time: ntp: refactor do_adjtimex()

Impact: cleanup, no functionality changed

do_adjtimex() is currently a monster function with a maze of
branches. Refactor the txc->modes setting aspects of it into
two new helper functions:

	process_adj_status()
	process_adjtimex_modes()

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2512	    114	    136	   2762	    aca	ntp.o.before
   2512	    114	    136	   2762	    aca	ntp.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index fc08eb1..aded09b 100644 (file)
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -332,6 +332,102 @@ static void notify_cmos_timer(void)
 static inline void notify_cmos_timer(void) { }
 #endif
 
+
+/*
+ * Propagate a new txc->status value into the NTP state:
+ */
+static inline void process_adj_status(struct timex *txc, struct timespec *ts)
+{
+       long now;
+
+       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;
+
+       /*
+        * 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;
+
+       time_status |= txc->status & ~STA_RONLY;
+
+       switch (time_state) {
+       case TIME_OK:
+       start_timer:
+               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);
+               } else 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);
+               }
+               break;
+       case TIME_INS:
+       case TIME_DEL:
+               time_state = TIME_OK;
+               goto start_timer;
+       case TIME_WAIT:
+               if (!(time_status & (STA_INS | STA_DEL)))
+                       time_state = TIME_OK;
+               break;
+       case TIME_OOP:
+               hrtimer_restart(&leap_timer);
+               break;
+       }
+}
+/*
+ * Called with the xtime lock held, so we can access and modify
+ * all the global NTP state:
+ */
+static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts)
+{
+       if (txc->modes & ADJ_STATUS)
+               process_adj_status(txc, ts);
+
+       if (txc->modes & ADJ_NANO)
+               time_status |= STA_NANO;
+       if (txc->modes & ADJ_MICRO)
+               time_status &= ~STA_NANO;
+
+       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);
+       }
+
+       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
  * kernel time-keeping variables. used by xntpd.
@@ -383,90 +479,10 @@ int do_adjtimex(struct timex *txc)
                txc->offset = save_adjust;
                goto adj_done;
        }
-       if (txc->modes) {
-               long sec;
-
-               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;
-                       /*
-                        * 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;
-
-                       time_status |= txc->status & ~STA_RONLY;
-
-                       switch (time_state) {
-                       case TIME_OK:
-                       start_timer:
-                               sec = ts.tv_sec;
-                               if (time_status & STA_INS) {
-                                       time_state = TIME_INS;
-                                       sec += 86400 - sec % 86400;
-                                       hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
-                               } else if (time_status & STA_DEL) {
-                                       time_state = TIME_DEL;
-                                       sec += 86400 - (sec + 1) % 86400;
-                                       hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
-                               }
-                               break;
-                       case TIME_INS:
-                       case TIME_DEL:
-                               time_state = TIME_OK;
-                               goto start_timer;
-                               break;
-                       case TIME_WAIT:
-                               if (!(time_status & (STA_INS | STA_DEL)))
-                                       time_state = TIME_OK;
-                               break;
-                       case TIME_OOP:
-                               hrtimer_restart(&leap_timer);
-                               break;
-                       }
-               }
-
-               if (txc->modes & ADJ_NANO)
-                       time_status |= STA_NANO;
-               if (txc->modes & ADJ_MICRO)
-                       time_status &= ~STA_NANO;
 
-               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);
-               }
-
-               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();
-       }
+       /* If there are input parameters, then process them: */
+       if (txc->modes)
+               process_adjtimex_modes(txc, &ts);
 
        txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
                                  NTP_SCALE_SHIFT);