1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 2dc21cbeb304..0ebfafbd338c 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -24,6 +24,8 @@ enum dma_data_direction {
 #define DMA_28BIT_MASK  0x000000000fffffffULL
 #define DMA_24BIT_MASK  0x0000000000ffffffULL
 
+#define DMA_MASK_NONE   0x0ULL
+
 static inline int valid_dma_direction(int dma_direction)
 {
         return ((dma_direction == DMA_BIDIRECTIONAL) ||
@@ -31,6 +33,11 @@ static inline int valid_dma_direction(int dma_direction)
                 (dma_direction == DMA_FROM_DEVICE));
 }
 
+static inline int is_device_dma_capable(struct device *dev)
+{
+        return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
+}
+
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
 #else