[deliverable/linux.git] / kernel / power / snapshot.c

/*
 * linux/kernel/power/swsusp.c
 *
 * This file is to realize architecture-independent
 * machine suspend feature using pretty near only high-level routines
 *
 * 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/file.h>
#include <linux/utsname.h>
#include <linux/version.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/bitops.h>
#include <linux/vt_kern.h>
#include <linux/kbd_kern.h>
#include <linux/keyboard.h>
#include <linux/spinlock.h>
#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/buffer_head.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/console.h>
#include <linux/highmem.h>
#include <linux/bio.h>
#include <linux/mount.h>

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/io.h>

#include <linux/random.h>
#include <linux/crypto.h>
#include <asm/scatterlist.h>

#include "power.h"


#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;
}
#endif /* CONFIG_HIGHMEM */


static int save_highmem(void)
{
#ifdef CONFIG_HIGHMEM
	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;
	}
#endif
	return 0;
}

int restore_highmem(void)
{
#ifdef CONFIG_HIGHMEM
	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);
	}
#endif
	return 0;
}


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 = (struct pbe *)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 = (struct pbe *)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;
}

static int suspend_prepare_image(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;
}


asmlinkage int swsusp_save(void)
{
	return suspend_prepare_image();
}
Commit	Line	Data
25761b6e RW	1	/*
	2	* linux/kernel/power/swsusp.c
	3	*
	4	* This file is to realize architecture-independent
	5	* machine suspend feature using pretty near only high-level routines
	6	*
	7	* Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
	8	*
	9	* This file is released under the GPLv2, and is based on swsusp.c.
	10	*
	11	*/
	12
	13
	14	#include <linux/module.h>
	15	#include <linux/mm.h>
	16	#include <linux/suspend.h>
	17	#include <linux/smp_lock.h>
	18	#include <linux/file.h>
	19	#include <linux/utsname.h>
	20	#include <linux/version.h>
	21	#include <linux/delay.h>
	22	#include <linux/reboot.h>
	23	#include <linux/bitops.h>
	24	#include <linux/vt_kern.h>
	25	#include <linux/kbd_kern.h>
	26	#include <linux/keyboard.h>
	27	#include <linux/spinlock.h>
	28	#include <linux/genhd.h>
	29	#include <linux/kernel.h>
	30	#include <linux/major.h>
	31	#include <linux/swap.h>
	32	#include <linux/pm.h>
	33	#include <linux/device.h>
	34	#include <linux/buffer_head.h>
	35	#include <linux/swapops.h>
	36	#include <linux/bootmem.h>
	37	#include <linux/syscalls.h>
	38	#include <linux/console.h>
	39	#include <linux/highmem.h>
	40	#include <linux/bio.h>
	41	#include <linux/mount.h>
	42
	43	#include <asm/uaccess.h>
	44	#include <asm/mmu_context.h>
	45	#include <asm/pgtable.h>
	46	#include <asm/tlbflush.h>
	47	#include <asm/io.h>
	48
	49	#include <linux/random.h>
	50	#include <linux/crypto.h>
	51	#include <asm/scatterlist.h>
	52
	53	#include "power.h"
	54
	55
	56
	57
	58	#ifdef CONFIG_HIGHMEM
	59	struct highmem_page {
	60	char *data;
	61	struct page *page;
	62	struct highmem_page *next;
	63	};
	64
65	static struct highmem_page *highmem_copy;
66
67	static int save_highmem_zone(struct zone *zone)
68	{
69	unsigned long zone_pfn;
70	mark_free_pages(zone);
71	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
72	struct page *page;
73	struct highmem_page *save;
74	void *kaddr;
75	unsigned long pfn = zone_pfn + zone->zone_start_pfn;
76
77	if (!(pfn%1000))
78	printk(".");
79	if (!pfn_valid(pfn))
80	continue;
81	page = pfn_to_page(pfn);
82	/*
83	* This condition results from rvmalloc() sans vmalloc_32()
84	* and architectural memory reservations. This should be
85	* corrected eventually when the cases giving rise to this
86	* are better understood.
87	*/
88	if (PageReserved(page)) {
89	printk("highmem reserved page?!\n");
90	continue;
91	}
92	BUG_ON(PageNosave(page));
93	if (PageNosaveFree(page))
94	continue;
95	save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
96	if (!save)
97	return -ENOMEM;
98	save->next = highmem_copy;
99	save->page = page;
100	save->data = (void *) get_zeroed_page(GFP_ATOMIC);
101	if (!save->data) {
102	kfree(save);
103	return -ENOMEM;
104	}
105	kaddr = kmap_atomic(page, KM_USER0);
106	memcpy(save->data, kaddr, PAGE_SIZE);
107	kunmap_atomic(kaddr, KM_USER0);
108	highmem_copy = save;
109	}
110	return 0;
111	}
112	#endif /* CONFIG_HIGHMEM */
113
114
115	static int save_highmem(void)
116	{
117	#ifdef CONFIG_HIGHMEM
118	struct zone *zone;
119	int res = 0;
120
121	pr_debug("swsusp: Saving Highmem\n");
122	for_each_zone (zone) {
123	if (is_highmem(zone))
124	res = save_highmem_zone(zone);
125	if (res)
126	return res;
127	}
128	#endif
129	return 0;
130	}
131
132	int restore_highmem(void)
133	{
134	#ifdef CONFIG_HIGHMEM
135	printk("swsusp: Restoring Highmem\n");
136	while (highmem_copy) {
137	struct highmem_page *save = highmem_copy;
138	void *kaddr;
139	highmem_copy = save->next;
140
141	kaddr = kmap_atomic(save->page, KM_USER0);
142	memcpy(kaddr, save->data, PAGE_SIZE);
143	kunmap_atomic(kaddr, KM_USER0);
144	free_page((long) save->data);
145	kfree(save);
146	}
147	#endif
148	return 0;
149	}
150
151
152	static int pfn_is_nosave(unsigned long pfn)
153	{
154	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
155	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
156	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
157	}
158
159	/**
160	* saveable - Determine whether a page should be cloned or not.
161	* @pfn: The page
162	*
163	* We save a page if it's Reserved, and not in the range of pages
164	* statically defined as 'unsaveable', or if it isn't reserved, and
165	* isn't part of a free chunk of pages.
166	*/
167
168	static int saveable(struct zone * zone, unsigned long * zone_pfn)
169	{
170	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
171	struct page * page;
172
173	if (!pfn_valid(pfn))
174	return 0;
175
176	page = pfn_to_page(pfn);
177	BUG_ON(PageReserved(page) && PageNosave(page));
178	if (PageNosave(page))
179	return 0;
180	if (PageReserved(page) && pfn_is_nosave(pfn)) {
181	pr_debug("[nosave pfn 0x%lx]", pfn);
182	return 0;
183	}
184	if (PageNosaveFree(page))
185	return 0;
186
187	return 1;
188	}
189
a0f49651	190	static unsigned count_data_pages(void)
25761b6e RW	191	{
	192	struct zone *zone;
	193	unsigned long zone_pfn;
a0f49651	194	unsigned n;
25761b6e	195
a0f49651	196	n = 0;
25761b6e RW	197	for_each_zone (zone) {
	198	if (is_highmem(zone))
	199	continue;
	200	mark_free_pages(zone);
	201	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
a0f49651	202	n += saveable(zone, &zone_pfn);
25761b6e	203	}
a0f49651	204	return n;
25761b6e RW	205	}
25761b6e RW	206
a0f49651	207	static void copy_data_pages(struct pbe *pblist)
25761b6e RW	208	{
	209	struct zone *zone;
	210	unsigned long zone_pfn;
a0f49651	211	struct pbe pbe, p;
25761b6e	212
a0f49651	213	pbe = pblist;
25761b6e RW	214	for_each_zone (zone) {
	215	if (is_highmem(zone))
	216	continue;
