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, 21 insertions, 33 deletions

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 884c0305e290..d1074d9b38ba 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -167,7 +167,7 @@ struct arm_ccn_dt {
 	struct hrtimer hrtimer;
 
 	cpumask_t cpu;
-	struct list_head entry;
+	struct hlist_node node;
 
 	struct pmu pmu;
 };
@@ -190,9 +190,6 @@ struct arm_ccn {
 	int mn_id;
 };
 
-static DEFINE_MUTEX(arm_ccn_mutex);
-static LIST_HEAD(arm_ccn_list);
-
 static int arm_ccn_node_to_xp(int node)
 {
 	return node / CCN_NUM_XP_PORTS;
@@ -1214,30 +1211,24 @@ static enum hrtimer_restart arm_ccn_pmu_timer_handler(struct hrtimer *hrtimer)
 }
 
 
-static int arm_ccn_pmu_offline_cpu(unsigned int cpu)
+static int arm_ccn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 {
-	struct arm_ccn_dt *dt;
+	struct arm_ccn_dt *dt = hlist_entry_safe(node, struct arm_ccn_dt, node);
+	struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt);
 	unsigned int target;
 
-	mutex_lock(&arm_ccn_mutex);
-	list_for_each_entry(dt, &arm_ccn_list, entry) {
-		struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt);
-
-		if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu))
-			continue;
-		target = cpumask_any_but(cpu_online_mask, cpu);
-		if (target >= nr_cpu_ids)
-			continue;
-		perf_pmu_migrate_context(&dt->pmu, cpu, target);
-		cpumask_set_cpu(target, &dt->cpu);
-		if (ccn->irq)
-			WARN_ON(irq_set_affinity_hint(ccn->irq, &dt->cpu) != 0);
-	}
-	mutex_unlock(&arm_ccn_mutex);
+	if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu))
+		return 0;
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+	perf_pmu_migrate_context(&dt->pmu, cpu, target);
+	cpumask_set_cpu(target, &dt->cpu);
+	if (ccn->irq)
+		WARN_ON(irq_set_affinity_hint(ccn->irq, &dt->cpu) != 0);
 	return 0;
 }
 
-
 static DEFINE_IDA(arm_ccn_pmu_ida);
 
 static int arm_ccn_pmu_init(struct arm_ccn *ccn)
@@ -1321,9 +1312,8 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn)
 	if (err)
 		goto error_pmu_register;
 
-	mutex_lock(&arm_ccn_mutex);
-	list_add(&ccn->dt.entry, &arm_ccn_list);
-	mutex_unlock(&arm_ccn_mutex);
+	cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+					 &ccn->dt.node);
 	return 0;
 
 error_pmu_register:
@@ -1339,10 +1329,8 @@ static void arm_ccn_pmu_cleanup(struct arm_ccn *ccn)
 {
 	int i;
 
-	mutex_lock(&arm_ccn_mutex);
-	list_del(&ccn->dt.entry);
-	mutex_unlock(&arm_ccn_mutex);
-
+	cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+					    &ccn->dt.node);
 	if (ccn->irq)
 		irq_set_affinity_hint(ccn->irq, NULL);
 	for (i = 0; i < ccn->num_xps; i++)
@@ -1573,9 +1561,9 @@ static int __init arm_ccn_init(void)
 {
 	int i, ret;
 
-	ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
-					"AP_PERF_ARM_CCN_ONLINE", NULL,
-					arm_ccn_pmu_offline_cpu);
+	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+				      "AP_PERF_ARM_CCN_ONLINE", NULL,
+				      arm_ccn_pmu_offline_cpu);
 	if (ret)
 		return ret;
 
@@ -1587,7 +1575,7 @@ static int __init arm_ccn_init(void)
 
 static void __exit arm_ccn_exit(void)
 {
-	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE);
+	cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CCN_ONLINE);
 	platform_driver_unregister(&arm_ccn_driver);
 }