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
  ...

3 files changed, 51 insertions, 118 deletions

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index ffa7c9dcbd7a..890082315054 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -144,15 +144,12 @@ struct cci_pmu {
         int num_cntrs;
         atomic_t active_events;
         struct mutex reserve_mutex;
-        struct list_head entry;
+        struct hlist_node node;
         cpumask_t cpus;
 };
 
 #define to_cci_pmu(c)   (container_of(c, struct cci_pmu, pmu))
 
-static DEFINE_MUTEX(cci_pmu_mutex);
-static LIST_HEAD(cci_pmu_list);
-
 enum cci_models {
 #ifdef CONFIG_ARM_CCI400_PMU
         CCI400_R0,
@@ -1506,25 +1503,21 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
         return perf_pmu_register(&cci_pmu->pmu, name, -1);
 }
 
-static int cci_pmu_offline_cpu(unsigned int cpu)
+static int cci_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 {
-        struct cci_pmu *cci_pmu;
+        struct cci_pmu *cci_pmu = hlist_entry_safe(node, struct cci_pmu, node);
         unsigned int target;
 
-        mutex_lock(&cci_pmu_mutex);
-        list_for_each_entry(cci_pmu, &cci_pmu_list, entry) {
-                if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
-                        continue;
-                target = cpumask_any_but(cpu_online_mask, cpu);
-                if (target >= nr_cpu_ids)
-                        continue;
-                /*
-                 * TODO: migrate context once core races on event->ctx have
-                 * been fixed.
-                 */
-                cpumask_set_cpu(target, &cci_pmu->cpus);
-        }
-        mutex_unlock(&cci_pmu_mutex);
+        if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
+                return 0;
+        target = cpumask_any_but(cpu_online_mask, cpu);
+        if (target >= nr_cpu_ids)
+                return 0;
+        /*
+         * TODO: migrate context once core races on event->ctx have
+         * been fixed.
+         */
+        cpumask_set_cpu(target, &cci_pmu->cpus);
         return 0;
 }
 
@@ -1768,10 +1761,8 @@ static int cci_pmu_probe(struct platform_device *pdev)
         if (ret)
                 return ret;
 
-        mutex_lock(&cci_pmu_mutex);
-        list_add(&cci_pmu->entry, &cci_pmu_list);
-        mutex_unlock(&cci_pmu_mutex);
-
+        cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+                                         &cci_pmu->node);
         pr_info("ARM %s PMU driver probed", cci_pmu->model->name);
         return 0;
 }
@@ -1804,9 +1795,9 @@ static int __init cci_platform_init(void)
 {
         int ret;
 
-        ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
-                                        "AP_PERF_ARM_CCI_ONLINE", NULL,
-                                        cci_pmu_offline_cpu);
+        ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+                                      "AP_PERF_ARM_CCI_ONLINE", NULL,
+                                      cci_pmu_offline_cpu);
         if (ret)
                 return ret;
 
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);
 }
 
diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c
index cad49bc38b3e..1b14256376d2 100644
--- a/drivers/bus/mips_cdmm.c
+++ b/drivers/bus/mips_cdmm.c
@@ -596,19 +596,20 @@ BUILD_PERDEV_HELPER(cpu_down)       /* int mips_cdmm_cpu_down_helper(...) */
 BUILD_PERDEV_HELPER(cpu_up)         /* int mips_cdmm_cpu_up_helper(...) */
 
 /**
- * mips_cdmm_bus_down() - Tear down the CDMM bus.
- * @data:       Pointer to unsigned int CPU number.
+ * mips_cdmm_cpu_down_prep() - Callback for CPUHP DOWN_PREP:
+ *                             Tear down the CDMM bus.
+ * @cpu:        unsigned int CPU number.
  *
  * This function is executed on the hotplugged CPU and calls the CDMM
  * driver cpu_down callback for all devices on that CPU.
  */
-static long mips_cdmm_bus_down(void *data)
+static int mips_cdmm_cpu_down_prep(unsigned int cpu)
 {
         struct mips_cdmm_bus *bus;
         long ret;
 
