[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / snapshot.c

/*
 * linux/kernel/power/snapshot.c
 *
 * This file provide system snapshot/restore functionality.
 *
 * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
 *
 * This file is released under the GPLv2, and is based on swsusp.c.
 *
 */


#include <linux/module.h>
#include <linux/mm.h>
#include <linux/suspend.h>
#include <linux/smp_lock.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/console.h>
#include <linux/highmem.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"

#ifdef CONFIG_HIGHMEM
struct highmem_page {
	char *data;
	struct page *page;
	struct highmem_page *next;
};

static struct highmem_page *highmem_copy;

static int save_highmem_zone(struct zone *zone)
{
	unsigned long zone_pfn;
	mark_free_pages(zone);
	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
		struct page *page;
		struct highmem_page *save;
		void *kaddr;
		unsigned long pfn = zone_pfn + zone->zone_start_pfn;

		if (!(pfn%1000))
			printk(".");
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);
		/*
		 * This condition results from rvmalloc() sans vmalloc_32()
		 * and architectural memory reservations. This should be
		 * corrected eventually when the cases giving rise to this
		 * are better understood.
		 */
		if (PageReserved(page)) {
			printk("highmem reserved page?!\n");
			continue;
		}
		BUG_ON(PageNosave(page));
		if (PageNosaveFree(page))
			continue;
		save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
		if (!save)
			return -ENOMEM;
		save->next = highmem_copy;
		save->page = page;
		save->data = (void *) get_zeroed_page(GFP_ATOMIC);
		if (!save->data) {
			kfree(save);
			return -ENOMEM;
		}
		kaddr = kmap_atomic(page, KM_USER0);
		memcpy(save->data, kaddr, PAGE_SIZE);
		kunmap_atomic(kaddr, KM_USER0);
		highmem_copy = save;
	}
	return 0;
}


static int save_highmem(void)
{
	struct zone *zone;
	int res = 0;

	pr_debug("swsusp: Saving Highmem\n");
	for_each_zone (zone) {
		if (is_highmem(zone))
			res = save_highmem_zone(zone);
		if (res)
			return res;
	}
	return 0;
}

int restore_highmem(void)
{
	printk("swsusp: Restoring Highmem\n");
	while (highmem_copy) {
		struct highmem_page *save = highmem_copy;
		void *kaddr;
		highmem_copy = save->next;

		kaddr = kmap_atomic(save->page, KM_USER0);
		memcpy(kaddr, save->data, PAGE_SIZE);
		kunmap_atomic(kaddr, KM_USER0);
		free_page((long) save->data);
		kfree(save);
	}
	return 0;
}
#else
static int save_highmem(void) { return 0; }
int restore_highmem(void) { return 0; }
#endif /* CONFIG_HIGHMEM */


static int pfn_is_nosave(unsigned long pfn)
{
	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
}

/**
 *	saveable - Determine whether a page should be cloned or not.
 *	@pfn:	The page
 *
 *	We save a page if it's Reserved, and not in the range of pages
 *	statically defined as 'unsaveable', or if it isn't reserved, and
 *	isn't part of a free chunk of pages.
 */

static int saveable(struct zone *zone, unsigned long *zone_pfn)
{
	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
	struct page *page;

	if (!pfn_valid(pfn))
		return 0;

	page = pfn_to_page(pfn);
	BUG_ON(PageReserved(page) && PageNosave(page));
	if (PageNosave(page))
		return 0;
	if (PageReserved(page) && pfn_is_nosave(pfn)) {
		pr_debug("[nosave pfn 0x%lx]", pfn);
		return 0;
	}
	if (PageNosaveFree(page))
		return 0;

	return 1;
}

static unsigned count_data_pages(void)
{
	struct zone *zone;
	unsigned long zone_pfn;
	unsigned n;

	n = 0;
	for_each_zone (zone) {
		if (is_highmem(zone))
			continue;
		mark_free_pages(zone);
		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
			n += saveable(zone, &zone_pfn);
	}
	return n;
}

static void copy_data_pages(struct pbe *pblist)
{
	struct zone *zone;
	unsigned long zone_pfn;
	struct pbe *pbe, *p;

	pbe = pblist;
	for_each_zone (zone) {
		if (is_highmem(zone))
			continue;
		mark_free_pages(zone);
		/* This is necessary for swsusp_free() */
		for_each_pb_page (p, pblist)
			SetPageNosaveFree(virt_to_page(p));
		for_each_pbe (p, pblist)
			SetPageNosaveFree(virt_to_page(p->address));
		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
			if (saveable(zone, &zone_pfn)) {
				struct page *page;
				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
				BUG_ON(!pbe);
				pbe->orig_address = (unsigned long)page_address(page);
				/* copy_page is not usable for copying task structs. */
				memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
				pbe = pbe->next;
			}
		}
	}
	BUG_ON(pbe);
}


/**
 *	free_pagedir - free pages allocated with alloc_pagedir()
 */

static void free_pagedir(struct pbe *pblist)
{
	struct pbe *pbe;

	while (pblist) {
		pbe = (pblist + PB_PAGE_SKIP)->next;
		ClearPageNosave(virt_to_page(pblist));
		ClearPageNosaveFree(virt_to_page(pblist));
		free_page((unsigned long)pblist);
		pblist = pbe;
	}
}

/**
 *	fill_pb_page - Create a list of PBEs on a given memory page
 */

static inline void fill_pb_page(struct pbe *pbpage)
{
	struct pbe *p;

	p = pbpage;
	pbpage += PB_PAGE_SKIP;
	do
		p->next = p + 1;
	while (++p < pbpage);
}

/**
 *	create_pbe_list - Create a list of PBEs on top of a given chain
 *	of memory pages allocated with alloc_pagedir()
 */

void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
{
	struct pbe *pbpage, *p;
	unsigned num = PBES_PER_PAGE;

	for_each_pb_page (pbpage, pblist) {
		if (num >= nr_pages)
			break;

		fill_pb_page(pbpage);
		num += PBES_PER_PAGE;
	}
	if (pbpage) {
		for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
			p->next = p + 1;
		p->next = NULL;
	}
	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
}

static void *alloc_image_page(void)
{
	void *res = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
	if (res) {
		SetPageNosave(virt_to_page(res));
		SetPageNosaveFree(virt_to_page(res));
	}
	return res;
}

/**
 *	alloc_pagedir - Allocate the page directory.
 *
 *	First, determine exactly how many pages we need and
 *	allocate them.
 *
 *	We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
 *	struct pbe elements (pbes) and the last element in the page points
 *	to the next page.
 *
 *	On each page we set up a list of struct_pbe elements.
 */

struct pbe *alloc_pagedir(unsigned nr_pages)
{
	unsigned num;
	struct pbe *pblist, *pbe;

	if (!nr_pages)
		return NULL;

	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
	pblist = alloc_image_page();
	/* FIXME: rewrite this ugly loop */
	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
        		pbe = pbe->next, num += PBES_PER_PAGE) {
		pbe += PB_PAGE_SKIP;
		pbe->next = alloc_image_page();
	}
	if (!pbe) { /* get_zeroed_page() failed */
		free_pagedir(pblist);
		pblist = NULL;
        }
	return pblist;
}

/**
 * Free pages we allocated for suspend. Suspend pages are alocated
 * before atomic copy, so we need to free them after resume.
 */

void swsusp_free(void)
{
	struct zone *zone;
	unsigned long zone_pfn;

	for_each_zone(zone) {
		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
			if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
				struct page * page;
				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
				if (PageNosave(page) && PageNosaveFree(page)) {
					ClearPageNosave(page);
					ClearPageNosaveFree(page);
					free_page((long) page_address(page));
				}
			}
	}
}


