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
;
753 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
755 * @q: videobuf2 queue
756 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
758 int vb2_reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
760 int ret
= __verify_memory_type(q
, req
->memory
, req
->type
);
762 return ret
? ret
: __reqbufs(q
, req
);
764 EXPORT_SYMBOL_GPL(vb2_reqbufs
);
767 * __create_bufs() - Allocate buffers and any required auxiliary structs
768 * @q: videobuf2 queue
769 * @create: creation parameters, passed from userspace to vidioc_create_bufs
772 * Should be called from vidioc_create_bufs ioctl handler of a driver.
774 * 1) verifies parameter sanity
775 * 2) calls the .queue_setup() queue operation
776 * 3) performs any necessary memory allocations
778 * The return values from this function are intended to be directly returned
779 * from vidioc_create_bufs handler in driver.
781 static int __create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
783 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
786 if (q
->num_buffers
== VIDEO_MAX_FRAME
) {
787 dprintk(1, "%s(): maximum number of buffers already allocated\n",
792 if (!q
->num_buffers
) {
793 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
794 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
795 q
->memory
= create
->memory
;
798 num_buffers
= min(create
->count
, VIDEO_MAX_FRAME
- q
->num_buffers
);
801 * Ask the driver, whether the requested number of buffers, planes per
802 * buffer and their sizes are acceptable
804 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
805 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
809 /* Finally, allocate buffers and video memory */
810 ret
= __vb2_queue_alloc(q
, create
->memory
, num_buffers
,
813 dprintk(1, "Memory allocation failed\n");
817 allocated_buffers
= ret
;
820 * Check if driver can handle the so far allocated number of buffers.
822 if (ret
< num_buffers
) {
826 * q->num_buffers contains the total number of buffers, that the
827 * queue driver has set up
829 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
830 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
832 if (!ret
&& allocated_buffers
< num_buffers
)
836 * Either the driver has accepted a smaller number of buffers,
837 * or .queue_setup() returned an error
841 q
->num_buffers
+= allocated_buffers
;
844 __vb2_queue_free(q
, allocated_buffers
);
849 * Return the number of successfully allocated buffers
852 create
->count
= allocated_buffers
;
858 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
859 * memory and type values.
860 * @q: videobuf2 queue
861 * @create: creation parameters, passed from userspace to vidioc_create_bufs
864 int vb2_create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
866 int ret
= __verify_memory_type(q
, create
->memory
, create
->format
.type
);
868 create
->index
= q
->num_buffers
;
869 if (create
->count
== 0)
870 return ret
!= -EBUSY
? ret
: 0;
871 return ret
? ret
: __create_bufs(q
, create
);
873 EXPORT_SYMBOL_GPL(vb2_create_bufs
);
876 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
877 * @vb: vb2_buffer to which the plane in question belongs to
878 * @plane_no: plane number for which the address is to be returned
880 * This function returns a kernel virtual address of a given plane if
881 * such a mapping exist, NULL otherwise.
883 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
885 struct vb2_queue
*q
= vb
->vb2_queue
;
887 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
890 return call_memop(q
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
893 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
896 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
897 * @vb: vb2_buffer to which the plane in question belongs to
898 * @plane_no: plane number for which the cookie is to be returned
900 * This function returns an allocator specific cookie for a given plane if
901 * available, NULL otherwise. The allocator should provide some simple static
902 * inline function, which would convert this cookie to the allocator specific
903 * type that can be used directly by the driver to access the buffer. This can
904 * be for example physical address, pointer to scatter list or IOMMU mapping.
906 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
908 struct vb2_queue
*q
= vb
->vb2_queue
;
910 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
913 return call_memop(q
, cookie
, vb
->planes
[plane_no
].mem_priv
);
915 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
918 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
919 * @vb: vb2_buffer returned from the driver
920 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
921 * or VB2_BUF_STATE_ERROR if the operation finished with an error
923 * This function should be called by the driver after a hardware operation on
924 * a buffer is finished and the buffer may be returned to userspace. The driver
925 * cannot use this buffer anymore until it is queued back to it by videobuf
926 * by the means of buf_queue callback. Only buffers previously queued to the
927 * driver by buf_queue can be passed to this function.
929 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
931 struct vb2_queue
*q
= vb
->vb2_queue
;
935 if (vb
->state
!= VB2_BUF_STATE_ACTIVE
)
938 if (state
!= VB2_BUF_STATE_DONE
&& state
!= VB2_BUF_STATE_ERROR
)
941 dprintk(4, "Done processing on buffer %d, state: %d\n",
942 vb
->v4l2_buf
.index
, state
);
945 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
946 call_memop(q
, finish
, vb
->planes
[plane
].mem_priv
);
948 /* Add the buffer to the done buffers list */
949 spin_lock_irqsave(&q
->done_lock
, flags
);
951 list_add_tail(&vb
->done_entry
, &q
->done_list
);
952 atomic_dec(&q
->queued_count
);
953 spin_unlock_irqrestore(&q
->done_lock
, flags
);
955 /* Inform any processes that may be waiting for buffers */
956 wake_up(&q
->done_wq
);
958 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
961 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
962 * v4l2_buffer by the userspace. The caller has already verified that struct
963 * v4l2_buffer has a valid number of planes.
965 static void __fill_vb2_buffer(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
,
966 struct v4l2_plane
*v4l2_planes
)
970 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
971 /* Fill in driver-provided information for OUTPUT types */
972 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
974 * Will have to go up to b->length when API starts
975 * accepting variable number of planes.
977 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
978 v4l2_planes
[plane
].bytesused
=
979 b
->m
.planes
[plane
].bytesused
;
980 v4l2_planes
[plane
].data_offset
=
981 b
->m
.planes
[plane
].data_offset
;
985 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
986 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
987 v4l2_planes
[plane
].m
.userptr
=
988 b
->m
.planes
[plane
].m
.userptr
;
989 v4l2_planes
[plane
].length
=
990 b
->m
.planes
[plane
].length
;
993 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
994 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
995 v4l2_planes
[plane
].m
.fd
=
996 b
->m
.planes
[plane
].m
.fd
;
997 v4l2_planes
[plane
].length
=
998 b
->m
.planes
[plane
].length
;
999 v4l2_planes
[plane
].data_offset
=
1000 b
->m
.planes
[plane
].data_offset
;
1005 * Single-planar buffers do not use planes array,
1006 * so fill in relevant v4l2_buffer struct fields instead.
1007 * In videobuf we use our internal V4l2_planes struct for
1008 * single-planar buffers as well, for simplicity.
