net: dsa: tag_ksz: use the dsa_xmit_port_mask() helper

The "ksz8795", "ksz9893", "ksz9477" and "lan937x" tagging protocols
populate a bit mask for the TX ports.

Unlike the others, "ksz9477" also accelerates HSR packet duplication.

Make the HSR duplication logic available generically to all 4 taggers by
using the dsa_xmit_port_mask() function to set the TX port mask.

Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251127120902.292555-6-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: vladimiroltean

net/dsa/tag_ksz.c

@@ -120,7 +120,6 @@ static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
 
 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
 {
-	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct ethhdr *hdr;
 	u8 *tag;
 
@@ -131,7 +130,7 @@ static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);
 
-	*tag = 1 << dp->index;
+	*tag = dsa_xmit_port_mask(skb, dev);
 	if (is_link_local_ether_addr(hdr->h_dest))
 		*tag |= KSZ8795_TAIL_TAG_OVERRIDE;
 
@@ -294,21 +293,12 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);
 
-	val = BIT(dp->index);
-
+	val = dsa_xmit_port_mask(skb, dev);
 	val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);
 
 	if (is_link_local_ether_addr(hdr->h_dest))
 		val |= KSZ9477_TAIL_TAG_OVERRIDE;
 
-	if (dev->features & NETIF_F_HW_HSR_DUP) {
-		struct net_device *hsr_dev = dp->hsr_dev;
-		struct dsa_port *other_dp;
-
-		dsa_hsr_foreach_port(other_dp, dp->ds, hsr_dev)
-			val |= BIT(other_dp->index);
-	}
-
 	*tag = cpu_to_be16(val);
 
 	return ksz_defer_xmit(dp, skb);
@@ -371,8 +361,7 @@ static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 	hdr = skb_eth_hdr(skb);
 
-	*tag = BIT(dp->index);
-
+	*tag = dsa_xmit_port_mask(skb, dev);
 	*tag |= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);
 
 	if (is_link_local_ether_addr(hdr->h_dest))
@@ -436,8 +425,7 @@ static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 
 	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
 
-	val = BIT(dp->index);
-
+	val = dsa_xmit_port_mask(skb, dev);
 	val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);
 
 	if (is_link_local_ether_addr(hdr->h_dest))