use dmb barrier instruction for atomics on arm v7
authorRich Felker <dalias@aerifal.cx>
Tue, 15 Apr 2014 03:41:49 +0000 (23:41 -0400)
committerRich Felker <dalias@aerifal.cx>
Tue, 15 Apr 2014 03:41:49 +0000 (23:41 -0400)
commit3933fdd5001cc72cb1ea8bb92bbe536b8b601504
tree281c79dd4a6ea846193d1f28ca48222c54da9146
parent83c98aac4c43f9571e8f92a1c795afe02c237d4b
use dmb barrier instruction for atomics on arm v7

aside from potentially offering better performance, this change is
needed since the old coprocessor-based approach to barriers is
deprecated in arm v7, and some compilers/assemblers issue errors when
using the deprecated instruction for v7 targets.
arch/arm/atomic.h