2 * videobuf2-core.c - video buffer 2 core 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/videobuf2-core.h>
29 #include <trace/events/vb2.h>
32 module_param(debug
, int, 0644);
34 #define dprintk(level, fmt, arg...) \
37 pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
40 #ifdef CONFIG_VIDEO_ADV_DEBUG
43 * If advanced debugging is on, then count how often each op is called
44 * successfully, which can either be per-buffer or per-queue.
46 * This makes it easy to check that the 'init' and 'cleanup'
47 * (and variations thereof) stay balanced.
50 #define log_memop(vb, op) \
51 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
52 (vb)->vb2_queue, (vb)->index, #op, \
53 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
55 #define call_memop(vb, op, args...) \
57 struct vb2_queue *_q = (vb)->vb2_queue; \
61 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
63 (vb)->cnt_mem_ ## op++; \
67 #define call_ptr_memop(vb, op, args...) \
69 struct vb2_queue *_q = (vb)->vb2_queue; \
73 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
74 if (!IS_ERR_OR_NULL(ptr)) \
75 (vb)->cnt_mem_ ## op++; \
79 #define call_void_memop(vb, op, args...) \
81 struct vb2_queue *_q = (vb)->vb2_queue; \
84 if (_q->mem_ops->op) \
85 _q->mem_ops->op(args); \
86 (vb)->cnt_mem_ ## op++; \
89 #define log_qop(q, op) \
90 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
91 (q)->ops->op ? "" : " (nop)")
93 #define call_qop(q, op, args...) \
98 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
104 #define call_void_qop(q, op, args...) \
108 (q)->ops->op(args); \
112 #define log_vb_qop(vb, op, args...) \
113 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
114 (vb)->vb2_queue, (vb)->index, #op, \
115 (vb)->vb2_queue->ops->op ? "" : " (nop)")
117 #define call_vb_qop(vb, op, args...) \
121 log_vb_qop(vb, op); \
122 err = (vb)->vb2_queue->ops->op ? \
123 (vb)->vb2_queue->ops->op(args) : 0; \
125 (vb)->cnt_ ## op++; \
129 #define call_void_vb_qop(vb, op, args...) \
131 log_vb_qop(vb, op); \
132 if ((vb)->vb2_queue->ops->op) \
133 (vb)->vb2_queue->ops->op(args); \
134 (vb)->cnt_ ## op++; \
139 #define call_memop(vb, op, args...) \
140 ((vb)->vb2_queue->mem_ops->op ? \
141 (vb)->vb2_queue->mem_ops->op(args) : 0)
143 #define call_ptr_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : NULL)
147 #define call_void_memop(vb, op, args...) \
149 if ((vb)->vb2_queue->mem_ops->op) \
150 (vb)->vb2_queue->mem_ops->op(args); \
153 #define call_qop(q, op, args...) \
154 ((q)->ops->op ? (q)->ops->op(args) : 0)
156 #define call_void_qop(q, op, args...) \
159 (q)->ops->op(args); \
162 #define call_vb_qop(vb, op, args...) \
163 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
165 #define call_void_vb_qop(vb, op, args...) \
167 if ((vb)->vb2_queue->ops->op) \
168 (vb)->vb2_queue->ops->op(args); \
173 #define call_bufop(q, op, args...) \
176 if (q && q->buf_ops && q->buf_ops->op) \
177 ret = q->buf_ops->op(args); \
181 #define call_void_bufop(q, op, args...) \
183 if (q && q->buf_ops && q->buf_ops->op) \
184 q->buf_ops->op(args); \
187 static void __vb2_queue_cancel(struct vb2_queue
*q
);
188 static void __enqueue_in_driver(struct vb2_buffer
*vb
);
191 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
193 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
195 struct vb2_queue
*q
= vb
->vb2_queue
;
196 enum dma_data_direction dma_dir
=
197 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
202 * Allocate memory for all planes in this buffer
203 * NOTE: mmapped areas should be page aligned
205 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
206 unsigned long size
= PAGE_ALIGN(vb
->planes
[plane
].length
);
208 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
209 size
, dma_dir
, q
->gfp_flags
);
210 if (IS_ERR_OR_NULL(mem_priv
))
213 /* Associate allocator private data with this plane */
214 vb
->planes
[plane
].mem_priv
= mem_priv
;
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
, vb
->index
);
243 * __vb2_buf_userptr_put() - release userspace memory associated with
246 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
250 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
251 if (vb
->planes
[plane
].mem_priv
)
252 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
253 vb
->planes
[plane
].mem_priv
= NULL
;
258 * __vb2_plane_dmabuf_put() - release memory associated with
259 * a DMABUF shared plane
261 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
267 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
269 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
270 dma_buf_put(p
->dbuf
);
277 * __vb2_buf_dmabuf_put() - release memory associated with
278 * a DMABUF shared buffer
280 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
284 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
285 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
289 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
292 static void __setup_offsets(struct vb2_buffer
*vb
)
294 struct vb2_queue
*q
= vb
->vb2_queue
;
296 unsigned long off
= 0;
299 struct vb2_buffer
*prev
= q
->bufs
[vb
->index
- 1];
300 struct vb2_plane
*p
= &prev
->planes
[prev
->num_planes
- 1];
302 off
= PAGE_ALIGN(p
->m
.offset
+ p
->length
);
305 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
306 vb
->planes
[plane
].m
.offset
= off
;
308 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
309 vb
->index
, plane
, off
);
311 off
+= vb
->planes
[plane
].length
;
312 off
= PAGE_ALIGN(off
);
317 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
318 * video buffer memory for all buffers/planes on the queue and initializes the
321 * Returns the number of buffers successfully allocated.
323 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum vb2_memory memory
,
324 unsigned int num_buffers
, unsigned int num_planes
,
325 const unsigned plane_sizes
[VB2_MAX_PLANES
])
327 unsigned int buffer
, plane
;
328 struct vb2_buffer
*vb
;
331 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
332 /* Allocate videobuf buffer structures */
333 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
335 dprintk(1, "memory alloc for buffer struct failed\n");
339 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
341 vb
->num_planes
= num_planes
;
342 vb
->index
= q
->num_buffers
+ buffer
;
345 for (plane
= 0; plane
< num_planes
; ++plane
) {
346 vb
->planes
[plane
].length
= plane_sizes
[plane
];
347 vb
->planes
[plane
].min_length
= plane_sizes
[plane
];
349 q
->bufs
[vb
->index
] = vb
;
351 /* Allocate video buffer memory for the MMAP type */
352 if (memory
== VB2_MEMORY_MMAP
) {
353 ret
= __vb2_buf_mem_alloc(vb
);
355 dprintk(1, "failed allocating memory for "
356 "buffer %d\n", buffer
);
357 q
->bufs
[vb
->index
] = NULL
;
363 * Call the driver-provided buffer initialization
364 * callback, if given. An error in initialization
365 * results in queue setup failure.
367 ret
= call_vb_qop(vb
, buf_init
, vb
);
369 dprintk(1, "buffer %d %p initialization"
370 " failed\n", buffer
, vb
);
371 __vb2_buf_mem_free(vb
);
372 q
->bufs
[vb
->index
] = NULL
;
379 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
386 * __vb2_free_mem() - release all video buffer memory for a given queue
388 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
391 struct vb2_buffer
*vb
;
393 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
395 vb
= q
->bufs
[buffer
];
399 /* Free MMAP buffers or release USERPTR buffers */
400 if (q
->memory
== VB2_MEMORY_MMAP
)
401 __vb2_buf_mem_free(vb
);
402 else if (q
->memory
== VB2_MEMORY_DMABUF
)
403 __vb2_buf_dmabuf_put(vb
);
405 __vb2_buf_userptr_put(vb
);
410 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
411 * related information, if no buffers are left return the queue to an
412 * uninitialized state. Might be called even if the queue has already been freed.
414 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
419 * Sanity check: when preparing a buffer the queue lock is released for
420 * a short while (see __buf_prepare for the details), which would allow
421 * a race with a reqbufs which can call this function. Removing the
422 * buffers from underneath __buf_prepare is obviously a bad idea, so we
423 * check if any of the buffers is in the state PREPARING, and if so we
424 * just return -EAGAIN.
