net: dsa: keep the bridge_dev and bridge_num as part of the same structure

The main desire behind this is to provide coherent bridge information to
the fast path without locking.

For example, right now we set dp->bridge_dev and dp->bridge_num from
separate code paths, it is theoretically possible for a packet
transmission to read these two port properties consecutively and find a
bridge number which does not correspond with the bridge device.

Another desire is to start passing more complex bridge information to
dsa_switch_ops functions. For example, with FDB isolation, it is
expected that drivers will need to be passed the bridge which requested
an FDB/MDB entry to be offloaded, and along with that bridge_dev, the
associated bridge_num should be passed too, in case the driver might
want to implement an isolation scheme based on that number.

We already pass the {bridge_dev, bridge_num} pair to the TX forwarding
offload switch API, however we'd like to remove that and squash it into
the basic bridge join/leave API. So that means we need to pass this
pair to the bridge join/leave API.

During dsa_port_bridge_leave, first we unset dp->bridge_dev, then we
call the driver's .port_bridge_leave with what used to be our
dp->bridge_dev, but provided as an argument.

When bridge_dev and bridge_num get folded into a single structure, we
need to preserve this behavior in dsa_port_bridge_leave: we need a copy
of what used to be in dp->bridge.

Switch drivers check bridge membership by comparing dp->bridge_dev with
the provided bridge_dev, but now, if we provide the struct dsa_bridge as
a pointer, they cannot keep comparing dp->bridge to the provided
pointer, since this only points to an on-stack copy. To make this
obvious and prevent driver writers from forgetting and doing stupid
things, in this new API, the struct dsa_bridge is provided as a full
structure (not very large, contains an int and a pointer) instead of a
pointer. An explicit comparison function needs to be used to determine
bridge membership: dsa_port_offloads_bridge().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/b53/b53_common.c

@@ -1860,7 +1860,7 @@ int b53_mdb_del(struct dsa_switch *ds, int port,
 }
 EXPORT_SYMBOL(b53_mdb_del);
 
-int b53_br_join(struct dsa_switch *ds, int port, struct net_device *br)
+int b53_br_join(struct dsa_switch *ds, int port, struct dsa_bridge bridge)
 {
 	struct b53_device *dev = ds->priv;
 	s8 cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
@@ -1887,7 +1887,7 @@ int b53_br_join(struct dsa_switch *ds, int port, struct net_device *br)
 	b53_read16(dev, B53_PVLAN_PAGE, B53_PVLAN_PORT_MASK(port), &pvlan);
 
 	b53_for_each_port(dev, i) {
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != br)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 
 		/* Add this local port to the remote port VLAN control
@@ -1911,7 +1911,7 @@ int b53_br_join(struct dsa_switch *ds, int port, struct net_device *br)
 }
 EXPORT_SYMBOL(b53_br_join);
 
-void b53_br_leave(struct dsa_switch *ds, int port, struct net_device *br)
+void b53_br_leave(struct dsa_switch *ds, int port, struct dsa_bridge bridge)
 {
 	struct b53_device *dev = ds->priv;
 	struct b53_vlan *vl = &dev->vlans[0];
@@ -1923,7 +1923,7 @@ void b53_br_leave(struct dsa_switch *ds, int port, struct net_device *br)
 
 	b53_for_each_port(dev, i) {
 		/* Don't touch the remaining ports */
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != br)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 
 		b53_read16(dev, B53_PVLAN_PAGE, B53_PVLAN_PORT_MASK(i), &reg);

drivers/net/dsa/b53/b53_priv.h

@@ -324,8 +324,8 @@ void b53_get_strings(struct dsa_switch *ds, int port, u32 stringset,
 void b53_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data);
 int b53_get_sset_count(struct dsa_switch *ds, int port, int sset);
 void b53_get_ethtool_phy_stats(struct dsa_switch *ds, int port, uint64_t *data);
-int b53_br_join(struct dsa_switch *ds, int port, struct net_device *bridge);
-void b53_br_leave(struct dsa_switch *ds, int port, struct net_device *bridge);
+int b53_br_join(struct dsa_switch *ds, int port, struct dsa_bridge bridge);
+void b53_br_leave(struct dsa_switch *ds, int port, struct dsa_bridge bridge);
 void b53_br_set_stp_state(struct dsa_switch *ds, int port, u8 state);
 void b53_br_fast_age(struct dsa_switch *ds, int port);
 int b53_br_flags_pre(struct dsa_switch *ds, int port,

drivers/net/dsa/dsa_loop.c

@@ -167,19 +167,19 @@ static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
 }
 
 static int dsa_loop_port_bridge_join(struct dsa_switch *ds, int port,
-				     struct net_device *bridge)
+				     struct dsa_bridge bridge)
 {
 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
-		__func__, port, bridge->name);
+		__func__, port, bridge.dev->name);
 
 	return 0;
 }
 
 static void dsa_loop_port_bridge_leave(struct dsa_switch *ds, int port,
-				       struct net_device *bridge)
+				       struct dsa_bridge bridge)
 {
 	dev_dbg(ds->dev, "%s: port: %d, bridge: %s\n",
-		__func__, port, bridge->name);
+		__func__, port, bridge.dev->name);
 }
 
 static void dsa_loop_port_stp_state_set(struct dsa_switch *ds, int port,

drivers/net/dsa/hirschmann/hellcreek.c

@@ -674,7 +674,7 @@ static int hellcreek_bridge_flags(struct dsa_switch *ds, int port,
 }
 
 static int hellcreek_port_bridge_join(struct dsa_switch *ds, int port,
-				      struct net_device *br)
+				      struct dsa_bridge bridge)
 {
 	struct hellcreek *hellcreek = ds->priv;
 
