| /* |
| * linux/kernel/power/snapshot.c |
| * |
| * This file provides system snapshot/restore functionality for swsusp. |
| * |
| * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.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 <linux/list.h> |
| #include <linux/slab.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 *); |
| |
| /* |
| * Preferred image size in bytes (tunable via /sys/power/image_size). |
| * When it is set to N, swsusp will do its best to ensure the image |
| * size will not exceed N bytes, but if that is impossible, it will |
| * try to create the smallest image possible. |
| */ |
| unsigned long image_size = 500 * 1024 * 1024; |
| |
| /* 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; |
| } |
| |
| /** |
| * 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 bitmap 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 bitmap) |
| * It also contains the pfns that correspond to the start and end of |
| * the represented memory area. |
| */ |
| |
| #define BM_END_OF_MAP (~0UL) |
| |
| #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE) |
| |
| struct bm_block { |
| struct list_head hook; /* hook into a list of bitmap blocks */ |
| unsigned long start_pfn; /* pfn represented by the first bit */ |
| unsigned long end_pfn; /* pfn represented by the last bit plus 1 */ |
| unsigned long *data; /* bitmap representing pages */ |
| }; |
| |
| static inline unsigned long bm_block_bits(struct bm_block *bb) |
| { |
| return bb->end_pfn - bb->start_pfn; |
| } |
| |
| /* strcut bm_position is used for browsing memory bitmaps */ |
| |
| struct bm_position { |
| struct bm_block *block; |
| int bit; |
| }; |
| |
| struct memory_bitmap { |
| struct list_head blocks; /* list of bitmap blocks */ |
| 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 void memory_bm_position_reset(struct memory_bitmap *bm) |
| { |
| bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook); |
| bm->cur.bit = 0; |
| } |
| |
| static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); |
| |
| /** |
| * create_bm_block_list - create a list of block bitmap objects |
| * @pages - number of pages to track |
| * @list - list to put the allocated blocks into |
| * @ca - chain allocator to be used for allocating memory |
| */ |
| static int create_bm_block_list(unsigned long pages, |
| struct list_head *list, |
| struct chain_allocator *ca) |
| { |
| unsigned int nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK); |
| |
| while (nr_blocks-- > 0) { |
| struct bm_block *bb; |
| |
| bb = chain_alloc(ca, sizeof(struct bm_block)); |
| if (!bb) |
| return -ENOMEM; |
| list_add(&bb->hook, list); |
| } |
| |
| return 0; |
| } |
| |
| struct mem_extent { |
| struct list_head hook; |
| unsigned long start; |
| unsigned long end; |
| }; |
| |
| /** |
| * free_mem_extents - free a list of memory extents |
| * @list - list of extents to empty |
| */ |
| static void free_mem_extents(struct list_head *list) |
| { |
| struct mem_extent *ext, *aux; |
| |
| list_for_each_entry_safe(ext, aux, list, hook) { |
| list_del(&ext->hook); |
| kfree(ext); |
| } |
| } |
| |
| /** |
| * create_mem_extents - create a list of memory extents representing |
| * contiguous ranges of PFNs |
| * @list - list to put the extents into |
| * @gfp_mask - mask to use for memory allocations |
| */ |
| static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) |
| { |
| struct zone *zone; |
| |
| INIT_LIST_HEAD(list); |
| |
| for_each_populated_zone(zone) { |
| unsigned long zone_start, zone_end; |
| struct mem_extent *ext, *cur, *aux; |
| |
| zone_start = zone->zone_start_pfn; |
| zone_end = zone->zone_start_pfn + zone->spanned_pages; |
| |
| list_for_each_entry(ext, list, hook) |
| if (zone_start <= ext->end) |
| break; |
| |
| if (&ext->hook == list || zone_end < ext->start) { |
| /* New extent is necessary */ |
| struct mem_extent *new_ext; |
| |
| new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask); |
