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>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-i386/e820.h b/include/asm-i386/e820.h
index c03290ccecb2..43114c824608 100644
--- a/include/asm-i386/e820.h
+++ b/include/asm-i386/e820.h
@@ -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*/