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Commit 868c97a8 authored by Daniel Vetter's avatar Daniel Vetter Committed by Jonathan Corbet
Browse files

dma-buf: Extract dma-buf.rst



Just prep work to polish and consolidate all the dma-buf related
documenation.

Unfortunately I didn't discover a way to both integrate this new file
into the overall toc while keeping it at the current place. Work
around that by moving it into the overall driver-api/index.rst.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 9e22ff43
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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:
+1 −0
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@@ -16,6 +16,7 @@ available subsections can be seen below.

   basics
   infrastructure
   dma-buf
   device_link
   message-based
   sound
+0 −70
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@@ -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
-----------------------------