2 * linux/kernel/time/timekeeping.c
4 * Kernel timekeeping code and accessor functions
6 * This code was moved from linux/kernel/timer.c.
7 * Please see that file for copyright and history logs.
11 #include <linux/timekeeper_internal.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/percpu.h>
15 #include <linux/init.h>
17 #include <linux/sched.h>
18 #include <linux/syscore_ops.h>
19 #include <linux/clocksource.h>
20 #include <linux/jiffies.h>
21 #include <linux/time.h>
22 #include <linux/tick.h>
23 #include <linux/stop_machine.h>
24 #include <linux/pvclock_gtod.h>
25 #include <linux/compiler.h>
27 #include "tick-internal.h"
28 #include "ntp_internal.h"
29 #include "timekeeping_internal.h"
31 #define TK_CLEAR_NTP (1 << 0)
32 #define TK_MIRROR (1 << 1)
33 #define TK_CLOCK_WAS_SET (1 << 2)
36 * The most important data for readout fits into a single 64 byte
41 struct timekeeper timekeeper;
42 } tk_core ____cacheline_aligned;
44 static DEFINE_RAW_SPINLOCK(timekeeper_lock);
45 static struct timekeeper shadow_timekeeper;
47 /* flag for if timekeeping is suspended */
48 int __read_mostly timekeeping_suspended;
50 /* Flag for if there is a persistent clock on this platform */
51 bool __read_mostly persistent_clock_exist = false;
53 static inline void tk_normalize_xtime(struct timekeeper *tk)
55 while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
56 tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift;
61 static inline struct timespec64 tk_xtime(struct timekeeper *tk)
65 ts.tv_sec = tk->xtime_sec;
66 ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
70 static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts)
72 tk->xtime_sec = ts->tv_sec;
73 tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
76 static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts)
78 tk->xtime_sec += ts->tv_sec;
79 tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
80 tk_normalize_xtime(tk);
83 static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
85 struct timespec64 tmp;
88 * Verify consistency of: offset_real = -wall_to_monotonic
89 * before modifying anything
91 set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec,
92 -tk->wall_to_monotonic.tv_nsec);
93 WARN_ON_ONCE(tk->offs_real.tv64 != timespec64_to_ktime(tmp).tv64);
94 tk->wall_to_monotonic = wtm;
95 set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
96 tk->offs_real = timespec64_to_ktime(tmp);
97 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
100 static void tk_set_sleep_time(struct timekeeper *tk, struct timespec64 t)
102 /* Verify consistency before modifying */
103 WARN_ON_ONCE(tk->offs_boot.tv64 != timespec64_to_ktime(tk->total_sleep_time).tv64);
105 tk->total_sleep_time = t;
106 tk->offs_boot = timespec64_to_ktime(t);
110 * tk_setup_internals - Set up internals to use clocksource clock.
112 * @tk: The target timekeeper to setup.
113 * @clock: Pointer to clocksource.
115 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
116 * pair and interval request.
118 * Unless you're the timekeeping code, you should not be using this!
120 static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
123 u64 tmp, ntpinterval;
124 struct clocksource *old_clock;
126 old_clock = tk->clock;
128 tk->cycle_last = clock->cycle_last = clock->read(clock);
130 /* Do the ns -> cycle conversion first, using original mult */
131 tmp = NTP_INTERVAL_LENGTH;
132 tmp <<= clock->shift;
134 tmp += clock->mult/2;
135 do_div(tmp, clock->mult);
139 interval = (cycle_t) tmp;
140 tk->cycle_interval = interval;
142 /* Go back from cycles -> shifted ns */
143 tk->xtime_interval = (u64) interval * clock->mult;
144 tk->xtime_remainder = ntpinterval - tk->xtime_interval;
146 ((u64) interval * clock->mult) >> clock->shift;
148 /* if changing clocks, convert xtime_nsec shift units */
150 int shift_change = clock->shift - old_clock->shift;
151 if (shift_change < 0)
152 tk->xtime_nsec >>= -shift_change;
154 tk->xtime_nsec <<= shift_change;
156 tk->shift = clock->shift;
159 tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
162 * The timekeeper keeps its own mult values for the currently
163 * active clocksource. These value will be adjusted via NTP
164 * to counteract clock drifting.
166 tk->mult = clock->mult;
169 /* Timekeeper helper functions. */
171 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
172 static u32 default_arch_gettimeoffset(void) { return 0; }
173 u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
175 static inline u32 arch_gettimeoffset(void) { return 0; }
178 static inline s64 timekeeping_get_ns(struct timekeeper *tk)
180 cycle_t cycle_now, cycle_delta;
181 struct clocksource *clock;
184 /* read clocksource: */
186 cycle_now = clock->read(clock);
188 /* calculate the delta since the last update_wall_time: */
189 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
191 nsec = cycle_delta * tk->mult + tk->xtime_nsec;
194 /* If arch requires, add in get_arch_timeoffset() */
195 return nsec + arch_gettimeoffset();
198 static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
200 cycle_t cycle_now, cycle_delta;
201 struct clocksource *clock;
204 /* read clocksource: */
206 cycle_now = clock->read(clock);
208 /* calculate the delta since the last update_wall_time: */
209 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
211 /* convert delta to nanoseconds. */
212 nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
214 /* If arch requires, add in get_arch_timeoffset() */
215 return nsec + arch_gettimeoffset();
218 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
220 static inline void update_vsyscall(struct timekeeper *tk)
225 update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
228 static inline void old_vsyscall_fixup(struct timekeeper *tk)
233 * Store only full nanoseconds into xtime_nsec after rounding
234 * it up and add the remainder to the error difference.
