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/slab.h>
17 /* This tag length is 4 bytes, older ones were 6 bytes, we do not
20 #define BRCM_TAG_LEN 4
22 /* Tag is constructed and desconstructed using byte by byte access
23 * because the tag is placed after the MAC Source Address, which does
24 * not make it 4-bytes aligned, so this might cause unaligned accesses
25 * on most systems where this is used.
28 /* Ingress and egress opcodes */
29 #define BRCM_OPCODE_SHIFT 5
30 #define BRCM_OPCODE_MASK 0x7
33 /* 1st byte in the tag */
34 #define BRCM_IG_TC_SHIFT 2
35 #define BRCM_IG_TC_MASK 0x7
36 /* 2nd byte in the tag */
37 #define BRCM_IG_TE_MASK 0x3
38 #define BRCM_IG_TS_SHIFT 7
39 /* 3rd byte in the tag */
40 #define BRCM_IG_DSTMAP2_MASK 1
41 #define BRCM_IG_DSTMAP1_MASK 0xff
45 /* 2nd byte in the tag */
46 #define BRCM_EG_CID_MASK 0xff
48 /* 3rd byte in the tag */
49 #define BRCM_EG_RC_MASK 0xff
50 #define BRCM_EG_RC_RSVD (3 << 6)
51 #define BRCM_EG_RC_EXCEPTION (1 << 5)
52 #define BRCM_EG_RC_PROT_SNOOP (1 << 4)
53 #define BRCM_EG_RC_PROT_TERM (1 << 3)
54 #define BRCM_EG_RC_SWITCH (1 << 2)
55 #define BRCM_EG_RC_MAC_LEARN (1 << 1)
56 #define BRCM_EG_RC_MIRROR (1 << 0)
57 #define BRCM_EG_TC_SHIFT 5
58 #define BRCM_EG_TC_MASK 0x7
59 #define BRCM_EG_PID_MASK 0x1f
61 static netdev_tx_t brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev)
63 struct dsa_slave_priv *p = netdev_priv(dev);
66 dev->stats.tx_packets++;
67 dev->stats.tx_bytes += skb->len;
69 if (skb_cow_head(skb, BRCM_TAG_LEN) < 0)
72 skb_push(skb, BRCM_TAG_LEN);
74 memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN);
76 /* Build the tag after the MAC Source Address */
77 brcm_tag = skb->data + 2 * ETH_ALEN;
79 /* Set the ingress opcode, traffic class, tag enforcment is
82 brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
83 ((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK);
87 brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
88 brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK;
90 /* Queue the SKB for transmission on the parent interface, but
91 * do not modify its EtherType
93 skb->dev = p->parent->dst->master_netdev;
103 static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
104 struct packet_type *pt, struct net_device *orig_dev)
106 struct dsa_switch_tree *dst = dev->dsa_ptr;
107 struct dsa_switch *ds;
111 if (unlikely(dst == NULL))
116 skb = skb_unshare(skb, GFP_ATOMIC);
120 if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
123 /* skb->data points to the EtherType, the tag is right before it */
124 brcm_tag = skb->data - 2;
126 /* The opcode should never be different than 0b000 */
127 if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK))
130 /* We should never see a reserved reason code without knowing how to
133 WARN_ON(brcm_tag[2] & BRCM_EG_RC_RSVD);
135 /* Locate which port this is coming from */
136 source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
138 /* Validate port against switch setup, either the port is totally */
139 if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
142 /* Remove Broadcom tag and update checksum */
143 skb_pull_rcsum(skb, BRCM_TAG_LEN);
145 /* Move the Ethernet DA and SA */
146 memmove(skb->data - ETH_HLEN,
147 skb->data - ETH_HLEN - BRCM_TAG_LEN,
150 skb_push(skb, ETH_HLEN);
151 skb->pkt_type = PACKET_HOST;
152 skb->dev = ds->ports[source_port];
153 skb->protocol = eth_type_trans(skb, skb->dev);
155 skb->dev->stats.rx_packets++;
156 skb->dev->stats.rx_bytes += skb->len;
158 netif_receive_skb(skb);
168 const struct dsa_device_ops brcm_netdev_ops = {
169 .xmit = brcm_tag_xmit,