7dffa3c673
Remove the leap second handling from second_overflow(), which doesn't have to check for it every second anymore. With CONFIG_NO_HZ this also makes sure the leap second is handled close to the full second. Additionally this makes it possible to abort a leap second properly by resetting the STA_INS/STA_DEL status bits. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
257 lines
9 KiB
C
257 lines
9 KiB
C
/*****************************************************************************
|
|
* *
|
|
* 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/compiler.h>
|
|
#include <linux/time.h>
|
|
|
|
#include <asm/param.h>
|
|
|
|
#define NTP_API 4 /* NTP API version */
|
|
|
|
/*
|
|
* 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_PLL 4 /* PLL frequency factor (shift) */
|
|
#define SHIFT_FLL 2 /* FLL frequency factor (shift) */
|
|
#define MAXTC 10 /* maximum time constant (shift) */
|
|
|
|
/*
|
|
* SHIFT_USEC defines the scaling (shift) of the time_freq and
|
|
* time_tolerance variables, which represent the current frequency
|
|
* offset and maximum frequency tolerance.
|
|
*/
|
|
#define SHIFT_USEC 16 /* frequency offset scale (shift) */
|
|
#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
|
|
#define PPM_SCALE_INV_SHIFT 20
|
|
#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
|
|
PPM_SCALE + 1)
|
|
|
|
#define MAXPHASE 500000000l /* max phase error (ns) */
|
|
#define MAXFREQ 500000 /* max frequency error (ns/s) */
|
|
#define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT)
|
|
#define MINSEC 256 /* min interval between updates (s) */
|
|
#define MAXSEC 2048 /* max interval between updates (s) */
|
|
#define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */
|
|
|
|
/*
|
|
* 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 tai; /* TAI offset (ro) */
|
|
|
|
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_TAI 0x0080 /* set TAI offset */
|
|
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
|
|
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
|
|
#define ADJ_TICK 0x4000 /* tick value */
|
|
#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
|
|
#define ADJ_OFFSET_SS_READ 0xa001 /* read-only 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
|
|
|
|
|
|
/*
|
|
* 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_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */
|
|
#define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
|
|
#define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */
|
|
|
|
/* read-only bits */
|
|
#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
|
|
STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
|
|
|
|
/*
|
|
* 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__
|
|
#include <asm/timex.h>
|
|
|
|
/*
|
|
* 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_status; /* clock synchronization status bits */
|
|
extern long time_maxerror; /* maximum error */
|
|
extern long time_esterror; /* estimated error */
|
|
|
|
extern long time_adjust; /* The amount of adjtime left */
|
|
|
|
extern void ntp_init(void);
|
|
extern void ntp_clear(void);
|
|
|
|
/**
|
|
* ntp_synced - Returns 1 if the NTP status is not UNSYNC
|
|
*
|
|
*/
|
|
static inline int ntp_synced(void)
|
|
{
|
|
return !(time_status & STA_UNSYNC);
|
|
}
|
|
|
|
/* Required to safely shift negative values */
|
|
#define shift_right(x, s) ({ \
|
|
__typeof__(x) __x = (x); \
|
|
__typeof__(s) __s = (s); \
|
|
__x < 0 ? -(-__x >> __s) : __x >> __s; \
|
|
})
|
|
|
|
#define NTP_SCALE_SHIFT 32
|
|
|
|
#ifdef CONFIG_NO_HZ
|
|
#define NTP_INTERVAL_FREQ (2)
|
|
#else
|
|
#define NTP_INTERVAL_FREQ (HZ)
|
|
#endif
|
|
#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
|
|
|
|
/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
|
|
extern u64 tick_length;
|
|
|
|
extern void second_overflow(void);
|
|
extern void update_ntp_one_tick(void);
|
|
extern int do_adjtimex(struct timex *);
|
|
|
|
/* Don't use! Compatibility define for existing users. */
|
|
#define tickadj (500/HZ ? : 1)
|
|
|
|
int read_current_timer(unsigned long *timer_val);
|
|
|
|
#endif /* KERNEL */
|
|
|
|
#endif /* LINUX_TIMEX_H */
|