2 * linux/kernel/time/timekeeping.c
4 * Kernel timekeeping code and accessor functions
6 * This code was moved from linux/kernel/timer.c.
7 * Please see that file for copyright and history logs.
11 #include <linux/timekeeper_internal.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/percpu.h>
15 #include <linux/init.h>
17 #include <linux/sched.h>
18 #include <linux/syscore_ops.h>
19 #include <linux/clocksource.h>
20 #include <linux/jiffies.h>
21 #include <linux/time.h>
22 #include <linux/tick.h>
23 #include <linux/stop_machine.h>
24 #include <linux/pvclock_gtod.h>
25 #include <linux/compiler.h>
27 #include "tick-internal.h"
28 #include "ntp_internal.h"
29 #include "timekeeping_internal.h"
31 #define TK_CLEAR_NTP (1 << 0)
32 #define TK_MIRROR (1 << 1)
33 #define TK_CLOCK_WAS_SET (1 << 2)
36 * The most important data for readout fits into a single 64 byte
41 struct timekeeper timekeeper
;
42 } tk_core ____cacheline_aligned
;
44 static DEFINE_RAW_SPINLOCK(timekeeper_lock
);
45 static struct timekeeper shadow_timekeeper
;
47 /* flag for if timekeeping is suspended */
48 int __read_mostly timekeeping_suspended
;
50 /* Flag for if there is a persistent clock on this platform */
51 bool __read_mostly persistent_clock_exist
= false;
53 static inline void tk_normalize_xtime(struct timekeeper
*tk
)
55 while (tk
->xtime_nsec
>= ((u64
)NSEC_PER_SEC
<< tk
->shift
)) {
56 tk
->xtime_nsec
-= (u64
)NSEC_PER_SEC
<< tk
->shift
;
61 static inline struct timespec64
tk_xtime(struct timekeeper
*tk
)
65 ts
.tv_sec
= tk
->xtime_sec
;
66 ts
.tv_nsec
= (long)(tk
->xtime_nsec
>> tk
->shift
);
70 static void tk_set_xtime(struct timekeeper
*tk
, const struct timespec64
*ts
)
72 tk
->xtime_sec
= ts
->tv_sec
;
73 tk
->xtime_nsec
= (u64
)ts
->tv_nsec
<< tk
->shift
;
76 static void tk_xtime_add(struct timekeeper
*tk
, const struct timespec64
*ts
)
78 tk
->xtime_sec
+= ts
->tv_sec
;
79 tk
->xtime_nsec
+= (u64
)ts
->tv_nsec
<< tk
->shift
;
80 tk_normalize_xtime(tk
);
83 static void tk_set_wall_to_mono(struct timekeeper
*tk
, struct timespec64 wtm
)
85 struct timespec64 tmp
;
88 * Verify consistency of: offset_real = -wall_to_monotonic
89 * before modifying anything
91 set_normalized_timespec64(&tmp
, -tk
->wall_to_monotonic
.tv_sec
,
92 -tk
->wall_to_monotonic
.tv_nsec
);
93 WARN_ON_ONCE(tk
->offs_real
.tv64
!= timespec64_to_ktime(tmp
).tv64
);
94 tk
->wall_to_monotonic
= wtm
;
95 set_normalized_timespec64(&tmp
, -wtm
.tv_sec
, -wtm
.tv_nsec
);
96 tk
->offs_real
= timespec64_to_ktime(tmp
);
97 tk
->offs_tai
= ktime_add(tk
->offs_real
, ktime_set(tk
->tai_offset
, 0));
100 static void tk_set_sleep_time(struct timekeeper
*tk
, struct timespec64 t
)
102 /* Verify consistency before modifying */
103 WARN_ON_ONCE(tk
->offs_boot
.tv64
!= timespec64_to_ktime(tk
->total_sleep_time
).tv64
);
105 tk
->total_sleep_time
= t
;
106 tk
->offs_boot
= timespec64_to_ktime(t
);
110 * tk_setup_internals - Set up internals to use clocksource clock.
112 * @tk: The target timekeeper to setup.
113 * @clock: Pointer to clocksource.
115 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
116 * pair and interval request.
118 * Unless you're the timekeeping code, you should not be using this!
120 static void tk_setup_internals(struct timekeeper
*tk
, struct clocksource
*clock
)
123 u64 tmp
, ntpinterval
;
124 struct clocksource
*old_clock
;
126 old_clock
= tk
->clock
;
128 tk
->cycle_last
= clock
->cycle_last
= clock
->read(clock
);
130 /* Do the ns -> cycle conversion first, using original mult */
131 tmp
= NTP_INTERVAL_LENGTH
;
132 tmp
<<= clock
->shift
;
134 tmp
+= clock
->mult
/2;
135 do_div(tmp
, clock
->mult
);
139 interval
= (cycle_t
) tmp
;
140 tk
->cycle_interval
= interval
;
142 /* Go back from cycles -> shifted ns */
143 tk
->xtime_interval
= (u64
) interval
* clock
->mult
;
144 tk
->xtime_remainder
= ntpinterval
- tk
->xtime_interval
;
146 ((u64
) interval
* clock
->mult
) >> clock
->shift
;
148 /* if changing clocks, convert xtime_nsec shift units */
150 int shift_change
= clock
->shift
- old_clock
->shift
;
151 if (shift_change
< 0)
152 tk
->xtime_nsec
>>= -shift_change
;
154 tk
->xtime_nsec
<<= shift_change
;
156 tk
->shift
= clock
->shift
;
159 tk
->ntp_error_shift
= NTP_SCALE_SHIFT
- clock
->shift
;
162 * The timekeeper keeps its own mult values for the currently
163 * active clocksource. These value will be adjusted via NTP
164 * to counteract clock drifting.
166 tk
->mult
= clock
->mult
;
169 /* Timekeeper helper functions. */
171 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
172 static u32
default_arch_gettimeoffset(void) { return 0; }
173 u32 (*arch_gettimeoffset
)(void) = default_arch_gettimeoffset
;
175 static inline u32
arch_gettimeoffset(void) { return 0; }
178 static inline s64
timekeeping_get_ns(struct timekeeper
*tk
)
180 cycle_t cycle_now
, cycle_delta
;
181 struct clocksource
*clock
;
184 /* read clocksource: */
186 cycle_now
= clock
->read(clock
);
188 /* calculate the delta since the last update_wall_time: */
189 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
191 nsec
= cycle_delta
* tk
->mult
+ tk
->xtime_nsec
;
194 /* If arch requires, add in get_arch_timeoffset() */
195 return nsec
+ arch_gettimeoffset();
198 static inline s64
timekeeping_get_ns_raw(struct timekeeper
*tk
)
200 cycle_t cycle_now
, cycle_delta
;
201 struct clocksource
*clock
;
204 /* read clocksource: */
206 cycle_now
= clock
->read(clock
);
208 /* calculate the delta since the last update_wall_time: */
209 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
211 /* convert delta to nanoseconds. */
212 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
214 /* If arch requires, add in get_arch_timeoffset() */
215 return nsec
+ arch_gettimeoffset();
218 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
220 static inline void update_vsyscall(struct timekeeper
*tk
)
225 update_vsyscall_old(&xt
, &tk
->wall_to_monotonic
, tk
->clock
, tk
->mult
);
228 static inline void old_vsyscall_fixup(struct timekeeper
*tk
)
233 * Store only full nanoseconds into xtime_nsec after rounding
234 * it up and add the remainder to the error difference.
