Add offloading for packet duplication supported by the YT921x switches.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/dsa/yt921x.c | 24 ++++++++++++++++++++++++
 net/dsa/tag_yt921x.c     |  4 ++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 485fec3ac74f..885a63f2b978 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -1038,6 +1038,27 @@ static int yt921x_dsa_port_max_mtu(struct dsa_switch *ds, int port)
 	return YT921X_FRAME_SIZE_MAX - ETH_HLEN - ETH_FCS_LEN - YT921X_TAG_LEN;
 }
 
+static int
+yt921x_dsa_port_hsr_leave(struct dsa_switch *ds, int port,
+			  struct net_device *hsr)
+{
+	return 0;
+}
+
+static int
+yt921x_dsa_port_hsr_join(struct dsa_switch *ds, int port,
+			 struct net_device *hsr, struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct net_device *user = dp->user;
+
+	/* Nothing special here; we natively support tx packet duplication */
+
+	user->features |= NETIF_F_HW_HSR_DUP;
+
+	return 0;
+}
+
 static int
 yt921x_mirror_del(struct yt921x_priv *priv, int port, bool ingress)
 {
@@ -2879,6 +2900,9 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
 	/* mtu */
 	.port_change_mtu	= yt921x_dsa_port_change_mtu,
 	.port_max_mtu		= yt921x_dsa_port_max_mtu,
+	/* hsr */
+	.port_hsr_leave		= yt921x_dsa_port_hsr_leave,
+	.port_hsr_join		= yt921x_dsa_port_hsr_join,
 	/* mirror */
 	.port_mirror_del	= yt921x_dsa_port_mirror_del,
 	.port_mirror_add	= yt921x_dsa_port_mirror_add,
diff --git a/net/dsa/tag_yt921x.c b/net/dsa/tag_yt921x.c
index 995da44f0a2a..0ad83924fda1 100644
--- a/net/dsa/tag_yt921x.c
+++ b/net/dsa/tag_yt921x.c
@@ -46,6 +46,7 @@ yt921x_tag_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct dsa_port *dp = dsa_user_to_port(netdev);
 	unsigned int port = dp->index;
+	struct dsa_port *partner;
 	__be16 *tag;
 	u16 tx;
 
@@ -59,6 +60,9 @@ yt921x_tag_xmit(struct sk_buff *skb, struct net_device *netdev)
 	tag[1] = 0;
 	tag[2] = 0;
 	tx = YT921X_TAG_PORT_EN | YT921X_TAG_TX_PORTn(port);
+	if (dp->hsr_dev)
+		dsa_hsr_foreach_port(partner, dp->ds, dp->hsr_dev)
+			tx |= YT921X_TAG_TX_PORTn(partner->index);
 	tag[3] = htons(tx);
 
 	return skb;
-- 
2.51.0