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>
26 #include "tick-internal.h"
27 #include "ntp_internal.h"
29 static struct timekeeper timekeeper
;
30 static DEFINE_RAW_SPINLOCK(timekeeper_lock
);
31 static seqcount_t timekeeper_seq
;
32 static struct timekeeper shadow_timekeeper
;
34 /* flag for if timekeeping is suspended */
35 int __read_mostly timekeeping_suspended
;
37 /* Flag for if there is a persistent clock on this platform */
38 bool __read_mostly persistent_clock_exist
= false;
40 static inline void tk_normalize_xtime(struct timekeeper
*tk
)
42 while (tk
->xtime_nsec
>= ((u64
)NSEC_PER_SEC
<< tk
->shift
)) {
43 tk
->xtime_nsec
-= (u64
)NSEC_PER_SEC
<< tk
->shift
;
48 static void tk_set_xtime(struct timekeeper
*tk
, const struct timespec
*ts
)
50 tk
->xtime_sec
= ts
->tv_sec
;
51 tk
->xtime_nsec
= (u64
)ts
->tv_nsec
<< tk
->shift
;
54 static void tk_xtime_add(struct timekeeper
*tk
, const struct timespec
*ts
)
56 tk
->xtime_sec
+= ts
->tv_sec
;
57 tk
->xtime_nsec
+= (u64
)ts
->tv_nsec
<< tk
->shift
;
58 tk_normalize_xtime(tk
);
61 static void tk_set_wall_to_mono(struct timekeeper
*tk
, struct timespec wtm
)
66 * Verify consistency of: offset_real = -wall_to_monotonic
67 * before modifying anything
69 set_normalized_timespec(&tmp
, -tk
->wall_to_monotonic
.tv_sec
,
70 -tk
->wall_to_monotonic
.tv_nsec
);
71 WARN_ON_ONCE(tk
->offs_real
.tv64
!= timespec_to_ktime(tmp
).tv64
);
72 tk
->wall_to_monotonic
= wtm
;
73 set_normalized_timespec(&tmp
, -wtm
.tv_sec
, -wtm
.tv_nsec
);
74 tk
->offs_real
= timespec_to_ktime(tmp
);
75 tk
->offs_tai
= ktime_add(tk
->offs_real
, ktime_set(tk
->tai_offset
, 0));
78 static void tk_set_sleep_time(struct timekeeper
*tk
, struct timespec t
)
80 /* Verify consistency before modifying */
81 WARN_ON_ONCE(tk
->offs_boot
.tv64
!= timespec_to_ktime(tk
->total_sleep_time
).tv64
);
83 tk
->total_sleep_time
= t
;
84 tk
->offs_boot
= timespec_to_ktime(t
);
88 * timekeeper_setup_internals - Set up internals to use clocksource clock.
90 * @clock: Pointer to clocksource.
92 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
93 * pair and interval request.
95 * Unless you're the timekeeping code, you should not be using this!
97 static void tk_setup_internals(struct timekeeper
*tk
, struct clocksource
*clock
)
100 u64 tmp
, ntpinterval
;
101 struct clocksource
*old_clock
;
103 old_clock
= tk
->clock
;
105 tk
->cycle_last
= clock
->cycle_last
= clock
->read(clock
);
107 /* Do the ns -> cycle conversion first, using original mult */
108 tmp
= NTP_INTERVAL_LENGTH
;
109 tmp
<<= clock
->shift
;
111 tmp
+= clock
->mult
/2;
112 do_div(tmp
, clock
->mult
);
116 interval
= (cycle_t
) tmp
;
117 tk
->cycle_interval
= interval
;
119 /* Go back from cycles -> shifted ns */
120 tk
->xtime_interval
= (u64
) interval
* clock
->mult
;
121 tk
->xtime_remainder
= ntpinterval
- tk
->xtime_interval
;
123 ((u64
) interval
* clock
->mult
) >> clock
->shift
;
125 /* if changing clocks, convert xtime_nsec shift units */
127 int shift_change
= clock
->shift
- old_clock
->shift
;
128 if (shift_change
< 0)
129 tk
->xtime_nsec
>>= -shift_change
;
131 tk
->xtime_nsec
<<= shift_change
;
133 tk
->shift
= clock
->shift
;
136 tk
->ntp_error_shift
= NTP_SCALE_SHIFT
- clock
->shift
;
139 * The timekeeper keeps its own mult values for the currently
140 * active clocksource. These value will be adjusted via NTP
141 * to counteract clock drifting.
143 tk
->mult
= clock
->mult
;
146 /* Timekeeper helper functions. */
148 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
149 u32 (*arch_gettimeoffset
)(void);
151 u32
get_arch_timeoffset(void)
153 if (likely(arch_gettimeoffset
))
154 return arch_gettimeoffset();
158 static inline u32
get_arch_timeoffset(void) { return 0; }
161 static inline s64
timekeeping_get_ns(struct timekeeper
*tk
)
163 cycle_t cycle_now
, cycle_delta
;
164 struct clocksource
*clock
;
167 /* read clocksource: */
169 cycle_now
= clock
->read(clock
);
171 /* calculate the delta since the last update_wall_time: */
172 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
174 nsec
= cycle_delta
* tk
->mult
+ tk
->xtime_nsec
;
177 /* If arch requires, add in get_arch_timeoffset() */
178 return nsec
+ get_arch_timeoffset();
181 static inline s64
timekeeping_get_ns_raw(struct timekeeper
*tk
)
183 cycle_t cycle_now
, cycle_delta
;
184 struct clocksource
*clock
;
187 /* read clocksource: */
189 cycle_now
= clock
->read(clock
);
191 /* calculate the delta since the last update_wall_time: */
192 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
194 /* convert delta to nanoseconds. */
195 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
197 /* If arch requires, add in get_arch_timeoffset() */
198 return nsec
+ get_arch_timeoffset();
201 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain
);
203 static void update_pvclock_gtod(struct timekeeper
*tk
)
205 raw_notifier_call_chain(&pvclock_gtod_chain
, 0, tk
);
209 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
211 int pvclock_gtod_register_notifier(struct notifier_block
*nb
)
213 struct timekeeper
*tk
= &timekeeper
;
217 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
218 ret
= raw_notifier_chain_register(&pvclock_gtod_chain
, nb
);
219 update_pvclock_gtod(tk
);
220 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
224 EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier
);
227 * pvclock_gtod_unregister_notifier - unregister a pvclock
228 * timedata update listener
230 int pvclock_gtod_unregister_notifier(struct notifier_block
*nb
)
235 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
236 ret
= raw_notifier_chain_unregister(&pvclock_gtod_chain
, nb
);
237 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
241 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier
);
243 /* must hold timekeeper_lock */
244 static void timekeeping_update(struct timekeeper
*tk
, bool clearntp
, bool mirror
)
251 update_pvclock_gtod(tk
);
254 memcpy(&shadow_timekeeper
, &timekeeper
, sizeof(timekeeper
));
258 * timekeeping_forward_now - update clock to the current time
260 * Forward the current clock to update its state since the last call to
261 * update_wall_time(). This is useful before significant clock changes,
262 * as it avoids having to deal with this time offset explicitly.
