f0af34317f
In order to let MT7530 switch can recognize well those egress packets having both special tag and VLAN tag, the information about the special tag should be carried on the existing VLAN tag. On the other hand, it's unnecessary for extra handling for ingress packets when VLAN tag is present since it is able to put the VLAN tag after the special tag and then follow the existing way to parse. Signed-off-by: Sean Wang <sean.wang@mediatek.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
113 lines
3 KiB
C
113 lines
3 KiB
C
/*
|
|
* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static int mtk_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
|
|
int *offset)
|
|
{
|
|
*offset = 4;
|
|
*proto = ((__be16 *)skb->data)[1];
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct dsa_device_ops mtk_netdev_ops = {
|
|
.xmit = mtk_tag_xmit,
|
|
.rcv = mtk_tag_rcv,
|
|
.flow_dissect = mtk_tag_flow_dissect,
|
|
};
|