diff --git a/xen/arch/riscv/include/asm/cmpxchg.h b/xen/arch/riscv/include/asm/cmpxchg.h
new file mode 100644
index 0000000000..8660ecd287
--- /dev/null
+++ b/xen/arch/riscv/include/asm/cmpxchg.h
@@ -0,0 +1,373 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2014 Regents of the University of California */
+
+#ifndef _ASM_RISCV_CMPXCHG_H
+#define _ASM_RISCV_CMPXCHG_H
+
+#include <asm/system.h>
+#include <asm/fence.h>
+#include <xen/lib.h>
+
+#define __xchg_relaxed(ptr, new, size)					\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(new) __new = (new);					\
+	__typeof__(*(ptr)) __ret;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.w %0, %2, %1\n"			\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.d %0, %2, %1\n"			\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define xchg_relaxed(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg_relaxed((ptr),			\
+					    _x_, sizeof(*(ptr)));	\
+})
+
+#define __xchg_acquire(ptr, new, size)					\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(new) __new = (new);					\
+	__typeof__(*(ptr)) __ret;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.w %0, %2, %1\n"			\
+			RISCV_ACQUIRE_BARRIER				\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.d %0, %2, %1\n"			\
+			RISCV_ACQUIRE_BARRIER				\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define xchg_acquire(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg_acquire((ptr),			\
+					    _x_, sizeof(*(ptr)));	\
+})
+
+#define __xchg_release(ptr, new, size)					\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(new) __new = (new);					\
+	__typeof__(*(ptr)) __ret;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			RISCV_RELEASE_BARRIER				\
+			"	amoswap.w %0, %2, %1\n"			\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			RISCV_RELEASE_BARRIER				\
+			"	amoswap.d %0, %2, %1\n"			\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define xchg_release(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg_release((ptr),			\
+					    _x_, sizeof(*(ptr)));	\
+})
+
+#define __xchg(ptr, new, size)						\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(new) __new = (new);					\
+	__typeof__(*(ptr)) __ret;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.w.aqrl %0, %2, %1\n"		\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"	amoswap.d.aqrl %0, %2, %1\n"		\
+			: "=r" (__ret), "+A" (*__ptr)			\
+			: "r" (__new)					\
+			: "memory");					\
+		break;							\
+	default:							\
+		__ret = 0; \
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define xchg(ptr, x)							\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr)));	\
+})
+
+#define xchg32(ptr, x)							\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
+	xchg((ptr), (x));						\
+})
+
+#define xchg64(ptr, x)							\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	xchg((ptr), (x));						\
+})
+
+/*
+ * Atomic compare and exchange.  Compare OLD with MEM, if identical,
+ * store NEW in MEM.  Return the initial value in MEM.  Success is
+ * indicated by comparing RETURN with OLD.
+ */
+#define __cmpxchg_relaxed(ptr, old, new, size)				\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(*(ptr)) __old = (old);				\
+	__typeof__(*(ptr)) __new = (new);				\
+	__typeof__(*(ptr)) __ret;					\
+	register unsigned int __rc;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.w %0, %2\n"				\
+			"	bne  %0, %z3, 1f\n"			\
+			"	sc.w %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.d %0, %2\n"				\
+			"	bne %0, %z3, 1f\n"			\
+			"	sc.d %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define cmpxchg_relaxed(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_relaxed((ptr),			\
+					_o_, _n_, sizeof(*(ptr)));	\
+})
+
+#define __cmpxchg_acquire(ptr, old, new, size)				\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(*(ptr)) __old = (old);				\
+	__typeof__(*(ptr)) __new = (new);				\
+	__typeof__(*(ptr)) __ret;					\
+	register unsigned int __rc;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.w %0, %2\n"				\
+			"	bne  %0, %z3, 1f\n"			\
+			"	sc.w %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			RISCV_ACQUIRE_BARRIER				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.d %0, %2\n"				\
+			"	bne %0, %z3, 1f\n"			\
+			"	sc.d %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			RISCV_ACQUIRE_BARRIER				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define cmpxchg_acquire(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_acquire((ptr),			\
+					_o_, _n_, sizeof(*(ptr)));	\
+})
+
+#define __cmpxchg_release(ptr, old, new, size)				\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(*(ptr)) __old = (old);				\
+	__typeof__(*(ptr)) __new = (new);				\
+	__typeof__(*(ptr)) __ret;					\
+	register unsigned int __rc;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			RISCV_RELEASE_BARRIER				\
+			"0:	lr.w %0, %2\n"				\
+			"	bne  %0, %z3, 1f\n"			\
+			"	sc.w %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			RISCV_RELEASE_BARRIER				\
+			"0:	lr.d %0, %2\n"				\
+			"	bne %0, %z3, 1f\n"			\
+			"	sc.d %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define cmpxchg_release(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_release((ptr),			\
+					_o_, _n_, sizeof(*(ptr)));	\
+})
+
+#define __cmpxchg(ptr, old, new, size)					\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(*(ptr)) __old = (__typeof__(*(ptr)))(old);				\
+	__typeof__(*(ptr)) __new = (__typeof__(*(ptr)))(new);				\
+	__typeof__(*(ptr)) __ret;					\
+	register unsigned int __rc;					\
+	switch (size) {							\
+	case 4:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.w %0, %2\n"				\
+			"	bne  %0, %z3, 1f\n"			\
+			"	sc.w.rl %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"	fence rw, rw\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	case 8:								\
+		__asm__ __volatile__ (					\
+			"0:	lr.d %0, %2\n"				\
+			"	bne %0, %z3, 1f\n"			\
+			"	sc.d.rl %1, %z4, %2\n"			\
+			"	bnez %1, 0b\n"				\
+			"	fence rw, rw\n"				\
+			"1:\n"						\
+			: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr)	\
+			: "rJ" (__old), "rJ" (__new)			\
+			: "memory");					\
+		break;							\
+	default:							\
+		ASSERT_UNREACHABLE();					\
+	}								\
+	__ret;								\
+})
+
+#define cmpxchg(ptr, o, n)						\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg((ptr),				\
+				       _o_, _n_, sizeof(*(ptr)));	\
+})
+
+#define cmpxchg_local(ptr, o, n)					\
+	(__cmpxchg_relaxed((ptr), (o), (n), sizeof(*(ptr))))
+
+#define cmpxchg32(ptr, o, n)						\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
+	cmpxchg((ptr), (o), (n));					\
+})
+
+#define cmpxchg32_local(ptr, o, n)					\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
+	cmpxchg_relaxed((ptr), (o), (n))				\
+})
+
+#define cmpxchg64(ptr, o, n)						\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg((ptr), (o), (n));					\
+})
+
+#define cmpxchg64_local(ptr, o, n)					\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_relaxed((ptr), (o), (n));				\
+})
+
+#endif /* _ASM_RISCV_CMPXCHG_H */
