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

From: tip-bot for Sebastian Andrzej Siewior
Date: Fri Sep 02 2016 - 04:24:57 EST


Commit-ID: ebade02256fd8a449445c7b27eacb093e22d7ee5
Gitweb: http://git.kernel.org/tip/ebade02256fd8a449445c7b27eacb093e22d7ee5
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Fri, 12 Aug 2016 19:49:42 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 1 Sep 2016 18:38:29 +0200

bus/arm-ccn: 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: Pawel Moll <pawel.moll@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: rt@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1471024183-12666-6-git-send-email-bigeasy@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
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 97a9185..fcf29f4 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;