[PATCH] wall_to_monotonic initialization fixes for

From: Tim Schmielau <tim@physik3.uni-rostock.de>

This patch adds (or fixes) initialization of wall_to_monotonic for a few
more architectures.

This should get rid of the strange uptime>14600 days reports, except on arm
whose arch file layout is too unfamiliar to me.

The patch is blessed by George Anzinger, but untested due to lack of
hardware.

arch/alpha/kernel/time.c

@@ -451,8 +451,9 @@ do_gettimeofday(struct timeval *tv)
 int
 do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
 	unsigned long delta_nsec;
-	long sec, nsec;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
@@ -474,31 +475,19 @@ do_settimeofday(struct timespec *tv)
 	delta_nsec *= 1000;
 #endif
 
-	sec = tv->tv_sec;
-	nsec = tv->tv_nsec;
 	nsec -= delta_nsec;
-	if (nsec < 0) {
-		nsec += NSEC_PER_SEC;
-		sec -= 1;
-	}
 
-	xtime.tv_sec = sec;
-	xtime.tv_nsec = nsec;
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;
 	time_esterror = NTP_PHASE_LIMIT;
 
-        wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-        wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
-        if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-                wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-                wall_to_monotonic.tv_sec++;
-        } else if (wall_to_monotonic.tv_nsec < 0) {
-                wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-                wall_to_monotonic.tv_sec--;
-        }
-
 	write_sequnlock_irq(&xtime_lock);
 	return 0;
 }

arch/i386/kernel/time.c

@@ -115,6 +115,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -125,28 +128,15 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= cur_timer->get_offset() * NSEC_PER_USEC;
-	tv->tv_nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
-
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	nsec -= cur_timer->get_offset() * NSEC_PER_USEC;
+	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
-	wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-	wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 
-	if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-		wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec++;
-	}
-	if (wall_to_monotonic.tv_nsec < 0) {
-		wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec--;
-	}
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;

arch/ia64/kernel/time.c

@@ -104,21 +104,6 @@ static struct time_interpolator itc_interpolator = {
 	.reset =	itc_reset
 };
 
-static inline void
-set_normalized_timespec (struct timespec *ts, time_t sec, long nsec)
-{
-	while (nsec > NSEC_PER_SEC) {
-		nsec -= NSEC_PER_SEC;
-		++sec;
-	}
-	while (nsec < 0) {
-		nsec += NSEC_PER_SEC;
-		--sec;
-	}
-	ts->tv_sec = sec;
-	ts->tv_nsec = nsec;
-}
-
 int
 do_settimeofday (struct timespec *tv)
 {

arch/m68k/kernel/time.c

@@ -103,6 +103,7 @@ void time_init(void)
 				      time.tm_hour, time.tm_min, time.tm_sec);
 		xtime.tv_nsec = 0;
 	}
+	wall_to_monotonic.tv_sec = -xtime.tv_sec;
 
 	mach_sched_init(timer_interrupt);
 }
@@ -140,6 +141,8 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
 	extern unsigned long wall_jiffies;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
@@ -152,16 +155,15 @@ int do_settimeofday(struct timespec *tv)
 	 * Discover what correction gettimeofday
 	 * would have done, and then undo it!
 	 */
-	tv->tv_nsec -= 1000 * (mach_gettimeoffset() +
+	nsec -= 1000 * (mach_gettimeoffset() +
 			(jiffies - wall_jiffies) * (1000000 / HZ));
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;

arch/m68knommu/kernel/time.c

@@ -131,6 +131,7 @@ void time_init(void)
 		year += 100;
 	xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
 	xtime.tv_nsec = 0;
+	wall_to_monotonic.tv_sec = -xtime.tv_sec;
 
 	mach_sched_init(timer_interrupt);
 }
@@ -165,6 +166,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -177,15 +181,14 @@ int do_settimeofday(struct timespec *tv)
 	 * would have done, and then undo it!
 	 */
 	if (mach_gettimeoffset)
-		tv->tv_nsec -= (mach_gettimeoffset() * 1000);
+		nsec -= (mach_gettimeoffset() * 1000);
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;

arch/mips/kernel/time.c

@@ -98,6 +98,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -108,16 +111,15 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= do_gettimeoffset() * NSEC_PER_USEC;
-	tv->tv_nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
+	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
+	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;
@@ -500,6 +502,9 @@ void __init time_init(void)
 	xtime.tv_sec = rtc_get_time();
 	xtime.tv_nsec = 0;
 
