[linux-2.6-block.git] / include / linux / memory_hotplug.h

/* 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_group;
struct resource;
struct vmem_altmap;
struct dev_pagemap;

#ifdef CONFIG_MEMORY_HOTPLUG
struct page *pfn_to_online_page(unsigned long pfn);

/* Types for control the zone type of onlined and offlined memory */
enum {
	/* Offline the memory. */
	MMOP_OFFLINE = 0,
	/* Online the memory. Zone depends, see default_zone_for_pfn(). */
	MMOP_ONLINE,
	/* Online the memory to ZONE_NORMAL. */
	MMOP_ONLINE_KERNEL,
	/* Online the memory to ZONE_MOVABLE. */
	MMOP_ONLINE_MOVABLE,
};

/* Flags for add_memory() and friends to specify memory hotplug details. */
typedef int __bitwise mhp_t;

/* No special request */
#define MHP_NONE		((__force mhp_t)0)
/*
 * Allow merging of the added System RAM resource with adjacent,
 * mergeable resources. After a successful call to add_memory_resource()
 * with this flag set, the resource pointer must no longer be used as it
 * might be stale, or the resource might have changed.
 */
#define MHP_MERGE_RESOURCE	((__force mhp_t)BIT(0))

/*
 * We want memmap (struct page array) to be self contained.
 * To do so, we will use the beginning of the hot-added range to build
 * the page tables for the memmap array that describes the entire range.
 * Only selected architectures support it with SPARSE_VMEMMAP.
 * This is only a hint, the core kernel can decide to not do this based on
 * different alignment checks.
 */
#define MHP_MEMMAP_ON_MEMORY   ((__force mhp_t)BIT(1))
/*
 * The nid field specifies a memory group id (mgid) instead. The memory group
 * implies the node id (nid).
 */
#define MHP_NID_IS_MGID		((__force mhp_t)BIT(2))
/*
 * The hotplugged memory is completely inaccessible while the memory is
 * offline. The memory provider will handle MEM_PREPARE_ONLINE /
 * MEM_FINISH_OFFLINE notifications and make the memory accessible.
 *
 * This flag is only relevant when used along with MHP_MEMMAP_ON_MEMORY,
 * because the altmap cannot be written (e.g., poisoned) when adding
 * memory -- before it is set online.
 *
 * This allows for adding memory with an altmap that is not currently
 * made available by a hypervisor. When onlining that memory, the
 * hypervisor can be instructed to make that memory available, and
 * the onlining phase will not require any memory allocations, which is
 * helpful in low-memory situations.
 */
#define MHP_OFFLINE_INACCESSIBLE	((__force mhp_t)BIT(3))

/*
 * Extended parameters for memory hotplug:
 * altmap: alternative allocator for memmap array (optional)
 * pgprot: page protection flags to apply to newly created page tables
 *	(required)
 */
struct mhp_params {
	struct vmem_altmap *altmap;
	pgprot_t pgprot;
	struct dev_pagemap *pgmap;
};

bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
struct range mhp_get_pluggable_range(bool need_mapping);
bool mhp_supports_memmap_on_memory(void);

/*
 * 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 void adjust_present_page_count(struct page *page,
				      struct memory_group *group,
				      long nr_pages);
/* VM interface that may be used by firmware interface */
extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
				     struct zone *zone, bool mhp_off_inaccessible);
extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
extern int online_pages(unsigned long pfn, unsigned long nr_pages,
			struct zone *zone, struct memory_group *group);
extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
		unsigned long end_pfn);

typedef void (*online_page_callback_t)(struct page *page, unsigned int order);

extern void generic_online_page(struct page *page, unsigned int order);
extern int set_online_page_callback(online_page_callback_t callback);
extern int restore_online_page_callback(online_page_callback_t callback);

extern int try_online_node(int nid);

extern int arch_add_memory(int nid, u64 start, u64 size,
			   struct mhp_params *params);
extern u64 max_mem_size;

extern int mhp_online_type_from_str(const char *str);

