RDMA/ionic: Validate rate limit attribute in modify QP

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>
Link: https://patch.msgid.link/20260524-packet-pacing-v1-7-3d79439f8d08@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/ionic/ionic_controlpath.c b/drivers/infiniband/hw/ionic/ionic_controlpath.c
index db18c315cc2110bf648c8a8e11b0ba6a715e8c56..9d91f7667d4f83495a201e05c147de0019dc9eca 100644 (file)
--- a/drivers/infiniband/hw/ionic/ionic_controlpath.c
+++ b/drivers/infiniband/hw/ionic/ionic_controlpath.c
@@ -2535,6 +2535,23 @@ static bool ionic_qp_cur_state_is_ok(enum ib_qp_state q_state,
        return false;
 }
 
+static bool ionic_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));
+}
+
 static int ionic_check_modify_qp(struct ionic_qp *qp, struct ib_qp_attr *attr,
                                 int mask)
 {
@@ -2547,7 +2564,9 @@ static int ionic_check_modify_qp(struct ionic_qp *qp, struct ib_qp_attr *attr,
            !ionic_qp_cur_state_is_ok(qp->state, attr->cur_qp_state))
                return -EINVAL;
 
-       if (!ib_modify_qp_is_ok(cur_state, next_state, qp->ibqp.qp_type, mask))
+       if (!ib_modify_qp_is_ok(cur_state, next_state, qp->ibqp.qp_type, mask) ||
+           !ionic_is_modify_ok(mask & ~IB_QP_ATTR_STANDARD_BITS,
+                               qp->ibqp.qp_type, cur_state, next_state))
                return -EINVAL;
 
        /* unprivileged qp not allowed privileged qkey */