xref: /linux-6.15/include/linux/memory_hotplug.h (revision df616d7a)
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 resource;
16 struct vmem_altmap;
17 
18 #ifdef CONFIG_MEMORY_HOTPLUG
19 /*
20  * Return page for the valid pfn only if the page is online. All pfn
21  * walkers which rely on the fully initialized page->flags and others
22  * should use this rather than pfn_valid && pfn_to_page
23  */
24 #define pfn_to_online_page(pfn)					   \
25 ({								   \
26 	struct page *___page = NULL;				   \
27 	unsigned long ___pfn = pfn;				   \
28 	unsigned long ___nr = pfn_to_section_nr(___pfn);	   \
29 								   \
30 	if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr) && \
31 	    pfn_valid_within(___pfn))				   \
32 		___page = pfn_to_page(___pfn);			   \
33 	___page;						   \
34 })
35 
36 /*
37  * Types for free bootmem stored in page->lru.next. These have to be in
38  * some random range in unsigned long space for debugging purposes.
39  */
40 enum {
41 	MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12,
42 	SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
43 	MIX_SECTION_INFO,
44 	NODE_INFO,
45 	MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
46 };
47 
48 /* Types for control the zone type of onlined and offlined memory */
49 enum {
50 	MMOP_OFFLINE = -1,
51 	MMOP_ONLINE_KEEP,
52 	MMOP_ONLINE_KERNEL,
53 	MMOP_ONLINE_MOVABLE,
54 };
55 
56 /*
57  * Restrictions for the memory hotplug:
58  * flags:  MHP_ flags
59  * altmap: alternative allocator for memmap array
60  */
61 struct mhp_restrictions {
62 	unsigned long flags;
63 	struct vmem_altmap *altmap;
64 };
65 
66 /*
67  * Zone resizing functions
68  *
69  * Note: any attempt to resize a zone should has pgdat_resize_lock()
70  * zone_span_writelock() both held. This ensure the size of a zone
71  * can't be changed while pgdat_resize_lock() held.
72  */
73 static inline unsigned zone_span_seqbegin(struct zone *zone)
74 {
75 	return read_seqbegin(&zone->span_seqlock);
76 }
77 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
78 {
79 	return read_seqretry(&zone->span_seqlock, iv);
80 }
81 static inline void zone_span_writelock(struct zone *zone)
82 {
83 	write_seqlock(&zone->span_seqlock);
84 }
85 static inline void zone_span_writeunlock(struct zone *zone)
86 {
87 	write_sequnlock(&zone->span_seqlock);
88 }
89 static inline void zone_seqlock_init(struct zone *zone)
90 {
91 	seqlock_init(&zone->span_seqlock);
92 }
93 extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
94 extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
95 extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
96 /* VM interface that may be used by firmware interface */
97 extern int online_pages(unsigned long, unsigned long, int);
98 extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
99 	unsigned long *valid_start, unsigned long *valid_end);
100 extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
101 						unsigned long end_pfn);
102 
103 typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
104 
105 extern int set_online_page_callback(online_page_callback_t callback);
106 extern int restore_online_page_callback(online_page_callback_t callback);
107 
108 extern void __online_page_set_limits(struct page *page);
109 extern void __online_page_increment_counters(struct page *page);
110 extern void __online_page_free(struct page *page);
111 
112 extern int try_online_node(int nid);
113 
114 extern int arch_add_memory(int nid, u64 start, u64 size,
115 			struct mhp_restrictions *restrictions);
116 extern u64 max_mem_size;
117 
118 extern bool memhp_auto_online;
119 /* If movable_node boot option specified */
120 extern bool movable_node_enabled;
121 static inline bool movable_node_is_enabled(void)
122 {
123 	return movable_node_enabled;
124 }
125 
126 #ifdef CONFIG_MEMORY_HOTREMOVE
127 extern void arch_remove_memory(int nid, u64 start, u64 size,
128 			       struct vmem_altmap *altmap);
129 extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
130 			   unsigned long nr_pages, struct vmem_altmap *altmap);
131 #endif /* CONFIG_MEMORY_HOTREMOVE */
132 
133 /*
134  * Do we want sysfs memblock files created. This will allow userspace to online
135  * and offline memory explicitly. Lack of this bit means that the caller has to
136  * call move_pfn_range_to_zone to finish the initialization.
