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1 | /* | |
2 | * linux/mm/memory_hotplug.c | |
3 | * | |
4 | * Copyright (C) | |
5 | */ | |
6 | ||
7 | #include <linux/stddef.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/sched/signal.h> | |
10 | #include <linux/swap.h> | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/pagemap.h> | |
13 | #include <linux/compiler.h> | |
14 | #include <linux/export.h> | |
15 | #include <linux/pagevec.h> | |
16 | #include <linux/writeback.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/sysctl.h> | |
19 | #include <linux/cpu.h> | |
20 | #include <linux/memory.h> | |
21 | #include <linux/memremap.h> | |
22 | #include <linux/memory_hotplug.h> | |
23 | #include <linux/highmem.h> | |
24 | #include <linux/vmalloc.h> | |
25 | #include <linux/ioport.h> | |
26 | #include <linux/delay.h> | |
27 | #include <linux/migrate.h> | |
28 | #include <linux/page-isolation.h> | |
29 | #include <linux/pfn.h> | |
30 | #include <linux/suspend.h> | |
31 | #include <linux/mm_inline.h> | |
32 | #include <linux/firmware-map.h> | |
33 | #include <linux/stop_machine.h> | |
34 | #include <linux/hugetlb.h> | |
35 | #include <linux/memblock.h> | |
36 | #include <linux/bootmem.h> | |
37 | #include <linux/compaction.h> | |
38 | ||
39 | #include <asm/tlbflush.h> | |
40 | ||
41 | #include "internal.h" | |
42 | ||
43 | /* | |
44 | * online_page_callback contains pointer to current page onlining function. | |
45 | * Initially it is generic_online_page(). If it is required it could be | |
46 | * changed by calling set_online_page_callback() for callback registration | |
47 | * and restore_online_page_callback() for generic callback restore. | |
48 | */ | |
49 | ||
50 | static void generic_online_page(struct page *page); | |
51 | ||
52 | static online_page_callback_t online_page_callback = generic_online_page; | |
53 | static DEFINE_MUTEX(online_page_callback_lock); | |
54 | ||
55 | DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); | |
56 | ||
57 | void get_online_mems(void) | |
58 | { | |
59 | percpu_down_read(&mem_hotplug_lock); | |
60 | } | |
61 | ||
62 | void put_online_mems(void) | |
63 | { | |
64 | percpu_up_read(&mem_hotplug_lock); | |
65 | } | |
66 | ||
67 | bool movable_node_enabled = false; | |
68 | ||
69 | #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE | |
70 | bool memhp_auto_online; | |
71 | #else | |
72 | bool memhp_auto_online = true; | |
73 | #endif | |
74 | EXPORT_SYMBOL_GPL(memhp_auto_online); | |
75 | ||
76 | static int __init setup_memhp_default_state(char *str) | |
77 | { | |
78 | if (!strcmp(str, "online")) | |
79 | memhp_auto_online = true; | |
80 | else if (!strcmp(str, "offline")) | |
81 | memhp_auto_online = false; | |
82 | ||
83 | return 1; | |
84 | } | |
85 | __setup("memhp_default_state=", setup_memhp_default_state); | |
86 | ||
87 | void mem_hotplug_begin(void) | |
88 | { | |
89 | cpus_read_lock(); | |
90 | percpu_down_write(&mem_hotplug_lock); | |
91 | } | |
92 | ||
93 | void mem_hotplug_done(void) | |
94 | { | |
95 | percpu_up_write(&mem_hotplug_lock); | |
96 | cpus_read_unlock(); | |
97 | } | |
98 | ||
99 | /* add this memory to iomem resource */ | |
100 | static struct resource *register_memory_resource(u64 start, u64 size) | |
101 | { | |
102 | struct resource *res, *conflict; | |
103 | res = kzalloc(sizeof(struct resource), GFP_KERNEL); | |
104 | if (!res) | |
105 | return ERR_PTR(-ENOMEM); | |
106 | ||
107 | res->name = "System RAM"; | |
108 | res->start = start; | |
109 | res->end = start + size - 1; | |
110 | res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; | |
111 | conflict = request_resource_conflict(&iomem_resource, res); | |
112 | if (conflict) { | |
113 | if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { | |
114 | pr_debug("Device unaddressable memory block " | |
115 | "memory hotplug at %#010llx !\n", | |
116 | (unsigned long long)start); | |
117 | } | |
118 | pr_debug("System RAM resource %pR cannot be added\n", res); | |
119 | kfree(res); | |
120 | return ERR_PTR(-EEXIST); | |
121 | } | |
122 | return res; | |
123 | } | |
124 | ||
125 | static void release_memory_resource(struct resource *res) | |
126 | { | |
127 | if (!res) | |
128 | return; | |
129 | release_resource(res); | |
130 | kfree(res); | |
131 | return; | |
132 | } | |
133 | ||
134 | #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE | |
135 | void get_page_bootmem(unsigned long info, struct page *page, | |
136 | unsigned long type) | |
137 | { | |
138 | page->freelist = (void *)type; | |
139 | SetPagePrivate(page); | |
140 | set_page_private(page, info); | |
141 | page_ref_inc(page); | |
142 | } | |
143 | ||
144 | void put_page_bootmem(struct page *page) | |
145 | { | |
146 | unsigned long type; | |
147 | ||
148 | type = (unsigned long) page->freelist; | |
149 | BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || | |
150 | type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); | |
151 | ||
152 | if (page_ref_dec_return(page) == 1) { | |
153 | page->freelist = NULL; | |
154 | ClearPagePrivate(page); | |
155 | set_page_private(page, 0); | |
156 | INIT_LIST_HEAD(&page->lru); | |
157 | free_reserved_page(page); | |
158 | } | |
159 | } | |
160 | ||
161 | #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE | |
162 | #ifndef CONFIG_SPARSEMEM_VMEMMAP | |
163 | static void register_page_bootmem_info_section(unsigned long start_pfn) | |
164 | { | |
165 | unsigned long *usemap, mapsize, section_nr, i; | |
166 | struct mem_section *ms; | |
167 | struct page *page, *memmap; | |
168 | ||
169 | section_nr = pfn_to_section_nr(start_pfn); | |
170 | ms = __nr_to_section(section_nr); | |
171 | ||
172 | /* Get section's memmap address */ | |
173 | memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); | |
174 | ||
175 | /* | |
176 | * Get page for the memmap's phys address | |
177 | * XXX: need more consideration for sparse_vmemmap... | |
178 | */ | |
179 | page = virt_to_page(memmap); | |
180 | mapsize = sizeof(struct page) * PAGES_PER_SECTION; | |
181 | mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; | |
182 | ||
183 | /* remember memmap's page */ | |
184 | for (i = 0; i < mapsize; i++, page++) | |
185 | get_page_bootmem(section_nr, page, SECTION_INFO); | |
186 | ||
187 | usemap = ms->pageblock_flags; | |
188 | page = virt_to_page(usemap); | |
189 | ||
190 | mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; | |
191 | ||
192 | for (i = 0; i < mapsize; i++, page++) | |
193 | get_page_bootmem(section_nr, page, MIX_SECTION_INFO); | |
194 | ||
195 | } | |
196 | #else /* CONFIG_SPARSEMEM_VMEMMAP */ | |
197 | static void register_page_bootmem_info_section(unsigned long start_pfn) | |
198 | { | |
199 | unsigned long *usemap, mapsize, section_nr, i; | |
200 | struct mem_section *ms; | |
201 | struct page *page, *memmap; | |
202 | ||
203 | section_nr = pfn_to_section_nr(start_pfn); | |
204 | ms = __nr_to_section(section_nr); | |
205 | ||
206 | memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); | |
207 | ||
208 | register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); | |
209 | ||
210 | usemap = ms->pageblock_flags; | |
211 | page = virt_to_page(usemap); | |
212 | ||
213 | mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; | |
214 | ||
215 | for (i = 0; i < mapsize; i++, page++) | |
216 | get_page_bootmem(section_nr, page, MIX_SECTION_INFO); | |
217 | } | |
218 | #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ | |
219 | ||
220 | void __init register_page_bootmem_info_node(struct pglist_data *pgdat) | |
221 | { | |
222 | unsigned long i, pfn, end_pfn, nr_pages; | |
223 | int node = pgdat->node_id; | |
224 | struct page *page; | |
225 | ||
226 | nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; | |
227 | page = virt_to_page(pgdat); | |
228 | ||
229 | for (i = 0; i < nr_pages; i++, page++) | |
230 | get_page_bootmem(node, page, NODE_INFO); | |
231 | ||
232 | pfn = pgdat->node_start_pfn; | |
233 | end_pfn = pgdat_end_pfn(pgdat); | |
234 | ||
235 | /* register section info */ | |
236 | for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { | |
237 | /* | |
238 | * Some platforms can assign the same pfn to multiple nodes - on | |
239 | * node0 as well as nodeN. To avoid registering a pfn against | |
240 | * multiple nodes we check that this pfn does not already | |
