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

	nr_copy_pages = 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)
			nr_copy_pages += saveable(zone, &zone_pfn);
	}
}

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

	pr_debug("copy_data_pages(): pages to copy: %d\n", nr_copy_pages);
	for_each_zone (zone) {
		if (is_highmem(zone))
			continue;
		mark_free_pages(zone);
		/* This is necessary for swsusp_free() */
		for_each_pb_page (p, pagedir_nosave)
			SetPageNosaveFree(virt_to_page(p));
		for_each_pbe(p, pagedir_nosave)
			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()
 */

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(void)
{
	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
	return nr_free_pages() > (nr_copy_pages + PAGES_FOR_IO +
		nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE));
}


static int swsusp_alloc(void)
{
	struct pbe * p;

	pagedir_nosave = NULL;

	if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
	    !!(nr_copy_pages % PBES_PER_PAGE))
		return -ENOSPC;

	if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
		printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
		return -ENOMEM;
	}
	create_pbe_list(pagedir_save, nr_copy_pages);
	pagedir_nosave = pagedir_save;

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

	return 0;
}

static int suspend_prepare_image(void)
{
	int error;

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

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

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

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

	error = swsusp_alloc();
	if (error)
		return error;

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

	/*
	 * 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.
	 */

	printk("swsusp: critical section/: done (%d pages copied)\n", nr_copy_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
190	static void count_data_pages(void)
191	{
192	struct zone *zone;
193	unsigned long zone_pfn;
194
195	nr_copy_pages = 0;
196
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)
202	nr_copy_pages += saveable(zone, &zone_pfn);
203	}
204	}
205
206	static void copy_data_pages(void)
207	{
208	struct zone *zone;
209	unsigned long zone_pfn;
210	struct pbe pbe = pagedir_nosave, p;
211
212	pr_debug("copy_data_pages(): pages to copy: %d\n", nr_copy_pages);
213	for_each_zone (zone) {
214	if (is_highmem(zone))
215	continue;
216	mark_free_pages(zone);
217	/* This is necessary for swsusp_free() */
218	for_each_pb_page (p, pagedir_nosave)
219	SetPageNosaveFree(virt_to_page(p));
220	for_each_pbe(p, pagedir_nosave)
221	SetPageNosaveFree(virt_to_page(p->address));
222	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
223	if (saveable(zone, &zone_pfn)) {
224	struct page * page;
225	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
226	BUG_ON(!pbe);
227	pbe->orig_address = (unsigned long)page_address(page);
228	/* copy_page is not usable for copying task structs. */
229	memcpy((void )pbe->address, (void )pbe->orig_address, PAGE_SIZE);
230	pbe = pbe->next;
231	}
232	}
233	}
234	BUG_ON(pbe);
235	}
236
237
238	/**
239	* free_pagedir - free pages allocated with alloc_pagedir()
240	*/
241
242	void free_pagedir(struct pbe *pblist)
243	{
244	struct pbe *pbe;
245
246	while (pblist) {
247	pbe = (pblist + PB_PAGE_SKIP)->next;
248	ClearPageNosave(virt_to_page(pblist));
249	ClearPageNosaveFree(virt_to_page(pblist));
250	free_page((unsigned long)pblist);
251	pblist = pbe;
252	}
253	}
254
255	/**
256	* fill_pb_page - Create a list of PBEs on a given memory page
257	*/
258
259	static inline void fill_pb_page(struct pbe *pbpage)
260	{
261	struct pbe *p;
262
263	p = pbpage;
264	pbpage += PB_PAGE_SKIP;
265	do
266	p->next = p + 1;
267	while (++p < pbpage);
268	}
269
270	/**
271	* create_pbe_list - Create a list of PBEs on top of a given chain
272	* of memory pages allocated with alloc_pagedir()
273	*/
274
275	void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
276	{
277	struct pbe pbpage, p;
278	unsigned num = PBES_PER_PAGE;
279
280	for_each_pb_page (pbpage, pblist) {
281	if (num >= nr_pages)
282	break;
283
284	fill_pb_page(pbpage);
285	num += PBES_PER_PAGE;
286	}
287	if (pbpage) {
288	for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
289	p->next = p + 1;
290	p->next = NULL;
291	}
292	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
293	}
294
295	static void *alloc_image_page(void)
296	{
297	void res = (void )get_zeroed_page(GFP_ATOMIC \| __GFP_COLD);
298	if (res) {
299	SetPageNosave(virt_to_page(res));
300	SetPageNosaveFree(virt_to_page(res));
301	}
302	return res;
303	}
304
305	/**
306	* alloc_pagedir - Allocate the page directory.
307	*
308	* First, determine exactly how many pages we need and
309	* allocate them.
310	*
311	* We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
312	* struct pbe elements (pbes) and the last element in the page points
313	* to the next page.
314	*
315	* On each page we set up a list of struct_pbe elements.
316	*/
317
318	struct pbe * alloc_pagedir(unsigned nr_pages)
319	{
320	unsigned num;
321	struct pbe pblist, pbe;
322
323	if (!nr_pages)
324	return NULL;
325
326	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
327	pblist = (struct pbe *)alloc_image_page();
328	/* FIXME: rewrite this ugly loop */
329	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
330	pbe = pbe->next, num += PBES_PER_PAGE) {
331	pbe += PB_PAGE_SKIP;
332	pbe->next = (struct pbe *)alloc_image_page();
333	}
334	if (!pbe) { /* get_zeroed_page() failed */
335	free_pagedir(pblist);
336	pblist = NULL;
337	}
338	return pblist;
339	}
340
341	/**
342	* Free pages we allocated for suspend. Suspend pages are alocated
343	* before atomic copy, so we need to free them after resume.
344	*/
345
346	void swsusp_free(void)
347	{
348	struct zone *zone;
349	unsigned long zone_pfn;
350
351	for_each_zone(zone) {
352	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
353	if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
354	struct page * page;
355	page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
356	if (PageNosave(page) && PageNosaveFree(page)) {
357	ClearPageNosave(page);
358	ClearPageNosaveFree(page);
359	free_page((long) page_address(page));
360	}
361	}
362	}
363	}
364
365
366	/**
367	* enough_free_mem - Make sure we enough free memory to snapshot.
368	*
369	* Returns TRUE or FALSE after checking the number of available
370	* free pages.
371	*/
372
373	static int enough_free_mem(void)
374	{
375	pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
376	return nr_free_pages() > (nr_copy_pages + PAGES_FOR_IO +
377	nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE));
378	}
379
380
381	static int swsusp_alloc(void)
382	{
383	struct pbe * p;
384
385	pagedir_nosave = NULL;
386
387	if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
388	!!(nr_copy_pages % PBES_PER_PAGE))
389	return -ENOSPC;
390
391	if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
392	printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
393	return -ENOMEM;
394	}
395	create_pbe_list(pagedir_save, nr_copy_pages);
396	pagedir_nosave = pagedir_save;
397
398	for_each_pbe (p, pagedir_save) {
399	p->address = (unsigned long)alloc_image_page();
400	if (!p->address) {
401	printk(KERN_ERR "suspend: Allocating image pages failed.\n");
402	swsusp_free();
403	return -ENOMEM;
404	}
405	}
406
407	return 0;
408	}
409
410	static int suspend_prepare_image(void)
411	{
412	int error;
413
414	pr_debug("swsusp: critical section: \n");
415	if (save_highmem()) {
416	printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
417	restore_highmem();
418	return -ENOMEM;
419	}
420
421	drain_local_pages();
422	count_data_pages();
423	printk("swsusp: Need to copy %u pages\n", nr_copy_pages);
424
425	pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
426	nr_copy_pages,
427	nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE),
428	PAGES_FOR_IO, nr_free_pages());
429
430	if (!enough_free_mem()) {
431	printk(KERN_ERR "swsusp: Not enough free memory\n");
432	return -ENOMEM;
433	}
434
435	if (!enough_swap()) {
436	printk(KERN_ERR "swsusp: Not enough free swap\n");
437	return -ENOSPC;
438	}
439
440	error = swsusp_alloc();
441	if (error)
442	return error;
443
444	/* During allocating of suspend pagedir, new cold pages may appear.
445	* Kill them.
446	*/
447	drain_local_pages();
448	copy_data_pages();
449
450	/*
451	* End of critical section. From now on, we can write to memory,
452	* but we should not touch disk. This specially means we must _not_
453	* touch swap space! Except we must write out our image of course.
454	*/
455
456	printk("swsusp: critical section/: done (%d pages copied)\n", nr_copy_pages );
457	return 0;
458	}
459
460
461	asmlinkage int swsusp_save(void)
462	{
463	return suspend_prepare_image();
464	}