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 <linux/uaccess.h>
34 #include <asm/mmu_context.h>
35 #include <asm/pgtable.h>
36 #include <asm/tlbflush.h>
41 #ifdef CONFIG_DEBUG_RODATA
42 static bool hibernate_restore_protection
;
43 static bool hibernate_restore_protection_active
;
45 void enable_restore_image_protection(void)
47 hibernate_restore_protection
= true;
50 static inline void hibernate_restore_protection_begin(void)
52 hibernate_restore_protection_active
= hibernate_restore_protection
;
55 static inline void hibernate_restore_protection_end(void)
57 hibernate_restore_protection_active
= false;
60 static inline void hibernate_restore_protect_page(void *page_address
)
62 if (hibernate_restore_protection_active
)
63 set_memory_ro((unsigned long)page_address
, 1);
66 static inline void hibernate_restore_unprotect_page(void *page_address
)
68 if (hibernate_restore_protection_active
)
69 set_memory_rw((unsigned long)page_address
, 1);
72 static inline void hibernate_restore_protection_begin(void) {}
73 static inline void hibernate_restore_protection_end(void) {}
74 static inline void hibernate_restore_protect_page(void *page_address
) {}
75 static inline void hibernate_restore_unprotect_page(void *page_address
) {}
76 #endif /* CONFIG_DEBUG_RODATA */
78 static int swsusp_page_is_free(struct page
*);
79 static void swsusp_set_page_forbidden(struct page
*);
80 static void swsusp_unset_page_forbidden(struct page
*);
83 * Number of bytes to reserve for memory allocations made by device drivers
84 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
85 * cause image creation to fail (tunable via /sys/power/reserved_size).
87 unsigned long reserved_size
;
89 void __init
hibernate_reserved_size_init(void)
91 reserved_size
= SPARE_PAGES
* PAGE_SIZE
;
95 * Preferred image size in bytes (tunable via /sys/power/image_size).
96 * When it is set to N, swsusp will do its best to ensure the image
97 * size will not exceed N bytes, but if that is impossible, it will
98 * try to create the smallest image possible.
100 unsigned long image_size
;
102 void __init
hibernate_image_size_init(void)
104 image_size
= ((totalram_pages
* 2) / 5) * PAGE_SIZE
;
108 * List of PBEs needed for restoring the pages that were allocated before
109 * the suspend and included in the suspend image, but have also been
110 * allocated by the "resume" kernel, so their contents cannot be written
111 * directly to their "original" page frames.
113 struct pbe
*restore_pblist
;
115 /* struct linked_page is used to build chains of pages */
117 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
120 struct linked_page
*next
;
121 char data
[LINKED_PAGE_DATA_SIZE
];
125 * List of "safe" pages (ie. pages that were not used by the image kernel
126 * before hibernation) that may be used as temporary storage for image kernel
129 static struct linked_page
*safe_pages_list
;
131 /* Pointer to an auxiliary buffer (1 page) */
136 #define PG_UNSAFE_CLEAR 1
137 #define PG_UNSAFE_KEEP 0
139 static unsigned int allocated_unsafe_pages
;
142 * get_image_page - Allocate a page for a hibernation image.
143 * @gfp_mask: GFP mask for the allocation.
144 * @safe_needed: Get pages that were not used before hibernation (restore only)
146 * During image restoration, for storing the PBE list and the image data, we can
147 * only use memory pages that do not conflict with the pages used before
148 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
149 * using allocated_unsafe_pages.
151 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
152 * swsusp_free() can release it.
154 static void *get_image_page(gfp_t gfp_mask
, int safe_needed
)
158 res
= (void *)get_zeroed_page(gfp_mask
);
160 while (res
&& swsusp_page_is_free(virt_to_page(res
))) {
161 /* The page is unsafe, mark it for swsusp_free() */
162 swsusp_set_page_forbidden(virt_to_page(res
));
163 allocated_unsafe_pages
++;
164 res
= (void *)get_zeroed_page(gfp_mask
);
167 swsusp_set_page_forbidden(virt_to_page(res
));
168 swsusp_set_page_free(virt_to_page(res
));
173 static void *__get_safe_page(gfp_t gfp_mask
)
175 if (safe_pages_list
) {
176 void *ret
= safe_pages_list
;
178 safe_pages_list
= safe_pages_list
->next
;
179 memset(ret
, 0, PAGE_SIZE
);
182 return get_image_page(gfp_mask
, PG_SAFE
);
185 unsigned long get_safe_page(gfp_t gfp_mask
)
187 return (unsigned long)__get_safe_page(gfp_mask
);
190 static struct page
*alloc_image_page(gfp_t gfp_mask
)
194 page
= alloc_page(gfp_mask
);
196 swsusp_set_page_forbidden(page
);
197 swsusp_set_page_free(page
);
202 static void recycle_safe_page(void *page_address
)
204 struct linked_page
*lp
= page_address
;
206 lp
->next
= safe_pages_list
;
207 safe_pages_list
= lp
;
211 * free_image_page - Free a page allocated for hibernation image.
212 * @addr: Address of the page to free.
213 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
215 * The page to free should have been allocated by get_image_page() (page flags
216 * set by it are affected).
218 static inline void free_image_page(void *addr
, int clear_nosave_free
)
222 BUG_ON(!virt_addr_valid(addr
));
224 page
= virt_to_page(addr
);
226 swsusp_unset_page_forbidden(page
);
227 if (clear_nosave_free
)
228 swsusp_unset_page_free(page
);
233 static inline void free_list_of_pages(struct linked_page
*list
,
234 int clear_page_nosave
)
237 struct linked_page
*lp
= list
->next
;
239 free_image_page(list
, clear_page_nosave
);
245 * struct chain_allocator is used for allocating small objects out of
246 * a linked list of pages called 'the chain'.
248 * The chain grows each time when there is no room for a new object in
249 * the current page. The allocated objects cannot be freed individually.
250 * It is only possible to free them all at once, by freeing the entire
253 * NOTE: The chain allocator may be inefficient if the allocated objects
254 * are not much smaller than PAGE_SIZE.
256 struct chain_allocator
{
257 struct linked_page
*chain
; /* the chain */
258 unsigned int used_space
; /* total size of objects allocated out
259 of the current page */
260 gfp_t gfp_mask
; /* mask for allocating pages */
261 int safe_needed
; /* if set, only "safe" pages are allocated */
264 static void chain_init(struct chain_allocator
*ca
, gfp_t gfp_mask
,
268 ca
->used_space
= LINKED_PAGE_DATA_SIZE
;
269 ca
->gfp_mask
= gfp_mask
;
270 ca
->safe_needed
= safe_needed
;
273 static void *chain_alloc(struct chain_allocator
*ca
, unsigned int size
)
277 if (LINKED_PAGE_DATA_SIZE
- ca
->used_space
< size
) {
278 struct linked_page
*lp
;
280 lp
= ca
->safe_needed
? __get_safe_page(ca
->gfp_mask
) :
281 get_image_page(ca
->gfp_mask
, PG_ANY
);
285 lp
->next
= ca
->chain
;
289 ret
= ca
->chain
->data
+ ca
->used_space
;
290 ca
->used_space
+= size
;
295 * Data types related to memory bitmaps.
297 * Memory bitmap is a structure consiting of many linked lists of
298 * objects. The main list's elements are of type struct zone_bitmap
299 * and each of them corresonds to one zone. For each zone bitmap
300 * object there is a list of objects of type struct bm_block that
301 * represent each blocks of bitmap in which information is stored.
303 * struct memory_bitmap contains a pointer to the main list of zone
304 * bitmap objects, a struct bm_position used for browsing the bitmap,
305 * and a pointer to the list of pages used for allocating all of the
306 * zone bitmap objects and bitmap block objects.
308 * NOTE: It has to be possible to lay out the bitmap in memory
309 * using only allocations of order 0. Additionally, the bitmap is
310 * designed to work with arbitrary number of zones (this is over the
311 * top for now, but let's avoid making unnecessary assumptions ;-).
313 * struct zone_bitmap contains a pointer to a list of bitmap block
314 * objects and a pointer to the bitmap block object that has been
315 * most recently used for setting bits. Additionally, it contains the
316 * PFNs that correspond to the start and end of the represented zone.
318 * struct bm_block contains a pointer to the memory page in which
319 * information is stored (in the form of a block of bitmap)
320 * It also contains the pfns that correspond to the start and end of
321 * the represented memory area.
323 * The memory bitmap is organized as a radix tree to guarantee fast random
324 * access to the bits. There is one radix tree for each zone (as returned
325 * from create_mem_extents).
327 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
328 * two linked lists for the nodes of the tree, one for the inner nodes and
329 * one for the leave nodes. The linked leave nodes are used for fast linear
330 * access of the memory bitmap.
332 * The struct rtree_node represents one node of the radix tree.
335 #define BM_END_OF_MAP (~0UL)
337 #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
338 #define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
339 #define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
342 * struct rtree_node is a wrapper struct to link the nodes
343 * of the rtree together for easy linear iteration over
344 * bits and easy freeing
347 struct list_head list
;
352 * struct mem_zone_bm_rtree represents a bitmap used for one
353 * populated memory zone.
