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

Pull smp hotplug updates from Thomas Gleixner:
 "This is the final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

4 files changed, 72 insertions, 199 deletions

diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c
index 5ed0ea92c5bf..85bba43e7d5d 100644
--- a/arch/ia64/kernel/err_inject.c
+++ b/arch/ia64/kernel/err_inject.c
@@ -224,85 +224,45 @@ static struct attribute_group err_inject_attr_group = {
 	.name = "err_inject"
 };
 /* Add/Remove err_inject interface for CPU device */
-static int err_inject_add_dev(struct device *sys_dev)
+static int err_inject_add_dev(unsigned int cpu)
 {
+	struct device *sys_dev = get_cpu_device(cpu);
+
 	return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);
 }
 
-static int err_inject_remove_dev(struct device *sys_dev)
+static int err_inject_remove_dev(unsigned int cpu)
 {
+	struct device *sys_dev = get_cpu_device(cpu);
+
 	sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
 	return 0;
 }
-static int err_inject_cpu_callback(struct notifier_block *nfb,
-		unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-	struct device *sys_dev;
-
-	sys_dev = get_cpu_device(cpu);
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		err_inject_add_dev(sys_dev);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		err_inject_remove_dev(sys_dev);
-		break;
-	}
-
-	return NOTIFY_OK;
-}
 
-static struct notifier_block err_inject_cpu_notifier =
-{
-	.notifier_call = err_inject_cpu_callback,
-};
+static enum cpuhp_state hp_online;
 
-static int __init
-err_inject_init(void)
+static int __init err_inject_init(void)
 {
-	int i;
-
+	int ret;
 #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);
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/err_inj:online",
+				err_inject_add_dev, err_inject_remove_dev);
+	if (ret >= 0) {
+		hp_online = ret;
+		ret = 0;
 	}
-
-	__register_hotcpu_notifier(&err_inject_cpu_notifier);
-
-	cpu_notifier_register_done();
-
-	return 0;
+	return ret;
 }
 
-static void __exit
-err_inject_exit(void)
+static void __exit err_inject_exit(void)
 {
-	int i;
-	struct device *sys_dev;
-
 #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);
-
-	cpu_notifier_register_done();
+	cpuhp_remove_state(hp_online);
 }
 
 module_init(err_inject_init);
diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c
index c39c3cd3ac34..b6e597860888 100644
--- a/arch/ia64/kernel/palinfo.c
+++ b/arch/ia64/kernel/palinfo.c
@@ -932,8 +932,7 @@ static const struct file_operations proc_palinfo_fops = {
 	.release	= single_release,
 };
 
-static void
-create_palinfo_proc_entries(unsigned int cpu)
+static int palinfo_add_proc(unsigned int cpu)
 {
 	pal_func_cpu_u_t f;
 	struct proc_dir_entry *cpu_dir;
@@ -943,7 +942,7 @@ create_palinfo_proc_entries(unsigned int cpu)
 
 	cpu_dir = proc_mkdir(cpustr, palinfo_dir);
 	if (!cpu_dir)
-		return;
+		return -EINVAL;
 
 	f.req_cpu = cpu;
 
@@ -952,42 +951,21 @@ create_palinfo_proc_entries(unsigned int cpu)
 		proc_create_data(palinfo_entries[j].name, 0, cpu_dir,
 				 &proc_palinfo_fops, (void *)f.value);
 	}
+	return 0;
 }
 
-static void
-remove_palinfo_proc_entries(unsigned int hcpu)
+static int palinfo_del_proc(unsigned int hcpu)
 {
 	char cpustr[3+4+1];	/* cpu numbers are up to 4095 on itanic */
+
 	sprintf(cpustr, "cpu%d", hcpu);
 	remove_proc_subtree(cpustr, palinfo_dir);
+	return 0;
 }
 
-static int palinfo_cpu_callback(struct notifier_block *nfb,
-					unsigned long action, void *hcpu)
-{
-	unsigned int hotcpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		create_palinfo_proc_entries(hotcpu);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		remove_palinfo_proc_entries(hotcpu);
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block __refdata palinfo_cpu_notifier =
-{
-	.notifier_call = palinfo_cpu_callback,
-	.priority = 0,
-};
+static enum cpuhp_state hp_online;
 
-static int __init
-palinfo_init(void)
+static int __init palinfo_init(void)
 {
 	int i = 0;
 
@@ -996,25 +974,19 @@ 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);
+	i = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/palinfo:online",
+			      palinfo_add_proc, palinfo_del_proc);
+	if (i < 0) {
+		remove_proc_subtree("pal", NULL);
+		return i;
 	}
-
-	/* Register for future delivery via notify registration */
-	__register_hotcpu_notifier(&palinfo_cpu_notifier);
-
-	cpu_notifier_register_done();
-
+	hp_online = i;
 	return 0;
 }
 
-static void __exit
-palinfo_exit(void)
+static void __exit palinfo_exit(void)
 {
-	unregister_hotcpu_notifier(&palinfo_cpu_notifier);
+	cpuhp_remove_state(hp_online);
 	remove_proc_subtree("pal", NULL);
 }
 
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c
index 5313007d5423..aaf74f36cfa1 100644
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -550,52 +550,40 @@ static const struct file_operations salinfo_data_fops = {
 	.llseek  = default_llseek,
 };
 
