xref: /freebsd/sys/kern/kern_ntptime.c (revision f425c1f6319eaa6a8477682567f1f2db5f14ff9f)
1c68996e2SPoul-Henning Kamp /***********************************************************************
23f31c649SGarrett Wollman  *								       *
3f425c1f6SPoul-Henning Kamp  * Copyright (c) David L. Mills 1993-1999			       *
43f31c649SGarrett Wollman  *								       *
5c68996e2SPoul-Henning Kamp  * Permission to use, copy, modify, and distribute this software and   *
6c68996e2SPoul-Henning Kamp  * its documentation for any purpose and without fee is hereby	       *
7c68996e2SPoul-Henning Kamp  * granted, provided that the above copyright notice appears in all    *
8c68996e2SPoul-Henning Kamp  * copies and that both the copyright notice and this permission       *
9c68996e2SPoul-Henning Kamp  * notice appear in supporting documentation, and that the name	       *
10c68996e2SPoul-Henning Kamp  * University of Delaware not be used in advertising or publicity      *
11c68996e2SPoul-Henning Kamp  * pertaining to distribution of the software without specific,	       *
12c68996e2SPoul-Henning Kamp  * written prior permission. The University of Delaware makes no       *
13c68996e2SPoul-Henning Kamp  * representations about the suitability this software for any	       *
14c68996e2SPoul-Henning Kamp  * purpose. It is provided "as is" without express or implied	       *
15c68996e2SPoul-Henning Kamp  * warranty.							       *
163f31c649SGarrett Wollman  *								       *
17c68996e2SPoul-Henning Kamp  **********************************************************************/
183f31c649SGarrett Wollman 
193f31c649SGarrett Wollman /*
20c68996e2SPoul-Henning Kamp  * Adapted from the original sources for FreeBSD and timecounters by:
2132c20357SPoul-Henning Kamp  * Poul-Henning Kamp <phk@FreeBSD.org>.
223f31c649SGarrett Wollman  *
23c68996e2SPoul-Henning Kamp  * The 32bit version of the "LP" macros seems a bit past its "sell by"
24c68996e2SPoul-Henning Kamp  * date so I have retained only the 64bit version and included it directly
25c68996e2SPoul-Henning Kamp  * in this file.
26885bd8e4SJohn Hay  *
27c68996e2SPoul-Henning Kamp  * Only minor changes done to interface with the timecounters over in
28c68996e2SPoul-Henning Kamp  * sys/kern/kern_clock.c.   Some of the comments below may be (even more)
29c68996e2SPoul-Henning Kamp  * confusing and/or plain wrong in that context.
303f31c649SGarrett Wollman  */
31e0d781f3SEivind Eklund 
3232c20357SPoul-Henning Kamp #include "opt_ntp.h"
3332c20357SPoul-Henning Kamp 
343f31c649SGarrett Wollman #include <sys/param.h>
353f31c649SGarrett Wollman #include <sys/systm.h>
36d2d3e875SBruce Evans #include <sys/sysproto.h>
373f31c649SGarrett Wollman #include <sys/kernel.h>
383f31c649SGarrett Wollman #include <sys/proc.h>
39c68996e2SPoul-Henning Kamp #include <sys/time.h>
403f31c649SGarrett Wollman #include <sys/timex.h>
41938ee3ceSPoul-Henning Kamp #include <sys/timepps.h>
423f31c649SGarrett Wollman #include <sys/sysctl.h>
433f31c649SGarrett Wollman 
443f31c649SGarrett Wollman /*
45c68996e2SPoul-Henning Kamp  * Single-precision macros for 64-bit machines
463f31c649SGarrett Wollman  */
47c68996e2SPoul-Henning Kamp typedef long long l_fp;
48c68996e2SPoul-Henning Kamp #define L_ADD(v, u)	((v) += (u))
49c68996e2SPoul-Henning Kamp #define L_SUB(v, u)	((v) -= (u))
50c68996e2SPoul-Henning Kamp #define L_ADDHI(v, a)	((v) += (long long)(a) << 32)
51c68996e2SPoul-Henning Kamp #define L_NEG(v)	((v) = -(v))
52c68996e2SPoul-Henning Kamp #define L_RSHIFT(v, n) \
53c68996e2SPoul-Henning Kamp 	do { \
54c68996e2SPoul-Henning Kamp 		if ((v) < 0) \
55c68996e2SPoul-Henning Kamp 			(v) = -(-(v) >> (n)); \
56c68996e2SPoul-Henning Kamp 		else \
57c68996e2SPoul-Henning Kamp 			(v) = (v) >> (n); \
58c68996e2SPoul-Henning Kamp 	} while (0)
59c68996e2SPoul-Henning Kamp #define L_MPY(v, a)	((v) *= (a))
60c68996e2SPoul-Henning Kamp #define L_CLR(v)	((v) = 0)
61c68996e2SPoul-Henning Kamp #define L_ISNEG(v)	((v) < 0)
62c68996e2SPoul-Henning Kamp #define L_LINT(v, a)	((v) = (long long)(a) << 32)
63c68996e2SPoul-Henning Kamp #define L_GINT(v)	((v) < 0 ? -(-(v) >> 32) : (v) >> 32)
646f70df15SPoul-Henning Kamp 
656f70df15SPoul-Henning Kamp /*
66c68996e2SPoul-Henning Kamp  * Generic NTP kernel interface
676f70df15SPoul-Henning Kamp  *
68c68996e2SPoul-Henning Kamp  * These routines constitute the Network Time Protocol (NTP) interfaces
69c68996e2SPoul-Henning Kamp  * for user and daemon application programs. The ntp_gettime() routine
70c68996e2SPoul-Henning Kamp  * provides the time, maximum error (synch distance) and estimated error
71c68996e2SPoul-Henning Kamp  * (dispersion) to client user application programs. The ntp_adjtime()
72c68996e2SPoul-Henning Kamp  * routine is used by the NTP daemon to adjust the system clock to an
73c68996e2SPoul-Henning Kamp  * externally derived time. The time offset and related variables set by
74c68996e2SPoul-Henning Kamp  * this routine are used by other routines in this module to adjust the
75c68996e2SPoul-Henning Kamp  * phase and frequency of the clock discipline loop which controls the
76c68996e2SPoul-Henning Kamp  * system clock.
776f70df15SPoul-Henning Kamp  *
78f425c1f6SPoul-Henning Kamp  * When the kernel time is reckoned directly in nanoseconds (NTP_NANO
79c68996e2SPoul-Henning Kamp  * defined), the time at each tick interrupt is derived directly from
80c68996e2SPoul-Henning Kamp  * the kernel time variable. When the kernel time is reckoned in
81f425c1f6SPoul-Henning Kamp  * microseconds, (NTP_NANO undefined), the time is derived from the
82f425c1f6SPoul-Henning Kamp  * kernel time variable together with a variable representing the
83f425c1f6SPoul-Henning Kamp  * leftover nanoseconds at the last tick interrupt. In either case, the
84f425c1f6SPoul-Henning Kamp  * current nanosecond time is reckoned from these values plus an
85f425c1f6SPoul-Henning Kamp  * interpolated value derived by the clock routines in another
86f425c1f6SPoul-Henning Kamp  * architecture-specific module. The interpolation can use either a
87f425c1f6SPoul-Henning Kamp  * dedicated counter or a processor cycle counter (PCC) implemented in
88f425c1f6SPoul-Henning Kamp  * some architectures.
896f70df15SPoul-Henning Kamp  *
90c68996e2SPoul-Henning Kamp  * Note that all routines must run at priority splclock or higher.
916f70df15SPoul-Henning Kamp  */
92c68996e2SPoul-Henning Kamp 
93c68996e2SPoul-Henning Kamp /*
94c68996e2SPoul-Henning Kamp  * Phase/frequency-lock loop (PLL/FLL) definitions
95c68996e2SPoul-Henning Kamp  *
96c68996e2SPoul-Henning Kamp  * The nanosecond clock discipline uses two variable types, time
97c68996e2SPoul-Henning Kamp  * variables and frequency variables. Both types are represented as 64-
98c68996e2SPoul-Henning Kamp  * bit fixed-point quantities with the decimal point between two 32-bit
99c68996e2SPoul-Henning Kamp  * halves. On a 32-bit machine, each half is represented as a single
100c68996e2SPoul-Henning Kamp  * word and mathematical operations are done using multiple-precision
101c68996e2SPoul-Henning Kamp  * arithmetic. On a 64-bit machine, ordinary computer arithmetic is
102c68996e2SPoul-Henning Kamp  * used.
