All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] Hibernate: Do not assume the first e820 area to be RAM
@ 2014-08-11 10:50 Lee, Chun-Yi
  2014-08-12  9:35 ` Pavel Machek
  2014-09-08 22:52 ` Rafael J. Wysocki
  0 siblings, 2 replies; 6+ messages in thread
From: Lee, Chun-Yi @ 2014-08-11 10:50 UTC (permalink / raw)
  To: Rafael J. Wysocki, Len Brown, Pavel Machek
  Cc: Takashi Iwai, linux-pm, linux-kernel, Lee, Chun-Yi,
	Thomas Gleixner, Ingo Molnar, H. Peter Anvin

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:

[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000096fff] usable
[    0.000000] BIOS-e820: [mem 0x0000000000097000-0x0000000000097fff] reserved
...
[    0.000000] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[    0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable

But the region of first 4Kb didn't register to nosave memory:

[    0.000000] PM: Registered nosave memory: [mem 0x00097000-0x00097fff]
[    0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]

The codes 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.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 arch/x86/kernel/e820.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 988c00a..d595240 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -682,18 +682,17 @@ void __init parse_e820_ext(u64 phys_addr, u32 data_len)
  * 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;
 
-	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))
+		if (i > 0 && pfn < PFN_UP(ei->addr))
 			register_nosave_region(pfn, PFN_UP(ei->addr));
 
 		pfn = PFN_DOWN(ei->addr + ei->size);
-- 
1.8.4.5


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-09-10 13:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-11 10:50 [PATCH] Hibernate: Do not assume the first e820 area to be RAM Lee, Chun-Yi
2014-08-12  9:35 ` Pavel Machek
2014-09-08 22:52 ` Rafael J. Wysocki
2014-09-09  7:18   ` Pavel Machek
2014-09-10  6:08   ` Yinghai Lu
2014-09-10 13:43     ` joeyli

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.