1
2
3
4
5#include <linux/gfp.h>
6#include <linux/list.h>
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/mm.h>
10#include <linux/seq_file.h>
11#include <linux/sysctl.h>
12#include <linux/highmem.h>
13#include <linux/mmu_notifier.h>
14#include <linux/nodemask.h>
15#include <linux/pagemap.h>
16#include <linux/mempolicy.h>
17#include <linux/cpuset.h>
18#include <linux/mutex.h>
19#include <linux/bootmem.h>
20#include <linux/sysfs.h>
21
22#include <asm/page.h>
23#include <asm/pgtable.h>
24#include <asm/io.h>
25
26#include <linux/hugetlb.h>
27#include "internal.h"
28
29const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
30static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
31unsigned long hugepages_treat_as_movable;
32
33static int max_hstate;
34unsigned int default_hstate_idx;
35struct hstate hstates[HUGE_MAX_HSTATE];
36
37__initdata LIST_HEAD(huge_boot_pages);
38
39
40static struct hstate * __initdata parsed_hstate;
41static unsigned long __initdata default_hstate_max_huge_pages;
42static unsigned long __initdata default_hstate_size;
43
44#define for_each_hstate(h) \
45 for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
46
47
48
49
50static DEFINE_SPINLOCK(hugetlb_lock);
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66struct file_region {
67 struct list_head link;
68 long from;
69 long to;
70};
71
72static long region_add(struct list_head *head, long f, long t)
73{
74 struct file_region *rg, *nrg, *trg;
75
76
77 list_for_each_entry(rg, head, link)
78 if (f <= rg->to)
79 break;
80
81
82 if (f > rg->from)
83 f = rg->from;
84
85
86 nrg = rg;
87 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
88 if (&rg->link == head)
89 break;
90 if (rg->from > t)
91 break;
92
93
94
95
96 if (rg->to > t)
97 t = rg->to;
98 if (rg != nrg) {
99 list_del(&rg->link);
100 kfree(rg);
101 }
102 }
103 nrg->from = f;
104 nrg->to = t;
105 return 0;
106}
107
108static long region_chg(struct list_head *head, long f, long t)
109{
110 struct file_region *rg, *nrg;
111 long chg = 0;
112
113
114 list_for_each_entry(rg, head, link)
115 if (f <= rg->to)
116 break;
117
118
119
120
121 if (&rg->link == head || t < rg->from) {
122 nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
123 if (!nrg)
124 return -ENOMEM;
125 nrg->from = f;
126 nrg->to = f;
127 INIT_LIST_HEAD(&nrg->link);
128 list_add(&nrg->link, rg->link.prev);
129
130 return t - f;
131 }
132
133
134 if (f > rg->from)
135 f = rg->from;
136 chg = t - f;
137
138
139 list_for_each_entry(rg, rg->link.prev, link) {
140 if (&rg->link == head)
141 break;
142 if (rg->from > t)
143 return chg;
144
145
146
147
148 if (rg->to > t) {
149 chg += rg->to - t;
150 t = rg->to;
151 }
152 chg -= rg->to - rg->from;
153 }
154 return chg;
155}
156
157static long region_truncate(struct list_head *head, long end)
158{
159 struct file_region *rg, *trg;
160 long chg = 0;
161
162
163 list_for_each_entry(rg, head, link)
164 if (end <= rg->to)
165 break;
166 if (&rg->link == head)
167 return 0;
168
169
170 if (end > rg->from) {
171 chg = rg->to - end;
172 rg->to = end;
173 rg = list_entry(rg->link.next, typeof(*rg), link);
174 }
175
176
177 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
178 if (&rg->link == head)
179 break;
180 chg += rg->to - rg->from;
181 list_del(&rg->link);
182 kfree(rg);
183 }
184 return chg;
185}
186
187static long region_count(struct list_head *head, long f, long t)
188{
189 struct file_region *rg;
190 long chg = 0;
191
192
193 list_for_each_entry(rg, head, link) {
194 int seg_from;
195 int seg_to;
196
197 if (rg->to <= f)
198 continue;
199 if (rg->from >= t)
200 break;
201
202 seg_from = max(rg->from, f);
203 seg_to = min(rg->to, t);
204
205 chg += seg_to - seg_from;
206 }
207
208 return chg;
209}
210
211
212
213
214
215static pgoff_t vma_hugecache_offset(struct hstate *h,
216 struct vm_area_struct *vma, unsigned long address)
217{
218 return ((address - vma->vm_start) >> huge_page_shift(h)) +
219 (vma->vm_pgoff >> huge_page_order(h));
220}
221
222
223
224
225
226unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
227{
228 struct hstate *hstate;
229
230 if (!is_vm_hugetlb_page(vma))
231 return PAGE_SIZE;
232
233 hstate = hstate_vma(vma);
234
235 return 1UL << (hstate->order + PAGE_SHIFT);
236}
237EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
238
239
240
241
242
243
244
245#ifndef vma_mmu_pagesize
246unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
247{
248 return vma_kernel_pagesize(vma);
249}
250#endif
251
252
253
254
255
256
257#define HPAGE_RESV_OWNER (1UL << 0)
258#define HPAGE_RESV_UNMAPPED (1UL << 1)
259#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
260
261
262
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276
277
278
279
280static unsigned long get_vma_private_data(struct vm_area_struct *vma)
281{
282 return (unsigned long)vma->vm_private_data;
283}
284
285static void set_vma_private_data(struct vm_area_struct *vma,
286 unsigned long value)
287{
288 vma->vm_private_data = (void *)value;
289}
290
291struct resv_map {
292 struct kref refs;
293 struct list_head regions;
294};
295
296static struct resv_map *resv_map_alloc(void)
297{
298 struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
299 if (!resv_map)
300 return NULL;
301
302 kref_init(&resv_map->refs);
303 INIT_LIST_HEAD(&resv_map->regions);
304
305 return resv_map;
306}
307
308static void resv_map_release(struct kref *ref)
309{
310 struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
311
312
313 region_truncate(&resv_map->regions, 0);
314 kfree(resv_map);
315}
316
317static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
318{
319 VM_BUG_ON(!is_vm_hugetlb_page(vma));
320 if (!(vma->vm_flags & VM_MAYSHARE))
321 return (struct resv_map *)(get_vma_private_data(vma) &
322 ~HPAGE_RESV_MASK);
323 return NULL;
324}
325
326static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
327{
328 VM_BUG_ON(!is_vm_hugetlb_page(vma));
329 VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
330
331 set_vma_private_data(vma, (get_vma_private_data(vma) &
332 HPAGE_RESV_MASK) | (unsigned long)map);
333}
334
335static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
336{
337 VM_BUG_ON(!is_vm_hugetlb_page(vma));
338 VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
339
340 set_vma_private_data(vma, get_vma_private_data(vma) | flags);
341}
342
343static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
344{
345 VM_BUG_ON(!is_vm_hugetlb_page(vma));
346
347 return (get_vma_private_data(vma) & flag) != 0;
348}
349
350
351static void decrement_hugepage_resv_vma(struct hstate *h,
352 struct vm_area_struct *vma)
353{
