Add irq_migrate_all_off_this_cpu() into kernel/irq/migration.c.
So we can use it to migrate interrupts, when cpu is offline.
Cc: Jiang Liu <jiang....@linux.intel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Marc Zyngier <marc.zyng...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Russell King - ARM Linux <li...@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun....@linaro.org>
Signed-off-by: Yang Yingliang <yangyingli...@huawei.com>
---
include/linux/irq.h | 2 ++
kernel/irq/migration.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 66 insertions(+)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 6f8b340..c111fa1 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -438,6 +438,8 @@ extern int irq_set_affinity_locked(struct irq_data *data,
const struct cpumask *cpumask, bool force);
extern int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info);
+extern void irq_migrate_all_off_this_cpu(void);
+
#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_PENDING_IRQ)
void irq_move_irq(struct irq_data *data);
void irq_move_masked_irq(struct irq_data *data);
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 1ff2b77..6e3e38d 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,6 +1,7 @@
#include <linux/irq.h>
#include <linux/interrupt.h>
+#include <linux/ratelimit.h>
#include "internals.h"
@@ -79,3 +80,66 @@ void irq_move_irq(struct irq_data *idata)
idata->chip->irq_unmask(idata);
}
#endif
+
+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;
+ ret = true;
+ }
+
+ c = irq_data_get_irq_chip(d);
+ if (!c->irq_set_affinity) {
+ pr_warn_ratelimited("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);
+ }
+
+ return ret;
+}
+
+/*
+ * 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 irq_migrate_all_off_this_cpu(void)
+{
+ unsigned int irq;
+ struct irq_desc *desc;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ for_each_active_irq(irq) {
+ bool affinity_broken;
+
+ desc = irq_to_desc(irq);
+ raw_spin_lock(&desc->lock);
+ 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",
+ irq, smp_processor_id());
+ }
+
+ local_irq_restore(flags);
+}
--
2.5.0
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