clocksource/armada-370-xp: 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/20160713153338.229913786@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
index 20ec066481fe2bcddd05518c851b6c43bdc5f2b8..719b478d136e7dbc8be409847c786a17df4cd971 100644 (file)
--- a/drivers/clocksource/time-armada-370-xp.c
+++ b/drivers/clocksource/time-armada-370-xp.c
@@ -170,10 +170,10 @@ static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
 /*
  * Setup the local clock events for a CPU.
  */
-static int armada_370_xp_timer_setup(struct clock_event_device *evt)
+static int armada_370_xp_timer_starting_cpu(unsigned int cpu)
 {
+       struct clock_event_device *evt = per_cpu_ptr(armada_370_xp_evt, cpu);
        u32 clr = 0, set = 0;
-       int cpu = smp_processor_id();
 
        if (timer25Mhz)
                set = TIMER0_25MHZ;
@@ -200,35 +200,15 @@ static int armada_370_xp_timer_setup(struct clock_event_device *evt)
        return 0;
 }
 
-static void armada_370_xp_timer_stop(struct clock_event_device *evt)
+static int armada_370_xp_timer_dying_cpu(unsigned int cpu)
 {
+       struct clock_event_device *evt = per_cpu_ptr(armada_370_xp_evt, cpu);
+
        evt->set_state_shutdown(evt);
        disable_percpu_irq(evt->irq);
+       return 0;
 }
 
-static int armada_370_xp_timer_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:
-               armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
-               break;
-       case CPU_DYING:
-               armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt));
-               break;
-       }
-
-       return NOTIFY_OK;
-}
-
-static struct notifier_block armada_370_xp_timer_cpu_nb = {
-       .notifier_call = armada_370_xp_timer_cpu_notify,
-};
-
 static u32 timer0_ctrl_reg, timer0_local_ctrl_reg;
 
 static int armada_370_xp_timer_suspend(void)
@@ -322,8 +302,6 @@ static int __init armada_370_xp_timer_common_init(struct device_node *np)
                return res;
        }
 
-       register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
-
        armada_370_xp_evt = alloc_percpu(struct clock_event_device);
        if (!armada_370_xp_evt)
                return -ENOMEM;
@@ -341,9 +319,12 @@ static int __init armada_370_xp_timer_common_init(struct device_node *np)
                return res;
        }
 
-       res = armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+       res = cpuhp_setup_state(CPUHP_AP_ARMADA_TIMER_STARTING,
+                               "AP_ARMADA_TIMER_STARTING",
+                               armada_370_xp_timer_starting_cpu,
+                               armada_370_xp_timer_dying_cpu);
        if (res) {
-               pr_err("Failed to setup timer");
+               pr_err("Failed to setup hotplug state and timer");
                return res;
        }
 

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 7ad8a7e7806d6d0165f3e684c16e9df96b7c8306..ee7f750b16332037917a82927d977d4f66c4a5c9 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -53,6 +53,7 @@ enum cpuhp_state {
        CPUHP_AP_ARM_TWD_STARTING,
        CPUHP_AP_METAG_TIMER_STARTING,
        CPUHP_AP_QCOM_TIMER_STARTING,
+       CPUHP_AP_ARMADA_TIMER_STARTING,
        CPUHP_AP_MIPS_GIC_TIMER_STARTING,
        CPUHP_AP_KVM_STARTING,
        CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,