Commit 25ac7761 authored by Daniel Lezcano's avatar Daniel Lezcano Committed by Rafael J. Wysocki
Browse files

ACPI: intel_idle : break dependency between modules 



When the system is booted with some cpus offline, the idle
driver is not initialized. When a cpu is set online, the
acpi code call the intel idle init function. Unfortunately
this code introduce a dependency between intel_idle and acpi.

This patch is intended to remove this dependency by using the
notifier of intel_idle. This patch has the benefit of
encapsulating the intel_idle driver and remove some exported
functions.

Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 6e797a07

drivers/acpi/processor_driver.c

+0 −7
Original line number Diff line number Diff line
@@ -427,18 +427,11 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, 
		 * Initialize missing things

		 */

		if (pr->flags.need_hotplug_init) {

			struct cpuidle_driver *idle_driver =

				cpuidle_get_driver();



			printk(KERN_INFO "Will online and init hotplugged "

			       "CPU: %d\n", pr->id);

			WARN(acpi_processor_start(pr), "Failed to start CPU:"

				" %d\n", pr->id);

			pr->flags.need_hotplug_init = 0;

			if (idle_driver && !strcmp(idle_driver->name,

						   "intel_idle")) {

				intel_idle_cpu_init(pr->id);

			}

		/* Normal CPU soft online event */

		} else {

			acpi_processor_ppc_has_changed(pr, 0);

drivers/idle/intel_idle.c

+27 −14
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ static const struct idle_cpu *icpu; 
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;

static int intel_idle(struct cpuidle_device *dev,

			struct cpuidle_driver *drv, int index);

static int intel_idle_cpu_init(int cpu);



static struct cpuidle_state *cpuidle_state_table;
@@ -302,22 +303,35 @@ static void __setup_broadcast_timer(void *arg) 
	clockevents_notify(reason, &cpu);

}



static int setup_broadcast_cpuhp_notify(struct notifier_block *n,

static int cpu_hotplug_notify(struct notifier_block *n,

			      unsigned long action, void *hcpu)

{

	int hotcpu = (unsigned long)hcpu;

	struct cpuidle_device *dev;



	switch (action & 0xf) {

	case CPU_ONLINE:



		if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)

			smp_call_function_single(hotcpu, __setup_broadcast_timer,

						 (void *)true, 1);



		/*

		 * Some systems can hotplug a cpu at runtime after

		 * the kernel has booted, we have to initialize the

		 * driver in this case

		 */

		dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);

		if (!dev->registered)

			intel_idle_cpu_init(hotcpu);



		break;

	}

	return NOTIFY_OK;

}



static struct notifier_block setup_broadcast_notifier = {

	.notifier_call = setup_broadcast_cpuhp_notify,

static struct notifier_block cpu_hotplug_notifier = {

	.notifier_call = cpu_hotplug_notify,

};



static void auto_demotion_disable(void *dummy)
@@ -405,10 +419,10 @@ static int intel_idle_probe(void) 


	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */

		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;

	else {

	else

		on_each_cpu(__setup_broadcast_timer, (void *)true, 1);

		register_cpu_notifier(&setup_broadcast_notifier);

	}



	register_cpu_notifier(&cpu_hotplug_notifier);



	pr_debug(PREFIX "v" INTEL_IDLE_VERSION

		" model 0x%X\n", boot_cpu_data.x86_model);
@@ -494,7 +508,7 @@ static int intel_idle_cpuidle_driver_init(void) 
 * allocate, initialize, register cpuidle_devices

 * @cpu: cpu/core to initialize

 */

int intel_idle_cpu_init(int cpu)

static int intel_idle_cpu_init(int cpu)

{

	int cstate;

	struct cpuidle_device *dev;
@@ -539,7 +553,6 @@ int intel_idle_cpu_init(int cpu) 


	return 0;

}

EXPORT_SYMBOL_GPL(intel_idle_cpu_init);



static int __init intel_idle_init(void)

{
@@ -581,10 +594,10 @@ static void __exit intel_idle_exit(void) 
	intel_idle_cpuidle_devices_uninit();

	cpuidle_unregister_driver(&intel_idle_driver);



	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) {



	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)

		on_each_cpu(__setup_broadcast_timer, (void *)false, 1);

		unregister_cpu_notifier(&setup_broadcast_notifier);

	}

	unregister_cpu_notifier(&cpu_hotplug_notifier);



	return;

}

include/linux/cpuidle.h

+0 −7
Original line number Diff line number Diff line
@@ -206,14 +206,7 @@ struct cpuidle_governor { 
extern int cpuidle_register_governor(struct cpuidle_governor *gov);

extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);



#ifdef CONFIG_INTEL_IDLE

extern int intel_idle_cpu_init(int cpu);

#else

static inline int intel_idle_cpu_init(int cpu) { return -1; }

#endif



#else

static inline int intel_idle_cpu_init(int cpu) { return -1; }



static inline int cpuidle_register_governor(struct cpuidle_governor *gov)

{return 0;}

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