[PATCH] NTP: Move all the NTP related code to ntp.c (4c7ee8de) · Commits · e / devices / android_kernel_fairphone_FP4

include/linux/timex.h

+8 −2

Original line number	Diff line number	Diff line
		@@ -294,11 +294,15 @@ extern void register_time_interpolator(struct time_interpolator *);
		extern void unregister_time_interpolator(struct time_interpolator *);
		extern void time_interpolator_reset(void);
		extern unsigned long time_interpolator_get_offset(void);
		extern void time_interpolator_update(long delta_nsec);

		#else /* !CONFIG_TIME_INTERPOLATION */

		static inline void
		time_interpolator_reset(void)
		static inline void time_interpolator_reset(void)
		{
		}

		static inline void time_interpolator_update(long delta_nsec)
		{
		}

		@@ -309,6 +313,8 @@ time_interpolator_reset(void)
		/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
		extern u64 current_tick_length(void);

		extern void second_overflow(void);
		extern void update_ntp_one_tick(void);
		extern int do_adjtimex(struct timex *);

		#endif /* KERNEL */

kernel/time.c

+0 −173

Original line number	Diff line number	Diff line
		@@ -202,179 +202,6 @@ asmlinkage long sys_settimeofday(struct timeval __user *tv,
		return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
		}

		/* we call this to notify the arch when the clock is being
		* controlled. If no such arch routine, do nothing.
		*/
		void __attribute__ ((weak)) notify_arch_cmos_timer(void)
		{
		return;
		}

		/* adjtimex mainly allows reading (and writing, if superuser) of
		* kernel time-keeping variables. used by xntpd.
		*/
		int do_adjtimex(struct timex *txc)
		{
		long ltemp, mtemp, save_adjust;
		int result;

		/* In order to modify anything, you gotta be super-user! */
		if (txc->modes && !capable(CAP_SYS_TIME))
		return -EPERM;

		/* Now we validate the data before disabling interrupts */

		if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
		/* singleshot must not be used with any other mode bits */
		if (txc->modes != ADJ_OFFSET_SINGLESHOT)
		return -EINVAL;

		if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
		/* adjustment Offset limited to +- .512 seconds */
		if (txc->offset <= - MAXPHASE \|\| txc->offset >= MAXPHASE )
		return -EINVAL;

		/* if the quartz is off by more than 10% something is VERY wrong ! */
		if (txc->modes & ADJ_TICK)
		if (txc->tick < 900000/USER_HZ \|\|
		txc->tick > 1100000/USER_HZ)
		return -EINVAL;

		write_seqlock_irq(&xtime_lock);
		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;

		#if 0 /* STA_CLOCKERR is never set yet */
		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;
		}
		time_freq = txc->freq;
		}

		if (txc->modes & ADJ_MAXERROR) {
		if (txc->maxerror < 0 \|\| txc->maxerror >= NTP_PHASE_LIMIT) {
		result = -EINVAL;
		goto leave;
		}
		time_maxerror = txc->maxerror;
		}

		if (txc->modes & ADJ_ESTERROR) {
		if (txc->esterror < 0 \|\| txc->esterror >= NTP_PHASE_LIMIT) {
		result = -EINVAL;
		goto leave;
		}
		time_esterror = txc->esterror;
		}

		if (txc->modes & ADJ_TIMECONST) { /* p. 24 */
		if (txc->constant < 0) { /* NTP v4 uses values > 6 */
		result = -EINVAL;
		goto leave;
		}
		time_constant = txc->constant;
		}

		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;
		}
		else if (time_status & STA_PLL) {
		ltemp = txc->offset;

		/*
		* Scale the phase adjustment and
		* clamp to the operating range.
		*/
		if (ltemp > MAXPHASE)
		time_offset = MAXPHASE << SHIFT_UPDATE;
		else if (ltemp < -MAXPHASE)
		time_offset = -(MAXPHASE << SHIFT_UPDATE);
		else
		time_offset = ltemp << SHIFT_UPDATE;

