2 * videobuf2-core.c - V4L2 driver helper framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
33 #include <trace/events/v4l2.h>
36 module_param(debug
, int, 0644);
38 #define dprintk(level, fmt, arg...) \
41 pr_info("vb2: %s: " fmt, __func__, ## arg); \
44 #ifdef CONFIG_VIDEO_ADV_DEBUG
47 * If advanced debugging is on, then count how often each op is called
48 * successfully, which can either be per-buffer or per-queue.
50 * This makes it easy to check that the 'init' and 'cleanup'
51 * (and variations thereof) stay balanced.
54 #define log_memop(vb, op) \
55 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
56 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
57 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
59 #define call_memop(vb, op, args...) \
61 struct vb2_queue *_q = (vb)->vb2_queue; \
65 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
67 (vb)->cnt_mem_ ## op++; \
71 #define call_ptr_memop(vb, op, args...) \
73 struct vb2_queue *_q = (vb)->vb2_queue; \
77 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
78 if (!IS_ERR_OR_NULL(ptr)) \
79 (vb)->cnt_mem_ ## op++; \
83 #define call_void_memop(vb, op, args...) \
85 struct vb2_queue *_q = (vb)->vb2_queue; \
88 if (_q->mem_ops->op) \
89 _q->mem_ops->op(args); \
90 (vb)->cnt_mem_ ## op++; \
93 #define log_qop(q, op) \
94 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
95 (q)->ops->op ? "" : " (nop)")
97 #define call_qop(q, op, args...) \
102 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
108 #define call_void_qop(q, op, args...) \
112 (q)->ops->op(args); \
116 #define log_vb_qop(vb, op, args...) \
117 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
118 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
119 (vb)->vb2_queue->ops->op ? "" : " (nop)")
121 #define call_vb_qop(vb, op, args...) \
125 log_vb_qop(vb, op); \
126 err = (vb)->vb2_queue->ops->op ? \
127 (vb)->vb2_queue->ops->op(args) : 0; \
129 (vb)->cnt_ ## op++; \
133 #define call_void_vb_qop(vb, op, args...) \
135 log_vb_qop(vb, op); \
136 if ((vb)->vb2_queue->ops->op) \
137 (vb)->vb2_queue->ops->op(args); \
138 (vb)->cnt_ ## op++; \
143 #define call_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : 0)
147 #define call_ptr_memop(vb, op, args...) \
148 ((vb)->vb2_queue->mem_ops->op ? \
149 (vb)->vb2_queue->mem_ops->op(args) : NULL)
151 #define call_void_memop(vb, op, args...) \
153 if ((vb)->vb2_queue->mem_ops->op) \
154 (vb)->vb2_queue->mem_ops->op(args); \
157 #define call_qop(q, op, args...) \
158 ((q)->ops->op ? (q)->ops->op(args) : 0)
160 #define call_void_qop(q, op, args...) \
163 (q)->ops->op(args); \
166 #define call_vb_qop(vb, op, args...) \
167 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
169 #define call_void_vb_qop(vb, op, args...) \
171 if ((vb)->vb2_queue->ops->op) \
172 (vb)->vb2_queue->ops->op(args); \
177 /* Flags that are set by the vb2 core */
178 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
179 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
180 V4L2_BUF_FLAG_PREPARED | \
181 V4L2_BUF_FLAG_TIMESTAMP_MASK)
182 /* Output buffer flags that should be passed on to the driver */
183 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
184 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
186 static void __vb2_queue_cancel(struct vb2_queue
*q
);
187 static void __enqueue_in_driver(struct vb2_buffer
*vb
);
190 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
192 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
194 struct vb2_queue
*q
= vb
->vb2_queue
;
195 enum dma_data_direction dma_dir
=
196 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
201 * Allocate memory for all planes in this buffer
202 * NOTE: mmapped areas should be page aligned
204 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
205 unsigned long size
= PAGE_ALIGN(q
->plane_sizes
[plane
]);
207 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
208 size
, dma_dir
, q
->gfp_flags
);
209 if (IS_ERR_OR_NULL(mem_priv
))
212 /* Associate allocator private data with this plane */
213 vb
->planes
[plane
].mem_priv
= mem_priv
;
214 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
219 /* Free already allocated memory if one of the allocations failed */
220 for (; plane
> 0; --plane
) {
221 call_void_memop(vb
, put
, vb
->planes
[plane
- 1].mem_priv
);
222 vb
->planes
[plane
- 1].mem_priv
= NULL
;
229 * __vb2_buf_mem_free() - free memory of the given buffer
231 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
235 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
236 call_void_memop(vb
, put
, vb
->planes
[plane
].mem_priv
);
237 vb
->planes
[plane
].mem_priv
= NULL
;
238 dprintk(3, "freed plane %d of buffer %d\n", plane
,
244 * __vb2_buf_userptr_put() - release userspace memory associated with
247 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
251 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
252 if (vb
->planes
[plane
].mem_priv
)
253 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
254 vb
->planes
[plane
].mem_priv
= NULL
;
259 * __vb2_plane_dmabuf_put() - release memory associated with
260 * a DMABUF shared plane
262 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
268 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
270 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
271 dma_buf_put(p
->dbuf
);
272 memset(p
, 0, sizeof(*p
));
276 * __vb2_buf_dmabuf_put() - release memory associated with
277 * a DMABUF shared buffer
279 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
283 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
284 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
288 * __setup_lengths() - setup initial lengths for every plane in
289 * every buffer on the queue
291 static void __setup_lengths(struct vb2_queue
*q
, unsigned int n
)
293 unsigned int buffer
, plane
;
294 struct vb2_buffer
*vb
;
296 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
297 vb
= q
->bufs
[buffer
];
301 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
302 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
307 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
308 * every buffer on the queue
310 static void __setup_offsets(struct vb2_queue
*q
, unsigned int n
)
312 unsigned int buffer
, plane
;
313 struct vb2_buffer
*vb
;
316 if (q
->num_buffers
) {
317 struct v4l2_plane
*p
;
318 vb
= q
->bufs
[q
->num_buffers
- 1];
319 p
= &vb
->v4l2_planes
[vb
->num_planes
- 1];
320 off
= PAGE_ALIGN(p
->m
.mem_offset
+ p
->length
);
325 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
326 vb
= q
->bufs
[buffer
];
330 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
331 vb
->v4l2_planes
[plane
].m
.mem_offset
= off
;
333 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
336 off
+= vb
->v4l2_planes
[plane
].length
;
337 off
= PAGE_ALIGN(off
);
343 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
344 * video buffer memory for all buffers/planes on the queue and initializes the
347 * Returns the number of buffers successfully allocated.
349 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum v4l2_memory memory
,
350 unsigned int num_buffers
, unsigned int num_planes
)
353 struct vb2_buffer
*vb
;
356 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
357 /* Allocate videobuf buffer structures */
358 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
360 dprintk(1, "memory alloc for buffer struct failed\n");
364 /* Length stores number of planes for multiplanar buffers */
365 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
))
366 vb
->v4l2_buf
.length
= num_planes
;
368 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
370 vb
->num_planes
= num_planes
;
371 vb
->v4l2_buf
.index
= q
->num_buffers
+ buffer
;
372 vb
->v4l2_buf
.type
= q
->type
;
373 vb
->v4l2_buf
.memory
= memory
;
375 /* Allocate video buffer memory for the MMAP type */
376 if (memory
== V4L2_MEMORY_MMAP
) {
377 ret
= __vb2_buf_mem_alloc(vb
);
379 dprintk(1, "failed allocating memory for "
380 "buffer %d\n", buffer
);
385 * Call the driver-provided buffer initialization
386 * callback, if given. An error in initialization
387 * results in queue setup failure.
389 ret
= call_vb_qop(vb
, buf_init
, vb
);
391 dprintk(1, "buffer %d %p initialization"
392 " failed\n", buffer
, vb
);
393 __vb2_buf_mem_free(vb
);
399 q
->bufs
[q
->num_buffers
+ buffer
] = vb
;
402 __setup_lengths(q
, buffer
);
403 if (memory
== V4L2_MEMORY_MMAP
)
404 __setup_offsets(q
, buffer
);
406 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
413 * __vb2_free_mem() - release all video buffer memory for a given queue
415 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
418 struct vb2_buffer
*vb
;
420 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
422 vb
= q
->bufs
[buffer
];
426 /* Free MMAP buffers or release USERPTR buffers */
427 if (q
->memory
== V4L2_MEMORY_MMAP
)
428 __vb2_buf_mem_free(vb
);
429 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
430 __vb2_buf_dmabuf_put(vb
);
432 __vb2_buf_userptr_put(vb
);
437 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
438 * related information, if no buffers are left return the queue to an
439 * uninitialized state. Might be called even if the queue has already been freed.
441 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
446 * Sanity check: when preparing a buffer the queue lock is released for
447 * a short while (see __buf_prepare for the details), which would allow
448 * a race with a reqbufs which can call this function. Removing the
449 * buffers from underneath __buf_prepare is obviously a bad idea, so we
450 * check if any of the buffers is in the state PREPARING, and if so we
451 * just return -EAGAIN.
453 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
455 if (q
->bufs
[buffer
] == NULL
)
457 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
458 dprintk(1, "preparing buffers, cannot free\n");
463 /* Call driver-provided cleanup function for each buffer, if provided */
464 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
466 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
468 if (vb
&& vb
->planes
[0].mem_priv
)
469 call_void_vb_qop(vb
, buf_cleanup
, vb
);
472 /* Release video buffer memory */
473 __vb2_free_mem(q
, buffers
);
475 #ifdef CONFIG_VIDEO_ADV_DEBUG
477 * Check that all the calls were balances during the life-time of this
478 * queue. If not (or if the debug level is 1 or up), then dump the
479 * counters to the kernel log.
481 if (q
->num_buffers
) {
482 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
483 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
485 if (unbalanced
|| debug
) {
486 pr_info("vb2: counters for queue %p:%s\n", q
,
487 unbalanced
? " UNBALANCED!" : "");
488 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
489 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
490 q
->cnt_stop_streaming
);
491 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
492 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
494 q
->cnt_queue_setup
= 0;
495 q
->cnt_wait_prepare
= 0;
496 q
->cnt_wait_finish
= 0;
497 q
->cnt_start_streaming
= 0;
498 q
->cnt_stop_streaming
= 0;
500 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
501 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
502 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
503 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
504 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
505 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
506 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
507 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
508 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
509 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
511 if (unbalanced
|| debug
) {
512 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
513 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
514 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
515 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
516 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
517 pr_info("vb2: buf_queue: %u buf_done: %u\n",
518 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
519 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
520 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
521 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
523 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
524 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
525 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
526 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
527 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
528 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
529 vb
->cnt_mem_get_dmabuf
,
530 vb
->cnt_mem_num_users
,
537 /* Free videobuf buffers */
538 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
540 kfree(q
->bufs
[buffer
]);
541 q
->bufs
[buffer
] = NULL
;
544 q
->num_buffers
-= buffers
;
545 if (!q
->num_buffers
) {
547 INIT_LIST_HEAD(&q
->queued_list
);
553 * __verify_planes_array() - verify that the planes array passed in struct
554 * v4l2_buffer from userspace can be safely used
556 static int __verify_planes_array(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
558 if (!V4L2_TYPE_IS_MULTIPLANAR(b
->type
))
561 /* Is memory for copying plane information present? */
562 if (NULL
== b
->m
.planes
) {
563 dprintk(1, "multi-planar buffer passed but "
564 "planes array not provided\n");
568 if (b
->length
< vb
->num_planes
|| b
->length
> VIDEO_MAX_PLANES
) {
569 dprintk(1, "incorrect planes array length, "
570 "expected %d, got %d\n", vb
->num_planes
, b
->length
);
578 * __verify_length() - Verify that the bytesused value for each plane fits in
579 * the plane length and that the data offset doesn't exceed the bytesused value.
