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 */
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