| 1 | /* |
| 2 | * cpuidle.h - a generic framework for CPU idle power management |
| 3 | * |
| 4 | * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> |
| 5 | * Shaohua Li <shaohua.li@intel.com> |
| 6 | * Adam Belay <abelay@novell.com> |
| 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 | #include <linux/context_tracking.h> |
| 18 | |
| 19 | #define CPUIDLE_STATE_MAX 10 |
| 20 | #define CPUIDLE_NAME_LEN 16 |
| 21 | #define CPUIDLE_DESC_LEN 32 |
| 22 | |
| 23 | struct module; |
| 24 | |
| 25 | struct cpuidle_device; |
| 26 | struct cpuidle_driver; |
| 27 | |
| 28 | |
| 29 | /**************************** |
| 30 | * CPUIDLE DEVICE INTERFACE * |
| 31 | ****************************/ |
| 32 | |
| 33 | #define CPUIDLE_STATE_DISABLED_BY_USER BIT(0) |
| 34 | #define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1) |
| 35 | |
| 36 | struct cpuidle_state_usage { |
| 37 | unsigned long long disable; |
| 38 | unsigned long long usage; |
| 39 | u64 time_ns; |
| 40 | unsigned long long above; /* Number of times it's been too deep */ |
| 41 | unsigned long long below; /* Number of times it's been too shallow */ |
| 42 | unsigned long long rejected; /* Number of times idle entry was rejected */ |
| 43 | #ifdef CONFIG_SUSPEND |
| 44 | unsigned long long s2idle_usage; |
| 45 | unsigned long long s2idle_time; /* in US */ |
| 46 | #endif |
| 47 | }; |
| 48 | |
| 49 | struct cpuidle_state { |
| 50 | char name[CPUIDLE_NAME_LEN]; |
| 51 | char desc[CPUIDLE_DESC_LEN]; |
| 52 | |
| 53 | s64 exit_latency_ns; |
| 54 | s64 target_residency_ns; |
| 55 | unsigned int flags; |
| 56 | unsigned int exit_latency; /* in US */ |
| 57 | int power_usage; /* in mW */ |
| 58 | unsigned int target_residency; /* in US */ |
| 59 | |
| 60 | int (*enter) (struct cpuidle_device *dev, |
| 61 | struct cpuidle_driver *drv, |
| 62 | int index); |
| 63 | |
| 64 | int (*enter_dead) (struct cpuidle_device *dev, int index); |
| 65 | |
| 66 | /* |
| 67 | * CPUs execute ->enter_s2idle with the local tick or entire timekeeping |
| 68 | * suspended, so it must not re-enable interrupts at any point (even |
| 69 | * temporarily) or attempt to change states of clock event devices. |
| 70 | * |
| 71 | * This callback may point to the same function as ->enter if all of |
| 72 | * the above requirements are met by it. |
| 73 | */ |
| 74 | int (*enter_s2idle)(struct cpuidle_device *dev, |
| 75 | struct cpuidle_driver *drv, |
| 76 | int index); |
| 77 | }; |
| 78 | |
| 79 | /* Idle State Flags */ |
| 80 | #define CPUIDLE_FLAG_NONE (0x00) |
| 81 | #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */ |
| 82 | #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ |
| 83 | #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ |
| 84 | #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ |
| 85 | #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ |
| 86 | #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */ |
| 87 | #define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */ |
| 88 | |
| 89 | struct cpuidle_device_kobj; |
| 90 | struct cpuidle_state_kobj; |
| 91 | struct cpuidle_driver_kobj; |
| 92 | |
| 93 | struct cpuidle_device { |
| 94 | unsigned int registered:1; |
| 95 | unsigned int enabled:1; |
| 96 | unsigned int poll_time_limit:1; |
| 97 | unsigned int cpu; |
| 98 | ktime_t next_hrtimer; |
| 99 | |
| 100 | int last_state_idx; |
| 101 | u64 last_residency_ns; |
| 102 | u64 poll_limit_ns; |
| 103 | u64 forced_idle_latency_limit_ns; |
| 104 | struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; |
| 105 | struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; |
| 106 | struct cpuidle_driver_kobj *kobj_driver; |
| 107 | struct cpuidle_device_kobj *kobj_dev; |
| 108 | struct list_head device_list; |
| 109 | |
| 110 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED |
| 111 | cpumask_t coupled_cpus; |
| 112 | struct cpuidle_coupled *coupled; |
| 113 | #endif |
| 114 | }; |
| 115 | |
| 116 | DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); |
| 117 | DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
| 118 | |
| 119 | static __always_inline void ct_cpuidle_enter(void) |
| 120 | { |
| 121 | lockdep_assert_irqs_disabled(); |
| 122 | /* |
| 123 | * Idle is allowed to (temporary) enable IRQs. It |
| 124 | * will return with IRQs disabled. |
| 125 | * |
| 126 | * Trace IRQs enable here, then switch off RCU, and have |
| 127 | * arch_cpu_idle() use raw_local_irq_enable(). Note that |
| 128 | * ct_idle_enter() relies on lockdep IRQ state, so switch that |
| 129 | * last -- this is very similar to the entry code. |
| 130 | */ |
| 131 | trace_hardirqs_on_prepare(); |
