From patchwork Tue Feb 18 19:50:36 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 13980747 X-Patchwork-Delegate: kuba@kernel.org Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12E0F1EB5E6 for ; Tue, 18 Feb 2025 19:51:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739908268; cv=none; b=Bd7NpvG65vfrrtkSGyGTjr94KPl91SAC/cbp22n++U/YDP5DjX1BLBDNLaQ0DgtLIK/GFHN1VMTDK5nQfK2yWTmpI8tAiievM2AdNlE7+xHjTTZDsVQUteO/z+nHw5EDDm9AeRr8INqTzTfxYtwCZdPqDJSXdHknzTsdPwiPOpw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739908268; c=relaxed/simple; bh=qm85aHAJ3fEWNO0k9VcImWfuicbCKbW9BAl+6MjlbyA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=cOfFCP47RiSFtim8lzz3qGmDNd/ShzLIhHMZSvUZftDxkTEVJk9Hai+focdZ1enVcsxo8XILml1kGCgQP5N/ui/cbX3pAFZ4lTtNHTgWSugx9NmISn38C+oe59o9EA7+PzYH2mmMo4C8pqruzNweSmauIfNWGErpE1ompcRdBMA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=km8mgscc; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="km8mgscc" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1739908252; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Vk8coug+FRo/5jdUZgRpW7dUVKkTDmTjAi05VADtXHc=; b=km8mgsccdl4aUB+LLwGy+ZUpUnhPFBvZQVo+FlhnXIBQS+NdfRdBKEIQu8f2At2QX6JYtL YB3ZQwfVQnp71lR4xTMgCI/ImAawzp7w1+PWcKznFyVt3bc6V2XTmnNRv5GMdtJOictbJj 5ERD9JSQ36XR3CITfPFj+Re0hQliRV4= From: Sean Anderson To: Nicolas Ferre , Claudiu Beznea , netdev@vger.kernel.org Cc: Eric Dumazet , Paolo Abeni , linux-kernel@vger.kernel.org, "David S . Miller" , Andrew Lunn , Jakub Kicinski , Sean Anderson Subject: [PATCH net] net: cadence: macb: Synchronize stats calculations Date: Tue, 18 Feb 2025 14:50:36 -0500 Message-Id: <20250218195036.37137-1-sean.anderson@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: kuba@kernel.org Stats calculations involve a RMW to add the stat update to the existing value. This is currently not protected by any synchronization mechanism, so data races are possible. Add a spinlock to protect the update. The reader side could be protected using u64_stats, but we would still need a spinlock for the update side anyway. And we always do an update immediately before reading the stats anyway. Fixes: 89e5785fc8a6 ("[PATCH] Atmel MACB ethernet driver") Signed-off-by: Sean Anderson --- drivers/net/ethernet/cadence/macb.h | 2 ++ drivers/net/ethernet/cadence/macb_main.c | 12 ++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h index 5740c98d8c9f..2847278d9cd4 100644 --- a/drivers/net/ethernet/cadence/macb.h +++ b/drivers/net/ethernet/cadence/macb.h @@ -1279,6 +1279,8 @@ struct macb { struct clk *rx_clk; struct clk *tsu_clk; struct net_device *dev; + /* Protects hw_stats and ethtool_stats */ + spinlock_t stats_lock; union { struct macb_stats macb; struct gem_stats gem; diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 48496209fb16..990a3863c6e1 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -1978,10 +1978,12 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id) if (status & MACB_BIT(ISR_ROVR)) { /* We missed at least one packet */ + spin_lock(&bp->stats_lock); if (macb_is_gem(bp)) bp->hw_stats.gem.rx_overruns++; else bp->hw_stats.macb.rx_overruns++; + spin_unlock(&bp->stats_lock); if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) queue_writel(queue, ISR, MACB_BIT(ISR_ROVR)); @@ -3102,6 +3104,7 @@ static struct net_device_stats *gem_get_stats(struct macb *bp) if (!netif_running(bp->dev)) return nstat; + spin_lock(&bp->stats_lock); gem_update_stats(bp); nstat->rx_errors = (hwstat->rx_frame_check_sequence_errors + @@ -3131,6 +3134,7 @@ static struct net_device_stats *gem_get_stats(struct macb *bp) nstat->tx_aborted_errors = hwstat->tx_excessive_collisions; nstat->tx_carrier_errors = hwstat->tx_carrier_sense_errors; nstat->tx_fifo_errors = hwstat->tx_underrun; + spin_unlock(&bp->stats_lock); return nstat; } @@ -3138,12 +3142,13 @@ static struct net_device_stats *gem_get_stats(struct macb *bp) static void gem_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 *data) { - struct macb *bp; + struct macb *bp = netdev_priv(dev); - bp = netdev_priv(dev); + spin_lock(&bp->stats_lock); gem_update_stats(bp); memcpy(data, &bp->ethtool_stats, sizeof(u64) * (GEM_STATS_LEN + QUEUE_STATS_LEN * MACB_MAX_QUEUES)); + spin_unlock(&bp->stats_lock); } static int gem_get_sset_count(struct net_device *dev, int sset) @@ -3193,6 +3198,7 @@ static struct net_device_stats *macb_get_stats(struct net_device *dev) return gem_get_stats(bp); /* read stats from hardware */ + spin_lock(&bp->stats_lock); macb_update_stats(bp); /* Convert HW stats into netdevice stats */ @@ -3226,6 +3232,7 @@ static struct net_device_stats *macb_get_stats(struct net_device *dev) nstat->tx_carrier_errors = hwstat->tx_carrier_errors; nstat->tx_fifo_errors = hwstat->tx_underruns; /* Don't know about heartbeat or window errors... */ + spin_unlock(&bp->stats_lock); return nstat; } @@ -5097,6 +5104,7 @@ static int macb_probe(struct platform_device *pdev) } } spin_lock_init(&bp->lock); + spin_lock_init(&bp->stats_lock); /* setup capabilities */ macb_configure_caps(bp, macb_config);