1010 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1011 v4l2_planes
[0].bytesused
= b
->bytesused
;
1012 v4l2_planes
[0].data_offset
= 0;
1015 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1016 v4l2_planes
[0].m
.userptr
= b
->m
.userptr
;
1017 v4l2_planes
[0].length
= b
->length
;
1020 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1021 v4l2_planes
[0].m
.fd
= b
->m
.fd
;
1022 v4l2_planes
[0].length
= b
->length
;
1023 v4l2_planes
[0].data_offset
= 0;
1028 vb
->v4l2_buf
.field
= b
->field
;
1029 vb
->v4l2_buf
.timestamp
= b
->timestamp
;
1030 vb
->v4l2_buf
.flags
= b
->flags
& ~V4L2_BUFFER_MASK_FLAGS
;
1034 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1036 static int __qbuf_userptr(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1038 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1039 struct vb2_queue
*q
= vb
->vb2_queue
;
1043 int write
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1045 /* Copy relevant information provided by the userspace */
1046 __fill_vb2_buffer(vb
, b
, planes
);
1048 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1049 /* Skip the plane if already verified */
1050 if (vb
->v4l2_planes
[plane
].m
.userptr
&&
1051 vb
->v4l2_planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1052 && vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
)
1055 dprintk(3, "qbuf: userspace address for plane %d changed, "
1056 "reacquiring memory\n", plane
);
1058 /* Check if the provided plane buffer is large enough */
1059 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1060 dprintk(1, "qbuf: provided buffer size %u is less than "
1061 "setup size %u for plane %d\n",
1062 planes
[plane
].length
,
1063 q
->plane_sizes
[plane
], plane
);
1068 /* Release previously acquired memory if present */
1069 if (vb
->planes
[plane
].mem_priv
)
1070 call_memop(q
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1072 vb
->planes
[plane
].mem_priv
= NULL
;
1073 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1074 vb
->v4l2_planes
[plane
].length
= 0;
1076 /* Acquire each plane's memory */
1077 mem_priv
= call_memop(q
, get_userptr
, q
->alloc_ctx
[plane
],
1078 planes
[plane
].m
.userptr
,
1079 planes
[plane
].length
, write
);
1080 if (IS_ERR_OR_NULL(mem_priv
)) {
1081 dprintk(1, "qbuf: failed acquiring userspace "
1082 "memory for plane %d\n", plane
);
1083 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1086 vb
->planes
[plane
].mem_priv
= mem_priv
;
1090 * Call driver-specific initialization on the newly acquired buffer,
1093 ret
= call_qop(q
, buf_init
, vb
);
1095 dprintk(1, "qbuf: buffer initialization failed\n");
1100 * Now that everything is in order, copy relevant information
1101 * provided by userspace.
1103 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1104 vb
->v4l2_planes
[plane
] = planes
[plane
];
1108 /* In case of errors, release planes that were already acquired */
1109 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1110 if (vb
->planes
[plane
].mem_priv
)
1111 call_memop(q
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1112 vb
->planes
[plane
].mem_priv
= NULL
;
1113 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1114 vb
->v4l2_planes
[plane
].length
= 0;
1121 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1123 static int __qbuf_mmap(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1125 __fill_vb2_buffer(vb
, b
, vb
->v4l2_planes
);
1130 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1132 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1134 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1135 struct vb2_queue
*q
= vb
->vb2_queue
;
1139 int write
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1141 /* Verify and copy relevant information provided by the userspace */
1142 __fill_vb2_buffer(vb
, b
, planes
);
1144 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1145 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1147 if (IS_ERR_OR_NULL(dbuf
)) {
1148 dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
1154 /* use DMABUF size if length is not provided */
1155 if (planes
[plane
].length
== 0)
1156 planes
[plane
].length
= dbuf
->size
;
1158 if (planes
[plane
].length
< planes
[plane
].data_offset
+
1159 q
->plane_sizes
[plane
]) {
1160 dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
1166 /* Skip the plane if already verified */
1167 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1168 vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
) {
1173 dprintk(1, "qbuf: buffer for plane %d changed\n", plane
);
1175 /* Release previously acquired memory if present */
1176 __vb2_plane_dmabuf_put(q
, &vb
->planes
[plane
]);
1177 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1179 /* Acquire each plane's memory */
1180 mem_priv
= call_memop(q
, attach_dmabuf
, q
->alloc_ctx
[plane
],
1181 dbuf
, planes
[plane
].length
, write
);
1182 if (IS_ERR(mem_priv
)) {
1183 dprintk(1, "qbuf: failed to attach dmabuf\n");
1184 ret
= PTR_ERR(mem_priv
);
1189 vb
->planes
[plane
].dbuf
= dbuf
;
1190 vb
->planes
[plane
].mem_priv
= mem_priv
;
1193 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1194 * really we want to do this just before the DMA, not while queueing
1197 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1198 ret
= call_memop(q
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1200 dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
1204 vb
->planes
[plane
].dbuf_mapped
= 1;
1208 * Call driver-specific initialization on the newly acquired buffer,
1211 ret
= call_qop(q
, buf_init
, vb
);
1213 dprintk(1, "qbuf: buffer initialization failed\n");
1218 * Now that everything is in order, copy relevant information
1219 * provided by userspace.
1221 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1222 vb
->v4l2_planes
[plane
] = planes
[plane
];
1226 /* In case of errors, release planes that were already acquired */
1227 __vb2_buf_dmabuf_put(vb
);
1233 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1235 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1237 struct vb2_queue
*q
= vb
->vb2_queue
;
1240 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1241 atomic_inc(&q
->queued_count
);
1244 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1245 call_memop(q
, prepare
, vb
->planes
[plane
].mem_priv
);
1247 q
->ops
->buf_queue(vb
);
1250 static int __buf_prepare(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1252 struct vb2_queue
*q
= vb
->vb2_queue
;
1253 struct rw_semaphore
*mmap_sem
;
1256 ret
= __verify_length(vb
, b
);
1258 dprintk(1, "%s(): plane parameters verification failed: %d\n",
1263 vb
->state
= VB2_BUF_STATE_PREPARING
;
1264 switch (q
->memory
) {
1265 case V4L2_MEMORY_MMAP
:
1266 ret
= __qbuf_mmap(vb
, b
);
1268 case V4L2_MEMORY_USERPTR
:
1270 * In case of user pointer buffers vb2 allocators need to get
1271 * direct access to userspace pages. This requires getting
1272 * the mmap semaphore for read access in the current process
1273 * structure. The same semaphore is taken before calling mmap
1274 * operation, while both qbuf/prepare_buf and mmap are called
1275 * by the driver or v4l2 core with the driver's lock held.
