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: Daniel Lezcano daniel.lezcano@linaro.org --- drivers/acpi/processor_driver.c | 7 ------ drivers/idle/intel_idle.c | 41 +++++++++++++++++++++++++------------- include/linux/cpuidle.h | 7 ------ 3 files changed, 27 insertions(+), 28 deletions(-)
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 0734086..8648b29 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -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); diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index d0f59c3..fe95d54 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -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, - unsigned long action, void *hcpu) +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: - smp_call_function_single(hotcpu, __setup_broadcast_timer, - (void *)true, 1); + + 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; } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 5ab7183..66d7e0d 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -213,14 +213,7 @@ 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;}