v4.19.13 snapshot.
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
new file mode 100644
index 0000000..34a2822
--- /dev/null
+++ b/include/linux/memory_hotplug.h
@@ -0,0 +1,344 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_MEMORY_HOTPLUG_H
+#define __LINUX_MEMORY_HOTPLUG_H
+
+#include <linux/mmzone.h>
+#include <linux/spinlock.h>
+#include <linux/notifier.h>
+#include <linux/bug.h>
+
+struct page;
+struct zone;
+struct pglist_data;
+struct mem_section;
+struct memory_block;
+struct resource;
+struct vmem_altmap;
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Return page for the valid pfn only if the page is online. All pfn
+ * walkers which rely on the fully initialized page->flags and others
+ * should use this rather than pfn_valid && pfn_to_page
+ */
+#define pfn_to_online_page(pfn) \
+({ \
+ struct page *___page = NULL; \
+ unsigned long ___nr = pfn_to_section_nr(pfn); \
+ \
+ if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr))\
+ ___page = pfn_to_page(pfn); \
+ ___page; \
+})
+
+/*
+ * Types for free bootmem stored in page->lru.next. These have to be in
+ * some random range in unsigned long space for debugging purposes.
+ */
+enum {
+ MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12,
+ SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
+ MIX_SECTION_INFO,
+ NODE_INFO,
+ MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
+};
+
+/* Types for control the zone type of onlined and offlined memory */
+enum {
+ MMOP_OFFLINE = -1,
+ MMOP_ONLINE_KEEP,
+ MMOP_ONLINE_KERNEL,
+ MMOP_ONLINE_MOVABLE,
+};
+
+/*
+ * Zone resizing functions
+ *
+ * Note: any attempt to resize a zone should has pgdat_resize_lock()
+ * zone_span_writelock() both held. This ensure the size of a zone
+ * can't be changed while pgdat_resize_lock() held.
+ */
+static inline unsigned zone_span_seqbegin(struct zone *zone)
+{
+ return read_seqbegin(&zone->span_seqlock);
+}
+static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
+{
+ return read_seqretry(&zone->span_seqlock, iv);
+}
+static inline void zone_span_writelock(struct zone *zone)
+{
+ write_seqlock(&zone->span_seqlock);
+}
+static inline void zone_span_writeunlock(struct zone *zone)
+{
+ write_sequnlock(&zone->span_seqlock);
+}
+static inline void zone_seqlock_init(struct zone *zone)
+{
+ seqlock_init(&zone->span_seqlock);
+}
+extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
+extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
+extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
+/* VM interface that may be used by firmware interface */
+extern int online_pages(unsigned long, unsigned long, int);
+extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long *valid_start, unsigned long *valid_end);
+extern void __offline_isolated_pages(unsigned long, unsigned long);
+
+typedef void (*online_page_callback_t)(struct page *page);
+
+extern int set_online_page_callback(online_page_callback_t callback);
+extern int restore_online_page_callback(online_page_callback_t callback);
+
+extern void __online_page_set_limits(struct page *page);
+extern void __online_page_increment_counters(struct page *page);
+extern void __online_page_free(struct page *page);
+
+extern int try_online_node(int nid);
+
+extern bool memhp_auto_online;
+/* If movable_node boot option specified */
+extern bool movable_node_enabled;
+static inline bool movable_node_is_enabled(void)
+{
+ return movable_node_enabled;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+extern int arch_remove_memory(u64 start, u64 size,
+ struct vmem_altmap *altmap);
+extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+/* reasonably generic interface to expand the physical pages */
+extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
+ struct vmem_altmap *altmap, bool want_memblock);
+
+#ifndef CONFIG_ARCH_HAS_ADD_PAGES
+static inline int add_pages(int nid, unsigned long start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap,
+ bool want_memblock)
+{
+ return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+}
+#else /* ARCH_HAS_ADD_PAGES */
+int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
+ struct vmem_altmap *altmap, bool want_memblock);
+#endif /* ARCH_HAS_ADD_PAGES */
+
+#ifdef CONFIG_NUMA
+extern int memory_add_physaddr_to_nid(u64 start);
+#else
+static inline int memory_add_physaddr_to_nid(u64 start)
+{
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
+/*
+ * For supporting node-hotadd, we have to allocate a new pgdat.
+ *
+ * If an arch has generic style NODE_DATA(),
+ * node_data[nid] = kzalloc() works well. But it depends on the architecture.
+ *
+ * In general, generic_alloc_nodedata() is used.
+ * Now, arch_free_nodedata() is just defined for error path of node_hot_add.
+ *
+ */
+extern pg_data_t *arch_alloc_nodedata(int nid);
+extern void arch_free_nodedata(pg_data_t *pgdat);
+extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
+
+#else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
+
+#define arch_alloc_nodedata(nid) generic_alloc_nodedata(nid)
+#define arch_free_nodedata(pgdat) generic_free_nodedata(pgdat)
+
+#ifdef CONFIG_NUMA
+/*
+ * If ARCH_HAS_NODEDATA_EXTENSION=n, this func is used to allocate pgdat.
