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/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/spinlock.h>
20 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/bootmem.h>
25 #include <linux/syscalls.h>
26 #include <linux/console.h>
27 #include <linux/highmem.h>
29 #include <asm/uaccess.h>
30 #include <asm/mmu_context.h>
31 #include <asm/pgtable.h>
32 #include <asm/tlbflush.h>
37 static int swsusp_page_is_free(struct page *);
38 static void swsusp_set_page_forbidden(struct page *);
39 static void swsusp_unset_page_forbidden(struct page *);
41 /* List of PBEs needed for restoring the pages that were allocated before
42 * the suspend and included in the suspend image, but have also been
43 * allocated by the "resume" kernel, so their contents cannot be written
44 * directly to their "original" page frames.
46 struct pbe *restore_pblist;
48 /* Pointer to an auxiliary buffer (1 page) */
52 * @safe_needed - on resume, for storing the PBE list and the image,
53 * we can only use memory pages that do not conflict with the pages
54 * used before suspend. The unsafe pages have PageNosaveFree set
55 * and we count them using unsafe_pages.
57 * Each allocated image page is marked as PageNosave and PageNosaveFree
58 * so that swsusp_free() can release it.
63 #define PG_UNSAFE_CLEAR 1
64 #define PG_UNSAFE_KEEP 0
66 static unsigned int allocated_unsafe_pages;
68 static void *get_image_page(gfp_t gfp_mask, int safe_needed)
72 res = (void *)get_zeroed_page(gfp_mask);
74 while (res && swsusp_page_is_free(virt_to_page(res))) {
75 /* The page is unsafe, mark it for swsusp_free() */
76 swsusp_set_page_forbidden(virt_to_page(res));
77 allocated_unsafe_pages++;
78 res = (void *)get_zeroed_page(gfp_mask);
81 swsusp_set_page_forbidden(virt_to_page(res));
82 swsusp_set_page_free(virt_to_page(res));
87 unsigned long get_safe_page(gfp_t gfp_mask)
89 return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
92 static struct page *alloc_image_page(gfp_t gfp_mask)
96 page = alloc_page(gfp_mask);
98 swsusp_set_page_forbidden(page);
99 swsusp_set_page_free(page);
105 * free_image_page - free page represented by @addr, allocated with
106 * get_image_page (page flags set by it must be cleared)
109 static inline void free_image_page(void *addr, int clear_nosave_free)
113 BUG_ON(!virt_addr_valid(addr));
115 page = virt_to_page(addr);
117 swsusp_unset_page_forbidden(page);
118 if (clear_nosave_free)
119 swsusp_unset_page_free(page);
124 /* struct linked_page is used to build chains of pages */
126 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
129 struct linked_page *next;
130 char data[LINKED_PAGE_DATA_SIZE];
131 } __attribute__((packed));
134 free_list_of_pages(struct linked_page *list, int clear_page_nosave)
137 struct linked_page *lp = list->next;
139 free_image_page(list, clear_page_nosave);
145 * struct chain_allocator is used for allocating small objects out of
146 * a linked list of pages called 'the chain'.
148 * The chain grows each time when there is no room for a new object in
149 * the current page. The allocated objects cannot be freed individually.
150 * It is only possible to free them all at once, by freeing the entire
153 * NOTE: The chain allocator may be inefficient if the allocated objects
154 * are not much smaller than PAGE_SIZE.
157 struct chain_allocator {
158 struct linked_page *chain; /* the chain */
159 unsigned int used_space; /* total size of objects allocated out
160 * of the current page
162 gfp_t gfp_mask; /* mask for allocating pages */
163 int safe_needed; /* if set, only "safe" pages are allocated */
167 chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
170 ca->used_space = LINKED_PAGE_DATA_SIZE;
171 ca->gfp_mask = gfp_mask;
172 ca->safe_needed = safe_needed;
175 static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
179 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
180 struct linked_page *lp;
182 lp = get_image_page(ca->gfp_mask, ca->safe_needed);
186 lp->next = ca->chain;
190 ret = ca->chain->data + ca->used_space;
191 ca->used_space += size;
195 static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
197 free_list_of_pages(ca->chain, clear_page_nosave);
198 memset(ca, 0, sizeof(struct chain_allocator));
202 * Data types related to memory bitmaps.
204 * Memory bitmap is a structure consiting of many linked lists of
205 * objects. The main list's elements are of type struct zone_bitmap
206 * and each of them corresonds to one zone. For each zone bitmap
207 * object there is a list of objects of type struct bm_block that
208 * represent each blocks of bit chunks in which information is
211 * struct memory_bitmap contains a pointer to the main list of zone
212 * bitmap objects, a struct bm_position used for browsing the bitmap,
213 * and a pointer to the list of pages used for allocating all of the
214 * zone bitmap objects and bitmap block objects.
216 * NOTE: It has to be possible to lay out the bitmap in memory
217 * using only allocations of order 0. Additionally, the bitmap is
218 * designed to work with arbitrary number of zones (this is over the
219 * top for now, but let's avoid making unnecessary assumptions ;-).
221 * struct zone_bitmap contains a pointer to a list of bitmap block
222 * objects and a pointer to the bitmap block object that has been
223 * most recently used for setting bits. Additionally, it contains the
224 * pfns that correspond to the start and end of the represented zone.
226 * struct bm_block contains a pointer to the memory page in which
227 * information is stored (in the form of a block of bit chunks
228 * of type unsigned long each). It also contains the pfns that
229 * correspond to the start and end of the represented memory area and
230 * the number of bit chunks in the block.
233 #define BM_END_OF_MAP (~0UL)
235 #define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long))
236 #define BM_BITS_PER_CHUNK (sizeof(long) << 3)
237 #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3)
240 struct bm_block *next; /* next element of the list */
241 unsigned long start_pfn; /* pfn represented by the first bit */
242 unsigned long end_pfn; /* pfn represented by the last bit plus 1 */
243 unsigned int size; /* number of bit chunks */
244 unsigned long *data; /* chunks of bits representing pages */
248 struct zone_bitmap *next; /* next element of the list */
249 unsigned long start_pfn; /* minimal pfn in this zone */
250 unsigned long end_pfn; /* maximal pfn in this zone plus 1 */
251 struct bm_block *bm_blocks; /* list of bitmap blocks */
252 struct bm_block *cur_block; /* recently used bitmap block */
255 /* strcut bm_position is used for browsing memory bitmaps */
258 struct zone_bitmap *zone_bm;
259 struct bm_block *block;
264 struct memory_bitmap {
265 struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */
266 struct linked_page *p_list; /* list of pages used to store zone
267 * bitmap objects and bitmap block
270 struct bm_position cur; /* most recently used bit position */
273 /* Functions that operate on memory bitmaps */
275 static inline void memory_bm_reset_chunk(struct memory_bitmap *bm)
281 static void memory_bm_position_reset(struct memory_bitmap *bm)
283 struct zone_bitmap *zone_bm;
285 zone_bm = bm->zone_bm_list;
286 bm->cur.zone_bm = zone_bm;
287 bm->cur.block = zone_bm->bm_blocks;
288 memory_bm_reset_chunk(bm);
291 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
294 * create_bm_block_list - create a list of block bitmap objects
297 static inline struct bm_block *
298 create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
300 struct bm_block *bblist = NULL;
302 while (nr_blocks-- > 0) {
305 bb = chain_alloc(ca, sizeof(struct bm_block));
316 * create_zone_bm_list - create a list of zone bitmap objects
319 static inline struct zone_bitmap *
320 create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
322 struct zone_bitmap *zbmlist = NULL;
324 while (nr_zones-- > 0) {
325 struct zone_bitmap *zbm;
327 zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
338 * memory_bm_create - allocate memory for a memory bitmap
342 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
344 struct chain_allocator ca;
346 struct zone_bitmap *zone_bm;
350 chain_init(&ca, gfp_mask, safe_needed);
352 /* Compute the number of zones */
355 if (populated_zone(zone))
358 /* Allocate the list of zones bitmap objects */
359 zone_bm = create_zone_bm_list(nr, &ca);
360 bm->zone_bm_list = zone_bm;
362 chain_free(&ca, PG_UNSAFE_CLEAR);
366 /* Initialize the zone bitmap objects */
367 for_each_zone(zone) {
370 if (!populated_zone(zone))
373 zone_bm->start_pfn = zone->zone_start_pfn;
374 zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages;
375 /* Allocate the list of bitmap block objects */
376 nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
377 bb = create_bm_block_list(nr, &ca);
378 zone_bm->bm_blocks = bb;
379 zone_bm->cur_block = bb;
383 nr = zone->spanned_pages;
384 pfn = zone->zone_start_pfn;
385 /* Initialize the bitmap block objects */
389 ptr = get_image_page(gfp_mask, safe_needed);
395 if (nr >= BM_BITS_PER_BLOCK) {
396 pfn += BM_BITS_PER_BLOCK;
397 bb->size = BM_CHUNKS_PER_BLOCK;
398 nr -= BM_BITS_PER_BLOCK;
400 /* This is executed only once in the loop */
402 bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK);
407 zone_bm = zone_bm->next;
409 bm->p_list = ca.chain;
410 memory_bm_position_reset(bm);
414 bm->p_list = ca.chain;
415 memory_bm_free(bm, PG_UNSAFE_CLEAR);
420 * memory_bm_free - free memory occupied by the memory bitmap @bm
423 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
425 struct zone_bitmap *zone_bm;
427 /* Free the list of bit blocks for each zone_bitmap object */
428 zone_bm = bm->zone_bm_list;
432 bb = zone_bm->bm_blocks;
435 free_image_page(bb->data, clear_nosave_free);
438 zone_bm = zone_bm->next;
440 free_list_of_pages(bm->p_list, clear_nosave_free);
441 bm->zone_bm_list = NULL;
445 * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
446 * to given pfn. The cur_zone_bm member of @bm and the cur_block member
447 * of @bm->cur_zone_bm are updated.
