kernel: backport MT7530 MDB operations

Use hardware to forward multicast traffic instead of trapping to the
host.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>

diff --git a/target/linux/generic/backport-5.10/770-v5.15-net-dsa-mt7530-support-MDB-operations.patch b/target/linux/generic/backport-5.10/770-v5.15-net-dsa-mt7530-support-MDB-operations.patch
new file mode 100644 (file)
index 0000000..5d91d5a
--- /dev/null
+++ b/target/linux/generic/backport-5.10/770-v5.15-net-dsa-mt7530-support-MDB-operations.patch
@@ -0,0 +1,171 @@
+From 1f11a07a33bc26997c18b633d63f088bf75d11f2 Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Tue, 24 Aug 2021 11:37:50 +0800
+Subject: [PATCH] net: dsa: mt7530: support MDB operations
+
+This is a partial backport of commit 5a30833b9a16f8d1aa15de06636f9317ca51f9df
+("net: dsa: mt7530: support MDB and bridge flag operations") upstream.
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+---
+ drivers/net/dsa/mt7530.c | 78 ++++++++++++++++++++++++++++++++++++++--
+ net/dsa/tag_mtk.c        | 14 +-------
+ 2 files changed, 76 insertions(+), 16 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -1000,9 +1000,6 @@ mt753x_cpu_port_enable(struct dsa_switch
+       mt7530_write(priv, MT7530_PVC_P(port),
+                    PORT_SPEC_TAG);
+ 
+-      /* Unknown multicast frame forwarding to the cpu port */
+-      mt7530_rmw(priv, MT7530_MFC, UNM_FFP_MASK, UNM_FFP(BIT(port)));
+-
+       /* Set CPU port number */
+       if (priv->id == ID_MT7621)
+               mt7530_rmw(priv, MT7530_MFC, CPU_MASK, CPU_EN | CPU_PORT(port));
+@@ -1138,6 +1135,20 @@ mt7530_stp_state_set(struct dsa_switch *
+ }
+ 
+ static int
++mt7530_port_egress_floods(struct dsa_switch *ds, int port,
++                        bool unicast, bool multicast)
++{
++      struct mt7530_priv *priv = ds->priv;
++
++      mt7530_rmw(priv, MT7530_MFC,
++                 UNU_FFP(BIT(port)) | UNM_FFP(BIT(port)),
++                 (unicast ? UNU_FFP(BIT(port)) : 0) |
++                 (multicast ? UNM_FFP(BIT(port)) : 0));
++
++      return 0;
++}
++
++static int
+ mt7530_port_bridge_join(struct dsa_switch *ds, int port,
+                       struct net_device *bridge)
+ {
+@@ -1357,6 +1368,63 @@ err:
+ }
+ 
+ static int
++mt7530_port_mdb_prepare(struct dsa_switch *ds, int port,
++                      const struct switchdev_obj_port_mdb *mdb)
++{
++      return 0;
++}
++
++static void
++mt7530_port_mdb_add(struct dsa_switch *ds, int port,
++                  const struct switchdev_obj_port_mdb *mdb)
++{
++      struct mt7530_priv *priv = ds->priv;
++      const u8 *addr = mdb->addr;
++      u16 vid = mdb->vid;
++      u8 port_mask = 0;
++
++      mutex_lock(&priv->reg_mutex);
++
++      mt7530_fdb_write(priv, vid, 0, addr, 0, STATIC_EMP);
++      if (!mt7530_fdb_cmd(priv, MT7530_FDB_READ, NULL))
++              port_mask = (mt7530_read(priv, MT7530_ATRD) >> PORT_MAP)
++                          & PORT_MAP_MASK;
++
++      port_mask |= BIT(port);
++      mt7530_fdb_write(priv, vid, port_mask, addr, -1, STATIC_ENT);
++      mt7530_fdb_cmd(priv, MT7530_FDB_WRITE, NULL);
++
++      mutex_unlock(&priv->reg_mutex);
++}
++
++static int
++mt7530_port_mdb_del(struct dsa_switch *ds, int port,
++                  const struct switchdev_obj_port_mdb *mdb)
++{
++      struct mt7530_priv *priv = ds->priv;
++      const u8 *addr = mdb->addr;
++      u16 vid = mdb->vid;
