| /* |
| * 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 <linux/compiler.h> |
| #include <linux/ktime.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" |
| |
| #ifdef CONFIG_DEBUG_RODATA |
| static bool hibernate_restore_protection; |
| static bool hibernate_restore_protection_active; |
| |
| void enable_restore_image_protection(void) |
| { |
| hibernate_restore_protection = true; |
| } |
| |
| static inline void hibernate_restore_protection_begin(void) |
| { |
| hibernate_restore_protection_active = hibernate_restore_protection; |
| } |
| |
| static inline void hibernate_restore_protection_end(void) |
| { |
| hibernate_restore_protection_active = false; |
| } |
| |
| static inline void hibernate_restore_protect_page(void *page_address) |
| { |
| if (hibernate_restore_protection_active) |
| set_memory_ro((unsigned long)page_address, 1); |
| } |
| |
| static inline void hibernate_restore_unprotect_page(void *page_address) |
| { |
| if (hibernate_restore_protection_active) |
| set_memory_rw((unsigned long)page_address, 1); |
| } |
| #else |
| static inline void hibernate_restore_protection_begin(void) {} |
| static inline void hibernate_restore_protection_end(void) {} |
| static inline void hibernate_restore_protect_page(void *page_address) {} |
| static inline void hibernate_restore_unprotect_page(void *page_address) {} |
| #endif /* CONFIG_DEBUG_RODATA */ |
| |
| static int swsusp_page_is_free(struct page *); |
| static void swsusp_set_page_forbidden(struct page *); |
| static void swsusp_unset_page_forbidden(struct page *); |
| |
| /* |
| * Number of bytes to reserve for memory allocations made by device drivers |
| * from their ->freeze() and ->freeze_noirq() callbacks so that they don't |
| * cause image creation to fail (tunable via /sys/power/reserved_size). |
| */ |
| unsigned long reserved_size; |
| |
| void __init hibernate_reserved_size_init(void) |
| { |
| reserved_size = SPARE_PAGES * PAGE_SIZE; |
| } |
| |
| /* |
| * 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; |
| |
| void __init hibernate_image_size_init(void) |
| { |
| image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; |
| } |
| |
| /* |
| * 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; |
| |
| /* 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]; |
| } __packed; |
| |
| /* |
| * List of "safe" pages (ie. pages that were not used by the image kernel |
| * before hibernation) that may be used as temporary storage for image kernel |
| * memory contents. |
| */ |
| static struct linked_page *safe_pages_list; |
| |
| /* Pointer to an auxiliary buffer (1 page) */ |
| static void *buffer; |
| |
| #define PG_ANY 0 |
| #define PG_SAFE 1 |
| #define PG_UNSAFE_CLEAR 1 |
| #define PG_UNSAFE_KEEP 0 |
| |
| static unsigned int allocated_unsafe_pages; |
| |
| /** |
| * get_image_page - Allocate a page for a hibernation image. |
| * @gfp_mask: GFP mask for the allocation. |
| * @safe_needed: Get pages that were not used before hibernation (restore only) |
| * |
| * During image restoration, for storing the PBE list and the image data, we can |
| * only use memory pages that do not conflict with the pages used before |
| * hibernation. The "unsafe" pages have PageNosaveFree set and we count them |
| * using allocated_unsafe_pages. |
| * |
| * Each allocated image page is marked as PageNosave and PageNosaveFree so that |
| * swsusp_free() can release it. |
| */ |
| 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; |
| } |
| |
| static void *__get_safe_page(gfp_t gfp_mask) |
| { |
| if (safe_pages_list) { |
| void *ret = safe_pages_list; |
| |
| safe_pages_list = safe_pages_list->next; |
| memset(ret, 0, PAGE_SIZE); |
| return ret; |
| } |
| return get_image_page(gfp_mask, PG_SAFE); |
| } |
| |
| unsigned long get_safe_page(gfp_t gfp_mask) |
| { |
| return (unsigned long)__get_safe_page(gfp_mask); |
| } |
| |
| 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; |
| } |
| |
| static void recycle_safe_page(void *page_address) |
| { |
| struct linked_page *lp = page_address; |
| |
| lp->next = safe_pages_list; |
| safe_pages_list = lp; |
| } |
| |
| /** |
| * free_image_page - Free a page allocated for hibernation image. |
| * @addr: Address of the page to free. |
| * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page. |
| * |
| * The page to free should have been allocated by get_image_page() (page flags |
| * set by it are affected). |
| */ |
| 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); |
| } |
| |
| 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 = ca->safe_needed ? __get_safe_page(ca->gfp_mask) : |
