[PATCH net-next V5 13/15] net/mlx5: qos: Support cross-device tx scheduling

[Tariq Toukan <tariqt@nvidia.com>]

From: Cosmin Ratiu <cratiu@nvidia.com>

Up to now, rate groups could only contain vports from the same E-Switch.
This patch relaxes that restriction if the device supports it
(HCA_CAP.esw_cross_esw_sched == true) and the right conditions are met:
- Link Aggregation (LAG) is enabled.
- The E-Switches are from the same shared devlink device.

This patch does not yet enable cross-esw scheduling, it's just the last
preparatory patch.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/esw/qos.c | 122 ++++++++++++------
 1 file changed, 86 insertions(+), 36 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index 0d187399d846..b4abb6fa2168 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -50,7 +50,9 @@ struct mlx5_esw_sched_node {
 	enum sched_node_type type;
 	/* The eswitch this node belongs to. */
 	struct mlx5_eswitch *esw;
-	/* The children nodes of this node, empty list for leaf nodes. */
+	/* The children nodes of this node, empty list for leaf nodes.
+	 * Can be from multiple E-Switches.
+	 */
 	struct list_head children;
 	/* Valid only if this node is associated with a vport. */
 	struct mlx5_vport *vport;
@@ -419,6 +421,7 @@ esw_qos_vport_create_sched_element(struct mlx5_esw_sched_node *vport_node,
 	struct mlx5_esw_sched_node *parent = vport_node->parent;
 	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {};
 	struct mlx5_core_dev *dev = vport_node->esw->dev;
+	struct mlx5_vport *vport = vport_node->vport;
 	void *attr;
 
 	if (!mlx5_qos_element_type_supported(
@@ -430,11 +433,18 @@ esw_qos_vport_create_sched_element(struct mlx5_esw_sched_node *vport_node,
 	MLX5_SET(scheduling_context, sched_ctx, element_type,
 		 SCHEDULING_CONTEXT_ELEMENT_TYPE_VPORT);
 	attr = MLX5_ADDR_OF(scheduling_context, sched_ctx, element_attributes);
-	MLX5_SET(vport_element, attr, vport_number, vport_node->vport->vport);
+	MLX5_SET(vport_element, attr, vport_number, vport->vport);
 	MLX5_SET(scheduling_context, sched_ctx, parent_element_id,
 		 parent ? parent->ix : vport_node->esw->qos.root_tsar_ix);
 	MLX5_SET(scheduling_context, sched_ctx, max_average_bw,
 		 vport_node->max_rate);
+	if (vport->dev != dev) {
+		/* The port is assigned to a node on another eswitch. */
+		MLX5_SET(vport_element, attr, eswitch_owner_vhca_id_valid,
+			 true);
+		MLX5_SET(vport_element, attr, eswitch_owner_vhca_id,
+			 MLX5_CAP_GEN(vport->dev, vhca_id));
+	}
 
 	return esw_qos_node_create_sched_element(vport_node, sched_ctx, extack);
 }
@@ -446,6 +456,7 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 {
 	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {};
 	struct mlx5_core_dev *dev = vport_tc_node->esw->dev;
+	struct mlx5_vport *vport = vport_tc_node->vport;
 	void *attr;
 
 	if (!mlx5_qos_element_type_supported(
@@ -457,8 +468,7 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 	MLX5_SET(scheduling_context, sched_ctx, element_type,
 		 SCHEDULING_CONTEXT_ELEMENT_TYPE_VPORT_TC);
 	attr = MLX5_ADDR_OF(scheduling_context, sched_ctx, element_attributes);
-	MLX5_SET(vport_tc_element, attr, vport_number,
-		 vport_tc_node->vport->vport);
+	MLX5_SET(vport_tc_element, attr, vport_number, vport->vport);
 	MLX5_SET(vport_tc_element, attr, traffic_class, vport_tc_node->tc);
 	MLX5_SET(scheduling_context, sched_ctx, max_bw_obj_id,
 		 rate_limit_elem_ix);
@@ -466,6 +476,13 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 		 vport_tc_node->parent->ix);
 	MLX5_SET(scheduling_context, sched_ctx, bw_share,
 		 vport_tc_node->bw_share);
+	if (vport->dev != dev) {
+		/* The port is assigned to a node on another eswitch. */
+		MLX5_SET(vport_tc_element, attr, eswitch_owner_vhca_id_valid,
+			 true);
+		MLX5_SET(vport_tc_element, attr, eswitch_owner_vhca_id,
+			 MLX5_CAP_GEN(vport->dev, vhca_id));
+	}
 
 	return esw_qos_node_create_sched_element(vport_tc_node, sched_ctx,
 						 extack);
@@ -1194,6 +1211,29 @@ static int esw_qos_vport_tc_check_type(enum sched_node_type curr_type,
 	return 0;
 }
 
+static bool esw_qos_validate_unsupported_tc_bw(struct mlx5_eswitch *esw,
+					       u32 *tc_bw)
+{
+	int i, num_tcs = esw_qos_num_tcs(esw->dev);
+
+	for (i = num_tcs; i < DEVLINK_RATE_TCS_MAX; i++)
+		if (tc_bw[i])
+			return false;
+
+	return true;
+}
+
+static bool esw_qos_vport_validate_unsupported_tc_bw(struct mlx5_vport *vport,
+						     u32 *tc_bw)
+{
+	struct mlx5_esw_sched_node *node = vport->qos.sched_node;
+	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
+
+	esw = (node && node->parent) ? node->parent->esw : esw;
+
+	return esw_qos_validate_unsupported_tc_bw(esw, tc_bw);
+}
+
 static int esw_qos_vport_update(struct mlx5_vport *vport,
 				enum sched_node_type type,
 				struct mlx5_esw_sched_node *parent,
@@ -1213,8 +1253,17 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
 	if (err)
 		return err;
 
-	if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type)
+	if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type) {
+		struct mlx5_eswitch *esw = parent ?
+			parent->esw : vport->dev->priv.eswitch;
+
 		esw_qos_tc_arbiter_get_bw_shares(vport_node, curr_tc_bw);
+		if (!esw_qos_validate_unsupported_tc_bw(esw, curr_tc_bw)) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Unsupported traffic classes on the new device");
+			return -EOPNOTSUPP;
+		}
+	}
 
 	esw_qos_vport_disable(vport, extack);
 
@@ -1224,10 +1273,9 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
 		extack = NULL;
 	}
 
-	if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type) {
+	if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type)
 		esw_qos_set_tc_arbiter_bw_shares(vport_node, curr_tc_bw,
 						 extack);
-	}
 
 	return err;
 }
@@ -1575,30 +1623,6 @@ static int esw_qos_devlink_rate_to_mbps(struct mlx5_core_dev *mdev, const char *
 	return 0;
 }
 
-static bool esw_qos_validate_unsupported_tc_bw(struct mlx5_eswitch *esw,
-					       u32 *tc_bw)
-{
-	int i, num_tcs = esw_qos_num_tcs(esw->dev);
-
-	for (i = num_tcs; i < DEVLINK_RATE_TCS_MAX; i++) {
-		if (tc_bw[i])
-			return false;
-	}
-
-	return true;
-}
-
-static bool esw_qos_vport_validate_unsupported_tc_bw(struct mlx5_vport *vport,
-						     u32 *tc_bw)
-{
-	struct mlx5_esw_sched_node *node = vport->qos.sched_node;
-	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
-
-	esw = (node && node->parent) ? node->parent->esw : esw;
-
-	return esw_qos_validate_unsupported_tc_bw(esw, tc_bw);
-}
-
 static bool esw_qos_tc_bw_disabled(u32 *tc_bw)
 {
 	int i;
@@ -1803,18 +1827,44 @@ int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
 	return 0;
 }
 
+static int
+mlx5_esw_validate_cross_esw_scheduling(struct mlx5_eswitch *esw,
+				       struct mlx5_esw_sched_node *parent,
+				       struct netlink_ext_ack *extack)
+{
+	if (!parent || esw == parent->esw)
+		return 0;
+
+	if (!MLX5_CAP_QOS(esw->dev, esw_cross_esw_sched)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cross E-Switch scheduling is not supported");
+		return -EOPNOTSUPP;
+	}
+	if (esw->dev->shd != parent->esw->dev->shd) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot add vport to a parent belonging to a different device");
+		return -EOPNOTSUPP;
+	}
+	if (!mlx5_lag_is_active(esw->dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cross E-Switch scheduling requires LAG to be activated");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
 static int
 mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport,
 				 struct mlx5_esw_sched_node *parent,
 				 struct netlink_ext_ack *extack)
 {
 	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
-	int err = 0;
+	int err;
 
-	if (parent && parent->esw != esw) {
-		NL_SET_ERR_MSG_MOD(extack, "Cross E-Switch scheduling is not supported");
-		return -EOPNOTSUPP;
-	}
+	err = mlx5_esw_validate_cross_esw_scheduling(esw, parent, extack);
+	if (err)
+		return err;
 
 	if (!vport->qos.sched_node && parent) {
 		enum sched_node_type type;
-- 
2.44.0