Revert "x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium"

This reverts commit 75eda5bcd238b96b7c63200bbfa7cbe06f84d2f6.

As Linus said in 24e1723366a: "There was something really messy about
cmpxchg8b and clone CPU's, so if you enable it on other CPUs later, do it
carefully."

This breaks lguest for those configs, but we can fix that by emulating
if we have to.

Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=14884
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <201001051248.49700.rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 08e442bc3ab914951a4faa4c29c616f7018b0cf7..f20ddf84a89397c322d4f35657400d5590891832 100644 (file)
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -396,7 +396,7 @@ config X86_TSC
 
 config X86_CMPXCHG64
        def_bool y
-       depends on !M386 && !M486
+       depends on X86_PAE || X86_64 || MCORE2 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MATOM
 
 # this should be set for all -march=.. options where the compiler
 # generates cmov.