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/nmi.h>
18 #include <linux/sched.h>
19 #include <linux/sched/loadavg.h>
20 #include <linux/syscore_ops.h>
21 #include <linux/clocksource.h>
22 #include <linux/jiffies.h>
23 #include <linux/time.h>
24 #include <linux/tick.h>
25 #include <linux/stop_machine.h>
26 #include <linux/pvclock_gtod.h>
27 #include <linux/compiler.h>
29 #include "tick-internal.h"
30 #include "ntp_internal.h"
31 #include "timekeeping_internal.h"
33 #define TK_CLEAR_NTP (1 << 0)
34 #define TK_MIRROR (1 << 1)
35 #define TK_CLOCK_WAS_SET (1 << 2)
38 * The most important data for readout fits into a single 64 byte
43 struct timekeeper timekeeper;
44 } tk_core ____cacheline_aligned = {
45 .seq = SEQCNT_ZERO(tk_core.seq),
48 static DEFINE_RAW_SPINLOCK(timekeeper_lock);
49 static struct timekeeper shadow_timekeeper;
52 * struct tk_fast - NMI safe timekeeper
53 * @seq: Sequence counter for protecting updates. The lowest bit
54 * is the index for the tk_read_base array
55 * @base: tk_read_base array. Access is indexed by the lowest bit of
58 * See @update_fast_timekeeper() below.
62 struct tk_read_base base[2];
65 static struct tk_fast tk_fast_mono ____cacheline_aligned;
66 static struct tk_fast tk_fast_raw ____cacheline_aligned;
68 /* flag for if timekeeping is suspended */
69 int __read_mostly timekeeping_suspended;
71 static inline void tk_normalize_xtime(struct timekeeper *tk)
73 while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) {
74 tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
77 while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) {
78 tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
83 static inline struct timespec64 tk_xtime(struct timekeeper *tk)
87 ts.tv_sec = tk->xtime_sec;
88 ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
92 static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts)
94 tk->xtime_sec = ts->tv_sec;
95 tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift;
98 static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts)
100 tk->xtime_sec += ts->tv_sec;
101 tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift;
102 tk_normalize_xtime(tk);
105 static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
107 struct timespec64 tmp;
110 * Verify consistency of: offset_real = -wall_to_monotonic
111 * before modifying anything
113 set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec,
114 -tk->wall_to_monotonic.tv_nsec);
115 WARN_ON_ONCE(tk->offs_real != timespec64_to_ktime(tmp));
116 tk->wall_to_monotonic = wtm;
117 set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
118 tk->offs_real = timespec64_to_ktime(tmp);
119 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
122 static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
124 tk->offs_boot = ktime_add(tk->offs_boot, delta);
128 * tk_clock_read - atomic clocksource read() helper
130 * This helper is necessary to use in the read paths because, while the
131 * seqlock ensures we don't return a bad value while structures are updated,
132 * it doesn't protect from potential crashes. There is the possibility that
133 * the tkr's clocksource may change between the read reference, and the
134 * clock reference passed to the read function. This can cause crashes if
135 * the wrong clocksource is passed to the wrong read function.
136 * This isn't necessary to use when holding the timekeeper_lock or doing
137 * a read of the fast-timekeeper tkrs (which is protected by its own locking
140 static inline u64 tk_clock_read(struct tk_read_base *tkr)
142 struct clocksource *clock = READ_ONCE(tkr->clock);
144 return clock->read(clock);
147 #ifdef CONFIG_DEBUG_TIMEKEEPING
148 #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */
150 static void timekeeping_check_update(struct timekeeper *tk, u64 offset)
153 u64 max_cycles = tk->tkr_mono.clock->max_cycles;
154 const char *name = tk->tkr_mono.clock->name;
156 if (offset > max_cycles) {
157 printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n",
158 offset, name, max_cycles);
159 printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n");
161 if (offset > (max_cycles >> 1)) {
162 printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n",
163 offset, name, max_cycles >> 1);
164 printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n");
168 if (tk->underflow_seen) {
169 if (jiffies - tk->last_warning > WARNING_FREQ) {
170 printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name);
171 printk_deferred(" Please report this, consider using a different clocksource, if possible.\n");
172 printk_deferred(" Your kernel is probably still fine.\n");
173 tk->last_warning = jiffies;
175 tk->underflow_seen = 0;
178 if (tk->overflow_seen) {
179 if (jiffies - tk->last_warning > WARNING_FREQ) {
180 printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name);
181 printk_deferred(" Please report this, consider using a different clocksource, if possible.\n");
182 printk_deferred(" Your kernel is probably still fine.\n");
183 tk->last_warning = jiffies;
185 tk->overflow_seen = 0;
189 static inline u64 timekeeping_get_delta(struct tk_read_base *tkr)
191 struct timekeeper *tk = &tk_core.timekeeper;
192 u64 now, last, mask, max, delta;
196 * Since we're called holding a seqlock, the data may shift
197 * under us while we're doing the calculation. This can cause
198 * false positives, since we'd note a problem but throw the
199 * results away. So nest another seqlock here to atomically
200 * grab the points we are checking with.
203 seq = read_seqcount_begin(&tk_core.seq);
204 now = tk_clock_read(tkr);
205 last = tkr->cycle_last;
207 max = tkr->clock->max_cycles;
208 } while (read_seqcount_retry(&tk_core.seq, seq));
210 delta = clocksource_delta(now, last, mask);
213 * Try to catch underflows by checking if we are seeing small
214 * mask-relative negative values.
216 if (unlikely((~delta & mask) < (mask >> 3))) {
217 tk->underflow_seen = 1;
221 /* Cap delta value to the max_cycles values to avoid mult overflows */
222 if (unlikely(delta > max)) {
223 tk->overflow_seen = 1;
224 delta = tkr->clock->max_cycles;
230 static inline void timekeeping_check_update(struct timekeeper *tk, u64 offset)
233 static inline u64 timekeeping_get_delta(struct tk_read_base *tkr)
235 u64 cycle_now, delta;
237 /* read clocksource */
238 cycle_now = tk_clock_read(tkr);
240 /* calculate the delta since the last update_wall_time */
241 delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
248 * tk_setup_internals - Set up internals to use clocksource clock.
250 * @tk: The target timekeeper to setup.
251 * @clock: Pointer to clocksource.
253 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
254 * pair and interval request.
256 * Unless you're the timekeeping code, you should not be using this!
258 static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
261 u64 tmp, ntpinterval;
262 struct clocksource *old_clock;
264 ++tk->cs_was_changed_seq;
265 old_clock = tk->tkr_mono.clock;
266 tk->tkr_mono.clock = clock;
267 tk->tkr_mono.mask = clock->mask;
268 tk->tkr_mono.cycle_last = tk_clock_read(&tk->tkr_mono);
270 tk->tkr_raw.clock = clock;
271 tk->tkr_raw.mask = clock->mask;
272 tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last;
274 /* Do the ns -> cycle conversion first, using original mult */
275 tmp = NTP_INTERVAL_LENGTH;
276 tmp <<= clock->shift;
278 tmp += clock->mult/2;
279 do_div(tmp, clock->mult);
283 interval = (u64) tmp;
284 tk->cycle_interval = interval;
286 /* Go back from cycles -> shifted ns */
287 tk->xtime_interval = interval * clock->mult;
288 tk->xtime_remainder = ntpinterval - tk->xtime_interval;
289 tk->raw_interval = interval * clock->mult;
291 /* if changing clocks, convert xtime_nsec shift units */
293 int shift_change = clock->shift - old_clock->shift;
294 if (shift_change < 0) {
295 tk->tkr_mono.xtime_nsec >>= -shift_change;
296 tk->tkr_raw.xtime_nsec >>= -shift_change;
298 tk->tkr_mono.xtime_nsec <<= shift_change;
299 tk->tkr_raw.xtime_nsec <<= shift_change;
303 tk->tkr_mono.shift = clock->shift;
304 tk->tkr_raw.shift = clock->shift;
307 tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
308 tk->ntp_tick = ntpinterval << tk->ntp_error_shift;
311 * The timekeeper keeps its own mult values for the currently
312 * active clocksource. These value will be adjusted via NTP
313 * to counteract clock drifting.
