--- f010ab424f1f9ccc03b3f8ed7b4e759609ef733a +++ 5fd5b07bf3a5774cd996e312d9fe55533a37b984 @@ -439,21 +439,39 @@ static int __cpuinit mwait_usable(const } /* - * Check for AMD CPUs, which have potentially C1E support + * Check for AMD CPUs, where APIC timer interrupt does not wake up CPU from C1e. + * For more information see + * - Erratum #400 for NPT family 0xf and family 0x10 CPUs + * - Erratum #365 for family 0x11 (not affected because C1e not in use) */ static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c) { + u64 val; if (c->x86_vendor != X86_VENDOR_AMD) - return 0; - - if (c->x86 < 0x0F) - return 0; + goto no_c1e_idle; /* Family 0x0f models < rev F do not have C1E */ - if (c->x86 == 0x0f && c->x86_model < 0x40) - return 0; + if (c->x86 == 0x0F && c->x86_model >= 0x40) + return 1; + + if (c->x86 == 0x10) { + /* + * check OSVW bit for CPUs that are not affected + * by erratum #400 + */ + if (cpu_has(c, X86_FEATURE_OSVW)) { + rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, val); + if (val >= 2) { + rdmsrl(MSR_AMD64_OSVW_STATUS, val); + if (!(val & BIT(1))) + goto no_c1e_idle; + } + } + return 1; + } - return 1; +no_c1e_idle: + return 0; } static cpumask_var_t c1e_mask;