ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU
Squash following three patches since the patch with 2ef7570 commit
prevents the MSM platforms from booting, which gets solved in the
next commit ca15af1, but adds build failure; which gets solved in the
final commit 78359cb.
commit 2ef75701d1711a1feee2a82b42a2597ddc05f88b
Author: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu Jul 21 14:51:13 2011 +0100
ARM: CPU hotplug: fix abuse of irqdesc->node
irqdesc's node member is supposed to mark the numa node number for the
interrupt. Our use of it is non-standard. Remove this, replacing the
functionality with a test of the affinity mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
commit ca15af19ac07908c8ca386f6d944a18aa343b868
Author: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu Jul 21 15:07:56 2011 +0100
ARM: CPU hotplug: pass in proper affinity mask on IRQ migration
Now that the GIC takes care of selecting a target interrupt from the
affinity mask, we don't need all this complexity in the core code
anymore. Just detect when we need to break affinity.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
commit 78359cb86b8c4c8946f6732eac2757fa5e1d4de4
Author: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu Jul 21 15:14:21 2011 +0100
ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU
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>
Change-Id: I1559f4f9b2aa52ce026505c7e4d5e7cf9bd102af
Signed-off-by: Ravi Kumar <kumarrav@codeaurora.org>
[tsoni@codeaurora.org: squash the commits to avoid boot & build failures]
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 4ef97a0..5bd484f 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -144,54 +144,63 @@
#ifdef CONFIG_HOTPLUG_CPU
-static bool migrate_one_irq(struct irq_data *d)
+static bool migrate_one_irq(struct irq_desc *desc)
{
- unsigned int cpu = cpumask_any_and(d->affinity, cpu_online_mask);
+ struct irq_data *d = irq_desc_get_irq_data(desc);
+ const struct cpumask *affinity = d->affinity;
+ struct irq_chip *c;
bool ret = false;
- if (cpu >= nr_cpu_ids) {
- cpu = cpumask_any(cpu_online_mask);
+ /*
+ * 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;
}
- pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", d->irq, d->node, cpu);
-
- d->chip->irq_set_affinity(d, cpumask_of(cpu), 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);
- do {
- if (desc->action == NULL)
- break;
-
- if (d->node != cpu)
- break;
-
- affinity_broken = migrate_one_irq(d);
- } while (0);
+ 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);