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
11void timekeeping_init(void);
12extern int timekeeping_suspended;
13
14/* Architecture timer tick functions: */
15extern void legacy_timer_tick(unsigned long ticks);
16
17/*
18 * Get and set timeofday
19 */
20extern int do_settimeofday64(const struct timespec64 *ts);
21extern 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 */
42extern void ktime_get_raw_ts64(struct timespec64 *ts);
43extern void ktime_get_ts64(struct timespec64 *ts);
44extern void ktime_get_real_ts64(struct timespec64 *tv);
45extern void ktime_get_coarse_ts64(struct timespec64 *ts);
46extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
47
48void getboottime64(struct timespec64 *ts);
49
50/*
51 * time64_t base interfaces
52 */
53extern time64_t ktime_get_seconds(void);
54extern time64_t __ktime_get_real_seconds(void);
55extern time64_t ktime_get_real_seconds(void);
56
57/*
58 * ktime_t based interfaces
59 */
60
61enum tk_offsets {
62 TK_OFFS_REAL,
63 TK_OFFS_BOOT,
64 TK_OFFS_TAI,
65 TK_OFFS_MAX,
66};
67
68extern ktime_t ktime_get(void);
69extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
70extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
71extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
72extern ktime_t ktime_get_raw(void);
73extern 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 */
80static inline ktime_t ktime_get_real(void)
81{
82 return ktime_get_with_offset(offs: TK_OFFS_REAL);
83}
84
85static inline ktime_t ktime_get_coarse_real(void)
86{
87 return ktime_get_coarse_with_offset(offs: 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 */
98static inline ktime_t ktime_get_boottime(void)
99{
100 return ktime_get_with_offset(offs: TK_OFFS_BOOT);
101}
102
103static inline ktime_t ktime_get_coarse_boottime(void)
104{
105 return ktime_get_coarse_with_offset(offs: 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 */
113static inline ktime_t ktime_get_clocktai(void)
114{
115 return ktime_get_with_offset(offs: TK_OFFS_TAI);
116}
117
118static inline ktime_t ktime_get_coarse_clocktai(void)
119{
120 return ktime_get_coarse_with_offset(offs: TK_OFFS_TAI);
121}
122
123static inline ktime_t ktime_get_coarse(void)
124{
125 struct timespec64 ts;
126
127 ktime_get_coarse_ts64(ts: &ts);
128 return timespec64_to_ktime(ts);
129}
130
131static inline u64 ktime_get_coarse_ns(void)
132{
133 return ktime_to_ns(kt: ktime_get_coarse());
134}
135
136static inline u64 ktime_get_coarse_real_ns(void)
137{
138 return ktime_to_ns(kt: ktime_get_coarse_real());
139}
140
141static inline u64 ktime_get_coarse_boottime_ns(void)
142{
143 return ktime_to_ns(kt: ktime_get_coarse_boottime());
144}
145
146static inline u64 ktime_get_coarse_clocktai_ns(void)
147{
148 return ktime_to_ns(kt: 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 */
157static inline ktime_t ktime_mono_to_real(ktime_t mono)
158{
159 return ktime_mono_to_any(tmono: mono, offs: 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 */
167static inline u64 ktime_get_ns(void)
168{
169 return ktime_to_ns(kt: 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 */
177static inline u64 ktime_get_real_ns(void)
178{
179 return ktime_to_ns(kt: 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 */
187static inline u64 ktime_get_boottime_ns(void)
188{
189 return ktime_to_ns(kt: 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 */
197static inline u64 ktime_get_clocktai_ns(void)
198{
199 return ktime_to_ns(kt: 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 */
207static inline u64 ktime_get_raw_ns(void)
208{
209 return ktime_to_ns(kt: ktime_get_raw());
210}
211
212extern u64 ktime_get_mono_fast_ns(void);
213extern u64 ktime_get_raw_fast_ns(void);
214extern u64 ktime_get_boot_fast_ns(void);
215extern u64 ktime_get_tai_fast_ns(void);
216extern 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 */
223static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
224{
225 *ts = ktime_to_timespec64(ktime_get_boottime());
226}
227
228static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
229{
230 *ts = ktime_to_timespec64(ktime_get_coarse_boottime());
231}
232
233static inline time64_t ktime_get_boottime_seconds(void)
234{
235 return ktime_divns(kt: ktime_get_coarse_boottime(), NSEC_PER_SEC);
236}
237
238static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
239{
240 *ts = ktime_to_timespec64(ktime_get_clocktai());
241}
242
243static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
244{
245 *ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
246}
247
248static inline time64_t ktime_get_clocktai_seconds(void)
249{
250 return ktime_divns(kt: ktime_get_coarse_clocktai(), NSEC_PER_SEC);
251}
252
253/*
254 * RTC specific
255 */
256extern bool timekeeping_rtc_skipsuspend(void);
257extern bool timekeeping_rtc_skipresume(void);
258
259extern 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 */
267struct 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 */
283struct 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 */
299struct 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 */
314struct system_counterval_t {
315 u64 cycles;
316 enum clocksource_ids cs_id;
317};
318
319/*
320 * Get cross timestamp between system clock and device clock
321 */
322extern int get_device_system_crosststamp(
323 int (*get_time_fn)(ktime_t *device_time,
324 struct system_counterval_t *system_counterval,
325 void *ctx),
326 void *ctx,
327 struct system_time_snapshot *history,
328 struct system_device_crosststamp *xtstamp);
329
330/*
331 * Simultaneously snapshot realtime and monotonic raw clocks
332 */
333extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
334
335/* NMI safe mono/boot/realtime timestamps */
336extern void ktime_get_fast_timestamps(struct ktime_timestamps *snap);
337
338/*
339 * Persistent clock related interfaces
340 */
341extern int persistent_clock_is_local;
342
343extern void read_persistent_clock64(struct timespec64 *ts);
344void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
345 struct timespec64 *boot_offset);
346#ifdef CONFIG_GENERIC_CMOS_UPDATE
347extern int update_persistent_clock64(struct timespec64 now);
348#endif
349
350#endif
351

source code of linux/include/linux/timekeeping.h