/* If movable_node boot option specified */
extern bool movable_node_enabled;
static inline bool movable_node_is_enabled(void)
{
	return movable_node_enabled;
}

extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
			   struct vmem_altmap *altmap);

/* reasonably generic interface to expand the physical pages */
extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
		       struct mhp_params *params);

#ifndef CONFIG_ARCH_HAS_ADD_PAGES
static inline int add_pages(int nid, unsigned long start_pfn,
		unsigned long nr_pages, struct mhp_params *params)
{
	return __add_pages(nid, start_pfn, nr_pages, params);
}
#else /* ARCH_HAS_ADD_PAGES */
int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
	      struct mhp_params *params);
#endif /* ARCH_HAS_ADD_PAGES */

void get_online_mems(void);
void put_online_mems(void);

void mem_hotplug_begin(void);
void mem_hotplug_done(void);

/* See kswapd_is_running() */
static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
{
	mutex_lock(&pgdat->kswapd_lock);
}

static inline void pgdat_kswapd_unlock(pg_data_t *pgdat)
{
	mutex_unlock(&pgdat->kswapd_lock);
}

static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat)
{
	mutex_init(&pgdat->kswapd_lock);
}

#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 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;
}

static inline bool mhp_supports_memmap_on_memory(void)
{
	return false;
}

static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {}
static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {}
static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {}
#endif /* ! CONFIG_MEMORY_HOTPLUG */

/*
 * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
 * platforms might override and use arch_get_mappable_range()
 * for internal non memory hotplug purposes.
 */
struct range arch_get_mappable_range(void);

#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 void try_offline_node(int nid);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
			 struct zone *zone, struct memory_group *group);
extern int remove_memory(u64 start, u64 size);
extern void __remove_memory(u64 start, u64 size);
extern int offline_and_remove_memory(u64 start, u64 size);

#else
static inline void try_offline_node(int nid) {}

static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
				struct zone *zone, struct memory_group *group)
{
	return -EINVAL;
}

static inline int remove_memory(u64 start, u64 size)
{
	return -EBUSY;
}

static inline void __remove_memory(u64 start, u64 size) {}
#endif /* CONFIG_MEMORY_HOTREMOVE */

#ifdef CONFIG_MEMORY_HOTPLUG
/* Default online_type (MMOP_*) when new memory blocks are added. */
extern int mhp_get_default_online_type(void);
extern void mhp_set_default_online_type(int online_type);
extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
extern int add_memory_resource(int nid, struct resource *resource,
			       mhp_t mhp_flags);
extern int add_memory_driver_managed(int nid, u64 start, u64 size,
				     const char *resource_name,
				     mhp_t mhp_flags);
extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
				   unsigned long nr_pages,
				   struct vmem_altmap *altmap, int migratetype);
extern void remove_pfn_range_from_zone(struct zone *zone,
				       unsigned long start_pfn,
				       unsigned long nr_pages);
extern int sparse_add_section(int nid, unsigned long pfn,
		unsigned long nr_pages, struct vmem_altmap *altmap,
		struct dev_pagemap *pgmap);
extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
				  struct vmem_altmap *altmap);
extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
					  unsigned long pnum);
extern struct zone *zone_for_pfn_range(int online_type, int nid,
		struct memory_group *group, unsigned long start_pfn,
		unsigned long nr_pages);
extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
				      struct mhp_params *params);
void arch_remove_linear_mapping(u64 start, u64 size);
#endif /* CONFIG_MEMORY_HOTPLUG */

