1 // SPDX-License-Identifier: GPL-2.0
49  * phase-lock loop variables
82 /* constant (boot-param configurable) NTP tick adjustment (upscaled)	*/
91  * The following variables are used when a pulse-per-second (PPS) signal
142  * pps_clear - Clears the PPS state variables
161 		pps_valid--;  in pps_dec_valid()
195 	txc->ppsfreq	   = shift_right((pps_freq >> PPM_SCALE_INV_SHIFT) *  in pps_fill_timex()
197 	txc->jitter	   = pps_jitter;  in pps_fill_timex()
199 		txc->jitter = pps_jitter / NSEC_PER_USEC;  in pps_fill_timex()
200 	txc->shift	   = pps_shift;  in pps_fill_timex()
201 	txc->stabil	   = pps_stabil;  in pps_fill_timex()
202 	txc->jitcnt	   = pps_jitcnt;  in pps_fill_timex()
203 	txc->calcnt	   = pps_calcnt;  in pps_fill_timex()
204 	txc->errcnt	   = pps_errcnt;  in pps_fill_timex()
205 	txc->stbcnt	   = pps_stbcnt;  in pps_fill_timex()
228 	txc->ppsfreq	   = 0;  in pps_fill_timex()
229 	txc->jitter	   = 0;  in pps_fill_timex()
230 	txc->shift	   = 0;  in pps_fill_timex()
231 	txc->stabil	   = 0;  in pps_fill_timex()
232 	txc->jitcnt	   = 0;  in pps_fill_timex()
233 	txc->calcnt	   = 0;  in pps_fill_timex()
234 	txc->errcnt	   = 0;  in pps_fill_timex()
235 	txc->stbcnt	   = 0;  in pps_fill_timex()
242  * ntp_synced - Returns 1 if the NTP status is not UNSYNC
277 	tick_length		+= new_base - tick_length_base;  in ntp_update_frequency()
293 	return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);  in ntp_update_offset_fll()
307 		offset = clamp(offset, -USEC_PER_SEC, USEC_PER_SEC);  in ntp_update_offset()
315 	offset = clamp(offset, -MAXPHASE, MAXPHASE);  in ntp_update_offset()
321 	secs = (long)(__ktime_get_real_seconds() - time_reftime);  in ntp_update_offset()
339 			(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));  in ntp_update_offset()
343 	time_freq   = max(freq_adj, -MAXFREQ_SCALED);  in ntp_update_offset()
349  * ntp_clear - Clears the NTP state variables
375  * ntp_get_next_leap - Returns the next leapsecond in CLOCK_REALTIME ktime_t
407 	 * Leap second processing. If in leap-insert state at the end of the  in second_overflow()
408 	 * day, the system clock is set back one second; if in leap-delete  in second_overflow()
416 			ntp_next_leap_sec = secs + SECS_PER_DAY - rem;  in second_overflow()
420 			ntp_next_leap_sec = secs + SECS_PER_DAY - rem;  in second_overflow()
428 			leap = -1;  in second_overflow()
468 	time_offset	-= delta;  in second_overflow()
478 		time_adjust -= MAX_TICKADJ;  in second_overflow()
483 	if (time_adjust < -MAX_TICKADJ) {  in second_overflow()
485 		tick_length -= MAX_TICKADJ_SCALED;  in second_overflow()
513 		 * the algorithm is very likely to require a short-sleep retry  in sched_sync_hw_clock()
519 	/* Compute the needed delay that will get to tv_nsec == target_nsec */  in sched_sync_hw_clock()
520 	next.tv_nsec = target_nsec - next.tv_nsec;  in sched_sync_hw_clock()
525 		next.tv_nsec -= NSEC_PER_SEC;  in sched_sync_hw_clock()
545 		adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);  in sync_rtc_clock()
552 	if (rc == -ENODEV)  in sync_rtc_clock()
561 	return -ENODEV;  in update_persistent_clock64()
570 	int rc = -EPROTO;  in sync_cmos_clock()
588 	if (rtc_tv_nsec_ok(-1 * target_nsec, &adjust, &now)) {  in sync_cmos_clock()
590 			adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);  in sync_cmos_clock()
596 		if (rc == -ENODEV) {  in sync_cmos_clock()
636  * Propagate a new txc->status value into the NTP state:
640 	if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {  in process_adj_status()
652 	if (!(time_status & STA_PLL) && (txc->status & STA_PLL))  in process_adj_status()
657 	time_status |= txc->status & ~STA_RONLY;  in process_adj_status()
664 	if (txc->modes & ADJ_STATUS)  in process_adjtimex_modes()
667 	if (txc->modes & ADJ_NANO)  in process_adjtimex_modes()
670 	if (txc->modes & ADJ_MICRO)  in process_adjtimex_modes()
673 	if (txc->modes & ADJ_FREQUENCY) {  in process_adjtimex_modes()
674 		time_freq = txc->freq * PPM_SCALE;  in process_adjtimex_modes()
676 		time_freq = max(time_freq, -MAXFREQ_SCALED);  in process_adjtimex_modes()
681 	if (txc->modes & ADJ_MAXERROR)  in process_adjtimex_modes()
682 		time_maxerror = txc->maxerror;  in process_adjtimex_modes()
684 	if (txc->modes & ADJ_ESTERROR)  in process_adjtimex_modes()
685 		time_esterror = txc->esterror;  in process_adjtimex_modes()
687 	if (txc->modes & ADJ_TIMECONST) {  in process_adjtimex_modes()
688 		time_constant = txc->constant;  in process_adjtimex_modes()
695 	if (txc->modes & ADJ_TAI &&  in process_adjtimex_modes()
696 			txc->constant >= 0 && txc->constant <= MAX_TAI_OFFSET)  in process_adjtimex_modes()
697 		*time_tai = txc->constant;  in process_adjtimex_modes()
699 	if (txc->modes & ADJ_OFFSET)  in process_adjtimex_modes()
700 		ntp_update_offset(txc->offset);  in process_adjtimex_modes()
702 	if (txc->modes & ADJ_TICK)  in process_adjtimex_modes()
703 		tick_usec = txc->tick;  in process_adjtimex_modes()
705 	if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))  in process_adjtimex_modes()
712  * kernel time-keeping variables. used by xntpd.
719 	if (txc->modes & ADJ_ADJTIME) {  in __do_adjtimex()
722 		if (!(txc->modes & ADJ_OFFSET_READONLY)) {  in __do_adjtimex()
724 			time_adjust = txc->offset;  in __do_adjtimex()
730 		txc->offset = save_adjust;  in __do_adjtimex()
733 		if (txc->modes) {  in __do_adjtimex()
749 		txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,  in __do_adjtimex()
752 			txc->offset = (u32)txc->offset / NSEC_PER_USEC;  in __do_adjtimex()
760 	txc->freq	   = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *  in __do_adjtimex()
762 	txc->maxerror	   = time_maxerror;  in __do_adjtimex()
763 	txc->esterror	   = time_esterror;  in __do_adjtimex()
764 	txc->status	   = time_status;  in __do_adjtimex()
765 	txc->constant	   = time_constant;  in __do_adjtimex()
766 	txc->precision	   = 1;  in __do_adjtimex()
767 	txc->tolerance	   = MAXFREQ_SCALED / PPM_SCALE;  in __do_adjtimex()
768 	txc->tick	   = tick_usec;  in __do_adjtimex()
769 	txc->tai	   = *time_tai;  in __do_adjtimex()
774 	txc->time.tv_sec = ts->tv_sec;  in __do_adjtimex()
775 	txc->time.tv_usec = ts->tv_nsec;  in __do_adjtimex()
777 		txc->time.tv_usec = ts->tv_nsec / NSEC_PER_USEC;  in __do_adjtimex()
780 	if (unlikely(ts->tv_sec >= ntp_next_leap_sec)) {  in __do_adjtimex()
783 			txc->tai++;  in __do_adjtimex()
784 			txc->time.tv_sec--;  in __do_adjtimex()
788 			txc->tai--;  in __do_adjtimex()
789 			txc->time.tv_sec++;  in __do_adjtimex()
792 					(ts->tv_sec == ntp_next_leap_sec)) {  in __do_adjtimex()
804  * pps_normtime.nsec has a range of ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ]
812    ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval */
821 		norm.nsec -= NSEC_PER_SEC;  in pps_normalize_ts()
831 	*jitter = pps_tf[0] - pps_tf[1];  in pps_phase_filter_get()
833 		*jitter = -*jitter;  in pps_phase_filter_get()
852 	if (--pps_intcnt <= -PPS_INTCOUNT) {  in pps_dec_freq_interval()
853 		pps_intcnt = -PPS_INTCOUNT;  in pps_dec_freq_interval()
855 			pps_shift--;  in pps_dec_freq_interval()
895 			"hardpps: PPSERROR: interval too long - %lld s\n",  in hardpps_update_freq()
904 	ftemp = div_s64(((s64)(-freq_norm.nsec)) << NTP_SCALE_SHIFT,  in hardpps_update_freq()
906 	delta = shift_right(ftemp - pps_freq, NTP_SCALE_SHIFT);  in hardpps_update_freq()
908 	if (delta > PPS_MAXWANDER || delta < -PPS_MAXWANDER) {  in hardpps_update_freq()
910 				"hardpps: PPSWANDER: change=%ld\n", delta);  in hardpps_update_freq()
924 		delta_mod = -delta_mod;  in hardpps_update_freq()
926 				(NTP_SCALE_SHIFT - SHIFT_USEC),  in hardpps_update_freq()
927 				NSEC_PER_USEC) - pps_stabil) >> PPS_INTMIN;  in hardpps_update_freq()
942 	long correction = -error;  in hardpps_update_phase()
955 				"hardpps: PPSJITTER: jitter=%ld, limit=%ld\n",  in hardpps_update_phase()
967 	pps_jitter += (jitter - pps_jitter) >> PPS_INTMIN;  in hardpps_update_phase()
971  * __hardpps() - discipline CPU clock oscillator to external PPS signal
1006 	 * [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it */  in __hardpps()
1009 			(freq_norm.nsec < -MAXFREQ * freq_norm.sec)) {  in __hardpps()
1013 		printk_deferred(KERN_ERR "hardpps: PPSJITTER: bad pulse\n");  in __hardpps()