264 static void timekeeping_forward_now(struct timekeeper
*tk
)
266 cycle_t cycle_now
, cycle_delta
;
267 struct clocksource
*clock
;
271 cycle_now
= clock
->read(clock
);
272 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
273 tk
->cycle_last
= clock
->cycle_last
= cycle_now
;
275 tk
->xtime_nsec
+= cycle_delta
* tk
->mult
;
277 /* If arch requires, add in get_arch_timeoffset() */
278 tk
->xtime_nsec
+= (u64
)get_arch_timeoffset() << tk
->shift
;
280 tk_normalize_xtime(tk
);
282 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
283 timespec_add_ns(&tk
->raw_time
, nsec
);
287 * __getnstimeofday - Returns the time of day in a timespec.
288 * @ts: pointer to the timespec to be set
290 * Updates the time of day in the timespec.
291 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
293 int __getnstimeofday(struct timespec
*ts
)
295 struct timekeeper
*tk
= &timekeeper
;
300 seq
= read_seqcount_begin(&timekeeper_seq
);
302 ts
->tv_sec
= tk
->xtime_sec
;
303 nsecs
= timekeeping_get_ns(tk
);
305 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
308 timespec_add_ns(ts
, nsecs
);
311 * Do not bail out early, in case there were callers still using
312 * the value, even in the face of the WARN_ON.
314 if (unlikely(timekeeping_suspended
))
318 EXPORT_SYMBOL(__getnstimeofday
);
321 * getnstimeofday - Returns the time of day in a timespec.
322 * @ts: pointer to the timespec to be set
324 * Returns the time of day in a timespec (WARN if suspended).
326 void getnstimeofday(struct timespec
*ts
)
328 WARN_ON(__getnstimeofday(ts
));
330 EXPORT_SYMBOL(getnstimeofday
);
332 ktime_t
ktime_get(void)
334 struct timekeeper
*tk
= &timekeeper
;
338 WARN_ON(timekeeping_suspended
);
341 seq
= read_seqcount_begin(&timekeeper_seq
);
342 secs
= tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
343 nsecs
= timekeeping_get_ns(tk
) + tk
->wall_to_monotonic
.tv_nsec
;
345 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
347 * Use ktime_set/ktime_add_ns to create a proper ktime on
348 * 32-bit architectures without CONFIG_KTIME_SCALAR.
350 return ktime_add_ns(ktime_set(secs
, 0), nsecs
);
352 EXPORT_SYMBOL_GPL(ktime_get
);
355 * ktime_get_ts - get the monotonic clock in timespec format
356 * @ts: pointer to timespec variable
358 * The function calculates the monotonic clock from the realtime
359 * clock and the wall_to_monotonic offset and stores the result
360 * in normalized timespec format in the variable pointed to by @ts.
362 void ktime_get_ts(struct timespec
*ts
)
364 struct timekeeper
*tk
= &timekeeper
;
365 struct timespec tomono
;
369 WARN_ON(timekeeping_suspended
);
372 seq
= read_seqcount_begin(&timekeeper_seq
);
373 ts
->tv_sec
= tk
->xtime_sec
;
374 nsec
= timekeeping_get_ns(tk
);
375 tomono
= tk
->wall_to_monotonic
;
377 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
379 ts
->tv_sec
+= tomono
.tv_sec
;
381 timespec_add_ns(ts
, nsec
+ tomono
.tv_nsec
);
383 EXPORT_SYMBOL_GPL(ktime_get_ts
);
387 * timekeeping_clocktai - Returns the TAI time of day in a timespec
388 * @ts: pointer to the timespec to be set
390 * Returns the time of day in a timespec.
392 void timekeeping_clocktai(struct timespec
*ts
)
394 struct timekeeper
*tk
= &timekeeper
;
398 WARN_ON(timekeeping_suspended
);
401 seq
= read_seqcount_begin(&timekeeper_seq
);
403 ts
->tv_sec
= tk
->xtime_sec
+ tk
->tai_offset
;
404 nsecs
= timekeeping_get_ns(tk
);
406 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
409 timespec_add_ns(ts
, nsecs
);
412 EXPORT_SYMBOL(timekeeping_clocktai
);
416 * ktime_get_clocktai - Returns the TAI time of day in a ktime
418 * Returns the time of day in a ktime.
