(&q->mmap_lock);
886 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
887 mutex_unlock(&q->mmap_lock);
888 dprintk(1, "memory in use, cannot free\n");
893 * Call queue_cancel to clean up any buffers in the PREPARED or
894 * QUEUED state which is possible if buffers were prepared or
895 * queued without ever calling STREAMON.
897 __vb2_queue_cancel(q);
898 ret = __vb2_queue_free(q, q->num_buffers);
899 mutex_unlock(&q->mmap_lock);
904 * In case of REQBUFS(0) return immediately without calling
905 * driver's queue_setup() callback and allocating resources.
912 * Make sure the requested values and current defaults are sane.
914 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
915 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
916 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
917 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
918 q->memory = req->memory;
921 * Ask the driver how many buffers and planes per buffer it requires.
922 * Driver also sets the size and allocator context for each plane.
924 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
925 q->plane_sizes, q->alloc_ctx);
929 /* Finally, allocate buffers and video memory */
930 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
931 if (allocated_buffers == 0) {
932 dprintk(1, "memory allocation failed\n");
937 * There is no point in continuing if we can't allocate the minimum
938 * number of buffers needed by this vb2_queue.
940 if (allocated_buffers < q->min_buffers_needed)
944 * Check if driver can handle the allocated number of buffers.
946 if (!ret && allocated_buffers < num_buffers) {
947 num_buffers = allocated_buffers;
949 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
950 &num_planes, q->plane_sizes, q->alloc_ctx);
952 if (!ret && allocated_buffers < num_buffers)
956 * Either the driver has accepted a smaller number of buffers,
957 * or .queue_setup() returned an error
961 mutex_lock(&q->mmap_lock);
962 q->num_buffers = allocated_buffers;
966 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
967 * from q->num_buffers.
969 __vb2_queue_free(q, allocated_buffers);
970 mutex_unlock(&q->mmap_lock);
973 mutex_unlock(&q->mmap_lock);
976 * Return the number of successfully allocated buffers
979 req->count = allocated_buffers;
980 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
986 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
988 * @q: videobuf2 queue
989 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
991 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
993 int ret = __verify_memory_type(q, req->memory, req->type);
995 return ret ? ret : __reqbufs(q, req);
997 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1000 * __create_bufs() - Allocate buffers and any required auxiliary structs
1001 * @q: videobuf2 queue
1002 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1005 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1007 * 1) verifies parameter sanity
1008 * 2) calls the .queue_setup() queue operation
1009 * 3) performs any necessary memory allocations
1011 * The return values from this function are intended to be directly returned
1012 * from vidioc_create_bufs handler in driver.
1014 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1016 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1019 if (q->num_buffers == VIDEO_MAX_FRAME) {
1020 dprintk(1, "maximum number of buffers already allocated\n");
1024 if (!q->num_buffers) {
1025 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1026 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1027 q->memory = create->memory;
1028 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1031 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1034 * Ask the driver, whether the requested number of buffers, planes per
1035 * buffer and their sizes are acceptable
1037 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1038 &num_planes, q->plane_sizes, q->alloc_ctx);
1042 /* Finally, allocate buffers and video memory */
1043 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1045 if (allocated_buffers == 0) {
1046 dprintk(1, "memory allocation failed\n");
1051 * Check if driver can handle the so far allocated number of buffers.
1053 if (allocated_buffers < num_buffers) {
1054 num_buffers = allocated_buffers;
1057 * q->num_buffers contains the total number of buffers, that the
1058 * queue driver has set up
1060 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1061 &num_planes, q->plane_sizes, q->alloc_ctx);
1063 if (!ret && allocated_buffers < num_buffers)
1067 * Either the driver has accepted a smaller number of buffers,
1068 * or .queue_setup() returned an error
1072 mutex_lock(&q->mmap_lock);
1073 q->num_buffers += allocated_buffers;
1077 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1078 * from q->num_buffers.
1080 __vb2_queue_free(q, allocated_buffers);
1081 mutex_unlock(&q->mmap_lock);
1084 mutex_unlock(&q->mmap_lock);
1087 * Return the number of successfully allocated buffers
1090 create->count = allocated_buffers;
1096 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1097 * memory and type values.
1098 * @q: videobuf2 queue
1099 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1102 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1104 int ret = __verify_memory_type(q, create->memory, create->format.type);
1106 create->index = q->num_buffers;
1107 if (create->count == 0)
1108 return ret != -EBUSY ? ret : 0;
1109 return ret ? ret : __create_bufs(q, create);
1111 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1114 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1115 * @vb: vb2_buffer to which the plane in question belongs to
1116 * @plane_no: plane number for which the address is to be returned
1118 * This function returns a kernel virtual address of a given plane if
1119 * such a mapping exist, NULL otherwise.
1121 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1123 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1126 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1129 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1132 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1133 * @vb: vb2_buffer to which the plane in question belongs to
1134 * @plane_no: plane number for which the cookie is to be returned
1136 * This function returns an allocator specific cookie for a given plane if
1137 * available, NULL otherwise. The allocator should provide some simple static
1138 * inline function, which would convert this cookie to the allocator specific
1139 * type that can be used directly by the driver to access the buffer. This can
1140 * be for example physical address, pointer to scatter list or IOMMU mapping.
1142 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1144 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1147 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1149 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1152 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1153 * @vb: vb2_buffer returned from the driver
1154 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1155 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1156 * If start_streaming fails then it should return buffers with state
1157 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1159 * This function should be called by the driver after a hardware operation on
1160 * a buffer is finished and the buffer may be returned to userspace. The driver
1161 * cannot use this buffer anymore until it is queued back to it by videobuf
1162 * by the means of buf_queue callback. Only buffers previously queued to the
1163 * driver by buf_queue can be passed to this function.
1165 * While streaming a buffer can only be returned in state DONE or ERROR.
1166 * The start_streaming op can also return them in case the DMA engine cannot
1167 * be started for some reason. In that case the buffers should be returned with
1170 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1172 struct vb2_queue *q = vb->vb2_queue;
1173 unsigned long flags;
1176 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1179 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1180 state != VB2_BUF_STATE_ERROR &&
1181 state != VB2_BUF_STATE_QUEUED))
1182 state = VB2_BUF_STATE_ERROR;
1184 #ifdef CONFIG_VIDEO_ADV_DEBUG
1186 * Although this is not a callback, it still does have to balance
1187 * with the buf_queue op. So update this counter manually.
1191 dprintk(4, "done processing on buffer %d, state: %d\n",
1192 vb->v4l2_buf.index, state);
1195 for (plane = 0; plane < vb->num_planes; ++plane)
1196 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1198 /* Add the buffer to the done buffers list */
1199 spin_lock_irqsave(&q->done_lock, flags);
1201 if (state != VB2_BUF_STATE_QUEUED)
1202 list_add_tail(&vb->done_entry, &q->done_list);
1203 atomic_dec(&q->owned_by_drv_count);
1204 spin_unlock_irqrestore(&q->done_lock, flags);
1206 if (state == VB2_BUF_STATE_QUEUED)
1209 /* Inform any processes that may be waiting for buffers */
1210 wake_up(&q->done_wq);
1212 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1215 * vb2_discard_done() - discard all buffers marked as DONE
1216 * @q: videobuf2 queue
1218 * This function is intended to be used with suspend/resume operations. It
1219 * discards all 'done' buffers as they would be too old to be requested after
1222 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1223 * delayed works before calling this function to make sure no buffer will be
1224 * touched by the driver and/or hardware.
