[PATCH 5/6] bus/arm-ccn: Use cpu-hp's multi instance support instead custom list

[Sebastian Andrzej Siewior]

Cc: Arnd Bergmann <a...@arndb.de>
Cc: Pawel Moll <pawel.m...@arm.com>
Cc: Suzuki K Poulose <suzuki.poul...@arm.com>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
 drivers/bus/arm-ccn.c | 52 ++++++++++++++++++++-------------------------------
 1 file changed, 20 insertions(+), 32 deletions(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 97a9185af433..fcf29f416286 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -167,7 +167,7 @@ struct arm_ccn_dt {
        struct hrtimer hrtimer;
 
        cpumask_t cpu;
-       struct list_head entry;
+       struct hlist_node node;
 
        struct pmu pmu;
 };
@@ -189,9 +189,6 @@ struct arm_ccn {
        struct arm_ccn_dt dt;
 };
 
-static DEFINE_MUTEX(arm_ccn_mutex);
-static LIST_HEAD(arm_ccn_list);
-
 static int arm_ccn_node_to_xp(int node)
 {
        return node / CCN_NUM_XP_PORTS;
@@ -1173,30 +1170,24 @@ static enum hrtimer_restart 
arm_ccn_pmu_timer_handler(struct hrtimer *hrtimer)
 }
 
 
-static int arm_ccn_pmu_offline_cpu(unsigned int cpu)
+static int arm_ccn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 {
-       struct arm_ccn_dt *dt;
+       struct arm_ccn_dt *dt = hlist_entry_safe(node, struct arm_ccn_dt, node);
+       struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt);
        unsigned int target;
 
-       mutex_lock(&arm_ccn_mutex);
-       list_for_each_entry(dt, &arm_ccn_list, entry) {
-               struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt);
-
-               if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu))
-                       continue;
-               target = cpumask_any_but(cpu_online_mask, cpu);
-               if (target >= nr_cpu_ids)
-                       continue;
-               perf_pmu_migrate_context(&dt->pmu, cpu, target);
-               cpumask_set_cpu(target, &dt->cpu);
-               if (ccn->irq)
-                       WARN_ON(irq_set_affinity_hint(ccn->irq, &dt->cpu) != 0);
-       }
-       mutex_unlock(&arm_ccn_mutex);
+       if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu))
+               return 0;
+       target = cpumask_any_but(cpu_online_mask, cpu);
+       if (target >= nr_cpu_ids)
+               return 0;
+       perf_pmu_migrate_context(&dt->pmu, cpu, target);
+       cpumask_set_cpu(target, &dt->cpu);
+       if (ccn->irq)
+               WARN_ON(irq_set_affinity_hint(ccn->irq, &dt->cpu) != 0);
        return 0;
 }
 
-
 static DEFINE_IDA(arm_ccn_pmu_ida);
 
 static int arm_ccn_pmu_init(struct arm_ccn *ccn)
@@ -1278,9 +1269,8 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn)
        if (err)
                goto error_pmu_register;
 
-       mutex_lock(&arm_ccn_mutex);
-       list_add(&ccn->dt.entry, &arm_ccn_list);
-       mutex_unlock(&arm_ccn_mutex);
+       cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+                                        &ccn->dt.node);
        return 0;
 
 error_pmu_register:
@@ -1296,10 +1286,8 @@ static void arm_ccn_pmu_cleanup(struct arm_ccn *ccn)
 {
        int i;
 
-       mutex_lock(&arm_ccn_mutex);
-       list_del(&ccn->dt.entry);
-       mutex_unlock(&arm_ccn_mutex);
-
+       cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+                                           &ccn->dt.node);
        if (ccn->irq)
                irq_set_affinity_hint(ccn->irq, NULL);
        for (i = 0; i < ccn->num_xps; i++)
@@ -1527,9 +1515,9 @@ static int __init arm_ccn_init(void)
 {
        int i, ret;
 
-       ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
-                                       "AP_PERF_ARM_CCN_ONLINE", NULL,
-                                       arm_ccn_pmu_offline_cpu);
+       ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCN_ONLINE,
+                                     "AP_PERF_ARM_CCN_ONLINE", NULL,
+                                     arm_ccn_pmu_offline_cpu);
        if (ret)
                return ret;
 
-- 
2.8.1