From: DENG Qingfang <dqfext@gmail.com>
Date: Wed, 13 May 2020 23:10:16 +0800
Subject: net: dsa: mt7530: fix roaming from DSA user ports
Git-commit: 5e5502e012b8129e11be616acb0f9c34bc8f8adb
Patch-mainline: 5.7-rc7
References: networking-stable-20_05_27
When a client moves from a DSA user port to a software port in a bridge,
it cannot reach any other clients that connected to the DSA user ports.
That is because SA learning on the CPU port is disabled, so the switch
ignores the client's frames from the CPU port and still thinks it is at
the user port.
Fix it by enabling SA learning on the CPU port.
To prevent the switch from learning from flooding frames from the CPU
port, set skb->offload_fwd_mark to 1 for unicast and broadcast frames,
and let the switch flood them instead of trapping to the CPU port.
Multicast frames still need to be trapped to the CPU port for snooping,
so set the SA_DIS bit of the MTK tag to 1 when transmitting those frames
to disable SA learning.
Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/net/dsa/mt7530.c | 9 ++-------
drivers/net/dsa/mt7530.h | 1 +
net/dsa/tag_mtk.c | 16 ++++++++++++++++
3 files changed, 19 insertions(+), 7 deletions(-)
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -640,11 +640,8 @@ mt7530_cpu_port_enable(struct mt7530_pri
/* Setup the MAC by default for the cpu port */
mt7530_write(priv, MT7530_PMCR_P(port), PMCR_CPUP_LINK);
- /* Disable auto learning on the cpu port */
- mt7530_set(priv, MT7530_PSC_P(port), SA_DIS);
-
- /* Unknown unicast frame fordwarding to the cpu port */
- mt7530_set(priv, MT7530_MFC, UNU_FFP(BIT(port)));
+ /* Unknown multicast frame forwarding to the cpu port */
+ mt7530_rmw(priv, MT7530_MFC, UNM_FFP_MASK, UNM_FFP(BIT(port)));
/* CPU port gets connected to all user ports of
* the switch
@@ -981,8 +978,6 @@ mt7530_setup(struct dsa_switch *ds)
/* Enable and reset MIB counters */
mt7530_mib_reset(ds);
- mt7530_clear(priv, MT7530_MFC, UNU_FFP_MASK);
-
for (i = 0; i < MT7530_NUM_PORTS; i++) {
/* Disable forwarding by default on all ports */
mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -33,6 +33,7 @@
#define MT7530_MFC 0x10
#define BC_FFP(x) (((x) & 0xff) << 24)
#define UNM_FFP(x) (((x) & 0xff) << 16)
+#define UNM_FFP_MASK UNM_FFP(~0)
#define UNU_FFP(x) (((x) & 0xff) << 8)
#define UNU_FFP_MASK UNU_FFP(~0)
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c
@@ -19,12 +19,16 @@
#define MTK_HDR_LEN 4
#define MTK_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
#define MTK_HDR_XMIT_DP_BIT_MASK GENMASK(5, 0)
+#define MTK_HDR_XMIT_SA_DIS BIT(6)
static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct dsa_slave_priv *p = netdev_priv(dev);
u8 *mtk_tag;
+ unsigned char *dest = eth_hdr(skb)->h_dest;
+ bool is_multicast_skb = is_multicast_ether_addr(dest) &&
+ !is_broadcast_ether_addr(dest);
if (skb_cow_head(skb, MTK_HDR_LEN) < 0)
goto out_free;
@@ -37,6 +41,11 @@ static struct sk_buff *mtk_tag_xmit(stru
mtk_tag = skb->data + 2 * ETH_ALEN;
mtk_tag[0] = 0;
mtk_tag[1] = (1 << p->dp->index) & MTK_HDR_XMIT_DP_BIT_MASK;
+
+ /* Disable SA learning for multicast frames */
+ if (unlikely(is_multicast_skb))
+ mtk_tag[1] |= MTK_HDR_XMIT_SA_DIS;
+
mtk_tag[2] = 0;
mtk_tag[3] = 0;
@@ -55,6 +64,9 @@ static struct sk_buff *mtk_tag_rcv(struc
struct dsa_switch *ds;
int port;
__be16 *phdr, hdr;
+ unsigned char *dest = eth_hdr(skb)->h_dest;
+ bool is_multicast_skb = is_multicast_ether_addr(dest) &&
+ !is_broadcast_ether_addr(dest);
if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
goto out_drop;
@@ -88,6 +100,10 @@ static struct sk_buff *mtk_tag_rcv(struc
skb->dev = ds->ports[port].netdev;
+ /* Only unicast or broadcast frames are offloaded */
+ if (likely(!is_multicast_skb))
+ skb->offload_fwd_mark = 1;
+
return skb;
out_drop: