[PATCH v2 net] octeontx2-pf: reset HTB scheduler topology before freeing queues

[Ratheesh Kannoth]

HTB offload programs NIX_AF_TLxX_TOPOLOGY on QoS-allocated scheduler
queues via otx2_qos_txschq_set_parent_topology(), but teardown freed
those queues without clearing TOPOLOGY. The AF only restores PARENT and
SCHEDULE on free, so PRIO_ANCHOR/RR_PRIO settings can survive in the
shared scheduler pool and affect later allocations.

Reset TL1 through TL4 TOPOLOGY to zero on each HTB node's schq before
returning it to the AF during hierarchy teardown and cfg rollback.

Fixes: 5e6808b4c68d ("octeontx2-pf: Add support for HTB offload")
Signed-off-by: Ratheesh Kannoth <rkannoth@xxxxxxxxxxx>

---
v1 -> v2: Addressed sashiko comments
	https://sashiko.dev/#/patchset/20260821072812.2890922-1-rkannoth%40marvell.com
---
 .../net/ethernet/marvell/octeontx2/nic/qos.c  | 60 +++++++++++++++++--
 1 file changed, 56 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/qos.c b/drivers/net/ethernet/marvell/octeontx2/nic/qos.c
index 69c0911e28e9..100342b68ffa 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/qos.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/qos.c
@@ -235,6 +235,58 @@ static int otx2_qos_txschq_set_parent_topology(struct otx2_nic *pfvf,
 	return rc;
 }
 
+static int otx2_qos_reset_schq_topology(struct otx2_nic *pfvf, u16 lvl,
+					u16 schq)
+{
+	struct mbox *mbox = &pfvf->mbox;
+	struct nix_txschq_config *cfg;
+	int rc;
+
+	if (lvl < NIX_TXSCH_LVL_TL4 || lvl > NIX_TXSCH_LVL_TL1)
+		return 0;
+
+	mutex_lock(&mbox->lock);
+
+	cfg = otx2_mbox_alloc_msg_nix_txschq_cfg(mbox);
+	if (!cfg) {
+		mutex_unlock(&mbox->lock);
+		return -ENOMEM;
+	}
+
+	cfg->lvl = lvl;
+	cfg->num_regs = 1;
+
+	if (lvl == NIX_TXSCH_LVL_TL4)
+		cfg->reg[0] = NIX_AF_TL4X_TOPOLOGY(schq);
+	else if (lvl == NIX_TXSCH_LVL_TL3)
+		cfg->reg[0] = NIX_AF_TL3X_TOPOLOGY(schq);
+	else if (lvl == NIX_TXSCH_LVL_TL2)
+		cfg->reg[0] = NIX_AF_TL2X_TOPOLOGY(schq);
+	else
+		cfg->reg[0] = NIX_AF_TL1X_TOPOLOGY(schq);
+
+	cfg->regval[0] = 0;
+
+	rc = otx2_sync_mbox_msg(mbox);
+
+	mutex_unlock(&mbox->lock);
+
+	return rc;
+}
+
+static void otx2_qos_free_hw_schq(struct otx2_nic *pfvf, u16 lvl, u16 schq)
+{
+	int err;
+
+	err = otx2_qos_reset_schq_topology(pfvf, lvl, schq);
+	if (err)
+		netdev_warn(pfvf->netdev,
+			    "QoS: failed to reset topology for schq %u at level %u: %d\n",
+			    schq, lvl, err);
+
+	otx2_txschq_free_one(pfvf, lvl, schq);
+}
+
 static void otx2_qos_free_hw_node_schq(struct otx2_nic *pfvf,
 				       struct otx2_qos_node *parent)
 {
@@ -252,7 +304,7 @@ static void otx2_qos_free_hw_node(struct otx2_nic *pfvf,
 	list_for_each_entry_safe(node, tmp, &parent->child_list, list) {
 		otx2_qos_free_hw_node(pfvf, node);
 		otx2_qos_free_hw_node_schq(pfvf, node);
-		otx2_txschq_free_one(pfvf, node->level, node->schq);
+		otx2_qos_free_hw_schq(pfvf, node->level, node->schq);
 	}
 }
 
@@ -266,7 +318,7 @@ static void otx2_qos_free_hw_cfg(struct otx2_nic *pfvf,
 	otx2_qos_free_hw_node_schq(pfvf, node);
 
 	/* free node hw mappings */
-	otx2_txschq_free_one(pfvf, node->level, node->schq);
+	otx2_qos_free_hw_schq(pfvf, node->level, node->schq);
 
 	mutex_unlock(&pfvf->qos.qos_lock);
 }
@@ -913,7 +965,7 @@ static void otx2_qos_free_cfg(struct otx2_nic *pfvf, struct otx2_qos_cfg *cfg)
 	for (lvl = 0; lvl < NIX_TXSCH_LVL_CNT; lvl++) {
 		for (idx = 0; idx < cfg->schq[lvl]; idx++) {
 			schq = cfg->schq_list[lvl][idx];
-			otx2_txschq_free_one(pfvf, lvl, schq);
+			otx2_qos_free_hw_schq(pfvf, lvl, schq);
 		}
 	}
 
@@ -921,7 +973,7 @@ static void otx2_qos_free_cfg(struct otx2_nic *pfvf, struct otx2_qos_cfg *cfg)
 		for (idx = 0; idx < cfg->schq_contig[lvl]; idx++) {
 			if (cfg->schq_index_used[lvl][idx]) {
 				schq = cfg->schq_contig_list[lvl][idx];
-				otx2_txschq_free_one(pfvf, lvl, schq);
+				otx2_qos_free_hw_schq(pfvf, lvl, schq);
 			}
 		}
 	}
-- 
2.43.0