From d54853ef8cb17296ac7bce9c77430fb7c80532d0 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 5 Feb 2007 21:18:19 +0100 Subject: [S390] ETR support. This patch adds support for clock synchronization to an external time reference (ETR). The external time reference sends an oscillator signal and a synchronization signal every 2^20 microseconds to keep the TOD clocks of all connected servers in sync. For availability two ETR units can be connected to a machine. If the clock deviates for more than the sync-check tolerance all cpus get a machine check that indicates that the clock is out of sync. For the lovely details how to get the clock back in sync see the code below. Signed-off-by: Martin Schwidefsky --- drivers/s390/s390mach.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/s390/s390mach.h') diff --git a/drivers/s390/s390mach.h b/drivers/s390/s390mach.h index 7abb42a09ae..d3ca4281a49 100644 --- a/drivers/s390/s390mach.h +++ b/drivers/s390/s390mach.h @@ -102,4 +102,7 @@ static inline int stcrw(struct crw *pcrw ) return ccode; } +#define ED_ETR_SYNC 12 /* External damage ETR sync check */ +#define ED_ETR_SWITCH 13 /* External damage ETR switch to local */ + #endif /* __s390mach */ -- cgit v1.2.3