memory_hotplug.h

  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
 10struct page;
 11struct zone;
 12struct pglist_data;
 13struct mem_section;
 14struct memory_group;
 15struct resource;
 16struct vmem_altmap;
 17struct dev_pagemap;
 18
 19#ifdef CONFIG_MEMORY_HOTPLUG
 20struct page *pfn_to_online_page(unsigned long pfn);
 21
 22/* Types for control the zone type of onlined and offlined memory */
 23enum {
 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. */
 35typedef 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/*
 63 * Extended parameters for memory hotplug:
 64 * altmap: alternative allocator for memmap array (optional)
 65 * pgprot: page protection flags to apply to newly created page tables
 66 *	(required)
 67 */
 68struct mhp_params {
 69	struct vmem_altmap *altmap;
 70	pgprot_t pgprot;
 71	struct dev_pagemap *pgmap;
 72};
 73
 74bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
 75struct range mhp_get_pluggable_range(bool need_mapping);
 76bool mhp_supports_memmap_on_memory(void);
 77
 78/*
 79 * Zone resizing functions
 80 *
 81 * Note: any attempt to resize a zone should has pgdat_resize_lock()
 82 * zone_span_writelock() both held. This ensure the size of a zone
 83 * can't be changed while pgdat_resize_lock() held.
 84 */
 85static inline unsigned zone_span_seqbegin(struct zone *zone)
 86{
 87	return read_seqbegin(&zone->span_seqlock);
 88}
 89static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
 90{
 91	return read_seqretry(&zone->span_seqlock, iv);
 92}
 93static inline void zone_span_writelock(struct zone *zone)
 94{
 95	write_seqlock(&zone->span_seqlock);
 96}
 97static inline void zone_span_writeunlock(struct zone *zone)
 98{
 99	write_sequnlock(&zone->span_seqlock);
100}
101static inline void zone_seqlock_init(struct zone *zone)
102{
103	seqlock_init(&zone->span_seqlock);
104}
105extern void adjust_present_page_count(struct page *page,
106				      struct memory_group *group,
107				      long nr_pages);
108/* VM interface that may be used by firmware interface */
109extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
110				     struct zone *zone);
111extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
112extern int online_pages(unsigned long pfn, unsigned long nr_pages,
113			struct zone *zone, struct memory_group *group);
114extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
115		unsigned long end_pfn);
116
117typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
118
119extern void generic_online_page(struct page *page, unsigned int order);
120extern int set_online_page_callback(online_page_callback_t callback);
121extern int restore_online_page_callback(online_page_callback_t callback);
122
123extern int try_online_node(int nid);
124
125extern int arch_add_memory(int nid, u64 start, u64 size,
126			   struct mhp_params *params);
127extern u64 max_mem_size;
128
129extern int mhp_online_type_from_str(const char *str);
130
131/* If movable_node boot option specified */
132extern bool movable_node_enabled;
133static inline bool movable_node_is_enabled(void)
134{
135	return movable_node_enabled;
136}
137
138extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
139extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
140			   struct vmem_altmap *altmap);
141
142/* reasonably generic interface to expand the physical pages */
143extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
144		       struct mhp_params *params);
145
146#ifndef CONFIG_ARCH_HAS_ADD_PAGES
147static inline int add_pages(int nid, unsigned long start_pfn,
148		unsigned long nr_pages, struct mhp_params *params)
149{
150	return __add_pages(nid, start_pfn, nr_pages, params);
151}
152#else /* ARCH_HAS_ADD_PAGES */
153int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
154	      struct mhp_params *params);
155#endif /* ARCH_HAS_ADD_PAGES */
156
157void get_online_mems(void);
158void put_online_mems(void);
159
160void mem_hotplug_begin(void);
161void mem_hotplug_done(void);
162
163/* See kswapd_is_running() */
164static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
165{
166	mutex_lock(&pgdat->kswapd_lock);
167}
168
169static inline void pgdat_kswapd_unlock(pg_data_t *pgdat)
170{
171	mutex_unlock(&pgdat->kswapd_lock);
172}
173
174static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat)
175{
176	mutex_init(&pgdat->kswapd_lock);
177}
178
179#else /* ! CONFIG_MEMORY_HOTPLUG */
180#define pfn_to_online_page(pfn)			\
181({						\
182	struct page *___page = NULL;		\
183	if (pfn_valid(pfn))			\
184		___page = pfn_to_page(pfn);	\
185	___page;				\
186 })
187
