arm64: fix a migrating irq bug when hotplug cpu

When cpu is disabled, all irqs will be migratged to another cpu.
In some cases, a new affinity is different, the old affinity need
to be updated and if irq_set_affinity's return value is IRQ_SET_MASK_OK_DONE,
the old affinity can not be updated. Fix it by using irq_do_set_affinity.

And migrating interrupts is a core code matter, so use the generic
function irq_migrate_all_off_this_cpu() to migrate interrupts in
kernel/irq/migration.c.

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

4 files changed, 3 insertions, 64 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 98b4f98a13de..1b35bdbd5d74 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -427,6 +427,7 @@ config NR_CPUS
 
 config HOTPLUG_CPU
         bool "Support for hot-pluggable CPUs"
+        select GENERIC_IRQ_MIGRATION
         help
           Say Y here to experiment with turning CPUs off and on.  CPUs
           can be controlled through /sys/devices/system/cpu.
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index bbb251b14746..09169296c3cc 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -7,7 +7,6 @@
 
 struct pt_regs;
 
-extern void migrate_irqs(void);
 extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
 
 static inline void acpi_irq_init(void)
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 11dc3fd47853..9f17ec071ee0 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -27,7 +27,6 @@
 #include <linux/init.h>
 #include <linux/irqchip.h>
 #include <linux/seq_file.h>
-#include <linux/ratelimit.h>
 
 unsigned long irq_err_count;
 
@@ -54,64 +53,3 @@ void __init init_IRQ(void)
         if (!handle_arch_irq)
                 panic("No interrupt controller found.");
 }
-
-#ifdef CONFIG_HOTPLUG_CPU
-static bool migrate_one_irq(struct irq_desc *desc)
-{
-        struct irq_data *d = irq_desc_get_irq_data(desc);
-        const struct cpumask *affinity = irq_data_get_affinity_mask(d);
-        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_debug("IRQ%u: unable to set affinity\n", d->irq);
-        else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
-                cpumask_copy(irq_data_get_affinity_mask(d), affinity);
-
-        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 migrate_irqs(void)
-{
-        unsigned int i;
-        struct irq_desc *desc;
-        unsigned long flags;
-
-        local_irq_save(flags);
-
-        for_each_irq_desc(i, desc) {
-                bool affinity_broken;
-
-                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",
-                                            i, smp_processor_id());
-        }
-
-        local_irq_restore(flags);
-}
-#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 03b0aa28ea61..b7a973d6861e 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -231,7 +231,8 @@ int __cpu_disable(void)
         /*
          * OK - migrate IRQs away from this CPU
          */
-        migrate_irqs();
+        irq_migrate_all_off_this_cpu();
+
         return 0;
 }