target/linux/bmips/patches-5.10/502-net-dsa-b53-support-tags-for-legacy-switches.patch

   1 From 3bc3d79efdff6e29b80bf35f7a56baaa36e4d8fe Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
   3 Date: Fri, 12 Mar 2021 12:35:39 +0100
   4 Subject: [PATCH] net: dsa: b53: support tags for legacy switches
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
  10 ---
  11  drivers/net/dsa/b53/Kconfig      |  1 +
  12  drivers/net/dsa/b53/b53_common.c |  6 +++
  13  include/net/dsa.h                |  2 +
  14  net/dsa/Kconfig                  |  7 +++
  15  net/dsa/tag_brcm.c               | 93 ++++++++++++++++++++++++++++++++
  16  5 files changed, 109 insertions(+)
  17
  18 --- a/drivers/net/dsa/b53/Kconfig
  19 +++ b/drivers/net/dsa/b53/Kconfig
  20 @@ -3,6 +3,7 @@ menuconfig B53
  21         tristate "Broadcom BCM53xx managed switch support"
  22         depends on NET_DSA
  23         select NET_DSA_TAG_BRCM
  24 +       select NET_DSA_TAG_BRCM_LEGACY
  25         select NET_DSA_TAG_BRCM_PREPEND
  26         help
  27           This driver adds support for Broadcom managed switch chips. It supports
  28 --- a/drivers/net/dsa/b53/b53_common.c
  29 +++ b/drivers/net/dsa/b53/b53_common.c
  30 @@ -1992,6 +1992,7 @@ static bool b53_can_enable_brcm_tags(str
  31
  32         switch (tag_protocol) {
  33         case DSA_TAG_PROTO_BRCM:
  34 +       case DSA_TAG_PROTO_BRCM_LEGACY:
  35         case DSA_TAG_PROTO_BRCM_PREPEND:
  36                 dev_warn(ds->dev,
  37                          "Port %d is stacked to Broadcom tag switch\n", port);
  38 @@ -2013,12 +2014,16 @@ enum dsa_tag_protocol b53_get_tag_protoc
  39         /* Older models (5325, 5365) support a different tag format that we do
  40          * not support in net/dsa/tag_brcm.c yet.
  41          */
  42 -       if (is5325(dev) || is5365(dev) ||
  43 -           !b53_can_enable_brcm_tags(ds, port, mprot)) {
  44 +       if (!b53_can_enable_brcm_tags(ds, port, mprot)) {
  45                 dev->tag_protocol = DSA_TAG_PROTO_NONE;
  46                 goto out;
  47         }
  48
  49 +       if (is5325(dev) || is5365(dev) || is63xx(dev)) {
  50 +               dev->tag_protocol = DSA_TAG_PROTO_BRCM_LEGACY;
  51 +               goto out;
  52 +       }
  53 +
  54         /* Broadcom BCM58xx chips have a flow accelerator on Port 8
  55          * which requires us to use the prepended Broadcom tag type
  56          */
  57 --- a/include/net/dsa.h
  58 +++ b/include/net/dsa.h
  59 @@ -45,10 +45,12 @@ struct phylink_link_state;
  60  #define DSA_TAG_PROTO_OCELOT_VALUE             15
  61  #define DSA_TAG_PROTO_AR9331_VALUE             16
  62  #define DSA_TAG_PROTO_RTL4_A_VALUE             17
  63 +#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE                22
  64
  65  enum dsa_tag_protocol {
  66         DSA_TAG_PROTO_NONE              = DSA_TAG_PROTO_NONE_VALUE,
  67         DSA_TAG_PROTO_BRCM              = DSA_TAG_PROTO_BRCM_VALUE,
  68 +       DSA_TAG_PROTO_BRCM_LEGACY       = DSA_TAG_PROTO_BRCM_LEGACY_VALUE,
  69         DSA_TAG_PROTO_BRCM_PREPEND      = DSA_TAG_PROTO_BRCM_PREPEND_VALUE,
  70         DSA_TAG_PROTO_DSA               = DSA_TAG_PROTO_DSA_VALUE,
  71         DSA_TAG_PROTO_EDSA              = DSA_TAG_PROTO_EDSA_VALUE,
  72 --- a/net/dsa/Kconfig
  73 +++ b/net/dsa/Kconfig
  74 @@ -47,6 +47,13 @@ config NET_DSA_TAG_BRCM
  75           Say Y if you want to enable support for tagging frames for the
  76           Broadcom switches which place the tag after the MAC source address.
  77
  78 +config NET_DSA_TAG_BRCM_LEGACY
  79 +       tristate "Tag driver for Broadcom legacy switches using in-frame headers"
  80 +       select NET_DSA_TAG_BRCM_COMMON
  81 +       help
  82 +         Say Y if you want to enable support for tagging frames for the
  83 +         Broadcom legacy switches which place the tag after the MAC source
  84 +         address.
  85
  86  config NET_DSA_TAG_BRCM_PREPEND
  87         tristate "Tag driver for Broadcom switches using prepended headers"
  88 --- a/net/dsa/tag_brcm.c
  89 +++ b/net/dsa/tag_brcm.c
  90 @@ -8,9 +8,23 @@
  91  #include <linux/etherdevice.h>
  92  #include <linux/list.h>
  93  #include <linux/slab.h>
  94 +#include <linux/types.h>
  95
  96  #include "dsa_priv.h"
  97
  98 +struct bcm_legacy_tag {
  99 +       uint16_t type;
 100 +#define BRCM_LEG_TYPE  0x8874
 101 +
 102 +       uint32_t tag;
 103 +#define BRCM_LEG_TAG_PORT_ID   (0xf)
 104 +#define BRCM_LEG_TAG_MULTICAST (1 << 29)
 105 +#define BRCM_LEG_TAG_EGRESS    (2 << 29)
 106 +#define BRCM_LEG_TAG_INGRESS   (3 << 29)
 107 +} __attribute__((packed));
 108 +
 109 +#define BRCM_LEG_TAG_LEN       sizeof(struct bcm_legacy_tag)
 110 +
 111  /* This tag length is 4 bytes, older ones were 6 bytes, we do not
 112   * handle them
 113   */
 114 @@ -197,6 +211,85 @@ DSA_TAG_DRIVER(brcm_netdev_ops);
 115  MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);
 116  #endif
 117
 118 +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
 119 +static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb,
 120 +                                        struct net_device *dev)
 121 +{
 122 +       struct dsa_port *dp = dsa_slave_to_port(dev);
 123 +       struct bcm_legacy_tag *brcm_tag;
 124 +
 125 +       if (skb_cow_head(skb, BRCM_LEG_TAG_LEN) < 0)
 126 +               return NULL;
 127 +
 128 +       /* The Ethernet switch we are interfaced with needs packets to be at
 129 +        * least 64 bytes (including FCS) otherwise they will be discarded when
 130 +        * they enter the switch port logic. When Broadcom tags are enabled, we
 131 +        * need to make sure that packets are at least 70 bytes
 132 +        * (including FCS and tag) because the length verification is done after
 133 +        * the Broadcom tag is stripped off the ingress packet.
 134 +        *
 135 +        * Let dsa_slave_xmit() free the SKB
 136 +        */
 137 +       if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false))
 138 +               return NULL;
 139 +
 140 +       skb_push(skb, BRCM_LEG_TAG_LEN);
 141 +
 142 +       memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN);
 143 +
 144 +       brcm_tag = (struct bcm_legacy_tag *) (skb->data + 2 * ETH_ALEN);
 145 +
 146 +       brcm_tag->type = BRCM_LEG_TYPE;
 147 +       brcm_tag->tag = BRCM_LEG_TAG_EGRESS;
 148 +       brcm_tag->tag |= dp->index & BRCM_LEG_TAG_PORT_ID;
 149 +
 150 +       return skb;
 151 +}
 152 +
 153 +
 154 +static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,
 155 +                                       struct net_device *dev,
 156 +                                       struct packet_type *pt)
 157 +{
 158 +       int source_port;
 159 +       struct bcm_legacy_tag *brcm_tag;
 160 +
 161 +       if (unlikely(!pskb_may_pull(skb, BRCM_LEG_TAG_LEN)))
 162 +               return NULL;
 163 +
 164 +       brcm_tag = (struct bcm_legacy_tag *) (skb->data - 2);
 165 +
 166 +       source_port = brcm_tag->tag & BRCM_LEG_TAG_PORT_ID;
 167 +
 168 +       skb->dev = dsa_master_find_slave(dev, 0, source_port);
 169 +       if (!skb->dev)
 170 +               return NULL;
 171 +
 172 +       /* Remove Broadcom tag and update checksum */
 173 +       skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN);
 174 +
 175 +       skb->offload_fwd_mark = 1;
 176 +
 177 +       /* Move the Ethernet DA and SA */
 178 +       memmove(skb->data - ETH_HLEN,
 179 +               skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN,
 180 +               2 * ETH_ALEN);
 181 +
 182 +       return skb;
 183 +}
 184 +
 185 +static const struct dsa_device_ops brcm_legacy_netdev_ops = {
 186 +       .name   = "brcm-legacy",
 187 +       .proto  = DSA_TAG_PROTO_BRCM_LEGACY,
 188 +       .xmit   = brcm_leg_tag_xmit,
 189 +       .rcv    = brcm_leg_tag_rcv,
 190 +       .overhead = BRCM_LEG_TAG_LEN,
 191 +};
 192 +
 193 +DSA_TAG_DRIVER(brcm_legacy_netdev_ops);
 194 +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);
 195 +#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */
 196 +
 197  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
 198  static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb,
 199                                              struct net_device *dev)
 200 @@ -229,6 +322,9 @@ static struct dsa_tag_driver *dsa_tag_dr
 201  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
 202         &DSA_TAG_DRIVER_NAME(brcm_netdev_ops),
 203  #endif
 204 +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
 205 +       &DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops),
 206 +#endif
 207  #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
 208         &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),
 209  #endif