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_xmit(struct sk_buff * skb,struct net_device * dev,int len)17 static struct sk_buff *ksz_common_xmit(struct sk_buff *skb,
18 struct net_device *dev, int len)
19 {
20 struct sk_buff *nskb;
21 int padlen;
22
23 padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len;
24
25 if (skb_tailroom(skb) >= padlen + len) {
26 /* Let dsa_slave_xmit() free skb */
27 if (__skb_put_padto(skb, skb->len + padlen, false))
28 return NULL;
29
30 nskb = skb;
31 } else {
32 nskb = alloc_skb(NET_IP_ALIGN + skb->len +
33 padlen + len, GFP_ATOMIC);
34 if (!nskb)
35 return NULL;
36 skb_reserve(nskb, NET_IP_ALIGN);
37
38 skb_reset_mac_header(nskb);
39 skb_set_network_header(nskb,
40 skb_network_header(skb) - skb->head);
41 skb_set_transport_header(nskb,
42 skb_transport_header(skb) - skb->head);
43 skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
44
45 /* Let skb_put_padto() free nskb, and let dsa_slave_xmit() free
46 * skb
47 */
48 if (skb_put_padto(nskb, nskb->len + padlen))
49 return NULL;
50
51 consume_skb(skb);
52 }
53
54 return nskb;
55 }
56
ksz_common_rcv(struct sk_buff * skb,struct net_device * dev,unsigned int port,unsigned int len)57 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
58 struct net_device *dev,
59 unsigned int port, unsigned int len)
60 {
61 skb->dev = dsa_master_find_slave(dev, 0, port);
62 if (!skb->dev)
63 return NULL;
64
65 pskb_trim_rcsum(skb, skb->len - len);
66
67 skb->offload_fwd_mark = true;
68
69 return skb;
70 }
71
72 /*
73 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
74 * ---------------------------------------------------------------------------
75 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
76 * ---------------------------------------------------------------------------
77 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
78 *
79 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
80 * ---------------------------------------------------------------------------
81 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
82 * ---------------------------------------------------------------------------
83 * tag0 : zero-based value represents port
84 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
85 */
86
87 #define KSZ8795_INGRESS_TAG_LEN 1
88
89 #define KSZ8795_TAIL_TAG_OVERRIDE BIT(6)
90 #define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
91
ksz8795_xmit(struct sk_buff * skb,struct net_device * dev)92 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
93 {
94 struct dsa_port *dp = dsa_slave_to_port(dev);
95 struct sk_buff *nskb;
96 u8 *tag;
97 u8 *addr;
98
99 nskb = ksz_common_xmit(skb, dev, KSZ8795_INGRESS_TAG_LEN);
100 if (!nskb)
101 return NULL;
102
103 /* Tag encoding */
104 tag = skb_put(nskb, KSZ8795_INGRESS_TAG_LEN);
105 addr = skb_mac_header(nskb);
106
107 *tag = 1 << dp->index;
108 if (is_link_local_ether_addr(addr))
109 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
110
111 return nskb;
112 }
113
ksz8795_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt)114 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev,
115 struct packet_type *pt)
116 {
117 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
118
119 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
120 }
121
122 static const struct dsa_device_ops ksz8795_netdev_ops = {
123 .name = "ksz8795",
124 .proto = DSA_TAG_PROTO_KSZ8795,
125 .xmit = ksz8795_xmit,
126 .rcv = ksz8795_rcv,
127 .overhead = KSZ8795_INGRESS_TAG_LEN,
128 };
129
130 DSA_TAG_DRIVER(ksz8795_netdev_ops);
131 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
132
133 /*
134 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
135 * ---------------------------------------------------------------------------
136 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
137 * ---------------------------------------------------------------------------
138 * tag0 : Prioritization (not used now)
139 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
140 *
141 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
142 * ---------------------------------------------------------------------------
143 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
144 * ---------------------------------------------------------------------------
145 * tag0 : zero-based value represents port
146 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
147 */
148
149 #define KSZ9477_INGRESS_TAG_LEN 2
150 #define KSZ9477_PTP_TAG_LEN 4
151 #define KSZ9477_PTP_TAG_INDICATION 0x80
152
153 #define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
154 #define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
155
ksz9477_xmit(struct sk_buff * skb,struct net_device * dev)156 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
157 struct net_device *dev)
158 {
159 struct dsa_port *dp = dsa_slave_to_port(dev);
160 struct sk_buff *nskb;
161 u16 *tag;
162 u8 *addr;
163
164 nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN);
165 if (!nskb)
166 return NULL;
167
168 /* Tag encoding */
169 tag = skb_put(nskb, KSZ9477_INGRESS_TAG_LEN);
170 addr = skb_mac_header(nskb);
171
172 *tag = BIT(dp->index);
173
174 if (is_link_local_ether_addr(addr))
175 *tag |= KSZ9477_TAIL_TAG_OVERRIDE;
176
177 *tag = cpu_to_be16(*tag);
178
179 return nskb;
180 }
181
ksz9477_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt)182 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev,
183 struct packet_type *pt)
184 {
185 /* Tag decoding */
186 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
187 unsigned int port = tag[0] & 7;
188 unsigned int len = KSZ_EGRESS_TAG_LEN;
189
190 /* Extra 4-bytes PTP timestamp */
191 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
192 len += KSZ9477_PTP_TAG_LEN;
193
194 return ksz_common_rcv(skb, dev, port, len);
195 }
196
197 static const struct dsa_device_ops ksz9477_netdev_ops = {
198 .name = "ksz9477",
199 .proto = DSA_TAG_PROTO_KSZ9477,
200 .xmit = ksz9477_xmit,
201 .rcv = ksz9477_rcv,
202 .overhead = KSZ9477_INGRESS_TAG_LEN,
203 };
204
205 DSA_TAG_DRIVER(ksz9477_netdev_ops);
206 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
207
208 #define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
209 #define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
210
ksz9893_xmit(struct sk_buff * skb,struct net_device * dev)211 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
212 struct net_device *dev)
213 {
214 struct dsa_port *dp = dsa_slave_to_port(dev);
215 struct sk_buff *nskb;
216 u8 *addr;
217 u8 *tag;
218
219 nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN);
220 if (!nskb)
221 return NULL;
222
223 /* Tag encoding */
224 tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN);
225 addr = skb_mac_header(nskb);
226
227 *tag = BIT(dp->index);
228
229 if (is_link_local_ether_addr(addr))
230 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
231
232 return nskb;
233 }
234
235 static const struct dsa_device_ops ksz9893_netdev_ops = {
236 .name = "ksz9893",
237 .proto = DSA_TAG_PROTO_KSZ9893,
238 .xmit = ksz9893_xmit,
239 .rcv = ksz9477_rcv,
240 .overhead = KSZ_INGRESS_TAG_LEN,
241 };
242
243 DSA_TAG_DRIVER(ksz9893_netdev_ops);
244 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
245
246 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
247 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
248 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
249 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
250 };
251
252 module_dsa_tag_drivers(dsa_tag_driver_array);
253
254 MODULE_LICENSE("GPL");
255