arm64: make default ARM64_DMA_IOMMU_ALIGNMENT as 9

To realize section mapping of 2MB in arm64 iommu mappings,
set ARM64_DMA_IOMMU_ALIGNMENT to 9 so that 2MB aligned
virtual address can be allocated based on size.

2MB section mapping in iommu page tables would ensure less
pressure on TLBs.

Change-Id: Id22e935e113bee2a4ae7aeab15bcf17b7b6f3c78
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index cbfb3f4..9ce839a 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -210,7 +210,7 @@ if ARM64_DMA_USE_IOMMU
 config ARM64_DMA_IOMMU_ALIGNMENT
        int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
        range 4 9
-       default 8
+       default 9
        help
          DMA mapping framework by default aligns all buffers to the smallest
          PAGE_SIZE order which is greater than or equal to the requested buffer