Messages in this thread Patch in this message | | | Subject | [RFC][PATCH - 1/12] NTP cleanup: Move NTP code into ntp.c | From | john stultz <> | Date | Fri, 15 Jul 2005 19:57:00 -0700 |
| |
All, This patch moves the generic NTP code from time.c and timer.c into ntp.c. It makes most of the NTP variables static providing more understandable interfaces like ntp_synced() and ntp_clear().
Since some of the newly made static variables are used in arch generic code, this patch alone will not compile. Thus this patch requires part 2 of the series which fixes the arch specific uses of the newly static variables.
Any comments or feedback would be greatly appreciated.
thanks -john
linux-2.6.13-rc3_timeofday-ntp-part1_B4.patch ============================================ diff --git a/include/linux/ntp.h b/include/linux/ntp.h new file mode 100644 --- /dev/null +++ b/include/linux/ntp.h @@ -0,0 +1,28 @@ +/* linux/include/linux/ntp.h + * + * This file NTP state machine accessor functions. + */ + +#ifndef _LINUX_NTP_H +#define _LINUX_NTP_H +#include <linux/types.h> +#include <linux/time.h> +#include <linux/timex.h> + +/* NTP state machine interfaces */ +int ntp_advance(void); +int ntp_adjtimex(struct timex*); +void second_overflow(void); +void ntp_clear(void); +int ntp_synced(void); + +/* Due to ppc64 having its own NTP code, + * these variables cannot be made static just yet + */ +extern int tickadj; +extern long time_offset; +extern long time_freq; +extern long time_adjust; +extern long time_constant; + +#endif diff --git a/include/linux/timex.h b/include/linux/timex.h --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -226,39 +226,6 @@ struct timex { */ 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 diff --git a/kernel/Makefile b/kernel/Makefile --- a/kernel/Makefile +++ b/kernel/Makefile @@ -7,7 +7,7 @@ obj-y = sched.o fork.o exec_domain.o sysctl.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o \ rcupdate.o intermodule.o extable.o params.o posix-timers.o \ - kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o + kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o ntp.o obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o diff --git a/kernel/ntp.c b/kernel/ntp.c new file mode 100644 --- /dev/null +++ b/kernel/ntp.c @@ -0,0 +1,490 @@ +/******************************************************************** +* linux/kernel/ntp.c +* +* NTP state machine and time scaling code. +* +* Code moved from kernel/time.c and kernel/timer.c +* Please see those files for original copyrights. +* +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation; either version 2 of the License, or +* (at your option) any later version. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program; if not, write to the Free Software +* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +* +* Notes: +* +* Hopefully you should never have to understand or touch +* any of the code below. but don't let that keep you from trying! +* +* This code is loosely based on David Mills' RFC 1589 and its +* updates. Please see the following for more details: +* http://www.eecis.udel.edu/~mills/database/rfc/rfc1589.txt +* http://www.eecis.udel.edu/~mills/database/reports/kern/kernb.pdf +* +* NOTE: To simplify the code, we do not implement any of +* the PPS code, as the code that uses it never was merged. +* -johnstul@us.ibm.com +* +*********************************************************************/ + +#include <linux/ntp.h> +#include <linux/jiffies.h> +#include <linux/errno.h> + +#ifdef CONFIG_TIME_INTERPOLATION +void time_interpolator_update(long delta_nsec); +#else +#define time_interpolator_update(x) +#endif + + +static long pps_offset; /* pps time offset (us) */ +static long pps_jitter = MAXTIME; /* time dispersion (jitter) (us) */ + +static long pps_freq; /* frequency offset (scaled ppm) */ +static long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ + +static long pps_valid = PPS_VALID; /* pps signal watchdog counter */ + +static int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ + +static long pps_jitcnt; /* jitter limit exceeded */ +static long pps_calcnt; /* calibration intervals */ +static long pps_errcnt; /* calibration errors */ +static long pps_stbcnt; /* stability limit exceeded */ + +/* Don't completely fail for HZ > 500. */ +int tickadj = 500/HZ ? : 1; /* microsecs */ + + +/* + * phase-lock loop variables + */ +/* TIME_ERROR prevents overwriting the CMOS clock */ +static int time_state = TIME_OK; /* clock synchronization status */ +static int time_status = STA_UNSYNC; /* clock status bits */ +long time_offset; /* time adjustment (us) */ +long time_constant = 2; /* pll time constant */ +static long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */ +static long time_precision = 1; /* clock precision (us) */ +static long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */ +static long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */ +static long time_phase; /* phase offset (scaled us) */ +long time_freq = (((NSEC_PER_SEC + HZ/2) % HZ - HZ/2) << SHIFT_USEC) / NSEC_PER_USEC; + /* frequency offset (scaled ppm) */ +static long time_adj; /* tick adjust (scaled 1 / HZ) */ +static long time_reftime; /* time at last adjustment (s) */ +long time_adjust; +static long time_next_adjust; + +int ntp_advance(void) +{ + long time_adjust_step, delta_nsec; + + if ( (time_adjust_step = time_adjust) != 0 ) { + /* We are doing an adjtime thing. + * + * Prepare time_adjust_step to be within bounds. + * Note that a positive time_adjust means we want the clock + * to run faster. + * + * Limit the amount of the step to be in the range + * -tickadj .. +tickadj + */ + if (time_adjust > tickadj) + time_adjust_step = tickadj; + else if (time_adjust < -tickadj) + time_adjust_step = -tickadj; + + /* Reduce by this step the amount of time left */ + time_adjust -= time_adjust_step; + } + delta_nsec = time_adjust_step * 1000; + + /* + * Advance the phase, once it gets to one microsecond, then + * advance the tick more. + */ + time_phase += time_adj; + if (time_phase <= -FINENSEC) { + long ltemp = -time_phase >> (SHIFT_SCALE - 10); + time_phase += ltemp << (SHIFT_SCALE - 10); + delta_nsec -= ltemp; + } else if (time_phase >= FINENSEC) { + long ltemp = time_phase >> (SHIFT_SCALE - 10); + time_phase -= ltemp << (SHIFT_SCALE - 10); + delta_nsec += ltemp; + } + + /* Changes by adjtime() do not take effect till next tick. */ + if (time_next_adjust != 0) { + time_adjust = time_next_adjust; + time_next_adjust = 0; + } + + return delta_nsec; +} + + +/* + * this routine handles the overflow of the microsecond field + * + * The tricky bits of code to handle the accurate clock support + * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. + * They were originally developed for SUN and DEC kernels. + * All the kudos should go to Dave for this stuff. + * + */ +void second_overflow(void) +{ + long ltemp; + + /* Bump the maxerror field */ + time_maxerror += time_tolerance >> SHIFT_USEC; + if ( time_maxerror > NTP_PHASE_LIMIT ) { + time_maxerror = NTP_PHASE_LIMIT; + time_status |= STA_UNSYNC; + } + + /* + * Leap second processing. If in leap-insert state at + * the end of the day, the system clock is set back one + * second; if in leap-delete state, the system clock is + * set ahead one second. The microtime() routine or + * external clock driver will insure that reported time + * is always monotonic. The ugly divides should be + * replaced. + */ + switch (time_state) { + + case TIME_OK: + if (time_status & STA_INS) + time_state = TIME_INS; + else if (time_status & STA_DEL) + time_state = TIME_DEL; + break; + + case TIME_INS: + if (xtime.tv_sec % 86400 == 