450 static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
451 void **addr, unsigned int *bit_nr)
453 struct zone_bitmap *zone_bm;
456 /* Check if the pfn is from the current zone */
457 zone_bm = bm->cur.zone_bm;
458 if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
459 zone_bm = bm->zone_bm_list;
460 /* We don't assume that the zones are sorted by pfns */
461 while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
462 zone_bm = zone_bm->next;
466 bm->cur.zone_bm = zone_bm;
468 /* Check if the pfn corresponds to the current bitmap block */
469 bb = zone_bm->cur_block;
470 if (pfn < bb->start_pfn)
471 bb = zone_bm->bm_blocks;
473 while (pfn >= bb->end_pfn) {
478 zone_bm->cur_block = bb;
479 pfn -= bb->start_pfn;
480 *bit_nr = pfn % BM_BITS_PER_CHUNK;
481 *addr = bb->data + pfn / BM_BITS_PER_CHUNK;
484 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
489 memory_bm_find_bit(bm, pfn, &addr, &bit);
493 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
498 memory_bm_find_bit(bm, pfn, &addr, &bit);
499 clear_bit(bit, addr);
502 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
507 memory_bm_find_bit(bm, pfn, &addr, &bit);
508 return test_bit(bit, addr);
511 /* Two auxiliary functions for memory_bm_next_pfn */
513 /* Find the first set bit in the given chunk, if there is one */
515 static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
518 while (bit < BM_BITS_PER_CHUNK) {
519 if (test_bit(bit, chunk_p))
527 /* Find a chunk containing some bits set in given block of bits */
529 static inline int next_chunk_in_block(int n, struct bm_block *bb)
532 while (n < bb->size) {
542 * memory_bm_next_pfn - find the pfn that corresponds to the next set bit
543 * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
546 * It is required to run memory_bm_position_reset() before the first call to
550 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
552 struct zone_bitmap *zone_bm;
560 chunk = bm->cur.chunk;
563 bit = next_bit_in_chunk(bit, bb->data + chunk);
567 chunk = next_chunk_in_block(chunk, bb);
569 } while (chunk >= 0);
572 memory_bm_reset_chunk(bm);
574 zone_bm = bm->cur.zone_bm->next;
576 bm->cur.zone_bm = zone_bm;
577 bm->cur.block = zone_bm->bm_blocks;
578 memory_bm_reset_chunk(bm);
581 memory_bm_position_reset(bm);
582 return BM_END_OF_MAP;
585 bm->cur.chunk = chunk;
587 return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit;
591 * This structure represents a range of page frames the contents of which
592 * should not be saved during the suspend.
595 struct nosave_region {
596 struct list_head list;
597 unsigned long start_pfn;
598 unsigned long end_pfn;
601 static LIST_HEAD(nosave_regions);
604 * register_nosave_region - register a range of page frames the contents
605 * of which should not be saved during the suspend (to be used in the early
606 * initialization code)
610 register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
612 struct nosave_region *region;
614 if (start_pfn >= end_pfn)
617 if (!list_empty(&nosave_regions)) {
618 /* Try to extend the previous region (they should be sorted) */
619 region = list_entry(nosave_regions.prev,
620 struct nosave_region, list);
621 if (region->end_pfn == start_pfn) {
622 region->end_pfn = end_pfn;
626 /* This allocation cannot fail */
627 region = alloc_bootmem_low(sizeof(struct nosave_region));
628 region->start_pfn = start_pfn;
629 region->end_pfn = end_pfn;
630 list_add_tail(®ion->list, &nosave_regions);
632 printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
633 start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
637 * Set bits in this map correspond to the page frames the contents of which
638 * should not be saved during the suspend.
640 static struct memory_bitmap *forbidden_pages_map;
642 /* Set bits in this map correspond to free page frames. */
643 static struct memory_bitmap *free_pages_map;
646 * Each page frame allocated for creating the image is marked by setting the
647 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
650 void swsusp_set_page_free(struct page *page)
653 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
656 static int swsusp_page_is_free(struct page *page)
658 return free_pages_map ?
659 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
662 void swsusp_unset_page_free(struct page *page)
665 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
668 static void swsusp_set_page_forbidden(struct page *page)
670 if (forbidden_pages_map)
671 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
674 int swsusp_page_is_forbidden(struct page *page)
676 return forbidden_pages_map ?
677 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
680 static void swsusp_unset_page_forbidden(struct page *page)
682 if (forbidden_pages_map)
683 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
687 * mark_nosave_pages - set bits corresponding to the page frames the
688 * contents of which should not be saved in a given bitmap.
691 static void mark_nosave_pages(struct memory_bitmap *bm)
693 struct nosave_region *region;
695 if (list_empty(&nosave_regions))
698 list_for_each_entry(region, &nosave_regions, list) {
701 printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
702 region->start_pfn << PAGE_SHIFT,
703 region->end_pfn << PAGE_SHIFT);
705 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
706 memory_bm_set_bit(bm, pfn);
711 * create_basic_memory_bitmaps - create bitmaps needed for marking page
712 * frames that should not be saved and free page frames. The pointers
713 * forbidden_pages_map and free_pages_map are only modified if everything
714 * goes well, because we don't want the bits to be used before both bitmaps
718 int create_basic_memory_bitmaps(void)
720 struct memory_bitmap *bm1, *bm2;
723 BUG_ON(forbidden_pages_map || free_pages_map);
725 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
729 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
731 goto Free_first_object;
733 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
735 goto Free_first_bitmap;
737 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
739 goto Free_second_object;
741 forbidden_pages_map = bm1;
742 free_pages_map = bm2;
743 mark_nosave_pages(forbidden_pages_map);
745 printk("swsusp: Basic memory bitmaps created\n");
752 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
759 * free_basic_memory_bitmaps - free memory bitmaps allocated by
760 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
761 * so that the bitmaps themselves are not referred to while they are being
765 void free_basic_memory_bitmaps(void)
767 struct memory_bitmap *bm1, *bm2;
769 BUG_ON(!(forbidden_pages_map && free_pages_map));
771 bm1 = forbidden_pages_map;
772 bm2 = free_pages_map;
773 forbidden_pages_map = NULL;
774 free_pages_map = NULL;
775 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
777 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
780 printk("swsusp: Basic memory bitmaps freed\n");
784 * snapshot_additional_pages - estimate the number of additional pages
785 * be needed for setting up the suspend image data structures for given
786 * zone (usually the returned value is greater than the exact number)
789 unsigned int snapshot_additional_pages(struct zone *zone)
793 res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
794 res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
798 #ifdef CONFIG_HIGHMEM
800 * count_free_highmem_pages - compute the total number of free highmem
801 * pages, system-wide.
