net/mlx5: Introduce hierarchy level tracking on scheduling nodes

Add a `level` field to `mlx5_esw_sched_node` to track the hierarchy
depth of each scheduling node. This allows enforcement of the
scheduling depth constraints based on `log_esw_max_sched_depth`.

Modify `esw_qos_node_set_parent()` and `__esw_qos_alloc_node()` to
correctly assign hierarchy levels. Ensure that nodes inherit their
parent’s level incrementally.

Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1741642016-44918-3-git-send-email-tariqt@nvidia.com
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index c56027838a57263ec9a1a31b2856c36cd9421a37..959e4446327deaaa94c42df4dc9b25d20ecffda7 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -90,8 +90,22 @@ struct mlx5_esw_sched_node {
        struct list_head children;
        /* Valid only if this node is associated with a vport. */
        struct mlx5_vport *vport;
+       /* Level in the hierarchy. The root node level is 1. */
+       u8 level;
 };
 
+static void esw_qos_node_attach_to_parent(struct mlx5_esw_sched_node *node)
+{
+       if (!node->parent) {
+               /* Root children are assigned a depth level of 2. */
+               node->level = 2;
+               list_add_tail(&node->entry, &node->esw->qos.domain->nodes);
+       } else {
+               node->level = node->parent->level + 1;
+               list_add_tail(&node->entry, &node->parent->children);
+       }
+}
+
 static void
 esw_qos_node_set_parent(struct mlx5_esw_sched_node *node, struct mlx5_esw_sched_node *parent)
 {
@@ -99,6 +113,7 @@ esw_qos_node_set_parent(struct mlx5_esw_sched_node *node, struct mlx5_esw_sched_
        node->parent = parent;
        list_add_tail(&node->entry, &parent->children);
        node->esw = parent->esw;
+       node->level = parent->level + 1;
 }
 
 void mlx5_esw_qos_vport_qos_free(struct mlx5_vport *vport)
@@ -358,7 +373,6 @@ static struct mlx5_esw_sched_node *
 __esw_qos_alloc_node(struct mlx5_eswitch *esw, u32 tsar_ix, enum sched_node_type type,
                     struct mlx5_esw_sched_node *parent)
 {
-       struct list_head *parent_children;
        struct mlx5_esw_sched_node *node;
 
        node = kzalloc(sizeof(*node), GFP_KERNEL);
@@ -370,8 +384,7 @@ __esw_qos_alloc_node(struct mlx5_eswitch *esw, u32 tsar_ix, enum sched_node_type
        node->type = type;
        node->parent = parent;
        INIT_LIST_HEAD(&node->children);
-       parent_children = parent ? &parent->children : &esw->qos.domain->nodes;
-       list_add_tail(&node->entry, parent_children);
+       esw_qos_node_attach_to_parent(node);
 
        return node;
 }