diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 832888d..4adf71b 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -57,6 +57,7 @@
 
 #ifndef __ASSEMBLY__
 
+#include <linux/compiler.h>
 #include <linux/linkage.h>
 #include <linux/irqflags.h>
 
@@ -104,7 +105,7 @@
 extern void show_pte(struct mm_struct *mm, unsigned long addr);
 extern void __show_regs(struct pt_regs *);
 
-extern int cpu_architecture(void);
+extern int __pure cpu_architecture(void);
 extern void cpu_init(void);
 
 void arm_machine_restart(char mode, const char *cmd);