Split out dma-buf related parts into their own section, add missing files, and write a bit of overview about how it all fits together.
Signed-off-by: Rob Clark robdclark@gmail.com --- Documentation/DocBook/device-drivers.tmpl | 36 +++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-)
diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl index cdd8b24..9c41af9 100644 --- a/Documentation/DocBook/device-drivers.tmpl +++ b/Documentation/DocBook/device-drivers.tmpl @@ -128,14 +128,42 @@ X!Edrivers/base/interface.c !Edrivers/base/platform.c !Edrivers/base/bus.c </sect1> - <sect1><title>Device Drivers DMA Management</title> + <sect1> + <title>Buffer Sharing and Synchronization</title> + <para> + 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. + </para> + <para> + This is used, for example, by drm "prime" multi-GPU support, but + is of course not limited to GPU use cases. + </para> + <para> + 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. + </para> + <sect2><title>dma-buf</title> !Edrivers/dma-buf/dma-buf.c +!Iinclude/linux/dma-buf.h + </sect2> + <sect2><title>reservation</title> +!Pdrivers/dma-buf/reservation.c Reservation Object Overview +!Edrivers/dma-buf/reservation.c +!Iinclude/linux/reservation.h + </sect2> + <sect2><title>fence</title> !Edrivers/dma-buf/fence.c -!Edrivers/dma-buf/seqno-fence.c !Iinclude/linux/fence.h +!Edrivers/dma-buf/seqno-fence.c !Iinclude/linux/seqno-fence.h -!Edrivers/dma-buf/reservation.c -!Iinclude/linux/reservation.h + </sect2> + </sect1> + <sect1><title>Device Drivers DMA Management</title> !Edrivers/base/dma-coherent.c !Edrivers/base/dma-mapping.c </sect1>