235 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
236 * by truncating the remainder in vsyscalls. However, it causes
237 * additional work to be done in timekeeping_adjust(). Once
238 * the vsyscall implementations are converted to use xtime_nsec
239 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
240 * users are removed, this can be killed.
242 remainder
= tk
->xtime_nsec
& ((1ULL << tk
->shift
) - 1);
243 tk
->xtime_nsec
-= remainder
;
244 tk
->xtime_nsec
+= 1ULL << tk
->shift
;
245 tk
->ntp_error
+= remainder
<< tk
->ntp_error_shift
;
246 tk
->ntp_error
-= (1ULL << tk
->shift
) << tk
->ntp_error_shift
;
249 #define old_vsyscall_fixup(tk)
252 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain
);
254 static void update_pvclock_gtod(struct timekeeper
*tk
, bool was_set
)
256 raw_notifier_call_chain(&pvclock_gtod_chain
, was_set
, tk
);
260 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
262 int pvclock_gtod_register_notifier(struct notifier_block
*nb
)
264 struct timekeeper
*tk
= &tk_core
.timekeeper
;
268 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
269 ret
= raw_notifier_chain_register(&pvclock_gtod_chain
, nb
);
270 update_pvclock_gtod(tk
, true);
271 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
275 EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier
);
278 * pvclock_gtod_unregister_notifier - unregister a pvclock
279 * timedata update listener
281 int pvclock_gtod_unregister_notifier(struct notifier_block
*nb
)
286 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
287 ret
= raw_notifier_chain_unregister(&pvclock_gtod_chain
, nb
);
288 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
292 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier
);
295 * Update the ktime_t based scalar nsec members of the timekeeper
297 static inline void tk_update_ktime_data(struct timekeeper
*tk
)
302 * The xtime based monotonic readout is:
303 * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now();
304 * The ktime based monotonic readout is:
305 * nsec = base_mono + now();
306 * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec
308 nsec
= (s64
)(tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
);
309 nsec
*= NSEC_PER_SEC
;
310 nsec
+= tk
->wall_to_monotonic
.tv_nsec
;
311 tk
->base_mono
= ns_to_ktime(nsec
);
314 /* must hold timekeeper_lock */
315 static void timekeeping_update(struct timekeeper
*tk
, unsigned int action
)
317 if (action
& TK_CLEAR_NTP
) {
322 update_pvclock_gtod(tk
, action
& TK_CLOCK_WAS_SET
);
324 tk_update_ktime_data(tk
);
326 if (action
& TK_MIRROR
)
327 memcpy(&shadow_timekeeper
, &tk_core
.timekeeper
,
328 sizeof(tk_core
.timekeeper
));
332 * timekeeping_forward_now - update clock to the current time
334 * Forward the current clock to update its state since the last call to
335 * update_wall_time(). This is useful before significant clock changes,
336 * as it avoids having to deal with this time offset explicitly.
338 static void timekeeping_forward_now(struct timekeeper
*tk
)
340 cycle_t cycle_now
, cycle_delta
;
341 struct clocksource
*clock
;
345 cycle_now
= clock
->read(clock
);
346 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
347 tk
->cycle_last
= clock
->cycle_last
= cycle_now
;
349 tk
->xtime_nsec
+= cycle_delta
* tk
->mult
;
351 /* If arch requires, add in get_arch_timeoffset() */
352 tk
->xtime_nsec
+= (u64
)arch_gettimeoffset() << tk
->shift
;
354 tk_normalize_xtime(tk
);
356 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
357 timespec64_add_ns(&tk
->raw_time
, nsec
);
361 * __getnstimeofday64 - Returns the time of day in a timespec64.
362 * @ts: pointer to the timespec to be set
364 * Updates the time of day in the timespec.
365 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
367 int __getnstimeofday64(struct timespec64
*ts
)
369 struct timekeeper
*tk
= &tk_core
.timekeeper
;
374 seq
= read_seqcount_begin(&tk_core
.seq
);
376 ts
->tv_sec
= tk
->xtime_sec
;
377 nsecs
= timekeeping_get_ns(tk
);
379 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
382 timespec64_add_ns(ts
, nsecs
);
385 * Do not bail out early, in case there were callers still using
386 * the value, even in the face of the WARN_ON.
388 if (unlikely(timekeeping_suspended
))
392 EXPORT_SYMBOL(__getnstimeofday64
);
395 * getnstimeofday64 - Returns the time of day in a timespec64.
396 * @ts: pointer to the timespec to be set
398 * Returns the time of day in a timespec (WARN if suspended).
400 void getnstimeofday64(struct timespec64
*ts
)
402 WARN_ON(__getnstimeofday64(ts
));
404 EXPORT_SYMBOL(getnstimeofday64
);
406 ktime_t
ktime_get(void)
408 struct timekeeper
*tk
= &tk_core
.timekeeper
;
413 WARN_ON(timekeeping_suspended
);
416 seq
= read_seqcount_begin(&tk_core
.seq
);
417 base
= tk
->base_mono
;
418 nsecs
= timekeeping_get_ns(tk
);
420 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
422 return ktime_add_ns(base
, nsecs
);
424 EXPORT_SYMBOL_GPL(ktime_get
);
426 static ktime_t
*offsets
[TK_OFFS_MAX
] = {
427 [TK_OFFS_REAL
] = &tk_core
.timekeeper
.offs_real
,
428 [TK_OFFS_BOOT
] = &tk_core
.timekeeper
.offs_boot
,
429 [TK_OFFS_TAI
] = &tk_core
.timekeeper
.offs_tai
,
432 ktime_t
ktime_get_with_offset(enum tk_offsets offs
)
434 struct timekeeper
*tk
= &tk_core
.timekeeper
;
436 ktime_t base
, *offset
= offsets
[offs
];
439 WARN_ON(timekeeping_suspended
);
442 seq
= read_seqcount_begin(&tk_core
.seq
);
443 base
= ktime_add(tk
->base_mono
, *offset
);
444 nsecs
= timekeeping_get_ns(tk
);
446 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
448 return ktime_add_ns(base
, nsecs
);
451 EXPORT_SYMBOL_GPL(ktime_get_with_offset
);
454 * ktime_get_ts64 - get the monotonic clock in timespec64 format
455 * @ts: pointer to timespec variable
457 * The function calculates the monotonic clock from the realtime
458 * clock and the wall_to_monotonic offset and stores the result
459 * in normalized timespec format in the variable pointed to by @ts.
