diff options
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 7e1cca13af3..1366c7cfd48 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -47,6 +47,27 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + /* + * Atom erratum AAE44/AAF40/AAG38/AAH41: + * + * A race condition between speculative fetches and invalidating + * a large page. This is worked around in microcode, but we + * need the microcode to have already been loaded... so if it is + * not, recommend a BIOS update and disable large pages. + */ + if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2) { + u32 ucode, junk; + + wrmsr(MSR_IA32_UCODE_REV, 0, 0); + sync_core(); + rdmsr(MSR_IA32_UCODE_REV, junk, ucode); + + if (ucode < 0x20e) { + printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n"); + clear_cpu_cap(c, X86_FEATURE_PSE); + } + } + #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSENTER32); #else |