blob: c5d49d7a0d76d09c1ac5598a21ce7726d03190c1 [file] [log] [blame]
/*
* videobuf2-core.c - video buffer 2 core framework
*
* Copyright (C) 2010 Samsung Electronics
*
* Author: Pawel Osciak <pawel@osciak.com>
* Marek Szyprowski <m.szyprowski@samsung.com>
*
* The vb2_thread implementation was based on code from videobuf-dvb.c:
* (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <media/videobuf2-core.h>
#include <trace/events/vb2.h>
static int debug;
module_param(debug, int, 0644);
#define dprintk(level, fmt, arg...) \
do { \
if (debug >= level) \
pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
} while (0)
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
* If advanced debugging is on, then count how often each op is called
* successfully, which can either be per-buffer or per-queue.
*
* This makes it easy to check that the 'init' and 'cleanup'
* (and variations thereof) stay balanced.
*/
#define log_memop(vb, op) \
dprintk(2, "call_memop(%p, %d, %s)%s\n", \
(vb)->vb2_queue, (vb)->index, #op, \
(vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
#define call_memop(vb, op, args...) \
({ \
struct vb2_queue *_q = (vb)->vb2_queue; \
int err; \
\
log_memop(vb, op); \
err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
if (!err) \
(vb)->cnt_mem_ ## op++; \
err; \
})
#define call_ptr_memop(vb, op, args...) \
({ \
struct vb2_queue *_q = (vb)->vb2_queue; \
void *ptr; \
\
log_memop(vb, op); \
ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
if (!IS_ERR_OR_NULL(ptr)) \
(vb)->cnt_mem_ ## op++; \
ptr; \
})
#define call_void_memop(vb, op, args...) \
({ \
struct vb2_queue *_q = (vb)->vb2_queue; \
\
log_memop(vb, op); \
if (_q->mem_ops->op) \
_q->mem_ops->op(args); \
(vb)->cnt_mem_ ## op++; \
})
#define log_qop(q, op) \
dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
(q)->ops->op ? "" : " (nop)")
#define call_qop(q, op, args...) \
({ \
int err; \
\
log_qop(q, op); \
err = (q)->ops->op ? (q)->ops->op(args) : 0; \
if (!err) \
(q)->cnt_ ## op++; \
err; \
})
#define call_void_qop(q, op, args...) \
({ \
log_qop(q, op); \
if ((q)->ops->op) \
(q)->ops->op(args); \
(q)->cnt_ ## op++; \
})
#define log_vb_qop(vb, op, args...) \
dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
(vb)->vb2_queue, (vb)->index, #op, \
(vb)->vb2_queue->ops->op ? "" : " (nop)")
#define call_vb_qop(vb, op, args...) \
({ \
int err; \
\
log_vb_qop(vb, op); \
err = (vb)->vb2_queue->ops->op ? \
(vb)->vb2_queue->ops->op(args) : 0; \
if (!err) \
(vb)->cnt_ ## op++; \
err; \
})
#define call_void_vb_qop(vb, op, args...) \
({ \
log_vb_qop(vb, op); \
if ((vb)->vb2_queue->ops->op) \
(vb)->vb2_queue->ops->op(args); \
(vb)->cnt_ ## op++; \
})
#else
#define call_memop(vb, op, args...) \
((vb)->vb2_queue->mem_ops->op ? \
(vb)->vb2_queue->mem_ops->op(args) : 0)
#define call_ptr_memop(vb, op, args...) \
((vb)->vb2_queue->mem_ops->op ? \
(vb)->vb2_queue->mem_ops->op(args) : NULL)
#define call_void_memop(vb, op, args...) \
do { \
if ((vb)->vb2_queue->mem_ops->op) \
(vb)->vb2_queue->mem_ops->op(args); \
} while (0)
#define call_qop(q, op, args...) \
((q)->ops->op ? (q)->ops->op(args) : 0)
#define call_void_qop(q, op, args...) \
do { \
if ((q)->ops->op) \
(q)->ops->op(args); \
} while (0)
#define call_vb_qop(vb, op, args...) \
((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
#define call_void_vb_qop(vb, op, args...) \
do { \
if ((vb)->vb2_queue->ops->op) \
(vb)->vb2_queue->ops->op(args); \
} while (0)
#endif
#define call_bufop(q, op, args...) \
({ \
int ret = 0; \
if (q && q->buf_ops && q->buf_ops->op) \
ret = q->buf_ops->op(args); \
ret; \
})
#define call_void_bufop(q, op, args...) \
({ \
if (q && q->buf_ops && q->buf_ops->op) \
q->buf_ops->op(args); \
})
static void __vb2_queue_cancel(struct vb2_queue *q);
static void __enqueue_in_driver(struct vb2_buffer *vb);
/**
* __vb2_buf_mem_alloc() - allocate video memory for the given buffer
*/
static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
{
struct vb2_queue *q = vb->vb2_queue;
enum dma_data_direction dma_dir =
q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
void *mem_priv;
int plane;
/*
* Allocate memory for all planes in this buffer
* NOTE: mmapped areas should be page aligned
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
size, dma_dir, q->gfp_flags);
if (IS_ERR_OR_NULL(mem_priv))
goto free;
/* Associate allocator private data with this plane */
vb->planes[plane].mem_priv = mem_priv;
}
return 0;
free:
/* Free already allocated memory if one of the allocations failed */
for (; plane > 0; --plane) {
call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
vb->planes[plane - 1].mem_priv = NULL;
}
return -ENOMEM;
}
/**
* __vb2_buf_mem_free() - free memory of the given buffer
*/
static void __vb2_buf_mem_free(struct vb2_buffer *vb)
{
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane) {
call_void_memop(vb, put, vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
}
}
/**
* __vb2_buf_userptr_put() - release userspace memory associated with
* a USERPTR buffer
*/
static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
{
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane) {
if (vb->planes[plane].mem_priv)
call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
}
}
/**
* __vb2_plane_dmabuf_put() - release memory associated with
* a DMABUF shared plane
*/
static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
{
if (!p->mem_priv)
return;
if (p->dbuf_mapped)
call_void_memop(vb, unmap_dmabuf, p->mem_priv);
call_void_memop(vb, detach_dmabuf, p->mem_priv);
dma_buf_put(p->dbuf);
p->mem_priv = NULL;
p->dbuf = NULL;
p->dbuf_mapped = 0;
}
/**
* __vb2_buf_dmabuf_put() - release memory associated with
* a DMABUF shared buffer
*/
static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
{
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane)
__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
}
/**
* __setup_offsets() - setup unique offsets ("cookies") for every plane in
* the buffer.
*/
static void __setup_offsets(struct vb2_buffer *vb)
{
struct vb2_queue *q = vb->vb2_queue;
unsigned int plane;
unsigned long off = 0;
if (vb->index) {
struct vb2_buffer *prev = q->bufs[vb->index - 1];
struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
off = PAGE_ALIGN(p->m.offset + p->length);
}
for (plane = 0; plane < vb->num_planes; ++plane) {
vb->planes[plane].m.offset = off;
dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
vb->index, plane, off);
off += vb->planes[plane].length;
off = PAGE_ALIGN(off);
}
}
/**
* __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
* video buffer memory for all buffers/planes on the queue and initializes the
* queue
*
* Returns the number of buffers successfully allocated.
*/
static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
unsigned int num_buffers, unsigned int num_planes,
const unsigned plane_sizes[VB2_MAX_PLANES])
{
unsigned int buffer, plane;
struct vb2_buffer *vb;
int ret;
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate videobuf buffer structures */
vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
if (!vb) {
dprintk(1, "memory alloc for buffer struct failed\n");
break;
}
vb->state = VB2_BUF_STATE_DEQUEUED;
vb->vb2_queue = q;
vb->num_planes = num_planes;
vb->index = q->num_buffers + buffer;
vb->type = q->type;
vb->memory = memory;
for (plane = 0; plane < num_planes; ++plane) {
vb->planes[plane].length = plane_sizes[plane];
vb->planes[plane].min_length = plane_sizes[plane];
}
q->bufs[vb->index] = vb;
/* Allocate video buffer memory for the MMAP type */
if (memory == VB2_MEMORY_MMAP) {
ret = __vb2_buf_mem_alloc(vb);
if (ret) {
dprintk(1, "failed allocating memory for "
"buffer %d\n", buffer);
q->bufs[vb->index] = NULL;
kfree(vb);
break;
}
__setup_offsets(vb);
/*
* Call the driver-provided buffer initialization
* callback, if given. An error in initialization
* results in queue setup failure.
