[IB] mthca: detect SRQ overflow
The hardware relies on us keeping one extra work request that never
gets used in SRQs. Add checks to the SRQ work request posting
functions so that they fail when someone is about to use up that extra
work request, rather than when someone uses the very last work request.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c
index 13d2290..e464321 100644
--- a/drivers/infiniband/hw/mthca/mthca_srq.c
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -438,6 +438,14 @@
wqe = get_wqe(srq, ind);
next_ind = *wqe_to_link(wqe);
+
+ if (next_ind < 0) {
+ mthca_err(dev, "SRQ %06x full\n", srq->srqn);
+ err = -ENOMEM;
+ *bad_wr = wr;
+ break;
+ }
+
prev_wqe = srq->last;
srq->last = wqe;
@@ -529,6 +537,13 @@
wqe = get_wqe(srq, ind);
next_ind = *wqe_to_link(wqe);
+ if (next_ind < 0) {
+ mthca_err(dev, "SRQ %06x full\n", srq->srqn);
+ err = -ENOMEM;
+ *bad_wr = wr;
+ break;
+ }
+
((struct mthca_next_seg *) wqe)->nda_op =
cpu_to_be32((next_ind << srq->wqe_shift) | 1);
((struct mthca_next_seg *) wqe)->ee_nds = 0;