1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/kernel/power/snapshot.c
5 * This file provides system snapshot/restore functionality for swsusp.
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
11 #define pr_fmt(fmt) "PM: hibernation: " fmt
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/memblock.h>
25 #include <linux/nmi.h>
26 #include <linux/syscalls.h>
27 #include <linux/console.h>
28 #include <linux/highmem.h>
29 #include <linux/list.h>
30 #include <linux/slab.h>
31 #include <linux/compiler.h>
32 #include <linux/ktime.h>
33 #include <linux/set_memory.h>
35 #include <linux/uaccess.h>
36 #include <asm/mmu_context.h>
37 #include <asm/tlbflush.h>
42 #if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
43 static bool hibernate_restore_protection;
44 static bool hibernate_restore_protection_active;
46 void enable_restore_image_protection(void)
48 hibernate_restore_protection = true;
51 static inline void hibernate_restore_protection_begin(void)
53 hibernate_restore_protection_active = hibernate_restore_protection;
56 static inline void hibernate_restore_protection_end(void)
58 hibernate_restore_protection_active = false;
61 static inline void hibernate_restore_protect_page(void *page_address)
63 if (hibernate_restore_protection_active)
64 set_memory_ro((unsigned long)page_address, 1);
67 static inline void hibernate_restore_unprotect_page(void *page_address)
69 if (hibernate_restore_protection_active)
70 set_memory_rw((unsigned long)page_address, 1);
73 static inline void hibernate_restore_protection_begin(void) {}
74 static inline void hibernate_restore_protection_end(void) {}
75 static inline void hibernate_restore_protect_page(void *page_address) {}
76 static inline void hibernate_restore_unprotect_page(void *page_address) {}
77 #endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
81 * The calls to set_direct_map_*() should not fail because remapping a page
82 * here means that we only update protection bits in an existing PTE.
83 * It is still worth to have a warning here if something changes and this
84 * will no longer be the case.
86 static inline void hibernate_map_page(struct page *page)
88 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
89 int ret = set_direct_map_default_noflush(page);
92 pr_warn_once("Failed to remap page\n");
94 debug_pagealloc_map_pages(page, 1);
98 static inline void hibernate_unmap_page(struct page *page)
100 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
101 unsigned long addr = (unsigned long)page_address(page);
102 int ret = set_direct_map_invalid_noflush(page);
105 pr_warn_once("Failed to remap page\n");
107 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
109 debug_pagealloc_unmap_pages(page, 1);
113 static int swsusp_page_is_free(struct page *);
114 static void swsusp_set_page_forbidden(struct page *);
115 static void swsusp_unset_page_forbidden(struct page *);
118 * Number of bytes to reserve for memory allocations made by device drivers
119 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
120 * cause image creation to fail (tunable via /sys/power/reserved_size).
122 unsigned long reserved_size;
124 void __init hibernate_reserved_size_init(void)
126 reserved_size = SPARE_PAGES * PAGE_SIZE;
130 * Preferred image size in bytes (tunable via /sys/power/image_size).
131 * When it is set to N, swsusp will do its best to ensure the image
132 * size will not exceed N bytes, but if that is impossible, it will
133 * try to create the smallest image possible.
135 unsigned long image_size;
137 void __init hibernate_image_size_init(void)
139 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
143 * List of PBEs needed for restoring the pages that were allocated before
144 * the suspend and included in the suspend image, but have also been
145 * allocated by the "resume" kernel, so their contents cannot be written
146 * directly to their "original" page frames.
148 struct pbe *restore_pblist;
150 /* struct linked_page is used to build chains of pages */
152 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
155 struct linked_page *next;
156 char data[LINKED_PAGE_DATA_SIZE];
160 * List of "safe" pages (ie. pages that were not used by the image kernel
161 * before hibernation) that may be used as temporary storage for image kernel
164 static struct linked_page *safe_pages_list;
166 /* Pointer to an auxiliary buffer (1 page) */
171 #define PG_UNSAFE_CLEAR 1
172 #define PG_UNSAFE_KEEP 0
174 static unsigned int allocated_unsafe_pages;
177 * get_image_page - Allocate a page for a hibernation image.
178 * @gfp_mask: GFP mask for the allocation.
179 * @safe_needed: Get pages that were not used before hibernation (restore only)
181 * During image restoration, for storing the PBE list and the image data, we can
182 * only use memory pages that do not conflict with the pages used before
183 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
184 * using allocated_unsafe_pages.
186 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
187 * swsusp_free() can release it.
189 static void *get_image_page(gfp_t gfp_mask, int safe_needed)
193 res = (void *)get_zeroed_page(gfp_mask);
195 while (res && swsusp_page_is_free(virt_to_page(res))) {
196 /* The page is unsafe, mark it for swsusp_free() */
197 swsusp_set_page_forbidden(virt_to_page(res));
198 allocated_unsafe_pages++;
199 res = (void *)get_zeroed_page(gfp_mask);
202 swsusp_set_page_forbidden(virt_to_page(res));
203 swsusp_set_page_free(virt_to_page(res));
208 static void *__get_safe_page(gfp_t gfp_mask)
210 if (safe_pages_list) {
211 void *ret = safe_pages_list;
213 safe_pages_list = safe_pages_list->next;
214 memset(ret, 0, PAGE_SIZE);
217 return get_image_page(gfp_mask, PG_SAFE);
220 unsigned long get_safe_page(gfp_t gfp_mask)
222 return (unsigned long)__get_safe_page(gfp_mask);
225 static struct page *alloc_image_page(gfp_t gfp_mask)
229 page = alloc_page(gfp_mask);
231 swsusp_set_page_forbidden(page);
232 swsusp_set_page_free(page);
237 static void recycle_safe_page(void *page_address)
239 struct linked_page *lp = page_address;
241 lp->next = safe_pages_list;
242 safe_pages_list = lp;
246 * free_image_page - Free a page allocated for hibernation image.
247 * @addr: Address of the page to free.
248 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
250 * The page to free should have been allocated by get_image_page() (page flags
251 * set by it are affected).
253 static inline void free_image_page(void *addr, int clear_nosave_free)
257 BUG_ON(!virt_addr_valid(addr));
259 page = virt_to_page(addr);
261 swsusp_unset_page_forbidden(page);
262 if (clear_nosave_free)
263 swsusp_unset_page_free(page);
268 static inline void free_list_of_pages(struct linked_page *list,
269 int clear_page_nosave)
272 struct linked_page *lp = list->next;
274 free_image_page(list, clear_page_nosave);
280 * struct chain_allocator is used for allocating small objects out of
281 * a linked list of pages called 'the chain'.
283 * The chain grows each time when there is no room for a new object in
284 * the current page. The allocated objects cannot be freed individually.
285 * It is only possible to free them all at once, by freeing the entire
288 * NOTE: The chain allocator may be inefficient if the allocated objects
289 * are not much smaller than PAGE_SIZE.
291 struct chain_allocator {
292 struct linked_page *chain; /* the chain */
293 unsigned int used_space; /* total size of objects allocated out
294 of the current page */
295 gfp_t gfp_mask; /* mask for allocating pages */
296 int safe_needed; /* if set, only "safe" pages are allocated */
299 static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
303 ca->used_space = LINKED_PAGE_DATA_SIZE;
304 ca->gfp_mask = gfp_mask;
305 ca->safe_needed = safe_needed;
308 static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
312 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
313 struct linked_page *lp;
315 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
316 get_image_page(ca->gfp_mask, PG_ANY);
320 lp->next = ca->chain;
324 ret = ca->chain->data + ca->used_space;
325 ca->used_space += size;
330 * Data types related to memory bitmaps.
332 * Memory bitmap is a structure consiting of many linked lists of
333 * objects. The main list's elements are of type struct zone_bitmap
334 * and each of them corresonds to one zone. For each zone bitmap
335 * object there is a list of objects of type struct bm_block that
336 * represent each blocks of bitmap in which information is stored.
