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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 E3BADC43142 for ; Thu, 2 Aug 2018 07:35:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BA0A20C0B for ; Thu, 2 Aug 2018 07:35:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BA0A20C0B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727125AbeHBJZG (ORCPT ); Thu, 2 Aug 2018 05:25:06 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:53466 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726145AbeHBJZG (ORCPT ); Thu, 2 Aug 2018 05:25:06 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6C62180D; Thu, 2 Aug 2018 00:35:14 -0700 (PDT) Received: from big-swifty.misterjones.org (big-swifty.copenhagen.arm.com [10.32.148.139]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B9BBE3F2EA; Thu, 2 Aug 2018 00:35:09 -0700 (PDT) Date: Thu, 02 Aug 2018 08:35:02 +0100 Message-ID: <86r2jhw7a1.wl-marc.zyngier@arm.com> From: Marc Zyngier To: Thomas Gleixner Cc: Ricardo Neri , Julien Thierry , LKML , Peter Zijlstra , Ingo Molnar Subject: Re: [PATCH 1/4] genirq: Provide basic NMI management for interrupt lines In-Reply-To: References: <1532430427-57151-1-git-send-email-julien.thierry@arm.com> <1532430427-57151-2-git-send-email-julien.thierry@arm.com> <20180801030723.GA31383@voyager> <20180802020320.GC31758@voyager> <86tvodw9wz.wl-marc.zyngier@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/25.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Organization: ARM Ltd MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 02 Aug 2018 07:55:49 +0100, Thomas Gleixner wrote: > > On Thu, 2 Aug 2018, Marc Zyngier wrote: > > > > If we need to distinguish between the two, then we need two flags. One > > that indicates the generation capability, and one that indicates the > > forwarding capability. > > There is absolutely no reason to expose this on x86, really. > > Why? > > Because NMI is an utter trainwreck on x86. It's a single entry point > without the ability of differentiation from which source the NMI > originated. So mapping it to anything generic is just not going to work. > > It has absolutely nothing to do with the normal way of vector based > interrupt operation and I don't see at all how adding this just because > would improve anything on x86. In fact it would create more problems than > it solves. Fair enough. Does it mean Julien can completely ignore the x86 requirements for this and focus on something that fit the need of architectures where (pseudo-)NMIs can be managed similarly to normal interrupts (arm, arm64, sparc...)? Thanks, M. -- Jazz is not dead, it just smell funny.