net: dsa: tag_ksz: add tag handling for Microchip LAN937x

The Microchip LAN937X switches have a tagging protocol which is
very similar to KSZ tagging. So that the implementation is added to
tag_ksz.c and reused common APIs

Signed-off-by: Prasanna Vengateshan <prasanna.vengateshan@microchip.com>
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/dsa.h b/include/net/dsa.h
index ea7bf00..b902b31 100644 (file)
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -54,6 +54,7 @@ struct phylink_link_state;
 #define DSA_TAG_PROTO_RTL8_4_VALUE             24
 #define DSA_TAG_PROTO_RTL8_4T_VALUE            25
 #define DSA_TAG_PROTO_RZN1_A5PSW_VALUE         26
+#define DSA_TAG_PROTO_LAN937X_VALUE            27
 
 enum dsa_tag_protocol {
        DSA_TAG_PROTO_NONE              = DSA_TAG_PROTO_NONE_VALUE,
@@ -83,6 +84,7 @@ enum dsa_tag_protocol {
        DSA_TAG_PROTO_RTL8_4            = DSA_TAG_PROTO_RTL8_4_VALUE,
        DSA_TAG_PROTO_RTL8_4T           = DSA_TAG_PROTO_RTL8_4T_VALUE,
        DSA_TAG_PROTO_RZN1_A5PSW        = DSA_TAG_PROTO_RZN1_A5PSW_VALUE,
+       DSA_TAG_PROTO_LAN937X           = DSA_TAG_PROTO_LAN937X_VALUE,
 };
 
 struct dsa_switch;

diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 63853ff..3eef72c 100644 (file)
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -87,10 +87,10 @@ config NET_DSA_TAG_MTK
          Mediatek switches.
 
 config NET_DSA_TAG_KSZ
-       tristate "Tag driver for Microchip 8795/9477/9893 families of switches"
+       tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
        help
          Say Y if you want to enable support for tagging frames for the
-         Microchip 8795/9477/9893 families of switches.
+         Microchip 8795/937x/9477/9893 families of switches.
 
 config NET_DSA_TAG_OCELOT
        tristate "Tag driver for Ocelot family of switches, using NPI port"

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 3509fc9..38fa19c 100644 (file)
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -193,10 +193,69 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
 DSA_TAG_DRIVER(ksz9893_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
 
+/* For xmit, 2 bytes are added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag0 : represents tag override, lookup and valid
+ * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
+ *
+ * For rcv, 1 byte is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag0 : zero-based value represents port
+ *       (eg, 0x00=port1, 0x02=port3, 0x07=port8)
+ */
+#define LAN937X_EGRESS_TAG_LEN         2
+
+#define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE     BIT(11)
+#define LAN937X_TAIL_TAG_LOOKUP                        BIT(12)
+#define LAN937X_TAIL_TAG_VALID                 BIT(13)
+#define LAN937X_TAIL_TAG_PORT_MASK             7
+
+static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
+                                   struct net_device *dev)
+{
+       struct dsa_port *dp = dsa_slave_to_port(dev);
+       const struct ethhdr *hdr = eth_hdr(skb);
+       __be16 *tag;
+       u16 val;
+
+       if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
+               return NULL;
+
+       tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
+
+       val = BIT(dp->index);
+
+       if (is_link_local_ether_addr(hdr->h_dest))
+               val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
+
+       /* Tail tag valid bit - This bit should always be set by the CPU */
+       val |= LAN937X_TAIL_TAG_VALID;
+
+       put_unaligned_be16(val, tag);
+
+       return skb;
+}
+
+static const struct dsa_device_ops lan937x_netdev_ops = {
+       .name   = "lan937x",
+       .proto  = DSA_TAG_PROTO_LAN937X,
+       .xmit   = lan937x_xmit,
+       .rcv    = ksz9477_rcv,
+       .needed_tailroom = LAN937X_EGRESS_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(lan937x_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X);
+
 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
        &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
        &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
        &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
+       &DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
 };
 
 module_dsa_tag_drivers(dsa_tag_driver_array);