diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 51529c33c7bf2f01d7800af4cf817f7fbc063f6a..30c91d56593374fcb8b43a1be5a5fe6eefa00a3c 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -213,7 +213,7 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
 	if (nmi_alloc_mcesa(&lc->mcesad))
 		goto out;
 	lowcore_ptr[cpu] = lc;
-	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
+	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc));
 	return 0;
 
 out: