i386: do not restore reserved memory after hibernation

On some systems the ACPI NVS area is located in the first 1 MB of RAM and
it is overwritten by the i386 code during the restore after hibernation.
This confuses the ACPI platform firmware that doesn't update the AC adapter
status appropriately as a result
(http://bugzilla.kernel.org/show_bug.cgi?id=7995).

The solution is to register the reserved memory in the first 1 MB as
'nosave', so that swsusp doesn't touch it during the restore.  Also, this
has been done on x86_64 for a long time now, so this patch makes the i386
restore code behave like the x86_64 one.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rafael J. Wysocki 2007-07-21 17:11:09 +02:00 committed by Linus Torvalds
parent 114ab8e99c
commit 1c10070a55
3 changed files with 41 additions and 0 deletions

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@ -10,6 +10,7 @@
#include <linux/efi.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
#include <linux/suspend.h>
#include <asm/pgtable.h>
#include <asm/page.h>
@ -320,6 +321,37 @@ static int __init request_standard_resources(void)
subsys_initcall(request_standard_resources);
#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND)
/**
* e820_mark_nosave_regions - Find the ranges of physical addresses that do not
* correspond to e820 RAM areas and mark the corresponding pages as nosave for
* hibernation.
*
* This function requires the e820 map to be sorted and without any
* overlapping entries and assumes the first e820 area to be RAM.
*/
void __init e820_mark_nosave_regions(void)
{
int i;
unsigned long pfn;
pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
for (i = 1; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
if (pfn < PFN_UP(ei->addr))
register_nosave_region(pfn, PFN_UP(ei->addr));
pfn = PFN_DOWN(ei->addr + ei->size);
if (ei->type != E820_RAM)
register_nosave_region(PFN_UP(ei->addr), pfn);
if (pfn >= max_low_pfn)
break;
}
}
#endif
void __init add_memory_region(unsigned long long start,
unsigned long long size, int type)
{

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@ -640,6 +640,7 @@ void __init setup_arch(char **cmdline_p)
#endif
e820_register_memory();
e820_mark_nosave_regions();
#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)

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@ -47,6 +47,14 @@ extern void e820_register_memory(void);
extern void limit_regions(unsigned long long size);
extern void print_memory_map(char *who);
#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND)
extern void e820_mark_nosave_regions(void);
#else
static inline void e820_mark_nosave_regions(void)
{
}
#endif
#endif/*!__ASSEMBLY__*/
#endif/*__E820_HEADER*/