| get_image_page(ca->gfp_mask, PG_ANY); |
| 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. |
| * |
| * The memory bitmap is organized as a radix tree to guarantee fast random |
| * access to the bits. There is one radix tree for each zone (as returned |
| * from create_mem_extents). |
| * |
| * One radix tree is represented by one struct mem_zone_bm_rtree. There are |
| * two linked lists for the nodes of the tree, one for the inner nodes and |
| * one for the leave nodes. The linked leave nodes are used for fast linear |
| * access of the memory bitmap. |
| * |
| * The struct rtree_node represents one node of the radix tree. |
| */ |
| |
| #define BM_END_OF_MAP (~0UL) |
| |
| #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE) |
| #define BM_BLOCK_SHIFT (PAGE_SHIFT + 3) |
| #define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1) |
| |
| /* |
| * struct rtree_node is a wrapper struct to link the nodes |
| * of the rtree together for easy linear iteration over |
| * bits and easy freeing |
| */ |
| struct rtree_node { |
| struct list_head list; |
| unsigned long *data; |
| }; |
| |
| /* |
| * struct mem_zone_bm_rtree represents a bitmap used for one |
| * populated memory zone. |
| */ |
| struct mem_zone_bm_rtree { |
| struct list_head list; /* Link Zones together */ |
| struct list_head nodes; /* Radix Tree inner nodes */ |
| struct list_head leaves; /* Radix Tree leaves */ |
| unsigned long start_pfn; /* Zone start page frame */ |
| unsigned long end_pfn; /* Zone end page frame + 1 */ |
| struct rtree_node *rtree; /* Radix Tree Root */ |
| int levels; /* Number of Radix Tree Levels */ |
| unsigned int blocks; /* Number of Bitmap Blocks */ |
| }; |
| |
| /* strcut bm_position is used for browsing memory bitmaps */ |
| |
| struct bm_position { |
| struct mem_zone_bm_rtree *zone; |
| struct rtree_node *node; |
| unsigned long node_pfn; |
| int node_bit; |
| }; |
| |
| struct memory_bitmap { |
| struct list_head zones; |
| 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 */ |
| |
| #define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long)) |
| #if BITS_PER_LONG == 32 |
| #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2) |
| #else |
| #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3) |
| #endif |
| #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1) |
| |
| /** |
| * alloc_rtree_node - Allocate a new node and add it to the radix tree. |
| * |
| * This function is used to allocate inner nodes as well as the |
| * leave nodes of the radix tree. It also adds the node to the |
| * corresponding linked list passed in by the *list parameter. |
| */ |
| static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed, |
| struct chain_allocator *ca, |
| struct list_head *list) |
| { |
| struct rtree_node *node; |
| |
| node = chain_alloc(ca, sizeof(struct rtree_node)); |
| if (!node) |
| return NULL; |
| |
| node->data = get_image_page(gfp_mask, safe_needed); |
| if (!node->data) |
| return NULL; |
| |
| list_add_tail(&node->list, list); |
| |
| return node; |
| } |
| |
| /** |
| * add_rtree_block - Add a new leave node to the radix tree. |
| * |
| * The leave nodes need to be allocated in order to keep the leaves |
| * linked list in order. This is guaranteed by the zone->blocks |
| * counter. |
| */ |
| static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask, |
| int safe_needed, struct chain_allocator *ca) |
| { |
| struct rtree_node *node, *block, **dst; |
| unsigned int levels_needed, block_nr; |
| int i; |
| |
| block_nr = zone->blocks; |
| levels_needed = 0; |
| |
| /* How many levels do we need for this block nr? */ |
| while (block_nr) { |
| levels_needed += 1; |
| block_nr >>= BM_RTREE_LEVEL_SHIFT; |
| } |
| |
| /* Make sure the rtree has enough levels */ |
| for (i = zone->levels; i < levels_needed; i++) { |
| node = alloc_rtree_node(gfp_mask, safe_needed, ca, |
| &zone->nodes); |
| if (!node) |
| return -ENOMEM; |
| |
| node->data[0] = (unsigned long)zone->rtree; |
| zone->rtree = node; |
| zone->levels += 1; |
| } |
| |
| /* Allocate new block */ |
| block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves); |
| if (!block) |
| return -ENOMEM; |
| |
| /* Now walk the rtree to insert the block */ |
| node = zone->rtree; |
| dst = &zone->rtree; |
| block_nr = zone->blocks; |
| for (i = zone->levels; i > 0; i--) { |
| int index; |
| |
| if (!node) { |
| node = alloc_rtree_node(gfp_mask, safe_needed, ca, |
| &zone->nodes); |
| if (!node) |
| return -ENOMEM; |
| *dst = node; |
| } |
| |
| index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT); |
| index &= BM_RTREE_LEVEL_MASK; |
| dst = (struct rtree_node **)&((*dst)->data[index]); |
| node = *dst; |
| } |
| |
| zone->blocks += 1; |
| *dst = block; |
| |
| return 0; |
| } |
| |
| static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, |
| int clear_nosave_free); |
| |
| /** |
| * create_zone_bm_rtree - Create a radix tree for one zone. |
| * |
| * Allocated the mem_zone_bm_rtree structure and initializes it. |
| * This function also allocated and builds the radix tree for the |
| * zone. |
| */ |
| static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask, |
| int safe_needed, |
| struct chain_allocator *ca, |
| unsigned long start, |
| unsigned long end) |
| { |
| struct mem_zone_bm_rtree *zone; |
| unsigned int i, nr_blocks; |
| unsigned long pages; |
| |
| pages = end - start; |
| zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree)); |
| if (!zone) |
| return NULL; |
| |
| INIT_LIST_HEAD(&zone->nodes); |
| INIT_LIST_HEAD(&zone->leaves); |
| zone->start_pfn = start; |
| zone->end_pfn = end; |
| nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK); |
| |
| for (i = 0; i < nr_blocks; i++) { |
| if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) { |
| free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR); |
| return NULL; |
| } |
| } |
| |
| return zone; |
| } |
| |
| /** |
| * free_zone_bm_rtree - Free the memory of the radix tree. |
| * |
| * Free all node pages of the radix tree. The mem_zone_bm_rtree |
| * structure itself is not freed here nor are the rtree_node |
| * structs. |
| */ |
| static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, |
| int clear_nosave_free) |
| { |
| struct rtree_node *node; |
| |
| list_for_each_entry(node, &zone->nodes, list) |
| free_image_page(node->data, clear_nosave_free); |
| |
| list_for_each_entry(node, &zone->leaves, list) |
| free_image_page(node->data, clear_nosave_free); |
| } |
| |
| static void memory_bm_position_reset(struct memory_bitmap *bm) |
| { |
| bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree, |
| list); |
| bm->cur.node = list_entry(bm->cur.zone->leaves.next, |
| struct rtree_node, list); |
| bm->cur.node_pfn = 0; |
| bm->cur.node_bit = 0; |
| } |
| |
| static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); |
| |
| 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 free. |
| */ |
| 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. |
| * @list: List to put the extents into. |
| * @gfp_mask: Mask to use for memory allocations. |
| * |
| * The extents represent contiguous ranges of PFNs. |
| */ |
| 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_end_pfn(zone); |
| |
| 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->zones); |
| |
| error = create_mem_extents(&mem_extents, gfp_mask); |
| if (error) |
| return error; |
| |
| list_for_each_entry(ext, &mem_extents, hook) { |
| struct mem_zone_bm_rtree *zone; |
| |
| zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca, |
| ext->start, ext->end); |
| if (!zone) { |
| error = -ENOMEM; |
| goto Error; |
| } |
| list_add_tail(&zone->list, &bm->zones); |
| } |
| |
| 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: Memory bitmap. |
| */ |
| static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) |
| { |
| struct mem_zone_bm_rtree *zone; |
| |
| list_for_each_entry(zone, &bm->zones, list) |
| free_zone_bm_rtree(zone, clear_nosave_free); |
| |
| free_list_of_pages(bm->p_list, clear_nosave_free); |
| |
| INIT_LIST_HEAD(&bm->zones); |
| } |
| |
| /** |
| * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap. |
| * |
| * Find the bit in memory bitmap @bm that corresponds to the given PFN. |
| * The cur.zone, cur.block and cur.node_pfn members of @bm are updated. |
| * |
| * Walk the radix tree to find the page containing the bit that represents @pfn |
| * and return the position of the bit in @addr and @bit_nr. |
| */ |
| static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, |
| void **addr, unsigned int *bit_nr) |
| { |
| struct mem_zone_bm_rtree *curr, *zone; |
| struct rtree_node *node; |
| int i, block_nr; |
| |
| zone = bm->cur.zone; |
| |
| if (pfn >= zone->start_pfn && pfn < zone->end_pfn) |
| goto zone_found; |
| |
| zone = NULL; |
| |
| /* Find the right zone */ |
| list_for_each_entry(curr, &bm->zones, list) { |
| if (pfn >= curr->start_pfn && pfn < curr->end_pfn) { |
| zone = curr; |
| break; |
| } |
| } |
| |
| if (!zone) |
| return -EFAULT; |
| |
| zone_found: |
| /* |
| * We have found the zone. Now walk the radix tree to find the leaf node |
| * for our PFN. |
| */ |
| node = bm->cur.node; |
| if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn) |
| goto node_found; |
| |
| node = zone->rtree; |
| block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT; |
| |
| for (i = zone->levels; i > 0; i--) { |
| int index; |
| |
| index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT); |
| index &= BM_RTREE_LEVEL_MASK; |
| BUG_ON(node->data[index] == 0); |
| node = (struct rtree_node *)node->data[index]; |
| } |
| |
| node_found: |
| /* Update last position */ |
| bm->cur.zone = zone; |
| bm->cur.node = node; |
| bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK; |
| |
| /* Set return values */ |
| *addr = node->data; |
| *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK; |
| |
| 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 void memory_bm_clear_current(struct memory_bitmap *bm) |
| { |
| int bit; |
| |
| bit = max(bm->cur.node_bit - 1, 0); |
| clear_bit(bit, bm->cur.node->data); |
| } |
| |
| 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); |
| } |
| |
| /* |
| * rtree_next_node - Jump to the next leaf node. |
| * |
| * Set the position to the beginning of the next node in the |
| * memory bitmap. This is either the next node in the current |
| * zone's radix tree or the first node in the radix tree of the |
| * next zone. |
| * |
| * Return true if there is a next node, false otherwise. |
| */ |
| static bool rtree_next_node(struct memory_bitmap *bm) |
| { |
| if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) { |
| bm->cur.node = list_entry(bm->cur.node->list.next, |
| struct rtree_node, list); |
| bm->cur.node_pfn += BM_BITS_PER_BLOCK; |
| bm->cur.node_bit = 0; |
| touch_softlockup_watchdog(); |
| return true; |
| } |
| |
| /* No more nodes, goto next zone */ |
| if (!list_is_last(&bm->cur.zone->list, &bm->zones)) { |
| bm->cur.zone = list_entry(bm->cur.zone->list.next, |
| struct mem_zone_bm_rtree, list); |
| bm->cur.node = list_entry(bm->cur.zone->leaves.next, |
| struct rtree_node, list); |
| bm->cur.node_pfn = 0; |
| bm->cur.node_bit = 0; |
| return true; |
| } |
| |
| /* No more zones */ |
| return false; |
| } |
| |
| /** |
| * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap. |
| * @bm: Memory bitmap. |
| * |
| * Starting from the last returned position this function searches for the next |
| * set bit in @bm and returns the PFN represented by it. If no more bits are |
| * set, BM_END_OF_MAP is returned. |
| * |
| * It is required to run memory_bm_position_reset() before the first call to |
| * this function for the given memory bitmap. |
| */ |
| static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) |
| { |
| unsigned long bits, pfn, pages; |
| int bit; |
| |
| do { |
| pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn; |
| bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK); |
| bit = find_next_bit(bm->cur.node->data, bits, |
| bm->cur.node_bit); |
| if (bit < bits) { |
| pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit; |
| bm->cur.node_bit = bit + 1; |
| return pfn; |
| } |
| } while (rtree_next_node(bm)); |
| |
| return BM_END_OF_MAP; |
| } |
| |
| /* |
| * This structure represents a range of page frames the contents of which |
| * should not be saved during hibernation. |
| */ |
| struct nosave_region { |
| struct list_head list; |
| unsigned long start_pfn; |
| unsigned long end_pfn; |
| }; |
| |
| static LIST_HEAD(nosave_regions); |
| |
| static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone) |
| { |
| struct rtree_node *node; |
| |
| list_for_each_entry(node, &zone->nodes, list) |
| recycle_safe_page(node->data); |
| |
| list_for_each_entry(node, &zone->leaves, list) |
| recycle_safe_page(node->data); |
| } |
| |
| static void memory_bm_recycle(struct memory_bitmap *bm) |
| { |
| struct mem_zone_bm_rtree *zone; |
| struct linked_page *p_list; |
| |
| list_for_each_entry(zone, &bm->zones, list) |
| recycle_zone_bm_rtree(zone); |
| |
| p_list = bm->p_list; |
| while (p_list) { |
| struct linked_page *lp = p_list; |
| |
| p_list = lp->next; |
| recycle_safe_page(lp); |
| } |
| } |
| |
| /** |
| * register_nosave_region - Register a region of unsaveable memory. |
| * |
| * Register a range of page frames the contents of which should not be saved |
| * during hibernation (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 = memblock_virt_alloc(sizeof(struct nosave_region), 0); |
| } |
| 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: [mem %#010llx-%#010llx]\n", |
| (unsigned long long) start_pfn << PAGE_SHIFT, |
| ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); |
| } |
| |
| /* |
