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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 2A3C5C433E0 for ; Sat, 16 May 2020 00:12:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AB84207CB for ; Sat, 16 May 2020 00:12:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728417AbgEPAMj (ORCPT ); Fri, 15 May 2020 20:12:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727790AbgEPAKj (ORCPT ); Fri, 15 May 2020 20:10:39 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90209C061A0C for ; Fri, 15 May 2020 17:10:39 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jZkP7-00026Z-H6; Sat, 16 May 2020 02:10:13 +0200 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 0A3A7100605; Sat, 16 May 2020 02:10:13 +0200 (CEST) Message-Id: <20200515235124.891319901@linutronix.de> User-Agent: quilt/0.65 Date: Sat, 16 May 2020 01:45:52 +0200 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , Tom Lendacky , Wei Liu , Michael Kelley , Jason Chen CJ , Zhao Yakui , "Peter Zijlstra (Intel)" Subject: [patch V6 05/37] genirq: Provide irq_enter/exit_rcu() References: <20200515234547.710474468@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org irq_enter()/exit() include the RCU handling. To properly separate the RCU handling provide variants which contain only the non-RCU related functionality. Signed-off-by: Thomas Gleixner diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index a4c5a1df067e..f6f25fab34cb 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -43,7 +43,11 @@ extern void rcu_nmi_exit(void); /* * Enter irq context (on NO_HZ, update jiffies): */ -extern void irq_enter(void); +void irq_enter(void); +/* + * Like irq_enter(), but RCU is already watching. + */ +void irq_enter_rcu(void); /* * Exit irq context without processing softirqs: @@ -58,7 +62,12 @@ extern void irq_enter(void); /* * Exit irq context and process softirqs if needed: */ -extern void irq_exit(void); +void irq_exit(void); + +/* + * Like irq_exit(), but return with RCU watching. + */ +void irq_exit_rcu(void); #ifndef arch_nmi_enter #define arch_nmi_enter() do { } while (0) diff --git a/kernel/softirq.c b/kernel/softirq.c index a47c6dd57452..beb8e3a66c7c 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -339,12 +339,11 @@ asmlinkage __visible void do_softirq(void) local_irq_restore(flags); } -/* - * Enter an interrupt context. +/** + * irq_enter_rcu - Enter an interrupt context with RCU watching */ -void irq_enter(void) +void irq_enter_rcu(void) { - rcu_irq_enter(); if (is_idle_task(current) && !in_interrupt()) { /* * Prevent raise_softirq from needlessly waking up ksoftirqd @@ -354,10 +353,18 @@ void irq_enter(void) tick_irq_enter(); _local_bh_enable(); } - __irq_enter(); } +/** + * irq_enter - Enter an interrupt context including RCU update + */ +void irq_enter(void) +{ + rcu_irq_enter(); + irq_enter_rcu(); +} + static inline void invoke_softirq(void) { if (ksoftirqd_running(local_softirq_pending())) @@ -397,10 +404,12 @@ static inline void tick_irq_exit(void) #endif } -/* - * Exit an interrupt context. Process softirqs if needed and possible: +/** + * irq_exit_rcu() - Exit an interrupt context without updating RCU + * + * Also processes softirqs if needed and possible. */ -void irq_exit(void) +void irq_exit_rcu(void) { #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); @@ -413,6 +422,16 @@ void irq_exit(void) invoke_softirq(); tick_irq_exit(); +} + +/** + * irq_exit - Exit an interrupt context, update RCU and lockdep + * + * Also processes softirqs if needed and possible. + */ +void irq_exit(void) +{ + irq_exit_rcu(); rcu_irq_exit(); /* must be last! */ lockdep_hardirq_exit();