1276 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1277 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1278 * the videobuf2 core releases the driver's lock, takes
1279 * mmap_sem and then takes the driver's lock again.
1281 mmap_sem
= ¤t
->mm
->mmap_sem
;
1282 call_qop(q
, wait_prepare
, q
);
1283 down_read(mmap_sem
);
1284 call_qop(q
, wait_finish
, q
);
1286 ret
= __qbuf_userptr(vb
, b
);
1290 case V4L2_MEMORY_DMABUF
:
1291 ret
= __qbuf_dmabuf(vb
, b
);
1294 WARN(1, "Invalid queue type\n");
1299 ret
= call_qop(q
, buf_prepare
, vb
);
1301 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret
);
1302 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1307 static int vb2_queue_or_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
,
1310 if (b
->type
!= q
->type
) {
1311 dprintk(1, "%s(): invalid buffer type\n", opname
);
1315 if (b
->index
>= q
->num_buffers
) {
1316 dprintk(1, "%s(): buffer index out of range\n", opname
);
1320 if (q
->bufs
[b
->index
] == NULL
) {
1321 /* Should never happen */
1322 dprintk(1, "%s(): buffer is NULL\n", opname
);
1326 if (b
->memory
!= q
->memory
) {
1327 dprintk(1, "%s(): invalid memory type\n", opname
);
1331 return __verify_planes_array(q
->bufs
[b
->index
], b
);
1335 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1336 * @q: videobuf2 queue
1337 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1340 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1342 * 1) verifies the passed buffer,
1343 * 2) calls buf_prepare callback in the driver (if provided), in which
1344 * driver-specific buffer initialization can be performed,
1346 * The return values from this function are intended to be directly returned
1347 * from vidioc_prepare_buf handler in driver.
1349 int vb2_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1351 struct vb2_buffer
*vb
;
1355 dprintk(1, "%s(): file io in progress\n", __func__
);
1359 ret
= vb2_queue_or_prepare_buf(q
, b
, "prepare_buf");
1363 vb
= q
->bufs
[b
->index
];
1364 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1365 dprintk(1, "%s(): invalid buffer state %d\n", __func__
,
1370 ret
= __buf_prepare(vb
, b
);
1372 /* Fill buffer information for the userspace */
1373 __fill_v4l2_buffer(vb
, b
);
1375 dprintk(1, "%s() of buffer %d succeeded\n", __func__
, vb
->v4l2_buf
.index
);
1379 EXPORT_SYMBOL_GPL(vb2_prepare_buf
);
1382 * vb2_start_streaming() - Attempt to start streaming.
1383 * @q: videobuf2 queue
1385 * If there are not enough buffers, then retry_start_streaming is set to
1386 * 1 and 0 is returned. The next time a buffer is queued and
1387 * retry_start_streaming is 1, this function will be called again to
1388 * retry starting the DMA engine.
1390 static int vb2_start_streaming(struct vb2_queue
*q
)
1394 /* Tell the driver to start streaming */
1395 ret
= call_qop(q
, start_streaming
, q
, atomic_read(&q
->queued_count
));
1398 * If there are not enough buffers queued to start streaming, then
1399 * the start_streaming operation will return -ENOBUFS and you have to
1400 * retry when the next buffer is queued.
1402 if (ret
== -ENOBUFS
) {
1403 dprintk(1, "qbuf: not enough buffers, retry when more buffers are queued.\n");
1404 q
->retry_start_streaming
= 1;
1408 dprintk(1, "qbuf: driver refused to start streaming\n");
1410 q
->retry_start_streaming
= 0;
1414 static int vb2_internal_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1416 int ret
= vb2_queue_or_prepare_buf(q
, b
, "qbuf");
1417 struct vb2_buffer
*vb
;
1422 vb
= q
->bufs
[b
->index
];
1423 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1424 dprintk(1, "%s(): invalid buffer state %d\n", __func__
,
1429 switch (vb
->state
) {
1430 case VB2_BUF_STATE_DEQUEUED
:
1431 ret
= __buf_prepare(vb
, b
);
1435 case VB2_BUF_STATE_PREPARED
:
1437 case VB2_BUF_STATE_PREPARING
:
1438 dprintk(1, "qbuf: buffer still being prepared\n");
1441 dprintk(1, "qbuf: buffer already in use\n");
1446 * Add to the queued buffers list, a buffer will stay on it until
1447 * dequeued in dqbuf.
1449 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1450 vb
->state
= VB2_BUF_STATE_QUEUED
;
1453 * If already streaming, give the buffer to driver for processing.
1454 * If not, the buffer will be given to driver on next streamon.
1457 __enqueue_in_driver(vb
);
1459 /* Fill buffer information for the userspace */
1460 __fill_v4l2_buffer(vb
, b
);
1462 if (q
->retry_start_streaming
) {
1463 ret
= vb2_start_streaming(q
);
1468 dprintk(1, "%s() of buffer %d succeeded\n", __func__
, vb
->v4l2_buf
.index
);
1473 * vb2_qbuf() - Queue a buffer from userspace
1474 * @q: videobuf2 queue
1475 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1478 * Should be called from vidioc_qbuf ioctl handler of a driver.
1480 * 1) verifies the passed buffer,
1481 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1482 * which driver-specific buffer initialization can be performed,
1483 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1484 * callback for processing.
1486 * The return values from this function are intended to be directly returned
1487 * from vidioc_qbuf handler in driver.
1489 int vb2_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1492 dprintk(1, "%s(): file io in progress\n", __func__
);
1496 return vb2_internal_qbuf(q
, b
);
1498 EXPORT_SYMBOL_GPL(vb2_qbuf
);
1501 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1504 * Will sleep if required for nonblocking == false.
1506 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1509 * All operations on vb_done_list are performed under done_lock
1510 * spinlock protection. However, buffers may be removed from
1511 * it and returned to userspace only while holding both driver's
1512 * lock and the done_lock spinlock. Thus we can be sure that as
1513 * long as we hold the driver's lock, the list will remain not
1514 * empty if list_empty() check succeeds.
1520 if (!q
->streaming
) {
1521 dprintk(1, "Streaming off, will not wait for buffers\n");
1525 if (!list_empty(&q
->done_list
)) {
1527 * Found a buffer that we were waiting for.
1533 dprintk(1, "Nonblocking and no buffers to dequeue, "
1539 * We are streaming and blocking, wait for another buffer to
1540 * become ready or for streamoff. Driver's lock is released to
1541 * allow streamoff or qbuf to be called while waiting.
