ARC/time: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153338.391826254@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 98f22d2..f927b8d 100644 (file)
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -296,30 +296,23 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
-static int arc_timer_cpu_notify(struct notifier_block *self,
-                               unsigned long action, void *hcpu)
+
+static int arc_timer_starting_cpu(unsigned int cpu)
 {
        struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
 
        evt->cpumask = cpumask_of(smp_processor_id());
 
-       switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_STARTING:
-               clockevents_config_and_register(evt, arc_timer_freq,
-                                               0, ULONG_MAX);
-               enable_percpu_irq(arc_timer_irq, 0);
-               break;
-       case CPU_DYING:
-               disable_percpu_irq(arc_timer_irq);
-               break;
-       }
-
-       return NOTIFY_OK;
+       clockevents_config_and_register(evt, arc_timer_freq, 0, ARC_TIMER_MAX);
+       enable_percpu_irq(arc_timer_irq, 0);
+       return 0;
 }
 
-static struct notifier_block arc_timer_cpu_nb = {
-       .notifier_call = arc_timer_cpu_notify,
-};
+static int arc_timer_dying_cpu(unsigned int cpu)
+{
+       disable_percpu_irq(arc_timer_irq);
+       return 0;
+}
 
 /*
  * clockevent setup for boot CPU
@@ -329,12 +322,6 @@ static int __init arc_clockevent_setup(struct device_node *node)
        struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
        int ret;
 
-       ret = register_cpu_notifier(&arc_timer_cpu_nb);
-       if (ret) {
-               pr_err("Failed to register cpu notifier");
-               return ret;
-       }
-
        arc_timer_irq = irq_of_parse_and_map(node, 0);
        if (arc_timer_irq <= 0) {
                pr_err("clockevent: missing irq");
@@ -347,11 +334,6 @@ static int __init arc_clockevent_setup(struct device_node *node)
                return ret;
        }
 
-       evt->irq = arc_timer_irq;
-       evt->cpumask = cpumask_of(smp_processor_id());
-       clockevents_config_and_register(evt, arc_timer_freq,
-                                       0, ARC_TIMER_MAX);
-
        /* Needs apriori irq_set_percpu_devid() done in intc map function */
        ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
                                 "Timer0 (per-cpu-tick)", evt);
@@ -360,8 +342,14 @@ static int __init arc_clockevent_setup(struct device_node *node)
                return ret;
        }
 
-       enable_percpu_irq(arc_timer_irq, 0);
-
+       ret = cpuhp_setup_state(CPUHP_AP_ARC_TIMER_STARTING,
+                               "AP_ARC_TIMER_STARTING",
+                               arc_timer_starting_cpu,
+                               arc_timer_dying_cpu);
+       if (ret) {
+               pr_err("Failed to setup hotplug state");
+               return ret;
+       }
        return 0;
 }
 

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 5ac59f7..09ef54b 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -56,6 +56,7 @@ enum cpuhp_state {
        CPUHP_AP_ARMADA_TIMER_STARTING,
        CPUHP_AP_MARCO_TIMER_STARTING,
        CPUHP_AP_MIPS_GIC_TIMER_STARTING,
+       CPUHP_AP_ARC_TIMER_STARTING,
        CPUHP_AP_KVM_STARTING,
        CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
        CPUHP_AP_KVM_ARM_VGIC_STARTING,