[PATCH net-next 8/9] net: dsa: netc: add bridge mode support

[wei . fang]

From: Wei Fang <wei.fang@xxxxxxx>

Wire up the port_bridge_join, port_bridge_leave and port_vlan_filtering
DSA callbacks to support both VLAN-unaware and VLAN-aware bridge modes.

For VLAN-unaware bridges, each bridge instance is assigned a dedicated
internal PVID via NETC_VLAN_UNAWARE_PVID(bridge.num), counting down
from VID 4095. A VFT entry is created for this PVID with hardware MAC
learning and flood-on-miss forwarding enabled. The CPU port is included
as a VFT member so frames can reach the host. The reserved VID range is
blocked in port_vlan_add to prevent user-space conflicts.

Only one VLAN-aware bridge is supported at a time; this constraint is
enforced in port_bridge_join and port_vlan_filtering. The per-port PVID
is tracked in software and written to the BPDVR register whenever VLAN
filtering is active.

FDB operations are extended to the bridge database: when vid is zero the
VLAN-unaware PVID for the bridge is substituted. Dynamic entries learned
autonomously by the hardware are handled by falling back to a
key-element-data delete via ntmp_fdbt_delete_entry_by_keye() when an
entry is absent from the software shadow list. Internal PVIDs are
translated back to VID 0 in port_fdb_dump before reporting to
user-space.

Host flood rules are removed from the ingress port filter table when a
port joins a bridge to avoid bypassing FDB lookup and MAC learning.

Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
 drivers/net/dsa/netc/netc_main.c   | 297 +++++++++++++++++++++++++++--
 drivers/net/dsa/netc/netc_switch.h |   2 +
 2 files changed, 282 insertions(+), 17 deletions(-)

diff --git a/drivers/net/dsa/netc/netc_main.c b/drivers/net/dsa/netc/netc_main.c
index 4db42c888470..1fe3b43e0459 100644
--- a/drivers/net/dsa/netc/netc_main.c
+++ b/drivers/net/dsa/netc/netc_main.c
@@ -694,13 +694,18 @@ static int netc_port_del_fdb_entry(struct netc_port *np,
 	mutex_lock(&priv->fdbt_lock);
 
 	entry = netc_lookup_fdb_entry(priv, addr, vid);
-	if (unlikely(!entry))
-		/* Currently only single port mode is supported, MAC learning
-		 * is disabled, so there is no dynamically learned FDB entry.
-		 * We need to support deleting dynamically FDB entry when the
-		 * bridge mode is supported.
-		 */
+	/* If the entry is NULL, the specified FDB entry might be a dynamic
+	 * entry, so try to delete it through the key element data.
+	 */
+	if (!entry) {
+		struct fdbt_keye_data keye = {};
+
+		ether_addr_copy(keye.mac_addr, addr);
+		keye.fid = cpu_to_le16(vid);
+		err = ntmp_fdbt_delete_entry_by_keye(ntmp, &keye);
+
 		goto unlock_fdbt;
+	}
 
 	cfge = &entry->cfge;
 	if (unlikely(!(cfge->port_bitmap & cpu_to_le32(BIT(port)))))
@@ -1259,6 +1264,16 @@ static int netc_port_add_vlan_entry(struct netc_port *np, u16 vid,
 	entry->ect_gid = NTMP_NULL_ENTRY_ID;
 
 	bitmap_stg = BIT(index) | VFT_STG_ID(0);
+	/* If the VID is a VLAN-unaware PVID, the CPU port needs to be
+	 * a member of this VLAN.
+	 */
+	if (dsa_port_is_user(np->dp) &&
+	    vid >= NETC_VLAN_UNAWARE_PVID(priv->ds->max_num_bridges)) {
+		struct dsa_port *cpu_dp = np->dp->cpu_dp;
+
+		bitmap_stg |= BIT(cpu_dp->index);
+	}
+
 	cfg = FIELD_PREP(VFT_MLO, MLO_HW) |
 	      FIELD_PREP(VFT_MFO, MFO_NO_MATCH_FLOOD);
 