315 tk->tkr_mono.mult = clock->mult;
316 tk->tkr_raw.mult = clock->mult;
317 tk->ntp_err_mult = 0;
320 /* Timekeeper helper functions. */
322 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
323 static u32 default_arch_gettimeoffset(void) { return 0; }
324 u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
326 static inline u32 arch_gettimeoffset(void) { return 0; }
329 static inline u64 timekeeping_delta_to_ns(struct tk_read_base *tkr, u64 delta)
333 nsec = delta * tkr->mult + tkr->xtime_nsec;
336 /* If arch requires, add in get_arch_timeoffset() */
337 return nsec + arch_gettimeoffset();
340 static inline u64 timekeeping_get_ns(struct tk_read_base *tkr)
344 delta = timekeeping_get_delta(tkr);
345 return timekeeping_delta_to_ns(tkr, delta);
348 static inline u64 timekeeping_cycles_to_ns(struct tk_read_base *tkr, u64 cycles)
352 /* calculate the delta since the last update_wall_time */
353 delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask);
354 return timekeeping_delta_to_ns(tkr, delta);
358 * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
359 * @tkr: Timekeeping readout base from which we take the update
361 * We want to use this from any context including NMI and tracing /
362 * instrumenting the timekeeping code itself.
364 * Employ the latch technique; see @raw_write_seqcount_latch.
366 * So if a NMI hits the update of base[0] then it will use base[1]
367 * which is still consistent. In the worst case this can result is a
368 * slightly wrong timestamp (a few nanoseconds). See
369 * @ktime_get_mono_fast_ns.
371 static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf)
373 struct tk_read_base *base = tkf->base;
375 /* Force readers off to base[1] */
376 raw_write_seqcount_latch(&tkf->seq);
379 memcpy(base, tkr, sizeof(*base));
381 /* Force readers back to base[0] */
382 raw_write_seqcount_latch(&tkf->seq);
385 memcpy(base + 1, base, sizeof(*base));
389 * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic
391 * This timestamp is not guaranteed to be monotonic across an update.
392 * The timestamp is calculated by:
394 * now = base_mono + clock_delta * slope
396 * So if the update lowers the slope, readers who are forced to the
397 * not yet updated second array are still using the old steeper slope.
406 * |12345678---> reader order
412 * So reader 6 will observe time going backwards versus reader 5.
414 * While other CPUs are likely to be able observe that, the only way
415 * for a CPU local observation is when an NMI hits in the middle of
416 * the update. Timestamps taken from that NMI context might be ahead
417 * of the following timestamps. Callers need to be aware of that and
420 static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
422 struct tk_read_base *tkr;
427 seq = raw_read_seqcount_latch(&tkf->seq);
428 tkr = tkf->base + (seq & 0x01);
429 now = ktime_to_ns(tkr->base);
431 now += timekeeping_delta_to_ns(tkr,
436 } while (read_seqcount_retry(&tkf->seq, seq));
441 u64 ktime_get_mono_fast_ns(void)
443 return __ktime_get_fast_ns(&tk_fast_mono);
445 EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);
447 u64 ktime_get_raw_fast_ns(void)
449 return __ktime_get_fast_ns(&tk_fast_raw);
451 EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
454 * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock.
456 * To keep it NMI safe since we're accessing from tracing, we're not using a
457 * separate timekeeper with updates to monotonic clock and boot offset
458 * protected with seqlocks. This has the following minor side effects:
460 * (1) Its possible that a timestamp be taken after the boot offset is updated
461 * but before the timekeeper is updated. If this happens, the new boot offset
462 * is added to the old timekeeping making the clock appear to update slightly
465 * timekeeping_inject_sleeptime64()
466 * __timekeeping_inject_sleeptime(tk, delta);
468 * timekeeping_update(tk, TK_CLEAR_NTP...);
470 * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
471 * partially updated. Since the tk->offs_boot update is a rare event, this
472 * should be a rare occurrence which postprocessing should be able to handle.
474 u64 notrace ktime_get_boot_fast_ns(void)
476 struct timekeeper *tk = &tk_core.timekeeper;
478 return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
480 EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
482 /* Suspend-time cycles value for halted fast timekeeper. */
483 static u64 cycles_at_suspend;
485 static u64 dummy_clock_read(struct clocksource *cs)
487 return cycles_at_suspend;
490 static struct clocksource dummy_clock = {
491 .read = dummy_clock_read,
495 * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource.
496 * @tk: Timekeeper to snapshot.
498 * It generally is unsafe to access the clocksource after timekeeping has been
499 * suspended, so take a snapshot of the readout base of @tk and use it as the
500 * fast timekeeper's readout base while suspended. It will return the same
501 * number of cycles every time until timekeeping is resumed at which time the
502 * proper readout base for the fast timekeeper will be restored automatically.
504 static void halt_fast_timekeeper(struct timekeeper *tk)
506 static struct tk_read_base tkr_dummy;
507 struct tk_read_base *tkr = &tk->tkr_mono;
509 memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy));
510 cycles_at_suspend = tk_clock_read(tkr);
511 tkr_dummy.clock = &dummy_clock;
512 update_fast_timekeeper(&tkr_dummy, &tk_fast_mono);
515 memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy));
516 tkr_dummy.clock = &dummy_clock;
517 update_fast_timekeeper(&tkr_dummy, &tk_fast_raw);
520 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
521 #warning Please contact your maintainers, as GENERIC_TIME_VSYSCALL_OLD compatibity will disappear soon.
523 static inline void update_vsyscall(struct timekeeper *tk)
525 struct timespec xt, wm;
527 xt = timespec64_to_timespec(tk_xtime(tk));
528 wm = timespec64_to_timespec(tk->wall_to_monotonic);
529 update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult,
530 tk->tkr_mono.cycle_last);
533 static inline void old_vsyscall_fixup(struct timekeeper *tk)
538 * Store only full nanoseconds into xtime_nsec after rounding
539 * it up and add the remainder to the error difference.
540 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
541 * by truncating the remainder in vsyscalls. However, it causes
542 * additional work to be done in timekeeping_adjust(). Once
543 * the vsyscall implementations are converted to use xtime_nsec
544 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
545 * users are removed, this can be killed.
547 remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1);
548 if (remainder != 0) {
549 tk->tkr_mono.xtime_nsec -= remainder;
550 tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift;
551 tk->ntp_error += remainder << tk->ntp_error_shift;
552 tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift;
556 #define old_vsyscall_fixup(tk)
559 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
561 static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
563 raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk);
567 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
569 int pvclock_gtod_register_notifier(struct notifier_block *nb)
571 struct timekeeper *tk = &tk_core.timekeeper;
575 raw_spin_lock_irqsave(&timekeeper_lock, flags);
576 ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
577 update_pvclock_gtod(tk, true);
578 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
582 EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
585 * pvclock_gtod_unregister_notifier - unregister a pvclock
586 * timedata update listener
588 int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
593 raw_spin_lock_irqsave(&timekeeper_lock, flags);
594 ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
595 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
599 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
602 * tk_update_leap_state - helper to update the next_leap_ktime
604 static inline void tk_update_leap_state(struct timekeeper *tk)
606 tk->next_leap_ktime = ntp_get_next_leap();
607 if (tk->next_leap_ktime != KTIME_MAX)
608 /* Convert to monotonic time */
609 tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real);
613 * Update the ktime_t based scalar nsec members of the timekeeper
615 static inline void tk_update_ktime_data(struct timekeeper *tk)
621 * The xtime based monotonic readout is:
622 * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now();
623 * The ktime based monotonic readout is:
624 * nsec = base_mono + now();
625 * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec
627 seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
628 nsec = (u32) tk->wall_to_monotonic.tv_nsec;
629 tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
632 * The sum of the nanoseconds portions of xtime and
633 * wall_to_monotonic can be greater/equal one second. Take
634 * this into account before updating tk->ktime_sec.
