diff options
Diffstat (limited to 'kernel/power/snapshot.c')
| -rw-r--r-- | kernel/power/snapshot.c | 1155 |
1 files changed, 801 insertions, 354 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 75d4886..1b84313 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -34,10 +34,12 @@ #include "power.h" -struct pbe *pagedir_nosave; +/* List of PBEs used for creating and restoring the suspend image */ +struct pbe *restore_pblist; + static unsigned int nr_copy_pages; static unsigned int nr_meta_pages; -static unsigned long *buffer; +static void *buffer; #ifdef CONFIG_HIGHMEM unsigned int count_highmem_pages(void) @@ -156,240 +158,637 @@ static inline int save_highmem(void) {return 0;} static inline int restore_highmem(void) {return 0;} #endif -static int pfn_is_nosave(unsigned long pfn) +/** + * @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 are marked with the PG_nosave_free flag + * and we count them using unsafe_pages + */ + +#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 *alloc_image_page(gfp_t gfp_mask, int safe_needed) { - unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; - unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; - return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); + void *res; + + res = (void *)get_zeroed_page(gfp_mask); + if (safe_needed) + while (res && PageNosaveFree(virt_to_page(res))) { + /* The page is unsafe, mark it for swsusp_free() */ + SetPageNosave(virt_to_page(res)); + allocated_unsafe_pages++; + res = (void *)get_zeroed_page(gfp_mask); + } + if (res) { + SetPageNosave(virt_to_page(res)); + SetPageNosaveFree(virt_to_page(res)); + } + return res; +} + +unsigned long get_safe_page(gfp_t gfp_mask) +{ + return (unsigned long)alloc_image_page(gfp_mask, PG_SAFE); } /** - * saveable - Determine whether a page should be cloned or not. - * @pfn: The page - * - * We save a page if it's Reserved, and not in the range of pages - * statically defined as 'unsaveable', or if it isn't reserved, and - * isn't part of a free chunk of pages. + * free_image_page - free page represented by @addr, allocated with + * alloc_image_page (page flags set by it must be cleared) */ -static int saveable(struct zone *zone, unsigned long *zone_pfn) +static inline void free_image_page(void *addr, int clear_nosave_free) { - unsigned long pfn = *zone_pfn + zone->zone_start_pfn; - struct page *page; + ClearPageNosave(virt_to_page(addr)); + if (clear_nosave_free) + ClearPageNosaveFree(virt_to_page(addr)); + free_page((unsigned long)addr); +} - if (!pfn_valid(pfn)) - return 0; +/* struct linked_page is used to build chains of pages */ - page = pfn_to_page(pfn); - BUG_ON(PageReserved(page) && PageNosave(page)); - if (PageNosave(page)) - return 0; - if (PageReserved(page) && pfn_is_nosave(pfn)) - return 0; - if (PageNosaveFree(page)) - return 0; +#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) - return 1; -} +struct linked_page { + struct linked_page *next; + char data[LINKED_PAGE_DATA_SIZE]; +} __attribute__((packed)); -unsigned int count_data_pages(void) +static inline void +free_list_of_pages(struct linked_page *list, int clear_page_nosave) { - struct zone *zone; - unsigned long zone_pfn; - unsigned int n = 0; + while (list) { + struct linked_page *lp = list->next; - for_each_zone (zone) { - if (is_highmem(zone)) - continue; - mark_free_pages(zone); - for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) - n += saveable(zone, &zone_pfn); + free_image_page(list, clear_page_nosave); + list = lp; } - return n; } -static void copy_data_pages(struct pbe *pblist) +/** + * 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) { - struct zone *zone; - unsigned long zone_pfn; - struct pbe *pbe, *p; + ca->chain = NULL; + ca->used_space = LINKED_PAGE_DATA_SIZE; + ca->gfp_mask = gfp_mask; + ca->safe_needed = safe_needed; +} - pbe = pblist; - for_each_zone (zone) { - if (is_highmem(zone)) - continue; - mark_free_pages(zone); - /* This is necessary for swsusp_free() */ - for_each_pb_page (p, pblist) - SetPageNosaveFree(virt_to_page(p)); - for_each_pbe (p, pblist) - SetPageNosaveFree(virt_to_page(p->address)); - for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { - if (saveable(zone, &zone_pfn)) { - struct page *page; - long *src, *dst; - int n; - - page = pfn_to_page(zone_pfn + zone->zone_start_pfn); - BUG_ON(!pbe); - pbe->orig_address = (unsigned long)page_address(page); - /* copy_page and memcpy are not usable for copying task structs. */ - dst = (long *)pbe->address; - src = (long *)pbe->orig_address; - for (n = PAGE_SIZE / sizeof(long); n; n--) - *dst++ = *src++; - pbe = pbe->next; - } - } +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 = alloc_image_page(ca->gfp_mask, ca->safe_needed); + if (!lp) + return NULL; + + lp->next = ca->chain; + ca->chain = lp; + ca->used_space = 0; } - BUG_ON(pbe); + 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)); +} /** - * free_pagedir - free pages allocated with alloc_pagedir() + * 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. + * + * NOTE: Memory bitmaps are used for two types of operations only: + * "set a bit" and "find the next bit set". Moreover, the searching + * is always carried out after all of the "set a bit" operations + * on given bitmap. */ -static void free_pagedir(struct pbe *pblist, int clear_nosave_free) +#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) { - struct pbe *pbe; + bm->cur.chunk = 0; + bm->cur.bit = -1; +} - while (pblist) { - pbe = (pblist + PB_PAGE_SKIP)->next; - ClearPageNosave(virt_to_page(pblist)); - if (clear_nosave_free) - ClearPageNosaveFree(virt_to_page(pblist)); - free_page((unsigned long)pblist); - pblist = pbe; - } +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); + /** - * fill_pb_page - Create a list of PBEs on a given memory page + * create_bm_block_list - create a list of block bitmap objects */ -static inline void fill_pb_page(struct pbe *pbpage) +static inline struct bm_block * +create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca) { - struct pbe *p; + struct bm_block *bblist = NULL; + + while (nr_blocks-- > 0) { + struct bm_block *bb; - p = pbpage; - pbpage += PB_PAGE_SKIP; - do - p->next = p + 1; - while (++p < pbpage); + bb = chain_alloc(ca, sizeof(struct bm_block)); + if (!bb) + return NULL; + + bb->next = bblist; + bblist = bb; + } + return bblist; } /** - * create_pbe_list - Create a list of PBEs on top of a given chain - * of memory pages allocated with alloc_pagedir() + * create_zone_bm_list - create a list of zone bitmap objects */ -static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) +static inline struct zone_bitmap * +create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca) { - struct pbe *pbpage, *p; - unsigned int num = PBES_PER_PAGE; + struct zone_bitmap *zbmlist = NULL; - for_each_pb_page (pbpage, pblist) { - if (num >= nr_pages) - break; + 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); - fill_pb_page(pbpage); - num += PBES_PER_PAGE; + /* Compute the number of zones */ + nr = 0; + for_each_zone (zone) + if (populated_zone(zone) && !is_highmem(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; } - if (pbpage) { - for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++) - p->next = p + 1; - p->next = NULL; + + /* Initialize the zone bitmap objects */ + for_each_zone (zone) { + unsigned long pfn; + + if (!populated_zone(zone) || is_highmem(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 = alloc_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; } -static unsigned int unsafe_pages; +/** + * 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; +} /** - * @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. + * memory_bm_set_bit - set 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. * - * The unsafe pages are marked with the PG_nosave_free flag - * and we count them using unsafe_pages + * If the bit cannot be set, the function returns -EINVAL . */ -static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed) +static int +memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) { - void *res; - - res = (void *)get_zeroed_page(gfp_mask); - if (safe_needed) - while (res && PageNosaveFree(virt_to_page(res))) { - /* The page is unsafe, mark it for swsusp_free() */ - SetPageNosave(virt_to_page(res)); - unsafe_pages++; - res = (void *)get_zeroed_page(gfp_mask); + 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; + if (unlikely(!zone_bm)) + return -EINVAL; } - if (res) { - SetPageNosave(virt_to_page(res)); - SetPageNosaveFree(virt_to_page(res)); + bm->cur.zone_bm = zone_bm; } - return res; + /* 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; + if (unlikely(!bb)) + return -EINVAL; + } + zone_bm->cur_block = bb; + pfn -= bb->start_pfn; + set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK); + return 0; } -unsigned long get_safe_page(gfp_t gfp_mask) +/* 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) { - return (unsigned long)alloc_image_page(gfp_mask, 1); + 