target/linux/bmips/patches-5.10/049-v5.13-net-dsa-tag_brcm-add-support-for-legacy-tags.patch

   1 From 964dbf186eaa84d409c359ddf09c827a3fbe8228 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
   3 Date: Wed, 17 Mar 2021 11:29:26 +0100
   4 Subject: [PATCH 1/2] net: dsa: tag_brcm: add support for legacy tags
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Add support for legacy Broadcom tags, which are similar to DSA_TAG_PROTO_BRCM.
  10 These tags are used on BCM5325, BCM5365 and BCM63xx switches.
  11
  12 Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
  13 Signed-off-by: David S. Miller <davem@davemloft.net>
  14 ---
  15  include/net/dsa.h  |   2 +
  16  net/dsa/Kconfig    |   7 +++
  17  net/dsa/tag_brcm.c | 107 +++++++++++++++++++++++++++++++++++++++++++--
  18  3 files changed, 113 insertions(+), 3 deletions(-)
  19
  20 --- a/include/net/dsa.h
  21 +++ b/include/net/dsa.h
  22 @@ -45,10 +45,12 @@ struct phylink_link_state;
  23  #define DSA_TAG_PROTO_OCELOT_VALUE             15
  24  #define DSA_TAG_PROTO_AR9331_VALUE             16
  25  #define DSA_TAG_PROTO_RTL4_A_VALUE             17
  26 +#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE                22
  27
  28  enum dsa_tag_protocol {
  29         DSA_TAG_PROTO_NONE              = DSA_TAG_PROTO_NONE_VALUE,
  30         DSA_TAG_PROTO_BRCM              = DSA_TAG_PROTO_BRCM_VALUE,
  31 +       DSA_TAG_PROTO_BRCM_LEGACY       = DSA_TAG_PROTO_BRCM_LEGACY_VALUE,
  32         DSA_TAG_PROTO_BRCM_PREPEND      = DSA_TAG_PROTO_BRCM_PREPEND_VALUE,
  33         DSA_TAG_PROTO_DSA               = DSA_TAG_PROTO_DSA_VALUE,
  34         DSA_TAG_PROTO_EDSA              = DSA_TAG_PROTO_EDSA_VALUE,
  35 --- a/net/dsa/Kconfig
  36 +++ b/net/dsa/Kconfig
  37 @@ -47,6 +47,13 @@ config NET_DSA_TAG_BRCM
  38           Say Y if you want to enable support for tagging frames for the
  39           Broadcom switches which place the tag after the MAC source address.
  40
  41 +config NET_DSA_TAG_BRCM_LEGACY
  42 +       tristate "Tag driver for Broadcom legacy switches using in-frame headers"
  43 +       select NET_DSA_TAG_BRCM_COMMON
  44 +       help
  45 +         Say Y if you want to enable support for tagging frames for the
  46 +         Broadcom legacy switches which place the tag after the MAC source
  47 +         address.
  48
  49  config NET_DSA_TAG_BRCM_PREPEND
  50         tristate "Tag driver for Broadcom switches using prepended headers"
  51 --- a/net/dsa/tag_brcm.c
  52 +++ b/net/dsa/tag_brcm.c
  53 @@ -11,9 +11,26 @@
  54
  55  #include "dsa_priv.h"
  56
  57 -/* This tag length is 4 bytes, older ones were 6 bytes, we do not
  58 - * handle them
  59 - */
  60 +/* Legacy Broadcom tag (6 bytes) */
  61 +#define BRCM_LEG_TAG_LEN       6
  62 +
  63 +/* Type fields */
  64 +/* 1st byte in the tag */
  65 +#define BRCM_LEG_TYPE_HI       0x88
  66 +/* 2nd byte in the tag */
  67 +#define BRCM_LEG_TYPE_LO       0x74
  68 +
  69 +/* Tag fields */
  70 +/* 3rd byte in the tag */
  71 +#define BRCM_LEG_UNICAST       (0 << 5)
  72 +#define BRCM_LEG_MULTICAST     (1 << 5)
  73 +#define BRCM_LEG_EGRESS                (2 << 5)
  74 +#define BRCM_LEG_INGRESS       (3 << 5)
  75 +
  76 +/* 6th byte in the tag */
  77 +#define BRCM_LEG_PORT_ID       (0xf)
  78 +
  79 +/* Newer Broadcom tag (4 bytes) */
  80  #define BRCM_TAG_LEN   4
  81
  82  /* Tag is constructed and desconstructed using byte by byte access
  83 @@ -194,6 +211,87 @@ DSA_TAG_DRIVER(brcm_netdev_ops);
  84  MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);
  85  #endif
  86
  87 +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
  88 +static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb,
  89 +                                        struct net_device *dev)
  90 +{
  91 +       struct dsa_port *dp = dsa_slave_to_port(dev);
  92 +       u8 *brcm_tag;
  93 +
  94 +       /* The Ethernet switch we are interfaced with needs packets to be at
  95 +        * least 64 bytes (including FCS) otherwise they will be discarded when
  96 +        * they enter the switch port logic. When Broadcom tags are enabled, we
  97 +        * need to make sure that packets are at least 70 bytes
  98 +        * (including FCS and tag) because the length verification is done after
  99 +        * the Broadcom tag is stripped off the ingress packet.
 100 +        *
 101 +        * Let dsa_slave_xmit() free the SKB
 102 +        */
 103 +       if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false))
 104 +               return NULL;
 105 +
 106 +       skb_push(skb, BRCM_LEG_TAG_LEN);
 107 +
 108 +       memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN);
 109 +
 110 +       brcm_tag = skb->data + 2 * ETH_ALEN;
 111 +
 112 +       /* Broadcom tag type */
 113 +       brcm_tag[0] = BRCM_LEG_TYPE_HI;
 114 +       brcm_tag[1] = BRCM_LEG_TYPE_LO;
 115 +
 116 +       /* Broadcom tag value */
 117 +       brcm_tag[2] = BRCM_LEG_EGRESS;
 118 +       brcm_tag[3] = 0;
 119 +       brcm_tag[4] = 0;
 120 +       brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID;
 121 +
 122 +       return skb;
 123 +}
 124 +
 125 +static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,
 126 +                                       struct net_device *dev,
 127 +                                       struct packet_type *pt)
 128 +{
 129 +       int source_port;
 130 +       u8 *brcm_tag;
 131 +
 132 +       if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID)))
 133 +               return NULL;
 134 +
 135 +       brcm_tag = skb->data - 2;
 136 +
 137 +       source_port = brcm_tag[5] & BRCM_LEG_PORT_ID;
 138 +
 139 +       skb->dev = dsa_master_find_slave(dev, 0, source_port);
 140 +       if (!skb->dev)
 141 +               return NULL;
 142 +
 143 +       /* Remove Broadcom tag and update checksum */
 144 +       skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN);
 145 +
 146 +       skb->offload_fwd_mark = 1;
 147 +
 148 +       /* Move the Ethernet DA and SA */
 149 +       memmove(skb->data - ETH_HLEN,
 150 +               skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN,
 151 +               2 * ETH_ALEN);
 152 +
 153 +       return skb;
 154 +}
 155 +
 156 +static const struct dsa_device_ops brcm_legacy_netdev_ops = {
 157 +       .name = "brcm-legacy",
 158 +       .proto = DSA_TAG_PROTO_BRCM_LEGACY,
 159 +       .xmit = brcm_leg_tag_xmit,
 160 +       .rcv = brcm_leg_tag_rcv,
 161 +       .overhead = BRCM_LEG_TAG_LEN,
 162 +};
 163 +
 164 +DSA_TAG_DRIVER(brcm_legacy_netdev_ops);
 165 +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);
 166 +#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */
 167 +
 168  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
 169  static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb,
 170                                              struct net_device *dev)
 171 @@ -226,6 +324,9 @@ static struct dsa_tag_driver *dsa_tag_dr
 172  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
 173         &DSA_TAG_DRIVER_NAME(brcm_netdev_ops),
 174  #endif
 175 +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
 176 +       &DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops),
 177 +#endif
 178  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
 179         &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),
 180  #endif