354 if (vma->vm_flags & VM_NORESERVE)
355 return;
356
357 if (vma->vm_flags & VM_MAYSHARE) {
358
359 h->resv_huge_pages--;
360 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
361
362
363
364
365 h->resv_huge_pages--;
366 }
367}
368
369
370void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
371{
372 VM_BUG_ON(!is_vm_hugetlb_page(vma));
373 if (!(vma->vm_flags & VM_MAYSHARE))
374 vma->vm_private_data = (void *)0;
375}
376
377
378static int vma_has_reserves(struct vm_area_struct *vma)
379{
380 if (vma->vm_flags & VM_MAYSHARE)
381 return 1;
382 if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
383 return 1;
384 return 0;
385}
386
387static void clear_gigantic_page(struct page *page,
388 unsigned long addr, unsigned long sz)
389{
390 int i;
391 struct page *p = page;
392
393 might_sleep();
394 for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
395 cond_resched();
396 clear_user_highpage(p, addr + i * PAGE_SIZE);
397 }
398}
399static void clear_huge_page(struct page *page,
400 unsigned long addr, unsigned long sz)
401{
402 int i;
403
404 if (unlikely(sz > MAX_ORDER_NR_PAGES)) {
405 clear_gigantic_page(page, addr, sz);
406 return;
407 }
408
409 might_sleep();
410 for (i = 0; i < sz/PAGE_SIZE; i++) {
411 cond_resched();
412 clear_user_highpage(page + i, addr + i * PAGE_SIZE);
413 }
414}
415
416static void copy_gigantic_page(struct page *dst, struct page *src,
417 unsigned long addr, struct vm_area_struct *vma)
418{
419 int i;
420 struct hstate *h = hstate_vma(vma);
421 struct page *dst_base = dst;
422 struct page *src_base = src;
423 might_sleep();
424 for (i = 0; i < pages_per_huge_page(h); ) {
425 cond_resched();
426 copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
427
428 i++;
429 dst = mem_map_next(dst, dst_base, i);
430 src = mem_map_next(src, src_base, i);
431 }
432}
433static void copy_huge_page(struct page *dst, struct page *src,
434 unsigned long addr, struct vm_area_struct *vma)
435{
436 int i;
437 struct hstate *h = hstate_vma(vma);
438
439 if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
440 copy_gigantic_page(dst, src, addr, vma);
441 return;
442 }
443
444 might_sleep();
445 for (i = 0; i < pages_per_huge_page(h); i++) {
446 cond_resched();
447 copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
448 }
449}
450
451static void enqueue_huge_page(struct hstate *h, struct page *page)
452{
453 int nid = page_to_nid(page);
454 list_add(&page->lru, &h->hugepage_freelists[nid]);
455 h->free_huge_pages++;
456 h->free_huge_pages_node[nid]++;
457}
458
459static struct page *dequeue_huge_page_vma(struct hstate *h,
460 struct vm_area_struct *vma,
461 unsigned long address, int avoid_reserve)
462{
463 int nid;
464 struct page *page = NULL;
465 struct mempolicy *mpol;
466 nodemask_t *nodemask;
467 struct zonelist *zonelist = huge_zonelist(vma, address,
468 htlb_alloc_mask, &mpol, &nodemask);
469 struct zone *zone;
470 struct zoneref *z;
471
472
473
474
475
476
477 if (!vma_has_reserves(vma) &&
478 h->free_huge_pages - h->resv_huge_pages == 0)
479 return NULL;
480
481
482 if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
483 return NULL;
484
485 for_each_zone_zonelist_nodemask(zone, z, zonelist,
486 MAX_NR_ZONES - 1, nodemask) {
487 nid = zone_to_nid(zone);
488 if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
489 !list_empty(&h->hugepage_freelists[nid])) {
490 page = list_entry(h->hugepage_freelists[nid].next,
491 struct page, lru);
492 list_del(&page->lru);
493 h->free_huge_pages--;
494 h->free_huge_pages_node[nid]--;
495
496 if (!avoid_reserve)
497 decrement_hugepage_resv_vma(h, vma);
498
499 break;
500 }
501 }
502 mpol_cond_put(mpol);
503 return page;
504}
505
506static void update_and_free_page(struct hstate *h, struct page *page)
507{
508 int i;
509
510 VM_BUG_ON(h->order >= MAX_ORDER);
511
512 h->nr_huge_pages--;
513 h->nr_huge_pages_node[page_to_nid(page)]--;
514 for (i = 0; i < pages_per_huge_page(h); i++) {
515 page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
516 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
517 1 << PG_private | 1<< PG_writeback);
518 }
519 set_compound_page_dtor(page, NULL);
520 set_page_refcounted(page);
521 arch_release_hugepage(page);
522 __free_pages(page, huge_page_order(h));
523}
524
525struct hstate *size_to_hstate(unsigned long size)
526{
527 struct hstate *h;
528
529 for_each_hstate(h) {
530 if (huge_page_size(h) == size)
531 return h;
532 }
533 return NULL;
534}
535
536static void free_huge_page(struct page *page)
537{
538
539
540
541
542 struct hstate *h = page_hstate(page);
543 int nid = page_to_nid(page);
544 struct address_space *mapping;
545
546 mapping = (struct address_space *) page_private(page);
547 set_page_private(page, 0);
548 BUG_ON(page_count(page));
549 INIT_LIST_HEAD(&page->lru);
550
551 spin_lock(&hugetlb_lock);
552 if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
553 update_and_free_page(h, page);
554 h->surplus_huge_pages--;
555 h->surplus_huge_pages_node[nid]--;
556 } else {
557 enqueue_huge_page(h, page);
558 }
559 spin_unlock(&hugetlb_lock);
560 if (mapping)
561 hugetlb_put_quota(mapping, 1);
562}
563
564static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
565{
566 set_compound_page_dtor(page, free_huge_page);
567 spin_lock(&hugetlb_lock);
568 h->nr_huge_pages++;
569 h->nr_huge_pages_node[nid]++;
570 spin_unlock(&hugetlb_lock);
571 put_page(page);
572}
573
574static void prep_compound_gigantic_page(struct page *page, unsigned long order)
575{
576 int i;
577 int nr_pages = 1 << order;
578 struct page *p = page + 1;
579
580
581 set_compound_order(page, order);
582 __SetPageHead(page);
583 for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
584 __SetPageTail(p);
585 p->first_page = page;
586 }
587}
588
589int PageHuge(struct page *page)
590{
591 compound_page_dtor *dtor;
592
593 if (!PageCompound(page))
594 return 0;
595
596 page = compound_head(page);
597 dtor = get_compound_page_dtor(page);
598
599 return dtor == free_huge_page;
600}
601
602static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
603{
604 struct page *page;
605
606 if (h->order >= MAX_ORDER)
607 return NULL;
608
609 page = alloc_pages_exact_node(nid,
610 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
611 __GFP_REPEAT|__GFP_NOWARN,
612 huge_page_order(h));
613 if (page) {
614 if (arch_prepare_hugepage(page)) {
615 __free_pages(page, huge_page_order(h));
616 return NULL;
617 }
618 prep_new_huge_page(h, page, nid);
619 }
620
621 return page;
622}
623
624
625
626
627
628
629
630
631
632
633
634
635static int hstate_next_node_to_alloc(struct hstate *h)
636{
637 int next_nid;
638 next_nid = next_node(h->next_nid_to_alloc, node_online_map);
639 if (next_nid == MAX_NUMNODES)
640 next_nid = first_node(node_online_map);
641 h->next_nid_to_alloc = next_nid;
642 return next_nid;
643}
644
645static int alloc_fresh_huge_page(struct hstate *h)
646{
647 struct page *page;
648 int start_nid;
649 int next_nid;
650 int ret = 0;
651
652 start_nid = h->next_nid_to_alloc;
653 next_nid = start_nid;
654
655 do {
656 page = alloc_fresh_huge_page_node(h, next_nid);
657 if (page)
658 ret = 1;
659 next_nid = hstate_next_node_to_alloc(h);
660 } while (!page && next_nid != start_nid);
661
662 if (ret)
663 count_vm_event(HTLB_BUDDY_PGALLOC);
664 else
665 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
666
667 return ret;
668}
669
670
671
672
673
674static int hstate_next_node_to_free(struct hstate *h)
675{
676 int next_nid;
677 next_nid = next_node(h->next_nid_to_free, node_online_map);
678 if (next_nid == MAX_NUMNODES)
679 next_nid = first_node(node_online_map);
680 h->next_nid_to_free = next_nid;
681 return next_nid;
682}
683
684
685
686
687
688
689
690static int free_pool_huge_page(struct hstate *h, bool acct_surplus)
691{
692 int start_nid;
693 int next_nid;
694 int ret = 0;
695
696 start_nid = h->next_nid_to_free;
697 next_nid = start_nid;
698
699 do {
700
701
702
703
704 if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
705 !list_empty(&h->hugepage_freelists[next_nid])) {
706 struct page *page =
707 list_entry(h->hugepage_freelists[next_nid].next,
708 struct page, lru);
709 list_del(&page->lru);
710 h->free_huge_pages--;
711 h->free_huge_pages_node[next_nid]--;
712 if (acct_surplus) {
713 h->surplus_huge_pages--;
714 h->surplus_huge_pages_node[next_nid]--;
715 }
716 update_and_free_page(h, page);
717 ret = 1;
718 }
719 next_nid = hstate_next_node_to_free(h);
720 } while (!ret && next_nid != start_nid);
721
722 return ret;
723}
724
725static struct page *alloc_buddy_huge_page(struct hstate *h,
726 struct vm_area_struct *vma, unsigned long address)
727{
728 struct page *page;
729 unsigned int nid;
730
731 if (h->order >= MAX_ORDER)
732 return NULL;
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757 spin_lock(&hugetlb_lock);
758 if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
759 spin_unlock(&hugetlb_lock);
760 return NULL;
761 } else {
762 h->nr_huge_pages++;
763 h->surplus_huge_pages++;
764 }
765 spin_unlock(&hugetlb_lock);
766
767 page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
768 __GFP_REPEAT|__GFP_NOWARN,
769 huge_page_order(h));
770
771 if (page && arch_prepare_hugepage(page)) {
772 __free_pages(page, huge_page_order(h));
773 return NULL;
774 }
775
776 spin_lock(&hugetlb_lock);
777 if (page) {
778
779
780
781
782 put_page_testzero(page);
783 VM_BUG_ON(page_count(page));
784 nid = page_to_nid(page);
785 set_compound_page_dtor(page, free_huge_page);
786
787
788
789 h->nr_huge_pages_node[nid]++;
790 h->surplus_huge_pages_node[nid]++;
791 __count_vm_event(HTLB_BUDDY_PGALLOC);
792 } else {
793 h->nr_huge_pages--;
794 h->surplus_huge_pages--;
795 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
796 }
797 spin_unlock(&hugetlb_lock);
798
799 return page;
800}
801
802
803
804
805
806static int gather_surplus_pages(struct hstate *h, int delta)
807{
808 struct list_head surplus_list;
809 struct page *page, *tmp;
810 int ret, i;
811 int needed, allocated;
812
813 needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
814 if (needed <= 0) {
815 h->resv_huge_pages += delta;
816 return 0;
817 }
818
819 allocated = 0;
820 INIT_LIST_HEAD(&surplus_list);
821
822 ret = -ENOMEM;
823retry:
824 spin_unlock(&hugetlb_lock);
825 for (i = 0; i < needed; i++) {
826 page = alloc_buddy_huge_page(h, NULL, 0);
827 if (!page) {
828
829
830
831
832
833 spin_lock(&hugetlb_lock);
834 needed = 0;
835 goto free;
836 }
837
838 list_add(&page->lru, &surplus_list);
839 }
840 allocated += needed;
841
842
843
844
845
846 spin_lock(&hugetlb_lock);
847 needed = (h->resv_huge_pages + delta) -
848 (h->free_huge_pages + allocated);
849 if (needed > 0)
850 goto retry;
851
852
853
854
855
856
857
858
859
860 needed += allocated;
861 h->resv_huge_pages += delta;
862 ret = 0;
863free:
864
865 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
866 if ((--needed) < 0)
867 break;
868 list_del(&page->lru);
869 enqueue_huge_page(h, page);
870 }
871
872
873 if (!list_empty(&surplus_list)) {
874 spin_unlock(&hugetlb_lock);
875 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
876 list_del(&page->lru);
877
878
879
880
881
882
883
884 free_huge_page(page);
885 }
886 spin_lock(&hugetlb_lock);
887 }
888
889 return ret;
890}
891
892
893
894
895
896
897
898static void return_unused_surplus_pages(struct hstate *h,
899 unsigned long unused_resv_pages)
900{
901 unsigned long nr_pages;
902
903
904 h->resv_huge_pages -= unused_resv_pages;
905
906
907 if (h->order >= MAX_ORDER)
908 return;
909
910 nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
911
912
913
914
915
916
917
918
919
920 while (nr_pages--) {
921 if (!free_pool_huge_page(h, 1))
922 break;
923 }
924}
925
926
927
928
929
930
931
932
933
934
935static long vma_needs_reservation(struct hstate *h,
936 struct vm_area_struct *vma, unsigned long addr)
937{
938 struct address_space *mapping = vma->vm_file->f_mapping;
939 struct inode *inode = mapping->host;
940
941 if (vma->vm_flags & VM_MAYSHARE) {
942 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
943 return region_chg(&inode->i_mapping->private_list,
944 idx, idx + 1);
945
946 } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
947 return 1;
948
949 } else {
950 long err;
951 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
952 struct resv_map *reservations = vma_resv_map(vma);
953
954 err = region_chg(&reservations->regions, idx, idx + 1);
955 if (err < 0)
956 return err;
957 return 0;
958 }
959}
960static void vma_commit_reservation(struct hstate *h,
961 struct vm_area_struct *vma, unsigned long addr)
962{
963 struct address_space *mapping = vma->vm_file->f_mapping;
964 struct inode *inode = mapping->host;
965
966 if (vma->vm_flags & VM_MAYSHARE) {
967 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
968 region_add(&inode->i_mapping->private_list, idx, idx + 1);
969
970 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
971 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
972 struct resv_map *reservations = vma_resv_map(vma);
973
974
975 region_add(&reservations->regions, idx, idx + 1);
976 }
977}
978
979static struct page *alloc_huge_page(struct vm_area_struct *vma,
980 unsigned long addr, int avoid_reserve)
981{
982 struct hstate *h = hstate_vma(vma);
983 struct page *page;
984 struct address_space *mapping = vma->vm_file->f_mapping;
985 struct inode *inode = mapping->host;
986 long chg;
987
988
989
990
991
992
993
994
995 chg = vma_needs_reservation(h, vma, addr);
996 if (chg < 0)
997 return ERR_PTR(chg);
998 if (chg)
999 if (hugetlb_get_quota(inode->i_mapping, chg))
1000 return ERR_PTR(-ENOSPC);
1001
1002 spin_lock(&hugetlb_lock);
1003 page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
1004 spin_unlock(&hugetlb_lock);
1005
1006 if (!page) {
1007 page = alloc_buddy_huge_page(h, vma, addr);
1008 if (!page) {
1009 hugetlb_put_quota(inode->i_mapping, chg);
1010 return ERR_PTR(-VM_FAULT_OOM);
1011 }
1012 }
1013
1014 set_page_refcounted(page);
1015 set_page_private(page, (unsigned long) mapping);
1016
1017 vma_commit_reservation(h, vma, addr);
1018
1019 return page;
1020}
1021
1022int __weak alloc_bootmem_huge_page(struct hstate *h)
1023{
1024 struct huge_bootmem_page *m;
1025 int nr_nodes = nodes_weight(node_online_map);
1026
1027 while (nr_nodes) {
1028 void *addr;
1029
1030 addr = __alloc_bootmem_node_nopanic(
1031 NODE_DATA(h->next_nid_to_alloc),
1032 huge_page_size(h), huge_page_size(h), 0);
1033
1034 hstate_next_node_to_alloc(h);
1035 if (addr) {
1036
1037
1038
1039
1040
1041 m = addr;
1042 goto found;
1043 }
1044 nr_nodes--;
1045 }
1046 return 0;
1047
1048found:
1049 BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
1050
1051 list_add(&m->list, &huge_boot_pages);
1052 m->hstate = h;
1053 return 1;
1054}
1055
1056static void prep_compound_huge_page(struct page *page, int order)
1057{
1058 if (unlikely(order > (MAX_ORDER - 1)))
1059 prep_compound_gigantic_page(page, order);
1060 else
1061 prep_compound_page(page, order);
1062}
1063
1064
1065static void __init gather_bootmem_prealloc(void)
1066{
1067 struct huge_bootmem_page *m;
1068
1069 list_for_each_entry(m, &huge_boot_pages, list) {
1070 struct page *page = virt_to_page(m);
1071 struct hstate *h = m->hstate;
1072 __ClearPageReserved(page);
1073 WARN_ON(page_count(page) != 1);
1074 prep_compound_huge_page(page, h->order);
1075 prep_new_huge_page(h, page, page_to_nid(page));
1076 }
1077}
1078
1079static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
1080{
1081 unsigned long i;
1082
1083 for (i = 0; i < h->max_huge_pages; ++i) {
1084 if (h->order >= MAX_ORDER) {
1085 if (!alloc_bootmem_huge_page(h))
1086 break;
1087 } else if (!alloc_fresh_huge_page(h))
1088 break;
1089 }
1090 h->max_huge_pages = i;
1091}
1092
1093static void __init hugetlb_init_hstates(void)
1094{
1095 struct hstate *h;
1096
1097 for_each_hstate(h) {
1098
1099 if (h->order < MAX_ORDER)
1100 hugetlb_hstate_alloc_pages(h);
1101 }
1102}
1103
1104static char * __init memfmt(char *buf, unsigned long n)
1105{
1106 if (n >= (1UL << 30))
1107 sprintf(buf, "%lu GB", n >> 30);
1108 else if (n >= (1UL << 20))
1109 sprintf(buf, "%lu MB", n >> 20);
1110 else
1111 sprintf(buf, "%lu KB", n >> 10);
1112 return buf;
1113}
1114
1115static void __init report_hugepages(void)
1116{
1117 struct hstate *h;
1118
1119 for_each_hstate(h) {
1120 char buf[32];
1121 printk(KERN_INFO "HugeTLB registered %s page size, "
1122 "pre-allocated %ld pages\n",
1123 memfmt(buf, huge_page_size(h)),
1124 h->free_huge_pages);
1125 }
1126}
1127
1128#ifdef CONFIG_HIGHMEM
1129static void try_to_free_low(struct hstate *h, unsigned long count)
1130{
1131 int i;
1132
1133 if (h->order >= MAX_ORDER)
1134 return;
1135
1136 for (i = 0; i < MAX_NUMNODES; ++i) {
1137 struct page *page, *next;
1138 struct list_head *freel = &h->hugepage_freelists[i];
1139 list_for_each_entry_safe(page, next, freel, lru) {
1140 if (count >= h->nr_huge_pages)
1141 return;
1142 if (PageHighMem(page))
1143 continue;
1144 list_del(&page->lru);
1145 update_and_free_page(h, page);
1146 h->free_huge_pages--;
1147 h->free_huge_pages_node[page_to_nid(page)]--;
1148 }
1149 }
1150}
1151#else
1152static inline void try_to_free_low(struct hstate *h, unsigned long count)
1153{
1154}
1155#endif
1156
1157
1158
1159
1160
1161
1162static int adjust_pool_surplus(struct hstate *h, int delta)
1163{
1164 int start_nid, next_nid;
1165 int ret = 0;
1166
1167 VM_BUG_ON(delta != -1 && delta != 1);
1168
1169 if (delta < 0)
1170 start_nid = h->next_nid_to_alloc;
1171 else
1172 start_nid = h->next_nid_to_free;
1173 next_nid = start_nid;
1174
1175 do {
1176 int nid = next_nid;
1177 if (delta < 0) {
1178 next_nid = hstate_next_node_to_alloc(h);
1179
1180
1181
1182 if (!h->surplus_huge_pages_node[nid])
1183 continue;
1184 }
1185 if (delta > 0) {
1186 next_nid = hstate_next_node_to_free(h);
1187
1188
1189
1190 if (h->surplus_huge_pages_node[nid] >=
1191 h->nr_huge_pages_node[nid])
1192 continue;
1193 }
1194
1195 h->surplus_huge_pages += delta;
1196 h->surplus_huge_pages_node[nid] += delta;
1197 ret = 1;
1198 break;
1199 } while (next_nid != start_nid);
1200
1201 return ret;
1202}
1203
1204#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
1205static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
1206{
1207 unsigned long min_count, ret;
1208
1209 if (h->order >= MAX_ORDER)
1210 return h->max_huge_pages;
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223 spin_lock(&hugetlb_lock);
1224 while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
1225 if (!adjust_pool_surplus(h, -1))
1226 break;
1227 }
1228
1229 while (count > persistent_huge_pages(h)) {
1230
1231
1232
1233
1234
1235 spin_unlock(&hugetlb_lock);
1236 ret = alloc_fresh_huge_page(h);
1237 spin_lock(&hugetlb_lock);
1238 if (!ret)
1239 goto out;
1240
1241 }
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258 min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
1259 min_count = max(count, min_count);
1260 try_to_free_low(h, min_count);
1261 while (min_count < persistent_huge_pages(h)) {
1262 if (!free_pool_huge_page(h, 0))
1263 break;
1264 }
1265 while (count < persistent_huge_pages(h)) {
1266 if (!adjust_pool_surplus(h, 1))
1267 break;
1268 }
1269out:
1270 ret = persistent_huge_pages(h);
1271 spin_unlock(&hugetlb_lock);
1272 return ret;
1273}
1274
1275#define HSTATE_ATTR_RO(_name) \
1276 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1277
1278#define HSTATE_ATTR(_name) \
1279 static struct kobj_attribute _name##_attr = \
1280 __ATTR(_name, 0644, _name##_show, _name##_store)
1281
1282static struct kobject *hugepages_kobj;
1283static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1284
1285static struct hstate *kobj_to_hstate(struct kobject *kobj)
1286{
1287 int i;
1288 for (i = 0; i < HUGE_MAX_HSTATE; i++)
1289 if (hstate_kobjs[i] == kobj)
1290 return &hstates[i];
1291 BUG();
1292 return NULL;
1293}
1294
1295static ssize_t nr_hugepages_show(struct kobject *kobj,
