From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 C0A8E37F8D3 for ; Fri, 10 Apr 2026 19:52:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775850764; cv=none; b=qhJj4CWMCiCQDbQzCm/3XCaGJGlBE5fIc1JDSpgzIZdSVZ1y4nYFvAaJSKw6okQVFCMim/3e11PQqSwZNwypTN2aMGKA+OAcC/lLatpZpk87iUgROMHCSPgKf9uWgWVFYT8Rgw49w5WMmz+6z4eiCHi0s4J0O43CV+l2VwfdpJk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775850764; c=relaxed/simple; bh=ylFosOyISRkCLcpLILfXR1jqq9ZJDl5D3Rd67XbsIZk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PeWzTIu06Atyv21/CfJnvQ9DerRoVW1qV22JeQAKes2jyrTmKEOXEby96kQXfRTzf1wKfojW/CoiXykU/ENWQ2WXgcRYI7M/PyKkRuz6PACrGuKXAJV/ZbzOTrB/DOWR1EwtcMr7pFsGBehW9SZxPwe/sRDH60ku5csme/8J/5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=ydQXnl7D; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="ydQXnl7D" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 9D7FF4E4294C; Fri, 10 Apr 2026 19:52:41 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 73708603F0; Fri, 10 Apr 2026 19:52:41 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id B2A6610450088; Fri, 10 Apr 2026 21:52:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1775850760; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=lvkMSS621GEt/FKfEI0QkYcsjQ+tlBiP5wmcPdsLGHE=; b=ydQXnl7DlcIUY4Zej6P4WopdUL83zZvP8IIsLJNa9mf3BKSdrcbu61xMIdYGBbbMP4C1g9 GaUWV4OwwR64gJ/RlT1Rnnjm3AOlNsnCHgmGGlG8uSi5FH/wjEdiuGZFL7sHKdGUl0rTpE e9blU3auiCN09fz7LzJC7HOPx+V/yXUwSWAUGPAjoFuQ4naraFFZ6p393Fg7ZHWKKgQFiw Aopajuh5UWcM0jclega8tfAndMfWV4EvRff0Q2VJ4lZhW39P4Vo+FWKnDUCDnbCjtIA7UU zlmGtsss5pytqyCe9H/IMiP+nqlU5qDsa8HlI4Hpe3co8qalDJmwFg70M2/lDg== From: =?utf-8?q?Th=C3=A9o_Lebrun?= Date: Fri, 10 Apr 2026 21:52:01 +0200 Subject: [PATCH net-next v2 13/14] net: macb: use context swapping in .set_ringparam() Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260410-macb-context-v2-13-af39f71d40b6@bootlin.com> References: <20260410-macb-context-v2-0-af39f71d40b6@bootlin.com> In-Reply-To: <20260410-macb-context-v2-0-af39f71d40b6@bootlin.com> To: Nicolas Ferre , Claudiu Beznea , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Richard Cochran , Russell King Cc: Paolo Valerio , Conor Dooley , Nicolai Buchwitz , Vladimir Kondratiev , Gregory CLEMENT , =?utf-8?q?Beno=C3=AEt_Monin?= , Tawfik Bayouk , Thomas Petazzoni , Maxime Chevallier , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Th=C3=A9o_Lebrun?= X-Mailer: b4 0.15.1 X-Last-TLS-Session-Version: TLSv1.3 ethtool_ops.set_ringparam() is implemented using the primitive close / update ring size / reopen sequence. Under memory pressure this does not fly: we free our buffers at close and cannot reallocate new ones at open. Also, it triggers a slow PHY reinit. Instead, exploit the new context mechanism and improve our sequence to: - allocate a new context (including buffers) first - if it fails, early return without any impact to the interface - stop interface - update global state (bp, netdev, etc) - pass buffer pointers to the hardware - start interface - free old context. The HW disable sequence is inspired by macb_reset_hw() but avoids (1) setting NCR bit CLRSTAT and (2) clearing register PBUFRXCUT. The HW re-enable sequence is inspired by macb_mac_link_up(), skipping over register writes which would be redundant (because values have not changed). The generic context swapping parts are isolated into helper functions macb_context_swap_start|end(), reusable by