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[PATCH] swsusp: reduce code duplication

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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: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Rafael J. Wysocki 2005-11-08 21:34:39 -08:00 committed by Linus Torvalds
parent a31751e04e
commit 054bd4c188
3 changed files with 52 additions and 70 deletions
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3
kernel/power/power.h
View file

@ -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);

62
kernel/power/snapshot.c
View file

@ -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);
@ -354,24 +380,32 @@ 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) {
printk(KERN_ERR "suspend: Allocating image pages failed.\n");
swsusp_free();
return NULL;
}
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;

57
kernel/power/swsusp.c
View file

@ -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);