/**
 *	enough_free_mem - Make sure we enough free memory to snapshot.
 *
 *	Returns TRUE or FALSE after checking the number of available
 *	free pages.
 */

static int enough_free_mem(unsigned nr_pages)
{
	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
	return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
		(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
}


static struct pbe *swsusp_alloc(unsigned nr_pages)
{
	struct pbe *pblist, *p;

	if (!(pblist = alloc_pagedir(nr_pages))) {
		printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
		return NULL;
	}
	create_pbe_list(pblist, nr_pages);

	for_each_pbe (p, pblist) {
		p->address = (unsigned long)alloc_image_page();
		if (!p->address) {
			printk(KERN_ERR "suspend: Allocating image pages failed.\n");
			swsusp_free();
			return NULL;
		}
	}

	return pblist;
}

asmlinkage int swsusp_save(void)
{
	unsigned nr_pages;

	pr_debug("swsusp: critical section: \n");
	if (save_highmem()) {
		printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
		restore_highmem();
		return -ENOMEM;
	}

	drain_local_pages();
	nr_pages = count_data_pages();
	printk("swsusp: Need to copy %u pages\n", nr_pages);

	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
		 nr_pages,
		 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
		 PAGES_FOR_IO, nr_free_pages());

	/* This is needed because of the fixed size of swsusp_info */
	if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
		return -ENOSPC;

	if (!enough_free_mem(nr_pages)) {
		printk(KERN_ERR "swsusp: Not enough free memory\n");
		return -ENOMEM;
	}

	if (!enough_swap(nr_pages)) {
		printk(KERN_ERR "swsusp: Not enough free swap\n");
		return -ENOSPC;
	}

	pagedir_nosave = swsusp_alloc(nr_pages);
	if (!pagedir_nosave)
		return -ENOMEM;

	/* During allocating of suspend pagedir, new cold pages may appear.
	 * Kill them.
	 */
	drain_local_pages();
	copy_data_pages(pagedir_nosave);

	/*
	 * End of critical section. From now on, we can write to memory,
	 * but we should not touch disk. This specially means we must _not_
	 * touch swap space! Except we must write out our image of course.
	 */

	nr_copy_pages = nr_pages;

	printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
	return 0;
}
Commit	Line	Data
25761b6e	1	/*
96bc7aec	2	* linux/kernel/power/snapshot.c
25761b6e	3	*
96bc7aec	4	* This file provide system snapshot/restore functionality.
25761b6e RW	5	*
	6	* Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
	7	*
	8	* This file is released under the GPLv2, and is based on swsusp.c.
	9	*
	10	*/
	11
	12
	13	#include <linux/module.h>
	14	#include <linux/mm.h>
	15	#include <linux/suspend.h>
	16	#include <linux/smp_lock.h>
25761b6e	17	#include <linux/delay.h>
25761b6e	18	#include <linux/bitops.h>
25761b6e	19	#include <linux/spinlock.h>
25761b6e	20	#include <linux/kernel.h>
25761b6e RW	21	#include <linux/pm.h>
25761b6e RW	22	#include <linux/device.h>
25761b6e RW	23	#include <linux/bootmem.h>
	24	#include <linux/syscalls.h>
	25	#include <linux/console.h>
	26	#include <linux/highmem.h>
25761b6e RW	27
	28	#include <asm/uaccess.h>
	29	#include <asm/mmu_context.h>
	30	#include <asm/pgtable.h>
	31	#include <asm/tlbflush.h>
	32	#include <asm/io.h>
	33
25761b6e RW	34	#include "power.h"
25761b6e RW	35
25761b6e RW	36	#ifdef CONFIG_HIGHMEM
	37	struct highmem_page {
	38	char *data;
	39	struct page *page;
	40	struct highmem_page *next;
	41	};
	42
	43	static struct highmem_page *highmem_copy;
	44
	45	static int save_highmem_zone(struct zone *zone)
	46	{
	47	unsigned long zone_pfn;
	48	mark_free_pages(zone);
	49	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	50	struct page *page;
	51	struct highmem_page *save;
	52	void *kaddr;
	53	unsigned long pfn = zone_pfn + zone->zone_start_pfn;
	54
	55	if (!(pfn%1000))
	56	printk(".");
	57	if (!pfn_valid(pfn))
	58	continue;
	59	page = pfn_to_page(pfn);
	60	/*
	61	* This condition results from rvmalloc() sans vmalloc_32()
	62	* and architectural memory reservations. This should be
	63	* corrected eventually when the cases giving rise to this
	64	* are better understood.
	65	*/
	66	if (PageReserved(page)) {
	67	printk("highmem reserved page?!\n");
	68	continue;
	69	}
	70	BUG_ON(PageNosave(page));
	71	if (PageNosaveFree(page))
	72	continue;
	73	save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
	74	if (!save)
	75	return -ENOMEM;
	76	save->next = highmem_copy;
	77	save->page = page;
	78	save->data = (void *) get_zeroed_page(GFP_ATOMIC);
	79	if (!save->data) {
	80	kfree(save);
	81	return -ENOMEM;
	82	}
	83	kaddr = kmap_atomic(page, KM_USER0);
	84	memcpy(save->data, kaddr, PAGE_SIZE);
	85	kunmap_atomic(kaddr, KM_USER0);
	86	highmem_copy = save;
	87	}
	88	return 0;
	89	}
25761b6e RW	90
	91
	92	static int save_highmem(void)
	93	{
25761b6e RW	94	struct zone *zone;
	95	int res = 0;
	96
	97	pr_debug("swsusp: Saving Highmem\n");
	98	for_each_zone (zone) {
	99	if (is_highmem(zone))
	100	res = save_highmem_zone(zone);
	101	if (res)
	102	return res;
	103	}
25761b6e RW	104	return 0;
	105	}
	106
	107	int restore_highmem(void)
	108	{
25761b6e RW	109	printk("swsusp: Restoring Highmem\n");
	110	while (highmem_copy) {
	111	struct highmem_page *save = highmem_copy;
	112	void *kaddr;
	113	highmem_copy = save->next;
	114
	115	kaddr = kmap_atomic(save->page, KM_USER0);
	116	memcpy(kaddr, save->data, PAGE_SIZE);
	117	kunmap_atomic(kaddr, KM_USER0);
	118	free_page((long) save->data);
	119	kfree(save);
	120	}
25761b6e RW	121	return 0;
25761b6e RW	122	}
de491861 PM	123	#else
	124	static int save_highmem(void) { return 0; }
	125	int restore_highmem(void) { return 0; }
	126	#endif /* CONFIG_HIGHMEM */
25761b6e RW	127
	128
	129	static int pfn_is_nosave(unsigned long pfn)
	130	{
	131	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
	132	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
	133	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
	134	}
	135
	136	/**
	137	* saveable - Determine whether a page should be cloned or not.
	138	* @pfn: The page
	139	*
	140	* We save a page if it's Reserved, and not in the range of pages
	141	* statically defined as 'unsaveable', or if it isn't reserved, and
	142	* isn't part of a free chunk of pages.
	143	*/
	144
de491861	145	static int saveable(struct zone zone, unsigned long zone_pfn)
25761b6e RW	146	{
