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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 * CPUs execute ->enter_freeze with the local tick or entire timekeeping
56 * suspended, so it must not re-enable interrupts at any point (even
57 * temporarily) or attempt to change states of clock event devices.
58 */
59 void (*enter_freeze) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
61 int index);
62};
63
64/* Idle State Flags */
65#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
66#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
67
68#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
69
70struct cpuidle_device_kobj;
71struct cpuidle_state_kobj;
72struct cpuidle_driver_kobj;
73
74struct cpuidle_device {
75 unsigned int registered:1;
76 unsigned int enabled:1;
77 unsigned int cpu;
78
79 int last_residency;
80 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
81 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
82 struct cpuidle_driver_kobj *kobj_driver;
83 struct cpuidle_device_kobj *kobj_dev;
84 struct list_head device_list;
85
86#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
87 cpumask_t coupled_cpus;
88 struct cpuidle_coupled *coupled;
89#endif
90};
91
92DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
93DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
94
95/**
96 * cpuidle_get_last_residency - retrieves the last state's residency time
97 * @dev: the target CPU
98 */
99static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
100{
101 return dev->last_residency;
102}
103
104
105/****************************
106 * CPUIDLE DRIVER INTERFACE *
107 ****************************/
108
109struct cpuidle_driver {
110 const char *name;
111 struct module *owner;
112 int refcnt;
113
114 /* used by the cpuidle framework to setup the broadcast timer */
115 unsigned int bctimer:1;
116 /* states array must be ordered in decreasing power consumption */
117 struct cpuidle_state states[CPUIDLE_STATE_MAX];
118 int state_count;
119 int safe_state_index;
120
121 /* the driver handles the cpus in cpumask */
122 struct cpumask *cpumask;
123};
124
125#ifdef CONFIG_CPU_IDLE
126extern void disable_cpuidle(void);
127extern bool cpuidle_not_available(struct cpuidle_driver *drv,
128 struct cpuidle_device *dev);
129
130extern int cpuidle_select(struct cpuidle_driver *drv,
131 struct cpuidle_device *dev);
132extern int cpuidle_enter(struct cpuidle_driver *drv,
133 struct cpuidle_device *dev, int index);
134extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
135
136extern int cpuidle_register_driver(struct cpuidle_driver *drv);
137extern struct cpuidle_driver *cpuidle_get_driver(void);
138extern struct cpuidle_driver *cpuidle_driver_ref(void);
139extern void cpuidle_driver_unref(void);
140extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
141extern int cpuidle_register_device(struct cpuidle_device *dev);
142extern void cpuidle_unregister_device(struct cpuidle_device *dev);
143extern int cpuidle_register(struct cpuidle_driver *drv,
144 const struct cpumask *const coupled_cpus);
145extern void cpuidle_unregister(struct cpuidle_driver *drv);
146extern void cpuidle_pause_and_lock(void);
147extern void cpuidle_resume_and_unlock(void);
148extern void cpuidle_pause(void);
149extern void cpuidle_resume(void);
150extern int cpuidle_enable_device(struct cpuidle_device *dev);
151extern void cpuidle_disable_device(struct cpuidle_device *dev);
152extern int cpuidle_play_dead(void);
153
154extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
155#else
156static inline void disable_cpuidle(void) { }
157static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
158 struct cpuidle_device *dev)
159{return true; }
160static inline int cpuidle_select(struct cpuidle_driver *drv,
161 struct cpuidle_device *dev)
162{return -ENODEV; }
163static inline int cpuidle_enter(struct cpuidle_driver *drv,
164 struct cpuidle_device *dev, int index)
165{return -ENODEV; }
166static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
167static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
168{return -ENODEV; }
169static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
170static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
171static inline void cpuidle_driver_unref(void) {}
172static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
173static inline int cpuidle_register_device(struct cpuidle_device *dev)
174{return -ENODEV; }
175static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
176static inline int cpuidle_register(struct cpuidle_driver *drv,
177 const struct cpumask *const coupled_cpus)
178{return -ENODEV; }
179static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
180static inline void cpuidle_pause_and_lock(void) { }
181static inline void cpuidle_resume_and_unlock(void) { }
182static inline void cpuidle_pause(void) { }
183static inline void cpuidle_resume(void) { }
184static inline int cpuidle_enable_device(struct cpuidle_device *dev)
185{return -ENODEV; }
186static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
187static inline int cpuidle_play_dead(void) {return -ENODEV; }
188static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
189 struct cpuidle_device *dev) {return NULL; }
190#endif
191
192#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
193extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
194 struct cpuidle_device *dev);
195extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
196 struct cpuidle_device *dev);
197#else
198static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
199 struct cpuidle_device *dev)
200{return -ENODEV; }
201static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
202 struct cpuidle_device *dev)
203{return -ENODEV; }
204#endif
205
206/* kernel/sched/idle.c */
207extern void sched_idle_set_state(struct cpuidle_state *idle_state);
208extern void default_idle_call(void);
209
210#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
211void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
212#else
213static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
214{
215}
216#endif
217
218/******************************
219 * CPUIDLE GOVERNOR INTERFACE *
220 ******************************/
221
222struct cpuidle_governor {
223 char name[CPUIDLE_NAME_LEN];
224 struct list_head governor_list;
225 unsigned int rating;
226
227 int (*enable) (struct cpuidle_driver *drv,
228 struct cpuidle_device *dev);
229 void (*disable) (struct cpuidle_driver *drv,
230 struct cpuidle_device *dev);
231
232 int (*select) (struct cpuidle_driver *drv,
233 struct cpuidle_device *dev);
234 void (*reflect) (struct cpuidle_device *dev, int index);
235
236 struct module *owner;
237};
238
239#ifdef CONFIG_CPU_IDLE
240extern int cpuidle_register_governor(struct cpuidle_governor *gov);
241#else
242static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
243{return 0;}
244#endif
245
246#ifdef CONFIG_ARCH_HAS_CPU_RELAX
247#define CPUIDLE_DRIVER_STATE_START 1
248#else
249#define CPUIDLE_DRIVER_STATE_START 0
250#endif
251
252#endif /* _LINUX_CPUIDLE_H */