/*
|
* linux/kernel/power/swap.c
|
*
|
* This file provides functions for reading the suspend image from
|
* and writing it to a swap partition.
|
*
|
* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
|
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
|
* Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
|
*
|
* This file is released under the GPLv2.
|
*
|
*/
|
|
#define pr_fmt(fmt) "PM: " fmt
|
|
#include <linux/module.h>
|
#include <linux/file.h>
|
#include <linux/delay.h>
|
#include <linux/bitops.h>
|
#include <linux/genhd.h>
|
#include <linux/device.h>
|
#include <linux/bio.h>
|
#include <linux/blkdev.h>
|
#include <linux/swap.h>
|
#include <linux/swapops.h>
|
#include <linux/pm.h>
|
#include <linux/slab.h>
|
#include <linux/lzo.h>
|
#include <linux/vmalloc.h>
|
#include <linux/cpumask.h>
|
#include <linux/atomic.h>
|
#include <linux/kthread.h>
|
#include <linux/crc32.h>
|
#include <linux/ktime.h>
|
|
#include "power.h"
|
|
#define HIBERNATE_SIG "S1SUSPEND"
|
|
/*
|
* When reading an {un,}compressed image, we may restore pages in place,
|
* in which case some architectures need these pages cleaning before they
|
* can be executed. We don't know which pages these may be, so clean the lot.
|
*/
|
static bool clean_pages_on_read;
|
static bool clean_pages_on_decompress;
|
|
/*
|
* The swap map is a data structure used for keeping track of each page
|
* written to a swap partition. It consists of many swap_map_page
|
* structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
|
* These structures are stored on the swap and linked together with the
|
* help of the .next_swap member.
|
*
|
* The swap map is created during suspend. The swap map pages are
|
* allocated and populated one at a time, so we only need one memory
|
* page to set up the entire structure.
|
*
|
* During resume we pick up all swap_map_page structures into a list.
|
*/
|
|
#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
|
|
/*
|
* Number of free pages that are not high.
|
*/
|
static inline unsigned long low_free_pages(void)
|
{
|
return nr_free_pages() - nr_free_highpages();
|
}
|
|
/*
|
* Number of pages required to be kept free while writing the image. Always
|
* half of all available low pages before the writing starts.
|
*/
|
static inline unsigned long reqd_free_pages(void)
|
{
|
return low_free_pages() / 2;
|
}
|
|
struct swap_map_page {
|
sector_t entries[MAP_PAGE_ENTRIES];
|
sector_t next_swap;
|
};
|
|
struct swap_map_page_list {
|
struct swap_map_page *map;
|
struct swap_map_page_list *next;
|
};
|
|
/**
|
* The swap_map_handle structure is used for handling swap in
|
* a file-alike way
|
*/
|
|
struct swap_map_handle {
|
struct swap_map_page *cur;
|
struct swap_map_page_list *maps;
|
sector_t cur_swap;
|
sector_t first_sector;
|
unsigned int k;
|
unsigned long reqd_free_pages;
|
u32 crc32;
|
};
|
|
struct swsusp_header {
|
char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
|
sizeof(u32)];
|
u32 crc32;
|
sector_t image;
|
unsigned int flags; /* Flags to pass to the "boot" kernel */
|
char orig_sig[10];
|
char sig[10];
|
} __packed;
|
|
static struct swsusp_header *swsusp_header;
|
|
/**
|
* The following functions are used for tracing the allocated
|
* swap pages, so that they can be freed in case of an error.
|
*/
|
|
struct swsusp_extent {
|
struct rb_node node;
|
unsigned long start;
|
unsigned long end;
|
};
|
|
static struct rb_root swsusp_extents = RB_ROOT;
|
|
static int swsusp_extents_insert(unsigned long swap_offset)
|
{
|
struct rb_node **new = &(swsusp_extents.rb_node);
|
struct rb_node *parent = NULL;
|
struct swsusp_extent *ext;
|
|
/* Figure out where to put the new node */
|
while (*new) {
|
ext = rb_entry(*new, struct swsusp_extent, node);
|
parent = *new;
|
if (swap_offset < ext->start) {
|
/* Try to merge */
|
if (swap_offset == ext->start - 1) {
|
ext->start--;
|
return 0;
|
}
|
new = &((*new)->rb_left);
|
} else if (swap_offset > ext->end) {
|
/* Try to merge */
|
if (swap_offset == ext->end + 1) {
|
ext->end++;
|
return 0;
|
}
|
new = &((*new)->rb_right);
|
} else {
|
/* It already is in the tree */
|
return -EINVAL;
|
}
|
}
|
/* Add the new node and rebalance the tree. */
|
ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
|
if (!ext)
|
return -ENOMEM;
|
|
ext->start = swap_offset;
|
ext->end = swap_offset;
|
rb_link_node(&ext->node, parent, new);
|
rb_insert_color(&ext->node, &swsusp_extents);
|
return 0;
|
}
|
|
/**
|
* alloc_swapdev_block - allocate a swap page and register that it has
|
* been allocated, so that it can be freed in case of an error.
|
*/
|
|
sector_t alloc_swapdev_block(int swap)
|
{
|
unsigned long offset;
|
|
offset = swp_offset(get_swap_page_of_type(swap));
|
if (offset) {
|
if (swsusp_extents_insert(offset))
|
swap_free(swp_entry(swap, offset));
|
else
|
return swapdev_block(swap, offset);
|
}
|
return 0;
|
}
|
|
/**
|
* free_all_swap_pages - free swap pages allocated for saving image data.
|
* It also frees the extents used to register which swap entries had been
|
* allocated.
|
*/
|
|
void free_all_swap_pages(int swap)
|
{
|
struct rb_node *node;
|
|
while ((node = swsusp_extents.rb_node)) {
|
struct swsusp_extent *ext;
|
unsigned long offset;
|
|
ext = rb_entry(node, struct swsusp_extent, node);
|
rb_erase(node, &swsusp_extents);
|
for (offset = ext->start; offset <= ext->end; offset++)
|
swap_free(swp_entry(swap, offset));
|
|
kfree(ext);
|
}
|
}
|
|
int swsusp_swap_in_use(void)
|
{
|
return (swsusp_extents.rb_node != NULL);
|
}
|
|
/*
|
* General things
|
*/
|
|
static unsigned short root_swap = 0xffff;
|
static struct block_device *hib_resume_bdev;
|
|
struct hib_bio_batch {
|
atomic_t count;
|
wait_queue_head_t wait;
|
blk_status_t error;
|
};
|
|
static void hib_init_batch(struct hib_bio_batch *hb)
|
{
|
atomic_set(&hb->count, 0);
|
init_waitqueue_head(&hb->wait);
|
hb->error = BLK_STS_OK;
|
}
|
|
static void hib_end_io(struct bio *bio)
|
{
|
struct hib_bio_batch *hb = bio->bi_private;
|
struct page *page = bio_first_page_all(bio);
|
|
if (bio->bi_status) {
|
pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
|
MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
|
(unsigned long long)bio->bi_iter.bi_sector);
|
}
|
|
if (bio_data_dir(bio) == WRITE)
|
put_page(page);
|
else if (clean_pages_on_read)
|
flush_icache_range((unsigned long)page_address(page),
|
(unsigned long)page_address(page) + PAGE_SIZE);
|
|
if (bio->bi_status && !hb->error)
|
hb->error = bio->bi_status;
|
if (atomic_dec_and_test(&hb->count))
|
wake_up(&hb->wait);
|
|
bio_put(bio);
|
}
|
|
static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
|
struct hib_bio_batch *hb)
|
{
|
struct page *page = virt_to_page(addr);
|
struct bio *bio;
|
int error = 0;
|
|
bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
|
bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
|
bio_set_dev(bio, hib_resume_bdev);
|
bio_set_op_attrs(bio, op, op_flags);
|
|
if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
|
pr_err("Adding page to bio failed at %llu\n",
|
(unsigned long long)bio->bi_iter.bi_sector);
|
bio_put(bio);
|
return -EFAULT;
|
}
|
|
if (hb) {
|
bio->bi_end_io = hib_end_io;
|
bio->bi_private = hb;
|
atomic_inc(&hb->count);
|
submit_bio(bio);
|
} else {
|
error = submit_bio_wait(bio);
|
bio_put(bio);
|
}
|
|
return error;
|
}
|
|
static int hib_wait_io(struct hib_bio_batch *hb)
|
{
|
wait_event(hb->wait, atomic_read(&hb->count) == 0);
|
return blk_status_to_errno(hb->error);
|
}
|
|
/*
|
* Saving part
|
*/
|
|
static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
|
{
|
int error;
|
|
hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
|
swsusp_header, NULL);
|
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, HIBERNATE_SIG, 10);
|
swsusp_header->image = handle->first_sector;
|
swsusp_header->flags = flags;
|
if (flags & SF_CRC32_MODE)
|
swsusp_header->crc32 = handle->crc32;
|
error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
|
swsusp_resume_block, swsusp_header, NULL);
|
} else {
|
pr_err("Swap header not found!\n");
|
error = -ENODEV;
|
}
|
return error;
|
}
|
|
/**
|
* swsusp_swap_check - check if the resume device is a swap device
|
* and get its index (if so)
|
*
|
* This is called before saving image
|
*/
|
static int swsusp_swap_check(void)
|
{
|
int res;
|
|
res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
|
&hib_resume_bdev);
|
if (res < 0)
|
return res;
|
|
root_swap = res;
|
res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
|
if (res)
|
return res;
|
|
res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
|
if (res < 0)
|
blkdev_put(hib_resume_bdev, FMODE_WRITE);
|
|
/*
|
* Update the resume device to the one actually used,
|
* so the test_resume mode can use it in case it is
|
* invoked from hibernate() to test the snapshot.
|
*/
|
swsusp_resume_device = hib_resume_bdev->bd_dev;
|
return res;
|
}
|
|
/**
|
* write_page - Write one page to given swap location.
|
* @buf: Address we're writing.
|
* @offset: Offset of the swap page we're writing to.
