intel-iommu: Fix one last ia64 build problem in Pass Through Support
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / power / snapshot.c
blob33e2e4a819f97014a6e70e5f06d52e246ba783b3
1 /*
2 * linux/kernel/power/snapshot.c
4 * This file provides system snapshot/restore functionality for swsusp.
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * This file is released under the GPLv2.
13 #include <linux/version.h>
14 #include <linux/module.h>
15 #include <linux/mm.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>
21 #include <linux/pm.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>
30 #include <asm/uaccess.h>
31 #include <asm/mmu_context.h>
32 #include <asm/pgtable.h>
33 #include <asm/tlbflush.h>
34 #include <asm/io.h>
36 #include "power.h"
38 static int swsusp_page_is_free(struct page *);
39 static void swsusp_set_page_forbidden(struct page *);
40 static void swsusp_unset_page_forbidden(struct page *);
42 /* List of PBEs needed for restoring the pages that were allocated before
43 * the suspend and included in the suspend image, but have also been
44 * allocated by the "resume" kernel, so their contents cannot be written
45 * directly to their "original" page frames.
47 struct pbe *restore_pblist;
49 /* Pointer to an auxiliary buffer (1 page) */
50 static void *buffer;
52 /**
53 * @safe_needed - on resume, for storing the PBE list and the image,
54 * we can only use memory pages that do not conflict with the pages
55 * used before suspend. The unsafe pages have PageNosaveFree set
56 * and we count them using unsafe_pages.
58 * Each allocated image page is marked as PageNosave and PageNosaveFree
59 * so that swsusp_free() can release it.
62 #define PG_ANY 0
63 #define PG_SAFE 1
64 #define PG_UNSAFE_CLEAR 1
65 #define PG_UNSAFE_KEEP 0
67 static unsigned int allocated_unsafe_pages;
69 static void *get_image_page(gfp_t gfp_mask, int safe_needed)
71 void *res;
73 res = (void *)get_zeroed_page(gfp_mask);
74 if (safe_needed)
75 while (res && swsusp_page_is_free(virt_to_page(res))) {
76 /* The page is unsafe, mark it for swsusp_free() */
77 swsusp_set_page_forbidden(virt_to_page(res));
78 allocated_unsafe_pages++;
79 res = (void *)get_zeroed_page(gfp_mask);
81 if (res) {
82 swsusp_set_page_forbidden(virt_to_page(res));
83 swsusp_set_page_free(virt_to_page(res));
85 return res;
88 unsigned long get_safe_page(gfp_t gfp_mask)
90 return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
93 static struct page *alloc_image_page(gfp_t gfp_mask)
95 struct page *page;
97 page = alloc_page(gfp_mask);
98 if (page) {
99 swsusp_set_page_forbidden(page);
100 swsusp_set_page_free(page);
102 return page;
106 * free_image_page - free page represented by @addr, allocated with
107 * get_image_page (page flags set by it must be cleared)
110 static inline void free_image_page(void *addr, int clear_nosave_free)
112 struct page *page;
114 BUG_ON(!virt_addr_valid(addr));
116 page = virt_to_page(addr);
118 swsusp_unset_page_forbidden(page);
119 if (clear_nosave_free)
120 swsusp_unset_page_free(page);
122 __free_page(page);
125 /* struct linked_page is used to build chains of pages */
127 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
129 struct linked_page {
130 struct linked_page *next;
131 char data[LINKED_PAGE_DATA_SIZE];
132 } __attribute__((packed));
134 static inline void
135 free_list_of_pages(struct linked_page *list, int clear_page_nosave)
137 while (list) {
138 struct linked_page *lp = list->next;
140 free_image_page(list, clear_page_nosave);
141 list = lp;
146 * struct chain_allocator is used for allocating small objects out of
147 * a linked list of pages called 'the chain'.
149 * The chain grows each time when there is no room for a new object in
150 * the current page. The allocated objects cannot be freed individually.
151 * It is only possible to free them all at once, by freeing the entire
152 * chain.
154 * NOTE: The chain allocator may be inefficient if the allocated objects
155 * are not much smaller than PAGE_SIZE.
158 struct chain_allocator {
159 struct linked_page *chain; /* the chain */
160 unsigned int used_space; /* total size of objects allocated out
161 * of the current page
163 gfp_t gfp_mask; /* mask for allocating pages */
164 int safe_needed; /* if set, only "safe" pages are allocated */
167 static void
168 chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
170 ca->chain = NULL;
171 ca->used_space = LINKED_PAGE_DATA_SIZE;
172 ca->gfp_mask = gfp_mask;
173 ca->safe_needed = safe_needed;
176 static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
178 void *ret;
180 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
181 struct linked_page *lp;
183 lp = get_image_page(ca->gfp_mask, ca->safe_needed);
184 if (!lp)
185 return NULL;
187 lp->next = ca->chain;
188 ca->chain = lp;
189 ca->used_space = 0;
191 ret = ca->chain->data + ca->used_space;
192 ca->used_space += size;
193 return ret;
197 * Data types related to memory bitmaps.
199 * Memory bitmap is a structure consiting of many linked lists of
200 * objects. The main list's elements are of type struct zone_bitmap
201 * and each of them corresonds to one zone. For each zone bitmap
202 * object there is a list of objects of type struct bm_block that
203 * represent each blocks of bitmap in which information is stored.
205 * struct memory_bitmap contains a pointer to the main list of zone
206 * bitmap objects, a struct bm_position used for browsing the bitmap,
207 * and a pointer to the list of pages used for allocating all of the
208 * zone bitmap objects and bitmap block objects.
210 * NOTE: It has to be possible to lay out the bitmap in memory
211 * using only allocations of order 0. Additionally, the bitmap is
212 * designed to work with arbitrary number of zones (this is over the
213 * top for now, but let's avoid making unnecessary assumptions ;-).
215 * struct zone_bitmap contains a pointer to a list of bitmap block
216 * objects and a pointer to the bitmap block object that has been
217 * most recently used for setting bits. Additionally, it contains the
218 * pfns that correspond to the start and end of the represented zone.
220 * struct bm_block contains a pointer to the memory page in which
221 * information is stored (in the form of a block of bitmap)
222 * It also contains the pfns that correspond to the start and end of
223 * the represented memory area.
