--- b/arch/x86/include/asm/idle.h
+++ a/arch/x86/include/asm/idle.h
@@ -1,6 +1,13 @@
 #ifndef _ASM_X86_IDLE_H
 #define _ASM_X86_IDLE_H
 
+#define IDLE_START 1
+#define IDLE_END 2
+
+struct notifier_block;
+void idle_notifier_register(struct notifier_block *n);
+void idle_notifier_unregister(struct notifier_block *n);
+
 #ifdef CONFIG_X86_64
 void enter_idle(void);
 void exit_idle(void);
--- b/arch/x86/kernel/process.c
+++ a/arch/x86/kernel/process.c
@@ -68,6 +68,19 @@
 
 #ifdef CONFIG_X86_64
 static DEFINE_PER_CPU(unsigned char, is_idle);
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+	atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+	atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
 #endif
 
 /*
@@ -384,14 +397,14 @@
 void enter_idle(void)
 {
 	this_cpu_write(is_idle, 1);
+	atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
-	idle_notifier_call_chain(IDLE_START);
 }
 
 static void __exit_idle(void)
 {
 	if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
 		return;
+	atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
-	idle_notifier_call_chain(IDLE_END);
 }
 
 /* Called from interrupts to signify idle end */
--- b/include/linux/cpu.h
+++ a/include/linux/cpu.h
@@ -276,11 +276,4 @@
 static inline void cpu_smt_check_topology(void) { }
 #endif
 
-#define IDLE_START 1
-#define IDLE_END 2
-
-void idle_notifier_register(struct notifier_block *n);
-void idle_notifier_unregister(struct notifier_block *n);
-void idle_notifier_call_chain(unsigned long val);
-
 #endif /* _LINUX_CPU_H_ */
--- b/kernel/cpu.c
+++ a/kernel/cpu.c
@@ -2206,23 +2206,3 @@
 #endif
 	this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);
 }
-
-static ATOMIC_NOTIFIER_HEAD(idle_notifier);
-
-void idle_notifier_register(struct notifier_block *n)
-{
-	atomic_notifier_chain_register(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_register);
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
-	atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_unregister);
-
-void idle_notifier_call_chain(unsigned long val)
-{
-	atomic_notifier_call_chain(&idle_notifier, val, NULL);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_call_chain);