diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r-- | arch/x86/kernel/process.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ad9540676fcc..28ad9f4d8b94 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) | |||
526 | } | 526 | } |
527 | 527 | ||
528 | /* | 528 | /* |
529 | * Check for AMD CPUs, which have potentially C1E support | 529 | * Check for AMD CPUs, where APIC timer interrupt does not wake up CPU from C1e. |
530 | * For more information see | ||
531 | * - Erratum #400 for NPT family 0xf and family 0x10 CPUs | ||
532 | * - Erratum #365 for family 0x11 (not affected because C1e not in use) | ||
530 | */ | 533 | */ |
531 | static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c) | 534 | static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c) |
532 | { | 535 | { |
536 | u64 val; | ||
533 | if (c->x86_vendor != X86_VENDOR_AMD) | 537 | if (c->x86_vendor != X86_VENDOR_AMD) |
534 | return 0; | 538 | goto no_c1e_idle; |
535 | |||
536 | if (c->x86 < 0x0F) | ||
537 | return 0; | ||
538 | 539 | ||
539 | /* Family 0x0f models < rev F do not have C1E */ | 540 | /* Family 0x0f models < rev F do not have C1E */ |
540 | if (c->x86 == 0x0f && c->x86_model < 0x40) | 541 | if (c->x86 == 0x0F && c->x86_model >= 0x40) |
541 | return 0; | 542 | return 1; |
542 | 543 | ||
543 | return 1; | 544 | if (c->x86 == 0x10) { |
545 | /* | ||
546 | * check OSVW bit for CPUs that are not affected | ||
547 | * by erratum #400 | ||
548 | */ | ||
549 | rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, val); | ||
550 | if (val >= 2) { | ||
551 | rdmsrl(MSR_AMD64_OSVW_STATUS, val); | ||
552 | if (!(val & BIT(1))) | ||
553 | goto no_c1e_idle; | ||
554 | } | ||
555 | return 1; | ||
556 | } | ||
557 | |||
558 | no_c1e_idle: | ||
559 | return 0; | ||
544 | } | 560 | } |
545 | 561 | ||
546 | static cpumask_var_t c1e_mask; | 562 | static cpumask_var_t c1e_mask; |