Subject: [RFC PATCH v7 08/16] net: dsa: tag_qca: add support for handling mgmt and MIB Ethernet packet

From: Ansuel Smith <[email-masked]>
Date: Sun, 23 Jan 2022 02:33:29 +0100

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

Signed-off-by: Ansuel Smith <[email-masked]>
---
 include/linux/dsa/tag_qca.h |  7 +++++++
 net/dsa/tag_qca.c           | 39 ++++++++++++++++++++++++++++++++++---
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/include/linux/dsa/tag_qca.h b/include/linux/dsa/tag_qca.h
index 87dd84e31304..de5a45f5b398 100644
--- a/include/linux/dsa/tag_qca.h
+++ b/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 */
diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
index fdaa1b322d25..dc81c72133eb 100644
--- a/net/dsa/tag_qca.c
+++ b/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"
@@ -32,11 +33,16 @@ 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;
 	u16 hdr, pk_type;
 	__be16 *phdr;
 	int port;
 	u8 ver;
 
+	tagger_data = ds->tagger_data;
+
 	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
 		return NULL;
 
@@ -51,13 +57,19 @@ 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 (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 (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);
@@ -73,9 +85,30 @@ 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,
-- 
2.33.1