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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/snapshot.c
4 *
5 * This file provides system snapshot/restore functionality for swsusp.
6 *
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 */
10
11#define pr_fmt(fmt) "PM: hibernation: " fmt
12
13#include <linux/version.h>
14#include <linux/module.h>
15#include <linux/mm.h>
16#include <linux/suspend.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/spinlock.h>
20#include <linux/kernel.h>
21#include <linux/pm.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/memblock.h>
25#include <linux/nmi.h>
26#include <linux/syscalls.h>
27#include <linux/console.h>
28#include <linux/highmem.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31#include <linux/compiler.h>
32#include <linux/ktime.h>
33#include <linux/set_memory.h>
34
35#include <linux/uaccess.h>
36#include <asm/mmu_context.h>
37#include <asm/tlbflush.h>
38#include <asm/io.h>
39
40#include "power.h"
41
42#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
43static bool hibernate_restore_protection;
44static bool hibernate_restore_protection_active;
45
46void enable_restore_image_protection(void)
47{
48 hibernate_restore_protection = true;
49}
50
51static inline void hibernate_restore_protection_begin(void)
52{
53 hibernate_restore_protection_active = hibernate_restore_protection;
54}
55
56static inline void hibernate_restore_protection_end(void)
57{
58 hibernate_restore_protection_active = false;
59}
60
61static inline void hibernate_restore_protect_page(void *page_address)
62{
63 if (hibernate_restore_protection_active)
64 set_memory_ro((unsigned long)page_address, 1);
65}
66
67static inline void hibernate_restore_unprotect_page(void *page_address)
68{
69 if (hibernate_restore_protection_active)
70 set_memory_rw((unsigned long)page_address, 1);
71}
72#else
73static inline void hibernate_restore_protection_begin(void) {}
74static inline void hibernate_restore_protection_end(void) {}
75static inline void hibernate_restore_protect_page(void *page_address) {}
76static inline void hibernate_restore_unprotect_page(void *page_address) {}
77#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
78
79static int swsusp_page_is_free(struct page *);
80static void swsusp_set_page_forbidden(struct page *);
81static void swsusp_unset_page_forbidden(struct page *);
82
83/*
84 * Number of bytes to reserve for memory allocations made by device drivers
85 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
86 * cause image creation to fail (tunable via /sys/power/reserved_size).
87 */
88unsigned long reserved_size;
89
90void __init hibernate_reserved_size_init(void)
91{
92 reserved_size = SPARE_PAGES * PAGE_SIZE;
93}
94
95/*
96 * Preferred image size in bytes (tunable via /sys/power/image_size).
97 * When it is set to N, swsusp will do its best to ensure the image
98 * size will not exceed N bytes, but if that is impossible, it will
99 * try to create the smallest image possible.
100 */
101unsigned long image_size;
102
103void __init hibernate_image_size_init(void)
104{
105 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
106}
107
108/*
109 * List of PBEs needed for restoring the pages that were allocated before
110 * the suspend and included in the suspend image, but have also been
111 * allocated by the "resume" kernel, so their contents cannot be written
112 * directly to their "original" page frames.
113 */
114struct pbe *restore_pblist;
115
116/* struct linked_page is used to build chains of pages */
117
118#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
119
120struct linked_page {
121 struct linked_page *next;
122 char data[LINKED_PAGE_DATA_SIZE];
123} __packed;
124
125/*
126 * List of "safe" pages (ie. pages that were not used by the image kernel
127 * before hibernation) that may be used as temporary storage for image kernel
128 * memory contents.
129 */
130static struct linked_page *safe_pages_list;
131
132/* Pointer to an auxiliary buffer (1 page) */
133static void *buffer;
134
135#define PG_ANY 0
136#define PG_SAFE 1
137#define PG_UNSAFE_CLEAR 1
138#define PG_UNSAFE_KEEP 0
139
140static unsigned int allocated_unsafe_pages;
141
142/**
143 * get_image_page - Allocate a page for a hibernation image.
144 * @gfp_mask: GFP mask for the allocation.
145 * @safe_needed: Get pages that were not used before hibernation (restore only)
146 *
147 * During image restoration, for storing the PBE list and the image data, we can
148 * only use memory pages that do not conflict with the pages used before
149 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
150 * using allocated_unsafe_pages.
151 *
152 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
153 * swsusp_free() can release it.
154 */
155static void *get_image_page(gfp_t gfp_mask, int safe_needed)
156{
157 void *res;
158
159 res = (void *)get_zeroed_page(gfp_mask);
160 if (safe_needed)
161 while (res && swsusp_page_is_free(virt_to_page(res))) {
162 /* The page is unsafe, mark it for swsusp_free() */
163 swsusp_set_page_forbidden(virt_to_page(res));
164 allocated_unsafe_pages++;
165 res = (void *)get_zeroed_page(gfp_mask);
166 }
167 if (res) {
168 swsusp_set_page_forbidden(virt_to_page(res));
169 swsusp_set_page_free(virt_to_page(res));
170 }
171 return res;
172}
173
174static void *__get_safe_page(gfp_t gfp_mask)
175{
176 if (safe_pages_list) {
177 void *ret = safe_pages_list;
178
179 safe_pages_list = safe_pages_list->next;
180 memset(ret, 0, PAGE_SIZE);
181 return ret;
182 }
183 return get_image_page(gfp_mask, PG_SAFE);
184}
185
186unsigned long get_safe_page(gfp_t gfp_mask)
187{
188 return (unsigned long)__get_safe_page(gfp_mask);
189}
190
191static struct page *alloc_image_page(gfp_t gfp_mask)
192{
193 struct page *page;
194
195 page = alloc_page(gfp_mask);
196 if (page) {
197 swsusp_set_page_forbidden(page);
198 swsusp_set_page_free(page);
199 }
200 return page;
201}
202
203static void recycle_safe_page(void *page_address)
204{
205 struct linked_page *lp = page_address;
206
207 lp->next = safe_pages_list;
208 safe_pages_list = lp;
209}
210
211/**
212 * free_image_page - Free a page allocated for hibernation image.
213 * @addr: Address of the page to free.
214 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
215 *
216 * The page to free should have been allocated by get_image_page() (page flags
217 * set by it are affected).
218 */
219static inline void free_image_page(void *addr, int clear_nosave_free)
220{
221 struct page *page;
222
223 BUG_ON(!virt_addr_valid(addr));
224
225 page = virt_to_page(addr);
226
227 swsusp_unset_page_forbidden(page);
228 if (clear_nosave_free)
229 swsusp_unset_page_free(page);
230
231 __free_page(page);
232}
233
234static inline void free_list_of_pages(struct linked_page *list,
235 int clear_page_nosave)
236{
237 while (list) {
238 struct linked_page *lp = list->next;
239
240 free_image_page(list, clear_page_nosave);
241 list = lp;
242 }
243}
244
245/*
246 * struct chain_allocator is used for allocating small objects out of
247 * a linked list of pages called 'the chain'.
248 *
249 * The chain grows each time when there is no room for a new object in
250 * the current page. The allocated objects cannot be freed individually.
251 * It is only possible to free them all at once, by freeing the entire
252 * chain.
253 *
254 * NOTE: The chain allocator may be inefficient if the allocated objects
255 * are not much smaller than PAGE_SIZE.
256 */
257struct chain_allocator {
258 struct linked_page *chain; /* the chain */
259 unsigned int used_space; /* total size of objects allocated out
260 of the current page */
261 gfp_t gfp_mask; /* mask for allocating pages */
262 int safe_needed; /* if set, only "safe" pages are allocated */
263};
264
265static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
266 int safe_needed)
267{
268 ca->chain = NULL;
269 ca->used_space = LINKED_PAGE_DATA_SIZE;
270 ca->gfp_mask = gfp_mask;
271 ca->safe_needed = safe_needed;
272}
273
274static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
275{
276 void *ret;
277
278 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
279 struct linked_page *lp;
280
281 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
282 get_image_page(ca->gfp_mask, PG_ANY);
283 if (!lp)
284 return NULL;
285
286 lp->next = ca->chain;
287 ca->chain = lp;
288 ca->used_space = 0;
289 }
290 ret = ca->chain->data + ca->used_space;
291 ca->used_space += size;
292 return ret;
293}
294
295/**
296 * Data types related to memory bitmaps.
297 *
298 * Memory bitmap is a structure consiting of many linked lists of
299 * objects. The main list's elements are of type struct zone_bitmap
300 * and each of them corresonds to one zone. For each zone bitmap
301 * object there is a list of objects of type struct bm_block that
302 * represent each blocks of bitmap in which information is stored.
303 *
304 * struct memory_bitmap contains a pointer to the main list of zone
305 * bitmap objects, a struct bm_position used for browsing the bitmap,
306 * and a pointer to the list of pages used for allocating all of the
307 * zone bitmap objects and bitmap block objects.
308 *
309 * NOTE: It has to be possible to lay out the bitmap in memory
310 * using only allocations of order 0. Additionally, the bitmap is
311 * designed to work with arbitrary number of zones (this is over the
312 * top for now, but let's avoid making unnecessary assumptions ;-).
313 *
314 * struct zone_bitmap contains a pointer to a list of bitmap block
315 * objects and a pointer to the bitmap block object that has been
316 * most recently used for setting bits. Additionally, it contains the
317 * PFNs that correspond to the start and end of the represented zone.
318 *
319 * struct bm_block contains a pointer to the memory page in which
320 * information is stored (in the form of a block of bitmap)
321 * It also contains the pfns that correspond to the start and end of
322 * the represented memory area.
323 *
324 * The memory bitmap is organized as a radix tree to guarantee fast random
325 * access to the bits. There is one radix tree for each zone (as returned
326 * from create_mem_extents).
327 *
328 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
329 * two linked lists for the nodes of the tree, one for the inner nodes and
330 * one for the leave nodes. The linked leave nodes are used for fast linear
331 * access of the memory bitmap.
332 *
333 * The struct rtree_node represents one node of the radix tree.
334 */
335
336#define BM_END_OF_MAP (~0UL)
337
338#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
339#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
340#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
341
342/*
343 * struct rtree_node is a wrapper struct to link the nodes
344 * of the rtree together for easy linear iteration over
345 * bits and easy freeing
346 */
347struct rtree_node {
348 struct list_head list;
349 unsigned long *data;
350};
351
352/*
353 * struct mem_zone_bm_rtree represents a bitmap used for one
354 * populated memory zone.
355 */
356struct mem_zone_bm_rtree {
357 struct list_head list; /* Link Zones together */
358 struct list_head nodes; /* Radix Tree inner nodes */
359 struct list_head leaves; /* Radix Tree leaves */
360 unsigned long start_pfn; /* Zone start page frame */
361 unsigned long end_pfn; /* Zone end page frame + 1 */
362 struct rtree_node *rtree; /* Radix Tree Root */
363 int levels; /* Number of Radix Tree Levels */
364 unsigned int blocks; /* Number of Bitmap Blocks */
365};
366
367/* strcut bm_position is used for browsing memory bitmaps */
368
369struct bm_position {
370 struct mem_zone_bm_rtree *zone;
371 struct rtree_node *node;
372 unsigned long node_pfn;
373 int node_bit;
374};
375
376struct memory_bitmap {
377 struct list_head zones;
378 struct linked_page *p_list; /* list of pages used to store zone
379 bitmap objects and bitmap block
380 objects */
381 struct bm_position cur; /* most recently used bit position */
382};
383
384/* Functions that operate on memory bitmaps */
385
386#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
387#if BITS_PER_LONG == 32
388#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
389#else
390#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
391#endif
392#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
393
394/**
395 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
396 *
397 * This function is used to allocate inner nodes as well as the
398 * leave nodes of the radix tree. It also adds the node to the
399 * corresponding linked list passed in by the *list parameter.
400 */
401static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
402 struct chain_allocator *ca,
403 struct list_head *list)
404{
405 struct rtree_node *node;
406
407 node = chain_alloc(ca, sizeof(struct rtree_node));
408 if (!node)
409 return NULL;
410
411 node->data = get_image_page(gfp_mask, safe_needed);
412 if (!node->data)
413 return NULL;
414
415 list_add_tail(&node->list, list);
416
417 return node;
418}
419
420/**
421 * add_rtree_block - Add a new leave node to the radix tree.
422 *
423 * The leave nodes need to be allocated in order to keep the leaves
424 * linked list in order. This is guaranteed by the zone->blocks
425 * counter.
426 */
427static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
428 int safe_needed, struct chain_allocator *ca)
429{
430 struct rtree_node *node, *block, **dst;
431 unsigned int levels_needed, block_nr;
432 int i;
433
434 block_nr = zone->blocks;
435 levels_needed = 0;
436
437 /* How many levels do we need for this block nr? */
438 while (block_nr) {
439 levels_needed += 1;
440 block_nr >>= BM_RTREE_LEVEL_SHIFT;
441 }
442
443 /* Make sure the rtree has enough levels */
444 for (i = zone->levels; i < levels_needed; i++) {
445 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
446 &zone->nodes);
447 if (!node)
448 return -ENOMEM;
449
450 node->data[0] = (unsigned long)zone->rtree;
451 zone->rtree = node;
452 zone->levels += 1;
453 }
454
455 /* Allocate new block */
456 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
457 if (!block)
458 return -ENOMEM;
459
460 /* Now walk the rtree to insert the block */
461 node = zone->rtree;
462 dst = &zone->rtree;
463 block_nr = zone->blocks;
464 for (i = zone->levels; i > 0; i--) {
465 int index;
466
467 if (!node) {
468 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
469 &zone->nodes);
470 if (!node)
471 return -ENOMEM;
472 *dst = node;
473 }
474
475 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
476 index &= BM_RTREE_LEVEL_MASK;
477 dst = (struct rtree_node **)&((*dst)->data[index]);
478 node = *dst;
479 }
480
481 zone->blocks += 1;
482 *dst = block;
483
484 return 0;
485}
486
487static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
488 int clear_nosave_free);
489
490/**
491 * create_zone_bm_rtree - Create a radix tree for one zone.
492 *
493 * Allocated the mem_zone_bm_rtree structure and initializes it.
494 * This function also allocated and builds the radix tree for the
495 * zone.
496 */
497static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
498 int safe_needed,
499 struct chain_allocator *ca,
500 unsigned long start,
501 unsigned long end)
502{
503 struct mem_zone_bm_rtree *zone;
504 unsigned int i, nr_blocks;
505 unsigned long pages;
506
507 pages = end - start;
508 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
509 if (!zone)
510 return NULL;
511
512 INIT_LIST_HEAD(&zone->nodes);
513 INIT_LIST_HEAD(&zone->leaves);
514 zone->start_pfn = start;
515 zone->end_pfn = end;
516 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
517
518 for (i = 0; i < nr_blocks; i++) {
519 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
520 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
521 return NULL;
522 }
523 }
524
525 return zone;
526}
527
528/**
529 * free_zone_bm_rtree - Free the memory of the radix tree.
530 *
531 * Free all node pages of the radix tree. The mem_zone_bm_rtree
532 * structure itself is not freed here nor are the rtree_node
533 * structs.
534 */
535static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
536 int clear_nosave_free)
537{
538 struct rtree_node *node;
539
540 list_for_each_entry(node, &zone->nodes, list)
541 free_image_page(node->data, clear_nosave_free);
542
543 list_for_each_entry(node, &zone->leaves, list)
544 free_image_page(node->data, clear_nosave_free);
545}
546
547static void memory_bm_position_reset(struct memory_bitmap *bm)
548{
549 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
550 list);
551 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
552 struct rtree_node, list);
553 bm->cur.node_pfn = 0;
554 bm->cur.node_bit = 0;
555}
556
557static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
558
559struct mem_extent {
560 struct list_head hook;
561 unsigned long start;
562 unsigned long end;
563};
564
565/**
566 * free_mem_extents - Free a list of memory extents.
567 * @list: List of extents to free.
568 */
569static void free_mem_extents(struct list_head *list)
570{
571 struct mem_extent *ext, *aux;
572
573 list_for_each_entry_safe(ext, aux, list, hook) {
574 list_del(&ext->hook);
575 kfree(ext);
576 }
577}
578
579/**
580 * create_mem_extents - Create a list of memory extents.
581 * @list: List to put the extents into.
582 * @gfp_mask: Mask to use for memory allocations.
583 *
584 * The extents represent contiguous ranges of PFNs.
585 */
586static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
587{
588 struct zone *zone;
589
590 INIT_LIST_HEAD(list);
591
592 for_each_populated_zone(zone) {
593 unsigned long zone_start, zone_end;
594 struct mem_extent *ext, *cur, *aux;
595
596 zone_start = zone->zone_start_pfn;
597 zone_end = zone_end_pfn(zone);
598
599 list_for_each_entry(ext, list, hook)
600 if (zone_start <= ext->end)
601 break;
602
603 if (&ext->hook == list || zone_end < ext->start) {
604 /* New extent is necessary */
605 struct mem_extent *new_ext;
606
607 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
608 if (!new_ext) {
609 free_mem_extents(list);
610 return -ENOMEM;
611 }
612 new_ext->start = zone_start;
613 new_ext->end = zone_end;
614 list_add_tail(&new_ext->hook, &ext->hook);
615 continue;
616 }
617
618 /* Merge this zone's range of PFNs with the existing one */
619 if (zone_start < ext->start)
620 ext->start = zone_start;
621 if (zone_end > ext->end)
622 ext->end = zone_end;
623
624 /* More merging may be possible */
625 cur = ext;
626 list_for_each_entry_safe_continue(cur, aux, list, hook) {
627 if (zone_end < cur->start)
628 break;
629 if (zone_end < cur->end)
630 ext->end = cur->end;
631 list_del(&cur->hook);
632 kfree(cur);
633 }
634 }
635
636 return 0;
637}
638
639/**
640 * memory_bm_create - Allocate memory for a memory bitmap.
641 */
642static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
643 int safe_needed)
644{
645 struct chain_allocator ca;
646 struct list_head mem_extents;
647 struct mem_extent *ext;
648 int error;
649
650 chain_init(&ca, gfp_mask, safe_needed);
651 INIT_LIST_HEAD(&bm->zones);
652
653 error = create_mem_extents(&mem_extents, gfp_mask);
654 if (error)
655 return error;
656
657 list_for_each_entry(ext, &mem_extents, hook) {
658 struct mem_zone_bm_rtree *zone;
659
660 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
661 ext->start, ext->end);
662 if (!zone) {
663 error = -ENOMEM;
664 goto Error;
665 }
666 list_add_tail(&zone->list, &bm->zones);
667 }
668
669 bm->p_list = ca.chain;
670 memory_bm_position_reset(bm);
671 Exit:
672 free_mem_extents(&mem_extents);
673 return error;
674
675 Error:
676 bm->p_list = ca.chain;
677 memory_bm_free(bm, PG_UNSAFE_CLEAR);
678 goto Exit;
679}
680
681/**
682 * memory_bm_free - Free memory occupied by the memory bitmap.
683 * @bm: Memory bitmap.
684 */
685static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
686{
687 struct mem_zone_bm_rtree *zone;
688
689 list_for_each_entry(zone, &bm->zones, list)
690 free_zone_bm_rtree(zone, clear_nosave_free);
691
692 free_list_of_pages(bm->p_list, clear_nosave_free);
693
694 INIT_LIST_HEAD(&bm->zones);
695}
696
697/**
698 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
699 *
700 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
701 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
702 *
703 * Walk the radix tree to find the page containing the bit that represents @pfn
704 * and return the position of the bit in @addr and @bit_nr.