426 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
428 if (q
->bufs
[buffer
] == NULL
)
430 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
431 dprintk(1, "preparing buffers, cannot free\n");
436 /* Call driver-provided cleanup function for each buffer, if provided */
437 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
439 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
441 if (vb
&& vb
->planes
[0].mem_priv
)
442 call_void_vb_qop(vb
, buf_cleanup
, vb
);
445 /* Release video buffer memory */
446 __vb2_free_mem(q
, buffers
);
448 #ifdef CONFIG_VIDEO_ADV_DEBUG
450 * Check that all the calls were balances during the life-time of this
451 * queue. If not (or if the debug level is 1 or up), then dump the
452 * counters to the kernel log.
454 if (q
->num_buffers
) {
455 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
456 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
458 if (unbalanced
|| debug
) {
459 pr_info("vb2: counters for queue %p:%s\n", q
,
460 unbalanced
? " UNBALANCED!" : "");
461 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
462 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
463 q
->cnt_stop_streaming
);
464 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
465 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
467 q
->cnt_queue_setup
= 0;
468 q
->cnt_wait_prepare
= 0;
469 q
->cnt_wait_finish
= 0;
470 q
->cnt_start_streaming
= 0;
471 q
->cnt_stop_streaming
= 0;
473 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
474 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
475 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
476 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
477 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
478 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
479 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
480 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
481 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
482 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
484 if (unbalanced
|| debug
) {
485 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
486 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
487 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
488 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
489 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
490 pr_info("vb2: buf_queue: %u buf_done: %u\n",
491 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
492 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
493 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
494 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
496 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
497 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
498 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
499 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
500 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
501 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
502 vb
->cnt_mem_get_dmabuf
,
503 vb
->cnt_mem_num_users
,
510 /* Free videobuf buffers */
511 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
513 kfree(q
->bufs
[buffer
]);
514 q
->bufs
[buffer
] = NULL
;
517 q
->num_buffers
-= buffers
;
518 if (!q
->num_buffers
) {
520 INIT_LIST_HEAD(&q
->queued_list
);
526 * vb2_buffer_in_use() - return true if the buffer is in use and
527 * the queue cannot be freed (by the means of REQBUFS(0)) call
529 bool vb2_buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
532 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
533 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
535 * If num_users() has not been provided, call_memop
536 * will return 0, apparently nobody cares about this
537 * case anyway. If num_users() returns more than 1,
538 * we are not the only user of the plane's memory.
540 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
545 EXPORT_SYMBOL(vb2_buffer_in_use
);
548 * __buffers_in_use() - return true if any buffers on the queue are in use and
549 * the queue cannot be freed (by the means of REQBUFS(0)) call
551 static bool __buffers_in_use(struct vb2_queue
*q
)
554 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
555 if (vb2_buffer_in_use(q
, q
->bufs
[buffer
]))
562 * vb2_core_querybuf() - query video buffer information
564 * @index: id number of the buffer
565 * @pb: buffer struct passed from userspace
567 * Should be called from vidioc_querybuf ioctl handler in driver.
568 * The passed buffer should have been verified.
569 * This function fills the relevant information for the userspace.
571 void vb2_core_querybuf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
573 call_void_bufop(q
, fill_user_buffer
, q
->bufs
[index
], pb
);
575 EXPORT_SYMBOL_GPL(vb2_core_querybuf
);
578 * __verify_userptr_ops() - verify that all memory operations required for
579 * USERPTR queue type have been provided
581 static int __verify_userptr_ops(struct vb2_queue
*q
)
583 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
584 !q
->mem_ops
->put_userptr
)
591 * __verify_mmap_ops() - verify that all memory operations required for
592 * MMAP queue type have been provided
594 static int __verify_mmap_ops(struct vb2_queue
*q
)
596 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
597 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
604 * __verify_dmabuf_ops() - verify that all memory operations required for
605 * DMABUF queue type have been provided
607 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
609 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
610 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
611 !q
->mem_ops
->unmap_dmabuf
)
618 * vb2_verify_memory_type() - Check whether the memory type and buffer type
619 * passed to a buffer operation are compatible with the queue.
621 int vb2_verify_memory_type(struct vb2_queue
*q
,
622 enum vb2_memory memory
, unsigned int type
)
624 if (memory
!= VB2_MEMORY_MMAP
&& memory
!= VB2_MEMORY_USERPTR
&&
625 memory
!= VB2_MEMORY_DMABUF
) {
626 dprintk(1, "unsupported memory type\n");
630 if (type
!= q
->type
) {
631 dprintk(1, "requested type is incorrect\n");
636 * Make sure all the required memory ops for given memory type
639 if (memory
== VB2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
640 dprintk(1, "MMAP for current setup unsupported\n");
644 if (memory
== VB2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
645 dprintk(1, "USERPTR for current setup unsupported\n");
649 if (memory
== VB2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
650 dprintk(1, "DMABUF for current setup unsupported\n");
655 * Place the busy tests at the end: -EBUSY can be ignored when
656 * create_bufs is called with count == 0, but count == 0 should still
657 * do the memory and type validation.
659 if (vb2_fileio_is_active(q
)) {
660 dprintk(1, "file io in progress\n");
665 EXPORT_SYMBOL(vb2_verify_memory_type
);
668 * vb2_core_reqbufs() - Initiate streaming
669 * @q: videobuf2 queue
670 * @memory: memory type
671 * @count: requested buffer count
673 * Should be called from vidioc_reqbufs ioctl handler of a driver.
675 * 1) verifies streaming parameters passed from the userspace,
676 * 2) sets up the queue,
677 * 3) negotiates number of buffers and planes per buffer with the driver
678 * to be used during streaming,
679 * 4) allocates internal buffer structures (struct vb2_buffer), according to
680 * the agreed parameters,
681 * 5) for MMAP memory type, allocates actual video memory, using the
682 * memory handling/allocation routines provided during queue initialization
684 * If req->count is 0, all the memory will be freed instead.
685 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
686 * and the queue is not busy, memory will be reallocated.
688 * The return values from this function are intended to be directly returned
689 * from vidioc_reqbufs handler in driver.
691 int vb2_core_reqbufs(struct vb2_queue
*q
, enum vb2_memory memory
,
694 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
695 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
699 dprintk(1, "streaming active\n");
703 if (*count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= memory
) {
705 * We already have buffers allocated, so first check if they
706 * are not in use and can be freed.
708 mutex_lock(&q
->mmap_lock
);
709 if (q
->memory
== VB2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
710 mutex_unlock(&q
->mmap_lock
);
711 dprintk(1, "memory in use, cannot free\n");
716 * Call queue_cancel to clean up any buffers in the PREPARED or
717 * QUEUED state which is possible if buffers were prepared or
718 * queued without ever calling STREAMON.
720 __vb2_queue_cancel(q
);
721 ret
= __vb2_queue_free(q
, q
->num_buffers
);
722 mutex_unlock(&q
->mmap_lock
);
727 * In case of REQBUFS(0) return immediately without calling
728 * driver's queue_setup() callback and allocating resources.
735 * Make sure the requested values and current defaults are sane.
737 num_buffers
= min_t(unsigned int, *count
, VB2_MAX_FRAME
);
738 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
739 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
743 * Ask the driver how many buffers and planes per buffer it requires.
744 * Driver also sets the size and allocator context for each plane.
746 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
, &num_planes
,
747 plane_sizes
, q
->alloc_ctx
);
751 /* Finally, allocate buffers and video memory */
753 __vb2_queue_alloc(q
, memory
, num_buffers
, num_planes
, plane_sizes
);
754 if (allocated_buffers
== 0) {
755 dprintk(1, "memory allocation failed\n");
760 * There is no point in continuing if we can't allocate the minimum
761 * number of buffers needed by this vb2_queue.
763 if (allocated_buffers
< q
->min_buffers_needed
)
767 * Check if driver can handle the allocated number of buffers.
769 if (!ret
&& allocated_buffers
< num_buffers
) {
770 num_buffers
= allocated_buffers
;
772 * num_planes is set by the previous queue_setup(), but since it
773 * signals to queue_setup() whether it is called from create_bufs()
774 * vs reqbufs() we zero it here to signal that queue_setup() is
775 * called for the reqbufs() case.
