1041 lines
26 KiB
C
1041 lines
26 KiB
C
/*
|
|
* linux/kernel/power/swsusp.c
|
|
*
|
|
* This file provides code to write suspend image to swap and read it back.
|
|
*
|
|
* Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
|
|
* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
|
|
*
|
|
* This file is released under the GPLv2.
|
|
*
|
|
* I'd like to thank the following people for their work:
|
|
*
|
|
* Pavel Machek <pavel@ucw.cz>:
|
|
* Modifications, defectiveness pointing, being with me at the very beginning,
|
|
* suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
|
|
*
|
|
* Steve Doddi <dirk@loth.demon.co.uk>:
|
|
* Support the possibility of hardware state restoring.
|
|
*
|
|
* Raph <grey.havens@earthling.net>:
|
|
* Support for preserving states of network devices and virtual console
|
|
* (including X and svgatextmode)
|
|
*
|
|
* Kurt Garloff <garloff@suse.de>:
|
|
* Straightened the critical function in order to prevent compilers from
|
|
* playing tricks with local variables.
|
|
*
|
|
* Andreas Mohr <a.mohr@mailto.de>
|
|
*
|
|
* Alex Badea <vampire@go.ro>:
|
|
* Fixed runaway init
|
|
*
|
|
* Rafael J. Wysocki <rjw@sisk.pl>
|
|
* Added the swap map data structure and reworked the handling of swap
|
|
*
|
|
* More state savers are welcome. Especially for the scsi layer...
|
|
*
|
|
* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/file.h>
|
|
#include <linux/utsname.h>
|
|
#include <linux/version.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/genhd.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/major.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/pm.h>
|
|
#include <linux/device.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/swapops.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/bio.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"
|
|
|
|
/*
|
|
* Preferred image size in bytes (tunable via /sys/power/image_size).
|
|
* When it is set to N, swsusp will do its best to ensure the image
|
|
* size will not exceed N bytes, but if that is impossible, it will
|
|
* try to create the smallest image possible.
|
|
*/
|
|
unsigned long image_size = 500 * 1024 * 1024;
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
unsigned int count_highmem_pages(void);
|
|
int save_highmem(void);
|
|
int restore_highmem(void);
|
|
#else
|
|
static int save_highmem(void) { return 0; }
|
|
static int restore_highmem(void) { return 0; }
|
|
static unsigned int count_highmem_pages(void) { return 0; }
|
|
#endif
|
|
|
|
extern char resume_file[];
|
|
|
|
#define SWSUSP_SIG "S1SUSPEND"
|
|
|
|
static struct swsusp_header {
|
|
char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
|
|
swp_entry_t image;
|
|
char orig_sig[10];
|
|
char sig[10];
|
|
} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
|
|
|
|
static struct swsusp_info swsusp_info;
|
|
|
|
/*
|
|
* Saving part...
|
|
*/
|
|
|
|
static unsigned short root_swap = 0xffff;
|
|
|
|
static int mark_swapfiles(swp_entry_t start)
|
|
{
|
|
int error;
|
|
|
|
rw_swap_page_sync(READ,
|
|
swp_entry(root_swap, 0),
|
|
virt_to_page((unsigned long)&swsusp_header));
|
|
if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
|
|
!memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
|
|
memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
|
|
memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
|
|
swsusp_header.image = start;
|
|
error = rw_swap_page_sync(WRITE,
|
|
swp_entry(root_swap, 0),
|
|
virt_to_page((unsigned long)
|
|
&swsusp_header));
|
|
} else {
|
|
pr_debug("swsusp: Partition is not swap space.\n");
|
|
error = -ENODEV;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Check whether the swap device is the specified resume
|
|
* device, irrespective of whether they are specified by
|
|
* identical names.
|
|
*
|
|
* (Thus, device inode aliasing is allowed. You can say /dev/hda4
|
|
* instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
|
|
* and they'll be considered the same device. This is *necessary* for
|
|
* devfs, since the resume code can only recognize the form /dev/hda4,
|
|
* but the suspend code would see the long name.)
