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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2016-05-31 10:16:24 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-06-13 15:58:20 +0200
commit4027789192d149678262ad606b2d7e2a61bed0f2 (patch)
treecb58f29b1ddf8e1f06eee12c67fa2a846ee0e7ad /drivers/s390/block
parents390/time: move PTFF definitions (diff)
downloadlinux-4027789192d149678262ad606b2d7e2a61bed0f2.tar.xz
linux-4027789192d149678262ad606b2d7e2a61bed0f2.zip
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/block')
-rw-r--r--drivers/s390/block/dasd_eckd.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 42b34cd1f002..fd2eff440098 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;