355 struct mem_zone_bm_rtree
{
356 struct list_head list
; /* Link Zones together */
357 struct list_head nodes
; /* Radix Tree inner nodes */
358 struct list_head leaves
; /* Radix Tree leaves */
359 unsigned long start_pfn
; /* Zone start page frame */
360 unsigned long end_pfn
; /* Zone end page frame + 1 */
361 struct rtree_node
*rtree
; /* Radix Tree Root */
362 int levels
; /* Number of Radix Tree Levels */
363 unsigned int blocks
; /* Number of Bitmap Blocks */
366 /* strcut bm_position is used for browsing memory bitmaps */
369 struct mem_zone_bm_rtree
*zone
;
370 struct rtree_node
*node
;
371 unsigned long node_pfn
;
375 struct memory_bitmap
{
376 struct list_head zones
;
377 struct linked_page
*p_list
; /* list of pages used to store zone
378 bitmap objects and bitmap block
380 struct bm_position cur
; /* most recently used bit position */
383 /* Functions that operate on memory bitmaps */
385 #define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
386 #if BITS_PER_LONG == 32
387 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
389 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
391 #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
394 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
396 * This function is used to allocate inner nodes as well as the
397 * leave nodes of the radix tree. It also adds the node to the
398 * corresponding linked list passed in by the *list parameter.
400 static struct rtree_node
*alloc_rtree_node(gfp_t gfp_mask
, int safe_needed
,
401 struct chain_allocator
*ca
,
402 struct list_head
*list
)
404 struct rtree_node
*node
;
406 node
= chain_alloc(ca
, sizeof(struct rtree_node
));
410 node
->data
= get_image_page(gfp_mask
, safe_needed
);
414 list_add_tail(&node
->list
, list
);
420 * add_rtree_block - Add a new leave node to the radix tree.
422 * The leave nodes need to be allocated in order to keep the leaves
423 * linked list in order. This is guaranteed by the zone->blocks
426 static int add_rtree_block(struct mem_zone_bm_rtree
*zone
, gfp_t gfp_mask
,
427 int safe_needed
, struct chain_allocator
*ca
)
429 struct rtree_node
*node
, *block
, **dst
;
430 unsigned int levels_needed
, block_nr
;
433 block_nr
= zone
->blocks
;
436 /* How many levels do we need for this block nr? */
439 block_nr
>>= BM_RTREE_LEVEL_SHIFT
;
442 /* Make sure the rtree has enough levels */
443 for (i
= zone
->levels
; i
< levels_needed
; i
++) {
444 node
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
,
449 node
->data
[0] = (unsigned long)zone
->rtree
;
454 /* Allocate new block */
455 block
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
, &zone
->leaves
);
459 /* Now walk the rtree to insert the block */
462 block_nr
= zone
->blocks
;
463 for (i
= zone
->levels
; i
> 0; i
--) {
467 node
= alloc_rtree_node(gfp_mask
, safe_needed
, ca
,
474 index
= block_nr
>> ((i
- 1) * BM_RTREE_LEVEL_SHIFT
);
475 index
&= BM_RTREE_LEVEL_MASK
;
476 dst
= (struct rtree_node
**)&((*dst
)->data
[index
]);
486 static void free_zone_bm_rtree(struct mem_zone_bm_rtree
*zone
,
487 int clear_nosave_free
);
490 * create_zone_bm_rtree - Create a radix tree for one zone.
492 * Allocated the mem_zone_bm_rtree structure and initializes it.
493 * This function also allocated and builds the radix tree for the
496 static struct mem_zone_bm_rtree
*create_zone_bm_rtree(gfp_t gfp_mask
,
498 struct chain_allocator
*ca
,
502 struct mem_zone_bm_rtree
*zone
;
503 unsigned int i
, nr_blocks
;
507 zone
= chain_alloc(ca
, sizeof(struct mem_zone_bm_rtree
));
511 INIT_LIST_HEAD(&zone
->nodes
);
512 INIT_LIST_HEAD(&zone
->leaves
);
513 zone
->start_pfn
= start
;
515 nr_blocks
= DIV_ROUND_UP(pages
, BM_BITS_PER_BLOCK
);
517 for (i
= 0; i
< nr_blocks
; i
++) {
518 if (add_rtree_block(zone
, gfp_mask
, safe_needed
, ca
)) {
519 free_zone_bm_rtree(zone
, PG_UNSAFE_CLEAR
);
528 * free_zone_bm_rtree - Free the memory of the radix tree.
530 * Free all node pages of the radix tree. The mem_zone_bm_rtree
531 * structure itself is not freed here nor are the rtree_node
534 static void free_zone_bm_rtree(struct mem_zone_bm_rtree
*zone
,
535 int clear_nosave_free
)
537 struct rtree_node
*node
;
539 list_for_each_entry(node
, &zone
->nodes
, list
)
540 free_image_page(node
->data
, clear_nosave_free
);
542 list_for_each_entry(node
, &zone
->leaves
, list
)
543 free_image_page(node
->data
, clear_nosave_free
);
546 static void memory_bm_position_reset(struct memory_bitmap
*bm
)
548 bm
->cur
.zone
= list_entry(bm
->zones
.next
, struct mem_zone_bm_rtree
,
550 bm
->cur
.node
= list_entry(bm
->cur
.zone
->leaves
.next
,
551 struct rtree_node
, list
);
552 bm
->cur
.node_pfn
= 0;
553 bm
->cur
.node_bit
= 0;
556 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
);
559 struct list_head hook
;
565 * free_mem_extents - Free a list of memory extents.
566 * @list: List of extents to free.
568 static void free_mem_extents(struct list_head
*list
)
570 struct mem_extent
*ext
, *aux
;
572 list_for_each_entry_safe(ext
, aux
, list
, hook
) {
573 list_del(&ext
->hook
);
579 * create_mem_extents - Create a list of memory extents.
580 * @list: List to put the extents into.
581 * @gfp_mask: Mask to use for memory allocations.
583 * The extents represent contiguous ranges of PFNs.
585 static int create_mem_extents(struct list_head
*list
, gfp_t gfp_mask
)
589 INIT_LIST_HEAD(list
);
591 for_each_populated_zone(zone
) {
592 unsigned long zone_start
, zone_end
;
593 struct mem_extent
*ext
, *cur
, *aux
;
595 zone_start
= zone
->zone_start_pfn
;
596 zone_end
= zone_end_pfn(zone
);
598 list_for_each_entry(ext
, list
, hook
)
599 if (zone_start
<= ext
->end
)
602 if (&ext
->hook
== list
|| zone_end
< ext
->start
) {
603 /* New extent is necessary */
604 struct mem_extent
*new_ext
;
606 new_ext
= kzalloc(sizeof(struct mem_extent
), gfp_mask
);
608 free_mem_extents(list
);
611 new_ext
->start
= zone_start
;
612 new_ext
->end
= zone_end
;
613 list_add_tail(&new_ext
->hook
, &ext
->hook
);
617 /* Merge this zone's range of PFNs with the existing one */
618 if (zone_start
< ext
->start
)
619 ext
->start
= zone_start
;
620 if (zone_end
> ext
->end
)
623 /* More merging may be possible */
625 list_for_each_entry_safe_continue(cur
, aux
, list
, hook
) {
626 if (zone_end
< cur
->start
)
628 if (zone_end
< cur
->end
)
630 list_del(&cur
->hook
);
639 * memory_bm_create - Allocate memory for a memory bitmap.
641 static int memory_bm_create(struct memory_bitmap
*bm
, gfp_t gfp_mask
,
644 struct chain_allocator ca
;
645 struct list_head mem_extents
;
646 struct mem_extent
*ext
;
649 chain_init(&ca
, gfp_mask
, safe_needed
);
650 INIT_LIST_HEAD(&bm
->zones
);
652 error
= create_mem_extents(&mem_extents
, gfp_mask
);
656 list_for_each_entry(ext
, &mem_extents
, hook
) {
657 struct mem_zone_bm_rtree
*zone
;
659 zone
= create_zone_bm_rtree(gfp_mask
, safe_needed
, &ca
,
660 ext
->start
, ext
->end
);
665 list_add_tail(&zone
->list
, &bm
->zones
);
668 bm
->p_list
= ca
.chain
;
669 memory_bm_position_reset(bm
);
671 free_mem_extents(&mem_extents
);
675 bm
->p_list
= ca
.chain
;
676 memory_bm_free(bm
, PG_UNSAFE_CLEAR
);
681 * memory_bm_free - Free memory occupied by the memory bitmap.
682 * @bm: Memory bitmap.
684 static void memory_bm_free(struct memory_bitmap
*bm
, int clear_nosave_free
)
686 struct mem_zone_bm_rtree
*zone
;
688 list_for_each_entry(zone
, &bm
->zones
, list
)
689 free_zone_bm_rtree(zone
, clear_nosave_free
);
691 free_list_of_pages(bm
->p_list
, clear_nosave_free
);
693 INIT_LIST_HEAD(&bm
->zones
);
697 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
699 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
700 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
702 * Walk the radix tree to find the page containing the bit that represents @pfn
703 * and return the position of the bit in @addr and @bit_nr.
