[PATCH rdma-next 6/8] RDMA/bnxt_re: Validate rate limit attribute in modify QP

[Edward Srouji <edwards@nvidia.com>]

From: Maher Sanalla <msanalla@nvidia.com>

Rate limit transition validation for RC QPs currently relies on
the IB core qp_state_table. Add a driver-level helper to validate
the rate limit attribute directly during QP modify, ensuring it
is only accepted for RC QPs in INIT->RTR, RTR->RTS and RTS->RTS
transitions.

This makes the driver responsible for rate limit validation
and prepares for a follow-up IB core change that delegates
IB_QP_RATE_LIMIT and all future non-standard modify attributes
handling to individual vendor drivers.

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
---
 drivers/infiniband/hw/bnxt_re/ib_verbs.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index ccb362d6d2e669160174cc562d4e3d8d22b110db..14d2533d7439f2c160ceeea3d0c1e2fe9abcd9f5 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -2286,6 +2286,23 @@ static int bnxt_re_modify_shadow_qp(struct bnxt_re_dev *rdev,
 	return rc;
 }
 
+static bool bnxt_re_is_modify_ok(enum ib_qp_attr_mask ext_mask,
+				 enum ib_qp_type type, enum ib_qp_state cur,
+				 enum ib_qp_state next)
+{
+	if (!ext_mask)
+		return true;
+
+	if (ext_mask & ~IB_QP_RATE_LIMIT)
+		return false;
+
+	/* Rate limit is only supported for RC QPs during specific transitions */
+	return type == IB_QPT_RC &&
+	       ((cur == IB_QPS_INIT && next == IB_QPS_RTR) ||
+		(cur == IB_QPS_RTR && next == IB_QPS_RTS) ||
+		(cur == IB_QPS_RTS && next == IB_QPS_RTS));
+}
+
 int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
 		      int qp_attr_mask, struct ib_udata *udata)
 {
@@ -2310,7 +2327,10 @@ int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
 		curr_qp_state = __to_ib_qp_state(qp->qplib_qp.cur_qp_state);
 		new_qp_state = qp_attr->qp_state;
 		if (!ib_modify_qp_is_ok(curr_qp_state, new_qp_state,
-					ib_qp->qp_type, qp_attr_mask)) {
+					ib_qp->qp_type, qp_attr_mask) ||
+		    !bnxt_re_is_modify_ok(qp_attr_mask & ~IB_QP_ATTR_STANDARD_BITS,
+					  ib_qp->qp_type, curr_qp_state,
+					  new_qp_state)) {
 			ibdev_err(&rdev->ibdev,
 				  "Invalid attribute mask: %#x specified ",
 				  qp_attr_mask);

-- 
2.49.0