2 * linux/kernel/power/snapshot.c
4 * This file provides system snapshot/restore functionality for swsusp.
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.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>
28 #include <linux/list.h>
29 #include <linux/slab.h>
30 #include <linux/compiler.h>
31 #include <linux/ktime.h>
33 #include <asm/uaccess.h>
34 #include <asm/mmu_context.h>
35 #include <asm/pgtable.h>
36 #include <asm/tlbflush.h>
41 static int swsusp_page_is_free(struct page
*);
42 static void swsusp_set_page_forbidden(struct page
*);
43 static void swsusp_unset_page_forbidden(struct page
*);
46 * Number of bytes to reserve for memory allocations made by device drivers
47 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
48 * cause image creation to fail (tunable via /sys/power/reserved_size).
50 unsigned long reserved_size
;
52 void __init
hibernate_reserved_size_init(void)
54 reserved_size
= SPARE_PAGES
* PAGE_SIZE
;
58 * Preferred image size in bytes (tunable via /sys/power/image_size).
59 * When it is set to N, swsusp will do its best to ensure the image
60 * size will not exceed N bytes, but if that is impossible, it will
61 * try to create the smallest image possible.
63 unsigned long image_size
;
65 void __init
hibernate_image_size_init(void)
67 image_size
= ((totalram_pages
* 2) / 5) * PAGE_SIZE
;
70 /* List of PBEs needed for restoring the pages that were allocated before
71 * the suspend and included in the suspend image, but have also been
72 * allocated by the "resume" kernel, so their contents cannot be written
73 * directly to their "original" page frames.
75 struct pbe
*restore_pblist
;
77 /* Pointer to an auxiliary buffer (1 page) */
81 * @safe_needed - on resume, for storing the PBE list and the image,
82 * we can only use memory pages that do not conflict with the pages
83 * used before suspend. The unsafe pages have PageNosaveFree set
84 * and we count them using unsafe_pages.
86 * Each allocated image page is marked as PageNosave and PageNosaveFree
87 * so that swsusp_free() can release it.
92 #define PG_UNSAFE_CLEAR 1
93 #define PG_UNSAFE_KEEP 0
95 static unsigned int allocated_unsafe_pages
;
97 static void *get_image_page(gfp_t gfp_mask
, int safe_needed
)
101 res
= (void *)get_zeroed_page(gfp_mask
);
103 while (res
&& swsusp_page_is_free(virt_to_page(res
))) {
104 /* The page is unsafe, mark it for swsusp_free() */
105 swsusp_set_page_forbidden(virt_to_page(res
));
106 allocated_unsafe_pages
++;
107 res
= (void *)get_zeroed_page(gfp_mask
);
110 swsusp_set_page_forbidden(virt_to_page(res
));
111 swsusp_set_page_free(virt_to_page(res
));
116 unsigned long get_safe_page(gfp_t gfp_mask
)
118 return (unsigned long)get_image_page(gfp_mask
, PG_SAFE
);
121 static struct page
*alloc_image_page(gfp_t gfp_mask
)
125 page
= alloc_page(gfp_mask
);
127 swsusp_set_page_forbidden(page
);
128 swsusp_set_page_free(page
);
134 * free_image_page - free page represented by @addr, allocated with
135 * get_image_page (page flags set by it must be cleared)
138 static inline void free_image_page(void *addr
, int clear_nosave_free
)
142 BUG_ON(!virt_addr_valid(addr
));
144 page
= virt_to_page(addr
);
146 swsusp_unset_page_forbidden(page
);
147 if (clear_nosave_free
)
148 swsusp_unset_page_free(page
);
153 /* struct linked_page is used to build chains of pages */
155 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
158 struct linked_page
*next
;
159 char data
[LINKED_PAGE_DATA_SIZE
];
163 free_list_of_pages(struct linked_page
*list
, int clear_page_nosave
)
166 struct linked_page
*lp
= list
->next
;
168 free_image_page(list
, clear_page_nosave
);
174 * struct chain_allocator is used for allocating small objects out of
175 * a linked list of pages called 'the chain'.
177 * The chain grows each time when there is no room for a new object in
178 * the current page. The allocated objects cannot be freed individually.
179 * It is only possible to free them all at once, by freeing the entire
182 * NOTE: The chain allocator may be inefficient if the allocated objects
183 * are not much smaller than PAGE_SIZE.
186 struct chain_allocator
{
187 struct linked_page
*chain
; /* the chain */
188 unsigned int used_space
; /* total size of objects allocated out
189 * of the current page
191 gfp_t gfp_mask
; /* mask for allocating pages */
192 int safe_needed
; /* if set, only "safe" pages are allocated */
196 chain_init(struct chain_allocator
*ca
, gfp_t gfp_mask
, int safe_needed
)
199 ca
->used_space
= LINKED_PAGE_DATA_SIZE
;
200 ca
->gfp_mask
= gfp_mask
;
201 ca
->safe_needed
= safe_needed
;
204 static void *chain_alloc(struct chain_allocator
*ca
, unsigned int size
)
208 if (LINKED_PAGE_DATA_SIZE
- ca
->used_space
< size
) {
209 struct linked_page
*lp
;
211 lp
= get_image_page(ca
->gfp_mask
, ca
->safe_needed
);
215 lp
->next
= ca
->chain
;
219 ret
= ca
->chain
->data
+ ca
->used_space
;
220 ca
->used_space
+= size
;
225 * Data types related to memory bitmaps.
227 * Memory bitmap is a structure consiting of many linked lists of
228 * objects. The main list's elements are of type struct zone_bitmap
229 * and each of them corresonds to one zone. For each zone bitmap
230 * object there is a list of objects of type struct bm_block that
231 * represent each blocks of bitmap in which information is stored.
233 * struct memory_bitmap contains a pointer to the main list of zone
234 * bitmap objects, a struct bm_position used for browsing the bitmap,
235 * and a pointer to the list of pages used for allocating all of the
236 * zone bitmap objects and bitmap block objects.
238 * NOTE: It has to be possible to lay out the bitmap in memory
239 * using only allocations of order 0. Additionally, the bitmap is
240 * designed to work with arbitrary number of zones (this is over the
241 * top for now, but let's avoid making unnecessary assumptions ;-).
243 * struct zone_bitmap contains a pointer to a list of bitmap block
244 * objects and a pointer to the bitmap block object that has been
245 * most recently used for setting bits. Additionally, it contains the
246 * pfns that correspond to the start and end of the represented zone.
248 * struct bm_block contains a pointer to the memory page in which
249 * information is stored (in the form of a block of bitmap)
250 * It also contains the pfns that correspond to the start and end of
251 * the represented memory area.
253 * The memory bitmap is organized as a radix tree to guarantee fast random
254 * access to the bits. There is one radix tree for each zone (as returned
255 * from create_mem_extents).
257 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
258 * two linked lists for the nodes of the tree, one for the inner nodes and
259 * one for the leave nodes. The linked leave nodes are used for fast linear
260 * access of the memory bitmap.
262 * The struct rtree_node represents one node of the radix tree.
265 #define BM_END_OF_MAP (~0UL)
267 #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
268 #define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
269 #define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
272 * struct rtree_node is a wrapper struct to link the nodes
273 * of the rtree together for easy linear iteration over
274 * bits and easy freeing
277 struct list_head list
;
282 * struct mem_zone_bm_rtree represents a bitmap used for one
283 * populated memory zone.
285 struct mem_zone_bm_rtree
{
286 struct list_head list
; /* Link Zones together */
287 struct list_head nodes
; /* Radix Tree inner nodes */
288 struct list_head leaves
; /* Radix Tree leaves */
289 unsigned long start_pfn
; /* Zone start page frame */
290 unsigned long end_pfn
; /* Zone end page frame + 1 */
291 struct rtree_node
*rtree
; /* Radix Tree Root */
292 int levels
; /* Number of Radix Tree Levels */
293 unsigned int blocks
; /* Number of Bitmap Blocks */
296 /* strcut bm_position is used for browsing memory bitmaps */
299 struct mem_zone_bm_rtree
*zone
;
300 struct rtree_node
*node
;
301 unsigned long node_pfn
;
305 struct memory_bitmap
{
306 struct list_head zones
;
307 struct linked_page
*p_list
; /* list of pages used to store zone
308 * bitmap objects and bitmap block
311 struct bm_position cur
; /* most recently used bit position */
314 /* Functions that operate on memory bitmaps */
316 #define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
317 #if BITS_PER_LONG == 32
318 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
320 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
322 #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
325 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
327 * This function is used to allocate inner nodes as well as the
328 * leave nodes of the radix tree. It also adds the node to the
329 * corresponding linked list passed in by the *list parameter.
