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- /*
- * generic helper functions for handling video4linux capture buffers
- *
- * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
- *
- * Highly based on video-buf written originally by:
- * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
- * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
- * (c) 2006 Ted Walther and John Sokol
- *
- * 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; either version 2
- */
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/moduleparam.h>
- #include <linux/mm.h>
- #include <linux/sched.h>
- #include <linux/slab.h>
- #include <linux/interrupt.h>
- #include <media/videobuf-core.h>
- #define MAGIC_BUFFER 0x20070728
- #define MAGIC_CHECK(is, should) \
- do { \
- if (unlikely((is) != (should))) { \
- printk(KERN_ERR \
- "magic mismatch: %x (expected %x)\n", \
- is, should); \
- BUG(); \
- } \
- } while (0)
- static int debug;
- module_param(debug, int, 0644);
- MODULE_DESCRIPTION("helper module to manage video4linux buffers");
- MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@kernel.org>");
- MODULE_LICENSE("GPL");
- #define dprintk(level, fmt, arg...) \
- do { \
- if (debug >= level) \
- printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
- } while (0)
- /* --------------------------------------------------------------------- */
- #define CALL(q, f, arg...) \
- ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
- #define CALLPTR(q, f, arg...) \
- ((q->int_ops->f) ? q->int_ops->f(arg) : NULL)
- struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
- {
- struct videobuf_buffer *vb;
- BUG_ON(q->msize < sizeof(*vb));
- if (!q->int_ops || !q->int_ops->alloc_vb) {
- printk(KERN_ERR "No specific ops defined!\n");
- BUG();
- }
- vb = q->int_ops->alloc_vb(q->msize);
- if (NULL != vb) {
- init_waitqueue_head(&vb->done);
- vb->magic = MAGIC_BUFFER;
- }
- return vb;
- }
- EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
- static int state_neither_active_nor_queued(struct videobuf_queue *q,
- struct videobuf_buffer *vb)
- {
- unsigned long flags;
- bool rc;
- spin_lock_irqsave(q->irqlock, flags);
- rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
- spin_unlock_irqrestore(q->irqlock, flags);
- return rc;
- };
- int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
- int non_blocking, int intr)
- {
- bool is_ext_locked;
- int ret = 0;
- MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- if (non_blocking) {
- if (state_neither_active_nor_queued(q, vb))
- return 0;
- return -EAGAIN;
- }
- is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
- /* Release vdev lock to prevent this wait from blocking outside access to
- the device. */
- if (is_ext_locked)
- mutex_unlock(q->ext_lock);
- if (intr)
- ret = wait_event_interruptible(vb->done,
- state_neither_active_nor_queued(q, vb));
- else
- wait_event(vb->done, state_neither_active_nor_queued(q, vb));
- /* Relock */
- if (is_ext_locked)
- mutex_lock(q->ext_lock);
- return ret;
- }
- EXPORT_SYMBOL_GPL(videobuf_waiton);
- int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
- struct v4l2_framebuffer *fbuf)
- {
- MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- return CALL(q, iolock, q, vb, fbuf);
- }
- EXPORT_SYMBOL_GPL(videobuf_iolock);
- void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
- struct videobuf_buffer *buf)
- {
- if (q->int_ops->vaddr)