+        set_normalized_timespec(&wall_to_monotonic,
+                                -xtime.tv_sec, -xtime.tv_nsec);
+
 	/* choose appropriate gettimeoffset routine */
 	if (!cpu_has_counter) {
 		/* no cpu counter - sorry */

arch/mips64/kernel/time.c

@@ -98,6 +98,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -108,16 +111,15 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= do_gettimeoffset() * NSEC_PER_USEC;
-	tv->tv_nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
+	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
+	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - tsec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;
@@ -499,6 +501,8 @@ void __init time_init(void)
 
 	xtime.tv_sec = rtc_get_time();
 	xtime.tv_nsec = 0;
+	set_normalized_timespec(&wall_to_monotonic,
+	                        -xtime.tv_sec, -xtime.tv_nsec);
 
 	/* choose appropriate gettimeoffset routine */
 	if (!cpu_has_counter) {

arch/parisc/kernel/time.c

@@ -190,6 +190,9 @@ do_gettimeofday (struct timeval *tv)
 int
 do_settimeofday (struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -202,16 +205,15 @@ do_settimeofday (struct timespec *tv)
 		 * Discover what correction gettimeofday would have
 		 * done, and then undo it!
 		 */
-		tv->tv_nsec -= gettimeoffset() * 1000;
-		tv->tv_nsec -= (jiffies - wall_jiffies) * (NSEC_PER_SEC / HZ);
+		nsec -= gettimeoffset() * 1000;
+		nsec -= (jiffies - wall_jiffies) * (NSEC_PER_SEC / HZ);
 
-		while (tv->tv_nsec < 0) {
-			tv->tv_nsec += NSEC_PER_SEC;
-			tv->tv_sec--;
-		}
+		wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+		wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+		set_normalized_timespec(&xtime, sec, nsec);
+		set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-		xtime.tv_sec = tv->tv_sec;
-		xtime.tv_nsec = tv->tv_nsec;
 		time_adjust = 0;		/* stop active adjtime() */
 		time_status |= STA_UNSYNC;
 		time_maxerror = NTP_PHASE_LIMIT;
@@ -243,6 +245,8 @@ void __init time_init(void)
 		write_seqlock_irq(&xtime_lock);
 		xtime.tv_sec = tod_data.tod_sec;
 		xtime.tv_nsec = tod_data.tod_usec * 1000;
+		set_normalized_timespec(&wall_to_monotonic,
+		                        -xtime.tv_sec, -xtime.tv_nsec);
 		write_sequnlock_irq(&xtime_lock);
 	} else {
 		printk(KERN_ERR "Error reading tod clock\n");

arch/ppc/kernel/time.c

@@ -241,6 +241,8 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, new_sec = tv->tv_sec;
+	long wtm_nsec, new_nsec = tv->tv_nsec;
 	unsigned long flags;
 	int tb_delta, new_nsec, new_sec;
 
@@ -268,14 +270,14 @@ int do_settimeofday(struct timespec *tv)
 	 */
 	tb_delta = tb_ticks_since(last_jiffy_stamp(smp_processor_id()));
 	tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
-	new_sec = tv->tv_sec;
-	new_nsec = tv->tv_nsec - 1000 * mulhwu(tb_to_us, tb_delta);
-	while (new_nsec < 0) {
-		new_sec--; 
-		new_nsec += NSEC_PER_SEC;
-	}
-	xtime.tv_nsec = new_nsec;
-	xtime.tv_sec = new_sec;
+
+	new_nsec -= 1000 * mulhwu(tb_to_us, tb_delta);
+
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
+
+	set_normalized_timespec(&xtime, new_sec, new_nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
 	/* In case of a large backwards jump in time with NTP, we want the 
 	 * clock to be updated as soon as the PLL is again in lock.
@@ -347,6 +349,8 @@ void __init time_init(void)
 		sys_tz.tz_dsttime = 0;
 		xtime.tv_sec -= time_offset;
         }
+        set_normalized_timespec(&wall_to_monotonic,
+                                -xtime.tv_sec, -xtime.tv_nsec);
 }
 
 #define FEBRUARY		2

arch/ppc64/kernel/time.c

@@ -339,9 +339,11 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, new_sec = tv->tv_sec;
+	long wtm_nsec, new_nsec = tv->tv_nsec;
 	unsigned long flags;
 	unsigned long delta_xsec;
-	long int tb_delta, new_nsec, new_sec;
+	long int tb_delta;
 	unsigned long new_xsec;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
@@ -364,14 +366,13 @@ int do_settimeofday(struct timespec *tv)
 	tb_delta = tb_ticks_since(tb_last_stamp);
 	tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
 
-	new_sec = tv->tv_sec;
-	new_nsec = tv->tv_nsec - (tb_delta / tb_ticks_per_usec / 1000);
-	while (new_nsec < 0) {
-		new_sec--; 
-		new_nsec += NSEC_PER_SEC;
-	}
-	xtime.tv_nsec = new_nsec;
-	xtime.tv_sec = new_sec;
+	new_nsec -= tb_delta / tb_ticks_per_usec / 1000;
+
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
+
+ 	set_normalized_timespec(&xtime, new_sec, new_nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
 	/* In case of a large backwards jump in time with NTP, we want the 
 	 * clock to be updated as soon as the PLL is again in lock.
@@ -484,6 +485,8 @@ void __init time_init(void)
 
 	xtime.tv_nsec = 0;
 	last_rtc_update = xtime.tv_sec;
+	set_normalized_timespec(&wall_to_monotonic,
+	                        -xtime.tv_sec, -xtime.tv_nsec);
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
 	/* Not exact, but the timer interrupt takes care of this */

arch/s390/kernel/time.c

@@ -104,6 +104,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -114,15 +117,14 @@ int do_settimeofday(struct timespec *tv)
 	 * Discover what correction gettimeofday
 	 * would have done, and then undo it!
 	 */
-	tv->tv_nsec -= do_gettimeoffset() * 1000;
+	nsec -= do_gettimeoffset() * 1000;
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;
@@ -263,6 +265,8 @@ void __init time_init(void)
 	set_time_cc = init_timer_cc - 0x8126d60e46000000LL +
 		(0x3c26700LL*1000000*4096);
         tod_to_timeval(set_time_cc, &xtime);
+        set_normalized_timespec(&wall_to_monotonic,
+                                -xtime.tv_sec, -xtime.tv_nsec);
 
         /* request the 0x1004 external interrupt */
         if (register_early_external_interrupt(0x1004, do_comparator_interrupt,

arch/sh/kernel/time.c

@@ -179,6 +179,9 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -189,16 +192,15 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= 1000 * (do_gettimeoffset() +
+	nsec -= 1000 * (do_gettimeoffset() +
 			(jiffies - wall_jiffies) * (1000000 / HZ));
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;
@@ -418,6 +420,9 @@ void __init time_init(void)
 
 	rtc_get_time(&xtime);
 
+        set_normalized_timespec(&wall_to_monotonic,
+                                -xtime.tv_sec, -xtime.tv_nsec);
+
 	if (board_timer_setup) {
 		board_timer_setup(&irq0);
 	} else {

arch/sparc/kernel/time.c

@@ -408,9 +408,9 @@ void __init sbus_time_init(void)
 	mon = MSTK_REG_MONTH(mregs);
 	year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
 	xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
-	wall_to_monotonic.tv_sec = -xtime.tv_sec;
 	xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
-	wall_to_monotonic.tv_nsec = -xtime.tv_nsec;
+        set_normalized_timespec(&wall_to_monotonic,
+                                -xtime.tv_sec, -xtime.tv_nsec);
 	mregs->creg &= ~MSTK_CREG_READ;
 	spin_unlock_irq(&mostek_lock);
 #ifdef CONFIG_SUN4
@@ -441,9 +441,9 @@ void __init sbus_time_init(void)
 		intersil_start(iregs);
 
 		xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
-		wall_to_monotonic.tv_sec = -xtime.tv_sec;
 		xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
-		wall_to_monotonic.tv_nsec = -xtime.tv_nsec;
+	        set_normalized_timespec(&wall_to_monotonic,
+ 	                               -xtime.tv_sec, -xtime.tv_nsec);
 		printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec);
 	}
 #endif
@@ -512,6 +512,9 @@ int do_settimeofday(struct timespec *tv)
 
