Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug updates from Thomas Gleixner:
 "Yet another batch of cpu hotplug core updates and conversions:

   - Provide core infrastructure for multi instance drivers so the
     drivers do not have to keep custom lists.

   - Convert custom lists to the new infrastructure. The block-mq custom
     list conversion comes through the block tree and makes the diffstat
     tip over to more lines removed than added.

   - Handle unbalanced hotplug enable/disable calls more gracefully.

   - Remove the obsolete CPU_STARTING/DYING notifier support.

   - Convert another batch of notifier users.

   The relayfs changes which conflicted with the conversion have been
   shipped to me by Andrew.

   The remaining lot is targeted for 4.10 so that we finally can remove
   the rest of the notifiers"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  cpufreq: Fix up conversion to hotplug state machine
  blk/mq: Reserve hotplug states for block multiqueue
  x86/apic/uv: Convert to hotplug state machine
  s390/mm/pfault: Convert to hotplug state machine
  mips/loongson/smp: Convert to hotplug state machine
  mips/octeon/smp: Convert to hotplug state machine
  fault-injection/cpu: Convert to hotplug state machine
  padata: Convert to hotplug state machine
  cpufreq: Convert to hotplug state machine
  ACPI/processor: Convert to hotplug state machine
  virtio scsi: Convert to hotplug state machine
  oprofile/timer: Convert to hotplug state machine
  block/softirq: Convert to hotplug state machine
  lib/irq_poll: Convert to hotplug state machine
  x86/microcode: Convert to hotplug state machine
  sh/SH-X3 SMP: Convert to hotplug state machine
  ia64/mca: Convert to hotplug state machine
  ARM/OMAP/wakeupgen: Convert to hotplug state machine
  ARM/shmobile: Convert to hotplug state machine
  arm64/FP/SIMD: Convert to hotplug state machine
  ...

4 files changed, 39 insertions, 98 deletions

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index f034c84f74c3..aeef53ce93e1 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -924,7 +924,7 @@ static void uv_heartbeat(unsigned long ignored)
 	mod_timer(timer, jiffies + SCIR_CPU_HB_INTERVAL);
 }
 
-static void uv_heartbeat_enable(int cpu)
+static int uv_heartbeat_enable(unsigned int cpu)
 {
 	while (!uv_cpu_scir_info(cpu)->enabled) {
 		struct timer_list *timer = &uv_cpu_scir_info(cpu)->timer;
@@ -938,43 +938,24 @@ static void uv_heartbeat_enable(int cpu)
 		/* also ensure that boot cpu is enabled */
 		cpu = 0;
 	}
+	return 0;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-static void uv_heartbeat_disable(int cpu)
+static int uv_heartbeat_disable(unsigned int cpu)
 {
 	if (uv_cpu_scir_info(cpu)->enabled) {
 		uv_cpu_scir_info(cpu)->enabled = 0;
 		del_timer(&uv_cpu_scir_info(cpu)->timer);
 	}
 	uv_set_cpu_scir_bits(cpu, 0xff);
-}
-
-/*
- * cpu hotplug notifier
- */
-static int uv_scir_cpu_notify(struct notifier_block *self, unsigned long action,
-			      void *hcpu)
-{
-	long cpu = (long)hcpu;
-
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_DOWN_FAILED:
-	case CPU_ONLINE:
-		uv_heartbeat_enable(cpu);
-		break;
-	case CPU_DOWN_PREPARE:
-		uv_heartbeat_disable(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
+	return 0;
 }
 
 static __init void uv_scir_register_cpu_notifier(void)
 {
-	hotcpu_notifier(uv_scir_cpu_notify, 0);
+	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/x2apic-uvx:online",
+				  uv_heartbeat_enable, uv_heartbeat_disable);
 }
 
 #else /* !CONFIG_HOTPLUG_CPU */
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index df04b2d033f6..5ce5155f0695 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -558,55 +558,36 @@ static struct syscore_ops mc_syscore_ops = {
 	.resume			= mc_bp_resume,
 };
 
-static int
-mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
+static int mc_cpu_online(unsigned int cpu)
 {
-	unsigned int cpu = (unsigned long)hcpu;
 	struct device *dev;
 
 	dev = get_cpu_device(cpu);
+	microcode_update_cpu(cpu);
+	pr_debug("CPU%d added\n", cpu);
 
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_ONLINE:
-		microcode_update_cpu(cpu);
-		pr_debug("CPU%d added\n", cpu);
-		/*
-		 * "break" is missing on purpose here because we want to fall
-		 * through in order to create the sysfs group.
-		 */
-
-	case CPU_DOWN_FAILED:
-		if (sysfs_create_group(&dev->kobj, &mc_attr_group))
-			pr_err("Failed to create group for CPU%d\n", cpu);
-		break;
+	if (sysfs_create_group(&dev->kobj, &mc_attr_group))
+		pr_err("Failed to create group for CPU%d\n", cpu);
+	return 0;
+}
 
