powerpc/pseries/cmm: remove cmm_balloon_compaction_init()

Now that there is not a lot of logic left, let's just inline setting up
the migration function.

To avoid #ifdef in the caller we can instead use IS_ENABLED() and make the
compiler happy by only providing the function declaration.

Now that the function is gone, drop the "out_balloon_compaction" label. 
Note that before commit 68f2736a8583 ("mm: Convert all PageMovable users
to movable_operations") we actually had to undo something, now not
anymore.

Link: https://lkml.kernel.org/r/20260119230133.3551867-4-david@kernel.org
Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 5 insertions, 11 deletions

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 4cbbe2ee58ab..9a6efbc80d2a 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -548,15 +548,9 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 	return 0;
 }
-
-static void cmm_balloon_compaction_init(void)
-{
-	b_dev_info.migratepage = cmm_migratepage;
-}
 #else /* CONFIG_BALLOON_COMPACTION */
-static void cmm_balloon_compaction_init(void)
-{
-}
+int cmm_migratepage(struct balloon_dev_info *b_dev_info, struct page *newpage,
+		    struct page *page, enum migrate_mode mode);
 #endif /* CONFIG_BALLOON_COMPACTION */
 
 /**
@@ -573,11 +567,12 @@ static int cmm_init(void)
 		return -EOPNOTSUPP;
 
 	balloon_devinfo_init(&b_dev_info);
-	cmm_balloon_compaction_init();
+	if (IS_ENABLED(CONFIG_BALLOON_COMPACTION))
+		b_dev_info.migratepage = cmm_migratepage;
 
 	rc = register_oom_notifier(&cmm_oom_nb);
 	if (rc < 0)
-		goto out_balloon_compaction;
+		return rc;
 
 	if ((rc = register_reboot_notifier(&cmm_reboot_nb)))
 		goto out_oom_notifier;
@@ -606,7 +601,6 @@ out_reboot_notifier:
 	unregister_reboot_notifier(&cmm_reboot_nb);
 out_oom_notifier:
 	unregister_oom_notifier(&cmm_oom_nb);
-out_balloon_compaction:
 	return rc;
 }