|
* @hb: bio completion batch
|
*/
|
|
static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
|
{
|
void *src;
|
int ret;
|
|
if (!offset)
|
return -ENOSPC;
|
|
if (hb) {
|
src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
|
__GFP_NORETRY);
|
if (src) {
|
copy_page(src, buf);
|
} else {
|
ret = hib_wait_io(hb); /* Free pages */
|
if (ret)
|
return ret;
|
src = (void *)__get_free_page(GFP_NOIO |
|
__GFP_NOWARN |
|
__GFP_NORETRY);
|
if (src) {
|
copy_page(src, buf);
|
} else {
|
WARN_ON_ONCE(1);
|
hb = NULL; /* Go synchronous */
|
src = buf;
|
}
|
}
|
} else {
|
src = buf;
|
}
|
return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
|
}
|
|
static void release_swap_writer(struct swap_map_handle *handle)
|
{
|
if (handle->cur)
|
free_page((unsigned long)handle->cur);
|
handle->cur = NULL;
|
}
|
|
static int get_swap_writer(struct swap_map_handle *handle)
|
{
|
int ret;
|
|
ret = swsusp_swap_check();
|
if (ret) {
|
if (ret != -ENOSPC)
|
pr_err("Cannot find swap device, try swapon -a\n");
|
return ret;
|
}
|
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
|
if (!handle->cur) {
|
ret = -ENOMEM;
|
goto err_close;
|
}
|
handle->cur_swap = alloc_swapdev_block(root_swap);
|
if (!handle->cur_swap) {
|
ret = -ENOSPC;
|
goto err_rel;
|
}
|
handle->k = 0;
|
handle->reqd_free_pages = reqd_free_pages();
|
handle->first_sector = handle->cur_swap;
|
return 0;
|
err_rel:
|
release_swap_writer(handle);
|
err_close:
|
swsusp_close(FMODE_WRITE);
|
return ret;
|
}
|
|
static int swap_write_page(struct swap_map_handle *handle, void *buf,
|
struct hib_bio_batch *hb)
|
{
|
int error = 0;
|
sector_t offset;
|
|
if (!handle->cur)
|
return -EINVAL;
|
offset = alloc_swapdev_block(root_swap);
|
error = write_page(buf, offset, hb);
|
if (error)
|
return error;
|
handle->cur->entries[handle->k++] = offset;
|
if (handle->k >= MAP_PAGE_ENTRIES) {
|
offset = alloc_swapdev_block(root_swap);
|
if (!offset)
|
return -ENOSPC;
|
handle->cur->next_swap = offset;
|
error = write_page(handle->cur, handle->cur_swap, hb);
|
if (error)
|
goto out;
|
clear_page(handle->cur);
|
handle->cur_swap = offset;
|
handle->k = 0;
|
|
if (hb && low_free_pages() <= handle->reqd_free_pages) {
|
error = hib_wait_io(hb);
|
if (error)
|
goto out;
|
/*
|
* Recalculate the number of required free pages, to
|
* make sure we never take more than half.
|
*/
|
handle->reqd_free_pages = reqd_free_pages();
|
}
|
}
|
out:
|
return error;
|
}
|
|
static int flush_swap_writer(struct swap_map_handle *handle)
|
{
|
if (handle->cur && handle->cur_swap)
|
return write_page(handle->cur, handle->cur_swap, NULL);
|
else
|
return -EINVAL;
|
}
|
|
static int swap_writer_finish(struct swap_map_handle *handle,
|
unsigned int flags, int error)
|
{
|
if (!error) {
|
pr_info("S");
|
error = mark_swapfiles(handle, flags);
|
pr_cont("|\n");
|
flush_swap_writer(handle);
|
}
|
|
if (error)
|
free_all_swap_pages(root_swap);
|
release_swap_writer(handle);
|
swsusp_close(FMODE_WRITE);
|
|
return error;
|
}
|
|
/* We need to remember how much compressed data we need to read. */
|
#define LZO_HEADER sizeof(size_t)
|
|
/* Number of pages/bytes we'll compress at one time. */
|
#define LZO_UNC_PAGES 32
|
#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
|
|
/* Number of pages/bytes we need for compressed data (worst case). */
|
#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
|
LZO_HEADER, PAGE_SIZE)
|
#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
|
|
/* Maximum number of threads for compression/decompression. */
|
#define LZO_THREADS 3
|
|
/* Minimum/maximum number of pages for read buffering. */
|
#define LZO_MIN_RD_PAGES 1024
|
#define LZO_MAX_RD_PAGES 8192
|
|
|
/**
|
* save_image - save the suspend image data
|
*/
|
|
static int save_image(struct swap_map_handle *handle,
|
struct snapshot_handle *snapshot,
|
unsigned int nr_to_write)
|
{
|
unsigned int m;
|
int ret;
|
int nr_pages;
|
int err2;
|
struct hib_bio_batch hb;
|
ktime_t start;
|
ktime_t stop;
|
|
hib_init_batch(&hb);
|
|
pr_info("Saving image data pages (%u pages)...\n",
|
nr_to_write);
|
m = nr_to_write / 10;
|
if (!m)
|
m = 1;
|
nr_pages = 0;
|
start = ktime_get();
|
while (1) {
|
ret = snapshot_read_next(snapshot);
|
if (ret <= 0)
|
break;
|
ret = swap_write_page(handle, data_of(*snapshot), &hb);
|
if (ret)
|
break;
|
if (!(nr_pages % m))
|
pr_info("Image saving progress: %3d%%\n",
|
nr_pages / m * 10);
|
nr_pages++;
|
}
|
err2 = hib_wait_io(&hb);
|
stop = ktime_get();
|
if (!ret)
|
ret = err2;
|
if (!ret)
|
pr_info("Image saving done\n");
|
swsusp_show_speed(start, stop, nr_to_write, "Wrote");
|
return ret;
|
}
|
|
/**
|
* Structure used for CRC32.
|
*/
|
struct crc_data {
|
struct task_struct *thr; /* thread */
|
atomic_t ready; /* ready to start flag */
|
atomic_t stop; /* ready to stop flag */
|
unsigned run_threads; /* nr current threads */
|
wait_queue_head_t go; /* start crc update */
|
wait_queue_head_t done; /* crc update done */
|
u32 *crc32; /* points to handle's crc32 */
|
size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
|
unsigned char *unc[LZO_THREADS]; /* uncompressed data */
|
};
|
|
/**
|
* CRC32 update function that runs in its own thread.
