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>

arch/x86/kernel/pci-base_32.c

@@ -40,6 +40,7 @@ static const struct dma_mapping_ops pci32_dma_ops = {
 	.sync_single_range_for_cpu = NULL,
 	.sync_single_range_for_device = NULL,
 	.sync_sg_for_cpu = NULL,
+	.sync_sg_for_device = NULL,
 };
 
 const struct dma_mapping_ops *dma_ops = &pci32_dma_ops;

include/asm-x86/dma-mapping.h

@@ -148,4 +148,15 @@ dma_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
 		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

include/asm-x86/dma-mapping_32.h

@@ -32,13 +32,6 @@ dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
 	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)
 {

include/asm-x86/dma-mapping_64.h

@@ -27,18 +27,6 @@ extern void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 	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 */