103c68996e2SPoul-Henning Kamp  *
104c68996e2SPoul-Henning Kamp  * A time variable is a signed 64-bit fixed-point number in ns and
105c68996e2SPoul-Henning Kamp  * fraction. It represents the remaining time offset to be amortized
106c68996e2SPoul-Henning Kamp  * over succeeding tick interrupts. The maximum time offset is about
107f425c1f6SPoul-Henning Kamp  * 0.5 s and the resolution is about 2.3e-10 ns.
108c68996e2SPoul-Henning Kamp  *
109c68996e2SPoul-Henning Kamp  *			1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
110c68996e2SPoul-Henning Kamp  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
111c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112c68996e2SPoul-Henning Kamp  * |s s s|			 ns				   |
113c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
114c68996e2SPoul-Henning Kamp  * |			    fraction				   |
115c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
116c68996e2SPoul-Henning Kamp  *
117c68996e2SPoul-Henning Kamp  * A frequency variable is a signed 64-bit fixed-point number in ns/s
118c68996e2SPoul-Henning Kamp  * and fraction. It represents the ns and fraction to be added to the
119c68996e2SPoul-Henning Kamp  * kernel time variable at each second. The maximum frequency offset is
120f425c1f6SPoul-Henning Kamp  * about +-500000 ns/s and the resolution is about 2.3e-10 ns/s.
121c68996e2SPoul-Henning Kamp  *
122c68996e2SPoul-Henning Kamp  *			1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
123c68996e2SPoul-Henning Kamp  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
124c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125c68996e2SPoul-Henning Kamp  * |s s s s s s s s s s s s s|	          ns/s			   |
126c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127c68996e2SPoul-Henning Kamp  * |			    fraction				   |
128c68996e2SPoul-Henning Kamp  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
129c68996e2SPoul-Henning Kamp  */
130c68996e2SPoul-Henning Kamp /*
131c68996e2SPoul-Henning Kamp  * The following variables establish the state of the PLL/FLL and the
132c68996e2SPoul-Henning Kamp  * residual time and frequency offset of the local clock.
133c68996e2SPoul-Henning Kamp  */
134c68996e2SPoul-Henning Kamp #define SHIFT_PLL	4		/* PLL loop gain (shift) */
135c68996e2SPoul-Henning Kamp #define SHIFT_FLL	2		/* FLL loop gain (shift) */
136c68996e2SPoul-Henning Kamp 
137c68996e2SPoul-Henning Kamp static int time_state = TIME_OK;	/* clock state */
138c68996e2SPoul-Henning Kamp static int time_status = STA_UNSYNC;	/* clock status bits */
139c68996e2SPoul-Henning Kamp static long time_constant;		/* poll interval (shift) (s) */
140c68996e2SPoul-Henning Kamp static long time_precision = 1;		/* clock precision (ns) */
141c68996e2SPoul-Henning Kamp static long time_maxerror = MAXPHASE / 1000; /* maximum error (us) */
142c68996e2SPoul-Henning Kamp static long time_esterror = MAXPHASE / 1000; /* estimated error (us) */
143c68996e2SPoul-Henning Kamp static long time_reftime;		/* time at last adjustment (s) */
144c68996e2SPoul-Henning Kamp static long time_tick;			/* nanoseconds per tick (ns) */
145c68996e2SPoul-Henning Kamp static l_fp time_offset;		/* time offset (ns) */
146c68996e2SPoul-Henning Kamp static l_fp time_freq;			/* frequency offset (ns/s) */
1473f31c649SGarrett Wollman 
148f425c1f6SPoul-Henning Kamp int ntp_mult;
149f425c1f6SPoul-Henning Kamp int ntp_div;
1503f31c649SGarrett Wollman #ifdef PPS_SYNC
1513f31c649SGarrett Wollman /*
152c68996e2SPoul-Henning Kamp  * The following variables are used when a pulse-per-second (PPS) signal
153c68996e2SPoul-Henning Kamp  * is available and connected via a modem control lead. They establish
154c68996e2SPoul-Henning Kamp  * the engineering parameters of the clock discipline loop when
155c68996e2SPoul-Henning Kamp  * controlled by the PPS signal.
1563f31c649SGarrett Wollman  */
157c68996e2SPoul-Henning Kamp #define PPS_FAVG	2		/* min freq avg interval (s) (shift) */
158f425c1f6SPoul-Henning Kamp #define PPS_FAVGMAX	8		/* max freq avg interval (s) (shift) */
159c68996e2SPoul-Henning Kamp #define PPS_PAVG	4		/* phase avg interval (s) (shift) */
160c68996e2SPoul-Henning Kamp #define PPS_VALID	120		/* PPS signal watchdog max (s) */
161c68996e2SPoul-Henning Kamp #define MAXTIME		500000		/* max PPS error (jitter) (ns) */
162c68996e2SPoul-Henning Kamp #define MAXWANDER	500000		/* max PPS wander (ns/s/s) */
163c68996e2SPoul-Henning Kamp 
164c68996e2SPoul-Henning Kamp struct ppstime {
165c68996e2SPoul-Henning Kamp 	long sec;			/* PPS seconds */
166c68996e2SPoul-Henning Kamp 	long nsec;			/* PPS nanoseconds */
167c68996e2SPoul-Henning Kamp };
168c68996e2SPoul-Henning Kamp static struct ppstime pps_tf[3];	/* phase median filter */
169c68996e2SPoul-Henning Kamp static struct ppstime pps_filt;		/* phase offset */
170c68996e2SPoul-Henning Kamp static l_fp pps_freq;			/* scaled frequency offset (ns/s) */
171c68996e2SPoul-Henning Kamp static long pps_offacc;			/* offset accumulator */
172f425c1f6SPoul-Henning Kamp static long pps_fcount;			/* frequency accumulator */
173c68996e2SPoul-Henning Kamp static long pps_jitter;			/* scaled time dispersion (ns) */
174c68996e2SPoul-Henning Kamp static long pps_stabil;			/* scaled frequency dispersion (ns/s) */
175c68996e2SPoul-Henning Kamp static long pps_lastsec;		/* time at last calibration (s) */
176c68996e2SPoul-Henning Kamp static int pps_valid;			/* signal watchdog counter */
177c68996e2SPoul-Henning Kamp static int pps_shift = PPS_FAVG;	/* interval duration (s) (shift) */
178c68996e2SPoul-Henning Kamp static int pps_intcnt;			/* wander counter */
179c68996e2SPoul-Henning Kamp static int pps_offcnt;			/* offset accumulator counter */
1806f70df15SPoul-Henning Kamp 
1816f70df15SPoul-Henning Kamp /*
1826f70df15SPoul-Henning Kamp  * PPS signal quality monitors
1836f70df15SPoul-Henning Kamp  */
184c68996e2SPoul-Henning Kamp static long pps_calcnt;			/* calibration intervals */
185c68996e2SPoul-Henning Kamp static long pps_jitcnt;			/* jitter limit exceeded */
186c68996e2SPoul-Henning Kamp static long pps_stbcnt;			/* stability limit exceeded */
187c68996e2SPoul-Henning Kamp static long pps_errcnt;			/* calibration errors */
1883f31c649SGarrett Wollman #endif /* PPS_SYNC */
189c68996e2SPoul-Henning Kamp /*
190c68996e2SPoul-Henning Kamp  * End of phase/frequency-lock loop (PLL/FLL) definitions
191c68996e2SPoul-Henning Kamp  */
1923f31c649SGarrett Wollman 
193c68996e2SPoul-Henning Kamp static void ntp_init(void);
194c68996e2SPoul-Henning Kamp static void hardupdate(long offset);
195c68996e2SPoul-Henning Kamp 
196c68996e2SPoul-Henning Kamp /*
197c68996e2SPoul-Henning Kamp  * ntp_gettime() - NTP user application interface
198c68996e2SPoul-Henning Kamp  *
199c68996e2SPoul-Henning Kamp  * See the timex.h header file for synopsis and API description.
