2 * cpuidle.h - a generic framework for CPU idle power management
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
8 * This code is licenced under the GPL.
11 #ifndef _LINUX_CPUIDLE_H
12 #define _LINUX_CPUIDLE_H
14 #include <linux/percpu.h>
15 #include <linux/list.h>
16 #include <linux/hrtimer.h>
18 #define CPUIDLE_STATE_MAX 10
19 #define CPUIDLE_NAME_LEN 16
20 #define CPUIDLE_DESC_LEN 32
24 struct cpuidle_device;
25 struct cpuidle_driver;
28 /****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
32 struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
38 struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
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 */
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
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.
59 void (*enter_freeze) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
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 */
68 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
70 struct cpuidle_device_kobj;
71 struct cpuidle_state_kobj;
72 struct cpuidle_driver_kobj;
74 struct cpuidle_device {
75 unsigned int registered:1;
76 unsigned int enabled:1;
81 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
82 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
83 struct cpuidle_driver_kobj *kobj_driver;
84 struct cpuidle_device_kobj *kobj_dev;
85 struct list_head device_list;
87 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
89 cpumask_t coupled_cpus;
90 struct cpuidle_coupled *coupled;
94 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
95 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
98 * cpuidle_get_last_residency - retrieves the last state's residency time
99 * @dev: the target CPU
101 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
103 return dev->last_residency;
107 /****************************
108 * CPUIDLE DRIVER INTERFACE *
109 ****************************/
111 struct cpuidle_driver {
113 struct module *owner;
116 /* used by the cpuidle framework to setup the broadcast timer */
117 unsigned int bctimer:1;
118 /* states array must be ordered in decreasing power consumption */
119 struct cpuidle_state states[CPUIDLE_STATE_MAX];
121 int safe_state_index;
123 /* the driver handles the cpus in cpumask */
124 struct cpumask *cpumask;
127 #ifdef CONFIG_CPU_IDLE
128 extern void disable_cpuidle(void);
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);
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 extern void cpuidle_enter_freeze(void);
155 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
157 static inline void disable_cpuidle(void) { }
158 static inline int cpuidle_select(struct cpuidle_driver *drv,
159 struct cpuidle_device *dev)
161 static inline int cpuidle_enter(struct cpuidle_driver *drv,
162 struct cpuidle_device *dev, int index)
164 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
165 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
167 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
168 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
169 static inline void cpuidle_driver_unref(void) {}
170 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
171 static inline int cpuidle_register_device(struct cpuidle_device *dev)
173 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
174 static inline int cpuidle_register(struct cpuidle_driver *drv,
175 const struct cpumask *const coupled_cpus)
177 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
178 static inline void cpuidle_pause_and_lock(void) { }
179 static inline void cpuidle_resume_and_unlock(void) { }
180 static inline void cpuidle_pause(void) { }
181 static inline void cpuidle_resume(void) { }
182 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
184 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
185 static inline int cpuidle_play_dead(void) {return -ENODEV; }
186 static inline void cpuidle_enter_freeze(void) { }
187 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
188 struct cpuidle_device *dev) {return NULL; }
191 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
192 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
194 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
199 /******************************
200 * CPUIDLE GOVERNOR INTERFACE *
201 ******************************/
203 struct cpuidle_governor {
204 char name[CPUIDLE_NAME_LEN];
205 struct list_head governor_list;
208 int (*enable) (struct cpuidle_driver *drv,
209 struct cpuidle_device *dev);
210 void (*disable) (struct cpuidle_driver *drv,
211 struct cpuidle_device *dev);
213 int (*select) (struct cpuidle_driver *drv,
214 struct cpuidle_device *dev);
215 void (*reflect) (struct cpuidle_device *dev, int index);
217 struct module *owner;
220 #ifdef CONFIG_CPU_IDLE
221 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
223 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
227 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
228 #define CPUIDLE_DRIVER_STATE_START 1
230 #define CPUIDLE_DRIVER_STATE_START 0
233 #endif /* _LINUX_CPUIDLE_H */