[RFC PATCH 6/7] sparc/dma-mapping: override dma_get_page_shift

From: Nishanth Aravamudan
Date: Fri Oct 23 2015 - 17:01:34 EST


On sparc, the kernel's page size differs from the IOMMU's page size, so
override the generic implementation, which always returns the kernel's
page size, and return IOMMU_PAGE_SHIFT instead.

Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx>

---
I know very little about sparc, so please correct me if this patch is
invalid.

arch/sparc/include/asm/dma-mapping.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/arch/sparc/include/asm/dma-mapping.h b/arch/sparc/include/asm/dma-mapping.h
index a21da59..76ba470 100644
--- a/arch/sparc/include/asm/dma-mapping.h
+++ b/arch/sparc/include/asm/dma-mapping.h
@@ -52,6 +52,14 @@ static inline int dma_set_mask(struct device *dev, u64 mask)
return -EINVAL;
}

+/* for IOMMU_PAGE_SHIFT */
+#include <asm/iommu_common.h>
+#define HAVE_ARCH_DMA_GET_PAGE_SHIFT 1
+static inline unsigned long dma_get_page_shift(struct device *dev)
+{
+ return IOMMU_PAGE_SHIFT;
+}
+
#include <asm-generic/dma-mapping-common.h>

#endif
--
1.9.1

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