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>

1 files changed, 91 insertions, 82 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index dbd6f8905614..2586c30f0658 100644
--- 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)