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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 34923C433FF for ; Wed, 7 Aug 2019 06:04:43 +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 0DE85229ED for ; Wed, 7 Aug 2019 06:04:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Cti2vwCb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DE85229ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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=Duo9glXH1sbpSxx9u21hppxGmGn/WsOvlkor7pOSi5Y=; b=Cti2vwCb3PMuCT oKe2W+u+s8dgNV/dCHtsFCXLAHTTkBMnFJpQ1F8JXtMR6IuGv++xf8uoA0VOZSeUweA2HMtYbmPo6 qorYLMlJjXiCnMy/KT5dMTdvh5CcDqsZlRhdKTkl4H47AlHbP+RvCAf8nE2CWyjKR/KtjIunH1b/M 5d8b9HnmWO8d2zkQoozdvf31cvq/+uwYjUnb7j/kaNXMHzbvlyXwAT8Ns6ORwwYHoIPnNbnGZJ6VT 5LDeqy6BDEgdQIweBVF2zbvS4a9xobaeF3rOJL9Tyqgtl6YASvFmasHDs75D+W+Humcg9WCmuzrHr vpRgDyYuDZCTfSHgpf2Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hvF3y-0002Ex-JZ; Wed, 07 Aug 2019 06:04:42 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hvF3u-0002E6-QP for linux-arm-kernel@lists.infradead.org; Wed, 07 Aug 2019 06:04:40 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id BFD0A68CEE; Wed, 7 Aug 2019 08:04:33 +0200 (CEST) Date: Wed, 7 Aug 2019 08:04:32 +0200 From: Christoph Hellwig To: Shawn Anastasio Subject: Re: [PATCH 1/2] dma-mapping: fix page attributes for dma_mmap_* Message-ID: <20190807060432.GD6627@lst.de> References: <20190805080145.5694-1-hch@lst.de> <20190805080145.5694-2-hch@lst.de> <7df95ffb-6df3-b118-284c-ee32cad81199@anastas.io> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7df95ffb-6df3-b118-284c-ee32cad81199@anastas.io> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190806_230438_999603_EC7993CA X-CRM114-Status: GOOD ( 14.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gavin Li , linux-kernel@vger.kernel.org, Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Russell King , linux-mips@vger.kernel.org, iommu@lists.linux-foundation.org, Paul Burton , Catalin Marinas , James Hogan , Will Deacon , Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Robin Murphy 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 On Tue, Aug 06, 2019 at 09:39:06PM +0200, Shawn Anastasio wrote: >> -#ifdef CONFIG_ARCH_HAS_DMA_MMAP_PGPROT >> pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, >> unsigned long attrs); >> -#else >> -# define arch_dma_mmap_pgprot(dev, prot, attrs) pgprot_noncached(prot) >> -#endif > > Nit, but maybe the prototype should still be ifdef'd here? It at least > could prevent a reader from incorrectly thinking that the function is > always present. Actually it is typical modern Linux style to just provide a prototype and then use "if (IS_ENABLED(CONFIG_FOO))" to guard the call(s) to it. > > Also, like Will mentioned earlier, the function name isn't entirely > accurate anymore. I second the suggestion of using something like > arch_dma_noncoherent_pgprot(). As mentioned I plan to remove arch_dma_mmap_pgprot for 5.4, so I'd rather avoid churn for the short period of time. > As for your idea of defining > pgprot_dmacoherent for all architectures as > > #ifndef pgprot_dmacoherent > #define pgprot_dmacoherent pgprot_noncached > #endif > > I think that the name here is kind of misleading too, since this > definition will only be used when there is no support for proper > DMA coherency. Do you have a suggestion for a better name? I'm pretty bad at naming, so just reusing the arm name seemed like a good way to avoid having to make naming decisions myself. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel