irqchip/hip04: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.244546182@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drivers/irqchip/irq-hip04.c

@@ -342,26 +342,12 @@ static int hip04_irq_domain_xlate(struct irq_domain *d,
 	return ret;
 }
 
-#ifdef CONFIG_SMP
-static int hip04_irq_secondary_init(struct notifier_block *nfb,
-				    unsigned long action,
-				    void *hcpu)
+static int hip04_irq_starting_cpu(unsigned int cpu)
 {
-	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
-		hip04_irq_cpu_init(&hip04_data);
-	return NOTIFY_OK;
+	hip04_irq_cpu_init(&hip04_data);
+	return 0;
 }
 
-/*
- * Notifier for enabling the INTC CPU interface. Set an arbitrarily high
- * priority because the GIC needs to be up before the ARM generic timers.
- */
-static struct notifier_block hip04_irq_cpu_notifier = {
-	.notifier_call	= hip04_irq_secondary_init,
-	.priority	= 100,
-};
-#endif
-
 static const struct irq_domain_ops hip04_irq_domain_ops = {
 	.map	= hip04_irq_domain_map,
 	.xlate	= hip04_irq_domain_xlate,
@@ -417,13 +403,12 @@ hip04_of_init(struct device_node *node, struct device_node *parent)
 
 #ifdef CONFIG_SMP
 	set_smp_cross_call(hip04_raise_softirq);
-	register_cpu_notifier(&hip04_irq_cpu_notifier);
 #endif
 	set_handle_irq(hip04_handle_irq);
 
 	hip04_irq_dist_init(&hip04_data);
-	hip04_irq_cpu_init(&hip04_data);
-
+	cpuhp_setup_state(CPUHP_AP_IRQ_HIP04_STARTING, "AP_IRQ_HIP04_STARTING",
+			  hip04_irq_starting_cpu, NULL);
 	return 0;
 }
 IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);

include/linux/cpuhotplug.h

@@ -11,6 +11,7 @@ enum cpuhp_state {
 	CPUHP_AP_SCHED_STARTING,
 	CPUHP_AP_IRQ_GIC_STARTING,
 	CPUHP_AP_IRQ_GICV3_STARTING,
+	CPUHP_AP_IRQ_HIP04_STARTING,
 	CPUHP_AP_NOTIFY_STARTING,
 	CPUHP_AP_ONLINE,
 	CPUHP_TEARDOWN_CPU,