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clocksource/dummy_timer: 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/20160713153336.130385842@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Richard Cochran 2016-07-13 17:16:41 +00:00 committed by Ingo Molnar
parent 7e86e8bd8d
commit 00c1d17aab
2 changed files with 7 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/clocksource/dummy_timer.c
View File

@ -16,10 +16,9 @@
static DEFINE_PER_CPU(struct clock_event_device, dummy_timer_evt);
static void dummy_timer_setup(void)
static int dummy_timer_starting_cpu(unsigned int cpu)
{
int cpu = smp_processor_id();
struct clock_event_device *evt = raw_cpu_ptr(&dummy_timer_evt);
struct clock_event_device *evt = per_cpu_ptr(&dummy_timer_evt, cpu);
evt->name = "dummy_timer";
evt->features = CLOCK_EVT_FEAT_PERIODIC |
@ -29,36 +28,13 @@ static void dummy_timer_setup(void)
evt->cpumask = cpumask_of(cpu);
clockevents_register_device(evt);
return 0;
}
static int dummy_timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING)
dummy_timer_setup();
return NOTIFY_OK;
}
static struct notifier_block dummy_timer_cpu_nb = {
.notifier_call = dummy_timer_cpu_notify,
};
static int __init dummy_timer_register(void)
{
int err = 0;
cpu_notifier_register_begin();
err = __register_cpu_notifier(&dummy_timer_cpu_nb);
if (err)
goto out;
/* We won't get a call on the boot CPU, so register immediately */
if (num_possible_cpus() > 1)
dummy_timer_setup();
out:
cpu_notifier_register_done();
return err;
return cpuhp_setup_state(CPUHP_AP_DUMMY_TIMER_STARTING,
"AP_DUMMY_TIMER_STARTING",
dummy_timer_starting_cpu, NULL);
}
early_initcall(dummy_timer_register);

1
include/linux/cpuhotplug.h
View File

@ -37,6 +37,7 @@ enum cpuhp_state {
CPUHP_AP_ARM_VFP_STARTING,
CPUHP_AP_PERF_ARM_STARTING,
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
CPUHP_AP_DUMMY_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,