--- /dev/null
+/*
+ * 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"
+
+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;
+
+/* Pointer to an auxiliary buffer (1 page) */
+static void *buffer;
+
+/**
+ * @safe_needed - on resume, for storing the PBE list and the image,
+ * we can only use memory pages that do not conflict with the pages
+ * used before suspend. The unsafe pages have PageNosaveFree set
+ * and we count them using unsafe_pages.
+ *
+ * Each allocated image page is marked as PageNosave and PageNosaveFree
+ * so that swsusp_free() can release it.
+ */
+
+#define PG_ANY 0
+#define PG_SAFE 1
+#define PG_UNSAFE_CLEAR 1
+#define PG_UNSAFE_KEEP 0
+
+static unsigned int allocated_unsafe_pages;
+
+static void *get_image_page(gfp_t gfp_mask, int safe_needed)
+{
+ void *res;
+
+ res = (void *)get_zeroed_page(gfp_mask);
+ if (safe_needed)
+ while (res && swsusp_page_is_free(virt_to_page(res))) {
+ /* The page is unsafe, mark it for swsusp_free() */
+ swsusp_set_page_forbidden(virt_to_page(res));
+ allocated_unsafe_pages++;
+ res = (void *)get_zeroed_page(gfp_mask);
+ }
+ if (res) {
+ swsusp_set_page_forbidden(virt_to_page(res));
+ swsusp_set_page_free(virt_to_page(res));
+ }
+ return res;
+}
+
+unsigned long get_safe_page(gfp_t gfp_mask)
+{
+ return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
+}
+
+static struct page *alloc_image_page(gfp_t gfp_mask)
+{
+ struct page *page;
+
+ page = alloc_page(gfp_mask);
+ if (page) {
+ swsusp_set_page_forbidden(page);
+ swsusp_set_page_free(page);
+ }
+ return page;
+}
+
+/**
+ * free_image_page - free page represented by @addr, allocated with
+ * get_image_page (page flags set by it must be cleared)
+ */
+
+static inline void free_image_page(void *addr, int clear_nosave_free)
+{
+ struct page *page;
+
+ BUG_ON(!virt_addr_valid(addr));
+
+ page = virt_to_page(addr);
+
+ swsusp_unset_page_forbidden(page);
+ if (clear_nosave_free)
+ swsusp_unset_page_free(page);
+
+ __free_page(page);
+}
+
+/* struct linked_page is used to build chains of pages */
+
+#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
+
+struct linked_page {
+ struct linked_page *next;
+ char data[LINKED_PAGE_DATA_SIZE];
+} __packed;
+
+static inline void
+free_list_of_pages(struct linked_page *list, int clear_page_nosave)
+{
+ while (list) {
+ struct linked_page *lp = list->next;
+
+ free_image_page(list, clear_page_nosave);
+ list = lp;
+ }
+}
+
+/**
+ * struct chain_allocator is used for allocating small objects out of
+ * a linked list of pages called 'the chain'.
+ *
+ * The chain grows each time when there is no room for a new object in
+ * the current page. The allocated objects cannot be freed individually.
+ * It is only possible to free them all at once, by freeing the entire
+ * chain.
+ *
+ * NOTE: The chain allocator may be inefficient if the allocated objects
+ * are not much smaller than PAGE_SIZE.
+ */
+
+struct chain_allocator {
+ struct linked_page *chain; /* the chain */
+ unsigned int used_space; /* total size of objects allocated out
+ * of the current page
+ */
+ gfp_t gfp_mask; /* mask for allocating pages */
+ int safe_needed; /* if set, only "safe" pages are allocated */
+};
+
+static void
+chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
+{
+ ca->chain = NULL;
+ ca->used_space = LINKED_PAGE_DATA_SIZE;
+ ca->gfp_mask = gfp_mask;
+ ca->safe_needed = safe_needed;
+}
+
+static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
+{
+ void *ret;
+
+ if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
+ struct linked_page *lp;
+
+ lp = get_image_page(ca->gfp_mask, ca->safe_needed);
+ if (!lp)
+ return NULL;
+
+ lp->next = ca->chain;
+ ca->chain = lp;
+ ca->used_space = 0;
+ }
+ ret = ca->chain->data + ca->used_space;
+ ca->used_space += size;
+ return ret;
+}
+
+/**
+ * Data types related to memory bitmaps.
