kprobes: codingstyle cleanups
[powerpc.git] / kernel / time / ntp.c
index 238ce47..cb25649 100644 (file)
@@ -22,25 +22,42 @@ unsigned long tick_usec = TICK_USEC;                /* USER_HZ period (usec) */
 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 (ns)         */
-long time_constant = 2;                        /* pll time constant            */
-long time_tolerance = MAXFREQ;         /* frequency tolerance (ppm)    */
-long time_precision = 1;               /* clock precision (us)         */
+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 long time_reftime;              /* time at last adjustment (s)  */
 long time_adjust;
-long time_next_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)
+
+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);
+
+       tick_length_base = second_length;
+
+       do_div(second_length, HZ);
+       tick_nsec = second_length >> TICK_LENGTH_SHIFT;
+
+       do_div(tick_length_base, NTP_INTERVAL_FREQ);
+}
 
 /**
  * ntp_clear - Clears the NTP state variables
@@ -60,20 +77,6 @@ void ntp_clear(void)
        time_offset = 0;
 }
 
-#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;
-}
-
 /*
  * this routine handles the overflow of the microsecond field
  *
@@ -87,7 +90,7 @@ void second_overflow(void)
        long time_adj;
 
        /* Bump the maxerror field */
-       time_maxerror += time_tolerance >> SHIFT_USEC;
+       time_maxerror += MAXFREQ >> SHIFT_USEC;
        if (time_maxerror > NTP_PHASE_LIMIT) {
                time_maxerror = NTP_PHASE_LIMIT;
                time_status |= STA_UNSYNC;
@@ -146,60 +149,26 @@ void second_overflow(void)
        }
 
        /*
-        * 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.
+        * 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 = time_offset;
-       if (!(time_status & STA_FLL))
-               time_adj = shift_right(time_adj, SHIFT_KG + time_constant);
-       time_adj = min(time_adj, -((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
-       time_adj = max(time_adj, ((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
+       time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
        time_offset -= time_adj;
        tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);
-}
-
-/*
- * 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;
+       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;
+               }
        }
 }
 
@@ -213,14 +182,7 @@ void update_ntp_one_tick(void)
  */
 u64 current_tick_length(void)
 {
-       u64 ret;
-
-       /* calculate the finest interval NTP will allow.
-        */
-       ret = tick_length;
-       ret += (u64)(adjtime_adjustment() * 1000) << TICK_LENGTH_SHIFT;
-
-       return ret;
+       return tick_length;
 }
 
 
@@ -234,7 +196,8 @@ void __attribute__ ((weak)) notify_arch_cmos_timer(void)
  */
 int do_adjtimex(struct timex *txc)
 {
-       long ltemp, mtemp, save_adjust;
+       long mtemp, save_adjust, rem;
+       s64 freq_adj, temp64;
        int result;
 
        /* In order to modify anything, you gotta be super-user! */
@@ -263,7 +226,7 @@ int do_adjtimex(struct timex *txc)
        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 */
@@ -280,7 +243,8 @@ int do_adjtimex(struct timex *txc)
                    result = -EINVAL;
                    goto leave;
                }
-               time_freq = txc->freq;
+               time_freq = ((s64)txc->freq * NSEC_PER_USEC)
+                               >> (SHIFT_USEC - SHIFT_NSEC);
            }
 
            if (txc->modes & ADJ_MAXERROR) {
@@ -304,24 +268,23 @@ int do_adjtimex(struct timex *txc)
                    result = -EINVAL;
                    goto leave;
                }
-               time_constant = txc->constant;
+               time_constant = min(txc->constant + 4, (long)MAXTC);
            }
 
            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;
+                   time_adjust = txc->offset;
                }
                else if (time_status & STA_PLL) {
-                   ltemp = txc->offset;
+                   time_offset = txc->offset * NSEC_PER_USEC;
 
                    /*
                     * Scale the phase adjustment and
                     * clamp to the operating range.
                     */
-                   time_offset = min(ltemp, MAXPHASE);
-                   time_offset = max(time_offset, -MAXPHASE);
+                   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
@@ -333,24 +296,28 @@ int do_adjtimex(struct timex *txc)
                        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 << 12) / mtemp) << (SHIFT_USEC - 12);
-                           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;
+
+                   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;
+                       }
                    }
-                   time_freq = min(time_freq, time_tolerance);
-                   time_freq = max(time_freq, -time_tolerance);
-                   time_offset = (time_offset * NSEC_PER_USEC / HZ) << SHIFT_UPDATE;
+                   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)
@@ -363,16 +330,18 @@ 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;
+               txc->offset = save_adjust;
        else
-           txc->offset    = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000;
-       txc->freq          = time_freq;
+               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->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;
        txc->tick          = tick_usec;
 
        /* PPS is not implemented, so these are zero */