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>
28 #include <media/v4l2-mc.h>
30 #include <trace/events/vb2.h>
33 module_param(debug, int, 0644);
35 #define dprintk(level, fmt, arg...) \
38 pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
41 #ifdef CONFIG_VIDEO_ADV_DEBUG
44 * If advanced debugging is on, then count how often each op is called
45 * successfully, which can either be per-buffer or per-queue.
47 * This makes it easy to check that the 'init' and 'cleanup'
48 * (and variations thereof) stay balanced.
51 #define log_memop(vb, op) \
52 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
53 (vb)->vb2_queue, (vb)->index, #op, \
54 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
56 #define call_memop(vb, op, args...) \
58 struct vb2_queue *_q = (vb)->vb2_queue; \
62 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
64 (vb)->cnt_mem_ ## op++; \
68 #define call_ptr_memop(vb, op, args...) \
70 struct vb2_queue *_q = (vb)->vb2_queue; \
74 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
75 if (!IS_ERR_OR_NULL(ptr)) \
76 (vb)->cnt_mem_ ## op++; \
80 #define call_void_memop(vb, op, args...) \
82 struct vb2_queue *_q = (vb)->vb2_queue; \
85 if (_q->mem_ops->op) \
86 _q->mem_ops->op(args); \
87 (vb)->cnt_mem_ ## op++; \
90 #define log_qop(q, op) \
91 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
92 (q)->ops->op ? "" : " (nop)")
94 #define call_qop(q, op, args...) \
99 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
105 #define call_void_qop(q, op, args...) \
109 (q)->ops->op(args); \
113 #define log_vb_qop(vb, op, args...) \
114 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
115 (vb)->vb2_queue, (vb)->index, #op, \
116 (vb)->vb2_queue->ops->op ? "" : " (nop)")
118 #define call_vb_qop(vb, op, args...) \
122 log_vb_qop(vb, op); \
123 err = (vb)->vb2_queue->ops->op ? \
124 (vb)->vb2_queue->ops->op(args) : 0; \
126 (vb)->cnt_ ## op++; \
130 #define call_void_vb_qop(vb, op, args...) \
132 log_vb_qop(vb, op); \
133 if ((vb)->vb2_queue->ops->op) \
134 (vb)->vb2_queue->ops->op(args); \
135 (vb)->cnt_ ## op++; \
140 #define call_memop(vb, op, args...) \
141 ((vb)->vb2_queue->mem_ops->op ? \
142 (vb)->vb2_queue->mem_ops->op(args) : 0)
144 #define call_ptr_memop(vb, op, args...) \
145 ((vb)->vb2_queue->mem_ops->op ? \
146 (vb)->vb2_queue->mem_ops->op(args) : NULL)
148 #define call_void_memop(vb, op, args...) \
150 if ((vb)->vb2_queue->mem_ops->op) \
151 (vb)->vb2_queue->mem_ops->op(args); \
154 #define call_qop(q, op, args...) \
155 ((q)->ops->op ? (q)->ops->op(args) : 0)
157 #define call_void_qop(q, op, args...) \
160 (q)->ops->op(args); \
163 #define call_vb_qop(vb, op, args...) \
164 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
166 #define call_void_vb_qop(vb, op, args...) \
168 if ((vb)->vb2_queue->ops->op) \
169 (vb)->vb2_queue->ops->op(args); \
174 #define call_bufop(q, op, args...) \
177 if (q && q->buf_ops && q->buf_ops->op) \
178 ret = q->buf_ops->op(args); \
182 #define call_void_bufop(q, op, args...) \
184 if (q && q->buf_ops && q->buf_ops->op) \
185 q->buf_ops->op(args); \
188 static void __vb2_queue_cancel(struct vb2_queue *q);
189 static void __enqueue_in_driver(struct vb2_buffer *vb);
192 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
194 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
196 struct vb2_queue *q = vb->vb2_queue;
197 enum dma_data_direction dma_dir =
198 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
203 * Allocate memory for all planes in this buffer
204 * NOTE: mmapped areas should be page aligned
206 for (plane = 0; plane < vb->num_planes; ++plane) {
207 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
209 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
210 size, dma_dir, q->gfp_flags);
211 if (IS_ERR_OR_NULL(mem_priv))
214 /* Associate allocator private data with this plane */
215 vb->planes[plane].mem_priv = mem_priv;
220 /* Free already allocated memory if one of the allocations failed */
221 for (; plane > 0; --plane) {
222 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
223 vb->planes[plane - 1].mem_priv = NULL;
230 * __vb2_buf_mem_free() - free memory of the given buffer
232 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
236 for (plane = 0; plane < vb->num_planes; ++plane) {
237 call_void_memop(vb, put, vb->planes[plane].mem_priv);
238 vb->planes[plane].mem_priv = NULL;
239 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
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);
278 * __vb2_buf_dmabuf_put() - release memory associated with
279 * a DMABUF shared buffer
281 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
285 for (plane = 0; plane < vb->num_planes; ++plane)
286 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
290 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
293 static void __setup_offsets(struct vb2_buffer *vb)
295 struct vb2_queue *q = vb->vb2_queue;
297 unsigned long off = 0;
300 struct vb2_buffer *prev = q->bufs[vb->index - 1];
301 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
303 off = PAGE_ALIGN(p->m.offset + p->length);
306 for (plane = 0; plane < vb->num_planes; ++plane) {
307 vb->planes[plane].m.offset = off;
309 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
310 vb->index, plane, off);
312 off += vb->planes[plane].length;
313 off = PAGE_ALIGN(off);
318 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
319 * video buffer memory for all buffers/planes on the queue and initializes the
322 * Returns the number of buffers successfully allocated.
324 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
325 unsigned int num_buffers, unsigned int num_planes,
326 const unsigned plane_sizes[VB2_MAX_PLANES])
328 unsigned int buffer, plane;
329 struct vb2_buffer *vb;
332 for (buffer = 0; buffer < num_buffers; ++buffer) {
333 /* Allocate videobuf buffer structures */
334 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
336 dprintk(1, "memory alloc for buffer struct failed\n");
340 vb->state = VB2_BUF_STATE_DEQUEUED;
342 vb->num_planes = num_planes;
343 vb->index = q->num_buffers + buffer;
346 for (plane = 0; plane < num_planes; ++plane) {
347 vb->planes[plane].length = plane_sizes[plane];
348 vb->planes[plane].min_length = plane_sizes[plane];
350 q->bufs[vb->index] = vb;
352 /* Allocate video buffer memory for the MMAP type */
353 if (memory == VB2_MEMORY_MMAP) {
354 ret = __vb2_buf_mem_alloc(vb);
356 dprintk(1, "failed allocating memory for "
357 "buffer %d\n", buffer);
358 q->bufs[vb->index] = NULL;
364 * Call the driver-provided buffer initialization
365 * callback, if given. An error in initialization
366 * results in queue setup failure.
368 ret = call_vb_qop(vb, buf_init, vb);
370 dprintk(1, "buffer %d %p initialization"
371 " failed\n", buffer, vb);
372 __vb2_buf_mem_free(vb);
373 q->bufs[vb->index] = NULL;
380 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
387 * __vb2_free_mem() - release all video buffer memory for a given queue
389 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
392 struct vb2_buffer *vb;
394 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
396 vb = q->bufs[buffer];
400 /* Free MMAP buffers or release USERPTR buffers */
401 if (q->memory == VB2_MEMORY_MMAP)
402 __vb2_buf_mem_free(vb);
403 else if (q->memory == VB2_MEMORY_DMABUF)
404 __vb2_buf_dmabuf_put(vb);
406 __vb2_buf_userptr_put(vb);
411 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
412 * related information, if no buffers are left return the queue to an
413 * uninitialized state. Might be called even if the queue has already been freed.
415 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
420 * Sanity check: when preparing a buffer the queue lock is released for
421 * a short while (see __buf_prepare for the details), which would allow
422 * a race with a reqbufs which can call this function. Removing the
423 * buffers from underneath __buf_prepare is obviously a bad idea, so we
424 * check if any of the buffers is in the state PREPARING, and if so we
425 * just return -EAGAIN.