420 ktime_t
ktime_get_clocktai(void)
424 timekeeping_clocktai(&ts
);
425 return timespec_to_ktime(ts
);
427 EXPORT_SYMBOL(ktime_get_clocktai
);
429 #ifdef CONFIG_NTP_PPS
432 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
433 * @ts_raw: pointer to the timespec to be set to raw monotonic time
434 * @ts_real: pointer to the timespec to be set to the time of day
436 * This function reads both the time of day and raw monotonic time at the
437 * same time atomically and stores the resulting timestamps in timespec
440 void getnstime_raw_and_real(struct timespec
*ts_raw
, struct timespec
*ts_real
)
442 struct timekeeper
*tk
= &timekeeper
;
444 s64 nsecs_raw
, nsecs_real
;
446 WARN_ON_ONCE(timekeeping_suspended
);
449 seq
= read_seqcount_begin(&timekeeper_seq
);
451 *ts_raw
= tk
->raw_time
;
452 ts_real
->tv_sec
= tk
->xtime_sec
;
453 ts_real
->tv_nsec
= 0;
455 nsecs_raw
= timekeeping_get_ns_raw(tk
);
456 nsecs_real
= timekeeping_get_ns(tk
);
458 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
460 timespec_add_ns(ts_raw
, nsecs_raw
);
461 timespec_add_ns(ts_real
, nsecs_real
);
463 EXPORT_SYMBOL(getnstime_raw_and_real
);
465 #endif /* CONFIG_NTP_PPS */
468 * do_gettimeofday - Returns the time of day in a timeval
469 * @tv: pointer to the timeval to be set
471 * NOTE: Users should be converted to using getnstimeofday()
473 void do_gettimeofday(struct timeval
*tv
)
477 getnstimeofday(&now
);
478 tv
->tv_sec
= now
.tv_sec
;
479 tv
->tv_usec
= now
.tv_nsec
/1000;
481 EXPORT_SYMBOL(do_gettimeofday
);
484 * do_settimeofday - Sets the time of day
485 * @tv: pointer to the timespec variable containing the new time
487 * Sets the time of day to the new time and update NTP and notify hrtimers
489 int do_settimeofday(const struct timespec
*tv
)
491 struct timekeeper
*tk
= &timekeeper
;
492 struct timespec ts_delta
, xt
;
495 if (!timespec_valid_strict(tv
))
498 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
499 write_seqcount_begin(&timekeeper_seq
);
501 timekeeping_forward_now(tk
);
504 ts_delta
.tv_sec
= tv
->tv_sec
- xt
.tv_sec
;
505 ts_delta
.tv_nsec
= tv
->tv_nsec
- xt
.tv_nsec
;
507 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, ts_delta
));
509 tk_set_xtime(tk
, tv
);
511 timekeeping_update(tk
, true, true);
513 write_seqcount_end(&timekeeper_seq
);
514 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
516 /* signal hrtimers about time change */
521 EXPORT_SYMBOL(do_settimeofday
);
524 * timekeeping_inject_offset - Adds or subtracts from the current time.
525 * @tv: pointer to the timespec variable containing the offset
527 * Adds or subtracts an offset value from the current time.
529 int timekeeping_inject_offset(struct timespec
*ts
)
531 struct timekeeper
*tk
= &timekeeper
;
536 if ((unsigned long)ts
->tv_nsec
>= NSEC_PER_SEC
)
539 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
540 write_seqcount_begin(&timekeeper_seq
);
542 timekeeping_forward_now(tk
);
544 /* Make sure the proposed value is valid */
545 tmp
= timespec_add(tk_xtime(tk
), *ts
);
546 if (!timespec_valid_strict(&tmp
)) {
551 tk_xtime_add(tk
, ts
);
552 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, *ts
));
554 error
: /* even if we error out, we forwarded the time, so call update */
555 timekeeping_update(tk
, true, true);
557 write_seqcount_end(&timekeeper_seq
);
558 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
560 /* signal hrtimers about time change */
565 EXPORT_SYMBOL(timekeeping_inject_offset
);
569 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
572 s32
timekeeping_get_tai_offset(void)
574 struct timekeeper
*tk
= &timekeeper
;
579 seq
= read_seqcount_begin(&timekeeper_seq
);
580 ret
= tk
->tai_offset
;
581 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
587 * __timekeeping_set_tai_offset - Lock free worker function
590 static void __timekeeping_set_tai_offset(struct timekeeper
*tk
, s32 tai_offset
)
592 tk
->tai_offset
= tai_offset
;
593 tk
->offs_tai
= ktime_add(tk
->offs_real
, ktime_set(tai_offset
, 0));
597 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
600 void timekeeping_set_tai_offset(s32 tai_offset
)
602 struct timekeeper
*tk
= &timekeeper
;
605 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
606 write_seqcount_begin(&timekeeper_seq
);
607 __timekeeping_set_tai_offset(tk
, tai_offset
);
608 timekeeping_update(tk
, false, true);
609 write_seqcount_end(&timekeeper_seq
);
610 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
615 * change_clocksource - Swaps clocksources if a new one is available
617 * Accumulates current time interval and initializes new clocksource
619 static int change_clocksource(void *data
)
621 struct timekeeper
*tk
= &timekeeper
;
622 struct clocksource
*new, *old
;
625 new = (struct clocksource
*) data
;
627 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
628 write_seqcount_begin(&timekeeper_seq
);
630 timekeeping_forward_now(tk
);
631 if (!new->enable
|| new->enable(new) == 0) {
633 tk_setup_internals(tk
, new);
637 timekeeping_update(tk
, true, true);
639 write_seqcount_end(&timekeeper_seq
);
640 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
646 * timekeeping_notify - Install a new clock source
647 * @clock: pointer to the clock source
649 * This function is called from clocksource.c after a new, better clock
650 * source has been registered. The caller holds the clocksource_mutex.
652 void timekeeping_notify(struct clocksource
*clock
)
654 struct timekeeper
*tk
= &timekeeper
;
656 if (tk
->clock
== clock
)
658 stop_machine(change_clocksource
, clock
, NULL
);
663 * ktime_get_real - get the real (wall-) time in ktime_t format
665 * returns the time in ktime_t format
667 ktime_t
ktime_get_real(void)
671 getnstimeofday(&now
);
673 return timespec_to_ktime(now
);
675 EXPORT_SYMBOL_GPL(ktime_get_real
);
678 * getrawmonotonic - Returns the raw monotonic time in a timespec
679 * @ts: pointer to the timespec to be set
681 * Returns the raw monotonic time (completely un-modified by ntp)
683 void getrawmonotonic(struct timespec
*ts
)
685 struct timekeeper
*tk
= &timekeeper
;
690 seq
= read_seqcount_begin(&timekeeper_seq
);
691 nsecs
= timekeeping_get_ns_raw(tk
);
694 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
696 timespec_add_ns(ts
, nsecs
);
698 EXPORT_SYMBOL(getrawmonotonic
);
701 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
703 int timekeeping_valid_for_hres(void)
705 struct timekeeper
*tk
= &timekeeper
;
710 seq
= read_seqcount_begin(&timekeeper_seq
);
712 ret
= tk
->clock
->flags
& CLOCK_SOURCE_VALID_FOR_HRES
;
714 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
720 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
722 u64
timekeeping_max_deferment(void)
724 struct timekeeper
*tk
= &timekeeper
;
729 seq
= read_seqcount_begin(&timekeeper_seq
);
731 ret
= tk
->clock
->max_idle_ns
;
733 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
739 * read_persistent_clock - Return time from the persistent clock.
