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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-05-31 08:16:24 (GMT) |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-06-13 13:58:20 (GMT) |
| commit | 4027789192d149678262ad606b2d7e2a61bed0f2 (patch) | |
| tree | cb58f29b1ddf8e1f06eee12c67fa2a846ee0e7ad /drivers/s390 | |
| parent | 9dc06ccf4699db81b88a6ff45a8acefd6c278327 (diff) | |
| download | linux-4027789192d149678262ad606b2d7e2a61bed0f2.tar.xz | |
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>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/block/dasd_eckd.c | 4 |
1 files changed, 2 insertions, 2 deletions
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 @@ check_XRC (struct ccw1 *de_ccw, 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 @@ static int check_XRC_on_prefix(struct PFX_eckd_data *pfxdata, 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; |