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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/swap.h>
10#include <linux/interrupt.h>
11#include <linux/pagemap.h>
12#include <linux/bootmem.h>
13#include <linux/compiler.h>
14#include <linux/module.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/memory_hotplug.h>
22#include <linux/highmem.h>
23#include <linux/vmalloc.h>
24#include <linux/ioport.h>
25#include <linux/delay.h>
26#include <linux/migrate.h>
27#include <linux/page-isolation.h>
28#include <linux/pfn.h>
29#include <linux/suspend.h>
30#include <linux/mm_inline.h>
31#include <linux/firmware-map.h>
32
33#include <asm/tlbflush.h>
34
35#include "internal.h"
36
37/*
38 * online_page_callback contains pointer to current page onlining function.
39 * Initially it is generic_online_page(). If it is required it could be
40 * changed by calling set_online_page_callback() for callback registration
41 * and restore_online_page_callback() for generic callback restore.
42 */
43
44static void generic_online_page(struct page *page);
45
46static online_page_callback_t online_page_callback = generic_online_page;
47
48DEFINE_MUTEX(mem_hotplug_mutex);
49
50void lock_memory_hotplug(void)
51{
52 mutex_lock(&mem_hotplug_mutex);
53
54 /* for exclusive hibernation if CONFIG_HIBERNATION=y */
55 lock_system_sleep();
56}
57
58void unlock_memory_hotplug(void)
59{
60 unlock_system_sleep();
61 mutex_unlock(&mem_hotplug_mutex);
62}
63
64
65/* add this memory to iomem resource */
66static struct resource *register_memory_resource(u64 start, u64 size)
67{
68 struct resource *res;
69 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
70 BUG_ON(!res);
71
72 res->name = "System RAM";
73 res->start = start;
74 res->end = start + size - 1;
75 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
76 if (request_resource(&iomem_resource, res) < 0) {
77 printk("System RAM resource %llx - %llx cannot be added\n",
78 (unsigned long long)res->start, (unsigned long long)res->end);
79 kfree(res);
80 res = NULL;
81 }
82 return res;
83}
84
85static void release_memory_resource(struct resource *res)
86{
87 if (!res)
88 return;
89 release_resource(res);
90 kfree(res);
91 return;
92}
93
94#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
95#ifndef CONFIG_SPARSEMEM_VMEMMAP
96static void get_page_bootmem(unsigned long info, struct page *page,
97 unsigned long type)
98{
99 page->lru.next = (struct list_head *) type;
100 SetPagePrivate(page);
101 set_page_private(page, info);
102 atomic_inc(&page->_count);
103}
104
105/* reference to __meminit __free_pages_bootmem is valid
106 * so use __ref to tell modpost not to generate a warning */
107void __ref put_page_bootmem(struct page *page)
108{
109 unsigned long type;
110
111 type = (unsigned long) page->lru.next;
112 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
113 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
114
115 if (atomic_dec_return(&page->_count) == 1) {
116 ClearPagePrivate(page);
117 set_page_private(page, 0);
118 INIT_LIST_HEAD(&page->lru);
119 __free_pages_bootmem(page, 0);
120 }
121
122}
123
124static void register_page_bootmem_info_section(unsigned long start_pfn)
125{
126 unsigned long *usemap, mapsize, section_nr, i;
127 struct mem_section *ms;
128 struct page *page, *memmap;
129
130 if (!pfn_valid(start_pfn))
131 return;
132
133 section_nr = pfn_to_section_nr(start_pfn);
134 ms = __nr_to_section(section_nr);
135
136 /* Get section's memmap address */
137 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
138
139 /*
140 * Get page for the memmap's phys address
141 * XXX: need more consideration for sparse_vmemmap...
142 */
143 page = virt_to_page(memmap);
144 mapsize = sizeof(struct page) * PAGES_PER_SECTION;
145 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
146
147 /* remember memmap's page */
148 for (i = 0; i < mapsize; i++, page++)
149 get_page_bootmem(section_nr, page, SECTION_INFO);
150
151 usemap = __nr_to_section(section_nr)->pageblock_flags;
152 page = virt_to_page(usemap);
153
154 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
155
156 for (i = 0; i < mapsize; i++, page++)
157 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
158
159}
160
161void register_page_bootmem_info_node(struct pglist_data *pgdat)
162{
163 unsigned long i, pfn, end_pfn, nr_pages;
164 int node = pgdat->node_id;
165 struct page *page;
166 struct zone *zone;
167
168 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
169 page = virt_to_page(pgdat);
170
171 for (i = 0; i < nr_pages; i++, page++)
172 get_page_bootmem(node, page, NODE_INFO);
173
174 zone = &pgdat->node_zones[0];
175 for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
176 if (zone->wait_table) {
177 nr_pages = zone->wait_table_hash_nr_entries
178 * sizeof(wait_queue_head_t);
179 nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
180 page = virt_to_page(zone->wait_table);
181
182 for (i = 0; i < nr_pages; i++, page++)
183 get_page_bootmem(node, page, NODE_INFO);
184 }
185 }
186
187 pfn = pgdat->node_start_pfn;
188 end_pfn = pfn + pgdat->node_spanned_pages;
189
190 /* register_section info */
191 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
192 register_page_bootmem_info_section(pfn);
193
194}
195#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
196
197static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
198 unsigned long end_pfn)
199{
200 unsigned long old_zone_end_pfn;
201
202 zone_span_writelock(zone);
203
204 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
205 if (start_pfn < zone->zone_start_pfn)
206 zone->zone_start_pfn = start_pfn;
207
208 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
209 zone->zone_start_pfn;
210
211 zone_span_writeunlock(zone);
212}
213
214static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
215 unsigned long end_pfn)
216{
217 unsigned long old_pgdat_end_pfn =
218 pgdat->node_start_pfn + pgdat->node_spanned_pages;
219
220 if (start_pfn < pgdat->node_start_pfn)
221 pgdat->node_start_pfn = start_pfn;
222
223 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
224 pgdat->node_start_pfn;
225}
226
227static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
228{
229 struct pglist_data *pgdat = zone->zone_pgdat;
230 int nr_pages = PAGES_PER_SECTION;
231 int nid = pgdat->node_id;
232 int zone_type;
233 unsigned long flags;
234
235 zone_type = zone - pgdat->node_zones;
236 if (!zone->wait_table) {
237 int ret;
238
239 ret = init_currently_empty_zone(zone, phys_start_pfn,
240 nr_pages, MEMMAP_HOTPLUG);
241 if (ret)
242 return ret;
243 }
244 pgdat_resize_lock(zone->zone_pgdat, &flags);
245 grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
246 grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
247 phys_start_pfn + nr_pages);
248 pgdat_resize_unlock(zone->zone_pgdat, &flags);
249 memmap_init_zone(nr_pages, nid, zone_type,
250 phys_start_pfn, MEMMAP_HOTPLUG);
251 return 0;
252}
253
254static int __meminit __add_section(int nid, struct zone *zone,
255 unsigned long phys_start_pfn)
256{
257 int nr_pages = PAGES_PER_SECTION;
258 int ret;
259
260 if (pfn_valid(phys_start_pfn))
261 return -EEXIST;
262
263 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
264
265 if (ret < 0)
266 return ret;
267
268 ret = __add_zone(zone, phys_start_pfn);
269
270 if (ret < 0)
271 return ret;
272
273 return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
274}
275
276#ifdef CONFIG_SPARSEMEM_VMEMMAP
277static int __remove_section(struct zone *zone, struct mem_section *ms)
278{
279 /*
280 * XXX: Freeing memmap with vmemmap is not implement yet.
281 * This should be removed later.
282 */
283 return -EBUSY;
284}
285#else
286static int __remove_section(struct zone *zone, struct mem_section *ms)
287{
288 unsigned long flags;
289 struct pglist_data *pgdat = zone->zone_pgdat;
290 int ret = -EINVAL;
291
292 if (!valid_section(ms))
293 return ret;
294
295 ret = unregister_memory_section(ms);
296 if (ret)
297 return ret;
298
299 pgdat_resize_lock(pgdat, &flags);
300 sparse_remove_one_section(zone, ms);
301 pgdat_resize_unlock(pgdat, &flags);
302 return 0;
303}
304#endif
305
306/*
307 * Reasonably generic function for adding memory. It is
308 * expected that archs that support memory hotplug will
309 * call this function after deciding the zone to which to
310 * add the new pages.
311 */
312int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
313 unsigned long nr_pages)
314{
315 unsigned long i;
316 int err = 0;
317 int start_sec, end_sec;
318 /* during initialize mem_map, align hot-added range to section */
319 start_sec = pfn_to_section_nr(phys_start_pfn);
320 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
321
322 for (i = start_sec; i <= end_sec; i++) {
323 err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
324
325 /*
326 * EEXIST is finally dealt with by ioresource collision
327 * check. see add_memory() => register_memory_resource()
328 * Warning will be printed if there is collision.
329 */
330 if (err && (err != -EEXIST))
331 break;
332 err = 0;
333 }
334
335 return err;
336}
337EXPORT_SYMBOL_GPL(__add_pages);
338
339/**
340 * __remove_pages() - remove sections of pages from a zone
341 * @zone: zone from which pages need to be removed
342 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
343 * @nr_pages: number of pages to remove (must be multiple of section size)
344 *
345 * Generic helper function to remove section mappings and sysfs entries
346 * for the section of the memory we are removing. Caller needs to make
347 * sure that pages are marked reserved and zones are adjust properly by
348 * calling offline_pages().
349 */
350int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
351 unsigned long nr_pages)
352{
353 unsigned long i, ret = 0;
354 int sections_to_remove;
355
356 /*
357 * We can only remove entire sections
358 */
359 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
360 BUG_ON(nr_pages % PAGES_PER_SECTION);
361
362 sections_to_remove = nr_pages / PAGES_PER_SECTION;
363 for (i = 0; i < sections_to_remove; i++) {
364 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
365 release_mem_region(pfn << PAGE_SHIFT,
366 PAGES_PER_SECTION << PAGE_SHIFT);
367 ret = __remove_section(zone, __pfn_to_section(pfn));
368 if (ret)
369 break;
370 }
371 return ret;
372}
373EXPORT_SYMBOL_GPL(__remove_pages);
374
375int set_online_page_callback(online_page_callback_t callback)
376{
377 int rc = -EINVAL;
378
379 lock_memory_hotplug();
380
381 if (online_page_callback == generic_online_page) {
382 online_page_callback = callback;
383 rc = 0;
384 }
385
386 unlock_memory_hotplug();
387
388 return rc;
389}
390EXPORT_SYMBOL_GPL(set_online_page_callback);
391
392int restore_online_page_callback(online_page_callback_t callback)
393{
394 int rc = -EINVAL;
395
396 lock_memory_hotplug();
397
398 if (online_page_callback == callback) {
399 online_page_callback = generic_online_page;
400 rc = 0;
401 }
402
403 unlock_memory_hotplug();
404
405 return rc;
406}
407EXPORT_SYMBOL_GPL(restore_online_page_callback);
408
409void __online_page_set_limits(struct page *page)
410{
411 unsigned long pfn = page_to_pfn(page);
412
413 if (pfn >= num_physpages)
414 num_physpages = pfn + 1;
415}
416EXPORT_SYMBOL_GPL(__online_page_set_limits);
417
418void __online_page_increment_counters(struct page *page)
419{
420 totalram_pages++;
421
422#ifdef CONFIG_HIGHMEM
423 if (PageHighMem(page))
424 totalhigh_pages++;
425#endif
426}
427EXPORT_SYMBOL_GPL(__online_page_increment_counters);
428
429void __online_page_free(struct page *page)
430{
431 ClearPageReserved(page);
432 init_page_count(page);
433 __free_page(page);
434}
435EXPORT_SYMBOL_GPL(__online_page_free);
436
437static void generic_online_page(struct page *page)
438{
439 __online_page_set_limits(page);
440 __online_page_increment_counters(page);
441 __online_page_free(page);
442}
443
444static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
445 void *arg)
446{
447 unsigned long i;
448 unsigned long onlined_pages = *(unsigned long *)arg;
449 struct page *page;
450 if (PageReserved(pfn_to_page(start_pfn)))
451 for (i = 0; i < nr_pages; i++) {
452 page = pfn_to_page(start_pfn + i);
453 (*online_page_callback)(page);
454 onlined_pages++;
455 }
456 *(unsigned long *)arg = onlined_pages;
457 return 0;
458}
459
460
461int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
462{
463 unsigned long onlined_pages = 0;
464 struct zone *zone;
465 int need_zonelists_rebuild = 0;
466 int nid;
467 int ret;
468 struct memory_notify arg;
469
470 lock_memory_hotplug();
471 arg.start_pfn = pfn;
472 arg.nr_pages = nr_pages;
473 arg.status_change_nid = -1;
474
475 nid = page_to_nid(pfn_to_page(pfn));
476 if (node_present_pages(nid) == 0)
477 arg.status_change_nid = nid;
478
479 ret = memory_notify(MEM_GOING_ONLINE, &arg);
480 ret = notifier_to_errno(ret);
481 if (ret) {
482 memory_notify(MEM_CANCEL_ONLINE, &arg);
483 unlock_memory_hotplug();
484 return ret;
485 }
486 /*
487 * This doesn't need a lock to do pfn_to_page().
488 * The section can't be removed here because of the
489 * memory_block->state_mutex.
490 */
491 zone = page_zone(pfn_to_page(pfn));
492 /*
493 * If this zone is not populated, then it is not in zonelist.
494 * This means the page allocator ignores this zone.
495 * So, zonelist must be updated after online.
