diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst new file mode 100644 index 000000000000..a9b457a4b949 --- /dev/null +++ b/Documentation/driver-api/dma-buf.rst @@ -0,0 +1,73 @@ +Buffer Sharing and Synchronization +================================== + +The dma-buf subsystem provides the framework for sharing buffers for +hardware (DMA) access across multiple device drivers and subsystems, and +for synchronizing asynchronous hardware access. + +This is used, for example, by drm "prime" multi-GPU support, but is of +course not limited to GPU use cases. + +The three main components of this are: (1) dma-buf, representing a +sg_table and exposed to userspace as a file descriptor to allow passing +between devices, (2) fence, which provides a mechanism to signal when +one device as finished access, and (3) reservation, which manages the +shared or exclusive fence(s) associated with the buffer. + +Shared DMA Buffers +------------------ + +.. kernel-doc:: drivers/dma-buf/dma-buf.c + :export: + +.. kernel-doc:: include/linux/dma-buf.h + :internal: + +Reservation Objects +------------------- + +.. kernel-doc:: drivers/dma-buf/reservation.c + :doc: Reservation Object Overview + +.. kernel-doc:: drivers/dma-buf/reservation.c + :export: + +.. kernel-doc:: include/linux/reservation.h + :internal: + +DMA Fences +---------- + +.. kernel-doc:: drivers/dma-buf/dma-fence.c + :export: + +.. kernel-doc:: include/linux/dma-fence.h + :internal: + +Seqno Hardware Fences +~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/dma-buf/seqno-fence.c + :export: + +.. kernel-doc:: include/linux/seqno-fence.h + :internal: + +DMA Fence Array +~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/dma-buf/dma-fence-array.c + :export: + +.. kernel-doc:: include/linux/dma-fence-array.h + :internal: + +DMA Fence uABI/Sync File +~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/dma-buf/sync_file.c + :export: + +.. kernel-doc:: include/linux/sync_file.h + :internal: + diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index 0823a6a52f43..a528178a54a5 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -16,6 +16,7 @@ available subsections can be seen below. basics infrastructure + dma-buf device_link message-based sound diff --git a/Documentation/driver-api/infrastructure.rst b/Documentation/driver-api/infrastructure.rst index a0d65eb49055..0bb0b5fc9512 100644 --- a/Documentation/driver-api/infrastructure.rst +++ b/Documentation/driver-api/infrastructure.rst @@ -46,76 +46,6 @@ Device Drivers Base .. kernel-doc:: drivers/base/bus.c :export: -Buffer Sharing and Synchronization ----------------------------------- - -The dma-buf subsystem provides the framework for sharing buffers for -hardware (DMA) access across multiple device drivers and subsystems, and -for synchronizing asynchronous hardware access. - -This is used, for example, by drm "prime" multi-GPU support, but is of -course not limited to GPU use cases. - -The three main components of this are: (1) dma-buf, representing a -sg_table and exposed to userspace as a file descriptor to allow passing -between devices, (2) fence, which provides a mechanism to signal when -one device as finished access, and (3) reservation, which manages the -shared or exclusive fence(s) associated with the buffer. - -dma-buf -~~~~~~~ - -.. kernel-doc:: drivers/dma-buf/dma-buf.c - :export: - -.. kernel-doc:: include/linux/dma-buf.h - :internal: - -reservation -~~~~~~~~~~~ - -.. kernel-doc:: drivers/dma-buf/reservation.c - :doc: Reservation Object Overview - -.. kernel-doc:: drivers/dma-buf/reservation.c - :export: - -.. kernel-doc:: include/linux/reservation.h - :internal: - -fence -~~~~~ - -.. kernel-doc:: drivers/dma-buf/dma-fence.c - :export: - -.. kernel-doc:: include/linux/dma-fence.h - :internal: - -.. kernel-doc:: drivers/dma-buf/seqno-fence.c - :export: - -.. kernel-doc:: include/linux/seqno-fence.h - :internal: - -.. kernel-doc:: drivers/dma-buf/dma-fence-array.c - :export: - -.. kernel-doc:: include/linux/dma-fence-array.h - :internal: - -.. kernel-doc:: drivers/dma-buf/reservation.c - :export: - -.. kernel-doc:: include/linux/reservation.h - :internal: - -.. kernel-doc:: drivers/dma-buf/sync_file.c - :export: - -.. kernel-doc:: include/linux/sync_file.h - :internal: - Device Drivers DMA Management -----------------------------