+ mm-devm_memremap_pages-kill-mapping-system-ram-support.patch added to -mm tree

The patch titled
     Subject: mm, devm_memremap_pages: kill mapping "System RAM" support
has been added to the -mm tree.  Its filename is
     mm-devm_memremap_pages-kill-mapping-system-ram-support.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-devm_memremap_pages-kill-mapping-system-ram-support.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-devm_memremap_pages-kill-mapping-system-ram-support.patch

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------------------------------------------------------
From: Dan Williams <redacted>
Subject: mm, devm_memremap_pages: kill mapping "System RAM" support

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.

Link: http://lkml.kernel.org/r/154275557997.76910.14689813630968180480.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <redacted>
Reviewed-by: "Jérôme Glisse" <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

--- a/kernel/memremap.c~mm-devm_memremap_pages-kill-mapping-system-ram-support
+++ a/kernel/memremap.c

@@ -167,15 +167,12 @@ void *devm_memremap_pages(struct device
 	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);
 

_

Patches currently in -mm which might be from dan.j.williams@intel.com are

mm-devm_memremap_pages-mark-devm_memremap_pages-export_symbol_gpl.patch
mm-devm_memremap_pages-kill-mapping-system-ram-support.patch
mm-devm_memremap_pages-fix-shutdown-handling.patch
mm-devm_memremap_pages-add-memory_device_private-support.patch
mm-hmm-use-devm-semantics-for-hmm_devmem_add-remove.patch
mm-hmm-replace-hmm_devmem_pages_create-with-devm_memremap_pages.patch
mm-hmm-mark-hmm_devmem_add-add_resource-export_symbol_gpl.patch