1543 call_qop(q
, wait_prepare
, q
);
1546 * All locks have been released, it is safe to sleep now.
1548 dprintk(3, "Will sleep waiting for buffers\n");
1549 ret
= wait_event_interruptible(q
->done_wq
,
1550 !list_empty(&q
->done_list
) || !q
->streaming
);
1553 * We need to reevaluate both conditions again after reacquiring
1554 * the locks or return an error if one occurred.
1556 call_qop(q
, wait_finish
, q
);
1558 dprintk(1, "Sleep was interrupted\n");
1566 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1568 * Will sleep if required for nonblocking == false.
1570 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1571 struct v4l2_buffer
*b
, int nonblocking
)
1573 unsigned long flags
;
1577 * Wait for at least one buffer to become available on the done_list.
1579 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
1584 * Driver's lock has been held since we last verified that done_list
1585 * is not empty, so no need for another list_empty(done_list) check.
1587 spin_lock_irqsave(&q
->done_lock
, flags
);
1588 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
1590 * Only remove the buffer from done_list if v4l2_buffer can handle all
1593 ret
= __verify_planes_array(*vb
, b
);
1595 list_del(&(*vb
)->done_entry
);
1596 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1602 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1603 * @q: videobuf2 queue
1605 * This function will wait until all buffers that have been given to the driver
1606 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1607 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1608 * taken, for example from stop_streaming() callback.
1610 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
1612 if (!q
->streaming
) {
1613 dprintk(1, "Streaming off, will not wait for buffers\n");
1617 if (!q
->retry_start_streaming
)
1618 wait_event(q
->done_wq
, !atomic_read(&q
->queued_count
));
1621 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
1624 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1626 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
1628 struct vb2_queue
*q
= vb
->vb2_queue
;
1631 /* nothing to do if the buffer is already dequeued */
1632 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
1635 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1637 /* unmap DMABUF buffer */
1638 if (q
->memory
== V4L2_MEMORY_DMABUF
)
1639 for (i
= 0; i
< vb
->num_planes
; ++i
) {
1640 if (!vb
->planes
[i
].dbuf_mapped
)
1642 call_memop(q
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
1643 vb
->planes
[i
].dbuf_mapped
= 0;
1647 static int vb2_internal_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
1649 struct vb2_buffer
*vb
= NULL
;
1652 if (b
->type
!= q
->type
) {
1653 dprintk(1, "dqbuf: invalid buffer type\n");
1656 ret
= __vb2_get_done_vb(q
, &vb
, b
, nonblocking
);
1660 ret
= call_qop(q
, buf_finish
, vb
);
1662 dprintk(1, "dqbuf: buffer finish failed\n");
1666 switch (vb
->state
) {
1667 case VB2_BUF_STATE_DONE
:
1668 dprintk(3, "dqbuf: Returning done buffer\n");
1670 case VB2_BUF_STATE_ERROR
:
1671 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1674 dprintk(1, "dqbuf: Invalid buffer state\n");
1678 /* Fill buffer information for the userspace */
1679 __fill_v4l2_buffer(vb
, b
);
1680 /* Remove from videobuf queue */
1681 list_del(&vb
->queued_entry
);
1682 /* go back to dequeued state */
1685 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1686 vb
->v4l2_buf
.index
, vb
->state
);
1692 * vb2_dqbuf() - Dequeue a buffer to the userspace
1693 * @q: videobuf2 queue
1694 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1696 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1697 * buffers ready for dequeuing are present. Normally the driver
1698 * would be passing (file->f_flags & O_NONBLOCK) here
1700 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1702 * 1) verifies the passed buffer,
1703 * 2) calls buf_finish callback in the driver (if provided), in which
1704 * driver can perform any additional operations that may be required before
1705 * returning the buffer to userspace, such as cache sync,
1706 * 3) the buffer struct members are filled with relevant information for
1709 * The return values from this function are intended to be directly returned
1710 * from vidioc_dqbuf handler in driver.
1712 int vb2_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
1715 dprintk(1, "dqbuf: file io in progress\n");
1718 return vb2_internal_dqbuf(q
, b
, nonblocking
);
1720 EXPORT_SYMBOL_GPL(vb2_dqbuf
);
1723 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1725 * Removes all queued buffers from driver's queue and all buffers queued by
1726 * userspace from videobuf's queue. Returns to state after reqbufs.
1728 static void __vb2_queue_cancel(struct vb2_queue
*q
)
1732 if (q
->retry_start_streaming
) {
1733 q
->retry_start_streaming
= 0;
1738 * Tell driver to stop all transactions and release all queued
1742 call_qop(q
, stop_streaming
, q
);
1746 * Remove all buffers from videobuf's list...
1748 INIT_LIST_HEAD(&q
->queued_list
);
1750 * ...and done list; userspace will not receive any buffers it
1751 * has not already dequeued before initiating cancel.
1753 INIT_LIST_HEAD(&q
->done_list
);
1754 atomic_set(&q
->queued_count
, 0);
1755 wake_up_all(&q
->done_wq
);
1758 * Reinitialize all buffers for next use.
1760 for (i
= 0; i
< q
->num_buffers
; ++i
)
1761 __vb2_dqbuf(q
->bufs
[i
]);
1764 static int vb2_internal_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
1766 struct vb2_buffer
*vb
;
1769 if (type
!= q
->type
) {
1770 dprintk(1, "streamon: invalid stream type\n");
1775 dprintk(3, "streamon successful: already streaming\n");
1780 * If any buffers were queued before streamon,
1781 * we can now pass them to driver for processing.
1783 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1784 __enqueue_in_driver(vb
);
1786 /* Tell driver to start streaming. */
1787 ret
= vb2_start_streaming(q
);
1789 __vb2_queue_cancel(q
);
1795 dprintk(3, "Streamon successful\n");
1800 * vb2_streamon - start streaming
1801 * @q: videobuf2 queue
1802 * @type: type argument passed from userspace to vidioc_streamon handler
1804 * Should be called from vidioc_streamon handler of a driver.
1806 * 1) verifies current state
1807 * 2) passes any previously queued buffers to the driver and starts streaming
1809 * The return values from this function are intended to be directly returned
1810 * from vidioc_streamon handler in the driver.