	217	mark_free_pages(zone);
	218	/* This is necessary for swsusp_free() */
a0f49651	219	for_each_pb_page (p, pblist)
25761b6e	220	SetPageNosaveFree(virt_to_page(p));
a0f49651	221	for_each_pbe (p, pblist)
25761b6e RW	222	SetPageNosaveFree(virt_to_page(p->address));
	223	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	224	if (saveable(zone, &zone_pfn)) {
	225	struct page * page;
	226	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	227	BUG_ON(!pbe);
	228	pbe->orig_address = (unsigned long)page_address(page);
	229	/* copy_page is not usable for copying task structs. */
	230	memcpy((void )pbe->address, (void )pbe->orig_address, PAGE_SIZE);
	231	pbe = pbe->next;
	232	}
	233	}
	234	}
	235	BUG_ON(pbe);
	236	}
	237
	238
	239	/**
	240	* free_pagedir - free pages allocated with alloc_pagedir()
	241	*/
	242
2c1b4a5c	243	static void free_pagedir(struct pbe *pblist)
25761b6e RW	244	{
	245	struct pbe *pbe;
	246
	247	while (pblist) {
	248	pbe = (pblist + PB_PAGE_SKIP)->next;
	249	ClearPageNosave(virt_to_page(pblist));
	250	ClearPageNosaveFree(virt_to_page(pblist));
	251	free_page((unsigned long)pblist);
	252	pblist = pbe;
	253	}
	254	}
	255
	256	/**
	257	* fill_pb_page - Create a list of PBEs on a given memory page
	258	*/
	259
	260	static inline void fill_pb_page(struct pbe *pbpage)
	261	{
	262	struct pbe *p;
	263
	264	p = pbpage;
	265	pbpage += PB_PAGE_SKIP;
	266	do
	267	p->next = p + 1;
	268	while (++p < pbpage);
	269	}
	270
	271	/**
	272	* create_pbe_list - Create a list of PBEs on top of a given chain
	273	* of memory pages allocated with alloc_pagedir()
	274	*/
	275
	276	void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
	277	{
	278	struct pbe pbpage, p;
	279	unsigned num = PBES_PER_PAGE;
	280
	281	for_each_pb_page (pbpage, pblist) {
	282	if (num >= nr_pages)
	283	break;
	284
	285	fill_pb_page(pbpage);
	286	num += PBES_PER_PAGE;
	287	}
	288	if (pbpage) {
	289	for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
	290	p->next = p + 1;
	291	p->next = NULL;
	292	}
	293	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
	294	}
	295
	296	static void *alloc_image_page(void)
	297	{
	298	void res = (void )get_zeroed_page(GFP_ATOMIC \| __GFP_COLD);
	299	if (res) {
	300	SetPageNosave(virt_to_page(res));
	301	SetPageNosaveFree(virt_to_page(res));
	302	}
	303	return res;
	304	}
	305
	306	/**
	307	* alloc_pagedir - Allocate the page directory.
308	*
309	* First, determine exactly how many pages we need and
310	* allocate them.
311	*
312	* We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
313	* struct pbe elements (pbes) and the last element in the page points
314	* to the next page.
315	*
316	* On each page we set up a list of struct_pbe elements.
317	*/
318
319	struct pbe * alloc_pagedir(unsigned nr_pages)
320	{
321	unsigned num;
322	struct pbe pblist, pbe;
323
324	if (!nr_pages)
325	return NULL;
326
327	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
328	pblist = (struct pbe *)alloc_image_page();
329	/* FIXME: rewrite this ugly loop */
330	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
331	pbe = pbe->next, num += PBES_PER_PAGE) {
332	pbe += PB_PAGE_SKIP;
333	pbe->next = (struct pbe *)alloc_image_page();
334	}
335	if (!pbe) { /* get_zeroed_page() failed */
336	free_pagedir(pblist);
337	pblist = NULL;
338	}
339	return pblist;
340	}
341
342	/**
343	* Free pages we allocated for suspend. Suspend pages are alocated
344	* before atomic copy, so we need to free them after resume.
345	*/
346
347	void swsusp_free(void)
348	{
349	struct zone *zone;
