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 26719C27C76 for ; Wed, 25 Jan 2023 19:53:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236034AbjAYTw6 (ORCPT ); Wed, 25 Jan 2023 14:52:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235889AbjAYTwX (ORCPT ); Wed, 25 Jan 2023 14:52:23 -0500 Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0CF15924A for ; Wed, 25 Jan 2023 11:51:20 -0800 (PST) Received: by mail-ej1-x635.google.com with SMTP id hw16so50534063ejc.10 for ; Wed, 25 Jan 2023 11:51:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=PGQtNMCtF/zFqyjg+RVNx/g2xphXepovgWysJqLnw9w=; b=eJR9aQkXDReiK2529mb60Vo419A5Bu6Z3u7WpIl4js2WhPZGIQFSy/H4+p4NVIXaJc r7Wbb01tc97SVywSGhQ06K8PuXb1eFANcGB8N/1W5TTdeS7VMXfrSvxFtptvIY24zvpK UJ7aqQyuF3PM4yk6FlpHbu+TZSzo8e4rfvZ4fMHZQ8z0Vk9JpnOm9/Kj+XbuQ0Q0I80K HtDArDVy6VCc8K7Fbbt5DA+7BHe+/eyH7VEkdLOELJcleXkz5SwhrXM9MpW1gONi1uH8 el4p6hcH8QcBiHyEjnjDmJakvDDlTxv8p3l+e/wf/mZ6C/p9JacVIvhmZSJfdZNRvVfj /zcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=PGQtNMCtF/zFqyjg+RVNx/g2xphXepovgWysJqLnw9w=; b=rRbGOo6NAabjRLllUJqgLiY+wlj4V7avzD/k6bGE8rogzaSF0zRx5K8wt3/oflfVJy fzLXZTM6WOr35NT7XL1reghkintNzr7pR6og2KRcxfv3N0ASjEa7mrJrpqu67rCr7YdQ RXwa12/z9nsJqITh+XfMGCiQccPxwxdnDdDpGaInNa3eOnpEwz/1Wmpti2bgGVqtEylm KHzYmjeL/q9t9xmE5eNAVmbDpPI6Ovdp5FMpAN2t1L/eMPl8KC8N/rXVygh8DlhWsG0/ FH9Y8IM2l05AfkSG0bsnh8lPwm/qHpEybLMxSoIWOCtVtCPKQTGZAzvBews5T8N6c/Qe +ygg== X-Gm-Message-State: AFqh2kqcplQZYiJIQmeBiC0wM1dkdqhghrtZ5MZTQTLU/JD1OAOHlyV6 tbQNc7oiz0FGrBC9UXtu4SEIMg== X-Google-Smtp-Source: AMrXdXssGcS4R2vhME25W3esQjynCNwS4O80o7quVAzjlK/GgMiNikFP6qZ66Nporluvp40QSYCzOg== X-Received: by 2002:a17:906:2582:b0:877:573d:e91c with SMTP id m2-20020a170906258200b00877573de91cmr29810674ejb.63.1674676280502; Wed, 25 Jan 2023 11:51:20 -0800 (PST) Received: from blmsp.fritz.box ([2001:4091:a247:815f:ef74:e427:628a:752c]) by smtp.gmail.com with ESMTPSA id s15-20020a170906454f00b00872c0bccab2sm2778830ejq.35.2023.01.25.11.51.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jan 2023 11:51:20 -0800 (PST) From: Markus Schneider-Pargmann To: Marc Kleine-Budde , Chandrasekar Ramakrishnan , Wolfgang Grandegger Cc: Vincent MAILHOL , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Markus Schneider-Pargmann Subject: [PATCH v2 18/18] can: m_can: Implement transmit submission coalescing Date: Wed, 25 Jan 2023 20:50:59 +0100 Message-Id: <20230125195059.630377-19-msp@baylibre.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230125195059.630377-1-msp@baylibre.com> References: <20230125195059.630377-1-msp@baylibre.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org m_can supports submitting mulitple transmits with one register write. This is an interesting option to reduce the number of SPI transfers for peripheral chips. The m_can_tx_op is extended with a bool that signals if it is the last transmission and the submit should be executed immediately. The worker then writes the skb to the FIFO and submits it only if the submit bool is set. If it isn't set, the