581 static int __verify_length(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
584 unsigned int bytesused
;
587 if (!V4L2_TYPE_IS_OUTPUT(b
->type
))
590 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
591 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
592 length
= (b
->memory
== V4L2_MEMORY_USERPTR
||
593 b
->memory
== V4L2_MEMORY_DMABUF
)
594 ? b
->m
.planes
[plane
].length
595 : vb
->v4l2_planes
[plane
].length
;
596 bytesused
= b
->m
.planes
[plane
].bytesused
597 ? b
->m
.planes
[plane
].bytesused
: length
;
599 if (b
->m
.planes
[plane
].bytesused
> length
)
602 if (b
->m
.planes
[plane
].data_offset
> 0 &&
603 b
->m
.planes
[plane
].data_offset
>= bytesused
)
607 length
= (b
->memory
== V4L2_MEMORY_USERPTR
)
608 ? b
->length
: vb
->v4l2_planes
[0].length
;
609 bytesused
= b
->bytesused
? b
->bytesused
: length
;
611 if (b
->bytesused
> length
)
619 * __buffer_in_use() - return true if the buffer is in use and
620 * the queue cannot be freed (by the means of REQBUFS(0)) call
622 static bool __buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
625 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
626 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
628 * If num_users() has not been provided, call_memop
629 * will return 0, apparently nobody cares about this
630 * case anyway. If num_users() returns more than 1,
631 * we are not the only user of the plane's memory.
633 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
640 * __buffers_in_use() - return true if any buffers on the queue are in use and
641 * the queue cannot be freed (by the means of REQBUFS(0)) call
643 static bool __buffers_in_use(struct vb2_queue
*q
)
646 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
647 if (__buffer_in_use(q
, q
->bufs
[buffer
]))
654 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
655 * returned to userspace
657 static void __fill_v4l2_buffer(struct vb2_buffer
*vb
, struct v4l2_buffer
*b
)
659 struct vb2_queue
*q
= vb
->vb2_queue
;
661 /* Copy back data such as timestamp, flags, etc. */
662 memcpy(b
, &vb
->v4l2_buf
, offsetof(struct v4l2_buffer
, m
));
663 b
->reserved2
= vb
->v4l2_buf
.reserved2
;
664 b
->reserved
= vb
->v4l2_buf
.reserved
;
666 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
)) {
668 * Fill in plane-related data if userspace provided an array
669 * for it. The caller has already verified memory and size.
671 b
->length
= vb
->num_planes
;
672 memcpy(b
->m
.planes
, vb
->v4l2_planes
,
673 b
->length
* sizeof(struct v4l2_plane
));
676 * We use length and offset in v4l2_planes array even for
677 * single-planar buffers, but userspace does not.
679 b
->length
= vb
->v4l2_planes
[0].length
;
680 b
->bytesused
= vb
->v4l2_planes
[0].bytesused
;
681 if (q
->memory
== V4L2_MEMORY_MMAP
)
682 b
->m
.offset
= vb
->v4l2_planes
[0].m
.mem_offset
;
683 else if (q
->memory
== V4L2_MEMORY_USERPTR
)
684 b
->m
.userptr
= vb
->v4l2_planes
[0].m
.userptr
;
685 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
686 b
->m
.fd
= vb
->v4l2_planes
[0].m
.fd
;
690 * Clear any buffer state related flags.
692 b
->flags
&= ~V4L2_BUFFER_MASK_FLAGS
;
693 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
;
694 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
695 V4L2_BUF_FLAG_TIMESTAMP_COPY
) {
697 * For non-COPY timestamps, drop timestamp source bits
698 * and obtain the timestamp source from the queue.
700 b
->flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
701 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
705 case VB2_BUF_STATE_QUEUED
:
706 case VB2_BUF_STATE_ACTIVE
:
707 b
->flags
|= V4L2_BUF_FLAG_QUEUED
;
709 case VB2_BUF_STATE_ERROR
:
710 b
->flags
|= V4L2_BUF_FLAG_ERROR
;
712 case VB2_BUF_STATE_DONE
:
713 b
->flags
|= V4L2_BUF_FLAG_DONE
;
715 case VB2_BUF_STATE_PREPARED
:
716 b
->flags
|= V4L2_BUF_FLAG_PREPARED
;
718 case VB2_BUF_STATE_PREPARING
:
719 case VB2_BUF_STATE_DEQUEUED
:
720 case VB2_BUF_STATE_REQUEUEING
:
725 if (__buffer_in_use(q
, vb
))
726 b
->flags
|= V4L2_BUF_FLAG_MAPPED
;
730 * vb2_querybuf() - query video buffer information
732 * @b: buffer struct passed from userspace to vidioc_querybuf handler
735 * Should be called from vidioc_querybuf ioctl handler in driver.
736 * This function will verify the passed v4l2_buffer structure and fill the
737 * relevant information for the userspace.
739 * The return values from this function are intended to be directly returned
740 * from vidioc_querybuf handler in driver.
742 int vb2_querybuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
744 struct vb2_buffer
*vb
;
747 if (b
->type
!= q
->type
) {
748 dprintk(1, "wrong buffer type\n");
752 if (b
->index
>= q
->num_buffers
) {
753 dprintk(1, "buffer index out of range\n");
756 vb
= q
->bufs
[b
->index
];
757 ret
= __verify_planes_array(vb
, b
);
759 __fill_v4l2_buffer(vb
, b
);
762 EXPORT_SYMBOL(vb2_querybuf
);
765 * __verify_userptr_ops() - verify that all memory operations required for
766 * USERPTR queue type have been provided
768 static int __verify_userptr_ops(struct vb2_queue
*q
)
770 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
771 !q
->mem_ops
->put_userptr
)
778 * __verify_mmap_ops() - verify that all memory operations required for
779 * MMAP queue type have been provided
781 static int __verify_mmap_ops(struct vb2_queue
*q
)
783 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
784 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
791 * __verify_dmabuf_ops() - verify that all memory operations required for
792 * DMABUF queue type have been provided
794 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
796 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
797 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
798 !q
->mem_ops
->unmap_dmabuf
)
805 * __verify_memory_type() - Check whether the memory type and buffer type
806 * passed to a buffer operation are compatible with the queue.
808 static int __verify_memory_type(struct vb2_queue
*q
,
809 enum v4l2_memory memory
, enum v4l2_buf_type type
)
811 if (memory
!= V4L2_MEMORY_MMAP
&& memory
!= V4L2_MEMORY_USERPTR
&&
812 memory
!= V4L2_MEMORY_DMABUF
) {
813 dprintk(1, "unsupported memory type\n");
817 if (type
!= q
->type
) {
818 dprintk(1, "requested type is incorrect\n");
823 * Make sure all the required memory ops for given memory type
826 if (memory
== V4L2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
827 dprintk(1, "MMAP for current setup unsupported\n");
831 if (memory
== V4L2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
832 dprintk(1, "USERPTR for current setup unsupported\n");
836 if (memory
== V4L2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
837 dprintk(1, "DMABUF for current setup unsupported\n");
842 * Place the busy tests at the end: -EBUSY can be ignored when
843 * create_bufs is called with count == 0, but count == 0 should still
844 * do the memory and type validation.
846 if (vb2_fileio_is_active(q
)) {
847 dprintk(1, "file io in progress\n");
854 * __reqbufs() - Initiate streaming
855 * @q: videobuf2 queue
856 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
858 * Should be called from vidioc_reqbufs ioctl handler of a driver.
860 * 1) verifies streaming parameters passed from the userspace,
861 * 2) sets up the queue,
862 * 3) negotiates number of buffers and planes per buffer with the driver
863 * to be used during streaming,
864 * 4) allocates internal buffer structures (struct vb2_buffer), according to
865 * the agreed parameters,
866 * 5) for MMAP memory type, allocates actual video memory, using the
867 * memory handling/allocation routines provided during queue initialization
869 * If req->count is 0, all the memory will be freed instead.
870 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
871 * and the queue is not busy, memory will be reallocated.
873 * The return values from this function are intended to be directly returned
874 * from vidioc_reqbufs handler in driver.
876 static int __reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
878 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
882 dprintk(1, "streaming active\n");
886 if (req
->count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= req
->memory
) {
888 * We already have buffers allocated, so first check if they
889 * are not in use and can be freed.
891 mutex_lock(&q
->mmap_lock
);
892 if (q
->memory
== V4L2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
893 mutex_unlock(&q
->mmap_lock
);
894 dprintk(1, "memory in use, cannot free\n");
899 * Call queue_cancel to clean up any buffers in the PREPARED or
900 * QUEUED state which is possible if buffers were prepared or
901 * queued without ever calling STREAMON.
903 __vb2_queue_cancel(q
);
904 ret
= __vb2_queue_free(q
, q
->num_buffers
);
905 mutex_unlock(&q
->mmap_lock
);
910 * In case of REQBUFS(0) return immediately without calling
911 * driver's queue_setup() callback and allocating resources.
918 * Make sure the requested values and current defaults are sane.
920 num_buffers
= min_t(unsigned int, req
->count
, VIDEO_MAX_FRAME
);
921 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
922 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
923 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
924 q
->memory
= req
->memory
;
927 * Ask the driver how many buffers and planes per buffer it requires.
928 * Driver also sets the size and allocator context for each plane.
930 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
, &num_planes
,
931 q
->plane_sizes
, q
->alloc_ctx
);
935 /* Finally, allocate buffers and video memory */
936 allocated_buffers
= __vb2_queue_alloc(q
, req
->memory
, num_buffers
, num_planes
);
937 if (allocated_buffers
== 0) {
938 dprintk(1, "memory allocation failed\n");
943 * There is no point in continuing if we can't allocate the minimum
944 * number of buffers needed by this vb2_queue.
946 if (allocated_buffers
< q
->min_buffers_needed
)
950 * Check if driver can handle the allocated number of buffers.
952 if (!ret
&& allocated_buffers
< num_buffers
) {
953 num_buffers
= allocated_buffers
;
955 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
,
956 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
958 if (!ret
&& allocated_buffers
< num_buffers
)
962 * Either the driver has accepted a smaller number of buffers,
963 * or .queue_setup() returned an error
967 mutex_lock(&q
->mmap_lock
);
968 q
->num_buffers
= allocated_buffers
;
972 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
973 * from q->num_buffers.
975 __vb2_queue_free(q
, allocated_buffers
);
976 mutex_unlock(&q
->mmap_lock
);
979 mutex_unlock(&q
->mmap_lock
);
982 * Return the number of successfully allocated buffers
985 req
->count
= allocated_buffers
;
986 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
992 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
994 * @q: videobuf2 queue
995 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
997 int vb2_reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
999 int ret
= __verify_memory_type(q
, req
->memory
, req
->type
);
1001 return ret
? ret
: __reqbufs(q
, req
);
1003 EXPORT_SYMBOL_GPL(vb2_reqbufs
);
1006 * __create_bufs() - Allocate buffers and any required auxiliary structs
1007 * @q: videobuf2 queue
1008 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1011 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1013 * 1) verifies parameter sanity
1014 * 2) calls the .queue_setup() queue operation
1015 * 3) performs any necessary memory allocations
1017 * The return values from this function are intended to be directly returned
1018 * from vidioc_create_bufs handler in driver.
1020 static int __create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1022 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
1025 if (q
->num_buffers
== VIDEO_MAX_FRAME
) {
1026 dprintk(1, "maximum number of buffers already allocated\n");
1030 if (!q
->num_buffers
) {
1031 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
1032 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
1033 q
->memory
= create
->memory
;
1034 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1037 num_buffers
= min(create
->count
, VIDEO_MAX_FRAME
- q
->num_buffers
);
1040 * Ask the driver, whether the requested number of buffers, planes per
1041 * buffer and their sizes are acceptable
1043 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1044 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1048 /* Finally, allocate buffers and video memory */
1049 allocated_buffers
= __vb2_queue_alloc(q
, create
->memory
, num_buffers
,
1051 if (allocated_buffers
== 0) {
1052 dprintk(1, "memory allocation failed\n");
1057 * Check if driver can handle the so far allocated number of buffers.
1059 if (allocated_buffers
< num_buffers
) {
1060 num_buffers
= allocated_buffers
;
1063 * q->num_buffers contains the total number of buffers, that the
1064 * queue driver has set up
1066 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1067 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1069 if (!ret
&& allocated_buffers
< num_buffers
)
1073 * Either the driver has accepted a smaller number of buffers,
1074 * or .queue_setup() returned an error
1078 mutex_lock(&q
->mmap_lock
);
1079 q
->num_buffers
+= allocated_buffers
;
1083 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1084 * from q->num_buffers.
1086 __vb2_queue_free(q
, allocated_buffers
);
1087 mutex_unlock(&q
->mmap_lock
);
1090 mutex_unlock(&q
->mmap_lock
);
1093 * Return the number of successfully allocated buffers
1096 create
->count
= allocated_buffers
;
1102 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1103 * memory and type values.
1104 * @q: videobuf2 queue
1105 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1108 int vb2_create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1110 int ret
= __verify_memory_type(q
, create
->memory
, create
->format
.type
);
1112 create
->index
= q
->num_buffers
;
1113 if (create
->count
== 0)
1114 return ret
!= -EBUSY
? ret
: 0;
1115 return ret
? ret
: __create_bufs(q
, create
);
1117 EXPORT_SYMBOL_GPL(vb2_create_bufs
);
1120 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1121 * @vb: vb2_buffer to which the plane in question belongs to
1122 * @plane_no: plane number for which the address is to be returned
1124 * This function returns a kernel virtual address of a given plane if
1125 * such a mapping exist, NULL otherwise.
1127 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
1129 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1132 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
1135 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
1138 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1139 * @vb: vb2_buffer to which the plane in question belongs to
1140 * @plane_no: plane number for which the cookie is to be returned
1142 * This function returns an allocator specific cookie for a given plane if
1143 * available, NULL otherwise. The allocator should provide some simple static
1144 * inline function, which would convert this cookie to the allocator specific
1145 * type that can be used directly by the driver to access the buffer. This can
1146 * be for example physical address, pointer to scatter list or IOMMU mapping.
1148 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
1150 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1153 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
1155 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
1158 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1159 * @vb: vb2_buffer returned from the driver
1160 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1161 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1162 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1163 * If start_streaming fails then it should return buffers with state
1164 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1166 * This function should be called by the driver after a hardware operation on
1167 * a buffer is finished and the buffer may be returned to userspace. The driver
1168 * cannot use this buffer anymore until it is queued back to it by videobuf
1169 * by the means of buf_queue callback. Only buffers previously queued to the
1170 * driver by buf_queue can be passed to this function.
1172 * While streaming a buffer can only be returned in state DONE or ERROR.
1173 * The start_streaming op can also return them in case the DMA engine cannot
1174 * be started for some reason. In that case the buffers should be returned with
1177 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
1179 struct vb2_queue
*q
= vb
->vb2_queue
;
1180 unsigned long flags
;
1183 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
1186 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
1187 state
!= VB2_BUF_STATE_ERROR
&&
1188 state
!= VB2_BUF_STATE_QUEUED
&&
1189 state
!= VB2_BUF_STATE_REQUEUEING
))
1190 state
= VB2_BUF_STATE_ERROR
;
1192 #ifdef CONFIG_VIDEO_ADV_DEBUG
1194 * Although this is not a callback, it still does have to balance
1195 * with the buf_queue op. So update this counter manually.
1199 dprintk(4, "done processing on buffer %d, state: %d\n",
1200 vb
->v4l2_buf
.index
, state
);
1203 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1204 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1206 spin_lock_irqsave(&q
->done_lock
, flags
);
1207 if (state
== VB2_BUF_STATE_QUEUED
||
1208 state
== VB2_BUF_STATE_REQUEUEING
) {
1209 vb
->state
= VB2_BUF_STATE_QUEUED
;
1211 /* Add the buffer to the done buffers list */
1212 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1215 atomic_dec(&q
->owned_by_drv_count
);
1216 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1218 trace_vb2_buf_done(q
, vb
);
1221 case VB2_BUF_STATE_QUEUED
:
1223 case VB2_BUF_STATE_REQUEUEING
:
1224 if (q
->start_streaming_called
)
1225 __enqueue_in_driver(vb
);
1228 /* Inform any processes that may be waiting for buffers */
1229 wake_up(&q
->done_wq
);
1233 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1236 * vb2_discard_done() - discard all buffers marked as DONE
1237 * @q: videobuf2 queue
1239 * This function is intended to be used with suspend/resume operations. It
1240 * discards all 'done' buffers as they would be too old to be requested after
1243 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1244 * delayed works before calling this function to make sure no buffer will be
1245 * touched by the driver and/or hardware.
1247 void vb2_discard_done(struct vb2_queue
*q
)
1249 struct vb2_buffer
*vb
;
1250 unsigned long flags
;
1252 spin_lock_irqsave(&q
->done_lock
, flags
);
1253 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1254 vb
->state
= VB2_BUF_STATE_ERROR
;
1255 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1257 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1259 static void vb2_warn_zero_bytesused(struct vb2_buffer
*vb
)
1261 static bool check_once
;
1269 pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1270 if (vb
->vb2_queue
->allow_zero_bytesused
)
1271 pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1273 pr_warn("use the actual size instead.\n");
1277 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1278 * v4l2_buffer by the userspace. The caller has already verified that struct
1279 * v4l2_buffer has a valid number of planes.
1281 static void __fill_vb2_buffer(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
,
1282 struct v4l2_plane
*v4l2_planes
)
1286 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
1287 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1288 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1289 v4l2_planes
[plane
].m
.userptr
=
1290 b
->m
.planes
[plane
].m
.userptr
;
1291 v4l2_planes
[plane
].length
=
1292 b
->m
.planes
[plane
].length
;
1295 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1296 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1297 v4l2_planes
[plane
].m
.fd
=
1298 b
->m
.planes
[plane
].m
.fd
;
1299 v4l2_planes
[plane
].length
=
1300 b
->m
.planes
[plane
].length
;
1304 /* Fill in driver-provided information for OUTPUT types */
1305 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1307 * Will have to go up to b->length when API starts
1308 * accepting variable number of planes.
1310 * If bytesused == 0 for the output buffer, then fall
1311 * back to the full buffer size. In that case
1312 * userspace clearly never bothered to set it and
1313 * it's a safe assumption that they really meant to
1314 * use the full plane sizes.
1316 * Some drivers, e.g. old codec drivers, use bytesused == 0
1317 * as a way to indicate that streaming is finished.
1318 * In that case, the driver should use the
1319 * allow_zero_bytesused flag to keep old userspace
1320 * applications working.
1322 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1323 struct v4l2_plane
*pdst
= &v4l2_planes
[plane
];
1324 struct v4l2_plane
*psrc
= &b
->m
.planes
[plane
];
1326 if (psrc
->bytesused
== 0)
1327 vb2_warn_zero_bytesused(vb
);
1329 if (vb
->vb2_queue
->allow_zero_bytesused
)
1330 pdst
->bytesused
= psrc
->bytesused
;
1332 pdst
->bytesused
= psrc
->bytesused
?
1333 psrc
->bytesused
: pdst
->length
;
1334 pdst
->data_offset
= psrc
->data_offset
;
1339 * Single-planar buffers do not use planes array,
1340 * so fill in relevant v4l2_buffer struct fields instead.
1341 * In videobuf we use our internal V4l2_planes struct for
1342 * single-planar buffers as well, for simplicity.
1344 * If bytesused == 0 for the output buffer, then fall back
1345 * to the full buffer size as that's a sensible default.
1347 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1348 * a way to indicate that streaming is finished. In that case,
1349 * the driver should use the allow_zero_bytesused flag to keep
1350 * old userspace applications working.
1352 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1353 v4l2_planes
[0].m
.userptr
= b
->m
.userptr
;
1354 v4l2_planes
[0].length
= b
->length
;
1357 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1358 v4l2_planes
[0].m
.fd
= b
->m
.fd
;
1359 v4l2_planes
[0].length
= b
->length
;
1362 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1363 if (b
->bytesused
== 0)
1364 vb2_warn_zero_bytesused(vb
);
1366 if (vb
->vb2_queue
->allow_zero_bytesused
)
1367 v4l2_planes
[0].bytesused
= b
->bytesused
;
1369 v4l2_planes
[0].bytesused
= b
->bytesused
?
