xref: /linux-6.15/include/linux/memory_hotplug.h (revision 70b5b46a)
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_block;
15 struct memory_group;
16 struct resource;
17 struct vmem_altmap;
18 
19 #ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
20 /*
21  * For supporting node-hotadd, we have to allocate a new pgdat.
22  *
23  * If an arch has generic style NODE_DATA(),
24  * node_data[nid] = kzalloc() works well. But it depends on the architecture.
25  *
26  * In general, generic_alloc_nodedata() is used.
27  *
28  */
29 extern pg_data_t *arch_alloc_nodedata(int nid);
30 extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
31 
32 #else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
33 
34 #define arch_alloc_nodedata(nid)	generic_alloc_nodedata(nid)
35 
36 #ifdef CONFIG_NUMA
37 /*
38  * XXX: node aware allocation can't work well to get new node's memory at this time.
39  *	Because, pgdat for the new node is not allocated/initialized yet itself.
40  *	To use new node's memory, more consideration will be necessary.
41  */
42 #define generic_alloc_nodedata(nid)				\
43 ({								\
44 	memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES);	\
45 })
46 /*
47  * This definition is just for error path in node hotadd.
48  * For node hotremove, we have to replace this.
49  */
50 #define generic_free_nodedata(pgdat)	kfree(pgdat)
51 
52 extern pg_data_t *node_data[];
53 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
54 {
55 	node_data[nid] = pgdat;
56 }
57 
58 #else /* !CONFIG_NUMA */
59 
60 /* never called */
61 static inline pg_data_t *generic_alloc_nodedata(int nid)
62 {
63 	BUG();
64 	return NULL;
65 }
66 static inline void generic_free_nodedata(pg_data_t *pgdat)
67 {
68 }
69 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
70 {
71 }
72 #endif /* CONFIG_NUMA */
73 #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
74 
75 #ifdef CONFIG_MEMORY_HOTPLUG
76 struct page *pfn_to_online_page(unsigned long pfn);
77 
78 /* Types for control the zone type of onlined and offlined memory */
79 enum {
80 	/* Offline the memory. */
81 	MMOP_OFFLINE = 0,
82 	/* Online the memory. Zone depends, see default_zone_for_pfn(). */
83 	MMOP_ONLINE,
84 	/* Online the memory to ZONE_NORMAL. */
85 	MMOP_ONLINE_KERNEL,
86 	/* Online the memory to ZONE_MOVABLE. */
87 	MMOP_ONLINE_MOVABLE,
88 };
89 
90 /* Flags for add_memory() and friends to specify memory hotplug details. */
91 typedef int __bitwise mhp_t;
92 
93 /* No special request */
94 #define MHP_NONE		((__force mhp_t)0)
95 /*
96  * Allow merging of the added System RAM resource with adjacent,
97  * mergeable resources. After a successful call to add_memory_resource()
98  * with this flag set, the resource pointer must no longer be used as it
99  * might be stale, or the resource might have changed.
100  */
101 #define MHP_MERGE_RESOURCE	((__force mhp_t)BIT(0))
102 
103 /*
104  * We want memmap (struct page array) to be self contained.
105  * To do so, we will use the beginning of the hot-added range to build
106  * the page tables for the memmap array that describes the entire range.
107  * Only selected architectures support it with SPARSE_VMEMMAP.
108  */
109 #define MHP_MEMMAP_ON_MEMORY   ((__force mhp_t)BIT(1))
110 /*
111  * The nid field specifies a memory group id (mgid) instead. The memory group
112  * implies the node id (nid).
113  */
114 #define MHP_NID_IS_MGID		((__force mhp_t)BIT(2))
115 
116 /*
117  * Extended parameters for memory hotplug:
118  * altmap: alternative allocator for memmap array (optional)
119  * pgprot: page protection flags to apply to newly created page tables
120  *	(required)
121  */
122 struct mhp_params {
123 	struct vmem_altmap *altmap;
124 	pgprot_t pgprot;
125 };
126 
127 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
128 struct range mhp_get_pluggable_range(bool need_mapping);
129 
130 /*
131  * Zone resizing functions
132  *
133  * Note: any attempt to resize a zone should has pgdat_resize_lock()
134  * zone_span_writelock() both held. This ensure the size of a zone
135  * can't be changed while pgdat_resize_lock() held.
136  */
137 static inline unsigned zone_span_seqbegin(struct zone *zone)
138 {
139 	return read_seqbegin(&zone->span_seqlock);
140 }
141 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
142 {
143 	return read_seqretry(&zone->span_seqlock, iv);
144 }
145 static inline void zone_span_writelock(struct zone *zone)
146 {
147 	write_seqlock(&zone->span_seqlock);
148 }
149 static inline void zone_span_writeunlock(struct zone *zone)
150 {
151 	write_sequnlock(&zone->span_seqlock);
152 }
153 static inline void zone_seqlock_init(struct zone *zone)
154 {
155 	seqlock_init(&zone->span_seqlock);
156 }
157 extern void adjust_present_page_count(struct page *page,
158 				      struct memory_group *group,
159 				      long nr_pages);
160 /* VM interface that may be used by firmware interface */
161 extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
162 				     struct zone *zone);
163 extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
164 extern int online_pages(unsigned long pfn, unsigned long nr_pages,
165 			struct zone *zone, struct memory_group *group);
166 extern struct zone *test_pages_in_a_zone(unsigned long start_pfn,
167 					 unsigned long end_pfn);
168 extern void __offline_isolated_pages(unsigned long start_pfn,
169 				     unsigned long end_pfn);
170 
171 typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
172 
173 extern void generic_online_page(struct page *page, unsigned int order);
174 extern int set_online_page_callback(online_page_callback_t callback);
175 extern int restore_online_page_callback(online_page_callback_t callback);
176 
177 extern int try_online_node(int nid);
178 
179 extern int arch_add_memory(int nid, u64 start, u64 size,
180 			   struct mhp_params *params);
181 extern u64 max_mem_size;
182 
183 extern int mhp_online_type_from_str(const char *str);
184 
185 /* Default online_type (MMOP_*) when new memory blocks are added. */
186 extern int mhp_default_online_type;
187 /* If movable_node boot option specified */
188 extern bool movable_node_enabled;
189 static inline bool movable_node_is_enabled(void)
190 {
191 	return movable_node_enabled;
192 }
193 
194 extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
195 extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
196 			   struct vmem_altmap *altmap);
197 
198 /* reasonably generic interface to expand the physical pages */
199 extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
200 		       struct mhp_params *params);
201 
202 #ifndef CONFIG_ARCH_HAS_ADD_PAGES
203 static inline int add_pages(int nid, unsigned long start_pfn,
204 		unsigned long nr_pages, struct mhp_params *params)
205 {
206 	return __add_pages(nid, start_pfn, nr_pages, params);
207 }
208 #else /* ARCH_HAS_ADD_PAGES */
209 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
210 	      struct mhp_params *params);
211 #endif /* ARCH_HAS_ADD_PAGES */
212 
213 void get_online_mems(void);
214 void put_online_mems(void);
215 
216 void mem_hotplug_begin(void);
217 void mem_hotplug_done(void);
218 
219 #else /* ! CONFIG_MEMORY_HOTPLUG */
220 #define pfn_to_online_page(pfn)			\
221 ({						\
222 	struct page *___page = NULL;		\
223 	if (pfn_valid(pfn))			\
224 		___page = pfn_to_page(pfn);	\
225 	___page;				\
226  })
227 
228 static inline unsigned zone_span_seqbegin(struct zone *zone)
229 {
230 	return 0;
231 }
232 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
233 {
234 	return 0;
235 }
236 static inline void zone_span_writelock(struct zone *zone) {}
237 static inline void zone_span_writeunlock(struct zone *zone) {}
238 static inline void zone_seqlock_init(struct zone *zone) {}
239 
240 static inline int try_online_node(int nid)
241 {
242 	return 0;
243 }
244 
245 static inline void get_online_mems(void) {}
246 static inline void put_online_mems(void) {}
247 
248 static inline void mem_hotplug_begin(void) {}
249 static inline void mem_hotplug_done(void) {}
250 
251 static inline bool movable_node_is_enabled(void)
252 {
253 	return false;
254 }
255 #endif /* ! CONFIG_MEMORY_HOTPLUG */
256 
257 /*
258  * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
259  * platforms might override and use arch_get_mappable_range()
260  * for internal non memory hotplug purposes.
