timekeeping.h

  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);
 47extern void ktime_get_clock_ts64(clockid_t id, struct timespec64 *ts);
 48
 49/* Multigrain timestamp interfaces */
 50extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts);
 51extern void ktime_get_real_ts64_mg(struct timespec64 *ts);
 52extern unsigned long timekeeping_get_mg_floor_swaps(void);
 53
 54void getboottime64(struct timespec64 *ts);
 55
 56/*
 57 * time64_t base interfaces
 58 */
 59extern time64_t ktime_get_seconds(void);
 60extern time64_t __ktime_get_real_seconds(void);
 61extern time64_t ktime_get_real_seconds(void);
 62
 63/*
 64 * ktime_t based interfaces
 65 */
 66
 67enum tk_offsets {
 68	TK_OFFS_REAL,
 69	TK_OFFS_BOOT,
 70	TK_OFFS_TAI,
 71	TK_OFFS_MAX,
 72};
 73
 74extern ktime_t ktime_get(void);
 75extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
 76extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
 77extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
 78extern ktime_t ktime_get_raw(void);
 79extern 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 */
 86static inline ktime_t ktime_get_real(void)
 87{
 88	return ktime_get_with_offset(TK_OFFS_REAL);
 89}
 90
 91static 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 */
104static inline ktime_t ktime_get_boottime(void)
105{
106	return ktime_get_with_offset(TK_OFFS_BOOT);
107}
108
109static 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 */
119static inline ktime_t ktime_get_clocktai(void)
120{
121	return ktime_get_with_offset(TK_OFFS_TAI);
122}
123
124static inline ktime_t ktime_get_coarse_clocktai(void)
125{
126	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
127}
128
129static 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
137static inline u64 ktime_get_coarse_ns(void)
138{
139	return ktime_to_ns(ktime_get_coarse());
140}
141
142static inline u64 ktime_get_coarse_real_ns(void)
143{
144	return ktime_to_ns(ktime_get_coarse_real());
145}
146
147static inline u64 ktime_get_coarse_boottime_ns(void)
148{
149	return ktime_to_ns(ktime_get_coarse_boottime());
150}
151
152static 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 */
163static 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 */
173static 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 */
183static 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 */
193static 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 */
203static 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 */
213static inline u64 ktime_get_raw_ns(void)
214{
215	return ktime_to_ns(ktime_get_raw());
216}
217
218extern u64 ktime_get_mono_fast_ns(void);
219extern u64 ktime_get_raw_fast_ns(void);
220extern u64 ktime_get_boot_fast_ns(void);
221extern u64 ktime_get_tai_fast_ns(void);
222extern 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 */
229static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
230{
231	*ts = ktime_to_timespec64(ktime_get_boottime());
232}
233
234static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
235{
236	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
237}
238
239static inline time64_t ktime_get_boottime_seconds(void)
240{
241	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
242}
243
244static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
245{
246	*ts = ktime_to_timespec64(ktime_get_clocktai());
247}
248
249static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
250{
251	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
252}
253
254static 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 */
262extern bool timekeeping_rtc_skipsuspend(void);
263extern bool timekeeping_rtc_skipresume(void);
264
265extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
266
267/*
268 * Auxiliary clock interfaces
269 */
270#ifdef CONFIG_POSIX_AUX_CLOCKS
271extern bool ktime_get_aux(clockid_t id, ktime_t *kt);
272extern bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt);
273#else
274static inline bool ktime_get_aux(clockid_t id, ktime_t *kt) { return false; }
275static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { return false; }
276#endif
277
278/**
279 * struct system_time_snapshot - simultaneous raw/real time capture with
280 *				 counter value
281 * @cycles:	Clocksource counter value to produce the system times
282 * @real:	Realtime system time
283 * @boot:	Boot time
284 * @raw:	Monotonic raw system time
285 * @cs_id:	Clocksource ID
286 * @clock_was_set_seq:	The sequence number of clock-was-set events
287 * @cs_was_changed_seq:	The sequence number of clocksource change events
288 */
289struct system_time_snapshot {
290	u64			cycles;
291	ktime_t			real;
292	ktime_t			boot;
293	ktime_t			raw;
294	enum clocksource_ids	cs_id;
295	unsigned int		clock_was_set_seq;
296	u8			cs_was_changed_seq;
297};
298
299/**
300 * struct system_device_crosststamp - system/device cross-timestamp
301 *				      (synchronized capture)
302 * @device:		Device time
303 * @sys_realtime:	Realtime simultaneous with device time
304 * @sys_monoraw:	Monotonic raw simultaneous with device time
305 */
306struct system_device_crosststamp {
307	ktime_t device;
308	ktime_t sys_realtime;
309	ktime_t sys_monoraw;
310};
311
312/**
313 * struct system_counterval_t - system counter value with the ID of the
314 *				corresponding clocksource
315 * @cycles:	System counter value
316 * @cs_id:	Clocksource ID corresponding to system counter value. Used by
317 *		timekeeping code to verify comparability of two cycle values.
318 *		The default ID, CSID_GENERIC, does not identify a specific
319 *		clocksource.
320 * @use_nsecs:	@cycles is in nanoseconds.
321 */
322struct system_counterval_t {
323	u64			cycles;
324	enum clocksource_ids	cs_id;
325	bool			use_nsecs;
326};
327
328extern bool ktime_real_to_base_clock(ktime_t treal,
329				     enum clocksource_ids base_id, u64 *cycles);
330extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);
331
332/*
333 * Get cross timestamp between system clock and device clock
334 */
335extern int get_device_system_crosststamp(
336			int (*get_time_fn)(ktime_t *device_time,
337				struct system_counterval_t *system_counterval,
338				void *ctx),
339			void *ctx,
340			struct system_time_snapshot *history,
341			struct system_device_crosststamp *xtstamp);
342
343/*
344 * Simultaneously snapshot realtime and monotonic raw clocks
345 */
346extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
347
348/*
349 * Persistent clock related interfaces
350 */
351extern int persistent_clock_is_local;
352
353extern void read_persistent_clock64(struct timespec64 *ts);
354void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
355					  struct timespec64 *boot_offset);
356#ifdef CONFIG_GENERIC_CMOS_UPDATE
357extern int update_persistent_clock64(struct timespec64 now);
358#endif
359
360#endif