Initialization and handling for LMCE - boot time option to disable LMCE for that boot instance - Check for capability via IA32_MCG_CAP - provide ability to enable/disable LMCE on demand.
See http://www.intel.com/sdm Volume 3 System Programming Guide, Chapter 15 for more information on MSR's and documentation on Local MCE. Signed-off-by: Ashok Raj <ashok....@intel.com> --- Documentation/x86/x86_64/boot-options.txt | 3 ++ arch/x86/include/asm/mce.h | 5 +++ arch/x86/kernel/cpu/mcheck/mce.c | 3 ++ arch/x86/kernel/cpu/mcheck/mce_intel.c | 75 +++++++++++++++++++++++++++++++ 4 files changed, 86 insertions(+) diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index 5223479..79edee0 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -31,6 +31,9 @@ Machine check (e.g. BIOS or hardware monitoring applications), conflicting with OS's error handling, and you cannot deactivate the agent, then this option will be a help. + mce=no_lmce + Do not opt-in to Local MCE delivery. Use legacy method + to broadcast MCE's. mce=bootlog Enable logging of machine checks left over from booting. Disabled by default on AMD because some BIOS leave bogus ones. diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 677a408..8ba4d7a 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -109,6 +109,7 @@ struct mce_log { struct mca_config { bool dont_log_ce; bool cmci_disabled; + bool lmce_disabled; bool ignore_ce; bool disabled; bool ser; @@ -173,12 +174,16 @@ void cmci_clear(void); void cmci_reenable(void); void cmci_rediscover(void); void cmci_recheck(void); +void lmce_clear(void); +void lmce_enable(void); #else static inline void mce_intel_feature_init(struct cpuinfo_x86 *c) { } static inline void cmci_clear(void) {} static inline void cmci_reenable(void) {} static inline void cmci_rediscover(void) {} static inline void cmci_recheck(void) {} +static inline void lmce_clear(void) {} +static inline void lmce_enable(void) {} #endif #ifdef CONFIG_X86_MCE_AMD diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index e535533..d10aada 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1976,6 +1976,7 @@ void mce_disable_bank(int bank) /* * mce=off Disables machine check * mce=no_cmci Disables CMCI + * mce=no_lmce Disables LMCE * mce=dont_log_ce Clears corrected events silently, no log created for CEs. * mce=ignore_ce Disables polling and CMCI, corrected events are not cleared. * mce=TOLERANCELEVEL[,monarchtimeout] (number, see above) @@ -1999,6 +2000,8 @@ static int __init mcheck_enable(char *str) cfg->disabled = true; else if (!strcmp(str, "no_cmci")) cfg->cmci_disabled = true; + else if (!strcmp(str, "no_lmce")) + cfg->lmce_disabled = true; else if (!strcmp(str, "dont_log_ce")) cfg->dont_log_ce = true; else if (!strcmp(str, "ignore_ce")) diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c index b4a41cf..be3a5c6 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c @@ -70,6 +70,10 @@ enum { static atomic_t cmci_storm_on_cpus; +#define FEATURE_CONTROL_LMCE_BITS ((FEATURE_CONTROL_LOCKED) | \ + (FEATURE_CONTROL_LMCE_SUPPORT_ENABLED)) +#define MCG_CAP_LMCE_BITS ((MCG_SER_P) | (MCG_LMCE_P)) + static int cmci_supported(int *banks) { u64 cap; @@ -91,6 +95,34 @@ static int cmci_supported(int *banks) return !!(cap & MCG_CMCI_P); } +static bool lmce_supported(void) +{ + u64 cap, feature_ctl; + bool lmce_bios_support, retval; + + if (mca_cfg.lmce_disabled) + return false; + + rdmsrl(MSR_IA32_MCG_CAP, cap); + rdmsrl(MSR_IA32_FEATURE_CONTROL, feature_ctl); + + /* + * BIOS should indicate support for LMCE by setting + * bit20 in IA32_FEATURE_CONTROL. without which touching + * MCG_EXT_CTL will generate #GP fault. + */ + lmce_bios_support = ((feature_ctl & (FEATURE_CONTROL_LMCE_BITS)) == + (FEATURE_CONTROL_LMCE_BITS)); + + /* + * MCG_CAP should indicate both MCG_SER_P and MCG_LMCE_P + */ + cap = ((cap & MCG_CAP_LMCE_BITS) == (MCG_CAP_LMCE_BITS)); + retval = (cap && lmce_bios_support); + + return retval; +} + bool mce_intel_cmci_poll(void) { if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE) @@ -405,6 +437,49 @@ static void intel_init_cmci(void) cmci_recheck(); } +static void __lmce_enable(void) +{ + u64 val; + + rdmsrl(MSR_IA32_MCG_EXT_CTL, val); + val |= MCG_EXT_CTL_LMCE_EN; + wrmsrl(MSR_IA32_MCG_EXT_CTL, val); +} + + +void intel_init_lmce(void) +{ + if (!lmce_supported()) + return; + + __lmce_enable(); +} + +void lmce_enable(void) +{ + intel_init_lmce(); +} + +void lmce_disable(void) +{ + u64 val; + + rdmsrl(MSR_IA32_MCG_EXT_CTL, val); + val &= ~MCG_EXT_CTL_LMCE_EN; + wrmsrl(MSR_IA32_MCG_EXT_CTL, val); +} + +/* + * Disable LMCE on this CPU for all banks it owns when it goes down. + * This allows other CPUs to claim the banks on rediscovery. + */ +void lmce_clear(void) +{ + if (!lmce_supported()) + return; + lmce_disable(); +} + void mce_intel_feature_init(struct cpuinfo_x86 *c) { intel_init_thermal(c); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
