diff --git a/[refs] b/[refs]
index a8c946528d92..225529ff9e85 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e92b4fdacc6a7d8cc7895b81347671d5fcd6c5e1
+refs/heads/master: 636dc67cbf8c481a996faf6c23f0532d0f02ebad
diff --git a/trunk/include/linux/dma-mapping.h b/trunk/include/linux/dma-mapping.h
index 952e0f857ac9..6ed50c1642f1 100644
--- a/trunk/include/linux/dma-mapping.h
+++ b/trunk/include/linux/dma-mapping.h
@@ -48,6 +48,11 @@ static inline int is_device_dma_capable(struct device *dev)
 	return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
 }
 
+static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr, size_t size)
+{
+	return addr + size <= mask;
+}
+
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
 #else