188static inline unsigned zone_span_seqbegin(struct zone *zone)
189{
190	return 0;
191}
192static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
193{
194	return 0;
195}
196static inline void zone_span_writelock(struct zone *zone) {}
197static inline void zone_span_writeunlock(struct zone *zone) {}
198static inline void zone_seqlock_init(struct zone *zone) {}
199
200static inline int try_online_node(int nid)
201{
202	return 0;
203}
204
205static inline void get_online_mems(void) {}
206static inline void put_online_mems(void) {}
207
208static inline void mem_hotplug_begin(void) {}
209static inline void mem_hotplug_done(void) {}
210
211static inline bool movable_node_is_enabled(void)
212{
213	return false;
214}
215
216static inline bool mhp_supports_memmap_on_memory(void)
217{
218	return false;
219}
220
221static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {}
222static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {}
223static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {}
224#endif /* ! CONFIG_MEMORY_HOTPLUG */
225
226/*
227 * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
228 * platforms might override and use arch_get_mappable_range()
229 * for internal non memory hotplug purposes.
230 */
231struct range arch_get_mappable_range(void);
232
233#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
234/*
235 * pgdat resizing functions
236 */
237static inline
238void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
239{
240	spin_lock_irqsave(&pgdat->node_size_lock, *flags);
241}
242static inline
243void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
244{
245	spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
246}
247static inline
248void pgdat_resize_init(struct pglist_data *pgdat)
249{
250	spin_lock_init(&pgdat->node_size_lock);
251}
252#else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
253/*
254 * Stub functions for when hotplug is off
255 */
256static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
257static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
258static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
259#endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
260
261#ifdef CONFIG_MEMORY_HOTREMOVE
262
263extern void try_offline_node(int nid);
264extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
265			 struct zone *zone, struct memory_group *group);
266extern int remove_memory(u64 start, u64 size);
267extern void __remove_memory(u64 start, u64 size);
268extern int offline_and_remove_memory(u64 start, u64 size);
269
270#else
271static inline void try_offline_node(int nid) {}
272
273static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
274				struct zone *zone, struct memory_group *group)
275{
276	return -EINVAL;
277}
278
279static inline int remove_memory(u64 start, u64 size)
280{
281	return -EBUSY;
282}
283
284static inline void __remove_memory(u64 start, u64 size) {}
285#endif /* CONFIG_MEMORY_HOTREMOVE */
286
287#ifdef CONFIG_MEMORY_HOTPLUG
288/* Default online_type (MMOP_*) when new memory blocks are added. */
289extern int mhp_get_default_online_type(void);
290extern void mhp_set_default_online_type(int online_type);
291extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
292extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
293extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
294extern int add_memory_resource(int nid, struct resource *resource,
295			       mhp_t mhp_flags);
296extern int add_memory_driver_managed(int nid, u64 start, u64 size,
297				     const char *resource_name,
298				     mhp_t mhp_flags);
299extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
300				   unsigned long nr_pages,
301				   struct vmem_altmap *altmap, int migratetype,
302				   bool isolate_pageblock);
303extern void remove_pfn_range_from_zone(struct zone *zone,
304				       unsigned long start_pfn,
305				       unsigned long nr_pages);
306extern int sparse_add_section(int nid, unsigned long pfn,
307		unsigned long nr_pages, struct vmem_altmap *altmap,
308		struct dev_pagemap *pgmap);
309extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
310				  struct vmem_altmap *altmap);
311extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
312					  unsigned long pnum);
313extern struct zone *zone_for_pfn_range(int online_type, int nid,
314		struct memory_group *group, unsigned long start_pfn,
315		unsigned long nr_pages);
316extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
317				      struct mhp_params *params);
318void arch_remove_linear_mapping(u64 start, u64 size);
319#endif /* CONFIG_MEMORY_HOTPLUG */
320
321#endif /* __LINUX_MEMORY_HOTPLUG_H */