705 */
706static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
707 void **addr, unsigned int *bit_nr)
708{
709 struct mem_zone_bm_rtree *curr, *zone;
710 struct rtree_node *node;
711 int i, block_nr;
712
713 zone = bm->cur.zone;
714
715 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
716 goto zone_found;
717
718 zone = NULL;
719
720 /* Find the right zone */
721 list_for_each_entry(curr, &bm->zones, list) {
722 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
723 zone = curr;
724 break;
725 }
726 }
727
728 if (!zone)
729 return -EFAULT;
730
731zone_found:
732 /*
733 * We have found the zone. Now walk the radix tree to find the leaf node
734 * for our PFN.
735 */
736
737 /*
738 * If the zone we wish to scan is the the current zone and the
739 * pfn falls into the current node then we do not need to walk
740 * the tree.
741 */
742 node = bm->cur.node;
743 if (zone == bm->cur.zone &&
744 ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
745 goto node_found;
746
747 node = zone->rtree;
748 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
749
750 for (i = zone->levels; i > 0; i--) {
751 int index;
752
753 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
754 index &= BM_RTREE_LEVEL_MASK;
755 BUG_ON(node->data[index] == 0);
756 node = (struct rtree_node *)node->data[index];
757 }
758
759node_found:
760 /* Update last position */
761 bm->cur.zone = zone;
762 bm->cur.node = node;
763 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
764
765 /* Set return values */
766 *addr = node->data;
767 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
768
769 return 0;
770}
771
772static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
773{
774 void *addr;
775 unsigned int bit;
776 int error;
777
778 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
779 BUG_ON(error);
780 set_bit(bit, addr);
781}
782
783static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
784{
785 void *addr;
786 unsigned int bit;
787 int error;
788
789 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
790 if (!error)
791 set_bit(bit, addr);
792
793 return error;
794}
795
796static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
797{
798 void *addr;
799 unsigned int bit;
800 int error;
801
802 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
803 BUG_ON(error);
804 clear_bit(bit, addr);
805}
806
807static void memory_bm_clear_current(struct memory_bitmap *bm)
808{
809 int bit;
810
811 bit = max(bm->cur.node_bit - 1, 0);
812 clear_bit(bit, bm->cur.node->data);
813}
814
815static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
816{
817 void *addr;
818 unsigned int bit;
819 int error;
820
821 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
822 BUG_ON(error);
823 return test_bit(bit, addr);
824}
825
826static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
827{
828 void *addr;
829 unsigned int bit;
830
831 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
832}
833
834/*
835 * rtree_next_node - Jump to the next leaf node.
836 *
837 * Set the position to the beginning of the next node in the
838 * memory bitmap. This is either the next node in the current
839 * zone's radix tree or the first node in the radix tree of the
840 * next zone.
841 *
842 * Return true if there is a next node, false otherwise.
843 */
844static bool rtree_next_node(struct memory_bitmap *bm)
845{
846 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
847 bm->cur.node = list_entry(bm->cur.node->list.next,
848 struct rtree_node, list);
849 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
850 bm->cur.node_bit = 0;
851 touch_softlockup_watchdog();
852 return true;
853 }
854
855 /* No more nodes, goto next zone */
856 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
857 bm->cur.zone = list_entry(bm->cur.zone->list.next,
858 struct mem_zone_bm_rtree, list);
859 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
860 struct rtree_node, list);
861 bm->cur.node_pfn = 0;
862 bm->cur.node_bit = 0;
863 return true;
864 }
865
866 /* No more zones */
867 return false;
868}
869
870/**
871 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
872 * @bm: Memory bitmap.
873 *
874 * Starting from the last returned position this function searches for the next
875 * set bit in @bm and returns the PFN represented by it. If no more bits are
876 * set, BM_END_OF_MAP is returned.
877 *
878 * It is required to run memory_bm_position_reset() before the first call to
879 * this function for the given memory bitmap.
880 */
881static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
882{
883 unsigned long bits, pfn, pages;
884 int bit;
885
886 do {
887 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
888 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
889 bit = find_next_bit(bm->cur.node->data, bits,
890 bm->cur.node_bit);
891 if (bit < bits) {
892 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
893 bm->cur.node_bit = bit + 1;
894 return pfn;
895 }
896 } while (rtree_next_node(bm));
897
898 return BM_END_OF_MAP;
899}
900
901/*
902 * This structure represents a range of page frames the contents of which
903 * should not be saved during hibernation.
904 */
905struct nosave_region {
906 struct list_head list;
907 unsigned long start_pfn;
908 unsigned long end_pfn;
909};
910
911static LIST_HEAD(nosave_regions);
912
913static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
914{
915 struct rtree_node *node;
916
917 list_for_each_entry(node, &zone->nodes, list)
918 recycle_safe_page(node->data);
919
920 list_for_each_entry(node, &zone->leaves, list)
921 recycle_safe_page(node->data);
922}
923
924static void memory_bm_recycle(struct memory_bitmap *bm)
925{
926 struct mem_zone_bm_rtree *zone;
927 struct linked_page *p_list;
928
929 list_for_each_entry(zone, &bm->zones, list)
930 recycle_zone_bm_rtree(zone);
931
932 p_list = bm->p_list;
933 while (p_list) {
934 struct linked_page *lp = p_list;
935
936 p_list = lp->next;
937 recycle_safe_page(lp);
938 }
939}
940
941/**
942 * register_nosave_region - Register a region of unsaveable memory.
943 *
944 * Register a range of page frames the contents of which should not be saved
945 * during hibernation (to be used in the early initialization code).
946 */
947void __init __register_nosave_region(unsigned long start_pfn,
948 unsigned long end_pfn, int use_kmalloc)
949{
950 struct nosave_region *region;
951
952 if (start_pfn >= end_pfn)
953 return;
954
955 if (!list_empty(&nosave_regions)) {
956 /* Try to extend the previous region (they should be sorted) */
957 region = list_entry(nosave_regions.prev,
958 struct nosave_region, list);
959 if (region->end_pfn == start_pfn) {
960 region->end_pfn = end_pfn;
961 goto Report;
962 }
963 }
964 if (use_kmalloc) {
965 /* During init, this shouldn't fail */
966 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
967 BUG_ON(!region);
968 } else {
969 /* This allocation cannot fail */
970 region = memblock_alloc(sizeof(struct nosave_region),
971 SMP_CACHE_BYTES);
972 if (!region)
973 panic("%s: Failed to allocate %zu bytes\n", __func__,
974 sizeof(struct nosave_region));
975 }
976 region->start_pfn = start_pfn;
977 region->end_pfn = end_pfn;
978 list_add_tail(®ion->list, &nosave_regions);
979 Report:
980 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
981 (unsigned long long) start_pfn << PAGE_SHIFT,
982 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
983}
984
985/*
986 * Set bits in this map correspond to the page frames the contents of which
987 * should not be saved during the suspend.
988 */
989static struct memory_bitmap *forbidden_pages_map;
990
991/* Set bits in this map correspond to free page frames. */
992static struct memory_bitmap *free_pages_map;
993
994/*
995 * Each page frame allocated for creating the image is marked by setting the
996 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
997 */
998
999void swsusp_set_page_free(struct page *page)
1000{
1001 if (free_pages_map)
1002 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
1003}
1004
1005static int swsusp_page_is_free(struct page *page)
1006{
1007 return free_pages_map ?
1008 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1009}
1010
1011void swsusp_unset_page_free(struct page *page)
1012{
1013 if (free_pages_map)
1014 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1015}
1016
1017static void swsusp_set_page_forbidden(struct page *page)
1018{
1019 if (forbidden_pages_map)
1020 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1021}
1022
1023int swsusp_page_is_forbidden(struct page *page)
1024{
1025 return forbidden_pages_map ?
1026 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1027}
1028
1029static void swsusp_unset_page_forbidden(struct page *page)
1030{
1031 if (forbidden_pages_map)
1032 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1033}
1034
1035/**
1036 * mark_nosave_pages - Mark pages that should not be saved.
1037 * @bm: Memory bitmap.
1038 *
1039 * Set the bits in @bm that correspond to the page frames the contents of which
1040 * should not be saved.
1041 */
1042static void mark_nosave_pages(struct memory_bitmap *bm)
1043{
1044 struct nosave_region *region;
1045
1046 if (list_empty(&nosave_regions))
1047 return;
1048
1049 list_for_each_entry(region, &nosave_regions, list) {
1050 unsigned long pfn;
1051
1052 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1053 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1054 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1055 - 1);
1056
1057 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1058 if (pfn_valid(pfn)) {
1059 /*
1060 * It is safe to ignore the result of
1061 * mem_bm_set_bit_check() here, since we won't
1062 * touch the PFNs for which the error is
1063 * returned anyway.
1064 */
1065 mem_bm_set_bit_check(bm, pfn);
1066 }
1067 }
1068}
1069
1070/**
1071 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1072 *
1073 * Create bitmaps needed for marking page frames that should not be saved and
1074 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1075 * only modified if everything goes well, because we don't want the bits to be
1076 * touched before both bitmaps are set up.
1077 */
1078int create_basic_memory_bitmaps(void)
1079{
1080 struct memory_bitmap *bm1, *bm2;
1081 int error = 0;
1082
1083 if (forbidden_pages_map && free_pages_map)
1084 return 0;
1085 else
1086 BUG_ON(forbidden_pages_map || free_pages_map);
1087
1088 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1089 if (!bm1)
1090 return -ENOMEM;
1091
1092 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1093 if (error)
1094 goto Free_first_object;
1095
1096 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1097 if (!bm2)
1098 goto Free_first_bitmap;
1099
1100 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1101 if (error)
1102 goto Free_second_object;
1103
1104 forbidden_pages_map = bm1;
1105 free_pages_map = bm2;
1106 mark_nosave_pages(forbidden_pages_map);
1107
1108 pr_debug("Basic memory bitmaps created\n");
1109
1110 return 0;
1111
1112 Free_second_object:
1113 kfree(bm2);
1114 Free_first_bitmap:
1115 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1116 Free_first_object:
1117 kfree(bm1);
1118 return -ENOMEM;
1119}
1120
1121/**
1122 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1123 *
1124 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1125 * auxiliary pointers are necessary so that the bitmaps themselves are not
1126 * referred to while they are being freed.
1127 */
1128void free_basic_memory_bitmaps(void)
1129{
1130 struct memory_bitmap *bm1, *bm2;
1131
1132 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1133 return;
1134
1135 bm1 = forbidden_pages_map;
1136 bm2 = free_pages_map;
1137 forbidden_pages_map = NULL;
1138 free_pages_map = NULL;
1139 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1140 kfree(bm1);
1141 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1142 kfree(bm2);
1143
1144 pr_debug("Basic memory bitmaps freed\n");
1145}
1146
1147void clear_free_pages(void)
1148{
1149 struct memory_bitmap *bm = free_pages_map;
1150 unsigned long pfn;
1151
1152 if (WARN_ON(!(free_pages_map)))
1153 return;
1154
1155 if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || want_init_on_free()) {
1156 memory_bm_position_reset(bm);
1157 pfn = memory_bm_next_pfn(bm);
1158 while (pfn != BM_END_OF_MAP) {
1159 if (pfn_valid(pfn))
1160 clear_highpage(pfn_to_page(pfn));
1161
1162 pfn = memory_bm_next_pfn(bm);
1163 }
1164 memory_bm_position_reset(bm);
1165 pr_info("free pages cleared after restore\n");
1166 }
1167}
1168
1169/**
1170 * snapshot_additional_pages - Estimate the number of extra pages needed.
1171 * @zone: Memory zone to carry out the computation for.
1172 *
1173 * Estimate the number of additional pages needed for setting up a hibernation
1174 * image data structures for @zone (usually, the returned value is greater than
1175 * the exact number).
1176 */
1177unsigned int snapshot_additional_pages(struct zone *zone)
1178{
1179 unsigned int rtree, nodes;
1180
1181 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1182 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1183 LINKED_PAGE_DATA_SIZE);
1184 while (nodes > 1) {
1185 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1186 rtree += nodes;
1187 }
1188
1189 return 2 * rtree;
1190}
1191
1192#ifdef CONFIG_HIGHMEM
1193/**
1194 * count_free_highmem_pages - Compute the total number of free highmem pages.
1195 *
1196 * The returned number is system-wide.
1197 */
1198static unsigned int count_free_highmem_pages(void)
1199{
1200 struct zone *zone;
1201 unsigned int cnt = 0;
1202
1203 for_each_populated_zone(zone)
1204 if (is_highmem(zone))
1205 cnt += zone_page_state(zone, NR_FREE_PAGES);
1206
1207 return cnt;
1208}
1209
1210/**
1211 * saveable_highmem_page - Check if a highmem page is saveable.
1212 *
1213 * Determine whether a highmem page should be included in a hibernation image.
1214 *
1215 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1216 * and it isn't part of a free chunk of pages.
1217 */
1218static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1219{
1220 struct page *page;
1221
1222 if (!pfn_valid(pfn))
1223 return NULL;
1224
1225 page = pfn_to_online_page(pfn);
1226 if (!page || page_zone(page) != zone)
1227 return NULL;
1228
1229 BUG_ON(!PageHighMem(page));
1230
1231 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1232 return NULL;
1233
1234 if (PageReserved(page) || PageOffline(page))
1235 return NULL;
1236
1237 if (page_is_guard(page))
1238 return NULL;
1239
1240 return page;
1241}
1242
1243/**
1244 * count_highmem_pages - Compute the total number of saveable highmem pages.
1245 */
1246static unsigned int count_highmem_pages(void)
1247{
1248 struct zone *zone;
1249 unsigned int n = 0;
1250
1251 for_each_populated_zone(zone) {
1252 unsigned long pfn, max_zone_pfn;
1253
1254 if (!is_highmem(zone))
1255 continue;
1256
1257 mark_free_pages(zone);
1258 max_zone_pfn = zone_end_pfn(zone);
1259 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1260 if (saveable_highmem_page(zone, pfn))
1261 n++;
1262 }
1263 return n;
1264}
1265#else
1266static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1267{
1268 return NULL;
1269}
1270#endif /* CONFIG_HIGHMEM */
1271
1272/**
1273 * saveable_page - Check if the given page is saveable.
1274 *
1275 * Determine whether a non-highmem page should be included in a hibernation
1276 * image.
1277 *
1278 * We should save the page if it isn't Nosave, and is not in the range
1279 * of pages statically defined as 'unsaveable', and it isn't part of
1280 * a free chunk of pages.
1281 */
1282static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1283{
1284 struct page *page;
1285
1286 if (!pfn_valid(pfn))
1287 return NULL;
1288
1289 page = pfn_to_online_page(pfn);
1290 if (!page || page_zone(page) != zone)
1291 return NULL;
1292
1293 BUG_ON(PageHighMem(page));
1294
1295 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1296 return NULL;
1297
1298 if (PageOffline(page))
1299 return NULL;
1300
1301 if (PageReserved(page)
1302 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1303 return NULL;
1304
1305 if (page_is_guard(page))
1306 return NULL;
1307
1308 return page;
1309}
1310
1311/**
1312 * count_data_pages - Compute the total number of saveable non-highmem pages.
1313 */
1314static unsigned int count_data_pages(void)
1315{
1316 struct zone *zone;
1317 unsigned long pfn, max_zone_pfn;
1318 unsigned int n = 0;
1319
1320 for_each_populated_zone(zone) {
1321 if (is_highmem(zone))
1322 continue;
1323
1324 mark_free_pages(zone);
1325 max_zone_pfn = zone_end_pfn(zone);
1326 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1327 if (saveable_page(zone, pfn))
1328 n++;
1329 }
1330 return n;
1331}
1332
1333/*
1334 * This is needed, because copy_page and memcpy are not usable for copying
1335 * task structs.
1336 */
1337static inline void do_copy_page(long *dst, long *src)
1338{
1339 int n;
1340
1341 for (n = PAGE_SIZE / sizeof(long); n; n--)
1342 *dst++ = *src++;
1343}
1344
1345/**
1346 * safe_copy_page - Copy a page in a safe way.
1347 *
1348 * Check if the page we are going to copy is marked as present in the kernel
1349 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1350 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1351 * always returns 'true'.
1352 */
1353static void safe_copy_page(void *dst, struct page *s_page)
1354{
1355 if (kernel_page_present(s_page)) {
1356 do_copy_page(dst, page_address(s_page));
1357 } else {
1358 kernel_map_pages(s_page, 1, 1);
1359 do_copy_page(dst, page_address(s_page));
1360 kernel_map_pages(s_page, 1, 0);
1361 }
1362}
1363
1364#ifdef CONFIG_HIGHMEM
1365static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1366{
1367 return is_highmem(zone) ?
1368 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1369}
1370
1371static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1372{
1373 struct page *s_page, *d_page;
1374 void *src, *dst;
1375
1376 s_page = pfn_to_page(src_pfn);
1377 d_page = pfn_to_page(dst_pfn);
1378 if (PageHighMem(s_page)) {
1379 src = kmap_atomic(s_page);
1380 dst = kmap_atomic(d_page);
1381 do_copy_page(dst, src);
1382 kunmap_atomic(dst);
1383 kunmap_atomic(src);
1384 } else {
1385 if (PageHighMem(d_page)) {
1386 /*
1387 * The page pointed to by src may contain some kernel
1388 * data modified by kmap_atomic()
1389 */
1390 safe_copy_page(buffer, s_page);
1391 dst = kmap_atomic(d_page);
1392 copy_page(dst, buffer);
1393 kunmap_atomic(dst);
1394 } else {
1395 safe_copy_page(page_address(d_page), s_page);
1396 }
1397 }
1398}
1399#else
1400#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1401
1402static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1403{
1404 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1405 pfn_to_page(src_pfn));
1406}
1407#endif /* CONFIG_HIGHMEM */
1408
1409static void copy_data_pages(struct memory_bitmap *copy_bm,
1410 struct memory_bitmap *orig_bm)
1411{
1412 struct zone *zone;
1413 unsigned long pfn;
1414
1415 for_each_populated_zone(zone) {
1416 unsigned long max_zone_pfn;
1417
1418 mark_free_pages(zone);
1419 max_zone_pfn = zone_end_pfn(zone);
1420 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1421 if (page_is_saveable(zone, pfn))
1422 memory_bm_set_bit(orig_bm, pfn);
1423 }
1424 memory_bm_position_reset(orig_bm);
1425 memory_bm_position_reset(copy_bm);
1426 for(;;) {
1427 pfn = memory_bm_next_pfn(orig_bm);
1428 if (unlikely(pfn == BM_END_OF_MAP))
1429 break;
1430 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1431 }
1432}
1433
1434/* Total number of image pages */
1435static unsigned int nr_copy_pages;
1436/* Number of pages needed for saving the original pfns of the image pages */
1437static unsigned int nr_meta_pages;
1438/*
1439 * Numbers of normal and highmem page frames allocated for hibernation image
1440 * before suspending devices.
1441 */
1442static unsigned int alloc_normal, alloc_highmem;
1443/*
1444 * Memory bitmap used for marking saveable pages (during hibernation) or
1445 * hibernation image pages (during restore)
1446 */
1447static struct memory_bitmap orig_bm;
1448/*
1449 * Memory bitmap used during hibernation for marking allocated page frames that
1450 * will contain copies of saveable pages. During restore it is initially used
1451 * for marking hibernation image pages, but then the set bits from it are
1452 * duplicated in @orig_bm and it is released. On highmem systems it is next
1453 * used for marking "safe" highmem pages, but it has to be reinitialized for
1454 * this purpose.
1455 */
1456static struct memory_bitmap copy_bm;
1457
1458/**
1459 * swsusp_free - Free pages allocated for hibernation image.
1460 *
1461 * Image pages are alocated before snapshot creation, so they need to be
1462 * released after resume.