1812 int vb2_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
1815 dprintk(1, "streamon: file io in progress\n");
1818 return vb2_internal_streamon(q
, type
);
1820 EXPORT_SYMBOL_GPL(vb2_streamon
);
1822 static int vb2_internal_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
1824 if (type
!= q
->type
) {
1825 dprintk(1, "streamoff: invalid stream type\n");
1829 if (!q
->streaming
) {
1830 dprintk(3, "streamoff successful: not streaming\n");
1835 * Cancel will pause streaming and remove all buffers from the driver
1836 * and videobuf, effectively returning control over them to userspace.
1838 __vb2_queue_cancel(q
);
1840 dprintk(3, "Streamoff successful\n");
1845 * vb2_streamoff - stop streaming
1846 * @q: videobuf2 queue
1847 * @type: type argument passed from userspace to vidioc_streamoff handler
1849 * Should be called from vidioc_streamoff handler of a driver.
1851 * 1) verifies current state,
1852 * 2) stop streaming and dequeues any queued buffers, including those previously
1853 * passed to the driver (after waiting for the driver to finish).
1855 * This call can be used for pausing playback.
1856 * The return values from this function are intended to be directly returned
1857 * from vidioc_streamoff handler in the driver
1859 int vb2_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
1862 dprintk(1, "streamoff: file io in progress\n");
1865 return vb2_internal_streamoff(q
, type
);
1867 EXPORT_SYMBOL_GPL(vb2_streamoff
);
1870 * __find_plane_by_offset() - find plane associated with the given offset off
1872 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
1873 unsigned int *_buffer
, unsigned int *_plane
)
1875 struct vb2_buffer
*vb
;
1876 unsigned int buffer
, plane
;
1879 * Go over all buffers and their planes, comparing the given offset
1880 * with an offset assigned to each plane. If a match is found,
1881 * return its buffer and plane numbers.
1883 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
1884 vb
= q
->bufs
[buffer
];
1886 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1887 if (vb
->v4l2_planes
[plane
].m
.mem_offset
== off
) {
1899 * vb2_expbuf() - Export a buffer as a file descriptor
1900 * @q: videobuf2 queue
1901 * @eb: export buffer structure passed from userspace to vidioc_expbuf
1904 * The return values from this function are intended to be directly returned
1905 * from vidioc_expbuf handler in driver.
1907 int vb2_expbuf(struct vb2_queue
*q
, struct v4l2_exportbuffer
*eb
)
1909 struct vb2_buffer
*vb
= NULL
;
1910 struct vb2_plane
*vb_plane
;
1912 struct dma_buf
*dbuf
;
1914 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
1915 dprintk(1, "Queue is not currently set up for mmap\n");
1919 if (!q
->mem_ops
->get_dmabuf
) {
1920 dprintk(1, "Queue does not support DMA buffer exporting\n");
1924 if (eb
->flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
1925 dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
1929 if (eb
->type
!= q
->type
) {
1930 dprintk(1, "qbuf: invalid buffer type\n");
1934 if (eb
->index
>= q
->num_buffers
) {
1935 dprintk(1, "buffer index out of range\n");
1939 vb
= q
->bufs
[eb
->index
];
1941 if (eb
->plane
>= vb
->num_planes
) {
1942 dprintk(1, "buffer plane out of range\n");
1946 vb_plane
= &vb
->planes
[eb
->plane
];
1948 dbuf
= call_memop(q
, get_dmabuf
, vb_plane
->mem_priv
, eb
->flags
& O_ACCMODE
);
1949 if (IS_ERR_OR_NULL(dbuf
)) {
1950 dprintk(1, "Failed to export buffer %d, plane %d\n",
1951 eb
->index
, eb
->plane
);
1955 ret
= dma_buf_fd(dbuf
, eb
->flags
& ~O_ACCMODE
);
1957 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1958 eb
->index
, eb
->plane
, ret
);
1963 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1964 eb
->index
, eb
->plane
, ret
);
1969 EXPORT_SYMBOL_GPL(vb2_expbuf
);
1972 * vb2_mmap() - map video buffers into application address space
1973 * @q: videobuf2 queue
1974 * @vma: vma passed to the mmap file operation handler in the driver
1976 * Should be called from mmap file operation handler of a driver.
1977 * This function maps one plane of one of the available video buffers to
1978 * userspace. To map whole video memory allocated on reqbufs, this function
1979 * has to be called once per each plane per each buffer previously allocated.
1981 * When the userspace application calls mmap, it passes to it an offset returned
1982 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1983 * a "cookie", which is then used to identify the plane to be mapped.
1984 * This function finds a plane with a matching offset and a mapping is performed
1985 * by the means of a provided memory operation.
1987 * The return values from this function are intended to be directly returned
1988 * from the mmap handler in driver.
1990 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
1992 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
1993 struct vb2_buffer
*vb
;
1994 unsigned int buffer
, plane
;
1996 unsigned long length
;
1998 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
1999 dprintk(1, "Queue is not currently set up for mmap\n");
2004 * Check memory area access mode.
2006 if (!(vma
->vm_flags
& VM_SHARED
)) {
2007 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
2010 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
2011 if (!(vma
->vm_flags
& VM_WRITE
)) {
2012 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
2016 if (!(vma
->vm_flags
& VM_READ
)) {
2017 dprintk(1, "Invalid vma flags, VM_READ needed\n");
2023 * Find the plane corresponding to the offset passed by userspace.
2025 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2029 vb
= q
->bufs
[buffer
];
2032 * MMAP requires page_aligned buffers.
2033 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2034 * so, we need to do the same here.
2036 length
= PAGE_ALIGN(vb
->v4l2_planes
[plane
].length
);
2037 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2039 "MMAP invalid, as it would overflow buffer length\n");
2043 ret
= call_memop(q
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2047 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2050 EXPORT_SYMBOL_GPL(vb2_mmap
);
2053 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2056 unsigned long pgoff
,
2057 unsigned long flags
)
2059 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2060 struct vb2_buffer
*vb
;
2061 unsigned int buffer
, plane
;
2064 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2065 dprintk(1, "Queue is not currently set up for mmap\n");
2070 * Find the plane corresponding to the offset passed by userspace.
2072 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2076 vb
= q
->bufs
[buffer
];
2078 return (unsigned long)vb2_plane_vaddr(vb
, plane
);
2080 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2083 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2084 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2087 * vb2_poll() - implements poll userspace operation
2088 * @q: videobuf2 queue
2089 * @file: file argument passed to the poll file operation handler
2090 * @wait: wait argument passed to the poll file operation handler
2092 * This function implements poll file operation handler for a driver.
2093 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2094 * be informed that the file descriptor of a video device is available for
2096 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2097 * will be reported as available for writing.
2099 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2102 * The return values from this function are intended to be directly returned
2103 * from poll handler in driver.
2105 unsigned int vb2_poll(struct vb2_queue
*q
, struct file
*file
, poll_table
*wait
)
2107 struct video_device
*vfd
= video_devdata(file
);
2108 unsigned long req_events
= poll_requested_events(wait
);
2109 struct vb2_buffer
*vb
= NULL
;
2110 unsigned int res
= 0;
2111 unsigned long flags
;
2113 if (test_bit(V4L2_FL_USES_V4L2_FH
, &vfd
->flags
)) {
2114 struct v4l2_fh
*fh
= file
->private_data
;
2116 if (v4l2_event_pending(fh
))
2118 else if (req_events
& POLLPRI
)
2119 poll_wait(file
, &fh
->wait
, wait
);
2122 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLIN
| POLLRDNORM
)))
2124 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLOUT
| POLLWRNORM
)))
2128 * Start file I/O emulator only if streaming API has not been used yet.
2130 if (q
->num_buffers
== 0 && q
->fileio
== NULL
) {
2131 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2132 (req_events
& (POLLIN
| POLLRDNORM
))) {
2133 if (__vb2_init_fileio(q
, 1))
2134 return res
| POLLERR
;
2136 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2137 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2138 if (__vb2_init_fileio(q
, 0))
2139 return res
| POLLERR
;
2141 * Write to OUTPUT queue can be done immediately.
2143 return res
| POLLOUT
| POLLWRNORM
;
2148 * There is nothing to wait for if no buffers have already been queued.
2150 if (list_empty(&q
->queued_list
))
2151 return res
| POLLERR
;
2153 if (list_empty(&q
->done_list
))
2154 poll_wait(file
, &q
->done_wq
, wait
);
2157 * Take first buffer available for dequeuing.
2159 spin_lock_irqsave(&q
->done_lock
, flags
);
2160 if (!list_empty(&q
->done_list
))
2161 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2163 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2165 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2166 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2167 return (V4L2_TYPE_IS_OUTPUT(q
->type
)) ?
2168 res
| POLLOUT
| POLLWRNORM
:
2169 res
| POLLIN
| POLLRDNORM
;
2173 EXPORT_SYMBOL_GPL(vb2_poll
);
2176 * vb2_queue_init() - initialize a videobuf2 queue
2177 * @q: videobuf2 queue; this structure should be allocated in driver
2179 * The vb2_queue structure should be allocated by the driver. The driver is
2180 * responsible of clearing it's content and setting initial values for some
2181 * required entries before calling this function.
2182 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2183 * to the struct vb2_queue description in include/media/videobuf2-core.h
2184 * for more information.
2186 int vb2_queue_init(struct vb2_queue
*q
)
2193 WARN_ON(!q
->mem_ops
) ||
2194 WARN_ON(!q
->type
) ||
2195 WARN_ON(!q
->io_modes
) ||
2196 WARN_ON(!q
->ops
->queue_setup
) ||
2197 WARN_ON(!q
->ops
->buf_queue
) ||
2198 WARN_ON(q
->timestamp_type
& ~V4L2_BUF_FLAG_TIMESTAMP_MASK
))
2201 /* Warn that the driver should choose an appropriate timestamp type */
2202 WARN_ON(q
->timestamp_type
== V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN
);
2204 INIT_LIST_HEAD(&q
->queued_list
);
2205 INIT_LIST_HEAD(&q
->done_list
);
2206 spin_lock_init(&q
->done_lock
);
2207 init_waitqueue_head(&q
->done_wq
);
2209 if (q
->buf_struct_size
== 0)
2210 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2214 EXPORT_SYMBOL_GPL(vb2_queue_init
);
2217 * vb2_queue_release() - stop streaming, release the queue and free memory
2218 * @q: videobuf2 queue
2220 * This function stops streaming and performs necessary clean ups, including
2221 * freeing video buffer memory. The driver is responsible for freeing
2222 * the vb2_queue structure itself.
2224 void vb2_queue_release(struct vb2_queue
*q
)
2226 __vb2_cleanup_fileio(q
);
2227 __vb2_queue_cancel(q
);
2228 __vb2_queue_free(q
, q
->num_buffers
);
2230 EXPORT_SYMBOL_GPL(vb2_queue_release
);
2233 * struct vb2_fileio_buf - buffer context used by file io emulator
2235 * vb2 provides a compatibility layer and emulator of file io (read and
2236 * write) calls on top of streaming API. This structure is used for
2237 * tracking context related to the buffers.
2239 struct vb2_fileio_buf
{
2243 unsigned int queued
:1;
2247 * struct vb2_fileio_data - queue context used by file io emulator
2249 * vb2 provides a compatibility layer and emulator of file io (read and
2250 * write) calls on top of streaming API. For proper operation it required
2251 * this structure to save the driver state between each call of the read
2252 * or write function.
2254 struct vb2_fileio_data
{
2255 struct v4l2_requestbuffers req
;
2256 struct v4l2_buffer b
;
2257 struct vb2_fileio_buf bufs
[VIDEO_MAX_FRAME
];
2259 unsigned int q_count
;
2260 unsigned int dq_count
;
2265 * __vb2_init_fileio() - initialize file io emulator
2266 * @q: videobuf2 queue
2267 * @read: mode selector (1 means read, 0 means write)
2269 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2271 struct vb2_fileio_data
*fileio
;
2273 unsigned int count
= 0;
2278 if ((read
&& !(q
->io_modes
& VB2_READ
)) ||
2279 (!read
&& !(q
->io_modes
& VB2_WRITE
)))
2283 * Check if device supports mapping buffers to kernel virtual space.
2285 if (!q
->mem_ops
->vaddr
)
2289 * Check if streaming api has not been already activated.
2291 if (q
->streaming
|| q
->num_buffers
> 0)
2295 * Start with count 1, driver can increase it in queue_setup()
2299 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2300 (read
) ? "read" : "write", count
, q
->io_flags
);
2302 fileio
= kzalloc(sizeof(struct vb2_fileio_data
), GFP_KERNEL
);
2306 fileio
->flags
= q
->io_flags
;
2309 * Request buffers and use MMAP type to force driver
2310 * to allocate buffers by itself.
2312 fileio
->req
.count
= count
;
2313 fileio
->req
.memory
= V4L2_MEMORY_MMAP
;
2314 fileio
->req
.type
= q
->type
;
2315 ret
= vb2_reqbufs(q
, &fileio
->req
);
2320 * Check if plane_count is correct
2321 * (multiplane buffers are not supported).
