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;
204 * Allocate memory for all planes in this buffer
205 * NOTE: mmapped areas should be page aligned
207 for (plane = 0; plane < vb->num_planes; ++plane) {
208 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
210 mem_priv = call_ptr_memop(vb, alloc,
211 q->alloc_devs[plane] ? : q->dev,
212 q->dma_attrs, size, dma_dir, q->gfp_flags);
213 if (IS_ERR(mem_priv)) {
215 ret = PTR_ERR(mem_priv);
219 /* Associate allocator private data with this plane */
220 vb->planes[plane].mem_priv = mem_priv;
225 /* Free already allocated memory if one of the allocations failed */
226 for (; plane > 0; --plane) {
227 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
228 vb->planes[plane - 1].mem_priv = NULL;
235 * __vb2_buf_mem_free() - free memory of the given buffer
237 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
241 for (plane = 0; plane < vb->num_planes; ++plane) {
242 call_void_memop(vb, put, vb->planes[plane].mem_priv);
243 vb->planes[plane].mem_priv = NULL;
244 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
249 * __vb2_buf_userptr_put() - release userspace memory associated with
252 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
256 for (plane = 0; plane < vb->num_planes; ++plane) {
257 if (vb->planes[plane].mem_priv)
258 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
259 vb->planes[plane].mem_priv = NULL;
264 * __vb2_plane_dmabuf_put() - release memory associated with
265 * a DMABUF shared plane
267 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
273 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
275 call_void_memop(vb, detach_dmabuf, p->mem_priv);
276 dma_buf_put(p->dbuf);
283 * __vb2_buf_dmabuf_put() - release memory associated with
284 * a DMABUF shared buffer
286 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
290 for (plane = 0; plane < vb->num_planes; ++plane)
291 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
295 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
298 static void __setup_offsets(struct vb2_buffer *vb)
300 struct vb2_queue *q = vb->vb2_queue;
302 unsigned long off = 0;
305 struct vb2_buffer *prev = q->bufs[vb->index - 1];
306 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
308 off = PAGE_ALIGN(p->m.offset + p->length);
311 for (plane = 0; plane < vb->num_planes; ++plane) {
312 vb->planes[plane].m.offset = off;
314 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
315 vb->index, plane, off);
317 off += vb->planes[plane].length;
318 off = PAGE_ALIGN(off);
323 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
324 * video buffer memory for all buffers/planes on the queue and initializes the
327 * Returns the number of buffers successfully allocated.
329 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
330 unsigned int num_buffers, unsigned int num_planes,
331 const unsigned plane_sizes[VB2_MAX_PLANES])
333 unsigned int buffer, plane;
334 struct vb2_buffer *vb;
337 /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
338 num_buffers = min_t(unsigned int, num_buffers,
339 VB2_MAX_FRAME - q->num_buffers);
341 for (buffer = 0; buffer < num_buffers; ++buffer) {
342 /* Allocate videobuf buffer structures */
343 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
345 dprintk(1, "memory alloc for buffer struct failed\n");
349 vb->state = VB2_BUF_STATE_DEQUEUED;
351 vb->num_planes = num_planes;
352 vb->index = q->num_buffers + buffer;
355 for (plane = 0; plane < num_planes; ++plane) {
356 vb->planes[plane].length = plane_sizes[plane];
357 vb->planes[plane].min_length = plane_sizes[plane];
359 q->bufs[vb->index] = vb;
361 /* Allocate video buffer memory for the MMAP type */
362 if (memory == VB2_MEMORY_MMAP) {
363 ret = __vb2_buf_mem_alloc(vb);
365 dprintk(1, "failed allocating memory for "
366 "buffer %d\n", buffer);
367 q->bufs[vb->index] = NULL;
373 * Call the driver-provided buffer initialization
374 * callback, if given. An error in initialization
375 * results in queue setup failure.
377 ret = call_vb_qop(vb, buf_init, vb);
379 dprintk(1, "buffer %d %p initialization"
380 " failed\n", buffer, vb);
381 __vb2_buf_mem_free(vb);
382 q->bufs[vb->index] = NULL;
389 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
396 * __vb2_free_mem() - release all video buffer memory for a given queue
398 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
401 struct vb2_buffer *vb;
403 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
405 vb = q->bufs[buffer];
409 /* Free MMAP buffers or release USERPTR buffers */
410 if (q->memory == VB2_MEMORY_MMAP)
411 __vb2_buf_mem_free(vb);
412 else if (q->memory == VB2_MEMORY_DMABUF)
413 __vb2_buf_dmabuf_put(vb);
415 __vb2_buf_userptr_put(vb);
420 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
421 * related information, if no buffers are left return the queue to an
422 * uninitialized state. Might be called even if the queue has already been freed.
424 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
429 * Sanity check: when preparing a buffer the queue lock is released for
430 * a short while (see __buf_prepare for the details), which would allow
431 * a race with a reqbufs which can call this function. Removing the
432 * buffers from underneath __buf_prepare is obviously a bad idea, so we
433 * check if any of the buffers is in the state PREPARING, and if so we
434 * just return -EAGAIN.
436 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
438 if (q->bufs[buffer] == NULL)
440 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
441 dprintk(1, "preparing buffers, cannot free\n");
446 /* Call driver-provided cleanup function for each buffer, if provided */
447 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
449 struct vb2_buffer *vb = q->bufs[buffer];
451 if (vb && vb->planes[0].mem_priv)
452 call_void_vb_qop(vb, buf_cleanup, vb);
455 /* Release video buffer memory */
456 __vb2_free_mem(q, buffers);
458 #ifdef CONFIG_VIDEO_ADV_DEBUG
460 * Check that all the calls were balances during the life-time of this
461 * queue. If not (or if the debug level is 1 or up), then dump the
462 * counters to the kernel log.