496 */
497 mutex_lock(&zonelists_mutex);
498 if (!populated_zone(zone))
499 need_zonelists_rebuild = 1;
500
501 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
502 online_pages_range);
503 if (ret) {
504 mutex_unlock(&zonelists_mutex);
505 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
506 nr_pages, pfn);
507 memory_notify(MEM_CANCEL_ONLINE, &arg);
508 unlock_memory_hotplug();
509 return ret;
510 }
511
512 zone->present_pages += onlined_pages;
513 zone->zone_pgdat->node_present_pages += onlined_pages;
514 if (need_zonelists_rebuild)
515 build_all_zonelists(zone);
516 else
517 zone_pcp_update(zone);
518
519 mutex_unlock(&zonelists_mutex);
520
521 init_per_zone_wmark_min();
522
523 if (onlined_pages) {
524 kswapd_run(zone_to_nid(zone));
525 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
526 }
527
528 vm_total_pages = nr_free_pagecache_pages();
529
530 writeback_set_ratelimit();
531
532 if (onlined_pages)
533 memory_notify(MEM_ONLINE, &arg);
534 unlock_memory_hotplug();
535
536 return 0;
537}
538#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
539
540/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
541static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
542{
543 struct pglist_data *pgdat;
544 unsigned long zones_size[MAX_NR_ZONES] = {0};
545 unsigned long zholes_size[MAX_NR_ZONES] = {0};
546 unsigned long start_pfn = start >> PAGE_SHIFT;
547
548 pgdat = arch_alloc_nodedata(nid);
549 if (!pgdat)
550 return NULL;
551
552 arch_refresh_nodedata(nid, pgdat);
553
554 /* we can use NODE_DATA(nid) from here */
555
556 /* init node's zones as empty zones, we don't have any present pages.*/
557 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
558
559 /*
560 * The node we allocated has no zone fallback lists. For avoiding
561 * to access not-initialized zonelist, build here.
562 */
563 mutex_lock(&zonelists_mutex);
564 build_all_zonelists(NULL);
565 mutex_unlock(&zonelists_mutex);
566
567 return pgdat;
568}
569
570static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
571{
572 arch_refresh_nodedata(nid, NULL);
573 arch_free_nodedata(pgdat);
574 return;
575}
576
577
578/*
579 * called by cpu_up() to online a node without onlined memory.
580 */
581int mem_online_node(int nid)
582{
583 pg_data_t *pgdat;
584 int ret;
585
586 lock_memory_hotplug();
587 pgdat = hotadd_new_pgdat(nid, 0);
588 if (!pgdat) {
589 ret = -ENOMEM;
590 goto out;
591 }
592 node_set_online(nid);
593 ret = register_one_node(nid);
594 BUG_ON(ret);
595
596out:
597 unlock_memory_hotplug();
598 return ret;
599}
600
601/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
602int __ref add_memory(int nid, u64 start, u64 size)
603{
604 pg_data_t *pgdat = NULL;
605 int new_pgdat = 0;
606 struct resource *res;
607 int ret;
608
609 lock_memory_hotplug();
610
611 res = register_memory_resource(start, size);
612 ret = -EEXIST;
613 if (!res)
614 goto out;
615
616 if (!node_online(nid)) {
617 pgdat = hotadd_new_pgdat(nid, start);
618 ret = -ENOMEM;
619 if (!pgdat)
620 goto out;
621 new_pgdat = 1;
622 }
623
624 /* call arch's memory hotadd */
625 ret = arch_add_memory(nid, start, size);
626
627 if (ret < 0)
628 goto error;
629
630 /* we online node here. we can't roll back from here. */
631 node_set_online(nid);
632
633 if (new_pgdat) {
634 ret = register_one_node(nid);
635 /*
636 * If sysfs file of new node can't create, cpu on the node
637 * can't be hot-added. There is no rollback way now.
638 * So, check by BUG_ON() to catch it reluctantly..
639 */
640 BUG_ON(ret);
641 }
642
643 /* create new memmap entry */
644 firmware_map_add_hotplug(start, start + size, "System RAM");
645
646 goto out;
647
648error:
649 /* rollback pgdat allocation and others */
650 if (new_pgdat)
651 rollback_node_hotadd(nid, pgdat);
652 if (res)
653 release_memory_resource(res);
654
655out:
656 unlock_memory_hotplug();
657 return ret;
658}
659EXPORT_SYMBOL_GPL(add_memory);
660
661#ifdef CONFIG_MEMORY_HOTREMOVE
662/*
663 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
664 * set and the size of the free page is given by page_order(). Using this,
665 * the function determines if the pageblock contains only free pages.
666 * Due to buddy contraints, a free page at least the size of a pageblock will
667 * be located at the start of the pageblock
668 */
669static inline int pageblock_free(struct page *page)
670{
671 return PageBuddy(page) && page_order(page) >= pageblock_order;
672}
673
674/* Return the start of the next active pageblock after a given page */
675static struct page *next_active_pageblock(struct page *page)
676{
677 /* Ensure the starting page is pageblock-aligned */
678 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
679
680 /* If the entire pageblock is free, move to the end of free page */
681 if (pageblock_free(page)) {
682 int order;
683 /* be careful. we don't have locks, page_order can be changed.*/
684 order = page_order(page);
685 if ((order < MAX_ORDER) && (order >= pageblock_order))
686 return page + (1 << order);
687 }
688
689 return page + pageblock_nr_pages;
690}
691
692/* Checks if this range of memory is likely to be hot-removable. */
693int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
694{
695 struct page *page = pfn_to_page(start_pfn);
696 struct page *end_page = page + nr_pages;
697
698 /* Check the starting page of each pageblock within the range */
699 for (; page < end_page; page = next_active_pageblock(page)) {
700 if (!is_pageblock_removable_nolock(page))
701 return 0;
702 cond_resched();
703 }
704
705 /* All pageblocks in the memory block are likely to be hot-removable */
706 return 1;
707}
708
709/*
710 * Confirm all pages in a range [start, end) is belongs to the same zone.
711 */
712static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
713{
714 unsigned long pfn;
715 struct zone *zone = NULL;
716 struct page *page;
717 int i;
718 for (pfn = start_pfn;
719 pfn < end_pfn;
720 pfn += MAX_ORDER_NR_PAGES) {
721 i = 0;
722 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
723 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
724 i++;
725 if (i == MAX_ORDER_NR_PAGES)
726 continue;
727 page = pfn_to_page(pfn + i);
728 if (zone && page_zone(page) != zone)
729 return 0;
730 zone = page_zone(page);
731 }
732 return 1;
733}
734
735/*
736 * Scanning pfn is much easier than scanning lru list.
737 * Scan pfn from start to end and Find LRU page.
