xref: /linux/include/linux/timekeeping.h (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TIMEKEEPING_H
3 #define _LINUX_TIMEKEEPING_H
4 
5 #include <linux/errno.h>
6 #include <linux/clocksource_ids.h>
7 #include <linux/ktime.h>
8 
9 /* Included from linux/ktime.h */
10 
11 void timekeeping_init(void);
12 extern int timekeeping_suspended;
13 
14 /* Architecture timer tick functions: */
15 extern void legacy_timer_tick(unsigned long ticks);
16 
17 /*
18  * Get and set timeofday
19  */
20 extern int do_settimeofday64(const struct timespec64 *ts);
21 extern int do_sys_settimeofday64(const struct timespec64 *tv,
22 				 const struct timezone *tz);
23 
24 /*
25  * ktime_get() family - read the current time in a multitude of ways.
26  *
27  * The default time reference is CLOCK_MONOTONIC, starting at
28  * boot time but not counting the time spent in suspend.
29  * For other references, use the functions with "real", "clocktai",
30  * "boottime" and "raw" suffixes.
31  *
32  * To get the time in a different format, use the ones with
33  * "ns", "ts64" and "seconds" suffix.
34  *
35  * See Documentation/core-api/timekeeping.rst for more details.
36  */
37 
38 
39 /*
40  * timespec64 based interfaces
41  */
42 extern void ktime_get_raw_ts64(struct timespec64 *ts);
43 extern void ktime_get_ts64(struct timespec64 *ts);
44 extern void ktime_get_real_ts64(struct timespec64 *tv);
45 extern void ktime_get_coarse_ts64(struct timespec64 *ts);
46 extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
47 
48 void getboottime64(struct timespec64 *ts);
49 
50 /*
51  * time64_t base interfaces
52  */
53 extern time64_t ktime_get_seconds(void);
54 extern time64_t __ktime_get_real_seconds(void);
55 extern time64_t ktime_get_real_seconds(void);
56 
57 /*
58  * ktime_t based interfaces
59  */
60 
61 enum tk_offsets {
62 	TK_OFFS_REAL,
63 	TK_OFFS_BOOT,
64 	TK_OFFS_TAI,
65 	TK_OFFS_MAX,
66 };
67 
68 extern ktime_t ktime_get(void);
69 extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
70 extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
71 extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
72 extern ktime_t ktime_get_raw(void);
73 extern u32 ktime_get_resolution_ns(void);
74 
75 /**
76  * ktime_get_real - get the real (wall-) time in ktime_t format
77  *
78  * Returns: real (wall) time in ktime_t format
79  */
ktime_get_real(void)80 static inline ktime_t ktime_get_real(void)
81 {
82 	return ktime_get_with_offset(TK_OFFS_REAL);
83 }
84 
ktime_get_coarse_real(void)85 static inline ktime_t ktime_get_coarse_real(void)
86 {
87 	return ktime_get_coarse_with_offset(TK_OFFS_REAL);
88 }
89 
90 /**
91  * ktime_get_boottime - Get monotonic time since boot in ktime_t format
92  *
93  * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
94  * time spent in suspend.
