/*
|
* 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.
|
*
|
*/
|
|
#define pr_fmt(fmt) "PM: " fmt
|
|
#include <linux/version.h>
|
#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/suspend.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
|
#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
|
#include <linux/nmi.h>
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#include <linux/syscalls.h>
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#include <linux/console.h>
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#include <linux/highmem.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/compiler.h>
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#include <linux/ktime.h>
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#include <linux/set_memory.h>
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|
#include <linux/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include "power.h"
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#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
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static bool hibernate_restore_protection;
|
static bool hibernate_restore_protection_active;
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|
void enable_restore_image_protection(void)
|
{
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hibernate_restore_protection = true;
|
}
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static inline void hibernate_restore_protection_begin(void)
|
{
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hibernate_restore_protection_active = hibernate_restore_protection;
|
}
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static inline void hibernate_restore_protection_end(void)
|
{
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hibernate_restore_protection_active = false;
|
}
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static inline void hibernate_restore_protect_page(void *page_address)
|
{
|
if (hibernate_restore_protection_active)
|
set_memory_ro((unsigned long)page_address, 1);
|
}
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|
static inline void hibernate_restore_unprotect_page(void *page_address)
|
{
|
if (hibernate_restore_protection_active)
|
set_memory_rw((unsigned long)page_address, 1);
|
}
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#else
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static inline void hibernate_restore_protection_begin(void) {}
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static inline void hibernate_restore_protection_end(void) {}
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static inline void hibernate_restore_protect_page(void *page_address) {}
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static inline void hibernate_restore_unprotect_page(void *page_address) {}
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#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
|
|
static int swsusp_page_is_free(struct page *);
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static void swsusp_set_page_forbidden(struct page *);
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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;
|
}
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|
/*
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* 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.
|
*/
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unsigned long image_size;
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void __init hibernate_image_size_init(void)
|
{
|
image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE;
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}
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/*
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* 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.
|
*/
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struct pbe *restore_pblist;
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/* struct linked_page is used to build chains of pages */
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#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
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struct linked_page {
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struct linked_page *next;
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char data[LINKED_PAGE_DATA_SIZE];
|
} __packed;
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/*
|
* 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.
|
*/
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static struct linked_page *safe_pages_list;
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/* Pointer to an auxiliary buffer (1 page) */
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static void *buffer;
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#define PG_ANY 0
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#define PG_SAFE 1
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#define PG_UNSAFE_CLEAR 1
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#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;
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|
res = (void *)get_zeroed_page(gfp_mask);
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if (safe_needed)
|
while (res && swsusp_page_is_free(virt_to_page(res))) {
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/* The page is unsafe, mark it for swsusp_free() */
|
swsusp_set_page_forbidden(virt_to_page(res));
|
allocated_unsafe_pages++;
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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;
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}
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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;
|
}
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return get_image_page(gfp_mask, PG_SAFE);
|
}
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|
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);
|
}
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|
static inline void free_list_of_pages(struct linked_page *list,
|
int clear_page_nosave)
|
{
|
while (list) {
|
struct linked_page *lp = list->next;
|
|
free_image_page(list, clear_page_nosave);
|
list = lp;
|
}
|
}
|
|
/*
|
* struct chain_allocator is used for allocating small objects out of
|
* a linked list of pages called 'the chain'.
|
*
|
* The chain grows each time when there is no room for a new object in
|
* the current page. The allocated objects cannot be freed individually.
|
* It is only possible to free them all at once, by freeing the entire
|
* chain.
|
*
|
* NOTE: The chain allocator may be inefficient if the allocated objects
|
* are not much smaller than PAGE_SIZE.
|
*/
|
struct chain_allocator {
|
struct linked_page *chain; /* the chain */
|
unsigned int used_space; /* total size of objects allocated out
|
of the current page */
|
gfp_t gfp_mask; /* mask for allocating pages */
|
int safe_needed; /* if set, only "safe" pages are allocated */
|
};
|
|
static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
|
int safe_needed)
|
{
|
ca->chain = NULL;
|
ca->used_space = LINKED_PAGE_DATA_SIZE;
|
ca->gfp_mask = gfp_mask;
|
ca->safe_needed = safe_needed;
|
}
|
|
static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
|
{
|
void *ret;
|
|
if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
|
struct linked_page *lp;
|
|
lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
|
get_image_page(ca->gfp_mask, PG_ANY);
|
if (!lp)
|
return NULL;
|
|
lp->next = ca->chain;
|
ca->chain = lp;
|
ca->used_space = 0;
|
}
|
ret = ca->chain->data + ca->used_space;
|
ca->used_space += size;
|
return ret;
|
}
|
|
/**
|
* Data types related to memory bitmaps.
|
*
|
* Memory bitmap is a structure consiting of many linked lists of
|
* objects. The main list's elements are of type struct zone_bitmap
|
* and each of them corresonds to one zone. For each zone bitmap
|
* object there is a list of objects of type struct bm_block that
|
* represent each blocks of bitmap in which information is stored.
|
*
|
* struct memory_bitmap contains a pointer to the main list of zone
|
* bitmap objects, a struct bm_position used for browsing the bitmap,
|
* and a pointer to the list of pages used for allocating all of the
|
* zone bitmap objects and bitmap block objects.
|
*
|
* NOTE: It has to be possible to lay out the bitmap in memory
|
* using only allocations of order 0. Additionally, the bitmap is
|
* designed to work with arbitrary number of zones (this is over the
|
* top for now, but let's avoid making unnecessary assumptions ;-).
|
*
|
* struct zone_bitmap contains a pointer to a list of bitmap block
|
* objects and a pointer to the bitmap block object that has been
|
* most recently used for setting bits. Additionally, it contains the
|
* PFNs that correspond to the start and end of the represented zone.
|
*
|
* struct bm_block contains a pointer to the memory page in which
|
* information is stored (in the form of a block of bitmap)
|
* It also contains the pfns that correspond to the start and end of
|
* the represented memory area.
|
*
|
* The memory bitmap is organized as a radix tree to guarantee fast random
|
* access to the bits. There is one radix tree for each zone (as returned
|
* from create_mem_extents).
|
*
|
* One radix tree is represented by one struct mem_zone_bm_rtree. There are
|
* two linked lists for the nodes of the tree, one for the inner nodes and
|
* one for the leave nodes. The linked leave nodes are used for fast linear
|
* access of the memory bitmap.
|
*
|
* The struct rtree_node represents one node of the radix tree.
|
*/
|
|
#define BM_END_OF_MAP (~0UL)
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|
#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 */
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struct rtree_node *rtree; /* Radix Tree Root */
|
int levels; /* Number of Radix Tree Levels */
|
unsigned int blocks; /* Number of Bitmap Blocks */
|
};
|
|
/* strcut bm_position is used for browsing memory bitmaps */
|
|
struct bm_position {
|
struct mem_zone_bm_rtree *zone;
|
struct rtree_node *node;
|
unsigned long node_pfn;
|
int node_bit;
|
};
|
|
struct memory_bitmap {
|
struct list_head zones;
|
struct linked_page *p_list; /* list of pages used to store zone
|
bitmap objects and bitmap block
|
objects */
|
struct bm_position cur; /* most recently used bit position */
|
};
|
|
/* Functions that operate on memory bitmaps */
|
|
#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
|
#if BITS_PER_LONG == 32
|
#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
|
#else
|
#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
|
#endif
|
#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
|
|
/**
|
* alloc_rtree_node - Allocate a new node and add it to the radix tree.
