net: ethernet: mtk_eth_soc: mtk_ppe: prefer newly added l2 flows

When a device is roaming between interfaces and a new flow entry is
created, we should assume that its output device is more up to date than
whatever entry existed already.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index f9c9f2ea42065ee301343e3d94f9afb89c968636..dd9581334b054ff21e72390cd1c622b3ad23c62e 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -635,10 +635,20 @@ void mtk_foe_entry_clear(struct mtk_ppe *ppe, struct mtk_flow_entry *entry)
 static int
 mtk_foe_entry_commit_l2(struct mtk_ppe *ppe, struct mtk_flow_entry *entry)
 {
+       struct mtk_flow_entry *prev;
+
        entry->type = MTK_FLOW_TYPE_L2;
 
-       return rhashtable_insert_fast(&ppe->l2_flows, &entry->l2_node,
-                                     mtk_flow_l2_ht_params);
+       prev = rhashtable_lookup_get_insert_fast(&ppe->l2_flows, &entry->l2_node,
+                                                mtk_flow_l2_ht_params);
+       if (likely(!prev))
+               return 0;
+
+       if (IS_ERR(prev))
+               return PTR_ERR(prev);
+
+       return rhashtable_replace_fast(&ppe->l2_flows, &prev->l2_node,
+                                      &entry->l2_node, mtk_flow_l2_ht_params);
 }
 
 int mtk_foe_entry_commit(struct mtk_ppe *ppe, struct mtk_flow_entry *entry)