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

[linux-2.6-microblaze.git] / drivers / perf / arm_pmu.c

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 8e4d7f5..6ccb994 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -688,30 +688,29 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
        return 0;
 }
 
+static DEFINE_MUTEX(arm_pmu_mutex);
+static LIST_HEAD(arm_pmu_list);
+
 /*
  * PMU hardware loses all context when a CPU goes offline.
  * When a CPU is hotplugged back in, since some hardware registers are
  * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
  * junk values out of them.
  */
-static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
-                         void *hcpu)
+static int arm_perf_starting_cpu(unsigned int cpu)
 {
-       int cpu = (unsigned long)hcpu;
-       struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);
-
-       if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
-               return NOTIFY_DONE;
-
-       if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
-               return NOTIFY_DONE;
+       struct arm_pmu *pmu;
 
-       if (pmu->reset)
-               pmu->reset(pmu);
-       else
-               return NOTIFY_DONE;
+       mutex_lock(&arm_pmu_mutex);
+       list_for_each_entry(pmu, &arm_pmu_list, entry) {
 
-       return NOTIFY_OK;
+               if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
+                       continue;
+               if (pmu->reset)
+                       pmu->reset(pmu);
+       }
+       mutex_unlock(&arm_pmu_mutex);
+       return 0;
 }
 
 #ifdef CONFIG_CPU_PM
@@ -822,10 +821,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        if (!cpu_hw_events)
                return -ENOMEM;
 
-       cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
-       err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
-       if (err)
-               goto out_hw_events;
+       mutex_lock(&arm_pmu_mutex);
+       list_add_tail(&cpu_pmu->entry, &arm_pmu_list);
+       mutex_unlock(&arm_pmu_mutex);
 
        err = cpu_pm_pmu_register(cpu_pmu);
        if (err)
@@ -861,8 +859,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        return 0;
 
 out_unregister:
-       unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
-out_hw_events:
+       mutex_lock(&arm_pmu_mutex);
+       list_del(&cpu_pmu->entry);
+       mutex_unlock(&arm_pmu_mutex);
        free_percpu(cpu_hw_events);
        return err;
 }
@@ -870,7 +869,9 @@ out_hw_events:
 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 {
        cpu_pm_pmu_unregister(cpu_pmu);
-       unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
+       mutex_lock(&arm_pmu_mutex);
+       list_del(&cpu_pmu->entry);
+       mutex_unlock(&arm_pmu_mutex);
        free_percpu(cpu_pmu->hw_events);
 }
 
@@ -1061,3 +1062,17 @@ out_free:
        kfree(pmu);
        return ret;
 }
+
+static int arm_pmu_hp_init(void)
+{
+       int ret;
+
+       ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+                                       "AP_PERF_ARM_STARTING",
+                                       arm_perf_starting_cpu, NULL);
+       if (ret)
+               pr_err("CPU hotplug notifier for ARM PMU could not be registered: %d\n",
+                      ret);
+       return ret;
+}
+subsys_initcall(arm_pmu_hp_init);