v4.19.13 snapshot.
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
new file mode 100644
index 0000000..10191c2
--- /dev/null
+++ b/include/linux/mm_inline.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_MM_INLINE_H
+#define LINUX_MM_INLINE_H
+
+#include <linux/huge_mm.h>
+#include <linux/swap.h>
+
+/**
+ * page_is_file_cache - should the page be on a file LRU or anon LRU?
+ * @page: the page to test
+ *
+ * Returns 1 if @page is page cache page backed by a regular filesystem,
+ * or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
+ * Used by functions that manipulate the LRU lists, to sort a page
+ * onto the right LRU list.
+ *
+ * We would like to get this info without a page flag, but the state
+ * needs to survive until the page is last deleted from the LRU, which
+ * could be as far down as __page_cache_release.
+ */
+static inline int page_is_file_cache(struct page *page)
+{
+ return !PageSwapBacked(page);
+}
+
+static __always_inline void __update_lru_size(struct lruvec *lruvec,
+ enum lru_list lru, enum zone_type zid,
+ int nr_pages)
+{
+ struct pglist_data *pgdat = lruvec_pgdat(lruvec);
+
+ __mod_node_page_state(pgdat, NR_LRU_BASE + lru, nr_pages);
+ __mod_zone_page_state(&pgdat->node_zones[zid],
+ NR_ZONE_LRU_BASE + lru, nr_pages);
+}
+
+static __always_inline void update_lru_size(struct lruvec *lruvec,
+ enum lru_list lru, enum zone_type zid,
+ int nr_pages)
+{
+ __update_lru_size(lruvec, lru, zid, nr_pages);
+#ifdef CONFIG_MEMCG
+ mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
+#endif
+}
+
+static __always_inline void add_page_to_lru_list(struct page *page,
+ struct lruvec *lruvec, enum lru_list lru)
+{
+ update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page));
+ list_add(&page->lru, &lruvec->lists[lru]);
+}
+
+static __always_inline void add_page_to_lru_list_tail(struct page *page,
+ struct lruvec *lruvec, enum lru_list lru)
+{
+ update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page));
+ list_add_tail(&page->lru, &lruvec->lists[lru]);
+}
+
+static __always_inline void del_page_from_lru_list(struct page *page,
+ struct lruvec *lruvec, enum lru_list lru)
+{
+ list_del(&page->lru);
+ update_lru_size(lruvec, lru, page_zonenum(page), -hpage_nr_pages(page));
+}
+
+/**
+ * page_lru_base_type - which LRU list type should a page be on?
+ * @page: the page to test
+ *
+ * Used for LRU list index arithmetic.
+ *
+ * Returns the base LRU type - file or anon - @page should be on.
+ */
+static inline enum lru_list page_lru_base_type(struct page *page)
+{
+ if (page_is_file_cache(page))
+ return LRU_INACTIVE_FILE;
+ return LRU_INACTIVE_ANON;
+}
+
+/**
+ * page_off_lru - which LRU list was page on? clearing its lru flags.
+ * @page: the page to test
+ *
+ * Returns the LRU list a page was on, as an index into the array of LRU
+ * lists; and clears its Unevictable or Active flags, ready for freeing.
+ */
+static __always_inline enum lru_list page_off_lru(struct page *page)
+{
+ enum lru_list lru;
+
+ if (PageUnevictable(page)) {
+ __ClearPageUnevictable(page);
+ lru = LRU_UNEVICTABLE;
+ } else {
+ lru = page_lru_base_type(page);
+ if (PageActive(page)) {
+ __ClearPageActive(page);
+ lru += LRU_ACTIVE;
+ }
+ }
+ return lru;
+}
+
+/**
+ * page_lru - which LRU list should a page be on?
+ * @page: the page to test
+ *
+ * Returns the LRU list a page should be on, as an index
+ * into the array of LRU lists.
+ */
+static __always_inline enum lru_list page_lru(struct page *page)
+{
+ enum lru_list lru;
+
+ if (PageUnevictable(page))
+ lru = LRU_UNEVICTABLE;
+ else {
+ lru = page_lru_base_type(page);
+ if (PageActive(page))
+ lru += LRU_ACTIVE;
+ }
+ return lru;
+}
+
+#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
+
+#endif