741 * Weak dummy function for arches that do not yet support it.
742 * Reads the time from the battery backed persistent clock.
743 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
745 * XXX - Do be sure to remove it once all arches implement it.
747 void __attribute__((weak
)) read_persistent_clock(struct timespec
*ts
)
754 * read_boot_clock - Return time of the system start.
756 * Weak dummy function for arches that do not yet support it.
757 * Function to read the exact time the system has been started.
758 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
760 * XXX - Do be sure to remove it once all arches implement it.
762 void __attribute__((weak
)) read_boot_clock(struct timespec
*ts
)
769 * timekeeping_init - Initializes the clocksource and common timekeeping values
771 void __init
timekeeping_init(void)
773 struct timekeeper
*tk
= &timekeeper
;
774 struct clocksource
*clock
;
776 struct timespec now
, boot
, tmp
;
778 read_persistent_clock(&now
);
780 if (!timespec_valid_strict(&now
)) {
781 pr_warn("WARNING: Persistent clock returned invalid value!\n"
782 " Check your CMOS/BIOS settings.\n");
785 } else if (now
.tv_sec
|| now
.tv_nsec
)
786 persistent_clock_exist
= true;
788 read_boot_clock(&boot
);
789 if (!timespec_valid_strict(&boot
)) {
790 pr_warn("WARNING: Boot clock returned invalid value!\n"
791 " Check your CMOS/BIOS settings.\n");
796 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
797 write_seqcount_begin(&timekeeper_seq
);
800 clock
= clocksource_default_clock();
802 clock
->enable(clock
);
803 tk_setup_internals(tk
, clock
);
805 tk_set_xtime(tk
, &now
);
806 tk
->raw_time
.tv_sec
= 0;
807 tk
->raw_time
.tv_nsec
= 0;
808 if (boot
.tv_sec
== 0 && boot
.tv_nsec
== 0)
811 set_normalized_timespec(&tmp
, -boot
.tv_sec
, -boot
.tv_nsec
);
812 tk_set_wall_to_mono(tk
, tmp
);
816 tk_set_sleep_time(tk
, tmp
);
818 memcpy(&shadow_timekeeper
, &timekeeper
, sizeof(timekeeper
));
820 write_seqcount_end(&timekeeper_seq
);
821 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
824 /* time in seconds when suspend began */
825 static struct timespec timekeeping_suspend_time
;
828 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
829 * @delta: pointer to a timespec delta value
831 * Takes a timespec offset measuring a suspend interval and properly
832 * adds the sleep offset to the timekeeping variables.
834 static void __timekeeping_inject_sleeptime(struct timekeeper
*tk
,
835 struct timespec
*delta
)
837 if (!timespec_valid_strict(delta
)) {
838 printk(KERN_WARNING
"__timekeeping_inject_sleeptime: Invalid "
839 "sleep delta value!\n");
842 tk_xtime_add(tk
, delta
);
843 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, *delta
));
844 tk_set_sleep_time(tk
, timespec_add(tk
->total_sleep_time
, *delta
));
848 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
849 * @delta: pointer to a timespec delta value
851 * This hook is for architectures that cannot support read_persistent_clock
852 * because their RTC/persistent clock is only accessible when irqs are enabled.
854 * This function should only be called by rtc_resume(), and allows
855 * a suspend offset to be injected into the timekeeping values.
857 void timekeeping_inject_sleeptime(struct timespec
*delta
)
859 struct timekeeper
*tk
= &timekeeper
;
863 * Make sure we don't set the clock twice, as timekeeping_resume()
866 if (has_persistent_clock())
869 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
870 write_seqcount_begin(&timekeeper_seq
);
872 timekeeping_forward_now(tk
);
874 __timekeeping_inject_sleeptime(tk
, delta
);
876 timekeeping_update(tk
, true, true);
878 write_seqcount_end(&timekeeper_seq
);
879 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
881 /* signal hrtimers about time change */
886 * timekeeping_resume - Resumes the generic timekeeping subsystem.
888 * This is for the generic clocksource timekeeping.
889 * xtime/wall_to_monotonic/jiffies/etc are
890 * still managed by arch specific suspend/resume code.
892 static void timekeeping_resume(void)
894 struct timekeeper
*tk
= &timekeeper
;
895 struct clocksource
*clock
= tk
->clock
;
897 struct timespec ts_new
, ts_delta
;
898 cycle_t cycle_now
, cycle_delta
;
899 bool suspendtime_found
= false;
901 read_persistent_clock(&ts_new
);
903 clockevents_resume();
904 clocksource_resume();
906 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
907 write_seqcount_begin(&timekeeper_seq
);
910 * After system resumes, we need to calculate the suspended time and
911 * compensate it for the OS time. There are 3 sources that could be
912 * used: Nonstop clocksource during suspend, persistent clock and rtc
915 * One specific platform may have 1 or 2 or all of them, and the
916 * preference will be:
917 * suspend-nonstop clocksource -> persistent clock -> rtc
918 * The less preferred source will only be tried if there is no better
919 * usable source. The rtc part is handled separately in rtc core code.
