1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
4 * Copyright (c) 2017 Microchip Technology
5 */
6
7 #include <linux/etherdevice.h>
8 #include <linux/list.h>
9 #include <linux/slab.h>
10 #include <net/dsa.h>
11 #include "dsa_priv.h"
12
13 /* Typically only one byte is used for tail tag. */
14 #define KSZ_EGRESS_TAG_LEN 1
15 #define KSZ_INGRESS_TAG_LEN 1
16
ksz_common_rcv(struct sk_buff * skb,struct net_device * dev,unsigned int port,unsigned int len)17 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
18 struct net_device *dev,
19 unsigned int port, unsigned int len)
20 {
21 skb->dev = dsa_master_find_slave(dev, 0, port);
22 if (!skb->dev)
23 return NULL;
24
25 pskb_trim_rcsum(skb, skb->len - len);
26
27 skb->offload_fwd_mark = true;
28
29 return skb;
30 }
31
32 /*
33 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
34 * ---------------------------------------------------------------------------
35 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
36 * ---------------------------------------------------------------------------
37 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
38 *
39 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
40 * ---------------------------------------------------------------------------
41 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
42 * ---------------------------------------------------------------------------
43 * tag0 : zero-based value represents port
44 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
45 */
46
47 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
48 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
49
ksz8795_xmit(struct sk_buff * skb,struct net_device * dev)50 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
51 {
52 struct dsa_port *dp = dsa_slave_to_port(dev);
53 u8 *tag;
54 u8 *addr;
55
56 /* Tag encoding */
57 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
58 addr = skb_mac_header(skb);
59
60 *tag = 1 << dp->index;
61 if (is_link_local_ether_addr(addr))
62 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
63
64 return skb;
65 }
66
ksz8795_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt)67 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev,
68 struct packet_type *pt)
69 {
70 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
71
72 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
73 }
74
75 static const struct dsa_device_ops ksz8795_netdev_ops = {
76 .name = "ksz8795",
77 .proto = DSA_TAG_PROTO_KSZ8795,
78 .xmit = ksz8795_xmit,
79 .rcv = ksz8795_rcv,
80 .overhead = KSZ_INGRESS_TAG_LEN,
81 .tail_tag = true,
82 };
83
84 DSA_TAG_DRIVER(ksz8795_netdev_ops);
85 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
86
87 /*
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)
94 *
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)
101 */
102
103 #define KSZ9477_INGRESS_TAG_LEN 2
104 #define KSZ9477_PTP_TAG_LEN 4
105 #define KSZ9477_PTP_TAG_INDICATION 0x80
106
107 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
108 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
109
ksz9477_xmit(struct sk_buff * skb,struct net_device * dev)110 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
111 struct net_device *dev)
112 {
113 struct dsa_port *dp = dsa_slave_to_port(dev);
114 __be16 *tag;
115 u8 *addr;
116 u16 val;
117
118 /* Tag encoding */
119 tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
120 addr = skb_mac_header(skb);
121
122 val = BIT(dp->index);
123
124 if (is_link_local_ether_addr(addr))
125 val |= KSZ9477_TAIL_TAG_OVERRIDE;
126
127 *tag = cpu_to_be16(val);
128
129 return skb;
130 }
131
ksz9477_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt)132 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev,
133 struct packet_type *pt)
134 {
135 /* Tag decoding */
136 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
137 unsigned int port = tag[0] & 7;
138 unsigned int len = KSZ_EGRESS_TAG_LEN;
139
140 /* Extra 4-bytes PTP timestamp */
141 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
142 len += KSZ9477_PTP_TAG_LEN;
143
144 return ksz_common_rcv(skb, dev, port, len);
145 }
146
147 static const struct dsa_device_ops ksz9477_netdev_ops = {
148 .name = "ksz9477",
149 .proto = DSA_TAG_PROTO_KSZ9477,
150 .xmit = ksz9477_xmit,
151 .rcv = ksz9477_rcv,
152 .overhead = KSZ9477_INGRESS_TAG_LEN,
153 .tail_tag = true,
154 };
155
156 DSA_TAG_DRIVER(ksz9477_netdev_ops);
157 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
158
159 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
160 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
161
ksz9893_xmit(struct sk_buff * skb,struct net_device * dev)162 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
163 struct net_device *dev)
164 {
165 struct dsa_port *dp = dsa_slave_to_port(dev);
166 u8 *addr;
167 u8 *tag;
168
169 /* Tag encoding */
170 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
171 addr = skb_mac_header(skb);
172
173 *tag = BIT(dp->index);
174
175 if (is_link_local_ether_addr(addr))
176 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
177
178 return skb;
179 }
180
181 static const struct dsa_device_ops ksz9893_netdev_ops = {
182 .name = "ksz9893",
183 .proto = DSA_TAG_PROTO_KSZ9893,
184 .xmit = ksz9893_xmit,
185 .rcv = ksz9477_rcv,
186 .overhead = KSZ_INGRESS_TAG_LEN,
187 .tail_tag = true,
188 };
189
190 DSA_TAG_DRIVER(ksz9893_netdev_ops);
191 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
192
193 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
194 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
195 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
196 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
197 };
198
199 module_dsa_tag_drivers(dsa_tag_driver_array);
200
201 MODULE_LICENSE("GPL");
202