diff --git a/include/linux/mm.h b/include/linux/mm.h
index ef859426a836..f79d114a20b1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -736,6 +736,12 @@ static inline void set_compound_order(struct page *page, unsigned int order)
 	page[1].compound_order = order;
 }
 
+/* Returns the number of bytes in this potentially compound page. */
+static inline unsigned long page_size(struct page *page)
+{
+	return PAGE_SIZE << compound_order(page);
+}
+
 void free_compound_page(struct page *page);
 
 #ifdef CONFIG_MMU