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 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_COUPLED (0x02) /* state applies to multiple cpus */ 66 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 67 68 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 69 70 struct cpuidle_device_kobj; 71 struct cpuidle_state_kobj; 72 struct cpuidle_driver_kobj; 73 74 struct cpuidle_device { 75 unsigned int registered:1; 76 unsigned int enabled:1; 77 unsigned int cpu; 78 79 int last_residency; 80 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 81 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 82 struct cpuidle_driver_kobj *kobj_driver; 83 struct cpuidle_device_kobj *kobj_dev; 84 struct list_head device_list; 85 86 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 87 int safe_state_index; 88 cpumask_t coupled_cpus; 89 struct cpuidle_coupled *coupled; 90 #endif 91 }; 92 93 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 94 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 95 96 /** 97 * cpuidle_get_last_residency - retrieves the last state's residency time 98 * @dev: the target CPU 99 */ 100 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 101 { 102 return dev->last_residency; 103 } 104 105 106 /**************************** 107 * CPUIDLE DRIVER INTERFACE * 108 ****************************/ 109 110 struct cpuidle_driver { 111 const char *name; 112 struct module *owner; 113 int refcnt; 114 115 /* used by the cpuidle framework to setup the broadcast timer */ 116 unsigned int bctimer:1; 117 /* states array must be ordered in decreasing power consumption */ 118 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 119 int state_count; 120 int safe_state_index; 121 122 /* the driver handles the cpus in cpumask */ 123 struct cpumask *cpumask; 124 }; 125 126 #ifdef CONFIG_CPU_IDLE 127 extern void disable_cpuidle(void); 128 extern bool cpuidle_not_available(struct cpuidle_driver *drv, 129 struct cpuidle_device *dev); 130 131 extern int cpuidle_select(struct cpuidle_driver *drv, 132 struct cpuidle_device *dev); 133 extern int cpuidle_enter(struct cpuidle_driver *drv, 134 struct cpuidle_device *dev, int index); 135 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 136 137 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 138 extern struct cpuidle_driver *cpuidle_get_driver(void); 139 extern struct cpuidle_driver *cpuidle_driver_ref(void); 140 extern void cpuidle_driver_unref(void); 141 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 142 extern int cpuidle_register_device(struct cpuidle_device *dev); 143 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 144 extern int cpuidle_register(struct cpuidle_driver *drv, 145 const struct cpumask *const coupled_cpus); 146 extern void cpuidle_unregister(struct cpuidle_driver *drv); 147 extern void cpuidle_pause_and_lock(void); 148 extern void cpuidle_resume_and_unlock(void); 149 extern void cpuidle_pause(void); 150 extern void cpuidle_resume(void); 151 extern int cpuidle_enable_device(struct cpuidle_device *dev); 152 extern void cpuidle_disable_device(struct cpuidle_device *dev); 153 extern int cpuidle_play_dead(void); 154 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 155 struct cpuidle_device *dev); 156 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, 157 struct cpuidle_device *dev); 158 159 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 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 int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 194 struct cpuidle_device *dev) 195 {return -ENODEV; } 196 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv, 197 struct cpuidle_device *dev) 198 {return -ENODEV; } 199 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 200 struct cpuidle_device *dev) {return NULL; } 201 #endif 202 203 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 204 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 205 #else 206 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 207 { 208 } 209 #endif 210 211 /****************************** 212 * CPUIDLE GOVERNOR INTERFACE * 213 ******************************/ 214 215 struct cpuidle_governor { 216 char name[CPUIDLE_NAME_LEN]; 217 struct list_head governor_list; 218 unsigned int rating; 219 220 int (*enable) (struct cpuidle_driver *drv, 221 struct cpuidle_device *dev); 222 void (*disable) (struct cpuidle_driver *drv, 223 struct cpuidle_device *dev); 224 225 int (*select) (struct cpuidle_driver *drv, 226 struct cpuidle_device *dev); 227 void (*reflect) (struct cpuidle_device *dev, int index); 228 229 struct module *owner; 230 }; 231 232 #ifdef CONFIG_CPU_IDLE 233 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 234 #else 235 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 236 {return 0;} 237 #endif 238 239 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 240 #define CPUIDLE_DRIVER_STATE_START 1 241 #else 242 #define CPUIDLE_DRIVER_STATE_START 0 243 #endif 244 245 #endif /* _LINUX_CPUIDLE_H */ 246