x86: move dma_sync_sg_for_device to common header

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>
diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h
index 1a301d7..53a404b 100644
--- a/include/asm-x86/dma-mapping.h
+++ b/include/asm-x86/dma-mapping.h
@@ -148,4 +148,15 @@
 		dma_ops->sync_sg_for_cpu(hwdev, sg, nelems, direction);
 	flush_write_buffers();
 }
+
+static inline void
+dma_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+		       int nelems, int direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+	if (dma_ops->sync_sg_for_device)
+		dma_ops->sync_sg_for_device(hwdev, sg, nelems, direction);
+
+	flush_write_buffers();
+}
 #endif
diff --git a/include/asm-x86/dma-mapping_32.h b/include/asm-x86/dma-mapping_32.h
index e7c82e3..eff42f4 100644
--- a/include/asm-x86/dma-mapping_32.h
+++ b/include/asm-x86/dma-mapping_32.h
@@ -32,13 +32,6 @@
 	BUG_ON(!valid_dma_direction(direction));
 }
 
-static inline void
-dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
-		    enum dma_data_direction direction)
-{
-	flush_write_buffers();
-}
-
 static inline int
 dma_mapping_error(dma_addr_t dma_addr)
 {
diff --git a/include/asm-x86/dma-mapping_64.h b/include/asm-x86/dma-mapping_64.h
index 804b154..707dbbe 100644
--- a/include/asm-x86/dma-mapping_64.h
+++ b/include/asm-x86/dma-mapping_64.h
@@ -27,18 +27,6 @@
 	dma_map_single((dev), page_address(page)+(offset), (size), (dir))
 
 #define dma_unmap_page dma_unmap_single
-static inline void
-dma_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
-		       int nelems, int direction)
-{
-	BUG_ON(!valid_dma_direction(direction));
-	if (dma_ops->sync_sg_for_device) {
-		dma_ops->sync_sg_for_device(hwdev, sg, nelems, direction);
-	}
-
-	flush_write_buffers();
-}
-
 extern int dma_supported(struct device *hwdev, u64 mask);
 
 /* same for gart, swiotlb, and nommu */