200c68996e2SPoul-Henning Kamp  */
201c68996e2SPoul-Henning Kamp static int
202c68996e2SPoul-Henning Kamp ntp_sysctl SYSCTL_HANDLER_ARGS
203c68996e2SPoul-Henning Kamp {
204c68996e2SPoul-Henning Kamp 	struct ntptimeval ntv;	/* temporary structure */
205c68996e2SPoul-Henning Kamp 	struct timespec atv;	/* nanosecond time */
206c68996e2SPoul-Henning Kamp 
207c68996e2SPoul-Henning Kamp 	nanotime(&atv);
208c68996e2SPoul-Henning Kamp 	ntv.time.tv_sec = atv.tv_sec;
209c68996e2SPoul-Henning Kamp 	ntv.time.tv_nsec = atv.tv_nsec;
210c68996e2SPoul-Henning Kamp 	ntv.maxerror = time_maxerror;
211c68996e2SPoul-Henning Kamp 	ntv.esterror = time_esterror;
212c68996e2SPoul-Henning Kamp 	ntv.time_state = time_state;
213c68996e2SPoul-Henning Kamp 
214c68996e2SPoul-Henning Kamp 	/*
215c68996e2SPoul-Henning Kamp 	 * Status word error decode. If any of these conditions occur,
216c68996e2SPoul-Henning Kamp 	 * an error is returned, instead of the status word. Most
217c68996e2SPoul-Henning Kamp 	 * applications will care only about the fact the system clock
218c68996e2SPoul-Henning Kamp 	 * may not be trusted, not about the details.
219c68996e2SPoul-Henning Kamp 	 *
220c68996e2SPoul-Henning Kamp 	 * Hardware or software error
221c68996e2SPoul-Henning Kamp 	 */
222c68996e2SPoul-Henning Kamp 	if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) ||
223c68996e2SPoul-Henning Kamp 
224c68996e2SPoul-Henning Kamp 	/*
225c68996e2SPoul-Henning Kamp 	 * PPS signal lost when either time or frequency synchronization
226c68996e2SPoul-Henning Kamp 	 * requested
227c68996e2SPoul-Henning Kamp 	 */
228c68996e2SPoul-Henning Kamp 	    (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
229c68996e2SPoul-Henning Kamp 	    !(time_status & STA_PPSSIGNAL)) ||
230c68996e2SPoul-Henning Kamp 
231c68996e2SPoul-Henning Kamp 	/*
232c68996e2SPoul-Henning Kamp 	 * PPS jitter exceeded when time synchronization requested
233c68996e2SPoul-Henning Kamp 	 */
234c68996e2SPoul-Henning Kamp 	    (time_status & STA_PPSTIME &&
235c68996e2SPoul-Henning Kamp 	    time_status & STA_PPSJITTER) ||
236c68996e2SPoul-Henning Kamp 
237c68996e2SPoul-Henning Kamp 	/*
238c68996e2SPoul-Henning Kamp 	 * PPS wander exceeded or calibration error when frequency
239c68996e2SPoul-Henning Kamp 	 * synchronization requested
240c68996e2SPoul-Henning Kamp 	 */
241c68996e2SPoul-Henning Kamp 	    (time_status & STA_PPSFREQ &&
242c68996e2SPoul-Henning Kamp 	    time_status & (STA_PPSWANDER | STA_PPSERROR)))
243c68996e2SPoul-Henning Kamp 		ntv.time_state = TIME_ERROR;
244c68996e2SPoul-Henning Kamp 	return (sysctl_handle_opaque(oidp, &ntv, sizeof ntv, req));
245c68996e2SPoul-Henning Kamp }
246c68996e2SPoul-Henning Kamp 
247c68996e2SPoul-Henning Kamp SYSCTL_NODE(_kern, OID_AUTO, ntp_pll, CTLFLAG_RW, 0, "");
248c68996e2SPoul-Henning Kamp SYSCTL_PROC(_kern_ntp_pll, OID_AUTO, gettime, CTLTYPE_OPAQUE|CTLFLAG_RD,
249c68996e2SPoul-Henning Kamp 	0, sizeof(struct ntptimeval) , ntp_sysctl, "S,ntptimeval", "");
250c68996e2SPoul-Henning Kamp 
251f425c1f6SPoul-Henning Kamp SYSCTL_INT(_kern_ntp_pll, OID_AUTO, mult, CTLFLAG_RW, &ntp_mult, 0, "");
252f425c1f6SPoul-Henning Kamp SYSCTL_INT(_kern_ntp_pll, OID_AUTO, div, CTLFLAG_RW, &ntp_div, 0, "");
253c68996e2SPoul-Henning Kamp 
254c68996e2SPoul-Henning Kamp /*
255c68996e2SPoul-Henning Kamp  * ntp_adjtime() - NTP daemon application interface
256c68996e2SPoul-Henning Kamp  *
257c68996e2SPoul-Henning Kamp  * See the timex.h header file for synopsis and API description.
258c68996e2SPoul-Henning Kamp  */
259c68996e2SPoul-Henning Kamp #ifndef _SYS_SYSPROTO_H_
260c68996e2SPoul-Henning Kamp struct ntp_adjtime_args {
261c68996e2SPoul-Henning Kamp 	struct timex *tp;
262c68996e2SPoul-Henning Kamp };
263c68996e2SPoul-Henning Kamp #endif
264c68996e2SPoul-Henning Kamp 
265c68996e2SPoul-Henning Kamp int
266c68996e2SPoul-Henning Kamp ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap)
267c68996e2SPoul-Henning Kamp {
268c68996e2SPoul-Henning Kamp 	struct timex ntv;	/* temporary structure */
269f425c1f6SPoul-Henning Kamp 	long freq;		/* frequency ns/s) */
270c68996e2SPoul-Henning Kamp 	int modes;		/* mode bits from structure */
271c68996e2SPoul-Henning Kamp 	int s;			/* caller priority */
272c68996e2SPoul-Henning Kamp 	int error;
273c68996e2SPoul-Henning Kamp 
274c68996e2SPoul-Henning Kamp 	error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv));
275c68996e2SPoul-Henning Kamp 	if (error)
276c68996e2SPoul-Henning Kamp 		return(error);
277c68996e2SPoul-Henning Kamp 
278c68996e2SPoul-Henning Kamp 	/*
279c68996e2SPoul-Henning Kamp 	 * Update selected clock variables - only the superuser can
280c68996e2SPoul-Henning Kamp 	 * change anything. Note that there is no error checking here on
281c68996e2SPoul-Henning Kamp 	 * the assumption the superuser should know what it is doing.
