Merge tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull CPU hotplug notifiers registration fixes from Rafael Wysocki:
 "The purpose of this single series of commits from Srivatsa S Bhat
  (with a small piece from Gautham R Shenoy) touching multiple
  subsystems that use CPU hotplug notifiers is to provide a way to
  register them that will not lead to deadlocks with CPU online/offline
  operations as described in the changelog of commit 93ae4f978ca7f ("CPU
  hotplug: Provide lockless versions of callback registration
  functions").

  The first three commits in the series introduce the API and document
  it and the rest simply goes through the users of CPU hotplug notifiers
  and converts them to using the new method"

* tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  net/iucv/iucv.c: Fix CPU hotplug callback registration
  net/core/flow.c: Fix CPU hotplug callback registration
  mm, zswap: Fix CPU hotplug callback registration
  mm, vmstat: Fix CPU hotplug callback registration
  profile: Fix CPU hotplug callback registration
  trace, ring-buffer: Fix CPU hotplug callback registration
  xen, balloon: Fix CPU hotplug callback registration
  hwmon, via-cputemp: Fix CPU hotplug callback registration
  hwmon, coretemp: Fix CPU hotplug callback registration
  thermal, x86-pkg-temp: Fix CPU hotplug callback registration
  octeon, watchdog: Fix CPU hotplug callback registration
  oprofile, nmi-timer: Fix CPU hotplug callback registration
  intel-idle: Fix CPU hotplug callback registration
  clocksource, dummy-timer: Fix CPU hotplug callback registration
  drivers/base/topology.c: Fix CPU hotplug callback registration
  acpi-cpufreq: Fix CPU hotplug callback registration
  zsmalloc: Fix CPU hotplug callback registration
  scsi, fcoe: Fix CPU hotplug callback registration
  scsi, bnx2fc: Fix CPU hotplug callback registration
  scsi, bnx2i: Fix CPU hotplug callback registration
  ...

26 files changed, 158 insertions, 70 deletions

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 9da35c6d3411..4d963fb66e3f 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -1073,6 +1073,8 @@ static int __init arch_hw_breakpoint_init(void)
 	core_num_brps = get_num_brps();
 	core_num_wrps = get_num_wrps();
 
+	cpu_notifier_register_begin();
+
 	/*
 	 * We need to tread carefully here because DBGSWENABLE may be
 	 * driven low on this core and there isn't an architected way to
@@ -1089,6 +1091,7 @@ static int __init arch_hw_breakpoint_init(void)
 	if (!cpumask_empty(&debug_err_mask)) {
 		core_num_brps = 0;
 		core_num_wrps = 0;
+		cpu_notifier_register_done();
 		return 0;
 	}
 
@@ -1108,7 +1111,10 @@ static int __init arch_hw_breakpoint_init(void)
 			TRAP_HWBKPT, "breakpoint debug exception");
 
 	/* Register hotplug and PM notifiers. */
-	register_cpu_notifier(&dbg_reset_nb);
+	__register_cpu_notifier(&dbg_reset_nb);
+
+	cpu_notifier_register_done();
+
 	pm_init();
 	return 0;
 }
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bd18bb8b2770..f0e50a0f3a65 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -1051,21 +1051,26 @@ int kvm_arch_init(void *opaque)
 		}
 	}
 
+	cpu_notifier_register_begin();
+
 	err = init_hyp_mode();
 	if (err)
 		goto out_err;
 
-	err = register_cpu_notifier(&hyp_init_cpu_nb);
+	err = __register_cpu_notifier(&hyp_init_cpu_nb);
 	if (err) {
 		kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);
 		goto out_err;
 	}
 
+	cpu_notifier_register_done();
+
 	hyp_cpu_pm_init();
 
 	kvm_coproc_table_init();
 	return 0;
 out_err:
+	cpu_notifier_register_done();
 	return err;
 }
 
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 14ba23c61153..ed3955a95747 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -154,13 +154,17 @@ static struct notifier_block os_lock_nb = {
 
 static int debug_monitors_init(void)
 {
+	cpu_notifier_register_begin();
+
 	/* Clear the OS lock. */
 	on_each_cpu(clear_os_lock, NULL, 1);
 	isb();
 	local_dbg_enable();
 
