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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 unsigned long long disable;
36 unsigned long long usage;
37 unsigned long long time; /* in US */
38};
39
40struct cpuidle_state {
41 char name[CPUIDLE_NAME_LEN];
42 char desc[CPUIDLE_DESC_LEN];
43
44 unsigned int flags;
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 */
49
50 int (*enter) (struct cpuidle_device *dev,
51 struct cpuidle_driver *drv,
52 int index);
53
54 int (*enter_dead) (struct cpuidle_device *dev, int index);
55};
56
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
61#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62
63struct cpuidle_device {
64 unsigned int registered:1;
65 unsigned int enabled:1;
66 unsigned int cpu;
67
68 int last_residency;
69 int state_count;
70 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
71 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
72 struct cpuidle_driver_kobj *kobj_driver;
73 struct list_head device_list;
74 struct kobject kobj;
75 struct completion kobj_unregister;
76
77#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
78 int safe_state_index;
79 cpumask_t coupled_cpus;
80 struct cpuidle_coupled *coupled;
81#endif
82};
83
84DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
85
86/**
87 * cpuidle_get_last_residency - retrieves the last state's residency time
88 * @dev: the target CPU
89 *
90 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
91 */
92static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
93{
94 return dev->last_residency;
95}
96
97
98/****************************
99 * CPUIDLE DRIVER INTERFACE *
100 ****************************/
101
102struct cpuidle_driver {
103 const char *name;
104 struct module *owner;
105 int refcnt;
106
107 /* set to 1 to use the core cpuidle time keeping (for all states). */
108 unsigned int en_core_tk_irqen:1;
109 /* states array must be ordered in decreasing power consumption */
110 struct cpuidle_state states[CPUIDLE_STATE_MAX];
111 int state_count;
112 int safe_state_index;
113};
114
115#ifdef CONFIG_CPU_IDLE
116extern void disable_cpuidle(void);
117extern int cpuidle_idle_call(void);
118extern int cpuidle_register_driver(struct cpuidle_driver *drv);
119extern struct cpuidle_driver *cpuidle_get_driver(void);
120extern struct cpuidle_driver *cpuidle_driver_ref(void);
121extern void cpuidle_driver_unref(void);
122extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
123extern int cpuidle_register_device(struct cpuidle_device *dev);
124extern void cpuidle_unregister_device(struct cpuidle_device *dev);
125
126extern void cpuidle_pause_and_lock(void);
127extern void cpuidle_resume_and_unlock(void);
128extern void cpuidle_pause(void);
129extern void cpuidle_resume(void);
130extern int cpuidle_enable_device(struct cpuidle_device *dev);
131extern void cpuidle_disable_device(struct cpuidle_device *dev);
132extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
133 struct cpuidle_driver *drv, int index,
134 int (*enter)(struct cpuidle_device *dev,
135 struct cpuidle_driver *drv, int index));
136extern int cpuidle_play_dead(void);
137
138extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
139extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
140extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
141
142#else
143static inline void disable_cpuidle(void) { }
144static inline int cpuidle_idle_call(void) { return -ENODEV; }
145static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
146{return -ENODEV; }
147static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
148static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
149static inline void cpuidle_driver_unref(void) {}
150static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
151static inline int cpuidle_register_device(struct cpuidle_device *dev)
152{return -ENODEV; }
153static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
154
155static inline void cpuidle_pause_and_lock(void) { }
156static inline void cpuidle_resume_and_unlock(void) { }
157static inline void cpuidle_pause(void) { }
158static inline void cpuidle_resume(void) { }
159static inline int cpuidle_enable_device(struct cpuidle_device *dev)
160{return -ENODEV; }
161static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
162static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
163 struct cpuidle_driver *drv, int index,
164 int (*enter)(struct cpuidle_device *dev,
165 struct cpuidle_driver *drv, int index))
166{ return -ENODEV; }
167static inline int cpuidle_play_dead(void) {return -ENODEV; }
168#endif
169
170#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
171void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
172#else
173static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
174{
175}
176#endif
177
178/******************************
179 * CPUIDLE GOVERNOR INTERFACE *
180 ******************************/
181
182struct cpuidle_governor {
183 char name[CPUIDLE_NAME_LEN];
184 struct list_head governor_list;
185 unsigned int rating;
186
187 int (*enable) (struct cpuidle_driver *drv,
188 struct cpuidle_device *dev);
189 void (*disable) (struct cpuidle_driver *drv,
190 struct cpuidle_device *dev);
191
192 int (*select) (struct cpuidle_driver *drv,
193 struct cpuidle_device *dev);
194 void (*reflect) (struct cpuidle_device *dev, int index);
195
196 struct module *owner;
197};
198
199#ifdef CONFIG_CPU_IDLE
200
201extern int cpuidle_register_governor(struct cpuidle_governor *gov);
202extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
203
204#else
205
206static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
207{return 0;}
208static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
209
210#endif
211
212#ifdef CONFIG_ARCH_HAS_CPU_RELAX
213#define CPUIDLE_DRIVER_STATE_START 1
214#else
215#define CPUIDLE_DRIVER_STATE_START 0
216#endif
217
218#endif /* _LINUX_CPUIDLE_H */