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1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 NXP Semiconductors
3 */
4#include <soc/mscc/ocelot.h>
5#include <linux/packing.h>
6#include "dsa_priv.h"
7
8/* The CPU injection header and the CPU extraction header can have 3 types of
9 * prefixes: long, short and no prefix. The format of the header itself is the
10 * same in all 3 cases.
11 *
12 * Extraction with long prefix:
13 *
14 * +-------------------+-------------------+------+------+------------+-------+
15 * | ff:ff:ff:ff:ff:ff | ff:ff:ff:ff:ff:ff | 8880 | 000a | extraction | frame |
16 * | | | | | header | |
17 * +-------------------+-------------------+------+------+------------+-------+
18 * 48 bits 48 bits 16 bits 16 bits 128 bits
19 *
20 * Extraction with short prefix:
21 *
22 * +------+------+------------+-------+
23 * | 8880 | 000a | extraction | frame |
24 * | | | header | |
25 * +------+------+------------+-------+
26 * 16 bits 16 bits 128 bits
27 *
28 * Extraction with no prefix:
29 *
30 * +------------+-------+
31 * | extraction | frame |
32 * | header | |
33 * +------------+-------+
34 * 128 bits
35 *
36 *
37 * Injection with long prefix:
38 *
39 * +-------------------+-------------------+------+------+------------+-------+
40 * | any dmac | any smac | 8880 | 000a | injection | frame |
41 * | | | | | header | |
42 * +-------------------+-------------------+------+------+------------+-------+
43 * 48 bits 48 bits 16 bits 16 bits 128 bits
44 *
45 * Injection with short prefix:
46 *
47 * +------+------+------------+-------+
48 * | 8880 | 000a | injection | frame |
49 * | | | header | |
50 * +------+------+------------+-------+
51 * 16 bits 16 bits 128 bits
52 *
53 * Injection with no prefix:
54 *
55 * +------------+-------+
56 * | injection | frame |
57 * | header | |
58 * +------------+-------+
59 * 128 bits
60 *
61 * The injection header looks like this (network byte order, bit 127
62 * is part of lowest address byte in memory, bit 0 is part of highest
63 * address byte):
64 *
65 * +------+------+------+------+------+------+------+------+
66 * 127:120 |BYPASS| MASQ | MASQ_PORT |REW_OP|REW_OP|
67 * +------+------+------+------+------+------+------+------+
68 * 119:112 | REW_OP |
69 * +------+------+------+------+------+------+------+------+
70 * 111:104 | REW_VAL |
71 * +------+------+------+------+------+------+------+------+
72 * 103: 96 | REW_VAL |
73 * +------+------+------+------+------+------+------+------+
74 * 95: 88 | REW_VAL |
75 * +------+------+------+------+------+------+------+------+
76 * 87: 80 | REW_VAL |
77 * +------+------+------+------+------+------+------+------+
78 * 79: 72 | RSV |
79 * +------+------+------+------+------+------+------+------+
80 * 71: 64 | RSV | DEST |
81 * +------+------+------+------+------+------+------+------+
82 * 63: 56 | DEST |
83 * +------+------+------+------+------+------+------+------+
84 * 55: 48 | RSV |
85 * +------+------+------+------+------+------+------+------+
86 * 47: 40 | RSV | SRC_PORT | RSV |TFRM_TIMER|
87 * +------+------+------+------+------+------+------+------+
88 * 39: 32 | TFRM_TIMER | RSV |
89 * +------+------+------+------+------+------+------+------+
90 * 31: 24 | RSV | DP | POP_CNT | CPUQ |
91 * +------+------+------+------+------+------+------+------+
92 * 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
93 * +------+------+------+------+------+------+------+------+
94 * 15: 8 | PCP | DEI | VID |
95 * +------+------+------+------+------+------+------+------+
96 * 7: 0 | VID |
97 * +------+------+------+------+------+------+------+------+
98 *
99 * And the extraction header looks like this:
100 *
101 * +------+------+------+------+------+------+------+------+
102 * 127:120 | RSV | REW_OP |
103 * +------+------+------+------+------+------+------+------+
104 * 119:112 | REW_OP | REW_VAL |
105 * +------+------+------+------+------+------+------+------+
106 * 111:104 | REW_VAL |
107 * +------+------+------+------+------+------+------+------+
108 * 103: 96 | REW_VAL |
109 * +------+------+------+------+------+------+------+------+
110 * 95: 88 | REW_VAL |
111 * +------+------+------+------+------+------+------+------+
112 * 87: 80 | REW_VAL | LLEN |
113 * +------+------+------+------+------+------+------+------+
114 * 79: 72 | LLEN | WLEN |
115 * +------+------+------+------+------+------+------+------+
116 * 71: 64 | WLEN | RSV |
