From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) by kanga.kvack.org (Postfix) with ESMTP id F1F1F8E0001 for ; Thu, 13 Sep 2018 12:10:52 -0400 (EDT) Received: by mail-io1-f72.google.com with SMTP id s15-v6so4858720iob.11 for ; Thu, 13 Sep 2018 09:10:52 -0700 (PDT) Received: from ale.deltatee.com (ale.deltatee.com. [207.54.116.67]) by mx.google.com with ESMTPS id c1-v6si3022717iok.212.2018.09.13.09.10.50 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 13 Sep 2018 09:10:51 -0700 (PDT) References: <153680531988.453305.8080706591516037706.stgit@dwillia2-desk3.amr.corp.intel.com> <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> From: Logan Gunthorpe Message-ID: <50c1172d-29c6-4509-de0d-897163b0b2e4@deltatee.com> Date: Thu, 13 Sep 2018 10:10:45 -0600 MIME-Version: 1.0 In-Reply-To: <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support Sender: owner-linux-mm@kvack.org List-ID: To: Dan Williams , akpm@linux-foundation.org Cc: Christoph Hellwig , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , alexander.h.duyck@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 12/09/18 08:22 PM, 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 > Cc: "JA(C)rA'me Glisse" > Cc: Logan Gunthorpe > Signed-off-by: Dan Williams Reviewed-by: Logan Gunthorpe Logan > --- > 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); > >