/* * linux/kernel/power/snapshot.c * * This file provides system snapshot/restore functionality for swsusp. * * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz> * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> * * This file is released under the GPLv2. * */ #include <linux/version.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/suspend.h> #include <linux/delay.h> #include <linux/bitops.h> #include <linux/spinlock.h> #include <linux/kernel.h> #include <linux/pm.h> #include <linux/device.h> #include <linux/init.h> #include <linux/bootmem.h> #include <linux/syscalls.h> #include <linux/console.h> #include <linux/highmem.h> #include <asm/uaccess.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> #include <asm/io.h> #include "power.h" static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); /* List of PBEs needed for restoring the pages that were allocated before * the suspend and included in the suspend image, but have also been * allocated by the "resume" kernel, so their contents cannot be written * directly to their "original" page frames. */ struct pbe *restore_pblist; /* Pointer to an auxiliary buffer (1 page) */ static void *buffer; /** * @safe_needed - on resume, for storing the PBE list and the image, * we can only use memory pages that do not conflict with the pages * used before suspend. The unsafe pages have PageNosaveFree set * and we count them using unsafe_pages. * * Each allocated image page is marked as PageNosave and PageNosaveFree * so that swsusp_free() can release it. */ #define PG_ANY 0 #define PG_SAFE 1 #define PG_UNSAFE_CLEAR 1 #define PG_UNSAFE_KEEP 0 static unsigned int allocated_unsafe_pages; static void *get_image_page(gfp_t gfp_mask, int safe_needed) { void *res; res = (void *)get_zeroed_page(gfp_mask); if (safe_needed) while (res && swsusp_page_is_free(virt_to_page(res))) { /* The page is unsafe, mark it for swsusp_free() */ swsusp_set_page_forbidden(virt_to_page(res)); allocated_unsafe_pages++; res = (void *)get_zeroed_page(gfp_mask); } if (res) { swsusp_set_page_forbidden(virt_to_page(res)); swsusp_set_page_free(virt_to_page(res)); } return res; } unsigned long get_safe_page(gfp_t gfp_mask) { return (unsigned long)get_image_page(gfp_mask, PG_SAFE); } static struct page *alloc_image_page(gfp_t gfp_mask) { struct page *page; page = alloc_page(gfp_mask); if (page) { swsusp_set_page_forbidden(page); swsusp_set_page_free(page); } return page; } /** * free_image_page - free page represented by @addr, allocated with * get_image_page (page flags set by it must be cleared) */ static inline void free_image_page(void *addr, int clear_nosave_free) { struct page *page; BUG_ON(!virt_addr_valid(addr)); page = virt_to_page(addr); swsusp_unset_page_forbidden(page); if (clear_nosave_free) swsusp_unset_page_free(page); __free_page(page); } /* struct linked_page is used to build chains of pages */ #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) struct linked_page { struct linked_page *next; char data[LINKED_PAGE_DATA_SIZE]; } __attribute__((packed)); static inline void free_list_of_pages(struct linked_page *list, int clear_page_nosave) { while (list) { struct linked_page *lp = list->next; free_image_page(list, clear_page_nosave); list = lp; } } /** * struct chain_allocator is used for allocating small objects out of * a linked list of pages called 'the chain'. * * The chain grows each time when there is no room for a new object in * the current page. The allocated objects cannot be freed individually. * It is only possible to free them all at once, by freeing the entire * chain. * * NOTE: The chain allocator may be inefficient if the allocated objects * are not much smaller than PAGE_SIZE. */ struct chain_allocator { struct linked_page *chain; /* the chain */ unsigned int used_space; /* total size of objects allocated out * of the current page */ gfp_t gfp_mask; /* mask for allocating pages */ int safe_needed; /* if set, only "safe" pages are allocated */ }; static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed) { ca->chain = NULL; ca->used_space = LINKED_PAGE_DATA_SIZE; ca->gfp_mask = gfp_mask; ca->safe_needed = safe_needed; } static void *chain_alloc(struct chain_allocator *ca, unsigned int size) { void *ret; if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) { struct linked_page *lp; lp = get_image_page(ca->gfp_mask, ca->safe_needed); if (!lp) return NULL; lp->next = ca->chain; ca->chain = lp; ca->used_space = 0; } ret = ca->chain->data + ca->used_space; ca->used_space += size; return ret; } static void chain_free(struct chain_allocator *ca, int clear_page_nosave) { free_list_of_pages(ca->chain, clear_page_nosave); memset(ca, 0, sizeof(struct chain_allocator)); } /** * Data types related to memory bitmaps. * * Memory bitmap is a structure consiting of many linked lists of * objects. The main list's elements are of type struct zone_bitmap * and each of them corresonds to one zone. For each zone bitmap * object there is a list of objects of type struct bm_block that * represent each blocks of bit chunks in which information is * stored. * * struct memory_bitmap contains a pointer to the main list of zone * bitmap objects, a struct bm_position used for browsing the bitmap, * and a pointer to the list of pages used for allocating all of the * zone bitmap objects and bitmap block objects. * * NOTE: It has to be possible to lay out the bitmap in memory * using only allocations of order 0. Additionally, the bitmap is * designed to work with arbitrary number of zones (this is over the * top for now, but let's avoid making unnecessary assumptions ;-). * * struct zone_bitmap contains a pointer to a list of bitmap block * objects and a pointer to the bitmap block object that has been * most recently used for setting bits. Additionally, it contains the * pfns that correspond to the start and end of the represented zone. * * struct bm_block contains a pointer to the memory page in which * information is stored (in the form of a block of bit chunks * of type unsigned long each). It also contains the pfns that * correspond to the start and end of the represented memory area and * the number of bit chunks in the block. */ #define BM_END_OF_MAP (~0UL) #define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long)) #define BM_BITS_PER_CHUNK (sizeof(long) << 3) #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3) struct bm_block { struct bm_block *next; /* next element of the list */ unsigned long start_pfn; /* pfn represented by the first bit */ unsigned long end_pfn; /* pfn represented by the last bit plus 1 */ unsigned int size; /* number of bit chunks */ unsigned long *data; /* chunks of bits representing pages */ }; struct zone_bitmap { struct zone_bitmap *next; /* next element of the list */ unsigned long start_pfn; /* minimal pfn in this zone */ unsigned long end_pfn; /* maximal pfn in this zone plus 1 */ struct bm_block *bm_blocks; /* list of bitmap blocks */ struct bm_block *cur_block; /* recently used bitmap block */ }; /* strcut bm_position is used for browsing memory bitmaps */ struct bm_position { struct zone_bitmap *zone_bm; struct bm_block *block; int chunk; int bit; }; struct memory_bitmap { struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */ struct linked_page *p_list; /* list of pages used to store zone * bitmap objects and bitmap block * objects */ struct bm_position cur; /* most recently used bit position */ }; /* Functions that operate on memory bitmaps */ static inline void memory_bm_reset_chunk(struct memory_bitmap *bm) { bm->cur.chunk = 0; bm->cur.bit = -1; } static void memory_bm_position_reset(struct memory_bitmap *bm) { struct zone_bitmap *zone_bm; zone_bm = bm->zone_bm_list; bm->cur.zone_bm = zone_bm; bm->cur.block = zone_bm->bm_blocks; memory_bm_reset_chunk(bm); } static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); /** * create_bm_block_list - create a list of block bitmap objects */ static inline struct bm_block * create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca) { struct bm_block *bblist = NULL; while (nr_blocks-- > 0) { struct bm_block *bb; bb = chain_alloc(ca, sizeof(struct bm_block)); if (!bb) return NULL; bb->next = bblist; bblist = bb; } return bblist; } /** * create_zone_bm_list - create a list of zone bitmap objects */ static inline struct zone_bitmap * create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca) { struct zone_bitmap *zbmlist = NULL; while (nr_zones-- > 0) { struct zone_bitmap *zbm; zbm = chain_alloc(ca, sizeof(struct zone_bitmap)); if (!zbm) return NULL; zbm->next = zbmlist; zbmlist = zbm; } return zbmlist; } /** * memory_bm_create - allocate memory for a memory bitmap */ static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) { struct chain_allocator ca; struct zone *zone; struct zone_bitmap *zone_bm; struct bm_block *bb; unsigned int nr; chain_init(&ca, gfp_mask, safe_needed); /* Compute the number of zones */ nr = 0; for_each_zone(zone) if (populated_zone(zone)) nr++; /* Allocate the list of zones bitmap objects */ zone_bm = create_zone_bm_list(nr, &ca); bm->zone_bm_list = zone_bm; if (!zone_bm) { chain_free(&ca, PG_UNSAFE_CLEAR); return -ENOMEM; } /* Initialize the zone bitmap objects */ for_each_zone(zone) { unsigned long pfn; if (!populated_zone(zone)) continue; zone_bm->start_pfn = zone->zone_start_pfn; zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages; /* Allocate the list of bitmap block objects */ nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); bb = create_bm_block_list(nr, &ca); zone_bm->bm_blocks = bb; zone_bm->cur_block = bb; if (!bb) goto Free; nr = zone->spanned_pages; pfn = zone->zone_start_pfn; /* Initialize the bitmap block objects */ while (bb) { unsigned long *ptr; ptr = get_image_page(gfp_mask, safe_needed); bb->data = ptr; if (!ptr) goto Free; bb->start_pfn = pfn; if (nr >= BM_BITS_PER_BLOCK) { pfn += BM_BITS_PER_BLOCK; bb->size = BM_CHUNKS_PER_BLOCK; nr -= BM_BITS_PER_BLOCK; } else { /* This is executed only once in the loop */ pfn += nr; bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK); } bb->end_pfn = pfn; bb = bb->next; } zone_bm = zone_bm->next; } bm->p_list = ca.chain; memory_bm_position_reset(bm); return 0; Free: bm->p_list = ca.chain; memory_bm_free(bm, PG_UNSAFE_CLEAR); return -ENOMEM; } /** * memory_bm_free - free memory occupied by the memory bitmap @bm */ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) { struct zone_bitmap *zone_bm; /* Free the list of bit blocks for each zone_bitmap object */ zone_bm = bm->zone_bm_list; while (zone_bm) { struct bm_block *bb; bb = zone_bm->bm_blocks; while (bb) { if (bb->data) free_image_page(bb->data, clear_nosave_free); bb = bb->next; } zone_bm = zone_bm->next; } free_list_of_pages(bm->p_list, clear_nosave_free); bm->zone_bm_list = NULL; } /** * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds * to given pfn. The cur_zone_bm member of @bm and the cur_block member * of @bm->cur_zone_bm are updated. */ static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, void **addr, unsigned int *bit_nr) { struct zone_bitmap *zone_bm; struct bm_block *bb; /* Check if the pfn is from the current zone */ zone_bm = bm->cur.zone_bm; if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { zone_bm = bm->zone_bm_list; /* We don't assume that the zones are sorted by pfns */ while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { zone_bm = zone_bm->next; BUG_ON(!zone_bm); } bm->cur.zone_bm = zone_bm; } /* Check if the pfn corresponds to the current bitmap block */ bb = zone_bm->cur_block; if (pfn < bb->start_pfn) bb = zone_bm->bm_blocks; while (pfn >= bb->end_pfn) { bb = bb->next; BUG_ON(!bb); } zone_bm->cur_block = bb; pfn -= bb->start_pfn; *bit_nr = pfn % BM_BITS_PER_CHUNK; *addr = bb->data + pfn / BM_BITS_PER_CHUNK; } static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) { void *addr; unsigned int