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 87 int last_residency; 88 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 90 struct cpuidle_driver_kobj *kobj_driver; 91 struct cpuidle_device_kobj *kobj_dev; 92 struct list_head device_list; 93 94 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 95 cpumask_t coupled_cpus; 96 struct cpuidle_coupled *coupled; 97 #endif 98 }; 99 100 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 101 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 102 103 /**************************** 104 * CPUIDLE DRIVER INTERFACE * 105 ****************************/ 106 107 struct cpuidle_driver { 108 const char *name; 109 struct module *owner; 110 int refcnt; 111 112 /* used by the cpuidle framework to setup the broadcast timer */ 113 unsigned int bctimer:1; 114 /* states array must be ordered in decreasing power consumption */ 115 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 116 int state_count; 117 int safe_state_index; 118 119 /* the driver handles the cpus in cpumask */ 120 struct cpumask *cpumask; 121 }; 122 123 #ifdef CONFIG_CPU_IDLE 124 extern void disable_cpuidle(void); 125 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 126 struct cpuidle_device *dev); 127 128 extern int cpuidle_select(struct cpuidle_driver *drv, 129 struct cpuidle_device *dev, 130 bool *stop_tick); 131 extern int cpuidle_enter(struct cpuidle_driver *drv, 132 struct cpuidle_device *dev, int index); 133 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 134 135 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 136 extern struct cpuidle_driver *cpuidle_get_driver(void); 137 extern struct cpuidle_driver *cpuidle_driver_ref(void); 138 extern void cpuidle_driver_unref(void); 139 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 140 extern int cpuidle_register_device(struct cpuidle_device *dev); 141 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 142 extern int cpuidle_register(struct cpuidle_driver *drv, 143 const struct cpumask *const coupled_cpus); 144 extern void cpuidle_unregister(struct cpuidle_driver *drv); 145 extern void cpuidle_pause_and_lock(void); 146 extern void cpuidle_resume_and_unlock(void); 147 extern void cpuidle_pause(void); 148 extern void cpuidle_resume(void); 149 extern int cpuidle_enable_device(struct cpuidle_device *dev); 150 extern void cpuidle_disable_device(struct cpuidle_device *dev); 151 extern int cpuidle_play_dead(void); 152 153 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 154 static inline struct cpuidle_device *cpuidle_get_device(void) 155 {return __this_cpu_read(cpuidle_devices); } 156 #else 157 static inline void disable_cpuidle(void) { } 158 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 159 struct cpuidle_device *dev) 160 {return true; } 161 static inline int cpuidle_select(struct cpuidle_driver *drv, 162 struct cpuidle_device *dev, bool *stop_tick) 163 {return -ENODEV; } 164 static inline int cpuidle_enter(struct cpuidle_driver *drv, 165 struct cpuidle_device *dev, int index) 166 {return -ENODEV; } 167 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 168 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 169 {return -ENODEV; } 170 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 171 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 172 static inline void cpuidle_driver_unref(void) {} 173 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 174 static inline int cpuidle_register_device(struct cpuidle_device *dev) 175 {return -ENODEV; } 176 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 177 static inline int cpuidle_register(struct cpuidle_driver *drv, 178 const struct cpumask *const coupled_cpus) 179 {return -ENODEV; } 180 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 181 static inline void cpuidle_pause_and_lock(void) { } 182 static inline void cpuidle_resume_and_unlock(void) { } 183 static inline void cpuidle_pause(void) { } 184 static inline void cpuidle_resume(void) { } 185 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 186 {return -ENODEV; } 187 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 188 static inline int cpuidle_play_dead(void) {return -ENODEV; } 189 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 190 struct cpuidle_device *dev) {return NULL; } 191 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 192 #endif 193 194 #ifdef CONFIG_CPU_IDLE 195 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 196 struct cpuidle_device *dev); 197 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 198 struct cpuidle_device *dev); 199 extern void cpuidle_use_deepest_state(bool enable); 200 #else 201 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 202 struct cpuidle_device *dev) 203 {return -ENODEV; } 204 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 205 struct cpuidle_device *dev) 206 {return -ENODEV; } 207 static inline void cpuidle_use_deepest_state(bool enable) 208 { 209 } 210 #endif 211 212 /* kernel/sched/idle.c */ 213 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 214 extern void default_idle_call(void); 215 216 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 217 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 218 #else 219 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 220 { 221 } 222 #endif 223 224 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) 225 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 226 #else 227 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 228 #endif 229 230 /****************************** 231 * CPUIDLE GOVERNOR INTERFACE * 232 ******************************/ 233 234 struct cpuidle_governor { 235 char name[CPUIDLE_NAME_LEN]; 236 struct list_head governor_list; 237 unsigned int rating; 238 239 int (*enable) (struct cpuidle_driver *drv, 240 struct cpuidle_device *dev); 241 void (*disable) (struct cpuidle_driver *drv, 242 struct cpuidle_device *dev); 243 244 int (*select) (struct cpuidle_driver *drv, 245 struct cpuidle_device *dev, 246 bool *stop_tick); 247 void (*reflect) (struct cpuidle_device *dev, int index); 248 }; 249 250 #ifdef CONFIG_CPU_IDLE 251 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 252 extern int cpuidle_governor_latency_req(unsigned int cpu); 253 #else 254 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 255 {return 0;} 256 #endif 257 258 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \ 259 ({ \ 260 int __ret = 0; \ 261 \ 262 if (!idx) { \ 263 cpu_do_idle(); \ 264 return idx; \ 265 } \ 266 \ 267 if (!is_retention) \ 268 __ret = cpu_pm_enter(); \ 269 if (!__ret) { \ 270 __ret = low_level_idle_enter(idx); \ 271 if (!is_retention) \ 272 cpu_pm_exit(); \ 273 } \ 274 \ 275 __ret ? -1 : idx; \ 276 }) 277 278 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 279 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0) 280 281 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ 282 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1) 283 284 #endif /* _LINUX_CPUIDLE_H */ 285