|
|
*/
|
|
static inline int is_resume_device(const struct swap_info_struct *swap_info)
|
|
{
|
|
struct file *file = swap_info->swap_file;
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
|
|
return S_ISBLK(inode->i_mode) &&
|
|
swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
|
|
}
|
|
|
|
static int swsusp_swap_check(void) /* This is called before saving image */
|
|
{
|
|
int i;
|
|
|
|
if (!swsusp_resume_device)
|
|
return -ENODEV;
|
|
spin_lock(&swap_lock);
|
|
for (i = 0; i < MAX_SWAPFILES; i++) {
|
|
if (!(swap_info[i].flags & SWP_WRITEOK))
|
|
continue;
|
|
if (is_resume_device(swap_info + i)) {
|
|
spin_unlock(&swap_lock);
|
|
root_swap = i;
|
|
return 0;
|
|
}
|
|
}
|
|
spin_unlock(&swap_lock);
|
|
return -ENODEV;
|
|
}
|
|
|
|
/**
|
|
* write_page - Write one page to a fresh swap location.
|
|
* @addr: Address we're writing.
|
|
* @loc: Place to store the entry we used.
|
|
*
|
|
* Allocate a new swap entry and 'sync' it. Note we discard -EIO
|
|
* errors. That is an artifact left over from swsusp. It did not
|
|
* check the return of rw_swap_page_sync() at all, since most pages
|
|
* written back to swap would return -EIO.
|
|
* This is a partial improvement, since we will at least return other
|
|
* errors, though we need to eventually fix the damn code.
|
|
*/
|
|
static int write_page(unsigned long addr, swp_entry_t *loc)
|
|
{
|
|
swp_entry_t entry;
|
|
int error = -ENOSPC;
|
|
|
|
entry = get_swap_page_of_type(root_swap);
|
|
if (swp_offset(entry)) {
|
|
error = rw_swap_page_sync(WRITE, entry, virt_to_page(addr));
|
|
if (!error || error == -EIO)
|
|
*loc = entry;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* Swap map-handling functions
|
|
*
|
|
* The swap map is a data structure used for keeping track of each page
|
|
* written to the swap. It consists of many swap_map_page structures
|
|
* that contain each an array of MAP_PAGE_SIZE swap entries.
|
|
* These structures are linked together with the help of either the
|
|
* .next (in memory) or the .next_swap (in swap) member.
|
|
*
|
|
* The swap map is created during suspend. At that time we need to keep
|
|
* it in memory, because we have to free all of the allocated swap
|
|
* entries if an error occurs. The memory needed is preallocated
|
|
* so that we know in advance if there's enough of it.
|
|
*
|
|
* The first swap_map_page structure is filled with the swap entries that
|
|
* correspond to the first MAP_PAGE_SIZE data pages written to swap and
|
|
* so on. After the all of the data pages have been written, the order
|
|
* of the swap_map_page structures in the map is reversed so that they
|
|
* can be read from swap in the original order. This causes the data
|
|
* pages to be loaded in exactly the same order in which they have been
|
|
* saved.
|
|
*
|
|
* During resume we only need to use one swap_map_page structure
|
|
* at a time, which means that we only need to use two memory pages for
|
|
* reading the image - one for reading the swap_map_page structures
|
|
* and the second for reading the data pages from swap.
