tjh.dev
Linux kernel mirror (for testing)
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linux
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
17static 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
57static 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_TAIL_TAG_OVERRIDE BIT(6)
88#define KSZ8795_TAIL_TAG_LOOKUP BIT(7)
89
90static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
91{
92 struct dsa_port *dp = dsa_slave_to_port(dev);
93 struct sk_buff *nskb;
94 u8 *tag;
95 u8 *addr;
96
97 nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN);
98 if (!nskb)
99 return NULL;
100
101 /* Tag encoding */
102 tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN);
103 addr = skb_mac_header(nskb);
104
105 *tag = 1 << dp->index;
106 if (is_link_local_ether_addr(addr))
107 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
108
109 return nskb;
110}
111
112static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev,
113 struct packet_type *pt)
114{
115 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
116
117 return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
118}
119
120static const struct dsa_device_ops ksz8795_netdev_ops = {
121 .name = "ksz8795",
122 .proto = DSA_TAG_PROTO_KSZ8795,
123 .xmit = ksz8795_xmit,
124 .rcv = ksz8795_rcv,
125 .overhead = KSZ_INGRESS_TAG_LEN,
126};
127
128DSA_TAG_DRIVER(ksz8795_netdev_ops);
129MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
130
131/*
132 * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
133 * ---------------------------------------------------------------------------
134 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
135 * ---------------------------------------------------------------------------
136 * tag0 : Prioritization (not used now)
137 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
138 *
139 * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
140 * ---------------------------------------------------------------------------
141 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
142 * ---------------------------------------------------------------------------
143 * tag0 : zero-based value represents port
144 * (eg, 0x00=port1, 0x02=port3, 0x06=port7)
145 */
146
147#define KSZ9477_INGRESS_TAG_LEN 2
148#define KSZ9477_PTP_TAG_LEN 4
149#define KSZ9477_PTP_TAG_INDICATION 0x80
150
151#define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
152#define KSZ9477_TAIL_TAG_LOOKUP BIT(10)
153
154static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
155 struct net_device *dev)
156{
157 struct dsa_port *dp = dsa_slave_to_port(dev);
158 struct sk_buff *nskb;
159 u16 *tag;
160 u8 *addr;
161
162 nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN);
163 if (!nskb)
164 return NULL;
165
166 /* Tag encoding */
167 tag = skb_put(nskb, KSZ9477_INGRESS_TAG_LEN);
168 addr = skb_mac_header(nskb);
169
170 *tag = BIT(dp->index);
171
172 if (is_link_local_ether_addr(addr))
173 *tag |= KSZ9477_TAIL_TAG_OVERRIDE;
174
175 *tag = cpu_to_be16(*tag);
176
177 return nskb;
178}
179
180static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev,
181 struct packet_type *pt)
182{
183 /* Tag decoding */
184 u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
185 unsigned int port = tag[0] & 7;
186 unsigned int len = KSZ_EGRESS_TAG_LEN;
187
188 /* Extra 4-bytes PTP timestamp */
189 if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
190 len += KSZ9477_PTP_TAG_LEN;
191
192 return ksz_common_rcv(skb, dev, port, len);
193}
194
195static const struct dsa_device_ops ksz9477_netdev_ops = {
196 .name = "ksz9477",
197 .proto = DSA_TAG_PROTO_KSZ9477,
198 .xmit = ksz9477_xmit,
199 .rcv = ksz9477_rcv,
200 .overhead = KSZ9477_INGRESS_TAG_LEN,
201};
202
203DSA_TAG_DRIVER(ksz9477_netdev_ops);
204MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477);
205
206#define KSZ9893_TAIL_TAG_OVERRIDE BIT(5)
207#define KSZ9893_TAIL_TAG_LOOKUP BIT(6)
208
209static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
210 struct net_device *dev)
211{
212 struct dsa_port *dp = dsa_slave_to_port(dev);
213 struct sk_buff *nskb;
214 u8 *addr;
215 u8 *tag;
216
217 nskb = ksz_common_xmit(skb, dev, KSZ_INGRESS_TAG_LEN);
218 if (!nskb)
219 return NULL;
220
221 /* Tag encoding */
222 tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN);
223 addr = skb_mac_header(nskb);
224
225 *tag = BIT(dp->index);
226
227 if (is_link_local_ether_addr(addr))
228 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
229
230 return nskb;
231}
232
233static const struct dsa_device_ops ksz9893_netdev_ops = {
234 .name = "ksz9893",
235 .proto = DSA_TAG_PROTO_KSZ9893,
236 .xmit = ksz9893_xmit,
237 .rcv = ksz9477_rcv,
238 .overhead = KSZ_INGRESS_TAG_LEN,
239};
240
241DSA_TAG_DRIVER(ksz9893_netdev_ops);
242MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893);
243
244static struct dsa_tag_driver *dsa_tag_driver_array[] = {
245 &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
246 &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
247 &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
248};
249
250module_dsa_tag_drivers(dsa_tag_driver_array);
251
252MODULE_LICENSE("GPL");