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
;
116 #ifdef CONFIG_CPU_IDLE
117 extern void disable_cpuidle(void);
118 extern int cpuidle_idle_call(void);
119 extern int cpuidle_register_driver(struct cpuidle_driver
*drv
);
120 extern struct cpuidle_driver
*cpuidle_get_driver(void);
121 extern struct cpuidle_driver
*cpuidle_driver_ref(void);
122 extern void cpuidle_driver_unref(void);
123 extern void cpuidle_unregister_driver(struct cpuidle_driver
*drv
);
124 extern int cpuidle_register_device(struct cpuidle_device
*dev
);
125 extern void cpuidle_unregister_device(struct cpuidle_device
*dev
);
126 extern int cpuidle_register(struct cpuidle_driver
*drv
,
127 const struct cpumask
*const coupled_cpus
);
128 extern void cpuidle_unregister(struct cpuidle_driver
*drv
);
129 extern void cpuidle_pause_and_lock(void);
130 extern void cpuidle_resume_and_unlock(void);
131 extern void cpuidle_pause(void);
132 extern void cpuidle_resume(void);
133 extern int cpuidle_enable_device(struct cpuidle_device
*dev
);
134 extern void cpuidle_disable_device(struct cpuidle_device
*dev
);
135 extern int cpuidle_play_dead(void);
137 extern struct cpuidle_driver
*cpuidle_get_cpu_driver(struct cpuidle_device
*dev
);
138 extern int cpuidle_register_cpu_driver(struct cpuidle_driver
*drv
, int cpu
);
139 extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver
*drv
, int cpu
);
142 static inline void disable_cpuidle(void) { }
143 static inline int cpuidle_idle_call(void) { return -ENODEV
; }
144 static inline int cpuidle_register_driver(struct cpuidle_driver
*drv
)
146 static inline struct cpuidle_driver
*cpuidle_get_driver(void) {return NULL
; }
147 static inline struct cpuidle_driver
*cpuidle_driver_ref(void) {return NULL
; }
148 static inline void cpuidle_driver_unref(void) {}
149 static inline void cpuidle_unregister_driver(struct cpuidle_driver
*drv
) { }
150 static inline int cpuidle_register_device(struct cpuidle_device
*dev
)
152 static inline void cpuidle_unregister_device(struct cpuidle_device
*dev
) { }
153 static inline int cpuidle_register(struct cpuidle_driver
*drv
,
154 const struct cpumask
*const coupled_cpus
)
156 static inline void cpuidle_unregister(struct cpuidle_driver
*drv
) { }
157 static inline void cpuidle_pause_and_lock(void) { }
158 static inline void cpuidle_resume_and_unlock(void) { }
159 static inline void cpuidle_pause(void) { }
160 static inline void cpuidle_resume(void) { }
161 static inline int cpuidle_enable_device(struct cpuidle_device
*dev
)
163 static inline void cpuidle_disable_device(struct cpuidle_device
*dev
) { }
164 static inline int cpuidle_play_dead(void) {return -ENODEV
; }
167 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
168 void cpuidle_coupled_parallel_barrier(struct cpuidle_device
*dev
, atomic_t
*a
);
170 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device
*dev
, atomic_t
*a
)
175 /******************************
176 * CPUIDLE GOVERNOR INTERFACE *
177 ******************************/
179 struct cpuidle_governor
{
180 char name
[CPUIDLE_NAME_LEN
];
181 struct list_head governor_list
;
184 int (*enable
) (struct cpuidle_driver
*drv
,
185 struct cpuidle_device
*dev
);
186 void (*disable
) (struct cpuidle_driver
*drv
,
187 struct cpuidle_device
*dev
);
189 int (*select
) (struct cpuidle_driver
*drv
,
190 struct cpuidle_device
*dev
);
191 void (*reflect
) (struct cpuidle_device
*dev
, int index
);
193 struct module
*owner
;
196 #ifdef CONFIG_CPU_IDLE
198 extern int cpuidle_register_governor(struct cpuidle_governor
*gov
);
199 extern void cpuidle_unregister_governor(struct cpuidle_governor
*gov
);
203 static inline int cpuidle_register_governor(struct cpuidle_governor
*gov
)
205 static inline void cpuidle_unregister_governor(struct cpuidle_governor
*gov
) { }
209 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
210 #define CPUIDLE_DRIVER_STATE_START 1
212 #define CPUIDLE_DRIVER_STATE_START 0
215 #endif /* _LINUX_CPUIDLE_H */