282c68996e2SPoul-Henning Kamp 	 */
283c68996e2SPoul-Henning Kamp 	modes = ntv.modes;
284fafbe352SPoul-Henning Kamp 	if (modes)
285c68996e2SPoul-Henning Kamp 		error = suser(p->p_cred->pc_ucred, &p->p_acflag);
286c68996e2SPoul-Henning Kamp 	if (error)
287c68996e2SPoul-Henning Kamp 		return (error);
288c68996e2SPoul-Henning Kamp 	s = splclock();
289c68996e2SPoul-Henning Kamp 	if (modes & MOD_FREQUENCY) {
290f425c1f6SPoul-Henning Kamp 		freq = (ntv.freq * 1000) << 16;
291f425c1f6SPoul-Henning Kamp 		if (freq > MAXFREQ)
292f425c1f6SPoul-Henning Kamp 			L_LINT(time_freq, MAXFREQ);
293f425c1f6SPoul-Henning Kamp 		else if (freq < -MAXFREQ)
294f425c1f6SPoul-Henning Kamp 			L_LINT(time_freq, -MAXFREQ);
295f425c1f6SPoul-Henning Kamp 		else
296f425c1f6SPoul-Henning Kamp 			L_LINT(time_freq, freq);
297f425c1f6SPoul-Henning Kamp 
298c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC
299c68996e2SPoul-Henning Kamp 		pps_freq = time_freq;
300c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */
301c68996e2SPoul-Henning Kamp 	}
302c68996e2SPoul-Henning Kamp 	if (modes & MOD_MAXERROR)
303c68996e2SPoul-Henning Kamp 		time_maxerror = ntv.maxerror;
304c68996e2SPoul-Henning Kamp 	if (modes & MOD_ESTERROR)
305c68996e2SPoul-Henning Kamp 		time_esterror = ntv.esterror;
306c68996e2SPoul-Henning Kamp 	if (modes & MOD_STATUS) {
307c68996e2SPoul-Henning Kamp 		time_status &= STA_RONLY;
308c68996e2SPoul-Henning Kamp 		time_status |= ntv.status & ~STA_RONLY;
309c68996e2SPoul-Henning Kamp 	}
310f425c1f6SPoul-Henning Kamp 	if (modes & MOD_TIMECONST) {
311f425c1f6SPoul-Henning Kamp 		if (ntv.constant < 0)
312f425c1f6SPoul-Henning Kamp 			time_constant = 0;
313f425c1f6SPoul-Henning Kamp 		else if (ntv.constant > MAXTC)
314f425c1f6SPoul-Henning Kamp 			time_constant = MAXTC;
315f425c1f6SPoul-Henning Kamp 		else
316c68996e2SPoul-Henning Kamp 			time_constant = ntv.constant;
317f425c1f6SPoul-Henning Kamp 	}
318c68996e2SPoul-Henning Kamp 	if (modes & MOD_NANO)
319c68996e2SPoul-Henning Kamp 		time_status |= STA_NANO;
320c68996e2SPoul-Henning Kamp 	if (modes & MOD_MICRO)
321c68996e2SPoul-Henning Kamp 		time_status &= ~STA_NANO;
322c68996e2SPoul-Henning Kamp 	if (modes & MOD_CLKB)
323c68996e2SPoul-Henning Kamp 		time_status |= STA_CLK;
324c68996e2SPoul-Henning Kamp 	if (modes & MOD_CLKA)
325c68996e2SPoul-Henning Kamp 		time_status &= ~STA_CLK;
326c68996e2SPoul-Henning Kamp 	if (modes & MOD_OFFSET) {
327c68996e2SPoul-Henning Kamp 		if (time_status & STA_NANO)
328c68996e2SPoul-Henning Kamp 			hardupdate(ntv.offset);
329c68996e2SPoul-Henning Kamp 		else
330c68996e2SPoul-Henning Kamp 			hardupdate(ntv.offset * 1000);
331c68996e2SPoul-Henning Kamp 	}
332c68996e2SPoul-Henning Kamp 
333c68996e2SPoul-Henning Kamp 	/*
334c68996e2SPoul-Henning Kamp 	 * Retrieve all clock variables
335c68996e2SPoul-Henning Kamp 	 */
336c68996e2SPoul-Henning Kamp 	if (time_status & STA_NANO)
337c68996e2SPoul-Henning Kamp 		ntv.offset = L_GINT(time_offset);
338c68996e2SPoul-Henning Kamp 	else
339c68996e2SPoul-Henning Kamp 		ntv.offset = L_GINT(time_offset) / 1000;
340f425c1f6SPoul-Henning Kamp 	ntv.freq = L_GINT((time_freq / 1000) << 16);
341c68996e2SPoul-Henning Kamp 	ntv.maxerror = time_maxerror;
342c68996e2SPoul-Henning Kamp 	ntv.esterror = time_esterror;
343c68996e2SPoul-Henning Kamp 	ntv.status = time_status;
344f425c1f6SPoul-Henning Kamp 	ntv.constant = time_constant;
345c68996e2SPoul-Henning Kamp 	if (time_status & STA_NANO)
346c68996e2SPoul-Henning Kamp 		ntv.precision = time_precision;
347c68996e2SPoul-Henning Kamp 	else
348c68996e2SPoul-Henning Kamp 		ntv.precision = time_precision / 1000;
349c68996e2SPoul-Henning Kamp 	ntv.tolerance = MAXFREQ * SCALE_PPM;
350c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC
351c68996e2SPoul-Henning Kamp 	ntv.shift = pps_shift;
352f425c1f6SPoul-Henning Kamp 	ntv.ppsfreq = L_GINT((pps_freq / 1000) << 16);
353c68996e2SPoul-Henning Kamp 	ntv.jitter = pps_jitter;
354c68996e2SPoul-Henning Kamp 	if (time_status & STA_NANO)
355c68996e2SPoul-Henning Kamp 		ntv.jitter = pps_jitter;
356c68996e2SPoul-Henning Kamp 	else
357c68996e2SPoul-Henning Kamp 		ntv.jitter = pps_jitter / 1000;
358c68996e2SPoul-Henning Kamp 	ntv.stabil = pps_stabil;
359c68996e2SPoul-Henning Kamp 	ntv.calcnt = pps_calcnt;
360c68996e2SPoul-Henning Kamp 	ntv.errcnt = pps_errcnt;
361c68996e2SPoul-Henning Kamp 	ntv.jitcnt = pps_jitcnt;
362c68996e2SPoul-Henning Kamp 	ntv.stbcnt = pps_stbcnt;
363c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */
364c68996e2SPoul-Henning Kamp 	splx(s);
365c68996e2SPoul-Henning Kamp 
366c68996e2SPoul-Henning Kamp 	error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv));
367c68996e2SPoul-Henning Kamp 	if (error)
368c68996e2SPoul-Henning Kamp 		return (error);
369c68996e2SPoul-Henning Kamp 
370c68996e2SPoul-Henning Kamp 	/*
371c68996e2SPoul-Henning Kamp 	 * Status word error decode. See comments in
372c68996e2SPoul-Henning Kamp 	 * ntp_gettime() routine.
373c68996e2SPoul-Henning Kamp 	 */
374c68996e2SPoul-Henning Kamp 	if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) ||
375c68996e2SPoul-Henning Kamp 	    (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
376c68996e2SPoul-Henning Kamp 	    !(time_status & STA_PPSSIGNAL)) ||
377c68996e2SPoul-Henning Kamp 	    (time_status & STA_PPSTIME &&
378c68996e2SPoul-Henning Kamp 	    time_status & STA_PPSJITTER) ||
379c68996e2SPoul-Henning Kamp 	    (time_status & STA_PPSFREQ &&
380c68996e2SPoul-Henning Kamp 	    time_status & (STA_PPSWANDER | STA_PPSERROR)))
381c68996e2SPoul-Henning Kamp 		return (TIME_ERROR);
382c68996e2SPoul-Henning Kamp 	return (time_state);
383c68996e2SPoul-Henning Kamp }
384c68996e2SPoul-Henning Kamp 
385c68996e2SPoul-Henning Kamp /*
386c68996e2SPoul-Henning Kamp  * second_overflow() - called after ntp_tick_adjust()
387c68996e2SPoul-Henning Kamp  *
388c68996e2SPoul-Henning Kamp  * This routine is ordinarily called immediately following the above
389c68996e2SPoul-Henning Kamp  * routine ntp_tick_adjust(). While these two routines are normally
390c68996e2SPoul-Henning Kamp  * combined, they are separated here only for the purposes of
391c68996e2SPoul-Henning Kamp  * simulation.
392c68996e2SPoul-Henning Kamp  */
393c68996e2SPoul-Henning Kamp void
394c68996e2SPoul-Henning Kamp ntp_update_second(struct timecounter *tcp)
395c68996e2SPoul-Henning Kamp {
396c68996e2SPoul-Henning Kamp 	u_int32_t *newsec;
39732c20357SPoul-Henning Kamp 	l_fp ftemp, time_adj;		/* 32/64-bit temporaries */
398c68996e2SPoul-Henning Kamp 
399c68996e2SPoul-Henning Kamp 	newsec = &tcp->tc_offset_sec;
400c68996e2SPoul-Henning Kamp 	time_maxerror += MAXFREQ / 1000;
401c68996e2SPoul-Henning Kamp 
402c68996e2SPoul-Henning Kamp 	/*
403c68996e2SPoul-Henning Kamp 	 * Leap second processing. If in leap-insert state at
404c68996e2SPoul-Henning Kamp 	 * the end of the day, the system clock is set back one
405c68996e2SPoul-Henning Kamp 	 * second; if in leap-delete state, the system clock is
406c68996e2SPoul-Henning Kamp 	 * set ahead one second. The nano_time() routine or
407c68996e2SPoul-Henning Kamp 	 * external clock driver will insure that reported time
408c68996e2SPoul-Henning Kamp 	 * is always monotonic.
409c68996e2SPoul-Henning Kamp 	 */
410c68996e2SPoul-Henning Kamp 	switch (time_state) {
411c68996e2SPoul-Henning Kamp 
412c68996e2SPoul-Henning Kamp 		/*
413c68996e2SPoul-Henning Kamp 		 * No warning.
414c68996e2SPoul-Henning Kamp 		 */
415c68996e2SPoul-Henning Kamp 		case TIME_OK:
416c68996e2SPoul-Henning Kamp 		if (time_status & STA_INS)
417c68996e2SPoul-Henning Kamp 			time_state = TIME_INS;
418c68996e2SPoul-Henning Kamp 		else if (time_status & STA_DEL)
419c68996e2SPoul-Henning Kamp 			time_state = TIME_DEL;
420c68996e2SPoul-Henning Kamp 		break;
421c68996e2SPoul-Henning Kamp 
422c68996e2SPoul-Henning Kamp 		/*
423c68996e2SPoul-Henning Kamp 		 * Insert second 23:59:60 following second
424c68996e2SPoul-Henning Kamp 		 * 23:59:59.
425c68996e2SPoul-Henning Kamp 		 */
426c68996e2SPoul-Henning Kamp 		case TIME_INS:
427c68996e2SPoul-Henning Kamp 		if (!(time_status & STA_INS))
428c68996e2SPoul-Henning Kamp 			time_state = TIME_OK;
429c68996e2SPoul-Henning Kamp 		else if ((*newsec) % 86400 == 0) {
430c68996e2SPoul-Henning Kamp 			(*newsec)--;
431c68996e2SPoul-Henning Kamp 			time_state = TIME_OOP;
432c68996e2SPoul-Henning Kamp 		}
433c68996e2SPoul-Henning Kamp 		break;
434c68996e2SPoul-Henning Kamp 
435c68996e2SPoul-Henning Kamp 		/*
436c68996e2SPoul-Henning Kamp 		 * Delete second 23:59:59.
437c68996e2SPoul-Henning Kamp 		 */
438c68996e2SPoul-Henning Kamp 		case TIME_DEL:
439c68996e2SPoul-Henning Kamp 		if (!(time_status & STA_DEL))
440c68996e2SPoul-Henning Kamp 			time_state = TIME_OK;
441c68996e2SPoul-Henning Kamp 		else if (((*newsec) + 1) % 86400 == 0) {
442c68996e2SPoul-Henning Kamp 			(*newsec)++;
443c68996e2SPoul-Henning Kamp 			time_state = TIME_WAIT;
444c68996e2SPoul-Henning Kamp 		}
445c68996e2SPoul-Henning Kamp 		break;
446c68996e2SPoul-Henning Kamp 
447c68996e2SPoul-Henning Kamp 		/*
448c68996e2SPoul-Henning Kamp 		 * Insert second in progress.
449c68996e2SPoul-Henning Kamp 		 */
450c68996e2SPoul-Henning Kamp 		case TIME_OOP:
451c68996e2SPoul-Henning Kamp 		time_state = TIME_WAIT;
452c68996e2SPoul-Henning Kamp 		break;
453c68996e2SPoul-Henning Kamp 
454c68996e2SPoul-Henning Kamp 		/*
455c68996e2SPoul-Henning Kamp 		 * Wait for status bits to clear.
456c68996e2SPoul-Henning Kamp 		 */
457c68996e2SPoul-Henning Kamp 		case TIME_WAIT:
458c68996e2SPoul-Henning Kamp 		if (!(time_status & (STA_INS | STA_DEL)))
459c68996e2SPoul-Henning Kamp 			time_state = TIME_OK;
460c68996e2SPoul-Henning Kamp 	}
461c68996e2SPoul-Henning Kamp 
462c68996e2SPoul-Henning Kamp 	/*
463c68996e2SPoul-Henning Kamp 	 * Compute the total time adjustment for the next
464c68996e2SPoul-Henning Kamp 	 * second in ns. The offset is reduced by a factor
465c68996e2SPoul-Henning Kamp 	 * depending on FLL or PLL mode and whether the PPS
466c68996e2SPoul-Henning Kamp 	 * signal is operating. Note that the value is in effect
467c68996e2SPoul-Henning Kamp 	 * scaled by the clock frequency, since the adjustment
468c68996e2SPoul-Henning Kamp 	 * is added at each tick interrupt.
469c68996e2SPoul-Henning Kamp 	 */
470c68996e2SPoul-Henning Kamp 	ftemp = time_offset;
471c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC
472c68996e2SPoul-Henning Kamp 	if (time_status & STA_PPSTIME && time_status &
473c68996e2SPoul-Henning Kamp 	    STA_PPSSIGNAL)
474c68996e2SPoul-Henning Kamp 		L_RSHIFT(ftemp, PPS_FAVG);
475c68996e2SPoul-Henning Kamp 	else if (time_status & STA_MODE)
476c68996e2SPoul-Henning Kamp #else
477c68996e2SPoul-Henning Kamp 	if (time_status & STA_MODE)
478c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */
479c68996e2SPoul-Henning Kamp 		L_RSHIFT(ftemp, SHIFT_FLL);
480c68996e2SPoul-Henning Kamp 	else
481c68996e2SPoul-Henning Kamp 		L_RSHIFT(ftemp, SHIFT_PLL + time_constant);
482c68996e2SPoul-Henning Kamp 	time_adj = ftemp;
483c68996e2SPoul-Henning Kamp 	L_SUB(time_offset, ftemp);
484c68996e2SPoul-Henning Kamp 	L_ADD(time_adj, time_freq);
485c68996e2SPoul-Henning Kamp 	tcp->tc_adjustment = time_adj;
486c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC
487c68996e2SPoul-Henning Kamp 	if (pps_valid > 0)
488c68996e2SPoul-Henning Kamp 		pps_valid--;
489c68996e2SPoul-Henning Kamp 	else
490c68996e2SPoul-Henning Kamp 		time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
491c68996e2SPoul-Henning Kamp 		    STA_PPSWANDER | STA_PPSERROR);
492c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */
493c68996e2SPoul-Henning Kamp }
494c68996e2SPoul-Henning Kamp 
495c68996e2SPoul-Henning Kamp /*
496c68996e2SPoul-Henning Kamp  * ntp_init() - initialize variables and structures
497c68996e2SPoul-Henning Kamp  *
498c68996e2SPoul-Henning Kamp  * This routine must be called after the kernel variables hz and tick
499c68996e2SPoul-Henning Kamp  * are set or changed and before the next tick interrupt. In this
500c68996e2SPoul-Henning Kamp  * particular implementation, these values are assumed set elsewhere in
501c68996e2SPoul-Henning Kamp  * the kernel. The design allows the clock frequency and tick interval
502c68996e2SPoul-Henning Kamp  * to be changed while the system is running. So, this routine should
503c68996e2SPoul-Henning Kamp  * probably be integrated with the code that does that.
504c68996e2SPoul-Henning Kamp  */
505c68996e2SPoul-Henning Kamp static void
506c68996e2SPoul-Henning Kamp ntp_init()
507c68996e2SPoul-Henning Kamp {
508c68996e2SPoul-Henning Kamp 
509c68996e2SPoul-Henning Kamp 	/*
510c68996e2SPoul-Henning Kamp 	 * The following variable must be initialized any time the
511c68996e2SPoul-Henning Kamp 	 * kernel variable hz is changed.
512c68996e2SPoul-Henning Kamp 	 */
513c68996e2SPoul-Henning Kamp 	time_tick = NANOSECOND / hz;
514c68996e2SPoul-Henning Kamp 
515c68996e2SPoul-Henning Kamp 	/*
516c68996e2SPoul-Henning Kamp 	 * The following variables are initialized only at startup. Only
517c68996e2SPoul-Henning Kamp 	 * those structures not cleared by the compiler need to be
518c68996e2SPoul-Henning Kamp 	 * initialized, and these only in the simulator. In the actual
519c68996e2SPoul-Henning Kamp 	 * kernel, any nonzero values here will quickly evaporate.
520c68996e2SPoul-Henning Kamp 	 */
521c68996e2SPoul-Henning Kamp 	L_CLR(time_offset);
522c68996e2SPoul-Henning Kamp 	L_CLR(time_freq);
523c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC
524884ab557SPoul-Henning Kamp 	pps_filt.sec = pps_filt.nsec = 0;
525c68996e2SPoul-Henning Kamp 	pps_tf[0] = pps_tf[1] = pps_tf[2] = pps_filt;
526f425c1f6SPoul-Henning Kamp 	pps_fcount = 0;
527c68996e2SPoul-Henning Kamp 	L_CLR(pps_freq);
528c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */
529c68996e2SPoul-Henning Kamp }
530c68996e2SPoul-Henning Kamp 
531c68996e2SPoul-Henning Kamp SYSINIT(ntpclocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, ntp_init, NULL)
5326f70df15SPoul-Henning Kamp 
5336f70df15SPoul-Henning Kamp /*
5346f70df15SPoul-Henning Kamp  * hardupdate() - local clock update
5356f70df15SPoul-Henning Kamp  *
5366f70df15SPoul-Henning Kamp  * This routine is called by ntp_adjtime() to update the local clock
5376f70df15SPoul-Henning Kamp  * phase and frequency. The implementation is of an adaptive-parameter,
5386f70df15SPoul-Henning Kamp  * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new
5396f70df15SPoul-Henning Kamp  * time and frequency offset estimates for each call. If the kernel PPS
5406f70df15SPoul-Henning Kamp  * discipline code is configured (PPS_SYNC), the PPS signal itself
5416f70df15SPoul-Henning Kamp  * determines the new time offset, instead of the calling argument.
