fix build bug in "x86: add PCI extended config space access for AMD Barcelona"
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 99221f9..656b40a 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -4,6 +4,7 @@
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/apic.h>
+#include <asm/mmconfig.h>
 
 #include <mach_apic.h>
 #include "../setup.h"