226 #define BM_END_OF_MAP (~0UL)
228 #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3)
230 struct bm_block {
231 struct list_head hook; /* hook into a list of bitmap blocks */
232 unsigned long start_pfn; /* pfn represented by the first bit */
233 unsigned long end_pfn; /* pfn represented by the last bit plus 1 */
234 unsigned long *data; /* bitmap representing pages */
237 static inline unsigned long bm_block_bits(struct bm_block *bb)
239 return bb->end_pfn - bb->start_pfn;
242 /* strcut bm_position is used for browsing memory bitmaps */
244 struct bm_position {
245 struct bm_block *block;
246 int bit;
249 struct memory_bitmap {
250 struct list_head blocks; /* list of bitmap blocks */
251 struct linked_page *p_list; /* list of pages used to store zone
252 * bitmap objects and bitmap block
253 * objects
255 struct bm_position cur; /* most recently used bit position */
258 /* Functions that operate on memory bitmaps */
260 static void memory_bm_position_reset(struct memory_bitmap *bm)
262 bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook);
263 bm->cur.bit = 0;
266 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
269 * create_bm_block_list - create a list of block bitmap objects
270 * @nr_blocks - number of blocks to allocate
271 * @list - list to put the allocated blocks into
272 * @ca - chain allocator to be used for allocating memory
274 static int create_bm_block_list(unsigned long pages,
275 struct list_head *list,
276 struct chain_allocator *ca)
278 unsigned int nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
280 while (nr_blocks-- > 0) {
281 struct bm_block *bb;
283 bb = chain_alloc(ca, sizeof(struct bm_block));
284 if (!bb)
285 return -ENOMEM;
286 list_add(&bb->hook, list);
289 return 0;
292 struct mem_extent {
293 struct list_head hook;
294 unsigned long start;
295 unsigned long end;
299 * free_mem_extents - free a list of memory extents
300 * @list - list of extents to empty
302 static void free_mem_extents(struct list_head *list)
304 struct mem_extent *ext, *aux;
306 list_for_each_entry_safe(ext, aux, list, hook) {
307 list_del(&ext->hook);
308 kfree(ext);
313 * create_mem_extents - create a list of memory extents representing
314 * contiguous ranges of PFNs
315 * @list - list to put the extents into
316 * @gfp_mask - mask to use for memory allocations
318 static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
320 struct zone *zone;
322 INIT_LIST_HEAD(list);
324 for_each_populated_zone(zone) {
325 unsigned long zone_start, zone_end;
326 struct mem_extent *ext, *cur, *aux;
328 zone_start = zone->zone_start_pfn;
329 zone_end = zone->zone_start_pfn + zone->spanned_pages;
331 list_for_each_entry(ext, list, hook)
332 if (zone_start <= ext->end)
333 break;
335 if (&ext->hook == list || zone_end < ext->start) {
336 /* New extent is necessary */
337 struct mem_extent *new_ext;
339 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
340 if (!new_ext) {
341 free_mem_extents(list);
342 return -ENOMEM;
344 new_ext->start = zone_start;
345 new_ext->end = zone_end;
346 list_add_tail(&new_ext->hook, &ext->hook);
347 continue;
350 /* Merge this zone's range of PFNs with the existing one */
351 if (zone_start < ext->start)
352 ext->start = zone_start;
353 if (zone_end > ext->end)
354 ext->end = zone_end;
356 /* More merging may be possible */
357 cur = ext;
358 list_for_each_entry_safe_continue(cur, aux, list, hook) {
359 if (zone_end < cur->start)
360 break;
361 if (zone_end < cur->end)
362 ext->end = cur->end;
363 list_del(&cur->hook);
364 kfree(cur);
368 return 0;
372 * memory_bm_create - allocate memory for a memory bitmap
374 static int
375 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
377 struct chain_allocator ca;
378 struct list_head mem_extents;
379 struct mem_extent *ext;
380 int error;
382 chain_init(&ca, gfp_mask, safe_needed);
383 INIT_LIST_HEAD(&bm->blocks);
385 error = create_mem_extents(&mem_extents, gfp_mask);
386 if (error)
387 return error;
389 list_for_each_entry(ext, &mem_extents, hook) {
390 struct bm_block *bb;
391 unsigned long pfn = ext->start;
392 unsigned long pages = ext->end - ext->start;
394 bb = list_entry(bm->blocks.prev, struct bm_block, hook);
396 error = create_bm_block_list(pages, bm->blocks.prev, &ca);
397 if (error)
398 goto Error;
400 list_for_each_entry_continue(bb, &bm->blocks, hook) {
401 bb->data = get_image_page(gfp_mask, safe_needed);
402 if (!bb->data) {
403 error = -ENOMEM;
404 goto Error;
407 bb->start_pfn = pfn;
408 if (pages >= BM_BITS_PER_BLOCK) {
409 pfn += BM_BITS_PER_BLOCK;
410 pages -= BM_BITS_PER_BLOCK;
411 } else {
412 /* This is executed only once in the loop */
413 pfn += pages;
415 bb->end_pfn = pfn;
419 bm->p_list = ca.chain;
420 memory_bm_position_reset(bm);
421 Exit:
422 free_mem_extents(&mem_extents);
423 return error;
425 Error:
426 bm->p_list = ca.chain;
427 memory_bm_free(bm, PG_UNSAFE_CLEAR);
428 goto Exit;
432 * memory_bm_free - free memory occupied by the memory bitmap @bm
434 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
436 struct bm_block *bb;
438 list_for_each_entry(bb, &bm->blocks, hook)
439 if (bb->data)
440 free_image_page(bb->data, clear_nosave_free);
442 free_list_of_pages(bm->p_list, clear_nosave_free);
444 INIT_LIST_HEAD(&bm->blocks);
448 * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
449 * to given pfn. The cur_zone_bm member of @bm and the cur_block member
450 * of @bm->cur_zone_bm are updated.
452 static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
453 void **addr, unsigned int *bit_nr)
455 struct bm_block *bb;
458 * Check if the pfn corresponds to the current bitmap block and find
459 * the block where it fits if this is not the case.
461 bb = bm->cur.block;
462 if (pfn < bb->start_pfn)
463 list_for_each_entry_continue_reverse(bb, &bm->blocks, hook)
464 if (pfn >= bb->start_pfn)
465 break;
467 if (pfn >= bb->end_pfn)
468 list_for_each_entry_continue(bb, &bm->blocks, hook)
469 if (pfn >= bb->start_pfn && pfn < bb->end_pfn)
470 break;
472 if (&bb->hook == &bm->blocks)
473 return -EFAULT;
475 /* The block has been found */
476 bm->cur.block = bb;
477 pfn -= bb->start_pfn;
478 bm->cur.bit = pfn + 1;
479 *bit_nr = pfn;
480 *addr = bb->data;
481 return 0;
484 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
486 void *addr;
487 unsigned int bit;
488 int error;
490 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
491 BUG_ON(error);
492 set_bit(bit, addr);
495 static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
497 void *addr;
498 unsigned int bit;
499 int error;
501 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
502 if (!error)
503 set_bit(bit, addr);
504 return error;
507 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
509 void *addr;
510 unsigned int bit;
511 int error;
513 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
514 BUG_ON(error);
515 clear_bit(bit, addr);
518 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
520 void *addr;
521 unsigned int bit;
522 int error;
524 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
525 BUG_ON(error);
526 return test_bit(bit, addr);
529 static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
531 void *addr;
532 unsigned int bit;
534 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
538 * memory_bm_next_pfn - find the pfn that corresponds to the next set bit
539 * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
540 * returned.
542 * It is required to run memory_bm_position_reset() before the first call to
543 * this function.
546 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
548 struct bm_block *bb;
549 int bit;
551 bb = bm->cur.block;
552 do {
553 bit = bm->cur.bit;
554 bit = find_next_bit(bb->data, bm_block_bits(bb), bit);
555 if (bit < bm_block_bits(bb))
556 goto Return_pfn;
558 bb = list_entry(bb->hook.next, struct bm_block, hook);
559 bm->cur.block = bb;
560 bm->cur.bit = 0;
561 } while (&bb->hook != &bm->blocks);
563 memory_bm_position_reset(bm);
564 return BM_END_OF_MAP;
566 Return_pfn:
567 bm->cur.bit = bit + 1;
568 return bb->start_pfn + bit;
572 * This structure represents a range of page frames the contents of which
573 * should not be saved during the suspend.
576 struct nosave_region {
577 struct list_head list;
578 unsigned long start_pfn;
579 unsigned long end_pfn;
582 static LIST_HEAD(nosave_regions);
585 * register_nosave_region - register a range of page frames the contents
586 * of which should not be saved during the suspend (to be used in the early
587 * initialization code)
590 void __init
591 __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
592 int use_kmalloc)
594 struct nosave_region *region;
596 if (start_pfn >= end_pfn)
597 return;
599 if (!list_empty(&nosave_regions)) {
600 /* Try to extend the previous region (they should be sorted) */
601 region = list_entry(nosave_regions.prev,
602 struct nosave_region, list);
603 if (region->end_pfn == start_pfn) {
604 region->end_pfn = end_pfn;
605 goto Report;
608 if (use_kmalloc) {
609 /* during init, this shouldn't fail */
610 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
611 BUG_ON(!region);
612 } else
613 /* This allocation cannot fail */
614 region = alloc_bootmem_low(sizeof(struct nosave_region));
615 region->start_pfn = start_pfn;
616 region->end_pfn = end_pfn;
617 list_add_tail(&region->list, &nosave_regions);
618 Report:
619 printk(KERN_INFO "PM: Registered nosave memory: %016lx - %016lx\n",
620 start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
624 * Set bits in this map correspond to the page frames the contents of which
625 * should not be saved during the suspend.
627 static struct memory_bitmap *forbidden_pages_map;
629 /* Set bits in this map correspond to free page frames. */
630 static struct memory_bitmap *free_pages_map;
633 * Each page frame allocated for creating the image is marked by setting the
634 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
637 void swsusp_set_page_free(struct page *page)
639 if (free_pages_map)
640 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
643 static int swsusp_page_is_free(struct page *page)
645 return free_pages_map ?
646 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
649 void swsusp_unset_page_free(struct page *page)
651 if (free_pages_map)
652 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
655 static void swsusp_set_page_forbidden(struct page *page)
657 if (forbidden_pages_map)
658 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
661 int swsusp_page_is_forbidden(struct page *page)
663 return forbidden_pages_map ?
664 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
667 static void swsusp_unset_page_forbidden(struct page *page)
669 if (forbidden_pages_map)
670 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
674 * mark_nosave_pages - set bits corresponding to the page frames the
675 * contents of which should not be saved in a given bitmap.
678 static void mark_nosave_pages(struct memory_bitmap *bm)
680 struct nosave_region *region;
682 if (list_empty(&nosave_regions))
683 return;
685 list_for_each_entry(region, &nosave_regions, list) {
686 unsigned long pfn;
688 pr_debug("PM: Marking nosave pages: %016lx - %016lx\n",
689 region->start_pfn << PAGE_SHIFT,
690 region->end_pfn << PAGE_SHIFT);
692 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
693 if (pfn_valid(pfn)) {
695 * It is safe to ignore the result of
696 * mem_bm_set_bit_check() here, since we won't
697 * touch the PFNs for which the error is
698 * returned anyway.
700 mem_bm_set_bit_check(bm, pfn);
706 * create_basic_memory_bitmaps - create bitmaps needed for marking page
707 * frames that should not be saved and free page frames. The pointers
708 * forbidden_pages_map and free_pages_map are only modified if everything
709 * goes well, because we don't want the bits to be used before both bitmaps
710 * are set up.
713 int create_basic_memory_bitmaps(void)
715 struct memory_bitmap *bm1, *bm2;
716 int error = 0;
718 BUG_ON(forbidden_pages_map || free_pages_map);
720 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
721 if (!bm1)
722 return -ENOMEM;
724 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
725 if (error)
726 goto Free_first_object;
728 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
729 if (!bm2)
730 goto Free_first_bitmap;
732 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
733 if (error)
734 goto Free_second_object;
736 forbidden_pages_map = bm1;
737 free_pages_map = bm2;
738 mark_nosave_pages(forbidden_pages_map);
740 pr_debug("PM: Basic memory bitmaps created\n");
742 return 0;
744 Free_second_object:
745 kfree(bm2);
746 Free_first_bitmap:
747 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
748 Free_first_object:
749 kfree(bm1);
750 return -ENOMEM;
754 * free_basic_memory_bitmaps - free memory bitmaps allocated by
755 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
756 * so that the bitmaps themselves are not referred to while they are being
757 * freed.
760 void free_basic_memory_bitmaps(void)
762 struct memory_bitmap *bm1, *bm2;
764 BUG_ON(!(forbidden_pages_map && free_pages_map));
766 bm1 = forbidden_pages_map;
767 bm2 = free_pages_map;
768 forbidden_pages_map = NULL;
769 free_pages_map = NULL;
770 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
771 kfree(bm1);
772 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
773 kfree(bm2);
775 pr_debug("PM: Basic memory bitmaps freed\n");
779 * snapshot_additional_pages - estimate the number of additional pages
780 * be needed for setting up the suspend image data structures for given
781 * zone (usually the returned value is greater than the exact number)
784 unsigned int snapshot_additional_pages(struct zone *zone)
786 unsigned int res;
788 res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
789 res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
790 return 2 * res;
793 #ifdef CONFIG_HIGHMEM
795 * count_free_highmem_pages - compute the total number of free highmem
796 * pages, system-wide.
