Commit-ID: 00c1d17aab513d3b8117fb84644eba39434b33e4
Gitweb: http://git.kernel.org/tip/00c1d17aab513d3b8117fb84644eba39434b33e4
Author: Richard Cochran <rcochran@xxxxxxxxxxxxx>
AuthorDate: Wed, 13 Jul 2016 17:16:41 +0000
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 15 Jul 2016 10:40:24 +0200
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@xxxxxxxxxxxxx>
Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: rt@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160713153336.130385842@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/clocksource/dummy_timer.c | 36 ++++++------------------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 7 insertions(+), 30 deletions(-)
diff --git a/drivers/clocksource/dummy_timer.c b/drivers/clocksource/dummy_timer.c
index 776b6c8..89f1c2e 100644
--- a/drivers/clocksource/dummy_timer.c
+++ b/drivers/clocksource/dummy_timer.c
@@ -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);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f0524cd..8103561 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -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,
--
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