From: Christoph Hellwig <hch@lst.de>
Date: Wed, 16 Feb 2022 15:31:35 +1100
Subject: mm: move free_devmap_managed_page to memremap.c
Git-commit: 75e55d8a107edb2fd6e02b1fa8a81531209cda04
Patch-mainline: v5.18-rc1
References: jsc#PED-1294

free_devmap_managed_page has nothing to do with the code in swap.c,
move it to live with the rest of the code for devmap handling.

Link: https://lkml.kernel.org/r/20220210072828.2930359-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 include/linux/mm.h |    1 -
 mm/memremap.c      |   21 +++++++++++++++++++++
 mm/swap.c          |   23 -----------------------
 3 files changed, 21 insertions(+), 24 deletions(-)

--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1149,7 +1149,6 @@ static inline bool is_zone_movable_page(
 }
 
 #ifdef CONFIG_DEV_PAGEMAP_OPS
-void free_devmap_managed_page(struct page *page);
 DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
 
 static inline bool page_is_devmap_managed(struct page *page)
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -530,4 +530,25 @@ void free_devmap_managed_page(struct pag
 	page->mapping = NULL;
 	page->pgmap->ops->page_free(page);
 }
+
+void put_devmap_managed_page(struct page *page)
+{
+	int count;
+
+	if (WARN_ON_ONCE(!page_is_devmap_managed(page)))
+		return;
+
+	count = page_ref_dec_return(page);
+
+	/*
+	 * devmap page refcounts are 1-based, rather than 0-based: if
+	 * refcount is 1, then the page is free and the refcount is
+	 * stable because nobody holds a reference on the page.
+	 */
+	if (count == 1)
+		free_devmap_managed_page(page);
+	else if (!count)
+		__put_page(page);
+}
+EXPORT_SYMBOL(put_devmap_managed_page);
 #endif /* CONFIG_DEV_PAGEMAP_OPS */
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -1134,26 +1134,3 @@ void __init swap_setup(void)
 	 * _really_ don't want to cluster much more
 	 */
 }
-
-#ifdef CONFIG_DEV_PAGEMAP_OPS
-void put_devmap_managed_page(struct page *page)
-{
-	int count;
-
-	if (WARN_ON_ONCE(!page_is_devmap_managed(page)))
-		return;
-
-	count = page_ref_dec_return(page);
-
-	/*
-	 * devmap page refcounts are 1-based, rather than 0-based: if
-	 * refcount is 1, then the page is free and the refcount is
-	 * stable because nobody holds a reference on the page.
-	 */
-	if (count == 1)
-		free_devmap_managed_page(page);
-	else if (!count)
-		__put_page(page);
-}
-EXPORT_SYMBOL(put_devmap_managed_page);
-#endif