705 static int memory_bm_find_bit(struct memory_bitmap
*bm
, unsigned long pfn
,
706 void **addr
, unsigned int *bit_nr
)
708 struct mem_zone_bm_rtree
*curr
, *zone
;
709 struct rtree_node
*node
;
714 if (pfn
>= zone
->start_pfn
&& pfn
< zone
->end_pfn
)
719 /* Find the right zone */
720 list_for_each_entry(curr
, &bm
->zones
, list
) {
721 if (pfn
>= curr
->start_pfn
&& pfn
< curr
->end_pfn
) {
732 * We have found the zone. Now walk the radix tree to find the leaf node
736 if (((pfn
- zone
->start_pfn
) & ~BM_BLOCK_MASK
) == bm
->cur
.node_pfn
)
740 block_nr
= (pfn
- zone
->start_pfn
) >> BM_BLOCK_SHIFT
;
742 for (i
= zone
->levels
; i
> 0; i
--) {
745 index
= block_nr
>> ((i
- 1) * BM_RTREE_LEVEL_SHIFT
);
746 index
&= BM_RTREE_LEVEL_MASK
;
747 BUG_ON(node
->data
[index
] == 0);
748 node
= (struct rtree_node
*)node
->data
[index
];
752 /* Update last position */
755 bm
->cur
.node_pfn
= (pfn
- zone
->start_pfn
) & ~BM_BLOCK_MASK
;
757 /* Set return values */
759 *bit_nr
= (pfn
- zone
->start_pfn
) & BM_BLOCK_MASK
;
764 static void memory_bm_set_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
770 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
775 static int mem_bm_set_bit_check(struct memory_bitmap
*bm
, unsigned long pfn
)
781 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
788 static void memory_bm_clear_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
794 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
796 clear_bit(bit
, addr
);
799 static void memory_bm_clear_current(struct memory_bitmap
*bm
)
803 bit
= max(bm
->cur
.node_bit
- 1, 0);
804 clear_bit(bit
, bm
->cur
.node
->data
);
807 static int memory_bm_test_bit(struct memory_bitmap
*bm
, unsigned long pfn
)
813 error
= memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
815 return test_bit(bit
, addr
);
818 static bool memory_bm_pfn_present(struct memory_bitmap
*bm
, unsigned long pfn
)
823 return !memory_bm_find_bit(bm
, pfn
, &addr
, &bit
);
827 * rtree_next_node - Jump to the next leaf node.
829 * Set the position to the beginning of the next node in the
830 * memory bitmap. This is either the next node in the current
831 * zone's radix tree or the first node in the radix tree of the
834 * Return true if there is a next node, false otherwise.
836 static bool rtree_next_node(struct memory_bitmap
*bm
)
838 if (!list_is_last(&bm
->cur
.node
->list
, &bm
->cur
.zone
->leaves
)) {
839 bm
->cur
.node
= list_entry(bm
->cur
.node
->list
.next
,
840 struct rtree_node
, list
);
841 bm
->cur
.node_pfn
+= BM_BITS_PER_BLOCK
;
842 bm
->cur
.node_bit
= 0;
843 touch_softlockup_watchdog();
847 /* No more nodes, goto next zone */
848 if (!list_is_last(&bm
->cur
.zone
->list
, &bm
->zones
)) {
849 bm
->cur
.zone
= list_entry(bm
->cur
.zone
->list
.next
,
850 struct mem_zone_bm_rtree
, list
);
851 bm
->cur
.node
= list_entry(bm
->cur
.zone
->leaves
.next
,
852 struct rtree_node
, list
);
853 bm
->cur
.node_pfn
= 0;
854 bm
->cur
.node_bit
= 0;
863 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
864 * @bm: Memory bitmap.
866 * Starting from the last returned position this function searches for the next
867 * set bit in @bm and returns the PFN represented by it. If no more bits are
868 * set, BM_END_OF_MAP is returned.
870 * It is required to run memory_bm_position_reset() before the first call to
871 * this function for the given memory bitmap.
873 static unsigned long memory_bm_next_pfn(struct memory_bitmap
*bm
)
875 unsigned long bits
, pfn
, pages
;
879 pages
= bm
->cur
.zone
->end_pfn
- bm
->cur
.zone
->start_pfn
;
880 bits
= min(pages
- bm
->cur
.node_pfn
, BM_BITS_PER_BLOCK
);
881 bit
= find_next_bit(bm
->cur
.node
->data
, bits
,
884 pfn
= bm
->cur
.zone
->start_pfn
+ bm
->cur
.node_pfn
+ bit
;
885 bm
->cur
.node_bit
= bit
+ 1;
888 } while (rtree_next_node(bm
));
890 return BM_END_OF_MAP
;
894 * This structure represents a range of page frames the contents of which
895 * should not be saved during hibernation.
897 struct nosave_region
{
898 struct list_head list
;
899 unsigned long start_pfn
;
900 unsigned long end_pfn
;
903 static LIST_HEAD(nosave_regions
);
905 static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree
*zone
)
907 struct rtree_node
*node
;
909 list_for_each_entry(node
, &zone
->nodes
, list
)
910 recycle_safe_page(node
->data
);
912 list_for_each_entry(node
, &zone
->leaves
, list
)
913 recycle_safe_page(node
->data
);
916 static void memory_bm_recycle(struct memory_bitmap
*bm
)
918 struct mem_zone_bm_rtree
*zone
;
919 struct linked_page
*p_list
;
921 list_for_each_entry(zone
, &bm
->zones
, list
)
922 recycle_zone_bm_rtree(zone
);
926 struct linked_page
*lp
= p_list
;
929 recycle_safe_page(lp
);
934 * register_nosave_region - Register a region of unsaveable memory.
936 * Register a range of page frames the contents of which should not be saved
937 * during hibernation (to be used in the early initialization code).
939 void __init
__register_nosave_region(unsigned long start_pfn
,
940 unsigned long end_pfn
, int use_kmalloc
)
942 struct nosave_region
*region
;
944 if (start_pfn
>= end_pfn
)
947 if (!list_empty(&nosave_regions
)) {
948 /* Try to extend the previous region (they should be sorted) */
949 region
= list_entry(nosave_regions
.prev
,
950 struct nosave_region
, list
);
951 if (region
->end_pfn
== start_pfn
) {
952 region
->end_pfn
= end_pfn
;
957 /* During init, this shouldn't fail */
958 region
= kmalloc(sizeof(struct nosave_region
), GFP_KERNEL
);
961 /* This allocation cannot fail */
962 region
= memblock_virt_alloc(sizeof(struct nosave_region
), 0);
964 region
->start_pfn
= start_pfn
;
965 region
->end_pfn
= end_pfn
;
966 list_add_tail(®ion
->list
, &nosave_regions
);
968 printk(KERN_INFO
"PM: Registered nosave memory: [mem %#010llx-%#010llx]\n",
969 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
970 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
974 * Set bits in this map correspond to the page frames the contents of which
975 * should not be saved during the suspend.
977 static struct memory_bitmap
*forbidden_pages_map
;
979 /* Set bits in this map correspond to free page frames. */
980 static struct memory_bitmap
*free_pages_map
;
983 * Each page frame allocated for creating the image is marked by setting the
984 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
987 void swsusp_set_page_free(struct page
*page
)
990 memory_bm_set_bit(free_pages_map
, page_to_pfn(page
));
993 static int swsusp_page_is_free(struct page
*page
)
995 return free_pages_map
?
996 memory_bm_test_bit(free_pages_map
, page_to_pfn(page
)) : 0;
999 void swsusp_unset_page_free(struct page
*page
)
1002 memory_bm_clear_bit(free_pages_map
, page_to_pfn(page
));
1005 static void swsusp_set_page_forbidden(struct page
*page
)
1007 if (forbidden_pages_map
)
1008 memory_bm_set_bit(forbidden_pages_map
, page_to_pfn(page
));
1011 int swsusp_page_is_forbidden(struct page
*page
)
1013 return forbidden_pages_map
?
1014 memory_bm_test_bit(forbidden_pages_map
, page_to_pfn(page
)) : 0;
1017 static void swsusp_unset_page_forbidden(struct page
*page
)
1019 if (forbidden_pages_map
)
1020 memory_bm_clear_bit(forbidden_pages_map
, page_to_pfn(page
));
1024 * mark_nosave_pages - Mark pages that should not be saved.
1025 * @bm: Memory bitmap.
1027 * Set the bits in @bm that correspond to the page frames the contents of which
1028 * should not be saved.
1030 static void mark_nosave_pages(struct memory_bitmap
*bm
)
1032 struct nosave_region
*region
;
1034 if (list_empty(&nosave_regions
))
1037 list_for_each_entry(region
, &nosave_regions
, list
) {
1040 pr_debug("PM: Marking nosave pages: [mem %#010llx-%#010llx]\n",
1041 (unsigned long long) region
->start_pfn
<< PAGE_SHIFT
,
1042 ((unsigned long long) region
->end_pfn
<< PAGE_SHIFT
)
1045 for (pfn
= region
->start_pfn
; pfn
< region
->end_pfn
; pfn
++)
1046 if (pfn_valid(pfn
)) {
1048 * It is safe to ignore the result of
1049 * mem_bm_set_bit_check() here, since we won't
1050 * touch the PFNs for which the error is
1053 mem_bm_set_bit_check(bm
, pfn
);
1059 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1061 * Create bitmaps needed for marking page frames that should not be saved and
1062 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1063 * only modified if everything goes well, because we don't want the bits to be
1064 * touched before both bitmaps are set up.
1066 int create_basic_memory_bitmaps(void)
1068 struct memory_bitmap
*bm1
, *bm2
;
1071 if (forbidden_pages_map
&& free_pages_map
)
1074 BUG_ON(forbidden_pages_map
|| free_pages_map
);
1076 bm1
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
1080 error
= memory_bm_create(bm1
, GFP_KERNEL
, PG_ANY
);
1082 goto Free_first_object
;
1084 bm2
= kzalloc(sizeof(struct memory_bitmap
), GFP_KERNEL
);
1086 goto Free_first_bitmap
;
1088 error
= memory_bm_create(bm2
, GFP_KERNEL
, PG_ANY
);
1090 goto Free_second_object
;
1092 forbidden_pages_map
= bm1
;
1093 free_pages_map
= bm2
;
1094 mark_nosave_pages(forbidden_pages_map
);
1096 pr_debug("PM: Basic memory bitmaps created\n");
1103 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
1110 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1112 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1113 * auxiliary pointers are necessary so that the bitmaps themselves are not
1114 * referred to while they are being freed.
