diff options
Diffstat (limited to 'drivers/cpuidle/driver.c')
| -rw-r--r-- | drivers/cpuidle/driver.c | 222 |
1 files changed, 171 insertions, 51 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 87db3877fea..422c7b69ba7 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -14,37 +14,17 @@ #include "cpuidle.h" -static struct cpuidle_driver *cpuidle_curr_driver; DEFINE_SPINLOCK(cpuidle_driver_lock); -int cpuidle_driver_refcount; - -static void set_power_states(struct cpuidle_driver *drv) -{ - int i; - - /* - * cpuidle driver should set the drv->power_specified bit - * before registering if the driver provides - * power_usage numbers. - * - * If power_specified is not set, - * we fill in power_usage with decreasing values as the - * cpuidle code has an implicit assumption that state Cn - * uses less power than C(n-1). - * - * With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned - * an power value of -1. So we use -2, -3, etc, for other - * c-states. - */ - for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) - drv->states[i].power_usage = -1 - i; + +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_driver_init(struct cpuidle_driver *drv) +{ + drv->refcnt = 0; } -/** - * cpuidle_register_driver - registers a driver - * @drv: the driver - */ -int cpuidle_register_driver(struct cpuidle_driver *drv) +static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu) { if (!drv || !drv->state_count) return -EINVAL; @@ -52,31 +32,101 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) if (cpuidle_disabled()) return -ENODEV; - spin_lock(&cpuidle_driver_lock); - if (cpuidle_curr_driver) { - spin_unlock(&cpuidle_driver_lock); + if (__cpuidle_get_cpu_driver(cpu)) return -EBUSY; + + __cpuidle_driver_init(drv); + + __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); +} + +#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 (!drv->power_specified) - set_power_states(drv); + if (ret) + for_each_present_cpu(i) { + if (i == cpu) + break; + __cpuidle_unregister_driver(drv, i); + } - cpuidle_curr_driver = drv; + 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 0; + 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); } -EXPORT_SYMBOL_GPL(cpuidle_register_driver); /** - * cpuidle_get_driver - return the current driver + * cpuidle_register_driver - registers a driver + * @drv: the driver */ -struct cpuidle_driver *cpuidle_get_driver(void) +int cpuidle_register_driver(struct cpuidle_driver *drv) { - return cpuidle_curr_driver; + 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_get_driver); +EXPORT_SYMBOL_GPL(cpuidle_register_driver); /** * cpuidle_unregister_driver - unregisters a driver @@ -84,20 +134,88 @@ EXPORT_SYMBOL_GPL(cpuidle_get_driver); */ void cpuidle_unregister_driver(struct cpuidle_driver *drv) { - if (drv != cpuidle_curr_driver) { - WARN(1, "invalid cpuidle_unregister_driver(%s)\n", - drv->name); - return; - } + 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); - if (!WARN_ON(cpuidle_driver_refcount > 0)) - cpuidle_curr_driver = NULL; +/** + * 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) { @@ -105,8 +223,8 @@ struct cpuidle_driver *cpuidle_driver_ref(void) spin_lock(&cpuidle_driver_lock); - drv = cpuidle_curr_driver; - cpuidle_driver_refcount++; + drv = cpuidle_get_driver(); + drv->refcnt++; spin_unlock(&cpuidle_driver_lock); return drv; @@ -114,10 +232,12 @@ struct cpuidle_driver *cpuidle_driver_ref(void) void cpuidle_driver_unref(void) { + struct cpuidle_driver *drv = cpuidle_get_driver(); + spin_lock(&cpuidle_driver_lock); - if (!WARN_ON(cpuidle_driver_refcount <= 0)) - cpuidle_driver_refcount--; + if (drv && !WARN_ON(drv->refcnt <= 0)) + drv->refcnt--; spin_unlock(&cpuidle_driver_lock); } |