         /* Inform all the devices on the bus */
-        ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, data,
+        ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu,
                                mips_cdmm_cpu_down_helper);
 
         /*
@@ -623,8 +624,8 @@ static long mips_cdmm_bus_down(void *data)
 }
 
 /**
- * mips_cdmm_bus_up() - Bring up the CDMM bus.
- * @data:       Pointer to unsigned int CPU number.
+ * mips_cdmm_cpu_online() - Callback for CPUHP ONLINE: Bring up the CDMM bus.
+ * @cpu:        unsigned int CPU number.
  *
  * This work_on_cpu callback function is executed on a given CPU to discover
  * CDMM devices on that CPU, or to call the CDMM driver cpu_up callback for all
@@ -634,7 +635,7 @@ static long mips_cdmm_bus_down(void *data)
  * initialisation. When CPUs are brought online the function is
  * invoked directly on the hotplugged CPU.
  */
-static long mips_cdmm_bus_up(void *data)
+static int mips_cdmm_cpu_online(unsigned int cpu)
 {
         struct mips_cdmm_bus *bus;
         long ret;
@@ -651,51 +652,13 @@ static long mips_cdmm_bus_up(void *data)
                 mips_cdmm_bus_discover(bus);
         else
                 /* Inform all the devices on the bus */
-                ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, data,
+                ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu,
                                        mips_cdmm_cpu_up_helper);
 
         return ret;
 }
 
 /**
- * mips_cdmm_cpu_notify() - Take action when a CPU is going online or offline.
- * @nb:         CPU notifier block .
- * @action:     Event that has taken place (CPU_*).
- * @data:       CPU number.
- *
- * This notifier is used to keep the CDMM buses updated as CPUs are offlined and
- * onlined. When CPUs go offline or come back online, so does their CDMM bus, so
- * devices must be informed. Also when CPUs come online for the first time the
- * devices on the CDMM bus need discovering.
- *
- * Returns:     NOTIFY_OK if event was used.
- *              NOTIFY_DONE if we didn't care.
- */
-static int mips_cdmm_cpu_notify(struct notifier_block *nb,
-                                unsigned long action, void *data)
-{
-        unsigned int cpu = (unsigned int)data;
-
-        switch (action & ~CPU_TASKS_FROZEN) {
-        case CPU_ONLINE:
-        case CPU_DOWN_FAILED:
-                mips_cdmm_bus_up(&cpu);
-                break;
-        case CPU_DOWN_PREPARE:
-                mips_cdmm_bus_down(&cpu);
-                break;
-        default:
-                return NOTIFY_DONE;
-        }
-
-        return NOTIFY_OK;
-}
-
-static struct notifier_block mips_cdmm_cpu_nb = {
-        .notifier_call = mips_cdmm_cpu_notify,
-};
-
-/**
  * mips_cdmm_init() - Initialise CDMM bus.
  *
  * Initialise CDMM bus, discover CDMM devices for online CPUs, and arrange for
@@ -703,7 +666,6 @@ static struct notifier_block mips_cdmm_cpu_nb = {
  */
 static int __init mips_cdmm_init(void)
 {
-        unsigned int cpu;
         int ret;
 
         /* Register the bus */
@@ -712,19 +674,11 @@ static int __init mips_cdmm_init(void)
                 return ret;
 
         /* We want to be notified about new CPUs */
-        ret = register_cpu_notifier(&mips_cdmm_cpu_nb);
-        if (ret) {
+        ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "bus/cdmm:online",
+                                mips_cdmm_cpu_online, mips_cdmm_cpu_down_prep);
+        if (ret < 0)
                 pr_warn("cdmm: Failed to register CPU notifier\n");
-                goto out;
-        }
-
-        /* Discover devices on CDMM of online CPUs */
-        for_each_online_cpu(cpu)
-                work_on_cpu(cpu, mips_cdmm_bus_up, &cpu);
 
-        return 0;
-out:
-        bus_unregister(&mips_cdmm_bustype);
         return ret;
 }
 subsys_initcall(mips_cdmm_init);