1116 void free_basic_memory_bitmaps(void)
1118 struct memory_bitmap
*bm1
, *bm2
;
1120 if (WARN_ON(!(forbidden_pages_map
&& free_pages_map
)))
1123 bm1
= forbidden_pages_map
;
1124 bm2
= free_pages_map
;
1125 forbidden_pages_map
= NULL
;
1126 free_pages_map
= NULL
;
1127 memory_bm_free(bm1
, PG_UNSAFE_CLEAR
);
1129 memory_bm_free(bm2
, PG_UNSAFE_CLEAR
);
1132 pr_debug("PM: Basic memory bitmaps freed\n");
1135 void clear_free_pages(void)
1137 #ifdef CONFIG_PAGE_POISONING_ZERO
1138 struct memory_bitmap
*bm
= free_pages_map
;
1141 if (WARN_ON(!(free_pages_map
)))
1144 memory_bm_position_reset(bm
);
1145 pfn
= memory_bm_next_pfn(bm
);
1146 while (pfn
!= BM_END_OF_MAP
) {
1148 clear_highpage(pfn_to_page(pfn
));
1150 pfn
= memory_bm_next_pfn(bm
);
1152 memory_bm_position_reset(bm
);
1153 pr_info("PM: free pages cleared after restore\n");
1154 #endif /* PAGE_POISONING_ZERO */
1158 * snapshot_additional_pages - Estimate the number of extra pages needed.
1159 * @zone: Memory zone to carry out the computation for.
1161 * Estimate the number of additional pages needed for setting up a hibernation
1162 * image data structures for @zone (usually, the returned value is greater than
1163 * the exact number).
1165 unsigned int snapshot_additional_pages(struct zone
*zone
)
1167 unsigned int rtree
, nodes
;
1169 rtree
= nodes
= DIV_ROUND_UP(zone
->spanned_pages
, BM_BITS_PER_BLOCK
);
1170 rtree
+= DIV_ROUND_UP(rtree
* sizeof(struct rtree_node
),
1171 LINKED_PAGE_DATA_SIZE
);
1173 nodes
= DIV_ROUND_UP(nodes
, BM_ENTRIES_PER_LEVEL
);
1180 #ifdef CONFIG_HIGHMEM
1182 * count_free_highmem_pages - Compute the total number of free highmem pages.
1184 * The returned number is system-wide.
1186 static unsigned int count_free_highmem_pages(void)
1189 unsigned int cnt
= 0;
1191 for_each_populated_zone(zone
)
1192 if (is_highmem(zone
))
1193 cnt
+= zone_page_state(zone
, NR_FREE_PAGES
);
1199 * saveable_highmem_page - Check if a highmem page is saveable.
1201 * Determine whether a highmem page should be included in a hibernation image.
1203 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1204 * and it isn't part of a free chunk of pages.
1206 static struct page
*saveable_highmem_page(struct zone
*zone
, unsigned long pfn
)
1210 if (!pfn_valid(pfn
))
1213 page
= pfn_to_page(pfn
);
1214 if (page_zone(page
) != zone
)
1217 BUG_ON(!PageHighMem(page
));
1219 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
) ||
1223 if (page_is_guard(page
))
1230 * count_highmem_pages - Compute the total number of saveable highmem pages.
1232 static unsigned int count_highmem_pages(void)
1237 for_each_populated_zone(zone
) {
1238 unsigned long pfn
, max_zone_pfn
;
1240 if (!is_highmem(zone
))
1243 mark_free_pages(zone
);
1244 max_zone_pfn
= zone_end_pfn(zone
);
1245 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1246 if (saveable_highmem_page(zone
, pfn
))
1252 static inline void *saveable_highmem_page(struct zone
*z
, unsigned long p
)
1256 #endif /* CONFIG_HIGHMEM */
1259 * saveable_page - Check if the given page is saveable.
1261 * Determine whether a non-highmem page should be included in a hibernation
1264 * We should save the page if it isn't Nosave, and is not in the range
1265 * of pages statically defined as 'unsaveable', and it isn't part of
1266 * a free chunk of pages.
1268 static struct page
*saveable_page(struct zone
*zone
, unsigned long pfn
)
1272 if (!pfn_valid(pfn
))
1275 page
= pfn_to_page(pfn
);
1276 if (page_zone(page
) != zone
)
1279 BUG_ON(PageHighMem(page
));
1281 if (swsusp_page_is_forbidden(page
) || swsusp_page_is_free(page
))
1284 if (PageReserved(page
)
1285 && (!kernel_page_present(page
) || pfn_is_nosave(pfn
)))
1288 if (page_is_guard(page
))
1295 * count_data_pages - Compute the total number of saveable non-highmem pages.
1297 static unsigned int count_data_pages(void)
1300 unsigned long pfn
, max_zone_pfn
;
1303 for_each_populated_zone(zone
) {
1304 if (is_highmem(zone
))
1307 mark_free_pages(zone
);
1308 max_zone_pfn
= zone_end_pfn(zone
);
1309 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1310 if (saveable_page(zone
, pfn
))
1317 * This is needed, because copy_page and memcpy are not usable for copying
1320 static inline void do_copy_page(long *dst
, long *src
)
1324 for (n
= PAGE_SIZE
/ sizeof(long); n
; n
--)
1329 * safe_copy_page - Copy a page in a safe way.
1331 * Check if the page we are going to copy is marked as present in the kernel
1332 * page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set
1333 * and in that case kernel_page_present() always returns 'true').
1335 static void safe_copy_page(void *dst
, struct page
*s_page
)
1337 if (kernel_page_present(s_page
)) {
1338 do_copy_page(dst
, page_address(s_page
));
1340 kernel_map_pages(s_page
, 1, 1);
1341 do_copy_page(dst
, page_address(s_page
));
1342 kernel_map_pages(s_page
, 1, 0);
1346 #ifdef CONFIG_HIGHMEM
1347 static inline struct page
*page_is_saveable(struct zone
*zone
, unsigned long pfn
)
1349 return is_highmem(zone
) ?
1350 saveable_highmem_page(zone
, pfn
) : saveable_page(zone
, pfn
);
1353 static void copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
1355 struct page
*s_page
, *d_page
;
1358 s_page
= pfn_to_page(src_pfn
);
1359 d_page
= pfn_to_page(dst_pfn
);
1360 if (PageHighMem(s_page
)) {
1361 src
= kmap_atomic(s_page
);
1362 dst
= kmap_atomic(d_page
);
1363 do_copy_page(dst
, src
);
1367 if (PageHighMem(d_page
)) {
1369 * The page pointed to by src may contain some kernel
1370 * data modified by kmap_atomic()
1372 safe_copy_page(buffer
, s_page
);
1373 dst
= kmap_atomic(d_page
);
1374 copy_page(dst
, buffer
);
1377 safe_copy_page(page_address(d_page
), s_page
);
1382 #define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1384 static inline void copy_data_page(unsigned long dst_pfn
, unsigned long src_pfn
)
1386 safe_copy_page(page_address(pfn_to_page(dst_pfn
)),
1387 pfn_to_page(src_pfn
));
1389 #endif /* CONFIG_HIGHMEM */
1391 static void copy_data_pages(struct memory_bitmap
*copy_bm
,
1392 struct memory_bitmap
*orig_bm
)
1397 for_each_populated_zone(zone
) {
1398 unsigned long max_zone_pfn
;
1400 mark_free_pages(zone
);
1401 max_zone_pfn
= zone_end_pfn(zone
);
1402 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1403 if (page_is_saveable(zone
, pfn
))
1404 memory_bm_set_bit(orig_bm
, pfn
);
1406 memory_bm_position_reset(orig_bm
);
1407 memory_bm_position_reset(copy_bm
);
1409 pfn
= memory_bm_next_pfn(orig_bm
);
1410 if (unlikely(pfn
== BM_END_OF_MAP
))
1412 copy_data_page(memory_bm_next_pfn(copy_bm
), pfn
);
1416 /* Total number of image pages */
1417 static unsigned int nr_copy_pages
;
1418 /* Number of pages needed for saving the original pfns of the image pages */
1419 static unsigned int nr_meta_pages
;
1421 * Numbers of normal and highmem page frames allocated for hibernation image
1422 * before suspending devices.
1424 unsigned int alloc_normal
, alloc_highmem
;
1426 * Memory bitmap used for marking saveable pages (during hibernation) or
1427 * hibernation image pages (during restore)
1429 static struct memory_bitmap orig_bm
;
1431 * Memory bitmap used during hibernation for marking allocated page frames that
1432 * will contain copies of saveable pages. During restore it is initially used
1433 * for marking hibernation image pages, but then the set bits from it are
1434 * duplicated in @orig_bm and it is released. On highmem systems it is next
1435 * used for marking "safe" highmem pages, but it has to be reinitialized for
1438 static struct memory_bitmap copy_bm
;
1441 * swsusp_free - Free pages allocated for hibernation image.
1443 * Image pages are alocated before snapshot creation, so they need to be
1444 * released after resume.
1446 void swsusp_free(void)
1448 unsigned long fb_pfn
, fr_pfn
;
1450 if (!forbidden_pages_map
|| !free_pages_map
)
1453 memory_bm_position_reset(forbidden_pages_map
);
1454 memory_bm_position_reset(free_pages_map
);
1457 fr_pfn
= memory_bm_next_pfn(free_pages_map
);
1458 fb_pfn
= memory_bm_next_pfn(forbidden_pages_map
);
1461 * Find the next bit set in both bitmaps. This is guaranteed to
1462 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1465 if (fb_pfn
< fr_pfn
)
1466 fb_pfn
= memory_bm_next_pfn(forbidden_pages_map
);
1467 if (fr_pfn
< fb_pfn
)
1468 fr_pfn
= memory_bm_next_pfn(free_pages_map
);
1469 } while (fb_pfn
!= fr_pfn
);
1471 if (fr_pfn
!= BM_END_OF_MAP
&& pfn_valid(fr_pfn
)) {
1472 struct page
*page
= pfn_to_page(fr_pfn
);
1474 memory_bm_clear_current(forbidden_pages_map
);
1475 memory_bm_clear_current(free_pages_map
);
1476 hibernate_restore_unprotect_page(page_address(page
));
1484 restore_pblist
= NULL
;
1488 hibernate_restore_protection_end();
1491 /* Helper functions used for the shrinking of memory. */
1493 #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1496 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1497 * @nr_pages: Number of page frames to allocate.
1498 * @mask: GFP flags to use for the allocation.
1500 * Return value: Number of page frames actually allocated
1502 static unsigned long preallocate_image_pages(unsigned long nr_pages
, gfp_t mask
)
1504 unsigned long nr_alloc
= 0;
1506 while (nr_pages
> 0) {
1509 page
= alloc_image_page(mask
);
1512 memory_bm_set_bit(©_bm
, page_to_pfn(page
));
1513 if (PageHighMem(page
))
1524 static unsigned long preallocate_image_memory(unsigned long nr_pages
,
1525 unsigned long avail_normal
)
1527 unsigned long alloc
;
1529 if (avail_normal
<= alloc_normal
)
1532 alloc
= avail_normal
- alloc_normal
;
1533 if (nr_pages
< alloc
)
1536 return preallocate_image_pages(alloc
, GFP_IMAGE
);
1539 #ifdef CONFIG_HIGHMEM
1540 static unsigned long preallocate_image_highmem(unsigned long nr_pages
)
1542 return preallocate_image_pages(nr_pages
, GFP_IMAGE
| __GFP_HIGHMEM
);
1546 * __fraction - Compute (an approximation of) x * (multiplier / base).
1548 static unsigned long __fraction(u64 x
, u64 multiplier
, u64 base
)
1552 return (unsigned long)x
;
1555 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages
,
1556 unsigned long highmem
,
1557 unsigned long total
)
1559 unsigned long alloc
= __fraction(nr_pages
, highmem
, total
);
1561 return preallocate_image_pages(alloc
, GFP_IMAGE
| __GFP_HIGHMEM
);
1563 #else /* CONFIG_HIGHMEM */
1564 static inline unsigned long preallocate_image_highmem(unsigned long nr_pages
)
1569 static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages
,
1570 unsigned long highmem
,
1571 unsigned long total
)
1575 #endif /* CONFIG_HIGHMEM */
1578 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1580 static unsigned long free_unnecessary_pages(void)
1582 unsigned long save
, to_free_normal
, to_free_highmem
, free
;
1584 save
= count_data_pages();
1585 if (alloc_normal
>= save
) {
1586 to_free_normal
= alloc_normal
- save
;
1590 save
-= alloc_normal
;
1592 save
+= count_highmem_pages();
1593 if (alloc_highmem
>= save
) {
1594 to_free_highmem
= alloc_highmem
- save
;
1596 to_free_highmem
= 0;
1597 save
-= alloc_highmem
;
1598 if (to_free_normal
> save
)
1599 to_free_normal
-= save
;
1603 free
= to_free_normal
+ to_free_highmem
;
1605 memory_bm_position_reset(©_bm
);
1607 while (to_free_normal
> 0 || to_free_highmem
> 0) {
1608 unsigned long pfn
= memory_bm_next_pfn(©_bm
);
1609 struct page
*page
= pfn_to_page(pfn
);
1611 if (PageHighMem(page
)) {
1612 if (!to_free_highmem
)
1617 if (!to_free_normal
)
1622 memory_bm_clear_bit(©_bm
, pfn
);
1623 swsusp_unset_page_forbidden(page
);
1624 swsusp_unset_page_free(page
);
1632 * minimum_image_size - Estimate the minimum acceptable size of an image.
1633 * @saveable: Number of saveable pages in the system.
1635 * We want to avoid attempting to free too much memory too hard, so estimate the
1636 * minimum acceptable size of a hibernation image to use as the lower limit for
1637 * preallocating memory.
1639 * We assume that the minimum image size should be proportional to
1641 * [number of saveable pages] - [number of pages that can be freed in theory]
1643 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1644 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages,
1645 * minus mapped file pages.
1647 static unsigned long minimum_image_size(unsigned long saveable
)
1651 size
= global_page_state(NR_SLAB_RECLAIMABLE
)
1652 + global_node_page_state(NR_ACTIVE_ANON
)
1653 + global_node_page_state(NR_INACTIVE_ANON
)
1654 + global_node_page_state(NR_ACTIVE_FILE
)
1655 + global_node_page_state(NR_INACTIVE_FILE
)
1656 - global_node_page_state(NR_FILE_MAPPED
);
1658 return saveable
<= size
? 0 : saveable
- size
;
1662 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1664 * To create a hibernation image it is necessary to make a copy of every page
1665 * frame in use. We also need a number of page frames to be free during
1666 * hibernation for allocations made while saving the image and for device
1667 * drivers, in case they need to allocate memory from their hibernation
1668 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1669 * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
1670 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1671 * total number of available page frames and allocate at least
1673 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1674 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1676 * of them, which corresponds to the maximum size of a hibernation image.
1678 * If image_size is set below the number following from the above formula,
1679 * the preallocation of memory is continued until the total number of saveable
1680 * pages in the system is below the requested image size or the minimum
1681 * acceptable image size returned by minimum_image_size(), whichever is greater.
1683 int hibernate_preallocate_memory(void)
1686 unsigned long saveable
, size
, max_size
, count
, highmem
, pages
= 0;
1687 unsigned long alloc
, save_highmem
, pages_highmem
, avail_normal
;
1688 ktime_t start
, stop
;
1691 printk(KERN_INFO
"PM: Preallocating image memory... ");
1692 start
= ktime_get();
1694 error
= memory_bm_create(&orig_bm
, GFP_IMAGE
, PG_ANY
);
1698 error
= memory_bm_create(©_bm
, GFP_IMAGE
, PG_ANY
);
1705 /* Count the number of saveable data pages. */
1706 save_highmem
= count_highmem_pages();
1707 saveable
= count_data_pages();
1710 * Compute the total number of page frames we can use (count) and the
1711 * number of pages needed for image metadata (size).
1714 saveable
+= save_highmem
;
1715 highmem
= save_highmem
;
1717 for_each_populated_zone(zone
) {
1718 size
+= snapshot_additional_pages(zone
);
1719 if (is_highmem(zone
))
1720 highmem
+= zone_page_state(zone
, NR_FREE_PAGES
);
1722 count
+= zone_page_state(zone
, NR_FREE_PAGES
);
1724 avail_normal
= count
;
1726 count
-= totalreserve_pages
;
1728 /* Add number of pages required for page keys (s390 only). */
1729 size
+= page_key_additional_pages(saveable
);
1731 /* Compute the maximum number of saveable pages to leave in memory. */
1732 max_size
= (count
- (size
+ PAGES_FOR_IO
)) / 2
1733 - 2 * DIV_ROUND_UP(reserved_size
, PAGE_SIZE
);
1734 /* Compute the desired number of image pages specified by image_size. */
1735 size
= DIV_ROUND_UP(image_size
, PAGE_SIZE
);
1736 if (size
> max_size
)
1739 * If the desired number of image pages is at least as large as the
1740 * current number of saveable pages in memory, allocate page frames for
1741 * the image and we're done.
1743 if (size
>= saveable
) {
1744 pages
= preallocate_image_highmem(save_highmem
);
1745 pages
+= preallocate_image_memory(saveable
- pages
, avail_normal
);
1749 /* Estimate the minimum size of the image. */
1750 pages
= minimum_image_size(saveable
);
1752 * To avoid excessive pressure on the normal zone, leave room in it to
1753 * accommodate an image of the minimum size (unless it's already too
1754 * small, in which case don't preallocate pages from it at all).
1756 if (avail_normal
> pages
)
1757 avail_normal
-= pages
;
1761 size
= min_t(unsigned long, pages
, max_size
);
1764 * Let the memory management subsystem know that we're going to need a
1765 * large number of page frames to allocate and make it free some memory.
1766 * NOTE: If this is not done, performance will be hurt badly in some
1769 shrink_all_memory(saveable
- size
);
1772 * The number of saveable pages in memory was too high, so apply some
1773 * pressure to decrease it. First, make room for the largest possible
1774 * image and fail if that doesn't work. Next, try to decrease the size
1775 * of the image as much as indicated by 'size' using allocations from
1776 * highmem and non-highmem zones separately.