- return q->int_ops->vaddr(buf);
- return NULL;
- }
- EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
- /* --------------------------------------------------------------------- */
- void videobuf_queue_core_init(struct videobuf_queue *q,
- const struct videobuf_queue_ops *ops,
- struct device *dev,
- spinlock_t *irqlock,
- enum v4l2_buf_type type,
- enum v4l2_field field,
- unsigned int msize,
- void *priv,
- struct videobuf_qtype_ops *int_ops,
- struct mutex *ext_lock)
- {
- BUG_ON(!q);
- memset(q, 0, sizeof(*q));
- q->irqlock = irqlock;
- q->ext_lock = ext_lock;
- q->dev = dev;
- q->type = type;
- q->field = field;
- q->msize = msize;
- q->ops = ops;
- q->priv_data = priv;
- q->int_ops = int_ops;
- /* All buffer operations are mandatory */
- BUG_ON(!q->ops->buf_setup);
- BUG_ON(!q->ops->buf_prepare);
- BUG_ON(!q->ops->buf_queue);
- BUG_ON(!q->ops->buf_release);
- /* Lock is mandatory for queue_cancel to work */
- BUG_ON(!irqlock);
- /* Having implementations for abstract methods are mandatory */
- BUG_ON(!q->int_ops);
- mutex_init(&q->vb_lock);
- init_waitqueue_head(&q->wait);
- INIT_LIST_HEAD(&q->stream);
- }
- EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
- /* Locking: Only usage in bttv unsafe find way to remove */
- int videobuf_queue_is_busy(struct videobuf_queue *q)
- {
- int i;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- if (q->streaming) {
- dprintk(1, "busy: streaming active\n");
- return 1;
- }
- if (q->reading) {
- dprintk(1, "busy: pending read #1\n");
- return 1;
- }
- if (q->read_buf) {
- dprintk(1, "busy: pending read #2\n");
- return 1;
- }
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
- if (q->bufs[i]->map) {
- dprintk(1, "busy: buffer #%d mapped\n", i);
- return 1;
- }
- if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
- dprintk(1, "busy: buffer #%d queued\n", i);
- return 1;
- }
- if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
- dprintk(1, "busy: buffer #%d avtive\n", i);
- return 1;
- }
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
- /*
- * __videobuf_free() - free all the buffers and their control structures
- *
- * This function can only be called if streaming/reading is off, i.e. no buffers
- * are under control of the driver.
- */
- /* Locking: Caller holds q->vb_lock */
- static int __videobuf_free(struct videobuf_queue *q)
- {
- int i;
- dprintk(1, "%s\n", __func__);
- if (!q)
- return 0;
- if (q->streaming || q->reading) {
- dprintk(1, "Cannot free buffers when streaming or reading\n");
- return -EBUSY;
- }
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- for (i = 0; i < VIDEO_MAX_FRAME; i++)
- if (q->bufs[i] && q->bufs[i]->map) {
- dprintk(1, "Cannot free mmapped buffers\n");
- return -EBUSY;
- }
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
- q->ops->buf_release(q, q->bufs[i]);
- kfree(q->bufs[i]);
- q->bufs[i] = NULL;
- }
- return 0;
- }
- /* Locking: Caller holds q->vb_lock */
- void videobuf_queue_cancel(struct videobuf_queue *q)
- {
- unsigned long flags = 0;
- int i;
- q->streaming = 0;
- q->reading = 0;
- wake_up_interruptible_sync(&q->wait);
- /* remove queued buffers from list */
- spin_lock_irqsave(q->irqlock, flags);
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
- if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
- list_del(&q->bufs[i]->queue);
- q->bufs[i]->state = VIDEOBUF_ERROR;
- wake_up_all(&q->bufs[i]->done);
- }
- }