1226 void vb2_discard_done(struct vb2_queue *q)
1228 struct vb2_buffer *vb;
1229 unsigned long flags;
1231 spin_lock_irqsave(&q->done_lock, flags);
1232 list_for_each_entry(vb, &q->done_list, done_entry)
1233 vb->state = VB2_BUF_STATE_ERROR;
1234 spin_unlock_irqrestore(&q->done_lock, flags);
1236 EXPORT_SYMBOL_GPL(vb2_discard_done);
1239 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1240 * v4l2_buffer by the userspace. The caller has already verified that struct
1241 * v4l2_buffer has a valid number of planes.
1243 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1244 struct v4l2_plane *v4l2_planes)
1248 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1249 if (b->memory == V4L2_MEMORY_USERPTR) {
1250 for (plane = 0; plane < vb->num_planes; ++plane) {
1251 v4l2_planes[plane].m.userptr =
1252 b->m.planes[plane].m.userptr;
1253 v4l2_planes[plane].length =
1254 b->m.planes[plane].length;
1257 if (b->memory == V4L2_MEMORY_DMABUF) {
1258 for (plane = 0; plane < vb->num_planes; ++plane) {
1259 v4l2_planes[plane].m.fd =
1260 b->m.planes[plane].m.fd;
1261 v4l2_planes[plane].length =
1262 b->m.planes[plane].length;
1266 /* Fill in driver-provided information for OUTPUT types */
1267 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1269 * Will have to go up to b->length when API starts
1270 * accepting variable number of planes.
1272 * If bytesused == 0 for the output buffer, then fall
1273 * back to the full buffer size. In that case
1274 * userspace clearly never bothered to set it and
1275 * it's a safe assumption that they really meant to
1276 * use the full plane sizes.
1278 for (plane = 0; plane < vb->num_planes; ++plane) {
1279 struct v4l2_plane *pdst = &v4l2_planes[plane];
1280 struct v4l2_plane *psrc = &b->m.planes[plane];
1282 pdst->bytesused = psrc->bytesused ?
1283 psrc->bytesused : pdst->length;
1284 pdst->data_offset = psrc->data_offset;
1289 * Single-planar buffers do not use planes array,
1290 * so fill in relevant v4l2_buffer struct fields instead.
1291 * In videobuf we use our internal V4l2_planes struct for
1292 * single-planar buffers as well, for simplicity.
1294 * If bytesused == 0 for the output buffer, then fall back
1295 * to the full buffer size as that's a sensible default.
1297 if (b->memory == V4L2_MEMORY_USERPTR) {
1298 v4l2_planes[0].m.userptr = b->m.userptr;
1299 v4l2_planes[0].length = b->length;
1302 if (b->memory == V4L2_MEMORY_DMABUF) {
1303 v4l2_planes[0].m.fd = b->m.fd;
1304 v4l2_planes[0].length = b->length;
1307 if (V4L2_TYPE_IS_OUTPUT(b->type))
1308 v4l2_planes[0].bytesused = b->bytesused ?
1309 b->bytesused : v4l2_planes[0].length;
1311 v4l2_planes[0].bytesused = 0;
1315 /* Zero flags that the vb2 core handles */
1316 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1317 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1318 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1320 * Non-COPY timestamps and non-OUTPUT queues will get
1321 * their timestamp and timestamp source flags from the
1324 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1327 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1329 * For output buffers mask out the timecode flag:
1330 * this will be handled later in vb2_internal_qbuf().
1331 * The 'field' is valid metadata for this output buffer
1332 * and so that needs to be copied here.
1334 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1335 vb->v4l2_buf.field = b->field;
1337 /* Zero any output buffer flags as this is a capture buffer */
1338 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1343 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1345 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1347 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1348 return call_vb_qop(vb, buf_prepare, vb);
1352 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1354 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1356 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1357 struct vb2_queue *q = vb->vb2_queue;
1361 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1362 bool reacquired = vb->planes[0].mem_priv == NULL;
1364 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1365 /* Copy relevant information provided by the userspace */
1366 __fill_vb2_buffer(vb, b, planes);
1368 for (plane = 0; plane < vb->num_planes; ++plane) {
1369 /* Skip the plane if already verified */
1370 if (vb->v4l2_planes[plane].m.userptr &&
1371 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1372 && vb->v4l2_planes[plane].length == planes[plane].length)
1375 dprintk(3, "userspace address for plane %d changed, "
1376 "reacquiring memory\n", plane);
1378 /* Check if the provided plane buffer is large enough */
1379 if (planes[plane].length < q->plane_sizes[plane]) {
1380 dprintk(1, "provided buffer size %u is less than "
1381 "setup size %u for plane %d\n",
1382 planes[plane].length,
1383 q->plane_sizes[plane], plane);
1388 /* Release previously acquired memory if present */
1389 if (vb->planes[plane].mem_priv) {
1392 call_void_vb_qop(vb, buf_cleanup, vb);
1394 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1397 vb->planes[plane].mem_priv = NULL;
1398 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1400 /* Acquire each plane's memory */
1401 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1402 planes[plane].m.userptr,
1403 planes[plane].length, write);
1404 if (IS_ERR_OR_NULL(mem_priv)) {
1405 dprintk(1, "failed acquiring userspace "
1406 "memory for plane %d\n", plane);
1407 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1410 vb->planes[plane].mem_priv = mem_priv;
1414 * Now that everything is in order, copy relevant information
1415 * provided by userspace.
1417 for (plane = 0; plane < vb->num_planes; ++plane)
1418 vb->v4l2_planes[plane] = planes[plane];
1422 * One or more planes changed, so we must call buf_init to do
1423 * the driver-specific initialization on the newly acquired
1424 * buffer, if provided.
1426 ret = call_vb_qop(vb, buf_init, vb);
1428 dprintk(1, "buffer initialization failed\n");
1433 ret = call_vb_qop(vb, buf_prepare, vb);
1435 dprintk(1, "buffer preparation failed\n");
1436 call_void_vb_qop(vb, buf_cleanup, vb);
1442 /* In case of errors, release planes that were already acquired */
1443 for (plane = 0; plane < vb->num_planes; ++plane) {
1444 if (vb->planes[plane].mem_priv)
1445 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1446 vb->planes[plane].mem_priv = NULL;
1447 vb->v4l2_planes[plane].m.userptr = 0;
1448 vb->v4l2_planes[plane].length = 0;
1455 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1457 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1459 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1460 struct vb2_queue *q = vb->vb2_queue;
1464 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1465 bool reacquired = vb->planes[0].mem_priv == NULL;
1467 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1468 /* Copy relevant information provided by the userspace */
1469 __fill_vb2_buffer(vb, b, planes);
1471 for (plane = 0; plane < vb->num_planes; ++plane) {
1472 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1474 if (IS_ERR_OR_NULL(dbuf)) {
1475 dprintk(1, "invalid dmabuf fd for plane %d\n",
1481 /* use DMABUF size if length is not provided */
1482 if (planes[plane].length == 0)
1483 planes[plane].length = dbuf->size;
1485 if (planes[plane].length < q->plane_sizes[plane]) {
1486 dprintk(1, "invalid dmabuf length for plane %d\n",
1492 /* Skip the plane if already verified */
1493 if (dbuf == vb->planes[plane].dbuf &&
1494 vb->v4l2_planes[plane].length == planes[plane].length) {
1499 dprintk(1, "buffer for plane %d changed\n", plane);
1503 call_void_vb_qop(vb, buf_cleanup, vb);
1506 /* Release previously acquired memory if present */
1507 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1508 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1510 /* Acquire each plane's memory */
1511 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1512 dbuf, planes[plane].length, write);
1513 if (IS_ERR(mem_priv)) {
1514 dprintk(1, "failed to attach dmabuf\n");
1515 ret = PTR_ERR(mem_priv);
1520 vb->planes[plane].dbuf = dbuf;
1521 vb->planes[plane].mem_priv = mem_priv;
1524 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1525 * really we want to do this just before the DMA, not while queueing
1528 for (plane = 0; plane < vb->num_planes; ++plane) {
1529 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1531 dprintk(1, "failed to map dmabuf for plane %d\n",
1535 vb->planes[plane].dbuf_mapped = 1;
1539 * Now that everything is in order, copy relevant information
1540 * provided by userspace.
