Add suspend-related notifications for CPU hotplug

Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

47 files changed, 152 insertions, 27 deletions

diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index cc60d29b954..b6d24c22274 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -217,14 +217,17 @@ Q: What happens when a CPU is being logically offlined?
 A: The following happen, listed in no particular order :-)
 
 - A notification is sent to in-kernel registered modules by sending an event
-  CPU_DOWN_PREPARE
+  CPU_DOWN_PREPARE or CPU_DOWN_PREPARE_FROZEN, depending on whether or not the
+  CPU is being offlined while tasks are frozen due to a suspend operation in
+  progress
 - All process is migrated away from this outgoing CPU to a new CPU
 - All interrupts targeted to this CPU is migrated to a new CPU
 - timers/bottom half/task lets are also migrated to a new CPU
 - Once all services are migrated, kernel calls an arch specific routine
   __cpu_disable() to perform arch specific cleanup.
 - Once this is successful, an event for successful cleanup is sent by an event
-  CPU_DEAD.
+  CPU_DEAD (or CPU_DEAD_FROZEN if tasks are frozen due to a suspend while the
+  CPU is being offlined).
 
   "It is expected that each service cleans up when the CPU_DOWN_PREPARE
   notifier is called, when CPU_DEAD is called its expected there is nothing
@@ -242,9 +245,11 @@ A: This is what you would need in your kernel code to receive notifications.
 
 		switch (action) {
 		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
 			foobar_online_action(cpu);
 			break;
 		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
 			foobar_dead_action(cpu);
 			break;
 		}
diff --git a/arch/i386/kernel/cpu/intel_cacheinfo.c b/arch/i386/kernel/cpu/intel_cacheinfo.c
index 80b4c5d421b..e5be819492e 100644
--- a/arch/i386/kernel/cpu/intel_cacheinfo.c
+++ b/arch/i386/kernel/cpu/intel_cacheinfo.c
@@ -733,9 +733,11 @@ static int __cpuinit cacheinfo_cpu_callback(struct notifier_block *nfb,
 	sys_dev = get_cpu_sysdev(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;
 	}
diff --git a/arch/i386/kernel/cpu/mcheck/therm_throt.c b/arch/i386/kernel/cpu/mcheck/therm_throt.c
index 065005c3f16..5b0a040213c 100644
--- a/arch/i386/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/i386/kernel/cpu/mcheck/therm_throt.c
@@ -137,10 +137,12 @@ static __cpuinit int thermal_throttle_cpu_callback(struct notifier_block *nfb,
 	mutex_lock(&therm_cpu_lock);
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		err = thermal_throttle_add_dev(sys_dev);
 		WARN_ON(err);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		thermal_throttle_remove_dev(sys_dev);
 		break;
 	}
diff --git a/arch/i386/kernel/cpuid.c b/arch/i386/kernel/cpuid.c
index eeae0d99233..5c2faa10e9f 100644
--- a/arch/i386/kernel/cpuid.c
+++ b/arch/i386/kernel/cpuid.c
@@ -169,9 +169,11 @@ static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long ac
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		cpuid_device_create(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
 		break;
 	}
diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c
index cbe7ec8dbb9..7d934e493e7 100644
--- a/arch/i386/kernel/microcode.c
+++ b/arch/i386/kernel/microcode.c
@@ -775,10 +775,13 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 	sys_dev = get_cpu_sysdev(cpu);
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 	case CPU_DOWN_FAILED:
+	case CPU_DOWN_FAILED_FROZEN:
 		mc_sysdev_add(sys_dev);
 		break;
 	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
 		mc_sysdev_remove(sys_dev);
 		break;
 	}
diff --git a/arch/i386/kernel/msr.c b/arch/i386/kernel/msr.c
index 8cd0a91ce10..0c1069b8d63 100644
--- a/arch/i386/kernel/msr.c
+++ b/arch/i386/kernel/msr.c
@@ -153,9 +153,11 @@ static int msr_class_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		msr_device_create(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));
 		break;
 	}
diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c
index d3e9f33e8bd..6a49600cf33 100644
--- a/arch/ia64/kernel/err_inject.c
+++ b/arch/ia64/kernel/err_inject.c
@@ -236,9 +236,11 @@ static int __cpuinit err_inject_cpu_callback(struct notifier_block *nfb,
 	sys_dev = get_cpu_sysdev(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;
 	}
diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c
index a71df9ae039..85829e27785 100644
--- a/arch/ia64/kernel/palinfo.c
+++ b/arch/ia64/kernel/palinfo.c
@@ -975,9 +975,11 @@ static int palinfo_cpu_callback(struct notifier_block *nfb,
 