- spin_unlock_irqrestore(q->irqlock, flags);
- /* free all buffers + clear queue */
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
- q->ops->buf_release(q, q->bufs[i]);
- }
- INIT_LIST_HEAD(&q->stream);
- }
- EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
- /* --------------------------------------------------------------------- */
- /* Locking: Caller holds q->vb_lock */
- enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
- {
- enum v4l2_field field = q->field;
- BUG_ON(V4L2_FIELD_ANY == field);
- if (V4L2_FIELD_ALTERNATE == field) {
- if (V4L2_FIELD_TOP == q->last) {
- field = V4L2_FIELD_BOTTOM;
- q->last = V4L2_FIELD_BOTTOM;
- } else {
- field = V4L2_FIELD_TOP;
- q->last = V4L2_FIELD_TOP;
- }
- }
- return field;
- }
- EXPORT_SYMBOL_GPL(videobuf_next_field);
- /* Locking: Caller holds q->vb_lock */
- static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
- struct videobuf_buffer *vb, enum v4l2_buf_type type)
- {
- MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- b->index = vb->i;
- b->type = type;
- b->memory = vb->memory;
- switch (b->memory) {
- case V4L2_MEMORY_MMAP:
- b->m.offset = vb->boff;
- b->length = vb->bsize;
- break;
- case V4L2_MEMORY_USERPTR:
- b->m.userptr = vb->baddr;
- b->length = vb->bsize;
- break;
- case V4L2_MEMORY_OVERLAY:
- b->m.offset = vb->boff;
- break;
- case V4L2_MEMORY_DMABUF:
- /* DMABUF is not handled in videobuf framework */
- break;
- }
- b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
- if (vb->map)
- b->flags |= V4L2_BUF_FLAG_MAPPED;
- switch (vb->state) {
- case VIDEOBUF_PREPARED:
- case VIDEOBUF_QUEUED:
- case VIDEOBUF_ACTIVE:
- b->flags |= V4L2_BUF_FLAG_QUEUED;
- break;
- case VIDEOBUF_ERROR:
- b->flags |= V4L2_BUF_FLAG_ERROR;
- /* fall through */
- case VIDEOBUF_DONE:
- b->flags |= V4L2_BUF_FLAG_DONE;
- break;
- case VIDEOBUF_NEEDS_INIT:
- case VIDEOBUF_IDLE:
- /* nothing */
- break;
- }
- b->field = vb->field;
- b->timestamp = vb->ts;
- b->bytesused = vb->size;
- b->sequence = vb->field_count >> 1;
- }
- int videobuf_mmap_free(struct videobuf_queue *q)
- {
- int ret;
- videobuf_queue_lock(q);
- ret = __videobuf_free(q);
- videobuf_queue_unlock(q);
- return ret;
- }
- EXPORT_SYMBOL_GPL(videobuf_mmap_free);
- /* Locking: Caller holds q->vb_lock */
- int __videobuf_mmap_setup(struct videobuf_queue *q,
- unsigned int bcount, unsigned int bsize,
- enum v4l2_memory memory)
- {
- unsigned int i;
- int err;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- err = __videobuf_free(q);
- if (0 != err)
- return err;
- /* Allocate and initialize buffers */
- for (i = 0; i < bcount; i++) {
- q->bufs[i] = videobuf_alloc_vb(q);
- if (NULL == q->bufs[i])
- break;
- q->bufs[i]->i = i;
- q->bufs[i]->memory = memory;
- q->bufs[i]->bsize = bsize;
- switch (memory) {
- case V4L2_MEMORY_MMAP:
- q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
- break;
- case V4L2_MEMORY_USERPTR:
- case V4L2_MEMORY_OVERLAY:
- case V4L2_MEMORY_DMABUF:
- /* nothing */
- break;
- }
- }
- if (!i)
- return -ENOMEM;
- dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
- return i;
- }
- EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
- int videobuf_mmap_setup(struct videobuf_queue *q,
- unsigned int bcount, unsigned int bsize,
- enum v4l2_memory memory)
- {
- int ret;
- videobuf_queue_lock(q);
- ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
- videobuf_queue_unlock(q);
- return ret;
- }
- EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
- int videobuf_reqbufs(struct videobuf_queue *q,
- struct v4l2_requestbuffers *req)
- {
- unsigned int size, count;
- int retval;
- if (req->memory != V4L2_MEMORY_MMAP &&
- req->memory != V4L2_MEMORY_USERPTR &&
- req->memory != V4L2_MEMORY_OVERLAY) {
- dprintk(1, "reqbufs: memory type invalid\n");
- return -EINVAL;
- }
- videobuf_queue_lock(q);
- if (req->type != q->type) {
- dprintk(1, "reqbufs: queue type invalid\n");
- retval = -EINVAL;
- goto done;
- }
- if (q->streaming) {
- dprintk(1, "reqbufs: streaming already exists\n");
- retval = -EBUSY;
- goto done;
- }
- if (!list_empty(&q->stream)) {
- dprintk(1, "reqbufs: stream running\n");
- retval = -EBUSY;
- goto done;
- }
- if (req->count == 0) {
- dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
- retval = __videobuf_free(q);
- goto done;
- }
- count = req->count;
- if (count > VIDEO_MAX_FRAME)
- count = VIDEO_MAX_FRAME;
- size = 0;
- q->ops->buf_setup(q, &count, &size);
- dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
- count, size,
- (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
- retval = __videobuf_mmap_setup(q, count, size, req->memory);
- if (retval < 0) {
- dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
- goto done;
- }
- req->count = retval;
- retval = 0;
- done:
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_reqbufs);
- int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
- {
- int ret = -EINVAL;
- videobuf_queue_lock(q);
- if (unlikely(b->type != q->type)) {
- dprintk(1, "querybuf: Wrong type.\n");
- goto done;
- }
- if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
- dprintk(1, "querybuf: index out of range.\n");
- goto done;
- }
- if (unlikely(NULL == q->bufs[b->index])) {
- dprintk(1, "querybuf: buffer is null.\n");
- goto done;
- }
- videobuf_status(q, b, q->bufs[b->index], q->type);
- ret = 0;
- done:
- videobuf_queue_unlock(q);
- return ret;
- }
- EXPORT_SYMBOL_GPL(videobuf_querybuf);
- int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
- {
- struct videobuf_buffer *buf;
- enum v4l2_field field;
- unsigned long flags = 0;
- int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- if (b->memory == V4L2_MEMORY_MMAP)
- down_read(¤t->mm->mmap_sem);
- videobuf_queue_lock(q);
- retval = -EBUSY;
- if (q->reading) {
- dprintk(1, "qbuf: Reading running...\n");
- goto done;
- }
- retval = -EINVAL;
- if (b->type != q->type) {
- dprintk(1, "qbuf: Wrong type.\n");
- goto done;
- }
- if (b->index >= VIDEO_MAX_FRAME) {
- dprintk(1, "qbuf: index out of range.\n");
- goto done;
- }
- buf = q->bufs[b->index];
- if (NULL == buf) {
- dprintk(1, "qbuf: buffer is null.\n");
- goto done;
- }
- MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
- if (buf->memory != b->memory) {
- dprintk(1, "qbuf: memory type is wrong.\n");
- goto done;
- }
- if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
- dprintk(1, "qbuf: buffer is already queued or active.\n");
- goto done;
- }
- switch (b->memory) {
- case V4L2_MEMORY_MMAP:
- if (0 == buf->baddr) {
- dprintk(1, "qbuf: mmap requested but buffer addr is zero!\n");
- goto done;
- }
- if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
- || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
- || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT
- || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) {
- buf->size = b->bytesused;
