[PATCH V8 02/13] ntp: add ADJ_SETOFFSET mode bit

Richard Cochran
2010-12-31T19:12:41Z

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-3mrvs1K0uXizZXS1Dc/lvw@public.gmane.org>
---
include/linux/timex.h | 3 ++-
kernel/time/ntp.c | 11 +++++++++++
2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/include/linux/timex.h b/include/linux/timex.h
index 32d852f..82d4b24 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) */
@@ -101,6 +101,7 @@ struct timex {
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
+#define ADJ_SETOFFSET 0x0040 /* add 'time' to current time */
#define ADJ_TAI 0x0080 /* set TAI offset */
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index d232189..0c87858 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -482,6 +482,17 @@ 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);
--
1.7.0.4