2 * linux/kernel/power/snapshot.c
4 * This file provides system snapshot/restore functionality for swsusp.
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * This file is released under the GPLv2.
13 #include <linux/version.h>
14 #include <linux/module.h>
16 #include <linux/suspend.h>
17 #include <linux/smp_lock.h>
18 #include <linux/delay.h>
19 #include <linux/bitops.h>
20 #include <linux/spinlock.h>
21 #include <linux/kernel.h>
23 #include <linux/device.h>
24 #include <linux/init.h>
25 #include <linux/bootmem.h>
26 #include <linux/syscalls.h>
27 #include <linux/console.h>
28 #include <linux/highmem.h>
30 #include <asm/uaccess.h>
31 #include <asm/mmu_context.h>
32 #include <asm/pgtable.h>
33 #include <asm/tlbflush.h>
38 static int swsusp_page_is_free(struct page *);
39 static void swsusp_set_page_forbidden(struct page *);
40 static void swsusp_unset_page_forbidden(struct page *);
42 /* List of PBEs needed for restoring the pages that were allocated before
43 * the suspend and included in the suspend image, but have also been
44 * allocated by the "resume" kernel, so their contents cannot be written
45 * directly to their "original" page frames.
47 struct pbe *restore_pblist;
49 /* Pointer to an auxiliary buffer (1 page) */
53 * @safe_needed - on resume, for storing the PBE list and the image,
54 * we can only use memory pages that do not conflict with the pages
55 * used before suspend. The unsafe pages have PageNosaveFree set
56 * and we count them using unsafe_pages.
58 * Each allocated image page is marked as PageNosave and PageNosaveFree
59 * so that swsusp_free() can release it.
64 #define PG_UNSAFE_CLEAR 1
65 #define PG_UNSAFE_KEEP 0
67 static unsigned int allocated_unsafe_pages;
69 static void *get_image_page(gfp_t gfp_mask, int safe_needed)
73 res = (void *)get_zeroed_page(gfp_mask);
75 while (res && swsusp_page_is_free(virt_to_page(res))) {
76 /* The page is unsafe, mark it for swsusp_free() */
77 swsusp_set_page_forbidden(virt_to_page(res));
78 allocated_unsafe_pages++;
79 res = (void *)get_zeroed_page(gfp_mask);
82 swsusp_set_page_forbidden(virt_to_page(res));
83 swsusp_set_page_free(virt_to_page(res));
88 unsigned long get_safe_page(gfp_t gfp_mask)
90 return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
93 static struct page *alloc_image_page(gfp_t gfp_mask)
97 page = alloc_page(gfp_mask);
99 swsusp_set_page_forbidden(page);
100 swsusp_set_page_free(page);
106 * free_image_page - free page represented by @addr, allocated with
107 * get_image_page (page flags set by it must be cleared)
110 static inline void free_image_page(void *addr, int clear_nosave_free)
114 BUG_ON(!virt_addr_valid(addr));
116 page = virt_to_page(addr);
118 swsusp_unset_page_forbidden(page);
119 if (clear_nosave_free)
120 swsusp_unset_page_free(page);
125 /* struct linked_page is used to build chains of pages */
127 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
130 struct linked_page *next;
131 char data[LINKED_PAGE_DATA_SIZE];
132 } __attribute__((packed));
135 free_list_of_pages(struct linked_page *list, int clear_page_nosave)
138 struct linked_page *lp = list->next;
140 free_image_page(list, clear_page_nosave);
146 * struct chain_allocator is used for allocating small objects out of
147 * a linked list of pages called 'the chain'.
149 * The chain grows each time when there is no room for a new object in
150 * the current page. The allocated objects cannot be freed individually.
151 * It is only possible to free them all at once, by freeing the entire
154 * NOTE: The chain allocator may be inefficient if the allocated objects
155 * are not much smaller than PAGE_SIZE.
158 struct chain_allocator {
159 struct linked_page *chain; /* the chain */
160 unsigned int used_space; /* total size of objects allocated out
161 * of the current page
163 gfp_t gfp_mask; /* mask for allocating pages */
164 int safe_needed; /* if set, only "safe" pages are allocated */
168 chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
171 ca->used_space = LINKED_PAGE_DATA_SIZE;
172 ca->gfp_mask = gfp_mask;
173 ca->safe_needed = safe_needed;
176 static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
180 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
181 struct linked_page *lp;
183 lp = get_image_page(ca->gfp_mask, ca->safe_needed);
187 lp->next = ca->chain;
191 ret = ca->chain->data + ca->used_space;
192 ca->used_space += size;
196 static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
198 free_list_of_pages(ca->chain, clear_page_nosave);
199 memset(ca, 0, sizeof(struct chain_allocator));
203 * Data types related to memory bitmaps.
205 * Memory bitmap is a structure consiting of many linked lists of
206 * objects. The main list's elements are of type struct zone_bitmap
207 * and each of them corresonds to one zone. For each zone bitmap
208 * object there is a list of objects of type struct bm_block that
209 * represent each blocks of bit chunks in which information is
212 * struct memory_bitmap contains a pointer to the main list of zone
213 * bitmap objects, a struct bm_position used for browsing the bitmap,
214 * and a pointer to the list of pages used for allocating all of the
215 * zone bitmap objects and bitmap block objects.
217 * NOTE: It has to be possible to lay out the bitmap in memory
218 * using only allocations of order 0. Additionally, the bitmap is
219 * designed to work with arbitrary number of zones (this is over the
220 * top for now, but let's avoid making unnecessary assumptions ;-).