0) { + xtime.tv_sec--; + wall_to_monotonic.tv_sec++; + /* The timer interpolator will make time change gradually instead + * of an immediate jump by one second. + */ + time_interpolator_update(-NSEC_PER_SEC); + time_state = TIME_OOP; + clock_was_set(); + printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); + } + break; + + case TIME_DEL: + if ((xtime.tv_sec + 1) % 86400 == 0) { + xtime.tv_sec++; + wall_to_monotonic.tv_sec--; + /* Use of time interpolator for a gradual change of time */ + time_interpolator_update(NSEC_PER_SEC); + time_state = TIME_WAIT; + clock_was_set(); + printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); + } + break; + + case TIME_OOP: + time_state = TIME_WAIT; + break; + + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; + } + + /* + * Compute the phase adjustment for the next second. In + * PLL mode, the offset is reduced by a fixed factor + * times the time constant. In FLL mode the offset is + * used directly. In either mode, the maximum phase + * adjustment for each second is clamped so as to spread + * the adjustment over not more than the number of + * seconds between updates. + */ + if (time_offset < 0) { + ltemp = -time_offset; + if (!(time_status & STA_FLL)) + ltemp >>= SHIFT_KG + time_constant; + if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE) + ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE; + time_offset += ltemp; + time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } else { + ltemp = time_offset; + if (!(time_status & STA_FLL)) + ltemp >>= SHIFT_KG + time_constant; + if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE) + ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE; + time_offset -= ltemp; + time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } + + /* + * Compute the frequency estimate and additional phase + * adjustment due to frequency error for the next + * second. When the PPS signal is engaged, gnaw on the + * watchdog counter and update the frequency computed by + * the pll and the PPS signal. + */ + pps_valid++; + if (pps_valid == PPS_VALID) { /* PPS signal lost */ + pps_jitter = MAXTIME; + pps_stabil = MAXFREQ; + time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | + STA_PPSWANDER | STA_PPSERROR); + } + ltemp = time_freq + pps_freq; + if (ltemp < 0) + time_adj -= -ltemp >> (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + else + time_adj += ltemp >> (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + +#if HZ == 100 + /* Compensate for (HZ==100) != (1 << SHIFT_HZ). + * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14) + */ + if (time_adj < 0) + time_adj -= (-time_adj >> 2) + (-time_adj >> 5); + else + time_adj += (time_adj >> 2) + (time_adj >> 5); +#endif +#if HZ == 1000 + /* Compensate for (HZ==1000) != (1 << SHIFT_HZ). + * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14) + */ + if (time_adj < 0) + time_adj -= (-time_adj >> 6) + (-time_adj >> 7); + else + time_adj += (time_adj >> 6) + (time_adj >> 7); +#endif +} + +/* adjtimex mainly allows reading (and writing, if superuser) of + * kernel time-keeping variables. used by xntpd. + */ +int ntp_adjtimex(struct timex *txc) +{ + long ltemp, mtemp, save_adjust; + int result; + + /* Now we validate the data before disabling interrupts */ + + if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) + /* singleshot must not be used with any other mode bits */ + if (txc->modes != ADJ_OFFSET_SINGLESHOT) + return -EINVAL; + + if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET)) + /* adjustment Offset limited to +- .512 seconds */ + if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE ) + return -EINVAL; + + /* if the quartz is off by more than 10% something is VERY wrong ! */ + if (txc->modes & ADJ_TICK) + if (txc->tick < 900000/USER_HZ || + txc->tick > 1100000/USER_HZ) + return -EINVAL; + + write_seqlock_irq(&xtime_lock); + result = time_state; /* mostly `TIME_OK' */ + + /* Save for later - semantics of adjtime is to return old value */ + save_adjust = time_next_adjust ? time_next_adjust : time_adjust; + +#if 0 /* STA_CLOCKERR is never set yet */ + time_status &= ~STA_CLOCKERR; /* reset STA_CLOCKERR */ +#endif + + /* If there are input parameters, then process them */ + if (txc->modes) { + if (txc->modes & ADJ_STATUS) /* only set allowed bits */ + time_status = (txc->status & ~STA_RONLY) | + (time_status & STA_RONLY); + + if (txc->modes & ADJ_FREQUENCY) { /* p. 22 */ + if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) { + result = -EINVAL; + goto leave; + } + time_freq = txc->freq - pps_freq; + } + + if (txc->modes & ADJ_MAXERROR) { + if (txc->maxerror < 0 + || txc->maxerror >= NTP_PHASE_LIMIT) { + result = -EINVAL; + goto leave; + } + time_maxerror = txc->maxerror; + } + + if (txc->modes & ADJ_ESTERROR) { + if (txc->esterror < 0 + || txc->esterror >= NTP_PHASE_LIMIT) { + result = -EINVAL; + goto leave; + } + time_esterror = txc->esterror; + } + + if (txc->modes & ADJ_TIMECONST) { /* p. 24 */ + if (txc->constant < 0) { /* NTP v4 uses values > 6 */ + result = -EINVAL; + goto leave; + } + time_constant = txc->constant; + } + + if (txc->modes & ADJ_OFFSET) { /* values checked earlier */ + if (txc->modes == ADJ_OFFSET_SINGLESHOT) { + /* adjtime() is independent from ntp_adjtime() */ + if ((time_next_adjust = txc->offset) == 0) + time_adjust = 0; + } else if ( time_status & (STA_PLL | STA_PPSTIME) ) { + ltemp = (time_status + & (STA_PPSTIME | STA_PPSSIGNAL)) + == (STA_PPSTIME | STA_PPSSIGNAL) ? + pps_offset : txc->offset; + + /* + * Scale the phase adjustment and + * clamp to the operating range. + */ + if (ltemp > MAXPHASE) + time_offset = MAXPHASE << SHIFT_UPDATE; + else if (ltemp < -MAXPHASE) + time_offset = -(MAXPHASE + << SHIFT_UPDATE); + else + time_offset = ltemp << SHIFT_UPDATE; + + /* + * Select whether the frequency is to be controlled + * and in which mode (PLL or FLL). Clamp to the operating + * range. Ugly multiply/divide should be replaced someday. + */ + + if (time_status & STA_FREQHOLD || time_reftime == 0) + time_reftime = xtime.tv_sec; + + mtemp = xtime.tv_sec - time_reftime; + time_reftime = xtime.tv_sec; + + if (time_status & STA_FLL) { + if (mtemp >= MINSEC) { + ltemp = (time_offset / mtemp) << (SHIFT_USEC - + SHIFT_UPDATE); + if (ltemp < 0) + time_freq -= -ltemp >> SHIFT_KH; + else + time_freq += ltemp >> SHIFT_KH; + } else /* calibration interval too short (p. 12) */ + result = TIME_ERROR; + } else { /* PLL mode */ + if (mtemp < MAXSEC) { + ltemp *= mtemp; + if (ltemp < 0) + time_freq -= -ltemp >> (time_constant + + time_constant + + SHIFT_KF - SHIFT_USEC); + else + time_freq += ltemp >> (time_constant + + time_constant + + SHIFT_KF - SHIFT_USEC); + } else /* calibration interval too long (p. 12) */ + result = TIME_ERROR; + } + + if (time_freq > time_tolerance) + time_freq = time_tolerance; + else if (time_freq < -time_tolerance) + time_freq = -time_tolerance; + } /* STA_PLL || STA_PPSTIME */ + } /* txc->modes & ADJ_OFFSET */ + + if (txc->modes & ADJ_TICK) { + tick_usec = txc->tick; + tick_nsec = TICK_USEC_TO_NSEC(tick_usec); + } + } /* txc->modes */ +leave: + + if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0 + || ((time_status & (STA_PPSFREQ|STA_PPSTIME)) != 0 + && (time_status & STA_PPSSIGNAL) == 0) + /* p. 24, (b) */ + || ((time_status & (STA_PPSTIME|STA_PPSJITTER)) + == (STA_PPSTIME|STA_PPSJITTER)) + /* p. 24, (c) */ + || ((time_status & STA_PPSFREQ) != 0 + && (time_status & (STA_PPSWANDER|STA_PPSERROR)) != 0)) + /* p. 24, (d) */ + result = TIME_ERROR; + + if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) + txc->offset = save_adjust; + else { + if (time_offset < 0) + txc->offset = -(-time_offset >> SHIFT_UPDATE); + else + txc->offset = time_offset >> SHIFT_UPDATE; + } + txc->freq = time_freq + pps_freq; + txc->maxerror = time_maxerror; + txc->esterror = time_esterror; + txc->status = time_status; + txc->constant = time_constant; + txc->precision = time_precision; + txc->tolerance = time_tolerance; + txc->tick = tick_usec; + txc->ppsfreq = pps_freq; + txc->jitter = pps_jitter >> PPS_AVG; + txc->shift = pps_shift; + txc->stabil = pps_stabil; + txc->jitcnt = pps_jitcnt; + txc->calcnt = pps_calcnt; + txc->errcnt = pps_errcnt; + txc->stbcnt = pps_stbcnt; + write_sequnlock_irq(&xtime_lock); + do_gettimeofday(&txc->time); + return result; +} + +/** + * ntp_clear - Clears the NTP state machine. + * + * Must be called while holding a write on the xtime_lock + */ +void ntp_clear(void) +{ + time_adjust = 0; /* stop active adjtime() */ + time_status |= STA_UNSYNC; + time_maxerror = NTP_PHASE_LIMIT; + time_esterror = NTP_PHASE_LIMIT; +} + +/** + * ntp_synced - Returns 1 if the NTP status is not UNSYNC + * + */ +int ntp_synced(void) +{ + return !(time_status & STA_UNSYNC); +} + diff --git a/kernel/time.c b/kernel/time.c --- a/kernel/time.c +++ b/kernel/time.c @@ -35,6 +35,7 @@ #include <linux/security.h> #include <linux/fs.h> #include <linux/module.h> +#include <linux/ntp.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -198,20 +199,6 @@ asmlinkage long sys_settimeofday(struct return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); } -long pps_offset; /* pps time offset (us) */ -long pps_jitter = MAXTIME; /* time dispersion (jitter) (us) */ - -long pps_freq; /* frequency offset (scaled ppm) */ -long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ - -long pps_valid = PPS_VALID; /* pps signal watchdog counter */ - -int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ - -long pps_jitcnt; /* jitter limit exceeded */ -long pps_calcnt; /* calibration intervals */ -long pps_errcnt; /* calibration errors */ -long pps_stbcnt; /* stability limit exceeded */ /* hook for a loadable hardpps kernel module */ void (*hardpps_ptr)(struct timeval *); @@ -229,184 +216,14 @@ void __attribute__ ((weak)) notify_arch_ */ int do_adjtimex(struct timex *txc) { - long ltemp, mtemp, save_adjust; int result; /* In order to modify anything, you gotta be super-user! */ if (txc->modes && !capable(CAP_SYS_TIME)) return -EPERM; - /* Now we validate the data before disabling interrupts */ - - if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) - /* singleshot must not be used with any other mode bits */ - if (txc->modes != ADJ_OFFSET_SINGLESHOT) - return -EINVAL; - - if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET)) - /* adjustment Offset limited to +- .512 seconds */ - if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE ) - return -EINVAL; - - /* if the quartz is off by more than 10% something is VERY wrong ! */ - if (txc->modes & ADJ_TICK) - if (txc->tick < 900000/USER_HZ || - txc->tick > 1100000/USER_HZ) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - result = time_state; /* mostly `TIME_OK' */ - - /* Save for later - semantics of adjtime is to return old value */ - save_adjust = time_next_adjust ? time_next_adjust : time_adjust; - -#if 0 /* STA_CLOCKERR is never set yet */ - time_status &= ~STA_CLOCKERR; /* reset STA_CLOCKERR */ -#endif - /* If there are input parameters, then process them */ - if (txc->modes) - { - if (txc->modes & ADJ_STATUS) /* only set allowed bits */ - time_status = (txc->status & ~STA_RONLY) | - (time_status & STA_RONLY); - - if (txc->modes & ADJ_FREQUENCY) { /* p. 22 */ - if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) { - result = -EINVAL; - goto leave; - } - time_freq = txc->freq - pps_freq; - } - - if (txc->modes & ADJ_MAXERROR) { - if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) { - result = -EINVAL; - goto leave; - } - time_maxerror = txc->maxerror; - } - - if (txc->modes & ADJ_ESTERROR) { - if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) { - result = -EINVAL; - goto leave; - } - time_esterror = txc->esterror; - } - - if (txc->modes & ADJ_TIMECONST) { /* p. 24 */ - if (txc->constant < 0) { /* NTP v4 uses values > 6 */ - result = -EINVAL; - goto leave; - } - time_constant = txc->constant; - } - - if (txc->modes & ADJ_OFFSET) { /* values checked earlier */ - if (txc->modes == ADJ_OFFSET_SINGLESHOT) { - /* adjtime() is independent from ntp_adjtime() */ - if ((time_next_adjust = txc->offset) == 0) - time_adjust = 0; - } - else if ( time_status & (STA_PLL | STA_PPSTIME) ) { - ltemp = (time_status & (STA_PPSTIME | STA_PPSSIGNAL)) == - (STA_PPSTIME | STA_PPSSIGNAL) ? - pps_offset : txc->offset; - - /* - * Scale the phase adjustment and - * clamp to the operating range. - */ - if (ltemp > MAXPHASE) - time_offset = MAXPHASE << SHIFT_UPDATE; - else if (ltemp < -MAXPHASE) - time_offset = -(MAXPHASE << SHIFT_UPDATE); - else - time_offset = ltemp << SHIFT_UPDATE; - - /* - * Select whether the frequency is to be controlled - * and in which mode (PLL or FLL). Clamp to the operating - * range. Ugly multiply/divide should be replaced someday. - */ - - if (time_status & STA_FREQHOLD || time_reftime == 0) - time_reftime = xtime.tv_sec; - mtemp = xtime.tv_sec - time_reftime; - time_reftime = xtime.tv_sec; - if (time_status & STA_FLL) { - if (mtemp >= MINSEC) { - ltemp = (time_offset / mtemp) << (SHIFT_USEC - - SHIFT_UPDATE); - if (ltemp < 0) - time_freq -= -ltemp >> SHIFT_KH; - else - time_freq += ltemp >> SHIFT_KH; - } else /* calibration interval too short (p. 12) */ - result = TIME_ERROR; - } else { /* PLL mode */ - if (mtemp < MAXSEC) { - ltemp *= mtemp; - if (ltemp < 0) - time_freq -= -ltemp >> (time_constant + - time_constant + - SHIFT_KF - SHIFT_USEC); - else - time_freq += ltemp >> (time_constant + - time_constant + - SHIFT_KF - SHIFT_USEC); - } else /* calibration interval too long (p. 12) */ - result = TIME_ERROR; - } - if (time_freq > time_tolerance) - time_freq = time_tolerance; - else if (time_freq < -time_tolerance) - time_freq = -time_tolerance; - } /* STA_PLL || STA_PPSTIME */ - } /* txc->modes & ADJ_OFFSET */ - if (txc->modes & ADJ_TICK) { - tick_usec = txc->tick; - tick_nsec = TICK_USEC_TO_NSEC(tick_usec); - } - } /* txc->modes */ -leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0 - || ((time_status & (STA_PPSFREQ|STA_PPSTIME)) != 0 - && (time_status & STA_PPSSIGNAL) == 0) - /* p. 24, (b) */ - || ((time_status & (STA_PPSTIME|STA_PPSJITTER)) - == (STA_PPSTIME|STA_PPSJITTER)) - /* p. 24, (c) */ - || ((time_status & STA_PPSFREQ) != 0 - && (time_status & (STA_PPSWANDER|STA_PPSERROR)) != 0)) - /* p. 24, (d) */ - result = TIME_ERROR; + result = ntp_adjtimex(txc); - if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) - txc->offset = save_adjust; - else { - if (time_offset < 0) - txc->offset = -(-time_offset >> SHIFT_UPDATE); - else - txc->offset = time_offset >> SHIFT_UPDATE; - } - txc->freq = time_freq + pps_freq; - txc->maxerror = time_maxerror; - txc->esterror = time_esterror; - txc->status = time_status; - txc->constant = time_constant; - txc->precision = time_precision; - txc->tolerance = time_tolerance; - txc->tick = tick_usec; - txc->ppsfreq = pps_freq; - txc->jitter = pps_jitter >> PPS_AVG; - txc->shift = pps_shift; - txc->stabil = pps_stabil; - txc->jitcnt = pps_jitcnt; - txc->calcnt = pps_calcnt; - txc->errcnt = pps_errcnt; - txc->stbcnt = pps_stbcnt; - write_sequnlock_irq(&xtime_lock); - do_gettimeofday(&txc->time); notify_arch_cmos_timer(); return(result); } @@ -522,10 +339,8 @@ int do_settimeofday (struct timespec *tv set_normalized_timespec(&xtime, sec, nsec); set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - time_adjust = 0; /* stop active adjtime() */ - time_status |= STA_UNSYNC; - time_maxerror = NTP_PHASE_LIMIT; - time_esterror = NTP_PHASE_LIMIT; + ntp_clear(); + time_interpolator_reset(); } write_sequnlock_irq(&xtime_lock); diff --git a/kernel/timer.c b/kernel/timer.c --- a/kernel/timer.c +++ b/kernel/timer.c @@ -33,6 +33,7 @@ #include <linux/posix-timers.h> #include <linux/cpu.h> #include <linux/syscalls.h> +#include <linux/ntp.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -41,7 +42,7 @@ #include <asm/io.h> #ifdef CONFIG_TIME_INTERPOLATION -static void time_interpolator_update(long delta_nsec); +void time_interpolator_update(long delta_nsec); #else #define time_interpolator_update(x) #endif @@ -597,219 +598,17 @@ struct timespec wall_to_monotonic __attr EXPORT_SYMBOL(xtime); -/* Don't completely fail for HZ > 500. */ -int tickadj = 500/HZ ? : 1; /* microsecs */ - - -/* - * phase-lock loop variables - */ -/* TIME_ERROR prevents overwriting the CMOS clock */ -int time_state = TIME_OK; /* clock synchronization status */ -int time_status = STA_UNSYNC; /* clock status bits */ -long time_offset; /* time adjustment (us) */ -long time_constant = 2; /* pll time constant */ -long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */ -long time_precision = 1; /* clock precision (us) */ -long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */ -long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */ -static long time_phase; /* phase offset (scaled us) */ -long time_freq = (((NSEC_PER_SEC + HZ/2) % HZ - HZ/2) << SHIFT_USEC) / NSEC_PER_USEC; - /* frequency offset (scaled ppm)*/ -static long time_adj; /* tick adjust (scaled 1 / HZ) */ -long time_reftime; /* time at last adjustment (s) */ -long time_adjust; -long time_next_adjust; - -/* - * this routine handles the overflow of the microsecond field - * - * The tricky bits of code to handle the accurate clock support - * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. - * They were originally developed for SUN and DEC kernels. - * All the kudos should go to Dave for this stuff. - * - */ -static void second_overflow(void) -{ - long ltemp; - - /* Bump the maxerror field */ - time_maxerror += time_tolerance >> SHIFT_USEC; - if ( time_maxerror > NTP_PHASE_LIMIT ) { - time_maxerror = NTP_PHASE_LIMIT; - time_status |= STA_UNSYNC; - } - - /* - * Leap second processing. If in leap-insert state at - * the end of the day, the system clock is set back one - * second; if in leap-delete state, the system clock is - * set ahead one second. The microtime() routine or - * external clock driver will insure that reported time - * is always monotonic. The ugly divides should be - * replaced. - */ - switch (time_state) { - - case TIME_OK: - if (time_status & STA_INS) - time_state = TIME_INS; - else if (time_status & STA_DEL) - time_state = TIME_DEL; - break; - - case TIME_INS: - if (xtime.tv_sec % 86400 == 0) { - xtime.tv_sec--; - wall_to_monotonic.tv_sec++; - /* The timer interpolator will make time change gradually instead - * of an immediate jump by one second. - */ - time_interpolator_update(-NSEC_PER_SEC); - time_state = TIME_OOP; - clock_was_set(); - printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); - } - break; - - case TIME_DEL: - if ((xtime.tv_sec + 1) % 86400 == 0) { - xtime.tv_sec++; - wall_to_monotonic.tv_sec--; - /* Use of time interpolator for a gradual change of time */ - time_interpolator_update(NSEC_PER_SEC); - time_state = TIME_WAIT; - clock_was_set(); - printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); - } - break; - - case TIME_OOP: - time_state = TIME_WAIT; - break; - - case TIME_WAIT: - if (!(time_status & (STA_INS | STA_DEL))) - time_state = TIME_OK; - } - - /* - * Compute the phase adjustment for the next second. In - * PLL mode, the offset is reduced by a fixed factor - * times the time constant. In FLL mode the offset is - * used directly. In either mode, the maximum phase - * adjustment for each second is clamped so as to spread - * the adjustment over not more than the number of - * seconds between updates. - */ - if (time_offset < 0) { - ltemp = -time_offset; - if (!