+
+#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
+struct page;
+/* this is useful when inlined pfn_to_page is too big */
+extern struct page *pfn_to_page(unsigned long pfn);
+extern unsigned long page_to_pfn(struct page *page);
+#else
+#define page_to_pfn __page_to_pfn
+#define pfn_to_page __pfn_to_page