799 static unsigned int count_free_highmem_pages(void)
801 struct zone *zone;
802 unsigned int cnt = 0;
804 for_each_populated_zone(zone)
805 if (is_highmem(zone))
806 cnt += zone_page_state(zone, NR_FREE_PAGES);
808 return cnt;
812 * saveable_highmem_page - Determine whether a highmem page should be
813 * included in the suspend image.
815 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
816 * and it isn't a part of a free chunk of pages.
818 static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
820 struct page *page;
822 if (!pfn_valid(pfn))
823 return NULL;
825 page = pfn_to_page(pfn);
826 if (page_zone(page) != zone)
827 return NULL;
829 BUG_ON(!PageHighMem(page));
831 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
832 PageReserved(page))
833 return NULL;
835 return page;
839 * count_highmem_pages - compute the total number of saveable highmem
840 * pages.
843 unsigned int count_highmem_pages(void)
845 struct zone *zone;
846 unsigned int n = 0;
848 for_each_zone(zone) {
849 unsigned long pfn, max_zone_pfn;
851 if (!is_highmem(zone))
852 continue;
854 mark_free_pages(zone);
855 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
856 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
857 if (saveable_highmem_page(zone, pfn))
858 n++;
860 return n;
862 #else
863 static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
865 return NULL;
867 #endif /* CONFIG_HIGHMEM */
870 * saveable_page - Determine whether a non-highmem page should be included
871 * in the suspend image.
873 * We should save the page if it isn't Nosave, and is not in the range
874 * of pages statically defined as 'unsaveable', and it isn't a part of
875 * a free chunk of pages.
877 static struct page *saveable_page(struct zone *zone, unsigned long pfn)
879 struct page *page;
881 if (!pfn_valid(pfn))
882 return NULL;
884 page = pfn_to_page(pfn);
885 if (page_zone(page) != zone)
886 return NULL;
888 BUG_ON(PageHighMem(page));
890 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
891 return NULL;
893 if (PageReserved(page)
894 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
895 return NULL;
897 return page;
901 * count_data_pages - compute the total number of saveable non-highmem
902 * pages.
905 unsigned int count_data_pages(void)
907 struct zone *zone;
908 unsigned long pfn, max_zone_pfn;
909 unsigned int n = 0;
911 for_each_zone(zone) {
912 if (is_highmem(zone))
913 continue;
915 mark_free_pages(zone);
916 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
917 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
918 if (saveable_page(zone, pfn))
919 n++;
921 return n;
924 /* This is needed, because copy_page and memcpy are not usable for copying
925 * task structs.
927 static inline void do_copy_page(long *dst, long *src)
929 int n;
931 for (n = PAGE_SIZE / sizeof(long); n; n--)
932 *dst++ = *src++;
937 * safe_copy_page - check if the page we are going to copy is marked as
938 * present in the kernel page tables (this always is the case if
939 * CONFIG_DEBUG_PAGEALLOC is not set and in that case
940 * kernel_page_present() always returns 'true').
942 static void safe_copy_page(void *dst, struct page *s_page)
944 if (kernel_page_present(s_page)) {
945 do_copy_page(dst, page_address(s_page));
946 } else {
947 kernel_map_pages(s_page, 1, 1);
948 do_copy_page(dst, page_address(s_page));
949 kernel_map_pages(s_page, 1, 0);
954 #ifdef CONFIG_HIGHMEM
955 static inline struct page *
956 page_is_saveable(struct zone *zone, unsigned long pfn)
958 return is_highmem(zone) ?
959 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
962 static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
964 struct page *s_page, *d_page;
965 void *src, *dst;
967 s_page = pfn_to_page(src_pfn);
968 d_page = pfn_to_page(dst_pfn);
969 if (PageHighMem(s_page)) {
970 src = kmap_atomic(s_page, KM_USER0);
971 dst = kmap_atomic(d_page, KM_USER1);
972 do_copy_page(dst, src);
973 kunmap_atomic(src, KM_USER0);
974 kunmap_atomic(dst, KM_USER1);
975 } else {
976 if (PageHighMem(d_page)) {
977 /* Page pointed to by src may contain some kernel
978 * data modified by kmap_atomic()
980 safe_copy_page(buffer, s_page);
981 dst = kmap_atomic(d_page, KM_USER0);
982 memcpy(dst, buffer, PAGE_SIZE);
983 kunmap_atomic(dst, KM_USER0);
984 } else {
985 safe_copy_page(page_address(d_page), s_page);
989 #else
990 #define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
992 static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
994 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
995 pfn_to_page(src_pfn));
997 #endif /* CONFIG_HIGHMEM */
999 static void
1000 copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
1002 struct zone *zone;
1003 unsigned long pfn;
1005 for_each_zone(zone) {
1006 unsigned long max_zone_pfn;
1008 mark_free_pages(zone);
1009 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1010 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1011 if (page_is_saveable(zone, pfn))
1012 memory_bm_set_bit(orig_bm, pfn);
1014 memory_bm_position_reset(orig_bm);
1015 memory_bm_position_reset(copy_bm);
1016 for(;;) {
1017 pfn = memory_bm_next_pfn(orig_bm);
1018 if (unlikely(pfn == BM_END_OF_MAP))
1019 break;
1020 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1024 /* Total number of image pages */
1025 static unsigned int nr_copy_pages;
1026 /* Number of pages needed for saving the original pfns of the image pages */
1027 static unsigned int nr_meta_pages;
1030 * swsusp_free - free pages allocated for the suspend.
1032 * Suspend pages are alocated before the atomic copy is made, so we
1033 * need to release them after the resume.
1036 void swsusp_free(void)
1038 struct zone *zone;
1039 unsigned long pfn, max_zone_pfn;
1041 for_each_zone(zone) {
1042 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1043 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1044 if (pfn_valid(pfn)) {
1045 struct page *page = pfn_to_page(pfn);
1047 if (swsusp_page_is_forbidden(page) &&
1048 swsusp_page_is_free(page)) {
1049 swsusp_unset_page_forbidden(page);
1050 swsusp_unset_page_free(page);
1051 __free_page(page);
1055 nr_copy_pages = 0;
1056 nr_meta_pages = 0;
1057 restore_pblist = NULL;
1058 buffer = NULL;
1061 #ifdef CONFIG_HIGHMEM
1063 * count_pages_for_highmem - compute the number of non-highmem pages
1064 * that will be necessary for creating copies of highmem pages.
1067 static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1069 unsigned int free_highmem = count_free_highmem_pages();
1071 if (free_highmem >= nr_highmem)
1072 nr_highmem = 0;
1073 else
1074 nr_highmem -= free_highmem;
1076 return nr_highmem;
1078 #else
1079 static unsigned int
1080 count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1081 #endif /* CONFIG_HIGHMEM */
1084 * enough_free_mem - Make sure we have enough free memory for the
1085 * snapshot image.
