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=-3.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 DF599C2F42E for ; Mon, 21 Jan 2019 15:07:54 +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 B17AE20879 for ; Mon, 21 Jan 2019 15:07:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="l7errO1Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B17AE20879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+T8PS/lx0h7vEzb/apEvPmfMUL6c8AK6BoNpcWX6GA8=; b=l7errO1Y/ingWU QkrLjqhmpFN9w1XBFLDJQC5vKo31mH7MlXcebm4OG0aMJQUPFzyNgz2/9YzBQz7MCSbA+WNQFyvgy OQLK8FUv8vQbbYA22AY3M5BZLo7nk96sxjhIDz+l9ol9fVCmT6N0Eg3mKjDggNtB4Pm1hM4nMMVgP +Ictq9tooNKOVyvdaCsXfvCkOSl7ZCf+OGxLz3kkPY/k/bmqTXx/ayvhTF4OQnK5qpBV7M4gj4eHS jBTLu13mLAueyCVJfnlmTGpP/HawfG1uKVBDdx3ROeXXHUtadGZr90TljnKIGvSdV/nVOQ5cMLHWF 8ZAmC61BVUg6VZ2LFQ4A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1glbB3-0001M1-1Y; Mon, 21 Jan 2019 15:07:53 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1glbAk-00015z-Kc; Mon, 21 Jan 2019 15:07:34 +0000 Date: Mon, 21 Jan 2019 07:07:34 -0800 From: Christoph Hellwig To: Ard Biesheuvel Subject: Re: [RFC PATCH] drm: disable WC optimization for cache coherent devices on non-x86 Message-ID: <20190121150734.GA30582@infradead.org> References: <20190121100617.2311-1-ard.biesheuvel@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190121100617.2311-1-ard.biesheuvel@linaro.org> User-Agent: Mutt/1.9.2 (2017-12-15) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Will Deacon , David Zhou , Maxime Ripard , Benjamin Herrenschmidt , David Airlie , Maarten Lankhorst , Michel Daenzer , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, Junwei Zhang , Huang Rui , dri-devel@lists.freedesktop.org, Daniel Vetter , Michael Ellerman , Alex Deucher , Sean Paul , Christian Koenig , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org > +#include This header is not for usage in device drivers, but purely for dma-mapping implementations! > +static inline bool drm_device_can_wc_memory(struct drm_device *ddev) > { > + if (IS_ENABLED(CONFIG_PPC)) > + return IS_ENABLED(CONFIG_NOT_COHERENT_CACHE); > + else if (IS_ENABLED(CONFIG_MIPS)) > + return !IS_ENABLED(CONFIG_CPU_LOONGSON3); > + else if (IS_ENABLED(CONFIG_X86)) > + return true; > + > + return !dev_is_dma_coherent(ddev->dev); And even if something like this was valid to do, it would have to be a core function with an arch hook, and not hidden in a random driver. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel