tree c54a58bdbf4bd586668e288dda2163ebf899a83c
parent e6036c0b88962df82a8853971b86a55f09faef40
author Heiko Carstens <heiko.carstens@de.ibm.com> 1378820139 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1382627804 +0200

s390/bitops: make use of interlocked-access facility 1 instructions

Make use of the interlocked-access facility 1 that got added with the
z196 architecure.
This facilility added new instructions which can atomically update a
storage location without a compare-and-swap loop. E.g. setting a bit
within a "long" can be done with a single instruction.

The size of the kernel image gets ~30kb smaller. Considering that there
are appr. 1900 bitops call sites this means that each one saves about
15-16 bytes per call site which is expected.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>