@@ -691,7 +691,7 @@ static int hellcreek_port_bridge_join(struct dsa_switch *ds, int port,
 }
 
 static void hellcreek_port_bridge_leave(struct dsa_switch *ds, int port,
-					struct net_device *br)
+					struct dsa_bridge bridge)
 {
 	struct hellcreek *hellcreek = ds->priv;
 

drivers/net/dsa/lan9303-core.c

@@ -1103,7 +1103,7 @@ static void lan9303_port_disable(struct dsa_switch *ds, int port)
 }
 
 static int lan9303_port_bridge_join(struct dsa_switch *ds, int port,
-				    struct net_device *br)
+				    struct dsa_bridge bridge)
 {
 	struct lan9303 *chip = ds->priv;
 
@@ -1117,7 +1117,7 @@ static int lan9303_port_bridge_join(struct dsa_switch *ds, int port,
 }
 
 static void lan9303_port_bridge_leave(struct dsa_switch *ds, int port,
-				      struct net_device *br)
+				      struct dsa_bridge bridge)
 {
 	struct lan9303 *chip = ds->priv;
 

drivers/net/dsa/lantiq_gswip.c

@@ -1146,16 +1146,17 @@ static int gswip_vlan_remove(struct gswip_priv *priv,
 }
 
 static int gswip_port_bridge_join(struct dsa_switch *ds, int port,
-				  struct net_device *bridge)
+				  struct dsa_bridge bridge)
 {
+	struct net_device *br = bridge.dev;
 	struct gswip_priv *priv = ds->priv;
 	int err;
 
 	/* When the bridge uses VLAN filtering we have to configure VLAN
 	 * specific bridges. No bridge is configured here.
 	 */
-	if (!br_vlan_enabled(bridge)) {
-		err = gswip_vlan_add_unaware(priv, bridge, port);
+	if (!br_vlan_enabled(br)) {
+		err = gswip_vlan_add_unaware(priv, br, port);
 		if (err)
 			return err;
 		priv->port_vlan_filter &= ~BIT(port);
@@ -1166,8 +1167,9 @@ static int gswip_port_bridge_join(struct dsa_switch *ds, int port,
 }
 
 static void gswip_port_bridge_leave(struct dsa_switch *ds, int port,
-				    struct net_device *bridge)
+				    struct dsa_bridge bridge)
 {
+	struct net_device *br = bridge.dev;
 	struct gswip_priv *priv = ds->priv;
 
 	gswip_add_single_port_br(priv, port, true);
@@ -1175,8 +1177,8 @@ static void gswip_port_bridge_leave(struct dsa_switch *ds, int port,
 	/* When the bridge uses VLAN filtering we have to configure VLAN
 	 * specific bridges. No bridge is configured here.
 	 */
-	if (!br_vlan_enabled(bridge))
-		gswip_vlan_remove(priv, bridge, port, 0, true, false);
+	if (!br_vlan_enabled(br))
+		gswip_vlan_remove(priv, br, port, 0, true, false);
 }
 
 static int gswip_port_vlan_prepare(struct dsa_switch *ds, int port,

drivers/net/dsa/microchip/ksz_common.c

@@ -192,7 +192,7 @@ void ksz_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *buf)
 EXPORT_SYMBOL_GPL(ksz_get_ethtool_stats);
 
 int ksz_port_bridge_join(struct dsa_switch *ds, int port,
-			 struct net_device *br)
+			 struct dsa_bridge bridge)
 {
 	/* port_stp_state_set() will be called after to put the port in
 	 * appropriate state so there is no need to do anything.
@@ -203,7 +203,7 @@ int ksz_port_bridge_join(struct dsa_switch *ds, int port,
 EXPORT_SYMBOL_GPL(ksz_port_bridge_join);
 
 void ksz_port_bridge_leave(struct dsa_switch *ds, int port,
-			   struct net_device *br)
+			   struct dsa_bridge bridge)
 {
 	/* port_stp_state_set() will be called after to put the port in
 	 * forwarding state so there is no need to do anything.

drivers/net/dsa/microchip/ksz_common.h

@@ -155,9 +155,9 @@ void ksz_mac_link_down(struct dsa_switch *ds, int port, unsigned int mode,
 int ksz_sset_count(struct dsa_switch *ds, int port, int sset);
 void ksz_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *buf);
 int ksz_port_bridge_join(struct dsa_switch *ds, int port,
-			 struct net_device *br);
+			 struct dsa_bridge bridge);
 void ksz_port_bridge_leave(struct dsa_switch *ds, int port,
-			   struct net_device *br);
+			   struct dsa_bridge bridge);
 void ksz_port_fast_age(struct dsa_switch *ds, int port);
 int ksz_port_fdb_dump(struct dsa_switch *ds, int port, dsa_fdb_dump_cb_t *cb,
 		      void *data);