| if (!new_ext) { |
| free_mem_extents(list); |
| return -ENOMEM; |
| } |
| new_ext->start = zone_start; |
| new_ext->end = zone_end; |
| list_add_tail(&new_ext->hook, &ext->hook); |
| continue; |
| } |
| |
| /* Merge this zone's range of PFNs with the existing one */ |
| if (zone_start < ext->start) |
| ext->start = zone_start; |
| if (zone_end > ext->end) |
| ext->end = zone_end; |
| |
| /* More merging may be possible */ |
| cur = ext; |
| list_for_each_entry_safe_continue(cur, aux, list, hook) { |
| if (zone_end < cur->start) |
| break; |
| if (zone_end < cur->end) |
| ext->end = cur->end; |
| list_del(&cur->hook); |
| kfree(cur); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * 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 list_head mem_extents; |
| struct mem_extent *ext; |
| int error; |
| |
| chain_init(&ca, gfp_mask, safe_needed); |
| INIT_LIST_HEAD(&bm->blocks); |
| |
| error = create_mem_extents(&mem_extents, gfp_mask); |
| if (error) |
| return error; |
| |
| list_for_each_entry(ext, &mem_extents, hook) { |
| struct bm_block *bb; |
| unsigned long pfn = ext->start; |
| unsigned long pages = ext->end - ext->start; |
| |
| bb = list_entry(bm->blocks.prev, struct bm_block, hook); |
| |
| error = create_bm_block_list(pages, bm->blocks.prev, &ca); |
| if (error) |
| goto Error; |
| |
| list_for_each_entry_continue(bb, &bm->blocks, hook) { |
| bb->data = get_image_page(gfp_mask, safe_needed); |
| if (!bb->data) { |
| error = -ENOMEM; |
| goto Error; |
| } |
| |
| bb->start_pfn = pfn; |
| if (pages >= BM_BITS_PER_BLOCK) { |
| pfn += BM_BITS_PER_BLOCK; |
| pages -= BM_BITS_PER_BLOCK; |
| } else { |
| /* This is executed only once in the loop */ |
| pfn += pages; |
| } |
| bb->end_pfn = pfn; |
| } |
| } |
| |
| bm->p_list = ca.chain; |
| memory_bm_position_reset(bm); |
| Exit: |
| free_mem_extents(&mem_extents); |
| return error; |
| |
| Error: |
| bm->p_list = ca.chain; |
| memory_bm_free(bm, PG_UNSAFE_CLEAR); |
| goto Exit; |
| } |
| |
| /** |
| * 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 bm_block *bb; |
| |
| list_for_each_entry(bb, &bm->blocks, hook) |
| if (bb->data) |
| free_image_page(bb->data, clear_nosave_free); |
| |
| free_list_of_pages(bm->p_list, clear_nosave_free); |
| |
| INIT_LIST_HEAD(&bm->blocks); |
| } |
| |
| /** |
| * 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 int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, |
| void **addr, unsigned int *bit_nr) |
| { |
| struct bm_block *bb; |
| |
| /* |
| * Check if the pfn corresponds to the current bitmap block and find |
| * the block where it fits if this is not the case. |
| */ |
| bb = bm->cur.block; |
| if (pfn < bb->start_pfn) |
| list_for_each_entry_continue_reverse(bb, &bm->blocks, hook) |
| if (pfn >= bb->start_pfn) |
| break; |
| |
| if (pfn >= bb->end_pfn) |
| list_for_each_entry_continue(bb, &bm->blocks, hook) |
| if (pfn >= bb->start_pfn && pfn < bb->end_pfn) |
| break; |
| |
| if (&bb->hook == &bm->blocks) |
| return -EFAULT; |
| |
| /* The block has been found */ |
| bm->cur.block = bb; |
| pfn -= bb->start_pfn; |
| bm->cur.bit = pfn + 1; |
| *bit_nr = pfn; |
| *addr = bb->data; |
| return 0; |
| } |
| |
| static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) |
| { |
| void *addr; |
| unsigned int bit; |
| int error; |
| |
| error = memory_bm_find_bit(bm, pfn, &addr, &bit); |
| BUG_ON(error); |
| set_bit(bit, addr); |
| } |
| |
| static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn) |
| { |
| void *addr; |
| unsigned int bit; |
| int error; |
| |
| error = memory_bm_find_bit(bm, pfn, &addr, &bit); |
| if (!error) |
| set_bit(bit, addr); |
| return error; |
| } |
| |
| static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) |
| { |
| void *addr; |
| unsigned int bit; |
| int error; |
| |
| error = memory_bm_find_bit(bm, pfn, &addr, &bit); |
| BUG_ON(error); |
| clear_bit(bit, addr); |
| } |
| |
| static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) |
