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 f5e1008..b37b572 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -534,6 +534,24 @@ static int armpmu_filter_match(struct perf_event *event)
        return cpumask_test_cpu(cpu, &armpmu->supported_cpus);
 }
 
+static ssize_t armpmu_cpumask_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+       struct arm_pmu *armpmu = to_arm_pmu(dev_get_drvdata(dev));
+       return cpumap_print_to_pagebuf(true, buf, &armpmu->supported_cpus);
+}
+
+static DEVICE_ATTR(cpus, S_IRUGO, armpmu_cpumask_show, NULL);
+
+static struct attribute *armpmu_common_attrs[] = {
+       &dev_attr_cpus.attr,
+       NULL,
+};
+
+static struct attribute_group armpmu_common_attr_group = {
+       .attrs = armpmu_common_attrs,
+};
+
 static void armpmu_init(struct arm_pmu *armpmu)
 {
        atomic_set(&armpmu->active_events, 0);
@@ -549,7 +567,10 @@ static void armpmu_init(struct arm_pmu *armpmu)
                .stop           = armpmu_stop,
                .read           = armpmu_read,
                .filter_match   = armpmu_filter_match,
+               .attr_groups    = armpmu->attr_groups,
        };
+       armpmu->attr_groups[ARMPMU_ATTR_GROUP_COMMON] =
+               &armpmu_common_attr_group;
 }
 
 /* Set at runtime when we know what CPU type we are. */
@@ -602,7 +623,7 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
        irqs = min(pmu_device->num_resources, num_possible_cpus());
 
        irq = platform_get_irq(pmu_device, 0);
-       if (irq >= 0 && irq_is_percpu(irq)) {
+       if (irq > 0 && irq_is_percpu(irq)) {
                on_each_cpu_mask(&cpu_pmu->supported_cpus,
                                 cpu_pmu_disable_percpu_irq, &irq, 1);
                free_percpu_irq(irq, &hw_events->percpu_pmu);
@@ -616,7 +637,7 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
                        if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs))
                                continue;
                        irq = platform_get_irq(pmu_device, i);
-                       if (irq >= 0)
+                       if (irq > 0)
                                free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
                }
        }
@@ -638,7 +659,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
        }
 
        irq = platform_get_irq(pmu_device, 0);
-       if (irq >= 0 && irq_is_percpu(irq)) {
+       if (irq > 0 && irq_is_percpu(irq)) {
                err = request_percpu_irq(irq, handler, "arm-pmu",
                                         &hw_events->percpu_pmu);
                if (err) {
@@ -688,28 +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;
 }
 
@@ -821,9 +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)
@@ -859,9 +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;
 }
@@ -869,9 +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);
 }
 
@@ -919,7 +932,7 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
 
                /* Check the IRQ type and prohibit a mix of PPIs and SPIs */
                irq = platform_get_irq(pdev, i);
-               if (irq >= 0) {
+               if (irq > 0) {
                        bool spi = !irq_is_percpu(irq);
 
                        if (i > 0 && spi != using_spi) {
@@ -970,7 +983,7 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
        if (cpumask_weight(&pmu->supported_cpus) == 0) {
                int irq = platform_get_irq(pdev, 0);
 
-               if (irq >= 0 && irq_is_percpu(irq)) {
+               if (irq > 0 && irq_is_percpu(irq)) {
                        /* If using PPIs, check the affinity of the partition */
                        int ret;
 
@@ -1029,7 +1042,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
                ret = of_pmu_irq_cfg(pmu);
                if (!ret)
                        ret = init_fn(pmu);
-       } else {
+       } else if (probe_table) {
                cpumask_setall(&pmu->supported_cpus);
                ret = probe_current_pmu(pmu, probe_table);
        }
@@ -1039,6 +1052,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
                goto out_free;
        }
 
+
        ret = cpu_pmu_init(pmu);
        if (ret)
                goto out_free;
@@ -1069,9 +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);