From: Sebastian Andrzej Siewior <[email protected]> Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs.
Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Cc: Pawel Moll <[email protected]> Signed-off-by: Anna-Maria Gleixner <[email protected]> --- drivers/bus/arm-ccn.c | 47 ++++++++++++++++++++------------------------- include/linux/cpuhotplug.h | 2 + 2 files changed, 23 insertions(+), 26 deletions(-) --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -167,7 +167,6 @@ struct arm_ccn_dt { struct hrtimer hrtimer; cpumask_t cpu; - struct notifier_block cpu_nb; struct pmu pmu; }; @@ -1171,30 +1170,23 @@ static enum hrtimer_restart arm_ccn_pmu_ } -static int arm_ccn_pmu_cpu_notifier(struct notifier_block *nb, - unsigned long action, void *hcpu) +static struct arm_ccn_dt *cpuhp_armccn_dt; +static int arm_ccn_pmu_offline_cpu(unsigned int cpu) { - struct arm_ccn_dt *dt = container_of(nb, struct arm_ccn_dt, cpu_nb); + struct arm_ccn_dt *dt = cpuhp_armccn_dt; struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt); - unsigned int cpu = (long)hcpu; /* for (long) see kernel/cpu.c */ unsigned int target; - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_DOWN_PREPARE: - if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu)) - break; - target = cpumask_any_but(cpu_online_mask, cpu); - if (target >= nr_cpu_ids) - break; - 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); - default: - break; - } - - return NOTIFY_OK; + 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; } @@ -1270,9 +1262,10 @@ static int arm_ccn_pmu_init(struct arm_c * ... and change the selection when it goes offline. Priority is * picked to have a chance to migrate events before perf is notified. */ - ccn->dt.cpu_nb.notifier_call = arm_ccn_pmu_cpu_notifier; - ccn->dt.cpu_nb.priority = CPU_PRI_PERF + 1, - err = register_cpu_notifier(&ccn->dt.cpu_nb); + cpuhp_armccn_dt = &ccn->dt; + err = cpuhp_setup_state(CPUHP_AP_PERF_ARM_CCN_ONLINE, + "AP_PERF_ARM_CCN_ONLINE", NULL, + arm_ccn_pmu_offline_cpu); if (err) goto error_cpu_notifier; @@ -1293,7 +1286,8 @@ static int arm_ccn_pmu_init(struct arm_c error_pmu_register: error_set_affinity: - unregister_cpu_notifier(&ccn->dt.cpu_nb); + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE); + cpuhp_armccn_dt = NULL; error_cpu_notifier: ida_simple_remove(&arm_ccn_pmu_ida, ccn->dt.id); for (i = 0; i < ccn->num_xps; i++) @@ -1308,7 +1302,8 @@ static void arm_ccn_pmu_cleanup(struct a if (ccn->irq) irq_set_affinity_hint(ccn->irq, NULL); - unregister_cpu_notifier(&ccn->dt.cpu_nb); + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE); + cpuhp_armccn_dt = NULL; for (i = 0; i < ccn->num_xps; i++) writel(0, ccn->xp[i].base + CCN_XP_DT_CONTROL); writel(0, ccn->dt.base + CCN_DT_PMCR); --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -30,6 +30,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_AMD_IBS_STARTING, CPUHP_AP_PERF_X86_CQM_STARTING, CPUHP_AP_PERF_X86_CSTATE_STARTING, + CPUHP_AP_PERF_XTENSA_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE, CPUHP_TEARDOWN_CPU, @@ -46,6 +47,7 @@ enum cpuhp_state { CPUHP_AP_PERF_S390_CF_ONLINE, CPUHP_AP_PERF_S390_SF_ONLINE, CPUHP_AP_PERF_ARM_CCI_ONLINE, + CPUHP_AP_PERF_ARM_CCN_ONLINE, CPUHP_AP_NOTIFY_ONLINE, CPUHP_AP_ONLINE_DYN, CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