1370 b
->bytesused
: v4l2_planes
[0].length
;
1372 v4l2_planes
[0].bytesused
= 0;
1376 /* Zero flags that the vb2 core handles */
1377 vb
->v4l2_buf
.flags
= b
->flags
& ~V4L2_BUFFER_MASK_FLAGS
;
1378 if ((vb
->vb2_queue
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
1379 V4L2_BUF_FLAG_TIMESTAMP_COPY
|| !V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1381 * Non-COPY timestamps and non-OUTPUT queues will get
1382 * their timestamp and timestamp source flags from the
1385 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
1388 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1390 * For output buffers mask out the timecode flag:
1391 * this will be handled later in vb2_internal_qbuf().
1392 * The 'field' is valid metadata for this output buffer
1393 * and so that needs to be copied here.
1395 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TIMECODE
;
1396 vb
->v4l2_buf
.field
= b
->field
;
1398 /* Zero any output buffer flags as this is a capture buffer */
1399 vb
->v4l2_buf
.flags
&= ~V4L2_BUFFER_OUT_FLAGS
;
1404 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1406 static int __qbuf_mmap(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1408 __fill_vb2_buffer(vb
, b
, vb
->v4l2_planes
);
1409 return call_vb_qop(vb
, buf_prepare
, vb
);
1413 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1415 static int __qbuf_userptr(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1417 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1418 struct vb2_queue
*q
= vb
->vb2_queue
;
1422 enum dma_data_direction dma_dir
=
1423 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1424 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1426 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1427 /* Copy relevant information provided by the userspace */
1428 __fill_vb2_buffer(vb
, b
, planes
);
1430 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1431 /* Skip the plane if already verified */
1432 if (vb
->v4l2_planes
[plane
].m
.userptr
&&
1433 vb
->v4l2_planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1434 && vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
)
1437 dprintk(3, "userspace address for plane %d changed, "
1438 "reacquiring memory\n", plane
);
1440 /* Check if the provided plane buffer is large enough */
1441 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1442 dprintk(1, "provided buffer size %u is less than "
1443 "setup size %u for plane %d\n",
1444 planes
[plane
].length
,
1445 q
->plane_sizes
[plane
], plane
);
1450 /* Release previously acquired memory if present */
1451 if (vb
->planes
[plane
].mem_priv
) {
1454 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1456 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1459 vb
->planes
[plane
].mem_priv
= NULL
;
1460 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1462 /* Acquire each plane's memory */
1463 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1464 planes
[plane
].m
.userptr
,
1465 planes
[plane
].length
, dma_dir
);
1466 if (IS_ERR_OR_NULL(mem_priv
)) {
1467 dprintk(1, "failed acquiring userspace "
1468 "memory for plane %d\n", plane
);
1469 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1472 vb
->planes
[plane
].mem_priv
= mem_priv
;
1476 * Now that everything is in order, copy relevant information
1477 * provided by userspace.
1479 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1480 vb
->v4l2_planes
[plane
] = planes
[plane
];
1484 * One or more planes changed, so we must call buf_init to do
1485 * the driver-specific initialization on the newly acquired
1486 * buffer, if provided.
1488 ret
= call_vb_qop(vb
, buf_init
, vb
);
1490 dprintk(1, "buffer initialization failed\n");
1495 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1497 dprintk(1, "buffer preparation failed\n");
1498 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1504 /* In case of errors, release planes that were already acquired */
1505 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1506 if (vb
->planes
[plane
].mem_priv
)
1507 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1508 vb
->planes
[plane
].mem_priv
= NULL
;
1509 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1510 vb
->v4l2_planes
[plane
].length
= 0;
1517 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1519 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1521 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1522 struct vb2_queue
*q
= vb
->vb2_queue
;
1526 enum dma_data_direction dma_dir
=
1527 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1528 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1530 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1531 /* Copy relevant information provided by the userspace */
1532 __fill_vb2_buffer(vb
, b
, planes
);
1534 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1535 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1537 if (IS_ERR_OR_NULL(dbuf
)) {
1538 dprintk(1, "invalid dmabuf fd for plane %d\n",
1544 /* use DMABUF size if length is not provided */
1545 if (planes
[plane
].length
== 0)
1546 planes
[plane
].length
= dbuf
->size
;
1548 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1549 dprintk(1, "invalid dmabuf length for plane %d\n",
1555 /* Skip the plane if already verified */
1556 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1557 vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
) {
1562 dprintk(1, "buffer for plane %d changed\n", plane
);
1566 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1569 /* Release previously acquired memory if present */
1570 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1571 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1573 /* Acquire each plane's memory */
1574 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
, q
->alloc_ctx
[plane
],
1575 dbuf
, planes
[plane
].length
, dma_dir
);
1576 if (IS_ERR(mem_priv
)) {
1577 dprintk(1, "failed to attach dmabuf\n");
1578 ret
= PTR_ERR(mem_priv
);
1583 vb
->planes
[plane
].dbuf
= dbuf
;
1584 vb
->planes
[plane
].mem_priv
= mem_priv
;
1587 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1588 * really we want to do this just before the DMA, not while queueing
1591 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1592 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1594 dprintk(1, "failed to map dmabuf for plane %d\n",
1598 vb
->planes
[plane
].dbuf_mapped
= 1;
1602 * Now that everything is in order, copy relevant information
1603 * provided by userspace.
1605 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1606 vb
->v4l2_planes
[plane
] = planes
[plane
];
1610 * Call driver-specific initialization on the newly acquired buffer,
1613 ret
= call_vb_qop(vb
, buf_init
, vb
);
1615 dprintk(1, "buffer initialization failed\n");
1620 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1622 dprintk(1, "buffer preparation failed\n");
1623 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1629 /* In case of errors, release planes that were already acquired */
1630 __vb2_buf_dmabuf_put(vb
);
1636 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1638 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1640 struct vb2_queue
*q
= vb
->vb2_queue
;
1643 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1644 atomic_inc(&q
->owned_by_drv_count
);
1646 trace_vb2_buf_queue(q
, vb
);
1649 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1650 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1652 call_void_vb_qop(vb
, buf_queue
, vb
);
1655 static int __buf_prepare(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1657 struct vb2_queue
*q
= vb
->vb2_queue
;
1660 ret
= __verify_length(vb
, b
);
1662 dprintk(1, "plane parameters verification failed: %d\n", ret
);
1665 if (b
->field
== V4L2_FIELD_ALTERNATE
&& V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1667 * If the format's field is ALTERNATE, then the buffer's field
1668 * should be either TOP or BOTTOM, not ALTERNATE since that
1669 * makes no sense. The driver has to know whether the
1670 * buffer represents a top or a bottom field in order to
1671 * program any DMA correctly. Using ALTERNATE is wrong, since
1672 * that just says that it is either a top or a bottom field,
1673 * but not which of the two it is.
1675 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1680 dprintk(1, "fatal error occurred on queue\n");
1684 vb
->state
= VB2_BUF_STATE_PREPARING
;
1685 vb
->v4l2_buf
.timestamp
.tv_sec
= 0;
1686 vb
->v4l2_buf
.timestamp
.tv_usec
= 0;
1687 vb
->v4l2_buf
.sequence
= 0;
1689 switch (q
->memory
) {
1690 case V4L2_MEMORY_MMAP
:
1691 ret
= __qbuf_mmap(vb
, b
);
1693 case V4L2_MEMORY_USERPTR
:
1694 down_read(¤t
->mm
->mmap_sem
);
1695 ret
= __qbuf_userptr(vb
, b
);
1696 up_read(¤t
->mm
->mmap_sem
);
1698 case V4L2_MEMORY_DMABUF
:
1699 ret
= __qbuf_dmabuf(vb
, b
);
1702 WARN(1, "Invalid queue type\n");
1707 dprintk(1, "buffer preparation failed: %d\n", ret
);
1708 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1713 static int vb2_queue_or_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
,
1716 if (b
->type
!= q
->type
) {
1717 dprintk(1, "%s: invalid buffer type\n", opname
);
1721 if (b
->index
>= q
->num_buffers
) {
1722 dprintk(1, "%s: buffer index out of range\n", opname
);
1726 if (q
->bufs
[b
->index
] == NULL
) {
1727 /* Should never happen */
1728 dprintk(1, "%s: buffer is NULL\n", opname
);
1732 if (b
->memory
!= q
->memory
) {
1733 dprintk(1, "%s: invalid memory type\n", opname
);
1737 return __verify_planes_array(q
->bufs
[b
->index
], b
);
1741 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1742 * @q: videobuf2 queue
1743 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1746 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1748 * 1) verifies the passed buffer,
1749 * 2) calls buf_prepare callback in the driver (if provided), in which
1750 * driver-specific buffer initialization can be performed,
1752 * The return values from this function are intended to be directly returned
1753 * from vidioc_prepare_buf handler in driver.
1755 int vb2_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1757 struct vb2_buffer
*vb
;
1760 if (vb2_fileio_is_active(q
)) {
1761 dprintk(1, "file io in progress\n");
1765 ret
= vb2_queue_or_prepare_buf(q
, b
, "prepare_buf");
1769 vb
= q
->bufs
[b
->index
];
1770 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1771 dprintk(1, "invalid buffer state %d\n",
1776 ret
= __buf_prepare(vb
, b
);
1778 /* Fill buffer information for the userspace */
1779 __fill_v4l2_buffer(vb
, b
);
1781 dprintk(1, "prepare of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1785 EXPORT_SYMBOL_GPL(vb2_prepare_buf
);
1788 * vb2_start_streaming() - Attempt to start streaming.
1789 * @q: videobuf2 queue
1791 * Attempt to start streaming. When this function is called there must be
1792 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1793 * number of buffers required for the DMA engine to function). If the
1794 * @start_streaming op fails it is supposed to return all the driver-owned
1795 * buffers back to vb2 in state QUEUED. Check if that happened and if
1796 * not warn and reclaim them forcefully.
1798 static int vb2_start_streaming(struct vb2_queue
*q
)
1800 struct vb2_buffer
*vb
;
1804 * If any buffers were queued before streamon,
1805 * we can now pass them to driver for processing.
1807 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1808 __enqueue_in_driver(vb
);
1810 /* Tell the driver to start streaming */
1811 q
->start_streaming_called
= 1;
1812 ret
= call_qop(q
, start_streaming
, q
,
1813 atomic_read(&q
->owned_by_drv_count
));
1817 q
->start_streaming_called
= 0;
1819 dprintk(1, "driver refused to start streaming\n");
1821 * If you see this warning, then the driver isn't cleaning up properly
1822 * after a failed start_streaming(). See the start_streaming()
1823 * documentation in videobuf2-core.h for more information how buffers
1824 * should be returned to vb2 in start_streaming().
1826 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1830 * Forcefully reclaim buffers if the driver did not
1831 * correctly return them to vb2.