241 | * reside in some other nodes. | |
242 | */ | |
243 | if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) | |
244 | register_page_bootmem_info_section(pfn); | |
245 | } | |
246 | } | |
247 | #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ | |
248 | ||
249 | static int __meminit __add_section(int nid, unsigned long phys_start_pfn, | |
250 | struct vmem_altmap *altmap, bool want_memblock) | |
251 | { | |
252 | int ret; | |
253 | ||
254 | if (pfn_valid(phys_start_pfn)) | |
255 | return -EEXIST; | |
256 | ||
257 | ret = sparse_add_one_section(NODE_DATA(nid), phys_start_pfn, altmap); | |
258 | if (ret < 0) | |
259 | return ret; | |
260 | ||
261 | if (!want_memblock) | |
262 | return 0; | |
263 | ||
264 | return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); | |
265 | } | |
266 | ||
267 | /* | |
268 | * Reasonably generic function for adding memory. It is | |
269 | * expected that archs that support memory hotplug will | |
270 | * call this function after deciding the zone to which to | |
271 | * add the new pages. | |
272 | */ | |
273 | int __ref __add_pages(int nid, unsigned long phys_start_pfn, | |
274 | unsigned long nr_pages, struct vmem_altmap *altmap, | |
275 | bool want_memblock) | |
276 | { | |
277 | unsigned long i; | |
278 | int err = 0; | |
279 | int start_sec, end_sec; | |
280 | ||
281 | /* during initialize mem_map, align hot-added range to section */ | |
282 | start_sec = pfn_to_section_nr(phys_start_pfn); | |
283 | end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); | |
284 | ||
285 | if (altmap) { | |
286 | /* | |
287 | * Validate altmap is within bounds of the total request | |
288 | */ | |
289 | if (altmap->base_pfn != phys_start_pfn | |
290 | || vmem_altmap_offset(altmap) > nr_pages) { | |
291 | pr_warn_once("memory add fail, invalid altmap\n"); | |
292 | err = -EINVAL; | |
293 | goto out; | |
294 | } | |
295 | altmap->alloc = 0; | |
296 | } | |
297 | ||
298 | for (i = start_sec; i <= end_sec; i++) { | |
299 | err = __add_section(nid, section_nr_to_pfn(i), altmap, | |
300 | want_memblock); | |
301 | ||
302 | /* | |
303 | * EEXIST is finally dealt with by ioresource collision | |
304 | * check. see add_memory() => register_memory_resource() | |
305 | * Warning will be printed if there is collision. | |
306 | */ | |
307 | if (err && (err != -EEXIST)) | |
308 | break; | |
309 | err = 0; | |
310 | cond_resched(); | |
311 | } | |
312 | vmemmap_populate_print_last(); | |
313 | out: | |
314 | return err; | |
315 | } | |
316 | ||
317 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
318 | /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ | |
319 | static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, | |
320 | unsigned long start_pfn, | |
321 | unsigned long end_pfn) | |
322 | { | |
323 | struct mem_section *ms; | |
324 | ||
325 | for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { | |
326 | ms = __pfn_to_section(start_pfn); | |
327 | ||
328 | if (unlikely(!valid_section(ms))) | |
329 | continue; | |
330 | ||
331 | if (unlikely(pfn_to_nid(start_pfn) != nid)) | |
332 | continue; | |
333 | ||
334 | if (zone && zone != page_zone(pfn_to_page(start_pfn))) | |
335 | continue; | |
336 | ||
337 | return start_pfn; | |
338 | } | |
339 | ||
340 | return 0; | |
341 | } | |
342 | ||
343 | /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ | |
344 | static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, | |
345 | unsigned long start_pfn, | |
346 | unsigned long end_pfn) | |
347 | { | |
348 | struct mem_section *ms; | |
349 | unsigned long pfn; | |
350 | ||
351 | /* pfn is the end pfn of a memory section. */ | |
352 | pfn = end_pfn - 1; | |
353 | for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { | |
354 | ms = __pfn_to_section(pfn); | |
355 | ||
356 | if (unlikely(!valid_section(ms))) | |
357 | continue; | |
358 | ||
359 | if (unlikely(pfn_to_nid(pfn) != nid)) | |
360 | continue; | |
361 | ||
362 | if (zone && zone != page_zone(pfn_to_page(pfn))) | |
363 | continue; | |
364 | ||
365 | return pfn; | |
366 | } | |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
371 | static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, | |
372 | unsigned long end_pfn) | |
373 | { | |
374 | unsigned long zone_start_pfn = zone->zone_start_pfn; | |
375 | unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ | |
376 | unsigned long zone_end_pfn = z; | |
377 | unsigned long pfn; | |
378 | struct mem_section *ms; | |
379 | int nid = zone_to_nid(zone); | |
380 | ||
381 | zone_span_writelock(zone); | |
382 | if (zone_start_pfn == start_pfn) { | |
383 | /* | |
384 | * If the section is smallest section in the zone, it need | |
385 | * shrink zone->zone_start_pfn and zone->zone_spanned_pages. | |
386 | * In this case, we find second smallest valid mem_section | |
387 | * for shrinking zone. | |
388 | */ | |
389 | pfn = find_smallest_section_pfn(nid, zone, end_pfn, | |
390 | zone_end_pfn); | |
391 | if (pfn) { | |
392 | zone->zone_start_pfn = pfn; | |
393 | zone->spanned_pages = zone_end_pfn - pfn; | |
394 | } | |
395 | } else if (zone_end_pfn == end_pfn) { | |
396 | /* | |
397 | * If the section is biggest section in the zone, it need | |
398 | * shrink zone->spanned_pages. | |
399 | * In this case, we find second biggest valid mem_section for | |
400 | * shrinking zone. | |
401 | */ | |
402 | pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, | |
403 | start_pfn); | |
404 | if (pfn) | |
405 | zone->spanned_pages = pfn - zone_start_pfn + 1; | |
406 | } | |
407 | ||
408 | /* | |
409 | * The section is not biggest or smallest mem_section in the zone, it | |
410 | * only creates a hole in the zone. So in this case, we need not | |
411 | * change the zone. But perhaps, the zone has only hole data. Thus | |
412 | * it check the zone has only hole or not. | |
413 | */ | |
414 | pfn = zone_start_pfn; | |
415 | for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { | |
416 | ms = __pfn_to_section(pfn); | |
417 | ||
418 | if (unlikely(!valid_section(ms))) | |
419 | continue; | |
420 | ||
421 | if (page_zone(pfn_to_page(pfn)) != zone) | |
422 | continue; | |
423 | ||
424 | /* If the section is current section, it continues the loop */ | |
425 | if (start_pfn == pfn) | |
426 | continue; | |
427 | ||
428 | /* If we find valid section, we have nothing to do */ | |
429 | zone_span_writeunlock(zone); | |
430 | return; | |
431 | } | |
432 | ||
433 | /* The zone has no valid section */ | |
434 | zone->zone_start_pfn = 0; | |
435 | zone->spanned_pages = 0; | |
436 | zone_span_writeunlock(zone); | |
437 | } | |
438 | ||
439 | static void shrink_pgdat_span(struct pglist_data *pgdat, | |
440 | unsigned long start_pfn, unsigned long end_pfn) | |
441 | { | |
442 | unsigned long pgdat_start_pfn = pgdat->node_start_pfn; | |
443 | unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ | |
444 | unsigned long pgdat_end_pfn = p; | |
445 | unsigned long pfn; | |
446 | struct mem_section *ms; | |
447 | int nid = pgdat->node_id; | |
448 | ||
449 | if (pgdat_start_pfn == start_pfn) { | |
450 | /* | |
451 | * If the section is smallest section in the pgdat, it need | |
452 | * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. | |
453 | * In this case, we find second smallest valid mem_section | |
454 | * for shrinking zone. | |
455 | */ | |
456 | pfn = find_smallest_section_pfn(nid, NULL, end_pfn, | |
457 | pgdat_end_pfn); | |
458 | if (pfn) { | |
459 | pgdat->node_start_pfn = pfn; | |
460 | pgdat->node_spanned_pages = pgdat_end_pfn - pfn; | |
461 | } | |
462 | } else if (pgdat_end_pfn == end_pfn) { | |
463 | /* | |
464 | * If the section is biggest section in the pgdat, it need | |
465 | * shrink pgdat->node_spanned_pages. | |
466 | * In this case, we find second biggest valid mem_section for | |
467 | * shrinking zone. | |
468 | */ | |
469 | pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, | |
470 | start_pfn); | |
471 | if (pfn) | |
472 | pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; | |
473 | } | |
474 | ||
475 | /* | |
476 | * If the section is not biggest or smallest mem_section in the pgdat, | |
477 | * it only creates a hole in the pgdat. So in this case, we need not | |
478 | * change the pgdat. | |
479 | * But perhaps, the pgdat has only hole data. Thus it check the pgdat | |
480 | * has only hole or not. | |
481 | */ | |
