[deliverable/linux.git] / kernel / time / ntp.c

/*
 * 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>

/*
 * Timekeeping variables
 */
unsigned long tick_usec = TICK_USEC; 		/* USER_HZ period (usec) */
unsigned long tick_nsec;			/* ACTHZ period (nsec) */
static u64 tick_length, tick_length_base;

#define MAX_TICKADJ		500		/* microsecs */
#define MAX_TICKADJ_SCALED	(((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
				  TICK_LENGTH_SHIFT) / HZ)

/*
 * 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 (ns)		*/
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;				/* frequency offset (scaled ppm)*/
long time_reftime;			/* time at last adjustment (s)	*/
long time_adjust;

/**
 * ntp_clear - Clears the NTP state variables
 *
 * Must be called while holding a write on the xtime_lock
 */
void ntp_clear(void)
{
	time_adjust = 0;		/* stop active adjtime() */
	time_status |= STA_UNSYNC;
	time_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;

	ntp_update_frequency();

	tick_length = tick_length_base;
	time_offset = 0;
}

#define CLOCK_TICK_OVERFLOW	(LATCH * HZ - CLOCK_TICK_RATE)
#define CLOCK_TICK_ADJUST	(((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / (s64)CLOCK_TICK_RATE)

void ntp_update_frequency(void)
{
	tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT;
	tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
	tick_length_base += ((s64)time_freq * NSEC_PER_USEC) << (TICK_LENGTH_SHIFT - SHIFT_USEC);

	do_div(tick_length_base, HZ);

	tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT;
}

/*
 * 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 time_adj;

	/* 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.
	 */
	tick_length = tick_length_base;
	time_adj = time_offset;
	if (!(time_status & STA_FLL))
		time_adj = shift_right(time_adj, SHIFT_KG + time_constant);
	time_adj = min(time_adj, -((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
	time_adj = max(time_adj, ((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
	time_offset -= time_adj;
	tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);

	if (unlikely(time_adjust)) {
		if (time_adjust > MAX_TICKADJ) {
			time_adjust -= MAX_TICKADJ;
			tick_length += MAX_TICKADJ_SCALED;
		} else if (time_adjust < -MAX_TICKADJ) {
			time_adjust += MAX_TICKADJ;
			tick_length -= MAX_TICKADJ_SCALED;
		} else {
			time_adjust = 0;
			tick_length += (s64)(time_adjust * NSEC_PER_USEC /
					     HZ) << TICK_LENGTH_SHIFT;
		}
	}
}

/*
 * 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)
{
	return tick_length;
}


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

		    /*
		     * Scale the phase adjustment and
		     * clamp to the operating range.
		     */
		    time_offset = min(ltemp, MAXPHASE);
		    time_offset = max(time_offset, -MAXPHASE);