1833 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1835 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1836 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1838 /* Must be zero now */
1839 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1842 * If done_list is not empty, then start_streaming() didn't call
1843 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1846 WARN_ON(!list_empty(&q
->done_list
));
1850 static int vb2_internal_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1852 int ret
= vb2_queue_or_prepare_buf(q
, b
, "qbuf");
1853 struct vb2_buffer
*vb
;
1858 vb
= q
->bufs
[b
->index
];
1860 switch (vb
->state
) {
1861 case VB2_BUF_STATE_DEQUEUED
:
1862 ret
= __buf_prepare(vb
, b
);
1866 case VB2_BUF_STATE_PREPARED
:
1868 case VB2_BUF_STATE_PREPARING
:
1869 dprintk(1, "buffer still being prepared\n");
1872 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1877 * Add to the queued buffers list, a buffer will stay on it until
1878 * dequeued in dqbuf.
1880 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1882 q
->waiting_for_buffers
= false;
1883 vb
->state
= VB2_BUF_STATE_QUEUED
;
1884 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1886 * For output buffers copy the timestamp if needed,
1887 * and the timecode field and flag if needed.
1889 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
1890 V4L2_BUF_FLAG_TIMESTAMP_COPY
)
1891 vb
->v4l2_buf
.timestamp
= b
->timestamp
;
1892 vb
->v4l2_buf
.flags
|= b
->flags
& V4L2_BUF_FLAG_TIMECODE
;
1893 if (b
->flags
& V4L2_BUF_FLAG_TIMECODE
)
1894 vb
->v4l2_buf
.timecode
= b
->timecode
;
1897 trace_vb2_qbuf(q
, vb
);
1900 * If already streaming, give the buffer to driver for processing.
1901 * If not, the buffer will be given to driver on next streamon.
1903 if (q
->start_streaming_called
)
1904 __enqueue_in_driver(vb
);
1906 /* Fill buffer information for the userspace */
1907 __fill_v4l2_buffer(vb
, b
);
1910 * If streamon has been called, and we haven't yet called
1911 * start_streaming() since not enough buffers were queued, and
1912 * we now have reached the minimum number of queued buffers,
1913 * then we can finally call start_streaming().
1915 if (q
->streaming
&& !q
->start_streaming_called
&&
1916 q
->queued_count
>= q
->min_buffers_needed
) {
1917 ret
= vb2_start_streaming(q
);
1922 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1927 * vb2_qbuf() - Queue a buffer from userspace
1928 * @q: videobuf2 queue
1929 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1932 * Should be called from vidioc_qbuf ioctl handler of a driver.
1934 * 1) verifies the passed buffer,
1935 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1936 * which driver-specific buffer initialization can be performed,
1937 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1938 * callback for processing.
1940 * The return values from this function are intended to be directly returned
1941 * from vidioc_qbuf handler in driver.
1943 int vb2_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1945 if (vb2_fileio_is_active(q
)) {
1946 dprintk(1, "file io in progress\n");
1950 return vb2_internal_qbuf(q
, b
);
1952 EXPORT_SYMBOL_GPL(vb2_qbuf
);
1955 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1958 * Will sleep if required for nonblocking == false.
1960 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1963 * All operations on vb_done_list are performed under done_lock
1964 * spinlock protection. However, buffers may be removed from
1965 * it and returned to userspace only while holding both driver's
1966 * lock and the done_lock spinlock. Thus we can be sure that as
1967 * long as we hold the driver's lock, the list will remain not
1968 * empty if list_empty() check succeeds.
1974 if (!q
->streaming
) {
1975 dprintk(1, "streaming off, will not wait for buffers\n");
1980 dprintk(1, "Queue in error state, will not wait for buffers\n");
1984 if (q
->last_buffer_dequeued
) {
1985 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1989 if (!list_empty(&q
->done_list
)) {
1991 * Found a buffer that we were waiting for.
1997 dprintk(1, "nonblocking and no buffers to dequeue, "
2003 * We are streaming and blocking, wait for another buffer to
2004 * become ready or for streamoff. Driver's lock is released to
2005 * allow streamoff or qbuf to be called while waiting.
2007 call_void_qop(q
, wait_prepare
, q
);
2010 * All locks have been released, it is safe to sleep now.
2012 dprintk(3, "will sleep waiting for buffers\n");
2013 ret
= wait_event_interruptible(q
->done_wq
,
2014 !list_empty(&q
->done_list
) || !q
->streaming
||
2018 * We need to reevaluate both conditions again after reacquiring
2019 * the locks or return an error if one occurred.
2021 call_void_qop(q
, wait_finish
, q
);
2023 dprintk(1, "sleep was interrupted\n");
2031 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2033 * Will sleep if required for nonblocking == false.
2035 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
2036 struct v4l2_buffer
*b
, int nonblocking
)
2038 unsigned long flags
;
2042 * Wait for at least one buffer to become available on the done_list.
2044 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
2049 * Driver's lock has been held since we last verified that done_list
2050 * is not empty, so no need for another list_empty(done_list) check.
2052 spin_lock_irqsave(&q
->done_lock
, flags
);
2053 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
2055 * Only remove the buffer from done_list if v4l2_buffer can handle all
2058 ret
= __verify_planes_array(*vb
, b
);
2060 list_del(&(*vb
)->done_entry
);
2061 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2067 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2068 * @q: videobuf2 queue
2070 * This function will wait until all buffers that have been given to the driver
2071 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2072 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2073 * taken, for example from stop_streaming() callback.
2075 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
2077 if (!q
->streaming
) {
2078 dprintk(1, "streaming off, will not wait for buffers\n");
2082 if (q
->start_streaming_called
)
2083 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
2086 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
2089 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2091 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
2093 struct vb2_queue
*q
= vb
->vb2_queue
;
2096 /* nothing to do if the buffer is already dequeued */
2097 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
2100 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
2102 /* unmap DMABUF buffer */
2103 if (q
->memory
== V4L2_MEMORY_DMABUF
)
2104 for (i
= 0; i
< vb
->num_planes
; ++i
) {
2105 if (!vb
->planes
[i
].dbuf_mapped
)
2107 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
2108 vb
->planes
[i
].dbuf_mapped
= 0;
2112 static int vb2_internal_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2114 struct vb2_buffer
*vb
= NULL
;
2117 if (b
->type
!= q
->type
) {
2118 dprintk(1, "invalid buffer type\n");
2121 ret
= __vb2_get_done_vb(q
, &vb
, b
, nonblocking
);
2125 switch (vb
->state
) {
2126 case VB2_BUF_STATE_DONE
:
2127 dprintk(3, "returning done buffer\n");
2129 case VB2_BUF_STATE_ERROR
:
2130 dprintk(3, "returning done buffer with errors\n");
2133 dprintk(1, "invalid buffer state\n");
2137 call_void_vb_qop(vb
, buf_finish
, vb
);
2139 /* Fill buffer information for the userspace */
2140 __fill_v4l2_buffer(vb
, b
);
2141 /* Remove from videobuf queue */
2142 list_del(&vb
->queued_entry
);
2145 trace_vb2_dqbuf(q
, vb
);
2147 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) &&
2148 vb
->v4l2_buf
.flags
& V4L2_BUF_FLAG_LAST
)
2149 q
->last_buffer_dequeued
= true;
2150 /* go back to dequeued state */
2153 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2154 vb
->v4l2_buf
.index
, vb
->state
);
2160 * vb2_dqbuf() - Dequeue a buffer to the userspace
2161 * @q: videobuf2 queue
2162 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2164 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2165 * buffers ready for dequeuing are present. Normally the driver
2166 * would be passing (file->f_flags & O_NONBLOCK) here
2168 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2170 * 1) verifies the passed buffer,
2171 * 2) calls buf_finish callback in the driver (if provided), in which
2172 * driver can perform any additional operations that may be required before
2173 * returning the buffer to userspace, such as cache sync,
2174 * 3) the buffer struct members are filled with relevant information for
2177 * The return values from this function are intended to be directly returned
2178 * from vidioc_dqbuf handler in driver.
2180 int vb2_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2182 if (vb2_fileio_is_active(q
)) {
2183 dprintk(1, "file io in progress\n");
2186 return vb2_internal_dqbuf(q
, b
, nonblocking
);
2188 EXPORT_SYMBOL_GPL(vb2_dqbuf
);
2191 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2193 * Removes all queued buffers from driver's queue and all buffers queued by
2194 * userspace from videobuf's queue. Returns to state after reqbufs.
2196 static void __vb2_queue_cancel(struct vb2_queue
*q
)
2201 * Tell driver to stop all transactions and release all queued
2204 if (q
->start_streaming_called
)
2205 call_void_qop(q
, stop_streaming
, q
);
2208 * If you see this warning, then the driver isn't cleaning up properly
2209 * in stop_streaming(). See the stop_streaming() documentation in
2210 * videobuf2-core.h for more information how buffers should be returned
2211 * to vb2 in stop_streaming().
2213 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
2214 for (i
= 0; i
< q
->num_buffers
; ++i
)
2215 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
2216 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
2217 /* Must be zero now */
2218 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
2222 q
->start_streaming_called
= 0;
2223 q
->queued_count
= 0;
2227 * Remove all buffers from videobuf's list...
2229 INIT_LIST_HEAD(&q
->queued_list
);
2231 * ...and done list; userspace will not receive any buffers it
2232 * has not already dequeued before initiating cancel.
2234 INIT_LIST_HEAD(&q
->done_list
);
2235 atomic_set(&q
->owned_by_drv_count
, 0);
2236 wake_up_all(&q
->done_wq
);
2239 * Reinitialize all buffers for next use.
2240 * Make sure to call buf_finish for any queued buffers. Normally
2241 * that's done in dqbuf, but that's not going to happen when we
2242 * cancel the whole queue. Note: this code belongs here, not in
2243 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2244 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2245 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2247 for (i
= 0; i
< q
->num_buffers
; ++i
) {
2248 struct vb2_buffer
*vb
= q
->bufs
[i
];
2250 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
2251 vb
->state
= VB2_BUF_STATE_PREPARED
;
2252 call_void_vb_qop(vb
, buf_finish
, vb
);
2258 static int vb2_internal_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2262 if (type
!= q
->type
) {
2263 dprintk(1, "invalid stream type\n");
2268 dprintk(3, "already streaming\n");
2272 if (!q
->num_buffers
) {
2273 dprintk(1, "no buffers have been allocated\n");
2277 if (q
->num_buffers
< q
->min_buffers_needed
) {
2278 dprintk(1, "need at least %u allocated buffers\n",
2279 q
->min_buffers_needed
);
2284 * Tell driver to start streaming provided sufficient buffers
2287 if (q
->queued_count
>= q
->min_buffers_needed
) {
2288 ret
= vb2_start_streaming(q
);
2290 __vb2_queue_cancel(q
);
2297 dprintk(3, "successful\n");
2302 * vb2_queue_error() - signal a fatal error on the queue
2303 * @q: videobuf2 queue
2305 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2306 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2307 * buffers will return -EIO.
2309 * The error flag will be cleared when cancelling the queue, either from
2310 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2311 * function before starting the stream, otherwise the error flag will remain set
2312 * until the queue is released when closing the device node.
