Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[safe/jmp/linux-2.6] / kernel / time / ntp.c
index 87aa5ff..7fc6437 100644 (file)
 /*
- * 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 <linux/jiffies.h>
+#include <linux/capability.h>
+#include <linux/clocksource.h>
+#include <linux/workqueue.h>
 #include <linux/hrtimer.h>
-
-#include <asm/div64.h>
-#include <asm/timex.h>
+#include <linux/jiffies.h>
+#include <linux/math64.h>
+#include <linux/timex.h>
+#include <linux/time.h>
+#include <linux/mm.h>
 
 /*
- * Timekeeping variables
+ * NTP timekeeping variables:
  */
-unsigned long tick_usec = TICK_USEC;           /* USER_HZ period (usec) */
-unsigned long tick_nsec;                       /* ACTHZ period (nsec) */
-static u64 tick_length, tick_length_base;
 
-#define MAX_TICKADJ            500             /* microsecs */
-#define MAX_TICKADJ_SCALED     (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
-                                 TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ)
+/* USER_HZ period (usecs): */
+unsigned long                  tick_usec = TICK_USEC;
+
+/* ACTHZ period (nsecs): */
+unsigned long                  tick_nsec;
+
+u64                            tick_length;
+static u64                     tick_length_base;
+
+static struct hrtimer          leap_timer;
+
+#define MAX_TICKADJ            500LL           /* usecs */
+#define MAX_TICKADJ_SCALED \
+       (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
 
 /*
  * phase-lock loop variables
  */
-/* TIME_ERROR prevents overwriting the CMOS clock */
-static int time_state = TIME_OK;       /* clock synchronization status */
-int time_status = STA_UNSYNC;          /* clock status bits            */
-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)*/
-static long time_reftime;              /* time at last adjustment (s)  */
-long time_adjust;
-
-#define CLOCK_TICK_OVERFLOW    (LATCH * HZ - CLOCK_TICK_RATE)
-#define CLOCK_TICK_ADJUST      (((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / \
-                                       (s64)CLOCK_TICK_RATE)
 
+/*
+ * clock synchronization status
+ *
+ * (TIME_ERROR prevents overwriting the CMOS clock)
+ */
+static int                     time_state = TIME_OK;
+
+/* clock status bits:                                                  */
+int                            time_status = STA_UNSYNC;
+
+/* TAI offset (secs):                                                  */
+static long                    time_tai;
+
+/* time adjustment (nsecs):                                            */
+static s64                     time_offset;
+
+/* pll time constant:                                                  */
+static long                    time_constant = 2;
+
+/* maximum error (usecs):                                              */
+long                           time_maxerror = NTP_PHASE_LIMIT;
+
+/* estimated error (usecs):                                            */
+long                           time_esterror = NTP_PHASE_LIMIT;
+
+/* frequency offset (scaled nsecs/secs):                               */
+static s64                     time_freq;
+
+/* time at last adjustment (secs):                                     */
+static long                    time_reftime;
+
+long                           time_adjust;
+
+/* constant (boot-param configurable) NTP tick adjustment (upscaled)   */
+static s64                     ntp_tick_adj;
+
+/*
+ * NTP methods:
+ */
+
+/*
+ * Update (tick_length, tick_length_base, tick_nsec), based
+ * on (tick_usec, ntp_tick_adj, time_freq):
+ */
 static void ntp_update_frequency(void)
 {
-       u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
-                               << TICK_LENGTH_SHIFT;
-       second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
-       second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
+       u64 second_length;
+       u64 new_base;
+
+       second_length            = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+                                               << NTP_SCALE_SHIFT;
+
+       second_length           += ntp_tick_adj;
+       second_length           += time_freq;
+
+       tick_nsec                = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
+       new_base                 = div_u64(second_length, NTP_INTERVAL_FREQ);
+
+       /*
+        * Don't wait for the next second_overflow, apply
+        * the change to the tick length immediately:
+        */
+       tick_length             += new_base - tick_length_base;
+       tick_length_base         = new_base;
+}
+
+static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
+{
+       time_status &= ~STA_MODE;
 
-       tick_length_base = second_length;
+       if (secs < MINSEC)
+               return 0;
 
-       do_div(second_length, HZ);
-       tick_nsec = second_length >> TICK_LENGTH_SHIFT;
+       if (!(time_status & STA_FLL) && (secs <= MAXSEC))
+               return 0;
 