 	/* Register hotplug handler. */
-	register_cpu_notifier(&os_lock_nb);
+	__register_cpu_notifier(&os_lock_nb);
+
+	cpu_notifier_register_done();
 	return 0;
 }
 postcore_initcall(debug_monitors_init);
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index f17f581116fc..bee789757806 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -913,6 +913,8 @@ static int __init arch_hw_breakpoint_init(void)
 	pr_info("found %d breakpoint and %d watchpoint registers.\n",
 		core_num_brps, core_num_wrps);
 
+	cpu_notifier_register_begin();
+
 	/*
 	 * Reset the breakpoint resources. We assume that a halting
 	 * debugger will leave the world in a nice state for us.
@@ -927,7 +929,10 @@ static int __init arch_hw_breakpoint_init(void)
 			      TRAP_HWBKPT, "hw-watchpoint handler");
 
 	/* Register hotplug notifier. */
-	register_cpu_notifier(&hw_breakpoint_reset_nb);
+	__register_cpu_notifier(&hw_breakpoint_reset_nb);
+
+	cpu_notifier_register_done();
+
 	/* Register cpu_suspend hw breakpoint restore hook */
 	cpu_suspend_set_dbg_restorer(hw_breakpoint_reset);
 
diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c
index f59c0b844e88..0c161ed6d18e 100644
--- a/arch/ia64/kernel/err_inject.c
+++ b/arch/ia64/kernel/err_inject.c
@@ -269,12 +269,17 @@ err_inject_init(void)
 #ifdef ERR_INJ_DEBUG
 	printk(KERN_INFO "Enter error injection driver.\n");
 #endif
+
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(i) {
 		err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,
 				(void *)(long)i);
 	}
 
-	register_hotcpu_notifier(&err_inject_cpu_notifier);
+	__register_hotcpu_notifier(&err_inject_cpu_notifier);
+
+	cpu_notifier_register_done();
 
 	return 0;
 }
@@ -288,11 +293,17 @@ err_inject_exit(void)
 #ifdef ERR_INJ_DEBUG
 	printk(KERN_INFO "Exit error injection driver.\n");
 #endif
+
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(i) {
 		sys_dev = get_cpu_device(i);
 		sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
 	}
-	unregister_hotcpu_notifier(&err_inject_cpu_notifier);
+
+	__unregister_hotcpu_notifier(&err_inject_cpu_notifier);
+
+	cpu_notifier_register_done();
 }
 
 module_init(err_inject_init);
diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c
index ab333284f4b2..c39c3cd3ac34 100644
--- a/arch/ia64/kernel/palinfo.c
+++ b/arch/ia64/kernel/palinfo.c
@@ -996,13 +996,17 @@ palinfo_init(void)
 	if (!palinfo_dir)
 		return -ENOMEM;
 
+	cpu_notifier_register_begin();
+
 	/* Create palinfo dirs in /proc for all online cpus */
 	for_each_online_cpu(i) {
 		create_palinfo_proc_entries(i);
 	}
 
 	/* Register for future delivery via notify registration */
-	register_hotcpu_notifier(&palinfo_cpu_notifier);
+	__register_hotcpu_notifier(&palinfo_cpu_notifier);
+
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c
index 960a396f5929..ee9719eebb1e 100644
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -635,6 +635,8 @@ salinfo_init(void)
 					   (void *)salinfo_entries[i].feature);
 	}
 
+	cpu_notifier_register_begin();
+
 	for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) {
 		data = salinfo_data + i;
 		data->type = i;
@@ -669,7 +671,9 @@ salinfo_init(void)
 	salinfo_timer.function = &salinfo_timeout;
 	add_timer(&salinfo_timer);
 
-	register_hotcpu_notifier(&salinfo_cpu_notifier);
+	__register_hotcpu_notifier(&salinfo_cpu_notifier);
+
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index ca69a5a96dcc..f295f9abba4b 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -454,12 +454,16 @@ static int __init cache_sysfs_init(void)
 {
 	int i;
 
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(i) {
 		struct device *sys_dev = get_cpu_device((unsigned int)i);
 		cache_add_dev(sys_dev);
 	}
 
-	register_hotcpu_notifier(&cache_cpu_notifier);
+	__register_hotcpu_notifier(&cache_cpu_notifier);
+
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 97e1dc917683..d90d4b7810d6 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -975,7 +975,8 @@ static int __init topology_init(void)
 	int cpu;
 
 	register_nodes();
-	register_cpu_notifier(&sysfs_cpu_nb);
+
+	cpu_notifier_register_begin();
 
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -999,6 +1000,11 @@ static int __init topology_init(void)
 		if (cpu_online(cpu))
 			register_cpu_online(cpu);
 	}
+
+	__register_cpu_notifier(&sysfs_cpu_nb);
+
+	cpu_notifier_register_done();
+
 #ifdef CONFIG_PPC64
 	sysfs_create_dscr_default();
 #endif /* CONFIG_PPC64 */
diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c
index 3a414c0f93ed..c0b03c28d157 100644
--- a/arch/s390/kernel/cache.c
+++ b/arch/s390/kernel/cache.c
@@ -378,9 +378,12 @@ static int __init cache_init(void)
 	if (!test_facility(34))
 		return 0;
 	cache_build_info();
+
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu)
 		cache_add_cpu(cpu);
-	hotcpu_notifier(cache_hotplug, 0);
+	__hotcpu_notifier(cache_hotplug, 0);
+	cpu_notifier_register_done();
 	return 0;
 }
 device_initcall(cache_init);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 8827883310dd..5a640b395bd4 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1057,19 +1057,24 @@ static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
 
 static int __init s390_smp_init(void)
 {
-	int cpu, rc;
+	int cpu, rc = 0;
 
-	hotcpu_notifier(smp_cpu_notify, 0);
 #ifdef CONFIG_HOTPLUG_CPU
 	rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
 	if (rc)
 		return rc;
 #endif
+	cpu_notifier_register_begin();
 	for_each_present_cpu(cpu) {
 		rc = smp_add_present_cpu(cpu);
 		if (rc)
-			return rc;
+			goto out;
 	}
-	return 0;
+
+	__hotcpu_notifier(smp_cpu_notify, 0);
+
+out:
+	cpu_notifier_register_done();
+	return rc;
 }
 subsys_initcall(s390_smp_init);
diff --git a/arch/sparc/kernel/sysfs.c b/arch/sparc/kernel/sysfs.c
index c21c673e5f7c..a364000ca1aa 100644
--- a/arch/sparc/kernel/sysfs.c
+++ b/arch/sparc/kernel/sysfs.c
@@ -300,7 +300,7 @@ static int __init topology_init(void)
 
 	check_mmu_stats();
 
-	register_cpu_notifier(&sysfs_cpu_nb);
+	cpu_notifier_register_begin();
 
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -310,6 +310,10 @@ static int __init topology_init(void)
 			register_cpu_online(cpu);
 	}
 
+	__register_cpu_notifier(&sysfs_cpu_nb);
+
+	cpu_notifier_register_done();
+
 	return 0;
 }
 
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index 0641113e2965..a952e9c85b6f 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -1225,21 +1225,24 @@ static struct notifier_block cacheinfo_cpu_notifier = {
 
 static int __init cache_sysfs_init(void)
 {
-	int i;
+	int i, err = 0;
 
 	if (num_cache_leaves == 0)
 		return 0;
 
+	cpu_notifier_register_begin();
 	for_each_online_cpu(i) {
-		int err;
 		struct device *dev = get_cpu_device(i);
 
 		err = cache_add_dev(dev);
 		if (err)
-			return err;
+			goto out;
 	}
-	register_hotcpu_notifier(&cacheinfo_cpu_notifier);
-	return 0;
+	__register_hotcpu_notifier(&cacheinfo_cpu_notifier);
+
+out:
+	cpu_notifier_register_done();
+	return err;
 }
 
 device_initcall(cache_sysfs_init);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 4d5419b249da..9b7734b1f975 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2434,14 +2434,18 @@ static __init int mcheck_init_device(void)
 	if (err)
 		return err;
 
+	cpu_notifier_register_begin();
 	for_each_online_cpu(i) {
 		err = mce_device_create(i);
-		if (err)
+		if (err) {
+			cpu_notifier_register_done();
 			return err;
+		}
 	}
 
 	register_syscore_ops(&mce_syscore_ops);
-	register_hotcpu_notifier(&mce_cpu_notifier);
+	__register_hotcpu_notifier(&mce_cpu_notifier);
+	cpu_notifier_register_done();
 
 	/* register character device /dev/mcelog */
 	misc_register(&mce_chrdev_device);
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index 3eec7de76efb..d921b7ee6595 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -271,9 +271,6 @@ static void thermal_throttle_remove_dev(struct device *dev)
 	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
 }
 
-/* Mutex protecting device creation against CPU hotplug: */
-static DEFINE_MUTEX(therm_cpu_lock);
-
 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
 static int
 thermal_throttle_cpu_callback(struct notifier_block *nfb,
@@ -289,18 +286,14 @@ thermal_throttle_cpu_callback(struct notifier_block *nfb,
 	switch (action) {
 	case CPU_UP_PREPARE:
 	case CPU_UP_PREPARE_FROZEN:
-		mutex_lock(&therm_cpu_lock);
 		err = thermal_throttle_add_dev(dev, cpu);
-		mutex_unlock(&therm_cpu_lock);
 		WARN_ON(err);
 		break;
 	case CPU_UP_CANCELED:
 	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
-		mutex_lock(&therm_cpu_lock);
 		thermal_throttle_remove_dev(dev);
-		mutex_unlock(&therm_cpu_lock);
 		break;
 	}
 	return notifier_from_errno(err);
@@ -319,19 +312,16 @@ static __init int thermal_throttle_init_device(void)
 	if (!atomic_read(&therm_throt_en))
 		return 0;
 
-	register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
+	cpu_notifier_register_begin();
 
-#ifdef CONFIG_HOTPLUG_CPU
-	mutex_lock(&therm_cpu_lock);
-#endif
 	/* connect live CPUs to sysfs */
 	for_each_online_cpu(cpu) {
 		err = thermal_throttle_add_dev(get_cpu_device(cpu), cpu);
 		WARN_ON(err);
 	}
-#ifdef CONFIG_HOTPLUG_CPU
-	mutex_unlock(&therm_cpu_lock);
-#endif
+
+	__register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index 4b8e4d3cd6ea..4c36bbe3173a 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -926,13 +926,13 @@ static __init int amd_ibs_init(void)
 		goto out;
 
 	perf_ibs_pm_init();
-	get_online_cpus();
+	cpu_notifier_register_begin();
 	ibs_caps = caps;
 	/* make ibs_caps visible to other cpus: */
 	smp_mb();
-	perf_cpu_notifier(perf_ibs_cpu_notifier);
 	smp_call_function(setup_APIC_ibs, NULL, 1);
-	put_online_cpus();
+	__perf_cpu_notifier(perf_ibs_cpu_notifier);
+	cpu_notifier_register_done();
 
 	ret = perf_event_ibs_init();
 out:
diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
index 754291adec33..3bbdf4cd38b9 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
@@ -531,15 +531,16 @@ static int __init amd_uncore_init(void)
 	if (ret)
 		return -ENODEV;
 
-	get_online_cpus();
+	cpu_notifier_register_begin();
+
 	/* init cpus already online before registering for hotplug notifier */
 	for_each_online_cpu(cpu) {
 		amd_uncore_cpu_up_prepare(cpu);
 		smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
 	}
 
-	register_cpu_notifier(&amd_uncore_cpu_notifier_block);
-	put_online_cpus();
+	__register_cpu_notifier(&amd_uncore_cpu_notifier_block);
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
index 5ad35ad94d0f..059218ed5208 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
@@ -646,19 +646,20 @@ static int __init rapl_pmu_init(void)
 		/* unsupported */
 		return 0;
 	}
-	get_online_cpus();
+
+	cpu_notifier_register_begin();
 
 	for_each_online_cpu(cpu) {
 		rapl_cpu_prepare(cpu);
 		rapl_cpu_init(cpu);
 	}
 
-	perf_cpu_notifier(rapl_cpu_notifier);
+	__perf_cpu_notifier(rapl_cpu_notifier);
 
 	ret = perf_pmu_register(&rapl_pmu_class, "power", -1);
 	if (WARN_ON(ret)) {
 		pr_info("RAPL PMU detected, registration failed (%d), RAPL PMU disabled\n", ret);
-		put_online_cpus();
+		cpu_notifier_register_done();
 		return -1;
 	}
 
@@ -672,7 +673,7 @@ static int __init rapl_pmu_init(void)
 		hweight32(rapl_cntr_mask),
 		ktime_to_ms(pmu->timer_interval));
 
-	put_online_cpus();
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index bd2253d40cff..65bbbea38b9c 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -4244,7 +4244,7 @@ static void __init uncore_cpumask_init(void)
 	if (!cpumask_empty(&uncore_cpu_mask))
 		return;
 
-	get_online_cpus();
+	cpu_notifier_register_begin();
 
 	for_each_online_cpu(cpu) {
 		int i, phys_id = topology_physical_package_id(cpu);
@@ -4263,9 +4263,9 @@ static void __init uncore_cpumask_init(void)
 	}
 	on_each_cpu(uncore_cpu_setup, NULL, 1);
 
-	register_cpu_notifier(&uncore_cpu_nb);
+	__register_cpu_notifier(&uncore_cpu_nb);
 
-	put_online_cpus();
+	cpu_notifier_register_done();
 }
 
 
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 7d9481c743f8..3225ae6c5180 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -198,14 +198,15 @@ static int __init cpuid_init(void)
 		goto out_chrdev;
 	}
 	cpuid_class->devnode = cpuid_devnode;
-	get_online_cpus();
+
+	cpu_notifier_register_begin();
 	for_each_online_cpu(i) {
 		err = cpuid_device_create(i);
 		if (err != 0)
 			goto out_class;
 	}
-	register_hotcpu_notifier(&cpuid_class_cpu_notifier);
-	put_online_cpus();
+	__register_hotcpu_notifier(&cpuid_class_cpu_notifier);
+	cpu_notifier_register_done();
 
 	err = 0;
 	goto out;
@@ -215,7 +216,7 @@ out_class:
 	for_each_online_cpu(i) {
 		cpuid_device_destroy(i);
 	}
-	put_online_cpus();
+	cpu_notifier_register_done();
 	class_destroy(cpuid_class);
 out_chrdev:
 	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
@@ -227,13 +228,13 @@ static void __exit cpuid_exit(void)
 {
 	int cpu = 0;
 
-	get_online_cpus();
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu)
 		cpuid_device_destroy(cpu);
 	class_destroy(cpuid_class);
 	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
-	unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);
-	put_online_cpus();
+	__unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);
+	cpu_notifier_register_done();
 }
 
 module_init(cpuid_init);
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 93eed15a8fd4..8d80ae011603 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -941,12 +941,14 @@ static __init int hpet_late_init(void)
 	if (boot_cpu_has(X86_FEATURE_ARAT))
 		return 0;
 
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu) {
 		hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
 	}
 
 	/* This notifier should be called after workqueue is ready */
-	hotcpu_notifier(hpet_cpuhp_notify, -20);
+	__hotcpu_notifier(hpet_cpuhp_notify, -20);
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 05266b5aae22..c9603ac80de5 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -259,14 +259,15 @@ static int __init msr_init(void)
 		goto out_chrdev;
 	}
 	msr_class->devnode = msr_devnode;
-	get_online_cpus();
+
+	cpu_notifier_register_begin();
 	for_each_online_cpu(i) {
 		err = msr_device_create(i);
 		if (err != 0)
 			goto out_class;
 	}
-	register_hotcpu_notifier(&msr_class_cpu_notifier);
-	put_online_cpus();
+	__register_hotcpu_notifier(&msr_class_cpu_notifier);
+	cpu_notifier_register_done();
 
 	err = 0;
 	goto out;
@@ -275,7 +276,7 @@ out_class:
 	i = 0;
 	for_each_online_cpu(i)
 		msr_device_destroy(i);
-	put_online_cpus();
+	cpu_notifier_register_done();
 	class_destroy(msr_class);
 out_chrdev:
 	__unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
@@ -286,13 +287,14 @@ out:
 static void __exit msr_exit(void)
 {
 	int cpu = 0;
-	get_online_cpus();
+
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu)
 		msr_device_destroy(cpu);
 	class_destroy(msr_class);
 	__unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
-	unregister_hotcpu_notifier(&msr_class_cpu_notifier);
-	put_online_cpus();
+	__unregister_hotcpu_notifier(&msr_class_cpu_notifier);
+	cpu_notifier_register_done();
 }
 
 module_init(msr_init);
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 9ea287666c65..8b3b3eb3cead 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -348,9 +348,13 @@ static int __init vsyscall_init(void)
 {
 	BUG_ON(VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE));
 