331 static struct rtree_node
*alloc_rtree_node(gfp_t gfp_mask
, int safe_needed
,
332 struct chain_allocator
*ca
,
333 struct list_head
*list
)
335 struct rtree_node
*node
;
337 node
= chain_alloc(ca
, sizeof(struct rtree_node
));
341 node
->data
= get_image_page(gfp_mask
, safe_needed
);
345 list_add_tail(&node
->list
, list
);
351 * add_rtree_block - Add a new leave node to the radix tree
353 * The leave nodes need to be allocated in order to keep the leaves
354 * linked list in order. This is guaranteed by the zone->blocks
357 static int add_rtree_block(struct mem_zone_bm_rtree
*zone
, gfp_t gfp_mask
,
358 int safe_needed
, struct chain_allocator
*ca
)
360 struct rtree_node
*node
, *block
, **dst
;
361 unsigned int levels_needed
, block_nr
;
364 block_nr
= zone
->blocks
;
367 /* How many levels do we need for this block nr? */
370 block_nr
>>= BM_RTREE_LEVEL_SHIFT
;
373 /* Make sure the rtree has enough levels */
374 for (i
= zone
->levels
; i
< levels_needed
; i
++) {
375 node
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
,
380 node
->data
[0] = (unsigned long)zone
->rtree
;
385 /* Allocate new block */
386 block
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
, &zone
->leaves
);
390 /* Now walk the rtree to insert the block */
393 block_nr
= zone
->blocks
;
394 for (i
= zone
->levels
; i
> 0; i
--) {
398 node
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
,
405 index
= block_nr
>> ((i
- 1) * BM_RTREE_LEVEL_SHIFT
);
406 index
&= BM_RTREE_LEVEL_MASK
;
407 dst
= (struct rtree_node
**)&((*dst
)->data
[index
]);
417 static void free_zone_bm_rtree(struct mem_zone_bm_rtree
*zone
,
418 int clear_nosave_free
);
421 * create_zone_bm_rtree - create a radix tree for one zone
423 * Allocated the mem_zone_bm_rtree structure and initializes it.
424 * This function also allocated and builds the radix tree for the
427 static struct mem_zone_bm_rtree
*
428 create_zone_bm_rtree(gfp_t gfp_mask
, int safe_needed
,
429 struct chain_allocator
*ca
,
430 unsigned long start
, unsigned long end
)
432 struct mem_zone_bm_rtree
*zone
;
433 unsigned int i
, nr_blocks
;
437 zone
= chain_alloc(ca
, sizeof(struct mem_zone_bm_rtree
));
441 INIT_LIST_HEAD(&zone
->nodes
);
442 INIT_LIST_HEAD(&zone
->leaves
);
443 zone
->start_pfn
= start
;
445 nr_blocks
= DIV_ROUND_UP(pages
, BM_BITS_PER_BLOCK
);
447 for (i
= 0; i
< nr_blocks
; i
++) {
448 if (add_rtree_block(zone
, gfp_mask
, safe_needed
, ca
)) {
449 free_zone_bm_rtree(zone
, PG_UNSAFE_CLEAR
);
458 * free_zone_bm_rtree - Free the memory of the radix tree
460 * Free all node pages of the radix tree. The mem_zone_bm_rtree
461 * structure itself is not freed here nor are the rtree_node
464 static void free_zone_bm_rtree(struct mem_zone_bm_rtree
*zone
,
465 int clear_nosave_free
)
467 struct rtree_node
*node
;
469 list_for_each_entry(node
, &zone
->nodes
, list
)
470 free_image_page(node
->data
, clear_nosave_free
);
472 list_for_each_entry(node
, &zone
->leaves
, list
)
473 free_image_page(node
->data
, clear_nosave_free
);
476 static void memory_bm_position_reset(struct memory_bitmap
*bm
)
478 bm
->cur
.zone
= list_entry(bm
->zones
.next
, struct mem_zone_bm_rtree
,
480 bm
->cur
.node
= list_entry(bm
->cur
.zone
->leaves
.next
,
481 struct rtree_node
, list
);
482 bm
->cur
.node_pfn
= 0;
483 bm
->cur
.node_bit
= 0;
486 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
);
489 struct list_head hook
;
495 * free_mem_extents - free a list of memory extents
496 * @list - list of extents to empty
498 static void free_mem_extents(struct list_head
*list
)
500 struct mem_extent
*ext
, *aux
;
502 list_for_each_entry_safe(ext
, aux
, list
, hook
) {
503 list_del(&ext
->hook
);
509 * create_mem_extents - create a list of memory extents representing
510 * contiguous ranges of PFNs
511 * @list - list to put the extents into
512 * @gfp_mask - mask to use for memory allocations
514 static int create_mem_extents(struct list_head
*list
, gfp_t gfp_mask
)
518 INIT_LIST_HEAD(list
);
520 for_each_populated_zone(zone
) {
521 unsigned long zone_start
, zone_end
;
522 struct mem_extent
*ext
, *cur
, *aux
;
524 zone_start
= zone
->zone_start_pfn
;
525 zone_end
= zone_end_pfn(zone
);
527 list_for_each_entry(ext
, list
, hook
)
528 if (zone_start
<= ext
->end
)
531 if (&ext
->hook
== list
|| zone_end
< ext
->start
) {
532 /* New extent is necessary */
533 struct mem_extent
*new_ext
;
535 new_ext
= kzalloc(sizeof(struct mem_extent
), gfp_mask
);
537 free_mem_extents(list
);
540 new_ext
->start
= zone_start
;
541 new_ext
->end
= zone_end
;
542 list_add_tail(&new_ext
->hook
, &ext
->hook
);
546 /* Merge this zone's range of PFNs with the existing one */
547 if (zone_start
< ext
->start
)
548 ext
->start
= zone_start
;
549 if (zone_end
> ext
->end
)
552 /* More merging may be possible */
554 list_for_each_entry_safe_continue(cur
, aux
, list
, hook
) {
555 if (zone_end
< cur
->start
)
557 if (zone_end
< cur
->end
)
559 list_del(&cur
->hook
);
568 * memory_bm_create - allocate memory for a memory bitmap
571 memory_bm_create(struct memory_bitmap
*bm
, gfp_t gfp_mask
, int safe_needed
)
573 struct chain_allocator ca
;
574 struct list_head mem_extents
;
575 struct mem_extent
*ext
;
578 chain_init(&ca
, gfp_mask
, safe_needed
);
579 INIT_LIST_HEAD(&bm
->zones
);
581 error
= create_mem_extents(&mem_extents
, gfp_mask
);
585 list_for_each_entry(ext
, &mem_extents
, hook
) {
586 struct mem_zone_bm_rtree
*zone
;
588 zone
= create_zone_bm_rtree(gfp_mask
, safe_needed
, &ca
,
589 ext
->start
, ext
->end
);
594 list_add_tail(&zone
->list
, &bm
->zones
);
597 bm
->p_list
= ca
.chain
;
598 memory_bm_position_reset(bm
);
600 free_mem_extents(&mem_extents
);
604 bm
->p_list
= ca
.chain
;
605 memory_bm_free(bm
, PG_UNSAFE_CLEAR
);
610 * memory_bm_free - free memory occupied by the memory bitmap @bm
612 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
)
614 struct mem_zone_bm_rtree
*zone
;
616 list_for_each_entry(zone
, &bm
->zones
, list
)
617 free_zone_bm_rtree(zone
, clear_nosave_free
);
619 free_list_of_pages(bm
->p_list
, clear_nosave_free
);
621 INIT_LIST_HEAD(&bm
->zones
);
625 * memory_bm_find_bit - Find the bit for pfn in the memory
628 * Find the bit in the bitmap @bm that corresponds to given pfn.
629 * The cur.zone, cur.block and cur.node_pfn member of @bm are
631 * It walks the radix tree to find the page which contains the bit for
632 * pfn and returns the bit position in **addr and *bit_nr.
634 static int memory_bm_find_bit(struct memory_bitmap
*bm
, unsigned long pfn
,
635 void **addr
, unsigned int *bit_nr
)
637 struct mem_zone_bm_rtree
*curr
, *zone
;
638 struct rtree_node
*node
;
643 if (pfn
>= zone
->start_pfn
&& pfn
< zone
->end_pfn
)
648 /* Find the right zone */
649 list_for_each_entry(curr
, &bm
->zones
, list
) {
650 if (pfn
>= curr
->start_pfn
&& pfn
< curr
->end_pfn
) {
661 * We have a zone. Now walk the radix tree to find the leave
666 if (((pfn
- zone
->start_pfn
) & ~BM_BLOCK_MASK
) == bm
->cur
.node_pfn
)
670 block_nr
= (pfn
- zone
->start_pfn
) >> BM_BLOCK_SHIFT
;
672 for (i
= zone
->levels
; i
> 0; i
--) {
675 index
= block_nr
>> ((i
- 1) * BM_RTREE_LEVEL_SHIFT
);
676 index
&= BM_RTREE_LEVEL_MASK
;
677 BUG_ON(node
->data
[index
] == 0);
678 node
= (struct rtree_node
*)node
->data
[index
];
682 /* Update last position */
685 bm
->cur
.node_pfn
= (pfn
- zone
->start_pfn
) & ~BM_BLOCK_MASK
;
687 /* Set return values */
689 *bit_nr
= (pfn
- zone
->start_pfn
) & BM_BLOCK_MASK
;
694 static void memory_bm_set_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
700 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
705 static int mem_bm_set_bit_check(struct memory_bitmap
*bm
, unsigned long pfn
)
711 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
718 static void memory_bm_clear_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
724 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
726 clear_bit(bit
, addr
);
729 static void memory_bm_clear_current(struct memory_bitmap
*bm
)
733 bit
= max(bm
->cur
.node_bit
- 1, 0);
734 clear_bit(bit
, bm
->cur
.node
->data
);
737 static int memory_bm_test_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
743 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
745 return test_bit(bit
, addr
);
748 static bool memory_bm_pfn_present(struct memory_bitmap
*bm
, unsigned long pfn
)
753 return !memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
757 * rtree_next_node - Jumps to the next leave node
759 * Sets the position to the beginning of the next node in the
760 * memory bitmap. This is either the next node in the current
761 * zone's radix tree or the first node in the radix tree of the
764 * Returns true if there is a next node, false otherwise.