1542 for (plane = 0; plane < vb->num_planes; ++plane)
1543 vb->v4l2_planes[plane] = planes[plane];
1547 * Call driver-specific initialization on the newly acquired buffer,
1550 ret = call_vb_qop(vb, buf_init, vb);
1552 dprintk(1, "buffer initialization failed\n");
1557 ret = call_vb_qop(vb, buf_prepare, vb);
1559 dprintk(1, "buffer preparation failed\n");
1560 call_void_vb_qop(vb, buf_cleanup, vb);
1566 /* In case of errors, release planes that were already acquired */
1567 __vb2_buf_dmabuf_put(vb);
1573 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1575 static void __enqueue_in_driver(struct vb2_buffer *vb)
1577 struct vb2_queue *q = vb->vb2_queue;
1580 vb->state = VB2_BUF_STATE_ACTIVE;
1581 atomic_inc(&q->owned_by_drv_count);
1584 for (plane = 0; plane < vb->num_planes; ++plane)
1585 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1587 call_void_vb_qop(vb, buf_queue, vb);
1590 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1592 struct vb2_queue *q = vb->vb2_queue;
1595 ret = __verify_length(vb, b);
1597 dprintk(1, "plane parameters verification failed: %d\n", ret);
1600 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1602 * If the format's field is ALTERNATE, then the buffer's field
1603 * should be either TOP or BOTTOM, not ALTERNATE since that
1604 * makes no sense. The driver has to know whether the
1605 * buffer represents a top or a bottom field in order to
1606 * program any DMA correctly. Using ALTERNATE is wrong, since
1607 * that just says that it is either a top or a bottom field,
1608 * but not which of the two it is.
1610 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1615 dprintk(1, "fatal error occurred on queue\n");
1619 vb->state = VB2_BUF_STATE_PREPARING;
1620 vb->v4l2_buf.timestamp.tv_sec = 0;
1621 vb->v4l2_buf.timestamp.tv_usec = 0;
1622 vb->v4l2_buf.sequence = 0;
1624 switch (q->memory) {
1625 case V4L2_MEMORY_MMAP:
1626 ret = __qbuf_mmap(vb, b);
1628 case V4L2_MEMORY_USERPTR:
1629 down_read(¤t->mm->mmap_sem);
1630 ret = __qbuf_userptr(vb, b);
1631 up_read(¤t->mm->mmap_sem);
1633 case V4L2_MEMORY_DMABUF:
1634 ret = __qbuf_dmabuf(vb, b);
1637 WARN(1, "Invalid queue type\n");
1642 dprintk(1, "buffer preparation failed: %d\n", ret);
1643 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1648 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1651 if (b->type != q->type) {
1652 dprintk(1, "%s: invalid buffer type\n", opname);
1656 if (b->index >= q->num_buffers) {
1657 dprintk(1, "%s: buffer index out of range\n", opname);
1661 if (q->bufs[b->index] == NULL) {
1662 /* Should never happen */
1663 dprintk(1, "%s: buffer is NULL\n", opname);
1667 if (b->memory != q->memory) {
1668 dprintk(1, "%s: invalid memory type\n", opname);
1672 return __verify_planes_array(q->bufs[b->index], b);
1676 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1677 * @q: videobuf2 queue
1678 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1681 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1683 * 1) verifies the passed buffer,
1684 * 2) calls buf_prepare callback in the driver (if provided), in which
1685 * driver-specific buffer initialization can be performed,
1687 * The return values from this function are intended to be directly returned
1688 * from vidioc_prepare_buf handler in driver.
1690 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1692 struct vb2_buffer *vb;
1695 if (vb2_fileio_is_active(q)) {
1696 dprintk(1, "file io in progress\n");
1700 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1704 vb = q->bufs[b->index];
1705 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1706 dprintk(1, "invalid buffer state %d\n",
1711 ret = __buf_prepare(vb, b);
1713 /* Fill buffer information for the userspace */
1714 __fill_v4l2_buffer(vb, b);
1716 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1720 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1723 * vb2_start_streaming() - Attempt to start streaming.
1724 * @q: videobuf2 queue
1726 * Attempt to start streaming. When this function is called there must be
1727 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1728 * number of buffers required for the DMA engine to function). If the
1729 * @start_streaming op fails it is supposed to return all the driver-owned
1730 * buffers back to vb2 in state QUEUED. Check if that happened and if
1731 * not warn and reclaim them forcefully.
1733 static int vb2_start_streaming(struct vb2_queue *q)
1735 struct vb2_buffer *vb;
1739 * If any buffers were queued before streamon,
1740 * we can now pass them to driver for processing.
1742 list_for_each_entry(vb, &q->queued_list, queued_entry)
1743 __enqueue_in_driver(vb);
1745 /* Tell the driver to start streaming */
1746 q->start_streaming_called = 1;
1747 ret = call_qop(q, start_streaming, q,
1748 atomic_read(&q->owned_by_drv_count));
1752 q->start_streaming_called = 0;
1754 dprintk(1, "driver refused to start streaming\n");
1756 * If you see this warning, then the driver isn't cleaning up properly
1757 * after a failed start_streaming(). See the start_streaming()
1758 * documentation in videobuf2-core.h for more information how buffers
1759 * should be returned to vb2 in start_streaming().
1761 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1765 * Forcefully reclaim buffers if the driver did not
1766 * correctly return them to vb2.
1768 for (i = 0; i < q->num_buffers; ++i) {
1770 if (vb->state == VB2_BUF_STATE_ACTIVE)
1771 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1773 /* Must be zero now */
1774 WARN_ON(atomic_read(&q->owned_by_drv_count));
1777 * If done_list is not empty, then start_streaming() didn't call
1778 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1781 WARN_ON(!list_empty(&q->done_list));
1785 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1787 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1788 struct vb2_buffer *vb;
1793 vb = q->bufs[b->index];
1795 switch (vb->state) {
1796 case VB2_BUF_STATE_DEQUEUED:
1797 ret = __buf_prepare(vb, b);
1801 case VB2_BUF_STATE_PREPARED:
1803 case VB2_BUF_STATE_PREPARING:
1804 dprintk(1, "buffer still being prepared\n");
1807 dprintk(1, "invalid buffer state %d\n", vb->state);
1812 * Add to the queued buffers list, a buffer will stay on it until
1813 * dequeued in dqbuf.
1815 list_add_tail(&vb->queued_entry, &q->queued_list);
1817 q->waiting_for_buffers = false;
1818 vb->state = VB2_BUF_STATE_QUEUED;
1819 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1821 * For output buffers copy the timestamp if needed,
1822 * and the timecode field and flag if needed.
1824 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1825 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1826 vb->v4l2_buf.timestamp = b->timestamp;
1827 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1828 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1829 vb->v4l2_buf.timecode = b->timecode;
1833 * If already streaming, give the buffer to driver for processing.
1834 * If not, the buffer will be given to driver on next streamon.