|
*/
|
static int crc32_threadfn(void *data)
|
{
|
struct crc_data *d = data;
|
unsigned i;
|
|
while (1) {
|
wait_event(d->go, atomic_read(&d->ready) ||
|
kthread_should_stop());
|
if (kthread_should_stop()) {
|
d->thr = NULL;
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
break;
|
}
|
atomic_set(&d->ready, 0);
|
|
for (i = 0; i < d->run_threads; i++)
|
*d->crc32 = crc32_le(*d->crc32,
|
d->unc[i], *d->unc_len[i]);
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
}
|
return 0;
|
}
|
/**
|
* Structure used for LZO data compression.
|
*/
|
struct cmp_data {
|
struct task_struct *thr; /* thread */
|
atomic_t ready; /* ready to start flag */
|
atomic_t stop; /* ready to stop flag */
|
int ret; /* return code */
|
wait_queue_head_t go; /* start compression */
|
wait_queue_head_t done; /* compression done */
|
size_t unc_len; /* uncompressed length */
|
size_t cmp_len; /* compressed length */
|
unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
|
unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
|
unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
|
};
|
|
/**
|
* Compression function that runs in its own thread.
|
*/
|
static int lzo_compress_threadfn(void *data)
|
{
|
struct cmp_data *d = data;
|
|
while (1) {
|
wait_event(d->go, atomic_read(&d->ready) ||
|
kthread_should_stop());
|
if (kthread_should_stop()) {
|
d->thr = NULL;
|
d->ret = -1;
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
break;
|
}
|
atomic_set(&d->ready, 0);
|
|
d->ret = lzo1x_1_compress(d->unc, d->unc_len,
|
d->cmp + LZO_HEADER, &d->cmp_len,
|
d->wrk);
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
}
|
return 0;
|
}
|
|
/**
|
* save_image_lzo - Save the suspend image data compressed with LZO.
|
* @handle: Swap map handle to use for saving the image.
|
* @snapshot: Image to read data from.
|
* @nr_to_write: Number of pages to save.
|
*/
|
static int save_image_lzo(struct swap_map_handle *handle,
|
struct snapshot_handle *snapshot,
|
unsigned int nr_to_write)
|
{
|
unsigned int m;
|
int ret = 0;
|
int nr_pages;
|
int err2;
|
struct hib_bio_batch hb;
|
ktime_t start;
|
ktime_t stop;
|
size_t off;
|
unsigned thr, run_threads, nr_threads;
|
unsigned char *page = NULL;
|
struct cmp_data *data = NULL;
|
struct crc_data *crc = NULL;
|
|
hib_init_batch(&hb);
|
|
/*
|
* We'll limit the number of threads for compression to limit memory
|
* footprint.
|
*/
|
nr_threads = num_online_cpus() - 1;
|
nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
|
|
page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
|
if (!page) {
|
pr_err("Failed to allocate LZO page\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
|
data = vmalloc(array_size(nr_threads, sizeof(*data)));
|
if (!data) {
|
pr_err("Failed to allocate LZO data\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
for (thr = 0; thr < nr_threads; thr++)
|
memset(&data[thr], 0, offsetof(struct cmp_data, go));
|
|
crc = kmalloc(sizeof(*crc), GFP_KERNEL);
|
if (!crc) {
|
pr_err("Failed to allocate crc\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
memset(crc, 0, offsetof(struct crc_data, go));
|
|
/*
|
* Start the compression threads.
|
*/
|
for (thr = 0; thr < nr_threads; thr++) {
|
init_waitqueue_head(&data[thr].go);
|
init_waitqueue_head(&data[thr].done);
|
|
data[thr].thr = kthread_run(lzo_compress_threadfn,
|
&data[thr],
|
"image_compress/%u", thr);
|
if (IS_ERR(data[thr].thr)) {
|
data[thr].thr = NULL;
|
pr_err("Cannot start compression threads\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
}
|
|
/*
|
* Start the CRC32 thread.
|
*/
|
init_waitqueue_head(&crc->go);
|
init_waitqueue_head(&crc->done);
|
|
handle->crc32 = 0;
|
crc->crc32 = &handle->crc32;
|
for (thr = 0; thr < nr_threads; thr++) {
|
crc->unc[thr] = data[thr].unc;
|
crc->unc_len[thr] = &data[thr].unc_len;
|
}
|
|
crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
|
if (IS_ERR(crc->thr)) {
|
crc->thr = NULL;
|
pr_err("Cannot start CRC32 thread\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
|
/*
|
* Adjust the number of required free pages after all allocations have
|
* been done. We don't want to run out of pages when writing.
|
*/
|
handle->reqd_free_pages = reqd_free_pages();
|
|
pr_info("Using %u thread(s) for compression\n", nr_threads);
|
pr_info("Compressing and saving image data (%u pages)...\n",
|
nr_to_write);
|
m = nr_to_write / 10;
|
if (!m)
|
m = 1;
|
nr_pages = 0;
|
start = ktime_get();
|
for (;;) {
|
for (thr = 0; thr < nr_threads; thr++) {
|
for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
|
ret = snapshot_read_next(snapshot);
|
if (ret < 0)
|
goto out_finish;
|
|
if (!ret)
|
break;
|
|
memcpy(data[thr].unc + off,
|
data_of(*snapshot), PAGE_SIZE);
|
|
if (!(nr_pages % m))
|
pr_info("Image saving progress: %3d%%\n",
|
nr_pages / m * 10);
|
nr_pages++;
|
}
|
if (!off)
|
break;
|
|
data[thr].unc_len = off;
|
|
atomic_set(&data[thr].ready, 1);
|
wake_up(&data[thr].go);
|
}
|
|
if (!thr)
|
break;
|
|
crc->run_threads = thr;
|
atomic_set(&crc->ready, 1);
|
wake_up(&crc->go);
|
|
for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
|
wait_event(data[thr].done,
|
atomic_read(&data[thr].stop));
|
atomic_set(&data[thr].stop, 0);
|
|
ret = data[thr].ret;
|
|
if (ret < 0) {
|
pr_err("LZO compression failed\n");
|
goto out_finish;
|
}
|
|
if (unlikely(!data[thr].cmp_len ||
|
data[thr].cmp_len >
|
lzo1x_worst_compress(data[thr].unc_len))) {
|
pr_err("Invalid LZO compressed length\n");
|
ret = -1;
|
goto out_finish;
|
}
|
|
*(size_t *)data[thr].cmp = data[thr].cmp_len;
|
|
/*
|
* Given we are writing one page at a time to disk, we
|
* copy that much from the buffer, although the last
|
* bit will likely be smaller than full page. This is
|
* OK - we saved the length of the compressed data, so
|
* any garbage at the end will be discarded when we
|
* read it.