| * 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 - Mark pages that should not be saved. |
| * @bm: Memory bitmap. |
| * |
| * Set the bits in @bm that correspond to the page frames the contents of which |
| * should not be saved. |
| */ |
| 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: [mem %#010llx-%#010llx]\n", |
| (unsigned long long) region->start_pfn << PAGE_SHIFT, |
| ((unsigned long long) region->end_pfn << PAGE_SHIFT) |
| - 1); |
| |
| 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 to hold basic page information. |
| * |
| * Create bitmaps needed for marking page frames that should not be saved and |
| * free page frames. The forbidden_pages_map and free_pages_map pointers are |
| * only modified if everything goes well, because we don't want the bits to be |
| * touched before both bitmaps are set up. |
| */ |
| int create_basic_memory_bitmaps(void) |
| { |
| struct memory_bitmap *bm1, *bm2; |
| int error = 0; |
| |
| if (forbidden_pages_map && free_pages_map) |
| return 0; |
| else |
| 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 holding basic information. |
| * |
| * 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; |
| |
| if (WARN_ON(!(forbidden_pages_map && free_pages_map))) |
| return; |
| |
| 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 extra pages needed. |
| * @zone: Memory zone to carry out the computation for. |
| * |
| * Estimate the number of additional pages needed for setting up a hibernation |
| * image data structures for @zone (usually, the returned value is greater than |
| * the exact number). |
| */ |
| unsigned int snapshot_additional_pages(struct zone *zone) |
| { |
| unsigned int rtree, nodes; |
| |
| rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); |
| rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node), |
| LINKED_PAGE_DATA_SIZE); |
| while (nodes > 1) { |
| nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL); |
| rtree += nodes; |
| } |
| |
| return 2 * rtree; |
| } |
| |
| #ifdef CONFIG_HIGHMEM |
| /** |
| * count_free_highmem_pages - Compute the total number of free highmem pages. |
| * |
| * The returned number is 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 - Check if a highmem page is saveable. |
| * |
| * Determine whether a highmem page should be included in a hibernation image. |
| * |
| * We should save the page if it isn't Nosave or NosaveFree, or Reserved, |
| * and it isn't 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; |
| |
| if (page_is_guard(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_end_pfn(zone); |
| 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 - Check if the given page is saveable. |
| * |
| * Determine whether a non-highmem page should be included in a hibernation |
| * 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 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; |
| |
| if (page_is_guard(page)) |
| 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_end_pfn(zone); |
| 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 - Copy a page in a safe way. |
| * |
| * 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); |
| dst = kmap_atomic(d_page); |
| do_copy_page(dst, src); |
| kunmap_atomic(dst); |
| kunmap_atomic(src); |
| } else { |
| if (PageHighMem(d_page)) { |
| /* |
| * The 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); |
| copy_page(dst, buffer); |
| kunmap_atomic(dst); |
| } 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_end_pfn(zone); |
| 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 hibernation image. |
| * |
| * Image pages are alocated before snapshot creation, so they need to be |
| * released after resume. |
| */ |
| void swsusp_free(void) |
| { |
| unsigned long fb_pfn, fr_pfn; |
| |
| if (!forbidden_pages_map || !free_pages_map) |
| goto out; |
| |
| memory_bm_position_reset(forbidden_pages_map); |
| memory_bm_position_reset(free_pages_map); |
| |
| loop: |
| fr_pfn = memory_bm_next_pfn(free_pages_map); |
| fb_pfn = memory_bm_next_pfn(forbidden_pages_map); |
| |
| /* |
| * Find the next bit set in both bitmaps. This is guaranteed to |
| * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP. |
| */ |
| do { |
| if (fb_pfn < fr_pfn) |
| fb_pfn = memory_bm_next_pfn(forbidden_pages_map); |
| if (fr_pfn < fb_pfn) |
| fr_pfn = memory_bm_next_pfn(free_pages_map); |
| } while (fb_pfn != fr_pfn); |
| |
| if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) { |
| struct page *page = pfn_to_page(fr_pfn); |
| |
| memory_bm_clear_current(forbidden_pages_map); |
| memory_bm_clear_current(free_pages_map); |
