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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 04193C4CECE for ; Mon, 14 Oct 2019 20:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DAB0921848 for ; Mon, 14 Oct 2019 20:59:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731953AbfJNU7J (ORCPT ); Mon, 14 Oct 2019 16:59:09 -0400 Received: from foss.arm.com ([217.140.110.172]:52526 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731815AbfJNU7J (ORCPT ); Mon, 14 Oct 2019 16:59:09 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8A383337; Mon, 14 Oct 2019 13:59:08 -0700 (PDT) Received: from iMac-3.local (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BA5423F68E; Mon, 14 Oct 2019 13:59:06 -0700 (PDT) Date: Mon, 14 Oct 2019 21:59:00 +0100 From: Catalin Marinas To: Nicolas Saenz Julienne Cc: Robin Murphy , linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, linux-rpi-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-s390@vger.kernel.org, f.fainelli@gmail.com, linux-kernel@vger.kernel.org, hch@infradead.org, mbrugger@suse.com, wahrenst@gmx.net, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH RFC 0/5] ARM: Raspberry Pi 4 DMA support Message-ID: <20191014205859.GA7634@iMac-3.local> References: <20191014183108.24804-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191014183108.24804-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 14, 2019 at 08:31:02PM +0200, Nicolas Saenz Julienne wrote: > the Raspberry Pi 4 offers up to 4GB of memory, of which only the first > is DMA capable device wide. This forces us to use of bounce buffers, > which are currently not very well supported by ARM's custom DMA ops. > Among other things the current mechanism (see dmabounce.c) isn't > suitable for high memory. Instead of fixing it, this series introduces a > way of selecting dma-direct as the default DMA ops provider which allows > for the Raspberry Pi to make use of swiotlb. I presume these patches go on top of this series: http://lkml.kernel.org/r/20190911182546.17094-1-nsaenzjulienne@suse.de which I queued here: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/zone-dma -- Catalin