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>
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index fc822a4..e60cddb 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -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 @@
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)
{
diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index ec4dfcc..2986b48 100644
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -640,6 +640,7 @@
#endif
e820_register_memory();
+ e820_mark_nosave_regions();
#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
diff --git a/include/asm-i386/e820.h b/include/asm-i386/e820.h
index c03290c..43114c8 100644
--- a/include/asm-i386/e820.h
+++ b/include/asm-i386/e820.h
@@ -47,6 +47,14 @@
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*/