1 /* 2 * cpuidle.h - a generic framework for CPU idle power management 3 * 4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 5 * Shaohua Li <shaohua.li@intel.com> 6 * Adam Belay <abelay@novell.com> 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 #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ 81 82 struct cpuidle_device_kobj; 83 struct cpuidle_state_kobj; 84 struct cpuidle_driver_kobj; 85 86 struct cpuidle_device { 87 unsigned int registered:1; 88 unsigned int enabled:1; 89 unsigned int poll_time_limit:1; 90 unsigned int cpu; 91 ktime_t next_hrtimer; 92 93 int last_state_idx; 94 u64 last_residency_ns; 95 u64 poll_limit_ns; 96 u64 forced_idle_latency_limit_ns; 97 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 98 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 99 struct cpuidle_driver_kobj *kobj_driver; 100 struct cpuidle_device_kobj *kobj_dev; 101 struct list_head device_list; 102 103 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 104 cpumask_t coupled_cpus; 105 struct cpuidle_coupled *coupled; 106 #endif 107 }; 108 109 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 110 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 111 112 /**************************** 113 * CPUIDLE DRIVER INTERFACE * 114 ****************************/ 115 116 struct cpuidle_driver { 117 const char *name; 118 struct module *owner; 119 120 /* used by the cpuidle framework to setup the broadcast timer */ 121 unsigned int bctimer:1; 122 /* states array must be ordered in decreasing power consumption */ 123 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 124 int state_count; 125 int safe_state_index; 126 127 /* the driver handles the cpus in cpumask */ 128 struct cpumask *cpumask; 129 130 /* preferred governor to switch at register time */ 131 const char *governor; 132 }; 133 134 #ifdef CONFIG_CPU_IDLE 135 extern void disable_cpuidle(void); 136 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 137 struct cpuidle_device *dev); 138 139 extern int cpuidle_select(struct cpuidle_driver *drv, 140 struct cpuidle_device *dev, 141 bool *stop_tick); 142 extern int cpuidle_enter(struct cpuidle_driver *drv, 143 struct cpuidle_device *dev, int index); 144 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 145 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, 146 struct cpuidle_device *dev); 147 148 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 149 extern struct cpuidle_driver *cpuidle_get_driver(void); 150 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, 151 bool disable); 152 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 153 extern int cpuidle_register_device(struct cpuidle_device *dev); 154 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 155 extern int cpuidle_register(struct cpuidle_driver *drv, 156 const struct cpumask *const coupled_cpus); 157 extern void cpuidle_unregister(struct cpuidle_driver *drv); 158 extern void cpuidle_pause_and_lock(void); 159 extern void cpuidle_resume_and_unlock(void); 160 extern void cpuidle_pause(void); 161 extern void cpuidle_resume(void); 162 extern int cpuidle_enable_device(struct cpuidle_device *dev); 163 extern void cpuidle_disable_device(struct cpuidle_device *dev); 164 extern int cpuidle_play_dead(void); 165 166 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 167 static inline struct cpuidle_device *cpuidle_get_device(void) 168 {return __this_cpu_read(cpuidle_devices); } 169 #else 170 static inline void disable_cpuidle(void) { } 171 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 172 struct cpuidle_device *dev) 173 {return true; } 174 static inline int cpuidle_select(struct cpuidle_driver *drv, 175 struct cpuidle_device *dev, bool *stop_tick) 176 {return -ENODEV; } 177 static inline int cpuidle_enter(struct cpuidle_driver *drv, 178 struct cpuidle_device *dev, int index) 179 {return -ENODEV; } 180 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 181 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 182 struct cpuidle_device *dev) 183 {return 0; } 184 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 185 {return -ENODEV; } 186 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 187 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, 188 int idx, bool disable) { } 189 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 190 static inline int cpuidle_register_device(struct cpuidle_device *dev) 191 {return -ENODEV; } 192 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 193 static inline int cpuidle_register(struct cpuidle_driver *drv, 194 const struct cpumask *const coupled_cpus) 195 {return -ENODEV; } 196 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 197 static inline void cpuidle_pause_and_lock(void) { } 198 static inline void cpuidle_resume_and_unlock(void) { } 199 static inline void cpuidle_pause(void) { } 200 static inline void cpuidle_resume(void) { } 201 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 202 {return -ENODEV; } 203 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 204 static inline int cpuidle_play_dead(void) {return -ENODEV; } 205 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 206 struct cpuidle_device *dev) {return NULL; } 207 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 208 #endif 209 210 #ifdef CONFIG_CPU_IDLE 211 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 212 struct cpuidle_device *dev, 213 u64 latency_limit_ns); 214 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 215 struct cpuidle_device *dev); 216 extern void cpuidle_use_deepest_state(u64 latency_limit_ns); 217 #else 218 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 219 struct cpuidle_device *dev, 220 u64 latency_limit_ns) 221 {return -ENODEV; } 222 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 223 struct cpuidle_device *dev) 224 {return -ENODEV; } 225 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) 226 { 227 } 228 #endif 229 230 /* kernel/sched/idle.c */ 231 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 232 extern void default_idle_call(void); 233 234 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 235 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 236 #else 237 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 238 { 239 } 240 #endif 241 242 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 243 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 244 #else 245 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 246 #endif 247 248 /****************************** 249 * CPUIDLE GOVERNOR INTERFACE * 250 ******************************/ 251 252 struct cpuidle_governor { 253 char name[CPUIDLE_NAME_LEN]; 254 struct list_head governor_list; 255 unsigned int rating; 256 257 int (*enable) (struct cpuidle_driver *drv, 258 struct cpuidle_device *dev); 259 void (*disable) (struct cpuidle_driver *drv, 260 struct cpuidle_device *dev); 261 262 int (*select) (struct cpuidle_driver *drv, 263 struct cpuidle_device *dev, 264 bool *stop_tick); 265 void (*reflect) (struct cpuidle_device *dev, int index); 266 }; 267 268 #ifdef CONFIG_CPU_IDLE 269 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 270 extern s64 cpuidle_governor_latency_req(unsigned int cpu); 271 #else 272 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 273 {return 0;} 274 #endif 275 276 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ 277 idx, \ 278 state, \ 279 is_retention) \ 280 ({ \ 281 int __ret = 0; \ 282 \ 283 if (!idx) { \ 284 cpu_do_idle(); \ 285 return idx; \ 286 } \ 287 \ 288 if (!is_retention) \ 289 __ret = cpu_pm_enter(); \ 290 if (!__ret) { \ 291 __ret = low_level_idle_enter(state); \ 292 if (!is_retention) \ 293 cpu_pm_exit(); \ 294 } \ 295 \ 296 __ret ? -1 : idx; \ 297 }) 298 299 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 300 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0) 301 302 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ 303 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1) 304 305 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ 306 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0) 307 308 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \ 309 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1) 310 311 #endif /* _LINUX_CPUIDLE_H */ 312