222 * struct zone_bitmap contains a pointer to a list of bitmap block
223 * objects and a pointer to the bitmap block object that has been
224 * most recently used for setting bits. Additionally, it contains the
225 * pfns that correspond to the start and end of the represented zone.
227 * struct bm_block contains a pointer to the memory page in which
228 * information is stored (in the form of a block of bit chunks
229 * of type unsigned long each). It also contains the pfns that
230 * correspond to the start and end of the represented memory area and
231 * the number of bit chunks in the block.
234 #define BM_END_OF_MAP (~0UL)
236 #define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long))
237 #define BM_BITS_PER_CHUNK (sizeof(long) << 3)
238 #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3)
241 struct bm_block *next; /* next element of the list */
242 unsigned long start_pfn; /* pfn represented by the first bit */
243 unsigned long end_pfn; /* pfn represented by the last bit plus 1 */
244 unsigned int size; /* number of bit chunks */
245 unsigned long *data; /* chunks of bits representing pages */
249 struct zone_bitmap *next; /* next element of the list */
250 unsigned long start_pfn; /* minimal pfn in this zone */
251 unsigned long end_pfn; /* maximal pfn in this zone plus 1 */
252 struct bm_block *bm_blocks; /* list of bitmap blocks */
253 struct bm_block *cur_block; /* recently used bitmap block */
256 /* strcut bm_position is used for browsing memory bitmaps */
259 struct zone_bitmap *zone_bm;
260 struct bm_block *block;
265 struct memory_bitmap {
266 struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */
267 struct linked_page *p_list; /* list of pages used to store zone
268 * bitmap objects and bitmap block
271 struct bm_position cur; /* most recently used bit position */
274 /* Functions that operate on memory bitmaps */
276 static inline void memory_bm_reset_chunk(struct memory_bitmap *bm)
282 static void memory_bm_position_reset(struct memory_bitmap *bm)
284 struct zone_bitmap *zone_bm;
286 zone_bm = bm->zone_bm_list;
287 bm->cur.zone_bm = zone_bm;
288 bm->cur.block = zone_bm->bm_blocks;
289 memory_bm_reset_chunk(bm);
292 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
295 * create_bm_block_list - create a list of block bitmap objects
298 static inline struct bm_block *
299 create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
301 struct bm_block *bblist = NULL;
303 while (nr_blocks-- > 0) {
306 bb = chain_alloc(ca, sizeof(struct bm_block));
317 * create_zone_bm_list - create a list of zone bitmap objects
320 static inline struct zone_bitmap *
321 create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
323 struct zone_bitmap *zbmlist = NULL;
325 while (nr_zones-- > 0) {
326 struct zone_bitmap *zbm;
328 zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
339 * memory_bm_create - allocate memory for a memory bitmap
343 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
345 struct chain_allocator ca;
347 struct zone_bitmap *zone_bm;
351 chain_init(&ca, gfp_mask, safe_needed);
353 /* Compute the number of zones */
356 if (populated_zone(zone))
359 /* Allocate the list of zones bitmap objects */
360 zone_bm = create_zone_bm_list(nr, &ca);
361 bm->zone_bm_list = zone_bm;
363 chain_free(&ca, PG_UNSAFE_CLEAR);
367 /* Initialize the zone bitmap objects */
368 for_each_zone(zone) {
371 if (!populated_zone(zone))
374 zone_bm->start_pfn = zone->zone_start_pfn;
375 zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages;
376 /* Allocate the list of bitmap block objects */
377 nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
378 bb = create_bm_block_list(nr, &ca);
379 zone_bm->bm_blocks = bb;
380 zone_bm->cur_block = bb;
384 nr = zone->spanned_pages;
385 pfn = zone->zone_start_pfn;
386 /* Initialize the bitmap block objects */
390 ptr = get_image_page(gfp_mask, safe_needed);
396 if (nr >= BM_BITS_PER_BLOCK) {
397 pfn += BM_BITS_PER_BLOCK;
398 bb->size = BM_CHUNKS_PER_BLOCK;
399 nr -= BM_BITS_PER_BLOCK;
401 /* This is executed only once in the loop */
403 bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK);
408 zone_bm = zone_bm->next;
410 bm->p_list = ca.chain;
411 memory_bm_position_reset(bm);
415 bm->p_list = ca.chain;
416 memory_bm_free(bm, PG_UNSAFE_CLEAR);
421 * memory_bm_free - free memory occupied by the memory bitmap @bm
424 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
426 struct zone_bitmap *zone_bm;
428 /* Free the list of bit blocks for each zone_bitmap object */
429 zone_bm = bm->zone_bm_list;
433 bb = zone_bm->bm_blocks;
436 free_image_page(bb->data, clear_nosave_free);
439 zone_bm = zone_bm->next;
441 free_list_of_pages(bm->p_list, clear_nosave_free);
442 bm->zone_bm_list = NULL;
446 * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
447 * to given pfn. The cur_zone_bm member of @bm and the cur_block member
448 * of @bm->cur_zone_bm are updated.
