LKML Archive on lore.kernel.org
 help / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: "Christoph Hellwig" <hch@lst.de>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Logan Gunthorpe" <logang@deltatee.com>,
	alexander.h.duyck@intel.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support
Date: Wed, 12 Sep 2018 19:22:11 -0700
Message-ID: <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <153680531988.453305.8080706591516037706.stgit@dwillia2-desk3.amr.corp.intel.com>

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 <hch@lst.de>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 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);
 


  parent reply index

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-13  2:22 [PATCH v5 0/7] mm: Merge hmm into devm_memremap_pages, mark GPL-only Dan Williams
2018-09-13  2:22 ` [PATCH v5 1/7] mm, devm_memremap_pages: Mark devm_memremap_pages() EXPORT_SYMBOL_GPL Dan Williams
2018-09-13 16:25   ` Logan Gunthorpe
2018-09-13  2:22 ` Dan Williams [this message]
2018-09-13 16:10   ` [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support Logan Gunthorpe
2018-09-14 13:14   ` Christoph Hellwig
2018-09-14 17:40     ` Dan Williams
2018-09-18 20:28   ` Jerome Glisse
2018-09-13  2:22 ` [PATCH v5 3/7] mm, devm_memremap_pages: Fix shutdown handling Dan Williams
2018-09-14 13:16   ` Christoph Hellwig
2018-09-14 17:25     ` Dan Williams
2018-09-18 20:28   ` Jerome Glisse
2018-09-13  2:22 ` [PATCH v5 4/7] mm, devm_memremap_pages: Add MEMORY_DEVICE_PRIVATE support Dan Williams
2018-09-14 13:18   ` Christoph Hellwig
2018-09-18 20:34   ` Jerome Glisse
2018-09-13  2:22 ` [PATCH v5 5/7] mm, hmm: Use devm semantics for hmm_devmem_{add, remove} Dan Williams
2018-09-14 13:18   ` Christoph Hellwig
2018-09-14 14:16     ` Jerome Glisse
2018-09-18 20:34   ` Jerome Glisse
2018-09-13  2:22 ` [PATCH v5 6/7] mm, hmm: Replace hmm_devmem_pages_create() with devm_memremap_pages() Dan Williams
2018-09-18 20:35   ` Jerome Glisse
2018-09-19  1:24   ` Balbir Singh
2018-09-13  2:22 ` [PATCH v5 7/7] mm, hmm: Mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL Dan Williams

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com \
    --to=dan.j.williams@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.h.duyck@intel.com \
    --cc=hch@lst.de \
    --cc=jglisse@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=logang@deltatee.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox