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 unsigned long long above; /* Number of times it's been too deep */ 37 unsigned long long below; /* Number of times it's been too shallow */ 38 #ifdef CONFIG_SUSPEND 39 unsigned long long s2idle_usage; 40 unsigned long long s2idle_time; /* in US */ 41 #endif 42 }; 43 44 struct cpuidle_state { 45 char name[CPUIDLE_NAME_LEN]; 46 char desc[CPUIDLE_DESC_LEN]; 47 48 unsigned int flags; 49 unsigned int exit_latency; /* in US */ 50 int power_usage; /* in mW */ 51 unsigned int target_residency; /* in US */ 52 bool disabled; /* disabled on all CPUs */ 53 54 int (*enter) (struct cpuidle_device *dev, 55 struct cpuidle_driver *drv, 56 int index); 57 58 int (*enter_dead) (struct cpuidle_device *dev, int index); 59 60 /* 61 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping 62 * suspended, so it must not re-enable interrupts at any point (even 63 * temporarily) or attempt to change states of clock event devices. 64 */ 65 void (*enter_s2idle) (struct cpuidle_device *dev, 66 struct cpuidle_driver *drv, 67 int index); 68 }; 69 70 /* Idle State Flags */ 71 #define CPUIDLE_FLAG_NONE (0x00) 72 #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */ 73 #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ 74 #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ 75 76 struct cpuidle_device_kobj; 77 struct cpuidle_state_kobj; 78 struct cpuidle_driver_kobj; 79 80 struct cpuidle_device { 81 unsigned int registered:1; 82 unsigned int enabled:1; 83 unsigned int use_deepest_state:1; 84 unsigned int poll_time_limit:1; 85 unsigned int cpu; 86 ktime_t next_hrtimer; 87 88 int last_state_idx; 89 int last_residency; 90 u64 poll_limit_ns; 91 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 92 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 93 struct cpuidle_driver_kobj *kobj_driver; 94 struct cpuidle_device_kobj *kobj_dev; 95 struct list_head device_list; 96 97 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 98 cpumask_t coupled_cpus; 99 struct cpuidle_coupled *coupled; 100 #endif 101 }; 102 103 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 104 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 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 bool *stop_tick); 134 extern int cpuidle_enter(struct cpuidle_driver *drv, 135 struct cpuidle_device *dev, int index); 136 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 137 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, 138 struct cpuidle_device *dev); 139 140 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 141 extern struct cpuidle_driver *cpuidle_get_driver(void); 142 extern struct cpuidle_driver *cpuidle_driver_ref(void); 143 extern void cpuidle_driver_unref(void); 144 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 145 extern int cpuidle_register_device(struct cpuidle_device *dev); 146 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 147 extern int cpuidle_register(struct cpuidle_driver *drv, 148 const struct cpumask *const coupled_cpus); 149 extern void cpuidle_unregister(struct cpuidle_driver *drv); 150 extern void cpuidle_pause_and_lock(void); 151 extern void cpuidle_resume_and_unlock(void); 152 extern void cpuidle_pause(void); 153 extern void cpuidle_resume(void); 154 extern int cpuidle_enable_device(struct cpuidle_device *dev); 155 extern void cpuidle_disable_device(struct cpuidle_device *dev); 156 extern int cpuidle_play_dead(void); 157 158 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 159 static inline struct cpuidle_device *cpuidle_get_device(void) 160 {return __this_cpu_read(cpuidle_devices); } 161 #else 162 static inline void disable_cpuidle(void) { } 163 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 164 struct cpuidle_device *dev) 165 {return true; } 166 static inline int cpuidle_select(struct cpuidle_driver *drv, 167 struct cpuidle_device *dev, bool *stop_tick) 168 {return -ENODEV; } 169 static inline int cpuidle_enter(struct cpuidle_driver *drv, 170 struct cpuidle_device *dev, int index) 171 {return -ENODEV; } 172 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 173 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 174 struct cpuidle_device *dev) 175 {return 0; } 176 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 177 {return -ENODEV; } 178 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 179 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 180 static inline void cpuidle_driver_unref(void) {} 181 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 182 static inline int cpuidle_register_device(struct cpuidle_device *dev) 183 {return -ENODEV; } 184 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 185 static inline int cpuidle_register(struct cpuidle_driver *drv, 186 const struct cpumask *const coupled_cpus) 187 {return -ENODEV; } 188 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 189 static inline void cpuidle_pause_and_lock(void) { } 190 static inline void cpuidle_resume_and_unlock(void) { } 191 static inline void cpuidle_pause(void) { } 192 static inline void cpuidle_resume(void) { } 193 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 194 {return -ENODEV; } 195 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 196 static inline int cpuidle_play_dead(void) {return -ENODEV; } 197 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 198 struct cpuidle_device *dev) {return NULL; } 199 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 200 #endif 201 202 #ifdef CONFIG_CPU_IDLE 203 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 204 struct cpuidle_device *dev); 205 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 206 struct cpuidle_device *dev); 207 extern void cpuidle_use_deepest_state(bool enable); 208 #else 209 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 210 struct cpuidle_device *dev) 211 {return -ENODEV; } 212 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 213 struct cpuidle_device *dev) 214 {return -ENODEV; } 215 static inline void cpuidle_use_deepest_state(bool enable) 216 { 217 } 218 #endif 219 220 /* kernel/sched/idle.c */ 221 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 222 extern void default_idle_call(void); 223 224 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 225 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 226 #else 227 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 228 { 229 } 230 #endif 231 232 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 233 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 234 #else 235 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 236 #endif 237 238 /****************************** 239 * CPUIDLE GOVERNOR INTERFACE * 240 ******************************/ 241 242 struct cpuidle_governor { 243 char name[CPUIDLE_NAME_LEN]; 244 struct list_head governor_list; 245 unsigned int rating; 246 247 int (*enable) (struct cpuidle_driver *drv, 248 struct cpuidle_device *dev); 249 void (*disable) (struct cpuidle_driver *drv, 250 struct cpuidle_device *dev); 251 252 int (*select) (struct cpuidle_driver *drv, 253 struct cpuidle_device *dev, 254 bool *stop_tick); 255 void (*reflect) (struct cpuidle_device *dev, int index); 256 }; 257 258 #ifdef CONFIG_CPU_IDLE 259 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 260 extern int cpuidle_governor_latency_req(unsigned int cpu); 261 #else 262 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 263 {return 0;} 264 #endif 265 266 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \ 267 ({ \ 268 int __ret = 0; \ 269 \ 270 if (!idx) { \ 271 cpu_do_idle(); \ 272 return idx; \ 273 } \ 274 \ 275 if (!is_retention) \ 276 __ret = cpu_pm_enter(); \ 277 if (!__ret) { \ 278 __ret = low_level_idle_enter(idx); \ 279 if (!is_retention) \ 280 cpu_pm_exit(); \ 281 } \ 282 \ 283 __ret ? -1 : idx; \ 284 }) 285 286 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 287 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0) 288 289 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ 290 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1) 291 292 #endif /* _LINUX_CPUIDLE_H */ 293