arm64: Add support for DMA_ATTR_STRONGLY_ORDERED

Strongly ordered memory prevents speculative accesses among
other features. Add support for this attribute in arm64.

Change-Id: If26459f63edfea3108ad7426e29f98c23b1a07ef
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Conflicts:
	arch/arm64/mm/dma-mapping.c
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 7963aa4b5d2869b70dfd9a2f3d0ef501a033480b..54eba2c4a878d43d6d2b94893b77d26edc1b71c3 100644 (file)
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -34,6 +34,8 @@ static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
 {
        if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
                return pgprot_writecombine(prot);
+       else if (dma_get_attr(DMA_ATTR_STRONGLY_ORDERED, attrs))
+               prot = pgprot_noncached(prot);
        return prot;
 }