From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by kanga.kvack.org (Postfix) with ESMTP id 9B8378E0001 for ; Tue, 18 Sep 2018 16:28:25 -0400 (EDT) Received: by mail-qk1-f199.google.com with SMTP id z17-v6so2295715qka.9 for ; Tue, 18 Sep 2018 13:28:25 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id e23-v6si273457qta.54.2018.09.18.13.28.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Sep 2018 13:28:24 -0700 (PDT) Date: Tue, 18 Sep 2018 16:28:19 -0400 From: Jerome Glisse 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> Sender: owner-linux-mm@kvack.org List-ID: 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 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: Jerome 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); > >