[PATCH v3 02/25] spinlock: Enable x86 architecture to do lockless refcount update

[Waiman Long <Waiman.Long@hp.com>]

There are two steps to enable each architecture to do lockless
reference count update:
1. Define the ARCH_SPINLOCK_REFCOUNT config parameter in its Kconfig
   file.
2. Add a <asm/spinlock_refcount.h> architecture specific header file.

This is done for the x86 architecture to use the generic version
available.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
---
 arch/x86/Kconfig                         |    3 +++
 arch/x86/include/asm/spinlock_refcount.h |    1 +
 2 files changed, 4 insertions(+), 0 deletions(-)
 create mode 100644 arch/x86/include/asm/spinlock_refcount.h

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe120da..649ed4b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -253,6 +253,9 @@ config ARCH_CPU_PROBE_RELEASE
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 
+config ARCH_SPINLOCK_REFCOUNT
+	def_bool y
+
 source "init/Kconfig"
 source "kernel/Kconfig.freezer"
 
diff --git a/arch/x86/include/asm/spinlock_refcount.h b/arch/x86/include/asm/spinlock_refcount.h
new file mode 100644
index 0000000..ab6224f
--- /dev/null
+++ b/arch/x86/include/asm/spinlock_refcount.h
@@ -0,0 +1 @@
+#include <asm-generic/spinlock_refcount.h>
-- 
1.7.1