[PATCH] ppc32: fix dma_map_page() to use page_to_bus()

[Eugene Surovegin]

Matt,

the following trivial patch changes dma_map_page() to use 
page_to_bus() instead of open-coding it (incorrectly in some cases).

Signed-off-by: Eugene Surovegin <ebs at ebshome.net>

diff --git a/include/asm-ppc/dma-mapping.h b/include/asm-ppc/dma-mapping.h
--- a/include/asm-ppc/dma-mapping.h
+++ b/include/asm-ppc/dma-mapping.h
@@ -117,7 +117,7 @@ dma_map_page(struct device *dev, struct 
 
 	__dma_sync_page(page, offset, size, direction);
 
-	return (page - mem_map) * PAGE_SIZE + PCI_DRAM_OFFSET + offset;
+	return page_to_bus(page) + offset;
 }
 
 /* We do nothing. */