dma: add dma_*map*_attrs() interfaces

Introduce new interfaces, dma_*map*_attrs(), for passing architecture-specific
attributes when memory is mapped and unmapped for DMA.  Give the interfaces
default implementations which ignore attributes.  Also introduce the
dma_{set|get}_attr() interfaces for setting and retrieving individual
attributes.  Define one attribute, DMA_ATTR_WRITE_BARRIER, in anticipation of
its use by ia64/sn.  Select whether architectures implement arch-specific
versions of the dma_*map*_attrs() interfaces via HAVE_DMA_ATTRS in Kconfig.

[markn@au1.ibm.com: dma_{set,get}_attr() have to be static inline]
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 332030709623..952e0f857ac9 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -146,4 +146,21 @@ static inline void dmam_release_declared_memory(struct device *dev)
 }
 #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
 
+#ifndef CONFIG_HAVE_DMA_ATTRS
+struct dma_attrs;
+
+#define dma_map_single_attrs(dev, cpu_addr, size, dir, attrs) \
+        dma_map_single(dev, cpu_addr, size, dir)
+
+#define dma_unmap_single_attrs(dev, dma_addr, size, dir, attrs) \
+        dma_unmap_single(dev, dma_addr, size, dir)
+
+#define dma_map_sg_attrs(dev, sgl, nents, dir, attrs) \
+        dma_map_sg(dev, sgl, nents, dir)
+
+#define dma_unmap_sg_attrs(dev, sgl, nents, dir, attrs) \
+        dma_unmap_sg(dev, sgl, nents, dir)
+
+#endif /* CONFIG_HAVE_DMA_ATTRS */
+
 #endif