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Commit 1c10070a authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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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: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 114ab8e9

arch/i386/kernel/e820.c

+32 −0
Original line number Diff line number Diff line
@@ -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)

{

arch/i386/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

include/asm-i386/e820.h

+8 −0
Original line number Diff line number Diff line
@@ -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*/