From patchwork Tue Mar 20 02:47:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10296059 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 EDA0060385 for ; Tue, 20 Mar 2018 02:49:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE04E28DA8 for ; Tue, 20 Mar 2018 02:49:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D153A28F20; Tue, 20 Mar 2018 02:49:27 +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 5761F28DA8 for ; Tue, 20 Mar 2018 02:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751911AbeCTCsN (ORCPT ); Mon, 19 Mar 2018 22:48:13 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:56248 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752411AbeCTCsG (ORCPT ); Mon, 19 Mar 2018 22:48:06 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 95AB160F6E; Tue, 20 Mar 2018 02:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521514085; bh=wKf1QocbWcihnWVgJtjvqdqWapBnp5hXTUOiu4NtFuw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k3so3hhieVCootMTYJqlvGrB3HiahxbTYr8SZpJrWetWdMO01BYPlKU6iGqB828RW T+sppT/TFW6NhQAFqb7mkd4nEvm8xroDL31g4MVEnuktTrPsldGu1K9STsTgC9de4R A10jm/okfnQfT8GYQqQd3XlkfbWFOQqD1wnyIGRs= 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 7275F60C54; Tue, 20 Mar 2018 02:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521514084; bh=wKf1QocbWcihnWVgJtjvqdqWapBnp5hXTUOiu4NtFuw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QwVALWRtsowQNwABEoWEb+r+vLGByvQFyV/2uD5tIUTEigO7szxpcsRvz82XVGrYc SbJgHhiQRnTFAnNDxghhEtAcaSMOXlO7d6rGC65znuZb8RyYGk5+WlLBgwafdNJcT0 gVUB2Td8931zj32TmOtCDDSGZGHX9pnQ3m+j96Zk= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 7275F60C54 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 , Michal Kalderon , Ariel Elior , Doug Ledford , Jason Gunthorpe , linux-kernel@vger.kernel.org Subject: [PATCH v4 6/6] RDMA/qedr: eliminate duplicate barriers on weakly-ordered archs #2 Date: Mon, 19 Mar 2018 22:47:48 -0400 Message-Id: <1521514068-8856-7-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() in multiple places. 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 Acked-by: Michal Kalderon --- drivers/infiniband/hw/qedr/verbs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c index ccd55f4..db60360 100644 --- a/drivers/infiniband/hw/qedr/verbs.c +++ b/drivers/infiniband/hw/qedr/verbs.c @@ -860,7 +860,7 @@ static void doorbell_cq(struct qedr_cq *cq, u32 cons, u8 flags) wmb(); cq->db.data.agg_flags = flags; cq->db.data.value = cpu_to_le32(cons); - writeq(cq->db.raw, cq->db_addr); + writeq_relaxed(cq->db.raw, cq->db_addr); /* Make sure write would stick */ mmiowb(); @@ -3338,7 +3338,7 @@ int qedr_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr, qp->rq.db_data.data.value++; - writel(qp->rq.db_data.raw, qp->rq.db); + writel_relaxed(qp->rq.db_data.raw, qp->rq.db); /* Make sure write sticks */ mmiowb();