#endif /* __LINUX_MEMORY_HOTPLUG_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef __LINUX_MEMORY_HOTPLUG_H
	3	#define __LINUX_MEMORY_HOTPLUG_H
	4
	5	#include <linux/mmzone.h>
	6	#include <linux/spinlock.h>
	7	#include <linux/notifier.h>
	8	#include <linux/bug.h>
	9
	10	struct page;
	11	struct zone;
	12	struct pglist_data;
	13	struct mem_section;
	14	struct memory_group;
	15	struct resource;
	16	struct vmem_altmap;
	17	struct dev_pagemap;
	18
	19	#ifdef CONFIG_MEMORY_HOTPLUG
	20	struct page *pfn_to_online_page(unsigned long pfn);
	21
	22	/* Types for control the zone type of onlined and offlined memory */
	23	enum {
	24	/* Offline the memory. */
	25	MMOP_OFFLINE = 0,
	26	/* Online the memory. Zone depends, see default_zone_for_pfn(). */
	27	MMOP_ONLINE,
	28	/* Online the memory to ZONE_NORMAL. */
	29	MMOP_ONLINE_KERNEL,
	30	/* Online the memory to ZONE_MOVABLE. */
	31	MMOP_ONLINE_MOVABLE,
	32	};
	33
	34	/* Flags for add_memory() and friends to specify memory hotplug details. */
	35	typedef int __bitwise mhp_t;
	36
	37	/* No special request */
	38	#define MHP_NONE ((__force mhp_t)0)
	39	/*
	40	* Allow merging of the added System RAM resource with adjacent,
	41	* mergeable resources. After a successful call to add_memory_resource()
	42	* with this flag set, the resource pointer must no longer be used as it
	43	* might be stale, or the resource might have changed.
	44	*/
	45	#define MHP_MERGE_RESOURCE ((__force mhp_t)BIT(0))
	46
	47	/*
	48	* We want memmap (struct page array) to be self contained.
	49	* To do so, we will use the beginning of the hot-added range to build
	50	* the page tables for the memmap array that describes the entire range.
	51	* Only selected architectures support it with SPARSE_VMEMMAP.
	52	* This is only a hint, the core kernel can decide to not do this based on
	53	* different alignment checks.
	54	*/
	55	#define MHP_MEMMAP_ON_MEMORY ((__force mhp_t)BIT(1))
	56	/*
	57	* The nid field specifies a memory group id (mgid) instead. The memory group
	58	* implies the node id (nid).
	59	*/
	60	#define MHP_NID_IS_MGID ((__force mhp_t)BIT(2))
	61	/*
	62	* The hotplugged memory is completely inaccessible while the memory is
	63	* offline. The memory provider will handle MEM_PREPARE_ONLINE /
	64	* MEM_FINISH_OFFLINE notifications and make the memory accessible.
	65	*
	66	* This flag is only relevant when used along with MHP_MEMMAP_ON_MEMORY,
	67	* because the altmap cannot be written (e.g., poisoned) when adding
	68	* memory -- before it is set online.
	69	*
	70	* This allows for adding memory with an altmap that is not currently
	71	* made available by a hypervisor. When onlining that memory, the
	72	* hypervisor can be instructed to make that memory available, and
	73	* the onlining phase will not require any memory allocations, which is
	74	* helpful in low-memory situations.
	75	*/
	76	#define MHP_OFFLINE_INACCESSIBLE ((__force mhp_t)BIT(3))
	77
	78	/*
	79	* Extended parameters for memory hotplug:
	80	* altmap: alternative allocator for memmap array (optional)
	81	* pgprot: page protection flags to apply to newly created page tables
	82	* (required)
	83	*/
	84	struct mhp_params {
	85	struct vmem_altmap *altmap;
	86	pgprot_t pgprot;
	87	struct dev_pagemap *pgmap;
	88	};
	89
	90	bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
	91	struct range mhp_get_pluggable_range(bool need_mapping);
	92	bool mhp_supports_memmap_on_memory(void);
	93
	94	/*
	95	* Zone resizing functions
	96	*
	97	* Note: any attempt to resize a zone should has pgdat_resize_lock()
	98	* zone_span_writelock() both held. This ensure the size of a zone
	99	* can't be changed while pgdat_resize_lock() held.
	100	*/
	101	static inline unsigned zone_span_seqbegin(struct zone *zone)
	102	{
	103	return read_seqbegin(&zone->span_seqlock);
	104	}
	105	static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
	106	{
	107	return read_seqretry(&zone->span_seqlock, iv);
	108	}
	109	static inline void zone_span_writelock(struct zone *zone)
	110	{
