From patchwork Fri Mar 16 16:16:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10289001 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 B2E0D6063D for ; Fri, 16 Mar 2018 16:18:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A2AEC28FB7 for ; Fri, 16 Mar 2018 16:18:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 96D2128FBB; Fri, 16 Mar 2018 16:18:21 +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 CEA7028FBA for ; Fri, 16 Mar 2018 16:18:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762AbeCPQRQ (ORCPT ); Fri, 16 Mar 2018 12:17:16 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39958 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754745AbeCPQRN (ORCPT ); Fri, 16 Mar 2018 12:17:13 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id AFA7360A50; Fri, 16 Mar 2018 16:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521217032; bh=u4onTMB/28dcawklWyavj35azfqXL6UF/ueOPVhCk7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kmjvbVhgONiqh4pMJEf+hncO8n4O5y2wHH9X2jHBLpH6O/C/t+szRlgOHFlS6jqFa VYIKNeogPLhnF9uwcL/kBdaPt+aS4thfuy2TMYBvy6CGX5Xu0DL1UMMDIo4zhHfpxi pRIFH6F2oqz402hOwXJFC+gQloTy+KqsmIkE3890= 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 846EF60F71; Fri, 16 Mar 2018 16:17:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521217031; bh=u4onTMB/28dcawklWyavj35azfqXL6UF/ueOPVhCk7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kBGkwJL6MH38zFoYna4zRlzCeJjfTRyM95pRir8/Szur6CISkcUkcV09AwRsYokul zLsc7VWzjOV1kf2wCV0+LW7JLhh3hvJ/8tEjYH03/43mDTrRPPwqul03jDO5OEj03N rE7IKxlbZ4EVgKpOMLQVRwlJ5PRApi5fF+hFBz4Y= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 846EF60F71 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: netdev@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-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 15/18] RDMA/bnxt_re: Eliminate duplicate barriers on weakly-ordered archs Date: Fri, 16 Mar 2018 12:16:28 -0400 Message-Id: <1521216991-28706-16-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521216991-28706-1-git-send-email-okaya@codeaurora.org> References: <1521216991-28706-1-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 | 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 */