461 void ktime_get_ts64(struct timespec64
*ts
)
463 struct timekeeper
*tk
= &tk_core
.timekeeper
;
464 struct timespec64 tomono
;
468 WARN_ON(timekeeping_suspended
);
471 seq
= read_seqcount_begin(&tk_core
.seq
);
472 ts
->tv_sec
= tk
->xtime_sec
;
473 nsec
= timekeeping_get_ns(tk
);
474 tomono
= tk
->wall_to_monotonic
;
476 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
478 ts
->tv_sec
+= tomono
.tv_sec
;
480 timespec64_add_ns(ts
, nsec
+ tomono
.tv_nsec
);
482 EXPORT_SYMBOL_GPL(ktime_get_ts64
);
486 * timekeeping_clocktai - Returns the TAI time of day in a timespec
487 * @ts: pointer to the timespec to be set
489 * Returns the time of day in a timespec.
491 void timekeeping_clocktai(struct timespec
*ts
)
493 struct timekeeper
*tk
= &tk_core
.timekeeper
;
494 struct timespec64 ts64
;
498 WARN_ON(timekeeping_suspended
);
501 seq
= read_seqcount_begin(&tk_core
.seq
);
503 ts64
.tv_sec
= tk
->xtime_sec
+ tk
->tai_offset
;
504 nsecs
= timekeeping_get_ns(tk
);
506 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
509 timespec64_add_ns(&ts64
, nsecs
);
510 *ts
= timespec64_to_timespec(ts64
);
513 EXPORT_SYMBOL(timekeeping_clocktai
);
515 #ifdef CONFIG_NTP_PPS
518 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
519 * @ts_raw: pointer to the timespec to be set to raw monotonic time
520 * @ts_real: pointer to the timespec to be set to the time of day
522 * This function reads both the time of day and raw monotonic time at the
523 * same time atomically and stores the resulting timestamps in timespec
526 void getnstime_raw_and_real(struct timespec
*ts_raw
, struct timespec
*ts_real
)
528 struct timekeeper
*tk
= &tk_core
.timekeeper
;
530 s64 nsecs_raw
, nsecs_real
;
532 WARN_ON_ONCE(timekeeping_suspended
);
535 seq
= read_seqcount_begin(&tk_core
.seq
);
537 *ts_raw
= timespec64_to_timespec(tk
->raw_time
);
538 ts_real
->tv_sec
= tk
->xtime_sec
;
539 ts_real
->tv_nsec
= 0;
541 nsecs_raw
= timekeeping_get_ns_raw(tk
);
542 nsecs_real
= timekeeping_get_ns(tk
);
544 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
546 timespec_add_ns(ts_raw
, nsecs_raw
);
547 timespec_add_ns(ts_real
, nsecs_real
);
549 EXPORT_SYMBOL(getnstime_raw_and_real
);
551 #endif /* CONFIG_NTP_PPS */
554 * do_gettimeofday - Returns the time of day in a timeval
555 * @tv: pointer to the timeval to be set
557 * NOTE: Users should be converted to using getnstimeofday()
559 void do_gettimeofday(struct timeval
*tv
)
561 struct timespec64 now
;
563 getnstimeofday64(&now
);
564 tv
->tv_sec
= now
.tv_sec
;
565 tv
->tv_usec
= now
.tv_nsec
/1000;
567 EXPORT_SYMBOL(do_gettimeofday
);
570 * do_settimeofday - Sets the time of day
571 * @tv: pointer to the timespec variable containing the new time
573 * Sets the time of day to the new time and update NTP and notify hrtimers
575 int do_settimeofday(const struct timespec
*tv
)
577 struct timekeeper
*tk
= &tk_core
.timekeeper
;
578 struct timespec64 ts_delta
, xt
, tmp
;
581 if (!timespec_valid_strict(tv
))
584 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
585 write_seqcount_begin(&tk_core
.seq
);
587 timekeeping_forward_now(tk
);
590 ts_delta
.tv_sec
= tv
->tv_sec
- xt
.tv_sec
;
591 ts_delta
.tv_nsec
= tv
->tv_nsec
- xt
.tv_nsec
;
593 tk_set_wall_to_mono(tk
, timespec64_sub(tk
->wall_to_monotonic
, ts_delta
));
595 tmp
= timespec_to_timespec64(*tv
);
596 tk_set_xtime(tk
, &tmp
);
598 timekeeping_update(tk
, TK_CLEAR_NTP
| TK_MIRROR
| TK_CLOCK_WAS_SET
);
600 write_seqcount_end(&tk_core
.seq
);
601 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
603 /* signal hrtimers about time change */
608 EXPORT_SYMBOL(do_settimeofday
);
611 * timekeeping_inject_offset - Adds or subtracts from the current time.
612 * @tv: pointer to the timespec variable containing the offset
614 * Adds or subtracts an offset value from the current time.
