FRV: Provide dma_map_page() for NOMMU and fix comments

Provide dma_map_page() for the NOMMU-mode FRV arch.

Also do some fixing on the comments attached to the various DMA functions for
both MMU and NOMMU mode FRV code.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/frv/mb93090-mb00/pci-dma-nommu.c

@@ -111,7 +111,7 @@ EXPORT_SYMBOL(dma_free_coherent);
  * The 32-bit bus address to use is returned.
  *
  * Once the device is given the dma address, the device owns this memory
- * until either pci_unmap_single or pci_dma_sync_single is performed.
+ * until either dma_unmap_single or pci_dma_sync_single is performed.
  */
 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
 			  enum dma_data_direction direction)
@@ -129,7 +129,7 @@ EXPORT_SYMBOL(dma_map_single);
 /*
  * Map a set of buffers described by scatterlist in streaming
  * mode for DMA.  This is the scather-gather version of the
- * above pci_map_single interface.  Here the scatter gather list
+ * above dma_map_single interface.  Here the scatter gather list
  * elements are each tagged with the appropriate dma address
  * and length.  They are obtained via sg_dma_{address,length}(SG).
  *
@@ -139,7 +139,7 @@ EXPORT_SYMBOL(dma_map_single);
  *       The routine returns the number of addr/length pairs actually
  *       used, at most nents.
  *
- * Device ownership issues as mentioned above for pci_map_single are
+ * Device ownership issues as mentioned above for dma_map_single are
  * the same here.
  */
 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
@@ -158,3 +158,20 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 }
 
 EXPORT_SYMBOL(dma_map_sg);
+
+/*
+ * Map a single page of the indicated size for DMA in streaming mode.
+ * The 32-bit bus address to use is returned.
+ *
+ * Device ownership issues as mentioned above for dma_map_single are
+ * the same here.
+ */
+dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
+			size_t size, enum dma_data_direction direction)
+{
+	BUG_ON(direction == DMA_NONE);
+	flush_dcache_page(page);
+	return (dma_addr_t) page_to_phys(page) + offset;
+}
+
+EXPORT_SYMBOL(dma_map_page);

arch/frv/mb93090-mb00/pci-dma.c

@@ -61,7 +61,7 @@ EXPORT_SYMBOL(dma_map_single);
 /*
  * Map a set of buffers described by scatterlist in streaming
  * mode for DMA.  This is the scather-gather version of the
- * above pci_map_single interface.  Here the scatter gather list
+ * above dma_map_single interface.  Here the scatter gather list
  * elements are each tagged with the appropriate dma address
  * and length.  They are obtained via sg_dma_{address,length}(SG).
  *
@@ -71,7 +71,7 @@ EXPORT_SYMBOL(dma_map_single);
  *       The routine returns the number of addr/length pairs actually
  *       used, at most nents.
  *
- * Device ownership issues as mentioned above for pci_map_single are
+ * Device ownership issues as mentioned above for dma_map_single are
  * the same here.
  */
 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
@@ -105,6 +105,13 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 
 EXPORT_SYMBOL(dma_map_sg);
 
+/*
+ * Map a single page of the indicated size for DMA in streaming mode.
+ * The 32-bit bus address to use is returned.
+ *
+ * Device ownership issues as mentioned above for dma_map_single are
+ * the same here.
+ */
 dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 			size_t size, enum dma_data_direction direction)
 {