-	case CPU_DOWN_PREPARE:
-		/* Suspend is in progress, only remove the interface */
-		sysfs_remove_group(&dev->kobj, &mc_attr_group);
-		pr_debug("CPU%d removed\n", cpu);
-		break;
+static int mc_cpu_down_prep(unsigned int cpu)
+{
+	struct device *dev;
 
+	dev = get_cpu_device(cpu);
+	/* Suspend is in progress, only remove the interface */
+	sysfs_remove_group(&dev->kobj, &mc_attr_group);
+	pr_debug("CPU%d removed\n", cpu);
 	/*
-	 * case CPU_DEAD:
-	 *
 	 * When a CPU goes offline, don't free up or invalidate the copy of
 	 * the microcode in kernel memory, so that we can reuse it when the
 	 * CPU comes back online without unnecessarily requesting the userspace
 	 * for it again.
 	 */
-	}
-
-	/* The CPU refused to come up during a system resume */
-	if (action == CPU_UP_CANCELED_FROZEN)
-		microcode_fini_cpu(cpu);
-
-	return NOTIFY_OK;
+	return 0;
 }
 
-static struct notifier_block mc_cpu_notifier = {
-	.notifier_call	= mc_cpu_callback,
-};
-
 static struct attribute *cpu_root_microcode_attrs[] = {
 	&dev_attr_reload.attr,
 	NULL
@@ -665,7 +646,8 @@ int __init microcode_init(void)
 		goto out_ucode_group;
 
 	register_syscore_ops(&mc_syscore_ops);
-	register_hotcpu_notifier(&mc_cpu_notifier);
+	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
+				  mc_cpu_online, mc_cpu_down_prep);
 
 	pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 		" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 865058d087ac..edbbfc854e39 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -423,12 +423,7 @@ static void __init kvm_smp_prepare_boot_cpu(void)
 	kvm_spinlock_init();
 }
 
-static void kvm_guest_cpu_online(void *dummy)
-{
-	kvm_guest_cpu_init();
-}
-
-static void kvm_guest_cpu_offline(void *dummy)
+static void kvm_guest_cpu_offline(void)
 {
 	kvm_disable_steal_time();
 	if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
@@ -437,29 +432,21 @@ static void kvm_guest_cpu_offline(void *dummy)
 	apf_task_wake_all();
 }
 
-static int kvm_cpu_notify(struct notifier_block *self, unsigned long action,
-			  void *hcpu)
+static int kvm_cpu_online(unsigned int cpu)
 {
-	int cpu = (unsigned long)hcpu;
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_DOWN_FAILED:
-	case CPU_ONLINE_FROZEN:
-		smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0);
-		break;
-	case CPU_DOWN_PREPARE:
-	case CPU_DOWN_PREPARE_FROZEN:
-		smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
+	local_irq_disable();
+	kvm_guest_cpu_init();
+	local_irq_enable();
+	return 0;
 }
 
-static struct notifier_block kvm_cpu_notifier = {
-        .notifier_call  = kvm_cpu_notify,
-};
+static int kvm_cpu_down_prepare(unsigned int cpu)
+{
+	local_irq_disable();
+	kvm_guest_cpu_offline();
+	local_irq_enable();
+	return 0;
+}
 #endif
 
 static void __init kvm_apf_trap_init(void)
@@ -494,7 +481,9 @@ void __init kvm_guest_init(void)
 
 #ifdef CONFIG_SMP
 	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
-	register_cpu_notifier(&kvm_cpu_notifier);
+	if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online",
+				      kvm_cpu_online, kvm_cpu_down_prepare) < 0)
+		pr_err("kvm_guest: Failed to install cpu hotplug callbacks\n");
 #else
 	kvm_guest_cpu_init();
 #endif
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7249dcf2cbcb..42a93621f5b0 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1115,17 +1115,8 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
 
 	common_cpu_up(cpu, tidle);
 
-	/*
-	 * We have to walk the irq descriptors to setup the vector
-	 * space for the cpu which comes online.  Prevent irq
-	 * alloc/free across the bringup.
-	 */
-	irq_lock_sparse();
-
 	err = do_boot_cpu(apicid, cpu, tidle);
-
 	if (err) {
-		irq_unlock_sparse();
 		pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu);
 		return -EIO;
 	}
@@ -1143,8 +1134,6 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
 		touch_nmi_watchdog();
 	}
 
-	irq_unlock_sparse();
-
 	return 0;
 }