| hibernate_restore_unprotect_page(page_address(page)); |
| __free_page(page); |
| goto loop; |
| } |
| |
| out: |
| nr_copy_pages = 0; |
| nr_meta_pages = 0; |
| restore_pblist = NULL; |
| buffer = NULL; |
| alloc_normal = 0; |
| alloc_highmem = 0; |
| hibernate_restore_protection_end(); |
| } |
| |
| /* 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, |
| unsigned long avail_normal) |
| { |
| unsigned long alloc; |
| |
| if (avail_normal <= alloc_normal) |
| return 0; |
| |
| alloc = avail_normal - alloc_normal; |
| if (nr_pages < alloc) |
| alloc = nr_pages; |
| |
| return preallocate_image_pages(alloc, 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 unsigned long free_unnecessary_pages(void) |
| { |
| unsigned long save, to_free_normal, to_free_highmem, free; |
| |
| save = count_data_pages(); |
| if (alloc_normal >= save) { |
| to_free_normal = alloc_normal - save; |
| save = 0; |
| } else { |
| to_free_normal = 0; |
| save -= alloc_normal; |
| } |
| save += count_highmem_pages(); |
| if (alloc_highmem >= save) { |
| to_free_highmem = alloc_highmem - save; |
| } else { |
| to_free_highmem = 0; |
| save -= alloc_highmem; |
| if (to_free_normal > save) |
| to_free_normal -= save; |
| else |
| to_free_normal = 0; |
| } |
| free = to_free_normal + to_free_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); |
| } |
| |
| return free; |
| } |
| |
| /** |
| * 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 anonymous 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_node_page_state(NR_ACTIVE_ANON) |
| + global_node_page_state(NR_INACTIVE_ANON) |
| + global_node_page_state(NR_ACTIVE_FILE) |
| + global_node_page_state(NR_INACTIVE_FILE) |
| - global_node_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 (which is a rough |
| * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through |
| * /sys/power/reserved_size, respectively). 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 * DIV_ROUND_UP(reserved_size, PAGE_SIZE) |
| * |
| * 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, avail_normal; |
| ktime_t start, stop; |
| int error; |
| |
| printk(KERN_INFO "PM: Preallocating image memory... "); |
| start = ktime_get(); |
| |
| 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); |
| } |
| avail_normal = count; |
| count += highmem; |
| count -= totalreserve_pages; |
| |
| /* Add number of pages required for page keys (s390 only). */ |
| size += page_key_additional_pages(saveable); |
| |
| /* Compute the maximum number of saveable pages to leave in memory. */ |
| max_size = (count - (size + PAGES_FOR_IO)) / 2 |
| - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); |
| /* Compute the desired number of image pages specified by image_size. */ |
| size = DIV_ROUND_UP(image_size, PAGE_SIZE); |
| if (size > max_size) |
| size = max_size; |
| /* |
| * If the desired number of image pages is at least as large as 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, avail_normal); |
| goto out; |
| } |
| |
| /* Estimate the minimum size of the image. */ |
| pages = minimum_image_size(saveable); |
| /* |
| * To avoid excessive pressure on the normal zone, leave room in it to |
| * accommodate an image of the minimum size (unless it's already too |
| * small, in which case don't preallocate pages from it at all). |
| */ |
| if (avail_normal > pages) |
| avail_normal -= pages; |
| else |
| avail_normal = 0; |
| 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; |
| if (alloc > pages_highmem) |
| alloc -= pages_highmem; |
| else |
| alloc = 0; |
| pages = preallocate_image_memory(alloc, avail_normal); |
| if (pages < alloc) { |
| /* We have exhausted non-highmem pages, try highmem. */ |
| alloc -= pages; |
| pages += pages_highmem; |
| pages_highmem = preallocate_image_highmem(alloc); |
| if (pages_highmem < alloc) |
| goto err_out; |
| pages += pages_highmem; |
| /* |
| * size is the desired number of saveable pages to leave in |
| * memory, so try to preallocate (all memory - size) pages. |
| */ |
| alloc = (count - pages) - size; |
| pages += preallocate_image_highmem(alloc); |
| } else { |
| /* |
| * There are approximately max_size saveable pages at this point |
| * and we want to reduce this number down to size. |
| */ |
| alloc = max_size - size; |
| size = preallocate_highmem_fraction(alloc, highmem, count); |
| pages_highmem += size; |
| alloc -= size; |
| size = preallocate_image_memory(alloc, avail_normal); |
| pages_highmem += preallocate_image_highmem(alloc - size); |
| pages += pages_highmem + size; |
| } |
| |
| /* |
| * 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. |
| */ |
| pages -= free_unnecessary_pages(); |
| |
| out: |
| stop = ktime_get(); |
| 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 - Count non-highmem pages needed for copying 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 - Check if there is enough free memory for the 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 - Allocate a buffer for highmem pages. |
| * |
| * If there are some highmem pages in the hibernation image, we may need a |
| * 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 less 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|__GFP_KSWAPD_RECLAIM); |
| 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 hibernation 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) |
| { |
| if (nr_highmem > 0) { |
| if (get_highmem_buffer(PG_ANY)) |
| 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 -ENOMEM; |
| } |
| |
| asmlinkage __visible 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 = get_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 - Prepare PFNs for saving. |
| * @bm: Memory bitmap. |
| * @buf: Memory buffer to store the PFNs in. |
| * |
| * PFNs corresponding to set bits in @bm are stored in the area of memory |
| * pointed to by @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; |
| /* Save page key for data page (s390 only). */ |
| page_key_read(buf + j); |
| } |
| } |
| |
| /** |
| * snapshot_read_next - Get the address to read the next image page from. |
| * @handle: Snapshot handle to be used for the reading. |
| * |
| * On the first call, @handle should point to a zeroed snapshot_handle |
| * structure. The structure gets populated then 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 the data stream condition, |
| * and negative numbers are returned on errors. If that happens, 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) { |
| clear_page(buffer); |
| 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); |
| copy_page(buffer, kaddr); |
| kunmap_atomic(kaddr); |
| handle->buffer = buffer; |
| } else { |
| handle->buffer = page_address(page); |
| } |
| } |
| handle->cur++; |
| return PAGE_SIZE; |
| } |
| |
| 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); |
| } |
| } |
| |
| /** |
| * mark_unsafe_pages - Mark pages that were used before hibernation. |
| * |
| * Mark the pages that cannot be used for storing the image during restoration, |
| * because they conflict with the pages that had been used before hibernation. |
| */ |
| static void mark_unsafe_pages(struct memory_bitmap *bm) |
| { |
| unsigned long pfn; |
| |
| /* Clear the "free"/"unsafe" bit for all PFNs */ |
| memory_bm_position_reset(free_pages_map); |
| pfn = memory_bm_next_pfn(free_pages_map); |
| while (pfn != BM_END_OF_MAP) { |
| memory_bm_clear_current(free_pages_map); |
| pfn = memory_bm_next_pfn(free_pages_map); |
| } |
| |
| /* Mark pages that correspond to the "original" PFNs as "unsafe" */ |
| duplicate_memory_bitmap(free_pages_map, bm); |
| |
| allocated_unsafe_pages = 0; |
| } |
| |
| static int check_header(struct swsusp_info *info) |
| { |
| char *reason; |
| |
| reason = check_image_kernel(info); |
| if (!reason && info->num_physpages != get_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 the 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 - Set bits corresponding to given PFNs in a memory bitmap. |
| * @bm: Memory bitmap. |
| * @buf: Area of memory containing the PFNs. |
| * |
| * For each element of the array pointed to by @buf (1 page at a time), set the |
| * corresponding bit in @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; |
| |
| /* Extract and buffer page key for data page (s390 only). */ |
| page_key_memorize(buf + j); |
| |
| if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j])) |
| memory_bm_set_bit(bm, buf[j]); |
| else |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| |
| #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 image. |
| * @bm: Memory bitmap. |
| * |
| * The bits in @bm that correspond to 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; |
| } |
| |
| static unsigned int safe_highmem_pages; |
| |
| static struct memory_bitmap *safe_highmem_bm; |
| |
| /** |
| * prepare_highmem_image - Allocate memory for loading highmem data from image. |
| * @bm: Pointer to an uninitialized memory bitmap structure. |
| * @nr_highmem_p: Pointer to the number of highmem image pages. |
| * |
| * 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 |
| * hibernation image is restored entirely) 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 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; |
| } |
| |
| static struct page *last_highmem_page; |
| |
| /** |
| * get_highmem_page_buffer - Prepare a buffer to store a highmem image page. |
| * |
| * For a given highmem image page get a buffer that suspend_write_next() should |
| * return to 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 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 most the most recent highmem image page. |
| * |
| * Copy the contents of a highmem image from @buffer, where the caller of |
| * snapshot_write_next() has stored 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); |
| copy_page(dst, buffer); |
| kunmap_atomic(dst); |
| 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 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 */ |
| |
| #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) |
| |
| /** |
| * prepare_image - Make room for loading hibernation image. |
| * @new_bm: Unitialized memory bitmap structure. |
| * @bm: Memory bitmap with unsafe pages marked. |
| * |
| * Use @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 image data, but without specifying what those |
| * pages will be used for just yet. Instead, we mark them all as allocated and |
| * create a lists of "safe" pages to be used later. On systems with high |
| * memory a list of "safe" highmem pages is created too. |
| */ |
| static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) |
| { |
| unsigned int nr_pages, nr_highmem; |
| struct linked_page *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); |
| mark_unsafe_pages(bm); |
| |
| 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. |
| * |
| * nr_copy_pages cannot be less than allocated_unsafe_pages too. |
| */ |
| 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 = safe_pages_list; |
| safe_pages_list = lp; |
| nr_pages--; |
| } |
| /* Preallocate memory for the image */ |
| 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--; |
| } |
| return 0; |
| |
| Free: |
| swsusp_free(); |
| return error; |
| } |
| |
| /** |
| * get_buffer - Get the address to store the next image data page. |
| * |
| * Get the address that snapshot_write_next() should return to 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 - Get the address to store the next image page. |
| * @handle: Snapshot handle structure to guide the writing. |
| * |
| * On the first call, @handle should point to a zeroed snapshot_handle |
| * structure. The structure gets populated then 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. Negative |
| * numbers are returned on errors, in which 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; |
| |
| safe_pages_list = NULL; |
| |
| error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); |
| if (error) |
| return error; |
| |
| /* Allocate buffer for page keys. */ |
| error = page_key_alloc(nr_copy_pages); |
| if (error) |
| return error; |
| |
| hibernate_restore_protection_begin(); |
| } 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(); |
| /* Restore page key for data page (s390 only). */ |
| page_key_write(handle->buffer); |
| hibernate_restore_protect_page(handle->buffer); |
| 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 - Complete the loading of a hibernation image. |
| * |
| * 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 highmem. Additionally, it recycles bitmap memory that's not |
| * necessary any more. |
| */ |
| void snapshot_write_finalize(struct snapshot_handle *handle) |
| { |
| copy_last_highmem_page(); |
| /* Restore page key for data page (s390 only). */ |
| page_key_write(handle->buffer); |
| page_key_free(); |
| hibernate_restore_protect_page(handle->buffer); |
| /* Do that only if we have loaded the image entirely */ |
| if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) { |
| memory_bm_recycle(&orig_bm); |
| 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); |
| kaddr2 = kmap_atomic(p2); |
| copy_page(buf, kaddr1); |
| copy_page(kaddr1, kaddr2); |
| copy_page(kaddr2, buf); |
| kunmap_atomic(kaddr2); |
| kunmap_atomic(kaddr1); |
| } |
| |
| /** |
| * restore_highmem - Put highmem image pages into their original locations. |
| * |
| * For each highmem page that was in use before hibernation and is included in |
| * the image, and also has been allocated by the "restore" kernel, swap its |
| * current contents with the previous (ie. "before hibernation") ones. |
| * |
| * If the restore eventually fails, we can call this function once again and |
| * restore the highmem state as seen by the restore kernel. |
| */ |
| 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 */ |