-static int
-salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
+static int salinfo_cpu_online(unsigned int cpu)
 {
-	unsigned int i, cpu = (unsigned long)hcpu;
-	unsigned long flags;
+	unsigned int i, end = ARRAY_SIZE(salinfo_data);
 	struct salinfo_data *data;
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		spin_lock_irqsave(&data_saved_lock, flags);
-		for (i = 0, data = salinfo_data;
-		     i < ARRAY_SIZE(salinfo_data);
-		     ++i, ++data) {
-			cpumask_set_cpu(cpu, &data->cpu_event);
-			wake_up_interruptible(&data->read_wait);
-		}
-		spin_unlock_irqrestore(&data_saved_lock, flags);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		spin_lock_irqsave(&data_saved_lock, flags);
-		for (i = 0, data = salinfo_data;
-		     i < ARRAY_SIZE(salinfo_data);
-		     ++i, ++data) {
-			struct salinfo_data_saved *data_saved;
-			int j;
-			for (j = ARRAY_SIZE(data->data_saved) - 1, data_saved = data->data_saved + j;
-			     j >= 0;
-			     --j, --data_saved) {
-				if (data_saved->buffer && data_saved->cpu == cpu) {
-					shift1_data_saved(data, j);
-				}
-			}
-			cpumask_clear_cpu(cpu, &data->cpu_event);
-		}
-		spin_unlock_irqrestore(&data_saved_lock, flags);
-		break;
+
+	spin_lock_irq(&data_saved_lock);
+	for (i = 0, data = salinfo_data; i < end; ++i, ++data) {
+		cpumask_set_cpu(cpu, &data->cpu_event);
+		wake_up_interruptible(&data->read_wait);
 	}
-	return NOTIFY_OK;
+	spin_unlock_irq(&data_saved_lock);
+	return 0;
 }
 
-static struct notifier_block salinfo_cpu_notifier =
+static int salinfo_cpu_pre_down(unsigned int cpu)
 {
-	.notifier_call = salinfo_cpu_callback,
-	.priority = 0,
-};
+	unsigned int i, end = ARRAY_SIZE(salinfo_data);
+	struct salinfo_data *data;
+
+	spin_lock_irq(&data_saved_lock);
+	for (i = 0, data = salinfo_data; i < end; ++i, ++data) {
+		struct salinfo_data_saved *data_saved;
+		int j = ARRAY_SIZE(data->data_saved) - 1;
+
+		for (data_saved = data->data_saved + j; j >= 0;
+		     --j, --data_saved) {
+			if (data_saved->buffer && data_saved->cpu == cpu)
+				shift1_data_saved(data, j);
+		}
+		cpumask_clear_cpu(cpu, &data->cpu_event);
+	}
+	spin_unlock_irq(&data_saved_lock);
+	return 0;
+}
 
 static int __init
 salinfo_init(void)
@@ -604,7 +592,7 @@ salinfo_init(void)
 	struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */
 	struct proc_dir_entry *dir, *entry;
 	struct salinfo_data *data;
-	int i, j;
+	int i;
 
 	salinfo_dir = proc_mkdir("sal", NULL);
 	if (!salinfo_dir)
@@ -617,8 +605,6 @@ 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;
@@ -639,10 +625,6 @@ salinfo_init(void)
 			continue;
 		*sdir++ = entry;
 
-		/* we missed any events before now */
-		for_each_online_cpu(j)
-			cpumask_set_cpu(j, &data->cpu_event);
-
 		*sdir++ = dir;
 	}
 
@@ -653,10 +635,9 @@ salinfo_init(void)
 	salinfo_timer.function = &salinfo_timeout;
 	add_timer(&salinfo_timer);
 
-	__register_hotcpu_notifier(&salinfo_cpu_notifier);
-
-	cpu_notifier_register_done();
-
+	i = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/salinfo:online",
+			      salinfo_cpu_online, salinfo_cpu_pre_down);
+	WARN_ON(i < 0);
 	return 0;
 }
 
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index c01fe8991244..1a68f012a6dc 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -349,9 +349,9 @@ static int cpu_cache_sysfs_init(unsigned int cpu)
 }
 
 /* Add cache interface for CPU device */
-static int cache_add_dev(struct device *sys_dev)
+static int cache_add_dev(unsigned int cpu)
 {
-	unsigned int cpu = sys_dev->id;
+	struct device *sys_dev = get_cpu_device(cpu);
 	unsigned long i, j;
 	struct cache_info *this_object;
 	int retval = 0;
@@ -399,9 +399,8 @@ static int cache_add_dev(struct device *sys_dev)
 }
 
 /* Remove cache interface for CPU device */
-static int cache_remove_dev(struct device *sys_dev)
+static int cache_remove_dev(unsigned int cpu)
 {
-	unsigned int cpu = sys_dev->id;
 	unsigned long i;
 
 	for (i = 0; i < all_cpu_cache_info[cpu].num_cache_leaves; i++)
@@ -419,52 +418,13 @@ static int cache_remove_dev(struct device *sys_dev)
 	return 0;
 }
 
-/*
- * When a cpu is hot-plugged, do a check and initiate
- * cache kobject if necessary
- */
-static int cache_cpu_callback(struct notifier_block *nfb,
-		unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-	struct device *sys_dev;
-
-	sys_dev = get_cpu_device(cpu);
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		cache_add_dev(sys_dev);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		cache_remove_dev(sys_dev);
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block cache_cpu_notifier =
-{
-	.notifier_call = cache_cpu_callback
-};
-
 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);
-
-	cpu_notifier_register_done();
+	int ret;
 
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/topology:online",
+				cache_add_dev, cache_remove_dev);
+	WARN_ON(ret < 0);
 	return 0;
 }
-
 device_initcall(cache_sysfs_init);
-