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 2C0D2C10F14 for ; Sun, 6 Oct 2019 17:26:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 041E520867 for ; Sun, 6 Oct 2019 17:26:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382761; bh=WZWvLpu91GzMfveMKVhwBFKltwv+EJOdKuq185tjW3k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DuhKGTYW7vbyUgvh92GxLAP92vMo/kulaiZm43nWs+vAbDNjcxYR5yz6HqVyNtx2Q 2R9onUz4DoIOEtxfxxKkgkAX0KXMddsUN8NG9hQMWwM0yztdc6JV7E8+9QYDGFgfU1 PTwPoXGToUKSz1uencbPxOBkSLbasK6lH9VKiLko= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728154AbfJFR0A (ORCPT ); Sun, 6 Oct 2019 13:26:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:50778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728107AbfJFRZr (ORCPT ); Sun, 6 Oct 2019 13:25:47 -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 B9D3820867; Sun, 6 Oct 2019 17:25:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382746; bh=WZWvLpu91GzMfveMKVhwBFKltwv+EJOdKuq185tjW3k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2vx7vrifXKHhenN1d0pSTYsAtJesxDnciZ1b3adfa53GgFVDLt8MChmli6ZY10jKo G121WVGYjcuNPVj9/5Em5fdcrB/zW7T/kZ1IgSPBZutn1pIsyUYfm+d/SfDBOhBUbZ lCmW6TVF+XJA/WcxRu3//CHyuO3PTpRrOiksZko4= 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 4.14 24/68] powerpc/pseries: correctly track irq state in default idle Date: Sun, 6 Oct 2019 19:21:00 +0200 Message-Id: <20191006171119.261595375@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171108.150129403@linuxfoundation.org> References: <20191006171108.150129403@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 6a0ad56e89b93..7a9945b350536 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -307,6 +307,9 @@ 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