|
*
|
* This function is used to allocate inner nodes as well as the
|
* leave nodes of the radix tree. It also adds the node to the
|
* corresponding linked list passed in by the *list parameter.
|
*/
|
static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
|
struct chain_allocator *ca,
|
struct list_head *list)
|
{
|
struct rtree_node *node;
|
|
node = chain_alloc(ca, sizeof(struct rtree_node));
|
if (!node)
|
return NULL;
|
|
node->data = get_image_page(gfp_mask, safe_needed);
|
if (!node->data)
|
return NULL;
|
|
list_add_tail(&node->list, list);
|
|
return node;
|
}
|
|
/**
|
* add_rtree_block - Add a new leave node to the radix tree.
|
*
|
* The leave nodes need to be allocated in order to keep the leaves
|
* linked list in order. This is guaranteed by the zone->blocks
|
* counter.
|
*/
|
static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
|
int safe_needed, struct chain_allocator *ca)
|
{
|
struct rtree_node *node, *block, **dst;
|
unsigned int levels_needed, block_nr;
|
int i;
|
|
block_nr = zone->blocks;
|
levels_needed = 0;
|
|
/* How many levels do we need for this block nr? */
|
while (block_nr) {
|
levels_needed += 1;
|
block_nr >>= BM_RTREE_LEVEL_SHIFT;
|
}
|
|
/* Make sure the rtree has enough levels */
|
for (i = zone->levels; i < levels_needed; i++) {
|
node = alloc_rtree_node(gfp_mask, safe_needed, ca,
|
&zone->nodes);
|
if (!node)
|
return -ENOMEM;
|
|
node->data[0] = (unsigned long)zone->rtree;
|
zone->rtree = node;
|
zone->levels += 1;
|
}
|
|
/* Allocate new block */
|
block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
|
if (!block)
|
return -ENOMEM;
|
|
/* Now walk the rtree to insert the block */
|
node = zone->rtree;
|
dst = &zone->rtree;
|
block_nr = zone->blocks;
|
for (i = zone->levels; i > 0; i--) {
|
int index;
|
|
if (!node) {
|
node = alloc_rtree_node(gfp_mask, safe_needed, ca,
|
&zone->nodes);
|
if (!node)
|
return -ENOMEM;
|
*dst = node;
|
}
|
|
index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
|
index &= BM_RTREE_LEVEL_MASK;
|
dst = (struct rtree_node **)&((*dst)->data[index]);
|
node = *dst;
|
}
|
|
zone->blocks += 1;
|
*dst = block;
|
|
return 0;
|
}
|
|
static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
|
int clear_nosave_free);
|
|
/**
|
* create_zone_bm_rtree - Create a radix tree for one zone.
|
*
|
* Allocated the mem_zone_bm_rtree structure and initializes it.
|
* This function also allocated and builds the radix tree for the
|
* zone.
|
*/
|
static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
|
int safe_needed,
|
struct chain_allocator *ca,
|
unsigned long start,
|
unsigned long end)
|
{
|
struct mem_zone_bm_rtree *zone;
|
unsigned int i, nr_blocks;
|
unsigned long pages;
|
|
pages = end - start;
|
zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
|
if (!zone)
|
return NULL;
|
|
INIT_LIST_HEAD(&zone->nodes);
|
INIT_LIST_HEAD(&zone->leaves);
|
zone->start_pfn = start;
|
zone->end_pfn = end;
|
nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
|
|
for (i = 0; i < nr_blocks; i++) {
|
if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
|
free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
|
return NULL;
|
}
|
}
|
|
return zone;
|
}
|
|
/**
|
* free_zone_bm_rtree - Free the memory of the radix tree.
|
*
|
* Free all node pages of the radix tree. The mem_zone_bm_rtree
|
* structure itself is not freed here nor are the rtree_node
|
* structs.
|
*/
|
static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
|
int clear_nosave_free)
|
{
|
struct rtree_node *node;
|
|
list_for_each_entry(node, &zone->nodes, list)
|
free_image_page(node->data, clear_nosave_free);
|
|
list_for_each_entry(node, &zone->leaves, list)
|
free_image_page(node->data, clear_nosave_free);
|
}
|
|
static void memory_bm_position_reset(struct memory_bitmap *bm)
|
{
|
bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
|
list);
|
bm->cur.node = list_entry(bm->cur.zone->leaves.next,
|
struct rtree_node, list);
|
bm->cur.node_pfn = 0;
|
bm->cur.node_bit = 0;
|
}
|
|
static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
|
|
struct mem_extent {
|
struct list_head hook;
|
unsigned long start;
|
unsigned long end;
|
};
|
|
/**
|
* free_mem_extents - Free a list of memory extents.
|
* @list: List of extents to free.
|
*/
|
static void free_mem_extents(struct list_head *list)
|
{
|
struct mem_extent *ext, *aux;
|
|
list_for_each_entry_safe(ext, aux, list, hook) {
|
list_del(&ext->hook);
|
kfree(ext);
|
}
|
}
|
|
/**
|
* create_mem_extents - Create a list of memory extents.
|
* @list: List to put the extents into.
|
* @gfp_mask: Mask to use for memory allocations.
|
*
|
* The extents represent contiguous ranges of PFNs.
|
*/
|
static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
|
{
|
struct zone *zone;
|
|
INIT_LIST_HEAD(list);
|
|
for_each_populated_zone(zone) {
|
unsigned long zone_start, zone_end;
|
struct mem_extent *ext, *cur, *aux;
|
|
zone_start = zone->zone_start_pfn;
|
zone_end = zone_end_pfn(zone);
|
|
list_for_each_entry(ext, list, hook)
|
if (zone_start <= ext->end)
|
break;
|
|
if (&ext->hook == list || zone_end < ext->start) {
|
/* New extent is necessary */
|
struct mem_extent *new_ext;
|
|
new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
|
if (!new_ext) {
|
free_mem_extents(list);
|
return -ENOMEM;
|
}
|
new_ext->start = zone_start;
|
new_ext->end = zone_end;
|
list_add_tail(&new_ext->hook, &ext->hook);
|
continue;
|
}
|
|
/* Merge this zone's range of PFNs with the existing one */
|
if (zone_start < ext->start)
|
ext->start = zone_start;
|
if (zone_end > ext->end)
|
ext->end = zone_end;
|
|
/* More merging may be possible */
|
cur = ext;
|
list_for_each_entry_safe_continue(cur, aux, list, hook) {
|
if (zone_end < cur->start)
|
break;
|
if (zone_end < cur->end)
|
ext->end = cur->end;
|
list_del(&cur->hook);
|
kfree(cur);
|
}
|
}
|
|
return 0;
|
}
|
|
/**
|
* memory_bm_create - Allocate memory for a memory bitmap.
|
*/
|
static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
|
int safe_needed)
|
{
|
struct chain_allocator ca;
|
struct list_head mem_extents;
|
struct mem_extent *ext;
|
int error;
|
|
chain_init(&ca, gfp_mask, safe_needed);
|
INIT_LIST_HEAD(&bm->zones);
|
|
error = create_mem_extents(&mem_extents, gfp_mask);
|
if (error)
|
return error;
|
|
list_for_each_entry(ext, &mem_extents, hook) {
|
struct mem_zone_bm_rtree *zone;
|
|
zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
|
ext->start, ext->end);
|
if (!zone) {
|
error = -ENOMEM;
|
goto Error;
|
}
|
list_add_tail(&zone->list, &bm->zones);
|
}
|
|
bm->p_list = ca.chain;
|
memory_bm_position_reset(bm);
|
Exit:
|
free_mem_extents(&mem_extents);
|
return error;
|
|
Error:
|
bm->p_list = ca.chain;
|
memory_bm_free(bm, PG_UNSAFE_CLEAR);
|
goto Exit;
|
}
|
|
/**
|
* memory_bm_free - Free memory occupied by the memory bitmap.