427 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
429 if (q->bufs[buffer] == NULL)
431 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
432 dprintk(1, "preparing buffers, cannot free\n");
437 /* Call driver-provided cleanup function for each buffer, if provided */
438 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
440 struct vb2_buffer *vb = q->bufs[buffer];
442 if (vb && vb->planes[0].mem_priv)
443 call_void_vb_qop(vb, buf_cleanup, vb);
446 /* Release video buffer memory */
447 __vb2_free_mem(q, buffers);
449 #ifdef CONFIG_VIDEO_ADV_DEBUG
451 * Check that all the calls were balances during the life-time of this
452 * queue. If not (or if the debug level is 1 or up), then dump the
453 * counters to the kernel log.
455 if (q->num_buffers) {
456 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
457 q->cnt_wait_prepare != q->cnt_wait_finish;
459 if (unbalanced || debug) {
460 pr_info("vb2: counters for queue %p:%s\n", q,
461 unbalanced ? " UNBALANCED!" : "");
462 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
463 q->cnt_queue_setup, q->cnt_start_streaming,
464 q->cnt_stop_streaming);
465 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
466 q->cnt_wait_prepare, q->cnt_wait_finish);
468 q->cnt_queue_setup = 0;
469 q->cnt_wait_prepare = 0;
470 q->cnt_wait_finish = 0;
471 q->cnt_start_streaming = 0;
472 q->cnt_stop_streaming = 0;
474 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
475 struct vb2_buffer *vb = q->bufs[buffer];
476 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
477 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
478 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
479 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
480 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
481 vb->cnt_buf_queue != vb->cnt_buf_done ||
482 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
483 vb->cnt_buf_init != vb->cnt_buf_cleanup;
485 if (unbalanced || debug) {
486 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
487 q, buffer, unbalanced ? " UNBALANCED!" : "");
488 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
489 vb->cnt_buf_init, vb->cnt_buf_cleanup,
490 vb->cnt_buf_prepare, vb->cnt_buf_finish);
491 pr_info("vb2: buf_queue: %u buf_done: %u\n",
492 vb->cnt_buf_queue, vb->cnt_buf_done);
493 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
494 vb->cnt_mem_alloc, vb->cnt_mem_put,
495 vb->cnt_mem_prepare, vb->cnt_mem_finish,
497 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
498 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
499 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
500 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
501 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
502 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
503 vb->cnt_mem_get_dmabuf,
504 vb->cnt_mem_num_users,
511 /* Free videobuf buffers */
512 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
514 kfree(q->bufs[buffer]);
515 q->bufs[buffer] = NULL;
518 q->num_buffers -= buffers;
519 if (!q->num_buffers) {
521 INIT_LIST_HEAD(&q->queued_list);
527 * vb2_buffer_in_use() - return true if the buffer is in use and
528 * the queue cannot be freed (by the means of REQBUFS(0)) call
530 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
533 for (plane = 0; plane < vb->num_planes; ++plane) {
534 void *mem_priv = vb->planes[plane].mem_priv;
536 * If num_users() has not been provided, call_memop
537 * will return 0, apparently nobody cares about this
538 * case anyway. If num_users() returns more than 1,
539 * we are not the only user of the plane's memory.
541 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
546 EXPORT_SYMBOL(vb2_buffer_in_use);
549 * __buffers_in_use() - return true if any buffers on the queue are in use and
550 * the queue cannot be freed (by the means of REQBUFS(0)) call
552 static bool __buffers_in_use(struct vb2_queue *q)
555 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
556 if (vb2_buffer_in_use(q, q->bufs[buffer]))
563 * vb2_core_querybuf() - query video buffer information
565 * @index: id number of the buffer
566 * @pb: buffer struct passed from userspace
568 * Should be called from vidioc_querybuf ioctl handler in driver.
569 * The passed buffer should have been verified.
570 * This function fills the relevant information for the userspace.
572 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
574 call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
576 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
579 * __verify_userptr_ops() - verify that all memory operations required for
580 * USERPTR queue type have been provided
582 static int __verify_userptr_ops(struct vb2_queue *q)
584 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
585 !q->mem_ops->put_userptr)
592 * __verify_mmap_ops() - verify that all memory operations required for
593 * MMAP queue type have been provided
595 static int __verify_mmap_ops(struct vb2_queue *q)
597 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
598 !q->mem_ops->put || !q->mem_ops->mmap)
605 * __verify_dmabuf_ops() - verify that all memory operations required for
606 * DMABUF queue type have been provided
608 static int __verify_dmabuf_ops(struct vb2_queue *q)
610 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
611 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
612 !q->mem_ops->unmap_dmabuf)
619 * vb2_verify_memory_type() - Check whether the memory type and buffer type
620 * passed to a buffer operation are compatible with the queue.
622 int vb2_verify_memory_type(struct vb2_queue *q,
623 enum vb2_memory memory, unsigned int type)
625 if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
626 memory != VB2_MEMORY_DMABUF) {
627 dprintk(1, "unsupported memory type\n");
631 if (type != q->type) {
632 dprintk(1, "requested type is incorrect\n");
637 * Make sure all the required memory ops for given memory type
640 if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
641 dprintk(1, "MMAP for current setup unsupported\n");
645 if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
646 dprintk(1, "USERPTR for current setup unsupported\n");
650 if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
651 dprintk(1, "DMABUF for current setup unsupported\n");
656 * Place the busy tests at the end: -EBUSY can be ignored when
657 * create_bufs is called with count == 0, but count == 0 should still
658 * do the memory and type validation.
660 if (vb2_fileio_is_active(q)) {
661 dprintk(1, "file io in progress\n");
666 EXPORT_SYMBOL(vb2_verify_memory_type);
669 * vb2_core_reqbufs() - Initiate streaming
670 * @q: videobuf2 queue
671 * @memory: memory type
672 * @count: requested buffer count
674 * Should be called from vidioc_reqbufs ioctl handler of a driver.
676 * 1) verifies streaming parameters passed from the userspace,
677 * 2) sets up the queue,
678 * 3) negotiates number of buffers and planes per buffer with the driver
679 * to be used during streaming,
680 * 4) allocates internal buffer structures (struct vb2_buffer), according to
681 * the agreed parameters,
682 * 5) for MMAP memory type, allocates actual video memory, using the
683 * memory handling/allocation routines provided during queue initialization
685 * If req->count is 0, all the memory will be freed instead.
686 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
687 * and the queue is not busy, memory will be reallocated.
689 * The return values from this function are intended to be directly returned
690 * from vidioc_reqbufs handler in driver.
692 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
695 unsigned int num_buffers, allocated_buffers, num_planes = 0;
696 unsigned plane_sizes[VB2_MAX_PLANES] = { };
700 dprintk(1, "streaming active\n");
704 if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
706 * We already have buffers allocated, so first check if they
707 * are not in use and can be freed.
709 mutex_lock(&q->mmap_lock);
710 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
711 mutex_unlock(&q->mmap_lock);
712 dprintk(1, "memory in use, cannot free\n");
717 * Call queue_cancel to clean up any buffers in the PREPARED or
718 * QUEUED state which is possible if buffers were prepared or
719 * queued without ever calling STREAMON.
721 __vb2_queue_cancel(q);
722 ret = __vb2_queue_free(q, q->num_buffers);
723 mutex_unlock(&q->mmap_lock);
728 * In case of REQBUFS(0) return immediately without calling
729 * driver's queue_setup() callback and allocating resources.
736 * Make sure the requested values and current defaults are sane.
738 num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
739 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
740 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
744 * Ask the driver how many buffers and planes per buffer it requires.
745 * Driver also sets the size and allocator context for each plane.
747 ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
748 plane_sizes, q->alloc_ctx);
752 /* Finally, allocate buffers and video memory */
754 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
755 if (allocated_buffers == 0) {
756 dprintk(1, "memory allocation failed\n");
761 * There is no point in continuing if we can't allocate the minimum
762 * number of buffers needed by this vb2_queue.
