Re: [PATCH net-next 2/8] net: dsa: tag_ksz: add tag handling for Microchip LAN937x
flat view
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2021-01-30 09:19:27
Also in:
linux-devicetree, lkml
On Thu, Jan 28, 2021 at 12:11:06PM +0530, Prasanna Vengateshan wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 4820dbcedfa2..6fac39c2b7d5 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c@@ -190,10 +190,84 @@ 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 Ingress (Host -> LAN937x), 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 Egress (LAN937x -> Host), 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) + */
You messed up the comment, right now it's as good as not having it. The one-hot port encoding is for xmit. The zero-based encoding is for rcv, not the other way around.
quoted hunk ↗ jump to hunk
+#define LAN937X_INGRESS_TAG_LEN 2 + +#define LAN937X_TAIL_TAG_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); + __be16 *tag; + u8 *addr; + u16 val; + + /* Tag encoding */
Do we really need this comment and the one with "Tag decoding" from rcv?
quoted hunk ↗ jump to hunk
+ tag = skb_put(skb, LAN937X_INGRESS_TAG_LEN); + addr = skb_mac_header(skb); + + val = BIT(dp->index); + + if (is_link_local_ether_addr(addr)) + val |= LAN937X_TAIL_TAG_OVERRIDE; + + /* Tail tag valid bit - This bit should always be set by the CPU*/ + val |= LAN937X_TAIL_TAG_VALID; + + *tag = cpu_to_be16(val); + + return skb; +} + +static struct sk_buff *lan937x_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt)
You can reuse ksz9477_rcv.
+{
+ /* Tag decoding */
+ u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+ unsigned int port = tag[0] & LAN937X_TAIL_TAG_PORT_MASK;
+ unsigned int len = KSZ_EGRESS_TAG_LEN;
+
+ /* Extra 4-bytes PTP timestamp */
+ if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
+ len += KSZ9477_PTP_TAG_LEN;
+
+ return ksz_common_rcv(skb, dev, port, len);
+}
+
+static const struct dsa_device_ops lan937x_netdev_ops = {
+ .name = "lan937x",
+ .proto = DSA_TAG_PROTO_LAN937X,
+ .xmit = lan937x_xmit,
+ .rcv = lan937x_rcv,
+ .overhead = LAN937X_INGRESS_TAG_LEN,
+ .tail_tag = true,
+};
+
+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);
--
2.25.1