1463 */
1464void swsusp_free(void)
1465{
1466 unsigned long fb_pfn, fr_pfn;
1467
1468 if (!forbidden_pages_map || !free_pages_map)
1469 goto out;
1470
1471 memory_bm_position_reset(forbidden_pages_map);
1472 memory_bm_position_reset(free_pages_map);
1473
1474loop:
1475 fr_pfn = memory_bm_next_pfn(free_pages_map);
1476 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1477
1478 /*
1479 * Find the next bit set in both bitmaps. This is guaranteed to
1480 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1481 */
1482 do {
1483 if (fb_pfn < fr_pfn)
1484 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1485 if (fr_pfn < fb_pfn)
1486 fr_pfn = memory_bm_next_pfn(free_pages_map);
1487 } while (fb_pfn != fr_pfn);
1488
1489 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1490 struct page *page = pfn_to_page(fr_pfn);
1491
1492 memory_bm_clear_current(forbidden_pages_map);
1493 memory_bm_clear_current(free_pages_map);
1494 hibernate_restore_unprotect_page(page_address(page));
1495 __free_page(page);
1496 goto loop;
1497 }
1498
1499out:
1500 nr_copy_pages = 0;
1501 nr_meta_pages = 0;
1502 restore_pblist = NULL;
1503 buffer = NULL;
1504 alloc_normal = 0;
1505 alloc_highmem = 0;
1506 hibernate_restore_protection_end();
1507}
1508
1509/* Helper functions used for the shrinking of memory. */
1510
1511#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1512
1513/**
1514 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1515 * @nr_pages: Number of page frames to allocate.
1516 * @mask: GFP flags to use for the allocation.
1517 *
1518 * Return value: Number of page frames actually allocated
1519 */
1520static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1521{
1522 unsigned long nr_alloc = 0;
1523
1524 while (nr_pages > 0) {
1525 struct page *page;
1526
1527 page = alloc_image_page(mask);
1528 if (!page)
1529 break;
1530 memory_bm_set_bit(©_bm, page_to_pfn(page));
1531 if (PageHighMem(page))
1532 alloc_highmem++;
1533 else
1534 alloc_normal++;
1535 nr_pages--;
1536 nr_alloc++;
1537 }
1538
1539 return nr_alloc;
1540}
1541
1542static unsigned long preallocate_image_memory(unsigned long nr_pages,
1543 unsigned long avail_normal)
1544{
1545 unsigned long alloc;
1546
1547 if (avail_normal <= alloc_normal)
1548 return 0;
1549
1550 alloc = avail_normal - alloc_normal;
1551 if (nr_pages < alloc)
1552 alloc = nr_pages;
1553
1554 return preallocate_image_pages(alloc, GFP_IMAGE);
1555}
1556
1557#ifdef CONFIG_HIGHMEM
1558static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1559{
1560 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1561}
1562
1563/**
1564 * __fraction - Compute (an approximation of) x * (multiplier / base).
1565 */
1566static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1567{
1568 return div64_u64(x * multiplier, base);
1569}
1570
1571static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1572 unsigned long highmem,
1573 unsigned long total)
1574{
1575 unsigned long alloc = __fraction(nr_pages, highmem, total);
1576
1577 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1578}
1579#else /* CONFIG_HIGHMEM */
1580static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1581{
1582 return 0;
1583}
1584
1585static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1586 unsigned long highmem,
1587 unsigned long total)
1588{
1589 return 0;
1590}
1591#endif /* CONFIG_HIGHMEM */
1592
1593/**
1594 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1595 */
1596static unsigned long free_unnecessary_pages(void)
1597{
1598 unsigned long save, to_free_normal, to_free_highmem, free;
1599
1600 save = count_data_pages();
1601 if (alloc_normal >= save) {
1602 to_free_normal = alloc_normal - save;
1603 save = 0;
1604 } else {
1605 to_free_normal = 0;
1606 save -= alloc_normal;
1607 }
1608 save += count_highmem_pages();
1609 if (alloc_highmem >= save) {
1610 to_free_highmem = alloc_highmem - save;
1611 } else {
1612 to_free_highmem = 0;
1613 save -= alloc_highmem;
1614 if (to_free_normal > save)
1615 to_free_normal -= save;
1616 else
1617 to_free_normal = 0;
1618 }
1619 free = to_free_normal + to_free_highmem;
1620
1621 memory_bm_position_reset(©_bm);
1622
1623 while (to_free_normal > 0 || to_free_highmem > 0) {
1624 unsigned long pfn = memory_bm_next_pfn(©_bm);
1625 struct page *page = pfn_to_page(pfn);
1626
1627 if (PageHighMem(page)) {
1628 if (!to_free_highmem)
1629 continue;
1630 to_free_highmem--;
1631 alloc_highmem--;
1632 } else {
1633 if (!to_free_normal)
1634 continue;
1635 to_free_normal--;
1636 alloc_normal--;
1637 }
1638 memory_bm_clear_bit(©_bm, pfn);
1639 swsusp_unset_page_forbidden(page);
1640 swsusp_unset_page_free(page);
1641 __free_page(page);
1642 }
1643
1644 return free;
1645}
1646
1647/**
1648 * minimum_image_size - Estimate the minimum acceptable size of an image.
1649 * @saveable: Number of saveable pages in the system.
1650 *
1651 * We want to avoid attempting to free too much memory too hard, so estimate the
1652 * minimum acceptable size of a hibernation image to use as the lower limit for
1653 * preallocating memory.
1654 *
1655 * We assume that the minimum image size should be proportional to
1656 *
1657 * [number of saveable pages] - [number of pages that can be freed in theory]
1658 *
1659 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1660 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1661 */
1662static unsigned long minimum_image_size(unsigned long saveable)
1663{
1664 unsigned long size;
1665
1666 size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
1667 + global_node_page_state(NR_ACTIVE_ANON)
1668 + global_node_page_state(NR_INACTIVE_ANON)
1669 + global_node_page_state(NR_ACTIVE_FILE)
1670 + global_node_page_state(NR_INACTIVE_FILE);
1671
1672 return saveable <= size ? 0 : saveable - size;
1673}
1674
1675/**
1676 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1677 *
1678 * To create a hibernation image it is necessary to make a copy of every page
1679 * frame in use. We also need a number of page frames to be free during
1680 * hibernation for allocations made while saving the image and for device
1681 * drivers, in case they need to allocate memory from their hibernation
1682 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1683 * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1684 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1685 * total number of available page frames and allocate at least
1686 *
1687 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1688 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1689 *
1690 * of them, which corresponds to the maximum size of a hibernation image.
1691 *
1692 * If image_size is set below the number following from the above formula,
1693 * the preallocation of memory is continued until the total number of saveable
1694 * pages in the system is below the requested image size or the minimum
1695 * acceptable image size returned by minimum_image_size(), whichever is greater.
1696 */
1697int hibernate_preallocate_memory(void)
1698{
1699 struct zone *zone;
1700 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1701 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1702 ktime_t start, stop;
1703 int error;
1704
1705 pr_info("Preallocating image memory\n");
1706 start = ktime_get();
1707
1708 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1709 if (error) {
1710 pr_err("Cannot allocate original bitmap\n");
1711 goto err_out;
1712 }
1713
1714 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1715 if (error) {
1716 pr_err("Cannot allocate copy bitmap\n");
1717 goto err_out;
1718 }
1719
1720 alloc_normal = 0;
1721 alloc_highmem = 0;
1722
1723 /* Count the number of saveable data pages. */
1724 save_highmem = count_highmem_pages();
1725 saveable = count_data_pages();
1726
1727 /*
1728 * Compute the total number of page frames we can use (count) and the
1729 * number of pages needed for image metadata (size).
1730 */
1731 count = saveable;
1732 saveable += save_highmem;
1733 highmem = save_highmem;
1734 size = 0;
1735 for_each_populated_zone(zone) {
1736 size += snapshot_additional_pages(zone);
1737 if (is_highmem(zone))
1738 highmem += zone_page_state(zone, NR_FREE_PAGES);
1739 else
1740 count += zone_page_state(zone, NR_FREE_PAGES);
1741 }
1742 avail_normal = count;
1743 count += highmem;
1744 count -= totalreserve_pages;
1745
1746 /* Compute the maximum number of saveable pages to leave in memory. */
1747 max_size = (count - (size + PAGES_FOR_IO)) / 2
1748 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1749 /* Compute the desired number of image pages specified by image_size. */
1750 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1751 if (size > max_size)
1752 size = max_size;
1753 /*
1754 * If the desired number of image pages is at least as large as the
1755 * current number of saveable pages in memory, allocate page frames for
1756 * the image and we're done.
1757 */
1758 if (size >= saveable) {
1759 pages = preallocate_image_highmem(save_highmem);
1760 pages += preallocate_image_memory(saveable - pages, avail_normal);
1761 goto out;
1762 }
1763
1764 /* Estimate the minimum size of the image. */
1765 pages = minimum_image_size(saveable);
1766 /*
1767 * To avoid excessive pressure on the normal zone, leave room in it to
1768 * accommodate an image of the minimum size (unless it's already too
1769 * small, in which case don't preallocate pages from it at all).
1770 */
1771 if (avail_normal > pages)
1772 avail_normal -= pages;
1773 else
1774 avail_normal = 0;
1775 if (size < pages)
1776 size = min_t(unsigned long, pages, max_size);
1777
1778 /*
1779 * Let the memory management subsystem know that we're going to need a
1780 * large number of page frames to allocate and make it free some memory.
1781 * NOTE: If this is not done, performance will be hurt badly in some
1782 * test cases.
1783 */
1784 shrink_all_memory(saveable - size);
1785
1786 /*
1787 * The number of saveable pages in memory was too high, so apply some
1788 * pressure to decrease it. First, make room for the largest possible
1789 * image and fail if that doesn't work. Next, try to decrease the size
1790 * of the image as much as indicated by 'size' using allocations from
1791 * highmem and non-highmem zones separately.
1792 */
1793 pages_highmem = preallocate_image_highmem(highmem / 2);
1794 alloc = count - max_size;
1795 if (alloc > pages_highmem)
1796 alloc -= pages_highmem;
1797 else
1798 alloc = 0;
1799 pages = preallocate_image_memory(alloc, avail_normal);
1800 if (pages < alloc) {
1801 /* We have exhausted non-highmem pages, try highmem. */
1802 alloc -= pages;
1803 pages += pages_highmem;
1804 pages_highmem = preallocate_image_highmem(alloc);
1805 if (pages_highmem < alloc) {
1806 pr_err("Image allocation is %lu pages short\n",
1807 alloc - pages_highmem);
1808 goto err_out;
1809 }
1810 pages += pages_highmem;
1811 /*
1812 * size is the desired number of saveable pages to leave in
1813 * memory, so try to preallocate (all memory - size) pages.
1814 */
1815 alloc = (count - pages) - size;
1816 pages += preallocate_image_highmem(alloc);
1817 } else {
1818 /*
1819 * There are approximately max_size saveable pages at this point
1820 * and we want to reduce this number down to size.
1821 */
1822 alloc = max_size - size;
1823 size = preallocate_highmem_fraction(alloc, highmem, count);
1824 pages_highmem += size;
1825 alloc -= size;
1826 size = preallocate_image_memory(alloc, avail_normal);
1827 pages_highmem += preallocate_image_highmem(alloc - size);
1828 pages += pages_highmem + size;
1829 }
1830
1831 /*
1832 * We only need as many page frames for the image as there are saveable
1833 * pages in memory, but we have allocated more. Release the excessive
1834 * ones now.
1835 */
1836 pages -= free_unnecessary_pages();
1837
1838 out:
1839 stop = ktime_get();
1840 pr_info("Allocated %lu pages for snapshot\n", pages);
1841 swsusp_show_speed(start, stop, pages, "Allocated");
1842
1843 return 0;
1844
1845 err_out:
1846 swsusp_free();
1847 return -ENOMEM;
1848}
1849
1850#ifdef CONFIG_HIGHMEM
1851/**
1852 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1853 *
1854 * Compute the number of non-highmem pages that will be necessary for creating
1855 * copies of highmem pages.
1856 */
1857static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1858{
1859 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1860
1861 if (free_highmem >= nr_highmem)
1862 nr_highmem = 0;
1863 else
1864 nr_highmem -= free_highmem;
1865
1866 return nr_highmem;
1867}
1868#else
1869static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1870#endif /* CONFIG_HIGHMEM */
1871
1872/**
1873 * enough_free_mem - Check if there is enough free memory for the image.
1874 */
1875static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1876{
1877 struct zone *zone;
1878 unsigned int free = alloc_normal;
1879
1880 for_each_populated_zone(zone)
1881 if (!is_highmem(zone))
1882 free += zone_page_state(zone, NR_FREE_PAGES);
1883
1884 nr_pages += count_pages_for_highmem(nr_highmem);
1885 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1886 nr_pages, PAGES_FOR_IO, free);
1887
1888 return free > nr_pages + PAGES_FOR_IO;
1889}
1890
1891#ifdef CONFIG_HIGHMEM
1892/**
1893 * get_highmem_buffer - Allocate a buffer for highmem pages.
1894 *
1895 * If there are some highmem pages in the hibernation image, we may need a
1896 * buffer to copy them and/or load their data.
1897 */
1898static inline int get_highmem_buffer(int safe_needed)
1899{
1900 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1901 return buffer ? 0 : -ENOMEM;
1902}
1903
1904/**
1905 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1906 *
1907 * Try to allocate as many pages as needed, but if the number of free highmem
1908 * pages is less than that, allocate them all.
1909 */
1910static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1911 unsigned int nr_highmem)
1912{
1913 unsigned int to_alloc = count_free_highmem_pages();
1914
1915 if (to_alloc > nr_highmem)
1916 to_alloc = nr_highmem;
1917
1918 nr_highmem -= to_alloc;
1919 while (to_alloc-- > 0) {
1920 struct page *page;
1921
1922 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1923 memory_bm_set_bit(bm, page_to_pfn(page));
1924 }
1925 return nr_highmem;
1926}
1927#else
1928static inline int get_highmem_buffer(int safe_needed) { return 0; }
1929
1930static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1931 unsigned int n) { return 0; }
1932#endif /* CONFIG_HIGHMEM */
1933
1934/**
1935 * swsusp_alloc - Allocate memory for hibernation image.
1936 *
1937 * We first try to allocate as many highmem pages as there are
1938 * saveable highmem pages in the system. If that fails, we allocate
1939 * non-highmem pages for the copies of the remaining highmem ones.
1940 *
1941 * In this approach it is likely that the copies of highmem pages will
1942 * also be located in the high memory, because of the way in which
1943 * copy_data_pages() works.
1944 */
1945static int swsusp_alloc(struct memory_bitmap *copy_bm,
1946 unsigned int nr_pages, unsigned int nr_highmem)
1947{
1948 if (nr_highmem > 0) {
1949 if (get_highmem_buffer(PG_ANY))
1950 goto err_out;
1951 if (nr_highmem > alloc_highmem) {
1952 nr_highmem -= alloc_highmem;
1953 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1954 }
1955 }
1956 if (nr_pages > alloc_normal) {
1957 nr_pages -= alloc_normal;
1958 while (nr_pages-- > 0) {
1959 struct page *page;
1960
1961 page = alloc_image_page(GFP_ATOMIC);
1962 if (!page)
1963 goto err_out;
1964 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1965 }
1966 }
1967
1968 return 0;
1969
1970 err_out:
1971 swsusp_free();
1972 return -ENOMEM;
1973}
1974
1975asmlinkage __visible int swsusp_save(void)
1976{
1977 unsigned int nr_pages, nr_highmem;
1978
1979 pr_info("Creating image:\n");
1980
1981 drain_local_pages(NULL);
1982 nr_pages = count_data_pages();
1983 nr_highmem = count_highmem_pages();
1984 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
1985
1986 if (!enough_free_mem(nr_pages, nr_highmem)) {
1987 pr_err("Not enough free memory\n");
1988 return -ENOMEM;
1989 }
1990
1991 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
1992 pr_err("Memory allocation failed\n");
1993 return -ENOMEM;
1994 }
1995
1996 /*
1997 * During allocating of suspend pagedir, new cold pages may appear.
1998 * Kill them.
1999 */
2000 drain_local_pages(NULL);
2001 copy_data_pages(©_bm, &orig_bm);
2002
2003 /*
2004 * End of critical section. From now on, we can write to memory,
2005 * but we should not touch disk. This specially means we must _not_
2006 * touch swap space! Except we must write out our image of course.
2007 */
2008
2009 nr_pages += nr_highmem;
2010 nr_copy_pages = nr_pages;
2011 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2012
2013 pr_info("Image created (%d pages copied)\n", nr_pages);
2014
2015 return 0;
2016}
2017
2018#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2019static int init_header_complete(struct swsusp_info *info)
2020{
2021 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2022 info->version_code = LINUX_VERSION_CODE;
2023 return 0;
2024}
2025
2026static const char *check_image_kernel(struct swsusp_info *info)
2027{
2028 if (info->version_code != LINUX_VERSION_CODE)
2029 return "kernel version";
2030 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2031 return "system type";
2032 if (strcmp(info->uts.release,init_utsname()->release))
2033 return "kernel release";
2034 if (strcmp(info->uts.version,init_utsname()->version))
2035 return "version";
2036 if (strcmp(info->uts.machine,init_utsname()->machine))
2037 return "machine";
2038 return NULL;
2039}
2040#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2041
2042unsigned long snapshot_get_image_size(void)
2043{
2044 return nr_copy_pages + nr_meta_pages + 1;
2045}
2046
2047static int init_header(struct swsusp_info *info)
2048{
2049 memset(info, 0, sizeof(struct swsusp_info));
2050 info->num_physpages = get_num_physpages();
2051 info->image_pages = nr_copy_pages;
2052 info->pages = snapshot_get_image_size();
2053 info->size = info->pages;
2054 info->size <<= PAGE_SHIFT;
2055 return init_header_complete(info);
2056}
2057
2058/**
2059 * pack_pfns - Prepare PFNs for saving.
2060 * @bm: Memory bitmap.
2061 * @buf: Memory buffer to store the PFNs in.
2062 *
2063 * PFNs corresponding to set bits in @bm are stored in the area of memory
2064 * pointed to by @buf (1 page at a time).
2065 */
2066static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2067{
2068 int j;
2069
2070 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2071 buf[j] = memory_bm_next_pfn(bm);
2072 if (unlikely(buf[j] == BM_END_OF_MAP))
2073 break;
2074 }
2075}
2076
2077/**
2078 * snapshot_read_next - Get the address to read the next image page from.
2079 * @handle: Snapshot handle to be used for the reading.
2080 *
2081 * On the first call, @handle should point to a zeroed snapshot_handle
2082 * structure. The structure gets populated then and a pointer to it should be
2083 * passed to this function every next time.
2084 *
2085 * On success, the function returns a positive number. Then, the caller
2086 * is allowed to read up to the returned number of bytes from the memory
2087 * location computed by the data_of() macro.
2088 *
2089 * The function returns 0 to indicate the end of the data stream condition,
2090 * and negative numbers are returned on errors. If that happens, the structure
2091 * pointed to by @handle is not updated and should not be used any more.
2092 */
2093int snapshot_read_next(struct snapshot_handle *handle)
2094{
2095 if (handle->cur > nr_meta_pages + nr_copy_pages)
2096 return 0;
2097
2098 if (!buffer) {
2099 /* This makes the buffer be freed by swsusp_free() */
2100 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2101 if (!buffer)
2102 return -ENOMEM;
2103 }
2104 if (!handle->cur) {
2105 int error;
2106
2107 error = init_header((struct swsusp_info *)buffer);
2108 if (error)
2109 return error;
2110 handle->buffer = buffer;
2111 memory_bm_position_reset(&orig_bm);
2112 memory_bm_position_reset(©_bm);
2113 } else if (handle->cur <= nr_meta_pages) {
2114 clear_page(buffer);
2115 pack_pfns(buffer, &orig_bm);
2116 } else {
2117 struct page *page;
2118
2119 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2120 if (PageHighMem(page)) {
2121 /*
2122 * Highmem pages are copied to the buffer,
2123 * because we can't return with a kmapped
2124 * highmem page (we may not be called again).
2125 */
2126 void *kaddr;
2127
2128 kaddr = kmap_atomic(page);
2129 copy_page(buffer, kaddr);
2130 kunmap_atomic(kaddr);
2131 handle->buffer = buffer;
2132 } else {
2133 handle->buffer = page_address(page);
2134 }
2135 }
2136 handle->cur++;
2137 return PAGE_SIZE;
2138}
2139
2140static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2141 struct memory_bitmap *src)
2142{
2143 unsigned long pfn;
2144
2145 memory_bm_position_reset(src);
2146 pfn = memory_bm_next_pfn(src);
2147 while (pfn != BM_END_OF_MAP) {
2148 memory_bm_set_bit(dst, pfn);
2149 pfn = memory_bm_next_pfn(src);
2150 }
2151}
2152
2153/**
2154 * mark_unsafe_pages - Mark pages that were used before hibernation.
2155 *
2156 * Mark the pages that cannot be used for storing the image during restoration,
2157 * because they conflict with the pages that had been used before hibernation.
2158 */
2159static void mark_unsafe_pages(struct memory_bitmap *bm)
2160{
2161 unsigned long pfn;
2162
2163 /* Clear the "free"/"unsafe" bit for all PFNs */
2164 memory_bm_position_reset(free_pages_map);
2165 pfn = memory_bm_next_pfn(free_pages_map);
2166 while (pfn != BM_END_OF_MAP) {
2167 memory_bm_clear_current(free_pages_map);
2168 pfn = memory_bm_next_pfn(free_pages_map);
2169 }
2170
2171 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2172 duplicate_memory_bitmap(free_pages_map, bm);
2173
2174 allocated_unsafe_pages = 0;
2175}
2176
2177static int check_header(struct swsusp_info *info)
2178{
2179 const char *reason;
2180
2181 reason = check_image_kernel(info);
2182 if (!reason && info->num_physpages != get_num_physpages())
2183 reason = "memory size";
2184 if (reason) {
2185 pr_err("Image mismatch: %s\n", reason);
2186 return -EPERM;
2187 }
2188 return 0;
2189}
2190
2191/**
2192 * load header - Check the image header and copy the data from it.
2193 */
2194static int load_header(struct swsusp_info *info)
2195{
2196 int error;
2197
2198 restore_pblist = NULL;
2199 error = check_header(info);
2200 if (!error) {
2201 nr_copy_pages = info->image_pages;
2202 nr_meta_pages = info->pages - info->image_pages - 1;
2203 }
2204 return error;
2205}
2206
2207/**
2208 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2209 * @bm: Memory bitmap.
2210 * @buf: Area of memory containing the PFNs.
2211 *
2212 * For each element of the array pointed to by @buf (1 page at a time), set the
2213 * corresponding bit in @bm.
2214 */
2215static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2216{
2217 int j;
2218
2219 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2220 if (unlikely(buf[j] == BM_END_OF_MAP))
2221 break;
2222
2223 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2224 memory_bm_set_bit(bm, buf[j]);
2225 else
2226 return -EFAULT;
2227 }
2228
2229 return 0;
2230}
2231
2232#ifdef CONFIG_HIGHMEM
2233/*
2234 * struct highmem_pbe is used for creating the list of highmem pages that
2235 * should be restored atomically during the resume from disk, because the page
2236 * frames they have occupied before the suspend are in use.
2237 */
2238struct highmem_pbe {
2239 struct page *copy_page; /* data is here now */
2240 struct page *orig_page; /* data was here before the suspend */
2241 struct highmem_pbe *next;
2242};
2243
2244/*
2245 * List of highmem PBEs needed for restoring the highmem pages that were
2246 * allocated before the suspend and included in the suspend image, but have
2247 * also been allocated by the "resume" kernel, so their contents cannot be
2248 * written directly to their "original" page frames.
2249 */
2250static struct highmem_pbe *highmem_pblist;
2251
2252/**
2253 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2254 * @bm: Memory bitmap.
2255 *
2256 * The bits in @bm that correspond to image pages are assumed to be set.
2257 */
2258static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2259{
2260 unsigned long pfn;
2261 unsigned int cnt = 0;
2262
2263 memory_bm_position_reset(bm);
2264 pfn = memory_bm_next_pfn(bm);
2265 while (pfn != BM_END_OF_MAP) {
2266 if (PageHighMem(pfn_to_page(pfn)))
2267 cnt++;
2268
2269 pfn = memory_bm_next_pfn(bm);
2270 }
2271 return cnt;
2272}
2273
2274static unsigned int safe_highmem_pages;
2275
2276static struct memory_bitmap *safe_highmem_bm;
2277
2278/**
2279 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2280 * @bm: Pointer to an uninitialized memory bitmap structure.
2281 * @nr_highmem_p: Pointer to the number of highmem image pages.
2282 *
2283 * Try to allocate as many highmem pages as there are highmem image pages
2284 * (@nr_highmem_p points to the variable containing the number of highmem image
2285 * pages). The pages that are "safe" (ie. will not be overwritten when the
2286 * hibernation image is restored entirely) have the corresponding bits set in
2287 * @bm (it must be unitialized).
2288 *
2289 * NOTE: This function should not be called if there are no highmem image pages.
2290 */
2291static int prepare_highmem_image(struct memory_bitmap *bm,
2292 unsigned int *nr_highmem_p)
2293{
2294 unsigned int to_alloc;
2295
2296 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2297 return -ENOMEM;
2298
2299 if (get_highmem_buffer(PG_SAFE))
2300 return -ENOMEM;
2301
2302 to_alloc = count_free_highmem_pages();
2303 if (to_alloc > *nr_highmem_p)
2304 to_alloc = *nr_highmem_p;
2305 else
2306 *nr_highmem_p = to_alloc;
2307
2308 safe_highmem_pages = 0;
2309 while (to_alloc-- > 0) {
2310 struct page *page;
2311
2312 page = alloc_page(__GFP_HIGHMEM);
2313 if (!swsusp_page_is_free(page)) {
2314 /* The page is "safe", set its bit the bitmap */
2315 memory_bm_set_bit(bm, page_to_pfn(page));
2316 safe_highmem_pages++;
2317 }
2318 /* Mark the page as allocated */
2319 swsusp_set_page_forbidden(page);
2320 swsusp_set_page_free(page);
2321 }
2322 memory_bm_position_reset(bm);
2323 safe_highmem_bm = bm;
2324 return 0;
2325}
2326
2327static struct page *last_highmem_page;
2328
2329/**
2330 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2331 *
2332 * For a given highmem image page get a buffer that suspend_write_next() should
2333 * return to its caller to write to.
2334 *
2335 * If the page is to be saved to its "original" page frame or a copy of
2336 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2337 * the copy of the page is to be made in normal memory, so the address of
2338 * the copy is returned.
2339 *
2340 * If @buffer is returned, the caller of suspend_write_next() will write
2341 * the page's contents to @buffer, so they will have to be copied to the
2342 * right location on the next call to suspend_write_next() and it is done
2343 * with the help of copy_last_highmem_page(). For this purpose, if
2344 * @buffer is returned, @last_highmem_page is set to the page to which
2345 * the data will have to be copied from @buffer.
2346 */
2347static void *get_highmem_page_buffer(struct page *page,
2348 struct chain_allocator *ca)
2349{
2350 struct highmem_pbe *pbe;
2351 void *kaddr;
2352
2353 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2354 /*
2355 * We have allocated the "original" page frame and we can
2356 * use it directly to store the loaded page.
2357 */
2358 last_highmem_page = page;
2359 return buffer;
2360 }
2361 /*
2362 * The "original" page frame has not been allocated and we have to
2363 * use a "safe" page frame to store the loaded page.
2364 */
2365 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2366 if (!pbe) {
2367 swsusp_free();
2368 return ERR_PTR(-ENOMEM);
2369 }
2370 pbe->orig_page = page;
2371 if (safe_highmem_pages > 0) {
2372 struct page *tmp;
2373
2374 /* Copy of the page will be stored in high memory */
2375 kaddr = buffer;
2376 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2377 safe_highmem_pages--;
2378 last_highmem_page = tmp;
2379 pbe->copy_page = tmp;
2380 } else {
2381 /* Copy of the page will be stored in normal memory */
2382 kaddr = safe_pages_list;
2383 safe_pages_list = safe_pages_list->next;
2384 pbe->copy_page = virt_to_page(kaddr);
2385 }
2386 pbe->next = highmem_pblist;
2387 highmem_pblist = pbe;
2388 return kaddr;
2389}
2390
2391/**
2392 * copy_last_highmem_page - Copy most the most recent highmem image page.
2393 *
2394 * Copy the contents of a highmem image from @buffer, where the caller of
2395 * snapshot_write_next() has stored them, to the right location represented by
2396 * @last_highmem_page .
2397 */
2398static void copy_last_highmem_page(void)
2399{
2400 if (last_highmem_page) {
2401 void *dst;
2402
2403 dst = kmap_atomic(last_highmem_page);
2404 copy_page(dst, buffer);
2405 kunmap_atomic(dst);
2406 last_highmem_page = NULL;
2407 }
2408}
2409
2410static inline int last_highmem_page_copied(void)
2411{
2412 return !last_highmem_page;
2413}
2414
2415static inline void free_highmem_data(void)
2416{
2417 if (safe_highmem_bm)
2418 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2419
2420 if (buffer)
2421 free_image_page(buffer, PG_UNSAFE_CLEAR);
2422}
2423#else
2424static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2425
2426static inline int prepare_highmem_image(struct memory_bitmap *bm,
2427 unsigned int *nr_highmem_p) { return 0; }
2428
2429static inline void *get_highmem_page_buffer(struct page *page,
2430 struct chain_allocator *ca)
2431{
2432 return ERR_PTR(-EINVAL);
2433}
2434
2435static inline void copy_last_highmem_page(void) {}
2436static inline int last_highmem_page_copied(void) { return 1; }
2437static inline void free_highmem_data(void) {}
2438#endif /* CONFIG_HIGHMEM */
2439
2440#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2441
2442/**
2443 * prepare_image - Make room for loading hibernation image.
2444 * @new_bm: Unitialized memory bitmap structure.
2445 * @bm: Memory bitmap with unsafe pages marked.
2446 *
2447 * Use @bm to mark the pages that will be overwritten in the process of
2448 * restoring the system memory state from the suspend image ("unsafe" pages)
2449 * and allocate memory for the image.
2450 *
2451 * The idea is to allocate a new memory bitmap first and then allocate
2452 * as many pages as needed for image data, but without specifying what those
2453 * pages will be used for just yet. Instead, we mark them all as allocated and
2454 * create a lists of "safe" pages to be used later. On systems with high
2455 * memory a list of "safe" highmem pages is created too.
2456 */
2457static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2458{
2459 unsigned int nr_pages, nr_highmem;
2460 struct linked_page *lp;
2461 int error;
2462
2463 /* If there is no highmem, the buffer will not be necessary */
2464 free_image_page(buffer, PG_UNSAFE_CLEAR);
2465 buffer = NULL;
2466
2467 nr_highmem = count_highmem_image_pages(bm);
2468 mark_unsafe_pages(bm);
2469
2470 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2471 if (error)
2472 goto Free;
2473
2474 duplicate_memory_bitmap(new_bm, bm);
2475 memory_bm_free(bm, PG_UNSAFE_KEEP);
2476 if (nr_highmem > 0) {
2477 error = prepare_highmem_image(bm, &nr_highmem);
2478 if (error)
2479 goto Free;
2480 }
2481 /*
2482 * Reserve some safe pages for potential later use.
2483 *
2484 * NOTE: This way we make sure there will be enough safe pages for the
2485 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2486 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2487 *
2488 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2489 */
2490 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2491 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2492 while (nr_pages > 0) {
2493 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2494 if (!lp) {
2495 error = -ENOMEM;
2496 goto Free;
2497 }
2498 lp->next = safe_pages_list;
2499 safe_pages_list = lp;
2500 nr_pages--;
2501 }
2502 /* Preallocate memory for the image */
2503 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2504 while (nr_pages > 0) {
2505 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2506 if (!lp) {
2507 error = -ENOMEM;
2508 goto Free;
2509 }
2510 if (!swsusp_page_is_free(virt_to_page(lp))) {
2511 /* The page is "safe", add it to the list */
2512 lp->next = safe_pages_list;
2513 safe_pages_list = lp;
2514 }
2515 /* Mark the page as allocated */
2516 swsusp_set_page_forbidden(virt_to_page(lp));
2517 swsusp_set_page_free(virt_to_page(lp));
2518 nr_pages--;
2519 }
2520 return 0;
2521
2522 Free:
2523 swsusp_free();
2524 return error;
2525}
2526
2527/**
2528 * get_buffer - Get the address to store the next image data page.
2529 *
2530 * Get the address that snapshot_write_next() should return to its caller to
2531 * write to.
2532 */
2533static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2534{
2535 struct pbe *pbe;
2536 struct page *page;
2537 unsigned long pfn = memory_bm_next_pfn(bm);
2538
2539 if (pfn == BM_END_OF_MAP)
2540 return ERR_PTR(-EFAULT);
2541
2542 page = pfn_to_page(pfn);
2543 if (PageHighMem(page))
2544 return get_highmem_page_buffer(page, ca);
2545
2546 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2547 /*
2548 * We have allocated the "original" page frame and we can
2549 * use it directly to store the loaded page.
2550 */
2551 return page_address(page);
2552
2553 /*
2554 * The "original" page frame has not been allocated and we have to
2555 * use a "safe" page frame to store the loaded page.
2556 */
2557 pbe = chain_alloc(ca, sizeof(struct pbe));
2558 if (!pbe) {
2559 swsusp_free();
2560 return ERR_PTR(-ENOMEM);
2561 }
2562 pbe->orig_address = page_address(page);
2563 pbe->address = safe_pages_list;
2564 safe_pages_list = safe_pages_list->next;
2565 pbe->next = restore_pblist;
2566 restore_pblist = pbe;
2567 return pbe->address;
2568}
2569
2570/**
2571 * snapshot_write_next - Get the address to store the next image page.
2572 * @handle: Snapshot handle structure to guide the writing.
2573 *
2574 * On the first call, @handle should point to a zeroed snapshot_handle
2575 * structure. The structure gets populated then and a pointer to it should be
2576 * passed to this function every next time.
2577 *
2578 * On success, the function returns a positive number. Then, the caller
2579 * is allowed to write up to the returned number of bytes to the memory
2580 * location computed by the data_of() macro.
2581 *
2582 * The function returns 0 to indicate the "end of file" condition. Negative
2583 * numbers are returned on errors, in which cases the structure pointed to by
2584 * @handle is not updated and should not be used any more.
2585 */
2586int snapshot_write_next(struct snapshot_handle *handle)
2587{
2588 static struct chain_allocator ca;
2589 int error = 0;
2590
2591 /* Check if we have already loaded the entire image */
2592 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2593 return 0;
2594
2595 handle->sync_read = 1;
2596
2597 if (!handle->cur) {
2598 if (!buffer)
2599 /* This makes the buffer be freed by swsusp_free() */
2600 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2601
2602 if (!buffer)
2603 return -ENOMEM;
2604
2605 handle->buffer = buffer;
2606 } else if (handle->cur == 1) {
2607 error = load_header(buffer);
2608 if (error)
2609 return error;
2610
2611 safe_pages_list = NULL;
2612
2613 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2614 if (error)
2615 return error;
2616
2617 hibernate_restore_protection_begin();
2618 } else if (handle->cur <= nr_meta_pages + 1) {
2619 error = unpack_orig_pfns(buffer, ©_bm);
2620 if (error)
2621 return error;
2622
2623 if (handle->cur == nr_meta_pages + 1) {
2624 error = prepare_image(&orig_bm, ©_bm);
2625 if (error)
2626 return error;
2627
2628 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2629 memory_bm_position_reset(&orig_bm);
2630 restore_pblist = NULL;
2631 handle->buffer = get_buffer(&orig_bm, &ca);
2632 handle->sync_read = 0;
2633 if (IS_ERR(handle->buffer))
2634 return PTR_ERR(handle->buffer);
2635 }
2636 } else {
2637 copy_last_highmem_page();
2638 hibernate_restore_protect_page(handle->buffer);
2639 handle->buffer = get_buffer(&orig_bm, &ca);
2640 if (IS_ERR(handle->buffer))
2641 return PTR_ERR(handle->buffer);
2642 if (handle->buffer != buffer)
2643 handle->sync_read = 0;
2644 }
2645 handle->cur++;
2646 return PAGE_SIZE;
2647}
2648
2649/**
2650 * snapshot_write_finalize - Complete the loading of a hibernation image.
2651 *
2652 * Must be called after the last call to snapshot_write_next() in case the last
2653 * page in the image happens to be a highmem page and its contents should be
2654 * stored in highmem. Additionally, it recycles bitmap memory that's not
2655 * necessary any more.
2656 */
2657void snapshot_write_finalize(struct snapshot_handle *handle)
2658{
2659 copy_last_highmem_page();
2660 hibernate_restore_protect_page(handle->buffer);
2661 /* Do that only if we have loaded the image entirely */
2662 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2663 memory_bm_recycle(&orig_bm);
2664 free_highmem_data();
2665 }
2666}
2667
2668int snapshot_image_loaded(struct snapshot_handle *handle)
2669{
2670 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2671 handle->cur <= nr_meta_pages + nr_copy_pages);
2672}
2673
2674#ifdef CONFIG_HIGHMEM
2675/* Assumes that @buf is ready and points to a "safe" page */
2676static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2677 void *buf)
2678{
2679 void *kaddr1, *kaddr2;
2680
2681 kaddr1 = kmap_atomic(p1);
2682 kaddr2 = kmap_atomic(p2);
2683 copy_page(buf, kaddr1);
2684 copy_page(kaddr1, kaddr2);
2685 copy_page(kaddr2, buf);
2686 kunmap_atomic(kaddr2);
2687 kunmap_atomic(kaddr1);
2688}
2689
2690/**
2691 * restore_highmem - Put highmem image pages into their original locations.
2692 *
2693 * For each highmem page that was in use before hibernation and is included in
2694 * the image, and also has been allocated by the "restore" kernel, swap its
2695 * current contents with the previous (ie. "before hibernation") ones.
2696 *
2697 * If the restore eventually fails, we can call this function once again and
2698 * restore the highmem state as seen by the restore kernel.
2699 */
2700int restore_highmem(void)
2701{
2702 struct highmem_pbe *pbe = highmem_pblist;
2703 void *buf;
2704
2705 if (!pbe)
2706 return 0;
2707
2708 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2709 if (!buf)
2710 return -ENOMEM;
2711
2712 while (pbe) {
2713 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2714 pbe = pbe->next;
2715 }
2716 free_image_page(buf, PG_UNSAFE_CLEAR);
2717 return 0;
2718}
2719#endif /* CONFIG_HIGHMEM */
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/snapshot.c
4 *
5 * This file provides system snapshot/restore functionality for swsusp.