*/
ret = call_vb_qop(vb, buf_init, vb);
if (ret) {
dprintk(1, "buffer %d %p initialization"
" failed\n", buffer, vb);
__vb2_buf_mem_free(vb);
q->bufs[vb->index] = NULL;
kfree(vb);
break;
}
}
}
dprintk(1, "allocated %d buffers, %d plane(s) each\n",
buffer, num_planes);
return buffer;
}
/**
* __vb2_free_mem() - release all video buffer memory for a given queue
*/
static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
{
unsigned int buffer;
struct vb2_buffer *vb;
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
vb = q->bufs[buffer];
if (!vb)
continue;
/* Free MMAP buffers or release USERPTR buffers */
if (q->memory == VB2_MEMORY_MMAP)
__vb2_buf_mem_free(vb);
else if (q->memory == VB2_MEMORY_DMABUF)
__vb2_buf_dmabuf_put(vb);
else
__vb2_buf_userptr_put(vb);
}
}
/**
* __vb2_queue_free() - free buffers at the end of the queue - video memory and
* related information, if no buffers are left return the queue to an
* uninitialized state. Might be called even if the queue has already been freed.
*/
static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
{
unsigned int buffer;
/*
* Sanity check: when preparing a buffer the queue lock is released for
* a short while (see __buf_prepare for the details), which would allow
* a race with a reqbufs which can call this function. Removing the
* buffers from underneath __buf_prepare is obviously a bad idea, so we
* check if any of the buffers is in the state PREPARING, and if so we
* just return -EAGAIN.
*/
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
if (q->bufs[buffer] == NULL)
continue;
if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
dprintk(1, "preparing buffers, cannot free\n");
return -EAGAIN;
}
}
/* Call driver-provided cleanup function for each buffer, if provided */
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
struct vb2_buffer *vb = q->bufs[buffer];
if (vb && vb->planes[0].mem_priv)
call_void_vb_qop(vb, buf_cleanup, vb);
}
/* Release video buffer memory */
__vb2_free_mem(q, buffers);
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
* Check that all the calls were balances during the life-time of this
* queue. If not (or if the debug level is 1 or up), then dump the
* counters to the kernel log.
*/
if (q->num_buffers) {
bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
q->cnt_wait_prepare != q->cnt_wait_finish;
if (unbalanced || debug) {
pr_info("vb2: counters for queue %p:%s\n", q,
unbalanced ? " UNBALANCED!" : "");
pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
q->cnt_queue_setup, q->cnt_start_streaming,
q->cnt_stop_streaming);
pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
q->cnt_wait_prepare, q->cnt_wait_finish);
}
q->cnt_queue_setup = 0;
q->cnt_wait_prepare = 0;
q->cnt_wait_finish = 0;
q->cnt_start_streaming = 0;
q->cnt_stop_streaming = 0;
}
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
struct vb2_buffer *vb = q->bufs[buffer];
bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
vb->cnt_mem_prepare != vb->cnt_mem_finish ||
vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
vb->cnt_buf_queue != vb->cnt_buf_done ||
vb->cnt_buf_prepare != vb->cnt_buf_finish ||
vb->cnt_buf_init != vb->cnt_buf_cleanup;
if (unbalanced || debug) {
pr_info("vb2: counters for queue %p, buffer %d:%s\n",
q, buffer, unbalanced ? " UNBALANCED!" : "");
pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
vb->cnt_buf_init, vb->cnt_buf_cleanup,
vb->cnt_buf_prepare, vb->cnt_buf_finish);
pr_info("vb2: buf_queue: %u buf_done: %u\n",
vb->cnt_buf_queue, vb->cnt_buf_done);
pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
vb->cnt_mem_alloc, vb->cnt_mem_put,
vb->cnt_mem_prepare, vb->cnt_mem_finish,
vb->cnt_mem_mmap);
pr_info("vb2: get_userptr: %u put_userptr: %u\n",
vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
vb->cnt_mem_get_dmabuf,
vb->cnt_mem_num_users,
vb->cnt_mem_vaddr,
vb->cnt_mem_cookie);
}
}
#endif
/* Free videobuf buffers */
for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
++buffer) {
kfree(q->bufs[buffer]);
q->bufs[buffer] = NULL;
}
q->num_buffers -= buffers;
if (!q->num_buffers) {
q->memory = 0;
INIT_LIST_HEAD(&q->queued_list);
}
return 0;
}
/**
* vb2_buffer_in_use() - return true if the buffer is in use and
* the queue cannot be freed (by the means of REQBUFS(0)) call
*/
bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
{
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane) {
void *mem_priv = vb->planes[plane].mem_priv;
/*
* If num_users() has not been provided, call_memop
* will return 0, apparently nobody cares about this
* case anyway. If num_users() returns more than 1,
* we are not the only user of the plane's memory.
*/
if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
return true;
}
return false;
}
EXPORT_SYMBOL(vb2_buffer_in_use);
/**
* __buffers_in_use() - return true if any buffers on the queue are in use and
* the queue cannot be freed (by the means of REQBUFS(0)) call
*/
static bool __buffers_in_use(struct vb2_queue *q)
{
unsigned int buffer;
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
if (vb2_buffer_in_use(q, q->bufs[buffer]))
return true;
}
return false;
}
/**
* vb2_core_querybuf() - query video buffer information
* @q: videobuf queue
* @index: id number of the buffer
* @pb: buffer struct passed from userspace
*
* Should be called from vidioc_querybuf ioctl handler in driver.
* The passed buffer should have been verified.
* This function fills the relevant information for the userspace.
*/
void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
{
call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
}
EXPORT_SYMBOL_GPL(vb2_core_querybuf);
/**
* __verify_userptr_ops() - verify that all memory operations required for
* USERPTR queue type have been provided
*/
static int __verify_userptr_ops(struct vb2_queue *q)
{
if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
!q->mem_ops->put_userptr)
return -EINVAL;
return 0;
}
/**
* __verify_mmap_ops() - verify that all memory operations required for
* MMAP queue type have been provided
*/
static int __verify_mmap_ops(struct vb2_queue *q)
{
if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
!q->mem_ops->put || !q->mem_ops->mmap)
return -EINVAL;
return 0;
}
/**
* __verify_dmabuf_ops() - verify that all memory operations required for
* DMABUF queue type have been provided
*/
static int __verify_dmabuf_ops(struct vb2_queue *q)
{
if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
!q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
!q->mem_ops->unmap_dmabuf)
return -EINVAL;
return 0;
}
/**
* vb2_verify_memory_type() - Check whether the memory type and buffer type
* passed to a buffer operation are compatible with the queue.
*/
int vb2_verify_memory_type(struct vb2_queue *q,
enum vb2_memory memory, unsigned int type)
{
if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
memory != VB2_MEMORY_DMABUF) {
dprintk(1, "unsupported memory type\n");
return -EINVAL;
}
if (type != q->type) {
dprintk(1, "requested type is incorrect\n");
return -EINVAL;
}
/*
* Make sure all the required memory ops for given memory type
* are available.
*/
if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
dprintk(1, "MMAP for current setup unsupported\n");
return -EINVAL;
}
if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
dprintk(1, "USERPTR for current setup unsupported\n");
return -EINVAL;
}
if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
dprintk(1, "DMABUF for current setup unsupported\n");
return -EINVAL;
}
/*
* Place the busy tests at the end: -EBUSY can be ignored when
* create_bufs is called with count == 0, but count == 0 should still
* do the memory and type validation.
*/
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return 0;
}
EXPORT_SYMBOL(vb2_verify_memory_type);
/**
* vb2_core_reqbufs() - Initiate streaming
* @q: videobuf2 queue
* @memory: memory type
* @count: requested buffer count
*
* Should be called from vidioc_reqbufs ioctl handler of a driver.
* This function:
* 1) verifies streaming parameters passed from the userspace,
* 2) sets up the queue,
* 3) negotiates number of buffers and planes per buffer with the driver
* to be used during streaming,
* 4) allocates internal buffer structures (struct vb2_buffer), according to
* the agreed parameters,
* 5) for MMAP memory type, allocates actual video memory, using the
* memory handling/allocation routines provided during queue initialization
*
* If req->count is 0, all the memory will be freed instead.
* If the queue has been allocated previously (by a previous vb2_reqbufs) call
* and the queue is not busy, memory will be reallocated.
*
* The return values from this function are intended to be directly returned
* from vidioc_reqbufs handler in driver.
*/
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int *count)
{
unsigned int num_buffers, allocated_buffers, num_planes = 0;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
int ret;
if (q->streaming) {
dprintk(1, "streaming active\n");
return -EBUSY;
}
if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
/*
* We already have buffers allocated, so first check if they
* are not in use and can be freed.
*/
mutex_lock(&q->mmap_lock);
if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
mutex_unlock(&q->mmap_lock);
dprintk(1, "memory in use, cannot free\n");
return -EBUSY;
}
/*
* Call queue_cancel to clean up any buffers in the PREPARED or
* QUEUED state which is possible if buffers were prepared or
* queued without ever calling STREAMON.
*/
__vb2_queue_cancel(q);
ret = __vb2_queue_free(q, q->num_buffers);
mutex_unlock(&q->mmap_lock);
if (ret)
return ret;
/*
* In case of REQBUFS(0) return immediately without calling
* driver's queue_setup() callback and allocating resources.
*/
if (*count == 0)
return 0;
}
/*
* Make sure the requested values and current defaults are sane.
*/
num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
q->memory = memory;
/*
* Ask the driver how many buffers and planes per buffer it requires.
* Driver also sets the size and allocator context for each plane.
*/
ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
plane_sizes, q->alloc_ctx);
if (ret)
return ret;
/* Finally, allocate buffers and video memory */
allocated_buffers =
__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
if (allocated_buffers == 0) {
dprintk(1, "memory allocation failed\n");
return -ENOMEM;
}
/*
* There is no point in continuing if we can't allocate the minimum
* number of buffers needed by this vb2_queue.
*/
if (allocated_buffers < q->min_buffers_needed)
ret = -ENOMEM;
/*
* Check if driver can handle the allocated number of buffers.
*/
if (!ret && allocated_buffers < num_buffers) {
num_buffers = allocated_buffers;
/*
* num_planes is set by the previous queue_setup(), but since it
* signals to queue_setup() whether it is called from create_bufs()
* vs reqbufs() we zero it here to signal that queue_setup() is
* called for the reqbufs() case.
*/
num_planes = 0;
ret = call_qop(q, queue_setup, q, &num_buffers,
&num_planes, plane_sizes, q->alloc_ctx);
if (!ret && allocated_buffers < num_buffers)
ret = -ENOMEM;
/*
* Either the driver has accepted a smaller number of buffers,
* or .queue_setup() returned an error
*/
}
mutex_lock(&q->mmap_lock);
q->num_buffers = allocated_buffers;
if (ret < 0) {
/*
* Note: __vb2_queue_free() will subtract 'allocated_buffers'
* from q->num_buffers.
*/
__vb2_queue_free(q, allocated_buffers);
mutex_unlock(&q->mmap_lock);
return ret;
}
mutex_unlock(&q->mmap_lock);
/*
* Return the number of successfully allocated buffers
* to the userspace.
*/
*count = allocated_buffers;
q->waiting_for_buffers = !q->is_output;
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
/**
* vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
* @q: videobuf2 queue
* @memory: memory type
* @count: requested buffer count
* @parg: parameter passed to device driver
*
* Should be called from vidioc_create_bufs ioctl handler of a driver.
* This function:
* 1) verifies parameter sanity
* 2) calls the .queue_setup() queue operation
* 3) performs any necessary memory allocations
*
* The return values from this function are intended to be directly returned
* from vidioc_create_bufs handler in driver.
*/
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int *count, unsigned requested_planes,
const unsigned requested_sizes[])
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
int ret;
if (q->num_buffers == VB2_MAX_FRAME) {
dprintk(1, "maximum number of buffers already allocated\n");
return -ENOBUFS;
}
if (!q->num_buffers) {
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
q->memory = memory;
q->waiting_for_buffers = !q->is_output;
}
num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
if (requested_planes && requested_sizes) {
num_planes = requested_planes;
memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
}
/*
* Ask the driver, whether the requested number of buffers, planes per
* buffer and their sizes are acceptable
*/
ret = call_qop(q, queue_setup, q, &num_buffers,
&num_planes, plane_sizes, q->alloc_ctx);
if (ret)
return ret;
/* Finally, allocate buffers and video memory */
allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
num_planes, plane_sizes);
if (allocated_buffers == 0) {
dprintk(1, "memory allocation failed\n");
return -ENOMEM;
}
/*
* Check if driver can handle the so far allocated number of buffers.
*/
if (allocated_buffers < num_buffers) {
num_buffers = allocated_buffers;
/*
* q->num_buffers contains the total number of buffers, that the
* queue driver has set up
*/
ret = call_qop(q, queue_setup, q, &num_buffers,
&num_planes, plane_sizes, q->alloc_ctx);
if (!ret && allocated_buffers < num_buffers)
ret = -ENOMEM;
/*
* Either the driver has accepted a smaller number of buffers,
* or .queue_setup() returned an error
*/
}
mutex_lock(&q->mmap_lock);
q->num_buffers += allocated_buffers;
if (ret < 0) {
/*
* Note: __vb2_queue_free() will subtract 'allocated_buffers'
* from q->num_buffers.
*/
__vb2_queue_free(q, allocated_buffers);
mutex_unlock(&q->mmap_lock);
return -ENOMEM;
}
mutex_unlock(&q->mmap_lock);
/*
* Return the number of successfully allocated buffers
* to the userspace.
*/
*count = allocated_buffers;
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
/**
* vb2_plane_vaddr() - Return a kernel virtual address of a given plane
* @vb: vb2_buffer to which the plane in question belongs to
* @plane_no: plane number for which the address is to be returned
*
* This function returns a kernel virtual address of a given plane if
* such a mapping exist, NULL otherwise.
*/
void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
{
if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
return NULL;
return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
}
EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
/**
* vb2_plane_cookie() - Return allocator specific cookie for the given plane
* @vb: vb2_buffer to which the plane in question belongs to
* @plane_no: plane number for which the cookie is to be returned
*
* This function returns an allocator specific cookie for a given plane if
* available, NULL otherwise. The allocator should provide some simple static
* inline function, which would convert this cookie to the allocator specific
* type that can be used directly by the driver to access the buffer. This can
* be for example physical address, pointer to scatter list or IOMMU mapping.
*/
void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
{
if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
return NULL;
return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
}
EXPORT_SYMBOL_GPL(vb2_plane_cookie);
/**
* vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
* @vb: vb2_buffer returned from the driver
* @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
* VB2_BUF_STATE_ERROR if the operation finished with an error or
* VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
* If start_streaming fails then it should return buffers with state
* VB2_BUF_STATE_QUEUED to put them back into the queue.
*
* This function should be called by the driver after a hardware operation on
* a buffer is finished and the buffer may be returned to userspace. The driver
* cannot use this buffer anymore until it is queued back to it by videobuf
* by the means of buf_queue callback. Only buffers previously queued to the
* driver by buf_queue can be passed to this function.
*
* While streaming a buffer can only be returned in state DONE or ERROR.
* The start_streaming op can also return them in case the DMA engine cannot
* be started for some reason. In that case the buffers should be returned with
* state QUEUED.
*/
void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
{
struct vb2_queue *q = vb->vb2_queue;
unsigned long flags;
unsigned int plane;
if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
return;
if (WARN_ON(state != VB2_BUF_STATE_DONE &&
state != VB2_BUF_STATE_ERROR &&
state != VB2_BUF_STATE_QUEUED &&
state != VB2_BUF_STATE_REQUEUEING))
state = VB2_BUF_STATE_ERROR;
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
* Although this is not a callback, it still does have to balance
* with the buf_queue op. So update this counter manually.
*/
vb->cnt_buf_done++;
#endif
dprintk(4, "done processing on buffer %d, state: %d\n",
vb->index, state);
/* sync buffers */
for (plane = 0; plane < vb->num_planes; ++plane)
call_void_memop(vb, finish, vb->planes[plane].mem_priv);
spin_lock_irqsave(&q->done_lock, flags);
if (state == VB2_BUF_STATE_QUEUED ||
state == VB2_BUF_STATE_REQUEUEING) {
vb->state = VB2_BUF_STATE_QUEUED;
} else {
/* Add the buffer to the done buffers list */
list_add_tail(&vb->done_entry, &q->done_list);
vb->state = state;
}
atomic_dec(&q->owned_by_drv_count);
spin_unlock_irqrestore(&q->done_lock, flags);
trace_vb2_buf_done(q, vb);
switch (state) {
case VB2_BUF_STATE_QUEUED:
return;
case VB2_BUF_STATE_REQUEUEING:
if (q->start_streaming_called)
__enqueue_in_driver(vb);
return;
default:
/* Inform any processes that may be waiting for buffers */
wake_up(&q->done_wq);
break;
}
}
EXPORT_SYMBOL_GPL(vb2_buffer_done);
/**
* vb2_discard_done() - discard all buffers marked as DONE
* @q: videobuf2 queue
*
* This function is intended to be used with suspend/resume operations. It
* discards all 'done' buffers as they would be too old to be requested after
* resume.
*
* Drivers must stop the hardware and synchronize with interrupt handlers and/or
* delayed works before calling this function to make sure no buffer will be
* touched by the driver and/or hardware.
