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 /* 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 */
60 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62 struct cpuidle_device_kobj
;
63 struct cpuidle_state_kobj
;
64 struct cpuidle_driver_kobj
;
66 struct cpuidle_device
{
67 unsigned int registered
:1;
68 unsigned int enabled
:1;
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
;
79 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
81 cpumask_t coupled_cpus
;
82 struct cpuidle_coupled
*coupled
;
86 DECLARE_PER_CPU(struct cpuidle_device
*, cpuidle_devices
);
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
92 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
94 static inline int cpuidle_get_last_residency(struct cpuidle_device
*dev
)
96 return dev
->last_residency
;
100 /****************************
101 * CPUIDLE DRIVER INTERFACE *
102 ****************************/
104 struct cpuidle_driver
{
106 struct module
*owner
;
109 /* used by the cpuidle framework to setup the broadcast timer */
110 unsigned int bctimer
:1;
111 /* states array must be ordered in decreasing power consumption */
112 struct cpuidle_state states
[CPUIDLE_STATE_MAX
];
114 int safe_state_index
;
116 /* the driver handles the cpus in cpumask */
117 struct cpumask
*cpumask
;
120 #ifdef CONFIG_CPU_IDLE
121 extern void disable_cpuidle(void);
122 extern int cpuidle_idle_call(void);
123 extern int cpuidle_register_driver(struct cpuidle_driver
*drv
);
124 extern struct cpuidle_driver
*cpuidle_get_driver(void);
125 extern struct cpuidle_driver
*cpuidle_driver_ref(void);
126 extern void cpuidle_driver_unref(void);
127 extern void cpuidle_unregister_driver(struct cpuidle_driver
*drv
);
128 extern int cpuidle_register_device(struct cpuidle_device
*dev
);
129 extern void cpuidle_unregister_device(struct cpuidle_device
*dev
);
130 extern int cpuidle_register(struct cpuidle_driver
*drv
,
131 const struct cpumask
*const coupled_cpus
);
132 extern void cpuidle_unregister(struct cpuidle_driver
*drv
);
133 extern void cpuidle_pause_and_lock(void);
134 extern void cpuidle_resume_and_unlock(void);
135 extern void cpuidle_pause(void);
136 extern void cpuidle_resume(void);
137 extern int cpuidle_enable_device(struct cpuidle_device
*dev
);
138 extern void cpuidle_disable_device(struct cpuidle_device
*dev
);
139 extern int cpuidle_play_dead(void);
141 extern struct cpuidle_driver
*cpuidle_get_cpu_driver(struct cpuidle_device
*dev
);
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
198 extern int cpuidle_register_governor(struct cpuidle_governor
*gov
);
200 static inline int cpuidle_register_governor(struct cpuidle_governor
*gov
)
204 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
205 #define CPUIDLE_DRIVER_STATE_START 1
207 #define CPUIDLE_DRIVER_STATE_START 0
210 #endif /* _LINUX_CPUIDLE_H */