From dc7fd275ae60ef8edf952aff2a62462f5d892fd4 Mon Sep 17 00:00:00 2001 From: ShuoX Liu Date: Tue, 3 Jul 2012 19:05:31 +0200 Subject: cpuidle: move field disable from per-driver to per-cpu Andrew J.Schorr raises a question. When he changes the disable setting on a single CPU, it affects all the other CPUs. Basically, currently, the disable field is per-driver instead of per-cpu. All the C states of the same driver are shared by all CPU in the same machine. The patch changes the `disable' field to per-cpu, so we could set this separately for each cpu. Signed-off-by: ShuoX Liu Reported-by: Andrew J.Schorr Reviewed-by: Yanmin Zhang Signed-off-by: Andrew Morton Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 6c26a3da0e03..8570012a535a 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -34,6 +34,7 @@ struct cpuidle_driver; struct cpuidle_state_usage { void *driver_data; + unsigned long long disable; unsigned long long usage; unsigned long long time; /* in US */ }; @@ -46,7 +47,6 @@ struct cpuidle_state { unsigned int exit_latency; /* in US */ int power_usage; /* in mW */ unsigned int target_residency; /* in US */ - unsigned int disable; int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, -- cgit v1.2.3 From 6e797a078824b30afbfae6cc4b1c2b21c51761ef Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 16 Jun 2012 15:20:11 +0200 Subject: PM / cpuidle: Add driver reference counter Add a reference counter for the cpuidle driver, so that it can't be unregistered when it is in use. Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/driver.c | 29 ++++++++++++++++++++++++++++- include/linux/cpuidle.h | 6 +++++- 2 files changed, 33 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 40cd3f3024df..58bf3b1ac9c4 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -16,6 +16,7 @@ static struct cpuidle_driver *cpuidle_curr_driver; DEFINE_SPINLOCK(cpuidle_driver_lock); +int cpuidle_driver_refcount; static void __cpuidle_register_driver(struct cpuidle_driver *drv) { @@ -89,8 +90,34 @@ void cpuidle_unregister_driver(struct cpuidle_driver *drv) } spin_lock(&cpuidle_driver_lock); - cpuidle_curr_driver = NULL; + + if (!WARN_ON(cpuidle_driver_refcount > 0)) + cpuidle_curr_driver = NULL; + spin_unlock(&cpuidle_driver_lock); } EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); + +struct cpuidle_driver *cpuidle_driver_ref(void) +{ + struct cpuidle_driver *drv; + + spin_lock(&cpuidle_driver_lock); + + drv = cpuidle_curr_driver; + cpuidle_driver_refcount++; + + spin_unlock(&cpuidle_driver_lock); + return drv; +} + +void cpuidle_driver_unref(void) +{ + spin_lock(&cpuidle_driver_lock); + + if (!WARN_ON(cpuidle_driver_refcount <= 0)) + cpuidle_driver_refcount--; + + spin_unlock(&cpuidle_driver_lock); +} diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 8570012a535a..27cfced7b57b 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -136,7 +136,9 @@ struct cpuidle_driver { extern void disable_cpuidle(void); extern int cpuidle_idle_call(void); extern int cpuidle_register_driver(struct cpuidle_driver *drv); -struct cpuidle_driver *cpuidle_get_driver(void); +extern struct cpuidle_driver *cpuidle_get_driver(void); +extern struct cpuidle_driver *cpuidle_driver_ref(void); +extern void cpuidle_driver_unref(void); extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); extern int cpuidle_register_device(struct cpuidle_device *dev); extern void cpuidle_unregister_device(struct cpuidle_device *dev); @@ -157,6 +159,8 @@ static inline int cpuidle_idle_call(void) { return -ENODEV; } static inline int cpuidle_register_driver(struct cpuidle_driver *drv) {return -ENODEV; } static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } +static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } +static inline void cpuidle_driver_unref(void) {} static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } static inline int cpuidle_register_device(struct cpuidle_device *dev) {return -ENODEV; } -- cgit v1.2.3 From 25ac77613aa8fca131599705e3d7da2a0eaa06a0 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Thu, 5 Jul 2012 15:23:25 +0200 Subject: 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: Daniel Lezcano Acked-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_driver.c | 7 ------- drivers/idle/intel_idle.c | 41 +++++++++++++++++++++++++++-------------- include/linux/cpuidle.h | 7 ------- 3 files changed, 27 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 0734086537b8..8648b29f6eec 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 d0f59c3f87ef..fe95d5464a02 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 27cfced7b57b..524bb6f3b6c4 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -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;} -- cgit v1.2.3 From 8651f97bd951d0bb1c10fa24e3fa3455193f3548 Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Mon, 9 Jul 2012 10:12:56 +0200 Subject: PM / cpuidle: System resume hang fix with cpuidle On certain bios, resume hangs if cpus are allowed to enter idle states during suspend [1]. This was fixed in apci idle driver [2].But intel_idle driver does not have this fix. Thus instead of replicating the fix in both the idle drivers, or in more platform specific idle drivers if needed, the more general cpuidle infrastructure could handle this. A suspend callback in cpuidle_driver could handle this fix. But a cpuidle_driver provides only basic functionalities like platform idle state detection capability and mechanisms to support entry and exit into CPU idle states. All other cpuidle functions are found in the cpuidle generic infrastructure