iommu/amd: Introduce dir2prot() helper

This function converts dma_data_direction to
iommu-protection flags. This will be needed on multiple
places in the code, so this will save some code.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index c0b2f4fc6bfc..281cacbd5816 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2252,6 +2252,17 @@ static void update_domain(struct protection_domain *domain)
         domain->updated = false;
 }
 
+static int dir2prot(enum dma_data_direction direction)
+{
+        if (direction == DMA_TO_DEVICE)
+                return IOMMU_PROT_IR;
+        else if (direction == DMA_FROM_DEVICE)
+                return IOMMU_PROT_IW;
+        else if (direction == DMA_BIDIRECTIONAL)
+                return IOMMU_PROT_IW | IOMMU_PROT_IR;
+        else
+                return 0;
+}
 /*
  * This function contains common code for mapping of a physically
  * contiguous memory region into DMA address space. It is used by all
@@ -2262,7 +2273,7 @@ static dma_addr_t __map_single(struct device *dev,
                                struct dma_ops_domain *dma_dom,
                                phys_addr_t paddr,
                                size_t size,
-                               int direction,
+                               enum dma_data_direction direction,
                                u64 dma_mask)
 {
         dma_addr_t offset = paddr & ~PAGE_MASK;
@@ -2278,12 +2289,7 @@ static dma_addr_t __map_single(struct device *dev,
         if (address == DMA_ERROR_CODE)
                 goto out;
 
-        if (direction == DMA_TO_DEVICE)
-                prot = IOMMU_PROT_IR;
-        else if (direction == DMA_FROM_DEVICE)
-                prot = IOMMU_PROT_IW;
-        else if (direction == DMA_BIDIRECTIONAL)
-                prot = IOMMU_PROT_IW | IOMMU_PROT_IR;
+        prot = dir2prot(direction);
 
         start = address;
         for (i = 0; i < pages; ++i) {