482 | pfn = pgdat_start_pfn; | |
483 | for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { | |
484 | ms = __pfn_to_section(pfn); | |
485 | ||
486 | if (unlikely(!valid_section(ms))) | |
487 | continue; | |
488 | ||
489 | if (pfn_to_nid(pfn) != nid) | |
490 | continue; | |
491 | ||
492 | /* If the section is current section, it continues the loop */ | |
493 | if (start_pfn == pfn) | |
494 | continue; | |
495 | ||
496 | /* If we find valid section, we have nothing to do */ | |
497 | return; | |
498 | } | |
499 | ||
500 | /* The pgdat has no valid section */ | |
501 | pgdat->node_start_pfn = 0; | |
502 | pgdat->node_spanned_pages = 0; | |
503 | } | |
504 | ||
505 | static void __remove_zone(struct zone *zone, unsigned long start_pfn) | |
506 | { | |
507 | struct pglist_data *pgdat = zone->zone_pgdat; | |
508 | int nr_pages = PAGES_PER_SECTION; | |
509 | unsigned long flags; | |
510 | ||
511 | pgdat_resize_lock(zone->zone_pgdat, &flags); | |
512 | shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); | |
513 | shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); | |
514 | pgdat_resize_unlock(zone->zone_pgdat, &flags); | |
515 | } | |
516 | ||
517 | static int __remove_section(struct zone *zone, struct mem_section *ms, | |
518 | unsigned long map_offset, struct vmem_altmap *altmap) | |
519 | { | |
520 | unsigned long start_pfn; | |
521 | int scn_nr; | |
522 | int ret = -EINVAL; | |
523 | ||
524 | if (!valid_section(ms)) | |
525 | return ret; | |
526 | ||
527 | ret = unregister_memory_section(ms); | |
528 | if (ret) | |
529 | return ret; | |
530 | ||
531 | scn_nr = __section_nr(ms); | |
532 | start_pfn = section_nr_to_pfn((unsigned long)scn_nr); | |
533 | __remove_zone(zone, start_pfn); | |
534 | ||
535 | sparse_remove_one_section(zone, ms, map_offset, altmap); | |
536 | return 0; | |
537 | } | |
538 | ||
539 | /** | |
540 | * __remove_pages() - remove sections of pages from a zone | |
541 | * @zone: zone from which pages need to be removed | |
542 | * @phys_start_pfn: starting pageframe (must be aligned to start of a section) | |
543 | * @nr_pages: number of pages to remove (must be multiple of section size) | |
544 | * @altmap: alternative device page map or %NULL if default memmap is used | |
545 | * | |
546 | * Generic helper function to remove section mappings and sysfs entries | |
547 | * for the section of the memory we are removing. Caller needs to make | |
548 | * sure that pages are marked reserved and zones are adjust properly by | |
549 | * calling offline_pages(). | |
550 | */ | |
551 | int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, | |
552 | unsigned long nr_pages, struct vmem_altmap *altmap) | |
553 | { | |
554 | unsigned long i; | |
555 | unsigned long map_offset = 0; | |
556 | int sections_to_remove, ret = 0; | |
557 | ||
558 | /* In the ZONE_DEVICE case device driver owns the memory region */ | |
559 | if (is_dev_zone(zone)) { | |
560 | if (altmap) | |
561 | map_offset = vmem_altmap_offset(altmap); | |
562 | } else { | |
563 | resource_size_t start, size; | |
564 | ||
565 | start = phys_start_pfn << PAGE_SHIFT; | |
566 | size = nr_pages * PAGE_SIZE; | |
567 | ||
568 | ret = release_mem_region_adjustable(&iomem_resource, start, | |
569 | size); | |
570 | if (ret) { | |
571 | resource_size_t endres = start + size - 1; | |
572 | ||
573 | pr_warn("Unable to release resource <%pa-%pa> (%d)\n", | |
574 | &start, &endres, ret); | |
575 | } | |
576 | } | |
577 | ||
578 | clear_zone_contiguous(zone); | |
579 | ||
580 | /* | |
581 | * We can only remove entire sections | |
582 | */ | |
583 | BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); | |
584 | BUG_ON(nr_pages % PAGES_PER_SECTION); | |
585 | ||
586 | sections_to_remove = nr_pages / PAGES_PER_SECTION; | |
587 | for (i = 0; i < sections_to_remove; i++) { | |
588 | unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; | |
589 | ||
590 | ret = __remove_section(zone, __pfn_to_section(pfn), map_offset, | |
591 | altmap); | |
592 | map_offset = 0; | |
593 | if (ret) | |
594 | break; | |
595 | } | |
596 | ||
597 | set_zone_contiguous(zone); | |
598 | ||
599 | return ret; | |
600 | } | |
601 | #endif /* CONFIG_MEMORY_HOTREMOVE */ | |
602 | ||
603 | int set_online_page_callback(online_page_callback_t callback) | |
604 | { | |
605 | int rc = -EINVAL; | |
606 | ||
607 | get_online_mems(); | |
608 | mutex_lock(&online_page_callback_lock); | |
609 | ||
610 | if (online_page_callback == generic_online_page) { | |
611 | online_page_callback = callback; | |
612 | rc = 0; | |
613 | } | |
614 | ||
615 | mutex_unlock(&online_page_callback_lock); | |
616 | put_online_mems(); | |
617 | ||
618 | return rc; | |
619 | } | |
620 | EXPORT_SYMBOL_GPL(set_online_page_callback); | |
621 | ||
622 | int restore_online_page_callback(online_page_callback_t callback) | |
623 | { | |
624 | int rc = -EINVAL; | |
625 | ||
626 | get_online_mems(); | |
627 | mutex_lock(&online_page_callback_lock); | |
628 | ||
629 | if (online_page_callback == callback) { | |
630 | online_page_callback = generic_online_page; | |
631 | rc = 0; | |
632 | } | |
633 | ||
634 | mutex_unlock(&online_page_callback_lock); | |
635 | put_online_mems(); | |
636 | ||
637 | return rc; | |
638 | } | |
639 | EXPORT_SYMBOL_GPL(restore_online_page_callback); | |
640 | ||
641 | void __online_page_set_limits(struct page *page) | |
642 | { | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(__online_page_set_limits); | |
645 | ||
646 | void __online_page_increment_counters(struct page *page) | |
647 | { | |
648 | adjust_managed_page_count(page, 1); | |
649 | } | |
650 | EXPORT_SYMBOL_GPL(__online_page_increment_counters); | |
651 | ||
652 | void __online_page_free(struct page *page) | |
653 | { | |
654 | __free_reserved_page(page); | |
655 | } | |
656 | EXPORT_SYMBOL_GPL(__online_page_free); | |
657 | ||
658 | static void generic_online_page(struct page *page) | |
659 | { | |
660 | __online_page_set_limits(page); | |
661 | __online_page_increment_counters(page); | |
662 | __online_page_free(page); | |
663 | } | |
664 | ||
665 | static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, | |
666 | void *arg) | |
667 | { | |
668 | unsigned long i; | |
669 | unsigned long onlined_pages = *(unsigned long *)arg; | |
670 | struct page *page; | |
671 | ||
672 | if (PageReserved(pfn_to_page(start_pfn))) | |
673 | for (i = 0; i < nr_pages; i++) { | |
674 | page = pfn_to_page(start_pfn + i); | |
675 | (*online_page_callback)(page); | |
676 | onlined_pages++; | |
677 | } | |
678 | ||
679 | online_mem_sections(start_pfn, start_pfn + nr_pages); | |
680 | ||
681 | *(unsigned long *)arg = onlined_pages; | |
682 | return 0; | |
683 | } | |
684 | ||
685 | /* check which state of node_states will be changed when online memory */ | |
686 | static void node_states_check_changes_online(unsigned long nr_pages, | |
687 | struct zone *zone, struct memory_notify *arg) | |
688 | { | |
689 | int nid = zone_to_nid(zone); | |
690 | enum zone_type zone_last = ZONE_NORMAL; | |
691 | ||
692 | /* | |
693 | * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] | |
694 | * contains nodes which have zones of 0...ZONE_NORMAL, | |
695 | * set zone_last to ZONE_NORMAL. | |
696 | * | |
697 | * If we don't have HIGHMEM nor movable node, | |
698 | * node_states[N_NORMAL_MEMORY] contains nodes which have zones of | |
699 | * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. | |
700 | */ | |
701 | if (N_MEMORY == N_NORMAL_MEMORY) | |
702 | zone_last = ZONE_MOVABLE; | |
703 | ||
704 | /* | |
705 | * if the memory to be online is in a zone of 0...zone_last, and | |
706 | * the zones of 0...zone_last don't have memory before online, we will | |
707 | * need to set the node to node_states[N_NORMAL_MEMORY] after | |
708 | * the memory is online. | |
709 | */ | |
710 | if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY)) | |
711 | arg->status_change_nid_normal = nid; | |
712 | else | |
713 | arg->status_change_nid_normal = -1; | |
714 | ||
715 | #ifdef CONFIG_HIGHMEM | |
716 | /* | |
717 | * If we have movable node, node_states[N_HIGH_MEMORY] | |
718 | * contains nodes which have zones of 0...ZONE_HIGHMEM, | |
719 | * set zone_last to ZONE_HIGHMEM. | |
720 | * | |
721 | * If we don't have movable node, node_states[N_NORMAL_MEMORY] | |
722 | * contains nodes which have zones of 0...ZONE_MOVABLE, | |
