From patchwork Thu Feb 11 16:18:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sven Van Asbroeck X-Patchwork-Id: 381559 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 0441AC433DB for ; Thu, 11 Feb 2021 16:22:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF06964E8B for ; Thu, 11 Feb 2021 16:22:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231766AbhBKQVz (ORCPT ); Thu, 11 Feb 2021 11:21:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231843AbhBKQTT (ORCPT ); Thu, 11 Feb 2021 11:19:19 -0500 Received: from mail-il1-x131.google.com (mail-il1-x131.google.com [IPv6:2607:f8b0:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1392C061794; Thu, 11 Feb 2021 08:18:37 -0800 (PST) Received: by mail-il1-x131.google.com with SMTP id e1so5587860ilu.0; Thu, 11 Feb 2021 08:18:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Xp4N40JfQ3VVDOWjhEqow9AAoJ4Ma4pLuM+YDtd7UgM=; b=mtj2EYF6jZubD9FqRDnVGO9Nzrt3asJMR6eRmNxbiQmeLXJ41KzQgcAiw75aFbcaIO XPth5rq7hMm1y17IJJZ+zMgqgt2YmiL0V+BsYh+gdSQYKEo7E8/3F+aQY0ktGOEqe/px pFbs9oljojdEg3MJTwUVjVE2TMW3nEH6TxWItZ64TK/v+wpK1FAQmHvvamESNccCdmbU FfYnEFQN9BpDwxA70u2lW30+BCL3OtmUpnEzHJGDHc6vgXwrCFRrv5vnFWEBn3Ya8NEH 3e22qb+GPWZDHlWpSBB8NPYsZGPJdtS3opt+wylkai8fTrVcCOsOgHcaaTsEvLssb7Qi AT/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Xp4N40JfQ3VVDOWjhEqow9AAoJ4Ma4pLuM+YDtd7UgM=; b=MDo/e9agMYa9sXfMRgrdmcaQ2OGWL3LltQQAVhES0C2q3CDtvOP0NIktM+oDooEFmj YgumdcgiI9ADxuRevlNzn5j4GjlQLzBg7DODb72++dn1gD9Uz8XqBkoDW0sKIzfCA0ZX BAP5zWe7SdyDJkZTilEDDE3saM6DRCc8xE8QPayHS4k3ZLk1hNaSk6SKYSw5FypOZOY7 h9Zx37m3uJXAmDaK9GcUbLJH/oVNCbfvYA3SHnPHHNnMIrjrZCWxdTLXYutiBVf65aUy bjsB1ReK8XI44T2dYjtOVXSir+BCTZ7tzXInNaIYzdKeBYaYcSJNJLWmWxu8m/eMXzBe dUAw== X-Gm-Message-State: AOAM533gRNyb9HPkL07hI4ZVHq1NmxZ1dcNWbX8TA7lEe7qIyLNehYFv qra1uswVInyLFQlGOvJdgfw= X-Google-Smtp-Source: ABdhPJyiRlMHOsnmLmk554WUf5bF1KkI+XEFPfqpzLjvZdMmtjUIkeHE6mkOmWAVM76TZBe0rVi15w== X-Received: by 2002:a92:c00f:: with SMTP id q15mr6330193ild.62.1613060316991; Thu, 11 Feb 2021 08:18:36 -0800 (PST) Received: from localhost.localdomain ([198.52.185.246]) by smtp.gmail.com with ESMTPSA id d135sm2729913iog.35.2021.02.11.08.18.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Feb 2021 08:18:36 -0800 (PST) From: Sven Van Asbroeck X-Google-Original-From: Sven Van Asbroeck To: Bryan Whitehead , UNGLinuxDriver@microchip.com, David S Miller , Jakub Kicinski Cc: Sven Van Asbroeck , Andrew Lunn , Alexey Denisov , Sergej Bauer , Tim Harvey , =?utf-8?q?Anders_R=C3=B8nn?= =?utf-8?q?ingen?= , Hillf Danton , Christoph Hellwig , Willem de Bruijn , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v2 2/5] lan743x: sync only the received area of an rx ring buffer Date: Thu, 11 Feb 2021 11:18:27 -0500 Message-Id: <20210211161830.17366-3-TheSven73@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210211161830.17366-1-TheSven73@gmail.com> References: <20210211161830.17366-1-TheSven73@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Sven Van Asbroeck On cpu