xref: /linux/include/linux/timekeeping.h (revision ca1ec8bfac8c95d0fed9e3611ea21400d1f37262)
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 extern void ktime_get_clock_ts64(clockid_t id, struct timespec64 *ts);
48 
49 /* Multigrain timestamp interfaces */
50 extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts);
51 extern void ktime_get_real_ts64_mg(struct timespec64 *ts);
52 extern unsigned long timekeeping_get_mg_floor_swaps(void);
53 
54 void getboottime64(struct timespec64 *ts);
55 
56 /*
57  * time64_t base interfaces
58  */
59 extern time64_t ktime_get_seconds(void);
60 extern time64_t __ktime_get_real_seconds(void);
61 extern time64_t ktime_get_real_seconds(void);
62 
63 /*
64  * ktime_t based interfaces
65  */
66 
67 enum tk_offsets {
68 	TK_OFFS_REAL,
69 	TK_OFFS_BOOT,
70 	TK_OFFS_TAI,
71 	TK_OFFS_MAX,
72 };
73 
74 extern ktime_t ktime_get(void);
75 extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
76 extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
77 extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
78 extern ktime_t ktime_get_raw(void);
79 extern u32 ktime_get_resolution_ns(void);
80 
81 /**
82  * ktime_get_real - get the real (wall-) time in ktime_t format
83  *
84  * Returns: real (wall) time in ktime_t format
85  */
86 static inline ktime_t ktime_get_real(void)
87 {
88 	return ktime_get_with_offset(TK_OFFS_REAL);
89 }
90 
91 static inline ktime_t ktime_get_coarse_real(void)
92 {
93 	return ktime_get_coarse_with_offset(TK_OFFS_REAL);
94 }
95 
96 /**
97  * ktime_get_boottime - Get monotonic time since boot in ktime_t format
98  *
99  * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
100  * time spent in suspend.
101  *
102  * Returns: monotonic time since boot in ktime_t format
103  */
104 static inline ktime_t ktime_get_boottime(void)
105 {
106 	return ktime_get_with_offset(TK_OFFS_BOOT);
107 }
108 
109 static inline ktime_t ktime_get_coarse_boottime(void)
110 {
111 	return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
112 }
113 
114 /**
115  * ktime_get_clocktai - Get the TAI time of day in ktime_t format
116  *
117  * Returns: the TAI time of day in ktime_t format
118  */
119 static inline ktime_t ktime_get_clocktai(void)
120 {
121 	return ktime_get_with_offset(TK_OFFS_TAI);
122 }
123 
124 static inline ktime_t ktime_get_coarse_clocktai(void)
125 {
126 	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
127 }
128 
129 static inline ktime_t ktime_get_coarse(void)
130 {
131 	struct timespec64 ts;
132 
133 	ktime_get_coarse_ts64(&ts);
134 	return timespec64_to_ktime(ts);
135 }
136 
137 static inline u64 ktime_get_coarse_ns(void)
138 {
139 	return ktime_to_ns(ktime_get_coarse());
140 }
141 
142 static inline u64 ktime_get_coarse_real_ns(void)
143 {
144 	return ktime_to_ns(ktime_get_coarse_real());
145 }
146 
147 static inline u64 ktime_get_coarse_boottime_ns(void)
148 {
149 	return ktime_to_ns(ktime_get_coarse_boottime());
150 }
151 
152 static inline u64 ktime_get_coarse_clocktai_ns(void)
153 {
154 	return ktime_to_ns(ktime_get_coarse_clocktai());
155 }
156 
157 /**
158  * ktime_mono_to_real - Convert monotonic time to clock realtime
159  * @mono: monotonic time to convert
160  *
161  * Returns: time converted to realtime clock
162  */
163 static inline ktime_t ktime_mono_to_real(ktime_t mono)
164 {
165 	return ktime_mono_to_any(mono, TK_OFFS_REAL);
166 }
167 
168 /**
169  * ktime_get_ns - Get the current time in nanoseconds
170  *
171  * Returns: current time converted to nanoseconds
172  */
173 static inline u64 ktime_get_ns(void)
174 {
175 	return ktime_to_ns(ktime_get());
176 }
177 
178 /**
179  * ktime_get_real_ns - Get the current real/wall time in nanoseconds
180  *
181  * Returns: current real time converted to nanoseconds
182  */
183 static inline u64 ktime_get_real_ns(void)
184 {
185 	return ktime_to_ns(ktime_get_real());
186 }
187 
188 /**
189  * ktime_get_boottime_ns - Get the monotonic time since boot in nanoseconds
190  *
191  * Returns: current boottime converted to nanoseconds
192  */
193 static inline u64 ktime_get_boottime_ns(void)
194 {
195 	return ktime_to_ns(ktime_get_boottime());
196 }
197 
198 /**
199  * ktime_get_clocktai_ns - Get the current TAI time of day in nanoseconds
200  *
201  * Returns: current TAI time converted to nanoseconds
202  */
203 static inline u64 ktime_get_clocktai_ns(void)
204 {
205 	return ktime_to_ns(ktime_get_clocktai());
206 }
207 
208 /**
209  * ktime_get_raw_ns - Get the raw monotonic time in nanoseconds
210  *
211  * Returns: current raw monotonic time converted to nanoseconds
212  */
213 static inline u64 ktime_get_raw_ns(void)
214 {
215 	return ktime_to_ns(ktime_get_raw());
216 }
217 
218 extern u64 ktime_get_mono_fast_ns(void);
219 extern u64 ktime_get_raw_fast_ns(void);
220 extern u64 ktime_get_boot_fast_ns(void);
221 extern u64 ktime_get_tai_fast_ns(void);
222 extern u64 ktime_get_real_fast_ns(void);
223 
224 /*
225  * timespec64/time64_t interfaces utilizing the ktime based ones
226  * for API completeness, these could be implemented more efficiently
227  * if needed.
228  */
229 static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
230 {
231 	*ts = ktime_to_timespec64(ktime_get_boottime());
232 }
233 
234 static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
235 {
236 	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
237 }
238 
239 static inline time64_t ktime_get_boottime_seconds(void)
240 {
241 	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
242 }
243 
244 static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
245 {
246 	*ts = ktime_to_timespec64(ktime_get_clocktai());
247 }
248 
249 static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
250 {
251 	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
252 }
253 
254 static inline time64_t ktime_get_clocktai_seconds(void)
255 {
256 	return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
257 }
258 
259 /*
260  * RTC specific
261  */
262 extern bool timekeeping_rtc_skipsuspend(void);
263 extern bool timekeeping_rtc_skipresume(void);
264 
265 extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
266 
267 /*
268  * Auxiliary clock interfaces
269  */
270 #ifdef CONFIG_POSIX_AUX_CLOCKS
271 extern bool ktime_get_aux(clockid_t id, ktime_t *kt);
272 extern bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt);
273 #else
274 static inline bool ktime_get_aux(clockid_t id, ktime_t *kt) { return false; }
275 static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { return false; }
276 #endif
277 
278 /**
279  * struct system_time_snapshot - Simultaneous time capture of CLOCK_MONOTONIC_RAW,
280  *				 a selected CLOCK_* and the clocksource counter value
281  * @cycles:		Clocksource counter value to produce the system times
282  * @hw_cycles:		For derived clocksources, the hardware counter value from
283  *			which @cycles was derived
284  * @systime:		The system time of the selected CLOCK ID
285  * @monoraw:		Monotonic raw system time
286  * @cs_id:		Clocksource ID
287  * @hw_csid:		Clocksource ID of the underlying hardware counter for derived
288  *			clocksources which implement the read_snapshot() callback.
289  * @clock_was_set_seq:	The sequence number of clock-was-set events
290  * @cs_was_changed_seq:	The sequence number of clocksource change events
291  * @valid:		True if the snapshot is valid
292  */
293 struct system_time_snapshot {
294 	u64			cycles;
295 	u64			hw_cycles;
296 	ktime_t			systime;
297 	ktime_t			monoraw;
298 	enum clocksource_ids	cs_id;
299 	enum clocksource_ids	hw_csid;
300 	unsigned int		clock_was_set_seq;
301 	u8			cs_was_changed_seq;
302 	u8			valid;
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 /**
322  * struct system_device_crosststamp - system/device cross-timestamp
323  *				      (synchronized capture)
324  * @clock_id:		System time Clock ID to capture
325  * @device:		Device time
326  * @sys_counter:	Clocksource counter value simultaneous with device time
327  * @sys_systime:	System time for @clock_id
328  * @sys_monoraw:	Monotonic raw simultaneous with device time
329  */
330 struct system_device_crosststamp {
331 	clockid_t			clock_id;
332 	ktime_t				device;
333 	struct system_counterval_t	sys_counter;
334 	ktime_t				sys_systime;
335 	ktime_t				sys_monoraw;
336 };
337 
338 extern bool ktime_real_to_base_clock(ktime_t treal,
339 				     enum clocksource_ids base_id, u64 *cycles);
340 extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);
341 
342 /*
343  * Get cross timestamp between system clock and device clock
344  */
345 extern int get_device_system_crosststamp(
346 			int (*get_time_fn)(ktime_t *device_time,
347 				struct system_counterval_t *system_counterval,
348 				void *ctx),
349 			void *ctx,
350 			struct system_time_snapshot *history,
351 			struct system_device_crosststamp *xtstamp);
352 
353 /*
354  * Simultaneously snapshot a given clock with MONOTONIC_RAW and the underlying
355  * clocksource counter value.
356  */
357 extern void ktime_get_snapshot_id(clockid_t clock_id, struct system_time_snapshot *systime_snapshot);
358 
359 /*
360  * Persistent clock related interfaces
361  */
362 extern int persistent_clock_is_local;
363 
364 extern void read_persistent_clock64(struct timespec64 *ts);
365 void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
366 					  struct timespec64 *boot_offset);
367 #ifdef CONFIG_GENERIC_CMOS_UPDATE
368 extern int update_persistent_clock64(struct timespec64 now);
369 #endif
370 
371 #endif
372