[PATCH 2/8] NTP4 user space bits update

From: zippel
Date: Fri Mar 14 2008 - 16:03:00 EST


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@xxxxxxxxxxxxxx>

---
include/linux/timex.h | 12 ++++--
kernel/time/ntp.c | 91 +++++++++++++++++++++++++-------------------------
2 files changed, 56 insertions(+), 47 deletions(-)

Index: linux-2.6/include/linux/timex.h
===================================================================
--- linux-2.6.orig/include/linux/timex.h 2008-03-13 10:42:20.000000000 +0100
+++ linux-2.6/include/linux/timex.h 2008-03-13 10:48:59.000000000 +0100
@@ -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
@@ -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 */
@@ -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 */


/*
@@ -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)
Index: linux-2.6/kernel/time/ntp.c
===================================================================
--- linux-2.6.orig/kernel/time/ntp.c 2008-03-13 10:42:20.000000000 +0100
+++ linux-2.6/kernel/time/ntp.c 2008-03-13 10:47:49.000000000 +0100
@@ -65,7 +65,9 @@ static void ntp_update_offset(long offse
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
@@ -86,8 +88,11 @@ static void ntp_update_offset(long offse
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);
@@ -272,6 +277,7 @@ static inline void notify_cmos_timer(voi
*/
int do_adjtimex(struct timex *txc)
{
+ struct timespec ts;
long save_adjust;
int result;

@@ -282,17 +288,11 @@ 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 ||
@@ -300,51 +300,46 @@ int do_adjtimex(struct timex *txc)
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) {
@@ -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;
@@ -391,7 +390,11 @@ leave:
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();


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