779 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
780 &num_planes
, plane_sizes
, q
->alloc_ctx
);
782 if (!ret
&& allocated_buffers
< num_buffers
)
786 * Either the driver has accepted a smaller number of buffers,
787 * or .queue_setup() returned an error
791 mutex_lock(&q
->mmap_lock
);
792 q
->num_buffers
= allocated_buffers
;
796 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
797 * from q->num_buffers.
799 __vb2_queue_free(q
, allocated_buffers
);
800 mutex_unlock(&q
->mmap_lock
);
803 mutex_unlock(&q
->mmap_lock
);
806 * Return the number of successfully allocated buffers
809 *count
= allocated_buffers
;
810 q
->waiting_for_buffers
= !q
->is_output
;
814 EXPORT_SYMBOL_GPL(vb2_core_reqbufs
);
817 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
818 * @q: videobuf2 queue
819 * @memory: memory type
820 * @count: requested buffer count
821 * @parg: parameter passed to device driver
823 * Should be called from vidioc_create_bufs ioctl handler of a driver.
825 * 1) verifies parameter sanity
826 * 2) calls the .queue_setup() queue operation
827 * 3) performs any necessary memory allocations
829 * The return values from this function are intended to be directly returned
830 * from vidioc_create_bufs handler in driver.
832 int vb2_core_create_bufs(struct vb2_queue
*q
, enum vb2_memory memory
,
833 unsigned int *count
, unsigned requested_planes
,
834 const unsigned requested_sizes
[])
836 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
837 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
840 if (q
->num_buffers
== VB2_MAX_FRAME
) {
841 dprintk(1, "maximum number of buffers already allocated\n");
845 if (!q
->num_buffers
) {
846 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
848 q
->waiting_for_buffers
= !q
->is_output
;
851 num_buffers
= min(*count
, VB2_MAX_FRAME
- q
->num_buffers
);
853 if (requested_planes
&& requested_sizes
) {
854 num_planes
= requested_planes
;
855 memcpy(plane_sizes
, requested_sizes
, sizeof(plane_sizes
));
859 * Ask the driver, whether the requested number of buffers, planes per
860 * buffer and their sizes are acceptable
862 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
863 &num_planes
, plane_sizes
, q
->alloc_ctx
);
867 /* Finally, allocate buffers and video memory */
868 allocated_buffers
= __vb2_queue_alloc(q
, memory
, num_buffers
,
869 num_planes
, plane_sizes
);
870 if (allocated_buffers
== 0) {
871 dprintk(1, "memory allocation failed\n");
876 * Check if driver can handle the so far allocated number of buffers.
878 if (allocated_buffers
< num_buffers
) {
879 num_buffers
= allocated_buffers
;
882 * q->num_buffers contains the total number of buffers, that the
883 * queue driver has set up
885 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
886 &num_planes
, plane_sizes
, q
->alloc_ctx
);
888 if (!ret
&& allocated_buffers
< num_buffers
)
892 * Either the driver has accepted a smaller number of buffers,
893 * or .queue_setup() returned an error
897 mutex_lock(&q
->mmap_lock
);
898 q
->num_buffers
+= allocated_buffers
;
902 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
903 * from q->num_buffers.
905 __vb2_queue_free(q
, allocated_buffers
);
906 mutex_unlock(&q
->mmap_lock
);
909 mutex_unlock(&q
->mmap_lock
);
912 * Return the number of successfully allocated buffers
915 *count
= allocated_buffers
;
919 EXPORT_SYMBOL_GPL(vb2_core_create_bufs
);
922 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
923 * @vb: vb2_buffer to which the plane in question belongs to
924 * @plane_no: plane number for which the address is to be returned
926 * This function returns a kernel virtual address of a given plane if
927 * such a mapping exist, NULL otherwise.
929 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
931 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
934 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
937 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
940 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
941 * @vb: vb2_buffer to which the plane in question belongs to
942 * @plane_no: plane number for which the cookie is to be returned
944 * This function returns an allocator specific cookie for a given plane if
945 * available, NULL otherwise. The allocator should provide some simple static
946 * inline function, which would convert this cookie to the allocator specific
947 * type that can be used directly by the driver to access the buffer. This can
948 * be for example physical address, pointer to scatter list or IOMMU mapping.
950 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
952 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
955 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
957 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
960 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
961 * @vb: vb2_buffer returned from the driver
962 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
963 * VB2_BUF_STATE_ERROR if the operation finished with an error or
964 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
965 * If start_streaming fails then it should return buffers with state
966 * VB2_BUF_STATE_QUEUED to put them back into the queue.
968 * This function should be called by the driver after a hardware operation on
969 * a buffer is finished and the buffer may be returned to userspace. The driver
970 * cannot use this buffer anymore until it is queued back to it by videobuf
971 * by the means of buf_queue callback. Only buffers previously queued to the
972 * driver by buf_queue can be passed to this function.
974 * While streaming a buffer can only be returned in state DONE or ERROR.
975 * The start_streaming op can also return them in case the DMA engine cannot
976 * be started for some reason. In that case the buffers should be returned with
979 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
981 struct vb2_queue
*q
= vb
->vb2_queue
;
985 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
988 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
989 state
!= VB2_BUF_STATE_ERROR
&&
990 state
!= VB2_BUF_STATE_QUEUED
&&
991 state
!= VB2_BUF_STATE_REQUEUEING
))
992 state
= VB2_BUF_STATE_ERROR
;
994 #ifdef CONFIG_VIDEO_ADV_DEBUG
996 * Although this is not a callback, it still does have to balance
997 * with the buf_queue op. So update this counter manually.
1001 dprintk(4, "done processing on buffer %d, state: %d\n",
1005 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1006 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1008 spin_lock_irqsave(&q
->done_lock
, flags
);
1009 if (state
== VB2_BUF_STATE_QUEUED
||
1010 state
== VB2_BUF_STATE_REQUEUEING
) {
1011 vb
->state
= VB2_BUF_STATE_QUEUED
;
1013 /* Add the buffer to the done buffers list */
1014 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1017 atomic_dec(&q
->owned_by_drv_count
);
1018 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1020 trace_vb2_buf_done(q
, vb
);
1023 case VB2_BUF_STATE_QUEUED
:
1025 case VB2_BUF_STATE_REQUEUEING
:
1026 if (q
->start_streaming_called
)
1027 __enqueue_in_driver(vb
);
1030 /* Inform any processes that may be waiting for buffers */
1031 wake_up(&q
->done_wq
);
1035 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1038 * vb2_discard_done() - discard all buffers marked as DONE
1039 * @q: videobuf2 queue
1041 * This function is intended to be used with suspend/resume operations. It
1042 * discards all 'done' buffers as they would be too old to be requested after
1045 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1046 * delayed works before calling this function to make sure no buffer will be
1047 * touched by the driver and/or hardware.