235 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
236 * by truncating the remainder in vsyscalls. However, it causes
237 * additional work to be done in timekeeping_adjust(). Once
238 * the vsyscall implementations are converted to use xtime_nsec
239 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
240 * users are removed, this can be killed.
242 remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
243 tk->xtime_nsec -= remainder;
244 tk->xtime_nsec += 1ULL << tk->shift;
245 tk->ntp_error += remainder << tk->ntp_error_shift;
246 tk->ntp_error -= (1ULL << tk->shift) << tk->ntp_error_shift;
249 #define old_vsyscall_fixup(tk)
252 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
254 static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
256 raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk);
260 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
262 int pvclock_gtod_register_notifier(struct notifier_block *nb)
264 struct timekeeper *tk = &tk_core.timekeeper;
268 raw_spin_lock_irqsave(&timekeeper_lock, flags);
269 ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
270 update_pvclock_gtod(tk, true);
271 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
275 EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
278 * pvclock_gtod_unregister_notifier - unregister a pvclock
279 * timedata update listener
281 int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
286 raw_spin_lock_irqsave(&timekeeper_lock, flags);
287 ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
288 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
292 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
295 * Update the ktime_t based scalar nsec members of the timekeeper
297 static inline void tk_update_ktime_data(struct timekeeper *tk)
302 * The xtime based monotonic readout is:
303 * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now();
304 * The ktime based monotonic readout is:
305 * nsec = base_mono + now();
306 * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec
308 nsec = (s64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
309 nsec *= NSEC_PER_SEC;
310 nsec += tk->wall_to_monotonic.tv_nsec;
311 tk->base_mono = ns_to_ktime(nsec);
314 /* must hold timekeeper_lock */
315 static void timekeeping_update(struct timekeeper *tk, unsigned int action)
317 if (action & TK_CLEAR_NTP) {
322 update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
324 tk_update_ktime_data(tk);
326 if (action & TK_MIRROR)
327 memcpy(&shadow_timekeeper, &tk_core.timekeeper,
328 sizeof(tk_core.timekeeper));
332 * timekeeping_forward_now - update clock to the current time
334 * Forward the current clock to update its state since the last call to
335 * update_wall_time(). This is useful before significant clock changes,
336 * as it avoids having to deal with this time offset explicitly.
338 static void timekeeping_forward_now(struct timekeeper *tk)
340 cycle_t cycle_now, cycle_delta;
341 struct clocksource *clock;
345 cycle_now = clock->read(clock);
346 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
347 tk->cycle_last = clock->cycle_last = cycle_now;
349 tk->xtime_nsec += cycle_delta * tk->mult;
351 /* If arch requires, add in get_arch_timeoffset() */
352 tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
354 tk_normalize_xtime(tk);
356 nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
357 timespec64_add_ns(&tk->raw_time, nsec);
361 * __getnstimeofday64 - Returns the time of day in a timespec64.
362 * @ts: pointer to the timespec to be set
364 * Updates the time of day in the timespec.
365 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
367 int __getnstimeofday64(struct timespec64 *ts)
369 struct timekeeper *tk = &tk_core.timekeeper;
374 seq = read_seqcount_begin(&tk_core.seq);
376 ts->tv_sec = tk->xtime_sec;
377 nsecs = timekeeping_get_ns(tk);
379 } while (read_seqcount_retry(&tk_core.seq, seq));
382 timespec64_add_ns(ts, nsecs);
385 * Do not bail out early, in case there were callers still using
386 * the value, even in the face of the WARN_ON.
388 if (unlikely(timekeeping_suspended))
392 EXPORT_SYMBOL(__getnstimeofday64);
395 * getnstimeofday64 - Returns the time of day in a timespec64.
396 * @ts: pointer to the timespec to be set
398 * Returns the time of day in a timespec (WARN if suspended).
400 void getnstimeofday64(struct timespec64 *ts)
402 WARN_ON(__getnstimeofday64(ts));
404 EXPORT_SYMBOL(getnstimeofday64);
406 ktime_t ktime_get(void)
408 struct timekeeper *tk = &tk_core.timekeeper;
413 WARN_ON(timekeeping_suspended);
416 seq = read_seqcount_begin(&tk_core.seq);
417 base = tk->base_mono;
418 nsecs = timekeeping_get_ns(tk);
420 } while (read_seqcount_retry(&tk_core.seq, seq));
422 return ktime_add_ns(base, nsecs);
424 EXPORT_SYMBOL_GPL(ktime_get);
426 static ktime_t *offsets[TK_OFFS_MAX] = {
427 [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
428 [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
429 [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
432 ktime_t ktime_get_with_offset(enum tk_offsets offs)
434 struct timekeeper *tk = &tk_core.timekeeper;
436 ktime_t base, *offset = offsets[offs];
439 WARN_ON(timekeeping_suspended);
442 seq = read_seqcount_begin(&tk_core.seq);
443 base = ktime_add(tk->base_mono, *offset);
444 nsecs = timekeeping_get_ns(tk);
446 } while (read_seqcount_retry(&tk_core.seq, seq));
448 return ktime_add_ns(base, nsecs);
451 EXPORT_SYMBOL_GPL(ktime_get_with_offset);
454 * ktime_mono_to_any() - convert mononotic time to any other time
455 * @tmono: time to convert.