+ *
+ * Memory bitmap is a structure consiting of many linked lists of
+ * objects. The main list's elements are of type struct zone_bitmap
+ * and each of them corresonds to one zone. For each zone bitmap
+ * object there is a list of objects of type struct bm_block that
+ * represent each blocks of bitmap in which information is stored.
+ *
+ * struct memory_bitmap contains a pointer to the main list of zone
+ * bitmap objects, a struct bm_position used for browsing the bitmap,
+ * and a pointer to the list of pages used for allocating all of the
+ * zone bitmap objects and bitmap block objects.
+ *
+ * NOTE: It has to be possible to lay out the bitmap in memory
+ * using only allocations of order 0. Additionally, the bitmap is
+ * designed to work with arbitrary number of zones (this is over the
+ * top for now, but let's avoid making unnecessary assumptions ;-).
+ *
+ * struct zone_bitmap contains a pointer to a list of bitmap block
+ * objects and a pointer to the bitmap block object that has been
+ * most recently used for setting bits. Additionally, it contains the
+ * pfns that correspond to the start and end of the represented zone.
+ *
+ * struct bm_block contains a pointer to the memory page in which
+ * information is stored (in the form of a block of bitmap)
+ * It also contains the pfns that correspond to the start and end of
+ * the represented memory area.
+ *
+ * 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 empty
+ */
+static void free_mem_extents(struct list_head *list)
+{
+ struct mem_extent *ext, *aux;
+
+ list_for_each_entry_safe(ext, aux, list, hook) {
+ list_del(&ext->hook);
+ kfree(ext);
+ }
+}
+
+/**
+ * create_mem_extents - create a list of memory extents representing
+ * contiguous ranges of PFNs
+ * @list - list to put the extents into
+ * @gfp_mask - mask to use for memory allocations
+ */
+static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
+{
+ struct zone *zone;
+
+ INIT_LIST_HEAD(list);
+
+ for_each_populated_zone(zone) {
+ unsigned long zone_start, zone_end;
+ struct mem_extent *ext, *cur, *aux;
+
+ zone_start = zone->zone_start_pfn;
+ zone_end = zone_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
+ */
+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 pfn in the memory
+ * bitmap
+ *
+ * Find the bit in the bitmap @bm that corresponds to given pfn.
+ * The cur.zone, cur.block and cur.node_pfn member of @bm are
+ * updated.
+ * It walks the radix tree to find the page which contains the bit for
+ * pfn and returns the bit position 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 a zone. Now walk the radix tree to find the leave
+ * 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 - Jumps to the next leave node
+ *
+ * Sets 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.
+ *
+ * Returns true if there is a next node, false otherwise.
+ */
+static bool rtree_next_node(struct memory_bitmap *bm)
+{
+ bm->cur.node = list_entry(bm->cur.node->list.next,
+ struct rtree_node, list);
+ if (&bm->cur.node->list != &bm->cur.zone->leaves) {
+ bm->cur.node_pfn += BM_BITS_PER_BLOCK;
+ bm->cur.node_bit = 0;
+ touch_softlockup_watchdog();
+ return true;
+ }
+
+ /* No more nodes, goto next zone */
+ bm->cur.zone = list_entry(bm->cur.zone->list.next,
+ struct mem_zone_bm_rtree, list);
+ if (&bm->cur.zone->list != &bm->zones) {
+ 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 the bitmap @bm
+ *
+ * Starting from the last returned position this function searches
+ * for the next set bit in the memory bitmap and returns its
+ * number. If no more bit is set BM_END_OF_MAP is returned.
+ *
+ * It is required to run memory_bm_position_reset() before the
+ * first call to this function.
+ */
+static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
+{
+ 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 the suspend.
+ */
+
+struct nosave_region {
+ struct list_head list;
+ unsigned long start_pfn;
+ unsigned long end_pfn;
+};
+
+static LIST_HEAD(nosave_regions);
+
+/**
+ * register_nosave_region - register a range of page frames the contents
+ * of which should not be saved during the suspend (to be used in the early
+ * initialization code)
+ */
+
+void __init
+__register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
+ int use_kmalloc)
+{
+ struct nosave_region *region;
+
+ if (start_pfn >= end_pfn)
+ return;
+
+ if (!list_empty(&nosave_regions)) {
+ /* Try to extend the previous region (they should be sorted) */
+ region = list_entry(nosave_regions.prev,
+ struct nosave_region, list);
+ if (region->end_pfn == start_pfn) {
+ region->end_pfn = end_pfn;
+ goto Report;
+ }
+ }
+ if (use_kmalloc) {
+ /* during init, this shouldn't fail */
+ region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
+ BUG_ON(!region);
+ } else
+ /* This allocation cannot fail */
+ region = 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 - set bits corresponding to the page frames the
+ * contents of which should not be saved in a given bitmap.
+ */
+
+static void mark_nosave_pages(struct memory_bitmap *bm)
+{
+ struct nosave_region *region;
+
+ if (list_empty(&nosave_regions))
+ return;
+
+ list_for_each_entry(region, &nosave_regions, list) {
+ unsigned long pfn;
+
+ pr_debug("PM: Marking nosave pages: [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 needed for marking page
+ * frames that should not be saved and free page frames. The pointers
+ * forbidden_pages_map and free_pages_map are only modified if everything
+ * goes well, because we don't want the bits to be used before both bitmaps
+ * are set up.
+ */
+
+int create_basic_memory_bitmaps(void)
+{
+ struct memory_bitmap *bm1, *bm2;
+ int error = 0;
+
+ 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 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 additional pages
+ * be needed for setting up the suspend image data structures for given
+ * zone (usually the returned value is greater than the exact number)
+ */
+
+unsigned int snapshot_additional_pages(struct zone *zone)
+{
+ unsigned int 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, system-wide.
+ */
+
+static unsigned int count_free_highmem_pages(void)
+{
+ struct zone *zone;
+ unsigned int cnt = 0;
+
+ for_each_populated_zone(zone)
+ if (is_highmem(zone))
+ cnt += zone_page_state(zone, NR_FREE_PAGES);
+
+ return cnt;
+}
+
+/**
+ * saveable_highmem_page - Determine whether a highmem page should be
+ * included in the suspend image.
+ *
+ * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
+ * and it isn't a part of a free chunk of pages.
+ */
+static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
+{
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ return NULL;
+
+ page = pfn_to_page(pfn);
+ if (page_zone(page) != zone)
+ return NULL;
+
+ BUG_ON(!PageHighMem(page));
+
+ if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
+ PageReserved(page))
+ return NULL;
+
+ 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 - Determine whether a non-highmem page should be included
+ * in the suspend image.
+ *
+ * We should save the page if it isn't Nosave, and is not in the range
+ * of pages statically defined as 'unsaveable', and it isn't a part of
+ * a free chunk of pages.
+ */
+static struct page *saveable_page(struct zone *zone, unsigned long pfn)
+{
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ return NULL;
+
+ page = pfn_to_page(pfn);
+ if (page_zone(page) != zone)
+ return NULL;
+
+ BUG_ON(PageHighMem(page));
+
+ if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
+ return NULL;
+
+ if (PageReserved(page)
+ && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
+ return NULL;
+
+ 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 - 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)) {
+ /* 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 the suspend.
+ *
+ * Suspend pages are alocated before the atomic copy is made, so we
+ * need to release them after the resume.
+ */
+
+void swsusp_free(void)
+{
+ 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);
+ __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;
+}
+
+/* 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_page_state(NR_ACTIVE_ANON)
+ + global_page_state(NR_INACTIVE_ANON)
+ + global_page_state(NR_ACTIVE_FILE)
+ + global_page_state(NR_INACTIVE_FILE)
+ - global_page_state(NR_FILE_MAPPED);
+
+ return saveable <= size ? 0 : saveable - size;
+}
+
+/**
+ * hibernate_preallocate_memory - Preallocate memory for hibernation image
+ *
+ * To create a hibernation image it is necessary to make a copy of every page
+ * frame in use. We also need a number of page frames to be free during
+ * hibernation for allocations made while saving the image and for device
+ * drivers, in case they need to allocate memory from their hibernation
+ * callbacks (these two numbers are given by PAGES_FOR_IO (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 - compute the number of non-highmem pages
+ * that will be necessary for creating copies of highmem pages.