451 static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
452 void **addr, unsigned int *bit_nr)
454 struct zone_bitmap *zone_bm;
457 /* Check if the pfn is from the current zone */
458 zone_bm = bm->cur.zone_bm;
459 if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
460 zone_bm = bm->zone_bm_list;
461 /* We don't assume that the zones are sorted by pfns */
462 while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
463 zone_bm = zone_bm->next;
467 bm->cur.zone_bm = zone_bm;
469 /* Check if the pfn corresponds to the current bitmap block */
470 bb = zone_bm->cur_block;
471 if (pfn < bb->start_pfn)
472 bb = zone_bm->bm_blocks;
474 while (pfn >= bb->end_pfn) {
479 zone_bm->cur_block = bb;
480 pfn -= bb->start_pfn;
481 *bit_nr = pfn % BM_BITS_PER_CHUNK;
482 *addr = bb->data + pfn / BM_BITS_PER_CHUNK;
485 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
490 memory_bm_find_bit(bm, pfn, &addr, &bit);
494 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
499 memory_bm_find_bit(bm, pfn, &addr, &bit);
500 clear_bit(bit, addr);
503 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
508 memory_bm_find_bit(bm, pfn, &addr, &bit);
509 return test_bit(bit, addr);
512 /* Two auxiliary functions for memory_bm_next_pfn */
514 /* Find the first set bit in the given chunk, if there is one */
516 static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
519 while (bit < BM_BITS_PER_CHUNK) {
520 if (test_bit(bit, chunk_p))
528 /* Find a chunk containing some bits set in given block of bits */
530 static inline int next_chunk_in_block(int n, struct bm_block *bb)
533 while (n < bb->size) {
543 * memory_bm_next_pfn - find the pfn that corresponds to the next set bit
544 * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
547 * It is required to run memory_bm_position_reset() before the first call to
551 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
553 struct zone_bitmap *zone_bm;
561 chunk = bm->cur.chunk;
564 bit = next_bit_in_chunk(bit, bb->data + chunk);
568 chunk = next_chunk_in_block(chunk, bb);
570 } while (chunk >= 0);
573 memory_bm_reset_chunk(bm);
575 zone_bm = bm->cur.zone_bm->next;
577 bm->cur.zone_bm = zone_bm;
578 bm->cur.block = zone_bm->bm_blocks;
579 memory_bm_reset_chunk(bm);
582 memory_bm_position_reset(bm);
583 return BM_END_OF_MAP;
586 bm->cur.chunk = chunk;
588 return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit;
592 * This structure represents a range of page frames the contents of which
593 * should not be saved during the suspend.
596 struct nosave_region {
597 struct list_head list;
598 unsigned long start_pfn;
599 unsigned long end_pfn;
602 static LIST_HEAD(nosave_regions);
605 * register_nosave_region - register a range of page frames the contents
606 * of which should not be saved during the suspend (to be used in the early
607 * initialization code)
611 register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
613 struct nosave_region *region;
615 if (start_pfn >= end_pfn)
618 if (!list_empty(&nosave_regions)) {
619 /* Try to extend the previous region (they should be sorted) */
620 region = list_entry(nosave_regions.prev,
621 struct nosave_region, list);
622 if (region->end_pfn == start_pfn) {
623 region->end_pfn = end_pfn;
627 /* This allocation cannot fail */
628 region = alloc_bootmem_low(sizeof(struct nosave_region));
629 region->start_pfn = start_pfn;
630 region->end_pfn = end_pfn;
631 list_add_tail(®ion->list, &nosave_regions);
633 printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
634 start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
638 * Set bits in this map correspond to the page frames the contents of which
639 * should not be saved during the suspend.
641 static struct memory_bitmap *forbidden_pages_map;
643 /* Set bits in this map correspond to free page frames. */
644 static struct memory_bitmap *free_pages_map;
647 * Each page frame allocated for creating the image is marked by setting the
648 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
651 void swsusp_set_page_free(struct page *page)
654 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
657 static int swsusp_page_is_free(struct page *page)
659 return free_pages_map ?
660 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
663 void swsusp_unset_page_free(struct page *page)
666 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
669 static void swsusp_set_page_forbidden(struct page *page)
671 if (forbidden_pages_map)
672 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
675 int swsusp_page_is_forbidden(struct page *page)
677 return forbidden_pages_map ?
678 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
681 static void swsusp_unset_page_forbidden(struct page *page)
683 if (forbidden_pages_map)
684 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
688 * mark_nosave_pages - set bits corresponding to the page frames the
689 * contents of which should not be saved in a given bitmap.
692 static void mark_nosave_pages(struct memory_bitmap *bm)
694 struct nosave_region *region;
696 if (list_empty(&nosave_regions))
699 list_for_each_entry(region, &nosave_regions, list) {
702 printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
703 region->start_pfn << PAGE_SHIFT,
704 region->end_pfn << PAGE_SHIFT);
706 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
707 memory_bm_set_bit(bm, pfn);
712 * create_basic_memory_bitmaps - create bitmaps needed for marking page
713 * frames that should not be saved and free page frames. The pointers
714 * forbidden_pages_map and free_pages_map are only modified if everything
715 * goes well, because we don't want the bits to be used before both bitmaps
719 int create_basic_memory_bitmaps(void)
721 struct memory_bitmap *bm1, *bm2;
724 BUG_ON(forbidden_pages_map || free_pages_map);
726 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
730 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
732 goto Free_first_object;
734 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
736 goto Free_first_bitmap;
738 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
740 goto Free_second_object;
742 forbidden_pages_map = bm1;
743 free_pages_map = bm2;
744 mark_nosave_pages(forbidden_pages_map);
746 printk("swsusp: Basic memory bitmaps created\n");
753 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
760 * free_basic_memory_bitmaps - free memory bitmaps allocated by
761 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
762 * so that the bitmaps themselves are not referred to while they are being
766 void free_basic_memory_bitmaps(void)
768 struct memory_bitmap *bm1, *bm2;
770 BUG_ON(!(forbidden_pages_map && free_pages_map));
772 bm1 = forbidden_pages_map;
773 bm2 = free_pages_map;
774 forbidden_pages_map = NULL;
775 free_pages_map = NULL;
776 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
778 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
781 printk("swsusp: Basic memory bitmaps freed\n");
785 * snapshot_additional_pages - estimate the number of additional pages
786 * be needed for setting up the suspend image data structures for given
787 * zone (usually the returned value is greater than the exact number)
790 unsigned int snapshot_additional_pages(struct zone *zone)
794 res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
795 res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
799 #ifdef CONFIG_HIGHMEM
801 * count_free_highmem_pages - compute the total number of free highmem
802 * pages, system-wide.
