From 2f82f57763d97700788cf228de1cf30ffd4153b4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 31 May 2016 09:09:57 +0200 Subject: [PATCH] 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 --- arch/s390/include/asm/cio.h | 2 +- arch/s390/kernel/time.c | 11 +++++------ drivers/s390/cio/chsc.c | 8 ++++++-- 3 files changed, 12 insertions(+), 9 deletions(-) diff --git a/arch/s390/include/asm/cio.h b/arch/s390/include/asm/cio.h index d1e7b0a0feeb..f7ed88cc066e 100644 --- a/arch/s390/include/asm/cio.h +++ b/arch/s390/include/asm/cio.h @@ -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 diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 9409d32f285e..a725fd1c4315 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -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; diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c index c424c0c7367e..452193f7298c 100644 --- a/drivers/s390/cio/chsc.c +++ b/drivers/s390/cio/chsc.c @@ -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; }