6 *
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 */
10
11#define pr_fmt(fmt) "PM: hibernation: " fmt
12
13#include <linux/version.h>
14#include <linux/module.h>
15#include <linux/mm.h>
16#include <linux/suspend.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/spinlock.h>
20#include <linux/kernel.h>
21#include <linux/pm.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/memblock.h>
25#include <linux/nmi.h>
26#include <linux/syscalls.h>
27#include <linux/console.h>
28#include <linux/highmem.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31#include <linux/compiler.h>
32#include <linux/ktime.h>
33#include <linux/set_memory.h>
34
35#include <linux/uaccess.h>
36#include <asm/mmu_context.h>
37#include <asm/tlbflush.h>
38#include <asm/io.h>
39
40#include "power.h"
41
42#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
43static bool hibernate_restore_protection;
44static bool hibernate_restore_protection_active;
45
46void enable_restore_image_protection(void)
47{
48 hibernate_restore_protection = true;
49}
50
51static inline void hibernate_restore_protection_begin(void)
52{
53 hibernate_restore_protection_active = hibernate_restore_protection;
54}
55
56static inline void hibernate_restore_protection_end(void)
57{
58 hibernate_restore_protection_active = false;
59}
60
61static inline void hibernate_restore_protect_page(void *page_address)
62{
63 if (hibernate_restore_protection_active)
64 set_memory_ro((unsigned long)page_address, 1);
65}
66
67static inline void hibernate_restore_unprotect_page(void *page_address)
68{
69 if (hibernate_restore_protection_active)
70 set_memory_rw((unsigned long)page_address, 1);
71}
72#else
73static inline void hibernate_restore_protection_begin(void) {}
74static inline void hibernate_restore_protection_end(void) {}
75static inline void hibernate_restore_protect_page(void *page_address) {}
76static inline void hibernate_restore_unprotect_page(void *page_address) {}
77#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
78
79
80/*
81 * The calls to set_direct_map_*() should not fail because remapping a page
82 * here means that we only update protection bits in an existing PTE.
83 * It is still worth to have a warning here if something changes and this
84 * will no longer be the case.
85 */
86static inline void hibernate_map_page(struct page *page)
87{
88 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
89 int ret = set_direct_map_default_noflush(page);
90
91 if (ret)
92 pr_warn_once("Failed to remap page\n");
93 } else {
94 debug_pagealloc_map_pages(page, 1);
95 }
96}
97
98static inline void hibernate_unmap_page(struct page *page)
99{
100 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
101 unsigned long addr = (unsigned long)page_address(page);
102 int ret = set_direct_map_invalid_noflush(page);
103
104 if (ret)
105 pr_warn_once("Failed to remap page\n");
106
107 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
108 } else {
109 debug_pagealloc_unmap_pages(page, 1);
110 }
111}
112
113static int swsusp_page_is_free(struct page *);
114static void swsusp_set_page_forbidden(struct page *);
115static void swsusp_unset_page_forbidden(struct page *);
116
117/*
118 * Number of bytes to reserve for memory allocations made by device drivers
119 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
120 * cause image creation to fail (tunable via /sys/power/reserved_size).
121 */
122unsigned long reserved_size;
123
124void __init hibernate_reserved_size_init(void)
125{
126 reserved_size = SPARE_PAGES * PAGE_SIZE;
127}
128
129/*
130 * Preferred image size in bytes (tunable via /sys/power/image_size).
131 * When it is set to N, swsusp will do its best to ensure the image
132 * size will not exceed N bytes, but if that is impossible, it will
133 * try to create the smallest image possible.
134 */
135unsigned long image_size;
136
137void __init hibernate_image_size_init(void)
138{
139 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
140}
141
142/*
143 * List of PBEs needed for restoring the pages that were allocated before
144 * the suspend and included in the suspend image, but have also been
145 * allocated by the "resume" kernel, so their contents cannot be written
146 * directly to their "original" page frames.
147 */
148struct pbe *restore_pblist;
149
150/* struct linked_page is used to build chains of pages */
151
152#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
153
154struct linked_page {
155 struct linked_page *next;
156 char data[LINKED_PAGE_DATA_SIZE];
157} __packed;
158
159/*
160 * List of "safe" pages (ie. pages that were not used by the image kernel
161 * before hibernation) that may be used as temporary storage for image kernel
162 * memory contents.
163 */
164static struct linked_page *safe_pages_list;
165
166/* Pointer to an auxiliary buffer (1 page) */
167static void *buffer;
168
169#define PG_ANY 0
170#define PG_SAFE 1
171#define PG_UNSAFE_CLEAR 1
172#define PG_UNSAFE_KEEP 0
173
174static unsigned int allocated_unsafe_pages;
175
176/**
177 * get_image_page - Allocate a page for a hibernation image.
178 * @gfp_mask: GFP mask for the allocation.
179 * @safe_needed: Get pages that were not used before hibernation (restore only)
180 *
181 * During image restoration, for storing the PBE list and the image data, we can
182 * only use memory pages that do not conflict with the pages used before
183 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
184 * using allocated_unsafe_pages.
185 *
186 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
187 * swsusp_free() can release it.
188 */
189static void *get_image_page(gfp_t gfp_mask, int safe_needed)
190{
191 void *res;
192
193 res = (void *)get_zeroed_page(gfp_mask);
194 if (safe_needed)
195 while (res && swsusp_page_is_free(virt_to_page(res))) {
196 /* The page is unsafe, mark it for swsusp_free() */
197 swsusp_set_page_forbidden(virt_to_page(res));
198 allocated_unsafe_pages++;
199 res = (void *)get_zeroed_page(gfp_mask);
200 }
201 if (res) {
202 swsusp_set_page_forbidden(virt_to_page(res));
203 swsusp_set_page_free(virt_to_page(res));
204 }
205 return res;
206}
207
208static void *__get_safe_page(gfp_t gfp_mask)
209{
210 if (safe_pages_list) {
211 void *ret = safe_pages_list;
212
213 safe_pages_list = safe_pages_list->next;
214 memset(ret, 0, PAGE_SIZE);
215 return ret;
216 }
217 return get_image_page(gfp_mask, PG_SAFE);
218}
219
220unsigned long get_safe_page(gfp_t gfp_mask)
221{
222 return (unsigned long)__get_safe_page(gfp_mask);
223}
224
225static struct page *alloc_image_page(gfp_t gfp_mask)
226{
227 struct page *page;
228
229 page = alloc_page(gfp_mask);
230 if (page) {
231 swsusp_set_page_forbidden(page);
232 swsusp_set_page_free(page);
233 }
234 return page;
235}
236
237static void recycle_safe_page(void *page_address)
238{
239 struct linked_page *lp = page_address;
240
241 lp->next = safe_pages_list;
242 safe_pages_list = lp;
243}
244
245/**
246 * free_image_page - Free a page allocated for hibernation image.
247 * @addr: Address of the page to free.
248 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
249 *
250 * The page to free should have been allocated by get_image_page() (page flags
251 * set by it are affected).
252 */
253static inline void free_image_page(void *addr, int clear_nosave_free)
254{
255 struct page *page;
256
257 BUG_ON(!virt_addr_valid(addr));
258
259 page = virt_to_page(addr);
260
261 swsusp_unset_page_forbidden(page);
262 if (clear_nosave_free)
263 swsusp_unset_page_free(page);
264
265 __free_page(page);
266}
267
268static inline void free_list_of_pages(struct linked_page *list,
269 int clear_page_nosave)
270{
271 while (list) {
272 struct linked_page *lp = list->next;
273
274 free_image_page(list, clear_page_nosave);
275 list = lp;
276 }
277}
278
279/*
280 * struct chain_allocator is used for allocating small objects out of
281 * a linked list of pages called 'the chain'.
282 *
283 * The chain grows each time when there is no room for a new object in
284 * the current page. The allocated objects cannot be freed individually.
285 * It is only possible to free them all at once, by freeing the entire
286 * chain.
287 *
288 * NOTE: The chain allocator may be inefficient if the allocated objects
289 * are not much smaller than PAGE_SIZE.
290 */
291struct chain_allocator {
292 struct linked_page *chain; /* the chain */
293 unsigned int used_space; /* total size of objects allocated out
294 of the current page */
295 gfp_t gfp_mask; /* mask for allocating pages */
296 int safe_needed; /* if set, only "safe" pages are allocated */
297};
298
299static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
300 int safe_needed)
301{
302 ca->chain = NULL;
303 ca->used_space = LINKED_PAGE_DATA_SIZE;
304 ca->gfp_mask = gfp_mask;
305 ca->safe_needed = safe_needed;
306}
307
308static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
309{
310 void *ret;
311
312 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
313 struct linked_page *lp;
314
315 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
316 get_image_page(ca->gfp_mask, PG_ANY);
317 if (!lp)
318 return NULL;
319
320 lp->next = ca->chain;
321 ca->chain = lp;
322 ca->used_space = 0;
323 }
324 ret = ca->chain->data + ca->used_space;
325 ca->used_space += size;
326 return ret;
327}
328
329/**
330 * Data types related to memory bitmaps.
331 *
332 * Memory bitmap is a structure consisting of many linked lists of
333 * objects. The main list's elements are of type struct zone_bitmap
334 * and each of them corresponds to one zone. For each zone bitmap
335 * object there is a list of objects of type struct bm_block that
336 * represent each blocks of bitmap in which information is stored.
337 *
338 * struct memory_bitmap contains a pointer to the main list of zone
339 * bitmap objects, a struct bm_position used for browsing the bitmap,
340 * and a pointer to the list of pages used for allocating all of the
341 * zone bitmap objects and bitmap block objects.
342 *
343 * NOTE: It has to be possible to lay out the bitmap in memory
344 * using only allocations of order 0. Additionally, the bitmap is
345 * designed to work with arbitrary number of zones (this is over the
346 * top for now, but let's avoid making unnecessary assumptions ;-).
347 *
348 * struct zone_bitmap contains a pointer to a list of bitmap block
349 * objects and a pointer to the bitmap block object that has been
350 * most recently used for setting bits. Additionally, it contains the
351 * PFNs that correspond to the start and end of the represented zone.
352 *
353 * struct bm_block contains a pointer to the memory page in which
354 * information is stored (in the form of a block of bitmap)
355 * It also contains the pfns that correspond to the start and end of
356 * the represented memory area.
357 *
358 * The memory bitmap is organized as a radix tree to guarantee fast random
359 * access to the bits. There is one radix tree for each zone (as returned
360 * from create_mem_extents).
361 *
362 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
363 * two linked lists for the nodes of the tree, one for the inner nodes and
364 * one for the leave nodes. The linked leave nodes are used for fast linear
365 * access of the memory bitmap.
366 *
367 * The struct rtree_node represents one node of the radix tree.
368 */
369
370#define BM_END_OF_MAP (~0UL)
371
372#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
373#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
374#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
375
376/*
377 * struct rtree_node is a wrapper struct to link the nodes
378 * of the rtree together for easy linear iteration over
379 * bits and easy freeing
380 */
381struct rtree_node {
382 struct list_head list;
383 unsigned long *data;
384};
385
386/*
387 * struct mem_zone_bm_rtree represents a bitmap used for one
388 * populated memory zone.
389 */
390struct mem_zone_bm_rtree {
391 struct list_head list; /* Link Zones together */
392 struct list_head nodes; /* Radix Tree inner nodes */
393 struct list_head leaves; /* Radix Tree leaves */
394 unsigned long start_pfn; /* Zone start page frame */
395 unsigned long end_pfn; /* Zone end page frame + 1 */
396 struct rtree_node *rtree; /* Radix Tree Root */
397 int levels; /* Number of Radix Tree Levels */
398 unsigned int blocks; /* Number of Bitmap Blocks */
399};
400
401/* strcut bm_position is used for browsing memory bitmaps */
402
403struct bm_position {
404 struct mem_zone_bm_rtree *zone;
405 struct rtree_node *node;
406 unsigned long node_pfn;
407 int node_bit;
408};
409
410struct memory_bitmap {
411 struct list_head zones;
412 struct linked_page *p_list; /* list of pages used to store zone
413 bitmap objects and bitmap block
414 objects */
415 struct bm_position cur; /* most recently used bit position */
416};
417
418/* Functions that operate on memory bitmaps */
419
420#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
421#if BITS_PER_LONG == 32
422#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
423#else
424#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
425#endif
426#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
427
428/**
429 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
430 *
431 * This function is used to allocate inner nodes as well as the
432 * leave nodes of the radix tree. It also adds the node to the
433 * corresponding linked list passed in by the *list parameter.
434 */
435static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
436 struct chain_allocator *ca,
437 struct list_head *list)
438{
439 struct rtree_node *node;
440
441 node = chain_alloc(ca, sizeof(struct rtree_node));
442 if (!node)
443 return NULL;
444
445 node->data = get_image_page(gfp_mask, safe_needed);
446 if (!node->data)
447 return NULL;
448
449 list_add_tail(&node->list, list);
450
451 return node;
452}
453
454/**
455 * add_rtree_block - Add a new leave node to the radix tree.
456 *
457 * The leave nodes need to be allocated in order to keep the leaves
458 * linked list in order. This is guaranteed by the zone->blocks
459 * counter.
460 */
461static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
462 int safe_needed, struct chain_allocator *ca)
463{
464 struct rtree_node *node, *block, **dst;
465 unsigned int levels_needed, block_nr;
466 int i;
467
468 block_nr = zone->blocks;
469 levels_needed = 0;
470
471 /* How many levels do we need for this block nr? */
472 while (block_nr) {
473 levels_needed += 1;
474 block_nr >>= BM_RTREE_LEVEL_SHIFT;
475 }
476
477 /* Make sure the rtree has enough levels */
478 for (i = zone->levels; i < levels_needed; i++) {
479 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
480 &zone->nodes);
481 if (!node)
482 return -ENOMEM;
483
484 node->data[0] = (unsigned long)zone->rtree;
485 zone->rtree = node;
486 zone->levels += 1;
487 }
488
489 /* Allocate new block */
490 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
491 if (!block)
492 return -ENOMEM;
493
494 /* Now walk the rtree to insert the block */
495 node = zone->rtree;
496 dst = &zone->rtree;
497 block_nr = zone->blocks;
498 for (i = zone->levels; i > 0; i--) {
499 int index;
500
501 if (!node) {
502 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
503 &zone->nodes);
504 if (!node)
505 return -ENOMEM;
506 *dst = node;
507 }
508
509 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
510 index &= BM_RTREE_LEVEL_MASK;
511 dst = (struct rtree_node **)&((*dst)->data[index]);
512 node = *dst;
513 }
514
515 zone->blocks += 1;
516 *dst = block;
517
518 return 0;
519}
520
521static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
522 int clear_nosave_free);
523
524/**
525 * create_zone_bm_rtree - Create a radix tree for one zone.
526 *
527 * Allocated the mem_zone_bm_rtree structure and initializes it.
528 * This function also allocated and builds the radix tree for the
529 * zone.
530 */
531static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
532 int safe_needed,
533 struct chain_allocator *ca,
534 unsigned long start,
535 unsigned long end)
536{
537 struct mem_zone_bm_rtree *zone;
538 unsigned int i, nr_blocks;
539 unsigned long pages;
540
541 pages = end - start;
542 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
543 if (!zone)
544 return NULL;
545
546 INIT_LIST_HEAD(&zone->nodes);
547 INIT_LIST_HEAD(&zone->leaves);
548 zone->start_pfn = start;
549 zone->end_pfn = end;
550 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
551
552 for (i = 0; i < nr_blocks; i++) {
553 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
554 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
555 return NULL;
556 }
557 }
558
559 return zone;
560}
561
562/**
563 * free_zone_bm_rtree - Free the memory of the radix tree.
564 *
565 * Free all node pages of the radix tree. The mem_zone_bm_rtree
566 * structure itself is not freed here nor are the rtree_node
567 * structs.
568 */
569static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
570 int clear_nosave_free)
571{
572 struct rtree_node *node;
573
574 list_for_each_entry(node, &zone->nodes, list)
575 free_image_page(node->data, clear_nosave_free);
576
577 list_for_each_entry(node, &zone->leaves, list)
578 free_image_page(node->data, clear_nosave_free);
579}
580
581static void memory_bm_position_reset(struct memory_bitmap *bm)
582{
583 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
584 list);
585 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
586 struct rtree_node, list);
587 bm->cur.node_pfn = 0;
588 bm->cur.node_bit = 0;
589}
590
591static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
592
593struct mem_extent {
594 struct list_head hook;
595 unsigned long start;
596 unsigned long end;
597};
598
599/**
600 * free_mem_extents - Free a list of memory extents.
601 * @list: List of extents to free.
602 */
603static void free_mem_extents(struct list_head *list)
604{
605 struct mem_extent *ext, *aux;
606
607 list_for_each_entry_safe(ext, aux, list, hook) {
608 list_del(&ext->hook);
609 kfree(ext);
610 }
611}
612
613/**
614 * create_mem_extents - Create a list of memory extents.
615 * @list: List to put the extents into.
616 * @gfp_mask: Mask to use for memory allocations.
617 *
618 * The extents represent contiguous ranges of PFNs.
619 */
620static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
621{
622 struct zone *zone;
623
624 INIT_LIST_HEAD(list);
625
626 for_each_populated_zone(zone) {
627 unsigned long zone_start, zone_end;
628 struct mem_extent *ext, *cur, *aux;
629
630 zone_start = zone->zone_start_pfn;
631 zone_end = zone_end_pfn(zone);
632
633 list_for_each_entry(ext, list, hook)
634 if (zone_start <= ext->end)
635 break;
636
637 if (&ext->hook == list || zone_end < ext->start) {
638 /* New extent is necessary */
639 struct mem_extent *new_ext;
640
641 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
642 if (!new_ext) {
643 free_mem_extents(list);
644 return -ENOMEM;
645 }
646 new_ext->start = zone_start;
647 new_ext->end = zone_end;
648 list_add_tail(&new_ext->hook, &ext->hook);
649 continue;
650 }
651
652 /* Merge this zone's range of PFNs with the existing one */
653 if (zone_start < ext->start)
654 ext->start = zone_start;
655 if (zone_end > ext->end)
656 ext->end = zone_end;
657
658 /* More merging may be possible */
659 cur = ext;
660 list_for_each_entry_safe_continue(cur, aux, list, hook) {
661 if (zone_end < cur->start)
662 break;
663 if (zone_end < cur->end)
664 ext->end = cur->end;
665 list_del(&cur->hook);
666 kfree(cur);
667 }
668 }
669
670 return 0;
671}
672
673/**
674 * memory_bm_create - Allocate memory for a memory bitmap.
675 */
676static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
677 int safe_needed)
678{
679 struct chain_allocator ca;
680 struct list_head mem_extents;
681 struct mem_extent *ext;
682 int error;
683
684 chain_init(&ca, gfp_mask, safe_needed);
685 INIT_LIST_HEAD(&bm->zones);
686
687 error = create_mem_extents(&mem_extents, gfp_mask);
688 if (error)
689 return error;
690
691 list_for_each_entry(ext, &mem_extents, hook) {
692 struct mem_zone_bm_rtree *zone;
693
694 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
695 ext->start, ext->end);
696 if (!zone) {
697 error = -ENOMEM;
698 goto Error;
699 }
700 list_add_tail(&zone->list, &bm->zones);
701 }
702
703 bm->p_list = ca.chain;
704 memory_bm_position_reset(bm);
705 Exit:
706 free_mem_extents(&mem_extents);
707 return error;
708
709 Error:
710 bm->p_list = ca.chain;
711 memory_bm_free(bm, PG_UNSAFE_CLEAR);
712 goto Exit;
713}
714
715/**
716 * memory_bm_free - Free memory occupied by the memory bitmap.
717 * @bm: Memory bitmap.
718 */
719static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
720{
721 struct mem_zone_bm_rtree *zone;
722
723 list_for_each_entry(zone, &bm->zones, list)
724 free_zone_bm_rtree(zone, clear_nosave_free);
725
726 free_list_of_pages(bm->p_list, clear_nosave_free);
727
728 INIT_LIST_HEAD(&bm->zones);
729}
730
731/**
732 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
733 *
734 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
735 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
736 *
737 * Walk the radix tree to find the page containing the bit that represents @pfn
738 * and return the position of the bit in @addr and @bit_nr.