764 if (allocated_buffers < q->min_buffers_needed)
768 * Check if driver can handle the allocated number of buffers.
770 if (!ret && allocated_buffers < num_buffers) {
771 num_buffers = allocated_buffers;
773 * num_planes is set by the previous queue_setup(), but since it
774 * signals to queue_setup() whether it is called from create_bufs()
775 * vs reqbufs() we zero it here to signal that queue_setup() is
776 * called for the reqbufs() case.
780 ret = call_qop(q, queue_setup, q, &num_buffers,
781 &num_planes, plane_sizes, q->alloc_ctx);
783 if (!ret && allocated_buffers < num_buffers)
787 * Either the driver has accepted a smaller number of buffers,
788 * or .queue_setup() returned an error
792 mutex_lock(&q->mmap_lock);
793 q->num_buffers = allocated_buffers;
797 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
798 * from q->num_buffers.
800 __vb2_queue_free(q, allocated_buffers);
801 mutex_unlock(&q->mmap_lock);
804 mutex_unlock(&q->mmap_lock);
807 * Return the number of successfully allocated buffers
810 *count = allocated_buffers;
811 q->waiting_for_buffers = !q->is_output;
815 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
818 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
819 * @q: videobuf2 queue
820 * @memory: memory type
821 * @count: requested buffer count
822 * @parg: parameter passed to device driver
824 * Should be called from vidioc_create_bufs ioctl handler of a driver.
826 * 1) verifies parameter sanity
827 * 2) calls the .queue_setup() queue operation
828 * 3) performs any necessary memory allocations
830 * The return values from this function are intended to be directly returned
831 * from vidioc_create_bufs handler in driver.
833 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
834 unsigned int *count, unsigned requested_planes,
835 const unsigned requested_sizes[])
837 unsigned int num_planes = 0, num_buffers, allocated_buffers;
838 unsigned plane_sizes[VB2_MAX_PLANES] = { };
841 if (q->num_buffers == VB2_MAX_FRAME) {
842 dprintk(1, "maximum number of buffers already allocated\n");
846 if (!q->num_buffers) {
847 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
849 q->waiting_for_buffers = !q->is_output;
852 num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
854 if (requested_planes && requested_sizes) {
855 num_planes = requested_planes;
856 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
860 * Ask the driver, whether the requested number of buffers, planes per
861 * buffer and their sizes are acceptable
863 ret = call_qop(q, queue_setup, q, &num_buffers,
864 &num_planes, plane_sizes, q->alloc_ctx);
868 /* Finally, allocate buffers and video memory */
869 allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
870 num_planes, plane_sizes);
871 if (allocated_buffers == 0) {
872 dprintk(1, "memory allocation failed\n");
877 * Check if driver can handle the so far allocated number of buffers.
879 if (allocated_buffers < num_buffers) {
880 num_buffers = allocated_buffers;
883 * q->num_buffers contains the total number of buffers, that the
884 * queue driver has set up
886 ret = call_qop(q, queue_setup, q, &num_buffers,
887 &num_planes, plane_sizes, q->alloc_ctx);
889 if (!ret && allocated_buffers < num_buffers)
893 * Either the driver has accepted a smaller number of buffers,
894 * or .queue_setup() returned an error
898 mutex_lock(&q->mmap_lock);
899 q->num_buffers += allocated_buffers;
903 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
904 * from q->num_buffers.
906 __vb2_queue_free(q, allocated_buffers);
907 mutex_unlock(&q->mmap_lock);
910 mutex_unlock(&q->mmap_lock);
913 * Return the number of successfully allocated buffers
916 *count = allocated_buffers;
920 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
923 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
924 * @vb: vb2_buffer to which the plane in question belongs to
925 * @plane_no: plane number for which the address is to be returned
927 * This function returns a kernel virtual address of a given plane if
928 * such a mapping exist, NULL otherwise.
930 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
932 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
935 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
938 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
941 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
942 * @vb: vb2_buffer to which the plane in question belongs to
943 * @plane_no: plane number for which the cookie is to be returned
945 * This function returns an allocator specific cookie for a given plane if
946 * available, NULL otherwise. The allocator should provide some simple static
947 * inline function, which would convert this cookie to the allocator specific
948 * type that can be used directly by the driver to access the buffer. This can
949 * be for example physical address, pointer to scatter list or IOMMU mapping.
951 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
953 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
956 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
958 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
961 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
962 * @vb: vb2_buffer returned from the driver
963 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
964 * VB2_BUF_STATE_ERROR if the operation finished with an error or
965 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
966 * If start_streaming fails then it should return buffers with state
967 * VB2_BUF_STATE_QUEUED to put them back into the queue.
969 * This function should be called by the driver after a hardware operation on
970 * a buffer is finished and the buffer may be returned to userspace. The driver
971 * cannot use this buffer anymore until it is queued back to it by videobuf
972 * by the means of buf_queue callback. Only buffers previously queued to the
973 * driver by buf_queue can be passed to this function.
975 * While streaming a buffer can only be returned in state DONE or ERROR.
976 * The start_streaming op can also return them in case the DMA engine cannot
977 * be started for some reason. In that case the buffers should be returned with
980 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
982 struct vb2_queue *q = vb->vb2_queue;
986 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
989 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
990 state != VB2_BUF_STATE_ERROR &&
991 state != VB2_BUF_STATE_QUEUED &&
992 state != VB2_BUF_STATE_REQUEUEING))
993 state = VB2_BUF_STATE_ERROR;
995 #ifdef CONFIG_VIDEO_ADV_DEBUG
997 * Although this is not a callback, it still does have to balance
998 * with the buf_queue op. So update this counter manually.
1002 dprintk(4, "done processing on buffer %d, state: %d\n",
1006 for (plane = 0; plane < vb->num_planes; ++plane)
1007 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1009 spin_lock_irqsave(&q->done_lock, flags);
1010 if (state == VB2_BUF_STATE_QUEUED ||
1011 state == VB2_BUF_STATE_REQUEUEING) {
1012 vb->state = VB2_BUF_STATE_QUEUED;
1014 /* Add the buffer to the done buffers list */
1015 list_add_tail(&vb->done_entry, &q->done_list);
1018 atomic_dec(&q->owned_by_drv_count);
1019 spin_unlock_irqrestore(&q->done_lock, flags);
1021 trace_vb2_buf_done(q, vb);
1024 case VB2_BUF_STATE_QUEUED:
1026 case VB2_BUF_STATE_REQUEUEING:
1027 if (q->start_streaming_called)
1028 __enqueue_in_driver(vb);
1031 /* Inform any processes that may be waiting for buffers */
1032 wake_up(&q->done_wq);
1036 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1039 * vb2_discard_done() - discard all buffers marked as DONE
1040 * @q: videobuf2 queue
1042 * This function is intended to be used with suspend/resume operations. It
1043 * discards all 'done' buffers as they would be too old to be requested after
1046 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1047 * delayed works before calling this function to make sure no buffer will be
1048 * touched by the driver and/or hardware.