| 132 | lockdep_hardirqs_on_prepare(); |
| 133 | instrumentation_end(); |
| 134 | ct_idle_enter(); |
| 135 | lockdep_hardirqs_on(_RET_IP_); |
| 136 | } |
| 137 | |
| 138 | static __always_inline void ct_cpuidle_exit(void) |
| 139 | { |
| 140 | /* |
| 141 | * Carefully undo the above. |
| 142 | */ |
| 143 | lockdep_hardirqs_off(_RET_IP_); |
| 144 | ct_idle_exit(); |
| 145 | instrumentation_begin(); |
| 146 | } |
| 147 | |
| 148 | /**************************** |
| 149 | * CPUIDLE DRIVER INTERFACE * |
| 150 | ****************************/ |
| 151 | |
| 152 | struct cpuidle_driver { |
| 153 | const char *name; |
| 154 | struct module *owner; |
| 155 | |
| 156 | /* used by the cpuidle framework to setup the broadcast timer */ |
| 157 | unsigned int bctimer:1; |
| 158 | /* states array must be ordered in decreasing power consumption */ |
| 159 | struct cpuidle_state states[CPUIDLE_STATE_MAX]; |
| 160 | int state_count; |
| 161 | int safe_state_index; |
| 162 | |
| 163 | /* the driver handles the cpus in cpumask */ |
| 164 | struct cpumask *cpumask; |
| 165 | |
| 166 | /* preferred governor to switch at register time */ |
| 167 | const char *governor; |
| 168 | }; |
| 169 | |
| 170 | #ifdef CONFIG_CPU_IDLE |
| 171 | extern void disable_cpuidle(void); |
| 172 | extern bool cpuidle_not_available(struct cpuidle_driver *drv, |
| 173 | struct cpuidle_device *dev); |
| 174 | |
| 175 | extern int cpuidle_select(struct cpuidle_driver *drv, |
| 176 | struct cpuidle_device *dev, |
| 177 | bool *stop_tick); |
| 178 | extern int cpuidle_enter(struct cpuidle_driver *drv, |
| 179 | struct cpuidle_device *dev, int index); |
| 180 | extern void cpuidle_reflect(struct cpuidle_device *dev, int index); |
| 181 | extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, |
| 182 | struct cpuidle_device *dev); |
| 183 | |
| 184 | extern int cpuidle_register_driver(struct cpuidle_driver *drv); |
| 185 | extern struct cpuidle_driver *cpuidle_get_driver(void); |
| 186 | extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, |
| 187 | bool disable); |
| 188 | extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); |
| 189 | extern int cpuidle_register_device(struct cpuidle_device *dev); |
| 190 | extern void cpuidle_unregister_device(struct cpuidle_device *dev); |
| 191 | extern int cpuidle_register(struct cpuidle_driver *drv, |
| 192 | const struct cpumask *const coupled_cpus); |
| 193 | extern void cpuidle_unregister(struct cpuidle_driver *drv); |
| 194 | extern void cpuidle_pause_and_lock(void); |
| 195 | extern void cpuidle_resume_and_unlock(void); |
| 196 | extern void cpuidle_pause(void); |
| 197 | extern void cpuidle_resume(void); |
| 198 | extern int cpuidle_enable_device(struct cpuidle_device *dev); |
| 199 | extern void cpuidle_disable_device(struct cpuidle_device *dev); |
| 200 | extern int cpuidle_play_dead(void); |
| 201 | |
| 202 | extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); |
| 203 | static inline struct cpuidle_device *cpuidle_get_device(void) |
| 204 | {return __this_cpu_read(cpuidle_devices); } |
| 205 | #else |
| 206 | static inline void disable_cpuidle(void) { } |
| 207 | static inline bool cpuidle_not_available(struct cpuidle_driver *drv, |
| 208 | struct cpuidle_device *dev) |
| 209 | {return true; } |
| 210 | static inline int cpuidle_select(struct cpuidle_driver *drv, |
| 211 | struct cpuidle_device *dev, bool *stop_tick) |
| 212 | {return -ENODEV; } |
| 213 | static inline int cpuidle_enter(struct cpuidle_driver *drv, |
| 214 | struct cpuidle_device *dev, int index) |
| 215 | {return -ENODEV; } |
| 216 | static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } |
| 217 | static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, |
| 218 | struct cpuidle_device *dev) |
| 219 | {return 0; } |
| 220 | static inline int cpuidle_register_driver(struct cpuidle_driver *drv) |
| 221 | {return -ENODEV; } |
| 222 | static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } |
| 223 | static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, |
| 224 | int idx, bool disable) { } |
| 225 | static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } |
| 226 | static inline int cpuidle_register_device(struct cpuidle_device *dev) |
| 227 | {return -ENODEV; } |
| 228 | static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } |
| 229 | static inline int cpuidle_register(struct cpuidle_driver *drv, |
| 230 | const struct cpumask *const coupled_cpus) |
| 231 | {return -ENODEV; } |
| 232 | static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } |
| 233 | static inline void cpuidle_pause_and_lock(void) { } |
