[ARM] dma-mapping: provide sync_range APIs

Convert the existing dma_sync_single_for_* APIs to the new range based
APIs, and make the dma_sync_single_for_* API a superset of it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/dmabounce.c

@@ -321,9 +321,8 @@ unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 	}
 }
 
-static inline void
-sync_single(struct device *dev, dma_addr_t dma_addr, size_t size,
-		enum dma_data_direction dir)
+static int sync_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+			enum dma_data_direction dir)
 {
 	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
 	struct safe_buffer *buf = NULL;
@@ -383,8 +382,9 @@ sync_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 		 * No need to sync the safe buffer - it was allocated
 		 * via the coherent allocators.
 		 */
+		return 0;
 	} else {
-		dma_cache_maint(dma_to_virt(dev, dma_addr), size, dir);
+		return 1;
 	}
 }
 
@@ -474,25 +474,29 @@ dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 	}
 }
 
-void
-dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr, size_t size,
-				enum dma_data_direction dir)
+void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_addr,
+				   unsigned long offset, size_t size,
+				   enum dma_data_direction dir)
 {
-	dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
-		__func__, (void *) dma_addr, size, dir);
+	dev_dbg(dev, "%s(dma=%#x,off=%#lx,size=%zx,dir=%x)\n",
+		__func__, dma_addr, offset, size, dir);
 
-	sync_single(dev, dma_addr, size, dir);
+	if (sync_single(dev, dma_addr, offset + size, dir))
+		dma_cache_maint(dma_to_virt(dev, dma_addr) + offset, size, dir);
 }
+EXPORT_SYMBOL(dma_sync_single_range_for_cpu);
 
-void
-dma_sync_single_for_device(struct device *dev, dma_addr_t dma_addr, size_t size,
-				enum dma_data_direction dir)
+void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_addr,
+				      unsigned long offset, size_t size,
+				      enum dma_data_direction dir)
 {
-	dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
-		__func__, (void *) dma_addr, size, dir);
+	dev_dbg(dev, "%s(dma=%#x,off=%#lx,size=%zx,dir=%x)\n",
+		__func__, dma_addr, offset, size, dir);
 
-	sync_single(dev, dma_addr, size, dir);
+	if (sync_single(dev, dma_addr, offset + size, dir))
+		dma_cache_maint(dma_to_virt(dev, dma_addr) + offset, size, dir);
 }
+EXPORT_SYMBOL(dma_sync_single_range_for_device);
 
 void
 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
@@ -644,8 +648,6 @@ EXPORT_SYMBOL(dma_map_single);
 EXPORT_SYMBOL(dma_unmap_single);
 EXPORT_SYMBOL(dma_map_sg);
 EXPORT_SYMBOL(dma_unmap_sg);
-EXPORT_SYMBOL(dma_sync_single_for_cpu);
-EXPORT_SYMBOL(dma_sync_single_for_device);
 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 EXPORT_SYMBOL(dma_sync_sg_for_device);
 EXPORT_SYMBOL(dmabounce_register_dev);

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

@@ -351,11 +351,12 @@ extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_da
 
 
 /**
- * dma_sync_single_for_cpu
+ * dma_sync_single_range_for_cpu
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  * @handle: DMA address of buffer
- * @size: size of buffer to map
- * @dir: DMA transfer direction
+ * @offset: offset of region to start sync
+ * @size: size of region to sync
+ * @dir: DMA transfer direction (same as passed to dma_map_single)
  *
  * Make physical memory consistent for a single streaming mode DMA
  * translation after a transfer.
@@ -369,25 +370,41 @@ extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_da
  */
 #ifndef CONFIG_DMABOUNCE
 static inline void
-dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
-			enum dma_data_direction dir)
+dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t handle,
+			      unsigned long offset, size_t size,
+			      enum dma_data_direction dir)
 {
 	if (!arch_is_coherent())
-		dma_cache_maint(dma_to_virt(dev, handle), size, dir);
+		dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
 }
 
 static inline void
-dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
-			   enum dma_data_direction dir)
+dma_sync_single_range_for_device(struct device *dev, dma_addr_t handle,
+				 unsigned long offset, size_t size,
+				 enum dma_data_direction dir)
 {
 	if (!arch_is_coherent())
-		dma_cache_maint(dma_to_virt(dev, handle), size, dir);
+		dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
 }
 #else
-extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
-extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
+extern void dma_sync_single_range_for_cpu(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction);
+extern void dma_sync_single_range_for_device(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction);
 #endif
 
+static inline void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
+			enum dma_data_direction dir)
+{
+	dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
+}
+
+static inline void
+dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
+			   enum dma_data_direction dir)
+{
+	dma_sync_single_range_for_device(dev, handle, 0, size, dir);
+}
+
 
 /**
  * dma_sync_sg_for_cpu