		/*
		* 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;
		if (time_status & STA_FLL) {
		if (mtemp >= MINSEC) {
		ltemp = (time_offset / mtemp) << (SHIFT_USEC -
		SHIFT_UPDATE);
		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;
		}
		time_freq = min(time_freq, time_tolerance);
		time_freq = max(time_freq, -time_tolerance);
		} /* STA_PLL */
		} /* txc->modes & ADJ_OFFSET */
		if (txc->modes & ADJ_TICK) {
		tick_usec = txc->tick;
		tick_nsec = TICK_USEC_TO_NSEC(tick_usec);
		}
		} /* txc->modes */
		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;
		else {
		txc->offset = shift_right(time_offset, SHIFT_UPDATE);
		}
		txc->freq = time_freq;
		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->tick = tick_usec;

		/* PPS is not implemented, so these are zero */
		txc->ppsfreq = 0;
		txc->jitter = 0;
		txc->shift = 0;
		txc->stabil = 0;
		txc->jitcnt = 0;
		txc->calcnt = 0;
		txc->errcnt = 0;
		txc->stbcnt = 0;
		write_sequnlock_irq(&xtime_lock);
		do_gettimeofday(&txc->time);
		notify_arch_cmos_timer();
		return(result);
		}

		asmlinkage long sys_adjtimex(struct timex __user *txc_p)
		{
		struct timex txc; /* Local copy of parameter */

kernel/time/Makefile

+1 −1

Original line number	Diff line number	Diff line
		obj-y += clocksource.o jiffies.o
		obj-y += ntp.o clocksource.o jiffies.o

kernel/time/ntp.c

0 → 100644

+389 −0

Original line number	Diff line number	Diff line
		/*
		* linux/kernel/time/ntp.c
		*
		* NTP state machine interfaces and logic.
		*
		* This code was mainly moved from kernel/timer.c and kernel/time.c
		* Please see those files for relevant copyright info and historical
		* changelogs.
		*/

		#include <linux/mm.h>
		#include <linux/time.h>
		#include <linux/timex.h>

		#include <asm/div64.h>
		#include <asm/timex.h>

		/* Don't completely fail for HZ > 500. */
		int tickadj = 500/HZ ? : 1; /* microsecs */

		/*
		* phase-lock loop variables
		*/
		/* TIME_ERROR prevents overwriting the CMOS clock */
		int time_state = TIME_OK; /* clock synchronization status */
		int time_status = STA_UNSYNC; /* clock status bits */
		long time_offset; /* time adjustment (us) */
		long time_constant = 2; /* pll time constant */
		long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */
		long time_precision = 1; /* clock precision (us) */
		long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
		long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
		long time_freq = (((NSEC_PER_SEC + HZ/2) % HZ - HZ/2) << SHIFT_USEC) / NSEC_PER_USEC;
		/* frequency offset (scaled ppm)*/
		static long time_adj; /* tick adjust (scaled 1 / HZ) */
		long time_reftime; /* time at last adjustment (s) */
		long time_adjust;
		long time_next_adjust;

		/*
		* this routine handles the overflow of the microsecond field
		*
		* The tricky bits of code to handle the accurate clock support
		* were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
		* They were originally developed for SUN and DEC kernels.
		* All the kudos should go to Dave for this stuff.
		*/
		void second_overflow(void)
		{
		long ltemp;

		/* Bump the maxerror field */
		time_maxerror += time_tolerance >> SHIFT_USEC;
		if (time_maxerror > NTP_PHASE_LIMIT) {
		time_maxerror = NTP_PHASE_LIMIT;
		time_status \|= STA_UNSYNC;
		}