+ */
+
+static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
+{
+ unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
+
+ if (free_highmem >= nr_highmem)
+ nr_highmem = 0;
+ else
+ nr_highmem -= free_highmem;
+
+ return nr_highmem;
+}
+#else
+static unsigned int
+count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * enough_free_mem - Make sure we have enough free memory for the
+ * snapshot image.
+ */
+
+static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
+{
+ struct zone *zone;
+ unsigned int free = alloc_normal;
+
+ for_each_populated_zone(zone)
+ if (!is_highmem(zone))
+ free += zone_page_state(zone, NR_FREE_PAGES);
+
+ nr_pages += count_pages_for_highmem(nr_highmem);
+ pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n",
+ nr_pages, PAGES_FOR_IO, free);
+
+ return free > nr_pages + PAGES_FOR_IO;
+}
+
+#ifdef CONFIG_HIGHMEM
+/**
+ * get_highmem_buffer - if there are some highmem pages in the suspend
+ * image, we may need the buffer to copy them and/or load their data.
+ */
+
+static inline int get_highmem_buffer(int safe_needed)
+{
+ buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
+ return buffer ? 0 : -ENOMEM;
+}
+
+/**
+ * alloc_highmem_image_pages - allocate some highmem pages for the image.
+ * Try to allocate as many pages as needed, but if the number of free
+ * highmem pages is lesser than that, allocate them all.
+ */
+
+static inline unsigned int
+alloc_highmem_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
+{
+ unsigned int to_alloc = count_free_highmem_pages();
+
+ if (to_alloc > nr_highmem)
+ to_alloc = nr_highmem;
+
+ nr_highmem -= to_alloc;
+ while (to_alloc-- > 0) {
+ struct page *page;
+
+ page = alloc_image_page(__GFP_HIGHMEM);
+ memory_bm_set_bit(bm, page_to_pfn(page));
+ }
+ return nr_highmem;
+}
+#else
+static inline int get_highmem_buffer(int safe_needed) { return 0; }
+
+static inline unsigned int
+alloc_highmem_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * swsusp_alloc - allocate memory for the suspend image
+ *
+ * We first try to allocate as many highmem pages as there are
+ * saveable highmem pages in the system. If that fails, we allocate
+ * non-highmem pages for the copies of the remaining highmem ones.
+ *
+ * In this approach it is likely that the copies of highmem pages will
+ * also be located in the high memory, because of the way in which
+ * copy_data_pages() works.
+ */
+
+static int
+swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
+ unsigned int nr_pages, unsigned int nr_highmem)
+{
+ 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 - pfns corresponding to the set bits found in the bitmap @bm
+ * are stored in the array @buf[] (1 page at a time)
+ */
+
+static inline void
+pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+ buf[j] = memory_bm_next_pfn(bm);
+ if (unlikely(buf[j] == BM_END_OF_MAP))
+ break;
+ /* Save page key for data page (s390 only). */
+ page_key_read(buf + j);
+ }
+}
+
+/**
+ * snapshot_read_next - used for reading the system memory snapshot.
+ *
+ * On the first call to it @handle should point to a zeroed
+ * snapshot_handle structure. The structure gets updated and a pointer
+ * to it should be passed to this function every next time.
+ *
+ * On success the function returns a positive number. Then, the caller
+ * is allowed to read up to the returned number of bytes from the memory
+ * location computed by the data_of() macro.
+ *
+ * The function returns 0 to indicate the end of data stream condition,
+ * and a negative number is returned on error. In such cases the
+ * structure pointed to by @handle is not updated and should not be used
+ * any more.
