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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
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Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+/*****************************************************************************
+ * *
+ * Copyright (c) David L. Mills 1993 *
+ * *
+ * Permission to use, copy, modify, and distribute this software and its *
+ * documentation for any purpose and without fee is hereby granted, provided *
+ * that the above copyright notice appears in all copies and that both the *
+ * copyright notice and this permission notice appear in supporting *
+ * documentation, and that the name University of Delaware not be used in *
+ * advertising or publicity pertaining to distribution of the software *
+ * without specific, written prior permission. The University of Delaware *
+ * makes no representations about the suitability this software for any *
+ * purpose. It is provided "as is" without express or implied warranty. *
+ * *
+ *****************************************************************************/
+
+/*
+ * Modification history timex.h
+ *
+ * 29 Dec 97 Russell King
+ * Moved CLOCK_TICK_RATE, CLOCK_TICK_FACTOR and FINETUNE to asm/timex.h
+ * for ARM machines
+ *
+ * 9 Jan 97 Adrian Sun
+ * Shifted LATCH define to allow access to alpha machines.
+ *
+ * 26 Sep 94 David L. Mills
+ * Added defines for hybrid phase/frequency-lock loop.
+ *
+ * 19 Mar 94 David L. Mills
+ * Moved defines from kernel routines to header file and added new
+ * defines for PPS phase-lock loop.
+ *
+ * 20 Feb 94 David L. Mills
+ * Revised status codes and structures for external clock and PPS
+ * signal discipline.
+ *
+ * 28 Nov 93 David L. Mills
+ * Adjusted parameters to improve stability and increase poll
+ * interval.
+ *
+ * 17 Sep 93 David L. Mills
+ * Created file $NTP/include/sys/timex.h
+ * 07 Oct 93 Torsten Duwe
+ * Derived linux/timex.h
+ * 1995-08-13 Torsten Duwe
+ * kernel PLL updated to 1994-12-13 specs (rfc-1589)
+ * 1997-08-30 Ulrich Windl
+ * Added new constant NTP_PHASE_LIMIT
+ * 2004-08-12 Christoph Lameter
+ * Reworked time interpolation logic
+ */
+#ifndef _LINUX_TIMEX_H
+#define _LINUX_TIMEX_H
+
+#include <linux/config.h>
+#include <linux/compiler.h>
+#include <linux/time.h>
+
+#include <asm/param.h>
+#include <asm/timex.h>
+
+/*
+ * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
+ * for a slightly underdamped convergence characteristic. SHIFT_KH
+ * establishes the damping of the FLL and is chosen by wisdom and black
+ * art.
+ *
+ * MAXTC establishes the maximum time constant of the PLL. With the
+ * SHIFT_KG and SHIFT_KF values given and a time constant range from
+ * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
+ * respectively.
+ */
+#define SHIFT_KG 6 /* phase factor (shift) */
+#define SHIFT_KF 16 /* PLL frequency factor (shift) */
+#define SHIFT_KH 2 /* FLL frequency factor (shift) */
+#define MAXTC 6 /* maximum time constant (shift) */
+
+/*
+ * The SHIFT_SCALE define establishes the decimal point of the time_phase
+ * variable which serves as an extension to the low-order bits of the
+ * system clock variable. The SHIFT_UPDATE define establishes the decimal
+ * point of the time_offset variable which represents the current offset
+ * with respect to standard time. The FINENSEC define represents 1 nsec in
+ * scaled units.
+ *
+ * SHIFT_USEC defines the scaling (shift) of the time_freq and
+ * time_tolerance variables, which represent the current frequency
+ * offset and maximum frequency tolerance.
+ *
+ * FINENSEC is 1 ns in SHIFT_UPDATE units of the time_phase variable.
+ */
+#define SHIFT_SCALE 22 /* phase scale (shift) */
+#define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */
+#define SHIFT_USEC 16 /* frequency offset scale (shift) */
+#define FINENSEC (1L << (SHIFT_SCALE - 10)) /* ~1 ns in phase units */
+
+#define MAXPHASE 512000L /* max phase error (us) */
+#define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
+#define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */
+#define MINSEC 16L /* min interval between updates (s) */
+#define MAXSEC 1200L /* max interval between updates (s) */
+#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */
+
+/*
+ * The following defines are used only if a pulse-per-second (PPS)
+ * signal is available and connected via a modem control lead, such as
+ * produced by the optional ppsclock feature incorporated in the Sun
+ * asynch driver. They establish the design parameters of the frequency-
+ * lock loop used to discipline the CPU clock oscillator to the PPS
+ * signal.