		    /*
		     * 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 << 12) / mtemp) << (SHIFT_USEC - 12);
			    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);
		    time_offset = (time_offset * NSEC_PER_USEC / HZ) << 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)
		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) * HZ / 1000;
	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);
}
Commit	Line	Data
4c7ee8de	1	/*
	2	* linux/kernel/time/ntp.c
	3	*
	4	* NTP state machine interfaces and logic.
	5	*
	6	* This code was mainly moved from kernel/timer.c and kernel/time.c
	7	* Please see those files for relevant copyright info and historical
	8	* changelogs.
	9	*/
	10
	11	#include <linux/mm.h>
	12	#include <linux/time.h>
	13	#include <linux/timex.h>
	14
	15	#include <asm/div64.h>
	16	#include <asm/timex.h>
	17
b0ee7556 RZ	18	/*
	19	* Timekeeping variables
	20	*/
	21	unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
	22	unsigned long tick_nsec; /* ACTHZ period (nsec) */
	23	static u64 tick_length, tick_length_base;
	24
8f807f8d RZ	25	#define MAX_TICKADJ 500 /* microsecs */
	26	#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
	27	TICK_LENGTH_SHIFT) / HZ)
4c7ee8de	28
	29	/*
	30	* phase-lock loop variables
	31	*/
	32	/* TIME_ERROR prevents overwriting the CMOS clock */
	33	int time_state = TIME_OK; /* clock synchronization status */
	34	int time_status = STA_UNSYNC; /* clock status bits */
3d3675cc	35	long time_offset; /* time adjustment (ns) */
4c7ee8de	36	long time_constant = 2; /* pll time constant */
	37	long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */
	38	long time_precision = 1; /* clock precision (us) */
	39	long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
	40	long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
dc6a43e4	41	long time_freq; /* frequency offset (scaled ppm)*/
4c7ee8de	42	long time_reftime; /* time at last adjustment (s) */
4c7ee8de	43	long time_adjust;
4c7ee8de	44
b0ee7556 RZ	45	/**
	46	* ntp_clear - Clears the NTP state variables
	47	*
	48	* Must be called while holding a write on the xtime_lock
	49	*/
	50	void ntp_clear(void)
	51	{
	52	time_adjust = 0; /* stop active adjtime() */
	53	time_status \|= STA_UNSYNC;
	54	time_maxerror = NTP_PHASE_LIMIT;
	55	time_esterror = NTP_PHASE_LIMIT;
	56
	57	ntp_update_frequency();
	58
	59	tick_length = tick_length_base;
3d3675cc	60	time_offset = 0;
b0ee7556 RZ	61	}
	62
	63	#define CLOCK_TICK_OVERFLOW (LATCH * HZ - CLOCK_TICK_RATE)
	64	#define CLOCK_TICK_ADJUST (((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / (s64)CLOCK_TICK_RATE)
	65
	66	void ntp_update_frequency(void)
	67	{
	68	tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT;
	69	tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
dc6a43e4	70	tick_length_base += ((s64)time_freq * NSEC_PER_USEC) << (TICK_LENGTH_SHIFT - SHIFT_USEC);
b0ee7556 RZ	71
	72	do_div(tick_length_base, HZ);
	73
	74	tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT;
	75	}
	76
4c7ee8de	77	/*
	78	* this routine handles the overflow of the microsecond field
	79	*
	80	* The tricky bits of code to handle the accurate clock support
	81	* were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
	82	* They were originally developed for SUN and DEC kernels.
	83	* All the kudos should go to Dave for this stuff.
	84	*/
	85	void second_overflow(void)
	86	{
3d3675cc	87	long time_adj;
4c7ee8de	88
	89	/* Bump the maxerror field */
	90	time_maxerror += time_tolerance >> SHIFT_USEC;
	91	if (time_maxerror > NTP_PHASE_LIMIT) {
	92	time_maxerror = NTP_PHASE_LIMIT;
	93	time_status \|= STA_UNSYNC;
	94	}
	95
	96	/*
	97	* Leap second processing. If in leap-insert state at the end of the
	98	* day, the system clock is set back one second; if in leap-delete
	99	* state, the system clock is set ahead one second. The microtime()
	100	* routine or external clock driver will insure that reported time is
	101	* always monotonic. The ugly divides should be replaced.
	102	*/
	103	switch (time_state) {
	104	case TIME_OK:
	105	if (time_status & STA_INS)
	106	time_state = TIME_INS;