350	unsigned long zone_pfn;
351
352	for_each_zone(zone) {
353	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
354	if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
355	struct page * page;
356	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
357	if (PageNosave(page) && PageNosaveFree(page)) {
358	ClearPageNosave(page);
359	ClearPageNosaveFree(page);
360	free_page((long) page_address(page));
361	}
362	}
363	}
364	}
365
366
367	/**
368	* enough_free_mem - Make sure we enough free memory to snapshot.
369	*
370	* Returns TRUE or FALSE after checking the number of available
371	* free pages.
372	*/
373
a0f49651	374	static int enough_free_mem(unsigned nr_pages)
25761b6e RW	375	{
25761b6e RW	376	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
a0f49651 RW	377	return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
a0f49651 RW	378	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
25761b6e RW	379	}
	380
	381
a0f49651	382	static struct pbe *swsusp_alloc(unsigned nr_pages)
25761b6e	383	{
a0f49651	384	struct pbe pblist, p;
25761b6e	385
a0f49651	386	if (!(pblist = alloc_pagedir(nr_pages))) {
25761b6e	387	printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
a0f49651	388	return NULL;
25761b6e	389	}
a0f49651	390	create_pbe_list(pblist, nr_pages);
25761b6e	391
a0f49651	392	for_each_pbe (p, pblist) {
25761b6e RW	393	p->address = (unsigned long)alloc_image_page();
	394	if (!p->address) {
	395	printk(KERN_ERR "suspend: Allocating image pages failed.\n");
	396	swsusp_free();
a0f49651	397	return NULL;
25761b6e RW	398	}
	399	}
	400
a0f49651	401	return pblist;
25761b6e RW	402	}
	403
	404	static int suspend_prepare_image(void)
	405	{
a0f49651	406	unsigned nr_pages;
25761b6e RW	407
	408	pr_debug("swsusp: critical section: \n");
	409	if (save_highmem()) {
	410	printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
	411	restore_highmem();
	412	return -ENOMEM;
	413	}
	414
	415	drain_local_pages();
a0f49651 RW	416	nr_pages = count_data_pages();
a0f49651 RW	417	printk("swsusp: Need to copy %u pages\n", nr_pages);
25761b6e RW	418
25761b6e RW	419	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
a0f49651 RW	420	nr_pages,
a0f49651 RW	421	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
25761b6e RW	422	PAGES_FOR_IO, nr_free_pages());
25761b6e RW	423
a0f49651 RW	424	/* This is needed because of the fixed size of swsusp_info */
	425	if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
	426	return -ENOSPC;
	427
	428	if (!enough_free_mem(nr_pages)) {
25761b6e RW	429	printk(KERN_ERR "swsusp: Not enough free memory\n");
	430	return -ENOMEM;
	431	}
	432
a0f49651	433	if (!enough_swap(nr_pages)) {
25761b6e RW	434	printk(KERN_ERR "swsusp: Not enough free swap\n");
	435	return -ENOSPC;
	436	}
	437
a0f49651 RW	438	pagedir_nosave = swsusp_alloc(nr_pages);
	439	if (!pagedir_nosave)
	440	return -ENOMEM;
25761b6e RW	441
	442	/* During allocating of suspend pagedir, new cold pages may appear.
	443	* Kill them.
	444	*/
	445	drain_local_pages();
a0f49651	446	copy_data_pages(pagedir_nosave);
25761b6e RW	447
	448	/*
	449	* End of critical section. From now on, we can write to memory,
	450	* but we should not touch disk. This specially means we must _not_
	451	* touch swap space! Except we must write out our image of course.
	452	*/
	453
a0f49651 RW	454	nr_copy_pages = nr_pages;
	455
	456	printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
25761b6e RW	457	return 0;
	458	}
	459
	460
	461	asmlinkage int swsusp_save(void)
	462	{
	463	return suspend_prepare_image();
	464	}