 	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;
 	}
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c
index a51f1d0bfb7..89f6b138a62 100644
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -582,6 +582,7 @@ salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu
 	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);
@@ -592,6 +593,7 @@ salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu
 		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);
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 687500ddb4b..94ae3c87d82 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -412,9 +412,11 @@ static int __cpuinit cache_cpu_callback(struct notifier_block *nfb,
 	sys_dev = get_cpu_sysdev(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;
 	}
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index cae39d9dfe4..68991c2d4a1 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -342,10 +342,12 @@ static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		register_cpu_online(cpu);
 		break;
 #ifdef CONFIG_HOTPLUG_CPU
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		unregister_cpu_online(cpu);
 		break;
 #endif
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b3a592b25ab..de45aa82d97 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -252,12 +252,15 @@ static int __cpuinit cpu_numa_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
 		numa_setup_cpu(lcpu);
 		ret = NOTIFY_OK;
 		break;
 #ifdef CONFIG_HOTPLUG_CPU
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 		unmap_cpu_from_node(lcpu);
 		break;
 		ret = NOTIFY_OK;
diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c
index ee89b33145d..81a2b92ab0c 100644
--- a/arch/s390/appldata/appldata_base.c
+++ b/arch/s390/appldata/appldata_base.c
@@ -567,9 +567,11 @@ appldata_cpu_notify(struct notifier_block *self,
 {
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		appldata_online_cpu((long) hcpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		appldata_offline_cpu((long) hcpu);
 		break;
 	default:
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index b7977027a28..09f028a3266 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -789,10 +789,12 @@ static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		if (sysdev_create_file(s, &attr_capability))
 			return NOTIFY_BAD;
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		sysdev_remove_file(s, &attr_capability);
 		break;
 	}
diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c
index 442169640e4..a14375dd542 100644
--- a/arch/x86_64/kernel/mce.c
+++ b/arch/x86_64/kernel/mce.c
@@ -720,9 +720,11 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		mce_create_device(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		mce_remove_device(cpu);
 		break;
 	}
diff --git a/arch/x86_64/kernel/mce_amd.c b/arch/x86_64/kernel/mce_amd.c
index d0bd5d66e10..03356e64f9c 100644
--- a/arch/x86_64/kernel/mce_amd.c
+++ b/arch/x86_64/kernel/mce_amd.c
@@ -654,9 +654,11 @@ static int threshold_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		threshold_create_device(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		threshold_remove_device(cpu);
 		break;
 	default:
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index dc32cef9619..51d4c6fa88c 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -327,7 +327,7 @@ static int __cpuinit
 cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
 {
 	long cpu = (long)arg;
-	if (action == CPU_ONLINE)
+	if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
 		smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 0, 1);
 	return NOTIFY_DONE;
 }
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index df506571ed6..cd54672da99 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3507,7 +3507,7 @@ static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
 	 * If a CPU goes away, splice its entries to the current CPU
 	 * and trigger a run of the softirq
 	 */
-	if (action == CPU_DEAD) {
+	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
 		int cpu = (unsigned long) hcpu;
 
 		local_irq_disable();
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 067a9e8bc37..8d8cdfec652 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -126,10 +126,13 @@ static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
 		rc = topology_add_dev(cpu);
 		break;
 	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		topology_remove_dev(cpu);
 		break;
 	}
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 893dbaf386f..eb37fba9b7e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1685,9 +1685,11 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
 	if (sys_dev) {
 		switch (action) {
 		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
 			cpufreq_add_dev(sys_dev);
 			break;
 		case CPU_DOWN_PREPARE:
+		case CPU_DOWN_PREPARE_FROZEN:
 			if (unlikely(lock_policy_rwsem_write(cpu)))
 				BUG();
 