137  */
138 
139 #define MHP_MEMBLOCK_API               (1<<0)
140 
141 /* reasonably generic interface to expand the physical pages */
142 extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
143 		       struct mhp_restrictions *restrictions);
144 
145 #ifndef CONFIG_ARCH_HAS_ADD_PAGES
146 static inline int add_pages(int nid, unsigned long start_pfn,
147 		unsigned long nr_pages, struct mhp_restrictions *restrictions)
148 {
149 	return __add_pages(nid, start_pfn, nr_pages, restrictions);
150 }
151 #else /* ARCH_HAS_ADD_PAGES */
152 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
153 	      struct mhp_restrictions *restrictions);
154 #endif /* ARCH_HAS_ADD_PAGES */
155 
156 #ifdef CONFIG_NUMA
157 extern int memory_add_physaddr_to_nid(u64 start);
158 #else
159 static inline int memory_add_physaddr_to_nid(u64 start)
160 {
161 	return 0;
162 }
163 #endif
164 
165 #ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
166 /*
167  * For supporting node-hotadd, we have to allocate a new pgdat.
168  *
169  * If an arch has generic style NODE_DATA(),
170  * node_data[nid] = kzalloc() works well. But it depends on the architecture.
171  *
172  * In general, generic_alloc_nodedata() is used.
173  * Now, arch_free_nodedata() is just defined for error path of node_hot_add.
174  *
175  */
176 extern pg_data_t *arch_alloc_nodedata(int nid);
177 extern void arch_free_nodedata(pg_data_t *pgdat);
178 extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
179 
180 #else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
181 
182 #define arch_alloc_nodedata(nid)	generic_alloc_nodedata(nid)
183 #define arch_free_nodedata(pgdat)	generic_free_nodedata(pgdat)
184 
185 #ifdef CONFIG_NUMA
186 /*
187  * If ARCH_HAS_NODEDATA_EXTENSION=n, this func is used to allocate pgdat.
188  * XXX: kmalloc_node() can't work well to get new node's memory at this time.
189  *	Because, pgdat for the new node is not allocated/initialized yet itself.
190  *	To use new node's memory, more consideration will be necessary.
191  */
192 #define generic_alloc_nodedata(nid)				\
193 ({								\
194 	kzalloc(sizeof(pg_data_t), GFP_KERNEL);			\
195 })
196 /*
197  * This definition is just for error path in node hotadd.
198  * For node hotremove, we have to replace this.
199  */
200 #define generic_free_nodedata(pgdat)	kfree(pgdat)
201 
202 extern pg_data_t *node_data[];
203 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
204 {
205 	node_data[nid] = pgdat;
206 }
207 
208 #else /* !CONFIG_NUMA */
209 
210 /* never called */
211 static inline pg_data_t *generic_alloc_nodedata(int nid)
212 {
213 	BUG();
214 	return NULL;
215 }
216 static inline void generic_free_nodedata(pg_data_t *pgdat)
217 {
218 }
219 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
220 {
221 }
222 #endif /* CONFIG_NUMA */
223 #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
224 
225 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
226 extern void __init register_page_bootmem_info_node(struct pglist_data *pgdat);
227 #else
228 static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
229 {
230 }
231 #endif
232 extern void put_page_bootmem(struct page *page);
233 extern void get_page_bootmem(unsigned long ingo, struct page *page,
234 			     unsigned long type);
235 
236 void get_online_mems(void);
237 void put_online_mems(void);
238 
239 void mem_hotplug_begin(void);
240 void mem_hotplug_done(void);
241 
242 extern void set_zone_contiguous(struct zone *zone);
243 extern void clear_zone_contiguous(struct zone *zone);
244 
245 #else /* ! CONFIG_MEMORY_HOTPLUG */
246 #define pfn_to_online_page(pfn)			\
247 ({						\
248 	struct page *___page = NULL;		\
249 	if (pfn_valid(pfn))			\
250 		___page = pfn_to_page(pfn);	\
251 	___page;				\
252  })
253 
254 static inline unsigned zone_span_seqbegin(struct zone *zone)
255 {
256 	return 0;
257 }
258 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
259 {
260 	return 0;
261 }
262 static inline void zone_span_writelock(struct zone *zone) {}
263 static inline void zone_span_writeunlock(struct zone *zone) {}
264 static inline void zone_seqlock_init(struct zone *zone) {}
265 
266 static inline int mhp_notimplemented(const char *func)
267 {
268 	printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
269 	dump_stack();
270 	return -ENOSYS;
271 }
272 
273 static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
274 {
275 }
276 
277 static inline int try_online_node(int nid)
278 {
279 	return 0;
280 }
281 
282 static inline void get_online_mems(void) {}
283 static inline void put_online_mems(void) {}
284 
285 static inline void mem_hotplug_begin(void) {}
286 static inline void mem_hotplug_done(void) {}
287 
288 static inline bool movable_node_is_enabled(void)
289 {
290 	return false;
291 }
292 #endif /* ! CONFIG_MEMORY_HOTPLUG */
293 
294 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
295 /*
296  * pgdat resizing functions
297  */
298 static inline
299 void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
300 {
301 	spin_lock_irqsave(&pgdat->node_size_lock, *flags);
302 }
303 static inline
304 void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
305 {
306 	spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
307 }
308 static inline
309 void pgdat_resize_init(struct pglist_data *pgdat)
310 {
311 	spin_lock_init(&pgdat->node_size_lock);
312 }
313 #else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
314 /*
315  * Stub functions for when hotplug is off
316  */
317 static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
318 static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
319 static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
320 #endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
321 
322 #ifdef CONFIG_MEMORY_HOTREMOVE
323 
324 extern bool is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
325 extern void try_offline_node(int nid);
326 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
327 extern void remove_memory(int nid, u64 start, u64 size);
328 extern void __remove_memory(int nid, u64 start, u64 size);
329 
330 #else
331 static inline bool is_mem_section_removable(unsigned long pfn,
332 					unsigned long nr_pages)
333 {
334 	return false;
335 }
336 
337 static inline void try_offline_node(int nid) {}
338 
339 static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
340 {
341 	return -EINVAL;
342 }
343 
344 static inline void remove_memory(int nid, u64 start, u64 size) {}
345 static inline void __remove_memory(int nid, u64 start, u64 size) {}
346 #endif /* CONFIG_MEMORY_HOTREMOVE */
347 
348 extern void __ref free_area_init_core_hotplug(int nid);
349 extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
350 		void *arg, int (*func)(struct memory_block *, void *));
351 extern int __add_memory(int nid, u64 start, u64 size);
352 extern int add_memory(int nid, u64 start, u64 size);
353 extern int add_memory_resource(int nid, struct resource *resource);
354 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
355 		unsigned long nr_pages, struct vmem_altmap *altmap);
356 extern bool is_memblock_offlined(struct memory_block *mem);
357 extern int sparse_add_one_section(int nid, unsigned long start_pfn,
358 				  struct vmem_altmap *altmap);
359 extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
360 		unsigned long map_offset, struct vmem_altmap *altmap);
361 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
362 					  unsigned long pnum);
363 extern bool allow_online_pfn_range(int nid, unsigned long pfn, unsigned long nr_pages,
364 		int online_type);
365 extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
366 		unsigned long nr_pages);
367 #endif /* __LINUX_MEMORY_HOTPLUG_H */
368