• Gerald Schaefer's avatar
    s390/ipl: add support to control memory clearing for FCP and CCW re-IPL · 1a2ae03b
    Gerald Schaefer authored
    Re-IPL for both CCW and FCP is currently done by using diag 308 with the
    "Load Clear" subcode, which means that all memory will be cleared.
    This can increase re-IPL duration considerably on very large machines.
    
    For CCW devices, there is also a "Load Normal" subcode that was only used
    for dump kernels so far. For FCP devices, a similar "Load Normal" subcode
    was introduced with z14. The "Load Normal" diag 308 subcode allows to
    re-IPL without clearing memory.
    
    This patch adds a new "clear" sysfs attribute to /sys/firmware/reipl for
    both the ccw and fcp subdirectories, which can be set to either "0" or "1"
    to disable or enable re-IPL with memory clearing. The default value is "0",
    which disables memory clearing.
    Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
    Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
    1a2ae03b
ipl.c 47.7 KB