1296 struct kobj_attribute *attr, char *buf)
1297{
1298 struct hstate *h = kobj_to_hstate(kobj);
1299 return sprintf(buf, "%lu\n", h->nr_huge_pages);
1300}
1301static ssize_t nr_hugepages_store(struct kobject *kobj,
1302 struct kobj_attribute *attr, const char *buf, size_t count)
1303{
1304 int err;
1305 unsigned long input;
1306 struct hstate *h = kobj_to_hstate(kobj);
1307
1308 err = strict_strtoul(buf, 10, &input);
1309 if (err)
1310 return 0;
1311
1312 h->max_huge_pages = set_max_huge_pages(h, input);
1313
1314 return count;
1315}
1316HSTATE_ATTR(nr_hugepages);
1317
1318static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
1319 struct kobj_attribute *attr, char *buf)
1320{
1321 struct hstate *h = kobj_to_hstate(kobj);
1322 return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
1323}
1324static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
1325 struct kobj_attribute *attr, const char *buf, size_t count)
1326{
1327 int err;
1328 unsigned long input;
1329 struct hstate *h = kobj_to_hstate(kobj);
1330
1331 err = strict_strtoul(buf, 10, &input);
1332 if (err)
1333 return 0;
1334
1335 spin_lock(&hugetlb_lock);
1336 h->nr_overcommit_huge_pages = input;
1337 spin_unlock(&hugetlb_lock);
1338
1339 return count;
1340}
1341HSTATE_ATTR(nr_overcommit_hugepages);
1342
1343static ssize_t free_hugepages_show(struct kobject *kobj,
1344 struct kobj_attribute *attr, char *buf)
1345{
1346 struct hstate *h = kobj_to_hstate(kobj);
1347 return sprintf(buf, "%lu\n", h->free_huge_pages);
1348}
1349HSTATE_ATTR_RO(free_hugepages);
1350
1351static ssize_t resv_hugepages_show(struct kobject *kobj,
1352 struct kobj_attribute *attr, char *buf)
1353{
1354 struct hstate *h = kobj_to_hstate(kobj);
1355 return sprintf(buf, "%lu\n", h->resv_huge_pages);
1356}
1357HSTATE_ATTR_RO(resv_hugepages);
1358
1359static ssize_t surplus_hugepages_show(struct kobject *kobj,
1360 struct kobj_attribute *attr, char *buf)
1361{
1362 struct hstate *h = kobj_to_hstate(kobj);
1363 return sprintf(buf, "%lu\n", h->surplus_huge_pages);
1364}
1365HSTATE_ATTR_RO(surplus_hugepages);
1366
1367static struct attribute *hstate_attrs[] = {
1368 &nr_hugepages_attr.attr,
1369 &nr_overcommit_hugepages_attr.attr,
1370 &free_hugepages_attr.attr,
1371 &resv_hugepages_attr.attr,
1372 &surplus_hugepages_attr.attr,
1373 NULL,
1374};
1375
1376static struct attribute_group hstate_attr_group = {
1377 .attrs = hstate_attrs,
1378};
1379
1380static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
1381{
1382 int retval;
1383
1384 hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
1385 hugepages_kobj);
1386 if (!hstate_kobjs[h - hstates])
1387 return -ENOMEM;
1388
1389 retval = sysfs_create_group(hstate_kobjs[h - hstates],
1390 &hstate_attr_group);
1391 if (retval)
1392 kobject_put(hstate_kobjs[h - hstates]);
1393
1394 return retval;
1395}
1396
1397static void __init hugetlb_sysfs_init(void)
1398{
1399 struct hstate *h;
1400 int err;
1401
1402 hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
1403 if (!hugepages_kobj)
1404 return;
1405
1406 for_each_hstate(h) {
1407 err = hugetlb_sysfs_add_hstate(h);
1408 if (err)
1409 printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
1410 h->name);
1411 }
1412}
1413
1414static void __exit hugetlb_exit(void)
1415{
1416 struct hstate *h;
1417
1418 for_each_hstate(h) {
1419 kobject_put(hstate_kobjs[h - hstates]);
1420 }
1421
1422 kobject_put(hugepages_kobj);
1423}
1424module_exit(hugetlb_exit);
1425
1426static int __init hugetlb_init(void)
1427{
1428
1429
1430
1431
1432 if (HPAGE_SHIFT == 0)
1433 return 0;
1434
1435 if (!size_to_hstate(default_hstate_size)) {
1436 default_hstate_size = HPAGE_SIZE;
1437 if (!size_to_hstate(default_hstate_size))
1438 hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
1439 }
1440 default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
1441 if (default_hstate_max_huge_pages)
1442 default_hstate.max_huge_pages = default_hstate_max_huge_pages;
1443
1444 hugetlb_init_hstates();
1445
1446 gather_bootmem_prealloc();
1447
1448 report_hugepages();
1449
1450 hugetlb_sysfs_init();
1451
1452 return 0;
1453}
1454module_init(hugetlb_init);
1455
1456
1457void __init hugetlb_add_hstate(unsigned order)
1458{
1459 struct hstate *h;
1460 unsigned long i;
1461
1462 if (size_to_hstate(PAGE_SIZE << order)) {
1463 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
1464 return;
1465 }
1466 BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
1467 BUG_ON(order == 0);
1468 h = &hstates[max_hstate++];
1469 h->order = order;
1470 h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
1471 h->nr_huge_pages = 0;
1472 h->free_huge_pages = 0;
1473 for (i = 0; i < MAX_NUMNODES; ++i)
1474 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
1475 h->next_nid_to_alloc = first_node(node_online_map);
1476 h->next_nid_to_free = first_node(node_online_map);
1477 snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
1478 huge_page_size(h)/1024);
1479
1480 parsed_hstate = h;
1481}
1482
1483static int __init hugetlb_nrpages_setup(char *s)
1484{
1485 unsigned long *mhp;
1486 static unsigned long *last_mhp;
1487
1488
1489
1490
1491
1492 if (!max_hstate)
1493 mhp = &default_hstate_max_huge_pages;
1494 else
1495 mhp = &parsed_hstate->max_huge_pages;
1496
1497 if (mhp == last_mhp) {
1498 printk(KERN_WARNING "hugepages= specified twice without "
1499 "interleaving hugepagesz=, ignoring\n");
1500 return 1;
1501 }
1502
1503 if (sscanf(s, "%lu", mhp) <= 0)
1504 *mhp = 0;
1505
1506
1507
1508
1509
1510
1511 if (max_hstate && parsed_hstate->order >= MAX_ORDER)
1512 hugetlb_hstate_alloc_pages(parsed_hstate);
1513
1514 last_mhp = mhp;
1515
1516 return 1;
1517}
1518__setup("hugepages=", hugetlb_nrpages_setup);
1519
1520static int __init hugetlb_default_setup(char *s)
1521{
1522 default_hstate_size = memparse(s, &s);
1523 return 1;
1524}
1525__setup("default_hugepagesz=", hugetlb_default_setup);
1526
1527static unsigned int cpuset_mems_nr(unsigned int *array)
1528{
1529 int node;
1530 unsigned int nr = 0;
1531
1532 for_each_node_mask(node, cpuset_current_mems_allowed)
1533 nr += array[node];
1534
1535 return nr;
1536}
1537
1538#ifdef CONFIG_SYSCTL
1539int hugetlb_sysctl_handler(struct ctl_table *table, int write,
1540 void __user *buffer,
1541 size_t *length, loff_t *ppos)
1542{
1543 struct hstate *h = &default_hstate;
1544 unsigned long tmp;
1545
1546 if (!write)
1547 tmp = h->max_huge_pages;
1548
1549 table->data = &tmp;
1550 table->maxlen = sizeof(unsigned long);
1551 proc_doulongvec_minmax(table, write, buffer, length, ppos);
1552
1553 if (write)
1554 h->max_huge_pages = set_max_huge_pages(h, tmp);