636 nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
637 if (nsec >= NSEC_PER_SEC)
639 tk->ktime_sec = seconds;
641 /* Update the monotonic raw base */
642 tk->tkr_raw.base = ns_to_ktime(tk->raw_sec * NSEC_PER_SEC);
645 /* must hold timekeeper_lock */
646 static void timekeeping_update(struct timekeeper *tk, unsigned int action)
648 if (action & TK_CLEAR_NTP) {
653 tk_update_leap_state(tk);
654 tk_update_ktime_data(tk);
657 update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
659 update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
660 update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw);
662 if (action & TK_CLOCK_WAS_SET)
663 tk->clock_was_set_seq++;
665 * The mirroring of the data to the shadow-timekeeper needs
666 * to happen last here to ensure we don't over-write the
667 * timekeeper structure on the next update with stale data
669 if (action & TK_MIRROR)
670 memcpy(&shadow_timekeeper, &tk_core.timekeeper,
671 sizeof(tk_core.timekeeper));
675 * timekeeping_forward_now - update clock to the current time
677 * Forward the current clock to update its state since the last call to
678 * update_wall_time(). This is useful before significant clock changes,
679 * as it avoids having to deal with this time offset explicitly.
681 static void timekeeping_forward_now(struct timekeeper *tk)
683 u64 cycle_now, delta;
685 cycle_now = tk_clock_read(&tk->tkr_mono);
686 delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
687 tk->tkr_mono.cycle_last = cycle_now;
688 tk->tkr_raw.cycle_last = cycle_now;
690 tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult;
692 /* If arch requires, add in get_arch_timeoffset() */
693 tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
696 tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;
698 /* If arch requires, add in get_arch_timeoffset() */
699 tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;
701 tk_normalize_xtime(tk);
705 * __getnstimeofday64 - Returns the time of day in a timespec64.
706 * @ts: pointer to the timespec to be set
708 * Updates the time of day in the timespec.
709 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
711 int __getnstimeofday64(struct timespec64 *ts)
713 struct timekeeper *tk = &tk_core.timekeeper;
718 seq = read_seqcount_begin(&tk_core.seq);
720 ts->tv_sec = tk->xtime_sec;
721 nsecs = timekeeping_get_ns(&tk->tkr_mono);
723 } while (read_seqcount_retry(&tk_core.seq, seq));
726 timespec64_add_ns(ts, nsecs);
729 * Do not bail out early, in case there were callers still using
730 * the value, even in the face of the WARN_ON.
732 if (unlikely(timekeeping_suspended))
736 EXPORT_SYMBOL(__getnstimeofday64);
739 * getnstimeofday64 - Returns the time of day in a timespec64.
740 * @ts: pointer to the timespec64 to be set
742 * Returns the time of day in a timespec64 (WARN if suspended).
744 void getnstimeofday64(struct timespec64 *ts)
746 WARN_ON(__getnstimeofday64(ts));
748 EXPORT_SYMBOL(getnstimeofday64);
750 ktime_t ktime_get(void)
752 struct timekeeper *tk = &tk_core.timekeeper;
757 WARN_ON(timekeeping_suspended);
760 seq = read_seqcount_begin(&tk_core.seq);
761 base = tk->tkr_mono.base;
762 nsecs = timekeeping_get_ns(&tk->tkr_mono);
764 } while (read_seqcount_retry(&tk_core.seq, seq));
766 return ktime_add_ns(base, nsecs);
768 EXPORT_SYMBOL_GPL(ktime_get);
770 u32 ktime_get_resolution_ns(void)
772 struct timekeeper *tk = &tk_core.timekeeper;
776 WARN_ON(timekeeping_suspended);
779 seq = read_seqcount_begin(&tk_core.seq);
780 nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift;
781 } while (read_seqcount_retry(&tk_core.seq, seq));
785 EXPORT_SYMBOL_GPL(ktime_get_resolution_ns);
787 static ktime_t *offsets[TK_OFFS_MAX] = {
788 [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
789 [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
790 [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
793 ktime_t ktime_get_with_offset(enum tk_offsets offs)
795 struct timekeeper *tk = &tk_core.timekeeper;
797 ktime_t base, *offset = offsets[offs];
800 WARN_ON(timekeeping_suspended);
803 seq = read_seqcount_begin(&tk_core.seq);
804 base = ktime_add(tk->tkr_mono.base, *offset);
805 nsecs = timekeeping_get_ns(&tk->tkr_mono);
807 } while (read_seqcount_retry(&tk_core.seq, seq));
809 return ktime_add_ns(base, nsecs);
812 EXPORT_SYMBOL_GPL(ktime_get_with_offset);
815 * ktime_mono_to_any() - convert mononotic time to any other time
816 * @tmono: time to convert.
817 * @offs: which offset to use
819 ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
821 ktime_t *offset = offsets[offs];
826 seq = read_seqcount_begin(&tk_core.seq);
827 tconv = ktime_add(tmono, *offset);
828 } while (read_seqcount_retry(&tk_core.seq, seq));
832 EXPORT_SYMBOL_GPL(ktime_mono_to_any);
835 * ktime_get_raw - Returns the raw monotonic time in ktime_t format
837 ktime_t ktime_get_raw(void)
839 struct timekeeper *tk = &tk_core.timekeeper;
845 seq = read_seqcount_begin(&tk_core.seq);
846 base = tk->tkr_raw.base;
847 nsecs = timekeeping_get_ns(&tk->tkr_raw);
849 } while (read_seqcount_retry(&tk_core.seq, seq));
851 return ktime_add_ns(base, nsecs);
853 EXPORT_SYMBOL_GPL(ktime_get_raw);
856 * ktime_get_ts64 - get the monotonic clock in timespec64 format
857 * @ts: pointer to timespec variable
859 * The function calculates the monotonic clock from the realtime
860 * clock and the wall_to_monotonic offset and stores the result
861 * in normalized timespec64 format in the variable pointed to by @ts.
863 void ktime_get_ts64(struct timespec64 *ts)
865 struct timekeeper *tk = &tk_core.timekeeper;
866 struct timespec64 tomono;
870 WARN_ON(timekeeping_suspended);
873 seq = read_seqcount_begin(&tk_core.seq);
874 ts->tv_sec = tk->xtime_sec;
875 nsec = timekeeping_get_ns(&tk->tkr_mono);
876 tomono = tk->wall_to_monotonic;
878 } while (read_seqcount_retry(&tk_core.seq, seq));
880 ts->tv_sec += tomono.tv_sec;
882 timespec64_add_ns(ts, nsec + tomono.tv_nsec);
884 EXPORT_SYMBOL_GPL(ktime_get_ts64);
887 * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC
889 * Returns the seconds portion of CLOCK_MONOTONIC with a single non
890 * serialized read. tk->ktime_sec is of type 'unsigned long' so this
891 * works on both 32 and 64 bit systems. On 32 bit systems the readout
892 * covers ~136 years of uptime which should be enough to prevent
893 * premature wrap arounds.
895 time64_t ktime_get_seconds(void)
897 struct timekeeper *tk = &tk_core.timekeeper;
899 WARN_ON(timekeeping_suspended);
900 return tk->ktime_sec;
902 EXPORT_SYMBOL_GPL(ktime_get_seconds);
905 * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME
907 * Returns the wall clock seconds since 1970. This replaces the
908 * get_seconds() interface which is not y2038 safe on 32bit systems.
910 * For 64bit systems the fast access to tk->xtime_sec is preserved. On
911 * 32bit systems the access must be protected with the sequence
912 * counter to provide "atomic" access to the 64bit tk->xtime_sec
915 time64_t ktime_get_real_seconds(void)
917 struct timekeeper *tk = &tk_core.timekeeper;
921 if (IS_ENABLED(CONFIG_64BIT))
922 return tk->xtime_sec;
925 seq = read_seqcount_begin(&tk_core.seq);
926 seconds = tk->xtime_sec;
928 } while (read_seqcount_retry(&tk_core.seq, seq));
932 EXPORT_SYMBOL_GPL(ktime_get_real_seconds);
935 * __ktime_get_real_seconds - The same as ktime_get_real_seconds
936 * but without the sequence counter protect. This internal function
937 * is called just when timekeeping lock is already held.
939 time64_t __ktime_get_real_seconds(void)
941 struct timekeeper *tk = &tk_core.timekeeper;
943 return tk->xtime_sec;
947 * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter
948 * @systime_snapshot: pointer to struct receiving the system time snapshot
950 void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
952 struct timekeeper *tk = &tk_core.timekeeper;
960 WARN_ON_ONCE(timekeeping_suspended);
963 seq = read_seqcount_begin(&tk_core.seq);
964 now = tk_clock_read(&tk->tkr_mono);
965 systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq;
966 systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq;
967 base_real = ktime_add(tk->tkr_mono.base,
968 tk_core.timekeeper.offs_real);
969 base_raw = tk->tkr_raw.base;
970 nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now);
971 nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
972 } while (read_seqcount_retry(&tk_core.seq, seq));
974 systime_snapshot->cycles = now;
975 systime_snapshot->real = ktime_add_ns(base_real, nsec_real);
976 systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);
978 EXPORT_SYMBOL_GPL(ktime_get_snapshot);
980 /* Scale base by mult/div checking for overflow */
981 static int scale64_check_overflow(u64 mult, u64 div, u64 *base)
985 tmp = div64_u64_rem(*base, div, &rem);
987 if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) ||
988 ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem)))
992 rem = div64_u64(rem * mult, div);
998 * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval
999 * @history: Snapshot representing start of history
1000 * @partial_history_cycles: Cycle offset into history (fractional part)
1001 * @total_history_cycles: Total history length in cycles
1002 * @discontinuity: True indicates clock was set on history period
1003 * @ts: Cross timestamp that should be adjusted using
1004 * partial/total ratio
1006 * Helper function used by get_device_system_crosststamp() to correct the
1007 * crosstimestamp corresponding to the start of the current interval to the
1008 * system counter value (timestamp point) provided by the driver. The
1009 * total_history_* quantities are the total history starting at the provided
1010 * reference point and ending at the start of the current interval. The cycle
1011 * count between the driver timestamp point and the start of the current
1012 * interval is partial_history_cycles.
1014 static int adjust_historical_crosststamp(struct system_time_snapshot *history,
1015 u64 partial_history_cycles,
1016 u64 total_history_cycles,
1018 struct system_device_crosststamp *ts)
1020 struct timekeeper *tk = &tk_core.timekeeper;
1021 u64 corr_raw, corr_real;
1022 bool interp_forward;
1025 if (total_history_cycles == 0 || partial_history_cycles == 0)
1028 /* Interpolate shortest distance from beginning or end of history */
1029 interp_forward = partial_history_cycles > total_history_cycles / 2;
1030 partial_history_cycles = interp_forward ?
1031 total_history_cycles - partial_history_cycles :
1032 partial_history_cycles;
1035 * Scale the monotonic raw time delta by:
1036 * partial_history_cycles / total_history_cycles
1038 corr_raw = (u64)ktime_to_ns(
1039 ktime_sub(ts->sys_monoraw, history->raw));
1040 ret = scale64_check_overflow(partial_history_cycles,
1041 total_history_cycles, &corr_raw);
1046 * If there is a discontinuity in the history, scale monotonic raw
1048 * mult(real)/mult(raw) yielding the realtime correction
1049 * Otherwise, calculate the realtime correction similar to monotonic
1052 if (discontinuity) {
1053 corr_real = mul_u64_u32_div
1054 (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult);
1056 corr_real = (u64)ktime_to_ns(
1057 ktime_sub(ts->sys_realtime, history->real));
1058 ret = scale64_check_overflow(partial_history_cycles,
1059 total_history_cycles, &corr_real);
1064 /* Fixup monotonic raw and real time time values */
1065 if (interp_forward) {
1066 ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw);
1067 ts->sys_realtime = ktime_add_ns(history->real, corr_real);
1069 ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw);
1070 ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real);
1077 * cycle_between - true if test occurs chronologically between before and after
1079 static bool cycle_between(u64 before, u64 test, u64 after)
1081 if (test > before && test < after)
1083 if (test < before && before > after)
1089 * get_device_system_crosststamp - Synchronously capture system/device timestamp
1090 * @get_time_fn: Callback to get simultaneous device time and
1091 * system counter from the device driver
1092 * @ctx: Context passed to get_time_fn()
1093 * @history_begin: Historical reference point used to interpolate system
1094 * time when counter provided by the driver is before the current interval
1095 * @xtstamp: Receives simultaneously captured system and device time
1097 * Reads a timestamp from a device and correlates it to system time
1099 int get_device_system_crosststamp(int (*get_time_fn)
1100 (ktime_t *device_time,
1101 struct system_counterval_t *sys_counterval,
1104 struct system_time_snapshot *history_begin,
1105 struct system_device_crosststamp *xtstamp)
1107 struct system_counterval_t system_counterval;
1108 struct timekeeper *tk = &tk_core.timekeeper;
1109 u64 cycles, now, interval_start;
1110 unsigned int clock_was_set_seq = 0;
1111 ktime_t base_real, base_raw;
1112 u64 nsec_real, nsec_raw;
1113 u8 cs_was_changed_seq;
1119 seq = read_seqcount_begin(&tk_core.seq);
1121 * Try to synchronously capture device time and a system
1122 * counter value calling back into the device driver
1124 ret = get_time_fn(&xtstamp->device, &system_counterval, ctx);
1129 * Verify that the clocksource associated with the captured
1130 * system counter value is the same as the currently installed
1131 * timekeeper clocksource
1133 if (tk->tkr_mono.clock != system_counterval.cs)
1135 cycles = system_counterval.cycles;
1138 * Check whether the system counter value provided by the
1139 * device driver is on the current timekeeping interval.
1141 now = tk_clock_read(&tk->tkr_mono);
1142 interval_start = tk->tkr_mono.cycle_last;
1143 if (!cycle_between(interval_start, cycles, now)) {
1144 clock_was_set_seq = tk->clock_was_set_seq;
1145 cs_was_changed_seq = tk->cs_was_changed_seq;
1146 cycles = interval_start;
1152 base_real = ktime_add(tk->tkr_mono.base,
1153 tk_core.timekeeper.offs_real);
1154 base_raw = tk->tkr_raw.base;
1156 nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono,
1157 system_counterval.cycles);
1158 nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw,
1159 system_counterval.cycles);
1160 } while (read_seqcount_retry(&tk_core.seq, seq));
1162 xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real);
1163 xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw);
1166 * Interpolate if necessary, adjusting back from the start of the
1170 u64 partial_history_cycles, total_history_cycles;
1174 * Check that the counter value occurs after the provided
1175 * history reference and that the history doesn't cross a
1176 * clocksource change
1178 if (!history_begin ||
1179 !cycle_between(history_begin->cycles,
1180 system_counterval.cycles, cycles) ||
1181 history_begin->cs_was_changed_seq != cs_was_changed_seq)
1183 partial_history_cycles = cycles - system_counterval.cycles;
1184 total_history_cycles = cycles - history_begin->cycles;
1186 history_begin->clock_was_set_seq != clock_was_set_seq;
1188 ret = adjust_historical_crosststamp(history_begin,
1189 partial_history_cycles,
1190 total_history_cycles,
1191 discontinuity, xtstamp);
1198 EXPORT_SYMBOL_GPL(get_device_system_crosststamp);
1201 * do_gettimeofday - Returns the time of day in a timeval
1202 * @tv: pointer to the timeval to be set
1204 * NOTE: Users should be converted to using getnstimeofday()
1206 void do_gettimeofday(struct timeval *tv)
1208 struct timespec64 now;
1210 getnstimeofday64(&now);
1211 tv->tv_sec = now.tv_sec;
1212 tv->tv_usec = now.tv_nsec/1000;
1214 EXPORT_SYMBOL(do_gettimeofday);
1217 * do_settimeofday64 - Sets the time of day.
