s390/cio: convert cfg_lock mutex to spinlock
authorSebastian Ott <sebott@linux.vnet.ibm.com>
Tue, 19 Jul 2016 08:43:26 +0000 (10:43 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Sun, 31 Jul 2016 09:27:57 +0000 (05:27 -0400)
commit837c5220557270e652d89f68a9fb12a5e72e8a7a
treeab60a16d9c19efc26e5a9253bcf96703cd1b65b7
parentbc29b7ac1d9f09f5024b0e257e91bf5df611ccd4
s390/cio: convert cfg_lock mutex to spinlock

cfg_lock is never held long and we don't want to sleep while the
lock is being held. Thus it can be converted to a simple spinlock.
In addition we can now use the lock during the evaluation of a
wake_up condition.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/cio/chp.c