diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 80c0acfb847211af69e9356677f45f8ea1c4c240..6ef9433e1c7001ff0d00799379de7e71ef1a0113 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -3,8 +3,6 @@
 
 struct task_struct;
 
-int smpboot_prepare(unsigned int cpu);
-
 #ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
 struct task_struct *idle_thread_get(unsigned int cpu);
 void idle_thread_set_boot_cpu(void);