1555
1556 return 0;
1557}
1558
1559int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
1560 void __user *buffer,
1561 size_t *length, loff_t *ppos)
1562{
1563 proc_dointvec(table, write, buffer, length, ppos);
1564 if (hugepages_treat_as_movable)
1565 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
1566 else
1567 htlb_alloc_mask = GFP_HIGHUSER;
1568 return 0;
1569}
1570
1571int hugetlb_overcommit_handler(struct ctl_table *table, int write,
1572 void __user *buffer,
1573 size_t *length, loff_t *ppos)
1574{
1575 struct hstate *h = &default_hstate;
1576 unsigned long tmp;
1577
1578 if (!write)
1579 tmp = h->nr_overcommit_huge_pages;
1580
1581 table->data = &tmp;
1582 table->maxlen = sizeof(unsigned long);
1583 proc_doulongvec_minmax(table, write, buffer, length, ppos);
1584
1585 if (write) {
1586 spin_lock(&hugetlb_lock);
1587 h->nr_overcommit_huge_pages = tmp;
1588 spin_unlock(&hugetlb_lock);
1589 }
1590
1591 return 0;
1592}
1593
1594#endif
1595
1596void hugetlb_report_meminfo(struct seq_file *m)
1597{
1598 struct hstate *h = &default_hstate;
1599 seq_printf(m,
1600 "HugePages_Total: %5lu\n"
1601 "HugePages_Free: %5lu\n"
1602 "HugePages_Rsvd: %5lu\n"
1603 "HugePages_Surp: %5lu\n"
1604 "Hugepagesize: %8lu kB\n",
1605 h->nr_huge_pages,
1606 h->free_huge_pages,
1607 h->resv_huge_pages,
1608 h->surplus_huge_pages,
1609 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
1610}
1611
1612int hugetlb_report_node_meminfo(int nid, char *buf)
1613{
1614 struct hstate *h = &default_hstate;
1615 return sprintf(buf,
1616 "Node %d HugePages_Total: %5u\n"
1617 "Node %d HugePages_Free: %5u\n"
1618 "Node %d HugePages_Surp: %5u\n",
1619 nid, h->nr_huge_pages_node[nid],
1620 nid, h->free_huge_pages_node[nid],
1621 nid, h->surplus_huge_pages_node[nid]);
1622}
1623
1624
1625unsigned long hugetlb_total_pages(void)
1626{
1627 struct hstate *h = &default_hstate;
1628 return h->nr_huge_pages * pages_per_huge_page(h);
1629}
1630
1631static int hugetlb_acct_memory(struct hstate *h, long delta)
1632{
1633 int ret = -ENOMEM;
1634
1635 spin_lock(&hugetlb_lock);
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653 if (delta > 0) {
1654 if (gather_surplus_pages(h, delta) < 0)
1655 goto out;
1656
1657 if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
1658 return_unused_surplus_pages(h, delta);
1659 goto out;
1660 }
1661 }
1662
1663 ret = 0;
1664 if (delta < 0)
1665 return_unused_surplus_pages(h, (unsigned long) -delta);
1666
1667out:
1668 spin_unlock(&hugetlb_lock);
1669 return ret;
1670}
1671
1672static void hugetlb_vm_op_open(struct vm_area_struct *vma)
1673{
1674 struct resv_map *reservations = vma_resv_map(vma);
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684 if (reservations)
1685 kref_get(&reservations->refs);
1686}
1687
1688static void hugetlb_vm_op_close(struct vm_area_struct *vma)
1689{
1690 struct hstate *h = hstate_vma(vma);
1691 struct resv_map *reservations = vma_resv_map(vma);
1692 unsigned long reserve;
1693 unsigned long start;
1694 unsigned long end;
1695
1696 if (reservations) {
1697 start = vma_hugecache_offset(h, vma, vma->vm_start);
1698 end = vma_hugecache_offset(h, vma, vma->vm_end);
1699
1700 reserve = (end - start) -
1701 region_count(&reservations->regions, start, end);
1702
1703 kref_put(&reservations->refs, resv_map_release);
1704
1705 if (reserve) {
1706 hugetlb_acct_memory(h, -reserve);
1707 hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
1708 }
1709 }
1710}
1711
1712
1713
1714
1715
1716
1717
1718static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1719{
1720 BUG();
1721 return 0;
1722}
1723
1724const struct vm_operations_struct hugetlb_vm_ops = {
1725 .fault = hugetlb_vm_op_fault,
1726 .open = hugetlb_vm_op_open,
1727 .close = hugetlb_vm_op_close,
1728};
1729
1730static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
1731 int writable)
1732{
1733 pte_t entry;
1734
1735 if (writable) {
1736 entry =
1737 pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
1738 } else {
1739 entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
1740 }
1741 entry = pte_mkyoung(entry);
1742 entry = pte_mkhuge(entry);
1743
1744 return entry;
1745}
1746
1747static void set_huge_ptep_writable(struct vm_area_struct *vma,
1748 unsigned long address, pte_t *ptep)
1749{
1750 pte_t entry;
1751
1752 entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
1753 if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
1754 update_mmu_cache(vma, address, entry);
1755 }
1756}
1757
1758
1759int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
1760 struct vm_area_struct *vma)
1761{
1762 pte_t *src_pte, *dst_pte, entry;
1763 struct page *ptepage;
1764 unsigned long addr;
1765 int cow;
1766 struct hstate *h = hstate_vma(vma);
1767 unsigned long sz = huge_page_size(h);
1768
1769 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
1770
1771 for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
1772 src_pte = huge_pte_offset(src, addr);
1773 if (!src_pte)
1774 continue;
1775 dst_pte = huge_pte_alloc(dst, addr, sz);
1776 if (!dst_pte)
1777 goto nomem;
1778
1779
1780 if (dst_pte == src_pte)
1781 continue;
1782
1783 spin_lock(&dst->page_table_lock);
1784 spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
1785 if (!huge_pte_none(huge_ptep_get(src_pte))) {
1786 if (cow)
1787 huge_ptep_set_wrprotect(src, addr, src_pte);
1788 entry = huge_ptep_get(src_pte);
1789 ptepage = pte_page(entry);
1790 get_page(ptepage);
1791 set_huge_pte_at(dst, addr, dst_pte, entry);
1792 }
1793 spin_unlock(&src->page_table_lock);
1794 spin_unlock(&dst->page_table_lock);
1795 }
1796 return 0;
1797
1798nomem:
1799 return -ENOMEM;
1800}
1801
1802void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
1803 unsigned long end, struct page *ref_page)
1804{
1805 struct mm_struct *mm = vma->vm_mm;
1806 unsigned long address;
1807 pte_t *ptep;
1808 pte_t pte;
1809 struct page *page;
1810 struct page *tmp;
1811 struct hstate *h = hstate_vma(vma);
1812 unsigned long sz = huge_page_size(h);
1813
1814
1815
1816
1817
1818
1819 LIST_HEAD(page_list);
1820
1821 WARN_ON(!is_vm_hugetlb_page(vma));
1822 BUG_ON(start & ~huge_page_mask(h));
1823 BUG_ON(end & ~huge_page_mask(h));
1824
1825 mmu_notifier_invalidate_range_start(mm, start, end);
1826 spin_lock(&mm->page_table_lock);
1827 for (address = start; address < end; address += sz) {
1828 ptep = huge_pte_offset(mm, address);
1829 if (!ptep)
1830 continue;
1831
1832 if (huge_pmd_unshare(mm, &address, ptep))
1833 continue;
1834
1835
1836
1837
1838
1839
1840 if (ref_page) {
1841 pte = huge_ptep_get(ptep);
1842 if (huge_pte_none(pte))
1843 continue;
