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 /* Idle State Flags */ 56 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 57 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ 58 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ 59 60 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 61 62 struct cpuidle_device_kobj; 63 struct cpuidle_state_kobj; 64 struct cpuidle_driver_kobj; 65 66 struct cpuidle_device { 67 unsigned int registered:1; 68 unsigned int enabled:1; 69 unsigned int cpu; 70 71 int last_residency; 72 int state_count; 73 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 74 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 75 struct cpuidle_driver_kobj *kobj_driver; 76 struct cpuidle_device_kobj *kobj_dev; 77 struct list_head device_list; 78 79 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 80 int safe_state_index; 81 cpumask_t coupled_cpus; 82 struct cpuidle_coupled *coupled; 83 #endif 84 }; 85 86 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 87 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); 88 89 /** 90 * cpuidle_get_last_residency - retrieves the last state's residency time 91 * @dev: the target CPU 92 * 93 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 94 */ 95 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 96 { 97 return dev->last_residency; 98 } 99 100 101 /**************************** 102 * CPUIDLE DRIVER INTERFACE * 103 ****************************/ 104 105 struct cpuidle_driver { 106 const char *name; 107 struct module *owner; 108 int refcnt; 109 110 /* used by the cpuidle framework to setup the broadcast timer */ 111 unsigned int bctimer:1; 112 /* states array must be ordered in decreasing power consumption */ 113 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 114 int state_count; 115 int safe_state_index; 116 117 /* the driver handles the cpus in cpumask */ 118 struct cpumask *cpumask; 119 }; 120 121 #ifdef CONFIG_CPU_IDLE 122 extern void disable_cpuidle(void); 123 124 extern int cpuidle_enabled(struct cpuidle_driver *drv, 125 struct cpuidle_device *dev); 126 extern int cpuidle_select(struct cpuidle_driver *drv, 127 struct cpuidle_device *dev); 128 extern int cpuidle_enter(struct cpuidle_driver *drv, 129 struct cpuidle_device *dev, int index); 130 extern void cpuidle_reflect(struct cpuidle_device *dev, int index); 131 132 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 133 extern struct cpuidle_driver *cpuidle_get_driver(void); 134 extern struct cpuidle_driver *cpuidle_driver_ref(void); 135 extern void cpuidle_driver_unref(void); 136 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 137 extern int cpuidle_register_device(struct cpuidle_device *dev); 138 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 139 extern int cpuidle_register(struct cpuidle_driver *drv, 140 const struct cpumask *const coupled_cpus); 141 extern void cpuidle_unregister(struct cpuidle_driver *drv); 142 extern void cpuidle_pause_and_lock(void); 143 extern void cpuidle_resume_and_unlock(void); 144 extern void cpuidle_pause(void); 145 extern void cpuidle_resume(void); 146 extern int cpuidle_enable_device(struct cpuidle_device *dev); 147 extern void cpuidle_disable_device(struct cpuidle_device *dev); 148 extern int cpuidle_play_dead(void); 149 150 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); 151 #else 152 static inline void disable_cpuidle(void) { } 153 static inline int cpuidle_enabled(struct cpuidle_driver *drv, 154 struct cpuidle_device *dev) 155 {return -ENODEV; } 156 static inline int cpuidle_select(struct cpuidle_driver *drv, 157 struct cpuidle_device *dev) 158 {return -ENODEV; } 159 static inline int cpuidle_enter(struct cpuidle_driver *drv, 160 struct cpuidle_device *dev, int index) 161 {return -ENODEV; } 162 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } 163 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 164 {return -ENODEV; } 165 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 166 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } 167 static inline void cpuidle_driver_unref(void) {} 168 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 169 static inline int cpuidle_register_device(struct cpuidle_device *dev) 170 {return -ENODEV; } 171 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 172 static inline int cpuidle_register(struct cpuidle_driver *drv, 173 const struct cpumask *const coupled_cpus) 174 {return -ENODEV; } 175 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } 176 static inline void cpuidle_pause_and_lock(void) { } 177 static inline void cpuidle_resume_and_unlock(void) { } 178 static inline void cpuidle_pause(void) { } 179 static inline void cpuidle_resume(void) { } 180 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 181 {return -ENODEV; } 182 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 183 static inline int cpuidle_play_dead(void) {return -ENODEV; } 184 static inline struct cpuidle_driver *cpuidle_get_cpu_driver( 185 struct cpuidle_device *dev) {return NULL; } 186 #endif 187 188 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED 189 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); 190 #else 191 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) 192 { 193 } 194 #endif 195 196 /****************************** 197 * CPUIDLE GOVERNOR INTERFACE * 198 ******************************/ 199 200 struct cpuidle_governor { 201 char name[CPUIDLE_NAME_LEN]; 202 struct list_head governor_list; 203 unsigned int rating; 204 205 int (*enable) (struct cpuidle_driver *drv, 206 struct cpuidle_device *dev); 207 void (*disable) (struct cpuidle_driver *drv, 208 struct cpuidle_device *dev); 209 210 int (*select) (struct cpuidle_driver *drv, 211 struct cpuidle_device *dev); 212 void (*reflect) (struct cpuidle_device *dev, int index); 213 214 struct module *owner; 215 }; 216 217 #ifdef CONFIG_CPU_IDLE 218 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 219 #else 220 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 221 {return 0;} 222 #endif 223 224 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 225 #define CPUIDLE_DRIVER_STATE_START 1 226 #else 227 #define CPUIDLE_DRIVER_STATE_START 0 228 #endif 229 230 #endif /* _LINUX_CPUIDLE_H */ 231