117 * +------+------+------+------+------+------+------+------+
118 * 63: 56 | RSV |
119 * +------+------+------+------+------+------+------+------+
120 * 55: 48 | RSV |
121 * +------+------+------+------+------+------+------+------+
122 * 47: 40 | RSV | SRC_PORT | ACL_ID |
123 * +------+------+------+------+------+------+------+------+
124 * 39: 32 | ACL_ID | RSV | SFLOW_ID |
125 * +------+------+------+------+------+------+------+------+
126 * 31: 24 |ACL_HIT| DP | LRN_FLAGS | CPUQ |
127 * +------+------+------+------+------+------+------+------+
128 * 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
129 * +------+------+------+------+------+------+------+------+
130 * 15: 8 | PCP | DEI | VID |
131 * +------+------+------+------+------+------+------+------+
132 * 7: 0 | VID |
133 * +------+------+------+------+------+------+------+------+
134 */
135
136static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
137 struct net_device *netdev)
138{
139 struct dsa_port *dp = dsa_slave_to_port(netdev);
140 u64 bypass, dest, src, qos_class, rew_op;
141 struct dsa_switch *ds = dp->ds;
142 int port = dp->index;
143 struct ocelot *ocelot = ds->priv;
144 struct ocelot_port *ocelot_port = ocelot->ports[port];
145 u8 *injection;
146
147 if (unlikely(skb_cow_head(skb, OCELOT_TAG_LEN) < 0)) {
148 netdev_err(netdev, "Cannot make room for tag.\n");
149 return NULL;
150 }
151
152 injection = skb_push(skb, OCELOT_TAG_LEN);
153
154 memset(injection, 0, OCELOT_TAG_LEN);
155
156 /* Set the source port as the CPU port module and not the NPI port */
157 src = ocelot->num_phys_ports;
158 dest = BIT(port);
159 bypass = true;
160 qos_class = skb->priority;
161
162 packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0);
163 packing(injection, &dest, 68, 56, OCELOT_TAG_LEN, PACK, 0);
164 packing(injection, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0);
165 packing(injection, &qos_class, 19, 17, OCELOT_TAG_LEN, PACK, 0);
166
167 if (ocelot->ptp && (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
168 rew_op = ocelot_port->ptp_cmd;
169 if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
170 rew_op |= (ocelot_port->ts_id % 4) << 3;
171 ocelot_port->ts_id++;
172 }
173
174 packing(injection, &rew_op, 125, 117, OCELOT_TAG_LEN, PACK, 0);
175 }
176
177 return skb;
178}
179
180static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
181 struct net_device *netdev,
182 struct packet_type *pt)
183{
184 u64 src_port, qos_class;
185 u8 *start = skb->data;
186 u8 *extraction;
187
188 /* Revert skb->data by the amount consumed by the DSA master,
189 * so it points to the beginning of the frame.
190 */
191 skb_push(skb, ETH_HLEN);
192 /* We don't care about the long prefix, it is just for easy entrance
193 * into the DSA master's RX filter. Discard it now by moving it into
194 * the headroom.
195 */
196 skb_pull(skb, OCELOT_LONG_PREFIX_LEN);
197 /* And skb->data now points to the extraction frame header.
198 * Keep a pointer to it.
199 */
200 extraction = skb->data;
201 /* Now the EFH is part of the headroom as well */
202 skb_pull(skb, OCELOT_TAG_LEN);
203 /* Reset the pointer to the real MAC header */
204 skb_reset_mac_header(skb);
205 skb_reset_mac_len(skb);
206 /* And move skb->data to the correct location again */
207 skb_pull(skb, ETH_HLEN);
208
209 /* Remove from inet csum the extraction header */
210 skb_postpull_rcsum(skb, start, OCELOT_LONG_PREFIX_LEN + OCELOT_TAG_LEN);
211
212 packing(extraction, &src_port, 46, 43, OCELOT_TAG_LEN, UNPACK, 0);
213 packing(extraction, &qos_class, 19, 17, OCELOT_TAG_LEN, UNPACK, 0);
214
215 skb->dev = dsa_master_find_slave(netdev, 0, src_port);
216 if (!skb->dev)
217 /* The switch will reflect back some frames sent through
218 * sockets opened on the bare DSA master. These will come back
219 * with src_port equal to the index of the CPU port, for which
220 * there is no slave registered. So don't print any error
221 * message here (ignore and drop those frames).
222 */
223 return NULL;
224
225 skb->offload_fwd_mark = 1;
226 skb->priority = qos_class;
227
228 return skb;
229}
230
231static struct dsa_device_ops ocelot_netdev_ops = {
232 .name = "ocelot",
233 .proto = DSA_TAG_PROTO_OCELOT,
234 .xmit = ocelot_xmit,
235 .rcv = ocelot_rcv,
236 .overhead = OCELOT_TAG_LEN + OCELOT_LONG_PREFIX_LEN,
237};
238
239MODULE_LICENSE("GPL v2");
240MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT);
241
242module_dsa_tag_driver(ocelot_netdev_ops);