s390/atomic: optimize atomic_add() for constant values

Browse source

If the interlocked-access facility 1 is available we can use the asi
and agsi instructions for interlocked updates if the to be added
value is a contanst and small (in the range of -128..127).
asi and agsi do not not return the old or new value, therefore these
instructions can only be used for atomic_(add|sub|inc|dec)[64].

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

...

This commit is contained in:

Heiko Carstens 2013-09-16 10:44:54 +02:00 • committed by Martin Schwidefsky

parent eddf0d5b31

commit 5692e4d11c

1 changed files with 40 additions and 8 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

48

arch/s390/include/asm/atomic.h

View file