2323 if (q
->bufs
[0]->num_planes
!= 1) {
2329 * Get kernel address of each buffer.
2331 for (i
= 0; i
< q
->num_buffers
; i
++) {
2332 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2333 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2337 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2341 * Read mode requires pre queuing of all buffers.
2345 * Queue all buffers.
2347 for (i
= 0; i
< q
->num_buffers
; i
++) {
2348 struct v4l2_buffer
*b
= &fileio
->b
;
2349 memset(b
, 0, sizeof(*b
));
2351 b
->memory
= q
->memory
;
2353 ret
= vb2_qbuf(q
, b
);
2356 fileio
->bufs
[i
].queued
= 1;
2358 fileio
->index
= q
->num_buffers
;
2364 ret
= vb2_streamon(q
, q
->type
);
2373 fileio
->req
.count
= 0;
2374 vb2_reqbufs(q
, &fileio
->req
);
2382 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2383 * @q: videobuf2 queue
2385 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2387 struct vb2_fileio_data
*fileio
= q
->fileio
;
2390 vb2_internal_streamoff(q
, q
->type
);
2392 fileio
->req
.count
= 0;
2393 vb2_reqbufs(q
, &fileio
->req
);
2395 dprintk(3, "file io emulator closed\n");
2401 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2402 * @q: videobuf2 queue
2403 * @data: pointed to target userspace buffer
2404 * @count: number of bytes to read or write
2405 * @ppos: file handle position tracking pointer
2406 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2407 * @read: access mode selector (1 means read, 0 means write)
2409 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2410 loff_t
*ppos
, int nonblock
, int read
)
2412 struct vb2_fileio_data
*fileio
;
2413 struct vb2_fileio_buf
*buf
;
2416 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
2417 read
? "read" : "write", (long)*ppos
, count
,
2418 nonblock
? "non" : "");
2424 * Initialize emulator on first call.
2427 ret
= __vb2_init_fileio(q
, read
);
2428 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
2435 * Check if we need to dequeue the buffer.
2437 index
= fileio
->index
;
2438 if (index
>= q
->num_buffers
) {
2440 * Call vb2_dqbuf to get buffer back.
2442 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
2443 fileio
->b
.type
= q
->type
;
2444 fileio
->b
.memory
= q
->memory
;
2445 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, nonblock
);
2446 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
2449 fileio
->dq_count
+= 1;
2451 index
= fileio
->b
.index
;
2452 buf
= &fileio
->bufs
[index
];
2455 * Get number of bytes filled by the driver
2459 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
2460 : vb2_plane_size(q
->bufs
[index
], 0);
2462 buf
= &fileio
->bufs
[index
];
2466 * Limit count on last few bytes of the buffer.
2468 if (buf
->pos
+ count
> buf
->size
) {
2469 count
= buf
->size
- buf
->pos
;
2470 dprintk(5, "reducing read count: %zd\n", count
);
2474 * Transfer data to userspace.
2476 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
2477 count
, index
, buf
->pos
);
2479 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
2481 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
2483 dprintk(3, "file io: error copying data\n");
2494 * Queue next buffer if required.
2496 if (buf
->pos
== buf
->size
||
2497 (!read
&& (fileio
->flags
& VB2_FILEIO_WRITE_IMMEDIATELY
))) {
2499 * Check if this is the last buffer to read.
2501 if (read
&& (fileio
->flags
& VB2_FILEIO_READ_ONCE
) &&
2502 fileio
->dq_count
== 1) {
2503 dprintk(3, "file io: read limit reached\n");
2504 return __vb2_cleanup_fileio(q
);
2508 * Call vb2_qbuf and give buffer to the driver.
2510 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
2511 fileio
->b
.type
= q
->type
;
2512 fileio
->b
.memory
= q
->memory
;
2513 fileio
->b
.index
= index
;
2514 fileio
->b
.bytesused
= buf
->pos
;
2515 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
2516 dprintk(5, "file io: vb2_dbuf result: %d\n", ret
);
2521 * Buffer has been queued, update the status
2525 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
2526 fileio
->q_count
+= 1;
2527 if (fileio
->index
< q
->num_buffers
)
2532 * Return proper number of bytes processed.
2539 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2540 loff_t
*ppos
, int nonblocking
)
2542 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
2544 EXPORT_SYMBOL_GPL(vb2_read
);
2546 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
2547 loff_t
*ppos
, int nonblocking
)
2549 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
2550 ppos
, nonblocking
, 0);
2552 EXPORT_SYMBOL_GPL(vb2_write
);
2556 * The following functions are not part of the vb2 core API, but are helper
2557 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2558 * and struct vb2_ops.
2559 * They contain boilerplate code that most if not all drivers have to do
2560 * and so they simplify the driver code.
2563 /* The queue is busy if there is a owner and you are not that owner. */
2564 static inline bool vb2_queue_is_busy(struct video_device
*vdev
, struct file
*file
)
2566 return vdev
->queue
->owner
&& vdev
->queue
->owner
!= file
->private_data
;
2569 /* vb2 ioctl helpers */
2571 int vb2_ioctl_reqbufs(struct file
*file
, void *priv
,
2572 struct v4l2_requestbuffers
*p
)
2574 struct video_device
*vdev
= video_devdata(file
);
2575 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->type
);
2579 if (vb2_queue_is_busy(vdev
, file
))
2581 res
= __reqbufs(vdev
->queue
, p
);
2582 /* If count == 0, then the owner has released all buffers and he
2583 is no longer owner of the queue. Otherwise we have a new owner. */
2585 vdev
->queue
->owner
= p
->count
? file
->private_data
: NULL
;
2588 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs
);
2590 int vb2_ioctl_create_bufs(struct file
*file
, void *priv
,
2591 struct v4l2_create_buffers
*p
)
2593 struct video_device
*vdev
= video_devdata(file
);
2594 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->format
.type
);
2596 p
->index
= vdev
->queue
->num_buffers
;
2597 /* If count == 0, then just check if memory and type are valid.