616 int timekeeping_inject_offset(struct timespec
*ts
)
618 struct timekeeper
*tk
= &tk_core
.timekeeper
;
620 struct timespec64 ts64
, tmp
;
623 if ((unsigned long)ts
->tv_nsec
>= NSEC_PER_SEC
)
626 ts64
= timespec_to_timespec64(*ts
);
628 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
629 write_seqcount_begin(&tk_core
.seq
);
631 timekeeping_forward_now(tk
);
633 /* Make sure the proposed value is valid */
634 tmp
= timespec64_add(tk_xtime(tk
), ts64
);
635 if (!timespec64_valid_strict(&tmp
)) {
640 tk_xtime_add(tk
, &ts64
);
641 tk_set_wall_to_mono(tk
, timespec64_sub(tk
->wall_to_monotonic
, ts64
));
643 error
: /* even if we error out, we forwarded the time, so call update */
644 timekeeping_update(tk
, TK_CLEAR_NTP
| TK_MIRROR
| TK_CLOCK_WAS_SET
);
646 write_seqcount_end(&tk_core
.seq
);
647 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
649 /* signal hrtimers about time change */
654 EXPORT_SYMBOL(timekeeping_inject_offset
);
658 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
661 s32
timekeeping_get_tai_offset(void)
663 struct timekeeper
*tk
= &tk_core
.timekeeper
;
668 seq
= read_seqcount_begin(&tk_core
.seq
);
669 ret
= tk
->tai_offset
;
670 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
676 * __timekeeping_set_tai_offset - Lock free worker function
679 static void __timekeeping_set_tai_offset(struct timekeeper
*tk
, s32 tai_offset
)
681 tk
->tai_offset
= tai_offset
;
682 tk
->offs_tai
= ktime_add(tk
->offs_real
, ktime_set(tai_offset
, 0));
686 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
689 void timekeeping_set_tai_offset(s32 tai_offset
)
691 struct timekeeper
*tk
= &tk_core
.timekeeper
;
694 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
695 write_seqcount_begin(&tk_core
.seq
);
696 __timekeeping_set_tai_offset(tk
, tai_offset
);
697 timekeeping_update(tk
, TK_MIRROR
| TK_CLOCK_WAS_SET
);
698 write_seqcount_end(&tk_core
.seq
);
699 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
704 * change_clocksource - Swaps clocksources if a new one is available
706 * Accumulates current time interval and initializes new clocksource
708 static int change_clocksource(void *data
)
710 struct timekeeper
*tk
= &tk_core
.timekeeper
;
711 struct clocksource
*new, *old
;
714 new = (struct clocksource
*) data
;
716 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
717 write_seqcount_begin(&tk_core
.seq
);
719 timekeeping_forward_now(tk
);
721 * If the cs is in module, get a module reference. Succeeds
722 * for built-in code (owner == NULL) as well.
724 if (try_module_get(new->owner
)) {
725 if (!new->enable
|| new->enable(new) == 0) {
727 tk_setup_internals(tk
, new);
730 module_put(old
->owner
);
732 module_put(new->owner
);
735 timekeeping_update(tk
, TK_CLEAR_NTP
| TK_MIRROR
| TK_CLOCK_WAS_SET
);
737 write_seqcount_end(&tk_core
.seq
);
738 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
744 * timekeeping_notify - Install a new clock source
745 * @clock: pointer to the clock source
747 * This function is called from clocksource.c after a new, better clock
748 * source has been registered. The caller holds the clocksource_mutex.
750 int timekeeping_notify(struct clocksource
*clock
)
752 struct timekeeper
*tk
= &tk_core
.timekeeper
;
754 if (tk
->clock
== clock
)
756 stop_machine(change_clocksource
, clock
, NULL
);
758 return tk
->clock
== clock
? 0 : -1;
762 * getrawmonotonic - Returns the raw monotonic time in a timespec
763 * @ts: pointer to the timespec to be set
765 * Returns the raw monotonic time (completely un-modified by ntp)
767 void getrawmonotonic(struct timespec
*ts
)
769 struct timekeeper
*tk
= &tk_core
.timekeeper
;
770 struct timespec64 ts64
;
775 seq
= read_seqcount_begin(&tk_core
.seq
);
776 nsecs
= timekeeping_get_ns_raw(tk
);
779 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
781 timespec64_add_ns(&ts64
, nsecs
);
782 *ts
= timespec64_to_timespec(ts64
);
784 EXPORT_SYMBOL(getrawmonotonic
);
787 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
789 int timekeeping_valid_for_hres(void)
791 struct timekeeper
*tk
= &tk_core
.timekeeper
;
796 seq
= read_seqcount_begin(&tk_core
.seq
);
798 ret
= tk
->clock
->flags
& CLOCK_SOURCE_VALID_FOR_HRES
;
800 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
806 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
808 u64
timekeeping_max_deferment(void)
810 struct timekeeper
*tk
= &tk_core
.timekeeper
;
815 seq
= read_seqcount_begin(&tk_core
.seq
);
817 ret
= tk
->clock
->max_idle_ns
;
819 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
825 * read_persistent_clock - Return time from the persistent clock.
827 * Weak dummy function for arches that do not yet support it.
828 * Reads the time from the battery backed persistent clock.
829 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
831 * XXX - Do be sure to remove it once all arches implement it.
833 void __weak
read_persistent_clock(struct timespec
*ts
)
840 * read_boot_clock - Return time of the system start.
842 * Weak dummy function for arches that do not yet support it.
843 * Function to read the exact time the system has been started.
844 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
846 * XXX - Do be sure to remove it once all arches implement it.
848 void __weak
read_boot_clock(struct timespec
*ts
)
855 * timekeeping_init - Initializes the clocksource and common timekeeping values
857 void __init
timekeeping_init(void)
859 struct timekeeper
*tk
= &tk_core
.timekeeper
;
860 struct clocksource
*clock
;
862 struct timespec64 now
, boot
, tmp
;
865 read_persistent_clock(&ts
);
866 now
= timespec_to_timespec64(ts
);
867 if (!timespec64_valid_strict(&now
)) {
868 pr_warn("WARNING: Persistent clock returned invalid value!\n"
869 " Check your CMOS/BIOS settings.\n");
872 } else if (now
.tv_sec
|| now
.tv_nsec
)
873 persistent_clock_exist
= true;
875 read_boot_clock(&ts
);
876 boot
= timespec_to_timespec64(ts
);
877 if (!timespec64_valid_strict(&boot
)) {
878 pr_warn("WARNING: Boot clock returned invalid value!\n"
879 " Check your CMOS/BIOS settings.\n");
884 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
885 write_seqcount_begin(&tk_core
.seq
);
888 clock
= clocksource_default_clock();
890 clock
->enable(clock
);
891 tk_setup_internals(tk
, clock
);
893 tk_set_xtime(tk
, &now
);
894 tk
->raw_time
.tv_sec
= 0;
895 tk
->raw_time
.tv_nsec
= 0;
896 if (boot
.tv_sec
== 0 && boot
.tv_nsec
== 0)
899 set_normalized_timespec64(&tmp
, -boot
.tv_sec
, -boot
.tv_nsec
);
900 tk_set_wall_to_mono(tk
, tmp
);
904 tk_set_sleep_time(tk
, tmp
);
906 timekeeping_update(tk
, TK_MIRROR
);
908 write_seqcount_end(&tk_core
.seq
);
909 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
912 /* time in seconds when suspend began */
913 static struct timespec64 timekeeping_suspend_time
;
916 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
917 * @delta: pointer to a timespec delta value
919 * Takes a timespec offset measuring a suspend interval and properly
920 * adds the sleep offset to the timekeeping variables.
