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authorSeung-Woo Kim <sw0312.kim@samsung.com>2013-02-06 13:21:14 +0900
committerMarek Szyprowski <m.szyprowski@samsung.com>2013-02-25 15:30:43 +0100
commit60460abffc71523d65774f43ce1252972eeb0629 (patch)
tree07c55cb6ad9d203c95a2fae8a2de4e0ea25e9a3e /arch/arm/mm
parentf8669bef11fadfe811a5d7d59cb327499edac088 (diff)
downloadop-kernel-dev-60460abffc71523d65774f43ce1252972eeb0629.zip
op-kernel-dev-60460abffc71523d65774f43ce1252972eeb0629.tar.gz
ARM: dma-mapping: Add maximum alignment order for dma iommu buffers
Alignment order for a dma iommu buffer is set by buffer size. For large buffer, it is a waste of iommu address space. So configurable parameter to limit maximum alignment order can reduce the waste. Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com> Signed-off-by: Kyungmin.park <kyungmin.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/dma-mapping.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 2163af4..6e25115 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1029,6 +1029,9 @@ static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
unsigned int count, start;
unsigned long flags;
+ if (order > CONFIG_ARM_DMA_IOMMU_ALIGNMENT)
+ order = CONFIG_ARM_DMA_IOMMU_ALIGNMENT;
+
count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
(1 << mapping->order) - 1) >> mapping->order;
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