From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932974AbdKALeq (ORCPT ); Wed, 1 Nov 2017 07:34:46 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:46116 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932501AbdKALeo (ORCPT ); Wed, 1 Nov 2017 07:34:44 -0400 Message-ID: <59F9B0E9.5090609@arm.com> Date: Wed, 01 Nov 2017 11:32:57 +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, marc.zyngier@arm.com, christoffer.dall@linaro.org, mark.rutland@arm.com, ard.biesheuvel@linaro.org, robin.murphy@arm.com, cov@codeaurora.org, Dave.Martin@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v1 0/3] manually add Error Synchronization Barrier at exception handler entry and exit References: <1509563697-6359-1-git-send-email-gengdongjiu@huawei.com> In-Reply-To: <1509563697-6359-1-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 01/11/17 19:14, Dongjiu Geng wrote: > Some hardware platform can support RAS Extension, but not support IESB, > such as Huawei's platform, so software need to insert Synchronization Barrier > operations at exception handler entry. > > This series patches are based on James's series patches "SError rework + > RAS&IESB for firmware first support". In Huawei's platform, we do not > support IESB, so software needs to insert that. Surely you don't implement it because your CPU doesn't need it. Can unrecoverable errors really cross an exception without becoming an SError? The ESB instruction does the barrier, but it also consumes any pending SError. As it is this series will silently consume-and-discard uncontainable errors. Thanks, James