unsigned long plane_sizes[VIDEO_MAX_PLANES];
int ret = 0;
+ if (q->fileio) {
+ dprintk(1, "reqbufs: file io in progress\n");
+ return -EBUSY;
+ }
+
if (req->memory != V4L2_MEMORY_MMAP
&& req->memory != V4L2_MEMORY_USERPTR) {
dprintk(1, "reqbufs: unsupported memory type\n");
struct vb2_buffer *vb;
int ret = 0;
+ if (q->fileio) {
+ dprintk(1, "qbuf: file io in progress\n");
+ return -EBUSY;
+ }
+
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
return -EINVAL;
struct vb2_buffer *vb = NULL;
int ret;
+ if (q->fileio) {
+ dprintk(1, "dqbuf: file io in progress\n");
+ return -EBUSY;
+ }
+
if (b->type != q->type) {
dprintk(1, "dqbuf: invalid buffer type\n");
return -EINVAL;
{
struct vb2_buffer *vb;
+ if (q->fileio) {
+ dprintk(1, "streamon: file io in progress\n");
+ return -EBUSY;
+ }
+
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
return -EINVAL;
*/
int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
+ if (q->fileio) {
+ dprintk(1, "streamoff: file io in progress\n");
+ return -EBUSY;
+ }
+
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
return -EINVAL;
}
EXPORT_SYMBOL_GPL(vb2_mmap);
+static int __vb2_init_fileio(struct vb2_queue *q, int read);
+static int __vb2_cleanup_fileio(struct vb2_queue *q);
/**
* vb2_poll() - implements poll userspace operation
unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
{
unsigned long flags;
+ unsigned int ret;
struct vb2_buffer *vb = NULL;
+ /*
+ * Start file io emulator if streaming api has not been used yet.
+ */
+ if (q->num_buffers == 0 && q->fileio == NULL) {
+ if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) {
+ ret = __vb2_init_fileio(q, 1);
+ if (ret)
+ return ret;
+ }
+ if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) {
+ ret = __vb2_init_fileio(q, 0);
+ if (ret)
+ return ret;
+ /*
+ * Write to OUTPUT queue can be done immediately.
+ */
+ return POLLOUT | POLLWRNORM;
+ }
+ }
+
/*
* There is nothing to wait for if no buffers have already been queued.
*/
*/
void vb2_queue_release(struct vb2_queue *q)
{
+ __vb2_cleanup_fileio(q);
__vb2_queue_cancel(q);
__vb2_queue_free(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_release);
+/**
+ * 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
+ *
+ * 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 {
+ struct v4l2_requestbuffers req;
+ struct v4l2_buffer b;
+ struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
+ unsigned int index;
+ unsigned int q_count;
+ unsigned int dq_count;
+ unsigned int flags;
+};
+
+/**
+ * __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 ((read && !(q->io_modes & VB2_READ)) ||
+ (!read && !(q->io_modes & VB2_WRITE)))
+ BUG();
+
+ /*
+ * 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, flags %08x\n",
+ (read) ? "read" : "write", count, q->io_flags);
+
+ fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
+ if (fileio == NULL)
+ return -ENOMEM;
+
+ fileio->flags = q->io_flags;
+
+ /*
+ * Request buffers and use MMAP type to force driver
+ * to allocate buffers by itself.
+ */
+ fileio->req.count = count;
+ fileio->req.memory = V4L2_MEMORY_MMAP;
+ fileio->req.type = q->type;
+ ret = vb2_reqbufs(q, &fileio->req);
+ if (ret)
+ goto err_kfree;
+
+ /*
+ * Check if plane_count is correct
+ * (multiplane buffers are not supported).
+ */
+ if (q->bufs[0]->num_planes != 1) {
+ fileio->req.count = 0;
+ 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)
+ 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 v4l2_buffer *b = &fileio->b;
+ memset(b, 0, sizeof(*b));
+ b->type = q->type;
+ b->memory = q->memory;
+ b->index = i;
+ ret = vb2_qbuf(q, b);
+ if (ret)
+ goto err_reqbufs;
+ fileio->bufs[i].queued = 1;
+ }
+
+ /*
+ * Start streaming.