456 * @offs: which offset to use
458 ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
460 ktime_t *offset = offsets[offs];
465 seq = read_seqcount_begin(&tk_core.seq);
466 tconv = ktime_add(tmono, *offset);
467 } while (read_seqcount_retry(&tk_core.seq, seq));
471 EXPORT_SYMBOL_GPL(ktime_mono_to_any);
474 * ktime_get_ts64 - get the monotonic clock in timespec64 format
475 * @ts: pointer to timespec variable
477 * The function calculates the monotonic clock from the realtime
478 * clock and the wall_to_monotonic offset and stores the result
479 * in normalized timespec format in the variable pointed to by @ts.
481 void ktime_get_ts64(struct timespec64 *ts)
483 struct timekeeper *tk = &tk_core.timekeeper;
484 struct timespec64 tomono;
488 WARN_ON(timekeeping_suspended);
491 seq = read_seqcount_begin(&tk_core.seq);
492 ts->tv_sec = tk->xtime_sec;
493 nsec = timekeeping_get_ns(tk);
494 tomono = tk->wall_to_monotonic;
496 } while (read_seqcount_retry(&tk_core.seq, seq));
498 ts->tv_sec += tomono.tv_sec;
500 timespec64_add_ns(ts, nsec + tomono.tv_nsec);
502 EXPORT_SYMBOL_GPL(ktime_get_ts64);
506 * timekeeping_clocktai - Returns the TAI time of day in a timespec
507 * @ts: pointer to the timespec to be set
509 * Returns the time of day in a timespec.
511 void timekeeping_clocktai(struct timespec *ts)
513 struct timekeeper *tk = &tk_core.timekeeper;
514 struct timespec64 ts64;
518 WARN_ON(timekeeping_suspended);
521 seq = read_seqcount_begin(&tk_core.seq);
523 ts64.tv_sec = tk->xtime_sec + tk->tai_offset;
524 nsecs = timekeeping_get_ns(tk);
526 } while (read_seqcount_retry(&tk_core.seq, seq));
529 timespec64_add_ns(&ts64, nsecs);
530 *ts = timespec64_to_timespec(ts64);
533 EXPORT_SYMBOL(timekeeping_clocktai);
535 #ifdef CONFIG_NTP_PPS
538 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
539 * @ts_raw: pointer to the timespec to be set to raw monotonic time
540 * @ts_real: pointer to the timespec to be set to the time of day
542 * This function reads both the time of day and raw monotonic time at the
543 * same time atomically and stores the resulting timestamps in timespec
546 void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
548 struct timekeeper *tk = &tk_core.timekeeper;
550 s64 nsecs_raw, nsecs_real;
552 WARN_ON_ONCE(timekeeping_suspended);
555 seq = read_seqcount_begin(&tk_core.seq);
557 *ts_raw = timespec64_to_timespec(tk->raw_time);
558 ts_real->tv_sec = tk->xtime_sec;
559 ts_real->tv_nsec = 0;
561 nsecs_raw = timekeeping_get_ns_raw(tk);
562 nsecs_real = timekeeping_get_ns(tk);
564 } while (read_seqcount_retry(&tk_core.seq, seq));
566 timespec_add_ns(ts_raw, nsecs_raw);
567 timespec_add_ns(ts_real, nsecs_real);
569 EXPORT_SYMBOL(getnstime_raw_and_real);
571 #endif /* CONFIG_NTP_PPS */
574 * do_gettimeofday - Returns the time of day in a timeval
575 * @tv: pointer to the timeval to be set
577 * NOTE: Users should be converted to using getnstimeofday()
579 void do_gettimeofday(struct timeval *tv)
581 struct timespec64 now;
583 getnstimeofday64(&now);
584 tv->tv_sec = now.tv_sec;
585 tv->tv_usec = now.tv_nsec/1000;
587 EXPORT_SYMBOL(do_gettimeofday);
590 * do_settimeofday - Sets the time of day
591 * @tv: pointer to the timespec variable containing the new time
593 * Sets the time of day to the new time and update NTP and notify hrtimers
595 int do_settimeofday(const struct timespec *tv)
597 struct timekeeper *tk = &tk_core.timekeeper;
598 struct timespec64 ts_delta, xt, tmp;
601 if (!timespec_valid_strict(tv))
604 raw_spin_lock_irqsave(&timekeeper_lock, flags);
605 write_seqcount_begin(&tk_core.seq);
607 timekeeping_forward_now(tk);
610 ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
611 ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
613 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta));
615 tmp = timespec_to_timespec64(*tv);
616 tk_set_xtime(tk, &tmp);
618 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
620 write_seqcount_end(&tk_core.seq);
621 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
623 /* signal hrtimers about time change */
628 EXPORT_SYMBOL(do_settimeofday);
631 * timekeeping_inject_offset - Adds or subtracts from the current time.
632 * @tv: pointer to the timespec variable containing the offset
634 * Adds or subtracts an offset value from the current time.
