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=-15.8 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,USER_AGENT_GIT autolearn=unavailable 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 78C34C43461 for ; Fri, 23 Apr 2021 01:49:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5838861458 for ; Fri, 23 Apr 2021 01:49:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240773AbhDWBtn (ORCPT ); Thu, 22 Apr 2021 21:49:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240408AbhDWBtA (ORCPT ); Thu, 22 Apr 2021 21:49:00 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ABAAC06138E; Thu, 22 Apr 2021 18:48:13 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id r12so71623144ejr.5; Thu, 22 Apr 2021 18:48:13 -0700 (PDT) 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=lAG/o0OGYJIRUzC/3iPfA0VGTvJTckfhIeXmdYy8D7s=; b=hP2RhnO2AfBseuJQQrTryszUEBwW99L+V55epRVWN5clVCRfFKOrwkqfJw7a79M/KC ZzEtKZXwaQRJwMDK4jCjP6QpbkBFhPIz3V+a5NX900DkCNMdOmCxF5gF6u/eLy25b+FY pJqdoBAPgrUskY89PmbCOQAAjA+P+kbuIdZSW2MGKSL5Xmg/ZN5xS1mDmHPfE2WZRc3t dAIjRtwZYsRTXy3zvgJ5mzZnGZdOFa/bdmcpYhKcPu/NtXLyteKv8CX4Bn28JnbMXydd tk60VxFeDNY0hARjNRYB7K+7dtkWGqIMYkR97N/ZXegaJrLYv8PlvdTCNNtHBukp7KvT Pg7A== 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=lAG/o0OGYJIRUzC/3iPfA0VGTvJTckfhIeXmdYy8D7s=; b=PQEJn7ZDwIataTHUIplXWor8KtmMO43nASq5s+CWhO8nPVsc7Yrv+5oJ/9LHVB7Tch x+B/pOtzwxlcA8LxxLSvheaMgTqq8ToqyPLv81xwsbtxjtFSJlH/KDwPyY85kfhRug2r YccZbmNwgU3YbaOgXZq8u3clx74zdCh83qgWtIMsGAJlyhu1FCWUh69ByV6lbyoHoxUz TJs1ww2iyJBkQDgwY29q+bcwISddIHTYDV9e5sewkoiloiQGPrlu/j4ZaRPlJl9pUvKq F4othPAf2yJSvWRjMWUBNlM6cDtdGyHZmR6UeC6jP1hY2DhccY5dtkMZF0WDIXWo+ptG z0xQ== X-Gm-Message-State: AOAM5309qxBu177P1Y8BcHE2D8Q6FWikNbMDV6EK5axoShvO9vNuUmqp obkqGgve2ifwK/a53vbsNgKktWH4DkRe6Q== X-Google-Smtp-Source: ABdhPJyxJI5kZhM/we67BpwL9wm0tcCVEwsQ9EccqVB6j6qo/2+n6eBWSBmwdgKWrgRQEXbv83xjHw== X-Received: by 2002:a17:906:c44f:: with SMTP id ck15mr1564008ejb.269.1619142491920; Thu, 22 Apr 2021 18:48:11 -0700 (PDT) Received: from Ansuel-xps.localdomain (93-35-189-2.ip56.fastwebnet.it. [93.35.189.2]) by smtp.googlemail.com with ESMTPSA id t4sm3408635edd.6.2021.04.22.18.48.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Apr 2021 18:48:11 -0700 (PDT) From: Ansuel Smith To: Florian Fainelli Cc: Ansuel Smith , Andrew Lunn , Vivien Didelot , Vladimir Oltean , "David S. Miller" , Jakub Kicinski , Rob Herring , Heiner Kallweit , Russell King , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 13/14] drivers: net: dsa: qca8k: protect MASTER busy_wait with mdio mutex Date: Fri, 23 Apr 2021 03:47:39 +0200 Message-Id: <20210423014741.11858-14-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210423014741.11858-1-ansuelsmth@gmail.com> References: <20210423014741.11858-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org MDIO_MASTER operation have a dedicated busy wait that is not protected by the mdio mutex. This can cause situation where the MASTER operation is done and a normal operation is executed between the MASTER read/write and the MASTER busy_wait. Rework the qca8k_mdio_read/write function to address this issue by binding the lock for the whole MASTER operation and not only the mdio read/write common operation. Signed-off-by: Ansuel Smith --- drivers/net/dsa/qca8k.c | 59 ++++++++++++++++++++++++++++++++++------- 1 file changed, 50 insertions(+), 9 deletions(-) diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c index 88a0234f1a7b..d2f5e0b1c721 100644 --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -609,9 +609,33 @@ qca8k_port_to_phy(int port) return port - 1; } +static int +qca8k_mdio_busy_wait(struct qca8k_priv *priv, u32 reg, u32 mask) +{ + unsigned long timeout; + u16 r1, r2, page; + + qca8k_split_addr(reg, &r1, &r2, &page); + + timeout = jiffies + msecs_to_jiffies(20); + + /* loop until the busy flag has cleared */ + do { + u32 val = qca8k_mii_read32(priv->bus, 0x10 | r2, r1); + int busy = val & mask; + + if (!busy) + break; + cond_resched(); + } while (!time_after_eq(jiffies, timeout)); + + return time_after_eq(jiffies, timeout); +} + static int qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data) { + u16 r1, r2, page; u32 phy, val; int ret; @@ -627,10 +651,17 @@ qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data) QCA8K_MDIO_MASTER_REG_ADDR(regnum) | QCA8K_MDIO_MASTER_DATA(data); - qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val); + qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page); + + mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED); + + qca8k_set_page(priv->bus, page); + qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val); - ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, - QCA8K_MDIO_MASTER_BUSY); + ret = qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, + QCA8K_MDIO_MASTER_BUSY); + + mutex_unlock(&priv->bus->mdio_lock); qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL, QCA8K_MDIO_MASTER_EN); @@ -641,6 +672,7 @@ qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data) static int qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum) { + u16 r1, r2, page; u32 phy, val; if (regnum >= QCA8K_MDIO_MASTER_MAX_REG) @@ -654,14 +686,23 @@ qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum) QCA8K_MDIO_MASTER_READ | QCA8K_MDIO_MASTER_PHY_ADDR(phy) | QCA8K_MDIO_MASTER_REG_ADDR(regnum); - qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val); + qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page); - if (qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, - QCA8K_MDIO_MASTER_BUSY)) - return -ETIMEDOUT; + mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED); + + qca8k_set_page(priv->bus, page); + qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val); + + if (qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL, + QCA8K_MDIO_MASTER_BUSY)) + val = -ETIMEDOUT; + else + val = qca8k_mii_read32(priv->bus, 0x10 | r2, r1); + + mutex_unlock(&priv->bus->mdio_lock); - val = (qca8k_read(priv, QCA8K_MDIO_MASTER_CTRL) & - QCA8K_MDIO_MASTER_DATA_MASK); + if (val >= 0) + val &= QCA8K_MDIO_MASTER_DATA_MASK; qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL, QCA8K_MDIO_MASTER_EN); -- 2.30.2