bit; memory_bm_find_bit(bm, pfn, &addr, &bit); set_bit(bit, addr); } static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) { void *addr; unsigned int bit; memory_bm_find_bit(bm, pfn, &addr, &bit); clear_bit(bit, addr); } static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) { void *addr; unsigned int bit; memory_bm_find_bit(bm, pfn, &addr, &bit); return test_bit(bit, addr); } /* Two auxiliary functions for memory_bm_next_pfn */ /* Find the first set bit in the given chunk, if there is one */ static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p) { bit++; while (bit < BM_BITS_PER_CHUNK) { if (test_bit(bit, chunk_p)) return bit; bit++; } return -1; } /* Find a chunk containing some bits set in given block of bits */ static inline int next_chunk_in_block(int n, struct bm_block *bb) { n++; while (n < bb->size) { if (bb->data[n]) return n; n++; } return -1; } /** * memory_bm_next_pfn - find the pfn that corresponds to the next set bit * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is * returned. * * It is required to run memory_bm_position_reset() before the first call to * this function. */ static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) { struct zone_bitmap *zone_bm; struct bm_block *bb; int chunk; int bit; do { bb = bm->cur.block; do { chunk = bm->cur.chunk; bit = bm->cur.bit; do { bit = next_bit_in_chunk(bit, bb->data + chunk); if (bit >= 0) goto Return_pfn; chunk = next_chunk_in_block(chunk, bb); bit = -1; } while (chunk >= 0); bb = bb->next; bm->cur.block = bb; memory_bm_reset_chunk(bm); } while (bb); zone_bm = bm->cur.zone_bm->next; if (zone_bm) { bm->cur.zone_bm = zone_bm; bm->cur.block = zone_bm->bm_blocks; memory_bm_reset_chunk(bm); } } while (zone_bm); memory_bm_position_reset(bm); return BM_END_OF_MAP; Return_pfn: bm->cur.chunk = chunk; bm->cur.bit = bit; return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit; } /** * This structure represents a range of page frames the contents of which * should not be saved during the suspend. */ struct nosave_region { struct list_head list; unsigned long start_pfn; unsigned long end_pfn; }; static LIST_HEAD(nosave_regions); /** * register_nosave_region - register a range of page frames the contents * of which should not be saved during the suspend (to be used in the early * initialization code) */ void __init __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn, int use_kmalloc) { struct nosave_region *region; if (start_pfn >= end_pfn) return; if (!list_empty(&nosave_regions)) { /* Try to extend the previous region (they should be sorted) */ region = list_entry(nosave_regions.prev, struct nosave_region, list); if (region->end_pfn == start_pfn) { region->end_pfn = end_pfn; goto Report; } } if (use_kmalloc) { /* during init, this shouldn't fail */ region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL); BUG_ON(!region); } else /* This allocation cannot fail */ region = alloc_bootmem_low(sizeof(struct nosave_region)); region->start_pfn = start_pfn; region->end_pfn = end_pfn; list_add_tail(®ion->list, &nosave_regions); Report: printk("swsusp: Registered nosave memory region: %016lx - %016lx\n", start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT); } /* * Set bits in this map correspond to the page frames the contents of which * should not be saved during the suspend. */ static struct memory_bitmap *forbidden_pages_map; /* Set bits in this map correspond to free page frames. */ static struct memory_bitmap *free_pages_map; /* * Each page frame allocated for creating the image is marked by setting the * corresponding bits in forbidden_pages_map and free_pages_map simultaneously */ void swsusp_set_page_free(struct page *page) { if (free_pages_map) memory_bm_set_bit(free_pages_map, page_to_pfn(page)); } static int swsusp_page_is_free(struct page *page) { return free_pages_map ? memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0; } void swsusp_unset_page_free(struct page *page) { if (free_pages_map) memory_bm_clear_bit(free_pages_map, page_to_pfn(page)); } static void swsusp_set_page_forbidden(struct page *page) { if (forbidden_pages_map) memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page)); } int swsusp_page_is_forbidden(struct page *page) { return forbidden_pages_map ? memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0; } static void swsusp_unset_page_forbidden(struct page *page) { if (forbidden_pages_map) memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page)); } /** * mark_nosave_pages - set bits corresponding to the page frames the * contents of which should not be saved in a given bitmap. */ static void mark_nosave_pages(struct memory_bitmap *bm) { struct nosave_region *region; if (list_empty(&nosave_regions)) return; list_for_each_entry(region, &nosave_regions, list) { unsigned long pfn; printk("swsusp: Marking nosave pages: %016lx - %016lx\n", region->start_pfn << PAGE_SHIFT, region->end_pfn << PAGE_SHIFT); for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++) if (pfn_valid(pfn)) memory_bm_set_bit(bm, pfn); } } /** * create_basic_memory_bitmaps - create bitmaps needed for marking page * frames that should not be saved and free page frames. The pointers * forbidden_pages_map and free_pages_map are only modified if everything * goes well, because we don't want the bits to be used before both bitmaps * are set up. */ int create_basic_memory_bitmaps(void) { struct memory_bitmap *bm1, *bm2; int error = 0; BUG_ON(forbidden_pages_map || free_pages_map); bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); if (!bm1) return -ENOMEM; error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY); if (error) goto Free_first_object; bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); if (!bm2) goto Free_first_bitmap; error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY); if (error) goto Free_second_object; forbidden_pages_map = bm1; free_pages_map = bm2; mark_nosave_pages(forbidden_pages_map); printk("swsusp: Basic memory bitmaps created\n"); return 0; Free_second_object: kfree(bm2); Free_first_bitmap: memory_bm_free(bm1, PG_UNSAFE_CLEAR); Free_first_object: kfree(bm1); return -ENOMEM; } /** * free_basic_memory_bitmaps - free memory bitmaps allocated by * create_basic_memory_bitmaps(). The auxiliary pointers are necessary * so that the bitmaps themselves are not referred to while they are being * freed. */ void free_basic_memory_bitmaps(void) { struct memory_bitmap *bm1, *bm2; BUG_ON(!