- buf->field = b->field;
- buf->ts = b->timestamp;
- }
- break;
- case V4L2_MEMORY_USERPTR:
- if (b->length < buf->bsize) {
- dprintk(1, "qbuf: buffer length is not enough\n");
- goto done;
- }
- if (VIDEOBUF_NEEDS_INIT != buf->state &&
- buf->baddr != b->m.userptr)
- q->ops->buf_release(q, buf);
- buf->baddr = b->m.userptr;
- break;
- case V4L2_MEMORY_OVERLAY:
- buf->boff = b->m.offset;
- break;
- default:
- dprintk(1, "qbuf: wrong memory type\n");
- goto done;
- }
- dprintk(1, "qbuf: requesting next field\n");
- field = videobuf_next_field(q);
- retval = q->ops->buf_prepare(q, buf, field);
- if (0 != retval) {
- dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
- goto done;
- }
- list_add_tail(&buf->stream, &q->stream);
- if (q->streaming) {
- spin_lock_irqsave(q->irqlock, flags);
- q->ops->buf_queue(q, buf);
- spin_unlock_irqrestore(q->irqlock, flags);
- }
- dprintk(1, "qbuf: succeeded\n");
- retval = 0;
- wake_up_interruptible_sync(&q->wait);
- done:
- videobuf_queue_unlock(q);
- if (b->memory == V4L2_MEMORY_MMAP)
- up_read(¤t->mm->mmap_sem);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_qbuf);
- /* Locking: Caller holds q->vb_lock */
- static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
- {
- int retval;
- checks:
- if (!q->streaming) {
- dprintk(1, "next_buffer: Not streaming\n");
- retval = -EINVAL;
- goto done;
- }
- if (list_empty(&q->stream)) {
- if (noblock) {
- retval = -EAGAIN;
- dprintk(2, "next_buffer: no buffers to dequeue\n");
- goto done;
- } else {
- dprintk(2, "next_buffer: waiting on buffer\n");
- /* Drop lock to avoid deadlock with qbuf */
- videobuf_queue_unlock(q);
- /* Checking list_empty and streaming is safe without
- * locks because we goto checks to validate while
- * holding locks before proceeding */
- retval = wait_event_interruptible(q->wait,
- !list_empty(&q->stream) || !q->streaming);
- videobuf_queue_lock(q);
- if (retval)
- goto done;
- goto checks;
- }
- }
- retval = 0;
- done:
- return retval;
- }
- /* Locking: Caller holds q->vb_lock */
- static int stream_next_buffer(struct videobuf_queue *q,
- struct videobuf_buffer **vb, int nonblocking)
- {
- int retval;
- struct videobuf_buffer *buf = NULL;
- retval = stream_next_buffer_check_queue(q, nonblocking);
- if (retval)
- goto done;
- buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
- retval = videobuf_waiton(q, buf, nonblocking, 1);
- if (retval < 0)
- goto done;
- *vb = buf;
- done:
- return retval;
- }
- int videobuf_dqbuf(struct videobuf_queue *q,
- struct v4l2_buffer *b, int nonblocking)
- {
- struct videobuf_buffer *buf = NULL;
- int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- memset(b, 0, sizeof(*b));
- videobuf_queue_lock(q);
- retval = stream_next_buffer(q, &buf, nonblocking);
- if (retval < 0) {
- dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
- goto done;
- }
- switch (buf->state) {
- case VIDEOBUF_ERROR:
- dprintk(1, "dqbuf: state is error\n");
- break;
- case VIDEOBUF_DONE:
- dprintk(1, "dqbuf: state is done\n");
- break;
- default:
- dprintk(1, "dqbuf: state invalid\n");
- retval = -EINVAL;
- goto done;
- }
- CALL(q, sync, q, buf);
- videobuf_status(q, b, buf, q->type);
- list_del(&buf->stream);
- buf->state = VIDEOBUF_IDLE;
- b->flags &= ~V4L2_BUF_FLAG_DONE;
- done:
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_dqbuf);
- int videobuf_streamon(struct videobuf_queue *q)
- {
- struct videobuf_buffer *buf;
