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=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 87C2AC3A59E for ; Mon, 26 Aug 2019 07:09:59 +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 5CD6F20874 for ; Mon, 26 Aug 2019 07:09:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CD6F20874 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 E7A71FF7; Mon, 26 Aug 2019 07:09:58 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 5AB03FEC for ; Mon, 26 Aug 2019 07:09:44 +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 EC75989B for ; Mon, 26 Aug 2019 07:09:43 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B04E568B02; Mon, 26 Aug 2019 09:09:39 +0200 (CEST) Date: Mon, 26 Aug 2019 09:09:39 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH v2 01/11] asm-generic: add dma_zone_size Message-ID: <20190826070939.GD11331@lst.de> References: <20190820145821.27214-1-nsaenzjulienne@suse.de> <20190820145821.27214-2-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190820145821.27214-2-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: catalin.marinas@arm.com, eric@anholt.net, linux-riscv@lists.infradead.org, frowand.list@gmail.com, hch@lst.de, linux-arch@vger.kernel.org, f.fainelli@gmail.com, will@kernel.org, devicetree@vger.kernel.org, Arnd Bergmann , marc.zyngier@arm.com, robh+dt@kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, phill@raspberryi.org, mbrugger@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, wahrenst@gmx.net, akpm@linux-foundation.org, Robin Murphy 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 Tue, Aug 20, 2019 at 04:58:09PM +0200, Nicolas Saenz Julienne wrote: > Some architectures have platform specific DMA addressing limitations. > This will allow for hardware description code to provide the constraints > in a generic manner, so as for arch code to properly setup it's memory > zones and DMA mask. I know this just spreads the arm code, but I still kinda hate it. MAX_DMA_ADDRESS is such an oddly defined concepts. We have the mm code that uses it to start allocating after the dma zones, but I think that would better be done using a function returning 1 << max(zone_dma_bits, 32) or so. Then we have about a handful of drivers using it that all seem rather bogus, and one of which I think are usable on arm64. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu