From patchwork Wed Nov 3 09:19:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?Q2zDqW1lbnQgTMOpZ2Vy?= X-Patchwork-Id: 12600465 X-Patchwork-Delegate: kuba@kernel.org 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 339E9C433F5 for ; Wed, 3 Nov 2021 09:20:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F7A961101 for ; Wed, 3 Nov 2021 09:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232258AbhKCJX0 (ORCPT ); Wed, 3 Nov 2021 05:23:26 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:51849 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232113AbhKCJXK (ORCPT ); Wed, 3 Nov 2021 05:23:10 -0400 Received: (Authenticated sender: clement.leger@bootlin.com) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 0FDD9100002; Wed, 3 Nov 2021 09:20:31 +0000 (UTC) From: =?utf-8?b?Q2zDqW1lbnQgTMOpZ2Vy?= To: "David S. Miller" , Jakub Kicinski , Rob Herring , Vladimir Oltean , Claudiu Manoil , Alexandre Belloni , UNGLinuxDriver@microchip.com, Andrew Lunn Cc: =?utf-8?b?Q2zDqW1lbnQgTMOpZ2Vy?= , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Petazzoni Subject: [PATCH v2 6/6] net: ocelot: add jumbo frame support for FDMA Date: Wed, 3 Nov 2021 10:19:43 +0100 Message-Id: <20211103091943.3878621-7-clement.leger@bootlin.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211103091943.3878621-1-clement.leger@bootlin.com> References: <20211103091943.3878621-1-clement.leger@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org When using the FDMA, using jumbo frames can lead to a large performance improvement. When changing the MTU, the RX buffer size must be increased to be large enough to receive jumbo frame. Since the FDMA is shared amongst all interfaces, all the ports must be down before changing the MTU. Buffers are sized to accept the maximum MTU supported by each port. Signed-off-by: Clément Léger --- drivers/net/ethernet/mscc/ocelot_fdma.c | 61 +++++++++++++++++++++++++ drivers/net/ethernet/mscc/ocelot_fdma.h | 1 + drivers/net/ethernet/mscc/ocelot_net.c | 7 +++ 3 files changed, 69 insertions(+) diff --git a/drivers/net/ethernet/mscc/ocelot_fdma.c b/drivers/net/ethernet/mscc/ocelot_fdma.c index d8cdf022bbee..bee1a310caa6 100644 --- a/drivers/net/ethernet/mscc/ocelot_fdma.c +++ b/drivers/net/ethernet/mscc/ocelot_fdma.c @@ -530,6 +530,67 @@ static void fdma_free_skbs_list(struct ocelot_fdma *fdma, } } +int ocelot_fdma_change_mtu(struct net_device *dev, int new_mtu) +{ + struct ocelot_port_private *priv = netdev_priv(dev); + struct ocelot_port *port = &priv->port; + struct ocelot *ocelot = port->ocelot; + struct ocelot_fdma *fdma = ocelot->fdma; + struct ocelot_fdma_dcb *dcb, *dcb_temp; + struct list_head tmp = LIST_HEAD_INIT(tmp); + size_t old_rx_buf_size = fdma->rx_buf_size; + bool all_ports_down = true; + u8 port_num; + + /* The FDMA RX list is shared amongst all the port, get the max MTU from + * all of them + */ + for (port_num = 0; port_num < ocelot->num_phys_ports; port_num++) { + port = ocelot->ports[port_num]; + if (!port) + continue; + + priv = container_of(port, struct ocelot_port_private, port); + + if (READ_ONCE(priv->dev->mtu) > new_mtu) + new_mtu = READ_ONCE(priv->dev->mtu); + + /* All ports must be down to change the RX buffer length */ + if (netif_running(priv->dev)) + all_ports_down = false; + } + + fdma->rx_buf_size = fdma_rx_compute_buffer_size(new_mtu); + if (fdma->rx_buf_size == old_rx_buf_size) + return 0; + + if (!all_ports_down) + return -EBUSY; + + priv = netdev_priv(dev); + + fdma_stop_channel(fdma, MSCC_FDMA_INJ_CHAN); + + /* Discard all pending RX software and hardware descriptor */ + fdma_free_skbs_list(fdma, &fdma->rx_hw, DMA_FROM_DEVICE); + fdma_free_skbs_list(fdma, &fdma->rx_sw, DMA_FROM_DEVICE); + + /* Move all DCBs to a temporary list that will be injected in sw list */ + if (!list_empty(&fdma->rx_hw)) + list_splice_tail_init(&fdma->rx_hw, &tmp); + if (!list_empty(&fdma->rx_sw)) + list_splice_tail_init(&fdma->rx_sw, &tmp); + + list_for_each_entry_safe(dcb, dcb_temp, &tmp, node) { + list_del(&dcb->node); + ocelot_fdma_rx_add_dcb_sw(fdma, dcb); + } + + ocelot_fdma_rx_refill(fdma); + + return 0; +} + static int fdma_init_tx(struct ocelot_fdma *fdma) { int i; diff --git a/drivers/net/ethernet/mscc/ocelot_fdma.h b/drivers/net/ethernet/mscc/ocelot_fdma.h index 6c5c5872abf5..74514a0b291a 100644 --- a/drivers/net/ethernet/mscc/ocelot_fdma.h +++ b/drivers/net/ethernet/mscc/ocelot_fdma.h @@ -55,5 +55,6 @@ int ocelot_fdma_start(struct ocelot_fdma *fdma); int ocelot_fdma_stop(struct ocelot_fdma *fdma); int ocelot_fdma_inject_frame(struct ocelot_fdma *fdma, int port, u32 rew_op, struct sk_buff *skb, struct net_device *dev); +int ocelot_fdma_change_mtu(struct net_device *dev, int new_mtu); #endif diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c index 3971b810c5b4..d5e88d7b15c7 100644 --- a/drivers/net/ethernet/mscc/ocelot_net.c +++ b/drivers/net/ethernet/mscc/ocelot_net.c @@ -492,6 +492,13 @@ static int ocelot_change_mtu(struct net_device *dev, int new_mtu) struct ocelot_port_private *priv = netdev_priv(dev); struct ocelot_port *ocelot_port = &priv->port; struct ocelot *ocelot = ocelot_port->ocelot; + int ret; + + if (ocelot->fdma) { + ret = ocelot_fdma_change_mtu(dev, new_mtu); + if (ret) + return ret; + } ocelot_port_set_maxlen(ocelot, priv->chip_port, new_mtu); WRITE_ONCE(dev->mtu, new_mtu);