/*
* linux/kernel/power/swsusp.c
*
- * This file is to realize architecture-independent
- * machine suspend feature using pretty near only high-level routines
+ * 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>
* Alex Badea <vampire@go.ro>:
* Fixed runaway init
*
- * Andreas Steinmetz <ast@domdv.de>:
- * Added encrypted suspend option
+ * Rafael J. Wysocki <rjw@sisk.pl>
+ * Reworked the freeing of memory and 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/reboot.h>
-#include <linux/bitops.h>
-#include <linux/vt_kern.h>
-#include <linux/kbd_kern.h>
-#include <linux/keyboard.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/console.h>
#include <linux/highmem.h>
-#include <linux/bio.h>
-#include <linux/mount.h>
-
-#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
-#include <asm/io.h>
-
-#include <linux/random.h>
-#include <linux/crypto.h>
-#include <asm/scatterlist.h>
#include "power.h"
-#define CIPHER "aes"
-#define MAXKEY 32
-#define MAXIV 32
-
-extern char resume_file[];
-
-/* Local variables that should not be affected by save */
-unsigned int nr_copy_pages __nosavedata = 0;
-
-/* Suspend pagedir is allocated before final copy, therefore it
- must be freed after resume
-
- Warning: this is evil. There are actually two pagedirs at time of
- resume. One is "pagedir_save", which is empty frame allocated at
- time of suspend, that must be freed. Second is "pagedir_nosave",
- allocated at time of resume, that travels through memory not to
- collide with anything.
-
- Warning: this is even more evil than it seems. Pagedirs this file
- talks about are completely different from page directories used by
- MMU hardware.
- */
-suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
-suspend_pagedir_t *pagedir_save;
-
-#define SWSUSP_SIG "S1SUSPEND"
-
-static struct swsusp_header {
- char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
- u8 key_iv[MAXKEY+MAXIV];
- swp_entry_t swsusp_info;
- char orig_sig[10];
- char sig[10];
-} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
-
-static struct swsusp_info swsusp_info;
-
/*
- * Saving part...
+ * 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;
-/* We memorize in swapfile_used what swap devices are used for suspension */
-#define SWAPFILE_UNUSED 0
-#define SWAPFILE_SUSPEND 1 /* This is the suspending device */
-#define SWAPFILE_IGNORED 2 /* Those are other swap devices ignored for suspension */
-
-static unsigned short swapfile_used[MAX_SWAPFILES];
-static unsigned short root_swap;
-
-static int write_page(unsigned long addr, swp_entry_t * loc);
-static int bio_read_page(pgoff_t page_off, void * page);
-
-static u8 key_iv[MAXKEY+MAXIV];
-
-#ifdef CONFIG_SWSUSP_ENCRYPT
-
-static int crypto_init(int mode, void **mem)
-{
- int error = 0;
- int len;
- char *modemsg;
- struct crypto_tfm *tfm;
-
- modemsg = mode ? "suspend not possible" : "resume not possible";
-
- tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
- if(!tfm) {
- printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
- error = -EINVAL;
- goto out;
- }
-
- if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
- printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
- error = -ENOKEY;
- goto fail;
- }
-
- if (mode)
- get_random_bytes(key_iv, MAXKEY+MAXIV);
-
- len = crypto_tfm_alg_max_keysize(tfm);
- if (len > MAXKEY)
- len = MAXKEY;
-
- if (crypto_cipher_setkey(tfm, key_iv, len)) {
- printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
- error = -EKEYREJECTED;
- goto fail;
- }
-
- len = crypto_tfm_alg_ivsize(tfm);
-
- if (MAXIV < len) {
- printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
- error = -EOVERFLOW;
- goto fail;
- }
-
- crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);
-
- *mem=(void *)tfm;
-
- goto out;
-
-fail: crypto_free_tfm(tfm);
-out: return error;
-}
-
-static __inline__ void crypto_exit(void *mem)
-{
- crypto_free_tfm((struct crypto_tfm *)mem);
-}
-
-static __inline__ int crypto_write(struct pbe *p, void *mem)