636 int timekeeping_inject_offset(struct timespec *ts)
638 struct timekeeper *tk = &tk_core.timekeeper;
640 struct timespec64 ts64, tmp;
643 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
646 ts64 = timespec_to_timespec64(*ts);
648 raw_spin_lock_irqsave(&timekeeper_lock, flags);
649 write_seqcount_begin(&tk_core.seq);
651 timekeeping_forward_now(tk);
653 /* Make sure the proposed value is valid */
654 tmp = timespec64_add(tk_xtime(tk), ts64);
655 if (!timespec64_valid_strict(&tmp)) {
660 tk_xtime_add(tk, &ts64);
661 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64));
663 error: /* even if we error out, we forwarded the time, so call update */
664 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
666 write_seqcount_end(&tk_core.seq);
667 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
669 /* signal hrtimers about time change */
674 EXPORT_SYMBOL(timekeeping_inject_offset);
678 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
681 s32 timekeeping_get_tai_offset(void)
683 struct timekeeper *tk = &tk_core.timekeeper;
688 seq = read_seqcount_begin(&tk_core.seq);
689 ret = tk->tai_offset;
690 } while (read_seqcount_retry(&tk_core.seq, seq));
696 * __timekeeping_set_tai_offset - Lock free worker function
699 static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
701 tk->tai_offset = tai_offset;
702 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
706 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
709 void timekeeping_set_tai_offset(s32 tai_offset)
711 struct timekeeper *tk = &tk_core.timekeeper;
714 raw_spin_lock_irqsave(&timekeeper_lock, flags);
715 write_seqcount_begin(&tk_core.seq);
716 __timekeeping_set_tai_offset(tk, tai_offset);
717 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
718 write_seqcount_end(&tk_core.seq);
719 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
724 * change_clocksource - Swaps clocksources if a new one is available
726 * Accumulates current time interval and initializes new clocksource
728 static int change_clocksource(void *data)
730 struct timekeeper *tk = &tk_core.timekeeper;
731 struct clocksource *new, *old;
734 new = (struct clocksource *) data;
736 raw_spin_lock_irqsave(&timekeeper_lock, flags);
737 write_seqcount_begin(&tk_core.seq);
739 timekeeping_forward_now(tk);
741 * If the cs is in module, get a module reference. Succeeds
742 * for built-in code (owner == NULL) as well.
744 if (try_module_get(new->owner)) {
745 if (!new->enable || new->enable(new) == 0) {
747 tk_setup_internals(tk, new);
750 module_put(old->owner);
752 module_put(new->owner);
755 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
757 write_seqcount_end(&tk_core.seq);
758 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
764 * timekeeping_notify - Install a new clock source
765 * @clock: pointer to the clock source
767 * This function is called from clocksource.c after a new, better clock
768 * source has been registered. The caller holds the clocksource_mutex.
770 int timekeeping_notify(struct clocksource *clock)
772 struct timekeeper *tk = &tk_core.timekeeper;
774 if (tk->clock == clock)
776 stop_machine(change_clocksource, clock, NULL);
778 return tk->clock == clock ? 0 : -1;
782 * getrawmonotonic - Returns the raw monotonic time in a timespec
783 * @ts: pointer to the timespec to be set
785 * Returns the raw monotonic time (completely un-modified by ntp)
787 void getrawmonotonic(struct timespec *ts)
789 struct timekeeper *tk = &tk_core.timekeeper;
790 struct timespec64 ts64;
795 seq = read_seqcount_begin(&tk_core.seq);
796 nsecs = timekeeping_get_ns_raw(tk);
799 } while (read_seqcount_retry(&tk_core.seq, seq));
801 timespec64_add_ns(&ts64, nsecs);
802 *ts = timespec64_to_timespec(ts64);
804 EXPORT_SYMBOL(getrawmonotonic);
807 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
809 int timekeeping_valid_for_hres(void)
811 struct timekeeper *tk = &tk_core.timekeeper;
816 seq = read_seqcount_begin(&tk_core.seq);
818 ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
820 } while (read_seqcount_retry(&tk_core.seq, seq));
826 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
828 u64 timekeeping_max_deferment(void)
830 struct timekeeper *tk = &tk_core.timekeeper;
835 seq = read_seqcount_begin(&tk_core.seq);
837 ret = tk->clock->max_idle_ns;
839 } while (read_seqcount_retry(&tk_core.seq, seq));
845 * read_persistent_clock - Return time from the persistent clock.
847 * Weak dummy function for arches that do not yet support it.
848 * Reads the time from the battery backed persistent clock.
849 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
851 * XXX - Do be sure to remove it once all arches implement it.
853 void __weak read_persistent_clock(struct timespec *ts)
860 * read_boot_clock - Return time of the system start.
862 * Weak dummy function for arches that do not yet support it.
863 * Function to read the exact time the system has been started.
864 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
866 * XXX - Do be sure to remove it once all arches implement it.
868 void __weak read_boot_clock(struct timespec *ts)
875 * timekeeping_init - Initializes the clocksource and common timekeeping values
877 void __init timekeeping_init(void)
879 struct timekeeper *tk = &tk_core.timekeeper;
880 struct clocksource *clock;
882 struct timespec64 now, boot, tmp;
885 read_persistent_clock(&ts);
886 now = timespec_to_timespec64(ts);
887 if (!timespec64_valid_strict(&now)) {
888 pr_warn("WARNING: Persistent clock returned invalid value!\n"
889 " Check your CMOS/BIOS settings.\n");
892 } else if (now.tv_sec || now.tv_nsec)
893 persistent_clock_exist = true;
895 read_boot_clock(&ts);
896 boot = timespec_to_timespec64(ts);
897 if (!timespec64_valid_strict(&boot)) {
898 pr_warn("WARNING: Boot clock returned invalid value!\n"
899 " Check your CMOS/BIOS settings.\n");
904 raw_spin_lock_irqsave(&timekeeper_lock, flags);
905 write_seqcount_begin(&tk_core.seq);
908 clock = clocksource_default_clock();
910 clock->enable(clock);
911 tk_setup_internals(tk, clock);
913 tk_set_xtime(tk, &now);
914 tk->raw_time.tv_sec = 0;
915 tk->raw_time.tv_nsec = 0;
916 if (boot.tv_sec == 0 && boot.tv_nsec == 0)
919 set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec);
920 tk_set_wall_to_mono(tk, tmp);
924 tk_set_sleep_time(tk, tmp);
926 timekeeping_update(tk, TK_MIRROR);
928 write_seqcount_end(&tk_core.seq);
929 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
932 /* time in seconds when suspend began */
933 static struct timespec64 timekeeping_suspend_time;
936 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
937 * @delta: pointer to a timespec delta value
939 * Takes a timespec offset measuring a suspend interval and properly
940 * adds the sleep offset to the timekeeping variables.
942 static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
943 struct timespec64 *delta)
945 if (!timespec64_valid_strict(delta)) {
946 printk_deferred(KERN_WARNING
947 "__timekeeping_inject_sleeptime: Invalid "
948 "sleep delta value!\n");
951 tk_xtime_add(tk, delta);
952 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
953 tk_set_sleep_time(tk, timespec64_add(tk->total_sleep_time, *delta));
954 tk_debug_account_sleep_time(delta);
958 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
959 * @delta: pointer to a timespec delta value
961 * This hook is for architectures that cannot support read_persistent_clock
962 * because their RTC/persistent clock is only accessible when irqs are enabled.
964 * This function should only be called by rtc_resume(), and allows
965 * a suspend offset to be injected into the timekeeping values.
967 void timekeeping_inject_sleeptime(struct timespec *delta)
969 struct timekeeper *tk = &tk_core.timekeeper;
970 struct timespec64 tmp;
974 * Make sure we don't set the clock twice, as timekeeping_resume()
977 if (has_persistent_clock())
980 raw_spin_lock_irqsave(&timekeeper_lock, flags);
981 write_seqcount_begin(&tk_core.seq);
983 timekeeping_forward_now(tk);
985 tmp = timespec_to_timespec64(*delta);
986 __timekeeping_inject_sleeptime(tk, &tmp);
988 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
990 write_seqcount_end(&tk_core.seq);
991 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
993 /* signal hrtimers about time change */
998 * timekeeping_resume - Resumes the generic timekeeping subsystem.
1000 * This is for the generic clocksource timekeeping.
1001 * xtime/wall_to_monotonic/jiffies/etc are
1002 * still managed by arch specific suspend/resume code.
1004 static void timekeeping_resume(void)
1006 struct timekeeper *tk = &tk_core.timekeeper;
1007 struct clocksource *clock = tk->clock;
1008 unsigned long flags;
1009 struct timespec64 ts_new, ts_delta;
1010 struct timespec tmp;
1011 cycle_t cycle_now, cycle_delta;
1012 bool suspendtime_found = false;
1014 read_persistent_clock(&tmp);
1015 ts_new = timespec_to_timespec64(tmp);
1017 clockevents_resume();
1018 clocksource_resume();
1020 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1021 write_seqcount_begin(&tk_core.seq);
1024 * After system resumes, we need to calculate the suspended time and
1025 * compensate it for the OS time. There are 3 sources that could be
1026 * used: Nonstop clocksource during suspend, persistent clock and rtc
1029 * One specific platform may have 1 or 2 or all of them, and the
1030 * preference will be:
1031 * suspend-nonstop clocksource -> persistent clock -> rtc
1032 * The less preferred source will only be tried if there is no better
1033 * usable source. The rtc part is handled separately in rtc core code.
1035 cycle_now = clock->read(clock);
1036 if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
1037 cycle_now > clock->cycle_last) {
1038 u64 num, max = ULLONG_MAX;
1039 u32 mult = clock->mult;
1040 u32 shift = clock->shift;
1043 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
1046 * "cycle_delta * mutl" may cause 64 bits overflow, if the
1047 * suspended time is too long. In that case we need do the
1048 * 64 bits math carefully
1051 if (cycle_delta > max) {
1052 num = div64_u64(cycle_delta, max);
1053 nsec = (((u64) max * mult) >> shift) * num;
1054 cycle_delta -= num * max;
1056 nsec += ((u64) cycle_delta * mult) >> shift;
1058 ts_delta = ns_to_timespec64(nsec);
1059 suspendtime_found = true;
1060 } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
1061 ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time);
1062 suspendtime_found = true;
1065 if (suspendtime_found)
1066 __timekeeping_inject_sleeptime(tk, &ts_delta);
1068 /* Re-base the last cycle value */
1069 tk->cycle_last = clock->cycle_last = cycle_now;
1071 timekeeping_suspended = 0;
1072 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1073 write_seqcount_end(&tk_core.seq);
1074 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1076 touch_softlockup_watchdog();
1078 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
1080 /* Resume hrtimers */
1084 static int timekeeping_suspend(void)
1086 struct timekeeper *tk = &tk_core.timekeeper;
1087 unsigned long flags;
1088 struct timespec64 delta, delta_delta;
1089 static struct timespec64 old_delta;
1090 struct timespec tmp;
1092 read_persistent_clock(&tmp);
1093 timekeeping_suspend_time = timespec_to_timespec64(tmp);
1096 * On some systems the persistent_clock can not be detected at
1097 * timekeeping_init by its return value, so if we see a valid
1098 * value returned, update the persistent_clock_exists flag.
1100 if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec)
1101 persistent_clock_exist = true;
1103 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1104 write_seqcount_begin(&tk_core.seq);
1105 timekeeping_forward_now(tk);
1106 timekeeping_suspended = 1;
1109 * To avoid drift caused by repeated suspend/resumes,
1110 * which each can add ~1 second drift error,
1111 * try to compensate so the difference in system time
1112 * and persistent_clock time stays close to constant.
1114 delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time);
1115 delta_delta = timespec64_sub(delta, old_delta);
1116 if (abs(delta_delta.tv_sec) >= 2) {
1118 * if delta_delta is too large, assume time correction
1119 * has occured and set old_delta to the current delta.
