static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
+ /* Unmask CPUID levels if masked: */
+ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
+ u64 misc_enable;
+
+ rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+
+ if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
+ misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
+ wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+ c->cpuid_level = cpuid_eax(0);
+ }
+ }
+
if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
(c->x86 == 0x6 && c->x86_model >= 0x0e))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
}
+ /*
+ * There is a known erratum on Pentium III and Core Solo
+ * and Core Duo CPUs.
+ * " Page with PAT set to WC while associated MTRR is UC
+ * may consolidate to UC "
+ * Because of this erratum, it is better to stick with
+ * setting WC in MTRR rather than using PAT on these CPUs.
+ *
+ * Enable PAT WC only on P4, Core 2 or later CPUs.
+ */
+ if (c->x86 == 6 && c->x86_model < 15)
+ clear_cpu_cap(c, X86_FEATURE_PAT);
}
#ifdef CONFIG_X86_32