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Release 4.17 net/dsa/tag_mtk.c

Directory: net/dsa
/*
 * Mediatek DSA Tag support
 * Copyright (C) 2017 Landen Chao <landen.chao@mediatek.com>
 *                    Sean Wang <sean.wang@mediatek.com>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#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)


static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb, struct net_device *dev) { 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; } mtk_tag = skb->data + 2 * ETH_ALEN; /* 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; }

Contributors

PersonTokensPropCommitsCommitProp
Sean Wang14696.05%250.00%
Vivien Didelot63.95%250.00%
Total152100.00%4100.00%


static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) { int port; __be16 *phdr, hdr; if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN))) return NULL; /* The MTK header is added by the switch between src addr * and ethertype at this point, skb->data points to 2 bytes * after src addr so header should be 2 bytes right before. */ phdr = (__be16 *)(skb->data - 2); hdr = ntohs(*phdr); /* Remove MTK tag and recalculate checksum. */ skb_pull_rcsum(skb, MTK_HDR_LEN); memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - MTK_HDR_LEN, 2 * ETH_ALEN); /* Get source port information */ port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK); skb->dev = dsa_master_find_slave(dev, 0, port); if (!skb->dev) return NULL; return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Sean Wang11081.48%120.00%
Vivien Didelot2115.56%360.00%
Florian Fainelli42.96%120.00%
Total135100.00%5100.00%


static int mtk_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto, int *offset) { *offset = 4; *proto = ((__be16 *)skb->data)[1]; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Crispin44100.00%1100.00%
Total44100.00%1100.00%

const struct dsa_device_ops mtk_netdev_ops = { .xmit = mtk_tag_xmit, .rcv = mtk_tag_rcv, .flow_dissect = mtk_tag_flow_dissect, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Sean Wang30379.11%222.22%
John Crispin4912.79%111.11%
Vivien Didelot277.05%555.56%
Florian Fainelli41.04%111.11%
Florian Westphal0.00%00.00%
Total383100.00%9100.00%
Directory: net/dsa
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