739 */
740static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
741 void **addr, unsigned int *bit_nr)
742{
743 struct mem_zone_bm_rtree *curr, *zone;
744 struct rtree_node *node;
745 int i, block_nr;
746
747 zone = bm->cur.zone;
748
749 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
750 goto zone_found;
751
752 zone = NULL;
753
754 /* Find the right zone */
755 list_for_each_entry(curr, &bm->zones, list) {
756 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
757 zone = curr;
758 break;
759 }
760 }
761
762 if (!zone)
763 return -EFAULT;
764
765zone_found:
766 /*
767 * We have found the zone. Now walk the radix tree to find the leaf node
768 * for our PFN.
769 */
770
771 /*
772 * If the zone we wish to scan is the current zone and the
773 * pfn falls into the current node then we do not need to walk
774 * the tree.
775 */
776 node = bm->cur.node;
777 if (zone == bm->cur.zone &&
778 ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
779 goto node_found;
780
781 node = zone->rtree;
782 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
783
784 for (i = zone->levels; i > 0; i--) {
785 int index;
786
787 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
788 index &= BM_RTREE_LEVEL_MASK;
789 BUG_ON(node->data[index] == 0);
790 node = (struct rtree_node *)node->data[index];
791 }
792
793node_found:
794 /* Update last position */
795 bm->cur.zone = zone;
796 bm->cur.node = node;
797 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
798
799 /* Set return values */
800 *addr = node->data;
801 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
802
803 return 0;
804}
805
806static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
807{
808 void *addr;
809 unsigned int bit;
810 int error;
811
812 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
813 BUG_ON(error);
814 set_bit(bit, addr);
815}
816
817static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
818{
819 void *addr;
820 unsigned int bit;
821 int error;
822
823 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
824 if (!error)
825 set_bit(bit, addr);
826
827 return error;
828}
829
830static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
831{
832 void *addr;
833 unsigned int bit;
834 int error;
835
836 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
837 BUG_ON(error);
838 clear_bit(bit, addr);
839}
840
841static void memory_bm_clear_current(struct memory_bitmap *bm)
842{
843 int bit;
844
845 bit = max(bm->cur.node_bit - 1, 0);
846 clear_bit(bit, bm->cur.node->data);
847}
848
849static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
850{
851 void *addr;
852 unsigned int bit;
853 int error;
854
855 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
856 BUG_ON(error);
857 return test_bit(bit, addr);
858}
859
860static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
861{
862 void *addr;
863 unsigned int bit;
864
865 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
866}
867
868/*
869 * rtree_next_node - Jump to the next leaf node.
870 *
871 * Set the position to the beginning of the next node in the
872 * memory bitmap. This is either the next node in the current
873 * zone's radix tree or the first node in the radix tree of the
874 * next zone.
875 *
876 * Return true if there is a next node, false otherwise.
877 */
878static bool rtree_next_node(struct memory_bitmap *bm)
879{
880 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
881 bm->cur.node = list_entry(bm->cur.node->list.next,
882 struct rtree_node, list);
883 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
884 bm->cur.node_bit = 0;
885 touch_softlockup_watchdog();
886 return true;
887 }
888
889 /* No more nodes, goto next zone */
890 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
891 bm->cur.zone = list_entry(bm->cur.zone->list.next,
892 struct mem_zone_bm_rtree, list);
893 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
894 struct rtree_node, list);
895 bm->cur.node_pfn = 0;
896 bm->cur.node_bit = 0;
897 return true;
898 }
899
900 /* No more zones */
901 return false;
902}
903
904/**
905 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
906 * @bm: Memory bitmap.
907 *
908 * Starting from the last returned position this function searches for the next
909 * set bit in @bm and returns the PFN represented by it. If no more bits are
910 * set, BM_END_OF_MAP is returned.
911 *
912 * It is required to run memory_bm_position_reset() before the first call to
913 * this function for the given memory bitmap.
914 */
915static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
916{
917 unsigned long bits, pfn, pages;
918 int bit;
919
920 do {
921 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
922 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
923 bit = find_next_bit(bm->cur.node->data, bits,
924 bm->cur.node_bit);
925 if (bit < bits) {
926 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
927 bm->cur.node_bit = bit + 1;
928 return pfn;
929 }
930 } while (rtree_next_node(bm));
931
932 return BM_END_OF_MAP;
933}
934
935/*
936 * This structure represents a range of page frames the contents of which
937 * should not be saved during hibernation.
938 */
939struct nosave_region {
940 struct list_head list;
941 unsigned long start_pfn;
942 unsigned long end_pfn;
943};
944
945static LIST_HEAD(nosave_regions);
946
947static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
948{
949 struct rtree_node *node;
950
951 list_for_each_entry(node, &zone->nodes, list)
952 recycle_safe_page(node->data);
953
954 list_for_each_entry(node, &zone->leaves, list)
955 recycle_safe_page(node->data);
956}
957
958static void memory_bm_recycle(struct memory_bitmap *bm)
959{
960 struct mem_zone_bm_rtree *zone;
961 struct linked_page *p_list;
962
963 list_for_each_entry(zone, &bm->zones, list)
964 recycle_zone_bm_rtree(zone);
965
966 p_list = bm->p_list;
967 while (p_list) {
968 struct linked_page *lp = p_list;
969
970 p_list = lp->next;
971 recycle_safe_page(lp);
972 }
973}
974
975/**
976 * register_nosave_region - Register a region of unsaveable memory.
977 *
978 * Register a range of page frames the contents of which should not be saved
979 * during hibernation (to be used in the early initialization code).
980 */
981void __init __register_nosave_region(unsigned long start_pfn,
982 unsigned long end_pfn, int use_kmalloc)
983{
984 struct nosave_region *region;
985
986 if (start_pfn >= end_pfn)
987 return;
988
989 if (!list_empty(&nosave_regions)) {
990 /* Try to extend the previous region (they should be sorted) */
991 region = list_entry(nosave_regions.prev,
992 struct nosave_region, list);
993 if (region->end_pfn == start_pfn) {
994 region->end_pfn = end_pfn;
995 goto Report;
996 }
997 }
998 if (use_kmalloc) {
999 /* During init, this shouldn't fail */
1000 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
1001 BUG_ON(!region);
1002 } else {
1003 /* This allocation cannot fail */
1004 region = memblock_alloc(sizeof(struct nosave_region),
1005 SMP_CACHE_BYTES);
1006 if (!region)
1007 panic("%s: Failed to allocate %zu bytes\n", __func__,
1008 sizeof(struct nosave_region));
1009 }
1010 region->start_pfn = start_pfn;
1011 region->end_pfn = end_pfn;
1012 list_add_tail(®ion->list, &nosave_regions);
1013 Report:
1014 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
1015 (unsigned long long) start_pfn << PAGE_SHIFT,
1016 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
1017}
1018
1019/*
1020 * Set bits in this map correspond to the page frames the contents of which
1021 * should not be saved during the suspend.
1022 */
1023static struct memory_bitmap *forbidden_pages_map;
1024
1025/* Set bits in this map correspond to free page frames. */
1026static struct memory_bitmap *free_pages_map;
1027
1028/*
1029 * Each page frame allocated for creating the image is marked by setting the
1030 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
1031 */
1032
1033void swsusp_set_page_free(struct page *page)
1034{
1035 if (free_pages_map)
1036 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
1037}
1038
1039static int swsusp_page_is_free(struct page *page)
1040{
1041 return free_pages_map ?
1042 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1043}
1044
1045void swsusp_unset_page_free(struct page *page)
1046{
1047 if (free_pages_map)
1048 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1049}
1050
1051static void swsusp_set_page_forbidden(struct page *page)
1052{
1053 if (forbidden_pages_map)
1054 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1055}
1056
1057int swsusp_page_is_forbidden(struct page *page)
1058{
1059 return forbidden_pages_map ?
1060 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1061}
1062
1063static void swsusp_unset_page_forbidden(struct page *page)
1064{
1065 if (forbidden_pages_map)
1066 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1067}
1068
1069/**
1070 * mark_nosave_pages - Mark pages that should not be saved.
1071 * @bm: Memory bitmap.
1072 *
1073 * Set the bits in @bm that correspond to the page frames the contents of which
1074 * should not be saved.
1075 */
1076static void mark_nosave_pages(struct memory_bitmap *bm)
1077{
1078 struct nosave_region *region;
1079
1080 if (list_empty(&nosave_regions))
1081 return;
1082
1083 list_for_each_entry(region, &nosave_regions, list) {
1084 unsigned long pfn;
1085
1086 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1087 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1088 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1089 - 1);
1090
1091 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1092 if (pfn_valid(pfn)) {
1093 /*
1094 * It is safe to ignore the result of
1095 * mem_bm_set_bit_check() here, since we won't
1096 * touch the PFNs for which the error is
1097 * returned anyway.
1098 */
1099 mem_bm_set_bit_check(bm, pfn);
1100 }
1101 }
1102}
1103
1104/**
1105 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1106 *
1107 * Create bitmaps needed for marking page frames that should not be saved and
1108 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1109 * only modified if everything goes well, because we don't want the bits to be
1110 * touched before both bitmaps are set up.
1111 */
1112int create_basic_memory_bitmaps(void)
1113{
1114 struct memory_bitmap *bm1, *bm2;
1115 int error = 0;
1116
1117 if (forbidden_pages_map && free_pages_map)
1118 return 0;
1119 else
1120 BUG_ON(forbidden_pages_map || free_pages_map);
1121
1122 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1123 if (!bm1)
1124 return -ENOMEM;
1125
1126 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1127 if (error)
1128 goto Free_first_object;
1129
1130 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1131 if (!bm2)
1132 goto Free_first_bitmap;
1133
1134 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1135 if (error)
1136 goto Free_second_object;
1137
1138 forbidden_pages_map = bm1;
1139 free_pages_map = bm2;
1140 mark_nosave_pages(forbidden_pages_map);
1141
1142 pr_debug("Basic memory bitmaps created\n");
1143
1144 return 0;
1145
1146 Free_second_object:
1147 kfree(bm2);
1148 Free_first_bitmap:
1149 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1150 Free_first_object:
1151 kfree(bm1);
1152 return -ENOMEM;
1153}
1154
1155/**
1156 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1157 *
1158 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1159 * auxiliary pointers are necessary so that the bitmaps themselves are not
1160 * referred to while they are being freed.
1161 */
1162void free_basic_memory_bitmaps(void)
1163{
1164 struct memory_bitmap *bm1, *bm2;
1165
1166 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1167 return;
1168
1169 bm1 = forbidden_pages_map;
1170 bm2 = free_pages_map;
1171 forbidden_pages_map = NULL;
1172 free_pages_map = NULL;
1173 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1174 kfree(bm1);
1175 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1176 kfree(bm2);
1177
1178 pr_debug("Basic memory bitmaps freed\n");
1179}
1180
1181static void clear_or_poison_free_page(struct page *page)
1182{
1183 if (page_poisoning_enabled_static())
1184 __kernel_poison_pages(page, 1);
1185 else if (want_init_on_free())
1186 clear_highpage(page);
1187}
1188
1189void clear_or_poison_free_pages(void)
1190{
1191 struct memory_bitmap *bm = free_pages_map;
1192 unsigned long pfn;
1193
1194 if (WARN_ON(!(free_pages_map)))
1195 return;
1196
1197 if (page_poisoning_enabled() || want_init_on_free()) {
1198 memory_bm_position_reset(bm);
1199 pfn = memory_bm_next_pfn(bm);
1200 while (pfn != BM_END_OF_MAP) {
1201 if (pfn_valid(pfn))
1202 clear_or_poison_free_page(pfn_to_page(pfn));
1203
1204 pfn = memory_bm_next_pfn(bm);
1205 }
1206 memory_bm_position_reset(bm);
1207 pr_info("free pages cleared after restore\n");
1208 }
1209}
1210
1211/**
1212 * snapshot_additional_pages - Estimate the number of extra pages needed.
1213 * @zone: Memory zone to carry out the computation for.
1214 *
1215 * Estimate the number of additional pages needed for setting up a hibernation
1216 * image data structures for @zone (usually, the returned value is greater than
1217 * the exact number).
1218 */
1219unsigned int snapshot_additional_pages(struct zone *zone)
1220{
1221 unsigned int rtree, nodes;
1222
1223 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1224 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1225 LINKED_PAGE_DATA_SIZE);
1226 while (nodes > 1) {
1227 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1228 rtree += nodes;
1229 }
1230
1231 return 2 * rtree;
1232}
1233
1234#ifdef CONFIG_HIGHMEM
1235/**
1236 * count_free_highmem_pages - Compute the total number of free highmem pages.
1237 *
1238 * The returned number is system-wide.
1239 */
1240static unsigned int count_free_highmem_pages(void)
1241{
1242 struct zone *zone;
1243 unsigned int cnt = 0;
1244
1245 for_each_populated_zone(zone)
1246 if (is_highmem(zone))
1247 cnt += zone_page_state(zone, NR_FREE_PAGES);
1248
1249 return cnt;
1250}
1251
1252/**
1253 * saveable_highmem_page - Check if a highmem page is saveable.
1254 *
1255 * Determine whether a highmem page should be included in a hibernation image.
1256 *
1257 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1258 * and it isn't part of a free chunk of pages.
1259 */
1260static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1261{
1262 struct page *page;
1263
1264 if (!pfn_valid(pfn))
1265 return NULL;
1266
1267 page = pfn_to_online_page(pfn);
1268 if (!page || page_zone(page) != zone)
1269 return NULL;
1270
1271 BUG_ON(!PageHighMem(page));
1272
1273 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1274 return NULL;
1275
1276 if (PageReserved(page) || PageOffline(page))
1277 return NULL;
1278
1279 if (page_is_guard(page))
1280 return NULL;
1281
1282 return page;
1283}
1284
1285/**
1286 * count_highmem_pages - Compute the total number of saveable highmem pages.
1287 */
1288static unsigned int count_highmem_pages(void)
1289{
1290 struct zone *zone;
1291 unsigned int n = 0;
1292
1293 for_each_populated_zone(zone) {
1294 unsigned long pfn, max_zone_pfn;
1295
1296 if (!is_highmem(zone))
1297 continue;
1298
1299 mark_free_pages(zone);
1300 max_zone_pfn = zone_end_pfn(zone);
1301 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1302 if (saveable_highmem_page(zone, pfn))
1303 n++;
1304 }
1305 return n;
1306}
1307#else
1308static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1309{
1310 return NULL;
1311}
1312#endif /* CONFIG_HIGHMEM */
1313
1314/**
1315 * saveable_page - Check if the given page is saveable.
1316 *
1317 * Determine whether a non-highmem page should be included in a hibernation
1318 * image.
1319 *
1320 * We should save the page if it isn't Nosave, and is not in the range
1321 * of pages statically defined as 'unsaveable', and it isn't part of
1322 * a free chunk of pages.
1323 */
1324static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1325{
1326 struct page *page;
1327
1328 if (!pfn_valid(pfn))
1329 return NULL;
1330
1331 page = pfn_to_online_page(pfn);
1332 if (!page || page_zone(page) != zone)
1333 return NULL;
1334
1335 BUG_ON(PageHighMem(page));
1336
1337 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1338 return NULL;
1339
1340 if (PageOffline(page))
1341 return NULL;
1342
1343 if (PageReserved(page)
1344 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1345 return NULL;
1346
1347 if (page_is_guard(page))
1348 return NULL;
1349
1350 return page;
1351}
1352
1353/**
1354 * count_data_pages - Compute the total number of saveable non-highmem pages.
1355 */
1356static unsigned int count_data_pages(void)
1357{
1358 struct zone *zone;
1359 unsigned long pfn, max_zone_pfn;
1360 unsigned int n = 0;
1361
1362 for_each_populated_zone(zone) {
1363 if (is_highmem(zone))
1364 continue;
1365
1366 mark_free_pages(zone);
1367 max_zone_pfn = zone_end_pfn(zone);
1368 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1369 if (saveable_page(zone, pfn))
1370 n++;
1371 }
1372 return n;
1373}
1374
1375/*
1376 * This is needed, because copy_page and memcpy are not usable for copying
1377 * task structs.
1378 */
1379static inline void do_copy_page(long *dst, long *src)
1380{
1381 int n;
1382
1383 for (n = PAGE_SIZE / sizeof(long); n; n--)
1384 *dst++ = *src++;
1385}
1386
1387/**
1388 * safe_copy_page - Copy a page in a safe way.
1389 *
1390 * Check if the page we are going to copy is marked as present in the kernel
1391 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1392 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1393 * always returns 'true'.
1394 */
1395static void safe_copy_page(void *dst, struct page *s_page)
1396{
1397 if (kernel_page_present(s_page)) {
1398 do_copy_page(dst, page_address(s_page));
1399 } else {
1400 hibernate_map_page(s_page);
1401 do_copy_page(dst, page_address(s_page));
1402 hibernate_unmap_page(s_page);
1403 }
1404}
1405
1406#ifdef CONFIG_HIGHMEM
1407static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1408{
1409 return is_highmem(zone) ?
1410 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1411}
1412
1413static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1414{
1415 struct page *s_page, *d_page;
1416 void *src, *dst;
1417
1418 s_page = pfn_to_page(src_pfn);
1419 d_page = pfn_to_page(dst_pfn);
1420 if (PageHighMem(s_page)) {
1421 src = kmap_atomic(s_page);
1422 dst = kmap_atomic(d_page);
1423 do_copy_page(dst, src);
1424 kunmap_atomic(dst);
1425 kunmap_atomic(src);
1426 } else {
1427 if (PageHighMem(d_page)) {
1428 /*
1429 * The page pointed to by src may contain some kernel
1430 * data modified by kmap_atomic()
1431 */
1432 safe_copy_page(buffer, s_page);
1433 dst = kmap_atomic(d_page);
1434 copy_page(dst, buffer);
1435 kunmap_atomic(dst);
1436 } else {
1437 safe_copy_page(page_address(d_page), s_page);
1438 }
1439 }
1440}
1441#else
1442#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1443
1444static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1445{
1446 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1447 pfn_to_page(src_pfn));
1448}
1449#endif /* CONFIG_HIGHMEM */
1450
1451static void copy_data_pages(struct memory_bitmap *copy_bm,
1452 struct memory_bitmap *orig_bm)
1453{
1454 struct zone *zone;
1455 unsigned long pfn;
1456
1457 for_each_populated_zone(zone) {
1458 unsigned long max_zone_pfn;
1459
1460 mark_free_pages(zone);
1461 max_zone_pfn = zone_end_pfn(zone);
1462 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1463 if (page_is_saveable(zone, pfn))
1464 memory_bm_set_bit(orig_bm, pfn);
1465 }
1466 memory_bm_position_reset(orig_bm);
1467 memory_bm_position_reset(copy_bm);
1468 for(;;) {
1469 pfn = memory_bm_next_pfn(orig_bm);
1470 if (unlikely(pfn == BM_END_OF_MAP))
1471 break;
1472 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1473 }
1474}
1475
1476/* Total number of image pages */
1477static unsigned int nr_copy_pages;
1478/* Number of pages needed for saving the original pfns of the image pages */
1479static unsigned int nr_meta_pages;
1480/*
1481 * Numbers of normal and highmem page frames allocated for hibernation image
1482 * before suspending devices.
1483 */
1484static unsigned int alloc_normal, alloc_highmem;
1485/*
1486 * Memory bitmap used for marking saveable pages (during hibernation) or
1487 * hibernation image pages (during restore)
1488 */
1489static struct memory_bitmap orig_bm;
1490/*
1491 * Memory bitmap used during hibernation for marking allocated page frames that
1492 * will contain copies of saveable pages. During restore it is initially used
1493 * for marking hibernation image pages, but then the set bits from it are
1494 * duplicated in @orig_bm and it is released. On highmem systems it is next
1495 * used for marking "safe" highmem pages, but it has to be reinitialized for
1496 * this purpose.
