| /* |
| * 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); |
| } |