clocksource/mips-gic: 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: 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/20160713153336.380737946@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 14 insertions, 25 deletions

diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 1572c7a778ab..d91e8725917c 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -49,10 +49,9 @@ struct irqaction gic_compare_irqaction = {
         .name = "timer",
 };
 
-static void gic_clockevent_cpu_init(struct clock_event_device *cd)
+static void gic_clockevent_cpu_init(unsigned int cpu,
+                                    struct clock_event_device *cd)
 {
-        unsigned int cpu = smp_processor_id();
-
         cd->name                = "MIPS GIC";
         cd->features            = CLOCK_EVT_FEAT_ONESHOT |
                                   CLOCK_EVT_FEAT_C3STOP;
@@ -79,19 +78,10 @@ static void gic_update_frequency(void *data)
         clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate);
 }
 
-static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action,
-                                void *data)
+static int gic_starting_cpu(unsigned int cpu)
 {
-        switch (action & ~CPU_TASKS_FROZEN) {
-        case CPU_STARTING:
-                gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device));
-                break;
-        case CPU_DYING:
-                gic_clockevent_cpu_exit(this_cpu_ptr(&gic_clockevent_device));
-                break;
-        }
-
-        return NOTIFY_OK;
+        gic_clockevent_cpu_init(cpu, this_cpu_ptr(&gic_clockevent_device));
+        return 0;
 }
 
 static int gic_clk_notifier(struct notifier_block *nb, unsigned long action,
@@ -105,10 +95,11 @@ static int gic_clk_notifier(struct notifier_block *nb, unsigned long action,
         return NOTIFY_OK;
 }
 
-
-static struct notifier_block gic_cpu_nb = {
-        .notifier_call = gic_cpu_notifier,
-};
+static int gic_dying_cpu(unsigned int cpu)
+{
+        gic_clockevent_cpu_exit(this_cpu_ptr(&gic_clockevent_device));
+        return 0;
+}
 
 static struct notifier_block gic_clk_nb = {
         .notifier_call = gic_clk_notifier,
@@ -125,12 +116,9 @@ static int gic_clockevent_init(void)
         if (ret < 0)
                 return ret;
 
-        ret = register_cpu_notifier(&gic_cpu_nb);
-        if (ret < 0)
-                pr_warn("GIC: Unable to register CPU notifier\n");
-
-        gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device));
-
+        cpuhp_setup_state(CPUHP_AP_MIPS_GIC_TIMER_STARTING,
+                          "AP_MIPS_GIC_TIMER_STARTING", gic_starting_cpu,
+                          gic_dying_cpu);
         return 0;
 }
 
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index d74d15a028e4..456e3d93272c 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -40,6 +40,7 @@ enum cpuhp_state {
         CPUHP_AP_DUMMY_TIMER_STARTING,
         CPUHP_AP_METAG_TIMER_STARTING,
         CPUHP_AP_QCOM_TIMER_STARTING,
+        CPUHP_AP_MIPS_GIC_TIMER_STARTING,
         CPUHP_AP_KVM_STARTING,
         CPUHP_AP_NOTIFY_STARTING,
         CPUHP_AP_ONLINE,