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 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation.
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
22 #include <media/v4l2-dev.h>
23 #include <media/v4l2-fh.h>
24 #include <media/v4l2-event.h>
25 #include <media/videobuf2-core.h>
28 module_param(debug, int, 0644);
30 #define dprintk(level, fmt, arg...) \
33 printk(KERN_DEBUG "vb2: " fmt, ## arg); \
36 #define call_memop(q, op, args...) \
37 (((q)->mem_ops->op) ? \
38 ((q)->mem_ops->op(args)) : 0)
40 #define call_qop(q, op, args...) \
41 (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
43 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
44 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
45 V4L2_BUF_FLAG_PREPARED | \
46 V4L2_BUF_FLAG_TIMESTAMP_MASK)
49 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
51 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
53 struct vb2_queue *q = vb->vb2_queue;
58 * Allocate memory for all planes in this buffer
59 * NOTE: mmapped areas should be page aligned
61 for (plane = 0; plane < vb->num_planes; ++plane) {
62 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
64 mem_priv = call_memop(q, alloc, q->alloc_ctx[plane],
66 if (IS_ERR_OR_NULL(mem_priv))
69 /* Associate allocator private data with this plane */
70 vb->planes[plane].mem_priv = mem_priv;
71 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
76 /* Free already allocated memory if one of the allocations failed */
77 for (; plane > 0; --plane) {
78 call_memop(q, put, vb->planes[plane - 1].mem_priv);
79 vb->planes[plane - 1].mem_priv = NULL;
86 * __vb2_buf_mem_free() - free memory of the given buffer
88 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
90 struct vb2_queue *q = vb->vb2_queue;
93 for (plane = 0; plane < vb->num_planes; ++plane) {
94 call_memop(q, put, vb->planes[plane].mem_priv);
95 vb->planes[plane].mem_priv = NULL;
96 dprintk(3, "Freed plane %d of buffer %d\n", plane,
102 * __vb2_buf_userptr_put() - release userspace memory associated with
105 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
107 struct vb2_queue *q = vb->vb2_queue;
110 for (plane = 0; plane < vb->num_planes; ++plane) {
111 if (vb->planes[plane].mem_priv)
112 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
113 vb->planes[plane].mem_priv = NULL;
118 * __vb2_plane_dmabuf_put() - release memory associated with
119 * a DMABUF shared plane
121 static void __vb2_plane_dmabuf_put(struct vb2_queue *q, struct vb2_plane *p)
127 call_memop(q, unmap_dmabuf, p->mem_priv);
129 call_memop(q, detach_dmabuf, p->mem_priv);
130 dma_buf_put(p->dbuf);
131 memset(p, 0, sizeof(*p));
135 * __vb2_buf_dmabuf_put() - release memory associated with
136 * a DMABUF shared buffer
138 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
140 struct vb2_queue *q = vb->vb2_queue;
143 for (plane = 0; plane < vb->num_planes; ++plane)
144 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
148 * __setup_lengths() - setup initial lengths for every plane in
149 * every buffer on the queue
151 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
153 unsigned int buffer, plane;
154 struct vb2_buffer *vb;
156 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
157 vb = q->bufs[buffer];
161 for (plane = 0; plane < vb->num_planes; ++plane)
162 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
167 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
168 * every buffer on the queue
170 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
172 unsigned int buffer, plane;
173 struct vb2_buffer *vb;
176 if (q->num_buffers) {
177 struct v4l2_plane *p;
178 vb = q->bufs[q->num_buffers - 1];
179 p = &vb->v4l2_planes[vb->num_planes - 1];
180 off = PAGE_ALIGN(p->m.mem_offset + p->length);
185 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
186 vb = q->bufs[buffer];
190 for (plane = 0; plane < vb->num_planes; ++plane) {
191 vb->v4l2_planes[plane].m.mem_offset = off;
193 dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
196 off += vb->v4l2_planes[plane].length;
197 off = PAGE_ALIGN(off);
203 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
204 * video buffer memory for all buffers/planes on the queue and initializes the
207 * Returns the number of buffers successfully allocated.
209 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
210 unsigned int num_buffers, unsigned int num_planes)
213 struct vb2_buffer *vb;
216 for (buffer = 0; buffer < num_buffers; ++buffer) {
217 /* Allocate videobuf buffer structures */
218 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
220 dprintk(1, "Memory alloc for buffer struct failed\n");
224 /* Length stores number of planes for multiplanar buffers */
225 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
226 vb->v4l2_buf.length = num_planes;
228 vb->state = VB2_BUF_STATE_DEQUEUED;
230 vb->num_planes = num_planes;
231 vb->v4l2_buf.index = q->num_buffers + buffer;
232 vb->v4l2_buf.type = q->type;
233 vb->v4l2_buf.memory = memory;
235 /* Allocate video buffer memory for the MMAP type */
236 if (memory == V4L2_MEMORY_MMAP) {
237 ret = __vb2_buf_mem_alloc(vb);
239 dprintk(1, "Failed allocating memory for "
240 "buffer %d\n", buffer);
245 * Call the driver-provided buffer initialization
246 * callback, if given. An error in initialization
247 * results in queue setup failure.
249 ret = call_qop(q, buf_init, vb);
251 dprintk(1, "Buffer %d %p initialization"
252 " failed\n", buffer, vb);
253 __vb2_buf_mem_free(vb);
259 q->bufs[q->num_buffers + buffer] = vb;
262 __setup_lengths(q, buffer);
263 if (memory == V4L2_MEMORY_MMAP)
264 __setup_offsets(q, buffer);
266 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
273 * __vb2_free_mem() - release all video buffer memory for a given queue
275 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
278 struct vb2_buffer *vb;
280 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
282 vb = q->bufs[buffer];
286 /* Free MMAP buffers or release USERPTR buffers */
287 if (q->memory == V4L2_MEMORY_MMAP)
288 __vb2_buf_mem_free(vb);
289 else if (q->memory == V4L2_MEMORY_DMABUF)
290 __vb2_buf_dmabuf_put(vb);
292 __vb2_buf_userptr_put(vb);
297 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
298 * related information, if no buffers are left return the queue to an
299 * uninitialized state. Might be called even if the queue has already been freed.
301 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
306 * Sanity check: when preparing a buffer the queue lock is released for
307 * a short while (see __buf_prepare for the details), which would allow
308 * a race with a reqbufs which can call this function. Removing the
309 * buffers from underneath __buf_prepare is obviously a bad idea, so we
310 * check if any of the buffers is in the state PREPARING, and if so we
311 * just return -EAGAIN.
313 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
315 if (q->bufs[buffer] == NULL)
317 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
318 dprintk(1, "reqbufs: preparing buffers, cannot free\n");
323 /* Call driver-provided cleanup function for each buffer, if provided */
324 if (q->ops->buf_cleanup) {
325 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
327 if (NULL == q->bufs[buffer])
329 q->ops->buf_cleanup(q->bufs[buffer]);
333 /* Release video buffer memory */
334 __vb2_free_mem(q, buffers);
336 /* Free videobuf buffers */
337 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
339 kfree(q->bufs[buffer]);
340 q->bufs[buffer] = NULL;
343 q->num_buffers -= buffers;
346 INIT_LIST_HEAD(&q->queued_list);
351 * __verify_planes_array() - verify that the planes array passed in struct
352 * v4l2_buffer from userspace can be safely used
354 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
356 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
359 /* Is memory for copying plane information present? */
360 if (NULL == b->m.planes) {
361 dprintk(1, "Multi-planar buffer passed but "
362 "planes array not provided\n");
366 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
367 dprintk(1, "Incorrect planes array length, "
368 "expected %d, got %d\n", vb->num_planes, b->length);
376 * __verify_length() - Verify that the bytesused value for each plane fits in
377 * the plane length and that the data offset doesn't exceed the bytesused value.
379 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
384 if (!V4L2_TYPE_IS_OUTPUT(b->type))
387 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
388 for (plane = 0; plane < vb->num_planes; ++plane) {
389 length = (b->memory == V4L2_MEMORY_USERPTR)
390 ? b->m.planes[plane].length
391 : vb->v4l2_planes[plane].length;
393 if (b->m.planes[plane].bytesused > length)
396 if (b->m.planes[plane].data_offset > 0 &&
397 b->m.planes[plane].data_offset >=
398 b->m.planes[plane].bytesused)
402 length = (b->memory == V4L2_MEMORY_USERPTR)
403 ? b->length : vb->v4l2_planes[0].length;
405 if (b->bytesused > length)
413 * __buffer_in_use() - return true if the buffer is in use and
414 * the queue cannot be freed (by the means of REQBUFS(0)) call
416 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
419 for (plane = 0; plane < vb->num_planes; ++plane) {
420 void *mem_priv = vb->planes[plane].mem_priv;
422 * If num_users() has not been provided, call_memop
423 * will return 0, apparently nobody cares about this
424 * case anyway. If num_users() returns more than 1,
425 * we are not the only user of the plane's memory.
427 if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
434 * __buffers_in_use() - return true if any buffers on the queue are in use and
435 * the queue cannot be freed (by the means of REQBUFS(0)) call
437 static bool __buffers_in_use(struct vb2_queue *q)
440 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
441 if (__buffer_in_use(q, q->bufs[buffer]))
448 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
449 * returned to userspace
451 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
453 struct vb2_queue *q = vb->vb2_queue;
455 /* Copy back data such as timestamp, flags, etc. */
456 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
457 b->reserved2 = vb->v4l2_buf.reserved2;
458 b->reserved = vb->v4l2_buf.reserved;
460 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
462 * Fill in plane-related data if userspace provided an array
463 * for it. The caller has already verified memory and size.
465 b->length = vb->num_planes;
466 memcpy(b->m.planes, vb->v4l2_planes,
467 b->length * sizeof(struct v4l2_plane));
470 * We use length and offset in v4l2_planes array even for
471 * single-planar buffers, but userspace does not.
473 b->length = vb->v4l2_planes[0].length;
474 b->bytesused = vb->v4l2_planes[0].bytesused;
475 if (q->memory == V4L2_MEMORY_MMAP)
476 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
477 else if (q->memory == V4L2_MEMORY_USERPTR)
478 b->m.userptr = vb->v4l2_planes[0].m.userptr;
479 else if (q->memory == V4L2_MEMORY_DMABUF)
480 b->m.fd = vb->v4l2_planes[0].m.fd;
484 * Clear any buffer state related flags.
486 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
487 b->flags |= q->timestamp_type;
490 case VB2_BUF_STATE_QUEUED:
491 case VB2_BUF_STATE_ACTIVE:
492 b->flags |= V4L2_BUF_FLAG_QUEUED;
494 case VB2_BUF_STATE_ERROR:
495 b->flags |= V4L2_BUF_FLAG_ERROR;
497 case VB2_BUF_STATE_DONE:
498 b->flags |= V4L2_BUF_FLAG_DONE;
500 case VB2_BUF_STATE_PREPARED:
501 b->flags |= V4L2_BUF_FLAG_PREPARED;
503 case VB2_BUF_STATE_PREPARING:
504 case VB2_BUF_STATE_DEQUEUED:
509 if (__buffer_in_use(q, vb))
510 b->flags |= V4L2_BUF_FLAG_MAPPED;
514 * vb2_querybuf() - query video buffer information
516 * @b: buffer struct passed from userspace to vidioc_querybuf handler
519 * Should be called from vidioc_querybuf ioctl handler in driver.
520 * This function will verify the passed v4l2_buffer structure and fill the
521 * relevant information for the userspace.
523 * The return values from this function are intended to be directly returned
524 * from vidioc_querybuf handler in driver.
526 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
528 struct vb2_buffer *vb;
531 if (b->type != q->type) {
532 dprintk(1, "querybuf: wrong buffer type\n");
536 if (b->index >= q->num_buffers) {
537 dprintk(1, "querybuf: buffer index out of range\n");
540 vb = q->bufs[b->index];
541 ret = __verify_planes_array(vb, b);
543 __fill_v4l2_buffer(vb, b);
546 EXPORT_SYMBOL(vb2_querybuf);
549 * __verify_userptr_ops() - verify that all memory operations required for
550 * USERPTR queue type have been provided
552 static int __verify_userptr_ops(struct vb2_queue *q)
554 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
555 !q->mem_ops->put_userptr)
562 * __verify_mmap_ops() - verify that all memory operations required for
563 * MMAP queue type have been provided
565 static int __verify_mmap_ops(struct vb2_queue *q)
567 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
568 !q->mem_ops->put || !q->mem_ops->mmap)
575 * __verify_dmabuf_ops() - verify that all memory operations required for
576 * DMABUF queue type have been provided
578 static int __verify_dmabuf_ops(struct vb2_queue *q)
580 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
581 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
582 !q->mem_ops->unmap_dmabuf)
589 * __verify_memory_type() - Check whether the memory type and buffer type
590 * passed to a buffer operation are compatible with the queue.
592 static int __verify_memory_type(struct vb2_queue *q,
593 enum v4l2_memory memory, enum v4l2_buf_type type)
595 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
596 memory != V4L2_MEMORY_DMABUF) {
597 dprintk(1, "reqbufs: unsupported memory type\n");
601 if (type != q->type) {
602 dprintk(1, "reqbufs: requested type is incorrect\n");
607 * Make sure all the required memory ops for given memory type
610 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
611 dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
615 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
616 dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
620 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
621 dprintk(1, "reqbufs: DMABUF for current setup unsupported\n");
626 * Place the busy tests at the end: -EBUSY can be ignored when
627 * create_bufs is called with count == 0, but count == 0 should still
628 * do the memory and type validation.
631 dprintk(1, "reqbufs: file io in progress\n");
638 * __reqbufs() - Initiate streaming
639 * @q: videobuf2 queue
640 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
642 * Should be called from vidioc_reqbufs ioctl handler of a driver.
644 * 1) verifies streaming parameters passed from the userspace,
645 * 2) sets up the queue,
646 * 3) negotiates number of buffers and planes per buffer with the driver
647 * to be used during streaming,
648 * 4) allocates internal buffer structures (struct vb2_buffer), according to
649 * the agreed parameters,
650 * 5) for MMAP memory type, allocates actual video memory, using the
651 * memory handling/allocation routines provided during queue initialization
653 * If req->count is 0, all the memory will be freed instead.
654 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
655 * and the queue is not busy, memory will be reallocated.
657 * The return values from this function are intended to be directly returned
658 * from vidioc_reqbufs handler in driver.
660 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
662 unsigned int num_buffers, allocated_buffers, num_planes = 0;
666 dprintk(1, "reqbufs: streaming active\n");
670 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
672 * We already have buffers allocated, so first check if they
673 * are not in use and can be freed.
675 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
676 dprintk(1, "reqbufs: memory in use, cannot free\n");
680 ret = __vb2_queue_free(q, q->num_buffers);
685 * In case of REQBUFS(0) return immediately without calling
686 * driver's queue_setup() callback and allocating resources.
693 * Make sure the requested values and current defaults are sane.
695 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
696 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
697 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
698 q->memory = req->memory;
701 * Ask the driver how many buffers and planes per buffer it requires.
702 * Driver also sets the size and allocator context for each plane.
704 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
705 q->plane_sizes, q->alloc_ctx);
709 /* Finally, allocate buffers and video memory */
710 ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
712 dprintk(1, "Memory allocation failed\n");
716 allocated_buffers = ret;
719 * Check if driver can handle the allocated number of buffers.
721 if (allocated_buffers < num_buffers) {
722 num_buffers = allocated_buffers;
724 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
725 &num_planes, q->plane_sizes, q->alloc_ctx);
727 if (!ret && allocated_buffers < num_buffers)
731 * Either the driver has accepted a smaller number of buffers,
732 * or .queue_setup() returned an error
736 q->num_buffers = allocated_buffers;
739 __vb2_queue_free(q, allocated_buffers);
744 * Return the number of successfully allocated buffers
747 req->count = allocated_buffers;
748 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
754 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
756 * @q: videobuf2 queue
757 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
759 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
761 int ret = __verify_memory_type(q, req->memory, req->type);
763 return ret ? ret : __reqbufs(q, req);
765 EXPORT_SYMBOL_GPL(vb2_reqbufs);
768 * __create_bufs() - Allocate buffers and any required auxiliary structs
769 * @q: videobuf2 queue
770 * @create: creation parameters, passed from userspace to vidioc_create_bufs
773 * Should be called from vidioc_create_bufs ioctl handler of a driver.
775 * 1) verifies parameter sanity
776 * 2) calls the .queue_setup() queue operation
777 * 3) performs any necessary memory allocations
779 * The return values from this function are intended to be directly returned
780 * from vidioc_create_bufs handler in driver.
782 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
784 unsigned int num_planes = 0, num_buffers, allocated_buffers;
787 if (q->num_buffers == VIDEO_MAX_FRAME) {
788 dprintk(1, "%s(): maximum number of buffers already allocated\n",
793 if (!q->num_buffers) {
794 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
795 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
796 q->memory = create->memory;
797 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
800 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
803 * Ask the driver, whether the requested number of buffers, planes per
804 * buffer and their sizes are acceptable
806 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
807 &num_planes, q->plane_sizes, q->alloc_ctx);
811 /* Finally, allocate buffers and video memory */
812 ret = __vb2_queue_alloc(q, create->memory, num_buffers,
815 dprintk(1, "Memory allocation failed\n");
819 allocated_buffers = ret;
822 * Check if driver can handle the so far allocated number of buffers.
824 if (ret < num_buffers) {
828 * q->num_buffers contains the total number of buffers, that the
829 * queue driver has set up
831 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
832 &num_planes, q->plane_sizes, q->alloc_ctx);
834 if (!ret && allocated_buffers < num_buffers)
838 * Either the driver has accepted a smaller number of buffers,
839 * or .queue_setup() returned an error
843 q->num_buffers += allocated_buffers;
846 __vb2_queue_free(q, allocated_buffers);
851 * Return the number of successfully allocated buffers
854 create->count = allocated_buffers;
860 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
861 * memory and type values.
862 * @q: videobuf2 queue
863 * @create: creation parameters, passed from userspace to vidioc_create_bufs
866 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
868 int ret = __verify_memory_type(q, create->memory, create->format.type);
870 create->index = q->num_buffers;
871 if (create->count == 0)
872 return ret != -EBUSY ? ret : 0;
873 return ret ? ret : __create_bufs(q, create);
875 EXPORT_SYMBOL_GPL(vb2_create_bufs);
878 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
879 * @vb: vb2_buffer to which the plane in question belongs to
880 * @plane_no: plane number for which the address is to be returned
882 * This function returns a kernel virtual address of a given plane if
883 * such a mapping exist, NULL otherwise.
885 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
887 struct vb2_queue *q = vb->vb2_queue;
889 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
892 return call_memop(q, vaddr, vb->planes[plane_no].mem_priv);
895 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
898 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
899 * @vb: vb2_buffer to which the plane in question belongs to
900 * @plane_no: plane number for which the cookie is to be returned
902 * This function returns an allocator specific cookie for a given plane if
903 * available, NULL otherwise. The allocator should provide some simple static
904 * inline function, which would convert this cookie to the allocator specific
905 * type that can be used directly by the driver to access the buffer. This can
906 * be for example physical address, pointer to scatter list or IOMMU mapping.
908 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
910 struct vb2_queue *q = vb->vb2_queue;
912 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
915 return call_memop(q, cookie, vb->planes[plane_no].mem_priv);
917 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
920 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
921 * @vb: vb2_buffer returned from the driver
922 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
923 * or VB2_BUF_STATE_ERROR if the operation finished with an error
925 * This function should be called by the driver after a hardware operation on
926 * a buffer is finished and the buffer may be returned to userspace. The driver
927 * cannot use this buffer anymore until it is queued back to it by videobuf
928 * by the means of buf_queue callback. Only buffers previously queued to the
929 * driver by buf_queue can be passed to this function.
931 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
933 struct vb2_queue *q = vb->vb2_queue;
937 if (vb->state != VB2_BUF_STATE_ACTIVE)
940 if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
943 dprintk(4, "Done processing on buffer %d, state: %d\n",
944 vb->v4l2_buf.index, state);
947 for (plane = 0; plane < vb->num_planes; ++plane)
948 call_memop(q, finish, vb->planes[plane].mem_priv);
950 /* Add the buffer to the done buffers list */
951 spin_lock_irqsave(&q->done_lock, flags);
953 list_add_tail(&vb->done_entry, &q->done_list);
954 atomic_dec(&q->queued_count);
955 spin_unlock_irqrestore(&q->done_lock, flags);
957 /* Inform any processes that may be waiting for buffers */
958 wake_up(&q->done_wq);
960 EXPORT_SYMBOL_GPL(vb2_buffer_done);
963 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
964 * v4l2_buffer by the userspace. The caller has already verified that struct
965 * v4l2_buffer has a valid number of planes.
967 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
968 struct v4l2_plane *v4l2_planes)
972 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
973 /* Fill in driver-provided information for OUTPUT types */
974 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
976 * Will have to go up to b->length when API starts
977 * accepting variable number of planes.
979 for (plane = 0; plane < vb->num_planes; ++plane) {
980 v4l2_planes[plane].bytesused =
981 b->m.planes[plane].bytesused;
982 v4l2_planes[plane].data_offset =
983 b->m.planes[plane].data_offset;
987 if (b->memory == V4L2_MEMORY_USERPTR) {
988 for (plane = 0; plane < vb->num_planes; ++plane) {
989 v4l2_planes[plane].m.userptr =
990 b->m.planes[plane].m.userptr;
991 v4l2_planes[plane].length =
992 b->m.planes[plane].length;
995 if (b->memory == V4L2_MEMORY_DMABUF) {
996 for (plane = 0; plane < vb->num_planes; ++plane) {
997 v4l2_planes[plane].m.fd =
998 b->m.planes[plane].m.fd;
999 v4l2_planes[plane].length =
1000 b->m.planes[plane].length;
1001 v4l2_planes[plane].data_offset =
1002 b->m.planes[plane].data_offset;
1007 * Single-planar buffers do not use planes array,
1008 * so fill in relevant v4l2_buffer struct fields instead.
1009 * In videobuf we use our internal V4l2_planes struct for
1010 * single-planar buffers as well, for simplicity.
1012 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1013 v4l2_planes[0].bytesused = b->bytesused;
1014 v4l2_planes[0].data_offset = 0;
1017 if (b->memory == V4L2_MEMORY_USERPTR) {
1018 v4l2_planes[0].m.userptr = b->m.userptr;
1019 v4l2_planes[0].length = b->length;
1022 if (b->memory == V4L2_MEMORY_DMABUF) {
1023 v4l2_planes[0].m.fd = b->m.fd;
1024 v4l2_planes[0].length = b->length;
1025 v4l2_planes[0].data_offset = 0;
1030 vb->v4l2_buf.field = b->field;
1031 vb->v4l2_buf.timestamp = b->timestamp;
1032 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1036 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1038 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1040 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1041 struct vb2_queue *q = vb->vb2_queue;
1045 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1047 /* Copy relevant information provided by the userspace */
1048 __fill_vb2_buffer(vb, b, planes);
1050 for (plane = 0; plane < vb->num_planes; ++plane) {
1051 /* Skip the plane if already verified */
1052 if (vb->v4l2_planes[plane].m.userptr &&
1053 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1054 && vb->v4l2_planes[plane].length == planes[plane].length)
1057 dprintk(3, "qbuf: userspace address for plane %d changed, "
1058 "reacquiring memory\n", plane);
1060 /* Check if the provided plane buffer is large enough */
1061 if (planes[plane].length < q->plane_sizes[plane]) {
1062 dprintk(1, "qbuf: provided buffer size %u is less than "
1063 "setup size %u for plane %d\n",
1064 planes[plane].length,
1065 q->plane_sizes[plane], plane);
1070 /* Release previously acquired memory if present */
1071 if (vb->planes[plane].mem_priv)
1072 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1074 vb->planes[plane].mem_priv = NULL;
1075 vb->v4l2_planes[plane].m.userptr = 0;
1076 vb->v4l2_planes[plane].length = 0;
1078 /* Acquire each plane's memory */
1079 mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
1080 planes[plane].m.userptr,
1081 planes[plane].length, write);
1082 if (IS_ERR_OR_NULL(mem_priv)) {
1083 dprintk(1, "qbuf: failed acquiring userspace "
1084 "memory for plane %d\n", plane);
1085 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1088 vb->planes[plane].mem_priv = mem_priv;
1092 * Call driver-specific initialization on the newly acquired buffer,
1095 ret = call_qop(q, buf_init, vb);
1097 dprintk(1, "qbuf: buffer initialization failed\n");
1102 * Now that everything is in order, copy relevant information
1103 * provided by userspace.
1105 for (plane = 0; plane < vb->num_planes; ++plane)
1106 vb->v4l2_planes[plane] = planes[plane];
1110 /* In case of errors, release planes that were already acquired */
1111 for (plane = 0; plane < vb->num_planes; ++plane) {
1112 if (vb->planes[plane].mem_priv)
1113 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1114 vb->planes[plane].mem_priv = NULL;
1115 vb->v4l2_planes[plane].m.userptr = 0;
1116 vb->v4l2_planes[plane].length = 0;
1123 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1125 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1127 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1132 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1134 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1136 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1137 struct vb2_queue *q = vb->vb2_queue;
1141 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1143 /* Copy relevant information provided by the userspace */
1144 __fill_vb2_buffer(vb, b, planes);
1146 for (plane = 0; plane < vb->num_planes; ++plane) {
1147 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1149 if (IS_ERR_OR_NULL(dbuf)) {
1150 dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
1156 /* use DMABUF size if length is not provided */
1157 if (planes[plane].length == 0)
1158 planes[plane].length = dbuf->size;
1160 if (planes[plane].length < planes[plane].data_offset +
1161 q->plane_sizes[plane]) {
1162 dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
1168 /* Skip the plane if already verified */
1169 if (dbuf == vb->planes[plane].dbuf &&
1170 vb->v4l2_planes[plane].length == planes[plane].length) {
1175 dprintk(1, "qbuf: buffer for plane %d changed\n", plane);
1177 /* Release previously acquired memory if present */
1178 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
1179 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1181 /* Acquire each plane's memory */
1182 mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],
1183 dbuf, planes[plane].length, write);
1184 if (IS_ERR(mem_priv)) {
1185 dprintk(1, "qbuf: failed to attach dmabuf\n");
1186 ret = PTR_ERR(mem_priv);
1191 vb->planes[plane].dbuf = dbuf;
1192 vb->planes[plane].mem_priv = mem_priv;
1195 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1196 * really we want to do this just before the DMA, not while queueing
1199 for (plane = 0; plane < vb->num_planes; ++plane) {
1200 ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);
1202 dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
1206 vb->planes[plane].dbuf_mapped = 1;
1210 * Call driver-specific initialization on the newly acquired buffer,
1213 ret = call_qop(q, buf_init, vb);
1215 dprintk(1, "qbuf: buffer initialization failed\n");
1220 * Now that everything is in order, copy relevant information
1221 * provided by userspace.
1223 for (plane = 0; plane < vb->num_planes; ++plane)
1224 vb->v4l2_planes[plane] = planes[plane];
1228 /* In case of errors, release planes that were already acquired */
1229 __vb2_buf_dmabuf_put(vb);
1235 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1237 static void __enqueue_in_driver(struct vb2_buffer *vb)
1239 struct vb2_queue *q = vb->vb2_queue;
1242 vb->state = VB2_BUF_STATE_ACTIVE;
1243 atomic_inc(&q->queued_count);
1246 for (plane = 0; plane < vb->num_planes; ++plane)
1247 call_memop(q, prepare, vb->planes[plane].mem_priv);
1249 q->ops->buf_queue(vb);
1252 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1254 struct vb2_queue *q = vb->vb2_queue;
1255 struct rw_semaphore *mmap_sem;
1258 ret = __verify_length(vb, b);
1260 dprintk(1, "%s(): plane parameters verification failed: %d\n",
1265 vb->state = VB2_BUF_STATE_PREPARING;
1266 switch (q->memory) {
1267 case V4L2_MEMORY_MMAP:
1268 ret = __qbuf_mmap(vb, b);
1270 case V4L2_MEMORY_USERPTR:
1272 * In case of user pointer buffers vb2 allocators need to get
1273 * direct access to userspace pages. This requires getting
1274 * the mmap semaphore for read access in the current process
1275 * structure. The same semaphore is taken before calling mmap
1276 * operation, while both qbuf/prepare_buf and mmap are called
1277 * by the driver or v4l2 core with the driver's lock held.
1278 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1279 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1280 * the videobuf2 core releases the driver's lock, takes
1281 * mmap_sem and then takes the driver's lock again.
1283 mmap_sem = ¤t->mm->mmap_sem;
1284 call_qop(q, wait_prepare, q);
1285 down_read(mmap_sem);
1286 call_qop(q, wait_finish, q);
1288 ret = __qbuf_userptr(vb, b);
1292 case V4L2_MEMORY_DMABUF:
1293 ret = __qbuf_dmabuf(vb, b);
1296 WARN(1, "Invalid queue type\n");
1301 ret = call_qop(q, buf_prepare, vb);
1303 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
1304 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1309 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1312 if (b->type != q->type) {
1313 dprintk(1, "%s(): invalid buffer type\n", opname);
1317 if (b->index >= q->num_buffers) {
1318 dprintk(1, "%s(): buffer index out of range\n", opname);
1322 if (q->bufs[b->index] == NULL) {
1323 /* Should never happen */
1324 dprintk(1, "%s(): buffer is NULL\n", opname);
1328 if (b->memory != q->memory) {
1329 dprintk(1, "%s(): invalid memory type\n", opname);
1333 return __verify_planes_array(q->bufs[b->index], b);
1337 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1338 * @q: videobuf2 queue
1339 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1342 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1344 * 1) verifies the passed buffer,
1345 * 2) calls buf_prepare callback in the driver (if provided), in which
1346 * driver-specific buffer initialization can be performed,
1348 * The return values from this function are intended to be directly returned
1349 * from vidioc_prepare_buf handler in driver.
1351 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1353 struct vb2_buffer *vb;
1357 dprintk(1, "%s(): file io in progress\n", __func__);
1361 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1365 vb = q->bufs[b->index];
1366 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1367 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1372 ret = __buf_prepare(vb, b);
1374 /* Fill buffer information for the userspace */
1375 __fill_v4l2_buffer(vb, b);
1377 dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
1381 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1384 * vb2_start_streaming() - Attempt to start streaming.
1385 * @q: videobuf2 queue
1387 * If there are not enough buffers, then retry_start_streaming is set to
1388 * 1 and 0 is returned. The next time a buffer is queued and
1389 * retry_start_streaming is 1, this function will be called again to
1390 * retry starting the DMA engine.
1392 static int vb2_start_streaming(struct vb2_queue *q)
1396 /* Tell the driver to start streaming */
1397 ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
1400 * If there are not enough buffers queued to start streaming, then
1401 * the start_streaming operation will return -ENOBUFS and you have to
1402 * retry when the next buffer is queued.
1404 if (ret == -ENOBUFS) {
1405 dprintk(1, "qbuf: not enough buffers, retry when more buffers are queued.\n");
1406 q->retry_start_streaming = 1;
1410 dprintk(1, "qbuf: driver refused to start streaming\n");
1412 q->retry_start_streaming = 0;
1416 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1418 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1419 struct vb2_buffer *vb;
1424 vb = q->bufs[b->index];
1425 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1426 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1431 switch (vb->state) {
1432 case VB2_BUF_STATE_DEQUEUED:
1433 ret = __buf_prepare(vb, b);
1437 case VB2_BUF_STATE_PREPARED:
1439 case VB2_BUF_STATE_PREPARING:
1440 dprintk(1, "qbuf: buffer still being prepared\n");
1443 dprintk(1, "qbuf: buffer already in use\n");
1448 * Add to the queued buffers list, a buffer will stay on it until
1449 * dequeued in dqbuf.
1451 list_add_tail(&vb->queued_entry, &q->queued_list);
1452 q->waiting_for_buffers = false;
1453 vb->state = VB2_BUF_STATE_QUEUED;
1456 * If already streaming, give the buffer to driver for processing.
1457 * If not, the buffer will be given to driver on next streamon.
1460 __enqueue_in_driver(vb);
1462 /* Fill buffer information for the userspace */
1463 __fill_v4l2_buffer(vb, b);
1465 if (q->retry_start_streaming) {
1466 ret = vb2_start_streaming(q);
1471 dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
1476 * vb2_qbuf() - Queue a buffer from userspace
1477 * @q: videobuf2 queue
1478 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1481 * Should be called from vidioc_qbuf ioctl handler of a driver.
1483 * 1) verifies the passed buffer,
1484 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1485 * which driver-specific buffer initialization can be performed,
1486 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1487 * callback for processing.
1489 * The return values from this function are intended to be directly returned
1490 * from vidioc_qbuf handler in driver.
1492 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1495 dprintk(1, "%s(): file io in progress\n", __func__);
1499 return vb2_internal_qbuf(q, b);
1501 EXPORT_SYMBOL_GPL(vb2_qbuf);
1504 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1507 * Will sleep if required for nonblocking == false.
1509 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1512 * All operations on vb_done_list are performed under done_lock
1513 * spinlock protection. However, buffers may be removed from
1514 * it and returned to userspace only while holding both driver's
1515 * lock and the done_lock spinlock. Thus we can be sure that as
1516 * long as we hold the driver's lock, the list will remain not
1517 * empty if list_empty() check succeeds.
1523 if (!q->streaming) {
1524 dprintk(1, "Streaming off, will not wait for buffers\n");
1528 if (!list_empty(&q->done_list)) {
1530 * Found a buffer that we were waiting for.
1536 dprintk(1, "Nonblocking and no buffers to dequeue, "
1542 * We are streaming and blocking, wait for another buffer to
1543 * become ready or for streamoff. Driver's lock is released to
1544 * allow streamoff or qbuf to be called while waiting.
1546 call_qop(q, wait_prepare, q);
1549 * All locks have been released, it is safe to sleep now.
1551 dprintk(3, "Will sleep waiting for buffers\n");
1552 ret = wait_event_interruptible(q->done_wq,
1553 !list_empty(&q->done_list) || !q->streaming);
1556 * We need to reevaluate both conditions again after reacquiring
1557 * the locks or return an error if one occurred.
1559 call_qop(q, wait_finish, q);
1561 dprintk(1, "Sleep was interrupted\n");
1569 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1571 * Will sleep if required for nonblocking == false.
1573 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1574 struct v4l2_buffer *b, int nonblocking)
1576 unsigned long flags;
1580 * Wait for at least one buffer to become available on the done_list.
1582 ret = __vb2_wait_for_done_vb(q, nonblocking);
1587 * Driver's lock has been held since we last verified that done_list
1588 * is not empty, so no need for another list_empty(done_list) check.
1590 spin_lock_irqsave(&q->done_lock, flags);
1591 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1593 * Only remove the buffer from done_list if v4l2_buffer can handle all
1596 ret = __verify_planes_array(*vb, b);
1598 list_del(&(*vb)->done_entry);
1599 spin_unlock_irqrestore(&q->done_lock, flags);
1605 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1606 * @q: videobuf2 queue
1608 * This function will wait until all buffers that have been given to the driver
1609 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1610 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1611 * taken, for example from stop_streaming() callback.
1613 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1615 if (!q->streaming) {
1616 dprintk(1, "Streaming off, will not wait for buffers\n");
1620 if (!q->retry_start_streaming)
1621 wait_event(q->done_wq, !atomic_read(&q->queued_count));
1624 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1627 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1629 static void __vb2_dqbuf(struct vb2_buffer *vb)
1631 struct vb2_queue *q = vb->vb2_queue;
1634 /* nothing to do if the buffer is already dequeued */
1635 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1638 vb->state = VB2_BUF_STATE_DEQUEUED;
1640 /* unmap DMABUF buffer */
1641 if (q->memory == V4L2_MEMORY_DMABUF)
1642 for (i = 0; i < vb->num_planes; ++i) {
1643 if (!vb->planes[i].dbuf_mapped)
1645 call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
1646 vb->planes[i].dbuf_mapped = 0;
1650 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1652 struct vb2_buffer *vb = NULL;
1655 if (b->type != q->type) {
1656 dprintk(1, "dqbuf: invalid buffer type\n");
1659 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
1663 ret = call_qop(q, buf_finish, vb);
1665 dprintk(1, "dqbuf: buffer finish failed\n");
1669 switch (vb->state) {
1670 case VB2_BUF_STATE_DONE:
1671 dprintk(3, "dqbuf: Returning done buffer\n");
1673 case VB2_BUF_STATE_ERROR:
1674 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1677 dprintk(1, "dqbuf: Invalid buffer state\n");
1681 /* Fill buffer information for the userspace */
1682 __fill_v4l2_buffer(vb, b);
1683 /* Remove from videobuf queue */
1684 list_del(&vb->queued_entry);
1685 /* go back to dequeued state */
1688 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1689 vb->v4l2_buf.index, vb->state);
1695 * vb2_dqbuf() - Dequeue a buffer to the userspace
1696 * @q: videobuf2 queue
1697 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1699 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1700 * buffers ready for dequeuing are present. Normally the driver
1701 * would be passing (file->f_flags & O_NONBLOCK) here
1703 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1705 * 1) verifies the passed buffer,
1706 * 2) calls buf_finish callback in the driver (if provided), in which
1707 * driver can perform any additional operations that may be required before
1708 * returning the buffer to userspace, such as cache sync,
1709 * 3) the buffer struct members are filled with relevant information for
1712 * The return values from this function are intended to be directly returned
1713 * from vidioc_dqbuf handler in driver.
1715 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1718 dprintk(1, "dqbuf: file io in progress\n");
1721 return vb2_internal_dqbuf(q, b, nonblocking);
1723 EXPORT_SYMBOL_GPL(vb2_dqbuf);
1726 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1728 * Removes all queued buffers from driver's queue and all buffers queued by
1729 * userspace from videobuf's queue. Returns to state after reqbufs.
1731 static void __vb2_queue_cancel(struct vb2_queue *q)
1735 if (q->retry_start_streaming) {
1736 q->retry_start_streaming = 0;
1741 * Tell driver to stop all transactions and release all queued
1745 call_qop(q, stop_streaming, q);
1749 * Remove all buffers from videobuf's list...
1751 INIT_LIST_HEAD(&q->queued_list);
1753 * ...and done list; userspace will not receive any buffers it
1754 * has not already dequeued before initiating cancel.
1756 INIT_LIST_HEAD(&q->done_list);
1757 atomic_set(&q->queued_count, 0);
1758 wake_up_all(&q->done_wq);
1761 * Reinitialize all buffers for next use.
1763 for (i = 0; i < q->num_buffers; ++i)
1764 __vb2_dqbuf(q->bufs[i]);
1767 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1769 struct vb2_buffer *vb;
1772 if (type != q->type) {
1773 dprintk(1, "streamon: invalid stream type\n");
1778 dprintk(3, "streamon successful: already streaming\n");
1782 if (!q->num_buffers) {
1783 dprintk(1, "streamon: no buffers have been allocated\n");
1788 * If any buffers were queued before streamon,
1789 * we can now pass them to driver for processing.