1836 if (q->start_streaming_called)
1837 __enqueue_in_driver(vb);
1839 /* Fill buffer information for the userspace */
1840 __fill_v4l2_buffer(vb, b);
1843 * If streamon has been called, and we haven't yet called
1844 * start_streaming() since not enough buffers were queued, and
1845 * we now have reached the minimum number of queued buffers,
1846 * then we can finally call start_streaming().
1848 if (q->streaming && !q->start_streaming_called &&
1849 q->queued_count >= q->min_buffers_needed) {
1850 ret = vb2_start_streaming(q);
1855 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1860 * vb2_qbuf() - Queue a buffer from userspace
1861 * @q: videobuf2 queue
1862 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1865 * Should be called from vidioc_qbuf ioctl handler of a driver.
1867 * 1) verifies the passed buffer,
1868 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1869 * which driver-specific buffer initialization can be performed,
1870 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1871 * callback for processing.
1873 * The return values from this function are intended to be directly returned
1874 * from vidioc_qbuf handler in driver.
1876 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1878 if (vb2_fileio_is_active(q)) {
1879 dprintk(1, "file io in progress\n");
1883 return vb2_internal_qbuf(q, b);
1885 EXPORT_SYMBOL_GPL(vb2_qbuf);
1888 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1891 * Will sleep if required for nonblocking == false.
1893 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1896 * All operations on vb_done_list are performed under done_lock
1897 * spinlock protection. However, buffers may be removed from
1898 * it and returned to userspace only while holding both driver's
1899 * lock and the done_lock spinlock. Thus we can be sure that as
1900 * long as we hold the driver's lock, the list will remain not
1901 * empty if list_empty() check succeeds.
1907 if (!q->streaming) {
1908 dprintk(1, "streaming off, will not wait for buffers\n");
1913 dprintk(1, "Queue in error state, will not wait for buffers\n");
1917 if (!list_empty(&q->done_list)) {
1919 * Found a buffer that we were waiting for.
1925 dprintk(1, "nonblocking and no buffers to dequeue, "
1931 * We are streaming and blocking, wait for another buffer to
1932 * become ready or for streamoff. Driver's lock is released to
1933 * allow streamoff or qbuf to be called while waiting.
1935 call_void_qop(q, wait_prepare, q);
1938 * All locks have been released, it is safe to sleep now.
1940 dprintk(3, "will sleep waiting for buffers\n");
1941 ret = wait_event_interruptible(q->done_wq,
1942 !list_empty(&q->done_list) || !q->streaming ||
1946 * We need to reevaluate both conditions again after reacquiring
1947 * the locks or return an error if one occurred.
1949 call_void_qop(q, wait_finish, q);
1951 dprintk(1, "sleep was interrupted\n");
1959 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1961 * Will sleep if required for nonblocking == false.
1963 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1964 struct v4l2_buffer *b, int nonblocking)
1966 unsigned long flags;
1970 * Wait for at least one buffer to become available on the done_list.
1972 ret = __vb2_wait_for_done_vb(q, nonblocking);
1977 * Driver's lock has been held since we last verified that done_list
1978 * is not empty, so no need for another list_empty(done_list) check.
1980 spin_lock_irqsave(&q->done_lock, flags);
1981 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1983 * Only remove the buffer from done_list if v4l2_buffer can handle all
1986 ret = __verify_planes_array(*vb, b);
1988 list_del(&(*vb)->done_entry);
1989 spin_unlock_irqrestore(&q->done_lock, flags);
1995 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1996 * @q: videobuf2 queue
1998 * This function will wait until all buffers that have been given to the driver
1999 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2000 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2001 * taken, for example from stop_streaming() callback.
2003 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2005 if (!q->streaming) {
2006 dprintk(1, "streaming off, will not wait for buffers\n");
2010 if (q->start_streaming_called)
2011 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2014 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2017 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2019 static void __vb2_dqbuf(struct vb2_buffer *vb)
2021 struct vb2_queue *q = vb->vb2_queue;
2024 /* nothing to do if the buffer is already dequeued */
2025 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2028 vb->state = VB2_BUF_STATE_DEQUEUED;
2030 /* unmap DMABUF buffer */
2031 if (q->memory == V4L2_MEMORY_DMABUF)
2032 for (i = 0; i < vb->num_planes; ++i) {
2033 if (!vb->planes[i].dbuf_mapped)
2035 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2036 vb->planes[i].dbuf_mapped = 0;
2040 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2042 struct vb2_buffer *vb = NULL;
2045 if (b->type != q->type) {
2046 dprintk(1, "invalid buffer type\n");
2049 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2053 switch (vb->state) {
2054 case VB2_BUF_STATE_DONE:
2055 dprintk(3, "returning done buffer\n");
2057 case VB2_BUF_STATE_ERROR:
2058 dprintk(3, "returning done buffer with errors\n");
2061 dprintk(1, "invalid buffer state\n");
2065 call_void_vb_qop(vb, buf_finish, vb);
2067 /* Fill buffer information for the userspace */
2068 __fill_v4l2_buffer(vb, b);
2069 /* Remove from videobuf queue */
2070 list_del(&vb->queued_entry);
2072 /* go back to dequeued state */
2075 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2076 vb->v4l2_buf.index, vb->state);
2082 * vb2_dqbuf() - Dequeue a buffer to the userspace
2083 * @q: videobuf2 queue
2084 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2086 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2087 * buffers ready for dequeuing are present. Normally the driver
2088 * would be passing (file->f_flags & O_NONBLOCK) here
2090 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2092 * 1) verifies the passed buffer,
2093 * 2) calls buf_finish callback in the driver (if provided), in which
2094 * driver can perform any additional operations that may be required before
2095 * returning the buffer to userspace, such as cache sync,
2096 * 3) the buffer struct members are filled with relevant information for
2099 * The return values from this function are intended to be directly returned
2100 * from vidioc_dqbuf handler in driver.
2102 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2104 if (vb2_fileio_is_active(q)) {
2105 dprintk(1, "file io in progress\n");
2108 return vb2_internal_dqbuf(q, b, nonblocking);
2110 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2113 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2115 * Removes all queued buffers from driver's queue and all buffers queued by
2116 * userspace from videobuf's queue. Returns to state after reqbufs.
2118 static void __vb2_queue_cancel(struct vb2_queue *q)
2123 * Tell driver to stop all transactions and release all queued
2126 if (q->start_streaming_called)
2127 call_void_qop(q, stop_streaming, q);
2130 * If you see this warning, then the driver isn't cleaning up properly
2131 * in stop_streaming(). See the stop_streaming() documentation in
2132 * videobuf2-core.h for more information how buffers should be returned
2133 * to vb2 in stop_streaming().
2135 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2136 for (i = 0; i < q->num_buffers; ++i)
2137 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2138 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2139 /* Must be zero now */
2140 WARN_ON(atomic_read(&q->owned_by_drv_count));
2144 q->start_streaming_called = 0;
2145 q->queued_count = 0;
2149 * Remove all buffers from videobuf's list...
2151 INIT_LIST_HEAD(&q->queued_list);
2153 * ...and done list; userspace will not receive any buffers it
2154 * has not already dequeued before initiating cancel.
2156 INIT_LIST_HEAD(&q->done_list);
2157 atomic_set(&q->owned_by_drv_count, 0);
2158 wake_up_all(&q->done_wq);
2161 * Reinitialize all buffers for next use.
