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 23struct module; 24 25struct cpuidle_device; 26struct 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 36struct 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 49struct 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 89struct cpuidle_device_kobj; 90struct cpuidle_state_kobj; 91struct cpuidle_driver_kobj; 92 93struct 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 116DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 117DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 118 119static __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 138static __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 152struct 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 171extern void disable_cpuidle(void); 172extern bool cpuidle_not_available(struct cpuidle_driver *drv, 173 struct cpuidle_device *dev); 174 175extern int cpuidle_select(struct cpuidle_driver *drv, 176 struct cpuidle_device *dev, 177 bool *stop_tick); 178extern int cpuidle_enter(struct cpuidle_driver *drv, 179 struct cpuidle_device *dev, int index); 180extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 181extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, 182 struct cpuidle_device *dev); 183 184extern int cpuidle_register_driver(struct cpuidle_driver *drv); 185extern struct cpuidle_driver *cpuidle_get_driver(void); 186extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, 187 bool disable); 188extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 189extern int cpuidle_register_device(struct cpuidle_device *dev); 190extern void cpuidle_unregister_device(struct cpuidle_device *dev); 191extern int cpuidle_register(struct cpuidle_driver *drv, 192 const struct cpumask *const coupled_cpus); 193extern void cpuidle_unregister(struct cpuidle_driver *drv); 194extern void cpuidle_pause_and_lock(void); 195extern void cpuidle_resume_and_unlock(void); 196extern void cpuidle_pause(void); 197extern void cpuidle_resume(void); 198extern int cpuidle_enable_device(struct cpuidle_device *dev); 199extern void cpuidle_disable_device(struct cpuidle_device *dev); 200extern int cpuidle_play_dead(void); 201 202extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 203static inline struct cpuidle_device *cpuidle_get_device(void) 204{return __this_cpu_read(cpuidle_devices); } 205#else 206static inline void disable_cpuidle(void) { } 207static inline bool cpuidle_not_available(struct cpuidle_driver *drv, 208 struct cpuidle_device *dev) 209{return true; } 210static inline int cpuidle_select(struct cpuidle_driver *drv, 211 struct cpuidle_device *dev, bool *stop_tick) 212{return -ENODEV; } 213static inline int cpuidle_enter(struct cpuidle_driver *drv, 214 struct cpuidle_device *dev, int index) 215{return -ENODEV; } 216static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 217static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, 218 struct cpuidle_device *dev) 219{return 0; } 220static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 221{return -ENODEV; } 222static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 223static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, 224 int idx, bool disable) { } 225static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 226static inline int cpuidle_register_device(struct cpuidle_device *dev) 227{return -ENODEV; } 228static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 229static inline int cpuidle_register(struct cpuidle_driver *drv, 230 const struct cpumask *const coupled_cpus) 231{return -ENODEV; } 232static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 233static inline void cpuidle_pause_and_lock(void) { } 234static inline void cpuidle_resume_and_unlock(void) { } 235static inline void cpuidle_pause(void) { } 236static inline void cpuidle_resume(void) { } 237static inline int cpuidle_enable_device(struct cpuidle_device *dev) 238{return -ENODEV; } 239static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 240static inline int cpuidle_play_dead(void) {return -ENODEV; } 241static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 242 struct cpuidle_device *dev) {return NULL; } 243static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } 244#endif 245 246#ifdef CONFIG_CPU_IDLE 247extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 248 struct cpuidle_device *dev, 249 u64 latency_limit_ns); 250extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 251 struct cpuidle_device *dev); 252extern void cpuidle_use_deepest_state(u64 latency_limit_ns); 253#else 254static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 255 struct cpuidle_device *dev, 256 u64 latency_limit_ns) 257{return -ENODEV; } 258static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, 259 struct cpuidle_device *dev) 260{return -ENODEV; } 261static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) 262{ 263} 264#endif 265 266/* kernel/sched/idle.c */ 267extern void sched_idle_set_state(struct cpuidle_state *idle_state); 268extern void default_idle_call(void); 269 270#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 271void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 272#else 273static 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) 279void cpuidle_poll_state_init(struct cpuidle_driver *drv); 280#else 281static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} 282#endif 283 284/****************************** 285 * CPUIDLE GOVERNOR INTERFACE * 286 ******************************/ 287 288struct 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 304extern int cpuidle_register_governor(struct cpuidle_governor *gov); 305extern 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 */ 353