-       do_div(tick_length_base, NTP_INTERVAL_FREQ);
+       time_status |= STA_MODE;
+
+       return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
+}
+
+static void ntp_update_offset(long offset)
+{
+       s64 freq_adj;
+       s64 offset64;
+       long secs;
+
+       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).
+        */
+       secs = xtime.tv_sec - time_reftime;
+       if (unlikely(time_status & STA_FREQHOLD))
+               secs = 0;
+
+       time_reftime = xtime.tv_sec;
+
+       offset64    = offset;
+       freq_adj    = (offset64 * secs) <<
+                       (NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
+
+       freq_adj    += ntp_update_offset_fll(offset64, secs);
+
+       freq_adj    = min(freq_adj + time_freq, MAXFREQ_SCALED);
+
+       time_freq   = max(freq_adj, -MAXFREQ_SCALED);
+
+       time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
 }
 
 /**
@@ -68,15 +168,62 @@ static void ntp_update_frequency(void)
  */
 void ntp_clear(void)
 {
-       time_adjust = 0;                /* stop active adjtime() */
-       time_status |= STA_UNSYNC;
-       time_maxerror = NTP_PHASE_LIMIT;
-       time_esterror = NTP_PHASE_LIMIT;
+       time_adjust     = 0;            /* stop active adjtime() */
+       time_status     |= STA_UNSYNC;
+       time_maxerror   = NTP_PHASE_LIMIT;
+       time_esterror   = NTP_PHASE_LIMIT;
 
        ntp_update_frequency();
 
-       tick_length = tick_length_base;
-       time_offset = 0;
+       tick_length     = tick_length_base;
+       time_offset     = 0;
+}
+
+/*
+ * 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.
+ */
+static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
+{
+       enum hrtimer_restart res = HRTIMER_NORESTART;
+
+       write_seqlock(&xtime_lock);
+
+       switch (time_state) {
+       case TIME_OK:
+               break;
+       case TIME_INS:
+               xtime.tv_sec--;
+               wall_to_monotonic.tv_sec++;
+               time_state = TIME_OOP;
+               printk(KERN_NOTICE
+                       "Clock: inserting leap second 23:59:60 UTC\n");
+               hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
+               res = HRTIMER_RESTART;
+               break;
+       case TIME_DEL:
+               xtime.tv_sec++;
+               time_tai--;
+               wall_to_monotonic.tv_sec--;
+               time_state = TIME_WAIT;
+               printk(KERN_NOTICE
+                       "Clock: deleting leap second 23:59:59 UTC\n");
+               break;
+       case TIME_OOP:
+               time_tai++;
+               time_state = TIME_WAIT;
+               /* fall through */
+       case TIME_WAIT:
+               if (!(time_status & (STA_INS | STA_DEL)))
+                       time_state = TIME_OK;
+               break;
+       }
+       update_vsyscall(&xtime, clock);
+
+       write_sequnlock(&xtime_lock);
+
+       return res;
 }
 
 /*
@@ -89,262 +236,286 @@ void ntp_clear(void)
  */
 void second_overflow(void)
 {
-       long time_adj;
+       s64 delta;
 
        /* Bump the maxerror field */
-       time_maxerror += MAXFREQ >> SHIFT_USEC;
+       time_maxerror += MAXFREQ / NSEC_PER_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.
+        * Compute the phase adjustment for the next second. The offset is
+        * reduced by a fixed factor times the time constant.
+        */
+       tick_length      = tick_length_base;
+
+       delta            = shift_right(time_offset, SHIFT_PLL + time_constant);
+       time_offset     -= delta;
+       tick_length     += delta;
+
+       if (!time_adjust)
+               return;
+
+       if (time_adjust > MAX_TICKADJ) {
+               time_adjust -= MAX_TICKADJ;
+               tick_length += MAX_TICKADJ_SCALED;
+               return;
+       }
+
+       if (time_adjust < -MAX_TICKADJ) {
+               time_adjust += MAX_TICKADJ;
+               tick_length -= MAX_TICKADJ_SCALED;
+               return;
+       }
+
+       tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
+                                                        << NTP_SCALE_SHIFT;
+       time_adjust = 0;
+}
+
+#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(struct work_struct *work);
+
+static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
+
+static void sync_cmos_clock(struct work_struct *work)
+{
+       struct timespec now, next;
+       int fail = 1;
+
+       /*
+        * 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...
+        */
+       if (!ntp_synced()) {
+               /*
+                * Not synced, exit, do not restart a timer (if one is
+                * running, let it run out).
+                */
+               return;
+       }
+
+       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 - (TICK_NSEC / 2);
+       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;
+       }
+       schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next));
+}
+
+static void notify_cmos_timer(void)
+{
+       if (!no_sync_cmos_clock)
+               schedule_delayed_work(&sync_cmos_work, 0);
+}
+
+#else
+static inline void notify_cmos_timer(void) { }
+#endif
+
+/*
+ * Start the leap seconds timer:
+ */
+static inline void ntp_start_leap_timer(struct timespec *ts)
+{
+       long now = ts->tv_sec;
+
+       if (time_status & STA_INS) {
+               time_state = TIME_INS;
+               now += 86400 - now % 86400;
+               hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
+
+               return;
+       }
+
+       if (time_status & STA_DEL) {
+               time_state = TIME_DEL;
+               now += 86400 - (now + 1) % 86400;
+               hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
+       }
+}
+
+/*
+ * Propagate a new txc->status value into the NTP state:
+ */
+static inline void process_adj_status(struct timex *txc, struct timespec *ts)
+{
+       if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
+               time_state = TIME_OK;
+               time_status = STA_UNSYNC;
+       }
+
+       /*
+        * If we turn on PLL adjustments then reset the
+        * reference time to current time.
         */
+       if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
+               time_reftime = xtime.tv_sec;
+
+       /* only set allowed bits */
+       time_status &= STA_RONLY;
+       time_status |= txc->status & ~STA_RONLY;
+
        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;
+               ntp_start_leap_timer(ts);
                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");
-               }
+               time_state = TIME_OK;
+               ntp_start_leap_timer(ts);
+       case TIME_WAIT:
+               if (!(time_status & (STA_INS | STA_DEL)))
+                       time_state = TIME_OK;
                break;
        case TIME_OOP:
-               time_state = TIME_WAIT;
+               hrtimer_restart(&leap_timer);
                break;
-       case TIME_WAIT:
-               if (!(time_status & (STA_INS | STA_DEL)))
-               time_state = TIME_OK;
-       }
-
-       /*
-        * Compute the phase adjustment for the next second. The offset is
-        * reduced by a fixed factor times the time constant.
-        */
-       tick_length = tick_length_base;
-       time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
-       time_offset -= time_adj;
-       tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);
-
-       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;
-               }
        }
 }
-
 /*
- * 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.
+ * Called with the xtime lock held, so we can access and modify
+ * all the global NTP state:
  */
-u64 current_tick_length(void)
+static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts)
 {
-       return tick_length;
-}
+       if (txc->modes & ADJ_STATUS)
+               process_adj_status(txc, ts);
 
+       if (txc->modes & ADJ_NANO)
+               time_status |= STA_NANO;
 
-void __attribute__ ((weak)) notify_arch_cmos_timer(void)
-{
-       return;
+       if (txc->modes & ADJ_MICRO)
+               time_status &= ~STA_NANO;
+
+       if (txc->modes & ADJ_FREQUENCY) {
+               time_freq = txc->freq * PPM_SCALE;
+               time_freq = min(time_freq, MAXFREQ_SCALED);
+               time_freq = max(time_freq, -MAXFREQ_SCALED);
+       }
+
+       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);
+       }
+
+       if (txc->modes & ADJ_TAI && txc->constant > 0)
+               time_tai = txc->constant;
+
+       if (txc->modes & ADJ_OFFSET)
+               ntp_update_offset(txc->offset);
+
+       if (txc->modes & ADJ_TICK)
+               tick_usec = txc->tick;
+
+       if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
+               ntp_update_frequency();
 }
 
-/* adjtimex mainly allows reading (and writing, if superuser) of
+/*
+ * adjtimex mainly allows reading (and writing, if superuser) of
  * kernel time-keeping variables. used by xntpd.
  */
 int do_adjtimex(struct timex *txc)
 {
-       long mtemp, save_adjust, rem;
-       s64 freq_adj, temp64;
+       struct timespec ts;
        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)
+       /* Validate the data before disabling interrupts */
+       if (txc->modes & ADJ_ADJTIME) {
+               /* 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_READONLY) &&
+                   !capable(CAP_SYS_TIME))
+                       return -EPERM;
+       } else {
+               /* In order to modify anything, you gotta be super-user! */
+                if (txc->modes && !capable(CAP_SYS_TIME))
+                       return -EPERM;
+
+               /*
+                * if the quartz is off by more than 10% then
+                * something is VERY wrong!
+                */
+               if (txc->modes & ADJ_TICK &&
+                   (txc->tick <  900000/USER_HZ ||
+                    txc->tick > 1100000/USER_HZ))
                        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;
+               if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
+                       hrtimer_cancel(&leap_timer);
+       }
+
+       getnstimeofday(&ts);
 
        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_adjust;
+       if (txc->modes & ADJ_ADJTIME) {
+               long 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 & ADJ_OFFSET_READONLY)) {
+                       /* adjtime() is independent from ntp_adjtime() */
+                       time_adjust = txc->offset;
+                       ntp_update_frequency();
                }
-               time_freq = ((s64)txc->freq * NSEC_PER_USEC)
-                               >> (SHIFT_USEC - SHIFT_NSEC);
-           }
-
-           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;
-           }
+               txc->offset = save_adjust;
+       } else {
 
-           if (txc->modes & ADJ_TIMECONST) {   /* p. 24 */
-               if (txc->constant < 0) {        /* NTP v4 uses values > 6 */
-                   result = -EINVAL;
-                   goto leave;
-               }
-               time_constant = min(txc->constant + 4, (long)MAXTC);
-           }
+               /* If there are input parameters, then process them: */
+               if (txc->modes)
+                       process_adjtimex_modes(txc, &ts);
 
-           if (txc->modes & ADJ_OFFSET) {      /* values checked earlier */
-               if (txc->modes == ADJ_OFFSET_SINGLESHOT) {
-                   /* adjtime() is independent from ntp_adjtime() */
-                   time_adjust = txc->offset;
-               }
-               else if (time_status & STA_PLL) {
-                   time_offset = txc->offset * NSEC_PER_USEC;
-
-                   /*
-                    * Scale the phase adjustment and
-                    * clamp to the operating range.
-                    */
-                   time_offset = min(time_offset, (s64)MAXPHASE * NSEC_PER_USEC);
-                   time_offset = max(time_offset, (s64)-MAXPHASE * NSEC_PER_USEC);
-
-                   /*
-                    * 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;
-
-                   freq_adj = time_offset * mtemp;
-                   freq_adj = shift_right(freq_adj, time_constant * 2 +
-                                          (SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
-                   if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
-                       temp64 = time_offset << (SHIFT_NSEC - SHIFT_FLL);
-                       if (time_offset < 0) {
-                           temp64 = -temp64;
-                           do_div(temp64, mtemp);
-                           freq_adj -= temp64;
-                       } else {
-                           do_div(temp64, mtemp);
-                           freq_adj += temp64;
-                       }
-                   }
-                   freq_adj += time_freq;
-                   freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
-                   time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
-                   time_offset = div_long_long_rem_signed(time_offset,
-                                                          NTP_INTERVAL_FREQ,
-                                                          &rem);
-                   time_offset <<= SHIFT_UPDATE;
-               } /* STA_PLL */
-           } /* txc->modes & ADJ_OFFSET */
-           if (txc->modes & ADJ_TICK)
-               tick_usec = txc->tick;
+               txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
+                                 NTP_SCALE_SHIFT);
+               if (!(time_status & STA_NANO))
+                       txc->offset /= NSEC_PER_USEC;
+       }
 
-           if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
-                   ntp_update_frequency();
-       } /* txc->modes */
-leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
+       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;
-       else
-               txc->offset = ((long)shift_right(time_offset, SHIFT_UPDATE)) *
-                               NTP_INTERVAL_FREQ / 1000;
-       txc->freq          = (time_freq / NSEC_PER_USEC) <<
-                               (SHIFT_USEC - SHIFT_NSEC);
+       txc->freq          = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
+                                        PPM_SCALE_INV, NTP_SCALE_SHIFT);
        txc->maxerror      = time_maxerror;
        txc->esterror      = time_esterror;
        txc->status        = time_status;
        txc->constant      = time_constant;
        txc->precision     = 1;
-       txc->tolerance     = MAXFREQ;
+       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;
@@ -355,8 +526,32 @@ leave:     if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 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);
+
+       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);
+       ntp_tick_adj <<= NTP_SCALE_SHIFT;
+
+       return 1;
+}
+
+__setup("ntp_tick_adj=", ntp_tick_adj_setup);
+
+void __init ntp_init(void)
+{
+       ntp_clear();
+       hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+       leap_timer.function = ntp_leap_second;
 }