drivers/net/dsa/mt7530.c

@@ -1186,7 +1186,7 @@ mt7530_port_bridge_flags(struct dsa_switch *ds, int port,
 
 static int
 mt7530_port_bridge_join(struct dsa_switch *ds, int port,
-			struct net_device *bridge)
+			struct dsa_bridge bridge)
 {
 	struct dsa_port *dp = dsa_to_port(ds, port), *other_dp;
 	u32 port_bitmap = BIT(MT7530_CPU_PORT);
@@ -1204,7 +1204,7 @@ mt7530_port_bridge_join(struct dsa_switch *ds, int port,
 		 * same bridge. If the port is disabled, port matrix is kept
 		 * and not being setup until the port becomes enabled.
 		 */
-		if (dsa_port_bridge_dev_get(other_dp) != bridge)
+		if (!dsa_port_offloads_bridge(other_dp, &bridge))
 			continue;
 
 		if (priv->ports[other_port].enable)
@@ -1303,7 +1303,7 @@ mt7530_port_set_vlan_aware(struct dsa_switch *ds, int port)
 
 static void
 mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
-			 struct net_device *bridge)
+			 struct dsa_bridge bridge)
 {
 	struct dsa_port *dp = dsa_to_port(ds, port), *other_dp;
 	struct mt7530_priv *priv = ds->priv;
@@ -1320,7 +1320,7 @@ mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
 		 * in the same bridge. If the port is disabled, port matrix
 		 * is kept and not being setup until the port becomes enabled.
 		 */
-		if (dsa_port_bridge_dev_get(other_dp) != bridge)
+		if (!dsa_port_offloads_bridge(other_dp, &bridge))
 			continue;
 
 		if (priv->ports[other_port].enable)

drivers/net/dsa/mv88e6xxx/chip.c

@@ -2410,7 +2410,7 @@ static int mv88e6xxx_port_fdb_dump(struct dsa_switch *ds, int port,
 }
 
 static int mv88e6xxx_bridge_map(struct mv88e6xxx_chip *chip,
-				struct net_device *br)
+				struct dsa_bridge bridge)
 {
 	struct dsa_switch *ds = chip->ds;
 	struct dsa_switch_tree *dst = ds->dst;
@@ -2418,7 +2418,7 @@ static int mv88e6xxx_bridge_map(struct mv88e6xxx_chip *chip,
 	int err;
 
 	list_for_each_entry(dp, &dst->ports, list) {
-		if (dsa_port_bridge_dev_get(dp) == br) {
+		if (dsa_port_offloads_bridge(dp, &bridge)) {
 			if (dp->ds == ds) {
 				/* This is a local bridge group member,
 				 * remap its Port VLAN Map.
@@ -2442,14 +2442,14 @@ static int mv88e6xxx_bridge_map(struct mv88e6xxx_chip *chip,
 }
 
 static int mv88e6xxx_port_bridge_join(struct dsa_switch *ds, int port,
-				      struct net_device *br)
+				      struct dsa_bridge bridge)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
 	mv88e6xxx_reg_lock(chip);
 
-	err = mv88e6xxx_bridge_map(chip, br);
+	err = mv88e6xxx_bridge_map(chip, bridge);
 	if (err)
 		goto unlock;
 
@@ -2464,14 +2464,14 @@ static int mv88e6xxx_port_bridge_join(struct dsa_switch *ds, int port,
 }
 
 static void mv88e6xxx_port_bridge_leave(struct dsa_switch *ds, int port,
-					struct net_device *br)
+					struct dsa_bridge bridge)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
 	mv88e6xxx_reg_lock(chip);
 
-	if (mv88e6xxx_bridge_map(chip, br) ||
+	if (mv88e6xxx_bridge_map(chip, bridge) ||
 	    mv88e6xxx_port_vlan_map(chip, port))
 		dev_err(ds->dev, "failed to remap in-chip Port VLAN\n");
 
@@ -2486,7 +2486,7 @@ static void mv88e6xxx_port_bridge_leave(struct dsa_switch *ds, int port,
 
 static int mv88e6xxx_crosschip_bridge_join(struct dsa_switch *ds,
 					   int tree_index, int sw_index,
-					   int port, struct net_device *br)
+					   int port, struct dsa_bridge bridge)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
@@ -2503,7 +2503,7 @@ static int mv88e6xxx_crosschip_bridge_join(struct dsa_switch *ds,
 
 static void mv88e6xxx_crosschip_bridge_leave(struct dsa_switch *ds,
 					     int tree_index, int sw_index,
-					     int port, struct net_device *br)
+					     int port, struct dsa_bridge bridge)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 
@@ -2535,19 +2535,17 @@ static int mv88e6xxx_map_virtual_bridge_to_pvt(struct dsa_switch *ds,
 }
 
 static int mv88e6xxx_bridge_tx_fwd_offload(struct dsa_switch *ds, int port,
-					   struct net_device *br,
-					   unsigned int bridge_num)
+					   struct dsa_bridge bridge)
 {
-	return mv88e6xxx_map_virtual_bridge_to_pvt(ds, bridge_num);
+	return mv88e6xxx_map_virtual_bridge_to_pvt(ds, bridge.num);
 }
 
 static void mv88e6xxx_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port,
-					      struct net_device *br,
-					      unsigned int bridge_num)
+					      struct dsa_bridge bridge)
 {
 	int err;
 
