1 /* 2 * cpuidle.h - a generic framework for CPU idle power management 3 * 4 * (C) 2007 Venkatesh Pallipadi <[email protected]> 5 * Shaohua Li <[email protected]> 6 * Adam Belay <[email protected]> 7 * 8 * This code is licenced under the GPL. 9 */ 10 11 #ifndef _LINUX_CPUIDLE_H 12 #define _LINUX_CPUIDLE_H 13 14 #include <linux/percpu.h> 15 #include <linux/list.h> 16 #include <linux/kobject.h> 17 #include <linux/completion.h> 18 #include <linux/hrtimer.h> 19 20 #define CPUIDLE_STATE_MAX 8 21 #define CPUIDLE_NAME_LEN 16 22 #define CPUIDLE_DESC_LEN 32 23 24 struct module; 25 26 struct cpuidle_device; 27 struct cpuidle_driver; 28 29 30 /**************************** 31 * CPUIDLE DEVICE INTERFACE * 32 ****************************/ 33 34 struct cpuidle_state_usage { 35 unsigned long long disable; 36 unsigned long long usage; 37 unsigned long long time; /* in US */ 38 }; 39 40 struct cpuidle_state { 41 char name[CPUIDLE_NAME_LEN]; 42 char desc[CPUIDLE_DESC_LEN]; 43 44 unsigned int flags; 45 unsigned int exit_latency; /* in US */ 46 int power_usage; /* in mW */ 47 unsigned int target_residency; /* in US */ 48 bool disabled; /* disabled on all CPUs */ 49 50 int (*enter) (struct cpuidle_device *dev, 51 struct cpuidle_driver *drv, 52 int index); 53 54 int (*enter_dead) (struct cpuidle_device *dev, int index); 55 }; 56 57 /* Idle State Flags */ 58 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 59 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 60 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 61 62 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 63 64 struct cpuidle_device { 65 unsigned int registered:1; 66 unsigned int enabled:1; 67 unsigned int cpu; 68 69 int last_residency; 70 int state_count; 71 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 72 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 73 struct cpuidle_driver_kobj *kobj_driver; 74 struct list_head device_list; 75 struct kobject kobj; 76 struct completion kobj_unregister; 77 78 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 79 int safe_state_index; 80 cpumask_t coupled_cpus; 81 struct cpuidle_coupled *coupled; 82 #endif 83 }; 84 85 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 86 87 /** 88 * cpuidle_get_last_residency - retrieves the last state's residency time 89 * @dev: the target CPU 90 * 91 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 92 */ 93 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 94 { 95 return dev->last_residency; 96 } 97 98 99 /**************************** 100 * CPUIDLE DRIVER INTERFACE * 101 ****************************/ 102 103 struct cpuidle_driver { 104 const char *name; 105 struct module *owner; 106 int refcnt; 107 108 /* used by the cpuidle framework to setup the broadcast timer */ 109 unsigned int bctimer:1; 110 /* states array must be ordered in decreasing power consumption */ 111 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 112 int state_count; 113 int safe_state_index; 114 }; 115 116 #ifdef CONFIG_CPU_IDLE 117 extern void disable_cpuidle(void); 118 extern int cpuidle_idle_call(void); 119 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 120 extern struct cpuidle_driver *cpuidle_get_driver(void); 121 extern struct cpuidle_driver *cpuidle_driver_ref(void); 122 extern void cpuidle_driver_unref(void); 123 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 124 extern int cpuidle_register_device(struct cpuidle_device *dev); 125 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 126 127 extern void cpuidle_pause_and_lock(void); 128 extern void cpuidle_resume_and_unlock(void); 129 extern void cpuidle_pause(void); 130 extern void cpuidle_resume(void); 131 extern int cpuidle_enable_device(struct cpuidle_device *dev); 132 extern void cpuidle_disable_device(struct cpuidle_device *dev); 133 extern int cpuidle_play_dead(void); 134 135 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 136 extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu); 137 extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu); 138 139 #else 140 static inline void disable_cpuidle(void) { } 141 static inline int cpuidle_idle_call(void) { return -ENODEV; } 142 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 143 {return -ENODEV; } 144 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 145 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 146 static inline void cpuidle_driver_unref(void) {} 147 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 148 static inline int cpuidle_register_device(struct cpuidle_device *dev) 149 {return -ENODEV; } 150 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 151 152 static inline void cpuidle_pause_and_lock(void) { } 153 static inline void cpuidle_resume_and_unlock(void) { } 154 static inline void cpuidle_pause(void) { } 155 static inline void cpuidle_resume(void) { } 156 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 157 {return -ENODEV; } 158 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 159 static inline int cpuidle_play_dead(void) {return -ENODEV; } 160 #endif 161 162 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 163 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 164 #else 165 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 166 { 167 } 168 #endif 169 170 /****************************** 171 * CPUIDLE GOVERNOR INTERFACE * 172 ******************************/ 173 174 struct cpuidle_governor { 175 char name[CPUIDLE_NAME_LEN]; 176 struct list_head governor_list; 177 unsigned int rating; 178 179 int (*enable) (struct cpuidle_driver *drv, 180 struct cpuidle_device *dev); 181 void (*disable) (struct cpuidle_driver *drv, 182 struct cpuidle_device *dev); 183 184 int (*select) (struct cpuidle_driver *drv, 185 struct cpuidle_device *dev); 186 void (*reflect) (struct cpuidle_device *dev, int index); 187 188 struct module *owner; 189 }; 190 191 #ifdef CONFIG_CPU_IDLE 192 193 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 194 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 195 196 #else 197 198 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 199 {return 0;} 200 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 201 202 #endif 203 204 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 205 #define CPUIDLE_DRIVER_STATE_START 1 206 #else 207 #define CPUIDLE_DRIVER_STATE_START 0 208 #endif 209 210 #endif /* _LINUX_CPUIDLE_H */ 211