diff --git a/tools/testing/selftests/drivers/ntsync/ntsync.c b/tools/testing/selftests/drivers/ntsync/ntsync.c
index 1e145c6dfded..7cd0f40594fd 100644
--- a/tools/testing/selftests/drivers/ntsync/ntsync.c
+++ b/tools/testing/selftests/drivers/ntsync/ntsync.c
@@ -40,6 +40,39 @@ static int post_sem(int sem, __u32 *count)
 	return ioctl(sem, NTSYNC_IOC_SEM_POST, count);
 }
 
+static int read_mutex_state(int mutex, __u32 *count, __u32 *owner)
+{
+	struct ntsync_mutex_args args;
+	int ret;
+
+	memset(&args, 0xcc, sizeof(args));
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_READ, &args);
+	*count = args.count;
+	*owner = args.owner;
+	return ret;
+}
+
+#define check_mutex_state(mutex, count, owner) \
+	({ \
+		__u32 __count, __owner; \
+		int ret = read_mutex_state((mutex), &__count, &__owner); \
+		EXPECT_EQ(0, ret); \
+		EXPECT_EQ((count), __count); \
+		EXPECT_EQ((owner), __owner); \
+	})
+
+static int unlock_mutex(int mutex, __u32 owner, __u32 *count)
+{
+	struct ntsync_mutex_args args;
+	int ret;
+
+	args.owner = owner;
+	args.count = 0xdeadbeef;
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_UNLOCK, &args);
+	*count = args.count;
+	return ret;
+}
+
 static int wait_any(int fd, __u32 count, const int *objs, __u32 owner, __u32 *index)
 {
 	struct ntsync_wait_args args = {0};
@@ -146,4 +179,167 @@ TEST(semaphore_state)
 	close(fd);
 }
 
+TEST(mutex_state)
+{
+	struct ntsync_mutex_args mutex_args;
+	__u32 owner, count, index;
+	struct timespec timeout;
+	int fd, ret, mutex;
+
+	clock_gettime(CLOCK_MONOTONIC, &timeout);
+
+	fd = open("/dev/ntsync", O_CLOEXEC | O_RDONLY);
+	ASSERT_LE(0, fd);
+
+	mutex_args.owner = 123;
+	mutex_args.count = 0;
+	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EINVAL, errno);
+
+	mutex_args.owner = 0;
+	mutex_args.count = 2;
+	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EINVAL, errno);
+
+	mutex_args.owner = 123;
+	mutex_args.count = 2;
+	mutex_args.mutex = 0xdeadbeef;
+	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
+	EXPECT_EQ(0, ret);
+	EXPECT_NE(0xdeadbeef, mutex_args.mutex);
+	mutex = mutex_args.mutex;
+	check_mutex_state(mutex, 2, 123);
+
+	ret = unlock_mutex(mutex, 0, &count);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EINVAL, errno);
+
+	ret = unlock_mutex(mutex, 456, &count);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EPERM, errno);
+	check_mutex_state(mutex, 2, 123);
+
+	ret = unlock_mutex(mutex, 123, &count);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(2, count);
+	check_mutex_state(mutex, 1, 123);
+
+	ret = unlock_mutex(mutex, 123, &count);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(1, count);
+	check_mutex_state(mutex, 0, 0);
+
+	ret = unlock_mutex(mutex, 123, &count);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EPERM, errno);
+
+	ret = wait_any(fd, 1, &mutex, 456, &index);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(0, index);
+	check_mutex_state(mutex, 1, 456);
+
+	ret = wait_any(fd, 1, &mutex, 456, &index);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(0, index);
+	check_mutex_state(mutex, 2, 456);
+
+	ret = unlock_mutex(mutex, 456, &count);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(2, count);
+	check_mutex_state(mutex, 1, 456);
+
+	ret = wait_any(fd, 1, &mutex, 123, &index);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(ETIMEDOUT, errno);
+
+	owner = 0;
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_KILL, &owner);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EINVAL, errno);
+
+	owner = 123;
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_KILL, &owner);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EPERM, errno);
+	check_mutex_state(mutex, 1, 456);
+
+	owner = 456;
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_KILL, &owner);
+	EXPECT_EQ(0, ret);
+
+	memset(&mutex_args, 0xcc, sizeof(mutex_args));
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_READ, &mutex_args);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EOWNERDEAD, errno);
+	EXPECT_EQ(0, mutex_args.count);
+	EXPECT_EQ(0, mutex_args.owner);
+
+	memset(&mutex_args, 0xcc, sizeof(mutex_args));
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_READ, &mutex_args);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EOWNERDEAD, errno);
+	EXPECT_EQ(0, mutex_args.count);
+	EXPECT_EQ(0, mutex_args.owner);
+
+	ret = wait_any(fd, 1, &mutex, 123, &index);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EOWNERDEAD, errno);
+	EXPECT_EQ(0, index);
+	check_mutex_state(mutex, 1, 123);
+
+	owner = 123;
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_KILL, &owner);
+	EXPECT_EQ(0, ret);
+
+	memset(&mutex_args, 0xcc, sizeof(mutex_args));
+	ret = ioctl(mutex, NTSYNC_IOC_MUTEX_READ, &mutex_args);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EOWNERDEAD, errno);
+	EXPECT_EQ(0, mutex_args.count);
+	EXPECT_EQ(0, mutex_args.owner);
+
+	ret = wait_any(fd, 1, &mutex, 123, &index);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(EOWNERDEAD, errno);
+	EXPECT_EQ(0, index);
+	check_mutex_state(mutex, 1, 123);
+
+	close(mutex);
+
+	mutex_args.owner = 0;
+	mutex_args.count = 0;
+	mutex_args.mutex = 0xdeadbeef;
+	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
+	EXPECT_EQ(0, ret);
+	EXPECT_NE(0xdeadbeef, mutex_args.mutex);
+	mutex = mutex_args.mutex;
+	check_mutex_state(mutex, 0, 0);
+
+	ret = wait_any(fd, 1, &mutex, 123, &index);
+	EXPECT_EQ(0, ret);
+	EXPECT_EQ(0, index);
+	check_mutex_state(mutex, 1, 123);
+
+	close(mutex);
+
+	mutex_args.owner = 123;
+	mutex_args.count = ~0u;
+	mutex_args.mutex = 0xdeadbeef;
+	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
+	EXPECT_EQ(0, ret);
+	EXPECT_NE(0xdeadbeef, mutex_args.mutex);
+	mutex = mutex_args.mutex;
+	check_mutex_state(mutex, ~0u, 123);
+
+	ret = wait_any(fd, 1, &mutex, 123, &index);
+	EXPECT_EQ(-1, ret);
+	EXPECT_EQ(ETIMEDOUT, errno);
+
+	close(mutex);
+
+	close(fd);
+}
+
 TEST_HARNESS_MAIN
