diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time.c | 173 | ||||
| -rw-r--r-- | kernel/time/Makefile | 2 | ||||
| -rw-r--r-- | kernel/time/ntp.c | 389 | ||||
| -rw-r--r-- | kernel/timer.c | 211 |
4 files changed, 391 insertions, 384 deletions
diff --git a/kernel/time.c b/kernel/time.c index 5bd489747643..0e017bff4c19 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -202,179 +202,6 @@ asmlinkage long sys_settimeofday(struct timeval __user *tv, return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); } -/* we call this to notify the arch when the clock is being - * controlled. If no such arch routine, do nothing. - */ -void __attribute__ ((weak)) notify_arch_cmos_timer(void) -{ - return; -} - -/* adjtimex mainly allows reading (and writing, if superuser) of - * kernel time-keeping variables. used by xntpd. - */ -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; - } - - 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) { - ltemp = 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); - time_freq += shift_right(ltemp, SHIFT_KH); - } else /* calibration interval too short (p. 12) */ - result = TIME_ERROR; - } else { /* PLL mode */ - if (mtemp < MAXSEC) { - ltemp *= mtemp; - time_freq += shift_right(ltemp,(time_constant + - time_constant + - SHIFT_KF - SHIFT_USEC)); - } else /* calibration interval too long (p. 12) */ - result = TIME_ERROR; - } - time_freq = min(time_freq, time_tolerance); - time_freq = max(time_freq, -time_tolerance); - } /* STA_PLL */ - } /* 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) - result = TIME_ERROR; - - if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) - txc->offset = save_adjust; - else { - txc->offset = shift_right(time_offset, SHIFT_UPDATE); - } - txc->freq = time_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; - - /* PPS is not implemented, so these are zero */ - txc->ppsfreq = 0; - txc->jitter = 0; - txc->shift = 0; - txc->stabil = 0; - txc->jitcnt = 0; - txc->calcnt = 0; - txc->errcnt = 0; - txc->stbcnt = 0; - write_sequnlock_irq(&xtime_lock); - do_gettimeofday(&txc->time); - notify_arch_cmos_timer(); - return(result); -} - asmlinkage long sys_adjtimex(struct timex __user *txc_p) { struct timex txc; /* Local copy of parameter */ diff --git a/kernel/time/Makefile b/kernel/time/Makefile index e1dfd8e86cce..61a3907d16fb 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1 +1 @@ -obj-y += clocksource.o jiffies.o +obj-y += ntp.o clocksource.o jiffies.o diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c new file mode 100644 index 000000000000..8ccce15b4b23 --- /dev/null +++ b/kernel/time/ntp.c @@ -0,0 +1,389 @@ +/* + * linux/kernel/time/ntp.c + * + * NTP state machine interfaces and logic. + * + * This code was mainly moved from kernel/timer.c and kernel/time.c + * Please see those files for relevant copyright info and historical + * changelogs. + */ + +#include <linux/mm.h> +#include <linux/time.h> +#include <linux/timex.h> + +#include <asm/div64.h> +#include <asm/timex.h> + +/* 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) */ +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. + */ +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. + */ + ltemp = time_offset; + if (!(time_status & STA_FLL)) + ltemp = shift_right(ltemp, SHIFT_KG + time_constant); + ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE); + ltemp = max(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. + */ + ltemp = time_freq; + time_adj += shift_right(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) + */ + time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5); +#endif +#if HZ == 250 + /* + * Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and + * 0.78125% to get 255.85938; => only 0.05% error (p. 14) + */ + time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); +#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) + */ + time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); +#endif +} + +/* + * Returns how many microseconds we need to add to xtime this tick + * in doing an adjustment requested with adjtime. + */ +static long adjtime_adjustment(void) +{ + long time_adjust_step; + + time_adjust_step = time_adjust; + if (time_adjust_step) { + /* + * 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 + */ + time_adjust_step = min(time_adjust_step, (long)tickadj); + time_adjust_step = max(time_adjust_step, (long)-tickadj); + } + return time_adjust_step; +} + +/* in the NTP reference this is called "hardclock()" */ +void update_ntp_one_tick(void) +{ + long time_adjust_step; + + time_adjust_step = adjtime_adjustment(); + if (time_adjust_step) + /* Reduce by this step the amount of time left */ + time_adjust -= time_adjust_step; + + /* 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 how long ticks are at the moment, that is, how much time + * update_wall_time_one_tick will add to xtime next time we call it + * (assuming no calls to do_adjtimex in the meantime). + * The return value is in fixed-point nanoseconds shifted by the + * specified number of bits to the right of the binary