#include <linux/mm.h>
#include <linux/time.h>
+#include <linux/timer.h>
#include <linux/timex.h>
-
-#include <asm/div64.h>
+#include <linux/jiffies.h>
+#include <linux/hrtimer.h>
+#include <linux/capability.h>
+#include <linux/math64.h>
#include <asm/timex.h>
/*
unsigned long tick_nsec; /* ACTHZ period (nsec) */
static u64 tick_length, tick_length_base;
-/* Don't completely fail for HZ > 500. */
-int tickadj = 500/HZ ? : 1; /* microsecs */
+#define MAX_TICKADJ 500 /* microsecs */
+#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
+ TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ)
/*
* phase-lock loop variables
*/
/* TIME_ERROR prevents overwriting the CMOS clock */
-int time_state = TIME_OK; /* clock synchronization status */
+static 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) */
+static long time_tai; /* TAI offset (s) */
+static s64 time_offset; /* time adjustment (ns) */
+static long time_constant = 2; /* pll time constant */
long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
-long time_freq; /* frequency offset (scaled ppm)*/
-long time_reftime; /* time at last adjustment (s) */
+static s64 time_freq; /* frequency offset (scaled ns/s)*/
+static long time_reftime; /* time at last adjustment (s) */
long time_adjust;
-long time_next_adjust;
+static long ntp_tick_adj;
+
+static void ntp_update_frequency(void)
+{
+ u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+ << TICK_LENGTH_SHIFT;
+ second_length += (s64)ntp_tick_adj << TICK_LENGTH_SHIFT;
+ second_length += time_freq;
+
+ tick_length_base = second_length;
+
+ tick_nsec = div_u64(second_length, HZ) >> TICK_LENGTH_SHIFT;
+ tick_length_base = div_u64(tick_length_base, NTP_INTERVAL_FREQ);
+}
+
+static void ntp_update_offset(long offset)
+{
+ long mtemp;
+ s64 freq_adj;
+
+ if (!(time_status & STA_PLL))
+ return;
+
+ if (!(time_status & STA_NANO))
+ offset *= NSEC_PER_USEC;
+
+ /*
+ * Scale the phase adjustment and
+ * clamp to the operating range.
+ */
+ offset = min(offset, MAXPHASE);
+ offset = max(offset, -MAXPHASE);
+
+ /*
+ * Select how the frequency is to be controlled
+ * and in which mode (PLL or FLL).
+ */
+ if (time_status & STA_FREQHOLD || time_reftime == 0)
+ time_reftime = xtime.tv_sec;
+ mtemp = xtime.tv_sec - time_reftime;
+ time_reftime = xtime.tv_sec;
+
+ freq_adj = (s64)offset * mtemp;
+ freq_adj <<= TICK_LENGTH_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant);
+ time_status &= ~STA_MODE;
+ if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
+ freq_adj += div_s64((s64)offset << (TICK_LENGTH_SHIFT - SHIFT_FLL),
+ mtemp);
+ time_status |= STA_MODE;
+ }
+ freq_adj += time_freq;
+ freq_adj = min(freq_adj, MAXFREQ_SCALED);
+ time_freq = max(freq_adj, -MAXFREQ_SCALED);
+
+ time_offset = div_s64((s64)offset << TICK_LENGTH_SHIFT, NTP_INTERVAL_FREQ);
+}
/**
* ntp_clear - Clears the NTP state variables
ntp_update_frequency();
tick_length = tick_length_base;
-}
-
-#define CLOCK_TICK_OVERFLOW (LATCH * HZ - CLOCK_TICK_RATE)
-#define CLOCK_TICK_ADJUST (((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / (s64)CLOCK_TICK_RATE)
-
-void ntp_update_frequency(void)
-{
- tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT;
- tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
- tick_length_base += ((s64)time_freq * NSEC_PER_USEC) << (TICK_LENGTH_SHIFT - SHIFT_USEC);
-
- do_div(tick_length_base, HZ);
-
- tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT;
+ time_offset = 0;
}
/*
*/
void second_overflow(void)
{
- long ltemp, time_adj;
+ s64 time_adj;
/* Bump the maxerror field */
- time_maxerror += time_tolerance >> SHIFT_USEC;
+ time_maxerror += MAXFREQ / NSEC_PER_USEC;
if (time_maxerror > NTP_PHASE_LIMIT) {
time_maxerror = NTP_PHASE_LIMIT;
time_status |= STA_UNSYNC;
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");
}
case TIME_DEL:
if ((xtime.tv_sec + 1) % 86400 == 0) {
xtime.tv_sec++;
+ time_tai--;
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_tai++;
time_state = TIME_WAIT;
break;
case TIME_WAIT:
if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
+ 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.
