Re: [PATCH rdma-rext V2 2/5] RDMA/bnxt_re: Add support for QP rate limiting

[Leon Romanovsky <leon@kernel.org>]

On Thu, Jan 29, 2026 at 03:51:30PM +0530, Kalesh AP wrote:
> Broadcom P7 chips supports applying rate limit to RC QPs.
> It allows adjust shaper rate values during the INIT -> RTR,
> RTR -> RTS, RTS -> RTS state changes or after QP transitions
> to RTR or RTS.
> 
> Signed-off-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
> Reviewed-by: Hongguang Gao <hongguang.gao@broadcom.com>
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> ---
>  drivers/infiniband/hw/bnxt_re/ib_verbs.c  | 17 ++++++++++++++++-
>  drivers/infiniband/hw/bnxt_re/qplib_fp.c  | 12 +++++++++++-
>  drivers/infiniband/hw/bnxt_re/qplib_fp.h  |  3 +++
>  drivers/infiniband/hw/bnxt_re/qplib_res.h |  6 ++++++
>  drivers/infiniband/hw/bnxt_re/qplib_sp.c  |  5 +++++
>  drivers/infiniband/hw/bnxt_re/qplib_sp.h  |  2 ++
>  drivers/infiniband/hw/bnxt_re/roce_hsi.h  | 13 +++++++++----
>  7 files changed, 52 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> index f19b55c13d58..859e5b4e0d85 100644
> --- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> +++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> @@ -2089,7 +2089,7 @@ int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
>  	unsigned int flags;
>  	u8 nw_type;
>  
> -	if (qp_attr_mask & ~IB_QP_ATTR_STANDARD_BITS)
> +	if (qp_attr_mask & ~(IB_QP_ATTR_STANDARD_BITS | IB_QP_RATE_LIMIT))
>  		return -EOPNOTSUPP;
>  
>  	qp->qplib_qp.modify_flags = 0;
> @@ -2129,6 +2129,21 @@ int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
>  			bnxt_re_unlock_cqs(qp, flags);
>  		}
>  	}
> +
> +	if (qp_attr_mask & IB_QP_RATE_LIMIT) {
> +		if (qp->qplib_qp.type != IB_QPT_RC ||
> +		    !_is_modify_qp_rate_limit_supported(dev_attr->dev_cap_flags2))
> +			return -EOPNOTSUPP;
> +		/* check rate limit within device limits */
> +		if (qp_attr->rate_limit > dev_attr->rate_limit_max ||
> +		    qp_attr->rate_limit < dev_attr->rate_limit_min) {
> +			ibdev_err(&rdev->ibdev, "Invalid rate_limit value\n");

Kernel rarely needs to check this. Or userspace, or FW should check it.

> +			return -EINVAL;
> +		}
> +		qp->qplib_qp.ext_modify_flags |=
> +			CMDQ_MODIFY_QP_EXT_MODIFY_MASK_RATE_LIMIT_VALID;
> +		qp->qplib_qp.rate_limit = qp_attr->rate_limit;
> +	}
>  	if (qp_attr_mask & IB_QP_EN_SQD_ASYNC_NOTIFY) {
>  		qp->qplib_qp.modify_flags |=
>  				CMDQ_MODIFY_QP_MODIFY_MASK_EN_SQD_ASYNC_NOTIFY;
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> index c88f049136fc..3e44311bf939 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> @@ -1313,8 +1313,8 @@ int bnxt_qplib_modify_qp(struct bnxt_qplib_res *res, struct bnxt_qplib_qp *qp)
>  	struct bnxt_qplib_cmdqmsg msg = {};
>  	struct cmdq_modify_qp req = {};
>  	u16 vlan_pcp_vlan_dei_vlan_id;
> +	u32 bmask, bmask_ext;
>  	u32 temp32[4];
> -	u32 bmask;
>  	int rc;
>  
>  	bnxt_qplib_rcfw_cmd_prep((struct cmdq_base *)&req,
> @@ -1329,9 +1329,16 @@ int bnxt_qplib_modify_qp(struct bnxt_qplib_res *res, struct bnxt_qplib_qp *qp)
>  		    is_optimized_state_transition(qp))
>  			bnxt_set_mandatory_attributes(res, qp, &req);
>  	}
> +
>  	bmask = qp->modify_flags;
>  	req.modify_mask = cpu_to_le32(qp->modify_flags);
> +	bmask_ext = qp->ext_modify_flags;
> +	req.ext_modify_mask = cpu_to_le32(qp->ext_modify_flags);
>  	req.qp_cid = cpu_to_le32(qp->id);
> +
> +	if (bmask_ext & CMDQ_MODIFY_QP_EXT_MODIFY_MASK_RATE_LIMIT_VALID)
> +		req.rate_limit = cpu_to_le32(qp->rate_limit);
> +
>  	if (bmask & CMDQ_MODIFY_QP_MODIFY_MASK_STATE) {
>  		req.network_type_en_sqd_async_notify_new_state =
>  				(qp->state & CMDQ_MODIFY_QP_NEW_STATE_MASK) |
> @@ -1429,6 +1436,9 @@ int bnxt_qplib_modify_qp(struct bnxt_qplib_res *res, struct bnxt_qplib_qp *qp)
>  	rc = bnxt_qplib_rcfw_send_message(rcfw, &msg);
>  	if (rc)
>  		return rc;
> +
> +	if (bmask_ext & CMDQ_MODIFY_QP_EXT_MODIFY_MASK_RATE_LIMIT_VALID)
> +		qp->shaper_allocation_status = resp.shaper_allocation_status;
>  	qp->cur_qp_state = qp->state;
>  	return 0;
>  }
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.h b/drivers/infiniband/hw/bnxt_re/qplib_fp.h
> index 1b414a73b46d..30c3f99be07b 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.h
> @@ -280,6 +280,7 @@ struct bnxt_qplib_qp {
>  	u8				state;
>  	u8				cur_qp_state;
>  	u64				modify_flags;
> +	u32				ext_modify_flags;
>  	u32				max_inline_data;
>  	u32				mtu;
>  	u8				path_mtu;
> @@ -346,6 +347,8 @@ struct bnxt_qplib_qp {
>  	bool				is_host_msn_tbl;
>  	u8				tos_dscp;
>  	u32				ugid_index;
> +	u32				rate_limit;
> +	u8				shaper_allocation_status;
>  };
>  
>  #define BNXT_RE_MAX_MSG_SIZE	0x80000000
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_res.h b/drivers/infiniband/hw/bnxt_re/qplib_res.h
> index 2ea3b7f232a3..43f9c564e97c 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_res.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_res.h
> @@ -623,4 +623,10 @@ static inline bool _is_max_srq_ext_supported(u16 dev_cap_ext_flags_2)
>  	return !!(dev_cap_ext_flags_2 & CREQ_QUERY_FUNC_RESP_SB_MAX_SRQ_EXTENDED);
>  }
>  
> +static inline bool _is_modify_qp_rate_limit_supported(u16 dev_cap_ext_flags2)
> +{
> +	return !!(dev_cap_ext_flags2 &
> +		  CREQ_QUERY_FUNC_RESP_SB_MODIFY_QP_RATE_LIMIT_SUPPORTED);

There is no need in !! for boolean check of one bit.

Thanks