This adds support for setting the TAI value (International Atomic Time).
The value is reported back to userspace via timex (as we don't have a
ntp_gettime() syscall).
Signed-off-by: Roman Zippel <[email protected]>
---
include/linux/compat.h | 3 ++-
include/linux/timex.h | 4 +++-
kernel/compat.c | 3 ++-
kernel/time/ntp.c | 7 +++++++
4 files changed, 14 insertions(+), 3 deletions(-)
Index: linux-2.6-mm/include/linux/compat.h
===================================================================
--- linux-2.6-mm.orig/include/linux/compat.h
+++ linux-2.6-mm/include/linux/compat.h
@@ -65,10 +65,11 @@ struct compat_timex {
compat_long_t calcnt;
compat_long_t errcnt;
compat_long_t stbcnt;
+ compat_int_t tai;
compat_int_t :32; compat_int_t :32; compat_int_t :32; compat_int_t :32;
compat_int_t :32; compat_int_t :32; compat_int_t :32; compat_int_t :32;
- compat_int_t :32; compat_int_t :32; compat_int_t :32; compat_int_t :32;
+ compat_int_t :32; compat_int_t :32; compat_int_t :32;
};
#define _COMPAT_NSIG_WORDS (_COMPAT_NSIG / _COMPAT_NSIG_BPW)
Index: linux-2.6-mm/include/linux/timex.h
===================================================================
--- linux-2.6-mm.orig/include/linux/timex.h
+++ linux-2.6-mm/include/linux/timex.h
@@ -116,9 +116,11 @@ struct timex {
long errcnt; /* calibration errors (ro) */
long stbcnt; /* stability limit exceeded (ro) */
+ int tai; /* TAI offset (ro) */
+
int :32; int :32; int :32; int :32;
int :32; int :32; int :32; int :32;
- int :32; int :32; int :32; int :32;
+ int :32; int :32; int :32;
};
/*
@@ -135,6 +135,7 @@ struct timex {
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
+#define ADJ_TAI 0x0080 /* set TAI offset */
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
#define ADJ_TICK 0x4000 /* tick value */
Index: linux-2.6-mm/kernel/compat.c
===================================================================
--- linux-2.6-mm.orig/kernel/compat.c
+++ linux-2.6-mm/kernel/compat.c
@@ -955,7 +955,8 @@ asmlinkage long compat_sys_adjtimex(stru
__put_user(txc.jitcnt, &utp->jitcnt) ||
__put_user(txc.calcnt, &utp->calcnt) ||
__put_user(txc.errcnt, &utp->errcnt) ||
- __put_user(txc.stbcnt, &utp->stbcnt))
+ __put_user(txc.stbcnt, &utp->stbcnt) ||
+ __put_user(txc.tai, &utp->tai))
ret = -EFAULT;
return ret;
Index: linux-2.6-mm/kernel/time/ntp.c
===================================================================
--- linux-2.6-mm.orig/kernel/time/ntp.c
+++ linux-2.6-mm/kernel/time/ntp.c
@@ -35,6 +35,7 @@ static u64 tick_length, tick_length_base
/* TIME_ERROR prevents overwriting the CMOS clock */
static int time_state = TIME_OK; /* clock synchronization status */
int time_status = STA_UNSYNC; /* clock status bits */
+static long time_tai; /* TAI offset (s) */
static s64 time_offset; /* time adjustment (ns) */
static long time_constant = 2; /* pll time constant */
long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
@@ -162,6 +163,7 @@ void second_overflow(void)
case TIME_DEL:
if ((xtime.tv_sec + 1) % 86400 == 0) {
xtime.tv_sec++;
+ time_tai--;
wall_to_monotonic.tv_sec--;
time_state = TIME_WAIT;
printk(KERN_NOTICE "Clock: deleting leap second "
@@ -169,6 +171,7 @@ void second_overflow(void)
}
break;
case TIME_OOP:
+ time_tai++;
time_state = TIME_WAIT;
break;
case TIME_WAIT:
@@ -340,6 +343,9 @@ int do_adjtimex(struct timex *txc)
time_constant = max(time_constant, 0l);
}
+ if (txc->modes & ADJ_TAI && txc->constant > 0)
+ time_tai = txc->constant;
+
if (txc->modes & ADJ_OFFSET) {
if (txc->modes == ADJ_OFFSET_SINGLESHOT)
/* adjtime() is independent from ntp_adjtime() */
@@ -375,6 +381,7 @@ int do_adjtimex(struct timex *txc)
txc->precision = 1;
txc->tolerance = MAXFREQ_SCALED / PPM_SCALE;
txc->tick = tick_usec;
+ txc->tai = time_tai;
/* PPS is not implemented, so these are zero */
txc->ppsfreq = 0;
--
On Fri, 2008-03-14 at 19:40 +0100, [email protected] wrote:
> plain text document attachment (time_tai)
> This adds support for setting the TAI value (International Atomic Time).
> The value is reported back to userspace via timex (as we don't have a
> ntp_gettime() syscall).
>
> Signed-off-by: Roman Zippel <[email protected]>
>
Very cool. I just was talking with someone who was looking for a TAI
interface.
Minor nit below.
-john
> Index: linux-2.6-mm/kernel/time/ntp.c
> ===================================================================
> --- linux-2.6-mm.orig/kernel/time/ntp.c
> +++ linux-2.6-mm/kernel/time/ntp.c
> @@ -35,6 +35,7 @@ static u64 tick_length, tick_length_base
> /* TIME_ERROR prevents overwriting the CMOS clock */
> static int time_state = TIME_OK; /* clock synchronization status */
> int time_status = STA_UNSYNC; /* clock status bits */
> +static long time_tai; /* TAI offset (s) */
I think timekeeping.c would be the better place for time_tai, keeping it
closer to xtime and wall_to_monotonic's definitions.
> static s64 time_offset; /* time adjustment (ns) */
> static long time_constant = 2; /* pll time constant */
> long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
> @@ -162,6 +163,7 @@ void second_overflow(void)
> case TIME_DEL:
> if ((xtime.tv_sec + 1) % 86400 == 0) {
> xtime.tv_sec++;
> + time_tai--;
> wall_to_monotonic.tv_sec--;
> time_state = TIME_WAIT;
> printk(KERN_NOTICE "Clock: deleting leap second "
> @@ -169,6 +171,7 @@ void second_overflow(void)
> }
> break;
> case TIME_OOP:
> + time_tai++;
> time_state = TIME_WAIT;
> break;
> case TIME_WAIT:
These manipulations could also be done in the
timekeeping_insert/remove_second interface I suggested earlier.
> @@ -340,6 +343,9 @@ int do_adjtimex(struct timex *txc)
> time_constant = max(time_constant, 0l);
> }
>
> + if (txc->modes & ADJ_TAI && txc->constant > 0)
> + time_tai = txc->constant;
> +
> if (txc->modes & ADJ_OFFSET) {
> if (txc->modes == ADJ_OFFSET_SINGLESHOT)
> /* adjtime() is independent from ntp_adjtime() */
> @@ -375,6 +381,7 @@ int do_adjtimex(struct timex *txc)
> txc->precision = 1;
> txc->tolerance = MAXFREQ_SCALED / PPM_SCALE;
> txc->tick = tick_usec;
> + txc->tai = time_tai;
>
> /* PPS is not implemented, so these are zero */
> txc->ppsfreq = 0;
>