From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/cpuidle/driver.c | 391 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 391 insertions(+) create mode 100644 drivers/cpuidle/driver.c (limited to 'drivers/cpuidle/driver.c') diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c new file mode 100644 index 000000000..d9cda7f6c --- /dev/null +++ b/drivers/cpuidle/driver.c @@ -0,0 +1,391 @@ +/* + * driver.c - driver support + * + * (C) 2006-2007 Venkatesh Pallipadi + * Shaohua Li + * Adam Belay + * + * This code is licenced under the GPL. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "cpuidle.h" + +DEFINE_SPINLOCK(cpuidle_driver_lock); + +#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS + +static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers); + +/** + * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU. + * @cpu: the CPU handled by the driver + * + * Returns a pointer to struct cpuidle_driver or NULL if no driver has been + * registered for @cpu. + */ +static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) +{ + return per_cpu(cpuidle_drivers, cpu); +} + +/** + * __cpuidle_unset_driver - unset per CPU driver variables. + * @drv: a valid pointer to a struct cpuidle_driver + * + * For each CPU in the driver's CPU mask, unset the registered driver per CPU + * variable. If @drv is different from the registered driver, the corresponding + * variable is not cleared. + */ +static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv) +{ + int cpu; + + for_each_cpu(cpu, drv->cpumask) { + + if (drv != __cpuidle_get_cpu_driver(cpu)) + continue; + + per_cpu(cpuidle_drivers, cpu) = NULL; + } +} + +/** + * __cpuidle_set_driver - set per CPU driver variables for the given driver. + * @drv: a valid pointer to a struct cpuidle_driver + * + * Returns 0 on success, -EBUSY if any CPU in the cpumask have a driver + * different from drv already. + */ +static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) +{ + int cpu; + + for_each_cpu(cpu, drv->cpumask) { + struct cpuidle_driver *old_drv; + + old_drv = __cpuidle_get_cpu_driver(cpu); + if (old_drv && old_drv != drv) + return -EBUSY; + } + + for_each_cpu(cpu, drv->cpumask) + per_cpu(cpuidle_drivers, cpu) = drv; + + return 0; +} + +#else + +static struct cpuidle_driver *cpuidle_curr_driver; + +/** + * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer. + * @cpu: ignored without the multiple driver support + * + * Return a pointer to a struct cpuidle_driver object or NULL if no driver was + * previously registered. + */ +static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) +{ + return cpuidle_curr_driver; +} + +/** + * __cpuidle_set_driver - assign the global cpuidle driver variable. + * @drv: pointer to a struct cpuidle_driver object + * + * Returns 0 on success, -EBUSY if the driver is already registered. + */ +static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) +{ + if (cpuidle_curr_driver) + return -EBUSY; + + cpuidle_curr_driver = drv; + + return 0; +} + +/** + * __cpuidle_unset_driver - unset the global cpuidle driver variable. + * @drv: a pointer to a struct cpuidle_driver + * + * Reset the global cpuidle variable to NULL. If @drv does not match the + * registered driver, do nothing. + */ +static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv) +{ + if (drv == cpuidle_curr_driver) + cpuidle_curr_driver = NULL; +} + +#endif + +/** + * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer on a cpu + * @arg: a void pointer used to match the SMP cross call API + * + * If @arg is NULL broadcast is disabled otherwise enabled + * + * This function is executed per CPU by an SMP cross call. It's not + * supposed to be called directly. + */ +static void cpuidle_setup_broadcast_timer(void *arg) +{ + if (arg) + tick_broadcast_enable(); + else + tick_broadcast_disable(); +} + +/** + * __cpuidle_driver_init - initialize the driver's internal data + * @drv: a valid pointer to a struct cpuidle_driver + */ +static void __cpuidle_driver_init(struct cpuidle_driver *drv) +{ + int i; + + /* + * 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 + * notifier has to know which driver to assign. + */ + if (!drv->cpumask) + drv->cpumask = (struct cpumask *)cpu_possible_mask; + + for (i = 0; i < drv->state_count; i++) { + struct cpuidle_state *s = &drv->states[i]; + + /* + * Look for the timer stop flag in the different states and if + * it is found, indicate that the broadcast timer has to be set + * up. + */ + if (s->flags & CPUIDLE_FLAG_TIMER_STOP) + drv->bctimer = 1; + + /* + * The core will use the target residency and exit latency + * values in nanoseconds, but allow drivers to provide them in + * microseconds too. + */ + if (s->target_residency > 0) + s->target_residency_ns = s->target_residency * NSEC_PER_USEC; + else if (s->target_residency_ns < 0) + s->target_residency_ns = 0; + else + s->target_residency = div_u64(s->target_residency_ns, NSEC_PER_USEC); + + if (s->exit_latency > 0) + s->exit_latency_ns = s->exit_latency * NSEC_PER_USEC; + else if (s->exit_latency_ns < 0) + s->exit_latency_ns = 0; + else + s->exit_latency = div_u64(s->exit_latency_ns, NSEC_PER_USEC); + } +} + +/** + * __cpuidle_register_driver: register the driver + * @drv: a valid pointer to a struct cpuidle_driver + * + * Do some sanity checks, initialize the driver, assign the driver to the + * global cpuidle driver variable(s) and set up the broadcast timer if the + * cpuidle driver has some states that shut down the local timer. + * + * Returns 0 on success, a negative error code otherwise: + * * -EINVAL if the driver pointer is NULL or no idle states are available + * * -ENODEV if the cpuidle framework is disabled + * * -EBUSY if the driver is already assigned to the global variable(s) + */ +static int __cpuidle_register_driver(struct cpuidle_driver *drv) +{ + int ret; + + if (!drv || !drv->state_count) + return -EINVAL; + + ret = cpuidle_coupled_state_verify(drv); + if (ret) + return ret; + + if (cpuidle_disabled()) + return -ENODEV; + + __cpuidle_driver_init(drv); + + ret = __cpuidle_set_driver(drv); + if (ret) + return ret; + + if (drv->bctimer) + on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, + (void *)1, 1); + + return 0; +} + +/** + * __cpuidle_unregister_driver - unregister the driver + * @drv: a valid pointer to a struct cpuidle_driver + * + * Check if the driver is no longer in use, reset the global cpuidle driver + * variable(s) and disable the timer broadcast notification mechanism if it was + * in use. + * + */ +static void __cpuidle_unregister_driver(struct cpuidle_driver *drv) +{ + if (drv->bctimer) { + drv->bctimer = 0; + on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, + NULL, 1); + } + + __cpuidle_unset_driver(drv); +} + +/** + * cpuidle_register_driver - registers a driver + * @drv: a pointer to a valid struct cpuidle_driver + * + * Register the driver under a lock to prevent concurrent attempts to + * [un]register the driver from occuring at the same time. + * + * Returns 0 on success, a negative error code (returned by + * __cpuidle_register_driver()) otherwise. + */ +int cpuidle_register_driver(struct cpuidle_driver *drv) +{ + struct cpuidle_governor *gov; + int ret; + + spin_lock(&cpuidle_driver_lock); + ret = __cpuidle_register_driver(drv); + spin_unlock(&cpuidle_driver_lock); + + if (!ret && !strlen(param_governor) && drv->governor && + (cpuidle_get_driver() == drv)) { + mutex_lock(&cpuidle_lock); + gov = cpuidle_find_governor(drv->governor); + if (gov) { + cpuidle_prev_governor = cpuidle_curr_governor; + if (cpuidle_switch_governor(gov) < 0) + cpuidle_prev_governor = NULL; + } + mutex_unlock(&cpuidle_lock); + } + + return ret; +} +EXPORT_SYMBOL_GPL(cpuidle_register_driver); + +/** + * cpuidle_unregister_driver - unregisters a driver + * @drv: a pointer to a valid struct cpuidle_driver + * + * Unregisters the cpuidle driver under a lock to prevent concurrent attempts + * to [un]register the driver from occuring at the same time. @drv has to + * match the currently registered driver. + */ +void cpuidle_unregister_driver(struct cpuidle_driver *drv) +{ + bool enabled = (cpuidle_get_driver() == drv); + + spin_lock(&cpuidle_driver_lock); + __cpuidle_unregister_driver(drv); + spin_unlock(&cpuidle_driver_lock); + + if (!enabled) + return; + + mutex_lock(&cpuidle_lock); + if (cpuidle_prev_governor) { + if (!cpuidle_switch_governor(cpuidle_prev_governor)) + cpuidle_prev_governor = NULL; + } + mutex_unlock(&cpuidle_lock); +} +EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); + +/** + * cpuidle_get_driver - return the driver tied to the current CPU. + * + * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered. + */ +struct cpuidle_driver *cpuidle_get_driver(void) +{ + struct cpuidle_driver *drv; + int cpu; + + cpu = get_cpu(); + drv = __cpuidle_get_cpu_driver(cpu); + put_cpu(); + + return drv; +} +EXPORT_SYMBOL_GPL(cpuidle_get_driver); + +/** + * cpuidle_get_cpu_driver - return the driver registered for a CPU. + * @dev: a valid pointer to a struct cpuidle_device + * + * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered + * for the CPU associated with @dev. + */ +struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) +{ + if (!dev) + return NULL; + + return __cpuidle_get_cpu_driver(dev->cpu); +} +EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver); + +/** + * cpuidle_driver_state_disabled - Disable or enable an idle state + * @drv: cpuidle driver owning the state + * @idx: State index + * @disable: Whether or not to disable the state + */ +void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, + bool disable) +{ + unsigned int cpu; + + mutex_lock(&cpuidle_lock); + + spin_lock(&cpuidle_driver_lock); + + if (!drv->cpumask) { + drv->states[idx].flags |= CPUIDLE_FLAG_UNUSABLE; + goto unlock; + } + + for_each_cpu(cpu, drv->cpumask) { + struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); + + if (!dev) + continue; + + if (disable) + dev->states_usage[idx].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; + else + dev->states_usage[idx].disable &= ~CPUIDLE_STATE_DISABLED_BY_DRIVER; + } + +unlock: + spin_unlock(&cpuidle_driver_lock); + + mutex_unlock(&cpuidle_lock); +} -- cgit v1.2.3