]>
git.proxmox.com Git - mirror_ubuntu-kernels.git/blob - kernel/power/snapshot.c
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
,
613 struct nosave_region
*region
;
615 if (start_pfn
>= end_pfn
)
618 if (!list_empty(&nosave_regions
)) {
619 /* Try to extend the previous region (they should be sorted) */
620 region
= list_entry(nosave_regions
.prev
,
621 struct nosave_region
, list
);
622 if (region
->end_pfn
== start_pfn
) {
623 region
->end_pfn
= end_pfn
;
628 /* during init, this shouldn't fail */
629 region
= kmalloc(sizeof(struct nosave_region
), GFP_KERNEL
);
632 /* This allocation cannot fail */
633 region
= alloc_bootmem_low(sizeof(struct nosave_region
));
634 region
->start_pfn
= start_pfn
;
635 region
->end_pfn
= end_pfn
;
636 list_add_tail(®ion
->list
, &nosave_regions
);
638 printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
639 start_pfn
<< PAGE_SHIFT
, end_pfn
<< PAGE_SHIFT
);
643 * Set bits in this map correspond to the page frames the contents of which
644 * should not be saved during the suspend.
646 static struct memory_bitmap
*forbidden_pages_map
;
648 /* Set bits in this map correspond to free page frames. */
649 static struct memory_bitmap
*free_pages_map
;
652 * Each page frame allocated for creating the image is marked by setting the
653 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
656 void swsusp_set_page_free(struct page
*page
)
659 memory_bm_set_bit(free_pages_map
, page_to_pfn(page
));
662 static int swsusp_page_is_free(struct page
*page
)
664 return free_pages_map
?
665 memory_bm_test_bit(free_pages_map
, page_to_pfn(page
)) : 0;
668 void swsusp_unset_page_free(struct page
*page
)
671 memory_bm_clear_bit(free_pages_map
, page_to_pfn(page
));
674 static void swsusp_set_page_forbidden(struct page
*page
)
676 if (forbidden_pages_map
)
677 memory_bm_set_bit(forbidden_pages_map
, page_to_pfn(page
));
680 int swsusp_page_is_forbidden(struct page
*page
)
682 return forbidden_pages_map
?
683 memory_bm_test_bit(forbidden_pages_map
, page_to_pfn(page
)) : 0;
686 static void swsusp_unset_page_forbidden(struct page
*page
)
688 if (forbidden_pages_map
)
689 memory_bm_clear_bit(forbidden_pages_map
, page_to_pfn(page
));
693 * mark_nosave_pages - set bits corresponding to the page frames the
694 * contents of which should not be saved in a given bitmap.
697 static void mark_nosave_pages(struct memory_bitmap
*bm
)
699 struct nosave_region
*region
;
701 if (list_empty(&nosave_regions
))
704 list_for_each_entry(region
, &nosave_regions
, list
) {
707 printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
708 region
->start_pfn
<< PAGE_SHIFT
,
709 region
->end_pfn
<< PAGE_SHIFT
);
711 for (pfn
= region
->start_pfn
; pfn
< region
->end_pfn
; pfn
++)
713 memory_bm_set_bit(bm
, pfn
);
718 * create_basic_memory_bitmaps - create bitmaps needed for marking page
719 * frames that should not be saved and free page frames. The pointers
720 * forbidden_pages_map and free_pages_map are only modified if everything
721 * goes well, because we don't want the bits to be used before both bitmaps
725 int create_basic_memory_bitmaps(void)
727 struct memory_bitmap
*bm1
, *bm2
;
730 BUG_ON(forbidden_pages_map
|| free_pages_map
);
732 bm1
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
736 error
= memory_bm_create(bm1
, GFP_KERNEL
, PG_ANY
);
738 goto Free_first_object
;
740 bm2
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
742 goto Free_first_bitmap
;
744 error
= memory_bm_create(bm2
, GFP_KERNEL
, PG_ANY
);
746 goto Free_second_object
;
748 forbidden_pages_map
= bm1
;
749 free_pages_map
= bm2
;
750 mark_nosave_pages(forbidden_pages_map
);
752 printk("swsusp: Basic memory bitmaps created\n");
759 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
766 * free_basic_memory_bitmaps - free memory bitmaps allocated by
767 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
768 * so that the bitmaps themselves are not referred to while they are being
772 void free_basic_memory_bitmaps(void)
774 struct memory_bitmap
*bm1
, *bm2
;
776 BUG_ON(!(forbidden_pages_map
&& free_pages_map
));
778 bm1
= forbidden_pages_map
;
779 bm2
= free_pages_map
;
780 forbidden_pages_map
= NULL
;
781 free_pages_map
= NULL
;
782 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
784 memory_bm_free(bm2
, PG_UNSAFE_CLEAR
);
787 printk("swsusp: Basic memory bitmaps freed\n");
791 * snapshot_additional_pages - estimate the number of additional pages
792 * be needed for setting up the suspend image data structures for given
793 * zone (usually the returned value is greater than the exact number)
796 unsigned int snapshot_additional_pages(struct zone
*zone
)
800 res
= DIV_ROUND_UP(zone
->spanned_pages
, BM_BITS_PER_BLOCK
);
801 res
+= DIV_ROUND_UP(res
* sizeof(struct bm_block
), PAGE_SIZE
);
805 #ifdef CONFIG_HIGHMEM
807 * count_free_highmem_pages - compute the total number of free highmem
808 * pages, system-wide.
811 static unsigned int count_free_highmem_pages(void)
814 unsigned int cnt
= 0;
817 if (populated_zone(zone
) && is_highmem(zone
))
818 cnt
+= zone_page_state(zone
, NR_FREE_PAGES
);
824 * saveable_highmem_page - Determine whether a highmem page should be
825 * included in the suspend image.
827 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
828 * and it isn't a part of a free chunk of pages.
831 static struct page
*saveable_highmem_page(unsigned long pfn
)
838 page
= pfn_to_page(pfn
);
840 BUG_ON(!PageHighMem(page
));
842 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
) ||
850 * count_highmem_pages - compute the total number of saveable highmem
854 unsigned int count_highmem_pages(void)
859 for_each_zone(zone
) {
860 unsigned long pfn
, max_zone_pfn
;
862 if (!is_highmem(zone
))
865 mark_free_pages(zone
);
866 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
867 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
868 if (saveable_highmem_page(pfn
))
874 static inline void *saveable_highmem_page(unsigned long pfn
) { return NULL
; }
875 #endif /* CONFIG_HIGHMEM */
878 * saveable - Determine whether a non-highmem page should be included in
881 * We should save the page if it isn't Nosave, and is not in the range
882 * of pages statically defined as 'unsaveable', and it isn't a part of
883 * a free chunk of pages.
886 static struct page
*saveable_page(unsigned long pfn
)
893 page
= pfn_to_page(pfn
);
895 BUG_ON(PageHighMem(page
));
897 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
))
900 if (PageReserved(page
) && pfn_is_nosave(pfn
))
907 * count_data_pages - compute the total number of saveable non-highmem
911 unsigned int count_data_pages(void)
914 unsigned long pfn
, max_zone_pfn
;
917 for_each_zone(zone
) {
918 if (is_highmem(zone
))
921 mark_free_pages(zone
);
922 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
923 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
924 if(saveable_page(pfn
))
930 /* This is needed, because copy_page and memcpy are not usable for copying
933 static inline void do_copy_page(long *dst
, long *src
)
937 for (n
= PAGE_SIZE
/ sizeof(long); n
; n
--)
941 #ifdef CONFIG_HIGHMEM
942 static inline struct page
*
943 page_is_saveable(struct zone
*zone
, unsigned long pfn
)
945 return is_highmem(zone
) ?
946 saveable_highmem_page(pfn
) : saveable_page(pfn
);
950 copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
952 struct page
*s_page
, *d_page
;
955 s_page
= pfn_to_page(src_pfn
);
956 d_page
= pfn_to_page(dst_pfn
);
957 if (PageHighMem(s_page
)) {
958 src
= kmap_atomic(s_page
, KM_USER0
);
959 dst
= kmap_atomic(d_page
, KM_USER1
);
960 do_copy_page(dst
, src
);
961 kunmap_atomic(src
, KM_USER0
);
962 kunmap_atomic(dst
, KM_USER1
);
964 src
= page_address(s_page
);
965 if (PageHighMem(d_page
)) {
966 /* Page pointed to by src may contain some kernel
967 * data modified by kmap_atomic()
969 do_copy_page(buffer
, src
);
970 dst
= kmap_atomic(pfn_to_page(dst_pfn
), KM_USER0
);
971 memcpy(dst
, buffer
, PAGE_SIZE
);
972 kunmap_atomic(dst
, KM_USER0
);
974 dst
= page_address(d_page
);
975 do_copy_page(dst
, src
);
980 #define page_is_saveable(zone, pfn) saveable_page(pfn)
983 copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
985 do_copy_page(page_address(pfn_to_page(dst_pfn
)),
986 page_address(pfn_to_page(src_pfn
)));
988 #endif /* CONFIG_HIGHMEM */
991 copy_data_pages(struct memory_bitmap
*copy_bm
, struct memory_bitmap
*orig_bm
)
996 for_each_zone(zone
) {
997 unsigned long max_zone_pfn
;
999 mark_free_pages(zone
);
1000 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1001 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1002 if (page_is_saveable(zone
, pfn
))
1003 memory_bm_set_bit(orig_bm
, pfn
);
1005 memory_bm_position_reset(orig_bm
);
1006 memory_bm_position_reset(copy_bm
);
1008 pfn
= memory_bm_next_pfn(orig_bm
);
1009 if (unlikely(pfn
== BM_END_OF_MAP
))
1011 copy_data_page(memory_bm_next_pfn(copy_bm
), pfn
);
1015 /* Total number of image pages */
1016 static unsigned int nr_copy_pages
;
1017 /* Number of pages needed for saving the original pfns of the image pages */
1018 static unsigned int nr_meta_pages
;
1021 * swsusp_free - free pages allocated for the suspend.