1123 /* Otherwise try to adjust old_system to compensate */
1124 timekeeping_suspend_time =
1125 timespec64_add(timekeeping_suspend_time, delta_delta);
1128 timekeeping_update(tk, TK_MIRROR);
1129 write_seqcount_end(&tk_core.seq);
1130 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1132 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
1133 clocksource_suspend();
1134 clockevents_suspend();
1139 /* sysfs resume/suspend bits for timekeeping */
1140 static struct syscore_ops timekeeping_syscore_ops = {
1141 .resume = timekeeping_resume,
1142 .suspend = timekeeping_suspend,
1145 static int __init timekeeping_init_ops(void)
1147 register_syscore_ops(&timekeeping_syscore_ops);
1151 device_initcall(timekeeping_init_ops);
1154 * If the error is already larger, we look ahead even further
1155 * to compensate for late or lost adjustments.
1157 static __always_inline int timekeeping_bigadjust(struct timekeeper *tk,
1158 s64 error, s64 *interval,
1162 u32 look_ahead, adj;
1166 * Use the current error value to determine how much to look ahead.
1167 * The larger the error the slower we adjust for it to avoid problems
1168 * with losing too many ticks, otherwise we would overadjust and
1169 * produce an even larger error. The smaller the adjustment the
1170 * faster we try to adjust for it, as lost ticks can do less harm
1171 * here. This is tuned so that an error of about 1 msec is adjusted
1172 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
1174 error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
1175 error2 = abs(error2);
1176 for (look_ahead = 0; error2 > 0; look_ahead++)
1180 * Now calculate the error in (1 << look_ahead) ticks, but first
1181 * remove the single look ahead already included in the error.
1183 tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1);
1184 tick_error -= tk->xtime_interval >> 1;
1185 error = ((error - tick_error) >> look_ahead) + tick_error;
1187 /* Finally calculate the adjustment shift value. */
1192 *interval = -*interval;
1196 for (adj = 0; error > i; adj++)
1205 * Adjust the multiplier to reduce the error value,
1206 * this is optimized for the most common adjustments of -1,0,1,
1207 * for other values we can do a bit more work.
1209 static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
1211 s64 error, interval = tk->cycle_interval;
1215 * The point of this is to check if the error is greater than half
1218 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
1220 * Note we subtract one in the shift, so that error is really error*2.
1221 * This "saves" dividing(shifting) interval twice, but keeps the
1222 * (error > interval) comparison as still measuring if error is
1223 * larger than half an interval.
1225 * Note: It does not "save" on aggravation when reading the code.
1227 error = tk->ntp_error >> (tk->ntp_error_shift - 1);
1228 if (error > interval) {
1230 * We now divide error by 4(via shift), which checks if
1231 * the error is greater than twice the interval.
1232 * If it is greater, we need a bigadjust, if its smaller,
1233 * we can adjust by 1.
1236 if (likely(error <= interval))
1239 adj = timekeeping_bigadjust(tk, error, &interval, &offset);
1241 if (error < -interval) {
1242 /* See comment above, this is just switched for the negative */
1244 if (likely(error >= -interval)) {
1246 interval = -interval;
1249 adj = timekeeping_bigadjust(tk, error, &interval, &offset);
1256 if (unlikely(tk->clock->maxadj &&
1257 (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
1258 printk_deferred_once(KERN_WARNING
1259 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1260 tk->clock->name, (long)tk->mult + adj,
1261 (long)tk->clock->mult + tk->clock->maxadj);
1264 * So the following can be confusing.
1266 * To keep things simple, lets assume adj == 1 for now.
1268 * When adj != 1, remember that the interval and offset values
1269 * have been appropriately scaled so the math is the same.
1271 * The basic idea here is that we're increasing the multiplier
1272 * by one, this causes the xtime_interval to be incremented by
1273 * one cycle_interval. This is because:
1274 * xtime_interval = cycle_interval * mult
1275 * So if mult is being incremented by one:
1276 * xtime_interval = cycle_interval * (mult + 1)
1278 * xtime_interval = (cycle_interval * mult) + cycle_interval
1279 * Which can be shortened to:
1280 * xtime_interval += cycle_interval
1282 * So offset stores the non-accumulated cycles. Thus the current
1283 * time (in shifted nanoseconds) is:
1284 * now = (offset * adj) + xtime_nsec
1285 * Now, even though we're adjusting the clock frequency, we have
1286 * to keep time consistent. In other words, we can't jump back
1287 * in time, and we also want to avoid jumping forward in time.
1289 * So given the same offset value, we need the time to be the same
1290 * both before and after the freq adjustment.
1291 * now = (offset * adj_1) + xtime_nsec_1
1292 * now = (offset * adj_2) + xtime_nsec_2
1294 * (offset * adj_1) + xtime_nsec_1 =
1295 * (offset * adj_2) + xtime_nsec_2
1299 * (offset * adj_1) + xtime_nsec_1 =
1300 * (offset * (adj_1+1)) + xtime_nsec_2
1301 * (offset * adj_1) + xtime_nsec_1 =
1302 * (offset * adj_1) + offset + xtime_nsec_2
1303 * Canceling the sides:
1304 * xtime_nsec_1 = offset + xtime_nsec_2
1306 * xtime_nsec_2 = xtime_nsec_1 - offset
1307 * Which simplfies to:
1308 * xtime_nsec -= offset
1310 * XXX - TODO: Doc ntp_error calculation.
1313 tk->xtime_interval += interval;
1314 tk->xtime_nsec -= offset;
1315 tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
1319 * It may be possible that when we entered this function, xtime_nsec
1320 * was very small. Further, if we're slightly speeding the clocksource
1321 * in the code above, its possible the required corrective factor to
1322 * xtime_nsec could cause it to underflow.
1324 * Now, since we already accumulated the second, cannot simply roll
1325 * the accumulated second back, since the NTP subsystem has been
1326 * notified via second_overflow. So instead we push xtime_nsec forward
1327 * by the amount we underflowed, and add that amount into the error.
1329 * We'll correct this error next time through this function, when
1330 * xtime_nsec is not as small.
1332 if (unlikely((s64)tk->xtime_nsec < 0)) {
1333 s64 neg = -(s64)tk->xtime_nsec;
1335 tk->ntp_error += neg << tk->ntp_error_shift;
1341 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1343 * Helper function that accumulates a the nsecs greater then a second
1344 * from the xtime_nsec field to the xtime_secs field.
1345 * It also calls into the NTP code to handle leapsecond processing.
1348 static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
1350 u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
1351 unsigned int clock_set = 0;
1353 while (tk->xtime_nsec >= nsecps) {
1356 tk->xtime_nsec -= nsecps;
1359 /* Figure out if its a leap sec and apply if needed */
1360 leap = second_overflow(tk->xtime_sec);
1361 if (unlikely(leap)) {
1362 struct timespec64 ts;
1364 tk->xtime_sec += leap;
1368 tk_set_wall_to_mono(tk,
1369 timespec64_sub(tk->wall_to_monotonic, ts));
1371 __timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
1373 clock_set = TK_CLOCK_WAS_SET;
1380 * logarithmic_accumulation - shifted accumulation of cycles
1382 * This functions accumulates a shifted interval of cycles into
1383 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1386 * Returns the unconsumed cycles.
1388 static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
1390 unsigned int *clock_set)
1392 cycle_t interval = tk->cycle_interval << shift;
1395 /* If the offset is smaller then a shifted interval, do nothing */
1396 if (offset < interval)
1399 /* Accumulate one shifted interval */
1401 tk->cycle_last += interval;
1403 tk->xtime_nsec += tk->xtime_interval << shift;
1404 *clock_set |= accumulate_nsecs_to_secs(tk);
1406 /* Accumulate raw time */
1407 raw_nsecs = (u64)tk->raw_interval << shift;
1408 raw_nsecs += tk->raw_time.tv_nsec;
1409 if (raw_nsecs >= NSEC_PER_SEC) {
1410 u64 raw_secs = raw_nsecs;
1411 raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
1412 tk->raw_time.tv_sec += raw_secs;
1414 tk->raw_time.tv_nsec = raw_nsecs;
1416 /* Accumulate error between NTP and clock interval */
1417 tk->ntp_error += ntp_tick_length() << shift;
1418 tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
1419 (tk->ntp_error_shift + shift);
1425 * update_wall_time - Uses the current clocksource to increment the wall time
1428 void update_wall_time(void)
1430 struct clocksource *clock;
1431 struct timekeeper *real_tk = &tk_core.timekeeper;
1432 struct timekeeper *tk = &shadow_timekeeper;
1434 int shift = 0, maxshift;
1435 unsigned int clock_set = 0;
1436 unsigned long flags;
1438 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1440 /* Make sure we're fully resumed: */
1441 if (unlikely(timekeeping_suspended))
1444 clock = real_tk->clock;
1446 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
1447 offset = real_tk->cycle_interval;
1449 offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
1452 /* Check if there's really nothing to do */
1453 if (offset < real_tk->cycle_interval)
1457 * With NO_HZ we may have to accumulate many cycle_intervals
1458 * (think "ticks") worth of time at once. To do this efficiently,
1459 * we calculate the largest doubling multiple of cycle_intervals
1460 * that is smaller than the offset. We then accumulate that
1461 * chunk in one go, and then try to consume the next smaller
1464 shift = ilog2(offset) - ilog2(tk->cycle_interval);
1465 shift = max(0, shift);
1466 /* Bound shift to one less than what overflows tick_length */
1467 maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
1468 shift = min(shift, maxshift);
1469 while (offset >= tk->cycle_interval) {
1470 offset = logarithmic_accumulation(tk, offset, shift,
1472 if (offset < tk->cycle_interval<<shift)
1476 /* correct the clock when NTP error is too big */
1477 timekeeping_adjust(tk, offset);
1480 * XXX This can be killed once everyone converts
1481 * to the new update_vsyscall.
1483 old_vsyscall_fixup(tk);
1486 * Finally, make sure that after the rounding
1487 * xtime_nsec isn't larger than NSEC_PER_SEC
1489 clock_set |= accumulate_nsecs_to_secs(tk);
1491 write_seqcount_begin(&tk_core.seq);
1492 /* Update clock->cycle_last with the new value */
1493 clock->cycle_last = tk->cycle_last;
1495 * Update the real timekeeper.
1497 * We could avoid this memcpy by switching pointers, but that
1498 * requires changes to all other timekeeper usage sites as
1499 * well, i.e. move the timekeeper pointer getter into the
1500 * spinlocked/seqcount protected sections. And we trade this
1501 * memcpy under the tk_core.seq against one before we start
1504 memcpy(real_tk, tk, sizeof(*tk));
1505 timekeeping_update(real_tk, clock_set);
1506 write_seqcount_end(&tk_core.seq);
1508 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1510 /* Have to call _delayed version, since in irq context*/
1511 clock_was_set_delayed();
1515 * getboottime - Return the real time of system boot.
1516 * @ts: pointer to the timespec to be set
1518 * Returns the wall-time of boot in a timespec.
1520 * This is based on the wall_to_monotonic offset and the total suspend
1521 * time. Calls to settimeofday will affect the value returned (which
1522 * basically means that however wrong your real time clock is at boot time,
1523 * you get the right time here).