+ *
+ * PPS_AVG is the averaging factor for the frequency loop, as well as
+ * the time and frequency dispersion.
+ *
+ * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum
+ * calibration intervals, respectively, in seconds as a power of two.
+ *
+ * PPS_VALID is the maximum interval before the PPS signal is considered
+ * invalid and protocol updates used directly instead.
+ *
+ * MAXGLITCH is the maximum interval before a time offset of more than
+ * MAXTIME is believed.
+ */
+#define PPS_AVG 2 /* pps averaging constant (shift) */
+#define PPS_SHIFT 2 /* min interval duration (s) (shift) */
+#define PPS_SHIFTMAX 8 /* max interval duration (s) (shift) */
+#define PPS_VALID 120 /* pps signal watchdog max (s) */
+#define MAXGLITCH 30 /* pps signal glitch max (s) */
+
+/*
+ * syscall interface - used (mainly by NTP daemon)
+ * to discipline kernel clock oscillator
+ */
+struct timex {
+ unsigned int modes; /* mode selector */
+ long offset; /* time offset (usec) */
+ long freq; /* frequency offset (scaled ppm) */
+ long maxerror; /* maximum error (usec) */
+ long esterror; /* estimated error (usec) */
+ int status; /* clock command/status */
+ long constant; /* pll time constant */
+ long precision; /* clock precision (usec) (read only) */
+ long tolerance; /* clock frequency tolerance (ppm)
+ * (read only)
+ */
+ struct timeval time; /* (read only) */
+ long tick; /* (modified) usecs between clock ticks */
+
+ long ppsfreq; /* pps frequency (scaled ppm) (ro) */
+ long jitter; /* pps jitter (us) (ro) */
+ int shift; /* interval duration (s) (shift) (ro) */
+ long stabil; /* pps stability (scaled ppm) (ro) */
+ long jitcnt; /* jitter limit exceeded (ro) */
+ long calcnt; /* calibration intervals (ro) */
+ long errcnt; /* calibration errors (ro) */
+ long stbcnt; /* stability limit exceeded (ro) */
+
+ int :32; int :32; int :32; int :32;
+ int :32; int :32; int :32; int :32;
+ int :32; int :32; int :32; int :32;
+};
+
+/*
+ * Mode codes (timex.mode)
+ */
+#define ADJ_OFFSET 0x0001 /* time offset */
+#define ADJ_FREQUENCY 0x0002 /* frequency offset */
+#define ADJ_MAXERROR 0x0004 /* maximum time error */
+#define ADJ_ESTERROR 0x0008 /* estimated time error */
+#define ADJ_STATUS 0x0010 /* clock status */
+#define ADJ_TIMECONST 0x0020 /* pll time constant */
+#define ADJ_TICK 0x4000 /* tick value */
+#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
+
+/* xntp 3.4 compatibility names */
+#define MOD_OFFSET ADJ_OFFSET
+#define MOD_FREQUENCY ADJ_FREQUENCY
+#define MOD_MAXERROR ADJ_MAXERROR
+#define MOD_ESTERROR ADJ_ESTERROR
+#define MOD_STATUS ADJ_STATUS
+#define MOD_TIMECONST ADJ_TIMECONST
+#define MOD_CLKB ADJ_TICK
+#define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */
+
+
+/*
+ * Status codes (timex.status)
+ */
+#define STA_PLL 0x0001 /* enable PLL updates (rw) */
+#define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
+#define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
+#define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
+
+#define STA_INS 0x0010 /* insert leap (rw) */
+#define STA_DEL 0x0020 /* delete leap (rw) */
+#define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
+#define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
+
+#define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
+#define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
+#define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
+#define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
+
+#define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
+
+#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
+ STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
+
+/*
+ * Clock states (time_state)
+ */
+#define TIME_OK 0 /* clock synchronized, no leap second */
+#define TIME_INS 1 /* insert leap second */
+#define TIME_DEL 2 /* delete leap second */
+#define TIME_OOP 3 /* leap second in progress */
+#define TIME_WAIT 4 /* leap second has occurred */
+#define TIME_ERROR 5 /* clock not synchronized */
+#define TIME_BAD TIME_ERROR /* bw compat */
+
+#ifdef __KERNEL__
+/*
+ * kernel variables
+ * Note: maximum error = NTP synch distance = dispersion + delay / 2;
+ * estimated error = NTP dispersion.
+ */
+extern unsigned long tick_usec; /* USER_HZ period (usec) */
+extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
+extern int tickadj; /* amount of adjustment per tick */
+
+/*
+ * phase-lock loop variables
+ */
+extern int time_state; /* clock status */
+extern int time_status; /* clock synchronization status bits */
+extern long time_offset; /* time adjustment (us) */
+extern long time_constant; /* pll time constant */
+extern long time_tolerance; /* frequency tolerance (ppm) */
+extern long time_precision; /* clock precision (us) */
+extern long time_maxerror; /* maximum error */
+extern long time_esterror; /* estimated error */
+
+extern long time_freq; /* frequency offset (scaled ppm) */
+extern long time_reftime; /* time at last adjustment (s) */
+
+extern long time_adjust; /* The amount of adjtime left */
+extern long time_next_adjust; /* Value for time_adjust at next tick */
+
+/* interface variables pps->timer interrupt */
+extern long pps_offset; /* pps time offset (us) */
+extern long pps_jitter; /* time dispersion (jitter) (us) */
+extern long pps_freq; /* frequency offset (scaled ppm) */
+extern long pps_stabil; /* frequency dispersion (scaled ppm) */
+extern long pps_valid; /* pps signal watchdog counter */
+
+/* interface variables pps->adjtimex */
+extern int pps_shift; /* interval duration (s) (shift) */
+extern long pps_jitcnt; /* jitter limit exceeded */
+extern long pps_calcnt; /* calibration intervals */
+extern long pps_errcnt; /* calibration errors */
+extern long pps_stbcnt; /* stability limit exceeded */
+
+#ifdef CONFIG_TIME_INTERPOLATION
+
+#define TIME_SOURCE_CPU 0
+#define TIME_SOURCE_MMIO64 1
+#define TIME_SOURCE_MMIO32 2
+#define TIME_SOURCE_FUNCTION 3
+
+/* For proper operations time_interpolator clocks must run slightly slower
+ * than the standard clock since the interpolator may only correct by having
+ * time jump forward during a tick. A slower clock is usually a side effect
+ * of the integer divide of the nanoseconds in a second by the frequency.
+ * The accuracy of the division can be increased by specifying a shift.
+ * However, this may cause the clock not to be slow enough.
+ * The interpolator will self-tune the clock by slowing down if no
+ * resets occur or speeding up if the time jumps per analysis cycle
+ * become too high.
+ *
+ * Setting jitter compensates for a fluctuating timesource by comparing
+ * to the last value read from the timesource to insure that an earlier value
+ * is not returned by a later call. The price to pay
+ * for the compensation is that the timer routines are not as scalable anymore.
+ */
+
+struct time_interpolator {
+ u16 source; /* time source flags */
+ u8 shift; /* increases accuracy of multiply by shifting. */
+ /* Note that bits may be lost if shift is set too high */
+ u8 jitter; /* if set compensate for fluctuations */
+ u32 nsec_per_cyc; /* set by register_time_interpolator() */
+ void *addr; /* address of counter or function */
+ u64 mask; /* mask the valid bits of the counter */
+ unsigned long offset; /* nsec offset at last update of interpolator */
+ u64 last_counter; /* counter value in units of the counter at last update */
+ u64 last_cycle; /* Last timer value if TIME_SOURCE_JITTER is set */
+ u64 frequency; /* frequency in counts/second */
+ long drift; /* drift in parts-per-million (or -1) */
+ unsigned long skips; /* skips forward */
+ unsigned long ns_skipped; /* nanoseconds skipped */
+ struct time_interpolator *next;
+};
+
+extern void register_time_interpolator(struct time_interpolator *);
+extern void unregister_time_interpolator(struct time_interpolator *);
+extern void time_interpolator_reset(void);
+extern unsigned long time_interpolator_get_offset(void);
+
+#else /* !CONFIG_TIME_INTERPOLATION */
+
+static inline void
+time_interpolator_reset(void)
+{
+}
+
+#endif /* !CONFIG_TIME_INTERPOLATION */
+
+#endif /* KERNEL */
+
+#endif /* LINUX_TIMEX_H */