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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 3616EC64EB8 for ; Tue, 9 Oct 2018 16:03:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D329E2087D for ; Tue, 9 Oct 2018 16:03:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D329E2087D 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-pci-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbeJIXVF (ORCPT ); Tue, 9 Oct 2018 19:21:05 -0400 Received: from foss.arm.com ([217.140.101.70]:40910 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726393AbeJIXVF (ORCPT ); Tue, 9 Oct 2018 19:21:05 -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 7A89A80D; Tue, 9 Oct 2018 09:03:28 -0700 (PDT) Received: from edgewater-inn.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4AE4A3F5D3; Tue, 9 Oct 2018 09:03:28 -0700 (PDT) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id A3A561AE0B3B; Tue, 9 Oct 2018 17:03:27 +0100 (BST) Date: Tue, 9 Oct 2018 17:03:27 +0100 From: Will Deacon To: Bjorn Helgaas Cc: Keith Busch , Linux PCI , Bjorn Helgaas , Benjamin Herrenschmidt , Sinan Kaya , Thomas Tai , poza@codeaurora.org, Lukas Wunner , Christoph Hellwig , Mika Westerberg , Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/12] error handling and pciehp maintenance Message-ID: <20181009160327.GE9259@arm.com> References: <20180918235848.26694-1-keith.busch@intel.com> <20181004214015.GK120535@bhelgaas-glaptop.roam.corp.google.com> <20181004221137.GB21834@localhost.localdomain> <20181005173145.GL120535@bhelgaas-glaptop.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181005173145.GL120535@bhelgaas-glaptop.roam.corp.google.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Bjorn, On Fri, Oct 05, 2018 at 12:31:45PM -0500, Bjorn Helgaas wrote: > [+cc arm64 folks, LKML: This conversation is about this patch: > > https://lore.kernel.org/linux-pci/20180918235848.26694-3-keith.busch@intel.com > > which fixes some PCIe AER error injection bugs, but also makes the error > injector dependent on DYNAMIC_FTRACE_WITH_REGS, which not all arches > support. Note that this question is only about the error *injection* > module used for testing. It doesn't affect AER support itself.] > > On Thu, Oct 04, 2018 at 04:11:37PM -0600, Keith Busch wrote: > > In case this went unnoticed, patch 2's aer_inject using ftrace hooks > > to pci config accessors is really cool and fixes several kernel crashes > > I encountered, but it may not work on every architecture. I'm not sure > > how widely aer_inject is used, so maybe there are no concerns with the > > DYNAMIC_FTRACE_WITH_REGS dependency, but I just want to reemphasize that > > dependency in case there are valid objections. > > Oh, indeed, I hadn't noticed this arch dependency. AFAICT, the new > DYNAMIC_FTRACE_WITH_REGS dependency means aer_inject will work only > on these arches: > > arm # if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU > powerpc # if PPC64 && CPU_LITTLE_ENDIAN > riscv # ARCH_RV64I only > s390 > x86 > > Notably missing is arm64, which has DYNAMIC_FTRACE but not > DYNAMIC_FTRACE_WITH_REGS. Thanks for the heads-up here. This feature is currently in development for arm64: http://lkml.kernel.org/r/20181001141648.1DBED68BDF@newverein.lst.de but the latest review comments suggest that it's a fair way from ready yet, so I wouldn't hold your breath. Will