804 static unsigned int count_free_highmem_pages(void)
807 unsigned int cnt = 0;
810 if (populated_zone(zone) && is_highmem(zone))
811 cnt += zone_page_state(zone, NR_FREE_PAGES);
817 * saveable_highmem_page - Determine whether a highmem page should be
818 * included in the suspend image.
820 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
821 * and it isn't a part of a free chunk of pages.
824 static struct page *saveable_highmem_page(unsigned long pfn)
831 page = pfn_to_page(pfn);
833 BUG_ON(!PageHighMem(page));
835 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
843 * count_highmem_pages - compute the total number of saveable highmem
847 unsigned int count_highmem_pages(void)
852 for_each_zone(zone) {
853 unsigned long pfn, max_zone_pfn;
855 if (!is_highmem(zone))
858 mark_free_pages(zone);
859 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
860 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
861 if (saveable_highmem_page(pfn))
867 static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
868 static inline unsigned int count_highmem_pages(void) { return 0; }
869 #endif /* CONFIG_HIGHMEM */
872 * saveable - Determine whether a non-highmem page should be included in
875 * We should save the page if it isn't Nosave, and is not in the range
876 * of pages statically defined as 'unsaveable', and it isn't a part of
877 * a free chunk of pages.
880 static struct page *saveable_page(unsigned long pfn)
887 page = pfn_to_page(pfn);
889 BUG_ON(PageHighMem(page));
891 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
894 if (PageReserved(page) && pfn_is_nosave(pfn))
901 * count_data_pages - compute the total number of saveable non-highmem
905 unsigned int count_data_pages(void)
908 unsigned long pfn, max_zone_pfn;
911 for_each_zone(zone) {
912 if (is_highmem(zone))
915 mark_free_pages(zone);
916 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
917 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
918 if(saveable_page(pfn))
924 /* This is needed, because copy_page and memcpy are not usable for copying
927 static inline void do_copy_page(long *dst, long *src)
931 for (n = PAGE_SIZE / sizeof(long); n; n--)
935 #ifdef CONFIG_HIGHMEM
936 static inline struct page *
937 page_is_saveable(struct zone *zone, unsigned long pfn)
939 return is_highmem(zone) ?
940 saveable_highmem_page(pfn) : saveable_page(pfn);
944 copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
946 struct page *s_page, *d_page;
949 s_page = pfn_to_page(src_pfn);
950 d_page = pfn_to_page(dst_pfn);
951 if (PageHighMem(s_page)) {
952 src = kmap_atomic(s_page, KM_USER0);
953 dst = kmap_atomic(d_page, KM_USER1);
954 do_copy_page(dst, src);
955 kunmap_atomic(src, KM_USER0);
956 kunmap_atomic(dst, KM_USER1);
958 src = page_address(s_page);
959 if (PageHighMem(d_page)) {
960 /* Page pointed to by src may contain some kernel
961 * data modified by kmap_atomic()
963 do_copy_page(buffer, src);
964 dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
965 memcpy(dst, buffer, PAGE_SIZE);
966 kunmap_atomic(dst, KM_USER0);
968 dst = page_address(d_page);
969 do_copy_page(dst, src);
974 #define page_is_saveable(zone, pfn) saveable_page(pfn)
977 copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
979 do_copy_page(page_address(pfn_to_page(dst_pfn)),
980 page_address(pfn_to_page(src_pfn)));
982 #endif /* CONFIG_HIGHMEM */
985 copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
990 for_each_zone(zone) {
991 unsigned long max_zone_pfn;
993 mark_free_pages(zone);
994 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
995 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
996 if (page_is_saveable(zone, pfn))
997 memory_bm_set_bit(orig_bm, pfn);
999 memory_bm_position_reset(orig_bm);
1000 memory_bm_position_reset(copy_bm);
1002 pfn = memory_bm_next_pfn(orig_bm);
1003 if (likely(pfn != BM_END_OF_MAP))
1004 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1005 } while (pfn != BM_END_OF_MAP);
1008 /* Total number of image pages */
1009 static unsigned int nr_copy_pages;
1010 /* Number of pages needed for saving the original pfns of the image pages */
1011 static unsigned int nr_meta_pages;
1014 * swsusp_free - free pages allocated for the suspend.
1016 * Suspend pages are alocated before the atomic copy is made, so we
1017 * need to release them after the resume.
1020 void swsusp_free(void)
1023 unsigned long pfn, max_zone_pfn;
1025 for_each_zone(zone) {
1026 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1027 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1028 if (pfn_valid(pfn)) {
1029 struct page *page = pfn_to_page(pfn);
1031 if (swsusp_page_is_forbidden(page) &&
1032 swsusp_page_is_free(page)) {
1033 swsusp_unset_page_forbidden(page);
1034 swsusp_unset_page_free(page);
1041 restore_pblist = NULL;
1045 #ifdef CONFIG_HIGHMEM
1047 * count_pages_for_highmem - compute the number of non-highmem pages
1048 * that will be necessary for creating copies of highmem pages.
1051 static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1053 unsigned int free_highmem = count_free_highmem_pages();
1055 if (free_highmem >= nr_highmem)
1058 nr_highmem -= free_highmem;
1064 count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1065 #endif /* CONFIG_HIGHMEM */
1068 * enough_free_mem - Make sure we have enough free memory for the
1072 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1075 unsigned int free = 0, meta = 0;
1077 for_each_zone(zone) {
1078 meta += snapshot_additional_pages(zone);
1079 if (!is_highmem(zone))
1080 free += zone_page_state(zone, NR_FREE_PAGES);
1083 nr_pages += count_pages_for_highmem(nr_highmem);
1084 pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
1085 nr_pages, PAGES_FOR_IO, meta, free);
1087 return free > nr_pages + PAGES_FOR_IO + meta;
1090 #ifdef CONFIG_HIGHMEM
1092 * get_highmem_buffer - if there are some highmem pages in the suspend
1093 * image, we may need the buffer to copy them and/or load their data.
1096 static inline int get_highmem_buffer(int safe_needed)
1098 buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
1099 return buffer ? 0 : -ENOMEM;
1103 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1104 * Try to allocate as many pages as needed, but if the number of free
1105 * highmem pages is lesser than that, allocate them all.
1108 static inline unsigned int
1109 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
1111 unsigned int to_alloc = count_free_highmem_pages();
1113 if (to_alloc > nr_highmem)
1114 to_alloc = nr_highmem;
1116 nr_highmem -= to_alloc;
1117 while (to_alloc-- > 0) {
1120 page = alloc_image_page(__GFP_HIGHMEM);
1121 memory_bm_set_bit(bm, page_to_pfn(page));
1126 static inline int get_highmem_buffer(int safe_needed) { return 0; }
1128 static inline unsigned int
1129 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
1130 #endif /* CONFIG_HIGHMEM */
1133 * swsusp_alloc - allocate memory for the suspend image
1135 * We first try to allocate as many highmem pages as there are
1136 * saveable highmem pages in the system. If that fails, we allocate
1137 * non-highmem pages for the copies of the remaining highmem ones.
1139 * In this approach it is likely that the copies of highmem pages will
1140 * also be located in the high memory, because of the way in which
1141 * copy_data_pages() works.
1145 swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
1146 unsigned int nr_pages, unsigned int nr_highmem)
1150 error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1154 error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1158 if (nr_highmem > 0) {
1159 error = get_highmem_buffer(PG_ANY);
1163 nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem);
1165 while (nr_pages-- > 0) {
1166 struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
1171 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1180 /* Memory bitmap used for marking saveable pages (during suspend) or the
1181 * suspend image pages (during resume)
1183 static struct memory_bitmap orig_bm;
1184 /* Memory bitmap used on suspend for marking allocated pages that will contain
1185 * the copies of saveable pages. During resume it is initially used for
1186 * marking the suspend image pages, but then its set bits are duplicated in
1187 * @orig_bm and it is released. Next, on systems with high memory, it may be
1188 * used for marking "safe" highmem pages, but it has to be reinitialized for
1191 static struct memory_bitmap copy_bm;
1193 asmlinkage int swsusp_save(void)
1195 unsigned int nr_pages, nr_highmem;
1197 printk("swsusp: critical section: \n");
1199 drain_local_pages();
1200 nr_pages = count_data_pages();
1201 nr_highmem = count_highmem_pages();
1202 printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem);
1204 if (!enough_free_mem(nr_pages, nr_highmem)) {
1205 printk(KERN_ERR "swsusp: Not enough free memory\n");
1209 if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) {
1210 printk(KERN_ERR "swsusp: Memory allocation failed\n");
1214 /* During allocating of suspend pagedir, new cold pages may appear.
1217 drain_local_pages();
1218 copy_data_pages(©_bm, &orig_bm);
1221 * End of critical section. From now on, we can write to memory,
1222 * but we should not touch disk. This specially means we must _not_
1223 * touch swap space! Except we must write out our image of course.
1226 nr_pages += nr_highmem;
1227 nr_copy_pages = nr_pages;
1228 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
1230 printk("swsusp: critical section: done (%d pages copied)\n", nr_pages);
1235 static void init_header(struct swsusp_info *info)
1237 memset(info, 0, sizeof(struct swsusp_info));
1238 info->version_code = LINUX_VERSION_CODE;
1239 info->num_physpages = num_physpages;
1240 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
1241 info->cpus = num_online_cpus();
1242 info->image_pages = nr_copy_pages;
1243 info->pages = nr_copy_pages + nr_meta_pages + 1;
1244 info->size = info->pages;
1245 info->size <<= PAGE_SHIFT;
1249 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1250 * are stored in the array @buf[] (1 page at a time)
1254 pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
1258 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1259 buf[j] = memory_bm_next_pfn(bm);
1260 if (unlikely(buf[j] == BM_END_OF_MAP))
1266 * snapshot_read_next - used for reading the system memory snapshot.
1268 * On the first call to it @handle should point to a zeroed
1269 * snapshot_handle structure. The structure gets updated and a pointer
1270 * to it should be passed to this function every next time.
1272 * The @count parameter should contain the number of bytes the caller
1273 * wants to read from the snapshot. It must not be zero.
1275 * On success the function returns a positive number. Then, the caller
1276 * is allowed to read up to the returned number of bytes from the memory
1277 * location computed by the data_of() macro. The number returned
1278 * may be smaller than @count, but this only happens if the read would
1279 * cross a page boundary otherwise.
1281 * The function returns 0 to indicate the end of data stream condition,
1282 * and a negative number is returned on error. In such cases the
1283 * structure pointed to by @handle is not updated and should not be used
1287 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
1289 if (handle->cur > nr_meta_pages + nr_copy_pages)
1293 /* This makes the buffer be freed by swsusp_free() */
1294 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1298 if (!handle->offset) {
1299 init_header((struct swsusp_info *)buffer);
1300 handle->buffer = buffer;
1301 memory_bm_position_reset(&orig_bm);
1302 memory_bm_position_reset(©_bm);
1304 if (handle->prev < handle->cur) {
1305 if (handle->cur <= nr_meta_pages) {
1306 memset(buffer, 0, PAGE_SIZE);
1307 pack_pfns(buffer, &orig_bm);
1311 page = pfn_to_page(memory_bm_next_pfn(©_bm));
1312 if (PageHighMem(page)) {
1313 /* Highmem pages are copied to the buffer,
1314 * because we can't return with a kmapped
1315 * highmem page (we may not be called again).
1319 kaddr = kmap_atomic(page, KM_USER0);
1320 memcpy(buffer, kaddr, PAGE_SIZE);
1321 kunmap_atomic(kaddr, KM_USER0);
1322 handle->buffer = buffer;
1324 handle->buffer = page_address(page);
1327 handle->prev = handle->cur;
1329 handle->buf_offset = handle->cur_offset;
1330 if (handle->cur_offset + count >= PAGE_SIZE) {
1331 count = PAGE_SIZE - handle->cur_offset;
1332 handle->cur_offset = 0;
1335 handle->cur_offset += count;
1337 handle->offset += count;
1342 * mark_unsafe_pages - mark the pages that cannot be used for storing
1343 * the image during resume, because they conflict with the pages that
1344 * had been used before suspend
1347 static int mark_unsafe_pages(struct memory_bitmap *bm)
1350 unsigned long pfn, max_zone_pfn;
1352 /* Clear page flags */
1353 for_each_zone(zone) {
1354 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1355 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1357 swsusp_unset_page_free(pfn_to_page(pfn));
1360 /* Mark pages that correspond to the "original" pfns as "unsafe" */
1361 memory_bm_position_reset(bm);
1363 pfn = memory_bm_next_pfn(bm);
1364 if (likely(pfn != BM_END_OF_MAP)) {
1365 if (likely(pfn_valid(pfn)))
1366 swsusp_set_page_free(pfn_to_page(pfn));
1370 } while (pfn != BM_END_OF_MAP);
1372 allocated_unsafe_pages = 0;
1378 duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
1382 memory_bm_position_reset(src);
1383 pfn = memory_bm_next_pfn(src);
1384 while (pfn != BM_END_OF_MAP) {
1385 memory_bm_set_bit(dst, pfn);
1386 pfn = memory_bm_next_pfn(src);
1390 static inline int check_header(struct swsusp_info *info)
1392 char *reason = NULL;
1394 if (info->version_code != LINUX_VERSION_CODE)
1395 reason = "kernel version";
1396 if (info->num_physpages != num_physpages)
1397 reason = "memory size";
1398 if (strcmp(info->uts.sysname,init_utsname()->sysname))
1399 reason = "system type";
1400 if (strcmp(info->uts.release,init_utsname()->release))
1401 reason = "kernel release";
1402 if (strcmp(info->uts.version,init_utsname()->version))
1404 if (strcmp(info->uts.machine,init_utsname()->machine))
1407 printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
1414 * load header - check the image header and copy data from it
1418 load_header(struct swsusp_info *info)
1422 restore_pblist = NULL;
1423 error = check_header(info);
1425 nr_copy_pages = info->image_pages;
1426 nr_meta_pages = info->pages - info->image_pages - 1;
1432 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1433 * the corresponding bit in the memory bitmap @bm
1437 unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
1441 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1442 if (unlikely(buf[j] == BM_END_OF_MAP))
1445 memory_bm_set_bit(bm, buf[j]);
1449 /* List of "safe" pages that may be used to store data loaded from the suspend
1452 static struct linked_page *safe_pages_list;
1454 #ifdef CONFIG_HIGHMEM
1455 /* struct highmem_pbe is used for creating the list of highmem pages that
1456 * should be restored atomically during the resume from disk, because the page
1457 * frames they have occupied before the suspend are in use.
1459 struct highmem_pbe {
1460 struct page *copy_page; /* data is here now */
1461 struct page *orig_page; /* data was here before the suspend */
1462 struct highmem_pbe *next;
1465 /* List of highmem PBEs needed for restoring the highmem pages that were
1466 * allocated before the suspend and included in the suspend image, but have
1467 * also been allocated by the "resume" kernel, so their contents cannot be
1468 * written directly to their "original" page frames.
1470 static struct highmem_pbe *highmem_pblist;
1473 * count_highmem_image_pages - compute the number of highmem pages in the
1474 * suspend image. The bits in the memory bitmap @bm that correspond to the
1475 * image pages are assumed to be set.
1478 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
1481 unsigned int cnt = 0;
1483 memory_bm_position_reset(bm);
1484 pfn = memory_bm_next_pfn(bm);
1485 while (pfn != BM_END_OF_MAP) {
1486 if (PageHighMem(pfn_to_page(pfn)))
1489 pfn = memory_bm_next_pfn(bm);
1495 * prepare_highmem_image - try to allocate as many highmem pages as
1496 * there are highmem image pages (@nr_highmem_p points to the variable
1497 * containing the number of highmem image pages). The pages that are
1498 * "safe" (ie. will not be overwritten when the suspend image is
1499 * restored) have the corresponding bits set in @bm (it must be
1502 * NOTE: This function should not be called if there are no highmem
1506 static unsigned int safe_highmem_pages;
1508 static struct memory_bitmap *safe_highmem_bm;
1511 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1513 unsigned int to_alloc;
1515 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
1518 if (get_highmem_buffer(PG_SAFE))
1521 to_alloc = count_free_highmem_pages();
1522 if (to_alloc > *nr_highmem_p)
1523 to_alloc = *nr_highmem_p;
1525 *nr_highmem_p = to_alloc;
1527 safe_highmem_pages = 0;
1528 while (to_alloc-- > 0) {
1531 page = alloc_page(__GFP_HIGHMEM);
1532 if (!swsusp_page_is_free(page)) {
1533 /* The page is "safe", set its bit the bitmap */
1534 memory_bm_set_bit(bm, page_to_pfn(page));
1535 safe_highmem_pages++;
1537 /* Mark the page as allocated */
1538 swsusp_set_page_forbidden(page);
1539 swsusp_set_page_free(page);
1541 memory_bm_position_reset(bm);
1542 safe_highmem_bm = bm;
1547 * get_highmem_page_buffer - for given highmem image page find the buffer
1548 * that suspend_write_next() should set for its caller to write to.
1550 * If the page is to be saved to its "original" page frame or a copy of
1551 * the page is to be made in the highmem, @buffer is returned. Otherwise,
1552 * the copy of the page is to be made in normal memory, so the address of
1553 * the copy is returned.
1555 * If @buffer is returned, the caller of suspend_write_next() will write
1556 * the page's contents to @buffer, so they will have to be copied to the
1557 * right location on the next call to suspend_write_next() and it is done
1558 * with the help of copy_last_highmem_page(). For this purpose, if
1559 * @buffer is returned, @last_highmem page is set to the page to which
1560 * the data will have to be copied from @buffer.
1563 static struct page *last_highmem_page;
1566 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1568 struct highmem_pbe *pbe;
1571 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
1572 /* We have allocated the "original" page frame and we can
1573 * use it directly to store the loaded page.
1575 last_highmem_page = page;
1578 /* The "original" page frame has not been allocated and we have to
1579 * use a "safe" page frame to store the loaded page.
1581 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
1586 pbe->orig_page = page;
1587 if (safe_highmem_pages > 0) {
1590 /* Copy of the page will be stored in high memory */
1592 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
1593 safe_highmem_pages--;
1594 last_highmem_page = tmp;
1595 pbe->copy_page = tmp;
1597 /* Copy of the page will be stored in normal memory */
1598 kaddr = safe_pages_list;
1599 safe_pages_list = safe_pages_list->next;
1600 pbe->copy_page = virt_to_page(kaddr);
1602 pbe->next = highmem_pblist;
1603 highmem_pblist = pbe;
1608 * copy_last_highmem_page - copy the contents of a highmem image from
1609 * @buffer, where the caller of snapshot_write_next() has place them,
1610 * to the right location represented by @last_highmem_page .
1613 static void copy_last_highmem_page(void)
1615 if (last_highmem_page) {
1618 dst = kmap_atomic(last_highmem_page, KM_USER0);
1619 memcpy(dst, buffer, PAGE_SIZE);
1620 kunmap_atomic(dst, KM_USER0);
1621 last_highmem_page = NULL;
1625 static inline int last_highmem_page_copied(void)
1627 return !last_highmem_page;
1630 static inline void free_highmem_data(void)
1632 if (safe_highmem_bm)
1633 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
1636 free_image_page(buffer, PG_UNSAFE_CLEAR);
1639 static inline int get_safe_write_buffer(void) { return 0; }
1642 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
1645 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1650 static inline void *
1651 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1656 static inline void copy_last_highmem_page(void) {}
1657 static inline int last_highmem_page_copied(void) { return 1; }
1658 static inline void free_highmem_data(void) {}
1659 #endif /* CONFIG_HIGHMEM */
1662 * prepare_image - use the memory bitmap @bm to mark the pages that will
1663 * be overwritten in the process of restoring the system memory state
1664 * from the suspend image ("unsafe" pages) and allocate memory for the
1667 * The idea is to allocate a new memory bitmap first and then allocate
1668 * as many pages as needed for the image data, but not to assign these
1669 * pages to specific tasks initially. Instead, we just mark them as
1670 * allocated and create a lists of "safe" pages that will be used
1671 * later. On systems with high memory a list of "safe" highmem pages is
1675 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
1678 prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
1680 unsigned int nr_pages, nr_highmem;
1681 struct linked_page *sp_list, *lp;
1684 /* If there is no highmem, the buffer will not be necessary */
1685 free_image_page(buffer, PG_UNSAFE_CLEAR);
1688 nr_highmem = count_highmem_image_pages(bm);
1689 error = mark_unsafe_pages(bm);
1693 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
1697 duplicate_memory_bitmap(new_bm, bm);
1698 memory_bm_free(bm, PG_UNSAFE_KEEP);
1699 if (nr_highmem > 0) {
1700 error = prepare_highmem_image(bm, &nr_highmem);
1704 /* Reserve some safe pages for potential later use.
1706 * NOTE: This way we make sure there will be enough safe pages for the
1707 * chain_alloc() in get_buffer(). It is a bit wasteful, but
1708 * nr_copy_pages cannot be greater than 50% of the memory anyway.
