Line data Source code
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 :
22 : struct module;
23 :
24 : struct cpuidle_device;
25 : struct cpuidle_driver;
26 :
27 :
28 : /****************************
29 : * CPUIDLE DEVICE INTERFACE *
30 : ****************************/
31 :
32 : #define CPUIDLE_STATE_DISABLED_BY_USER BIT(0)
33 : #define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1)
34 :
35 : struct cpuidle_state_usage {
36 : unsigned long long disable;
37 : unsigned long long usage;
38 : u64 time_ns;
39 : unsigned long long above; /* Number of times it's been too deep */
40 : unsigned long long below; /* Number of times it's been too shallow */
41 : unsigned long long rejected; /* Number of times idle entry was rejected */
42 : #ifdef CONFIG_SUSPEND
43 : unsigned long long s2idle_usage;
44 : unsigned long long s2idle_time; /* in US */
45 : #endif
46 : };
47 :
48 : struct cpuidle_state {
49 : char name[CPUIDLE_NAME_LEN];
50 : char desc[CPUIDLE_DESC_LEN];
51 :
52 : u64 exit_latency_ns;
53 : u64 target_residency_ns;
54 : unsigned int flags;
55 : unsigned int exit_latency; /* in US */
56 : int power_usage; /* in mW */
57 : unsigned int target_residency; /* in US */
58 :
59 : int (*enter) (struct cpuidle_device *dev,
60 : struct cpuidle_driver *drv,
61 : int index);
62 :
63 : int (*enter_dead) (struct cpuidle_device *dev, int index);
64 :
65 : /*
66 : * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
67 : * suspended, so it must not re-enable interrupts at any point (even
68 : * temporarily) or attempt to change states of clock event devices.
69 : *
70 : * This callback may point to the same function as ->enter if all of
71 : * the above requirements are met by it.
72 : */
73 : int (*enter_s2idle)(struct cpuidle_device *dev,
74 : struct cpuidle_driver *drv,
75 : int index);
76 : };
77 :
78 : /* Idle State Flags */
79 : #define CPUIDLE_FLAG_NONE (0x00)
80 : #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
81 : #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
82 : #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
83 : #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
84 : #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
85 : #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */
86 : #define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */
87 :
88 : struct cpuidle_device_kobj;
89 : struct cpuidle_state_kobj;
90 : struct cpuidle_driver_kobj;
91 :
92 : struct cpuidle_device {
93 : unsigned int registered:1;
94 : unsigned int enabled:1;
95 : unsigned int poll_time_limit:1;
96 : unsigned int cpu;
97 : ktime_t next_hrtimer;
98 :
99 : int last_state_idx;
100 : u64 last_residency_ns;
101 : u64 poll_limit_ns;
102 : u64 forced_idle_latency_limit_ns;
103 : struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
104 : struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
105 : struct cpuidle_driver_kobj *kobj_driver;
106 : struct cpuidle_device_kobj *kobj_dev;
107 : struct list_head device_list;
108 :
109 : #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
110 : cpumask_t coupled_cpus;
111 : struct cpuidle_coupled *coupled;
112 : #endif
113 : };
114 :
115 : DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
116 : DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
117 :
118 : /****************************
119 : * CPUIDLE DRIVER INTERFACE *
120 : ****************************/
121 :
122 : struct cpuidle_driver {
123 : const char *name;
124 : struct module *owner;
125 :
126 : /* used by the cpuidle framework to setup the broadcast timer */
127 : unsigned int bctimer:1;
128 : /* states array must be ordered in decreasing power consumption */
129 : struct cpuidle_state states[CPUIDLE_STATE_MAX];
130 : int state_count;
131 : int safe_state_index;
132 :
133 : /* the driver handles the cpus in cpumask */
134 : struct cpumask *cpumask;
135 :
136 : /* preferred governor to switch at register time */
137 : const char *governor;
138 : };
139 :
140 : #ifdef CONFIG_CPU_IDLE
141 : extern void disable_cpuidle(void);
142 : extern bool cpuidle_not_available(struct cpuidle_driver *drv,
143 : struct cpuidle_device *dev);
144 :
145 : extern int cpuidle_select(struct cpuidle_driver *drv,
146 : struct cpuidle_device *dev,
147 : bool *stop_tick);
148 : extern int cpuidle_enter(struct cpuidle_driver *drv,
149 : struct cpuidle_device *dev, int index);
150 : extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
151 : extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
152 : struct cpuidle_device *dev);
153 :
154 : extern int cpuidle_register_driver(struct cpuidle_driver *drv);
155 : extern struct cpuidle_driver *cpuidle_get_driver(void);
156 : extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
157 : bool disable);
158 : extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
159 : extern int cpuidle_register_device(struct cpuidle_device *dev);
160 : extern void cpuidle_unregister_device(struct cpuidle_device *dev);
161 : extern int cpuidle_register(struct cpuidle_driver *drv,
162 : const struct cpumask *const coupled_cpus);
163 : extern void cpuidle_unregister(struct cpuidle_driver *drv);
164 : extern void cpuidle_pause_and_lock(void);
165 : extern void cpuidle_resume_and_unlock(void);
166 : extern void cpuidle_pause(void);
167 : extern void cpuidle_resume(void);
168 : extern int cpuidle_enable_device(struct cpuidle_device *dev);
169 : extern void cpuidle_disable_device(struct cpuidle_device *dev);
