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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A76EAC4740C for ; Sun, 22 Sep 2019 18:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A4D021D7B for ; Sun, 22 Sep 2019 18:50:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178232; bh=o0TPlNlA6sE8SAGKH4X9ZsJIGV0LCZYH5UcKTwQ4ZXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uXdOkiD+Jg9FbVMk0ikL5wGzJA+Gm24jpktzYQNA71BYYtc6vTOMB2q0jkljWx28l lKCwN3r0ES+YlmQG2hg08xa8RypBZIQKJbqgu52KUMBn4avEGoOODh/+Urak3/4zya jUVh5eBY7AbUL+KHwPlowyOPiKDQLgcQggvhnLMQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729130AbfIVSua (ORCPT ); Sun, 22 Sep 2019 14:50:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:47644 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727512AbfIVSua (ORCPT ); Sun, 22 Sep 2019 14:50:30 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D062E21D7A; Sun, 22 Sep 2019 18:50:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178229; bh=o0TPlNlA6sE8SAGKH4X9ZsJIGV0LCZYH5UcKTwQ4ZXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=19iOUnsIGA91Oj06QOJnoundTpxUzaTVHqnLoplbF17HnNG2pw4GFzFUQfQKYFFWU eAQgJSok3VrKiM7+OTkgTthcA5vHbUpystpFhp8s/DlVorX1um/hj6iNeheQBLyMUH tHklJ6Ys83eCwhJmz5mkupmK14vJyzguyDyBSO54= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Gleixner , Peter Zijlstra , Sasha Levin Subject: [PATCH AUTOSEL 5.2 028/185] x86/apic: Soft disable APIC before initializing it Date: Sun, 22 Sep 2019 14:46:46 -0400 Message-Id: <20190922184924.32534-28-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922184924.32534-1-sashal@kernel.org> References: <20190922184924.32534-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Gleixner [ Upstream commit 2640da4cccf5cc613bf26f0998b9e340f4b5f69c ] If the APIC was already enabled on entry of setup_local_APIC() then disabling it soft via the SPIV register makes a lot of sense. That masks all LVT entries and brings it into a well defined state. Otherwise previously enabled LVTs which are not touched in the setup function stay unmasked and might surprise the just booting kernel. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20190722105219.068290579@linutronix.de Signed-off-by: Sasha Levin --- arch/x86/kernel/apic/apic.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 67d1259e0f7c0..a18d6dd934e55 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1550,6 +1550,14 @@ static void setup_local_APIC(void) return; } + /* + * If this comes from kexec/kcrash the APIC might be enabled in + * SPIV. Soft disable it before doing further initialization. + */ + value = apic_read(APIC_SPIV); + value &= ~APIC_SPIV_APIC_ENABLED; + apic_write(APIC_SPIV, value); + #ifdef CONFIG_X86_32 /* Pound the ESR really hard over the head with a big hammer - mbligh */ if (lapic_is_integrated() && apic->disable_esr) { -- 2.20.1