1023 * Suspend pages are alocated before the atomic copy is made, so we
1024 * need to release them after the resume.
1027 void swsusp_free(void)
1030 unsigned long pfn
, max_zone_pfn
;
1032 for_each_zone(zone
) {
1033 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1034 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1035 if (pfn_valid(pfn
)) {
1036 struct page
*page
= pfn_to_page(pfn
);
1038 if (swsusp_page_is_forbidden(page
) &&
1039 swsusp_page_is_free(page
)) {
1040 swsusp_unset_page_forbidden(page
);
1041 swsusp_unset_page_free(page
);
1048 restore_pblist
= NULL
;
1052 #ifdef CONFIG_HIGHMEM
1054 * count_pages_for_highmem - compute the number of non-highmem pages
1055 * that will be necessary for creating copies of highmem pages.
1058 static unsigned int count_pages_for_highmem(unsigned int nr_highmem
)
1060 unsigned int free_highmem
= count_free_highmem_pages();
1062 if (free_highmem
>= nr_highmem
)
1065 nr_highmem
-= free_highmem
;
1071 count_pages_for_highmem(unsigned int nr_highmem
) { return 0; }
1072 #endif /* CONFIG_HIGHMEM */
1075 * enough_free_mem - Make sure we have enough free memory for the
1079 static int enough_free_mem(unsigned int nr_pages
, unsigned int nr_highmem
)
1082 unsigned int free
= 0, meta
= 0;
1084 for_each_zone(zone
) {
1085 meta
+= snapshot_additional_pages(zone
);
1086 if (!is_highmem(zone
))
1087 free
+= zone_page_state(zone
, NR_FREE_PAGES
);
1090 nr_pages
+= count_pages_for_highmem(nr_highmem
);
1091 pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
1092 nr_pages
, PAGES_FOR_IO
, meta
, free
);
1094 return free
> nr_pages
+ PAGES_FOR_IO
+ meta
;
1097 #ifdef CONFIG_HIGHMEM
1099 * get_highmem_buffer - if there are some highmem pages in the suspend
1100 * image, we may need the buffer to copy them and/or load their data.
1103 static inline int get_highmem_buffer(int safe_needed
)
1105 buffer
= get_image_page(GFP_ATOMIC
| __GFP_COLD
, safe_needed
);
1106 return buffer
? 0 : -ENOMEM
;
1110 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1111 * Try to allocate as many pages as needed, but if the number of free
1112 * highmem pages is lesser than that, allocate them all.
1115 static inline unsigned int
1116 alloc_highmem_image_pages(struct memory_bitmap
*bm
, unsigned int nr_highmem
)
1118 unsigned int to_alloc
= count_free_highmem_pages();
1120 if (to_alloc
> nr_highmem
)
1121 to_alloc
= nr_highmem
;
1123 nr_highmem
-= to_alloc
;
1124 while (to_alloc
-- > 0) {
1127 page
= alloc_image_page(__GFP_HIGHMEM
);
1128 memory_bm_set_bit(bm
, page_to_pfn(page
));
1133 static inline int get_highmem_buffer(int safe_needed
) { return 0; }
1135 static inline unsigned int
1136 alloc_highmem_image_pages(struct memory_bitmap
*bm
, unsigned int n
) { return 0; }
1137 #endif /* CONFIG_HIGHMEM */
1140 * swsusp_alloc - allocate memory for the suspend image
1142 * We first try to allocate as many highmem pages as there are
1143 * saveable highmem pages in the system. If that fails, we allocate
1144 * non-highmem pages for the copies of the remaining highmem ones.
1146 * In this approach it is likely that the copies of highmem pages will
1147 * also be located in the high memory, because of the way in which
1148 * copy_data_pages() works.