1844 page = pte_page(pte);
1845 if (page != ref_page)
1846 continue;
1847
1848
1849
1850
1851
1852
1853 set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
1854 }
1855
1856 pte = huge_ptep_get_and_clear(mm, address, ptep);
1857 if (huge_pte_none(pte))
1858 continue;
1859
1860 page = pte_page(pte);
1861 if (pte_dirty(pte))
1862 set_page_dirty(page);
1863 list_add(&page->lru, &page_list);
1864 }
1865 spin_unlock(&mm->page_table_lock);
1866 flush_tlb_range(vma, start, end);
1867 mmu_notifier_invalidate_range_end(mm, start, end);
1868 list_for_each_entry_safe(page, tmp, &page_list, lru) {
1869 list_del(&page->lru);
1870 put_page(page);
1871 }
1872}
1873
1874void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
1875 unsigned long end, struct page *ref_page)
1876{
1877 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
1878 __unmap_hugepage_range(vma, start, end, ref_page);
1879 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
1880}
1881
1882
1883
1884
1885
1886
1887
1888static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
1889 struct page *page, unsigned long address)
1890{
1891 struct hstate *h = hstate_vma(vma);
1892 struct vm_area_struct *iter_vma;
1893 struct address_space *mapping;
1894 struct prio_tree_iter iter;
1895 pgoff_t pgoff;
1896
1897
1898
1899
1900
1901 address = address & huge_page_mask(h);
1902 pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
1903 + (vma->vm_pgoff >> PAGE_SHIFT);
1904 mapping = (struct address_space *)page_private(page);
1905
1906 vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
1907
1908 if (iter_vma == vma)
1909 continue;
1910
1911
1912
1913
1914
1915
1916
1917
1918 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
1919 unmap_hugepage_range(iter_vma,
1920 address, address + huge_page_size(h),
1921 page);
1922 }
1923
1924 return 1;
1925}
1926
1927static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
1928 unsigned long address, pte_t *ptep, pte_t pte,
1929 struct page *pagecache_page)
1930{
1931 struct hstate *h = hstate_vma(vma);
1932 struct page *old_page, *new_page;
1933 int avoidcopy;
1934 int outside_reserve = 0;
1935
1936 old_page = pte_page(pte);
1937
1938retry_avoidcopy:
1939
1940
1941 avoidcopy = (page_count(old_page) == 1);
1942 if (avoidcopy) {
1943 set_huge_ptep_writable(vma, address, ptep);
1944 return 0;
1945 }
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956 if (!(vma->vm_flags & VM_MAYSHARE) &&
1957 is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
1958 old_page != pagecache_page)
1959 outside_reserve = 1;
1960
1961 page_cache_get(old_page);
1962 new_page = alloc_huge_page(vma, address, outside_reserve);
1963
1964 if (IS_ERR(new_page)) {
1965 page_cache_release(old_page);
1966
1967
1968
1969
1970
1971
1972
1973
1974 if (outside_reserve) {
1975 BUG_ON(huge_pte_none(pte));
1976 if (unmap_ref_private(mm, vma, old_page, address)) {
1977 BUG_ON(page_count(old_page) != 1);
1978 BUG_ON(huge_pte_none(pte));
1979 goto retry_avoidcopy;
1980 }
1981 WARN_ON_ONCE(1);
1982 }
1983
1984 return -PTR_ERR(new_page);
1985 }
1986
1987 spin_unlock(&mm->page_table_lock);
1988 copy_huge_page(new_page, old_page, address, vma);
1989 __SetPageUptodate(new_page);
1990 spin_lock(&mm->page_table_lock);
1991
1992 ptep = huge_pte_offset(mm, address & huge_page_mask(h));
1993 if (likely(pte_same(huge_ptep_get(ptep), pte))) {
1994
1995 huge_ptep_clear_flush(vma, address, ptep);
1996 set_huge_pte_at(mm, address, ptep,
1997 make_huge_pte(vma, new_page, 1));
1998
1999 new_page = old_page;
2000 }
2001 page_cache_release(new_page);
2002 page_cache_release(old_page);
2003 return 0;
2004}
2005
2006
2007static struct page *hugetlbfs_pagecache_page(struct hstate *h,
2008 struct vm_area_struct *vma, unsigned long address)
2009{
2010 struct address_space *mapping;
2011 pgoff_t idx;
2012
2013 mapping = vma->vm_file->f_mapping;
2014 idx = vma_hugecache_offset(h, vma, address);
2015
2016 return find_lock_page(mapping, idx);
2017}
2018
2019
2020
2021
2022
2023static bool hugetlbfs_pagecache_present(struct hstate *h,
2024 struct vm_area_struct *vma, unsigned long address)
2025{
2026 struct address_space *mapping;
2027 pgoff_t idx;
2028 struct page *page;
2029
2030 mapping = vma->vm_file->f_mapping;
2031 idx = vma_hugecache_offset(h, vma, address);
2032
2033 page = find_get_page(mapping, idx);
2034 if (page)
2035 put_page(page);
2036 return page != NULL;
2037}
2038
2039static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
2040 unsigned long address, pte_t *ptep, unsigned int flags)
2041{
2042 struct hstate *h = hstate_vma(vma);
2043 int ret = VM_FAULT_SIGBUS;
2044 pgoff_t idx;
2045 unsigned long size;
2046 struct page *page;
2047 struct address_space *mapping;
2048 pte_t new_pte;
2049
2050
2051
2052
2053
2054
2055 if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
2056 printk(KERN_WARNING
2057 "PID %d killed due to inadequate hugepage pool\n",
2058 current->pid);
2059 return ret;
2060 }
2061
2062 mapping = vma->vm_file->f_mapping;
2063 idx = vma_hugecache_offset(h, vma, address);
2064
2065
2066
2067
2068
2069retry:
2070 page = find_lock_page(mapping, idx);
2071 if (!page) {
2072 size = i_size_read(mapping->host) >> huge_page_shift(h);
2073 if (idx >= size)
2074 goto out;
2075 page = alloc_huge_page(vma, address, 0);
2076 if (IS_ERR(page)) {
2077 ret = -PTR_ERR(page);
2078 goto out;
2079 }
2080 clear_huge_page(page, address, huge_page_size(h));
2081 __SetPageUptodate(page);
2082
2083 if (vma->vm_flags & VM_MAYSHARE) {
2084 int err;
2085 struct inode *inode = mapping->host;
2086
2087 err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
2088 if (err) {
2089 put_page(page);
2090 if (err == -EEXIST)
2091 goto retry;
2092 goto out;
2093 }
2094
2095 spin_lock(&inode->i_lock);
2096 inode->i_blocks += blocks_per_huge_page(h);
2097 spin_unlock(&inode->i_lock);
2098 } else
2099 lock_page(page);
2100 }
2101
2102
2103
2104
2105
2106
2107
2108 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
2109 if (vma_needs_reservation(h, vma, address) < 0) {
2110 ret = VM_FAULT_OOM;
2111 goto backout_unlocked;
2112 }
2113
2114 spin_lock(&mm->page_table_lock);
2115 size = i_size_read(mapping->host) >> huge_page_shift(h);
2116 if (idx >= size)
2117 goto backout;
2118
2119 ret = 0;
2120 if (!huge_pte_none(huge_ptep_get(ptep)))
2121 goto backout;
2122
2123 new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
2124 && (vma->vm_flags & VM_SHARED)));
2125 set_huge_pte_at(mm, address, ptep, new_pte);
2126
2127 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
2128
2129 ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
2130 }
2131
