--- arch/x86/kernel/cpu/intel.c

+++ arch/x86/kernel/cpu/intel.c

@@ -47,6 +47,27 @@ static void __cpuinit early_init_intel(s

(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

@@ -70,7 +91,8 @@ static void __cpuinit early_init_intel(s

if (c->x86_power & (1 << 8)) {

set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);

- sched_clock_stable = 1;

+ if (!check_tsc_unstable())

+ sched_clock_stable = 1;

}

/*