723 | * set zone_last to ZONE_MOVABLE. | |
724 | */ | |
725 | zone_last = ZONE_HIGHMEM; | |
726 | if (N_MEMORY == N_HIGH_MEMORY) | |
727 | zone_last = ZONE_MOVABLE; | |
728 | ||
729 | if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY)) | |
730 | arg->status_change_nid_high = nid; | |
731 | else | |
732 | arg->status_change_nid_high = -1; | |
733 | #else | |
734 | arg->status_change_nid_high = arg->status_change_nid_normal; | |
735 | #endif | |
736 | ||
737 | /* | |
738 | * if the node don't have memory befor online, we will need to | |
739 | * set the node to node_states[N_MEMORY] after the memory | |
740 | * is online. | |
741 | */ | |
742 | if (!node_state(nid, N_MEMORY)) | |
743 | arg->status_change_nid = nid; | |
744 | else | |
745 | arg->status_change_nid = -1; | |
746 | } | |
747 | ||
748 | static void node_states_set_node(int node, struct memory_notify *arg) | |
749 | { | |
750 | if (arg->status_change_nid_normal >= 0) | |
751 | node_set_state(node, N_NORMAL_MEMORY); | |
752 | ||
753 | if (arg->status_change_nid_high >= 0) | |
754 | node_set_state(node, N_HIGH_MEMORY); | |
755 | ||
756 | node_set_state(node, N_MEMORY); | |
757 | } | |
758 | ||
759 | static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, | |
760 | unsigned long nr_pages) | |
761 | { | |
762 | unsigned long old_end_pfn = zone_end_pfn(zone); | |
763 | ||
764 | if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) | |
765 | zone->zone_start_pfn = start_pfn; | |
766 | ||
767 | zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; | |
768 | } | |
769 | ||
770 | static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, | |
771 | unsigned long nr_pages) | |
772 | { | |
773 | unsigned long old_end_pfn = pgdat_end_pfn(pgdat); | |
774 | ||
775 | if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) | |
776 | pgdat->node_start_pfn = start_pfn; | |
777 | ||
778 | pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; | |
779 | } | |
780 | ||
781 | void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, | |
782 | unsigned long nr_pages, struct vmem_altmap *altmap) | |
783 | { | |
784 | struct pglist_data *pgdat = zone->zone_pgdat; | |
785 | int nid = pgdat->node_id; | |
786 | unsigned long flags; | |
787 | ||
788 | if (zone_is_empty(zone)) | |
789 | init_currently_empty_zone(zone, start_pfn, nr_pages); | |
790 | ||
791 | clear_zone_contiguous(zone); | |
792 | ||
793 | /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ | |
794 | pgdat_resize_lock(pgdat, &flags); | |
795 | zone_span_writelock(zone); | |
796 | resize_zone_range(zone, start_pfn, nr_pages); | |
797 | zone_span_writeunlock(zone); | |
798 | resize_pgdat_range(pgdat, start_pfn, nr_pages); | |
799 | pgdat_resize_unlock(pgdat, &flags); | |
800 | ||
801 | /* | |
802 | * TODO now we have a visible range of pages which are not associated | |
803 | * with their zone properly. Not nice but set_pfnblock_flags_mask | |
804 | * expects the zone spans the pfn range. All the pages in the range | |
805 | * are reserved so nobody should be touching them so we should be safe | |
806 | */ | |
807 | memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, | |
808 | MEMMAP_HOTPLUG, altmap); | |
809 | ||
810 | set_zone_contiguous(zone); | |
811 | } | |
812 | ||
813 | /* | |
814 | * Returns a default kernel memory zone for the given pfn range. | |
815 | * If no kernel zone covers this pfn range it will automatically go | |
816 | * to the ZONE_NORMAL. | |
817 | */ | |
818 | static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, | |
819 | unsigned long nr_pages) | |
820 | { | |
821 | struct pglist_data *pgdat = NODE_DATA(nid); | |
822 | int zid; | |
823 | ||
824 | for (zid = 0; zid <= ZONE_NORMAL; zid++) { | |
825 | struct zone *zone = &pgdat->node_zones[zid]; | |
826 | ||
827 | if (zone_intersects(zone, start_pfn, nr_pages)) | |
828 | return zone; | |
829 | } | |
830 | ||
831 | return &pgdat->node_zones[ZONE_NORMAL]; | |
832 | } | |
833 | ||
834 | static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, | |
835 | unsigned long nr_pages) | |
836 | { | |
837 | struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, | |
838 | nr_pages); | |
839 | struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; | |
840 | bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); | |
841 | bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); | |
842 | ||
843 | /* | |
844 | * We inherit the existing zone in a simple case where zones do not | |
845 | * overlap in the given range | |
846 | */ | |
847 | if (in_kernel ^ in_movable) | |
848 | return (in_kernel) ? kernel_zone : movable_zone; | |
849 | ||
850 | /* | |
851 | * If the range doesn't belong to any zone or two zones overlap in the | |
852 | * given range then we use movable zone only if movable_node is | |
853 | * enabled because we always online to a kernel zone by default. | |
854 | */ | |
855 | return movable_node_enabled ? movable_zone : kernel_zone; | |
856 | } | |
857 | ||
858 | struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, | |
859 | unsigned long nr_pages) | |
860 | { | |
861 | if (online_type == MMOP_ONLINE_KERNEL) | |
862 | return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); | |
863 | ||
864 | if (online_type == MMOP_ONLINE_MOVABLE) | |
865 | return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; | |
866 | ||
867 | return default_zone_for_pfn(nid, start_pfn, nr_pages); | |
868 | } | |
869 | ||
870 | /* | |
871 | * Associates the given pfn range with the given node and the zone appropriate | |
872 | * for the given online type. | |
873 | */ | |
874 | static struct zone * __meminit move_pfn_range(int online_type, int nid, | |
875 | unsigned long start_pfn, unsigned long nr_pages) | |
876 | { | |
877 | struct zone *zone; | |
878 | ||
879 | zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages); | |
880 | move_pfn_range_to_zone(zone, start_pfn, nr_pages, NULL); | |
881 | return zone; | |
882 | } | |
883 | ||
884 | /* Must be protected by mem_hotplug_begin() or a device_lock */ | |
885 | int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) | |
886 | { | |
887 | unsigned long flags; | |
888 | unsigned long onlined_pages = 0; | |
889 | struct zone *zone; | |
890 | int need_zonelists_rebuild = 0; | |
891 | int nid; | |
892 | int ret; | |
893 | struct memory_notify arg; | |
894 | struct memory_block *mem; | |
895 | ||
896 | /* | |
897 | * We can't use pfn_to_nid() because nid might be stored in struct page | |
898 | * which is not yet initialized. Instead, we find nid from memory block. | |
899 | */ | |
900 | mem = find_memory_block(__pfn_to_section(pfn)); | |
901 | nid = mem->nid; | |
902 | ||
903 | /* associate pfn range with the zone */ | |
904 | zone = move_pfn_range(online_type, nid, pfn, nr_pages); | |
905 | ||
906 | arg.start_pfn = pfn; | |
907 | arg.nr_pages = nr_pages; | |
908 | node_states_check_changes_online(nr_pages, zone, &arg); | |
909 | ||
910 | ret = memory_notify(MEM_GOING_ONLINE, &arg); | |
911 | ret = notifier_to_errno(ret); | |
912 | if (ret) | |
913 | goto failed_addition; | |
914 | ||
915 | /* | |
916 | * If this zone is not populated, then it is not in zonelist. | |
917 | * This means the page allocator ignores this zone. | |
918 | * So, zonelist must be updated after online. | |
919 | */ | |
920 | if (!populated_zone(zone)) { | |
921 | need_zonelists_rebuild = 1; | |
922 | setup_zone_pageset(zone); | |
923 | } | |
924 | ||
925 | ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, | |
926 | online_pages_range); | |
927 | if (ret) { | |
928 | if (need_zonelists_rebuild) | |
929 | zone_pcp_reset(zone); | |
930 | goto failed_addition; | |
931 | } | |
932 | ||
933 | zone->present_pages += onlined_pages; | |
934 | ||
935 | pgdat_resize_lock(zone->zone_pgdat, &flags); | |
936 | zone->zone_pgdat->node_present_pages += onlined_pages; | |
937 | pgdat_resize_unlock(zone->zone_pgdat, &flags); | |
938 | ||
939 | if (onlined_pages) { | |
940 | node_states_set_node(nid, &arg); | |
941 | if (need_zonelists_rebuild) | |
942 | build_all_zonelists(NULL); | |
943 | else | |
944 | zone_pcp_update(zone); | |
945 | } | |
946 | ||
947 | init_per_zone_wmark_min(); | |
948 | ||
949 | if (onlined_pages) { | |
950 | kswapd_run(nid); | |
951 | kcompactd_run(nid); | |
952 | } | |
953 | ||
954 | vm_total_pages = nr_free_pagecache_pages(); | |
