// SPDX-License-Identifier: GPL-2.0 /* * generic helper functions for handling video4linux capture buffers * * (c) 2007 Mauro Carvalho Chehab, * * Highly based on video-buf written originally by: * (c) 2001,02 Gerd Knorr * (c) 2006 Mauro Carvalho Chehab, * (c) 2006 Ted Walther and John Sokol */ #include #include #include #include #include #include #include #include #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 "); 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 active\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 = ns_to_timeval(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 = v4l2_timeval_to_ns(&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; poll_wait(file, &buf->done, wait); 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) { 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);