| { |
| void *addr; |
| unsigned int bit; |
| int error; |
| |
| error = memory_bm_find_bit(bm, pfn, &addr, &bit); |
| BUG_ON(error); |
| return test_bit(bit, addr); |
| } |
| |
| static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn) |
| { |
| void *addr; |
| unsigned int bit; |
| |
| return !memory_bm_find_bit(bm, pfn, &addr, &bit); |
| } |
| |
| /** |
| * 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 bm_block *bb; |
| int bit; |
| |
| bb = bm->cur.block; |
| do { |
| bit = bm->cur.bit; |
| bit = find_next_bit(bb->data, bm_block_bits(bb), bit); |
| if (bit < bm_block_bits(bb)) |
| goto Return_pfn; |
| |
| bb = list_entry(bb->hook.next, struct bm_block, hook); |
| bm->cur.block = bb; |
| bm->cur.bit = 0; |
| } while (&bb->hook != &bm->blocks); |
| |
| memory_bm_position_reset(bm); |
| return BM_END_OF_MAP; |
| |
| Return_pfn: |
| bm->cur.bit = bit + 1; |
| return bb->start_pfn + 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(sizeof(struct nosave_region)); |
| region->start_pfn = start_pfn; |
| region->end_pfn = end_pfn; |
| list_add_tail(®ion->list, &nosave_regions); |
| Report: |
| printk(KERN_INFO "PM: Registered nosave memory: %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; |
| |
| pr_debug("PM: 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)) { |
| /* |
| * It is safe to ignore the result of |
| * mem_bm_set_bit_check() here, since we won't |
| * touch the PFNs for which the error is |
| * returned anyway. |
| */ |
| mem_bm_set_bit_check(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); |
| |
| pr_debug("PM: 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); |
| |
| pr_debug("PM: 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_populated_zone(zone) |
| if (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(struct zone *zone, unsigned long pfn) |
| { |
| struct page *page; |
| |
| if (!pfn_valid(pfn)) |
| return NULL; |
| |
| page = pfn_to_page(pfn); |
| if (page_zone(page) != zone) |
| return NULL; |
| |
| 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. |
| */ |
| |
| static unsigned int count_highmem_pages(void) |
| { |
| struct zone *zone; |
| unsigned int n = 0; |
| |
| for_each_populated_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(zone, pfn)) |
| n++; |
| } |
| return n; |
| } |
| #else |
| static inline void *saveable_highmem_page(struct zone *z, unsigned long p) |
| { |
| return NULL; |
| } |
| #endif /* CONFIG_HIGHMEM */ |
| |
| /** |
| * saveable_page - 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(struct zone *zone, unsigned long pfn) |
| { |
| struct page *page; |
| |
| if (!pfn_valid(pfn)) |
| return NULL; |
| |
| page = pfn_to_page(pfn); |
| if (page_zone(page) != zone) |
| return NULL; |
| |
| BUG_ON(PageHighMem(page)); |
| |
| if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) |
| return NULL; |
| |
| if (PageReserved(page) |
| && (!kernel_page_present(page) || pfn_is_nosave(pfn))) |
| return NULL; |
| |
| return page; |
| } |
| |
| /** |
| * count_data_pages - compute the total number of saveable non-highmem |
| * pages. |
| */ |
| |
| static unsigned int count_data_pages(void) |
| { |
| struct zone *zone; |
| unsigned long pfn, max_zone_pfn; |
| unsigned int n = 0; |
| |
| for_each_populated_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(zone, 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++; |
| } |
| |
| |
| /** |
| * safe_copy_page - check if the page we are going to copy is marked as |
| * present in the kernel page tables (this always is the case if |
| * CONFIG_DEBUG_PAGEALLOC is not set and in that case |
| * kernel_page_present() always returns 'true'). |
| */ |
| static void safe_copy_page(void *dst, struct page *s_page) |
| { |
| if (kernel_page_present(s_page)) { |
| do_copy_page(dst, page_address(s_page)); |
| } else { |
| kernel_map_pages(s_page, 1, 1); |
| do_copy_page(dst, page_address(s_page)); |
| kernel_map_pages(s_page, 1, 0); |
| } |
| } |
| |
| |