	111	write_seqlock(&zone->span_seqlock);
	112	}
	113	static inline void zone_span_writeunlock(struct zone *zone)
	114	{
	115	write_sequnlock(&zone->span_seqlock);
	116	}
	117	static inline void zone_seqlock_init(struct zone *zone)
	118	{
	119	seqlock_init(&zone->span_seqlock);
	120	}
	121	extern void adjust_present_page_count(struct page *page,
	122	struct memory_group *group,
	123	long nr_pages);
	124	/* VM interface that may be used by firmware interface */
	125	extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
	126	struct zone *zone, bool mhp_off_inaccessible);
	127	extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
	128	extern int online_pages(unsigned long pfn, unsigned long nr_pages,
	129	struct zone zone, struct memory_group group);
	130	extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
	131	unsigned long end_pfn);
	132
	133	typedef void (online_page_callback_t)(struct page page, unsigned int order);
	134
	135	extern void generic_online_page(struct page *page, unsigned int order);
	136	extern int set_online_page_callback(online_page_callback_t callback);
	137	extern int restore_online_page_callback(online_page_callback_t callback);
	138
	139	extern int try_online_node(int nid);
	140
	141	extern int arch_add_memory(int nid, u64 start, u64 size,
	142	struct mhp_params *params);
	143	extern u64 max_mem_size;
	144
	145	extern int mhp_online_type_from_str(const char *str);
	146
	147	/* If movable_node boot option specified */
	148	extern bool movable_node_enabled;
	149	static inline bool movable_node_is_enabled(void)
	150	{
	151	return movable_node_enabled;
	152	}
	153
	154	extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
	155	extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
	156	struct vmem_altmap *altmap);
	157
	158	/* reasonably generic interface to expand the physical pages */
	159	extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
	160	struct mhp_params *params);
	161
	162	#ifndef CONFIG_ARCH_HAS_ADD_PAGES
	163	static inline int add_pages(int nid, unsigned long start_pfn,
	164	unsigned long nr_pages, struct mhp_params *params)
	165	{
	166	return __add_pages(nid, start_pfn, nr_pages, params);
	167	}
	168	#else /* ARCH_HAS_ADD_PAGES */
	169	int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
	170	struct mhp_params *params);
	171	#endif /* ARCH_HAS_ADD_PAGES */
	172
	173	void get_online_mems(void);
	174	void put_online_mems(void);
	175
	176	void mem_hotplug_begin(void);
	177	void mem_hotplug_done(void);
	178
	179	/* See kswapd_is_running() */
	180	static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
	181	{
	182	mutex_lock(&pgdat->kswapd_lock);
	183	}
	184
	185	static inline void pgdat_kswapd_unlock(pg_data_t *pgdat)
	186	{
	187	mutex_unlock(&pgdat->kswapd_lock);
	188	}
	189
	190	static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat)
	191	{
	192	mutex_init(&pgdat->kswapd_lock);
	193	}
	194
	195	#else /* ! CONFIG_MEMORY_HOTPLUG */
	196	#define pfn_to_online_page(pfn) \
	197	({ \
	198	struct page *___page = NULL; \
	199	if (pfn_valid(pfn)) \
	200	___page = pfn_to_page(pfn); \
	201	___page; \
	202	})
	203
	204	static inline unsigned zone_span_seqbegin(struct zone *zone)
	205	{
	206	return 0;
	207	}
	208	static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
	209	{
	210	return 0;
	211	}
	212	static inline void zone_span_writelock(struct zone *zone) {}
	213	static inline void zone_span_writeunlock(struct zone *zone) {}
	214	static inline void zone_seqlock_init(struct zone *zone) {}
	215
	216	static inline int try_online_node(int nid)
	217	{
	218	return 0;
	219	}
	220
	221	static inline void get_online_mems(void) {}
	222	static inline void put_online_mems(void) {}
	223
	224	static inline void mem_hotplug_begin(void) {}
	225	static inline void mem_hotplug_done(void) {}
	226
	227	static inline bool movable_node_is_enabled(void)
	228	{
	229	return false;
	230	}
	231
	232	static inline bool mhp_supports_memmap_on_memory(void)
	233	{
	234	return false;
	235	}
	236
	237	static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {}
	238	static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {}
	239	static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {}
	240	#endif /* ! CONFIG_MEMORY_HOTPLUG */
	241
	242	/*
	243	* Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
	244	* platforms might override and use arch_get_mappable_range()
	245	* for internal non memory hotplug purposes.
	246	*/
	247	struct range arch_get_mappable_range(void);
	248
	249	#if defined(CONFIG_MEMORY_HOTPLUG) \|\| defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
	250	/*
	251	* pgdat resizing functions
	252	*/
	253	static inline
	254	void pgdat_resize_lock(struct pglist_data pgdat, unsigned long flags)
	255	{
	256	spin_lock_irqsave(&pgdat->node_size_lock, *flags);
	257	}
	258	static inline
	259	void pgdat_resize_unlock(struct pglist_data pgdat, unsigned long flags)
	260	{
	261	spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
	262	}
	263	static inline
	264	void pgdat_resize_init(struct pglist_data *pgdat)
	265	{
	266	spin_lock_init(&pgdat->node_size_lock);
	267	}
	268	#else /* !(CONFIG_MEMORY_HOTPLUG \|\| CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
	269	/*
	270	* Stub functions for when hotplug is off
	271	*/
	272	static inline void pgdat_resize_lock(struct pglist_data p, unsigned long f) {}
	273	static inline void pgdat_resize_unlock(struct pglist_data p, unsigned long f) {}
	274	static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
	275	#endif /* !(CONFIG_MEMORY_HOTPLUG \|\| CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
	276
	277	#ifdef CONFIG_MEMORY_HOTREMOVE
	278
	279	extern void try_offline_node(int nid);
	280	extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
	281	struct zone zone, struct memory_group group);
	282	extern int remove_memory(u64 start, u64 size);
	283	extern void __remove_memory(u64 start, u64 size);
	284	extern int offline_and_remove_memory(u64 start, u64 size);
	285
	286	#else
	287	static inline void try_offline_node(int nid) {}
	288
	289	static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
	290	struct zone zone, struct memory_group group)
	291	{
	292	return -EINVAL;
	293	}
	294
	295	static inline int remove_memory(u64 start, u64 size)
	296	{
	297	return -EBUSY;
	298	}
	299
	300	static inline void __remove_memory(u64 start, u64 size) {}
	301	#endif /* CONFIG_MEMORY_HOTREMOVE */
	302
	303	#ifdef CONFIG_MEMORY_HOTPLUG
	304	/* Default online_type (MMOP_) when new memory blocks are added. /
	305	extern int mhp_get_default_online_type(void);
	306	extern void mhp_set_default_online_type(int online_type);
	307	extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
	308	extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
	309	extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
	310	extern int add_memory_resource(int nid, struct resource *resource,
	311	mhp_t mhp_flags);
	312	extern int add_memory_driver_managed(int nid, u64 start, u64 size,
	313	const char *resource_name,
	314	mhp_t mhp_flags);
	315	extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
	316	unsigned long nr_pages,
	317	struct vmem_altmap *altmap, int migratetype);
	318	extern void remove_pfn_range_from_zone(struct zone *zone,
	319	unsigned long start_pfn,
	320	unsigned long nr_pages);
	321	extern int sparse_add_section(int nid, unsigned long pfn,
	322	unsigned long nr_pages, struct vmem_altmap *altmap,
	323	struct dev_pagemap *pgmap);
	324	extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
	325	struct vmem_altmap *altmap);
	326	extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
	327	unsigned long pnum);
	328	extern struct zone *zone_for_pfn_range(int online_type, int nid,
	329	struct memory_group *group, unsigned long start_pfn,
	330	unsigned long nr_pages);
	331	extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
	332	struct mhp_params *params);
	333	void arch_remove_linear_mapping(u64 start, u64 size);
	334	#endif /* CONFIG_MEMORY_HOTPLUG */
	335
	336	#endif /* __LINUX_MEMORY_HOTPLUG_H */