Provide an implementation for dma_{alloc,free,mmap}_writecombine() when
the architecture supports DMA attributes.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>