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Commit ce4ab001 authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds
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[PATCH] swsusp: add architecture special saveable pages support 



1. Add architecture specific pages save/restore support.  Next two patches
   will use this to save/restore 'ACPI NVS' pages.

2. Allow reserved pages 'nosave'.  This could avoid save/restore BIOS
   reserved pages.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 82dcaafc

include/linux/suspend.h

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct saved_context; 
void __save_processor_state(struct saved_context *ctxt);

void __restore_processor_state(struct saved_context *ctxt);

unsigned long get_safe_page(gfp_t gfp_mask);

int swsusp_add_arch_pages(unsigned long start, unsigned long end);



/*

 * XXX: We try to keep some more pages free so that I/O operations succeed

kernel/power/power.h

+4 −0
Original line number Diff line number Diff line
@@ -105,6 +105,10 @@ extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits); 
extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);

extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);



extern unsigned int count_special_pages(void);

extern int save_special_mem(void);

extern int restore_special_mem(void);



extern int swsusp_check(void);

extern int swsusp_shrink_memory(void);

extern void swsusp_free(void);

kernel/power/snapshot.c

+109 −1
Original line number Diff line number Diff line
@@ -39,6 +39,88 @@ static unsigned int nr_copy_pages; 
static unsigned int nr_meta_pages;

static unsigned long *buffer;



struct arch_saveable_page {

	unsigned long start;

	unsigned long end;

	char *data;

	struct arch_saveable_page *next;

};

static struct arch_saveable_page *arch_pages;



int swsusp_add_arch_pages(unsigned long start, unsigned long end)

{

	struct arch_saveable_page *tmp;



	while (start < end) {

		tmp = kzalloc(sizeof(struct arch_saveable_page), GFP_KERNEL);

		if (!tmp)

			return -ENOMEM;

		tmp->start = start;

		tmp->end = ((start >> PAGE_SHIFT) + 1) << PAGE_SHIFT;

		if (tmp->end > end)

			tmp->end = end;

		tmp->next = arch_pages;

		start = tmp->end;

		arch_pages = tmp;

	}

	return 0;

}



static unsigned int count_arch_pages(void)

{

	unsigned int count = 0;

	struct arch_saveable_page *tmp = arch_pages;

	while (tmp) {

		count++;

		tmp = tmp->next;

	}

	return count;

}



static int save_arch_mem(void)

{

	char *kaddr;

	struct arch_saveable_page *tmp = arch_pages;

	int offset;



	pr_debug("swsusp: Saving arch specific memory");

	while (tmp) {

		tmp->data = (char *)__get_free_page(GFP_ATOMIC);

		if (!tmp->data)

			return -ENOMEM;

		offset = tmp->start - (tmp->start & PAGE_MASK);

		/* arch pages might haven't a 'struct page' */

		kaddr = kmap_atomic_pfn(tmp->start >> PAGE_SHIFT, KM_USER0);

		memcpy(tmp->data + offset, kaddr + offset,

			tmp->end - tmp->start);

		kunmap_atomic(kaddr, KM_USER0);



		tmp = tmp->next;

	}

	return 0;

}



static int restore_arch_mem(void)

{

	char *kaddr;

	struct arch_saveable_page *tmp = arch_pages;

	int offset;



	while (tmp) {

		if (!tmp->data)

			continue;

		offset = tmp->start - (tmp->start & PAGE_MASK);

		kaddr = kmap_atomic_pfn(tmp->start >> PAGE_SHIFT, KM_USER0);

		memcpy(kaddr + offset, tmp->data + offset,

			tmp->end - tmp->start);

		kunmap_atomic(kaddr, KM_USER0);

		free_page((long)tmp->data);

		tmp->data = NULL;

		tmp = tmp->next;

	}

	return 0;

}



#ifdef CONFIG_HIGHMEM

unsigned int count_highmem_pages(void)

{
@@ -150,8 +232,35 @@ int restore_highmem(void) 
	}

	return 0;

}

#else

static unsigned int count_highmem_pages(void) {return 0;}

static int save_highmem(void) {return 0;}

static int restore_highmem(void) {return 0;}

#endif



unsigned int count_special_pages(void)

{

	return count_arch_pages() + count_highmem_pages();

}



int save_special_mem(void)

{

	int ret;

	ret = save_arch_mem();

	if (!ret)

		ret = save_highmem();

	return ret;

}



int restore_special_mem(void)

{

	int ret;

	ret = restore_arch_mem();

	if (!ret)

		ret = restore_highmem();

	return ret;

}



static int pfn_is_nosave(unsigned long pfn)

{

	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
@@ -177,7 +286,6 @@ static int saveable(struct zone *zone, unsigned long *zone_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))

kernel/power/swsusp.c

+4 −14
Original line number Diff line number Diff line
@@ -62,16 +62,6 @@ unsigned long image_size = 500 * 1024 * 1024; 


int in_suspend __nosavedata = 0;



#ifdef CONFIG_HIGHMEM

unsigned int count_highmem_pages(void);

int save_highmem(void);

int restore_highmem(void);

#else

static int save_highmem(void) { return 0; }

static int restore_highmem(void) { return 0; }

static unsigned int count_highmem_pages(void) { return 0; }

#endif



/**

 *	The following functions are used for tracing the allocated

 *	swap pages, so that they can be freed in case of an error.
@@ -192,7 +182,7 @@ int swsusp_shrink_memory(void) 


	printk("Shrinking memory...  ");

	do {

		size = 2 * count_highmem_pages();

		size = 2 * count_special_pages();

		size += size / 50 + count_data_pages();

		size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE +

			PAGES_FOR_IO;
@@ -234,7 +224,7 @@ int swsusp_suspend(void) 
		goto Enable_irqs;

	}



	if ((error = save_highmem())) {

	if ((error = save_special_mem())) {

		printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");

		goto Restore_highmem;

	}
@@ -245,7 +235,7 @@ int swsusp_suspend(void) 
	/* Restore control flow magically appears here */

	restore_processor_state();

Restore_highmem:

	restore_highmem();

	restore_special_mem();

	device_power_up();

Enable_irqs:

	local_irq_enable();
@@ -271,7 +261,7 @@ int swsusp_resume(void) 
	 */

	swsusp_free();

	restore_processor_state();

	restore_highmem();

	restore_special_mem();

	touch_softlockup_watchdog();

	device_power_up();

	local_irq_enable();