-{
- int error = 0;
- struct scatterlist src, dst;
-
- src.page = virt_to_page(p->address);
- src.offset = 0;
- src.length = PAGE_SIZE;
- dst.page = virt_to_page((void *)&swsusp_header);
- dst.offset = 0;
- dst.length = PAGE_SIZE;
-
- error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
- PAGE_SIZE);
-
- if (!error)
- error = write_page((unsigned long)&swsusp_header,
- &(p->swap_address));
- return error;
-}
-
-static __inline__ int crypto_read(struct pbe *p, void *mem)
-{
- int error = 0;
- struct scatterlist src, dst;
-
- error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
- if (!error) {
- src.offset = 0;
- src.length = PAGE_SIZE;
- dst.offset = 0;
- dst.length = PAGE_SIZE;
- src.page = dst.page = virt_to_page((void *)p->address);
+int in_suspend __nosavedata = 0;
- error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
- &src, PAGE_SIZE);
- }
- return error;
-}
+#ifdef CONFIG_HIGHMEM
+unsigned int count_highmem_pages(void);
+int save_highmem(void);
+int restore_highmem(void);
#else
-static __inline__ int crypto_init(int mode, void *mem)
-{
- return 0;
-}
-
-static __inline__ void crypto_exit(void *mem)
-{
-}
-
-static __inline__ int crypto_write(struct pbe *p, void *mem)
-{
- return write_page(p->address, &(p->swap_address));
-}
-
-static __inline__ int crypto_read(struct pbe *p, void *mem)
-{
- return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
-}
+static inline int save_highmem(void) { return 0; }
+static inline int restore_highmem(void) { return 0; }
+static inline unsigned int count_highmem_pages(void) { return 0; }
#endif
-static int mark_swapfiles(swp_entry_t prev)
-{
- 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);
- memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
- swsusp_header.swsusp_info = prev;
- 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 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, len;
-
- len=strlen(resume_file);
- root_swap = 0xFFFF;
-
- spin_lock(&swap_lock);
- for (i=0; i<MAX_SWAPFILES; i++) {
- if (!(swap_info[i].flags & SWP_WRITEOK)) {
- swapfile_used[i]=SWAPFILE_UNUSED;
- } else {
- if (!len) {
- printk(KERN_WARNING "resume= option should be used to set suspend device" );
- if (root_swap == 0xFFFF) {
- swapfile_used[i] = SWAPFILE_SUSPEND;
- root_swap = i;
- } else
- swapfile_used[i] = SWAPFILE_IGNORED;
- } else {
- /* we ignore all swap devices that are not the resume_file */
- if (is_resume_device(&swap_info[i])) {
- swapfile_used[i] = SWAPFILE_SUSPEND;
- root_swap = i;
- } else {
- swapfile_used[i] = SWAPFILE_IGNORED;
- }
- }
- }
- }
- spin_unlock(&swap_lock);
- return (root_swap != 0xffff) ? 0 : -ENODEV;
-}
-
-/**
- * This is called after saving image so modification
- * will be lost after resume... and that's what we want.
- * we make the device unusable. A new call to
- * lock_swapdevices can unlock the devices.
- */
-static void lock_swapdevices(void)
-{
- int i;
-
- spin_lock(&swap_lock);
- for (i = 0; i< MAX_SWAPFILES; i++)
- if (swapfile_used[i] == SWAPFILE_IGNORED) {
- swap_info[i].flags ^= SWP_WRITEOK;
- }
- spin_unlock(&swap_lock);
-}
-
/**
- * write_page - Write one page to a fresh swap location.
- * @addr: Address we're writing.
- * @loc: Place to store the entry we used.
+ * The following functions are used for tracing the allocated
+ * swap pages, so that they can be freed in case of an error.
*
- * 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.
+ * The functions operate on a linked bitmap structure defined
+ * in power.h
*/
-static int write_page(unsigned long addr, swp_entry_t * loc)
-{
- swp_entry_t entry;
- int error = 0;
- entry = get_swap_page();
- if (swp_offset(entry) &&
- swapfile_used[swp_type(entry)] == SWAPFILE_SUSPEND) {
- error = rw_swap_page_sync(WRITE, entry,
- virt_to_page(addr));
- if (error == -EIO)
- error = 0;
- if (!error)
- *loc = entry;
- } else
- error = -ENOSPC;
- return error;
-}
-
-/**
- * data_free - Free the swap entries used by the saved image.