2314 void vb2_queue_error(struct vb2_queue
*q
)
2318 wake_up_all(&q
->done_wq
);
2320 EXPORT_SYMBOL_GPL(vb2_queue_error
);
2323 * vb2_streamon - start streaming
2324 * @q: videobuf2 queue
2325 * @type: type argument passed from userspace to vidioc_streamon handler
2327 * Should be called from vidioc_streamon handler of a driver.
2329 * 1) verifies current state
2330 * 2) passes any previously queued buffers to the driver and starts streaming
2332 * The return values from this function are intended to be directly returned
2333 * from vidioc_streamon handler in the driver.
2335 int vb2_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2337 if (vb2_fileio_is_active(q
)) {
2338 dprintk(1, "file io in progress\n");
2341 return vb2_internal_streamon(q
, type
);
2343 EXPORT_SYMBOL_GPL(vb2_streamon
);
2345 static int vb2_internal_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2347 if (type
!= q
->type
) {
2348 dprintk(1, "invalid stream type\n");
2353 * Cancel will pause streaming and remove all buffers from the driver
2354 * and videobuf, effectively returning control over them to userspace.
2356 * Note that we do this even if q->streaming == 0: if you prepare or
2357 * queue buffers, and then call streamoff without ever having called
2358 * streamon, you would still expect those buffers to be returned to
2359 * their normal dequeued state.
2361 __vb2_queue_cancel(q
);
2362 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
2363 q
->last_buffer_dequeued
= false;
2365 dprintk(3, "successful\n");
2370 * vb2_streamoff - stop streaming
2371 * @q: videobuf2 queue
2372 * @type: type argument passed from userspace to vidioc_streamoff handler
2374 * Should be called from vidioc_streamoff handler of a driver.
2376 * 1) verifies current state,
2377 * 2) stop streaming and dequeues any queued buffers, including those previously
2378 * passed to the driver (after waiting for the driver to finish).
2380 * This call can be used for pausing playback.
2381 * The return values from this function are intended to be directly returned
2382 * from vidioc_streamoff handler in the driver
2384 int vb2_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2386 if (vb2_fileio_is_active(q
)) {
2387 dprintk(1, "file io in progress\n");
2390 return vb2_internal_streamoff(q
, type
);
2392 EXPORT_SYMBOL_GPL(vb2_streamoff
);
2395 * __find_plane_by_offset() - find plane associated with the given offset off
2397 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
2398 unsigned int *_buffer
, unsigned int *_plane
)
2400 struct vb2_buffer
*vb
;
2401 unsigned int buffer
, plane
;
2404 * Go over all buffers and their planes, comparing the given offset
2405 * with an offset assigned to each plane. If a match is found,
2406 * return its buffer and plane numbers.
2408 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
2409 vb
= q
->bufs
[buffer
];
2411 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
2412 if (vb
->v4l2_planes
[plane
].m
.mem_offset
== off
) {
2424 * vb2_expbuf() - Export a buffer as a file descriptor
2425 * @q: videobuf2 queue
2426 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2429 * The return values from this function are intended to be directly returned
2430 * from vidioc_expbuf handler in driver.
2432 int vb2_expbuf(struct vb2_queue
*q
, struct v4l2_exportbuffer
*eb
)
2434 struct vb2_buffer
*vb
= NULL
;
2435 struct vb2_plane
*vb_plane
;
2437 struct dma_buf
*dbuf
;
2439 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2440 dprintk(1, "queue is not currently set up for mmap\n");
2444 if (!q
->mem_ops
->get_dmabuf
) {
2445 dprintk(1, "queue does not support DMA buffer exporting\n");
2449 if (eb
->flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2450 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2454 if (eb
->type
!= q
->type
) {
2455 dprintk(1, "invalid buffer type\n");
2459 if (eb
->index
>= q
->num_buffers
) {
2460 dprintk(1, "buffer index out of range\n");
2464 vb
= q
->bufs
[eb
->index
];
2466 if (eb
->plane
>= vb
->num_planes
) {
2467 dprintk(1, "buffer plane out of range\n");
2471 if (vb2_fileio_is_active(q
)) {
2472 dprintk(1, "expbuf: file io in progress\n");
2476 vb_plane
= &vb
->planes
[eb
->plane
];
2478 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
, eb
->flags
& O_ACCMODE
);
2479 if (IS_ERR_OR_NULL(dbuf
)) {
2480 dprintk(1, "failed to export buffer %d, plane %d\n",
2481 eb
->index
, eb
->plane
);
2485 ret
= dma_buf_fd(dbuf
, eb
->flags
& ~O_ACCMODE
);
2487 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2488 eb
->index
, eb
->plane
, ret
);
2493 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2494 eb
->index
, eb
->plane
, ret
);
2499 EXPORT_SYMBOL_GPL(vb2_expbuf
);
2502 * vb2_mmap() - map video buffers into application address space
2503 * @q: videobuf2 queue
2504 * @vma: vma passed to the mmap file operation handler in the driver
2506 * Should be called from mmap file operation handler of a driver.
2507 * This function maps one plane of one of the available video buffers to
2508 * userspace. To map whole video memory allocated on reqbufs, this function
2509 * has to be called once per each plane per each buffer previously allocated.
2511 * When the userspace application calls mmap, it passes to it an offset returned
2512 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2513 * a "cookie", which is then used to identify the plane to be mapped.
2514 * This function finds a plane with a matching offset and a mapping is performed
2515 * by the means of a provided memory operation.
2517 * The return values from this function are intended to be directly returned
2518 * from the mmap handler in driver.
2520 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2522 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2523 struct vb2_buffer
*vb
;
2524 unsigned int buffer
= 0, plane
= 0;
2526 unsigned long length
;
2528 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2529 dprintk(1, "queue is not currently set up for mmap\n");
2534 * Check memory area access mode.
2536 if (!(vma
->vm_flags
& VM_SHARED
)) {
2537 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2540 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
2541 if (!(vma
->vm_flags
& VM_WRITE
)) {
2542 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2546 if (!(vma
->vm_flags
& VM_READ
)) {
2547 dprintk(1, "invalid vma flags, VM_READ needed\n");
2551 if (vb2_fileio_is_active(q
)) {
2552 dprintk(1, "mmap: file io in progress\n");
2557 * Find the plane corresponding to the offset passed by userspace.
2559 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2563 vb
= q
->bufs
[buffer
];
2566 * MMAP requires page_aligned buffers.
2567 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2568 * so, we need to do the same here.
2570 length
= PAGE_ALIGN(vb
->v4l2_planes
[plane
].length
);
2571 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2573 "MMAP invalid, as it would overflow buffer length\n");
2577 mutex_lock(&q
->mmap_lock
);
2578 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2579 mutex_unlock(&q
->mmap_lock
);
2583 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2586 EXPORT_SYMBOL_GPL(vb2_mmap
);
2589 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2592 unsigned long pgoff
,
2593 unsigned long flags
)
2595 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2596 struct vb2_buffer
*vb
;
2597 unsigned int buffer
, plane
;
2601 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2602 dprintk(1, "queue is not currently set up for mmap\n");
2607 * Find the plane corresponding to the offset passed by userspace.
2609 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2613 vb
= q
->bufs
[buffer
];
2615 vaddr
= vb2_plane_vaddr(vb
, plane
);
2616 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2618 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2621 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2622 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2625 * vb2_poll() - implements poll userspace operation
2626 * @q: videobuf2 queue
2627 * @file: file argument passed to the poll file operation handler
2628 * @wait: wait argument passed to the poll file operation handler
2630 * This function implements poll file operation handler for a driver.
2631 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2632 * be informed that the file descriptor of a video device is available for
2634 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2635 * will be reported as available for writing.
2637 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2640 * The return values from this function are intended to be directly returned
2641 * from poll handler in driver.
2643 unsigned int vb2_poll(struct vb2_queue
*q
, struct file
*file
, poll_table
*wait
)
2645 struct video_device
*vfd
= video_devdata(file
);
2646 unsigned long req_events
= poll_requested_events(wait
);
2647 struct vb2_buffer
*vb
= NULL
;
2648 unsigned int res
= 0;
2649 unsigned long flags
;
2651 if (test_bit(V4L2_FL_USES_V4L2_FH
, &vfd
->flags
)) {
2652 struct v4l2_fh
*fh
= file
->private_data
;
2654 if (v4l2_event_pending(fh
))
2656 else if (req_events
& POLLPRI
)
2657 poll_wait(file
, &fh
->wait
, wait
);
2660 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLIN
| POLLRDNORM
)))
2662 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLOUT
| POLLWRNORM
)))
2666 * Start file I/O emulator only if streaming API has not been used yet.
2668 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2669 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2670 (req_events
& (POLLIN
| POLLRDNORM
))) {
2671 if (__vb2_init_fileio(q
, 1))
2672 return res
| POLLERR
;
2674 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2675 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2676 if (__vb2_init_fileio(q
, 0))
2677 return res
| POLLERR
;
2679 * Write to OUTPUT queue can be done immediately.
2681 return res
| POLLOUT
| POLLWRNORM
;
2686 * There is nothing to wait for if the queue isn't streaming, or if the
2687 * error flag is set.
2689 if (!vb2_is_streaming(q
) || q
->error
)
2690 return res
| POLLERR
;
2692 * For compatibility with vb1: if QBUF hasn't been called yet, then
2693 * return POLLERR as well. This only affects capture queues, output
2694 * queues will always initialize waiting_for_buffers to false.
2696 if (q
->waiting_for_buffers
)
2697 return res
| POLLERR
;
2700 * For output streams you can write as long as there are fewer buffers
2701 * queued than there are buffers available.
2703 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && q
->queued_count
< q
->num_buffers
)
2704 return res
| POLLOUT
| POLLWRNORM
;
2706 if (list_empty(&q
->done_list
)) {
2708 * If the last buffer was dequeued from a capture queue,
2709 * return immediately. DQBUF will return -EPIPE.
2711 if (q
->last_buffer_dequeued
)
2712 return res
| POLLIN
| POLLRDNORM
;
2714 poll_wait(file
, &q
->done_wq
, wait
);
2718 * Take first buffer available for dequeuing.
2720 spin_lock_irqsave(&q
->done_lock
, flags
);
2721 if (!list_empty(&q
->done_list
))
2722 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2724 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2726 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2727 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2728 return (V4L2_TYPE_IS_OUTPUT(q
->type
)) ?
2729 res
| POLLOUT
| POLLWRNORM
:
2730 res
| POLLIN
| POLLRDNORM
;
2734 EXPORT_SYMBOL_GPL(vb2_poll
);
2737 * vb2_queue_init() - initialize a videobuf2 queue
2738 * @q: videobuf2 queue; this structure should be allocated in driver
2740 * The vb2_queue structure should be allocated by the driver. The driver is
2741 * responsible of clearing it's content and setting initial values for some
2742 * required entries before calling this function.
