Commit 26b87688 authored by Richard Cochran's avatar Richard Cochran Committed by Ingo Molnar
Browse files

arm/twd: Convert to hotplug state machine 



Install the callbacks via the state machine. The callbacks won't be invoked on
already online CPUs.

Signed-off-by: default avatarRichard Cochran <rcochran@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.881124821@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9eeb2264

arch/arm/kernel/smp_twd.c

+11 −20
Original line number Diff line number Diff line
@@ -310,25 +310,18 @@ static void twd_timer_setup(void) 
	enable_percpu_irq(clk->irq, 0);

}



static int twd_timer_cpu_notify(struct notifier_block *self,

				unsigned long action, void *hcpu)

static int twd_timer_starting_cpu(unsigned int cpu)

{

	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_STARTING:

	twd_timer_setup();

		break;

	case CPU_DYING:

		twd_timer_stop();

		break;

	return 0;

}



	return NOTIFY_OK;

static int twd_timer_dying_cpu(unsigned int cpu)

{

	twd_timer_stop();

	return 0;

}



static struct notifier_block twd_timer_cpu_nb = {

	.notifier_call = twd_timer_cpu_notify,

};



static int __init twd_local_timer_common_register(struct device_node *np)

{

	int err;
@@ -345,9 +338,9 @@ static int __init twd_local_timer_common_register(struct device_node *np) 
		goto out_free;

	}



	err = register_cpu_notifier(&twd_timer_cpu_nb);

	if (err)

		goto out_irq;

	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_TWD_STARTING,

				  "AP_ARM_TWD_STARTING",

				  twd_timer_starting_cpu, twd_timer_dying_cpu);



	twd_get_clock(np);

	if (!of_property_read_bool(np, "always-on"))
@@ -365,8 +358,6 @@ static int __init twd_local_timer_common_register(struct device_node *np) 


	return 0;



out_irq:

	free_percpu_irq(twd_ppi, twd_evt);

out_free:

	iounmap(twd_base);

	twd_base = NULL;

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ enum cpuhp_state { 
	CPUHP_AP_ARM_L2X0_STARTING,

	CPUHP_AP_ARM_ARCH_TIMER_STARTING,

	CPUHP_AP_DUMMY_TIMER_STARTING,

	CPUHP_AP_ARM_TWD_STARTING,

	CPUHP_AP_METAG_TIMER_STARTING,

	CPUHP_AP_QCOM_TIMER_STARTING,

	CPUHP_AP_MIPS_GIC_TIMER_STARTING,

CRA Git | Maintained and supported by SUSTech CRA and CCSE