s390/time: STP sync clock correction
The sync clock operation of the channel subsystem call for STP delivers
the TOD clock difference as a result. Use this TOD clock difference
instead of the difference between the TOD timestamps before and after
the sync clock operation.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/cio.h b/arch/s390/include/asm/cio.h
index d1e7b0a..f7ed88c 100644
--- a/arch/s390/include/asm/cio.h
+++ b/arch/s390/include/asm/cio.h
@@ -320,7 +320,7 @@
extern int cio_get_iplinfo(struct cio_iplinfo *iplinfo);
/* Function from drivers/s390/cio/chsc.c */
-int chsc_sstpc(void *page, unsigned int op, u16 ctrl);
+int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta);
int chsc_sstpi(void *page, void *result, size_t size);
#endif
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 9409d32..a725fd1 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -1455,7 +1455,7 @@
int rc;
stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
- rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
if (rc == 0)
set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
else if (stp_online) {
@@ -1554,11 +1554,10 @@
stp_info.todoff[2] || stp_info.todoff[3] ||
stp_info.tmd != 2) {
old_clock = get_tod_clock();
- rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);
+ rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, &clock_delta);
if (rc == 0) {
- new_clock = get_tod_clock();
+ new_clock = old_clock + clock_delta;
delta = adjust_time(old_clock, new_clock, 0);
- clock_delta = new_clock - old_clock;
atomic_notifier_call_chain(&s390_epoch_delta_notifier,
0, &clock_delta);
fixup_clock_comparator(delta);
@@ -1590,12 +1589,12 @@
mutex_lock(&stp_work_mutex);
if (!stp_online) {
- chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
del_timer_sync(&stp_timer);
goto out_unlock;
}
- rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL);
if (rc)
goto out_unlock;