2743 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2744 * to the struct vb2_queue description in include/media/videobuf2-core.h
2745 * for more information.
2747 int vb2_queue_init(struct vb2_queue
*q
)
2754 WARN_ON(!q
->mem_ops
) ||
2755 WARN_ON(!q
->type
) ||
2756 WARN_ON(!q
->io_modes
) ||
2757 WARN_ON(!q
->ops
->queue_setup
) ||
2758 WARN_ON(!q
->ops
->buf_queue
) ||
2759 WARN_ON(q
->timestamp_flags
&
2760 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK
|
2761 V4L2_BUF_FLAG_TSTAMP_SRC_MASK
)))
2764 /* Warn that the driver should choose an appropriate timestamp type */
2765 WARN_ON((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2766 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN
);
2768 INIT_LIST_HEAD(&q
->queued_list
);
2769 INIT_LIST_HEAD(&q
->done_list
);
2770 spin_lock_init(&q
->done_lock
);
2771 mutex_init(&q
->mmap_lock
);
2772 init_waitqueue_head(&q
->done_wq
);
2774 if (q
->buf_struct_size
== 0)
2775 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2779 EXPORT_SYMBOL_GPL(vb2_queue_init
);
2782 * vb2_queue_release() - stop streaming, release the queue and free memory
2783 * @q: videobuf2 queue
2785 * This function stops streaming and performs necessary clean ups, including
2786 * freeing video buffer memory. The driver is responsible for freeing
2787 * the vb2_queue structure itself.
2789 void vb2_queue_release(struct vb2_queue
*q
)
2791 __vb2_cleanup_fileio(q
);
2792 __vb2_queue_cancel(q
);
2793 mutex_lock(&q
->mmap_lock
);
2794 __vb2_queue_free(q
, q
->num_buffers
);
2795 mutex_unlock(&q
->mmap_lock
);
2797 EXPORT_SYMBOL_GPL(vb2_queue_release
);
2800 * struct vb2_fileio_buf - buffer context used by file io emulator
2802 * vb2 provides a compatibility layer and emulator of file io (read and
2803 * write) calls on top of streaming API. This structure is used for
2804 * tracking context related to the buffers.
2806 struct vb2_fileio_buf
{
2810 unsigned int queued
:1;
2814 * struct vb2_fileio_data - queue context used by file io emulator
2816 * @cur_index: the index of the buffer currently being read from or
2817 * written to. If equal to q->num_buffers then a new buffer
2819 * @initial_index: in the read() case all buffers are queued up immediately
2820 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2821 * buffers. However, in the write() case no buffers are initially
2822 * queued, instead whenever a buffer is full it is queued up by
2823 * __vb2_perform_fileio(). Only once all available buffers have
2824 * been queued up will __vb2_perform_fileio() start to dequeue
2825 * buffers. This means that initially __vb2_perform_fileio()
2826 * needs to know what buffer index to use when it is queuing up
2827 * the buffers for the first time. That initial index is stored
2828 * in this field. Once it is equal to q->num_buffers all
2829 * available buffers have been queued and __vb2_perform_fileio()
2830 * should start the normal dequeue/queue cycle.
2832 * vb2 provides a compatibility layer and emulator of file io (read and
2833 * write) calls on top of streaming API. For proper operation it required
2834 * this structure to save the driver state between each call of the read
2835 * or write function.
2837 struct vb2_fileio_data
{
2838 struct v4l2_requestbuffers req
;
2839 struct v4l2_plane p
;
2840 struct v4l2_buffer b
;
2841 struct vb2_fileio_buf bufs
[VIDEO_MAX_FRAME
];
2842 unsigned int cur_index
;
2843 unsigned int initial_index
;
2844 unsigned int q_count
;
2845 unsigned int dq_count
;
2846 unsigned read_once
:1;
2847 unsigned write_immediately
:1;
2851 * __vb2_init_fileio() - initialize file io emulator
2852 * @q: videobuf2 queue
2853 * @read: mode selector (1 means read, 0 means write)
2855 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2857 struct vb2_fileio_data
*fileio
;
2859 unsigned int count
= 0;
2864 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2865 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2869 * Check if device supports mapping buffers to kernel virtual space.
2871 if (!q
->mem_ops
->vaddr
)
2875 * Check if streaming api has not been already activated.
2877 if (q
->streaming
|| q
->num_buffers
> 0)
2881 * Start with count 1, driver can increase it in queue_setup()
2885 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2886 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2887 q
->fileio_write_immediately
);
2889 fileio
= kzalloc(sizeof(struct vb2_fileio_data
), GFP_KERNEL
);
2893 fileio
->read_once
= q
->fileio_read_once
;
2894 fileio
->write_immediately
= q
->fileio_write_immediately
;
2897 * Request buffers and use MMAP type to force driver
2898 * to allocate buffers by itself.
2900 fileio
->req
.count
= count
;
2901 fileio
->req
.memory
= V4L2_MEMORY_MMAP
;
2902 fileio
->req
.type
= q
->type
;
2904 ret
= __reqbufs(q
, &fileio
->req
);
2909 * Check if plane_count is correct
2910 * (multiplane buffers are not supported).
2912 if (q
->bufs
[0]->num_planes
!= 1) {
2918 * Get kernel address of each buffer.
2920 for (i
= 0; i
< q
->num_buffers
; i
++) {
2921 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2922 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2926 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2930 * Read mode requires pre queuing of all buffers.
2933 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2936 * Queue all buffers.
2938 for (i
= 0; i
< q
->num_buffers
; i
++) {
2939 struct v4l2_buffer
*b
= &fileio
->b
;
2941 memset(b
, 0, sizeof(*b
));
2943 if (is_multiplanar
) {
2944 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2945 b
->m
.planes
= &fileio
->p
;
2948 b
->memory
= q
->memory
;
2950 ret
= vb2_internal_qbuf(q
, b
);
2953 fileio
->bufs
[i
].queued
= 1;
2956 * All buffers have been queued, so mark that by setting
2957 * initial_index to q->num_buffers
2959 fileio
->initial_index
= q
->num_buffers
;
2960 fileio
->cur_index
= q
->num_buffers
;
2966 ret
= vb2_internal_streamon(q
, q
->type
);
2973 fileio
->req
.count
= 0;
2974 __reqbufs(q
, &fileio
->req
);
2983 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2984 * @q: videobuf2 queue
2986 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2988 struct vb2_fileio_data
*fileio
= q
->fileio
;
2991 vb2_internal_streamoff(q
, q
->type
);
2993 fileio
->req
.count
= 0;
2994 vb2_reqbufs(q
, &fileio
->req
);
2996 dprintk(3, "file io emulator closed\n");
3002 * __vb2_perform_fileio() - perform a single file io (read or write) operation
3003 * @q: videobuf2 queue
3004 * @data: pointed to target userspace buffer
3005 * @count: number of bytes to read or write
3006 * @ppos: file handle position tracking pointer
3007 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
3008 * @read: access mode selector (1 means read, 0 means write)
3010 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
3011 loff_t
*ppos
, int nonblock
, int read
)
3013 struct vb2_fileio_data
*fileio
;
3014 struct vb2_fileio_buf
*buf
;
3015 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
3017 * When using write() to write data to an output video node the vb2 core
3018 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
3019 * else is able to provide this information with the write() operation.
3021 bool set_timestamp
= !read
&&
3022 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3023 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3026 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
3027 read
? "read" : "write", (long)*ppos
, count
,
3028 nonblock
? "non" : "");
3034 * Initialize emulator on first call.
3036 if (!vb2_fileio_is_active(q
)) {
3037 ret
= __vb2_init_fileio(q
, read
);
3038 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
3045 * Check if we need to dequeue the buffer.
3047 index
= fileio
->cur_index
;
3048 if (index
>= q
->num_buffers
) {
3050 * Call vb2_dqbuf to get buffer back.
3052 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3053 fileio
->b
.type
= q
->type
;
3054 fileio
->b
.memory
= q
->memory
;
3055 if (is_multiplanar
) {
3056 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3057 fileio
->b
.m
.planes
= &fileio
->p
;
3058 fileio
->b
.length
= 1;
3060 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, nonblock
);
3061 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
3064 fileio
->dq_count
+= 1;
3066 fileio
->cur_index
= index
= fileio
->b
.index
;
3067 buf
= &fileio
->bufs
[index
];
3070 * Get number of bytes filled by the driver
3074 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
3075 : vb2_plane_size(q
->bufs
[index
], 0);
3076 /* Compensate for data_offset on read in the multiplanar case. */
3077 if (is_multiplanar
&& read
&&
3078 fileio
->b
.m
.planes
[0].data_offset
< buf
->size
) {
3079 buf
->pos
= fileio
->b
.m
.planes
[0].data_offset
;
3080 buf
->size
-= buf
->pos
;
3083 buf
= &fileio
->bufs
[index
];
3087 * Limit count on last few bytes of the buffer.
3089 if (buf
->pos
+ count
> buf
->size
) {
3090 count
= buf
->size
- buf
->pos
;
3091 dprintk(5, "reducing read count: %zd\n", count
);
3095 * Transfer data to userspace.
3097 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3098 count
, index
, buf
->pos
);
3100 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
3102 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
3104 dprintk(3, "error copying data\n");
3115 * Queue next buffer if required.
3117 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
3119 * Check if this is the last buffer to read.
3121 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
3122 dprintk(3, "read limit reached\n");
3123 return __vb2_cleanup_fileio(q
);
3127 * Call vb2_qbuf and give buffer to the driver.
3129 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3130 fileio
->b
.type
= q
->type
;
3131 fileio
->b
.memory
= q
->memory
;
3132 fileio
->b
.index
= index
;
3133 fileio
->b
.bytesused
= buf
->pos
;
3134 if (is_multiplanar
) {
3135 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3136 fileio
->p
.bytesused
= buf
->pos
;
3137 fileio
->b
.m
.planes
= &fileio
->p
;
3138 fileio
->b
.length
= 1;
3141 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3142 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3143 dprintk(5, "vb2_dbuf result: %d\n", ret
);
3148 * Buffer has been queued, update the status
3152 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
3153 fileio
->q_count
+= 1;
3155 * If we are queuing up buffers for the first time, then
3156 * increase initial_index by one.
3158 if (fileio
->initial_index
< q
->num_buffers
)
3159 fileio
->initial_index
++;
3161 * The next buffer to use is either a buffer that's going to be
3162 * queued for the first time (initial_index < q->num_buffers)
3163 * or it is equal to q->num_buffers, meaning that the next
3164 * time we need to dequeue a buffer since we've now queued up
3165 * all the 'first time' buffers.
3167 fileio
->cur_index
= fileio
->initial_index
;
3171 * Return proper number of bytes processed.