1525 void getboottime(struct timespec *ts)
1527 struct timekeeper *tk = &tk_core.timekeeper;
1528 struct timespec boottime = {
1529 .tv_sec = tk->wall_to_monotonic.tv_sec +
1530 tk->total_sleep_time.tv_sec,
1531 .tv_nsec = tk->wall_to_monotonic.tv_nsec +
1532 tk->total_sleep_time.tv_nsec
1535 set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
1537 EXPORT_SYMBOL_GPL(getboottime);
1539 unsigned long get_seconds(void)
1541 struct timekeeper *tk = &tk_core.timekeeper;
1543 return tk->xtime_sec;
1545 EXPORT_SYMBOL(get_seconds);
1547 struct timespec __current_kernel_time(void)
1549 struct timekeeper *tk = &tk_core.timekeeper;
1551 return timespec64_to_timespec(tk_xtime(tk));
1554 struct timespec current_kernel_time(void)
1556 struct timekeeper *tk = &tk_core.timekeeper;
1557 struct timespec64 now;
1561 seq = read_seqcount_begin(&tk_core.seq);
1564 } while (read_seqcount_retry(&tk_core.seq, seq));
1566 return timespec64_to_timespec(now);
1568 EXPORT_SYMBOL(current_kernel_time);
1570 struct timespec get_monotonic_coarse(void)
1572 struct timekeeper *tk = &tk_core.timekeeper;
1573 struct timespec64 now, mono;
1577 seq = read_seqcount_begin(&tk_core.seq);
1580 mono = tk->wall_to_monotonic;
1581 } while (read_seqcount_retry(&tk_core.seq, seq));
1583 set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
1584 now.tv_nsec + mono.tv_nsec);
1586 return timespec64_to_timespec(now);
1590 * Must hold jiffies_lock
1592 void do_timer(unsigned long ticks)
1594 jiffies_64 += ticks;
1595 calc_global_load(ticks);
1599 * ktime_get_update_offsets_tick - hrtimer helper
1600 * @offs_real: pointer to storage for monotonic -> realtime offset
1601 * @offs_boot: pointer to storage for monotonic -> boottime offset
1602 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1604 * Returns monotonic time at last tick and various offsets
1606 ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, ktime_t *offs_boot,
1609 struct timekeeper *tk = &tk_core.timekeeper;
1615 seq = read_seqcount_begin(&tk_core.seq);
1617 base = tk->base_mono;
1618 nsecs = tk->xtime_nsec >> tk->shift;
1620 *offs_real = tk->offs_real;
1621 *offs_boot = tk->offs_boot;
1622 *offs_tai = tk->offs_tai;
1623 } while (read_seqcount_retry(&tk_core.seq, seq));
1625 return ktime_add_ns(base, nsecs);
1628 #ifdef CONFIG_HIGH_RES_TIMERS
1630 * ktime_get_update_offsets_now - hrtimer helper
1631 * @offs_real: pointer to storage for monotonic -> realtime offset
1632 * @offs_boot: pointer to storage for monotonic -> boottime offset
1633 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1635 * Returns current monotonic time and updates the offsets
1636 * Called from hrtimer_interrupt() or retrigger_next_event()
1638 ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot,
1641 struct timekeeper *tk = &tk_core.timekeeper;
1647 seq = read_seqcount_begin(&tk_core.seq);
1649 base = tk->base_mono;
1650 nsecs = timekeeping_get_ns(tk);
1652 *offs_real = tk->offs_real;
1653 *offs_boot = tk->offs_boot;
1654 *offs_tai = tk->offs_tai;
1655 } while (read_seqcount_retry(&tk_core.seq, seq));
1657 return ktime_add_ns(base, nsecs);
1662 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1664 int do_adjtimex(struct timex *txc)
1666 struct timekeeper *tk = &tk_core.timekeeper;
1667 unsigned long flags;
1668 struct timespec64 ts;
1672 /* Validate the data before disabling interrupts */
1673 ret = ntp_validate_timex(txc);
1677 if (txc->modes & ADJ_SETOFFSET) {
1678 struct timespec delta;
1679 delta.tv_sec = txc->time.tv_sec;
1680 delta.tv_nsec = txc->time.tv_usec;
1681 if (!(txc->modes & ADJ_NANO))
1682 delta.tv_nsec *= 1000;
1683 ret = timekeeping_inject_offset(&delta);
1688 getnstimeofday64(&ts);
1690 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1691 write_seqcount_begin(&tk_core.seq);
1693 orig_tai = tai = tk->tai_offset;
1694 ret = __do_adjtimex(txc, &ts, &tai);
1696 if (tai != orig_tai) {
1697 __timekeeping_set_tai_offset(tk, tai);
1698 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1700 write_seqcount_end(&tk_core.seq);
1701 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1703 if (tai != orig_tai)
1706 ntp_notify_cmos_timer();
1711 #ifdef CONFIG_NTP_PPS
1713 * hardpps() - Accessor function to NTP __hardpps function
1715 void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
1717 unsigned long flags;
1719 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1720 write_seqcount_begin(&tk_core.seq);
1722 __hardpps(phase_ts, raw_ts);
1724 write_seqcount_end(&tk_core.seq);
1725 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1727 EXPORT_SYMBOL(hardpps);
1731 * xtime_update() - advances the timekeeping infrastructure
1732 * @ticks: number of ticks, that have elapsed since the last call.
1734 * Must be called with interrupts disabled.
1736 void xtime_update(unsigned long ticks)
1738 write_seqlock(&jiffies_lock);
1740 write_sequnlock(&jiffies_lock);