From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03D28C4321A for ; Fri, 28 Jun 2019 22:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEC99208E3 for ; Fri, 28 Jun 2019 22:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbfF1WtH (ORCPT ); Fri, 28 Jun 2019 18:49:07 -0400 Received: from mga12.intel.com ([192.55.52.136]:42186 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726835AbfF1WtG (ORCPT ); Fri, 28 Jun 2019 18:49:06 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jun 2019 15:49:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,429,1557212400"; d="scan'208";a="338039134" Received: from jtkirshe-desk1.jf.intel.com ([134.134.177.96]) by orsmga005.jf.intel.com with ESMTP; 28 Jun 2019 15:49:05 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Venkatesh Srinivas , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, Aaron Brown , Jeff Kirsher Subject: [net-next 05/15] e1000: Use dma_wmb() instead of wmb() before doorbell writes Date: Fri, 28 Jun 2019 15:49:22 -0700 Message-Id: <20190628224932.3389-6-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190628224932.3389-1-jeffrey.t.kirsher@intel.com> References: <20190628224932.3389-1-jeffrey.t.kirsher@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Venkatesh Srinivas e1000 writes to doorbells to post transmit descriptors and fill the receive ring. After writing descriptors to memory but before writing to doorbells, use dma_wmb() rather than wmb(). wmb() is more heavyweight than necessary for a device to see descriptor writes. On x86, this avoids SFENCEs before doorbell writes in both the Tx and Rx paths. On ARM, this converts DSB ST -> DMB OSHST. Tested: 82576EB / x86; QEMU (qemu emulates an 8257x) Signed-off-by: Venkatesh Srinivas Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000/e1000_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 551de8c2fef2..f703fa58458e 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3019,7 +3019,7 @@ static void e1000_tx_queue(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); tx_ring->next_to_use = i; } @@ -4540,7 +4540,7 @@ e1000_alloc_jumbo_rx_buffers(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); writel(i, adapter->hw.hw_addr + rx_ring->rdt); } } @@ -4655,7 +4655,7 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); writel(i, hw->hw_addr + rx_ring->rdt); } } -- 2.21.0