Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index d4b0c79..bda2028 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -18,6 +18,8 @@
 #include <linux/pageblock-flags.h>
 #include <linux/page-flags-layout.h>
 #include <linux/atomic.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
 #include <asm/page.h>
 
 /* Free memory management - zoned buddy allocator.  */
@@ -65,7 +67,7 @@
 };
 
 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
-extern char * const migratetype_names[MIGRATE_TYPES];
+extern const char * const migratetype_names[MIGRATE_TYPES];
 
 #ifdef CONFIG_CMA
 #  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
@@ -98,6 +100,62 @@
 	unsigned long		nr_free;
 };
 
+/* Used for pages not on another list */
+static inline void add_to_free_area(struct page *page, struct free_area *area,
+			     int migratetype)
+{
+	list_add(&page->lru, &area->free_list[migratetype]);
+	area->nr_free++;
+}
+
+/* Used for pages not on another list */
+static inline void add_to_free_area_tail(struct page *page, struct free_area *area,
+				  int migratetype)
+{
+	list_add_tail(&page->lru, &area->free_list[migratetype]);
+	area->nr_free++;
+}
+
+#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
+/* Used to preserve page allocation order entropy */
+void add_to_free_area_random(struct page *page, struct free_area *area,
+		int migratetype);
+#else
+static inline void add_to_free_area_random(struct page *page,
+		struct free_area *area, int migratetype)
+{
+	add_to_free_area(page, area, migratetype);
+}
+#endif
+
+/* Used for pages which are on another list */
+static inline void move_to_free_area(struct page *page, struct free_area *area,
+			     int migratetype)
+{
+	list_move(&page->lru, &area->free_list[migratetype]);
+}
+
+static inline struct page *get_page_from_free_area(struct free_area *area,
+					    int migratetype)
+{
+	return list_first_entry_or_null(&area->free_list[migratetype],
+					struct page, lru);
+}
+
+static inline void del_page_from_free_area(struct page *page,
+		struct free_area *area)
+{
+	list_del(&page->lru);
+	__ClearPageBuddy(page);
+	set_page_private(page, 0);
+	area->nr_free--;
+}
+
+static inline bool free_area_empty(struct free_area *area, int migratetype)
+{
+	return list_empty(&area->free_list[migratetype]);
+}
+
 struct pglist_data;
 
 /*
@@ -157,12 +215,15 @@
 	NR_INACTIVE_FILE,	/*  "     "     "   "       "         */
 	NR_ACTIVE_FILE,		/*  "     "     "   "       "         */
 	NR_UNEVICTABLE,		/*  "     "     "   "       "         */
-	NR_SLAB_RECLAIMABLE,
-	NR_SLAB_UNRECLAIMABLE,
+	NR_SLAB_RECLAIMABLE,	/* Please do not reorder this item */
+	NR_SLAB_UNRECLAIMABLE,	/* and this one without looking at
+				 * memcg_flush_percpu_vmstats() first. */
 	NR_ISOLATED_ANON,	/* Temporary isolated pages from anon lru */
 	NR_ISOLATED_FILE,	/* Temporary isolated pages from file lru */
+	WORKINGSET_NODES,
 	WORKINGSET_REFAULT,
 	WORKINGSET_ACTIVATE,
+	WORKINGSET_RESTORE,
 	WORKINGSET_NODERECLAIM,
 	NR_ANON_MAPPED,	/* Mapped anonymous pages */
 	NR_FILE_MAPPED,	/* pagecache pages mapped into pagetables.
@@ -174,13 +235,15 @@
 	NR_SHMEM,		/* shmem pages (included tmpfs/GEM pages) */
 	NR_SHMEM_THPS,
 	NR_SHMEM_PMDMAPPED,
+	NR_FILE_THPS,
+	NR_FILE_PMDMAPPED,
 	NR_ANON_THPS,
 	NR_UNSTABLE_NFS,	/* NFS unstable pages */
 	NR_VMSCAN_WRITE,
 	NR_VMSCAN_IMMEDIATE,	/* Prioritise for reclaim when writeback ends */
 	NR_DIRTIED,		/* page dirtyings since bootup */
 	NR_WRITTEN,		/* page writings since bootup */
-	NR_INDIRECTLY_RECLAIMABLE_BYTES, /* measured in bytes */
+	NR_KERNEL_MISC_RECLAIMABLE,	/* reclaimable non-slab kernel pages */
 	NR_VM_NODE_STAT_ITEMS
 };
 
@@ -245,11 +308,6 @@
 #endif
 };
 
-/* Mask used at gathering information at once (see memcontrol.c) */
-#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
-#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
-#define LRU_ALL	     ((1 << NR_LRU_LISTS) - 1)
-
 /* Isolate unmapped file */
 #define ISOLATE_UNMAPPED	((__force isolate_mode_t)0x2)
 /* Isolate for asynchronous migration */
@@ -267,9 +325,10 @@
 	NR_WMARK
 };
 
-#define min_wmark_pages(z) (z->watermark[WMARK_MIN])
-#define low_wmark_pages(z) (z->watermark[WMARK_LOW])
-#define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
+#define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
+#define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
+#define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
+#define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
 
 struct per_cpu_pages {
 	int count;		/* number of pages in the list */
@@ -312,7 +371,7 @@
 	 * Architecture		Limit
 	 * ---------------------------
 	 * parisc, ia64, sparc	<4G
-	 * s390			<2G
+	 * s390, powerpc	<2G
 	 * arm			Various
 	 * alpha		Unlimited or 0-16MB.
 	 *
@@ -360,7 +419,8 @@
 	/* Read-mostly fields */
 
 	/* zone watermarks, access with *_wmark_pages(zone) macros */
-	unsigned long watermark[NR_WMARK];
+	unsigned long _watermark[NR_WMARK];
+	unsigned long watermark_boost;
 
 	unsigned long nr_reserved_highatomic;
 
@@ -426,14 +486,8 @@
 	 * Write access to present_pages at runtime should be protected by
 	 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
 	 * present_pages should get_online_mems() to get a stable value.
-	 *
-	 * Read access to managed_pages should be safe because it's unsigned
-	 * long. Write access to zone->managed_pages and totalram_pages are
-	 * protected by managed_page_count_lock at runtime. Idealy only
-	 * adjust_managed_page_count() should be used instead of directly
-	 * touching zone->managed_pages and totalram_pages.
 	 */
-	unsigned long		managed_pages;
+	atomic_long_t		managed_pages;
 	unsigned long		spanned_pages;
 	unsigned long		present_pages;
 
@@ -482,6 +536,8 @@
 	unsigned long		compact_cached_free_pfn;
 	/* pfn where async and sync compaction migration scanner should start */
 	unsigned long		compact_cached_migrate_pfn[2];
+	unsigned long		compact_init_migrate_pfn;
+	unsigned long		compact_init_free_pfn;
 #endif
 
 #ifdef CONFIG_COMPACTION
@@ -522,6 +578,17 @@
 	PGDAT_RECLAIM_LOCKED,		/* prevents concurrent reclaim */
 };
 
+enum zone_flags {
+	ZONE_BOOSTED_WATERMARK,		/* zone recently boosted watermarks.
+					 * Cleared when kswapd is woken.
+					 */
+};
+
+static inline unsigned long zone_managed_pages(struct zone *zone)
+{
+	return (unsigned long)atomic_long_read(&zone->managed_pages);
+}
+
 static inline unsigned long zone_end_pfn(const struct zone *zone)
 {
 	return zone->zone_start_pfn + zone->spanned_pages;
@@ -612,6 +679,14 @@
 extern struct page *mem_map;
 #endif
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+struct deferred_split {
+	spinlock_t split_queue_lock;
+	struct list_head split_queue;
+	unsigned long split_queue_len;
+};
+#endif
+
 /*
  * On NUMA machines, each NUMA node would have a pg_data_t to describe
  * it's memory layout. On UMA machines there is a single pglist_data which
@@ -631,14 +706,10 @@
 	struct page_ext *node_page_ext;
 #endif
 #endif
-#ifndef CONFIG_NO_BOOTMEM
-	struct bootmem_data *bdata;
-#endif
 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
 	/*
-	 * Must be held any time you expect node_start_pfn, node_present_pages
-	 * or node_spanned_pages stay constant.  Holding this will also
-	 * guarantee that any pfn_valid() stays that way.
+	 * Must be held any time you expect node_start_pfn,
+	 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
 	 *
 	 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
 	 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
@@ -692,14 +763,10 @@
 	 * is the first PFN that needs to be initialised.
 	 */
 	unsigned long first_deferred_pfn;
-	/* Number of non-deferred pages */
-	unsigned long static_init_pgcnt;
 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	spinlock_t split_queue_lock;
-	struct list_head split_queue;
-	unsigned long split_queue_len;
+	struct deferred_split deferred_split_queue;
 #endif
 
 	/* Fields commonly accessed by the page reclaim scanner */
@@ -725,10 +792,6 @@
 
 #define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)
 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
-static inline spinlock_t *zone_lru_lock(struct zone *zone)
-{
-	return &zone->zone_pgdat->lru_lock;
-}
 
 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
 {
@@ -784,6 +847,12 @@
 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
 #endif
 
+#if defined(CONFIG_SPARSEMEM)
+void memblocks_present(void);
+#else
+static inline void memblocks_present(void) {}
+#endif
+
 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
 int local_memory_node(int node_id);
 #else
@@ -795,18 +864,6 @@
  */
 #define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)
 
-#ifdef CONFIG_ZONE_DEVICE
-static inline bool is_dev_zone(const struct zone *zone)
-{
-	return zone_idx(zone) == ZONE_DEVICE;
-}
-#else
-static inline bool is_dev_zone(const struct zone *zone)
-{
-	return false;
-}
-#endif
-
 /*
  * Returns true if a zone has pages managed by the buddy allocator.
  * All the reclaim decisions have to use this function rather than
@@ -815,7 +872,7 @@
  */
 static inline bool managed_zone(struct zone *zone)
 {
-	return zone->managed_pages;
+	return zone_managed_pages(zone);
 }
 
