X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Ftime.c;h=167a72a078ea9237937cf865f975ae8522bc714a;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=68c22f2bf4527254c90121c03b5ebbd110928eb0;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git

diff --git a/kernel/time.c b/kernel/time.c
index 68c22f2bf..167a72a07 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -22,6 +22,9 @@
  *	"A Kernel Model for Precision Timekeeping" by Dave Mills
  *	Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
  *	(Even though the technical memorandum forbids it)
+ * 2004-07-14	 Christoph Lameter
+ *	Added getnstimeofday to allow the posix timer functions to return
+ *	with nanosecond accuracy
  */
 
 #include <linux/module.h>
@@ -123,7 +126,7 @@ inline static void warp_clock(void)
 	write_seqlock_irq(&xtime_lock);
 	wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
 	xtime.tv_sec += sys_tz.tz_minuteswest * 60;
-	time_interpolator_update(sys_tz.tz_minuteswest * 60 * NSEC_PER_SEC);
+	time_interpolator_reset();
 	write_sequnlock_irq(&xtime_lock);
 	clock_was_set();
 }
@@ -421,6 +424,103 @@ struct timespec current_kernel_time(void)
 
 EXPORT_SYMBOL(current_kernel_time);
 
+#ifdef CONFIG_TIME_INTERPOLATION
+void getnstimeofday (struct timespec *tv)
+{
+	unsigned long seq,sec,nsec;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		sec = xtime.tv_sec;
+		nsec = xtime.tv_nsec+time_interpolator_get_offset();
+	} while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+	while (unlikely(nsec >= NSEC_PER_SEC)) {
+		nsec -= NSEC_PER_SEC;
+		++sec;
+	}
+	tv->tv_sec = sec;
+	tv->tv_nsec = nsec;
+}
+
+int do_settimeofday (struct timespec *tv)
+{
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
+	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	write_seqlock_irq(&xtime_lock);
+	{
+		/*
+		 * This is revolting. We need to set "xtime" correctly. However, the value
+		 * in this location is the value at the most recent update of wall time.
+		 * Discover what correction gettimeofday would have done, and then undo
+		 * it!
+		 */
+		nsec -= time_interpolator_get_offset();
+
+		wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+		wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+		set_normalized_timespec(&xtime, sec, nsec);
+		set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
+		time_adjust = 0;		/* stop active adjtime() */
+		time_status |= STA_UNSYNC;
+		time_maxerror = NTP_PHASE_LIMIT;
+		time_esterror = NTP_PHASE_LIMIT;
+		time_interpolator_reset();
+	}
+	write_sequnlock_irq(&xtime_lock);
+	clock_was_set();
+	return 0;
+}
+
+EXPORT_SYMBOL(do_settimeofday);
+
+void do_gettimeofday (struct timeval *tv)
+{
+	unsigned long seq, nsec, usec, sec, offset;
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		offset = time_interpolator_get_offset();
+		sec = xtime.tv_sec;
+		nsec = xtime.tv_nsec;
+	} while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+	usec = (nsec + offset) / 1000;
+
+	while (unlikely(usec >= USEC_PER_SEC)) {
+		usec -= USEC_PER_SEC;
+		++sec;
+	}
+
+	tv->tv_sec = sec;
+	tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+#else
+/*
+ * Simulate gettimeofday using do_gettimeofday which only allows a timeval
+ * and therefore only yields usec accuracy
+ */
+void getnstimeofday(struct timespec *tv)
+{
+	struct timeval x;
+
+	do_gettimeofday(&x);
+	tv->tv_sec = x.tv_sec;
+	tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
+}
+#endif
+
+EXPORT_SYMBOL(getnstimeofday);
+
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
 {