955 | ||
956 | writeback_set_ratelimit(); | |
957 | ||
958 | if (onlined_pages) | |
959 | memory_notify(MEM_ONLINE, &arg); | |
960 | return 0; | |
961 | ||
962 | failed_addition: | |
963 | pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", | |
964 | (unsigned long long) pfn << PAGE_SHIFT, | |
965 | (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); | |
966 | memory_notify(MEM_CANCEL_ONLINE, &arg); | |
967 | return ret; | |
968 | } | |
969 | #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ | |
970 | ||
971 | static void reset_node_present_pages(pg_data_t *pgdat) | |
972 | { | |
973 | struct zone *z; | |
974 | ||
975 | for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) | |
976 | z->present_pages = 0; | |
977 | ||
978 | pgdat->node_present_pages = 0; | |
979 | } | |
980 | ||
981 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ | |
982 | static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) | |
983 | { | |
984 | struct pglist_data *pgdat; | |
985 | unsigned long start_pfn = PFN_DOWN(start); | |
986 | ||
987 | pgdat = NODE_DATA(nid); | |
988 | if (!pgdat) { | |
989 | pgdat = arch_alloc_nodedata(nid); | |
990 | if (!pgdat) | |
991 | return NULL; | |
992 | ||
993 | arch_refresh_nodedata(nid, pgdat); | |
994 | } else { | |
995 | /* | |
996 | * Reset the nr_zones, order and classzone_idx before reuse. | |
997 | * Note that kswapd will init kswapd_classzone_idx properly | |
998 | * when it starts in the near future. | |
999 | */ | |
1000 | pgdat->nr_zones = 0; | |
1001 | pgdat->kswapd_order = 0; | |
1002 | pgdat->kswapd_classzone_idx = 0; | |
1003 | } | |
1004 | ||
1005 | /* we can use NODE_DATA(nid) from here */ | |
1006 | ||
1007 | pgdat->node_id = nid; | |
1008 | pgdat->node_start_pfn = start_pfn; | |
1009 | ||
1010 | /* init node's zones as empty zones, we don't have any present pages.*/ | |
1011 | free_area_init_core_hotplug(nid); | |
1012 | pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); | |
1013 | ||
1014 | /* | |
1015 | * The node we allocated has no zone fallback lists. For avoiding | |
1016 | * to access not-initialized zonelist, build here. | |
1017 | */ | |
1018 | build_all_zonelists(pgdat); | |
1019 | ||
1020 | /* | |
1021 | * When memory is hot-added, all the memory is in offline state. So | |
1022 | * clear all zones' present_pages because they will be updated in | |
1023 | * online_pages() and offline_pages(). | |
1024 | */ | |
1025 | reset_node_managed_pages(pgdat); | |
1026 | reset_node_present_pages(pgdat); | |
1027 | ||
1028 | return pgdat; | |
1029 | } | |
1030 | ||
1031 | static void rollback_node_hotadd(int nid) | |
1032 | { | |
1033 | pg_data_t *pgdat = NODE_DATA(nid); | |
1034 | ||
1035 | arch_refresh_nodedata(nid, NULL); | |
1036 | free_percpu(pgdat->per_cpu_nodestats); | |
1037 | arch_free_nodedata(pgdat); | |
1038 | return; | |
1039 | } | |
1040 | ||
1041 | ||
1042 | /** | |
1043 | * try_online_node - online a node if offlined | |
1044 | * @nid: the node ID | |
1045 | * @start: start addr of the node | |
1046 | * @set_node_online: Whether we want to online the node | |
1047 | * called by cpu_up() to online a node without onlined memory. | |
1048 | * | |
1049 | * Returns: | |
1050 | * 1 -> a new node has been allocated | |
1051 | * 0 -> the node is already online | |
1052 | * -ENOMEM -> the node could not be allocated | |
1053 | */ | |
1054 | static int __try_online_node(int nid, u64 start, bool set_node_online) | |
1055 | { | |
1056 | pg_data_t *pgdat; | |
1057 | int ret = 1; | |
1058 | ||
1059 | if (node_online(nid)) | |
1060 | return 0; | |
1061 | ||
1062 | pgdat = hotadd_new_pgdat(nid, start); | |
1063 | if (!pgdat) { | |
1064 | pr_err("Cannot online node %d due to NULL pgdat\n", nid); | |
1065 | ret = -ENOMEM; | |
1066 | goto out; | |
1067 | } | |
1068 | ||
1069 | if (set_node_online) { | |
1070 | node_set_online(nid); | |
1071 | ret = register_one_node(nid); | |
1072 | BUG_ON(ret); | |
1073 | } | |
1074 | out: | |
1075 | return ret; | |
1076 | } | |
1077 | ||
1078 | /* | |
1079 | * Users of this function always want to online/register the node | |
1080 | */ | |
1081 | int try_online_node(int nid) | |
1082 | { | |
1083 | int ret; | |
1084 | ||
1085 | mem_hotplug_begin(); | |
1086 | ret = __try_online_node(nid, 0, true); | |
1087 | mem_hotplug_done(); | |
1088 | return ret; | |
1089 | } | |
1090 | ||
1091 | static int check_hotplug_memory_range(u64 start, u64 size) | |
1092 | { | |
1093 | unsigned long block_sz = memory_block_size_bytes(); | |
1094 | u64 block_nr_pages = block_sz >> PAGE_SHIFT; | |
1095 | u64 nr_pages = size >> PAGE_SHIFT; | |
1096 | u64 start_pfn = PFN_DOWN(start); | |
1097 | ||
1098 | /* memory range must be block size aligned */ | |
1099 | if (!nr_pages || !IS_ALIGNED(start_pfn, block_nr_pages) || | |
1100 | !IS_ALIGNED(nr_pages, block_nr_pages)) { | |
1101 | pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", | |
1102 | block_sz, start, size); | |
1103 | return -EINVAL; | |
1104 | } | |
1105 | ||
1106 | return 0; | |
1107 | } | |
1108 | ||
1109 | static int online_memory_block(struct memory_block *mem, void *arg) | |
1110 | { | |
1111 | return device_online(&mem->dev); | |
1112 | } | |
1113 | ||
1114 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ | |
1115 | int __ref add_memory_resource(int nid, struct resource *res, bool online) | |
1116 | { | |
1117 | u64 start, size; | |
1118 | bool new_node = false; | |
1119 | int ret; | |
1120 | ||
1121 | start = res->start; | |
1122 | size = resource_size(res); | |
1123 | ||
1124 | ret = check_hotplug_memory_range(start, size); | |
1125 | if (ret) | |
1126 | return ret; | |
1127 | ||
1128 | mem_hotplug_begin(); | |
1129 | ||
1130 | /* | |
1131 | * Add new range to memblock so that when hotadd_new_pgdat() is called | |
1132 | * to allocate new pgdat, get_pfn_range_for_nid() will be able to find | |
1133 | * this new range and calculate total pages correctly. The range will | |
1134 | * be removed at hot-remove time. | |
1135 | */ | |
1136 | memblock_add_node(start, size, nid); | |
1137 | ||
1138 | ret = __try_online_node(nid, start, false); | |
1139 | if (ret < 0) | |
1140 | goto error; | |
1141 | new_node = ret; | |
1142 | ||
1143 | /* call arch's memory hotadd */ | |
1144 | ret = arch_add_memory(nid, start, size, NULL, true); | |
1145 | if (ret < 0) | |
1146 | goto error; | |
1147 | ||
1148 | if (new_node) { | |
1149 | /* If sysfs file of new node can't be created, cpu on the node | |
1150 | * can't be hot-added. There is no rollback way now. | |
1151 | * So, check by BUG_ON() to catch it reluctantly.. | |
1152 | * We online node here. We can't roll back from here. | |
1153 | */ | |
1154 | node_set_online(nid); | |
1155 | ret = __register_one_node(nid); | |
1156 | BUG_ON(ret); | |
1157 | } | |
1158 | ||
1159 | /* link memory sections under this node.*/ | |
1160 | ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); | |
1161 | BUG_ON(ret); | |
1162 | ||
1163 | /* create new memmap entry */ | |
1164 | firmware_map_add_hotplug(start, start + size, "System RAM"); | |
1165 | ||
1166 | /* online pages if requested */ | |
1167 | if (online) | |
1168 | walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), | |
1169 | NULL, online_memory_block); | |
1170 | ||
1171 | goto out; | |
1172 | ||
1173 | error: | |
1174 | /* rollback pgdat allocation and others */ | |
1175 | if (new_node) | |
1176 | rollback_node_hotadd(nid); | |
1177 | memblock_remove(start, size); | |
1178 | ||
1179 | out: | |
1180 | mem_hotplug_done(); | |
1181 | return ret; | |
1182 | } | |
1183 | EXPORT_SYMBOL_GPL(add_memory_resource); | |
1184 | ||
1185 | int __ref add_memory(int nid, u64 start, u64 size) | |
1186 | { | |
1187 | struct resource *res; | |
1188 | int ret; | |
1189 | ||
1190 | res = register_memory_resource(start, size); | |
1191 | if (IS_ERR(res)) | |
1192 | return PTR_ERR(res); | |
1193 | ||
1194 | ret = add_memory_resource(nid, res, memhp_auto_online); | |
1195 | if (ret < 0) | |
1196 | release_memory_resource(res); | |
1197 | return ret; | |
1198 | } | |
1199 | EXPORT_SYMBOL_GPL(add_memory); | |
1200 | ||
1201 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
1202 | /* | |
1203 | * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy | |
1204 | * set and the size of the free page is given by page_order(). Using this, | |
