drivers: net: cpsw: Support ALLMULTI and fix IFF_PROMISC in switch mode

The cpsw driver did not support the IFF_ALLMULTI flag which makes dynamic
multicast routing not work. Related to this, when enabling IFF_PROMISC
in switch mode, all registered multicast addresses are flushed, resulting
in only broadcast and unicast traffic being received.

A new cpsw_ale_set_allmulti function now scans through the ALE entry
table and adds/removes the host port from the unregistered multicast
port mask of each vlan entry depending on the state of IFF_ALLMULTI.
In promiscious mode, cpsw_ale_set_allmulti is used to force reception
of all multicast traffic in addition to the unicast and broadcast traffic.

With this change dynamic multicast and promiscious mode both work in
switch mode.

Signed-off-by: Len Sorensen <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/ti/cpsw.c

···
 	if (ndev->flags & IFF_PROMISC) {
 		/* Enable promiscuous mode */
 		cpsw_set_promiscious(ndev, true);
+		cpsw_ale_set_allmulti(priv->ale, IFF_ALLMULTI);
 		return;
 	} else {
 		/* Disable promiscuous mode */
 		cpsw_set_promiscious(ndev, false);
 	}
+
+	/* Restore allmulti on vlans if necessary */
+	cpsw_ale_set_allmulti(priv->ale, priv->ndev->flags & IFF_ALLMULTI);
 
 	/* Clear all mcast from ALE */
 	cpsw_ale_flush_multicast(priv->ale, ALE_ALL_PORTS << priv->host_port);
···
 	const int port = priv->host_port;
 	u32 reg;
 	int i;
+	int unreg_mcast_mask;
 
 	reg = (priv->version == CPSW_VERSION_1) ? CPSW1_PORT_VLAN :
 	       CPSW2_PORT_VLAN;
···
 	for (i = 0; i < priv->data.slaves; i++)
 		slave_write(priv->slaves + i, vlan, reg);
 
+	if (priv->ndev->flags & IFF_ALLMULTI)
+		unreg_mcast_mask = ALE_ALL_PORTS;
+	else
+		unreg_mcast_mask = ALE_PORT_1 | ALE_PORT_2;
+
 	cpsw_ale_add_vlan(priv->ale, vlan, ALE_ALL_PORTS << port,
 			  ALE_ALL_PORTS << port, ALE_ALL_PORTS << port,
-			  (ALE_PORT_1 | ALE_PORT_2) << port);
+			  unreg_mcast_mask << port);
 }
 
 static void cpsw_init_host_port(struct cpsw_priv *priv)
···
 				unsigned short vid)
 {
 	int ret;
+	int unreg_mcast_mask;
+
+	if (priv->ndev->flags & IFF_ALLMULTI)
+		unreg_mcast_mask = ALE_ALL_PORTS;
+	else
+		unreg_mcast_mask = ALE_PORT_1 | ALE_PORT_2;
 
 	ret = cpsw_ale_add_vlan(priv->ale, vid,
 				ALE_ALL_PORTS << priv->host_port,
 				0, ALE_ALL_PORTS << priv->host_port,
-				(ALE_PORT_1 | ALE_PORT_2) << priv->host_port);
+				unreg_mcast_mask << priv->host_port);
 	if (ret != 0)
 		return ret;
 

drivers/net/ethernet/ti/cpsw_ale.c

···
 	return 0;
 }
 
+void cpsw_ale_set_allmulti(struct cpsw_ale *ale, int allmulti)
+{
+	u32 ale_entry[ALE_ENTRY_WORDS];
+	int type, idx;
+	int unreg_mcast = 0;
+
+	/* Only bother doing the work if the setting is actually changing */
+	if (ale->allmulti == allmulti)
+		return;
+
+	/* Remember the new setting to check against next time */
+	ale->allmulti = allmulti;
+
+	for (idx = 0; idx < ale->params.ale_entries; idx++) {
+		cpsw_ale_read(ale, idx, ale_entry);
+		type = cpsw_ale_get_entry_type(ale_entry);
+		if (type != ALE_TYPE_VLAN)
+			continue;
+
+		unreg_mcast = cpsw_ale_get_vlan_unreg_mcast(ale_entry);
+		if (allmulti)
+			unreg_mcast |= 1;
+		else
+			unreg_mcast &= ~1;
+		cpsw_ale_set_vlan_unreg_mcast(ale_entry, unreg_mcast);
+		cpsw_ale_write(ale, idx, ale_entry);
+	}
+}
+
 struct ale_control_info {
 	const char	*name;
 	int		offset, port_offset;

drivers/net/ethernet/ti/cpsw_ale.h

···
 	struct cpsw_ale_params	params;
 	struct timer_list	timer;
 	unsigned long		ageout;
+	int			allmulti;
 };
 
 enum cpsw_ale_control {
···
 int cpsw_ale_add_vlan(struct cpsw_ale *ale, u16 vid, int port, int untag,
 			int reg_mcast, int unreg_mcast);
 int cpsw_ale_del_vlan(struct cpsw_ale *ale, u16 vid, int port);
+void cpsw_ale_set_allmulti(struct cpsw_ale *ale, int allmulti);
 
 int cpsw_ale_control_get(struct cpsw_ale *ale, int port, int control);
 int cpsw_ale_control_set(struct cpsw_ale *ale, int port,