dma-mapping: add dma_{map,unmap}_resource

Map/Unmap a device MMIO resource from a physical address. If no dma_map_ops
method is available the operation is a no-op.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 673b7be..6e00c7f 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -264,6 +264,42 @@
 	debug_dma_unmap_page(dev, addr, size, dir, false);
 }
 
+static inline dma_addr_t dma_map_resource(struct device *dev,
+					  phys_addr_t phys_addr,
+					  size_t size,
+					  enum dma_data_direction dir,
+					  unsigned long attrs)
+{
+	struct dma_map_ops *ops = get_dma_ops(dev);
+	unsigned long pfn = __phys_to_pfn(phys_addr);
+	dma_addr_t addr;
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	/* Don't allow RAM to be mapped */
+	BUG_ON(pfn_valid(pfn));
+
+	addr = phys_addr;
+	if (ops->map_resource)
+		addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+	debug_dma_map_resource(dev, phys_addr, size, dir, addr);
+
+	return addr;
+}
+
+static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
+				      size_t size, enum dma_data_direction dir,
+				      unsigned long attrs)
+{
+	struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->unmap_resource)
+		ops->unmap_resource(dev, addr, size, dir, attrs);
+	debug_dma_unmap_resource(dev, addr, size, dir);
+}
+
 static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
 					   size_t size,
 					   enum dma_data_direction dir)