From patchwork Tue Feb 16 01:08:03 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: 383675 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 EECACC433E6 for ; Tue, 16 Feb 2021 01:09:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB64364DF0 for ; Tue, 16 Feb 2021 01:09:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229916AbhBPBJJ (ORCPT ); Mon, 15 Feb 2021 20:09:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229864AbhBPBIz (ORCPT ); Mon, 15 Feb 2021 20:08:55 -0500 Received: from mail-qk1-x731.google.com (mail-qk1-x731.google.com [IPv6:2607:f8b0:4864:20::731]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46FDAC061756; Mon, 15 Feb 2021 17:08:15 -0800 (PST) Received: by mail-qk1-x731.google.com with SMTP id b14so8150263qkk.0; Mon, 15 Feb 2021 17:08:15 -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=zThIAGZwfvSkO7xnU4EZjlS525haOLyjxSDrptoIMpw=; b=ZZALdmcMkWw1hcaIKpLQZWaSVdXNuz9dyztRAKl+KLZ5rixd+wbe4HtlLeSAgZn32E uGHA0DCPmbCdCozANeHzCjwk2B/kb7QNKTTXVCUOsT+oyJYj7eq3CCjZ+QlnBj5L+Ir9 IhtHwQFcuXDuXcv4JbktcrLGviVdJMnnJrNu2nygqVH/OJE5beul9wdYKGMZOYF6LIUF CFvJnLbwIUtXUkqy8FDLanbW/3XzdY3E6X9u/9EZlzc75zpDvsg90Z7qp1ScPNhcN5k6 Lh3usx4iNXRe+oEMvSQOrme7X7IAzkoGsGRvhgFBsEhgRGdQgOvuPv6eaeyJJpGGmMb4 2zfA== 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=zThIAGZwfvSkO7xnU4EZjlS525haOLyjxSDrptoIMpw=; b=kL8/2eUTVvqbEoR3MdlW3O10OL80UN0aRr4FwvKbXPKhCQWLwFYQyhXFTCsnQ/yDNM QVr70phFtBHbnovUWL+TurP9iIUsmCnb+rCoxZ7+/aKL1TMECeNvG9WW6VxAQn1M+cWg 3RjPq2Rj1iIUs3jOddvUJAJ+NzLVVu2s8l37Ur2OXzhUcYbZs0cwRhO7G4QZHPfZM44L 61rp9zXcfT5A58TPsd0FdnlzJjiFJfarOJFpAXiH7KERcTyktZNT5aAs2g3qLmSpAs3e OgbxtqUzEfq+2Gl8Hc6fgk8rgdK5U8sHiYdCK+G4YmEFuIW1PfbVe5aH8+jwC7dUraO3 gdTw== X-Gm-Message-State: AOAM530kfMefVJzx8JXY9OfXjXb7Ca8vYgJnWE/sjinF89Uld3Vfv7mp yilJJrJQ7HXtgNLXIbT0NGU= X-Google-Smtp-Source: ABdhPJzj3OXkVjSjHDwg/MhJg/fEidoXM8lI5uDWlrn/LErZV87u7DQzsn2ohwz+1rYxbfAUP1Kvhw== X-Received: by 2002:a05:620a:158c:: with SMTP id d12mr6169273qkk.147.1613437694269; Mon, 15 Feb 2021 17:08:14 -0800 (PST) Received: from localhost.localdomain ([198.52.185.246]) by smtp.gmail.com with ESMTPSA id b20sm508830qto.45.2021.02.15.17.08.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Feb 2021 17:08:13 -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 v3 2/5] lan743x: sync only the received area of an rx ring buffer Date: Mon, 15 Feb 2021 20:08:03 -0500 Message-Id: <20210216010806.31948-3-TheSven73@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210216010806.31948-1-TheSven73@gmail.com> References: <20210216010806.31948-1-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 | 35 ++++++++++++++----- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index c2633efe6067..6b642691a676 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -1968,35 +1968,52 @@ 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, used_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) { + /* sync used area of buffer only */ + if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_LS_) + /* frame length is valid only if LS bit is set. + * it's a safe upper bound for the used area in this + * buffer. + */ + used_length = min(RX_DESC_DATA0_FRAME_LENGTH_GET_ + (le32_to_cpu(descriptor->data0)), + buffer_info->buffer_length); + else + used_length = buffer_info->buffer_length; + dma_sync_single_for_cpu(dev, buffer_info->dma_ptr, + used_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;