1497 */
1498static struct memory_bitmap copy_bm;
1499
1500/**
1501 * swsusp_free - Free pages allocated for hibernation image.
1502 *
1503 * Image pages are allocated before snapshot creation, so they need to be
1504 * released after resume.
1505 */
1506void swsusp_free(void)
1507{
1508 unsigned long fb_pfn, fr_pfn;
1509
1510 if (!forbidden_pages_map || !free_pages_map)
1511 goto out;
1512
1513 memory_bm_position_reset(forbidden_pages_map);
1514 memory_bm_position_reset(free_pages_map);
1515
1516loop:
1517 fr_pfn = memory_bm_next_pfn(free_pages_map);
1518 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1519
1520 /*
1521 * Find the next bit set in both bitmaps. This is guaranteed to
1522 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1523 */
1524 do {
1525 if (fb_pfn < fr_pfn)
1526 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1527 if (fr_pfn < fb_pfn)
1528 fr_pfn = memory_bm_next_pfn(free_pages_map);
1529 } while (fb_pfn != fr_pfn);
1530
1531 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1532 struct page *page = pfn_to_page(fr_pfn);
1533
1534 memory_bm_clear_current(forbidden_pages_map);
1535 memory_bm_clear_current(free_pages_map);
1536 hibernate_restore_unprotect_page(page_address(page));
1537 __free_page(page);
1538 goto loop;
1539 }
1540
1541out:
1542 nr_copy_pages = 0;
1543 nr_meta_pages = 0;
1544 restore_pblist = NULL;
1545 buffer = NULL;
1546 alloc_normal = 0;
1547 alloc_highmem = 0;
1548 hibernate_restore_protection_end();
1549}
1550
1551/* Helper functions used for the shrinking of memory. */
1552
1553#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1554
1555/**
1556 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1557 * @nr_pages: Number of page frames to allocate.
1558 * @mask: GFP flags to use for the allocation.
1559 *
1560 * Return value: Number of page frames actually allocated
1561 */
1562static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1563{
1564 unsigned long nr_alloc = 0;
1565
1566 while (nr_pages > 0) {
1567 struct page *page;
1568
1569 page = alloc_image_page(mask);
1570 if (!page)
1571 break;
1572 memory_bm_set_bit(©_bm, page_to_pfn(page));
1573 if (PageHighMem(page))
1574 alloc_highmem++;
1575 else
1576 alloc_normal++;
1577 nr_pages--;
1578 nr_alloc++;
1579 }
1580
1581 return nr_alloc;
1582}
1583
1584static unsigned long preallocate_image_memory(unsigned long nr_pages,
1585 unsigned long avail_normal)
1586{
1587 unsigned long alloc;
1588
1589 if (avail_normal <= alloc_normal)
1590 return 0;
1591
1592 alloc = avail_normal - alloc_normal;
1593 if (nr_pages < alloc)
1594 alloc = nr_pages;
1595
1596 return preallocate_image_pages(alloc, GFP_IMAGE);
1597}
1598
1599#ifdef CONFIG_HIGHMEM
1600static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1601{
1602 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1603}
1604
1605/**
1606 * __fraction - Compute (an approximation of) x * (multiplier / base).
1607 */
1608static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1609{
1610 return div64_u64(x * multiplier, base);
1611}
1612
1613static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1614 unsigned long highmem,
1615 unsigned long total)
1616{
1617 unsigned long alloc = __fraction(nr_pages, highmem, total);
1618
1619 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1620}
1621#else /* CONFIG_HIGHMEM */
1622static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1623{
1624 return 0;
1625}
1626
1627static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1628 unsigned long highmem,
1629 unsigned long total)
1630{
1631 return 0;
1632}
1633#endif /* CONFIG_HIGHMEM */
1634
1635/**
1636 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1637 */
1638static unsigned long free_unnecessary_pages(void)
1639{
1640 unsigned long save, to_free_normal, to_free_highmem, free;
1641
1642 save = count_data_pages();
1643 if (alloc_normal >= save) {
1644 to_free_normal = alloc_normal - save;
1645 save = 0;
1646 } else {
1647 to_free_normal = 0;
1648 save -= alloc_normal;
1649 }
1650 save += count_highmem_pages();
1651 if (alloc_highmem >= save) {
1652 to_free_highmem = alloc_highmem - save;
1653 } else {
1654 to_free_highmem = 0;
1655 save -= alloc_highmem;
1656 if (to_free_normal > save)
1657 to_free_normal -= save;
1658 else
1659 to_free_normal = 0;
1660 }
1661 free = to_free_normal + to_free_highmem;
1662
1663 memory_bm_position_reset(©_bm);
1664
1665 while (to_free_normal > 0 || to_free_highmem > 0) {
1666 unsigned long pfn = memory_bm_next_pfn(©_bm);
1667 struct page *page = pfn_to_page(pfn);
1668
1669 if (PageHighMem(page)) {
1670 if (!to_free_highmem)
1671 continue;
1672 to_free_highmem--;
1673 alloc_highmem--;
1674 } else {
1675 if (!to_free_normal)
1676 continue;
1677 to_free_normal--;
1678 alloc_normal--;
1679 }
1680 memory_bm_clear_bit(©_bm, pfn);
1681 swsusp_unset_page_forbidden(page);
1682 swsusp_unset_page_free(page);
1683 __free_page(page);
1684 }
1685
1686 return free;
1687}
1688
1689/**
1690 * minimum_image_size - Estimate the minimum acceptable size of an image.
1691 * @saveable: Number of saveable pages in the system.
1692 *
1693 * We want to avoid attempting to free too much memory too hard, so estimate the
1694 * minimum acceptable size of a hibernation image to use as the lower limit for
1695 * preallocating memory.
1696 *
1697 * We assume that the minimum image size should be proportional to
1698 *
1699 * [number of saveable pages] - [number of pages that can be freed in theory]
1700 *
1701 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1702 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1703 */
1704static unsigned long minimum_image_size(unsigned long saveable)
1705{
1706 unsigned long size;
1707
1708 size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
1709 + global_node_page_state(NR_ACTIVE_ANON)
1710 + global_node_page_state(NR_INACTIVE_ANON)
1711 + global_node_page_state(NR_ACTIVE_FILE)
1712 + global_node_page_state(NR_INACTIVE_FILE);
1713
1714 return saveable <= size ? 0 : saveable - size;
1715}
1716
1717/**
1718 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1719 *
1720 * To create a hibernation image it is necessary to make a copy of every page
1721 * frame in use. We also need a number of page frames to be free during
1722 * hibernation for allocations made while saving the image and for device
1723 * drivers, in case they need to allocate memory from their hibernation
1724 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1725 * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1726 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1727 * total number of available page frames and allocate at least
1728 *
1729 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1730 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1731 *
1732 * of them, which corresponds to the maximum size of a hibernation image.
1733 *
1734 * If image_size is set below the number following from the above formula,
1735 * the preallocation of memory is continued until the total number of saveable
1736 * pages in the system is below the requested image size or the minimum
1737 * acceptable image size returned by minimum_image_size(), whichever is greater.
1738 */
1739int hibernate_preallocate_memory(void)
1740{
1741 struct zone *zone;
1742 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1743 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1744 ktime_t start, stop;
1745 int error;
1746
1747 pr_info("Preallocating image memory\n");
1748 start = ktime_get();
1749
1750 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1751 if (error) {
1752 pr_err("Cannot allocate original bitmap\n");
1753 goto err_out;
1754 }
1755
1756 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1757 if (error) {
1758 pr_err("Cannot allocate copy bitmap\n");
1759 goto err_out;
1760 }
1761
1762 alloc_normal = 0;
1763 alloc_highmem = 0;
1764
1765 /* Count the number of saveable data pages. */
1766 save_highmem = count_highmem_pages();
1767 saveable = count_data_pages();
1768
1769 /*
1770 * Compute the total number of page frames we can use (count) and the
1771 * number of pages needed for image metadata (size).
1772 */
1773 count = saveable;
1774 saveable += save_highmem;
1775 highmem = save_highmem;
1776 size = 0;
1777 for_each_populated_zone(zone) {
1778 size += snapshot_additional_pages(zone);
1779 if (is_highmem(zone))
1780 highmem += zone_page_state(zone, NR_FREE_PAGES);
1781 else
1782 count += zone_page_state(zone, NR_FREE_PAGES);
1783 }
1784 avail_normal = count;
1785 count += highmem;
1786 count -= totalreserve_pages;
1787
1788 /* Compute the maximum number of saveable pages to leave in memory. */
1789 max_size = (count - (size + PAGES_FOR_IO)) / 2
1790 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1791 /* Compute the desired number of image pages specified by image_size. */
1792 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1793 if (size > max_size)
1794 size = max_size;
1795 /*
1796 * If the desired number of image pages is at least as large as the
1797 * current number of saveable pages in memory, allocate page frames for
1798 * the image and we're done.
1799 */
1800 if (size >= saveable) {
1801 pages = preallocate_image_highmem(save_highmem);
1802 pages += preallocate_image_memory(saveable - pages, avail_normal);
1803 goto out;
1804 }
1805
1806 /* Estimate the minimum size of the image. */
1807 pages = minimum_image_size(saveable);
1808 /*
1809 * To avoid excessive pressure on the normal zone, leave room in it to
1810 * accommodate an image of the minimum size (unless it's already too
1811 * small, in which case don't preallocate pages from it at all).
1812 */
1813 if (avail_normal > pages)
1814 avail_normal -= pages;
1815 else
1816 avail_normal = 0;
1817 if (size < pages)
1818 size = min_t(unsigned long, pages, max_size);
1819
1820 /*
1821 * Let the memory management subsystem know that we're going to need a
1822 * large number of page frames to allocate and make it free some memory.
1823 * NOTE: If this is not done, performance will be hurt badly in some
1824 * test cases.
1825 */
1826 shrink_all_memory(saveable - size);
1827
1828 /*
1829 * The number of saveable pages in memory was too high, so apply some
1830 * pressure to decrease it. First, make room for the largest possible
1831 * image and fail if that doesn't work. Next, try to decrease the size
1832 * of the image as much as indicated by 'size' using allocations from
1833 * highmem and non-highmem zones separately.
1834 */
1835 pages_highmem = preallocate_image_highmem(highmem / 2);
1836 alloc = count - max_size;
1837 if (alloc > pages_highmem)
1838 alloc -= pages_highmem;
1839 else
1840 alloc = 0;
1841 pages = preallocate_image_memory(alloc, avail_normal);
1842 if (pages < alloc) {
1843 /* We have exhausted non-highmem pages, try highmem. */
1844 alloc -= pages;
1845 pages += pages_highmem;
1846 pages_highmem = preallocate_image_highmem(alloc);
1847 if (pages_highmem < alloc) {
1848 pr_err("Image allocation is %lu pages short\n",
1849 alloc - pages_highmem);
1850 goto err_out;
1851 }
1852 pages += pages_highmem;
1853 /*
1854 * size is the desired number of saveable pages to leave in
1855 * memory, so try to preallocate (all memory - size) pages.
1856 */
1857 alloc = (count - pages) - size;
1858 pages += preallocate_image_highmem(alloc);
1859 } else {
1860 /*
1861 * There are approximately max_size saveable pages at this point
1862 * and we want to reduce this number down to size.
1863 */
1864 alloc = max_size - size;
1865 size = preallocate_highmem_fraction(alloc, highmem, count);
1866 pages_highmem += size;
1867 alloc -= size;
1868 size = preallocate_image_memory(alloc, avail_normal);
1869 pages_highmem += preallocate_image_highmem(alloc - size);
1870 pages += pages_highmem + size;
1871 }
1872
1873 /*
1874 * We only need as many page frames for the image as there are saveable
1875 * pages in memory, but we have allocated more. Release the excessive
1876 * ones now.
1877 */
1878 pages -= free_unnecessary_pages();
1879
1880 out:
1881 stop = ktime_get();
1882 pr_info("Allocated %lu pages for snapshot\n", pages);
1883 swsusp_show_speed(start, stop, pages, "Allocated");
1884
1885 return 0;
1886
1887 err_out:
1888 swsusp_free();
1889 return -ENOMEM;
1890}
1891
1892#ifdef CONFIG_HIGHMEM
1893/**
1894 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1895 *
1896 * Compute the number of non-highmem pages that will be necessary for creating
1897 * copies of highmem pages.
1898 */
1899static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1900{
1901 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1902
1903 if (free_highmem >= nr_highmem)
1904 nr_highmem = 0;
1905 else
1906 nr_highmem -= free_highmem;
1907
1908 return nr_highmem;
1909}
1910#else
1911static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1912#endif /* CONFIG_HIGHMEM */
1913
1914/**
1915 * enough_free_mem - Check if there is enough free memory for the image.
1916 */
1917static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1918{
1919 struct zone *zone;
1920 unsigned int free = alloc_normal;
1921
1922 for_each_populated_zone(zone)
1923 if (!is_highmem(zone))
1924 free += zone_page_state(zone, NR_FREE_PAGES);
1925
1926 nr_pages += count_pages_for_highmem(nr_highmem);
1927 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1928 nr_pages, PAGES_FOR_IO, free);
1929
1930 return free > nr_pages + PAGES_FOR_IO;
1931}
1932
1933#ifdef CONFIG_HIGHMEM
1934/**
1935 * get_highmem_buffer - Allocate a buffer for highmem pages.
1936 *
1937 * If there are some highmem pages in the hibernation image, we may need a
1938 * buffer to copy them and/or load their data.
1939 */
1940static inline int get_highmem_buffer(int safe_needed)
1941{
1942 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1943 return buffer ? 0 : -ENOMEM;
1944}
1945
1946/**
1947 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1948 *
1949 * Try to allocate as many pages as needed, but if the number of free highmem
1950 * pages is less than that, allocate them all.
1951 */
1952static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1953 unsigned int nr_highmem)
1954{
1955 unsigned int to_alloc = count_free_highmem_pages();
1956
1957 if (to_alloc > nr_highmem)
1958 to_alloc = nr_highmem;
1959
1960 nr_highmem -= to_alloc;
1961 while (to_alloc-- > 0) {
1962 struct page *page;
1963
1964 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1965 memory_bm_set_bit(bm, page_to_pfn(page));
1966 }
1967 return nr_highmem;
1968}
1969#else
1970static inline int get_highmem_buffer(int safe_needed) { return 0; }
1971
1972static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1973 unsigned int n) { return 0; }
1974#endif /* CONFIG_HIGHMEM */
1975
1976/**
1977 * swsusp_alloc - Allocate memory for hibernation image.
1978 *
1979 * We first try to allocate as many highmem pages as there are
1980 * saveable highmem pages in the system. If that fails, we allocate
1981 * non-highmem pages for the copies of the remaining highmem ones.
1982 *
1983 * In this approach it is likely that the copies of highmem pages will
1984 * also be located in the high memory, because of the way in which
1985 * copy_data_pages() works.
1986 */
1987static int swsusp_alloc(struct memory_bitmap *copy_bm,
1988 unsigned int nr_pages, unsigned int nr_highmem)
1989{
1990 if (nr_highmem > 0) {
1991 if (get_highmem_buffer(PG_ANY))
1992 goto err_out;
1993 if (nr_highmem > alloc_highmem) {
1994 nr_highmem -= alloc_highmem;
1995 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1996 }
1997 }
1998 if (nr_pages > alloc_normal) {
1999 nr_pages -= alloc_normal;
2000 while (nr_pages-- > 0) {
2001 struct page *page;
2002
2003 page = alloc_image_page(GFP_ATOMIC);
2004 if (!page)
2005 goto err_out;
2006 memory_bm_set_bit(copy_bm, page_to_pfn(page));
2007 }
2008 }
2009
2010 return 0;
2011
2012 err_out:
2013 swsusp_free();
2014 return -ENOMEM;
2015}
2016
2017asmlinkage __visible int swsusp_save(void)
2018{
2019 unsigned int nr_pages, nr_highmem;
2020
2021 pr_info("Creating image:\n");
2022
2023 drain_local_pages(NULL);
2024 nr_pages = count_data_pages();
2025 nr_highmem = count_highmem_pages();
2026 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
2027
2028 if (!enough_free_mem(nr_pages, nr_highmem)) {
2029 pr_err("Not enough free memory\n");
2030 return -ENOMEM;
2031 }
2032
2033 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
2034 pr_err("Memory allocation failed\n");
2035 return -ENOMEM;
2036 }
2037
2038 /*
2039 * During allocating of suspend pagedir, new cold pages may appear.
2040 * Kill them.
2041 */
2042 drain_local_pages(NULL);
2043 copy_data_pages(©_bm, &orig_bm);
2044
2045 /*
2046 * End of critical section. From now on, we can write to memory,
2047 * but we should not touch disk. This specially means we must _not_
2048 * touch swap space! Except we must write out our image of course.
2049 */
2050
2051 nr_pages += nr_highmem;
2052 nr_copy_pages = nr_pages;
2053 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2054
2055 pr_info("Image created (%d pages copied)\n", nr_pages);
2056
2057 return 0;
2058}
2059
2060#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2061static int init_header_complete(struct swsusp_info *info)
2062{
2063 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2064 info->version_code = LINUX_VERSION_CODE;
2065 return 0;
2066}
2067
2068static const char *check_image_kernel(struct swsusp_info *info)
2069{
2070 if (info->version_code != LINUX_VERSION_CODE)
2071 return "kernel version";
2072 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2073 return "system type";
2074 if (strcmp(info->uts.release,init_utsname()->release))
2075 return "kernel release";
2076 if (strcmp(info->uts.version,init_utsname()->version))
2077 return "version";
2078 if (strcmp(info->uts.machine,init_utsname()->machine))
2079 return "machine";
2080 return NULL;
2081}
2082#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2083
2084unsigned long snapshot_get_image_size(void)
2085{
2086 return nr_copy_pages + nr_meta_pages + 1;
2087}
2088
2089static int init_header(struct swsusp_info *info)
2090{
2091 memset(info, 0, sizeof(struct swsusp_info));
2092 info->num_physpages = get_num_physpages();
2093 info->image_pages = nr_copy_pages;
2094 info->pages = snapshot_get_image_size();
2095 info->size = info->pages;
2096 info->size <<= PAGE_SHIFT;
2097 return init_header_complete(info);
2098}
2099
2100/**
2101 * pack_pfns - Prepare PFNs for saving.
2102 * @bm: Memory bitmap.
2103 * @buf: Memory buffer to store the PFNs in.
2104 *
2105 * PFNs corresponding to set bits in @bm are stored in the area of memory
2106 * pointed to by @buf (1 page at a time).
2107 */
2108static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2109{
2110 int j;
2111
2112 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2113 buf[j] = memory_bm_next_pfn(bm);
2114 if (unlikely(buf[j] == BM_END_OF_MAP))
2115 break;
2116 }
2117}
2118
2119/**
2120 * snapshot_read_next - Get the address to read the next image page from.
2121 * @handle: Snapshot handle to be used for the reading.
2122 *
2123 * On the first call, @handle should point to a zeroed snapshot_handle
2124 * structure. The structure gets populated then and a pointer to it should be
2125 * passed to this function every next time.
2126 *
2127 * On success, the function returns a positive number. Then, the caller
2128 * is allowed to read up to the returned number of bytes from the memory
2129 * location computed by the data_of() macro.
2130 *
2131 * The function returns 0 to indicate the end of the data stream condition,
2132 * and negative numbers are returned on errors. If that happens, the structure
2133 * pointed to by @handle is not updated and should not be used any more.