other operations (change_mtu, set_channels, etc). Signed-off-by: Théo Lebrun --- drivers/net/ethernet/cadence/macb_main.c | 102 ++++++++++++++++++++++++++++--- 1 file changed, 95 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 81beb67b206a..340ae7d881c6 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -3081,6 +3081,89 @@ static void macb_configure_dma(struct macb *bp) } } +static void macb_context_swap_start(struct macb *bp) +{ + struct macb_queue *queue; + unsigned long flags; + unsigned int q; + u32 ctrl; + + /* Disable software Tx, disable HW Tx/Rx and disable NAPI. */ + + netif_tx_disable(bp->netdev); + + spin_lock_irqsave(&bp->lock, flags); + + ctrl = macb_readl(bp, NCR); + macb_writel(bp, NCR, ctrl & ~(MACB_BIT(RE) | MACB_BIT(TE))); + + macb_writel(bp, TSR, -1); + macb_writel(bp, RSR, -1); + + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { + queue_writel(queue, IDR, -1); + queue_readl(queue, ISR); + if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) + queue_writel(queue, ISR, -1); + } + + spin_unlock_irqrestore(&bp->lock, flags); + + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { + napi_disable(&queue->napi_rx); + napi_disable(&queue->napi_tx); + netdev_tx_reset_queue(netdev_get_tx_queue(bp->netdev, q)); + cancel_work_sync(&queue->tx_error_task); + } + + cancel_work_sync(&bp->hresp_err_bh_work); + cancel_delayed_work_sync(&bp->tx_lpi_work); +} + +static void macb_context_swap_end(struct macb *bp, + struct macb_context *new_ctx) +{ + struct macb_context *old_ctx; + struct macb_queue *queue; + unsigned int q; + u32 ctrl; + + /* Swap contexts & give buffer pointers to HW. */ + + old_ctx = bp->ctx; + bp->ctx = new_ctx; + macb_init_buffers(bp); + + /* Start NAPI, HW Tx/Rx and software Tx. */ + + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { + napi_enable(&queue->napi_rx); + napi_enable(&queue->napi_tx); + } + + macb_configure_dma(bp); + + if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC)) { + for (q = 0, queue = bp->queues; q < bp->num_queues; + ++q, ++queue) { + queue_writel(queue, IER, + bp->rx_intr_mask | + MACB_TX_INT_FLAGS | + MACB_BIT(HRESP)); + } + } + + ctrl = macb_readl(bp, NCR); + macb_writel(bp, NCR, ctrl | MACB_BIT(RE) | MACB_BIT(TE)); + + netif_tx_start_all_queues(bp->netdev); + + /* Free old context. */ + + macb_free_consistent(old_ctx); + kfree(old_ctx); +} + static void macb_init_hw(struct macb *bp) { u32 config; @@ -3804,9 +3887,10 @@ static int macb_set_ringparam(struct net_device *netdev, struct kernel_ethtool_ringparam *kernel_ring, struct netlink_ext_ack *extack) { + unsigned int new_rx_size, new_tx_size; struct macb *bp = netdev_priv(netdev); - u32 new_rx_size, new_tx_size; - unsigned int reset = 0; + bool running = netif_running(netdev); + struct macb_context *new_ctx; if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending)) return -EINVAL; @@ -3825,16 +3909,20 @@ static int macb_set_ringparam(struct net_device *netdev, return 0; } - if (netif_running(bp->netdev)) { - reset = 1; - macb_close(bp->netdev); + if (running) { + new_ctx = macb_context_alloc(bp, netdev->mtu, + new_rx_size, new_tx_size); + if (IS_ERR(new_ctx)) + return PTR_ERR(new_ctx); + + macb_context_swap_start(bp); } bp->configured_rx_ring_size = new_rx_size; bp->configured_tx_ring_size = new_tx_size; - if (reset) - macb_open(bp->netdev); + if (running) + macb_context_swap_end(bp, new_ctx); return 0; } -- 2.53.0