		/*
		* Leap second processing. If in leap-insert state at the end of the
		* day, the system clock is set back one second; if in leap-delete
		* state, the system clock is set ahead one second. The microtime()
		* routine or external clock driver will insure that reported time is
		* always monotonic. The ugly divides should be replaced.
		*/
		switch (time_state) {
		case TIME_OK:
		if (time_status & STA_INS)
		time_state = TIME_INS;
		else if (time_status & STA_DEL)
		time_state = TIME_DEL;
		break;
		case TIME_INS:
		if (xtime.tv_sec % 86400 == 0) {
		xtime.tv_sec--;
		wall_to_monotonic.tv_sec++;
		/*
		* The timer interpolator will make time change
		* gradually instead of an immediate jump by one second
		*/
		time_interpolator_update(-NSEC_PER_SEC);
		time_state = TIME_OOP;
		clock_was_set();
		printk(KERN_NOTICE "Clock: inserting leap second "
		"23:59:60 UTC\n");
		}
		break;
		case TIME_DEL:
		if ((xtime.tv_sec + 1) % 86400 == 0) {
		xtime.tv_sec++;
		wall_to_monotonic.tv_sec--;
		/*
		* Use of time interpolator for a gradual change of
		* time
		*/
		time_interpolator_update(NSEC_PER_SEC);
		time_state = TIME_WAIT;
		clock_was_set();
		printk(KERN_NOTICE "Clock: deleting leap second "
		"23:59:59 UTC\n");
		}
		break;
		case TIME_OOP:
		time_state = TIME_WAIT;
		break;
		case TIME_WAIT:
		if (!(time_status & (STA_INS \| STA_DEL)))
		time_state = TIME_OK;
		}

		/*
		* 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.
		*/
		ltemp = time_offset;
		if (!(time_status & STA_FLL))
		ltemp = shift_right(ltemp, SHIFT_KG + time_constant);
		ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
		ltemp = max(ltemp, -(MAXPHASE / MINSEC) << SHIFT_UPDATE);
		time_offset -= ltemp;
		time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);

		/*
		* Compute the frequency estimate and additional phase adjustment due
		* to frequency error for the next second.
		*/
		ltemp = time_freq;
		time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE));

		#if HZ == 100
		/*
		* Compensate for (HZ==100) != (1 << SHIFT_HZ). Add 25% and 3.125% to
		* get 128.125; => only 0.125% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5);
		#endif
		#if HZ == 250
		/*
		* Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and
		* 0.78125% to get 255.85938; => only 0.05% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
		#endif
		#if HZ == 1000
		/*
		* Compensate for (HZ==1000) != (1 << SHIFT_HZ). Add 1.5625% and
		* 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
		#endif
		}

		/*
		* 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;
		}
		}

		/*
		* Return how long ticks are at the moment, that is, how much time
		* update_wall_time_one_tick will add to xtime next time we call it
		* (assuming no calls to do_adjtimex in the meantime).
		* The return value is in fixed-point nanoseconds shifted by the
		* specified number of bits to the right of the binary point.
		* This function has no side-effects.
		*/
		u64 current_tick_length(void)
		{
		long delta_nsec;
		u64 ret;

		/* calculate the finest interval NTP will allow.
		* ie: nanosecond value shifted by (SHIFT_SCALE - 10)
		*/
		delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
		ret = (u64)delta_nsec << TICK_LENGTH_SHIFT;
		ret += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10));

		return ret;
		}


		void __attribute__ ((weak)) notify_arch_cmos_timer(void)
		{
		return;
		}

		/* adjtimex mainly allows reading (and writing, if superuser) of
		* kernel time-keeping variables. used by xntpd.
		*/
		int do_adjtimex(struct timex *txc)
		{
		long ltemp, mtemp, save_adjust;
		int result;

		/* In order to modify anything, you gotta be super-user! */
		if (txc->modes && !capable(CAP_SYS_TIME))
		return -EPERM;

		/* Now we validate the data before disabling interrupts */

		if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
		/* singleshot must not be used with any other mode bits */
		if (txc->modes != ADJ_OFFSET_SINGLESHOT)
		return -EINVAL;

		if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
		/* adjustment Offset limited to +- .512 seconds */
		if (txc->offset <= - MAXPHASE \|\| txc->offset >= MAXPHASE )
		return -EINVAL;

		/* if the quartz is off by more than 10% something is VERY wrong ! */
		if (txc->modes & ADJ_TICK)
		if (txc->tick < 900000/USER_HZ \|\|
		txc->tick > 1100000/USER_HZ)
		return -EINVAL;

		write_seqlock_irq(&xtime_lock);
		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;