|
*/
|
for (off = 0;
|
off < LZO_HEADER + data[thr].cmp_len;
|
off += PAGE_SIZE) {
|
memcpy(page, data[thr].cmp + off, PAGE_SIZE);
|
|
ret = swap_write_page(handle, page, &hb);
|
if (ret)
|
goto out_finish;
|
}
|
}
|
|
wait_event(crc->done, atomic_read(&crc->stop));
|
atomic_set(&crc->stop, 0);
|
}
|
|
out_finish:
|
err2 = hib_wait_io(&hb);
|
stop = ktime_get();
|
if (!ret)
|
ret = err2;
|
if (!ret)
|
pr_info("Image saving done\n");
|
swsusp_show_speed(start, stop, nr_to_write, "Wrote");
|
out_clean:
|
if (crc) {
|
if (crc->thr)
|
kthread_stop(crc->thr);
|
kfree(crc);
|
}
|
if (data) {
|
for (thr = 0; thr < nr_threads; thr++)
|
if (data[thr].thr)
|
kthread_stop(data[thr].thr);
|
vfree(data);
|
}
|
if (page) free_page((unsigned long)page);
|
|
return ret;
|
}
|
|
/**
|
* 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 = count_swap_pages(root_swap, 1);
|
unsigned int required;
|
|
pr_debug("Free swap pages: %u\n", free_swap);
|
|
required = PAGES_FOR_IO + nr_pages;
|
return free_swap > required;
|
}
|
|
/**
|
* swsusp_write - Write entire image and metadata.
|
* @flags: flags to pass to the "boot" kernel in the image header
|
*
|
* 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(unsigned int flags)
|
{
|
struct swap_map_handle handle;
|
struct snapshot_handle snapshot;
|
struct swsusp_info *header;
|
unsigned long pages;
|
int error;
|
|
pages = snapshot_get_image_size();
|
error = get_swap_writer(&handle);
|
if (error) {
|
pr_err("Cannot get swap writer\n");
|
return error;
|
}
|
if (flags & SF_NOCOMPRESS_MODE) {
|
if (!enough_swap(pages)) {
|
pr_err("Not enough free swap\n");
|
error = -ENOSPC;
|
goto out_finish;
|
}
|
}
|
memset(&snapshot, 0, sizeof(struct snapshot_handle));
|
error = snapshot_read_next(&snapshot);
|
if (error < (int)PAGE_SIZE) {
|
if (error >= 0)
|
error = -EFAULT;
|
|
goto out_finish;
|
}
|
header = (struct swsusp_info *)data_of(snapshot);
|
error = swap_write_page(&handle, header, NULL);
|
if (!error) {
|
error = (flags & SF_NOCOMPRESS_MODE) ?
|
save_image(&handle, &snapshot, pages - 1) :
|
save_image_lzo(&handle, &snapshot, pages - 1);
|
}
|
out_finish:
|
error = swap_writer_finish(&handle, flags, error);
|
return error;
|
}
|
|
/**
|
* The following functions allow us to read data using a swap map
|
* in a file-alike way
|
*/
|
|
static void release_swap_reader(struct swap_map_handle *handle)
|
{
|
struct swap_map_page_list *tmp;
|
|
while (handle->maps) {
|
if (handle->maps->map)
|
free_page((unsigned long)handle->maps->map);
|
tmp = handle->maps;
|
handle->maps = handle->maps->next;
|
kfree(tmp);
|
}
|
handle->cur = NULL;
|
}
|
|
static int get_swap_reader(struct swap_map_handle *handle,
|
unsigned int *flags_p)
|
{
|
int error;
|
struct swap_map_page_list *tmp, *last;
|
sector_t offset;
|
|
*flags_p = swsusp_header->flags;
|
|
if (!swsusp_header->image) /* how can this happen? */
|
return -EINVAL;
|
|
handle->cur = NULL;
|
last = handle->maps = NULL;
|
offset = swsusp_header->image;
|
while (offset) {
|
tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
|
if (!tmp) {
|
release_swap_reader(handle);
|
return -ENOMEM;
|
}
|
memset(tmp, 0, sizeof(*tmp));
|
if (!handle->maps)
|
handle->maps = tmp;
|
if (last)
|
last->next = tmp;
|
last = tmp;
|
|
tmp->map = (struct swap_map_page *)
|
__get_free_page(GFP_NOIO | __GFP_HIGH);
|
if (!tmp->map) {
|
release_swap_reader(handle);
|
return -ENOMEM;
|
}
|
|
error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
|
if (error) {
|
release_swap_reader(handle);
|
return error;
|
}
|
offset = tmp->map->next_swap;
|
}
|
handle->k = 0;
|
handle->cur = handle->maps->map;
|
return 0;
|
}
|
|
static int swap_read_page(struct swap_map_handle *handle, void *buf,
|
struct hib_bio_batch *hb)
|
{
|
sector_t offset;
|
int error;
|
struct swap_map_page_list *tmp;
|
|
if (!handle->cur)
|
return -EINVAL;
|
offset = handle->cur->entries[handle->k];
|
if (!offset)
|
return -EFAULT;
|
error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
|
if (error)
|
return error;
|
if (++handle->k >= MAP_PAGE_ENTRIES) {
|
handle->k = 0;
|
free_page((unsigned long)handle->maps->map);
|
tmp = handle->maps;
|
handle->maps = handle->maps->next;
|
kfree(tmp);
|
if (!handle->maps)
|
release_swap_reader(handle);
|
else
|
handle->cur = handle->maps->map;
|
}
|
return error;