+ * XXX: kmalloc_node() can't work well to get new node's memory at this time.
+ * Because, pgdat for the new node is not allocated/initialized yet itself.
+ * To use new node's memory, more consideration will be necessary.
+ */
+#define generic_alloc_nodedata(nid) \
+({ \
+ kzalloc(sizeof(pg_data_t), GFP_KERNEL); \
+})
+/*
+ * This definition is just for error path in node hotadd.
+ * For node hotremove, we have to replace this.
+ */
+#define generic_free_nodedata(pgdat) kfree(pgdat)
+
+extern pg_data_t *node_data[];
+static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
+{
+ node_data[nid] = pgdat;
+}
+
+#else /* !CONFIG_NUMA */
+
+/* never called */
+static inline pg_data_t *generic_alloc_nodedata(int nid)
+{
+ BUG();
+ return NULL;
+}
+static inline void generic_free_nodedata(pg_data_t *pgdat)
+{
+}
+static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
+{
+}
+#endif /* CONFIG_NUMA */
+#endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
+
+#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
+extern void __init register_page_bootmem_info_node(struct pglist_data *pgdat);
+#else
+static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+}
+#endif
+extern void put_page_bootmem(struct page *page);
+extern void get_page_bootmem(unsigned long ingo, struct page *page,
+ unsigned long type);
+
+void get_online_mems(void);
+void put_online_mems(void);
+
+void mem_hotplug_begin(void);
+void mem_hotplug_done(void);
+
+extern void set_zone_contiguous(struct zone *zone);
+extern void clear_zone_contiguous(struct zone *zone);
+
+#else /* ! CONFIG_MEMORY_HOTPLUG */
+#define pfn_to_online_page(pfn) \
+({ \
+ struct page *___page = NULL; \
+ if (pfn_valid(pfn)) \
+ ___page = pfn_to_page(pfn); \
+ ___page; \
+ })
+
+static inline unsigned zone_span_seqbegin(struct zone *zone)
+{
+ return 0;
+}
+static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
+{
+ return 0;
+}
+static inline void zone_span_writelock(struct zone *zone) {}
+static inline void zone_span_writeunlock(struct zone *zone) {}
+static inline void zone_seqlock_init(struct zone *zone) {}
+
+static inline int mhp_notimplemented(const char *func)
+{
+ printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
+ dump_stack();
+ return -ENOSYS;
+}
+
+static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+}
+
+static inline int try_online_node(int nid)
+{
+ return 0;
+}
+
+static inline void get_online_mems(void) {}
+static inline void put_online_mems(void) {}
+
+static inline void mem_hotplug_begin(void) {}
+static inline void mem_hotplug_done(void) {}
+
+static inline bool movable_node_is_enabled(void)
+{
+ return false;
+}
+#endif /* ! CONFIG_MEMORY_HOTPLUG */
+
+#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
+/*
+ * pgdat resizing functions
+ */
+static inline
+void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
+{
+ spin_lock_irqsave(&pgdat->node_size_lock, *flags);
+}
+static inline
+void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
+{
+ spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
+}
+static inline
+void pgdat_resize_init(struct pglist_data *pgdat)
+{
+ spin_lock_init(&pgdat->node_size_lock);
+}
+#else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
+/*
+ * Stub functions for when hotplug is off
+ */
+static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
+static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
+static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
+#endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+
+extern bool is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
+extern void try_offline_node(int nid);
+extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
+extern void remove_memory(int nid, u64 start, u64 size);
+
+#else
+static inline bool is_mem_section_removable(unsigned long pfn,
+ unsigned long nr_pages)
+{
+ return false;
+}
+
+static inline void try_offline_node(int nid) {}
+
+static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
+{
+ return -EINVAL;
+}
+
+static inline void remove_memory(int nid, u64 start, u64 size) {}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+extern void __ref free_area_init_core_hotplug(int nid);
+extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
+ void *arg, int (*func)(struct memory_block *, void *));
+extern int add_memory(int nid, u64 start, u64 size);
+extern int add_memory_resource(int nid, struct resource *resource, bool online);
+extern int arch_add_memory(int nid, u64 start, u64 size,
+ struct vmem_altmap *altmap, bool want_memblock);
+extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap);
+extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
+extern bool is_memblock_offlined(struct memory_block *mem);
+extern void remove_memory(int nid, u64 start, u64 size);
+extern int sparse_add_one_section(struct pglist_data *pgdat,
+ unsigned long start_pfn, struct vmem_altmap *altmap);
+extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
+ unsigned long map_offset, struct vmem_altmap *altmap);
+extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
+ unsigned long pnum);
+extern bool allow_online_pfn_range(int nid, unsigned long pfn, unsigned long nr_pages,
+ int online_type);
+extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
+ unsigned long nr_pages);
+#endif /* __LINUX_MEMORY_HOTPLUG_H */