1778 pages_highmem
= preallocate_image_highmem(highmem
/ 2);
1779 alloc
= count
- max_size
;
1780 if (alloc
> pages_highmem
)
1781 alloc
-= pages_highmem
;
1784 pages
= preallocate_image_memory(alloc
, avail_normal
);
1785 if (pages
< alloc
) {
1786 /* We have exhausted non-highmem pages, try highmem. */
1788 pages
+= pages_highmem
;
1789 pages_highmem
= preallocate_image_highmem(alloc
);
1790 if (pages_highmem
< alloc
)
1792 pages
+= pages_highmem
;
1794 * size is the desired number of saveable pages to leave in
1795 * memory, so try to preallocate (all memory - size) pages.
1797 alloc
= (count
- pages
) - size
;
1798 pages
+= preallocate_image_highmem(alloc
);
1801 * There are approximately max_size saveable pages at this point
1802 * and we want to reduce this number down to size.
1804 alloc
= max_size
- size
;
1805 size
= preallocate_highmem_fraction(alloc
, highmem
, count
);
1806 pages_highmem
+= size
;
1808 size
= preallocate_image_memory(alloc
, avail_normal
);
1809 pages_highmem
+= preallocate_image_highmem(alloc
- size
);
1810 pages
+= pages_highmem
+ size
;
1814 * We only need as many page frames for the image as there are saveable
1815 * pages in memory, but we have allocated more. Release the excessive
1818 pages
-= free_unnecessary_pages();
1822 printk(KERN_CONT
"done (allocated %lu pages)\n", pages
);
1823 swsusp_show_speed(start
, stop
, pages
, "Allocated");
1828 printk(KERN_CONT
"\n");
1833 #ifdef CONFIG_HIGHMEM
1835 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1837 * Compute the number of non-highmem pages that will be necessary for creating
1838 * copies of highmem pages.
1840 static unsigned int count_pages_for_highmem(unsigned int nr_highmem
)
1842 unsigned int free_highmem
= count_free_highmem_pages() + alloc_highmem
;
1844 if (free_highmem
>= nr_highmem
)
1847 nr_highmem
-= free_highmem
;
1852 static unsigned int count_pages_for_highmem(unsigned int nr_highmem
) { return 0; }
1853 #endif /* CONFIG_HIGHMEM */
1856 * enough_free_mem - Check if there is enough free memory for the image.
1858 static int enough_free_mem(unsigned int nr_pages
, unsigned int nr_highmem
)
1861 unsigned int free
= alloc_normal
;
1863 for_each_populated_zone(zone
)
1864 if (!is_highmem(zone
))
1865 free
+= zone_page_state(zone
, NR_FREE_PAGES
);
1867 nr_pages
+= count_pages_for_highmem(nr_highmem
);
1868 pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n",
1869 nr_pages
, PAGES_FOR_IO
, free
);
1871 return free
> nr_pages
+ PAGES_FOR_IO
;
1874 #ifdef CONFIG_HIGHMEM
1876 * get_highmem_buffer - Allocate a buffer for highmem pages.
1878 * If there are some highmem pages in the hibernation image, we may need a
1879 * buffer to copy them and/or load their data.
1881 static inline int get_highmem_buffer(int safe_needed
)
1883 buffer
= get_image_page(GFP_ATOMIC
| __GFP_COLD
, safe_needed
);
1884 return buffer
? 0 : -ENOMEM
;
1888 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1890 * Try to allocate as many pages as needed, but if the number of free highmem
1891 * pages is less than that, allocate them all.
1893 static inline unsigned int alloc_highmem_pages(struct memory_bitmap
*bm
,
1894 unsigned int nr_highmem
)
1896 unsigned int to_alloc
= count_free_highmem_pages();
1898 if (to_alloc
> nr_highmem
)
1899 to_alloc
= nr_highmem
;
1901 nr_highmem
-= to_alloc
;
1902 while (to_alloc
-- > 0) {
1905 page
= alloc_image_page(__GFP_HIGHMEM
|__GFP_KSWAPD_RECLAIM
);
1906 memory_bm_set_bit(bm
, page_to_pfn(page
));
1911 static inline int get_highmem_buffer(int safe_needed
) { return 0; }
1913 static inline unsigned int alloc_highmem_pages(struct memory_bitmap
*bm
,
1914 unsigned int n
) { return 0; }
1915 #endif /* CONFIG_HIGHMEM */
1918 * swsusp_alloc - Allocate memory for hibernation image.
1920 * We first try to allocate as many highmem pages as there are
1921 * saveable highmem pages in the system. If that fails, we allocate
1922 * non-highmem pages for the copies of the remaining highmem ones.
1924 * In this approach it is likely that the copies of highmem pages will
1925 * also be located in the high memory, because of the way in which
1926 * copy_data_pages() works.
1928 static int swsusp_alloc(struct memory_bitmap
*orig_bm
,
1929 struct memory_bitmap
*copy_bm
,
1930 unsigned int nr_pages
, unsigned int nr_highmem
)
1932 if (nr_highmem
> 0) {
1933 if (get_highmem_buffer(PG_ANY
))
1935 if (nr_highmem
> alloc_highmem
) {
1936 nr_highmem
-= alloc_highmem
;
1937 nr_pages
+= alloc_highmem_pages(copy_bm
, nr_highmem
);
1940 if (nr_pages
> alloc_normal
) {
1941 nr_pages
-= alloc_normal
;
1942 while (nr_pages
-- > 0) {
1945 page
= alloc_image_page(GFP_ATOMIC
| __GFP_COLD
);
1948 memory_bm_set_bit(copy_bm
, page_to_pfn(page
));
1959 asmlinkage __visible
int swsusp_save(void)
1961 unsigned int nr_pages
, nr_highmem
;
1963 printk(KERN_INFO
"PM: Creating hibernation image:\n");
1965 drain_local_pages(NULL
);
1966 nr_pages
= count_data_pages();
1967 nr_highmem
= count_highmem_pages();
1968 printk(KERN_INFO
"PM: Need to copy %u pages\n", nr_pages
+ nr_highmem
);
1970 if (!enough_free_mem(nr_pages
, nr_highmem
)) {
1971 printk(KERN_ERR
"PM: Not enough free memory\n");
1975 if (swsusp_alloc(&orig_bm
, ©_bm
, nr_pages
, nr_highmem
)) {
1976 printk(KERN_ERR
"PM: Memory allocation failed\n");
1981 * During allocating of suspend pagedir, new cold pages may appear.
1984 drain_local_pages(NULL
);
1985 copy_data_pages(©_bm
, &orig_bm
);
1988 * End of critical section. From now on, we can write to memory,
1989 * but we should not touch disk. This specially means we must _not_
1990 * touch swap space! Except we must write out our image of course.
1993 nr_pages
+= nr_highmem
;
1994 nr_copy_pages
= nr_pages
;
1995 nr_meta_pages
= DIV_ROUND_UP(nr_pages
* sizeof(long), PAGE_SIZE
);
1997 printk(KERN_INFO
"PM: Hibernation image created (%d pages copied)\n",
2003 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
2004 static int init_header_complete(struct swsusp_info
*info
)
2006 memcpy(&info
->uts
, init_utsname(), sizeof(struct new_utsname
));
2007 info
->version_code
= LINUX_VERSION_CODE
;
2011 static char *check_image_kernel(struct swsusp_info
*info
)
2013 if (info
->version_code
!= LINUX_VERSION_CODE
)
2014 return "kernel version";
2015 if (strcmp(info
->uts
.sysname
,init_utsname()->sysname
))
2016 return "system type";
2017 if (strcmp(info
->uts
.release
,init_utsname()->release
))
2018 return "kernel release";
2019 if (strcmp(info
->uts
.version
,init_utsname()->version
))
2021 if (strcmp(info
->uts
.machine
,init_utsname()->machine
))
2025 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2027 unsigned long snapshot_get_image_size(void)
2029 return nr_copy_pages
+ nr_meta_pages
+ 1;
2032 static int init_header(struct swsusp_info
*info
)
2034 memset(info
, 0, sizeof(struct swsusp_info
));
2035 info
->num_physpages
= get_num_physpages();
2036 info
->image_pages
= nr_copy_pages
;
2037 info
->pages
= snapshot_get_image_size();
2038 info
->size
= info
->pages
;
2039 info
->size
<<= PAGE_SHIFT
;
2040 return init_header_complete(info
);
2044 * pack_pfns - Prepare PFNs for saving.
2045 * @bm: Memory bitmap.
2046 * @buf: Memory buffer to store the PFNs in.
2048 * PFNs corresponding to set bits in @bm are stored in the area of memory
2049 * pointed to by @buf (1 page at a time).
2051 static inline void pack_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
2055 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
2056 buf
[j
] = memory_bm_next_pfn(bm
);
2057 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
2059 /* Save page key for data page (s390 only). */
2060 page_key_read(buf
+ j
);
2065 * snapshot_read_next - Get the address to read the next image page from.
2066 * @handle: Snapshot handle to be used for the reading.
2068 * On the first call, @handle should point to a zeroed snapshot_handle
2069 * structure. The structure gets populated then and a pointer to it should be
2070 * passed to this function every next time.
2072 * On success, the function returns a positive number. Then, the caller
2073 * is allowed to read up to the returned number of bytes from the memory
2074 * location computed by the data_of() macro.
2076 * The function returns 0 to indicate the end of the data stream condition,
2077 * and negative numbers are returned on errors. If that happens, the structure
2078 * pointed to by @handle is not updated and should not be used any more.