338 * struct memory_bitmap contains a pointer to the main list of zone
339 * bitmap objects, a struct bm_position used for browsing the bitmap,
340 * and a pointer to the list of pages used for allocating all of the
341 * zone bitmap objects and bitmap block objects.
343 * NOTE: It has to be possible to lay out the bitmap in memory
344 * using only allocations of order 0. Additionally, the bitmap is
345 * designed to work with arbitrary number of zones (this is over the
346 * top for now, but let's avoid making unnecessary assumptions ;-).
348 * struct zone_bitmap contains a pointer to a list of bitmap block
349 * objects and a pointer to the bitmap block object that has been
350 * most recently used for setting bits. Additionally, it contains the
351 * PFNs that correspond to the start and end of the represented zone.
353 * struct bm_block contains a pointer to the memory page in which
354 * information is stored (in the form of a block of bitmap)
355 * It also contains the pfns that correspond to the start and end of
356 * the represented memory area.
358 * The memory bitmap is organized as a radix tree to guarantee fast random
359 * access to the bits. There is one radix tree for each zone (as returned
360 * from create_mem_extents).
362 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
363 * two linked lists for the nodes of the tree, one for the inner nodes and
364 * one for the leave nodes. The linked leave nodes are used for fast linear
365 * access of the memory bitmap.
367 * The struct rtree_node represents one node of the radix tree.
370 #define BM_END_OF_MAP (~0UL)
372 #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
373 #define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
374 #define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
377 * struct rtree_node is a wrapper struct to link the nodes
378 * of the rtree together for easy linear iteration over
379 * bits and easy freeing
382 struct list_head list;
387 * struct mem_zone_bm_rtree represents a bitmap used for one
388 * populated memory zone.
390 struct mem_zone_bm_rtree {
391 struct list_head list; /* Link Zones together */
392 struct list_head nodes; /* Radix Tree inner nodes */
393 struct list_head leaves; /* Radix Tree leaves */
394 unsigned long start_pfn; /* Zone start page frame */
395 unsigned long end_pfn; /* Zone end page frame + 1 */
396 struct rtree_node *rtree; /* Radix Tree Root */
397 int levels; /* Number of Radix Tree Levels */
398 unsigned int blocks; /* Number of Bitmap Blocks */
401 /* strcut bm_position is used for browsing memory bitmaps */
404 struct mem_zone_bm_rtree *zone;
405 struct rtree_node *node;
406 unsigned long node_pfn;
410 struct memory_bitmap {
411 struct list_head zones;
412 struct linked_page *p_list; /* list of pages used to store zone
413 bitmap objects and bitmap block
415 struct bm_position cur; /* most recently used bit position */
418 /* Functions that operate on memory bitmaps */
420 #define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
421 #if BITS_PER_LONG == 32
422 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
424 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
426 #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
429 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
431 * This function is used to allocate inner nodes as well as the
432 * leave nodes of the radix tree. It also adds the node to the
433 * corresponding linked list passed in by the *list parameter.
435 static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
436 struct chain_allocator *ca,
437 struct list_head *list)
439 struct rtree_node *node;
441 node = chain_alloc(ca, sizeof(struct rtree_node));
445 node->data = get_image_page(gfp_mask, safe_needed);
449 list_add_tail(&node->list, list);
455 * add_rtree_block - Add a new leave node to the radix tree.
457 * The leave nodes need to be allocated in order to keep the leaves
458 * linked list in order. This is guaranteed by the zone->blocks
461 static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
462 int safe_needed, struct chain_allocator *ca)
464 struct rtree_node *node, *block, **dst;
465 unsigned int levels_needed, block_nr;
468 block_nr = zone->blocks;
471 /* How many levels do we need for this block nr? */
474 block_nr >>= BM_RTREE_LEVEL_SHIFT;
477 /* Make sure the rtree has enough levels */
478 for (i = zone->levels; i < levels_needed; i++) {
479 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
484 node->data[0] = (unsigned long)zone->rtree;
489 /* Allocate new block */
490 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
494 /* Now walk the rtree to insert the block */
497 block_nr = zone->blocks;
498 for (i = zone->levels; i > 0; i--) {
502 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
509 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
510 index &= BM_RTREE_LEVEL_MASK;
511 dst = (struct rtree_node **)&((*dst)->data[index]);
521 static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
522 int clear_nosave_free);
525 * create_zone_bm_rtree - Create a radix tree for one zone.
527 * Allocated the mem_zone_bm_rtree structure and initializes it.
528 * This function also allocated and builds the radix tree for the
531 static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
533 struct chain_allocator *ca,
537 struct mem_zone_bm_rtree *zone;
538 unsigned int i, nr_blocks;
542 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
546 INIT_LIST_HEAD(&zone->nodes);
547 INIT_LIST_HEAD(&zone->leaves);
548 zone->start_pfn = start;
550 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
552 for (i = 0; i < nr_blocks; i++) {
553 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
554 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
563 * free_zone_bm_rtree - Free the memory of the radix tree.
565 * Free all node pages of the radix tree. The mem_zone_bm_rtree
566 * structure itself is not freed here nor are the rtree_node
569 static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
570 int clear_nosave_free)
572 struct rtree_node *node;
574 list_for_each_entry(node, &zone->nodes, list)
575 free_image_page(node->data, clear_nosave_free);
577 list_for_each_entry(node, &zone->leaves, list)
578 free_image_page(node->data, clear_nosave_free);
581 static void memory_bm_position_reset(struct memory_bitmap *bm)
583 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
585 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
586 struct rtree_node, list);
587 bm->cur.node_pfn = 0;
588 bm->cur.node_bit = 0;
591 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
594 struct list_head hook;
600 * free_mem_extents - Free a list of memory extents.
601 * @list: List of extents to free.
603 static void free_mem_extents(struct list_head *list)
605 struct mem_extent *ext, *aux;
607 list_for_each_entry_safe(ext, aux, list, hook) {
608 list_del(&ext->hook);
614 * create_mem_extents - Create a list of memory extents.
615 * @list: List to put the extents into.
616 * @gfp_mask: Mask to use for memory allocations.
618 * The extents represent contiguous ranges of PFNs.
620 static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
624 INIT_LIST_HEAD(list);
626 for_each_populated_zone(zone) {
627 unsigned long zone_start, zone_end;
628 struct mem_extent *ext, *cur, *aux;
630 zone_start = zone->zone_start_pfn;
631 zone_end = zone_end_pfn(zone);
633 list_for_each_entry(ext, list, hook)
634 if (zone_start <= ext->end)
637 if (&ext->hook == list || zone_end < ext->start) {
638 /* New extent is necessary */
639 struct mem_extent *new_ext;
641 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
643 free_mem_extents(list);
646 new_ext->start = zone_start;
647 new_ext->end = zone_end;
648 list_add_tail(&new_ext->hook, &ext->hook);
652 /* Merge this zone's range of PFNs with the existing one */
653 if (zone_start < ext->start)
654 ext->start = zone_start;
655 if (zone_end > ext->end)
658 /* More merging may be possible */
660 list_for_each_entry_safe_continue(cur, aux, list, hook) {
661 if (zone_end < cur->start)
663 if (zone_end < cur->end)
665 list_del(&cur->hook);
674 * memory_bm_create - Allocate memory for a memory bitmap.
