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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7BA4FC04AB7 for ; Tue, 14 May 2019 14:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 589D521537 for ; Tue, 14 May 2019 14:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726772AbfENOEF (ORCPT ); Tue, 14 May 2019 10:04:05 -0400 Received: from mga05.intel.com ([192.55.52.43]:47286 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726314AbfENOC6 (ORCPT ); Tue, 14 May 2019 10:02:58 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 May 2019 07:02:58 -0700 X-ExtLoop1: 1 Received: from unknown (HELO luv-build.sc.intel.com) ([172.25.110.25]) by fmsmga005.fm.intel.com with ESMTP; 14 May 2019 07:02:58 -0700 From: Ricardo Neri To: Thomas Gleixner , Ingo Molnar , Borislav Petkov Cc: Ashok Raj , Joerg Roedel , Andi Kleen , Peter Zijlstra , "Ravi V. Shankar" , x86@kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Ricardo Neri , Ricardo Neri Subject: [RFC PATCH v3 09/21] x86/nmi: Add a NMI_WATCHDOG NMI handler category Date: Tue, 14 May 2019 07:02:02 -0700 Message-Id: <1557842534-4266-10-git-send-email-ricardo.neri-calderon@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1557842534-4266-1-git-send-email-ricardo.neri-calderon@linux.intel.com> References: <1557842534-4266-1-git-send-email-ricardo.neri-calderon@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a NMI_WATCHDOG as a new category of NMI handler. This new category is to be used with the HPET-based hardlockup detector. This detector does not have a direct way of checking if the HPET timer is the source of the NMI. Instead it indirectly estimate it using the time-stamp counter. Therefore, we may have false-positives in case another NMI occurs within the estimated time window. For this reason, we want the handler of the detector to be called after all the NMI_LOCAL handlers. A simple way of achieving this with a new NMI handler category. Signed-off-by: Ricardo Neri --- arch/x86/include/asm/nmi.h | 1 + arch/x86/kernel/nmi.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h index 75ded1d13d98..75aa98313cde 100644 --- a/arch/x86/include/asm/nmi.h +++ b/arch/x86/include/asm/nmi.h @@ -29,6 +29,7 @@ enum { NMI_UNKNOWN, NMI_SERR, NMI_IO_CHECK, + NMI_WATCHDOG, NMI_MAX }; diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 3755d0310026..a43213f0ab26 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -62,6 +62,10 @@ static struct nmi_desc nmi_desc[NMI_MAX] = .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock), .head = LIST_HEAD_INIT(nmi_desc[3].head), }, + { + .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[4].lock), + .head = LIST_HEAD_INIT(nmi_desc[4].head), + }, }; @@ -172,6 +176,8 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action) */ WARN_ON_ONCE(type == NMI_SERR && !list_empty(&desc->head)); WARN_ON_ONCE(type == NMI_IO_CHECK && !list_empty(&desc->head)); + WARN_ON_ONCE(type == NMI_WATCHDOG && !list_empty(&desc->head)); + /* * some handlers need to be executed first otherwise a fake @@ -382,6 +388,10 @@ static void default_do_nmi(struct pt_regs *regs) } raw_spin_unlock(&nmi_reason_lock); + handled = nmi_handle(NMI_WATCHDOG, regs); + if (handled == NMI_HANDLED) + return; + /* * Only one NMI can be latched at a time. To handle * this we may process multiple nmi handlers at once to -- 2.17.1