(forbidden_pages_map && free_pages_map)); bm1 = forbidden_pages_map; bm2 = free_pages_map; forbidden_pages_map = NULL; free_pages_map = NULL; memory_bm_free(bm1, PG_UNSAFE_CLEAR); kfree(bm1); memory_bm_free(bm2, PG_UNSAFE_CLEAR); kfree(bm2); printk("swsusp: Basic memory bitmaps freed\n"); } /** * snapshot_additional_pages - estimate the number of additional pages * be needed for setting up the suspend image data structures for given * zone (usually the returned value is greater than the exact number) */ unsigned int snapshot_additional_pages(struct zone *zone) { unsigned int res; res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE); return 2 * res; } #ifdef CONFIG_HIGHMEM /** * count_free_highmem_pages - compute the total number of free highmem * pages, system-wide. */ static unsigned int count_free_highmem_pages(void) { struct zone *zone; unsigned int cnt = 0; for_each_zone(zone) if (populated_zone(zone) && is_highmem(zone)) cnt += zone_page_state(zone, NR_FREE_PAGES); return cnt; } /** * saveable_highmem_page - Determine whether a highmem page should be * included in the suspend image. * * We should save the page if it isn't Nosave or NosaveFree, or Reserved, * and it isn't a part of a free chunk of pages. */ static struct page *saveable_highmem_page(unsigned long pfn) { struct page *page; if (!pfn_valid(pfn)) return NULL; page = pfn_to_page(pfn); BUG_ON(!PageHighMem(page)); if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) || PageReserved(page)) return NULL; return page; } /** * count_highmem_pages - compute the total number of saveable highmem * pages. */ unsigned int count_highmem_pages(void) { struct zone *zone; unsigned int n = 0; for_each_zone(zone) { unsigned long pfn, max_zone_pfn; if (!is_highmem(zone)) continue; mark_free_pages(zone); max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (saveable_highmem_page(pfn)) n++; } return n; } #else static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; } static inline unsigned int count_highmem_pages(void) { return 0; } #endif /* CONFIG_HIGHMEM */ /** * saveable - Determine whether a non-highmem page should be included in * the suspend image. * * We should save the page if it isn't Nosave, and is not in the range * of pages statically defined as 'unsaveable', and it isn't a part of * a free chunk of pages. */ static struct page *saveable_page(unsigned long pfn) { struct page *page; if (!pfn_valid(pfn)) return NULL; page = pfn_to_page(pfn); BUG_ON(PageHighMem(page)); if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) return NULL; if (PageReserved(page) && pfn_is_nosave(pfn)) return NULL; return page; } /** * count_data_pages - compute the total number of saveable non-highmem * pages. */ unsigned int count_data_pages(void) { struct zone *zone; unsigned long pfn, max_zone_pfn; unsigned int n = 0; for_each_zone(zone) { if (is_highmem(zone)) continue; mark_free_pages(zone); max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if(saveable_page(pfn)) n++; } return n; } /* This is needed, because copy_page and memcpy are not usable for copying * task structs. */ static inline void do_copy_page(long *dst, long *src) { int n; for (n = PAGE_SIZE / sizeof(long); n; n--) *dst++ = *src++; } #ifdef CONFIG_HIGHMEM static inline struct page * page_is_saveable(struct zone *zone, unsigned long pfn) { return is_highmem(zone) ? saveable_highmem_page(pfn) : saveable_page(pfn); } static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { struct page *s_page, *d_page; void *src, *dst; s_page = pfn_to_page(src_pfn); d_page = pfn_to_page(dst_pfn); if (PageHighMem(s_page)) { src = kmap_atomic(s_page, KM_USER0); dst = kmap_atomic(d_page, KM_USER1); do_copy_page(dst, src); kunmap_atomic(src, KM_USER0); kunmap_atomic(dst, KM_USER1); } else { src = page_address(s_page); if (PageHighMem(d_page)) { /* Page pointed to by src may contain some kernel * data modified by kmap_atomic() */ do_copy_page(buffer, src); dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0); memcpy(dst, buffer, PAGE_SIZE); kunmap_atomic(dst, KM_USER0); } else { dst = page_address(d_page); do_copy_page(dst, src); } } } #else #define page_is_saveable(zone, pfn) saveable_page(pfn) static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { do_copy_page(page_address(pfn_to_page(dst_pfn)), page_address(pfn_to_page(src_pfn))); } #endif /* CONFIG_HIGHMEM */ static void copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) { struct zone *zone; unsigned long pfn; for_each_zone(zone) { unsigned long max_zone_pfn; mark_free_pages(zone); max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (page_is_saveable(zone, pfn)) memory_bm_set_bit(orig_bm, pfn); } memory_bm_position_reset(orig_bm); memory_bm_position_reset(copy_bm); for(;;) { pfn = memory_bm_next_pfn(orig_bm); if (unlikely(pfn == BM_END_OF_MAP)) break; copy_data_page(memory_bm_next_pfn(copy_bm), pfn); } } /* Total number of image pages */ static unsigned int nr_copy_pages; /* Number of pages needed for saving the original pfns of the image pages */ static unsigned int nr_meta_pages; /** * swsusp_free - free pages allocated for the suspend. * * Suspend pages are alocated before the atomic copy is made, so we * need to release them after the resume. */ void swsusp_free(void) { struct zone *zone; unsigned long pfn, max_zone_pfn; for_each_zone(zone) { max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (pfn_valid(pfn)) { struct page *page = pfn_to_page(pfn); if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) { swsusp_unset_page_forbidden(page); swsusp_unset_page_free(page); __free_page(page); } } } nr_copy_pages = 0; nr_meta_pages = 0; restore_pblist = NULL; buffer = NULL; } #ifdef CONFIG_HIGHMEM /** * count_pages_for_highmem - compute the number of non-highmem pages * that will be necessary for creating copies of highmem pages. */ static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { unsigned int free_highmem = count_free_highmem_pages(); if (free_highmem >= nr_highmem) nr_highmem = 0; else nr_highmem -= free_highmem; return nr_highmem; } #else static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; } #endif /* CONFIG_HIGHMEM */ /** * enough_free_mem - Make sure we have enough free memory for the * snapshot image. */ static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) { struct zone *zone; unsigned int free = 0, meta = 0; for_each_zone(zone) { meta += snapshot_additional_pages(zone); if (!is_highmem(zone)) free += zone_page_state(zone, NR_FREE_PAGES); } nr_pages += count_pages_for_highmem(nr_highmem); pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n", nr_pages, PAGES_FOR_IO, meta, free); return free > nr_pages + PAGES_FOR_IO + meta; } #ifdef CONFIG_HIGHMEM /** * get_highmem_buffer - if there are some highmem pages in the suspend * image, we may need the buffer to copy them and/or load their data. */ static inline int get_highmem_buffer(int safe_needed) { buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed); return buffer ? 0 : -ENOMEM; } /** * alloc_highmem_image_pages - allocate some highmem pages for the image. * Try to allocate as many pages as needed, but if the number of free * highmem pages is lesser than that, allocate them all. */ static inline unsigned int alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem) { unsigned int to_alloc = count_free_highmem_pages(); if (to_alloc > nr_highmem) to_alloc = nr_highmem; nr_highmem -= to_alloc; while (to_alloc-- > 0) { struct page *page; page = alloc_image_page(__GFP_HIGHMEM); memory_bm_set_bit(bm, page_to_pfn(page)); } return nr_highmem; } #else static inline int get_highmem_buffer(int safe_needed) { return 0; } static inline unsigned int alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } #endif /* CONFIG_HIGHMEM */ /** * swsusp_alloc - allocate memory for the suspend image * * We first try to allocate as many highmem pages as there are * saveable highmem pages in the system. If that fails, we allocate * non-highmem pages for the copies of the remaining highmem ones. * * In this approach it is likely that the copies of highmem pages will * also be located in the high memory, because of the way in which * copy_data_pages() works. */ static int swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, unsigned int nr_pages, unsigned int nr_highmem) { int error; error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); if (error) goto Free; error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); if (error) goto Free; if (nr_highmem > 0) { error = get_highmem_buffer(PG_ANY); if (error) goto Free; nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem); } while (nr_pages-- > 0) { struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); if (!page) goto Free; memory_bm_set_bit(copy_bm, page_to_pfn(page)); } return 0; Free: swsusp_free(); return -ENOMEM; } /* Memory bitmap used for marking saveable pages (during suspend) or the * suspend image pages (during resume) */ static struct memory_bitmap orig_bm; /* Memory bitmap used on suspend for marking allocated pages that will contain * the copies of saveable pages. During resume it is initially used for * marking the suspend image pages, but then its set bits are duplicated in * @orig_bm and it is released. Next, on systems with high memory, it may be * used for marking "safe" highmem pages, but it has to be reinitialized for * this purpose. */ static struct memory_bitmap copy_bm; asmlinkage int swsusp_save(void) { unsigned int nr_pages, nr_highmem; printk("swsusp: critical section: \n"); drain_local_pages(); nr_pages = count_data_pages(); nr_highmem = count_highmem_pages(); printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem); if (!enough_free_mem(nr_pages, nr_highmem)) { printk(KERN_ERR "swsusp: Not enough free memory\n"); return -ENOMEM; } if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) { printk(KERN_ERR "swsusp: Memory allocation failed\n"); return -ENOMEM; } /* During allocating of suspend pagedir, new cold pages may appear. * Kill them. */ drain_local_pages(); copy_data_pages(©_bm, &orig_bm); /* * End of critical section. From now on, we can write to memory, * but we should not touch disk. This specially means we must _not_ * touch swap space! Except we must write out our image of course. */ nr_pages += nr_highmem; nr_copy_pages = nr_pages; nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); printk("swsusp: critical section: done (%d pages copied)\n", nr_pages); return 0; } #ifndef CONFIG_ARCH_HIBERNATION_HEADER static int init_header_complete(struct swsusp_info *info) { memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname)); info->version_code = LINUX_VERSION_CODE; return 0; } static char *check_image_kernel(struct swsusp_info *info) { if (info->version_code != LINUX_VERSION_CODE) return "kernel version"; if (strcmp(info->uts.sysname,init_utsname()->sysname)) return "system type"; if (strcmp(info->uts.release,init_utsname()->release)) return "kernel release"; if (strcmp(info->uts.version,init_utsname()->version)) return "version"; if (strcmp(info->uts.machine,init_utsname()->machine)) return "machine"; return NULL; } #endif /* CONFIG_ARCH_HIBERNATION_HEADER */ static int init_header(struct swsusp_info *info) { memset(info, 0, sizeof(struct swsusp_info)); info->num_physpages = num_physpages; info->image_pages = nr_copy_pages; info->pages = nr_copy_pages + nr_meta_pages + 1; info->size = info->pages; info->size <<= PAGE_SHIFT; return