25761b6e RW	147	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
de491861	148	struct page *page;
25761b6e RW	149
	150	if (!pfn_valid(pfn))
	151	return 0;
	152
	153	page = pfn_to_page(pfn);
	154	BUG_ON(PageReserved(page) && PageNosave(page));
	155	if (PageNosave(page))
	156	return 0;
	157	if (PageReserved(page) && pfn_is_nosave(pfn)) {
	158	pr_debug("[nosave pfn 0x%lx]", pfn);
	159	return 0;
	160	}
	161	if (PageNosaveFree(page))
	162	return 0;
	163
	164	return 1;
	165	}
	166
a0f49651	167	static unsigned count_data_pages(void)
25761b6e RW	168	{
	169	struct zone *zone;
	170	unsigned long zone_pfn;
a0f49651	171	unsigned n;
25761b6e	172
a0f49651	173	n = 0;
25761b6e RW	174	for_each_zone (zone) {
	175	if (is_highmem(zone))
	176	continue;
	177	mark_free_pages(zone);
	178	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
a0f49651	179	n += saveable(zone, &zone_pfn);
25761b6e	180	}
a0f49651	181	return n;
25761b6e RW	182	}
25761b6e RW	183
a0f49651	184	static void copy_data_pages(struct pbe *pblist)
25761b6e RW	185	{
	186	struct zone *zone;
	187	unsigned long zone_pfn;
a0f49651	188	struct pbe pbe, p;
25761b6e	189
a0f49651	190	pbe = pblist;
25761b6e RW	191	for_each_zone (zone) {
	192	if (is_highmem(zone))
	193	continue;
	194	mark_free_pages(zone);
	195	/* This is necessary for swsusp_free() */
a0f49651	196	for_each_pb_page (p, pblist)
25761b6e	197	SetPageNosaveFree(virt_to_page(p));
a0f49651	198	for_each_pbe (p, pblist)
25761b6e RW	199	SetPageNosaveFree(virt_to_page(p->address));
	200	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	201	if (saveable(zone, &zone_pfn)) {
de491861	202	struct page *page;
25761b6e RW	203	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	204	BUG_ON(!pbe);
	205	pbe->orig_address = (unsigned long)page_address(page);
	206	/* copy_page is not usable for copying task structs. */
	207	memcpy((void )pbe->address, (void )pbe->orig_address, PAGE_SIZE);
	208	pbe = pbe->next;
	209	}
	210	}
	211	}
	212	BUG_ON(pbe);
	213	}
	214
	215
	216	/**
	217	* free_pagedir - free pages allocated with alloc_pagedir()
	218	*/
	219
2c1b4a5c	220	static void free_pagedir(struct pbe *pblist)
25761b6e RW	221	{
	222	struct pbe *pbe;
	223
	224	while (pblist) {
	225	pbe = (pblist + PB_PAGE_SKIP)->next;
	226	ClearPageNosave(virt_to_page(pblist));
	227	ClearPageNosaveFree(virt_to_page(pblist));
	228	free_page((unsigned long)pblist);
	229	pblist = pbe;
	230	}
	231	}
	232
	233	/**
	234	* fill_pb_page - Create a list of PBEs on a given memory page
	235	*/
	236
	237	static inline void fill_pb_page(struct pbe *pbpage)
	238	{
	239	struct pbe *p;
	240
	241	p = pbpage;
	242	pbpage += PB_PAGE_SKIP;
	243	do
	244	p->next = p + 1;
	245	while (++p < pbpage);
	246	}
	247
	248	/**
	249	* create_pbe_list - Create a list of PBEs on top of a given chain
	250	* of memory pages allocated with alloc_pagedir()
	251	*/
	252
	253	void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
	254	{
	255	struct pbe pbpage, p;
	256	unsigned num = PBES_PER_PAGE;
	257
	258	for_each_pb_page (pbpage, pblist) {
	259	if (num >= nr_pages)
	260	break;
	261
	262	fill_pb_page(pbpage);
	263	num += PBES_PER_PAGE;
	264	}
	265	if (pbpage) {
	266	for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
	267	p->next = p + 1;
	268	p->next = NULL;
	269	}
	270	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
	271	}
	272
	273	static void *alloc_image_page(void)
	274	{
	275	void res = (void )get_zeroed_page(GFP_ATOMIC \| __GFP_COLD);
	276	if (res) {
	277	SetPageNosave(virt_to_page(res));
	278	SetPageNosaveFree(virt_to_page(res));
	279	}
	280	return res;
	281	}
	282
	283	/**
	284	* alloc_pagedir - Allocate the page directory.
285	*
286	* First, determine exactly how many pages we need and
287	* allocate them.
288	*
289	* We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
290	* struct pbe elements (pbes) and the last element in the page points
291	* to the next page.
292	*
293	* On each page we set up a list of struct_pbe elements.
294	*/
295
de491861	296	struct pbe *alloc_pagedir(unsigned nr_pages)
25761b6e RW	297	{
	298	unsigned num;
	299	struct pbe pblist, pbe;
	300
	301	if (!nr_pages)
	302	return NULL;
	303
	304	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
