[PATCH] Revert "arm64: Make default dma_ops to be noncoherent"

[Ming Lei]

This reverts commit c7a4a7658d689f664050c45493d79adf053f226e.

Conflicts:
	arch/arm64/mm/dma-mapping.c

On ARM64, Utopic kernel ships APM's PCI host controller driver
which isn't upstreamed yet, and APM's ARM64 Soc is a coherent
platform. On the other side, ARM64 maintainer[1] said the
commit c7a4a7658 can be reverted safely if booting with ACPI
which can be supported by APM's own kernel release too.

So please revert the commit c7a4a7658 to avoid breaking
PCI function on APM ARM64.

BugLink: https://bugs.launchpad.net/bugs/1386490

[1] http://marc.info/?l=linux-arm-kernel&m=141708838404470&w=2

Cc: Dann Frazier <dann.frazier at canonical.com>
Signed-off-by: Ming Lei <ming.lei at canonical.com>
---
 arch/arm64/mm/dma-mapping.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 4164c5a..acc807a 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -342,7 +342,7 @@ static int __init swiotlb_late_init(void)
 	bus_register_notifier(&platform_bus_type, &platform_bus_nb);
 	bus_register_notifier(&amba_bustype, &amba_bus_nb);
 
-	dma_ops = &noncoherent_swiotlb_dma_ops;
+	dma_ops = &coherent_swiotlb_dma_ops;
 
 	return swiotlb_late_init_with_default_size(swiotlb_size);
 }
-- 
1.9.1