[deliverable/linux.git] / kernel / power / swsusp.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>
 * 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/mm.h>
#include <linux/suspend.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/rbtree.h>
#include <linux/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;

int in_suspend __nosavedata = 0;

/**
 *	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 = container_of(*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 entres 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 = container_of(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);
}

/**
 *	swsusp_show_speed - print the time elapsed between two events represented by
 *	@start and @stop
 *
 *	@nr_pages -	number of pages processed between @start and @stop
 *	@msg -		introductory message to print
 */

void swsusp_show_speed(struct timeval *start, struct timeval *stop,
			unsigned nr_pages, char *msg)
{
	s64 elapsed_centisecs64;
	int centisecs;
	int k;
	int kps;

	elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
	do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
	centisecs = elapsed_centisecs64;
	if (centisecs == 0)
		centisecs = 1;	/* avoid div-by-zero */
	k = nr_pages * (PAGE_SIZE / 1024);
	kps = (k * 100) / centisecs;
	printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
			msg, k,
			centisecs / 100, centisecs % 100,
			kps / 1000, (kps % 1000) / 10);
}

/**
 *	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
static inline unsigned long __shrink_memory(long tmp)
{
	if (tmp > SHRINK_BITE)
		tmp = SHRINK_BITE;
	return shrink_all_memory(tmp);
}

int swsusp_shrink_memory(void)
{
	long tmp;
	struct zone *zone;
	unsigned long pages = 0;
	unsigned int i = 0;
	char *p = "-\\|/";
	struct timeval start, stop;

	printk(KERN_INFO "PM: Shrinking memory...  ");
	do_gettimeofday(&start);
	do {
		long size, highmem_size;

		highmem_size = count_highmem_pages();
		size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES;
		tmp = size;
		size += highmem_size;
		for_each_populated_zone(zone) {
			tmp += snapshot_additional_pages(zone);
			if (is_highmem(zone)) {
				highmem_size -=
					zone_page_state(zone, NR_FREE_PAGES);
			} else {
				tmp -= zone_page_state(zone, NR_FREE_PAGES);
				tmp += zone->lowmem_reserve[ZONE_NORMAL];
			}
		}

		if (highmem_size < 0)
			highmem_size = 0;

		tmp += highmem_size;
		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);
	do_gettimeofday(&stop);
	printk("\bdone (%lu pages freed)\n", pages);
	swsusp_show_speed(&start, &stop, pages, "Freed");

	return 0;
}

/*
 * Platforms, like ACPI, may want us to save some memory used by them during
 * hibernation and to restore the contents of this memory during the subsequent
 * resume.  The code below implements a mechanism allowing us to do that.
 */

struct nvs_page {
	unsigned long phys_start;
	unsigned int size;
	void *kaddr;
	void *data;
	struct list_head node;
};

static LIST_HEAD(nvs_list);

/**
 *	hibernate_nvs_register - register platform NVS memory region to save
 *	@start - physical address of the region
 *	@size - size of the region
 *
 *	The NVS region need not be page-aligned (both ends) and we arrange
 *	things so that the data from page-aligned addresses in this region will
 *	be copied into separate RAM pages.
 */
int hibernate_nvs_register(unsigned long start, unsigned long size)
{
	struct nvs_page *entry, *next;

	while (size > 0) {
		unsigned int nr_bytes;

		entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
		if (!entry)
			goto Error;

		list_add_tail(&entry->node, &nvs_list);
		entry->phys_start = start;
		nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
		entry->size = (size < nr_bytes) ? size : nr_bytes;

		start += entry->size;
		size -= entry->size;
	}
	return 0;

 Error:
	list_for_each_entry_safe(entry, next, &nvs_list, node) {
		list_del(&entry->node);
		kfree(entry);
	}
	return -ENOMEM;
}

