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_IGNORE (0x100) /* ignore during this idle period */ 51 52#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 53 54/** 55 * cpuidle_get_statedata - retrieves private driver state data 56 * @state: the state 57 */ 58static inline void * cpuidle_get_statedata(struct cpuidle_state *state) 59{ 60 return state->driver_data; 61} 62 63/** 64 * cpuidle_set_statedata - stores private driver state data 65 * @state: the state 66 * @data: the private data 67 */ 68static inline void 69cpuidle_set_statedata(struct cpuidle_state *state, void *data) 70{ 71 state->driver_data = data; 72} 73 74struct cpuidle_state_kobj { 75 struct cpuidle_state *state; 76 struct completion kobj_unregister; 77 struct kobject kobj; 78}; 79 80struct cpuidle_device { 81 unsigned int registered:1; 82 unsigned int enabled:1; 83 unsigned int power_specified:1; 84 unsigned int cpu; 85 86 int last_residency; 87 int state_count; 88 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 90 struct cpuidle_state *last_state; 91 92 struct list_head device_list; 93 struct kobject kobj; 94 struct completion kobj_unregister; 95 void *governor_data; 96 struct cpuidle_state *safe_state; 97 98 int (*prepare) (struct cpuidle_device *dev); 99}; 100 101DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 102 103/** 104 * cpuidle_get_last_residency - retrieves the last state's residency time 105 * @dev: the target CPU 106 * 107 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 108 */ 109static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 110{ 111 return dev->last_residency; 112} 113 114 115/**************************** 116 * CPUIDLE DRIVER INTERFACE * 117 ****************************/ 118 119struct cpuidle_driver { 120 char name[CPUIDLE_NAME_LEN]; 121 struct module *owner; 122}; 123 124#ifdef CONFIG_CPU_IDLE 125extern void disable_cpuidle(void); 126extern int cpuidle_idle_call(void); 127 128extern int cpuidle_register_driver(struct cpuidle_driver *drv); 129struct cpuidle_driver *cpuidle_get_driver(void); 130extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 131extern int cpuidle_register_device(struct cpuidle_device *dev); 132extern void cpuidle_unregister_device(struct cpuidle_device *dev); 133 134extern void cpuidle_pause_and_lock(void); 135extern void cpuidle_resume_and_unlock(void); 136extern int cpuidle_enable_device(struct cpuidle_device *dev); 137extern void cpuidle_disable_device(struct cpuidle_device *dev); 138 139#else 140static inline void disable_cpuidle(void) { } 141static inline int cpuidle_idle_call(void) { return -ENODEV; } 142 143static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 144{return -ENODEV; } 145static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 146static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 147static inline int cpuidle_register_device(struct cpuidle_device *dev) 148{return -ENODEV; } 149static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 150 151static inline void cpuidle_pause_and_lock(void) { } 152static inline void cpuidle_resume_and_unlock(void) { } 153static inline int cpuidle_enable_device(struct cpuidle_device *dev) 154{return -ENODEV; } 155static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 156 157#endif 158 159/****************************** 160 * CPUIDLE GOVERNOR INTERFACE * 161 ******************************/ 162 163struct cpuidle_governor { 164 char name[CPUIDLE_NAME_LEN]; 165 struct list_head governor_list; 166 unsigned int rating; 167 168 int (*enable) (struct cpuidle_device *dev); 169 void (*disable) (struct cpuidle_device *dev); 170 171 int (*select) (struct cpuidle_device *dev); 172 void (*reflect) (struct cpuidle_device *dev); 173 174 struct module *owner; 175}; 176 177#ifdef CONFIG_CPU_IDLE 178 179extern int cpuidle_register_governor(struct cpuidle_governor *gov); 180extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 181 182#else 183 184static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 185{return 0;} 186static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 187 188#endif 189 190#ifdef CONFIG_ARCH_HAS_CPU_RELAX 191#define CPUIDLE_DRIVER_STATE_START 1 192#else 193#define CPUIDLE_DRIVER_STATE_START 0 194#endif 195 196#endif /* _LINUX_CPUIDLE_H */ 197