805 static unsigned int count_free_highmem_pages(void)
808 unsigned int cnt = 0;
811 if (populated_zone(zone) && is_highmem(zone))
812 cnt += zone_page_state(zone, NR_FREE_PAGES);
818 * saveable_highmem_page - Determine whether a highmem page should be
819 * included in the suspend image.
821 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
822 * and it isn't a part of a free chunk of pages.
825 static struct page *saveable_highmem_page(unsigned long pfn)
832 page = pfn_to_page(pfn);
834 BUG_ON(!PageHighMem(page));
836 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
844 * count_highmem_pages - compute the total number of saveable highmem
848 unsigned int count_highmem_pages(void)
853 for_each_zone(zone) {
854 unsigned long pfn, max_zone_pfn;
856 if (!is_highmem(zone))
859 mark_free_pages(zone);
860 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
861 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
862 if (saveable_highmem_page(pfn))
868 static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
869 static inline unsigned int count_highmem_pages(void) { return 0; }
870 #endif /* CONFIG_HIGHMEM */
873 * saveable - Determine whether a non-highmem page should be included in
876 * We should save the page if it isn't Nosave, and is not in the range
877 * of pages statically defined as 'unsaveable', and it isn't a part of
878 * a free chunk of pages.
881 static struct page *saveable_page(unsigned long pfn)
888 page = pfn_to_page(pfn);
890 BUG_ON(PageHighMem(page));
892 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
895 if (PageReserved(page) && pfn_is_nosave(pfn))
902 * count_data_pages - compute the total number of saveable non-highmem
906 unsigned int count_data_pages(void)
909 unsigned long pfn, max_zone_pfn;
912 for_each_zone(zone) {
913 if (is_highmem(zone))
916 mark_free_pages(zone);
917 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
918 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
919 if(saveable_page(pfn))
925 /* This is needed, because copy_page and memcpy are not usable for copying
928 static inline void do_copy_page(long *dst, long *src)
932 for (n = PAGE_SIZE / sizeof(long); n; n--)
936 #ifdef CONFIG_HIGHMEM
937 static inline struct page *
938 page_is_saveable(struct zone *zone, unsigned long pfn)
940 return is_highmem(zone) ?
941 saveable_highmem_page(pfn) : saveable_page(pfn);
945 copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
947 struct page *s_page, *d_page;
950 s_page = pfn_to_page(src_pfn);
951 d_page = pfn_to_page(dst_pfn);
952 if (PageHighMem(s_page)) {
953 src = kmap_atomic(s_page, KM_USER0);
954 dst = kmap_atomic(d_page, KM_USER1);
955 do_copy_page(dst, src);
956 kunmap_atomic(src, KM_USER0);
957 kunmap_atomic(dst, KM_USER1);
959 src = page_address(s_page);
960 if (PageHighMem(d_page)) {
961 /* Page pointed to by src may contain some kernel
962 * data modified by kmap_atomic()
964 do_copy_page(buffer, src);
965 dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
966 memcpy(dst, buffer, PAGE_SIZE);
967 kunmap_atomic(dst, KM_USER0);
969 dst = page_address(d_page);
970 do_copy_page(dst, src);
975 #define page_is_saveable(zone, pfn) saveable_page(pfn)
978 copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
980 do_copy_page(page_address(pfn_to_page(dst_pfn)),
981 page_address(pfn_to_page(src_pfn)));
983 #endif /* CONFIG_HIGHMEM */
986 copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
991 for_each_zone(zone) {
992 unsigned long max_zone_pfn;
994 mark_free_pages(zone);
995 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
996 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
997 if (page_is_saveable(zone, pfn))
998 memory_bm_set_bit(orig_bm, pfn);
1000 memory_bm_position_reset(orig_bm);
1001 memory_bm_position_reset(copy_bm);
1003 pfn = memory_bm_next_pfn(orig_bm);
1004 if (likely(pfn != BM_END_OF_MAP))
1005 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1006 } while (pfn != BM_END_OF_MAP);
1009 /* Total number of image pages */
1010 static unsigned int nr_copy_pages;
1011 /* Number of pages needed for saving the original pfns of the image pages */
1012 static unsigned int nr_meta_pages;
1015 * swsusp_free - free pages allocated for the suspend.
1017 * Suspend pages are alocated before the atomic copy is made, so we
1018 * need to release them after the resume.
1021 void swsusp_free(void)
1024 unsigned long pfn, max_zone_pfn;
1026 for_each_zone(zone) {
1027 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1028 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1029 if (pfn_valid(pfn)) {
1030 struct page *page = pfn_to_page(pfn);
1032 if (swsusp_page_is_forbidden(page) &&
1033 swsusp_page_is_free(page)) {
1034 swsusp_unset_page_forbidden(page);
1035 swsusp_unset_page_free(page);
1042 restore_pblist = NULL;
1046 #ifdef CONFIG_HIGHMEM
1048 * count_pages_for_highmem - compute the number of non-highmem pages
1049 * that will be necessary for creating copies of highmem pages.
1052 static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1054 unsigned int free_highmem = count_free_highmem_pages();
1056 if (free_highmem >= nr_highmem)
1059 nr_highmem -= free_highmem;
1065 count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1066 #endif /* CONFIG_HIGHMEM */
1069 * enough_free_mem - Make sure we have enough free memory for the
1073 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1076 unsigned int free = 0, meta = 0;
1078 for_each_zone(zone) {
1079 meta += snapshot_additional_pages(zone);
1080 if (!is_highmem(zone))
1081 free += zone_page_state(zone, NR_FREE_PAGES);
1084 nr_pages += count_pages_for_highmem(nr_highmem);
1085 pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
1086 nr_pages, PAGES_FOR_IO, meta, free);
1088 return free > nr_pages + PAGES_FOR_IO + meta;
1091 #ifdef CONFIG_HIGHMEM
1093 * get_highmem_buffer - if there are some highmem pages in the suspend
1094 * image, we may need the buffer to copy them and/or load their data.
1097 static inline int get_highmem_buffer(int safe_needed)
1099 buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
1100 return buffer ? 0 : -ENOMEM;
1104 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1105 * Try to allocate as many pages as needed, but if the number of free
1106 * highmem pages is lesser than that, allocate them all.
1109 static inline unsigned int
1110 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
1112 unsigned int to_alloc = count_free_highmem_pages();
1114 if (to_alloc > nr_highmem)
1115 to_alloc = nr_highmem;
1117 nr_highmem -= to_alloc;
1118 while (to_alloc-- > 0) {
1121 page = alloc_image_page(__GFP_HIGHMEM);
1122 memory_bm_set_bit(bm, page_to_pfn(page));
1127 static inline int get_highmem_buffer(int safe_needed) { return 0; }
1129 static inline unsigned int
1130 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
1131 #endif /* CONFIG_HIGHMEM */
1134 * swsusp_alloc - allocate memory for the suspend image
1136 * We first try to allocate as many highmem pages as there are
1137 * saveable highmem pages in the system. If that fails, we allocate
1138 * non-highmem pages for the copies of the remaining highmem ones.
1140 * In this approach it is likely that the copies of highmem pages will
1141 * also be located in the high memory, because of the way in which
1142 * copy_data_pages() works.
1146 swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
1147 unsigned int nr_pages, unsigned int nr_highmem)
1151 error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1155 error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1159 if (nr_highmem > 0) {
1160 error = get_highmem_buffer(PG_ANY);
1164 nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem);
1166 while (nr_pages-- > 0) {
1167 struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
1172 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1181 /* Memory bitmap used for marking saveable pages (during suspend) or the
1182 * suspend image pages (during resume)
1184 static struct memory_bitmap orig_bm;
1185 /* Memory bitmap used on suspend for marking allocated pages that will contain
1186 * the copies of saveable pages. During resume it is initially used for
1187 * marking the suspend image pages, but then its set bits are duplicated in
1188 * @orig_bm and it is released. Next, on systems with high memory, it may be
1189 * used for marking "safe" highmem pages, but it has to be reinitialized for
1192 static struct memory_bitmap copy_bm;
1194 asmlinkage int swsusp_save(void)
1196 unsigned int nr_pages, nr_highmem;
1198 printk("swsusp: critical section: \n");
1200 drain_local_pages();
1201 nr_pages = count_data_pages();
1202 nr_highmem = count_highmem_pages();
1203 printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem);
1205 if (!enough_free_mem(nr_pages, nr_highmem)) {
1206 printk(KERN_ERR "swsusp: Not enough free memory\n");
1210 if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) {
1211 printk(KERN_ERR "swsusp: Memory allocation failed\n");
1215 /* During allocating of suspend pagedir, new cold pages may appear.
1218 drain_local_pages();
1219 copy_data_pages(©_bm, &orig_bm);
1222 * End of critical section. From now on, we can write to memory,
1223 * but we should not touch disk. This specially means we must _not_
1224 * touch swap space! Except we must write out our image of course.
1227 nr_pages += nr_highmem;
1228 nr_copy_pages = nr_pages;
1229 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
1231 printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
1236 static void init_header(struct swsusp_info *info)
1238 memset(info, 0, sizeof(struct swsusp_info));
1239 info->version_code = LINUX_VERSION_CODE;
1240 info->num_physpages = num_physpages;
1241 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
1242 info->cpus = num_online_cpus();
1243 info->image_pages = nr_copy_pages;
1244 info->pages = nr_copy_pages + nr_meta_pages + 1;
1245 info->size = info->pages;
1246 info->size <<= PAGE_SHIFT;
1250 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1251 * are stored in the array @buf[] (1 page at a time)
1255 pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
1259 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1260 buf[j] = memory_bm_next_pfn(bm);
1261 if (unlikely(buf[j] == BM_END_OF_MAP))
1267 * snapshot_read_next - used for reading the system memory snapshot.
1269 * On the first call to it @handle should point to a zeroed
1270 * snapshot_handle structure. The structure gets updated and a pointer
1271 * to it should be passed to this function every next time.
1273 * The @count parameter should contain the number of bytes the caller
1274 * wants to read from the snapshot. It must not be zero.
1276 * On success the function returns a positive number. Then, the caller
1277 * is allowed to read up to the returned number of bytes from the memory
1278 * location computed by the data_of() macro. The number returned
1279 * may be smaller than @count, but this only happens if the read would
1280 * cross a page boundary otherwise.