676 static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
679 struct chain_allocator ca;
680 struct list_head mem_extents;
681 struct mem_extent *ext;
684 chain_init(&ca, gfp_mask, safe_needed);
685 INIT_LIST_HEAD(&bm->zones);
687 error = create_mem_extents(&mem_extents, gfp_mask);
691 list_for_each_entry(ext, &mem_extents, hook) {
692 struct mem_zone_bm_rtree *zone;
694 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
695 ext->start, ext->end);
700 list_add_tail(&zone->list, &bm->zones);
703 bm->p_list = ca.chain;
704 memory_bm_position_reset(bm);
706 free_mem_extents(&mem_extents);
710 bm->p_list = ca.chain;
711 memory_bm_free(bm, PG_UNSAFE_CLEAR);
716 * memory_bm_free - Free memory occupied by the memory bitmap.
717 * @bm: Memory bitmap.
719 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
721 struct mem_zone_bm_rtree *zone;
723 list_for_each_entry(zone, &bm->zones, list)
724 free_zone_bm_rtree(zone, clear_nosave_free);
726 free_list_of_pages(bm->p_list, clear_nosave_free);
728 INIT_LIST_HEAD(&bm->zones);
732 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
734 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
735 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
737 * Walk the radix tree to find the page containing the bit that represents @pfn
738 * and return the position of the bit in @addr and @bit_nr.
740 static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
741 void **addr, unsigned int *bit_nr)
743 struct mem_zone_bm_rtree *curr, *zone;
744 struct rtree_node *node;
749 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
754 /* Find the right zone */
755 list_for_each_entry(curr, &bm->zones, list) {
756 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
767 * We have found the zone. Now walk the radix tree to find the leaf node
772 * If the zone we wish to scan is the current zone and the
773 * pfn falls into the current node then we do not need to walk
777 if (zone == bm->cur.zone &&
778 ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
782 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
784 for (i = zone->levels; i > 0; i--) {
787 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
788 index &= BM_RTREE_LEVEL_MASK;
789 BUG_ON(node->data[index] == 0);
790 node = (struct rtree_node *)node->data[index];
794 /* Update last position */
797 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
799 /* Set return values */
801 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
806 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
812 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
817 static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
823 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
830 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
836 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
838 clear_bit(bit, addr);
841 static void memory_bm_clear_current(struct memory_bitmap *bm)
845 bit = max(bm->cur.node_bit - 1, 0);
846 clear_bit(bit, bm->cur.node->data);
849 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
855 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
857 return test_bit(bit, addr);
860 static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
865 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
869 * rtree_next_node - Jump to the next leaf node.
871 * Set the position to the beginning of the next node in the
872 * memory bitmap. This is either the next node in the current
873 * zone's radix tree or the first node in the radix tree of the
876 * Return true if there is a next node, false otherwise.
878 static bool rtree_next_node(struct memory_bitmap *bm)
880 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
881 bm->cur.node = list_entry(bm->cur.node->list.next,
882 struct rtree_node, list);
883 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
884 bm->cur.node_bit = 0;
885 touch_softlockup_watchdog();
889 /* No more nodes, goto next zone */
890 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
891 bm->cur.zone = list_entry(bm->cur.zone->list.next,
892 struct mem_zone_bm_rtree, list);
893 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
894 struct rtree_node, list);
895 bm->cur.node_pfn = 0;
896 bm->cur.node_bit = 0;
905 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
906 * @bm: Memory bitmap.
908 * Starting from the last returned position this function searches for the next
909 * set bit in @bm and returns the PFN represented by it. If no more bits are
910 * set, BM_END_OF_MAP is returned.
912 * It is required to run memory_bm_position_reset() before the first call to
913 * this function for the given memory bitmap.
915 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
917 unsigned long bits, pfn, pages;
921 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
922 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
923 bit = find_next_bit(bm->cur.node->data, bits,
926 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
927 bm->cur.node_bit = bit + 1;
930 } while (rtree_next_node(bm));
932 return BM_END_OF_MAP;
936 * This structure represents a range of page frames the contents of which
937 * should not be saved during hibernation.
939 struct nosave_region {
940 struct list_head list;
941 unsigned long start_pfn;
942 unsigned long end_pfn;
945 static LIST_HEAD(nosave_regions);
947 static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
949 struct rtree_node *node;
951 list_for_each_entry(node, &zone->nodes, list)
952 recycle_safe_page(node->data);
954 list_for_each_entry(node, &zone->leaves, list)
955 recycle_safe_page(node->data);
958 static void memory_bm_recycle(struct memory_bitmap *bm)
960 struct mem_zone_bm_rtree *zone;
961 struct linked_page *p_list;
963 list_for_each_entry(zone, &bm->zones, list)
964 recycle_zone_bm_rtree(zone);
968 struct linked_page *lp = p_list;
971 recycle_safe_page(lp);
976 * register_nosave_region - Register a region of unsaveable memory.
978 * Register a range of page frames the contents of which should not be saved
979 * during hibernation (to be used in the early initialization code).
981 void __init __register_nosave_region(unsigned long start_pfn,
982 unsigned long end_pfn, int use_kmalloc)
984 struct nosave_region *region;
986 if (start_pfn >= end_pfn)
989 if (!list_empty(&nosave_regions)) {
990 /* Try to extend the previous region (they should be sorted) */
991 region = list_entry(nosave_regions.prev,
992 struct nosave_region, list);
993 if (region->end_pfn == start_pfn) {
994 region->end_pfn = end_pfn;
999 /* During init, this shouldn't fail */
1000 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
1003 /* This allocation cannot fail */
1004 region = memblock_alloc(sizeof(struct nosave_region),
1007 panic("%s: Failed to allocate %zu bytes\n", __func__,
1008 sizeof(struct nosave_region));
1010 region->start_pfn = start_pfn;
1011 region->end_pfn = end_pfn;
1012 list_add_tail(®ion->list, &nosave_regions);
1014 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
1015 (unsigned long long) start_pfn << PAGE_SHIFT,
1016 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
1020 * Set bits in this map correspond to the page frames the contents of which
1021 * should not be saved during the suspend.
1023 static struct memory_bitmap *forbidden_pages_map;
1025 /* Set bits in this map correspond to free page frames. */
1026 static struct memory_bitmap *free_pages_map;
1029 * Each page frame allocated for creating the image is marked by setting the
1030 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
1033 void swsusp_set_page_free(struct page *page)
1036 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
1039 static int swsusp_page_is_free(struct page *page)
1041 return free_pages_map ?
1042 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1045 void swsusp_unset_page_free(struct page *page)
1048 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1051 static void swsusp_set_page_forbidden(struct page *page)
1053 if (forbidden_pages_map)
1054 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1057 int swsusp_page_is_forbidden(struct page *page)
1059 return forbidden_pages_map ?
1060 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1063 static void swsusp_unset_page_forbidden(struct page *page)
1065 if (forbidden_pages_map)
1066 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1070 * mark_nosave_pages - Mark pages that should not be saved.
1071 * @bm: Memory bitmap.
1073 * Set the bits in @bm that correspond to the page frames the contents of which
1074 * should not be saved.
1076 static void mark_nosave_pages(struct memory_bitmap *bm)
1078 struct nosave_region *region;
1080 if (list_empty(&nosave_regions))
1083 list_for_each_entry(region, &nosave_regions, list) {
1086 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1087 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1088 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1091 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1092 if (pfn_valid(pfn)) {
1094 * It is safe to ignore the result of
1095 * mem_bm_set_bit_check() here, since we won't
1096 * touch the PFNs for which the error is
1099 mem_bm_set_bit_check(bm, pfn);
1105 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1107 * Create bitmaps needed for marking page frames that should not be saved and
1108 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1109 * only modified if everything goes well, because we don't want the bits to be
1110 * touched before both bitmaps are set up.
1112 int create_basic_memory_bitmaps(void)
1114 struct memory_bitmap *bm1, *bm2;
1117 if (forbidden_pages_map && free_pages_map)
1120 BUG_ON(forbidden_pages_map || free_pages_map);
1122 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1126 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1128 goto Free_first_object;
1130 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1132 goto Free_first_bitmap;
1134 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1136 goto Free_second_object;
1138 forbidden_pages_map = bm1;
1139 free_pages_map = bm2;
1140 mark_nosave_pages(forbidden_pages_map);
1142 pr_debug("Basic memory bitmaps created\n");
1149 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1156 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1158 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1159 * auxiliary pointers are necessary so that the bitmaps themselves are not
1160 * referred to while they are being freed.
1162 void free_basic_memory_bitmaps(void)
1164 struct memory_bitmap *bm1, *bm2;
1166 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1169 bm1 = forbidden_pages_map;
1170 bm2 = free_pages_map;
1171 forbidden_pages_map = NULL;
1172 free_pages_map = NULL;
1173 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1175 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1178 pr_debug("Basic memory bitmaps freed\n");
1181 static void clear_or_poison_free_page(struct page *page)
1183 if (page_poisoning_enabled_static())
1184 __kernel_poison_pages(page, 1);
1185 else if (want_init_on_free())
1186 clear_highpage(page);
1189 void clear_or_poison_free_pages(void)
1191 struct memory_bitmap *bm = free_pages_map;
1194 if (WARN_ON(!(free_pages_map)))
1197 if (page_poisoning_enabled() || want_init_on_free()) {
1198 memory_bm_position_reset(bm);
1199 pfn = memory_bm_next_pfn(bm);
1200 while (pfn != BM_END_OF_MAP) {
1202 clear_or_poison_free_page(pfn_to_page(pfn));
1204 pfn = memory_bm_next_pfn(bm);
1206 memory_bm_position_reset(bm);
1207 pr_info("free pages cleared after restore\n");
1212 * snapshot_additional_pages - Estimate the number of extra pages needed.
1213 * @zone: Memory zone to carry out the computation for.
1215 * Estimate the number of additional pages needed for setting up a hibernation
1216 * image data structures for @zone (usually, the returned value is greater than
1217 * the exact number).
1219 unsigned int snapshot_additional_pages(struct zone *zone)
1221 unsigned int rtree, nodes;
1223 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1224 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1225 LINKED_PAGE_DATA_SIZE);
1227 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1234 #ifdef CONFIG_HIGHMEM
1236 * count_free_highmem_pages - Compute the total number of free highmem pages.
1238 * The returned number is system-wide.
1240 static unsigned int count_free_highmem_pages(void)
1243 unsigned int cnt = 0;
1245 for_each_populated_zone(zone)
1246 if (is_highmem(zone))
1247 cnt += zone_page_state(zone, NR_FREE_PAGES);
1253 * saveable_highmem_page - Check if a highmem page is saveable.
1255 * Determine whether a highmem page should be included in a hibernation image.
1257 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1258 * and it isn't part of a free chunk of pages.
1260 static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1264 if (!pfn_valid(pfn))
1267 page = pfn_to_online_page(pfn);
1268 if (!page || page_zone(page) != zone)
1271 BUG_ON(!PageHighMem(page));
1273 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1276 if (PageReserved(page) || PageOffline(page))
1279 if (page_is_guard(page))
1286 * count_highmem_pages - Compute the total number of saveable highmem pages.
1288 static unsigned int count_highmem_pages(void)
1293 for_each_populated_zone(zone) {
1294 unsigned long pfn, max_zone_pfn;
1296 if (!is_highmem(zone))
1299 mark_free_pages(zone);
1300 max_zone_pfn = zone_end_pfn(zone);
1301 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1302 if (saveable_highmem_page(zone, pfn))
1308 static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1312 #endif /* CONFIG_HIGHMEM */
1315 * saveable_page - Check if the given page is saveable.
1317 * Determine whether a non-highmem page should be included in a hibernation
1320 * We should save the page if it isn't Nosave, and is not in the range
1321 * of pages statically defined as 'unsaveable', and it isn't part of
1322 * a free chunk of pages.
1324 static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1328 if (!pfn_valid(pfn))
1331 page = pfn_to_online_page(pfn);
1332 if (!page || page_zone(page) != zone)
1335 BUG_ON(PageHighMem(page));
1337 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1340 if (PageOffline(page))
1343 if (PageReserved(page)
1344 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1347 if (page_is_guard(page))
1354 * count_data_pages - Compute the total number of saveable non-highmem pages.
1356 static unsigned int count_data_pages(void)
1359 unsigned long pfn, max_zone_pfn;
1362 for_each_populated_zone(zone) {
1363 if (is_highmem(zone))
1366 mark_free_pages(zone);
1367 max_zone_pfn = zone_end_pfn(zone);
1368 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1369 if (saveable_page(zone, pfn))
1376 * This is needed, because copy_page and memcpy are not usable for copying
1379 static inline void do_copy_page(long *dst, long *src)
1383 for (n = PAGE_SIZE / sizeof(long); n; n--)
1388 * safe_copy_page - Copy a page in a safe way.
1390 * Check if the page we are going to copy is marked as present in the kernel
1391 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1392 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1393 * always returns 'true'.
1395 static void safe_copy_page(void *dst, struct page *s_page)
1397 if (kernel_page_present(s_page)) {
1398 do_copy_page(dst, page_address(s_page));
1400 hibernate_map_page(s_page);
1401 do_copy_page(dst, page_address(s_page));
1402 hibernate_unmap_page(s_page);
1406 #ifdef CONFIG_HIGHMEM
1407 static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1409 return is_highmem(zone) ?
1410 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1413 static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1415 struct page *s_page, *d_page;
1418 s_page = pfn_to_page(src_pfn);
1419 d_page = pfn_to_page(dst_pfn);
1420 if (PageHighMem(s_page)) {
1421 src = kmap_atomic(s_page);
1422 dst = kmap_atomic(d_page);
1423 do_copy_page(dst, src);
1427 if (PageHighMem(d_page)) {
1429 * The page pointed to by src may contain some kernel
1430 * data modified by kmap_atomic()
1432 safe_copy_page(buffer, s_page);
1433 dst = kmap_atomic(d_page);
1434 copy_page(dst, buffer);
1437 safe_copy_page(page_address(d_page), s_page);
1442 #define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1444 static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1446 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1447 pfn_to_page(src_pfn));
1449 #endif /* CONFIG_HIGHMEM */
1451 static void copy_data_pages(struct memory_bitmap *copy_bm,
1452 struct memory_bitmap *orig_bm)
1457 for_each_populated_zone(zone) {
1458 unsigned long max_zone_pfn;
1460 mark_free_pages(zone);
1461 max_zone_pfn = zone_end_pfn(zone);
1462 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1463 if (page_is_saveable(zone, pfn))
1464 memory_bm_set_bit(orig_bm, pfn);
1466 memory_bm_position_reset(orig_bm);
1467 memory_bm_position_reset(copy_bm);
1469 pfn = memory_bm_next_pfn(orig_bm);
1470 if (unlikely(pfn == BM_END_OF_MAP))
1472 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1476 /* Total number of image pages */
1477 static unsigned int nr_copy_pages;
1478 /* Number of pages needed for saving the original pfns of the image pages */
1479 static unsigned int nr_meta_pages;
1481 * Numbers of normal and highmem page frames allocated for hibernation image
1482 * before suspending devices.
1484 static unsigned int alloc_normal, alloc_highmem;
1486 * Memory bitmap used for marking saveable pages (during hibernation) or
1487 * hibernation image pages (during restore)
1489 static struct memory_bitmap orig_bm;
1491 * Memory bitmap used during hibernation for marking allocated page frames that
1492 * will contain copies of saveable pages. During restore it is initially used
1493 * for marking hibernation image pages, but then the set bits from it are
1494 * duplicated in @orig_bm and it is released. On highmem systems it is next
1495 * used for marking "safe" highmem pages, but it has to be reinitialized for
1498 static struct memory_bitmap copy_bm;
1501 * swsusp_free - Free pages allocated for hibernation image.
