[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 int 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 int nr_pages)
{
	struct pbe *pbpage, *p;
	unsigned int 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 int nr_pages)
{
	unsigned int 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 int 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 int 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 int 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;
dc19d507	171	unsigned int n = 0;
25761b6e	172
25761b6e RW	173	for_each_zone (zone) {
	174	if (is_highmem(zone))
	175	continue;
	176	mark_free_pages(zone);
	177	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
a0f49651	178	n += saveable(zone, &zone_pfn);
25761b6e	179	}
a0f49651	180	return n;
25761b6e RW	181	}
25761b6e RW	182
a0f49651	183	static void copy_data_pages(struct pbe *pblist)
25761b6e RW	184	{
	185	struct zone *zone;
	186	unsigned long zone_pfn;
a0f49651	187	struct pbe pbe, p;
25761b6e	188
a0f49651	189	pbe = pblist;
25761b6e RW	190	for_each_zone (zone) {
	191	if (is_highmem(zone))
	192	continue;
	193	mark_free_pages(zone);
	194	/* This is necessary for swsusp_free() */
a0f49651	195	for_each_pb_page (p, pblist)
25761b6e	196	SetPageNosaveFree(virt_to_page(p));
a0f49651	197	for_each_pbe (p, pblist)
25761b6e RW	198	SetPageNosaveFree(virt_to_page(p->address));
	199	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	200	if (saveable(zone, &zone_pfn)) {
de491861	201	struct page *page;
25761b6e RW	202	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	203	BUG_ON(!pbe);
	204	pbe->orig_address = (unsigned long)page_address(page);
	205	/* copy_page is not usable for copying task structs. */
	206	memcpy((void )pbe->address, (void )pbe->orig_address, PAGE_SIZE);
	207	pbe = pbe->next;
	208	}
	209	}
	210	}
	211	BUG_ON(pbe);
	212	}
	213
	214
	215	/**
	216	* free_pagedir - free pages allocated with alloc_pagedir()
	217	*/
	218
2c1b4a5c	219	static void free_pagedir(struct pbe *pblist)
25761b6e RW	220	{
	221	struct pbe *pbe;
	222
	223	while (pblist) {
	224	pbe = (pblist + PB_PAGE_SKIP)->next;
	225	ClearPageNosave(virt_to_page(pblist));
	226	ClearPageNosaveFree(virt_to_page(pblist));
	227	free_page((unsigned long)pblist);
	228	pblist = pbe;
	229	}
	230	}
	231
	232	/**
	233	* fill_pb_page - Create a list of PBEs on a given memory page
	234	*/
	235
	236	static inline void fill_pb_page(struct pbe *pbpage)
	237	{
	238	struct pbe *p;
	239
	240	p = pbpage;
	241	pbpage += PB_PAGE_SKIP;
	242	do
	243	p->next = p + 1;
	244	while (++p < pbpage);
	245	}
	246
	247	/**
	248	* create_pbe_list - Create a list of PBEs on top of a given chain
	249	* of memory pages allocated with alloc_pagedir()
	250	*/
	251
dc19d507	252	void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
25761b6e RW	253	{
25761b6e RW	254	struct pbe pbpage, p;
dc19d507	255	unsigned int num = PBES_PER_PAGE;
25761b6e RW	256
	257	for_each_pb_page (pbpage, pblist) {
	258	if (num >= nr_pages)
	259	break;
	260
	261	fill_pb_page(pbpage);
	262	num += PBES_PER_PAGE;
	263	}
	264	if (pbpage) {
	265	for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
	266	p->next = p + 1;
	267	p->next = NULL;
	268	}
	269	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
	270	}
	271
	272	static void *alloc_image_page(void)
	273	{
	274	void res = (void )get_zeroed_page(GFP_ATOMIC \| __GFP_COLD);
	275	if (res) {
	276	SetPageNosave(virt_to_page(res));
	277	SetPageNosaveFree(virt_to_page(res));
	278	}
	279	return res;
	280	}
	281
	282	/**
	283	* alloc_pagedir - Allocate the page directory.
	284	*
	285	* First, determine exactly how many pages we need and
	286	* allocate them.
	287	*
	288	* We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
	289	* struct pbe elements (pbes) and the last element in the page points
	290	* to the next page.
	291	*
	292	* On each page we set up a list of struct_pbe elements.
	293	*/
	294
dc19d507	295	struct pbe *alloc_pagedir(unsigned int nr_pages)
25761b6e	296	{
dc19d507	297	unsigned int num;
25761b6e RW	298	struct pbe pblist, pbe;
	299
	300	if (!nr_pages)
	301	return NULL;
	302
	303	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
de491861	304	pblist = alloc_image_page();
25761b6e RW	305	/* FIXME: rewrite this ugly loop */
	306	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
	307	pbe = pbe->next, num += PBES_PER_PAGE) {
	308	pbe += PB_PAGE_SKIP;
de491861	309	pbe->next = alloc_image_page();
25761b6e RW	310	}
	311	if (!pbe) { /* get_zeroed_page() failed */
	312	free_pagedir(pblist);
	313	pblist = NULL;
	314	}
	315	return pblist;
	316	}
	317
	318	/**
	319	* Free pages we allocated for suspend. Suspend pages are alocated
	320	* before atomic copy, so we need to free them after resume.
	321	*/
	322
	323	void swsusp_free(void)
	324	{
	325	struct zone *zone;
	326	unsigned long zone_pfn;
	327
	328	for_each_zone(zone) {
	329	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
	330	if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
dc19d507	331	struct page *page;
25761b6e RW	332	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	333	if (PageNosave(page) && PageNosaveFree(page)) {
	334	ClearPageNosave(page);
	335	ClearPageNosaveFree(page);
	336	free_page((long) page_address(page));
	337	}
	338	}
	339	}
	340	}
	341
	342
	343	/**
	344	* enough_free_mem - Make sure we enough free memory to snapshot.
	345	*
	346	* Returns TRUE or FALSE after checking the number of available
	347	* free pages.
	348	*/
	349
dc19d507	350	static int enough_free_mem(unsigned int nr_pages)
25761b6e RW	351	{
25761b6e RW	352	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
a0f49651 RW	353	return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
a0f49651 RW	354	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
25761b6e RW	355	}
	356
	357
dc19d507	358	static struct pbe *swsusp_alloc(unsigned int nr_pages)
25761b6e	359	{
a0f49651	360	struct pbe pblist, p;
25761b6e	361
a0f49651	362	if (!(pblist = alloc_pagedir(nr_pages))) {
25761b6e	363	printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
a0f49651	364	return NULL;
25761b6e	365	}
a0f49651	366	create_pbe_list(pblist, nr_pages);
25761b6e	367
a0f49651	368	for_each_pbe (p, pblist) {
25761b6e RW	369	p->address = (unsigned long)alloc_image_page();
	370	if (!p->address) {
	371	printk(KERN_ERR "suspend: Allocating image pages failed.\n");
	372	swsusp_free();
a0f49651	373	return NULL;
25761b6e RW	374	}
	375	}
	376
a0f49651	377	return pblist;
25761b6e RW	378	}
25761b6e RW	379
2e32a43e	380	asmlinkage int swsusp_save(void)
25761b6e	381	{
dc19d507	382	unsigned int nr_pages;
25761b6e RW	383
	384	pr_debug("swsusp: critical section: \n");
	385	if (save_highmem()) {
	386	printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
	387	restore_highmem();
	388	return -ENOMEM;
	389	}
	390
	391	drain_local_pages();
a0f49651 RW	392	nr_pages = count_data_pages();
a0f49651 RW	393	printk("swsusp: Need to copy %u pages\n", nr_pages);
25761b6e RW	394
25761b6e RW	395	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
a0f49651 RW	396	nr_pages,
a0f49651 RW	397	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
25761b6e RW	398	PAGES_FOR_IO, nr_free_pages());
25761b6e RW	399
a0f49651 RW	400	/* This is needed because of the fixed size of swsusp_info */
	401	if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
	402	return -ENOSPC;
	403
	404	if (!enough_free_mem(nr_pages)) {
25761b6e RW	405	printk(KERN_ERR "swsusp: Not enough free memory\n");
	406	return -ENOMEM;
	407	}
	408
a0f49651	409	if (!enough_swap(nr_pages)) {
25761b6e RW	410	printk(KERN_ERR "swsusp: Not enough free swap\n");
	411	return -ENOSPC;
	412	}
	413
a0f49651 RW	414	pagedir_nosave = swsusp_alloc(nr_pages);
	415	if (!pagedir_nosave)
	416	return -ENOMEM;
25761b6e RW	417
	418	/* During allocating of suspend pagedir, new cold pages may appear.
	419	* Kill them.
	420	*/
	421	drain_local_pages();
a0f49651	422	copy_data_pages(pagedir_nosave);
25761b6e RW	423
	424	/*
	425	* End of critical section. From now on, we can write to memory,
	426	* but we should not touch disk. This specially means we must _not_
	427	* touch swap space! Except we must write out our image of course.
	428	*/
	429
a0f49651 RW	430	nr_copy_pages = nr_pages;
	431
	432	printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
25761b6e RW	433	return 0;
25761b6e RW	434	}