init_header_complete(info); } /** * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm * are stored in the array @buf[] (1 page at a time) */ static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm) { int j; for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { buf[j] = memory_bm_next_pfn(bm); if (unlikely(buf[j] == BM_END_OF_MAP)) break; } } /** * snapshot_read_next - used for reading the system memory snapshot. * * On the first call to it @handle should point to a zeroed * snapshot_handle structure. The structure gets updated and a pointer * to it should be passed to this function every next time. * * The @count parameter should contain the number of bytes the caller * wants to read from the snapshot. It must not be zero. * * On success the function returns a positive number. Then, the caller * is allowed to read up to the returned number of bytes from the memory * location computed by the data_of() macro. The number returned * may be smaller than @count, but this only happens if the read would * cross a page boundary otherwise. * * The function returns 0 to indicate the end of data stream condition, * and a negative number is returned on error. In such cases the * structure pointed to by @handle is not updated and should not be used * any more. */ int snapshot_read_next(struct snapshot_handle *handle, size_t count) { if (handle->cur > nr_meta_pages + nr_copy_pages) return 0; if (!buffer) { /* This makes the buffer be freed by swsusp_free() */ buffer = get_image_page(GFP_ATOMIC, PG_ANY); if (!buffer) return -ENOMEM; } if (!handle->offset) { int error; error = init_header((struct swsusp_info *)buffer); if (error) return error; handle->buffer = buffer; memory_bm_position_reset(&orig_bm); memory_bm_position_reset(©_bm); } if (handle->prev < handle->cur) { if (handle->cur <= nr_meta_pages) { memset(buffer, 0, PAGE_SIZE); pack_pfns(buffer, &orig_bm); } else { struct page *page; page = pfn_to_page(memory_bm_next_pfn(©_bm)); if (PageHighMem(page)) { /* Highmem pages are copied to the buffer, * because we can't return with a kmapped * highmem page (we may not be called again). */ void *kaddr; kaddr = kmap_atomic(page, KM_USER0); memcpy(buffer, kaddr, PAGE_SIZE); kunmap_atomic(kaddr, KM_USER0); handle->buffer = buffer; } else { handle->buffer = page_address(page); } } handle->prev = handle->cur; } handle->buf_offset = handle->cur_offset; if (handle->cur_offset + count >= PAGE_SIZE) { count = PAGE_SIZE - handle->cur_offset; handle->cur_offset = 0; handle->cur++; } else { handle->cur_offset += count; } handle->offset += count; return count; } /** * mark_unsafe_pages - mark the pages that cannot be used for storing * the image during resume, because they conflict with the pages that * had been used before suspend */ static int mark_unsafe_pages(struct memory_bitmap *bm) { struct zone *zone; unsigned long pfn, max_zone_pfn; /* Clear page flags */ for_each_zone(zone) { max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (pfn_valid(pfn)) swsusp_unset_page_free(pfn_to_page(pfn)); } /* Mark pages that correspond to the "original" pfns as "unsafe" */ memory_bm_position_reset(bm); do { pfn = memory_bm_next_pfn(bm); if (likely(pfn != BM_END_OF_MAP)) { if (likely(pfn_valid(pfn))) swsusp_set_page_free(pfn_to_page(pfn)); else return -EFAULT; } } while (pfn != BM_END_OF_MAP); allocated_unsafe_pages = 0; return 0; } static void duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src) { unsigned long pfn; memory_bm_position_reset(src); pfn = memory_bm_next_pfn(src); while (pfn != BM_END_OF_MAP) { memory_bm_set_bit(dst, pfn); pfn = memory_bm_next_pfn(src); } } static int check_header(struct swsusp_info *info) { char *reason; reason = check_image_kernel(info); if (!reason && info->num_physpages != num_physpages) reason = "memory size"; if (reason) { printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason); return -EPERM; } return 0; } /** * load header - check the image header and copy data from it */ static int load_header(struct swsusp_info *info) { int error; restore_pblist = NULL; error = check_header(info); if (!error) { nr_copy_pages = info->image_pages; nr_meta_pages = info->pages - info->image_pages - 1; } return error; } /** * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set * the corresponding bit in the memory bitmap @bm */ static inline void unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) { int j; for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { if (unlikely(buf[j] == BM_END_OF_MAP)) break; memory_bm_set_bit(bm, buf[j]); } } /* List of "safe" pages that may be used to store data loaded from the suspend * image */ static struct linked_page *safe_pages_list; #ifdef CONFIG_HIGHMEM /* struct highmem_pbe is used for creating the list of highmem pages that * should be restored atomically during the resume from disk, because the page * frames they have occupied before the suspend are in use. */ struct highmem_pbe { struct page *copy_page; /* data is here now */ struct page *orig_page; /* data was here before the suspend */ struct highmem_pbe *next; }; /* List of highmem PBEs needed for restoring the highmem pages that were * allocated before the suspend and included in the suspend image, but have * also been allocated by the "resume" kernel, so their contents cannot be * written directly to their "original" page frames. */ static struct highmem_pbe *highmem_pblist; /** * count_highmem_image_pages - compute the number of highmem pages in the * suspend image. The bits in the memory bitmap @bm that correspond to the * image pages are assumed to be set. */ static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { unsigned long pfn; unsigned int cnt = 0; memory_bm_position_reset(bm); pfn = memory_bm_next_pfn(bm); while (pfn != BM_END_OF_MAP) { if (PageHighMem(pfn_to_page(pfn))) cnt++; pfn = memory_bm_next_pfn(bm); } return cnt; } /** * prepare_highmem_image - try to allocate as many highmem pages