- *
- * Walk the list of used swap entries and free each one.
- * This is only used for cleanup when suspend fails.
- */
-static void data_free(void)
+void free_bitmap(struct bitmap_page *bitmap)
{
- swp_entry_t entry;
- struct pbe * p;
+ struct bitmap_page *bp;
- for_each_pbe(p, pagedir_nosave) {
- entry = p->swap_address;
- if (entry.val)
- swap_free(entry);
- else
- break;
+ while (bitmap) {
+ bp = bitmap->next;
+ free_page((unsigned long)bitmap);
+ bitmap = bp;
}
}
-/**
- * data_write - Write saved image to swap.
- *
- * Walk the list of pages in the image and sync each one to swap.
- */
-static int data_write(void)
+struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
{
- int error = 0, i = 0;
- unsigned int mod = nr_copy_pages / 100;
- struct pbe *p;
- void *tfm;
+ struct bitmap_page *bitmap, *bp;
+ unsigned int n;
- if ((error = crypto_init(1, &tfm)))
- return error;
-
- if (!mod)
- mod = 1;
+ if (!nr_bits)
+ return NULL;
- printk( "Writing data to swap (%d pages)... ", nr_copy_pages );
- for_each_pbe (p, pagedir_nosave) {
- if (!(i%mod))
- printk( "\b\b\b\b%3d%%", i / mod );
- if ((error = crypto_write(p, tfm))) {
- crypto_exit(tfm);
- return error;
+ bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
+ bp = bitmap;
+ for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) {
+ bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
+ bp = bp->next;
+ if (!bp) {
+ free_bitmap(bitmap);
+ return NULL;
}
- i++;
}
- printk("\b\b\b\bdone\n");
- crypto_exit(tfm);
- 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: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
-}
-
-static void init_header(void)
-{
- 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.suspend_pagedir = pagedir_nosave;
- swsusp_info.cpus = num_online_cpus();
- swsusp_info.image_pages = nr_copy_pages;
+ return bitmap;
}
-static int close_swap(void)
+static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
{
- swp_entry_t entry;
- int error;
+ unsigned int n;
- dump_info();
- error = write_page((unsigned long)&swsusp_info, &entry);
- if (!error) {
- printk( "S" );
- error = mark_swapfiles(entry);
- printk( "|\n" );
+ n = BITMAP_PAGE_BITS;
+ while (bitmap && n <= bit) {
+ n += BITMAP_PAGE_BITS;
+ bitmap = bitmap->next;
}
- return error;
-}
-
-/**
- * free_pagedir_entries - Free pages used by the page directory.
- *
- * This is used during suspend for error recovery.
- */
-
-static void free_pagedir_entries(void)
-{
- int i;
-
- for (i = 0; i < swsusp_info.pagedir_pages; i++)
- swap_free(swsusp_info.pagedir[i]);
+ if (!bitmap)
+ return -EINVAL;
+ n -= BITMAP_PAGE_BITS;
+ bit -= n;
+ n = 0;
+ while (bit >= BITS_PER_CHUNK) {
+ bit -= BITS_PER_CHUNK;
+ n++;
+ }
+ bitmap->chunks[n] |= (1UL << bit);
+ return 0;
}
-
-/**
- * write_pagedir - Write the array of pages holding the page directory.
- * @last: Last swap entry we write (needed for header).
- */
-
-static int write_pagedir(void)
+unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
{
- int error = 0;
- unsigned n = 0;
- struct pbe * pbe;
+ unsigned long offset;
- printk( "Writing pagedir...");
- for_each_pb_page (pbe, pagedir_nosave) {
- if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
- return error;
+ offset = swp_offset(get_swap_page_of_type(swap));
+ if (offset) {
+ if (bitmap_set(bitmap, offset)) {
+ swap_free(swp_entry(swap, offset));
+ offset = 0;
+ }
}
-
- swsusp_info.pagedir_pages = n;
- printk("done (%u pages)\n", n);
- return error;
+ return offset;
}
-/**
- * write_suspend_image - Write entire image and metadata.
