Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp6367493yba; Wed, 1 May 2019 10:50:31 -0700 (PDT) X-Google-Smtp-Source: APXvYqwH7CNQSnviUy8wTsZwJNgjNn+IcdjdexZ7jXWktQHv5eGTDzvhPgcT7PBefQ1zZsZ2/Omj X-Received: by 2002:a65:6496:: with SMTP id e22mr33195070pgv.249.1556733031900; Wed, 01 May 2019 10:50:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556733031; cv=none; d=google.com; s=arc-20160816; b=rs9BHmoc0J1Ghu5TM7SLuj+BNj/vt0EJMqLfDrJ/fuIE/VovqwlBK+l6qD7XuvIjQC Rki49kuIk7dbWQo7J2hENxdas5HqHw/jOBr5s8OW5b0Pzz6jhBFDS3YJffi4NhociHBH baOHFsML/Y+wCO9MxQCU0cWdW+ZSdzcB8pPvYr4Qr2IEkE1DqNowdstg1ogQ9X/zKvRg onpV78OcSjos++rtF83cG8Hmfv8z2311wsNkAQnL6k6JKF5H9kpW+3RjsNSipwc99JYZ u6BDNg3yA8zawmNE9MjKOtHsKjRfTaZh5NkCf0D1szb93xjOPZ/ztXeqiXBQ/J+AJmou mpoQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=ZT0jQfiqSs4F0uPCAqKQq07V5My1R02O5gI+u7VLKFg=; b=AVDZzENnGTr+N+x9DRZBXewcA05zkWCxdn/hZkNKVUcEOv6XVqmHGO8VPICHi/VMJh vlp79f6QdPCOu89AmI86T3O+LuWDzy3/Otl6Xj6VglnX5XjWo67GSohgVVPZr6TeeV2K be6hh22dXHiMy4NxpV2QJOXHYzdMd0HE5SLuhHq0uaONPRpYwUGYDfmvBxgKJ/Ve1OoW qYBJVJTKh1oWlJLTfIvmtShNTSEX1oku+aZEQAfN6DA3ds1ZLNgGr02vY3hmpl+A1Hhd qryy1mAdjg2IBeymTTIVq1JDaHtVE0SF0nT6nFJG8kifHa/pVzx6g+Yr5OHr4xZbdOTo X47A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u13si32701896pgp.146.2019.05.01.10.50.16; Wed, 01 May 2019 10:50:31 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726229AbfEARtZ (ORCPT + 99 others); Wed, 1 May 2019 13:49:25 -0400 Received: from verein.lst.de ([213.95.11.211]:54199 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbfEARtZ (ORCPT ); Wed, 1 May 2019 13:49:25 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id BB11B68AFE; Wed, 1 May 2019 19:49:05 +0200 (CEST) Date: Wed, 1 May 2019 19:49:05 +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 4/7] dma-direct: provide generic support for uncached kernel segments Message-ID: <20190501174905.GA20458@lst.de> References: <20190430110032.25301-1-hch@lst.de> <20190430110032.25301-5-hch@lst.de> <20190501171857.chfxqntvm6r4xrr4@pburton-laptop> <20190501172912.GA19375@lst.de> <20190501174033.6rj5aiopdeo4uqpw@pburton-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190501174033.6rj5aiopdeo4uqpw@pburton-laptop> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 01, 2019 at 05:40:34PM +0000, Paul Burton wrote: > > > If it is necessary then as-is this code will clear the allocated memory > > > using uncached writes which will be pretty slow. It would be much more > > > efficient to perform the memset before arch_dma_prep_coherent() & before > > > converting ret to an uncached address. > > > > Yes, we could do that. > > Great; using cached writes would match the existing MIPS behavior. Can you test the stack with the two updated patches and ack them if they are fine? That would allow getting at least the infrastructure and mips in for this merge window.