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 use_deepest_state:1; 78 unsigned int cpu; 79 80 int last_residency; 81 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 82 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 83 struct cpuidle_driver_kobj *kobj_driver; 84 struct cpuidle_device_kobj *kobj_dev; 85 struct list_head device_list; 86 87 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 88 cpumask_t coupled_cpus; 89 struct cpuidle_coupled *coupled; 90 #endif 91 }; 92 93 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 94 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 95 96 /** 97 * cpuidle_get_last_residency - retrieves the last state's residency time 98 * @dev: the target CPU 99 */ 100 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 101 { 102 return dev->last_residency; 103 } 104 105 106 /**************************** 107 * CPUIDLE DRIVER INTERFACE * 108 ****************************/ 109 110 struct cpuidle_driver { 111 const char *name; 112 struct module *owner; 113 int refcnt; 114 115 /* used by the cpuidle framework to setup the broadcast timer */ 116 unsigned int bctimer:1; 117 /* states array must be ordered in decreasing power consumption */ 118 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 119 int state_count; 120 int safe_state_index; 121 122 /* the driver handles the cpus in cpumask */ 123 struct cpumask *cpumask; 124 }; 125 126 #ifdef CONFIG_CPU_IDLE 127 extern void disable_cpuidle(void); 128 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 129 struct cpuidle_device *dev); 130 131 extern int cpuidle_select(struct cpuidle_driver *drv, 132 struct cpuidle_device *dev); 133 extern int cpuidle_enter(struct cpuidle_driver *drv, 134 struct cpuidle_device *dev, int index); 135 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 136 137 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 138 extern struct cpuidle_driver *cpuidle_get_driver(void); 139 extern struct cpuidle_driver *cpuidle_driver_ref(void); 140 extern void cpuidle_driver_unref(void); 141 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 142 extern int cpuidle_register_device(struct cpuidle_device *dev); 143 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 144 extern int cpuidle_register(struct cpuidle_driver *drv, 145 const struct cpumask *const coupled_cpus); 146 extern void cpuidle_unregister(struct cpuidle_driver *drv); 147 extern void cpuidle_pause_and_lock(void); 148 extern void cpuidle_resume_and_unlock(void); 149 extern void cpuidle_pause(void); 150 extern void cpuidle_resume(void); 151 extern int cpuidle_enable_device(struct cpuidle_device *dev); 152 extern void cpuidle_disable_device(struct cpuidle_device *dev); 153 extern int cpuidle_play_dead(void); 154 155 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 156 static inline struct cpuidle_device *cpuidle_get_device(void) 157 {return __this_cpu_read(cpuidle_devices); } 158 #else 159 static inline void disable_cpuidle(void) { } 160 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 161 struct cpuidle_device *dev) 162 {return true; } 163 static inline int cpuidle_select(struct cpuidle_driver *drv, 164 struct cpuidle_device *dev) 165 {return -ENODEV; } 166 static inline int cpuidle_enter(struct cpuidle_driver *drv, 167 struct cpuidle_device *dev, int index) 168 {return -ENODEV; } 169 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 170 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 171 {return -ENODEV; } 172 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 173 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 174 static inline void cpuidle_driver_unref(void) {} 175 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 176 static inline int cpuidle_register_device(struct cpuidle_device *dev) 177 {return -ENODEV; } 178 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 179 static inline int cpuidle_register(struct cpuidle_driver *drv, 180 const struct cpumask *const coupled_cpus) 181 {return -ENODEV; } 182 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 183 static inline void cpuidle_pause_and_lock(void) { } 184 static inline void cpuidle_resume_and_unlock(void) { } 185 static inline void cpuidle_pause(void) { } 186 static inline void cpuidle_resume(void) { } 187 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 188 {return -ENODEV; } 189 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 190 static inline int cpuidle_play_dead(void) {return -ENODEV; } 191 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 192 struct cpuidle_device *dev) {return NULL; } 193 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 194 #endif 195 196 #ifdef CONFIG_CPU_IDLE 197 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 198 struct cpuidle_device *dev); 199 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, 200 struct cpuidle_device *dev); 201 extern void cpuidle_use_deepest_state(bool enable); 202 #else 203 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 204 struct cpuidle_device *dev) 205 {return -ENODEV; } 206 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv, 207 struct cpuidle_device *dev) 208 {return -ENODEV; } 209 static inline void cpuidle_use_deepest_state(bool enable) 210 { 211 } 212 #endif 213 214 /* kernel/sched/idle.c */ 215 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 216 extern void default_idle_call(void); 217 218 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 219 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 220 #else 221 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 222 { 223 } 224 #endif 225 226 /****************************** 227 * CPUIDLE GOVERNOR INTERFACE * 228 ******************************/ 229 230 struct cpuidle_governor { 231 char name[CPUIDLE_NAME_LEN]; 232 struct list_head governor_list; 233 unsigned int rating; 234 235 int (*enable) (struct cpuidle_driver *drv, 236 struct cpuidle_device *dev); 237 void (*disable) (struct cpuidle_driver *drv, 238 struct cpuidle_device *dev); 239 240 int (*select) (struct cpuidle_driver *drv, 241 struct cpuidle_device *dev); 242 void (*reflect) (struct cpuidle_device *dev, int index); 243 }; 244 245 #ifdef CONFIG_CPU_IDLE 246 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 247 #else 248 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 249 {return 0;} 250 #endif 251 252 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 253 #define CPUIDLE_DRIVER_STATE_START 1 254 #else 255 #define CPUIDLE_DRIVER_STATE_START 0 256 #endif 257 258 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 259 ({ \ 260 int __ret; \ 261 \ 262 if (!idx) { \ 263 cpu_do_idle(); \ 264 return idx; \ 265 } \ 266 \ 267 __ret = cpu_pm_enter(); \ 268 if (!__ret) { \ 269 __ret = low_level_idle_enter(idx); \ 270 cpu_pm_exit(); \ 271 } \ 272 \ 273 __ret ? -1 : idx; \ 274 }) 275 276 #endif /* _LINUX_CPUIDLE_H */ 277