+	cpu_notifier_register_begin();
+
 	on_each_cpu(cpu_vsyscall_init, NULL, 1);
 	/* notifier priority > KVM */
-	hotcpu_notifier(cpu_vsyscall_notifier, 30);
+	__hotcpu_notifier(cpu_vsyscall_notifier, 30);
+
+	cpu_notifier_register_done();
 
 	return 0;
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d1c55f8722c6..9d1b5cd4d34c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5422,7 +5422,8 @@ static void kvm_timer_init(void)
 	int cpu;
 
 	max_tsc_khz = tsc_khz;
-	register_hotcpu_notifier(&kvmclock_cpu_notifier_block);
+
+	cpu_notifier_register_begin();
 	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
 #ifdef CONFIG_CPU_FREQ
 		struct cpufreq_policy policy;
@@ -5439,6 +5440,10 @@ static void kvm_timer_init(void)
 	pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
 	for_each_online_cpu(cpu)
 		smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
+
+	__register_hotcpu_notifier(&kvmclock_cpu_notifier_block);
+	cpu_notifier_register_done();
+
 }
 
 static DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 6890d8498e0b..379e8bd0deea 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -494,14 +494,19 @@ static int nmi_setup(void)
 	if (err)
 		goto fail;
 
+	cpu_notifier_register_begin();
+
+	/* Use get/put_online_cpus() to protect 'nmi_enabled' */
 	get_online_cpus();
-	register_cpu_notifier(&oprofile_cpu_nb);
 	nmi_enabled = 1;
 	/* make nmi_enabled visible to the nmi handler: */
 	smp_mb();
 	on_each_cpu(nmi_cpu_setup, NULL, 1);
+	__register_cpu_notifier(&oprofile_cpu_nb);
 	put_online_cpus();
 
+	cpu_notifier_register_done();
+
 	return 0;
 fail:
 	free_msrs();
@@ -512,12 +517,18 @@ static void nmi_shutdown(void)
 {
 	struct op_msrs *msrs;
 
+	cpu_notifier_register_begin();
+
+	/* Use get/put_online_cpus() to protect 'nmi_enabled' & 'ctr_running' */
 	get_online_cpus();
-	unregister_cpu_notifier(&oprofile_cpu_nb);
 	on_each_cpu(nmi_cpu_shutdown, NULL, 1);
 	nmi_enabled = 0;
 	ctr_running = 0;
+	__unregister_cpu_notifier(&oprofile_cpu_nb);
 	put_online_cpus();
+
+	cpu_notifier_register_done();
+
 	/* make variables visible to the nmi handler: */
 	smp_mb();
 	unregister_nmi_handler(NMI_LOCAL, "oprofile");
diff --git a/arch/x86/pci/amd_bus.c b/arch/x86/pci/amd_bus.c
index a313a7fb6b86..e88f4c53d7f6 100644
--- a/arch/x86/pci/amd_bus.c
+++ b/arch/x86/pci/amd_bus.c
@@ -370,10 +370,13 @@ static int __init pci_io_ecs_init(void)
 	if (early_pci_allowed())
 		pci_enable_pci_io_ecs();
 
-	register_cpu_notifier(&amd_cpu_notifier);
+	cpu_notifier_register_begin();
 	for_each_online_cpu(cpu)
 		amd_cpu_notify(&amd_cpu_notifier, (unsigned long)CPU_ONLINE,
 			       (void *)(long)cpu);
+	__register_cpu_notifier(&amd_cpu_notifier);
+	cpu_notifier_register_done();
+
 	pci_probe |= PCI_HAS_IO_ECS;
 
 	return 0;