From 49b424fedaf88d0fa9913082b8c1ccd012a8a972 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Thu, 17 Oct 2013 02:42:28 +0400 Subject: xtensa: implement CPU hotplug Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/irq.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'arch/xtensa/kernel/irq.c') diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c index fad9e0059765..482868a2de6e 100644 --- a/arch/xtensa/kernel/irq.c +++ b/arch/xtensa/kernel/irq.c @@ -153,3 +153,52 @@ void __init init_IRQ(void) #endif variant_init_irq(); } + +#ifdef CONFIG_HOTPLUG_CPU +static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) +{ + struct irq_desc *desc = irq_to_desc(irq); + struct irq_chip *chip = irq_data_get_irq_chip(data); + unsigned long flags; + + raw_spin_lock_irqsave(&desc->lock, flags); + if (chip->irq_set_affinity) + chip->irq_set_affinity(data, cpumask_of(cpu), false); + raw_spin_unlock_irqrestore(&desc->lock, flags); +} + +/* + * The 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. + */ +void migrate_irqs(void) +{ + unsigned int i, cpu = smp_processor_id(); + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_data *data = irq_desc_get_irq_data(desc); + unsigned int newcpu; + + if (irqd_is_per_cpu(data)) + continue; + + if (!cpumask_test_cpu(cpu, data->affinity)) + continue; + + newcpu = cpumask_any_and(data->affinity, cpu_online_mask); + + if (newcpu >= nr_cpu_ids) { + pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", + i, cpu); + + cpumask_setall(data->affinity); + newcpu = cpumask_any_and(data->affinity, + cpu_online_mask); + } + + route_irq(data, i, newcpu); + } +} +#endif /* CONFIG_HOTPLUG_CPU */ -- cgit