|
|
*/
|
|
|
|
#define MAP_PAGE_SIZE ((PAGE_SIZE - sizeof(swp_entry_t) - sizeof(void *)) \
|
|
/ sizeof(swp_entry_t))
|
|
|
|
struct swap_map_page {
|
|
swp_entry_t entries[MAP_PAGE_SIZE];
|
|
swp_entry_t next_swap;
|
|
struct swap_map_page *next;
|
|
};
|
|
|
|
static inline void free_swap_map(struct swap_map_page *swap_map)
|
|
{
|
|
struct swap_map_page *swp;
|
|
|
|
while (swap_map) {
|
|
swp = swap_map->next;
|
|
free_page((unsigned long)swap_map);
|
|
swap_map = swp;
|
|
}
|
|
}
|
|
|
|
static struct swap_map_page *alloc_swap_map(unsigned int nr_pages)
|
|
{
|
|
struct swap_map_page *swap_map, *swp;
|
|
unsigned n = 0;
|
|
|
|
if (!nr_pages)
|
|
return NULL;
|
|
|
|
pr_debug("alloc_swap_map(): nr_pages = %d\n", nr_pages);
|
|
swap_map = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
|
|
swp = swap_map;
|
|
for (n = MAP_PAGE_SIZE; n < nr_pages; n += MAP_PAGE_SIZE) {
|
|
swp->next = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
|
|
swp = swp->next;
|
|
if (!swp) {
|
|
free_swap_map(swap_map);
|
|
return NULL;
|
|
}
|
|
}
|
|
return swap_map;
|
|
}
|
|
|
|
/**
|
|
* reverse_swap_map - reverse the order of pages in the swap map
|
|
* @swap_map
|
|
*/
|
|
|
|
static inline struct swap_map_page *reverse_swap_map(struct swap_map_page *swap_map)
|
|
{
|
|
struct swap_map_page *prev, *next;
|
|
|
|
prev = NULL;
|
|
while (swap_map) {
|
|
next = swap_map->next;
|
|
swap_map->next = prev;
|
|
prev = swap_map;
|
|
swap_map = next;
|
|
}
|
|
return prev;
|
|
}
|
|
|
|
/**
|
|
* free_swap_map_entries - free the swap entries allocated to store
|
|
* the swap map @swap_map (this is only called in case of an error)
|
|
*/
|
|
static inline void free_swap_map_entries(struct swap_map_page *swap_map)
|
|
{
|
|
while (swap_map) {
|
|
if (swap_map->next_swap.val)
|
|
swap_free(swap_map->next_swap);
|
|
swap_map = swap_map->next;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* save_swap_map - save the swap map used for tracing the data pages
|
|
* stored in the swap
|
|
*/
|
|
|
|
static int save_swap_map(struct swap_map_page *swap_map, swp_entry_t *start)
|
|
{
|
|
swp_entry_t entry = (swp_entry_t){0};
|
|
int error;
|
|
|
|
while (swap_map) {
|
|
swap_map->next_swap = entry;
|
|
if ((error = write_page((unsigned long)swap_map, &entry)))
|
|
return error;
|
|
swap_map = swap_map->next;
|
|
}
|
|
*start = entry;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* free_image_entries - free the swap entries allocated to store
|
|
* the image data pages (this is only called in case of an error)
|
|
*/
|
|
|
|
static inline void free_image_entries(struct swap_map_page *swp)
|
|
{
|
|
unsigned k;
|
|
|
|
while (swp) {
|
|
for (k = 0; k < MAP_PAGE_SIZE; k++)
|
|
if (swp->entries[k].val)
|
|
swap_free(swp->entries[k]);
|
|
swp = swp->next;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The swap_map_handle structure is used for handling the swap map in
|
|
* a file-alike way
|
|
*/
|
|
|
|
struct swap_map_handle {
|
|
struct swap_map_page *cur;
|
|
unsigned int k;
|
|
};
|
|
|
|
static inline void init_swap_map_handle(struct swap_map_handle *handle,
|
|
struct swap_map_page *map)
|
|
{
|
|
handle->cur = map;
|
|
handle->k = 0;
|
|
}
|
|
|
|
static inline int swap_map_write_page(struct swap_map_handle *handle,
|
|
unsigned long addr)
|
|
{
|
|
int error;
|
|
|
|
error = write_page(addr, handle->cur->entries + handle->k);
|
|
if (error)
|
|
return error;
|
|
if (++handle->k >= MAP_PAGE_SIZE) {
|
|
handle->cur = handle->cur->next;
|
|
handle->k = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* save_image_data - save the data pages pointed to by the PBEs
|
|
* from the list @pblist using the swap map handle @handle
|
|
* (assume there are @nr_pages data pages to save)
|
|
*/
|
|
|
|
static int save_image_data(struct pbe *pblist,
