From patchwork Sun Sep 27 19:48:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 297463 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=-7.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 9155DC4727F for ; Sun, 27 Sep 2020 20:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D437239A1 for ; Sun, 27 Sep 2020 20:01:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="lvqAAX6a"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="M/WUbhe6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726906AbgI0T5R (ORCPT ); Sun, 27 Sep 2020 15:57:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726868AbgI0T5L (ORCPT ); Sun, 27 Sep 2020 15:57:11 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E385C0613D4; Sun, 27 Sep 2020 12:57:10 -0700 (PDT) Message-Id: <20200927194920.103181773@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1601236629; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=+Td6yEJdX0u3alrzHn3f95NHXVsu8voDQUxA06qKs/o=; b=lvqAAX6akfP4YZ7xFR4LpOwETarHeBRFLM2QGdZc6nT5AgVB/4sW2QV0rl1zrbXxtvs875 uZ8s+pnZL9IX+9ZQfTf5t6ubPQkkOAQKHI+5xe32z1/so/OlLrIFEAdPXMqAbdUuiLNy5I fw7MItHEk107qSjVOj8KnpKG8kTTP08LGiPqAldfmFKC2LrcUAKL6CyyZnYa2MZMx8KS3B 6g8oqlDFUUUxl3EiGW19U2kDoo63JtxfAx/i53g2+VghRAPyJbTb+QqsHxxgd/RYJaCNl1 OviMTI9zuVPOfs1dRgwlCiQPoBX9PY1w9BIsFYvtkhosg5mXWaHYXe6j6KmRnA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1601236629; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=+Td6yEJdX0u3alrzHn3f95NHXVsu8voDQUxA06qKs/o=; b=M/WUbhe6ErdCayGy1R//fNscpvFnmw4BpbV19BilmIiQfA+0Y1FoXJBx98Nu47G3KEOcgz 7H3xxIcvoG/sxZDQ== Date: Sun, 27 Sep 2020 21:48:49 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Linus Torvalds , Paul McKenney , Matthew Wilcox , Sebastian Andrzej Siewior , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, Christian Benvenuti , Govindarajulu Varadarajan <_govind@gmx.com>, Dave Miller , Jonathan Corbet , Mauro Carvalho Chehab , linux-doc@vger.kernel.org, Luc Van Oostenryck , Jay Cliburn , Chris Snook , Vishal Kulkarni , Jeff Kirsher , intel-wired-lan@lists.osuosl.org, Shannon Nelson , Pensando Drivers , Andrew Lunn , Heiner Kallweit , Russell King , Thomas Bogendoerfer , Solarflare linux maintainers , Edward Cree , Martin Habets , Jon Mason , Daniel Drake , Ulrich Kunitz , Kalle Valo , linux-wireless@vger.kernel.org, linux-usb@vger.kernel.org, Greg Kroah-Hartman , Arend van Spriel , Franky Lin , Hante Meuleman , Chi-Hsien Lin , Wright Feng , brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com, Stanislav Yakovlev , Stanislaw Gruszka , Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Jouni Malinen , Amitkumar Karwar , Ganapathi Bhat , Xinming Hu , libertas-dev@lists.infradead.org, Pascal Terjan , Ping-Ke Shih Subject: [patch 03/35] net: Add netif_rx_any_context() References: <20200927194846.045411263@linutronix.de> MIME-Version: 1.0 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Sebastian Andrzej Siewior Quite some drivers make conditional decisions based on in_interrupt() to invoke either netif_rx() or netif_rx_ni(). Conditionals based on in_interrupt() or other variants of preempt count checks in drivers should not exist for various reasons and Linus clearly requested to either split the code pathes or pass an argument to the common functions which provides the context. This is obviously the correct solution, but for some of the affected drivers this needs a major rewrite due to their convoluted structure. As in_interrupt() usage in drivers needs to be phased out, provide netif_rx_any_context() as a stop gap for these drivers. This confines the in_interrupt() conditional to core code which in turn allows to remove the access to this check for driver code and provides one central place to do further modifications once the driver maze is cleaned up. Suggested-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: "David S. Miller" Cc: Jakub Kicinski Cc: netdev@vger.kernel.org --- include/linux/netdevice.h | 1 + net/core/dev.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3764,6 +3764,7 @@ void generic_xdp_tx(struct sk_buff *skb, int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb); int netif_rx(struct sk_buff *skb); int netif_rx_ni(struct sk_buff *skb); +int netif_rx_any_context(struct sk_buff *skb); int netif_receive_skb(struct sk_buff *skb); int netif_receive_skb_core(struct sk_buff *skb); void netif_receive_skb_list(struct list_head *head); --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4840,6 +4840,21 @@ int netif_rx_ni(struct sk_buff *skb) } EXPORT_SYMBOL(netif_rx_ni); +int netif_rx_any_context(struct sk_buff *skb) +{ + /* + * If invoked from contexts which do not invoke bottom half + * processing either at return from interrupt or when softrqs are + * reenabled, use netif_rx_ni() which invokes bottomhalf processing + * directly. + */ + if (in_interrupt()) + return netif_rx(skb); + else + return netif_rx_ni(skb); +} +EXPORT_SYMBOL(netif_rx_any_context); + static __latent_entropy void net_tx_action(struct softirq_action *h) { struct softnet_data *sd = this_cpu_ptr(&softnet_data);