4 * Copyright (C) 2014 Broadcom Corporation
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
12 #include <linux/etherdevice.h>
13 #include <linux/list.h>
14 #include <linux/netdevice.h>
15 #include <linux/slab.h>
18 /* This tag length is 4 bytes, older ones were 6 bytes, we do not
21 #define BRCM_TAG_LEN 4
23 /* Tag is constructed and desconstructed using byte by byte access
24 * because the tag is placed after the MAC Source Address, which does
25 * not make it 4-bytes aligned, so this might cause unaligned accesses
26 * on most systems where this is used.
29 /* Ingress and egress opcodes */
30 #define BRCM_OPCODE_SHIFT 5
31 #define BRCM_OPCODE_MASK 0x7
34 /* 1st byte in the tag */
35 #define BRCM_IG_TC_SHIFT 2
36 #define BRCM_IG_TC_MASK 0x7
37 /* 2nd byte in the tag */
38 #define BRCM_IG_TE_MASK 0x3
39 #define BRCM_IG_TS_SHIFT 7
40 /* 3rd byte in the tag */
41 #define BRCM_IG_DSTMAP2_MASK 1
42 #define BRCM_IG_DSTMAP1_MASK 0xff
46 /* 2nd byte in the tag */
47 #define BRCM_EG_CID_MASK 0xff
49 /* 3rd byte in the tag */
50 #define BRCM_EG_RC_MASK 0xff
51 #define BRCM_EG_RC_RSVD (3 << 6)
52 #define BRCM_EG_RC_EXCEPTION (1 << 5)
53 #define BRCM_EG_RC_PROT_SNOOP (1 << 4)
54 #define BRCM_EG_RC_PROT_TERM (1 << 3)
55 #define BRCM_EG_RC_SWITCH (1 << 2)
56 #define BRCM_EG_RC_MAC_LEARN (1 << 1)
57 #define BRCM_EG_RC_MIRROR (1 << 0)
58 #define BRCM_EG_TC_SHIFT 5
59 #define BRCM_EG_TC_MASK 0x7
60 #define BRCM_EG_PID_MASK 0x1f
62 static netdev_tx_t brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev)
64 struct dsa_slave_priv *p = netdev_priv(dev);
67 dev->stats.tx_packets++;
68 dev->stats.tx_bytes += skb->len;
70 if (skb_cow_head(skb, BRCM_TAG_LEN) < 0)
73 skb_push(skb, BRCM_TAG_LEN);
75 memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN);
77 /* Build the tag after the MAC Source Address */
78 brcm_tag = skb->data + 2 * ETH_ALEN;
80 /* Set the ingress opcode, traffic class, tag enforcment is
83 brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
84 ((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK);
88 brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
89 brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK;
91 /* Queue the SKB for transmission on the parent interface, but
92 * do not modify its EtherType
94 skb->protocol = htons(ETH_P_BRCMTAG);
95 skb->dev = p->parent->dst->master_netdev;
105 static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
106 struct packet_type *pt, struct net_device *orig_dev)
108 struct dsa_switch_tree *dst = dev->dsa_ptr;
109 struct dsa_switch *ds;
113 if (unlikely(dst == NULL))
118 skb = skb_unshare(skb, GFP_ATOMIC);
122 if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
125 /* skb->data points to the EtherType, the tag is right before it */
126 brcm_tag = skb->data - 2;
128 /* The opcode should never be different than 0b000 */
129 if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK))
132 /* We should never see a reserved reason code without knowing how to
135 WARN_ON(brcm_tag[2] & BRCM_EG_RC_RSVD);
137 /* Locate which port this is coming from */
138 source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
140 /* Validate port against switch setup, either the port is totally */
141 if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
144 /* Remove Broadcom tag and update checksum */
145 skb_pull_rcsum(skb, BRCM_TAG_LEN);
147 /* Move the Ethernet DA and SA */
148 memmove(skb->data - ETH_HLEN,
149 skb->data - ETH_HLEN - BRCM_TAG_LEN,
152 skb_push(skb, ETH_HLEN);
153 skb->pkt_type = PACKET_HOST;
154 skb->dev = ds->ports[source_port];
155 skb->protocol = eth_type_trans(skb, skb->dev);
157 skb->dev->stats.rx_packets++;
158 skb->dev->stats.rx_bytes += skb->len;
160 netif_receive_skb(skb);
170 const struct dsa_device_ops brcm_netdev_ops = {
171 .xmit = brcm_tag_xmit,