- *
- */
-static int write_suspend_image(void)
+void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
{
- int error;
-
- init_header();
- if ((error = data_write()))
- goto FreeData;
+ unsigned int bit, n;
+ unsigned long test;
- if ((error = write_pagedir()))
- goto FreePagedir;
-
- if ((error = close_swap()))
- goto FreePagedir;
- Done:
- memset(key_iv, 0, MAXKEY+MAXIV);
- return error;
- FreePagedir:
- free_pagedir_entries();
- FreeData:
- data_free();
- goto Done;
+ bit = 0;
+ while (bitmap) {
+ for (n = 0; n < BITMAP_PAGE_CHUNKS; n++)
+ for (test = 1UL; test; test <<= 1) {
+ if (bitmap->chunks[n] & test)
+ swap_free(swp_entry(swap, bit));
+ bit++;
+ }
+ bitmap = bitmap->next;
+ }
}
/**
- * enough_swap - Make sure we have enough swap to save the image.
+ * swsusp_shrink_memory - Try to free as much memory as needed
*
- * Returns TRUE or FALSE after checking the total amount of swap
- * space avaiable.
+ * ... but do not OOM-kill anyone
*
- * FIXME: si_swapinfo(&i) returns all swap devices information.
- * We should only consider resume_device.
+ * Notice: all userland should be stopped before it is called, or
+ * livelock is possible.
*/
-int enough_swap(unsigned nr_pages)
+#define SHRINK_BITE 10000
+static inline unsigned long __shrink_memory(long tmp)
{
- struct sysinfo i;
-
- si_swapinfo(&i);
- pr_debug("swsusp: available swap: %lu pages\n", i.freeswap);
- return i.freeswap > (nr_pages + PAGES_FOR_IO +
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+ if (tmp > SHRINK_BITE)
+ tmp = SHRINK_BITE;
+ return shrink_all_memory(tmp);
}
-
-/* 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(void)
+int swsusp_shrink_memory(void)
{
- int error;
- device_resume();
- lock_swapdevices();
- error = write_suspend_image();
- /* This will unlock ignored swap devices since writing is finished */
- lock_swapdevices();
- return error;
-
-}
+ 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() + PAGES_FOR_IO;
+ tmp = size;
+ for_each_zone (zone)
+ if (!is_highmem(zone) && populated_zone(zone)) {
+ tmp -= zone->free_pages;
+ tmp += zone->lowmem_reserve[ZONE_NORMAL];
+ tmp += snapshot_additional_pages(zone);
+ }
+ if (tmp > 0) {
+ tmp = __shrink_memory(tmp);
+ if (!tmp)
+ return -ENOMEM;
+ pages += tmp;
+ } else if (size > image_size / PAGE_SIZE) {
+ tmp = __shrink_memory(size - (image_size / PAGE_SIZE));
+ 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();
*/
if ((error = device_power_down(PMSG_FREEZE))) {
printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
- local_irq_enable();
- return error;
+ goto Enable_irqs;
}
- if ((error = swsusp_swap_check())) {
- printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
- device_power_up();
- local_irq_enable();
- return error;
+ if ((error = save_highmem())) {
+ printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");
+ goto Restore_highmem;
}
save_processor_state();
printk(KERN_ERR "Error %d suspending\n", error);
/* Restore control flow magically appears here */
restore_processor_state();
+Restore_highmem:
restore_highmem();
+ /* NOTE: device_power_up() is just a resume() for devices
+ * that suspended with irqs off ... no overall powerup.
+ */
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))
+ /* NOTE: device_power_down() is just a suspend() with irqs off;
+ * it has no special "power things down" semantics
+ */
+ if (device_power_down(PMSG_PRETHAW))
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();
local_irq_enable();
return error;
}
-
-/**
- * On resume, for storing the PBE list and the image,
- * we can only use memory pages that do not conflict with the pages
- * which had been used before suspend.
- *
- * We don't know which pages are usable until we allocate them.