- unsigned long flags = 0;
- int retval;
- videobuf_queue_lock(q);
- retval = -EBUSY;
- if (q->reading)
- goto done;
- retval = 0;
- if (q->streaming)
- goto done;
- q->streaming = 1;
- spin_lock_irqsave(q->irqlock, flags);
- list_for_each_entry(buf, &q->stream, stream)
- if (buf->state == VIDEOBUF_PREPARED)
- q->ops->buf_queue(q, buf);
- spin_unlock_irqrestore(q->irqlock, flags);
- wake_up_interruptible_sync(&q->wait);
- done:
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_streamon);
- /* Locking: Caller holds q->vb_lock */
- static int __videobuf_streamoff(struct videobuf_queue *q)
- {
- if (!q->streaming)
- return -EINVAL;
- videobuf_queue_cancel(q);
- return 0;
- }
- int videobuf_streamoff(struct videobuf_queue *q)
- {
- int retval;
- videobuf_queue_lock(q);
- retval = __videobuf_streamoff(q);
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_streamoff);
- /* Locking: Caller holds q->vb_lock */
- static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
- char __user *data,
- size_t count, loff_t *ppos)
- {
- enum v4l2_field field;
- unsigned long flags = 0;
- int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- /* setup stuff */
- q->read_buf = videobuf_alloc_vb(q);
- if (NULL == q->read_buf)
- return -ENOMEM;
- q->read_buf->memory = V4L2_MEMORY_USERPTR;
- q->read_buf->baddr = (unsigned long)data;
- q->read_buf->bsize = count;
- field = videobuf_next_field(q);
- retval = q->ops->buf_prepare(q, q->read_buf, field);
- if (0 != retval)
- goto done;
- /* start capture & wait */
- spin_lock_irqsave(q->irqlock, flags);
- q->ops->buf_queue(q, q->read_buf);
- spin_unlock_irqrestore(q->irqlock, flags);
- retval = videobuf_waiton(q, q->read_buf, 0, 0);
- if (0 == retval) {
- CALL(q, sync, q, q->read_buf);
- if (VIDEOBUF_ERROR == q->read_buf->state)
- retval = -EIO;
- else
- retval = q->read_buf->size;
- }
- done:
- /* cleanup */
- q->ops->buf_release(q, q->read_buf);
- kfree(q->read_buf);
- q->read_buf = NULL;
- return retval;
- }
- static int __videobuf_copy_to_user(struct videobuf_queue *q,
- struct videobuf_buffer *buf,
- char __user *data, size_t count,
- int nonblocking)
- {
- void *vaddr = CALLPTR(q, vaddr, buf);
- /* copy to userspace */
- if (count > buf->size - q->read_off)
- count = buf->size - q->read_off;
- if (copy_to_user(data, vaddr + q->read_off, count))
- return -EFAULT;
- return count;
- }
- static int __videobuf_copy_stream(struct videobuf_queue *q,
- struct videobuf_buffer *buf,
- char __user *data, size_t count, size_t pos,
- int vbihack, int nonblocking)
- {
- unsigned int *fc = CALLPTR(q, vaddr, buf);
- if (vbihack) {
- /* dirty, undocumented hack -- pass the frame counter
- * within the last four bytes of each vbi data block.
- * We need that one to maintain backward compatibility
- * to all vbi decoding software out there ... */
- fc += (buf->size >> 2) - 1;
- *fc = buf->field_count >> 1;
- dprintk(1, "vbihack: %d\n", *fc);
- }
- /* copy stuff using the common method */
- count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
- if ((count == -EFAULT) && (pos == 0))
- return -EFAULT;
- return count;
- }
- ssize_t videobuf_read_one(struct videobuf_queue *q,
- char __user *data, size_t count, loff_t *ppos,
- int nonblocking)
- {
- enum v4l2_field field;
- unsigned long flags = 0;
- unsigned size = 0, nbufs = 1;
- int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- videobuf_queue_lock(q);
