@@ -131,46 +131,63 @@ int __init arch_probe_nr_irqs(void)
#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);
Our selection of interrupts to consider for IRQ migration is sub- standard. We were potentially including per-CPU interrupts in our migration strategy, but omitting chained interrupts. This caused some interrupts to remain on a downed CPU. We were also trying to migrate interrupts which were not migratable, resulting in an OOPS. Instead, iterate over all interrupts, skipping per-CPU interrupts or interrupts whose affinity does not include the downed CPU, and attempt to set the affinity for every one else if their chip implements irq_set_affinity(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> --- arch/arm/kernel/irq.c | 39 ++++++++++++++++++++++++++++----------- 1 files changed, 28 insertions(+), 11 deletions(-)