• Martin Schwidefsky's avatar
    [S390] ETR support. · d54853ef
    Martin Schwidefsky authored
    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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    d54853ef
s390_ext.c 3.41 KB