*/
void vb2_discard_done(struct vb2_queue *q)
{
struct vb2_buffer *vb;
unsigned long flags;
spin_lock_irqsave(&q->done_lock, flags);
list_for_each_entry(vb, &q->done_list, done_entry)
vb->state = VB2_BUF_STATE_ERROR;
spin_unlock_irqrestore(&q->done_lock, flags);
}
EXPORT_SYMBOL_GPL(vb2_discard_done);
/**
* __qbuf_mmap() - handle qbuf of an MMAP buffer
*/
static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
{
int ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
vb, pb, vb->planes);
return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
}
/**
* __qbuf_userptr() - handle qbuf of a USERPTR buffer
*/
static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
{
struct vb2_plane planes[VB2_MAX_PLANES];
struct vb2_queue *q = vb->vb2_queue;
void *mem_priv;
unsigned int plane;
int ret;
enum dma_data_direction dma_dir =
q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
bool reacquired = vb->planes[0].mem_priv == NULL;
memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
/* Copy relevant information provided by the userspace */
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes);
if (ret)
return ret;
for (plane = 0; plane < vb->num_planes; ++plane) {
/* Skip the plane if already verified */
if (vb->planes[plane].m.userptr &&
vb->planes[plane].m.userptr == planes[plane].m.userptr
&& vb->planes[plane].length == planes[plane].length)
continue;
dprintk(3, "userspace address for plane %d changed, "
"reacquiring memory\n", plane);
/* Check if the provided plane buffer is large enough */
if (planes[plane].length < vb->planes[plane].min_length) {
dprintk(1, "provided buffer size %u is less than "
"setup size %u for plane %d\n",
planes[plane].length,
vb->planes[plane].min_length,
plane);
ret = -EINVAL;
goto err;
}
/* Release previously acquired memory if present */
if (vb->planes[plane].mem_priv) {
if (!reacquired) {
reacquired = true;
call_void_vb_qop(vb, buf_cleanup, vb);
}
call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
}
vb->planes[plane].mem_priv = NULL;
vb->planes[plane].bytesused = 0;
vb->planes[plane].length = 0;
vb->planes[plane].m.userptr = 0;
vb->planes[plane].data_offset = 0;
/* Acquire each plane's memory */
mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
planes[plane].m.userptr,
planes[plane].length, dma_dir);
if (IS_ERR_OR_NULL(mem_priv)) {
dprintk(1, "failed acquiring userspace "
"memory for plane %d\n", plane);
ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
goto err;
}
vb->planes[plane].mem_priv = mem_priv;
}
/*
* Now that everything is in order, copy relevant information
* provided by userspace.
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
vb->planes[plane].bytesused = planes[plane].bytesused;
vb->planes[plane].length = planes[plane].length;
vb->planes[plane].m.userptr = planes[plane].m.userptr;
vb->planes[plane].data_offset = planes[plane].data_offset;
}
if (reacquired) {
/*
* One or more planes changed, so we must call buf_init to do
* the driver-specific initialization on the newly acquired
* buffer, if provided.
*/
ret = call_vb_qop(vb, buf_init, vb);
if (ret) {
dprintk(1, "buffer initialization failed\n");
goto err;
}
}
ret = call_vb_qop(vb, buf_prepare, vb);
if (ret) {
dprintk(1, "buffer preparation failed\n");
call_void_vb_qop(vb, buf_cleanup, vb);
goto err;
}
return 0;
err:
/* In case of errors, release planes that were already acquired */
for (plane = 0; plane < vb->num_planes; ++plane) {
if (vb->planes[plane].mem_priv)
call_void_memop(vb, put_userptr,
vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
vb->planes[plane].m.userptr = 0;
vb->planes[plane].length = 0;
}
return ret;
}
/**
* __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
*/
static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
{
struct vb2_plane planes[VB2_MAX_PLANES];
struct vb2_queue *q = vb->vb2_queue;
void *mem_priv;
unsigned int plane;
int ret;
enum dma_data_direction dma_dir =
q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
bool reacquired = vb->planes[0].mem_priv == NULL;
memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
/* Copy relevant information provided by the userspace */
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes);
if (ret)
return ret;
for (plane = 0; plane < vb->num_planes; ++plane) {
struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
if (IS_ERR_OR_NULL(dbuf)) {
dprintk(1, "invalid dmabuf fd for plane %d\n",
plane);
ret = -EINVAL;
goto err;
}
/* use DMABUF size if length is not provided */
if (planes[plane].length == 0)
planes[plane].length = dbuf->size;
if (planes[plane].length < vb->planes[plane].min_length) {
dprintk(1, "invalid dmabuf length for plane %d\n",
plane);
ret = -EINVAL;
goto err;
}
/* Skip the plane if already verified */
if (dbuf == vb->planes[plane].dbuf &&
vb->planes[plane].length == planes[plane].length) {
dma_buf_put(dbuf);
continue;
}
dprintk(1, "buffer for plane %d changed\n", plane);
if (!reacquired) {
reacquired = true;
call_void_vb_qop(vb, buf_cleanup, vb);
}
/* Release previously acquired memory if present */
__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
vb->planes[plane].bytesused = 0;
vb->planes[plane].length = 0;
vb->planes[plane].m.fd = 0;
vb->planes[plane].data_offset = 0;
/* Acquire each plane's memory */
mem_priv = call_ptr_memop(vb, attach_dmabuf,
q->alloc_ctx[plane], dbuf, planes[plane].length,
dma_dir);
if (IS_ERR(mem_priv)) {
dprintk(1, "failed to attach dmabuf\n");
ret = PTR_ERR(mem_priv);
dma_buf_put(dbuf);
goto err;
}
vb->planes[plane].dbuf = dbuf;
vb->planes[plane].mem_priv = mem_priv;
}
/* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
* really we want to do this just before the DMA, not while queueing
* the buffer(s)..
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
if (ret) {
dprintk(1, "failed to map dmabuf for plane %d\n",
plane);
goto err;
}
vb->planes[plane].dbuf_mapped = 1;
}
/*
* Now that everything is in order, copy relevant information
* provided by userspace.
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
vb->planes[plane].bytesused = planes[plane].bytesused;
vb->planes[plane].length = planes[plane].length;
vb->planes[plane].m.fd = planes[plane].m.fd;
vb->planes[plane].data_offset = planes[plane].data_offset;
}
if (reacquired) {
/*
* Call driver-specific initialization on the newly acquired buffer,
* if provided.
*/
ret = call_vb_qop(vb, buf_init, vb);
if (ret) {
dprintk(1, "buffer initialization failed\n");
goto err;
}
}
ret = call_vb_qop(vb, buf_prepare, vb);
if (ret) {
dprintk(1, "buffer preparation failed\n");
call_void_vb_qop(vb, buf_cleanup, vb);
goto err;
}
return 0;
err:
/* In case of errors, release planes that were already acquired */
__vb2_buf_dmabuf_put(vb);
return ret;
}
/**
* __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
*/
static void __enqueue_in_driver(struct vb2_buffer *vb)
{
struct vb2_queue *q = vb->vb2_queue;
unsigned int plane;
vb->state = VB2_BUF_STATE_ACTIVE;
atomic_inc(&q->owned_by_drv_count);
trace_vb2_buf_queue(q, vb);
/* sync buffers */
for (plane = 0; plane < vb->num_planes; ++plane)
call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
call_void_vb_qop(vb, buf_queue, vb);
}
static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
{
struct vb2_queue *q = vb->vb2_queue;
int ret;
if (q->error) {
dprintk(1, "fatal error occurred on queue\n");
return -EIO;
}
vb->state = VB2_BUF_STATE_PREPARING;
switch (q->memory) {
case VB2_MEMORY_MMAP:
ret = __qbuf_mmap(vb, pb);
break;
case VB2_MEMORY_USERPTR:
ret = __qbuf_userptr(vb, pb);
break;
case VB2_MEMORY_DMABUF:
ret = __qbuf_dmabuf(vb, pb);
break;
default:
WARN(1, "Invalid queue type\n");
ret = -EINVAL;
}
if (ret)
dprintk(1, "buffer preparation failed: %d\n", ret);
vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
return ret;
}
/**
* vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
* to the kernel
* @q: videobuf2 queue
* @index: id number of the buffer
* @pb: buffer structure passed from userspace to vidioc_prepare_buf
* handler in driver
*
* Should be called from vidioc_prepare_buf ioctl handler of a driver.
* The passed buffer should have been verified.
* This function calls buf_prepare callback in the driver (if provided),
* in which driver-specific buffer initialization can be performed,
*
* The return values from this function are intended to be directly returned
* from vidioc_prepare_buf handler in driver.
*/
int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
{
struct vb2_buffer *vb;
int ret;
vb = q->bufs[index];
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
dprintk(1, "invalid buffer state %d\n",
vb->state);
return -EINVAL;
}
ret = __buf_prepare(vb, pb);
if (ret)
return ret;
/* Fill buffer information for the userspace */
call_void_bufop(q, fill_user_buffer, vb, pb);
dprintk(1, "prepare of buffer %d succeeded\n", vb->index);
return ret;
}
EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
/**
* vb2_start_streaming() - Attempt to start streaming.
* @q: videobuf2 queue
*
* Attempt to start streaming. When this function is called there must be
* at least q->min_buffers_needed buffers queued up (i.e. the minimum
* number of buffers required for the DMA engine to function). If the
* @start_streaming op fails it is supposed to return all the driver-owned
* buffers back to vb2 in state QUEUED. Check if that happened and if
* not warn and reclaim them forcefully.