766 static bool rtree_next_node(struct memory_bitmap
*bm
)
768 bm
->cur
.node
= list_entry(bm
->cur
.node
->list
.next
,
769 struct rtree_node
, list
);
770 if (&bm
->cur
.node
->list
!= &bm
->cur
.zone
->leaves
) {
771 bm
->cur
.node_pfn
+= BM_BITS_PER_BLOCK
;
772 bm
->cur
.node_bit
= 0;
773 touch_softlockup_watchdog();
777 /* No more nodes, goto next zone */
778 bm
->cur
.zone
= list_entry(bm
->cur
.zone
->list
.next
,
779 struct mem_zone_bm_rtree
, list
);
780 if (&bm
->cur
.zone
->list
!= &bm
->zones
) {
781 bm
->cur
.node
= list_entry(bm
->cur
.zone
->leaves
.next
,
782 struct rtree_node
, list
);
783 bm
->cur
.node_pfn
= 0;
784 bm
->cur
.node_bit
= 0;
793 * memory_bm_rtree_next_pfn - Find the next set bit in the bitmap @bm
795 * Starting from the last returned position this function searches
796 * for the next set bit in the memory bitmap and returns its
797 * number. If no more bit is set BM_END_OF_MAP is returned.
799 * It is required to run memory_bm_position_reset() before the
800 * first call to this function.
802 static unsigned long memory_bm_next_pfn(struct memory_bitmap
*bm
)
804 unsigned long bits
, pfn
, pages
;
808 pages
= bm
->cur
.zone
->end_pfn
- bm
->cur
.zone
->start_pfn
;
809 bits
= min(pages
- bm
->cur
.node_pfn
, BM_BITS_PER_BLOCK
);
810 bit
= find_next_bit(bm
->cur
.node
->data
, bits
,
813 pfn
= bm
->cur
.zone
->start_pfn
+ bm
->cur
.node_pfn
+ bit
;
814 bm
->cur
.node_bit
= bit
+ 1;
817 } while (rtree_next_node(bm
));
819 return BM_END_OF_MAP
;
823 * This structure represents a range of page frames the contents of which
824 * should not be saved during the suspend.
827 struct nosave_region
{
828 struct list_head list
;
829 unsigned long start_pfn
;
830 unsigned long end_pfn
;
833 static LIST_HEAD(nosave_regions
);
836 * register_nosave_region - register a range of page frames the contents
837 * of which should not be saved during the suspend (to be used in the early
838 * initialization code)
842 __register_nosave_region(unsigned long start_pfn
, unsigned long end_pfn
,
845 struct nosave_region
*region
;
847 if (start_pfn
>= end_pfn
)
850 if (!list_empty(&nosave_regions
)) {
851 /* Try to extend the previous region (they should be sorted) */
852 region
= list_entry(nosave_regions
.prev
,
853 struct nosave_region
, list
);
854 if (region
->end_pfn
== start_pfn
) {
855 region
->end_pfn
= end_pfn
;
860 /* during init, this shouldn't fail */
861 region
= kmalloc(sizeof(struct nosave_region
), GFP_KERNEL
);
864 /* This allocation cannot fail */
865 region
= memblock_virt_alloc(sizeof(struct nosave_region
), 0);
866 region
->start_pfn
= start_pfn
;
867 region
->end_pfn
= end_pfn
;
868 list_add_tail(®ion
->list
, &nosave_regions
);
870 printk(KERN_INFO
"PM: Registered nosave memory: [mem %#010llx-%#010llx]\n",
871 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
872 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
876 * Set bits in this map correspond to the page frames the contents of which
877 * should not be saved during the suspend.
879 static struct memory_bitmap
*forbidden_pages_map
;
881 /* Set bits in this map correspond to free page frames. */
882 static struct memory_bitmap
*free_pages_map
;
885 * Each page frame allocated for creating the image is marked by setting the
886 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
889 void swsusp_set_page_free(struct page
*page
)
892 memory_bm_set_bit(free_pages_map
, page_to_pfn(page
));
895 static int swsusp_page_is_free(struct page
*page
)
897 return free_pages_map
?
898 memory_bm_test_bit(free_pages_map
, page_to_pfn(page
)) : 0;
901 void swsusp_unset_page_free(struct page
*page
)
904 memory_bm_clear_bit(free_pages_map
, page_to_pfn(page
));
907 static void swsusp_set_page_forbidden(struct page
*page
)
909 if (forbidden_pages_map
)
910 memory_bm_set_bit(forbidden_pages_map
, page_to_pfn(page
));
913 int swsusp_page_is_forbidden(struct page
*page
)
915 return forbidden_pages_map
?
916 memory_bm_test_bit(forbidden_pages_map
, page_to_pfn(page
)) : 0;
919 static void swsusp_unset_page_forbidden(struct page
*page
)
921 if (forbidden_pages_map
)
922 memory_bm_clear_bit(forbidden_pages_map
, page_to_pfn(page
));
926 * mark_nosave_pages - set bits corresponding to the page frames the
927 * contents of which should not be saved in a given bitmap.
930 static void mark_nosave_pages(struct memory_bitmap
*bm
)
932 struct nosave_region
*region
;
934 if (list_empty(&nosave_regions
))
937 list_for_each_entry(region
, &nosave_regions
, list
) {
940 pr_debug("PM: Marking nosave pages: [mem %#010llx-%#010llx]\n",
941 (unsigned long long) region
->start_pfn
<< PAGE_SHIFT
,
942 ((unsigned long long) region
->end_pfn
<< PAGE_SHIFT
)
945 for (pfn
= region
->start_pfn
; pfn
< region
->end_pfn
; pfn
++)
946 if (pfn_valid(pfn
)) {
948 * It is safe to ignore the result of
949 * mem_bm_set_bit_check() here, since we won't
950 * touch the PFNs for which the error is
953 mem_bm_set_bit_check(bm
, pfn
);
958 static bool is_nosave_page(unsigned long pfn
)
960 struct nosave_region
*region
;
962 list_for_each_entry(region
, &nosave_regions
, list
) {
963 if (pfn
>= region
->start_pfn
&& pfn
< region
->end_pfn
) {
964 pr_err("PM: %#010llx in e820 nosave region: "
965 "[mem %#010llx-%#010llx]\n",
966 (unsigned long long) pfn
<< PAGE_SHIFT
,
967 (unsigned long long) region
->start_pfn
<< PAGE_SHIFT
,
968 ((unsigned long long) region
->end_pfn
<< PAGE_SHIFT
)
978 * create_basic_memory_bitmaps - create bitmaps needed for marking page
979 * frames that should not be saved and free page frames. The pointers
980 * forbidden_pages_map and free_pages_map are only modified if everything
981 * goes well, because we don't want the bits to be used before both bitmaps
985 int create_basic_memory_bitmaps(void)
987 struct memory_bitmap
*bm1
, *bm2
;
990 if (forbidden_pages_map
&& free_pages_map
)
993 BUG_ON(forbidden_pages_map
|| free_pages_map
);
995 bm1
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
999 error
= memory_bm_create(bm1
, GFP_KERNEL
, PG_ANY
);
1001 goto Free_first_object
;
1003 bm2
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
1005 goto Free_first_bitmap
;
1007 error
= memory_bm_create(bm2
, GFP_KERNEL
, PG_ANY
);
1009 goto Free_second_object
;
1011 forbidden_pages_map
= bm1
;
1012 free_pages_map
= bm2
;
1013 mark_nosave_pages(forbidden_pages_map
);
1015 pr_debug("PM: Basic memory bitmaps created\n");
1022 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
1029 * free_basic_memory_bitmaps - free memory bitmaps allocated by
1030 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
1031 * so that the bitmaps themselves are not referred to while they are being
1035 void free_basic_memory_bitmaps(void)
1037 struct memory_bitmap
*bm1
, *bm2
;
1039 if (WARN_ON(!(forbidden_pages_map
&& free_pages_map
)))
1042 bm1
= forbidden_pages_map
;
1043 bm2
= free_pages_map
;
1044 forbidden_pages_map
= NULL
;
1045 free_pages_map
= NULL
;
1046 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
1048 memory_bm_free(bm2
, PG_UNSAFE_CLEAR
);
1051 pr_debug("PM: Basic memory bitmaps freed\n");
1055 * snapshot_additional_pages - estimate the number of additional pages
1056 * be needed for setting up the suspend image data structures for given
1057 * zone (usually the returned value is greater than the exact number)
1060 unsigned int snapshot_additional_pages(struct zone
*zone
)
1062 unsigned int rtree
, nodes
;
1064 rtree
= nodes
= DIV_ROUND_UP(zone
->spanned_pages
, BM_BITS_PER_BLOCK
);
1065 rtree
+= DIV_ROUND_UP(rtree
* sizeof(struct rtree_node
),
1066 LINKED_PAGE_DATA_SIZE
);
1068 nodes
= DIV_ROUND_UP(nodes
, BM_ENTRIES_PER_LEVEL
);
1075 #ifdef CONFIG_HIGHMEM
1077 * count_free_highmem_pages - compute the total number of free highmem
1078 * pages, system-wide.
1081 static unsigned int count_free_highmem_pages(void)
1084 unsigned int cnt
= 0;
1086 for_each_populated_zone(zone
)
1087 if (is_highmem(zone
))
1088 cnt
+= zone_page_state(zone
, NR_FREE_PAGES
);
1094 * saveable_highmem_page - Determine whether a highmem page should be
1095 * included in the suspend image.
1097 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1098 * and it isn't a part of a free chunk of pages.
1100 static struct page
*saveable_highmem_page(struct zone
*zone
, unsigned long pfn
)
1104 if (!pfn_valid(pfn
))
1107 page
= pfn_to_page(pfn
);
1108 if (page_zone(page
) != zone
)
1111 BUG_ON(!PageHighMem(page
));
1113 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
) ||
1117 if (page_is_guard(page
))
1124 * count_highmem_pages - compute the total number of saveable highmem
1128 static unsigned int count_highmem_pages(void)
1133 for_each_populated_zone(zone
) {
1134 unsigned long pfn
, max_zone_pfn
;
1136 if (!is_highmem(zone
))
1139 mark_free_pages(zone
);
1140 max_zone_pfn
= zone_end_pfn(zone
);
1141 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1142 if (saveable_highmem_page(zone
, pfn
))
1148 static inline void *saveable_highmem_page(struct zone
*z
, unsigned long p
)
1152 #endif /* CONFIG_HIGHMEM */
1155 * saveable_page - Determine whether a non-highmem page should be included
1156 * in the suspend image.
1158 * We should save the page if it isn't Nosave, and is not in the range
1159 * of pages statically defined as 'unsaveable', and it isn't a part of
1160 * a free chunk of pages.
1162 static struct page
*saveable_page(struct zone
*zone
, unsigned long pfn
)
1166 if (!pfn_valid(pfn
))
1169 page
= pfn_to_page(pfn
);
1170 if (page_zone(page
) != zone
)
1173 BUG_ON(PageHighMem(page
));
1175 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
))
1178 if (PageReserved(page
)
1179 && (!kernel_page_present(page
) || pfn_is_nosave(pfn
)))
1182 if (page_is_guard(page
))
1189 * count_data_pages - compute the total number of saveable non-highmem
1193 static unsigned int count_data_pages(void)
1196 unsigned long pfn
, max_zone_pfn
;
1199 for_each_populated_zone(zone
) {
1200 if (is_highmem(zone
))
1203 mark_free_pages(zone
);
1204 max_zone_pfn
= zone_end_pfn(zone
);
1205 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1206 if (saveable_page(zone
, pfn
))
1212 /* This is needed, because copy_page and memcpy are not usable for copying
1215 static inline void do_copy_page(long *dst
, long *src
)
1219 for (n
= PAGE_SIZE
/ sizeof(long); n
; n
--)
1225 * safe_copy_page - check if the page we are going to copy is marked as
1226 * present in the kernel page tables (this always is the case if
1227 * CONFIG_DEBUG_PAGEALLOC is not set and in that case
1228 * kernel_page_present() always returns 'true').
1230 static void safe_copy_page(void *dst
, struct page
*s_page
)
1232 if (kernel_page_present(s_page
)) {
1233 do_copy_page(dst
, page_address(s_page
));
1235 kernel_map_pages(s_page
, 1, 1);
1236 do_copy_page(dst
, page_address(s_page
));
1237 kernel_map_pages(s_page
, 1, 0);
1242 #ifdef CONFIG_HIGHMEM
1243 static inline struct page
*
1244 page_is_saveable(struct zone
*zone
, unsigned long pfn
)
1246 return is_highmem(zone
) ?
1247 saveable_highmem_page(zone
, pfn
) : saveable_page(zone
, pfn
);
1250 static void copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
1252 struct page
*s_page
, *d_page
;
1255 s_page
= pfn_to_page(src_pfn
);
1256 d_page
= pfn_to_page(dst_pfn
);
1257 if (PageHighMem(s_page
)) {
1258 src
= kmap_atomic(s_page
);
1259 dst
= kmap_atomic(d_page
);
1260 do_copy_page(dst
, src
);
1264 if (PageHighMem(d_page
)) {
1265 /* Page pointed to by src may contain some kernel
1266 * data modified by kmap_atomic()
1268 safe_copy_page(buffer
, s_page
);
1269 dst
= kmap_atomic(d_page
);
1270 copy_page(dst
, buffer
);
1273 safe_copy_page(page_address(d_page
), s_page
);
1278 #define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1280 static inline void copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
1282 safe_copy_page(page_address(pfn_to_page(dst_pfn
)),
1283 pfn_to_page(src_pfn
));
1285 #endif /* CONFIG_HIGHMEM */
1288 copy_data_pages(struct memory_bitmap
*copy_bm
, struct memory_bitmap
*orig_bm
)
1293 for_each_populated_zone(zone
) {
1294 unsigned long max_zone_pfn
;
1296 mark_free_pages(zone
);
1297 max_zone_pfn
= zone_end_pfn(zone
);
1298 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1299 if (page_is_saveable(zone
, pfn
))
1300 memory_bm_set_bit(orig_bm
, pfn
);
1302 memory_bm_position_reset(orig_bm
);
1303 memory_bm_position_reset(copy_bm
);
1305 pfn
= memory_bm_next_pfn(orig_bm
);
1306 if (unlikely(pfn
== BM_END_OF_MAP
))
1308 copy_data_page(memory_bm_next_pfn(copy_bm
), pfn
);
1312 /* Total number of image pages */
1313 static unsigned int nr_copy_pages
;
1314 /* Number of pages needed for saving the original pfns of the image pages */
1315 static unsigned int nr_meta_pages
;
1317 * Numbers of normal and highmem page frames allocated for hibernation image
1318 * before suspending devices.
1320 unsigned int alloc_normal
, alloc_highmem
;
1322 * Memory bitmap used for marking saveable pages (during hibernation) or
1323 * hibernation image pages (during restore)
1325 static struct memory_bitmap orig_bm
;
1327 * Memory bitmap used during hibernation for marking allocated page frames that
1328 * will contain copies of saveable pages. During restore it is initially used
1329 * for marking hibernation image pages, but then the set bits from it are
1330 * duplicated in @orig_bm and it is released. On highmem systems it is next
1331 * used for marking "safe" highmem pages, but it has to be reinitialized for
1334 static struct memory_bitmap copy_bm
;
1337 * swsusp_free - free pages allocated for the suspend.
1339 * Suspend pages are alocated before the atomic copy is made, so we
1340 * need to release them after the resume.
1343 void swsusp_free(void)
1345 unsigned long fb_pfn
, fr_pfn
;
1347 if (!forbidden_pages_map
|| !free_pages_map
)
1350 memory_bm_position_reset(forbidden_pages_map
);
1351 memory_bm_position_reset(free_pages_map
);
1354 fr_pfn
= memory_bm_next_pfn(free_pages_map
);
1355 fb_pfn
= memory_bm_next_pfn(forbidden_pages_map
);
1358 * Find the next bit set in both bitmaps. This is guaranteed to
1359 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1362 if (fb_pfn
< fr_pfn
)
1363 fb_pfn
= memory_bm_next_pfn(forbidden_pages_map
);
1364 if (fr_pfn
< fb_pfn
)
1365 fr_pfn
= memory_bm_next_pfn(free_pages_map
);
1366 } while (fb_pfn
!= fr_pfn
);
1368 if (fr_pfn
!= BM_END_OF_MAP
&& pfn_valid(fr_pfn
)) {
1369 struct page
*page
= pfn_to_page(fr_pfn
);
1371 memory_bm_clear_current(forbidden_pages_map
);
1372 memory_bm_clear_current(free_pages_map
);
1380 restore_pblist
= NULL
;
1386 /* Helper functions used for the shrinking of memory. */
1388 #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1391 * preallocate_image_pages - Allocate a number of pages for hibernation image
1392 * @nr_pages: Number of page frames to allocate.
