Messages in this thread | | | Date | Sun, 10 Dec 2017 17:18:24 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 2/2] x86/mce: Report only DRAM ECC as memory errors on AMD systems |
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On Thu, Dec 07, 2017 at 02:39:55PM -0600, Yazen Ghannam wrote: > From: Yazen Ghannam <yazen.ghannam@amd.com> > > The MCA_STATUS[ErrorCodeExt] field is very bank type specific. We currently > check if the ErrorCodeExt value is 0x0 or 0x8 in mce_is_memory_error(), but > we don't check the bank. This means that we could flag non-memory errors as > memory errors. > > We know that we want to flag DRAM ECC errors as memory errors, so let's do > those cases first. We can add more cases later when needed. > > Check that bank type is UMC and xec is 0 on SMCA systems. > > Check that bank is 4 (Northbridge) and xec is 8 on legacy systems. > > Define a wrapper function in mce_amd.c so we can use SMCA enums. > > Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> > --- > Link: > https://lkml.kernel.org/r/20171201155034.39206-2-Yazen.Ghannam@amd.com > > v1->v2: > * No changes. > > arch/x86/include/asm/mce.h | 2 ++ > arch/x86/kernel/cpu/mcheck/mce.c | 4 +--- > arch/x86/kernel/cpu/mcheck/mce_amd.c | 11 +++++++++++ > 3 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h > index b1e8d8db921f..96ea4b5ba658 100644 > --- a/arch/x86/include/asm/mce.h > +++ b/arch/x86/include/asm/mce.h > @@ -376,6 +376,7 @@ struct smca_bank { > extern struct smca_bank smca_banks[MAX_NR_BANKS]; > > extern const char *smca_get_long_name(enum smca_bank_types t); > +extern bool amd_mce_is_memory_error(struct mce *m); > > extern int mce_threshold_create_device(unsigned int cpu); > extern int mce_threshold_remove_device(unsigned int cpu); > @@ -384,6 +385,7 @@ extern int mce_threshold_remove_device(unsigned int cpu); > > static inline int mce_threshold_create_device(unsigned int cpu) { return 0; }; > static inline int mce_threshold_remove_device(unsigned int cpu) { return 0; }; > +static inline bool amd_mce_is_memory_error(struct mce *m) { return false; }; > > #endif > > diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c > index b1d616d08eee..321c7a80be66 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce.c > +++ b/arch/x86/kernel/cpu/mcheck/mce.c > @@ -503,10 +503,8 @@ static int mce_usable_address(struct mce *m) > bool mce_is_memory_error(struct mce *m) > { > if (m->cpuvendor == X86_VENDOR_AMD) { > - /* ErrCodeExt[20:16] */ > - u8 xec = (m->status >> 16) & 0x1f; > + return amd_mce_is_memory_error(m); > > - return (xec == 0x0 || xec == 0x8); > } else if (m->cpuvendor == X86_VENDOR_INTEL) { > /* > * Intel SDM Volume 3B - 15.9.2 Compound Error Codes > diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c > index 219d5115f4d4..2b7f7ce4bedf 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c > +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c > @@ -750,6 +750,17 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr) > } > EXPORT_SYMBOL_GPL(umc_normaddr_to_sysaddr); > > +bool amd_mce_is_memory_error(struct mce *m) > +{ > + /* ErrCodeExt[20:16] */ > + u8 xec = (m->status >> 16) & 0x1f; > + > + if (mce_flags.smca) > + return (smca_get_bank_type(m) == SMCA_UMC && xec == 0x0); > + > + return (m->bank == 4 && xec == 0x8);
You don't need brackets around the return statements.
Anyway, applied, thx.
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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