diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 81887120395c..95978ad7fcdd 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -256,7 +256,6 @@ enum cpuhp_state {
 };
 
 void cpu_startup_entry(enum cpuhp_state state);
-void cpu_idle(void);
 
 void cpu_idle_poll_ctrl(bool enable);
 
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 633f5edd7470..34347f26be9b 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -13,8 +13,6 @@
 #include <linux/init.h>
 #include <linux/llist.h>
 
-extern void cpu_idle(void);
-
 typedef void (*smp_call_func_t)(void *info);
 struct call_single_data {
 	struct llist_node llist;