target/linux/generic/backport-5.4/754-v5.7-net-dsa-mt7530-fix-roaming-from-DSA-user-ports.patch

   1 From 5e5502e012b8129e11be616acb0f9c34bc8f8adb Mon Sep 17 00:00:00 2001
   2 From: DENG Qingfang <dqfext@gmail.com>
   3 Date: Wed, 13 May 2020 23:10:16 +0800
   4 Subject: net: dsa: mt7530: fix roaming from DSA user ports
   5
   6 When a client moves from a DSA user port to a software port in a bridge,
   7 it cannot reach any other clients that connected to the DSA user ports.
   8 That is because SA learning on the CPU port is disabled, so the switch
   9 ignores the client's frames from the CPU port and still thinks it is at
  10 the user port.
  11
  12 Fix it by enabling SA learning on the CPU port.
  13
  14 To prevent the switch from learning from flooding frames from the CPU
  15 port, set skb->offload_fwd_mark to 1 for unicast and broadcast frames,
  16 and let the switch flood them instead of trapping to the CPU port.
  17 Multicast frames still need to be trapped to the CPU port for snooping,
  18 so set the SA_DIS bit of the MTK tag to 1 when transmitting those frames
  19 to disable SA learning.
  20
  21 Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
  22 Signed-off-by: DENG Qingfang <dqfext@gmail.com>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 ---
  25  drivers/net/dsa/mt7530.c |  9 ++-------
  26  drivers/net/dsa/mt7530.h |  1 +
  27  net/dsa/tag_mtk.c        | 15 +++++++++++++++
  28  3 files changed, 18 insertions(+), 7 deletions(-)
  29
  30 --- a/drivers/net/dsa/mt7530.c
  31 +++ b/drivers/net/dsa/mt7530.c
  32 @@ -639,11 +639,8 @@ mt7530_cpu_port_enable(struct mt7530_pri
  33         mt7530_write(priv, MT7530_PVC_P(port),
  34                      PORT_SPEC_TAG);
  35
  36 -       /* Disable auto learning on the cpu port */
  37 -       mt7530_set(priv, MT7530_PSC_P(port), SA_DIS);
  38 -
  39 -       /* Unknown unicast frame fordwarding to the cpu port */
  40 -       mt7530_set(priv, MT7530_MFC, UNU_FFP(BIT(port)));
  41 +       /* Unknown multicast frame forwarding to the cpu port */
  42 +       mt7530_rmw(priv, MT7530_MFC, UNM_FFP_MASK, UNM_FFP(BIT(port)));
  43
  44         /* Set CPU port number */
  45         if (priv->id == ID_MT7621)
  46 @@ -1298,8 +1295,6 @@ mt7530_setup(struct dsa_switch *ds)
  47         /* Enable and reset MIB counters */
  48         mt7530_mib_reset(ds);
  49
  50 -       mt7530_clear(priv, MT7530_MFC, UNU_FFP_MASK);
  51 -
  52         for (i = 0; i < MT7530_NUM_PORTS; i++) {
  53                 /* Disable forwarding by default on all ports */
  54                 mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
  55 --- a/drivers/net/dsa/mt7530.h
  56 +++ b/drivers/net/dsa/mt7530.h
  57 @@ -31,6 +31,7 @@ enum {
  58  #define MT7530_MFC                     0x10
  59  #define  BC_FFP(x)                     (((x) & 0xff) << 24)
  60  #define  UNM_FFP(x)                    (((x) & 0xff) << 16)
  61 +#define  UNM_FFP_MASK                  UNM_FFP(~0)
  62  #define  UNU_FFP(x)                    (((x) & 0xff) << 8)
  63  #define  UNU_FFP_MASK                  UNU_FFP(~0)
  64  #define  CPU_EN                                BIT(7)
  65 --- a/net/dsa/tag_mtk.c
  66 +++ b/net/dsa/tag_mtk.c
  67 @@ -15,6 +15,7 @@
  68  #define MTK_HDR_XMIT_TAGGED_TPID_8100  1
  69  #define MTK_HDR_RECV_SOURCE_PORT_MASK  GENMASK(2, 0)
  70  #define MTK_HDR_XMIT_DP_BIT_MASK       GENMASK(5, 0)
  71 +#define MTK_HDR_XMIT_SA_DIS            BIT(6)
  72
  73  static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
  74                                     struct net_device *dev)
  75 @@ -22,6 +23,9 @@ static struct sk_buff *mtk_tag_xmit(stru
  76         struct dsa_port *dp = dsa_slave_to_port(dev);
  77         u8 *mtk_tag;
  78         bool is_vlan_skb = true;
  79 +       unsigned char *dest = eth_hdr(skb)->h_dest;
  80 +       bool is_multicast_skb = is_multicast_ether_addr(dest) &&
  81 +                               !is_broadcast_ether_addr(dest);
  82
  83         /* Build the special tag after the MAC Source Address. If VLAN header
  84          * is present, it's required that VLAN header and special tag is
  85 @@ -47,6 +51,10 @@ static struct sk_buff *mtk_tag_xmit(stru
  86                      MTK_HDR_XMIT_UNTAGGED;
  87         mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK;
  88
  89 +       /* Disable SA learning for multicast frames */
  90 +       if (unlikely(is_multicast_skb))
  91 +               mtk_tag[1] |= MTK_HDR_XMIT_SA_DIS;
  92 +
  93         /* Tag control information is kept for 802.1Q */
  94         if (!is_vlan_skb) {
  95                 mtk_tag[2] = 0;
  96 @@ -61,6 +69,9 @@ static struct sk_buff *mtk_tag_rcv(struc
  97  {
  98         int port;
  99         __be16 *phdr, hdr;
 100 +       unsigned char *dest = eth_hdr(skb)->h_dest;
 101 +       bool is_multicast_skb = is_multicast_ether_addr(dest) &&
 102 +                               !is_broadcast_ether_addr(dest);
 103
 104         if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
 105                 return NULL;
 106 @@ -86,6 +97,10 @@ static struct sk_buff *mtk_tag_rcv(struc
 107         if (!skb->dev)
 108                 return NULL;
 109
 110 +       /* Only unicast or broadcast frames are offloaded */
 111 +       if (likely(!is_multicast_skb))
 112 +               skb->offload_fwd_mark = 1;
 113 +
 114         return skb;
 115  }
 116