arm/perf: Fix hotplug state machine conversion

[linux-beck.git] / drivers / perf / arm_pmu.c

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index ae9fc6c6add35b8cff3d0c5523e89b8275d64204..f6ab4f7f75bf97973227023e6d6933c6ca46ad98 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -685,6 +685,9 @@ 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
@@ -693,12 +696,17 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
  */
 static int arm_perf_starting_cpu(unsigned int cpu)
 {
-       if (!__oprofile_cpu_pmu)
-               return 0;
-       if (!cpumask_test_cpu(cpu, &__oprofile_cpu_pmu->supported_cpus))
-               return 0;
-       if (__oprofile_cpu_pmu->reset)
-               __oprofile_cpu_pmu->reset(__oprofile_cpu_pmu);
+       struct arm_pmu *pmu;
+
+       mutex_lock(&arm_pmu_mutex);
+       list_for_each_entry(pmu, &arm_pmu_list, entry) {
+
+               if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
+                       continue;
+               if (pmu->reset)
+                       pmu->reset(pmu);
+       }
+       mutex_unlock(&arm_pmu_mutex);
        return 0;
 }
 
@@ -810,11 +818,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        if (!cpu_hw_events)
                return -ENOMEM;
 
-       err = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_STARTING,
-                                       "AP_PERF_ARM_STARTING",
-                                       arm_perf_starting_cpu, NULL);
-       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)
@@ -850,8 +856,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        return 0;
 
 out_unregister:
-       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_STARTING);
-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;
 }
@@ -859,7 +866,9 @@ out_hw_events:
 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 {
        cpu_pm_pmu_unregister(cpu_pmu);
-       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_STARTING);
+       mutex_lock(&arm_pmu_mutex);
+       list_del(&cpu_pmu->entry);
+       mutex_unlock(&arm_pmu_mutex);
        free_percpu(cpu_pmu->hw_events);
 }
 
@@ -1019,8 +1028,6 @@ int arm_pmu_device_probe(struct platform_device *pdev,
        if (ret)
                goto out_destroy;
 
-       WARN(__oprofile_cpu_pmu, "%s(): missing PMU strucure for CPU-hotplug\n",
-            __func__);
        if (!__oprofile_cpu_pmu)
                __oprofile_cpu_pmu = pmu;
 
@@ -1038,3 +1045,17 @@ 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);