diff --git a/include/linux/mm.h b/include/linux/mm.h
index cf3d0d673f6be67fd978ef8c0d3f277a81c132b7..bd58ee01855534049fc1c2ef3a43de5e32cc4f46 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -221,6 +221,9 @@ int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
 /* to align the pointer to the (next) page boundary */
 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
 
+/* to align the pointer to the (prev) page boundary */
+#define PAGE_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PAGE_SIZE)
+
 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
 #define PAGE_ALIGNED(addr)	IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)