921 cycle_now
= clock
->read(clock
);
922 if ((clock
->flags
& CLOCK_SOURCE_SUSPEND_NONSTOP
) &&
923 cycle_now
> clock
->cycle_last
) {
924 u64 num
, max
= ULLONG_MAX
;
925 u32 mult
= clock
->mult
;
926 u32 shift
= clock
->shift
;
929 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
932 * "cycle_delta * mutl" may cause 64 bits overflow, if the
933 * suspended time is too long. In that case we need do the
934 * 64 bits math carefully
937 if (cycle_delta
> max
) {
938 num
= div64_u64(cycle_delta
, max
);
939 nsec
= (((u64
) max
* mult
) >> shift
) * num
;
940 cycle_delta
-= num
* max
;
942 nsec
+= ((u64
) cycle_delta
* mult
) >> shift
;
944 ts_delta
= ns_to_timespec(nsec
);
945 suspendtime_found
= true;
946 } else if (timespec_compare(&ts_new
, &timekeeping_suspend_time
) > 0) {
947 ts_delta
= timespec_sub(ts_new
, timekeeping_suspend_time
);
948 suspendtime_found
= true;
951 if (suspendtime_found
)
952 __timekeeping_inject_sleeptime(tk
, &ts_delta
);
954 /* Re-base the last cycle value */
955 tk
->cycle_last
= clock
->cycle_last
= cycle_now
;
957 timekeeping_suspended
= 0;
958 timekeeping_update(tk
, false, true);
959 write_seqcount_end(&timekeeper_seq
);
960 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
962 touch_softlockup_watchdog();
964 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME
, NULL
);
966 /* Resume hrtimers */
970 static int timekeeping_suspend(void)
972 struct timekeeper
*tk
= &timekeeper
;
974 struct timespec delta
, delta_delta
;
975 static struct timespec old_delta
;
977 read_persistent_clock(&timekeeping_suspend_time
);
980 * On some systems the persistent_clock can not be detected at
981 * timekeeping_init by its return value, so if we see a valid
982 * value returned, update the persistent_clock_exists flag.
984 if (timekeeping_suspend_time
.tv_sec
|| timekeeping_suspend_time
.tv_nsec
)
985 persistent_clock_exist
= true;
987 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
988 write_seqcount_begin(&timekeeper_seq
);
989 timekeeping_forward_now(tk
);
990 timekeeping_suspended
= 1;
993 * To avoid drift caused by repeated suspend/resumes,
994 * which each can add ~1 second drift error,
995 * try to compensate so the difference in system time
996 * and persistent_clock time stays close to constant.
998 delta
= timespec_sub(tk_xtime(tk
), timekeeping_suspend_time
);
999 delta_delta
= timespec_sub(delta
, old_delta
);
1000 if (abs(delta_delta
.tv_sec
) >= 2) {
1002 * if delta_delta is too large, assume time correction
1003 * has occured and set old_delta to the current delta.
1007 /* Otherwise try to adjust old_system to compensate */
1008 timekeeping_suspend_time
=
1009 timespec_add(timekeeping_suspend_time
, delta_delta
);
1012 timekeeping_update(tk
, false, true);
1013 write_seqcount_end(&timekeeper_seq
);
1014 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1016 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND
, NULL
);
1017 clocksource_suspend();
1018 clockevents_suspend();
1023 /* sysfs resume/suspend bits for timekeeping */
1024 static struct syscore_ops timekeeping_syscore_ops
= {
1025 .resume
= timekeeping_resume
,
1026 .suspend
= timekeeping_suspend
,
1029 static int __init
timekeeping_init_ops(void)
1031 register_syscore_ops(&timekeeping_syscore_ops
);
1035 device_initcall(timekeeping_init_ops
);
1038 * If the error is already larger, we look ahead even further
1039 * to compensate for late or lost adjustments.
1041 static __always_inline
int timekeeping_bigadjust(struct timekeeper
*tk
,
1042 s64 error
, s64
*interval
,
1046 u32 look_ahead
, adj
;
1050 * Use the current error value to determine how much to look ahead.
1051 * The larger the error the slower we adjust for it to avoid problems
1052 * with losing too many ticks, otherwise we would overadjust and
1053 * produce an even larger error. The smaller the adjustment the
1054 * faster we try to adjust for it, as lost ticks can do less harm
1055 * here. This is tuned so that an error of about 1 msec is adjusted
1056 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
1058 error2
= tk
->ntp_error
>> (NTP_SCALE_SHIFT
+ 22 - 2 * SHIFT_HZ
);
1059 error2
= abs(error2
);
1060 for (look_ahead
= 0; error2
> 0; look_ahead
++)
1064 * Now calculate the error in (1 << look_ahead) ticks, but first
1065 * remove the single look ahead already included in the error.
1067 tick_error
= ntp_tick_length() >> (tk
->ntp_error_shift
+ 1);
1068 tick_error
-= tk
->xtime_interval
>> 1;
1069 error
= ((error
- tick_error
) >> look_ahead
) + tick_error
;
1071 /* Finally calculate the adjustment shift value. */
1076 *interval
= -*interval
;
1080 for (adj
= 0; error
> i
; adj
++)
1089 * Adjust the multiplier to reduce the error value,
1090 * this is optimized for the most common adjustments of -1,0,1,
1091 * for other values we can do a bit more work.
1093 static void timekeeping_adjust(struct timekeeper
*tk
, s64 offset
)
1095 s64 error
, interval
= tk
->cycle_interval
;
1099 * The point of this is to check if the error is greater than half
1102 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
1104 * Note we subtract one in the shift, so that error is really error*2.
1105 * This "saves" dividing(shifting) interval twice, but keeps the
1106 * (error > interval) comparison as still measuring if error is
1107 * larger than half an interval.
1109 * Note: It does not "save" on aggravation when reading the code.
1111 error
= tk
->ntp_error
>> (tk
->ntp_error_shift
- 1);
1112 if (error
> interval
) {
1114 * We now divide error by 4(via shift), which checks if
1115 * the error is greater than twice the interval.
1116 * If it is greater, we need a bigadjust, if its smaller,
1117 * we can adjust by 1.
1121 * XXX - In update_wall_time, we round up to the next
1122 * nanosecond, and store the amount rounded up into
1123 * the error. This causes the likely below to be unlikely.
1125 * The proper fix is to avoid rounding up by using
1126 * the high precision tk->xtime_nsec instead of
1127 * xtime.tv_nsec everywhere. Fixing this will take some
1130 if (likely(error
<= interval
))
1133 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1135 if (error
< -interval
) {
1136 /* See comment above, this is just switched for the negative */
1138 if (likely(error
>= -interval
)) {
1140 interval
= -interval
;
1143 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1150 if (unlikely(tk
->clock
->maxadj
&&
1151 (tk
->mult
+ adj
> tk
->clock
->mult
+ tk
->clock
->maxadj
))) {
1152 printk_once(KERN_WARNING
1153 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1154 tk
->clock
->name
, (long)tk
->mult
+ adj
,
1155 (long)tk
->clock
->mult
+ tk
->clock
->maxadj
);
1158 * So the following can be confusing.
1160 * To keep things simple, lets assume adj == 1 for now.
1162 * When adj != 1, remember that the interval and offset values
1163 * have been appropriately scaled so the math is the same.
1165 * The basic idea here is that we're increasing the multiplier
1166 * by one, this causes the xtime_interval to be incremented by
1167 * one cycle_interval. This is because:
1168 * xtime_interval = cycle_interval * mult
1169 * So if mult is being incremented by one:
1170 * xtime_interval = cycle_interval * (mult + 1)
1172 * xtime_interval = (cycle_interval * mult) + cycle_interval
1173 * Which can be shortened to:
1174 * xtime_interval += cycle_interval
1176 * So offset stores the non-accumulated cycles. Thus the current
1177 * time (in shifted nanoseconds) is:
1178 * now = (offset * adj) + xtime_nsec
1179 * Now, even though we're adjusting the clock frequency, we have
1180 * to keep time consistent. In other words, we can't jump back
1181 * in time, and we also want to avoid jumping forward in time.
1183 * So given the same offset value, we need the time to be the same
1184 * both before and after the freq adjustment.
1185 * now = (offset * adj_1) + xtime_nsec_1
1186 * now = (offset * adj_2) + xtime_nsec_2
1188 * (offset * adj_1) + xtime_nsec_1 =
1189 * (offset * adj_2) + xtime_nsec_2
1193 * (offset * adj_1) + xtime_nsec_1 =
1194 * (offset * (adj_1+1)) + xtime_nsec_2
1195 * (offset * adj_1) + xtime_nsec_1 =
1196 * (offset * adj_1) + offset + xtime_nsec_2
1197 * Canceling the sides:
1198 * xtime_nsec_1 = offset + xtime_nsec_2
1200 * xtime_nsec_2 = xtime_nsec_1 - offset
1201 * Which simplfies to:
1202 * xtime_nsec -= offset
1204 * XXX - TODO: Doc ntp_error calculation.
1207 tk
->xtime_interval
+= interval
;
1208 tk
->xtime_nsec
-= offset
;
1209 tk
->ntp_error
-= (interval
- offset
) << tk
->ntp_error_shift
;
1213 * It may be possible that when we entered this function, xtime_nsec
1214 * was very small. Further, if we're slightly speeding the clocksource
1215 * in the code above, its possible the required corrective factor to
1216 * xtime_nsec could cause it to underflow.
1218 * Now, since we already accumulated the second, cannot simply roll
1219 * the accumulated second back, since the NTP subsystem has been
1220 * notified via second_overflow. So instead we push xtime_nsec forward
1221 * by the amount we underflowed, and add that amount into the error.
1223 * We'll correct this error next time through this function, when
1224 * xtime_nsec is not as small.
1226 if (unlikely((s64
)tk
->xtime_nsec
< 0)) {
1227 s64 neg
= -(s64
)tk
->xtime_nsec
;
1229 tk
->ntp_error
+= neg
<< tk
->ntp_error_shift
;
1235 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1237 * Helper function that accumulates a the nsecs greater then a second
1238 * from the xtime_nsec field to the xtime_secs field.
1239 * It also calls into the NTP code to handle leapsecond processing.
1242 static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper
*tk
)
1244 u64 nsecps
= (u64
)NSEC_PER_SEC
<< tk
->shift
;
1245 unsigned int clock_set
= 0;
1247 while (tk
->xtime_nsec
>= nsecps
) {
1250 tk
->xtime_nsec
-= nsecps
;
1253 /* Figure out if its a leap sec and apply if needed */
1254 leap
= second_overflow(tk
->xtime_sec
);
1255 if (unlikely(leap
)) {
1258 tk
->xtime_sec
+= leap
;
1262 tk_set_wall_to_mono(tk
,
1263 timespec_sub(tk
->wall_to_monotonic
, ts
));
1265 __timekeeping_set_tai_offset(tk
, tk
->tai_offset
- leap
);
1274 * logarithmic_accumulation - shifted accumulation of cycles
1276 * This functions accumulates a shifted interval of cycles into
1277 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1280 * Returns the unconsumed cycles.
1282 static cycle_t
logarithmic_accumulation(struct timekeeper
*tk
, cycle_t offset
,
1284 unsigned int *clock_set
)
1286 cycle_t interval
= tk
->cycle_interval
<< shift
;
1289 /* If the offset is smaller then a shifted interval, do nothing */
1290 if (offset
< interval
)
1293 /* Accumulate one shifted interval */
1295 tk
->cycle_last
+= interval
;
1297 tk
->xtime_nsec
+= tk
->xtime_interval
<< shift
;
1298 *clock_set
|= accumulate_nsecs_to_secs(tk
);
1300 /* Accumulate raw time */
1301 raw_nsecs
= (u64
)tk
->raw_interval
<< shift
;
1302 raw_nsecs
+= tk
->raw_time
.tv_nsec
;
1303 if (raw_nsecs
>= NSEC_PER_SEC
) {
1304 u64 raw_secs
= raw_nsecs
;
1305 raw_nsecs
= do_div(raw_secs
, NSEC_PER_SEC
);
1306 tk
->raw_time
.tv_sec
+= raw_secs
;
1308 tk
->raw_time
.tv_nsec
= raw_nsecs
;
1310 /* Accumulate error between NTP and clock interval */
1311 tk
->ntp_error
+= ntp_tick_length() << shift
;
1312 tk
->ntp_error
-= (tk
->xtime_interval
+ tk
->xtime_remainder
) <<
1313 (tk
->ntp_error_shift
+ shift
);
1318 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
1319 static inline void old_vsyscall_fixup(struct timekeeper
*tk
)
1324 * Store only full nanoseconds into xtime_nsec after rounding
1325 * it up and add the remainder to the error difference.
