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+==================================
+Buffer Sharing and Synchronization
+==================================
+
+
+Introduction
+------------
+
+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:
+
+* dma-buf_: represents an sg_table, and is exposed to userspace as a file
+  descriptor to allow passing between devices,
+
+* fence_: which provides a mechanism to signal when one device has finished
+  access, and
+ 
+* reservation_: manages the shared or exclusive fence(s) associated with the
+  buffer.
+
+.. _dma-buf:
+
+dma-buf
+~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/dma-buf.c
+   :export:
+
+.. kernel-doc:: include/linux/dma-buf.h
+   :internal:
+
+.. _fence:
+
+fence
+~~~~~
+
+.. kernel-doc:: drivers/dma-buf/fence.c
+   :export:
+
+.. kernel-doc:: include/linux/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/sync_file.c
+   :export:
+
+.. kernel-doc:: include/linux/sync_file.h
+   :internal:
+
+.. _reservation:
+
+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:
+