IB/mlx4: Add inline-receive support

When inline-receive is enabled, the HCA may write received
data into the receive WQE.

Inline-receive is enabled by setting its matching bit in
the QP context and each single-packet message with payload
not exceeding the receive WQE size will be delivered to
the WQE.

The completion report will indicate that the payload was placed to the WQE.

It includes:
1) Return maximum supported size of inline-receive by the hardware
in query_device vendor's data part.
2) Enable the feature when requested by the vendor data input.

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 25 insertions, 7 deletions

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 75c0e6c5dd56..d1caa39a3943 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -377,7 +377,8 @@ static int send_wqe_overhead(enum mlx4_ib_qp_type type, u32 flags)
 }
 
 static int set_rq_size(struct mlx4_ib_dev *dev, struct ib_qp_cap *cap,
-		       int is_user, int has_rq, struct mlx4_ib_qp *qp)
+		       int is_user, int has_rq, struct mlx4_ib_qp *qp,
+		       u32 inl_recv_sz)
 {
 	/* Sanity check RQ size before proceeding */
 	if (cap->max_recv_wr > dev->dev->caps.max_wqes - MLX4_IB_SQ_MAX_SPARE ||
@@ -385,18 +386,24 @@ static int set_rq_size(struct mlx4_ib_dev *dev, struct ib_qp_cap *cap,
 		return -EINVAL;
 
 	if (!has_rq) {
-		if (cap->max_recv_wr)
+		if (cap->max_recv_wr || inl_recv_sz)
 			return -EINVAL;
 
 		qp->rq.wqe_cnt = qp->rq.max_gs = 0;
 	} else {
+		u32 max_inl_recv_sz = dev->dev->caps.max_rq_sg *
+			sizeof(struct mlx4_wqe_data_seg);
+		u32 wqe_size;
+
 		/* HW requires >= 1 RQ entry with >= 1 gather entry */
-		if (is_user && (!cap->max_recv_wr || !cap->max_recv_sge))
+		if (is_user && (!cap->max_recv_wr || !cap->max_recv_sge ||
+				inl_recv_sz > max_inl_recv_sz))
 			return -EINVAL;
 
 		qp->rq.wqe_cnt	 = roundup_pow_of_two(max(1U, cap->max_recv_wr));
 		qp->rq.max_gs	 = roundup_pow_of_two(max(1U, cap->max_recv_sge));
-		qp->rq.wqe_shift = ilog2(qp->rq.max_gs * sizeof (struct mlx4_wqe_data_seg));
+		wqe_size = qp->rq.max_gs * sizeof(struct mlx4_wqe_data_seg);
+		qp->rq.wqe_shift = ilog2(max_t(u32, wqe_size, inl_recv_sz));
 	}
 
 	/* leave userspace return values as they were, so as not to break ABI */
@@ -719,9 +726,6 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
 	if (init_attr->sq_sig_type == IB_SIGNAL_ALL_WR)
 		qp->sq_signal_bits = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE);
 
-	err = set_rq_size(dev, &init_attr->cap, !!pd->uobject, qp_has_rq(init_attr), qp);
-	if (err)
-		goto err;
 
 	if (pd->uobject) {
 		struct mlx4_ib_create_qp ucmd;
@@ -731,6 +735,12 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
 			goto err;
 		}
 
+		err = set_rq_size(dev, &init_attr->cap, !!pd->uobject,
+				  qp_has_rq(init_attr), qp, ucmd.inl_recv_sz);
+		if (err)
+			goto err;
+
+		qp->inl_recv_sz = ucmd.inl_recv_sz;
 		qp->sq_no_prefetch = ucmd.sq_no_prefetch;
 
 		err = set_user_sq_size(dev, qp, &ucmd);
@@ -760,6 +770,11 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
 				goto err_mtt;
 		}
 	} else {
+		err = set_rq_size(dev, &init_attr->cap, !!pd->uobject,
+				  qp_has_rq(init_attr), qp, 0);
+		if (err)
+			goto err;
+
 		qp->sq_no_prefetch = 0;
 
 		if (init_attr->create_flags & IB_QP_CREATE_IPOIB_UD_LSO)
@@ -1651,6 +1666,9 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
 		}
 	}
 
+	if (qp->inl_recv_sz)
+		context->param3 |= cpu_to_be32(1 << 25);
+
 	if (ibqp->qp_type == IB_QPT_GSI || ibqp->qp_type == IB_QPT_SMI)
 		context->mtu_msgmax = (IB_MTU_4096 << 5) | 11;
 	else if (ibqp->qp_type == IB_QPT_RAW_PACKET)