[patch 41/66] clocksource/metag: Convert to hotplug state machine

From: Anna-Maria Gleixner
Date: Mon Jul 11 2016 - 08:36:07 EST


From: Richard Cochran <rcochran@xxxxxxxxxxxxx>

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>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: linux-metag@xxxxxxxxxxxxxxx
Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
---
drivers/clocksource/metag_generic.c | 33 ++++++---------------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 7 insertions(+), 27 deletions(-)

--- a/drivers/clocksource/metag_generic.c
+++ b/drivers/clocksource/metag_generic.c
@@ -90,7 +90,7 @@ unsigned long long sched_clock(void)
return ticks << HARDWARE_TO_NS_SHIFT;
}

-static void arch_timer_setup(unsigned int cpu)
+static int arch_timer_starting_cpu(unsigned int cpu)
{
unsigned int txdivtime;
struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
@@ -132,27 +132,9 @@ static void arch_timer_setup(unsigned in
val = core_reg_read(TXUCT_ID, TXTIMER_REGNUM, thread0);
__core_reg_set(TXTIMER, val);
}
+ return 0;
}

-static int arch_timer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
-
- switch (action) {
- case CPU_STARTING:
- case CPU_STARTING_FROZEN:
- arch_timer_setup(cpu);
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block arch_timer_cpu_nb = {
- .notifier_call = arch_timer_cpu_notify,
-};
-
int __init metag_generic_timer_init(void)
{
/*
@@ -170,11 +152,8 @@ int __init metag_generic_timer_init(void

setup_irq(tbisig_map(TBID_SIGNUM_TRT), &metag_timer_irq);

- /* Configure timer on boot CPU */
- arch_timer_setup(smp_processor_id());
-
- /* Hook cpu boot to configure other CPU's timers */
- register_cpu_notifier(&arch_timer_cpu_nb);
-
- return 0;
+ /* Hook cpu boot to configure the CPU's timers */
+ return cpuhp_setup_state(CPUHP_AP_METAG_TIMER_STARTING,
+ "AP_METAG_TIMER_STARTING",
+ arch_timer_starting_cpu, NULL);
}
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -41,6 +41,7 @@ enum cpuhp_state {
CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
CPUHP_AP_DUMMY_TIMER_STARTING,
CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
+ CPUHP_AP_METAG_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,