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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 1CDCCC432BE for ; Sat, 24 Jul 2021 20:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8EC460725 for ; Sat, 24 Jul 2021 20:48:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229570AbhGXUHj (ORCPT ); Sat, 24 Jul 2021 16:07:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbhGXUHj (ORCPT ); Sat, 24 Jul 2021 16:07:39 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABE52C061575 for ; Sat, 24 Jul 2021 13:48:10 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m7OZ7-0004ju-5j for linux-can@vger.kernel.org; Sat, 24 Jul 2021 22:48:09 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 392AB65715F for ; Sat, 24 Jul 2021 20:48:08 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id CEB7B657150; Sat, 24 Jul 2021 20:48:05 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 54be8e7a; Sat, 24 Jul 2021 20:48:04 +0000 (UTC) From: Marc Kleine-Budde To: linux-can@vger.kernel.org Cc: kernel@pengutronix.de, Marc Kleine-Budde , =?UTF-8?q?Daniel=20Gl=C3=B6ckner?= , Oleksij Rempel Subject: [PATCH can-next 3/3] can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt Date: Sat, 24 Jul 2021 22:47:46 +0200 Message-Id: <20210724204745.736053-4-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210724204745.736053-1-mkl@pengutronix.de> References: <20210724204745.736053-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Suggested-by: Daniel Glöckner Tested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/rx-offload.c | 23 +++++++++++++++++++ drivers/net/can/m_can/m_can.c | 2 +- .../net/can/spi/mcp251xfd/mcp251xfd-core.c | 4 ++-- include/linux/can/rx-offload.h | 1 + 4 files changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c index 82ade3aa5c13..37b0cc65237b 100644 --- a/drivers/net/can/dev/rx-offload.c +++ b/drivers/net/can/dev/rx-offload.c @@ -299,6 +299,29 @@ void can_rx_offload_irq_finish(struct can_rx_offload *offload) } EXPORT_SYMBOL_GPL(can_rx_offload_irq_finish); +void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload) +{ + unsigned long flags; + int queue_len; + + if (skb_queue_empty_lockless(&offload->skb_irq_queue)) + return; + + spin_lock_irqsave(&offload->skb_queue.lock, flags); + skb_queue_splice_tail_init(&offload->skb_irq_queue, &offload->skb_queue); + spin_unlock_irqrestore(&offload->skb_queue.lock, flags); + + queue_len = skb_queue_len(&offload->skb_queue); + if (queue_len > offload->skb_queue_len_max / 8) + netdev_dbg(offload->dev, "%s: queue_len=%d\n", + __func__, queue_len); + + local_bh_disable(); + napi_schedule(&offload->napi); + local_bh_enable(); +} +EXPORT_SYMBOL_GPL(can_rx_offload_threaded_irq_finish); + static int can_rx_offload_init_queue(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 18461982f7a1..317cdc98c539 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1059,7 +1059,7 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) } if (cdev->is_peripheral) - can_rx_offload_irq_finish(&cdev->offload); + can_rx_offload_threaded_irq_finish(&cdev->offload); return IRQ_HANDLED; } diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index f3b267ec22e0..6962ab2749df 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -2196,7 +2196,7 @@ static irqreturn_t mcp251xfd_irq(int irq, void *dev_id) priv->regs_status.intf); if (!(intf_pending)) { - can_rx_offload_irq_finish(&priv->offload); + can_rx_offload_threaded_irq_finish(&priv->offload); return handled; } @@ -2298,7 +2298,7 @@ static irqreturn_t mcp251xfd_irq(int irq, void *dev_id) } while (1); out_fail: - can_rx_offload_irq_finish(&priv->offload); + can_rx_offload_threaded_irq_finish(&priv->offload); netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n", err, priv->regs_status.intf); diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h index 516f64df0ebc..c11477620403 100644 --- a/include/linux/can/rx-offload.h +++ b/include/linux/can/rx-offload.h @@ -50,6 +50,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload, int can_rx_offload_queue_tail(struct can_rx_offload *offload, struct sk_buff *skb); void can_rx_offload_irq_finish(struct can_rx_offload *offload); +void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload); void can_rx_offload_del(struct can_rx_offload *offload); void can_rx_offload_enable(struct can_rx_offload *offload); -- 2.30.2