1218 * @ts: pointer to the timespec64 variable containing the new time
1220 * Sets the time of day to the new time and update NTP and notify hrtimers
1222 int do_settimeofday64(const struct timespec64 *ts)
1224 struct timekeeper *tk = &tk_core.timekeeper;
1225 struct timespec64 ts_delta, xt;
1226 unsigned long flags;
1229 if (!timespec64_valid_strict(ts))
1232 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1233 write_seqcount_begin(&tk_core.seq);
1235 timekeeping_forward_now(tk);
1238 ts_delta = timespec64_sub(*ts, xt);
1240 if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) {
1245 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta));
1247 tk_set_xtime(tk, ts);
1249 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1251 write_seqcount_end(&tk_core.seq);
1252 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1254 /* signal hrtimers about time change */
1259 EXPORT_SYMBOL(do_settimeofday64);
1262 * timekeeping_inject_offset - Adds or subtracts from the current time.
1263 * @tv: pointer to the timespec variable containing the offset
1265 * Adds or subtracts an offset value from the current time.
1267 int timekeeping_inject_offset(struct timespec *ts)
1269 struct timekeeper *tk = &tk_core.timekeeper;
1270 unsigned long flags;
1271 struct timespec64 ts64, tmp;
1274 if (!timespec_inject_offset_valid(ts))
1277 ts64 = timespec_to_timespec64(*ts);
1279 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1280 write_seqcount_begin(&tk_core.seq);
1282 timekeeping_forward_now(tk);
1284 /* Make sure the proposed value is valid */
1285 tmp = timespec64_add(tk_xtime(tk), ts64);
1286 if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 ||
1287 !timespec64_valid_strict(&tmp)) {
1292 tk_xtime_add(tk, &ts64);
1293 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64));
1295 error: /* even if we error out, we forwarded the time, so call update */
1296 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1298 write_seqcount_end(&tk_core.seq);
1299 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1301 /* signal hrtimers about time change */
1306 EXPORT_SYMBOL(timekeeping_inject_offset);
1309 * __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic
1312 static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
1314 tk->tai_offset = tai_offset;
1315 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
1319 * change_clocksource - Swaps clocksources if a new one is available
1321 * Accumulates current time interval and initializes new clocksource
1323 static int change_clocksource(void *data)
1325 struct timekeeper *tk = &tk_core.timekeeper;
1326 struct clocksource *new, *old;
1327 unsigned long flags;
1329 new = (struct clocksource *) data;
1331 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1332 write_seqcount_begin(&tk_core.seq);
1334 timekeeping_forward_now(tk);
1336 * If the cs is in module, get a module reference. Succeeds
1337 * for built-in code (owner == NULL) as well.
1339 if (try_module_get(new->owner)) {
1340 if (!new->enable || new->enable(new) == 0) {
1341 old = tk->tkr_mono.clock;
1342 tk_setup_internals(tk, new);
1345 module_put(old->owner);
1347 module_put(new->owner);
1350 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1352 write_seqcount_end(&tk_core.seq);
1353 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1359 * timekeeping_notify - Install a new clock source
1360 * @clock: pointer to the clock source
1362 * This function is called from clocksource.c after a new, better clock
1363 * source has been registered. The caller holds the clocksource_mutex.
1365 int timekeeping_notify(struct clocksource *clock)
1367 struct timekeeper *tk = &tk_core.timekeeper;
1369 if (tk->tkr_mono.clock == clock)
1371 stop_machine(change_clocksource, clock, NULL);
1372 tick_clock_notify();
1373 return tk->tkr_mono.clock == clock ? 0 : -1;
1377 * getrawmonotonic64 - Returns the raw monotonic time in a timespec
1378 * @ts: pointer to the timespec64 to be set
1380 * Returns the raw monotonic time (completely un-modified by ntp)
1382 void getrawmonotonic64(struct timespec64 *ts)
1384 struct timekeeper *tk = &tk_core.timekeeper;
1389 seq = read_seqcount_begin(&tk_core.seq);
1390 ts->tv_sec = tk->raw_sec;
1391 nsecs = timekeeping_get_ns(&tk->tkr_raw);
1393 } while (read_seqcount_retry(&tk_core.seq, seq));
1396 timespec64_add_ns(ts, nsecs);
1398 EXPORT_SYMBOL(getrawmonotonic64);
1402 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
1404 int timekeeping_valid_for_hres(void)
1406 struct timekeeper *tk = &tk_core.timekeeper;
1411 seq = read_seqcount_begin(&tk_core.seq);
1413 ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
1415 } while (read_seqcount_retry(&tk_core.seq, seq));
1421 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
1423 u64 timekeeping_max_deferment(void)
1425 struct timekeeper *tk = &tk_core.timekeeper;
1430 seq = read_seqcount_begin(&tk_core.seq);
1432 ret = tk->tkr_mono.clock->max_idle_ns;
1434 } while (read_seqcount_retry(&tk_core.seq, seq));
1440 * read_persistent_clock - Return time from the persistent clock.
1442 * Weak dummy function for arches that do not yet support it.
1443 * Reads the time from the battery backed persistent clock.
1444 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
1446 * XXX - Do be sure to remove it once all arches implement it.
1448 void __weak read_persistent_clock(struct timespec *ts)
1454 void __weak read_persistent_clock64(struct timespec64 *ts64)
1458 read_persistent_clock(&ts);
1459 *ts64 = timespec_to_timespec64(ts);
1463 * read_boot_clock64 - Return time of the system start.
1465 * Weak dummy function for arches that do not yet support it.
1466 * Function to read the exact time the system has been started.
1467 * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported.
1469 * XXX - Do be sure to remove it once all arches implement it.
1471 void __weak read_boot_clock64(struct timespec64 *ts)
1477 /* Flag for if timekeeping_resume() has injected sleeptime */
1478 static bool sleeptime_injected;
1480 /* Flag for if there is a persistent clock on this platform */
1481 static bool persistent_clock_exists;
1484 * timekeeping_init - Initializes the clocksource and common timekeeping values
1486 void __init timekeeping_init(void)
1488 struct timekeeper *tk = &tk_core.timekeeper;
1489 struct clocksource *clock;
1490 unsigned long flags;
1491 struct timespec64 now, boot, tmp;
1493 read_persistent_clock64(&now);
1494 if (!timespec64_valid_strict(&now)) {
1495 pr_warn("WARNING: Persistent clock returned invalid value!\n"
1496 " Check your CMOS/BIOS settings.\n");
1499 } else if (now.tv_sec || now.tv_nsec)
1500 persistent_clock_exists = true;
1502 read_boot_clock64(&boot);
1503 if (!timespec64_valid_strict(&boot)) {
1504 pr_warn("WARNING: Boot clock returned invalid value!\n"
1505 " Check your CMOS/BIOS settings.\n");
1510 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1511 write_seqcount_begin(&tk_core.seq);
1514 clock = clocksource_default_clock();
1516 clock->enable(clock);
1517 tk_setup_internals(tk, clock);
1519 tk_set_xtime(tk, &now);
1521 if (boot.tv_sec == 0 && boot.tv_nsec == 0)
1522 boot = tk_xtime(tk);
1524 set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec);
1525 tk_set_wall_to_mono(tk, tmp);
1527 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1529 write_seqcount_end(&tk_core.seq);
1530 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1533 /* time in seconds when suspend began for persistent clock */
1534 static struct timespec64 timekeeping_suspend_time;
1537 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
1538 * @delta: pointer to a timespec delta value
1540 * Takes a timespec offset measuring a suspend interval and properly
1541 * adds the sleep offset to the timekeeping variables.
