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s390/time: STP sync clock correction

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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>
This commit is contained in:
Martin Schwidefsky 2016-05-31 09:09:57 +02:00
parent 4e042af463
commit 2f82f57763
3 changed files with 12 additions and 9 deletions
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2
arch/s390/include/asm/cio.h
View File

@ -320,7 +320,7 @@ struct cio_iplinfo {
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

11
arch/s390/kernel/time.c
View File

@ -1455,7 +1455,7 @@ static void __init stp_reset(void)
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 @@ static int stp_sync_clock(void *data)
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 @@ static void stp_work_fn(struct work_struct *work)
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;

8
drivers/s390/cio/chsc.c
View File

@ -1176,7 +1176,7 @@ exit:
EXPORT_SYMBOL_GPL(css_general_characteristics);
EXPORT_SYMBOL_GPL(css_chsc_characteristics);
int chsc_sstpc(void *page, unsigned int op, u16 ctrl)
int chsc_sstpc(void *page, unsigned int op, u16 ctrl, u64 *clock_delta)
{
struct {
struct chsc_header request;
@ -1186,7 +1186,9 @@ int chsc_sstpc(void *page, unsigned int op, u16 ctrl)
unsigned int ctrl : 16;
unsigned int rsvd2[5];
struct chsc_header response;
unsigned int rsvd3[7];
unsigned int rsvd3[3];
u64 clock_delta;
unsigned int rsvd4[2];
} __attribute__ ((packed)) *rr;
int rc;
@ -1200,6 +1202,8 @@ int chsc_sstpc(void *page, unsigned int op, u16 ctrl)
if (rc)
return -EIO;
rc = (rr->response.code == 0x0001) ? 0 : -EIO;
if (clock_delta)
*clock_delta = rr->clock_delta;
return rc;
}