point. + * This function has no side-effects. + */ +u64 current_tick_length(void) +{ + long delta_nsec; + u64 ret; + + /* calculate the finest interval NTP will allow. + * ie: nanosecond value shifted by (SHIFT_SCALE - 10) + */ + delta_nsec = tick_nsec + adjtime_adjustment() * 1000; + ret = (u64)delta_nsec << TICK_LENGTH_SHIFT; + ret += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10)); + + return ret; +} + + +void __attribute__ ((weak)) notify_arch_cmos_timer(void) +{ + return; +} + +/* adjtimex mainly allows reading (and writing, if superuser) of + * kernel time-keeping variables. used by xntpd. + */ +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; + } + + 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) { + ltemp = 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); + time_freq += shift_right(ltemp, SHIFT_KH); + } else /* calibration interval too short (p. 12) */ + result = TIME_ERROR; + } else { /* PLL mode */ + if (mtemp < MAXSEC) { + ltemp *= mtemp; + time_freq += shift_right(ltemp,(time_constant + + time_constant + + SHIFT_KF - SHIFT_USEC)); + } else /* calibration interval too long (p. 12) */ + result = TIME_ERROR; + } + time_freq = min(time_freq, time_tolerance); + time_freq = max(time_freq, -time_tolerance); + } /* STA_PLL */ + } /* 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) + result = TIME_ERROR; + + if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) + txc->offset = save_adjust; + else { + txc->offset = shift_right(time_offset, SHIFT_UPDATE); + } + txc->freq = time_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; + + /* PPS is not implemented, so these are zero */ + txc->ppsfreq = 0; + txc->jitter = 0; + txc->shift = 0; + txc->stabil = 0; + txc->jitcnt = 0; + txc->calcnt = 0; + txc->errcnt = 0; + txc->stbcnt = 0; + write_sequnlock_irq(&xtime_lock); + do_gettimeofday(&txc->time); + notify_arch_cmos_timer(); + return(result); +} diff --git a/kernel/timer.c b/kernel/timer.c index 4f55622b0d38..5fccc7cbf3b4 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -41,12 +41,6 @@ #include <asm/timex.h> #include <asm/io.h> -#ifdef CONFIG_TIME_INTERPOLATION -static void time_interpolator_update(long delta_nsec); -#else -#define time_interpolator_update(x) -#endif - u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; EXPORT_SYMBOL(jiffies_64); @@ -587,209 +581,6 @@ struct timespec wall_to_monotonic __attribute__ ((aligned (16))); 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) */ -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. - */ - ltemp = time_offset; - if (!(time_status & STA_FLL)) - ltemp = shift_right(ltemp, SHIFT_KG + time_constant); - ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE); - ltemp = max(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. - */ - ltemp = time_freq; - time_adj += shift_right(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) - */ - time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5); -#endif -#if HZ == 250 - /* - * Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and - * 0.78125% to get 255.85938; => only 0.05% error (p. 14) - */ - time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); -#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) - */ - time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); -#endif -} - -/* - * Returns how many microseconds we need to add to xtime this tick - * in doing an adjustment requested with adjtime. - */ -static long adjtime_adjustment(void) -{ - long time_adjust_step; - - time_adjust_step = time_adjust; - if (time_adjust_step) { - /* - * 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 - */ - time_adjust_step = min(time_adjust_step, (long)tickadj); - time_adjust_step = max(time_adjust_step, (long)-tickadj); - } - return time_adjust_step; -} - -/* in the NTP reference this is called "hardclock()" */ -static void update_ntp_one_tick(void) -{ - long time_adjust_step; - - time_adjust_step = adjtime_adjustment(); - if (time_adjust_step) - /* Reduce by this step the amount of time left */ - time_adjust -= time_adjust_step; - - /* 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 how long ticks are at the moment, that is, how much time - * update_wall_time_one_tick will add to xtime next time we call it - * (assuming no calls to do_adjtimex in the meantime). - * The return value is in fixed-point nanoseconds shifted by the - * specified number of bits to the right of the binary point. - * This function has no side-effects. - */ -u64 current_tick_length(void) -{ - long delta_nsec; - u64 ret; - - /* calculate the finest interval NTP will allow. - * ie: nanosecond value shifted by (SHIFT_SCALE - 10) - */ - delta_nsec = tick_nsec + adjtime_adjustment() * 1000; - ret = (u64)delta_nsec << TICK_LENGTH_SHIFT; - ret += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10)); - - return ret; -} /* XXX - all of this timekeeping code should be later moved to time.c */ #include <linux/clocksource.h> @@ -1775,7 +1566,7 @@ unsigned long time_interpolator_get_offset(void) #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; |