170 : extern int cpuidle_play_dead(void);
171 :
172 : extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
173 : static inline struct cpuidle_device *cpuidle_get_device(void)
174 : {return __this_cpu_read(cpuidle_devices); }
175 : #else
176 : static inline void disable_cpuidle(void) { }
177 15378 : static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
178 : struct cpuidle_device *dev)
179 15378 : {return true; }
180 : static inline int cpuidle_select(struct cpuidle_driver *drv,
181 : struct cpuidle_device *dev, bool *stop_tick)
182 : {return -ENODEV; }
183 : static inline int cpuidle_enter(struct cpuidle_driver *drv,
184 : struct cpuidle_device *dev, int index)
185 : {return -ENODEV; }
186 : static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
187 : static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
188 : struct cpuidle_device *dev)
189 : {return 0; }
190 : static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
191 : {return -ENODEV; }
192 : static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
193 : static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
194 : int idx, bool disable) { }
195 : static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
196 : static inline int cpuidle_register_device(struct cpuidle_device *dev)
197 : {return -ENODEV; }
198 : static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
199 : static inline int cpuidle_register(struct cpuidle_driver *drv,
200 : const struct cpumask *const coupled_cpus)
201 : {return -ENODEV; }
202 : static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
203 : static inline void cpuidle_pause_and_lock(void) { }
204 : static inline void cpuidle_resume_and_unlock(void) { }
205 : static inline void cpuidle_pause(void) { }
206 : static inline void cpuidle_resume(void) { }
207 : static inline int cpuidle_enable_device(struct cpuidle_device *dev)
208 : {return -ENODEV; }
209 : static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
210 0 : static inline int cpuidle_play_dead(void) {return -ENODEV; }
211 15369 : static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
212 15369 : struct cpuidle_device *dev) {return NULL; }
213 15369 : static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
214 : #endif
215 :
216 : #ifdef CONFIG_CPU_IDLE
217 : extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
218 : struct cpuidle_device *dev,
219 : u64 latency_limit_ns);
220 : extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
221 : struct cpuidle_device *dev);
222 : extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
223 : #else
224 : static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
225 : struct cpuidle_device *dev,
226 : u64 latency_limit_ns)
227 : {return -ENODEV; }
228 : static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
229 : struct cpuidle_device *dev)
230 : {return -ENODEV; }
231 0 : static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
232 : {
233 0 : }
234 : #endif
235 :
236 : /* kernel/sched/idle.c */
237 : extern void sched_idle_set_state(struct cpuidle_state *idle_state);
238 : extern void default_idle_call(void);
239 :
240 : #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
241 : void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
242 : #else
243 : static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
244 : {
245 : }
246 : #endif
247 :
248 : #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
249 : void cpuidle_poll_state_init(struct cpuidle_driver *drv);
250 : #else
251 : static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
252 : #endif
253 :
254 : /******************************
255 : * CPUIDLE GOVERNOR INTERFACE *
256 : ******************************/
257 :
258 : struct cpuidle_governor {
259 : char name[CPUIDLE_NAME_LEN];
260 : struct list_head governor_list;
261 : unsigned int rating;
262 :
263 : int (*enable) (struct cpuidle_driver *drv,
264 : struct cpuidle_device *dev);
265 : void (*disable) (struct cpuidle_driver *drv,
266 : struct cpuidle_device *dev);
267 :
268 : int (*select) (struct cpuidle_driver *drv,
269 : struct cpuidle_device *dev,
270 : bool *stop_tick);
271 : void (*reflect) (struct cpuidle_device *dev, int index);
272 : };
273 :
274 : extern int cpuidle_register_governor(struct cpuidle_governor *gov);
275 : extern s64 cpuidle_governor_latency_req(unsigned int cpu);
276 :
277 : #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
278 : idx, \
279 : state, \
280 : is_retention) \
281 : ({ \
282 : int __ret = 0; \
283 : \
284 : if (!idx) { \
285 : cpu_do_idle(); \
286 : return idx; \
287 : } \
288 : \
289 : if (!is_retention) \
290 : __ret = cpu_pm_enter(); \
291 : if (!__ret) { \
292 : __ret = low_level_idle_enter(state); \
293 : if (!is_retention) \
294 : cpu_pm_exit(); \
295 : } \
296 : \
297 : __ret ? -1 : idx; \
298 : })
299 :
300 : #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
301 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
302 :
303 : #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
304 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
305 :
306 : #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
307 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
308 :
309 : #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
310 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
311 :
312 : #endif /* _LINUX_CPUIDLE_H */
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