1049 void vb2_discard_done(struct vb2_queue
*q
)
1051 struct vb2_buffer
*vb
;
1052 unsigned long flags
;
1054 spin_lock_irqsave(&q
->done_lock
, flags
);
1055 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1056 vb
->state
= VB2_BUF_STATE_ERROR
;
1057 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1059 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1062 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1064 static int __qbuf_mmap(struct vb2_buffer
*vb
, const void *pb
)
1069 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1070 vb
, pb
, vb
->planes
);
1071 return ret
? ret
: call_vb_qop(vb
, buf_prepare
, vb
);
1075 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1077 static int __qbuf_userptr(struct vb2_buffer
*vb
, const void *pb
)
1079 struct vb2_plane planes
[VB2_MAX_PLANES
];
1080 struct vb2_queue
*q
= vb
->vb2_queue
;
1084 enum dma_data_direction dma_dir
=
1085 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1086 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1088 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1089 /* Copy relevant information provided by the userspace */
1091 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1096 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1097 /* Skip the plane if already verified */
1098 if (vb
->planes
[plane
].m
.userptr
&&
1099 vb
->planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1100 && vb
->planes
[plane
].length
== planes
[plane
].length
)
1103 dprintk(3, "userspace address for plane %d changed, "
1104 "reacquiring memory\n", plane
);
1106 /* Check if the provided plane buffer is large enough */
1107 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1108 dprintk(1, "provided buffer size %u is less than "
1109 "setup size %u for plane %d\n",
1110 planes
[plane
].length
,
1111 vb
->planes
[plane
].min_length
,
1117 /* Release previously acquired memory if present */
1118 if (vb
->planes
[plane
].mem_priv
) {
1121 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1123 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1126 vb
->planes
[plane
].mem_priv
= NULL
;
1127 vb
->planes
[plane
].bytesused
= 0;
1128 vb
->planes
[plane
].length
= 0;
1129 vb
->planes
[plane
].m
.userptr
= 0;
1130 vb
->planes
[plane
].data_offset
= 0;
1132 /* Acquire each plane's memory */
1133 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1134 planes
[plane
].m
.userptr
,
1135 planes
[plane
].length
, dma_dir
);
1136 if (IS_ERR_OR_NULL(mem_priv
)) {
1137 dprintk(1, "failed acquiring userspace "
1138 "memory for plane %d\n", plane
);
1139 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1142 vb
->planes
[plane
].mem_priv
= mem_priv
;
1146 * Now that everything is in order, copy relevant information
1147 * provided by userspace.
1149 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1150 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1151 vb
->planes
[plane
].length
= planes
[plane
].length
;
1152 vb
->planes
[plane
].m
.userptr
= planes
[plane
].m
.userptr
;
1153 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1158 * One or more planes changed, so we must call buf_init to do
1159 * the driver-specific initialization on the newly acquired
1160 * buffer, if provided.
1162 ret
= call_vb_qop(vb
, buf_init
, vb
);
1164 dprintk(1, "buffer initialization failed\n");
1169 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1171 dprintk(1, "buffer preparation failed\n");
1172 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1178 /* In case of errors, release planes that were already acquired */
1179 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1180 if (vb
->planes
[plane
].mem_priv
)
1181 call_void_memop(vb
, put_userptr
,
1182 vb
->planes
[plane
].mem_priv
);
1183 vb
->planes
[plane
].mem_priv
= NULL
;
1184 vb
->planes
[plane
].m
.userptr
= 0;
1185 vb
->planes
[plane
].length
= 0;
1192 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1194 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const void *pb
)
1196 struct vb2_plane planes
[VB2_MAX_PLANES
];
1197 struct vb2_queue
*q
= vb
->vb2_queue
;
1201 enum dma_data_direction dma_dir
=
1202 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1203 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1205 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1206 /* Copy relevant information provided by the userspace */
1208 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1213 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1214 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1216 if (IS_ERR_OR_NULL(dbuf
)) {
1217 dprintk(1, "invalid dmabuf fd for plane %d\n",
1223 /* use DMABUF size if length is not provided */
1224 if (planes
[plane
].length
== 0)
1225 planes
[plane
].length
= dbuf
->size
;
1227 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1228 dprintk(1, "invalid dmabuf length for plane %d\n",
1234 /* Skip the plane if already verified */
1235 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1236 vb
->planes
[plane
].length
== planes
[plane
].length
) {
1241 dprintk(1, "buffer for plane %d changed\n", plane
);
1245 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1248 /* Release previously acquired memory if present */
1249 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1250 vb
->planes
[plane
].bytesused
= 0;
1251 vb
->planes
[plane
].length
= 0;
1252 vb
->planes
[plane
].m
.fd
= 0;
1253 vb
->planes
[plane
].data_offset
= 0;
1255 /* Acquire each plane's memory */
1256 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
,
1257 q
->alloc_ctx
[plane
], dbuf
, planes
[plane
].length
,
1259 if (IS_ERR(mem_priv
)) {
1260 dprintk(1, "failed to attach dmabuf\n");
1261 ret
= PTR_ERR(mem_priv
);
1266 vb
->planes
[plane
].dbuf
= dbuf
;
1267 vb
->planes
[plane
].mem_priv
= mem_priv
;
1270 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1271 * really we want to do this just before the DMA, not while queueing
1274 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1275 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1277 dprintk(1, "failed to map dmabuf for plane %d\n",
1281 vb
->planes
[plane
].dbuf_mapped
= 1;
1285 * Now that everything is in order, copy relevant information
1286 * provided by userspace.
1288 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1289 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1290 vb
->planes
[plane
].length
= planes
[plane
].length
;
1291 vb
->planes
[plane
].m
.fd
= planes
[plane
].m
.fd
;
1292 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1297 * Call driver-specific initialization on the newly acquired buffer,
1300 ret
= call_vb_qop(vb
, buf_init
, vb
);
1302 dprintk(1, "buffer initialization failed\n");
1307 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1309 dprintk(1, "buffer preparation failed\n");
1310 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1316 /* In case of errors, release planes that were already acquired */
1317 __vb2_buf_dmabuf_put(vb
);
1323 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1325 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1327 struct vb2_queue
*q
= vb
->vb2_queue
;
1330 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1331 atomic_inc(&q
->owned_by_drv_count
);
1333 trace_vb2_buf_queue(q
, vb
);
1336 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1337 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1339 call_void_vb_qop(vb
, buf_queue
, vb
);
1342 static int __buf_prepare(struct vb2_buffer
*vb
, const void *pb
)
1344 struct vb2_queue
*q
= vb
->vb2_queue
;
1348 dprintk(1, "fatal error occurred on queue\n");
1352 vb
->state
= VB2_BUF_STATE_PREPARING
;
1354 switch (q
->memory
) {
1355 case VB2_MEMORY_MMAP
:
1356 ret
= __qbuf_mmap(vb
, pb
);
1358 case VB2_MEMORY_USERPTR
:
1359 ret
= __qbuf_userptr(vb
, pb
);
1361 case VB2_MEMORY_DMABUF
:
1362 ret
= __qbuf_dmabuf(vb
, pb
);
1365 WARN(1, "Invalid queue type\n");
1370 dprintk(1, "buffer preparation failed: %d\n", ret
);
1371 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1377 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
1379 * @q: videobuf2 queue
1380 * @index: id number of the buffer
1381 * @pb: buffer structure passed from userspace to vidioc_prepare_buf
1384 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1385 * The passed buffer should have been verified.
1386 * This function calls buf_prepare callback in the driver (if provided),
1387 * in which driver-specific buffer initialization can be performed,
1389 * The return values from this function are intended to be directly returned
1390 * from vidioc_prepare_buf handler in driver.
1392 int vb2_core_prepare_buf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
1394 struct vb2_buffer
*vb
;
1397 vb
= q
->bufs
[index
];
1398 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1399 dprintk(1, "invalid buffer state %d\n",
1404 ret
= __buf_prepare(vb
, pb
);
1408 /* Fill buffer information for the userspace */
1409 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1411 dprintk(1, "prepare of buffer %d succeeded\n", vb
->index
);
1415 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf
);
1418 * vb2_start_streaming() - Attempt to start streaming.
1419 * @q: videobuf2 queue
1421 * Attempt to start streaming. When this function is called there must be
1422 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1423 * number of buffers required for the DMA engine to function). If the
1424 * @start_streaming op fails it is supposed to return all the driver-owned
1425 * buffers back to vb2 in state QUEUED. Check if that happened and if
1426 * not warn and reclaim them forcefully.
1428 static int vb2_start_streaming(struct vb2_queue
*q
)
1430 struct vb2_buffer
*vb
;
1434 * If any buffers were queued before streamon,
1435 * we can now pass them to driver for processing.
1437 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1438 __enqueue_in_driver(vb
);
1440 /* Tell the driver to start streaming */
1441 q
->start_streaming_called
= 1;
1442 ret
= call_qop(q
, start_streaming
, q
,
1443 atomic_read(&q
->owned_by_drv_count
));
1447 q
->start_streaming_called
= 0;
1449 dprintk(1, "driver refused to start streaming\n");
1451 * If you see this warning, then the driver isn't cleaning up properly
1452 * after a failed start_streaming(). See the start_streaming()
1453 * documentation in videobuf2-core.h for more information how buffers
1454 * should be returned to vb2 in start_streaming().