-	err = mv88e6xxx_map_virtual_bridge_to_pvt(ds, bridge_num);
+	err = mv88e6xxx_map_virtual_bridge_to_pvt(ds, bridge.num);
 	if (err) {
 		dev_err(ds->dev, "failed to remap cross-chip Port VLAN: %pe\n",
 			ERR_PTR(err));

drivers/net/dsa/ocelot/felix.c

@@ -706,21 +706,21 @@ static int felix_bridge_flags(struct dsa_switch *ds, int port,
 }
 
 static int felix_bridge_join(struct dsa_switch *ds, int port,
-			     struct net_device *br)
+			     struct dsa_bridge bridge)
 {
 	struct ocelot *ocelot = ds->priv;
 
-	ocelot_port_bridge_join(ocelot, port, br);
+	ocelot_port_bridge_join(ocelot, port, bridge.dev);
 
 	return 0;
 }
 
 static void felix_bridge_leave(struct dsa_switch *ds, int port,
-			       struct net_device *br)
+			       struct dsa_bridge bridge)
 {
 	struct ocelot *ocelot = ds->priv;
 
-	ocelot_port_bridge_leave(ocelot, port, br);
+	ocelot_port_bridge_leave(ocelot, port, bridge.dev);
 }
 
 static int felix_lag_join(struct dsa_switch *ds, int port,

drivers/net/dsa/qca8k.c

@@ -1810,8 +1810,8 @@ qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 		  QCA8K_PORT_LOOKUP_STATE_MASK, stp_state);
 }
 
-static int
-qca8k_port_bridge_join(struct dsa_switch *ds, int port, struct net_device *br)
+static int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
+				  struct dsa_bridge bridge)
 {
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
 	int port_mask, cpu_port;
@@ -1823,7 +1823,7 @@ qca8k_port_bridge_join(struct dsa_switch *ds, int port, struct net_device *br)
 	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
 		if (dsa_is_cpu_port(ds, i))
 			continue;
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != br)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 		/* Add this port to the portvlan mask of the other ports
 		 * in the bridge
@@ -1844,8 +1844,8 @@ qca8k_port_bridge_join(struct dsa_switch *ds, int port, struct net_device *br)
 	return ret;
 }
 
-static void
-qca8k_port_bridge_leave(struct dsa_switch *ds, int port, struct net_device *br)
+static void qca8k_port_bridge_leave(struct dsa_switch *ds, int port,
+				    struct dsa_bridge bridge)
 {
 	struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
 	int cpu_port, i;
@@ -1855,7 +1855,7 @@ qca8k_port_bridge_leave(struct dsa_switch *ds, int port, struct net_device *br)
 	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
 		if (dsa_is_cpu_port(ds, i))
 			continue;
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != br)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 		/* Remove this port to the portvlan mask of the other ports
 		 * in the bridge

drivers/net/dsa/rtl8366rb.c

@@ -1186,7 +1186,7 @@ rtl8366rb_port_disable(struct dsa_switch *ds, int port)
 
 static int
 rtl8366rb_port_bridge_join(struct dsa_switch *ds, int port,
-			   struct net_device *bridge)
+			   struct dsa_bridge bridge)
 {
 	struct realtek_smi *smi = ds->priv;
 	unsigned int port_bitmap = 0;
@@ -1198,7 +1198,7 @@ rtl8366rb_port_bridge_join(struct dsa_switch *ds, int port,
 		if (i == port)
 			continue;
 		/* Not on this bridge */
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != bridge)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 		/* Join this port to each other port on the bridge */
 		ret = regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(i),
@@ -1218,7 +1218,7 @@ rtl8366rb_port_bridge_join(struct dsa_switch *ds, int port,
 
 static void
 rtl8366rb_port_bridge_leave(struct dsa_switch *ds, int port,
-			    struct net_device *bridge)
+			    struct dsa_bridge bridge)
 {
 	struct realtek_smi *smi = ds->priv;
 	unsigned int port_bitmap = 0;
@@ -1230,7 +1230,7 @@ rtl8366rb_port_bridge_leave(struct dsa_switch *ds, int port,
 		if (i == port)
 			continue;
 		/* Not on this bridge */
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != bridge)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 		/* Remove this port from any other port on the bridge */
 		ret = regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(i),

drivers/net/dsa/sja1105/sja1105_main.c

@@ -1980,7 +1980,7 @@ static int sja1105_manage_flood_domains(struct sja1105_private *priv)
 }
 
 static int sja1105_bridge_member(struct dsa_switch *ds, int port,
-				 struct net_device *br, bool member)
+				 struct dsa_bridge bridge, bool member)
 {
 	struct sja1105_l2_forwarding_entry *l2_fwd;
 	struct sja1105_private *priv = ds->priv;
@@ -2005,7 +2005,7 @@ static int sja1105_bridge_member(struct dsa_switch *ds, int port,
 		 */
 		if (i == port)
 			continue;
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != br)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 		sja1105_port_allow_traffic(l2_fwd, i, port, member);
 		sja1105_port_allow_traffic(l2_fwd, port, i, member);
@@ -2074,15 +2074,15 @@ static void sja1105_bridge_stp_state_set(struct dsa_switch *ds, int port,
 }
 
 static int sja1105_bridge_join(struct dsa_switch *ds, int port,
-			       struct net_device *br)
+			       struct dsa_bridge bridge)
 {
-	return sja1105_bridge_member(ds, port, br, true);
+	return sja1105_bridge_member(ds, port, bridge, true);
 }
 
 static void sja1105_bridge_leave(struct dsa_switch *ds, int port,
-				 struct net_device *br)
+				 struct dsa_bridge bridge)
 {
-	sja1105_bridge_member(ds, port, br, false);
+	sja1105_bridge_member(ds, port, bridge, false);
 }
 
