From patchwork Wed Mar 14 03:20:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 885594 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=codeaurora.org header.i=@codeaurora.org header.b="YuGg0fK7"; dkim=pass (1024-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ZaAoybOc"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 401H7W0qZGz9sV5 for ; Wed, 14 Mar 2018 14:21:27 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933497AbeCNDVQ (ORCPT ); Tue, 13 Mar 2018 23:21:16 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43588 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933429AbeCNDUp (ORCPT ); Tue, 13 Mar 2018 23:20:45 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E550960867; Wed, 14 Mar 2018 03:20:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997645; bh=ka8d+sT21K8+IXcE+cWsjS54nGzKj2ZImZ7FtVdRJzA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YuGg0fK7JuPPekS+m0hZulI7NMy2tUEAFkpohk/M/aDebWGcLAK5yTuay8fyIXIP3 gDKZ+hDVZk7gxDIO/jRQIeQPeFQR1I26Q7FU64L1Cv6LrYZqhG8R4Ohq6tcnFmAa3g 8Hh7uiOL05Xqmfoy29VkYoiAKbMgTxEIold6j02E= X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=2.0 tests=ALL_TRUSTED,BAYES_00, DKIM_SIGNED, T_DKIM_INVALID autolearn=no autolearn_force=no version=3.4.0 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 4514460867; Wed, 14 Mar 2018 03:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997643; bh=ka8d+sT21K8+IXcE+cWsjS54nGzKj2ZImZ7FtVdRJzA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZaAoybOcfcXDudn3l4rK/WTsFv80md9V04DjOP2vnZDy8Ay3sABfAQYQL9mmNNnt0 up/KQA2A8Lm/sJedsvl1VNW3zGwgi/7LEFwHHlXsUwgcr6HTb4+MrC4Bgq66JGWE27 ypn/rTsmrxRpHEeHdZDZ8vBo5hu6kNXgzFmZN5Ok= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4514460867 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 , Jeff Kirsher , intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/7] e1000: eliminate duplicate barriers on weakly-ordered archs Date: Tue, 13 Mar 2018 23:20:27 -0400 Message-Id: <1520997629-17361-6-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1520997629-17361-1-git-send-email-okaya@codeaurora.org> References: <1520997629-17361-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.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 --- drivers/net/ethernet/intel/e1000/e1000_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 3dd4aeb..e0e583a 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -4573,7 +4573,7 @@ e1000_alloc_jumbo_rx_buffers(struct e1000_adapter *adapter, * such as IA-64). */ wmb(); - writel(i, adapter->hw.hw_addr + rx_ring->rdt); + writel_relaxed(i, adapter->hw.hw_addr + rx_ring->rdt); } } @@ -4688,7 +4688,7 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, * such as IA-64). */ wmb(); - writel(i, hw->hw_addr + rx_ring->rdt); + writel_relaxed(i, hw->hw_addr + rx_ring->rdt); } }