464 if (q->num_buffers) {
465 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
466 q->cnt_wait_prepare != q->cnt_wait_finish;
468 if (unbalanced || debug) {
469 pr_info("vb2: counters for queue %p:%s\n", q,
470 unbalanced ? " UNBALANCED!" : "");
471 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
472 q->cnt_queue_setup, q->cnt_start_streaming,
473 q->cnt_stop_streaming);
474 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
475 q->cnt_wait_prepare, q->cnt_wait_finish);
477 q->cnt_queue_setup = 0;
478 q->cnt_wait_prepare = 0;
479 q->cnt_wait_finish = 0;
480 q->cnt_start_streaming = 0;
481 q->cnt_stop_streaming = 0;
483 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
484 struct vb2_buffer *vb = q->bufs[buffer];
485 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
486 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
487 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
488 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
489 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
490 vb->cnt_buf_queue != vb->cnt_buf_done ||
491 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
492 vb->cnt_buf_init != vb->cnt_buf_cleanup;
494 if (unbalanced || debug) {
495 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
496 q, buffer, unbalanced ? " UNBALANCED!" : "");
497 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
498 vb->cnt_buf_init, vb->cnt_buf_cleanup,
499 vb->cnt_buf_prepare, vb->cnt_buf_finish);
500 pr_info("vb2: buf_queue: %u buf_done: %u\n",
501 vb->cnt_buf_queue, vb->cnt_buf_done);
502 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
503 vb->cnt_mem_alloc, vb->cnt_mem_put,
504 vb->cnt_mem_prepare, vb->cnt_mem_finish,
506 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
507 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
508 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
509 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
510 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
511 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
512 vb->cnt_mem_get_dmabuf,
513 vb->cnt_mem_num_users,
520 /* Free videobuf buffers */
521 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
523 kfree(q->bufs[buffer]);
524 q->bufs[buffer] = NULL;
527 q->num_buffers -= buffers;
528 if (!q->num_buffers) {
530 INIT_LIST_HEAD(&q->queued_list);
535 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
538 for (plane = 0; plane < vb->num_planes; ++plane) {
539 void *mem_priv = vb->planes[plane].mem_priv;
541 * If num_users() has not been provided, call_memop
542 * will return 0, apparently nobody cares about this
543 * case anyway. If num_users() returns more than 1,
544 * we are not the only user of the plane's memory.
546 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
551 EXPORT_SYMBOL(vb2_buffer_in_use);
554 * __buffers_in_use() - return true if any buffers on the queue are in use and
555 * the queue cannot be freed (by the means of REQBUFS(0)) call
557 static bool __buffers_in_use(struct vb2_queue *q)
560 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
561 if (vb2_buffer_in_use(q, q->bufs[buffer]))
567 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
569 call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
571 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
574 * __verify_userptr_ops() - verify that all memory operations required for
575 * USERPTR queue type have been provided
577 static int __verify_userptr_ops(struct vb2_queue *q)
579 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
580 !q->mem_ops->put_userptr)
587 * __verify_mmap_ops() - verify that all memory operations required for
588 * MMAP queue type have been provided
590 static int __verify_mmap_ops(struct vb2_queue *q)
592 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
593 !q->mem_ops->put || !q->mem_ops->mmap)
600 * __verify_dmabuf_ops() - verify that all memory operations required for
601 * DMABUF queue type have been provided
603 static int __verify_dmabuf_ops(struct vb2_queue *q)
605 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
606 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
607 !q->mem_ops->unmap_dmabuf)
613 int vb2_verify_memory_type(struct vb2_queue *q,
614 enum vb2_memory memory, unsigned int type)
616 if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
617 memory != VB2_MEMORY_DMABUF) {
618 dprintk(1, "unsupported memory type\n");
622 if (type != q->type) {
623 dprintk(1, "requested type is incorrect\n");
628 * Make sure all the required memory ops for given memory type
631 if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
632 dprintk(1, "MMAP for current setup unsupported\n");
636 if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
637 dprintk(1, "USERPTR for current setup unsupported\n");
641 if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
642 dprintk(1, "DMABUF for current setup unsupported\n");
647 * Place the busy tests at the end: -EBUSY can be ignored when
648 * create_bufs is called with count == 0, but count == 0 should still
649 * do the memory and type validation.
651 if (vb2_fileio_is_active(q)) {
652 dprintk(1, "file io in progress\n");
657 EXPORT_SYMBOL(vb2_verify_memory_type);
659 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
662 unsigned int num_buffers, allocated_buffers, num_planes = 0;
663 unsigned plane_sizes[VB2_MAX_PLANES] = { };
667 dprintk(1, "streaming active\n");
671 if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
673 * We already have buffers allocated, so first check if they
674 * are not in use and can be freed.
676 mutex_lock(&q->mmap_lock);
677 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
678 mutex_unlock(&q->mmap_lock);
679 dprintk(1, "memory in use, cannot free\n");
684 * Call queue_cancel to clean up any buffers in the PREPARED or
685 * QUEUED state which is possible if buffers were prepared or
686 * queued without ever calling STREAMON.
688 __vb2_queue_cancel(q);
689 ret = __vb2_queue_free(q, q->num_buffers);
690 mutex_unlock(&q->mmap_lock);
695 * In case of REQBUFS(0) return immediately without calling
696 * driver's queue_setup() callback and allocating resources.
703 * Make sure the requested values and current defaults are sane.
705 num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
706 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
707 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
711 * Ask the driver how many buffers and planes per buffer it requires.
712 * Driver also sets the size and allocator context for each plane.
714 ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
715 plane_sizes, q->alloc_devs);
719 /* Finally, allocate buffers and video memory */
721 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
722 if (allocated_buffers == 0) {
723 dprintk(1, "memory allocation failed\n");
728 * There is no point in continuing if we can't allocate the minimum
729 * number of buffers needed by this vb2_queue.
731 if (allocated_buffers < q->min_buffers_needed)
735 * Check if driver can handle the allocated number of buffers.
737 if (!ret && allocated_buffers < num_buffers) {
738 num_buffers = allocated_buffers;
740 * num_planes is set by the previous queue_setup(), but since it
741 * signals to queue_setup() whether it is called from create_bufs()
742 * vs reqbufs() we zero it here to signal that queue_setup() is
743 * called for the reqbufs() case.
747 ret = call_qop(q, queue_setup, q, &num_buffers,
748 &num_planes, plane_sizes, q->alloc_devs);
750 if (!ret && allocated_buffers < num_buffers)
754 * Either the driver has accepted a smaller number of buffers,
755 * or .queue_setup() returned an error
759 mutex_lock(&q->mmap_lock);
760 q->num_buffers = allocated_buffers;
764 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
765 * from q->num_buffers.
767 __vb2_queue_free(q, allocated_buffers);
768 mutex_unlock(&q->mmap_lock);
771 mutex_unlock(&q->mmap_lock);
774 * Return the number of successfully allocated buffers
777 *count = allocated_buffers;
778 q->waiting_for_buffers = !q->is_output;
782 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
784 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
785 unsigned int *count, unsigned requested_planes,
786 const unsigned requested_sizes[])
788 unsigned int num_planes = 0, num_buffers, allocated_buffers;
789 unsigned plane_sizes[VB2_MAX_PLANES] = { };
792 if (q->num_buffers == VB2_MAX_FRAME) {
793 dprintk(1, "maximum number of buffers already allocated\n");
797 if (!q->num_buffers) {
798 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
800 q->waiting_for_buffers = !q->is_output;
803 num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
805 if (requested_planes && requested_sizes) {
806 num_planes = requested_planes;
807 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
811 * Ask the driver, whether the requested number of buffers, planes per
812 * buffer and their sizes are acceptable
814 ret = call_qop(q, queue_setup, q, &num_buffers,
815 &num_planes, plane_sizes, q->alloc_devs);
819 /* Finally, allocate buffers and video memory */
820 allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
821 num_planes, plane_sizes);
822 if (allocated_buffers == 0) {
823 dprintk(1, "memory allocation failed\n");
828 * Check if driver can handle the so far allocated number of buffers.
