X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Fcpu%2Fintel.c;h=1366c7cfd4831b12d1b229ad41b1651f97e50312;hp=7e1cca13af3589a562d26c0ead4a2a3c1474c129;hb=b18262eda36e1f340e3c29a8da9a36b3452621f9;hpb=a818d8e43147f40864363456b37a00b819439307

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 7e1cca13af35..1366c7cfd483 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