1326 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
1327 * by truncating the remainder in vsyscalls. However, it causes
1328 * additional work to be done in timekeeping_adjust(). Once
1329 * the vsyscall implementations are converted to use xtime_nsec
1330 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
1331 * users are removed, this can be killed.
1333 remainder
= tk
->xtime_nsec
& ((1ULL << tk
->shift
) - 1);
1334 tk
->xtime_nsec
-= remainder
;
1335 tk
->xtime_nsec
+= 1ULL << tk
->shift
;
1336 tk
->ntp_error
+= remainder
<< tk
->ntp_error_shift
;
1337 tk
->ntp_error
-= (1ULL << tk
->shift
) << tk
->ntp_error_shift
;
1340 #define old_vsyscall_fixup(tk)
1346 * update_wall_time - Uses the current clocksource to increment the wall time
1349 static void update_wall_time(void)
1351 struct clocksource
*clock
;
1352 struct timekeeper
*real_tk
= &timekeeper
;
1353 struct timekeeper
*tk
= &shadow_timekeeper
;
1355 int shift
= 0, maxshift
;
1356 unsigned int clock_set
= 0;
1357 unsigned long flags
;
1359 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1361 /* Make sure we're fully resumed: */
1362 if (unlikely(timekeeping_suspended
))
1365 clock
= real_tk
->clock
;
1367 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
1368 offset
= real_tk
->cycle_interval
;
1370 offset
= (clock
->read(clock
) - clock
->cycle_last
) & clock
->mask
;
1373 /* Check if there's really nothing to do */
1374 if (offset
< real_tk
->cycle_interval
)
1378 * With NO_HZ we may have to accumulate many cycle_intervals
1379 * (think "ticks") worth of time at once. To do this efficiently,
1380 * we calculate the largest doubling multiple of cycle_intervals
1381 * that is smaller than the offset. We then accumulate that
1382 * chunk in one go, and then try to consume the next smaller
1385 shift
= ilog2(offset
) - ilog2(tk
->cycle_interval
);
1386 shift
= max(0, shift
);
1387 /* Bound shift to one less than what overflows tick_length */
1388 maxshift
= (64 - (ilog2(ntp_tick_length())+1)) - 1;
1389 shift
= min(shift
, maxshift
);
1390 while (offset
>= tk
->cycle_interval
) {
1391 offset
= logarithmic_accumulation(tk
, offset
, shift
,
1393 if (offset
< tk
->cycle_interval
<<shift
)
1397 /* correct the clock when NTP error is too big */
1398 timekeeping_adjust(tk
, offset
);
1401 * XXX This can be killed once everyone converts
1402 * to the new update_vsyscall.
1404 old_vsyscall_fixup(tk
);
1407 * Finally, make sure that after the rounding
1408 * xtime_nsec isn't larger than NSEC_PER_SEC
1410 clock_set
|= accumulate_nsecs_to_secs(tk
);
1412 write_seqcount_begin(&timekeeper_seq
);
1413 /* Update clock->cycle_last with the new value */
1414 clock
->cycle_last
= tk
->cycle_last
;
1416 * Update the real timekeeper.
1418 * We could avoid this memcpy by switching pointers, but that
1419 * requires changes to all other timekeeper usage sites as
1420 * well, i.e. move the timekeeper pointer getter into the
1421 * spinlocked/seqcount protected sections. And we trade this
1422 * memcpy under the timekeeper_seq against one before we start
1425 memcpy(real_tk
, tk
, sizeof(*tk
));
1426 timekeeping_update(real_tk
, false, false);
1427 write_seqcount_end(&timekeeper_seq
);
1429 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1431 /* have to call outside the timekeeper_seq */
1432 clock_was_set_delayed();
1437 * getboottime - Return the real time of system boot.
1438 * @ts: pointer to the timespec to be set
1440 * Returns the wall-time of boot in a timespec.
1442 * This is based on the wall_to_monotonic offset and the total suspend
1443 * time. Calls to settimeofday will affect the value returned (which
1444 * basically means that however wrong your real time clock is at boot time,
1445 * you get the right time here).
1447 void getboottime(struct timespec
*ts
)
1449 struct timekeeper
*tk
= &timekeeper
;
1450 struct timespec boottime
= {
1451 .tv_sec
= tk
->wall_to_monotonic
.tv_sec
+
1452 tk
->total_sleep_time
.tv_sec
,
1453 .tv_nsec
= tk
->wall_to_monotonic
.tv_nsec
+
1454 tk
->total_sleep_time
.tv_nsec
1457 set_normalized_timespec(ts
, -boottime
.tv_sec
, -boottime
.tv_nsec
);
1459 EXPORT_SYMBOL_GPL(getboottime
);
1462 * get_monotonic_boottime - Returns monotonic time since boot
1463 * @ts: pointer to the timespec to be set
1465 * Returns the monotonic time since boot in a timespec.
1467 * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also
1468 * includes the time spent in suspend.
1470 void get_monotonic_boottime(struct timespec
*ts
)
1472 struct timekeeper
*tk
= &timekeeper
;
1473 struct timespec tomono
, sleep
;
1477 WARN_ON(timekeeping_suspended
);
1480 seq
= read_seqcount_begin(&timekeeper_seq
);
1481 ts
->tv_sec
= tk
->xtime_sec
;
1482 nsec
= timekeeping_get_ns(tk
);
1483 tomono
= tk
->wall_to_monotonic
;
1484 sleep
= tk
->total_sleep_time
;
1486 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1488 ts
->tv_sec
+= tomono
.tv_sec
+ sleep
.tv_sec
;
1490 timespec_add_ns(ts
, nsec
+ tomono
.tv_nsec
+ sleep
.tv_nsec
);
1492 EXPORT_SYMBOL_GPL(get_monotonic_boottime
);
1495 * ktime_get_boottime - Returns monotonic time since boot in a ktime
1497 * Returns the monotonic time since boot in a ktime
1499 * This is similar to CLOCK_MONTONIC/ktime_get, but also
1500 * includes the time spent in suspend.
