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_block;
15struct memory_group;
16struct resource;
17struct vmem_altmap;
18struct dev_pagemap;
19
20#ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
21/*
22 * For supporting node-hotadd, we have to allocate a new pgdat.
23 *
24 * If an arch has generic style NODE_DATA(),
25 * node_data[nid] = kzalloc() works well. But it depends on the architecture.
26 *
27 * In general, generic_alloc_nodedata() is used.
28 *
29 */
30extern pg_data_t *arch_alloc_nodedata(int nid);
31extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
32
33#else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
34
35#define arch_alloc_nodedata(nid) generic_alloc_nodedata(nid)
36
37#ifdef CONFIG_NUMA
38/*
39 * XXX: node aware allocation can't work well to get new node's memory at this time.
40 * Because, pgdat for the new node is not allocated/initialized yet itself.
41 * To use new node's memory, more consideration will be necessary.
42 */
43#define generic_alloc_nodedata(nid) \
44({ \
45 memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES); \
46})
47/*
48 * This definition is just for error path in node hotadd.
49 * For node hotremove, we have to replace this.
50 */
51#define generic_free_nodedata(pgdat) kfree(pgdat)
52
53extern pg_data_t *node_data[];
54static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
55{
56 node_data[nid] = pgdat;
57}
58
59#else /* !CONFIG_NUMA */
60
61/* never called */
62static inline pg_data_t *generic_alloc_nodedata(int nid)
63{
64 BUG();
65 return NULL;
66}
67static inline void generic_free_nodedata(pg_data_t *pgdat)
68{
69}
70static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
71{
72}
73#endif /* CONFIG_NUMA */
74#endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
75
76#ifdef CONFIG_MEMORY_HOTPLUG
77struct page *pfn_to_online_page(unsigned long pfn);
78
79/* Types for control the zone type of onlined and offlined memory */
80enum {
81 /* Offline the memory. */
82 MMOP_OFFLINE = 0,
83 /* Online the memory. Zone depends, see default_zone_for_pfn(). */
84 MMOP_ONLINE,
85 /* Online the memory to ZONE_NORMAL. */
86 MMOP_ONLINE_KERNEL,
87 /* Online the memory to ZONE_MOVABLE. */
88 MMOP_ONLINE_MOVABLE,
89};
90
91/* Flags for add_memory() and friends to specify memory hotplug details. */
92typedef int __bitwise mhp_t;
93
94/* No special request */
95#define MHP_NONE ((__force mhp_t)0)
96/*
97 * Allow merging of the added System RAM resource with adjacent,
98 * mergeable resources. After a successful call to add_memory_resource()
99 * with this flag set, the resource pointer must no longer be used as it
100 * might be stale, or the resource might have changed.
101 */
102#define MHP_MERGE_RESOURCE ((__force mhp_t)BIT(0))
103
104/*
105 * We want memmap (struct page array) to be self contained.
106 * To do so, we will use the beginning of the hot-added range to build
107 * the page tables for the memmap array that describes the entire range.
108 * Only selected architectures support it with SPARSE_VMEMMAP.
109 */
110#define MHP_MEMMAP_ON_MEMORY ((__force mhp_t)BIT(1))
111/*
112 * The nid field specifies a memory group id (mgid) instead. The memory group
113 * implies the node id (nid).
114 */
115#define MHP_NID_IS_MGID ((__force mhp_t)BIT(2))
116
117/*
118 * Extended parameters for memory hotplug:
119 * altmap: alternative allocator for memmap array (optional)
120 * pgprot: page protection flags to apply to newly created page tables
121 * (required)
122 */
123struct mhp_params {
124 struct vmem_altmap *altmap;
125 pgprot_t pgprot;
126 struct dev_pagemap *pgmap;
127};
128
129bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
130struct range mhp_get_pluggable_range(bool need_mapping);
131
132/*
133 * Zone resizing functions
134 *
135 * Note: any attempt to resize a zone should has pgdat_resize_lock()
136 * zone_span_writelock() both held. This ensure the size of a zone
137 * can't be changed while pgdat_resize_lock() held.
138 */
139static inline unsigned zone_span_seqbegin(struct zone *zone)
140{
141 return read_seqbegin(&zone->span_seqlock);
142}
143static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
144{
145 return read_seqretry(&zone->span_seqlock, iv);
146}
147static inline void zone_span_writelock(struct zone *zone)
148{
149 write_seqlock(&zone->span_seqlock);
150}
151static inline void zone_span_writeunlock(struct zone *zone)
152{
153 write_sequnlock(&zone->span_seqlock);
154}
155static inline void zone_seqlock_init(struct zone *zone)
156{
157 seqlock_init(&zone->span_seqlock);
158}
159extern void adjust_present_page_count(struct page *page,
160 struct memory_group *group,
161 long nr_pages);
162/* VM interface that may be used by firmware interface */
163extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
164 struct zone *zone);
165extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
166extern int online_pages(unsigned long pfn, unsigned long nr_pages,
167 struct zone *zone, struct memory_group *group);
168extern void __offline_isolated_pages(unsigned long start_pfn,
169 unsigned long end_pfn);
170
171typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
172
173extern void generic_online_page(struct page *page, unsigned int order);
174extern int set_online_page_callback(online_page_callback_t callback);
175extern int restore_online_page_callback(online_page_callback_t callback);
176
177extern int try_online_node(int nid);
178
179extern int arch_add_memory(int nid, u64 start, u64 size,
180 struct mhp_params *params);
181extern u64 max_mem_size;
182
183extern int mhp_online_type_from_str(const char *str);
184
185/* Default online_type (MMOP_*) when new memory blocks are added. */
186extern int mhp_default_online_type;
187/* If movable_node boot option specified */
188extern bool movable_node_enabled;
189static inline bool movable_node_is_enabled(void)
190{
191 return movable_node_enabled;
192}
193
194extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
195extern 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 */
199extern 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
203static 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 */
209int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
210 struct mhp_params *params);
211#endif /* ARCH_HAS_ADD_PAGES */
212
213void get_online_mems(void);
214void put_online_mems(void);
215
216void mem_hotplug_begin(void);
217void 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
228static inline unsigned zone_span_seqbegin(struct zone *zone)
229{
230 return 0;
231}
232static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
233{
234 return 0;
235}
236static inline void zone_span_writelock(struct zone *zone) {}
237static inline void zone_span_writeunlock(struct zone *zone) {}
238static inline void zone_seqlock_init(struct zone *zone) {}
239
240static inline int try_online_node(int nid)
241{
242 return 0;
243}
244
245static inline void get_online_mems(void) {}
246static inline void put_online_mems(void) {}
247
248static inline void mem_hotplug_begin(void) {}
249static inline void mem_hotplug_done(void) {}
250
251static 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 */
262struct 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 */
268static inline
269void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
270{
271 spin_lock_irqsave(&pgdat->node_size_lock, *flags);
272}
273static inline
274void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
275{
276 spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
277}
278static inline
279void 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 */
287static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
288static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
289static 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
294extern void try_offline_node(int nid);
295extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
296 struct zone *zone, struct memory_group *group);
297extern int remove_memory(u64 start, u64 size);
298extern void __remove_memory(u64 start, u64 size);
299extern int offline_and_remove_memory(u64 start, u64 size);
300
301#else
302static inline void try_offline_node(int nid) {}
303
304static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
305 struct zone *zone, struct memory_group *group)
306{
307 return -EINVAL;
308}
309
310static inline int remove_memory(u64 start, u64 size)
311{
312 return -EBUSY;
313}
314
315static inline void __remove_memory(u64 start, u64 size) {}
316#endif /* CONFIG_MEMORY_HOTREMOVE */
317
318extern void set_zone_contiguous(struct zone *zone);
319extern void clear_zone_contiguous(struct zone *zone);
320
321#ifdef CONFIG_MEMORY_HOTPLUG
322extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
323extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
324extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
325extern int add_memory_resource(int nid, struct resource *resource,
326 mhp_t mhp_flags);
327extern int add_memory_driver_managed(int nid, u64 start, u64 size,
328 const char *resource_name,
329 mhp_t mhp_flags);
330extern 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);
333extern void remove_pfn_range_from_zone(struct zone *zone,
334 unsigned long start_pfn,
335 unsigned long nr_pages);
336extern bool is_memblock_offlined(struct memory_block *mem);
337extern int sparse_add_section(int nid, unsigned long pfn,
338 unsigned long nr_pages, struct vmem_altmap *altmap,
339 struct dev_pagemap *pgmap);
340extern void sparse_remove_section(struct mem_section *ms,
341 unsigned long pfn, unsigned long nr_pages,
342 unsigned long map_offset, struct vmem_altmap *altmap);
343extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
344 unsigned long pnum);
345extern struct zone *zone_for_pfn_range(int online_type, int nid,
346 struct memory_group *group, unsigned long start_pfn,
347 unsigned long nr_pages);
348extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
349 struct mhp_params *params);
350void arch_remove_linear_mapping(u64 start, u64 size);
351extern bool mhp_supports_memmap_on_memory(unsigned long size);
352#endif /* CONFIG_MEMORY_HOTPLUG */
353
354#endif /* __LINUX_MEMORY_HOTPLUG_H */
355

source code of linux/include/linux/memory_hotplug.h