1393 * @mask: GFP flags to use for the allocation.
1395 * Return value: Number of page frames actually allocated
1397 static unsigned long preallocate_image_pages(unsigned long nr_pages
, gfp_t mask
)
1399 unsigned long nr_alloc
= 0;
1401 while (nr_pages
> 0) {
1404 page
= alloc_image_page(mask
);
1407 memory_bm_set_bit(©_bm
, page_to_pfn(page
));
1408 if (PageHighMem(page
))
1419 static unsigned long preallocate_image_memory(unsigned long nr_pages
,
1420 unsigned long avail_normal
)
1422 unsigned long alloc
;
1424 if (avail_normal
<= alloc_normal
)
1427 alloc
= avail_normal
- alloc_normal
;
1428 if (nr_pages
< alloc
)
1431 return preallocate_image_pages(alloc
, GFP_IMAGE
);
1434 #ifdef CONFIG_HIGHMEM
1435 static unsigned long preallocate_image_highmem(unsigned long nr_pages
)
1437 return preallocate_image_pages(nr_pages
, GFP_IMAGE
| __GFP_HIGHMEM
);
1441 * __fraction - Compute (an approximation of) x * (multiplier / base)
1443 static unsigned long __fraction(u64 x
, u64 multiplier
, u64 base
)
1447 return (unsigned long)x
;
1450 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages
,
1451 unsigned long highmem
,
1452 unsigned long total
)
1454 unsigned long alloc
= __fraction(nr_pages
, highmem
, total
);
1456 return preallocate_image_pages(alloc
, GFP_IMAGE
| __GFP_HIGHMEM
);
1458 #else /* CONFIG_HIGHMEM */
1459 static inline unsigned long preallocate_image_highmem(unsigned long nr_pages
)
1464 static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages
,
1465 unsigned long highmem
,
1466 unsigned long total
)
1470 #endif /* CONFIG_HIGHMEM */
1473 * free_unnecessary_pages - Release preallocated pages not needed for the image
1475 static void free_unnecessary_pages(void)
1477 unsigned long save
, to_free_normal
, to_free_highmem
;
1479 save
= count_data_pages();
1480 if (alloc_normal
>= save
) {
1481 to_free_normal
= alloc_normal
- save
;
1485 save
-= alloc_normal
;
1487 save
+= count_highmem_pages();
1488 if (alloc_highmem
>= save
) {
1489 to_free_highmem
= alloc_highmem
- save
;
1491 to_free_highmem
= 0;
1492 save
-= alloc_highmem
;
1493 if (to_free_normal
> save
)
1494 to_free_normal
-= save
;
1499 memory_bm_position_reset(©_bm
);
1501 while (to_free_normal
> 0 || to_free_highmem
> 0) {
1502 unsigned long pfn
= memory_bm_next_pfn(©_bm
);
1503 struct page
*page
= pfn_to_page(pfn
);
1505 if (PageHighMem(page
)) {
1506 if (!to_free_highmem
)
1511 if (!to_free_normal
)
1516 memory_bm_clear_bit(©_bm
, pfn
);
1517 swsusp_unset_page_forbidden(page
);
1518 swsusp_unset_page_free(page
);
1524 * minimum_image_size - Estimate the minimum acceptable size of an image
1525 * @saveable: Number of saveable pages in the system.
1527 * We want to avoid attempting to free too much memory too hard, so estimate the
1528 * minimum acceptable size of a hibernation image to use as the lower limit for
1529 * preallocating memory.
1531 * We assume that the minimum image size should be proportional to
1533 * [number of saveable pages] - [number of pages that can be freed in theory]
1535 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1536 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages,
1537 * minus mapped file pages.
1539 static unsigned long minimum_image_size(unsigned long saveable
)
1543 size
= global_page_state(NR_SLAB_RECLAIMABLE
)
1544 + global_page_state(NR_ACTIVE_ANON
)
1545 + global_page_state(NR_INACTIVE_ANON
)
1546 + global_page_state(NR_ACTIVE_FILE
)
1547 + global_page_state(NR_INACTIVE_FILE
)
1548 - global_page_state(NR_FILE_MAPPED
);
1550 return saveable
<= size
? 0 : saveable
- size
;
1554 * hibernate_preallocate_memory - Preallocate memory for hibernation image
1556 * To create a hibernation image it is necessary to make a copy of every page
1557 * frame in use. We also need a number of page frames to be free during
1558 * hibernation for allocations made while saving the image and for device
1559 * drivers, in case they need to allocate memory from their hibernation
1560 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1561 * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
1562 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1563 * total number of available page frames and allocate at least
1565 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1566 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1568 * of them, which corresponds to the maximum size of a hibernation image.
1570 * If image_size is set below the number following from the above formula,
1571 * the preallocation of memory is continued until the total number of saveable
1572 * pages in the system is below the requested image size or the minimum
1573 * acceptable image size returned by minimum_image_size(), whichever is greater.
1575 int hibernate_preallocate_memory(void)
1578 unsigned long saveable
, size
, max_size
, count
, highmem
, pages
= 0;
1579 unsigned long alloc
, save_highmem
, pages_highmem
, avail_normal
;
1580 ktime_t start
, stop
;
1583 printk(KERN_INFO
"PM: Preallocating image memory... ");
1584 start
= ktime_get();
1586 error
= memory_bm_create(&orig_bm
, GFP_IMAGE
, PG_ANY
);
1590 error
= memory_bm_create(©_bm
, GFP_IMAGE
, PG_ANY
);
1597 /* Count the number of saveable data pages. */
1598 save_highmem
= count_highmem_pages();
1599 saveable
= count_data_pages();
1602 * Compute the total number of page frames we can use (count) and the
1603 * number of pages needed for image metadata (size).
1606 saveable
+= save_highmem
;
1607 highmem
= save_highmem
;
1609 for_each_populated_zone(zone
) {
1610 size
+= snapshot_additional_pages(zone
);
1611 if (is_highmem(zone
))
1612 highmem
+= zone_page_state(zone
, NR_FREE_PAGES
);
1614 count
+= zone_page_state(zone
, NR_FREE_PAGES
);
1616 avail_normal
= count
;
1618 count
-= totalreserve_pages
;
1620 /* Add number of pages required for page keys (s390 only). */
1621 size
+= page_key_additional_pages(saveable
);
1623 /* Compute the maximum number of saveable pages to leave in memory. */
1624 max_size
= (count
- (size
+ PAGES_FOR_IO
)) / 2
1625 - 2 * DIV_ROUND_UP(reserved_size
, PAGE_SIZE
);
1626 /* Compute the desired number of image pages specified by image_size. */
1627 size
= DIV_ROUND_UP(image_size
, PAGE_SIZE
);
1628 if (size
> max_size
)
1631 * If the desired number of image pages is at least as large as the
1632 * current number of saveable pages in memory, allocate page frames for
1633 * the image and we're done.
1635 if (size
>= saveable
) {
1636 pages
= preallocate_image_highmem(save_highmem
);
1637 pages
+= preallocate_image_memory(saveable
- pages
, avail_normal
);
1641 /* Estimate the minimum size of the image. */
1642 pages
= minimum_image_size(saveable
);
1644 * To avoid excessive pressure on the normal zone, leave room in it to
1645 * accommodate an image of the minimum size (unless it's already too
1646 * small, in which case don't preallocate pages from it at all).
1648 if (avail_normal
> pages
)
1649 avail_normal
-= pages
;
1653 size
= min_t(unsigned long, pages
, max_size
);
1656 * Let the memory management subsystem know that we're going to need a
1657 * large number of page frames to allocate and make it free some memory.
1658 * NOTE: If this is not done, performance will be hurt badly in some
1661 shrink_all_memory(saveable
- size
);
1664 * The number of saveable pages in memory was too high, so apply some
1665 * pressure to decrease it. First, make room for the largest possible
1666 * image and fail if that doesn't work. Next, try to decrease the size
1667 * of the image as much as indicated by 'size' using allocations from
1668 * highmem and non-highmem zones separately.
1670 pages_highmem
= preallocate_image_highmem(highmem
/ 2);
1671 alloc
= count
- max_size
;
1672 if (alloc
> pages_highmem
)
1673 alloc
-= pages_highmem
;
1676 pages
= preallocate_image_memory(alloc
, avail_normal
);
1677 if (pages
< alloc
) {
1678 /* We have exhausted non-highmem pages, try highmem. */
1680 pages
+= pages_highmem
;
1681 pages_highmem
= preallocate_image_highmem(alloc
);
1682 if (pages_highmem
< alloc
)
1684 pages
+= pages_highmem
;
1686 * size is the desired number of saveable pages to leave in
1687 * memory, so try to preallocate (all memory - size) pages.