| #ifdef CONFIG_HIGHMEM |
| static inline struct page * |
| page_is_saveable(struct zone *zone, unsigned long pfn) |
| { |
| return is_highmem(zone) ? |
| saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn); |
| } |
| |
| static 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 { |
| if (PageHighMem(d_page)) { |
| /* Page pointed to by src may contain some kernel |
| * data modified by kmap_atomic() |
| */ |
| safe_copy_page(buffer, s_page); |
| dst = kmap_atomic(d_page, KM_USER0); |
| memcpy(dst, buffer, PAGE_SIZE); |
| kunmap_atomic(dst, KM_USER0); |
| } else { |
| safe_copy_page(page_address(d_page), s_page); |
| } |
| } |
| } |
| #else |
| #define page_is_saveable(zone, pfn) saveable_page(zone, pfn) |
| |
| static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) |
| { |
| safe_copy_page(page_address(pfn_to_page(dst_pfn)), |
| 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_populated_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; |
| /* |
| * Numbers of normal and highmem page frames allocated for hibernation image |
| * before suspending devices. |
| */ |
| unsigned int alloc_normal, alloc_highmem; |
| /* |
| * Memory bitmap used for marking saveable pages (during hibernation) or |
| * hibernation image pages (during restore) |
| */ |
| static struct memory_bitmap orig_bm; |
| /* |
| * Memory bitmap used during hibernation for marking allocated page frames that |
| * will contain copies of saveable pages. During restore it is initially used |
| * for marking hibernation image pages, but then the set bits from it are |
| * duplicated in @orig_bm and it is released. On highmem systems it is next |
| * used for marking "safe" highmem pages, but it has to be reinitialized for |
| * this purpose. |
| */ |
| static struct memory_bitmap copy_bm; |
| |
| /** |
| * 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_populated_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; |
| alloc_normal = 0; |
| alloc_highmem = 0; |
| } |
| |
| /* Helper functions used for the shrinking of memory. */ |
| |
| #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN) |
| |
| /** |
| * preallocate_image_pages - Allocate a number of pages for hibernation image |
| * @nr_pages: Number of page frames to allocate. |
| * @mask: GFP flags to use for the allocation. |
| * |
| * Return value: Number of page frames actually allocated |
| */ |
| static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask) |
| { |
| unsigned long nr_alloc = 0; |
| |
| while (nr_pages > 0) { |
| struct page *page; |
| |
| page = alloc_image_page(mask); |
| if (!page) |
| break; |
| memory_bm_set_bit(©_bm, page_to_pfn(page)); |
| if (PageHighMem(page)) |
| alloc_highmem++; |
| else |
| alloc_normal++; |
| nr_pages--; |
| nr_alloc++; |
| } |
| |
| return nr_alloc; |
| } |
| |
| static unsigned long preallocate_image_memory(unsigned long nr_pages) |
| { |
| return preallocate_image_pages(nr_pages, GFP_IMAGE); |
| } |
| |
| #ifdef CONFIG_HIGHMEM |
| static unsigned long preallocate_image_highmem(unsigned long nr_pages) |
| { |
| return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM); |
| } |
| |
| /** |
| * __fraction - Compute (an approximation of) x * (multiplier / base) |
| */ |
| static unsigned long __fraction(u64 x, u64 multiplier, u64 base) |
| { |
| x *= multiplier; |
| do_div(x, base); |
| return (unsigned long)x; |
| } |
| |
| static unsigned long preallocate_highmem_fraction(unsigned long nr_pages, |
| unsigned long highmem, |
| unsigned long total) |
| { |
| unsigned long alloc = __fraction(nr_pages, highmem, total); |
| |
| return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM); |
| } |
| #else /* CONFIG_HIGHMEM */ |
| static inline unsigned long preallocate_image_highmem(unsigned long nr_pages) |
| { |
| return 0; |
| } |
| |
| static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, |
| unsigned long highmem, |
| unsigned long total) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_HIGHMEM */ |
