diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c
index c757612244..aa8ec6ba6d 100644
--- a/target/s390x/tcg/mem_helper.c
+++ b/target/s390x/tcg/mem_helper.c
@@ -1800,13 +1800,7 @@ static uint32_t do_csst(CPUS390XState *env, uint32_t r3, uint64_t a1,
             uint32_t ov;
 
             if (parallel) {
-#ifdef CONFIG_USER_ONLY
-                uint32_t *haddr = g2h(env_cpu(env), a1);
-                ov = qatomic_cmpxchg__nocheck(haddr, cv, nv);
-#else
-                MemOpIdx oi = make_memop_idx(MO_TEUL | MO_ALIGN, mem_idx);
-                ov = cpu_atomic_cmpxchgl_be_mmu(env, a1, cv, nv, oi, ra);
-#endif
+                ov = cpu_atomic_cmpxchgl_be_mmu(env, a1, cv, nv, oi4, ra);
             } else {
                 ov = cpu_ldl_mmu(env, a1, oi4, ra);
                 cpu_stl_mmu(env, a1, (ov == cv ? nv : ov), oi4, ra);