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>
9 #include <linux/slab.h>
13 /* Typically only one byte is used for tail tag. */
14 #define KSZ_EGRESS_TAG_LEN 1
15 #define KSZ_INGRESS_TAG_LEN 1
17 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
18 struct net_device *dev,
19 unsigned int port, unsigned int len)
21 skb->dev = dsa_master_find_slave(dev, 0, port);
25 if (pskb_trim_rcsum(skb, skb->len - len))
28 dsa_default_offload_fwd_mark(skb);
34 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
35 * ---------------------------------------------------------------------------
36 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
37 * ---------------------------------------------------------------------------
38 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
40 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
41 * ---------------------------------------------------------------------------
42 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
43 * ---------------------------------------------------------------------------
44 * tag0 : zero-based value represents port
45 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
48 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
49 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
51 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
53 struct dsa_port *dp = dsa_slave_to_port(dev);
57 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
61 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
62 addr = skb_mac_header(skb);
64 *tag = 1 << dp->index;
65 if (is_link_local_ether_addr(addr))
66 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
71 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
73 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
75 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
78 static const struct dsa_device_ops ksz8795_netdev_ops = {
80 .proto = DSA_TAG_PROTO_KSZ8795,
83 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
86 DSA_TAG_DRIVER(ksz8795_netdev_ops);
87 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
90 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
91 * ---------------------------------------------------------------------------
92 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
93 * ---------------------------------------------------------------------------
94 * tag0 : Prioritization (not used now)
95 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
97 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
98 * ---------------------------------------------------------------------------
99 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
100 * ---------------------------------------------------------------------------
101 * tag0 : zero-based value represents port
102 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
105 #define KSZ9477_INGRESS_TAG_LEN 2
106 #define KSZ9477_PTP_TAG_LEN 4
107 #define KSZ9477_PTP_TAG_INDICATION 0x80
109 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
110 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
112 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
113 struct net_device *dev)
115 struct dsa_port *dp = dsa_slave_to_port(dev);
120 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
124 tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
125 addr = skb_mac_header(skb);
127 val = BIT(dp->index);
129 if (is_link_local_ether_addr(addr))
130 val |= KSZ9477_TAIL_TAG_OVERRIDE;
132 *tag = cpu_to_be16(val);
137 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
140 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
141 unsigned int port = tag[0] & 7;
142 unsigned int len = KSZ_EGRESS_TAG_LEN;
144 /* Extra 4-bytes PTP timestamp */
145 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
146 len += KSZ9477_PTP_TAG_LEN;
148 return ksz_common_rcv(skb, dev, port, len);
151 static const struct dsa_device_ops ksz9477_netdev_ops = {
153 .proto = DSA_TAG_PROTO_KSZ9477,
154 .xmit = ksz9477_xmit,
156 .needed_tailroom = KSZ9477_INGRESS_TAG_LEN,
159 DSA_TAG_DRIVER(ksz9477_netdev_ops);
160 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
162 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
163 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
165 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
166 struct net_device *dev)
168 struct dsa_port *dp = dsa_slave_to_port(dev);
172 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
176 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
177 addr = skb_mac_header(skb);
179 *tag = BIT(dp->index);
181 if (is_link_local_ether_addr(addr))
182 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
187 static const struct dsa_device_ops ksz9893_netdev_ops = {
189 .proto = DSA_TAG_PROTO_KSZ9893,
190 .xmit = ksz9893_xmit,
192 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
195 DSA_TAG_DRIVER(ksz9893_netdev_ops);
196 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
198 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
199 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
200 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
201 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
204 module_dsa_tag_drivers(dsa_tag_driver_array);
206 MODULE_LICENSE("GPL");