| |
| /** |
| * free_unnecessary_pages - Release preallocated pages not needed for the image |
| */ |
| static void free_unnecessary_pages(void) |
| { |
| unsigned long save_highmem, to_free_normal, to_free_highmem; |
| |
| to_free_normal = alloc_normal - count_data_pages(); |
| save_highmem = count_highmem_pages(); |
| if (alloc_highmem > save_highmem) { |
| to_free_highmem = alloc_highmem - save_highmem; |
| } else { |
| to_free_highmem = 0; |
| to_free_normal -= save_highmem - alloc_highmem; |
| } |
| |
| memory_bm_position_reset(©_bm); |
| |
| while (to_free_normal > 0 || to_free_highmem > 0) { |
| unsigned long pfn = memory_bm_next_pfn(©_bm); |
| struct page *page = pfn_to_page(pfn); |
| |
| if (PageHighMem(page)) { |
| if (!to_free_highmem) |
| continue; |
| to_free_highmem--; |
| alloc_highmem--; |
| } else { |
| if (!to_free_normal) |
| continue; |
| to_free_normal--; |
| alloc_normal--; |
| } |
| memory_bm_clear_bit(©_bm, pfn); |
| swsusp_unset_page_forbidden(page); |
| swsusp_unset_page_free(page); |
| __free_page(page); |
| } |
| } |
| |
| /** |
| * minimum_image_size - Estimate the minimum acceptable size of an image |
| * @saveable: Number of saveable pages in the system. |
| * |
| * We want to avoid attempting to free too much memory too hard, so estimate the |
| * minimum acceptable size of a hibernation image to use as the lower limit for |
| * preallocating memory. |
| * |
| * We assume that the minimum image size should be proportional to |
| * |
| * [number of saveable pages] - [number of pages that can be freed in theory] |
| * |
| * where the second term is the sum of (1) reclaimable slab pages, (2) active |
| * and (3) inactive anonymouns pages, (4) active and (5) inactive file pages, |
| * minus mapped file pages. |
| */ |
| static unsigned long minimum_image_size(unsigned long saveable) |
| { |
| unsigned long size; |
| |
| size = global_page_state(NR_SLAB_RECLAIMABLE) |
| + global_page_state(NR_ACTIVE_ANON) |
| + global_page_state(NR_INACTIVE_ANON) |
| + global_page_state(NR_ACTIVE_FILE) |
| + global_page_state(NR_INACTIVE_FILE) |
| - global_page_state(NR_FILE_MAPPED); |
| |
| return saveable <= size ? 0 : saveable - size; |
| } |
| |
| /** |
| * hibernate_preallocate_memory - Preallocate memory for hibernation image |
| * |
| * To create a hibernation image it is necessary to make a copy of every page |
| * frame in use. We also need a number of page frames to be free during |
| * hibernation for allocations made while saving the image and for device |
| * drivers, in case they need to allocate memory from their hibernation |
| * callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES, |
| * respectively, both of which are rough estimates). To make this happen, we |
| * compute the total number of available page frames and allocate at least |
| * |
| * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES |
| * |
| * of them, which corresponds to the maximum size of a hibernation image. |
| * |
| * If image_size is set below the number following from the above formula, |
| * the preallocation of memory is continued until the total number of saveable |
| * pages in the system is below the requested image size or the minimum |
| * acceptable image size returned by minimum_image_size(), whichever is greater. |
| */ |
| int hibernate_preallocate_memory(void) |
| { |
| struct zone *zone; |
| unsigned long saveable, size, max_size, count, highmem, pages = 0; |
| unsigned long alloc, save_highmem, pages_highmem; |
| struct timeval start, stop; |
| int error; |
| |
| printk(KERN_INFO "PM: Preallocating image memory... "); |
| do_gettimeofday(&start); |
| |
| error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); |
| if (error) |
| goto err_out; |
| |
| error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY); |
| if (error) |
| goto err_out; |
| |
| alloc_normal = 0; |
| alloc_highmem = 0; |
| |
| /* Count the number of saveable data pages. */ |
| save_highmem = count_highmem_pages(); |
| saveable = count_data_pages(); |
| |
| /* |
| * Compute the total number of page frames we can use (count) and the |
| * number of pages needed for image metadata (size). |
| */ |
| count = saveable; |
| saveable += save_highmem; |
| highmem = save_highmem; |
| size = 0; |
| for_each_populated_zone(zone) { |
| size += snapshot_additional_pages(zone); |
| if (is_highmem(zone)) |
| highmem += zone_page_state(zone, NR_FREE_PAGES); |
| else |
| count += zone_page_state(zone, NR_FREE_PAGES); |
| } |
| count += highmem; |
| count -= totalreserve_pages; |
| |
| /* Compute the maximum number of saveable pages to leave in memory. */ |
| max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES; |
| size = DIV_ROUND_UP(image_size, PAGE_SIZE); |
| if (size > max_size) |
| size = max_size; |
| /* |
| * If the maximum is not less than the current number of saveable pages |
| * in memory, allocate page frames for the image and we're done. |
| */ |
| if (size >= saveable) { |
| pages = preallocate_image_highmem(save_highmem); |
| pages += preallocate_image_memory(saveable - pages); |
| goto out; |
| } |
| |
| /* Estimate the minimum size of the image. */ |
| pages = minimum_image_size(saveable); |
| if (size < pages) |
| size = min_t(unsigned long, pages, max_size); |
| |
| /* |
| * Let the memory management subsystem know that we're going to need a |
| * large number of page frames to allocate and make it free some memory. |
| * NOTE: If this is not done, performance will be hurt badly in some |
| * test cases. |
| */ |
| shrink_all_memory(saveable - size); |
| |
| /* |
| * The number of saveable pages in memory was too high, so apply some |
| * pressure to decrease it. First, make room for the largest possible |
| * image and fail if that doesn't work. Next, try to decrease the size |
| * of the image as much as indicated by 'size' using allocations from |
| * highmem and non-highmem zones separately. |
| */ |
| pages_highmem = preallocate_image_highmem(highmem / 2); |
| alloc = (count - max_size) - pages_highmem; |
| pages = preallocate_image_memory(alloc); |
| if (pages < alloc) |
| goto err_out; |
| size = max_size - size; |
| alloc = size; |
| size = preallocate_highmem_fraction(size, highmem, count); |
| pages_highmem += size; |
| alloc -= size; |
| pages += preallocate_image_memory(alloc); |
| pages += pages_highmem; |
| |
| /* |
| * We only need as many page frames for the image as there are saveable |
| * pages in memory, but we have allocated more. Release the excessive |
| * ones now. |
| */ |
| free_unnecessary_pages(); |
| |
| out: |
| do_gettimeofday(&stop); |
| printk(KERN_CONT "done (allocated %lu pages)\n", pages); |
| swsusp_show_speed(&start, &stop, pages, "Allocated"); |
| |
| return 0; |
| |
| err_out: |
| printk(KERN_CONT "\n"); |
| swsusp_free(); |
| return -ENOMEM; |
| } |
| |
| #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() + alloc_highmem; |
| |
| 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 = alloc_normal; |
| |
| for_each_populated_zone(zone) |
| if (!is_highmem(zone)) |
| free += zone_page_state(zone, NR_FREE_PAGES); |
| |
| nr_pages += count_pages_for_highmem(nr_highmem); |
| pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n", |
| nr_pages, PAGES_FOR_IO, free); |
| |
| return free > nr_pages + PAGES_FOR_IO; |
| } |
| |
| #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_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_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 = 0; |
| |
| if (nr_highmem > 0) { |
| error = get_highmem_buffer(PG_ANY); |
| if (error) |
| goto err_out; |
| if (nr_highmem > alloc_highmem) { |
| nr_highmem -= alloc_highmem; |
| nr_pages += alloc_highmem_pages(copy_bm, nr_highmem); |
| } |
| } |
| if (nr_pages > alloc_normal) { |
| nr_pages -= alloc_normal; |
| while (nr_pages-- > 0) { |
| struct page *page; |
| |
| page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); |
