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 void (*enter_s2idle) (struct cpuidle_device *dev, 70 struct cpuidle_driver *drv, 71 int index); 72 }; 73 74 /* Idle State Flags */ 75 #define CPUIDLE_FLAG_NONE (0x00) 76 #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */ 77 #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ 78 #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ 79 #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ 80 81 struct cpuidle_device_kobj; 82 struct cpuidle_state_kobj; 83 struct cpuidle_driver_kobj; 84 85 struct cpuidle_device { 86 unsigned int registered:1; 87 unsigned int enabled:1; 88 unsigned int poll_time_limit:1; 89 unsigned int cpu; 90 ktime_t next_hrtimer; 91 92 int last_state_idx; 93 u64 last_residency_ns; 94 u64 poll_limit_ns; 95 u64 forced_idle_latency_limit_ns; 96 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 97 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 98 struct cpuidle_driver_kobj *kobj_driver; 99 struct cpuidle_device_kobj *kobj_dev; 100 struct list_head device_list; 101 102 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 103 cpumask_t coupled_cpus; 104 struct cpuidle_coupled *coupled; 105 #endif 106 }; 107 108 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 109 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 110 111 /**************************** 112 * CPUIDLE DRIVER INTERFACE * 113 ****************************/ 114 115 struct cpuidle_driver { 116 const char *name; 117 struct module *owner; 118 119 /* used by the cpuidle framework to setup the broadcast timer */ 120 unsigned int bctimer:1; 121 /* states array must be ordered in decreasing power consumption */ 122 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 123 int state_count; 124 int safe_state_index; 125 126 /* the driver handles the cpus in cpumask */ 127 struct cpumask *cpumask; 128 129 /* preferred governor to switch at register time */ 130 const char *governor; 131 }; 132 133 #ifdef CONFIG_CPU_IDLE 134 extern void disable_cpuidle(void); 135 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 136 struct cpuidle_device *dev); 137 138 extern int cpuidle_select(struct cpuidle_driver *drv, 139 struct cpuidle_device *dev, 140 bool *stop_tick); 141 extern int cpuidle_enter(struct cpuidle_driver *drv, 142 struct cpuidle_device *dev, int index); 143 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 144 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, 145 struct cpuidle_device *dev); 146 147 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 148 extern struct cpuidle_driver *cpuidle_get_driver(void); 149 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, 150 bool disable); 151 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 152 extern int cpuidle_register_device(struct cpuidle_device *dev); 153 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 154 extern int cpuidle_register(struct cpuidle_driver *drv, 155 const struct cpumask *const coupled_cpus); 156 extern void cpuidle_unregister(struct cpuidle_driver *drv); 157 extern void cpuidle_pause_and_lock(void); 158 extern void cpuidle_resume_and_unlock(void); 159 extern void cpuidle_pause(void); 160 extern void cpuidle_resume(void); 161 extern int cpuidle_enable_device(struct cpuidle_device *dev); 162 extern void cpuidle_disable_device(struct cpuidle_device *dev); 163 extern int cpuidle_play_dead(void); 164 165 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 166 static inline struct cpuidle_device *cpuidle_get_device(void) 167 {return __this_cpu_read(cpuidle_devices); } 168 #else 169 static inline void disable_cpuidle(void) { } 170 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 171 struct cpuidle_device *dev) 172 {return true; } 173 static inline int cpuidle_select(struct cpuidle_driver *drv, 174 struct cpuidle_device *dev, bool *stop_tick) 175 {return -ENODEV; } 176 static inline int cpuidle_enter(struct cpuidle_driver *drv, 177 struct cpuidle_device *dev, int index) 178 {return -ENODEV; } 179 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 180 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 181 struct cpuidle_device *dev) 182 {return 0; } 183 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 184 {return -ENODEV; } 185 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 186 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, 187 int idx, bool disable) { } 188 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 189 static inline int cpuidle_register_device(struct cpuidle_device *dev) 190 {return -ENODEV; } 191 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 192 static inline int cpuidle_register(struct cpuidle_driver *drv, 193 const struct cpumask *const coupled_cpus) 194 {return -ENODEV; } 195 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 196 static inline void cpuidle_pause_and_lock(void) { } 197 static inline void cpuidle_resume_and_unlock(void) { } 198 static inline void cpuidle_pause(void) { } 199 static inline void cpuidle_resume(void) { } 200 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 201 {return -ENODEV; } 202 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 203 static inline int cpuidle_play_dead(void) {return -ENODEV; } 204 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 205 struct cpuidle_device *dev) {return NULL; } 206 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 207 #endif 208 209 #ifdef CONFIG_CPU_IDLE 210 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 211 struct cpuidle_device *dev, 212 u64 latency_limit_ns); 213 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 214 struct cpuidle_device *dev); 215 extern void cpuidle_use_deepest_state(u64 latency_limit_ns); 216 #else 217 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 218 struct cpuidle_device *dev, 219 u64 latency_limit_ns) 220 {return -ENODEV; } 221 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 222 struct cpuidle_device *dev) 223 {return -ENODEV; } 224 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) 225 { 226 } 227 #endif 228 229 /* kernel/sched/idle.c */ 230 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 231 extern void default_idle_call(void); 232 233 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 234 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 235 #else 236 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 237 { 238 } 239 #endif 240 241 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 242 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 243 #else 244 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 245 #endif 246 247 /****************************** 248 * CPUIDLE GOVERNOR INTERFACE * 249 ******************************/ 250 251 struct cpuidle_governor { 252 char name[CPUIDLE_NAME_LEN]; 253 struct list_head governor_list; 254 unsigned int rating; 255 256 int (*enable) (struct cpuidle_driver *drv, 257 struct cpuidle_device *dev); 258 void (*disable) (struct cpuidle_driver *drv, 259 struct cpuidle_device *dev); 260 261 int (*select) (struct cpuidle_driver *drv, 262 struct cpuidle_device *dev, 263 bool *stop_tick); 264 void (*reflect) (struct cpuidle_device *dev, int index); 265 }; 266 267 #ifdef CONFIG_CPU_IDLE 268 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 269 extern s64 cpuidle_governor_latency_req(unsigned int cpu); 270 #else 271 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 272 {return 0;} 273 #endif 274 275 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ 276 idx, \ 277 state, \ 278 is_retention) \ 279 ({ \ 280 int __ret = 0; \ 281 \ 282 if (!idx) { \ 283 cpu_do_idle(); \ 284 return idx; \ 285 } \ 286 \ 287 if (!is_retention) \ 288 __ret = cpu_pm_enter(); \ 289 if (!__ret) { \ 290 __ret = low_level_idle_enter(state); \ 291 if (!is_retention) \ 292 cpu_pm_exit(); \ 293 } \ 294 \ 295 __ret ? -1 : idx; \ 296 }) 297 298 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 299 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0) 300 301 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ 302 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1) 303 304 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ 305 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0) 306 307 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \ 308 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1) 309 310 #endif /* _LINUX_CPUIDLE_H */ 311