- *
- * Allocated but unusable (ie eaten) memory pages are marked so that
- * swsusp_free() can release them
- */
-
-unsigned long get_safe_page(gfp_t gfp_mask)
-{
- unsigned long m;
-
- do {
- m = get_zeroed_page(gfp_mask);
- if (m && PageNosaveFree(virt_to_page(m)))
- /* This is for swsusp_free() */
- SetPageNosave(virt_to_page(m));
- } while (m && PageNosaveFree(virt_to_page(m)));
- if (m) {
- /* This is for swsusp_free() */
- SetPageNosave(virt_to_page(m));
- SetPageNosaveFree(virt_to_page(m));
- }
- return m;
-}
-
-/**
- * check_pagedir - We ensure here that pages that the PBEs point to
- * won't collide with pages where we're going to restore from the loaded
- * pages later
- */
-
-static int check_pagedir(struct pbe *pblist)
-{
- struct pbe *p;
-
- /* This is necessary, so that we can free allocated pages
- * in case of failure
- */
- for_each_pbe (p, pblist)
- p->address = 0UL;
-
- for_each_pbe (p, pblist) {
- p->address = get_safe_page(GFP_ATOMIC);
- if (!p->address)
- return -ENOMEM;
- }
- return 0;
-}
-
-/**
- * swsusp_pagedir_relocate - It is possible, that some memory pages
- * occupied by the list of PBEs collide with pages where we're going to
- * restore from the loaded pages later. We relocate them here.
- */
-
-static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
-{
- struct zone *zone;
- unsigned long zone_pfn;
- struct pbe *pbpage, *tail, *p;
- void *m;
- int rel = 0;
-
- if (!pblist) /* a sanity check */
- return NULL;
-
- pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n",
- swsusp_info.pagedir_pages);
-
- /* 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));
-
- tail = pblist + PB_PAGE_SKIP;
-
- /* Relocate colliding pages */
-
- for_each_pb_page (pbpage, pblist) {
- if (PageNosaveFree(virt_to_page((unsigned long)pbpage))) {
- m = (void *)get_safe_page(GFP_ATOMIC | __GFP_COLD);
- if (!m)
- return NULL;
- memcpy(m, (void *)pbpage, PAGE_SIZE);
- if (pbpage == pblist)
- pblist = (struct pbe *)m;
- else
- tail->next = (struct pbe *)m;
- pbpage = (struct pbe *)m;
-
- /* We have to link the PBEs again */
- for (p = pbpage; p < pbpage + PB_PAGE_SKIP; p++)
- if (p->next) /* needed to save the end */
- p->next = p + 1;
-
- rel++;
- }
- tail = pbpage + PB_PAGE_SKIP;
- }
-
- /* This is for swsusp_free() */
- for_each_pb_page (pbpage, pblist) {
- SetPageNosave(virt_to_page(pbpage));
- SetPageNosaveFree(virt_to_page(pbpage));
- }
-
- printk("swsusp: Relocated %d pages\n", rel);
-
- return pblist;
-}
-
-/*
- * 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_get(bio);
- 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;
- }
-
- if (rw == WRITE)
- bio_set_pages_dirty(bio);
-
- atomic_set(&io_done, 1);
- submit_bio(rw | (1 << BIO_RW_SYNC), bio);
- while (atomic_read(&io_done))
- yield();
-
- 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);
-}
-
-/*
- * Sanity check if this image makes sense with this kernel/swap context
- * I really don't think that it's foolproof but more than nothing..
- */
-
-static const char * sanity_check(void)
-{
- dump_info();
- if (swsusp_info.version_code != LINUX_VERSION_CODE)
- return "kernel version";
- if (swsusp_info.num_physpages != num_physpages)
- return "memory size";
- if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
- return "system type";
- if (strcmp(swsusp_info.uts.release,system_utsname.release))
- return "kernel release";
- if (strcmp(swsusp_info.uts.version,system_utsname.version))
- return "version";
- if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
- return "machine";
-#if 0
- /* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
- if (swsusp_info.cpus != num_possible_cpus())
- return "number of cpus";
-#endif
- return NULL;
-}
-
-
-static int check_header(void)
-{
- const char * reason = NULL;
- int error;
-
- if ((error = bio_read_page(swp_offset(swsusp_header.swsusp_info), &swsusp_info)))
- return error;
-
- /* Is this same machine? */
- if ((reason = sanity_check())) {
- printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
- return -EPERM;
- }
- nr_copy_pages = swsusp_info.image_pages;
- return error;
-}
-
-static int check_sig(void)
-{
- int error;
-
- 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);
- memcpy(key_iv, swsusp_header.key_iv, MAXKEY+MAXIV);
- memset(swsusp_header.key_iv, 0, MAXKEY+MAXIV);
-
- /*
- * Reset swap signature now.