738 */
739static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
740{
741 unsigned long pfn;
742 struct page *page;
743 for (pfn = start; pfn < end; pfn++) {
744 if (pfn_valid(pfn)) {
745 page = pfn_to_page(pfn);
746 if (PageLRU(page))
747 return pfn;
748 }
749 }
750 return 0;
751}
752
753static struct page *
754hotremove_migrate_alloc(struct page *page, unsigned long private, int **x)
755{
756 /* This should be improooooved!! */
757 return alloc_page(GFP_HIGHUSER_MOVABLE);
758}
759
760#define NR_OFFLINE_AT_ONCE_PAGES (256)
761static int
762do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
763{
764 unsigned long pfn;
765 struct page *page;
766 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
767 int not_managed = 0;
768 int ret = 0;
769 LIST_HEAD(source);
770
771 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
772 if (!pfn_valid(pfn))
773 continue;
774 page = pfn_to_page(pfn);
775 if (!get_page_unless_zero(page))
776 continue;
777 /*
778 * We can skip free pages. And we can only deal with pages on
779 * LRU.
780 */
781 ret = isolate_lru_page(page);
782 if (!ret) { /* Success */
783 put_page(page);
784 list_add_tail(&page->lru, &source);
785 move_pages--;
786 inc_zone_page_state(page, NR_ISOLATED_ANON +
787 page_is_file_cache(page));
788
789 } else {
790#ifdef CONFIG_DEBUG_VM
791 printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
792 pfn);
793 dump_page(page);
794#endif
795 put_page(page);
796 /* Because we don't have big zone->lock. we should
797 check this again here. */
798 if (page_count(page)) {
799 not_managed++;
800 ret = -EBUSY;
801 break;
802 }
803 }
804 }
805 if (!list_empty(&source)) {
806 if (not_managed) {
807 putback_lru_pages(&source);
808 goto out;
809 }
810 /* this function returns # of failed pages */
811 ret = migrate_pages(&source, hotremove_migrate_alloc, 0,
812 true, true);
813 if (ret)
814 putback_lru_pages(&source);
815 }
816out:
817 return ret;
818}
819
820/*
821 * remove from free_area[] and mark all as Reserved.
822 */
823static int
824offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
825 void *data)
826{
827 __offline_isolated_pages(start, start + nr_pages);
828 return 0;
829}
830
831static void
832offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
833{
834 walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
835 offline_isolated_pages_cb);
836}
837
838/*
839 * Check all pages in range, recoreded as memory resource, are isolated.
840 */
841static int
842check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
843 void *data)
844{
845 int ret;
846 long offlined = *(long *)data;
847 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
848 offlined = nr_pages;
849 if (!ret)
850 *(long *)data += offlined;
851 return ret;
852}
853
854static long
855check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
856{
857 long offlined = 0;
858 int ret;
859
860 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
861 check_pages_isolated_cb);
862 if (ret < 0)
863 offlined = (long)ret;
864 return offlined;
865}
866
867static int __ref offline_pages(unsigned long start_pfn,
868 unsigned long end_pfn, unsigned long timeout)
869{
870 unsigned long pfn, nr_pages, expire;
871 long offlined_pages;
872 int ret, drain, retry_max, node;
873 struct zone *zone;
874 struct memory_notify arg;
875
876 BUG_ON(start_pfn >= end_pfn);
877 /* at least, alignment against pageblock is necessary */
878 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
879 return -EINVAL;
880 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
881 return -EINVAL;
882 /* This makes hotplug much easier...and readable.
883 we assume this for now. .*/
884 if (!test_pages_in_a_zone(start_pfn, end_pfn))
885 return -EINVAL;
886
887 lock_memory_hotplug();
888
889 zone = page_zone(pfn_to_page(start_pfn));
890 node = zone_to_nid(zone);
891 nr_pages = end_pfn - start_pfn;
892
893 /* set above range as isolated */
894 ret = start_isolate_page_range(start_pfn, end_pfn);
895 if (ret)
896 goto out;
897
898 arg.start_pfn = start_pfn;
899 arg.nr_pages = nr_pages;
900 arg.status_change_nid = -1;
901 if (nr_pages >= node_present_pages(node))
902 arg.status_change_nid = node;
903
904 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
905 ret = notifier_to_errno(ret);
906 if (ret)
907 goto failed_removal;
908
909 pfn = start_pfn;
910 expire = jiffies + timeout;
911 drain = 0;
912 retry_max = 5;
913repeat:
914 /* start memory hot removal */
915 ret = -EAGAIN;
916 if (time_after(jiffies, expire))
917 goto failed_removal;
918 ret = -EINTR;
919 if (signal_pending(current))
920 goto failed_removal;
921 ret = 0;
922 if (drain) {
923 lru_add_drain_all();
924 cond_resched();
925 drain_all_pages();
926 }
927
928 pfn = scan_lru_pages(start_pfn, end_pfn);
929 if (pfn) { /* We have page on LRU */
930 ret = do_migrate_range(pfn, end_pfn);
931 if (!ret) {
932 drain = 1;
933 goto repeat;
934 } else {
935 if (ret < 0)
936 if (--retry_max == 0)
937 goto failed_removal;
938 yield();
939 drain = 1;
940 goto repeat;
941 }
942 }
943 /* drain all zone's lru pagevec, this is asyncronous... */
944 lru_add_drain_all();
945 yield();
946 /* drain pcp pages , this is synchrouns. */
947 drain_all_pages();
948 /* check again */
949 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
950 if (offlined_pages < 0) {
951 ret = -EBUSY;
952 goto failed_removal;
953 }
954 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
955 /* Ok, all of our target is islaoted.
956 We cannot do rollback at this point. */
957 offline_isolated_pages(start_pfn, end_pfn);
958 /* reset pagetype flags and makes migrate type to be MOVABLE */
959 undo_isolate_page_range(start_pfn, end_pfn);
960 /* removal success */
961 zone->present_pages -= offlined_pages;
962 zone->zone_pgdat->node_present_pages -= offlined_pages;
963 totalram_pages -= offlined_pages;
964
965 init_per_zone_wmark_min();
966
967 if (!node_present_pages(node)) {
968 node_clear_state(node, N_HIGH_MEMORY);
969 kswapd_stop(node);
970 }
971
972 vm_total_pages = nr_free_pagecache_pages();
973 writeback_set_ratelimit();
974
975 memory_notify(MEM_OFFLINE, &arg);
976 unlock_memory_hotplug();
977 return 0;
978
979failed_removal:
980 printk(KERN_INFO "memory offlining %lx to %lx failed\n",
981 start_pfn, end_pfn);
982 memory_notify(MEM_CANCEL_OFFLINE, &arg);
983 /* pushback to free area */
984 undo_isolate_page_range(start_pfn, end_pfn);
985
986out:
987 unlock_memory_hotplug();
988 return ret;
989}
990
991int remove_memory(u64 start, u64 size)
992{
993 unsigned long start_pfn, end_pfn;
994
995 start_pfn = PFN_DOWN(start);
996 end_pfn = start_pfn + PFN_DOWN(size);
997 return offline_pages(start_pfn, end_pfn, 120 * HZ);
998}
999#else
1000int remove_memory(u64 start, u64 size)
1001{
1002 return -EINVAL;
1003}
1004#endif /* CONFIG_MEMORY_HOTREMOVE */
1005EXPORT_SYMBOL_GPL(remove_memory);
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/swap.h>
10#include <linux/interrupt.h>
11#include <linux/pagemap.h>
12#include <linux/bootmem.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/memory_hotplug.h>
22#include <linux/highmem.h>
23#include <linux/vmalloc.h>
24#include <linux/ioport.h>
25#include <linux/delay.h>
26#include <linux/migrate.h>
27#include <linux/page-isolation.h>
28#include <linux/pfn.h>
29#include <linux/suspend.h>
30#include <linux/mm_inline.h>
31#include <linux/firmware-map.h>
32
33#include <asm/tlbflush.h>
34
35#include "internal.h"
36
37/*
38 * online_page_callback contains pointer to current page onlining function.
