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=-2.5 required=3.0 tests=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 17AC9C43219 for ; Tue, 30 Apr 2019 21:16:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBAD02087B for ; Tue, 30 Apr 2019 21:16:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726559AbfD3VQM (ORCPT ); Tue, 30 Apr 2019 17:16:12 -0400 Received: from verein.lst.de ([213.95.11.211]:49203 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726015AbfD3VQM (ORCPT ); Tue, 30 Apr 2019 17:16:12 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id 2CE8867358; Tue, 30 Apr 2019 23:15:54 +0200 (CEST) Date: Tue, 30 Apr 2019 23:15:54 +0200 From: Christoph Hellwig To: Paul Burton Cc: Christoph Hellwig , Ralf Baechle , James Hogan , Ley Foon Tan , Michal Simek , Bartlomiej Zolnierkiewicz , "linux-mips@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-fbdev@vger.kernel.org" Subject: Re: [PATCH 5/7] MIPS: use the generic uncached segment support in dma-direct Message-ID: <20190430211553.GA31109@lst.de> References: <20190430110032.25301-1-hch@lst.de> <20190430110032.25301-6-hch@lst.de> <20190430201041.536amvinrcvd2wua@pburton-laptop> <20190430202947.GA30262@lst.de> <20190430211105.ielntedm46uqamca@pburton-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190430211105.ielntedm46uqamca@pburton-laptop> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Tue, Apr 30, 2019 at 09:11:07PM +0000, Paul Burton wrote: > Right but dma_direct_alloc_pages() already checks for the PageHighMem > case & returns before ever calling arch_dma_prep_coherent(), no? True. And of course it can't be remapped into the uncached segment anyway. So yes, we should drop it. Eventually I want to add generic support for DMA_ATTR_NO_KERNEL_MAPPING, but that'll involved auditing all instances anyway.