net: dsa: tag_qca: add support for handling mgmt and MIB Ethernet packet

Add connect/disconnect helper to assign private struct to the DSA switch.
Add support for Ethernet mgmt and MIB if the DSA driver provide an handler
to correctly parse and elaborate the data.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/dsa/tag_qca.h

@@ -72,4 +72,11 @@ struct mib_ethhdr {
 	__be16 hdr;		/* qca hdr */
 } __packed;
 
+struct qca_tagger_data {
+	void (*rw_reg_ack_handler)(struct dsa_switch *ds,
+				   struct sk_buff *skb);
+	void (*mib_autocast_handler)(struct dsa_switch *ds,
+				     struct sk_buff *skb);
+};
+
 #endif /* __TAG_QCA_H */

net/dsa/tag_qca.c

@@ -5,6 +5,7 @@
 
 #include <linux/etherdevice.h>
 #include <linux/bitfield.h>
+#include <net/dsa.h>
 #include <linux/dsa/tag_qca.h>
 
 #include "dsa_priv.h"
@@ -32,13 +33,18 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 {
+	struct qca_tagger_data *tagger_data;
+	struct dsa_port *dp = dev->dsa_ptr;
+	struct dsa_switch *ds = dp->ds;
 	u8 ver, pk_type;
 	__be16 *phdr;
 	int port;
 	u16 hdr;
 
 	BUILD_BUG_ON(sizeof(struct qca_mgmt_ethhdr) != QCA_HDR_MGMT_HEADER_LEN + QCA_HDR_LEN);
 
+	tagger_data = ds->tagger_data;
+
 	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
 		return NULL;
 
@@ -53,13 +59,19 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 	/* Get pk type */
 	pk_type = FIELD_GET(QCA_HDR_RECV_TYPE, hdr);
 
-	/* Ethernet MDIO read/write packet */
-	if (pk_type == QCA_HDR_RECV_TYPE_RW_REG_ACK)
+	/* Ethernet mgmt read/write packet */
+	if (pk_type == QCA_HDR_RECV_TYPE_RW_REG_ACK) {
+		if (likely(tagger_data->rw_reg_ack_handler))
+			tagger_data->rw_reg_ack_handler(ds, skb);
 		return NULL;
+	}
 
 	/* Ethernet MIB counter packet */
-	if (pk_type == QCA_HDR_RECV_TYPE_MIB)
+	if (pk_type == QCA_HDR_RECV_TYPE_MIB) {
+		if (likely(tagger_data->mib_autocast_handler))
+			tagger_data->mib_autocast_handler(ds, skb);
 		return NULL;
+	}
 
 	/* Remove QCA tag and recalculate checksum */
 	skb_pull_rcsum(skb, QCA_HDR_LEN);
@@ -75,9 +87,30 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 	return skb;
 }
 
+static int qca_tag_connect(struct dsa_switch *ds)
+{
+	struct qca_tagger_data *tagger_data;
+
+	tagger_data = kzalloc(sizeof(*tagger_data), GFP_KERNEL);
+	if (!tagger_data)
+		return -ENOMEM;
+
+	ds->tagger_data = tagger_data;
+
+	return 0;
+}
+
+static void qca_tag_disconnect(struct dsa_switch *ds)
+{
+	kfree(ds->tagger_data);
+	ds->tagger_data = NULL;
+}
+
 static const struct dsa_device_ops qca_netdev_ops = {
 	.name	= "qca",
 	.proto	= DSA_TAG_PROTO_QCA,
+	.connect = qca_tag_connect,
+	.disconnect = qca_tag_disconnect,
 	.xmit	= qca_tag_xmit,
 	.rcv	= qca_tag_rcv,
 	.needed_headroom = QCA_HDR_LEN,