IB/mlx5: Avoid calling query device for reading pkey table length

Pkey table length for all the ports of the device is the same.  Currently
get_ports_cap() reads and stores it for each port by querying the device
which reads more than just pkey table length.

For representor device ports which can be in range of hundreds, it queries
is for each such port and end up returning same value for all the ports.

When in representor mode, modify QP accesses pkey port caps for a port
index that can be outside of the port_caps table.

Hence, simplify the logic to query the max pkey table length only once
during device initialization sequence.

Link: https://lore.kernel.org/r/20210203130133.4057329-3-leon@kernel.org
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/mlx5/mad.c

@@ -549,7 +549,7 @@ int mlx5_query_mad_ifc_port(struct ib_device *ibdev, u8 port,
 	props->port_cap_flags	= be32_to_cpup((__be32 *)(out_mad->data + 20));
 	props->gid_tbl_len	= out_mad->data[50];
 	props->max_msg_sz	= 1 << MLX5_CAP_GEN(mdev, log_max_msg);
-	props->pkey_tbl_len	= dev->port_caps[port - 1].pkey_table_len;
+	props->pkey_tbl_len	= dev->pkey_table_len;
 	props->bad_pkey_cntr	= be16_to_cpup((__be16 *)(out_mad->data + 46));
 	props->qkey_viol_cntr	= be16_to_cpup((__be16 *)(out_mad->data + 48));
 	props->active_width	= out_mad->data[31] & 0xf;

drivers/infiniband/hw/mlx5/main.c

@@ -816,9 +816,7 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 	if (err)
 		return err;
 
-	err = mlx5_query_max_pkeys(ibdev, &props->max_pkeys);
-	if (err)
-		return err;
+	props->max_pkeys = dev->pkey_table_len;
 
 	err = mlx5_query_vendor_id(ibdev, &props->vendor_id);
 	if (err)
@@ -2979,40 +2977,26 @@ static void get_ext_port_caps(struct mlx5_ib_dev *dev)
 
 static int __get_port_caps(struct mlx5_ib_dev *dev, u8 port)
 {
-	struct ib_device_attr *dprops = NULL;
 	struct ib_port_attr *pprops = NULL;
 	int err = -ENOMEM;
 
 	pprops = kzalloc(sizeof(*pprops), GFP_KERNEL);
 	if (!pprops)
 		goto out;
 
-	dprops = kmalloc(sizeof(*dprops), GFP_KERNEL);
-	if (!dprops)
-		goto out;
-
-	err = mlx5_ib_query_device(&dev->ib_dev, dprops, NULL);
-	if (err) {
-		mlx5_ib_warn(dev, "query_device failed %d\n", err);
-		goto out;
-	}
-
 	err = mlx5_ib_query_port(&dev->ib_dev, port, pprops);
 	if (err) {
 		mlx5_ib_warn(dev, "query_port %d failed %d\n",
 			     port, err);
 		goto out;
 	}
 
-	dev->port_caps[port - 1].pkey_table_len = dprops->max_pkeys;
 	dev->port_caps[port - 1].gid_table_len = pprops->gid_tbl_len;
 	mlx5_ib_dbg(dev, "port %d: pkey_table_len %d, gid_table_len %d\n",
-		    port, dprops->max_pkeys, pprops->gid_tbl_len);
+		    port, dev->pkey_table_len, pprops->gid_tbl_len);
 
 out:
 	kfree(pprops);
-	kfree(dprops);
-
 	return err;
 }
 
@@ -3979,6 +3963,10 @@ static int mlx5_ib_stage_init_init(struct mlx5_ib_dev *dev)
 	if (err)
 		goto err_mp;
 
+	err = mlx5_query_max_pkeys(&dev->ib_dev, &dev->pkey_table_len);
+	if (err)
+		goto err_mp;
+
 	if (mlx5_use_mad_ifc(dev))
 		get_ext_port_caps(dev);
 

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -1038,7 +1038,6 @@ struct mlx5_var_table {
 
 struct mlx5_port_caps {
 	int gid_table_len;
-	int pkey_table_len;
 	bool has_smi;
 	u8 ext_port_cap;
 };
@@ -1104,6 +1103,7 @@ struct mlx5_ib_dev {
 
 	struct xarray sig_mrs;
 	struct mlx5_port_caps port_caps[MLX5_MAX_PORTS];
+	u16 pkey_table_len;
 };
 
 static inline struct mlx5_ib_cq *to_mibcq(struct mlx5_core_cq *mcq)

drivers/infiniband/hw/mlx5/qp.c

@@ -4231,7 +4231,6 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	enum ib_qp_type qp_type;
 	enum ib_qp_state cur_state, new_state;
 	int err = -EINVAL;
-	int port;
 
 	if (!mlx5_ib_modify_qp_allowed(dev, qp, ibqp->qp_type))
 		return -EOPNOTSUPP;
@@ -4276,10 +4275,6 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	cur_state = attr_mask & IB_QP_CUR_STATE ? attr->cur_qp_state : qp->state;
 	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
 
-	if (!(cur_state == new_state && cur_state == IB_QPS_RESET)) {
-		port = attr_mask & IB_QP_PORT ? attr->port_num : qp->port;
-	}
-
 	if (qp->flags & IB_QP_CREATE_SOURCE_QPN) {
 		if (attr_mask & ~(IB_QP_STATE | IB_QP_CUR_STATE)) {
 			mlx5_ib_dbg(dev, "invalid attr_mask 0x%x when underlay QP is used\n",
@@ -4308,14 +4303,10 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		goto out;
 	}
 
-	if (attr_mask & IB_QP_PKEY_INDEX) {
-		port = attr_mask & IB_QP_PORT ? attr->port_num : qp->port;
-		if (attr->pkey_index >=
-		    dev->port_caps[port - 1].pkey_table_len) {
-			mlx5_ib_dbg(dev, "invalid pkey index %d\n",
-				    attr->pkey_index);
-			goto out;
-		}
+	if ((attr_mask & IB_QP_PKEY_INDEX) &&
+	    attr->pkey_index >= dev->pkey_table_len) {
+		mlx5_ib_dbg(dev, "invalid pkey index %d\n", attr->pkey_index);
+		goto out;
 	}
 
 	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&