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
  ...

2 files changed, 64 insertions, 65 deletions

diff --git a/net/core/flow.c b/net/core/flow.c
index 31cfb365e0c6..a0348fde1fdf 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -455,6 +455,8 @@ int flow_cache_init(struct net *net)
 	if (!fc->percpu)
 		return -ENOMEM;
 
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(i) {
 		if (flow_cache_cpu_prepare(fc, i))
 			goto err;
@@ -462,7 +464,9 @@ int flow_cache_init(struct net *net)
 	fc->hotcpu_notifier = (struct notifier_block){
 		.notifier_call = flow_cache_cpu,
 	};
-	register_hotcpu_notifier(&fc->hotcpu_notifier);
+	__register_hotcpu_notifier(&fc->hotcpu_notifier);
+
+	cpu_notifier_register_done();
 
 	setup_timer(&fc->rnd_timer, flow_cache_new_hashrnd,
 		    (unsigned long) fc);
@@ -478,6 +482,8 @@ err:
 		fcp->hash_table = NULL;
 	}
 
+	cpu_notifier_register_done();
+
 	free_percpu(fc->percpu);
 	fc->percpu = NULL;
 
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index cd5b8ec9be04..79a0ce95799f 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -621,6 +621,42 @@ static void iucv_disable(void)
 	put_online_cpus();
 }
 
+static void free_iucv_data(int cpu)
+{
+	kfree(iucv_param_irq[cpu]);
+	iucv_param_irq[cpu] = NULL;
+	kfree(iucv_param[cpu]);
+	iucv_param[cpu] = NULL;
+	kfree(iucv_irq_data[cpu]);
+	iucv_irq_data[cpu] = NULL;
+}
+
+static int alloc_iucv_data(int cpu)
+{
+	/* Note: GFP_DMA used to get memory below 2G */
+	iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
+			     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
+	if (!iucv_irq_data[cpu])
+		goto out_free;
+
+	/* Allocate parameter blocks. */
+	iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
+			  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
+	if (!iucv_param[cpu])
+		goto out_free;
+
+	iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
+			  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
+	if (!iucv_param_irq[cpu])
+		goto out_free;
+
+	return 0;
+
+out_free:
+	free_iucv_data(cpu);
+	return -ENOMEM;
+}
+
 static int iucv_cpu_notify(struct notifier_block *self,
 				     unsigned long action, void *hcpu)
 {
@@ -630,38 +666,14 @@ static int iucv_cpu_notify(struct notifier_block *self,
 	switch (action) {
 	case CPU_UP_PREPARE:
 	case CPU_UP_PREPARE_FROZEN:
-		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
-					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_irq_data[cpu])
-			return notifier_from_errno(-ENOMEM);
-
-		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
-				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_param[cpu]) {
-			kfree(iucv_irq_data[cpu]);
-			iucv_irq_data[cpu] = NULL;
+		if (alloc_iucv_data(cpu))
 			return notifier_from_errno(-ENOMEM);
-		}
-		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
-					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_param_irq[cpu]) {
-			kfree(iucv_param[cpu]);
-			iucv_param[cpu] = NULL;
-			kfree(iucv_irq_data[cpu]);
-			iucv_irq_data[cpu] = NULL;
-			return notifier_from_errno(-ENOMEM);
-		}
 		break;
 	case CPU_UP_CANCELED:
 	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
-		kfree(iucv_param_irq[cpu]);
-		iucv_param_irq[cpu] = NULL;
-		kfree(iucv_param[cpu]);
-		iucv_param[cpu] = NULL;
-		kfree(iucv_irq_data[cpu]);
-		iucv_irq_data[cpu] = NULL;
+		free_iucv_data(cpu);
 		break;
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
@@ -2025,33 +2037,20 @@ static int __init iucv_init(void)
 		goto out_int;
 	}
 
-	for_each_online_cpu(cpu) {
-		/* Note: GFP_DMA used to get memory below 2G */
-		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
-				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_irq_data[cpu]) {
-			rc = -ENOMEM;
-			goto out_free;
-		}
+	cpu_notifier_register_begin();
 
-		/* Allocate parameter blocks. */
-		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
-				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_param[cpu]) {
-			rc = -ENOMEM;
-			goto out_free;
-		}
-		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
-				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
-		if (!iucv_param_irq[cpu]) {
+	for_each_online_cpu(cpu) {
+		if (alloc_iucv_data(cpu)) {
 			rc = -ENOMEM;
 			goto out_free;
 		}
-
 	}
-	rc = register_hotcpu_notifier(&iucv_cpu_notifier);
+	rc = __register_hotcpu_notifier(&iucv_cpu_notifier);
 	if (rc)
 		goto out_free;
+
+	cpu_notifier_register_done();
+
 	rc = register_reboot_notifier(&iucv_reboot_notifier);
 	if (rc)
 		goto out_cpu;
@@ -2069,16 +2068,14 @@ static int __init iucv_init(void)
 out_reboot:
 	unregister_reboot_notifier(&iucv_reboot_notifier);
 out_cpu:
-	unregister_hotcpu_notifier(&iucv_cpu_notifier);
+	cpu_notifier_register_begin();
+	__unregister_hotcpu_notifier(&iucv_cpu_notifier);
 out_free:
-	for_each_possible_cpu(cpu) {
-		kfree(iucv_param_irq[cpu]);
-		iucv_param_irq[cpu] = NULL;
-		kfree(iucv_param[cpu]);
-		iucv_param[cpu] = NULL;
-		kfree(iucv_irq_data[cpu]);
-		iucv_irq_data[cpu] = NULL;
-	}
+	for_each_possible_cpu(cpu)
+		free_iucv_data(cpu);
+
+	cpu_notifier_register_done();
+
 	root_device_unregister(iucv_root);
 out_int:
 	unregister_external_interrupt(0x4000, iucv_external_interrupt);
@@ -2105,15 +2102,11 @@ static void __exit iucv_exit(void)
 		kfree(p);
 	spin_unlock_irq(&iucv_queue_lock);
 	unregister_reboot_notifier(&iucv_reboot_notifier);
-	unregister_hotcpu_notifier(&iucv_cpu_notifier);
-	for_each_possible_cpu(cpu) {
-		kfree(iucv_param_irq[cpu]);
-		iucv_param_irq[cpu] = NULL;
-		kfree(iucv_param[cpu]);
-		iucv_param[cpu] = NULL;
-		kfree(iucv_irq_data[cpu]);
-		iucv_irq_data[cpu] = NULL;
-	}
+	cpu_notifier_register_begin();
+	__unregister_hotcpu_notifier(&iucv_cpu_notifier);
+	for_each_possible_cpu(cpu)
+		free_iucv_data(cpu);
+	cpu_notifier_register_done();
 	root_device_unregister(iucv_root);
 	bus_unregister(&iucv_bus);
 	unregister_external_interrupt(0x4000, iucv_external_interrupt);