@@ -1296,11 +1311,16 @@ static int netc_port_add_vlan_entry(struct netc_port *np, u16 vid,
 	return err;
 }
 
-static bool netc_port_vlan_egress_rule_changed(struct netc_vlan_entry *entry,
+static bool netc_port_vlan_egress_rule_changed(struct netc_switch *priv,
+					       struct netc_vlan_entry *entry,
 					       int port, bool untagged)
 {
 	bool old_untagged = !!(entry->untagged_port_bitmap & BIT(port));
 
+	/* VLAN-unaware VIDs have no egress rules, so return 'false' */
+	if (entry->vid >= NETC_VLAN_UNAWARE_PVID(priv->ds->max_num_bridges))
+		return false;
+
 	return old_untagged != untagged;
 }
 
@@ -1323,7 +1343,8 @@ static int netc_port_set_vlan_entry(struct netc_port *np, u16 vid,
 	}
 
 	/* Check whether the egress VLAN rule is changed */
-	changed = netc_port_vlan_egress_rule_changed(entry, port, untagged);
+	changed = netc_port_vlan_egress_rule_changed(priv, entry, port,
+						     untagged);
 	if (changed) {
 		entry->untagged_port_bitmap ^= BIT(port);
 		err = netc_port_update_vlan_egress_rule(np, entry);
@@ -1387,6 +1408,17 @@ static int netc_port_del_vlan_entry(struct netc_port *np, u16 vid)
 	cfge = &entry->cfge;
 	vlan_port_bitmap = FIELD_GET(VFT_PORT_MEMBERSHIP,
 				     le32_to_cpu(cfge->bitmap_stg));
+	/* If the VID is a VLAN-unaware PVID, we need to clear the CPU
+	 * port bit of vlan_port_bitmap, so that the VLAN entry can be
+	 * deleted if no user ports use this VLAN.
+	 */
+	if (dsa_port_is_user(np->dp) &&
+	    vid >= NETC_VLAN_UNAWARE_PVID(priv->ds->max_num_bridges)) {
+		struct dsa_port *cpu_dp = np->dp->cpu_dp;
+
+		vlan_port_bitmap &= ~BIT(cpu_dp->index);
+	}
+
 	/* If the VLAN only belongs to the current port */
 	if (vlan_port_bitmap == BIT(port)) {
 		err = ntmp_vft_delete_entry(&priv->ntmp, vid);
@@ -1494,17 +1526,53 @@ static int netc_port_max_mtu(struct dsa_switch *ds, int port)
 	return NETC_MAX_FRAME_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;
 }
 
+static struct net_device *netc_classify_db(struct dsa_db db)
+{
+	switch (db.type) {
+	case DSA_DB_PORT:
+		return NULL;
+	case DSA_DB_BRIDGE:
+		return db.bridge.dev;
+	default:
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+}
+
+static u16 netc_vlan_unaware_pvid(struct dsa_switch *ds,
+				  const struct net_device *br_ndev)
+{
+	struct dsa_port *dp;
+	int br_num = -1;
+
+	if (!br_ndev)
+		return NETC_STANDALONE_PVID;
+
+	dsa_switch_for_each_available_port(dp, ds) {
+		if (dsa_port_bridge_dev_get(dp) == br_ndev) {
+			br_num = dp->bridge->num;
+			break;
+		}
+	}
+
+	/* The br_num is supposed to be 1 ~ ds->max_num_bridges */
+	if (WARN_ON(br_num <= 0))
+		return NETC_STANDALONE_PVID;
+
+	return NETC_VLAN_UNAWARE_PVID(br_num);
+}
+
 static int netc_port_fdb_add(struct dsa_switch *ds, int port,
 			     const unsigned char *addr, u16 vid,
 			     struct dsa_db db)
 {
+	struct net_device *br_ndev = netc_classify_db(db);
 	struct netc_port *np = NETC_PORT(ds, port);
 
-	/* Currently, only support standalone port mode, so only
-	 * NETC_STANDALONE_PVID (= 0) is supported here.
-	 */
-	if (vid != NETC_STANDALONE_PVID)
-		return -EOPNOTSUPP;
+	if (IS_ERR(br_ndev))
+		return PTR_ERR(br_ndev);
+
+	if (!vid)
+		vid = netc_vlan_unaware_pvid(ds, br_ndev);
 
 	return netc_port_set_fdb_entry(np, addr, vid);
 }
@@ -1513,10 +1581,14 @@ static int netc_port_fdb_del(struct dsa_switch *ds, int port,
 			     const unsigned char *addr, u16 vid,
 			     struct dsa_db db)
 {
+	struct net_device *br_ndev = netc_classify_db(db);
 	struct netc_port *np = NETC_PORT(ds, port);
 
-	if (vid != NETC_STANDALONE_PVID)
-		return -EOPNOTSUPP;
+	if (IS_ERR(br_ndev))
+		return PTR_ERR(br_ndev);
+
+	if (!vid)
+		vid = netc_vlan_unaware_pvid(ds, br_ndev);
 
 	return netc_port_del_fdb_entry(np, addr, vid);
 }
@@ -1552,6 +1624,8 @@ static int netc_port_fdb_dump(struct dsa_switch *ds, int port,
 		cfg = le32_to_cpu(cfge->cfg);
 		is_static = (cfg & FDBT_DYNAMIC) ? false : true;
 		vid = le16_to_cpu(keye->fid);
+		if (vid >= NETC_VLAN_UNAWARE_PVID(ds->max_num_bridges))
+			vid = 0;
 
 		err = cb(keye->mac_addr, vid, is_static, data);
 		if (err)
@@ -1668,6 +1742,19 @@ static void netc_port_set_host_flood(struct dsa_switch *ds, int port,
 	struct netc_port *np = NETC_PORT(ds, port);
 	struct ipft_entry_data *old_host_flood;
 
+	/* Do not add host flood rule to ingress port filter table when
+	 * the port has joined a bridge. Otherwise, the ingress frames
+	 * will bypass FDB table lookup and MAC learning, so the frames
+	 * will be redirected directly to the CPU port.
+	 */
+	if (dsa_port_bridge_dev_get(np->dp)) {
+		netc_port_remove_host_flood(np, np->host_flood);
+		np->host_flood = NULL;
+		netc_port_wr(np, NETC_PIPFCR, 0);
+
+		return;
+	}
+
 	if (np->uc == uc && np->mc == mc)
 		return;
 
@@ -1689,12 +1776,81 @@ static void netc_port_set_host_flood(struct dsa_switch *ds, int port,
 	netc_port_remove_host_flood(np, old_host_flood);
 }
 
+static int netc_single_vlan_aware_bridge(struct dsa_switch *ds,
+					 struct netlink_ext_ack *extack)
+{
+	struct net_device *br_ndev = NULL;
+	struct dsa_port *dp;
+
+	dsa_switch_for_each_available_port(dp, ds) {
+		struct net_device *port_br = dsa_port_bridge_dev_get(dp);
+
+		if (!port_br || !br_vlan_enabled(port_br))
+			continue;
+
+		if (!br_ndev) {
+			br_ndev = port_br;
+			continue;
+		}
+
+		if (br_ndev == port_br)
+			continue;
+
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only one VLAN-aware bridge is supported");
+
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int netc_port_vlan_filtering(struct dsa_switch *ds,
+				    int port, bool vlan_aware,
+				    struct netlink_ext_ack *extack)
+{
+	struct netc_port *np = NETC_PORT(ds, port);
+	struct net_device *br_ndev;
+	u32 pvid, val;
+	int err;
+
+	err = netc_single_vlan_aware_bridge(ds, extack);
+	if (err)
+		return err;
+
+	br_ndev = dsa_port_bridge_dev_get(np->dp);
+	pvid = netc_vlan_unaware_pvid(ds, br_ndev);
+	if (vlan_aware) {
+		err = netc_port_del_vlan_entry(np, pvid);
+		if (err)
+			return err;
+
+		pvid = np->pvid;
+	} else {
+		err = netc_port_set_vlan_entry(np, pvid, false);
+		if (err)
+			return err;
+	}
+
+	val = (vlan_aware ? 0 : BPDVR_RXVAM) | (pvid & BPDVR_VID);
+	netc_port_rmw(np, NETC_BPDVR, BPDVR_RXVAM | BPDVR_VID, val);
+
+	return 0;
+}
+
+static void netc_port_set_pvid(struct netc_port *np, u16 pvid)
+{
+	netc_port_rmw(np, NETC_BPDVR, BPDVR_VID, pvid & BPDVR_VID);
+}
+
 static int netc_port_vlan_add(struct dsa_switch *ds, int port,
 			      const struct switchdev_obj_port_vlan *vlan,
 			      struct netlink_ext_ack *extack)
 {
 	struct netc_port *np = NETC_PORT(ds, port);
+	struct dsa_port *dp = np->dp;
 	bool untagged;
+	int err;
 
 	/* The 8021q layer may attempt to change NETC_STANDALONE_PVID
 	 * (VID 0), so we need to ignore it.
@@ -1702,20 +1858,123 @@ static int netc_port_vlan_add(struct dsa_switch *ds, int port,
 	if (vlan->vid == NETC_STANDALONE_PVID)
 		return 0;
 
+	if (vlan->vid >= NETC_VLAN_UNAWARE_PVID(ds->max_num_bridges)) {
+		NL_SET_ERR_MSG_FMT_MOD(extack,
+				       "VID %d~4095 reserved for VLAN-unaware bridge",
+				       NETC_VLAN_UNAWARE_PVID(ds->max_num_bridges));
+		return -EOPNOTSUPP;
+	}
+
 	untagged = !!(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED);
+	err = netc_port_set_vlan_entry(np, vlan->vid, untagged);
+	if (err)
+		return err;
+
+	if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {
+		np->pvid = vlan->vid;
+		if (dsa_port_is_vlan_filtering(dp))
+			netc_port_set_pvid(np, vlan->vid);
+
+		return 0;
+	}
+
+	if (np->pvid != vlan->vid)
+		return 0;
 
-	return netc_port_set_vlan_entry(np, vlan->vid, untagged);
+	/* Delete PVID */
+	np->pvid = 0;
+	if (dsa_port_is_vlan_filtering(dp))
+		netc_port_set_pvid(np, 0);
+
+	return 0;
 }
 
 static int netc_port_vlan_del(struct dsa_switch *ds, int port,
 			      const struct switchdev_obj_port_vlan *vlan)
 {
 	struct netc_port *np = NETC_PORT(ds, port);
+	int err;
 
 	if (vlan->vid == NETC_STANDALONE_PVID)
 		return 0;
 
-	return netc_port_del_vlan_entry(np, vlan->vid);
+	err = netc_port_del_vlan_entry(np, vlan->vid);
+	if (err)
+		return err;
+
+	if (np->pvid == vlan->vid) {
+		np->pvid = 0;
+
+		if (dsa_port_is_vlan_filtering(np->dp))
+			netc_port_set_pvid(np, 0);
+	}
+
+	return 0;
+}
+
+static int netc_port_bridge_join(struct dsa_switch *ds, int port,
+				 struct dsa_bridge bridge,
+				 bool *tx_fwd_offload,
+				 struct netlink_ext_ack *extack)
+{
+	struct netc_port *np = NETC_PORT(ds, port);
+	u16 vlan_unaware_pvid;
+	int err;
+
+	err = netc_single_vlan_aware_bridge(ds, extack);
+	if (err)
+		return err;
+
+	netc_port_set_mlo(np, MLO_NOT_OVERRIDE);
+
+	if (br_vlan_enabled(bridge.dev))
+		goto out;
+
+	vlan_unaware_pvid = NETC_VLAN_UNAWARE_PVID(bridge.num);
+	err = netc_port_set_vlan_entry(np, vlan_unaware_pvid, false);
+	if (err) {
+		netc_port_set_mlo(np, MLO_DISABLE);
+		return err;
+	}
+
+	netc_port_set_pvid(np, vlan_unaware_pvid);
+
+out:
+	netc_port_remove_host_flood(np, np->host_flood);
+	np->host_flood = NULL;
+	netc_port_wr(np, NETC_PIPFCR, 0);
+
+	return 0;
+}
+
+static void netc_port_bridge_leave(struct dsa_switch *ds, int port,
+				   struct dsa_bridge bridge)
+{
+	struct netc_port *np = NETC_PORT(ds, port);
+	struct net_device *ndev = np->dp->user;
+	u16 vlan_unaware_pvid;
+	bool mc, uc;
+
+	netc_port_set_mlo(np, MLO_DISABLE);
+	netc_port_set_pvid(np, NETC_STANDALONE_PVID);
+
+	uc = ndev->flags & IFF_PROMISC;
+	mc = ndev->flags & (IFF_PROMISC | IFF_ALLMULTI);
+
+	if (netc_port_add_host_flood_rule(np, uc, mc))
+		dev_warn(ds->dev,
+			 "Failed to restore host flood rule on port %d\n",
+			 port);
+
+	if (br_vlan_enabled(bridge.dev))
+		return;
+
+	vlan_unaware_pvid = NETC_VLAN_UNAWARE_PVID(bridge.num);
+	/* There is no need to check the return value even if it fails.
+	 * Because the PVID has been set to NETC_STANDALONE_PVID, the
+	 * frames will not match this VLAN entry.
+	 */
+	netc_port_del_vlan_entry(np, vlan_unaware_pvid);
 }
 
 static void netc_phylink_get_caps(struct dsa_switch *ds, int port,
@@ -1996,8 +2255,11 @@ static const struct dsa_switch_ops netc_switch_ops = {
 	.port_mdb_add			= netc_port_mdb_add,
 	.port_mdb_del			= netc_port_mdb_del,
 	.port_set_host_flood		= netc_port_set_host_flood,
+	.port_vlan_filtering		= netc_port_vlan_filtering,
 	.port_vlan_add			= netc_port_vlan_add,
 	.port_vlan_del			= netc_port_vlan_del,
+	.port_bridge_join		= netc_port_bridge_join,
+	.port_bridge_leave		= netc_port_bridge_leave,
 	.get_pause_stats		= netc_port_get_pause_stats,
 	.get_rmon_stats			= netc_port_get_rmon_stats,
 	.get_eth_ctrl_stats		= netc_port_get_eth_ctrl_stats,
@@ -2045,6 +2307,7 @@ static int netc_switch_probe(struct pci_dev *pdev,
 	ds->ops = &netc_switch_ops;
 	ds->phylink_mac_ops = &netc_phylink_mac_ops;
 	ds->fdb_isolation = true;
+	ds->max_num_bridges = priv->info->num_ports - 1;
 	ds->priv = priv;
 	priv->ds = ds;
 
diff --git a/drivers/net/dsa/netc/netc_switch.h b/drivers/net/dsa/netc/netc_switch.h
index 9ff334301fbc..982c8d3a3fbf 100644
--- a/drivers/net/dsa/netc/netc_switch.h
+++ b/drivers/net/dsa/netc/netc_switch.h
@@ -33,6 +33,7 @@
 #define NETC_MAX_FRAME_LEN		9600
 
 #define NETC_STANDALONE_PVID		0
+#define NETC_VLAN_UNAWARE_PVID(br_id)	(4096 - (br_id))
 
 /* Threshold format: MANT (bits 11:4) * 2^EXP (bits 3:0)
  * Unit: Memory words (average of 20 bytes each)
@@ -79,6 +80,7 @@ struct netc_port {
 	u16 enable:1;
 	u16 uc:1;
 	u16 mc:1;
+	u16 pvid;
 	struct ipft_entry_data *host_flood;
 };
 
-- 
2.34.1