1282 * The function returns 0 to indicate the end of data stream condition,
1283 * and a negative number is returned on error. In such cases the
1284 * structure pointed to by @handle is not updated and should not be used
1288 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
1290 if (handle->cur > nr_meta_pages + nr_copy_pages)
1294 /* This makes the buffer be freed by swsusp_free() */
1295 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1299 if (!handle->offset) {
1300 init_header((struct swsusp_info *)buffer);
1301 handle->buffer = buffer;
1302 memory_bm_position_reset(&orig_bm);
1303 memory_bm_position_reset(©_bm);
1305 if (handle->prev < handle->cur) {
1306 if (handle->cur <= nr_meta_pages) {
1307 memset(buffer, 0, PAGE_SIZE);
1308 pack_pfns(buffer, &orig_bm);
1312 page = pfn_to_page(memory_bm_next_pfn(©_bm));
1313 if (PageHighMem(page)) {
1314 /* Highmem pages are copied to the buffer,
1315 * because we can't return with a kmapped
1316 * highmem page (we may not be called again).
1320 kaddr = kmap_atomic(page, KM_USER0);
1321 memcpy(buffer, kaddr, PAGE_SIZE);
1322 kunmap_atomic(kaddr, KM_USER0);
1323 handle->buffer = buffer;
1325 handle->buffer = page_address(page);
1328 handle->prev = handle->cur;
1330 handle->buf_offset = handle->cur_offset;
1331 if (handle->cur_offset + count >= PAGE_SIZE) {
1332 count = PAGE_SIZE - handle->cur_offset;
1333 handle->cur_offset = 0;
1336 handle->cur_offset += count;
1338 handle->offset += count;
1343 * mark_unsafe_pages - mark the pages that cannot be used for storing
1344 * the image during resume, because they conflict with the pages that
1345 * had been used before suspend
1348 static int mark_unsafe_pages(struct memory_bitmap *bm)
1351 unsigned long pfn, max_zone_pfn;
1353 /* Clear page flags */
1354 for_each_zone(zone) {
1355 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1356 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1358 swsusp_unset_page_free(pfn_to_page(pfn));
1361 /* Mark pages that correspond to the "original" pfns as "unsafe" */
1362 memory_bm_position_reset(bm);
1364 pfn = memory_bm_next_pfn(bm);
1365 if (likely(pfn != BM_END_OF_MAP)) {
1366 if (likely(pfn_valid(pfn)))
1367 swsusp_set_page_free(pfn_to_page(pfn));
1371 } while (pfn != BM_END_OF_MAP);
1373 allocated_unsafe_pages = 0;
1379 duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
1383 memory_bm_position_reset(src);
1384 pfn = memory_bm_next_pfn(src);
1385 while (pfn != BM_END_OF_MAP) {
1386 memory_bm_set_bit(dst, pfn);
1387 pfn = memory_bm_next_pfn(src);
1391 static inline int check_header(struct swsusp_info *info)
1393 char *reason = NULL;
1395 if (info->version_code != LINUX_VERSION_CODE)
1396 reason = "kernel version";
1397 if (info->num_physpages != num_physpages)
1398 reason = "memory size";
1399 if (strcmp(info->uts.sysname,init_utsname()->sysname))
1400 reason = "system type";
1401 if (strcmp(info->uts.release,init_utsname()->release))
1402 reason = "kernel release";
1403 if (strcmp(info->uts.version,init_utsname()->version))
1405 if (strcmp(info->uts.machine,init_utsname()->machine))
1408 printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
1415 * load header - check the image header and copy data from it
1419 load_header(struct swsusp_info *info)
1423 restore_pblist = NULL;
1424 error = check_header(info);
1426 nr_copy_pages = info->image_pages;
1427 nr_meta_pages = info->pages - info->image_pages - 1;
1433 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1434 * the corresponding bit in the memory bitmap @bm
1438 unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
1442 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1443 if (unlikely(buf[j] == BM_END_OF_MAP))
1446 memory_bm_set_bit(bm, buf[j]);
1450 /* List of "safe" pages that may be used to store data loaded from the suspend
1453 static struct linked_page *safe_pages_list;
1455 #ifdef CONFIG_HIGHMEM
1456 /* struct highmem_pbe is used for creating the list of highmem pages that
1457 * should be restored atomically during the resume from disk, because the page
1458 * frames they have occupied before the suspend are in use.
1460 struct highmem_pbe {
1461 struct page *copy_page; /* data is here now */
1462 struct page *orig_page; /* data was here before the suspend */
1463 struct highmem_pbe *next;
1466 /* List of highmem PBEs needed for restoring the highmem pages that were
1467 * allocated before the suspend and included in the suspend image, but have
1468 * also been allocated by the "resume" kernel, so their contents cannot be
1469 * written directly to their "original" page frames.
1471 static struct highmem_pbe *highmem_pblist;
1474 * count_highmem_image_pages - compute the number of highmem pages in the
1475 * suspend image. The bits in the memory bitmap @bm that correspond to the
1476 * image pages are assumed to be set.
