From 6b2c28471de550308784560206c3365e5179d42f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Jul 2016 17:17:00 +0000 Subject: [PATCH] x86/x2apic: Convert to CPU hotplug state machine 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 Signed-off-by: Anna-Maria Gleixner Cc: Len Brown Cc: Linus Torvalds Cc: Mathias Krause Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.736898691@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/x2apic_cluster.c | 80 ++++++++++----------------- include/linux/cpuhotplug.h | 1 + 2 files changed, 31 insertions(+), 50 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index aca8b75c1552..b5da5a8e5e45 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -152,68 +152,48 @@ static void init_x2apic_ldr(void) } } - /* - * At CPU state changes, update the x2apic cluster sibling info. - */ -static int -update_clusterinfo(struct notifier_block *nfb, unsigned long action, void *hcpu) +/* + * At CPU state changes, update the x2apic cluster sibling info. + */ +int x2apic_prepare_cpu(unsigned int cpu) { - unsigned int this_cpu = (unsigned long)hcpu; - unsigned int cpu; - int err = 0; - - switch (action) { - case CPU_UP_PREPARE: - if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, this_cpu), - GFP_KERNEL)) { - err = -ENOMEM; - } else if (!zalloc_cpumask_var(&per_cpu(ipi_mask, this_cpu), - GFP_KERNEL)) { - free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu)); - err = -ENOMEM; - } - break; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DEAD: - for_each_online_cpu(cpu) { - if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu)) - continue; - cpumask_clear_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu)); - cpumask_clear_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu)); - } - free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu)); - free_cpumask_var(per_cpu(ipi_mask, this_cpu)); - break; + if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL)) + return -ENOMEM; + + if (!zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL)) { + free_cpumask_var(per_cpu(cpus_in_cluster, cpu)); + return -ENOMEM; } - return notifier_from_errno(err); + return 0; } -static struct notifier_block x2apic_cpu_notifier = { - .notifier_call = update_clusterinfo, -}; - -static int x2apic_init_cpu_notifier(void) +int x2apic_dead_cpu(unsigned int this_cpu) { - int cpu = smp_processor_id(); - - zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL); - zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL); + int cpu; - BUG_ON(!per_cpu(cpus_in_cluster, cpu) || !per_cpu(ipi_mask, cpu)); - - cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu)); - register_hotcpu_notifier(&x2apic_cpu_notifier); - return 1; + for_each_online_cpu(cpu) { + if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu)) + continue; + cpumask_clear_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu)); + cpumask_clear_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu)); + } + free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu)); + free_cpumask_var(per_cpu(ipi_mask, this_cpu)); + return 0; } static int x2apic_cluster_probe(void) { - if (x2apic_mode) - return x2apic_init_cpu_notifier(); - else + int cpu = smp_processor_id(); + + if (!x2apic_mode) return 0; + + cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu)); + cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE", + x2apic_prepare_cpu, x2apic_dead_cpu); + return 1; } static const struct cpumask *x2apic_cluster_target_cpus(void) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index ace5ad0fc3ec..78170827a776 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -17,6 +17,7 @@ enum cpuhp_state { CPUHP_WORKQUEUE_PREP, CPUHP_HRTIMERS_PREPARE, CPUHP_PROFILE_PREPARE, + CPUHP_X2APIC_PREPARE, CPUHP_TIMERS_DEAD, CPUHP_NOTIFY_PREPARE, CPUHP_BRINGUP_CPU, -- 2.20.1