arm/perf: Convert to hotplug state machine

Straight forward conversion w/o bells and whistles.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.794097159@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 15 insertions, 21 deletions

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 140436a046c0..ae9fc6c6add3 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -691,24 +691,15 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
  * 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;
-
-        if (pmu->reset)
-                pmu->reset(pmu);
-        else
-                return NOTIFY_DONE;
-
-        return NOTIFY_OK;
+        if (!__oprofile_cpu_pmu)
+                return 0;
+        if (!cpumask_test_cpu(cpu, &__oprofile_cpu_pmu->supported_cpus))
+                return 0;
+        if (__oprofile_cpu_pmu->reset)
+                __oprofile_cpu_pmu->reset(__oprofile_cpu_pmu);
+        return 0;
 }
 
 #ifdef CONFIG_CPU_PM
@@ -819,8 +810,9 @@ 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);
+        err = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_STARTING,
+                                        "AP_PERF_ARM_STARTING",
+                                        arm_perf_starting_cpu, NULL);
         if (err)
                 goto out_hw_events;
 
@@ -858,7 +850,7 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
         return 0;
 
 out_unregister:
-        unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
+        cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_STARTING);
 out_hw_events:
         free_percpu(cpu_hw_events);
         return err;
@@ -867,7 +859,7 @@ 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);
+        cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_STARTING);
         free_percpu(cpu_pmu->hw_events);
 }
 
@@ -1027,6 +1019,8 @@ int arm_pmu_device_probe(struct platform_device *pdev,
         if (ret)
                 goto out_destroy;
 
+        WARN(__oprofile_cpu_pmu, "%s(): missing PMU strucure for CPU-hotplug\n",
+             __func__);
         if (!__oprofile_cpu_pmu)
                 __oprofile_cpu_pmu = pmu;