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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 3017CC10F0E for ; Mon, 15 Apr 2019 11:30:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05DAF20848 for ; Mon, 15 Apr 2019 11:30:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727277AbfDOLaj (ORCPT ); Mon, 15 Apr 2019 07:30:39 -0400 Received: from foss.arm.com ([217.140.101.70]:32784 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727243AbfDOLaj (ORCPT ); Mon, 15 Apr 2019 07:30:39 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2C68A80D; Mon, 15 Apr 2019 04:30:39 -0700 (PDT) Received: from [10.162.43.203] (unknown [10.162.43.203]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2795C3F706; Mon, 15 Apr 2019 04:30:35 -0700 (PDT) Subject: Re: [PATCH RESEND 3/3] mm: introduce ARCH_HAS_PTE_DEVMAP To: Robin Murphy , linux-mm@kvack.org Cc: dan.j.williams@intel.com, ira.weiny@intel.com, jglisse@redhat.com, oohall@gmail.com, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <25525e4dab6ebc49e233f21f7c29821223431647.1555093412.git.robin.murphy@arm.com> From: Anshuman Khandual Message-ID: Date: Mon, 15 Apr 2019 17:00:35 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <25525e4dab6ebc49e233f21f7c29821223431647.1555093412.git.robin.murphy@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/13/2019 12:31 AM, Robin Murphy wrote: > ARCH_HAS_ZONE_DEVICE is somewhat meaningless in itself, and combined > with the long-out-of-date comment can lead to the impression than an > architecture may just enable it (since __add_pages() now "comprehends > device memory" for itself) and expect things to work. > > In practice, however, ZONE_DEVICE users have little chance of > functioning correctly without __HAVE_ARCH_PTE_DEVMAP, so let's clean > that up the same way as ARCH_HAS_PTE_SPECIAL and make it the proper > dependency so the real situation is clearer. > > Signed-off-by: Robin Murphy Reviewed-by: Anshuman Khandual