1205 | * the function determines if the pageblock contains only free pages. | |
1206 | * Due to buddy contraints, a free page at least the size of a pageblock will | |
1207 | * be located at the start of the pageblock | |
1208 | */ | |
1209 | static inline int pageblock_free(struct page *page) | |
1210 | { | |
1211 | return PageBuddy(page) && page_order(page) >= pageblock_order; | |
1212 | } | |
1213 | ||
1214 | /* Return the start of the next active pageblock after a given page */ | |
1215 | static struct page *next_active_pageblock(struct page *page) | |
1216 | { | |
1217 | /* Ensure the starting page is pageblock-aligned */ | |
1218 | BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1)); | |
1219 | ||
1220 | /* If the entire pageblock is free, move to the end of free page */ | |
1221 | if (pageblock_free(page)) { | |
1222 | int order; | |
1223 | /* be careful. we don't have locks, page_order can be changed.*/ | |
1224 | order = page_order(page); | |
1225 | if ((order < MAX_ORDER) && (order >= pageblock_order)) | |
1226 | return page + (1 << order); | |
1227 | } | |
1228 | ||
1229 | return page + pageblock_nr_pages; | |
1230 | } | |
1231 | ||
1232 | static bool is_pageblock_removable_nolock(struct page *page) | |
1233 | { | |
1234 | struct zone *zone; | |
1235 | unsigned long pfn; | |
1236 | ||
1237 | /* | |
1238 | * We have to be careful here because we are iterating over memory | |
1239 | * sections which are not zone aware so we might end up outside of | |
1240 | * the zone but still within the section. | |
1241 | * We have to take care about the node as well. If the node is offline | |
1242 | * its NODE_DATA will be NULL - see page_zone. | |
1243 | */ | |
1244 | if (!node_online(page_to_nid(page))) | |
1245 | return false; | |
1246 | ||
1247 | zone = page_zone(page); | |
1248 | pfn = page_to_pfn(page); | |
1249 | if (!zone_spans_pfn(zone, pfn)) | |
1250 | return false; | |
1251 | ||
1252 | return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, true); | |
1253 | } | |
1254 | ||
1255 | /* Checks if this range of memory is likely to be hot-removable. */ | |
1256 | bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) | |
1257 | { | |
1258 | struct page *page = pfn_to_page(start_pfn); | |
1259 | struct page *end_page = page + nr_pages; | |
1260 | ||
1261 | /* Check the starting page of each pageblock within the range */ | |
1262 | for (; page < end_page; page = next_active_pageblock(page)) { | |
1263 | if (!is_pageblock_removable_nolock(page)) | |
1264 | return false; | |
1265 | cond_resched(); | |
1266 | } | |
1267 | ||
1268 | /* All pageblocks in the memory block are likely to be hot-removable */ | |
1269 | return true; | |
1270 | } | |
1271 | ||
1272 | /* | |
1273 | * Confirm all pages in a range [start, end) belong to the same zone. | |
1274 | * When true, return its valid [start, end). | |
1275 | */ | |
1276 | int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, | |
1277 | unsigned long *valid_start, unsigned long *valid_end) | |
1278 | { | |
1279 | unsigned long pfn, sec_end_pfn; | |
1280 | unsigned long start, end; | |
1281 | struct zone *zone = NULL; | |
1282 | struct page *page; | |
1283 | int i; | |
1284 | for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); | |
1285 | pfn < end_pfn; | |
1286 | pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { | |
1287 | /* Make sure the memory section is present first */ | |
1288 | if (!present_section_nr(pfn_to_section_nr(pfn))) | |
1289 | continue; | |
1290 | for (; pfn < sec_end_pfn && pfn < end_pfn; | |
1291 | pfn += MAX_ORDER_NR_PAGES) { | |
1292 | i = 0; | |
1293 | /* This is just a CONFIG_HOLES_IN_ZONE check.*/ | |
1294 | while ((i < MAX_ORDER_NR_PAGES) && | |
1295 | !pfn_valid_within(pfn + i)) | |
1296 | i++; | |
1297 | if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) | |
1298 | continue; | |
1299 | page = pfn_to_page(pfn + i); | |
1300 | if (zone && page_zone(page) != zone) | |
1301 | return 0; | |
1302 | if (!zone) | |
1303 | start = pfn + i; | |
1304 | zone = page_zone(page); | |
1305 | end = pfn + MAX_ORDER_NR_PAGES; | |
1306 | } | |
1307 | } | |
1308 | ||
1309 | if (zone) { | |
1310 | *valid_start = start; | |
1311 | *valid_end = min(end, end_pfn); | |
1312 | return 1; | |
1313 | } else { | |
1314 | return 0; | |
1315 | } | |
1316 | } | |
1317 | ||
1318 | /* | |
1319 | * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, | |
1320 | * non-lru movable pages and hugepages). We scan pfn because it's much | |
1321 | * easier than scanning over linked list. This function returns the pfn | |
1322 | * of the first found movable page if it's found, otherwise 0. | |
1323 | */ | |
1324 | static unsigned long scan_movable_pages(unsigned long start, unsigned long end) | |
1325 | { | |
1326 | unsigned long pfn; | |
1327 | struct page *page; | |
1328 | for (pfn = start; pfn < end; pfn++) { | |
1329 | if (pfn_valid(pfn)) { | |
1330 | page = pfn_to_page(pfn); | |
1331 | if (PageLRU(page)) | |
1332 | return pfn; | |
1333 | if (__PageMovable(page)) | |
1334 | return pfn; | |
1335 | if (PageHuge(page)) { | |
1336 | if (hugepage_migration_supported(page_hstate(page)) && | |
1337 | page_huge_active(page)) | |
1338 | return pfn; | |
1339 | else | |
1340 | pfn = round_up(pfn + 1, | |
1341 | 1 << compound_order(page)) - 1; | |
1342 | } | |
1343 | } | |
1344 | } | |
1345 | return 0; | |
1346 | } | |
1347 | ||
1348 | static struct page *new_node_page(struct page *page, unsigned long private) | |
1349 | { | |
1350 | int nid = page_to_nid(page); | |
1351 | nodemask_t nmask = node_states[N_MEMORY]; | |
1352 | ||
1353 | /* | |
1354 | * try to allocate from a different node but reuse this node if there | |
1355 | * are no other online nodes to be used (e.g. we are offlining a part | |
1356 | * of the only existing node) | |
1357 | */ | |
1358 | node_clear(nid, nmask); | |
1359 | if (nodes_empty(nmask)) | |
1360 | node_set(nid, nmask); | |
1361 | ||
1362 | return new_page_nodemask(page, nid, &nmask); | |
1363 | } | |
1364 | ||
1365 | #define NR_OFFLINE_AT_ONCE_PAGES (256) | |
1366 | static int | |
1367 | do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) | |
1368 | { | |
1369 | unsigned long pfn; | |
1370 | struct page *page; | |
1371 | int move_pages = NR_OFFLINE_AT_ONCE_PAGES; | |
1372 | int not_managed = 0; | |
1373 | int ret = 0; | |
1374 | LIST_HEAD(source); | |
1375 | ||
1376 | for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { | |
1377 | if (!pfn_valid(pfn)) | |
1378 | continue; | |
1379 | page = pfn_to_page(pfn); | |
1380 | ||
1381 | if (PageHuge(page)) { | |
1382 | struct page *head = compound_head(page); | |
1383 | pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; | |
1384 | if (compound_order(head) > PFN_SECTION_SHIFT) { | |
1385 | ret = -EBUSY; | |
1386 | break; | |
1387 | } | |
1388 | if (isolate_huge_page(page, &source)) | |
1389 | move_pages -= 1 << compound_order(head); | |
1390 | continue; | |
1391 | } else if (PageTransHuge(page)) | |
1392 | pfn = page_to_pfn(compound_head(page)) | |
1393 | + hpage_nr_pages(page) - 1; | |
1394 | ||
1395 | if (!get_page_unless_zero(page)) | |
1396 | continue; | |
1397 | /* | |
1398 | * We can skip free pages. And we can deal with pages on | |
1399 | * LRU and non-lru movable pages. | |
1400 | */ | |
1401 | if (PageLRU(page)) | |
1402 | ret = isolate_lru_page(page); | |
1403 | else | |
1404 | ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); | |
1405 | if (!ret) { /* Success */ | |
1406 | put_page(page); | |
1407 | list_add_tail(&page->lru, &source); | |
1408 | move_pages--; | |
1409 | if (!__PageMovable(page)) | |
1410 | inc_node_page_state(page, NR_ISOLATED_ANON + | |
1411 | page_is_file_cache(page)); | |
1412 | ||
1413 | } else { | |
1414 | #ifdef CONFIG_DEBUG_VM | |
1415 | pr_alert("failed to isolate pfn %lx\n", pfn); | |
1416 | dump_page(page, "isolation failed"); | |
1417 | #endif | |
1418 | put_page(page); | |
1419 | /* Because we don't have big zone->lock. we should | |
1420 | check this again here. */ | |
1421 | if (page_count(page)) { | |
1422 | not_managed++; | |
1423 | ret = -EBUSY; | |
1424 | break; | |
1425 | } | |
1426 | } | |
1427 | } | |
1428 | if (!list_empty(&source)) { | |
1429 | if (not_managed) { | |
1430 | putback_movable_pages(&source); | |
1431 | goto out; | |
1432 | } | |
1433 | ||
1434 | /* Allocate a new page from the nearest neighbor node */ | |
1435 | ret = migrate_pages(&source, new_node_page, NULL, 0, | |
1436 | MIGRATE_SYNC, MR_MEMORY_HOTPLUG); | |
1437 | if (ret) | |
1438 | putback_movable_pages(&source); | |
1439 | } | |
1440 | out: | |
1441 | return ret; | |
1442 | } | |
1443 | ||
1444 | /* | |
1445 | * remove from free_area[] and mark all as Reserved. | |
1446 | */ | |
1447 | static int | |
1448 | offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, | |
1449 | void *data) | |
1450 | { | |
1451 | __offline_isolated_pages(start, start + nr_pages); | |
1452 | return 0; | |
1453 | } | |
1454 | ||
1455 | static void | |
1456 | offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) | |
1457 | { | |
1458 | walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, | |
1459 | offline_isolated_pages_cb); | |
1460 | } | |
1461 | ||
1462 | /* | |
1463 | * Check all pages in range, recoreded as memory resource, are isolated. | |
1464 | */ | |
1465 | static int | |
1466 | check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, | |
1467 | void *data) | |
1468 | { | |
1469 | int ret; | |
1470 | long offlined = *(long *)data; | |
1471 | ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true); | |
1472 | offlined = nr_pages; | |
1473 | if (!ret) | |
1474 | *(long *)data += offlined; | |
1475 | return ret; | |
1476 | } | |
1477 | ||
1478 | static long | |
1479 | check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) | |
1480 | { | |
1481 | long offlined = 0; | |
1482 | int ret; | |
1483 | ||
1484 | ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, | |
1485 | check_pages_isolated_cb); | |
1486 | if (ret < 0) | |
1487 | offlined = (long)ret; | |
1488 | return offlined; | |
1489 | } | |
1490 | ||
1491 | static int __init cmdline_parse_movable_node(char *p) | |
1492 | { | |
1493 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
1494 | movable_node_enabled = true; | |
1495 | #else | |
1496 | pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n"); | |
1497 | #endif | |
1498 | return 0; | |
1499 | } | |
1500 | early_param("movable_node", cmdline_parse_movable_node); | |
1501 | ||
1502 | /* check which state of node_states will be changed when offline memory */ | |
1503 | static void node_states_check_changes_offline(unsigned long nr_pages, | |
1504 | struct zone *zone, struct memory_notify *arg) | |
1505 | { | |
1506 | struct pglist_data *pgdat = zone->zone_pgdat; | |
1507 | unsigned long present_pages = 0; | |
1508 | enum zone_type zt, zone_last = ZONE_NORMAL; | |
1509 | ||
1510 | /* | |
1511 | * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] | |
1512 | * contains nodes which have zones of 0...ZONE_NORMAL, | |
1513 | * set zone_last to ZONE_NORMAL. | |
1514 | * | |
1515 | * If we don't have HIGHMEM nor movable node, | |
1516 | * node_states[N_NORMAL_MEMORY] contains nodes which have zones of | |
1517 | * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. | |
1518 | */ | |
1519 | if (N_MEMORY == N_NORMAL_MEMORY) | |
1520 | zone_last = ZONE_MOVABLE; | |
1521 | ||
1522 | /* | |
1523 | * check whether node_states[N_NORMAL_MEMORY] will be changed. | |
1524 | * If the memory to be offline is in a zone of 0...zone_last, | |
1525 | * and it is the last present memory, 0...zone_last will | |
1526 | * become empty after offline , thus we can determind we will | |
1527 | * need to clear the node from node_states[N_NORMAL_MEMORY]. | |
1528 | */ | |
1529 | for (zt = 0; zt <= zone_last; zt++) | |
1530 | present_pages += pgdat->node_zones[zt].present_pages; | |
1531 | if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) | |
1532 | arg->status_change_nid_normal = zone_to_nid(zone); | |
1533 | else | |
1534 | arg->status_change_nid_normal = -1; | |
1535 | ||
1536 | #ifdef CONFIG_HIGHMEM | |
1537 | /* | |
1538 | * If we have movable node, node_states[N_HIGH_MEMORY] | |
1539 | * contains nodes which have zones of 0...ZONE_HIGHMEM, | |
1540 | * set zone_last to ZONE_HIGHMEM. | |
1541 | * | |
1542 | * If we don't have movable node, node_states[N_NORMAL_MEMORY] | |
1543 | * contains nodes which have zones of 0...ZONE_MOVABLE, | |
1544 | * set zone_last to ZONE_MOVABLE. | |
1545 | */ | |
1546 | zone_last = ZONE_HIGHMEM; | |
1547 | if (N_MEMORY == N_HIGH_MEMORY) | |
1548 | zone_last = ZONE_MOVABLE; | |
1549 | ||
1550 | for (; zt <= zone_last; zt++) | |
1551 | present_pages += pgdat->node_zones[zt].present_pages; | |
1552 | if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) | |
1553 | arg->status_change_nid_high = zone_to_nid(zone); | |
1554 | else | |
1555 | arg->status_change_nid_high = -1; | |
1556 | #else | |
1557 | arg->status_change_nid_high = arg->status_change_nid_normal; | |
1558 | #endif | |
1559 | ||
1560 | /* | |
1561 | * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE | |
1562 | */ | |
1563 | zone_last = ZONE_MOVABLE; | |
1564 | ||
1565 | /* | |
1566 | * check whether node_states[N_HIGH_MEMORY] will be changed | |
1567 | * If we try to offline the last present @nr_pages from the node, | |
1568 | * we can determind we will need to clear the node from | |
1569 | * node_states[N_HIGH_MEMORY]. | |
1570 | */ | |
1571 | for (; zt <= zone_last; zt++) | |
1572 | present_pages += pgdat->node_zones[zt].present_pages; | |
1573 | if (nr_pages >= present_pages) | |
1574 | arg->status_change_nid = zone_to_nid(zone); | |
1575 | else | |
1576 | arg->status_change_nid = -1; | |
1577 | } | |
1578 | ||
1579 | static void node_states_clear_node(int node, struct memory_notify *arg) | |
1580 | { | |
1581 | if (arg->status_change_nid_normal >= 0) | |
1582 | node_clear_state(node, N_NORMAL_MEMORY); | |
1583 | ||
1584 | if ((N_MEMORY != N_NORMAL_MEMORY) && | |
1585 | (arg->status_change_nid_high >= 0)) | |
1586 | node_clear_state(node, N_HIGH_MEMORY); | |
1587 | ||
1588 | if ((N_MEMORY != N_HIGH_MEMORY) && | |
1589 | (arg->status_change_nid >= 0)) | |
1590 | node_clear_state(node, N_MEMORY); | |
1591 | } | |
1592 | ||
1593 | static int __ref __offline_pages(unsigned long start_pfn, | |
1594 | unsigned long end_pfn) | |
1595 | { | |
1596 | unsigned long pfn, nr_pages; | |
1597 | long offlined_pages; | |
1598 | int ret, node; | |
1599 | unsigned long flags; | |
1600 | unsigned long valid_start, valid_end; | |
1601 | struct zone *zone; | |
1602 | struct memory_notify arg; | |
1603 | ||
1604 | /* at least, alignment against pageblock is necessary */ | |
1605 | if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) | |
1606 | return -EINVAL; | |
1607 | if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) | |
1608 | return -EINVAL; | |
1609 | /* This makes hotplug much easier...and readable. | |
1610 | we assume this for now. .*/ | |
1611 | if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end)) | |
1612 | return -EINVAL; | |
1613 | ||
1614 | zone = page_zone(pfn_to_page(valid_start)); | |
1615 | node = zone_to_nid(zone); | |
1616 | nr_pages = end_pfn - start_pfn; | |
1617 | ||
1618 | /* set above range as isolated */ | |
1619 | ret = start_isolate_page_range(start_pfn, end_pfn, | |
1620 | MIGRATE_MOVABLE, true); | |
1621 | if (ret) | |
1622 | return ret; | |
1623 | ||
1624 | arg.start_pfn = start_pfn; | |
1625 | arg.nr_pages = nr_pages; | |
1626 | node_states_check_changes_offline(nr_pages, zone, &arg); | |
1627 | ||
1628 | ret = memory_notify(MEM_GOING_OFFLINE, &arg); | |
1629 | ret = notifier_to_errno(ret); | |
1630 | if (ret) | |
1631 | goto failed_removal; | |
1632 | ||
1633 | pfn = start_pfn; | |
1634 | repeat: | |
1635 | /* start memory hot removal */ | |
1636 | ret = -EINTR; | |
1637 | if (signal_pending(current)) | |
1638 | goto failed_removal; | |
1639 | ||
1640 | cond_resched(); | |
1641 | lru_add_drain_all(); | |
1642 | drain_all_pages(zone); | |
1643 | ||
1644 | pfn = scan_movable_pages(start_pfn, end_pfn); | |
1645 | if (pfn) { /* We have movable pages */ | |
1646 | ret = do_migrate_range(pfn, end_pfn); | |
1647 | goto repeat; | |
1648 | } | |
1649 | ||
1650 | /* | |
1651 | * dissolve free hugepages in the memory block before doing offlining | |
1652 | * actually in order to make hugetlbfs's object counting consistent. | |
1653 | */ | |
1654 | ret = dissolve_free_huge_pages(start_pfn, end_pfn); | |
1655 | if (ret) | |
1656 | goto failed_removal; | |
1657 | /* check again */ | |
1658 | offlined_pages = check_pages_isolated(start_pfn, end_pfn); | |
