[net-next-2.6.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;
}
#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	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"
	35
	36
25761b6e RW	37	#ifdef CONFIG_HIGHMEM
	38	struct highmem_page {
	39	char *data;
	40	struct page *page;
	41	struct highmem_page *next;
	42	};
	43
	44	static struct highmem_page *highmem_copy;
	45
	46	static int save_highmem_zone(struct zone *zone)
	47	{
	48	unsigned long zone_pfn;
	49	mark_free_pages(zone);
	50	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	51	struct page *page;
	52	struct highmem_page *save;
	53	void *kaddr;
	54	unsigned long pfn = zone_pfn + zone->zone_start_pfn;
	55
	56	if (!(pfn%1000))
	57	printk(".");
	58	if (!pfn_valid(pfn))
	59	continue;
	60	page = pfn_to_page(pfn);
	61	/*
	62	* This condition results from rvmalloc() sans vmalloc_32()
	63	* and architectural memory reservations. This should be
	64	* corrected eventually when the cases giving rise to this
	65	* are better understood.
	66	*/
	67	if (PageReserved(page)) {
	68	printk("highmem reserved page?!\n");
	69	continue;
	70	}
	71	BUG_ON(PageNosave(page));
	72	if (PageNosaveFree(page))
	73	continue;
	74	save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
	75	if (!save)
	76	return -ENOMEM;
	77	save->next = highmem_copy;
	78	save->page = page;
	79	save->data = (void *) get_zeroed_page(GFP_ATOMIC);
	80	if (!save->data) {
	81	kfree(save);
	82	return -ENOMEM;
	83	}
	84	kaddr = kmap_atomic(page, KM_USER0);
	85	memcpy(save->data, kaddr, PAGE_SIZE);
	86	kunmap_atomic(kaddr, KM_USER0);
	87	highmem_copy = save;
	88	}
	89	return 0;
	90	}
	91	#endif /* CONFIG_HIGHMEM */
	92
	93
	94	static int save_highmem(void)
	95	{
	96	#ifdef CONFIG_HIGHMEM
	97	struct zone *zone;
	98	int res = 0;
	99
	100	pr_debug("swsusp: Saving Highmem\n");
101	for_each_zone (zone) {
102	if (is_highmem(zone))
103	res = save_highmem_zone(zone);
104	if (res)
105	return res;
106	}
107	#endif
108	return 0;
109	}
110
111	int restore_highmem(void)
112	{
113	#ifdef CONFIG_HIGHMEM
114	printk("swsusp: Restoring Highmem\n");
115	while (highmem_copy) {
116	struct highmem_page *save = highmem_copy;
117	void *kaddr;
118	highmem_copy = save->next;
119
120	kaddr = kmap_atomic(save->page, KM_USER0);
121	memcpy(kaddr, save->data, PAGE_SIZE);
122	kunmap_atomic(kaddr, KM_USER0);
123	free_page((long) save->data);
124	kfree(save);
125	}
126	#endif
127	return 0;
128	}
129
130
131	static int pfn_is_nosave(unsigned long pfn)
132	{
133	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
134	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
135	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
136	}
137
138	/**
139	* saveable - Determine whether a page should be cloned or not.
140	* @pfn: The page
141	*
142	* We save a page if it's Reserved, and not in the range of pages
143	* statically defined as 'unsaveable', or if it isn't reserved, and
144	* isn't part of a free chunk of pages.
145	*/
146
147	static int saveable(struct zone * zone, unsigned long * zone_pfn)
148	{
149	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
150	struct page * page;
151
152	if (!pfn_valid(pfn))
153	return 0;
154
155	page = pfn_to_page(pfn);
156	BUG_ON(PageReserved(page) && PageNosave(page));
157	if (PageNosave(page))
158	return 0;
159	if (PageReserved(page) && pfn_is_nosave(pfn)) {
160	pr_debug("[nosave pfn 0x%lx]", pfn);
161	return 0;
162	}
163	if (PageNosaveFree(page))
164	return 0;
165
166	return 1;
167	}
168
a0f49651	169	static unsigned count_data_pages(void)
25761b6e RW	170	{
	171	struct zone *zone;
	172	unsigned long zone_pfn;
a0f49651	173	unsigned n;
25761b6e	174
a0f49651	175	n = 0;
25761b6e RW	176	for_each_zone (zone) {
	177	if (is_highmem(zone))
	178	continue;
	179	mark_free_pages(zone);
	180	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
a0f49651	181	n += saveable(zone, &zone_pfn);
25761b6e	182	}
a0f49651	183	return n;
25761b6e RW	184	}
25761b6e RW	185
a0f49651	186	static void copy_data_pages(struct pbe *pblist)
25761b6e RW	187	{
	188	struct zone *zone;
	189	unsigned long zone_pfn;
a0f49651	190	struct pbe pbe, p;
25761b6e	191
a0f49651	192	pbe = pblist;
25761b6e RW	193	for_each_zone (zone) {
	194	if (is_highmem(zone))
	195	continue;
	196	mark_free_pages(zone);
	197	/* This is necessary for swsusp_free() */
a0f49651	198	for_each_pb_page (p, pblist)
25761b6e	199	SetPageNosaveFree(virt_to_page(p));
a0f49651	200	for_each_pbe (p, pblist)
25761b6e RW	201	SetPageNosaveFree(virt_to_page(p->address));
	202	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
	203	if (saveable(zone, &zone_pfn)) {
	204	struct page * page;
	205	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
	206	BUG_ON(!pbe);
	207	pbe->orig_address = (unsigned long)page_address(page);
	208	/* copy_page is not usable for copying task structs. */
	209	memcpy((void )pbe->address, (void )pbe->orig_address, PAGE_SIZE);
	210	pbe = pbe->next;
	211	}
	212	}
	213	}
	214	BUG_ON(pbe);
	215	}
	216
	217
	218	/**
	219	* free_pagedir - free pages allocated with alloc_pagedir()
	220	*/
	221
2c1b4a5c	222	static void free_pagedir(struct pbe *pblist)
25761b6e RW	223	{
	224	struct pbe *pbe;
	225
	226	while (pblist) {
	227	pbe = (pblist + PB_PAGE_SKIP)->next;
	228	ClearPageNosave(virt_to_page(pblist));
	229	ClearPageNosaveFree(virt_to_page(pblist));
	230	free_page((unsigned long)pblist);
	231	pblist = pbe;
	232	}
	233	}
	234
	235	/**
	236	* fill_pb_page - Create a list of PBEs on a given memory page
	237	*/
	238
	239	static inline void fill_pb_page(struct pbe *pbpage)
	240	{
	241	struct pbe *p;
	242
	243	p = pbpage;
	244	pbpage += PB_PAGE_SKIP;
	245	do
	246	p->next = p + 1;
	247	while (++p < pbpage);
	248	}
	249
	250	/**
	251	* create_pbe_list - Create a list of PBEs on top of a given chain
	252	* of memory pages allocated with alloc_pagedir()
	253	*/
	254
	255	void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
	256	{
	257	struct pbe pbpage, p;
	258	unsigned num = PBES_PER_PAGE;
	259
	260	for_each_pb_page (pbpage, pblist) {
	261	if (num >= nr_pages)
	262	break;
	263
	264	fill_pb_page(pbpage);
	265	num += PBES_PER_PAGE;
	266	}
	267	if (pbpage) {
	268	for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
	269	p->next = p + 1;
	270	p->next = NULL;
	271	}
	272	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
	273	}
	274
	275	static void *alloc_image_page(void)
	276	{
	277	void res = (void )get_zeroed_page(GFP_ATOMIC \| __GFP_COLD);
	278	if (res) {
	279	SetPageNosave(virt_to_page(res));
	280	SetPageNosaveFree(virt_to_page(res));
	281	}
	282	return res;
	283	}
	284
	285	/**
	286	* alloc_pagedir - Allocate the page directory.
287	*
288	* First, determine exactly how many pages we need and
289	* allocate them.
290	*
291	* We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
292	* struct pbe elements (pbes) and the last element in the page points
293	* to the next page.
294	*
295	* On each page we set up a list of struct_pbe elements.
296	*/
297
298	struct pbe * alloc_pagedir(unsigned nr_pages)
299	{
300	unsigned num;
301	struct pbe pblist, pbe;
302
303	if (!nr_pages)
304	return NULL;
305
306	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
307	pblist = (struct pbe *)alloc_image_page();
308	/* FIXME: rewrite this ugly loop */
309	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
310	pbe = pbe->next, num += PBES_PER_PAGE) {
311	pbe += PB_PAGE_SKIP;
312	pbe->next = (struct pbe *)alloc_image_page();
313	}
314	if (!pbe) { /* get_zeroed_page() failed */
315	free_pagedir(pblist);
316	pblist = NULL;
317	}
318	return pblist;
319	}
320
321	/**
322	* Free pages we allocated for suspend. Suspend pages are alocated
323	* before atomic copy, so we need to free them after resume.
324	*/
325
326	void swsusp_free(void)
327	{
328	struct zone *zone;
329	unsigned long zone_pfn;
330
331	for_each_zone(zone) {
332	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
333	if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
334	struct page * page;
335	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
336	if (PageNosave(page) && PageNosaveFree(page)) {
337	ClearPageNosave(page);
338	ClearPageNosaveFree(page);
339	free_page((long) page_address(page));
340	}
341	}
342	}
343	}
344
345
346	/**
347	* enough_free_mem - Make sure we enough free memory to snapshot.
348	*
349	* Returns TRUE or FALSE after checking the number of available
350	* free pages.
351	*/
352
a0f49651	353	static int enough_free_mem(unsigned nr_pages)
25761b6e RW	354	{
25761b6e RW	355	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
a0f49651 RW	356	return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
a0f49651 RW	357	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
25761b6e RW	358	}
	359
	360
a0f49651	361	static struct pbe *swsusp_alloc(unsigned nr_pages)
25761b6e	362	{
a0f49651	363	struct pbe pblist, p;
25761b6e	364
a0f49651	365	if (!(pblist = alloc_pagedir(nr_pages))) {
25761b6e	366	printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
a0f49651	367	return NULL;
25761b6e	368	}
a0f49651	369	create_pbe_list(pblist, nr_pages);
25761b6e	370
a0f49651	371	for_each_pbe (p, pblist) {
25761b6e RW	372	p->address = (unsigned long)alloc_image_page();
	373	if (!p->address) {
	374	printk(KERN_ERR "suspend: Allocating image pages failed.\n");
	375	swsusp_free();
a0f49651	376	return NULL;
25761b6e RW	377	}
	378	}
	379
a0f49651	380	return pblist;
25761b6e RW	381	}
	382
	383	static int suspend_prepare_image(void)
	384	{
a0f49651	385	unsigned nr_pages;
25761b6e RW	386
	387	pr_debug("swsusp: critical section: \n");
	388	if (save_highmem()) {
	389	printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
	390	restore_highmem();
	391	return -ENOMEM;
	392	}
	393
	394	drain_local_pages();
a0f49651 RW	395	nr_pages = count_data_pages();
a0f49651 RW	396	printk("swsusp: Need to copy %u pages\n", nr_pages);
25761b6e RW	397
25761b6e RW	398	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
a0f49651 RW	399	nr_pages,
a0f49651 RW	400	(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
25761b6e RW	401	PAGES_FOR_IO, nr_free_pages());
25761b6e RW	402
a0f49651 RW	403	/* This is needed because of the fixed size of swsusp_info */
	404	if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
	405	return -ENOSPC;
	406
	407	if (!enough_free_mem(nr_pages)) {
25761b6e RW	408	printk(KERN_ERR "swsusp: Not enough free memory\n");
	409	return -ENOMEM;
	410	}
	411
a0f49651	412	if (!enough_swap(nr_pages)) {
25761b6e RW	413	printk(KERN_ERR "swsusp: Not enough free swap\n");
	414	return -ENOSPC;
	415	}
	416
a0f49651 RW	417	pagedir_nosave = swsusp_alloc(nr_pages);
	418	if (!pagedir_nosave)
	419	return -ENOMEM;
25761b6e RW	420
	421	/* During allocating of suspend pagedir, new cold pages may appear.
	422	* Kill them.
	423	*/
	424	drain_local_pages();
a0f49651	425	copy_data_pages(pagedir_nosave);
25761b6e RW	426
	427	/*
	428	* End of critical section. From now on, we can write to memory,
	429	* but we should not touch disk. This specially means we must _not_
	430	* touch swap space! Except we must write out our image of course.
	431	*/
	432
a0f49651 RW	433	nr_copy_pages = nr_pages;
	434
	435	printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
25761b6e RW	436	return 0;
	437	}
	438
	439
	440	asmlinkage int swsusp_save(void)
	441	{
	442	return suspend_prepare_image();
	443	}