2080 int snapshot_read_next(struct snapshot_handle
*handle
)
2082 if (handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
2086 /* This makes the buffer be freed by swsusp_free() */
2087 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
2094 error
= init_header((struct swsusp_info
*)buffer
);
2097 handle
->buffer
= buffer
;
2098 memory_bm_position_reset(&orig_bm
);
2099 memory_bm_position_reset(©_bm
);
2100 } else if (handle
->cur
<= nr_meta_pages
) {
2102 pack_pfns(buffer
, &orig_bm
);
2106 page
= pfn_to_page(memory_bm_next_pfn(©_bm
));
2107 if (PageHighMem(page
)) {
2109 * Highmem pages are copied to the buffer,
2110 * because we can't return with a kmapped
2111 * highmem page (we may not be called again).
2115 kaddr
= kmap_atomic(page
);
2116 copy_page(buffer
, kaddr
);
2117 kunmap_atomic(kaddr
);
2118 handle
->buffer
= buffer
;
2120 handle
->buffer
= page_address(page
);
2127 static void duplicate_memory_bitmap(struct memory_bitmap
*dst
,
2128 struct memory_bitmap
*src
)
2132 memory_bm_position_reset(src
);
2133 pfn
= memory_bm_next_pfn(src
);
2134 while (pfn
!= BM_END_OF_MAP
) {
2135 memory_bm_set_bit(dst
, pfn
);
2136 pfn
= memory_bm_next_pfn(src
);
2141 * mark_unsafe_pages - Mark pages that were used before hibernation.
2143 * Mark the pages that cannot be used for storing the image during restoration,
2144 * because they conflict with the pages that had been used before hibernation.
2146 static void mark_unsafe_pages(struct memory_bitmap
*bm
)
2150 /* Clear the "free"/"unsafe" bit for all PFNs */
2151 memory_bm_position_reset(free_pages_map
);
2152 pfn
= memory_bm_next_pfn(free_pages_map
);
2153 while (pfn
!= BM_END_OF_MAP
) {
2154 memory_bm_clear_current(free_pages_map
);
2155 pfn
= memory_bm_next_pfn(free_pages_map
);
2158 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2159 duplicate_memory_bitmap(free_pages_map
, bm
);
2161 allocated_unsafe_pages
= 0;
2164 static int check_header(struct swsusp_info
*info
)
2168 reason
= check_image_kernel(info
);
2169 if (!reason
&& info
->num_physpages
!= get_num_physpages())
2170 reason
= "memory size";
2172 printk(KERN_ERR
"PM: Image mismatch: %s\n", reason
);
2179 * load header - Check the image header and copy the data from it.
2181 static int load_header(struct swsusp_info
*info
)
2185 restore_pblist
= NULL
;
2186 error
= check_header(info
);
2188 nr_copy_pages
= info
->image_pages
;
2189 nr_meta_pages
= info
->pages
- info
->image_pages
- 1;
2195 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2196 * @bm: Memory bitmap.
2197 * @buf: Area of memory containing the PFNs.
2199 * For each element of the array pointed to by @buf (1 page at a time), set the
2200 * corresponding bit in @bm.
2202 static int unpack_orig_pfns(unsigned long *buf
, struct memory_bitmap
*bm
)
2206 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long); j
++) {
2207 if (unlikely(buf
[j
] == BM_END_OF_MAP
))
2210 /* Extract and buffer page key for data page (s390 only). */
2211 page_key_memorize(buf
+ j
);
2213 if (pfn_valid(buf
[j
]) && memory_bm_pfn_present(bm
, buf
[j
]))
2214 memory_bm_set_bit(bm
, buf
[j
]);
2222 #ifdef CONFIG_HIGHMEM
2224 * struct highmem_pbe is used for creating the list of highmem pages that
2225 * should be restored atomically during the resume from disk, because the page
2226 * frames they have occupied before the suspend are in use.
2228 struct highmem_pbe
{
2229 struct page
*copy_page
; /* data is here now */
2230 struct page
*orig_page
; /* data was here before the suspend */
2231 struct highmem_pbe
*next
;
2235 * List of highmem PBEs needed for restoring the highmem pages that were
2236 * allocated before the suspend and included in the suspend image, but have
2237 * also been allocated by the "resume" kernel, so their contents cannot be
2238 * written directly to their "original" page frames.
2240 static struct highmem_pbe
*highmem_pblist
;
2243 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2244 * @bm: Memory bitmap.
2246 * The bits in @bm that correspond to image pages are assumed to be set.
2248 static unsigned int count_highmem_image_pages(struct memory_bitmap
*bm
)
2251 unsigned int cnt
= 0;
2253 memory_bm_position_reset(bm
);
2254 pfn
= memory_bm_next_pfn(bm
);
2255 while (pfn
!= BM_END_OF_MAP
) {
2256 if (PageHighMem(pfn_to_page(pfn
)))
2259 pfn
= memory_bm_next_pfn(bm
);
2264 static unsigned int safe_highmem_pages
;
2266 static struct memory_bitmap
*safe_highmem_bm
;
2269 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2270 * @bm: Pointer to an uninitialized memory bitmap structure.
2271 * @nr_highmem_p: Pointer to the number of highmem image pages.
2273 * Try to allocate as many highmem pages as there are highmem image pages
2274 * (@nr_highmem_p points to the variable containing the number of highmem image
2275 * pages). The pages that are "safe" (ie. will not be overwritten when the
2276 * hibernation image is restored entirely) have the corresponding bits set in
2277 * @bm (it must be unitialized).
2279 * NOTE: This function should not be called if there are no highmem image pages.
2281 static int prepare_highmem_image(struct memory_bitmap
*bm
,
2282 unsigned int *nr_highmem_p
)
2284 unsigned int to_alloc
;
2286 if (memory_bm_create(bm
, GFP_ATOMIC
, PG_SAFE
))
2289 if (get_highmem_buffer(PG_SAFE
))
2292 to_alloc
= count_free_highmem_pages();
2293 if (to_alloc
> *nr_highmem_p
)
2294 to_alloc
= *nr_highmem_p
;
2296 *nr_highmem_p
= to_alloc
;
2298 safe_highmem_pages
= 0;
2299 while (to_alloc
-- > 0) {
2302 page
= alloc_page(__GFP_HIGHMEM
);
2303 if (!swsusp_page_is_free(page
)) {
2304 /* The page is "safe", set its bit the bitmap */
2305 memory_bm_set_bit(bm
, page_to_pfn(page
));
2306 safe_highmem_pages
++;
2308 /* Mark the page as allocated */
2309 swsusp_set_page_forbidden(page
);
2310 swsusp_set_page_free(page
);
2312 memory_bm_position_reset(bm
);
2313 safe_highmem_bm
= bm
;
2317 static struct page
*last_highmem_page
;
2320 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2322 * For a given highmem image page get a buffer that suspend_write_next() should
2323 * return to its caller to write to.
2325 * If the page is to be saved to its "original" page frame or a copy of
2326 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2327 * the copy of the page is to be made in normal memory, so the address of
2328 * the copy is returned.
2330 * If @buffer is returned, the caller of suspend_write_next() will write
2331 * the page's contents to @buffer, so they will have to be copied to the
2332 * right location on the next call to suspend_write_next() and it is done
2333 * with the help of copy_last_highmem_page(). For this purpose, if
2334 * @buffer is returned, @last_highmem_page is set to the page to which
2335 * the data will have to be copied from @buffer.
2337 static void *get_highmem_page_buffer(struct page
*page
,
2338 struct chain_allocator
*ca
)
2340 struct highmem_pbe
*pbe
;
2343 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
)) {
2345 * We have allocated the "original" page frame and we can
2346 * use it directly to store the loaded page.
2348 last_highmem_page
= page
;
2352 * The "original" page frame has not been allocated and we have to
2353 * use a "safe" page frame to store the loaded page.
2355 pbe
= chain_alloc(ca
, sizeof(struct highmem_pbe
));
2358 return ERR_PTR(-ENOMEM
);
2360 pbe
->orig_page
= page
;
2361 if (safe_highmem_pages
> 0) {
2364 /* Copy of the page will be stored in high memory */
2366 tmp
= pfn_to_page(memory_bm_next_pfn(safe_highmem_bm
));
2367 safe_highmem_pages
--;
2368 last_highmem_page
= tmp
;
2369 pbe
->copy_page
= tmp
;
2371 /* Copy of the page will be stored in normal memory */
2372 kaddr
= safe_pages_list
;
2373 safe_pages_list
= safe_pages_list
->next
;
2374 pbe
->copy_page
= virt_to_page(kaddr
);
2376 pbe
->next
= highmem_pblist
;
2377 highmem_pblist
= pbe
;
2382 * copy_last_highmem_page - Copy most the most recent highmem image page.
2384 * Copy the contents of a highmem image from @buffer, where the caller of
2385 * snapshot_write_next() has stored them, to the right location represented by
2386 * @last_highmem_page .
2388 static void copy_last_highmem_page(void)
2390 if (last_highmem_page
) {
2393 dst
= kmap_atomic(last_highmem_page
);
2394 copy_page(dst
, buffer
);
2396 last_highmem_page
= NULL
;
2400 static inline int last_highmem_page_copied(void)
2402 return !last_highmem_page
;
2405 static inline void free_highmem_data(void)
2407 if (safe_highmem_bm
)
2408 memory_bm_free(safe_highmem_bm
, PG_UNSAFE_CLEAR
);
2411 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
2414 static unsigned int count_highmem_image_pages(struct memory_bitmap
*bm
) { return 0; }
2416 static inline int prepare_highmem_image(struct memory_bitmap
*bm
,
2417 unsigned int *nr_highmem_p
) { return 0; }
2419 static inline void *get_highmem_page_buffer(struct page
*page
,
2420 struct chain_allocator
*ca
)
2422 return ERR_PTR(-EINVAL
);
2425 static inline void copy_last_highmem_page(void) {}
2426 static inline int last_highmem_page_copied(void) { return 1; }
2427 static inline void free_highmem_data(void) {}
2428 #endif /* CONFIG_HIGHMEM */
2430 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2433 * prepare_image - Make room for loading hibernation image.