1659 | if (offlined_pages < 0) | |
1660 | goto repeat; | |
1661 | pr_info("Offlined Pages %ld\n", offlined_pages); | |
1662 | /* Ok, all of our target is isolated. | |
1663 | We cannot do rollback at this point. */ | |
1664 | offline_isolated_pages(start_pfn, end_pfn); | |
1665 | /* reset pagetype flags and makes migrate type to be MOVABLE */ | |
1666 | undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); | |
1667 | /* removal success */ | |
1668 | adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); | |
1669 | zone->present_pages -= offlined_pages; | |
1670 | ||
1671 | pgdat_resize_lock(zone->zone_pgdat, &flags); | |
1672 | zone->zone_pgdat->node_present_pages -= offlined_pages; | |
1673 | pgdat_resize_unlock(zone->zone_pgdat, &flags); | |
1674 | ||
1675 | init_per_zone_wmark_min(); | |
1676 | ||
1677 | if (!populated_zone(zone)) { | |
1678 | zone_pcp_reset(zone); | |
1679 | build_all_zonelists(NULL); | |
1680 | } else | |
1681 | zone_pcp_update(zone); | |
1682 | ||
1683 | node_states_clear_node(node, &arg); | |
1684 | if (arg.status_change_nid >= 0) { | |
1685 | kswapd_stop(node); | |
1686 | kcompactd_stop(node); | |
1687 | } | |
1688 | ||
1689 | vm_total_pages = nr_free_pagecache_pages(); | |
1690 | writeback_set_ratelimit(); | |
1691 | ||
1692 | memory_notify(MEM_OFFLINE, &arg); | |
1693 | return 0; | |
1694 | ||
1695 | failed_removal: | |
1696 | pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n", | |
1697 | (unsigned long long) start_pfn << PAGE_SHIFT, | |
1698 | ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); | |
1699 | memory_notify(MEM_CANCEL_OFFLINE, &arg); | |
1700 | /* pushback to free area */ | |
1701 | undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); | |
1702 | return ret; | |
1703 | } | |
1704 | ||
1705 | /* Must be protected by mem_hotplug_begin() or a device_lock */ | |
1706 | int offline_pages(unsigned long start_pfn, unsigned long nr_pages) | |
1707 | { | |
1708 | return __offline_pages(start_pfn, start_pfn + nr_pages); | |
1709 | } | |
1710 | #endif /* CONFIG_MEMORY_HOTREMOVE */ | |
1711 | ||
1712 | /** | |
1713 | * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) | |
1714 | * @start_pfn: start pfn of the memory range | |
1715 | * @end_pfn: end pfn of the memory range | |
1716 | * @arg: argument passed to func | |
1717 | * @func: callback for each memory section walked | |
1718 | * | |
1719 | * This function walks through all present mem sections in range | |
1720 | * [start_pfn, end_pfn) and call func on each mem section. | |
1721 | * | |
1722 | * Returns the return value of func. | |
1723 | */ | |
1724 | int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, | |
1725 | void *arg, int (*func)(struct memory_block *, void *)) | |
1726 | { | |
1727 | struct memory_block *mem = NULL; | |
1728 | struct mem_section *section; | |
1729 | unsigned long pfn, section_nr; | |
1730 | int ret; | |
1731 | ||
1732 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { | |
1733 | section_nr = pfn_to_section_nr(pfn); | |
1734 | if (!present_section_nr(section_nr)) | |
1735 | continue; | |
1736 | ||
1737 | section = __nr_to_section(section_nr); | |
1738 | /* same memblock? */ | |
1739 | if (mem) | |
1740 | if ((section_nr >= mem->start_section_nr) && | |
1741 | (section_nr <= mem->end_section_nr)) | |
1742 | continue; | |
1743 | ||
1744 | mem = find_memory_block_hinted(section, mem); | |
1745 | if (!mem) | |
1746 | continue; | |
1747 | ||
1748 | ret = func(mem, arg); | |
1749 | if (ret) { | |
1750 | kobject_put(&mem->dev.kobj); | |
1751 | return ret; | |
1752 | } | |
1753 | } | |
1754 | ||
1755 | if (mem) | |
1756 | kobject_put(&mem->dev.kobj); | |
1757 | ||
1758 | return 0; | |
1759 | } | |
1760 | ||
1761 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
1762 | static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) | |
1763 | { | |
1764 | int ret = !is_memblock_offlined(mem); | |
1765 | ||
1766 | if (unlikely(ret)) { | |
1767 | phys_addr_t beginpa, endpa; | |
1768 | ||
1769 | beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); | |
1770 | endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; | |
1771 | pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", | |
1772 | &beginpa, &endpa); | |
1773 | } | |
1774 | ||
1775 | return ret; | |
1776 | } | |
1777 | ||
1778 | static int check_cpu_on_node(pg_data_t *pgdat) | |
1779 | { | |
1780 | int cpu; | |
1781 | ||
1782 | for_each_present_cpu(cpu) { | |
1783 | if (cpu_to_node(cpu) == pgdat->node_id) | |
1784 | /* | |
1785 | * the cpu on this node isn't removed, and we can't | |
1786 | * offline this node. | |
1787 | */ | |
1788 | return -EBUSY; | |
1789 | } | |
1790 | ||
1791 | return 0; | |
1792 | } | |
1793 | ||
1794 | static void unmap_cpu_on_node(pg_data_t *pgdat) | |
1795 | { | |
1796 | #ifdef CONFIG_ACPI_NUMA | |
1797 | int cpu; | |
1798 | ||
1799 | for_each_possible_cpu(cpu) | |
1800 | if (cpu_to_node(cpu) == pgdat->node_id) | |
1801 | numa_clear_node(cpu); | |
1802 | #endif | |
1803 | } | |
1804 | ||
1805 | static int check_and_unmap_cpu_on_node(pg_data_t *pgdat) | |
1806 | { | |
1807 | int ret; | |
1808 | ||
1809 | ret = check_cpu_on_node(pgdat); | |
1810 | if (ret) | |
1811 | return ret; | |
1812 | ||
1813 | /* | |
1814 | * the node will be offlined when we come here, so we can clear | |
1815 | * the cpu_to_node() now. | |
1816 | */ | |
1817 | ||
1818 | unmap_cpu_on_node(pgdat); | |
1819 | return 0; | |
1820 | } | |
1821 | ||
1822 | /** | |
1823 | * try_offline_node | |
1824 | * @nid: the node ID | |
1825 | * | |
1826 | * Offline a node if all memory sections and cpus of the node are removed. | |
1827 | * | |
1828 | * NOTE: The caller must call lock_device_hotplug() to serialize hotplug | |
1829 | * and online/offline operations before this call. | |
1830 | */ | |
1831 | void try_offline_node(int nid) | |
1832 | { | |
1833 | pg_data_t *pgdat = NODE_DATA(nid); | |
1834 | unsigned long start_pfn = pgdat->node_start_pfn; | |
1835 | unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; | |
1836 | unsigned long pfn; | |
1837 | ||
1838 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { | |
1839 | unsigned long section_nr = pfn_to_section_nr(pfn); | |
1840 | ||
1841 | if (!present_section_nr(section_nr)) | |
1842 | continue; | |
1843 | ||
1844 | if (pfn_to_nid(pfn) != nid) | |
1845 | continue; | |
1846 | ||
1847 | /* | |
1848 | * some memory sections of this node are not removed, and we | |
1849 | * can't offline node now. | |
1850 | */ | |
1851 | return; | |
1852 | } | |
1853 | ||
1854 | if (check_and_unmap_cpu_on_node(pgdat)) | |
1855 | return; | |
1856 | ||
1857 | /* | |
1858 | * all memory/cpu of this node are removed, we can offline this | |
1859 | * node now. | |
1860 | */ | |
1861 | node_set_offline(nid); | |
1862 | unregister_one_node(nid); | |
1863 | } | |
1864 | EXPORT_SYMBOL(try_offline_node); | |
1865 | ||
1866 | /** | |
1867 | * remove_memory | |
1868 | * @nid: the node ID | |
1869 | * @start: physical address of the region to remove | |
1870 | * @size: size of the region to remove | |
1871 | * | |
1872 | * NOTE: The caller must call lock_device_hotplug() to serialize hotplug | |
1873 | * and online/offline operations before this call, as required by | |
1874 | * try_offline_node(). | |
1875 | */ | |
1876 | void __ref remove_memory(int nid, u64 start, u64 size) | |
1877 | { | |
1878 | int ret; | |
1879 | ||
1880 | BUG_ON(check_hotplug_memory_range(start, size)); | |
1881 | ||
1882 | mem_hotplug_begin(); | |
1883 | ||
1884 | /* | |
1885 | * All memory blocks must be offlined before removing memory. Check | |
1886 | * whether all memory blocks in question are offline and trigger a BUG() | |
1887 | * if this is not the case. | |
1888 | */ | |
1889 | ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, | |
1890 | check_memblock_offlined_cb); | |
1891 | if (ret) | |
1892 | BUG(); | |
1893 | ||
1894 | /* remove memmap entry */ | |
1895 | firmware_map_remove(start, start + size, "System RAM"); | |
1896 | memblock_free(start, size); | |
1897 | memblock_remove(start, size); | |
1898 | ||
1899 | arch_remove_memory(start, size, NULL); | |
1900 | ||
1901 | try_offline_node(nid); | |
1902 | ||
1903 | mem_hotplug_done(); | |
1904 | } | |
1905 | EXPORT_SYMBOL_GPL(remove_memory); | |
1906 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |