net: dsa: mediatek: combine MediaTek tag with VLAN tag (f0af3431) · Commits · 戴 / test

net/dsa/tag_mtk.c

+29 −9

Original line number	Diff line number	Diff line
		@@ -13,10 +13,13 @@
		*/

		#include <linux/etherdevice.h>
		#include <linux/if_vlan.h>

		#include "dsa_priv.h"

		#define MTK_HDR_LEN 4
		#define MTK_HDR_XMIT_UNTAGGED 0
		#define MTK_HDR_XMIT_TAGGED_TPID_8100 1
		#define MTK_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
		#define MTK_HDR_XMIT_DP_BIT_MASK GENMASK(5, 0)

		@@ -25,20 +28,37 @@ static struct sk_buff mtk_tag_xmit(struct sk_buff skb,
		{
		struct dsa_port *dp = dsa_slave_to_port(dev);
		u8 *mtk_tag;
		bool is_vlan_skb = true;

		/* Build the special tag after the MAC Source Address. If VLAN header
		* is present, it's required that VLAN header and special tag is
		* being combined. Only in this way we can allow the switch can parse
		* the both special and VLAN tag at the same time and then look up VLAN
		* table with VID.
		*/
		if (!skb_vlan_tagged(skb)) {
		if (skb_cow_head(skb, MTK_HDR_LEN) < 0)
		return NULL;

		skb_push(skb, MTK_HDR_LEN);

		memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN);
		is_vlan_skb = false;
		}

		/* Build the tag after the MAC Source Address */
		mtk_tag = skb->data + 2 * ETH_ALEN;
		mtk_tag[0] = 0;

		/* Mark tag attribute on special tag insertion to notify hardware
		* whether that's a combined special tag with 802.1Q header.
		*/
		mtk_tag[0] = is_vlan_skb ? MTK_HDR_XMIT_TAGGED_TPID_8100 :
		MTK_HDR_XMIT_UNTAGGED;
		mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK;

		/* Tag control information is kept for 802.1Q */
		if (!is_vlan_skb) {
		mtk_tag[2] = 0;
		mtk_tag[3] = 0;
		}

		return skb;
		}