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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 AF430C433DB for ; Mon, 15 Feb 2021 16:16:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8270164DEE for ; Mon, 15 Feb 2021 16:16:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231715AbhBOQPv (ORCPT ); Mon, 15 Feb 2021 11:15:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:46856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231196AbhBOPed (ORCPT ); Mon, 15 Feb 2021 10:34:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7A75661490; Mon, 15 Feb 2021 15:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613403082; bh=efafAd6WaDg8SGnlqP87Caf8A64qt4Co/sdcXkCnQTM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fw6Jaw7pMDXHh4ayHDH2vED1MzN0YV8mfrBYdX2Fur9hVkcANrGYmLcY+xsTx6Ma1 rmi6H43PRNuGOCLk3rd3llzkkAPcdeVxH5xEkGCKMd0OiZwfl/h4GCCziugFuyw38d pzq0vpWov1yubuYDWMKcxYFRVnhgri00UY1Cmpxk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Lezcano , "Paul E. McKenney" , Russell King , Tony Lindgren , Sasha Levin Subject: [PATCH 5.10 020/104] ARM: OMAP2+: Fix suspcious RCU usage splats for omap_enter_idle_coupled Date: Mon, 15 Feb 2021 16:26:33 +0100 Message-Id: <20210215152720.133238537@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210215152719.459796636@linuxfoundation.org> References: <20210215152719.459796636@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tony Lindgren [ Upstream commit 06862d789ddde8a99c1e579e934ca17c15a84755 ] We get suspcious RCU usage splats with cpuidle in several places in omap_enter_idle_coupled() with the kernel debug options enabled: RCU used illegally from extended quiescent state! ... (_raw_spin_lock_irqsave) (omap_enter_idle_coupled+0x17c/0x2d8) (omap_enter_idle_coupled) (cpuidle_enter_state) (cpuidle_enter_state_coupled) (cpuidle_enter) Let's use RCU_NONIDLE to suppress these splats. Things got changed around with commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path") that started triggering these warnings. For the tick_broadcast related calls, ideally we'd just switch over to using CPUIDLE_FLAG_TIMER_STOP for omap_enter_idle_coupled() to have the generic cpuidle code handle the tick_broadcast related calls for us and then just drop the tick_broadcast calls here. But we're currently missing the call in the common cpuidle code for tick_broadcast_enable() that CPU1 hotplug needs as described in earlier commit 50d6b3cf9403 ("ARM: OMAP2+: fix lack of timer interrupts on CPU1 after hotplug"). Cc: Daniel Lezcano Cc: Paul E. McKenney Cc: Russell King Acked-by: Paul E. McKenney Signed-off-by: Tony Lindgren Signed-off-by: Sasha Levin --- arch/arm/mach-omap2/cpuidle44xx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index c8d317fafe2ea..de37027ad7587 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -151,10 +151,10 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, (cx->mpu_logic_state == PWRDM_POWER_OFF); /* Enter broadcast mode for periodic timers */ - tick_broadcast_enable(); + RCU_NONIDLE(tick_broadcast_enable()); /* Enter broadcast mode for one-shot timers */ - tick_broadcast_enter(); + RCU_NONIDLE(tick_broadcast_enter()); /* * Call idle CPU PM enter notifier chain so that @@ -166,7 +166,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, if (dev->cpu == 0) { pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); - omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state)); /* * Call idle CPU cluster PM enter notifier chain @@ -178,7 +178,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, index = 0; cx = state_ptr + index; pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); - omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state)); mpuss_can_lose_context = 0; } } @@ -194,9 +194,9 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, mpuss_can_lose_context) gic_dist_disable(); - clkdm_deny_idle(cpu_clkdm[1]); - omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON); - clkdm_allow_idle(cpu_clkdm[1]); + RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1])); + RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON)); + RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1])); if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && mpuss_can_lose_context) { @@ -222,7 +222,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, cpu_pm_exit(); cpu_pm_out: - tick_broadcast_exit(); + RCU_NONIDLE(tick_broadcast_exit()); fail: cpuidle_coupled_parallel_barrier(dev, &abort_barrier); -- 2.27.0