| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Rafael J. Wysocki | 7045 | 70.02% | 60 | 35.29% |
| Joerg Roedel | 1471 | 14.62% | 7 | 4.12% |
| Brian Geffon | 449 | 4.46% | 3 | 1.76% |
| Kefeng Wang | 190 | 1.89% | 1 | 0.59% |
| Mike Rapoport | 135 | 1.34% | 5 | 2.94% |
| Anisse Astier | 78 | 0.78% | 1 | 0.59% |
| Kamezawa Hiroyuki | 77 | 0.77% | 2 | 1.18% |
| Andrew Morton | 56 | 0.56% | 5 | 2.94% |
| James Morse | 46 | 0.46% | 1 | 0.59% |
| Pavel Machek | 44 | 0.44% | 10 | 5.88% |
| Patrick Mochel | 34 | 0.34% | 7 | 4.12% |
| David Hildenbrand | 29 | 0.29% | 2 | 1.18% |
| Luigi Semenzato | 29 | 0.29% | 1 | 0.59% |
| Vlastimil Babka | 28 | 0.28% | 1 | 0.59% |
| Björn Helgaas | 28 | 0.28% | 2 | 1.18% |
| Luo Xueqin | 26 | 0.26% | 1 | 0.59% |
| Stanislaw Gruszka | 24 | 0.24% | 2 | 1.18% |
| Joe Perches | 24 | 0.24% | 1 | 0.59% |
| Christoph Lameter | 24 | 0.24% | 2 | 1.18% |
| Jiri Slaby | 20 | 0.20% | 1 | 0.59% |
| Fengguang Wu | 16 | 0.16% | 3 | 1.76% |
| Wonhong Kwon | 15 | 0.15% | 1 | 0.59% |
| Aaron Lu | 14 | 0.14% | 1 | 0.59% |
| Xishi Qiu | 13 | 0.13% | 1 | 0.59% |
| Balbir Singh | 11 | 0.11% | 1 | 0.59% |
| Tina Ruchandani | 10 | 0.10% | 1 | 0.59% |
| Alexander Potapenko | 8 | 0.08% | 1 | 0.59% |
| Andi Kleen | 8 | 0.08% | 2 | 1.18% |
| Andy Whitcroft | 8 | 0.08% | 1 | 0.59% |
| Luca Tettamanti | 7 | 0.07% | 1 | 0.59% |
| Jan Beulich | 7 | 0.07% | 1 | 0.59% |
| Mel Gorman | 7 | 0.07% | 3 | 1.76% |
| Michael Ellerman | 5 | 0.05% | 1 | 0.59% |
| Linus Torvalds (pre-git) | 5 | 0.05% | 3 | 1.76% |
| Peter Zijlstra | 4 | 0.04% | 1 | 0.59% |
| Johannes Berg | 4 | 0.04% | 1 | 0.59% |
| Gideon Israel Dsouza | 4 | 0.04% | 1 | 0.59% |
| Akinobu Mita | 4 | 0.04% | 1 | 0.59% |
| Li Yang | 4 | 0.04% | 1 | 0.59% |
| Gerald Schaefer | 4 | 0.04% | 1 | 0.59% |
| Jiang Liu | 4 | 0.04% | 1 | 0.59% |
| Wen Yang | 4 | 0.04% | 1 | 0.59% |
| Laura Abbott | 3 | 0.03% | 2 | 1.18% |
| Ingo Molnar | 3 | 0.03% | 1 | 0.59% |
| Motohiro Kosaki | 3 | 0.03% | 1 | 0.59% |
| Shaohua Li | 3 | 0.03% | 2 | 1.18% |
| Zhen Lei | 2 | 0.02% | 1 | 0.59% |
| Thomas Gleixner | 2 | 0.02% | 1 | 0.59% |
| JoonSoo Kim | 2 | 0.02% | 1 | 0.59% |
| Alexey Dobriyan | 2 | 0.02% | 1 | 0.59% |
| Martin Schwidefsky | 2 | 0.02% | 1 | 0.59% |
| Roman Gushchin | 2 | 0.02% | 1 | 0.59% |
| Pavankumar Kondeti | 2 | 0.02% | 1 | 0.59% |
| Colin Ian King | 1 | 0.01% | 1 | 0.59% |
| Amadeusz Sławiński | 1 | 0.01% | 1 | 0.59% |
| Rainer Fiebig | 1 | 0.01% | 1 | 0.59% |
| Wang Honghui | 1 | 0.01% | 1 | 0.59% |
| Al Viro | 1 | 0.01% | 1 | 0.59% |
| Naoya Horiguchi | 1 | 0.01% | 1 | 0.59% |
| Santosh Shilimkar | 1 | 0.01% | 1 | 0.59% |
| Arun K S | 1 | 0.01% | 1 | 0.59% |
| Haowen Bai | 1 | 0.01% | 1 | 0.59% |
| Pushkar Jambhlekar | 1 | 0.01% | 1 | 0.59% |
| Randy Dunlap | 1 | 0.01% | 1 | 0.59% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.59% |
| xiongxin | 1 | 0.01% | 1 | 0.59% |
| Total | 10062 | 170 |
// SPDX-License-Identifier: GPL-2.0-only /* * 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> */ #define pr_fmt(fmt) "PM: hibernation: " fmt #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/memblock.h> #include <linux/nmi.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 <linux/set_memory.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> #include <asm/io.h> #include "power.h" #if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY) 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_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ /* * The calls to set_direct_map_*() should not fail because remapping a page * here means that we only update protection bits in an existing PTE. * It is still worth to have a warning here if something changes and this * will no longer be the case. */ static inline void hibernate_map_page(struct page *page) { if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { int ret = set_direct_map_default_noflush(page); if (ret) pr_warn_once("Failed to remap page\n"); } else { debug_pagealloc_map_pages(page, 1); } } static inline void hibernate_unmap_page(struct page *page) { if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { unsigned long addr = (unsigned long)page_address(page); int ret = set_direct_map_invalid_noflush(page); if (ret) pr_warn_once("Failed to remap page\n"); flush_tlb_kernel_range(addr, addr + PAGE_SIZE); } else { debug_pagealloc_unmap_pages(page, 1); } } 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 consisting of many linked lists of * objects. The main list's elements are of type struct zone_bitmap * and each of them corresponds 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 */ }; /* struct 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; unsigned long cur_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. * @gfp_mask: GFP mask for the allocation. * @safe_needed: Get pages not used before