From patchwork Wed Mar 21 18:56:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10300041 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 5E5F8600F6 for ; Wed, 21 Mar 2018 18:56:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F964298AB for ; Wed, 21 Mar 2018 18:56:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 441F0298BF; Wed, 21 Mar 2018 18:56:42 +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=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AFBB7298B8 for ; Wed, 21 Mar 2018 18:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=syqp5PVOQeSzd7hFzDrKUrBKFvbCs3LnLaMk2FtmpAI=; b=MeMGTorjKq5MFh oCcR5xl5GxBxuVl1iqIIQ4RcFgIRy5OX+O/yuBw+oJcW+0Ef6sNJOjnnfA8VAb94JJoaZfsqgMgSg V0GHpuS+Cr/jG7MJnPoV7a/X1SeqnupSfbrdgzxEG6e5Rzdh1B3iwYDZ6IHZ4uPCtKPTWA42YhMhO UKiSF+hga9ZDdu6jOJEAFG9k/BPjs/iA45UuWhyQGC96nWYhov+T0Q2knC46BYKoiV6VMzyok+LEz lsXxtCN7urq1G5VnxOZIgQ25qD4h/4CgWoWa/IBliutt54yjXaRg/WBPuazHnRQHU1MqT/5kwHHWu w3BL9wUlFHvzCDKxbmsw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1eyiuZ-0002TZ-Ol; Wed, 21 Mar 2018 18:56:35 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1eyiuU-0002Qu-In for linux-arm-kernel@lists.infradead.org; Wed, 21 Mar 2018 18:56:32 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 895D360F72; Wed, 21 Mar 2018 18:56:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521658581; bh=Vx52RT/AwUjgCYqPTGpROGXkGCToQZe1LTchf3OkXDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xbe5/QEqBAEbJguj8YhecaAvgd1f3fVYIhtA9TWagXrI+xTWfkA0/BzZlvPWPaQMh chBLppg5Ndn4b0YgR9nHuGAEnsEvL6cPrHHpcmvaHiCOdL60txgf2c8I5Id/xvL/HO wqyClv3i1PhdqrGFFbzPY4HfwuEELgWHFfFEyIYc= 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 D509760314; Wed, 21 Mar 2018 18:56:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521658580; bh=Vx52RT/AwUjgCYqPTGpROGXkGCToQZe1LTchf3OkXDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GXubTXBpSW4vLzNuaVaAa7QjYL6+NmHicvrRWGK+izhQ3NMGQhht9DoWpA+ogYFQd 0USoj62W+X4SPxIS52xHsJdB/kLfrOhAaAurGZoEQIJoiy9xxfLIKY6lOIJHQaftlA +kZk5QQ+EiiHxFMMLefyDljRoO1iyOQTLhoUnOZc= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D509760314 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: jeffrey.t.kirsher@intel.com Subject: [PATCH REPOST v4 1/7] i40e/i40evf: Eliminate duplicate barriers on weakly-ordered archs Date: Wed, 21 Mar 2018 14:56:05 -0400 Message-Id: <1521658572-26354-2-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521658572-26354-1-git-send-email-okaya@codeaurora.org> References: <1521658572-26354-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180321_115630_683780_5EFDDD88 X-CRM114-Status: GOOD ( 12.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sulrich@codeaurora.org, netdev@vger.kernel.org, timur@codeaurora.org, linux-kernel@vger.kernel.org, Sinan Kaya , intel-wired-lan@lists.osuosl.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 Reviewed-by: Alexander Duyck --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 8 ++++---- drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index e554aa6cf..9455869 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -185,7 +185,7 @@ static int i40e_program_fdir_filter(struct i40e_fdir_filter *fdir_data, /* Mark the data descriptor to be watched */ first->next_to_watch = tx_desc; - writel(tx_ring->next_to_use, tx_ring->tail); + writel_relaxed(tx_ring->next_to_use, tx_ring->tail); return 0; dma_fail: @@ -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); } /** @@ -2258,7 +2258,7 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget) */ wmb(); - writel(xdp_ring->next_to_use, xdp_ring->tail); + writel_relaxed(xdp_ring->next_to_use, xdp_ring->tail); } rx_ring->skb = skb; @@ -3286,7 +3286,7 @@ static inline int i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, /* notify HW of packet */ if (netif_xmit_stopped(txring_txq(tx_ring)) || !skb->xmit_more) { - writel(i, tx_ring->tail); + writel_relaxed(i, tx_ring->tail); /* we need this if more than one processor can write to our tail * at a time, it synchronizes IO on IA64/Altix systems diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 357d605..56eea20 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); } /** @@ -2243,7 +2243,7 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, /* notify HW of packet */ if (netif_xmit_stopped(txring_txq(tx_ring)) || !skb->xmit_more) { - writel(i, tx_ring->tail); + writel_relaxed(i, tx_ring->tail); /* we need this if more than one processor can write to our tail * at a time, it synchronizes IO on IA64/Altix systems