RDMA/mlx5: Fix validation of max_rd_atomic caps for DC

Currently, when modifying DC, we validate max_rd_atomic user attribute
against the RC cap, validate against DC. RC and DC QP types have different
device limitations.

This can cause userspace created DC QPs to malfunction.

Fixes: c32a4f2 ("IB/mlx5: Add support for DC Initiator QP")
Link: https://lore.kernel.org/r/0c5aee72cea188c3bb770f4207cce7abc9b6fc74.1672231736.git.leonro@nvidia.com
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/mlx5/qp.c

@@ -4502,6 +4502,40 @@ static bool mlx5_ib_modify_qp_allowed(struct mlx5_ib_dev *dev,
 	return false;
 }
 
+static int validate_rd_atomic(struct mlx5_ib_dev *dev, struct ib_qp_attr *attr,
+			      int attr_mask, enum ib_qp_type qp_type)
+{
+	int log_max_ra_res;
+	int log_max_ra_req;
+
+	if (qp_type == MLX5_IB_QPT_DCI) {
+		log_max_ra_res = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_res_dc);
+		log_max_ra_req = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_req_dc);
+	} else {
+		log_max_ra_res = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_res_qp);
+		log_max_ra_req = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_req_qp);
+	}
+
+	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
+	    attr->max_rd_atomic > log_max_ra_res) {
+		mlx5_ib_dbg(dev, "invalid max_rd_atomic value %d\n",
+			    attr->max_rd_atomic);
+		return false;
+	}
+
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
+	    attr->max_dest_rd_atomic > log_max_ra_req) {
+		mlx5_ib_dbg(dev, "invalid max_dest_rd_atomic value %d\n",
+			    attr->max_dest_rd_atomic);
+		return false;
+	}
+	return true;
+}
+
 int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		      int attr_mask, struct ib_udata *udata)
 {
@@ -4589,21 +4623,8 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		goto out;
 	}
 
-	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
-	    attr->max_rd_atomic >
-	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_res_qp))) {
-		mlx5_ib_dbg(dev, "invalid max_rd_atomic value %d\n",
-			    attr->max_rd_atomic);
-		goto out;
-	}
-
-	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
-	    attr->max_dest_rd_atomic >
-	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_req_qp))) {
-		mlx5_ib_dbg(dev, "invalid max_dest_rd_atomic value %d\n",
-			    attr->max_dest_rd_atomic);
+	if (!validate_rd_atomic(dev, attr, attr_mask, qp_type))
 		goto out;
-	}
 
 	if (cur_state == new_state && cur_state == IB_QPS_RESET) {
 		err = 0;