From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752014AbeBWSA4 (ORCPT ); Fri, 23 Feb 2018 13:00:56 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:59136 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751527AbeBWSAz (ORCPT ); Fri, 23 Feb 2018 13:00:55 -0500 Message-ID: <5A90563E.4020608@arm.com> Date: Fri, 23 Feb 2018 17:58:22 +0000 From: James Morse User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.6.0 MIME-Version: 1.0 To: Dongjiu Geng CC: catalin.marinas@arm.com, will.deacon@arm.com, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, huangshaoyu@huawei.com Subject: Re: [PATCH] arm64: rename the function arm64_is_ras_serror() to avoid confusion References: <1519322552-7374-1-git-send-email-gengdongjiu@huawei.com> In-Reply-To: <1519322552-7374-1-git-send-email-gengdongjiu@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dongjiu Geng, On 22/02/18 18:02, Dongjiu Geng wrote: > The RAS SError Syndrome can be Implementation-Defined, > arm64_is_ras_serror() is used to judge whether it is RAS SError, > but arm64_is_ras_serror() does not include this judgement. In order > to avoid function name confusion, we rename the arm64_is_ras_serror() > to arm64_is_categorized_ras_serror(), this function is used to > judge whether it is categorized RAS Serror. I don't see how 'categorized' is relevant. The most significant ISS bit is used to determine if this is an IMP-DEF ESR, or one that uses the architected layout. DFSC of zero means uncategorised. What should we do with an uncategorised SError? >>From 2.4.3 "ESB and other physical errors" of [0] | It is IMPLEMENTATION DEFINED whether [..]uncategorized SError interrupts | are containable or Uncontainable, and whether they can be synchronized by an | Error Synchronization Barrier. We treat uncategorized as uncontainable as that's the worst thing it could be. On aarch32 uncontainable and uncategorized even share an encoding. (AET:00 in G7.2.43 "DFSR, Data Fault Status Register", 'state of the PE after taking the SError interrupt exception') > Change some code notes, unrecoverable RAS errors is imprecise, but > Recoverable RAS errors is precise. Unrecoverable and Recoverable (but we don't know where it is) are both grouped into 'can't make progress'. The comment says: | The exception may have been imprecise. because one of those two is imprecise. If anyone cares which one is which, they can read the spec. I expect this code will one day be replaced with proper kernel-first support, its only here to avoid panic()ing due to corrected errors. Thanks, James [0] https://static.docs.arm.com/ddi0587/a/RAS%20Extension-release%20candidate_march_29.pdf