1 // SPDX-License-Identifier: GPL-2.0+
3 * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
4 * Copyright (c) 2017 Microchip Technology
7 #include <linux/etherdevice.h>
8 #include <linux/list.h>
12 /* Typically only one byte is used for tail tag. */
13 #define KSZ_EGRESS_TAG_LEN 1
14 #define KSZ_INGRESS_TAG_LEN 1
16 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
17 struct net_device *dev,
18 unsigned int port, unsigned int len)
20 skb->dev = dsa_master_find_slave(dev, 0, port);
24 pskb_trim_rcsum(skb, skb->len - len);
26 dsa_default_offload_fwd_mark(skb);
32 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
33 * ---------------------------------------------------------------------------
34 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
35 * ---------------------------------------------------------------------------
36 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
38 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
39 * ---------------------------------------------------------------------------
40 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
41 * ---------------------------------------------------------------------------
42 * tag0 : zero-based value represents port
43 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
46 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
47 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
49 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
51 struct dsa_port *dp = dsa_slave_to_port(dev);
55 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
59 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
60 addr = skb_mac_header(skb);
62 *tag = 1 << dp->index;
63 if (is_link_local_ether_addr(addr))
64 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
69 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
71 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
73 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
76 static const struct dsa_device_ops ksz8795_netdev_ops = {
78 .proto = DSA_TAG_PROTO_KSZ8795,
81 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
84 DSA_TAG_DRIVER(ksz8795_netdev_ops);
85 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
88 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
89 * ---------------------------------------------------------------------------
90 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
91 * ---------------------------------------------------------------------------
92 * tag0 : Prioritization (not used now)
93 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
95 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
96 * ---------------------------------------------------------------------------
97 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
98 * ---------------------------------------------------------------------------
99 * tag0 : zero-based value represents port
100 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
103 #define KSZ9477_INGRESS_TAG_LEN 2
104 #define KSZ9477_PTP_TAG_LEN 4
105 #define KSZ9477_PTP_TAG_INDICATION 0x80
107 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
108 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
110 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
111 struct net_device *dev)
113 struct dsa_port *dp = dsa_slave_to_port(dev);
118 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
122 tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
123 addr = skb_mac_header(skb);
125 val = BIT(dp->index);
127 if (is_link_local_ether_addr(addr))
128 val |= KSZ9477_TAIL_TAG_OVERRIDE;
130 *tag = cpu_to_be16(val);
135 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
138 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
139 unsigned int port = tag[0] & 7;
140 unsigned int len = KSZ_EGRESS_TAG_LEN;
142 /* Extra 4-bytes PTP timestamp */
143 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
144 len += KSZ9477_PTP_TAG_LEN;
146 return ksz_common_rcv(skb, dev, port, len);
149 static const struct dsa_device_ops ksz9477_netdev_ops = {
151 .proto = DSA_TAG_PROTO_KSZ9477,
152 .xmit = ksz9477_xmit,
154 .needed_tailroom = KSZ9477_INGRESS_TAG_LEN,
157 DSA_TAG_DRIVER(ksz9477_netdev_ops);
158 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
160 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
161 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
163 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
164 struct net_device *dev)
166 struct dsa_port *dp = dsa_slave_to_port(dev);
170 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
174 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
175 addr = skb_mac_header(skb);
177 *tag = BIT(dp->index);
179 if (is_link_local_ether_addr(addr))
180 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
185 static const struct dsa_device_ops ksz9893_netdev_ops = {
187 .proto = DSA_TAG_PROTO_KSZ9893,
188 .xmit = ksz9893_xmit,
190 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
193 DSA_TAG_DRIVER(ksz9893_netdev_ops);
194 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
196 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
197 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
198 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
199 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
202 module_dsa_tag_drivers(dsa_tag_driver_array);
204 MODULE_LICENSE("GPL");