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clocksource/arm_arch_timer: Convert to hotplug state machine

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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/20160713153336.048259040@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Richard Cochran 2016-07-13 17:16:39 +00:00 committed by Ingo Molnar
parent e1272f541c
commit 7e86e8bd8d
2 changed files with 27 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
drivers/clocksource/arm_arch_timer.c
View File

@ -370,8 +370,10 @@ static bool arch_timer_has_nonsecure_ppi(void)
arch_timer_ppi[PHYS_NONSECURE_PPI]);
}
static int arch_timer_setup(struct clock_event_device *clk)
static int arch_timer_starting_cpu(unsigned int cpu)
{
struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
__arch_timer_setup(ARCH_CP15_TIMER, clk);
enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], 0);
@ -527,29 +529,14 @@ static void arch_timer_stop(struct clock_event_device *clk)
clk->set_state_shutdown(clk);
}
static int arch_timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
static int arch_timer_dying_cpu(unsigned int cpu)
{
/*
* Grab cpu pointer in each case to avoid spurious
* preemptible warnings
*/
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
arch_timer_setup(this_cpu_ptr(arch_timer_evt));
break;
case CPU_DYING:
arch_timer_stop(this_cpu_ptr(arch_timer_evt));
break;
}
struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
return NOTIFY_OK;
arch_timer_stop(clk);
return 0;
}
static struct notifier_block arch_timer_cpu_nb = {
.notifier_call = arch_timer_cpu_notify,
};
#ifdef CONFIG_CPU_PM
static unsigned int saved_cntkctl;
static int arch_timer_cpu_pm_notify(struct notifier_block *self,
@ -570,11 +557,21 @@ static int __init arch_timer_cpu_pm_init(void)
{
return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
}
static void __init arch_timer_cpu_pm_deinit(void)
{
WARN_ON(cpu_pm_unregister_notifier(&arch_timer_cpu_pm_notifier));
}
#else
static int __init arch_timer_cpu_pm_init(void)
{
return 0;
}
static void __init arch_timer_cpu_pm_deinit(void)
{
}
#endif
static int __init arch_timer_register(void)
@ -621,22 +618,23 @@ static int __init arch_timer_register(void)
goto out_free;
}
err = register_cpu_notifier(&arch_timer_cpu_nb);
if (err)
goto out_free_irq;
err = arch_timer_cpu_pm_init();
if (err)
goto out_unreg_notify;
/* Immediately configure the timer on the boot CPU */
arch_timer_setup(this_cpu_ptr(arch_timer_evt));
/* Register and immediately configure the timer on the boot CPU */
err = cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_STARTING,
"AP_ARM_ARCH_TIMER_STARTING",
arch_timer_starting_cpu, arch_timer_dying_cpu);
if (err)
goto out_unreg_cpupm;
return 0;
out_unreg_cpupm:
arch_timer_cpu_pm_deinit();
out_unreg_notify:
unregister_cpu_notifier(&arch_timer_cpu_nb);
out_free_irq:
free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt);
if (arch_timer_has_nonsecure_ppi())
free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],

1
include/linux/cpuhotplug.h
View File

@ -36,6 +36,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_XTENSA_STARTING,
CPUHP_AP_ARM_VFP_STARTING,
CPUHP_AP_PERF_ARM_STARTING,
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,