/**
 *	hibernate_nvs_free - free data pages allocated for saving NVS regions
 */
void hibernate_nvs_free(void)
{
	struct nvs_page *entry;

	list_for_each_entry(entry, &nvs_list, node)
		if (entry->data) {
			free_page((unsigned long)entry->data);
			entry->data = NULL;
			if (entry->kaddr) {
				iounmap(entry->kaddr);
				entry->kaddr = NULL;
			}
		}
}

/**
 *	hibernate_nvs_alloc - allocate memory necessary for saving NVS regions
 */
int hibernate_nvs_alloc(void)
{
	struct nvs_page *entry;

	list_for_each_entry(entry, &nvs_list, node) {
		entry->data = (void *)__get_free_page(GFP_KERNEL);
		if (!entry->data) {
			hibernate_nvs_free();
			return -ENOMEM;
		}
	}
	return 0;
}

/**
 *	hibernate_nvs_save - save NVS memory regions
 */
void hibernate_nvs_save(void)
{
	struct nvs_page *entry;

	printk(KERN_INFO "PM: Saving platform NVS memory\n");

	list_for_each_entry(entry, &nvs_list, node)
		if (entry->data) {
			entry->kaddr = ioremap(entry->phys_start, entry->size);
			memcpy(entry->data, entry->kaddr, entry->size);
		}
}

/**
 *	hibernate_nvs_restore - restore NVS memory regions
 *
 *	This function is going to be called with interrupts disabled, so it
 *	cannot iounmap the virtual addresses used to access the NVS region.
 */
void hibernate_nvs_restore(void)
{
	struct nvs_page *entry;

	printk(KERN_INFO "PM: Restoring platform NVS memory\n");