+ */
+ ret = vb2_streamon(q, q->type);
+ if (ret)
+ goto err_reqbufs;
+ }
+
+ q->fileio = fileio;
+
+ return ret;
+
+err_reqbufs:
+ vb2_reqbufs(q, &fileio->req);
+
+err_kfree:
+ 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) {
+ /*
+ * Hack fileio context to enable direct calls to vb2 ioctl
+ * interface.
+ */
+ q->fileio = NULL;
+
+ vb2_streamoff(q, q->type);
+ fileio->req.count = 0;
+ vb2_reqbufs(q, &fileio->req);
+ 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;
+ int ret, index;
+
+ dprintk(3, "file io: mode %s, offset %ld, count %ld, %sblocking\n",
+ read ? "read" : "write", (long)*ppos, count,
+ nonblock ? "non" : "");
+
+ if (!data)
+ return -EINVAL;
+
+ /*
+ * Initialize emulator on first call.
+ */
+ if (!q->fileio) {
+ ret = __vb2_init_fileio(q, read);
+ dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
+ if (ret)
+ return ret;
+ }
+ fileio = q->fileio;
+
+ /*
+ * Hack fileio context to enable direct calls to vb2 ioctl interface.
+ * The pointer will be restored before returning from this function.
+ */
+ q->fileio = NULL;
+
+ index = fileio->index;
+ buf = &fileio->bufs[index];
+
+ /*
+ * Check if we need to dequeue the buffer.
+ */
+ if (buf->queued) {
+ struct vb2_buffer *vb;
+
+ /*
+ * Call vb2_dqbuf to get buffer back.
+ */
+ memset(&fileio->b, 0, sizeof(fileio->b));
+ fileio->b.type = q->type;
+ fileio->b.memory = q->memory;
+ fileio->b.index = index;
+ ret = vb2_dqbuf(q, &fileio->b, nonblock);
+ dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+ fileio->dq_count += 1;
+
+ /*
+ * Get number of bytes filled by the driver
+ */
+ vb = q->bufs[index];
+ buf->size = vb2_get_plane_payload(vb, 0);
+ buf->queued = 0;
+ }
+
+ /*
+ * 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: %ld\n", count);
+ }
+
+ /*
+ * Transfer data to userspace.
+ */
+ dprintk(3, "file io: copying %ld 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, "file io: error copying data\n");
+ ret = -EFAULT;
+ goto end;
+ }
+
+ /*
+ * Update counters.
+ */
+ buf->pos += count;
+ *ppos += count;
+
+ /*
+ * Queue next buffer if required.
+ */
+ if (buf->pos == buf->size ||
+ (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
+ /*
+ * Check if this is the last buffer to read.
+ */
+ if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
+ fileio->dq_count == 1) {
+ dprintk(3, "file io: read limit reached\n");
+ /*
+ * Restore fileio pointer and release the context.
+ */
+ q->fileio = fileio;
+ return __vb2_cleanup_fileio(q);
+ }
+
+ /*
+ * Call vb2_qbuf and give buffer to the driver.
+ */
+ memset(&fileio->b, 0, sizeof(fileio->b));
+ fileio->b.type = q->type;
+ fileio->b.memory = q->memory;
+ fileio->b.index = index;
+ fileio->b.bytesused = buf->pos;
+ ret = vb2_qbuf(q, &fileio->b);
+ dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+
+ /*
+ * Buffer has been queued, update the status
+ */
+ buf->pos = 0;
+ buf->queued = 1;
+ buf->size = q->bufs[0]->v4l2_planes[0].length;
+ fileio->q_count += 1;
+
+ /*
+ * Switch to the next buffer
+ */
+ fileio->index = (index + 1) % q->num_buffers;
+
+ /*
+ * Start streaming if required.
+ */
+ if (!read && !q->streaming) {
+ ret = vb2_streamon(q, q->type);
+ if (ret)
+ goto end;
+ }
+ }
+
+ /*
+ * Return proper number of bytes processed.
+ */
+ if (ret == 0)
+ ret = count;
+end:
+ /*
+ * Restore the fileio context and block vb2 ioctl interface.
+ */
+ q->fileio = fileio;
+ 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, char __user *data, size_t count,
+ loff_t *ppos, int nonblocking)
+{
+ return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0);
+}
+EXPORT_SYMBOL_GPL(vb2_write);
+
MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski");
MODULE_LICENSE("GPL");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff