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 24struct cpuidle_device; 25 26 27/**************************** 28 * CPUIDLE DEVICE INTERFACE * 29 ****************************/ 30 31struct 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 */ 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 */ 72static inline void 73cpuidle_set_statedata(struct cpuidle_state *state, void *data) 74{ 75 state->driver_data = data; 76} 77 78struct cpuidle_state_kobj { 79 struct cpuidle_state *state; 80 struct completion kobj_unregister; 81 struct kobject kobj; 82}; 83 84struct 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 102DECLARE_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 */ 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 120struct cpuidle_driver { 121 char name[CPUIDLE_NAME_LEN]; 122 struct module *owner; 123}; 124 125#ifdef CONFIG_CPU_IDLE 126 127extern int cpuidle_register_driver(struct cpuidle_driver *drv); 128extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 129extern int cpuidle_register_device(struct cpuidle_device *dev); 130extern void cpuidle_unregister_device(struct cpuidle_device *dev); 131 132extern void cpuidle_pause_and_lock(void); 133extern void cpuidle_resume_and_unlock(void); 134extern int cpuidle_enable_device(struct cpuidle_device *dev); 135extern void cpuidle_disable_device(struct cpuidle_device *dev); 136 137#else 138 139static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 140{return 0;} 141static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 142static inline int cpuidle_register_device(struct cpuidle_device *dev) 143{return 0;} 144static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 145 146static inline void cpuidle_pause_and_lock(void) { } 147static inline void cpuidle_resume_and_unlock(void) { } 148static inline int cpuidle_enable_device(struct cpuidle_device *dev) 149{return 0;} 150static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 151 152#endif 153 154/****************************** 155 * CPUIDLE GOVERNOR INTERFACE * 156 ******************************/ 157 158struct 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 174extern int cpuidle_register_governor(struct cpuidle_governor *gov); 175extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 176 177#else 178 179static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 180{return 0;} 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