	list_for_each_entry(entry, &nvs_list, node)
		if (entry->data)
			memcpy(entry->kaddr, entry->data, entry->size);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/kernel/power/swsusp.c
	3	*
96bc7aec	4	* This file provides code to write suspend image to swap and read it back.
1da177e4 LT	5	*
1da177e4 LT	6	* Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
25761b6e	7	* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
1da177e4 LT	8	*
	9	* This file is released under the GPLv2.
	10	*
	11	* I'd like to thank the following people for their work:
2e4d5822	12	*
1da177e4 LT	13	* Pavel Machek <pavel@ucw.cz>:
	14	* Modifications, defectiveness pointing, being with me at the very beginning,
	15	* suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
	16	*
2e4d5822	17	* Steve Doddi <dirk@loth.demon.co.uk>:
1da177e4 LT	18	* Support the possibility of hardware state restoring.
	19	*
	20	* Raph <grey.havens@earthling.net>:
	21	* Support for preserving states of network devices and virtual console
	22	* (including X and svgatextmode)
	23	*
	24	* Kurt Garloff <garloff@suse.de>:
	25	* Straightened the critical function in order to prevent compilers from
	26	* playing tricks with local variables.
	27	*
	28	* Andreas Mohr <a.mohr@mailto.de>
	29	*
	30	* Alex Badea <vampire@go.ro>:
	31	* Fixed runaway init
	32	*
7088a5c0	33	* Rafael J. Wysocki <rjw@sisk.pl>
61159a31	34	* Reworked the freeing of memory and the handling of swap
7088a5c0	35	*
1da177e4 LT	36	* More state savers are welcome. Especially for the scsi layer...
	37	*
	38	* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
	39	*/
	40
1da177e4 LT	41	#include <linux/mm.h>
1da177e4 LT	42	#include <linux/suspend.h>
1da177e4	43	#include <linux/spinlock.h>
1da177e4 LT	44	#include <linux/kernel.h>
	45	#include <linux/major.h>
	46	#include <linux/swap.h>
	47	#include <linux/pm.h>
1da177e4 LT	48	#include <linux/swapops.h>
	49	#include <linux/bootmem.h>
	50	#include <linux/syscalls.h>
1da177e4	51	#include <linux/highmem.h>
0d3a9abe	52	#include <linux/time.h>
d1d241cc	53	#include <linux/rbtree.h>
a8af7898	54	#include <linux/io.h>
1da177e4 LT	55
	56	#include "power.h"
	57
ca0aec0f	58	/*
853609b6	59	* Preferred image size in bytes (tunable via /sys/power/image_size).
ca0aec0f	60	* When it is set to N, swsusp will do its best to ensure the image
853609b6	61	* size will not exceed N bytes, but if that is impossible, it will
ca0aec0f RW	62	* try to create the smallest image possible.
ca0aec0f RW	63	*/
853609b6	64	unsigned long image_size = 500 * 1024 * 1024;
ca0aec0f	65
f577eb30 RW	66	int in_suspend __nosavedata = 0;
f577eb30 RW	67
1da177e4	68	/**
f577eb30 RW	69	* The following functions are used for tracing the allocated
f577eb30 RW	70	* swap pages, so that they can be freed in case of an error.
1da177e4	71	*/
7088a5c0	72
d1d241cc RW	73	struct swsusp_extent {
	74	struct rb_node node;
	75	unsigned long start;
	76	unsigned long end;
	77	};
1da177e4	78
d1d241cc	79	static struct rb_root swsusp_extents = RB_ROOT;
7088a5c0	80
d1d241cc	81	static int swsusp_extents_insert(unsigned long swap_offset)
7088a5c0	82	{
d1d241cc RW	83	struct rb_node **new = &(swsusp_extents.rb_node);
	84	struct rb_node *parent = NULL;
	85	struct swsusp_extent *ext;
	86
	87	/* Figure out where to put the new node */
	88	while (*new) {
	89	ext = container_of(*new, struct swsusp_extent, node);
	90	parent = *new;
	91	if (swap_offset < ext->start) {
	92	/* Try to merge */
	93	if (swap_offset == ext->start - 1) {
	94	ext->start--;
	95	return 0;
	96	}
	97	new = &((*new)->rb_left);
	98	} else if (swap_offset > ext->end) {
	99	/* Try to merge */
	100	if (swap_offset == ext->end + 1) {
	101	ext->end++;
	102	return 0;
	103	}
	104	new = &((*new)->rb_right);
	105	} else {
	106	/* It already is in the tree */
	107	return -EINVAL;
7088a5c0	108	}
1da177e4	109	}
d1d241cc RW	110	/* Add the new node and rebalance the tree. */
	111	ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
	112	if (!ext)
	113	return -ENOMEM;
	114
	115	ext->start = swap_offset;
	116	ext->end = swap_offset;
	117	rb_link_node(&ext->node, parent, new);
	118	rb_insert_color(&ext->node, &swsusp_extents);
f577eb30	119	return 0;
7088a5c0	120	}
1da177e4	121
d1d241cc RW	122	/**
	123	* alloc_swapdev_block - allocate a swap page and register that it has
	124	* been allocated, so that it can be freed in case of an error.
	125	*/
	126
	127	sector_t alloc_swapdev_block(int swap)
7088a5c0	128	{
f577eb30 RW	129	unsigned long offset;
	130
	131	offset = swp_offset(get_swap_page_of_type(swap));
	132	if (offset) {
d1d241cc	133	if (swsusp_extents_insert(offset))
f577eb30	134	swap_free(swp_entry(swap, offset));
3aef83e0 RW	135	else
3aef83e0 RW	136	return swapdev_block(swap, offset);
7088a5c0	137	}
3aef83e0	138	return 0;
7088a5c0	139	}
1da177e4	140
d1d241cc RW	141	/**
	142	* free_all_swap_pages - free swap pages allocated for saving image data.
	143	* It also frees the extents used to register which swap entres had been
	144	* allocated.
	145	*/
	146
	147	void free_all_swap_pages(int swap)
7088a5c0	148	{
d1d241cc RW	149	struct rb_node *node;
	150
	151	while ((node = swsusp_extents.rb_node)) {
	152	struct swsusp_extent *ext;
	153	unsigned long offset;
	154
	155	ext = container_of(node, struct swsusp_extent, node);
	156	rb_erase(node, &swsusp_extents);
	157	for (offset = ext->start; offset <= ext->end; offset++)
	158	swap_free(swp_entry(swap, offset));
	159
	160	kfree(ext);
1da177e4	161	}
7088a5c0 RW	162	}
7088a5c0 RW	163
d1d241cc RW	164	int swsusp_swap_in_use(void)
	165	{
	166	return (swsusp_extents.rb_node != NULL);
	167	}
	168
0d3a9abe RW	169	/**
	170	* swsusp_show_speed - print the time elapsed between two events represented by
	171	* @start and @stop
	172	*
	173	* @nr_pages - number of pages processed between @start and @stop
	174	* @msg - introductory message to print
	175	*/
	176
	177	void swsusp_show_speed(struct timeval start, struct timeval stop,
	178	unsigned nr_pages, char *msg)
	179	{
	180	s64 elapsed_centisecs64;
	181	int centisecs;
	182	int k;
	183	int kps;
	184
	185	elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
	186	do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
	187	centisecs = elapsed_centisecs64;
	188	if (centisecs == 0)
	189	centisecs = 1; /* avoid div-by-zero */
	190	k = nr_pages * (PAGE_SIZE / 1024);
	191	kps = (k * 100) / centisecs;
23976728 RW	192	printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
23976728 RW	193	msg, k,
0d3a9abe RW	194	centisecs / 100, centisecs % 100,
	195	kps / 1000, (kps % 1000) / 10);
	196	}
	197
72a97e08 RW	198	/**
	199	* swsusp_shrink_memory - Try to free as much memory as needed
	200	*
	201	* ... but do not OOM-kill anyone
	202	*
	203	* Notice: all userland should be stopped before it is called, or
	204	* livelock is possible.
	205	*/
	206
	207	#define SHRINK_BITE 10000
d6277db4 RW	208	static inline unsigned long __shrink_memory(long tmp)
	209	{
	210	if (tmp > SHRINK_BITE)
	211	tmp = SHRINK_BITE;
	212	return shrink_all_memory(tmp);
	213	}
72a97e08 RW	214
	215	int swsusp_shrink_memory(void)
	216	{
8357376d	217	long tmp;
72a97e08 RW	218	struct zone *zone;
	219	unsigned long pages = 0;
	220	unsigned int i = 0;
	221	char *p = "-\\\|/";
0d3a9abe	222	struct timeval start, stop;
72a97e08	223
23976728	224	printk(KERN_INFO "PM: Shrinking memory... ");
0d3a9abe	225	do_gettimeofday(&start);
72a97e08	226	do {
8357376d RW	227	long size, highmem_size;
	228
	229	highmem_size = count_highmem_pages();
56f99bcb	230	size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES;
b3a93a25	231	tmp = size;
8357376d	232	size += highmem_size;
ee99c71c KM	233	for_each_populated_zone(zone) {
	234	tmp += snapshot_additional_pages(zone);
	235	if (is_highmem(zone)) {
	236	highmem_size -=
d23ad423	237	zone_page_state(zone, NR_FREE_PAGES);
ee99c71c KM	238	} else {
	239	tmp -= zone_page_state(zone, NR_FREE_PAGES);
	240	tmp += zone->lowmem_reserve[ZONE_NORMAL];
a938c356	241	}
ee99c71c	242	}
8357376d RW	243
	244	if (highmem_size < 0)
	245	highmem_size = 0;
	246
	247	tmp += highmem_size;
72a97e08	248	if (tmp > 0) {
d6277db4	249	tmp = __shrink_memory(tmp);
72a97e08 RW	250	if (!tmp)
	251	return -ENOMEM;
	252	pages += tmp;
853609b6	253	} else if (size > image_size / PAGE_SIZE) {
d6277db4	254	tmp = __shrink_memory(size - (image_size / PAGE_SIZE));
b3a93a25	255	pages += tmp;
72a97e08	256	}
72a97e08 RW	257	printk("\b%c", p[i++%4]);
72a97e08 RW	258	} while (tmp > 0);
0d3a9abe	259	do_gettimeofday(&stop);
72a97e08	260	printk("\bdone (%lu pages freed)\n", pages);
0d3a9abe	261	swsusp_show_speed(&start, &stop, pages, "Freed");
72a97e08 RW	262
	263	return 0;
	264	}
3f4b0ef7 RW	265
	266	/*
	267	* Platforms, like ACPI, may want us to save some memory used by them during
	268	* hibernation and to restore the contents of this memory during the subsequent
	269	* resume. The code below implements a mechanism allowing us to do that.
	270	*/
	271
	272	struct nvs_page {
	273	unsigned long phys_start;
	274	unsigned int size;
	275	void *kaddr;
	276	void *data;
	277	struct list_head node;
	278	};
	279
	280	static LIST_HEAD(nvs_list);
	281
	282	/**
	283	* hibernate_nvs_register - register platform NVS memory region to save
	284	* @start - physical address of the region
	285	* @size - size of the region
	286	*
	287	* The NVS region need not be page-aligned (both ends) and we arrange
	288	* things so that the data from page-aligned addresses in this region will
	289	* be copied into separate RAM pages.
	290	*/
	291	int hibernate_nvs_register(unsigned long start, unsigned long size)
	292	{
	293	struct nvs_page entry, next;
	294
	295	while (size > 0) {
	296	unsigned int nr_bytes;
	297
	298	entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
	299	if (!entry)
	300	goto Error;
	301
	302	list_add_tail(&entry->node, &nvs_list);
	303	entry->phys_start = start;
	304	nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
	305	entry->size = (size < nr_bytes) ? size : nr_bytes;
	306
	307	start += entry->size;
	308	size -= entry->size;
	309	}
	310	return 0;
	311
	312	Error:
	313	list_for_each_entry_safe(entry, next, &nvs_list, node) {
	314	list_del(&entry->node);
	315	kfree(entry);
	316	}
	317	return -ENOMEM;
	318	}
	319
	320	/**
	321	* hibernate_nvs_free - free data pages allocated for saving NVS regions
	322	*/
	323	void hibernate_nvs_free(void)
	324	{
	325	struct nvs_page *entry;
	326
	327	list_for_each_entry(entry, &nvs_list, node)
	328	if (entry->data) {
329	free_page((unsigned long)entry->data);
330	entry->data = NULL;
331	if (entry->kaddr) {
332	iounmap(entry->kaddr);
333	entry->kaddr = NULL;
334	}
335	}
336	}
337
338	/**
339	* hibernate_nvs_alloc - allocate memory necessary for saving NVS regions
340	*/
341	int hibernate_nvs_alloc(void)
342	{
343	struct nvs_page *entry;
344
345	list_for_each_entry(entry, &nvs_list, node) {
346	entry->data = (void *)__get_free_page(GFP_KERNEL);
347	if (!entry->data) {
348	hibernate_nvs_free();
349	return -ENOMEM;
350	}
351	}
352	return 0;
353	}
354
355	/**
356	* hibernate_nvs_save - save NVS memory regions
357	*/
358	void hibernate_nvs_save(void)
359	{
360	struct nvs_page *entry;
361
362	printk(KERN_INFO "PM: Saving platform NVS memory\n");
363
364	list_for_each_entry(entry, &nvs_list, node)
365	if (entry->data) {
366	entry->kaddr = ioremap(entry->phys_start, entry->size);
367	memcpy(entry->data, entry->kaddr, entry->size);
368	}
369	}
370
371	/**
372	* hibernate_nvs_restore - restore NVS memory regions
373	*
374	* This function is going to be called with interrupts disabled, so it
375	* cannot iounmap the virtual addresses used to access the NVS region.
376	*/
377	void hibernate_nvs_restore(void)
378	{
379	struct nvs_page *entry;
380
381	printk(KERN_INFO "PM: Restoring platform NVS memory\n");
382
383	list_for_each_entry(entry, &nvs_list, node)
384	if (entry->data)
385	memcpy(entry->kaddr, entry->data, entry->size);
386	}