2134 */
2135int snapshot_read_next(struct snapshot_handle *handle)
2136{
2137 if (handle->cur > nr_meta_pages + nr_copy_pages)
2138 return 0;
2139
2140 if (!buffer) {
2141 /* This makes the buffer be freed by swsusp_free() */
2142 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2143 if (!buffer)
2144 return -ENOMEM;
2145 }
2146 if (!handle->cur) {
2147 int error;
2148
2149 error = init_header((struct swsusp_info *)buffer);
2150 if (error)
2151 return error;
2152 handle->buffer = buffer;
2153 memory_bm_position_reset(&orig_bm);
2154 memory_bm_position_reset(©_bm);
2155 } else if (handle->cur <= nr_meta_pages) {
2156 clear_page(buffer);
2157 pack_pfns(buffer, &orig_bm);
2158 } else {
2159 struct page *page;
2160
2161 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2162 if (PageHighMem(page)) {
2163 /*
2164 * Highmem pages are copied to the buffer,
2165 * because we can't return with a kmapped
2166 * highmem page (we may not be called again).
2167 */
2168 void *kaddr;
2169
2170 kaddr = kmap_atomic(page);
2171 copy_page(buffer, kaddr);
2172 kunmap_atomic(kaddr);
2173 handle->buffer = buffer;
2174 } else {
2175 handle->buffer = page_address(page);
2176 }
2177 }
2178 handle->cur++;
2179 return PAGE_SIZE;
2180}
2181
2182static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2183 struct memory_bitmap *src)
2184{
2185 unsigned long pfn;
2186
2187 memory_bm_position_reset(src);
2188 pfn = memory_bm_next_pfn(src);
2189 while (pfn != BM_END_OF_MAP) {
2190 memory_bm_set_bit(dst, pfn);
2191 pfn = memory_bm_next_pfn(src);
2192 }
2193}
2194
2195/**
2196 * mark_unsafe_pages - Mark pages that were used before hibernation.
2197 *
2198 * Mark the pages that cannot be used for storing the image during restoration,
2199 * because they conflict with the pages that had been used before hibernation.
2200 */
2201static void mark_unsafe_pages(struct memory_bitmap *bm)
2202{
2203 unsigned long pfn;
2204
2205 /* Clear the "free"/"unsafe" bit for all PFNs */
2206 memory_bm_position_reset(free_pages_map);
2207 pfn = memory_bm_next_pfn(free_pages_map);
2208 while (pfn != BM_END_OF_MAP) {
2209 memory_bm_clear_current(free_pages_map);
2210 pfn = memory_bm_next_pfn(free_pages_map);
2211 }
2212
2213 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2214 duplicate_memory_bitmap(free_pages_map, bm);
2215
2216 allocated_unsafe_pages = 0;
2217}
2218
2219static int check_header(struct swsusp_info *info)
2220{
2221 const char *reason;
2222
2223 reason = check_image_kernel(info);
2224 if (!reason && info->num_physpages != get_num_physpages())
2225 reason = "memory size";
2226 if (reason) {
2227 pr_err("Image mismatch: %s\n", reason);
2228 return -EPERM;
2229 }
2230 return 0;
2231}
2232
2233/**
2234 * load header - Check the image header and copy the data from it.
2235 */
2236static int load_header(struct swsusp_info *info)
2237{
2238 int error;
2239
2240 restore_pblist = NULL;
2241 error = check_header(info);
2242 if (!error) {
2243 nr_copy_pages = info->image_pages;
2244 nr_meta_pages = info->pages - info->image_pages - 1;
2245 }
2246 return error;
2247}
2248
2249/**
2250 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2251 * @bm: Memory bitmap.
2252 * @buf: Area of memory containing the PFNs.
2253 *
2254 * For each element of the array pointed to by @buf (1 page at a time), set the
2255 * corresponding bit in @bm.
2256 */
2257static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2258{
2259 int j;
2260
2261 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2262 if (unlikely(buf[j] == BM_END_OF_MAP))
2263 break;
2264
2265 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2266 memory_bm_set_bit(bm, buf[j]);
2267 else
2268 return -EFAULT;
2269 }
2270
2271 return 0;
2272}
2273
2274#ifdef CONFIG_HIGHMEM
2275/*
2276 * struct highmem_pbe is used for creating the list of highmem pages that
2277 * should be restored atomically during the resume from disk, because the page
2278 * frames they have occupied before the suspend are in use.
2279 */
2280struct highmem_pbe {
2281 struct page *copy_page; /* data is here now */
2282 struct page *orig_page; /* data was here before the suspend */
2283 struct highmem_pbe *next;
2284};
2285
2286/*
2287 * List of highmem PBEs needed for restoring the highmem pages that were
2288 * allocated before the suspend and included in the suspend image, but have
2289 * also been allocated by the "resume" kernel, so their contents cannot be
2290 * written directly to their "original" page frames.
2291 */
2292static struct highmem_pbe *highmem_pblist;
2293
2294/**
2295 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2296 * @bm: Memory bitmap.
2297 *
2298 * The bits in @bm that correspond to image pages are assumed to be set.
2299 */
2300static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2301{
2302 unsigned long pfn;
2303 unsigned int cnt = 0;
2304
2305 memory_bm_position_reset(bm);
2306 pfn = memory_bm_next_pfn(bm);
2307 while (pfn != BM_END_OF_MAP) {
2308 if (PageHighMem(pfn_to_page(pfn)))
2309 cnt++;
2310
2311 pfn = memory_bm_next_pfn(bm);
2312 }
2313 return cnt;
2314}
2315
2316static unsigned int safe_highmem_pages;
2317
2318static struct memory_bitmap *safe_highmem_bm;
2319
2320/**
2321 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2322 * @bm: Pointer to an uninitialized memory bitmap structure.
2323 * @nr_highmem_p: Pointer to the number of highmem image pages.
2324 *
2325 * Try to allocate as many highmem pages as there are highmem image pages
2326 * (@nr_highmem_p points to the variable containing the number of highmem image
2327 * pages). The pages that are "safe" (ie. will not be overwritten when the
2328 * hibernation image is restored entirely) have the corresponding bits set in
2329 * @bm (it must be uninitialized).
2330 *
2331 * NOTE: This function should not be called if there are no highmem image pages.
2332 */
2333static int prepare_highmem_image(struct memory_bitmap *bm,
2334 unsigned int *nr_highmem_p)
2335{
2336 unsigned int to_alloc;
2337
2338 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2339 return -ENOMEM;
2340
2341 if (get_highmem_buffer(PG_SAFE))
2342 return -ENOMEM;
2343
2344 to_alloc = count_free_highmem_pages();
2345 if (to_alloc > *nr_highmem_p)
2346 to_alloc = *nr_highmem_p;
2347 else
2348 *nr_highmem_p = to_alloc;
2349
2350 safe_highmem_pages = 0;
2351 while (to_alloc-- > 0) {
2352 struct page *page;
2353
2354 page = alloc_page(__GFP_HIGHMEM);
2355 if (!swsusp_page_is_free(page)) {
2356 /* The page is "safe", set its bit the bitmap */
2357 memory_bm_set_bit(bm, page_to_pfn(page));
2358 safe_highmem_pages++;
2359 }
2360 /* Mark the page as allocated */
2361 swsusp_set_page_forbidden(page);
2362 swsusp_set_page_free(page);
2363 }
2364 memory_bm_position_reset(bm);
2365 safe_highmem_bm = bm;
2366 return 0;
2367}
2368
2369static struct page *last_highmem_page;
2370
2371/**
2372 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2373 *
2374 * For a given highmem image page get a buffer that suspend_write_next() should
2375 * return to its caller to write to.
2376 *
2377 * If the page is to be saved to its "original" page frame or a copy of
2378 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2379 * the copy of the page is to be made in normal memory, so the address of
2380 * the copy is returned.
2381 *
2382 * If @buffer is returned, the caller of suspend_write_next() will write
2383 * the page's contents to @buffer, so they will have to be copied to the
2384 * right location on the next call to suspend_write_next() and it is done
2385 * with the help of copy_last_highmem_page(). For this purpose, if
2386 * @buffer is returned, @last_highmem_page is set to the page to which
2387 * the data will have to be copied from @buffer.
2388 */
2389static void *get_highmem_page_buffer(struct page *page,
2390 struct chain_allocator *ca)
2391{
2392 struct highmem_pbe *pbe;
2393 void *kaddr;
2394
2395 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2396 /*
2397 * We have allocated the "original" page frame and we can
2398 * use it directly to store the loaded page.
2399 */
2400 last_highmem_page = page;
2401 return buffer;
2402 }
2403 /*
2404 * The "original" page frame has not been allocated and we have to
2405 * use a "safe" page frame to store the loaded page.
2406 */
2407 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2408 if (!pbe) {
2409 swsusp_free();
2410 return ERR_PTR(-ENOMEM);
2411 }
2412 pbe->orig_page = page;
2413 if (safe_highmem_pages > 0) {
2414 struct page *tmp;
2415
2416 /* Copy of the page will be stored in high memory */
2417 kaddr = buffer;
2418 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2419 safe_highmem_pages--;
2420 last_highmem_page = tmp;
2421 pbe->copy_page = tmp;
2422 } else {
2423 /* Copy of the page will be stored in normal memory */
2424 kaddr = safe_pages_list;
2425 safe_pages_list = safe_pages_list->next;
2426 pbe->copy_page = virt_to_page(kaddr);
2427 }
2428 pbe->next = highmem_pblist;
2429 highmem_pblist = pbe;
2430 return kaddr;
2431}
2432
2433/**
2434 * copy_last_highmem_page - Copy most the most recent highmem image page.
2435 *
2436 * Copy the contents of a highmem image from @buffer, where the caller of
2437 * snapshot_write_next() has stored them, to the right location represented by
2438 * @last_highmem_page .
2439 */
2440static void copy_last_highmem_page(void)
2441{
2442 if (last_highmem_page) {
2443 void *dst;
2444
2445 dst = kmap_atomic(last_highmem_page);
2446 copy_page(dst, buffer);
2447 kunmap_atomic(dst);
2448 last_highmem_page = NULL;
2449 }
2450}
2451
2452static inline int last_highmem_page_copied(void)
2453{
2454 return !last_highmem_page;
2455}
2456
2457static inline void free_highmem_data(void)
2458{
2459 if (safe_highmem_bm)
2460 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2461
2462 if (buffer)
2463 free_image_page(buffer, PG_UNSAFE_CLEAR);
2464}
2465#else
2466static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2467
2468static inline int prepare_highmem_image(struct memory_bitmap *bm,
2469 unsigned int *nr_highmem_p) { return 0; }
2470
2471static inline void *get_highmem_page_buffer(struct page *page,
2472 struct chain_allocator *ca)
2473{
2474 return ERR_PTR(-EINVAL);
2475}
2476
2477static inline void copy_last_highmem_page(void) {}
2478static inline int last_highmem_page_copied(void) { return 1; }
2479static inline void free_highmem_data(void) {}
2480#endif /* CONFIG_HIGHMEM */
2481
2482#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2483
2484/**
2485 * prepare_image - Make room for loading hibernation image.
2486 * @new_bm: Uninitialized memory bitmap structure.
2487 * @bm: Memory bitmap with unsafe pages marked.
2488 *
2489 * Use @bm to mark the pages that will be overwritten in the process of
2490 * restoring the system memory state from the suspend image ("unsafe" pages)
2491 * and allocate memory for the image.
2492 *
2493 * The idea is to allocate a new memory bitmap first and then allocate
2494 * as many pages as needed for image data, but without specifying what those
2495 * pages will be used for just yet. Instead, we mark them all as allocated and
2496 * create a lists of "safe" pages to be used later. On systems with high
2497 * memory a list of "safe" highmem pages is created too.
2498 */
2499static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2500{
2501 unsigned int nr_pages, nr_highmem;
2502 struct linked_page *lp;
2503 int error;
2504
2505 /* If there is no highmem, the buffer will not be necessary */
2506 free_image_page(buffer, PG_UNSAFE_CLEAR);
2507 buffer = NULL;
2508
2509 nr_highmem = count_highmem_image_pages(bm);
2510 mark_unsafe_pages(bm);
2511
2512 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2513 if (error)
2514 goto Free;
2515
2516 duplicate_memory_bitmap(new_bm, bm);
2517 memory_bm_free(bm, PG_UNSAFE_KEEP);
2518 if (nr_highmem > 0) {
2519 error = prepare_highmem_image(bm, &nr_highmem);
2520 if (error)
2521 goto Free;
2522 }
2523 /*
2524 * Reserve some safe pages for potential later use.
2525 *
2526 * NOTE: This way we make sure there will be enough safe pages for the
2527 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2528 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2529 *
2530 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2531 */
2532 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2533 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2534 while (nr_pages > 0) {
2535 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2536 if (!lp) {
2537 error = -ENOMEM;
2538 goto Free;
2539 }
2540 lp->next = safe_pages_list;
2541 safe_pages_list = lp;
2542 nr_pages--;
2543 }
2544 /* Preallocate memory for the image */
2545 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2546 while (nr_pages > 0) {
2547 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2548 if (!lp) {
2549 error = -ENOMEM;
2550 goto Free;
2551 }
2552 if (!swsusp_page_is_free(virt_to_page(lp))) {
2553 /* The page is "safe", add it to the list */
2554 lp->next = safe_pages_list;
2555 safe_pages_list = lp;
2556 }
2557 /* Mark the page as allocated */
2558 swsusp_set_page_forbidden(virt_to_page(lp));
2559 swsusp_set_page_free(virt_to_page(lp));
2560 nr_pages--;
2561 }
2562 return 0;
2563
2564 Free:
2565 swsusp_free();
2566 return error;
2567}
2568
2569/**
2570 * get_buffer - Get the address to store the next image data page.
2571 *
2572 * Get the address that snapshot_write_next() should return to its caller to
2573 * write to.
2574 */
2575static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2576{
2577 struct pbe *pbe;
2578 struct page *page;
2579 unsigned long pfn = memory_bm_next_pfn(bm);
2580
2581 if (pfn == BM_END_OF_MAP)
2582 return ERR_PTR(-EFAULT);
2583
2584 page = pfn_to_page(pfn);
2585 if (PageHighMem(page))
2586 return get_highmem_page_buffer(page, ca);
2587
2588 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2589 /*
2590 * We have allocated the "original" page frame and we can
2591 * use it directly to store the loaded page.
2592 */
2593 return page_address(page);
2594
2595 /*
2596 * The "original" page frame has not been allocated and we have to
2597 * use a "safe" page frame to store the loaded page.
2598 */
2599 pbe = chain_alloc(ca, sizeof(struct pbe));
2600 if (!pbe) {
2601 swsusp_free();
2602 return ERR_PTR(-ENOMEM);
2603 }
2604 pbe->orig_address = page_address(page);
2605 pbe->address = safe_pages_list;
2606 safe_pages_list = safe_pages_list->next;
2607 pbe->next = restore_pblist;
2608 restore_pblist = pbe;
2609 return pbe->address;
2610}
2611
2612/**
2613 * snapshot_write_next - Get the address to store the next image page.
2614 * @handle: Snapshot handle structure to guide the writing.
2615 *
2616 * On the first call, @handle should point to a zeroed snapshot_handle
2617 * structure. The structure gets populated then and a pointer to it should be
2618 * passed to this function every next time.
2619 *
2620 * On success, the function returns a positive number. Then, the caller
2621 * is allowed to write up to the returned number of bytes to the memory
2622 * location computed by the data_of() macro.
2623 *
2624 * The function returns 0 to indicate the "end of file" condition. Negative
2625 * numbers are returned on errors, in which cases the structure pointed to by
2626 * @handle is not updated and should not be used any more.
2627 */
2628int snapshot_write_next(struct snapshot_handle *handle)
2629{
2630 static struct chain_allocator ca;
2631 int error = 0;
2632
2633 /* Check if we have already loaded the entire image */
2634 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2635 return 0;
2636
2637 handle->sync_read = 1;
2638
2639 if (!handle->cur) {
2640 if (!buffer)
2641 /* This makes the buffer be freed by swsusp_free() */
2642 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2643
2644 if (!buffer)
2645 return -ENOMEM;
2646
2647 handle->buffer = buffer;
2648 } else if (handle->cur == 1) {
2649 error = load_header(buffer);
2650 if (error)
2651 return error;
2652
2653 safe_pages_list = NULL;
2654
2655 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2656 if (error)
2657 return error;
2658
2659 hibernate_restore_protection_begin();
2660 } else if (handle->cur <= nr_meta_pages + 1) {
2661 error = unpack_orig_pfns(buffer, ©_bm);
2662 if (error)
2663 return error;
2664
2665 if (handle->cur == nr_meta_pages + 1) {
2666 error = prepare_image(&orig_bm, ©_bm);
2667 if (error)
2668 return error;
2669
2670 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2671 memory_bm_position_reset(&orig_bm);
2672 restore_pblist = NULL;
2673 handle->buffer = get_buffer(&orig_bm, &ca);
2674 handle->sync_read = 0;
2675 if (IS_ERR(handle->buffer))
2676 return PTR_ERR(handle->buffer);
2677 }
2678 } else {
2679 copy_last_highmem_page();
2680 hibernate_restore_protect_page(handle->buffer);
2681 handle->buffer = get_buffer(&orig_bm, &ca);
2682 if (IS_ERR(handle->buffer))
2683 return PTR_ERR(handle->buffer);
2684 if (handle->buffer != buffer)
2685 handle->sync_read = 0;
2686 }
2687 handle->cur++;
2688 return PAGE_SIZE;
2689}
2690
2691/**
2692 * snapshot_write_finalize - Complete the loading of a hibernation image.
2693 *
2694 * Must be called after the last call to snapshot_write_next() in case the last
2695 * page in the image happens to be a highmem page and its contents should be
2696 * stored in highmem. Additionally, it recycles bitmap memory that's not
2697 * necessary any more.
2698 */
2699void snapshot_write_finalize(struct snapshot_handle *handle)
2700{
2701 copy_last_highmem_page();
2702 hibernate_restore_protect_page(handle->buffer);
2703 /* Do that only if we have loaded the image entirely */
2704 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2705 memory_bm_recycle(&orig_bm);
2706 free_highmem_data();
2707 }
2708}
2709
2710int snapshot_image_loaded(struct snapshot_handle *handle)
2711{
2712 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2713 handle->cur <= nr_meta_pages + nr_copy_pages);
2714}
2715
2716#ifdef CONFIG_HIGHMEM
2717/* Assumes that @buf is ready and points to a "safe" page */
2718static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2719 void *buf)
2720{
2721 void *kaddr1, *kaddr2;
2722
2723 kaddr1 = kmap_atomic(p1);
2724 kaddr2 = kmap_atomic(p2);
2725 copy_page(buf, kaddr1);
2726 copy_page(kaddr1, kaddr2);
2727 copy_page(kaddr2, buf);
2728 kunmap_atomic(kaddr2);
2729 kunmap_atomic(kaddr1);
2730}
2731
2732/**
2733 * restore_highmem - Put highmem image pages into their original locations.
2734 *
2735 * For each highmem page that was in use before hibernation and is included in
2736 * the image, and also has been allocated by the "restore" kernel, swap its
2737 * current contents with the previous (ie. "before hibernation") ones.
2738 *
2739 * If the restore eventually fails, we can call this function once again and
2740 * restore the highmem state as seen by the restore kernel.
2741 */
2742int restore_highmem(void)
2743{
2744 struct highmem_pbe *pbe = highmem_pblist;
2745 void *buf;
2746
2747 if (!pbe)
2748 return 0;
2749
2750 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2751 if (!buf)
2752 return -ENOMEM;
2753
2754 while (pbe) {
2755 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2756 pbe = pbe->next;
2757 }
2758 free_image_page(buf, PG_UNSAFE_CLEAR);
2759 return 0;
2760}
2761#endif /* CONFIG_HIGHMEM */