922 static void __timekeeping_inject_sleeptime(struct timekeeper
*tk
,
923 struct timespec64
*delta
)
925 if (!timespec64_valid_strict(delta
)) {
926 printk_deferred(KERN_WARNING
927 "__timekeeping_inject_sleeptime: Invalid "
928 "sleep delta value!\n");
931 tk_xtime_add(tk
, delta
);
932 tk_set_wall_to_mono(tk
, timespec64_sub(tk
->wall_to_monotonic
, *delta
));
933 tk_set_sleep_time(tk
, timespec64_add(tk
->total_sleep_time
, *delta
));
934 tk_debug_account_sleep_time(delta
);
938 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
939 * @delta: pointer to a timespec delta value
941 * This hook is for architectures that cannot support read_persistent_clock
942 * because their RTC/persistent clock is only accessible when irqs are enabled.
944 * This function should only be called by rtc_resume(), and allows
945 * a suspend offset to be injected into the timekeeping values.
947 void timekeeping_inject_sleeptime(struct timespec
*delta
)
949 struct timekeeper
*tk
= &tk_core
.timekeeper
;
950 struct timespec64 tmp
;
954 * Make sure we don't set the clock twice, as timekeeping_resume()
957 if (has_persistent_clock())
960 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
961 write_seqcount_begin(&tk_core
.seq
);
963 timekeeping_forward_now(tk
);
965 tmp
= timespec_to_timespec64(*delta
);
966 __timekeeping_inject_sleeptime(tk
, &tmp
);
968 timekeeping_update(tk
, TK_CLEAR_NTP
| TK_MIRROR
| TK_CLOCK_WAS_SET
);
970 write_seqcount_end(&tk_core
.seq
);
971 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
973 /* signal hrtimers about time change */
978 * timekeeping_resume - Resumes the generic timekeeping subsystem.
980 * This is for the generic clocksource timekeeping.
981 * xtime/wall_to_monotonic/jiffies/etc are
982 * still managed by arch specific suspend/resume code.
984 static void timekeeping_resume(void)
986 struct timekeeper
*tk
= &tk_core
.timekeeper
;
987 struct clocksource
*clock
= tk
->clock
;
989 struct timespec64 ts_new
, ts_delta
;
991 cycle_t cycle_now
, cycle_delta
;
992 bool suspendtime_found
= false;
994 read_persistent_clock(&tmp
);
995 ts_new
= timespec_to_timespec64(tmp
);
997 clockevents_resume();
998 clocksource_resume();
1000 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1001 write_seqcount_begin(&tk_core
.seq
);
1004 * After system resumes, we need to calculate the suspended time and
1005 * compensate it for the OS time. There are 3 sources that could be
1006 * used: Nonstop clocksource during suspend, persistent clock and rtc
1009 * One specific platform may have 1 or 2 or all of them, and the
1010 * preference will be:
1011 * suspend-nonstop clocksource -> persistent clock -> rtc
1012 * The less preferred source will only be tried if there is no better
1013 * usable source. The rtc part is handled separately in rtc core code.
1015 cycle_now
= clock
->read(clock
);
1016 if ((clock
->flags
& CLOCK_SOURCE_SUSPEND_NONSTOP
) &&
1017 cycle_now
> clock
->cycle_last
) {
1018 u64 num
, max
= ULLONG_MAX
;
1019 u32 mult
= clock
->mult
;
1020 u32 shift
= clock
->shift
;
1023 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
1026 * "cycle_delta * mutl" may cause 64 bits overflow, if the
1027 * suspended time is too long. In that case we need do the
1028 * 64 bits math carefully
1031 if (cycle_delta
> max
) {
1032 num
= div64_u64(cycle_delta
, max
);
1033 nsec
= (((u64
) max
* mult
) >> shift
) * num
;
1034 cycle_delta
-= num
* max
;
1036 nsec
+= ((u64
) cycle_delta
* mult
) >> shift
;
1038 ts_delta
= ns_to_timespec64(nsec
);
1039 suspendtime_found
= true;
1040 } else if (timespec64_compare(&ts_new
, &timekeeping_suspend_time
) > 0) {
1041 ts_delta
= timespec64_sub(ts_new
, timekeeping_suspend_time
);
1042 suspendtime_found
= true;
1045 if (suspendtime_found
)
1046 __timekeeping_inject_sleeptime(tk
, &ts_delta
);
1048 /* Re-base the last cycle value */
1049 tk
->cycle_last
= clock
->cycle_last
= cycle_now
;
1051 timekeeping_suspended
= 0;
1052 timekeeping_update(tk
, TK_MIRROR
| TK_CLOCK_WAS_SET
);
1053 write_seqcount_end(&tk_core
.seq
);
1054 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1056 touch_softlockup_watchdog();
1058 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME
, NULL
);
1060 /* Resume hrtimers */
1064 static int timekeeping_suspend(void)
1066 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1067 unsigned long flags
;
1068 struct timespec64 delta
, delta_delta
;
1069 static struct timespec64 old_delta
;
1070 struct timespec tmp
;
1072 read_persistent_clock(&tmp
);
1073 timekeeping_suspend_time
= timespec_to_timespec64(tmp
);
1076 * On some systems the persistent_clock can not be detected at
1077 * timekeeping_init by its return value, so if we see a valid
1078 * value returned, update the persistent_clock_exists flag.
1080 if (timekeeping_suspend_time
.tv_sec
|| timekeeping_suspend_time
.tv_nsec
)
1081 persistent_clock_exist
= true;
1083 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1084 write_seqcount_begin(&tk_core
.seq
);
1085 timekeeping_forward_now(tk
);
1086 timekeeping_suspended
= 1;
1089 * To avoid drift caused by repeated suspend/resumes,
1090 * which each can add ~1 second drift error,
1091 * try to compensate so the difference in system time
1092 * and persistent_clock time stays close to constant.
1094 delta
= timespec64_sub(tk_xtime(tk
), timekeeping_suspend_time
);
1095 delta_delta
= timespec64_sub(delta
, old_delta
);
1096 if (abs(delta_delta
.tv_sec
) >= 2) {
1098 * if delta_delta is too large, assume time correction
1099 * has occured and set old_delta to the current delta.
1103 /* Otherwise try to adjust old_system to compensate */
1104 timekeeping_suspend_time
=
1105 timespec64_add(timekeeping_suspend_time
, delta_delta
);
1108 timekeeping_update(tk
, TK_MIRROR
);
1109 write_seqcount_end(&tk_core
.seq
);
1110 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1112 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND
, NULL
);
1113 clocksource_suspend();
1114 clockevents_suspend();
1119 /* sysfs resume/suspend bits for timekeeping */
1120 static struct syscore_ops timekeeping_syscore_ops
= {
1121 .resume
= timekeeping_resume
,
1122 .suspend
= timekeeping_suspend
,
1125 static int __init
timekeeping_init_ops(void)
1127 register_syscore_ops(&timekeeping_syscore_ops
);
1131 device_initcall(timekeeping_init_ops
);
1134 * If the error is already larger, we look ahead even further
1135 * to compensate for late or lost adjustments.