1050 void vb2_discard_done(struct vb2_queue *q)
1052 struct vb2_buffer *vb;
1053 unsigned long flags;
1055 spin_lock_irqsave(&q->done_lock, flags);
1056 list_for_each_entry(vb, &q->done_list, done_entry)
1057 vb->state = VB2_BUF_STATE_ERROR;
1058 spin_unlock_irqrestore(&q->done_lock, flags);
1060 EXPORT_SYMBOL_GPL(vb2_discard_done);
1063 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1065 static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
1070 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1071 vb, pb, vb->planes);
1072 return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1076 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1078 static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
1080 struct vb2_plane planes[VB2_MAX_PLANES];
1081 struct vb2_queue *q = vb->vb2_queue;
1085 enum dma_data_direction dma_dir =
1086 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1087 bool reacquired = vb->planes[0].mem_priv == NULL;
1089 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1090 /* Copy relevant information provided by the userspace */
1092 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1097 for (plane = 0; plane < vb->num_planes; ++plane) {
1098 /* Skip the plane if already verified */
1099 if (vb->planes[plane].m.userptr &&
1100 vb->planes[plane].m.userptr == planes[plane].m.userptr
1101 && vb->planes[plane].length == planes[plane].length)
1104 dprintk(3, "userspace address for plane %d changed, "
1105 "reacquiring memory\n", plane);
1107 /* Check if the provided plane buffer is large enough */
1108 if (planes[plane].length < vb->planes[plane].min_length) {
1109 dprintk(1, "provided buffer size %u is less than "
1110 "setup size %u for plane %d\n",
1111 planes[plane].length,
1112 vb->planes[plane].min_length,
1118 /* Release previously acquired memory if present */
1119 if (vb->planes[plane].mem_priv) {
1122 call_void_vb_qop(vb, buf_cleanup, vb);
1124 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1127 vb->planes[plane].mem_priv = NULL;
1128 vb->planes[plane].bytesused = 0;
1129 vb->planes[plane].length = 0;
1130 vb->planes[plane].m.userptr = 0;
1131 vb->planes[plane].data_offset = 0;
1133 /* Acquire each plane's memory */
1134 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1135 planes[plane].m.userptr,
1136 planes[plane].length, dma_dir);
1137 if (IS_ERR_OR_NULL(mem_priv)) {
1138 dprintk(1, "failed acquiring userspace "
1139 "memory for plane %d\n", plane);
1140 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1143 vb->planes[plane].mem_priv = mem_priv;
1147 * Now that everything is in order, copy relevant information
1148 * provided by userspace.
1150 for (plane = 0; plane < vb->num_planes; ++plane) {
1151 vb->planes[plane].bytesused = planes[plane].bytesused;
1152 vb->planes[plane].length = planes[plane].length;
1153 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1154 vb->planes[plane].data_offset = planes[plane].data_offset;
1159 * One or more planes changed, so we must call buf_init to do
1160 * the driver-specific initialization on the newly acquired
1161 * buffer, if provided.
1163 ret = call_vb_qop(vb, buf_init, vb);
1165 dprintk(1, "buffer initialization failed\n");
1170 ret = call_vb_qop(vb, buf_prepare, vb);
1172 dprintk(1, "buffer preparation failed\n");
1173 call_void_vb_qop(vb, buf_cleanup, vb);
1179 /* In case of errors, release planes that were already acquired */
1180 for (plane = 0; plane < vb->num_planes; ++plane) {
1181 if (vb->planes[plane].mem_priv)
1182 call_void_memop(vb, put_userptr,
1183 vb->planes[plane].mem_priv);
1184 vb->planes[plane].mem_priv = NULL;
1185 vb->planes[plane].m.userptr = 0;
1186 vb->planes[plane].length = 0;
1193 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1195 static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
1197 struct vb2_plane planes[VB2_MAX_PLANES];
1198 struct vb2_queue *q = vb->vb2_queue;
1202 enum dma_data_direction dma_dir =
1203 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1204 bool reacquired = vb->planes[0].mem_priv == NULL;
1206 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1207 /* Copy relevant information provided by the userspace */
1209 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1214 for (plane = 0; plane < vb->num_planes; ++plane) {
1215 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1217 if (IS_ERR_OR_NULL(dbuf)) {
1218 dprintk(1, "invalid dmabuf fd for plane %d\n",
1224 /* use DMABUF size if length is not provided */
1225 if (planes[plane].length == 0)
1226 planes[plane].length = dbuf->size;
1228 if (planes[plane].length < vb->planes[plane].min_length) {
1229 dprintk(1, "invalid dmabuf length for plane %d\n",
1236 /* Skip the plane if already verified */
1237 if (dbuf == vb->planes[plane].dbuf &&
1238 vb->planes[plane].length == planes[plane].length) {
1243 dprintk(1, "buffer for plane %d changed\n", plane);
1247 call_void_vb_qop(vb, buf_cleanup, vb);
1250 /* Release previously acquired memory if present */
1251 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1252 vb->planes[plane].bytesused = 0;
1253 vb->planes[plane].length = 0;
1254 vb->planes[plane].m.fd = 0;
1255 vb->planes[plane].data_offset = 0;
1257 /* Acquire each plane's memory */
1258 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1259 q->alloc_ctx[plane], dbuf, planes[plane].length,
1261 if (IS_ERR(mem_priv)) {
1262 dprintk(1, "failed to attach dmabuf\n");
1263 ret = PTR_ERR(mem_priv);
1268 vb->planes[plane].dbuf = dbuf;
1269 vb->planes[plane].mem_priv = mem_priv;
1272 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1273 * really we want to do this just before the DMA, not while queueing
1276 for (plane = 0; plane < vb->num_planes; ++plane) {
1277 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1279 dprintk(1, "failed to map dmabuf for plane %d\n",
1283 vb->planes[plane].dbuf_mapped = 1;
1287 * Now that everything is in order, copy relevant information
1288 * provided by userspace.
1290 for (plane = 0; plane < vb->num_planes; ++plane) {
1291 vb->planes[plane].bytesused = planes[plane].bytesused;
1292 vb->planes[plane].length = planes[plane].length;
1293 vb->planes[plane].m.fd = planes[plane].m.fd;
1294 vb->planes[plane].data_offset = planes[plane].data_offset;
1299 * Call driver-specific initialization on the newly acquired buffer,
1302 ret = call_vb_qop(vb, buf_init, vb);
1304 dprintk(1, "buffer initialization failed\n");
1309 ret = call_vb_qop(vb, buf_prepare, vb);
1311 dprintk(1, "buffer preparation failed\n");
1312 call_void_vb_qop(vb, buf_cleanup, vb);
1318 /* In case of errors, release planes that were already acquired */
1319 __vb2_buf_dmabuf_put(vb);
1325 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1327 static void __enqueue_in_driver(struct vb2_buffer *vb)
1329 struct vb2_queue *q = vb->vb2_queue;
1332 vb->state = VB2_BUF_STATE_ACTIVE;
1333 atomic_inc(&q->owned_by_drv_count);
1335 trace_vb2_buf_queue(q, vb);
1338 for (plane = 0; plane < vb->num_planes; ++plane)
1339 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1341 call_void_vb_qop(vb, buf_queue, vb);
1344 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1346 struct vb2_queue *q = vb->vb2_queue;
1350 dprintk(1, "fatal error occurred on queue\n");
1354 vb->state = VB2_BUF_STATE_PREPARING;
1356 switch (q->memory) {
1357 case VB2_MEMORY_MMAP:
1358 ret = __qbuf_mmap(vb, pb);
1360 case VB2_MEMORY_USERPTR:
1361 ret = __qbuf_userptr(vb, pb);
1363 case VB2_MEMORY_DMABUF:
1364 ret = __qbuf_dmabuf(vb, pb);
1367 WARN(1, "Invalid queue type\n");
1372 dprintk(1, "buffer preparation failed: %d\n", ret);
1373 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1379 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
1381 * @q: videobuf2 queue
1382 * @index: id number of the buffer
1383 * @pb: buffer structure passed from userspace to vidioc_prepare_buf
1386 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1387 * The passed buffer should have been verified.
1388 * This function calls buf_prepare callback in the driver (if provided),
1389 * in which driver-specific buffer initialization can be performed,
1391 * The return values from this function are intended to be directly returned
1392 * from vidioc_prepare_buf handler in driver.
1394 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1396 struct vb2_buffer *vb;
1399 vb = q->bufs[index];
1400 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1401 dprintk(1, "invalid buffer state %d\n",
1406 ret = __buf_prepare(vb, pb);
1410 /* Fill buffer information for the userspace */
1411 call_void_bufop(q, fill_user_buffer, vb, pb);
1413 dprintk(1, "prepare of buffer %d succeeded\n", vb->index);
1417 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1420 * vb2_start_streaming() - Attempt to start streaming.
1421 * @q: videobuf2 queue
1423 * Attempt to start streaming. When this function is called there must be
1424 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1425 * number of buffers required for the DMA engine to function). If the
1426 * @start_streaming op fails it is supposed to return all the driver-owned
1427 * buffers back to vb2 in state QUEUED. Check if that happened and if
1428 * not warn and reclaim them forcefully.
