[IB] mthca: fix posting long lists of receive work requests
In Tavor mode, when posting a long list of receive work requests, a
doorbell must be rung every 256 requests. Add code to do this when
required.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
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 292f55b..c3c0331 100644
--- a/drivers/infiniband/hw/mthca/mthca_srq.c
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -414,6 +414,7 @@
{
struct mthca_dev *dev = to_mdev(ibsrq->device);
struct mthca_srq *srq = to_msrq(ibsrq);
+ __be32 doorbell[2];
unsigned long flags;
int err = 0;
int first_ind;
@@ -429,6 +430,25 @@
first_ind = srq->first_free;
for (nreq = 0; wr; ++nreq, wr = wr->next) {
+ if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
+ nreq = 0;
+
+ doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
+ doorbell[1] = cpu_to_be32(srq->srqn << 8);
+
+ /*
+ * Make sure that descriptors are written
+ * before doorbell is rung.
+ */
+ wmb();
+
+ mthca_write64(doorbell,
+ dev->kar + MTHCA_RECEIVE_DOORBELL,
+ MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
+
+ first_ind = srq->first_free;
+ }
+
ind = srq->first_free;
if (ind < 0) {
@@ -491,8 +511,6 @@
}
if (likely(nreq)) {
- __be32 doorbell[2];
-
doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
doorbell[1] = cpu_to_be32((srq->srqn << 8) | nreq);