projects/linux·blob v4.2 · refs

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1/*
2 * linux/kernel/time/timekeeping.c
3 *
4 * Kernel timekeeping code and accessor functions
5 *
6 * This code was moved from linux/kernel/timer.c.
7 * Please see that file for copyright and history logs.
8 *
9 */
10
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>
16#include <linux/mm.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>
26
27#include "tick-internal.h"
28#include "ntp_internal.h"
29#include "timekeeping_internal.h"
30
31#define TK_CLEAR_NTP (1 << 0)
32#define TK_MIRROR (1 << 1)
33#define TK_CLOCK_WAS_SET (1 << 2)
34
35/*
36 * The most important data for readout fits into a single 64 byte
37 * cache line.
38 */
39static struct {
40 seqcount_t seq;
41 struct timekeeper timekeeper;
42} tk_core ____cacheline_aligned;
43
44static DEFINE_RAW_SPINLOCK(timekeeper_lock);
45static struct timekeeper shadow_timekeeper;
46
47/**
48 * struct tk_fast - NMI safe timekeeper
49 * @seq: Sequence counter for protecting updates. The lowest bit
50 * is the index for the tk_read_base array
51 * @base: tk_read_base array. Access is indexed by the lowest bit of
52 * @seq.
53 *
54 * See @update_fast_timekeeper() below.
55 */
56struct tk_fast {
57 seqcount_t seq;
58 struct tk_read_base base[2];
59};
60
61static struct tk_fast tk_fast_mono ____cacheline_aligned;
62static struct tk_fast tk_fast_raw ____cacheline_aligned;
63
64/* flag for if timekeeping is suspended */
65int __read_mostly timekeeping_suspended;
66
67static inline void tk_normalize_xtime(struct timekeeper *tk)
68{
69 while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) {
70 tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
71 tk->xtime_sec++;
72 }
73}
74
75static inline struct timespec64 tk_xtime(struct timekeeper *tk)
76{
77 struct timespec64 ts;
78
79 ts.tv_sec = tk->xtime_sec;
80 ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
81 return ts;
82}
83
84static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts)
85{
86 tk->xtime_sec = ts->tv_sec;
87 tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift;
88}
89
90static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts)
91{
92 tk->xtime_sec += ts->tv_sec;
93 tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift;
94 tk_normalize_xtime(tk);
95}
96
97static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
98{
99 struct timespec64 tmp;
100
101 /*
102 * Verify consistency of: offset_real = -wall_to_monotonic
103 * before modifying anything
104 */
105 set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec,
106 -tk->wall_to_monotonic.tv_nsec);
107 WARN_ON_ONCE(tk->offs_real.tv64 != timespec64_to_ktime(tmp).tv64);
108 tk->wall_to_monotonic = wtm;
109 set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
110 tk->offs_real = timespec64_to_ktime(tmp);
111 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
112}
113
114static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
115{
116 tk->offs_boot = ktime_add(tk->offs_boot, delta);
117}
118
119#ifdef CONFIG_DEBUG_TIMEKEEPING
120#define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */
121
122static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
123{
124
125 cycle_t max_cycles = tk->tkr_mono.clock->max_cycles;
126 const char *name = tk->tkr_mono.clock->name;
127
128 if (offset > max_cycles) {
129 printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n",
130 offset, name, max_cycles);
131 printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n");
132 } else {
133 if (offset > (max_cycles >> 1)) {
134 printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the the '%s' clock's 50%% safety margin (%lld)\n",
135 offset, name, max_cycles >> 1);
136 printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n");
137 }
138 }
139
140 if (tk->underflow_seen) {
141 if (jiffies - tk->last_warning > WARNING_FREQ) {
142 printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name);
143 printk_deferred(" Please report this, consider using a different clocksource, if possible.\n");
144 printk_deferred(" Your kernel is probably still fine.\n");
145 tk->last_warning = jiffies;
146 }
147 tk->underflow_seen = 0;
148 }
149
150 if (tk->overflow_seen) {
151 if (jiffies - tk->last_warning > WARNING_FREQ) {
152 printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name);
153 printk_deferred(" Please report this, consider using a different clocksource, if possible.\n");
154 printk_deferred(" Your kernel is probably still fine.\n");
155 tk->last_warning = jiffies;
156 }
157 tk->overflow_seen = 0;
158 }
159}
160
161static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
162{
163 struct timekeeper *tk = &tk_core.timekeeper;
164 cycle_t now, last, mask, max, delta;
165 unsigned int seq;
166
167 /*
168 * Since we're called holding a seqlock, the data may shift
169 * under us while we're doing the calculation. This can cause
170 * false positives, since we'd note a problem but throw the
171 * results away. So nest another seqlock here to atomically
172 * grab the points we are checking with.
173 */
174 do {
175 seq = read_seqcount_begin(&tk_core.seq);
176 now = tkr->read(tkr->clock);
177 last = tkr->cycle_last;
178 mask = tkr->mask;
179 max = tkr->clock->max_cycles;
180 } while (read_seqcount_retry(&tk_core.seq, seq));
181
182 delta = clocksource_delta(now, last, mask);
183
184 /*
185 * Try to catch underflows by checking if we are seeing small
186 * mask-relative negative values.
187 */
188 if (unlikely((~delta & mask) < (mask >> 3))) {
189 tk->underflow_seen = 1;
190 delta = 0;
191 }
192
193 /* Cap delta value to the max_cycles values to avoid mult overflows */
194 if (unlikely(delta > max)) {
195 tk->overflow_seen = 1;
196 delta = tkr->clock->max_cycles;
197 }
198
199 return delta;
200}
201#else
202static inline void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
203{
204}
205static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
206{
207 cycle_t cycle_now, delta;
208
209 /* read clocksource */
210 cycle_now = tkr->read(tkr->clock);
211
212 /* calculate the delta since the last update_wall_time */
213 delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
214
215 return delta;
216}
217#endif
218
219/**
220 * tk_setup_internals - Set up internals to use clocksource clock.
221 *
222 * @tk: The target timekeeper to setup.
223 * @clock: Pointer to clocksource.
224 *
225 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
226 * pair and interval request.
227 *
228 * Unless you're the timekeeping code, you should not be using this!
229 */
230static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
231{
232 cycle_t interval;
233 u64 tmp, ntpinterval;
234 struct clocksource *old_clock;
235
236 old_clock = tk->tkr_mono.clock;
237 tk->tkr_mono.clock = clock;
238 tk->tkr_mono.read = clock->read;
239 tk->tkr_mono.mask = clock->mask;
240 tk->tkr_mono.cycle_last = tk->tkr_mono.read(clock);
241
242 tk->tkr_raw.clock = clock;
243 tk->tkr_raw.read = clock->read;
244 tk->tkr_raw.mask = clock->mask;
245 tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last;
246
247 /* Do the ns -> cycle conversion first, using original mult */
248 tmp = NTP_INTERVAL_LENGTH;
249 tmp <<= clock->shift;
250 ntpinterval = tmp;
251 tmp += clock->mult/2;
252 do_div(tmp, clock->mult);
253 if (tmp == 0)
254 tmp = 1;
255
256 interval = (cycle_t) tmp;
257 tk->cycle_interval = interval;
258
259 /* Go back from cycles -> shifted ns */
260 tk->xtime_interval = (u64) interval * clock->mult;
261 tk->xtime_remainder = ntpinterval - tk->xtime_interval;
262 tk->raw_interval =
263 ((u64) interval * clock->mult) >> clock->shift;
264
265 /* if changing clocks, convert xtime_nsec shift units */
266 if (old_clock) {
267 int shift_change = clock->shift - old_clock->shift;
268 if (shift_change < 0)
269 tk->tkr_mono.xtime_nsec >>= -shift_change;
270 else
271 tk->tkr_mono.xtime_nsec <<= shift_change;
272 }
273 tk->tkr_raw.xtime_nsec = 0;
274
275 tk->tkr_mono.shift = clock->shift;
276 tk->tkr_raw.shift = clock->shift;
277
278 tk->ntp_error = 0;
279 tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
280 tk->ntp_tick = ntpinterval << tk->ntp_error_shift;
281
282 /*
283 * The timekeeper keeps its own mult values for the currently
284 * active clocksource. These value will be adjusted via NTP
285 * to counteract clock drifting.
286 */
287 tk->tkr_mono.mult = clock->mult;
288 tk->tkr_raw.mult = clock->mult;
289 tk->ntp_err_mult = 0;
290}
291
292/* Timekeeper helper functions. */
293
294#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
295static u32 default_arch_gettimeoffset(void) { return 0; }
296u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
297#else
298static inline u32 arch_gettimeoffset(void) { return 0; }
299#endif
300
301static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
302{
303 cycle_t delta;
304 s64 nsec;
305
306 delta = timekeeping_get_delta(tkr);
307
308 nsec = delta * tkr->mult + tkr->xtime_nsec;
309 nsec >>= tkr->shift;
310
311 /* If arch requires, add in get_arch_timeoffset() */
312 return nsec + arch_gettimeoffset();
313}
314
315/**
316 * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
317 * @tkr: Timekeeping readout base from which we take the update
318 *
319 * We want to use this from any context including NMI and tracing /
320 * instrumenting the timekeeping code itself.
321 *
322 * Employ the latch technique; see @raw_write_seqcount_latch.
323 *
324 * So if a NMI hits the update of base[0] then it will use base[1]
325 * which is still consistent. In the worst case this can result is a
326 * slightly wrong timestamp (a few nanoseconds). See
327 * @ktime_get_mono_fast_ns.
328 */
329static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf)
330{
331 struct tk_read_base *base = tkf->base;
332
333 /* Force readers off to base[1] */
334 raw_write_seqcount_latch(&tkf->seq);
335
336 /* Update base[0] */
337 memcpy(base, tkr, sizeof(*base));
338
339 /* Force readers back to base[0] */
340 raw_write_seqcount_latch(&tkf->seq);
341
342 /* Update base[1] */
343 memcpy(base + 1, base, sizeof(*base));
344}
345
346/**
347 * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic
348 *
349 * This timestamp is not guaranteed to be monotonic across an update.
350 * The timestamp is calculated by:
351 *
352 * now = base_mono + clock_delta * slope
353 *
354 * So if the update lowers the slope, readers who are forced to the
355 * not yet updated second array are still using the old steeper slope.
356 *
357 * tmono
358 * ^
359 * | o n
360 * | o n
361 * | u
362 * | o
363 * |o
364 * |12345678---> reader order
365 *
366 * o = old slope
367 * u = update
368 * n = new slope
369 *
370 * So reader 6 will observe time going backwards versus reader 5.
371 *
372 * While other CPUs are likely to be able observe that, the only way
373 * for a CPU local observation is when an NMI hits in the middle of
374 * the update. Timestamps taken from that NMI context might be ahead
375 * of the following timestamps. Callers need to be aware of that and
376 * deal with it.
377 */
378static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
379{
380 struct tk_read_base *tkr;
381 unsigned int seq;
382 u64 now;
383
384 do {
385 seq = raw_read_seqcount_latch(&tkf->seq);
386 tkr = tkf->base + (seq & 0x01);
387 now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr);
388 } while (read_seqcount_retry(&tkf->seq, seq));
389
390 return now;
391}
392
393u64 ktime_get_mono_fast_ns(void)
394{
395 return __ktime_get_fast_ns(&tk_fast_mono);
396}
397EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);
398
399u64 ktime_get_raw_fast_ns(void)
400{
401 return __ktime_get_fast_ns(&tk_fast_raw);
402}
403EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
404
405/* Suspend-time cycles value for halted fast timekeeper. */
406static cycle_t cycles_at_suspend;
407
408static cycle_t dummy_clock_read(struct clocksource *cs)
409{
410 return cycles_at_suspend;
411}
412
413/**
414 * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource.
415 * @tk: Timekeeper to snapshot.
416 *
417 * It generally is unsafe to access the clocksource after timekeeping has been
418 * suspended, so take a snapshot of the readout base of @tk and use it as the
419 * fast timekeeper's readout base while suspended. It will return the same
420 * number of cycles every time until timekeeping is resumed at which time the
421 * proper readout base for the fast timekeeper will be restored automatically.
422 */
423static void halt_fast_timekeeper(struct timekeeper *tk)
424{
425 static struct tk_read_base tkr_dummy;
426 struct tk_read_base *tkr = &tk->tkr_mono;
427
428 memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy));
429 cycles_at_suspend = tkr->read(tkr->clock);
430 tkr_dummy.read = dummy_clock_read;
431 update_fast_timekeeper(&tkr_dummy, &tk_fast_mono);
432
433 tkr = &tk->tkr_raw;
434 memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy));
435 tkr_dummy.read = dummy_clock_read;
436 update_fast_timekeeper(&tkr_dummy, &tk_fast_raw);
437}
438
439#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
440
441static inline void update_vsyscall(struct timekeeper *tk)
442{
443 struct timespec xt, wm;
444
445 xt = timespec64_to_timespec(tk_xtime(tk));
446 wm = timespec64_to_timespec(tk->wall_to_monotonic);
447 update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult,
448 tk->tkr_mono.cycle_last);
449}
450
451static inline void old_vsyscall_fixup(struct timekeeper *tk)
452{
453 s64 remainder;
454
455 /*
456 * Store only full nanoseconds into xtime_nsec after rounding
457 * it up and add the remainder to the error difference.
458 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
459 * by truncating the remainder in vsyscalls. However, it causes
460 * additional work to be done in timekeeping_adjust(). Once
461 * the vsyscall implementations are converted to use xtime_nsec
462 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
463 * users are removed, this can be killed.
464 */
465 remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1);
466 tk->tkr_mono.xtime_nsec -= remainder;
467 tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift;
468 tk->ntp_error += remainder << tk->ntp_error_shift;
469 tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift;
470}
471#else
472#define old_vsyscall_fixup(tk)
473#endif
474
475static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
476
477static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
478{
479 raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk);
480}
481
482/**
483 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
484 */
485int pvclock_gtod_register_notifier(struct notifier_block *nb)
486{
487 struct timekeeper *tk = &tk_core.timekeeper;
488 unsigned long flags;
489 int ret;
490
491 raw_spin_lock_irqsave(&timekeeper_lock, flags);
492 ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
493 update_pvclock_gtod(tk, true);
494 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
495
496 return ret;
497}
498EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
499
500/**
501 * pvclock_gtod_unregister_notifier - unregister a pvclock
502 * timedata update listener
503 */
504int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
505{
506 unsigned long flags;
507 int ret;
508
509 raw_spin_lock_irqsave(&timekeeper_lock, flags);
510 ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
511 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
512
513 return ret;
514}
515EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
516
517/*
518 * tk_update_leap_state - helper to update the next_leap_ktime
519 */
520static inline void tk_update_leap_state(struct timekeeper *tk)
521{
522 tk->next_leap_ktime = ntp_get_next_leap();
523 if (tk->next_leap_ktime.tv64 != KTIME_MAX)
524 /* Convert to monotonic time */
525 tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real);
526}
527
528/*
529 * Update the ktime_t based scalar nsec members of the timekeeper
530 */
531static inline void tk_update_ktime_data(struct timekeeper *tk)
532{
533 u64 seconds;
534 u32 nsec;
535
536 /*
537 * The xtime based monotonic readout is:
538 * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now();
539 * The ktime based monotonic readout is:
540 * nsec = base_mono + now();
541 * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec
542 */
543 seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
544 nsec = (u32) tk->wall_to_monotonic.tv_nsec;
545 tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
546
547 /* Update the monotonic raw base */
548 tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time);
549
550 /*
551 * The sum of the nanoseconds portions of xtime and
552 * wall_to_monotonic can be greater/equal one second. Take
553 * this into account before updating tk->ktime_sec.
554 */
555 nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
556 if (nsec >= NSEC_PER_SEC)
557 seconds++;
558 tk->ktime_sec = seconds;
559}
560
561/* must hold timekeeper_lock */
562static void timekeeping_update(struct timekeeper *tk, unsigned int action)
563{
564 if (action & TK_CLEAR_NTP) {
565 tk->ntp_error = 0;
566 ntp_clear();
567 }
568
569 tk_update_leap_state(tk);
570 tk_update_ktime_data(tk);
571
572 update_vsyscall(tk);
573 update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
574
575 update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
576 update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw);
577
578 if (action & TK_CLOCK_WAS_SET)
579 tk->clock_was_set_seq++;
580 /*
581 * The mirroring of the data to the shadow-timekeeper needs
582 * to happen last here to ensure we don't over-write the
583 * timekeeper structure on the next update with stale data
584 */
585 if (action & TK_MIRROR)
586 memcpy(&shadow_timekeeper, &tk_core.timekeeper,
587 sizeof(tk_core.timekeeper));
588}
589
590/**
591 * timekeeping_forward_now - update clock to the current time
592 *
593 * Forward the current clock to update its state since the last call to
594 * update_wall_time(). This is useful before significant clock changes,
595 * as it avoids having to deal with this time offset explicitly.
596 */
597static void timekeeping_forward_now(struct timekeeper *tk)
598{
599 struct clocksource *clock = tk->tkr_mono.clock;
600 cycle_t cycle_now, delta;
601 s64 nsec;
602
603 cycle_now = tk->tkr_mono.read(clock);
604 delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
605 tk->tkr_mono.cycle_last = cycle_now;
606 tk->tkr_raw.cycle_last = cycle_now;
607
608 tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult;
609
610 /* If arch requires, add in get_arch_timeoffset() */
611 tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
612
613 tk_normalize_xtime(tk);
614
615 nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift);
616 timespec64_add_ns(&tk->raw_time, nsec);
617}
618
619/**
620 * __getnstimeofday64 - Returns the time of day in a timespec64.
621 * @ts: pointer to the timespec to be set
622 *
623 * Updates the time of day in the timespec.
624 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
625 */
626int __getnstimeofday64(struct timespec64 *ts)
627{
628 struct timekeeper *tk = &tk_core.timekeeper;
629 unsigned long seq;
630 s64 nsecs = 0;
631
632 do {
633 seq = read_seqcount_begin(&tk_core.seq);
634
635 ts->tv_sec = tk->xtime_sec;
636 nsecs = timekeeping_get_ns(&tk->tkr_mono);
637
638 } while (read_seqcount_retry(&tk_core.seq, seq));
639
640 ts->tv_nsec = 0;
641 timespec64_add_ns(ts, nsecs);
642
643 /*
644 * Do not bail out early, in case there were callers still using
645 * the value, even in the face of the WARN_ON.
646 */
647 if (unlikely(timekeeping_suspended))
648 return -EAGAIN;
649 return 0;
650}
651EXPORT_SYMBOL(__getnstimeofday64);
652
653/**
654 * getnstimeofday64 - Returns the time of day in a timespec64.
655 * @ts: pointer to the timespec64 to be set
656 *
657 * Returns the time of day in a timespec64 (WARN if suspended).
658 */
659void getnstimeofday64(struct timespec64 *ts)
660{
661 WARN_ON(__getnstimeofday64(ts));
662}
663EXPORT_SYMBOL(getnstimeofday64);
664
665ktime_t ktime_get(void)
666{
667 struct timekeeper *tk = &tk_core.timekeeper;
668 unsigned int seq;
669 ktime_t base;
670 s64 nsecs;
671
672 WARN_ON(timekeeping_suspended);
673
674 do {
675 seq = read_seqcount_begin(&tk_core.seq);
676 base = tk->tkr_mono.base;
677 nsecs = timekeeping_get_ns(&tk->tkr_mono);
678
679 } while (read_seqcount_retry(&tk_core.seq, seq));
680
681 return ktime_add_ns(base, nsecs);
682}
683EXPORT_SYMBOL_GPL(ktime_get);
684
685u32 ktime_get_resolution_ns(void)
686{
687 struct timekeeper *tk = &tk_core.timekeeper;
688 unsigned int seq;
689 u32 nsecs;
690
691 WARN_ON(timekeeping_suspended);
692
693 do {
694 seq = read_seqcount_begin(&tk_core.seq);
695 nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift;
696 } while (read_seqcount_retry(&tk_core.seq, seq));
697
698 return nsecs;
699}
700EXPORT_SYMBOL_GPL(ktime_get_resolution_ns);
701
702static ktime_t *offsets[TK_OFFS_MAX] = {
703 [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
704 [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
705 [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
706};
707
708ktime_t ktime_get_with_offset(enum tk_offsets offs)
709{
710 struct timekeeper *tk = &tk_core.timekeeper;
711 unsigned int seq;
712 ktime_t base, *offset = offsets[offs];
713 s64 nsecs;
714
715 WARN_ON(timekeeping_suspended);
716
717 do {
718 seq = read_seqcount_begin(&tk_core.seq);
719 base = ktime_add(tk->tkr_mono.base, *offset);
720 nsecs = timekeeping_get_ns(&tk->tkr_mono);
721
722 } while (read_seqcount_retry(&tk_core.seq, seq));
723
724 return ktime_add_ns(base, nsecs);
725
726}
727EXPORT_SYMBOL_GPL(ktime_get_with_offset);
728
729/**
730 * ktime_mono_to_any() - convert mononotic time to any other time
731 * @tmono: time to convert.
732 * @offs: which offset to use
733 */
734ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
735{
736 ktime_t *offset = offsets[offs];
737 unsigned long seq;
738 ktime_t tconv;
739
740 do {
741 seq = read_seqcount_begin(&tk_core.seq);
742 tconv = ktime_add(tmono, *offset);
743 } while (read_seqcount_retry(&tk_core.seq, seq));
744
745 return tconv;
746}
747EXPORT_SYMBOL_GPL(ktime_mono_to_any);
748
749/**
750 * ktime_get_raw - Returns the raw monotonic time in ktime_t format
751 */
752ktime_t ktime_get_raw(void)
753{
754 struct timekeeper *tk = &tk_core.timekeeper;
755 unsigned int seq;
756 ktime_t base;
757 s64 nsecs;
758
759 do {
760 seq = read_seqcount_begin(&tk_core.seq);
761 base = tk->tkr_raw.base;
762 nsecs = timekeeping_get_ns(&tk->tkr_raw);
763
764 } while (read_seqcount_retry(&tk_core.seq, seq));
765
766 return ktime_add_ns(base, nsecs);
767}
768EXPORT_SYMBOL_GPL(ktime_get_raw);
769
770/**
771 * ktime_get_ts64 - get the monotonic clock in timespec64 format
772 * @ts: pointer to timespec variable
773 *
774 * The function calculates the monotonic clock from the realtime
775 * clock and the wall_to_monotonic offset and stores the result
776 * in normalized timespec64 format in the variable pointed to by @ts.
777 */
778void ktime_get_ts64(struct timespec64 *ts)
779{
780 struct timekeeper *tk = &tk_core.timekeeper;
781 struct timespec64 tomono;
782 s64 nsec;
783 unsigned int seq;
784
785 WARN_ON(timekeeping_suspended);
786
787 do {
788 seq = read_seqcount_begin(&tk_core.seq);
789 ts->tv_sec = tk->xtime_sec;
790 nsec = timekeeping_get_ns(&tk->tkr_mono);
791 tomono = tk->wall_to_monotonic;
792
793 } while (read_seqcount_retry(&tk_core.seq, seq));
794
795 ts->tv_sec += tomono.tv_sec;
796 ts->tv_nsec = 0;
797 timespec64_add_ns(ts, nsec + tomono.tv_nsec);
798}
799EXPORT_SYMBOL_GPL(ktime_get_ts64);
800
801/**
802 * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC
803 *
804 * Returns the seconds portion of CLOCK_MONOTONIC with a single non
805 * serialized read. tk->ktime_sec is of type 'unsigned long' so this
806 * works on both 32 and 64 bit systems. On 32 bit systems the readout
807 * covers ~136 years of uptime which should be enough to prevent
808 * premature wrap arounds.
809 */
810time64_t ktime_get_seconds(void)
811{
812 struct timekeeper *tk = &tk_core.timekeeper;
813
814 WARN_ON(timekeeping_suspended);
815 return tk->ktime_sec;
816}
817EXPORT_SYMBOL_GPL(ktime_get_seconds);
818
819/**
820 * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME
821 *
822 * Returns the wall clock seconds since 1970. This replaces the
823 * get_seconds() interface which is not y2038 safe on 32bit systems.