as * there are highmem image pages (@nr_highmem_p points to the variable * containing the number of highmem image pages). The pages that are * "safe" (ie. will not be overwritten when the suspend image is * restored) have the corresponding bits set in @bm (it must be * unitialized). * * NOTE: This function should not be called if there are no highmem * image pages. */ static unsigned int safe_highmem_pages; static struct memory_bitmap *safe_highmem_bm; static int prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) { unsigned int to_alloc; if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE)) return -ENOMEM; if (get_highmem_buffer(PG_SAFE)) return -ENOMEM; to_alloc = count_free_highmem_pages(); if (to_alloc > *nr_highmem_p) to_alloc = *nr_highmem_p; else *nr_highmem_p = to_alloc; safe_highmem_pages = 0; while (to_alloc-- > 0) { struct page *page; page = alloc_page(__GFP_HIGHMEM); if (!swsusp_page_is_free(page)) { /* The page is "safe", set its bit the bitmap */ memory_bm_set_bit(bm, page_to_pfn(page)); safe_highmem_pages++; } /* Mark the page as allocated */ swsusp_set_page_forbidden(page); swsusp_set_page_free(page); } memory_bm_position_reset(bm); safe_highmem_bm = bm; return 0; } /** * get_highmem_page_buffer - for given highmem image page find the buffer * that suspend_write_next() should set for its caller to write to. * * If the page is to be saved to its "original" page frame or a copy of * the page is to be made in the highmem, @buffer is returned. Otherwise, * the copy of the page is to be made in normal memory, so the address of * the copy is returned. * * If @buffer is returned, the caller of suspend_write_next() will write * the page's contents to @buffer, so they will have to be copied to the * right location on the next call to suspend_write_next() and it is done * with the help of copy_last_highmem_page(). For this purpose, if * @buffer is returned, @last_highmem page is set to the page to which * the data will have to be copied from @buffer. */ static struct page *last_highmem_page; static void * get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) { struct highmem_pbe *pbe; void *kaddr; if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) { /* We have allocated the "original" page frame and we can * use it directly to store the loaded page. */ last_highmem_page = page; return buffer; } /* The "original" page frame has not been allocated and we have to * use a "safe" page frame to store the loaded page. */ pbe = chain_alloc(ca, sizeof(struct highmem_pbe)); if (!pbe) { swsusp_free(); return NULL; } pbe->orig_page = page; if (safe_highmem_pages > 0) { struct page *tmp; /* Copy of the page will be stored in high memory */ kaddr = buffer; tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm)); safe_highmem_pages--; last_highmem_page = tmp; pbe->copy_page = tmp; } else { /* Copy of the page will be stored in normal memory */ kaddr = safe_pages_list; safe_pages_list = safe_pages_list->next; pbe->copy_page = virt_to_page(kaddr); } pbe->next = highmem_pblist; highmem_pblist = pbe; return kaddr; } /** * copy_last_highmem_page - copy the contents of a highmem image from * @buffer, where the caller of snapshot_write_next() has place them, * to the right location represented by @last_highmem_page . */ static void copy_last_highmem_page(void) { if (last_highmem_page) { void *dst; dst = kmap_atomic(last_highmem_page, KM_USER0); memcpy(dst, buffer, PAGE_SIZE); kunmap_atomic(dst, KM_USER0); last_highmem_page = NULL; } } static inline int last_highmem_page_copied(void) { return !last_highmem_page; } static inline void free_highmem_data(void) { if (safe_highmem_bm) memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR); if (buffer) free_image_page(buffer, PG_UNSAFE_CLEAR); } #else static inline int get_safe_write_buffer(void) { return 0; } static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; } static inline int prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) { return 0; } static inline void * get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) { return NULL; } static inline void copy_last_highmem_page(void) {} static inline int last_highmem_page_copied(void) { return 1; } static inline void free_highmem_data(void) {} #endif /* CONFIG_HIGHMEM */ /** * prepare_image - use the memory bitmap @bm to mark the pages that will * be overwritten in the process of restoring the system memory state * from the suspend image ("unsafe" pages) and allocate memory for the * image. * * The idea is to allocate a new memory bitmap first and then allocate * as many pages as needed for the image data, but not to assign these * pages to specific tasks initially. Instead, we just mark them as * allocated and create a lists of "safe" pages that will be used * later. On systems with high memory a list of "safe" highmem pages is * also created. */ #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) { unsigned int nr_pages, nr_highmem; struct linked_page *sp_list, *lp; int error; /* If there is no highmem, the buffer will not be necessary */ free_image_page(buffer, PG_UNSAFE_CLEAR); buffer = NULL; nr_highmem = count_highmem_image_pages(bm); error = mark_unsafe_pages(bm); if (error) goto Free; error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE); if (error) goto Free; duplicate_memory_bitmap(new_bm, bm); memory_bm_free(bm, PG_UNSAFE_KEEP); if (nr_highmem > 0) { error = prepare_highmem_image(bm, &nr_highmem); if (error) goto Free; } /* Reserve some safe pages for potential later use. * * NOTE: This way we make sure there will be enough safe pages for the * chain_alloc() in get_buffer(). It is a bit wasteful, but * nr_copy_pages cannot be greater than 50% of the memory anyway. */ sp_list = NULL; /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */ nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE); while (nr_pages > 0) { lp = get_image_page(GFP_ATOMIC, PG_SAFE); if (!lp) { error = -ENOMEM; goto