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 cpumask_t coupled_cpus;
88 struct cpuidle_coupled *coupled;
89 #endif
90 };
91
92 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
93 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
94
95 /**
96 * cpuidle_get_last_residency - retrieves the last state's residency time
97 * @dev: the target CPU
98 */
cpuidle_get_last_residency(struct cpuidle_device * dev)99 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
100 {
101 return dev->last_residency;
102 }
103
104
105 /****************************
106 * CPUIDLE DRIVER INTERFACE *
107 ****************************/
108
109 struct cpuidle_driver {
110 const char *name;
111 struct module *owner;
112 int refcnt;
113
114 /* used by the cpuidle framework to setup the broadcast timer */
115 unsigned int bctimer:1;
116 /* states array must be ordered in decreasing power consumption */
117 struct cpuidle_state states[CPUIDLE_STATE_MAX];
118 int state_count;
119 int safe_state_index;
120
121 /* the driver handles the cpus in cpumask */
122 struct cpumask *cpumask;
123 };
124
125 #ifdef CONFIG_CPU_IDLE
126 extern void disable_cpuidle(void);
127 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
128 struct cpuidle_device *dev);
129
130 extern int cpuidle_select(struct cpuidle_driver *drv,
131 struct cpuidle_device *dev);
132 extern int cpuidle_enter(struct cpuidle_driver *drv,
133 struct cpuidle_device *dev, int index);
134 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
135
136 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
137 extern struct cpuidle_driver *cpuidle_get_driver(void);
138 extern struct cpuidle_driver *cpuidle_driver_ref(void);
139 extern void cpuidle_driver_unref(void);
140 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
141 extern int cpuidle_register_device(struct cpuidle_device *dev);
142 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
143 extern int cpuidle_register(struct cpuidle_driver *drv,
144 const struct cpumask *const coupled_cpus);
145 extern void cpuidle_unregister(struct cpuidle_driver *drv);
146 extern void cpuidle_pause_and_lock(void);
147 extern void cpuidle_resume_and_unlock(void);
148 extern void cpuidle_pause(void);
149 extern void cpuidle_resume(void);
150 extern int cpuidle_enable_device(struct cpuidle_device *dev);
151 extern void cpuidle_disable_device(struct cpuidle_device *dev);
152 extern int cpuidle_play_dead(void);
153
154 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
cpuidle_get_device(void)155 static inline struct cpuidle_device *cpuidle_get_device(void)
156 {return __this_cpu_read(cpuidle_devices); }
157 #else
disable_cpuidle(void)158 static inline void disable_cpuidle(void) { }
cpuidle_not_available(struct cpuidle_driver * drv,struct cpuidle_device * dev)159 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
160 struct cpuidle_device *dev)
161 {return true; }
cpuidle_select(struct cpuidle_driver * drv,struct cpuidle_device * dev)162 static inline int cpuidle_select(struct cpuidle_driver *drv,
163 struct cpuidle_device *dev)
164 {return -ENODEV; }
cpuidle_enter(struct cpuidle_driver * drv,struct cpuidle_device * dev,int index)165 static inline int cpuidle_enter(struct cpuidle_driver *drv,
166 struct cpuidle_device *dev, int index)
167 {return -ENODEV; }
cpuidle_reflect(struct cpuidle_device * dev,int index)168 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
cpuidle_register_driver(struct cpuidle_driver * drv)169 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
170 {return -ENODEV; }
cpuidle_get_driver(void)171 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
cpuidle_driver_ref(void)172 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
cpuidle_driver_unref(void)173 static inline void cpuidle_driver_unref(void) {}
cpuidle_unregister_driver(struct cpuidle_driver * drv)174 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
cpuidle_register_device(struct cpuidle_device * dev)175 static inline int cpuidle_register_device(struct cpuidle_device *dev)
176 {return -ENODEV; }
cpuidle_unregister_device(struct cpuidle_device * dev)177 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
cpuidle_register(struct cpuidle_driver * drv,const struct cpumask * const coupled_cpus)178 static inline int cpuidle_register(struct cpuidle_driver *drv,
179 const struct cpumask *const coupled_cpus)
180 {return -ENODEV; }
cpuidle_unregister(struct cpuidle_driver * drv)181 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
cpuidle_pause_and_lock(void)182 static inline void cpuidle_pause_and_lock(void) { }
cpuidle_resume_and_unlock(void)183 static inline void cpuidle_resume_and_unlock(void) { }
cpuidle_pause(void)184 static inline void cpuidle_pause(void) { }
cpuidle_resume(void)185 static inline void cpuidle_resume(void) { }
cpuidle_enable_device(struct cpuidle_device * dev)186 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
187 {return -ENODEV; }
cpuidle_disable_device(struct cpuidle_device * dev)188 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
cpuidle_play_dead(void)189 static inline int cpuidle_play_dead(void) {return -ENODEV; }
cpuidle_get_cpu_driver(struct cpuidle_device * dev)190 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
191 struct cpuidle_device *dev) {return NULL; }
cpuidle_get_device(void)192 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
193 #endif
194
195 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
196 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
197 struct cpuidle_device *dev);
198 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
199 struct cpuidle_device *dev);
200 #else
cpuidle_find_deepest_state(struct cpuidle_driver * drv,struct cpuidle_device * dev)201 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
202 struct cpuidle_device *dev)
203 {return -ENODEV; }
cpuidle_enter_freeze(struct cpuidle_driver * drv,struct cpuidle_device * dev)204 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev)
206 {return -ENODEV; }
207 #endif
208
209 /* kernel/sched/idle.c */
210 extern void sched_idle_set_state(struct cpuidle_state *idle_state, int index);
211 extern void default_idle_call(void);
212
213 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
214 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
215 #else
cpuidle_coupled_parallel_barrier(struct cpuidle_device * dev,atomic_t * a)216 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
217 {
218 }
219 #endif
220
221 /******************************
222 * CPUIDLE GOVERNOR INTERFACE *
223 ******************************/
224
225 struct cpuidle_governor {
226 char name[CPUIDLE_NAME_LEN];
227 struct list_head governor_list;
228 unsigned int rating;
229
230 int (*enable) (struct cpuidle_driver *drv,
231 struct cpuidle_device *dev);
232 void (*disable) (struct cpuidle_driver *drv,
233 struct cpuidle_device *dev);
234
235 int (*select) (struct cpuidle_driver *drv,
236 struct cpuidle_device *dev);
237 void (*reflect) (struct cpuidle_device *dev, int index);
238
239 struct module *owner;
240 };
241
242 #ifdef CONFIG_CPU_IDLE
243 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
244 #else
cpuidle_register_governor(struct cpuidle_governor * gov)245 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
246 {return 0;}
247 #endif
248
249 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
250 #define CPUIDLE_DRIVER_STATE_START 1
251 #else
252 #define CPUIDLE_DRIVER_STATE_START 0
253 #endif
254
255 #endif /* _LINUX_CPUIDLE_H */
256