1137 static __always_inline
int timekeeping_bigadjust(struct timekeeper
*tk
,
1138 s64 error
, s64
*interval
,
1142 u32 look_ahead
, adj
;
1146 * Use the current error value to determine how much to look ahead.
1147 * The larger the error the slower we adjust for it to avoid problems
1148 * with losing too many ticks, otherwise we would overadjust and
1149 * produce an even larger error. The smaller the adjustment the
1150 * faster we try to adjust for it, as lost ticks can do less harm
1151 * here. This is tuned so that an error of about 1 msec is adjusted
1152 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
1154 error2
= tk
->ntp_error
>> (NTP_SCALE_SHIFT
+ 22 - 2 * SHIFT_HZ
);
1155 error2
= abs(error2
);
1156 for (look_ahead
= 0; error2
> 0; look_ahead
++)
1160 * Now calculate the error in (1 << look_ahead) ticks, but first
1161 * remove the single look ahead already included in the error.
1163 tick_error
= ntp_tick_length() >> (tk
->ntp_error_shift
+ 1);
1164 tick_error
-= tk
->xtime_interval
>> 1;
1165 error
= ((error
- tick_error
) >> look_ahead
) + tick_error
;
1167 /* Finally calculate the adjustment shift value. */
1172 *interval
= -*interval
;
1176 for (adj
= 0; error
> i
; adj
++)
1185 * Adjust the multiplier to reduce the error value,
1186 * this is optimized for the most common adjustments of -1,0,1,
1187 * for other values we can do a bit more work.
1189 static void timekeeping_adjust(struct timekeeper
*tk
, s64 offset
)
1191 s64 error
, interval
= tk
->cycle_interval
;
1195 * The point of this is to check if the error is greater than half
1198 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
1200 * Note we subtract one in the shift, so that error is really error*2.
1201 * This "saves" dividing(shifting) interval twice, but keeps the
1202 * (error > interval) comparison as still measuring if error is
1203 * larger than half an interval.
1205 * Note: It does not "save" on aggravation when reading the code.
1207 error
= tk
->ntp_error
>> (tk
->ntp_error_shift
- 1);
1208 if (error
> interval
) {
1210 * We now divide error by 4(via shift), which checks if
1211 * the error is greater than twice the interval.
1212 * If it is greater, we need a bigadjust, if its smaller,
1213 * we can adjust by 1.
1216 if (likely(error
<= interval
))
1219 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1221 if (error
< -interval
) {
1222 /* See comment above, this is just switched for the negative */
1224 if (likely(error
>= -interval
)) {
1226 interval
= -interval
;
1229 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1236 if (unlikely(tk
->clock
->maxadj
&&
1237 (tk
->mult
+ adj
> tk
->clock
->mult
+ tk
->clock
->maxadj
))) {
1238 printk_deferred_once(KERN_WARNING
1239 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1240 tk
->clock
->name
, (long)tk
->mult
+ adj
,
1241 (long)tk
->clock
->mult
+ tk
->clock
->maxadj
);
1244 * So the following can be confusing.
1246 * To keep things simple, lets assume adj == 1 for now.
1248 * When adj != 1, remember that the interval and offset values
1249 * have been appropriately scaled so the math is the same.
1251 * The basic idea here is that we're increasing the multiplier
1252 * by one, this causes the xtime_interval to be incremented by
1253 * one cycle_interval. This is because:
1254 * xtime_interval = cycle_interval * mult
1255 * So if mult is being incremented by one:
1256 * xtime_interval = cycle_interval * (mult + 1)
1258 * xtime_interval = (cycle_interval * mult) + cycle_interval
1259 * Which can be shortened to:
1260 * xtime_interval += cycle_interval
1262 * So offset stores the non-accumulated cycles. Thus the current
1263 * time (in shifted nanoseconds) is:
1264 * now = (offset * adj) + xtime_nsec
1265 * Now, even though we're adjusting the clock frequency, we have
1266 * to keep time consistent. In other words, we can't jump back
1267 * in time, and we also want to avoid jumping forward in time.
1269 * So given the same offset value, we need the time to be the same
1270 * both before and after the freq adjustment.
1271 * now = (offset * adj_1) + xtime_nsec_1
1272 * now = (offset * adj_2) + xtime_nsec_2
1274 * (offset * adj_1) + xtime_nsec_1 =
1275 * (offset * adj_2) + xtime_nsec_2
1279 * (offset * adj_1) + xtime_nsec_1 =
1280 * (offset * (adj_1+1)) + xtime_nsec_2
1281 * (offset * adj_1) + xtime_nsec_1 =
1282 * (offset * adj_1) + offset + xtime_nsec_2
1283 * Canceling the sides:
1284 * xtime_nsec_1 = offset + xtime_nsec_2
1286 * xtime_nsec_2 = xtime_nsec_1 - offset
1287 * Which simplfies to:
1288 * xtime_nsec -= offset
1290 * XXX - TODO: Doc ntp_error calculation.
1293 tk
->xtime_interval
+= interval
;
1294 tk
->xtime_nsec
-= offset
;
1295 tk
->ntp_error
-= (interval
- offset
) << tk
->ntp_error_shift
;
1299 * It may be possible that when we entered this function, xtime_nsec
1300 * was very small. Further, if we're slightly speeding the clocksource
1301 * in the code above, its possible the required corrective factor to
1302 * xtime_nsec could cause it to underflow.
1304 * Now, since we already accumulated the second, cannot simply roll
1305 * the accumulated second back, since the NTP subsystem has been
1306 * notified via second_overflow. So instead we push xtime_nsec forward
1307 * by the amount we underflowed, and add that amount into the error.
1309 * We'll correct this error next time through this function, when
1310 * xtime_nsec is not as small.
1312 if (unlikely((s64
)tk
->xtime_nsec
< 0)) {
1313 s64 neg
= -(s64
)tk
->xtime_nsec
;
1315 tk
->ntp_error
+= neg
<< tk
->ntp_error_shift
;
1321 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1323 * Helper function that accumulates a the nsecs greater then a second
1324 * from the xtime_nsec field to the xtime_secs field.
1325 * It also calls into the NTP code to handle leapsecond processing.
1328 static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper
*tk
)
1330 u64 nsecps
= (u64
)NSEC_PER_SEC
<< tk
->shift
;
1331 unsigned int clock_set
= 0;
1333 while (tk
->xtime_nsec
>= nsecps
) {
1336 tk
->xtime_nsec
-= nsecps
;
1339 /* Figure out if its a leap sec and apply if needed */
1340 leap
= second_overflow(tk
->xtime_sec
);
1341 if (unlikely(leap
)) {
1342 struct timespec64 ts
;
1344 tk
->xtime_sec
+= leap
;
1348 tk_set_wall_to_mono(tk
,
1349 timespec64_sub(tk
->wall_to_monotonic
, ts
));
1351 __timekeeping_set_tai_offset(tk
, tk
->tai_offset
- leap
);
1353 clock_set
= TK_CLOCK_WAS_SET
;
1360 * logarithmic_accumulation - shifted accumulation of cycles
1362 * This functions accumulates a shifted interval of cycles into
1363 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1366 * Returns the unconsumed cycles.
1368 static cycle_t
logarithmic_accumulation(struct timekeeper
*tk
, cycle_t offset
,
1370 unsigned int *clock_set
)
1372 cycle_t interval
= tk
->cycle_interval
<< shift
;
1375 /* If the offset is smaller then a shifted interval, do nothing */
1376 if (offset
< interval
)
1379 /* Accumulate one shifted interval */
1381 tk
->cycle_last
+= interval
;
1383 tk
->xtime_nsec
+= tk
->xtime_interval
<< shift
;
1384 *clock_set
|= accumulate_nsecs_to_secs(tk
);
1386 /* Accumulate raw time */
1387 raw_nsecs
= (u64
)tk
->raw_interval
<< shift
;
1388 raw_nsecs
+= tk
->raw_time
.tv_nsec
;
1389 if (raw_nsecs
>= NSEC_PER_SEC
) {
1390 u64 raw_secs
= raw_nsecs
;
1391 raw_nsecs
= do_div(raw_secs
, NSEC_PER_SEC
);
1392 tk
->raw_time
.tv_sec
+= raw_secs
;
1394 tk
->raw_time
.tv_nsec
= raw_nsecs
;
1396 /* Accumulate error between NTP and clock interval */
1397 tk
->ntp_error
+= ntp_tick_length() << shift
;
1398 tk
->ntp_error
-= (tk
->xtime_interval
+ tk
->xtime_remainder
) <<
1399 (tk
->ntp_error_shift
+ shift
);
1405 * update_wall_time - Uses the current clocksource to increment the wall time
1408 void update_wall_time(void)
1410 struct clocksource
*clock
;
1411 struct timekeeper
*real_tk
= &tk_core
.timekeeper
;
1412 struct timekeeper
*tk
= &shadow_timekeeper
;
1414 int shift
= 0, maxshift
;
1415 unsigned int clock_set
= 0;
1416 unsigned long flags
;
1418 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1420 /* Make sure we're fully resumed: */
1421 if (unlikely(timekeeping_suspended
))
1424 clock
= real_tk
->clock
;
1426 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
1427 offset
= real_tk
->cycle_interval
;
1429 offset
= (clock
->read(clock
) - clock
->cycle_last
) & clock
->mask
;
1432 /* Check if there's really nothing to do */
1433 if (offset
< real_tk
->cycle_interval
)
1437 * With NO_HZ we may have to accumulate many cycle_intervals
1438 * (think "ticks") worth of time at once. To do this efficiently,
1439 * we calculate the largest doubling multiple of cycle_intervals
1440 * that is smaller than the offset. We then accumulate that
1441 * chunk in one go, and then try to consume the next smaller
1444 shift
= ilog2(offset
) - ilog2(tk
->cycle_interval
);
1445 shift
= max(0, shift
);
1446 /* Bound shift to one less than what overflows tick_length */
1447 maxshift
= (64 - (ilog2(ntp_tick_length())+1)) - 1;
1448 shift
= min(shift
, maxshift
);
1449 while (offset
>= tk
->cycle_interval
) {
1450 offset
= logarithmic_accumulation(tk
, offset
, shift
,
1452 if (offset
< tk
->cycle_interval
<<shift
)
1456 /* correct the clock when NTP error is too big */
1457 timekeeping_adjust(tk
, offset
);
1460 * XXX This can be killed once everyone converts
1461 * to the new update_vsyscall.
1463 old_vsyscall_fixup(tk
);
1466 * Finally, make sure that after the rounding
1467 * xtime_nsec isn't larger than NSEC_PER_SEC
1469 clock_set
|= accumulate_nsecs_to_secs(tk
);
1471 write_seqcount_begin(&tk_core
.seq
);
1472 /* Update clock->cycle_last with the new value */
1473 clock
->cycle_last
= tk
->cycle_last
;
1475 * Update the real timekeeper.
1477 * We could avoid this memcpy by switching pointers, but that
1478 * requires changes to all other timekeeper usage sites as
1479 * well, i.e. move the timekeeper pointer getter into the
1480 * spinlocked/seqcount protected sections. And we trade this
1481 * memcpy under the tk_core.seq against one before we start
1484 memcpy(real_tk
, tk
, sizeof(*tk
));
1485 timekeeping_update(real_tk
, clock_set
);
1486 write_seqcount_end(&tk_core
.seq
);
1488 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1490 /* Have to call _delayed version, since in irq context*/
1491 clock_was_set_delayed();
1495 * getboottime - Return the real time of system boot.
1496 * @ts: pointer to the timespec to be set
1498 * Returns the wall-time of boot in a timespec.
1500 * This is based on the wall_to_monotonic offset and the total suspend
1501 * time. Calls to settimeofday will affect the value returned (which
1502 * basically means that however wrong your real time clock is at boot time,
1503 * you get the right time here).
1505 void getboottime(struct timespec
*ts
)
1507 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1508 struct timespec boottime
= {
1509 .tv_sec
= tk
->wall_to_monotonic
.tv_sec
+
1510 tk
->total_sleep_time
.tv_sec
,
1511 .tv_nsec
= tk
->wall_to_monotonic
.tv_nsec
+
1512 tk
->total_sleep_time
.tv_nsec
1515 set_normalized_timespec(ts
, -boottime
.tv_sec
, -boottime
.tv_nsec
);
1517 EXPORT_SYMBOL_GPL(getboottime
);
1520 * get_monotonic_boottime - Returns monotonic time since boot
1521 * @ts: pointer to the timespec to be set
1523 * Returns the monotonic time since boot in a timespec.
1525 * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also
1526 * includes the time spent in suspend.