|
|
struct swap_map_handle *handle,
|
|
unsigned int nr_pages)
|
|
{
|
|
unsigned int m;
|
|
struct pbe *p;
|
|
int error = 0;
|
|
|
|
printk("Saving image data pages (%u pages) ... ", nr_pages);
|
|
m = nr_pages / 100;
|
|
if (!m)
|
|
m = 1;
|
|
nr_pages = 0;
|
|
for_each_pbe (p, pblist) {
|
|
error = swap_map_write_page(handle, p->address);
|
|
if (error)
|
|
break;
|
|
if (!(nr_pages % m))
|
|
printk("\b\b\b\b%3d%%", nr_pages / m);
|
|
nr_pages++;
|
|
}
|
|
if (!error)
|
|
printk("\b\b\b\bdone\n");
|
|
return error;
|
|
}
|
|
|
|
static void dump_info(void)
|
|
{
|
|
pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
|
|
pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
|
|
pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
|
|
pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
|
|
pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
|
|
pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
|
|
pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
|
|
pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
|
|
pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
|
|
pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
|
|
pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
|
|
}
|
|
|
|
static void init_header(unsigned int nr_pages)
|
|
{
|
|
memset(&swsusp_info, 0, sizeof(swsusp_info));
|
|
swsusp_info.version_code = LINUX_VERSION_CODE;
|
|
swsusp_info.num_physpages = num_physpages;
|
|
memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
|
|
|
|
swsusp_info.cpus = num_online_cpus();
|
|
swsusp_info.image_pages = nr_pages;
|
|
swsusp_info.pages = nr_pages +
|
|
((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
|
|
}
|
|
|
|
/**
|
|
* pack_orig_addresses - the .orig_address fields of the PBEs from the
|
|
* list starting at @pbe are stored in the array @buf[] (1 page)
|
|
*/
|
|
|
|
static inline struct pbe *pack_orig_addresses(unsigned long *buf,
|
|
struct pbe *pbe)
|
|
{
|
|
int j;
|
|
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
|
|
buf[j] = pbe->orig_address;
|
|
pbe = pbe->next;
|
|
}
|
|
if (!pbe)
|
|
for (; j < PAGE_SIZE / sizeof(long); j++)
|
|
buf[j] = 0;
|
|
return pbe;
|
|
}
|
|
|
|
/**
|
|
* save_image_metadata - save the .orig_address fields of the PBEs
|
|
* from the list @pblist using the swap map handle @handle
|
|
*/
|
|
|
|
static int save_image_metadata(struct pbe *pblist,
|
|
struct swap_map_handle *handle)
|
|
{
|
|
unsigned long *buf;
|
|
unsigned int n = 0;
|
|
struct pbe *p;
|
|
int error = 0;
|
|
|
|
printk("Saving image metadata ... ");
|
|
buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
p = pblist;
|
|
while (p) {
|
|
p = pack_orig_addresses(buf, p);
|
|
error = swap_map_write_page(handle, (unsigned long)buf);
|
|
if (error)
|
|
break;
|
|
n++;
|
|
}
|
|
free_page((unsigned long)buf);
|
|
if (!error)
|
|
printk("done (%u pages saved)\n", n);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* enough_swap - Make sure we have enough swap to save the image.
|
|
*
|
|
* Returns TRUE or FALSE after checking the total amount of swap
|
|
* space avaiable from the resume partition.
|
|
*/
|
|
|
|
static int enough_swap(unsigned int nr_pages)
|
|
{
|
|
unsigned int free_swap = swap_info[root_swap].pages -
|
|
swap_info[root_swap].inuse_pages;
|
|
|
|
pr_debug("swsusp: free swap pages: %u\n", free_swap);
|
|
return free_swap > (nr_pages + PAGES_FOR_IO +
|
|
(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
|
|
}
|
|
|
|
/**
|
|
* swsusp_write - Write entire image and metadata.
|
|
*
|
|
* It is important _NOT_ to umount filesystems at this point. We want
|
|
* them synced (in case something goes wrong) but we DO not want to mark
|
|
* filesystem clean: it is not. (And it does not matter, if we resume
|
|
* correctly, we'll mark system clean, anyway.)
|
|
*/
|
|
|
|
int swsusp_write(struct pbe *pblist, unsigned int nr_pages)
|
|
{
|
|
struct swap_map_page *swap_map;
|
|
struct swap_map_handle handle;
|
|
swp_entry_t start;
|
|
int error;
|
|
|
|
if ((error = swsusp_swap_check())) {
|
|
printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
|
|
return error;
|
|
}
|
|
if (!enough_swap(nr_pages)) {
|
|
printk(KERN_ERR "swsusp: Not enough free swap\n");
|
|
return -ENOSPC;
|
|
}
|
|
|
|
init_header(nr_pages);
|
|
swap_map = alloc_swap_map(swsusp_info.pages);
|
|
if (!swap_map)
|
|
return -ENOMEM;
|
|
init_swap_map_handle(&handle, swap_map);
|
|
|
|
error = swap_map_write_page(&handle, (unsigned long)&swsusp_info);
|
|
if (!error)
|
|
error = save_image_metadata(pblist, &handle);
|
|
if (!error)
|
|
error = save_image_data(pblist, &handle, nr_pages);
|
|
if (error)
|
|
goto Free_image_entries;
|
|
|
|
swap_map = reverse_swap_map(swap_map);
|
|
error = save_swap_map(swap_map, &start);
|
|
if (error)
|
|
goto Free_map_entries;
|
|
|
|
dump_info();
|
|
printk( "S" );
|
|
error = mark_swapfiles(start);
|
|
printk( "|\n" );
|
|
if (error)
|
|
goto Free_map_entries;
|
|
|
|
Free_swap_map:
|
|
free_swap_map(swap_map);
|
|
return error;
|
|
|
|
Free_map_entries:
|
|
free_swap_map_entries(swap_map);
|
|
Free_image_entries:
|
|
free_image_entries(swap_map);
|
|
goto Free_swap_map;
|
|
}
|
|
|
|
/**
|
|
* swsusp_shrink_memory - Try to free as much memory as needed
|
|
*
|
|
* ... but do not OOM-kill anyone
|
|
*
|
|
* Notice: all userland should be stopped before it is called, or
|
|
* livelock is possible.
|
|
*/
|
|
|
|
#define SHRINK_BITE 10000
|
|
|
|
int swsusp_shrink_memory(void)
|
|
{
|
|
long size, tmp;
|
|
struct zone *zone;
|
|
unsigned long pages = 0;
|
|
unsigned int i = 0;
|
|
char *p = "-\\|/";
|
|
|
|
printk("Shrinking memory... ");
|
|
do {
|
|
size = 2 * count_highmem_pages();
|
|
size += size / 50 + count_data_pages();
|
|
size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE +
|
|
PAGES_FOR_IO;
|
|
tmp = size;
|
|
for_each_zone (zone)
|
|
if (!is_highmem(zone))
|
|
tmp -= zone->free_pages;
|
|
if (tmp > 0) {
|
|
tmp = shrink_all_memory(SHRINK_BITE);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
pages += tmp;
|
|
} else if (size > image_size / PAGE_SIZE) {
|
|
tmp = shrink_all_memory(SHRINK_BITE);
|
|
pages += tmp;
|
|
}
|
|
printk("\b%c", p[i++%4]);
|
|
} while (tmp > 0);
|
|
printk("\bdone (%lu pages freed)\n", pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int swsusp_suspend(void)
|
|
{
|
|
int error;
|
|
|
|
if ((error = arch_prepare_suspend()))
|
|
return error;
|
|
local_irq_disable();
|
|
/* At this point, device_suspend() has been called, but *not*
|
|
* device_power_down(). We *must* device_power_down() now.
|
|
* Otherwise, drivers for some devices (e.g. interrupt controllers)
|
|
* become desynchronized with the actual state of the hardware
|
|
* at resume time, and evil weirdness ensues.
