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bus: arm-cci: Fix use of smp_processor_id() in preemptible context

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The ARM CCI driver seem to be using smp_processor_id() in a
preemptible context, which is likely to make a DEBUG_PREMPT
kernel scream at boot time.

Turn this into a get_cpu()/put_cpu() that extends over the CPU
hotplug registration, making sure that we don't race against
a CPU down operation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
This commit is contained in:
Marc Zyngier 2017-10-03 18:14:13 +01:00 committed by Pawel Moll
parent b18c2b9487
commit 4608af8aa5
1 changed files with 5 additions and 2 deletions
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7
drivers/bus/arm-cci.c
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@ -1755,14 +1755,17 @@ static int cci_pmu_probe(struct platform_device *pdev)
raw_spin_lock_init(&cci_pmu->hw_events.pmu_lock);
mutex_init(&cci_pmu->reserve_mutex);
atomic_set(&cci_pmu->active_events, 0);
cpumask_set_cpu(smp_processor_id(), &cci_pmu->cpus);
cpumask_set_cpu(get_cpu(), &cci_pmu->cpus);
ret = cci_pmu_init(cci_pmu, pdev);
if (ret)
if (ret) {
put_cpu();
return ret;
}
cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
&cci_pmu->node);
put_cpu();
pr_info("ARM %s PMU driver probed", cci_pmu->model->name);
return 0;
}