v4.19.13 snapshot.
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
new file mode 100644
index 0000000..4ae347c
--- /dev/null
+++ b/include/linux/page-isolation.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_PAGEISOLATION_H
+#define __LINUX_PAGEISOLATION_H
+
+#ifdef CONFIG_MEMORY_ISOLATION
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+	return zone->nr_isolate_pageblock;
+}
+static inline bool is_migrate_isolate_page(struct page *page)
+{
+	return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
+}
+static inline bool is_migrate_isolate(int migratetype)
+{
+	return migratetype == MIGRATE_ISOLATE;
+}
+#else
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+	return false;
+}
+static inline bool is_migrate_isolate_page(struct page *page)
+{
+	return false;
+}
+static inline bool is_migrate_isolate(int migratetype)
+{
+	return false;
+}
+#endif
+
+bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
+			 int migratetype, bool skip_hwpoisoned_pages);
+void set_pageblock_migratetype(struct page *page, int migratetype);
+int move_freepages_block(struct zone *zone, struct page *page,
+				int migratetype, int *num_movable);
+
+/*
+ * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
+ * If specified range includes migrate types other than MOVABLE or CMA,
+ * this will fail with -EBUSY.
+ *
+ * For isolating all pages in the range finally, the caller have to
+ * free all pages in the range. test_page_isolated() can be used for
+ * test it.
+ */
+int
+start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
+			 unsigned migratetype, bool skip_hwpoisoned_pages);
+
+/*
+ * Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE.
+ * target range is [start_pfn, end_pfn)
+ */
+int
+undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
+			unsigned migratetype);
+
+/*
+ * Test all pages in [start_pfn, end_pfn) are isolated or not.
+ */
+int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
+			bool skip_hwpoisoned_pages);
+
+struct page *alloc_migrate_target(struct page *page, unsigned long private);
+
+#endif