824 *
825 * For 64bit systems the fast access to tk->xtime_sec is preserved. On
826 * 32bit systems the access must be protected with the sequence
827 * counter to provide "atomic" access to the 64bit tk->xtime_sec
828 * value.
829 */
830time64_t ktime_get_real_seconds(void)
831{
832 struct timekeeper *tk = &tk_core.timekeeper;
833 time64_t seconds;
834 unsigned int seq;
835
836 if (IS_ENABLED(CONFIG_64BIT))
837 return tk->xtime_sec;
838
839 do {
840 seq = read_seqcount_begin(&tk_core.seq);
841 seconds = tk->xtime_sec;
842
843 } while (read_seqcount_retry(&tk_core.seq, seq));
844
845 return seconds;
846}
847EXPORT_SYMBOL_GPL(ktime_get_real_seconds);
848
849#ifdef CONFIG_NTP_PPS
850
851/**
852 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
853 * @ts_raw: pointer to the timespec to be set to raw monotonic time
854 * @ts_real: pointer to the timespec to be set to the time of day
855 *
856 * This function reads both the time of day and raw monotonic time at the
857 * same time atomically and stores the resulting timestamps in timespec
858 * format.
859 */
860void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
861{
862 struct timekeeper *tk = &tk_core.timekeeper;
863 unsigned long seq;
864 s64 nsecs_raw, nsecs_real;
865
866 WARN_ON_ONCE(timekeeping_suspended);
867
868 do {
869 seq = read_seqcount_begin(&tk_core.seq);
870
871 *ts_raw = timespec64_to_timespec(tk->raw_time);
872 ts_real->tv_sec = tk->xtime_sec;
873 ts_real->tv_nsec = 0;
874
875 nsecs_raw = timekeeping_get_ns(&tk->tkr_raw);
876 nsecs_real = timekeeping_get_ns(&tk->tkr_mono);
877
878 } while (read_seqcount_retry(&tk_core.seq, seq));
879
880 timespec_add_ns(ts_raw, nsecs_raw);
881 timespec_add_ns(ts_real, nsecs_real);
882}
883EXPORT_SYMBOL(getnstime_raw_and_real);
884
885#endif /* CONFIG_NTP_PPS */
886
887/**
888 * do_gettimeofday - Returns the time of day in a timeval
889 * @tv: pointer to the timeval to be set
890 *
891 * NOTE: Users should be converted to using getnstimeofday()
892 */
893void do_gettimeofday(struct timeval *tv)
894{
895 struct timespec64 now;
896
897 getnstimeofday64(&now);
898 tv->tv_sec = now.tv_sec;
899 tv->tv_usec = now.tv_nsec/1000;
900}
901EXPORT_SYMBOL(do_gettimeofday);
902
903/**
904 * do_settimeofday64 - Sets the time of day.
905 * @ts: pointer to the timespec64 variable containing the new time
906 *
907 * Sets the time of day to the new time and update NTP and notify hrtimers
908 */
909int do_settimeofday64(const struct timespec64 *ts)
910{
911 struct timekeeper *tk = &tk_core.timekeeper;
912 struct timespec64 ts_delta, xt;
913 unsigned long flags;
914
915 if (!timespec64_valid_strict(ts))
916 return -EINVAL;
917
918 raw_spin_lock_irqsave(&timekeeper_lock, flags);
919 write_seqcount_begin(&tk_core.seq);
920
921 timekeeping_forward_now(tk);
922
923 xt = tk_xtime(tk);
924 ts_delta.tv_sec = ts->tv_sec - xt.tv_sec;
925 ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec;
926
927 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta));
928
929 tk_set_xtime(tk, ts);
930
931 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
932
933 write_seqcount_end(&tk_core.seq);
934 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
935
936 /* signal hrtimers about time change */
937 clock_was_set();
938
939 return 0;
940}
941EXPORT_SYMBOL(do_settimeofday64);
942
943/**
944 * timekeeping_inject_offset - Adds or subtracts from the current time.
945 * @tv: pointer to the timespec variable containing the offset
946 *
947 * Adds or subtracts an offset value from the current time.
948 */
949int timekeeping_inject_offset(struct timespec *ts)
950{
951 struct timekeeper *tk = &tk_core.timekeeper;
952 unsigned long flags;
953 struct timespec64 ts64, tmp;
954 int ret = 0;
955
956 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
957 return -EINVAL;
958
959 ts64 = timespec_to_timespec64(*ts);
960
961 raw_spin_lock_irqsave(&timekeeper_lock, flags);
962 write_seqcount_begin(&tk_core.seq);
963
964 timekeeping_forward_now(tk);
965
966 /* Make sure the proposed value is valid */
967 tmp = timespec64_add(tk_xtime(tk), ts64);
968 if (!timespec64_valid_strict(&tmp)) {
969 ret = -EINVAL;
970 goto error;
971 }
972
973 tk_xtime_add(tk, &ts64);
974 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64));
975
976error: /* even if we error out, we forwarded the time, so call update */
977 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
978
979 write_seqcount_end(&tk_core.seq);
980 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
981
982 /* signal hrtimers about time change */
983 clock_was_set();
984
985 return ret;
986}
987EXPORT_SYMBOL(timekeeping_inject_offset);
988
989
990/**
991 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
992 *
993 */
994s32 timekeeping_get_tai_offset(void)
995{
996 struct timekeeper *tk = &tk_core.timekeeper;
997 unsigned int seq;
998 s32 ret;
999
1000 do {
1001 seq = read_seqcount_begin(&tk_core.seq);
1002 ret = tk->tai_offset;
1003 } while (read_seqcount_retry(&tk_core.seq, seq));
1004
1005 return ret;
1006}
1007
1008/**
1009 * __timekeeping_set_tai_offset - Lock free worker function
1010 *
1011 */
1012static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
1013{
1014 tk->tai_offset = tai_offset;
1015 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
1016}
1017
1018/**
1019 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
1020 *
1021 */
1022void timekeeping_set_tai_offset(s32 tai_offset)
1023{
1024 struct timekeeper *tk = &tk_core.timekeeper;
1025 unsigned long flags;
1026
1027 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1028 write_seqcount_begin(&tk_core.seq);
1029 __timekeeping_set_tai_offset(tk, tai_offset);
1030 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1031 write_seqcount_end(&tk_core.seq);
1032 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1033 clock_was_set();
1034}
1035
1036/**
1037 * change_clocksource - Swaps clocksources if a new one is available
1038 *
1039 * Accumulates current time interval and initializes new clocksource
1040 */
1041static int change_clocksource(void *data)
1042{
1043 struct timekeeper *tk = &tk_core.timekeeper;
1044 struct clocksource *new, *old;
1045 unsigned long flags;
1046
1047 new = (struct clocksource *) data;
1048
1049 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1050 write_seqcount_begin(&tk_core.seq);
1051
1052 timekeeping_forward_now(tk);
1053 /*
1054 * If the cs is in module, get a module reference. Succeeds
1055 * for built-in code (owner == NULL) as well.
1056 */
1057 if (try_module_get(new->owner)) {
1058 if (!new->enable || new->enable(new) == 0) {
1059 old = tk->tkr_mono.clock;
1060 tk_setup_internals(tk, new);
1061 if (old->disable)
1062 old->disable(old);
1063 module_put(old->owner);
1064 } else {
1065 module_put(new->owner);
1066 }
1067 }
1068 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1069
1070 write_seqcount_end(&tk_core.seq);
1071 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1072
1073 return 0;
1074}
1075
1076/**
1077 * timekeeping_notify - Install a new clock source
1078 * @clock: pointer to the clock source
1079 *
1080 * This function is called from clocksource.c after a new, better clock
1081 * source has been registered. The caller holds the clocksource_mutex.
1082 */
1083int timekeeping_notify(struct clocksource *clock)
1084{
1085 struct timekeeper *tk = &tk_core.timekeeper;
1086
1087 if (tk->tkr_mono.clock == clock)
1088 return 0;
1089 stop_machine(change_clocksource, clock, NULL);
1090 tick_clock_notify();
1091 return tk->tkr_mono.clock == clock ? 0 : -1;
1092}
1093
1094/**
1095 * getrawmonotonic64 - Returns the raw monotonic time in a timespec
1096 * @ts: pointer to the timespec64 to be set
1097 *
1098 * Returns the raw monotonic time (completely un-modified by ntp)
1099 */
1100void getrawmonotonic64(struct timespec64 *ts)
1101{
1102 struct timekeeper *tk = &tk_core.timekeeper;
1103 struct timespec64 ts64;
1104 unsigned long seq;
1105 s64 nsecs;
1106
1107 do {
1108 seq = read_seqcount_begin(&tk_core.seq);
1109 nsecs = timekeeping_get_ns(&tk->tkr_raw);
1110 ts64 = tk->raw_time;
1111
1112 } while (read_seqcount_retry(&tk_core.seq, seq));
1113
1114 timespec64_add_ns(&ts64, nsecs);
1115 *ts = ts64;
1116}
1117EXPORT_SYMBOL(getrawmonotonic64);
1118
1119
1120/**
1121 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
1122 */
1123int timekeeping_valid_for_hres(void)
1124{
1125 struct timekeeper *tk = &tk_core.timekeeper;
1126 unsigned long seq;
1127 int ret;
1128
1129 do {
1130 seq = read_seqcount_begin(&tk_core.seq);
1131
1132 ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
1133
1134 } while (read_seqcount_retry(&tk_core.seq, seq));
1135
1136 return ret;
1137}
1138
1139/**
1140 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
1141 */
1142u64 timekeeping_max_deferment(void)
1143{
1144 struct timekeeper *tk = &tk_core.timekeeper;
1145 unsigned long seq;
1146 u64 ret;
1147
1148 do {
1149 seq = read_seqcount_begin(&tk_core.seq);
1150
1151 ret = tk->tkr_mono.clock->max_idle_ns;
1152
1153 } while (read_seqcount_retry(&tk_core.seq, seq));
1154
1155 return ret;
1156}
1157
1158/**
1159 * read_persistent_clock - Return time from the persistent clock.
1160 *
1161 * Weak dummy function for arches that do not yet support it.
1162 * Reads the time from the battery backed persistent clock.
1163 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
1164 *
1165 * XXX - Do be sure to remove it once all arches implement it.
1166 */
1167void __weak read_persistent_clock(struct timespec *ts)
1168{
1169 ts->tv_sec = 0;
1170 ts->tv_nsec = 0;
1171}
1172
1173void __weak read_persistent_clock64(struct timespec64 *ts64)
1174{
1175 struct timespec ts;
1176
1177 read_persistent_clock(&ts);
1178 *ts64 = timespec_to_timespec64(ts);
1179}
1180
1181/**
1182 * read_boot_clock64 - Return time of the system start.
1183 *
1184 * Weak dummy function for arches that do not yet support it.
1185 * Function to read the exact time the system has been started.
1186 * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported.
1187 *
1188 * XXX - Do be sure to remove it once all arches implement it.
1189 */
1190void __weak read_boot_clock64(struct timespec64 *ts)
1191{
1192 ts->tv_sec = 0;
1193 ts->tv_nsec = 0;
1194}
1195
1196/* Flag for if timekeeping_resume() has injected sleeptime */
1197static bool sleeptime_injected;
1198
1199/* Flag for if there is a persistent clock on this platform */
1200static bool persistent_clock_exists;
1201
1202/*
1203 * timekeeping_init - Initializes the clocksource and common timekeeping values
1204 */
1205void __init timekeeping_init(void)
1206{
1207 struct timekeeper *tk = &tk_core.timekeeper;
1208 struct clocksource *clock;
1209 unsigned long flags;
1210 struct timespec64 now, boot, tmp;
1211
1212 read_persistent_clock64(&now);
1213 if (!timespec64_valid_strict(&now)) {
1214 pr_warn("WARNING: Persistent clock returned invalid value!\n"
1215 " Check your CMOS/BIOS settings.\n");
1216 now.tv_sec = 0;
1217 now.tv_nsec = 0;
1218 } else if (now.tv_sec || now.tv_nsec)
1219 persistent_clock_exists = true;
1220
1221 read_boot_clock64(&boot);
1222 if (!timespec64_valid_strict(&boot)) {
1223 pr_warn("WARNING: Boot clock returned invalid value!\n"
1224 " Check your CMOS/BIOS settings.\n");
1225 boot.tv_sec = 0;
1226 boot.tv_nsec = 0;
1227 }
1228
1229 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1230 write_seqcount_begin(&tk_core.seq);
1231 ntp_init();
1232
1233 clock = clocksource_default_clock();
1234 if (clock->enable)
1235 clock->enable(clock);
1236 tk_setup_internals(tk, clock);
1237
1238 tk_set_xtime(tk, &now);
1239 tk->raw_time.tv_sec = 0;
1240 tk->raw_time.tv_nsec = 0;
1241 if (boot.tv_sec == 0 && boot.tv_nsec == 0)
1242 boot = tk_xtime(tk);
1243
1244 set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec);
1245 tk_set_wall_to_mono(tk, tmp);
1246
1247 timekeeping_update(tk, TK_MIRROR);
1248
1249 write_seqcount_end(&tk_core.seq);
1250 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1251}
1252
1253/* time in seconds when suspend began for persistent clock */
1254static struct timespec64 timekeeping_suspend_time;
1255
1256/**
1257 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
1258 * @delta: pointer to a timespec delta value
1259 *
1260 * Takes a timespec offset measuring a suspend interval and properly
1261 * adds the sleep offset to the timekeeping variables.
1262 */
1263static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
1264 struct timespec64 *delta)
1265{
1266 if (!timespec64_valid_strict(delta)) {
1267 printk_deferred(KERN_WARNING
1268 "__timekeeping_inject_sleeptime: Invalid "
1269 "sleep delta value!\n");
1270 return;
1271 }
1272 tk_xtime_add(tk, delta);
1273 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
1274 tk_update_sleep_time(tk, timespec64_to_ktime(*delta));
1275 tk_debug_account_sleep_time(delta);
1276}
1277
1278#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
1279/**
1280 * We have three kinds of time sources to use for sleep time
1281 * injection, the preference order is:
1282 * 1) non-stop clocksource
1283 * 2) persistent clock (ie: RTC accessible when irqs are off)
1284 * 3) RTC
1285 *
1286 * 1) and 2) are used by timekeeping, 3) by RTC subsystem.
1287 * If system has neither 1) nor 2), 3) will be used finally.
1288 *
1289 *
1290 * If timekeeping has injected sleeptime via either 1) or 2),
1291 * 3) becomes needless, so in this case we don't need to call
1292 * rtc_resume(), and this is what timekeeping_rtc_skipresume()
1293 * means.
1294 */
1295bool timekeeping_rtc_skipresume(void)
1296{
1297 return sleeptime_injected;
1298}
1299
1300/**
1301 * 1) can be determined whether to use or not only when doing
1302 * timekeeping_resume() which is invoked after rtc_suspend(),
1303 * so we can't skip rtc_suspend() surely if system has 1).
1304 *
1305 * But if system has 2), 2) will definitely be used, so in this
1306 * case we don't need to call rtc_suspend(), and this is what
1307 * timekeeping_rtc_skipsuspend() means.
1308 */
1309bool timekeeping_rtc_skipsuspend(void)
1310{
1311 return persistent_clock_exists;
1312}
1313
1314/**
1315 * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values
1316 * @delta: pointer to a timespec64 delta value
1317 *
1318 * This hook is for architectures that cannot support read_persistent_clock64
1319 * because their RTC/persistent clock is only accessible when irqs are enabled.
1320 * and also don't have an effective nonstop clocksource.
1321 *
1322 * This function should only be called by rtc_resume(), and allows
1323 * a suspend offset to be injected into the timekeeping values.
