powerpc: merge __dma_set_mask into dma_set_mask

Signed-off-by: Christoph Hellwig <hch@lst.de>

arch/powerpc/include/asm/dma-mapping.h

@@ -112,7 +112,6 @@ static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 #define HAVE_ARCH_DMA_SET_MASK 1
 extern int dma_set_mask(struct device *dev, u64 dma_mask);
 
-extern int __dma_set_mask(struct device *dev, u64 dma_mask);
 extern u64 __dma_get_required_mask(struct device *dev);
 
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)

arch/powerpc/kernel/dma.c

@@ -314,14 +314,6 @@ EXPORT_SYMBOL(dma_set_coherent_mask);
 
 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 
-int __dma_set_mask(struct device *dev, u64 dma_mask)
-{
-	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
-		return -EIO;
-	*dev->dma_mask = dma_mask;
-	return 0;
-}
-
 int dma_set_mask(struct device *dev, u64 dma_mask)
 {
 	if (ppc_md.dma_set_mask)
@@ -334,7 +326,10 @@ int dma_set_mask(struct device *dev, u64 dma_mask)
 			return phb->controller_ops.dma_set_mask(pdev, dma_mask);
 	}
 
-	return __dma_set_mask(dev, dma_mask);
+	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+		return -EIO;
+	*dev->dma_mask = dma_mask;
+	return 0;
 }
 EXPORT_SYMBOL(dma_set_mask);