From 75a80267410e38ab76c4ceb39753f96d72113781 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 13 Dec 2019 09:56:13 +0100 Subject: cpuidle: Allow idle states to be disabled by default In certain situations it may be useful to prevent some idle states from being used by default while allowing user space to enable them later on. For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to mark idle states that should be disabled by default, make the core set CPUIDLE_STATE_DISABLED_BY_USER for those states at the initialization time and add a new state attribute in sysfs, "default_status", to inform user space of the initial status of the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it, "enabled" otherwise). Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/cpuidle.h') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 1dabe36bd011..ebfb52b3ffbf 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -77,6 +77,7 @@ struct cpuidle_state { #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ +#define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ struct cpuidle_device_kobj; struct cpuidle_state_kobj; -- cgit v1.2.3 From 577a2f41f4c7aced4fed41b20ee77cedd8c197cf Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 2 Jan 2020 21:42:16 +0100 Subject: cpuidle: Drop unused cpuidle_driver_ref/unref() functions The cpuidle_driver_ref() and cpuidle_driver_unref() functions are not used and the refcnt field in struct cpuidle_driver operated by them is not updated anywhere else (so it is permanently equal to 0), so drop both of them along with refcnt. Signed-off-by: Rafael J. Wysocki Acked-by: Daniel Lezcano --- drivers/cpuidle/driver.c | 46 ---------------------------------------------- include/linux/cpuidle.h | 5 ----- 2 files changed, 51 deletions(-) (limited to 'include/linux/cpuidle.h') diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index ce6a5f80fb83..4070e573bf43 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -155,8 +155,6 @@ static void __cpuidle_driver_init(struct cpuidle_driver *drv) { int i; - drv->refcnt = 0; - /* * Use all possible CPUs as the default, because if the kernel boots * with some CPUs offline and then we online one of them, the CPU @@ -240,9 +238,6 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv) */ static void __cpuidle_unregister_driver(struct cpuidle_driver *drv) { - if (WARN_ON(drv->refcnt > 0)) - return; - if (drv->bctimer) { drv->bctimer = 0; on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, @@ -349,47 +344,6 @@ struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) } EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver); -/** - * cpuidle_driver_ref - get a reference to the driver. - * - * Increment the reference counter of the cpuidle driver associated with - * the current CPU. - * - * Returns a pointer to the driver, or NULL if the current CPU has no driver. - */ -struct cpuidle_driver *cpuidle_driver_ref(void) -{ - struct cpuidle_driver *drv; - - spin_lock(&cpuidle_driver_lock); - - drv = cpuidle_get_driver(); - if (drv) - drv->refcnt++; - - spin_unlock(&cpuidle_driver_lock); - return drv; -} - -/** - * cpuidle_driver_unref - puts down the refcount for the driver - * - * Decrement the reference counter of the cpuidle driver associated with - * the current CPU. - */ -void cpuidle_driver_unref(void) -{ - struct cpuidle_driver *drv; - - spin_lock(&cpuidle_driver_lock); - - drv = cpuidle_get_driver(); - if (drv && !WARN_ON(drv->refcnt <= 0)) - drv->refcnt--; - - spin_unlock(&cpuidle_driver_lock); -} - /** * cpuidle_driver_state_disabled - Disable or enable an idle state * @drv: cpuidle driver owning the state diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 1dabe36bd011..23744d49bc22 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -115,7 +115,6 @@ DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); struct cpuidle_driver { const char *name; struct module *owner; - int refcnt; /* used by the cpuidle framework to setup the broadcast timer */ unsigned int bctimer:1; @@ -147,8 +146,6 @@ extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, extern int cpuidle_register_driver(struct cpuidle_driver *drv); 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_driver_state_disabled(struct cpuidle_driver *drv, int idx, bool disable); extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); @@ -186,8 +183,6 @@ static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 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_driver_state_disabled(struct cpuidle_driver *drv, int idx, bool disable) { } static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } -- cgit v1.2.3