diff --git a/include/linux/mm.h b/include/linux/mm.h
index 526f810..c657ea0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -107,6 +107,7 @@
 #define VM_ALWAYSDUMP	0x04000000	/* Always include in core dumps */
 
 #define VM_CAN_NONLINEAR 0x08000000	/* Has ->fault & does nonlinear pages */
+#define VM_MIXEDMAP	0x10000000	/* Can contain "struct page" and pure PFN pages */
 
 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS