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 #define CPUIDLE_STATE_DISABLED_BY_USER BIT(0) 33 #define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1) 34 35 struct cpuidle_state_usage { 36 unsigned long long disable; 37 unsigned long long usage; 38 u64 time_ns; 39 unsigned long long above; /* Number of times it's been too deep */ 40 unsigned long long below; /* Number of times it's been too shallow */ 41 #ifdef CONFIG_SUSPEND 42 unsigned long long s2idle_usage; 43 unsigned long long s2idle_time; /* in US */ 44 #endif 45 }; 46 47 struct cpuidle_state { 48 char name[CPUIDLE_NAME_LEN]; 49 char desc[CPUIDLE_DESC_LEN]; 50 51 u64 exit_latency_ns; 52 u64 target_residency_ns; 53 unsigned int flags; 54 unsigned int exit_latency; /* in US */ 55 int power_usage; /* in mW */ 56 unsigned int target_residency; /* in US */ 57 58 int (*enter) (struct cpuidle_device *dev, 59 struct cpuidle_driver *drv, 60 int index); 61 62 int (*enter_dead) (struct cpuidle_device *dev, int index); 63 64 /* 65 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping 66 * suspended, so it must not re-enable interrupts at any point (even 67 * temporarily) or attempt to change states of clock event devices. 68 * 69 * This callback may point to the same function as ->enter if all of 70 * the above requirements are met by it. 71 */ 72 int (*enter_s2idle)(struct cpuidle_device *dev, 73 struct cpuidle_driver *drv, 74 int index); 75 }; 76 77 /* Idle State Flags */ 78 #define CPUIDLE_FLAG_NONE (0x00) 79 #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */ 80 #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ 81 #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ 82 #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ 83 #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ 84 85 struct cpuidle_device_kobj; 86 struct cpuidle_state_kobj; 87 struct cpuidle_driver_kobj; 88 89 struct cpuidle_device { 90 unsigned int registered:1; 91 unsigned int enabled:1; 92 unsigned int poll_time_limit:1; 93 unsigned int cpu; 94 ktime_t next_hrtimer; 95 96 int last_state_idx; 97 u64 last_residency_ns; 98 u64 poll_limit_ns; 99 u64 forced_idle_latency_limit_ns; 100 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 101 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 102 struct cpuidle_driver_kobj *kobj_driver; 103 struct cpuidle_device_kobj *kobj_dev; 104 struct list_head device_list; 105 106 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 107 cpumask_t coupled_cpus; 108 struct cpuidle_coupled *coupled; 109 #endif 110 }; 111 112 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 113 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 114 115 /**************************** 116 * CPUIDLE DRIVER INTERFACE * 117 ****************************/ 118 119 struct cpuidle_driver { 120 const char *name; 121 struct module *owner; 122 123 /* used by the cpuidle framework to setup the broadcast timer */ 124 unsigned int bctimer:1; 125 /* states array must be ordered in decreasing power consumption */ 126 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 127 int state_count; 128 int safe_state_index; 129 130 /* the driver handles the cpus in cpumask */ 131 struct cpumask *cpumask; 132 133 /* preferred governor to switch at register time */ 134 const char *governor; 135 }; 136 137 #ifdef CONFIG_CPU_IDLE 138 extern void disable_cpuidle(void); 139 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 140 struct cpuidle_device *dev); 141 142 extern int cpuidle_select(struct cpuidle_driver *drv, 143 struct cpuidle_device *dev, 144 bool *stop_tick); 145 extern int cpuidle_enter(struct cpuidle_driver *drv, 146 struct cpuidle_device *dev, int index); 147 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 148 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, 149 struct cpuidle_device *dev); 150 151 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 152 extern struct cpuidle_driver *cpuidle_get_driver(void); 153 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, 154 bool disable); 155 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 156 extern int cpuidle_register_device(struct cpuidle_device *dev); 157 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 158 extern int cpuidle_register(struct cpuidle_driver *drv, 159 const struct cpumask *const coupled_cpus); 160 extern void cpuidle_unregister(struct cpuidle_driver *drv); 161 extern void cpuidle_pause_and_lock(void); 162 extern void cpuidle_resume_and_unlock(void); 163 extern void cpuidle_pause(void); 164 extern void cpuidle_resume(void); 165 extern int cpuidle_enable_device(struct cpuidle_device *dev); 166 extern void cpuidle_disable_device(struct cpuidle_device *dev); 167 extern int cpuidle_play_dead(void); 168 169 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 170 static inline struct cpuidle_device *cpuidle_get_device(void) 171 {return __this_cpu_read(cpuidle_devices); } 172 #else 173 static inline void disable_cpuidle(void) { } 174 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 175 struct cpuidle_device *dev) 176 {return true; } 177 static inline int cpuidle_select(struct cpuidle_driver *drv, 178 struct cpuidle_device *dev, bool *stop_tick) 179 {return -ENODEV; } 180 static inline int cpuidle_enter(struct cpuidle_driver *drv, 181 struct cpuidle_device *dev, int index) 182 {return -ENODEV; } 183 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 184 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 185 struct cpuidle_device *dev) 186 {return 0; } 187 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 188 {return -ENODEV; } 189 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 190 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, 191 int idx, bool disable) { } 192 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 193 static inline int cpuidle_register_device(struct cpuidle_device *dev) 194 {return -ENODEV; } 195 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 196 static inline int cpuidle_register(struct cpuidle_driver *drv, 197 const struct cpumask *const coupled_cpus) 198 {return -ENODEV; } 199 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 200 static inline void cpuidle_pause_and_lock(void) { } 201 static inline void cpuidle_resume_and_unlock(void) { } 202 static inline void cpuidle_pause(void) { } 203 static inline void cpuidle_resume(void) { } 204 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 205 {return -ENODEV; } 206 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 207 static inline int cpuidle_play_dead(void) {return -ENODEV; } 208 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 209 struct cpuidle_device *dev) {return NULL; } 210 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 211 #endif 212 213 #ifdef CONFIG_CPU_IDLE 214 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 215 struct cpuidle_device *dev, 216 u64 latency_limit_ns); 217 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 218 struct cpuidle_device *dev); 219 extern void cpuidle_use_deepest_state(u64 latency_limit_ns); 220 #else 221 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 222 struct cpuidle_device *dev, 223 u64 latency_limit_ns) 224 {return -ENODEV; } 225 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 226 struct cpuidle_device *dev) 227 {return -ENODEV; } 228 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) 229 { 230 } 231 #endif 232 233 /* kernel/sched/idle.c */ 234 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 235 extern void default_idle_call(void); 236 237 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 238 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 239 #else 240 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 241 { 242 } 243 #endif 244 245 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 246 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 247 #else 248 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 249 #endif 250 251 /****************************** 252 * CPUIDLE GOVERNOR INTERFACE * 253 ******************************/ 254 255 struct cpuidle_governor { 256 char name[CPUIDLE_NAME_LEN]; 257 struct list_head governor_list; 258 unsigned int rating; 259 260 int (*enable) (struct cpuidle_driver *drv, 261 struct cpuidle_device *dev); 262 void (*disable) (struct cpuidle_driver *drv, 263 struct cpuidle_device *dev); 264 265 int (*select) (struct cpuidle_driver *drv, 266 struct cpuidle_device *dev, 267 bool *stop_tick); 268 void (*reflect) (struct cpuidle_device *dev, int index); 269 }; 270 271 #ifdef CONFIG_CPU_IDLE 272 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 273 extern s64 cpuidle_governor_latency_req(unsigned int cpu); 274 #else 275 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 276 {return 0;} 277 #endif 278 279 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ 280 idx, \ 281 state, \ 282 is_retention) \ 283 ({ \ 284 int __ret = 0; \ 285 \ 286 if (!idx) { \ 287 cpu_do_idle(); \ 288 return idx; \ 289 } \ 290 \ 291 if (!is_retention) \ 292 __ret = cpu_pm_enter(); \ 293 if (!__ret) { \ 294 __ret = low_level_idle_enter(state); \ 295 if (!is_retention) \ 296 cpu_pm_exit(); \ 297 } \ 298 \ 299 __ret ? -1 : idx; \ 300 }) 301 302 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 303 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0) 304 305 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ 306 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1) 307 308 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ 309 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0) 310 311 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \ 312 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1) 313 314 #endif /* _LINUX_CPUIDLE_H */ 315