 #define BYTES_PER_KBIT (1000LL / 8)

drivers/net/dsa/xrs700x/xrs700x.c

@@ -501,7 +501,7 @@ static void xrs700x_mac_link_up(struct dsa_switch *ds, int port,
 }
 
 static int xrs700x_bridge_common(struct dsa_switch *ds, int port,
-				 struct net_device *bridge, bool join)
+				 struct dsa_bridge bridge, bool join)
 {
 	unsigned int i, cpu_mask = 0, mask = 0;
 	struct xrs700x *priv = ds->priv;
@@ -513,14 +513,14 @@ static int xrs700x_bridge_common(struct dsa_switch *ds, int port,
 
 		cpu_mask |= BIT(i);
 
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) == bridge)
+		if (dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 
 		mask |= BIT(i);
 	}
 
 	for (i = 0; i < ds->num_ports; i++) {
-		if (dsa_port_bridge_dev_get(dsa_to_port(ds, i)) != bridge)
+		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
 			continue;
 
 		/* 1 = Disable forwarding to the port */
@@ -540,13 +540,13 @@ static int xrs700x_bridge_common(struct dsa_switch *ds, int port,
 }
 
 static int xrs700x_bridge_join(struct dsa_switch *ds, int port,
-			       struct net_device *bridge)
+			       struct dsa_bridge bridge)
 {
 	return xrs700x_bridge_common(ds, port, bridge, true);
 }
 
 static void xrs700x_bridge_leave(struct dsa_switch *ds, int port,
-				 struct net_device *bridge)
+				 struct dsa_bridge bridge)
 {
 	xrs700x_bridge_common(ds, port, bridge, false);
 }

include/linux/dsa/8021q.h

@@ -7,6 +7,7 @@
 
 #include <linux/refcount.h>
 #include <linux/types.h>
+#include <net/dsa.h>
 
 struct dsa_switch;
 struct dsa_port;
@@ -37,12 +38,10 @@ struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
 void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id);
 
 int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port,
-					struct net_device *br,
-					unsigned int bridge_num);
+					struct dsa_bridge bridge);
 
 void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port,
-					   struct net_device *br,
-					   unsigned int bridge_num);
+					   struct dsa_bridge bridge);
 
 u16 dsa_8021q_bridge_tx_fwd_offload_vid(unsigned int bridge_num);
 

include/net/dsa.h

@@ -219,6 +219,11 @@ struct dsa_mall_tc_entry {
 	};
 };
 
+struct dsa_bridge {
+	struct net_device *dev;
+	unsigned int num;
+	refcount_t refcount;
+};
 
 struct dsa_port {
 	/* A CPU port is physically connected to a master device.
@@ -256,8 +261,7 @@ struct dsa_port {
 	/* Managed by DSA on user ports and by drivers on CPU and DSA ports */
 	bool			learning;
 	u8			stp_state;
-	struct net_device	*bridge_dev;
-	unsigned int		bridge_num;
+	struct dsa_bridge	*bridge;
 	struct devlink_port	devlink_port;
 	bool			devlink_port_setup;
 	struct phylink		*pl;
@@ -588,7 +592,7 @@ static inline bool dsa_port_is_vlan_filtering(const struct dsa_port *dp)
 static inline
 struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
 {
-	if (!dp->bridge_dev)
+	if (!dp->bridge)
 		return NULL;
 
 	if (dp->lag_dev)
@@ -602,12 +606,12 @@ struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
 static inline struct net_device *
 dsa_port_bridge_dev_get(const struct dsa_port *dp)
 {
-	return dp->bridge_dev;
+	return dp->bridge ? dp->bridge->dev : NULL;
 }
 
 static inline unsigned int dsa_port_bridge_num_get(struct dsa_port *dp)
 {
-	return dp->bridge_num;
+	return dp->bridge ? dp->bridge->num : 0;
 }
 
 static inline bool dsa_port_bridge_same(const struct dsa_port *a,
@@ -636,6 +640,12 @@ dsa_port_offloads_bridge_dev(struct dsa_port *dp,
 	return dsa_port_bridge_dev_get(dp) == bridge_dev;
 }
 
+static inline bool dsa_port_offloads_bridge(struct dsa_port *dp,
+					    const struct dsa_bridge *bridge)
+{
+	return dsa_port_bridge_dev_get(dp) == bridge->dev;
+}
+
 /* Returns true if any port of this tree offloads the given net_device */
 static inline bool dsa_tree_offloads_bridge_port(struct dsa_switch_tree *dst,
 						 const struct net_device *dev)
@@ -812,17 +822,15 @@ struct dsa_switch_ops {
 	 */
 	int	(*set_ageing_time)(struct dsa_switch *ds, unsigned int msecs);
 	int	(*port_bridge_join)(struct dsa_switch *ds, int port,
-				    struct net_device *bridge);
+				    struct dsa_bridge bridge);
 	void	(*port_bridge_leave)(struct dsa_switch *ds, int port,
-				     struct net_device *bridge);
+				     struct dsa_bridge bridge);
 	/* Called right after .port_bridge_join() */
 	int	(*port_bridge_tx_fwd_offload)(struct dsa_switch *ds, int port,
-					      struct net_device *bridge,
-					      unsigned int bridge_num);
+					      struct dsa_bridge bridge);
 	/* Called right before .port_bridge_leave() */
 	void	(*port_bridge_tx_fwd_unoffload)(struct dsa_switch *ds, int port,
-						struct net_device *bridge,
-						unsigned int bridge_num);
+						struct dsa_bridge bridge);
 	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
 				      u8 state);
 	void	(*port_fast_age)(struct dsa_switch *ds, int port);
@@ -894,10 +902,10 @@ struct dsa_switch_ops {
 	 */
 	int	(*crosschip_bridge_join)(struct dsa_switch *ds, int tree_index,
 					 int sw_index, int port,
-					 struct net_device *br);
+					 struct dsa_bridge bridge);
 	void	(*crosschip_bridge_leave)(struct dsa_switch *ds, int tree_index,
 					  int sw_index, int port,
-					  struct net_device *br);
+					  struct dsa_bridge bridge);
 	int	(*crosschip_lag_change)(struct dsa_switch *ds, int sw_index,
 					int port);
 	int	(*crosschip_lag_join)(struct dsa_switch *ds, int sw_index,

net/dsa/dsa2.c

@@ -129,20 +129,29 @@ void dsa_lag_unmap(struct dsa_switch_tree *dst, struct net_device *lag)
 	}
 }
 
+struct dsa_bridge *dsa_tree_bridge_find(struct dsa_switch_tree *dst,
+					const struct net_device *br)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_bridge_dev_get(dp) == br)
+			return dp->bridge;
+
+	return NULL;
+}
+
 static int dsa_bridge_num_find(const struct net_device *bridge_dev)
 {
 	struct dsa_switch_tree *dst;
-	struct dsa_port *dp;
 
-	/* When preparing the offload for a port, it will have a valid
-	 * dp->bridge_dev pointer but a not yet valid dp->bridge_num.
-	 * However there might be other ports having the same dp->bridge_dev
-	 * and a valid dp->bridge_num, so just ignore this port.
-	 */
-	list_for_each_entry(dst, &dsa_tree_list, list)
-		list_for_each_entry(dp, &dst->ports, list)
-			if (dp->bridge_dev == bridge_dev && dp->bridge_num)
-				return dp->bridge_num;
+	list_for_each_entry(dst, &dsa_tree_list, list) {
+		struct dsa_bridge *bridge;
+
+		bridge = dsa_tree_bridge_find(dst, bridge_dev);
+		if (bridge)
+			return bridge->num;
+	}
 
 	return 0;
 }
@@ -151,6 +160,12 @@ unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max)
 {
 	unsigned int bridge_num = dsa_bridge_num_find(bridge_dev);
 
+	/* Switches without FDB isolation support don't get unique
+	 * bridge numbering
+	 */
+	if (!max)
+		return 0;
+
 	if (!bridge_num) {
 		/* First port that requests FDB isolation or TX forwarding
 		 * offload for this bridge
@@ -170,11 +185,11 @@ unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max)
 void dsa_bridge_num_put(const struct net_device *bridge_dev,
 			unsigned int bridge_num)
 {
-	/* Check if the bridge is still in use, otherwise it is time
-	 * to clean it up so we can reuse this bridge_num later.
+	/* Since we refcount bridges, we know that when we call this function
+	 * it is no longer in use, so we can just go ahead and remove it from
+	 * the bit mask.
 	 */
-	if (!dsa_bridge_num_find(bridge_dev))
-		clear_bit(bridge_num, &dsa_fwd_offloading_bridges);
+	clear_bit(bridge_num, &dsa_fwd_offloading_bridges);
 }
 
 struct dsa_switch *dsa_switch_find(int tree_index, int sw_index)

net/dsa/dsa_priv.h

@@ -52,7 +52,7 @@ struct dsa_notifier_ageing_time_info {
 
 /* DSA_NOTIFIER_BRIDGE_* */
 struct dsa_notifier_bridge_info {
-	struct net_device *br;
+	struct dsa_bridge bridge;
 	int tree_index;
 	int sw_index;
 	int port;
@@ -374,7 +374,7 @@ dsa_find_designated_bridge_port_by_vid(struct net_device *master, u16 vid)
 		if (dp->type != DSA_PORT_TYPE_USER)
 			continue;
 
-		if (!dp->bridge_dev)
+		if (!dp->bridge)
 			continue;
 
 		if (dp->stp_state != BR_STATE_LEARNING &&
@@ -403,7 +403,7 @@ dsa_find_designated_bridge_port_by_vid(struct net_device *master, u16 vid)
 /* If the ingress port offloads the bridge, we mark the frame as autonomously
  * forwarded by hardware, so the software bridge doesn't forward in twice, back
  * to us, because we already did. However, if we're in fallback mode and we do
- * software bridging, we are not offloading it, therefore the dp->bridge_dev
+ * software bridging, we are not offloading it, therefore the dp->bridge
  * pointer is not populated, and flooding needs to be done by software (we are
  * effectively operating in standalone ports mode).
  */
@@ -411,7 +411,7 @@ static inline void dsa_default_offload_fwd_mark(struct sk_buff *skb)
 {
 	struct dsa_port *dp = dsa_slave_to_port(skb->dev);
 