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; } /** - * alloc_pagedir - Allocate the page directory. - * - * First, determine exactly how many pages we need and - * allocate them. + * 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. * - * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE - * struct pbe elements (pbes) and the last element in the page points - * to the next page. + * 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; +} + +/** + * 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 res; +} + +/** + * pfn_is_nosave - check if given pfn is in the 'nosave' section + */ + +static inline int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; + unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; + return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); +} + +/** + * saveable - Determine whether a page should be cloned or not. + * @pfn: The page * - * On each page we set up a list of struct_pbe elements. + * We save a 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 pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, - int safe_needed) +static struct page *saveable_page(unsigned long pfn) { - unsigned int num; - struct pbe *pblist, *pbe; + struct page *page; + + if (!pfn_valid(pfn)) + return NULL; - if (!nr_pages) + page = pfn_to_page(pfn); + + if (PageNosave(page)) + return NULL; + if (PageReserved(page) && pfn_is_nosave(pfn)) return NULL; + if (PageNosaveFree(page)) + return NULL; + + return page; +} + +unsigned int count_data_pages(void) +{ + struct zone *zone; + unsigned long pfn, max_zone_pfn; + unsigned int n = 0; - pblist = alloc_image_page(gfp_mask, safe_needed); - /* FIXME: rewrite this ugly loop */ - for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages; - pbe = pbe->next, num += PBES_PER_PAGE) { - pbe += PB_PAGE_SKIP; - pbe->next = alloc_image_page(gfp_mask, safe_needed); + 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++) + n += !!saveable_page(pfn); } - if (!pbe) { /* get_zeroed_page() failed */ - free_pagedir(pblist, 1); - pblist = NULL; - } else - create_pbe_list(pblist, nr_pages); - return pblist; + return n; +} + +static inline void copy_data_page(long *dst, long *src) +{ + int n; + + /* copy_page and memcpy are not usable for copying task structs. */ + for (n = PAGE_SIZE / sizeof(long); n; n--) + *dst++ = *src++; +} + +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; + + 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)) + memory_bm_set_bit(orig_bm, pfn); + } + memory_bm_position_reset(orig_bm); + memory_bm_position_reset(copy_bm); + do { + pfn = memory_bm_next_pfn(orig_bm); + if (likely(pfn != BM_END_OF_MAP)) { + struct page *page; + void *src; + + page = pfn_to_page(pfn); + src = page_address(page); + page = pfn_to_page(memory_bm_next_pfn(copy_bm)); + copy_data_page(page_address(page), src); + } + } while (pfn != BM_END_OF_MAP); } /** - * Free pages we allocated for suspend. Suspend pages are alocated - * before atomic copy, so we need to free them after resume. + * 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 zone_pfn; + unsigned long pfn, max_zone_pfn; for_each_zone(zone) { - for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) - if (pfn_valid(zone_pfn + zone->zone_start_pfn)) { - struct page *page; - page = pfn_to_page(zone_pfn + zone->zone_start_pfn); + 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 (PageNosave(page) && PageNosaveFree(page)) { ClearPageNosave(page); ClearPageNosaveFree(page); @@ -399,7 +798,7 @@ void swsusp_free(void) } nr_copy_pages = 0; nr_meta_pages = 0; - pagedir_nosave = NULL; + restore_pblist = NULL; buffer = NULL; } @@ -414,46 +813,57 @@ void swsusp_free(void) static int enough_free_mem(unsigned int nr_pages) { struct zone *zone; - unsigned int n = 0; + unsigned int free = 0, meta = 0; for_each_zone (zone) - if (!is_highmem(zone)) - n += zone->free_pages; - pr_debug("swsusp: available memory: %u pages\n", n); - return n > (nr_pages + PAGES_FOR_IO + - (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); -} + if (!is_highmem(zone)) { + free += zone->free_pages; + meta += snapshot_additional_pages(zone); + } -static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) -{ - struct pbe *p; + pr_debug("swsusp: pages needed: %u + %u + %u, available pages: %u\n", + nr_pages, PAGES_FOR_IO, meta, free); - for_each_pbe (p, pblist) { - p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); - if (!p->address) - return -ENOMEM; - } - return 0; + return free > nr_pages + PAGES_FOR_IO + meta; } -static struct pbe *swsusp_alloc(unsigned int nr_pages) +static int +swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, + unsigned int nr_pages) { - struct pbe *pblist; + int error; - if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) { - printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); - return NULL; - } + error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free; - if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) { - printk(KERN_ERR "suspend: Allocating image pages failed.