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 #ifdef CONFIG_SUSPEND 37 unsigned long long s2idle_usage; 38 unsigned long long s2idle_time; /* in US */ 39 #endif 40 }; 41 42 struct cpuidle_state { 43 char name[CPUIDLE_NAME_LEN]; 44 char desc[CPUIDLE_DESC_LEN]; 45 46 unsigned int flags; 47 unsigned int exit_latency; /* in US */ 48 int power_usage; /* in mW */ 49 unsigned int target_residency; /* in US */ 50 bool disabled; /* disabled on all CPUs */ 51 52 int (*enter) (struct cpuidle_device *dev, 53 struct cpuidle_driver *drv, 54 int index); 55 56 int (*enter_dead) (struct cpuidle_device *dev, int index); 57 58 /* 59 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping 60 * suspended, so it must not re-enable interrupts at any point (even 61 * temporarily) or attempt to change states of clock event devices. 62 */ 63 void (*enter_s2idle) (struct cpuidle_device *dev, 64 struct cpuidle_driver *drv, 65 int index); 66 }; 67 68 /* Idle State Flags */ 69 #define CPUIDLE_FLAG_NONE (0x00) 70 #define CPUIDLE_FLAG_POLLING (0x01) /* polling state */ 71 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 72 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 73 74 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 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 cpu; 85 86 int last_residency; 87 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 88 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 89 struct cpuidle_driver_kobj *kobj_driver; 90 struct cpuidle_device_kobj *kobj_dev; 91 struct list_head device_list; 92 93 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 94 cpumask_t coupled_cpus; 95 struct cpuidle_coupled *coupled; 96 #endif 97 }; 98 99 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 100 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 101 102 /** 103 * cpuidle_get_last_residency - retrieves the last state's residency time 104 * @dev: the target CPU 105 */ 106 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 107 { 108 return dev->last_residency; 109 } 110 111 112 /**************************** 113 * CPUIDLE DRIVER INTERFACE * 114 ****************************/ 115 116 struct cpuidle_driver { 117 const char *name; 118 struct module *owner; 119 int refcnt; 120 121 /* used by the cpuidle framework to setup the broadcast timer */ 122 unsigned int bctimer:1; 123 /* states array must be ordered in decreasing power consumption */ 124 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 125 int state_count; 126 int safe_state_index; 127 128 /* the driver handles the cpus in cpumask */ 129 struct cpumask *cpumask; 130 }; 131 132 #ifdef CONFIG_CPU_IDLE 133 extern void disable_cpuidle(void); 134 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 135 struct cpuidle_device *dev); 136 137 extern int cpuidle_select(struct cpuidle_driver *drv, 138 struct cpuidle_device *dev, 139 bool *stop_tick); 140 extern int cpuidle_enter(struct cpuidle_driver *drv, 141 struct cpuidle_device *dev, int index); 142 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 143 144 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 145 extern struct cpuidle_driver *cpuidle_get_driver(void); 146 extern struct cpuidle_driver *cpuidle_driver_ref(void); 147 extern void cpuidle_driver_unref(void); 148 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 149 extern int cpuidle_register_device(struct cpuidle_device *dev); 150 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 151 extern int cpuidle_register(struct cpuidle_driver *drv, 152 const struct cpumask *const coupled_cpus); 153 extern void cpuidle_unregister(struct cpuidle_driver *drv); 154 extern void cpuidle_pause_and_lock(void); 155 extern void cpuidle_resume_and_unlock(void); 156 extern void cpuidle_pause(void); 157 extern void cpuidle_resume(void); 158 extern int cpuidle_enable_device(struct cpuidle_device *dev); 159 extern void cpuidle_disable_device(struct cpuidle_device *dev); 160 extern int cpuidle_play_dead(void); 161 162 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 163 static inline struct cpuidle_device *cpuidle_get_device(void) 164 {return __this_cpu_read(cpuidle_devices); } 165 #else 166 static inline void disable_cpuidle(void) { } 167 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 168 struct cpuidle_device *dev) 169 {return true; } 170 static inline int cpuidle_select(struct cpuidle_driver *drv, 171 struct cpuidle_device *dev, bool *stop_tick) 172 {return -ENODEV; } 173 static inline int cpuidle_enter(struct cpuidle_driver *drv, 174 struct cpuidle_device *dev, int index) 175 {return -ENODEV; } 176 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 177 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 178 {return -ENODEV; } 179 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 180 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 181 static inline void cpuidle_driver_unref(void) {} 182 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 183 static inline int cpuidle_register_device(struct cpuidle_device *dev) 184 {return -ENODEV; } 185 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 186 static inline int cpuidle_register(struct cpuidle_driver *drv, 187 const struct cpumask *const coupled_cpus) 188 {return -ENODEV; } 189 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 190 static inline void cpuidle_pause_and_lock(void) { } 191 static inline void cpuidle_resume_and_unlock(void) { } 192 static inline void cpuidle_pause(void) { } 193 static inline void cpuidle_resume(void) { } 194 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 195 {return -ENODEV; } 196 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 197 static inline int cpuidle_play_dead(void) {return -ENODEV; } 198 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 199 struct cpuidle_device *dev) {return NULL; } 200 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 201 #endif 202 203 #ifdef CONFIG_CPU_IDLE 204 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 205 struct cpuidle_device *dev); 206 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 207 struct cpuidle_device *dev); 208 extern void cpuidle_use_deepest_state(bool enable); 209 #else 210 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 211 struct cpuidle_device *dev) 212 {return -ENODEV; } 213 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 214 struct cpuidle_device *dev) 215 {return -ENODEV; } 216 static inline void cpuidle_use_deepest_state(bool enable) 217 { 218 } 219 #endif 220 221 /* kernel/sched/idle.c */ 222 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 223 extern void default_idle_call(void); 224 225 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 226 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 227 #else 228 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 229 { 230 } 231 #endif 232 233 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 234 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 235 #else 236 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 237 #endif 238 239 /****************************** 240 * CPUIDLE GOVERNOR INTERFACE * 241 ******************************/ 242 243 struct cpuidle_governor { 244 char name[CPUIDLE_NAME_LEN]; 245 struct list_head governor_list; 246 unsigned int rating; 247 248 int (*enable) (struct cpuidle_driver *drv, 249 struct cpuidle_device *dev); 250 void (*disable) (struct cpuidle_driver *drv, 251 struct cpuidle_device *dev); 252 253 int (*select) (struct cpuidle_driver *drv, 254 struct cpuidle_device *dev, 255 bool *stop_tick); 256 void (*reflect) (struct cpuidle_device *dev, int index); 257 }; 258 259 #ifdef CONFIG_CPU_IDLE 260 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 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