iw_cxgb4: limit IRD/ORD advertised to ULP by device max.

The i40iw initiator sends an MPA-request with ird = 63, ord = 63. The
cxgb4 responder sends a RST.  Since the inbound ord=63 and it exceeds
the max_ird/c4iw_max_read_depth (=32 default), chelsio decides to abort.

Instead, cxgb4 should adjust the ord/ird down before presenting it to
the ULP.

Reported-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/cxgb4/cm.c

@@ -1827,8 +1827,12 @@ static int process_mpa_request(struct c4iw_ep *ep, struct sk_buff *skb)
 				(ep->mpa_pkt + sizeof(*mpa));
 			ep->ird = ntohs(mpa_v2_params->ird) &
 				MPA_V2_IRD_ORD_MASK;
+			ep->ird = min_t(u32, ep->ird,
+					cur_max_read_depth(ep->com.dev));
 			ep->ord = ntohs(mpa_v2_params->ord) &
 				MPA_V2_IRD_ORD_MASK;
+			ep->ord = min_t(u32, ep->ord,
+					cur_max_read_depth(ep->com.dev));
 			PDBG("%s initiator ird %u ord %u\n", __func__, ep->ird,
 			     ep->ord);
 			if (ntohs(mpa_v2_params->ird) & MPA_V2_PEER2PEER_MODEL)