1 files changed, 27 insertions, 10 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 2dc21cbeb304..101a2d4636be 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -13,16 +13,28 @@ enum dma_data_direction {
         DMA_NONE = 3,
 };
 
-#define DMA_64BIT_MASK  0xffffffffffffffffULL
-#define DMA_48BIT_MASK  0x0000ffffffffffffULL
-#define DMA_40BIT_MASK  0x000000ffffffffffULL
-#define DMA_39BIT_MASK  0x0000007fffffffffULL
-#define DMA_32BIT_MASK  0x00000000ffffffffULL
-#define DMA_31BIT_MASK  0x000000007fffffffULL
-#define DMA_30BIT_MASK  0x000000003fffffffULL
-#define DMA_29BIT_MASK  0x000000001fffffffULL
-#define DMA_28BIT_MASK  0x000000000fffffffULL
-#define DMA_24BIT_MASK  0x0000000000ffffffULL
+#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
+
+/*
+ * NOTE: do not use the below macros in new code and do not add new definitions
+ * here.
+ *
+ * Instead, just open-code DMA_BIT_MASK(n) within your driver
+ */
+#define DMA_64BIT_MASK  DMA_BIT_MASK(64)
+#define DMA_48BIT_MASK  DMA_BIT_MASK(48)
+#define DMA_47BIT_MASK  DMA_BIT_MASK(47)
+#define DMA_40BIT_MASK  DMA_BIT_MASK(40)
+#define DMA_39BIT_MASK  DMA_BIT_MASK(39)
+#define DMA_35BIT_MASK  DMA_BIT_MASK(35)
+#define DMA_32BIT_MASK  DMA_BIT_MASK(32)
+#define DMA_31BIT_MASK  DMA_BIT_MASK(31)
+#define DMA_30BIT_MASK  DMA_BIT_MASK(30)
+#define DMA_29BIT_MASK  DMA_BIT_MASK(29)
+#define DMA_28BIT_MASK  DMA_BIT_MASK(28)
+#define DMA_24BIT_MASK  DMA_BIT_MASK(24)
+
+#define DMA_MASK_NONE   0x0ULL
 
 static inline int valid_dma_direction(int dma_direction)
 {
@@ -31,6 +43,11 @@ 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