-	skb->offload_fwd_mark = !!(dp->bridge_dev);
+	skb->offload_fwd_mark = !!(dp->bridge);
 }
 
 /* Helper for removing DSA header tags from packets in the RX path.
@@ -508,6 +508,8 @@ int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
 unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max);
 void dsa_bridge_num_put(const struct net_device *bridge_dev,
 			unsigned int bridge_num);
+struct dsa_bridge *dsa_tree_bridge_find(struct dsa_switch_tree *dst,
+					const struct net_device *br);
 
 /* tag_8021q.c */
 int dsa_tag_8021q_bridge_join(struct dsa_switch *ds,

net/dsa/port.c

@@ -130,7 +130,7 @@ int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy)
 			return err;
 	}
 
-	if (!dp->bridge_dev)
+	if (!dp->bridge)
 		dsa_port_set_state_now(dp, BR_STATE_FORWARDING, false);
 
 	if (dp->pl)
@@ -158,7 +158,7 @@ void dsa_port_disable_rt(struct dsa_port *dp)
 	if (dp->pl)
 		phylink_stop(dp->pl);
 
-	if (!dp->bridge_dev)
+	if (!dp->bridge)
 		dsa_port_set_state_now(dp, BR_STATE_DISABLED, false);
 
 	if (ds->ops->port_disable)
@@ -271,36 +271,32 @@ static void dsa_port_switchdev_unsync_attrs(struct dsa_port *dp)
 }
 
 static void dsa_port_bridge_tx_fwd_unoffload(struct dsa_port *dp,
-					     struct net_device *bridge_dev,
-					     unsigned int bridge_num)
+					     struct dsa_bridge bridge)
 {
 	struct dsa_switch *ds = dp->ds;
 
 	/* No bridge TX forwarding offload => do nothing */
-	if (!ds->ops->port_bridge_tx_fwd_unoffload || !bridge_num)
+	if (!ds->ops->port_bridge_tx_fwd_unoffload || !bridge.num)
 		return;
 
 	/* Notify the chips only once the offload has been deactivated, so
 	 * that they can update their configuration accordingly.
 	 */
-	ds->ops->port_bridge_tx_fwd_unoffload(ds, dp->index, bridge_dev,
-					      bridge_num);
+	ds->ops->port_bridge_tx_fwd_unoffload(ds, dp->index, bridge);
 }
 
 static bool dsa_port_bridge_tx_fwd_offload(struct dsa_port *dp,
-					   struct net_device *bridge_dev,
-					   unsigned int bridge_num)
+					   struct dsa_bridge bridge)
 {
 	struct dsa_switch *ds = dp->ds;
 	int err;
 
 	/* FDB isolation is required for TX forwarding offload */
-	if (!ds->ops->port_bridge_tx_fwd_offload || !bridge_num)
+	if (!ds->ops->port_bridge_tx_fwd_offload || !bridge.num)
 		return false;
 
 	/* Notify the driver */
-	err = ds->ops->port_bridge_tx_fwd_offload(ds, dp->index, bridge_dev,
-						  bridge_num);
+	err = ds->ops->port_bridge_tx_fwd_offload(ds, dp->index, bridge);
 
 	return err ? false : true;
 }
@@ -310,21 +306,32 @@ static int dsa_port_bridge_create(struct dsa_port *dp,
 				  struct netlink_ext_ack *extack)
 {
 	struct dsa_switch *ds = dp->ds;
-	unsigned int bridge_num;
+	struct dsa_bridge *bridge;
 
-	dp->bridge_dev = br;
-
-	if (!ds->max_num_bridges)
+	bridge = dsa_tree_bridge_find(ds->dst, br);
+	if (bridge) {
+		refcount_inc(&bridge->refcount);
+		dp->bridge = bridge;
 		return 0;
+	}
+
+	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
+	if (!bridge)
+		return -ENOMEM;
+
+	refcount_set(&bridge->refcount, 1);
+
+	bridge->dev = br;
 
-	bridge_num = dsa_bridge_num_get(br, ds->max_num_bridges);
-	if (!bridge_num) {
+	bridge->num = dsa_bridge_num_get(br, ds->max_num_bridges);
+	if (ds->max_num_bridges && !bridge->num) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "Range of offloadable bridges exceeded");
+		kfree(bridge);
 		return -EOPNOTSUPP;
 	}
 
-	dp->bridge_num = bridge_num;
+	dp->bridge = bridge;
 
 	return 0;
 }
@@ -332,16 +339,17 @@ static int dsa_port_bridge_create(struct dsa_port *dp,
 static void dsa_port_bridge_destroy(struct dsa_port *dp,
 				    const struct net_device *br)
 {
-	struct dsa_switch *ds = dp->ds;
+	struct dsa_bridge *bridge = dp->bridge;
+
+	dp->bridge = NULL;
 
-	dp->bridge_dev = NULL;
+	if (!refcount_dec_and_test(&bridge->refcount))
+		return;
 
-	if (ds->max_num_bridges) {
-		int bridge_num = dp->bridge_num;
+	if (bridge->num)
+		dsa_bridge_num_put(br, bridge->num);
 