1503 * Image pages are alocated before snapshot creation, so they need to be
1504 * released after resume.
1506 void swsusp_free(void)
1508 unsigned long fb_pfn, fr_pfn;
1510 if (!forbidden_pages_map || !free_pages_map)
1513 memory_bm_position_reset(forbidden_pages_map);
1514 memory_bm_position_reset(free_pages_map);
1517 fr_pfn = memory_bm_next_pfn(free_pages_map);
1518 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1521 * Find the next bit set in both bitmaps. This is guaranteed to
1522 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1525 if (fb_pfn < fr_pfn)
1526 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1527 if (fr_pfn < fb_pfn)
1528 fr_pfn = memory_bm_next_pfn(free_pages_map);
1529 } while (fb_pfn != fr_pfn);
1531 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1532 struct page *page = pfn_to_page(fr_pfn);
1534 memory_bm_clear_current(forbidden_pages_map);
1535 memory_bm_clear_current(free_pages_map);
1536 hibernate_restore_unprotect_page(page_address(page));
1544 restore_pblist = NULL;
1548 hibernate_restore_protection_end();
1551 /* Helper functions used for the shrinking of memory. */
1553 #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1556 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1557 * @nr_pages: Number of page frames to allocate.
1558 * @mask: GFP flags to use for the allocation.
1560 * Return value: Number of page frames actually allocated
1562 static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1564 unsigned long nr_alloc = 0;
1566 while (nr_pages > 0) {
1569 page = alloc_image_page(mask);
1572 memory_bm_set_bit(©_bm, page_to_pfn(page));
1573 if (PageHighMem(page))
1584 static unsigned long preallocate_image_memory(unsigned long nr_pages,
1585 unsigned long avail_normal)
1587 unsigned long alloc;
1589 if (avail_normal <= alloc_normal)
1592 alloc = avail_normal - alloc_normal;
1593 if (nr_pages < alloc)
1596 return preallocate_image_pages(alloc, GFP_IMAGE);
1599 #ifdef CONFIG_HIGHMEM
1600 static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1602 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1606 * __fraction - Compute (an approximation of) x * (multiplier / base).
1608 static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1610 return div64_u64(x * multiplier, base);
1613 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1614 unsigned long highmem,
1615 unsigned long total)
1617 unsigned long alloc = __fraction(nr_pages, highmem, total);
1619 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1621 #else /* CONFIG_HIGHMEM */
1622 static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1627 static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1628 unsigned long highmem,
1629 unsigned long total)
1633 #endif /* CONFIG_HIGHMEM */
1636 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1638 static unsigned long free_unnecessary_pages(void)
1640 unsigned long save, to_free_normal, to_free_highmem, free;
1642 save = count_data_pages();
1643 if (alloc_normal >= save) {
1644 to_free_normal = alloc_normal - save;
1648 save -= alloc_normal;
1650 save += count_highmem_pages();
1651 if (alloc_highmem >= save) {
1652 to_free_highmem = alloc_highmem - save;
1654 to_free_highmem = 0;
1655 save -= alloc_highmem;
1656 if (to_free_normal > save)
1657 to_free_normal -= save;
1661 free = to_free_normal + to_free_highmem;
1663 memory_bm_position_reset(©_bm);
1665 while (to_free_normal > 0 || to_free_highmem > 0) {
1666 unsigned long pfn = memory_bm_next_pfn(©_bm);
1667 struct page *page = pfn_to_page(pfn);
1669 if (PageHighMem(page)) {
1670 if (!to_free_highmem)
1675 if (!to_free_normal)
1680 memory_bm_clear_bit(©_bm, pfn);
1681 swsusp_unset_page_forbidden(page);
1682 swsusp_unset_page_free(page);
1690 * minimum_image_size - Estimate the minimum acceptable size of an image.
1691 * @saveable: Number of saveable pages in the system.
1693 * We want to avoid attempting to free too much memory too hard, so estimate the
1694 * minimum acceptable size of a hibernation image to use as the lower limit for
1695 * preallocating memory.
1697 * We assume that the minimum image size should be proportional to
1699 * [number of saveable pages] - [number of pages that can be freed in theory]
1701 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1702 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1704 static unsigned long minimum_image_size(unsigned long saveable)
1708 size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
1709 + global_node_page_state(NR_ACTIVE_ANON)
1710 + global_node_page_state(NR_INACTIVE_ANON)
1711 + global_node_page_state(NR_ACTIVE_FILE)
1712 + global_node_page_state(NR_INACTIVE_FILE);
1714 return saveable <= size ? 0 : saveable - size;
1718 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1720 * To create a hibernation image it is necessary to make a copy of every page
1721 * frame in use. We also need a number of page frames to be free during
1722 * hibernation for allocations made while saving the image and for device
1723 * drivers, in case they need to allocate memory from their hibernation
1724 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1725 * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1726 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1727 * total number of available page frames and allocate at least
1729 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1730 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1732 * of them, which corresponds to the maximum size of a hibernation image.
1734 * If image_size is set below the number following from the above formula,
1735 * the preallocation of memory is continued until the total number of saveable
1736 * pages in the system is below the requested image size or the minimum
1737 * acceptable image size returned by minimum_image_size(), whichever is greater.
1739 int hibernate_preallocate_memory(void)
1742 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1743 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1744 ktime_t start, stop;
1747 pr_info("Preallocating image memory\n");
1748 start = ktime_get();
1750 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1752 pr_err("Cannot allocate original bitmap\n");
1756 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1758 pr_err("Cannot allocate copy bitmap\n");
1765 /* Count the number of saveable data pages. */
1766 save_highmem = count_highmem_pages();
1767 saveable = count_data_pages();
1770 * Compute the total number of page frames we can use (count) and the
1771 * number of pages needed for image metadata (size).
1774 saveable += save_highmem;
1775 highmem = save_highmem;
1777 for_each_populated_zone(zone) {
1778 size += snapshot_additional_pages(zone);
1779 if (is_highmem(zone))
1780 highmem += zone_page_state(zone, NR_FREE_PAGES);
1782 count += zone_page_state(zone, NR_FREE_PAGES);
1784 avail_normal = count;
1786 count -= totalreserve_pages;
1788 /* Compute the maximum number of saveable pages to leave in memory. */
1789 max_size = (count - (size + PAGES_FOR_IO)) / 2
1790 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1791 /* Compute the desired number of image pages specified by image_size. */
1792 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1793 if (size > max_size)
1796 * If the desired number of image pages is at least as large as the
1797 * current number of saveable pages in memory, allocate page frames for
1798 * the image and we're done.
1800 if (size >= saveable) {
1801 pages = preallocate_image_highmem(save_highmem);
1802 pages += preallocate_image_memory(saveable - pages, avail_normal);
1806 /* Estimate the minimum size of the image. */
1807 pages = minimum_image_size(saveable);
1809 * To avoid excessive pressure on the normal zone, leave room in it to
1810 * accommodate an image of the minimum size (unless it's already too
1811 * small, in which case don't preallocate pages from it at all).
1813 if (avail_normal > pages)
1814 avail_normal -= pages;
1818 size = min_t(unsigned long, pages, max_size);
1821 * Let the memory management subsystem know that we're going to need a
1822 * large number of page frames to allocate and make it free some memory.
1823 * NOTE: If this is not done, performance will be hurt badly in some
1826 shrink_all_memory(saveable - size);
1829 * The number of saveable pages in memory was too high, so apply some
1830 * pressure to decrease it. First, make room for the largest possible
1831 * image and fail if that doesn't work. Next, try to decrease the size
1832 * of the image as much as indicated by 'size' using allocations from
1833 * highmem and non-highmem zones separately.
