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_s2idle 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_s2idle) (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_POLLING (0x01) /* polling state */ 67 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 68 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 69 70 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 71 72 struct cpuidle_device_kobj; 73 struct cpuidle_state_kobj; 74 struct cpuidle_driver_kobj; 75 76 struct cpuidle_device { 77 unsigned int registered:1; 78 unsigned int enabled:1; 79 unsigned int use_deepest_state:1; 80 unsigned int cpu; 81 82 int last_residency; 83 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 84 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 85 struct cpuidle_driver_kobj *kobj_driver; 86 struct cpuidle_device_kobj *kobj_dev; 87 struct list_head device_list; 88 89 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 90 cpumask_t coupled_cpus; 91 struct cpuidle_coupled *coupled; 92 #endif 93 }; 94 95 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 96 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 97 98 /** 99 * cpuidle_get_last_residency - retrieves the last state's residency time 100 * @dev: the target CPU 101 */ 102 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 103 { 104 return dev->last_residency; 105 } 106 107 108 /**************************** 109 * CPUIDLE DRIVER INTERFACE * 110 ****************************/ 111 112 struct cpuidle_driver { 113 const char *name; 114 struct module *owner; 115 int refcnt; 116 117 /* used by the cpuidle framework to setup the broadcast timer */ 118 unsigned int bctimer:1; 119 /* states array must be ordered in decreasing power consumption */ 120 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 121 int state_count; 122 int safe_state_index; 123 124 /* the driver handles the cpus in cpumask */ 125 struct cpumask *cpumask; 126 }; 127 128 #ifdef CONFIG_CPU_IDLE 129 extern void disable_cpuidle(void); 130 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 131 struct cpuidle_device *dev); 132 133 extern int cpuidle_select(struct cpuidle_driver *drv, 134 struct cpuidle_device *dev); 135 extern int cpuidle_enter(struct cpuidle_driver *drv, 136 struct cpuidle_device *dev, int index); 137 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 138 139 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 140 extern struct cpuidle_driver *cpuidle_get_driver(void); 141 extern struct cpuidle_driver *cpuidle_driver_ref(void); 142 extern void cpuidle_driver_unref(void); 143 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 144 extern int cpuidle_register_device(struct cpuidle_device *dev); 145 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 146 extern int cpuidle_register(struct cpuidle_driver *drv, 147 const struct cpumask *const coupled_cpus); 148 extern void cpuidle_unregister(struct cpuidle_driver *drv); 149 extern void cpuidle_pause_and_lock(void); 150 extern void cpuidle_resume_and_unlock(void); 151 extern void cpuidle_pause(void); 152 extern void cpuidle_resume(void); 153 extern int cpuidle_enable_device(struct cpuidle_device *dev); 154 extern void cpuidle_disable_device(struct cpuidle_device *dev); 155 extern int cpuidle_play_dead(void); 156 157 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 158 static inline struct cpuidle_device *cpuidle_get_device(void) 159 {return __this_cpu_read(cpuidle_devices); } 160 #else 161 static inline void disable_cpuidle(void) { } 162 static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 163 struct cpuidle_device *dev) 164 {return true; } 165 static inline int cpuidle_select(struct cpuidle_driver *drv, 166 struct cpuidle_device *dev) 167 {return -ENODEV; } 168 static inline int cpuidle_enter(struct cpuidle_driver *drv, 169 struct cpuidle_device *dev, int index) 170 {return -ENODEV; } 171 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 172 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 173 {return -ENODEV; } 174 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 175 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 176 static inline void cpuidle_driver_unref(void) {} 177 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 178 static inline int cpuidle_register_device(struct cpuidle_device *dev) 179 {return -ENODEV; } 180 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 181 static inline int cpuidle_register(struct cpuidle_driver *drv, 182 const struct cpumask *const coupled_cpus) 183 {return -ENODEV; } 184 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 185 static inline void cpuidle_pause_and_lock(void) { } 186 static inline void cpuidle_resume_and_unlock(void) { } 187 static inline void cpuidle_pause(void) { } 188 static inline void cpuidle_resume(void) { } 189 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 190 {return -ENODEV; } 191 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 192 static inline int cpuidle_play_dead(void) {return -ENODEV; } 193 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 194 struct cpuidle_device *dev) {return NULL; } 195 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 196 #endif 197 198 #ifdef CONFIG_CPU_IDLE 199 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 200 struct cpuidle_device *dev); 201 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 202 struct cpuidle_device *dev); 203 extern void cpuidle_use_deepest_state(bool enable); 204 #else 205 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 206 struct cpuidle_device *dev) 207 {return -ENODEV; } 208 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 209 struct cpuidle_device *dev) 210 {return -ENODEV; } 211 static inline void cpuidle_use_deepest_state(bool enable) 212 { 213 } 214 #endif 215 216 /* kernel/sched/idle.c */ 217 extern void sched_idle_set_state(struct cpuidle_state *idle_state); 218 extern void default_idle_call(void); 219 220 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 221 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 222 #else 223 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 224 { 225 } 226 #endif 227 228 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 229 void cpuidle_poll_state_init(struct cpuidle_driver *drv); 230 #else 231 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 232 #endif 233 234 /****************************** 235 * CPUIDLE GOVERNOR INTERFACE * 236 ******************************/ 237 238 struct cpuidle_governor { 239 char name[CPUIDLE_NAME_LEN]; 240 struct list_head governor_list; 241 unsigned int rating; 242 243 int (*enable) (struct cpuidle_driver *drv, 244 struct cpuidle_device *dev); 245 void (*disable) (struct cpuidle_driver *drv, 246 struct cpuidle_device *dev); 247 248 int (*select) (struct cpuidle_driver *drv, 249 struct cpuidle_device *dev); 250 void (*reflect) (struct cpuidle_device *dev, int index); 251 }; 252 253 #ifdef CONFIG_CPU_IDLE 254 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 255 #else 256 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 257 {return 0;} 258 #endif 259 260 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ 261 ({ \ 262 int __ret; \ 263 \ 264 if (!idx) { \ 265 cpu_do_idle(); \ 266 return idx; \ 267 } \ 268 \ 269 __ret = cpu_pm_enter(); \ 270 if (!__ret) { \ 271 __ret = low_level_idle_enter(idx); \ 272 cpu_pm_exit(); \ 273 } \ 274 \ 275 __ret ? -1 : idx; \ 276 }) 277 278 #endif /* _LINUX_CPUIDLE_H */ 279