Add move_irqs() into kernel/irq/migration.c. So we can use it to migrate interrupts, when cpu is offline.
Cc: Jiang Liu <jiang....@linux.intel.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Marc Zyngier <marc.zyng...@arm.com> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Will Deacon <will.dea...@arm.com> Cc: Russell King - ARM Linux <li...@arm.linux.org.uk> Cc: Hanjun Guo <hanjun....@linaro.org> Signed-off-by: Yang Yingliang <yangyingli...@huawei.com> --- include/linux/irq.h | 4 +++ kernel/irq/migration.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index 6f8b340..64e3a02 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { } static inline void irq_move_masked_irq(struct irq_data *data) { } #endif +#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU) +void move_irqs(void); +#endif + extern int no_irq_affinity; #ifdef CONFIG_HARDIRQS_SW_RESEND diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 1ff2b77..75bff60 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -1,6 +1,7 @@ #include <linux/irq.h> #include <linux/interrupt.h> +#include <linux/ratelimit.h> #include "internals.h" @@ -79,3 +80,68 @@ void irq_move_irq(struct irq_data *idata) idata->chip->irq_unmask(idata); } #endif + +#ifdef CONFIG_HOTPLUG_CPU +static bool migrate_one_irq(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + const struct cpumask *affinity = d->affinity; + struct irq_chip *c; + bool ret = false; + + /* + * If this is a per-CPU interrupt, or the affinity does not + * include this CPU, then we have nothing to do. + */ + if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) + return false; + + if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { + affinity = cpu_online_mask; + ret = true; + } + + c = irq_data_get_irq_chip(d); + if (!c->irq_set_affinity) { + pr_warn_ratelimited("IRQ%u: unable to set affinity\n", d->irq); + } else { + int r = irq_do_set_affinity(d, affinity, false); + if (r) + pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", d->irq, r); + } + + return ret; +} + +/* + * The current CPU has been marked offline. Migrate IRQs off this CPU. + * If the affinity settings do not allow other CPUs, force them onto any + * available CPU. + * + * Note: we must iterate over all IRQs, whether they have an attached + * action structure or not, as we need to get chained interrupts too. + */ +void move_irqs(void) +{ + unsigned int irq; + struct irq_desc *desc; + unsigned long flags; + + local_irq_save(flags); + + for_each_active_irq(irq) { + bool affinity_broken; + + desc = irq_to_desc(irq); + raw_spin_lock(&desc->lock); + affinity_broken = migrate_one_irq(desc); + raw_spin_unlock(&desc->lock); + + if (affinity_broken) + pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", + irq, smp_processor_id()); + } + + local_irq_restore(flags); +} +#endif /* CONFIG_HOTPLUG_CPU */ -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/