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-rw-r--r--include/media/videobuf2-core.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index cb97c224be73..ef9b64398c8c 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -427,6 +427,16 @@ struct vb2_buf_ops {
* @dev: device to use for the default allocation context if the driver
* doesn't fill in the @alloc_devs array.
* @dma_attrs: DMA attributes to use for the DMA.
+ * @bidirectional: when this flag is set the DMA direction for the buffers of
+ * this queue will be overridden with DMA_BIDIRECTIONAL direction.
+ * This is useful in cases where the hardware (firmware) writes to
+ * a buffer which is mapped as read (DMA_TO_DEVICE), or reads from
+ * buffer which is mapped for write (DMA_FROM_DEVICE) in order
+ * to satisfy some internal hardware restrictions or adds a padding
+ * needed by the processing algorithm. In case the DMA mapping is
+ * not bidirectional but the hardware (firmware) trying to access
+ * the buffer (in the opposite direction) this could lead to an
+ * IOMMU protection faults.
* @fileio_read_once: report EOF after reading the first buffer
* @fileio_write_immediately: queue buffer after each write() call
* @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
@@ -465,6 +475,7 @@ struct vb2_buf_ops {
* Private elements (won't appear at the uAPI book):
* @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
* @memory: current memory type used
+ * @dma_dir: DMA mapping direction.
* @bufs: videobuf buffer structures
* @num_buffers: number of allocated/used buffers
* @queued_list: list of buffers currently queued from userspace
@@ -495,6 +506,7 @@ struct vb2_queue {
unsigned int io_modes;
struct device *dev;
unsigned long dma_attrs;
+ unsigned bidirectional:1;
unsigned fileio_read_once:1;
unsigned fileio_write_immediately:1;
unsigned allow_zero_bytesused:1;
@@ -516,6 +528,7 @@ struct vb2_queue {
/* private: internal use only */
struct mutex mmap_lock;
unsigned int memory;
+ enum dma_data_direction dma_dir;
struct vb2_buffer *bufs[VB2_MAX_FRAME];
unsigned int num_buffers;