1689 alloc
= (count
- pages
) - size
;
1690 pages
+= preallocate_image_highmem(alloc
);
1693 * There are approximately max_size saveable pages at this point
1694 * and we want to reduce this number down to size.
1696 alloc
= max_size
- size
;
1697 size
= preallocate_highmem_fraction(alloc
, highmem
, count
);
1698 pages_highmem
+= size
;
1700 size
= preallocate_image_memory(alloc
, avail_normal
);
1701 pages_highmem
+= preallocate_image_highmem(alloc
- size
);
1702 pages
+= pages_highmem
+ size
;
1706 * We only need as many page frames for the image as there are saveable
1707 * pages in memory, but we have allocated more. Release the excessive
1710 free_unnecessary_pages();
1714 printk(KERN_CONT
"done (allocated %lu pages)\n", pages
);
1715 swsusp_show_speed(start
, stop
, pages
, "Allocated");
1720 printk(KERN_CONT
"\n");
1725 #ifdef CONFIG_HIGHMEM
1727 * count_pages_for_highmem - compute the number of non-highmem pages
1728 * that will be necessary for creating copies of highmem pages.
1731 static unsigned int count_pages_for_highmem(unsigned int nr_highmem
)
1733 unsigned int free_highmem
= count_free_highmem_pages() + alloc_highmem
;
1735 if (free_highmem
>= nr_highmem
)
1738 nr_highmem
-= free_highmem
;
1744 count_pages_for_highmem(unsigned int nr_highmem
) { return 0; }
1745 #endif /* CONFIG_HIGHMEM */
1748 * enough_free_mem - Make sure we have enough free memory for the
1752 static int enough_free_mem(unsigned int nr_pages
, unsigned int nr_highmem
)
1755 unsigned int free
= alloc_normal
;
1757 for_each_populated_zone(zone
)
1758 if (!is_highmem(zone
))
1759 free
+= zone_page_state(zone
, NR_FREE_PAGES
);
1761 nr_pages
+= count_pages_for_highmem(nr_highmem
);
1762 pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n",
1763 nr_pages
, PAGES_FOR_IO
, free
);
1765 return free
> nr_pages
+ PAGES_FOR_IO
;
1768 #ifdef CONFIG_HIGHMEM
1770 * get_highmem_buffer - if there are some highmem pages in the suspend
1771 * image, we may need the buffer to copy them and/or load their data.
1774 static inline int get_highmem_buffer(int safe_needed
)
1776 buffer
= get_image_page(GFP_ATOMIC
| __GFP_COLD
, safe_needed
);
1777 return buffer
? 0 : -ENOMEM
;
1781 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1782 * Try to allocate as many pages as needed, but if the number of free
1783 * highmem pages is lesser than that, allocate them all.
1786 static inline unsigned int
1787 alloc_highmem_pages(struct memory_bitmap
*bm
, unsigned int nr_highmem
)
1789 unsigned int to_alloc
= count_free_highmem_pages();
1791 if (to_alloc
> nr_highmem
)
1792 to_alloc
= nr_highmem
;
1794 nr_highmem
-= to_alloc
;
1795 while (to_alloc
-- > 0) {
1798 page
= alloc_image_page(__GFP_HIGHMEM
);
1799 memory_bm_set_bit(bm
, page_to_pfn(page
));
1804 static inline int get_highmem_buffer(int safe_needed
) { return 0; }
1806 static inline unsigned int
1807 alloc_highmem_pages(struct memory_bitmap
*bm
, unsigned int n
) { return 0; }
1808 #endif /* CONFIG_HIGHMEM */
1811 * swsusp_alloc - allocate memory for the suspend image
1813 * We first try to allocate as many highmem pages as there are
1814 * saveable highmem pages in the system. If that fails, we allocate
1815 * non-highmem pages for the copies of the remaining highmem ones.
1817 * In this approach it is likely that the copies of highmem pages will
1818 * also be located in the high memory, because of the way in which
1819 * copy_data_pages() works.
1823 swsusp_alloc(struct memory_bitmap
*orig_bm
, struct memory_bitmap
*copy_bm
,
1824 unsigned int nr_pages
, unsigned int nr_highmem
)
1826 if (nr_highmem
> 0) {
1827 if (get_highmem_buffer(PG_ANY
))
1829 if (nr_highmem
> alloc_highmem
) {
1830 nr_highmem
-= alloc_highmem
;
1831 nr_pages
+= alloc_highmem_pages(copy_bm
, nr_highmem
);
1834 if (nr_pages
> alloc_normal
) {
1835 nr_pages
-= alloc_normal
;
1836 while (nr_pages
-- > 0) {
1839 page
= alloc_image_page(GFP_ATOMIC
| __GFP_COLD
);
1842 memory_bm_set_bit(copy_bm
, page_to_pfn(page
));
1853 asmlinkage __visible
int swsusp_save(void)
1855 unsigned int nr_pages
, nr_highmem
;
1857 printk(KERN_INFO
"PM: Creating hibernation image:\n");
1859 drain_local_pages(NULL
);
1860 nr_pages
= count_data_pages();
1861 nr_highmem
= count_highmem_pages();
1862 printk(KERN_INFO
"PM: Need to copy %u pages\n", nr_pages
+ nr_highmem
);
1864 if (!enough_free_mem(nr_pages
, nr_highmem
)) {
1865 printk(KERN_ERR
"PM: Not enough free memory\n");
1869 if (swsusp_alloc(&orig_bm
, ©_bm
, nr_pages
, nr_highmem
)) {
1870 printk(KERN_ERR
"PM: Memory allocation failed\n");
1874 /* During allocating of suspend pagedir, new cold pages may appear.
1877 drain_local_pages(NULL
);
1878 copy_data_pages(©_bm
, &orig_bm
);
1881 * End of critical section. From now on, we can write to memory,
1882 * but we should not touch disk. This specially means we must _not_
1883 * touch swap space! Except we must write out our image of course.
1886 nr_pages
+= nr_highmem
;
1887 nr_copy_pages
= nr_pages
;
1888 nr_meta_pages
= DIV_ROUND_UP(nr_pages
* sizeof(long), PAGE_SIZE
);
1890 printk(KERN_INFO
"PM: Hibernation image created (%d pages copied)\n",
1896 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
1897 static int init_header_complete(struct swsusp_info
*info
)
1899 memcpy(&info
->uts
, init_utsname(), sizeof(struct new_utsname
));
1900 info
->version_code
= LINUX_VERSION_CODE
;
1904 static char *check_image_kernel(struct swsusp_info
*info
)
1906 if (info
->version_code
!= LINUX_VERSION_CODE
)
1907 return "kernel version";
1908 if (strcmp(info
->uts
.sysname
,init_utsname()->sysname
))
1909 return "system type";
1910 if (strcmp(info
->uts
.release
,init_utsname()->release
))
1911 return "kernel release";
1912 if (strcmp(info
->uts
.version
,init_utsname()->version
))
1914 if (strcmp(info
->uts
.machine
,init_utsname()->machine
))
1918 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1920 unsigned long snapshot_get_image_size(void)
1922 return nr_copy_pages
+ nr_meta_pages
+ 1;
1925 static int init_header(struct swsusp_info
*info
)
1927 memset(info
, 0, sizeof(struct swsusp_info
));
1928 info
->num_physpages
= get_num_physpages();
1929 info
->image_pages
= nr_copy_pages
;
1930 info
->pages
= snapshot_get_image_size();
1931 info
->size
= info
->pages
;
1932 info
->size
<<= PAGE_SHIFT
;
1933 return init_header_complete(info
);
1937 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1938 * are stored in the array @buf[] (1 page at a time)
1942 pack_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
1946 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
1947 buf
[j
] = memory_bm_next_pfn(bm
);
1948 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
1950 /* Save page key for data page (s390 only). */
1951 page_key_read(buf
+ j
);
1956 * snapshot_read_next - used for reading the system memory snapshot.
1958 * On the first call to it @handle should point to a zeroed
1959 * snapshot_handle structure. The structure gets updated and a pointer
1960 * to it should be passed to this function every next time.
1962 * On success the function returns a positive number. Then, the caller
1963 * is allowed to read up to the returned number of bytes from the memory
1964 * location computed by the data_of() macro.