2434 * @new_bm: Unitialized memory bitmap structure.
2435 * @bm: Memory bitmap with unsafe pages marked.
2437 * Use @bm to mark the pages that will be overwritten in the process of
2438 * restoring the system memory state from the suspend image ("unsafe" pages)
2439 * and allocate memory for the image.
2441 * The idea is to allocate a new memory bitmap first and then allocate
2442 * as many pages as needed for image data, but without specifying what those
2443 * pages will be used for just yet. Instead, we mark them all as allocated and
2444 * create a lists of "safe" pages to be used later. On systems with high
2445 * memory a list of "safe" highmem pages is created too.
2447 static int prepare_image(struct memory_bitmap
*new_bm
, struct memory_bitmap
*bm
)
2449 unsigned int nr_pages
, nr_highmem
;
2450 struct linked_page
*lp
;
2453 /* If there is no highmem, the buffer will not be necessary */
2454 free_image_page(buffer
, PG_UNSAFE_CLEAR
);
2457 nr_highmem
= count_highmem_image_pages(bm
);
2458 mark_unsafe_pages(bm
);
2460 error
= memory_bm_create(new_bm
, GFP_ATOMIC
, PG_SAFE
);
2464 duplicate_memory_bitmap(new_bm
, bm
);
2465 memory_bm_free(bm
, PG_UNSAFE_KEEP
);
2466 if (nr_highmem
> 0) {
2467 error
= prepare_highmem_image(bm
, &nr_highmem
);
2472 * Reserve some safe pages for potential later use.
2474 * NOTE: This way we make sure there will be enough safe pages for the
2475 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2476 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2478 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2480 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
2481 nr_pages
= DIV_ROUND_UP(nr_pages
, PBES_PER_LINKED_PAGE
);
2482 while (nr_pages
> 0) {
2483 lp
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
2488 lp
->next
= safe_pages_list
;
2489 safe_pages_list
= lp
;
2492 /* Preallocate memory for the image */
2493 nr_pages
= nr_copy_pages
- nr_highmem
- allocated_unsafe_pages
;
2494 while (nr_pages
> 0) {
2495 lp
= (struct linked_page
*)get_zeroed_page(GFP_ATOMIC
);
2500 if (!swsusp_page_is_free(virt_to_page(lp
))) {
2501 /* The page is "safe", add it to the list */
2502 lp
->next
= safe_pages_list
;
2503 safe_pages_list
= lp
;
2505 /* Mark the page as allocated */
2506 swsusp_set_page_forbidden(virt_to_page(lp
));
2507 swsusp_set_page_free(virt_to_page(lp
));
2518 * get_buffer - Get the address to store the next image data page.
2520 * Get the address that snapshot_write_next() should return to its caller to
2523 static void *get_buffer(struct memory_bitmap
*bm
, struct chain_allocator
*ca
)
2527 unsigned long pfn
= memory_bm_next_pfn(bm
);
2529 if (pfn
== BM_END_OF_MAP
)
2530 return ERR_PTR(-EFAULT
);
2532 page
= pfn_to_page(pfn
);
2533 if (PageHighMem(page
))
2534 return get_highmem_page_buffer(page
, ca
);
2536 if (swsusp_page_is_forbidden(page
) && swsusp_page_is_free(page
))
2538 * We have allocated the "original" page frame and we can
2539 * use it directly to store the loaded page.
2541 return page_address(page
);
2544 * The "original" page frame has not been allocated and we have to
2545 * use a "safe" page frame to store the loaded page.
2547 pbe
= chain_alloc(ca
, sizeof(struct pbe
));
2550 return ERR_PTR(-ENOMEM
);
2552 pbe
->orig_address
= page_address(page
);
2553 pbe
->address
= safe_pages_list
;
2554 safe_pages_list
= safe_pages_list
->next
;
2555 pbe
->next
= restore_pblist
;
2556 restore_pblist
= pbe
;
2557 return pbe
->address
;
2561 * snapshot_write_next - Get the address to store the next image page.
2562 * @handle: Snapshot handle structure to guide the writing.
2564 * On the first call, @handle should point to a zeroed snapshot_handle
2565 * structure. The structure gets populated then and a pointer to it should be
2566 * passed to this function every next time.
2568 * On success, the function returns a positive number. Then, the caller
2569 * is allowed to write up to the returned number of bytes to the memory
2570 * location computed by the data_of() macro.
2572 * The function returns 0 to indicate the "end of file" condition. Negative
2573 * numbers are returned on errors, in which cases the structure pointed to by
2574 * @handle is not updated and should not be used any more.
2576 int snapshot_write_next(struct snapshot_handle
*handle
)
2578 static struct chain_allocator ca
;
2581 /* Check if we have already loaded the entire image */
2582 if (handle
->cur
> 1 && handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
2585 handle
->sync_read
= 1;
2589 /* This makes the buffer be freed by swsusp_free() */
2590 buffer
= get_image_page(GFP_ATOMIC
, PG_ANY
);
2595 handle
->buffer
= buffer
;
2596 } else if (handle
->cur
== 1) {
2597 error
= load_header(buffer
);
2601 safe_pages_list
= NULL
;
2603 error
= memory_bm_create(©_bm
, GFP_ATOMIC
, PG_ANY
);
2607 /* Allocate buffer for page keys. */
2608 error
= page_key_alloc(nr_copy_pages
);
2612 hibernate_restore_protection_begin();
2613 } else if (handle
->cur
<= nr_meta_pages
+ 1) {
2614 error
= unpack_orig_pfns(buffer
, ©_bm
);
2618 if (handle
->cur
== nr_meta_pages
+ 1) {
2619 error
= prepare_image(&orig_bm
, ©_bm
);
2623 chain_init(&ca
, GFP_ATOMIC
, PG_SAFE
);
2624 memory_bm_position_reset(&orig_bm
);
2625 restore_pblist
= NULL
;
2626 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
2627 handle
->sync_read
= 0;
2628 if (IS_ERR(handle
->buffer
))
2629 return PTR_ERR(handle
->buffer
);
2632 copy_last_highmem_page();
2633 /* Restore page key for data page (s390 only). */
2634 page_key_write(handle
->buffer
);
2635 hibernate_restore_protect_page(handle
->buffer
);
2636 handle
->buffer
= get_buffer(&orig_bm
, &ca
);
2637 if (IS_ERR(handle
->buffer
))
2638 return PTR_ERR(handle
->buffer
);
2639 if (handle
->buffer
!= buffer
)
2640 handle
->sync_read
= 0;
2647 * snapshot_write_finalize - Complete the loading of a hibernation image.
2649 * Must be called after the last call to snapshot_write_next() in case the last
2650 * page in the image happens to be a highmem page and its contents should be
2651 * stored in highmem. Additionally, it recycles bitmap memory that's not
2652 * necessary any more.
2654 void snapshot_write_finalize(struct snapshot_handle
*handle
)
2656 copy_last_highmem_page();
2657 /* Restore page key for data page (s390 only). */
2658 page_key_write(handle
->buffer
);
2660 hibernate_restore_protect_page(handle
->buffer
);
2661 /* Do that only if we have loaded the image entirely */
2662 if (handle
->cur
> 1 && handle
->cur
> nr_meta_pages
+ nr_copy_pages
) {
2663 memory_bm_recycle(&orig_bm
);
2664 free_highmem_data();
2668 int snapshot_image_loaded(struct snapshot_handle
*handle
)
2670 return !(!nr_copy_pages
|| !last_highmem_page_copied() ||
2671 handle
->cur
<= nr_meta_pages
+ nr_copy_pages
);
2674 #ifdef CONFIG_HIGHMEM
2675 /* Assumes that @buf is ready and points to a "safe" page */
2676 static inline void swap_two_pages_data(struct page
*p1
, struct page
*p2
,
2679 void *kaddr1
, *kaddr2
;
2681 kaddr1
= kmap_atomic(p1
);
2682 kaddr2
= kmap_atomic(p2
);
2683 copy_page(buf
, kaddr1
);
2684 copy_page(kaddr1
, kaddr2
);
2685 copy_page(kaddr2
, buf
);
2686 kunmap_atomic(kaddr2
);
2687 kunmap_atomic(kaddr1
);
2691 * restore_highmem - Put highmem image pages into their original locations.
2693 * For each highmem page that was in use before hibernation and is included in
2694 * the image, and also has been allocated by the "restore" kernel, swap its
2695 * current contents with the previous (ie. "before hibernation") ones.
2697 * If the restore eventually fails, we can call this function once again and
2698 * restore the highmem state as seen by the restore kernel.
2700 int restore_highmem(void)
2702 struct highmem_pbe
*pbe
= highmem_pblist
;
2708 buf
= get_image_page(GFP_ATOMIC
, PG_SAFE
);
2713 swap_two_pages_data(pbe
->copy_page
, pbe
->orig_page
, buf
);
2716 free_image_page(buf
, PG_UNSAFE_CLEAR
);
2719 #endif /* CONFIG_HIGHMEM */