|
* @bm: Memory bitmap.
|
*/
|
static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
|
{
|
struct mem_zone_bm_rtree *zone;
|
|
list_for_each_entry(zone, &bm->zones, list)
|
free_zone_bm_rtree(zone, clear_nosave_free);
|
|
free_list_of_pages(bm->p_list, clear_nosave_free);
|
|
INIT_LIST_HEAD(&bm->zones);
|
}
|
|
/**
|
* memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
|
*
|
* Find the bit in memory bitmap @bm that corresponds to the given PFN.
|
* The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
|
*
|
* Walk the radix tree to find the page containing the bit that represents @pfn
|
* and return the position of the bit in @addr and @bit_nr.
|
*/
|
static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
|
void **addr, unsigned int *bit_nr)
|
{
|
struct mem_zone_bm_rtree *curr, *zone;
|
struct rtree_node *node;
|
int i, block_nr;
|
|
zone = bm->cur.zone;
|
|
if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
|
goto zone_found;
|
|
zone = NULL;
|
|
/* Find the right zone */
|
list_for_each_entry(curr, &bm->zones, list) {
|
if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
|
zone = curr;
|
break;
|
}
|
}
|
|
if (!zone)
|
return -EFAULT;
|
|
zone_found:
|
/*
|
* We have found the zone. Now walk the radix tree to find the leaf node
|
* for our PFN.
|
*/
|
|
/*
|
* If the zone we wish to scan is the 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;
|
|
/* Set return values */
|
*addr = node->data;
|
*bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
|
|
return 0;
|
}
|
|
static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
|
{
|
void *addr;
|
unsigned int bit;
|
int error;
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
BUG_ON(error);
|
set_bit(bit, addr);
|
}
|
|
static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
|
{
|
void *addr;
|
unsigned int bit;
|
int error;
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
if (!error)
|
set_bit(bit, addr);
|
|
return error;
|
}
|
|
static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
|
{
|
void *addr;
|
unsigned int bit;
|
int error;
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
BUG_ON(error);
|
clear_bit(bit, addr);
|
}
|
|
static void memory_bm_clear_current(struct memory_bitmap *bm)
|
{
|
int bit;
|
|
bit = max(bm->cur.node_bit - 1, 0);
|
clear_bit(bit, bm->cur.node->data);
|
}
|
|
static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
|
{
|
void *addr;
|
unsigned int bit;
|
int error;
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
BUG_ON(error);
|
return test_bit(bit, addr);
|
}
|
|
static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
|
{
|
void *addr;
|
unsigned int bit;
|
|
return !memory_bm_find_bit(bm, pfn, &addr, &bit);
|
}
|
|
/*
|
* rtree_next_node - Jump to the next leaf node.
|
*
|
* Set the position to the beginning of the next node in the
|
* memory bitmap. This is either the next node in the current
|
* zone's radix tree or the first node in the radix tree of the
|
* next zone.
|
*
|
* Return true if there is a next node, false otherwise.
|
*/
|
static bool rtree_next_node(struct memory_bitmap *bm)
|
{
|
if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
|
bm->cur.node = list_entry(bm->cur.node->list.next,
|
struct rtree_node, list);
|
bm->cur.node_pfn += BM_BITS_PER_BLOCK;
|
bm->cur.node_bit = 0;
|
touch_softlockup_watchdog();
|
return true;
|
}
|
|
/* No more nodes, goto next zone */
|
if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
|
bm->cur.zone = list_entry(bm->cur.zone->list.next,
|
struct mem_zone_bm_rtree, list);
|
bm->cur.node = list_entry(bm->cur.zone->leaves.next,
|
struct rtree_node, list);
|
bm->cur.node_pfn = 0;
|
bm->cur.node_bit = 0;
|
return true;
|
}
|
|
/* No more zones */
|
return false;
|
}
|
|
/**
|
* memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
|
* @bm: Memory bitmap.
|
*
|
* Starting from the last returned position this function searches for the next
|
* set bit in @bm and returns the PFN represented by it. If no more bits are
|
* set, BM_END_OF_MAP is returned.
|
*
|
* It is required to run memory_bm_position_reset() before the first call to
|
* this function for the given memory bitmap.
|
*/
|
static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
|
{
|
unsigned long bits, pfn, pages;
|
int bit;
|
|
do {
|
pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
|
bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
|
bit = find_next_bit(bm->cur.node->data, bits,
|
bm->cur.node_bit);
|
if (bit < bits) {
|
pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
|
bm->cur.node_bit = bit + 1;
|
return pfn;
|
}
|
} while (rtree_next_node(bm));
|
|
return BM_END_OF_MAP;
|
}
|
|
/*
|
* This structure represents a range of page frames the contents of which
|
* should not be saved during hibernation.
|
*/
|
struct nosave_region {
|
struct list_head list;
|
unsigned long start_pfn;
|
unsigned long end_pfn;
|
};
|
|
static LIST_HEAD(nosave_regions);
|
|
static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
|
{
|
struct rtree_node *node;
|
|
list_for_each_entry(node, &zone->nodes, list)
|
recycle_safe_page(node->data);
|
|
list_for_each_entry(node, &zone->leaves, list)
|
recycle_safe_page(node->data);
|
}
|
|
static void memory_bm_recycle(struct memory_bitmap *bm)
|
{
|
struct mem_zone_bm_rtree *zone;
|
struct linked_page *p_list;
|
|
list_for_each_entry(zone, &bm->zones, list)
|
recycle_zone_bm_rtree(zone);
|
|
p_list = bm->p_list;
|
while (p_list) {
|
struct linked_page *lp = p_list;
|
|
p_list = lp->next;
|
recycle_safe_page(lp);
|
}
|
}
|
|
/**
|
* register_nosave_region - Register a region of unsaveable memory.
|
*
|
* Register a range of page frames the contents of which should not be saved
|
* during hibernation (to be used in the early initialization code).
|
*/
|
void __init __register_nosave_region(unsigned long start_pfn,
|
unsigned long end_pfn, int use_kmalloc)
|
{
|
struct nosave_region *region;
|
|
if (start_pfn >= end_pfn)
|
return;
|
|
if (!list_empty(&nosave_regions)) {
|
/* Try to extend the previous region (they should be sorted) */
|
region = list_entry(nosave_regions.prev,
|
struct nosave_region, list);
|
if (region->end_pfn == start_pfn) {
|
region->end_pfn = end_pfn;
|
goto Report;
|
}
|
}
|
if (use_kmalloc) {
|
/* During init, this shouldn't fail */
|
region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
|
BUG_ON(!region);
|
} else {
|
/* This allocation cannot fail */
|
region = memblock_virt_alloc(sizeof(struct nosave_region), 0);
|
}
|
region->start_pfn = start_pfn;
|
region->end_pfn = end_pfn;
|
list_add_tail(®ion->list, &nosave_regions);
|
Report:
|
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");
|
}
|
|
void clear_free_pages(void)
|
{
|
struct memory_bitmap *bm = free_pages_map;
|
unsigned long pfn;
|
|
if (WARN_ON(!(free_pages_map)))
|
return;
|
|
if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || 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_highpage(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;
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
/**
|
* count_free_highmem_pages - Compute the total number of free highmem pages.
|
*
|
* The returned number is system-wide.
