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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 use_deepest_state:1;
78 unsigned int cpu;
79
80 int last_residency;
81 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
82 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
83 struct cpuidle_driver_kobj *kobj_driver;
84 struct cpuidle_device_kobj *kobj_dev;
85 struct list_head device_list;
86
87#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
88 cpumask_t coupled_cpus;
89 struct cpuidle_coupled *coupled;
90#endif
91};
92
93DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
94DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
95
96/**
97 * cpuidle_get_last_residency - retrieves the last state's residency time
98 * @dev: the target CPU
99 */
100static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
101{
102 return dev->last_residency;
103}
104
105
106/****************************
107 * CPUIDLE DRIVER INTERFACE *
108 ****************************/
109
110struct cpuidle_driver {
111 const char *name;
112 struct module *owner;
113 int refcnt;
114
115 /* used by the cpuidle framework to setup the broadcast timer */
116 unsigned int bctimer:1;
117 /* states array must be ordered in decreasing power consumption */
118 struct cpuidle_state states[CPUIDLE_STATE_MAX];
119 int state_count;
120 int safe_state_index;
121
122 /* the driver handles the cpus in cpumask */
123 struct cpumask *cpumask;
124};
125
126#ifdef CONFIG_CPU_IDLE
127extern void disable_cpuidle(void);
128extern bool cpuidle_not_available(struct cpuidle_driver *drv,
129 struct cpuidle_device *dev);
130
131extern int cpuidle_select(struct cpuidle_driver *drv,
132 struct cpuidle_device *dev);
133extern int cpuidle_enter(struct cpuidle_driver *drv,
134 struct cpuidle_device *dev, int index);
135extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
136
137extern int cpuidle_register_driver(struct cpuidle_driver *drv);
138extern struct cpuidle_driver *cpuidle_get_driver(void);
139extern struct cpuidle_driver *cpuidle_driver_ref(void);
140extern void cpuidle_driver_unref(void);
141extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
142extern int cpuidle_register_device(struct cpuidle_device *dev);
143extern void cpuidle_unregister_device(struct cpuidle_device *dev);
144extern int cpuidle_register(struct cpuidle_driver *drv,
145 const struct cpumask *const coupled_cpus);
146extern void cpuidle_unregister(struct cpuidle_driver *drv);
147extern void cpuidle_pause_and_lock(void);
148extern void cpuidle_resume_and_unlock(void);
149extern void cpuidle_pause(void);
150extern void cpuidle_resume(void);
151extern int cpuidle_enable_device(struct cpuidle_device *dev);
152extern void cpuidle_disable_device(struct cpuidle_device *dev);
153extern int cpuidle_play_dead(void);
154
155extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
156static inline struct cpuidle_device *cpuidle_get_device(void)
157{return __this_cpu_read(cpuidle_devices); }
158#else
159static inline void disable_cpuidle(void) { }
160static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
161 struct cpuidle_device *dev)
162{return true; }
163static inline int cpuidle_select(struct cpuidle_driver *drv,
164 struct cpuidle_device *dev)
165{return -ENODEV; }
166static inline int cpuidle_enter(struct cpuidle_driver *drv,
167 struct cpuidle_device *dev, int index)
168{return -ENODEV; }
169static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
170static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
171{return -ENODEV; }
172static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
173static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
174static inline void cpuidle_driver_unref(void) {}
175static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
176static inline int cpuidle_register_device(struct cpuidle_device *dev)
177{return -ENODEV; }
178static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
179static inline int cpuidle_register(struct cpuidle_driver *drv,
180 const struct cpumask *const coupled_cpus)
181{return -ENODEV; }
182static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
183static inline void cpuidle_pause_and_lock(void) { }
184static inline void cpuidle_resume_and_unlock(void) { }
185static inline void cpuidle_pause(void) { }
186static inline void cpuidle_resume(void) { }
187static inline int cpuidle_enable_device(struct cpuidle_device *dev)
188{return -ENODEV; }
189static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
190static inline int cpuidle_play_dead(void) {return -ENODEV; }
191static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
192 struct cpuidle_device *dev) {return NULL; }
193static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
194#endif
195
196#ifdef CONFIG_CPU_IDLE
197extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
198 struct cpuidle_device *dev);
199extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201extern void cpuidle_use_deepest_state(bool enable);
202#else
203static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
204 struct cpuidle_device *dev)
205{return -ENODEV; }
206static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev)
208{return -ENODEV; }
209static inline void cpuidle_use_deepest_state(bool enable)
210{
211}
212#endif
213
214/* kernel/sched/idle.c */
215extern void sched_idle_set_state(struct cpuidle_state *idle_state);
216extern void default_idle_call(void);
217
218#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
219void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
220#else
221static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
222{
223}
224#endif
225
226/******************************
227 * CPUIDLE GOVERNOR INTERFACE *
228 ******************************/
229
230struct cpuidle_governor {
231 char name[CPUIDLE_NAME_LEN];
232 struct list_head governor_list;
233 unsigned int rating;
234
235 int (*enable) (struct cpuidle_driver *drv,
236 struct cpuidle_device *dev);
237 void (*disable) (struct cpuidle_driver *drv,
238 struct cpuidle_device *dev);
239
240 int (*select) (struct cpuidle_driver *drv,
241 struct cpuidle_device *dev);
242 void (*reflect) (struct cpuidle_device *dev, int index);
243};
244
245#ifdef CONFIG_CPU_IDLE
246extern int cpuidle_register_governor(struct cpuidle_governor *gov);
247#else
248static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
249{return 0;}
250#endif
251
252#ifdef CONFIG_ARCH_HAS_CPU_RELAX
253#define CPUIDLE_DRIVER_STATE_START 1
254#else
255#define CPUIDLE_DRIVER_STATE_START 0
256#endif
257
258#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
259({ \
260 int __ret; \
261 \
262 if (!idx) { \
263 cpu_do_idle(); \
264 return idx; \
265 } \
266 \
267 __ret = cpu_pm_enter(); \
268 if (!__ret) { \
269 __ret = low_level_idle_enter(idx); \
270 cpu_pm_exit(); \
271 } \
272 \
273 __ret ? -1 : idx; \
274})
275
276#endif /* _LINUX_CPUIDLE_H */