830 if (allocated_buffers < num_buffers) {
831 num_buffers = allocated_buffers;
834 * q->num_buffers contains the total number of buffers, that the
835 * queue driver has set up
837 ret = call_qop(q, queue_setup, q, &num_buffers,
838 &num_planes, plane_sizes, q->alloc_devs);
840 if (!ret && allocated_buffers < num_buffers)
844 * Either the driver has accepted a smaller number of buffers,
845 * or .queue_setup() returned an error
849 mutex_lock(&q->mmap_lock);
850 q->num_buffers += allocated_buffers;
854 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
855 * from q->num_buffers.
857 __vb2_queue_free(q, allocated_buffers);
858 mutex_unlock(&q->mmap_lock);
861 mutex_unlock(&q->mmap_lock);
864 * Return the number of successfully allocated buffers
867 *count = allocated_buffers;
871 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
873 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
875 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
878 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
881 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
883 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
885 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
888 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
890 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
892 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
894 struct vb2_queue *q = vb->vb2_queue;
898 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
901 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
902 state != VB2_BUF_STATE_ERROR &&
903 state != VB2_BUF_STATE_QUEUED &&
904 state != VB2_BUF_STATE_REQUEUEING))
905 state = VB2_BUF_STATE_ERROR;
907 #ifdef CONFIG_VIDEO_ADV_DEBUG
909 * Although this is not a callback, it still does have to balance
910 * with the buf_queue op. So update this counter manually.
914 dprintk(4, "done processing on buffer %d, state: %d\n",
918 for (plane = 0; plane < vb->num_planes; ++plane)
919 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
921 spin_lock_irqsave(&q->done_lock, flags);
922 if (state == VB2_BUF_STATE_QUEUED ||
923 state == VB2_BUF_STATE_REQUEUEING) {
924 vb->state = VB2_BUF_STATE_QUEUED;
926 /* Add the buffer to the done buffers list */
927 list_add_tail(&vb->done_entry, &q->done_list);
930 atomic_dec(&q->owned_by_drv_count);
931 spin_unlock_irqrestore(&q->done_lock, flags);
933 trace_vb2_buf_done(q, vb);
936 case VB2_BUF_STATE_QUEUED:
938 case VB2_BUF_STATE_REQUEUEING:
939 if (q->start_streaming_called)
940 __enqueue_in_driver(vb);
943 /* Inform any processes that may be waiting for buffers */
944 wake_up(&q->done_wq);
948 EXPORT_SYMBOL_GPL(vb2_buffer_done);
950 void vb2_discard_done(struct vb2_queue *q)
952 struct vb2_buffer *vb;
955 spin_lock_irqsave(&q->done_lock, flags);
956 list_for_each_entry(vb, &q->done_list, done_entry)
957 vb->state = VB2_BUF_STATE_ERROR;
958 spin_unlock_irqrestore(&q->done_lock, flags);
960 EXPORT_SYMBOL_GPL(vb2_discard_done);
963 * __qbuf_mmap() - handle qbuf of an MMAP buffer
965 static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
970 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
972 return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
976 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
978 static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
980 struct vb2_plane planes[VB2_MAX_PLANES];
981 struct vb2_queue *q = vb->vb2_queue;
985 enum dma_data_direction dma_dir =
986 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
987 bool reacquired = vb->planes[0].mem_priv == NULL;
989 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
990 /* Copy relevant information provided by the userspace */
992 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
997 for (plane = 0; plane < vb->num_planes; ++plane) {
998 /* Skip the plane if already verified */
999 if (vb->planes[plane].m.userptr &&
1000 vb->planes[plane].m.userptr == planes[plane].m.userptr
1001 && vb->planes[plane].length == planes[plane].length)
1004 dprintk(3, "userspace address for plane %d changed, "
1005 "reacquiring memory\n", plane);
1007 /* Check if the provided plane buffer is large enough */
1008 if (planes[plane].length < vb->planes[plane].min_length) {
1009 dprintk(1, "provided buffer size %u is less than "
1010 "setup size %u for plane %d\n",
1011 planes[plane].length,
1012 vb->planes[plane].min_length,
1018 /* Release previously acquired memory if present */
1019 if (vb->planes[plane].mem_priv) {
1022 call_void_vb_qop(vb, buf_cleanup, vb);
1024 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1027 vb->planes[plane].mem_priv = NULL;
1028 vb->planes[plane].bytesused = 0;
1029 vb->planes[plane].length = 0;
1030 vb->planes[plane].m.userptr = 0;
1031 vb->planes[plane].data_offset = 0;
1033 /* Acquire each plane's memory */
1034 mem_priv = call_ptr_memop(vb, get_userptr,
1035 q->alloc_devs[plane] ? : q->dev,
1036 planes[plane].m.userptr,
1037 planes[plane].length, dma_dir);
1038 if (IS_ERR(mem_priv)) {
1039 dprintk(1, "failed acquiring userspace "
1040 "memory for plane %d\n", plane);
1041 ret = PTR_ERR(mem_priv);
1044 vb->planes[plane].mem_priv = mem_priv;
1048 * Now that everything is in order, copy relevant information
1049 * provided by userspace.
1051 for (plane = 0; plane < vb->num_planes; ++plane) {
1052 vb->planes[plane].bytesused = planes[plane].bytesused;
1053 vb->planes[plane].length = planes[plane].length;
1054 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1055 vb->planes[plane].data_offset = planes[plane].data_offset;
1060 * One or more planes changed, so we must call buf_init to do
1061 * the driver-specific initialization on the newly acquired
1062 * buffer, if provided.
1064 ret = call_vb_qop(vb, buf_init, vb);
1066 dprintk(1, "buffer initialization failed\n");
1071 ret = call_vb_qop(vb, buf_prepare, vb);
1073 dprintk(1, "buffer preparation failed\n");
1074 call_void_vb_qop(vb, buf_cleanup, vb);
1080 /* In case of errors, release planes that were already acquired */
1081 for (plane = 0; plane < vb->num_planes; ++plane) {
1082 if (vb->planes[plane].mem_priv)
1083 call_void_memop(vb, put_userptr,
1084 vb->planes[plane].mem_priv);
1085 vb->planes[plane].mem_priv = NULL;
1086 vb->planes[plane].m.userptr = 0;
1087 vb->planes[plane].length = 0;
1094 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1096 static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
1098 struct vb2_plane planes[VB2_MAX_PLANES];
1099 struct vb2_queue *q = vb->vb2_queue;
1103 enum dma_data_direction dma_dir =
1104 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1105 bool reacquired = vb->planes[0].mem_priv == NULL;
1107 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1108 /* Copy relevant information provided by the userspace */
1110 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1115 for (plane = 0; plane < vb->num_planes; ++plane) {
1116 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1118 if (IS_ERR_OR_NULL(dbuf)) {
1119 dprintk(1, "invalid dmabuf fd for plane %d\n",
1125 /* use DMABUF size if length is not provided */
1126 if (planes[plane].length == 0)
1127 planes[plane].length = dbuf->size;
1129 if (planes[plane].length < vb->planes[plane].min_length) {
1130 dprintk(1, "invalid dmabuf length %u for plane %d, "
1131 "minimum length %u\n",
1132 planes[plane].length, plane,
1133 vb->planes[plane].min_length);
1139 /* Skip the plane if already verified */
1140 if (dbuf == vb->planes[plane].dbuf &&
1141 vb->planes[plane].length == planes[plane].length) {
1146 dprintk(1, "buffer for plane %d changed\n", plane);
1150 call_void_vb_qop(vb, buf_cleanup, vb);
1153 /* Release previously acquired memory if present */
1154 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1155 vb->planes[plane].bytesused = 0;
1156 vb->planes[plane].length = 0;
1157 vb->planes[plane].m.fd = 0;
1158 vb->planes[plane].data_offset = 0;
1160 /* Acquire each plane's memory */
1161 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1162 q->alloc_devs[plane] ? : q->dev,
1163 dbuf, planes[plane].length, dma_dir);
1164 if (IS_ERR(mem_priv)) {
1165 dprintk(1, "failed to attach dmabuf\n");
1166 ret = PTR_ERR(mem_priv);
1171 vb->planes[plane].dbuf = dbuf;
1172 vb->planes[plane].mem_priv = mem_priv;
1176 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1177 * here instead just before the DMA, while queueing the buffer(s) so
1178 * userspace knows sooner rather than later if the dma-buf map fails.
1180 for (plane = 0; plane < vb->num_planes; ++plane) {
1181 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1183 dprintk(1, "failed to map dmabuf for plane %d\n",
1187 vb->planes[plane].dbuf_mapped = 1;
1191 * Now that everything is in order, copy relevant information
1192 * provided by userspace.
1194 for (plane = 0; plane < vb->num_planes; ++plane) {
1195 vb->planes[plane].bytesused = planes[plane].bytesused;
1196 vb->planes[plane].length = planes[plane].length;
1197 vb->planes[plane].m.fd = planes[plane].m.fd;
1198 vb->planes[plane].data_offset = planes[plane].data_offset;
1203 * Call driver-specific initialization on the newly acquired buffer,
1206 ret = call_vb_qop(vb, buf_init, vb);
1208 dprintk(1, "buffer initialization failed\n");
1213 ret = call_vb_qop(vb, buf_prepare, vb);
1215 dprintk(1, "buffer preparation failed\n");
1216 call_void_vb_qop(vb, buf_cleanup, vb);
1222 /* In case of errors, release planes that were already acquired */
1223 __vb2_buf_dmabuf_put(vb);
1229 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1231 static void __enqueue_in_driver(struct vb2_buffer *vb)
1233 struct vb2_queue *q = vb->vb2_queue;
1236 vb->state = VB2_BUF_STATE_ACTIVE;
1237 atomic_inc(&q->owned_by_drv_count);
1239 trace_vb2_buf_queue(q, vb);
1242 for (plane = 0; plane < vb->num_planes; ++plane)
1243 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1245 call_void_vb_qop(vb, buf_queue, vb);
1248 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1250 struct vb2_queue *q = vb->vb2_queue;
1254 dprintk(1, "fatal error occurred on queue\n");
1258 vb->state = VB2_BUF_STATE_PREPARING;
1260 switch (q->memory) {
1261 case VB2_MEMORY_MMAP:
1262 ret = __qbuf_mmap(vb, pb);
1264 case VB2_MEMORY_USERPTR:
1265 ret = __qbuf_userptr(vb, pb);
1267 case VB2_MEMORY_DMABUF:
1268 ret = __qbuf_dmabuf(vb, pb);
1271 WARN(1, "Invalid queue type\n");
1276 dprintk(1, "buffer preparation failed: %d\n", ret);
1277 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1282 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1284 struct vb2_buffer *vb;
1287 vb = q->bufs[index];
1288 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1289 dprintk(1, "invalid buffer state %d\n",
1294 ret = __buf_prepare(vb, pb);
1298 /* Fill buffer information for the userspace */
1299 call_void_bufop(q, fill_user_buffer, vb, pb);
1301 dprintk(1, "prepare of buffer %d succeeded\n", vb->index);
1305 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1308 * vb2_start_streaming() - Attempt to start streaming.
1309 * @q: videobuf2 queue
1311 * Attempt to start streaming. When this function is called there must be
1312 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1313 * number of buffers required for the DMA engine to function). If the
1314 * @start_streaming op fails it is supposed to return all the driver-owned
1315 * buffers back to vb2 in state QUEUED. Check if that happened and if
1316 * not warn and reclaim them forcefully.
1318 static int vb2_start_streaming(struct vb2_queue *q)
1320 struct vb2_buffer *vb;
1324 * If any buffers were queued before streamon,
1325 * we can now pass them to driver for processing.
1327 list_for_each_entry(vb, &q->queued_list, queued_entry)
1328 __enqueue_in_driver(vb);
1330 /* Tell the driver to start streaming */
1331 q->start_streaming_called = 1;
1332 ret = call_qop(q, start_streaming, q,
1333 atomic_read(&q->owned_by_drv_count));
1337 q->start_streaming_called = 0;
1339 dprintk(1, "driver refused to start streaming\n");
1341 * If you see this warning, then the driver isn't cleaning up properly
1342 * after a failed start_streaming(). See the start_streaming()
1343 * documentation in videobuf2-core.h for more information how buffers
1344 * should be returned to vb2 in start_streaming().
1346 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1350 * Forcefully reclaim buffers if the driver did not
1351 * correctly return them to vb2.
1353 for (i = 0; i < q->num_buffers; ++i) {
1355 if (vb->state == VB2_BUF_STATE_ACTIVE)
1356 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1358 /* Must be zero now */
1359 WARN_ON(atomic_read(&q->owned_by_drv_count));
1362 * If done_list is not empty, then start_streaming() didn't call
1363 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1366 WARN_ON(!list_empty(&q->done_list));
1370 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1372 struct vb2_buffer *vb;
1373 enum vb2_buffer_state orig_state;
1377 dprintk(1, "fatal error occurred on queue\n");
1381 vb = q->bufs[index];
1383 switch (vb->state) {
1384 case VB2_BUF_STATE_DEQUEUED:
1385 ret = __buf_prepare(vb, pb);
1389 case VB2_BUF_STATE_PREPARED:
1391 case VB2_BUF_STATE_PREPARING:
1392 dprintk(1, "buffer still being prepared\n");
1395 dprintk(1, "invalid buffer state %d\n", vb->state);
1400 * Add to the queued buffers list, a buffer will stay on it until
1401 * dequeued in dqbuf.
1403 orig_state = vb->state;
1404 list_add_tail(&vb->queued_entry, &q->queued_list);
1406 q->waiting_for_buffers = false;
1407 vb->state = VB2_BUF_STATE_QUEUED;
1410 call_void_bufop(q, copy_timestamp, vb, pb);
1412 trace_vb2_qbuf(q, vb);
1415 * If already streaming, give the buffer to driver for processing.
1416 * If not, the buffer will be given to driver on next streamon.
1418 if (q->start_streaming_called)
1419 __enqueue_in_driver(vb);
1421 /* Fill buffer information for the userspace */
1423 call_void_bufop(q, fill_user_buffer, vb, pb);
1426 * If streamon has been called, and we haven't yet called
1427 * start_streaming() since not enough buffers were queued, and
1428 * we now have reached the minimum number of queued buffers,
1429 * then we can finally call start_streaming().
1431 if (q->streaming && !q->start_streaming_called &&
1432 q->queued_count >= q->min_buffers_needed) {
1433 ret = vb2_start_streaming(q);
1436 * Since vb2_core_qbuf will return with an error,
1437 * we should return it to state DEQUEUED since
1438 * the error indicates that the buffer wasn't queued.
1440 list_del(&vb->queued_entry);
1442 vb->state = orig_state;
1447 dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
1450 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1453 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1456 * Will sleep if required for nonblocking == false.
1458 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1461 * All operations on vb_done_list are performed under done_lock
1462 * spinlock protection. However, buffers may be removed from
1463 * it and returned to userspace only while holding both driver's
1464 * lock and the done_lock spinlock. Thus we can be sure that as
1465 * long as we hold the driver's lock, the list will remain not
1466 * empty if list_empty() check succeeds.
1472 if (!q->streaming) {
1473 dprintk(1, "streaming off, will not wait for buffers\n");
1478 dprintk(1, "Queue in error state, will not wait for buffers\n");
1482 if (q->last_buffer_dequeued) {
1483 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1487 if (!list_empty(&q->done_list)) {
1489 * Found a buffer that we were waiting for.
1495 dprintk(1, "nonblocking and no buffers to dequeue, "
1501 * We are streaming and blocking, wait for another buffer to
1502 * become ready or for streamoff. Driver's lock is released to
1503 * allow streamoff or qbuf to be called while waiting.
1505 call_void_qop(q, wait_prepare, q);
1508 * All locks have been released, it is safe to sleep now.
1510 dprintk(3, "will sleep waiting for buffers\n");
1511 ret = wait_event_interruptible(q->done_wq,
1512 !list_empty(&q->done_list) || !q->streaming ||
1516 * We need to reevaluate both conditions again after reacquiring
1517 * the locks or return an error if one occurred.
1519 call_void_qop(q, wait_finish, q);
1521 dprintk(1, "sleep was interrupted\n");
1529 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1531 * Will sleep if required for nonblocking == false.
1533 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1534 void *pb, int nonblocking)
1536 unsigned long flags;
1540 * Wait for at least one buffer to become available on the done_list.
1542 ret = __vb2_wait_for_done_vb(q, nonblocking);
1547 * Driver's lock has been held since we last verified that done_list
1548 * is not empty, so no need for another list_empty(done_list) check.
1550 spin_lock_irqsave(&q->done_lock, flags);
1551 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1553 * Only remove the buffer from done_list if all planes can be
1554 * handled. Some cases such as V4L2 file I/O and DVB have pb
1555 * == NULL; skip the check then as there's nothing to verify.
1558 ret = call_bufop(q, verify_planes_array, *vb, pb);
1560 list_del(&(*vb)->done_entry);
1561 spin_unlock_irqrestore(&q->done_lock, flags);
1566 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1568 if (!q->streaming) {
1569 dprintk(1, "streaming off, will not wait for buffers\n");
1573 if (q->start_streaming_called)
1574 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1577 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1580 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1582 static void __vb2_dqbuf(struct vb2_buffer *vb)
1584 struct vb2_queue *q = vb->vb2_queue;
1587 /* nothing to do if the buffer is already dequeued */
1588 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1591 vb->state = VB2_BUF_STATE_DEQUEUED;
1593 /* unmap DMABUF buffer */
1594 if (q->memory == VB2_MEMORY_DMABUF)
1595 for (i = 0; i < vb->num_planes; ++i) {
1596 if (!vb->planes[i].dbuf_mapped)
1598 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1599 vb->planes[i].dbuf_mapped = 0;
1603 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1606 struct vb2_buffer *vb = NULL;
1609 ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1613 switch (vb->state) {
1614 case VB2_BUF_STATE_DONE:
1615 dprintk(3, "returning done buffer\n");
1617 case VB2_BUF_STATE_ERROR:
1618 dprintk(3, "returning done buffer with errors\n");
1621 dprintk(1, "invalid buffer state\n");
1625 call_void_vb_qop(vb, buf_finish, vb);
1628 *pindex = vb->index;
1630 /* Fill buffer information for the userspace */
1632 call_void_bufop(q, fill_user_buffer, vb, pb);
1634 /* Remove from videobuf queue */
1635 list_del(&vb->queued_entry);
1638 trace_vb2_dqbuf(q, vb);
1640 /* go back to dequeued state */
1643 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1644 vb->index, vb->state);
1649 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1652 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1654 * Removes all queued buffers from driver's queue and all buffers queued by
1655 * userspace from videobuf's queue. Returns to state after reqbufs.
1657 static void __vb2_queue_cancel(struct vb2_queue *q)
1662 * Tell driver to stop all transactions and release all queued
1665 if (q->start_streaming_called)
1666 call_void_qop(q, stop_streaming, q);
1669 * If you see this warning, then the driver isn't cleaning up properly
1670 * in stop_streaming(). See the stop_streaming() documentation in
1671 * videobuf2-core.h for more information how buffers should be returned
1672 * to vb2 in stop_streaming().
1674 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1675 for (i = 0; i < q->num_buffers; ++i)
1676 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1677 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1678 /* Must be zero now */
1679 WARN_ON(atomic_read(&q->owned_by_drv_count));
1683 q->start_streaming_called = 0;
1684 q->queued_count = 0;
1688 * Remove all buffers from videobuf's list...
