diff --git a/include/net/dsa.h b/include/net/dsa.h index 6f7f5c17b532..7507d632e7c6 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -60,6 +60,7 @@ struct tc_action; #define DSA_TAG_PROTO_MXL862_VALUE 32 #define DSA_TAG_PROTO_NETC_VALUE 33 #define DSA_TAG_PROTO_KSZ8463_VALUE 34 +#define DSA_TAG_PROTO_MT7628_VALUE 35 enum dsa_tag_protocol { DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE, @@ -97,6 +98,7 @@ enum dsa_tag_protocol { DSA_TAG_PROTO_MXL862 = DSA_TAG_PROTO_MXL862_VALUE, DSA_TAG_PROTO_NETC = DSA_TAG_PROTO_NETC_VALUE, DSA_TAG_PROTO_KSZ8463 = DSA_TAG_PROTO_KSZ8463_VALUE, + DSA_TAG_PROTO_MT7628 = DSA_TAG_PROTO_MT7628_VALUE, }; struct dsa_switch; diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig index d5e725b90d78..23b4b74004ed 100644 --- a/net/dsa/Kconfig +++ b/net/dsa/Kconfig @@ -98,6 +98,12 @@ config NET_DSA_TAG_EDSA Say Y or M if you want to enable support for tagging frames for the Marvell switches which use EtherType DSA headers. +config NET_DSA_TAG_MT7628 + tristate "Tag driver for the MT7628 embedded switch" + help + Say Y or M if you want to enable support for tagging frames for the + switch embedded in the MT7628 SoC. + config NET_DSA_TAG_MTK tristate "Tag driver for Mediatek switches" help diff --git a/net/dsa/Makefile b/net/dsa/Makefile index b8c2667cd14a..d15bcf5c68f0 100644 --- a/net/dsa/Makefile +++ b/net/dsa/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o +obj-$(CONFIG_NET_DSA_TAG_MT7628) += tag_mt7628.o obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o obj-$(CONFIG_NET_DSA_TAG_MXL_862XX) += tag_mxl862xx.o obj-$(CONFIG_NET_DSA_TAG_MXL_GSW1XX) += tag_mxl-gsw1xx.o diff --git a/net/dsa/tag_mt7628.c b/net/dsa/tag_mt7628.c new file mode 100644 index 000000000000..80b50ff08e53 --- /dev/null +++ b/net/dsa/tag_mt7628.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2026, Joris Vaisvila + * MT7628 switch tag support + */ + +#include +#include +#include + +#include "tag.h" + +/* + * The MT7628 tag is encoded in the VLAN TPID field. + * On TX the lower 6 bits encode the destination port bitmask. + * On RX the lower 3 bits encode the source port number. + * + * The switch hardware will not modify the TPID of an incoming packet if it is + * already VLAN tagged. To work around this the switch is configured to always + * append a tag_8021q standalone VLAN tag for each port. That means we can + * safely strip the outer VLAN tag after parsing it. + * + * A VLAN tag is constructed on egress to target the standalone VLAN and + * destination port. + */ + +#define MT7628_TAG_NAME "mt7628" + +#define MT7628_TAG_TX_PORT GENMASK(5, 0) +#define MT7628_TAG_RX_PORT GENMASK(2, 0) +#define MT7628_TAG_LEN 4 + +static struct sk_buff *mt7628_tag_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct dsa_port *dp; + u16 xmit_vlan; + __be16 *tag; + + dp = dsa_user_to_port(dev); + xmit_vlan = dsa_tag_8021q_standalone_vid(dp); + + skb_push(skb, MT7628_TAG_LEN); + dsa_alloc_etype_header(skb, MT7628_TAG_LEN); + + tag = dsa_etype_header_pos_tx(skb); + + tag[0] = htons(ETH_P_8021Q | + FIELD_PREP(MT7628_TAG_TX_PORT, + dsa_xmit_port_mask(skb, dev))); + tag[1] = htons(xmit_vlan); + + return skb; +} + +static struct sk_buff *mt7628_tag_rcv(struct sk_buff *skb, + struct net_device *dev) +{ + __be16 *phdr; + + if (unlikely(!pskb_may_pull(skb, MT7628_TAG_LEN))) { + kfree_skb(skb); + return NULL; + } + + phdr = dsa_etype_header_pos_rx(skb); + skb->dev = + dsa_conduit_find_user(dev, 0, + FIELD_GET(MT7628_TAG_RX_PORT, ntohs(*phdr))); + if (!skb->dev) { + kfree_skb(skb); + return NULL; + } + + skb_pull_rcsum(skb, MT7628_TAG_LEN); + dsa_strip_etype_header(skb, MT7628_TAG_LEN); + dsa_default_offload_fwd_mark(skb); + return skb; +} + +static const struct dsa_device_ops mt7628_tag_ops = { + .name = MT7628_TAG_NAME, + .proto = DSA_TAG_PROTO_MT7628, + .xmit = mt7628_tag_xmit, + .rcv = mt7628_tag_rcv, + .needed_headroom = MT7628_TAG_LEN, +}; + +module_dsa_tag_driver(mt7628_tag_ops); + +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_MT7628, MT7628_TAG_NAME); +MODULE_DESCRIPTION("DSA tag driver for MT7628 switch"); +MODULE_LICENSE("GPL");