2162 * Make sure to call buf_finish for any queued buffers. Normally
2163 * that's done in dqbuf, but that's not going to happen when we
2164 * cancel the whole queue. Note: this code belongs here, not in
2165 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2166 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2167 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2169 for (i = 0; i < q->num_buffers; ++i) {
2170 struct vb2_buffer *vb = q->bufs[i];
2172 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2173 vb->state = VB2_BUF_STATE_PREPARED;
2174 call_void_vb_qop(vb, buf_finish, vb);
2180 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2184 if (type != q->type) {
2185 dprintk(1, "invalid stream type\n");
2190 dprintk(3, "already streaming\n");
2194 if (!q->num_buffers) {
2195 dprintk(1, "no buffers have been allocated\n");
2199 if (q->num_buffers < q->min_buffers_needed) {
2200 dprintk(1, "need at least %u allocated buffers\n",
2201 q->min_buffers_needed);
2206 * Tell driver to start streaming provided sufficient buffers
2209 if (q->queued_count >= q->min_buffers_needed) {
2210 ret = vb2_start_streaming(q);
2212 __vb2_queue_cancel(q);
2219 dprintk(3, "successful\n");
2224 * vb2_queue_error() - signal a fatal error on the queue
2225 * @q: videobuf2 queue
2227 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2228 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2229 * buffers will return -EIO.
2231 * The error flag will be cleared when cancelling the queue, either from
2232 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2233 * function before starting the stream, otherwise the error flag will remain set
2234 * until the queue is released when closing the device node.
2236 void vb2_queue_error(struct vb2_queue *q)
2240 wake_up_all(&q->done_wq);
2242 EXPORT_SYMBOL_GPL(vb2_queue_error);
2245 * vb2_streamon - start streaming
2246 * @q: videobuf2 queue
2247 * @type: type argument passed from userspace to vidioc_streamon handler
2249 * Should be called from vidioc_streamon handler of a driver.
2251 * 1) verifies current state
2252 * 2) passes any previously queued buffers to the driver and starts streaming
2254 * The return values from this function are intended to be directly returned
2255 * from vidioc_streamon handler in the driver.
2257 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2259 if (vb2_fileio_is_active(q)) {
2260 dprintk(1, "file io in progress\n");
2263 return vb2_internal_streamon(q, type);
2265 EXPORT_SYMBOL_GPL(vb2_streamon);
2267 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2269 if (type != q->type) {
2270 dprintk(1, "invalid stream type\n");
2275 * Cancel will pause streaming and remove all buffers from the driver
2276 * and videobuf, effectively returning control over them to userspace.
2278 * Note that we do this even if q->streaming == 0: if you prepare or
2279 * queue buffers, and then call streamoff without ever having called
2280 * streamon, you would still expect those buffers to be returned to
2281 * their normal dequeued state.
2283 __vb2_queue_cancel(q);
2284 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2286 dprintk(3, "successful\n");
2291 * vb2_streamoff - stop streaming
2292 * @q: videobuf2 queue
2293 * @type: type argument passed from userspace to vidioc_streamoff handler
2295 * Should be called from vidioc_streamoff handler of a driver.
2297 * 1) verifies current state,
2298 * 2) stop streaming and dequeues any queued buffers, including those previously
2299 * passed to the driver (after waiting for the driver to finish).
2301 * This call can be used for pausing playback.
2302 * The return values from this function are intended to be directly returned
2303 * from vidioc_streamoff handler in the driver
2305 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2307 if (vb2_fileio_is_active(q)) {
2308 dprintk(1, "file io in progress\n");
2311 return vb2_internal_streamoff(q, type);
2313 EXPORT_SYMBOL_GPL(vb2_streamoff);
2316 * __find_plane_by_offset() - find plane associated with the given offset off
2318 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2319 unsigned int *_buffer, unsigned int *_plane)
2321 struct vb2_buffer *vb;
2322 unsigned int buffer, plane;
2325 * Go over all buffers and their planes, comparing the given offset
2326 * with an offset assigned to each plane. If a match is found,
2327 * return its buffer and plane numbers.
2329 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2330 vb = q->bufs[buffer];
2332 for (plane = 0; plane < vb->num_planes; ++plane) {
2333 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2345 * vb2_expbuf() - Export a buffer as a file descriptor
2346 * @q: videobuf2 queue
2347 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2350 * The return values from this function are intended to be directly returned
2351 * from vidioc_expbuf handler in driver.
2353 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2355 struct vb2_buffer *vb = NULL;
2356 struct vb2_plane *vb_plane;
2358 struct dma_buf *dbuf;
2360 if (q->memory != V4L2_MEMORY_MMAP) {
2361 dprintk(1, "queue is not currently set up for mmap\n");
2365 if (!q->mem_ops->get_dmabuf) {
2366 dprintk(1, "queue does not support DMA buffer exporting\n");
2370 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2371 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2375 if (eb->type != q->type) {
2376 dprintk(1, "invalid buffer type\n");
2380 if (eb->index >= q->num_buffers) {
2381 dprintk(1, "buffer index out of range\n");
2385 vb = q->bufs[eb->index];
2387 if (eb->plane >= vb->num_planes) {
2388 dprintk(1, "buffer plane out of range\n");
2392 if (vb2_fileio_is_active(q)) {
2393 dprintk(1, "expbuf: file io in progress\n");
2397 vb_plane = &vb->planes[eb->plane];
2399 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2400 if (IS_ERR_OR_NULL(dbuf)) {
2401 dprintk(1, "failed to export buffer %d, plane %d\n",
2402 eb->index, eb->plane);
2406 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2408 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2409 eb->index, eb->plane, ret);
2414 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2415 eb->index, eb->plane, ret);
2420 EXPORT_SYMBOL_GPL(vb2_expbuf);
2423 * vb2_mmap() - map video buffers into application address space
2424 * @q: videobuf2 queue
2425 * @vma: vma passed to the mmap file operation handler in the driver
2427 * Should be called from mmap file operation handler of a driver.
2428 * This function maps one plane of one of the available video buffers to
2429 * userspace. To map whole video memory allocated on reqbufs, this function
2430 * has to be called once per each plane per each buffer previously allocated.
2432 * When the userspace application calls mmap, it passes to it an offset returned
2433 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2434 * a "cookie", which is then used to identify the plane to be mapped.
2435 * This function finds a plane with a matching offset and a mapping is performed
2436 * by the means of a provided memory operation.
2438 * The return values from this function are intended to be directly returned
2439 * from the mmap handler in driver.
2441 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2443 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2444 struct vb2_buffer *vb;
2445 unsigned int buffer = 0, plane = 0;
2447 unsigned long length;
2449 if (q->memory != V4L2_MEMORY_MMAP) {
2450 dprintk(1, "queue is not currently set up for mmap\n");
2455 * Check memory area access mode.
2457 if (!(vma->vm_flags & VM_SHARED)) {
2458 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2461 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2462 if (!(vma->vm_flags & VM_WRITE)) {
2463 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2467 if (!(vma->vm_flags & VM_READ)) {
2468 dprintk(1, "invalid vma flags, VM_READ needed\n");
2472 if (vb2_fileio_is_active(q)) {
2473 dprintk(1, "mmap: file io in progress\n");
2478 * Find the plane corresponding to the offset passed by userspace.
2480 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2484 vb = q->bufs[buffer];
2487 * MMAP requires page_aligned buffers.
2488 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2489 * so, we need to do the same here.
2491 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2492 if (length < (vma->vm_end - vma->vm_start)) {
2494 "MMAP invalid, as it would overflow buffer length\n");
2498 mutex_lock(&q->mmap_lock);
2499 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2500 mutex_unlock(&q->mmap_lock);
2504 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2507 EXPORT_SYMBOL_GPL(vb2_mmap);
2510 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2513 unsigned long pgoff,
2514 unsigned long flags)
2516 unsigned long off = pgoff << PAGE_SHIFT;
2517 struct vb2_buffer *vb;
2518 unsigned int buffer, plane;
2522 if (q->memory != V4L2_MEMORY_MMAP) {
2523 dprintk(1, "queue is not currently set up for mmap\n");
2528 * Find the plane corresponding to the offset passed by userspace.
