net: dsa: sja1105: prepare tagger for handling DSA tags and VLAN simultaneously

In VLAN-unaware mode, sja1105 uses VLAN tags with a custom TPID of
0xdadb. While in the yet-to-be introduced best_effort_vlan_filtering
mode, it needs to work with normal VLAN TPID values.

A complication arises when we must transmit a VLAN-tagged packet to the
switch when it's in VLAN-aware mode. We need to construct a packet with
2 VLAN tags, and the switch will use the outer header for routing and
pop it on egress. But sadly, here the 2 hardware generations don't
behave the same:

- E/T switches won't pop an ETH_P_8021AD tag on egress, it seems
  (packets will remain double-tagged).
- P/Q/R/S switches will drop a packet with 2 ETH_P_8021Q tags (it looks
  like it tries to prevent VLAN hopping).

But looks like the reverse is also true:

- E/T switches have no problem popping the outer tag from packets with
  2 ETH_P_8021Q tags.
- P/Q/R/S will have no problem popping a single tag even if that is
  ETH_P_8021AD.

So it is clear that if we want the hardware to work with dsa_8021q
tagging in VLAN-aware mode, we need to send different TPIDs depending on
revision. Keep that information in priv->info->qinq_tpid.

The per-port tagger structure will hold an xmit_tpid value that depends
not only upon the qinq_tpid, but also upon the VLAN awareness state
itself (in case we must transmit using 0xdadb).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/sja1105/sja1105.h b/drivers/net/dsa/sja1105/sja1105.h
index c80f1999c6944f84bb78d0ae7d44c9b3cad71739..a019ffae38f1bbd729ad47771c584325fa33770c 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105.h
+++ b/drivers/net/dsa/sja1105/sja1105.h
@@ -87,6 +87,12 @@ struct sja1105_info {
        const struct sja1105_dynamic_table_ops *dyn_ops;
        const struct sja1105_table_ops *static_ops;
        const struct sja1105_regs *regs;
+       /* Both E/T and P/Q/R/S have quirks when it comes to popping the S-Tag
+        * from double-tagged frames. E/T will pop it only when it's equal to
+        * TPID from the General Parameters Table, while P/Q/R/S will only
+        * pop it when it's equal to TPID2.
+        */
+       u16 qinq_tpid;
        int (*reset_cmd)(struct dsa_switch *ds);
        int (*setup_rgmii_delay)(const void *ctx, int port);
        /* Prototypes from include/net/dsa.h */

diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 7b9c3db98e1d223c43af80296cdc46a4c03cffbb..b7e4a85caaded451a95e981533ef57beb2f03d92 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -2153,6 +2153,15 @@ static int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled)
                tpid2 = ETH_P_SJA1105;
        }
 
+       for (port = 0; port < ds->num_ports; port++) {
+               struct sja1105_port *sp = &priv->ports[port];
+
+               if (enabled)
+                       sp->xmit_tpid = priv->info->qinq_tpid;
+               else
+                       sp->xmit_tpid = ETH_P_SJA1105;
+       }
+
        if (!enabled)
                state = SJA1105_VLAN_UNAWARE;
        else
@@ -2866,6 +2875,7 @@ static int sja1105_probe(struct spi_device *spi)
                        goto out;
                }
                skb_queue_head_init(&sp->xmit_queue);
+               sp->xmit_tpid = ETH_P_SJA1105;
        }
 
        return 0;

