From patchwork Tue Mar 24 13:23:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 11455395 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 38FB0913 for ; Tue, 24 Mar 2020 13:25:48 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F3B7320870 for ; Tue, 24 Mar 2020 13:25:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QO8l6req" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3B7320870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=bSWheouvT2Fd+jSkIptoL1f+/ZvPNYt4JfmL7b3ltIs=; b=QO8l6reqBErKIA/yYKJA+UTpzZ kWfUyhxyLWEC/4rwrlx6DgzYCDnxogH+JX0vUVSfEycnetGBjDhw0CXEiEGowm5rBwQvcOO+41jNY ddcXsC4jP6xZQmnqzSgWQvtZGkLu9vf4EpAHIhKs1r6MYpr+SX140C3ZDuX2xZ36QxmyMpKGXftQk f05OuzES4nki5g16+CcHgk5E9mHTKxSUx6fU5Sgkl/LEz0+ewMWLDDncmYRFI/pvvOJxScwVqqJTr ZX6YFSdMnZixB5Mfy4AD/mrqH1fQ9UzWxlGEZEwHnoBH2FV8bLZv+a34ofelcqDjHi07GUoaonnvt +VVTaWIw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGjYq-0003Y5-8x; Tue, 24 Mar 2020 13:25:40 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGjXI-0000vj-05 for linux-arm-kernel@lists.infradead.org; Tue, 24 Mar 2020 13:24:05 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 856761FB; Tue, 24 Mar 2020 06:24:03 -0700 (PDT) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.197.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 35E5C3F52E; Tue, 24 Mar 2020 06:24:02 -0700 (PDT) From: Andre Przywara To: "David S . Miller" , Radhey Shyam Pandey Subject: [PATCH v3 06/14] net: axienet: Factor out TX descriptor chain cleanup Date: Tue, 24 Mar 2020 13:23:39 +0000 Message-Id: <20200324132347.23709-7-andre.przywara@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324132347.23709-1-andre.przywara@arm.com> References: <20200324132347.23709-1-andre.przywara@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200324_062404_131036_039F677E X-CRM114-Status: GOOD ( 15.42 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Lunn , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Simek , Robert Hancock , Russell King , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Factor out the code that cleans up a number of connected TX descriptors, as we will need it to properly roll back a failed _xmit() call. There are subtle differences between cleaning up a successfully sent chain (unknown number of involved descriptors, total data size needed) and a chain that was about to set up (number of descriptors known), so cater for those variations with some extra parameters. Signed-off-by: Andre Przywara Reviewed-by: Radhey Shyam Pandey --- .../net/ethernet/xilinx/xilinx_axienet_main.c | 79 +++++++++++++------ 1 file changed, 57 insertions(+), 22 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 82ec7deacdfe..5c1b53944771 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -545,32 +545,46 @@ static int axienet_device_reset(struct net_device *ndev) } /** - * axienet_start_xmit_done - Invoked once a transmit is completed by the - * Axi DMA Tx channel. + * axienet_free_tx_chain - Clean up a series of linked TX descriptors. * @ndev: Pointer to the net_device structure + * @first_bd: Index of first descriptor to clean up + * @nr_bds: Number of descriptors to clean up, can be -1 if unknown. + * @sizep: Pointer to a u32 filled with the total sum of all bytes + * in all cleaned-up descriptors. Ignored if NULL. * - * This function is invoked from the Axi DMA Tx isr to notify the completion - * of transmit operation. It clears fields in the corresponding Tx BDs and - * unmaps the corresponding buffer so that CPU can regain ownership of the - * buffer. It finally invokes "netif_wake_queue" to restart transmission if - * required. + * Would either be called after a successful transmit operation, or after + * there was an error when setting up the chain. + * Returns the number of descriptors handled. */ -static void axienet_start_xmit_done(struct net_device *ndev) +static int axienet_free_tx_chain(struct net_device *ndev, u32 first_bd, + int nr_bds, u32 *sizep) { - u32 size = 0; - u32 packets = 0; struct axienet_local *lp = netdev_priv(ndev); struct axidma_bd *cur_p; - unsigned int status = 0; + int max_bds = nr_bds; + unsigned int status; + int i; + + if (max_bds == -1) + max_bds = lp->tx_bd_num; + + for (i = 0; i < max_bds; i++) { + cur_p = &lp->tx_bd_v[(first_bd + i) % lp->tx_bd_num]; + status = cur_p->status; + + /* If no number is given, clean up *all* descriptors that have + * been completed by the MAC. + */ + if (nr_bds == -1 && !(status & XAXIDMA_BD_STS_COMPLETE_MASK)) + break; - cur_p = &lp->tx_bd_v[lp->tx_bd_ci]; - status = cur_p->status; - while (status & XAXIDMA_BD_STS_COMPLETE_MASK) { dma_unmap_single(ndev->dev.parent, cur_p->phys, (cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK), DMA_TO_DEVICE); - if (cur_p->skb) + + if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK)) dev_consume_skb_irq(cur_p->skb); + cur_p->cntrl = 0; cur_p->app0 = 0; cur_p->app1 = 0; @@ -579,15 +593,36 @@ static void axienet_start_xmit_done(struct net_device *ndev) cur_p->status = 0; cur_p->skb = NULL; - size += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK; - packets++; - - if (++lp->tx_bd_ci >= lp->tx_bd_num) - lp->tx_bd_ci = 0; - cur_p = &lp->tx_bd_v[lp->tx_bd_ci]; - status = cur_p->status; + if (sizep) + *sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK; } + return i; +} + +/** + * axienet_start_xmit_done - Invoked once a transmit is completed by the + * Axi DMA Tx channel. + * @ndev: Pointer to the net_device structure + * + * This function is invoked from the Axi DMA Tx isr to notify the completion + * of transmit operation. It clears fields in the corresponding Tx BDs and + * unmaps the corresponding buffer so that CPU can regain ownership of the + * buffer. It finally invokes "netif_wake_queue" to restart transmission if + * required. + */ +static void axienet_start_xmit_done(struct net_device *ndev) +{ + struct axienet_local *lp = netdev_priv(ndev); + u32 packets = 0; + u32 size = 0; + + packets = axienet_free_tx_chain(ndev, lp->tx_bd_ci, -1, &size); + + lp->tx_bd_ci += packets; + if (lp->tx_bd_ci >= lp->tx_bd_num) + lp->tx_bd_ci -= lp->tx_bd_num; + ndev->stats.tx_packets += packets; ndev->stats.tx_bytes += size;