	107	else if (time_status & STA_DEL)
	108	time_state = TIME_DEL;
	109	break;
	110	case TIME_INS:
	111	if (xtime.tv_sec % 86400 == 0) {
	112	xtime.tv_sec--;
	113	wall_to_monotonic.tv_sec++;
	114	/*
	115	* The timer interpolator will make time change
	116	* gradually instead of an immediate jump by one second
	117	*/
	118	time_interpolator_update(-NSEC_PER_SEC);
	119	time_state = TIME_OOP;
	120	clock_was_set();
	121	printk(KERN_NOTICE "Clock: inserting leap second "
	122	"23:59:60 UTC\n");
	123	}
	124	break;
	125	case TIME_DEL:
	126	if ((xtime.tv_sec + 1) % 86400 == 0) {
	127	xtime.tv_sec++;
	128	wall_to_monotonic.tv_sec--;
	129	/*
	130	* Use of time interpolator for a gradual change of
	131	* time
	132	*/
	133	time_interpolator_update(NSEC_PER_SEC);
	134	time_state = TIME_WAIT;
	135	clock_was_set();
	136	printk(KERN_NOTICE "Clock: deleting leap second "
	137	"23:59:59 UTC\n");
	138	}
	139	break;
	140	case TIME_OOP:
	141	time_state = TIME_WAIT;
	142	break;
	143	case TIME_WAIT:
	144	if (!(time_status & (STA_INS \| STA_DEL)))
	145	time_state = TIME_OK;
	146	}
	147
	148	/*
	149	* Compute the phase adjustment for the next second. In PLL mode, the
	150	* offset is reduced by a fixed factor times the time constant. In FLL
	151	* mode the offset is used directly. In either mode, the maximum phase
152	* adjustment for each second is clamped so as to spread the adjustment
153	* over not more than the number of seconds between updates.
154	*/
b0ee7556	155	tick_length = tick_length_base;
3d3675cc RZ	156	time_adj = time_offset;
	157	if (!(time_status & STA_FLL))
	158	time_adj = shift_right(time_adj, SHIFT_KG + time_constant);
	159	time_adj = min(time_adj, -((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
	160	time_adj = max(time_adj, ((MAXPHASE / HZ) << SHIFT_UPDATE) / MINSEC);
	161	time_offset -= time_adj;
	162	tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);
4c7ee8de	163
8f807f8d RZ	164	if (unlikely(time_adjust)) {
	165	if (time_adjust > MAX_TICKADJ) {
	166	time_adjust -= MAX_TICKADJ;
	167	tick_length += MAX_TICKADJ_SCALED;
	168	} else if (time_adjust < -MAX_TICKADJ) {
	169	time_adjust += MAX_TICKADJ;
	170	tick_length -= MAX_TICKADJ_SCALED;
	171	} else {
	172	time_adjust = 0;
	173	tick_length += (s64)(time_adjust * NSEC_PER_USEC /
	174	HZ) << TICK_LENGTH_SHIFT;
	175	}
4c7ee8de	176	}
	177	}
	178
	179	/*
	180	* Return how long ticks are at the moment, that is, how much time
	181	* update_wall_time_one_tick will add to xtime next time we call it
	182	* (assuming no calls to do_adjtimex in the meantime).
	183	* The return value is in fixed-point nanoseconds shifted by the
	184	* specified number of bits to the right of the binary point.
	185	* This function has no side-effects.
	186	*/
	187	u64 current_tick_length(void)
	188	{
8f807f8d	189	return tick_length;
4c7ee8de	190	}
	191
	192
	193	void __attribute__ ((weak)) notify_arch_cmos_timer(void)
	194	{
	195	return;
	196	}
	197
	198	/* adjtimex mainly allows reading (and writing, if superuser) of
	199	* kernel time-keeping variables. used by xntpd.
	200	*/
	201	int do_adjtimex(struct timex *txc)
	202	{
	203	long ltemp, mtemp, save_adjust;
	204	int result;
	205
	206	/* In order to modify anything, you gotta be super-user! */
	207	if (txc->modes && !capable(CAP_SYS_TIME))
	208	return -EPERM;
	209
	210	/* Now we validate the data before disabling interrupts */
	211
	212	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
	213	/* singleshot must not be used with any other mode bits */
	214	if (txc->modes != ADJ_OFFSET_SINGLESHOT)
	215	return -EINVAL;
	216
	217	if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
	218	/* adjustment Offset limited to +- .512 seconds */
	219	if (txc->offset <= - MAXPHASE \|\| txc->offset >= MAXPHASE )
	220	return -EINVAL;
	221
	222	/* if the quartz is off by more than 10% something is VERY wrong ! */
	223	if (txc->modes & ADJ_TICK)
	224	if (txc->tick < 900000/USER_HZ \|\|
	225	txc->tick > 1100000/USER_HZ)
	226	return -EINVAL;
	227
	228	write_seqlock_irq(&xtime_lock);
	229	result = time_state; /* mostly `TIME_OK' */
	230