(time_status & STA_FLL)) - ltemp >>= SHIFT_KG + time_constant; - if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE) - ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE; - time_offset += ltemp; - time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); - } else { - ltemp = time_offset; - if (!(time_status & STA_FLL)) - ltemp >>= SHIFT_KG + time_constant; - if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE) - ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE; - time_offset -= ltemp; - time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); - } - - /* - * Compute the frequency estimate and additional phase - * adjustment due to frequency error for the next - * second. When the PPS signal is engaged, gnaw on the - * watchdog counter and update the frequency computed by - * the pll and the PPS signal. - */ - pps_valid++; - if (pps_valid == PPS_VALID) { /* PPS signal lost */ - pps_jitter = MAXTIME; - pps_stabil = MAXFREQ; - time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | - STA_PPSWANDER | STA_PPSERROR); - } - ltemp = time_freq + pps_freq; - if (ltemp < 0) - time_adj -= -ltemp >> - (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); - else - time_adj += ltemp >> - (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); - -#if HZ == 100 - /* Compensate for (HZ==100) != (1 << SHIFT_HZ). - * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14) - */ - if (time_adj < 0) - time_adj -= (-time_adj >> 2) + (-time_adj >> 5); - else - time_adj += (time_adj >> 2) + (time_adj >> 5); -#endif -#if HZ == 1000 - /* Compensate for (HZ==1000) != (1 << SHIFT_HZ). - * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14) - */ - if (time_adj < 0) - time_adj -= (-time_adj >> 6) + (-time_adj >> 7); - else - time_adj += (time_adj >> 6) + (time_adj >> 7); -#endif -} /* in the NTP reference this is called "hardclock()" */ static void update_wall_time_one_tick(void) { - long time_adjust_step, delta_nsec; + long delta_nsec; - if ( (time_adjust_step = time_adjust) != 0 ) { - /* We are doing an adjtime thing. - * - * Prepare time_adjust_step to be within bounds. - * Note that a positive time_adjust means we want the clock - * to run faster. - * - * Limit the amount of the step to be in the range - * -tickadj .. +tickadj - */ - if (time_adjust > tickadj) - time_adjust_step = tickadj; - else if (time_adjust < -tickadj) - time_adjust_step = -tickadj; + delta_nsec = tick_nsec + ntp_advance(); - /* Reduce by this step the amount of time left */ - time_adjust -= time_adjust_step; - } - delta_nsec = tick_nsec + time_adjust_step * 1000; - /* - * Advance the phase, once it gets to one microsecond, then - * advance the tick more. - */ - time_phase += time_adj; - if (time_phase <= -FINENSEC) { - long ltemp = -time_phase >> (SHIFT_SCALE - 10); - time_phase += ltemp << (SHIFT_SCALE - 10); - delta_nsec -= ltemp; - } - else if (time_phase >= FINENSEC) { - long ltemp = time_phase >> (SHIFT_SCALE - 10); - time_phase -= ltemp << (SHIFT_SCALE - 10); - delta_nsec += ltemp; - } xtime.tv_nsec += delta_nsec; time_interpolator_update(delta_nsec); - /* Changes by adjtime() do not take effect till next tick. */ - if (time_next_adjust != 0) { - time_adjust = time_next_adjust; - time_next_adjust = 0; - } } /* @@ -1473,7 +1272,7 @@ unsigned long time_interpolator_get_offs #define INTERPOLATOR_ADJUST 65536 #define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST -static void time_interpolator_update(long delta_nsec) +void time_interpolator_update(long delta_nsec) { u64 counter; unsigned long offset;
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |