Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933696AbcLNW2w (ORCPT ); Wed, 14 Dec 2016 17:28:52 -0500 Received: from mail-qk0-f178.google.com ([209.85.220.178]:33336 "EHLO mail-qk0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933070AbcLNW2v (ORCPT ); Wed, 14 Dec 2016 17:28:51 -0500 Subject: Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory To: Rob Herring , Jason Liu References: <1479901021-25064-1-git-send-email-jason.hui.liu@nxp.com> Cc: "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Frank Rowand From: Laura Abbott Message-ID: <833f99b1-d10b-27ba-e0f9-a7c6398fb63d@redhat.com> Date: Wed, 14 Dec 2016 14:21:26 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 845 Lines: 23 On 12/14/2016 12:45 PM, Rob Herring wrote: > On Wed, Nov 23, 2016 at 5:37 AM, Jason Liu wrote: >> Need ensure the cma reserved region not cross the low/high memory boundary >> when using the dynamic allocation methond through device-tree, otherwise, >> kernel will fail to boot up when cma reserved region cross how/high mem. > > The kernel command line code setting CMA already deals with this. Why > don't we just call the CMA code (cma_declare_contiguous) to deal with > this? > > Rob > That was proposed in the first version[1] but I think this is a generic problem not specific to CMA. Even non-CMA reservations trying to span zones could cause problems so the devicetree allocation code should restrict reservations to a single zone. Thanks, Laura [1] https://marc.info/?l=linux-kernel&m=147928325113103&w=2