Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Broadcom tag support |
| 3 | * |
| 4 | * Copyright (C) 2014 Broadcom Corporation |
| 5 | * |
| 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. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/etherdevice.h> |
| 13 | #include <linux/list.h> |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 14 | #include <linux/slab.h> |
| 15 | #include "dsa_priv.h" |
| 16 | |
| 17 | /* This tag length is 4 bytes, older ones were 6 bytes, we do not |
| 18 | * handle them |
| 19 | */ |
| 20 | #define BRCM_TAG_LEN 4 |
| 21 | |
| 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. |
| 26 | */ |
| 27 | |
| 28 | /* Ingress and egress opcodes */ |
| 29 | #define BRCM_OPCODE_SHIFT 5 |
| 30 | #define BRCM_OPCODE_MASK 0x7 |
| 31 | |
| 32 | /* Ingress fields */ |
| 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 |
| 42 | |
| 43 | /* Egress fields */ |
| 44 | |
| 45 | /* 2nd byte in the tag */ |
| 46 | #define BRCM_EG_CID_MASK 0xff |
| 47 | |
| 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 |
| 60 | |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 61 | static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev) |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 62 | { |
| 63 | struct dsa_slave_priv *p = netdev_priv(dev); |
| 64 | u8 *brcm_tag; |
| 65 | |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 66 | if (skb_cow_head(skb, BRCM_TAG_LEN) < 0) |
| 67 | goto out_free; |
| 68 | |
| 69 | skb_push(skb, BRCM_TAG_LEN); |
| 70 | |
| 71 | memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN); |
| 72 | |
| 73 | /* Build the tag after the MAC Source Address */ |
| 74 | brcm_tag = skb->data + 2 * ETH_ALEN; |
| 75 | |
| 76 | /* Set the ingress opcode, traffic class, tag enforcment is |
| 77 | * deprecated |
| 78 | */ |
| 79 | brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) | |
| 80 | ((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK); |
| 81 | brcm_tag[1] = 0; |
| 82 | brcm_tag[2] = 0; |
| 83 | if (p->port == 8) |
| 84 | brcm_tag[2] = BRCM_IG_DSTMAP2_MASK; |
| 85 | brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK; |
| 86 | |
Florian Fainelli | 5e845dc | 2020-03-22 13:58:50 -0700 | [diff] [blame] | 87 | skb->offload_fwd_mark = 1; |
| 88 | |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 89 | return skb; |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 90 | |
| 91 | out_free: |
| 92 | kfree_skb(skb); |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 93 | return NULL; |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 94 | } |
| 95 | |
| 96 | static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev, |
| 97 | struct packet_type *pt, struct net_device *orig_dev) |
| 98 | { |
| 99 | struct dsa_switch_tree *dst = dev->dsa_ptr; |
| 100 | struct dsa_switch *ds; |
| 101 | int source_port; |
| 102 | u8 *brcm_tag; |
| 103 | |
| 104 | if (unlikely(dst == NULL)) |
| 105 | goto out_drop; |
| 106 | |
| 107 | ds = dst->ds[0]; |
| 108 | |
| 109 | skb = skb_unshare(skb, GFP_ATOMIC); |
| 110 | if (skb == NULL) |
| 111 | goto out; |
| 112 | |
| 113 | if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) |
| 114 | goto out_drop; |
| 115 | |
| 116 | /* skb->data points to the EtherType, the tag is right before it */ |
| 117 | brcm_tag = skb->data - 2; |
| 118 | |
| 119 | /* The opcode should never be different than 0b000 */ |
| 120 | if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK)) |
| 121 | goto out_drop; |
| 122 | |
| 123 | /* We should never see a reserved reason code without knowing how to |
| 124 | * handle it |
| 125 | */ |
| 126 | WARN_ON(brcm_tag[2] & BRCM_EG_RC_RSVD); |
| 127 | |
| 128 | /* Locate which port this is coming from */ |
| 129 | source_port = brcm_tag[3] & BRCM_EG_PID_MASK; |
| 130 | |
| 131 | /* Validate port against switch setup, either the port is totally */ |
Andrew Lunn | c8b0980 | 2016-06-04 21:16:57 +0200 | [diff] [blame] | 132 | if (source_port >= DSA_MAX_PORTS || !ds->ports[source_port].netdev) |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 133 | goto out_drop; |
| 134 | |
| 135 | /* Remove Broadcom tag and update checksum */ |
| 136 | skb_pull_rcsum(skb, BRCM_TAG_LEN); |
| 137 | |
| 138 | /* Move the Ethernet DA and SA */ |
| 139 | memmove(skb->data - ETH_HLEN, |
| 140 | skb->data - ETH_HLEN - BRCM_TAG_LEN, |
| 141 | 2 * ETH_ALEN); |
| 142 | |
| 143 | skb_push(skb, ETH_HLEN); |
| 144 | skb->pkt_type = PACKET_HOST; |
Andrew Lunn | c8b0980 | 2016-06-04 21:16:57 +0200 | [diff] [blame] | 145 | skb->dev = ds->ports[source_port].netdev; |
Florian Fainelli | 5037d53 | 2014-08-27 17:04:55 -0700 | [diff] [blame] | 146 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 147 | |
| 148 | skb->dev->stats.rx_packets++; |
| 149 | skb->dev->stats.rx_bytes += skb->len; |
| 150 | |
| 151 | netif_receive_skb(skb); |
| 152 | |
| 153 | return 0; |
| 154 | |
| 155 | out_drop: |
| 156 | kfree_skb(skb); |
| 157 | out: |
| 158 | return 0; |
| 159 | } |
| 160 | |
| 161 | const struct dsa_device_ops brcm_netdev_ops = { |
| 162 | .xmit = brcm_tag_xmit, |
| 163 | .rcv = brcm_tag_rcv, |
| 164 | }; |