diff --git a/drivers/net/dsa/sja1105/sja1105_spi.c b/drivers/net/dsa/sja1105/sja1105_spi.c
index 0be75c49e6c369f516220f842813c2c4232f97c4..a0dacae803cc10a0dacbf71a6f185931496f9def 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_spi.c
+++ b/drivers/net/dsa/sja1105/sja1105_spi.c
@@ -512,6 +512,7 @@ struct sja1105_info sja1105e_info = {
        .part_no                = SJA1105ET_PART_NO,
        .static_ops             = sja1105e_table_ops,
        .dyn_ops                = sja1105et_dyn_ops,
+       .qinq_tpid              = ETH_P_8021Q,
        .ptp_ts_bits            = 24,
        .ptpegr_ts_bytes        = 4,
        .reset_cmd              = sja1105et_reset_cmd,
@@ -526,6 +527,7 @@ struct sja1105_info sja1105t_info = {
        .part_no                = SJA1105ET_PART_NO,
        .static_ops             = sja1105t_table_ops,
        .dyn_ops                = sja1105et_dyn_ops,
+       .qinq_tpid              = ETH_P_8021Q,
        .ptp_ts_bits            = 24,
        .ptpegr_ts_bytes        = 4,
        .reset_cmd              = sja1105et_reset_cmd,
@@ -540,6 +542,7 @@ struct sja1105_info sja1105p_info = {
        .part_no                = SJA1105P_PART_NO,
        .static_ops             = sja1105p_table_ops,
        .dyn_ops                = sja1105pqrs_dyn_ops,
+       .qinq_tpid              = ETH_P_8021AD,
        .ptp_ts_bits            = 32,
        .ptpegr_ts_bytes        = 8,
        .setup_rgmii_delay      = sja1105pqrs_setup_rgmii_delay,
@@ -555,6 +558,7 @@ struct sja1105_info sja1105q_info = {
        .part_no                = SJA1105Q_PART_NO,
        .static_ops             = sja1105q_table_ops,
        .dyn_ops                = sja1105pqrs_dyn_ops,
+       .qinq_tpid              = ETH_P_8021AD,
        .ptp_ts_bits            = 32,
        .ptpegr_ts_bytes        = 8,
        .setup_rgmii_delay      = sja1105pqrs_setup_rgmii_delay,
@@ -570,6 +574,7 @@ struct sja1105_info sja1105r_info = {
        .part_no                = SJA1105R_PART_NO,
        .static_ops             = sja1105r_table_ops,
        .dyn_ops                = sja1105pqrs_dyn_ops,
+       .qinq_tpid              = ETH_P_8021AD,
        .ptp_ts_bits            = 32,
        .ptpegr_ts_bytes        = 8,
        .setup_rgmii_delay      = sja1105pqrs_setup_rgmii_delay,
@@ -586,6 +591,7 @@ struct sja1105_info sja1105s_info = {
        .static_ops             = sja1105s_table_ops,
        .dyn_ops                = sja1105pqrs_dyn_ops,
        .regs                   = &sja1105pqrs_regs,
+       .qinq_tpid              = ETH_P_8021AD,
        .ptp_ts_bits            = 32,
        .ptpegr_ts_bytes        = 8,
        .setup_rgmii_delay      = sja1105pqrs_setup_rgmii_delay,

diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index fa5735c353cdc4881b800d4b3b0ec07616f1a6d4..f821d08b1b5fefac523411503ac21fbd7b7dda89 100644 (file)
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -59,6 +59,7 @@ struct sja1105_port {
        struct sja1105_tagger_data *data;
        struct dsa_port *dp;
        bool hwts_tx_en;
+       u16 xmit_tpid;
 };
 
 #endif /* _NET_DSA_SJA1105_H */

diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index 5ecac5921a7d793984ed1dd6e8def451a55b6a30..398e2b9a1b965773a129b54b4263a1bc750ed3ef 100644 (file)
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -69,12 +69,25 @@ static inline bool sja1105_is_meta_frame(const struct sk_buff *skb)
        return true;
 }
 
+static bool sja1105_can_use_vlan_as_tags(const struct sk_buff *skb)
+{
+       struct vlan_ethhdr *hdr = vlan_eth_hdr(skb);
+
+       if (hdr->h_vlan_proto == ntohs(ETH_P_SJA1105))
+               return true;
+
+       if (hdr->h_vlan_proto != ntohs(ETH_P_8021Q))
+               return false;
+
+       return vid_is_dsa_8021q(ntohs(hdr->h_vlan_TCI) & VLAN_VID_MASK);
+}
+
 /* This is the first time the tagger sees the frame on RX.
  * Figure out if we can decode it.
  */
 static bool sja1105_filter(const struct sk_buff *skb, struct net_device *dev)
 {
-       if (!dsa_port_is_vlan_filtering(dev->dsa_ptr))
+       if (sja1105_can_use_vlan_as_tags(skb))
                return true;
        if (sja1105_is_link_local(skb))
                return true;
@@ -96,6 +109,11 @@ static struct sk_buff *sja1105_defer_xmit(struct sja1105_port *sp,
        return NULL;
 }
 
+static u16 sja1105_xmit_tpid(struct sja1105_port *sp)
+{
+       return sp->xmit_tpid;
+}
+
 static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
                                    struct net_device *netdev)
 {
@@ -111,15 +129,7 @@ static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
        if (unlikely(sja1105_is_link_local(skb)))
                return sja1105_defer_xmit(dp->priv, skb);
 
-       /* If we are under a vlan_filtering bridge, IP termination on
-        * switch ports based on 802.1Q tags is simply too brittle to
-        * be passable. So just defer to the dsa_slave_notag_xmit
-        * implementation.
-        */
-       if (dsa_port_is_vlan_filtering(dp))
-               return skb;
-
-       return dsa_8021q_xmit(skb, netdev, ETH_P_SJA1105,
+       return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp->priv),
                             ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
 }
 
@@ -258,7 +268,7 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
 
        hdr = eth_hdr(skb);
        tpid = ntohs(hdr->h_proto);
-       is_tagged = (tpid == ETH_P_SJA1105);
+       is_tagged = (tpid == ETH_P_SJA1105 || tpid == ETH_P_8021Q);
        is_link_local = sja1105_is_link_local(skb);
        is_meta = sja1105_is_meta_frame(skb);