xref: /linux-6.15/include/linux/memory_hotplug.h (revision 43f5b308)
1 #ifndef __LINUX_MEMORY_HOTPLUG_H
2 #define __LINUX_MEMORY_HOTPLUG_H
3 
4 #include <linux/mmzone.h>
5 #include <linux/spinlock.h>
6 #include <linux/notifier.h>
7 
8 struct page;
9 struct zone;
10 struct pglist_data;
11 struct mem_section;
12 
13 #ifdef CONFIG_MEMORY_HOTPLUG
14 
15 /*
16  * Magic number for free bootmem.
17  * The normal smallest mapcount is -1. Here is smaller value than it.
18  */
19 #define SECTION_INFO		0xfffffffe
20 #define MIX_INFO		0xfffffffd
21 #define NODE_INFO		0xfffffffc
22 
23 /*
24  * pgdat resizing functions
25  */
26 static inline
27 void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
28 {
29 	spin_lock_irqsave(&pgdat->node_size_lock, *flags);
30 }
31 static inline
32 void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
33 {
34 	spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
35 }
36 static inline
37 void pgdat_resize_init(struct pglist_data *pgdat)
38 {
39 	spin_lock_init(&pgdat->node_size_lock);
40 }
41 /*
42  * Zone resizing functions
43  */
44 static inline unsigned zone_span_seqbegin(struct zone *zone)
45 {
46 	return read_seqbegin(&zone->span_seqlock);
47 }
48 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
49 {
50 	return read_seqretry(&zone->span_seqlock, iv);
51 }
52 static inline void zone_span_writelock(struct zone *zone)
53 {
54 	write_seqlock(&zone->span_seqlock);
55 }
56 static inline void zone_span_writeunlock(struct zone *zone)
57 {
58 	write_sequnlock(&zone->span_seqlock);
59 }
60 static inline void zone_seqlock_init(struct zone *zone)
61 {
62 	seqlock_init(&zone->span_seqlock);
63 }
64 extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
65 extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
66 extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
67 /* need some defines for these for archs that don't support it */
68 extern void online_page(struct page *page);
69 /* VM interface that may be used by firmware interface */
70 extern int online_pages(unsigned long, unsigned long);
71 extern void __offline_isolated_pages(unsigned long, unsigned long);
72 extern int offline_pages(unsigned long, unsigned long, unsigned long);
73 
74 /* reasonably generic interface to expand the physical pages in a zone  */
75 extern int __add_pages(struct zone *zone, unsigned long start_pfn,
76 	unsigned long nr_pages);
77 extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
78 	unsigned long nr_pages);
79 
80 /*
81  * Walk through all memory which is registered as resource.
82  * arg is (start_pfn, nr_pages, private_arg_pointer)
83  */
84 extern int walk_memory_resource(unsigned long start_pfn,
85 			unsigned long nr_pages, void *arg,
86 			int (*func)(unsigned long, unsigned long, void *));
87 
88 #ifdef CONFIG_NUMA
89 extern int memory_add_physaddr_to_nid(u64 start);
90 #else
91 static inline int memory_add_physaddr_to_nid(u64 start)
92 {
93 	return 0;
94 }
95 #endif
96 
97 #ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
98 /*
99  * For supporting node-hotadd, we have to allocate a new pgdat.
100  *
101  * If an arch has generic style NODE_DATA(),
102  * node_data[nid] = kzalloc() works well. But it depends on the architecture.
103  *
104  * In general, generic_alloc_nodedata() is used.
105  * Now, arch_free_nodedata() is just defined for error path of node_hot_add.
106  *
107  */
108 extern pg_data_t *arch_alloc_nodedata(int nid);
109 extern void arch_free_nodedata(pg_data_t *pgdat);
110 extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
111 
112 #else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
113 
114 #define arch_alloc_nodedata(nid)	generic_alloc_nodedata(nid)
115 #define arch_free_nodedata(pgdat)	generic_free_nodedata(pgdat)
116 
117 #ifdef CONFIG_NUMA
118 /*
119  * If ARCH_HAS_NODEDATA_EXTENSION=n, this func is used to allocate pgdat.
120  * XXX: kmalloc_node() can't work well to get new node's memory at this time.
121  *	Because, pgdat for the new node is not allocated/initialized yet itself.
122  *	To use new node's memory, more consideration will be necessary.
123  */
124 #define generic_alloc_nodedata(nid)				\
125 ({								\
126 	kzalloc(sizeof(pg_data_t), GFP_KERNEL);			\
127 })
128 /*
129  * This definition is just for error path in node hotadd.
130  * For node hotremove, we have to replace this.
131  */
132 #define generic_free_nodedata(pgdat)	kfree(pgdat)
133 
134 extern pg_data_t *node_data[];
135 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
136 {
137 	node_data[nid] = pgdat;
138 }
139 
140 #else /* !CONFIG_NUMA */
141 
142 /* never called */
143 static inline pg_data_t *generic_alloc_nodedata(int nid)
144 {
145 	BUG();
146 	return NULL;
147 }
148 static inline void generic_free_nodedata(pg_data_t *pgdat)
149 {
150 }
151 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
152 {
153 }
154 #endif /* CONFIG_NUMA */
155 #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
156 
157 #ifdef CONFIG_SPARSEMEM_VMEMMAP
158 static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
159 {
160 }
161 static inline void put_page_bootmem(struct page *page)
162 {
163 }
164 #else
165 extern void register_page_bootmem_info_node(struct pglist_data *pgdat);
166 extern void put_page_bootmem(struct page *page);
167 #endif
168 
169 #else /* ! CONFIG_MEMORY_HOTPLUG */
170 /*
171  * Stub functions for when hotplug is off
172  */
173 static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
174 static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
175 static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
176 
177 static inline unsigned zone_span_seqbegin(struct zone *zone)
178 {
179 	return 0;
180 }
181 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
182 {
183 	return 0;
184 }
185 static inline void zone_span_writelock(struct zone *zone) {}
186 static inline void zone_span_writeunlock(struct zone *zone) {}
187 static inline void zone_seqlock_init(struct zone *zone) {}
188 
189 static inline int mhp_notimplemented(const char *func)
190 {
191 	printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
192 	dump_stack();
193 	return -ENOSYS;
194 }
195 
196 static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
197 {
198 }
199 
200 #endif /* ! CONFIG_MEMORY_HOTPLUG */
201 
202 extern int add_memory(int nid, u64 start, u64 size);
203 extern int arch_add_memory(int nid, u64 start, u64 size);
204 extern int remove_memory(u64 start, u64 size);
205 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
206 								int nr_pages);
207 extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
208 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
209 					  unsigned long pnum);
210 
211 #endif /* __LINUX_MEMORY_HOTPLUG_H */
212