- q->ops->buf_setup(q, &nbufs, &size);
- if (NULL == q->read_buf &&
- count >= size &&
- !nonblocking) {
- retval = videobuf_read_zerocopy(q, data, count, ppos);
- if (retval >= 0 || retval == -EIO)
- /* ok, all done */
- goto done;
- /* fallback to kernel bounce buffer on failures */
- }
- if (NULL == q->read_buf) {
- /* need to capture a new frame */
- retval = -ENOMEM;
- q->read_buf = videobuf_alloc_vb(q);
- dprintk(1, "video alloc=0x%p\n", q->read_buf);
- if (NULL == q->read_buf)
- goto done;
- q->read_buf->memory = V4L2_MEMORY_USERPTR;
- q->read_buf->bsize = count; /* preferred size */
- field = videobuf_next_field(q);
- retval = q->ops->buf_prepare(q, q->read_buf, field);
- if (0 != retval) {
- kfree(q->read_buf);
- q->read_buf = NULL;
- goto done;
- }
- spin_lock_irqsave(q->irqlock, flags);
- q->ops->buf_queue(q, q->read_buf);
- spin_unlock_irqrestore(q->irqlock, flags);
- q->read_off = 0;
- }
- /* wait until capture is done */
- retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
- if (0 != retval)
- goto done;
- CALL(q, sync, q, q->read_buf);
- if (VIDEOBUF_ERROR == q->read_buf->state) {
- /* catch I/O errors */
- q->ops->buf_release(q, q->read_buf);
- kfree(q->read_buf);
- q->read_buf = NULL;
- retval = -EIO;
- goto done;
- }
- /* Copy to userspace */
- retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
- if (retval < 0)
- goto done;
- q->read_off += retval;
- if (q->read_off == q->read_buf->size) {
- /* all data copied, cleanup */
- q->ops->buf_release(q, q->read_buf);
- kfree(q->read_buf);
- q->read_buf = NULL;
- }
- done:
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_read_one);
- /* Locking: Caller holds q->vb_lock */
- static int __videobuf_read_start(struct videobuf_queue *q)
- {
- enum v4l2_field field;
- unsigned long flags = 0;
- unsigned int count = 0, size = 0;
- int err, i;
- q->ops->buf_setup(q, &count, &size);
- if (count < 2)
- count = 2;
- if (count > VIDEO_MAX_FRAME)
- count = VIDEO_MAX_FRAME;
- size = PAGE_ALIGN(size);
- err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
- if (err < 0)
- return err;
- count = err;
- for (i = 0; i < count; i++) {
- field = videobuf_next_field(q);
- err = q->ops->buf_prepare(q, q->bufs[i], field);
- if (err)
- return err;
- list_add_tail(&q->bufs[i]->stream, &q->stream);
- }
- spin_lock_irqsave(q->irqlock, flags);
- for (i = 0; i < count; i++)
- q->ops->buf_queue(q, q->bufs[i]);
- spin_unlock_irqrestore(q->irqlock, flags);
- q->reading = 1;
- return 0;
- }
- static void __videobuf_read_stop(struct videobuf_queue *q)
- {
- int i;
- videobuf_queue_cancel(q);
- __videobuf_free(q);
- INIT_LIST_HEAD(&q->stream);
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
- kfree(q->bufs[i]);
- q->bufs[i] = NULL;
- }
- q->read_buf = NULL;
- }
- int videobuf_read_start(struct videobuf_queue *q)
- {
- int rc;
- videobuf_queue_lock(q);
- rc = __videobuf_read_start(q);
- videobuf_queue_unlock(q);
- return rc;
- }
- EXPORT_SYMBOL_GPL(videobuf_read_start);
- void videobuf_read_stop(struct videobuf_queue *q)
- {
- videobuf_queue_lock(q);
- __videobuf_read_stop(q);
- videobuf_queue_unlock(q);
- }
- EXPORT_SYMBOL_GPL(videobuf_read_stop);
- void videobuf_stop(struct videobuf_queue *q)
- {
- videobuf_queue_lock(q);
- if (q->streaming)
- __videobuf_streamoff(q);
- if (q->reading)
- __videobuf_read_stop(q);
- videobuf_queue_unlock(q);
- }
- EXPORT_SYMBOL_GPL(videobuf_stop);
- ssize_t videobuf_read_stream(struct videobuf_queue *q,
- char __user *data, size_t count, loff_t *ppos,
- int vbihack, int nonblocking)
- {
- int rc, retval;
- unsigned long flags = 0;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- dprintk(2, "%s\n", __func__);
- videobuf_queue_lock(q);
- retval = -EBUSY;
- if (q->streaming)
- goto done;
- if (!q->reading) {
- retval = __videobuf_read_start(q);
- if (retval < 0)
- goto done;
- }
- retval = 0;
- while (count > 0) {
- /* get / wait for data */
- if (NULL == q->read_buf) {
- q->read_buf = list_entry(q->stream.next,
- struct videobuf_buffer,
- stream);
- list_del(&q->read_buf->stream);
- q->read_off = 0;
- }
- rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
- if (rc < 0) {
- if (0 == retval)
- retval = rc;
- break;
- }
- if (q->read_buf->state == VIDEOBUF_DONE) {
- rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
- retval, vbihack, nonblocking);
- if (rc < 0) {
- retval = rc;
- break;
- }
- retval += rc;
- count -= rc;
- q->read_off += rc;
- } else {
- /* some error */
- q->read_off = q->read_buf->size;
- if (0 == retval)
- retval = -EIO;
- }
- /* requeue buffer when done with copying */
- if (q->read_off == q->read_buf->size) {
- list_add_tail(&q->read_buf->stream,
- &q->stream);
- spin_lock_irqsave(q->irqlock, flags);
- q->ops->buf_queue(q, q->read_buf);
- spin_unlock_irqrestore(q->irqlock, flags);
- q->read_buf = NULL;
- }
- if (retval < 0)
- break;
- }
- done:
- videobuf_queue_unlock(q);
- return retval;
- }
- EXPORT_SYMBOL_GPL(videobuf_read_stream);
- __poll_t videobuf_poll_stream(struct file *file,
- struct videobuf_queue *q,
- poll_table *wait)
- {
- __poll_t req_events = poll_requested_events(wait);
- struct videobuf_buffer *buf = NULL;
- __poll_t rc = 0;
- videobuf_queue_lock(q);
- if (q->streaming) {
- if (!list_empty(&q->stream))
- buf = list_entry(q->stream.next,
- struct videobuf_buffer, stream);
- } else if (req_events & (EPOLLIN | EPOLLRDNORM)) {
- if (!q->reading)
- __videobuf_read_start(q);
- if (!q->reading) {
- rc = EPOLLERR;
- } else if (NULL == q->read_buf) {
- q->read_buf = list_entry(q->stream.next,
- struct videobuf_buffer,
- stream);
- list_del(&q->read_buf->stream);
- q->read_off = 0;
- }
- buf = q->read_buf;
- }
- if (!buf)
- rc = EPOLLERR;
- if (0 == rc) {
- poll_wait(file, &buf->done, wait);
- if (buf->state == VIDEOBUF_DONE ||
- buf->state == VIDEOBUF_ERROR) {
- switch (q->type) {
- case V4L2_BUF_TYPE_VIDEO_OUTPUT:
- case V4L2_BUF_TYPE_VBI_OUTPUT:
- case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
- case V4L2_BUF_TYPE_SDR_OUTPUT:
- rc = EPOLLOUT | EPOLLWRNORM;
- break;
- default:
- rc = EPOLLIN | EPOLLRDNORM;
- break;
- }
- }
- }
- videobuf_queue_unlock(q);
- return rc;
- }
- EXPORT_SYMBOL_GPL(videobuf_poll_stream);
- int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
- {
- int rc = -EINVAL;
- int i;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
- dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
- return -EINVAL;
- }
- videobuf_queue_lock(q);
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- struct videobuf_buffer *buf = q->bufs[i];
- if (buf && buf->memory == V4L2_MEMORY_MMAP &&
- buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
- rc = CALL(q, mmap_mapper, q, buf, vma);
- break;
- }
- }
- videobuf_queue_unlock(q);
- return rc;
- }
- EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
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