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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 858BDC2D0DB for ; Fri, 24 Jan 2020 14:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 622C42077C for ; Fri, 24 Jan 2020 14:29:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391307AbgAXO3T (ORCPT ); Fri, 24 Jan 2020 09:29:19 -0500 Received: from 8bytes.org ([81.169.241.247]:60796 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391259AbgAXO3M (ORCPT ); Fri, 24 Jan 2020 09:29:12 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 44E89AA1; Fri, 24 Jan 2020 15:29:10 +0100 (CET) Date: Fri, 24 Jan 2020 15:29:07 +0100 From: Joerg Roedel To: Shuah Khan Cc: suravee.suthikulpanit@amd.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] iommu: amd: Fix IOMMU perf counter clobbering during init Message-ID: <20200124142907.GA27081@8bytes.org> References: <20200123223214.2566-1-skhan@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200123223214.2566-1-skhan@linuxfoundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 23, 2020 at 03:32:14PM -0700, Shuah Khan wrote: > init_iommu_perf_ctr() clobbers the register when it checks write access > to IOMMU perf counters and fails to restore when they are writable. > > Add save and restore to fix it. > > Signed-off-by: Shuah Khan > --- > Changes since v1: > -- Fix bug in sucessful return path. Add a return instead of > fall through to pc_false error case > > drivers/iommu/amd_iommu_init.c | 24 ++++++++++++++++++------ > 1 file changed, 18 insertions(+), 6 deletions(-) Applied for v5.5, thanks.