1966 * The function returns 0 to indicate the end of data stream condition,
1967 * and a negative number is returned on error. In such cases the
1968 * structure pointed to by @handle is not updated and should not be used
1972 int snapshot_read_next(struct snapshot_handle
*handle
)
1974 if (handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
1978 /* This makes the buffer be freed by swsusp_free() */
1979 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
1986 error
= init_header((struct swsusp_info
*)buffer
);
1989 handle
->buffer
= buffer
;
1990 memory_bm_position_reset(&orig_bm
);
1991 memory_bm_position_reset(©_bm
);
1992 } else if (handle
->cur
<= nr_meta_pages
) {
1994 pack_pfns(buffer
, &orig_bm
);
1998 page
= pfn_to_page(memory_bm_next_pfn(©_bm
));
1999 if (PageHighMem(page
)) {
2000 /* Highmem pages are copied to the buffer,
2001 * because we can't return with a kmapped
2002 * highmem page (we may not be called again).
2006 kaddr
= kmap_atomic(page
);
2007 copy_page(buffer
, kaddr
);
2008 kunmap_atomic(kaddr
);
2009 handle
->buffer
= buffer
;
2011 handle
->buffer
= page_address(page
);
2019 * mark_unsafe_pages - mark the pages that cannot be used for storing
2020 * the image during resume, because they conflict with the pages that
2021 * had been used before suspend
2024 static int mark_unsafe_pages(struct memory_bitmap
*bm
)
2027 unsigned long pfn
, max_zone_pfn
;
2029 /* Clear page flags */
2030 for_each_populated_zone(zone
) {
2031 max_zone_pfn
= zone_end_pfn(zone
);
2032 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2034 swsusp_unset_page_free(pfn_to_page(pfn
));
2037 /* Mark pages that correspond to the "original" pfns as "unsafe" */
2038 memory_bm_position_reset(bm
);
2040 pfn
= memory_bm_next_pfn(bm
);
2041 if (likely(pfn
!= BM_END_OF_MAP
)) {
2042 if (likely(pfn_valid(pfn
)) && !is_nosave_page(pfn
))
2043 swsusp_set_page_free(pfn_to_page(pfn
));
2047 } while (pfn
!= BM_END_OF_MAP
);
2049 allocated_unsafe_pages
= 0;
2055 duplicate_memory_bitmap(struct memory_bitmap
*dst
, struct memory_bitmap
*src
)
2059 memory_bm_position_reset(src
);
2060 pfn
= memory_bm_next_pfn(src
);
2061 while (pfn
!= BM_END_OF_MAP
) {
2062 memory_bm_set_bit(dst
, pfn
);
2063 pfn
= memory_bm_next_pfn(src
);
2067 static int check_header(struct swsusp_info
*info
)
2071 reason
= check_image_kernel(info
);
2072 if (!reason
&& info
->num_physpages
!= get_num_physpages())
2073 reason
= "memory size";
2075 printk(KERN_ERR
"PM: Image mismatch: %s\n", reason
);
2082 * load header - check the image header and copy data from it
2086 load_header(struct swsusp_info
*info
)
2090 restore_pblist
= NULL
;
2091 error
= check_header(info
);
2093 nr_copy_pages
= info
->image_pages
;
2094 nr_meta_pages
= info
->pages
- info
->image_pages
- 1;
2100 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
2101 * the corresponding bit in the memory bitmap @bm
2103 static int unpack_orig_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
2107 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
2108 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
2111 /* Extract and buffer page key for data page (s390 only). */
2112 page_key_memorize(buf
+ j
);
2114 if (memory_bm_pfn_present(bm
, buf
[j
]))
2115 memory_bm_set_bit(bm
, buf
[j
]);
2123 /* List of "safe" pages that may be used to store data loaded from the suspend
2126 static struct linked_page
*safe_pages_list
;
2128 #ifdef CONFIG_HIGHMEM
2129 /* struct highmem_pbe is used for creating the list of highmem pages that
2130 * should be restored atomically during the resume from disk, because the page
2131 * frames they have occupied before the suspend are in use.
2133 struct highmem_pbe
{
2134 struct page
*copy_page
; /* data is here now */
2135 struct page
*orig_page
; /* data was here before the suspend */
2136 struct highmem_pbe
*next
;
2139 /* List of highmem PBEs needed for restoring the highmem pages that were
2140 * allocated before the suspend and included in the suspend image, but have
2141 * also been allocated by the "resume" kernel, so their contents cannot be
2142 * written directly to their "original" page frames.
2144 static struct highmem_pbe
*highmem_pblist
;
2147 * count_highmem_image_pages - compute the number of highmem pages in the
2148 * suspend image. The bits in the memory bitmap @bm that correspond to the
2149 * image pages are assumed to be set.
2152 static unsigned int count_highmem_image_pages(struct memory_bitmap
*bm
)
2155 unsigned int cnt
= 0;
2157 memory_bm_position_reset(bm
);
2158 pfn
= memory_bm_next_pfn(bm
);
2159 while (pfn
!= BM_END_OF_MAP
) {
2160 if (PageHighMem(pfn_to_page(pfn
)))
2163 pfn
= memory_bm_next_pfn(bm
);
2169 * prepare_highmem_image - try to allocate as many highmem pages as
2170 * there are highmem image pages (@nr_highmem_p points to the variable
2171 * containing the number of highmem image pages). The pages that are
2172 * "safe" (ie. will not be overwritten when the suspend image is
2173 * restored) have the corresponding bits set in @bm (it must be
2176 * NOTE: This function should not be called if there are no highmem
2180 static unsigned int safe_highmem_pages
;
2182 static struct memory_bitmap
*safe_highmem_bm
;
2185 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
2187 unsigned int to_alloc
;
2189 if (memory_bm_create(bm
, GFP_ATOMIC
, PG_SAFE
))
2192 if (get_highmem_buffer(PG_SAFE
))
2195 to_alloc
= count_free_highmem_pages();
2196 if (to_alloc
> *nr_highmem_p
)
2197 to_alloc
= *nr_highmem_p
;
2199 *nr_highmem_p
= to_alloc
;
2201 safe_highmem_pages
= 0;
2202 while (to_alloc
-- > 0) {
2205 page
= alloc_page(__GFP_HIGHMEM
);
2206 if (!swsusp_page_is_free(page
)) {
2207 /* The page is "safe", set its bit the bitmap */
2208 memory_bm_set_bit(bm
, page_to_pfn(page
));
2209 safe_highmem_pages
++;
2211 /* Mark the page as allocated */
2212 swsusp_set_page_forbidden(page
);
2213 swsusp_set_page_free(page
);
2215 memory_bm_position_reset(bm
);
2216 safe_highmem_bm
= bm
;
2221 * get_highmem_page_buffer - for given highmem image page find the buffer
2222 * that suspend_write_next() should set for its caller to write to.
2224 * If the page is to be saved to its "original" page frame or a copy of
2225 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2226 * the copy of the page is to be made in normal memory, so the address of
2227 * the copy is returned.
2229 * If @buffer is returned, the caller of suspend_write_next() will write
2230 * the page's contents to @buffer, so they will have to be copied to the
2231 * right location on the next call to suspend_write_next() and it is done
2232 * with the help of copy_last_highmem_page(). For this purpose, if
2233 * @buffer is returned, @last_highmem page is set to the page to which
2234 * the data will have to be copied from @buffer.
2237 static struct page
*last_highmem_page
;
2240 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
2242 struct highmem_pbe
*pbe
;
2245 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
)) {
2246 /* We have allocated the "original" page frame and we can
2247 * use it directly to store the loaded page.
2249 last_highmem_page
= page
;
2252 /* The "original" page frame has not been allocated and we have to
2253 * use a "safe" page frame to store the loaded page.
2255 pbe
= chain_alloc(ca
, sizeof(struct highmem_pbe
));
2258 return ERR_PTR(-ENOMEM
);
2260 pbe
->orig_page
= page
;
2261 if (safe_highmem_pages
> 0) {
2264 /* Copy of the page will be stored in high memory */
2266 tmp
= pfn_to_page(memory_bm_next_pfn(safe_highmem_bm
));
2267 safe_highmem_pages
--;
2268 last_highmem_page
= tmp
;
2269 pbe
->copy_page
= tmp
;
2271 /* Copy of the page will be stored in normal memory */
2272 kaddr
= safe_pages_list
;
2273 safe_pages_list
= safe_pages_list
->next
;
2274 pbe
->copy_page
= virt_to_page(kaddr
);
2276 pbe
->next
= highmem_pblist
;
2277 highmem_pblist
= pbe
;
2282 * copy_last_highmem_page - copy the contents of a highmem image from
2283 * @buffer, where the caller of snapshot_write_next() has place them,
2284 * to the right location represented by @last_highmem_page .