1835 pages_highmem = preallocate_image_highmem(highmem / 2);
1836 alloc = count - max_size;
1837 if (alloc > pages_highmem)
1838 alloc -= pages_highmem;
1841 pages = preallocate_image_memory(alloc, avail_normal);
1842 if (pages < alloc) {
1843 /* We have exhausted non-highmem pages, try highmem. */
1845 pages += pages_highmem;
1846 pages_highmem = preallocate_image_highmem(alloc);
1847 if (pages_highmem < alloc) {
1848 pr_err("Image allocation is %lu pages short\n",
1849 alloc - pages_highmem);
1852 pages += pages_highmem;
1854 * size is the desired number of saveable pages to leave in
1855 * memory, so try to preallocate (all memory - size) pages.
1857 alloc = (count - pages) - size;
1858 pages += preallocate_image_highmem(alloc);
1861 * There are approximately max_size saveable pages at this point
1862 * and we want to reduce this number down to size.
1864 alloc = max_size - size;
1865 size = preallocate_highmem_fraction(alloc, highmem, count);
1866 pages_highmem += size;
1868 size = preallocate_image_memory(alloc, avail_normal);
1869 pages_highmem += preallocate_image_highmem(alloc - size);
1870 pages += pages_highmem + size;
1874 * We only need as many page frames for the image as there are saveable
1875 * pages in memory, but we have allocated more. Release the excessive
1878 pages -= free_unnecessary_pages();
1882 pr_info("Allocated %lu pages for snapshot\n", pages);
1883 swsusp_show_speed(start, stop, pages, "Allocated");
1892 #ifdef CONFIG_HIGHMEM
1894 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1896 * Compute the number of non-highmem pages that will be necessary for creating
1897 * copies of highmem pages.
1899 static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1901 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1903 if (free_highmem >= nr_highmem)
1906 nr_highmem -= free_highmem;
1911 static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1912 #endif /* CONFIG_HIGHMEM */
1915 * enough_free_mem - Check if there is enough free memory for the image.
1917 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1920 unsigned int free = alloc_normal;
1922 for_each_populated_zone(zone)
1923 if (!is_highmem(zone))
1924 free += zone_page_state(zone, NR_FREE_PAGES);
1926 nr_pages += count_pages_for_highmem(nr_highmem);
1927 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1928 nr_pages, PAGES_FOR_IO, free);
1930 return free > nr_pages + PAGES_FOR_IO;
1933 #ifdef CONFIG_HIGHMEM
1935 * get_highmem_buffer - Allocate a buffer for highmem pages.
1937 * If there are some highmem pages in the hibernation image, we may need a
1938 * buffer to copy them and/or load their data.
1940 static inline int get_highmem_buffer(int safe_needed)
1942 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1943 return buffer ? 0 : -ENOMEM;
1947 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1949 * Try to allocate as many pages as needed, but if the number of free highmem
1950 * pages is less than that, allocate them all.
1952 static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1953 unsigned int nr_highmem)
1955 unsigned int to_alloc = count_free_highmem_pages();
1957 if (to_alloc > nr_highmem)
1958 to_alloc = nr_highmem;
1960 nr_highmem -= to_alloc;
1961 while (to_alloc-- > 0) {
1964 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1965 memory_bm_set_bit(bm, page_to_pfn(page));
1970 static inline int get_highmem_buffer(int safe_needed) { return 0; }
1972 static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1973 unsigned int n) { return 0; }
1974 #endif /* CONFIG_HIGHMEM */
1977 * swsusp_alloc - Allocate memory for hibernation image.
1979 * We first try to allocate as many highmem pages as there are
1980 * saveable highmem pages in the system. If that fails, we allocate
1981 * non-highmem pages for the copies of the remaining highmem ones.
1983 * In this approach it is likely that the copies of highmem pages will
1984 * also be located in the high memory, because of the way in which
1985 * copy_data_pages() works.
1987 static int swsusp_alloc(struct memory_bitmap *copy_bm,
1988 unsigned int nr_pages, unsigned int nr_highmem)
1990 if (nr_highmem > 0) {
1991 if (get_highmem_buffer(PG_ANY))
1993 if (nr_highmem > alloc_highmem) {
1994 nr_highmem -= alloc_highmem;
1995 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1998 if (nr_pages > alloc_normal) {
1999 nr_pages -= alloc_normal;
2000 while (nr_pages-- > 0) {
2003 page = alloc_image_page(GFP_ATOMIC);
2006 memory_bm_set_bit(copy_bm, page_to_pfn(page));
2017 asmlinkage __visible int swsusp_save(void)
2019 unsigned int nr_pages, nr_highmem;
2021 pr_info("Creating image:\n");
2023 drain_local_pages(NULL);
2024 nr_pages = count_data_pages();
2025 nr_highmem = count_highmem_pages();
2026 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
2028 if (!enough_free_mem(nr_pages, nr_highmem)) {
2029 pr_err("Not enough free memory\n");
2033 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
2034 pr_err("Memory allocation failed\n");
2039 * During allocating of suspend pagedir, new cold pages may appear.
2042 drain_local_pages(NULL);
2043 copy_data_pages(©_bm, &orig_bm);
2046 * End of critical section. From now on, we can write to memory,
2047 * but we should not touch disk. This specially means we must _not_
2048 * touch swap space! Except we must write out our image of course.
2051 nr_pages += nr_highmem;
2052 nr_copy_pages = nr_pages;
2053 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2055 pr_info("Image created (%d pages copied)\n", nr_pages);
2060 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
2061 static int init_header_complete(struct swsusp_info *info)
2063 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2064 info->version_code = LINUX_VERSION_CODE;
2068 static const char *check_image_kernel(struct swsusp_info *info)
2070 if (info->version_code != LINUX_VERSION_CODE)
2071 return "kernel version";
2072 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2073 return "system type";
2074 if (strcmp(info->uts.release,init_utsname()->release))
2075 return "kernel release";
2076 if (strcmp(info->uts.version,init_utsname()->version))
2078 if (strcmp(info->uts.machine,init_utsname()->machine))
2082 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2084 unsigned long snapshot_get_image_size(void)
2086 return nr_copy_pages + nr_meta_pages + 1;
2089 static int init_header(struct swsusp_info *info)
2091 memset(info, 0, sizeof(struct swsusp_info));
2092 info->num_physpages = get_num_physpages();
2093 info->image_pages = nr_copy_pages;
2094 info->pages = snapshot_get_image_size();
2095 info->size = info->pages;
2096 info->size <<= PAGE_SHIFT;
2097 return init_header_complete(info);
2101 * pack_pfns - Prepare PFNs for saving.
2102 * @bm: Memory bitmap.
2103 * @buf: Memory buffer to store the PFNs in.
2105 * PFNs corresponding to set bits in @bm are stored in the area of memory
2106 * pointed to by @buf (1 page at a time).
2108 static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2112 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2113 buf[j] = memory_bm_next_pfn(bm);
2114 if (unlikely(buf[j] == BM_END_OF_MAP))
2120 * snapshot_read_next - Get the address to read the next image page from.
2121 * @handle: Snapshot handle to be used for the reading.
2123 * On the first call, @handle should point to a zeroed snapshot_handle
2124 * structure. The structure gets populated then and a pointer to it should be
2125 * passed to this function every next time.
2127 * On success, the function returns a positive number. Then, the caller
2128 * is allowed to read up to the returned number of bytes from the memory
2129 * location computed by the data_of() macro.
2131 * The function returns 0 to indicate the end of the data stream condition,
2132 * and negative numbers are returned on errors. If that happens, the structure
2133 * pointed to by @handle is not updated and should not be used any more.