hibernation (restore only) * @ca: Pointer to a linked list of pages ("a chain") to allocate from * @list: Radix Tree node to add. * * 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.cur_pfn = BM_END_OF_MAP; 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. */ /* * If the zone we wish to scan is the current zone and the * pfn falls into the current node then we do not need to walk * the tree. */ node = bm->cur.node; if (zone == bm->cur.zone && ((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; bm->cur.cur_pfn = pfn; /* 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 unsigned long memory_bm_get_current(struct memory_bitmap *bm) { return bm->cur.cur_pfn; } 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_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; bm->cur.cur_pfn = pfn; return pfn; } } while (rtree_next_node(bm)); bm->cur.cur_pfn = BM_END_OF_MAP; 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) { 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; } } /* This allocation cannot fail */ region = memblock_alloc(sizeof(struct nosave_region), SMP_CACHE_BYTES); if (!region) panic("%s: Failed to allocate %zu bytes\n", __func__, sizeof(struct nosave_region)); region->start_pfn = start_pfn; region->end_pfn = end_pfn; list_add_tail(®ion->list, &nosave_regions); Report: pr_info("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("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("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("Basic memory bitmaps freed\n"); } static void clear_or_poison_free_page(struct page *page) { if (page_poisoning_enabled_static()) __kernel_poison_pages(page, 1); else if (want_init_on_free()) clear_highpage(page); } void clear_or_poison_free_pages(void) { struct memory_bitmap *bm = free_pages_map; unsigned long pfn; if (WARN_ON(!(free_pages_map))) return; if (page_poisoning_enabled() || want_init_on_free()) { memory_bm_position_reset(bm); pfn = memory_bm_next_pfn(bm); while (pfn != BM_END_OF_MAP) { if (pfn_valid(pfn)) clear_or_poison_free_page(pfn_to_page(pfn)); pfn = memory_bm_next_pfn(bm); } memory_bm_position_reset(bm); pr_info("free pages cleared after restore\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; } /* * Touch the watchdog for every WD_PAGE_COUNT pages. */ #define WD_PAGE_COUNT (128*1024) static void mark_free_pages(struct zone *zone) { unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT; unsigned long flags; unsigned int order, t; struct page *page; if (zone_is_empty(zone)) return; spin_lock_irqsave(&zone->lock, flags); max_zone_pfn = zone_end_pfn(zone); for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (pfn_valid(pfn)) { page = pfn_to_page(pfn); if (!--page_count) { touch_nmi_watchdog(); page_count = WD_PAGE_COUNT; } if (page_zone(page) != zone) continue; if (!swsusp_page_is_forbidden(page)) swsusp_unset_page_free(page); } for_each_migratetype_order(order, t) { list_for_each_entry(page, &zone->free_area[order].free_list[t], buddy_list) { unsigned long i; pfn = page_to_pfn(page); for (i = 0; i < (1UL << order); i++) { if (!--page_count) { touch_nmi_watchdog(); page_count = WD_PAGE_COUNT; } swsusp_set_page_free(pfn_to_page(pfn + i)); } } } spin_unlock_irqrestore(&zone->lock, flags); } #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_online_page(pfn); if (!page || 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) || PageOffline(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_online_page(pfn); if (!page || page_zone(page) != zone) return NULL; BUG_ON(PageHighMem(page)); if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) return NULL; if (PageOffline(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. Returns true if the page was filled with only zeros, * otherwise false. */ static inline bool do_copy_page(long *dst, long *src) { long z = 0; int n; for (n = PAGE_SIZE / sizeof(long); n; n--) { z |= *src; *dst++ = *src++; } return !z; } /** * 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 or * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present() * always returns 'true'. Returns true if the page was entirely composed of * zeros, otherwise it will return false. */ static bool safe_copy_page(void *dst, struct page *s_page) { bool zeros_only; if (kernel_page_present(s_page)) { zeros_only = do_copy_page(dst, page_address(s_page)); } else { hibernate_map_page(s_page); zeros_only = do_copy_page(dst, page_address(s_page)); hibernate_unmap_page(s_page); } return zeros_only; } #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 bool copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { struct page *s_page, *d_page; void *src, *dst; bool zeros_only; 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); zeros_only = 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() */ zeros_only = safe_copy_page(buffer, s_page); dst = kmap_atomic(d_page); copy_page(dst, buffer); kunmap_atomic(dst); } else { zeros_only = safe_copy_page(page_address(d_page), s_page); } } return zeros_only; } #else #define page_is_saveable(zone, pfn) saveable_page(zone, pfn) static inline int copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { return safe_copy_page(page_address(pfn_to_page(dst_pfn)), pfn_to_page(src_pfn)); } #endif /* CONFIG_HIGHMEM */ /* * Copy data pages will copy all pages into pages pulled from the copy_bm. * If a page was entirely filled with zeros it will be marked in the zero_bm. * * Returns the number of pages copied. */ static unsigned long copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm, struct memory_bitmap *zero_bm) { unsigned long copied_pages = 0; struct zone *zone; unsigned long pfn, copy_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); copy_pfn = memory_bm_next_pfn(copy_bm); for(;;) { pfn = memory_bm_next_pfn(orig_bm); if (unlikely(pfn == BM_END_OF_MAP)) break; if (copy_data_page(copy_pfn, pfn)) { memory_bm_set_bit(zero_bm, pfn); /* Use this copy_pfn for a page that is not full of zeros */ continue; } copied_pages++; copy_pfn = memory_bm_next_pfn(copy_bm); } return copied_pages; } /* 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; /* Number of zero pages */ static unsigned int nr_zero_pages; /* * Numbers of normal and highmem page frames allocated for hibernation image * before suspending devices. */ static 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; /* Memory bitmap which tracks which saveable pages were zero filled. */ static struct memory_bitmap zero_bm; /** * swsusp_free - Free pages allocated for hibernation image. * * Image pages are allocated 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; nr_zero_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) { return div64_u64(x * multiplier, base); } 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. */ static unsigned long minimum_image_size(unsigned long saveable) { unsigned long size; size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) + 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); 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 reserved_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; pr_info("Preallocating image memory\n"); start = ktime_get(); error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); if (error) { pr_err("Cannot allocate original bitmap\n"); goto err_out; } error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY); if (error) { pr_err("Cannot allocate copy bitmap\n"); goto err_out; } error = memory_bm_create(&zero_bm, GFP_IMAGE, PG_ANY); if (error) { pr_err("Cannot allocate zero bitmap\n"); goto err_out; } alloc_normal = 0; alloc_highmem = 0; nr_zero_pages = 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; /* 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) { pr_err("Image allocation is %lu pages short\n", alloc - pages_highmem); 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(); pr_info("Allocated %lu pages for snapshot\n", pages); swsusp_show_speed(start, stop, pages, "Allocated"); return 0; err_out: 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("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, safe_needed); return buffer ? 0 : -ENOMEM; } /** * alloc_highmem_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 *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); 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; pr_info("Creating image:\n"); drain_local_pages(NULL); nr_pages = count_data_pages(); nr_highmem = count_highmem_pages(); pr_info("Need to copy %u pages\n", nr_pages + nr_highmem); if (!enough_free_mem(nr_pages, nr_highmem)) { pr_err("Not enough free memory\n"); return -ENOMEM; } if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) { pr_err("Memory allocation failed\n"); return -ENOMEM; } /* * During allocating of suspend pagedir, new cold pages may appear. * Kill them. */ drain_local_pages(NULL); nr_copy_pages = copy_data_pages(©_bm, &orig_bm, &zero_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; /* We don't actually copy the zero pages */ nr_zero_pages = nr_pages - nr_copy_pages; nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); pr_info("Image created (%d pages copied, %d zero pages)\n", nr_copy_pages, nr_zero_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 const 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); } #define ENCODED_PFN_ZERO_FLAG ((unsigned long)1 << (BITS_PER_LONG - 1)) #define ENCODED_PFN_MASK (~ENCODED_PFN_ZERO_FLAG) /** * pack_pfns - Prepare PFNs for saving. * @bm: Memory bitmap. * @buf: Memory buffer to store the PFNs in. * @zero_bm: Memory bitmap containing PFNs of zero pages. * * PFNs corresponding to set bits in @bm are stored in the area of memory * pointed to by @buf (1 page at a time). Pages which were filled with only * zeros will have the highest bit set in the packed format to distinguish * them from PFNs which will be contained in the image file. */ static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm, struct memory_bitmap *zero_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; if (memory_bm_test_bit(zero_bm, buf[j])) buf[j] |= ENCODED_PFN_ZERO_FLAG; } } /** * 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, &zero_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) { const char *reason; reason = check_image_kernel(info); if (!reason && info->num_physpages != get_num_physpages()) reason = "memory size"; if (reason) { pr_err("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. * @zero_bm: Memory bitmap with the zero PFNs marked. * * For each element of the array pointed to by @buf (1 page at a time), set the * corresponding bit in @bm. If the page was originally populated with only * zeros then a corresponding bit will also be set in @zero_bm. */ static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm, struct memory_bitmap *zero_bm) { unsigned long decoded_pfn; bool zero; int j; for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { if (unlikely(buf[j] == BM_END_OF_MAP)) break; zero = !!(buf[j] & ENCODED_PFN_ZERO_FLAG); decoded_pfn = buf[j] & ENCODED_PFN_MASK; if (pfn_valid(decoded_pfn) && memory_bm_pfn_present(bm, decoded_pfn)) { memory_bm_set_bit(bm, decoded_pfn); if (zero) { memory_bm_set_bit(zero_bm, decoded_pfn); nr_zero_pages++; } } else { if (!pfn_valid(decoded_pfn)) pr_err(FW_BUG "Memory map mismatch at 0x%llx after hibernation\n", (unsigned long long)PFN_PHYS(decoded_pfn)); 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 uninitialized). * * 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 = __get_safe_page(ca->gfp_mask); if (!kaddr) return ERR_PTR(-ENOMEM); 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: Uninitialized memory bitmap structure. * @bm: Memory bitmap with unsafe pages marked. * @zero_bm: Memory bitmap containing the zero pages. * * 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. * * Because it was not known which pages were unsafe when @zero_bm was created, * make a copy of it and recreate it within safe pages. */ static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm, struct memory_bitmap *zero_bm) { unsigned int nr_pages, nr_highmem; struct memory_bitmap tmp; 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); /* Make a copy of zero_bm so it can be created in safe pages */ error = memory_bm_create(&tmp, GFP_ATOMIC, PG_SAFE); if (error) goto Free; duplicate_memory_bitmap(&tmp, zero_bm); memory_bm_free(zero_bm, PG_UNSAFE_KEEP); /* Recreate zero_bm in safe pages */ error = memory_bm_create(zero_bm, GFP_ATOMIC, PG_SAFE); if (error) goto Free; duplicate_memory_bitmap(zero_bm, &tmp); memory_bm_free(&tmp, PG_UNSAFE_CLEAR); /* At this point zero_bm is in safe pages and it can be used for restoring. */ 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_zero_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_zero_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 = __get_safe_page(ca->gfp_mask); if (!pbe->address) return ERR_PTR(-ENOMEM); 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; next: /* Check if we have already loaded the entire image */ if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) return 0; 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; error = memory_bm_create(&zero_bm, GFP_ATOMIC, PG_ANY); if (error) return error; nr_zero_pages = 0; hibernate_restore_protection_begin(); } else if (handle->cur <= nr_meta_pages + 1) { error = unpack_orig_pfns(buffer, ©_bm, &zero_bm); if (error) return error; if (handle->cur == nr_meta_pages + 1) { error = prepare_image(&orig_bm, ©_bm, &zero_bm); if (error) return error; chain_init(&ca, GFP_ATOMIC, PG_SAFE); memory_bm_position_reset(&orig_bm); memory_bm_position_reset(&zero_bm); restore_pblist = NULL; handle->buffer = get_buffer(&orig_bm, &ca); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); } } else { copy_last_highmem_page(); hibernate_restore_protect_page(handle->buffer); handle->buffer = get_buffer(&orig_bm, &ca); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); } handle->sync_read = (handle->buffer == buffer); handle->cur++; /* Zero pages were not included in the image, memset it and move on. */ if (handle->cur > nr_meta_pages + 1 && memory_bm_test_bit(&zero_bm, memory_bm_get_current(&orig_bm))) { memset(handle->buffer, 0, PAGE_SIZE); goto next; } 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(); 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 + nr_zero_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 + nr_zero_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 */
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