xref: /linux/include/linux/timekeeping.h (revision f49040c7aaa5532a1f94355ef5073c49e6b32349)
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 /* Multigrain timestamp interfaces */
49 extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts);
50 extern void ktime_get_real_ts64_mg(struct timespec64 *ts);
51 extern unsigned long timekeeping_get_mg_floor_swaps(void);
52 
53 void getboottime64(struct timespec64 *ts);
54 
55 /*
56  * time64_t base interfaces
57  */
58 extern time64_t ktime_get_seconds(void);
59 extern time64_t __ktime_get_real_seconds(void);
60 extern time64_t ktime_get_real_seconds(void);
61 
62 /*
63  * ktime_t based interfaces
64  */
65 
66 enum tk_offsets {
67 	TK_OFFS_REAL,
68 	TK_OFFS_BOOT,
69 	TK_OFFS_TAI,
70 	TK_OFFS_MAX,
71 };
72 
73 extern ktime_t ktime_get(void);
74 extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
75 extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
76 extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
77 extern ktime_t ktime_get_raw(void);
78 extern u32 ktime_get_resolution_ns(void);
79 
80 /**
81  * ktime_get_real - get the real (wall-) time in ktime_t format
82  *
83  * Returns: real (wall) time in ktime_t format
84  */
ktime_get_real(void)85 static inline ktime_t ktime_get_real(void)
86 {
87 	return ktime_get_with_offset(TK_OFFS_REAL);
88 }
89 
ktime_get_coarse_real(void)90 static inline ktime_t ktime_get_coarse_real(void)
91 {
92 	return ktime_get_coarse_with_offset(TK_OFFS_REAL);
93 }
94 
95 /**
96  * ktime_get_boottime - Get monotonic time since boot in ktime_t format
97  *
98  * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
99  * time spent in suspend.
100  *
101  * Returns: monotonic time since boot in ktime_t format
102  */
ktime_get_boottime(void)103 static inline ktime_t ktime_get_boottime(void)
104 {
105 	return ktime_get_with_offset(TK_OFFS_BOOT);
106 }
107 
ktime_get_coarse_boottime(void)108 static inline ktime_t ktime_get_coarse_boottime(void)
109 {
110 	return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
111 }
112 
113 /**
114  * ktime_get_clocktai - Get the TAI time of day in ktime_t format
115  *
116  * Returns: the TAI time of day in ktime_t format
117  */
ktime_get_clocktai(void)118 static inline ktime_t ktime_get_clocktai(void)
119 {
120 	return ktime_get_with_offset(TK_OFFS_TAI);
121 }
122 
ktime_get_coarse_clocktai(void)123 static inline ktime_t ktime_get_coarse_clocktai(void)
124 {
125 	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
126 }
127 
ktime_get_coarse(void)128 static inline ktime_t ktime_get_coarse(void)
129 {
130 	struct timespec64 ts;
131 
132 	ktime_get_coarse_ts64(&ts);
133 	return timespec64_to_ktime(ts);
134 }
135 
ktime_get_coarse_ns(void)136 static inline u64 ktime_get_coarse_ns(void)
137 {
138 	return ktime_to_ns(ktime_get_coarse());
139 }
140 
ktime_get_coarse_real_ns(void)141 static inline u64 ktime_get_coarse_real_ns(void)
142 {
143 	return ktime_to_ns(ktime_get_coarse_real());
144 }
145 
ktime_get_coarse_boottime_ns(void)146 static inline u64 ktime_get_coarse_boottime_ns(void)
147 {
148 	return ktime_to_ns(ktime_get_coarse_boottime());
149 }
150 
ktime_get_coarse_clocktai_ns(void)151 static inline u64 ktime_get_coarse_clocktai_ns(void)
152 {
153 	return ktime_to_ns(ktime_get_coarse_clocktai());
154 }
155 
156 /**
157  * ktime_mono_to_real - Convert monotonic time to clock realtime
158  * @mono: monotonic time to convert
159  *
160  * Returns: time converted to realtime clock
161  */
ktime_mono_to_real(ktime_t mono)162 static inline ktime_t ktime_mono_to_real(ktime_t mono)
163 {
164 	return ktime_mono_to_any(mono, TK_OFFS_REAL);
165 }
166 
167 /**
168  * ktime_get_ns - Get the current time in nanoseconds
169  *
170  * Returns: current time converted to nanoseconds
171  */
ktime_get_ns(void)172 static inline u64 ktime_get_ns(void)
173 {
174 	return ktime_to_ns(ktime_get());
175 }
176 
177 /**
178  * ktime_get_real_ns - Get the current real/wall time in nanoseconds
179  *
180  * Returns: current real time converted to nanoseconds
181  */
ktime_get_real_ns(void)182 static inline u64 ktime_get_real_ns(void)
183 {
184 	return ktime_to_ns(ktime_get_real());
185 }
186 
187 /**
188  * ktime_get_boottime_ns - Get the monotonic time since boot in nanoseconds
189  *
190  * Returns: current boottime converted to nanoseconds
191  */
ktime_get_boottime_ns(void)192 static inline u64 ktime_get_boottime_ns(void)
193 {
194 	return ktime_to_ns(ktime_get_boottime());
195 }
196 
197 /**
198  * ktime_get_clocktai_ns - Get the current TAI time of day in nanoseconds
199  *
200  * Returns: current TAI time converted to nanoseconds
201  */
ktime_get_clocktai_ns(void)202 static inline u64 ktime_get_clocktai_ns(void)
203 {
204 	return ktime_to_ns(ktime_get_clocktai());
205 }
206 
207 /**
208  * ktime_get_raw_ns - Get the raw monotonic time in nanoseconds
209  *
210  * Returns: current raw monotonic time converted to nanoseconds
211  */
ktime_get_raw_ns(void)212 static inline u64 ktime_get_raw_ns(void)
213 {
214 	return ktime_to_ns(ktime_get_raw());
215 }
216 
217 extern u64 ktime_get_mono_fast_ns(void);
218 extern u64 ktime_get_raw_fast_ns(void);
219 extern u64 ktime_get_boot_fast_ns(void);
220 extern u64 ktime_get_tai_fast_ns(void);
221 extern u64 ktime_get_real_fast_ns(void);
222 
223 /*
224  * timespec64/time64_t interfaces utilizing the ktime based ones
225  * for API completeness, these could be implemented more efficiently
226  * if needed.
227  */
ktime_get_boottime_ts64(struct timespec64 * ts)228 static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
229 {
230 	*ts = ktime_to_timespec64(ktime_get_boottime());
231 }
232 
ktime_get_coarse_boottime_ts64(struct timespec64 * ts)233 static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
234 {
235 	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
236 }
237 
ktime_get_boottime_seconds(void)238 static inline time64_t ktime_get_boottime_seconds(void)
239 {
240 	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
241 }
242 
ktime_get_clocktai_ts64(struct timespec64 * ts)243 static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
244 {
245 	*ts = ktime_to_timespec64(ktime_get_clocktai());
246 }
247 
ktime_get_coarse_clocktai_ts64(struct timespec64 * ts)248 static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
249 {
250 	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
251 }
252 
ktime_get_clocktai_seconds(void)253 static inline time64_t ktime_get_clocktai_seconds(void)
254 {
255 	return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
256 }
257 
258 /*
259  * RTC specific
260  */
261 extern bool timekeeping_rtc_skipsuspend(void);
262 extern bool timekeeping_rtc_skipresume(void);
263 
264 extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
265 
266 /**
267  * struct system_time_snapshot - simultaneous raw/real time capture with
268  *				 counter value
269  * @cycles:	Clocksource counter value to produce the system times
270  * @real:	Realtime system time
271  * @boot:	Boot time
272  * @raw:	Monotonic raw system time
273  * @cs_id:	Clocksource ID
274  * @clock_was_set_seq:	The sequence number of clock-was-set events
275  * @cs_was_changed_seq:	The sequence number of clocksource change events
276  */
277 struct system_time_snapshot {
278 	u64			cycles;
279 	ktime_t			real;
280 	ktime_t			boot;
281 	ktime_t			raw;
282 	enum clocksource_ids	cs_id;
283 	unsigned int		clock_was_set_seq;
284 	u8			cs_was_changed_seq;
285 };
286 
287 /**
288  * struct system_device_crosststamp - system/device cross-timestamp
289  *				      (synchronized capture)
290  * @device:		Device time
291  * @sys_realtime:	Realtime simultaneous with device time
292  * @sys_monoraw:	Monotonic raw simultaneous with device time
293  */
294 struct system_device_crosststamp {
295 	ktime_t device;
296 	ktime_t sys_realtime;
297 	ktime_t sys_monoraw;
298 };
299 
300 /**
301  * struct system_counterval_t - system counter value with the ID of the
302  *				corresponding clocksource
303  * @cycles:	System counter value
304  * @cs_id:	Clocksource ID corresponding to system counter value. Used by
305  *		timekeeping code to verify comparability of two cycle values.
306  *		The default ID, CSID_GENERIC, does not identify a specific
307  *		clocksource.
308  * @use_nsecs:	@cycles is in nanoseconds.
309  */
310 struct system_counterval_t {
311 	u64			cycles;
312 	enum clocksource_ids	cs_id;
313 	bool			use_nsecs;
314 };
315 
316 extern bool ktime_real_to_base_clock(ktime_t treal,
317 				     enum clocksource_ids base_id, u64 *cycles);
318 extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);
319 
320 /*
321  * Get cross timestamp between system clock and device clock
322  */
323 extern int get_device_system_crosststamp(
324 			int (*get_time_fn)(ktime_t *device_time,
325 				struct system_counterval_t *system_counterval,
326 				void *ctx),
327 			void *ctx,
328 			struct system_time_snapshot *history,
329 			struct system_device_crosststamp *xtstamp);
330 
331 /*
332  * Simultaneously snapshot realtime and monotonic raw clocks
333  */
334 extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
335 
336 /*
337  * Persistent clock related interfaces
338  */
339 extern int persistent_clock_is_local;
340 
341 extern void read_persistent_clock64(struct timespec64 *ts);
342 void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
343 					  struct timespec64 *boot_offset);
344 #ifdef CONFIG_GENERIC_CMOS_UPDATE
345 extern int update_persistent_clock64(struct timespec64 now);
346 #endif
347 
348 #endif
349