1 files changed, 76 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/cmpxchg.h b/arch/alpha/include/asm/cmpxchg.h
new file mode 100644
index 000000000..6c7c39452
--- /dev/null
+++ b/arch/alpha/include/asm/cmpxchg.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ALPHA_CMPXCHG_H
+#define _ALPHA_CMPXCHG_H
+
+/*
+ * Atomic exchange routines.
+ */
+
+#define ____xchg(type, args...)		__xchg ## type ## _local(args)
+#define ____cmpxchg(type, args...)	__cmpxchg ## type ## _local(args)
+#include <asm/xchg.h>
+
+#define xchg_local(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg_local((ptr), (unsigned long)_x_,	\
+				       sizeof(*(ptr)));			\
+})
+
+#define cmpxchg_local(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,	\
+					  (unsigned long)_n_,		\
+					  sizeof(*(ptr)));		\
+})
+
+#define cmpxchg64_local(ptr, o, n)					\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_local((ptr), (o), (n));					\
+})
+
+#undef ____xchg
+#undef ____cmpxchg
+#define ____xchg(type, args...)		__xchg ##type(args)
+#define ____cmpxchg(type, args...)	__cmpxchg ##type(args)
+#include <asm/xchg.h>
+
+/*
+ * The leading and the trailing memory barriers guarantee that these
+ * operations are fully ordered.
+ */
+#define xchg(ptr, x)							\
+({									\
+	__typeof__(*(ptr)) __ret;					\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	smp_mb();							\
+	__ret = (__typeof__(*(ptr)))					\
+		__xchg((ptr), (unsigned long)_x_, sizeof(*(ptr)));	\
+	smp_mb();							\
+	__ret;								\
+})
+
+#define cmpxchg(ptr, o, n)						\
+({									\
+	__typeof__(*(ptr)) __ret;					\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	smp_mb();							\
+	__ret = (__typeof__(*(ptr))) __cmpxchg((ptr),			\
+		(unsigned long)_o_, (unsigned long)_n_, sizeof(*(ptr)));\
+	smp_mb();							\
+	__ret;								\
+})
+
+#define cmpxchg64(ptr, o, n)						\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg((ptr), (o), (n));					\
+})
+
+#undef ____cmpxchg
+
+#endif /* _ALPHA_CMPXCHG_H */