+ */
+
+int snapshot_read_next(struct snapshot_handle *handle)
+{
+ if (handle->cur > nr_meta_pages + nr_copy_pages)
+ return 0;
+
+ if (!buffer) {
+ /* This makes the buffer be freed by swsusp_free() */
+ buffer = get_image_page(GFP_ATOMIC, PG_ANY);
+ if (!buffer)
+ return -ENOMEM;
+ }
+ if (!handle->cur) {
+ int error;
+
+ error = init_header((struct swsusp_info *)buffer);
+ if (error)
+ return error;
+ handle->buffer = buffer;
+ memory_bm_position_reset(&orig_bm);
+ memory_bm_position_reset(©_bm);
+ } else if (handle->cur <= nr_meta_pages) {
+ 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;
+}
+
+/**
+ * mark_unsafe_pages - mark the pages that cannot be used for storing
+ * the image during resume, because they conflict with the pages that
+ * had been used before suspend
+ */
+
+static int mark_unsafe_pages(struct memory_bitmap *bm)
+{
+ struct zone *zone;
+ unsigned long pfn, max_zone_pfn;
+
+ /* Clear page flags */
+ for_each_populated_zone(zone) {
+ max_zone_pfn = zone_end_pfn(zone);
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+ if (pfn_valid(pfn))
+ swsusp_unset_page_free(pfn_to_page(pfn));
+ }
+
+ /* Mark pages that correspond to the "original" pfns as "unsafe" */
+ memory_bm_position_reset(bm);
+ do {
+ pfn = memory_bm_next_pfn(bm);
+ if (likely(pfn != BM_END_OF_MAP)) {
+ if (likely(pfn_valid(pfn)))
+ swsusp_set_page_free(pfn_to_page(pfn));
+ else
+ return -EFAULT;
+ }
+ } while (pfn != BM_END_OF_MAP);
+
+ allocated_unsafe_pages = 0;
+
+ return 0;
+}
+
+static void
+duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
+{
+ unsigned long pfn;
+
+ memory_bm_position_reset(src);
+ pfn = memory_bm_next_pfn(src);
+ while (pfn != BM_END_OF_MAP) {
+ memory_bm_set_bit(dst, pfn);
+ pfn = memory_bm_next_pfn(src);
+ }
+}
+
+static int check_header(struct swsusp_info *info)
+{
+ char *reason;
+
+ reason = check_image_kernel(info);
+ if (!reason && info->num_physpages != 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 data from it
+ */
+
+static int
+load_header(struct swsusp_info *info)
+{
+ int error;
+
+ restore_pblist = NULL;
+ error = check_header(info);
+ if (!error) {
+ nr_copy_pages = info->image_pages;
+ nr_meta_pages = info->pages - info->image_pages - 1;
+ }
+ return error;
+}
+
+/**
+ * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
+ * the corresponding bit in the memory bitmap @bm
+ */
+static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+ if (unlikely(buf[j] == BM_END_OF_MAP))
+ break;
+
+ /* Extract and buffer page key for data page (s390 only). */
+ page_key_memorize(buf + j);
+
+ if (memory_bm_pfn_present(bm, buf[j]))
+ memory_bm_set_bit(bm, buf[j]);
+ else
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/* List of "safe" pages that may be used to store data loaded from the suspend
+ * image
+ */
+static struct linked_page *safe_pages_list;
+
+#ifdef CONFIG_HIGHMEM
+/* struct highmem_pbe is used for creating the list of highmem pages that
+ * should be restored atomically during the resume from disk, because the page
+ * frames they have occupied before the suspend are in use.
+ */
+struct highmem_pbe {
+ struct page *copy_page; /* data is here now */
+ struct page *orig_page; /* data was here before the suspend */
+ struct highmem_pbe *next;
+};
+
+/* List of highmem PBEs needed for restoring the highmem pages that were
+ * allocated before the suspend and included in the suspend image, but have
+ * also been allocated by the "resume" kernel, so their contents cannot be
+ * written directly to their "original" page frames.
+ */
+static struct highmem_pbe *highmem_pblist;
+
+/**
+ * count_highmem_image_pages - compute the number of highmem pages in the
+ * suspend image. The bits in the memory bitmap @bm that correspond to the
+ * image pages are assumed to be set.
+ */
+
+static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
+{
+ unsigned long pfn;
+ unsigned int cnt = 0;
+
+ memory_bm_position_reset(bm);
+ pfn = memory_bm_next_pfn(bm);
+ while (pfn != BM_END_OF_MAP) {
+ if (PageHighMem(pfn_to_page(pfn)))
+ cnt++;
+
+ pfn = memory_bm_next_pfn(bm);
+ }
+ return cnt;
+}
+
+/**
+ * prepare_highmem_image - try to allocate as many highmem pages as
+ * there are highmem image pages (@nr_highmem_p points to the variable
+ * containing the number of highmem image pages). The pages that are
+ * "safe" (ie. will not be overwritten when the suspend image is
+ * restored) have the corresponding bits set in @bm (it must be
+ * unitialized).
+ *
+ * NOTE: This function should not be called if there are no highmem
+ * image pages.
+ */
+
+static unsigned int safe_highmem_pages;
+
+static struct memory_bitmap *safe_highmem_bm;
+
+static int
+prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
+{
+ unsigned int to_alloc;
+
+ if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
+ return -ENOMEM;
+
+ if (get_highmem_buffer(PG_SAFE))
+ return -ENOMEM;
+
+ to_alloc = count_free_highmem_pages();
+ if (to_alloc > *nr_highmem_p)
+ to_alloc = *nr_highmem_p;
+ else
+ *nr_highmem_p = to_alloc;
+
+ safe_highmem_pages = 0;
+ while (to_alloc-- > 0) {
+ struct page *page;
+
+ page = alloc_page(__GFP_HIGHMEM);
+ if (!swsusp_page_is_free(page)) {
+ /* The page is "safe", set its bit the bitmap */
+ memory_bm_set_bit(bm, page_to_pfn(page));
+ safe_highmem_pages++;
+ }
+ /* Mark the page as allocated */
+ swsusp_set_page_forbidden(page);
+ swsusp_set_page_free(page);
+ }
+ memory_bm_position_reset(bm);
+ safe_highmem_bm = bm;
+ return 0;
+}
+
+/**
+ * get_highmem_page_buffer - for given highmem image page find the buffer
+ * that suspend_write_next() should set for its caller to write to.
+ *
+ * If the page is to be saved to its "original" page frame or a copy of
+ * the page is to be made in the highmem, @buffer is returned. Otherwise,
+ * the copy of the page is to be made in normal memory, so the address of
+ * the copy is returned.
+ *
+ * If @buffer is returned, the caller of suspend_write_next() will write
+ * the page's contents to @buffer, so they will have to be copied to the
+ * right location on the next call to suspend_write_next() and it is done
+ * with the help of copy_last_highmem_page(). For this purpose, if
+ * @buffer is returned, @last_highmem page is set to the page to which
+ * the data will have to be copied from @buffer.
+ */
+
+static struct page *last_highmem_page;
+
+static void *
+get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
+{
+ struct highmem_pbe *pbe;
+ void *kaddr;
+
+ if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
+ /* We have allocated the "original" page frame and we can
+ * use it directly to store the loaded page.
+ */
+ last_highmem_page = page;
+ return buffer;
+ }
+ /* The "original" page frame has not been allocated and we have to
+ * use a "safe" page frame to store the loaded page.
+ */
+ pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
+ if (!pbe) {
+ swsusp_free();
+ return ERR_PTR(-ENOMEM);
+ }
+ pbe->orig_page = page;
+ if (safe_highmem_pages > 0) {
+ struct page *tmp;
+
+ /* Copy of the page will be stored in high memory */
+ kaddr = buffer;
+ tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
+ safe_highmem_pages--;
+ last_highmem_page = tmp;
+ pbe->copy_page = tmp;
+ } else {
+ /* Copy of the page will be stored in normal memory */
+ kaddr = safe_pages_list;
+ safe_pages_list = safe_pages_list->next;
+ pbe->copy_page = virt_to_page(kaddr);
+ }
+ pbe->next = highmem_pblist;
+ highmem_pblist = pbe;
+ return kaddr;
+}
+
+/**
+ * copy_last_highmem_page - copy the contents of a highmem image from
+ * @buffer, where the caller of snapshot_write_next() has place them,
+ * to the right location represented by @last_highmem_page .
+ */
+
+static void copy_last_highmem_page(void)
+{
+ if (last_highmem_page) {
+ void *dst;
+
+ dst = kmap_atomic(last_highmem_page);
+ 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 */
+
+/**
+ * prepare_image - use the memory bitmap @bm to mark the pages that will
+ * be overwritten in the process of restoring the system memory state
+ * from the suspend image ("unsafe" pages) and allocate memory for the
+ * image.
