dpaa2-switch: unify the FDB update logic in dpaa2_switch_port_set_fdb()

For both the join and leave paths, the logic goes through the following
steps: determines which FDB should be used on a port after the current
changeupper change, populate the private port structures with the new
FDB and, if necessary, make as not used the old FDB.
Instead of having two distinct paths inside the
dpaa2_switch_port_set_fdb() for linking=true and linking=false, unify
them. This will hopefully help in making this function easier to read.

No behavior changes are expected.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://patch.msgid.link/20260610150912.1788482-6-ioana.ciornei@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 09604c84a614605fe87f2fb208077680b15b458e..45f276c2c3ec6aab519c3c819cb3ddce05865707 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -119,47 +119,35 @@ static void dpaa2_switch_port_set_fdb(struct ethsw_port_priv *port_priv,
                                      struct net_device *upper_dev,
                                      bool linking)
 {
+       struct dpaa2_switch_fdb *old_fdb = port_priv->fdb;
+       struct ethsw_core *ethsw = port_priv->ethsw_data;
        struct dpaa2_switch_fdb *new_fdb;
 
-       /* If we leave a bridge, find an unused FDB and use that. */
-       if (!linking) {
-               /* The number of FDBs is sized to accommodate all switch ports
-                * as standalone, each with its private FDB, which means that
-                * dpaa2_switch_fdb_get_unused() must succeed here. WARN if
-                * not.
-                */
-               new_fdb = dpaa2_switch_fdb_for_leave(port_priv);
-               if (WARN_ON(!new_fdb))
-                       return;
-
-               if (port_priv->fdb != new_fdb) {
-                       port_priv->fdb = new_fdb;
-                       port_priv->fdb->in_use = true;
-               }
-
-               port_priv->fdb->bridge_dev = NULL;
-
+       new_fdb = linking ? dpaa2_switch_fdb_for_join(port_priv, upper_dev) :
+                           dpaa2_switch_fdb_for_leave(port_priv);
+       /* The number of FDBs is sized to accommodate all switch ports as
+        * standalone, each with its private FDB, which means that FDB must be
+        * valid here even on the leave path. WARN if not.
+        */
+       if (WARN_ON(!new_fdb))
                return;
-       }
 
-       new_fdb = dpaa2_switch_fdb_for_join(port_priv, upper_dev);
-
-       /* The current port is about to change its FDB to the one used by the
-        * first port that joined the bridge.
-        */
-       if (port_priv->fdb != new_fdb) {
-               /* The previous FDB is about to become unused, since the
-                * interface is no longer standalone.
+       if (old_fdb != new_fdb) {
+               /* The previous FDB is about to become unused, release
+                * it if we are the last user.
                 */
-               port_priv->fdb->in_use = false;
-               port_priv->fdb->bridge_dev = NULL;
+               if (!dpaa2_switch_fdb_in_use_by_others(ethsw, port_priv->fdb,
+                                                      port_priv)) {
+                       old_fdb->in_use = false;
+                       old_fdb->bridge_dev = NULL;
+               }
 
-               /* Get a reference to the new FDB */
+               new_fdb->in_use = true;
                port_priv->fdb = new_fdb;
        }
 
        /* Keep track of the new upper bridge device */
-       port_priv->fdb->bridge_dev = upper_dev;
+       port_priv->fdb->bridge_dev = linking ? upper_dev : NULL;
 }
 
 static void dpaa2_switch_fdb_get_flood_cfg(struct ethsw_core *ethsw, u16 fdb_id,