 /* Returns true if a zone has memory */
@@ -867,7 +924,7 @@
 }
 
 /**
- * is_highmem - helper function to quickly check if a struct zone is a 
+ * is_highmem - helper function to quickly check if a struct zone is a
  *              highmem zone or not.  This is an attempt to keep references
  *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
  * @zone - pointer to struct zone variable
@@ -885,6 +942,8 @@
 struct ctl_table;
 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
 					void __user *, size_t *, loff_t *);
+int watermark_boost_factor_sysctl_handler(struct ctl_table *, int,
+					void __user *, size_t *, loff_t *);
 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
 					void __user *, size_t *, loff_t *);
 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
@@ -1098,6 +1157,29 @@
 #define SECTION_ALIGN_UP(pfn)	(((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
 #define SECTION_ALIGN_DOWN(pfn)	((pfn) & PAGE_SECTION_MASK)
 
+#define SUBSECTION_SHIFT 21
+
+#define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
+#define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
+#define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
+
+#if SUBSECTION_SHIFT > SECTION_SIZE_BITS
+#error Subsection size exceeds section size
+#else
+#define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
+#endif
+
+#define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
+#define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
+
+struct mem_section_usage {
+	DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
+	/* See declaration of similar field in struct zone */
+	unsigned long pageblock_flags[0];
+};
+
+void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
+
 struct page;
 struct page_ext;
 struct mem_section {
@@ -1115,8 +1197,7 @@
 	 */
 	unsigned long section_mem_map;
 
-	/* See declaration of similar field in struct zone */
-	unsigned long *pageblock_flags;
+	struct mem_section_usage *usage;
 #ifdef CONFIG_PAGE_EXTENSION
 	/*
 	 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
@@ -1147,6 +1228,11 @@
 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
 #endif
 
+static inline unsigned long *section_to_usemap(struct mem_section *ms)
+{
+	return ms->usage->pageblock_flags;
+}
+
 static inline struct mem_section *__nr_to_section(unsigned long nr)
 {
 #ifdef CONFIG_SPARSEMEM_EXTREME
@@ -1157,8 +1243,8 @@
 		return NULL;
 	return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 }
-extern int __section_nr(struct mem_section* ms);
-extern unsigned long usemap_size(void);
+extern unsigned long __section_nr(struct mem_section *ms);
+extern size_t mem_section_usage_size(void);
 
 /*
  * We use the lower bits of the mem_map pointer to store
@@ -1176,7 +1262,8 @@
 #define	SECTION_MARKED_PRESENT	(1UL<<0)
 #define SECTION_HAS_MEM_MAP	(1UL<<1)
 #define SECTION_IS_ONLINE	(1UL<<2)
-#define SECTION_MAP_LAST_BIT	(1UL<<3)
+#define SECTION_IS_EARLY	(1UL<<3)
+#define SECTION_MAP_LAST_BIT	(1UL<<4)
 #define SECTION_MAP_MASK	(~(SECTION_MAP_LAST_BIT-1))
 #define SECTION_NID_SHIFT	3
 
@@ -1202,6 +1289,11 @@
 	return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 }
 
+static inline int early_section(struct mem_section *section)
+{
+	return (section && (section->section_mem_map & SECTION_IS_EARLY));
+}
+
 static inline int valid_section_nr(unsigned long nr)
 {
 	return valid_section(__nr_to_section(nr));
@@ -1229,14 +1321,42 @@
 	return __nr_to_section(pfn_to_section_nr(pfn));
 }
 
-extern int __highest_present_section_nr;
+extern unsigned long __highest_present_section_nr;
+
+static inline int subsection_map_index(unsigned long pfn)
+{
+	return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
+{
+	int idx = subsection_map_index(pfn);
+
+	return test_bit(idx, ms->usage->subsection_map);
+}
+#else
+static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
+{
+	return 1;
+}
+#endif
 
 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
 static inline int pfn_valid(unsigned long pfn)
 {
+	struct mem_section *ms;
+
 	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
 		return 0;
-	return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
+	ms = __nr_to_section(pfn_to_section_nr(pfn));
+	if (!valid_section(ms))
+		return 0;
+	/*
+	 * Traditionally early sections always returned pfn_valid() for
+	 * the entire section-sized span.
+	 */
+	return early_section(ms) || pfn_section_valid(ms, pfn);
 }
 #endif
 
@@ -1267,6 +1387,8 @@
 #else
 #define sparse_init()	do {} while (0)
 #define sparse_index_init(_sec, _nid)  do {} while (0)
+#define pfn_present pfn_valid
+#define subsection_map_init(_pfn, _nr_pages) do {} while (0)
 #endif /* CONFIG_SPARSEMEM */
 
 /*
@@ -1288,7 +1410,7 @@
 
 /*
  * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
- * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
+ * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
  * pfn_valid_within() should be used in this case; we optimise this away
  * when we have no holes within a MAX_ORDER_NR_PAGES block.
  */