1430 static int vb2_start_streaming(struct vb2_queue *q)
1432 struct vb2_buffer *vb;
1436 * If any buffers were queued before streamon,
1437 * we can now pass them to driver for processing.
1439 list_for_each_entry(vb, &q->queued_list, queued_entry)
1440 __enqueue_in_driver(vb);
1442 /* Tell the driver to start streaming */
1443 q->start_streaming_called = 1;
1444 ret = call_qop(q, start_streaming, q,
1445 atomic_read(&q->owned_by_drv_count));
1449 q->start_streaming_called = 0;
1451 dprintk(1, "driver refused to start streaming\n");
1453 * If you see this warning, then the driver isn't cleaning up properly
1454 * after a failed start_streaming(). See the start_streaming()
1455 * documentation in videobuf2-core.h for more information how buffers
1456 * should be returned to vb2 in start_streaming().
1458 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1462 * Forcefully reclaim buffers if the driver did not
1463 * correctly return them to vb2.
1465 for (i = 0; i < q->num_buffers; ++i) {
1467 if (vb->state == VB2_BUF_STATE_ACTIVE)
1468 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1470 /* Must be zero now */
1471 WARN_ON(atomic_read(&q->owned_by_drv_count));
1474 * If done_list is not empty, then start_streaming() didn't call
1475 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1478 WARN_ON(!list_empty(&q->done_list));
1483 * vb2_core_qbuf() - Queue a buffer from userspace
1484 * @q: videobuf2 queue
1485 * @index: id number of the buffer
1486 * @pb: buffer structure passed from userspace to vidioc_qbuf handler
1489 * Should be called from vidioc_qbuf ioctl handler of a driver.
1490 * The passed buffer should have been verified.
1492 * 1) if necessary, calls buf_prepare callback in the driver (if provided), in
1493 * which driver-specific buffer initialization can be performed,
1494 * 2) if streaming is on, queues the buffer in driver by the means of buf_queue
1495 * callback for processing.
1497 * The return values from this function are intended to be directly returned
1498 * from vidioc_qbuf handler in driver.
1500 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1502 struct vb2_buffer *vb;
1505 vb = q->bufs[index];
1507 switch (vb->state) {
1508 case VB2_BUF_STATE_DEQUEUED:
1509 ret = __buf_prepare(vb, pb);
1513 case VB2_BUF_STATE_PREPARED:
1515 case VB2_BUF_STATE_PREPARING:
1516 dprintk(1, "buffer still being prepared\n");
1519 dprintk(1, "invalid buffer state %d\n", vb->state);
1524 * Add to the queued buffers list, a buffer will stay on it until
1525 * dequeued in dqbuf.
1527 list_add_tail(&vb->queued_entry, &q->queued_list);
1529 q->waiting_for_buffers = false;
1530 vb->state = VB2_BUF_STATE_QUEUED;
1533 call_void_bufop(q, copy_timestamp, vb, pb);
1535 trace_vb2_qbuf(q, vb);
1538 * If already streaming, give the buffer to driver for processing.
1539 * If not, the buffer will be given to driver on next streamon.
1541 if (q->start_streaming_called)
1542 __enqueue_in_driver(vb);
1544 /* Fill buffer information for the userspace */
1546 call_void_bufop(q, fill_user_buffer, vb, pb);
1549 * If streamon has been called, and we haven't yet called
1550 * start_streaming() since not enough buffers were queued, and
1551 * we now have reached the minimum number of queued buffers,
1552 * then we can finally call start_streaming().
1554 if (q->streaming && !q->start_streaming_called &&
1555 q->queued_count >= q->min_buffers_needed) {
1556 ret = vb2_start_streaming(q);
1561 dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
1564 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1567 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1570 * Will sleep if required for nonblocking == false.
1572 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1575 * All operations on vb_done_list are performed under done_lock
1576 * spinlock protection. However, buffers may be removed from
1577 * it and returned to userspace only while holding both driver's
1578 * lock and the done_lock spinlock. Thus we can be sure that as
1579 * long as we hold the driver's lock, the list will remain not
1580 * empty if list_empty() check succeeds.
1586 if (!q->streaming) {
1587 dprintk(1, "streaming off, will not wait for buffers\n");
1592 dprintk(1, "Queue in error state, will not wait for buffers\n");
1596 if (q->last_buffer_dequeued) {
1597 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1601 if (!list_empty(&q->done_list)) {
1603 * Found a buffer that we were waiting for.
1609 dprintk(1, "nonblocking and no buffers to dequeue, "
1615 * We are streaming and blocking, wait for another buffer to
1616 * become ready or for streamoff. Driver's lock is released to
1617 * allow streamoff or qbuf to be called while waiting.
1619 call_void_qop(q, wait_prepare, q);
1622 * All locks have been released, it is safe to sleep now.
1624 dprintk(3, "will sleep waiting for buffers\n");
1625 ret = wait_event_interruptible(q->done_wq,
1626 !list_empty(&q->done_list) || !q->streaming ||
1630 * We need to reevaluate both conditions again after reacquiring
1631 * the locks or return an error if one occurred.
1633 call_void_qop(q, wait_finish, q);
1635 dprintk(1, "sleep was interrupted\n");
1643 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1645 * Will sleep if required for nonblocking == false.
1647 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1648 void *pb, int nonblocking)
1650 unsigned long flags;
1654 * Wait for at least one buffer to become available on the done_list.
1656 ret = __vb2_wait_for_done_vb(q, nonblocking);
1661 * Driver's lock has been held since we last verified that done_list
1662 * is not empty, so no need for another list_empty(done_list) check.
1664 spin_lock_irqsave(&q->done_lock, flags);
1665 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1667 * Only remove the buffer from done_list if v4l2_buffer can handle all
1670 ret = call_bufop(q, verify_planes_array, *vb, pb);
1672 list_del(&(*vb)->done_entry);
1673 spin_unlock_irqrestore(&q->done_lock, flags);
1679 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1680 * @q: videobuf2 queue
1682 * This function will wait until all buffers that have been given to the driver
1683 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1684 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1685 * taken, for example from stop_streaming() callback.
1687 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1689 if (!q->streaming) {
1690 dprintk(1, "streaming off, will not wait for buffers\n");
1694 if (q->start_streaming_called)
1695 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1698 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1701 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1703 static void __vb2_dqbuf(struct vb2_buffer *vb)
1705 struct vb2_queue *q = vb->vb2_queue;
1708 /* nothing to do if the buffer is already dequeued */
1709 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1712 vb->state = VB2_BUF_STATE_DEQUEUED;
1714 /* unmap DMABUF buffer */
1715 if (q->memory == VB2_MEMORY_DMABUF)
1716 for (i = 0; i < vb->num_planes; ++i) {
1717 if (!vb->planes[i].dbuf_mapped)
1719 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1720 vb->planes[i].dbuf_mapped = 0;
1725 * vb2_dqbuf() - Dequeue a buffer to the userspace
1726 * @q: videobuf2 queue
1727 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler
1729 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1730 * buffers ready for dequeuing are present. Normally the driver
1731 * would be passing (file->f_flags & O_NONBLOCK) here
1733 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1734 * The passed buffer should have been verified.
1736 * 1) calls buf_finish callback in the driver (if provided), in which
1737 * driver can perform any additional operations that may be required before
1738 * returning the buffer to userspace, such as cache sync,
1739 * 2) the buffer struct members are filled with relevant information for
1742 * The return values from this function are intended to be directly returned
1743 * from vidioc_dqbuf handler in driver.
1745 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1748 struct vb2_buffer *vb = NULL;
1751 ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1755 switch (vb->state) {
1756 case VB2_BUF_STATE_DONE:
1757 dprintk(3, "returning done buffer\n");
1759 case VB2_BUF_STATE_ERROR:
1760 dprintk(3, "returning done buffer with errors\n");
1763 dprintk(1, "invalid buffer state\n");
1767 call_void_vb_qop(vb, buf_finish, vb);
1770 *pindex = vb->index;
1772 /* Fill buffer information for the userspace */
1774 call_void_bufop(q, fill_user_buffer, vb, pb);
1776 /* Remove from videobuf queue */
1777 list_del(&vb->queued_entry);
1780 trace_vb2_dqbuf(q, vb);
1782 /* go back to dequeued state */
1785 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1786 vb->index, vb->state);
1791 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1794 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1796 * Removes all queued buffers from driver's queue and all buffers queued by
1797 * userspace from videobuf's queue. Returns to state after reqbufs.
1799 static void __vb2_queue_cancel(struct vb2_queue *q)
1804 * Tell driver to stop all transactions and release all queued
1807 if (q->start_streaming_called)
1808 call_void_qop(q, stop_streaming, q);
1811 * If you see this warning, then the driver isn't cleaning up properly
1812 * in stop_streaming(). See the stop_streaming() documentation in
1813 * videobuf2-core.h for more information how buffers should be returned
1814 * to vb2 in stop_streaming().
1816 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1817 for (i = 0; i < q->num_buffers; ++i)
1818 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1819 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1820 /* Must be zero now */
1821 WARN_ON(atomic_read(&q->owned_by_drv_count));
1825 q->start_streaming_called = 0;
1826 q->queued_count = 0;
1830 * Remove all buffers from videobuf's list...
1832 INIT_LIST_HEAD(&q->queued_list);
1834 * ...and done list; userspace will not receive any buffers it
1835 * has not already dequeued before initiating cancel.
1837 INIT_LIST_HEAD(&q->done_list);
1838 atomic_set(&q->owned_by_drv_count, 0);
1839 wake_up_all(&q->done_wq);
1842 * Reinitialize all buffers for next use.
1843 * Make sure to call buf_finish for any queued buffers. Normally
1844 * that's done in dqbuf, but that's not going to happen when we
1845 * cancel the whole queue. Note: this code belongs here, not in
1846 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
1847 * call to __fill_user_buffer() after buf_finish(). That order can't
1848 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1850 for (i = 0; i < q->num_buffers; ++i) {
1851 struct vb2_buffer *vb = q->bufs[i];
1853 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1854 vb->state = VB2_BUF_STATE_PREPARED;
1855 call_void_vb_qop(vb, buf_finish, vb);
1861 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1865 if (type != q->type) {
1866 dprintk(1, "invalid stream type\n");
1871 dprintk(3, "already streaming\n");
1875 if (!q->num_buffers) {
1876 dprintk(1, "no buffers have been allocated\n");
1880 if (q->num_buffers < q->min_buffers_needed) {
1881 dprintk(1, "need at least %u allocated buffers\n",
1882 q->min_buffers_needed);
1887 * Tell driver to start streaming provided sufficient buffers
1890 if (q->queued_count >= q->min_buffers_needed) {
1891 ret = v4l_vb2q_enable_media_source(q);
1894 ret = vb2_start_streaming(q);
1896 __vb2_queue_cancel(q);
1903 dprintk(3, "successful\n");
1906 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1909 * vb2_queue_error() - signal a fatal error on the queue
1910 * @q: videobuf2 queue
1912 * Flag that a fatal unrecoverable error has occurred and wake up all processes
1913 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
1914 * buffers will return -EIO.
1916 * The error flag will be cleared when cancelling the queue, either from
1917 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
1918 * function before starting the stream, otherwise the error flag will remain set
1919 * until the queue is released when closing the device node.
1921 void vb2_queue_error(struct vb2_queue *q)
1925 wake_up_all(&q->done_wq);
1927 EXPORT_SYMBOL_GPL(vb2_queue_error);
1929 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1931 if (type != q->type) {
1932 dprintk(1, "invalid stream type\n");
1937 * Cancel will pause streaming and remove all buffers from the driver
1938 * and videobuf, effectively returning control over them to userspace.
1940 * Note that we do this even if q->streaming == 0: if you prepare or
1941 * queue buffers, and then call streamoff without ever having called
1942 * streamon, you would still expect those buffers to be returned to
1943 * their normal dequeued state.
1945 __vb2_queue_cancel(q);
1946 q->waiting_for_buffers = !q->is_output;
1947 q->last_buffer_dequeued = false;
1949 dprintk(3, "successful\n");
1952 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1955 * __find_plane_by_offset() - find plane associated with the given offset off
1957 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1958 unsigned int *_buffer, unsigned int *_plane)
1960 struct vb2_buffer *vb;
1961 unsigned int buffer, plane;
1964 * Go over all buffers and their planes, comparing the given offset
1965 * with an offset assigned to each plane. If a match is found,
1966 * return its buffer and plane numbers.
1968 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1969 vb = q->bufs[buffer];
1971 for (plane = 0; plane < vb->num_planes; ++plane) {
1972 if (vb->planes[plane].m.offset == off) {
1984 * vb2_core_expbuf() - Export a buffer as a file descriptor
1985 * @q: videobuf2 queue
1986 * @fd: file descriptor associated with DMABUF (set by driver) *
1987 * @type: buffer type
1988 * @index: id number of the buffer
1989 * @plane: index of the plane to be exported, 0 for single plane queues
1990 * @flags: flags for newly created file, currently only O_CLOEXEC is
1991 * supported, refer to manual of open syscall for more details
1993 * The return values from this function are intended to be directly returned
1994 * from vidioc_expbuf handler in driver.
1996 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1997 unsigned int index, unsigned int plane, unsigned int flags)
1999 struct vb2_buffer *vb = NULL;
2000 struct vb2_plane *vb_plane;
2002 struct dma_buf *dbuf;
2004 if (q->memory != VB2_MEMORY_MMAP) {
2005 dprintk(1, "queue is not currently set up for mmap\n");
2009 if (!q->mem_ops->get_dmabuf) {
2010 dprintk(1, "queue does not support DMA buffer exporting\n");
2014 if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2015 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2019 if (type != q->type) {
2020 dprintk(1, "invalid buffer type\n");
2024 if (index >= q->num_buffers) {
2025 dprintk(1, "buffer index out of range\n");
2029 vb = q->bufs[index];
2031 if (plane >= vb->num_planes) {
2032 dprintk(1, "buffer plane out of range\n");
2036 if (vb2_fileio_is_active(q)) {
2037 dprintk(1, "expbuf: file io in progress\n");
2041 vb_plane = &vb->planes[plane];
2043 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
2045 if (IS_ERR_OR_NULL(dbuf)) {
2046 dprintk(1, "failed to export buffer %d, plane %d\n",
2051 ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2053 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2059 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2065 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2068 * vb2_mmap() - map video buffers into application address space
2069 * @q: videobuf2 queue
2070 * @vma: vma passed to the mmap file operation handler in the driver
2072 * Should be called from mmap file operation handler of a driver.
2073 * This function maps one plane of one of the available video buffers to
2074 * userspace. To map whole video memory allocated on reqbufs, this function
2075 * has to be called once per each plane per each buffer previously allocated.
2077 * When the userspace application calls mmap, it passes to it an offset returned
2078 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2079 * a "cookie", which is then used to identify the plane to be mapped.
2080 * This function finds a plane with a matching offset and a mapping is performed
2081 * by the means of a provided memory operation.
2083 * The return values from this function are intended to be directly returned
2084 * from the mmap handler in driver.
2086 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2088 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2089 struct vb2_buffer *vb;
2090 unsigned int buffer = 0, plane = 0;
2092 unsigned long length;
2094 if (q->memory != VB2_MEMORY_MMAP) {
2095 dprintk(1, "queue is not currently set up for mmap\n");
2100 * Check memory area access mode.
2102 if (!(vma->vm_flags & VM_SHARED)) {
2103 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2107 if (!(vma->vm_flags & VM_WRITE)) {
2108 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2112 if (!(vma->vm_flags & VM_READ)) {
2113 dprintk(1, "invalid vma flags, VM_READ needed\n");
2117 if (vb2_fileio_is_active(q)) {
2118 dprintk(1, "mmap: file io in progress\n");
2123 * Find the plane corresponding to the offset passed by userspace.
2125 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2129 vb = q->bufs[buffer];
2132 * MMAP requires page_aligned buffers.
2133 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2134 * so, we need to do the same here.
2136 length = PAGE_ALIGN(vb->planes[plane].length);
2137 if (length < (vma->vm_end - vma->vm_start)) {
2139 "MMAP invalid, as it would overflow buffer length\n");
2143 mutex_lock(&q->mmap_lock);
2144 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2145 mutex_unlock(&q->mmap_lock);
2149 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2152 EXPORT_SYMBOL_GPL(vb2_mmap);
2155 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2158 unsigned long pgoff,
2159 unsigned long flags)
2161 unsigned long off = pgoff << PAGE_SHIFT;
2162 struct vb2_buffer *vb;
2163 unsigned int buffer, plane;
2167 if (q->memory != VB2_MEMORY_MMAP) {
2168 dprintk(1, "queue is not currently set up for mmap\n");
2173 * Find the plane corresponding to the offset passed by userspace.
2175 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2179 vb = q->bufs[buffer];
2181 vaddr = vb2_plane_vaddr(vb, plane);
2182 return vaddr ? (unsigned long)vaddr : -EINVAL;
2184 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2188 * vb2_core_queue_init() - initialize a videobuf2 queue
2189 * @q: videobuf2 queue; this structure should be allocated in driver
2191 * The vb2_queue structure should be allocated by the driver. The driver is
2192 * responsible of clearing it's content and setting initial values for some
2193 * required entries before calling this function.
2194 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2195 * to the struct vb2_queue description in include/media/videobuf2-core.h
2196 * for more information.
2198 int vb2_core_queue_init(struct vb2_queue *q)
2205 WARN_ON(!q->mem_ops) ||
2206 WARN_ON(!q->type) ||
2207 WARN_ON(!q->io_modes) ||
2208 WARN_ON(!q->ops->queue_setup) ||
2209 WARN_ON(!q->ops->buf_queue))
2212 INIT_LIST_HEAD(&q->queued_list);
2213 INIT_LIST_HEAD(&q->done_list);
2214 spin_lock_init(&q->done_lock);
2215 mutex_init(&q->mmap_lock);
2216 init_waitqueue_head(&q->done_wq);
2218 if (q->buf_struct_size == 0)
2219 q->buf_struct_size = sizeof(struct vb2_buffer);
2223 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2225 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2226 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2228 * vb2_core_queue_release() - stop streaming, release the queue and free memory
2229 * @q: videobuf2 queue
2231 * This function stops streaming and performs necessary clean ups, including
2232 * freeing video buffer memory. The driver is responsible for freeing
2233 * the vb2_queue structure itself.
2235 void vb2_core_queue_release(struct vb2_queue *q)
2237 __vb2_cleanup_fileio(q);
2238 __vb2_queue_cancel(q);
2239 mutex_lock(&q->mmap_lock);
2240 __vb2_queue_free(q, q->num_buffers);
2241 mutex_unlock(&q->mmap_lock);
2243 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2246 * vb2_core_poll() - implements poll userspace operation
2247 * @q: videobuf2 queue
2248 * @file: file argument passed to the poll file operation handler
2249 * @wait: wait argument passed to the poll file operation handler
2251 * This function implements poll file operation handler for a driver.
2252 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2253 * be informed that the file descriptor of a video device is available for
2255 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2256 * will be reported as available for writing.
2258 * The return values from this function are intended to be directly returned
2259 * from poll handler in driver.
2261 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
2264 unsigned long req_events = poll_requested_events(wait);
2265 struct vb2_buffer *vb = NULL;
2266 unsigned long flags;
2268 if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2270 if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2274 * Start file I/O emulator only if streaming API has not been used yet.
2276 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2277 if (!q->is_output && (q->io_modes & VB2_READ) &&
2278 (req_events & (POLLIN | POLLRDNORM))) {
2279 if (__vb2_init_fileio(q, 1))
2282 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2283 (req_events & (POLLOUT | POLLWRNORM))) {
2284 if (__vb2_init_fileio(q, 0))
2287 * Write to OUTPUT queue can be done immediately.
2289 return POLLOUT | POLLWRNORM;
2294 * There is nothing to wait for if the queue isn't streaming, or if the
2295 * error flag is set.
2297 if (!vb2_is_streaming(q) || q->error)
2301 * If this quirk is set and QBUF hasn't been called yet then
2302 * return POLLERR as well. This only affects capture queues, output
2303 * queues will always initialize waiting_for_buffers to false.
2304 * This quirk is set by V4L2 for backwards compatibility reasons.
2306 if (q->quirk_poll_must_check_waiting_for_buffers &&
2307 q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2311 * For output streams you can call write() as long as there are fewer
2312 * buffers queued than there are buffers available.
2314 if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2315 return POLLOUT | POLLWRNORM;
2317 if (list_empty(&q->done_list)) {
2319 * If the last buffer was dequeued from a capture queue,
2320 * return immediately. DQBUF will return -EPIPE.
2322 if (q->last_buffer_dequeued)
2323 return POLLIN | POLLRDNORM;
2325 poll_wait(file, &q->done_wq, wait);
2329 * Take first buffer available for dequeuing.
2331 spin_lock_irqsave(&q->done_lock, flags);
2332 if (!list_empty(&q->done_list))
2333 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2335 spin_unlock_irqrestore(&q->done_lock, flags);
2337 if (vb && (vb->state == VB2_BUF_STATE_DONE
2338 || vb->state == VB2_BUF_STATE_ERROR)) {
2339 return (q->is_output) ?
2340 POLLOUT | POLLWRNORM :
2341 POLLIN | POLLRDNORM;
2345 EXPORT_SYMBOL_GPL(vb2_core_poll);
2348 * struct vb2_fileio_buf - buffer context used by file io emulator
2350 * vb2 provides a compatibility layer and emulator of file io (read and
2351 * write) calls on top of streaming API. This structure is used for
2352 * tracking context related to the buffers.
2354 struct vb2_fileio_buf {
2358 unsigned int queued:1;
2362 * struct vb2_fileio_data - queue context used by file io emulator
2364 * @cur_index: the index of the buffer currently being read from or
2365 * written to. If equal to q->num_buffers then a new buffer
2367 * @initial_index: in the read() case all buffers are queued up immediately
2368 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2369 * buffers. However, in the write() case no buffers are initially
2370 * queued, instead whenever a buffer is full it is queued up by
2371 * __vb2_perform_fileio(). Only once all available buffers have
2372 * been queued up will __vb2_perform_fileio() start to dequeue
2373 * buffers. This means that initially __vb2_perform_fileio()
2374 * needs to know what buffer index to use when it is queuing up
2375 * the buffers for the first time. That initial index is stored
2376 * in this field. Once it is equal to q->num_buffers all
2377 * available buffers have been queued and __vb2_perform_fileio()
2378 * should start the normal dequeue/queue cycle.
2380 * vb2 provides a compatibility layer and emulator of file io (read and
2381 * write) calls on top of streaming API. For proper operation it required
2382 * this structure to save the driver state between each call of the read
2383 * or write function.
2385 struct vb2_fileio_data {
2388 unsigned int memory;
2389 struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2390 unsigned int cur_index;
2391 unsigned int initial_index;
2392 unsigned int q_count;
2393 unsigned int dq_count;
2394 unsigned read_once:1;
2395 unsigned write_immediately:1;
2399 * __vb2_init_fileio() - initialize file io emulator
2400 * @q: videobuf2 queue
2401 * @read: mode selector (1 means read, 0 means write)
2403 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2405 struct vb2_fileio_data *fileio;
2407 unsigned int count = 0;
2412 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2413 (!read && !(q->io_modes & VB2_WRITE))))
2417 * Check if device supports mapping buffers to kernel virtual space.
2419 if (!q->mem_ops->vaddr)
2423 * Check if streaming api has not been already activated.
