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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/kobject.h>
17#include <linux/completion.h>
18#include <linux/hrtimer.h>
19
20#define CPUIDLE_STATE_MAX 8
21#define CPUIDLE_NAME_LEN 16
22#define CPUIDLE_DESC_LEN 32
23
24struct module;
25
26struct cpuidle_device;
27struct cpuidle_driver;
28
29
30/****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
33
34struct cpuidle_state_usage {
35 void *driver_data;
36
37 unsigned long long disable;
38 unsigned long long usage;
39 unsigned long long time; /* in US */
40};
41
42struct cpuidle_state {
43 char name[CPUIDLE_NAME_LEN];
44 char desc[CPUIDLE_DESC_LEN];
45
46 unsigned int flags;
47 unsigned int exit_latency; /* in US */
48 int power_usage; /* in mW */
49 unsigned int target_residency; /* in US */
50 bool disabled; /* disabled on all CPUs */
51
52 int (*enter) (struct cpuidle_device *dev,
53 struct cpuidle_driver *drv,
54 int index);
55
56 int (*enter_dead) (struct cpuidle_device *dev, int index);
57};
58
59/* Idle State Flags */
60#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
61#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
62
63#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
64
65/**
66 * cpuidle_get_statedata - retrieves private driver state data
67 * @st_usage: the state usage statistics
68 */
69static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
70{
71 return st_usage->driver_data;
72}
73
74/**
75 * cpuidle_set_statedata - stores private driver state data
76 * @st_usage: the state usage statistics
77 * @data: the private data
78 */
79static inline void
80cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
81{
82 st_usage->driver_data = data;
83}
84
85struct cpuidle_state_kobj {
86 struct cpuidle_state *state;
87 struct cpuidle_state_usage *state_usage;
88 struct completion kobj_unregister;
89 struct kobject kobj;
90};
91
92struct cpuidle_device {
93 unsigned int registered:1;
94 unsigned int enabled:1;
95 unsigned int cpu;
96
97 int last_residency;
98 int state_count;
99 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
100 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
101
102 struct list_head device_list;
103 struct kobject kobj;
104 struct completion kobj_unregister;
105
106#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
107 int safe_state_index;
108 cpumask_t coupled_cpus;
109 struct cpuidle_coupled *coupled;
110#endif
111};
112
113DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
114
115/**
116 * cpuidle_get_last_residency - retrieves the last state's residency time
117 * @dev: the target CPU
118 *
119 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
120 */
121static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
122{
123 return dev->last_residency;
124}
125
126
127/****************************
128 * CPUIDLE DRIVER INTERFACE *
129 ****************************/
130
131struct cpuidle_driver {
132 const char *name;
133 struct module *owner;
134
135 unsigned int power_specified:1;
136 /* set to 1 to use the core cpuidle time keeping (for all states). */
137 unsigned int en_core_tk_irqen:1;
138 struct cpuidle_state states[CPUIDLE_STATE_MAX];
139 int state_count;
140 int safe_state_index;
141};
142
143#ifdef CONFIG_CPU_IDLE
144extern void disable_cpuidle(void);
145extern int cpuidle_idle_call(void);
146extern int cpuidle_register_driver(struct cpuidle_driver *drv);
147extern struct cpuidle_driver *cpuidle_get_driver(void);
148extern struct cpuidle_driver *cpuidle_driver_ref(void);
149extern void cpuidle_driver_unref(void);
150extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
151extern int cpuidle_register_device(struct cpuidle_device *dev);
152extern void cpuidle_unregister_device(struct cpuidle_device *dev);
153
154extern void cpuidle_pause_and_lock(void);
155extern void cpuidle_resume_and_unlock(void);
156extern void cpuidle_pause(void);
157extern void cpuidle_resume(void);
158extern int cpuidle_enable_device(struct cpuidle_device *dev);
159extern void cpuidle_disable_device(struct cpuidle_device *dev);
160extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
161 struct cpuidle_driver *drv, int index,
162 int (*enter)(struct cpuidle_device *dev,
163 struct cpuidle_driver *drv, int index));
164extern int cpuidle_play_dead(void);
165
166#else
167static inline void disable_cpuidle(void) { }
168static inline int cpuidle_idle_call(void) { return -ENODEV; }
169static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
170{return -ENODEV; }
171static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
172static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
173static inline void cpuidle_driver_unref(void) {}
174static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
175static inline int cpuidle_register_device(struct cpuidle_device *dev)
176{return -ENODEV; }
177static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
178
179static inline void cpuidle_pause_and_lock(void) { }
180static inline void cpuidle_resume_and_unlock(void) { }
181static inline void cpuidle_pause(void) { }
182static inline void cpuidle_resume(void) { }
183static inline int cpuidle_enable_device(struct cpuidle_device *dev)
184{return -ENODEV; }
185static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
186static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
187 struct cpuidle_driver *drv, int index,
188 int (*enter)(struct cpuidle_device *dev,
189 struct cpuidle_driver *drv, int index))
190{ return -ENODEV; }
191static inline int cpuidle_play_dead(void) {return -ENODEV; }
192
193#endif
194
195#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
196void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
197#else
198static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
199{
200}
201#endif
202
203/******************************
204 * CPUIDLE GOVERNOR INTERFACE *
205 ******************************/
206
207struct cpuidle_governor {
208 char name[CPUIDLE_NAME_LEN];
209 struct list_head governor_list;
210 unsigned int rating;
211
212 int (*enable) (struct cpuidle_driver *drv,
213 struct cpuidle_device *dev);
214 void (*disable) (struct cpuidle_driver *drv,
215 struct cpuidle_device *dev);
216
217 int (*select) (struct cpuidle_driver *drv,
218 struct cpuidle_device *dev);
219 void (*reflect) (struct cpuidle_device *dev, int index);
220
221 struct module *owner;
222};
223
224#ifdef CONFIG_CPU_IDLE
225
226extern int cpuidle_register_governor(struct cpuidle_governor *gov);
227extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
228
229#else
230
231static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
232{return 0;}
233static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
234
235#endif
236
237#ifdef CONFIG_ARCH_HAS_CPU_RELAX
238#define CPUIDLE_DRIVER_STATE_START 1
239#else
240#define CPUIDLE_DRIVER_STATE_START 0
241#endif
242
243#endif /* _LINUX_CPUIDLE_H */