5426f70df15SPoul-Henning Kamp  * Presumably, calls to ntp_adjtime() occur only when the caller
5436f70df15SPoul-Henning Kamp  * believes the local clock is valid within some bound (+-128 ms with
5446f70df15SPoul-Henning Kamp  * NTP). If the caller's time is far different than the PPS time, an
5456f70df15SPoul-Henning Kamp  * argument will ensue, and it's not clear who will lose.
5466f70df15SPoul-Henning Kamp  *
547c68996e2SPoul-Henning Kamp  * For uncompensated quartz crystal oscillators and nominal update
548c68996e2SPoul-Henning Kamp  * intervals less than 256 s, operation should be in phase-lock mode,
549c68996e2SPoul-Henning Kamp  * where the loop is disciplined to phase. For update intervals greater
550c68996e2SPoul-Henning Kamp  * than 1024 s, operation should be in frequency-lock mode, where the
551c68996e2SPoul-Henning Kamp  * loop is disciplined to frequency. Between 256 s and 1024 s, the mode
552c68996e2SPoul-Henning Kamp  * is selected by the STA_MODE status bit.
5536f70df15SPoul-Henning Kamp  */
5546f70df15SPoul-Henning Kamp static void
555c68996e2SPoul-Henning Kamp hardupdate(offset)
556c68996e2SPoul-Henning Kamp 	long offset;		/* clock offset (ns) */
5576f70df15SPoul-Henning Kamp {
558c68996e2SPoul-Henning Kamp 	long ltemp, mtemp;
559c68996e2SPoul-Henning Kamp 	l_fp ftemp;
5606f70df15SPoul-Henning Kamp 
561c68996e2SPoul-Henning Kamp 	/*
562c68996e2SPoul-Henning Kamp 	 * Select how the phase is to be controlled and from which
563c68996e2SPoul-Henning Kamp 	 * source. If the PPS signal is present and enabled to
564c68996e2SPoul-Henning Kamp 	 * discipline the time, the PPS offset is used; otherwise, the
565c68996e2SPoul-Henning Kamp 	 * argument offset is used.
566c68996e2SPoul-Henning Kamp 	 */
5676f70df15SPoul-Henning Kamp 	ltemp = offset;
568c68996e2SPoul-Henning Kamp 	if (ltemp > MAXPHASE)
569c68996e2SPoul-Henning Kamp 		ltemp = MAXPHASE;
570c68996e2SPoul-Henning Kamp 	else if (ltemp < -MAXPHASE)
571c68996e2SPoul-Henning Kamp 		ltemp = -MAXPHASE;
572c68996e2SPoul-Henning Kamp 	if (!(time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL))
573c68996e2SPoul-Henning Kamp 		L_LINT(time_offset, ltemp);
5746f70df15SPoul-Henning Kamp 
5756f70df15SPoul-Henning Kamp 	/*
576c68996e2SPoul-Henning Kamp 	 * Select how the frequency is to be controlled and in which
577c68996e2SPoul-Henning Kamp 	 * mode (PLL or FLL). If the PPS signal is present and enabled
578c68996e2SPoul-Henning Kamp 	 * to discipline the frequency, the PPS frequency is used;
579c68996e2SPoul-Henning Kamp 	 * otherwise, the argument offset is used to compute it.
5806f70df15SPoul-Henning Kamp 	 */
581c68996e2SPoul-Henning Kamp 	if (time_status & STA_PPSFREQ && time_status & STA_PPSSIGNAL) {
582c68996e2SPoul-Henning Kamp 		time_reftime = time_second;
583c68996e2SPoul-Henning Kamp 		return;
584c68996e2SPoul-Henning Kamp 	}
5856f70df15SPoul-Henning Kamp 	if (time_status & STA_FREQHOLD || time_reftime == 0)
586227ee8a1SPoul-Henning Kamp 		time_reftime = time_second;
587227ee8a1SPoul-Henning Kamp 	mtemp = time_second - time_reftime;
588c68996e2SPoul-Henning Kamp 	if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)
589c68996e2SPoul-Henning Kamp 	    ) {
590c68996e2SPoul-Henning Kamp 		L_LINT(ftemp, (ltemp << 4) / mtemp);
591c68996e2SPoul-Henning Kamp 		L_RSHIFT(ftemp, SHIFT_FLL + 4);
592c68996e2SPoul-Henning Kamp 		L_ADD(time_freq, ftemp);
593c68996e2SPoul-Henning Kamp 		time_status |= STA_MODE;
594c68996e2SPoul-Henning Kamp 	} else {
595c68996e2SPoul-Henning Kamp 		L_LINT(ftemp, ltemp);
596c68996e2SPoul-Henning Kamp 		L_RSHIFT(ftemp, (SHIFT_PLL + 2 + time_constant) << 1);
597c68996e2SPoul-Henning Kamp 		L_MPY(ftemp, mtemp);
598c68996e2SPoul-Henning Kamp 		L_ADD(time_freq, ftemp);
599c68996e2SPoul-Henning Kamp 		time_status &= ~STA_MODE;
600c68996e2SPoul-Henning Kamp 	}
601227ee8a1SPoul-Henning Kamp 	time_reftime = time_second;
602c68996e2SPoul-Henning Kamp 	if (L_GINT(time_freq) > MAXFREQ)
603c68996e2SPoul-Henning Kamp 		L_LINT(time_freq, MAXFREQ);
604c68996e2SPoul-Henning Kamp 	else if (L_GINT(time_freq) < -MAXFREQ)
605c68996e2SPoul-Henning Kamp 		L_LINT(time_freq, -MAXFREQ);
6063f31c649SGarrett Wollman }
6073f31c649SGarrett Wollman 
6086f70df15SPoul-Henning Kamp #ifdef PPS_SYNC
6096f70df15SPoul-Henning Kamp /*
6106f70df15SPoul-Henning Kamp  * hardpps() - discipline CPU clock oscillator to external PPS signal
6116f70df15SPoul-Henning Kamp  *
6126f70df15SPoul-Henning Kamp  * This routine is called at each PPS interrupt in order to discipline
6136f70df15SPoul-Henning Kamp  * the CPU clock oscillator to the PPS signal. It measures the PPS phase
6146f70df15SPoul-Henning Kamp  * and leaves it in a handy spot for the hardclock() routine. It
6156f70df15SPoul-Henning Kamp  * integrates successive PPS phase differences and calculates the
6166f70df15SPoul-Henning Kamp  * frequency offset. This is used in hardclock() to discipline the CPU
617c68996e2SPoul-Henning Kamp  * clock oscillator so that the intrinsic frequency error is cancelled
618c68996e2SPoul-Henning Kamp  * out. The code requires the caller to capture the time and
619c68996e2SPoul-Henning Kamp  * architecture-dependent hardware counter values in nanoseconds at the
620c68996e2SPoul-Henning Kamp  * on-time PPS signal transition.
6216f70df15SPoul-Henning Kamp  *
622c68996e2SPoul-Henning Kamp  * Note that, on some Unix systems this routine runs at an interrupt
6236f70df15SPoul-Henning Kamp  * priority level higher than the timer interrupt routine hardclock().
6246f70df15SPoul-Henning Kamp  * Therefore, the variables used are distinct from the hardclock()
625c68996e2SPoul-Henning Kamp  * variables, except for the actual time and frequency variables, which
626c68996e2SPoul-Henning Kamp  * are determined by this routine and updated atomically.
