[tip:smp/hotplug] bus/arm-cci: Use cpu-hp's multi instance support instead custom list

From: tip-bot for Sebastian Andrzej Siewior
Date: Fri Sep 02 2016 - 04:25:55 EST


Commit-ID: 29d6e64595f7fddb3c418a190f71409b0ff6bae8
Gitweb: http://git.kernel.org/tip/29d6e64595f7fddb3c418a190f71409b0ff6bae8
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Fri, 12 Aug 2016 19:49:41 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 1 Sep 2016 18:38:29 +0200

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

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

---
drivers/bus/arm-cci.c | 45 ++++++++++++++++++---------------------------
1 file changed, 18 insertions(+), 27 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 5755907f..4c44ba2 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;