2530 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2534 vb = q->bufs[buffer];
2536 vaddr = vb2_plane_vaddr(vb, plane);
2537 return vaddr ? (unsigned long)vaddr : -EINVAL;
2539 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2542 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2543 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2546 * vb2_poll() - implements poll userspace operation
2547 * @q: videobuf2 queue
2548 * @file: file argument passed to the poll file operation handler
2549 * @wait: wait argument passed to the poll file operation handler
2551 * This function implements poll file operation handler for a driver.
2552 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2553 * be informed that the file descriptor of a video device is available for
2555 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2556 * will be reported as available for writing.
2558 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2561 * The return values from this function are intended to be directly returned
2562 * from poll handler in driver.
2564 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2566 struct video_device *vfd = video_devdata(file);
2567 unsigned long req_events = poll_requested_events(wait);
2568 struct vb2_buffer *vb = NULL;
2569 unsigned int res = 0;
2570 unsigned long flags;
2572 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2573 struct v4l2_fh *fh = file->private_data;
2575 if (v4l2_event_pending(fh))
2577 else if (req_events & POLLPRI)
2578 poll_wait(file, &fh->wait, wait);
2581 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2583 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2587 * Start file I/O emulator only if streaming API has not been used yet.
2589 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2590 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2591 (req_events & (POLLIN | POLLRDNORM))) {
2592 if (__vb2_init_fileio(q, 1))
2593 return res | POLLERR;
2595 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2596 (req_events & (POLLOUT | POLLWRNORM))) {
2597 if (__vb2_init_fileio(q, 0))
2598 return res | POLLERR;
2600 * Write to OUTPUT queue can be done immediately.
2602 return res | POLLOUT | POLLWRNORM;
2607 * There is nothing to wait for if the queue isn't streaming, or if the
2608 * error flag is set.
2610 if (!vb2_is_streaming(q) || q->error)
2611 return res | POLLERR;
2613 * For compatibility with vb1: if QBUF hasn't been called yet, then
2614 * return POLLERR as well. This only affects capture queues, output
2615 * queues will always initialize waiting_for_buffers to false.
2617 if (q->waiting_for_buffers)
2618 return res | POLLERR;
2621 * For output streams you can write as long as there are fewer buffers
2622 * queued than there are buffers available.
2624 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2625 return res | POLLOUT | POLLWRNORM;
2627 if (list_empty(&q->done_list))
2628 poll_wait(file, &q->done_wq, wait);
2631 * Take first buffer available for dequeuing.
2633 spin_lock_irqsave(&q->done_lock, flags);
2634 if (!list_empty(&q->done_list))
2635 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2637 spin_unlock_irqrestore(&q->done_lock, flags);
2639 if (vb && (vb->state == VB2_BUF_STATE_DONE
2640 || vb->state == VB2_BUF_STATE_ERROR)) {
2641 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2642 res | POLLOUT | POLLWRNORM :
2643 res | POLLIN | POLLRDNORM;
2647 EXPORT_SYMBOL_GPL(vb2_poll);
2650 * vb2_queue_init() - initialize a videobuf2 queue
2651 * @q: videobuf2 queue; this structure should be allocated in driver
2653 * The vb2_queue structure should be allocated by the driver. The driver is
2654 * responsible of clearing it's content and setting initial values for some
2655 * required entries before calling this function.
2656 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2657 * to the struct vb2_queue description in include/media/videobuf2-core.h
2658 * for more information.
2660 int vb2_queue_init(struct vb2_queue *q)
2667 WARN_ON(!q->mem_ops) ||
2668 WARN_ON(!q->type) ||
2669 WARN_ON(!q->io_modes) ||
2670 WARN_ON(!q->ops->queue_setup) ||
2671 WARN_ON(!q->ops->buf_queue) ||
2672 WARN_ON(q->timestamp_flags &
2673 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2674 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2677 /* Warn that the driver should choose an appropriate timestamp type */
2678 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2679 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2681 INIT_LIST_HEAD(&q->queued_list);
2682 INIT_LIST_HEAD(&q->done_list);
2683 spin_lock_init(&q->done_lock);
2684 mutex_init(&q->mmap_lock);
2685 init_waitqueue_head(&q->done_wq);
2687 if (q->buf_struct_size == 0)
2688 q->buf_struct_size = sizeof(struct vb2_buffer);
2692 EXPORT_SYMBOL_GPL(vb2_queue_init);
2695 * vb2_queue_release() - stop streaming, release the queue and free memory
2696 * @q: videobuf2 queue
2698 * This function stops streaming and performs necessary clean ups, including
2699 * freeing video buffer memory. The driver is responsible for freeing
2700 * the vb2_queue structure itself.
2702 void vb2_queue_release(struct vb2_queue *q)
2704 __vb2_cleanup_fileio(q);
2705 __vb2_queue_cancel(q);
2706 mutex_lock(&q->mmap_lock);
2707 __vb2_queue_free(q, q->num_buffers);
2708 mutex_unlock(&q->mmap_lock);
2710 EXPORT_SYMBOL_GPL(vb2_queue_release);
2713 * struct vb2_fileio_buf - buffer context used by file io emulator
2715 * vb2 provides a compatibility layer and emulator of file io (read and
2716 * write) calls on top of streaming API. This structure is used for
2717 * tracking context related to the buffers.
2719 struct vb2_fileio_buf {
2723 unsigned int queued:1;
2727 * struct vb2_fileio_data - queue context used by file io emulator
2729 * @cur_index: the index of the buffer currently being read from or
2730 * written to. If equal to q->num_buffers then a new buffer
2732 * @initial_index: in the read() case all buffers are queued up immediately
2733 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2734 * buffers. However, in the write() case no buffers are initially
2735 * queued, instead whenever a buffer is full it is queued up by
2736 * __vb2_perform_fileio(). Only once all available buffers have
2737 * been queued up will __vb2_perform_fileio() start to dequeue
2738 * buffers. This means that initially __vb2_perform_fileio()
2739 * needs to know what buffer index to use when it is queuing up
2740 * the buffers for the first time. That initial index is stored
2741 * in this field. Once it is equal to q->num_buffers all
2742 * available buffers have been queued and __vb2_perform_fileio()
2743 * should start the normal dequeue/queue cycle.
2745 * vb2 provides a compatibility layer and emulator of file io (read and
2746 * write) calls on top of streaming API. For proper operation it required
2747 * this structure to save the driver state between each call of the read
2748 * or write function.
2750 struct vb2_fileio_data {
2751 struct v4l2_requestbuffers req;
2752 struct v4l2_plane p;
2753 struct v4l2_buffer b;
2754 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2755 unsigned int cur_index;
2756 unsigned int initial_index;
2757 unsigned int q_count;
2758 unsigned int dq_count;
2763 * __vb2_init_fileio() - initialize file io emulator
2764 * @q: videobuf2 queue
2765 * @read: mode selector (1 means read, 0 means write)
2767 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2769 struct vb2_fileio_data *fileio;
2771 unsigned int count = 0;
2776 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2777 (!read && !(q->io_modes & VB2_WRITE))))
2781 * Check if device supports mapping buffers to kernel virtual space.
2783 if (!q->mem_ops->vaddr)
2787 * Check if streaming api has not been already activated.