	231	/* Save for later - semantics of adjtime is to return old value */
8f807f8d	232	save_adjust = time_adjust;
4c7ee8de	233
	234	#if 0 /* STA_CLOCKERR is never set yet */
	235	time_status &= ~STA_CLOCKERR; /* reset STA_CLOCKERR */
	236	#endif
	237	/* If there are input parameters, then process them */
	238	if (txc->modes)
	239	{
	240	if (txc->modes & ADJ_STATUS) /* only set allowed bits */
	241	time_status = (txc->status & ~STA_RONLY) \|
	242	(time_status & STA_RONLY);
	243
	244	if (txc->modes & ADJ_FREQUENCY) { /* p. 22 */
	245	if (txc->freq > MAXFREQ \|\| txc->freq < -MAXFREQ) {
	246	result = -EINVAL;
	247	goto leave;
	248	}
	249	time_freq = txc->freq;
	250	}
	251
	252	if (txc->modes & ADJ_MAXERROR) {
	253	if (txc->maxerror < 0 \|\| txc->maxerror >= NTP_PHASE_LIMIT) {
	254	result = -EINVAL;
	255	goto leave;
	256	}
	257	time_maxerror = txc->maxerror;
	258	}
	259
	260	if (txc->modes & ADJ_ESTERROR) {
	261	if (txc->esterror < 0 \|\| txc->esterror >= NTP_PHASE_LIMIT) {
	262	result = -EINVAL;
	263	goto leave;
	264	}
	265	time_esterror = txc->esterror;
	266	}
	267
	268	if (txc->modes & ADJ_TIMECONST) { /* p. 24 */
	269	if (txc->constant < 0) { /* NTP v4 uses values > 6 */
	270	result = -EINVAL;
	271	goto leave;
	272	}
	273	time_constant = txc->constant;
	274	}
	275
	276	if (txc->modes & ADJ_OFFSET) { /* values checked earlier */
	277	if (txc->modes == ADJ_OFFSET_SINGLESHOT) {
	278	/* adjtime() is independent from ntp_adjtime() */
8f807f8d	279	time_adjust = txc->offset;
4c7ee8de	280	}
	281	else if (time_status & STA_PLL) {
	282	ltemp = txc->offset;
	283
	284	/*
	285	* Scale the phase adjustment and
	286	* clamp to the operating range.
	287	*/
3d3675cc RZ	288	time_offset = min(ltemp, MAXPHASE);
3d3675cc RZ	289	time_offset = max(time_offset, -MAXPHASE);
4c7ee8de	290
	291	/*
	292	* Select whether the frequency is to be controlled
	293	* and in which mode (PLL or FLL). Clamp to the operating
	294	* range. Ugly multiply/divide should be replaced someday.
	295	*/
	296
	297	if (time_status & STA_FREQHOLD \|\| time_reftime == 0)
	298	time_reftime = xtime.tv_sec;
	299	mtemp = xtime.tv_sec - time_reftime;
	300	time_reftime = xtime.tv_sec;
	301	if (time_status & STA_FLL) {
	302	if (mtemp >= MINSEC) {
3d3675cc	303	ltemp = ((time_offset << 12) / mtemp) << (SHIFT_USEC - 12);
4c7ee8de	304	time_freq += shift_right(ltemp, SHIFT_KH);
	305	} else /* calibration interval too short (p. 12) */
	306	result = TIME_ERROR;
	307	} else { /* PLL mode */
	308	if (mtemp < MAXSEC) {
	309	ltemp *= mtemp;
	310	time_freq += shift_right(ltemp,(time_constant +
	311	time_constant +
	312	SHIFT_KF - SHIFT_USEC));
	313	} else /* calibration interval too long (p. 12) */
	314	result = TIME_ERROR;
	315	}
	316	time_freq = min(time_freq, time_tolerance);
	317	time_freq = max(time_freq, -time_tolerance);
3d3675cc	318	time_offset = (time_offset * NSEC_PER_USEC / HZ) << SHIFT_UPDATE;
4c7ee8de	319	} /* STA_PLL */
4c7ee8de	320	} /* txc->modes & ADJ_OFFSET */
b0ee7556	321	if (txc->modes & ADJ_TICK)
4c7ee8de	322	tick_usec = txc->tick;
b0ee7556	323
dc6a43e4	324	if (txc->modes & (ADJ_TICK\|ADJ_FREQUENCY\|ADJ_OFFSET))
b0ee7556	325	ntp_update_frequency();
4c7ee8de	326	} /* txc->modes */
	327	leave: if ((time_status & (STA_UNSYNC\|STA_CLOCKERR)) != 0)
	328	result = TIME_ERROR;
	329
	330	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
	331	txc->offset = save_adjust;
3d3675cc RZ	332	else
3d3675cc RZ	333	txc->offset = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000;
4c7ee8de	334	txc->freq = time_freq;
	335	txc->maxerror = time_maxerror;
	336	txc->esterror = time_esterror;
	337	txc->status = time_status;
	338	txc->constant = time_constant;
	339	txc->precision = time_precision;
	340	txc->tolerance = time_tolerance;
	341	txc->tick = tick_usec;
	342
	343	/* PPS is not implemented, so these are zero */
	344	txc->ppsfreq = 0;
	345	txc->jitter = 0;
	346	txc->shift = 0;
	347	txc->stabil = 0;
	348	txc->jitcnt = 0;
	349	txc->calcnt = 0;
	350	txc->errcnt = 0;
	351	txc->stbcnt = 0;
	352	write_sequnlock_irq(&xtime_lock);
	353	do_gettimeofday(&txc->time);
	354	notify_arch_cmos_timer();
	355	return(result);
	356	}