95  *
96  * Returns: monotonic time since boot in ktime_t format
97  */
ktime_get_boottime(void)98 static inline ktime_t ktime_get_boottime(void)
99 {
100 	return ktime_get_with_offset(TK_OFFS_BOOT);
101 }
102 
ktime_get_coarse_boottime(void)103 static inline ktime_t ktime_get_coarse_boottime(void)
104 {
105 	return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
106 }
107 
108 /**
109  * ktime_get_clocktai - Get the TAI time of day in ktime_t format
110  *
111  * Returns: the TAI time of day in ktime_t format
112  */
ktime_get_clocktai(void)113 static inline ktime_t ktime_get_clocktai(void)
114 {
115 	return ktime_get_with_offset(TK_OFFS_TAI);
116 }
117 
ktime_get_coarse_clocktai(void)118 static inline ktime_t ktime_get_coarse_clocktai(void)
119 {
120 	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
121 }
122 
ktime_get_coarse(void)123 static inline ktime_t ktime_get_coarse(void)
124 {
125 	struct timespec64 ts;
126 
127 	ktime_get_coarse_ts64(&ts);
128 	return timespec64_to_ktime(ts);
129 }
130 
ktime_get_coarse_ns(void)131 static inline u64 ktime_get_coarse_ns(void)
132 {
133 	return ktime_to_ns(ktime_get_coarse());
134 }
135 
ktime_get_coarse_real_ns(void)136 static inline u64 ktime_get_coarse_real_ns(void)
137 {
138 	return ktime_to_ns(ktime_get_coarse_real());
139 }
140 
ktime_get_coarse_boottime_ns(void)141 static inline u64 ktime_get_coarse_boottime_ns(void)
142 {
143 	return ktime_to_ns(ktime_get_coarse_boottime());
144 }
145 
ktime_get_coarse_clocktai_ns(void)146 static inline u64 ktime_get_coarse_clocktai_ns(void)
147 {
148 	return ktime_to_ns(ktime_get_coarse_clocktai());
149 }
150 
151 /**
152  * ktime_mono_to_real - Convert monotonic time to clock realtime
153  * @mono: monotonic time to convert
154  *
155  * Returns: time converted to realtime clock
156  */
ktime_mono_to_real(ktime_t mono)157 static inline ktime_t ktime_mono_to_real(ktime_t mono)
158 {
159 	return ktime_mono_to_any(mono, TK_OFFS_REAL);
160 }
161 
162 /**
163  * ktime_get_ns - Get the current time in nanoseconds
164  *
165  * Returns: current time converted to nanoseconds
166  */
ktime_get_ns(void)167 static inline u64 ktime_get_ns(void)
168 {
169 	return ktime_to_ns(ktime_get());
170 }
171 
172 /**
173  * ktime_get_real_ns - Get the current real/wall time in nanoseconds
174  *
175  * Returns: current real time converted to nanoseconds
176  */
ktime_get_real_ns(void)177 static inline u64 ktime_get_real_ns(void)
178 {
179 	return ktime_to_ns(ktime_get_real());
180 }
181 
182 /**
183  * ktime_get_boottime_ns - Get the monotonic time since boot in nanoseconds
184  *
185  * Returns: current boottime converted to nanoseconds
186  */
ktime_get_boottime_ns(void)187 static inline u64 ktime_get_boottime_ns(void)
188 {
189 	return ktime_to_ns(ktime_get_boottime());
190 }
191 
192 /**
193  * ktime_get_clocktai_ns - Get the current TAI time of day in nanoseconds
194  *
195  * Returns: current TAI time converted to nanoseconds
196  */
ktime_get_clocktai_ns(void)197 static inline u64 ktime_get_clocktai_ns(void)
198 {
199 	return ktime_to_ns(ktime_get_clocktai());
200 }
201 
202 /**
203  * ktime_get_raw_ns - Get the raw monotonic time in nanoseconds
204  *
205  * Returns: current raw monotonic time converted to nanoseconds
206  */
ktime_get_raw_ns(void)207 static inline u64 ktime_get_raw_ns(void)
208 {
209 	return ktime_to_ns(ktime_get_raw());
210 }
211 
212 extern u64 ktime_get_mono_fast_ns(void);
213 extern u64 ktime_get_raw_fast_ns(void);
214 extern u64 ktime_get_boot_fast_ns(void);
215 extern u64 ktime_get_tai_fast_ns(void);
216 extern u64 ktime_get_real_fast_ns(void);
217 
218 /*
219  * timespec64/time64_t interfaces utilizing the ktime based ones
220  * for API completeness, these could be implemented more efficiently
221  * if needed.
