[PATCH v4 3/6] RDMA/i40iw: Eliminate duplicate barriers on weakly-ordered archs

On Mon, Mar 19, 2018 at 10:47:45PM -0400, Sinan Kaya wrote:

Code includes wmb() followed by writel(). writel() already has a barrier on
some architectures like arm64.

This ends up CPU observing two barriers back to back before executing the
register write.

Create a new wrapper function with relaxed write operator. Use the new
wrapper when a write is following a wmb().

Since code already has an explicit barrier call, changing writel() to
writel_relaxed().

Signed-off-by: Sinan Kaya <redacted>
 drivers/infiniband/hw/i40iw/i40iw_ctrl.c  |  6 ++++--
 drivers/infiniband/hw/i40iw/i40iw_osdep.h |  1 +
 drivers/infiniband/hw/i40iw/i40iw_uk.c    |  2 +-
 drivers/infiniband/hw/i40iw/i40iw_utils.c | 11 +++++++++++
 4 files changed, 17 insertions(+), 3 deletions(-)

The one looks fine

Reviewed-by: Jason Gunthorpe <redacted>

Jason