261  */
262 struct range arch_get_mappable_range(void);
263 
264 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
265 /*
266  * pgdat resizing functions
267  */
268 static inline
269 void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
270 {
271 	spin_lock_irqsave(&pgdat->node_size_lock, *flags);
272 }
273 static inline
274 void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
275 {
276 	spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
277 }
278 static inline
279 void pgdat_resize_init(struct pglist_data *pgdat)
280 {
281 	spin_lock_init(&pgdat->node_size_lock);
282 }
283 #else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
284 /*
285  * Stub functions for when hotplug is off
286  */
287 static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
288 static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
289 static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
290 #endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
291 
292 #ifdef CONFIG_MEMORY_HOTREMOVE
293 
294 extern void try_offline_node(int nid);
295 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
296 			 struct memory_group *group);
297 extern int remove_memory(u64 start, u64 size);
298 extern void __remove_memory(u64 start, u64 size);
299 extern int offline_and_remove_memory(u64 start, u64 size);
300 
301 #else
302 static inline void try_offline_node(int nid) {}
303 
304 static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
305 				struct memory_group *group)
306 {
307 	return -EINVAL;
308 }
309 
310 static inline int remove_memory(u64 start, u64 size)
311 {
312 	return -EBUSY;
313 }
314 
315 static inline void __remove_memory(u64 start, u64 size) {}
316 #endif /* CONFIG_MEMORY_HOTREMOVE */
317 
318 extern void set_zone_contiguous(struct zone *zone);
319 extern void clear_zone_contiguous(struct zone *zone);
320 
321 #ifdef CONFIG_MEMORY_HOTPLUG
322 extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
323 extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
324 extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
325 extern int add_memory_resource(int nid, struct resource *resource,
326 			       mhp_t mhp_flags);
327 extern int add_memory_driver_managed(int nid, u64 start, u64 size,
328 				     const char *resource_name,
329 				     mhp_t mhp_flags);
330 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
331 				   unsigned long nr_pages,
332 				   struct vmem_altmap *altmap, int migratetype);
333 extern void remove_pfn_range_from_zone(struct zone *zone,
334 				       unsigned long start_pfn,
335 				       unsigned long nr_pages);
336 extern bool is_memblock_offlined(struct memory_block *mem);
337 extern int sparse_add_section(int nid, unsigned long pfn,
338 		unsigned long nr_pages, struct vmem_altmap *altmap);
339 extern void sparse_remove_section(struct mem_section *ms,
340 		unsigned long pfn, unsigned long nr_pages,
341 		unsigned long map_offset, struct vmem_altmap *altmap);
342 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
343 					  unsigned long pnum);
344 extern struct zone *zone_for_pfn_range(int online_type, int nid,
345 		struct memory_group *group, unsigned long start_pfn,
346 		unsigned long nr_pages);
347 extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
348 				      struct mhp_params *params);
349 void arch_remove_linear_mapping(u64 start, u64 size);
350 extern bool mhp_supports_memmap_on_memory(unsigned long size);
351 #endif /* CONFIG_MEMORY_HOTPLUG */
352 
353 #endif /* __LINUX_MEMORY_HOTPLUG_H */
354