2598 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
2600 return res
!= -EBUSY
? res
: 0;
2603 if (vb2_queue_is_busy(vdev
, file
))
2605 res
= __create_bufs(vdev
->queue
, p
);
2607 vdev
->queue
->owner
= file
->private_data
;
2610 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs
);
2612 int vb2_ioctl_prepare_buf(struct file
*file
, void *priv
,
2613 struct v4l2_buffer
*p
)
2615 struct video_device
*vdev
= video_devdata(file
);
2617 if (vb2_queue_is_busy(vdev
, file
))
2619 return vb2_prepare_buf(vdev
->queue
, p
);
2621 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf
);
2623 int vb2_ioctl_querybuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
2625 struct video_device
*vdev
= video_devdata(file
);
2627 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
2628 return vb2_querybuf(vdev
->queue
, p
);
2630 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf
);
2632 int vb2_ioctl_qbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
2634 struct video_device
*vdev
= video_devdata(file
);
2636 if (vb2_queue_is_busy(vdev
, file
))
2638 return vb2_qbuf(vdev
->queue
, p
);
2640 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf
);
2642 int vb2_ioctl_dqbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
2644 struct video_device
*vdev
= video_devdata(file
);
2646 if (vb2_queue_is_busy(vdev
, file
))
2648 return vb2_dqbuf(vdev
->queue
, p
, file
->f_flags
& O_NONBLOCK
);
2650 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf
);
2652 int vb2_ioctl_streamon(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
2654 struct video_device
*vdev
= video_devdata(file
);
2656 if (vb2_queue_is_busy(vdev
, file
))
2658 return vb2_streamon(vdev
->queue
, i
);
2660 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon
);
2662 int vb2_ioctl_streamoff(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
2664 struct video_device
*vdev
= video_devdata(file
);
2666 if (vb2_queue_is_busy(vdev
, file
))
2668 return vb2_streamoff(vdev
->queue
, i
);
2670 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff
);
2672 int vb2_ioctl_expbuf(struct file
*file
, void *priv
, struct v4l2_exportbuffer
*p
)
2674 struct video_device
*vdev
= video_devdata(file
);
2676 if (vb2_queue_is_busy(vdev
, file
))
2678 return vb2_expbuf(vdev
->queue
, p
);
2680 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf
);
2682 /* v4l2_file_operations helpers */
2684 int vb2_fop_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2686 struct video_device
*vdev
= video_devdata(file
);
2687 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
2690 if (lock
&& mutex_lock_interruptible(lock
))
2691 return -ERESTARTSYS
;
2692 err
= vb2_mmap(vdev
->queue
, vma
);
2697 EXPORT_SYMBOL_GPL(vb2_fop_mmap
);
2699 int _vb2_fop_release(struct file
*file
, struct mutex
*lock
)
2701 struct video_device
*vdev
= video_devdata(file
);
2703 if (file
->private_data
== vdev
->queue
->owner
) {
2706 vb2_queue_release(vdev
->queue
);
2707 vdev
->queue
->owner
= NULL
;
2711 return v4l2_fh_release(file
);
2713 EXPORT_SYMBOL_GPL(_vb2_fop_release
);
2715 int vb2_fop_release(struct file
*file
)
2717 struct video_device
*vdev
= video_devdata(file
);
2718 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
2720 return _vb2_fop_release(file
, lock
);
2722 EXPORT_SYMBOL_GPL(vb2_fop_release
);
2724 ssize_t
vb2_fop_write(struct file
*file
, const char __user
*buf
,
2725 size_t count
, loff_t
*ppos
)
2727 struct video_device
*vdev
= video_devdata(file
);
2728 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
2731 if (lock
&& mutex_lock_interruptible(lock
))
2732 return -ERESTARTSYS
;
2733 if (vb2_queue_is_busy(vdev
, file
))
2735 err
= vb2_write(vdev
->queue
, buf
, count
, ppos
,
2736 file
->f_flags
& O_NONBLOCK
);
2737 if (vdev
->queue
->fileio
)
2738 vdev
->queue
->owner
= file
->private_data
;
2744 EXPORT_SYMBOL_GPL(vb2_fop_write
);
2746 ssize_t
vb2_fop_read(struct file
*file
, char __user
*buf
,
2747 size_t count
, loff_t
*ppos
)
2749 struct video_device
*vdev
= video_devdata(file
);
2750 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
2753 if (lock
&& mutex_lock_interruptible(lock
))
2754 return -ERESTARTSYS
;
2755 if (vb2_queue_is_busy(vdev
, file
))
2757 err
= vb2_read(vdev
->queue
, buf
, count
, ppos
,
2758 file
->f_flags
& O_NONBLOCK
);
2759 if (vdev
->queue
->fileio
)
2760 vdev
->queue
->owner
= file
->private_data
;
2766 EXPORT_SYMBOL_GPL(vb2_fop_read
);
2768 unsigned int vb2_fop_poll(struct file
*file
, poll_table
*wait
)
2770 struct video_device
*vdev
= video_devdata(file
);
2771 struct vb2_queue
*q
= vdev
->queue
;
2772 struct mutex
*lock
= q
->lock
? q
->lock
: vdev
->lock
;
2773 unsigned long req_events
= poll_requested_events(wait
);
2776 bool must_lock
= false;
2778 /* Try to be smart: only lock if polling might start fileio,
2779 otherwise locking will only introduce unwanted delays. */
2780 if (q
->num_buffers
== 0 && q
->fileio
== NULL
) {
2781 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2782 (req_events
& (POLLIN
| POLLRDNORM
)))
2784 else if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2785 (req_events
& (POLLOUT
| POLLWRNORM
)))
2789 /* If locking is needed, but this helper doesn't know how, then you
2790 shouldn't be using this helper but you should write your own. */
2791 WARN_ON(must_lock
&& !lock
);
2793 if (must_lock
&& lock
&& mutex_lock_interruptible(lock
))
2798 res
= vb2_poll(vdev
->queue
, file
, wait
);
2800 /* If fileio was started, then we have a new queue owner. */
2801 if (must_lock
&& !fileio
&& q
->fileio
)
2802 q
->owner
= file
->private_data
;
2803 if (must_lock
&& lock
)
2807 EXPORT_SYMBOL_GPL(vb2_fop_poll
);
2810 unsigned long vb2_fop_get_unmapped_area(struct file
*file
, unsigned long addr
,
2811 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
2813 struct video_device
*vdev
= video_devdata(file
);
2814 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
2817 if (lock
&& mutex_lock_interruptible(lock
))
2818 return -ERESTARTSYS
;
2819 ret
= vb2_get_unmapped_area(vdev
->queue
, addr
, len
, pgoff
, flags
);
2824 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area
);
2827 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
2829 void vb2_ops_wait_prepare(struct vb2_queue
*vq
)
2831 mutex_unlock(vq
->lock
);
2833 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare
);
2835 void vb2_ops_wait_finish(struct vb2_queue
*vq
)
2837 mutex_lock(vq
->lock
);
2839 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish
);
2841 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
2842 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2843 MODULE_LICENSE("GPL");