|
*/
|
static unsigned int count_free_highmem_pages(void)
|
{
|
struct zone *zone;
|
unsigned int cnt = 0;
|
|
for_each_populated_zone(zone)
|
if (is_highmem(zone))
|
cnt += zone_page_state(zone, NR_FREE_PAGES);
|
|
return cnt;
|
}
|
|
/**
|
* saveable_highmem_page - Check if a highmem page is saveable.
|
*
|
* Determine whether a highmem page should be included in a hibernation image.
|
*
|
* We should save the page if it isn't Nosave or NosaveFree, or Reserved,
|
* and it isn't part of a free chunk of pages.
|
*/
|
static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
|
{
|
struct page *page;
|
|
if (!pfn_valid(pfn))
|
return NULL;
|
|
page = pfn_to_page(pfn);
|
if (page_zone(page) != zone)
|
return NULL;
|
|
BUG_ON(!PageHighMem(page));
|
|
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
|
PageReserved(page))
|
return NULL;
|
|
if (page_is_guard(page))
|
return NULL;
|
|
return page;
|
}
|
|
/**
|
* count_highmem_pages - Compute the total number of saveable highmem pages.
|
*/
|
static unsigned int count_highmem_pages(void)
|
{
|
struct zone *zone;
|
unsigned int n = 0;
|
|
for_each_populated_zone(zone) {
|
unsigned long pfn, max_zone_pfn;
|
|
if (!is_highmem(zone))
|
continue;
|
|
mark_free_pages(zone);
|
max_zone_pfn = zone_end_pfn(zone);
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
if (saveable_highmem_page(zone, pfn))
|
n++;
|
}
|
return n;
|
}
|
#else
|
static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
|
{
|
return NULL;
|
}
|
#endif /* CONFIG_HIGHMEM */
|
|
/**
|
* saveable_page - Check if the given page is saveable.
|
*
|
* Determine whether a non-highmem page should be included in a hibernation
|
* image.
|
*
|
* We should save the page if it isn't Nosave, and is not in the range
|
* of pages statically defined as 'unsaveable', and it isn't part of
|
* a free chunk of pages.
|
*/
|
static struct page *saveable_page(struct zone *zone, unsigned long pfn)
|
{
|
struct page *page;
|
|
if (!pfn_valid(pfn))
|
return NULL;
|
|
page = pfn_to_page(pfn);
|
if (page_zone(page) != zone)
|
return NULL;
|
|
BUG_ON(PageHighMem(page));
|
|
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
|
return NULL;
|
|
if (PageReserved(page)
|
&& (!kernel_page_present(page) || pfn_is_nosave(pfn)))
|
return NULL;
|
|
if (page_is_guard(page))
|
return NULL;
|
|
return page;
|
}
|
|
/**
|
* count_data_pages - Compute the total number of saveable non-highmem pages.
|
*/
|
static unsigned int count_data_pages(void)
|
{
|
struct zone *zone;
|
unsigned long pfn, max_zone_pfn;
|
unsigned int n = 0;
|
|
for_each_populated_zone(zone) {
|
if (is_highmem(zone))
|
continue;
|
|
mark_free_pages(zone);
|
max_zone_pfn = zone_end_pfn(zone);
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
if (saveable_page(zone, pfn))
|
n++;
|
}
|
return n;
|
}
|
|
/*
|
* This is needed, because copy_page and memcpy are not usable for copying
|
* task structs.
|
*/
|
static inline void do_copy_page(long *dst, long *src)
|
{
|
int n;
|
|
for (n = PAGE_SIZE / sizeof(long); n; n--)
|
*dst++ = *src++;
|
}
|
|
/**
|
* safe_copy_page - Copy a page in a safe way.
|
*
|
* Check if the page we are going to copy is marked as present in the kernel
|
* page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set
|
* and in that case kernel_page_present() always returns 'true').
|
*/
|
static void safe_copy_page(void *dst, struct page *s_page)
|
{
|
if (kernel_page_present(s_page)) {
|
do_copy_page(dst, page_address(s_page));
|
} else {
|
kernel_map_pages(s_page, 1, 1);
|
do_copy_page(dst, page_address(s_page));
|
kernel_map_pages(s_page, 1, 0);
|
}
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
|
{
|
return is_highmem(zone) ?
|
saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
|
}
|
|
static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
|
{
|
struct page *s_page, *d_page;
|
void *src, *dst;
|
|
s_page = pfn_to_page(src_pfn);
|
d_page = pfn_to_page(dst_pfn);
|
if (PageHighMem(s_page)) {
|
src = kmap_atomic(s_page);
|
dst = kmap_atomic(d_page);
|
do_copy_page(dst, src);
|
kunmap_atomic(dst);
|
kunmap_atomic(src);
|
} else {
|
if (PageHighMem(d_page)) {
|
/*
|
* The page pointed to by src may contain some kernel
|
* data modified by kmap_atomic()
|
*/
|
safe_copy_page(buffer, s_page);
|
dst = kmap_atomic(d_page);
|
copy_page(dst, buffer);
|
kunmap_atomic(dst);
|
} else {
|
safe_copy_page(page_address(d_page), s_page);
|
}
|
}
|
}
|
#else
|
#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
|
|
static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
|
{
|
safe_copy_page(page_address(pfn_to_page(dst_pfn)),
|
pfn_to_page(src_pfn));
|
}
|
#endif /* CONFIG_HIGHMEM */
|
|
static void copy_data_pages(struct memory_bitmap *copy_bm,
|
struct memory_bitmap *orig_bm)
|
{
|
struct zone *zone;
|
unsigned long pfn;
|
|
for_each_populated_zone(zone) {
|
unsigned long max_zone_pfn;
|
|
mark_free_pages(zone);
|
max_zone_pfn = zone_end_pfn(zone);
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
if (page_is_saveable(zone, pfn))
|
memory_bm_set_bit(orig_bm, pfn);
|
}
|
memory_bm_position_reset(orig_bm);
|
memory_bm_position_reset(copy_bm);
|
for(;;) {
|
pfn = memory_bm_next_pfn(orig_bm);
|
if (unlikely(pfn == BM_END_OF_MAP))
|
break;
|
copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
|
}
|
}
|
|
/* Total number of image pages */
|
static unsigned int nr_copy_pages;
|
/* Number of pages needed for saving the original pfns of the image pages */
|
static unsigned int nr_meta_pages;
|
/*
|
* Numbers of normal and highmem page frames allocated for hibernation image
|
* before suspending devices.
|
*/
|
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;
|
|
/**
|
* swsusp_free - Free pages allocated for hibernation image.
|
*
|
* Image pages are alocated before snapshot creation, so they need to be
|
* released after resume.
|
*/
|
void swsusp_free(void)
|
{
|
unsigned long fb_pfn, fr_pfn;
|
|
if (!forbidden_pages_map || !free_pages_map)
|
goto out;
|
|
memory_bm_position_reset(forbidden_pages_map);
|
memory_bm_position_reset(free_pages_map);
|
|
loop:
|
fr_pfn = memory_bm_next_pfn(free_pages_map);
|
fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
|
|
/*
|
* Find the next bit set in both bitmaps. This is guaranteed to
|
* terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
|
*/
|
do {
|
if (fb_pfn < fr_pfn)
|
fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
|
if (fr_pfn < fb_pfn)
|
fr_pfn = memory_bm_next_pfn(free_pages_map);
|
} while (fb_pfn != fr_pfn);
|
|
if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
|
struct page *page = pfn_to_page(fr_pfn);
|
|
memory_bm_clear_current(forbidden_pages_map);
|
memory_bm_clear_current(free_pages_map);
|
hibernate_restore_unprotect_page(page_address(page));
|
__free_page(page);
|
goto loop;
|
}
|
|
out:
|
nr_copy_pages = 0;
|
nr_meta_pages = 0;
|
restore_pblist = NULL;
|
buffer = NULL;
|
alloc_normal = 0;
|
alloc_highmem = 0;
|
hibernate_restore_protection_end();
|
}
|
|
/* Helper functions used for the shrinking of memory. */
|
|
#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
|
|
/**
|
* preallocate_image_pages - Allocate a number of pages for hibernation image.