@@ -1699,6 +1701,7 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
 			__cpufreq_remove_dev(sys_dev);
 			break;
 		case CPU_DOWN_FAILED:
+		case CPU_DOWN_FAILED_FROZEN:
 			cpufreq_add_dev(sys_dev);
 			break;
 		}
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index d1c7cac9316..d2f0cbd8b8f 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -313,9 +313,11 @@ static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		cpufreq_update_policy(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		cpufreq_stats_free_table(cpu);
 		break;
 	}
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 03b1f650d1c..75e3911810a 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -309,9 +309,11 @@ static int coretemp_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		coretemp_device_add(cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		coretemp_device_remove(cpu);
 		break;
 	}
diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c
index f284be1c916..82dda2faf4d 100644
--- a/drivers/infiniband/hw/ehca/ehca_irq.c
+++ b/drivers/infiniband/hw/ehca/ehca_irq.c
@@ -745,6 +745,7 @@ static int comp_pool_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
 		if(!create_comp_task(pool, cpu)) {
 			ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
@@ -752,24 +753,29 @@ static int comp_pool_callback(struct notifier_block *nfb,
 		}
 		break;
 	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
 		cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 		kthread_bind(cct->task, any_online_cpu(cpu_online_map));
 		destroy_comp_task(pool, cpu);
 		break;
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
 		cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 		kthread_bind(cct->task, cpu);
 		wake_up_process(cct->task);
 		break;
 	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
 		break;
 	case CPU_DOWN_FAILED:
+	case CPU_DOWN_FAILED_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
 		destroy_comp_task(pool, cpu);
 		take_over_work(pool, cpu);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index c8b8cfa332b..0d892600ff0 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2889,7 +2889,9 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
 
 	switch (val) {
 	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
 	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
 		       cpu);
 		decache_vcpus_on_cpu(cpu);
@@ -2897,6 +2899,7 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
 					 NULL, 0, 1);
 		break;
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
 		       cpu);
 		smp_call_function_single(cpu, kvm_arch_ops->hardware_enable,
diff --git a/fs/buffer.c b/fs/buffer.c
index fc2d763a8d7..aecd057cd0e 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2946,7 +2946,7 @@ static void buffer_exit_cpu(int cpu)
 static int buffer_cpu_notify(struct notifier_block *self,
 			      unsigned long action, void *hcpu)
 {
-	if (action == CPU_DEAD)
+	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
 		buffer_exit_cpu((unsigned long)hcpu);
 	return NOTIFY_OK;
 }
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index f5aa3ef855f..a96bde6df96 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1734,11 +1734,13 @@ xfs_icsb_cpu_notify(
 			per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
 	switch (action) {
 	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
 		/* Easy Case - initialize the area and locks, and
 		 * then rebalance when online does everything else for us. */
 		memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
 		break;
 	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
 		xfs_icsb_lock(mp);
 		xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0);
 		xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0);
@@ -1746,6 +1748,7 @@ xfs_icsb_cpu_notify(
 		xfs_icsb_unlock(mp);
 		break;
 	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
 		/* Disable all the counters, then fold the dead cpu's
 		 * count into the total on the global superblock and
 		 * re-enable the counters. */
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 1903e5490c0..9431101bf87 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -197,5 +197,17 @@ extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
 #define CPU_LOCK_ACQUIRE	0x0008 /* Acquire all hotcpu locks */
 #define CPU_LOCK_RELEASE	0x0009 /* Release all hotcpu locks */
 
