Fix wallclock timebase extraction in XenLinux.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/xen/i386/kernel/time.c b/linux-2.6-xen-sparse/arch/xen/i386/kernel/time.c
index 38197e67a4961abd7091814c20f93a0915a4247c..7d600b5e1af00a99f3373fb7b06182cac1a893b2 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/i386/kernel/time.c
+++ b/linux-2.6-xen-sparse/arch/xen/i386/kernel/time.c
@@ -227,9 +227,9 @@ static unsigned long get_usec_offset(struct shadow_time_info *shadow)
 static void update_wallclock(void)
 {
        shared_info_t *s = HYPERVISOR_shared_info;
-       long wtm_nsec;
-       time_t wtm_sec, sec;
-       s64 nsec;
+       long wtm_nsec, xtime_nsec;
+       time_t wtm_sec, xtime_sec;
+       u64 tmp, usec;
 
        shadow_tv.tv_sec  = s->wc_sec;
        shadow_tv.tv_usec = s->wc_usec;
@@ -240,20 +240,22 @@ static void update_wallclock(void)
        if ((time_status & STA_UNSYNC) != 0)
                return;
 
-       /* Adjust shadow for jiffies that haven't updated xtime yet. */
-       shadow_tv.tv_usec -= 
-               (jiffies - wall_jiffies) * (USEC_PER_SEC / HZ);
-       HANDLE_USEC_UNDERFLOW(shadow_tv);
+       /* Adjust wall-clock time base based on wall_jiffies ticks. */
+       usec = processed_system_time;
+       do_div(usec, 1000);
+       usec += (u64)shadow_tv.tv_sec * 1000000ULL;
+       usec += (u64)shadow_tv.tv_usec;
+       usec -= (jiffies - wall_jiffies) * (USEC_PER_SEC / HZ);
 
-       /* Update our unsynchronised xtime appropriately. */
-       sec = shadow_tv.tv_sec;
-       nsec = shadow_tv.tv_usec * NSEC_PER_USEC;
+       /* Split wallclock base into seconds and nanoseconds. */
+       tmp = usec;
+       xtime_nsec = do_div(tmp, 1000000) * 1000ULL;
+       xtime_sec  = (time_t)tmp;
 
-       __normalize_time(&sec, &nsec);
-       wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
-       wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+       wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - xtime_sec);
+       wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - xtime_nsec);
 
-       set_normalized_timespec(&xtime, sec, nsec);
+       set_normalized_timespec(&xtime, xtime_sec, xtime_nsec);
        set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 }