|
|
*/
|
|
if ((error = device_power_down(PMSG_FREEZE))) {
|
|
printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
|
|
goto Enable_irqs;
|
|
}
|
|
|
|
if ((error = save_highmem())) {
|
|
printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");
|
|
goto Restore_highmem;
|
|
}
|
|
|
|
save_processor_state();
|
|
if ((error = swsusp_arch_suspend()))
|
|
printk(KERN_ERR "Error %d suspending\n", error);
|
|
/* Restore control flow magically appears here */
|
|
restore_processor_state();
|
|
Restore_highmem:
|
|
restore_highmem();
|
|
device_power_up();
|
|
Enable_irqs:
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
int swsusp_resume(void)
|
|
{
|
|
int error;
|
|
local_irq_disable();
|
|
if (device_power_down(PMSG_FREEZE))
|
|
printk(KERN_ERR "Some devices failed to power down, very bad\n");
|
|
/* We'll ignore saved state, but this gets preempt count (etc) right */
|
|
save_processor_state();
|
|
error = swsusp_arch_resume();
|
|
/* Code below is only ever reached in case of failure. Otherwise
|
|
* execution continues at place where swsusp_arch_suspend was called
|
|
*/
|
|
BUG_ON(!error);
|
|
/* The only reason why swsusp_arch_resume() can fail is memory being
|
|
* very tight, so we have to free it as soon as we can to avoid
|
|
* subsequent failures
|
|
*/
|
|
swsusp_free();
|
|
restore_processor_state();
|
|
restore_highmem();
|
|
touch_softlockup_watchdog();
|
|
device_power_up();
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* 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 void mark_unsafe_pages(struct pbe *pblist)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long zone_pfn;
|
|
struct pbe *p;
|
|
|
|
if (!pblist) /* a sanity check */
|
|
return;
|
|
|
|
/* Clear page flags */
|
|
for_each_zone (zone) {
|
|
for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
|
|
if (pfn_valid(zone_pfn + zone->zone_start_pfn))
|
|
ClearPageNosaveFree(pfn_to_page(zone_pfn +
|
|
zone->zone_start_pfn));
|
|
}
|
|
|
|
/* Mark orig addresses */
|
|
for_each_pbe (p, pblist)
|
|
SetPageNosaveFree(virt_to_page(p->orig_address));
|
|
|
|
}
|
|
|
|
static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
|
|
{
|
|
/* We assume both lists contain the same number of elements */
|
|
while (src) {
|
|
dst->orig_address = src->orig_address;
|
|
dst = dst->next;
|
|
src = src->next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Using bio to read from swap.
|
|
* This code requires a bit more work than just using buffer heads
|
|
* but, it is the recommended way for 2.5/2.6.
|
|
* The following are to signal the beginning and end of I/O. Bios
|
|
* finish asynchronously, while we want them to happen synchronously.
|
|
* A simple atomic_t, and a wait loop take care of this problem.
|
|
*/
|
|
|
|
static atomic_t io_done = ATOMIC_INIT(0);
|
|
|
|
static int end_io(struct bio *bio, unsigned int num, int err)
|
|
{
|
|
if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
|
|
panic("I/O error reading memory image");
|
|
atomic_set(&io_done, 0);
|
|
return 0;
|
|
}
|
|
|
|
static struct block_device *resume_bdev;
|
|
|
|
/**
|
|
* submit - submit BIO request.
|
|
* @rw: READ or WRITE.
|
|
* @off physical offset of page.
|
|
* @page: page we're reading or writing.
|
|
*
|
|
* Straight from the textbook - allocate and initialize the bio.
|
|
* If we're writing, make sure the page is marked as dirty.
|
|
* Then submit it and wait.