worker will write the next skb which is waiting in the workqueue to the FIFO, etc. Signed-off-by: Markus Schneider-Pargmann --- Notes: Notes: - I ran into lost messages in the receive FIFO when using this implementation. I guess this only shows up with my test setup in loopback mode and maybe not enough CPU power. - I put this behind the tx-frames ethtool coalescing option as we do wait before submitting packages but it is something different than the tx-frames-irq option. I am not sure if this is the correct option, please let me know. drivers/net/can/m_can/m_can.c | 55 ++++++++++++++++++++++++++++++++--- drivers/net/can/m_can/m_can.h | 6 ++++ 2 files changed, 57 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index c6a09369d1aa..99bfcfec3775 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1504,6 +1504,9 @@ static int m_can_start(struct net_device *dev) if (ret) return ret; + netdev_queue_set_dql_min_limit(netdev_get_tx_queue(cdev->net, 0), + cdev->tx_max_coalesced_frames); + cdev->can.state = CAN_STATE_ERROR_ACTIVE; m_can_enable_all_interrupts(cdev); @@ -1813,8 +1816,13 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, */ can_put_echo_skb(skb, dev, putidx, frame_len); - /* Enable TX FIFO element to start transfer */ - m_can_write(cdev, M_CAN_TXBAR, (1 << putidx)); + if (cdev->is_peripheral) { + /* Delay enabling TX FIFO element */ + cdev->tx_peripheral_submit |= BIT(putidx); + } else { + /* Enable TX FIFO element to start transfer */ + m_can_write(cdev, M_CAN_TXBAR, BIT(putidx)); + } cdev->tx_fifo_putidx = (++cdev->tx_fifo_putidx >= cdev->can.echo_skb_max ? 0 : cdev->tx_fifo_putidx); } @@ -1827,6 +1835,17 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, return NETDEV_TX_BUSY; } +static void m_can_tx_submit(struct m_can_classdev *cdev) +{ + if (cdev->version == 30) + return; + if (!cdev->is_peripheral) + return; + + m_can_write(cdev, M_CAN_TXBAR, cdev->tx_peripheral_submit); + cdev->tx_peripheral_submit = 0; +} + static void m_can_tx_work_queue(struct work_struct *ws) { struct m_can_tx_op *op = container_of(ws, struct m_can_tx_op, work); @@ -1835,11 +1854,15 @@ static void m_can_tx_work_queue(struct work_struct *ws) op->skb = NULL; m_can_tx_handler(cdev, skb); + if (op->submit) + m_can_tx_submit(cdev); } -static void m_can_tx_queue_skb(struct m_can_classdev *cdev, struct sk_buff *skb) +static void m_can_tx_queue_skb(struct m_can_classdev *cdev, struct sk_buff *skb, + bool submit) { cdev->tx_ops[cdev->next_tx_op].skb = skb; + cdev->tx_ops[cdev->next_tx_op].submit = submit; queue_work(cdev->tx_wq, &cdev->tx_ops[cdev->next_tx_op].work); ++cdev->next_tx_op; @@ -1851,6 +1874,7 @@ static netdev_tx_t m_can_start_peripheral_xmit(struct m_can_classdev *cdev, struct sk_buff *skb) { netdev_tx_t err; + bool submit; if (cdev->can.state == CAN_STATE_BUS_OFF) { m_can_clean(cdev->net); @@ -1861,7 +1885,15 @@ static netdev_tx_t m_can_start_peripheral_xmit(struct m_can_classdev *cdev, if (err != NETDEV_TX_OK) return err; - m_can_tx_queue_skb(cdev, skb); + ++cdev->nr_txs_without_submit; + if (cdev->nr_txs_without_submit >= cdev->tx_max_coalesced_frames || + !netdev_xmit_more()) { + cdev->nr_txs_without_submit = 0; + submit = true; + } else { + submit = false; + } + m_can_tx_queue_skb(cdev, skb, submit); return NETDEV_TX_OK; } @@ -1993,6 +2025,7 @@ static int m_can_get_coalesce(struct net_device *dev, ec->rx_max_coalesced_frames_irq = cdev->rx_max_coalesced_frames_irq; ec->rx_coalesce_usecs_irq = cdev->rx_coalesce_usecs_irq; + ec->tx_max_coalesced_frames = cdev->tx_max_coalesced_frames; ec->tx_max_coalesced_frames_irq = cdev->tx_max_coalesced_frames_irq; ec->tx_coalesce_usecs_irq = cdev->tx_coalesce_usecs_irq; @@ -2037,6 +2070,18 @@ static int m_can_set_coalesce(struct net_device *dev, netdev_err(dev, "tx-frames-irq and tx-usecs-irq can only be set together\n"); return -EINVAL; } + if (ec->tx_max_coalesced_frames > cdev->mcfg[MRAM_TXE].num) { + netdev_err(dev, "tx-frames (%u) greater than the TX event FIFO (%u)\n", + ec->tx_max_coalesced_frames, + cdev->mcfg[MRAM_TXE].num); + return -EINVAL; + } + if (ec->tx_max_coalesced_frames > cdev->mcfg[MRAM_TXB].num) { + netdev_err(dev, "tx-frames (%u) greater than the TX FIFO (%u)\n", + ec->tx_max_coalesced_frames, + cdev->mcfg[MRAM_TXB].num); + return -EINVAL; + } if (ec->rx_coalesce_usecs_irq != 0 && ec->tx_coalesce_usecs_irq != 0 && ec->rx_coalesce_usecs_irq != ec->tx_coalesce_usecs_irq) { netdev_err(dev, "rx-usecs-irq (%u) needs to be equal to tx-usecs-irq (%u) if both are enabled\n", @@ -2047,6 +2092,7 @@ static int m_can_set_coalesce(struct net_device *dev, cdev->rx_max_coalesced_frames_irq = ec->rx_max_coalesced_frames_irq; cdev->rx_coalesce_usecs_irq = ec->rx_coalesce_usecs_irq; + cdev->tx_max_coalesced_frames = ec->tx_max_coalesced_frames; cdev->tx_max_coalesced_frames_irq = ec->tx_max_coalesced_frames_irq; cdev->tx_coalesce_usecs_irq = ec->tx_coalesce_usecs_irq; @@ -2064,6 +2110,7 @@ static const struct ethtool_ops m_can_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS_IRQ | ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ | ETHTOOL_COALESCE_TX_USECS_IRQ | + ETHTOOL_COALESCE_TX_MAX_FRAMES | ETHTOOL_COALESCE_TX_MAX_FRAMES_IRQ, .get_ts_info = ethtool_op_get_ts_info, .get_coalesce = m_can_get_coalesce, diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h index bfef2c89e239..e209de81b5a4 100644 --- a/drivers/net/can/m_can/m_can.h +++ b/drivers/net/can/m_can/m_can.h @@ -74,6 +74,7 @@ struct m_can_tx_op { struct m_can_classdev *cdev; struct work_struct work; struct sk_buff *skb; + bool submit; }; struct m_can_classdev { @@ -103,6 +104,7 @@ struct m_can_classdev { u32 active_interrupts; u32 rx_max_coalesced_frames_irq; u32 rx_coalesce_usecs_irq; + u32 tx_max_coalesced_frames; u32 tx_max_coalesced_frames_irq; u32 tx_coalesce_usecs_irq; @@ -117,6 +119,10 @@ struct m_can_classdev { int tx_fifo_size; int next_tx_op; + int nr_txs_without_submit; + /* bitfield of fifo elements that will be submitted together */ + u32 tx_peripheral_submit; + struct mram_cfg mcfg[MRAM_CFG_NUM]; }; -- 2.39.0