Free; } lp->next = sp_list; sp_list = lp; nr_pages--; } /* Preallocate memory for the image */ safe_pages_list = NULL; nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; while (nr_pages > 0) { lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC); if (!lp) { error = -ENOMEM; goto Free; } if (!swsusp_page_is_free(virt_to_page(lp))) { /* The page is "safe", add it to the list */ lp->next = safe_pages_list; safe_pages_list = lp; } /* Mark the page as allocated */ swsusp_set_page_forbidden(virt_to_page(lp)); swsusp_set_page_free(virt_to_page(lp)); nr_pages--; } /* Free the reserved safe pages so that chain_alloc() can use them */ while (sp_list) { lp = sp_list->next; free_image_page(sp_list, PG_UNSAFE_CLEAR); sp_list = lp; } return 0; Free: swsusp_free(); return error; } /** * get_buffer - compute the address that snapshot_write_next() should * set for its caller to write to. */ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) { struct pbe *pbe; struct page *page = pfn_to_page(memory_bm_next_pfn(bm)); if (PageHighMem(page)) return get_highmem_page_buffer(page, ca); if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) /* We have allocated the "original" page frame and we can * use it directly to store the loaded page. */ return page_address(page); /* The "original" page frame has not been allocated and we have to * use a "safe" page frame to store the loaded page. */ pbe = chain_alloc(ca, sizeof(struct pbe)); if (!pbe) { swsusp_free(); return NULL; } pbe->orig_address = page_address(page); pbe->address = safe_pages_list; safe_pages_list = safe_pages_list->next; pbe->next = restore_pblist; restore_pblist = pbe; return pbe->address; } /** * snapshot_write_next - used for writing the system memory snapshot. * * On the first call to it @handle should point to a zeroed * snapshot_handle structure. The structure gets updated and a pointer * to it should be passed to this function every next time. * * The @count parameter should contain the number of bytes the caller * wants to write to the image. It must not be zero. * * On success the function returns a positive number. Then, the caller * is allowed to write up to the returned number of bytes to the memory * location computed by the data_of() macro. The number returned * may be smaller than @count, but this only happens if the write would * cross a page boundary otherwise. * * The function returns 0 to indicate the "end of file" condition, * and a negative number is returned on error. In such cases the * structure pointed to by @handle is not updated and should not be used * any more. */ int snapshot_write_next(struct snapshot_handle *handle, size_t count) { static struct chain_allocator ca; int error = 0; /* Check if we have already loaded the entire image */ if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) return 0; if (handle->offset == 0) { if (!buffer) /* This makes the buffer be freed by swsusp_free() */ buffer = get_image_page(GFP_ATOMIC, PG_ANY); if (!buffer) return -ENOMEM; handle->buffer = buffer; } handle->sync_read = 1; if (handle->prev < handle->cur) { if (handle->prev == 0) { error = load_header(buffer); if (error) return error; error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); if (error) return error; } else if (handle->prev <= nr_meta_pages) { unpack_orig_pfns(buffer, ©_bm); if (handle->prev == nr_meta_pages) { error = prepare_image(&orig_bm, ©_bm); if (error) return error; chain_init(&ca, GFP_ATOMIC, PG_SAFE); memory_bm_position_reset(&orig_bm); restore_pblist = NULL; handle->buffer = get_buffer(&orig_bm, &ca); handle->sync_read = 0; if (!handle->buffer) return -ENOMEM; } } else { copy_last_highmem_page(); handle->buffer = get_buffer(&orig_bm, &ca); if (handle->buffer != buffer) handle->sync_read = 0; } handle->prev = handle->cur; } handle->buf_offset = handle->cur_offset; if (handle->cur_offset + count >= PAGE_SIZE) { count = PAGE_SIZE - handle->cur_offset; handle->cur_offset = 0; handle->cur++; } else { handle->cur_offset += count; } handle->offset += count; return count; } /** * snapshot_write_finalize - must be called after the last call to * snapshot_write_next() in case the last page in the image happens * to be a highmem page and its contents should be stored in the * highmem. Additionally, it releases the memory that will not be * used any more. */ void snapshot_write_finalize(struct snapshot_handle *handle) { copy_last_highmem_page(); /* Free only if we have loaded the image entirely */ if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) { memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR); free_highmem_data(); } } int snapshot_image_loaded(struct snapshot_handle *handle) { return !(!nr_copy_pages || !last_highmem_page_copied() || handle->cur <= nr_meta_pages + nr_copy_pages); } #ifdef CONFIG_HIGHMEM /* Assumes that @buf is ready and points to a "safe" page */ static inline void swap_two_pages_data(struct page *p1, struct page *p2, void *buf) { void *kaddr1, *kaddr2; kaddr1 = kmap_atomic(p1, KM_USER0); kaddr2 = kmap_atomic(p2, KM_USER1); memcpy(buf, kaddr1, PAGE_SIZE); memcpy(kaddr1, kaddr2, PAGE_SIZE); memcpy(kaddr2, buf, PAGE_SIZE); kunmap_atomic(kaddr1, KM_USER0); kunmap_atomic(kaddr2, KM_USER1); } /** * restore_highmem - for each highmem page that was allocated before * the suspend and included in the suspend image, and also has been * allocated by the "resume" kernel swap its current (ie. "before * resume") contents with the previous (ie. "before suspend") one. * * If the resume eventually fails, we can call this function once * again and restore the "before resume" highmem state. */ int restore_highmem(void) { struct highmem_pbe *pbe = highmem_pblist; void *buf; if (!pbe) return 0; buf = get_image_page(GFP_ATOMIC, PG_SAFE); if (!buf) return -ENOMEM; while (pbe) { swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf); pbe = pbe->next; } free_image_page(buf, PG_UNSAFE_CLEAR); return 0; } #endif /* CONFIG_HIGHMEM */