From patchwork Thu Mar 22 16:26:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10301849 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DB82460216 for ; Thu, 22 Mar 2018 16:27:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEA4D2879B for ; Thu, 22 Mar 2018 16:27:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C30E1287A0; Thu, 22 Mar 2018 16:27:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 73AA6287A6 for ; Thu, 22 Mar 2018 16:27:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751375AbeCVQ06 (ORCPT ); Thu, 22 Mar 2018 12:26:58 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:33602 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbeCVQ05 (ORCPT ); Thu, 22 Mar 2018 12:26:57 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id F2A8060F72; Thu, 22 Mar 2018 16:26:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521736017; bh=PGLaKXGmKlIUzhwmOqVi79a4k9rslAyuE0MyI3mwmdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IZ9kcwjX0VA42dSNODVmNSgpJhP3oeEEInArPpzRDCWGI41173sAic6jMn/1ZUTFg mb/wCFWzc11yWlP9KMPQIudTxI/dC9wAeCvok2VJ93ng/rejOYetNS7sFRLhI896Zs qE9NsxduFy5es/AmBArgFMxxWzGpANdeaSKPwC/A= Received: from drakthul.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 1BF3460C64; Thu, 22 Mar 2018 16:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521736016; bh=PGLaKXGmKlIUzhwmOqVi79a4k9rslAyuE0MyI3mwmdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MA2VCt8QF+EHDuCd3YZ80eoOIITWyGR5bjPNA3KNMFf8UH7toQ849fEBNSh97sNje MUX8D/ECjosbVvyp9nII9086txm3D4ls5viPcTwD7Qa2gopOqb7UGu62b8UU4hKDBV D2J5jzeDBsVE1pmAhcGize1tnU5sprozneKpHCwI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1BF3460C64 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: linux-rdma@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Selvin Xavier , Devesh Sharma , Somnath Kotur , Sriharsha Basavapatna , Doug Ledford , Jason Gunthorpe , linux-kernel@vger.kernel.org Subject: [PATCH v5 1/3] RDMA/bnxt_re: Eliminate duplicate barriers on weakly-ordered archs Date: Thu, 22 Mar 2018 12:26:47 -0400 Message-Id: <1521736009-23387-2-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521736009-23387-1-git-send-email-okaya@codeaurora.org> References: <1521736009-23387-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 9 +++++---- 1 file changed, 5 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..10f9a26 100644 --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c @@ -181,10 +181,11 @@ 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); + mmiowb(); done: spin_unlock_irqrestore(&cmdq->lock, flags); /* Return the CREQ response pointer */