6276f70df15SPoul-Henning Kamp  */
6286f70df15SPoul-Henning Kamp void
629c68996e2SPoul-Henning Kamp hardpps(tsp, nsec)
630c68996e2SPoul-Henning Kamp 	struct timespec *tsp;	/* time at PPS */
631c68996e2SPoul-Henning Kamp 	long nsec;		/* hardware counter at PPS */
6326f70df15SPoul-Henning Kamp {
633c68996e2SPoul-Henning Kamp 	long u_sec, u_nsec, v_nsec; /* temps */
634c68996e2SPoul-Henning Kamp 	l_fp ftemp;
6356f70df15SPoul-Henning Kamp 
6366f70df15SPoul-Henning Kamp 	/*
637c68996e2SPoul-Henning Kamp 	 * The signal is first processed by a frequency discriminator
638c68996e2SPoul-Henning Kamp 	 * which rejects noise and input signals with frequencies
639c68996e2SPoul-Henning Kamp 	 * outside the range 1 +-MAXFREQ PPS. If two hits occur in the
640c68996e2SPoul-Henning Kamp 	 * same second, we ignore the later hit; if not and a hit occurs
641c68996e2SPoul-Henning Kamp 	 * outside the range gate, keep the later hit but do not
642c68996e2SPoul-Henning Kamp 	 * process it.
6436f70df15SPoul-Henning Kamp 	 */
644c68996e2SPoul-Henning Kamp 	time_status |= STA_PPSSIGNAL | STA_PPSJITTER;
645c68996e2SPoul-Henning Kamp 	time_status &= ~(STA_PPSWANDER | STA_PPSERROR);
646c68996e2SPoul-Henning Kamp 	pps_valid = PPS_VALID;
647c68996e2SPoul-Henning Kamp 	u_sec = tsp->tv_sec;
648c68996e2SPoul-Henning Kamp 	u_nsec = tsp->tv_nsec;
649c68996e2SPoul-Henning Kamp 	if (u_nsec >= (NANOSECOND >> 1)) {
650c68996e2SPoul-Henning Kamp 		u_nsec -= NANOSECOND;
651c68996e2SPoul-Henning Kamp 		u_sec++;
6526f70df15SPoul-Henning Kamp 	}
653c68996e2SPoul-Henning Kamp 	v_nsec = u_nsec - pps_tf[0].nsec;
654c68996e2SPoul-Henning Kamp 	if (u_sec == pps_tf[0].sec && v_nsec < -MAXFREQ) {
655c68996e2SPoul-Henning Kamp 		return;
656c68996e2SPoul-Henning Kamp 	}
657c68996e2SPoul-Henning Kamp 	pps_tf[2] = pps_tf[1];
658c68996e2SPoul-Henning Kamp 	pps_tf[1] = pps_tf[0];
659c68996e2SPoul-Henning Kamp 	pps_tf[0].sec = u_sec;
660c68996e2SPoul-Henning Kamp 	pps_tf[0].nsec = u_nsec;
6616f70df15SPoul-Henning Kamp 
6626f70df15SPoul-Henning Kamp 	/*
663c68996e2SPoul-Henning Kamp 	 * Compute the difference between the current and previous
664c68996e2SPoul-Henning Kamp 	 * counter values. If the difference exceeds 0.5 s, assume it
665c68996e2SPoul-Henning Kamp 	 * has wrapped around, so correct 1.0 s. If the result exceeds
666c68996e2SPoul-Henning Kamp 	 * the tick interval, the sample point has crossed a tick
667c68996e2SPoul-Henning Kamp 	 * boundary during the last second, so correct the tick. Very
668c68996e2SPoul-Henning Kamp 	 * intricate.
669c68996e2SPoul-Henning Kamp 	 */
67032c20357SPoul-Henning Kamp 	u_nsec = nsec;
671c68996e2SPoul-Henning Kamp 	if (u_nsec > (NANOSECOND >> 1))
672c68996e2SPoul-Henning Kamp 		u_nsec -= NANOSECOND;
673c68996e2SPoul-Henning Kamp 	else if (u_nsec < -(NANOSECOND >> 1))
674c68996e2SPoul-Henning Kamp 		u_nsec += NANOSECOND;
675884ab557SPoul-Henning Kamp 	pps_fcount += u_nsec;
676c68996e2SPoul-Henning Kamp 	if (v_nsec > MAXFREQ) {
677c68996e2SPoul-Henning Kamp 		return;
678c68996e2SPoul-Henning Kamp 	}
679c68996e2SPoul-Henning Kamp 	time_status &= ~STA_PPSJITTER;
680c68996e2SPoul-Henning Kamp 
681c68996e2SPoul-Henning Kamp 	/*
682c68996e2SPoul-Henning Kamp 	 * A three-stage median filter is used to help denoise the PPS
6836f70df15SPoul-Henning Kamp 	 * time. The median sample becomes the time offset estimate; the
6846f70df15SPoul-Henning Kamp 	 * difference between the other two samples becomes the time
6856f70df15SPoul-Henning Kamp 	 * dispersion (jitter) estimate.
6866f70df15SPoul-Henning Kamp 	 */
687c68996e2SPoul-Henning Kamp 	if (pps_tf[0].nsec > pps_tf[1].nsec) {
688c68996e2SPoul-Henning Kamp 		if (pps_tf[1].nsec > pps_tf[2].nsec) {
689c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[1];	/* 0 1 2 */
690c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[0].nsec - pps_tf[2].nsec;
691c68996e2SPoul-Henning Kamp 		} else if (pps_tf[2].nsec > pps_tf[0].nsec) {
692c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[0];	/* 2 0 1 */
693c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[2].nsec - pps_tf[1].nsec;
6946f70df15SPoul-Henning Kamp 		} else {
695c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[2];	/* 0 2 1 */
696c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[0].nsec - pps_tf[1].nsec;
697c68996e2SPoul-Henning Kamp 		}
698c68996e2SPoul-Henning Kamp 	} else {
699c68996e2SPoul-Henning Kamp 		if (pps_tf[1].nsec < pps_tf[2].nsec) {
700c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[1];	/* 2 1 0 */
701c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[2].nsec - pps_tf[0].nsec;
702c68996e2SPoul-Henning Kamp 		} else  if (pps_tf[2].nsec < pps_tf[0].nsec) {
703c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[0];	/* 1 0 2 */
704c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[1].nsec - pps_tf[2].nsec;
705c68996e2SPoul-Henning Kamp 		} else {
706c68996e2SPoul-Henning Kamp 			pps_filt = pps_tf[2];	/* 1 2 0 */
707c68996e2SPoul-Henning Kamp 			u_nsec = pps_tf[1].nsec - pps_tf[0].nsec;
7086f70df15SPoul-Henning Kamp 		}
7096f70df15SPoul-Henning Kamp 	}
7106f70df15SPoul-Henning Kamp 
7116f70df15SPoul-Henning Kamp 	/*
712c68996e2SPoul-Henning Kamp 	 * Nominal jitter is due to PPS signal noise and  interrupt
713c68996e2SPoul-Henning Kamp 	 * latency. If it exceeds the jitter limit, the sample is
714c68996e2SPoul-Henning Kamp 	 * discarded. otherwise, if so enabled, the time offset is
715c68996e2SPoul-Henning Kamp 	 * updated. The offsets are accumulated over the phase averaging
716c68996e2SPoul-Henning Kamp 	 * interval to improve accuracy. The jitter is averaged only for
717c68996e2SPoul-Henning Kamp 	 * performance monitoring. We can tolerate a modest loss of data
718c68996e2SPoul-Henning Kamp 	 * here without degrading time accuracy.