1543 static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
1544 struct timespec64 *delta)
1546 if (!timespec64_valid_strict(delta)) {
1547 printk_deferred(KERN_WARNING
1548 "__timekeeping_inject_sleeptime: Invalid "
1549 "sleep delta value!\n");
1552 tk_xtime_add(tk, delta);
1553 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
1554 tk_update_sleep_time(tk, timespec64_to_ktime(*delta));
1555 tk_debug_account_sleep_time(delta);
1558 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
1560 * We have three kinds of time sources to use for sleep time
1561 * injection, the preference order is:
1562 * 1) non-stop clocksource
1563 * 2) persistent clock (ie: RTC accessible when irqs are off)
1566 * 1) and 2) are used by timekeeping, 3) by RTC subsystem.
1567 * If system has neither 1) nor 2), 3) will be used finally.
1570 * If timekeeping has injected sleeptime via either 1) or 2),
1571 * 3) becomes needless, so in this case we don't need to call
1572 * rtc_resume(), and this is what timekeeping_rtc_skipresume()
1575 bool timekeeping_rtc_skipresume(void)
1577 return sleeptime_injected;
1581 * 1) can be determined whether to use or not only when doing
1582 * timekeeping_resume() which is invoked after rtc_suspend(),
1583 * so we can't skip rtc_suspend() surely if system has 1).
1585 * But if system has 2), 2) will definitely be used, so in this
1586 * case we don't need to call rtc_suspend(), and this is what
1587 * timekeeping_rtc_skipsuspend() means.
1589 bool timekeeping_rtc_skipsuspend(void)
1591 return persistent_clock_exists;
1595 * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values
1596 * @delta: pointer to a timespec64 delta value
1598 * This hook is for architectures that cannot support read_persistent_clock64
1599 * because their RTC/persistent clock is only accessible when irqs are enabled.
1600 * and also don't have an effective nonstop clocksource.
1602 * This function should only be called by rtc_resume(), and allows
1603 * a suspend offset to be injected into the timekeeping values.
1605 void timekeeping_inject_sleeptime64(struct timespec64 *delta)
1607 struct timekeeper *tk = &tk_core.timekeeper;
1608 unsigned long flags;
1610 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1611 write_seqcount_begin(&tk_core.seq);
1613 timekeeping_forward_now(tk);
1615 __timekeeping_inject_sleeptime(tk, delta);
1617 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1619 write_seqcount_end(&tk_core.seq);
1620 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1622 /* signal hrtimers about time change */
1628 * timekeeping_resume - Resumes the generic timekeeping subsystem.
1630 void timekeeping_resume(void)
1632 struct timekeeper *tk = &tk_core.timekeeper;
1633 struct clocksource *clock = tk->tkr_mono.clock;
1634 unsigned long flags;
1635 struct timespec64 ts_new, ts_delta;
1638 sleeptime_injected = false;
1639 read_persistent_clock64(&ts_new);
1641 clockevents_resume();
1642 clocksource_resume();
1644 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1645 write_seqcount_begin(&tk_core.seq);
1648 * After system resumes, we need to calculate the suspended time and
1649 * compensate it for the OS time. There are 3 sources that could be
1650 * used: Nonstop clocksource during suspend, persistent clock and rtc
1653 * One specific platform may have 1 or 2 or all of them, and the
1654 * preference will be:
1655 * suspend-nonstop clocksource -> persistent clock -> rtc
1656 * The less preferred source will only be tried if there is no better
1657 * usable source. The rtc part is handled separately in rtc core code.
1659 cycle_now = tk_clock_read(&tk->tkr_mono);
1660 if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
1661 cycle_now > tk->tkr_mono.cycle_last) {
1662 u64 nsec, cyc_delta;
1664 cyc_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last,
1666 nsec = mul_u64_u32_shr(cyc_delta, clock->mult, clock->shift);
1667 ts_delta = ns_to_timespec64(nsec);
1668 sleeptime_injected = true;
1669 } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
1670 ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time);
1671 sleeptime_injected = true;
1674 if (sleeptime_injected)
1675 __timekeeping_inject_sleeptime(tk, &ts_delta);
1677 /* Re-base the last cycle value */
1678 tk->tkr_mono.cycle_last = cycle_now;
1679 tk->tkr_raw.cycle_last = cycle_now;
1682 timekeeping_suspended = 0;
1683 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1684 write_seqcount_end(&tk_core.seq);
1685 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1687 touch_softlockup_watchdog();
1693 int timekeeping_suspend(void)
1695 struct timekeeper *tk = &tk_core.timekeeper;
1696 unsigned long flags;
1697 struct timespec64 delta, delta_delta;
1698 static struct timespec64 old_delta;
1700 read_persistent_clock64(&timekeeping_suspend_time);
1703 * On some systems the persistent_clock can not be detected at
1704 * timekeeping_init by its return value, so if we see a valid
1705 * value returned, update the persistent_clock_exists flag.
1707 if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec)
1708 persistent_clock_exists = true;
1710 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1711 write_seqcount_begin(&tk_core.seq);
1712 timekeeping_forward_now(tk);
1713 timekeeping_suspended = 1;
1715 if (persistent_clock_exists) {
1717 * To avoid drift caused by repeated suspend/resumes,
1718 * which each can add ~1 second drift error,
1719 * try to compensate so the difference in system time
1720 * and persistent_clock time stays close to constant.
1722 delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time);
1723 delta_delta = timespec64_sub(delta, old_delta);
1724 if (abs(delta_delta.tv_sec) >= 2) {
1726 * if delta_delta is too large, assume time correction
1727 * has occurred and set old_delta to the current delta.
1731 /* Otherwise try to adjust old_system to compensate */
1732 timekeeping_suspend_time =
1733 timespec64_add(timekeeping_suspend_time, delta_delta);
1737 timekeeping_update(tk, TK_MIRROR);
1738 halt_fast_timekeeper(tk);
1739 write_seqcount_end(&tk_core.seq);
1740 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1743 clocksource_suspend();
1744 clockevents_suspend();
1749 /* sysfs resume/suspend bits for timekeeping */
1750 static struct syscore_ops timekeeping_syscore_ops = {
1751 .resume = timekeeping_resume,
1752 .suspend = timekeeping_suspend,
1755 static int __init timekeeping_init_ops(void)
1757 register_syscore_ops(&timekeeping_syscore_ops);
1760 device_initcall(timekeeping_init_ops);
1763 * Apply a multiplier adjustment to the timekeeper
1765 static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk,
1770 s64 interval = tk->cycle_interval;
1774 mult_adj = -mult_adj;
1775 interval = -interval;
1778 mult_adj <<= adj_scale;
1779 interval <<= adj_scale;
1780 offset <<= adj_scale;
1783 * So the following can be confusing.
1785 * To keep things simple, lets assume mult_adj == 1 for now.
1787 * When mult_adj != 1, remember that the interval and offset values
1788 * have been appropriately scaled so the math is the same.
1790 * The basic idea here is that we're increasing the multiplier
1791 * by one, this causes the xtime_interval to be incremented by
1792 * one cycle_interval. This is because:
1793 * xtime_interval = cycle_interval * mult
1794 * So if mult is being incremented by one:
1795 * xtime_interval = cycle_interval * (mult + 1)
1797 * xtime_interval = (cycle_interval * mult) + cycle_interval
1798 * Which can be shortened to:
1799 * xtime_interval += cycle_interval
1801 * So offset stores the non-accumulated cycles. Thus the current
1802 * time (in shifted nanoseconds) is:
1803 * now = (offset * adj) + xtime_nsec
1804 * Now, even though we're adjusting the clock frequency, we have
1805 * to keep time consistent. In other words, we can't jump back
1806 * in time, and we also want to avoid jumping forward in time.
1808 * So given the same offset value, we need the time to be the same
1809 * both before and after the freq adjustment.
1810 * now = (offset * adj_1) + xtime_nsec_1
1811 * now = (offset * adj_2) + xtime_nsec_2
1813 * (offset * adj_1) + xtime_nsec_1 =
1814 * (offset * adj_2) + xtime_nsec_2
1818 * (offset * adj_1) + xtime_nsec_1 =
1819 * (offset * (adj_1+1)) + xtime_nsec_2
1820 * (offset * adj_1) + xtime_nsec_1 =
1821 * (offset * adj_1) + offset + xtime_nsec_2
1822 * Canceling the sides:
1823 * xtime_nsec_1 = offset + xtime_nsec_2
1825 * xtime_nsec_2 = xtime_nsec_1 - offset
1826 * Which simplfies to:
1827 * xtime_nsec -= offset
1829 * XXX - TODO: Doc ntp_error calculation.
1831 if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) {
1832 /* NTP adjustment caused clocksource mult overflow */
1837 tk->tkr_mono.mult += mult_adj;
1838 tk->xtime_interval += interval;
1839 tk->tkr_mono.xtime_nsec -= offset;
1840 tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
1844 * Calculate the multiplier adjustment needed to match the frequency
1847 static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
1850 s64 interval = tk->cycle_interval;
1851 s64 xinterval = tk->xtime_interval;
1852 u32 base = tk->tkr_mono.clock->mult;
1853 u32 max = tk->tkr_mono.clock->maxadj;
1854 u32 cur_adj = tk->tkr_mono.mult;
1859 /* Remove any current error adj from freq calculation */
1860 if (tk->ntp_err_mult)
1861 xinterval -= tk->cycle_interval;
1863 tk->ntp_tick = ntp_tick_length();
1865 /* Calculate current error per tick */
1866 tick_error = ntp_tick_length() >> tk->ntp_error_shift;
1867 tick_error -= (xinterval + tk->xtime_remainder);
1869 /* Don't worry about correcting it if its small */
1870 if (likely((tick_error >= 0) && (tick_error <= interval)))
1873 /* preserve the direction of correction */
1874 negative = (tick_error < 0);
1876 /* If any adjustment would pass the max, just return */
1877 if (negative && (cur_adj - 1) <= (base - max))
1879 if (!negative && (cur_adj + 1) >= (base + max))
1882 * Sort out the magnitude of the correction, but
1883 * avoid making so large a correction that we go
1884 * over the max adjustment.
1887 tick_error = abs(tick_error);
1888 while (tick_error > interval) {
1889 u32 adj = 1 << (adj_scale + 1);
1891 /* Check if adjustment gets us within 1 unit from the max */
1892 if (negative && (cur_adj - adj) <= (base - max))
1894 if (!negative && (cur_adj + adj) >= (base + max))
1901 /* scale the corrections */
1902 timekeeping_apply_adjustment(tk, offset, negative, adj_scale);
1906 * Adjust the timekeeper's multiplier to the correct frequency
1907 * and also to reduce the accumulated error value.
1909 static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
1911 /* Correct for the current frequency error */
1912 timekeeping_freqadjust(tk, offset);
1914 /* Next make a small adjustment to fix any cumulative error */
1915 if (!tk->ntp_err_mult && (tk->ntp_error > 0)) {
1916 tk->ntp_err_mult = 1;
1917 timekeeping_apply_adjustment(tk, offset, 0, 0);
1918 } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) {
1919 /* Undo any existing error adjustment */
1920 timekeeping_apply_adjustment(tk, offset, 1, 0);
1921 tk->ntp_err_mult = 0;
1924 if (unlikely(tk->tkr_mono.clock->maxadj &&
1925 (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult)
1926 > tk->tkr_mono.clock->maxadj))) {
1927 printk_once(KERN_WARNING
1928 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1929 tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult,
1930 (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj);
1934 * It may be possible that when we entered this function, xtime_nsec
1935 * was very small. Further, if we're slightly speeding the clocksource
1936 * in the code above, its possible the required corrective factor to
1937 * xtime_nsec could cause it to underflow.
1939 * Now, since we already accumulated the second, cannot simply roll
1940 * the accumulated second back, since the NTP subsystem has been
1941 * notified via second_overflow. So instead we push xtime_nsec forward
1942 * by the amount we underflowed, and add that amount into the error.
1944 * We'll correct this error next time through this function, when
1945 * xtime_nsec is not as small.
1947 if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) {
1948 s64 neg = -(s64)tk->tkr_mono.xtime_nsec;
1949 tk->tkr_mono.xtime_nsec = 0;
1950 tk->ntp_error += neg << tk->ntp_error_shift;
1955 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1957 * Helper function that accumulates the nsecs greater than a second
1958 * from the xtime_nsec field to the xtime_secs field.
1959 * It also calls into the NTP code to handle leapsecond processing.
1962 static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
1964 u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
1965 unsigned int clock_set = 0;
1967 while (tk->tkr_mono.xtime_nsec >= nsecps) {
1970 tk->tkr_mono.xtime_nsec -= nsecps;
1973 /* Figure out if its a leap sec and apply if needed */
1974 leap = second_overflow(tk->xtime_sec);
1975 if (unlikely(leap)) {
1976 struct timespec64 ts;
1978 tk->xtime_sec += leap;
1982 tk_set_wall_to_mono(tk,
1983 timespec64_sub(tk->wall_to_monotonic, ts));
1985 __timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
1987 clock_set = TK_CLOCK_WAS_SET;
1994 * logarithmic_accumulation - shifted accumulation of cycles
1996 * This functions accumulates a shifted interval of cycles into
1997 * into a shifted interval nanoseconds. Allows for O(log) accumulation
2000 * Returns the unconsumed cycles.
2002 static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
2003 u32 shift, unsigned int *clock_set)
2005 u64 interval = tk->cycle_interval << shift;
2008 /* If the offset is smaller than a shifted interval, do nothing */
2009 if (offset < interval)
2012 /* Accumulate one shifted interval */
2014 tk->tkr_mono.cycle_last += interval;
2015 tk->tkr_raw.cycle_last += interval;
2017 tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift;
2018 *clock_set |= accumulate_nsecs_to_secs(tk);
2020 /* Accumulate raw time */
2021 tk->tkr_raw.xtime_nsec += tk->raw_interval << shift;
2022 snsec_per_sec = (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
2023 while (tk->tkr_raw.xtime_nsec >= snsec_per_sec) {
2024 tk->tkr_raw.xtime_nsec -= snsec_per_sec;
2028 /* Accumulate error between NTP and clock interval */
2029 tk->ntp_error += tk->ntp_tick << shift;
2030 tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
2031 (tk->ntp_error_shift + shift);
2037 * update_wall_time - Uses the current clocksource to increment the wall time
2040 void update_wall_time(void)
2042 struct timekeeper *real_tk = &tk_core.timekeeper;
2043 struct timekeeper *tk = &shadow_timekeeper;
2045 int shift = 0, maxshift;
2046 unsigned int clock_set = 0;
2047 unsigned long flags;
2049 raw_spin_lock_irqsave(&timekeeper_lock, flags);
2051 /* Make sure we're fully resumed: */
2052 if (unlikely(timekeeping_suspended))
2055 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
2056 offset = real_tk->cycle_interval;
2058 offset = clocksource_delta(tk_clock_read(&tk->tkr_mono),
2059 tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
2062 /* Check if there's really nothing to do */
2063 if (offset < real_tk->cycle_interval)
2066 /* Do some additional sanity checking */
2067 timekeeping_check_update(tk, offset);
2070 * With NO_HZ we may have to accumulate many cycle_intervals
2071 * (think "ticks") worth of time at once. To do this efficiently,
2072 * we calculate the largest doubling multiple of cycle_intervals
2073 * that is smaller than the offset. We then accumulate that
2074 * chunk in one go, and then try to consume the next smaller
2077 shift = ilog2(offset) - ilog2(tk->cycle_interval);
2078 shift = max(0, shift);
2079 /* Bound shift to one less than what overflows tick_length */
2080 maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
2081 shift = min(shift, maxshift);
2082 while (offset >= tk->cycle_interval) {
2083 offset = logarithmic_accumulation(tk, offset, shift,
2085 if (offset < tk->cycle_interval<<shift)
2089 /* correct the clock when NTP error is too big */
2090 timekeeping_adjust(tk, offset);
2093 * XXX This can be killed once everyone converts
2094 * to the new update_vsyscall.
2096 old_vsyscall_fixup(tk);
2099 * Finally, make sure that after the rounding
2100 * xtime_nsec isn't larger than NSEC_PER_SEC
2102 clock_set |= accumulate_nsecs_to_secs(tk);
2104 write_seqcount_begin(&tk_core.seq);
2106 * Update the real timekeeper.
2108 * We could avoid this memcpy by switching pointers, but that
2109 * requires changes to all other timekeeper usage sites as
2110 * well, i.e. move the timekeeper pointer getter into the
2111 * spinlocked/seqcount protected sections. And we trade this
2112 * memcpy under the tk_core.seq against one before we start
2115 timekeeping_update(tk, clock_set);
2116 memcpy(real_tk, tk, sizeof(*tk));
2117 /* The memcpy must come last. Do not put anything here! */
2118 write_seqcount_end(&tk_core.seq);
2120 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2122 /* Have to call _delayed version, since in irq context*/
2123 clock_was_set_delayed();
2127 * getboottime64 - Return the real time of system boot.
2128 * @ts: pointer to the timespec64 to be set
2130 * Returns the wall-time of boot in a timespec64.
2132 * This is based on the wall_to_monotonic offset and the total suspend
2133 * time. Calls to settimeofday will affect the value returned (which
2134 * basically means that however wrong your real time clock is at boot time,
2135 * you get the right time here).
2137 void getboottime64(struct timespec64 *ts)
2139 struct timekeeper *tk = &tk_core.timekeeper;
2140 ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
2142 *ts = ktime_to_timespec64(t);
2144 EXPORT_SYMBOL_GPL(getboottime64);
2146 unsigned long get_seconds(void)
2148 struct timekeeper *tk = &tk_core.timekeeper;
2150 return tk->xtime_sec;
2152 EXPORT_SYMBOL(get_seconds);
2154 struct timespec __current_kernel_time(void)
2156 struct timekeeper *tk = &tk_core.timekeeper;
2158 return timespec64_to_timespec(tk_xtime(tk));
2161 struct timespec64 current_kernel_time64(void)
2163 struct timekeeper *tk = &tk_core.timekeeper;
2164 struct timespec64 now;
2168 seq = read_seqcount_begin(&tk_core.seq);
2171 } while (read_seqcount_retry(&tk_core.seq, seq));
2175 EXPORT_SYMBOL(current_kernel_time64);
2177 struct timespec64 get_monotonic_coarse64(void)
2179 struct timekeeper *tk = &tk_core.timekeeper;
2180 struct timespec64 now, mono;
2184 seq = read_seqcount_begin(&tk_core.seq);
2187 mono = tk->wall_to_monotonic;
2188 } while (read_seqcount_retry(&tk_core.seq, seq));
2190 set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
2191 now.tv_nsec + mono.tv_nsec);
2195 EXPORT_SYMBOL(get_monotonic_coarse64);
2198 * Must hold jiffies_lock
2200 void do_timer(unsigned long ticks)
2202 jiffies_64 += ticks;
2203 calc_global_load(ticks);
2207 * ktime_get_update_offsets_now - hrtimer helper
2208 * @cwsseq: pointer to check and store the clock was set sequence number
2209 * @offs_real: pointer to storage for monotonic -> realtime offset
2210 * @offs_boot: pointer to storage for monotonic -> boottime offset
2211 * @offs_tai: pointer to storage for monotonic -> clock tai offset
2213 * Returns current monotonic time and updates the offsets if the
2214 * sequence number in @cwsseq and timekeeper.clock_was_set_seq are
2217 * Called from hrtimer_interrupt() or retrigger_next_event()
2219 ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
2220 ktime_t *offs_boot, ktime_t *offs_tai)
2222 struct timekeeper *tk = &tk_core.timekeeper;
2228 seq = read_seqcount_begin(&tk_core.seq);
2230 base = tk->tkr_mono.base;
2231 nsecs = timekeeping_get_ns(&tk->tkr_mono);
2232 base = ktime_add_ns(base, nsecs);
2234 if (*cwsseq != tk->clock_was_set_seq) {
2235 *cwsseq = tk->clock_was_set_seq;
2236 *offs_real = tk->offs_real;
2237 *offs_boot = tk->offs_boot;
2238 *offs_tai = tk->offs_tai;
2241 /* Handle leapsecond insertion adjustments */
2242 if (unlikely(base >= tk->next_leap_ktime))
2243 *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0));
2245 } while (read_seqcount_retry(&tk_core.seq, seq));
2251 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
2253 int do_adjtimex(struct timex *txc)
2255 struct timekeeper *tk = &tk_core.timekeeper;
2256 unsigned long flags;
2257 struct timespec64 ts;
2261 /* Validate the data before disabling interrupts */
2262 ret = ntp_validate_timex(txc);
2266 if (txc->modes & ADJ_SETOFFSET) {
2267 struct timespec delta;
2268 delta.tv_sec = txc->time.tv_sec;
2269 delta.tv_nsec = txc->time.tv_usec;
2270 if (!(txc->modes & ADJ_NANO))
2271 delta.tv_nsec *= 1000;
2272 ret = timekeeping_inject_offset(&delta);
2277 getnstimeofday64(&ts);
2279 raw_spin_lock_irqsave(&timekeeper_lock, flags);
2280 write_seqcount_begin(&tk_core.seq);
2282 orig_tai = tai = tk->tai_offset;
2283 ret = __do_adjtimex(txc, &ts, &tai);
2285 if (tai != orig_tai) {
2286 __timekeeping_set_tai_offset(tk, tai);
2287 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
2289 tk_update_leap_state(tk);
2291 write_seqcount_end(&tk_core.seq);
2292 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2294 if (tai != orig_tai)
2297 ntp_notify_cmos_timer();
2302 #ifdef CONFIG_NTP_PPS
2304 * hardpps() - Accessor function to NTP __hardpps function
2306 void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
2308 unsigned long flags;
2310 raw_spin_lock_irqsave(&timekeeper_lock, flags);
2311 write_seqcount_begin(&tk_core.seq);
2313 __hardpps(phase_ts, raw_ts);
2315 write_seqcount_end(&tk_core.seq);
2316 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2318 EXPORT_SYMBOL(hardpps);
2319 #endif /* CONFIG_NTP_PPS */
2322 * xtime_update() - advances the timekeeping infrastructure
2323 * @ticks: number of ticks, that have elapsed since the last call.
2325 * Must be called with interrupts disabled.
2327 void xtime_update(unsigned long ticks)
2329 write_seqlock(&jiffies_lock);
2331 write_sequnlock(&jiffies_lock);