- */
- error = bio_write_page(0, &swsusp_header);
- } else {
- return -EINVAL;
- }
- if (!error)
- pr_debug("swsusp: Signature found, resuming\n");
- return error;
-}
-
-/**
- * data_read - Read image pages from swap.
- *
- * You do not need to check for overlaps, check_pagedir()
- * already did that.
- */
-
-static int data_read(struct pbe *pblist)
-{
- struct pbe * p;
- int error = 0;
- int i = 0;
- int mod = swsusp_info.image_pages / 100;
- void *tfm;
-
- if ((error = crypto_init(0, &tfm)))
- return error;
-
- if (!mod)
- mod = 1;
-
- printk("swsusp: Reading image data (%lu pages): ",
- swsusp_info.image_pages);
-
- for_each_pbe (p, pblist) {
- if (!(i % mod))
- printk("\b\b\b\b%3d%%", i / mod);
-
- if ((error = crypto_read(p, tfm))) {
- crypto_exit(tfm);
- return error;
- }
-
- i++;
- }
- printk("\b\b\b\bdone\n");
- crypto_exit(tfm);
- return error;
-}
-
-/**
- * read_pagedir - Read page backup list pages from swap
- */
-
-static int read_pagedir(struct pbe *pblist)
-{
- struct pbe *pbpage, *p;
- unsigned i = 0;
- int error;
-
- if (!pblist)
- return -EFAULT;
-
- printk("swsusp: Reading pagedir (%lu pages)\n",
- swsusp_info.pagedir_pages);
-
- for_each_pb_page (pbpage, pblist) {
- unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);
-
- error = -EFAULT;
- if (offset) {
- p = (pbpage + PB_PAGE_SKIP)->next;
- error = bio_read_page(offset, (void *)pbpage);
- (pbpage + PB_PAGE_SKIP)->next = p;
- }
- if (error)
- break;
- }
-
- if (!error)
- BUG_ON(i != swsusp_info.pagedir_pages);
-
- return error;
-}
-
-
-static int check_suspend_image(void)
-{
- int error = 0;
-
- if ((error = check_sig()))
- return error;
-
- if ((error = check_header()))
- return error;
-
- return 0;
-}
-
-static int read_suspend_image(void)
-{
- int error = 0;
- struct pbe *p;
-
- if (!(p = alloc_pagedir(nr_copy_pages)))
- return -ENOMEM;
-
- if ((error = read_pagedir(p)))
- return error;
-
- create_pbe_list(p, nr_copy_pages);
-
- if (!(pagedir_nosave = swsusp_pagedir_relocate(p)))
- return -ENOMEM;
-
- /* Allocate memory for the image and read the data from swap */
-
- error = check_pagedir(pagedir_nosave);
-
- if (!error)
- error = data_read(pagedir_nosave);
-
- return error;
-}
-
-/**
- * swsusp_check - Check for saved image in swap
- */
-
-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);
- error = check_suspend_image();
- if (error)
- blkdev_put(resume_bdev);
- } else
- error = PTR_ERR(resume_bdev);
-
- if (!error)
- pr_debug("swsusp: resume file found\n");
- else
- pr_debug("swsusp: Error %d check for resume file\n", error);
- return error;
-}
-
-/**
- * swsusp_read - Read saved image from swap.
- */
-
-int swsusp_read(void)
-{
- int error;
-
- if (IS_ERR(resume_bdev)) {
- pr_debug("swsusp: block device not initialised\n");
- return PTR_ERR(resume_bdev);
- }
-
- error = read_suspend_image();
- blkdev_put(resume_bdev);
- memset(key_iv, 0, MAXKEY+MAXIV);
-
- if (!error)
- pr_debug("swsusp: Reading resume file was successful\n");
- else
- pr_debug("swsusp: Error %d resuming\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);
-}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff