clocksource/atlas7: 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>
Cc: Barry Song <baohua@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153338.310333816@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 9 insertions, 32 deletions

diff --git a/drivers/clocksource/timer-atlas7.c b/drivers/clocksource/timer-atlas7.c
index 90f8fbc154a4..4334e0330ada 100644
--- a/drivers/clocksource/timer-atlas7.c
+++ b/drivers/clocksource/timer-atlas7.c
@@ -172,9 +172,9 @@ static struct irqaction sirfsoc_timer1_irq = {
         .handler = sirfsoc_timer_interrupt,
 };
 
-static int sirfsoc_local_timer_setup(struct clock_event_device *ce)
+static int sirfsoc_local_timer_starting_cpu(unsigned int cpu)
 {
-        int cpu = smp_processor_id();
+        struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu);
         struct irqaction *action;
 
         if (cpu == 0)
@@ -203,50 +203,27 @@ static int sirfsoc_local_timer_setup(struct clock_event_device *ce)
         return 0;
 }
 
-static void sirfsoc_local_timer_stop(struct clock_event_device *ce)
+static int sirfsoc_local_timer_dying_cpu(unsigned int cpu)
 {
-        int cpu = smp_processor_id();
-
         sirfsoc_timer_count_disable(1);
 
         if (cpu == 0)
                 remove_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq);
         else
                 remove_irq(sirfsoc_timer1_irq.irq, &sirfsoc_timer1_irq);
+        return 0;
 }
 
-static int sirfsoc_cpu_notify(struct notifier_block *self,
-                              unsigned long action, void *hcpu)
-{
-        /*
-         * Grab cpu pointer in each case to avoid spurious
-         * preemptible warnings
-         */
-        switch (action & ~CPU_TASKS_FROZEN) {
-        case CPU_STARTING:
-                sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
-                break;
-        case CPU_DYING:
-                sirfsoc_local_timer_stop(this_cpu_ptr(sirfsoc_clockevent));
-                break;
-        }
-
-        return NOTIFY_OK;
-}
-
-static struct notifier_block sirfsoc_cpu_nb = {
-        .notifier_call = sirfsoc_cpu_notify,
-};
-
 static int __init sirfsoc_clockevent_init(void)
 {
         sirfsoc_clockevent = alloc_percpu(struct clock_event_device);
         BUG_ON(!sirfsoc_clockevent);
 
-        BUG_ON(register_cpu_notifier(&sirfsoc_cpu_nb));
-
-        /* Immediately configure the timer on the boot CPU */
-        return sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
+        /* Install and invoke hotplug callbacks */
+        return cpuhp_setup_state(CPUHP_AP_MARCO_TIMER_STARTING,
+                                 "AP_MARCO_TIMER_STARTING",
+                                 sirfsoc_local_timer_starting_cpu,
+                                 sirfsoc_local_timer_dying_cpu);
 }
 
 /* initialize the kernel jiffy timer source */