++      u8 port_mask = 0;
++      int ret;
++
++      mutex_lock(&priv->reg_mutex);
++
++      mt7530_fdb_write(priv, vid, 0, addr, 0, STATIC_EMP);
++      if (!mt7530_fdb_cmd(priv, MT7530_FDB_READ, NULL))
++              port_mask = (mt7530_read(priv, MT7530_ATRD) >> PORT_MAP)
++                          & PORT_MAP_MASK;
++
++      port_mask &= ~BIT(port);
++      mt7530_fdb_write(priv, vid, port_mask, addr, -1,
++                       port_mask ? STATIC_ENT : STATIC_EMP);
++      ret = mt7530_fdb_cmd(priv, MT7530_FDB_WRITE, NULL);
++
++      mutex_unlock(&priv->reg_mutex);
++
++      return ret;
++}
++
++static int
+ mt7530_vlan_cmd(struct mt7530_priv *priv, enum mt7530_vlan_cmd cmd, u16 vid)
+ {
+       struct mt7530_dummy_poll p;
+@@ -2794,11 +2862,15 @@ static const struct dsa_switch_ops mt753
+       .port_change_mtu        = mt7530_port_change_mtu,
+       .port_max_mtu           = mt7530_port_max_mtu,
+       .port_stp_state_set     = mt7530_stp_state_set,
++      .port_egress_floods     = mt7530_port_egress_floods,
+       .port_bridge_join       = mt7530_port_bridge_join,
+       .port_bridge_leave      = mt7530_port_bridge_leave,
+       .port_fdb_add           = mt7530_port_fdb_add,
+       .port_fdb_del           = mt7530_port_fdb_del,
+       .port_fdb_dump          = mt7530_port_fdb_dump,
++      .port_mdb_prepare       = mt7530_port_mdb_prepare,
++      .port_mdb_add           = mt7530_port_mdb_add,
++      .port_mdb_del           = mt7530_port_mdb_del,
+       .port_vlan_filtering    = mt7530_port_vlan_filtering,
+       .port_vlan_prepare      = mt7530_port_vlan_prepare,
+       .port_vlan_add          = mt7530_port_vlan_add,
+--- a/net/dsa/tag_mtk.c
++++ b/net/dsa/tag_mtk.c
+@@ -24,9 +24,6 @@ static struct sk_buff *mtk_tag_xmit(stru
+       struct dsa_port *dp = dsa_slave_to_port(dev);
+       u8 xmit_tpid;
+       u8 *mtk_tag;
+-      unsigned char *dest = eth_hdr(skb)->h_dest;
+-      bool is_multicast_skb = is_multicast_ether_addr(dest) &&
+-                              !is_broadcast_ether_addr(dest);
+ 
+       /* Build the special tag after the MAC Source Address. If VLAN header
+        * is present, it's required that VLAN header and special tag is
+@@ -55,10 +52,6 @@ static struct sk_buff *mtk_tag_xmit(stru
+       mtk_tag[0] = xmit_tpid;
+       mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK;
+ 
+-      /* Disable SA learning for multicast frames */
+-      if (unlikely(is_multicast_skb))
+-              mtk_tag[1] |= MTK_HDR_XMIT_SA_DIS;
+-
+       /* Tag control information is kept for 802.1Q */
+       if (xmit_tpid == MTK_HDR_XMIT_UNTAGGED) {
+               mtk_tag[2] = 0;
+@@ -74,9 +67,6 @@ static struct sk_buff *mtk_tag_rcv(struc
+       u16 hdr;
+       int port;
+       __be16 *phdr;
+-      unsigned char *dest = eth_hdr(skb)->h_dest;
+-      bool is_multicast_skb = is_multicast_ether_addr(dest) &&
+-                              !is_broadcast_ether_addr(dest);
+ 
+       if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
+               return NULL;
+@@ -102,9 +92,7 @@ static struct sk_buff *mtk_tag_rcv(struc
+       if (!skb->dev)
+               return NULL;
+ 
+-      /* Only unicast or broadcast frames are offloaded */
+-      if (likely(!is_multicast_skb))
+-              dsa_default_offload_fwd_mark(skb);
++      dsa_default_offload_fwd_mark(skb);
+ 
+       return skb;
+ }