1152 swsusp_alloc(struct memory_bitmap
*orig_bm
, struct memory_bitmap
*copy_bm
,
1153 unsigned int nr_pages
, unsigned int nr_highmem
)
1157 error
= memory_bm_create(orig_bm
, GFP_ATOMIC
| __GFP_COLD
, PG_ANY
);
1161 error
= memory_bm_create(copy_bm
, GFP_ATOMIC
| __GFP_COLD
, PG_ANY
);
1165 if (nr_highmem
> 0) {
1166 error
= get_highmem_buffer(PG_ANY
);
1170 nr_pages
+= alloc_highmem_image_pages(copy_bm
, nr_highmem
);
1172 while (nr_pages
-- > 0) {
1173 struct page
*page
= alloc_image_page(GFP_ATOMIC
| __GFP_COLD
);
1178 memory_bm_set_bit(copy_bm
, page_to_pfn(page
));
1187 /* Memory bitmap used for marking saveable pages (during suspend) or the
1188 * suspend image pages (during resume)
1190 static struct memory_bitmap orig_bm
;
1191 /* Memory bitmap used on suspend for marking allocated pages that will contain
1192 * the copies of saveable pages. During resume it is initially used for
1193 * marking the suspend image pages, but then its set bits are duplicated in
1194 * @orig_bm and it is released. Next, on systems with high memory, it may be
1195 * used for marking "safe" highmem pages, but it has to be reinitialized for
1198 static struct memory_bitmap copy_bm
;
1200 asmlinkage
int swsusp_save(void)
1202 unsigned int nr_pages
, nr_highmem
;
1204 printk("swsusp: critical section: \n");
1206 drain_local_pages();
1207 nr_pages
= count_data_pages();
1208 nr_highmem
= count_highmem_pages();
1209 printk("swsusp: Need to copy %u pages\n", nr_pages
+ nr_highmem
);
1211 if (!enough_free_mem(nr_pages
, nr_highmem
)) {
1212 printk(KERN_ERR
"swsusp: Not enough free memory\n");
1216 if (swsusp_alloc(&orig_bm
, ©_bm
, nr_pages
, nr_highmem
)) {
1217 printk(KERN_ERR
"swsusp: Memory allocation failed\n");
1221 /* During allocating of suspend pagedir, new cold pages may appear.
1224 drain_local_pages();
1225 copy_data_pages(©_bm
, &orig_bm
);
1228 * End of critical section. From now on, we can write to memory,
1229 * but we should not touch disk. This specially means we must _not_
1230 * touch swap space! Except we must write out our image of course.
1233 nr_pages
+= nr_highmem
;
1234 nr_copy_pages
= nr_pages
;
1235 nr_meta_pages
= DIV_ROUND_UP(nr_pages
* sizeof(long), PAGE_SIZE
);
1237 printk("swsusp: critical section: done (%d pages copied)\n", nr_pages
);
1242 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
1243 static int init_header_complete(struct swsusp_info
*info
)
1245 memcpy(&info
->uts
, init_utsname(), sizeof(struct new_utsname
));
1246 info
->version_code
= LINUX_VERSION_CODE
;
1250 static char *check_image_kernel(struct swsusp_info
*info
)
1252 if (info
->version_code
!= LINUX_VERSION_CODE
)
1253 return "kernel version";
1254 if (strcmp(info
->uts
.sysname
,init_utsname()->sysname
))
1255 return "system type";
1256 if (strcmp(info
->uts
.release
,init_utsname()->release
))
1257 return "kernel release";
1258 if (strcmp(info
->uts
.version
,init_utsname()->version
))
1260 if (strcmp(info
->uts
.machine
,init_utsname()->machine
))
1264 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1266 unsigned long snapshot_get_image_size(void)
1268 return nr_copy_pages
+ nr_meta_pages
+ 1;
1271 static int init_header(struct swsusp_info
*info
)
1273 memset(info
, 0, sizeof(struct swsusp_info
));
1274 info
->num_physpages
= num_physpages
;
1275 info
->image_pages
= nr_copy_pages
;
1276 info
->pages
= snapshot_get_image_size();
1277 info
->size
= info
->pages
;
1278 info
->size
<<= PAGE_SHIFT
;
1279 return init_header_complete(info
);
1283 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1284 * are stored in the array @buf[] (1 page at a time)
1288 pack_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
1292 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
1293 buf
[j
] = memory_bm_next_pfn(bm
);
1294 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
1300 * snapshot_read_next - used for reading the system memory snapshot.
1302 * On the first call to it @handle should point to a zeroed
1303 * snapshot_handle structure. The structure gets updated and a pointer
1304 * to it should be passed to this function every next time.
1306 * The @count parameter should contain the number of bytes the caller
1307 * wants to read from the snapshot. It must not be zero.
1309 * On success the function returns a positive number. Then, the caller
1310 * is allowed to read up to the returned number of bytes from the memory
1311 * location computed by the data_of() macro. The number returned
1312 * may be smaller than @count, but this only happens if the read would
1313 * cross a page boundary otherwise.
1315 * The function returns 0 to indicate the end of data stream condition,
1316 * and a negative number is returned on error. In such cases the
1317 * structure pointed to by @handle is not updated and should not be used
1321 int snapshot_read_next(struct snapshot_handle
*handle
, size_t count
)
1323 if (handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
1327 /* This makes the buffer be freed by swsusp_free() */
1328 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
1332 if (!handle
->offset
) {
1335 error
= init_header((struct swsusp_info
*)buffer
);
1338 handle
->buffer
= buffer
;
1339 memory_bm_position_reset(&orig_bm
);
1340 memory_bm_position_reset(©_bm
);
1342 if (handle
->prev
< handle
->cur
) {
1343 if (handle
->cur
<= nr_meta_pages
) {
1344 memset(buffer
, 0, PAGE_SIZE
);
1345 pack_pfns(buffer
, &orig_bm
);
1349 page
= pfn_to_page(memory_bm_next_pfn(©_bm
));
1350 if (PageHighMem(page
)) {
1351 /* Highmem pages are copied to the buffer,
1352 * because we can't return with a kmapped
1353 * highmem page (we may not be called again).
1357 kaddr
= kmap_atomic(page
, KM_USER0
);
1358 memcpy(buffer
, kaddr
, PAGE_SIZE
);
1359 kunmap_atomic(kaddr
, KM_USER0
);
1360 handle
->buffer
= buffer
;
1362 handle
->buffer
= page_address(page
);
1365 handle
->prev
= handle
->cur
;
1367 handle
->buf_offset
= handle
->cur_offset
;
1368 if (handle
->cur_offset
+ count
>= PAGE_SIZE
) {
1369 count
= PAGE_SIZE
- handle
->cur_offset
;
1370 handle
->cur_offset
= 0;
1373 handle
->cur_offset
+= count
;
1375 handle
->offset
+= count
;
1380 * mark_unsafe_pages - mark the pages that cannot be used for storing
1381 * the image during resume, because they conflict with the pages that
1382 * had been used before suspend
1385 static int mark_unsafe_pages(struct memory_bitmap
*bm
)
1388 unsigned long pfn
, max_zone_pfn
;
1390 /* Clear page flags */
1391 for_each_zone(zone
) {
1392 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1393 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1395 swsusp_unset_page_free(pfn_to_page(pfn
));
1398 /* Mark pages that correspond to the "original" pfns as "unsafe" */
1399 memory_bm_position_reset(bm
);
1401 pfn
= memory_bm_next_pfn(bm
);
1402 if (likely(pfn
!= BM_END_OF_MAP
)) {
1403 if (likely(pfn_valid(pfn
)))
1404 swsusp_set_page_free(pfn_to_page(pfn
));
1408 } while (pfn
!= BM_END_OF_MAP
);
1410 allocated_unsafe_pages
= 0;
1416 duplicate_memory_bitmap(struct memory_bitmap
*dst
, struct memory_bitmap
*src
)
1420 memory_bm_position_reset(src
);
1421 pfn
= memory_bm_next_pfn(src
);
1422 while (pfn
!= BM_END_OF_MAP
) {
1423 memory_bm_set_bit(dst
, pfn
);
1424 pfn
= memory_bm_next_pfn(src
);
1428 static int check_header(struct swsusp_info
*info
)
1432 reason
= check_image_kernel(info
);
1433 if (!reason
&& info
->num_physpages
!= num_physpages
)
1434 reason
= "memory size";
1436 printk(KERN_ERR
"swsusp: Resume mismatch: %s\n", reason
);
1443 * load header - check the image header and copy data from it
1447 load_header(struct swsusp_info
*info
)
1451 restore_pblist
= NULL
;
1452 error
= check_header(info
);
1454 nr_copy_pages
= info
->image_pages
;
1455 nr_meta_pages
= info
->pages
- info
->image_pages
- 1;
1461 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1462 * the corresponding bit in the memory bitmap @bm
1466 unpack_orig_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
1470 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
1471 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
1474 memory_bm_set_bit(bm
, buf
[j
]);
1478 /* List of "safe" pages that may be used to store data loaded from the suspend
1481 static struct linked_page
*safe_pages_list
;
1483 #ifdef CONFIG_HIGHMEM
1484 /* struct highmem_pbe is used for creating the list of highmem pages that
1485 * should be restored atomically during the resume from disk, because the page
1486 * frames they have occupied before the suspend are in use.
1488 struct highmem_pbe
{
1489 struct page
*copy_page
; /* data is here now */
1490 struct page
*orig_page
; /* data was here before the suspend */
1491 struct highmem_pbe
*next
;
1494 /* List of highmem PBEs needed for restoring the highmem pages that were
1495 * allocated before the suspend and included in the suspend image, but have
1496 * also been allocated by the "resume" kernel, so their contents cannot be
1497 * written directly to their "original" page frames.
