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/kobject.h>
17 #include <linux/completion.h>
18 #include <linux/hrtimer.h>
20 #define CPUIDLE_STATE_MAX 10
21 #define CPUIDLE_NAME_LEN 16
22 #define CPUIDLE_DESC_LEN 32
26 struct cpuidle_device;
27 struct cpuidle_driver;
30 /****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
34 struct cpuidle_state_usage {
35 unsigned long long disable;
36 unsigned long long usage;
37 unsigned long long time; /* in US */
40 struct cpuidle_state {
41 char name[CPUIDLE_NAME_LEN];
42 char desc[CPUIDLE_DESC_LEN];
45 unsigned int exit_latency; /* in US */
46 int power_usage; /* in mW */
47 unsigned int target_residency; /* in US */
48 bool disabled; /* disabled on all CPUs */
50 int (*enter) (struct cpuidle_device *dev,
51 struct cpuidle_driver *drv,
54 int (*enter_dead) (struct cpuidle_device *dev, int index);
57 /* Idle State Flags */
58 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
59 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
60 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
62 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
64 struct cpuidle_device {
65 unsigned int registered:1;
66 unsigned int enabled:1;
71 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
72 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
73 struct cpuidle_driver_kobj *kobj_driver;
74 struct list_head device_list;
76 struct completion kobj_unregister;
78 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
80 cpumask_t coupled_cpus;
81 struct cpuidle_coupled *coupled;
85 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
88 * cpuidle_get_last_residency - retrieves the last state's residency time
89 * @dev: the target CPU
91 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
93 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
95 return dev->last_residency;
99 /****************************
100 * CPUIDLE DRIVER INTERFACE *
101 ****************************/
103 struct cpuidle_driver {
105 struct module *owner;
108 /* used by the cpuidle framework to setup the broadcast timer */
109 unsigned int bctimer:1;
110 /* states array must be ordered in decreasing power consumption */
111 struct cpuidle_state states[CPUIDLE_STATE_MAX];
113 int safe_state_index;
114 struct cpumask *cpumask;
117 #ifdef CONFIG_CPU_IDLE
118 extern void disable_cpuidle(void);
119 extern int cpuidle_idle_call(void);
120 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
121 extern struct cpuidle_driver *cpuidle_get_driver(void);
122 extern struct cpuidle_driver *cpuidle_driver_ref(void);
123 extern void cpuidle_driver_unref(void);
124 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
125 extern int cpuidle_register_device(struct cpuidle_device *dev);
126 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
127 extern int cpuidle_register(struct cpuidle_driver *drv,
128 const struct cpumask *const coupled_cpus);
129 extern void cpuidle_unregister(struct cpuidle_driver *drv);
130 extern void cpuidle_pause_and_lock(void);
131 extern void cpuidle_resume_and_unlock(void);
132 extern void cpuidle_pause(void);
133 extern void cpuidle_resume(void);
134 extern int cpuidle_enable_device(struct cpuidle_device *dev);
135 extern void cpuidle_disable_device(struct cpuidle_device *dev);
136 extern int cpuidle_play_dead(void);
138 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
139 extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
140 extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
143 static inline void disable_cpuidle(void) { }
144 static inline int cpuidle_idle_call(void) { return -ENODEV; }
145 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
147 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
148 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
149 static inline void cpuidle_driver_unref(void) {}
150 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
151 static inline int cpuidle_register_device(struct cpuidle_device *dev)
153 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
154 static inline int cpuidle_register(struct cpuidle_driver *drv,
155 const struct cpumask *const coupled_cpus)
157 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
158 static inline void cpuidle_pause_and_lock(void) { }
159 static inline void cpuidle_resume_and_unlock(void) { }
160 static inline void cpuidle_pause(void) { }
161 static inline void cpuidle_resume(void) { }
162 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
164 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
165 static inline int cpuidle_play_dead(void) {return -ENODEV; }
168 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
169 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
171 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
176 /******************************
177 * CPUIDLE GOVERNOR INTERFACE *
178 ******************************/
180 struct cpuidle_governor {
181 char name[CPUIDLE_NAME_LEN];
182 struct list_head governor_list;
185 int (*enable) (struct cpuidle_driver *drv,
186 struct cpuidle_device *dev);
187 void (*disable) (struct cpuidle_driver *drv,
188 struct cpuidle_device *dev);
190 int (*select) (struct cpuidle_driver *drv,
191 struct cpuidle_device *dev);
192 void (*reflect) (struct cpuidle_device *dev, int index);
194 struct module *owner;
197 #ifdef CONFIG_CPU_IDLE
199 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
200 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
204 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
206 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
210 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
211 #define CPUIDLE_DRIVER_STATE_START 1
213 #define CPUIDLE_DRIVER_STATE_START 0
216 #endif /* _LINUX_CPUIDLE_H */