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/hrtimer.h> 17 18 #define CPUIDLE_STATE_MAX 10 19 #define CPUIDLE_NAME_LEN 16 20 #define CPUIDLE_DESC_LEN 32 21 22 struct module; 23 24 struct cpuidle_device; 25 struct cpuidle_driver; 26 27 28 /**************************** 29 * CPUIDLE DEVICE INTERFACE * 30 ****************************/ 31 32 struct cpuidle_state_usage { 33 unsigned long long disable; 34 unsigned long long usage; 35 unsigned long long time; /* in US */ 36 }; 37 38 struct cpuidle_state { 39 char name[CPUIDLE_NAME_LEN]; 40 char desc[CPUIDLE_DESC_LEN]; 41 42 unsigned int flags; 43 unsigned int exit_latency; /* in US */ 44 int power_usage; /* in mW */ 45 unsigned int target_residency; /* in US */ 46 bool disabled; /* disabled on all CPUs */ 47 48 int (*enter) (struct cpuidle_device *dev, 49 struct cpuidle_driver *drv, 50 int index); 51 52 int (*enter_dead) (struct cpuidle_device *dev, int index); 53 }; 54 55 /* Idle State Flags */ 56 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 57 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 58 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 59 60 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 61 62 struct cpuidle_device_kobj; 63 struct cpuidle_state_kobj; 64 struct cpuidle_driver_kobj; 65 66 struct cpuidle_device { 67 unsigned int registered:1; 68 unsigned int enabled:1; 69 unsigned int cpu; 70 71 int last_residency; 72 int state_count; 73 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 74 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 75 struct cpuidle_driver_kobj *kobj_driver; 76 struct cpuidle_device_kobj *kobj_dev; 77 struct list_head device_list; 78 79 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 80 int safe_state_index; 81 cpumask_t coupled_cpus; 82 struct cpuidle_coupled *coupled; 83 #endif 84 }; 85 86 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 87 88 /** 89 * cpuidle_get_last_residency - retrieves the last state's residency time 90 * @dev: the target CPU 91 * 92 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 93 */ 94 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 95 { 96 return dev->last_residency; 97 } 98 99 100 /**************************** 101 * CPUIDLE DRIVER INTERFACE * 102 ****************************/ 103 104 struct cpuidle_driver { 105 const char *name; 106 struct module *owner; 107 int refcnt; 108 109 /* used by the cpuidle framework to setup the broadcast timer */ 110 unsigned int bctimer:1; 111 /* states array must be ordered in decreasing power consumption */ 112 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 113 int state_count; 114 int safe_state_index; 115 116 /* the driver handles the cpus in cpumask */ 117 struct cpumask *cpumask; 118 }; 119 120 #ifdef CONFIG_CPU_IDLE 121 extern void disable_cpuidle(void); 122 123 extern int cpuidle_enabled(struct cpuidle_driver *drv, 124 struct cpuidle_device *dev); 125 extern int cpuidle_select(struct cpuidle_driver *drv, 126 struct cpuidle_device *dev); 127 extern int cpuidle_enter(struct cpuidle_driver *drv, 128 struct cpuidle_device *dev, int index); 129 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 130 131 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 132 extern struct cpuidle_driver *cpuidle_get_driver(void); 133 extern struct cpuidle_driver *cpuidle_driver_ref(void); 134 extern void cpuidle_driver_unref(void); 135 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 136 extern int cpuidle_register_device(struct cpuidle_device *dev); 137 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 138 extern int cpuidle_register(struct cpuidle_driver *drv, 139 const struct cpumask *const coupled_cpus); 140 extern void cpuidle_unregister(struct cpuidle_driver *drv); 141 extern void cpuidle_pause_and_lock(void); 142 extern void cpuidle_resume_and_unlock(void); 143 extern void cpuidle_pause(void); 144 extern void cpuidle_resume(void); 145 extern int cpuidle_enable_device(struct cpuidle_device *dev); 146 extern void cpuidle_disable_device(struct cpuidle_device *dev); 147 extern int cpuidle_play_dead(void); 148 149 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 150 #else 151 static inline void disable_cpuidle(void) { } 152 static inline int cpuidle_enabled(struct cpuidle_driver *drv, 153 struct cpuidle_device *dev) 154 {return -ENODEV; } 155 static inline int cpuidle_select(struct cpuidle_driver *drv, 156 struct cpuidle_device *dev) 157 {return -ENODEV; } 158 static inline int cpuidle_enter(struct cpuidle_driver *drv, 159 struct cpuidle_device *dev, int index) 160 {return -ENODEV; } 161 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 162 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 163 {return -ENODEV; } 164 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 165 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 166 static inline void cpuidle_driver_unref(void) {} 167 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 168 static inline int cpuidle_register_device(struct cpuidle_device *dev) 169 {return -ENODEV; } 170 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 171 static inline int cpuidle_register(struct cpuidle_driver *drv, 172 const struct cpumask *const coupled_cpus) 173 {return -ENODEV; } 174 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 175 static inline void cpuidle_pause_and_lock(void) { } 176 static inline void cpuidle_resume_and_unlock(void) { } 177 static inline void cpuidle_pause(void) { } 178 static inline void cpuidle_resume(void) { } 179 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 180 {return -ENODEV; } 181 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 182 static inline int cpuidle_play_dead(void) {return -ENODEV; } 183 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 184 struct cpuidle_device *dev) {return NULL; } 185 #endif 186 187 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 188 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 189 #else 190 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 191 { 192 } 193 #endif 194 195 /****************************** 196 * CPUIDLE GOVERNOR INTERFACE * 197 ******************************/ 198 199 struct cpuidle_governor { 200 char name[CPUIDLE_NAME_LEN]; 201 struct list_head governor_list; 202 unsigned int rating; 203 204 int (*enable) (struct cpuidle_driver *drv, 205 struct cpuidle_device *dev); 206 void (*disable) (struct cpuidle_driver *drv, 207 struct cpuidle_device *dev); 208 209 int (*select) (struct cpuidle_driver *drv, 210 struct cpuidle_device *dev); 211 void (*reflect) (struct cpuidle_device *dev, int index); 212 213 struct module *owner; 214 }; 215 216 #ifdef CONFIG_CPU_IDLE 217 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 218 #else 219 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 220 {return 0;} 221 #endif 222 223 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 224 #define CPUIDLE_DRIVER_STATE_START 1 225 #else 226 #define CPUIDLE_DRIVER_STATE_START 0 227 #endif 228 229 #endif /* _LINUX_CPUIDLE_H */ 230