1456 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1460 * Forcefully reclaim buffers if the driver did not
1461 * correctly return them to vb2.
1463 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1465 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1466 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1468 /* Must be zero now */
1469 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1472 * If done_list is not empty, then start_streaming() didn't call
1473 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1476 WARN_ON(!list_empty(&q
->done_list
));
1481 * vb2_core_qbuf() - Queue a buffer from userspace
1482 * @q: videobuf2 queue
1483 * @index: id number of the buffer
1484 * @pb: buffer structure passed from userspace to vidioc_qbuf handler
1487 * Should be called from vidioc_qbuf ioctl handler of a driver.
1488 * The passed buffer should have been verified.
1490 * 1) if necessary, calls buf_prepare callback in the driver (if provided), in
1491 * which driver-specific buffer initialization can be performed,
1492 * 2) if streaming is on, queues the buffer in driver by the means of buf_queue
1493 * callback for processing.
1495 * The return values from this function are intended to be directly returned
1496 * from vidioc_qbuf handler in driver.
1498 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
1500 struct vb2_buffer
*vb
;
1503 vb
= q
->bufs
[index
];
1505 switch (vb
->state
) {
1506 case VB2_BUF_STATE_DEQUEUED
:
1507 ret
= __buf_prepare(vb
, pb
);
1511 case VB2_BUF_STATE_PREPARED
:
1513 case VB2_BUF_STATE_PREPARING
:
1514 dprintk(1, "buffer still being prepared\n");
1517 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1522 * Add to the queued buffers list, a buffer will stay on it until
1523 * dequeued in dqbuf.
1525 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1527 q
->waiting_for_buffers
= false;
1528 vb
->state
= VB2_BUF_STATE_QUEUED
;
1531 call_void_bufop(q
, copy_timestamp
, vb
, pb
);
1533 trace_vb2_qbuf(q
, vb
);
1536 * If already streaming, give the buffer to driver for processing.
1537 * If not, the buffer will be given to driver on next streamon.
1539 if (q
->start_streaming_called
)
1540 __enqueue_in_driver(vb
);
1542 /* Fill buffer information for the userspace */
1544 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1547 * If streamon has been called, and we haven't yet called
1548 * start_streaming() since not enough buffers were queued, and
1549 * we now have reached the minimum number of queued buffers,
1550 * then we can finally call start_streaming().
1552 if (q
->streaming
&& !q
->start_streaming_called
&&
1553 q
->queued_count
>= q
->min_buffers_needed
) {
1554 ret
= vb2_start_streaming(q
);
1559 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->index
);
1562 EXPORT_SYMBOL_GPL(vb2_core_qbuf
);
1565 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1568 * Will sleep if required for nonblocking == false.
1570 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1573 * All operations on vb_done_list are performed under done_lock
1574 * spinlock protection. However, buffers may be removed from
1575 * it and returned to userspace only while holding both driver's
1576 * lock and the done_lock spinlock. Thus we can be sure that as
1577 * long as we hold the driver's lock, the list will remain not
1578 * empty if list_empty() check succeeds.
1584 if (!q
->streaming
) {
1585 dprintk(1, "streaming off, will not wait for buffers\n");
1590 dprintk(1, "Queue in error state, will not wait for buffers\n");
1594 if (q
->last_buffer_dequeued
) {
1595 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1599 if (!list_empty(&q
->done_list
)) {
1601 * Found a buffer that we were waiting for.
1607 dprintk(1, "nonblocking and no buffers to dequeue, "
1613 * We are streaming and blocking, wait for another buffer to
1614 * become ready or for streamoff. Driver's lock is released to
1615 * allow streamoff or qbuf to be called while waiting.
1617 call_void_qop(q
, wait_prepare
, q
);
1620 * All locks have been released, it is safe to sleep now.
1622 dprintk(3, "will sleep waiting for buffers\n");
1623 ret
= wait_event_interruptible(q
->done_wq
,
1624 !list_empty(&q
->done_list
) || !q
->streaming
||
1628 * We need to reevaluate both conditions again after reacquiring
1629 * the locks or return an error if one occurred.
1631 call_void_qop(q
, wait_finish
, q
);
1633 dprintk(1, "sleep was interrupted\n");
1641 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1643 * Will sleep if required for nonblocking == false.
1645 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1648 unsigned long flags
;
1652 * Wait for at least one buffer to become available on the done_list.
1654 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
1659 * Driver's lock has been held since we last verified that done_list
1660 * is not empty, so no need for another list_empty(done_list) check.
1662 spin_lock_irqsave(&q
->done_lock
, flags
);
1663 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
1665 * Only remove the buffer from done_list if v4l2_buffer can handle all
1667 * Verifying planes is NOT necessary since it already has been checked
1668 * before the buffer is queued/prepared. So it can never fail.
1670 list_del(&(*vb
)->done_entry
);
1671 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1677 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1678 * @q: videobuf2 queue
1680 * This function will wait until all buffers that have been given to the driver
1681 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1682 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1683 * taken, for example from stop_streaming() callback.
1685 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
1687 if (!q
->streaming
) {
1688 dprintk(1, "streaming off, will not wait for buffers\n");
1692 if (q
->start_streaming_called
)
1693 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
1696 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
1699 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1701 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
1703 struct vb2_queue
*q
= vb
->vb2_queue
;
1706 /* nothing to do if the buffer is already dequeued */
1707 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
1710 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1712 /* unmap DMABUF buffer */
1713 if (q
->memory
== VB2_MEMORY_DMABUF
)
1714 for (i
= 0; i
< vb
->num_planes
; ++i
) {
1715 if (!vb
->planes
[i
].dbuf_mapped
)
1717 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
1718 vb
->planes
[i
].dbuf_mapped
= 0;
1723 * vb2_dqbuf() - Dequeue a buffer to the userspace
1724 * @q: videobuf2 queue
1725 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler
1727 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1728 * buffers ready for dequeuing are present. Normally the driver
1729 * would be passing (file->f_flags & O_NONBLOCK) here
1731 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1732 * The passed buffer should have been verified.
1734 * 1) calls buf_finish callback in the driver (if provided), in which
1735 * driver can perform any additional operations that may be required before
1736 * returning the buffer to userspace, such as cache sync,
1737 * 2) the buffer struct members are filled with relevant information for
1740 * The return values from this function are intended to be directly returned
1741 * from vidioc_dqbuf handler in driver.
1743 int vb2_core_dqbuf(struct vb2_queue
*q
, unsigned int *pindex
, void *pb
,
1746 struct vb2_buffer
*vb
= NULL
;
1749 ret
= __vb2_get_done_vb(q
, &vb
, nonblocking
);
1753 switch (vb
->state
) {
1754 case VB2_BUF_STATE_DONE
:
1755 dprintk(3, "returning done buffer\n");
1757 case VB2_BUF_STATE_ERROR
:
1758 dprintk(3, "returning done buffer with errors\n");
1761 dprintk(1, "invalid buffer state\n");
1765 call_void_vb_qop(vb
, buf_finish
, vb
);
1768 *pindex
= vb
->index
;
1770 /* Fill buffer information for the userspace */
1772 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1774 /* Remove from videobuf queue */
1775 list_del(&vb
->queued_entry
);
1778 trace_vb2_dqbuf(q
, vb
);
1780 /* go back to dequeued state */
1783 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1784 vb
->index
, vb
->state
);
1789 EXPORT_SYMBOL_GPL(vb2_core_dqbuf
);
1792 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1794 * Removes all queued buffers from driver's queue and all buffers queued by
1795 * userspace from videobuf's queue. Returns to state after reqbufs.
1797 static void __vb2_queue_cancel(struct vb2_queue
*q
)
1802 * Tell driver to stop all transactions and release all queued
1805 if (q
->start_streaming_called
)
1806 call_void_qop(q
, stop_streaming
, q
);
1809 * If you see this warning, then the driver isn't cleaning up properly
1810 * in stop_streaming(). See the stop_streaming() documentation in
1811 * videobuf2-core.h for more information how buffers should be returned
1812 * to vb2 in stop_streaming().
1814 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1815 for (i
= 0; i
< q
->num_buffers
; ++i
)
1816 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
1817 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
1818 /* Must be zero now */
1819 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1823 q
->start_streaming_called
= 0;
1824 q
->queued_count
= 0;
1828 * Remove all buffers from videobuf's list...
1830 INIT_LIST_HEAD(&q
->queued_list
);
1832 * ...and done list; userspace will not receive any buffers it
1833 * has not already dequeued before initiating cancel.
1835 INIT_LIST_HEAD(&q
->done_list
);
1836 atomic_set(&q
->owned_by_drv_count
, 0);
1837 wake_up_all(&q
->done_wq
);
1840 * Reinitialize all buffers for next use.
1841 * Make sure to call buf_finish for any queued buffers. Normally
1842 * that's done in dqbuf, but that's not going to happen when we
1843 * cancel the whole queue. Note: this code belongs here, not in
1844 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
1845 * call to __fill_user_buffer() after buf_finish(). That order can't
1846 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1848 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1849 struct vb2_buffer
*vb
= q
->bufs
[i
];
1851 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1852 vb
->state
= VB2_BUF_STATE_PREPARED
;
1853 call_void_vb_qop(vb
, buf_finish
, vb
);
1859 int vb2_core_streamon(struct vb2_queue
*q
, unsigned int type
)
1863 if (type
!= q
->type
) {
1864 dprintk(1, "invalid stream type\n");
1869 dprintk(3, "already streaming\n");
1873 if (!q
->num_buffers
) {
1874 dprintk(1, "no buffers have been allocated\n");
1878 if (q
->num_buffers
< q
->min_buffers_needed
) {
1879 dprintk(1, "need at least %u allocated buffers\n",
1880 q
->min_buffers_needed
);
1885 * Tell driver to start streaming provided sufficient buffers
1888 if (q
->queued_count
>= q
->min_buffers_needed
) {
1889 ret
= vb2_start_streaming(q
);
1891 __vb2_queue_cancel(q
);
1898 dprintk(3, "successful\n");
1901 EXPORT_SYMBOL_GPL(vb2_core_streamon
);
1904 * vb2_queue_error() - signal a fatal error on the queue
1905 * @q: videobuf2 queue
1907 * Flag that a fatal unrecoverable error has occurred and wake up all processes
1908 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
1909 * buffers will return -EIO.
1911 * The error flag will be cleared when cancelling the queue, either from
1912 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
1913 * function before starting the stream, otherwise the error flag will remain set
1914 * until the queue is released when closing the device node.
1916 void vb2_queue_error(struct vb2_queue
*q
)
1920 wake_up_all(&q
->done_wq
);
1922 EXPORT_SYMBOL_GPL(vb2_queue_error
);
1924 int vb2_core_streamoff(struct vb2_queue
*q
, unsigned int type
)
1926 if (type
!= q
->type
) {
1927 dprintk(1, "invalid stream type\n");
1932 * Cancel will pause streaming and remove all buffers from the driver
1933 * and videobuf, effectively returning control over them to userspace.
1935 * Note that we do this even if q->streaming == 0: if you prepare or
1936 * queue buffers, and then call streamoff without ever having called
1937 * streamon, you would still expect those buffers to be returned to
1938 * their normal dequeued state.
1940 __vb2_queue_cancel(q
);
1941 q
->waiting_for_buffers
= !q
->is_output
;
1942 q
->last_buffer_dequeued
= false;
1944 dprintk(3, "successful\n");
1947 EXPORT_SYMBOL_GPL(vb2_core_streamoff
);
1950 * __find_plane_by_offset() - find plane associated with the given offset off
1952 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
1953 unsigned int *_buffer
, unsigned int *_plane
)
1955 struct vb2_buffer
*vb
;
1956 unsigned int buffer
, plane
;
1959 * Go over all buffers and their planes, comparing the given offset
1960 * with an offset assigned to each plane. If a match is found,
1961 * return its buffer and plane numbers.
1963 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
1964 vb
= q
->bufs
[buffer
];
1966 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1967 if (vb
->planes
[plane
].m
.offset
== off
) {
1979 * vb2_core_expbuf() - Export a buffer as a file descriptor
1980 * @q: videobuf2 queue
1981 * @fd: file descriptor associated with DMABUF (set by driver) *
1982 * @type: buffer type
1983 * @index: id number of the buffer
1984 * @plane: index of the plane to be exported, 0 for single plane queues
1985 * @flags: flags for newly created file, currently only O_CLOEXEC is
1986 * supported, refer to manual of open syscall for more details
1988 * The return values from this function are intended to be directly returned
1989 * from vidioc_expbuf handler in driver.
1991 int vb2_core_expbuf(struct vb2_queue
*q
, int *fd
, unsigned int type
,
1992 unsigned int index
, unsigned int plane
, unsigned int flags
)
1994 struct vb2_buffer
*vb
= NULL
;
1995 struct vb2_plane
*vb_plane
;
1997 struct dma_buf
*dbuf
;
1999 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2000 dprintk(1, "queue is not currently set up for mmap\n");
2004 if (!q
->mem_ops
->get_dmabuf
) {
2005 dprintk(1, "queue does not support DMA buffer exporting\n");
2009 if (flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2010 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2014 if (type
!= q
->type
) {
2015 dprintk(1, "invalid buffer type\n");
2019 if (index
>= q
->num_buffers
) {
2020 dprintk(1, "buffer index out of range\n");
2024 vb
= q
->bufs
[index
];
2026 if (plane
>= vb
->num_planes
) {
2027 dprintk(1, "buffer plane out of range\n");
2031 if (vb2_fileio_is_active(q
)) {
2032 dprintk(1, "expbuf: file io in progress\n");
2036 vb_plane
= &vb
->planes
[plane
];
2038 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
,
2040 if (IS_ERR_OR_NULL(dbuf
)) {
2041 dprintk(1, "failed to export buffer %d, plane %d\n",
2046 ret
= dma_buf_fd(dbuf
, flags
& ~O_ACCMODE
);
2048 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2054 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2060 EXPORT_SYMBOL_GPL(vb2_core_expbuf
);
2063 * vb2_mmap() - map video buffers into application address space
2064 * @q: videobuf2 queue
2065 * @vma: vma passed to the mmap file operation handler in the driver
2067 * Should be called from mmap file operation handler of a driver.
2068 * This function maps one plane of one of the available video buffers to
2069 * userspace. To map whole video memory allocated on reqbufs, this function
2070 * has to be called once per each plane per each buffer previously allocated.
2072 * When the userspace application calls mmap, it passes to it an offset returned
2073 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2074 * a "cookie", which is then used to identify the plane to be mapped.
2075 * This function finds a plane with a matching offset and a mapping is performed
2076 * by the means of a provided memory operation.
2078 * The return values from this function are intended to be directly returned
2079 * from the mmap handler in driver.
2081 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2083 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2084 struct vb2_buffer
*vb
;
2085 unsigned int buffer
= 0, plane
= 0;
2087 unsigned long length
;
2089 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2090 dprintk(1, "queue is not currently set up for mmap\n");
2095 * Check memory area access mode.
2097 if (!(vma
->vm_flags
& VM_SHARED
)) {
2098 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2102 if (!(vma
->vm_flags
& VM_WRITE
)) {
2103 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2107 if (!(vma
->vm_flags
& VM_READ
)) {
2108 dprintk(1, "invalid vma flags, VM_READ needed\n");
2112 if (vb2_fileio_is_active(q
)) {
2113 dprintk(1, "mmap: file io in progress\n");
2118 * Find the plane corresponding to the offset passed by userspace.
2120 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2124 vb
= q
->bufs
[buffer
];
2127 * MMAP requires page_aligned buffers.
2128 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2129 * so, we need to do the same here.
2131 length
= PAGE_ALIGN(vb
->planes
[plane
].length
);
2132 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2134 "MMAP invalid, as it would overflow buffer length\n");
2138 mutex_lock(&q
->mmap_lock
);
2139 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2140 mutex_unlock(&q
->mmap_lock
);
2144 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2147 EXPORT_SYMBOL_GPL(vb2_mmap
);
2150 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2153 unsigned long pgoff
,
2154 unsigned long flags
)
2156 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2157 struct vb2_buffer
*vb
;
2158 unsigned int buffer
, plane
;
2162 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2163 dprintk(1, "queue is not currently set up for mmap\n");
2168 * Find the plane corresponding to the offset passed by userspace.
