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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/module.h>
17#include <linux/kobject.h>
18#include <linux/completion.h>
19
20#define CPUIDLE_STATE_MAX 8
21#define CPUIDLE_NAME_LEN 16
22#define CPUIDLE_DESC_LEN 32
23
24struct cpuidle_device;
25
26
27/****************************
28 * CPUIDLE DEVICE INTERFACE *
29 ****************************/
30
31struct cpuidle_state {
32 char name[CPUIDLE_NAME_LEN];
33 char desc[CPUIDLE_DESC_LEN];
34 void *driver_data;
35
36 unsigned int flags;
37 unsigned int exit_latency; /* in US */
38 unsigned int power_usage; /* in mW */
39 unsigned int target_residency; /* in US */
40
41 unsigned long long usage;
42 unsigned long long time; /* in US */
43
44 int (*enter) (struct cpuidle_device *dev,
45 struct cpuidle_state *state);
46};
47
48/* Idle State Flags */
49#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
50#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
51#define CPUIDLE_FLAG_POLL (0x10) /* no latency, no savings */
52#define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */
53#define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */
54#define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */
55
56#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
57
58/**
59 * cpuidle_get_statedata - retrieves private driver state data
60 * @state: the state
61 */
62static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
63{
64 return state->driver_data;
65}
66
67/**
68 * cpuidle_set_statedata - stores private driver state data
69 * @state: the state
70 * @data: the private data
71 */
72static inline void
73cpuidle_set_statedata(struct cpuidle_state *state, void *data)
74{
75 state->driver_data = data;
76}
77
78struct cpuidle_state_kobj {
79 struct cpuidle_state *state;
80 struct completion kobj_unregister;
81 struct kobject kobj;
82};
83
84struct cpuidle_device {
85 unsigned int enabled:1;
86 unsigned int cpu;
87
88 int last_residency;
89 int state_count;
90 struct cpuidle_state states[CPUIDLE_STATE_MAX];
91 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
92 struct cpuidle_state *last_state;
93
94 struct list_head device_list;
95 struct kobject kobj;
96 struct completion kobj_unregister;
97 void *governor_data;
98 struct cpuidle_state *safe_state;
99};
100
101DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
102
103/**
104 * cpuidle_get_last_residency - retrieves the last state's residency time
105 * @dev: the target CPU
106 *
107 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
108 */
109static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
110{
111 return dev->last_residency;
112}
113
114
115/****************************
116 * CPUIDLE DRIVER INTERFACE *
117 ****************************/
118
119struct cpuidle_driver {
120 char name[CPUIDLE_NAME_LEN];
121 struct module *owner;
122};
123
124#ifdef CONFIG_CPU_IDLE
125
126extern int cpuidle_register_driver(struct cpuidle_driver *drv);
127extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
128extern int cpuidle_register_device(struct cpuidle_device *dev);
129extern void cpuidle_unregister_device(struct cpuidle_device *dev);
130
131extern void cpuidle_pause_and_lock(void);
132extern void cpuidle_resume_and_unlock(void);
133extern int cpuidle_enable_device(struct cpuidle_device *dev);
134extern void cpuidle_disable_device(struct cpuidle_device *dev);
135
136#else
137
138static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
139{return 0;}
140static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
141static inline int cpuidle_register_device(struct cpuidle_device *dev)
142{return 0;}
143static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
144
145static inline void cpuidle_pause_and_lock(void) { }
146static inline void cpuidle_resume_and_unlock(void) { }
147static inline int cpuidle_enable_device(struct cpuidle_device *dev)
148{return 0;}
149static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
150
151#endif
152
153/******************************
154 * CPUIDLE GOVERNOR INTERFACE *
155 ******************************/
156
157struct cpuidle_governor {
158 char name[CPUIDLE_NAME_LEN];
159 struct list_head governor_list;
160 unsigned int rating;
161
162 int (*enable) (struct cpuidle_device *dev);
163 void (*disable) (struct cpuidle_device *dev);
164
165 int (*select) (struct cpuidle_device *dev);
166 void (*reflect) (struct cpuidle_device *dev);
167
168 struct module *owner;
169};
170
171#ifdef CONFIG_CPU_IDLE
172
173extern int cpuidle_register_governor(struct cpuidle_governor *gov);
174extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
175
176#else
177
178static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
179{return 0;}
180static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
181
182#endif
183
184#ifdef CONFIG_ARCH_HAS_CPU_RELAX
185#define CPUIDLE_DRIVER_STATE_START 1
186#else
187#define CPUIDLE_DRIVER_STATE_START 0
188#endif
189
190#endif /* _LINUX_CPUIDLE_H */