From: Aravind Gopalakrishnan <[email protected]> For upcoming processors with Scalable MCA feature, we need to check the "succor" CPUID bit and the TCC bit in the MCx_STATUS register in order to grade an MCE's severity.
Signed-off-by: Aravind Gopalakrishnan <[email protected]> Cc: Aravind Gopalakrishnan <[email protected]> Cc: Tony Luck <[email protected]> Cc: linux-edac <[email protected]> Cc: x86-ml <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Yazen Ghannam <[email protected]> [ Simplify code flow, shorten comments. ] Signed-off-by: Borislav Petkov <[email protected]> --- arch/x86/kernel/cpu/mcheck/mce-severity.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c index 5119766d9889..631356c8cca4 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -204,6 +204,33 @@ static int error_context(struct mce *m) return IN_KERNEL; } +static int mce_severity_amd_smca(struct mce *m, int err_ctx) +{ + u32 addr = MSR_AMD64_SMCA_MCx_CONFIG(m->bank); + u32 low, high; + + /* + * We need to look at the following bits: + * - "succor" bit (data poisoning support), and + * - TCC bit (Task Context Corrupt) + * in MCi_STATUS to determine error severity. + */ + if (!mce_flags.succor) + return MCE_PANIC_SEVERITY; + + if (rdmsr_safe(addr, &low, &high)) + return MCE_PANIC_SEVERITY; + + /* TCC (Task context corrupt). If set and if IN_KERNEL, panic. */ + if ((low & MCI_CONFIG_MCAX) && + (m->status & MCI_STATUS_TCC) && + (err_ctx == IN_KERNEL)) + return MCE_PANIC_SEVERITY; + + /* ...otherwise invoke hwpoison handler. */ + return MCE_AR_SEVERITY; +} + /* * See AMD Error Scope Hierarchy table in a newer BKDG. For example * 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features" @@ -225,6 +252,9 @@ static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_exc * to at least kill process to prolong system operation. */ if (mce_flags.overflow_recov) { + if (mce_flags.smca) + return mce_severity_amd_smca(m, ctx); + /* software can try to contain */ if (!(m->mcgstatus & MCG_STATUS_RIPV) && (ctx == IN_KERNEL)) return MCE_PANIC_SEVERITY; -- 2.7.3
