tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
23struct cpuidle_device;
24
25
26/****************************
27 * CPUIDLE DEVICE INTERFACE *
28 ****************************/
29
30struct cpuidle_state {
31 char name[CPUIDLE_NAME_LEN];
32 void *driver_data;
33
34 unsigned int flags;
35 unsigned int exit_latency; /* in US */
36 unsigned int power_usage; /* in mW */
37 unsigned int target_residency; /* in US */
38
39 unsigned int usage;
40 unsigned int time; /* in US */
41
42 int (*enter) (struct cpuidle_device *dev,
43 struct cpuidle_state *state);
44};
45
46/* Idle State Flags */
47#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
48#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
49#define CPUIDLE_FLAG_SHALLOW (0x10) /* low latency, minimal savings */
50#define CPUIDLE_FLAG_BALANCED (0x20) /* medium latency, moderate savings */
51#define CPUIDLE_FLAG_DEEP (0x40) /* high latency, large savings */
52
53#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
54
55/**
56 * cpuidle_get_statedata - retrieves private driver state data
57 * @state: the state
58 */
59static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
60{
61 return state->driver_data;
62}
63
64/**
65 * cpuidle_set_statedata - stores private driver state data
66 * @state: the state
67 * @data: the private data
68 */
69static inline void
70cpuidle_set_statedata(struct cpuidle_state *state, void *data)
71{
72 state->driver_data = data;
73}
74
75struct cpuidle_state_kobj {
76 struct cpuidle_state *state;
77 struct completion kobj_unregister;
78 struct kobject kobj;
79};
80
81struct cpuidle_device {
82 int enabled:1;
83 unsigned int cpu;
84
85 int last_residency;
86 int state_count;
87 struct cpuidle_state states[CPUIDLE_STATE_MAX];
88 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
89 struct cpuidle_state *last_state;
90
91 struct list_head device_list;
92 struct kobject kobj;
93 struct completion kobj_unregister;
94 void *governor_data;
95};
96
97DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
98
99/**
100 * cpuidle_get_last_residency - retrieves the last state's residency time
101 * @dev: the target CPU
102 *
103 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
104 */
105static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
106{
107 return dev->last_residency;
108}
109
110
111/****************************
112 * CPUIDLE DRIVER INTERFACE *
113 ****************************/
114
115struct cpuidle_driver {
116 char name[CPUIDLE_NAME_LEN];
117 struct module *owner;
118};
119
120#ifdef CONFIG_CPU_IDLE
121
122extern int cpuidle_register_driver(struct cpuidle_driver *drv);
123extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
124extern int cpuidle_register_device(struct cpuidle_device *dev);
125extern void cpuidle_unregister_device(struct cpuidle_device *dev);
126
127extern void cpuidle_pause_and_lock(void);
128extern void cpuidle_resume_and_unlock(void);
129extern int cpuidle_enable_device(struct cpuidle_device *dev);
130extern void cpuidle_disable_device(struct cpuidle_device *dev);
131
132#else
133
134static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
135{return 0;}
136static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
137static inline int cpuidle_register_device(struct cpuidle_device *dev)
138{return 0;}
139static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
140
141static inline void cpuidle_pause_and_lock(void) { }
142static inline void cpuidle_resume_and_unlock(void) { }
143static inline int cpuidle_enable_device(struct cpuidle_device *dev)
144{return 0;}
145static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
146
147#endif
148
149/******************************
150 * CPUIDLE GOVERNOR INTERFACE *
151 ******************************/
152
153struct cpuidle_governor {
154 char name[CPUIDLE_NAME_LEN];
155 struct list_head governor_list;
156 unsigned int rating;
157
158 int (*enable) (struct cpuidle_device *dev);
159 void (*disable) (struct cpuidle_device *dev);
160
161 int (*select) (struct cpuidle_device *dev);
162 void (*reflect) (struct cpuidle_device *dev);
163
164 struct module *owner;
165};
166
167#ifdef CONFIG_CPU_IDLE
168
169extern int cpuidle_register_governor(struct cpuidle_governor *gov);
170extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
171
172#else
173
174static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
175{return 0;}
176static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
177
178#endif
179
180#endif /* _LINUX_CPUIDLE_H */