| if (!page) |
| goto err_out; |
| memory_bm_set_bit(copy_bm, page_to_pfn(page)); |
| } |
| } |
| |
| return 0; |
| |
| err_out: |
| swsusp_free(); |
| return error; |
| } |
| |
| asmlinkage int swsusp_save(void) |
| { |
| unsigned int nr_pages, nr_highmem; |
| |
| printk(KERN_INFO "PM: Creating hibernation image:\n"); |
| |
| drain_local_pages(NULL); |
| nr_pages = count_data_pages(); |
| nr_highmem = count_highmem_pages(); |
| printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem); |
| |
| if (!enough_free_mem(nr_pages, nr_highmem)) { |
| printk(KERN_ERR "PM: Not enough free memory\n"); |
| return -ENOMEM; |
| } |
| |
| if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) { |
| printk(KERN_ERR "PM: Memory allocation failed\n"); |
| return -ENOMEM; |
| } |
| |
| /* During allocating of suspend pagedir, new cold pages may appear. |
| * Kill them. |
| */ |
| drain_local_pages(NULL); |
| 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(KERN_INFO "PM: Hibernation image created (%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 */ |
| |
| unsigned long snapshot_get_image_size(void) |
| { |
| return nr_copy_pages + nr_meta_pages + 1; |
| } |
| |
| 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 = snapshot_get_image_size(); |
| 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. |
| * |
| * 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 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) |
| { |
| 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->cur) { |
| 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); |
| } else 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->cur++; |
| return PAGE_SIZE; |
| } |
| |
| /** |
| * 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_populated_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 "PM: Image 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 int 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; |
| |
| if (memory_bm_pfn_present(bm, buf[j])) |
| memory_bm_set_bit(bm, buf[j]); |
| else |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| |
| /* 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 ERR_PTR(-ENOMEM); |
| } |
| 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 ERR_PTR(-EINVAL); |
| } |
| |
| 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; |
| unsigned long pfn = memory_bm_next_pfn(bm); |
| |
| if (pfn == BM_END_OF_MAP) |
| return ERR_PTR(-EFAULT); |
| |
| page = pfn_to_page(pfn); |
| 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 ERR_PTR(-ENOMEM); |
| } |
| 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. |
| * |
| * 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 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) |
| { |
| static struct chain_allocator ca; |
| int error = 0; |
| |
| /* Check if we have already loaded the entire image */ |
| if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) |
| return 0; |
| |
| handle->sync_read = 1; |
| |
| if (!handle->cur) { |
| 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; |
| } else if (handle->cur == 1) { |
| error = load_header(buffer); |
| if (error) |
| return error; |
| |
| error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); |
| if (error) |
| return error; |
| |
| } else if (handle->cur <= nr_meta_pages + 1) { |
| error = unpack_orig_pfns(buffer, ©_bm); |
| if (error) |
| return error; |
| |
| if (handle->cur == nr_meta_pages + 1) { |
| 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 (IS_ERR(handle->buffer)) |
| return PTR_ERR(handle->buffer); |
| } |
| } else { |
| copy_last_highmem_page(); |
| handle->buffer = get_buffer(&orig_bm, &ca); |
| if (IS_ERR(handle->buffer)) |
| return PTR_ERR(handle->buffer); |
| if (handle->buffer != buffer) |
| handle->sync_read = 0; |
| } |
| handle->cur++; |
| return PAGE_SIZE; |
| } |
| |
| /** |
| * 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->cur > 1 && 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 */ |