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=-15.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL 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 8C99DC2D0E2 for ; Tue, 22 Sep 2020 22:37:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E5B020715 for ; Tue, 22 Sep 2020 22:37:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="LZItGfNo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726713AbgIVWhK (ORCPT ); Tue, 22 Sep 2020 18:37:10 -0400 Received: from linux.microsoft.com ([13.77.154.182]:60682 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726662AbgIVWhJ (ORCPT ); Tue, 22 Sep 2020 18:37:09 -0400 Received: from [192.168.1.171] (50-39-235-197.bvtn.or.frontiernet.net [50.39.235.197]) by linux.microsoft.com (Postfix) with ESMTPSA id 1508920B7179; Tue, 22 Sep 2020 15:37:09 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1508920B7179 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1600814229; bh=ClwMIaEy1QkOug3GZQC9xiEgNvcZxX8uczkxLFHFqh8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=LZItGfNojTl6mkytfVVoC0bv8uWfNuAm4O+yL0CV3M1p16sUodwOl7UeKSdCC3Jjp jDiDKmyPNrCyl41pbnvRZlnSU0S4/EDIHlVoJeBNGZp5hyVL218Z6QDyqjHYrIus+A d94Y64Yk3ZocNDV8HOZqm7ZAlTv8QChWSIONOCIo= Subject: Re: [PATCH v2] iommu/arm: Add module parameter to set msi iova address To: Will Deacon Cc: robin.murphy@arm.com, joro@8bytes.org, srinath.mannam@broadcom.com, jean-philippe@linaro.org, eric.auger@redhat.com, shameerali.kolothum.thodi@huawei.com, tyhicks@linux.microsoft.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com References: <20200914181307.117792-1-vemegava@linux.microsoft.com> <20200921204545.GA3811@willie-the-truck> From: Vennila Megavannan Message-ID: Date: Tue, 22 Sep 2020 15:37:08 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: <20200921204545.GA3811@willie-the-truck> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sure, that's a great suggestion, I'll rework on the patch and post again. Vennila On 9/21/2020 1:45 PM, Will Deacon wrote: > On Mon, Sep 14, 2020 at 11:13:07AM -0700, Vennila Megavannan wrote: >> From: Srinath Mannam >> >> Add provision to change default value of MSI IOVA base to platform's >> suitable IOVA using module parameter. The present hardcoded MSI IOVA base >> may not be the accessible IOVA ranges of platform. >> >> If any platform has the limitaion to access default MSI IOVA, then it can >> be changed using "arm-smmu.msi_iova_base=0xa0000000" command line argument. >> >> Signed-off-by: Srinath Mannam >> Co-developed-by: Vennila Megavannan >> Signed-off-by: Vennila Megavannan >> --- >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 ++++- >> drivers/iommu/arm/arm-smmu/arm-smmu.c | 5 ++++- >> 2 files changed, 8 insertions(+), 2 deletions(-) > This feels pretty fragile. Wouldn't it be better to realise that there's > a region conflict with iommu_dma_get_resv_regions() and move the MSI window > accordingly at runtime? > > Will