diff options
Diffstat (limited to 'drivers/cpuidle/driver.c')
| -rw-r--r-- | drivers/cpuidle/driver.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c new file mode 100644 index 00000000..2253271b --- /dev/null +++ b/drivers/cpuidle/driver.c @@ -0,0 +1,271 @@ +/* + * driver.c - driver support + * + * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> + * Shaohua Li <shaohua.li@intel.com> + * Adam Belay <abelay@novell.com> + * + * This code is licenced under the GPL. + */ + +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/cpuidle.h> +#include <linux/cpumask.h> +#include <linux/clockchips.h> + +#include "cpuidle.h" + +DEFINE_SPINLOCK(cpuidle_driver_lock); + +static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu); +static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu); + +static void cpuidle_setup_broadcast_timer(void *arg) +{ + int cpu = smp_processor_id(); + clockevents_notify((long)(arg), &cpu); +} + +static void __cpuidle_driver_init(struct cpuidle_driver *drv, int cpu) +{ + int i; + + drv->refcnt = 0; + + for (i = drv->state_count - 1; i >= 0 ; i--) { + + if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP)) + continue; + + drv->bctimer = 1; + on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer, + (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1); + break; + } +} + +static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu) +{ + if (!drv || !drv->state_count) + return -EINVAL; + + if (cpuidle_disabled()) + return -ENODEV; + + if (__cpuidle_get_cpu_driver(cpu)) + return -EBUSY; + + __cpuidle_driver_init(drv, cpu); + + __cpuidle_set_cpu_driver(drv, cpu); + + return 0; +} + +static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu) +{ + if (drv != __cpuidle_get_cpu_driver(cpu)) + return; + + if (!WARN_ON(drv->refcnt > 0)) + __cpuidle_set_cpu_driver(NULL, cpu); + + if (drv->bctimer) { + drv->bctimer = 0; + on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer, + (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1); + } +} + +#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS + +static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers); + +static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu) +{ + per_cpu(cpuidle_drivers, cpu) = drv; +} + +static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) +{ + return per_cpu(cpuidle_drivers, cpu); +} + +static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv) +{ + int cpu; + for_each_present_cpu(cpu) + __cpuidle_unregister_driver(drv, cpu); +} + +static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv) +{ + int ret = 0; + int i, cpu; + + for_each_present_cpu(cpu) { + ret = __cpuidle_register_driver(drv, cpu); + if (ret) + break; + } + + if (ret) + for_each_present_cpu(i) { + if (i == cpu) + break; + __cpuidle_unregister_driver(drv, i); + } + + + return ret; +} + +int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu) +{ + int ret; + + spin_lock(&cpuidle_driver_lock); + ret = __cpuidle_register_driver(drv, cpu); + spin_unlock(&cpuidle_driver_lock); + + return ret; +} + +void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu) +{ + spin_lock(&cpuidle_driver_lock); + __cpuidle_unregister_driver(drv, cpu); + spin_unlock(&cpuidle_driver_lock); +} + +/** + * cpuidle_register_driver - registers a driver + * @drv: the driver + */ +int cpuidle_register_driver(struct cpuidle_driver *drv) +{ + int ret; + + spin_lock(&cpuidle_driver_lock); + ret = __cpuidle_register_all_cpu_driver(drv); + spin_unlock(&cpuidle_driver_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(cpuidle_register_driver); + +/** + * cpuidle_unregister_driver - unregisters a driver + * @drv: the driver + */ +void cpuidle_unregister_driver(struct cpuidle_driver *drv) +{ + spin_lock(&cpuidle_driver_lock); + __cpuidle_unregister_all_cpu_driver(drv); + spin_unlock(&cpuidle_driver_lock); +} +EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); + +#else + +static struct cpuidle_driver *cpuidle_curr_driver; + +static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu) +{ + cpuidle_curr_driver = drv; +} + +static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) +{ + return cpuidle_curr_driver; +} + +/** + * cpuidle_register_driver - registers a driver + * @drv: the driver + */ +int cpuidle_register_driver(struct cpuidle_driver *drv) +{ + int ret, cpu; + + cpu = get_cpu(); + spin_lock(&cpuidle_driver_lock); + ret = __cpuidle_register_driver(drv, cpu); + spin_unlock(&cpuidle_driver_lock); + put_cpu(); + + return ret; +} +EXPORT_SYMBOL_GPL(cpuidle_register_driver); + +/** + * cpuidle_unregister_driver - unregisters a driver + * @drv: the driver + */ +void cpuidle_unregister_driver(struct cpuidle_driver *drv) +{ + int cpu; + + cpu = get_cpu(); + spin_lock(&cpuidle_driver_lock); + __cpuidle_unregister_driver(drv, cpu); + spin_unlock(&cpuidle_driver_lock); + put_cpu(); +} +EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); +#endif + +/** + * cpuidle_get_driver - return the current driver + */ +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 tied with a cpu + */ +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); + +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; +} + +void cpuidle_driver_unref(void) +{ + struct cpuidle_driver *drv = cpuidle_get_driver(); + + spin_lock(&cpuidle_driver_lock); + + if (drv && !WARN_ON(drv->refcnt <= 0)) + drv->refcnt--; + + spin_unlock(&cpuidle_driver_lock); +} |