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authorRichard Cochran <richardcochran@gmail.com>2011-02-01 16:52:20 +0300
committerThomas Gleixner <tglx@linutronix.de>2011-02-02 17:28:18 +0300
commit094aa1881fdc1b8889b442eb3511b31f3ec2b762 (patch)
tree2eec808286e2f57eff45178741ba3ea048de7c37
parentc528f7c6c208f1fae6b4025957173dec045e5f21 (diff)
downloadlinux-094aa1881fdc1b8889b442eb3511b31f3ec2b762.tar.xz
ntp: Add ADJ_SETOFFSET mode bit
This patch adds a new mode bit into the timex structure. When set, the bit instructs the kernel to add the given time value to the current time. Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134320.688829863@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/timex.h3
-rw-r--r--kernel/time/ntp.c11
2 files changed, 13 insertions, 1 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h
index d23999f9499d..aa60fe7b6ed6 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -73,7 +73,7 @@ struct timex {
long tolerance; /* clock frequency tolerance (ppm)
* (read only)
*/
- struct timeval time; /* (read only) */
+ struct timeval time; /* (read only, except for ADJ_SETOFFSET) */
long tick; /* (modified) usecs between clock ticks */
long ppsfreq; /* pps frequency (scaled ppm) (ro) */
@@ -102,6 +102,7 @@ struct timex {
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
#define ADJ_TAI 0x0080 /* set TAI offset */
+#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
#define ADJ_TICK 0x4000 /* tick value */
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index ed8cfdf16983..5ac593267a26 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -648,6 +648,17 @@ int do_adjtimex(struct timex *txc)
hrtimer_cancel(&leap_timer);
}
+ if (txc->modes & ADJ_SETOFFSET) {
+ struct timespec delta;
+ if ((unsigned long)txc->time.tv_usec >= NSEC_PER_SEC)
+ return -EINVAL;
+ delta.tv_sec = txc->time.tv_sec;
+ delta.tv_nsec = txc->time.tv_usec;
+ if (!(txc->modes & ADJ_NANO))
+ delta.tv_nsec *= 1000;
+ timekeeping_inject_offset(&delta);
+ }
+
getnstimeofday(&ts);
write_seqlock_irq(&xtime_lock);