1690 INIT_LIST_HEAD(&q->queued_list);
1692 * ...and done list; userspace will not receive any buffers it
1693 * has not already dequeued before initiating cancel.
1695 INIT_LIST_HEAD(&q->done_list);
1696 atomic_set(&q->owned_by_drv_count, 0);
1697 wake_up_all(&q->done_wq);
1700 * Reinitialize all buffers for next use.
1701 * Make sure to call buf_finish for any queued buffers. Normally
1702 * that's done in dqbuf, but that's not going to happen when we
1703 * cancel the whole queue. Note: this code belongs here, not in
1704 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1705 * call to __fill_user_buffer() after buf_finish(). That order can't
1706 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1708 for (i = 0; i < q->num_buffers; ++i) {
1709 struct vb2_buffer *vb = q->bufs[i];
1711 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1712 vb->state = VB2_BUF_STATE_PREPARED;
1713 call_void_vb_qop(vb, buf_finish, vb);
1719 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1723 if (type != q->type) {
1724 dprintk(1, "invalid stream type\n");
1729 dprintk(3, "already streaming\n");
1733 if (!q->num_buffers) {
1734 dprintk(1, "no buffers have been allocated\n");
1738 if (q->num_buffers < q->min_buffers_needed) {
1739 dprintk(1, "need at least %u allocated buffers\n",
1740 q->min_buffers_needed);
1745 * Tell driver to start streaming provided sufficient buffers
1748 if (q->queued_count >= q->min_buffers_needed) {
1749 ret = v4l_vb2q_enable_media_source(q);
1752 ret = vb2_start_streaming(q);
1754 __vb2_queue_cancel(q);
1761 dprintk(3, "successful\n");
1764 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1766 void vb2_queue_error(struct vb2_queue *q)
1770 wake_up_all(&q->done_wq);
1772 EXPORT_SYMBOL_GPL(vb2_queue_error);
1774 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1776 if (type != q->type) {
1777 dprintk(1, "invalid stream type\n");
1782 * Cancel will pause streaming and remove all buffers from the driver
1783 * and videobuf, effectively returning control over them to userspace.
1785 * Note that we do this even if q->streaming == 0: if you prepare or
1786 * queue buffers, and then call streamoff without ever having called
1787 * streamon, you would still expect those buffers to be returned to
1788 * their normal dequeued state.
1790 __vb2_queue_cancel(q);
1791 q->waiting_for_buffers = !q->is_output;
1792 q->last_buffer_dequeued = false;
1794 dprintk(3, "successful\n");
1797 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1800 * __find_plane_by_offset() - find plane associated with the given offset off
1802 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1803 unsigned int *_buffer, unsigned int *_plane)
1805 struct vb2_buffer *vb;
1806 unsigned int buffer, plane;
1809 * Go over all buffers and their planes, comparing the given offset
1810 * with an offset assigned to each plane. If a match is found,
1811 * return its buffer and plane numbers.
1813 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1814 vb = q->bufs[buffer];
1816 for (plane = 0; plane < vb->num_planes; ++plane) {
1817 if (vb->planes[plane].m.offset == off) {
1828 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1829 unsigned int index, unsigned int plane, unsigned int flags)
1831 struct vb2_buffer *vb = NULL;
1832 struct vb2_plane *vb_plane;
1834 struct dma_buf *dbuf;
1836 if (q->memory != VB2_MEMORY_MMAP) {
1837 dprintk(1, "queue is not currently set up for mmap\n");
1841 if (!q->mem_ops->get_dmabuf) {
1842 dprintk(1, "queue does not support DMA buffer exporting\n");
1846 if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1847 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1851 if (type != q->type) {
1852 dprintk(1, "invalid buffer type\n");
1856 if (index >= q->num_buffers) {
1857 dprintk(1, "buffer index out of range\n");
1861 vb = q->bufs[index];
1863 if (plane >= vb->num_planes) {
1864 dprintk(1, "buffer plane out of range\n");
1868 if (vb2_fileio_is_active(q)) {
1869 dprintk(1, "expbuf: file io in progress\n");
1873 vb_plane = &vb->planes[plane];
1875 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1877 if (IS_ERR_OR_NULL(dbuf)) {
1878 dprintk(1, "failed to export buffer %d, plane %d\n",
1883 ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1885 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1891 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1897 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1899 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1901 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1902 struct vb2_buffer *vb;
1903 unsigned int buffer = 0, plane = 0;
1905 unsigned long length;
1907 if (q->memory != VB2_MEMORY_MMAP) {
1908 dprintk(1, "queue is not currently set up for mmap\n");
1913 * Check memory area access mode.
1915 if (!(vma->vm_flags & VM_SHARED)) {
1916 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1920 if (!(vma->vm_flags & VM_WRITE)) {
1921 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1925 if (!(vma->vm_flags & VM_READ)) {
1926 dprintk(1, "invalid vma flags, VM_READ needed\n");
1931 mutex_lock(&q->mmap_lock);
1933 if (vb2_fileio_is_active(q)) {
1934 dprintk(1, "mmap: file io in progress\n");
1940 * Find the plane corresponding to the offset passed by userspace.
1942 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1946 vb = q->bufs[buffer];
1949 * MMAP requires page_aligned buffers.
1950 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1951 * so, we need to do the same here.
1953 length = PAGE_ALIGN(vb->planes[plane].length);
1954 if (length < (vma->vm_end - vma->vm_start)) {
1956 "MMAP invalid, as it would overflow buffer length\n");
1961 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1964 mutex_unlock(&q->mmap_lock);
1968 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1971 EXPORT_SYMBOL_GPL(vb2_mmap);
1974 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1977 unsigned long pgoff,
1978 unsigned long flags)
1980 unsigned long off = pgoff << PAGE_SHIFT;
1981 struct vb2_buffer *vb;
1982 unsigned int buffer, plane;
1986 if (q->memory != VB2_MEMORY_MMAP) {
1987 dprintk(1, "queue is not currently set up for mmap\n");
1992 * Find the plane corresponding to the offset passed by userspace.
