From patchwork Wed Mar 14 03:20:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 885598 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="iK1k1KLm"; dkim=pass (1024-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="iK1k1KLm"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 401H8d57GSz9sV5 for ; Wed, 14 Mar 2018 14:22:25 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933358AbeCNDUi (ORCPT ); Tue, 13 Mar 2018 23:20:38 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43090 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932937AbeCNDUg (ORCPT ); Tue, 13 Mar 2018 23:20:36 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E0E0960851; Wed, 14 Mar 2018 03:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997635; bh=zqEDc5+sVTJuqPfrwG2GU85GD5muqnwKbTmbuxIGE+Y=; h=From:To:Cc:Subject:Date:From; b=iK1k1KLmr6OdDgzdNXBW1z/H9i7ewYbt1TKlgYE+TfIi5FRkcA0j1JDw1l54rKqOY nWpuCtTv2Gdr6pmR7KsgjVkqLh6cB6UOrZA8ogW2Pa5GtiMP55zL/Dn+xOZo5YraJj qAYHRFLek6ztJo0jp33Dwipi64tUY1aogbueTDhM= 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 8142F607A2; Wed, 14 Mar 2018 03:20:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997635; bh=zqEDc5+sVTJuqPfrwG2GU85GD5muqnwKbTmbuxIGE+Y=; h=From:To:Cc:Subject:Date:From; b=iK1k1KLmr6OdDgzdNXBW1z/H9i7ewYbt1TKlgYE+TfIi5FRkcA0j1JDw1l54rKqOY nWpuCtTv2Gdr6pmR7KsgjVkqLh6cB6UOrZA8ogW2Pa5GtiMP55zL/Dn+xOZo5YraJj qAYHRFLek6ztJo0jp33Dwipi64tUY1aogbueTDhM= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8142F607A2 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 1/7] i40e/i40evf: Eliminate duplicate barriers on weakly-ordered archs Date: Tue, 13 Mar 2018 23:20:22 -0400 Message-Id: <1520997629-17361-1-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 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/i40e/i40e_txrx.c | 2 +- drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index e554aa6cf..7028516 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1375,7 +1375,7 @@ static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val) * such as IA-64). */ wmb(); - writel(val, rx_ring->tail); + writel_relaxed(val, rx_ring->tail); } /** diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 357d605..2d323fc 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -667,7 +667,7 @@ static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val) * such as IA-64). */ wmb(); - writel(val, rx_ring->tail); + writel_relaxed(val, rx_ring->tail); } /**