ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU

#ifdef CONFIG_HOTPLUG_CPU

static bool migrate_one_irq(struct irq_data *d)

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;

		affinity = cpu_online_mask;

		ret = true;

	}

	d->chip->irq_set_affinity(d, affinity, true);

	c = irq_data_get_irq_chip(d);

	if (c->irq_set_affinity)

		c->irq_set_affinity(d, affinity, true);

	else

		pr_debug("IRQ%u: unable to set affinity\n", d->irq);

	return ret;

}

/*

 * The CPU has been marked offline.  Migrate IRQs off this CPU.  If

 * the affinity settings do not allow other CPUs, force them onto any

 * 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 migrate_irqs(void)

{

	unsigned int i, cpu = smp_processor_id();

	unsigned int i;

	struct irq_desc *desc;

	unsigned long flags;

	local_irq_save(flags);

	for_each_irq_desc(i, desc) {

		struct irq_data *d = &desc->irq_data;

		bool affinity_broken = false;

		if (!desc)

			continue;

		raw_spin_lock(&desc->lock);

		if (desc->action != NULL &&

		    cpumask_test_cpu(smp_processor_id(), d->affinity))

			affinity_broken = migrate_one_irq(d);

		affinity_broken = migrate_one_irq(desc);

		raw_spin_unlock(&desc->lock);

		if (affinity_broken && printk_ratelimit())

			pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu);

			pr_warning("IRQ%u no longer affine to CPU%u\n", i,

				smp_processor_id());

	}

	local_irq_restore(flags);