1088 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1090 struct zone *zone;
1091 unsigned int free = 0, meta = 0;
1093 for_each_zone(zone) {
1094 meta += snapshot_additional_pages(zone);
1095 if (!is_highmem(zone))
1096 free += zone_page_state(zone, NR_FREE_PAGES);
1099 nr_pages += count_pages_for_highmem(nr_highmem);
1100 pr_debug("PM: Normal pages needed: %u + %u + %u, available pages: %u\n",
1101 nr_pages, PAGES_FOR_IO, meta, free);
1103 return free > nr_pages + PAGES_FOR_IO + meta;
1106 #ifdef CONFIG_HIGHMEM
1108 * get_highmem_buffer - if there are some highmem pages in the suspend
1109 * image, we may need the buffer to copy them and/or load their data.
1112 static inline int get_highmem_buffer(int safe_needed)
1114 buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
1115 return buffer ? 0 : -ENOMEM;
1119 * alloc_highmem_image_pages - allocate some highmem pages for the image.
1120 * Try to allocate as many pages as needed, but if the number of free
1121 * highmem pages is lesser than that, allocate them all.
1124 static inline unsigned int
1125 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
1127 unsigned int to_alloc = count_free_highmem_pages();
1129 if (to_alloc > nr_highmem)
1130 to_alloc = nr_highmem;
1132 nr_highmem -= to_alloc;
1133 while (to_alloc-- > 0) {
1134 struct page *page;
1136 page = alloc_image_page(__GFP_HIGHMEM);
1137 memory_bm_set_bit(bm, page_to_pfn(page));
1139 return nr_highmem;
1141 #else
1142 static inline int get_highmem_buffer(int safe_needed) { return 0; }
1144 static inline unsigned int
1145 alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
1146 #endif /* CONFIG_HIGHMEM */
1149 * swsusp_alloc - allocate memory for the suspend image
1151 * We first try to allocate as many highmem pages as there are
1152 * saveable highmem pages in the system. If that fails, we allocate
1153 * non-highmem pages for the copies of the remaining highmem ones.
1155 * In this approach it is likely that the copies of highmem pages will
1156 * also be located in the high memory, because of the way in which
1157 * copy_data_pages() works.
1160 static int
1161 swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
1162 unsigned int nr_pages, unsigned int nr_highmem)
1164 int error;
1166 error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1167 if (error)
1168 goto Free;
1170 error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
1171 if (error)
1172 goto Free;
1174 if (nr_highmem > 0) {
1175 error = get_highmem_buffer(PG_ANY);
1176 if (error)
1177 goto Free;
1179 nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem);
1181 while (nr_pages-- > 0) {
1182 struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
1184 if (!page)
1185 goto Free;
1187 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1189 return 0;
1191 Free:
1192 swsusp_free();
1193 return -ENOMEM;
1196 /* Memory bitmap used for marking saveable pages (during suspend) or the
1197 * suspend image pages (during resume)
1199 static struct memory_bitmap orig_bm;
1200 /* Memory bitmap used on suspend for marking allocated pages that will contain
1201 * the copies of saveable pages. During resume it is initially used for
1202 * marking the suspend image pages, but then its set bits are duplicated in
1203 * @orig_bm and it is released. Next, on systems with high memory, it may be
1204 * used for marking "safe" highmem pages, but it has to be reinitialized for
1205 * this purpose.
1207 static struct memory_bitmap copy_bm;
1209 asmlinkage int swsusp_save(void)
1211 unsigned int nr_pages, nr_highmem;
1213 printk(KERN_INFO "PM: Creating hibernation image: \n");
1215 drain_local_pages(NULL);
1216 nr_pages = count_data_pages();
1217 nr_highmem = count_highmem_pages();
1218 printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem);
1220 if (!enough_free_mem(nr_pages, nr_highmem)) {
1221 printk(KERN_ERR "PM: Not enough free memory\n");
1222 return -ENOMEM;
1225 if (swsusp_alloc(&orig_bm, &copy_bm, nr_pages, nr_highmem)) {
1226 printk(KERN_ERR "PM: Memory allocation failed\n");
1227 return -ENOMEM;
1230 /* During allocating of suspend pagedir, new cold pages may appear.
1231 * Kill them.
1233 drain_local_pages(NULL);
1234 copy_data_pages(&copy_bm, &orig_bm);
1237 * End of critical section. From now on, we can write to memory,
1238 * but we should not touch disk. This specially means we must _not_
1239 * touch swap space! Except we must write out our image of course.
1242 nr_pages += nr_highmem;
1243 nr_copy_pages = nr_pages;
1244 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
1246 printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n",
1247 nr_pages);
1249 return 0;
1252 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
1253 static int init_header_complete(struct swsusp_info *info)
1255 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
1256 info->version_code = LINUX_VERSION_CODE;
1257 return 0;
1260 static char *check_image_kernel(struct swsusp_info *info)
1262 if (info->version_code != LINUX_VERSION_CODE)
1263 return "kernel version";
1264 if (strcmp(info->uts.sysname,init_utsname()->sysname))
1265 return "system type";
1266 if (strcmp(info->uts.release,init_utsname()->release))
1267 return "kernel release";
1268 if (strcmp(info->uts.version,init_utsname()->version))
1269 return "version";
1270 if (strcmp(info->uts.machine,init_utsname()->machine))
1271 return "machine";
1272 return NULL;
1274 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1276 unsigned long snapshot_get_image_size(void)
1278 return nr_copy_pages + nr_meta_pages + 1;
1281 static int init_header(struct swsusp_info *info)
1283 memset(info, 0, sizeof(struct swsusp_info));
1284 info->num_physpages = num_physpages;
1285 info->image_pages = nr_copy_pages;
1286 info->pages = snapshot_get_image_size();
1287 info->size = info->pages;
1288 info->size <<= PAGE_SHIFT;
1289 return init_header_complete(info);
1293 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1294 * are stored in the array @buf[] (1 page at a time)
1297 static inline void
1298 pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
1300 int j;
1302 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1303 buf[j] = memory_bm_next_pfn(bm);
1304 if (unlikely(buf[j] == BM_END_OF_MAP))
1305 break;
1310 * snapshot_read_next - used for reading the system memory snapshot.
1312 * On the first call to it @handle should point to a zeroed
1313 * snapshot_handle structure. The structure gets updated and a pointer
1314 * to it should be passed to this function every next time.
1316 * The @count parameter should contain the number of bytes the caller
1317 * wants to read from the snapshot. It must not be zero.
1319 * On success the function returns a positive number. Then, the caller
1320 * is allowed to read up to the returned number of bytes from the memory
1321 * location computed by the data_of() macro. The number returned
1322 * may be smaller than @count, but this only happens if the read would
1323 * cross a page boundary otherwise.
1325 * The function returns 0 to indicate the end of data stream condition,
1326 * and a negative number is returned on error. In such cases the
1327 * structure pointed to by @handle is not updated and should not be used
1328 * any more.
1331 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
1333 if (handle->cur > nr_meta_pages + nr_copy_pages)
1334 return 0;
1336 if (!buffer) {
1337 /* This makes the buffer be freed by swsusp_free() */
1338 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1339 if (!buffer)
1340 return -ENOMEM;
1342 if (!handle->offset) {
1343 int error;
1345 error = init_header((struct swsusp_info *)buffer);
1346 if (error)
1347 return error;
1348 handle->buffer = buffer;
1349 memory_bm_position_reset(&orig_bm);
1350 memory_bm_position_reset(&copy_bm);
1352 if (handle->prev < handle->cur) {
1353 if (handle->cur <= nr_meta_pages) {
1354 memset(buffer, 0, PAGE_SIZE);
1355 pack_pfns(buffer, &orig_bm);
1356 } else {
1357 struct page *page;
1359 page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
1360 if (PageHighMem(page)) {
1361 /* Highmem pages are copied to the buffer,
1362 * because we can't return with a kmapped
1363 * highmem page (we may not be called again).
1365 void *kaddr;
1367 kaddr = kmap_atomic(page, KM_USER0);
1368 memcpy(buffer, kaddr, PAGE_SIZE);
1369 kunmap_atomic(kaddr, KM_USER0);
1370 handle->buffer = buffer;
1371 } else {
1372 handle->buffer = page_address(page);
1375 handle->prev = handle->cur;
1377 handle->buf_offset = handle->cur_offset;
1378 if (handle->cur_offset + count >= PAGE_SIZE) {
1379 count = PAGE_SIZE - handle->cur_offset;
1380 handle->cur_offset = 0;
1381 handle->cur++;
1382 } else {
1383 handle->cur_offset += count;
1385 handle->offset += count;
1386 return count;
1390 * mark_unsafe_pages - mark the pages that cannot be used for storing
1391 * the image during resume, because they conflict with the pages that
1392 * had been used before suspend
1395 static int mark_unsafe_pages(struct memory_bitmap *bm)
1397 struct zone *zone;
1398 unsigned long pfn, max_zone_pfn;
1400 /* Clear page flags */
1401 for_each_zone(zone) {
1402 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1403 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1404 if (pfn_valid(pfn))
1405 swsusp_unset_page_free(pfn_to_page(pfn));
1408 /* Mark pages that correspond to the "original" pfns as "unsafe" */
1409 memory_bm_position_reset(bm);
1410 do {
1411 pfn = memory_bm_next_pfn(bm);
1412 if (likely(pfn != BM_END_OF_MAP)) {
1413 if (likely(pfn_valid(pfn)))
1414 swsusp_set_page_free(pfn_to_page(pfn));
1415 else
1416 return -EFAULT;
1418 } while (pfn != BM_END_OF_MAP);
1420 allocated_unsafe_pages = 0;
1422 return 0;
1425 static void
1426 duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
1428 unsigned long pfn;
1430 memory_bm_position_reset(src);
1431 pfn = memory_bm_next_pfn(src);
1432 while (pfn != BM_END_OF_MAP) {
1433 memory_bm_set_bit(dst, pfn);
1434 pfn = memory_bm_next_pfn(src);
1438 static int check_header(struct swsusp_info *info)
1440 char *reason;
1442 reason = check_image_kernel(info);
1443 if (!reason && info->num_physpages != num_physpages)
1444 reason = "memory size";
1445 if (reason) {
1446 printk(KERN_ERR "PM: Image mismatch: %s\n", reason);
1447 return -EPERM;
1449 return 0;
1453 * load header - check the image header and copy data from it
1456 static int
1457 load_header(struct swsusp_info *info)
1459 int error;
1461 restore_pblist = NULL;
1462 error = check_header(info);
1463 if (!error) {
1464 nr_copy_pages = info->image_pages;
1465 nr_meta_pages = info->pages - info->image_pages - 1;
1467 return error;
1471 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1472 * the corresponding bit in the memory bitmap @bm
1474 static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
1476 int j;
1478 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1479 if (unlikely(buf[j] == BM_END_OF_MAP))
1480 break;
1482 if (memory_bm_pfn_present(bm, buf[j]))
1483 memory_bm_set_bit(bm, buf[j]);
1484 else
1485 return -EFAULT;
1488 return 0;
1491 /* List of "safe" pages that may be used to store data loaded from the suspend
1492 * image
1494 static struct linked_page *safe_pages_list;
1496 #ifdef CONFIG_HIGHMEM
1497 /* struct highmem_pbe is used for creating the list of highmem pages that
1498 * should be restored atomically during the resume from disk, because the page
1499 * frames they have occupied before the suspend are in use.
1501 struct highmem_pbe {
1502 struct page *copy_page; /* data is here now */
1503 struct page *orig_page; /* data was here before the suspend */
1504 struct highmem_pbe *next;
1507 /* List of highmem PBEs needed for restoring the highmem pages that were
1508 * allocated before the suspend and included in the suspend image, but have
1509 * also been allocated by the "resume" kernel, so their contents cannot be
1510 * written directly to their "original" page frames.
1512 static struct highmem_pbe *highmem_pblist;
1515 * count_highmem_image_pages - compute the number of highmem pages in the
1516 * suspend image. The bits in the memory bitmap @bm that correspond to the
1517 * image pages are assumed to be set.
1520 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
1522 unsigned long pfn;
1523 unsigned int cnt = 0;
1525 memory_bm_position_reset(bm);
1526 pfn = memory_bm_next_pfn(bm);
1527 while (pfn != BM_END_OF_MAP) {
1528 if (PageHighMem(pfn_to_page(pfn)))
1529 cnt++;
1531 pfn = memory_bm_next_pfn(bm);
1533 return cnt;
1537 * prepare_highmem_image - try to allocate as many highmem pages as
1538 * there are highmem image pages (@nr_highmem_p points to the variable
1539 * containing the number of highmem image pages). The pages that are
1540 * "safe" (ie. will not be overwritten when the suspend image is
1541 * restored) have the corresponding bits set in @bm (it must be
1542 * unitialized).
1544 * NOTE: This function should not be called if there are no highmem
1545 * image pages.
1548 static unsigned int safe_highmem_pages;
1550 static struct memory_bitmap *safe_highmem_bm;
1552 static int
1553 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1555 unsigned int to_alloc;
1557 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
1558 return -ENOMEM;
1560 if (get_highmem_buffer(PG_SAFE))
1561 return -ENOMEM;
1563 to_alloc = count_free_highmem_pages();
1564 if (to_alloc > *nr_highmem_p)
1565 to_alloc = *nr_highmem_p;
1566 else
1567 *nr_highmem_p = to_alloc;
1569 safe_highmem_pages = 0;
1570 while (to_alloc-- > 0) {
1571 struct page *page;
1573 page = alloc_page(__GFP_HIGHMEM);
1574 if (!swsusp_page_is_free(page)) {
1575 /* The page is "safe", set its bit the bitmap */
1576 memory_bm_set_bit(bm, page_to_pfn(page));
1577 safe_highmem_pages++;
1579 /* Mark the page as allocated */
1580 swsusp_set_page_forbidden(page);
1581 swsusp_set_page_free(page);
1583 memory_bm_position_reset(bm);
1584 safe_highmem_bm = bm;
1585 return 0;
1589 * get_highmem_page_buffer - for given highmem image page find the buffer
1590 * that suspend_write_next() should set for its caller to write to.
1592 * If the page is to be saved to its "original" page frame or a copy of
1593 * the page is to be made in the highmem, @buffer is returned. Otherwise,
1594 * the copy of the page is to be made in normal memory, so the address of
1595 * the copy is returned.
1597 * If @buffer is returned, the caller of suspend_write_next() will write
1598 * the page's contents to @buffer, so they will have to be copied to the
1599 * right location on the next call to suspend_write_next() and it is done
1600 * with the help of copy_last_highmem_page(). For this purpose, if
1601 * @buffer is returned, @last_highmem page is set to the page to which
1602 * the data will have to be copied from @buffer.
1605 static struct page *last_highmem_page;
1607 static void *
1608 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1610 struct highmem_pbe *pbe;
1611 void *kaddr;
1613 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
1614 /* We have allocated the "original" page frame and we can
1615 * use it directly to store the loaded page.
1617 last_highmem_page = page;
1618 return buffer;
1620 /* The "original" page frame has not been allocated and we have to
1621 * use a "safe" page frame to store the loaded page.
1623 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
1624 if (!pbe) {
1625 swsusp_free();
1626 return ERR_PTR(-ENOMEM);
1628 pbe->orig_page = page;
1629 if (safe_highmem_pages > 0) {
1630 struct page *tmp;
1632 /* Copy of the page will be stored in high memory */
1633 kaddr = buffer;
1634 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
1635 safe_highmem_pages--;
1636 last_highmem_page = tmp;
1637 pbe->copy_page = tmp;
1638 } else {
1639 /* Copy of the page will be stored in normal memory */
1640 kaddr = safe_pages_list;
1641 safe_pages_list = safe_pages_list->next;
1642 pbe->copy_page = virt_to_page(kaddr);
1644 pbe->next = highmem_pblist;
1645 highmem_pblist = pbe;
1646 return kaddr;
1650 * copy_last_highmem_page - copy the contents of a highmem image from
1651 * @buffer, where the caller of snapshot_write_next() has place them,
1652 * to the right location represented by @last_highmem_page .
1655 static void copy_last_highmem_page(void)
1657 if (last_highmem_page) {
1658 void *dst;
1660 dst = kmap_atomic(last_highmem_page, KM_USER0);
1661 memcpy(dst, buffer, PAGE_SIZE);
1662 kunmap_atomic(dst, KM_USER0);
1663 last_highmem_page = NULL;
1667 static inline int last_highmem_page_copied(void)
1669 return !last_highmem_page;
1672 static inline void free_highmem_data(void)
1674 if (safe_highmem_bm)
1675 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
1677 if (buffer)
1678 free_image_page(buffer, PG_UNSAFE_CLEAR);
1680 #else
1681 static inline int get_safe_write_buffer(void) { return 0; }
1683 static unsigned int
1684 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
1686 static inline int
1687 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1689 return 0;
1692 static inline void *
1693 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1695 return ERR_PTR(-EINVAL);
1698 static inline void copy_last_highmem_page(void) {}
1699 static inline int last_highmem_page_copied(void) { return 1; }
1700 static inline void free_highmem_data(void) {}
1701 #endif /* CONFIG_HIGHMEM */
1704 * prepare_image - use the memory bitmap @bm to mark the pages that will
1705 * be overwritten in the process of restoring the system memory state
1706 * from the suspend image ("unsafe" pages) and allocate memory for the
1707 * image.
1709 * The idea is to allocate a new memory bitmap first and then allocate
1710 * as many pages as needed for the image data, but not to assign these
1711 * pages to specific tasks initially. Instead, we just mark them as
1712 * allocated and create a lists of "safe" pages that will be used
1713 * later. On systems with high memory a list of "safe" highmem pages is
1714 * also created.
1717 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
1719 static int
1720 prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
1722 unsigned int nr_pages, nr_highmem;
1723 struct linked_page *sp_list, *lp;
1724 int error;
1726 /* If there is no highmem, the buffer will not be necessary */
1727 free_image_page(buffer, PG_UNSAFE_CLEAR);
1728 buffer = NULL;
1730 nr_highmem = count_highmem_image_pages(bm);
1731 error = mark_unsafe_pages(bm);
1732 if (error)
1733 goto Free;
1735 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
1736 if (error)
1737 goto Free;
1739 duplicate_memory_bitmap(new_bm, bm);
1740 memory_bm_free(bm, PG_UNSAFE_KEEP);
1741 if (nr_highmem > 0) {
1742 error = prepare_highmem_image(bm, &nr_highmem);
1743 if (error)
1744 goto Free;
1746 /* Reserve some safe pages for potential later use.
1748 * NOTE: This way we make sure there will be enough safe pages for the
1749 * chain_alloc() in get_buffer(). It is a bit wasteful, but
1750 * nr_copy_pages cannot be greater than 50% of the memory anyway.
1752 sp_list = NULL;
1753 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
1754 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1755 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
1756 while (nr_pages > 0) {
1757 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
1758 if (!lp) {
1759 error = -ENOMEM;
1760 goto Free;
1762 lp->next = sp_list;
1763 sp_list = lp;
1764 nr_pages--;
1766 /* Preallocate memory for the image */
1767 safe_pages_list = NULL;
1768 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
1769 while (nr_pages > 0) {
1770 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
1771 if (!lp) {
1772 error = -ENOMEM;
1773 goto Free;
1775 if (!swsusp_page_is_free(virt_to_page(lp))) {
1776 /* The page is "safe", add it to the list */
1777 lp->next = safe_pages_list;
1778 safe_pages_list = lp;
1780 /* Mark the page as allocated */
1781 swsusp_set_page_forbidden(virt_to_page(lp));
1782 swsusp_set_page_free(virt_to_page(lp));
1783 nr_pages--;
1785 /* Free the reserved safe pages so that chain_alloc() can use them */
1786 while (sp_list) {
1787 lp = sp_list->next;
1788 free_image_page(sp_list, PG_UNSAFE_CLEAR);
1789 sp_list = lp;
1791 return 0;
1793 Free:
1794 swsusp_free();
1795 return error;
1799 * get_buffer - compute the address that snapshot_write_next() should
1800 * set for its caller to write to.
1803 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
1805 struct pbe *pbe;
1806 struct page *page;
1807 unsigned long pfn = memory_bm_next_pfn(bm);
1809 if (pfn == BM_END_OF_MAP)
1810 return ERR_PTR(-EFAULT);
1812 page = pfn_to_page(pfn);
1813 if (PageHighMem(page))
1814 return get_highmem_page_buffer(page, ca);
1816 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
1817 /* We have allocated the "original" page frame and we can
1818 * use it directly to store the loaded page.
1820 return page_address(page);
1822 /* The "original" page frame has not been allocated and we have to
1823 * use a "safe" page frame to store the loaded page.
1825 pbe = chain_alloc(ca, sizeof(struct pbe));
1826 if (!pbe) {
1827 swsusp_free();
1828 return ERR_PTR(-ENOMEM);
1830 pbe->orig_address = page_address(page);
1831 pbe->address = safe_pages_list;
1832 safe_pages_list = safe_pages_list->next;
1833 pbe->next = restore_pblist;
1834 restore_pblist = pbe;
1835 return pbe->address;
1839 * snapshot_write_next - used for writing the system memory snapshot.
1841 * On the first call to it @handle should point to a zeroed
1842 * snapshot_handle structure. The structure gets updated and a pointer
1843 * to it should be passed to this function every next time.
1845 * The @count parameter should contain the number of bytes the caller
1846 * wants to write to the image. It must not be zero.
1848 * On success the function returns a positive number. Then, the caller
1849 * is allowed to write up to the returned number of bytes to the memory
1850 * location computed by the data_of() macro. The number returned
1851 * may be smaller than @count, but this only happens if the write would
1852 * cross a page boundary otherwise.
1854 * The function returns 0 to indicate the "end of file" condition,
1855 * and a negative number is returned on error. In such cases the
1856 * structure pointed to by @handle is not updated and should not be used
1857 * any more.
1860 int snapshot_write_next(struct snapshot_handle *handle, size_t count)
1862 static struct chain_allocator ca;
1863 int error = 0;
1865 /* Check if we have already loaded the entire image */
1866 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
1867 return 0;
1869 if (handle->offset == 0) {
1870 if (!buffer)
1871 /* This makes the buffer be freed by swsusp_free() */
1872 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1874 if (!buffer)
1875 return -ENOMEM;
1877 handle->buffer = buffer;
1879 handle->sync_read = 1;
1880 if (handle->prev < handle->cur) {
1881 if (handle->prev == 0) {
1882 error = load_header(buffer);
1883 if (error)
1884 return error;
1886 error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
1887 if (error)
1888 return error;
1890 } else if (handle->prev <= nr_meta_pages) {
1891 error = unpack_orig_pfns(buffer, &copy_bm);
1892 if (error)
1893 return error;
1895 if (handle->prev == nr_meta_pages) {
1896 error = prepare_image(&orig_bm, &copy_bm);
1897 if (error)
1898 return error;
1900 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
1901 memory_bm_position_reset(&orig_bm);
1902 restore_pblist = NULL;
1903 handle->buffer = get_buffer(&orig_bm, &ca);
1904 handle->sync_read = 0;
1905 if (IS_ERR(handle->buffer))
1906 return PTR_ERR(handle->buffer);
1908 } else {
1909 copy_last_highmem_page();
1910 handle->buffer = get_buffer(&orig_bm, &ca);
1911 if (IS_ERR(handle->buffer))
1912 return PTR_ERR(handle->buffer);
1913 if (handle->buffer != buffer)
1914 handle->sync_read = 0;
1916 handle->prev = handle->cur;
1918 handle->buf_offset = handle->cur_offset;
1919 if (handle->cur_offset + count >= PAGE_SIZE) {
1920 count = PAGE_SIZE - handle->cur_offset;
1921 handle->cur_offset = 0;
1922 handle->cur++;
1923 } else {
1924 handle->cur_offset += count;
1926 handle->offset += count;
1927 return count;
1931 * snapshot_write_finalize - must be called after the last call to
1932 * snapshot_write_next() in case the last page in the image happens
1933 * to be a highmem page and its contents should be stored in the
1934 * highmem. Additionally, it releases the memory that will not be
1935 * used any more.
1938 void snapshot_write_finalize(struct snapshot_handle *handle)
1940 copy_last_highmem_page();
1941 /* Free only if we have loaded the image entirely */
1942 if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
1943 memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
1944 free_highmem_data();
1948 int snapshot_image_loaded(struct snapshot_handle *handle)
1950 return !(!nr_copy_pages || !last_highmem_page_copied() ||
1951 handle->cur <= nr_meta_pages + nr_copy_pages);
1954 #ifdef CONFIG_HIGHMEM
1955 /* Assumes that @buf is ready and points to a "safe" page */
1956 static inline void
1957 swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
1959 void *kaddr1, *kaddr2;
1961 kaddr1 = kmap_atomic(p1, KM_USER0);
1962 kaddr2 = kmap_atomic(p2, KM_USER1);
1963 memcpy(buf, kaddr1, PAGE_SIZE);
1964 memcpy(kaddr1, kaddr2, PAGE_SIZE);
1965 memcpy(kaddr2, buf, PAGE_SIZE);
1966 kunmap_atomic(kaddr1, KM_USER0);
1967 kunmap_atomic(kaddr2, KM_USER1);
1971 * restore_highmem - for each highmem page that was allocated before
1972 * the suspend and included in the suspend image, and also has been
1973 * allocated by the "resume" kernel swap its current (ie. "before
1974 * resume") contents with the previous (ie. "before suspend") one.
1976 * If the resume eventually fails, we can call this function once
1977 * again and restore the "before resume" highmem state.
1980 int restore_highmem(void)
1982 struct highmem_pbe *pbe = highmem_pblist;
1983 void *buf;
1985 if (!pbe)
1986 return 0;
1988 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
1989 if (!buf)
1990 return -ENOMEM;
1992 while (pbe) {
1993 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
1994 pbe = pbe->next;
1996 free_image_page(buf, PG_UNSAFE_CLEAR);
1997 return 0;
1999 #endif /* CONFIG_HIGHMEM */