1324 */
1325void timekeeping_inject_sleeptime64(struct timespec64 *delta)
1326{
1327 struct timekeeper *tk = &tk_core.timekeeper;
1328 unsigned long flags;
1329
1330 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1331 write_seqcount_begin(&tk_core.seq);
1332
1333 timekeeping_forward_now(tk);
1334
1335 __timekeeping_inject_sleeptime(tk, delta);
1336
1337 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
1338
1339 write_seqcount_end(&tk_core.seq);
1340 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1341
1342 /* signal hrtimers about time change */
1343 clock_was_set();
1344}
1345#endif
1346
1347/**
1348 * timekeeping_resume - Resumes the generic timekeeping subsystem.
1349 */
1350void timekeeping_resume(void)
1351{
1352 struct timekeeper *tk = &tk_core.timekeeper;
1353 struct clocksource *clock = tk->tkr_mono.clock;
1354 unsigned long flags;
1355 struct timespec64 ts_new, ts_delta;
1356 cycle_t cycle_now, cycle_delta;
1357
1358 sleeptime_injected = false;
1359 read_persistent_clock64(&ts_new);
1360
1361 clockevents_resume();
1362 clocksource_resume();
1363
1364 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1365 write_seqcount_begin(&tk_core.seq);
1366
1367 /*
1368 * After system resumes, we need to calculate the suspended time and
1369 * compensate it for the OS time. There are 3 sources that could be
1370 * used: Nonstop clocksource during suspend, persistent clock and rtc
1371 * device.
1372 *
1373 * One specific platform may have 1 or 2 or all of them, and the
1374 * preference will be:
1375 * suspend-nonstop clocksource -> persistent clock -> rtc
1376 * The less preferred source will only be tried if there is no better
1377 * usable source. The rtc part is handled separately in rtc core code.
1378 */
1379 cycle_now = tk->tkr_mono.read(clock);
1380 if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
1381 cycle_now > tk->tkr_mono.cycle_last) {
1382 u64 num, max = ULLONG_MAX;
1383 u32 mult = clock->mult;
1384 u32 shift = clock->shift;
1385 s64 nsec = 0;
1386
1387 cycle_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last,
1388 tk->tkr_mono.mask);
1389
1390 /*
1391 * "cycle_delta * mutl" may cause 64 bits overflow, if the
1392 * suspended time is too long. In that case we need do the
1393 * 64 bits math carefully
1394 */
1395 do_div(max, mult);
1396 if (cycle_delta > max) {
1397 num = div64_u64(cycle_delta, max);
1398 nsec = (((u64) max * mult) >> shift) * num;
1399 cycle_delta -= num * max;
1400 }
1401 nsec += ((u64) cycle_delta * mult) >> shift;
1402
1403 ts_delta = ns_to_timespec64(nsec);
1404 sleeptime_injected = true;
1405 } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
1406 ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time);
1407 sleeptime_injected = true;
1408 }
1409
1410 if (sleeptime_injected)
1411 __timekeeping_inject_sleeptime(tk, &ts_delta);
1412
1413 /* Re-base the last cycle value */
1414 tk->tkr_mono.cycle_last = cycle_now;
1415 tk->tkr_raw.cycle_last = cycle_now;
1416
1417 tk->ntp_error = 0;
1418 timekeeping_suspended = 0;
1419 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
1420 write_seqcount_end(&tk_core.seq);
1421 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1422
1423 touch_softlockup_watchdog();
1424
1425 tick_resume();
1426 hrtimers_resume();
1427}
1428
1429int timekeeping_suspend(void)
1430{
1431 struct timekeeper *tk = &tk_core.timekeeper;
1432 unsigned long flags;
1433 struct timespec64 delta, delta_delta;
1434 static struct timespec64 old_delta;
1435
1436 read_persistent_clock64(&timekeeping_suspend_time);
1437
1438 /*
1439 * On some systems the persistent_clock can not be detected at
1440 * timekeeping_init by its return value, so if we see a valid
1441 * value returned, update the persistent_clock_exists flag.
1442 */
1443 if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec)
1444 persistent_clock_exists = true;
1445
1446 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1447 write_seqcount_begin(&tk_core.seq);
1448 timekeeping_forward_now(tk);
1449 timekeeping_suspended = 1;
1450
1451 if (persistent_clock_exists) {
1452 /*
1453 * To avoid drift caused by repeated suspend/resumes,
1454 * which each can add ~1 second drift error,
1455 * try to compensate so the difference in system time
1456 * and persistent_clock time stays close to constant.
1457 */
1458 delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time);
1459 delta_delta = timespec64_sub(delta, old_delta);
1460 if (abs(delta_delta.tv_sec) >= 2) {
1461 /*
1462 * if delta_delta is too large, assume time correction
1463 * has occurred and set old_delta to the current delta.
1464 */
1465 old_delta = delta;
1466 } else {
1467 /* Otherwise try to adjust old_system to compensate */
1468 timekeeping_suspend_time =
1469 timespec64_add(timekeeping_suspend_time, delta_delta);
1470 }
1471 }
1472
1473 timekeeping_update(tk, TK_MIRROR);
1474 halt_fast_timekeeper(tk);
1475 write_seqcount_end(&tk_core.seq);
1476 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1477
1478 tick_suspend();
1479 clocksource_suspend();
1480 clockevents_suspend();
1481
1482 return 0;
1483}
1484
1485/* sysfs resume/suspend bits for timekeeping */
1486static struct syscore_ops timekeeping_syscore_ops = {
1487 .resume = timekeeping_resume,
1488 .suspend = timekeeping_suspend,
1489};
1490
1491static int __init timekeeping_init_ops(void)
1492{
1493 register_syscore_ops(&timekeeping_syscore_ops);
1494 return 0;
1495}
1496device_initcall(timekeeping_init_ops);
1497
1498/*
1499 * Apply a multiplier adjustment to the timekeeper
1500 */
1501static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk,
1502 s64 offset,
1503 bool negative,
1504 int adj_scale)
1505{
1506 s64 interval = tk->cycle_interval;
1507 s32 mult_adj = 1;
1508
1509 if (negative) {
1510 mult_adj = -mult_adj;
1511 interval = -interval;
1512 offset = -offset;
1513 }
1514 mult_adj <<= adj_scale;
1515 interval <<= adj_scale;
1516 offset <<= adj_scale;
1517
1518 /*
1519 * So the following can be confusing.
1520 *
1521 * To keep things simple, lets assume mult_adj == 1 for now.
1522 *
1523 * When mult_adj != 1, remember that the interval and offset values
1524 * have been appropriately scaled so the math is the same.
1525 *
1526 * The basic idea here is that we're increasing the multiplier
1527 * by one, this causes the xtime_interval to be incremented by
1528 * one cycle_interval. This is because:
1529 * xtime_interval = cycle_interval * mult
1530 * So if mult is being incremented by one:
1531 * xtime_interval = cycle_interval * (mult + 1)
1532 * Its the same as:
1533 * xtime_interval = (cycle_interval * mult) + cycle_interval
1534 * Which can be shortened to:
1535 * xtime_interval += cycle_interval
1536 *
1537 * So offset stores the non-accumulated cycles. Thus the current
1538 * time (in shifted nanoseconds) is:
1539 * now = (offset * adj) + xtime_nsec
1540 * Now, even though we're adjusting the clock frequency, we have
1541 * to keep time consistent. In other words, we can't jump back
1542 * in time, and we also want to avoid jumping forward in time.
1543 *
1544 * So given the same offset value, we need the time to be the same
1545 * both before and after the freq adjustment.
1546 * now = (offset * adj_1) + xtime_nsec_1
1547 * now = (offset * adj_2) + xtime_nsec_2
1548 * So:
1549 * (offset * adj_1) + xtime_nsec_1 =
1550 * (offset * adj_2) + xtime_nsec_2
1551 * And we know:
1552 * adj_2 = adj_1 + 1
1553 * So:
1554 * (offset * adj_1) + xtime_nsec_1 =
1555 * (offset * (adj_1+1)) + xtime_nsec_2
1556 * (offset * adj_1) + xtime_nsec_1 =
1557 * (offset * adj_1) + offset + xtime_nsec_2
1558 * Canceling the sides:
1559 * xtime_nsec_1 = offset + xtime_nsec_2
1560 * Which gives us:
1561 * xtime_nsec_2 = xtime_nsec_1 - offset
1562 * Which simplfies to:
1563 * xtime_nsec -= offset
1564 *
1565 * XXX - TODO: Doc ntp_error calculation.
1566 */
1567 if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) {
1568 /* NTP adjustment caused clocksource mult overflow */
1569 WARN_ON_ONCE(1);
1570 return;
1571 }
1572
1573 tk->tkr_mono.mult += mult_adj;
1574 tk->xtime_interval += interval;
1575 tk->tkr_mono.xtime_nsec -= offset;
1576 tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
1577}
1578
1579/*
1580 * Calculate the multiplier adjustment needed to match the frequency
1581 * specified by NTP
1582 */
1583static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
1584 s64 offset)
1585{
1586 s64 interval = tk->cycle_interval;
1587 s64 xinterval = tk->xtime_interval;
1588 s64 tick_error;
1589 bool negative;
1590 u32 adj;
1591
1592 /* Remove any current error adj from freq calculation */
1593 if (tk->ntp_err_mult)
1594 xinterval -= tk->cycle_interval;
1595
1596 tk->ntp_tick = ntp_tick_length();
1597
1598 /* Calculate current error per tick */
1599 tick_error = ntp_tick_length() >> tk->ntp_error_shift;
1600 tick_error -= (xinterval + tk->xtime_remainder);
1601
1602 /* Don't worry about correcting it if its small */
1603 if (likely((tick_error >= 0) && (tick_error <= interval)))
1604 return;
1605
1606 /* preserve the direction of correction */
1607 negative = (tick_error < 0);
1608
1609 /* Sort out the magnitude of the correction */
1610 tick_error = abs(tick_error);
1611 for (adj = 0; tick_error > interval; adj++)
1612 tick_error >>= 1;
1613
1614 /* scale the corrections */
1615 timekeeping_apply_adjustment(tk, offset, negative, adj);
1616}
1617
1618/*
1619 * Adjust the timekeeper's multiplier to the correct frequency
1620 * and also to reduce the accumulated error value.
1621 */
1622static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
1623{
1624 /* Correct for the current frequency error */
1625 timekeeping_freqadjust(tk, offset);
1626
1627 /* Next make a small adjustment to fix any cumulative error */
1628 if (!tk->ntp_err_mult && (tk->ntp_error > 0)) {
1629 tk->ntp_err_mult = 1;
1630 timekeeping_apply_adjustment(tk, offset, 0, 0);
1631 } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) {
1632 /* Undo any existing error adjustment */
1633 timekeeping_apply_adjustment(tk, offset, 1, 0);
1634 tk->ntp_err_mult = 0;
1635 }
1636
1637 if (unlikely(tk->tkr_mono.clock->maxadj &&
1638 (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult)
1639 > tk->tkr_mono.clock->maxadj))) {
1640 printk_once(KERN_WARNING
1641 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1642 tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult,
1643 (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj);
1644 }
1645
1646 /*
1647 * It may be possible that when we entered this function, xtime_nsec
1648 * was very small. Further, if we're slightly speeding the clocksource
1649 * in the code above, its possible the required corrective factor to
1650 * xtime_nsec could cause it to underflow.
1651 *
1652 * Now, since we already accumulated the second, cannot simply roll
1653 * the accumulated second back, since the NTP subsystem has been
1654 * notified via second_overflow. So instead we push xtime_nsec forward
1655 * by the amount we underflowed, and add that amount into the error.
1656 *
1657 * We'll correct this error next time through this function, when
1658 * xtime_nsec is not as small.
1659 */
1660 if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) {
1661 s64 neg = -(s64)tk->tkr_mono.xtime_nsec;
1662 tk->tkr_mono.xtime_nsec = 0;
1663 tk->ntp_error += neg << tk->ntp_error_shift;
1664 }
1665}
1666
1667/**
1668 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1669 *
1670 * Helper function that accumulates a the nsecs greater then a second
1671 * from the xtime_nsec field to the xtime_secs field.
1672 * It also calls into the NTP code to handle leapsecond processing.
1673 *
1674 */
1675static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
1676{
1677 u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
1678 unsigned int clock_set = 0;
1679
1680 while (tk->tkr_mono.xtime_nsec >= nsecps) {
1681 int leap;
1682
1683 tk->tkr_mono.xtime_nsec -= nsecps;
1684 tk->xtime_sec++;
1685
1686 /* Figure out if its a leap sec and apply if needed */
1687 leap = second_overflow(tk->xtime_sec);
1688 if (unlikely(leap)) {
1689 struct timespec64 ts;
1690
1691 tk->xtime_sec += leap;
1692
1693 ts.tv_sec = leap;
1694 ts.tv_nsec = 0;
1695 tk_set_wall_to_mono(tk,
1696 timespec64_sub(tk->wall_to_monotonic, ts));
1697
1698 __timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
1699
1700 clock_set = TK_CLOCK_WAS_SET;
1701 }
1702 }
1703 return clock_set;
1704}
1705
1706/**
1707 * logarithmic_accumulation - shifted accumulation of cycles
1708 *
1709 * This functions accumulates a shifted interval of cycles into
1710 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1711 * loop.
1712 *
1713 * Returns the unconsumed cycles.
1714 */
1715static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
1716 u32 shift,
1717 unsigned int *clock_set)
1718{
1719 cycle_t interval = tk->cycle_interval << shift;
1720 u64 raw_nsecs;
1721
1722 /* If the offset is smaller then a shifted interval, do nothing */
1723 if (offset < interval)
1724 return offset;
1725
1726 /* Accumulate one shifted interval */
1727 offset -= interval;
1728 tk->tkr_mono.cycle_last += interval;
1729 tk->tkr_raw.cycle_last += interval;
1730
1731 tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift;
1732 *clock_set |= accumulate_nsecs_to_secs(tk);
1733
1734 /* Accumulate raw time */
1735 raw_nsecs = (u64)tk->raw_interval << shift;
1736 raw_nsecs += tk->raw_time.tv_nsec;
1737 if (raw_nsecs >= NSEC_PER_SEC) {
1738 u64 raw_secs = raw_nsecs;
1739 raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
1740 tk->raw_time.tv_sec += raw_secs;
1741 }
1742 tk->raw_time.tv_nsec = raw_nsecs;
1743
1744 /* Accumulate error between NTP and clock interval */
1745 tk->ntp_error += tk->ntp_tick << shift;
1746 tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
1747 (tk->ntp_error_shift + shift);
1748
1749 return offset;
1750}
1751
1752/**
1753 * update_wall_time - Uses the current clocksource to increment the wall time
1754 *
1755 */
1756void update_wall_time(void)
1757{
1758 struct timekeeper *real_tk = &tk_core.timekeeper;
1759 struct timekeeper *tk = &shadow_timekeeper;
1760 cycle_t offset;
1761 int shift = 0, maxshift;
1762 unsigned int clock_set = 0;
1763 unsigned long flags;
1764
1765 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1766
1767 /* Make sure we're fully resumed: */
1768 if (unlikely(timekeeping_suspended))
1769 goto out;
1770
1771#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
1772 offset = real_tk->cycle_interval;
1773#else
1774 offset = clocksource_delta(tk->tkr_mono.read(tk->tkr_mono.clock),
1775 tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
1776#endif
1777
1778 /* Check if there's really nothing to do */
1779 if (offset < real_tk->cycle_interval)
1780 goto out;
1781
1782 /* Do some additional sanity checking */
1783 timekeeping_check_update(real_tk, offset);
1784
1785 /*
1786 * With NO_HZ we may have to accumulate many cycle_intervals
1787 * (think "ticks") worth of time at once. To do this efficiently,
1788 * we calculate the largest doubling multiple of cycle_intervals
1789 * that is smaller than the offset. We then accumulate that
1790 * chunk in one go, and then try to consume the next smaller
1791 * doubled multiple.