 static int sbus_do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -521,28 +524,15 @@ static int sbus_do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= 1000 * (do_gettimeoffset() +
+	nsec -= 1000 * (do_gettimeoffset() +
 			(jiffies - wall_jiffies) * (USEC_PER_SEC / HZ));
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
-
-	wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-	wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 
-	if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-		wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec++;
-	}
-	if (wall_to_monotonic.tv_nsec < 0) {
-		wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec--;
-	}
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;

arch/sparc64/kernel/time.c

@@ -703,9 +703,9 @@ static void __init set_system_time(void)
 	}
 
 	xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
-	wall_to_monotonic.tv_sec = -xtime.tv_sec;
 	xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
-	wall_to_monotonic.tv_nsec = -xtime.tv_nsec;
+	set_normalized_timespec(&wall_to_monotonic,
+ 	                        -xtime.tv_sec, -xtime.tv_nsec);
 
 	if (mregs) {
 		tmp = mostek_read(mregs + MOSTEK_CREG);
@@ -743,9 +743,9 @@ void __init clock_probe(void)
 			(unsigned int) (long) &unix_tod);
 		prom_feval(obp_gettod);
 		xtime.tv_sec = unix_tod;
-		wall_to_monotonic.tv_sec = -xtime.tv_sec;
 		xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
-		wall_to_monotonic.tv_nsec = -xtime.tv_nsec;
+		set_normalized_timespec(&wall_to_monotonic,
+		                        -xtime.tv_sec, -xtime.tv_nsec);
 		return;
 	}
 
@@ -1090,6 +1090,9 @@ static __inline__ unsigned long do_gettimeoffset(void)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
@@ -1103,28 +1106,15 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	tv->tv_nsec -= do_gettimeoffset() * 1000;
-	tv->tv_nsec -= (jiffies - wall_jiffies) * (NSEC_PER_SEC / HZ);
-
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
+	nsec -= do_gettimeoffset() * 1000;
+	nsec -= (jiffies - wall_jiffies) * (NSEC_PER_SEC / HZ);
 
-	wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-	wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 
-	if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-		wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec++;
-	}
-	if (wall_to_monotonic.tv_nsec < 0) {
-		wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec--;
-	}
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
 	time_maxerror = NTP_PHASE_LIMIT;

arch/x86_64/kernel/time.c

@@ -125,33 +125,22 @@ void do_gettimeofday(struct timeval *tv)
 
 int do_settimeofday(struct timespec *tv)
 {
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
 	write_seqlock_irq(&xtime_lock);
 
-	tv->tv_nsec -= do_gettimeoffset() * 1000 +
+	nsec -= do_gettimeoffset() * 1000 +
 		(jiffies - wall_jiffies) * (NSEC_PER_SEC/HZ);
 
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
-
-	wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-	wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
-
-	if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-		wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec++;
-	}
-	if (wall_to_monotonic.tv_nsec < 0) {
-		wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec--;
-	}
+	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
 	time_adjust = 0;		/* stop active adjtime() */
 	time_status |= STA_UNSYNC;
@@ -603,8 +592,8 @@ void __init time_init(void)
 	xtime.tv_sec = get_cmos_time();
 	xtime.tv_nsec = 0;
 
-	wall_to_monotonic.tv_sec = -xtime.tv_sec;
-	wall_to_monotonic.tv_nsec = -xtime.tv_nsec;
+	set_normalized_timespec(&wall_to_monotonic,
+	                        -xtime.tv_sec, -xtime.tv_nsec);
 
 	if (!hpet_init()) {
                 vxtime_hz = (1000000000000000L + hpet_period / 2) /

include/linux/time.h

@@ -217,6 +217,21 @@ extern void clock_was_set(void); // call when ever the clock is set
 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
 extern long do_nanosleep(struct timespec *t);
 extern long do_utimes(char __user * filename, struct timeval * times);
+
+static inline void
+set_normalized_timespec (struct timespec *ts, time_t sec, long nsec)
+{
+	while (nsec > NSEC_PER_SEC) {
+		nsec -= NSEC_PER_SEC;
+		++sec;
+	}
+	while (nsec < 0) {
+		nsec += NSEC_PER_SEC;
+		--sec;
+	}
+	ts->tv_sec = sec;
+	ts->tv_nsec = nsec;
+}
 #endif
 
 #define FD_SETSIZE		__FD_SETSIZE