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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 4D7D3C4360C for ; Sun, 6 Oct 2019 17:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2498120673 for ; Sun, 6 Oct 2019 17:59:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570384783; bh=j8Ts51ouzUORb/g+SI+XF3GofZDMGyDqpfF2SFwJASg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Z+trFSbfnR+pOBVB6yKMqL81Mu5KkwQE8kYD8xLOkBvqViN7dzsauJIJUJWcC1W/j dIXfjMNEMSg3fvcUSCVG1tdplhVsPr6AvyCBVAsZXRaGyo2tJFGH2ezAeDE1rX7xxG y8uUkDPzt52a9LHc0GYjlRkJBvzZQz69cGowH0aY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728821AbfJFR7m (ORCPT ); Sun, 6 Oct 2019 13:59:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729206AbfJFRaQ (ORCPT ); Sun, 6 Oct 2019 13:30:16 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFF412133F; Sun, 6 Oct 2019 17:30:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570383016; bh=j8Ts51ouzUORb/g+SI+XF3GofZDMGyDqpfF2SFwJASg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1AHsUn1zqXENJsKeZLjOfwk4Rf8DaJSraGNrDbKlrelekmY2guPNxj+ANzwuFRH0k 40MCh9bNszmk5WtQO7oXuuxlsr5YGKbxOFV39b2nE5axeqYlhasqdZWAFpVt1MZePp +o3SW7dqHjZGOBBDnYoOosSwaiUpt/B5SwccWrn8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nathan Lynch , Michael Ellerman , Sasha Levin Subject: [PATCH 4.19 038/106] powerpc/pseries: correctly track irq state in default idle Date: Sun, 6 Oct 2019 19:20:44 +0200 Message-Id: <20191006171141.397412915@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171124.641144086@linuxfoundation.org> References: <20191006171124.641144086@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nathan Lynch [ Upstream commit 92c94dfb69e350471473fd3075c74bc68150879e ] prep_irq_for_idle() is intended to be called before entering H_CEDE (and it is used by the pseries cpuidle driver). However the default pseries idle routine does not call it, leading to mismanaged lazy irq state when the cpuidle driver isn't in use. Manifestations of this include: * Dropped IPIs in the time immediately after a cpu comes online (before it has installed the cpuidle handler), making the online operation block indefinitely waiting for the new cpu to respond. * Hitting this WARN_ON in arch_local_irq_restore(): /* * We should already be hard disabled here. We had bugs * where that wasn't the case so let's dbl check it and * warn if we are wrong. Only do that when IRQ tracing * is enabled as mfmsr() can be costly. */ if (WARN_ON_ONCE(mfmsr() & MSR_EE)) __hard_irq_disable(); Call prep_irq_for_idle() from pseries_lpar_idle() and honor its result. Fixes: 363edbe2614a ("powerpc: Default arch idle could cede processor on pseries") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190910225244.25056-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/platforms/pseries/setup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index ba1791fd3234d..67f49159ea708 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -325,6 +325,9 @@ static void pseries_lpar_idle(void) * low power mode by ceding processor to hypervisor */ + if (!prep_irq_for_idle()) + return; + /* Indicate to hypervisor that we are idle. */ get_lppaca()->idle = 1; -- 2.20.1