block: Definition for barrier requests flag

A barrier request is a type of flush request used to control ordering of
write requests without clearing the device's cache. LLD support for
barrier is optional. To maintain backward compatibility, barrier request
has to maintain flush s/w path and flags.
This patch introduces those flags to define interface between the block
layer and the LLD.

Change-Id: Iefa8e9a5c1b5e8256eaeb0322c435becd4669de9
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
[imaund@codeaurora.org: Resolved context conflicts]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
[xiaonian@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>
1 file changed