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/kobject.h> 17#include <linux/completion.h> 18 19#define CPUIDLE_STATE_MAX 8 20#define CPUIDLE_NAME_LEN 16 21#define CPUIDLE_DESC_LEN 32 22 23struct module; 24 25struct cpuidle_device; 26struct cpuidle_driver; 27 28 29/**************************** 30 * CPUIDLE DEVICE INTERFACE * 31 ****************************/ 32 33struct cpuidle_state_usage { 34 void *driver_data; 35 36 unsigned long long usage; 37 unsigned long long time; /* in US */ 38}; 39 40struct 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 unsigned int power_usage; /* in mW */ 47 unsigned int target_residency; /* in US */ 48 49 int (*enter) (struct cpuidle_device *dev, 50 struct cpuidle_driver *drv, 51 int index); 52}; 53 54/* Idle State Flags */ 55#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 56 57#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 58 59/** 60 * cpuidle_get_statedata - retrieves private driver state data 61 * @st_usage: the state usage statistics 62 */ 63static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage) 64{ 65 return st_usage->driver_data; 66} 67 68/** 69 * cpuidle_set_statedata - stores private driver state data 70 * @st_usage: the state usage statistics 71 * @data: the private data 72 */ 73static inline void 74cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data) 75{ 76 st_usage->driver_data = data; 77} 78 79struct cpuidle_state_kobj { 80 struct cpuidle_state *state; 81 struct cpuidle_state_usage *state_usage; 82 struct completion kobj_unregister; 83 struct kobject kobj; 84}; 85 86struct cpuidle_device { 87 unsigned int registered:1; 88 unsigned int enabled:1; 89 unsigned int cpu; 90 91 int last_residency; 92 int state_count; 93 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 94 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 95 96 struct list_head device_list; 97 struct kobject kobj; 98 struct completion kobj_unregister; 99 void *governor_data; 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 unsigned int power_specified:1; 125 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 126 int state_count; 127 int safe_state_index; 128}; 129 130#ifdef CONFIG_CPU_IDLE 131extern void disable_cpuidle(void); 132extern int cpuidle_idle_call(void); 133extern int cpuidle_register_driver(struct cpuidle_driver *drv); 134struct cpuidle_driver *cpuidle_get_driver(void); 135extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 136extern int cpuidle_register_device(struct cpuidle_device *dev); 137extern void cpuidle_unregister_device(struct cpuidle_device *dev); 138 139extern void cpuidle_pause_and_lock(void); 140extern void cpuidle_resume_and_unlock(void); 141extern int cpuidle_enable_device(struct cpuidle_device *dev); 142extern void cpuidle_disable_device(struct cpuidle_device *dev); 143 144#else 145static inline void disable_cpuidle(void) { } 146static inline int cpuidle_idle_call(void) { return -ENODEV; } 147static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 148{return -ENODEV; } 149static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 150static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 151static inline int cpuidle_register_device(struct cpuidle_device *dev) 152{return -ENODEV; } 153static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 154 155static inline void cpuidle_pause_and_lock(void) { } 156static inline void cpuidle_resume_and_unlock(void) { } 157static inline int cpuidle_enable_device(struct cpuidle_device *dev) 158{return -ENODEV; } 159static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 160 161#endif 162 163/****************************** 164 * CPUIDLE GOVERNOR INTERFACE * 165 ******************************/ 166 167struct cpuidle_governor { 168 char name[CPUIDLE_NAME_LEN]; 169 struct list_head governor_list; 170 unsigned int rating; 171 172 int (*enable) (struct cpuidle_driver *drv, 173 struct cpuidle_device *dev); 174 void (*disable) (struct cpuidle_driver *drv, 175 struct cpuidle_device *dev); 176 177 int (*select) (struct cpuidle_driver *drv, 178 struct cpuidle_device *dev); 179 void (*reflect) (struct cpuidle_device *dev, int index); 180 181 struct module *owner; 182}; 183 184#ifdef CONFIG_CPU_IDLE 185 186extern int cpuidle_register_governor(struct cpuidle_governor *gov); 187extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 188 189#ifdef CONFIG_INTEL_IDLE 190extern int intel_idle_cpu_init(int cpu); 191#else 192static inline int intel_idle_cpu_init(int cpu) { return -1; } 193#endif 194 195#else 196static inline int intel_idle_cpu_init(int cpu) { return -1; } 197 198static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 199{return 0;} 200static 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