Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull DMA mapping branch from Marek Szyprowski:
 "Short summary for the whole series:

  A few limitations have been identified in the current dma-mapping
  design and its implementations for various architectures.  There exist
  more than one function for allocating and freeing the buffers:
  currently these 3 are used dma_{alloc, free}_coherent,
  dma_{alloc,free}_writecombine, dma_{alloc,free}_noncoherent.

  For most of the systems these calls are almost equivalent and can be
  interchanged.  For others, especially the truly non-coherent ones
  (like ARM), the difference can be easily noticed in overall driver
  performance.  Sadly not all architectures provide implementations for
  all of them, so the drivers might need to be adapted and cannot be
  easily shared between different architectures.  The provided patches
  unify all these functions and hide the differences under the already
  existing dma attributes concept.  The thread with more references is
  available here:

    http://www.spinics.net/lists/linux-sh/msg09777.html

  These patches are also a prerequisite for unifying DMA-mapping
  implementation on ARM architecture with the common one provided by
  dma_map_ops structure and extending it with IOMMU support.  More
  information is available in the following thread:

    http://thread.gmane.org/gmane.linux.kernel.cross-arch/12819

  More works on dma-mapping framework are planned, especially in the
  area of buffer sharing and managing the shared mappings (together with
  the recently introduced dma_buf interface: commit d15bd7ee445d
  "dma-buf: Introduce dma buffer sharing mechanism").

  The patches in the current set introduce a new alloc/free methods
  (with support for memory attributes) in dma_map_ops structure, which
  will later replace dma_alloc_coherent and dma_alloc_writecombine
  functions."

People finally started piping up with support for merging this, so I'm
merging it as the last of the pending stuff from the merge window.
Looks like pohmelfs is going to wait for 3.5 and more external support
for merging.

* 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  common: DMA-mapping: add NON-CONSISTENT attribute
  common: DMA-mapping: add WRITE_COMBINE attribute
  common: dma-mapping: introduce mmap method
  common: dma-mapping: remove old alloc_coherent and free_coherent methods
  Hexagon: adapt for dma_map_ops changes
  Unicore32: adapt for dma_map_ops changes
  Microblaze: adapt for dma_map_ops changes
  SH: adapt for dma_map_ops changes
  Alpha: adapt for dma_map_ops changes
  SPARC: adapt for dma_map_ops changes
  PowerPC: adapt for dma_map_ops changes
  MIPS: adapt for dma_map_ops changes
  X86 & IA64: adapt for dma_map_ops changes
  common: dma-mapping: introduce generic alloc() and free() methods

1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index b768cc0e402..5c72eed8956 100644
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -31,3 +31,21 @@ may be weakly ordered, that is that reads and writes may pass each other.
 Since it is optional for platforms to implement DMA_ATTR_WEAK_ORDERING,
 those that do not will simply ignore the attribute and exhibit default
 behavior.
+
+DMA_ATTR_WRITE_COMBINE
+----------------------
+
+DMA_ATTR_WRITE_COMBINE specifies that writes to the mapping may be
+buffered to improve performance.
+
+Since it is optional for platforms to implement DMA_ATTR_WRITE_COMBINE,
+those that do not will simply ignore the attribute and exhibit default
+behavior.
+
+DMA_ATTR_NON_CONSISTENT
+-----------------------
+
+DMA_ATTR_NON_CONSISTENT lets the platform to choose to return either
+consistent or non-consistent memory as it sees fit.  By using this API,
+you are guaranteeing to the platform that you have all the correct and
+necessary sync points for this memory in the driver.