222  */
ktime_get_boottime_ts64(struct timespec64 * ts)223 static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
224 {
225 	*ts = ktime_to_timespec64(ktime_get_boottime());
226 }
227 
ktime_get_coarse_boottime_ts64(struct timespec64 * ts)228 static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
229 {
230 	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
231 }
232 
ktime_get_boottime_seconds(void)233 static inline time64_t ktime_get_boottime_seconds(void)
234 {
235 	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
236 }
237 
ktime_get_clocktai_ts64(struct timespec64 * ts)238 static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
239 {
240 	*ts = ktime_to_timespec64(ktime_get_clocktai());
241 }
242 
ktime_get_coarse_clocktai_ts64(struct timespec64 * ts)243 static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
244 {
245 	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
246 }
247 
ktime_get_clocktai_seconds(void)248 static inline time64_t ktime_get_clocktai_seconds(void)
249 {
250 	return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
251 }
252 
253 /*
254  * RTC specific
255  */
256 extern bool timekeeping_rtc_skipsuspend(void);
257 extern bool timekeeping_rtc_skipresume(void);
258 
259 extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
260 
261 /**
262  * struct ktime_timestamps - Simultaneous mono/boot/real timestamps
263  * @mono:	Monotonic timestamp
264  * @boot:	Boottime timestamp
265  * @real:	Realtime timestamp
266  */
267 struct ktime_timestamps {
268 	u64		mono;
269 	u64		boot;
270 	u64		real;
271 };
272 
273 /**
274  * struct system_time_snapshot - simultaneous raw/real time capture with
275  *				 counter value
276  * @cycles:	Clocksource counter value to produce the system times
277  * @real:	Realtime system time
278  * @raw:	Monotonic raw system time
279  * @cs_id:	Clocksource ID
280  * @clock_was_set_seq:	The sequence number of clock-was-set events
281  * @cs_was_changed_seq:	The sequence number of clocksource change events
282  */
283 struct system_time_snapshot {
284 	u64			cycles;
285 	ktime_t			real;
286 	ktime_t			raw;
287 	enum clocksource_ids	cs_id;
288 	unsigned int		clock_was_set_seq;
289 	u8			cs_was_changed_seq;
290 };
291 
292 /**
293  * struct system_device_crosststamp - system/device cross-timestamp
294  *				      (synchronized capture)
295  * @device:		Device time
296  * @sys_realtime:	Realtime simultaneous with device time
297  * @sys_monoraw:	Monotonic raw simultaneous with device time
298  */
299 struct system_device_crosststamp {
300 	ktime_t device;
301 	ktime_t sys_realtime;
302 	ktime_t sys_monoraw;
303 };
304 
305 /**
306  * struct system_counterval_t - system counter value with the ID of the
307  *				corresponding clocksource
308  * @cycles:	System counter value
309  * @cs_id:	Clocksource ID corresponding to system counter value. Used by
310  *		timekeeping code to verify comparability of two cycle values.
311  *		The default ID, CSID_GENERIC, does not identify a specific
312  *		clocksource.
313  * @use_nsecs:	@cycles is in nanoseconds.
314  */
315 struct system_counterval_t {
316 	u64			cycles;
317 	enum clocksource_ids	cs_id;
318 	bool			use_nsecs;
319 };
320 
321 extern bool ktime_real_to_base_clock(ktime_t treal,
322 				     enum clocksource_ids base_id, u64 *cycles);
323 extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);
324 
325 /*
326  * Get cross timestamp between system clock and device clock
327  */
328 extern int get_device_system_crosststamp(
329 			int (*get_time_fn)(ktime_t *device_time,
330 				struct system_counterval_t *system_counterval,
331 				void *ctx),
332 			void *ctx,
333 			struct system_time_snapshot *history,
334 			struct system_device_crosststamp *xtstamp);
335 
336 /*
337  * Simultaneously snapshot realtime and monotonic raw clocks
338  */
339 extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
340 
341 /* NMI safe mono/boot/realtime timestamps */
342 extern void ktime_get_fast_timestamps(struct ktime_timestamps *snap);
343 
344 /*
345  * Persistent clock related interfaces
346  */
347 extern int persistent_clock_is_local;
348 
349 extern void read_persistent_clock64(struct timespec64 *ts);
350 void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
351 					  struct timespec64 *boot_offset);
352 #ifdef CONFIG_GENERIC_CMOS_UPDATE
353 extern int update_persistent_clock64(struct timespec64 now);
354 #endif
355 
356 #endif
357