+ *
+ * The idea is to allocate a new memory bitmap first and then allocate
+ * as many pages as needed for the image data, but not to assign these
+ * pages to specific tasks initially. Instead, we just mark them as
+ * allocated and create a lists of "safe" pages that will be used
+ * later. On systems with high memory a list of "safe" highmem pages is
+ * also created.
+ */
+
+#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
+
+static int
+prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
+{
+ unsigned int nr_pages, nr_highmem;
+ struct linked_page *sp_list, *lp;
+ int error;
+
+ /* If there is no highmem, the buffer will not be necessary */
+ free_image_page(buffer, PG_UNSAFE_CLEAR);
+ buffer = NULL;
+
+ nr_highmem = count_highmem_image_pages(bm);
+ error = mark_unsafe_pages(bm);
+ if (error)
+ goto Free;
+
+ error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
+ if (error)
+ goto Free;
+
+ duplicate_memory_bitmap(new_bm, bm);
+ memory_bm_free(bm, PG_UNSAFE_KEEP);
+ if (nr_highmem > 0) {
+ error = prepare_highmem_image(bm, &nr_highmem);
+ if (error)
+ goto Free;
+ }
+ /* Reserve some safe pages for potential later use.
+ *
+ * NOTE: This way we make sure there will be enough safe pages for the
+ * chain_alloc() in get_buffer(). It is a bit wasteful, but
+ * nr_copy_pages cannot be greater than 50% of the memory anyway.
+ */
+ sp_list = NULL;
+ /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
+ nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
+ nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
+ while (nr_pages > 0) {
+ lp = get_image_page(GFP_ATOMIC, PG_SAFE);
+ if (!lp) {
+ error = -ENOMEM;
+ goto Free;
+ }
+ lp->next = sp_list;
+ sp_list = lp;
+ nr_pages--;
+ }
+ /* Preallocate memory for the image */
+ safe_pages_list = NULL;
+ nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
+ while (nr_pages > 0) {
+ lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
+ if (!lp) {
+ error = -ENOMEM;
+ goto Free;
+ }
+ if (!swsusp_page_is_free(virt_to_page(lp))) {
+ /* The page is "safe", add it to the list */
+ lp->next = safe_pages_list;
+ safe_pages_list = lp;
+ }
+ /* Mark the page as allocated */
+ swsusp_set_page_forbidden(virt_to_page(lp));
+ swsusp_set_page_free(virt_to_page(lp));
+ nr_pages--;
+ }
+ /* Free the reserved safe pages so that chain_alloc() can use them */
+ while (sp_list) {
+ lp = sp_list->next;
+ free_image_page(sp_list, PG_UNSAFE_CLEAR);
+ sp_list = lp;
+ }
+ return 0;
+
+ Free:
+ swsusp_free();
+ return error;
+}
+
+/**
+ * get_buffer - compute the address that snapshot_write_next() should
+ * set for its caller to write to.
+ */
+
+static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
+{
+ struct pbe *pbe;
+ struct page *page;
+ unsigned long pfn = memory_bm_next_pfn(bm);
+
+ if (pfn == BM_END_OF_MAP)
+ return ERR_PTR(-EFAULT);
+
+ page = pfn_to_page(pfn);
+ if (PageHighMem(page))
+ return get_highmem_page_buffer(page, ca);
+
+ if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
+ /* We have allocated the "original" page frame and we can
+ * use it directly to store the loaded page.
+ */
+ return page_address(page);
+
+ /* The "original" page frame has not been allocated and we have to
+ * use a "safe" page frame to store the loaded page.
+ */
+ pbe = chain_alloc(ca, sizeof(struct pbe));
+ if (!pbe) {
+ swsusp_free();
+ return ERR_PTR(-ENOMEM);
+ }
+ pbe->orig_address = page_address(page);
+ pbe->address = safe_pages_list;
+ safe_pages_list = safe_pages_list->next;
+ pbe->next = restore_pblist;
+ restore_pblist = pbe;
+ return pbe->address;
+}
+
+/**
+ * snapshot_write_next - used for writing the system memory snapshot.
+ *
+ * On the first call to it @handle should point to a zeroed
+ * snapshot_handle structure. The structure gets updated and a pointer
+ * to it should be passed to this function every next time.
+ *
+ * On success the function returns a positive number. Then, the caller
+ * is allowed to write up to the returned number of bytes to the memory
+ * location computed by the data_of() macro.
+ *
+ * The function returns 0 to indicate the "end of file" condition,
+ * and a negative number is returned on error. In such cases the
+ * structure pointed to by @handle is not updated and should not be used
+ * any more.
+ */
+
+int snapshot_write_next(struct snapshot_handle *handle)
+{
+ static struct chain_allocator ca;
+ int error = 0;
+
+ /* Check if we have already loaded the entire image */
+ if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
+ return 0;
+
+ handle->sync_read = 1;
+
+ if (!handle->cur) {
+ if (!buffer)
+ /* This makes the buffer be freed by swsusp_free() */
+ buffer = get_image_page(GFP_ATOMIC, PG_ANY);
+
+ if (!buffer)
+ return -ENOMEM;
+
+ handle->buffer = buffer;
+ } else if (handle->cur == 1) {
+ error = load_header(buffer);
+ if (error)
+ return error;
+
+ error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
+ if (error)
+ return error;
+
+ /* Allocate buffer for page keys. */
+ error = page_key_alloc(nr_copy_pages);
+ if (error)
+ return error;
+
+ } else if (handle->cur <= nr_meta_pages + 1) {
+ error = unpack_orig_pfns(buffer, ©_bm);
+ if (error)
+ return error;
+
+ if (handle->cur == nr_meta_pages + 1) {
+ error = prepare_image(&orig_bm, ©_bm);
+ if (error)
+ return error;
+
+ chain_init(&ca, GFP_ATOMIC, PG_SAFE);
+ memory_bm_position_reset(&orig_bm);
+ restore_pblist = NULL;
+ handle->buffer = get_buffer(&orig_bm, &ca);
+ handle->sync_read = 0;
+ if (IS_ERR(handle->buffer))
+ return PTR_ERR(handle->buffer);
+ }
+ } else {
+ copy_last_highmem_page();
+ /* Restore page key for data page (s390 only). */
+ page_key_write(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 - must be called after the last call to
+ * snapshot_write_next() in case the last page in the image happens
+ * to be a highmem page and its contents should be stored in the
+ * highmem. Additionally, it releases the memory that will not be
+ * used any more.
+ */
+
+void snapshot_write_finalize(struct snapshot_handle *handle)
+{
+ copy_last_highmem_page();
+ /* Restore page key for data page (s390 only). */
+ page_key_write(handle->buffer);
+ page_key_free();
+ /* Free only if we have loaded the image entirely */
+ if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
+ memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
+ free_highmem_data();
+ }
+}
+
+int snapshot_image_loaded(struct snapshot_handle *handle)
+{
+ return !(!nr_copy_pages || !last_highmem_page_copied() ||
+ handle->cur <= nr_meta_pages + nr_copy_pages);
+}
+
+#ifdef CONFIG_HIGHMEM
+/* Assumes that @buf is ready and points to a "safe" page */
+static inline void
+swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
+{
+ void *kaddr1, *kaddr2;
+
+ kaddr1 = kmap_atomic(p1);
+ kaddr2 = kmap_atomic(p2);
+ copy_page(buf, kaddr1);
+ copy_page(kaddr1, kaddr2);
+ copy_page(kaddr2, buf);
+ kunmap_atomic(kaddr2);
+ kunmap_atomic(kaddr1);
+}
+
+/**
+ * restore_highmem - for each highmem page that was allocated before
+ * the suspend and included in the suspend image, and also has been
+ * allocated by the "resume" kernel swap its current (ie. "before
+ * resume") contents with the previous (ie. "before suspend") one.
+ *
+ * If the resume eventually fails, we can call this function once
+ * again and restore the "before resume" highmem state.
+ */
+
+int restore_highmem(void)
+{
+ struct highmem_pbe *pbe = highmem_pblist;
+ void *buf;
+
+ if (!pbe)
+ return 0;
+
+ buf = get_image_page(GFP_ATOMIC, PG_SAFE);
+ if (!buf)
+ return -ENOMEM;
+
+ while (pbe) {
+ swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
+ pbe = pbe->next;
+ }
+ free_image_page(buf, PG_UNSAFE_CLEAR);
+ return 0;
+}
+#endif /* CONFIG_HIGHMEM */
Code Review / kvmfornfv.git / blobdiff