Messages in this thread | | | Date | Wed, 22 Aug 2012 14:46:49 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86: mce: Honour bios-set CMCI threshold |
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On Wed, Aug 22, 2012 at 06:00:54PM +0530, Naveen N. Rao wrote: > The ACPI spec doesn't provide for a way for the bios to pass down > recommended thresholds to the OS on a _per-bank_ basis. This patch adds > a new boot option, which if passed, allows bios to initialize the CMCI > threshold. In such a case, we simply skip programming any threshold > value. > > As fail-safe, we initialize threshold to 1 if some banks have not been > initialized by the bios and warn the user. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > Documentation/x86/x86_64/boot-options.txt | 5 ++++ > arch/x86/include/asm/mce.h | 1 + > arch/x86/kernel/cpu/mcheck/mce.c | 4 +++ > arch/x86/kernel/cpu/mcheck/mce_intel.c | 39 +++++++++++++++++++++++++++-- > 4 files changed, 46 insertions(+), 3 deletions(-) > > diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt > index c54b4f5..ec92540 100644 > --- a/Documentation/x86/x86_64/boot-options.txt > +++ b/Documentation/x86/x86_64/boot-options.txt > @@ -50,6 +50,11 @@ Machine check > monarchtimeout: > Sets the time in us to wait for other CPUs on machine checks. 0 > to disable. > + mce=bios_cmci_threshold > + Don't overwrite the bios-set CMCI threshold. This boot option > + prevents Linux from overwriting the CMCI threshold set by the > + bios. Without this option, Linux always sets the CMCI > + threshold to 1. > > nomce (for compatibility with i386): same as mce=off > > diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h > index a3ac52b..8ad5078 100644 > --- a/arch/x86/include/asm/mce.h > +++ b/arch/x86/include/asm/mce.h > @@ -171,6 +171,7 @@ DECLARE_PER_CPU(struct device *, mce_device); > #ifdef CONFIG_X86_MCE_INTEL > extern int mce_cmci_disabled; > extern int mce_ignore_ce; > +extern int mce_bios_cmci_threshold; > void mce_intel_feature_init(struct cpuinfo_x86 *c); > void cmci_clear(void); > void cmci_reenable(void); > diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c > index 292d025..401359d 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce.c > +++ b/arch/x86/kernel/cpu/mcheck/mce.c > @@ -82,6 +82,7 @@ static int mce_panic_timeout __read_mostly; > static int mce_dont_log_ce __read_mostly; > int mce_cmci_disabled __read_mostly; > int mce_ignore_ce __read_mostly; > +int mce_bios_cmci_threshold __read_mostly; > int mce_ser __read_mostly;
AFAICT, this is actually a single-bit flag but we're using a whole integer for it and from looking at the other boot options a couple of them are used as flags too.
Care to define a
struct boot_flags { __u64 mce_bios_cmci_threshold : 1, __reserved : 63; };
and use
boot_flags.mce_bios_cmci_threshold
in the conditionals below instead?
I'll try to convert the rest of them to that struct and thus save some more space...
Thanks.
-- Regards/Gruss, Boris.
Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551
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