ntp: cleanup ntp.c

This is mostly a style cleanup of ntp.c and extracts part of do_adjtimex as
ntp_update_offset().  Otherwise the functionality is still the same as before.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index dbd6f890561425aa28a372118eb9a6c4d7206813..2586c30f0658e998cf07636b8f8b5705ed451789 100644 (file)
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -35,7 +35,7 @@ static u64 tick_length, tick_length_base;
 /* 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 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)         */
@@ -57,6 +57,44 @@ static void ntp_update_frequency(void)
        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;
+
+       time_offset = 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 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 = 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))
+               freq_adj += div_s64(time_offset << (SHIFT_NSEC - SHIFT_FLL), mtemp);
+       freq_adj += time_freq;
+       freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
+       time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
+       time_offset = div_s64(time_offset, NTP_INTERVAL_FREQ);
+       time_offset <<= SHIFT_UPDATE;
+}
+
 /**
  * ntp_clear - Clears the NTP state variables
  *
@@ -131,7 +169,7 @@ void second_overflow(void)
                break;
        case TIME_WAIT:
                if (!(time_status & (STA_INS | STA_DEL)))
-               time_state = TIME_OK;
+                       time_state = TIME_OK;
        }
 
        /*
@@ -234,8 +272,7 @@ static inline void notify_cmos_timer(void) { }
  */
 int do_adjtimex(struct timex *txc)
 {
-       long mtemp, save_adjust;
-       s64 freq_adj;
+       long save_adjust;
        int result;
 
        /* In order to modify anything, you gotta be super-user! */
@@ -272,94 +309,63 @@ int do_adjtimex(struct timex *txc)
        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)    /* only set allowed bits */
+                       time_status = (txc->status & ~STA_RONLY) |
+                                     (time_status & STA_RONLY);
+
+               if (txc->modes & ADJ_FREQUENCY) {
+                       if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) {
+                               result = -EINVAL;
+                               goto leave;
+                       }
+                       time_freq = ((s64)txc->freq * NSEC_PER_USEC)
+                                       >> (SHIFT_USEC - SHIFT_NSEC);
                }
-               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;
+
+               if (txc->modes & ADJ_MAXERROR) {
+                       if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) {
+                               result = -EINVAL;
+                               goto leave;
+                       }
+                       time_maxerror = txc->maxerror;
                }
-               time_maxerror = txc->maxerror;
-           }
 
-           if (txc->modes & ADJ_ESTERROR) {
-               if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
-                   result = -EINVAL;
-                   goto leave;
+               if (txc->modes & ADJ_ESTERROR) {
+                       if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
+                               result = -EINVAL;
+                               goto leave;
+                       }
+                       time_esterror = txc->esterror;
                }
-               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_TIMECONST) {
+                       if (txc->constant < 0) {        /* NTP v4 uses values > 6 */
+                               result = -EINVAL;
+                               goto leave;
+                       }
+                       time_constant = min(txc->constant + 4, (long)MAXTC);
                }
-               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() */
-                   time_adjust = txc->offset;
+               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) {
-                   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))
-                       freq_adj += div_s64(time_offset << (SHIFT_NSEC - SHIFT_FLL), mtemp);
-                   freq_adj += time_freq;
-                   freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
-                   time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
-                   time_offset = div_s64(time_offset, NTP_INTERVAL_FREQ);
-                   time_offset <<= SHIFT_UPDATE;
-               } /* 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();
+       }
+leave:
+       if (time_status & (STA_UNSYNC|STA_CLOCKERR))
                result = TIME_ERROR;
 
        if ((txc->modes == ADJ_OFFSET_SINGLESHOT) ||
-                       (txc->modes == ADJ_OFFSET_SS_READ))
+           (txc->modes == ADJ_OFFSET_SS_READ))
                txc->offset = save_adjust;
        else
                txc->offset = ((long)shift_right(time_offset, SHIFT_UPDATE)) *
@@ -384,9 +390,12 @@ leave:     if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
        txc->errcnt        = 0;
        txc->stbcnt        = 0;
        write_sequnlock_irq(&xtime_lock);
+
        do_gettimeofday(&txc->time);
+
        notify_cmos_timer();
-       return(result);
+
+       return result;
 }
 
 static int __init ntp_tick_adj_setup(char *str)