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,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 363A3C76195 for ; Fri, 19 Jul 2019 04:14:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02C0521872 for ; Fri, 19 Jul 2019 04:14:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509686; bh=ytGjSiLhOp0bN/LWXqjAt16ej47TiHINKjzeQitdMvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sLBRBxXs/9h9h1HSTdDAkQjimUMPapZbccbS8JwvQSm+zNiCzyvVc+iy+i5RJEARY W44JVIWNCEdAX6+zB7/AlaIuPAROHU8NEw8bZ4bqJ+98yoQkxOKMxb0q3vQeyWOL1h cufqqQx2RV6TCD86xPeET+2GfYQNUY2S4R0HfWTE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389844AbfGSEOo (ORCPT ); Fri, 19 Jul 2019 00:14:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:51022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729582AbfGSEOo (ORCPT ); Fri, 19 Jul 2019 00:14:44 -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 5767B2082F; Fri, 19 Jul 2019 04:14:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509684; bh=ytGjSiLhOp0bN/LWXqjAt16ej47TiHINKjzeQitdMvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PMb/++wWeROfBT305ZeDHnIHRJpgRT8vmH1GyuRuIkBJog2ZFsThgc1A7d2QtPiY2 Eki+LuhRHn11c/sukv+D+9wLvtzQD9oS9NiobwTDi7yQpQ6vduGOC1MCiXTm0ydimV TlQclRMO/7JPPvxyMxAlp/VoDv9C+lzBSmUBKxGg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Lynch , "Gautham R . Shenoy" , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.4 12/35] powerpc/pseries/mobility: prevent cpu hotplug during DT update Date: Fri, 19 Jul 2019 00:14:00 -0400 Message-Id: <20190719041423.19322-12-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719041423.19322-1-sashal@kernel.org> References: <20190719041423.19322-1-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: Nathan Lynch [ Upstream commit e59a175faa8df9d674247946f2a5a9c29c835725 ] CPU online/offline code paths are sensitive to parts of the device tree (various cpu node properties, cache nodes) that can be changed as a result of a migration. Prevent CPU hotplug while the device tree potentially is inconsistent. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch Reviewed-by: Gautham R. Shenoy Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/platforms/pseries/mobility.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c index c773396d0969..fcd1a32267c4 100644 --- a/arch/powerpc/platforms/pseries/mobility.c +++ b/arch/powerpc/platforms/pseries/mobility.c @@ -9,6 +9,7 @@ * 2 as published by the Free Software Foundation. */ +#include #include #include #include @@ -309,11 +310,19 @@ void post_mobility_fixup(void) if (rc) printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc); + /* + * We don't want CPUs to go online/offline while the device + * tree is being updated. + */ + cpus_read_lock(); + rc = pseries_devicetree_update(MIGRATION_SCOPE); if (rc) printk(KERN_ERR "Post-mobility device tree update " "failed: %d\n", rc); + cpus_read_unlock(); + /* Possibly switch to a new RFI flush type */ pseries_setup_rfi_flush(); -- 2.20.1