de491861	305	pblist = alloc_image_page();
25761b6e RW	306	/* FIXME: rewrite this ugly loop */
	307	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
	308	pbe = pbe->next, num += PBES_PER_PAGE) {
	309	pbe += PB_PAGE_SKIP;
de491861	310	pbe->next = alloc_image_page();
25761b6e RW	311	}
	312	if (!pbe) { /* get_zeroed_page() failed */
	313	free_pagedir(pblist);
	314	pblist = NULL;
	315	}
	316	return pblist;
	317	}
	318
	319	/**
	320	* Free pages we allocated for suspend. Suspend pages are alocated
	321	* before atomic copy, so we need to free them after resume.
	322	*/
	323
	324	void swsusp_free(void)
	325	{
	326	struct zone *zone;
	327	unsigned long zone_pfn;
	328
	329	for_each_zone(zone) {
	330	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
	331	if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
	332	struct page * page;
	333	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	334	if (PageNosave(page) && PageNosaveFree(page)) {
	335	ClearPageNosave(page);
	336	ClearPageNosaveFree(page);
	337	free_page((long) page_address(page));
	338	}
	339	}
	340	}
	341	}
	342
	343
	344	/**
	345	* enough_free_mem - Make sure we enough free memory to snapshot.
	346	*
	347	* Returns TRUE or FALSE after checking the number of available
	348	* free pages.
	349	*/
	350
a0f49651	351	static int enough_free_mem(unsigned nr_pages)
25761b6e RW	352	{
25761b6e RW	353	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
a0f49651 RW	354	return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
a0f49651 RW	355	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
25761b6e RW	356	}
	357
	358
a0f49651	359	static struct pbe *swsusp_alloc(unsigned nr_pages)
25761b6e	360	{
a0f49651	361	struct pbe pblist, p;
25761b6e	362
a0f49651	363	if (!(pblist = alloc_pagedir(nr_pages))) {
25761b6e	364	printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
a0f49651	365	return NULL;
25761b6e	366	}
a0f49651	367	create_pbe_list(pblist, nr_pages);
25761b6e	368
a0f49651	369	for_each_pbe (p, pblist) {
25761b6e RW	370	p->address = (unsigned long)alloc_image_page();
	371	if (!p->address) {
	372	printk(KERN_ERR "suspend: Allocating image pages failed.\n");
	373	swsusp_free();
a0f49651	374	return NULL;
25761b6e RW	375	}
	376	}
	377
a0f49651	378	return pblist;
25761b6e RW	379	}
25761b6e RW	380
2e32a43e	381	asmlinkage int swsusp_save(void)
25761b6e	382	{
a0f49651	383	unsigned nr_pages;
25761b6e RW	384
	385	pr_debug("swsusp: critical section: \n");
	386	if (save_highmem()) {
	387	printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
	388	restore_highmem();
	389	return -ENOMEM;
	390	}
	391
	392	drain_local_pages();
a0f49651 RW	393	nr_pages = count_data_pages();
a0f49651 RW	394	printk("swsusp: Need to copy %u pages\n", nr_pages);
25761b6e RW	395
25761b6e RW	396	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
a0f49651 RW	397	nr_pages,
a0f49651 RW	398	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
25761b6e RW	399	PAGES_FOR_IO, nr_free_pages());
25761b6e RW	400
a0f49651 RW	401	/* This is needed because of the fixed size of swsusp_info */
	402	if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
	403	return -ENOSPC;
	404
	405	if (!enough_free_mem(nr_pages)) {
25761b6e RW	406	printk(KERN_ERR "swsusp: Not enough free memory\n");
	407	return -ENOMEM;
	408	}
	409
a0f49651	410	if (!enough_swap(nr_pages)) {
25761b6e RW	411	printk(KERN_ERR "swsusp: Not enough free swap\n");
	412	return -ENOSPC;
	413	}
	414
a0f49651 RW	415	pagedir_nosave = swsusp_alloc(nr_pages);
	416	if (!pagedir_nosave)
	417	return -ENOMEM;
25761b6e RW	418
	419	/* During allocating of suspend pagedir, new cold pages may appear.
	420	* Kill them.
	421	*/
	422	drain_local_pages();
a0f49651	423	copy_data_pages(pagedir_nosave);
25761b6e RW	424
	425	/*
	426	* End of critical section. From now on, we can write to memory,
	427	* but we should not touch disk. This specially means we must _not_
	428	* touch swap space! Except we must write out our image of course.
	429	*/
	430
a0f49651 RW	431	nr_copy_pages = nr_pages;
	432
	433	printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
25761b6e RW	434	return 0;
25761b6e RW	435	}