2135 int snapshot_read_next(struct snapshot_handle *handle)
2137 if (handle->cur > nr_meta_pages + nr_copy_pages)
2141 /* This makes the buffer be freed by swsusp_free() */
2142 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2149 error = init_header((struct swsusp_info *)buffer);
2152 handle->buffer = buffer;
2153 memory_bm_position_reset(&orig_bm);
2154 memory_bm_position_reset(©_bm);
2155 } else if (handle->cur <= nr_meta_pages) {
2157 pack_pfns(buffer, &orig_bm);
2161 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2162 if (PageHighMem(page)) {
2164 * Highmem pages are copied to the buffer,
2165 * because we can't return with a kmapped
2166 * highmem page (we may not be called again).
2170 kaddr = kmap_atomic(page);
2171 copy_page(buffer, kaddr);
2172 kunmap_atomic(kaddr);
2173 handle->buffer = buffer;
2175 handle->buffer = page_address(page);
2182 static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2183 struct memory_bitmap *src)
2187 memory_bm_position_reset(src);
2188 pfn = memory_bm_next_pfn(src);
2189 while (pfn != BM_END_OF_MAP) {
2190 memory_bm_set_bit(dst, pfn);
2191 pfn = memory_bm_next_pfn(src);
2196 * mark_unsafe_pages - Mark pages that were used before hibernation.
2198 * Mark the pages that cannot be used for storing the image during restoration,
2199 * because they conflict with the pages that had been used before hibernation.
2201 static void mark_unsafe_pages(struct memory_bitmap *bm)
2205 /* Clear the "free"/"unsafe" bit for all PFNs */
2206 memory_bm_position_reset(free_pages_map);
2207 pfn = memory_bm_next_pfn(free_pages_map);
2208 while (pfn != BM_END_OF_MAP) {
2209 memory_bm_clear_current(free_pages_map);
2210 pfn = memory_bm_next_pfn(free_pages_map);
2213 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2214 duplicate_memory_bitmap(free_pages_map, bm);
2216 allocated_unsafe_pages = 0;
2219 static int check_header(struct swsusp_info *info)
2223 reason = check_image_kernel(info);
2224 if (!reason && info->num_physpages != get_num_physpages())
2225 reason = "memory size";
2227 pr_err("Image mismatch: %s\n", reason);
2234 * load header - Check the image header and copy the data from it.
2236 static int load_header(struct swsusp_info *info)
2240 restore_pblist = NULL;
2241 error = check_header(info);
2243 nr_copy_pages = info->image_pages;
2244 nr_meta_pages = info->pages - info->image_pages - 1;
2250 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2251 * @bm: Memory bitmap.
2252 * @buf: Area of memory containing the PFNs.
2254 * For each element of the array pointed to by @buf (1 page at a time), set the
2255 * corresponding bit in @bm.
2257 static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2261 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2262 if (unlikely(buf[j] == BM_END_OF_MAP))
2265 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2266 memory_bm_set_bit(bm, buf[j]);
2274 #ifdef CONFIG_HIGHMEM
2276 * struct highmem_pbe is used for creating the list of highmem pages that
2277 * should be restored atomically during the resume from disk, because the page
2278 * frames they have occupied before the suspend are in use.
2280 struct highmem_pbe {
2281 struct page *copy_page; /* data is here now */
2282 struct page *orig_page; /* data was here before the suspend */
2283 struct highmem_pbe *next;
2287 * List of highmem PBEs needed for restoring the highmem pages that were
2288 * allocated before the suspend and included in the suspend image, but have
2289 * also been allocated by the "resume" kernel, so their contents cannot be
2290 * written directly to their "original" page frames.
2292 static struct highmem_pbe *highmem_pblist;
2295 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2296 * @bm: Memory bitmap.
2298 * The bits in @bm that correspond to image pages are assumed to be set.
2300 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2303 unsigned int cnt = 0;
2305 memory_bm_position_reset(bm);
2306 pfn = memory_bm_next_pfn(bm);
2307 while (pfn != BM_END_OF_MAP) {
2308 if (PageHighMem(pfn_to_page(pfn)))
2311 pfn = memory_bm_next_pfn(bm);
2316 static unsigned int safe_highmem_pages;
2318 static struct memory_bitmap *safe_highmem_bm;
2321 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2322 * @bm: Pointer to an uninitialized memory bitmap structure.
2323 * @nr_highmem_p: Pointer to the number of highmem image pages.
2325 * Try to allocate as many highmem pages as there are highmem image pages
2326 * (@nr_highmem_p points to the variable containing the number of highmem image
2327 * pages). The pages that are "safe" (ie. will not be overwritten when the
2328 * hibernation image is restored entirely) have the corresponding bits set in
2329 * @bm (it must be unitialized).
2331 * NOTE: This function should not be called if there are no highmem image pages.
2333 static int prepare_highmem_image(struct memory_bitmap *bm,
2334 unsigned int *nr_highmem_p)
2336 unsigned int to_alloc;
2338 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2341 if (get_highmem_buffer(PG_SAFE))
2344 to_alloc = count_free_highmem_pages();
2345 if (to_alloc > *nr_highmem_p)
2346 to_alloc = *nr_highmem_p;
2348 *nr_highmem_p = to_alloc;
2350 safe_highmem_pages = 0;
2351 while (to_alloc-- > 0) {
2354 page = alloc_page(__GFP_HIGHMEM);
2355 if (!swsusp_page_is_free(page)) {
2356 /* The page is "safe", set its bit the bitmap */
2357 memory_bm_set_bit(bm, page_to_pfn(page));
2358 safe_highmem_pages++;
2360 /* Mark the page as allocated */
2361 swsusp_set_page_forbidden(page);
2362 swsusp_set_page_free(page);
2364 memory_bm_position_reset(bm);
2365 safe_highmem_bm = bm;
2369 static struct page *last_highmem_page;
2372 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2374 * For a given highmem image page get a buffer that suspend_write_next() should
2375 * return to its caller to write to.
2377 * If the page is to be saved to its "original" page frame or a copy of
2378 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2379 * the copy of the page is to be made in normal memory, so the address of
2380 * the copy is returned.
2382 * If @buffer is returned, the caller of suspend_write_next() will write
2383 * the page's contents to @buffer, so they will have to be copied to the
2384 * right location on the next call to suspend_write_next() and it is done
2385 * with the help of copy_last_highmem_page(). For this purpose, if
2386 * @buffer is returned, @last_highmem_page is set to the page to which
2387 * the data will have to be copied from @buffer.
2389 static void *get_highmem_page_buffer(struct page *page,
2390 struct chain_allocator *ca)
2392 struct highmem_pbe *pbe;
2395 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2397 * We have allocated the "original" page frame and we can
2398 * use it directly to store the loaded page.
2400 last_highmem_page = page;
2404 * The "original" page frame has not been allocated and we have to
2405 * use a "safe" page frame to store the loaded page.
2407 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2410 return ERR_PTR(-ENOMEM);
2412 pbe->orig_page = page;
2413 if (safe_highmem_pages > 0) {
2416 /* Copy of the page will be stored in high memory */
2418 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2419 safe_highmem_pages--;
2420 last_highmem_page = tmp;
2421 pbe->copy_page = tmp;
2423 /* Copy of the page will be stored in normal memory */
2424 kaddr = safe_pages_list;
2425 safe_pages_list = safe_pages_list->next;
2426 pbe->copy_page = virt_to_page(kaddr);
2428 pbe->next = highmem_pblist;
2429 highmem_pblist = pbe;
2434 * copy_last_highmem_page - Copy most the most recent highmem image page.
2436 * Copy the contents of a highmem image from @buffer, where the caller of
2437 * snapshot_write_next() has stored them, to the right location represented by
2438 * @last_highmem_page .
