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 * The hotplugged memory is completely inaccessible while the memory is
63 * offline. The memory provider will handle MEM_PREPARE_ONLINE /
64 * MEM_FINISH_OFFLINE notifications and make the memory accessible.
65 *
66 * This flag is only relevant when used along with MHP_MEMMAP_ON_MEMORY,
67 * because the altmap cannot be written (e.g., poisoned) when adding
68 * memory -- before it is set online.
69 *
70 * This allows for adding memory with an altmap that is not currently
71 * made available by a hypervisor. When onlining that memory, the
72 * hypervisor can be instructed to make that memory available, and
73 * the onlining phase will not require any memory allocations, which is
74 * helpful in low-memory situations.
75 */
76#define MHP_OFFLINE_INACCESSIBLE ((__force mhp_t)BIT(3))
77
78/*
79 * Extended parameters for memory hotplug:
80 * altmap: alternative allocator for memmap array (optional)
81 * pgprot: page protection flags to apply to newly created page tables
82 * (required)
83 */
84struct mhp_params {
85 struct vmem_altmap *altmap;
86 pgprot_t pgprot;
87 struct dev_pagemap *pgmap;
88};
89
90bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
91struct range mhp_get_pluggable_range(bool need_mapping);
92bool mhp_supports_memmap_on_memory(void);
93
94/*
95 * Zone resizing functions
96 *
97 * Note: any attempt to resize a zone should has pgdat_resize_lock()
98 * zone_span_writelock() both held. This ensure the size of a zone
99 * can't be changed while pgdat_resize_lock() held.
100 */
101static inline unsigned zone_span_seqbegin(struct zone *zone)
102{
103 return read_seqbegin(&zone->span_seqlock);
104}
105static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
106{
107 return read_seqretry(&zone->span_seqlock, iv);
108}
109static inline void zone_span_writelock(struct zone *zone)
110{
111 write_seqlock(&zone->span_seqlock);
112}
113static inline void zone_span_writeunlock(struct zone *zone)
114{
115 write_sequnlock(&zone->span_seqlock);
116}
117static inline void zone_seqlock_init(struct zone *zone)
118{
119 seqlock_init(&zone->span_seqlock);
120}
121extern void adjust_present_page_count(struct page *page,
122 struct memory_group *group,
123 long nr_pages);
124/* VM interface that may be used by firmware interface */
125extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
126 struct zone *zone, bool mhp_off_inaccessible);
127extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
128extern int online_pages(unsigned long pfn, unsigned long nr_pages,
129 struct zone *zone, struct memory_group *group);
130extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
131 unsigned long end_pfn);
132
133typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
134
135extern void generic_online_page(struct page *page, unsigned int order);
136extern int set_online_page_callback(online_page_callback_t callback);
137extern int restore_online_page_callback(online_page_callback_t callback);
138
139extern int try_online_node(int nid);
140
141extern int arch_add_memory(int nid, u64 start, u64 size,
142 struct mhp_params *params);
143extern u64 max_mem_size;
144
145extern int mhp_online_type_from_str(const char *str);
146
147/* If movable_node boot option specified */
148extern bool movable_node_enabled;
149static inline bool movable_node_is_enabled(void)
150{
151 return movable_node_enabled;
152}
153
154extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
155extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
156 struct vmem_altmap *altmap);
157
158/* reasonably generic interface to expand the physical pages */
159extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
160 struct mhp_params *params);
161
162#ifndef CONFIG_ARCH_HAS_ADD_PAGES
163static inline int add_pages(int nid, unsigned long start_pfn,
164 unsigned long nr_pages, struct mhp_params *params)
165{
166 return __add_pages(nid, start_pfn, nr_pages, params);
167}
168#else /* ARCH_HAS_ADD_PAGES */
169int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
170 struct mhp_params *params);
171#endif /* ARCH_HAS_ADD_PAGES */
172
173void get_online_mems(void);
174void put_online_mems(void);
175
176void mem_hotplug_begin(void);
177void mem_hotplug_done(void);
178
179/* See kswapd_is_running() */
180static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
181{
182 mutex_lock(&pgdat->kswapd_lock);
183}
184
185static inline void pgdat_kswapd_unlock(pg_data_t *pgdat)
186{
187 mutex_unlock(&pgdat->kswapd_lock);
188}
189
190static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat)
191{
192 mutex_init(&pgdat->kswapd_lock);
193}
194
195#else /* ! CONFIG_MEMORY_HOTPLUG */
196#define pfn_to_online_page(pfn) \
197({ \
198 struct page *___page = NULL; \
199 if (pfn_valid(pfn)) \
200 ___page = pfn_to_page(pfn); \
201 ___page; \
202 })
203
204static inline unsigned zone_span_seqbegin(struct zone *zone)
205{
206 return 0;
207}
208static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
209{
210 return 0;
211}
212static inline void zone_span_writelock(struct zone *zone) {}
213static inline void zone_span_writeunlock(struct zone *zone) {}
214static inline void zone_seqlock_init(struct zone *zone) {}
215
216static inline int try_online_node(int nid)
217{
218 return 0;
219}
220
221static inline void get_online_mems(void) {}
222static inline void put_online_mems(void) {}
223
224static inline void mem_hotplug_begin(void) {}
225static inline void mem_hotplug_done(void) {}
226
227static inline bool movable_node_is_enabled(void)
228{
229 return false;
230}
231
232static inline bool mhp_supports_memmap_on_memory(void)
233{
234 return false;
235}
236
237static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {}
238static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {}
239static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {}
240#endif /* ! CONFIG_MEMORY_HOTPLUG */
241
242/*
243 * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
244 * platforms might override and use arch_get_mappable_range()
245 * for internal non memory hotplug purposes.
246 */
247struct range arch_get_mappable_range(void);
248
249#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
250/*
251 * pgdat resizing functions
252 */
253static inline
254void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
255{
256 spin_lock_irqsave(&pgdat->node_size_lock, *flags);
257}
258static inline
259void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
260{
261 spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
262}
263static inline
264void pgdat_resize_init(struct pglist_data *pgdat)
265{
266 spin_lock_init(&pgdat->node_size_lock);
267}
268#else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
269/*
270 * Stub functions for when hotplug is off
271 */
272static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
273static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
274static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
275#endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
276
277#ifdef CONFIG_MEMORY_HOTREMOVE
278
279extern void try_offline_node(int nid);
280extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
281 struct zone *zone, struct memory_group *group);
282extern int remove_memory(u64 start, u64 size);
283extern void __remove_memory(u64 start, u64 size);
284extern int offline_and_remove_memory(u64 start, u64 size);
285
286#else
287static inline void try_offline_node(int nid) {}
288
289static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
290 struct zone *zone, struct memory_group *group)
291{
292 return -EINVAL;
293}
294
295static inline int remove_memory(u64 start, u64 size)
296{
297 return -EBUSY;
298}
299
300static inline void __remove_memory(u64 start, u64 size) {}
301#endif /* CONFIG_MEMORY_HOTREMOVE */
302
303#ifdef CONFIG_MEMORY_HOTPLUG
304/* Default online_type (MMOP_*) when new memory blocks are added. */
305extern int mhp_get_default_online_type(void);
306extern void mhp_set_default_online_type(int online_type);
307extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
308extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
309extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
310extern int add_memory_resource(int nid, struct resource *resource,
311 mhp_t mhp_flags);
312extern int add_memory_driver_managed(int nid, u64 start, u64 size,
313 const char *resource_name,
314 mhp_t mhp_flags);
315extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
316 unsigned long nr_pages,
317 struct vmem_altmap *altmap, int migratetype,
318 bool isolate_pageblock);
319extern void remove_pfn_range_from_zone(struct zone *zone,
320 unsigned long start_pfn,
321 unsigned long nr_pages);
322extern int sparse_add_section(int nid, unsigned long pfn,
323 unsigned long nr_pages, struct vmem_altmap *altmap,
324 struct dev_pagemap *pgmap);
325extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
326 struct vmem_altmap *altmap);
327extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
328 unsigned long pnum);
329extern struct zone *zone_for_pfn_range(int online_type, int nid,
330 struct memory_group *group, unsigned long start_pfn,
331 unsigned long nr_pages);
332extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
333 struct mhp_params *params);
334void arch_remove_linear_mapping(u64 start, u64 size);
335#endif /* CONFIG_MEMORY_HOTPLUG */
336
337#endif /* __LINUX_MEMORY_HOTPLUG_H */
338