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.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 18 insertions, 27 deletions

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 5755907f836f..4c44ba2d3412 100644
--- a/drivers/bus/arm-cci.c
+++ b/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;
-                target = cpumask_any_but(cpu_online_mask, cpu);
-                if (target >= nr_cpu_ids)
-                        continue;
-                /*
-                 * TODO: migrate context once core races on event->ctx have
-                 * been fixed.
-                 */
-                cpumask_set_cpu(target, &cci_pmu->cpus);
-        }
-        mutex_unlock(&cci_pmu_mutex);
+        if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
+                return 0;
+        target = cpumask_any_but(cpu_online_mask, cpu);
+        if (target >= nr_cpu_ids)
+                return 0;
+        /*
+         * TODO: migrate context once core races on event->ctx have
+         * been fixed.
+         */
+        cpumask_set_cpu(target, &cci_pmu->cpus);
         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;
 }
@@ -1804,9 +1795,9 @@ static int __init cci_platform_init(void)
 {
         int ret;
 
-        ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
-                                        "AP_PERF_ARM_CCI_ONLINE", NULL,
-                                        cci_pmu_offline_cpu);
+        ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+                                      "AP_PERF_ARM_CCI_ONLINE", NULL,
+                                      cci_pmu_offline_cpu);
         if (ret)
                 return ret;