Add support for memory barriers in arch {arm,arm64,x86}. This is required to
force strict CPU ordering. Definitions are based on FREEBSD atomic.h
definitions.
BUG=chrome-os-partner:31533
BRANCH=None
TEST=Memory barriers tested with ehci driver on arm64
Change-Id: Ie51e3452f7a254b24111000da5dbe8714ac22223
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/213916
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Commit-Queue: Furquan Shaikh <furquan@chromium.org>