Index: arch/amd64/include/mm/as.h
===================================================================
--- arch/amd64/include/mm/as.h	(revision 4512d7e1af168899c6317084648322e9f8381026)
+++ arch/amd64/include/mm/as.h	(revision 4e147a6b5728fbdb666c31b993900fd3d6681518)
@@ -43,3 +43,5 @@
 #define as_install_arch(as)
 
+extern void as_arch_init(void);
+
 #endif