1479 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
1482 unsigned int cnt = 0;
1484 memory_bm_position_reset(bm);
1485 pfn = memory_bm_next_pfn(bm);
1486 while (pfn != BM_END_OF_MAP) {
1487 if (PageHighMem(pfn_to_page(pfn)))
1490 pfn = memory_bm_next_pfn(bm);
1496 * prepare_highmem_image - try to allocate as many highmem pages as
1497 * there are highmem image pages (@nr_highmem_p points to the variable
1498 * containing the number of highmem image pages). The pages that are
1499 * "safe" (ie. will not be overwritten when the suspend image is
1500 * restored) have the corresponding bits set in @bm (it must be
1503 * NOTE: This function should not be called if there are no highmem
1507 static unsigned int safe_highmem_pages;
1509 static struct memory_bitmap *safe_highmem_bm;
1512 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1514 unsigned int to_alloc;
1516 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
1519 if (get_highmem_buffer(PG_SAFE))
1522 to_alloc = count_free_highmem_pages();
1523 if (to_alloc > *nr_highmem_p)
1524 to_alloc = *nr_highmem_p;
1526 *nr_highmem_p = to_alloc;
1528 safe_highmem_pages = 0;
1529 while (to_alloc-- > 0) {
1532 page = alloc_page(__GFP_HIGHMEM);
1533 if (!swsusp_page_is_free(page)) {
1534 /* The page is "safe", set its bit the bitmap */
1535 memory_bm_set_bit(bm, page_to_pfn(page));
1536 safe_highmem_pages++;
1538 /* Mark the page as allocated */
1539 swsusp_set_page_forbidden(page);
1540 swsusp_set_page_free(page);
1542 memory_bm_position_reset(bm);
1543 safe_highmem_bm = bm;
1548 * get_highmem_page_buffer - for given highmem image page find the buffer
1549 * that suspend_write_next() should set for its caller to write to.
1551 * If the page is to be saved to its "original" page frame or a copy of
1552 * the page is to be made in the highmem, @buffer is returned. Otherwise,
1553 * the copy of the page is to be made in normal memory, so the address of
1554 * the copy is returned.
1556 * If @buffer is returned, the caller of suspend_write_next() will write
1557 * the page's contents to @buffer, so they will have to be copied to the
1558 * right location on the next call to suspend_write_next() and it is done
1559 * with the help of copy_last_highmem_page(). For this purpose, if
1560 * @buffer is returned, @last_highmem page is set to the page to which
1561 * the data will have to be copied from @buffer.
1564 static struct page *last_highmem_page;
1567 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1569 struct highmem_pbe *pbe;
1572 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
1573 /* We have allocated the "original" page frame and we can
1574 * use it directly to store the loaded page.
1576 last_highmem_page = page;
1579 /* The "original" page frame has not been allocated and we have to
1580 * use a "safe" page frame to store the loaded page.
1582 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
1587 pbe->orig_page = page;
1588 if (safe_highmem_pages > 0) {
1591 /* Copy of the page will be stored in high memory */
1593 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
1594 safe_highmem_pages--;
1595 last_highmem_page = tmp;
1596 pbe->copy_page = tmp;
1598 /* Copy of the page will be stored in normal memory */
1599 kaddr = safe_pages_list;
1600 safe_pages_list = safe_pages_list->next;
1601 pbe->copy_page = virt_to_page(kaddr);
1603 pbe->next = highmem_pblist;
1604 highmem_pblist = pbe;
1609 * copy_last_highmem_page - copy the contents of a highmem image from
1610 * @buffer, where the caller of snapshot_write_next() has place them,
1611 * to the right location represented by @last_highmem_page .
1614 static void copy_last_highmem_page(void)
1616 if (last_highmem_page) {
1619 dst = kmap_atomic(last_highmem_page, KM_USER0);
1620 memcpy(dst, buffer, PAGE_SIZE);
1621 kunmap_atomic(dst, KM_USER0);
1622 last_highmem_page = NULL;
1626 static inline int last_highmem_page_copied(void)
1628 return !last_highmem_page;
1631 static inline void free_highmem_data(void)
1633 if (safe_highmem_bm)
1634 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
1637 free_image_page(buffer, PG_UNSAFE_CLEAR);
1640 static inline int get_safe_write_buffer(void) { return 0; }
1643 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
1646 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1651 static inline void *
1652 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1657 static inline void copy_last_highmem_page(void) {}
1658 static inline int last_highmem_page_copied(void) { return 1; }
1659 static inline void free_highmem_data(void) {}
1660 #endif /* CONFIG_HIGHMEM */
1663 * prepare_image - use the memory bitmap @bm to mark the pages that will
1664 * be overwritten in the process of restoring the system memory state
1665 * from the suspend image ("unsafe" pages) and allocate memory for the
1668 * The idea is to allocate a new memory bitmap first and then allocate
1669 * as many pages as needed for the image data, but not to assign these
1670 * pages to specific tasks initially. Instead, we just mark them as
1671 * allocated and create a lists of "safe" pages that will be used
1672 * later. On systems with high memory a list of "safe" highmem pages is
1676 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
1679 prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
1681 unsigned int nr_pages, nr_highmem;
1682 struct linked_page *sp_list, *lp;
1685 /* If there is no highmem, the buffer will not be necessary */
1686 free_image_page(buffer, PG_UNSAFE_CLEAR);
1689 nr_highmem = count_highmem_image_pages(bm);
1690 error = mark_unsafe_pages(bm);
1694 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
1698 duplicate_memory_bitmap(new_bm, bm);
1699 memory_bm_free(bm, PG_UNSAFE_KEEP);
1700 if (nr_highmem > 0) {
1701 error = prepare_highmem_image(bm, &nr_highmem);
1705 /* Reserve some safe pages for potential later use.
1707 * NOTE: This way we make sure there will be enough safe pages for the
1708 * chain_alloc() in get_buffer(). It is a bit wasteful, but
1709 * nr_copy_pages cannot be greater than 50% of the memory anyway.
