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 }; 37 38 struct cpuidle_state { 39 char name[CPUIDLE_NAME_LEN]; 40 char desc[CPUIDLE_DESC_LEN]; 41 42 unsigned int flags; 43 unsigned int exit_latency; /* in US */ 44 int power_usage; /* in mW */ 45 unsigned int target_residency; /* in US */ 46 bool disabled; /* disabled on all CPUs */ 47 48 int (*enter) (struct cpuidle_device *dev, 49 struct cpuidle_driver *drv, 50 int index); 51 52 int (*enter_dead) (struct cpuidle_device *dev, int index); 53 54 /* 55 * CPUs execute ->enter_freeze with the local tick or entire timekeeping 56 * suspended, so it must not re-enable interrupts at any point (even 57 * temporarily) or attempt to change states of clock event devices. 58 */ 59 void (*enter_freeze) (struct cpuidle_device *dev, 60 struct cpuidle_driver *drv, 61 int index); 62 }; 63 64 /* Idle State Flags */ 65 #define CPUIDLE_FLAG_NONE (0x00) 66 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 67 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 68 69 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 70 71 struct cpuidle_device_kobj; 72 struct cpuidle_state_kobj; 73 struct cpuidle_driver_kobj; 74 75 struct cpuidle_device { 76 unsigned int registered:1; 77 unsigned int enabled:1; 78 unsigned int use_deepest_state:1; 79 unsigned int cpu; 80 81 int last_residency; 82 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 83 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 84 struct cpuidle_driver_kobj *kobj_driver; 85 struct cpuidle_device_kobj *kobj_dev; 86 struct list_head device_list; 87 88 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 89 cpumask_t coupled_cpus; 90 struct cpuidle_coupled *coupled; 91 #endif 92 }; 93 94 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 95 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 96 97 /** 98 * cpuidle_get_last_residency - retrieves the last state's residency time 99 * @dev: the target CPU 100 */ 101 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 102 { 103 return dev->last_residency; 104 } 105 106 107 /**************************** 108 * CPUIDLE DRIVER INTERFACE * 109 ****************************/ 110 111 struct cpuidle_driver { 112 const char *name; 113 struct module *owner; 114 int refcnt; 115 116 /* used by the cpuidle framework to setup the broadcast timer */ 117 unsigned int bctimer:1; 118 /* states array must be ordered in decreasing power consumption */ 119 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 120 int state_count; 121 int safe_state_index; 122 123 /* the driver handles the cpus in cpumask */ 124 struct cpumask *cpumask; 125 }; 126 127 #ifdef CONFIG_CPU_IDLE 128 extern void disable_cpuidle(void); 129 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 130 struct cpuidle_device *dev); 131 132 extern int cpuidle_select(struct cpuidle_driver *drv, 133 struct cpuidle_device *dev); 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); 137 138 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 139 extern struct cpuidle_driver *cpuidle_get_driver(void); 140 extern struct cpuidle_driver *cpuidle_driver_ref(void); 141 extern void cpuidle_driver_unref(void); 142 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 143 extern int cpuidle_register_device(struct cpuidle_device *dev); 144 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 145 extern int cpuidle_register(struct cpuidle_driver *drv, 146 const struct cpumask *const coupled_cpus); 147 extern void cpuidle_unregister(struct cpuidle_driver *drv); 148 extern void cpuidle_pause_and_lock(void); 149 extern void cpuidle_resume_and_unlock(void); 150 extern void cpuidle_pause(void); 151 extern void cpuidle_resume(void); 152 extern int cpuidle_enable_device(struct cpuidle_device *dev); 153 extern void cpuidle_disable_device(struct cpuidle_device *dev); 154 extern int cpuidle_play_dead(void); 155 156 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 157 static inline struct cpuidle_device *cpuidle_get_device(void) 158 {return __this_cpu_read(cpuidle_devices); } 159 #else 160 static inline void disable_cpuidle(void) { } 161 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 162 struct cpuidle_device *dev) 163 {return true; } 164 static inline int cpuidle_select(struct cpuidle_driver *drv, 165 struct cpuidle_device *dev) 166 {return -ENODEV; } 167 static inline int cpuidle_enter(struct cpuidle_driver *drv, 168 struct cpuidle_device *dev, int index) 169 {return -ENODEV; } 170 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 171 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 172 {return -ENODEV; } 173 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 174 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 175 static inline void cpuidle_driver_unref(void) {} 176 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 177 static inline int cpuidle_register_device(struct cpuidle_device *dev) 178 {return -ENODEV; } 179 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 180 static inline int cpuidle_register(struct cpuidle_driver *drv, 181 const struct cpumask *const coupled_cpus) 182 {return -ENODEV; } 183 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 184 static inline void cpuidle_pause_and_lock(void) { } 185 static inline void cpuidle_resume_and_unlock(void) { } 186 static inline void cpuidle_pause(void) { } 187 static inline void cpuidle_resume(void) { } 188 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 189 {return -ENODEV; } 190 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 191 static inline int cpuidle_play_dead(void) {return -ENODEV; } 192 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 193 struct cpuidle_device *dev) {return NULL; } 194 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 195 #endif 196 197 #ifdef CONFIG_CPU_IDLE 198 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 199 struct cpuidle_device *dev); 200 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, 201 struct cpuidle_device *dev); 202 extern void cpuidle_use_deepest_state(bool enable); 203 #else 204 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 205 struct cpuidle_device *dev) 206 {return -ENODEV; } 207 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv, 208 struct cpuidle_device *dev) 209 {return -ENODEV; } 210 static inline void cpuidle_use_deepest_state(bool enable) 211 { 212 } 213 #endif 214 215 /* kernel/sched/idle.c */ 216 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 217 extern void default_idle_call(void); 218 219 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 220 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 221 #else 222 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 223 { 224 } 225 #endif 226 227 /****************************** 228 * CPUIDLE GOVERNOR INTERFACE * 229 ******************************/ 230 231 struct cpuidle_governor { 232 char name[CPUIDLE_NAME_LEN]; 233 struct list_head governor_list; 234 unsigned int rating; 235 236 int (*enable) (struct cpuidle_driver *drv, 237 struct cpuidle_device *dev); 238 void (*disable) (struct cpuidle_driver *drv, 239 struct cpuidle_device *dev); 240 241 int (*select) (struct cpuidle_driver *drv, 242 struct cpuidle_device *dev); 243 void (*reflect) (struct cpuidle_device *dev, int index); 244 }; 245 246 #ifdef CONFIG_CPU_IDLE 247 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 248 #else 249 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 250 {return 0;} 251 #endif 252 253 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 254 #define CPUIDLE_DRIVER_STATE_START 1 255 #else 256 #define CPUIDLE_DRIVER_STATE_START 0 257 #endif 258 259 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 260 ({ \ 261 int __ret; \ 262 \ 263 if (!idx) { \ 264 cpu_do_idle(); \ 265 return idx; \ 266 } \ 267 \ 268 __ret = cpu_pm_enter(); \ 269 if (!__ret) { \ 270 __ret = low_level_idle_enter(idx); \ 271 cpu_pm_exit(); \ 272 } \ 273 \ 274 __ret ? -1 : idx; \ 275 }) 276 277 #endif /* _LINUX_CPUIDLE_H */ 278