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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 D47A5C433F4 for ; Tue, 18 Sep 2018 20:28:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A1322133F for ; Tue, 18 Sep 2018 20:28:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A1322133F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730296AbeISCCi (ORCPT ); Tue, 18 Sep 2018 22:02:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45166 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729200AbeISCCi (ORCPT ); Tue, 18 Sep 2018 22:02:38 -0400 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 448E180F95; Tue, 18 Sep 2018 20:28:23 +0000 (UTC) Received: from redhat.com (ovpn-124-13.rdu2.redhat.com [10.10.124.13]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2BCDC308BDA0; Tue, 18 Sep 2018 20:28:21 +0000 (UTC) Date: Tue, 18 Sep 2018 16:28:19 -0400 From: Jerome Glisse To: Dan Williams Cc: akpm@linux-foundation.org, Christoph Hellwig , Logan Gunthorpe , alexander.h.duyck@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support Message-ID: <20180918202818.GB14689@redhat.com> References: <153680531988.453305.8080706591516037706.stgit@dwillia2-desk3.amr.corp.intel.com> <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 18 Sep 2018 20:28:23 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 12, 2018 at 07:22:11PM -0700, Dan Williams wrote: > Given the fact that devm_memremap_pages() requires a percpu_ref that is > torn down by devm_memremap_pages_release() the current support for > mapping RAM is broken. > > Support for remapping "System RAM" has been broken since the beginning > and there is no existing user of this this code path, so just kill the > support and make it an explicit error. > > This cleanup also simplifies a follow-on patch to fix the error path > when setting a devm release action for devm_memremap_pages_release() > fails. > > Cc: Christoph Hellwig Reviewed-by: Jérôme Glisse > Cc: Logan Gunthorpe > Signed-off-by: Dan Williams > --- > kernel/memremap.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/kernel/memremap.c b/kernel/memremap.c > index f95c7833db6d..92e838127767 100644 > --- a/kernel/memremap.c > +++ b/kernel/memremap.c > @@ -202,15 +202,12 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) > is_ram = region_intersects(align_start, align_size, > IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); > > - if (is_ram == REGION_MIXED) { > - WARN_ONCE(1, "%s attempted on mixed region %pr\n", > - __func__, res); > + if (is_ram != REGION_DISJOINT) { > + WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, > + is_ram == REGION_MIXED ? "mixed" : "ram", res); > return ERR_PTR(-ENXIO); > } > > - if (is_ram == REGION_INTERSECTS) > - return __va(res->start); > - > if (!pgmap->ref) > return ERR_PTR(-EINVAL); > >