		#if 0 /* STA_CLOCKERR is never set yet */
		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;
		}
		time_freq = txc->freq;
		}

		if (txc->modes & ADJ_MAXERROR) {
		if (txc->maxerror < 0 \|\| txc->maxerror >= NTP_PHASE_LIMIT) {
		result = -EINVAL;
		goto leave;
		}
		time_maxerror = txc->maxerror;
		}

		if (txc->modes & ADJ_ESTERROR) {
		if (txc->esterror < 0 \|\| txc->esterror >= NTP_PHASE_LIMIT) {
		result = -EINVAL;
		goto leave;
		}
		time_esterror = txc->esterror;
		}

		if (txc->modes & ADJ_TIMECONST) { /* p. 24 */
		if (txc->constant < 0) { /* NTP v4 uses values > 6 */
		result = -EINVAL;
		goto leave;
		}
		time_constant = txc->constant;
		}

		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;
		}
		else if (time_status & STA_PLL) {
		ltemp = txc->offset;

		/*
		* Scale the phase adjustment and
		* clamp to the operating range.
		*/
		if (ltemp > MAXPHASE)
		time_offset = MAXPHASE << SHIFT_UPDATE;
		else if (ltemp < -MAXPHASE)
		time_offset = -(MAXPHASE << SHIFT_UPDATE);
		else
		time_offset = ltemp << SHIFT_UPDATE;

		/*
		* 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;
		if (time_status & STA_FLL) {
		if (mtemp >= MINSEC) {
		ltemp = (time_offset / mtemp) << (SHIFT_USEC -
		SHIFT_UPDATE);
		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;
		}
		time_freq = min(time_freq, time_tolerance);
		time_freq = max(time_freq, -time_tolerance);
		} /* STA_PLL */
		} /* txc->modes & ADJ_OFFSET */
		if (txc->modes & ADJ_TICK) {
		tick_usec = txc->tick;
		tick_nsec = TICK_USEC_TO_NSEC(tick_usec);
		}
		} /* txc->modes */
		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;
		else {
		txc->offset = shift_right(time_offset, SHIFT_UPDATE);
		}
		txc->freq = time_freq;
		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->tick = tick_usec;

		/* PPS is not implemented, so these are zero */
		txc->ppsfreq = 0;
		txc->jitter = 0;
		txc->shift = 0;
		txc->stabil = 0;
		txc->jitcnt = 0;
		txc->calcnt = 0;
		txc->errcnt = 0;
		txc->stbcnt = 0;
		write_sequnlock_irq(&xtime_lock);
		do_gettimeofday(&txc->time);
		notify_arch_cmos_timer();
		return(result);
		}

kernel/timer.c

+1 −210

Original line number	Diff line number	Diff line
		@@ -41,12 +41,6 @@
		#include <asm/timex.h>
		#include <asm/io.h>

		#ifdef CONFIG_TIME_INTERPOLATION
		static void time_interpolator_update(long delta_nsec);
		#else
		#define time_interpolator_update(x)
		#endif

		u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;

		EXPORT_SYMBOL(jiffies_64);
		@@ -587,209 +581,6 @@ struct timespec wall_to_monotonic __attribute__ ((aligned (16)));

		EXPORT_SYMBOL(xtime);

		/* Don't completely fail for HZ > 500. */
		int tickadj = 500/HZ ? : 1; /* microsecs */


		/*
		* phase-lock loop variables
		*/
		/* TIME_ERROR prevents overwriting the CMOS clock */
		int time_state = TIME_OK; /* clock synchronization status */
		int time_status = STA_UNSYNC; /* clock status bits */
		long time_offset; /* time adjustment (us) */
		long time_constant = 2; /* pll time constant */
		long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */
		long time_precision = 1; /* clock precision (us) */
		long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
		long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
		long time_freq = (((NSEC_PER_SEC + HZ/2) % HZ - HZ/2) << SHIFT_USEC) / NSEC_PER_USEC;
		/* frequency offset (scaled ppm)*/
		static long time_adj; /* tick adjust (scaled 1 / HZ) */
		long time_reftime; /* time at last adjustment (s) */
		long time_adjust;
		long time_next_adjust;

		/*
		* this routine handles the overflow of the microsecond field
		*
		* The tricky bits of code to handle the accurate clock support
		* were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
		* They were originally developed for SUN and DEC kernels.
		* All the kudos should go to Dave for this stuff.
		*
		*/
		static void second_overflow(void)
		{
		long ltemp;

