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>

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 140436a046c03f992c3fa3fd71ed485bfdb7d109..ae9fc6c6add35b8cff3d0c5523e89b8275d64204 100644 (file)
--- 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;
 

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 4c63cb30aee6c5fec58b901d7ecace9ba518edb9..a5b6a6526af831ea05fa8d6cf5df2c678bed787e 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -35,6 +35,7 @@ enum cpuhp_state {
        CPUHP_AP_PERF_X86_CSTATE_STARTING,
        CPUHP_AP_PERF_XTENSA_STARTING,
        CPUHP_AP_ARM_VFP_STARTING,
+       CPUHP_AP_PERF_ARM_STARTING,
        CPUHP_AP_NOTIFY_STARTING,
        CPUHP_AP_ONLINE,
        CPUHP_TEARDOWN_CPU,

diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index d28ac05c7f92935bf25286d8b14641bafdfee7e4..e6ed34eb2b2b56ac2e1ac61a32005152228faa68 100644 (file)
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -109,7 +109,6 @@ struct arm_pmu {
        DECLARE_BITMAP(pmceid_bitmap, ARMV8_PMUV3_MAX_COMMON_EVENTS);
        struct platform_device  *plat_device;
        struct pmu_hw_events    __percpu *hw_events;
-       struct notifier_block   hotplug_nb;
        struct notifier_block   cpu_pm_nb;
 };