|
* @nr_pages: Number of page frames to allocate.
|
* @mask: GFP flags to use for the allocation.
|
*
|
* Return value: Number of page frames actually allocated
|
*/
|
static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
|
{
|
unsigned long nr_alloc = 0;
|
|
while (nr_pages > 0) {
|
struct page *page;
|
|
page = alloc_image_page(mask);
|
if (!page)
|
break;
|
memory_bm_set_bit(©_bm, page_to_pfn(page));
|
if (PageHighMem(page))
|
alloc_highmem++;
|
else
|
alloc_normal++;
|
nr_pages--;
|
nr_alloc++;
|
}
|
|
return nr_alloc;
|
}
|
|
static unsigned long preallocate_image_memory(unsigned long nr_pages,
|
unsigned long avail_normal)
|
{
|
unsigned long alloc;
|
|
if (avail_normal <= alloc_normal)
|
return 0;
|
|
alloc = avail_normal - alloc_normal;
|
if (nr_pages < alloc)
|
alloc = nr_pages;
|
|
return preallocate_image_pages(alloc, GFP_IMAGE);
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
static unsigned long preallocate_image_highmem(unsigned long nr_pages)
|
{
|
return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
|
}
|
|
/**
|
* __fraction - Compute (an approximation of) x * (multiplier / base).
|
*/
|
static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
|
{
|
x *= multiplier;
|
do_div(x, base);
|
return (unsigned long)x;
|
}
|
|
static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
|
unsigned long highmem,
|
unsigned long total)
|
{
|
unsigned long alloc = __fraction(nr_pages, highmem, total);
|
|
return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
|
}
|
#else /* CONFIG_HIGHMEM */
|
static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
|
{
|
return 0;
|
}
|
|
static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
|
unsigned long highmem,
|
unsigned long total)
|
{
|
return 0;
|
}
|
#endif /* CONFIG_HIGHMEM */
|
|
/**
|
* free_unnecessary_pages - Release preallocated pages not needed for the image.
|
*/
|
static unsigned long free_unnecessary_pages(void)
|
{
|
unsigned long save, to_free_normal, to_free_highmem, free;
|
|
save = count_data_pages();
|
if (alloc_normal >= save) {
|
to_free_normal = alloc_normal - save;
|
save = 0;
|
} else {
|
to_free_normal = 0;
|
save -= alloc_normal;
|
}
|
save += count_highmem_pages();
|
if (alloc_highmem >= save) {
|
to_free_highmem = alloc_highmem - save;
|
} else {
|
to_free_highmem = 0;
|
save -= alloc_highmem;
|
if (to_free_normal > save)
|
to_free_normal -= save;
|
else
|
to_free_normal = 0;
|
}
|
free = to_free_normal + to_free_highmem;
|
|
memory_bm_position_reset(©_bm);
|
|
while (to_free_normal > 0 || to_free_highmem > 0) {
|
unsigned long pfn = memory_bm_next_pfn(©_bm);
|
struct page *page = pfn_to_page(pfn);
|
|
if (PageHighMem(page)) {
|
if (!to_free_highmem)
|
continue;
|
to_free_highmem--;
|
alloc_highmem--;
|
} else {
|
if (!to_free_normal)
|
continue;
|
to_free_normal--;
|
alloc_normal--;
|
}
|
memory_bm_clear_bit(©_bm, pfn);
|
swsusp_unset_page_forbidden(page);
|
swsusp_unset_page_free(page);
|
__free_page(page);
|
}
|
|
return free;
|
}
|
|
/**
|
* minimum_image_size - Estimate the minimum acceptable size of an image.
|
* @saveable: Number of saveable pages in the system.
|
*
|
* We want to avoid attempting to free too much memory too hard, so estimate the
|
* minimum acceptable size of a hibernation image to use as the lower limit for
|
* preallocating memory.
|
*
|
* We assume that the minimum image size should be proportional to
|
*
|
* [number of saveable pages] - [number of pages that can be freed in theory]
|
*
|
* where the second term is the sum of (1) reclaimable slab pages, (2) active
|
* and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
|
*/
|
static unsigned long minimum_image_size(unsigned long saveable)
|
{
|
unsigned long size;
|
|
size = global_node_page_state(NR_SLAB_RECLAIMABLE)
|
+ global_node_page_state(NR_ACTIVE_ANON)
|
+ global_node_page_state(NR_INACTIVE_ANON)
|
+ global_node_page_state(NR_ACTIVE_FILE)
|
+ global_node_page_state(NR_INACTIVE_FILE);
|
|
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;
|
|
pr_info("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();
|
pr_cont("done (allocated %lu pages)\n", pages);
|
swsusp_show_speed(start, stop, pages, "Allocated");
|
|
return 0;
|
|
err_out:
|
pr_cont("\n");
|
swsusp_free();
|
return -ENOMEM;
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
/**
|
* count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
|
*
|
* Compute the number of non-highmem pages that will be necessary for creating
|
* copies of highmem pages.
|
*/
|
static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
|
{
|
unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
|
|
if (free_highmem >= nr_highmem)
|
nr_highmem = 0;
|
else
|
nr_highmem -= free_highmem;
|
|
return nr_highmem;
|
}
|
#else
|
static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
|
#endif /* CONFIG_HIGHMEM */
|
|
/**
|
* enough_free_mem - Check if there is enough free memory for the image.
|
*/
|
static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
|
{
|
struct zone *zone;
|
unsigned int free = alloc_normal;
|
|
for_each_populated_zone(zone)
|
if (!is_highmem(zone))
|
free += zone_page_state(zone, NR_FREE_PAGES);
|
|
nr_pages += count_pages_for_highmem(nr_highmem);
|
pr_debug("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_image_pages - Allocate some highmem pages for the image.
|
*
|
* Try to allocate as many pages as needed, but if the number of free highmem
|
* pages is less than that, allocate them all.
|
*/
|
static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
|
unsigned int nr_highmem)
|
{
|
unsigned int to_alloc = count_free_highmem_pages();
|
|
if (to_alloc > nr_highmem)
|
to_alloc = nr_highmem;
|
|
nr_highmem -= to_alloc;
|
while (to_alloc-- > 0) {
|
struct page *page;
|
|
page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
|
memory_bm_set_bit(bm, page_to_pfn(page));
|
}
|
return nr_highmem;
|
}
|
#else
|
static inline int get_highmem_buffer(int safe_needed) { return 0; }
|
|
static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
|
unsigned int n) { return 0; }
|
#endif /* CONFIG_HIGHMEM */
|
|
/**
|
* swsusp_alloc - Allocate memory for hibernation image.
|
*
|
* We first try to allocate as many highmem pages as there are
|
* saveable highmem pages in the system. If that fails, we allocate
|
* non-highmem pages for the copies of the remaining highmem ones.
|
*
|
* In this approach it is likely that the copies of highmem pages will
|
* also be located in the high memory, because of the way in which
|
* copy_data_pages() works.
|
*/
|
static int swsusp_alloc(struct memory_bitmap *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 hibernation 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);
|
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);
|
|
pr_info("Hibernation image created (%d pages copied)\n", nr_pages);
|
|
return 0;
|
}
|
|
#ifndef CONFIG_ARCH_HIBERNATION_HEADER
|
static int init_header_complete(struct swsusp_info *info)
|
{
|
memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
|
info->version_code = LINUX_VERSION_CODE;
|
return 0;
|
}
|
|
static char *check_image_kernel(struct swsusp_info *info)
|
{
|
if (info->version_code != LINUX_VERSION_CODE)
|
return "kernel version";
|
if (strcmp(info->uts.sysname,init_utsname()->sysname))
|
return "system type";
|
if (strcmp(info->uts.release,init_utsname()->release))
|
return "kernel release";
|
if (strcmp(info->uts.version,init_utsname()->version))
|
return "version";
|
if (strcmp(info->uts.machine,init_utsname()->machine))
|
return "machine";
|
return NULL;
|
}
|
#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
|
|
unsigned long snapshot_get_image_size(void)
|
{
|
return nr_copy_pages + nr_meta_pages + 1;
|
}
|
|
static int init_header(struct swsusp_info *info)
|
{
|
memset(info, 0, sizeof(struct swsusp_info));
|
info->num_physpages = get_num_physpages();
|
info->image_pages = nr_copy_pages;
|
info->pages = snapshot_get_image_size();
|
info->size = info->pages;
|
info->size <<= PAGE_SHIFT;
|
return init_header_complete(info);
|
}
|
|
/**
|
* pack_pfns - Prepare PFNs for saving.
|
* @bm: Memory bitmap.
|
* @buf: Memory buffer to store the PFNs in.
|
*
|
* PFNs corresponding to set bits in @bm are stored in the area of memory
|
* pointed to by @buf (1 page at a time).
|
*/
|
static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
|
{
|
int j;
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
|
buf[j] = memory_bm_next_pfn(bm);
|
if (unlikely(buf[j] == BM_END_OF_MAP))
|
break;
|
/* Save page key for data page (s390 only). */
|
page_key_read(buf + j);
|
}
|
}
|
|
/**
|
* snapshot_read_next - Get the address to read the next image page from.
|
* @handle: Snapshot handle to be used for the reading.
|
*
|
* On the first call, @handle should point to a zeroed snapshot_handle
|
* structure. The structure gets populated then and a pointer to it should be
|
* passed to this function every next time.
|
*
|
* On success, the function returns a positive number. Then, the caller
|
* is allowed to read up to the returned number of bytes from the memory
|
* location computed by the data_of() macro.
|
*
|
* The function returns 0 to indicate the end of the data stream condition,
|
* and negative numbers are returned on errors. If that happens, the structure
|
* pointed to by @handle is not updated and should not be used any more.
|
*/
|
int snapshot_read_next(struct snapshot_handle *handle)
|
{
|
if (handle->cur > nr_meta_pages + nr_copy_pages)
|
return 0;
|
|
if (!buffer) {
|
/* This makes the buffer be freed by swsusp_free() */
|
buffer = get_image_page(GFP_ATOMIC, PG_ANY);
|
if (!buffer)
|
return -ENOMEM;
|
}
|
if (!handle->cur) {
|
int error;
|
|
error = init_header((struct swsusp_info *)buffer);
|
if (error)
|
return error;
|
handle->buffer = buffer;
|
memory_bm_position_reset(&orig_bm);
|
memory_bm_position_reset(©_bm);
|
} else if (handle->cur <= nr_meta_pages) {
|
clear_page(buffer);
|
pack_pfns(buffer, &orig_bm);
|
} else {
|
struct page *page;
|
|
page = pfn_to_page(memory_bm_next_pfn(©_bm));
|
if (PageHighMem(page)) {
|
/*
|
* Highmem pages are copied to the buffer,
|
* because we can't return with a kmapped
|
* highmem page (we may not be called again).
|
*/
|
void *kaddr;
|
|
kaddr = kmap_atomic(page);
|
copy_page(buffer, kaddr);
|
kunmap_atomic(kaddr);
|
handle->buffer = buffer;
|
} else {
|
handle->buffer = page_address(page);
|
}
|
}
|
handle->cur++;
|
return PAGE_SIZE;
|
}
|
|
static void duplicate_memory_bitmap(struct memory_bitmap *dst,
|
struct memory_bitmap *src)
|
{
|
unsigned long pfn;
|
|
memory_bm_position_reset(src);
|
pfn = memory_bm_next_pfn(src);
|
while (pfn != BM_END_OF_MAP) {
|
memory_bm_set_bit(dst, pfn);
|
pfn = memory_bm_next_pfn(src);
|
}
|
}
|
|
/**
|
* mark_unsafe_pages - Mark pages that were used before hibernation.
|
*
|
* Mark the pages that cannot be used for storing the image during restoration,
|
* because they conflict with the pages that had been used before hibernation.
|
*/
|
static void mark_unsafe_pages(struct memory_bitmap *bm)
|
{
|
unsigned long pfn;
|
|
/* Clear the "free"/"unsafe" bit for all PFNs */
|
memory_bm_position_reset(free_pages_map);
|
pfn = memory_bm_next_pfn(free_pages_map);
|
while (pfn != BM_END_OF_MAP) {
|
memory_bm_clear_current(free_pages_map);
|
pfn = memory_bm_next_pfn(free_pages_map);
|
}
|
|
/* Mark pages that correspond to the "original" PFNs as "unsafe" */
|
duplicate_memory_bitmap(free_pages_map, bm);
|
|
allocated_unsafe_pages = 0;
|
}
|
|
static int check_header(struct swsusp_info *info)
|
{
|
char *reason;
|
|
reason = check_image_kernel(info);
|
if (!reason && info->num_physpages != get_num_physpages())
|
reason = "memory size";
|
if (reason) {
|
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.
|
*
|
* For each element of the array pointed to by @buf (1 page at a time), set the
|
* corresponding bit in @bm.
|
*/
|
static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
|
{
|
int j;
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
|
if (unlikely(buf[j] == BM_END_OF_MAP))
|
break;
|
|
/* Extract and buffer page key for data page (s390 only). */
|
page_key_memorize(buf + j);
|
|
if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
|
memory_bm_set_bit(bm, buf[j]);
|
else
|
return -EFAULT;
|
}
|
|
return 0;
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
/*
|
* struct highmem_pbe is used for creating the list of highmem pages that
|
* should be restored atomically during the resume from disk, because the page
|
* frames they have occupied before the suspend are in use.
|
*/
|
struct highmem_pbe {
|
struct page *copy_page; /* data is here now */
|
struct page *orig_page; /* data was here before the suspend */
|
struct highmem_pbe *next;
|
};
|
|
/*
|
* List of highmem PBEs needed for restoring the highmem pages that were
|
* allocated before the suspend and included in the suspend image, but have
|
* also been allocated by the "resume" kernel, so their contents cannot be
|
* written directly to their "original" page frames.
|
*/
|
static struct highmem_pbe *highmem_pblist;
|
|
/**
|
* count_highmem_image_pages - Compute the number of highmem pages in the image.
|
* @bm: Memory bitmap.
|
*
|
* The bits in @bm that correspond to image pages are assumed to be set.
