[PATCH v6 19/46] irq: Use get/put_online_cpus_atomic() to prevent CPU offline
From: Srivatsa S. Bhat <hidden>
Date: 2013-02-18 12:43:08
Also in:
linux-arch, linux-arm-kernel, linux-pm, lkml, netdev
Subsystem:
irq subsystem, the rest · Maintainers:
Thomas Gleixner, Linus Torvalds
Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Signed-off-by: Srivatsa S. Bhat <redacted> --- kernel/irq/manage.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e49a288..b4240b9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c@@ -16,6 +16,7 @@ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/cpu.h> #include <linux/task_work.h> #include "internals.h"
@@ -202,7 +203,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask) return -EINVAL; raw_spin_lock_irqsave(&desc->lock, flags); + get_online_cpus_atomic(); ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask); + put_online_cpus_atomic(); raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; }
@@ -343,7 +346,9 @@ int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask) int ret; raw_spin_lock_irqsave(&desc->lock, flags); + get_online_cpus_atomic(); ret = setup_affinity(irq, desc, mask); + put_online_cpus_atomic(); raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; }
@@ -1126,7 +1131,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) } /* Set default affinity mask once everything is setup */ + get_online_cpus_atomic(); setup_affinity(irq, desc, mask); + put_online_cpus_atomic(); } else if (new->flags & IRQF_TRIGGER_MASK) { unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;