diff options
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 32 |
2 files changed, 26 insertions, 8 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 1cd58cdbc03..4604e6a54d3 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -105,6 +105,8 @@ #define MSR_AMD64_PATCH_LEVEL 0x0000008b #define MSR_AMD64_NB_CFG 0xc001001f #define MSR_AMD64_PATCH_LOADER 0xc0010020 +#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140 +#define MSR_AMD64_OSVW_STATUS 0xc0010141 #define MSR_AMD64_IBSFETCHCTL 0xc0011030 #define MSR_AMD64_IBSFETCHLINAD 0xc0011031 #define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032 diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ad9540676fc..28ad9f4d8b9 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -526,21 +526,37 @@ static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) } /* - * 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; - return 1; + if (c->x86 == 0x10) { + /* + * check OSVW bit for CPUs that are not affected + * by erratum #400 + */ + 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; + } + +no_c1e_idle: + return 0; } static cpumask_var_t c1e_mask; |