Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug updates from Thomas Gleixner:
 "This is the final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

1 files changed, 47 insertions, 77 deletions

diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index 88a2a3ba4212..8f7ef167c45a 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -639,7 +639,7 @@ static void iucv_disable(void)
         put_online_cpus();
 }
 
-static void free_iucv_data(int cpu)
+static int iucv_cpu_dead(unsigned int cpu)
 {
         kfree(iucv_param_irq[cpu]);
         iucv_param_irq[cpu] = NULL;
@@ -647,9 +647,10 @@ static void free_iucv_data(int cpu)
         iucv_param[cpu] = NULL;
         kfree(iucv_irq_data[cpu]);
         iucv_irq_data[cpu] = NULL;
+        return 0;
 }
 
-static int alloc_iucv_data(int cpu)
+static int iucv_cpu_prepare(unsigned int cpu)
 {
         /* Note: GFP_DMA used to get memory below 2G */
         iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
@@ -671,58 +672,38 @@ static int alloc_iucv_data(int cpu)
         return 0;
 
 out_free:
-        free_iucv_data(cpu);
+        iucv_cpu_dead(cpu);
         return -ENOMEM;
 }
 
-static int iucv_cpu_notify(struct notifier_block *self,
-                                     unsigned long action, void *hcpu)
+static int iucv_cpu_online(unsigned int cpu)
 {
-        cpumask_t cpumask;
-        long cpu = (long) hcpu;
-
-        switch (action) {
-        case CPU_UP_PREPARE:
-        case CPU_UP_PREPARE_FROZEN:
-                if (alloc_iucv_data(cpu))
-                        return notifier_from_errno(-ENOMEM);
-                break;
-        case CPU_UP_CANCELED:
-        case CPU_UP_CANCELED_FROZEN:
-        case CPU_DEAD:
-        case CPU_DEAD_FROZEN:
-                free_iucv_data(cpu);
-                break;
-        case CPU_ONLINE:
-        case CPU_ONLINE_FROZEN:
-        case CPU_DOWN_FAILED:
-        case CPU_DOWN_FAILED_FROZEN:
-                if (!iucv_path_table)
-                        break;
-                smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
-                break;
-        case CPU_DOWN_PREPARE:
-        case CPU_DOWN_PREPARE_FROZEN:
-                if (!iucv_path_table)
-                        break;
-                cpumask_copy(&cpumask, &iucv_buffer_cpumask);
-                cpumask_clear_cpu(cpu, &cpumask);
-                if (cpumask_empty(&cpumask))
-                        /* Can't offline last IUCV enabled cpu. */
-                        return notifier_from_errno(-EINVAL);
-                smp_call_function_single(cpu, iucv_retrieve_cpu, NULL, 1);
-                if (cpumask_empty(&iucv_irq_cpumask))
-                        smp_call_function_single(
-                                cpumask_first(&iucv_buffer_cpumask),
-                                iucv_allow_cpu, NULL, 1);
-                break;
-        }
-        return NOTIFY_OK;
+        if (!iucv_path_table)
+                return 0;
+        iucv_declare_cpu(NULL);
+        return 0;
 }
 
-static struct notifier_block __refdata iucv_cpu_notifier = {
-        .notifier_call = iucv_cpu_notify,
-};
+static int iucv_cpu_down_prep(unsigned int cpu)
+{
+        cpumask_t cpumask;
+
+        if (!iucv_path_table)
+                return 0;
+
+        cpumask_copy(&cpumask, &iucv_buffer_cpumask);
+        cpumask_clear_cpu(cpu, &cpumask);
+        if (cpumask_empty(&cpumask))
+                /* Can't offline last IUCV enabled cpu. */
+                return -EINVAL;
+
+        iucv_retrieve_cpu(NULL);
+        if (!cpumask_empty(&iucv_irq_cpumask))
+                return 0;
+        smp_call_function_single(cpumask_first(&iucv_buffer_cpumask),
+                                 iucv_allow_cpu, NULL, 1);
+        return 0;
+}
 
 /**
  * iucv_sever_pathid
@@ -2027,6 +2008,7 @@ struct iucv_interface iucv_if = {
 };
 EXPORT_SYMBOL(iucv_if);
 
+static enum cpuhp_state iucv_online;
 /**
  * iucv_init
  *
@@ -2035,7 +2017,6 @@ EXPORT_SYMBOL(iucv_if);
 static int __init iucv_init(void)
 {
         int rc;
-        int cpu;
 
         if (!MACHINE_IS_VM) {
                 rc = -EPROTONOSUPPORT;
@@ -2054,23 +2035,19 @@ static int __init iucv_init(void)
                 goto out_int;
         }
 
-        cpu_notifier_register_begin();
-
-        for_each_online_cpu(cpu) {
-                if (alloc_iucv_data(cpu)) {
-                        rc = -ENOMEM;
-                        goto out_free;
-                }
-        }
-        rc = __register_hotcpu_notifier(&iucv_cpu_notifier);
+        rc = cpuhp_setup_state(CPUHP_NET_IUCV_PREPARE, "net/iucv:prepare",
+                               iucv_cpu_prepare, iucv_cpu_dead);
         if (rc)
-                goto out_free;
-
-        cpu_notifier_register_done();
+                goto out_dev;
+        rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "net/iucv:online",
+                               iucv_cpu_online, iucv_cpu_down_prep);
+        if (rc < 0)
+                goto out_prep;
+        iucv_online = rc;
 
         rc = register_reboot_notifier(&iucv_reboot_notifier);
         if (rc)
-                goto out_cpu;
+                goto out_remove_hp;
         ASCEBC(iucv_error_no_listener, 16);
         ASCEBC(iucv_error_no_memory, 16);
         ASCEBC(iucv_error_pathid, 16);
@@ -2084,15 +2061,11 @@ static int __init iucv_init(void)
 
 out_reboot:
         unregister_reboot_notifier(&iucv_reboot_notifier);
-out_cpu:
-        cpu_notifier_register_begin();
-        __unregister_hotcpu_notifier(&iucv_cpu_notifier);
-out_free:
-        for_each_possible_cpu(cpu)
-                free_iucv_data(cpu);
-
-        cpu_notifier_register_done();
-
+out_remove_hp:
+        cpuhp_remove_state(iucv_online);
+out_prep:
+        cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
+out_dev:
         root_device_unregister(iucv_root);
 out_int:
         unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
@@ -2110,7 +2083,6 @@ out:
 static void __exit iucv_exit(void)
 {
         struct iucv_irq_list *p, *n;
-        int cpu;
 
         spin_lock_irq(&iucv_queue_lock);
         list_for_each_entry_safe(p, n, &iucv_task_queue, list)
@@ -2119,11 +2091,9 @@ static void __exit iucv_exit(void)
                 kfree(p);
         spin_unlock_irq(&iucv_queue_lock);
         unregister_reboot_notifier(&iucv_reboot_notifier);
-        cpu_notifier_register_begin();
-        __unregister_hotcpu_notifier(&iucv_cpu_notifier);
-        for_each_possible_cpu(cpu)
-                free_iucv_data(cpu);
-        cpu_notifier_register_done();
+
+        cpuhp_remove_state_nocalls(iucv_online);
+        cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
         root_device_unregister(iucv_root);
         bus_unregister(&iucv_bus);
         unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);