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
  ...

1 files changed, 50 insertions, 38 deletions

diff --git a/kernel/padata.c b/kernel/padata.c
index 993278895ccc..7848f0566403 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -30,6 +30,7 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/rcupdate.h>
+#include <linux/module.h>
 
 #define MAX_OBJ_NUM 1000
 
@@ -769,52 +770,43 @@ static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
 		cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
 }
 
-
-static int padata_cpu_callback(struct notifier_block *nfb,
-			       unsigned long action, void *hcpu)
+static int padata_cpu_online(unsigned int cpu, struct hlist_node *node)
 {
-	int err;
 	struct padata_instance *pinst;
-	int cpu = (unsigned long)hcpu;
+	int ret;
 
-	pinst = container_of(nfb, struct padata_instance, cpu_notifier);
+	pinst = hlist_entry_safe(node, struct padata_instance, node);
+	if (!pinst_has_cpu(pinst, cpu))
+		return 0;
 
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-	case CPU_DOWN_FAILED:
-	case CPU_DOWN_FAILED_FROZEN:
-		if (!pinst_has_cpu(pinst, cpu))
-			break;
-		mutex_lock(&pinst->lock);
-		err = __padata_add_cpu(pinst, cpu);
-		mutex_unlock(&pinst->lock);
-		if (err)
-			return notifier_from_errno(err);
-		break;
+	mutex_lock(&pinst->lock);
+	ret = __padata_add_cpu(pinst, cpu);
+	mutex_unlock(&pinst->lock);
+	return ret;
+}
 
-	case CPU_DOWN_PREPARE:
-	case CPU_DOWN_PREPARE_FROZEN:
-	case CPU_UP_CANCELED:
-	case CPU_UP_CANCELED_FROZEN:
-		if (!pinst_has_cpu(pinst, cpu))
-			break;
-		mutex_lock(&pinst->lock);
-		err = __padata_remove_cpu(pinst, cpu);
-		mutex_unlock(&pinst->lock);
-		if (err)
-			return notifier_from_errno(err);
-		break;
-	}
+static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node)
+{
+	struct padata_instance *pinst;
+	int ret;
+
+	pinst = hlist_entry_safe(node, struct padata_instance, node);
+	if (!pinst_has_cpu(pinst, cpu))
+		return 0;
 
-	return NOTIFY_OK;
+	mutex_lock(&pinst->lock);
+	ret = __padata_remove_cpu(pinst, cpu);
+	mutex_unlock(&pinst->lock);
+	return ret;
 }
+
+static enum cpuhp_state hp_online;
 #endif
 
 static void __padata_free(struct padata_instance *pinst)
 {
 #ifdef CONFIG_HOTPLUG_CPU
-	unregister_hotcpu_notifier(&pinst->cpu_notifier);
+	cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
 #endif
 
 	padata_stop(pinst);
@@ -1012,11 +1004,8 @@ struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 	mutex_init(&pinst->lock);
 
 #ifdef CONFIG_HOTPLUG_CPU
-	pinst->cpu_notifier.notifier_call = padata_cpu_callback;
-	pinst->cpu_notifier.priority = 0;
-	register_hotcpu_notifier(&pinst->cpu_notifier);
+	cpuhp_state_add_instance_nocalls(hp_online, &pinst->node);
 #endif
-
 	return pinst;
 
 err_free_masks:
@@ -1039,3 +1028,26 @@ void padata_free(struct padata_instance *pinst)
 	kobject_put(&pinst->kobj);
 }
 EXPORT_SYMBOL(padata_free);
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static __init int padata_driver_init(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
+				      padata_cpu_online,
+				      padata_cpu_prep_down);
+	if (ret < 0)
+		return ret;
+	hp_online = ret;
+	return 0;
+}
+module_init(padata_driver_init);
+
+static __exit void padata_driver_exit(void)
+{
+	cpuhp_remove_multi_state(hp_online);
+}
+module_exit(padata_driver_exit);
+#endif