[patch 44/66] clocksource/atlas7: Convert to hotplug state machine
From: Anna-Maria Gleixner <anna-maria@linutronix.de>
Date: 2016-07-11 12:38:44
From: Richard Cochran <redacted> Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Richard Cochran <redacted> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Barry Song <baohua@kernel.org> Cc: Daniel Lezcano <redacted> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- drivers/clocksource/timer-atlas7.c | 41 ++++++++----------------------------- include/linux/cpuhotplug.h | 1 2 files changed, 10 insertions(+), 32 deletions(-)
--- a/drivers/clocksource/timer-atlas7.c
+++ b/drivers/clocksource/timer-atlas7.c@@ -172,9 +172,9 @@ static struct irqaction sirfsoc_timer1_i .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(str 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 void __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 */ - sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent)); + /* Install and invoke hotplug callbacks */ + 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 */ --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h
@@ -44,6 +44,7 @@ enum cpuhp_state { CPUHP_AP_METAG_TIMER_STARTING, CPUHP_AP_QCOM_TIMER_STARTING, CPUHP_AP_ARMADA_TIMER_STARTING, + CPUHP_AP_MARCO_TIMER_STARTING, CPUHP_AP_KVM_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE,