[PATCH v2 net-next 06/14] net: mscc: ocelot: set up the bonding mask in a way that avoids a net_device

[Vladimir Oltean]

From: Vladimir Oltean <vladimir.olt...@nxp.com>

Since this code should be called from pure switchdev as well as from
DSA, we must find a way to determine the bonding mask not by looking
directly at the net_device lowers of the bonding interface, since those
could have different private structures.

We keep a pointer to the bonding upper interface, if present, in struct
ocelot_port. Then the bonding mask becomes the bitwise OR of all ports
that have the same bonding upper interface. This adds a duplication of
functionality with the current "lags" array, but the duplication will be
short-lived, since further patches will remove the latter completely.

Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com>
Reviewed-by: Alexandre Belloni <alexandre.bell...@bootlin.com>
---
Changes in v2:
Adapted to the merged version of the DSA API for LAG offload (i.e.
rejecting a bonding interface due to tx_type now done within the
.port_lag_join callback, caller is supposed to handle -EOPNOTSUPP).

 drivers/net/ethernet/mscc/ocelot.c | 29 ++++++++++++++++++++++-------
 include/soc/mscc/ocelot.h          |  2 ++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot.c 
b/drivers/net/ethernet/mscc/ocelot.c
index 2b542f286739..e2744b921a97 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -876,6 +876,24 @@ int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_get_ts_info);
 
+static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond)
+{
+       u32 bond_mask = 0;
+       int port;
+
+       for (port = 0; port < ocelot->num_phys_ports; port++) {
+               struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+               if (!ocelot_port)
+                       continue;
+
+               if (ocelot_port->bond == bond)
+                       bond_mask |= BIT(port);
+       }
+
+       return bond_mask;
+}
+
 void ocelot_bridge_stp_state_set(struct ocelot *ocelot, int port, u8 state)
 {
        u32 port_cfg;
@@ -1254,20 +1272,15 @@ int ocelot_port_lag_join(struct ocelot *ocelot, int 
port,
                         struct net_device *bond,
                         struct netdev_lag_upper_info *info)
 {
-       struct net_device *ndev;
        u32 bond_mask = 0;
        int lag, lp;
 
        if (info->tx_type != NETDEV_LAG_TX_TYPE_HASH)
                return -EOPNOTSUPP;
 
-       rcu_read_lock();
-       for_each_netdev_in_bond_rcu(bond, ndev) {
-               struct ocelot_port_private *priv = netdev_priv(ndev);
+       ocelot->ports[port]->bond = bond;
 
-               bond_mask |= BIT(priv->chip_port);
-       }
-       rcu_read_unlock();
+       bond_mask = ocelot_get_bond_mask(ocelot, bond);
 
        lp = __ffs(bond_mask);
 
@@ -1300,6 +1313,8 @@ void ocelot_port_lag_leave(struct ocelot *ocelot, int 
port,
        u32 port_cfg;
        int i;
 
+       ocelot->ports[port]->bond = NULL;
+
        /* Remove port from any lag */
        for (i = 0; i < ocelot->num_phys_ports; i++)
                ocelot->lags[i] &= ~BIT(port);
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index cdc33fa05660..d2c587f099c8 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -610,6 +610,8 @@ struct ocelot_port {
        phy_interface_t                 phy_mode;
 
        u8                              *xmit_template;
+
+       struct net_device               *bond;
 };
 
 struct ocelot {
-- 
2.25.1