-		dp->bridge_num = 0;
-		dsa_bridge_num_put(br, bridge_num);
-	}
+	kfree(bridge);
 }
 
 int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br,
@@ -351,7 +359,6 @@ int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br,
 		.tree_index = dp->ds->dst->index,
 		.sw_index = dp->ds->index,
 		.port = dp->index,
-		.br = br,
 	};
 	struct net_device *dev = dp->slave;
 	struct net_device *brport_dev;
@@ -367,12 +374,12 @@ int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br,
 
 	brport_dev = dsa_port_to_bridge_port(dp);
 
+	info.bridge = *dp->bridge;
 	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_JOIN, &info);
 	if (err)
 		goto out_rollback;
 
-	tx_fwd_offload = dsa_port_bridge_tx_fwd_offload(dp, br,
-							dsa_port_bridge_num_get(dp));
+	tx_fwd_offload = dsa_port_bridge_tx_fwd_offload(dp, info.bridge);
 
 	err = switchdev_bridge_port_offload(brport_dev, dev, dp,
 					    &dsa_slave_switchdev_notifier,
@@ -415,12 +422,11 @@ void dsa_port_pre_bridge_leave(struct dsa_port *dp, struct net_device *br)
 
 void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
 {
-	unsigned int bridge_num = dsa_port_bridge_num_get(dp);
 	struct dsa_notifier_bridge_info info = {
 		.tree_index = dp->ds->dst->index,
 		.sw_index = dp->ds->index,
 		.port = dp->index,
-		.br = br,
+		.bridge = *dp->bridge,
 	};
 	int err;
 
@@ -429,7 +435,7 @@ void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
 	 */
 	dsa_port_bridge_destroy(dp, br);
 
-	dsa_port_bridge_tx_fwd_unoffload(dp, br, bridge_num);
+	dsa_port_bridge_tx_fwd_unoffload(dp, info.bridge);
 
 	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_LEAVE, &info);
 	if (err)

net/dsa/slave.c

@@ -1564,7 +1564,7 @@ static void dsa_bridge_mtu_normalization(struct dsa_port *dp)
 	if (!dp->ds->mtu_enforcement_ingress)
 		return;
 
-	if (!dp->bridge_dev)
+	if (!dp->bridge)
 		return;
 
 	INIT_LIST_HEAD(&hw_port_list);

net/dsa/switch.c

@@ -95,7 +95,7 @@ static int dsa_switch_bridge_join(struct dsa_switch *ds,
 		if (!ds->ops->port_bridge_join)
 			return -EOPNOTSUPP;
 
-		err = ds->ops->port_bridge_join(ds, info->port, info->br);
+		err = ds->ops->port_bridge_join(ds, info->port, info->bridge);
 		if (err)
 			return err;
 	}
@@ -104,7 +104,7 @@ static int dsa_switch_bridge_join(struct dsa_switch *ds,
 	    ds->ops->crosschip_bridge_join) {
 		err = ds->ops->crosschip_bridge_join(ds, info->tree_index,
 						     info->sw_index,
-						     info->port, info->br);
+						     info->port, info->bridge);
 		if (err)
 			return err;
 	}
@@ -124,19 +124,20 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 
 	if (dst->index == info->tree_index && ds->index == info->sw_index &&
 	    ds->ops->port_bridge_leave)
-		ds->ops->port_bridge_leave(ds, info->port, info->br);
+		ds->ops->port_bridge_leave(ds, info->port, info->bridge);
 
 	if ((dst->index != info->tree_index || ds->index != info->sw_index) &&
 	    ds->ops->crosschip_bridge_leave)
 		ds->ops->crosschip_bridge_leave(ds, info->tree_index,
 						info->sw_index, info->port,
-						info->br);
+						info->bridge);
 
-	if (ds->needs_standalone_vlan_filtering && !br_vlan_enabled(info->br)) {
+	if (ds->needs_standalone_vlan_filtering &&
+	    !br_vlan_enabled(info->bridge.dev)) {
 		change_vlan_filtering = true;
 		vlan_filtering = true;
 	} else if (!ds->needs_standalone_vlan_filtering &&
-		   br_vlan_enabled(info->br)) {
+		   br_vlan_enabled(info->bridge.dev)) {
 		change_vlan_filtering = true;
 		vlan_filtering = false;
 	}

net/dsa/tag_8021q.c

@@ -337,7 +337,7 @@ dsa_port_tag_8021q_bridge_match(struct dsa_port *dp,
 		return false;
 
 	if (dsa_port_is_user(dp))
-		return dsa_port_bridge_dev_get(dp) == info->br;
+		return dsa_port_offloads_bridge(dp, &info->bridge);
 
 	return false;
 }
@@ -410,10 +410,9 @@ int dsa_tag_8021q_bridge_leave(struct dsa_switch *ds,
 }
 
 int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port,
-					struct net_device *br,
-					unsigned int bridge_num)
+					struct dsa_bridge bridge)
 {
-	u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num);
+	u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge.num);
 
 	return dsa_port_tag_8021q_vlan_add(dsa_to_port(ds, port), tx_vid,
 					   true);
@@ -421,10 +420,9 @@ int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port,
 EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_tx_fwd_offload);
 
 void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port,
-					   struct net_device *br,
-					   unsigned int bridge_num)
+					   struct dsa_bridge bridge)
 {
-	u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num);
+	u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge.num);
 
 	dsa_port_tag_8021q_vlan_del(dsa_to_port(ds, port), tx_vid, true);
 }