Subject: Re: [PATCH for bnxt_re V4 15/21] RDMA/bnxt_re: Support post_recv

From: Leon Romanovsky <[email-masked]>
Date: Tue, 24 Jan 2017 13:59:43 +0200

On Wed, Dec 21, 2016 at 03:42:04AM -0800, Selvin Xavier wrote:
> Enables the fastpath verb ib_post_recv.
>
> v3: Fixes sparse warnings
>
> Signed-off-by: Eddie Wai <[email-masked]>
> Signed-off-by: Devesh Sharma <[email-masked]>
> Signed-off-by: Somnath Kotur <[email-masked]>
> Signed-off-by: Sriharsha Basavapatna <[email-masked]>
> Signed-off-by: Selvin Xavier <[email-masked]>
> ---
>  drivers/infiniband/hw/bnxt_re/ib_verbs.c | 123 +++++++++++++++++++++++++++++++
>  drivers/infiniband/hw/bnxt_re/ib_verbs.h |   2 +
>  drivers/infiniband/hw/bnxt_re/main.c     |   2 +
>  drivers/infiniband/hw/bnxt_re/qplib_fp.c | 100 +++++++++++++++++++++++++
>  drivers/infiniband/hw/bnxt_re/qplib_fp.h |   8 ++
>  5 files changed, 235 insertions(+)
>
> diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> index e659490..7476994c 100644
> --- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> +++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> @@ -1637,6 +1637,51 @@ static int bnxt_re_build_qp1_send_v2(struct bnxt_re_qp *qp,
>  	return rc;
>  }
>
> +/* For the MAD layer, it only provides the recv SGE the size of
> + * ib_grh + MAD datagram.  No Ethernet headers, Ethertype, BTH, DETH,
> + * nor RoCE iCRC.  The Cu+ solution must provide buffer for the entire
> + * receive packet (334 bytes) with no VLAN and then copy the GRH
> + * and the MAD datagram out to the provided SGE.
> + */
> +static int bnxt_re_build_qp1_shadow_qp_recv(struct bnxt_re_qp *qp,
> +					    struct ib_recv_wr *wr,
> +					    struct bnxt_qplib_swqe *wqe,
> +					    int payload_size)
> +{
> +	struct bnxt_qplib_sge ref, sge;
> +	u32 rq_prod_index;
> +	struct bnxt_re_sqp_entries *sqp_entry;
> +
> +	rq_prod_index = bnxt_qplib_get_rq_prod_index(&qp->qplib_qp);
> +
> +	if (bnxt_qplib_get_qp1_rq_buf(&qp->qplib_qp, &sge)) {
> +		/* Create 1 SGE to receive the entire
> +		 * ethernet packet
> +		 */
> +		/* Save the reference from ULP */
> +		ref.addr = wqe->sg_list[0].addr;
> +		ref.lkey = wqe->sg_list[0].lkey;
> +		ref.size = wqe->sg_list[0].size;
> +
> +		sqp_entry = &qp->rdev->sqp_tbl[rq_prod_index];
> +
> +		/* SGE 1 */
> +		wqe->sg_list[0].addr = sge.addr;
> +		wqe->sg_list[0].lkey = sge.lkey;
> +		wqe->sg_list[0].size = BNXT_QPLIB_MAX_QP1_RQ_HDR_SIZE_V2;
> +		sge.size -= wqe->sg_list[0].size;
> +
> +		sqp_entry->sge.addr = ref.addr;
> +		sqp_entry->sge.lkey = ref.lkey;
> +		sqp_entry->sge.size = ref.size;
> +		/* Store the wrid for reporting completion */
> +		sqp_entry->wrid = wqe->wr_id;
> +		/* change the wqe->wrid to table index */
> +		wqe->wr_id = rq_prod_index;
> +	}
> +	return 0;
> +}
> +
>  static int is_ud_qp(struct bnxt_re_qp *qp)
>  {
>  	return qp->qplib_qp.type == CMDQ_CREATE_QP_TYPE_UD;
> @@ -1983,6 +2028,84 @@ int bnxt_re_post_send(struct ib_qp *ib_qp, struct ib_send_wr *wr,
>  	return rc;
>  }
>
> +static int bnxt_re_post_recv_shadow_qp(struct bnxt_re_dev *rdev,
> +				       struct bnxt_re_qp *qp,
> +				       struct ib_recv_wr *wr)
> +{
> +	struct bnxt_qplib_swqe wqe;
> +	int rc = 0, payload_sz = 0;
> +
> +	memset(&wqe, 0, sizeof(wqe));
> +	while (wr) {
> +		/* House keeping */
> +		memset(&wqe, 0, sizeof(wqe));
> +
> +		/* Common */
> +		wqe.num_sge = wr->num_sge;
> +		if (wr->num_sge > qp->qplib_qp.rq.max_sge) {
> +			dev_err(rdev_to_dev(rdev),
> +				"Limit exceeded for Receive SGEs");
> +			rc = -EINVAL;
> +			goto bad;

"goto bad" directly to other place in while() to call the "break".
It will be more convenient to call "break" here.

> +		}
> +		payload_sz = bnxt_re_build_sgl(wr->sg_list, wqe.sg_list,
> +					       wr->num_sge);
> +		wqe.wr_id = wr->wr_id;
> +		wqe.type = BNXT_QPLIB_SWQE_TYPE_RECV;
> +
> +		if (!rc)

If we are here, we will always have rc == 0.

> +			rc = bnxt_qplib_post_recv(&qp->qplib_qp, &wqe);
> +bad:
> +		if (rc)
> +			break;
> +
> +		wr = wr->next;
> +	}
> +	bnxt_qplib_post_recv_db(&qp->qplib_qp);
> +	return rc;
> +}