x86/mm, hibernate: Do not assume the first e820 area to be RAM
In arch/x86/kernel/setup.c::trim_bios_range(), the codes
introduced by 1b5576e6 (base on d8a9e6a5), it updates the first
4Kb of memory to be E820_RESERVED region. That's because it's a
BIOS owned area but generally not listed in the E820 table:
e820: BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x0000000000096fff] usable
BIOS-e820: [mem 0x0000000000097000-0x0000000000097fff] reserved
...
e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
e820: remove [mem 0x000a0000-0x000fffff] usable
But the region of first 4Kb didn't register to nosave memory:
PM: Registered nosave memory: [mem 0x00097000-0x00097fff]
PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]
The code in e820_mark_nosave_regions() assumes the first e820
area to be RAM, so it causes the first 4Kb E820_RESERVED region
ignored when register to nosave. This patch removed assumption
of the first e820 area.
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <len.brown@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Link: http://lkml.kernel.org/r/1410491038-17576-1-git-send-email-jlee@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 988c00a..49f8864 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -682,15 +682,14 @@
* hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
*
* This function requires the e820 map to be sorted and without any
- * overlapping entries and assumes the first e820 area to be RAM.
+ * overlapping entries.
*/
void __init e820_mark_nosave_regions(unsigned long limit_pfn)
{
int i;
- unsigned long pfn;
+ unsigned long pfn = 0;
- pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
- for (i = 1; i < e820.nr_map; i++) {
+ for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
if (pfn < PFN_UP(ei->addr))