1502 ktime_t
ktime_get_boottime(void)
1506 get_monotonic_boottime(&ts
);
1507 return timespec_to_ktime(ts
);
1509 EXPORT_SYMBOL_GPL(ktime_get_boottime
);
1512 * monotonic_to_bootbased - Convert the monotonic time to boot based.
1513 * @ts: pointer to the timespec to be converted
1515 void monotonic_to_bootbased(struct timespec
*ts
)
1517 struct timekeeper
*tk
= &timekeeper
;
1519 *ts
= timespec_add(*ts
, tk
->total_sleep_time
);
1521 EXPORT_SYMBOL_GPL(monotonic_to_bootbased
);
1523 unsigned long get_seconds(void)
1525 struct timekeeper
*tk
= &timekeeper
;
1527 return tk
->xtime_sec
;
1529 EXPORT_SYMBOL(get_seconds
);
1531 struct timespec
__current_kernel_time(void)
1533 struct timekeeper
*tk
= &timekeeper
;
1535 return tk_xtime(tk
);
1538 struct timespec
current_kernel_time(void)
1540 struct timekeeper
*tk
= &timekeeper
;
1541 struct timespec now
;
1545 seq
= read_seqcount_begin(&timekeeper_seq
);
1548 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1552 EXPORT_SYMBOL(current_kernel_time
);
1554 struct timespec
get_monotonic_coarse(void)
1556 struct timekeeper
*tk
= &timekeeper
;
1557 struct timespec now
, mono
;
1561 seq
= read_seqcount_begin(&timekeeper_seq
);
1564 mono
= tk
->wall_to_monotonic
;
1565 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1567 set_normalized_timespec(&now
, now
.tv_sec
+ mono
.tv_sec
,
1568 now
.tv_nsec
+ mono
.tv_nsec
);
1573 * Must hold jiffies_lock
1575 void do_timer(unsigned long ticks
)
1577 jiffies_64
+= ticks
;
1579 calc_global_load(ticks
);
1583 * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic,
1584 * and sleep offsets.
1585 * @xtim: pointer to timespec to be set with xtime
1586 * @wtom: pointer to timespec to be set with wall_to_monotonic
1587 * @sleep: pointer to timespec to be set with time in suspend
1589 void get_xtime_and_monotonic_and_sleep_offset(struct timespec
*xtim
,
1590 struct timespec
*wtom
, struct timespec
*sleep
)
1592 struct timekeeper
*tk
= &timekeeper
;
1596 seq
= read_seqcount_begin(&timekeeper_seq
);
1597 *xtim
= tk_xtime(tk
);
1598 *wtom
= tk
->wall_to_monotonic
;
1599 *sleep
= tk
->total_sleep_time
;
1600 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1603 #ifdef CONFIG_HIGH_RES_TIMERS
1605 * ktime_get_update_offsets - hrtimer helper
1606 * @offs_real: pointer to storage for monotonic -> realtime offset
1607 * @offs_boot: pointer to storage for monotonic -> boottime offset
1609 * Returns current monotonic time and updates the offsets
1610 * Called from hrtimer_interupt() or retrigger_next_event()
1612 ktime_t
ktime_get_update_offsets(ktime_t
*offs_real
, ktime_t
*offs_boot
,
1615 struct timekeeper
*tk
= &timekeeper
;
1621 seq
= read_seqcount_begin(&timekeeper_seq
);
1623 secs
= tk
->xtime_sec
;
1624 nsecs
= timekeeping_get_ns(tk
);
1626 *offs_real
= tk
->offs_real
;
1627 *offs_boot
= tk
->offs_boot
;
1628 *offs_tai
= tk
->offs_tai
;
1629 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1631 now
= ktime_add_ns(ktime_set(secs
, 0), nsecs
);
1632 now
= ktime_sub(now
, *offs_real
);
1638 * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
1640 ktime_t
ktime_get_monotonic_offset(void)
1642 struct timekeeper
*tk
= &timekeeper
;
1644 struct timespec wtom
;
1647 seq
= read_seqcount_begin(&timekeeper_seq
);
1648 wtom
= tk
->wall_to_monotonic
;
1649 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1651 return timespec_to_ktime(wtom
);
1653 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset
);
1656 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1658 int do_adjtimex(struct timex
*txc
)
1660 struct timekeeper
*tk
= &timekeeper
;
1661 unsigned long flags
;
1666 /* Validate the data before disabling interrupts */
1667 ret
= ntp_validate_timex(txc
);
1671 if (txc
->modes
& ADJ_SETOFFSET
) {
1672 struct timespec delta
;
1673 delta
.tv_sec
= txc
->time
.tv_sec
;
1674 delta
.tv_nsec
= txc
->time
.tv_usec
;
1675 if (!(txc
->modes
& ADJ_NANO
))
1676 delta
.tv_nsec
*= 1000;
1677 ret
= timekeeping_inject_offset(&delta
);
1682 getnstimeofday(&ts
);
1684 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1685 write_seqcount_begin(&timekeeper_seq
);
1687 orig_tai
= tai
= tk
->tai_offset
;
1688 ret
= __do_adjtimex(txc
, &ts
, &tai
);
1690 if (tai
!= orig_tai
) {
1691 __timekeeping_set_tai_offset(tk
, tai
);
1692 timekeeping_update(tk
, false, true);
1694 write_seqcount_end(&timekeeper_seq
);
1695 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1697 if (tai
!= orig_tai
)
1700 ntp_notify_cmos_timer();
1705 #ifdef CONFIG_NTP_PPS
1707 * hardpps() - Accessor function to NTP __hardpps function
1709 void hardpps(const struct timespec
*phase_ts
, const struct timespec
*raw_ts
)
1711 unsigned long flags
;
1713 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1714 write_seqcount_begin(&timekeeper_seq
);
1716 __hardpps(phase_ts
, raw_ts
);
1718 write_seqcount_end(&timekeeper_seq
);
1719 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1721 EXPORT_SYMBOL(hardpps
);
1725 * xtime_update() - advances the timekeeping infrastructure
1726 * @ticks: number of ticks, that have elapsed since the last call.
1728 * Must be called with interrupts disabled.
1730 void xtime_update(unsigned long ticks
)
1732 write_seqlock(&jiffies_lock
);
1734 write_sequnlock(&jiffies_lock
);