architectures w/o dma cache snooping, dma_unmap() is a is a very expensive operation, because its resulting sync needs to invalidate cpu caches. Increase efficiency/performance by syncing only those sections of the lan743x's rx ring buffers that are actually in use. Signed-off-by: Sven Van Asbroeck --- To: Bryan Whitehead To: UNGLinuxDriver@microchip.com To: "David S. Miller" To: Jakub Kicinski Cc: Andrew Lunn Cc: Alexey Denisov Cc: Sergej Bauer Cc: Tim Harvey Cc: Anders Rønningen Cc: Hillf Danton Cc: Christoph Hellwig Cc: Willem de Bruijn Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org drivers/net/ethernet/microchip/lan743x_main.c | 32 +++++++++++++------ 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index 0c48bb559719..36cc67c72851 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -1968,35 +1968,49 @@ static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index) struct net_device *netdev = rx->adapter->netdev; struct device *dev = &rx->adapter->pdev->dev; struct lan743x_rx_buffer_info *buffer_info; + unsigned int buffer_length, packet_length; struct lan743x_rx_descriptor *descriptor; struct sk_buff *skb; dma_addr_t dma_ptr; - int length; - length = netdev->mtu + ETH_HLEN + 4 + RX_HEAD_PADDING; + buffer_length = netdev->mtu + ETH_HLEN + 4 + RX_HEAD_PADDING; descriptor = &rx->ring_cpu_ptr[index]; buffer_info = &rx->buffer_info[index]; - skb = __netdev_alloc_skb(netdev, length, GFP_ATOMIC | GFP_DMA); + skb = __netdev_alloc_skb(netdev, buffer_length, GFP_ATOMIC | GFP_DMA); if (!skb) return -ENOMEM; - dma_ptr = dma_map_single(dev, skb->data, length, DMA_FROM_DEVICE); + dma_ptr = dma_map_single(dev, skb->data, buffer_length, DMA_FROM_DEVICE); if (dma_mapping_error(dev, dma_ptr)) { dev_kfree_skb_any(skb); return -ENOMEM; } - if (buffer_info->dma_ptr) - dma_unmap_single(dev, buffer_info->dma_ptr, - buffer_info->buffer_length, DMA_FROM_DEVICE); + if (buffer_info->dma_ptr) { + /* unmap from dma */ + packet_length = RX_DESC_DATA0_FRAME_LENGTH_GET_ + (le32_to_cpu(descriptor->data0)); + if (packet_length == 0 || + packet_length > buffer_info->buffer_length) + /* buffer is part of multi-buffer packet: fully used */ + packet_length = buffer_info->buffer_length; + /* sync used part of buffer only */ + dma_sync_single_for_cpu(dev, buffer_info->dma_ptr, + packet_length, + DMA_FROM_DEVICE); + dma_unmap_single_attrs(dev, buffer_info->dma_ptr, + buffer_info->buffer_length, + DMA_FROM_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + } buffer_info->skb = skb; buffer_info->dma_ptr = dma_ptr; - buffer_info->buffer_length = length; + buffer_info->buffer_length = buffer_length; descriptor->data1 = cpu_to_le32(DMA_ADDR_LOW32(buffer_info->dma_ptr)); descriptor->data2 = cpu_to_le32(DMA_ADDR_HIGH32(buffer_info->dma_ptr)); descriptor->data3 = 0; descriptor->data0 = cpu_to_le32((RX_DESC_DATA0_OWN_ | - (length & RX_DESC_DATA0_BUF_LENGTH_MASK_))); + (buffer_length & RX_DESC_DATA0_BUF_LENGTH_MASK_))); lan743x_rx_update_tail(rx, index); return 0;