|
|
*/
|
|
|
|
static int submit(int rw, pgoff_t page_off, void *page)
|
|
{
|
|
int error = 0;
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(GFP_ATOMIC, 1);
|
|
if (!bio)
|
|
return -ENOMEM;
|
|
bio->bi_sector = page_off * (PAGE_SIZE >> 9);
|
|
bio->bi_bdev = resume_bdev;
|
|
bio->bi_end_io = end_io;
|
|
|
|
if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
|
|
printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
|
|
error = -EFAULT;
|
|
goto Done;
|
|
}
|
|
|
|
|
|
atomic_set(&io_done, 1);
|
|
submit_bio(rw | (1 << BIO_RW_SYNC), bio);
|
|
while (atomic_read(&io_done))
|
|
yield();
|
|
if (rw == READ)
|
|
bio_set_pages_dirty(bio);
|
|
Done:
|
|
bio_put(bio);
|
|
return error;
|
|
}
|
|
|
|
static int bio_read_page(pgoff_t page_off, void *page)
|
|
{
|
|
return submit(READ, page_off, page);
|
|
}
|
|
|
|
static int bio_write_page(pgoff_t page_off, void *page)
|
|
{
|
|
return submit(WRITE, page_off, page);
|
|
}
|
|
|
|
/**
|
|
* The following functions allow us to read data using a swap map
|
|
* in a file-alike way
|
|
*/
|
|
|
|
static inline void release_swap_map_reader(struct swap_map_handle *handle)
|
|
{
|
|
if (handle->cur)
|
|
free_page((unsigned long)handle->cur);
|
|
handle->cur = NULL;
|
|
}
|
|
|
|
static inline int get_swap_map_reader(struct swap_map_handle *handle,
|
|
swp_entry_t start)
|
|
{
|
|
int error;
|
|
|
|
if (!swp_offset(start))
|
|
return -EINVAL;
|
|
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
|
|
if (!handle->cur)
|
|
return -ENOMEM;
|
|
error = bio_read_page(swp_offset(start), handle->cur);
|
|
if (error) {
|
|
release_swap_map_reader(handle);
|
|
return error;
|
|
}
|
|
handle->k = 0;
|
|
return 0;
|
|
}
|
|
|
|
static inline int swap_map_read_page(struct swap_map_handle *handle, void *buf)
|
|
{
|
|
unsigned long offset;
|
|
int error;
|
|
|
|
if (!handle->cur)
|
|
return -EINVAL;
|
|
offset = swp_offset(handle->cur->entries[handle->k]);
|
|
if (!offset)
|
|
return -EINVAL;
|
|
error = bio_read_page(offset, buf);
|
|
if (error)
|
|
return error;
|
|
if (++handle->k >= MAP_PAGE_SIZE) {
|
|
handle->k = 0;
|
|
offset = swp_offset(handle->cur->next_swap);
|
|
if (!offset)
|
|
release_swap_map_reader(handle);
|
|
else
|
|
error = bio_read_page(offset, handle->cur);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int check_header(void)
|
|
{
|
|
char *reason = NULL;
|
|
|
|
dump_info();
|
|
if (swsusp_info.version_code != LINUX_VERSION_CODE)
|
|
reason = "kernel version";
|
|
if (swsusp_info.num_physpages != num_physpages)
|
|
reason = "memory size";
|
|
if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
|
|
reason = "system type";
|
|
if (strcmp(swsusp_info.uts.release,system_utsname.release))
|
|
reason = "kernel release";
|
|
if (strcmp(swsusp_info.uts.version,system_utsname.version))
|
|
reason = "version";
|
|
if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
|
|
reason = "machine";
|
|
if (reason) {
|
|
printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
|
|
return -EPERM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* load_image_data - load the image data using the swap map handle
|
|
* @handle and store them using the page backup list @pblist
|
|
* (assume there are @nr_pages pages to load)
|
|
*/
|
|
|
|
static int load_image_data(struct pbe *pblist,
|
|
struct swap_map_handle *handle,
|
|
unsigned int nr_pages)
|
|
{
|
|
int error;
|
|
unsigned int m;
|
|
struct pbe *p;
|
|
|
|
if (!pblist)
|
|
return -EINVAL;
|
|
printk("Loading image data pages (%u pages) ... ", nr_pages);
|
|
m = nr_pages / 100;
|
|
if (!m)
|
|
m = 1;
|
|
nr_pages = 0;
|
|
p = pblist;
|
|
while (p) {
|
|
error = swap_map_read_page(handle, (void *)p->address);
|
|
if (error)
|
|
break;
|
|
p = p->next;
|
|
if (!(nr_pages % m))
|
|
printk("\b\b\b\b%3d%%", nr_pages / m);
|
|
nr_pages++;
|