2170 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2174 vb
= q
->bufs
[buffer
];
2176 vaddr
= vb2_plane_vaddr(vb
, plane
);
2177 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2179 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2183 * vb2_core_queue_init() - initialize a videobuf2 queue
2184 * @q: videobuf2 queue; this structure should be allocated in driver
2186 * The vb2_queue structure should be allocated by the driver. The driver is
2187 * responsible of clearing it's content and setting initial values for some
2188 * required entries before calling this function.
2189 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2190 * to the struct vb2_queue description in include/media/videobuf2-core.h
2191 * for more information.
2193 int vb2_core_queue_init(struct vb2_queue
*q
)
2200 WARN_ON(!q
->mem_ops
) ||
2201 WARN_ON(!q
->type
) ||
2202 WARN_ON(!q
->io_modes
) ||
2203 WARN_ON(!q
->ops
->queue_setup
) ||
2204 WARN_ON(!q
->ops
->buf_queue
))
2207 INIT_LIST_HEAD(&q
->queued_list
);
2208 INIT_LIST_HEAD(&q
->done_list
);
2209 spin_lock_init(&q
->done_lock
);
2210 mutex_init(&q
->mmap_lock
);
2211 init_waitqueue_head(&q
->done_wq
);
2213 if (q
->buf_struct_size
== 0)
2214 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2218 EXPORT_SYMBOL_GPL(vb2_core_queue_init
);
2220 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2221 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2223 * vb2_core_queue_release() - stop streaming, release the queue and free memory
2224 * @q: videobuf2 queue
2226 * This function stops streaming and performs necessary clean ups, including
2227 * freeing video buffer memory. The driver is responsible for freeing
2228 * the vb2_queue structure itself.
2230 void vb2_core_queue_release(struct vb2_queue
*q
)
2232 __vb2_cleanup_fileio(q
);
2233 __vb2_queue_cancel(q
);
2234 mutex_lock(&q
->mmap_lock
);
2235 __vb2_queue_free(q
, q
->num_buffers
);
2236 mutex_unlock(&q
->mmap_lock
);
2238 EXPORT_SYMBOL_GPL(vb2_core_queue_release
);
2241 * vb2_core_poll() - implements poll userspace operation
2242 * @q: videobuf2 queue
2243 * @file: file argument passed to the poll file operation handler
2244 * @wait: wait argument passed to the poll file operation handler
2246 * This function implements poll file operation handler for a driver.
2247 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2248 * be informed that the file descriptor of a video device is available for
2250 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2251 * will be reported as available for writing.
2253 * The return values from this function are intended to be directly returned
2254 * from poll handler in driver.
2256 unsigned int vb2_core_poll(struct vb2_queue
*q
, struct file
*file
,
2259 unsigned long req_events
= poll_requested_events(wait
);
2260 struct vb2_buffer
*vb
= NULL
;
2261 unsigned long flags
;
2263 if (!q
->is_output
&& !(req_events
& (POLLIN
| POLLRDNORM
)))
2265 if (q
->is_output
&& !(req_events
& (POLLOUT
| POLLWRNORM
)))
2269 * Start file I/O emulator only if streaming API has not been used yet.
2271 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2272 if (!q
->is_output
&& (q
->io_modes
& VB2_READ
) &&
2273 (req_events
& (POLLIN
| POLLRDNORM
))) {
2274 if (__vb2_init_fileio(q
, 1))
2277 if (q
->is_output
&& (q
->io_modes
& VB2_WRITE
) &&
2278 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2279 if (__vb2_init_fileio(q
, 0))
2282 * Write to OUTPUT queue can be done immediately.
2284 return POLLOUT
| POLLWRNORM
;
2289 * There is nothing to wait for if the queue isn't streaming, or if the
2290 * error flag is set.
2292 if (!vb2_is_streaming(q
) || q
->error
)
2296 * For output streams you can call write() as long as there are fewer
2297 * buffers queued than there are buffers available.
2299 if (q
->is_output
&& q
->fileio
&& q
->queued_count
< q
->num_buffers
)
2300 return POLLOUT
| POLLWRNORM
;
2302 if (list_empty(&q
->done_list
)) {
2304 * If the last buffer was dequeued from a capture queue,
2305 * return immediately. DQBUF will return -EPIPE.
2307 if (q
->last_buffer_dequeued
)
2308 return POLLIN
| POLLRDNORM
;
2310 poll_wait(file
, &q
->done_wq
, wait
);
2314 * Take first buffer available for dequeuing.
2316 spin_lock_irqsave(&q
->done_lock
, flags
);
2317 if (!list_empty(&q
->done_list
))
2318 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2320 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2322 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2323 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2324 return (q
->is_output
) ?
2325 POLLOUT
| POLLWRNORM
:
2326 POLLIN
| POLLRDNORM
;
2330 EXPORT_SYMBOL_GPL(vb2_core_poll
);
2333 * struct vb2_fileio_buf - buffer context used by file io emulator
2335 * vb2 provides a compatibility layer and emulator of file io (read and
2336 * write) calls on top of streaming API. This structure is used for
2337 * tracking context related to the buffers.
2339 struct vb2_fileio_buf
{
2343 unsigned int queued
:1;
2347 * struct vb2_fileio_data - queue context used by file io emulator
2349 * @cur_index: the index of the buffer currently being read from or
2350 * written to. If equal to q->num_buffers then a new buffer
2352 * @initial_index: in the read() case all buffers are queued up immediately
2353 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2354 * buffers. However, in the write() case no buffers are initially
2355 * queued, instead whenever a buffer is full it is queued up by
2356 * __vb2_perform_fileio(). Only once all available buffers have
2357 * been queued up will __vb2_perform_fileio() start to dequeue
2358 * buffers. This means that initially __vb2_perform_fileio()
2359 * needs to know what buffer index to use when it is queuing up
2360 * the buffers for the first time. That initial index is stored
2361 * in this field. Once it is equal to q->num_buffers all
2362 * available buffers have been queued and __vb2_perform_fileio()
2363 * should start the normal dequeue/queue cycle.
2365 * vb2 provides a compatibility layer and emulator of file io (read and
2366 * write) calls on top of streaming API. For proper operation it required
2367 * this structure to save the driver state between each call of the read
2368 * or write function.
2370 struct vb2_fileio_data
{
2373 unsigned int memory
;
2374 struct vb2_fileio_buf bufs
[VB2_MAX_FRAME
];
2375 unsigned int cur_index
;
2376 unsigned int initial_index
;
2377 unsigned int q_count
;
2378 unsigned int dq_count
;
2379 unsigned read_once
:1;
2380 unsigned write_immediately
:1;
2384 * __vb2_init_fileio() - initialize file io emulator
2385 * @q: videobuf2 queue
2386 * @read: mode selector (1 means read, 0 means write)
2388 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2390 struct vb2_fileio_data
*fileio
;
2392 unsigned int count
= 0;
2397 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2398 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2402 * Check if device supports mapping buffers to kernel virtual space.
2404 if (!q
->mem_ops
->vaddr
)
2408 * Check if streaming api has not been already activated.
2410 if (q
->streaming
|| q
->num_buffers
> 0)
2414 * Start with count 1, driver can increase it in queue_setup()
2418 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2419 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2420 q
->fileio_write_immediately
);
2422 fileio
= kzalloc(sizeof(*fileio
), GFP_KERNEL
);
2426 fileio
->read_once
= q
->fileio_read_once
;
2427 fileio
->write_immediately
= q
->fileio_write_immediately
;
2430 * Request buffers and use MMAP type to force driver
2431 * to allocate buffers by itself.
2433 fileio
->count
= count
;
2434 fileio
->memory
= VB2_MEMORY_MMAP
;
2435 fileio
->type
= q
->type
;
2437 ret
= vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2442 * Check if plane_count is correct
2443 * (multiplane buffers are not supported).