|
}
|
|
static int swap_reader_finish(struct swap_map_handle *handle)
|
{
|
release_swap_reader(handle);
|
|
return 0;
|
}
|
|
/**
|
* load_image - load the image using the swap map handle
|
* @handle and the snapshot handle @snapshot
|
* (assume there are @nr_pages pages to load)
|
*/
|
|
static int load_image(struct swap_map_handle *handle,
|
struct snapshot_handle *snapshot,
|
unsigned int nr_to_read)
|
{
|
unsigned int m;
|
int ret = 0;
|
ktime_t start;
|
ktime_t stop;
|
struct hib_bio_batch hb;
|
int err2;
|
unsigned nr_pages;
|
|
hib_init_batch(&hb);
|
|
clean_pages_on_read = true;
|
pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
|
m = nr_to_read / 10;
|
if (!m)
|
m = 1;
|
nr_pages = 0;
|
start = ktime_get();
|
for ( ; ; ) {
|
ret = snapshot_write_next(snapshot);
|
if (ret <= 0)
|
break;
|
ret = swap_read_page(handle, data_of(*snapshot), &hb);
|
if (ret)
|
break;
|
if (snapshot->sync_read)
|
ret = hib_wait_io(&hb);
|
if (ret)
|
break;
|
if (!(nr_pages % m))
|
pr_info("Image loading progress: %3d%%\n",
|
nr_pages / m * 10);
|
nr_pages++;
|
}
|
err2 = hib_wait_io(&hb);
|
stop = ktime_get();
|
if (!ret)
|
ret = err2;
|
if (!ret) {
|
pr_info("Image loading done\n");
|
snapshot_write_finalize(snapshot);
|
if (!snapshot_image_loaded(snapshot))
|
ret = -ENODATA;
|
}
|
swsusp_show_speed(start, stop, nr_to_read, "Read");
|
return ret;
|
}
|
|
/**
|
* Structure used for LZO data decompression.
|
*/
|
struct dec_data {
|
struct task_struct *thr; /* thread */
|
atomic_t ready; /* ready to start flag */
|
atomic_t stop; /* ready to stop flag */
|
int ret; /* return code */
|
wait_queue_head_t go; /* start decompression */
|
wait_queue_head_t done; /* decompression done */
|
size_t unc_len; /* uncompressed length */
|
size_t cmp_len; /* compressed length */
|
unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
|
unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
|
};
|
|
/**
|
* Deompression function that runs in its own thread.
|
*/
|
static int lzo_decompress_threadfn(void *data)
|
{
|
struct dec_data *d = data;
|
|
while (1) {
|
wait_event(d->go, atomic_read(&d->ready) ||
|
kthread_should_stop());
|
if (kthread_should_stop()) {
|
d->thr = NULL;
|
d->ret = -1;
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
break;
|
}
|
atomic_set(&d->ready, 0);
|
|
d->unc_len = LZO_UNC_SIZE;
|
d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
|
d->unc, &d->unc_len);
|
if (clean_pages_on_decompress)
|
flush_icache_range((unsigned long)d->unc,
|
(unsigned long)d->unc + d->unc_len);
|
|
atomic_set(&d->stop, 1);
|
wake_up(&d->done);
|
}
|
return 0;
|
}
|
|
/**
|
* load_image_lzo - Load compressed image data and decompress them with LZO.
|
* @handle: Swap map handle to use for loading data.
|
* @snapshot: Image to copy uncompressed data into.
|
* @nr_to_read: Number of pages to load.
|
*/
|
static int load_image_lzo(struct swap_map_handle *handle,
|
struct snapshot_handle *snapshot,
|
unsigned int nr_to_read)
|
{
|
unsigned int m;
|
int ret = 0;
|
int eof = 0;
|
struct hib_bio_batch hb;
|
ktime_t start;
|
ktime_t stop;
|
unsigned nr_pages;
|
size_t off;
|
unsigned i, thr, run_threads, nr_threads;
|
unsigned ring = 0, pg = 0, ring_size = 0,
|
have = 0, want, need, asked = 0;
|
unsigned long read_pages = 0;
|
unsigned char **page = NULL;
|
struct dec_data *data = NULL;
|
struct crc_data *crc = NULL;
|
|
hib_init_batch(&hb);
|
|
/*
|
* We'll limit the number of threads for decompression to limit memory
|
* footprint.
|
*/
|
nr_threads = num_online_cpus() - 1;
|
nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
|
|
page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
|
if (!page) {
|
pr_err("Failed to allocate LZO page\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
|
data = vmalloc(array_size(nr_threads, sizeof(*data)));
|
if (!data) {
|
pr_err("Failed to allocate LZO data\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
for (thr = 0; thr < nr_threads; thr++)
|
memset(&data[thr], 0, offsetof(struct dec_data, go));
|
|
crc = kmalloc(sizeof(*crc), GFP_KERNEL);
|
if (!crc) {
|
pr_err("Failed to allocate crc\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
memset(crc, 0, offsetof(struct crc_data, go));
|
|
clean_pages_on_decompress = true;
|
|
/*
|
* Start the decompression threads.