|
*/
|
static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
|
{
|
unsigned long pfn;
|
unsigned int cnt = 0;
|
|
memory_bm_position_reset(bm);
|
pfn = memory_bm_next_pfn(bm);
|
while (pfn != BM_END_OF_MAP) {
|
if (PageHighMem(pfn_to_page(pfn)))
|
cnt++;
|
|
pfn = memory_bm_next_pfn(bm);
|
}
|
return cnt;
|
}
|
|
static unsigned int safe_highmem_pages;
|
|
static struct memory_bitmap *safe_highmem_bm;
|
|
/**
|
* prepare_highmem_image - Allocate memory for loading highmem data from image.
|
* @bm: Pointer to an uninitialized memory bitmap structure.
|
* @nr_highmem_p: Pointer to the number of highmem image pages.
|
*
|
* Try to allocate as many highmem pages as there are highmem image pages
|
* (@nr_highmem_p points to the variable containing the number of highmem image
|
* pages). The pages that are "safe" (ie. will not be overwritten when the
|
* hibernation image is restored entirely) have the corresponding bits set in
|
* @bm (it must be unitialized).
|
*
|
* NOTE: This function should not be called if there are no highmem image pages.
|
*/
|
static int prepare_highmem_image(struct memory_bitmap *bm,
|
unsigned int *nr_highmem_p)
|
{
|
unsigned int to_alloc;
|
|
if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
|
return -ENOMEM;
|
|
if (get_highmem_buffer(PG_SAFE))
|
return -ENOMEM;
|
|
to_alloc = count_free_highmem_pages();
|
if (to_alloc > *nr_highmem_p)
|
to_alloc = *nr_highmem_p;
|
else
|
*nr_highmem_p = to_alloc;
|
|
safe_highmem_pages = 0;
|
while (to_alloc-- > 0) {
|
struct page *page;
|
|
page = alloc_page(__GFP_HIGHMEM);
|
if (!swsusp_page_is_free(page)) {
|
/* The page is "safe", set its bit the bitmap */
|
memory_bm_set_bit(bm, page_to_pfn(page));
|
safe_highmem_pages++;
|
}
|
/* Mark the page as allocated */
|
swsusp_set_page_forbidden(page);
|
swsusp_set_page_free(page);
|
}
|
memory_bm_position_reset(bm);
|
safe_highmem_bm = bm;
|
return 0;
|
}
|
|
static struct page *last_highmem_page;
|
|
/**
|
* get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
|
*
|
* For a given highmem image page get a buffer that suspend_write_next() should
|
* return to its caller to write to.
|
*
|
* If the page is to be saved to its "original" page frame or a copy of
|
* the page is to be made in the highmem, @buffer is returned. Otherwise,
|
* the copy of the page is to be made in normal memory, so the address of
|
* the copy is returned.
|
*
|
* If @buffer is returned, the caller of suspend_write_next() will write
|
* the page's contents to @buffer, so they will have to be copied to the
|
* right location on the next call to suspend_write_next() and it is done
|
* with the help of copy_last_highmem_page(). For this purpose, if
|
* @buffer is returned, @last_highmem_page is set to the page to which
|
* the data will have to be copied from @buffer.
|
*/
|
static void *get_highmem_page_buffer(struct page *page,
|
struct chain_allocator *ca)
|
{
|
struct highmem_pbe *pbe;
|
void *kaddr;
|
|
if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
|
/*
|
* We have allocated the "original" page frame and we can
|
* use it directly to store the loaded page.
|
*/
|
last_highmem_page = page;
|
return buffer;
|
}
|
/*
|
* The "original" page frame has not been allocated and we have to
|
* use a "safe" page frame to store the loaded page.
|
*/
|
pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
|
if (!pbe) {
|
swsusp_free();
|
return ERR_PTR(-ENOMEM);
|
}
|
pbe->orig_page = page;
|
if (safe_highmem_pages > 0) {
|
struct page *tmp;
|
|
/* Copy of the page will be stored in high memory */
|
kaddr = buffer;
|
tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
|
safe_highmem_pages--;
|
last_highmem_page = tmp;
|
pbe->copy_page = tmp;
|
} else {
|
/* Copy of the page will be stored in normal memory */
|
kaddr = safe_pages_list;
|
safe_pages_list = safe_pages_list->next;
|
pbe->copy_page = virt_to_page(kaddr);
|
}
|
pbe->next = highmem_pblist;
|
highmem_pblist = pbe;
|
return kaddr;
|
}
|
|
/**
|
* copy_last_highmem_page - Copy most the most recent highmem image page.
|
*
|
* Copy the contents of a highmem image from @buffer, where the caller of
|
* snapshot_write_next() has stored them, to the right location represented by
|
* @last_highmem_page .
|
*/
|
static void copy_last_highmem_page(void)
|
{
|
if (last_highmem_page) {
|
void *dst;
|
|
dst = kmap_atomic(last_highmem_page);
|
copy_page(dst, buffer);
|
kunmap_atomic(dst);
|
last_highmem_page = NULL;
|
}
|
}
|
|
static inline int last_highmem_page_copied(void)
|
{
|
return !last_highmem_page;
|
}
|
|
static inline void free_highmem_data(void)
|
{
|
if (safe_highmem_bm)
|
memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
|
|
if (buffer)
|
free_image_page(buffer, PG_UNSAFE_CLEAR);
|
}
|
#else
|
static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
|
|
static inline int prepare_highmem_image(struct memory_bitmap *bm,
|
unsigned int *nr_highmem_p) { return 0; }
|
|
static inline void *get_highmem_page_buffer(struct page *page,
|
struct chain_allocator *ca)
|
{
|
return ERR_PTR(-EINVAL);
|
}
|
|
static inline void copy_last_highmem_page(void) {}
|
static inline int last_highmem_page_copied(void) { return 1; }
|
static inline void free_highmem_data(void) {}
|
#endif /* CONFIG_HIGHMEM */
|
|
#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
|
|
/**
|
* prepare_image - Make room for loading hibernation image.
|
* @new_bm: Unitialized memory bitmap structure.
|
* @bm: Memory bitmap with unsafe pages marked.
|
*
|
* Use @bm to mark the pages that will be overwritten in the process of
|
* restoring the system memory state from the suspend image ("unsafe" pages)
|
* and allocate memory for the image.
|
*
|
* The idea is to allocate a new memory bitmap first and then allocate
|
* as many pages as needed for image data, but without specifying what those
|
* pages will be used for just yet. Instead, we mark them all as allocated and
|
* create a lists of "safe" pages to be used later. On systems with high
|
* memory a list of "safe" highmem pages is created too.
|
*/
|
static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
|
{
|
unsigned int nr_pages, nr_highmem;
|
struct linked_page *lp;
|
int error;
|
|
/* If there is no highmem, the buffer will not be necessary */
|
free_image_page(buffer, PG_UNSAFE_CLEAR);
|
buffer = NULL;
|
|
nr_highmem = count_highmem_image_pages(bm);
|
mark_unsafe_pages(bm);
|
|
error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
|
if (error)
|
goto Free;
|
|
duplicate_memory_bitmap(new_bm, bm);
|
memory_bm_free(bm, PG_UNSAFE_KEEP);
|
if (nr_highmem > 0) {
|
error = prepare_highmem_image(bm, &nr_highmem);
|
if (error)
|
goto Free;
|
}
|
/*
|
* Reserve some safe pages for potential later use.
|
*
|
* NOTE: This way we make sure there will be enough safe pages for the
|
* chain_alloc() in get_buffer(). It is a bit wasteful, but
|
* nr_copy_pages cannot be greater than 50% of the memory anyway.
|
*
|
* nr_copy_pages cannot be less than allocated_unsafe_pages too.
|
*/
|
nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
|
nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
|
while (nr_pages > 0) {
|
lp = get_image_page(GFP_ATOMIC, PG_SAFE);
|
if (!lp) {
|
error = -ENOMEM;
|
goto Free;
|
}
|
lp->next = safe_pages_list;
|
safe_pages_list = lp;
|
nr_pages--;
|
}
|
/* Preallocate memory for the image */
|
nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
|
while (nr_pages > 0) {
|
lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
|
if (!lp) {
|
error = -ENOMEM;
|
goto Free;
|
}
|
if (!swsusp_page_is_free(virt_to_page(lp))) {
|
/* The page is "safe", add it to the list */
|
lp->next = safe_pages_list;
|
safe_pages_list = lp;
|
}
|
/* Mark the page as allocated */
|
swsusp_set_page_forbidden(virt_to_page(lp));
|
swsusp_set_page_free(virt_to_page(lp));
|
nr_pages--;
|
}
|
return 0;
|
|
Free:
|
swsusp_free();
|
return error;
|
}
|
|
/**
|
* get_buffer - Get the address to store the next image data page.
|
*
|
* Get the address that snapshot_write_next() should return to its caller to
|
* write to.
|
*/
|
static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
|
{
|
struct pbe *pbe;
|
struct page *page;
|
unsigned long pfn = memory_bm_next_pfn(bm);
|
|
if (pfn == BM_END_OF_MAP)
|
return ERR_PTR(-EFAULT);
|
|
page = pfn_to_page(pfn);
|
if (PageHighMem(page))
|
return get_highmem_page_buffer(page, ca);
|
|
if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
|
/*
|
* We have allocated the "original" page frame and we can
|
* use it directly to store the loaded page.
|
*/
|
return page_address(page);
|
|
/*
|
* The "original" page frame has not been allocated and we have to
|
* use a "safe" page frame to store the loaded page.
|
*/
|
pbe = chain_alloc(ca, sizeof(struct pbe));
|
if (!pbe) {
|
swsusp_free();
|
return ERR_PTR(-ENOMEM);
|
}
|
pbe->orig_address = page_address(page);
|
pbe->address = safe_pages_list;
|
safe_pages_list = safe_pages_list->next;
|
pbe->next = restore_pblist;
|
restore_pblist = pbe;
|
return pbe->address;
|
}
|
|
/**
|
* snapshot_write_next - Get the address to store the next image page.
|
* @handle: Snapshot handle structure to guide the writing.
|
*
|
* On the first call, @handle should point to a zeroed snapshot_handle
|
* structure. The structure gets populated then and a pointer to it should be
|
* passed to this function every next time.
|
*
|
* On success, the function returns a positive number. Then, the caller
|
* is allowed to write up to the returned number of bytes to the memory
|
* location computed by the data_of() macro.
|
*
|
* The function returns 0 to indicate the "end of file" condition. Negative
|
* numbers are returned on errors, in which cases the structure pointed to by
|
* @handle is not updated and should not be used any more.
|
*/
|
int snapshot_write_next(struct snapshot_handle *handle)
|
{
|
static struct chain_allocator ca;
|
int error = 0;
|
|
/* Check if we have already loaded the entire image */
|
if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
|
return 0;
|
|
handle->sync_read = 1;
|
|
if (!handle->cur) {
|
if (!buffer)
|
/* This makes the buffer be freed by swsusp_free() */
|
buffer = get_image_page(GFP_ATOMIC, PG_ANY);
|
|
if (!buffer)
|
return -ENOMEM;
|
|
handle->buffer = buffer;
|
} else if (handle->cur == 1) {
|
error = load_header(buffer);
|
if (error)
|
return error;
|
|
safe_pages_list = NULL;
|
|
error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
|
if (error)
|
return error;
|
|
/* Allocate buffer for page keys. */
|
error = page_key_alloc(nr_copy_pages);
|
if (error)
|
return error;
|
|
hibernate_restore_protection_begin();
|
} else if (handle->cur <= nr_meta_pages + 1) {
|
error = unpack_orig_pfns(buffer, ©_bm);
|
if (error)
|
return error;
|
|
if (handle->cur == nr_meta_pages + 1) {
|
error = prepare_image(&orig_bm, ©_bm);
|
if (error)
|
return error;
|
|
chain_init(&ca, GFP_ATOMIC, PG_SAFE);
|
memory_bm_position_reset(&orig_bm);
|
restore_pblist = NULL;
|
handle->buffer = get_buffer(&orig_bm, &ca);
|
handle->sync_read = 0;
|
if (IS_ERR(handle->buffer))
|
return PTR_ERR(handle->buffer);
|
}
|
} else {
|
copy_last_highmem_page();
|
/* Restore page key for data page (s390 only). */
|
page_key_write(handle->buffer);
|
hibernate_restore_protect_page(handle->buffer);
|
handle->buffer = get_buffer(&orig_bm, &ca);
|
if (IS_ERR(handle->buffer))
|
return PTR_ERR(handle->buffer);
|
if (handle->buffer != buffer)
|
handle->sync_read = 0;
|
}
|
handle->cur++;
|
return PAGE_SIZE;
|
}
|
|
/**
|
* snapshot_write_finalize - Complete the loading of a hibernation image.
|
*
|
* Must be called after the last call to snapshot_write_next() in case the last
|
* page in the image happens to be a highmem page and its contents should be
|
* stored in highmem. Additionally, it recycles bitmap memory that's not
|
* necessary any more.
|
*/
|
void snapshot_write_finalize(struct snapshot_handle *handle)
|
{
|
copy_last_highmem_page();
|
/* Restore page key for data page (s390 only). */
|
page_key_write(handle->buffer);
|
page_key_free();
|
hibernate_restore_protect_page(handle->buffer);
|
/* Do that only if we have loaded the image entirely */
|
if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
|
memory_bm_recycle(&orig_bm);
|
free_highmem_data();
|
}
|
}
|
|
int snapshot_image_loaded(struct snapshot_handle *handle)
|
{
|
return !(!nr_copy_pages || !last_highmem_page_copied() ||
|
handle->cur <= nr_meta_pages + nr_copy_pages);
|
}
|
|
#ifdef CONFIG_HIGHMEM
|
/* Assumes that @buf is ready and points to a "safe" page */
|
static inline void swap_two_pages_data(struct page *p1, struct page *p2,
|
void *buf)
|
{
|
void *kaddr1, *kaddr2;
|
|
kaddr1 = kmap_atomic(p1);
|
kaddr2 = kmap_atomic(p2);
|
copy_page(buf, kaddr1);
|
copy_page(kaddr1, kaddr2);
|
copy_page(kaddr2, buf);
|
kunmap_atomic(kaddr2);
|
kunmap_atomic(kaddr1);
|
}
|
|
/**
|
* restore_highmem - Put highmem image pages into their original locations.
|
*
|
* For each highmem page that was in use before hibernation and is included in
|
* the image, and also has been allocated by the "restore" kernel, swap its
|
* current contents with the previous (ie. "before hibernation") ones.
|
*
|
* If the restore eventually fails, we can call this function once again and
|
* restore the highmem state as seen by the restore kernel.
|
*/
|
int restore_highmem(void)
|
{
|
struct highmem_pbe *pbe = highmem_pblist;
|
void *buf;
|
|
if (!pbe)
|
return 0;
|
|
buf = get_image_page(GFP_ATOMIC, PG_SAFE);
|
if (!buf)
|
return -ENOMEM;
|
|
while (pbe) {
|
swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
|
pbe = pbe->next;
|
}
|
free_image_page(buf, PG_UNSAFE_CLEAR);
|
return 0;
|
}
|
#endif /* CONFIG_HIGHMEM */
|