7196f70df15SPoul-Henning Kamp 	 */
720c68996e2SPoul-Henning Kamp 	if (u_nsec > MAXTIME) {
721c68996e2SPoul-Henning Kamp 		time_status |= STA_PPSJITTER;
722c68996e2SPoul-Henning Kamp 		pps_jitcnt++;
723c68996e2SPoul-Henning Kamp 	} else if (time_status & STA_PPSTIME) {
724c68996e2SPoul-Henning Kamp 		pps_offacc -= pps_filt.nsec;
725c68996e2SPoul-Henning Kamp 		pps_offcnt++;
726c68996e2SPoul-Henning Kamp 	}
727c68996e2SPoul-Henning Kamp 	if (pps_offcnt >= (1 << PPS_PAVG)) {
728c68996e2SPoul-Henning Kamp 		if (time_status & STA_PPSTIME) {
729c68996e2SPoul-Henning Kamp 			L_LINT(time_offset, pps_offacc);
730c68996e2SPoul-Henning Kamp 			L_RSHIFT(time_offset, PPS_PAVG);
731c68996e2SPoul-Henning Kamp 		}
732c68996e2SPoul-Henning Kamp 		pps_offacc = 0;
733c68996e2SPoul-Henning Kamp 		pps_offcnt = 0;
734c68996e2SPoul-Henning Kamp 	}
735c68996e2SPoul-Henning Kamp 	pps_jitter += (u_nsec - pps_jitter) >> PPS_FAVG;
736c68996e2SPoul-Henning Kamp 	u_sec = pps_tf[0].sec - pps_lastsec;
737f425c1f6SPoul-Henning Kamp 	if (ntp_div && ntp_mult) {
738f425c1f6SPoul-Henning Kamp 		L_LINT(ftemp, (pps_filt.nsec));
739f425c1f6SPoul-Henning Kamp 		L_RSHIFT(ftemp, ntp_div);
740f425c1f6SPoul-Henning Kamp 		L_MPY(ftemp, ntp_mult);
741f425c1f6SPoul-Henning Kamp 		L_ADD(pps_freq, ftemp);
742f425c1f6SPoul-Henning Kamp 		if (time_status & STA_PPSFREQ)
743f425c1f6SPoul-Henning Kamp 			time_freq = pps_freq;
744f425c1f6SPoul-Henning Kamp 		return;
745f425c1f6SPoul-Henning Kamp 	}
746c68996e2SPoul-Henning Kamp 	if (u_sec < (1 << pps_shift))
747c68996e2SPoul-Henning Kamp 		return;
748c68996e2SPoul-Henning Kamp 
749c68996e2SPoul-Henning Kamp 	/*
750c68996e2SPoul-Henning Kamp 	 * At the end of the calibration interval the difference between
751c68996e2SPoul-Henning Kamp 	 * the first and last counter values becomes the scaled
752c68996e2SPoul-Henning Kamp 	 * frequency. It will later be divided by the length of the
753c68996e2SPoul-Henning Kamp 	 * interval to determine the frequency update. If the frequency
754c68996e2SPoul-Henning Kamp 	 * exceeds a sanity threshold, or if the actual calibration
755c68996e2SPoul-Henning Kamp 	 * interval is not equal to the expected length, the data are
756c68996e2SPoul-Henning Kamp 	 * discarded. We can tolerate a modest loss of data here without
757c68996e2SPoul-Henning Kamp 	 * degrading frequency ccuracy.
758c68996e2SPoul-Henning Kamp 	 */
759c68996e2SPoul-Henning Kamp 	pps_calcnt++;
760884ab557SPoul-Henning Kamp 	v_nsec = -pps_fcount;
761c68996e2SPoul-Henning Kamp 	pps_lastsec = pps_tf[0].sec;
762884ab557SPoul-Henning Kamp 	pps_fcount = 0;
763c68996e2SPoul-Henning Kamp 	u_nsec = MAXFREQ << pps_shift;
764c68996e2SPoul-Henning Kamp 	if (v_nsec > u_nsec || v_nsec < -u_nsec || u_sec != (1 <<
765c68996e2SPoul-Henning Kamp 	    pps_shift)) {
766c68996e2SPoul-Henning Kamp 		time_status |= STA_PPSERROR;
767c68996e2SPoul-Henning Kamp 		pps_errcnt++;
768c68996e2SPoul-Henning Kamp 		return;
769c68996e2SPoul-Henning Kamp 	}
770c68996e2SPoul-Henning Kamp 
771c68996e2SPoul-Henning Kamp 	/*
772c68996e2SPoul-Henning Kamp 	 * If the actual calibration interval is not equal to the
773c68996e2SPoul-Henning Kamp 	 * expected length, the data are discarded. If the wander is
774c68996e2SPoul-Henning Kamp 	 * less than the wander threshold for four consecutive
775c68996e2SPoul-Henning Kamp 	 * intervals, the interval is doubled; if it is greater than the
776c68996e2SPoul-Henning Kamp 	 * threshold for four consecutive intervals, the interval is
777c68996e2SPoul-Henning Kamp 	 * halved. The scaled frequency offset is converted to frequency
778c68996e2SPoul-Henning Kamp 	 * offset. The stability metric is calculated as the average of
779c68996e2SPoul-Henning Kamp 	 * recent frequency changes, but is used only for performance
780c68996e2SPoul-Henning Kamp 	 * monitoring.
781c68996e2SPoul-Henning Kamp 	 */
782c68996e2SPoul-Henning Kamp 	L_LINT(ftemp, v_nsec);
783c68996e2SPoul-Henning Kamp 	L_RSHIFT(ftemp, pps_shift);
784c68996e2SPoul-Henning Kamp 	L_SUB(ftemp, pps_freq);
785c68996e2SPoul-Henning Kamp 	u_nsec = L_GINT(ftemp);
786c68996e2SPoul-Henning Kamp 	if (u_nsec > MAXWANDER) {
787c68996e2SPoul-Henning Kamp 		L_LINT(ftemp, MAXWANDER);
788c68996e2SPoul-Henning Kamp 		pps_intcnt--;
789c68996e2SPoul-Henning Kamp 		time_status |= STA_PPSWANDER;
790c68996e2SPoul-Henning Kamp 		pps_stbcnt++;
791c68996e2SPoul-Henning Kamp 	} else if (u_nsec < -MAXWANDER) {
792c68996e2SPoul-Henning Kamp 		L_LINT(ftemp, -MAXWANDER);
793c68996e2SPoul-Henning Kamp 		pps_intcnt--;
794c68996e2SPoul-Henning Kamp 		time_status |= STA_PPSWANDER;
795c68996e2SPoul-Henning Kamp 		pps_stbcnt++;
796c68996e2SPoul-Henning Kamp 	} else {
7976f70df15SPoul-Henning Kamp 		pps_intcnt++;
7986f70df15SPoul-Henning Kamp 	}
799c68996e2SPoul-Henning Kamp 	if (pps_intcnt >= 4) {
800c68996e2SPoul-Henning Kamp 		pps_intcnt = 4;
801c68996e2SPoul-Henning Kamp 		if (pps_shift < PPS_FAVGMAX) {
802c68996e2SPoul-Henning Kamp 			pps_shift++;
803c68996e2SPoul-Henning Kamp 			pps_intcnt = 0;
804c68996e2SPoul-Henning Kamp 		}
805c68996e2SPoul-Henning Kamp 	} else if (pps_intcnt <= -4) {
806c68996e2SPoul-Henning Kamp 		pps_intcnt = -4;
807c68996e2SPoul-Henning Kamp 		if (pps_shift > PPS_FAVG) {
808c68996e2SPoul-Henning Kamp 			pps_shift--;
809c68996e2SPoul-Henning Kamp 			pps_intcnt = 0;
810c68996e2SPoul-Henning Kamp 		}
811c68996e2SPoul-Henning Kamp 	}
812c68996e2SPoul-Henning Kamp 	if (u_nsec < 0)
813c68996e2SPoul-Henning Kamp 		u_nsec = -u_nsec;
814c68996e2SPoul-Henning Kamp 	pps_stabil += (u_nsec * SCALE_PPM - pps_stabil) >> PPS_FAVG;
8159ada5a50SPoul-Henning Kamp 
816c68996e2SPoul-Henning Kamp 	/*
817c68996e2SPoul-Henning Kamp 	 * The frequency offset is averaged into the PPS frequency. If
818c68996e2SPoul-Henning Kamp 	 * enabled, the system clock frequency is updated as well.
819c68996e2SPoul-Henning Kamp 	 */
820f425c1f6SPoul-Henning Kamp 	L_RSHIFT(ftemp, PPS_FAVG);
821c68996e2SPoul-Henning Kamp 	L_ADD(pps_freq, ftemp);
822c68996e2SPoul-Henning Kamp 	u_nsec = L_GINT(pps_freq);
823c68996e2SPoul-Henning Kamp 	if (u_nsec > MAXFREQ)
824c68996e2SPoul-Henning Kamp 		L_LINT(pps_freq, MAXFREQ);
825c68996e2SPoul-Henning Kamp 	else if (u_nsec < -MAXFREQ)
826c68996e2SPoul-Henning Kamp 		L_LINT(pps_freq, -MAXFREQ);
827c68996e2SPoul-Henning Kamp 	if (time_status & STA_PPSFREQ)
828c68996e2SPoul-Henning Kamp 		time_freq = pps_freq;
829c68996e2SPoul-Henning Kamp }
8306f70df15SPoul-Henning Kamp #endif /* PPS_SYNC */
831