|
*/
|
for (thr = 0; thr < nr_threads; thr++) {
|
init_waitqueue_head(&data[thr].go);
|
init_waitqueue_head(&data[thr].done);
|
|
data[thr].thr = kthread_run(lzo_decompress_threadfn,
|
&data[thr],
|
"image_decompress/%u", thr);
|
if (IS_ERR(data[thr].thr)) {
|
data[thr].thr = NULL;
|
pr_err("Cannot start decompression threads\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
}
|
|
/*
|
* Start the CRC32 thread.
|
*/
|
init_waitqueue_head(&crc->go);
|
init_waitqueue_head(&crc->done);
|
|
handle->crc32 = 0;
|
crc->crc32 = &handle->crc32;
|
for (thr = 0; thr < nr_threads; thr++) {
|
crc->unc[thr] = data[thr].unc;
|
crc->unc_len[thr] = &data[thr].unc_len;
|
}
|
|
crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
|
if (IS_ERR(crc->thr)) {
|
crc->thr = NULL;
|
pr_err("Cannot start CRC32 thread\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
}
|
|
/*
|
* Set the number of pages for read buffering.
|
* This is complete guesswork, because we'll only know the real
|
* picture once prepare_image() is called, which is much later on
|
* during the image load phase. We'll assume the worst case and
|
* say that none of the image pages are from high memory.
|
*/
|
if (low_free_pages() > snapshot_get_image_size())
|
read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
|
read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
|
|
for (i = 0; i < read_pages; i++) {
|
page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
|
GFP_NOIO | __GFP_HIGH :
|
GFP_NOIO | __GFP_NOWARN |
|
__GFP_NORETRY);
|
|
if (!page[i]) {
|
if (i < LZO_CMP_PAGES) {
|
ring_size = i;
|
pr_err("Failed to allocate LZO pages\n");
|
ret = -ENOMEM;
|
goto out_clean;
|
} else {
|
break;
|
}
|
}
|
}
|
want = ring_size = i;
|
|
pr_info("Using %u thread(s) for decompression\n", nr_threads);
|
pr_info("Loading and decompressing image data (%u pages)...\n",
|
nr_to_read);
|
m = nr_to_read / 10;
|
if (!m)
|
m = 1;
|
nr_pages = 0;
|
start = ktime_get();
|
|
ret = snapshot_write_next(snapshot);
|
if (ret <= 0)
|
goto out_finish;
|
|
for(;;) {
|
for (i = 0; !eof && i < want; i++) {
|
ret = swap_read_page(handle, page[ring], &hb);
|
if (ret) {
|
/*
|
* On real read error, finish. On end of data,
|
* set EOF flag and just exit the read loop.
|
*/
|
if (handle->cur &&
|
handle->cur->entries[handle->k]) {
|
goto out_finish;
|
} else {
|
eof = 1;
|
break;
|
}
|
}
|
if (++ring >= ring_size)
|
ring = 0;
|
}
|
asked += i;
|
want -= i;
|
|
/*
|
* We are out of data, wait for some more.
|
*/
|
if (!have) {
|
if (!asked)
|
break;
|
|
ret = hib_wait_io(&hb);
|
if (ret)
|
goto out_finish;
|
have += asked;
|
asked = 0;
|
if (eof)
|
eof = 2;
|
}
|
|
if (crc->run_threads) {
|
wait_event(crc->done, atomic_read(&crc->stop));
|
atomic_set(&crc->stop, 0);
|
crc->run_threads = 0;
|
}
|
|
for (thr = 0; have && thr < nr_threads; thr++) {
|
data[thr].cmp_len = *(size_t *)page[pg];
|
if (unlikely(!data[thr].cmp_len ||
|
data[thr].cmp_len >
|
lzo1x_worst_compress(LZO_UNC_SIZE))) {
|
pr_err("Invalid LZO compressed length\n");
|
ret = -1;
|
goto out_finish;
|
}
|
|
need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
|
PAGE_SIZE);
|
if (need > have) {
|
if (eof > 1) {
|
ret = -1;
|
goto out_finish;
|
}
|
break;
|
}
|
|
for (off = 0;
|
off < LZO_HEADER + data[thr].cmp_len;
|
off += PAGE_SIZE) {
|
memcpy(data[thr].cmp + off,
|
page[pg], PAGE_SIZE);
|
have--;
|
want++;
|
if (++pg >= ring_size)
|
pg = 0;
|
}
|
|
atomic_set(&data[thr].ready, 1);
|
wake_up(&data[thr].go);
|
}
|
|
/*
|
* Wait for more data while we are decompressing.