1791 list_for_each_entry(vb, &q->queued_list, queued_entry)
1792 __enqueue_in_driver(vb);
1794 /* Tell driver to start streaming. */
1795 ret = vb2_start_streaming(q);
1797 __vb2_queue_cancel(q);
1803 dprintk(3, "Streamon successful\n");
1808 * vb2_streamon - start streaming
1809 * @q: videobuf2 queue
1810 * @type: type argument passed from userspace to vidioc_streamon handler
1812 * Should be called from vidioc_streamon handler of a driver.
1814 * 1) verifies current state
1815 * 2) passes any previously queued buffers to the driver and starts streaming
1817 * The return values from this function are intended to be directly returned
1818 * from vidioc_streamon handler in the driver.
1820 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1823 dprintk(1, "streamon: file io in progress\n");
1826 return vb2_internal_streamon(q, type);
1828 EXPORT_SYMBOL_GPL(vb2_streamon);
1830 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1832 if (type != q->type) {
1833 dprintk(1, "streamoff: invalid stream type\n");
1837 if (!q->streaming) {
1838 dprintk(3, "streamoff successful: not streaming\n");
1843 * Cancel will pause streaming and remove all buffers from the driver
1844 * and videobuf, effectively returning control over them to userspace.
1846 __vb2_queue_cancel(q);
1847 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1849 dprintk(3, "Streamoff successful\n");
1854 * vb2_streamoff - stop streaming
1855 * @q: videobuf2 queue
1856 * @type: type argument passed from userspace to vidioc_streamoff handler
1858 * Should be called from vidioc_streamoff handler of a driver.
1860 * 1) verifies current state,
1861 * 2) stop streaming and dequeues any queued buffers, including those previously
1862 * passed to the driver (after waiting for the driver to finish).
1864 * This call can be used for pausing playback.
1865 * The return values from this function are intended to be directly returned
1866 * from vidioc_streamoff handler in the driver
1868 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1871 dprintk(1, "streamoff: file io in progress\n");
1874 return vb2_internal_streamoff(q, type);
1876 EXPORT_SYMBOL_GPL(vb2_streamoff);
1879 * __find_plane_by_offset() - find plane associated with the given offset off
1881 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1882 unsigned int *_buffer, unsigned int *_plane)
1884 struct vb2_buffer *vb;
1885 unsigned int buffer, plane;
1888 * Go over all buffers and their planes, comparing the given offset
1889 * with an offset assigned to each plane. If a match is found,
1890 * return its buffer and plane numbers.
1892 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1893 vb = q->bufs[buffer];
1895 for (plane = 0; plane < vb->num_planes; ++plane) {
1896 if (vb->v4l2_planes[plane].m.mem_offset == off) {
1908 * vb2_expbuf() - Export a buffer as a file descriptor
1909 * @q: videobuf2 queue
1910 * @eb: export buffer structure passed from userspace to vidioc_expbuf
1913 * The return values from this function are intended to be directly returned
1914 * from vidioc_expbuf handler in driver.
1916 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
1918 struct vb2_buffer *vb = NULL;
1919 struct vb2_plane *vb_plane;
1921 struct dma_buf *dbuf;
1923 if (q->memory != V4L2_MEMORY_MMAP) {
1924 dprintk(1, "Queue is not currently set up for mmap\n");
1928 if (!q->mem_ops->get_dmabuf) {
1929 dprintk(1, "Queue does not support DMA buffer exporting\n");
1933 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
1934 dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
1938 if (eb->type != q->type) {
1939 dprintk(1, "qbuf: invalid buffer type\n");
1943 if (eb->index >= q->num_buffers) {
1944 dprintk(1, "buffer index out of range\n");
1948 vb = q->bufs[eb->index];
1950 if (eb->plane >= vb->num_planes) {
1951 dprintk(1, "buffer plane out of range\n");
1955 vb_plane = &vb->planes[eb->plane];
1957 dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
1958 if (IS_ERR_OR_NULL(dbuf)) {
1959 dprintk(1, "Failed to export buffer %d, plane %d\n",
1960 eb->index, eb->plane);
1964 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
1966 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1967 eb->index, eb->plane, ret);
1972 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1973 eb->index, eb->plane, ret);
1978 EXPORT_SYMBOL_GPL(vb2_expbuf);
1981 * vb2_mmap() - map video buffers into application address space
1982 * @q: videobuf2 queue
1983 * @vma: vma passed to the mmap file operation handler in the driver
1985 * Should be called from mmap file operation handler of a driver.
1986 * This function maps one plane of one of the available video buffers to
1987 * userspace. To map whole video memory allocated on reqbufs, this function
1988 * has to be called once per each plane per each buffer previously allocated.
1990 * When the userspace application calls mmap, it passes to it an offset returned
1991 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1992 * a "cookie", which is then used to identify the plane to be mapped.
1993 * This function finds a plane with a matching offset and a mapping is performed
1994 * by the means of a provided memory operation.
1996 * The return values from this function are intended to be directly returned
1997 * from the mmap handler in driver.
1999 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2001 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2002 struct vb2_buffer *vb;
2003 unsigned int buffer, plane;
2005 unsigned long length;
2007 if (q->memory != V4L2_MEMORY_MMAP) {
2008 dprintk(1, "Queue is not currently set up for mmap\n");
2013 * Check memory area access mode.
2015 if (!(vma->vm_flags & VM_SHARED)) {
2016 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
2019 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2020 if (!(vma->vm_flags & VM_WRITE)) {
2021 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
2025 if (!(vma->vm_flags & VM_READ)) {
2026 dprintk(1, "Invalid vma flags, VM_READ needed\n");
2032 * Find the plane corresponding to the offset passed by userspace.
2034 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2038 vb = q->bufs[buffer];
2041 * MMAP requires page_aligned buffers.
2042 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2043 * so, we need to do the same here.
2045 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2046 if (length < (vma->vm_end - vma->vm_start)) {
2048 "MMAP invalid, as it would overflow buffer length\n");
2052 ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
2056 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
2059 EXPORT_SYMBOL_GPL(vb2_mmap);
2062 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2065 unsigned long pgoff,
2066 unsigned long flags)
2068 unsigned long off = pgoff << PAGE_SHIFT;
2069 struct vb2_buffer *vb;
2070 unsigned int buffer, plane;
2073 if (q->memory != V4L2_MEMORY_MMAP) {
2074 dprintk(1, "Queue is not currently set up for mmap\n");
2079 * Find the plane corresponding to the offset passed by userspace.
2081 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2085 vb = q->bufs[buffer];
2087 return (unsigned long)vb2_plane_vaddr(vb, plane);
2089 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2092 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2093 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2096 * vb2_poll() - implements poll userspace operation
2097 * @q: videobuf2 queue
2098 * @file: file argument passed to the poll file operation handler
2099 * @wait: wait argument passed to the poll file operation handler
2101 * This function implements poll file operation handler for a driver.
2102 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2103 * be informed that the file descriptor of a video device is available for
2105 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2106 * will be reported as available for writing.
2108 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2111 * The return values from this function are intended to be directly returned
2112 * from poll handler in driver.
2114 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2116 struct video_device *vfd = video_devdata(file);
2117 unsigned long req_events = poll_requested_events(wait);
2118 struct vb2_buffer *vb = NULL;
2119 unsigned int res = 0;
2120 unsigned long flags;
2122 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2123 struct v4l2_fh *fh = file->private_data;
2125 if (v4l2_event_pending(fh))
2127 else if (req_events & POLLPRI)
2128 poll_wait(file, &fh->wait, wait);
2131 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2133 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2137 * Start file I/O emulator only if streaming API has not been used yet.
2139 if (q->num_buffers == 0 && q->fileio == NULL) {
2140 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2141 (req_events & (POLLIN | POLLRDNORM))) {
2142 if (__vb2_init_fileio(q, 1))
2143 return res | POLLERR;
2145 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2146 (req_events & (POLLOUT | POLLWRNORM))) {
2147 if (__vb2_init_fileio(q, 0))
2148 return res | POLLERR;
2150 * Write to OUTPUT queue can be done immediately.
