From patchwork Tue Mar 20 02:47:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10296039 X-Patchwork-Delegate: jgg@ziepe.ca 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 9AA81602C2 for ; Tue, 20 Mar 2018 02:48:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8956128C0D for ; Tue, 20 Mar 2018 02:48:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7DA6528C79; Tue, 20 Mar 2018 02:48:12 +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 1881228C0D for ; Tue, 20 Mar 2018 02:48:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752402AbeCTCsE (ORCPT ); Mon, 19 Mar 2018 22:48:04 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:55824 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752076AbeCTCr6 (ORCPT ); Mon, 19 Mar 2018 22:47:58 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 1467360314; Tue, 20 Mar 2018 02:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521514077; bh=u4onTMB/28dcawklWyavj35azfqXL6UF/ueOPVhCk7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JVaj/rECdol6aSzTQr9KB26QiqvREO0ZsYoZ7KbGPcLQwvi/iw+GyfO+U9dn0taGZ DB3L0fnNmzL8jmgc9g8AkRkL+cJ6QAm7nvvxHIiBp2vdokiifqWHbuNMNEngUDEoZg rtvLjp/RbiH09h9GTQBXjdqTbSqExR36EERUCASo= 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 0D57D6081C; Tue, 20 Mar 2018 02:47:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521514075; bh=u4onTMB/28dcawklWyavj35azfqXL6UF/ueOPVhCk7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hg9J9vYZN5VzKkl5r8dvYR8X0YrQqdpkZFws9ofeRQu8gW7twpOlLWwd9fZTI3pzh Sa5WLE5Mxf209zgeAZ7VTyFIYh2+jAudfRgJO/QpP+X/O0yYUePxhtdW14NFR682pX oLVHfO6YnPlDkz63THMeEXQ9yB6t9Nx9jpzLIhNk= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 0D57D6081C 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 v4 1/6] RDMA/bnxt_re: Eliminate duplicate barriers on weakly-ordered archs Date: Mon, 19 Mar 2018 22:47:43 -0400 Message-Id: <1521514068-8856-2-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521514068-8856-1-git-send-email-okaya@codeaurora.org> References: <1521514068-8856-1-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 */