		/* Bump the maxerror field */
		time_maxerror += time_tolerance >> SHIFT_USEC;
		if (time_maxerror > NTP_PHASE_LIMIT) {
		time_maxerror = NTP_PHASE_LIMIT;
		time_status \|= STA_UNSYNC;
		}

		/*
		* Leap second processing. If in leap-insert state at the end of the
		* day, the system clock is set back one second; if in leap-delete
		* state, the system clock is set ahead one second. The microtime()
		* routine or external clock driver will insure that reported time is
		* always monotonic. The ugly divides should be replaced.
		*/
		switch (time_state) {
		case TIME_OK:
		if (time_status & STA_INS)
		time_state = TIME_INS;
		else if (time_status & STA_DEL)
		time_state = TIME_DEL;
		break;
		case TIME_INS:
		if (xtime.tv_sec % 86400 == 0) {
		xtime.tv_sec--;
		wall_to_monotonic.tv_sec++;
		/*
		* The timer interpolator will make time change
		* gradually instead of an immediate jump by one second
		*/
		time_interpolator_update(-NSEC_PER_SEC);
		time_state = TIME_OOP;
		clock_was_set();
		printk(KERN_NOTICE "Clock: inserting leap second "
		"23:59:60 UTC\n");
		}
		break;
		case TIME_DEL:
		if ((xtime.tv_sec + 1) % 86400 == 0) {
		xtime.tv_sec++;
		wall_to_monotonic.tv_sec--;
		/*
		* Use of time interpolator for a gradual change of
		* time
		*/
		time_interpolator_update(NSEC_PER_SEC);
		time_state = TIME_WAIT;
		clock_was_set();
		printk(KERN_NOTICE "Clock: deleting leap second "
		"23:59:59 UTC\n");
		}
		break;
		case TIME_OOP:
		time_state = TIME_WAIT;
		break;
		case TIME_WAIT:
		if (!(time_status & (STA_INS \| STA_DEL)))
		time_state = TIME_OK;
		}

		/*
		* 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.
		*/
		ltemp = time_offset;
		if (!(time_status & STA_FLL))
		ltemp = shift_right(ltemp, SHIFT_KG + time_constant);
		ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
		ltemp = max(ltemp, -(MAXPHASE / MINSEC) << SHIFT_UPDATE);
		time_offset -= ltemp;
		time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);

		/*
		* Compute the frequency estimate and additional phase adjustment due
		* to frequency error for the next second.
		*/
		ltemp = time_freq;
		time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE));

		#if HZ == 100
		/*
		* Compensate for (HZ==100) != (1 << SHIFT_HZ). Add 25% and 3.125% to
		* get 128.125; => only 0.125% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5);
		#endif
		#if HZ == 250
		/*
		* Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and
		* 0.78125% to get 255.85938; => only 0.05% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
		#endif
		#if HZ == 1000
		/*
		* Compensate for (HZ==1000) != (1 << SHIFT_HZ). Add 1.5625% and
		* 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
		*/
		time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
		#endif
		}

		/*
		* 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()" */
		static 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;
		}
		}

		/*
		* Return how long ticks are at the moment, that is, how much time
		* update_wall_time_one_tick will add to xtime next time we call it
		* (assuming no calls to do_adjtimex in the meantime).
		* The return value is in fixed-point nanoseconds shifted by the
		* specified number of bits to the right of the binary point.
		* This function has no side-effects.
		*/
		u64 current_tick_length(void)
		{
		long delta_nsec;
		u64 ret;

		/* calculate the finest interval NTP will allow.
		* ie: nanosecond value shifted by (SHIFT_SCALE - 10)
		*/
		delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
		ret = (u64)delta_nsec << TICK_LENGTH_SHIFT;
		ret += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10));

		return ret;
		}

		/* XXX - all of this timekeeping code should be later moved to time.c */
		#include <linux/clocksource.h>
		@@ -1775,7 +1566,7 @@ unsigned long time_interpolator_get_offset(void)
		#define INTERPOLATOR_ADJUST 65536
		#define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST

		static void time_interpolator_update(long delta_nsec)
		void time_interpolator_update(long delta_nsec)
		{
		u64 counter;
		unsigned long offset;