2152 return res | POLLOUT | POLLWRNORM;
2157 * There is nothing to wait for if the queue isn't streaming.
2159 if (!vb2_is_streaming(q))
2160 return res | POLLERR;
2162 * For compatibility with vb1: if QBUF hasn't been called yet, then
2163 * return POLLERR as well. This only affects capture queues, output
2164 * queues will always initialize waiting_for_buffers to false.
2166 if (q->waiting_for_buffers)
2167 return res | POLLERR;
2169 if (list_empty(&q->done_list))
2170 poll_wait(file, &q->done_wq, wait);
2173 * Take first buffer available for dequeuing.
2175 spin_lock_irqsave(&q->done_lock, flags);
2176 if (!list_empty(&q->done_list))
2177 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2179 spin_unlock_irqrestore(&q->done_lock, flags);
2181 if (vb && (vb->state == VB2_BUF_STATE_DONE
2182 || vb->state == VB2_BUF_STATE_ERROR)) {
2183 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2184 res | POLLOUT | POLLWRNORM :
2185 res | POLLIN | POLLRDNORM;
2189 EXPORT_SYMBOL_GPL(vb2_poll);
2192 * vb2_queue_init() - initialize a videobuf2 queue
2193 * @q: videobuf2 queue; this structure should be allocated in driver
2195 * The vb2_queue structure should be allocated by the driver. The driver is
2196 * responsible of clearing it's content and setting initial values for some
2197 * required entries before calling this function.
2198 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2199 * to the struct vb2_queue description in include/media/videobuf2-core.h
2200 * for more information.
2202 int vb2_queue_init(struct vb2_queue *q)
2209 WARN_ON(!q->mem_ops) ||
2210 WARN_ON(!q->type) ||
2211 WARN_ON(!q->io_modes) ||
2212 WARN_ON(!q->ops->queue_setup) ||
2213 WARN_ON(!q->ops->buf_queue) ||
2214 WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK))
2217 /* Warn that the driver should choose an appropriate timestamp type */
2218 WARN_ON(q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2220 INIT_LIST_HEAD(&q->queued_list);
2221 INIT_LIST_HEAD(&q->done_list);
2222 spin_lock_init(&q->done_lock);
2223 init_waitqueue_head(&q->done_wq);
2225 if (q->buf_struct_size == 0)
2226 q->buf_struct_size = sizeof(struct vb2_buffer);
2230 EXPORT_SYMBOL_GPL(vb2_queue_init);
2233 * vb2_queue_release() - stop streaming, release the queue and free memory
2234 * @q: videobuf2 queue
2236 * This function stops streaming and performs necessary clean ups, including
2237 * freeing video buffer memory. The driver is responsible for freeing
2238 * the vb2_queue structure itself.
2240 void vb2_queue_release(struct vb2_queue *q)
2242 __vb2_cleanup_fileio(q);
2243 __vb2_queue_cancel(q);
2244 __vb2_queue_free(q, q->num_buffers);
2246 EXPORT_SYMBOL_GPL(vb2_queue_release);
2249 * struct vb2_fileio_buf - buffer context used by file io emulator
2251 * vb2 provides a compatibility layer and emulator of file io (read and
2252 * write) calls on top of streaming API. This structure is used for
2253 * tracking context related to the buffers.
2255 struct vb2_fileio_buf {
2259 unsigned int queued:1;
2263 * struct vb2_fileio_data - queue context used by file io emulator
2265 * vb2 provides a compatibility layer and emulator of file io (read and
2266 * write) calls on top of streaming API. For proper operation it required
2267 * this structure to save the driver state between each call of the read
2268 * or write function.
2270 struct vb2_fileio_data {
2271 struct v4l2_requestbuffers req;
2272 struct v4l2_buffer b;
2273 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2275 unsigned int q_count;
2276 unsigned int dq_count;
2281 * __vb2_init_fileio() - initialize file io emulator
2282 * @q: videobuf2 queue
2283 * @read: mode selector (1 means read, 0 means write)
2285 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2287 struct vb2_fileio_data *fileio;
2289 unsigned int count = 0;
2294 if ((read && !(q->io_modes & VB2_READ)) ||
2295 (!read && !(q->io_modes & VB2_WRITE)))
2299 * Check if device supports mapping buffers to kernel virtual space.
2301 if (!q->mem_ops->vaddr)
2305 * Check if streaming api has not been already activated.
2307 if (q->streaming || q->num_buffers > 0)
2311 * Start with count 1, driver can increase it in queue_setup()
2315 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2316 (read) ? "read" : "write", count, q->io_flags);
2318 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2322 fileio->flags = q->io_flags;
2325 * Request buffers and use MMAP type to force driver
2326 * to allocate buffers by itself.
2328 fileio->req.count = count;
2329 fileio->req.memory = V4L2_MEMORY_MMAP;
2330 fileio->req.type = q->type;
2331 ret = vb2_reqbufs(q, &fileio->req);
2336 * Check if plane_count is correct
2337 * (multiplane buffers are not supported).
2339 if (q->bufs[0]->num_planes != 1) {
2345 * Get kernel address of each buffer.
2347 for (i = 0; i < q->num_buffers; i++) {
2348 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2349 if (fileio->bufs[i].vaddr == NULL) {
2353 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2357 * Read mode requires pre queuing of all buffers.
2361 * Queue all buffers.
2363 for (i = 0; i < q->num_buffers; i++) {
2364 struct v4l2_buffer *b = &fileio->b;
2365 memset(b, 0, sizeof(*b));
2367 b->memory = q->memory;
2369 ret = vb2_qbuf(q, b);
2372 fileio->bufs[i].queued = 1;
2374 fileio->index = q->num_buffers;
2380 ret = vb2_streamon(q, q->type);
2389 fileio->req.count = 0;
2390 vb2_reqbufs(q, &fileio->req);
2398 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2399 * @q: videobuf2 queue
2401 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2403 struct vb2_fileio_data *fileio = q->fileio;
2406 vb2_internal_streamoff(q, q->type);
2408 fileio->req.count = 0;
2409 vb2_reqbufs(q, &fileio->req);
2411 dprintk(3, "file io emulator closed\n");
2417 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2418 * @q: videobuf2 queue
2419 * @data: pointed to target userspace buffer
2420 * @count: number of bytes to read or write
2421 * @ppos: file handle position tracking pointer
2422 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2423 * @read: access mode selector (1 means read, 0 means write)
2425 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2426 loff_t *ppos, int nonblock, int read)
2428 struct vb2_fileio_data *fileio;
2429 struct vb2_fileio_buf *buf;
2432 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
2433 read ? "read" : "write", (long)*ppos, count,
2434 nonblock ? "non" : "");
2440 * Initialize emulator on first call.
2443 ret = __vb2_init_fileio(q, read);
2444 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2451 * Check if we need to dequeue the buffer.
2453 index = fileio->index;
2454 if (index >= q->num_buffers) {
2456 * Call vb2_dqbuf to get buffer back.
2458 memset(&fileio->b, 0, sizeof(fileio->b));
2459 fileio->b.type = q->type;
2460 fileio->b.memory = q->memory;
2461 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
2462 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2465 fileio->dq_count += 1;
2467 index = fileio->b.index;
2468 buf = &fileio->bufs[index];
2471 * Get number of bytes filled by the driver
2475 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2476 : vb2_plane_size(q->bufs[index], 0);
2478 buf = &fileio->bufs[index];
2482 * Limit count on last few bytes of the buffer.
2484 if (buf->pos + count > buf->size) {
2485 count = buf->size - buf->pos;
2486 dprintk(5, "reducing read count: %zd\n", count);
2490 * Transfer data to userspace.
2492 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
2493 count, index, buf->pos);
2495 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2497 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2499 dprintk(3, "file io: error copying data\n");
2510 * Queue next buffer if required.
