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 * CPUs execute ->enter_freeze with the local tick or entire timekeeping 56 * suspended, so it must not re-enable interrupts at any point (even 57 * temporarily) or attempt to change states of clock event devices. 58 */ 59 void (*enter_freeze) (struct cpuidle_device *dev, 60 struct cpuidle_driver *drv, 61 int index); 62 }; 63 64 /* Idle State Flags */ 65 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 66 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 67 68 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 69 70 struct cpuidle_device_kobj; 71 struct cpuidle_state_kobj; 72 struct cpuidle_driver_kobj; 73 74 struct cpuidle_device { 75 unsigned int registered:1; 76 unsigned int enabled:1; 77 unsigned int cpu; 78 79 int last_residency; 80 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 81 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 82 struct cpuidle_driver_kobj *kobj_driver; 83 struct cpuidle_device_kobj *kobj_dev; 84 struct list_head device_list; 85 86 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 87 cpumask_t coupled_cpus; 88 struct cpuidle_coupled *coupled; 89 #endif 90 }; 91 92 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 93 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 94 95 /** 96 * cpuidle_get_last_residency - retrieves the last state's residency time 97 * @dev: the target CPU 98 */ 99 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 100 { 101 return dev->last_residency; 102 } 103 104 105 /**************************** 106 * CPUIDLE DRIVER INTERFACE * 107 ****************************/ 108 109 struct cpuidle_driver { 110 const char *name; 111 struct module *owner; 112 int refcnt; 113 114 /* used by the cpuidle framework to setup the broadcast timer */ 115 unsigned int bctimer:1; 116 /* states array must be ordered in decreasing power consumption */ 117 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 118 int state_count; 119 int safe_state_index; 120 121 /* the driver handles the cpus in cpumask */ 122 struct cpumask *cpumask; 123 }; 124 125 #ifdef CONFIG_CPU_IDLE 126 extern void disable_cpuidle(void); 127 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 128 struct cpuidle_device *dev); 129 130 extern int cpuidle_select(struct cpuidle_driver *drv, 131 struct cpuidle_device *dev); 132 extern int cpuidle_enter(struct cpuidle_driver *drv, 133 struct cpuidle_device *dev, int index); 134 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 135 136 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 137 extern struct cpuidle_driver *cpuidle_get_driver(void); 138 extern struct cpuidle_driver *cpuidle_driver_ref(void); 139 extern void cpuidle_driver_unref(void); 140 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 141 extern int cpuidle_register_device(struct cpuidle_device *dev); 142 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 143 extern int cpuidle_register(struct cpuidle_driver *drv, 144 const struct cpumask *const coupled_cpus); 145 extern void cpuidle_unregister(struct cpuidle_driver *drv); 146 extern void cpuidle_pause_and_lock(void); 147 extern void cpuidle_resume_and_unlock(void); 148 extern void cpuidle_pause(void); 149 extern void cpuidle_resume(void); 150 extern int cpuidle_enable_device(struct cpuidle_device *dev); 151 extern void cpuidle_disable_device(struct cpuidle_device *dev); 152 extern int cpuidle_play_dead(void); 153 154 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 155 #else 156 static inline void disable_cpuidle(void) { } 157 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 158 struct cpuidle_device *dev) 159 {return true; } 160 static inline int cpuidle_select(struct cpuidle_driver *drv, 161 struct cpuidle_device *dev) 162 {return -ENODEV; } 163 static inline int cpuidle_enter(struct cpuidle_driver *drv, 164 struct cpuidle_device *dev, int index) 165 {return -ENODEV; } 166 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 167 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 168 {return -ENODEV; } 169 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 170 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 171 static inline void cpuidle_driver_unref(void) {} 172 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 173 static inline int cpuidle_register_device(struct cpuidle_device *dev) 174 {return -ENODEV; } 175 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 176 static inline int cpuidle_register(struct cpuidle_driver *drv, 177 const struct cpumask *const coupled_cpus) 178 {return -ENODEV; } 179 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 180 static inline void cpuidle_pause_and_lock(void) { } 181 static inline void cpuidle_resume_and_unlock(void) { } 182 static inline void cpuidle_pause(void) { } 183 static inline void cpuidle_resume(void) { } 184 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 185 {return -ENODEV; } 186 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 187 static inline int cpuidle_play_dead(void) {return -ENODEV; } 188 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 189 struct cpuidle_device *dev) {return NULL; } 190 #endif 191 192 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND) 193 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 194 struct cpuidle_device *dev); 195 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, 196 struct cpuidle_device *dev); 197 #else 198 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 199 struct cpuidle_device *dev) 200 {return -ENODEV; } 201 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv, 202 struct cpuidle_device *dev) 203 {return -ENODEV; } 204 #endif 205 206 /* kernel/sched/idle.c */ 207 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 208 extern void default_idle_call(void); 209 210 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 211 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 212 #else 213 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 214 { 215 } 216 #endif 217 218 /****************************** 219 * CPUIDLE GOVERNOR INTERFACE * 220 ******************************/ 221 222 struct cpuidle_governor { 223 char name[CPUIDLE_NAME_LEN]; 224 struct list_head governor_list; 225 unsigned int rating; 226 227 int (*enable) (struct cpuidle_driver *drv, 228 struct cpuidle_device *dev); 229 void (*disable) (struct cpuidle_driver *drv, 230 struct cpuidle_device *dev); 231 232 int (*select) (struct cpuidle_driver *drv, 233 struct cpuidle_device *dev); 234 void (*reflect) (struct cpuidle_device *dev, int index); 235 236 struct module *owner; 237 }; 238 239 #ifdef CONFIG_CPU_IDLE 240 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 241 #else 242 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 243 {return 0;} 244 #endif 245 246 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 247 #define CPUIDLE_DRIVER_STATE_START 1 248 #else 249 #define CPUIDLE_DRIVER_STATE_START 0 250 #endif 251 252 #endif /* _LINUX_CPUIDLE_H */ 253