39 * Initially it is generic_online_page(). If it is required it could be
40 * changed by calling set_online_page_callback() for callback registration
41 * and restore_online_page_callback() for generic callback restore.
42 */
43
44static void generic_online_page(struct page *page);
45
46static online_page_callback_t online_page_callback = generic_online_page;
47
48DEFINE_MUTEX(mem_hotplug_mutex);
49
50void lock_memory_hotplug(void)
51{
52 mutex_lock(&mem_hotplug_mutex);
53
54 /* for exclusive hibernation if CONFIG_HIBERNATION=y */
55 lock_system_sleep();
56}
57
58void unlock_memory_hotplug(void)
59{
60 unlock_system_sleep();
61 mutex_unlock(&mem_hotplug_mutex);
62}
63
64
65/* add this memory to iomem resource */
66static struct resource *register_memory_resource(u64 start, u64 size)
67{
68 struct resource *res;
69 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
70 BUG_ON(!res);
71
72 res->name = "System RAM";
73 res->start = start;
74 res->end = start + size - 1;
75 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
76 if (request_resource(&iomem_resource, res) < 0) {
77 printk("System RAM resource %pR cannot be added\n", res);
78 kfree(res);
79 res = NULL;
80 }
81 return res;
82}
83
84static void release_memory_resource(struct resource *res)
85{
86 if (!res)
87 return;
88 release_resource(res);
89 kfree(res);
90 return;
91}
92
93#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
94#ifndef CONFIG_SPARSEMEM_VMEMMAP
95static void get_page_bootmem(unsigned long info, struct page *page,
96 unsigned long type)
97{
98 page->lru.next = (struct list_head *) type;
99 SetPagePrivate(page);
100 set_page_private(page, info);
101 atomic_inc(&page->_count);
102}
103
104/* reference to __meminit __free_pages_bootmem is valid
105 * so use __ref to tell modpost not to generate a warning */
106void __ref put_page_bootmem(struct page *page)
107{
108 unsigned long type;
109
110 type = (unsigned long) page->lru.next;
111 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
112 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
113
114 if (atomic_dec_return(&page->_count) == 1) {
115 ClearPagePrivate(page);
116 set_page_private(page, 0);
117 INIT_LIST_HEAD(&page->lru);
118 __free_pages_bootmem(page, 0);
119 }
120
121}
122
123static void register_page_bootmem_info_section(unsigned long start_pfn)
124{
125 unsigned long *usemap, mapsize, section_nr, i;
126 struct mem_section *ms;
127 struct page *page, *memmap;
128
129 section_nr = pfn_to_section_nr(start_pfn);
130 ms = __nr_to_section(section_nr);
131
132 /* Get section's memmap address */
133 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
134
135 /*
136 * Get page for the memmap's phys address
137 * XXX: need more consideration for sparse_vmemmap...
138 */
139 page = virt_to_page(memmap);
140 mapsize = sizeof(struct page) * PAGES_PER_SECTION;
141 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
142
143 /* remember memmap's page */
144 for (i = 0; i < mapsize; i++, page++)
145 get_page_bootmem(section_nr, page, SECTION_INFO);
146
147 usemap = __nr_to_section(section_nr)->pageblock_flags;
148 page = virt_to_page(usemap);
149
150 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
151
152 for (i = 0; i < mapsize; i++, page++)
153 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
154
155}
156
157void register_page_bootmem_info_node(struct pglist_data *pgdat)
158{
159 unsigned long i, pfn, end_pfn, nr_pages;
160 int node = pgdat->node_id;
161 struct page *page;
162 struct zone *zone;
163
164 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
165 page = virt_to_page(pgdat);
166
167 for (i = 0; i < nr_pages; i++, page++)
168 get_page_bootmem(node, page, NODE_INFO);
169
170 zone = &pgdat->node_zones[0];
171 for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
172 if (zone->wait_table) {
173 nr_pages = zone->wait_table_hash_nr_entries
174 * sizeof(wait_queue_head_t);
175 nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
176 page = virt_to_page(zone->wait_table);
177
178 for (i = 0; i < nr_pages; i++, page++)
179 get_page_bootmem(node, page, NODE_INFO);
180 }
181 }
182
183 pfn = pgdat->node_start_pfn;
184 end_pfn = pfn + pgdat->node_spanned_pages;
185
186 /* register_section info */
187 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
188 /*
189 * Some platforms can assign the same pfn to multiple nodes - on
190 * node0 as well as nodeN. To avoid registering a pfn against
191 * multiple nodes we check that this pfn does not already
192 * reside in some other node.
193 */
194 if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
195 register_page_bootmem_info_section(pfn);
196 }
197}
198#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
199
200static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
201 unsigned long end_pfn)
202{
203 unsigned long old_zone_end_pfn;
204
205 zone_span_writelock(zone);
206
207 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
208 if (start_pfn < zone->zone_start_pfn)
209 zone->zone_start_pfn = start_pfn;
210
211 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
212 zone->zone_start_pfn;
213
214 zone_span_writeunlock(zone);
215}
216
217static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
218 unsigned long end_pfn)
219{
220 unsigned long old_pgdat_end_pfn =
221 pgdat->node_start_pfn + pgdat->node_spanned_pages;
222
223 if (start_pfn < pgdat->node_start_pfn)
224 pgdat->node_start_pfn = start_pfn;
225
226 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
227 pgdat->node_start_pfn;
228}
229
230static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
231{
232 struct pglist_data *pgdat = zone->zone_pgdat;
233 int nr_pages = PAGES_PER_SECTION;
234 int nid = pgdat->node_id;
235 int zone_type;
236 unsigned long flags;
237
238 zone_type = zone - pgdat->node_zones;
239 if (!zone->wait_table) {
240 int ret;
241
242 ret = init_currently_empty_zone(zone, phys_start_pfn,
243 nr_pages, MEMMAP_HOTPLUG);
244 if (ret)
245 return ret;
246 }
247 pgdat_resize_lock(zone->zone_pgdat, &flags);
248 grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
249 grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
250 phys_start_pfn + nr_pages);
251 pgdat_resize_unlock(zone->zone_pgdat, &flags);
252 memmap_init_zone(nr_pages, nid, zone_type,
253 phys_start_pfn, MEMMAP_HOTPLUG);
254 return 0;
255}
256
257static int __meminit __add_section(int nid, struct zone *zone,
258 unsigned long phys_start_pfn)
259{
260 int nr_pages = PAGES_PER_SECTION;
261 int ret;
262
263 if (pfn_valid(phys_start_pfn))
264 return -EEXIST;
265
266 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
267
268 if (ret < 0)
269 return ret;
270
271 ret = __add_zone(zone, phys_start_pfn);
272
273 if (ret < 0)
274 return ret;
275
276 return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
277}
278
279#ifdef CONFIG_SPARSEMEM_VMEMMAP
280static int __remove_section(struct zone *zone, struct mem_section *ms)
281{
282 /*
283 * XXX: Freeing memmap with vmemmap is not implement yet.
284 * This should be removed later.
285 */
286 return -EBUSY;
287}
288#else
289static int __remove_section(struct zone *zone, struct mem_section *ms)
290{
291 unsigned long flags;
292 struct pglist_data *pgdat = zone->zone_pgdat;
293 int ret = -EINVAL;
294
295 if (!valid_section(ms))
296 return ret;
297
298 ret = unregister_memory_section(ms);
299 if (ret)
300 return ret;
301
302 pgdat_resize_lock(pgdat, &flags);
303 sparse_remove_one_section(zone, ms);
304 pgdat_resize_unlock(pgdat, &flags);
305 return 0;
306}
307#endif
308
309/*
310 * Reasonably generic function for adding memory. It is
311 * expected that archs that support memory hotplug will
312 * call this function after deciding the zone to which to
313 * add the new pages.
314 */
315int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
316 unsigned long nr_pages)
317{
318 unsigned long i;
319 int err = 0;
320 int start_sec, end_sec;
321 /* during initialize mem_map, align hot-added range to section */
322 start_sec = pfn_to_section_nr(phys_start_pfn);
323 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
324
325 for (i = start_sec; i <= end_sec; i++) {
326 err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
327
328 /*
329 * EEXIST is finally dealt with by ioresource collision
330 * check. see add_memory() => register_memory_resource()
331 * Warning will be printed if there is collision.
332 */
333 if (err && (err != -EEXIST))
334 break;
335 err = 0;
336 }
337
338 return err;
339}
340EXPORT_SYMBOL_GPL(__add_pages);
341
342/**
343 * __remove_pages() - remove sections of pages from a zone
344 * @zone: zone from which pages need to be removed
345 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
346 * @nr_pages: number of pages to remove (must be multiple of section size)
347 *
348 * Generic helper function to remove section mappings and sysfs entries
349 * for the section of the memory we are removing. Caller needs to make
350 * sure that pages are marked reserved and zones are adjust properly by
351 * calling offline_pages().
352 */
353int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
354 unsigned long nr_pages)
355{
356 unsigned long i, ret = 0;
357 int sections_to_remove;
358
359 /*
360 * We can only remove entire sections
361 */
362 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
363 BUG_ON(nr_pages % PAGES_PER_SECTION);
364
365 sections_to_remove = nr_pages / PAGES_PER_SECTION;
366 for (i = 0; i < sections_to_remove; i++) {
367 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
368 release_mem_region(pfn << PAGE_SHIFT,
369 PAGES_PER_SECTION << PAGE_SHIFT);
370 ret = __remove_section(zone, __pfn_to_section(pfn));
371 if (ret)
372 break;
373 }
374 return ret;
375}
376EXPORT_SYMBOL_GPL(__remove_pages);
377
378int set_online_page_callback(online_page_callback_t callback)
379{
380 int rc = -EINVAL;
381
382 lock_memory_hotplug();
383
384 if (online_page_callback == generic_online_page) {
385 online_page_callback = callback;
386 rc = 0;
387 }
388
389 unlock_memory_hotplug();
390
391 return rc;
392}
393EXPORT_SYMBOL_GPL(set_online_page_callback);
394
395int restore_online_page_callback(online_page_callback_t callback)
396{
397 int rc = -EINVAL;
398
399 lock_memory_hotplug();
400
401 if (online_page_callback == callback) {
402 online_page_callback = generic_online_page;
403 rc = 0;
404 }
405
406 unlock_memory_hotplug();
407
408 return rc;
409}
410EXPORT_SYMBOL_GPL(restore_online_page_callback);
411
412void __online_page_set_limits(struct page *page)
413{
414 unsigned long pfn = page_to_pfn(page);
415
416 if (pfn >= num_physpages)
417 num_physpages = pfn + 1;
418}
419EXPORT_SYMBOL_GPL(__online_page_set_limits);
420
421void __online_page_increment_counters(struct page *page)
422{
423 totalram_pages++;
424
425#ifdef CONFIG_HIGHMEM
426 if (PageHighMem(page))
427 totalhigh_pages++;
428#endif
429}
430EXPORT_SYMBOL_GPL(__online_page_increment_counters);
431
432void __online_page_free(struct page *page)
433{
434 ClearPageReserved(page);
435 init_page_count(page);
436 __free_page(page);
437}
438EXPORT_SYMBOL_GPL(__online_page_free);
439
440static void generic_online_page(struct page *page)
441{
442 __online_page_set_limits(page);
443 __online_page_increment_counters(page);
444 __online_page_free(page);
445}
446
447static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
448 void *arg)
449{
450 unsigned long i;
451 unsigned long onlined_pages = *(unsigned long *)arg;
452 struct page *page;
453 if (PageReserved(pfn_to_page(start_pfn)))
454 for (i = 0; i < nr_pages; i++) {
455 page = pfn_to_page(start_pfn + i);
456 (*online_page_callback)(page);
457 onlined_pages++;
458 }
459 *(unsigned long *)arg = onlined_pages;
460 return 0;
461}
462
463
464int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
465{
466 unsigned long onlined_pages = 0;
467 struct zone *zone;
468 int need_zonelists_rebuild = 0;
469 int nid;
470 int ret;
471 struct memory_notify arg;
472
473 lock_memory_hotplug();
474 arg.start_pfn = pfn;
475 arg.nr_pages = nr_pages;
476 arg.status_change_nid = -1;
477
478 nid = page_to_nid(pfn_to_page(pfn));
479 if (node_present_pages(nid) == 0)
480 arg.status_change_nid = nid;
481
482 ret = memory_notify(MEM_GOING_ONLINE, &arg);
483 ret = notifier_to_errno(ret);
484 if (ret) {
485 memory_notify(MEM_CANCEL_ONLINE, &arg);
486 unlock_memory_hotplug();
487 return ret;
488 }
489 /*
490 * This doesn't need a lock to do pfn_to_page().
491 * The section can't be removed here because of the
492 * memory_block->state_mutex.
493 */
494 zone = page_zone(pfn_to_page(pfn));
495 /*
496 * If this zone is not populated, then it is not in zonelist.
497 * This means the page allocator ignores this zone.
498 * So, zonelist must be updated after online.
