[tip:smp/hotplug] lib/irq_poll: Convert to hotplug state machine

tip-bot for Sebastian Andrzej Siewior
2016-09-19T19:55:37Z

Commit-ID: 75e12ed65312a56401f3b286ac7e12994301371c
Gitweb: http://git.kernel.org/tip/75e12ed65312a56401f3b286ac7e12994301371c
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Tue, 6 Sep 2016 19:04:43 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 19 Sep 2016 21:44:27 +0200

lib/irq_poll: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-8-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
include/linux/cpuhotplug.h | 1 +
lib/irq_poll.c | 26 +++++++++-----------------
2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 8dec2a2..2ca7b34 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -22,6 +22,7 @@ enum cpuhp_state {
CPUHP_CPUIDLE_DEAD,
CPUHP_ARM64_FPSIMD_DEAD,
CPUHP_ARM_OMAP_WAKE_DEAD,
+ CPUHP_IRQ_POLL_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 836f7db..2be5569 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -184,30 +184,21 @@ void irq_poll_init(struct irq_poll *iop, int weight, irq_poll_fn *poll_fn)
}
EXPORT_SYMBOL(irq_poll_init);

-static int irq_poll_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
+static int irq_poll_cpu_dead(unsigned int cpu)
{
/*
* If a CPU goes away, splice its entries to the current CPU
* and trigger a run of the softirq
*/
- if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
- int cpu = (unsigned long) hcpu;
-
- local_irq_disable();
- list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
- this_cpu_ptr(&blk_cpu_iopoll));
- __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
- local_irq_enable();
- }
+ local_irq_disable();
+ list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
+ this_cpu_ptr(&blk_cpu_iopoll));
+ __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+ local_irq_enable();

- return NOTIFY_OK;
+ return 0;
}

-static struct notifier_block irq_poll_cpu_notifier = {
- .notifier_call = irq_poll_cpu_notify,
-};
-
static __init int irq_poll_setup(void)
{
int i;
@@ -216,7 +207,8 @@ static __init int irq_poll_setup(void)
INIT_LIST_HEAD(&per_cpu(blk_cpu_iopoll, i));

open_softirq(IRQ_POLL_SOFTIRQ, irq_poll_softirq);
- register_hotcpu_notifier(&irq_poll_cpu_notifier);
+ cpuhp_setup_state_nocalls(CPUHP_IRQ_POLL_DEAD, "irq_poll:dead", NULL,
+ irq_poll_cpu_dead);
return 0;
}
subsys_initcall(irq_poll_setup);