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

[cascardo/linux.git] / drivers / perf / arm_pmu.c

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 3037081..b37b572 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -709,28 +709,20 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
        return 0;
 }
 
-static DEFINE_SPINLOCK(arm_pmu_lock);
-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 arm_perf_starting_cpu(unsigned int cpu)
+static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)
 {
-       struct arm_pmu *pmu;
-
-       spin_lock(&arm_pmu_lock);
-       list_for_each_entry(pmu, &arm_pmu_list, entry) {
+       struct arm_pmu *pmu = hlist_entry_safe(node, struct arm_pmu, node);
 
-               if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
-                       continue;
-               if (pmu->reset)
-                       pmu->reset(pmu);
-       }
-       spin_unlock(&arm_pmu_lock);
+       if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
+               return 0;
+       if (pmu->reset)
+               pmu->reset(pmu);
        return 0;
 }
 
@@ -842,9 +834,10 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        if (!cpu_hw_events)
                return -ENOMEM;
 
-       spin_lock(&arm_pmu_lock);
-       list_add_tail(&cpu_pmu->entry, &arm_pmu_list);
-       spin_unlock(&arm_pmu_lock);
+       err = cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+                                              &cpu_pmu->node);
+       if (err)
+               goto out_free;
 
        err = cpu_pm_pmu_register(cpu_pmu);
        if (err)
@@ -880,9 +873,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
        return 0;
 
 out_unregister:
-       spin_lock(&arm_pmu_lock);
-       list_del(&cpu_pmu->entry);
-       spin_unlock(&arm_pmu_lock);
+       cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+                                           &cpu_pmu->node);
+out_free:
        free_percpu(cpu_hw_events);
        return err;
 }
@@ -890,9 +883,8 @@ out_unregister:
 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 {
        cpu_pm_pmu_unregister(cpu_pmu);
-       spin_lock(&arm_pmu_lock);
-       list_del(&cpu_pmu->entry);
-       spin_unlock(&arm_pmu_lock);
+       cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+                                           &cpu_pmu->node);
        free_percpu(cpu_pmu->hw_events);
 }
 
@@ -1091,9 +1083,9 @@ 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);
+       ret = cpuhp_setup_state_multi(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);