2287 static void copy_last_highmem_page(void)
2289 if (last_highmem_page
) {
2292 dst
= kmap_atomic(last_highmem_page
);
2293 copy_page(dst
, buffer
);
2295 last_highmem_page
= NULL
;
2299 static inline int last_highmem_page_copied(void)
2301 return !last_highmem_page
;
2304 static inline void free_highmem_data(void)
2306 if (safe_highmem_bm
)
2307 memory_bm_free(safe_highmem_bm
, PG_UNSAFE_CLEAR
);
2310 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
2313 static inline int get_safe_write_buffer(void) { return 0; }
2316 count_highmem_image_pages(struct memory_bitmap
*bm
) { return 0; }
2319 prepare_highmem_image(struct memory_bitmap
*bm
, unsigned int *nr_highmem_p
)
2324 static inline void *
2325 get_highmem_page_buffer(struct page
*page
, struct chain_allocator
*ca
)
2327 return ERR_PTR(-EINVAL
);
2330 static inline void copy_last_highmem_page(void) {}
2331 static inline int last_highmem_page_copied(void) { return 1; }
2332 static inline void free_highmem_data(void) {}
2333 #endif /* CONFIG_HIGHMEM */
2336 * prepare_image - use the memory bitmap @bm to mark the pages that will
2337 * be overwritten in the process of restoring the system memory state
2338 * from the suspend image ("unsafe" pages) and allocate memory for the
2341 * The idea is to allocate a new memory bitmap first and then allocate
2342 * as many pages as needed for the image data, but not to assign these
2343 * pages to specific tasks initially. Instead, we just mark them as
2344 * allocated and create a lists of "safe" pages that will be used
2345 * later. On systems with high memory a list of "safe" highmem pages is
2349 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2352 prepare_image(struct memory_bitmap
*new_bm
, struct memory_bitmap
*bm
)
2354 unsigned int nr_pages
, nr_highmem
;
2355 struct linked_page
*sp_list
, *lp
;
2358 /* If there is no highmem, the buffer will not be necessary */
2359 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
2362 nr_highmem
= count_highmem_image_pages(bm
);
2363 error
= mark_unsafe_pages(bm
);
2367 error
= memory_bm_create(new_bm
, GFP_ATOMIC
, PG_SAFE
);
2371 duplicate_memory_bitmap(new_bm
, bm
);
2372 memory_bm_free(bm
, PG_UNSAFE_KEEP
);
2373 if (nr_highmem
> 0) {
2374 error
= prepare_highmem_image(bm
, &nr_highmem
);
2378 /* Reserve some safe pages for potential later use.
2380 * NOTE: This way we make sure there will be enough safe pages for the
2381 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2382 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2385 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
2386 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
2387 nr_pages
= DIV_ROUND_UP(nr_pages
, PBES_PER_LINKED_PAGE
);
2388 while (nr_pages
> 0) {
2389 lp
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
2398 /* Preallocate memory for the image */
2399 safe_pages_list
= NULL
;
2400 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
2401 while (nr_pages
> 0) {
2402 lp
= (struct linked_page
*)get_zeroed_page(GFP_ATOMIC
);
2407 if (!swsusp_page_is_free(virt_to_page(lp
))) {
2408 /* The page is "safe", add it to the list */
2409 lp
->next
= safe_pages_list
;
2410 safe_pages_list
= lp
;
2412 /* Mark the page as allocated */
2413 swsusp_set_page_forbidden(virt_to_page(lp
));
2414 swsusp_set_page_free(virt_to_page(lp
));
2417 /* Free the reserved safe pages so that chain_alloc() can use them */
2420 free_image_page(sp_list
, PG_UNSAFE_CLEAR
);
2431 * get_buffer - compute the address that snapshot_write_next() should
2432 * set for its caller to write to.
2435 static void *get_buffer(struct memory_bitmap
*bm
, struct chain_allocator
*ca
)
2439 unsigned long pfn
= memory_bm_next_pfn(bm
);
2441 if (pfn
== BM_END_OF_MAP
)
2442 return ERR_PTR(-EFAULT
);
2444 page
= pfn_to_page(pfn
);
2445 if (PageHighMem(page
))
2446 return get_highmem_page_buffer(page
, ca
);
2448 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
))
2449 /* We have allocated the "original" page frame and we can
2450 * use it directly to store the loaded page.
2452 return page_address(page
);
2454 /* The "original" page frame has not been allocated and we have to
2455 * use a "safe" page frame to store the loaded page.
2457 pbe
= chain_alloc(ca
, sizeof(struct pbe
));
2460 return ERR_PTR(-ENOMEM
);
2462 pbe
->orig_address
= page_address(page
);
2463 pbe
->address
= safe_pages_list
;
2464 safe_pages_list
= safe_pages_list
->next
;
2465 pbe
->next
= restore_pblist
;
2466 restore_pblist
= pbe
;
2467 return pbe
->address
;
2471 * snapshot_write_next - used for writing the system memory snapshot.
2473 * On the first call to it @handle should point to a zeroed
2474 * snapshot_handle structure. The structure gets updated and a pointer
2475 * to it should be passed to this function every next time.
2477 * On success the function returns a positive number. Then, the caller
2478 * is allowed to write up to the returned number of bytes to the memory
2479 * location computed by the data_of() macro.
2481 * The function returns 0 to indicate the "end of file" condition,
2482 * and a negative number is returned on error. In such cases the
2483 * structure pointed to by @handle is not updated and should not be used
2487 int snapshot_write_next(struct snapshot_handle
*handle
)
2489 static struct chain_allocator ca
;
2492 /* Check if we have already loaded the entire image */
2493 if (handle
->cur
> 1 && handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
2496 handle
->sync_read
= 1;
2500 /* This makes the buffer be freed by swsusp_free() */
2501 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
2506 handle
->buffer
= buffer
;
2507 } else if (handle
->cur
== 1) {
2508 error
= load_header(buffer
);
2512 error
= memory_bm_create(©_bm
, GFP_ATOMIC
, PG_ANY
);
2516 /* Allocate buffer for page keys. */
2517 error
= page_key_alloc(nr_copy_pages
);
2521 } else if (handle
->cur
<= nr_meta_pages
+ 1) {
2522 error
= unpack_orig_pfns(buffer
, ©_bm
);
2526 if (handle
->cur
== nr_meta_pages
+ 1) {
2527 error
= prepare_image(&orig_bm
, ©_bm
);
2531 chain_init(&ca
, GFP_ATOMIC
, PG_SAFE
);
2532 memory_bm_position_reset(&orig_bm
);
2533 restore_pblist
= NULL
;
2534 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
2535 handle
->sync_read
= 0;
2536 if (IS_ERR(handle
->buffer
))
2537 return PTR_ERR(handle
->buffer
);
2540 copy_last_highmem_page();
2541 /* Restore page key for data page (s390 only). */
2542 page_key_write(handle
->buffer
);
2543 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
2544 if (IS_ERR(handle
->buffer
))
2545 return PTR_ERR(handle
->buffer
);
2546 if (handle
->buffer
!= buffer
)
2547 handle
->sync_read
= 0;
2554 * snapshot_write_finalize - must be called after the last call to
2555 * snapshot_write_next() in case the last page in the image happens
2556 * to be a highmem page and its contents should be stored in the
2557 * highmem. Additionally, it releases the memory that will not be
2561 void snapshot_write_finalize(struct snapshot_handle
*handle
)
2563 copy_last_highmem_page();
2564 /* Restore page key for data page (s390 only). */
2565 page_key_write(handle
->buffer
);
2567 /* Free only if we have loaded the image entirely */
2568 if (handle
->cur
> 1 && handle
->cur
> nr_meta_pages
+ nr_copy_pages
) {
2569 memory_bm_free(&orig_bm
, PG_UNSAFE_CLEAR
);
2570 free_highmem_data();
2574 int snapshot_image_loaded(struct snapshot_handle
*handle
)
2576 return !(!nr_copy_pages
|| !last_highmem_page_copied() ||
2577 handle
->cur
<= nr_meta_pages
+ nr_copy_pages
);
2580 #ifdef CONFIG_HIGHMEM
2581 /* Assumes that @buf is ready and points to a "safe" page */
2583 swap_two_pages_data(struct page
*p1
, struct page
*p2
, void *buf
)
2585 void *kaddr1
, *kaddr2
;
2587 kaddr1
= kmap_atomic(p1
);
2588 kaddr2
= kmap_atomic(p2
);
2589 copy_page(buf
, kaddr1
);
2590 copy_page(kaddr1
, kaddr2
);
2591 copy_page(kaddr2
, buf
);
2592 kunmap_atomic(kaddr2
);
2593 kunmap_atomic(kaddr1
);
2597 * restore_highmem - for each highmem page that was allocated before
2598 * the suspend and included in the suspend image, and also has been
2599 * allocated by the "resume" kernel swap its current (ie. "before
2600 * resume") contents with the previous (ie. "before suspend") one.
2602 * If the resume eventually fails, we can call this function once
2603 * again and restore the "before resume" highmem state.
2606 int restore_highmem(void)
2608 struct highmem_pbe
*pbe
= highmem_pblist
;
2614 buf
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
2619 swap_two_pages_data(pbe
->copy_page
, pbe
->orig_page
, buf
);
2622 free_image_page(buf
, PG_UNSAFE_CLEAR
);
2625 #endif /* CONFIG_HIGHMEM */