2512 if (buf->pos == buf->size ||
2513 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
2515 * Check if this is the last buffer to read.
2517 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2518 fileio->dq_count == 1) {
2519 dprintk(3, "file io: read limit reached\n");
2520 return __vb2_cleanup_fileio(q);
2524 * Call vb2_qbuf and give buffer to the driver.
2526 memset(&fileio->b, 0, sizeof(fileio->b));
2527 fileio->b.type = q->type;
2528 fileio->b.memory = q->memory;
2529 fileio->b.index = index;
2530 fileio->b.bytesused = buf->pos;
2531 ret = vb2_internal_qbuf(q, &fileio->b);
2532 dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
2537 * Buffer has been queued, update the status
2541 buf->size = vb2_plane_size(q->bufs[index], 0);
2542 fileio->q_count += 1;
2543 if (fileio->index < q->num_buffers)
2548 * Return proper number of bytes processed.
2555 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2556 loff_t *ppos, int nonblocking)
2558 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2560 EXPORT_SYMBOL_GPL(vb2_read);
2562 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2563 loff_t *ppos, int nonblocking)
2565 return __vb2_perform_fileio(q, (char __user *) data, count,
2566 ppos, nonblocking, 0);
2568 EXPORT_SYMBOL_GPL(vb2_write);
2572 * The following functions are not part of the vb2 core API, but are helper
2573 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2574 * and struct vb2_ops.
2575 * They contain boilerplate code that most if not all drivers have to do
2576 * and so they simplify the driver code.
2579 /* The queue is busy if there is a owner and you are not that owner. */
2580 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
2582 return vdev->queue->owner && vdev->queue->owner != file->private_data;
2585 /* vb2 ioctl helpers */
2587 int vb2_ioctl_reqbufs(struct file *file, void *priv,
2588 struct v4l2_requestbuffers *p)
2590 struct video_device *vdev = video_devdata(file);
2591 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
2595 if (vb2_queue_is_busy(vdev, file))
2597 res = __reqbufs(vdev->queue, p);
2598 /* If count == 0, then the owner has released all buffers and he
2599 is no longer owner of the queue. Otherwise we have a new owner. */
2601 vdev->queue->owner = p->count ? file->private_data : NULL;
2604 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
2606 int vb2_ioctl_create_bufs(struct file *file, void *priv,
2607 struct v4l2_create_buffers *p)
2609 struct video_device *vdev = video_devdata(file);
2610 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
2612 p->index = vdev->queue->num_buffers;
2613 /* If count == 0, then just check if memory and type are valid.
2614 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
2616 return res != -EBUSY ? res : 0;
2619 if (vb2_queue_is_busy(vdev, file))
2621 res = __create_bufs(vdev->queue, p);
2623 vdev->queue->owner = file->private_data;
2626 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
2628 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
2629 struct v4l2_buffer *p)
2631 struct video_device *vdev = video_devdata(file);
2633 if (vb2_queue_is_busy(vdev, file))
2635 return vb2_prepare_buf(vdev->queue, p);
2637 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
2639 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
2641 struct video_device *vdev = video_devdata(file);
2643 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
2644 return vb2_querybuf(vdev->queue, p);
2646 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
2648 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2650 struct video_device *vdev = video_devdata(file);
2652 if (vb2_queue_is_busy(vdev, file))
2654 return vb2_qbuf(vdev->queue, p);
2656 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
2658 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2660 struct video_device *vdev = video_devdata(file);
2662 if (vb2_queue_is_busy(vdev, file))
2664 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
2666 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
2668 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
2670 struct video_device *vdev = video_devdata(file);
2672 if (vb2_queue_is_busy(vdev, file))
2674 return vb2_streamon(vdev->queue, i);
2676 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
2678 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
2680 struct video_device *vdev = video_devdata(file);
2682 if (vb2_queue_is_busy(vdev, file))
2684 return vb2_streamoff(vdev->queue, i);
2686 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
2688 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
2690 struct video_device *vdev = video_devdata(file);
2692 if (vb2_queue_is_busy(vdev, file))
2694 return vb2_expbuf(vdev->queue, p);
2696 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
2698 /* v4l2_file_operations helpers */
2700 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
2702 struct video_device *vdev = video_devdata(file);
2703 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2706 if (lock && mutex_lock_interruptible(lock))
2707 return -ERESTARTSYS;
2708 err = vb2_mmap(vdev->queue, vma);
2713 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
2715 int _vb2_fop_release(struct file *file, struct mutex *lock)
2717 struct video_device *vdev = video_devdata(file);
2719 if (file->private_data == vdev->queue->owner) {
2722 vb2_queue_release(vdev->queue);
2723 vdev->queue->owner = NULL;
2727 return v4l2_fh_release(file);
2729 EXPORT_SYMBOL_GPL(_vb2_fop_release);
2731 int vb2_fop_release(struct file *file)
2733 struct video_device *vdev = video_devdata(file);
2734 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2736 return _vb2_fop_release(file, lock);
2738 EXPORT_SYMBOL_GPL(vb2_fop_release);
2740 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
2741 size_t count, loff_t *ppos)
2743 struct video_device *vdev = video_devdata(file);
2744 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2747 if (lock && mutex_lock_interruptible(lock))
2748 return -ERESTARTSYS;
2749 if (vb2_queue_is_busy(vdev, file))
2751 err = vb2_write(vdev->queue, buf, count, ppos,
2752 file->f_flags & O_NONBLOCK);
2753 if (vdev->queue->fileio)
2754 vdev->queue->owner = file->private_data;
2760 EXPORT_SYMBOL_GPL(vb2_fop_write);
2762 ssize_t vb2_fop_read(struct file *file, char __user *buf,
2763 size_t count, loff_t *ppos)
2765 struct video_device *vdev = video_devdata(file);
2766 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2769 if (lock && mutex_lock_interruptible(lock))
2770 return -ERESTARTSYS;
2771 if (vb2_queue_is_busy(vdev, file))
2773 err = vb2_read(vdev->queue, buf, count, ppos,
2774 file->f_flags & O_NONBLOCK);
2775 if (vdev->queue->fileio)
2776 vdev->queue->owner = file->private_data;
2782 EXPORT_SYMBOL_GPL(vb2_fop_read);
2784 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
2786 struct video_device *vdev = video_devdata(file);
2787 struct vb2_queue *q = vdev->queue;
2788 struct mutex *lock = q->lock ? q->lock : vdev->lock;
2789 unsigned long req_events = poll_requested_events(wait);
2792 bool must_lock = false;
2794 /* Try to be smart: only lock if polling might start fileio,
2795 otherwise locking will only introduce unwanted delays. */
2796 if (q->num_buffers == 0 && q->fileio == NULL) {
2797 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2798 (req_events & (POLLIN | POLLRDNORM)))
2800 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2801 (req_events & (POLLOUT | POLLWRNORM)))
2805 /* If locking is needed, but this helper doesn't know how, then you
2806 shouldn't be using this helper but you should write your own. */
2807 WARN_ON(must_lock && !lock);
2809 if (must_lock && lock && mutex_lock_interruptible(lock))
2814 res = vb2_poll(vdev->queue, file, wait);
2816 /* If fileio was started, then we have a new queue owner. */
2817 if (must_lock && !fileio && q->fileio)
2818 q->owner = file->private_data;
2819 if (must_lock && lock)
2823 EXPORT_SYMBOL_GPL(vb2_fop_poll);
2826 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
2827 unsigned long len, unsigned long pgoff, unsigned long flags)
2829 struct video_device *vdev = video_devdata(file);
2830 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2833 if (lock && mutex_lock_interruptible(lock))
2834 return -ERESTARTSYS;
2835 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
2840 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
2843 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
2845 void vb2_ops_wait_prepare(struct vb2_queue *vq)
2847 mutex_unlock(vq->lock);
2849 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
2851 void vb2_ops_wait_finish(struct vb2_queue *vq)
2853 mutex_lock(vq->lock);
2855 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
2857 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
2858 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2859 MODULE_LICENSE("GPL");