2789 if (q->streaming || q->num_buffers > 0)
2793 * Start with count 1, driver can increase it in queue_setup()
2797 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2798 (read) ? "read" : "write", count, q->io_flags);
2800 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2804 fileio->flags = q->io_flags;
2807 * Request buffers and use MMAP type to force driver
2808 * to allocate buffers by itself.
2810 fileio->req.count = count;
2811 fileio->req.memory = V4L2_MEMORY_MMAP;
2812 fileio->req.type = q->type;
2814 ret = __reqbufs(q, &fileio->req);
2819 * Check if plane_count is correct
2820 * (multiplane buffers are not supported).
2822 if (q->bufs[0]->num_planes != 1) {
2828 * Get kernel address of each buffer.
2830 for (i = 0; i < q->num_buffers; i++) {
2831 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2832 if (fileio->bufs[i].vaddr == NULL) {
2836 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2840 * Read mode requires pre queuing of all buffers.
2843 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2846 * Queue all buffers.
2848 for (i = 0; i < q->num_buffers; i++) {
2849 struct v4l2_buffer *b = &fileio->b;
2851 memset(b, 0, sizeof(*b));
2853 if (is_multiplanar) {
2854 memset(&fileio->p, 0, sizeof(fileio->p));
2855 b->m.planes = &fileio->p;
2858 b->memory = q->memory;
2860 ret = vb2_internal_qbuf(q, b);
2863 fileio->bufs[i].queued = 1;
2866 * All buffers have been queued, so mark that by setting
2867 * initial_index to q->num_buffers
2869 fileio->initial_index = q->num_buffers;
2870 fileio->cur_index = q->num_buffers;
2876 ret = vb2_internal_streamon(q, q->type);
2883 fileio->req.count = 0;
2884 __reqbufs(q, &fileio->req);
2893 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2894 * @q: videobuf2 queue
2896 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2898 struct vb2_fileio_data *fileio = q->fileio;
2901 vb2_internal_streamoff(q, q->type);
2903 fileio->req.count = 0;
2904 vb2_reqbufs(q, &fileio->req);
2906 dprintk(3, "file io emulator closed\n");
2912 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2913 * @q: videobuf2 queue
2914 * @data: pointed to target userspace buffer
2915 * @count: number of bytes to read or write
2916 * @ppos: file handle position tracking pointer
2917 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2918 * @read: access mode selector (1 means read, 0 means write)
2920 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2921 loff_t *ppos, int nonblock, int read)
2923 struct vb2_fileio_data *fileio;
2924 struct vb2_fileio_buf *buf;
2925 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2927 * When using write() to write data to an output video node the vb2 core
2928 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2929 * else is able to provide this information with the write() operation.
2931 bool set_timestamp = !read &&
2932 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2933 V4L2_BUF_FLAG_TIMESTAMP_COPY;
2936 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2937 read ? "read" : "write", (long)*ppos, count,
2938 nonblock ? "non" : "");
2944 * Initialize emulator on first call.
2946 if (!vb2_fileio_is_active(q)) {
2947 ret = __vb2_init_fileio(q, read);
2948 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2955 * Check if we need to dequeue the buffer.
2957 index = fileio->cur_index;
2958 if (index >= q->num_buffers) {
2960 * Call vb2_dqbuf to get buffer back.
2962 memset(&fileio->b, 0, sizeof(fileio->b));
2963 fileio->b.type = q->type;
2964 fileio->b.memory = q->memory;
2965 if (is_multiplanar) {
2966 memset(&fileio->p, 0, sizeof(fileio->p));
2967 fileio->b.m.planes = &fileio->p;
2968 fileio->b.length = 1;
2970 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
2971 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2974 fileio->dq_count += 1;
2976 fileio->cur_index = index = fileio->b.index;
2977 buf = &fileio->bufs[index];
2980 * Get number of bytes filled by the driver
2984 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2985 : vb2_plane_size(q->bufs[index], 0);
2986 /* Compensate for data_offset on read in the multiplanar case. */
2987 if (is_multiplanar && read &&
2988 fileio->b.m.planes[0].data_offset < buf->size) {
2989 buf->pos = fileio->b.m.planes[0].data_offset;
2990 buf->size -= buf->pos;
2993 buf = &fileio->bufs[index];
2997 * Limit count on last few bytes of the buffer.
2999 if (buf->pos + count > buf->size) {
3000 count = buf->size - buf->pos;
3001 dprintk(5, "reducing read count: %zd\n", count);
3005 * Transfer data to userspace.
3007 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3008 count, index, buf->pos);
3010 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3012 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3014 dprintk(3, "error copying data\n");
3025 * Queue next buffer if required.
3027 if (buf->pos == buf->size ||
3028 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
3030 * Check if this is the last buffer to read.
3032 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
3033 fileio->dq_count == 1) {
3034 dprintk(3, "read limit reached\n");
3035 return __vb2_cleanup_fileio(q);
3039 * Call vb2_qbuf and give buffer to the driver.
3041 memset(&fileio->b, 0, sizeof(fileio->b));
3042 fileio->b.type = q->type;
3043 fileio->b.memory = q->memory;
3044 fileio->b.index = index;
3045 fileio->b.bytesused = buf->pos;
3046 if (is_multiplanar) {
3047 memset(&fileio->p, 0, sizeof(fileio->p));
3048 fileio->p.bytesused = buf->pos;
3049 fileio->b.m.planes = &fileio->p;
3050 fileio->b.length = 1;
3053 v4l2_get_timestamp(&fileio->b.timestamp);
3054 ret = vb2_internal_qbuf(q, &fileio->b);
3055 dprintk(5, "vb2_dbuf result: %d\n", ret);
3060 * Buffer has been queued, update the status
3064 buf->size = vb2_plane_size(q->bufs[index], 0);
3065 fileio->q_count += 1;
3067 * If we are queuing up buffers for the first time, then
3068 * increase initial_index by one.
3070 if (fileio->initial_index < q->num_buffers)
3071 fileio->initial_index++;
3073 * The next buffer to use is either a buffer that's going to be
3074 * queued for the first time (initial_index < q->num_buffers)
3075 * or it is equal to q->num_buffers, meaning that the next
3076 * time we need to dequeue a buffer since we've now queued up
3077 * all the 'first time' buffers.
3079 fileio->cur_index = fileio->initial_index;
3083 * Return proper number of bytes processed.
3090 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3091 loff_t *ppos, int nonblocking)
3093 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3095 EXPORT_SYMBOL_GPL(vb2_read);
3097 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3098 loff_t *ppos, int nonblocking)
3100 return __vb2_perform_fileio(q, (char __user *) data, count,
3101 ppos, nonblocking, 0);
3103 EXPORT_SYMBOL_GPL(vb2_write);
3105 struct vb2_threadio_data {
3106 struct task_struct *thread;
3112 static int vb2_thread(void *data)
3114 struct vb2_queue *q = data;
3115 struct vb2_threadio_data *threadio = q->threadio;
3116 struct vb2_fileio_data *fileio = q->fileio;
3117 bool set_timestamp = false;
3122 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3123 prequeue = q->num_buffers;
3125 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3126 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3132 struct vb2_buffer *vb;
3135 * Call vb2_dqbuf to get buffer back.