499 */
500 mutex_lock(&zonelists_mutex);
501 if (!populated_zone(zone))
502 need_zonelists_rebuild = 1;
503
504 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
505 online_pages_range);
506 if (ret) {
507 mutex_unlock(&zonelists_mutex);
508 printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n",
509 (unsigned long long) pfn << PAGE_SHIFT,
510 (((unsigned long long) pfn + nr_pages)
511 << PAGE_SHIFT) - 1);
512 memory_notify(MEM_CANCEL_ONLINE, &arg);
513 unlock_memory_hotplug();
514 return ret;
515 }
516
517 zone->present_pages += onlined_pages;
518 zone->zone_pgdat->node_present_pages += onlined_pages;
519 if (need_zonelists_rebuild)
520 build_all_zonelists(zone);
521 else
522 zone_pcp_update(zone);
523
524 mutex_unlock(&zonelists_mutex);
525
526 init_per_zone_wmark_min();
527
528 if (onlined_pages) {
529 kswapd_run(zone_to_nid(zone));
530 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
531 }
532
533 vm_total_pages = nr_free_pagecache_pages();
534
535 writeback_set_ratelimit();
536
537 if (onlined_pages)
538 memory_notify(MEM_ONLINE, &arg);
539 unlock_memory_hotplug();
540
541 return 0;
542}
543#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
544
545/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
546static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
547{
548 struct pglist_data *pgdat;
549 unsigned long zones_size[MAX_NR_ZONES] = {0};
550 unsigned long zholes_size[MAX_NR_ZONES] = {0};
551 unsigned long start_pfn = start >> PAGE_SHIFT;
552
553 pgdat = arch_alloc_nodedata(nid);
554 if (!pgdat)
555 return NULL;
556
557 arch_refresh_nodedata(nid, pgdat);
558
559 /* we can use NODE_DATA(nid) from here */
560
561 /* init node's zones as empty zones, we don't have any present pages.*/
562 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
563
564 /*
565 * The node we allocated has no zone fallback lists. For avoiding
566 * to access not-initialized zonelist, build here.
567 */
568 mutex_lock(&zonelists_mutex);
569 build_all_zonelists(NULL);
570 mutex_unlock(&zonelists_mutex);
571
572 return pgdat;
573}
574
575static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
576{
577 arch_refresh_nodedata(nid, NULL);
578 arch_free_nodedata(pgdat);
579 return;
580}
581
582
583/*
584 * called by cpu_up() to online a node without onlined memory.
585 */
586int mem_online_node(int nid)
587{
588 pg_data_t *pgdat;
589 int ret;
590
591 lock_memory_hotplug();
592 pgdat = hotadd_new_pgdat(nid, 0);
593 if (!pgdat) {
594 ret = -ENOMEM;
595 goto out;
596 }
597 node_set_online(nid);
598 ret = register_one_node(nid);
599 BUG_ON(ret);
600
601out:
602 unlock_memory_hotplug();
603 return ret;
604}
605
606/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
607int __ref add_memory(int nid, u64 start, u64 size)
608{
609 pg_data_t *pgdat = NULL;
610 int new_pgdat = 0;
611 struct resource *res;
612 int ret;
613
614 lock_memory_hotplug();
615
616 res = register_memory_resource(start, size);
617 ret = -EEXIST;
618 if (!res)
619 goto out;
620
621 if (!node_online(nid)) {
622 pgdat = hotadd_new_pgdat(nid, start);
623 ret = -ENOMEM;
624 if (!pgdat)
625 goto error;
626 new_pgdat = 1;
627 }
628
629 /* call arch's memory hotadd */
630 ret = arch_add_memory(nid, start, size);
631
632 if (ret < 0)
633 goto error;
634
635 /* we online node here. we can't roll back from here. */
636 node_set_online(nid);
637
638 if (new_pgdat) {
639 ret = register_one_node(nid);
640 /*
641 * If sysfs file of new node can't create, cpu on the node
642 * can't be hot-added. There is no rollback way now.
643 * So, check by BUG_ON() to catch it reluctantly..
644 */
645 BUG_ON(ret);
646 }
647
648 /* create new memmap entry */
649 firmware_map_add_hotplug(start, start + size, "System RAM");
650
651 goto out;
652
653error:
654 /* rollback pgdat allocation and others */
655 if (new_pgdat)
656 rollback_node_hotadd(nid, pgdat);
657 if (res)
658 release_memory_resource(res);
659
660out:
661 unlock_memory_hotplug();
662 return ret;
663}
664EXPORT_SYMBOL_GPL(add_memory);
665
666#ifdef CONFIG_MEMORY_HOTREMOVE
667/*
668 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
669 * set and the size of the free page is given by page_order(). Using this,
670 * the function determines if the pageblock contains only free pages.
671 * Due to buddy contraints, a free page at least the size of a pageblock will
672 * be located at the start of the pageblock
673 */
674static inline int pageblock_free(struct page *page)
675{
676 return PageBuddy(page) && page_order(page) >= pageblock_order;
677}
678
679/* Return the start of the next active pageblock after a given page */
680static struct page *next_active_pageblock(struct page *page)
681{
682 /* Ensure the starting page is pageblock-aligned */
683 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
684
685 /* If the entire pageblock is free, move to the end of free page */
686 if (pageblock_free(page)) {
687 int order;
688 /* be careful. we don't have locks, page_order can be changed.*/
689 order = page_order(page);
690 if ((order < MAX_ORDER) && (order >= pageblock_order))
691 return page + (1 << order);
692 }
693
694 return page + pageblock_nr_pages;
695}
696
697/* Checks if this range of memory is likely to be hot-removable. */
698int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
699{
700 struct page *page = pfn_to_page(start_pfn);
701 struct page *end_page = page + nr_pages;
702
703 /* Check the starting page of each pageblock within the range */
704 for (; page < end_page; page = next_active_pageblock(page)) {
705 if (!is_pageblock_removable_nolock(page))
706 return 0;
707 cond_resched();
708 }
709
710 /* All pageblocks in the memory block are likely to be hot-removable */
711 return 1;
712}
713
714/*
715 * Confirm all pages in a range [start, end) is belongs to the same zone.
716 */
717static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
718{
719 unsigned long pfn;
720 struct zone *zone = NULL;
721 struct page *page;
722 int i;
723 for (pfn = start_pfn;
724 pfn < end_pfn;
725 pfn += MAX_ORDER_NR_PAGES) {
726 i = 0;
727 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
728 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
729 i++;
730 if (i == MAX_ORDER_NR_PAGES)
731 continue;
732 page = pfn_to_page(pfn + i);
733 if (zone && page_zone(page) != zone)
734 return 0;
735 zone = page_zone(page);
736 }
737 return 1;
738}
739
740/*
741 * Scanning pfn is much easier than scanning lru list.
742 * Scan pfn from start to end and Find LRU page.
