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, 1 insertions, 0 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 07f5d353b54..0df5f6f75ed 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -19,6 +19,7 @@ config IA64
 	select HAVE_OPROFILE
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
+	select HAVE_DMA_ATTRS
 	select HAVE_KVM
 	default y
 	help