1994 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1998 vb = q->bufs[buffer];
2000 vaddr = vb2_plane_vaddr(vb, plane);
2001 return vaddr ? (unsigned long)vaddr : -EINVAL;
2003 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2006 int vb2_core_queue_init(struct vb2_queue *q)
2013 WARN_ON(!q->mem_ops) ||
2014 WARN_ON(!q->type) ||
2015 WARN_ON(!q->io_modes) ||
2016 WARN_ON(!q->ops->queue_setup) ||
2017 WARN_ON(!q->ops->buf_queue))
2020 INIT_LIST_HEAD(&q->queued_list);
2021 INIT_LIST_HEAD(&q->done_list);
2022 spin_lock_init(&q->done_lock);
2023 mutex_init(&q->mmap_lock);
2024 init_waitqueue_head(&q->done_wq);
2026 if (q->buf_struct_size == 0)
2027 q->buf_struct_size = sizeof(struct vb2_buffer);
2031 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2033 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2034 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2035 void vb2_core_queue_release(struct vb2_queue *q)
2037 __vb2_cleanup_fileio(q);
2038 __vb2_queue_cancel(q);
2039 mutex_lock(&q->mmap_lock);
2040 __vb2_queue_free(q, q->num_buffers);
2041 mutex_unlock(&q->mmap_lock);
2043 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2045 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
2048 unsigned long req_events = poll_requested_events(wait);
2049 struct vb2_buffer *vb = NULL;
2050 unsigned long flags;
2052 if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2054 if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2058 * Start file I/O emulator only if streaming API has not been used yet.
2060 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2061 if (!q->is_output && (q->io_modes & VB2_READ) &&
2062 (req_events & (POLLIN | POLLRDNORM))) {
2063 if (__vb2_init_fileio(q, 1))
2066 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2067 (req_events & (POLLOUT | POLLWRNORM))) {
2068 if (__vb2_init_fileio(q, 0))
2071 * Write to OUTPUT queue can be done immediately.
2073 return POLLOUT | POLLWRNORM;
2078 * There is nothing to wait for if the queue isn't streaming, or if the
2079 * error flag is set.
2081 if (!vb2_is_streaming(q) || q->error)
2085 * If this quirk is set and QBUF hasn't been called yet then
2086 * return POLLERR as well. This only affects capture queues, output
2087 * queues will always initialize waiting_for_buffers to false.
2088 * This quirk is set by V4L2 for backwards compatibility reasons.
2090 if (q->quirk_poll_must_check_waiting_for_buffers &&
2091 q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2095 * For output streams you can call write() as long as there are fewer
2096 * buffers queued than there are buffers available.
2098 if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2099 return POLLOUT | POLLWRNORM;
2101 if (list_empty(&q->done_list)) {
2103 * If the last buffer was dequeued from a capture queue,
2104 * return immediately. DQBUF will return -EPIPE.
2106 if (q->last_buffer_dequeued)
2107 return POLLIN | POLLRDNORM;
2109 poll_wait(file, &q->done_wq, wait);
2113 * Take first buffer available for dequeuing.
2115 spin_lock_irqsave(&q->done_lock, flags);
2116 if (!list_empty(&q->done_list))
2117 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2119 spin_unlock_irqrestore(&q->done_lock, flags);
2121 if (vb && (vb->state == VB2_BUF_STATE_DONE
2122 || vb->state == VB2_BUF_STATE_ERROR)) {
2123 return (q->is_output) ?
2124 POLLOUT | POLLWRNORM :
2125 POLLIN | POLLRDNORM;
2129 EXPORT_SYMBOL_GPL(vb2_core_poll);
2132 * struct vb2_fileio_buf - buffer context used by file io emulator
2134 * vb2 provides a compatibility layer and emulator of file io (read and
2135 * write) calls on top of streaming API. This structure is used for
2136 * tracking context related to the buffers.
2138 struct vb2_fileio_buf {
2142 unsigned int queued:1;
2146 * struct vb2_fileio_data - queue context used by file io emulator
2148 * @cur_index: the index of the buffer currently being read from or
2149 * written to. If equal to q->num_buffers then a new buffer
2151 * @initial_index: in the read() case all buffers are queued up immediately
2152 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2153 * buffers. However, in the write() case no buffers are initially
2154 * queued, instead whenever a buffer is full it is queued up by
2155 * __vb2_perform_fileio(). Only once all available buffers have
2156 * been queued up will __vb2_perform_fileio() start to dequeue
2157 * buffers. This means that initially __vb2_perform_fileio()
2158 * needs to know what buffer index to use when it is queuing up
2159 * the buffers for the first time. That initial index is stored
2160 * in this field. Once it is equal to q->num_buffers all
2161 * available buffers have been queued and __vb2_perform_fileio()
2162 * should start the normal dequeue/queue cycle.
2164 * vb2 provides a compatibility layer and emulator of file io (read and
2165 * write) calls on top of streaming API. For proper operation it required
2166 * this structure to save the driver state between each call of the read
2167 * or write function.
2169 struct vb2_fileio_data {
2172 unsigned int memory;
2173 struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2174 unsigned int cur_index;
2175 unsigned int initial_index;
2176 unsigned int q_count;
2177 unsigned int dq_count;
2178 unsigned read_once:1;
2179 unsigned write_immediately:1;
2183 * __vb2_init_fileio() - initialize file io emulator
2184 * @q: videobuf2 queue
2185 * @read: mode selector (1 means read, 0 means write)
2187 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2189 struct vb2_fileio_data *fileio;
2191 unsigned int count = 0;
2196 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2197 (!read && !(q->io_modes & VB2_WRITE))))
2201 * Check if device supports mapping buffers to kernel virtual space.
2203 if (!q->mem_ops->vaddr)
2207 * Check if streaming api has not been already activated.
2209 if (q->streaming || q->num_buffers > 0)
2213 * Start with count 1, driver can increase it in queue_setup()
2217 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2218 (read) ? "read" : "write", count, q->fileio_read_once,
2219 q->fileio_write_immediately);
2221 fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2225 fileio->read_once = q->fileio_read_once;
2226 fileio->write_immediately = q->fileio_write_immediately;
2229 * Request buffers and use MMAP type to force driver
2230 * to allocate buffers by itself.
2232 fileio->count = count;
2233 fileio->memory = VB2_MEMORY_MMAP;
2234 fileio->type = q->type;
2236 ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2241 * Check if plane_count is correct
2242 * (multiplane buffers are not supported).
2244 if (q->bufs[0]->num_planes != 1) {
2250 * Get kernel address of each buffer.
2252 for (i = 0; i < q->num_buffers; i++) {
2253 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2254 if (fileio->bufs[i].vaddr == NULL) {
2258 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2262 * Read mode requires pre queuing of all buffers.
2266 * Queue all buffers.
2268 for (i = 0; i < q->num_buffers; i++) {
2269 ret = vb2_core_qbuf(q, i, NULL);
2272 fileio->bufs[i].queued = 1;
2275 * All buffers have been queued, so mark that by setting
2276 * initial_index to q->num_buffers
2278 fileio->initial_index = q->num_buffers;
2279 fileio->cur_index = q->num_buffers;
2285 ret = vb2_core_streamon(q, q->type);
2293 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2302 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2303 * @q: videobuf2 queue
2305 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2307 struct vb2_fileio_data *fileio = q->fileio;
2310 vb2_core_streamoff(q, q->type);
2313 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2315 dprintk(3, "file io emulator closed\n");
2321 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2322 * @q: videobuf2 queue
2323 * @data: pointed to target userspace buffer
2324 * @count: number of bytes to read or write
2325 * @ppos: file handle position tracking pointer
2326 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2327 * @read: access mode selector (1 means read, 0 means write)
2329 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2330 loff_t *ppos, int nonblock, int read)
2332 struct vb2_fileio_data *fileio;
2333 struct vb2_fileio_buf *buf;
2334 bool is_multiplanar = q->is_multiplanar;
2336 * When using write() to write data to an output video node the vb2 core
2337 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2338 * else is able to provide this information with the write() operation.
2340 bool copy_timestamp = !read && q->copy_timestamp;
2344 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2345 read ? "read" : "write", (long)*ppos, count,
2346 nonblock ? "non" : "");
2352 * Initialize emulator on first call.
2354 if (!vb2_fileio_is_active(q)) {
2355 ret = __vb2_init_fileio(q, read);
2356 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2363 * Check if we need to dequeue the buffer.
2365 index = fileio->cur_index;
2366 if (index >= q->num_buffers) {
2367 struct vb2_buffer *b;
2370 * Call vb2_dqbuf to get buffer back.
2372 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2373 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2376 fileio->dq_count += 1;
2378 fileio->cur_index = index;
2379 buf = &fileio->bufs[index];
2383 * Get number of bytes filled by the driver
2387 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2388 : vb2_plane_size(q->bufs[index], 0);
2389 /* Compensate for data_offset on read in the multiplanar case. */
2390 if (is_multiplanar && read &&
2391 b->planes[0].data_offset < buf->size) {
2392 buf->pos = b->planes[0].data_offset;
2393 buf->size -= buf->pos;
2396 buf = &fileio->bufs[index];
2400 * Limit count on last few bytes of the buffer.
2402 if (buf->pos + count > buf->size) {
2403 count = buf->size - buf->pos;
2404 dprintk(5, "reducing read count: %zd\n", count);
2408 * Transfer data to userspace.
2410 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2411 count, index, buf->pos);
2413 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2415 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2417 dprintk(3, "error copying data\n");
2428 * Queue next buffer if required.
2430 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2431 struct vb2_buffer *b = q->bufs[index];
2434 * Check if this is the last buffer to read.
2436 if (read && fileio->read_once && fileio->dq_count == 1) {
2437 dprintk(3, "read limit reached\n");
2438 return __vb2_cleanup_fileio(q);
2442 * Call vb2_qbuf and give buffer to the driver.
2444 b->planes[0].bytesused = buf->pos;
2447 b->timestamp = ktime_get_ns();
2448 ret = vb2_core_qbuf(q, index, NULL);
2449 dprintk(5, "vb2_dbuf result: %d\n", ret);
2454 * Buffer has been queued, update the status
2458 buf->size = vb2_plane_size(q->bufs[index], 0);
2459 fileio->q_count += 1;
2461 * If we are queuing up buffers for the first time, then
2462 * increase initial_index by one.
2464 if (fileio->initial_index < q->num_buffers)
2465 fileio->initial_index++;
2467 * The next buffer to use is either a buffer that's going to be
2468 * queued for the first time (initial_index < q->num_buffers)
2469 * or it is equal to q->num_buffers, meaning that the next
2470 * time we need to dequeue a buffer since we've now queued up
2471 * all the 'first time' buffers.
2473 fileio->cur_index = fileio->initial_index;
2477 * Return proper number of bytes processed.
2484 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2485 loff_t *ppos, int nonblocking)
2487 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2489 EXPORT_SYMBOL_GPL(vb2_read);
2491 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2492 loff_t *ppos, int nonblocking)
2494 return __vb2_perform_fileio(q, (char __user *) data, count,
2495 ppos, nonblocking, 0);
2497 EXPORT_SYMBOL_GPL(vb2_write);
2499 struct vb2_threadio_data {
2500 struct task_struct *thread;
2506 static int vb2_thread(void *data)
2508 struct vb2_queue *q = data;
2509 struct vb2_threadio_data *threadio = q->threadio;
2510 bool copy_timestamp = false;
2511 unsigned prequeue = 0;
2516 prequeue = q->num_buffers;
2517 copy_timestamp = q->copy_timestamp;
2523 struct vb2_buffer *vb;
2526 * Call vb2_dqbuf to get buffer back.
2529 vb = q->bufs[index++];
2532 call_void_qop(q, wait_finish, q);
2533 if (!threadio->stop)
2534 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2535 call_void_qop(q, wait_prepare, q);
2536 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2538 vb = q->bufs[index];
2540 if (ret || threadio->stop)
2544 if (vb->state != VB2_BUF_STATE_ERROR)
2545 if (threadio->fnc(vb, threadio->priv))
2547 call_void_qop(q, wait_finish, q);
2549 vb->timestamp = ktime_get_ns();;
2550 if (!threadio->stop)
2551 ret = vb2_core_qbuf(q, vb->index, NULL);
2552 call_void_qop(q, wait_prepare, q);
2553 if (ret || threadio->stop)
2557 /* Hmm, linux becomes *very* unhappy without this ... */
2558 while (!kthread_should_stop()) {
2559 set_current_state(TASK_INTERRUPTIBLE);
2566 * This function should not be used for anything else but the videobuf2-dvb
2567 * support. If you think you have another good use-case for this, then please
2568 * contact the linux-media mailinglist first.
2570 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2571 const char *thread_name)
2573 struct vb2_threadio_data *threadio;
2580 if (WARN_ON(q->fileio))
2583 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2584 if (threadio == NULL)
2586 threadio->fnc = fnc;
2587 threadio->priv = priv;
2589 ret = __vb2_init_fileio(q, !q->is_output);
2590 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2593 q->threadio = threadio;
2594 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2595 if (IS_ERR(threadio->thread)) {
2596 ret = PTR_ERR(threadio->thread);
2597 threadio->thread = NULL;
2603 __vb2_cleanup_fileio(q);
2608 EXPORT_SYMBOL_GPL(vb2_thread_start);
2610 int vb2_thread_stop(struct vb2_queue *q)
2612 struct vb2_threadio_data *threadio = q->threadio;
2615 if (threadio == NULL)
2617 threadio->stop = true;
2618 /* Wake up all pending sleeps in the thread */
2620 err = kthread_stop(threadio->thread);
2621 __vb2_cleanup_fileio(q);
2622 threadio->thread = NULL;
2627 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2629 MODULE_DESCRIPTION("Media buffer core framework");
2630 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2631 MODULE_LICENSE("GPL");