ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()

Replace the page_to_dma() and dma_to_page() macros with their PFN
equivalents.  This allows us to map parts of memory which do not have
a struct page allocated to them to bus addresses.  This will be used
internally by dma_alloc_coherent()/dma_alloc_writecombine().

Build tested on Versatile, OMAP1, IOP13xx and KS8695.

Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index e4dd064..44e7210 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -311,7 +311,7 @@
 		addr = page_address(page);
 
 	if (addr)
-		*handle = page_to_dma(dev, page);
+		*handle = pfn_to_dma(dev, page_to_pfn(page));
 
 	return addr;
 }
@@ -406,7 +406,7 @@
 	if (!arch_is_coherent())
 		__dma_free_remap(cpu_addr, size);
 
-	__dma_free_buffer(dma_to_page(dev, handle), size);
+	__dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size);
 }
 EXPORT_SYMBOL(dma_free_coherent);