1712 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
1713 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1714 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
1715 while (nr_pages > 0) {
1716 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
1725 /* Preallocate memory for the image */
1726 safe_pages_list = NULL;
1727 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1728 while (nr_pages > 0) {
1729 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
1734 if (!swsusp_page_is_free(virt_to_page(lp))) {
1735 /* The page is "safe", add it to the list */
1736 lp->next = safe_pages_list;
1737 safe_pages_list = lp;
1739 /* Mark the page as allocated */
1740 swsusp_set_page_forbidden(virt_to_page(lp));
1741 swsusp_set_page_free(virt_to_page(lp));
1744 /* Free the reserved safe pages so that chain_alloc() can use them */
1747 free_image_page(sp_list, PG_UNSAFE_CLEAR);
1758 * get_buffer - compute the address that snapshot_write_next() should
1759 * set for its caller to write to.
1762 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
1765 struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
1767 if (PageHighMem(page))
1768 return get_highmem_page_buffer(page, ca);
1770 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
1771 /* We have allocated the "original" page frame and we can
1772 * use it directly to store the loaded page.
1774 return page_address(page);
1776 /* The "original" page frame has not been allocated and we have to
1777 * use a "safe" page frame to store the loaded page.
1779 pbe = chain_alloc(ca, sizeof(struct pbe));
1784 pbe->orig_address = page_address(page);
1785 pbe->address = safe_pages_list;
1786 safe_pages_list = safe_pages_list->next;
1787 pbe->next = restore_pblist;
1788 restore_pblist = pbe;
1789 return pbe->address;
1793 * snapshot_write_next - used for writing the system memory snapshot.
1795 * On the first call to it @handle should point to a zeroed
1796 * snapshot_handle structure. The structure gets updated and a pointer
1797 * to it should be passed to this function every next time.
1799 * The @count parameter should contain the number of bytes the caller
1800 * wants to write to the image. It must not be zero.
1802 * On success the function returns a positive number. Then, the caller
1803 * is allowed to write up to the returned number of bytes to the memory
1804 * location computed by the data_of() macro. The number returned
1805 * may be smaller than @count, but this only happens if the write would
1806 * cross a page boundary otherwise.
1808 * The function returns 0 to indicate the "end of file" condition,
1809 * and a negative number is returned on error. In such cases the
1810 * structure pointed to by @handle is not updated and should not be used
1814 int snapshot_write_next(struct snapshot_handle *handle, size_t count)
1816 static struct chain_allocator ca;
1819 /* Check if we have already loaded the entire image */
1820 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
1823 if (handle->offset == 0) {
1825 /* This makes the buffer be freed by swsusp_free() */
1826 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1831 handle->buffer = buffer;
1833 handle->sync_read = 1;
1834 if (handle->prev < handle->cur) {
1835 if (handle->prev == 0) {
1836 error = load_header(buffer);
1840 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
1844 } else if (handle->prev <= nr_meta_pages) {
1845 unpack_orig_pfns(buffer, ©_bm);
1846 if (handle->prev == nr_meta_pages) {
1847 error = prepare_image(&orig_bm, ©_bm);
1851 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
1852 memory_bm_position_reset(&orig_bm);
1853 restore_pblist = NULL;
1854 handle->buffer = get_buffer(&orig_bm, &ca);
1855 handle->sync_read = 0;
1856 if (!handle->buffer)
1860 copy_last_highmem_page();
1861 handle->buffer = get_buffer(&orig_bm, &ca);
1862 if (handle->buffer != buffer)
1863 handle->sync_read = 0;
1865 handle->prev = handle->cur;
1867 handle->buf_offset = handle->cur_offset;
1868 if (handle->cur_offset + count >= PAGE_SIZE) {
1869 count = PAGE_SIZE - handle->cur_offset;
1870 handle->cur_offset = 0;
1873 handle->cur_offset += count;
1875 handle->offset += count;
1880 * snapshot_write_finalize - must be called after the last call to
1881 * snapshot_write_next() in case the last page in the image happens
1882 * to be a highmem page and its contents should be stored in the
1883 * highmem. Additionally, it releases the memory that will not be
1887 void snapshot_write_finalize(struct snapshot_handle *handle)
1889 copy_last_highmem_page();
1890 /* Free only if we have loaded the image entirely */
1891 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
1892 memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
1893 free_highmem_data();
1897 int snapshot_image_loaded(struct snapshot_handle *handle)
1899 return !(!nr_copy_pages || !last_highmem_page_copied() ||
1900 handle->cur <= nr_meta_pages + nr_copy_pages);
1903 #ifdef CONFIG_HIGHMEM
1904 /* Assumes that @buf is ready and points to a "safe" page */
1906 swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
1908 void *kaddr1, *kaddr2;
1910 kaddr1 = kmap_atomic(p1, KM_USER0);
1911 kaddr2 = kmap_atomic(p2, KM_USER1);
1912 memcpy(buf, kaddr1, PAGE_SIZE);
1913 memcpy(kaddr1, kaddr2, PAGE_SIZE);
1914 memcpy(kaddr2, buf, PAGE_SIZE);
1915 kunmap_atomic(kaddr1, KM_USER0);
1916 kunmap_atomic(kaddr2, KM_USER1);
1920 * restore_highmem - for each highmem page that was allocated before
1921 * the suspend and included in the suspend image, and also has been
1922 * allocated by the "resume" kernel swap its current (ie. "before
1923 * resume") contents with the previous (ie. "before suspend") one.
1925 * If the resume eventually fails, we can call this function once
1926 * again and restore the "before resume" highmem state.
1929 int restore_highmem(void)
1931 struct highmem_pbe *pbe = highmem_pblist;
1937 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
1942 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
1945 free_image_page(buf, PG_UNSAFE_CLEAR);
1948 #endif /* CONFIG_HIGHMEM */