|
}
|
|
if (!error)
|
|
printk("\b\b\b\bdone\n");
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* unpack_orig_addresses - copy the elements of @buf[] (1 page) to
|
|
* the PBEs in the list starting at @pbe
|
|
*/
|
|
|
|
static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
|
|
struct pbe *pbe)
|
|
{
|
|
int j;
|
|
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
|
|
pbe->orig_address = buf[j];
|
|
pbe = pbe->next;
|
|
}
|
|
return pbe;
|
|
}
|
|
|
|
/**
|
|
* load_image_metadata - load the image metadata using the swap map
|
|
* handle @handle and put them into the PBEs in the list @pblist
|
|
*/
|
|
|
|
static int load_image_metadata(struct pbe *pblist, struct swap_map_handle *handle)
|
|
{
|
|
struct pbe *p;
|
|
unsigned long *buf;
|
|
unsigned int n = 0;
|
|
int error = 0;
|
|
|
|
printk("Loading image metadata ... ");
|
|
buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
p = pblist;
|
|
while (p) {
|
|
error = swap_map_read_page(handle, buf);
|
|
if (error)
|
|
break;
|
|
p = unpack_orig_addresses(buf, p);
|
|
n++;
|
|
}
|
|
free_page((unsigned long)buf);
|
|
if (!error)
|
|
printk("done (%u pages loaded)\n", n);
|
|
return error;
|
|
}
|
|
|
|
int swsusp_read(struct pbe **pblist_ptr)
|
|
{
|
|
int error;
|
|
struct pbe *p, *pblist;
|
|
struct swap_map_handle handle;
|
|
unsigned int nr_pages;
|
|
|
|
if (IS_ERR(resume_bdev)) {
|
|
pr_debug("swsusp: block device not initialised\n");
|
|
return PTR_ERR(resume_bdev);
|
|
}
|
|
|
|
error = get_swap_map_reader(&handle, swsusp_header.image);
|
|
if (!error)
|
|
error = swap_map_read_page(&handle, &swsusp_info);
|
|
if (!error)
|
|
error = check_header();
|
|
if (error)
|
|
return error;
|
|
nr_pages = swsusp_info.image_pages;
|
|
p = alloc_pagedir(nr_pages, GFP_ATOMIC, 0);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
error = load_image_metadata(p, &handle);
|
|
if (!error) {
|
|
mark_unsafe_pages(p);
|
|
pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1);
|
|
if (pblist)
|
|
copy_page_backup_list(pblist, p);
|
|
free_pagedir(p);
|
|
if (!pblist)
|
|
error = -ENOMEM;
|
|
|
|
/* Allocate memory for the image and read the data from swap */
|
|
if (!error)
|
|
error = alloc_data_pages(pblist, GFP_ATOMIC, 1);
|
|
if (!error) {
|
|
release_eaten_pages();
|
|
error = load_image_data(pblist, &handle, nr_pages);
|
|
}
|
|
if (!error)
|
|
*pblist_ptr = pblist;
|
|
}
|
|
release_swap_map_reader(&handle);
|
|
|
|
blkdev_put(resume_bdev);
|
|
|
|
if (!error)
|
|
pr_debug("swsusp: Reading resume file was successful\n");
|
|
else
|
|
pr_debug("swsusp: Error %d resuming\n", error);
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* swsusp_check - Check for swsusp signature in the resume device
|
|
*/
|
|
|
|
int swsusp_check(void)
|
|
{
|
|
int error;
|
|
|
|
resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
|
|
if (!IS_ERR(resume_bdev)) {
|
|
set_blocksize(resume_bdev, PAGE_SIZE);
|
|
memset(&swsusp_header, 0, sizeof(swsusp_header));
|
|
if ((error = bio_read_page(0, &swsusp_header)))
|
|
return error;
|
|
if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
|
|
memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
|
|
/* Reset swap signature now */
|
|
error = bio_write_page(0, &swsusp_header);
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
if (error)
|
|
blkdev_put(resume_bdev);
|
|
else
|
|
pr_debug("swsusp: Signature found, resuming\n");
|
|
} else {
|
|
error = PTR_ERR(resume_bdev);
|
|
}
|
|
|
|
if (error)
|
|
pr_debug("swsusp: Error %d check for resume file\n", error);
|
|
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* swsusp_close - close swap device.
|
|
*/
|
|
|
|
void swsusp_close(void)
|
|
{
|
|
if (IS_ERR(resume_bdev)) {
|
|
pr_debug("swsusp: block device not initialised\n");
|
|
return;
|
|
}
|
|
|
|
blkdev_put(resume_bdev);
|
|
}
|