*/
static int vb2_start_streaming(struct vb2_queue *q)
{
struct vb2_buffer *vb;
int ret;
/*
* If any buffers were queued before streamon,
* we can now pass them to driver for processing.
*/
list_for_each_entry(vb, &q->queued_list, queued_entry)
__enqueue_in_driver(vb);
/* Tell the driver to start streaming */
q->start_streaming_called = 1;
ret = call_qop(q, start_streaming, q,
atomic_read(&q->owned_by_drv_count));
if (!ret)
return 0;
q->start_streaming_called = 0;
dprintk(1, "driver refused to start streaming\n");
/*
* If you see this warning, then the driver isn't cleaning up properly
* after a failed start_streaming(). See the start_streaming()
* documentation in videobuf2-core.h for more information how buffers
* should be returned to vb2 in start_streaming().
*/
if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
unsigned i;
/*
* Forcefully reclaim buffers if the driver did not
* correctly return them to vb2.
*/
for (i = 0; i < q->num_buffers; ++i) {
vb = q->bufs[i];
if (vb->state == VB2_BUF_STATE_ACTIVE)
vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
}
/* Must be zero now */
WARN_ON(atomic_read(&q->owned_by_drv_count));
}
/*
* If done_list is not empty, then start_streaming() didn't call
* vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
* STATE_DONE.
*/
WARN_ON(!list_empty(&q->done_list));
return ret;
}
/**
* vb2_core_qbuf() - Queue a buffer from userspace
* @q: videobuf2 queue
* @index: id number of the buffer
* @pb: buffer structure passed from userspace to vidioc_qbuf handler
* in driver
*
* Should be called from vidioc_qbuf ioctl handler of a driver.
* The passed buffer should have been verified.
* This function:
* 1) if necessary, calls buf_prepare callback in the driver (if provided), in
* which driver-specific buffer initialization can be performed,
* 2) if streaming is on, queues the buffer in driver by the means of buf_queue
* callback for processing.
*
* The return values from this function are intended to be directly returned
* from vidioc_qbuf handler in driver.
*/
int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
{
struct vb2_buffer *vb;
int ret;
vb = q->bufs[index];
switch (vb->state) {
case VB2_BUF_STATE_DEQUEUED:
ret = __buf_prepare(vb, pb);
if (ret)
return ret;
break;
case VB2_BUF_STATE_PREPARED:
break;
case VB2_BUF_STATE_PREPARING:
dprintk(1, "buffer still being prepared\n");
return -EINVAL;
default:
dprintk(1, "invalid buffer state %d\n", vb->state);
return -EINVAL;
}
/*
* Add to the queued buffers list, a buffer will stay on it until
* dequeued in dqbuf.
*/
list_add_tail(&vb->queued_entry, &q->queued_list);
q->queued_count++;
q->waiting_for_buffers = false;
vb->state = VB2_BUF_STATE_QUEUED;
call_void_bufop(q, copy_timestamp, vb, pb);
trace_vb2_qbuf(q, vb);
/*
* If already streaming, give the buffer to driver for processing.
* If not, the buffer will be given to driver on next streamon.
*/
if (q->start_streaming_called)
__enqueue_in_driver(vb);
/* Fill buffer information for the userspace */
call_void_bufop(q, fill_user_buffer, vb, pb);
/*
* If streamon has been called, and we haven't yet called
* start_streaming() since not enough buffers were queued, and
* we now have reached the minimum number of queued buffers,
* then we can finally call start_streaming().
*/
if (q->streaming && !q->start_streaming_called &&
q->queued_count >= q->min_buffers_needed) {
ret = vb2_start_streaming(q);
if (ret)
return ret;
}
dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_qbuf);
/**
* __vb2_wait_for_done_vb() - wait for a buffer to become available
* for dequeuing
*
* Will sleep if required for nonblocking == false.
*/
static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
{
/*
* All operations on vb_done_list are performed under done_lock
* spinlock protection. However, buffers may be removed from
* it and returned to userspace only while holding both driver's
* lock and the done_lock spinlock. Thus we can be sure that as
* long as we hold the driver's lock, the list will remain not
* empty if list_empty() check succeeds.
*/
for (;;) {
int ret;
if (!q->streaming) {
dprintk(1, "streaming off, will not wait for buffers\n");
return -EINVAL;
}
if (q->error) {
dprintk(1, "Queue in error state, will not wait for buffers\n");
return -EIO;
}
if (q->last_buffer_dequeued) {
dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
return -EPIPE;
}
if (!list_empty(&q->done_list)) {
/*
* Found a buffer that we were waiting for.
*/
break;
}
if (nonblocking) {
dprintk(1, "nonblocking and no buffers to dequeue, "
"will not wait\n");
return -EAGAIN;
}
/*
* We are streaming and blocking, wait for another buffer to
* become ready or for streamoff. Driver's lock is released to
* allow streamoff or qbuf to be called while waiting.
*/
call_void_qop(q, wait_prepare, q);
/*
* All locks have been released, it is safe to sleep now.
*/
dprintk(3, "will sleep waiting for buffers\n");
ret = wait_event_interruptible(q->done_wq,
!list_empty(&q->done_list) || !q->streaming ||
q->error);
/*
* We need to reevaluate both conditions again after reacquiring
* the locks or return an error if one occurred.
*/
call_void_qop(q, wait_finish, q);
if (ret) {
dprintk(1, "sleep was interrupted\n");
return ret;
}
}
return 0;
}
/**
* __vb2_get_done_vb() - get a buffer ready for dequeuing
*
* Will sleep if required for nonblocking == false.
*/
static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
int nonblocking)
{
unsigned long flags;
int ret;
/*
* Wait for at least one buffer to become available on the done_list.
*/
ret = __vb2_wait_for_done_vb(q, nonblocking);
if (ret)
return ret;
/*
* Driver's lock has been held since we last verified that done_list
* is not empty, so no need for another list_empty(done_list) check.
*/
spin_lock_irqsave(&q->done_lock, flags);
*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
/*
* Only remove the buffer from done_list if v4l2_buffer can handle all
* the planes.
* Verifying planes is NOT necessary since it already has been checked
* before the buffer is queued/prepared. So it can never fail.
*/
list_del(&(*vb)->done_entry);
spin_unlock_irqrestore(&q->done_lock, flags);
return ret;
}
/**
* vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
* @q: videobuf2 queue
*
* This function will wait until all buffers that have been given to the driver
* by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
* wait_prepare, wait_finish pair. It is intended to be called with all locks
* taken, for example from stop_streaming() callback.
*/
int vb2_wait_for_all_buffers(struct vb2_queue *q)
{
if (!q->streaming) {
dprintk(1, "streaming off, will not wait for buffers\n");
return -EINVAL;
}
if (q->start_streaming_called)
wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
return 0;
}
EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
/**
* __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
*/
static void __vb2_dqbuf(struct vb2_buffer *vb)
{
struct vb2_queue *q = vb->vb2_queue;
unsigned int i;
/* nothing to do if the buffer is already dequeued */
if (vb->state == VB2_BUF_STATE_DEQUEUED)
return;
vb->state = VB2_BUF_STATE_DEQUEUED;
/* unmap DMABUF buffer */
if (q->memory == VB2_MEMORY_DMABUF)
for (i = 0; i < vb->num_planes; ++i) {
if (!vb->planes[i].dbuf_mapped)
continue;
call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
vb->planes[i].dbuf_mapped = 0;
}
}
/**
* vb2_dqbuf() - Dequeue a buffer to the userspace
* @q: videobuf2 queue
* @pb: buffer structure passed from userspace to vidioc_dqbuf handler
* in driver
* @nonblocking: if true, this call will not sleep waiting for a buffer if no
* buffers ready for dequeuing are present. Normally the driver
* would be passing (file->f_flags & O_NONBLOCK) here
*
* Should be called from vidioc_dqbuf ioctl handler of a driver.
* The passed buffer should have been verified.
* This function:
* 1) calls buf_finish callback in the driver (if provided), in which
* driver can perform any additional operations that may be required before
* returning the buffer to userspace, such as cache sync,
* 2) the buffer struct members are filled with relevant information for
* the userspace.
*
* The return values from this function are intended to be directly returned
* from vidioc_dqbuf handler in driver.
*/
int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking)
{
struct vb2_buffer *vb = NULL;
int ret;
ret = __vb2_get_done_vb(q, &vb, nonblocking);
if (ret < 0)
return ret;
switch (vb->state) {
case VB2_BUF_STATE_DONE:
dprintk(3, "returning done buffer\n");
break;
case VB2_BUF_STATE_ERROR:
dprintk(3, "returning done buffer with errors\n");
break;
default:
dprintk(1, "invalid buffer state\n");
return -EINVAL;
}
call_void_vb_qop(vb, buf_finish, vb);
/* Fill buffer information for the userspace */
call_void_bufop(q, fill_user_buffer, vb, pb);
/* Remove from videobuf queue */
list_del(&vb->queued_entry);
q->queued_count--;
trace_vb2_dqbuf(q, vb);
/* go back to dequeued state */
__vb2_dqbuf(vb);
dprintk(1, "dqbuf of buffer %d, with state %d\n",
vb->index, vb->state);
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
/**
* __vb2_queue_cancel() - cancel and stop (pause) streaming
*
* Removes all queued buffers from driver's queue and all buffers queued by
* userspace from videobuf's queue. Returns to state after reqbufs.
