bus/arm-cci: Use cpu-hp's multi instance support instead custom list

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Cc: Olof Johansson <olof@lixom.net>
Link: http://lkml.kernel.org/r/1471024183-12666-5-git-send-email-bigeasy@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/bus/arm-cci.c

@@ -144,15 +144,12 @@ struct cci_pmu {
 	int num_cntrs;
 	atomic_t active_events;
 	struct mutex reserve_mutex;
-	struct list_head entry;
+	struct hlist_node node;
 	cpumask_t cpus;
 };
 
 #define to_cci_pmu(c)	(container_of(c, struct cci_pmu, pmu))
 
-static DEFINE_MUTEX(cci_pmu_mutex);
-static LIST_HEAD(cci_pmu_list);
-
 enum cci_models {
 #ifdef CONFIG_ARM_CCI400_PMU
 	CCI400_R0,
@@ -1506,25 +1503,21 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
 	return perf_pmu_register(&cci_pmu->pmu, name, -1);
 }
 
-static int cci_pmu_offline_cpu(unsigned int cpu)
+static int cci_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 {
-	struct cci_pmu *cci_pmu;
+	struct cci_pmu *cci_pmu = hlist_entry_safe(node, struct cci_pmu, node);
 	unsigned int target;
 
-	mutex_lock(&cci_pmu_mutex);
-	list_for_each_entry(cci_pmu, &cci_pmu_list, entry) {
 	if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
-			continue;
+		return 0;
 	target = cpumask_any_but(cpu_online_mask, cpu);
 	if (target >= nr_cpu_ids)
-			continue;
+		return 0;
 	/*
 	 * TODO: migrate context once core races on event->ctx have
 	 * been fixed.
 	 */
 	cpumask_set_cpu(target, &cci_pmu->cpus);
-	}
-	mutex_unlock(&cci_pmu_mutex);
 	return 0;
 }
 
@@ -1768,10 +1761,8 @@ static int cci_pmu_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	mutex_lock(&cci_pmu_mutex);
-	list_add(&cci_pmu->entry, &cci_pmu_list);
-	mutex_unlock(&cci_pmu_mutex);
-
+	cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+					 &cci_pmu->node);
 	pr_info("ARM %s PMU driver probed", cci_pmu->model->name);
 	return 0;
 }
@@ -1804,7 +1795,7 @@ static int __init cci_platform_init(void)
 {
 	int ret;
 
-	ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCI_ONLINE,
 				      "AP_PERF_ARM_CCI_ONLINE", NULL,
 				      cci_pmu_offline_cpu);
 	if (ret)