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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 9ECFAC433B4 for ; Tue, 6 Apr 2021 16:23:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DE6E613C0 for ; Tue, 6 Apr 2021 16:23:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346249AbhDFQXV (ORCPT ); Tue, 6 Apr 2021 12:23:21 -0400 Received: from foss.arm.com ([217.140.110.172]:45526 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346212AbhDFQXU (ORCPT ); Tue, 6 Apr 2021 12:23:20 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1CCE01063; Tue, 6 Apr 2021 09:23:12 -0700 (PDT) Received: from lpieralisi (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2813C3F792; Tue, 6 Apr 2021 09:23:11 -0700 (PDT) Date: Tue, 6 Apr 2021 17:23:05 +0100 From: Lorenzo Pieralisi To: Bjorn Andersson Cc: Will Deacon , Shawn Guo , Robin Murphy , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] iommu/arm-smmu-qcom: create qcom_smmu_impl for ACPI boot Message-ID: <20210406162305.GA28529@lpieralisi> References: <20210301074021.20059-1-shawn.guo@linaro.org> <20210325145914.GC15172@willie-the-truck> <20210325170256.GA904837@yoga> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210325170256.GA904837@yoga> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, Mar 25, 2021 at 12:02:56PM -0500, Bjorn Andersson wrote: > On Thu 25 Mar 09:59 CDT 2021, Will Deacon wrote: > > > [+ Lorenzo] > > > > On Mon, Mar 01, 2021 at 03:40:21PM +0800, Shawn Guo wrote: > > > Though qcom_adreno_smmu_impl is not used by ACPI boot right now, > > > qcom_smmu_impl is already required at least to boot up Lenovo Flex 5G > > > laptop. Let's check asl_compiler_id in IORT header to ensure we are > > > running a QCOM SMMU and create qcom_smmu_impl for it. > > > > > > !np is used to check ACPI boot, because fwnode of SMMU device is > > > a static allocation and thus has_acpi_companion() doesn't work here. > > > > > > Signed-off-by: Shawn Guo > > > --- > > > drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 33 ++++++++++++++++++++++ > > > 1 file changed, 33 insertions(+) > > > > I don't know what a "asl_compiler_id" is, but it doesn't sound like it > > has an awful lot to do with the SMMU. > > > > I would prefer that we somehow relate this to the particular board, > rather than all Qualcomm-related ACPI tables. E.g. by relying on the > SMMU devices having a _HID of QCOM0409. > > Shawn, any reason for this wouldn't be possible? > > > Lorenzo -- any idea what we should be doing here instead? Probably not > > using ACPI? > > > > The 8cx (aka sc8180x) platform comes with Qualcomm's usual SMMU > stream-mapping quirks and this is one of the patches needed to bring > enough ACPI support to run the Debian installer that Shawn has been > working on. After the installer we currently only boot this using DT - > which already enables the quirk. I am not sure I follow - can you explain please why this patch (and so the QCOM SMMU) is actually needed ? I don't get why getting the SMMU up and running with ACPI is mandatory to complete the process you describe above (but I am not sure I understood it entirely either - apologies). Thanks, Lorenzo