1499 static struct highmem_pbe
*highmem_pblist
;
1502 * count_highmem_image_pages - compute the number of highmem pages in the
1503 * suspend image. The bits in the memory bitmap @bm that correspond to the
1504 * image pages are assumed to be set.
1507 static unsigned int count_highmem_image_pages(struct memory_bitmap
*bm
)
1510 unsigned int cnt
= 0;
1512 memory_bm_position_reset(bm
);
1513 pfn
= memory_bm_next_pfn(bm
);
1514 while (pfn
!= BM_END_OF_MAP
) {
1515 if (PageHighMem(pfn_to_page(pfn
)))
1518 pfn
= memory_bm_next_pfn(bm
);
1524 * prepare_highmem_image - try to allocate as many highmem pages as
1525 * there are highmem image pages (@nr_highmem_p points to the variable
1526 * containing the number of highmem image pages). The pages that are
1527 * "safe" (ie. will not be overwritten when the suspend image is
1528 * restored) have the corresponding bits set in @bm (it must be
1531 * NOTE: This function should not be called if there are no highmem
1535 static unsigned int safe_highmem_pages
;
1537 static struct memory_bitmap
*safe_highmem_bm
;
1540 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
1542 unsigned int to_alloc
;
1544 if (memory_bm_create(bm
, GFP_ATOMIC
, PG_SAFE
))
1547 if (get_highmem_buffer(PG_SAFE
))
1550 to_alloc
= count_free_highmem_pages();
1551 if (to_alloc
> *nr_highmem_p
)
1552 to_alloc
= *nr_highmem_p
;
1554 *nr_highmem_p
= to_alloc
;
1556 safe_highmem_pages
= 0;
1557 while (to_alloc
-- > 0) {
1560 page
= alloc_page(__GFP_HIGHMEM
);
1561 if (!swsusp_page_is_free(page
)) {
1562 /* The page is "safe", set its bit the bitmap */
1563 memory_bm_set_bit(bm
, page_to_pfn(page
));
1564 safe_highmem_pages
++;
1566 /* Mark the page as allocated */
1567 swsusp_set_page_forbidden(page
);
1568 swsusp_set_page_free(page
);
1570 memory_bm_position_reset(bm
);
1571 safe_highmem_bm
= bm
;
1576 * get_highmem_page_buffer - for given highmem image page find the buffer
1577 * that suspend_write_next() should set for its caller to write to.
1579 * If the page is to be saved to its "original" page frame or a copy of
1580 * the page is to be made in the highmem, @buffer is returned. Otherwise,
1581 * the copy of the page is to be made in normal memory, so the address of
1582 * the copy is returned.
1584 * If @buffer is returned, the caller of suspend_write_next() will write
1585 * the page's contents to @buffer, so they will have to be copied to the
1586 * right location on the next call to suspend_write_next() and it is done
1587 * with the help of copy_last_highmem_page(). For this purpose, if
1588 * @buffer is returned, @last_highmem page is set to the page to which
1589 * the data will have to be copied from @buffer.
1592 static struct page
*last_highmem_page
;
1595 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
1597 struct highmem_pbe
*pbe
;
1600 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
)) {
1601 /* We have allocated the "original" page frame and we can
1602 * use it directly to store the loaded page.
1604 last_highmem_page
= page
;
1607 /* The "original" page frame has not been allocated and we have to
1608 * use a "safe" page frame to store the loaded page.
1610 pbe
= chain_alloc(ca
, sizeof(struct highmem_pbe
));
1615 pbe
->orig_page
= page
;
1616 if (safe_highmem_pages
> 0) {
1619 /* Copy of the page will be stored in high memory */
1621 tmp
= pfn_to_page(memory_bm_next_pfn(safe_highmem_bm
));
1622 safe_highmem_pages
--;
1623 last_highmem_page
= tmp
;
1624 pbe
->copy_page
= tmp
;
1626 /* Copy of the page will be stored in normal memory */
1627 kaddr
= safe_pages_list
;
1628 safe_pages_list
= safe_pages_list
->next
;
1629 pbe
->copy_page
= virt_to_page(kaddr
);
1631 pbe
->next
= highmem_pblist
;
1632 highmem_pblist
= pbe
;
1637 * copy_last_highmem_page - copy the contents of a highmem image from
1638 * @buffer, where the caller of snapshot_write_next() has place them,
1639 * to the right location represented by @last_highmem_page .
1642 static void copy_last_highmem_page(void)
1644 if (last_highmem_page
) {
1647 dst
= kmap_atomic(last_highmem_page
, KM_USER0
);
1648 memcpy(dst
, buffer
, PAGE_SIZE
);
1649 kunmap_atomic(dst
, KM_USER0
);
1650 last_highmem_page
= NULL
;
1654 static inline int last_highmem_page_copied(void)
1656 return !last_highmem_page
;
1659 static inline void free_highmem_data(void)
1661 if (safe_highmem_bm
)
1662 memory_bm_free(safe_highmem_bm
, PG_UNSAFE_CLEAR
);
1665 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
1668 static inline int get_safe_write_buffer(void) { return 0; }
1671 count_highmem_image_pages(struct memory_bitmap
*bm
) { return 0; }
1674 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
1679 static inline void *
1680 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
1685 static inline void copy_last_highmem_page(void) {}
1686 static inline int last_highmem_page_copied(void) { return 1; }
1687 static inline void free_highmem_data(void) {}
1688 #endif /* CONFIG_HIGHMEM */
1691 * prepare_image - use the memory bitmap @bm to mark the pages that will
1692 * be overwritten in the process of restoring the system memory state
1693 * from the suspend image ("unsafe" pages) and allocate memory for the
1696 * The idea is to allocate a new memory bitmap first and then allocate
1697 * as many pages as needed for the image data, but not to assign these
1698 * pages to specific tasks initially. Instead, we just mark them as
1699 * allocated and create a lists of "safe" pages that will be used
1700 * later. On systems with high memory a list of "safe" highmem pages is
1704 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
1707 prepare_image(struct memory_bitmap
*new_bm
, struct memory_bitmap
*bm
)
1709 unsigned int nr_pages
, nr_highmem
;
1710 struct linked_page
*sp_list
, *lp
;
1713 /* If there is no highmem, the buffer will not be necessary */
1714 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
1717 nr_highmem
= count_highmem_image_pages(bm
);
1718 error
= mark_unsafe_pages(bm
);
1722 error
= memory_bm_create(new_bm
, GFP_ATOMIC
, PG_SAFE
);
1726 duplicate_memory_bitmap(new_bm
, bm
);
1727 memory_bm_free(bm
, PG_UNSAFE_KEEP
);
1728 if (nr_highmem
> 0) {
1729 error
= prepare_highmem_image(bm
, &nr_highmem
);
1733 /* Reserve some safe pages for potential later use.
1735 * NOTE: This way we make sure there will be enough safe pages for the
1736 * chain_alloc() in get_buffer(). It is a bit wasteful, but
1737 * nr_copy_pages cannot be greater than 50% of the memory anyway.
1740 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
1741 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
1742 nr_pages
= DIV_ROUND_UP(nr_pages
, PBES_PER_LINKED_PAGE
);
1743 while (nr_pages
> 0) {
1744 lp
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
1753 /* Preallocate memory for the image */
1754 safe_pages_list
= NULL
;
1755 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
1756 while (nr_pages
> 0) {
1757 lp
= (struct linked_page
*)get_zeroed_page(GFP_ATOMIC
);
1762 if (!swsusp_page_is_free(virt_to_page(lp
))) {
1763 /* The page is "safe", add it to the list */
1764 lp
->next
= safe_pages_list
;
1765 safe_pages_list
= lp
;
1767 /* Mark the page as allocated */
1768 swsusp_set_page_forbidden(virt_to_page(lp
));
1769 swsusp_set_page_free(virt_to_page(lp
));
1772 /* Free the reserved safe pages so that chain_alloc() can use them */
1775 free_image_page(sp_list
, PG_UNSAFE_CLEAR
);
1786 * get_buffer - compute the address that snapshot_write_next() should
1787 * set for its caller to write to.
1790 static void *get_buffer(struct memory_bitmap
*bm
, struct chain_allocator
*ca
)
1793 struct page
*page
= pfn_to_page(memory_bm_next_pfn(bm
));
1795 if (PageHighMem(page
))
1796 return get_highmem_page_buffer(page
, ca
);
1798 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
))
1799 /* We have allocated the "original" page frame and we can
1800 * use it directly to store the loaded page.
1802 return page_address(page
);
1804 /* The "original" page frame has not been allocated and we have to
1805 * use a "safe" page frame to store the loaded page.
1807 pbe
= chain_alloc(ca
, sizeof(struct pbe
));
1812 pbe
->orig_address
= page_address(page
);
1813 pbe
->address
= safe_pages_list
;
1814 safe_pages_list
= safe_pages_list
->next
;
1815 pbe
->next
= restore_pblist
;
1816 restore_pblist
= pbe
;
1817 return pbe
->address
;
1821 * snapshot_write_next - used for writing the system memory snapshot.
1823 * On the first call to it @handle should point to a zeroed
1824 * snapshot_handle structure. The structure gets updated and a pointer
1825 * to it should be passed to this function every next time.