2132 spin_unlock(&mm->page_table_lock);
2133 unlock_page(page);
2134out:
2135 return ret;
2136
2137backout:
2138 spin_unlock(&mm->page_table_lock);
2139backout_unlocked:
2140 unlock_page(page);
2141 put_page(page);
2142 goto out;
2143}
2144
2145int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2146 unsigned long address, unsigned int flags)
2147{
2148 pte_t *ptep;
2149 pte_t entry;
2150 int ret;
2151 struct page *pagecache_page = NULL;
2152 static DEFINE_MUTEX(hugetlb_instantiation_mutex);
2153 struct hstate *h = hstate_vma(vma);
2154
2155 ptep = huge_pte_alloc(mm, address, huge_page_size(h));
2156 if (!ptep)
2157 return VM_FAULT_OOM;
2158
2159
2160
2161
2162
2163
2164 mutex_lock(&hugetlb_instantiation_mutex);
2165 entry = huge_ptep_get(ptep);
2166 if (huge_pte_none(entry)) {
2167 ret = hugetlb_no_page(mm, vma, address, ptep, flags);
2168 goto out_mutex;
2169 }
2170
2171 ret = 0;
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181 if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
2182 if (vma_needs_reservation(h, vma, address) < 0) {
2183 ret = VM_FAULT_OOM;
2184 goto out_mutex;
2185 }
2186
2187 if (!(vma->vm_flags & VM_MAYSHARE))
2188 pagecache_page = hugetlbfs_pagecache_page(h,
2189 vma, address);
2190 }
2191
2192 spin_lock(&mm->page_table_lock);
2193
2194 if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
2195 goto out_page_table_lock;
2196
2197
2198 if (flags & FAULT_FLAG_WRITE) {
2199 if (!pte_write(entry)) {
2200 ret = hugetlb_cow(mm, vma, address, ptep, entry,
2201 pagecache_page);
2202 goto out_page_table_lock;
2203 }
2204 entry = pte_mkdirty(entry);
2205 }
2206 entry = pte_mkyoung(entry);
2207 if (huge_ptep_set_access_flags(vma, address, ptep, entry,
2208 flags & FAULT_FLAG_WRITE))
2209 update_mmu_cache(vma, address, entry);
2210
2211out_page_table_lock:
2212 spin_unlock(&mm->page_table_lock);
2213
2214 if (pagecache_page) {
2215 unlock_page(pagecache_page);
2216 put_page(pagecache_page);
2217 }
2218
2219out_mutex:
2220 mutex_unlock(&hugetlb_instantiation_mutex);
2221
2222 return ret;
2223}
2224
2225
2226__attribute__((weak)) struct page *
2227follow_huge_pud(struct mm_struct *mm, unsigned long address,
2228 pud_t *pud, int write)
2229{
2230 BUG();
2231 return NULL;
2232}
2233
2234int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
2235 struct page **pages, struct vm_area_struct **vmas,
2236 unsigned long *position, int *length, int i,
2237 unsigned int flags)
2238{
2239 unsigned long pfn_offset;
2240 unsigned long vaddr = *position;
2241 int remainder = *length;
2242 struct hstate *h = hstate_vma(vma);
2243
2244 spin_lock(&mm->page_table_lock);
2245 while (vaddr < vma->vm_end && remainder) {
2246 pte_t *pte;
2247 int absent;
2248 struct page *page;
2249
2250
2251
2252
2253
2254
2255 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
2256 absent = !pte || huge_pte_none(huge_ptep_get(pte));
2257
2258
2259
2260
2261
2262
2263
2264
2265 if (absent && (flags & FOLL_DUMP) &&
2266 !hugetlbfs_pagecache_present(h, vma, vaddr)) {
2267 remainder = 0;
2268 break;
2269 }
2270
2271 if (absent ||
2272 ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
2273 int ret;
2274
2275 spin_unlock(&mm->page_table_lock);
2276 ret = hugetlb_fault(mm, vma, vaddr,
2277 (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
2278 spin_lock(&mm->page_table_lock);
2279 if (!(ret & VM_FAULT_ERROR))
2280 continue;
2281
2282 remainder = 0;
2283 break;
2284 }
2285
2286 pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
2287 page = pte_page(huge_ptep_get(pte));
2288same_page:
2289 if (pages) {
2290 pages[i] = mem_map_offset(page, pfn_offset);
2291 get_page(pages[i]);
2292 }
2293
2294 if (vmas)
2295 vmas[i] = vma;
2296
2297 vaddr += PAGE_SIZE;
2298 ++pfn_offset;
2299 --remainder;
2300 ++i;
2301 if (vaddr < vma->vm_end && remainder &&
2302 pfn_offset < pages_per_huge_page(h)) {
2303
2304
2305
2306
2307 goto same_page;
2308 }
2309 }
2310 spin_unlock(&mm->page_table_lock);
2311 *length = remainder;
2312 *position = vaddr;
2313
2314 return i ? i : -EFAULT;
2315}
2316
2317void hugetlb_change_protection(struct vm_area_struct *vma,
2318 unsigned long address, unsigned long end, pgprot_t newprot)
2319{
2320 struct mm_struct *mm = vma->vm_mm;
2321 unsigned long start = address;
2322 pte_t *ptep;
2323 pte_t pte;
2324 struct hstate *h = hstate_vma(vma);
2325
2326 BUG_ON(address >= end);
2327 flush_cache_range(vma, address, end);
2328
2329 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
2330 spin_lock(&mm->page_table_lock);
2331 for (; address < end; address += huge_page_size(h)) {
2332 ptep = huge_pte_offset(mm, address);
2333 if (!ptep)
2334 continue;
2335 if (huge_pmd_unshare(mm, &address, ptep))
2336 continue;
2337 if (!huge_pte_none(huge_ptep_get(ptep))) {
2338 pte = huge_ptep_get_and_clear(mm, address, ptep);
2339 pte = pte_mkhuge(pte_modify(pte, newprot));
2340 set_huge_pte_at(mm, address, ptep, pte);
2341 }
2342 }
2343 spin_unlock(&mm->page_table_lock);
2344 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
2345
2346 flush_tlb_range(vma, start, end);
2347}
2348
2349int hugetlb_reserve_pages(struct inode *inode,
2350 long from, long to,
2351 struct vm_area_struct *vma,
2352 int acctflag)
2353{
2354 long ret, chg;
2355 struct hstate *h = hstate_inode(inode);
2356
2357
2358
2359
2360
2361
2362 if (acctflag & VM_NORESERVE)
2363 return 0;
2364
2365
2366
2367
2368
2369
2370
2371 if (!vma || vma->vm_flags & VM_MAYSHARE)
2372 chg = region_chg(&inode->i_mapping->private_list, from, to);
2373 else {
2374 struct resv_map *resv_map = resv_map_alloc();
2375 if (!resv_map)
2376 return -ENOMEM;
2377
2378 chg = to - from;
2379
2380 set_vma_resv_map(vma, resv_map);
2381 set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
2382 }
2383
2384 if (chg < 0)
2385 return chg;
2386
2387
2388 if (hugetlb_get_quota(inode->i_mapping, chg))
2389 return -ENOSPC;
2390
2391
2392
2393
2394
2395 ret = hugetlb_acct_memory(h, chg);
2396 if (ret < 0) {
2397 hugetlb_put_quota(inode->i_mapping, chg);
2398 return ret;
2399 }
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412 if (!vma || vma->vm_flags & VM_MAYSHARE)
2413 region_add(&inode->i_mapping->private_list, from, to);
2414 return 0;
2415}
2416
2417void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
2418{
2419 struct hstate *h = hstate_inode(inode);
2420 long chg = region_truncate(&inode->i_mapping->private_list, offset);
2421
2422 spin_lock(&inode->i_lock);
2423 inode->i_blocks -= (blocks_per_huge_page(h) * freed);
2424 spin_unlock(&inode->i_lock);
2425
2426 hugetlb_put_quota(inode->i_mapping, (chg - freed));
2427 hugetlb_acct_memory(h, -(chg - freed));
2428}
2429