1528 void get_monotonic_boottime(struct timespec
*ts
)
1530 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1531 struct timespec64 tomono
, sleep
, ret
;
1535 WARN_ON(timekeeping_suspended
);
1538 seq
= read_seqcount_begin(&tk_core
.seq
);
1539 ret
.tv_sec
= tk
->xtime_sec
;
1540 nsec
= timekeeping_get_ns(tk
);
1541 tomono
= tk
->wall_to_monotonic
;
1542 sleep
= tk
->total_sleep_time
;
1544 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1546 ret
.tv_sec
+= tomono
.tv_sec
+ sleep
.tv_sec
;
1548 timespec64_add_ns(&ret
, nsec
+ tomono
.tv_nsec
+ sleep
.tv_nsec
);
1549 *ts
= timespec64_to_timespec(ret
);
1551 EXPORT_SYMBOL_GPL(get_monotonic_boottime
);
1554 * monotonic_to_bootbased - Convert the monotonic time to boot based.
1555 * @ts: pointer to the timespec to be converted
1557 void monotonic_to_bootbased(struct timespec
*ts
)
1559 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1560 struct timespec64 ts64
;
1562 ts64
= timespec_to_timespec64(*ts
);
1563 ts64
= timespec64_add(ts64
, tk
->total_sleep_time
);
1564 *ts
= timespec64_to_timespec(ts64
);
1566 EXPORT_SYMBOL_GPL(monotonic_to_bootbased
);
1568 unsigned long get_seconds(void)
1570 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1572 return tk
->xtime_sec
;
1574 EXPORT_SYMBOL(get_seconds
);
1576 struct timespec
__current_kernel_time(void)
1578 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1580 return timespec64_to_timespec(tk_xtime(tk
));
1583 struct timespec
current_kernel_time(void)
1585 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1586 struct timespec64 now
;
1590 seq
= read_seqcount_begin(&tk_core
.seq
);
1593 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1595 return timespec64_to_timespec(now
);
1597 EXPORT_SYMBOL(current_kernel_time
);
1599 struct timespec
get_monotonic_coarse(void)
1601 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1602 struct timespec64 now
, mono
;
1606 seq
= read_seqcount_begin(&tk_core
.seq
);
1609 mono
= tk
->wall_to_monotonic
;
1610 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1612 set_normalized_timespec64(&now
, now
.tv_sec
+ mono
.tv_sec
,
1613 now
.tv_nsec
+ mono
.tv_nsec
);
1615 return timespec64_to_timespec(now
);
1619 * Must hold jiffies_lock
1621 void do_timer(unsigned long ticks
)
1623 jiffies_64
+= ticks
;
1624 calc_global_load(ticks
);
1628 * ktime_get_update_offsets_tick - hrtimer helper
1629 * @offs_real: pointer to storage for monotonic -> realtime offset
1630 * @offs_boot: pointer to storage for monotonic -> boottime offset
1631 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1633 * Returns monotonic time at last tick and various offsets
1635 ktime_t
ktime_get_update_offsets_tick(ktime_t
*offs_real
, ktime_t
*offs_boot
,
1638 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1644 seq
= read_seqcount_begin(&tk_core
.seq
);
1646 base
= tk
->base_mono
;
1647 nsecs
= tk
->xtime_nsec
>> tk
->shift
;
1649 *offs_real
= tk
->offs_real
;
1650 *offs_boot
= tk
->offs_boot
;
1651 *offs_tai
= tk
->offs_tai
;
1652 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1654 return ktime_add_ns(base
, nsecs
);
1657 #ifdef CONFIG_HIGH_RES_TIMERS
1659 * ktime_get_update_offsets_now - hrtimer helper
1660 * @offs_real: pointer to storage for monotonic -> realtime offset
1661 * @offs_boot: pointer to storage for monotonic -> boottime offset
1662 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1664 * Returns current monotonic time and updates the offsets
1665 * Called from hrtimer_interrupt() or retrigger_next_event()
1667 ktime_t
ktime_get_update_offsets_now(ktime_t
*offs_real
, ktime_t
*offs_boot
,
1670 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1676 seq
= read_seqcount_begin(&tk_core
.seq
);
1678 base
= tk
->base_mono
;
1679 nsecs
= timekeeping_get_ns(tk
);
1681 *offs_real
= tk
->offs_real
;
1682 *offs_boot
= tk
->offs_boot
;
1683 *offs_tai
= tk
->offs_tai
;
1684 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1686 return ktime_add_ns(base
, nsecs
);
1691 * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
1693 ktime_t
ktime_get_monotonic_offset(void)
1695 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1697 struct timespec64 wtom
;
1700 seq
= read_seqcount_begin(&tk_core
.seq
);
1701 wtom
= tk
->wall_to_monotonic
;
1702 } while (read_seqcount_retry(&tk_core
.seq
, seq
));
1704 return timespec64_to_ktime(wtom
);
1706 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset
);
1709 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1711 int do_adjtimex(struct timex
*txc
)
1713 struct timekeeper
*tk
= &tk_core
.timekeeper
;
1714 unsigned long flags
;
1715 struct timespec64 ts
;
1719 /* Validate the data before disabling interrupts */
1720 ret
= ntp_validate_timex(txc
);
1724 if (txc
->modes
& ADJ_SETOFFSET
) {
1725 struct timespec delta
;
1726 delta
.tv_sec
= txc
->time
.tv_sec
;
1727 delta
.tv_nsec
= txc
->time
.tv_usec
;
1728 if (!(txc
->modes
& ADJ_NANO
))
1729 delta
.tv_nsec
*= 1000;
1730 ret
= timekeeping_inject_offset(&delta
);
1735 getnstimeofday64(&ts
);
1737 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1738 write_seqcount_begin(&tk_core
.seq
);
1740 orig_tai
= tai
= tk
->tai_offset
;
1741 ret
= __do_adjtimex(txc
, &ts
, &tai
);
1743 if (tai
!= orig_tai
) {
1744 __timekeeping_set_tai_offset(tk
, tai
);
1745 timekeeping_update(tk
, TK_MIRROR
| TK_CLOCK_WAS_SET
);
1747 write_seqcount_end(&tk_core
.seq
);
1748 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1750 if (tai
!= orig_tai
)
1753 ntp_notify_cmos_timer();
1758 #ifdef CONFIG_NTP_PPS
1760 * hardpps() - Accessor function to NTP __hardpps function
1762 void hardpps(const struct timespec
*phase_ts
, const struct timespec
*raw_ts
)
1764 unsigned long flags
;
1766 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1767 write_seqcount_begin(&tk_core
.seq
);
1769 __hardpps(phase_ts
, raw_ts
);
1771 write_seqcount_end(&tk_core
.seq
);
1772 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1774 EXPORT_SYMBOL(hardpps
);
1778 * xtime_update() - advances the timekeeping infrastructure
1779 * @ticks: number of ticks, that have elapsed since the last call.
1781 * Must be called with interrupts disabled.
1783 void xtime_update(unsigned long ticks
)
1785 write_seqlock(&jiffies_lock
);
1787 write_sequnlock(&jiffies_lock
);