]> git.karo-electronics.de Git - karo-tx-linux.git/commit
s390/bitops: make use of interlocked-access facility 1 instructions
authorHeiko Carstens <heiko.carstens@de.ibm.com>
Tue, 10 Sep 2013 13:35:39 +0000 (15:35 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Tue, 15 Oct 2013 12:45:21 +0000 (14:45 +0200)
commitb7830d2ace57bf7d5cd4ef00ef5725ebfde2e6c2
tree8e6358b31ac5cce52c8927a630ae4b019971d330
parent9784bd4f1a6ea736ad9bf241f5a965e0a2913a5e
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>
arch/s390/include/asm/bitops.h