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@ebshome.net>
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
 
        __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. */