| 234 | static inline void cpuidle_resume_and_unlock(void) { } |
| 235 | static inline void cpuidle_pause(void) { } |
| 236 | static inline void cpuidle_resume(void) { } |
| 237 | static inline int cpuidle_enable_device(struct cpuidle_device *dev) |
| 238 | {return -ENODEV; } |
| 239 | static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } |
| 240 | static inline int cpuidle_play_dead(void) {return -ENODEV; } |
| 241 | static inline struct cpuidle_driver *cpuidle_get_cpu_driver( |
| 242 | struct cpuidle_device *dev) {return NULL; } |
| 243 | static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } |
| 244 | #endif |
| 245 | |
| 246 | #ifdef CONFIG_CPU_IDLE |
| 247 | extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, |
| 248 | struct cpuidle_device *dev, |
| 249 | u64 latency_limit_ns); |
| 250 | extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, |
| 251 | struct cpuidle_device *dev); |
| 252 | extern void cpuidle_use_deepest_state(u64 latency_limit_ns); |
| 253 | #else |
| 254 | static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, |
| 255 | struct cpuidle_device *dev, |
| 256 | u64 latency_limit_ns) |
| 257 | {return -ENODEV; } |
| 258 | static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, |
| 259 | struct cpuidle_device *dev) |
| 260 | {return -ENODEV; } |
| 261 | static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) |
| 262 | { |
| 263 | } |
| 264 | #endif |
| 265 | |
| 266 | /* kernel/sched/idle.c */ |
| 267 | extern void sched_idle_set_state(struct cpuidle_state *idle_state); |
| 268 | extern void default_idle_call(void); |
| 269 | |
| 270 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED |
| 271 | void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); |
| 272 | #else |
| 273 | static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) |
| 274 | { |
| 275 | } |
| 276 | #endif |
| 277 | |
| 278 | #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) |
| 279 | void cpuidle_poll_state_init(struct cpuidle_driver *drv); |
| 280 | #else |
| 281 | static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} |
| 282 | #endif |
| 283 | |
| 284 | /****************************** |
| 285 | * CPUIDLE GOVERNOR INTERFACE * |
| 286 | ******************************/ |
| 287 | |
| 288 | struct cpuidle_governor { |
| 289 | char name[CPUIDLE_NAME_LEN]; |
| 290 | struct list_head governor_list; |
| 291 | unsigned int rating; |
| 292 | |
| 293 | int (*enable) (struct cpuidle_driver *drv, |
| 294 | struct cpuidle_device *dev); |
| 295 | void (*disable) (struct cpuidle_driver *drv, |
| 296 | struct cpuidle_device *dev); |
| 297 | |
| 298 | int (*select) (struct cpuidle_driver *drv, |
| 299 | struct cpuidle_device *dev, |
| 300 | bool *stop_tick); |
| 301 | void (*reflect) (struct cpuidle_device *dev, int index); |
| 302 | }; |
| 303 | |
| 304 | extern int cpuidle_register_governor(struct cpuidle_governor *gov); |
| 305 | extern s64 cpuidle_governor_latency_req(unsigned int cpu); |
| 306 | |
| 307 | #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ |
| 308 | idx, \ |
| 309 | state, \ |
| 310 | is_retention, is_rcu) \ |
| 311 | ({ \ |
| 312 | int __ret = 0; \ |
| 313 | \ |
| 314 | if (!idx) { \ |
| 315 | cpu_do_idle(); \ |
| 316 | return idx; \ |
| 317 | } \ |
| 318 | \ |
| 319 | if (!is_retention) \ |
| 320 | __ret = cpu_pm_enter(); \ |
| 321 | if (!__ret) { \ |
| 322 | if (!is_rcu) \ |
| 323 | ct_cpuidle_enter(); \ |
| 324 | __ret = low_level_idle_enter(state); \ |
| 325 | if (!is_rcu) \ |
| 326 | ct_cpuidle_exit(); \ |
| 327 | if (!is_retention) \ |
| 328 | cpu_pm_exit(); \ |
| 329 | } \ |
| 330 | \ |
| 331 | __ret ? -1 : idx; \ |
| 332 | }) |
| 333 | |
| 334 | #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ |
| 335 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0, 0) |
| 336 | |
| 337 | #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ |
| 338 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1, 0) |
| 339 | |
| 340 | #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ |
| 341 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 0) |
| 342 | |
| 343 | #define CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(low_level_idle_enter, idx, state) \ |
| 344 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 1) |
| 345 | |
| 346 | #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \ |
| 347 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 0) |
| 348 | |
| 349 | #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(low_level_idle_enter, idx, state) \ |
| 350 | __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 1) |
| 351 | |
| 352 | #endif /* _LINUX_CPUIDLE_H */ |