|
*/
|
if (have < LZO_CMP_PAGES && asked) {
|
ret = hib_wait_io(&hb);
|
if (ret)
|
goto out_finish;
|
have += asked;
|
asked = 0;
|
if (eof)
|
eof = 2;
|
}
|
|
for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
|
wait_event(data[thr].done,
|
atomic_read(&data[thr].stop));
|
atomic_set(&data[thr].stop, 0);
|
|
ret = data[thr].ret;
|
|
if (ret < 0) {
|
pr_err("LZO decompression failed\n");
|
goto out_finish;
|
}
|
|
if (unlikely(!data[thr].unc_len ||
|
data[thr].unc_len > LZO_UNC_SIZE ||
|
data[thr].unc_len & (PAGE_SIZE - 1))) {
|
pr_err("Invalid LZO uncompressed length\n");
|
ret = -1;
|
goto out_finish;
|
}
|
|
for (off = 0;
|
off < data[thr].unc_len; off += PAGE_SIZE) {
|
memcpy(data_of(*snapshot),
|
data[thr].unc + off, PAGE_SIZE);
|
|
if (!(nr_pages % m))
|
pr_info("Image loading progress: %3d%%\n",
|
nr_pages / m * 10);
|
nr_pages++;
|
|
ret = snapshot_write_next(snapshot);
|
if (ret <= 0) {
|
crc->run_threads = thr + 1;
|
atomic_set(&crc->ready, 1);
|
wake_up(&crc->go);
|
goto out_finish;
|
}
|
}
|
}
|
|
crc->run_threads = thr;
|
atomic_set(&crc->ready, 1);
|
wake_up(&crc->go);
|
}
|
|
out_finish:
|
if (crc->run_threads) {
|
wait_event(crc->done, atomic_read(&crc->stop));
|
atomic_set(&crc->stop, 0);
|
}
|
stop = ktime_get();
|
if (!ret) {
|
pr_info("Image loading done\n");
|
snapshot_write_finalize(snapshot);
|
if (!snapshot_image_loaded(snapshot))
|
ret = -ENODATA;
|
if (!ret) {
|
if (swsusp_header->flags & SF_CRC32_MODE) {
|
if(handle->crc32 != swsusp_header->crc32) {
|
pr_err("Invalid image CRC32!\n");
|
ret = -ENODATA;
|
}
|
}
|
}
|
}
|
swsusp_show_speed(start, stop, nr_to_read, "Read");
|
out_clean:
|
for (i = 0; i < ring_size; i++)
|
free_page((unsigned long)page[i]);
|
if (crc) {
|
if (crc->thr)
|
kthread_stop(crc->thr);
|
kfree(crc);
|
}
|
if (data) {
|
for (thr = 0; thr < nr_threads; thr++)
|
if (data[thr].thr)
|
kthread_stop(data[thr].thr);
|
vfree(data);
|
}
|
vfree(page);
|
|
return ret;
|
}
|
|
/**
|
* swsusp_read - read the hibernation image.
|
* @flags_p: flags passed by the "frozen" kernel in the image header should
|
* be written into this memory location
|
*/
|
|
int swsusp_read(unsigned int *flags_p)
|
{
|
int error;
|
struct swap_map_handle handle;
|
struct snapshot_handle snapshot;
|
struct swsusp_info *header;
|
|
memset(&snapshot, 0, sizeof(struct snapshot_handle));
|
error = snapshot_write_next(&snapshot);
|
if (error < (int)PAGE_SIZE)
|
return error < 0 ? error : -EFAULT;
|
header = (struct swsusp_info *)data_of(snapshot);
|
error = get_swap_reader(&handle, flags_p);
|
if (error)
|
goto end;
|
if (!error)
|
error = swap_read_page(&handle, header, NULL);
|
if (!error) {
|
error = (*flags_p & SF_NOCOMPRESS_MODE) ?
|
load_image(&handle, &snapshot, header->pages - 1) :
|
load_image_lzo(&handle, &snapshot, header->pages - 1);
|
}
|
swap_reader_finish(&handle);
|
end:
|
if (!error)
|
pr_debug("Image successfully loaded\n");
|
else
|
pr_debug("Error %d resuming\n", error);
|
return error;
|
}
|
|
/**
|
* swsusp_check - Check for swsusp signature in the resume device
|
*/
|
|
int swsusp_check(void)
|
{
|
int error;
|
void *holder;
|
|
hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
|
FMODE_READ | FMODE_EXCL, &holder);
|
if (!IS_ERR(hib_resume_bdev)) {
|
set_blocksize(hib_resume_bdev, PAGE_SIZE);
|
clear_page(swsusp_header);
|
error = hib_submit_io(REQ_OP_READ, 0,
|
swsusp_resume_block,
|
swsusp_header, NULL);
|
if (error)
|
goto put;
|
|
if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
|
memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
|
/* Reset swap signature now */
|
error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
|
swsusp_resume_block,
|
swsusp_header, NULL);
|
} else {
|
error = -EINVAL;
|
}
|
|
put:
|
if (error)
|
blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
|
else
|
pr_debug("Image signature found, resuming\n");
|
} else {
|
error = PTR_ERR(hib_resume_bdev);
|
}
|
|
if (error)
|
pr_debug("Image not found (code %d)\n", error);
|
|
return error;
|
}
|
|
/**
|
* swsusp_close - close swap device.
|
*/
|
|
void swsusp_close(fmode_t mode)
|
{
|
if (IS_ERR(hib_resume_bdev)) {
|
pr_debug("Image device not initialised\n");
|
return;
|
}
|
|
blkdev_put(hib_resume_bdev, mode);
|
}
|
|
/**
|
* swsusp_unmark - Unmark swsusp signature in the resume device
|
*/
|
|
#ifdef CONFIG_SUSPEND
|
int swsusp_unmark(void)
|
{
|
int error;
|
|
hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
|
swsusp_header, NULL);
|
if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
|
memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
|
error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
|
swsusp_resume_block,
|
swsusp_header, NULL);
|
} else {
|
pr_err("Cannot find swsusp signature!\n");
|
error = -ENODEV;
|
}
|
|
/*
|
* We just returned from suspend, we don't need the image any more.
|
*/
|
free_all_swap_pages(root_swap);
|
|
return error;
|
}
|
#endif
|
|
static int swsusp_header_init(void)
|
{
|
swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
|
if (!swsusp_header)
|
panic("Could not allocate memory for swsusp_header\n");
|
return 0;
|
}
|
|
core_initcall(swsusp_header_init);
|
