tree f228f1a90c0d7abb8308f275d0906dd7d1588ba3
parent 8b646bd759086f6090fe27acf414c0b5faa737f4
author Martin Schwidefsky <schwidefsky@de.ibm.com> 1331481567 -0400
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1331481568 -0400

[S390] rework idle code

Whenever the cpu loads an enabled wait PSW it will appear as idle to the
underlying host system. The code in default_idle calls vtime_stop_cpu
which does the necessary voodoo to get the cpu time accounting right.
The udelay code just loads an enabled wait PSW. To correct this rework
the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
to entry[64].S, vtime_stop_cpu can now be called from anywhere and
vtime_start_cpu is gone. The correction of the cpu time during wakeup
from an enabled wait PSW is done with a critical section in entry[64].S.
As vtime_start_cpu is gone, s390_idle_check can be removed as well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>