\n"); - swsusp_free(); - return NULL; + error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free; + + while (nr_pages-- > 0) { + struct page *page = alloc_page(GFP_ATOMIC | __GFP_COLD); + if (!page) + goto Free; + + SetPageNosave(page); + SetPageNosaveFree(page); + memory_bm_set_bit(copy_bm, page_to_pfn(page)); } + return 0; - return pblist; +Free: + swsusp_free(); + return -ENOMEM; } +/* Memory bitmap used for marking saveable pages */ +static struct memory_bitmap orig_bm; +/* Memory bitmap used for marking allocated pages that will contain the copies + * of saveable pages + */ +static struct memory_bitmap copy_bm; + asmlinkage int swsusp_save(void) { unsigned int nr_pages; @@ -464,25 +874,19 @@ asmlinkage int swsusp_save(void) nr_pages = count_data_pages(); printk("swsusp: Need to copy %u pages\n", nr_pages); - pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", - nr_pages, - (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, - PAGES_FOR_IO, nr_free_pages()); - if (!enough_free_mem(nr_pages)) { printk(KERN_ERR "swsusp: Not enough free memory\n"); return -ENOMEM; } - pagedir_nosave = swsusp_alloc(nr_pages); - if (!pagedir_nosave) + if (swsusp_alloc(&orig_bm, ©_bm, nr_pages)) return -ENOMEM; /* During allocating of suspend pagedir, new cold pages may appear. * Kill them. */ drain_local_pages(); - copy_data_pages(pagedir_nosave); + copy_data_pages(©_bm, &orig_bm); /* * End of critical section. From now on, we can write to memory, @@ -511,22 +915,20 @@ static void init_header(struct swsusp_info *info) } /** - * pack_orig_addresses - the .orig_address fields of the PBEs from the - * list starting at @pbe are stored in the array @buf[] (1 page) + * 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 struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe) +static inline void +pack_pfns(unsigned long *buf, struct memory_bitmap *bm) { int j; - for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { - buf[j] = pbe->orig_address; - pbe = pbe->next; + 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; } - if (!pbe) - for (; j < PAGE_SIZE / sizeof(long); j++) - buf[j] = 0; - return pbe; } /** @@ -553,37 +955,39 @@ static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pb int snapshot_read_next(struct snapshot_handle *handle, size_t count) { - if (handle->page > nr_meta_pages + nr_copy_pages) + if (handle->cur > nr_meta_pages + nr_copy_pages) return 0; + if (!buffer) { /* This makes the buffer be freed by swsusp_free() */ - buffer = alloc_image_page(GFP_ATOMIC, 0); + buffer = alloc_image_page(GFP_ATOMIC, PG_ANY); if (!buffer) return -ENOMEM; } if (!handle->offset) { init_header((struct swsusp_info *)buffer); handle->buffer = buffer; - handle->pbe = pagedir_nosave; + memory_bm_position_reset(&orig_bm); + memory_bm_position_reset(©_bm); } - if (handle->prev < handle->page) { - if (handle->page <= nr_meta_pages) { - handle->pbe = pack_orig_addresses(buffer, handle->pbe); - if (!handle->pbe) - handle->pbe = pagedir_nosave; + if (handle->prev < handle->cur) { + if (handle->cur <= nr_meta_pages) { + memset(buffer, 0, PAGE_SIZE); + pack_pfns(buffer, &orig_bm); } else { - handle->buffer = (void *)handle->pbe->address; - handle->pbe = handle->pbe->next; + unsigned long pfn = memory_bm_next_pfn(©_bm); + + handle->buffer = page_address(pfn_to_page(pfn)); } - handle->prev = handle->page; + handle->prev = handle->cur; } - handle->buf_offset = handle->page_offset; - if (handle->page_offset + count >= PAGE_SIZE) { - count = PAGE_SIZE - handle->page_offset; - handle->page_offset = 0; - handle->page++; + 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->page_offset += count; + handle->cur_offset += count; } handle->offset += count; return count; @@ -595,47 +999,50 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count) * had been used before suspend */ -static int mark_unsafe_pages(struct pbe *pblist) +static int mark_unsafe_pages(struct memory_bitmap *bm) { struct zone *zone; - unsigned long zone_pfn; - struct pbe *p; - - if (!pblist) /* a sanity check */ - return -EINVAL; + unsigned long pfn, max_zone_pfn; /* Clear page flags */ for_each_zone (zone) { - for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) - if (pfn_valid(zone_pfn + zone->zone_start_pfn)) - ClearPageNosaveFree(pfn_to_page(zone_pfn + - zone->zone_start_pfn)); + 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)) + ClearPageNosaveFree(pfn_to_page(pfn)); } - /* Mark orig addresses */ - for_each_pbe (p, pblist) { - if (virt_addr_valid(p->orig_address)) - SetPageNosaveFree(virt_to_page(p->orig_address)); - else - return -EFAULT; - } + /* 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))) + SetPageNosaveFree(pfn_to_page(pfn)); + else + return -EFAULT; + } + } while (pfn != BM_END_OF_MAP); - unsafe_pages = 0; + allocated_unsafe_pages = 0; return 0; } -static void copy_page_backup_list(struct pbe *dst, struct pbe *src) +static void +duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src) { - /* We assume both lists contain the same number of elements */ - while (src) { - dst->orig_address = src->orig_address; - dst = dst->next; - src = src->next; + 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) +static inline int check_header(struct swsusp_info *info) { char *reason = NULL; @@ -662,19 +1069,14 @@ static int check_header(struct swsusp_info *info) * load header - check the image header and copy data from it */ -static int load_header(struct snapshot_handle *handle, - struct swsusp_info *info) +static int +load_header(struct swsusp_info *info) { int error; - struct pbe *pblist; + restore_pblist = NULL; error = check_header(info); if (!error) { - pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, 0); - if (!pblist) - return -ENOMEM; - pagedir_nosave = pblist; - handle->pbe = pblist; nr_copy_pages = info->image_pages; nr_meta_pages = info->pages - info->image_pages - 1; } @@ -682,113 +1084,137 @@ static int load_header(struct snapshot_handle *handle, } /** - * unpack_orig_addresses - copy the elements of @buf[] (1 page) to - * the PBEs in the list starting at @pbe + * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set + * the corresponding bit in the memory bitmap @bm */ -static inline struct pbe *unpack_orig_addresses(unsigned long *buf, - struct pbe *pbe) +static inline void +unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) { int j; - for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { - pbe->orig_address = buf[j]; - pbe = pbe->next; + 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]); } - return pbe; } /** - * prepare_image - use metadata contained in the PBE list - * pointed to by pagedir_nosave to mark the pages that will - * be overwritten in the process of restoring the system - * memory state from the image ("unsafe" pages) and allocate - * memory for the image + * 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 the PBE list first and then - * allocate as many pages as it's needed for the image data, - * but not to assign these pages to the PBEs initially. - * Instead, we just mark them as allocated and create a list - * of "safe" which will be used later + * 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 list of "safe" pages that will be used later. */ -struct safe_page { - struct safe_page *next; - char padding[PAGE_SIZE - sizeof(void *)]; -}; +#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) -static struct safe_page *safe_pages; +static struct linked_page *safe_pages_list; -static int prepare_image(struct snapshot_handle *handle) +static int +prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) { - int error = 0; - unsigned int nr_pages = nr_copy_pages; - struct pbe *p, *pblist = NULL; + unsigned int nr_pages; + struct linked_page *sp_list, *lp; + int error; - p = pagedir_nosave; - error = mark_unsafe_pages(p); - if (!error) { - pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1); - if (pblist) - copy_page_backup_list(pblist, p); - free_pagedir(p, 0); - if (!pblist) + 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); + /* 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 - allocated_unsafe_pages; + nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE); + while (nr_pages > 0) { + lp = alloc_image_page(GFP_ATOMIC, PG_SAFE); + if (!lp) { error = -ENOMEM; + goto Free; + } + lp->next = sp_list; + sp_list = lp; + nr_pages--; } - safe_pages = NULL; - if (!error && nr_pages > unsafe_pages) { - nr_pages -= unsafe_pages; - while (nr_pages--) { - struct safe_page *ptr; - - ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC); - if (!ptr) { - error = -ENOMEM; - break; - } - if (!PageNosaveFree(virt_to_page(ptr))) { - /* The page is "safe", add it to the list */ - ptr->next = safe_pages; - safe_pages = ptr; - } - /* Mark the page as allocated */ - SetPageNosave(virt_to_page(ptr)); - SetPageNosaveFree(virt_to_page(ptr)); + /* Preallocate memory for the image */ + safe_pages_list = NULL; + nr_pages = nr_copy_pages - allocated_unsafe_pages; + while (nr_pages > 0) { + lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC); + if (!lp) { + error = -ENOMEM; + goto Free; + } + if (!PageNosaveFree(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 */ + SetPageNosave(virt_to_page(lp)); + SetPageNosaveFree(virt_to_page(lp)); + nr_pages--; } - if (!error) { - pagedir_nosave = pblist; - } else { - handle->pbe = NULL; - swsusp_free(); + /* 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; } -static void *get_buffer(struct snapshot_handle *handle) +/** + * 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 = handle->pbe, *last = handle->last_pbe; - struct page *page = virt_to_page(pbe->orig_address); + struct pbe *pbe; + struct page *page = pfn_to_page(memory_bm_next_pfn(bm)); - if (PageNosave(page) && PageNosaveFree(page)) { - /* - * We have allocated the "original" page frame and we can - * use it directly to store the read page + if (PageNosave(page) && PageNosaveFree(page)) + /* We have allocated the "original" page frame and we can + * use it directly to store the loaded page. */ - pbe->address = 0; - if (last && last->next) - last->next = NULL; - return (void *)pbe->orig_address; - } - /* - * The "original" page frame has not been allocated and we have to - * use a "safe" page frame to store the read 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->address = (unsigned long)safe_pages; - safe_pages = safe_pages->next; - if (last) - last->next = pbe; - handle->last_pbe = pbe; + pbe = chain_alloc(ca, sizeof(struct pbe)); + if (!pbe) { + swsusp_free(); + return NULL; + } + pbe->orig_address = (unsigned long)page_address(page); + pbe->address = (unsigned long)safe_pages_list; + safe_pages_list = safe_pages_list->next; + pbe->next = restore_pblist; + restore_pblist = pbe; return (void *)pbe->address; } @@ -816,46 +1242,60 @@ static void *get_buffer(struct snapshot_handle *handle) int snapshot_write_next(struct snapshot_handle *handle, size_t count) { + static struct chain_allocator ca; int error = 0; - if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages) + /* Check if we have already loaded the entire image */ + if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) return 0; + if (!buffer) { /* This makes the buffer be freed by swsusp_free() */ - buffer = alloc_image_page(GFP_ATOMIC, 0); + buffer = alloc_image_page(GFP_ATOMIC, PG_ANY); if (!buffer) return -ENOMEM; } if (!handle->offset) handle->buffer = buffer; - if (handle->prev < handle->page) { - if (!handle->prev) { - error = load_header(handle, (struct swsusp_info *)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) { - handle->pbe = unpack_orig_addresses(buffer, handle->pbe); - if (!handle->pbe) { - error = prepare_image(handle); + unpack_orig_pfns(buffer, ©_bm); + if (handle->prev == nr_meta_pages) { + error = prepare_image(&orig_bm, ©_bm); if (error) return error; - handle->pbe = pagedir_nosave; - handle->last_pbe = NULL; - handle->buffer = get_buffer(handle); + + 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 { - handle->pbe = handle->pbe->next; - handle->buffer = get_buffer(handle); + handle->buffer = get_buffer(&orig_bm, &ca); + handle->sync_read = 0; } - handle->prev = handle->page; + handle->prev = handle->cur; } - handle->buf_offset = handle->page_offset; - if (handle->page_offset + count >= PAGE_SIZE) { - count = PAGE_SIZE - handle->page_offset; - handle->page_offset = 0; - handle->page++; + 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->page_offset += count; + handle->cur_offset += count; } handle->offset += count; return count; @@ -863,6 +1303,13 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count) int snapshot_image_loaded(struct snapshot_handle *handle) { - return !(!handle->pbe || handle->pbe->next || !nr_copy_pages || - handle->page <= nr_meta_pages + nr_copy_pages); + return !(!nr_copy_pages || + handle->cur <= nr_meta_pages + nr_copy_pages); +} + +void snapshot_free_unused_memory(struct snapshot_handle *handle) +{ + /* 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); } |
