#define page_to_pfn(page) discontigmem_page_to_pfn(page)
#define pfn_to_page(pfn) discontigmem_pfn_to_page(pfn)
#define pfn_valid(pfn) discontigmem_pfn_valid(pfn)
-#else
+#endif
+#ifdef CONFIG_FLATMEM
#define pfn_to_page(pfn) (mem_map + (pfn))
#define page_to_pfn(page) ((unsigned long)((page) - mem_map))
#define pfn_valid(pfn) ((pfn) < max_mapnr)