Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] Hibernate: Do not assume the first e820 area to be RAM | Date | Tue, 09 Sep 2014 00:52:55 +0200 |
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On Monday, August 11, 2014 06:50:52 PM Lee, Chun-Yi wrote: > 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>
Thomas, Ingo, Peter, any objections here?
If not, do you want to handle it or do you want me to do that?
> --- > 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); >
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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