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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 007EAC433F5 for ; Mon, 11 Oct 2021 06:11:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C262C60E98 for ; Mon, 11 Oct 2021 06:11:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C262C60E98 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Sun, 10 Oct 2021 23:09:01 -0700 (PDT) X-Gm-Message-State: AOAM530zJovjmijMVnF26glMBiPpbh5unRkotOfpMOKdWQMJEBq33/dU SGx68ISTbZ3bf6cjubzwSTUVi+sDHCBRl/5jzT8= X-Google-Smtp-Source: ABdhPJzokqOl1FjpKWa7hPmI46vA3MbqNwtIHx5QkXa4cBkJuMWag11qBpJwNxvearH05lPT0JSjYqMCvI8xjMjduAg= X-Received: by 2002:a05:600c:1548:: with SMTP id f8mr6604283wmg.35.1633932541412; Sun, 10 Oct 2021 23:09:01 -0700 (PDT) MIME-Version: 1.0 References: <20211010023350.978638-1-dmitry.baryshkov@linaro.org> In-Reply-To: From: Arnd Bergmann Date: Mon, 11 Oct 2021 08:08:44 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] iommu: fix ARM_SMMU vs QCOM_SCM compilation To: Dmitry Baryshkov Cc: Arnd Bergmann , Bjorn Andersson , Joerg Roedel , Will Deacon , Robin Murphy , Kalle Valo , Thierry Reding , Andy Gross , linux-arm-msm , "open list:IOMMU DRIVERS" , Linux Kernel Mailing List , Linux ARM , Daniel Lezcano X-Provags-ID: V03:K1:e6AYWiQ31p5FJOzk7PU1OQPtHS+y8sdnj61oUODtOpLwYMquJrX R2ybWu99bUBbAWPxag3FPLNF9Yhj7bOxlVuXf30DPLgt/Os5LQOoyZ/udcu5kQSWS3JyWcV Xhy/QtNjHaRJJnpuq0rVp+ADAy0QD4vpA+S5EhsmZQfxanJXrwrYsVgr5cKduzxweckn+EI Q+txgmw5qmoKSTJ8JtcpA== X-UI-Out-Filterresults: notjunk:1;V03:K0:DR7msHlOaDE=:JjetUkUikxkvcpdUfw4jbR gt1K54/C7X5n7rfBsY/0Vu62reicvnHxw0F5KFBvFojZwgic9iCXGx4b2goUpCYa0ya6uZYZi NGU8G3RFTauQp5SerL8KKrxOtkg4TwuY8lVRaqaAD+nitmoXRlAkoZUy1++hSya9GjfGHkdVc 0vZ3kN5RpjF5yxEfqTiPrjKNNld4hnuT60Q7GAcCuC+NDICparBrBOZn61UyoK4mtq6OdHJtG e2kJiigvAwAUbIDOc1FC/ea1+uF+jnQA2zkcn/xPTWBb16etW44aooRHwfMA2PlaVWyI1EZeY mAd7IwVbVzOWpVS4uf2Q3IeLDx/M4+e/63WrQnw5lfyXW5dPetKOVRZLI3vhlk9Vf30YRqStb 3zPEqVkFuZmh44H3AAjTL6NEAwC38/6WzKmyQ1caTDPJSlUsjF0TLdybsqEXayOLS8r7aMjve c1pzF3Y2fY61u2N0x5Hqwey2GsuiKm+MgXhAEaVN5RkmU11DJkWEIq3mKWgHwClLfI4/QRSav 28jtB9KJl7xB3Y+wtPgAxNLJOfbRYzSAmh5mB1cfi//fUFzAtAN0J5iXjW2s2bHWlqFF4Ml8c HKrTVfGpev0YHIyyfkhssKdjdeMFogfR2PbP+K4bu6GOBfW5NIt0sCvZAoAXEyArjwL83K1fV wEO8A8qx7q7FBgZvzauRlt95ZoXwSdhXz0Q/tpzqUsp5wKA4k983l+EwB7eLCFajwsrEVMqOS NbUWTXFqDYq3sf2l59pKeD+lo832SWIQXF+hrLPWbCiDWnT3pJJe4qaHj/dpBuC8aqqaH5TyB 3vOVQbgoDigLEwCbmPHvFBpM5+dKMLkZS9ClrywVmb3JhfEwcDdnXcsMPiTNVWT1VcZ6i9oy4 MwvLiKXDlIsTqfzg9vog== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211010_230904_364678_D6E463BB X-CRM114-Status: GOOD ( 14.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 11, 2021 at 6:11 AM Dmitry Baryshkov wrote: > On Sun, 10 Oct 2021 at 20:42, Arnd Bergmann wrote: > > The patch seems correct, but it becomes overcomplicated. What about: > - restoring QCOM_SCM stubs The stubs are what has led to the previous bugs in this area to often go unnoticed for too long, as illustrated by your suggestion > - making ARM_SMMU select QCOM_SCM if ARM_SMMU_QCOM I assume you meant "select QCOM_SCM if ARCH_QCOM", after we stop using ARM_SMMU_QCOM? > This would have almost the same result as with your patch, but without > extra ARM_SMMU_QCOM Kconfig symbol. The "almost" is the problem: consider the case of CONFIG_ARM=y CONFIG_COMPILE_TEST=y CONFIG_ARCH_QCOM=n CONFIG_ARM_SMMU=y CONFIG_DRM_MSM=m CONFIG_QCOM_SCM=m (selected by DRM_MSM) The stubs here lead to ARM_SMMU linking against the QCOM_SCM driver from built-in code, which fails because QCOM_SCM itself is a loadable module. We can move the "select QCOM_SCM" in the ARM_SMMU_QCOM symbol if we make that a tristate though, if you want to separate it a little more. Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel