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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD299C433EF for ; Mon, 20 Dec 2021 15:16:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238265AbhLTPQj (ORCPT ); Mon, 20 Dec 2021 10:16:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239952AbhLTPOh (ORCPT ); Mon, 20 Dec 2021 10:14:37 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7A62C0D9417; Mon, 20 Dec 2021 06:57:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 86670B80ED3; Mon, 20 Dec 2021 14:57:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C69CFC36AE7; Mon, 20 Dec 2021 14:57:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640012262; bh=xbO4QFGmvtWeSuF+fO5XQC/Wbxj+WtjB5c1Bob2p6uw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QqhVx+juU2CAtBdmpL3DzQIGnedc3RrFUXqwNFgsi0MN4mOh1j645mNhTX8EEj89S Omttksmq+qeWivCLKsg2wk0sncpk0Sf4FdInRehVnJh7qe42URDvNODDmLXEW8lMOp aMd5ujzezi551ZgQnLW0b/LlWjbsOjo6SKdLIBQU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Fainelli , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 106/177] net: systemport: Add global locking for descriptor lifecycle Date: Mon, 20 Dec 2021 15:34:16 +0100 Message-Id: <20211220143043.652792885@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211220143040.058287525@linuxfoundation.org> References: <20211220143040.058287525@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Fainelli [ Upstream commit 8b8e6e782456f1ce02a7ae914bbd5b1053f0b034 ] The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used. Fixes: 80105befdb4b ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver") Signed-off-by: Florian Fainelli Link: https://lore.kernel.org/r/20211215202450.4086240-1-f.fainelli@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/broadcom/bcmsysport.c | 5 ++++- drivers/net/ethernet/broadcom/bcmsysport.h | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 7fa1b695400d7..0877b3d7f88c5 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -1309,11 +1309,11 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, struct bcm_sysport_priv *priv = netdev_priv(dev); struct device *kdev = &priv->pdev->dev; struct bcm_sysport_tx_ring *ring; + unsigned long flags, desc_flags; struct bcm_sysport_cb *cb; struct netdev_queue *txq; u32 len_status, addr_lo; unsigned int skb_len; - unsigned long flags; dma_addr_t mapping; u16 queue; int ret; @@ -1373,8 +1373,10 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, ring->desc_count--; /* Ports are latched, so write upper address first */ + spin_lock_irqsave(&priv->desc_lock, desc_flags); tdma_writel(priv, len_status, TDMA_WRITE_PORT_HI(ring->index)); tdma_writel(priv, addr_lo, TDMA_WRITE_PORT_LO(ring->index)); + spin_unlock_irqrestore(&priv->desc_lock, desc_flags); /* Check ring space and update SW control flow */ if (ring->desc_count == 0) @@ -2013,6 +2015,7 @@ static int bcm_sysport_open(struct net_device *dev) } /* Initialize both hardware and software ring */ + spin_lock_init(&priv->desc_lock); for (i = 0; i < dev->num_tx_queues; i++) { ret = bcm_sysport_init_tx_ring(priv, i); if (ret) { diff --git a/drivers/net/ethernet/broadcom/bcmsysport.h b/drivers/net/ethernet/broadcom/bcmsysport.h index 984f76e74b43e..16b73bb9acc78 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.h +++ b/drivers/net/ethernet/broadcom/bcmsysport.h @@ -711,6 +711,7 @@ struct bcm_sysport_priv { int wol_irq; /* Transmit rings */ + spinlock_t desc_lock; struct bcm_sysport_tx_ring *tx_rings; /* Receive queue */ -- 2.33.0