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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/hrtimer.h>
17
18#define CPUIDLE_STATE_MAX 10
19#define CPUIDLE_NAME_LEN 16
20#define CPUIDLE_DESC_LEN 32
21
22struct module;
23
24struct cpuidle_device;
25struct cpuidle_driver;
26
27
28/****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
31
32struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
36};
37
38struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
41
42 unsigned int flags;
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 */
47
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
50 int index);
51
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
53};
54
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 */
59
60#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
61
62struct cpuidle_device_kobj;
63struct cpuidle_state_kobj;
64struct cpuidle_driver_kobj;
65
66struct cpuidle_device {
67 unsigned int registered:1;
68 unsigned int enabled:1;
69 unsigned int cpu;
70
71 int last_residency;
72 int state_count;
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;
78
79#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
80 int safe_state_index;
81 cpumask_t coupled_cpus;
82 struct cpuidle_coupled *coupled;
83#endif
84};
85
86DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
87
88/**
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
91 *
92 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
93 */
94static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
95{
96 return dev->last_residency;
97}
98
99
100/****************************
101 * CPUIDLE DRIVER INTERFACE *
102 ****************************/
103
104struct cpuidle_driver {
105 const char *name;
106 struct module *owner;
107 int refcnt;
108
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];
113 int state_count;
114 int safe_state_index;
115
116 /* the driver handles the cpus in cpumask */
117 struct cpumask *cpumask;
118};
119
120#ifdef CONFIG_CPU_IDLE
121extern void disable_cpuidle(void);
122extern int cpuidle_idle_call(void);
123extern int cpuidle_register_driver(struct cpuidle_driver *drv);
124extern struct cpuidle_driver *cpuidle_get_driver(void);
125extern struct cpuidle_driver *cpuidle_driver_ref(void);
126extern void cpuidle_driver_unref(void);
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);
130extern int cpuidle_register(struct cpuidle_driver *drv,
131 const struct cpumask *const coupled_cpus);
132extern void cpuidle_unregister(struct cpuidle_driver *drv);
133extern void cpuidle_pause_and_lock(void);
134extern void cpuidle_resume_and_unlock(void);
135extern void cpuidle_pause(void);
136extern void cpuidle_resume(void);
137extern int cpuidle_enable_device(struct cpuidle_device *dev);
138extern void cpuidle_disable_device(struct cpuidle_device *dev);
139extern int cpuidle_play_dead(void);
140
141extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
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) { }
154static inline int cpuidle_register(struct cpuidle_driver *drv,
155 const struct cpumask *const coupled_cpus)
156{return -ENODEV; }
157static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
158static inline void cpuidle_pause_and_lock(void) { }
159static inline void cpuidle_resume_and_unlock(void) { }
160static inline void cpuidle_pause(void) { }
161static inline void cpuidle_resume(void) { }
162static inline int cpuidle_enable_device(struct cpuidle_device *dev)
163{return -ENODEV; }
164static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
165static inline int cpuidle_play_dead(void) {return -ENODEV; }
166#endif
167
168#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
169void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
170#else
171static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
172{
173}
174#endif
175
176/******************************
177 * CPUIDLE GOVERNOR INTERFACE *
178 ******************************/
179
180struct cpuidle_governor {
181 char name[CPUIDLE_NAME_LEN];
182 struct list_head governor_list;
183 unsigned int rating;
184
185 int (*enable) (struct cpuidle_driver *drv,
186 struct cpuidle_device *dev);
187 void (*disable) (struct cpuidle_driver *drv,
188 struct cpuidle_device *dev);
189
190 int (*select) (struct cpuidle_driver *drv,
191 struct cpuidle_device *dev);
192 void (*reflect) (struct cpuidle_device *dev, int index);
193
194 struct module *owner;
195};
196
197#ifdef CONFIG_CPU_IDLE
198extern int cpuidle_register_governor(struct cpuidle_governor *gov);
199#else
200static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
201{return 0;}
202#endif
203
204#ifdef CONFIG_ARCH_HAS_CPU_RELAX
205#define CPUIDLE_DRIVER_STATE_START 1
206#else
207#define CPUIDLE_DRIVER_STATE_START 0
208#endif
209
210#endif /* _LINUX_CPUIDLE_H */