x86: this_cpu_cmpxchg and this_cpu_xchg operations

Provide support as far as the hardware capabilities of the x86 cpus
allow.

Define CONFIG_CMPXCHG_LOCAL in Kconfig.cpu to allow core code to test for
fast cpuops implementations.

V1->V2:
	- Take out the definition for this_cpu_cmpxchg_8 and move it into
	  a separate patch.

tj: - Reordered ops to better follow this_cpu_* organization.
    - Renamed macro temp variables similar to their existing
      neighbours.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 2ac9069890cd..15588a0ef466 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -310,6 +310,9 @@ config X86_INTERNODE_CACHE_SHIFT
 config X86_CMPXCHG
         def_bool X86_64 || (X86_32 && !M386)
 
+config CMPXCHG_LOCAL
+        def_bool X86_64 || (X86_32 && !M386)
+
 config X86_L1_CACHE_SHIFT
         int
         default "7" if MPENTIUM4 || MPSC