From fb1013a01673acf7e94e38cda169828ac76b345a Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 29 Nov 2016 10:51:43 +0100 Subject: intel_idle: Convert to hotplug state machine Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. The two smp_call_function_single() invocations in intel_idle_cpu_init() have been removed because intel_idle_cpu_init() is now invoked via the hotplug callback which runs on the target CPU. The IRQ-off calling convention for auto_demotion_disable() and c1e_promotion_disable() has not been preserved because only those two modify the MSR during CPU intialization. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Jacob Pan Signed-off-by: Rafael J. Wysocki --- drivers/idle/intel_idle.c | 103 ++++++++++++++++++---------------------------- 1 file changed, 39 insertions(+), 64 deletions(-) (limited to 'drivers/idle') diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 3828babfb77b..7d8ea3d5fda6 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -98,8 +98,6 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); static void intel_idle_freeze(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; /* @@ -951,50 +949,15 @@ static void intel_idle_freeze(struct cpuidle_device *dev, mwait_idle_with_hints(eax, ecx); } -static void __setup_broadcast_timer(void *arg) +static void __setup_broadcast_timer(bool on) { - unsigned long on = (unsigned long)arg; - if (on) tick_broadcast_enable(); else tick_broadcast_disable(); } -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 & ~CPU_TASKS_FROZEN) { - case CPU_ONLINE: - - if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) - __setup_broadcast_timer((void *)true); - - /* - * 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) - break; - - if (intel_idle_cpu_init(hotcpu)) - return NOTIFY_BAD; - - break; - } - return NOTIFY_OK; -} - -static struct notifier_block cpu_hotplug_notifier = { - .notifier_call = cpu_hotplug_notify, -}; - -static void auto_demotion_disable(void *dummy) +static void auto_demotion_disable(void) { unsigned long long msr_bits; @@ -1002,7 +965,7 @@ static void auto_demotion_disable(void *dummy) msr_bits &= ~(icpu->auto_demotion_disable_flags); wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); } -static void c1e_promotion_disable(void *dummy) +static void c1e_promotion_disable(void) { unsigned long long msr_bits; @@ -1422,12 +1385,11 @@ static void __init intel_idle_cpuidle_driver_init(void) * allocate, initialize, register cpuidle_devices * @cpu: cpu/core to initialize */ -static int intel_idle_cpu_init(int cpu) +static int intel_idle_cpu_init(unsigned int cpu) { struct cpuidle_device *dev; dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu); - dev->cpu = cpu; if (cpuidle_register_device(dev)) { @@ -1436,17 +1398,36 @@ static int intel_idle_cpu_init(int cpu) } if (icpu->auto_demotion_disable_flags) - smp_call_function_single(cpu, auto_demotion_disable, NULL, 1); + auto_demotion_disable(); if (icpu->disable_promotion_to_c1e) - smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1); + c1e_promotion_disable(); + + return 0; +} + +static int intel_idle_cpu_online(unsigned int cpu) +{ + struct cpuidle_device *dev; + + if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) + __setup_broadcast_timer(true); + + /* + * 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, cpu); + if (!dev->registered) + return intel_idle_cpu_init(cpu); return 0; } static int __init intel_idle_init(void) { - int retval, i; + int retval; /* Do not load intel_idle at all for now if idle= is passed */ if (boot_option_idle_override != IDLE_NO_OVERRIDE) @@ -1466,35 +1447,29 @@ static int __init intel_idle_init(void) struct cpuidle_driver *drv = cpuidle_get_driver(); printk(KERN_DEBUG PREFIX "intel_idle yielding to %s", drv ? drv->name : "none"); - free_percpu(intel_idle_cpuidle_devices); - return retval; + goto init_driver_fail; } - cpu_notifier_register_begin(); - - for_each_online_cpu(i) { - retval = intel_idle_cpu_init(i); - if (retval) { - intel_idle_cpuidle_devices_uninit(); - cpu_notifier_register_done(); - cpuidle_unregister_driver(&intel_idle_driver); - free_percpu(intel_idle_cpuidle_devices); - return retval; - } - } - __register_cpu_notifier(&cpu_hotplug_notifier); - if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */ lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE; - else - on_each_cpu(__setup_broadcast_timer, (void *)true, 1); - cpu_notifier_register_done(); + retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online", + intel_idle_cpu_online, NULL); + if (retval < 0) + goto hp_setup_fail; pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n", lapic_timer_reliable_states); return 0; + +hp_setup_fail: + intel_idle_cpuidle_devices_uninit(); + cpuidle_unregister_driver(&intel_idle_driver); +init_driver_fail: + free_percpu(intel_idle_cpuidle_devices); + return retval; + } device_initcall(intel_idle_init); -- cgit v1.2.3