2 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 2ad6301849a1..3d22bb8175b4 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -399,6 +399,10 @@ config X86_TSC
         def_bool y
         depends on ((MWINCHIP3D || MWINCHIP2 || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2 || MVIAC7 || MGEODEGX1 || MGEODE_LX || MCORE2) && !X86_NUMAQ) || X86_64
 
+config X86_CMPXCHG64
+        def_bool y
+        depends on X86_PAE || X86_64
+
 # this should be set for all -march=.. options where the compiler
 # generates cmov.
 config X86_CMOV
diff --git a/include/asm-x86/required-features.h b/include/asm-x86/required-features.h
index 7400d3ad75c6..8c387198ca88 100644
--- a/include/asm-x86/required-features.h
+++ b/include/asm-x86/required-features.h
@@ -19,9 +19,13 @@
 
 #if defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
 # define NEED_PAE       (1<<(X86_FEATURE_PAE & 31))
-# define NEED_CX8       (1<<(X86_FEATURE_CX8 & 31))
 #else
 # define NEED_PAE       0
+#endif
+
+#ifdef CONFIG_X86_CMPXCHG64
+# define NEED_CX8       (1<<(X86_FEATURE_CX8 & 31))
+#else
 # define NEED_CX8       0
 #endif