linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: okaya@codeaurora.org (Sinan Kaya)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 1/6] RDMA/bnxt_re: Eliminate duplicate barriers on weakly-ordered archs
Date: Mon, 19 Mar 2018 22:47:43 -0400	[thread overview]
Message-ID: <1521514068-8856-2-git-send-email-okaya@codeaurora.org> (raw)
In-Reply-To: <1521514068-8856-1-git-send-email-okaya@codeaurora.org>

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.

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

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
index 8329ec6..4a6b981 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
@@ -181,10 +181,10 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw, struct cmdq_base *req,
 
 	/* ring CMDQ DB */
 	wmb();
-	writel(cmdq_prod, rcfw->cmdq_bar_reg_iomem +
-	       rcfw->cmdq_bar_reg_prod_off);
-	writel(RCFW_CMDQ_TRIG_VAL, rcfw->cmdq_bar_reg_iomem +
-	       rcfw->cmdq_bar_reg_trig_off);
+	writel_relaxed(cmdq_prod, rcfw->cmdq_bar_reg_iomem +
+		       rcfw->cmdq_bar_reg_prod_off);
+	writel_relaxed(RCFW_CMDQ_TRIG_VAL, rcfw->cmdq_bar_reg_iomem +
+		       rcfw->cmdq_bar_reg_trig_off);
 done:
 	spin_unlock_irqrestore(&cmdq->lock, flags);
 	/* Return the CREQ response pointer */
-- 
2.7.4

  reply	other threads:[~2018-03-20  2:47 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-20  2:47 [PATCH v4 0/6] ib: Eliminate duplicate barriers on weakly-ordered archs Sinan Kaya
2018-03-20  2:47 ` Sinan Kaya [this message]
2018-03-20 14:48   ` [PATCH v4 1/6] RDMA/bnxt_re: " Jason Gunthorpe
2018-03-20 15:00     ` Sinan Kaya
2018-03-20 15:08       ` Sinan Kaya
2018-03-20 15:23         ` Jason Gunthorpe
2018-03-20 15:20       ` Jason Gunthorpe
2018-03-20 15:30         ` Sinan Kaya
2018-03-20 16:02           ` Jason Gunthorpe
2018-03-20  2:47 ` [PATCH v4 2/6] IB/mlx4: " Sinan Kaya
2018-03-20 14:48   ` Jason Gunthorpe
2018-03-20  2:47 ` [PATCH v4 3/6] RDMA/i40iw: " Sinan Kaya
2018-03-20 14:56   ` Jason Gunthorpe
2018-03-21 13:38   ` Shiraz Saleem
2018-03-21 20:02   ` Jason Gunthorpe
2018-03-21 21:01     ` Sinan Kaya
2018-03-20  2:47 ` [PATCH v4 4/6] infiniband: cxgb4: " Sinan Kaya
2018-03-20 14:51   ` Jason Gunthorpe
2018-03-20 15:10     ` Steve Wise
2018-03-20 15:38     ` Steve Wise
2018-03-22  6:44   ` kbuild test robot
2018-03-22 12:24     ` okaya at codeaurora.org
2018-03-22 12:48       ` okaya at codeaurora.org
2018-03-22 14:33         ` Sinan Kaya
2018-03-22 14:40         ` Steve Wise
2018-03-22 14:52           ` Sinan Kaya
2018-03-22 16:28             ` Steve Wise
2018-03-22 19:44               ` Casey Leedom
2018-03-22 20:16                 ` Jason Gunthorpe
2018-03-22 20:45                   ` Casey Leedom
2018-03-22 21:25                     ` Jason Gunthorpe
2018-03-22 21:27                     ` Sinan Kaya
2018-03-22 22:02                       ` Casey Leedom
     [not found]         ` <437ab002-b8db-24aa-583e-0e61d61aaa97@codeaurora.org>
2018-03-22 18:46           ` Jason Gunthorpe
2018-03-22 18:48         ` Jason Gunthorpe
2018-03-22 18:58           ` Sinan Kaya
2018-03-23  4:14   ` kbuild test robot
2018-03-20  2:47 ` [PATCH v4 5/6] IB/nes: " Sinan Kaya
2018-03-20 14:54   ` Jason Gunthorpe
2018-03-20 15:23     ` Sinan Kaya
2018-03-20 16:01       ` Jason Gunthorpe
2018-03-20 16:08         ` Sinan Kaya
2018-03-20 16:29           ` Jason Gunthorpe
2018-03-20  2:47 ` [PATCH v4 6/6] RDMA/qedr: eliminate duplicate barriers on weakly-ordered archs #2 Sinan Kaya
2018-03-20  7:38   ` Kalderon, Michal
2018-03-20 14:55   ` Jason Gunthorpe
2018-03-21 20:08 ` [PATCH v4 0/6] ib: Eliminate duplicate barriers on weakly-ordered archs Jason Gunthorpe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1521514068-8856-2-git-send-email-okaya@codeaurora.org \
    --to=okaya@codeaurora.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).