- */
-
-#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)
+ * Compute the phase adjustment for the next second. The offset is
+ * reduced by a fixed factor times the time constant.
*/
- 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
tick_length = tick_length_base;
- tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10));
-}
-
-/*
- * 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;
+ time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
+ time_offset -= time_adj;
+ tick_length += time_adj;
+
+ if (unlikely(time_adjust)) {
+ if (time_adjust > MAX_TICKADJ) {
+ time_adjust -= MAX_TICKADJ;
+ tick_length += MAX_TICKADJ_SCALED;
+ } else if (time_adjust < -MAX_TICKADJ) {
+ time_adjust += MAX_TICKADJ;
+ tick_length -= MAX_TICKADJ_SCALED;
+ } else {
+ tick_length += (s64)(time_adjust * NSEC_PER_USEC /
+ NTP_INTERVAL_FREQ) << TICK_LENGTH_SHIFT;
+ time_adjust = 0;
+ }
}
}
*/
u64 current_tick_length(void)
{
- u64 ret;
+ return tick_length;
+}
+
+#ifdef CONFIG_GENERIC_CMOS_UPDATE
+
+/* Disable the cmos update - used by virtualization and embedded */
+int no_sync_cmos_clock __read_mostly;
+
+static void sync_cmos_clock(unsigned long dummy);
+
+static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
+
+static void sync_cmos_clock(unsigned long dummy)
+{
+ struct timespec now, next;
+ int fail = 1;
- /* calculate the finest interval NTP will allow.
+ /*
+ * If we have an externally synchronized Linux clock, then update
+ * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+ * called as close as possible to 500 ms before the new second starts.
+ * This code is run on a timer. If the clock is set, that timer
+ * may not expire at the correct time. Thus, we adjust...
*/
- ret = tick_length;
- ret += (u64)(adjtime_adjustment() * 1000) << TICK_LENGTH_SHIFT;
+ if (!ntp_synced())
+ /*
+ * Not synced, exit, do not restart a timer (if one is
+ * running, let it run out).
+ */
+ return;
- return ret;
-}
+ getnstimeofday(&now);
+ if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
+ fail = update_persistent_clock(now);
+
+ next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec;
+ if (next.tv_nsec <= 0)
+ next.tv_nsec += NSEC_PER_SEC;
+ if (!fail)
+ next.tv_sec = 659;
+ else
+ next.tv_sec = 0;
+
+ if (next.tv_nsec >= NSEC_PER_SEC) {
+ next.tv_sec++;
+ next.tv_nsec -= NSEC_PER_SEC;
+ }
+ mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next));
+}
-void __attribute__ ((weak)) notify_arch_cmos_timer(void)
+static void notify_cmos_timer(void)
{
- return;
+ if (!no_sync_cmos_clock)
+ mod_timer(&sync_cmos_timer, jiffies + 1);
}
+#else
+static inline void notify_cmos_timer(void) { }
+#endif
+
/* 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;
+ struct timespec ts;
+ long save_adjust;
int result;
/* In order to modify anything, you gotta be super-user! */
/* 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 )
+ if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) {
+ /* singleshot must not be used with any other mode bits */
+ if (txc->modes & ~ADJ_OFFSET_SS_READ)
return -EINVAL;
+ }
/* if the quartz is off by more than 10% something is VERY wrong ! */
if (txc->modes & ADJ_TICK)
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;
+ save_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;
+ if (txc->modes) {
+ if (txc->modes & ADJ_STATUS) {
+ if ((time_status & STA_PLL) &&
+ !(txc->status & STA_PLL)) {
+ time_state = TIME_OK;
+ time_status = STA_UNSYNC;
+ }
+ /* only set allowed bits */
+ time_status &= STA_RONLY;
+ time_status |= txc->status & ~STA_RONLY;
}
- 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_NANO)
+ time_status |= STA_NANO;
+ if (txc->modes & ADJ_MICRO)
+ time_status &= ~STA_NANO;
- if (txc->modes & ADJ_ESTERROR) {
- if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
- result = -EINVAL;
- goto leave;
+ if (txc->modes & ADJ_FREQUENCY) {
+ time_freq = (s64)txc->freq * PPM_SCALE;
+ time_freq = min(time_freq, MAXFREQ_SCALED);
+ time_freq = max(time_freq, -MAXFREQ_SCALED);
}
- time_esterror = txc->esterror;
- }
- if (txc->modes & ADJ_TIMECONST) { /* p. 24 */
- if (txc->constant < 0) { /* NTP v4 uses values > 6 */
- result = -EINVAL;
- goto leave;
+ if (txc->modes & ADJ_MAXERROR)
+ time_maxerror = txc->maxerror;
+ if (txc->modes & ADJ_ESTERROR)
+ time_esterror = txc->esterror;
+
+ if (txc->modes & ADJ_TIMECONST) {
+ time_constant = txc->constant;
+ if (!(time_status & STA_NANO))
+ time_constant += 4;
+ time_constant = min(time_constant, (long)MAXTC);
+ time_constant = max(time_constant, 0l);
}
- 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;
+
+ if (txc->modes & ADJ_TAI && txc->constant > 0)
+ time_tai = txc->constant;
+
+ if (txc->modes & ADJ_OFFSET) {
+ if (txc->modes == ADJ_OFFSET_SINGLESHOT)
+ /* adjtime() is independent from ntp_adjtime() */
+ time_adjust = txc->offset;
+ else
+ ntp_update_offset(txc->offset);
}
- 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;
-
- if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
- ntp_update_frequency();
- } /* txc->modes */
-leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
+ if (txc->modes & ADJ_TICK)
+ tick_usec = txc->tick;
+
+ if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
+ ntp_update_frequency();
+ }
+
+ result = time_state; /* mostly `TIME_OK' */
+ if (time_status & (STA_UNSYNC|STA_CLOCKERR))
result = TIME_ERROR;
- if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
- txc->offset = save_adjust;
+ if ((txc->modes == ADJ_OFFSET_SINGLESHOT) ||
+ (txc->modes == ADJ_OFFSET_SS_READ))
+ txc->offset = save_adjust;
else {
- txc->offset = shift_right(time_offset, SHIFT_UPDATE);
+ txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
+ TICK_LENGTH_SHIFT);
+ if (!(time_status & STA_NANO))
+ txc->offset /= NSEC_PER_USEC;
}
- txc->freq = time_freq;
+ txc->freq = shift_right((s32)(time_freq >> PPM_SCALE_INV_SHIFT) *
+ (s64)PPM_SCALE_INV,
+ TICK_LENGTH_SHIFT);
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->precision = 1;
+ txc->tolerance = MAXFREQ_SCALED / PPM_SCALE;
txc->tick = tick_usec;
+ txc->tai = time_tai;
/* PPS is not implemented, so these are zero */
txc->ppsfreq = 0;
txc->errcnt = 0;
txc->stbcnt = 0;
write_sequnlock_irq(&xtime_lock);
- do_gettimeofday(&txc->time);
- notify_arch_cmos_timer();
- return(result);
+
+ getnstimeofday(&ts);
+ txc->time.tv_sec = ts.tv_sec;
+ txc->time.tv_usec = ts.tv_nsec;
+ if (!(time_status & STA_NANO))
+ txc->time.tv_usec /= NSEC_PER_USEC;
+
+ notify_cmos_timer();
+
+ return result;
}
+
+static int __init ntp_tick_adj_setup(char *str)
+{
+ ntp_tick_adj = simple_strtol(str, NULL, 0);
+ return 1;
+}
+
+__setup("ntp_tick_adj=", ntp_tick_adj_setup);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff