diff --git a/kernel/sdma.c b/kernel/sdma.c
index e66dcc46..d59a5a48 100644
--- a/kernel/sdma.c
+++ b/kernel/sdma.c
@@ -798,20 +798,28 @@ struct sdma_engine *sdma_select_engine_vl(
 	if (vl >= num_vls) {
 #else
 	if (vl >= HFI1_MAX_VLS_SUPPORTED) {
-#endif /* __HFI1_ORIG__ */	
+#endif /* __HFI1_ORIG__ */
 		rval = NULL;
 		goto done;
 	}
 
+#ifdef __HFI1_ORIG__
 	rcu_read_lock();
 	m = rcu_dereference(dd->sdma_map);
+#else
+	m = (volatile struct sdma_vl_map *)dd->sdma_map;
+#endif
 	if (unlikely(!m)) {
+#ifdef __HFI1_ORIG__
 		rcu_read_unlock();
+#endif
 		return &dd->per_sdma[0];
 	}
 	e = m->map[vl & m->mask];
 	rval = e->sde[selector & e->mask];
+#ifdef __HFI1_ORIG__
 	rcu_read_unlock();
+#endif
 
 done:
 	rval =  !rval ? &dd->per_sdma[0] : rval;
@@ -881,6 +889,7 @@ static struct rhashtable_params sdma_rht_params = {
 struct sdma_engine *sdma_select_user_engine(struct hfi1_devdata *dd,
 					    u32 selector, u8 vl)
 {
+#ifdef __HFI1_ORIG__
 	struct sdma_rht_node *rht_node;
 	struct sdma_engine *sde = NULL;
 	const struct cpumask *current_mask = tsk_cpus_allowed(current);
@@ -909,6 +918,7 @@ struct sdma_engine *sdma_select_user_engine(struct hfi1_devdata *dd,
 		return sde;
 
 out:
+#endif
 	return sdma_select_engine_vl(dd, selector, vl);
 }
 
@@ -3463,4 +3473,4 @@ void _sdma_engine_progress_schedule(
 		  sde->progress_mask);
 }
 
-#endif /* __HFI1_ORIG__ */
\ No newline at end of file
+#endif /* __HFI1_ORIG__ */
diff --git a/kernel/user_sdma.c b/kernel/user_sdma.c
index 470e8118..2e333a83 100644
--- a/kernel/user_sdma.c
+++ b/kernel/user_sdma.c
@@ -758,8 +758,13 @@ int hfi1_user_sdma_process_request(void *private_data, struct iovec *iovec,
 	dlid = be16_to_cpu(req->hdr.lrh[1]);
 	selector = dlid_to_selector(dlid);
 	selector += uctxt->ctxt + fd->subctxt;
-	/* TODO: sdma_select_user_engine check the rcu stuff */
-	//req->sde = sdma_select_user_engine(dd, selector, vl);
+	/* TODO: check the rcu stuff */
+	/*
+	 * XXX: didn't we conclude that we don't need to worry about RCU here?
+	 * the mapping is created at driver initialization, the rest of the
+	 * accesses are read-only
+	 */
+	req->sde = sdma_select_user_engine(dd, selector, vl);
 
 	if (!req->sde || !sdma_running(req->sde)) {
 		ret = -ECOMM;
@@ -1722,4 +1727,4 @@ static int sdma_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
 	return 0;
 }
 
-#endif /* __HFI1_ORIG__ */
\ No newline at end of file
+#endif /* __HFI1_ORIG__ */