3137 memset(&fileio->b, 0, sizeof(fileio->b));
3138 fileio->b.type = q->type;
3139 fileio->b.memory = q->memory;
3141 fileio->b.index = index++;
3144 call_void_qop(q, wait_finish, q);
3145 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3146 call_void_qop(q, wait_prepare, q);
3147 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3155 vb = q->bufs[fileio->b.index];
3156 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3157 ret = threadio->fnc(vb, threadio->priv);
3160 call_void_qop(q, wait_finish, q);
3162 v4l2_get_timestamp(&fileio->b.timestamp);
3163 ret = vb2_internal_qbuf(q, &fileio->b);
3164 call_void_qop(q, wait_prepare, q);
3169 /* Hmm, linux becomes *very* unhappy without this ... */
3170 while (!kthread_should_stop()) {
3171 set_current_state(TASK_INTERRUPTIBLE);
3178 * This function should not be used for anything else but the videobuf2-dvb
3179 * support. If you think you have another good use-case for this, then please
3180 * contact the linux-media mailinglist first.
3182 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3183 const char *thread_name)
3185 struct vb2_threadio_data *threadio;
3192 if (WARN_ON(q->fileio))
3195 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3196 if (threadio == NULL)
3198 threadio->fnc = fnc;
3199 threadio->priv = priv;
3201 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3202 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3205 q->threadio = threadio;
3206 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3207 if (IS_ERR(threadio->thread)) {
3208 ret = PTR_ERR(threadio->thread);
3209 threadio->thread = NULL;
3215 __vb2_cleanup_fileio(q);
3220 EXPORT_SYMBOL_GPL(vb2_thread_start);
3222 int vb2_thread_stop(struct vb2_queue *q)
3224 struct vb2_threadio_data *threadio = q->threadio;
3225 struct vb2_fileio_data *fileio = q->fileio;
3228 if (threadio == NULL)
3230 call_void_qop(q, wait_finish, q);
3231 threadio->stop = true;
3232 vb2_internal_streamoff(q, q->type);
3233 call_void_qop(q, wait_prepare, q);
3235 fileio->req.count = 0;
3236 vb2_reqbufs(q, &fileio->req);
3238 err = kthread_stop(threadio->thread);
3239 threadio->thread = NULL;
3245 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3248 * The following functions are not part of the vb2 core API, but are helper
3249 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3250 * and struct vb2_ops.
3251 * They contain boilerplate code that most if not all drivers have to do
3252 * and so they simplify the driver code.
3255 /* The queue is busy if there is a owner and you are not that owner. */
3256 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3258 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3261 /* vb2 ioctl helpers */
3263 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3264 struct v4l2_requestbuffers *p)
3266 struct video_device *vdev = video_devdata(file);
3267 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3271 if (vb2_queue_is_busy(vdev, file))
3273 res = __reqbufs(vdev->queue, p);
3274 /* If count == 0, then the owner has released all buffers and he
3275 is no longer owner of the queue. Otherwise we have a new owner. */
3277 vdev->queue->owner = p->count ? file->private_data : NULL;
3280 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3282 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3283 struct v4l2_create_buffers *p)
3285 struct video_device *vdev = video_devdata(file);
3286 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3288 p->index = vdev->queue->num_buffers;
3289 /* If count == 0, then just check if memory and type are valid.
3290 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3292 return res != -EBUSY ? res : 0;
3295 if (vb2_queue_is_busy(vdev, file))
3297 res = __create_bufs(vdev->queue, p);
3299 vdev->queue->owner = file->private_data;
3302 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3304 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3305 struct v4l2_buffer *p)
3307 struct video_device *vdev = video_devdata(file);
3309 if (vb2_queue_is_busy(vdev, file))
3311 return vb2_prepare_buf(vdev->queue, p);
3313 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3315 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3317 struct video_device *vdev = video_devdata(file);
3319 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3320 return vb2_querybuf(vdev->queue, p);
3322 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3324 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3326 struct video_device *vdev = video_devdata(file);
3328 if (vb2_queue_is_busy(vdev, file))
3330 return vb2_qbuf(vdev->queue, p);
3332 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3334 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3336 struct video_device *vdev = video_devdata(file);
3338 if (vb2_queue_is_busy(vdev, file))
3340 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3342 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3344 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3346 struct video_device *vdev = video_devdata(file);
3348 if (vb2_queue_is_busy(vdev, file))
3350 return vb2_streamon(vdev->queue, i);
3352 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3354 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3356 struct video_device *vdev = video_devdata(file);
3358 if (vb2_queue_is_busy(vdev, file))
3360 return vb2_streamoff(vdev->queue, i);
3362 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3364 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3366 struct video_device *vdev = video_devdata(file);
3368 if (vb2_queue_is_busy(vdev, file))
3370 return vb2_expbuf(vdev->queue, p);
3372 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3374 /* v4l2_file_operations helpers */
3376 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3378 struct video_device *vdev = video_devdata(file);
3380 return vb2_mmap(vdev->queue, vma);
3382 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3384 int _vb2_fop_release(struct file *file, struct mutex *lock)
3386 struct video_device *vdev = video_devdata(file);
3388 if (file->private_data == vdev->queue->owner) {
3391 vb2_queue_release(vdev->queue);
3392 vdev->queue->owner = NULL;
3396 return v4l2_fh_release(file);
3398 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3400 int vb2_fop_release(struct file *file)
3402 struct video_device *vdev = video_devdata(file);
3403 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3405 return _vb2_fop_release(file, lock);
3407 EXPORT_SYMBOL_GPL(vb2_fop_release);
3409 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3410 size_t count, loff_t *ppos)
3412 struct video_device *vdev = video_devdata(file);
3413 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3416 if (lock && mutex_lock_interruptible(lock))
3417 return -ERESTARTSYS;
3418 if (vb2_queue_is_busy(vdev, file))
3420 err = vb2_write(vdev->queue, buf, count, ppos,
3421 file->f_flags & O_NONBLOCK);
3422 if (vdev->queue->fileio)
3423 vdev->queue->owner = file->private_data;
3429 EXPORT_SYMBOL_GPL(vb2_fop_write);
3431 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3432 size_t count, loff_t *ppos)
3434 struct video_device *vdev = video_devdata(file);
3435 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3438 if (lock && mutex_lock_interruptible(lock))
3439 return -ERESTARTSYS;
3440 if (vb2_queue_is_busy(vdev, file))
3442 err = vb2_read(vdev->queue, buf, count, ppos,
3443 file->f_flags & O_NONBLOCK);
3444 if (vdev->queue->fileio)
3445 vdev->queue->owner = file->private_data;
3451 EXPORT_SYMBOL_GPL(vb2_fop_read);
3453 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3455 struct video_device *vdev = video_devdata(file);
3456 struct vb2_queue *q = vdev->queue;
3457 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3458 unsigned long req_events = poll_requested_events(wait);
3461 bool must_lock = false;
3463 /* Try to be smart: only lock if polling might start fileio,
3464 otherwise locking will only introduce unwanted delays. */
3465 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
3466 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
3467 (req_events & (POLLIN | POLLRDNORM)))
3469 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
3470 (req_events & (POLLOUT | POLLWRNORM)))
3474 /* If locking is needed, but this helper doesn't know how, then you
3475 shouldn't be using this helper but you should write your own. */
3476 WARN_ON(must_lock && !lock);
3478 if (must_lock && lock && mutex_lock_interruptible(lock))
3483 res = vb2_poll(vdev->queue, file, wait);
3485 /* If fileio was started, then we have a new queue owner. */
3486 if (must_lock && !fileio && q->fileio)
3487 q->owner = file->private_data;
3488 if (must_lock && lock)
3492 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3495 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3496 unsigned long len, unsigned long pgoff, unsigned long flags)
3498 struct video_device *vdev = video_devdata(file);
3500 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3502 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3505 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3507 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3509 mutex_unlock(vq->lock);
3511 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3513 void vb2_ops_wait_finish(struct vb2_queue *vq)
3515 mutex_lock(vq->lock);
3517 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3519 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3520 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3521 MODULE_LICENSE("GPL");