2425 if (q->streaming || q->num_buffers > 0)
2429 * Start with count 1, driver can increase it in queue_setup()
2433 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2434 (read) ? "read" : "write", count, q->fileio_read_once,
2435 q->fileio_write_immediately);
2437 fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2441 fileio->read_once = q->fileio_read_once;
2442 fileio->write_immediately = q->fileio_write_immediately;
2445 * Request buffers and use MMAP type to force driver
2446 * to allocate buffers by itself.
2448 fileio->count = count;
2449 fileio->memory = VB2_MEMORY_MMAP;
2450 fileio->type = q->type;
2452 ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2457 * Check if plane_count is correct
2458 * (multiplane buffers are not supported).
2460 if (q->bufs[0]->num_planes != 1) {
2466 * Get kernel address of each buffer.
2468 for (i = 0; i < q->num_buffers; i++) {
2469 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2470 if (fileio->bufs[i].vaddr == NULL) {
2474 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2478 * Read mode requires pre queuing of all buffers.
2482 * Queue all buffers.
2484 for (i = 0; i < q->num_buffers; i++) {
2485 ret = vb2_core_qbuf(q, i, NULL);
2488 fileio->bufs[i].queued = 1;
2491 * All buffers have been queued, so mark that by setting
2492 * initial_index to q->num_buffers
2494 fileio->initial_index = q->num_buffers;
2495 fileio->cur_index = q->num_buffers;
2501 ret = vb2_core_streamon(q, q->type);
2509 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2518 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2519 * @q: videobuf2 queue
2521 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2523 struct vb2_fileio_data *fileio = q->fileio;
2526 vb2_core_streamoff(q, q->type);
2529 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2531 dprintk(3, "file io emulator closed\n");
2537 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2538 * @q: videobuf2 queue
2539 * @data: pointed to target userspace buffer
2540 * @count: number of bytes to read or write
2541 * @ppos: file handle position tracking pointer
2542 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2543 * @read: access mode selector (1 means read, 0 means write)
2545 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2546 loff_t *ppos, int nonblock, int read)
2548 struct vb2_fileio_data *fileio;
2549 struct vb2_fileio_buf *buf;
2550 bool is_multiplanar = q->is_multiplanar;
2552 * When using write() to write data to an output video node the vb2 core
2553 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2554 * else is able to provide this information with the write() operation.
2556 bool copy_timestamp = !read && q->copy_timestamp;
2560 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2561 read ? "read" : "write", (long)*ppos, count,
2562 nonblock ? "non" : "");
2568 * Initialize emulator on first call.
2570 if (!vb2_fileio_is_active(q)) {
2571 ret = __vb2_init_fileio(q, read);
2572 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2579 * Check if we need to dequeue the buffer.
2581 index = fileio->cur_index;
2582 if (index >= q->num_buffers) {
2583 struct vb2_buffer *b;
2586 * Call vb2_dqbuf to get buffer back.
2588 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2589 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2592 fileio->dq_count += 1;
2594 fileio->cur_index = index;
2595 buf = &fileio->bufs[index];
2599 * Get number of bytes filled by the driver
2603 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2604 : vb2_plane_size(q->bufs[index], 0);
2605 /* Compensate for data_offset on read in the multiplanar case. */
2606 if (is_multiplanar && read &&
2607 b->planes[0].data_offset < buf->size) {
2608 buf->pos = b->planes[0].data_offset;
2609 buf->size -= buf->pos;
2612 buf = &fileio->bufs[index];
2616 * Limit count on last few bytes of the buffer.
2618 if (buf->pos + count > buf->size) {
2619 count = buf->size - buf->pos;
2620 dprintk(5, "reducing read count: %zd\n", count);
2624 * Transfer data to userspace.
2626 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2627 count, index, buf->pos);
2629 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2631 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2633 dprintk(3, "error copying data\n");
2644 * Queue next buffer if required.
2646 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2647 struct vb2_buffer *b = q->bufs[index];
2650 * Check if this is the last buffer to read.
2652 if (read && fileio->read_once && fileio->dq_count == 1) {
2653 dprintk(3, "read limit reached\n");
2654 return __vb2_cleanup_fileio(q);
2658 * Call vb2_qbuf and give buffer to the driver.
2660 b->planes[0].bytesused = buf->pos;
2663 b->timestamp = ktime_get_ns();
2664 ret = vb2_core_qbuf(q, index, NULL);
2665 dprintk(5, "vb2_dbuf result: %d\n", ret);
2670 * Buffer has been queued, update the status
2674 buf->size = vb2_plane_size(q->bufs[index], 0);
2675 fileio->q_count += 1;
2677 * If we are queuing up buffers for the first time, then
2678 * increase initial_index by one.
2680 if (fileio->initial_index < q->num_buffers)
2681 fileio->initial_index++;
2683 * The next buffer to use is either a buffer that's going to be
2684 * queued for the first time (initial_index < q->num_buffers)
2685 * or it is equal to q->num_buffers, meaning that the next
2686 * time we need to dequeue a buffer since we've now queued up
2687 * all the 'first time' buffers.
2689 fileio->cur_index = fileio->initial_index;
2693 * Return proper number of bytes processed.
2700 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2701 loff_t *ppos, int nonblocking)
2703 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2705 EXPORT_SYMBOL_GPL(vb2_read);
2707 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2708 loff_t *ppos, int nonblocking)
2710 return __vb2_perform_fileio(q, (char __user *) data, count,
2711 ppos, nonblocking, 0);
2713 EXPORT_SYMBOL_GPL(vb2_write);
2715 struct vb2_threadio_data {
2716 struct task_struct *thread;
2722 static int vb2_thread(void *data)
2724 struct vb2_queue *q = data;
2725 struct vb2_threadio_data *threadio = q->threadio;
2726 bool copy_timestamp = false;
2727 unsigned prequeue = 0;
2732 prequeue = q->num_buffers;
2733 copy_timestamp = q->copy_timestamp;
2739 struct vb2_buffer *vb;
2742 * Call vb2_dqbuf to get buffer back.
2745 vb = q->bufs[index++];
2748 call_void_qop(q, wait_finish, q);
2749 if (!threadio->stop)
2750 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2751 call_void_qop(q, wait_prepare, q);
2752 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2754 vb = q->bufs[index];
2756 if (ret || threadio->stop)
2760 if (vb->state != VB2_BUF_STATE_ERROR)
2761 if (threadio->fnc(vb, threadio->priv))
2763 call_void_qop(q, wait_finish, q);
2765 vb->timestamp = ktime_get_ns();;
2766 if (!threadio->stop)
2767 ret = vb2_core_qbuf(q, vb->index, NULL);
2768 call_void_qop(q, wait_prepare, q);
2769 if (ret || threadio->stop)
2773 /* Hmm, linux becomes *very* unhappy without this ... */
2774 while (!kthread_should_stop()) {
2775 set_current_state(TASK_INTERRUPTIBLE);
2782 * This function should not be used for anything else but the videobuf2-dvb
2783 * support. If you think you have another good use-case for this, then please
2784 * contact the linux-media mailinglist first.
2786 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2787 const char *thread_name)
2789 struct vb2_threadio_data *threadio;
2796 if (WARN_ON(q->fileio))
2799 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2800 if (threadio == NULL)
2802 threadio->fnc = fnc;
2803 threadio->priv = priv;
2805 ret = __vb2_init_fileio(q, !q->is_output);
2806 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2809 q->threadio = threadio;
2810 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2811 if (IS_ERR(threadio->thread)) {
2812 ret = PTR_ERR(threadio->thread);
2813 threadio->thread = NULL;
2819 __vb2_cleanup_fileio(q);
2824 EXPORT_SYMBOL_GPL(vb2_thread_start);
2826 int vb2_thread_stop(struct vb2_queue *q)
2828 struct vb2_threadio_data *threadio = q->threadio;
2831 if (threadio == NULL)
2833 threadio->stop = true;
2834 /* Wake up all pending sleeps in the thread */
2836 err = kthread_stop(threadio->thread);
2837 __vb2_cleanup_fileio(q);
2838 threadio->thread = NULL;
2843 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2845 MODULE_DESCRIPTION("Media buffer core framework");
2846 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2847 MODULE_LICENSE("GPL");