target/linux/lantiq/patches-5.10/0706-v5.18-net-lantiq-enable-jumbo-frames-on-GSWIP.patch

   1 From c40bb4fedcd6b8b6a714da5dd466eb88ed2652d1 Mon Sep 17 00:00:00 2001
   2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
   3 Date: Wed, 9 Mar 2022 00:04:57 +0100
   4 Subject: net: dsa: lantiq_gswip: enable jumbo frames on GSWIP
   5
   6 This enables non-standard MTUs on a per-port basis, with the overall
   7 frame size set based on the CPU port.
   8
   9 When the MTU is not changed, this should have no effect.
  10
  11 Long packets crash the switch with MTUs of greater than 2526, so the
  12 maximum is limited for now. Medium packets are sometimes dropped (e.g.
  13 TCP over 2477, UDP over 2516-2519, ICMP over 2526), Hence an MTU value
  14 of 2400 seems safe.
  15
  16 Signed-off-by: Thomas Nixon <tom@tomn.co.uk>
  17 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  18 Link: https://lore.kernel.org/r/20220308230457.1599237-1-olek2@wp.pl
  19 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  20 ---
  21  drivers/net/dsa/lantiq_gswip.c | 53 ++++++++++++++++++++++++++++++++++++++----
  22  1 file changed, 49 insertions(+), 4 deletions(-)
  23
  24 --- a/drivers/net/dsa/lantiq_gswip.c
  25 +++ b/drivers/net/dsa/lantiq_gswip.c
  26 @@ -213,6 +213,7 @@
  27  #define  GSWIP_MAC_CTRL_0_GMII_MII     0x0001
  28  #define  GSWIP_MAC_CTRL_0_GMII_RGMII   0x0002
  29  #define GSWIP_MAC_CTRL_2p(p)           (0x905 + ((p) * 0xC))
  30 +#define GSWIP_MAC_CTRL_2_LCHKL         BIT(2) /* Frame Length Check Long Enable */
  31  #define GSWIP_MAC_CTRL_2_MLEN          BIT(3) /* Maximum Untagged Frame Lnegth */
  32
  33  /* Ethernet Switch Fetch DMA Port Control Register */
  34 @@ -239,6 +240,15 @@
  35
  36  #define XRX200_GPHY_FW_ALIGN   (16 * 1024)
  37
  38 +/* Maximum packet size supported by the switch. In theory this should be 10240,
  39 + * but long packets currently cause lock-ups with an MTU of over 2526. Medium
  40 + * packets are sometimes dropped (e.g. TCP over 2477, UDP over 2516-2519, ICMP
  41 + * over 2526), hence an MTU value of 2400 seems safe. This issue only affects
  42 + * packet reception. This is probably caused by the PPA engine, which is on the
  43 + * RX part of the device. Packet transmission works properly up to 10240.
  44 + */
  45 +#define GSWIP_MAX_PACKET_LENGTH        2400
  46 +
  47  struct gswip_hw_info {
  48         int max_ports;
  49         int cpu_port;
  50 @@ -858,10 +868,6 @@ static int gswip_setup(struct dsa_switch
  51         gswip_switch_mask(priv, 0, GSWIP_PCE_PCTRL_0_INGRESS,
  52                           GSWIP_PCE_PCTRL_0p(cpu_port));
  53
  54 -       gswip_switch_mask(priv, 0, GSWIP_MAC_CTRL_2_MLEN,
  55 -                         GSWIP_MAC_CTRL_2p(cpu_port));
  56 -       gswip_switch_w(priv, VLAN_ETH_FRAME_LEN + 8 + ETH_FCS_LEN,
  57 -                      GSWIP_MAC_FLEN);
  58         gswip_switch_mask(priv, 0, GSWIP_BM_QUEUE_GCTRL_GL_MOD,
  59                           GSWIP_BM_QUEUE_GCTRL);
  60
  61 @@ -878,6 +884,8 @@ static int gswip_setup(struct dsa_switch
  62                 return err;
  63         }
  64
  65 +       ds->mtu_enforcement_ingress = true;
  66 +
  67         gswip_port_enable(ds, cpu_port, NULL);
  68         return 0;
  69  }
  70 @@ -1472,6 +1480,39 @@ static void gswip_phylink_set_capab(unsi
  71                    __ETHTOOL_LINK_MODE_MASK_NBITS);
  72  }
  73
  74 +static int gswip_port_max_mtu(struct dsa_switch *ds, int port)
  75 +{
  76 +       /* Includes 8 bytes for special header. */
  77 +       return GSWIP_MAX_PACKET_LENGTH - VLAN_ETH_HLEN - ETH_FCS_LEN;
  78 +}
  79 +
  80 +static int gswip_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
  81 +{
  82 +       struct gswip_priv *priv = ds->priv;
  83 +       int cpu_port = priv->hw_info->cpu_port;
  84 +
  85 +       /* CPU port always has maximum mtu of user ports, so use it to set
  86 +        * switch frame size, including 8 byte special header.
  87 +        */
  88 +       if (port == cpu_port) {
  89 +               new_mtu += 8;
  90 +               gswip_switch_w(priv, VLAN_ETH_HLEN + new_mtu + ETH_FCS_LEN,
  91 +                              GSWIP_MAC_FLEN);
  92 +       }
  93 +
  94 +       /* Enable MLEN for ports with non-standard MTUs, including the special
  95 +        * header on the CPU port added above.
  96 +        */
  97 +       if (new_mtu != ETH_DATA_LEN)
  98 +               gswip_switch_mask(priv, 0, GSWIP_MAC_CTRL_2_MLEN,
  99 +                                 GSWIP_MAC_CTRL_2p(port));
 100 +       else
 101 +               gswip_switch_mask(priv, GSWIP_MAC_CTRL_2_MLEN, 0,
 102 +                                 GSWIP_MAC_CTRL_2p(port));
 103 +
 104 +       return 0;
 105 +}
 106 +
 107  static void gswip_xrx200_phylink_validate(struct dsa_switch *ds, int port,
 108                                           unsigned long *supported,
 109                                           struct phylink_link_state *state)
 110 @@ -1829,6 +1870,8 @@ static const struct dsa_switch_ops gswip
 111         .port_fdb_add           = gswip_port_fdb_add,
 112         .port_fdb_del           = gswip_port_fdb_del,
 113         .port_fdb_dump          = gswip_port_fdb_dump,
 114 +       .port_change_mtu        = gswip_port_change_mtu,
 115 +       .port_max_mtu           = gswip_port_max_mtu,
 116         .phylink_validate       = gswip_xrx200_phylink_validate,
 117         .phylink_mac_config     = gswip_phylink_mac_config,
 118         .phylink_mac_link_down  = gswip_phylink_mac_link_down,
 119 @@ -1853,6 +1896,8 @@ static const struct dsa_switch_ops gswip
 120         .port_fdb_add           = gswip_port_fdb_add,
 121         .port_fdb_del           = gswip_port_fdb_del,
 122         .port_fdb_dump          = gswip_port_fdb_dump,
 123 +       .port_change_mtu        = gswip_port_change_mtu,
 124 +       .port_max_mtu           = gswip_port_max_mtu,
 125         .phylink_validate       = gswip_xrx300_phylink_validate,
 126         .phylink_mac_config     = gswip_phylink_mac_config,
 127         .phylink_mac_link_down  = gswip_phylink_mac_link_down,