Commit 08d07968 authored by Committed by Martin SchwidefskyBrowse files
[S390] Standby cpu activation/deactivation.
Add a new interface so that cpus can be put into standby state and configured state. Only offline cpus can be put into standby state or configured state. For that the new percpu sysfs attribute "configure" must be used. To put a cpu in standby state a "0" must be written to the attribute. In order to switch it into configured state a "1" must be written to the attribute. Only cpus in configured state can be brought online. In addition this patch introduces a static mapping of physical to logical cpus. As a result only the sysfs directories of present cpus will be created. To scan for new cpus the new sysfs attribute "rescan" must be used. Writing to /sys/devices/system/cpu/rescan will trigger a rescan of cpus and will create directories for new cpus. On IPL only configured cpus will be used. And on reboot/shutdown all cpus will remain in their current state (configured/standby). Signed-off-by: Heiko Carstens <email@example.com> Signed-off-by: Martin Schwidefsky <firstname.lastname@example.org>