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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 8AABAC43463 for ; Mon, 21 Sep 2020 12:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56D84214F1 for ; Mon, 21 Sep 2020 12:06:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726683AbgIUMGI (ORCPT ); Mon, 21 Sep 2020 08:06:08 -0400 Received: from foss.arm.com ([217.140.110.172]:42038 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726355AbgIUMGH (ORCPT ); Mon, 21 Sep 2020 08:06:07 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A7E6AD6E; Mon, 21 Sep 2020 05:06:06 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.75.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id F19A23F73B; Mon, 21 Sep 2020 05:06:02 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, Anshuman Khandual , Will Deacon , Mark Rutland , Marc Zyngier , Steve Capper , Mark Brown , linux-kernel@vger.kernel.org Subject: [PATCH V3 2/3] arm64/mm/hotplug: Enable MEM_OFFLINE event handling Date: Mon, 21 Sep 2020 17:35:07 +0530 Message-Id: <1600689908-28213-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1600689908-28213-1-git-send-email-anshuman.khandual@arm.com> References: <1600689908-28213-1-git-send-email-anshuman.khandual@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This enables MEM_OFFLINE memory event handling. It will help intercept any possible error condition such as if boot memory some how still got offlined even after an explicit notifier failure, potentially by a future change in generic hot plug framework. This would help detect such scenarios and help debug further. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Marc Zyngier Cc: Steve Capper Cc: Mark Brown Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/mm/mmu.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index df3b7415b128..6b171bd88bcf 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1482,13 +1482,40 @@ static int prevent_bootmem_remove_notifier(struct notifier_block *nb, unsigned long end_pfn = arg->start_pfn + arg->nr_pages; unsigned long pfn = arg->start_pfn; - if (action != MEM_GOING_OFFLINE) + if ((action != MEM_GOING_OFFLINE) && (action != MEM_OFFLINE)) return NOTIFY_OK; - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - ms = __pfn_to_section(pfn); - if (early_section(ms)) - return NOTIFY_BAD; + if (action == MEM_GOING_OFFLINE) { + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + ms = __pfn_to_section(pfn); + if (early_section(ms)) { + pr_warn("Boot memory offlining attempted\n"); + return NOTIFY_BAD; + } + } + } else if (action == MEM_OFFLINE) { + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + ms = __pfn_to_section(pfn); + if (early_section(ms)) { + + /* + * This should have never happened. Boot memory + * offlining should have been prevented by this + * very notifier. Probably some memory removal + * procedure might have changed which would then + * require further debug. + */ + pr_err("Boot memory offlined\n"); + + /* + * Core memory hotplug does not process a return + * code from the notifier for MEM_OFFLINE event. + * Error condition has been reported. Report as + * ignored. + */ + return NOTIFY_DONE; + } + } } return NOTIFY_OK; } -- 2.20.1