Skip to content

Commit

Permalink
ntp: NTP4 user space bits update
Browse files Browse the repository at this point in the history 
This adds a few more things from the ntp nanokernel related to user space.
It's now possible to select the resolution used of some values via STA_NANO
and the kernel reports in which mode it works (pll/fll).

If some values for adjtimex() are outside the acceptable range, they are now
simply normalized instead of letting the syscall fail.  I removed
MOD_CLKA/MOD_CLKB as the mapping didn't really makes any sense, the kernel
doesn't support setting the clock.

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>
  • Loading branch information
@torvalds
Roman Zippel authored and torvalds committed May 1, 2008
1 parent ee9851b commit eea83d8
Show file tree
Hide file tree
Showing 2 changed files with 56 additions and 47 deletions.
12 changes: 9 additions & 3 deletions include/linux/timex.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,8 @@

#include <asm/param.h>

#define NTP_API 4 /* NTP API version */

/*
* SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
* for a slightly underdamped convergence characteristic. SHIFT_KH
Expand Down Expand Up @@ -135,6 +137,8 @@ struct timex {
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
#define ADJ_TICK 0x4000 /* tick value */
#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
Expand All @@ -146,8 +150,6 @@ struct timex {
#define MOD_ESTERROR ADJ_ESTERROR
#define MOD_STATUS ADJ_STATUS
#define MOD_TIMECONST ADJ_TIMECONST
#define MOD_CLKB ADJ_TICK
#define MOD_CLKA ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */


/*
Expand All @@ -169,9 +171,13 @@ struct timex {
#define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */

#define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
#define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */
#define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
#define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */

/* read-only bits */
#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
STA_PPSERROR | STA_CLOCKERR) /* read-only bits */
STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)

/*
* Clock states (time_state)
Expand Down
91 changes: 47 additions & 44 deletions kernel/time/ntp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,9 @@ static void ntp_update_offset(long offset)
if (!(time_status & STA_PLL))
return;

time_offset = offset * NSEC_PER_USEC;
time_offset = offset;
if (!(time_status & STA_NANO))
time_offset *= NSEC_PER_USEC;

/*
* Scale the phase adjustment and
Expand All @@ -86,8 +88,11 @@ static void ntp_update_offset(long offset)
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))
time_status &= ~STA_MODE;
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
freq_adj += div_s64(time_offset << (SHIFT_NSEC - SHIFT_FLL), mtemp);
time_status |= STA_MODE;
}
freq_adj += time_freq;
freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
Expand Down Expand Up @@ -272,6 +277,7 @@ static inline void notify_cmos_timer(void) { }
*/
int do_adjtimex(struct timex *txc)
{
struct timespec ts;
long save_adjust;
int result;

Expand All @@ -282,69 +288,58 @@ int do_adjtimex(struct timex *txc)
/* 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 &&
txc->modes != ADJ_OFFSET_SS_READ)
/* singleshot must not be used with any other mode bits */
if (txc->modes & ~ADJ_OFFSET_SS_READ)
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_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;
time_status |= txc->status & ~STA_RONLY;
}

if (txc->modes & ADJ_NANO)
time_status |= STA_NANO;
if (txc->modes & ADJ_MICRO)
time_status &= ~STA_NANO;

if (txc->modes & ADJ_FREQUENCY) {
if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) {
result = -EINVAL;
goto leave;
}
time_freq = ((s64)txc->freq * NSEC_PER_USEC)
time_freq = min(txc->freq, MAXFREQ);
time_freq = min(time_freq, -MAXFREQ);
time_freq = ((s64)time_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)
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)
time_esterror = txc->esterror;
}

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 = 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_OFFSET) {
Expand All @@ -360,16 +355,20 @@ int do_adjtimex(struct timex *txc)
if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
ntp_update_frequency();
}
leave:

result = time_state; /* mostly `TIME_OK' */
if (time_status & (STA_UNSYNC|STA_CLOCKERR))
result = TIME_ERROR;

if ((txc->modes == ADJ_OFFSET_SINGLESHOT) ||
(txc->modes == ADJ_OFFSET_SS_READ))
txc->offset = save_adjust;
else
else {
txc->offset = ((long)shift_right(time_offset, SHIFT_UPDATE)) *
NTP_INTERVAL_FREQ / 1000;
NTP_INTERVAL_FREQ;
if (!(time_status & STA_NANO))
txc->offset /= NSEC_PER_USEC;
}
txc->freq = (time_freq / NSEC_PER_USEC) <<
(SHIFT_USEC - SHIFT_NSEC);
txc->maxerror = time_maxerror;
Expand All @@ -391,7 +390,11 @@ int do_adjtimex(struct timex *txc)
txc->stbcnt = 0;
write_sequnlock_irq(&xtime_lock);

do_gettimeofday(&txc->time);
getnstimeofday(&ts);
txc->time.tv_sec = ts.tv_sec;
txc->time.tv_usec = ts.tv_nsec;
if (!(time_status & STA_NANO))
txc->time.tv_usec /= NSEC_PER_USEC;

notify_cmos_timer();

Expand Down

0 comments on commit eea83d8

Please sign in to comment.