Commit 054bd4c1 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

[PATCH] swsusp: reduce code duplication 



The changes made by this patch are necessary for the pagedir relocation
simplification in the next patch.  Additionally, these changes allow us to
drop check_pagedir() and make get_safe_page() be a one-line wrapper around
alloc_image_page() (get_safe_page() goes to snapshot.c, because
alloc_image_page() is static and it does not make sense to export it).

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a31751e0

kernel/power/power.h

+2 −1
Original line number Diff line number Diff line
@@ -66,7 +66,8 @@ extern asmlinkage int swsusp_arch_suspend(void); 
extern asmlinkage int swsusp_arch_resume(void);



extern int restore_highmem(void);

extern struct pbe * alloc_pagedir(unsigned nr_pages);

extern struct pbe *alloc_pagedir(unsigned nr_pages, gfp_t gfp_mask, int safe_needed);

extern void create_pbe_list(struct pbe *pblist, unsigned nr_pages);

extern void swsusp_free(void);

extern int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed);

extern int enough_swap(unsigned nr_pages);

kernel/power/snapshot.c

+48 −14
Original line number Diff line number Diff line
@@ -269,9 +269,30 @@ void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) 
	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);

}



static void *alloc_image_page(void)

/**

 *	@safe_needed - on resume, for storing the PBE list and the image,

 *	we can only use memory pages that do not conflict with the pages

 *	which had been used before suspend.

 *

 *	The unsafe pages are marked with the PG_nosave_free flag

 *

 *	Allocated but unusable (ie eaten) memory pages should be marked

 *	so that swsusp_free() can release them

 */



static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)

{

	void *res = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);

	void *res;



	if (safe_needed)

		do {

			res = (void *)get_zeroed_page(gfp_mask);

			if (res && PageNosaveFree(virt_to_page(res)))

				/* This is for swsusp_free() */

				SetPageNosave(virt_to_page(res));

		} while (res && PageNosaveFree(virt_to_page(res)));

	else

		res = (void *)get_zeroed_page(gfp_mask);

	if (res) {

		SetPageNosave(virt_to_page(res));

		SetPageNosaveFree(virt_to_page(res));
@@ -279,6 +300,11 @@ static void *alloc_image_page(void) 
	return res;

}



unsigned long get_safe_page(gfp_t gfp_mask)

{

	return (unsigned long)alloc_image_page(gfp_mask, 1);

}



/**

 *	alloc_pagedir - Allocate the page directory.

 *
@@ -292,7 +318,7 @@ static void *alloc_image_page(void) 
 *	On each page we set up a list of struct_pbe elements.

 */



struct pbe *alloc_pagedir(unsigned int nr_pages)

struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed)

{

	unsigned int num;

	struct pbe *pblist, *pbe;
@@ -301,12 +327,12 @@ struct pbe *alloc_pagedir(unsigned int nr_pages) 
		return NULL;



	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);

	pblist = alloc_image_page();

	pblist = alloc_image_page(gfp_mask, safe_needed);

	/* 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();

		pbe->next = alloc_image_page(gfp_mask, safe_needed);

	}

	if (!pbe) { /* get_zeroed_page() failed */

		free_pagedir(pblist);
@@ -354,25 +380,33 @@ static int enough_free_mem(unsigned int nr_pages) 
		(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);

}



int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed)

{

	struct pbe *p;



	for_each_pbe (p, pblist) {

		p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed);

		if (!p->address)

			return -ENOMEM;

	}

	return 0;

}



static struct pbe *swsusp_alloc(unsigned int nr_pages)

{

	struct pbe *pblist, *p;

	struct pbe *pblist;



	if (!(pblist = alloc_pagedir(nr_pages))) {

	if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) {

		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) {

	if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) {

		printk(KERN_ERR "suspend: Allocating image pages failed.\n");

		swsusp_free();

		return NULL;

	}

	}



	return pblist;

}

kernel/power/swsusp.c

+2 −55
Original line number Diff line number Diff line
@@ -628,59 +628,6 @@ int swsusp_resume(void) 
	return error;

}



/**

 *	On resume, for storing the PBE list and the image,

 *	we can only use memory pages that do not conflict with the pages

 *	which had been used before suspend.

 *

 *	We don't know which pages are usable until we allocate them.

 *

 *	Allocated but unusable (ie eaten) memory pages are marked so that

 *	swsusp_free() can release them

 */



unsigned long get_safe_page(gfp_t gfp_mask)

{

	unsigned long m;



	do {

		m = get_zeroed_page(gfp_mask);

		if (m && PageNosaveFree(virt_to_page(m)))

			/* This is for swsusp_free() */

			SetPageNosave(virt_to_page(m));

	} while (m && PageNosaveFree(virt_to_page(m)));

	if (m) {

		/* This is for swsusp_free() */

		SetPageNosave(virt_to_page(m));

		SetPageNosaveFree(virt_to_page(m));

	}

	return m;

}



/**

 *	check_pagedir - We ensure here that pages that the PBEs point to

 *	won't collide with pages where we're going to restore from the loaded

 *	pages later

 */



static int check_pagedir(struct pbe *pblist)

{

	struct pbe *p;



	/* This is necessary, so that we can free allocated pages

	 * in case of failure

	 */

	for_each_pbe (p, pblist)

		p->address = 0UL;



	for_each_pbe (p, pblist) {

		p->address = get_safe_page(GFP_ATOMIC);

		if (!p->address)

			return -ENOMEM;

	}

	return 0;

}



/**

 *	swsusp_pagedir_relocate - It is possible, that some memory pages

 *	occupied by the list of PBEs collide with pages where we're going to
@@ -990,7 +937,7 @@ static int read_suspend_image(void) 
	int error = 0;

	struct pbe *p;



	if (!(p = alloc_pagedir(nr_copy_pages)))

	if (!(p = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 0)))

		return -ENOMEM;



	if ((error = read_pagedir(p)))
@@ -1003,7 +950,7 @@ static int read_suspend_image(void) 


	/* Allocate memory for the image and read the data from swap */



	error = check_pagedir(pagedir_nosave);

	error = alloc_data_pages(pagedir_nosave, GFP_ATOMIC, 1);



	if (!error)

		error = data_read(pagedir_nosave);

CRA Git | Maintained and supported by SUSTech CRA and CCSE