1792 */
1793 shift = ilog2(offset) - ilog2(tk->cycle_interval);
1794 shift = max(0, shift);
1795 /* Bound shift to one less than what overflows tick_length */
1796 maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
1797 shift = min(shift, maxshift);
1798 while (offset >= tk->cycle_interval) {
1799 offset = logarithmic_accumulation(tk, offset, shift,
1800 &clock_set);
1801 if (offset < tk->cycle_interval<<shift)
1802 shift--;
1803 }
1804
1805 /* correct the clock when NTP error is too big */
1806 timekeeping_adjust(tk, offset);
1807
1808 /*
1809 * XXX This can be killed once everyone converts
1810 * to the new update_vsyscall.
1811 */
1812 old_vsyscall_fixup(tk);
1813
1814 /*
1815 * Finally, make sure that after the rounding
1816 * xtime_nsec isn't larger than NSEC_PER_SEC
1817 */
1818 clock_set |= accumulate_nsecs_to_secs(tk);
1819
1820 write_seqcount_begin(&tk_core.seq);
1821 /*
1822 * Update the real timekeeper.
1823 *
1824 * We could avoid this memcpy by switching pointers, but that
1825 * requires changes to all other timekeeper usage sites as
1826 * well, i.e. move the timekeeper pointer getter into the
1827 * spinlocked/seqcount protected sections. And we trade this
1828 * memcpy under the tk_core.seq against one before we start
1829 * updating.
1830 */
1831 timekeeping_update(tk, clock_set);
1832 memcpy(real_tk, tk, sizeof(*tk));
1833 /* The memcpy must come last. Do not put anything here! */
1834 write_seqcount_end(&tk_core.seq);
1835out:
1836 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1837 if (clock_set)
1838 /* Have to call _delayed version, since in irq context*/
1839 clock_was_set_delayed();
1840}
1841
1842/**
1843 * getboottime64 - Return the real time of system boot.
1844 * @ts: pointer to the timespec64 to be set
1845 *
1846 * Returns the wall-time of boot in a timespec64.
1847 *
1848 * This is based on the wall_to_monotonic offset and the total suspend
1849 * time. Calls to settimeofday will affect the value returned (which
1850 * basically means that however wrong your real time clock is at boot time,
1851 * you get the right time here).
1852 */
1853void getboottime64(struct timespec64 *ts)
1854{
1855 struct timekeeper *tk = &tk_core.timekeeper;
1856 ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
1857
1858 *ts = ktime_to_timespec64(t);
1859}
1860EXPORT_SYMBOL_GPL(getboottime64);
1861
1862unsigned long get_seconds(void)
1863{
1864 struct timekeeper *tk = &tk_core.timekeeper;
1865
1866 return tk->xtime_sec;
1867}
1868EXPORT_SYMBOL(get_seconds);
1869
1870struct timespec __current_kernel_time(void)
1871{
1872 struct timekeeper *tk = &tk_core.timekeeper;
1873
1874 return timespec64_to_timespec(tk_xtime(tk));
1875}
1876
1877struct timespec current_kernel_time(void)
1878{
1879 struct timekeeper *tk = &tk_core.timekeeper;
1880 struct timespec64 now;
1881 unsigned long seq;
1882
1883 do {
1884 seq = read_seqcount_begin(&tk_core.seq);
1885
1886 now = tk_xtime(tk);
1887 } while (read_seqcount_retry(&tk_core.seq, seq));
1888
1889 return timespec64_to_timespec(now);
1890}
1891EXPORT_SYMBOL(current_kernel_time);
1892
1893struct timespec64 get_monotonic_coarse64(void)
1894{
1895 struct timekeeper *tk = &tk_core.timekeeper;
1896 struct timespec64 now, mono;
1897 unsigned long seq;
1898
1899 do {
1900 seq = read_seqcount_begin(&tk_core.seq);
1901
1902 now = tk_xtime(tk);
1903 mono = tk->wall_to_monotonic;
1904 } while (read_seqcount_retry(&tk_core.seq, seq));
1905
1906 set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
1907 now.tv_nsec + mono.tv_nsec);
1908
1909 return now;
1910}
1911
1912/*
1913 * Must hold jiffies_lock
1914 */
1915void do_timer(unsigned long ticks)
1916{
1917 jiffies_64 += ticks;
1918 calc_global_load(ticks);
1919}
1920
1921/**
1922 * ktime_get_update_offsets_now - hrtimer helper
1923 * @cwsseq: pointer to check and store the clock was set sequence number
1924 * @offs_real: pointer to storage for monotonic -> realtime offset
1925 * @offs_boot: pointer to storage for monotonic -> boottime offset
1926 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1927 *
1928 * Returns current monotonic time and updates the offsets if the
1929 * sequence number in @cwsseq and timekeeper.clock_was_set_seq are
1930 * different.
1931 *
1932 * Called from hrtimer_interrupt() or retrigger_next_event()
1933 */
1934ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
1935 ktime_t *offs_boot, ktime_t *offs_tai)
1936{
1937 struct timekeeper *tk = &tk_core.timekeeper;
1938 unsigned int seq;
1939 ktime_t base;
1940 u64 nsecs;
1941
1942 do {
1943 seq = read_seqcount_begin(&tk_core.seq);
1944
1945 base = tk->tkr_mono.base;
1946 nsecs = timekeeping_get_ns(&tk->tkr_mono);
1947 base = ktime_add_ns(base, nsecs);
1948
1949 if (*cwsseq != tk->clock_was_set_seq) {
1950 *cwsseq = tk->clock_was_set_seq;
1951 *offs_real = tk->offs_real;
1952 *offs_boot = tk->offs_boot;
1953 *offs_tai = tk->offs_tai;
1954 }
1955
1956 /* Handle leapsecond insertion adjustments */
1957 if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64))
1958 *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0));
1959
1960 } while (read_seqcount_retry(&tk_core.seq, seq));
1961
1962 return base;
1963}
1964
1965/**
1966 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1967 */
1968int do_adjtimex(struct timex *txc)
1969{
1970 struct timekeeper *tk = &tk_core.timekeeper;
1971 unsigned long flags;
1972 struct timespec64 ts;
1973 s32 orig_tai, tai;
1974 int ret;
1975
1976 /* Validate the data before disabling interrupts */
1977 ret = ntp_validate_timex(txc);
1978 if (ret)
1979 return ret;
1980
1981 if (txc->modes & ADJ_SETOFFSET) {
1982 struct timespec delta;
1983 delta.tv_sec = txc->time.tv_sec;
1984 delta.tv_nsec = txc->time.tv_usec;
1985 if (!(txc->modes & ADJ_NANO))
1986 delta.tv_nsec *= 1000;
1987 ret = timekeeping_inject_offset(&delta);
1988 if (ret)
1989 return ret;
1990 }
1991
1992 getnstimeofday64(&ts);
1993
1994 raw_spin_lock_irqsave(&timekeeper_lock, flags);
1995 write_seqcount_begin(&tk_core.seq);
1996
1997 orig_tai = tai = tk->tai_offset;
1998 ret = __do_adjtimex(txc, &ts, &tai);
1999
2000 if (tai != orig_tai) {
2001 __timekeeping_set_tai_offset(tk, tai);
2002 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
2003 }
2004 tk_update_leap_state(tk);
2005
2006 write_seqcount_end(&tk_core.seq);
2007 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2008
2009 if (tai != orig_tai)
2010 clock_was_set();
2011
2012 ntp_notify_cmos_timer();
2013
2014 return ret;
2015}
2016
2017#ifdef CONFIG_NTP_PPS
2018/**
2019 * hardpps() - Accessor function to NTP __hardpps function
2020 */
2021void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
2022{
2023 unsigned long flags;
2024
2025 raw_spin_lock_irqsave(&timekeeper_lock, flags);
2026 write_seqcount_begin(&tk_core.seq);
2027
2028 __hardpps(phase_ts, raw_ts);
2029
2030 write_seqcount_end(&tk_core.seq);
2031 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2032}
2033EXPORT_SYMBOL(hardpps);
2034#endif
2035
2036/**
2037 * xtime_update() - advances the timekeeping infrastructure
2038 * @ticks: number of ticks, that have elapsed since the last call.
2039 *
2040 * Must be called with interrupts disabled.
2041 */
2042void xtime_update(unsigned long ticks)
2043{
2044 write_seqlock(&jiffies_lock);
2045 do_timer(ticks);
2046 write_sequnlock(&jiffies_lock);
2047 update_wall_time();
2048}