1711 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
1712 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1713 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
1714 while (nr_pages > 0) {
1715 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
1724 /* Preallocate memory for the image */
1725 safe_pages_list = NULL;
1726 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1727 while (nr_pages > 0) {
1728 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
1733 if (!swsusp_page_is_free(virt_to_page(lp))) {
1734 /* The page is "safe", add it to the list */
1735 lp->next = safe_pages_list;
1736 safe_pages_list = lp;
1738 /* Mark the page as allocated */
1739 swsusp_set_page_forbidden(virt_to_page(lp));
1740 swsusp_set_page_free(virt_to_page(lp));
1743 /* Free the reserved safe pages so that chain_alloc() can use them */
1746 free_image_page(sp_list, PG_UNSAFE_CLEAR);
1757 * get_buffer - compute the address that snapshot_write_next() should
1758 * set for its caller to write to.
1761 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
1764 struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
1766 if (PageHighMem(page))
1767 return get_highmem_page_buffer(page, ca);
1769 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
1770 /* We have allocated the "original" page frame and we can
1771 * use it directly to store the loaded page.
1773 return page_address(page);
1775 /* The "original" page frame has not been allocated and we have to
1776 * use a "safe" page frame to store the loaded page.
1778 pbe = chain_alloc(ca, sizeof(struct pbe));
1783 pbe->orig_address = page_address(page);
1784 pbe->address = safe_pages_list;
1785 safe_pages_list = safe_pages_list->next;
1786 pbe->next = restore_pblist;
1787 restore_pblist = pbe;
1788 return pbe->address;
1792 * snapshot_write_next - used for writing the system memory snapshot.
1794 * On the first call to it @handle should point to a zeroed
1795 * snapshot_handle structure. The structure gets updated and a pointer
1796 * to it should be passed to this function every next time.
1798 * The @count parameter should contain the number of bytes the caller
1799 * wants to write to the image. It must not be zero.
1801 * On success the function returns a positive number. Then, the caller
1802 * is allowed to write up to the returned number of bytes to the memory
1803 * location computed by the data_of() macro. The number returned
1804 * may be smaller than @count, but this only happens if the write would
1805 * cross a page boundary otherwise.
1807 * The function returns 0 to indicate the "end of file" condition,
1808 * and a negative number is returned on error. In such cases the
1809 * structure pointed to by @handle is not updated and should not be used
1813 int snapshot_write_next(struct snapshot_handle *handle, size_t count)
1815 static struct chain_allocator ca;
1818 /* Check if we have already loaded the entire image */
1819 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
1822 if (handle->offset == 0) {
1824 /* This makes the buffer be freed by swsusp_free() */
1825 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1830 handle->buffer = buffer;
1832 handle->sync_read = 1;
1833 if (handle->prev < handle->cur) {
1834 if (handle->prev == 0) {
1835 error = load_header(buffer);
1839 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
1843 } else if (handle->prev <= nr_meta_pages) {
1844 unpack_orig_pfns(buffer, ©_bm);
1845 if (handle->prev == nr_meta_pages) {
1846 error = prepare_image(&orig_bm, ©_bm);
1850 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
1851 memory_bm_position_reset(&orig_bm);
1852 restore_pblist = NULL;
1853 handle->buffer = get_buffer(&orig_bm, &ca);
1854 handle->sync_read = 0;
1855 if (!handle->buffer)
1859 copy_last_highmem_page();
1860 handle->buffer = get_buffer(&orig_bm, &ca);
1861 if (handle->buffer != buffer)
1862 handle->sync_read = 0;
1864 handle->prev = handle->cur;
1866 handle->buf_offset = handle->cur_offset;
1867 if (handle->cur_offset + count >= PAGE_SIZE) {
1868 count = PAGE_SIZE - handle->cur_offset;
1869 handle->cur_offset = 0;
1872 handle->cur_offset += count;
1874 handle->offset += count;
1879 * snapshot_write_finalize - must be called after the last call to
1880 * snapshot_write_next() in case the last page in the image happens
1881 * to be a highmem page and its contents should be stored in the
1882 * highmem. Additionally, it releases the memory that will not be
1886 void snapshot_write_finalize(struct snapshot_handle *handle)
1888 copy_last_highmem_page();
1889 /* Free only if we have loaded the image entirely */
1890 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
1891 memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
1892 free_highmem_data();
1896 int snapshot_image_loaded(struct snapshot_handle *handle)
1898 return !(!nr_copy_pages || !last_highmem_page_copied() ||
1899 handle->cur <= nr_meta_pages + nr_copy_pages);
1902 #ifdef CONFIG_HIGHMEM
1903 /* Assumes that @buf is ready and points to a "safe" page */
1905 swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
1907 void *kaddr1, *kaddr2;
1909 kaddr1 = kmap_atomic(p1, KM_USER0);
1910 kaddr2 = kmap_atomic(p2, KM_USER1);
1911 memcpy(buf, kaddr1, PAGE_SIZE);
1912 memcpy(kaddr1, kaddr2, PAGE_SIZE);
1913 memcpy(kaddr2, buf, PAGE_SIZE);
1914 kunmap_atomic(kaddr1, KM_USER0);
1915 kunmap_atomic(kaddr2, KM_USER1);
1919 * restore_highmem - for each highmem page that was allocated before
1920 * the suspend and included in the suspend image, and also has been
1921 * allocated by the "resume" kernel swap its current (ie. "before
1922 * resume") contents with the previous (ie. "before suspend") one.
1924 * If the resume eventually fails, we can call this function once
1925 * again and restore the "before resume" highmem state.
1928 int restore_highmem(void)
1930 struct highmem_pbe *pbe = highmem_pblist;
1936 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
1941 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
1944 free_image_page(buf, PG_UNSAFE_CLEAR);
1947 #endif /* CONFIG_HIGHMEM */