timekeeping: Increase granularity of read_persistent_clock()

[mv-sheeva.git] / arch / s390 / kernel / time.c

diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index e76c2e7a8b9a17c37e5e9b25b1847725b2fef6c7..a94ec48587b480fe52f150c1323a7f29e17a3e99 100644 (file)
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -182,12 +182,9 @@ static void timing_alert_interrupt(__u16 code)
 static void etr_reset(void);
 static void stp_reset(void);
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-       struct timespec ts;
-
-       tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, &ts);
-       return ts.tv_sec;
+       tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts);
 }
 
 static cycle_t read_tod_clock(struct clocksource *cs)
@@ -248,7 +245,6 @@ void __init time_init(void)
 {
        struct timespec ts;
        unsigned long flags;
-       cycle_t now;
 
        /* Reset time synchronization interfaces. */
        etr_reset();
@@ -266,20 +262,10 @@ void __init time_init(void)
                panic("Could not register TOD clock source");
 
        /*
-        * The TOD clock is an accurate clock. The xtime should be
-        * initialized in a way that the difference between TOD and
-        * xtime is reasonably small. Too bad that timekeeping_init
-        * sets xtime.tv_nsec to zero. In addition the clock source
-        * change from the jiffies clock source to the TOD clock
-        * source add another error of up to 1/HZ second. The same
-        * function sets wall_to_monotonic to a value that is too
-        * small for /proc/uptime to be accurate.
-        * Reset xtime and wall_to_monotonic to sane values.
+        * Reset wall_to_monotonic to the initial timestamp created
+        * in head.S to get a precise value in /proc/uptime.
         */
        write_seqlock_irqsave(&xtime_lock, flags);
-       now = get_clock();
-       tod_to_timeval(now - TOD_UNIX_EPOCH, &xtime);
-       clocksource_tod.cycle_last = now;
        tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &ts);
        set_normalized_timespec(&wall_to_monotonic, -ts.tv_sec, -ts.tv_nsec);
        write_sequnlock_irqrestore(&xtime_lock, flags);