// SPDX-License-Identifier: (GPL-2.0 OR MIT) /* * net/dsa/tag_hellcreek.c - Hirschmann Hellcreek switch tag format handling * * Copyright (C) 2019,2020 Linutronix GmbH * Author Kurt Kanzenbach <kurt@linutronix.de> * * Based on tag_ksz.c. */ #include <linux/skbuff.h> #include <net/dsa.h> #include "dsa_priv.h" #define HELLCREEK_TAG_LEN 1 static struct sk_buff *hellcreek_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); u8 *tag; /* Tag encoding */ tag = skb_put(skb, HELLCREEK_TAG_LEN); *tag = BIT(dp->index); return skb; } static struct sk_buff *hellcreek_rcv(struct sk_buff *skb, struct net_device *dev) { /* Tag decoding */ u8 *tag = skb_tail_pointer(skb) - HELLCREEK_TAG_LEN; unsigned int port = tag[0] & 0x03; skb->dev = dsa_master_find_slave(dev, 0, port); if (!skb->dev) { netdev_warn(dev, "Failed to get source port: %d\n", port); return NULL; } pskb_trim_rcsum(skb, skb->len - HELLCREEK_TAG_LEN); dsa_default_offload_fwd_mark(skb); return skb; } static const struct dsa_device_ops hellcreek_netdev_ops = { .name = "hellcreek", .proto = DSA_TAG_PROTO_HELLCREEK, .xmit = hellcreek_xmit, .rcv = hellcreek_rcv, .needed_tailroom = HELLCREEK_TAG_LEN, }; MODULE_LICENSE("Dual MIT/GPL"); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_HELLCREEK); module_dsa_tag_driver(hellcreek_netdev_ops);