1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 70609efdf1da..b75f2569b8f8 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -227,6 +227,16 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
         if (cpu_has_bts)
                 ds_init_intel(c);
 
+        /*
+         * See if we have a good local APIC by checking for buggy Pentia,
+         * i.e. all B steppings and the C2 stepping of P54C when using their
+         * integrated APIC (see 11AP erratum in "Pentium Processor
+         * Specification Update").
+         */
+        if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
+            (c->x86_mask < 0x6 || c->x86_mask == 0xb))
+                set_cpu_cap(c, X86_FEATURE_11AP);
+
 #ifdef CONFIG_X86_NUMAQ
         numaq_tsc_disable();
 #endif