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 if (pskb_trim_rcsum(skb, skb->len - len))
26 return NULL;
27
28 dsa_default_offload_fwd_mark(skb);
29
30 return skb;
31 }
32
33 /*
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)
39 *
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)
46 */
47
48 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
49 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
50
ksz8795_xmit(struct sk_buff * skb,struct net_device * dev)51 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
52 {
53 struct dsa_port *dp = dsa_slave_to_port(dev);
54 u8 *tag;
55 u8 *addr;
56
57 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
58 return NULL;
59
60 /* Tag encoding */
61 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
62 addr = skb_mac_header(skb);
63
64 *tag = 1 << dp->index;
65 if (is_link_local_ether_addr(addr))
66 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
67
68 return skb;
69 }
70
ksz8795_rcv(struct sk_buff * skb,struct net_device * dev)71 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
72 {
73 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
74
75 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
76 }
77
78 static const struct dsa_device_ops ksz8795_netdev_ops = {
79 .name = "ksz8795",
80 .proto = DSA_TAG_PROTO_KSZ8795,
81 .xmit = ksz8795_xmit,
82 .rcv = ksz8795_rcv,
83 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
84 };
85
86 DSA_TAG_DRIVER(ksz8795_netdev_ops);
87 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
88
89 /*
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)
96 *
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)
103 */
104
105 #define KSZ9477_INGRESS_TAG_LEN 2
106 #define KSZ9477_PTP_TAG_LEN 4
107 #define KSZ9477_PTP_TAG_INDICATION 0x80
108
109 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
110 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
111
ksz9477_xmit(struct sk_buff * skb,struct net_device * dev)112 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
113 struct net_device *dev)
114 {
115 struct dsa_port *dp = dsa_slave_to_port(dev);
116 __be16 *tag;
117 u8 *addr;
118 u16 val;
119
120 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
121 return NULL;
122
123 /* Tag encoding */
124 tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
125 addr = skb_mac_header(skb);
126
127 val = BIT(dp->index);
128
129 if (is_link_local_ether_addr(addr))
130 val |= KSZ9477_TAIL_TAG_OVERRIDE;
131
132 *tag = cpu_to_be16(val);
133
134 return skb;
135 }
136
ksz9477_rcv(struct sk_buff * skb,struct net_device * dev)137 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
138 {
139 /* Tag decoding */
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;
143
144 /* Extra 4-bytes PTP timestamp */
145 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
146 len += KSZ9477_PTP_TAG_LEN;
147
148 return ksz_common_rcv(skb, dev, port, len);
149 }
150
151 static const struct dsa_device_ops ksz9477_netdev_ops = {
152 .name = "ksz9477",
153 .proto = DSA_TAG_PROTO_KSZ9477,
154 .xmit = ksz9477_xmit,
155 .rcv = ksz9477_rcv,
156 .needed_tailroom = KSZ9477_INGRESS_TAG_LEN,
157 };
158
159 DSA_TAG_DRIVER(ksz9477_netdev_ops);
160 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
161
162 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
163 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
164
ksz9893_xmit(struct sk_buff * skb,struct net_device * dev)165 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
166 struct net_device *dev)
167 {
168 struct dsa_port *dp = dsa_slave_to_port(dev);
169 u8 *addr;
170 u8 *tag;
171
172 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
173 return NULL;
174
175 /* Tag encoding */
176 tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
177 addr = skb_mac_header(skb);
178
179 *tag = BIT(dp->index);
180
181 if (is_link_local_ether_addr(addr))
182 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
183
184 return skb;
185 }
186
187 static const struct dsa_device_ops ksz9893_netdev_ops = {
188 .name = "ksz9893",
189 .proto = DSA_TAG_PROTO_KSZ9893,
190 .xmit = ksz9893_xmit,
191 .rcv = ksz9477_rcv,
192 .needed_tailroom = KSZ_INGRESS_TAG_LEN,
193 };
194
195 DSA_TAG_DRIVER(ksz9893_netdev_ops);
196 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
197
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),
202 };
203
204 module_dsa_tag_drivers(dsa_tag_driver_array);
205
206 MODULE_LICENSE("GPL");
207