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authorLinus Torvalds <torvalds@linux-foundation.org>2016-07-29 23:55:30 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-29 23:55:30 +0300
commita6408f6cb63ac0958fee7dbce7861ffb540d8a49 (patch)
treec94a835d343974171951e3b805e6bbbb02852ebc /drivers/perf
parent1a81a8f2a5918956e214bb718099a89e500e7ec5 (diff)
parent4fae16dffb812f0e0d98a0b2b0856ca48ca63e6c (diff)
downloadlinux-a6408f6cb63ac0958fee7dbce7861ffb540d8a49.tar.xz
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner: "This is the next part of the hotplug rework. - Convert all notifiers with a priority assigned - Convert all CPU_STARTING/DYING notifiers The final removal of the STARTING/DYING infrastructure will happen when the merge window closes. Another 700 hundred line of unpenetrable maze gone :)" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) timers/core: Correct callback order during CPU hot plug leds/trigger/cpu: Move from CPU_STARTING to ONLINE level powerpc/numa: Convert to hotplug state machine arm/perf: Fix hotplug state machine conversion irqchip/armada: Avoid unused function warnings ARC/time: Convert to hotplug state machine clocksource/atlas7: Convert to hotplug state machine clocksource/armada-370-xp: Convert to hotplug state machine clocksource/exynos_mct: Convert to hotplug state machine clocksource/arm_global_timer: Convert to hotplug state machine rcu: Convert rcutree to hotplug state machine KVM/arm/arm64/vgic-new: Convert to hotplug state machine smp/cfd: Convert core to hotplug state machine x86/x2apic: Convert to CPU hotplug state machine profile: Convert to hotplug state machine timers/core: Convert to hotplug state machine hrtimer: Convert to hotplug state machine x86/tboot: Convert to hotplug state machine arm64/armv8 deprecated: Convert to hotplug state machine hwtracing/coresight-etm4x: Convert to hotplug state machine ...
Diffstat (limited to 'drivers/perf')
-rw-r--r--drivers/perf/arm_pmu.c59
1 files changed, 37 insertions, 22 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 8e4d7f590b06..6ccb994bdfcb 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -688,30 +688,29 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
return 0;
}
+static DEFINE_MUTEX(arm_pmu_mutex);
+static LIST_HEAD(arm_pmu_list);
+
/*
* PMU hardware loses all context when a CPU goes offline.
* When a CPU is hotplugged back in, since some hardware registers are
* UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
* junk values out of them.
*/
-static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
- void *hcpu)
+static int arm_perf_starting_cpu(unsigned int cpu)
{
- int cpu = (unsigned long)hcpu;
- struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);
-
- if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
- return NOTIFY_DONE;
-
- if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
- return NOTIFY_DONE;
+ struct arm_pmu *pmu;
- if (pmu->reset)
- pmu->reset(pmu);
- else
- return NOTIFY_DONE;
+ mutex_lock(&arm_pmu_mutex);
+ list_for_each_entry(pmu, &arm_pmu_list, entry) {
- return NOTIFY_OK;
+ if (!cpumask_test_cpu(cpu, &pmu->supported_cpus))
+ continue;
+ if (pmu->reset)
+ pmu->reset(pmu);
+ }
+ mutex_unlock(&arm_pmu_mutex);
+ return 0;
}
#ifdef CONFIG_CPU_PM
@@ -822,10 +821,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
if (!cpu_hw_events)
return -ENOMEM;
- cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
- err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
- if (err)
- goto out_hw_events;
+ mutex_lock(&arm_pmu_mutex);
+ list_add_tail(&cpu_pmu->entry, &arm_pmu_list);
+ mutex_unlock(&arm_pmu_mutex);
err = cpu_pm_pmu_register(cpu_pmu);
if (err)
@@ -861,8 +859,9 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
return 0;
out_unregister:
- unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
-out_hw_events:
+ mutex_lock(&arm_pmu_mutex);
+ list_del(&cpu_pmu->entry);
+ mutex_unlock(&arm_pmu_mutex);
free_percpu(cpu_hw_events);
return err;
}
@@ -870,7 +869,9 @@ out_hw_events:
static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
{
cpu_pm_pmu_unregister(cpu_pmu);
- unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
+ mutex_lock(&arm_pmu_mutex);
+ list_del(&cpu_pmu->entry);
+ mutex_unlock(&arm_pmu_mutex);
free_percpu(cpu_pmu->hw_events);
}
@@ -1061,3 +1062,17 @@ out_free:
kfree(pmu);
return ret;
}
+
+static int arm_pmu_hp_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+ "AP_PERF_ARM_STARTING",
+ arm_perf_starting_cpu, NULL);
+ if (ret)
+ pr_err("CPU hotplug notifier for ARM PMU could not be registered: %d\n",
+ ret);
+ return ret;
+}
+subsys_initcall(arm_pmu_hp_init);