2440 static void copy_last_highmem_page(void)
2442 if (last_highmem_page) {
2445 dst = kmap_atomic(last_highmem_page);
2446 copy_page(dst, buffer);
2448 last_highmem_page = NULL;
2452 static inline int last_highmem_page_copied(void)
2454 return !last_highmem_page;
2457 static inline void free_highmem_data(void)
2459 if (safe_highmem_bm)
2460 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2463 free_image_page(buffer, PG_UNSAFE_CLEAR);
2466 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2468 static inline int prepare_highmem_image(struct memory_bitmap *bm,
2469 unsigned int *nr_highmem_p) { return 0; }
2471 static inline void *get_highmem_page_buffer(struct page *page,
2472 struct chain_allocator *ca)
2474 return ERR_PTR(-EINVAL);
2477 static inline void copy_last_highmem_page(void) {}
2478 static inline int last_highmem_page_copied(void) { return 1; }
2479 static inline void free_highmem_data(void) {}
2480 #endif /* CONFIG_HIGHMEM */
2482 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2485 * prepare_image - Make room for loading hibernation image.
2486 * @new_bm: Unitialized memory bitmap structure.
2487 * @bm: Memory bitmap with unsafe pages marked.
2489 * Use @bm to mark the pages that will be overwritten in the process of
2490 * restoring the system memory state from the suspend image ("unsafe" pages)
2491 * and allocate memory for the image.
2493 * The idea is to allocate a new memory bitmap first and then allocate
2494 * as many pages as needed for image data, but without specifying what those
2495 * pages will be used for just yet. Instead, we mark them all as allocated and
2496 * create a lists of "safe" pages to be used later. On systems with high
2497 * memory a list of "safe" highmem pages is created too.
2499 static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2501 unsigned int nr_pages, nr_highmem;
2502 struct linked_page *lp;
2505 /* If there is no highmem, the buffer will not be necessary */
2506 free_image_page(buffer, PG_UNSAFE_CLEAR);
2509 nr_highmem = count_highmem_image_pages(bm);
2510 mark_unsafe_pages(bm);
2512 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2516 duplicate_memory_bitmap(new_bm, bm);
2517 memory_bm_free(bm, PG_UNSAFE_KEEP);
2518 if (nr_highmem > 0) {
2519 error = prepare_highmem_image(bm, &nr_highmem);
2524 * Reserve some safe pages for potential later use.
2526 * NOTE: This way we make sure there will be enough safe pages for the
2527 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2528 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2530 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2532 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2533 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2534 while (nr_pages > 0) {
2535 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2540 lp->next = safe_pages_list;
2541 safe_pages_list = lp;
2544 /* Preallocate memory for the image */
2545 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2546 while (nr_pages > 0) {
2547 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2552 if (!swsusp_page_is_free(virt_to_page(lp))) {
2553 /* The page is "safe", add it to the list */
2554 lp->next = safe_pages_list;
2555 safe_pages_list = lp;
2557 /* Mark the page as allocated */
2558 swsusp_set_page_forbidden(virt_to_page(lp));
2559 swsusp_set_page_free(virt_to_page(lp));
2570 * get_buffer - Get the address to store the next image data page.
2572 * Get the address that snapshot_write_next() should return to its caller to
2575 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2579 unsigned long pfn = memory_bm_next_pfn(bm);
2581 if (pfn == BM_END_OF_MAP)
2582 return ERR_PTR(-EFAULT);
2584 page = pfn_to_page(pfn);
2585 if (PageHighMem(page))
2586 return get_highmem_page_buffer(page, ca);
2588 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2590 * We have allocated the "original" page frame and we can
2591 * use it directly to store the loaded page.
2593 return page_address(page);
2596 * The "original" page frame has not been allocated and we have to
2597 * use a "safe" page frame to store the loaded page.
2599 pbe = chain_alloc(ca, sizeof(struct pbe));
2602 return ERR_PTR(-ENOMEM);
2604 pbe->orig_address = page_address(page);
2605 pbe->address = safe_pages_list;
2606 safe_pages_list = safe_pages_list->next;
2607 pbe->next = restore_pblist;
2608 restore_pblist = pbe;
2609 return pbe->address;
2613 * snapshot_write_next - Get the address to store the next image page.
2614 * @handle: Snapshot handle structure to guide the writing.
2616 * On the first call, @handle should point to a zeroed snapshot_handle
2617 * structure. The structure gets populated then and a pointer to it should be
2618 * passed to this function every next time.
2620 * On success, the function returns a positive number. Then, the caller
2621 * is allowed to write up to the returned number of bytes to the memory
2622 * location computed by the data_of() macro.
2624 * The function returns 0 to indicate the "end of file" condition. Negative
2625 * numbers are returned on errors, in which cases the structure pointed to by
2626 * @handle is not updated and should not be used any more.
2628 int snapshot_write_next(struct snapshot_handle *handle)
2630 static struct chain_allocator ca;
2633 /* Check if we have already loaded the entire image */
2634 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2637 handle->sync_read = 1;
2641 /* This makes the buffer be freed by swsusp_free() */
2642 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2647 handle->buffer = buffer;
2648 } else if (handle->cur == 1) {
2649 error = load_header(buffer);
2653 safe_pages_list = NULL;
2655 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2659 hibernate_restore_protection_begin();
2660 } else if (handle->cur <= nr_meta_pages + 1) {
2661 error = unpack_orig_pfns(buffer, ©_bm);
2665 if (handle->cur == nr_meta_pages + 1) {
2666 error = prepare_image(&orig_bm, ©_bm);
2670 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2671 memory_bm_position_reset(&orig_bm);
2672 restore_pblist = NULL;
2673 handle->buffer = get_buffer(&orig_bm, &ca);
2674 handle->sync_read = 0;
2675 if (IS_ERR(handle->buffer))
2676 return PTR_ERR(handle->buffer);
2679 copy_last_highmem_page();
2680 hibernate_restore_protect_page(handle->buffer);
2681 handle->buffer = get_buffer(&orig_bm, &ca);
2682 if (IS_ERR(handle->buffer))
2683 return PTR_ERR(handle->buffer);
2684 if (handle->buffer != buffer)
2685 handle->sync_read = 0;
2692 * snapshot_write_finalize - Complete the loading of a hibernation image.
2694 * Must be called after the last call to snapshot_write_next() in case the last
2695 * page in the image happens to be a highmem page and its contents should be
2696 * stored in highmem. Additionally, it recycles bitmap memory that's not
2697 * necessary any more.
2699 void snapshot_write_finalize(struct snapshot_handle *handle)
2701 copy_last_highmem_page();
2702 hibernate_restore_protect_page(handle->buffer);
2703 /* Do that only if we have loaded the image entirely */
2704 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2705 memory_bm_recycle(&orig_bm);
2706 free_highmem_data();
2710 int snapshot_image_loaded(struct snapshot_handle *handle)
2712 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2713 handle->cur <= nr_meta_pages + nr_copy_pages);
2716 #ifdef CONFIG_HIGHMEM
2717 /* Assumes that @buf is ready and points to a "safe" page */
2718 static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2721 void *kaddr1, *kaddr2;
2723 kaddr1 = kmap_atomic(p1);
2724 kaddr2 = kmap_atomic(p2);
2725 copy_page(buf, kaddr1);
2726 copy_page(kaddr1, kaddr2);
2727 copy_page(kaddr2, buf);
2728 kunmap_atomic(kaddr2);
2729 kunmap_atomic(kaddr1);
2733 * restore_highmem - Put highmem image pages into their original locations.
2735 * For each highmem page that was in use before hibernation and is included in
2736 * the image, and also has been allocated by the "restore" kernel, swap its
2737 * current contents with the previous (ie. "before hibernation") ones.
2739 * If the restore eventually fails, we can call this function once again and
2740 * restore the highmem state as seen by the restore kernel.
2742 int restore_highmem(void)
2744 struct highmem_pbe *pbe = highmem_pblist;
2750 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2755 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2758 free_image_page(buf, PG_UNSAFE_CLEAR);
2761 #endif /* CONFIG_HIGHMEM */