s390/time: LPAR offset handling
It is possible to specify a user offset for the TOD clock, e.g. +2 hours.
The TOD clock will carry this offset even if the clock is synchronized
with STP. This makes the time stamps acquired with get_sync_clock()
useless as another LPAR migth use a different TOD offset.
Use the PTFF instrution to get the TOD epoch difference and subtract
it from the TOD clock value to get a physical timestamp. As the epoch
difference contains the sync check delta as well the LPAR offset value
to the physical clock needs to be refreshed after each clock
synchronization.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 42b34cd..fd2eff4 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -228,7 +228,7 @@
data->ga_extended |= 0x08; /* switch on 'Time Stamp Valid' */
data->ga_extended |= 0x02; /* switch on 'Extended Parameter' */
- rc = get_sync_clock(&data->ep_sys_time);
+ rc = get_phys_clock(&data->ep_sys_time);
/* Ignore return code if sync clock is switched off. */
if (rc == -EOPNOTSUPP || rc == -EACCES)
rc = 0;
@@ -339,7 +339,7 @@
pfxdata->define_extent.ga_extended |= 0x02; /* 'Extended Parameter' */
pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid' */
- rc = get_sync_clock(&pfxdata->define_extent.ep_sys_time);
+ rc = get_phys_clock(&pfxdata->define_extent.ep_sys_time);
/* Ignore return code if sync clock is switched off. */
if (rc == -EOPNOTSUPP || rc == -EACCES)
rc = 0;