i386 gets an empty function.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
        .map_single = pci32_map_single,
        .unmap_single = NULL,
        .map_sg = pci32_dma_map_sg,
+       .unmap_sg = NULL,
 };
 
 const struct dma_mapping_ops *dma_ops = &pci32_dma_ops;
 
        BUG_ON(!valid_dma_direction(direction));
        return dma_ops->map_sg(hwdev, sg, nents, direction);
 }
+
+static inline void
+dma_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents,
+            int direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+       if (dma_ops->unmap_sg)
+               dma_ops->unmap_sg(hwdev, sg, nents, direction);
+}
 #endif
 
        BUG_ON(!valid_dma_direction(direction));
 }
 
-
-static inline void
-dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
-            enum dma_data_direction direction)
-{
-       BUG_ON(!valid_dma_direction(direction));
-}
-
 static inline void
 dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
                        enum dma_data_direction direction)
 
        flush_write_buffers();
 }
 
-static inline void
-dma_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents,
-            int direction)
-{
-       BUG_ON(!valid_dma_direction(direction));
-       dma_ops->unmap_sg(hwdev, sg, nents, direction);
-}
-
 extern int dma_supported(struct device *hwdev, u64 mask);
 
 /* same for gart, swiotlb, and nommu */