743 */
744static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
745{
746 unsigned long pfn;
747 struct page *page;
748 for (pfn = start; pfn < end; pfn++) {
749 if (pfn_valid(pfn)) {
750 page = pfn_to_page(pfn);
751 if (PageLRU(page))
752 return pfn;
753 }
754 }
755 return 0;
756}
757
758static struct page *
759hotremove_migrate_alloc(struct page *page, unsigned long private, int **x)
760{
761 /* This should be improooooved!! */
762 return alloc_page(GFP_HIGHUSER_MOVABLE);
763}
764
765#define NR_OFFLINE_AT_ONCE_PAGES (256)
766static int
767do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
768{
769 unsigned long pfn;
770 struct page *page;
771 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
772 int not_managed = 0;
773 int ret = 0;
774 LIST_HEAD(source);
775
776 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
777 if (!pfn_valid(pfn))
778 continue;
779 page = pfn_to_page(pfn);
780 if (!get_page_unless_zero(page))
781 continue;
782 /*
783 * We can skip free pages. And we can only deal with pages on
784 * LRU.
785 */
786 ret = isolate_lru_page(page);
787 if (!ret) { /* Success */
788 put_page(page);
789 list_add_tail(&page->lru, &source);
790 move_pages--;
791 inc_zone_page_state(page, NR_ISOLATED_ANON +
792 page_is_file_cache(page));
793
794 } else {
795#ifdef CONFIG_DEBUG_VM
796 printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
797 pfn);
798 dump_page(page);
799#endif
800 put_page(page);
801 /* Because we don't have big zone->lock. we should
802 check this again here. */
803 if (page_count(page)) {
804 not_managed++;
805 ret = -EBUSY;
806 break;
807 }
808 }
809 }
810 if (!list_empty(&source)) {
811 if (not_managed) {
812 putback_lru_pages(&source);
813 goto out;
814 }
815 /* this function returns # of failed pages */
816 ret = migrate_pages(&source, hotremove_migrate_alloc, 0,
817 true, MIGRATE_SYNC);
818 if (ret)
819 putback_lru_pages(&source);
820 }
821out:
822 return ret;
823}
824
825/*
826 * remove from free_area[] and mark all as Reserved.
827 */
828static int
829offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
830 void *data)
831{
832 __offline_isolated_pages(start, start + nr_pages);
833 return 0;
834}
835
836static void
837offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
838{
839 walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
840 offline_isolated_pages_cb);
841}
842
843/*
844 * Check all pages in range, recoreded as memory resource, are isolated.
845 */
846static int
847check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
848 void *data)
849{
850 int ret;
851 long offlined = *(long *)data;
852 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
853 offlined = nr_pages;
854 if (!ret)
855 *(long *)data += offlined;
856 return ret;
857}
858
859static long
860check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
861{
862 long offlined = 0;
863 int ret;
864
865 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
866 check_pages_isolated_cb);
867 if (ret < 0)
868 offlined = (long)ret;
869 return offlined;
870}
871
872static int __ref offline_pages(unsigned long start_pfn,
873 unsigned long end_pfn, unsigned long timeout)
874{
875 unsigned long pfn, nr_pages, expire;
876 long offlined_pages;
877 int ret, drain, retry_max, node;
878 struct zone *zone;
879 struct memory_notify arg;
880
881 BUG_ON(start_pfn >= end_pfn);
882 /* at least, alignment against pageblock is necessary */
883 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
884 return -EINVAL;
885 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
886 return -EINVAL;
887 /* This makes hotplug much easier...and readable.
888 we assume this for now. .*/
889 if (!test_pages_in_a_zone(start_pfn, end_pfn))
890 return -EINVAL;
891
892 lock_memory_hotplug();
893
894 zone = page_zone(pfn_to_page(start_pfn));
895 node = zone_to_nid(zone);
896 nr_pages = end_pfn - start_pfn;
897
898 /* set above range as isolated */
899 ret = start_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
900 if (ret)
901 goto out;
902
903 arg.start_pfn = start_pfn;
904 arg.nr_pages = nr_pages;
905 arg.status_change_nid = -1;
906 if (nr_pages >= node_present_pages(node))
907 arg.status_change_nid = node;
908
909 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
910 ret = notifier_to_errno(ret);
911 if (ret)
912 goto failed_removal;
913
914 pfn = start_pfn;
915 expire = jiffies + timeout;
916 drain = 0;
917 retry_max = 5;
918repeat:
919 /* start memory hot removal */
920 ret = -EAGAIN;
921 if (time_after(jiffies, expire))
922 goto failed_removal;
923 ret = -EINTR;
924 if (signal_pending(current))
925 goto failed_removal;
926 ret = 0;
927 if (drain) {
928 lru_add_drain_all();
929 cond_resched();
930 drain_all_pages();
931 }
932
933 pfn = scan_lru_pages(start_pfn, end_pfn);
934 if (pfn) { /* We have page on LRU */
935 ret = do_migrate_range(pfn, end_pfn);
936 if (!ret) {
937 drain = 1;
938 goto repeat;
939 } else {
940 if (ret < 0)
941 if (--retry_max == 0)
942 goto failed_removal;
943 yield();
944 drain = 1;
945 goto repeat;
946 }
947 }
948 /* drain all zone's lru pagevec, this is asyncronous... */
949 lru_add_drain_all();
950 yield();
951 /* drain pcp pages , this is synchrouns. */
952 drain_all_pages();
953 /* check again */
954 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
955 if (offlined_pages < 0) {
956 ret = -EBUSY;
957 goto failed_removal;
958 }
959 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
960 /* Ok, all of our target is islaoted.
961 We cannot do rollback at this point. */
962 offline_isolated_pages(start_pfn, end_pfn);
963 /* reset pagetype flags and makes migrate type to be MOVABLE */
964 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
965 /* removal success */
966 zone->present_pages -= offlined_pages;
967 zone->zone_pgdat->node_present_pages -= offlined_pages;
968 totalram_pages -= offlined_pages;
969
970 init_per_zone_wmark_min();
971
972 if (!node_present_pages(node)) {
973 node_clear_state(node, N_HIGH_MEMORY);
974 kswapd_stop(node);
975 }
976
977 vm_total_pages = nr_free_pagecache_pages();
978 writeback_set_ratelimit();
979
980 memory_notify(MEM_OFFLINE, &arg);
981 unlock_memory_hotplug();
982 return 0;
983
984failed_removal:
985 printk(KERN_INFO "memory offlining [mem %#010llx-%#010llx] failed\n",
986 (unsigned long long) start_pfn << PAGE_SHIFT,
987 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
988 memory_notify(MEM_CANCEL_OFFLINE, &arg);
989 /* pushback to free area */
990 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
991
992out:
993 unlock_memory_hotplug();
994 return ret;
995}
996
997int remove_memory(u64 start, u64 size)
998{
999 unsigned long start_pfn, end_pfn;
1000
1001 start_pfn = PFN_DOWN(start);
1002 end_pfn = start_pfn + PFN_DOWN(size);
1003 return offline_pages(start_pfn, end_pfn, 120 * HZ);
1004}
1005#else
1006int remove_memory(u64 start, u64 size)
1007{
1008 return -EINVAL;
1009}
1010#endif /* CONFIG_MEMORY_HOTREMOVE */
1011EXPORT_SYMBOL_GPL(remove_memory);