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>

2 files changed, 10 insertions, 17 deletions

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 8dec2a236af3..2ca7b34871e0 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 836f7db4e548..2be55692aa43 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);