1 files changed, 25 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 25c559ba8d54..191117f1ad51 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -13,6 +13,7 @@
 #include <asm/uaccess.h>
 #include <asm/ds.h>
 #include <asm/bugs.h>
+#include <asm/cpu.h>
 
 #ifdef CONFIG_X86_64
 #include <asm/topology.h>
@@ -110,6 +111,28 @@ static void __cpuinit trap_init_f00f_bug(void)
 }
 #endif
 
+static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+        /* calling is from identify_secondary_cpu() ? */
+        if (c->cpu_index == boot_cpu_id)
+                return;
+
+        /*
+         * Mask B, Pentium, but not Pentium MMX
+         */
+        if (c->x86 == 5 &&
+            c->x86_mask >= 1 && c->x86_mask <= 4 &&
+            c->x86_model <= 3) {
+                /*
+                 * Remember we have B step Pentia with bugs
+                 */
+                WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
+                                    "with B stepping processors.\n");
+        }
+#endif
+}
+
 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 {
         unsigned long lo, hi;
@@ -186,6 +209,8 @@ static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 #ifdef CONFIG_X86_NUMAQ
         numaq_tsc_disable();
 #endif
+
+        intel_smp_check(c);
 }
 #else
 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)