Commit f1e0bb0a authored by Yang Yingliang's avatar Yang Yingliang Committed by Thomas Gleixner

genirq: Introduce generic irq migration for cpu hotunplug

ARM and ARM64 have almost identical code for migrating interrupts on
cpu hotunplug. Provide a generic version which can be used by both.

The new code addresses a shortcoming in the ARM[64] variants which
fails to update the affinity change in some cases. The solution for
this is to use the core function irq_do_set_affinity() instead of open
coding it.

[ tglx: Added copyright notice and license boilerplate. Rewrote
  	subject and changelog. ]
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Acked-by: default avatarRussell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Link: http://lkml.kernel.org/r/1443087135-17044-2-git-send-email-yangyingliang@huawei.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9ffecb10
......@@ -452,6 +452,8 @@ 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);
......
......@@ -30,6 +30,10 @@ config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
config GENERIC_PENDING_IRQ
bool
# Support for generic irq migrating off cpu before the cpu is offline.
config GENERIC_IRQ_MIGRATION
bool
# Alpha specific irq affinity mechanism
config AUTO_IRQ_AFFINITY
bool
......
......@@ -5,5 +5,6 @@ obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
obj-$(CONFIG_GENERIC_IRQ_MIGRATION) += cpuhotplug.o
obj-$(CONFIG_PM_SLEEP) += pm.o
obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o
/*
* Generic cpu hotunplug interrupt migration code copied from the
* arch/arm implementation
*
* Copyright (C) Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/interrupt.h>
#include <linux/ratelimit.h>
#include <linux/irq.h>
#include "internals.h"
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;
/*
* 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;
}
/**
* irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu
*
* 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);
}
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