for good reason that all cpuidle drivers, irrepective of their platforms will support these functions. One option therefore would be to register a suspend callback in cpuidle which handles this fix. This could be called through a PM_SUSPEND_PREPARE notifier. But this is too generic a notfier for a driver to handle. Also, ideally the job of cpuidle is not to handle side effects of suspend. It should expose the interfaces which "handle cpuidle 'during' suspend" or any other operation, which the subsystems call during that respective operation. The fix demands that during suspend, no cpus should be allowed to enter deep C-states. The interface cpuidle_uninstall_idle_handler() in cpuidle ensures that. Not just that it also kicks all the cpus which are already in idle out of their idle states which was being done during cpu hotplug through a CPU_DYING_FROZEN callbacks. Now the question arises about when during suspend should cpuidle_uninstall_idle_handler() be called. Since we are dealing with drivers it seems best to call this function during dpm_suspend(). Delaying the call till dpm_suspend_noirq() does no harm, as long as it is before cpu_hotplug_begin() to avoid race conditions with cpu hotpulg operations. In dpm_suspend_noirq(), it would be wise to place this call before suspend_device_irqs() to avoid ugly interactions with the same. Ananlogously, during resume. References: [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/674075. [2] http://marc.info/?l=linux-pm&m=133958534231884&w=2 Reported-and-tested-by: Dave Hansen Signed-off-by: Preeti U Murthy Reviewed-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 30 +----------------------------- drivers/base/power/main.c | 4 +++- drivers/cpuidle/cpuidle.c | 16 ++++++++++++++++ include/linux/cpuidle.h | 4 ++++ 4 files changed, 24 insertions(+), 30 deletions(-) (limited to 'include/linux') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 47a8caa89dbe..d8366ee75716 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -221,10 +221,6 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr, #endif -/* - * Suspend / resume control - */ -static int acpi_idle_suspend; static u32 saved_bm_rld; static void acpi_idle_bm_rld_save(void) @@ -243,21 +239,13 @@ static void acpi_idle_bm_rld_restore(void) int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) { - if (acpi_idle_suspend == 1) - return 0; - acpi_idle_bm_rld_save(); - acpi_idle_suspend = 1; return 0; } int acpi_processor_resume(struct acpi_device * device) { - if (acpi_idle_suspend == 0) - return 0; - acpi_idle_bm_rld_restore(); - acpi_idle_suspend = 0; return 0; } @@ -763,11 +751,6 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); @@ -838,11 +821,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; @@ -928,8 +906,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, drv, drv->safe_state_index); } else { local_irq_disable(); - if (!acpi_idle_suspend) - acpi_safe_halt(); + acpi_safe_halt(); local_irq_enable(); return -EBUSY; } @@ -937,11 +914,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, local_irq_disable(); - if (acpi_idle_suspend) { - local_irq_enable(); - cpu_relax(); - return -EBUSY; - } if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 9cb845e49334..63048f79de5f 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -28,7 +28,7 @@ #include #include #include - +#include #include "../base.h" #include "power.h" @@ -467,6 +467,7 @@ static void dpm_resume_noirq(pm_message_t state) mutex_unlock(&dpm_list_mtx); dpm_show_time(starttime, state, "noirq"); resume_device_irqs(); + cpuidle_resume(); } /** @@ -867,6 +868,7 @@ static int dpm_suspend_noirq(pm_message_t state) ktime_t starttime = ktime_get(); int error = 0; + cpuidle_pause(); suspend_device_irqs(); mutex_lock(&dpm_list_mtx); while (!list_empty(&dpm_late_early_list)) { diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 04e4b7674a47..efa9a2ca30e7 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -201,6 +201,22 @@ void cpuidle_resume_and_unlock(void) EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); +/* Currently used in suspend/resume path to suspend cpuidle */ +void cpuidle_pause(void) +{ + mutex_lock(&cpuidle_lock); + cpuidle_uninstall_idle_handler(); + mutex_unlock(&cpuidle_lock); +} + +/* Currently used in suspend/resume path to resume cpuidle */ +void cpuidle_resume(void) +{ + mutex_lock(&cpuidle_lock); + cpuidle_install_idle_handler(); + mutex_unlock(&cpuidle_lock); +} + /** * cpuidle_wrap_enter - performs timekeeping and irqen around enter function * @dev: pointer to a valid cpuidle_device object diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 524bb6f3b6c4..ca6cdf55eb18 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -145,6 +145,8 @@ extern void cpuidle_unregister_device(struct cpuidle_device *dev); extern void cpuidle_pause_and_lock(void); extern void cpuidle_resume_and_unlock(void); +extern void cpuidle_pause(void); +extern void cpuidle_resume(void); extern int cpuidle_enable_device(struct cpuidle_device *dev); extern void cpuidle_disable_device(struct cpuidle_device *dev); extern int cpuidle_wrap_enter(struct cpuidle_device *dev, @@ -168,6 +170,8 @@ static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } static inline void cpuidle_pause_and_lock(void) { } static inline void cpuidle_resume_and_unlock(void) { } +static inline void cpuidle_pause(void) { } +static inline void cpuidle_resume(void) { } static inline int cpuidle_enable_device(struct cpuidle_device *dev) {return -ENODEV; } static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } -- cgit v1.2.3