3178 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
3179 loff_t
*ppos
, int nonblocking
)
3181 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
3183 EXPORT_SYMBOL_GPL(vb2_read
);
3185 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
3186 loff_t
*ppos
, int nonblocking
)
3188 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
3189 ppos
, nonblocking
, 0);
3191 EXPORT_SYMBOL_GPL(vb2_write
);
3193 struct vb2_threadio_data
{
3194 struct task_struct
*thread
;
3200 static int vb2_thread(void *data
)
3202 struct vb2_queue
*q
= data
;
3203 struct vb2_threadio_data
*threadio
= q
->threadio
;
3204 struct vb2_fileio_data
*fileio
= q
->fileio
;
3205 bool set_timestamp
= false;
3210 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
3211 prequeue
= q
->num_buffers
;
3213 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3214 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3220 struct vb2_buffer
*vb
;
3223 * Call vb2_dqbuf to get buffer back.
3225 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3226 fileio
->b
.type
= q
->type
;
3227 fileio
->b
.memory
= q
->memory
;
3229 fileio
->b
.index
= index
++;
3232 call_void_qop(q
, wait_finish
, q
);
3233 if (!threadio
->stop
)
3234 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, 0);
3235 call_void_qop(q
, wait_prepare
, q
);
3236 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
3238 if (ret
|| threadio
->stop
)
3242 vb
= q
->bufs
[fileio
->b
.index
];
3243 if (!(fileio
->b
.flags
& V4L2_BUF_FLAG_ERROR
))
3244 if (threadio
->fnc(vb
, threadio
->priv
))
3246 call_void_qop(q
, wait_finish
, q
);
3248 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3249 if (!threadio
->stop
)
3250 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3251 call_void_qop(q
, wait_prepare
, q
);
3252 if (ret
|| threadio
->stop
)
3256 /* Hmm, linux becomes *very* unhappy without this ... */
3257 while (!kthread_should_stop()) {
3258 set_current_state(TASK_INTERRUPTIBLE
);
3265 * This function should not be used for anything else but the videobuf2-dvb
3266 * support. If you think you have another good use-case for this, then please
3267 * contact the linux-media mailinglist first.
3269 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
3270 const char *thread_name
)
3272 struct vb2_threadio_data
*threadio
;
3279 if (WARN_ON(q
->fileio
))
3282 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
3283 if (threadio
== NULL
)
3285 threadio
->fnc
= fnc
;
3286 threadio
->priv
= priv
;
3288 ret
= __vb2_init_fileio(q
, !V4L2_TYPE_IS_OUTPUT(q
->type
));
3289 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
3292 q
->threadio
= threadio
;
3293 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
3294 if (IS_ERR(threadio
->thread
)) {
3295 ret
= PTR_ERR(threadio
->thread
);
3296 threadio
->thread
= NULL
;
3302 __vb2_cleanup_fileio(q
);
3307 EXPORT_SYMBOL_GPL(vb2_thread_start
);
3309 int vb2_thread_stop(struct vb2_queue
*q
)
3311 struct vb2_threadio_data
*threadio
= q
->threadio
;
3314 if (threadio
== NULL
)
3316 threadio
->stop
= true;
3317 /* Wake up all pending sleeps in the thread */
3319 err
= kthread_stop(threadio
->thread
);
3320 __vb2_cleanup_fileio(q
);
3321 threadio
->thread
= NULL
;
3326 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
3329 * The following functions are not part of the vb2 core API, but are helper
3330 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3331 * and struct vb2_ops.
3332 * They contain boilerplate code that most if not all drivers have to do
3333 * and so they simplify the driver code.
3336 /* The queue is busy if there is a owner and you are not that owner. */
3337 static inline bool vb2_queue_is_busy(struct video_device
*vdev
, struct file
*file
)
3339 return vdev
->queue
->owner
&& vdev
->queue
->owner
!= file
->private_data
;
3342 /* vb2 ioctl helpers */
3344 int vb2_ioctl_reqbufs(struct file
*file
, void *priv
,
3345 struct v4l2_requestbuffers
*p
)
3347 struct video_device
*vdev
= video_devdata(file
);
3348 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->type
);
3352 if (vb2_queue_is_busy(vdev
, file
))
3354 res
= __reqbufs(vdev
->queue
, p
);
3355 /* If count == 0, then the owner has released all buffers and he
3356 is no longer owner of the queue. Otherwise we have a new owner. */
3358 vdev
->queue
->owner
= p
->count
? file
->private_data
: NULL
;
3361 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs
);
3363 int vb2_ioctl_create_bufs(struct file
*file
, void *priv
,
3364 struct v4l2_create_buffers
*p
)
3366 struct video_device
*vdev
= video_devdata(file
);
3367 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->format
.type
);
3369 p
->index
= vdev
->queue
->num_buffers
;
3370 /* If count == 0, then just check if memory and type are valid.
3371 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3373 return res
!= -EBUSY
? res
: 0;
3376 if (vb2_queue_is_busy(vdev
, file
))
3378 res
= __create_bufs(vdev
->queue
, p
);
3380 vdev
->queue
->owner
= file
->private_data
;
3383 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs
);
3385 int vb2_ioctl_prepare_buf(struct file
*file
, void *priv
,
3386 struct v4l2_buffer
*p
)
3388 struct video_device
*vdev
= video_devdata(file
);
3390 if (vb2_queue_is_busy(vdev
, file
))
3392 return vb2_prepare_buf(vdev
->queue
, p
);
3394 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf
);
3396 int vb2_ioctl_querybuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3398 struct video_device
*vdev
= video_devdata(file
);
3400 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3401 return vb2_querybuf(vdev
->queue
, p
);
3403 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf
);
3405 int vb2_ioctl_qbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3407 struct video_device
*vdev
= video_devdata(file
);
3409 if (vb2_queue_is_busy(vdev
, file
))
3411 return vb2_qbuf(vdev
->queue
, p
);
3413 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf
);
3415 int vb2_ioctl_dqbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3417 struct video_device
*vdev
= video_devdata(file
);
3419 if (vb2_queue_is_busy(vdev
, file
))
3421 return vb2_dqbuf(vdev
->queue
, p
, file
->f_flags
& O_NONBLOCK
);
3423 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf
);
3425 int vb2_ioctl_streamon(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3427 struct video_device
*vdev
= video_devdata(file
);
3429 if (vb2_queue_is_busy(vdev
, file
))
3431 return vb2_streamon(vdev
->queue
, i
);
3433 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon
);
3435 int vb2_ioctl_streamoff(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3437 struct video_device
*vdev
= video_devdata(file
);
3439 if (vb2_queue_is_busy(vdev
, file
))
3441 return vb2_streamoff(vdev
->queue
, i
);
3443 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff
);
3445 int vb2_ioctl_expbuf(struct file
*file
, void *priv
, struct v4l2_exportbuffer
*p
)
3447 struct video_device
*vdev
= video_devdata(file
);
3449 if (vb2_queue_is_busy(vdev
, file
))
3451 return vb2_expbuf(vdev
->queue
, p
);
3453 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf
);
3455 /* v4l2_file_operations helpers */
3457 int vb2_fop_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3459 struct video_device
*vdev
= video_devdata(file
);
3461 return vb2_mmap(vdev
->queue
, vma
);
3463 EXPORT_SYMBOL_GPL(vb2_fop_mmap
);
3465 int _vb2_fop_release(struct file
*file
, struct mutex
*lock
)
3467 struct video_device
*vdev
= video_devdata(file
);
3471 if (file
->private_data
== vdev
->queue
->owner
) {
3472 vb2_queue_release(vdev
->queue
);
3473 vdev
->queue
->owner
= NULL
;
3477 return v4l2_fh_release(file
);
3479 EXPORT_SYMBOL_GPL(_vb2_fop_release
);
3481 int vb2_fop_release(struct file
*file
)
3483 struct video_device
*vdev
= video_devdata(file
);
3484 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3486 return _vb2_fop_release(file
, lock
);
3488 EXPORT_SYMBOL_GPL(vb2_fop_release
);
3490 ssize_t
vb2_fop_write(struct file
*file
, const char __user
*buf
,
3491 size_t count
, loff_t
*ppos
)
3493 struct video_device
*vdev
= video_devdata(file
);
3494 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3497 if (!(vdev
->queue
->io_modes
& VB2_WRITE
))
3499 if (lock
&& mutex_lock_interruptible(lock
))
3500 return -ERESTARTSYS
;
3501 if (vb2_queue_is_busy(vdev
, file
))
3503 err
= vb2_write(vdev
->queue
, buf
, count
, ppos
,
3504 file
->f_flags
& O_NONBLOCK
);
3505 if (vdev
->queue
->fileio
)
3506 vdev
->queue
->owner
= file
->private_data
;
3512 EXPORT_SYMBOL_GPL(vb2_fop_write
);
3514 ssize_t
vb2_fop_read(struct file
*file
, char __user
*buf
,
3515 size_t count
, loff_t
*ppos
)
3517 struct video_device
*vdev
= video_devdata(file
);
3518 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3521 if (!(vdev
->queue
->io_modes
& VB2_READ
))
3523 if (lock
&& mutex_lock_interruptible(lock
))
3524 return -ERESTARTSYS
;
3525 if (vb2_queue_is_busy(vdev
, file
))
3527 err
= vb2_read(vdev
->queue
, buf
, count
, ppos
,
3528 file
->f_flags
& O_NONBLOCK
);
3529 if (vdev
->queue
->fileio
)
3530 vdev
->queue
->owner
= file
->private_data
;
3536 EXPORT_SYMBOL_GPL(vb2_fop_read
);
3538 unsigned int vb2_fop_poll(struct file
*file
, poll_table
*wait
)
3540 struct video_device
*vdev
= video_devdata(file
);
3541 struct vb2_queue
*q
= vdev
->queue
;
3542 struct mutex
*lock
= q
->lock
? q
->lock
: vdev
->lock
;
3547 * If this helper doesn't know how to lock, then you shouldn't be using
3548 * it but you should write your own.
3552 if (lock
&& mutex_lock_interruptible(lock
))
3557 res
= vb2_poll(vdev
->queue
, file
, wait
);
3559 /* If fileio was started, then we have a new queue owner. */
3560 if (!fileio
&& q
->fileio
)
3561 q
->owner
= file
->private_data
;
3566 EXPORT_SYMBOL_GPL(vb2_fop_poll
);
3569 unsigned long vb2_fop_get_unmapped_area(struct file
*file
, unsigned long addr
,
3570 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
3572 struct video_device
*vdev
= video_devdata(file
);
3574 return vb2_get_unmapped_area(vdev
->queue
, addr
, len
, pgoff
, flags
);
3576 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area
);
3579 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3581 void vb2_ops_wait_prepare(struct vb2_queue
*vq
)
3583 mutex_unlock(vq
->lock
);
3585 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare
);
3587 void vb2_ops_wait_finish(struct vb2_queue
*vq
)
3589 mutex_lock(vq
->lock
);
3591 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish
);
3593 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3594 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3595 MODULE_LICENSE("GPL");