2445 if (q
->bufs
[0]->num_planes
!= 1) {
2451 * Get kernel address of each buffer.
2453 for (i
= 0; i
< q
->num_buffers
; i
++) {
2454 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2455 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2459 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2463 * Read mode requires pre queuing of all buffers.
2467 * Queue all buffers.
2469 for (i
= 0; i
< q
->num_buffers
; i
++) {
2470 ret
= vb2_core_qbuf(q
, i
, NULL
);
2473 fileio
->bufs
[i
].queued
= 1;
2476 * All buffers have been queued, so mark that by setting
2477 * initial_index to q->num_buffers
2479 fileio
->initial_index
= q
->num_buffers
;
2480 fileio
->cur_index
= q
->num_buffers
;
2486 ret
= vb2_core_streamon(q
, q
->type
);
2494 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2503 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2504 * @q: videobuf2 queue
2506 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2508 struct vb2_fileio_data
*fileio
= q
->fileio
;
2511 vb2_core_streamoff(q
, q
->type
);
2514 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2516 dprintk(3, "file io emulator closed\n");
2522 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2523 * @q: videobuf2 queue
2524 * @data: pointed to target userspace buffer
2525 * @count: number of bytes to read or write
2526 * @ppos: file handle position tracking pointer
2527 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2528 * @read: access mode selector (1 means read, 0 means write)
2530 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2531 loff_t
*ppos
, int nonblock
, int read
)
2533 struct vb2_fileio_data
*fileio
;
2534 struct vb2_fileio_buf
*buf
;
2535 bool is_multiplanar
= q
->is_multiplanar
;
2537 * When using write() to write data to an output video node the vb2 core
2538 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2539 * else is able to provide this information with the write() operation.
2541 bool copy_timestamp
= !read
&& q
->copy_timestamp
;
2545 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2546 read
? "read" : "write", (long)*ppos
, count
,
2547 nonblock
? "non" : "");
2553 * Initialize emulator on first call.
2555 if (!vb2_fileio_is_active(q
)) {
2556 ret
= __vb2_init_fileio(q
, read
);
2557 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
2564 * Check if we need to dequeue the buffer.
2566 index
= fileio
->cur_index
;
2567 if (index
>= q
->num_buffers
) {
2568 struct vb2_buffer
*b
;
2571 * Call vb2_dqbuf to get buffer back.
2573 ret
= vb2_core_dqbuf(q
, &index
, NULL
, nonblock
);
2574 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
2577 fileio
->dq_count
+= 1;
2579 fileio
->cur_index
= index
;
2580 buf
= &fileio
->bufs
[index
];
2584 * Get number of bytes filled by the driver
2588 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
2589 : vb2_plane_size(q
->bufs
[index
], 0);
2590 /* Compensate for data_offset on read in the multiplanar case. */
2591 if (is_multiplanar
&& read
&&
2592 b
->planes
[0].data_offset
< buf
->size
) {
2593 buf
->pos
= b
->planes
[0].data_offset
;
2594 buf
->size
-= buf
->pos
;
2597 buf
= &fileio
->bufs
[index
];
2601 * Limit count on last few bytes of the buffer.
2603 if (buf
->pos
+ count
> buf
->size
) {
2604 count
= buf
->size
- buf
->pos
;
2605 dprintk(5, "reducing read count: %zd\n", count
);
2609 * Transfer data to userspace.
2611 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2612 count
, index
, buf
->pos
);
2614 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
2616 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
2618 dprintk(3, "error copying data\n");
2629 * Queue next buffer if required.
2631 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
2632 struct vb2_buffer
*b
= q
->bufs
[index
];
2635 * Check if this is the last buffer to read.
2637 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
2638 dprintk(3, "read limit reached\n");
2639 return __vb2_cleanup_fileio(q
);
2643 * Call vb2_qbuf and give buffer to the driver.
2645 b
->planes
[0].bytesused
= buf
->pos
;
2648 b
->timestamp
= ktime_get_ns();
2649 ret
= vb2_core_qbuf(q
, index
, NULL
);
2650 dprintk(5, "vb2_dbuf result: %d\n", ret
);
2655 * Buffer has been queued, update the status
2659 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
2660 fileio
->q_count
+= 1;
2662 * If we are queuing up buffers for the first time, then
2663 * increase initial_index by one.
2665 if (fileio
->initial_index
< q
->num_buffers
)
2666 fileio
->initial_index
++;
2668 * The next buffer to use is either a buffer that's going to be
2669 * queued for the first time (initial_index < q->num_buffers)
2670 * or it is equal to q->num_buffers, meaning that the next
2671 * time we need to dequeue a buffer since we've now queued up
2672 * all the 'first time' buffers.
2674 fileio
->cur_index
= fileio
->initial_index
;
2678 * Return proper number of bytes processed.
2685 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2686 loff_t
*ppos
, int nonblocking
)
2688 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
2690 EXPORT_SYMBOL_GPL(vb2_read
);
2692 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
2693 loff_t
*ppos
, int nonblocking
)
2695 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
2696 ppos
, nonblocking
, 0);
2698 EXPORT_SYMBOL_GPL(vb2_write
);
2700 struct vb2_threadio_data
{
2701 struct task_struct
*thread
;
2707 static int vb2_thread(void *data
)
2709 struct vb2_queue
*q
= data
;
2710 struct vb2_threadio_data
*threadio
= q
->threadio
;
2711 bool copy_timestamp
= false;
2712 unsigned prequeue
= 0;
2717 prequeue
= q
->num_buffers
;
2718 copy_timestamp
= q
->copy_timestamp
;
2724 struct vb2_buffer
*vb
;
2727 * Call vb2_dqbuf to get buffer back.
2730 vb
= q
->bufs
[index
++];
2733 call_void_qop(q
, wait_finish
, q
);
2734 if (!threadio
->stop
)
2735 ret
= vb2_core_dqbuf(q
, &index
, NULL
, 0);
2736 call_void_qop(q
, wait_prepare
, q
);
2737 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
2739 vb
= q
->bufs
[index
];
2741 if (ret
|| threadio
->stop
)
2745 if (vb
->state
!= VB2_BUF_STATE_ERROR
)
2746 if (threadio
->fnc(vb
, threadio
->priv
))
2748 call_void_qop(q
, wait_finish
, q
);
2750 vb
->timestamp
= ktime_get_ns();;
2751 if (!threadio
->stop
)
2752 ret
= vb2_core_qbuf(q
, vb
->index
, NULL
);
2753 call_void_qop(q
, wait_prepare
, q
);
2754 if (ret
|| threadio
->stop
)
2758 /* Hmm, linux becomes *very* unhappy without this ... */
2759 while (!kthread_should_stop()) {
2760 set_current_state(TASK_INTERRUPTIBLE
);
2767 * This function should not be used for anything else but the videobuf2-dvb
2768 * support. If you think you have another good use-case for this, then please
2769 * contact the linux-media mailinglist first.
2771 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
2772 const char *thread_name
)
2774 struct vb2_threadio_data
*threadio
;
2781 if (WARN_ON(q
->fileio
))
2784 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
2785 if (threadio
== NULL
)
2787 threadio
->fnc
= fnc
;
2788 threadio
->priv
= priv
;
2790 ret
= __vb2_init_fileio(q
, !q
->is_output
);
2791 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
2794 q
->threadio
= threadio
;
2795 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
2796 if (IS_ERR(threadio
->thread
)) {
2797 ret
= PTR_ERR(threadio
->thread
);
2798 threadio
->thread
= NULL
;
2804 __vb2_cleanup_fileio(q
);
2809 EXPORT_SYMBOL_GPL(vb2_thread_start
);
2811 int vb2_thread_stop(struct vb2_queue
*q
)
2813 struct vb2_threadio_data
*threadio
= q
->threadio
;
2816 if (threadio
== NULL
)
2818 threadio
->stop
= true;
2819 /* Wake up all pending sleeps in the thread */
2821 err
= kthread_stop(threadio
->thread
);
2822 __vb2_cleanup_fileio(q
);
2823 threadio
->thread
= NULL
;
2828 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
2830 MODULE_DESCRIPTION("Media buffer core framework");
2831 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2832 MODULE_LICENSE("GPL");