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Commit 48d7f6c7 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Ingo Molnar
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x86/hpet: 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: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.279718463@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 7ee681b2

arch/x86/kernel/hpet.c

+34 −35
Original line number Diff line number Diff line
@@ -710,31 +710,29 @@ static void hpet_work(struct work_struct *w) 
	complete(&hpet_work->complete);

}



static int hpet_cpuhp_notify(struct notifier_block *n,

		unsigned long action, void *hcpu)

static int hpet_cpuhp_online(unsigned int cpu)

{

	unsigned long cpu = (unsigned long)hcpu;

	struct hpet_work_struct work;

	struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_ONLINE:

	INIT_DELAYED_WORK_ONSTACK(&work.work, hpet_work);

	init_completion(&work.complete);

	/* FIXME: add schedule_work_on() */

	schedule_delayed_work_on(cpu, &work.work, 0);

	wait_for_completion(&work.complete);

	destroy_delayed_work_on_stack(&work.work);

		break;

	case CPU_DEAD:

		if (hdev) {

	return 0;

}



static int hpet_cpuhp_dead(unsigned int cpu)

{

	struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);



	if (!hdev)

		return 0;

	free_irq(hdev->irq, hdev);

	hdev->flags &= ~HPET_DEV_USED;

	per_cpu(cpu_hpet_dev, cpu) = NULL;

		}

		break;

	}

	return NOTIFY_OK;

	return 0;

}

#else
@@ -750,11 +748,8 @@ static void hpet_reserve_msi_timers(struct hpet_data *hd) 
}

#endif



static int hpet_cpuhp_notify(struct notifier_block *n,

		unsigned long action, void *hcpu)

{

	return NOTIFY_OK;

}

#define hpet_cpuhp_online	NULL

#define hpet_cpuhp_dead		NULL



#endif
@@ -931,7 +926,7 @@ int __init hpet_enable(void) 
 */

static __init int hpet_late_init(void)

{

	int cpu;

	int ret;



	if (boot_hpet_disable)

		return -ENODEV;
@@ -961,16 +956,20 @@ static __init int hpet_late_init(void) 
	if (boot_cpu_has(X86_FEATURE_ARAT))

		return 0;



	cpu_notifier_register_begin();

	for_each_online_cpu(cpu) {

		hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);

	}



	/* This notifier should be called after workqueue is ready */

	__hotcpu_notifier(hpet_cpuhp_notify, -20);

	cpu_notifier_register_done();



	ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "AP_X86_HPET_ONLINE",

				hpet_cpuhp_online, NULL);

	if (ret)

		return ret;

	ret = cpuhp_setup_state(CPUHP_X86_HPET_DEAD, "X86_HPET_DEAD", NULL,

				hpet_cpuhp_dead);

	if (ret)

		goto err_cpuhp;

	return 0;



err_cpuhp:

	cpuhp_remove_state(CPUHP_AP_X86_HPET_ONLINE);

	return ret;

}

fs_initcall(hpet_late_init);

include/linux/cpuhotplug.h

+2 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ enum cpuhp_state { 
	CPUHP_PERF_BFIN,

	CPUHP_PERF_POWER,

	CPUHP_PERF_SUPERH,

	CPUHP_X86_HPET_DEAD,

	CPUHP_WORKQUEUE_PREP,

	CPUHP_NOTIFY_PREPARE,

	CPUHP_BRINGUP_CPU,
@@ -54,6 +55,7 @@ enum cpuhp_state { 
	CPUHP_AP_NOTIFY_ONLINE,

	CPUHP_AP_ONLINE_DYN,

	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,

	CPUHP_AP_X86_HPET_ONLINE,

	CPUHP_AP_ACTIVE,

	CPUHP_ONLINE,

};