1 /* 2 * cpuidle.h - a generic framework for CPU idle power management 3 * 4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 5 * Shaohua Li <shaohua.li@intel.com> 6 * Adam Belay <abelay@novell.com> 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/module.h> 17 #include <linux/kobject.h> 18 #include <linux/completion.h> 19 20 #define CPUIDLE_STATE_MAX 8 21 #define CPUIDLE_NAME_LEN 16 22 #define CPUIDLE_DESC_LEN 32 23 24 struct cpuidle_device; 25 26 27 /**************************** 28 * CPUIDLE DEVICE INTERFACE * 29 ****************************/ 30 31 struct cpuidle_state { 32 char name[CPUIDLE_NAME_LEN]; 33 char desc[CPUIDLE_DESC_LEN]; 34 void *driver_data; 35 36 unsigned int flags; 37 unsigned int exit_latency; /* in US */ 38 unsigned int power_usage; /* in mW */ 39 unsigned int target_residency; /* in US */ 40 41 unsigned long long usage; 42 unsigned long long time; /* in US */ 43 44 int (*enter) (struct cpuidle_device *dev, 45 struct cpuidle_state *state); 46 }; 47 48 /* Idle State Flags */ 49 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 50 #define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */ 51 #define CPUIDLE_FLAG_POLL (0x10) /* no latency, no savings */ 52 #define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */ 53 #define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */ 54 #define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */ 55 56 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 57 58 /** 59 * cpuidle_get_statedata - retrieves private driver state data 60 * @state: the state 61 */ cpuidle_get_statedata(struct cpuidle_state * state)62static inline void * cpuidle_get_statedata(struct cpuidle_state *state) 63 { 64 return state->driver_data; 65 } 66 67 /** 68 * cpuidle_set_statedata - stores private driver state data 69 * @state: the state 70 * @data: the private data 71 */ 72 static inline void cpuidle_set_statedata(struct cpuidle_state * state,void * data)73cpuidle_set_statedata(struct cpuidle_state *state, void *data) 74 { 75 state->driver_data = data; 76 } 77 78 struct cpuidle_state_kobj { 79 struct cpuidle_state *state; 80 struct completion kobj_unregister; 81 struct kobject kobj; 82 }; 83 84 struct cpuidle_device { 85 unsigned int registered:1; 86 unsigned int enabled:1; 87 unsigned int cpu; 88 89 int last_residency; 90 int state_count; 91 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 92 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 93 struct cpuidle_state *last_state; 94 95 struct list_head device_list; 96 struct kobject kobj; 97 struct completion kobj_unregister; 98 void *governor_data; 99 struct cpuidle_state *safe_state; 100 }; 101 102 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 103 104 /** 105 * cpuidle_get_last_residency - retrieves the last state's residency time 106 * @dev: the target CPU 107 * 108 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 109 */ cpuidle_get_last_residency(struct cpuidle_device * dev)110static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 111 { 112 return dev->last_residency; 113 } 114 115 116 /**************************** 117 * CPUIDLE DRIVER INTERFACE * 118 ****************************/ 119 120 struct cpuidle_driver { 121 char name[CPUIDLE_NAME_LEN]; 122 struct module *owner; 123 }; 124 125 #ifdef CONFIG_CPU_IDLE 126 127 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 128 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 129 extern int cpuidle_register_device(struct cpuidle_device *dev); 130 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 131 132 extern void cpuidle_pause_and_lock(void); 133 extern void cpuidle_resume_and_unlock(void); 134 extern int cpuidle_enable_device(struct cpuidle_device *dev); 135 extern void cpuidle_disable_device(struct cpuidle_device *dev); 136 137 #else 138 cpuidle_register_driver(struct cpuidle_driver * drv)139static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 140 {return 0;} cpuidle_unregister_driver(struct cpuidle_driver * drv)141static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } cpuidle_register_device(struct cpuidle_device * dev)142static inline int cpuidle_register_device(struct cpuidle_device *dev) 143 {return 0;} cpuidle_unregister_device(struct cpuidle_device * dev)144static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 145 cpuidle_pause_and_lock(void)146static inline void cpuidle_pause_and_lock(void) { } cpuidle_resume_and_unlock(void)147static inline void cpuidle_resume_and_unlock(void) { } cpuidle_enable_device(struct cpuidle_device * dev)148static inline int cpuidle_enable_device(struct cpuidle_device *dev) 149 {return 0;} cpuidle_disable_device(struct cpuidle_device * dev)150static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 151 152 #endif 153 154 /****************************** 155 * CPUIDLE GOVERNOR INTERFACE * 156 ******************************/ 157 158 struct cpuidle_governor { 159 char name[CPUIDLE_NAME_LEN]; 160 struct list_head governor_list; 161 unsigned int rating; 162 163 int (*enable) (struct cpuidle_device *dev); 164 void (*disable) (struct cpuidle_device *dev); 165 166 int (*select) (struct cpuidle_device *dev); 167 void (*reflect) (struct cpuidle_device *dev); 168 169 struct module *owner; 170 }; 171 172 #ifdef CONFIG_CPU_IDLE 173 174 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 175 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 176 177 #else 178 cpuidle_register_governor(struct cpuidle_governor * gov)179static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 180 {return 0;} cpuidle_unregister_governor(struct cpuidle_governor * gov)181static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 182 183 #endif 184 185 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 186 #define CPUIDLE_DRIVER_STATE_START 1 187 #else 188 #define CPUIDLE_DRIVER_STATE_START 0 189 #endif 190 191 #endif /* _LINUX_CPUIDLE_H */ 192