1827 * The @count parameter should contain the number of bytes the caller
1828 * wants to write to the image. It must not be zero.
1830 * On success the function returns a positive number. Then, the caller
1831 * is allowed to write up to the returned number of bytes to the memory
1832 * location computed by the data_of() macro. The number returned
1833 * may be smaller than @count, but this only happens if the write would
1834 * cross a page boundary otherwise.
1836 * The function returns 0 to indicate the "end of file" condition,
1837 * and a negative number is returned on error. In such cases the
1838 * structure pointed to by @handle is not updated and should not be used
1842 int snapshot_write_next(struct snapshot_handle
*handle
, size_t count
)
1844 static struct chain_allocator ca
;
1847 /* Check if we have already loaded the entire image */
1848 if (handle
->prev
&& handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
1851 if (handle
->offset
== 0) {
1853 /* This makes the buffer be freed by swsusp_free() */
1854 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
1859 handle
->buffer
= buffer
;
1861 handle
->sync_read
= 1;
1862 if (handle
->prev
< handle
->cur
) {
1863 if (handle
->prev
== 0) {
1864 error
= load_header(buffer
);
1868 error
= memory_bm_create(©_bm
, GFP_ATOMIC
, PG_ANY
);
1872 } else if (handle
->prev
<= nr_meta_pages
) {
1873 unpack_orig_pfns(buffer
, ©_bm
);
1874 if (handle
->prev
== nr_meta_pages
) {
1875 error
= prepare_image(&orig_bm
, ©_bm
);
1879 chain_init(&ca
, GFP_ATOMIC
, PG_SAFE
);
1880 memory_bm_position_reset(&orig_bm
);
1881 restore_pblist
= NULL
;
1882 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
1883 handle
->sync_read
= 0;
1884 if (!handle
->buffer
)
1888 copy_last_highmem_page();
1889 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
1890 if (handle
->buffer
!= buffer
)
1891 handle
->sync_read
= 0;
1893 handle
->prev
= handle
->cur
;
1895 handle
->buf_offset
= handle
->cur_offset
;
1896 if (handle
->cur_offset
+ count
>= PAGE_SIZE
) {
1897 count
= PAGE_SIZE
- handle
->cur_offset
;
1898 handle
->cur_offset
= 0;
1901 handle
->cur_offset
+= count
;
1903 handle
->offset
+= count
;
1908 * snapshot_write_finalize - must be called after the last call to
1909 * snapshot_write_next() in case the last page in the image happens
1910 * to be a highmem page and its contents should be stored in the
1911 * highmem. Additionally, it releases the memory that will not be
1915 void snapshot_write_finalize(struct snapshot_handle
*handle
)
1917 copy_last_highmem_page();
1918 /* Free only if we have loaded the image entirely */
1919 if (handle
->prev
&& handle
->cur
> nr_meta_pages
+ nr_copy_pages
) {
1920 memory_bm_free(&orig_bm
, PG_UNSAFE_CLEAR
);
1921 free_highmem_data();
1925 int snapshot_image_loaded(struct snapshot_handle
*handle
)
1927 return !(!nr_copy_pages
|| !last_highmem_page_copied() ||
1928 handle
->cur
<= nr_meta_pages
+ nr_copy_pages
);
1931 #ifdef CONFIG_HIGHMEM
1932 /* Assumes that @buf is ready and points to a "safe" page */
1934 swap_two_pages_data(struct page
*p1
, struct page
*p2
, void *buf
)
1936 void *kaddr1
, *kaddr2
;
1938 kaddr1
= kmap_atomic(p1
, KM_USER0
);
1939 kaddr2
= kmap_atomic(p2
, KM_USER1
);
1940 memcpy(buf
, kaddr1
, PAGE_SIZE
);
1941 memcpy(kaddr1
, kaddr2
, PAGE_SIZE
);
1942 memcpy(kaddr2
, buf
, PAGE_SIZE
);
1943 kunmap_atomic(kaddr1
, KM_USER0
);
1944 kunmap_atomic(kaddr2
, KM_USER1
);
1948 * restore_highmem - for each highmem page that was allocated before
1949 * the suspend and included in the suspend image, and also has been
1950 * allocated by the "resume" kernel swap its current (ie. "before
1951 * resume") contents with the previous (ie. "before suspend") one.
1953 * If the resume eventually fails, we can call this function once
1954 * again and restore the "before resume" highmem state.
1957 int restore_highmem(void)
1959 struct highmem_pbe
*pbe
= highmem_pblist
;
1965 buf
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
1970 swap_two_pages_data(pbe
->copy_page
, pbe
->orig_page
, buf
);
1973 free_image_page(buf
, PG_UNSAFE_CLEAR
);
1976 #endif /* CONFIG_HIGHMEM */