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-rw-r--r--kernel/irq/cpuhotplug.c150
1 files changed, 126 insertions, 24 deletions
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index 011f8c4c63da..aee8f7ec40af 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -14,37 +14,99 @@
#include "internals.h"
+/* For !GENERIC_IRQ_EFFECTIVE_AFF_MASK this looks at general affinity mask */
+static inline bool irq_needs_fixup(struct irq_data *d)
+{
+ const struct cpumask *m = irq_data_get_effective_affinity_mask(d);
+
+ return cpumask_test_cpu(smp_processor_id(), m);
+}
+
static bool migrate_one_irq(struct irq_desc *desc)
{
struct irq_data *d = irq_desc_get_irq_data(desc);
- const struct cpumask *affinity = d->common->affinity;
- struct irq_chip *c;
- bool ret = false;
+ struct irq_chip *chip = irq_data_get_irq_chip(d);
+ bool maskchip = !irq_can_move_pcntxt(d) && !irqd_irq_masked(d);
+ const struct cpumask *affinity;
+ bool brokeaff = false;
+ int err;
/*
- * If this is a per-CPU interrupt, or the affinity does not
- * include this CPU, then we have nothing to do.
+ * IRQ chip might be already torn down, but the irq descriptor is
+ * still in the radix tree. Also if the chip has no affinity setter,
+ * nothing can be done here.
*/
- if (irqd_is_per_cpu(d) ||
- !cpumask_test_cpu(smp_processor_id(), affinity))
+ if (!chip || !chip->irq_set_affinity) {
+ pr_debug("IRQ %u: Unable to migrate away\n", d->irq);
return false;
+ }
+
+ /*
+ * No move required, if:
+ * - Interrupt is per cpu
+ * - Interrupt is not started
+ * - Affinity mask does not include this CPU.
+ *
+ * Note: Do not check desc->action as this might be a chained
+ * interrupt.
+ */
+ if (irqd_is_per_cpu(d) || !irqd_is_started(d) || !irq_needs_fixup(d)) {
+ /*
+ * If an irq move is pending, abort it if the dying CPU is
+ * the sole target.
+ */
+ irq_fixup_move_pending(desc, false);
+ return false;
+ }
+
+ /*
+ * Complete an eventually pending irq move cleanup. If this
+ * interrupt was moved in hard irq context, then the vectors need
+ * to be cleaned up. It can't wait until this interrupt actually
+ * happens and this CPU was involved.
+ */
+ irq_force_complete_move(desc);
+
+ /*
+ * If there is a setaffinity pending, then try to reuse the pending
+ * mask, so the last change of the affinity does not get lost. If
+ * there is no move pending or the pending mask does not contain
+ * any online CPU, use the current affinity mask.
+ */
+ if (irq_fixup_move_pending(desc, true))
+ affinity = irq_desc_get_pending_mask(desc);
+ else
+ affinity = irq_data_get_affinity_mask(d);
+
+ /* Mask the chip for interrupts which cannot move in process context */
+ if (maskchip && chip->irq_mask)
+ chip->irq_mask(d);
if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+ /*
+ * If the interrupt is managed, then shut it down and leave
+ * the affinity untouched.
+ */
+ if (irqd_affinity_is_managed(d)) {
+ irqd_set_managed_shutdown(d);
+ irq_shutdown(desc);
+ return false;
+ }
affinity = cpu_online_mask;
- ret = true;
+ brokeaff = true;
}
- c = irq_data_get_irq_chip(d);
- if (!c->irq_set_affinity) {
- pr_debug("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);
+ err = irq_do_set_affinity(d, affinity, true);
+ if (err) {
+ pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
+ d->irq, err);
+ brokeaff = false;
}
- return ret;
+ if (maskchip && chip->irq_unmask)
+ chip->irq_unmask(d);
+
+ return brokeaff;
}
/**
@@ -59,11 +121,8 @@ static bool migrate_one_irq(struct irq_desc *desc)
*/
void irq_migrate_all_off_this_cpu(void)
{
- unsigned int irq;
struct irq_desc *desc;
- unsigned long flags;
-
- local_irq_save(flags);
+ unsigned int irq;
for_each_active_irq(irq) {
bool affinity_broken;
@@ -73,10 +132,53 @@ void irq_migrate_all_off_this_cpu(void)
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",
+ if (affinity_broken) {
+ pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n",
irq, smp_processor_id());
+ }
+ }
+}
+
+static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu)
+{
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ const struct cpumask *affinity = irq_data_get_affinity_mask(data);
+
+ if (!irqd_affinity_is_managed(data) || !desc->action ||
+ !irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity))
+ return;
+
+ if (irqd_is_managed_and_shutdown(data)) {
+ irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
+ return;
+ }
+
+ /*
+ * If the interrupt can only be directed to a single target
+ * CPU then it is already assigned to a CPU in the affinity
+ * mask. No point in trying to move it around.
+ */
+ if (!irqd_is_single_target(data))
+ irq_set_affinity_locked(data, affinity, false);
+}
+
+/**
+ * irq_affinity_online_cpu - Restore affinity for managed interrupts
+ * @cpu: Upcoming CPU for which interrupts should be restored
+ */
+int irq_affinity_online_cpu(unsigned int cpu)
+{
+ struct irq_desc *desc;
+ unsigned int irq;
+
+ irq_lock_sparse();
+ for_each_active_irq(irq) {
+ desc = irq_to_desc(irq);
+ raw_spin_lock_irq(&desc->lock);
+ irq_restore_affinity_of_irq(desc, cpu);
+ raw_spin_unlock_irq(&desc->lock);
}
+ irq_unlock_sparse();
- local_irq_restore(flags);
+ return 0;
}