1 files changed, 27 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/lib/arm64/spinlock.c b/tools/testing/selftests/kvm/lib/arm64/spinlock.c
new file mode 100644
index 000000000000..a076e780be5d
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/arm64/spinlock.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM64 Spinlock support
+ */
+#include <stdint.h>
+
+#include "spinlock.h"
+
+void spin_lock(struct spinlock *lock)
+{
+	int val, res;
+
+	asm volatile(
+	"1:	ldaxr	%w0, [%2]\n"
+	"	cbnz	%w0, 1b\n"
+	"	mov	%w0, #1\n"
+	"	stxr	%w1, %w0, [%2]\n"
+	"	cbnz	%w1, 1b\n"
+	: "=&r" (val), "=&r" (res)
+	: "r" (&lock->v)
+	: "memory");
+}
+
+void spin_unlock(struct spinlock *lock)
+{
+	asm volatile("stlr wzr, [%0]\n"	: : "r" (&lock->v) : "memory");
+}