Messages in this thread Patch in this message | | | From | "Lee, Chun-Yi" <> | Subject | [PATCH] Hibernate: Do not assume the first e820 area to be RAM | Date | Mon, 11 Aug 2014 18:50:52 +0800 |
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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
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