+/* Used for CPU hotplug events occuring while tasks are frozen due to a suspend
+ * operation in progress
+ */
+#define CPU_TASKS_FROZEN	0x0010
+
+#define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
+#define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
+#define CPU_UP_CANCELED_FROZEN	(CPU_UP_CANCELED | CPU_TASKS_FROZEN)
+#define CPU_DOWN_PREPARE_FROZEN	(CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
+#define CPU_DOWN_FAILED_FROZEN	(CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
+#define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_NOTIFIER_H */
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 28cb6c71a47..369d2892687 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -120,12 +120,13 @@ static int take_cpu_down(void *unused)
 }
 
 /* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu)
+static int _cpu_down(unsigned int cpu, int tasks_frozen)
 {
 	int err, nr_calls = 0;
 	struct task_struct *p;
 	cpumask_t old_allowed, tmp;
 	void *hcpu = (void *)(long)cpu;
+	unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
 
 	if (num_online_cpus() == 1)
 		return -EBUSY;
@@ -134,11 +135,11 @@ static int _cpu_down(unsigned int cpu)
 		return -EINVAL;
 
 	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu);
-	err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE,
+	err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
 					hcpu, -1, &nr_calls);
 	if (err == NOTIFY_BAD) {
-		__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, hcpu,
-					  nr_calls, NULL);
+		__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
+					  hcpu, nr_calls, NULL);
 		printk("%s: attempt to take down CPU %u failed\n",
 				__FUNCTION__, cpu);
 		err = -EINVAL;
@@ -157,7 +158,7 @@ static int _cpu_down(unsigned int cpu)
 
 	if (IS_ERR(p) || cpu_online(cpu)) {
 		/* CPU didn't die: tell everyone.  Can't complain. */
-		if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED,
+		if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
 					    hcpu) == NOTIFY_BAD)
 			BUG();
 
@@ -176,7 +177,8 @@ static int _cpu_down(unsigned int cpu)
 	__cpu_die(cpu);
 
 	/* CPU is completely dead: tell everyone.  Too late to complain. */
-	if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD, hcpu) == NOTIFY_BAD)
+	if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
+				    hcpu) == NOTIFY_BAD)
 		BUG();
 
 	check_for_tasks(cpu);
@@ -186,8 +188,7 @@ out_thread:
 out_allowed:
 	set_cpus_allowed(current, old_allowed);
 out_release:
-	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE,
-						(void *)(long)cpu);
+	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu);
 	return err;
 }
 
@@ -199,7 +200,7 @@ int cpu_down(unsigned int cpu)
 	if (cpu_hotplug_disabled)
 		err = -EBUSY;
 	else
-		err = _cpu_down(cpu);
+		err = _cpu_down(cpu, 0);
 
 	mutex_unlock(&cpu_add_remove_lock);
 	return err;
@@ -207,16 +208,17 @@ int cpu_down(unsigned int cpu)
 #endif /*CONFIG_HOTPLUG_CPU*/
 
 /* Requires cpu_add_remove_lock to be held */
-static int __cpuinit _cpu_up(unsigned int cpu)
+static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
 {
 	int ret, nr_calls = 0;
 	void *hcpu = (void *)(long)cpu;
+	unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
 
 	if (cpu_online(cpu) || !cpu_present(cpu))
 		return -EINVAL;
 
 	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu);
-	ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu,
+	ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu,
 							-1, &nr_calls);
 	if (ret == NOTIFY_BAD) {
 		printk("%s: attempt to bring up CPU %u failed\n",
@@ -234,12 +236,12 @@ static int __cpuinit _cpu_up(unsigned int cpu)
 	BUG_ON(!cpu_online(cpu));
 
 	/* Now call notifier in preparation. */
-	raw_notifier_call_chain(&cpu_chain, CPU_ONLINE, hcpu);
+	raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
 
 out_notify:
 	if (ret != 0)
 		__raw_notifier_call_chain(&cpu_chain,
-				CPU_UP_CANCELED, hcpu, nr_calls, NULL);
+				CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
 	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu);
 
 	return re