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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 2999BC76195 for ; Thu, 18 Jul 2019 09:15:45 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 085592173B for ; Thu, 18 Jul 2019 09:15:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 085592173B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 0F1CC13F4; Thu, 18 Jul 2019 09:15:44 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 398A0EC5 for ; Thu, 18 Jul 2019 09:15:29 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id ABFC825A for ; Thu, 18 Jul 2019 09:15:28 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 5018A68B05; Thu, 18 Jul 2019 11:15:26 +0200 (CEST) Date: Thu, 18 Jul 2019 11:15:26 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [RFC 3/4] dma-direct: add dma_direct_min_mask Message-ID: <20190718091526.GA25321@lst.de> References: <20190717153135.15507-1-nsaenzjulienne@suse.de> <20190717153135.15507-4-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190717153135.15507-4-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: stefan.wahren@i2se.com, f.fainelli@gmail.com, catalin.marinas@arm.com, phil@raspberrypi.org, Robin Murphy , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jisheng.Zhang@synaptics.com, mbrugger@suse.com, will@kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote: > Historically devices with ZONE_DMA32 have been assumed to be able to > address at least the lower 4GB of ram for DMA. This is still the defualt > behavior yet the Raspberry Pi 4 is limited to the first GB of memory. > This has been observed to trigger failures in dma_direct_supported() as > the 'min_mask' isn't properly set. > > We create 'dma_direct_min_mask' in order for the arch init code to be > able to fine-tune dma direct's 'min_dma' mask. Normally we use ZONE_DMA for that case. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu