From 19855bbeb7d53b0eaf69df5b32bde838f5a7e31b Mon Sep 17 00:00:00 2001
From: Chris von Recklinghausen <crecklin@redhat.com>
Date: Wed, 12 Oct 2022 07:09:00 -0400
Subject: [PATCH] mm: refactor the ZONE_DEVICE handling in migrate_vma_pages

Bugzilla: https://bugzilla.redhat.com/2120352
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2099722

commit aaf7d70cc595c78d27e915451e93a4459cfc36f3
Author: Christoph Hellwig <hch@lst.de>
Date:   Wed Feb 16 15:31:37 2022 +1100

    mm: refactor the ZONE_DEVICE handling in migrate_vma_pages

    Make the flow a little more clear and prepare for adding a new
    ZONE_DEVICE memory type.

    Link: https://lkml.kernel.org/r/20220210072828.2930359-13-hch@lst.de
    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Reviewed-by: Alistair Popple <apopple@nvidia.com>
    Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

    Cc: Alex Deucher <alexander.deucher@amd.com>
    Cc: Ben Skeggs <bskeggs@redhat.com>
    Cc: Chaitanya Kulkarni <kch@nvidia.com>
    Cc: Christian Knig <christian.koenig@amd.com>
    Cc: Dan Williams <dan.j.williams@intel.com>
    Cc: Felix Kuehling <Felix.Kuehling@amd.com>
    Cc: Jason Gunthorpe <jgg@nvidia.com>
    Cc: Karol Herbst <kherbst@redhat.com>
    Cc: Logan Gunthorpe <logang@deltatee.com>
    Cc: Lyude Paul <lyude@redhat.com>
    Cc: Miaohe Lin <linmiaohe@huawei.com>
    Cc: Muchun Song <songmuchun@bytedance.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: Chris von Recklinghausen <crecklin@redhat.com>
---
 mm/migrate.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 214c0c11f9ae..08e6b8ee3854 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2769,24 +2769,21 @@ void migrate_vma_pages(struct migrate_vma *migrate)
 
 		mapping = page_mapping(page);
 
-		if (is_zone_device_page(newpage)) {
-			if (is_device_private_page(newpage)) {
-				/*
-				 * For now only support private anonymous when
-				 * migrating to un-addressable device memory.
-				 */
-				if (mapping) {
-					migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
-					continue;
-				}
-			} else {
-				/*
-				 * Other types of ZONE_DEVICE page are not
-				 * supported.
-				 */
+		if (is_device_private_page(newpage)) {
+			/*
+			 * For now only support private anonymous when migrating
+			 * to un-addressable device memory.
+			 */
+			if (mapping) {
 				migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
 				continue;
 			}
+		} else if (is_zone_device_page(newpage)) {
+			/*
+			 * Other types of ZONE_DEVICE page are not supported.
+			 */
+			migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
+			continue;
 		}
 
 		r = migrate_page(mapping, newpage, page, MIGRATE_SYNC_NO_COPY);