*/
static void __vb2_queue_cancel(struct vb2_queue *q)
{
unsigned int i;
/*
* Tell driver to stop all transactions and release all queued
* buffers.
*/
if (q->start_streaming_called)
call_void_qop(q, stop_streaming, q);
/*
* If you see this warning, then the driver isn't cleaning up properly
* in stop_streaming(). See the stop_streaming() documentation in
* videobuf2-core.h for more information how buffers should be returned
* to vb2 in stop_streaming().
*/
if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
for (i = 0; i < q->num_buffers; ++i)
if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
/* Must be zero now */
WARN_ON(atomic_read(&q->owned_by_drv_count));
}
q->streaming = 0;
q->start_streaming_called = 0;
q->queued_count = 0;
q->error = 0;
/*
* Remove all buffers from videobuf's list...
*/
INIT_LIST_HEAD(&q->queued_list);
/*
* ...and done list; userspace will not receive any buffers it
* has not already dequeued before initiating cancel.
*/
INIT_LIST_HEAD(&q->done_list);
atomic_set(&q->owned_by_drv_count, 0);
wake_up_all(&q->done_wq);
/*
* Reinitialize all buffers for next use.
* Make sure to call buf_finish for any queued buffers. Normally
* that's done in dqbuf, but that's not going to happen when we
* cancel the whole queue. Note: this code belongs here, not in
* __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
* call to __fill_v4l2_buffer() after buf_finish(). That order can't
* be changed, so we can't move the buf_finish() to __vb2_dqbuf().
*/
for (i = 0; i < q->num_buffers; ++i) {
struct vb2_buffer *vb = q->bufs[i];
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
vb->state = VB2_BUF_STATE_PREPARED;
call_void_vb_qop(vb, buf_finish, vb);
}
__vb2_dqbuf(vb);
}
}
int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
{
int ret;
if (type != q->type) {
dprintk(1, "invalid stream type\n");
return -EINVAL;
}
if (q->streaming) {
dprintk(3, "already streaming\n");
return 0;
}
if (!q->num_buffers) {
dprintk(1, "no buffers have been allocated\n");
return -EINVAL;
}
if (q->num_buffers < q->min_buffers_needed) {
dprintk(1, "need at least %u allocated buffers\n",
q->min_buffers_needed);
return -EINVAL;
}
/*
* Tell driver to start streaming provided sufficient buffers
* are available.
*/
if (q->queued_count >= q->min_buffers_needed) {
ret = vb2_start_streaming(q);
if (ret) {
__vb2_queue_cancel(q);
return ret;
}
}
q->streaming = 1;
dprintk(3, "successful\n");
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_streamon);
/**
* vb2_queue_error() - signal a fatal error on the queue
* @q: videobuf2 queue
*
* Flag that a fatal unrecoverable error has occurred and wake up all processes
* waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
* buffers will return -EIO.
*
* The error flag will be cleared when cancelling the queue, either from
* vb2_streamoff or vb2_queue_release. Drivers should thus not call this
* function before starting the stream, otherwise the error flag will remain set
* until the queue is released when closing the device node.
*/
void vb2_queue_error(struct vb2_queue *q)
{
q->error = 1;
wake_up_all(&q->done_wq);
}
EXPORT_SYMBOL_GPL(vb2_queue_error);
int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
{
if (type != q->type) {
dprintk(1, "invalid stream type\n");
return -EINVAL;
}
/*
* Cancel will pause streaming and remove all buffers from the driver
* and videobuf, effectively returning control over them to userspace.
*
* Note that we do this even if q->streaming == 0: if you prepare or
* queue buffers, and then call streamoff without ever having called
* streamon, you would still expect those buffers to be returned to
* their normal dequeued state.
*/
__vb2_queue_cancel(q);
q->waiting_for_buffers = !q->is_output;
q->last_buffer_dequeued = false;
dprintk(3, "successful\n");
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_streamoff);
/**
* __find_plane_by_offset() - find plane associated with the given offset off
*/
static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
unsigned int *_buffer, unsigned int *_plane)
{
struct vb2_buffer *vb;
unsigned int buffer, plane;
/*
* Go over all buffers and their planes, comparing the given offset
* with an offset assigned to each plane. If a match is found,
* return its buffer and plane numbers.
*/
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
vb = q->bufs[buffer];
for (plane = 0; plane < vb->num_planes; ++plane) {
if (vb->planes[plane].m.offset == off) {
*_buffer = buffer;
*_plane = plane;
return 0;
}
}
}
return -EINVAL;
}
/**
* vb2_core_expbuf() - Export a buffer as a file descriptor
* @q: videobuf2 queue
* @fd: file descriptor associated with DMABUF (set by driver) *
* @type: buffer type
* @index: id number of the buffer
* @plane: index of the plane to be exported, 0 for single plane queues
* @flags: flags for newly created file, currently only O_CLOEXEC is
* supported, refer to manual of open syscall for more details
*
* The return values from this function are intended to be directly returned
* from vidioc_expbuf handler in driver.
*/
int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
unsigned int index, unsigned int plane, unsigned int flags)
{
struct vb2_buffer *vb = NULL;
struct vb2_plane *vb_plane;
int ret;
struct dma_buf *dbuf;
if (q->memory != VB2_MEMORY_MMAP) {
dprintk(1, "queue is not currently set up for mmap\n");
return -EINVAL;
}
if (!q->mem_ops->get_dmabuf) {
dprintk(1, "queue does not support DMA buffer exporting\n");
return -EINVAL;
}
if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
return -EINVAL;
}
if (type != q->type) {
dprintk(1, "invalid buffer type\n");
return -EINVAL;
}
if (index >= q->num_buffers) {
dprintk(1, "buffer index out of range\n");
return -EINVAL;
}
vb = q->bufs[index];
if (plane >= vb->num_planes) {
dprintk(1, "buffer plane out of range\n");
return -EINVAL;
}
if (vb2_fileio_is_active(q)) {
dprintk(1, "expbuf: file io in progress\n");
return -EBUSY;
}
vb_plane = &vb->planes[plane];
dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
flags & O_ACCMODE);
if (IS_ERR_OR_NULL(dbuf)) {
dprintk(1, "failed to export buffer %d, plane %d\n",
index, plane);
return -EINVAL;
}
ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
if (ret < 0) {
dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
index, plane, ret);
dma_buf_put(dbuf);
return ret;
}
dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
index, plane, ret);
*fd = ret;
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_expbuf);
/**
* vb2_mmap() - map video buffers into application address space
* @q: videobuf2 queue
* @vma: vma passed to the mmap file operation handler in the driver
*
* Should be called from mmap file operation handler of a driver.
* This function maps one plane of one of the available video buffers to
* userspace. To map whole video memory allocated on reqbufs, this function
* has to be called once per each plane per each buffer previously allocated.
*
* When the userspace application calls mmap, it passes to it an offset returned
* to it earlier by the means of vidioc_querybuf handler. That offset acts as
* a "cookie", which is then used to identify the plane to be mapped.
* This function finds a plane with a matching offset and a mapping is performed
* by the means of a provided memory operation.
*
* The return values from this function are intended to be directly returned
* from the mmap handler in driver.
*/
int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
{
unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
struct vb2_buffer *vb;
unsigned int buffer = 0, plane = 0;
int ret;
unsigned long length;
if (q->memory != VB2_MEMORY_MMAP) {
dprintk(1, "queue is not currently set up for mmap\n");
return -EINVAL;
}
/*
* Check memory area access mode.
*/
if (!(vma->vm_flags & VM_SHARED)) {
dprintk(1, "invalid vma flags, VM_SHARED needed\n");
return -EINVAL;
}
if (q->is_output) {
if (!(vma->vm_flags & VM_WRITE)) {
dprintk(1, "invalid vma flags, VM_WRITE needed\n");
return -EINVAL;
}
} else {
if (!(vma->vm_flags & VM_READ)) {
dprintk(1, "invalid vma flags, VM_READ needed\n");
return -EINVAL;
}
}
if (vb2_fileio_is_active(q)) {
dprintk(1, "mmap: file io in progress\n");
return -EBUSY;
}
/*
* Find the plane corresponding to the offset passed by userspace.
*/
ret = __find_plane_by_offset(q, off, &buffer, &plane);
if (ret)
return ret;
vb = q->bufs[buffer];
/*
* MMAP requires page_aligned buffers.
* The buffer length was page_aligned at __vb2_buf_mem_alloc(),
* so, we need to do the same here.
*/
length = PAGE_ALIGN(vb->planes[plane].length);
if (length < (vma->vm_end - vma->vm_start)) {
dprintk(1,
"MMAP invalid, as it would overflow buffer length\n");
return -EINVAL;
}
mutex_lock(&q->mmap_lock);
ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
mutex_unlock(&q->mmap_lock);
if (ret)
return ret;
dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
return 0;
}
EXPORT_SYMBOL_GPL(vb2_mmap);
#ifndef CONFIG_MMU
unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags)
{
unsigned long off = pgoff << PAGE_SHIFT;
struct vb2_buffer *vb;
unsigned int buffer, plane;
void *vaddr;
int ret;
if (q->memory != VB2_MEMORY_MMAP) {
dprintk(1, "queue is not currently set up for mmap\n");
return -EINVAL;
}
/*
* Find the plane corresponding to the offset passed by userspace.
*/
ret = __find_plane_by_offset(q, off, &buffer, &plane);
if (ret)
return ret;
vb = q->bufs[buffer];
vaddr = vb2_plane_vaddr(vb, plane);
return vaddr ? (unsigned long)vaddr : -EINVAL;
}
EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
#endif
/**
* vb2_core_queue_init() - initialize a videobuf2 queue
* @q: videobuf2 queue; this structure should be allocated in driver
*
* The vb2_queue structure should be allocated by the driver. The driver is
* responsible of clearing it's content and setting initial values for some
* required entries before calling this function.
* q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
* to the struct vb2_queue description in include/media/videobuf2-core.h
* for more information.
*/
int vb2_core_queue_init(struct vb2_queue *q)
{
/*
* Sanity check
*/
if (WARN_ON(!q) ||
WARN_ON(!q->ops) ||
WARN_ON(!q->mem_ops) ||
WARN_ON(!q->type) ||
WARN_ON(!q->io_modes) ||
WARN_ON(!q->ops->queue_setup) ||
WARN_ON(!q->ops->buf_queue))
return -EINVAL;
INIT_LIST_HEAD(&q->queued_list);
INIT_LIST_HEAD(&q->done_list);
spin_lock_init(&q->done_lock);
mutex_init(&q->mmap_lock);
init_waitqueue_head(&q->done_wq);
if (q->buf_struct_size == 0)
q->buf_struct_size = sizeof(struct vb2_buffer);
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_queue_init);
static int __vb2_init_fileio(struct vb2_queue *q, int read);
static int __vb2_cleanup_fileio(struct vb2_queue *q);
/**
* vb2_core_queue_release() - stop streaming, release the queue and free memory
* @q: videobuf2 queue
*
* This function stops streaming and performs necessary clean ups, including
* freeing video buffer memory. The driver is responsible for freeing
* the vb2_queue structure itself.
*/
void vb2_core_queue_release(struct vb2_queue *q)
{
__vb2_cleanup_fileio(q);
__vb2_queue_cancel(q);
mutex_lock(&q->mmap_lock);
__vb2_queue_free(q, q->num_buffers);
mutex_unlock(&q->mmap_lock);
}
EXPORT_SYMBOL_GPL(vb2_core_queue_release);
/**
* vb2_core_poll() - implements poll userspace operation
* @q: videobuf2 queue
* @file: file argument passed to the poll file operation handler
* @wait: wait argument passed to the poll file operation handler
*
* This function implements poll file operation handler for a driver.
* For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
* be informed that the file descriptor of a video device is available for
* reading.
* For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
* will be reported as available for writing.
*
* The return values from this function are intended to be directly returned
* from poll handler in driver.
*/
unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
poll_table *wait)
{
unsigned long req_events = poll_requested_events(wait);
struct vb2_buffer *vb = NULL;
unsigned long flags;
if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
return 0;
if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
return 0;
/*
* Start file I/O emulator only if streaming API has not been used yet.
*/
if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
if (!q->is_output && (q->io_modes & VB2_READ) &&
(req_events & (POLLIN | POLLRDNORM))) {
if (__vb2_init_fileio(q, 1))
return POLLERR;
}
if (q->is_output && (q->io_modes & VB2_WRITE) &&
(req_events & (POLLOUT | POLLWRNORM))) {
if (__vb2_init_fileio(q, 0))
return POLLERR;
/*
* Write to OUTPUT queue can be done immediately.
*/
return POLLOUT | POLLWRNORM;
}
}
/*
* There is nothing to wait for if the queue isn't streaming, or if the
* error flag is set.
*/
if (!vb2_is_streaming(q) || q->error)
return POLLERR;
/*
* For output streams you can call write() as long as there are fewer
* buffers queued than there are buffers available.
*/
if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
return POLLOUT | POLLWRNORM;
if (list_empty(&q->done_list)) {
/*
* If the last buffer was dequeued from a capture queue,
* return immediately. DQBUF will return -EPIPE.
*/
if (q->last_buffer_dequeued)
return POLLIN | POLLRDNORM;
poll_wait(file, &q->done_wq, wait);
}
/*
* Take first buffer available for dequeuing.
*/
spin_lock_irqsave(&q->done_lock, flags);
if (!list_empty(&q->done_list))
vb = list_first_entry(&q->done_list, struct vb2_buffer,
done_entry);
spin_unlock_irqrestore(&q->done_lock, flags);
if (vb && (vb->state == VB2_BUF_STATE_DONE
|| vb->state == VB2_BUF_STATE_ERROR)) {
return (q->is_output) ?
POLLOUT | POLLWRNORM :
POLLIN | POLLRDNORM;
}
return 0;
}
EXPORT_SYMBOL_GPL(vb2_core_poll);
/**
* struct vb2_fileio_buf - buffer context used by file io emulator
*
* vb2 provides a compatibility layer and emulator of file io (read and
* write) calls on top of streaming API. This structure is used for
* tracking context related to the buffers.
*/
struct vb2_fileio_buf {
void *vaddr;
unsigned int size;
unsigned int pos;
unsigned int queued:1;
};
/**
* struct vb2_fileio_data - queue context used by file io emulator
*
* @cur_index: the index of the buffer currently being read from or
* written to. If equal to q->num_buffers then a new buffer
* must be dequeued.
* @initial_index: in the read() case all buffers are queued up immediately
* in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
* buffers. However, in the write() case no buffers are initially
* queued, instead whenever a buffer is full it is queued up by
* __vb2_perform_fileio(). Only once all available buffers have
* been queued up will __vb2_perform_fileio() start to dequeue
* buffers. This means that initially __vb2_perform_fileio()
* needs to know what buffer index to use when it is queuing up
* the buffers for the first time. That initial index is stored
* in this field. Once it is equal to q->num_buffers all
* available buffers have been queued and __vb2_perform_fileio()
* should start the normal dequeue/queue cycle.
*
* vb2 provides a compatibility layer and emulator of file io (read and
* write) calls on top of streaming API. For proper operation it required
* this structure to save the driver state between each call of the read
* or write function.
*/
struct vb2_fileio_data {
unsigned int count;
unsigned int type;
unsigned int memory;
struct vb2_buffer *b;
struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
unsigned int cur_index;
unsigned int initial_index;
unsigned int q_count;
unsigned int dq_count;
unsigned read_once:1;
unsigned write_immediately:1;
};
/**
* __vb2_init_fileio() - initialize file io emulator
* @q: videobuf2 queue
* @read: mode selector (1 means read, 0 means write)
*/
static int __vb2_init_fileio(struct vb2_queue *q, int read)
{
struct vb2_fileio_data *fileio;
int i, ret;
unsigned int count = 0;
/*
* Sanity check
*/
if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
(!read && !(q->io_modes & VB2_WRITE))))
return -EINVAL;
/*
* Check if device supports mapping buffers to kernel virtual space.
*/
if (!q->mem_ops->vaddr)
return -EBUSY;
/*
* Check if streaming api has not been already activated.
*/
if (q->streaming || q->num_buffers > 0)
return -EBUSY;
/*
* Start with count 1, driver can increase it in queue_setup()
*/
count = 1;
dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
(read) ? "read" : "write", count, q->fileio_read_once,
q->fileio_write_immediately);
fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
if (fileio == NULL)
return -ENOMEM;
fileio->b = kzalloc(q->buf_struct_size, GFP_KERNEL);
if (fileio->b == NULL) {
kfree(fileio);
return -ENOMEM;
}
fileio->read_once = q->fileio_read_once;
fileio->write_immediately = q->fileio_write_immediately;
/*
* Request buffers and use MMAP type to force driver
* to allocate buffers by itself.
*/
fileio->count = count;
fileio->memory = VB2_MEMORY_MMAP;
fileio->type = q->type;
q->fileio = fileio;
ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
if (ret)
goto err_kfree;
/*
* Check if plane_count is correct
* (multiplane buffers are not supported).
*/
if (q->bufs[0]->num_planes != 1) {
ret = -EBUSY;
goto err_reqbufs;
}
/*
* Get kernel address of each buffer.
*/
for (i = 0; i < q->num_buffers; i++) {
fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
if (fileio->bufs[i].vaddr == NULL) {
ret = -EINVAL;
goto err_reqbufs;
}
fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
}
/*
* Read mode requires pre queuing of all buffers.
*/
if (read) {
/*
* Queue all buffers.
*/
for (i = 0; i < q->num_buffers; i++) {
struct vb2_buffer *b = fileio->b;
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
b->index = i;
ret = vb2_core_qbuf(q, i, b);
if (ret)
goto err_reqbufs;
fileio->bufs[i].queued = 1;
}
/*
* All buffers have been queued, so mark that by setting
* initial_index to q->num_buffers
*/
fileio->initial_index = q->num_buffers;
fileio->cur_index = q->num_buffers;
}
/*
* Start streaming.
*/
ret = vb2_core_streamon(q, q->type);
if (ret)
goto err_reqbufs;
return ret;
err_reqbufs:
fileio->count = 0;
vb2_core_reqbufs(q, fileio->memory, &fileio->count);
err_kfree:
q->fileio = NULL;
kfree(fileio);
return ret;
}
/**
* __vb2_cleanup_fileio() - free resourced used by file io emulator
* @q: videobuf2 queue
*/
static int __vb2_cleanup_fileio(struct vb2_queue *q)
{
struct vb2_fileio_data *fileio = q->fileio;
if (fileio) {
vb2_core_streamoff(q, q->type);
q->fileio = NULL;
fileio->count = 0;
vb2_core_reqbufs(q, fileio->memory, &fileio->count);
kfree(fileio->b);
kfree(fileio);
dprintk(3, "file io emulator closed\n");
}
return 0;
}
/**
* __vb2_perform_fileio() - perform a single file io (read or write) operation
* @q: videobuf2 queue
* @data: pointed to target userspace buffer
* @count: number of bytes to read or write
* @ppos: file handle position tracking pointer
* @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
* @read: access mode selector (1 means read, 0 means write)
*/
static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
loff_t *ppos, int nonblock, int read)
{
struct vb2_fileio_data *fileio;
struct vb2_fileio_buf *buf;
bool is_multiplanar = q->is_multiplanar;
/*
* When using write() to write data to an output video node the vb2 core
* should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
* else is able to provide this information with the write() operation.
*/
bool copy_timestamp = !read && q->copy_timestamp;
int ret, index;
dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
read ? "read" : "write", (long)*ppos, count,
nonblock ? "non" : "");
if (!data)
return -EINVAL;
/*
* Initialize emulator on first call.
*/
if (!vb2_fileio_is_active(q)) {
ret = __vb2_init_fileio(q, read);
dprintk(3, "vb2_init_fileio result: %d\n", ret);
if (ret)
return ret;
}
fileio = q->fileio;
/*
* Check if we need to dequeue the buffer.
*/
index = fileio->cur_index;
if (index >= q->num_buffers) {
struct vb2_buffer *b = fileio->b;
/*
* Call vb2_dqbuf to get buffer back.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
ret = vb2_core_dqbuf(q, b, nonblock);
dprintk(5, "vb2_dqbuf result: %d\n", ret);
if (ret)
return ret;
fileio->dq_count += 1;
fileio->cur_index = index = b->index;
buf = &fileio->bufs[index];
/*
* Get number of bytes filled by the driver
*/
buf->pos = 0;
buf->queued = 0;
buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
: vb2_plane_size(q->bufs[index], 0);
/* Compensate for data_offset on read in the multiplanar case. */
if (is_multiplanar && read &&
b->planes[0].data_offset < buf->size) {
buf->pos = b->planes[0].data_offset;
buf->size -= buf->pos;
}
} else {
buf = &fileio->bufs[index];
}
/*
* Limit count on last few bytes of the buffer.
*/
if (buf->pos + count > buf->size) {
count = buf->size - buf->pos;
dprintk(5, "reducing read count: %zd\n", count);
}
/*
* Transfer data to userspace.
*/
dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
count, index, buf->pos);
if (read)
ret = copy_to_user(data, buf->vaddr + buf->pos, count);
else
ret = copy_from_user(buf->vaddr + buf->pos, data, count);
if (ret) {
dprintk(3, "error copying data\n");
return -EFAULT;
}
/*
* Update counters.
*/
buf->pos += count;
*ppos += count;
/*
* Queue next buffer if required.
*/
if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
struct vb2_buffer *b = fileio->b;
/*
* Check if this is the last buffer to read.
*/
if (read && fileio->read_once && fileio->dq_count == 1) {
dprintk(3, "read limit reached\n");
return __vb2_cleanup_fileio(q);
}
/*
* Call vb2_qbuf and give buffer to the driver.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
b->index = index;
b->planes[0].bytesused = buf->pos;
if (copy_timestamp)
b->timestamp = ktime_get_ns();
ret = vb2_core_qbuf(q, index, b);
dprintk(5, "vb2_dbuf result: %d\n", ret);
if (ret)
return ret;
/*
* Buffer has been queued, update the status
*/
buf->pos = 0;
buf->queued = 1;
buf->size = vb2_plane_size(q->bufs[index], 0);
fileio->q_count += 1;
/*
* If we are queuing up buffers for the first time, then
* increase initial_index by one.
*/
if (fileio->initial_index < q->num_buffers)
fileio->initial_index++;
/*
* The next buffer to use is either a buffer that's going to be
* queued for the first time (initial_index < q->num_buffers)
* or it is equal to q->num_buffers, meaning that the next
* time we need to dequeue a buffer since we've now queued up
* all the 'first time' buffers.
*/
fileio->cur_index = fileio->initial_index;
}
/*
* Return proper number of bytes processed.
*/
if (ret == 0)
ret = count;
return ret;
}
size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
loff_t *ppos, int nonblocking)
{
return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
}
EXPORT_SYMBOL_GPL(vb2_read);
size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
loff_t *ppos, int nonblocking)
{
return __vb2_perform_fileio(q, (char __user *) data, count,
ppos, nonblocking, 0);
}
EXPORT_SYMBOL_GPL(vb2_write);
struct vb2_threadio_data {
struct task_struct *thread;
vb2_thread_fnc fnc;
void *priv;
bool stop;
};
static int vb2_thread(void *data)
{
struct vb2_queue *q = data;
struct vb2_threadio_data *threadio = q->threadio;
struct vb2_fileio_data *fileio = q->fileio;
bool copy_timestamp = false;
int prequeue = 0;
int index = 0;
int ret = 0;
if (q->is_output) {
prequeue = q->num_buffers;
copy_timestamp = q->copy_timestamp;
}
set_freezable();
for (;;) {
struct vb2_buffer *vb;
struct vb2_buffer *b = fileio->b;
/*
* Call vb2_dqbuf to get buffer back.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
if (prequeue) {
b->index = index++;
prequeue--;
} else {
call_void_qop(q, wait_finish, q);
if (!threadio->stop)
ret = vb2_core_dqbuf(q, b, 0);
call_void_qop(q, wait_prepare, q);
dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
}
if (ret || threadio->stop)
break;
try_to_freeze();
vb = q->bufs[b->index];
if (b->state == VB2_BUF_STATE_DONE)
if (threadio->fnc(vb, threadio->priv))
break;
call_void_qop(q, wait_finish, q);
if (copy_timestamp)
b->timestamp = ktime_get_ns();;
if (!threadio->stop)
ret = vb2_core_qbuf(q, b->index, b);
call_void_qop(q, wait_prepare, q);
if (ret || threadio->stop)
break;
}
/* Hmm, linux becomes *very* unhappy without this ... */
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
}
return 0;
}
/*
* This function should not be used for anything else but the videobuf2-dvb
* support. If you think you have another good use-case for this, then please
* contact the linux-media mailinglist first.
*/
int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
const char *thread_name)
{
struct vb2_threadio_data *threadio;
int ret = 0;
if (q->threadio)
return -EBUSY;
if (vb2_is_busy(q))
return -EBUSY;
if (WARN_ON(q->fileio))
return -EBUSY;
threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
if (threadio == NULL)
return -ENOMEM;
threadio->fnc = fnc;
threadio->priv = priv;
ret = __vb2_init_fileio(q, !q->is_output);
dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
if (ret)
goto nomem;
q->threadio = threadio;
threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
if (IS_ERR(threadio->thread)) {
ret = PTR_ERR(threadio->thread);
threadio->thread = NULL;
goto nothread;
}
return 0;
nothread:
__vb2_cleanup_fileio(q);
nomem:
kfree(threadio);
return ret;
}
EXPORT_SYMBOL_GPL(vb2_thread_start);
int vb2_thread_stop(struct vb2_queue *q)
{
struct vb2_threadio_data *threadio = q->threadio;
int err;
if (threadio == NULL)
return 0;
threadio->stop = true;
/* Wake up all pending sleeps in the thread */
vb2_queue_error(q);
err = kthread_stop(threadio->thread);
__vb2_cleanup_fileio(q);