1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 NXP
3 */
4#include <linux/dsa/ocelot.h>
5
6#include "tag.h"
7
8#define OCELOT_NAME "ocelot"
9#define SEVILLE_NAME "seville"
10
11/* If the port is under a VLAN-aware bridge, remove the VLAN header from the
12 * payload and move it into the DSA tag, which will make the switch classify
13 * the packet to the bridge VLAN. Otherwise, leave the classified VLAN at zero,
14 * which is the pvid of standalone and VLAN-unaware bridge ports.
15 */
16static void ocelot_xmit_get_vlan_info(struct sk_buff *skb, struct dsa_port *dp,
17 u64 *vlan_tci, u64 *tag_type)
18{
19 struct net_device *br = dsa_port_bridge_dev_get(dp);
20 struct vlan_ethhdr *hdr;
21 u16 proto, tci;
22
23 if (!br || !br_vlan_enabled(dev: br)) {
24 *vlan_tci = 0;
25 *tag_type = IFH_TAG_TYPE_C;
26 return;
27 }
28
29 hdr = skb_vlan_eth_hdr(skb);
30 br_vlan_get_proto(dev: br, p_proto: &proto);
31
32 if (ntohs(hdr->h_vlan_proto) == proto) {
33 vlan_remove_tag(skb, vlan_tci: &tci);
34 *vlan_tci = tci;
35 } else {
36 rcu_read_lock();
37 br_vlan_get_pvid_rcu(dev: br, p_pvid: &tci);
38 rcu_read_unlock();
39 *vlan_tci = tci;
40 }
41
42 *tag_type = (proto != ETH_P_8021Q) ? IFH_TAG_TYPE_S : IFH_TAG_TYPE_C;
43}
44
45static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
46 __be32 ifh_prefix, void **ifh)
47{
48 struct dsa_port *dp = dsa_user_to_port(dev: netdev);
49 struct dsa_switch *ds = dp->ds;
50 u64 vlan_tci, tag_type;
51 void *injection;
52 __be32 *prefix;
53 u32 rew_op = 0;
54 u64 qos_class;
55
56 ocelot_xmit_get_vlan_info(skb, dp, vlan_tci: &vlan_tci, tag_type: &tag_type);
57
58 qos_class = netdev_get_num_tc(dev: netdev) ?
59 netdev_get_prio_tc_map(dev: netdev, prio: skb->priority) : skb->priority;
60
61 injection = skb_push(skb, OCELOT_TAG_LEN);
62 prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
63
64 *prefix = ifh_prefix;
65 memset(injection, 0, OCELOT_TAG_LEN);
66 ocelot_ifh_set_bypass(injection, bypass: 1);
67 ocelot_ifh_set_src(injection, src: ds->num_ports);
68 ocelot_ifh_set_qos_class(injection, qos_class);
69 ocelot_ifh_set_vlan_tci(injection, vlan_tci);
70 ocelot_ifh_set_tag_type(injection, tag_type);
71
72 rew_op = ocelot_ptp_rew_op(skb);
73 if (rew_op)
74 ocelot_ifh_set_rew_op(injection, rew_op);
75
76 *ifh = injection;
77}
78
79static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
80 struct net_device *netdev)
81{
82 struct dsa_port *dp = dsa_user_to_port(dev: netdev);
83 void *injection;
84
85 ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), ifh: &injection);
86 ocelot_ifh_set_dest(injection, BIT_ULL(dp->index));
87
88 return skb;
89}
90
91static struct sk_buff *seville_xmit(struct sk_buff *skb,
92 struct net_device *netdev)
93{
94 struct dsa_port *dp = dsa_user_to_port(dev: netdev);
95 void *injection;
96
97 ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), ifh: &injection);
98 seville_ifh_set_dest(injection, BIT_ULL(dp->index));
99
100 return skb;
101}
102
103static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
104 struct net_device *netdev)
105{
106 u64 src_port, qos_class;
107 u64 vlan_tci, tag_type;
108 u8 *start = skb->data;
109 struct dsa_port *dp;
110 u8 *extraction;
111 u16 vlan_tpid;
112 u64 rew_val;
113
114 /* Revert skb->data by the amount consumed by the DSA conduit,
115 * so it points to the beginning of the frame.
116 */
117 skb_push(skb, ETH_HLEN);
118 /* We don't care about the short prefix, it is just for easy entrance
119 * into the DSA conduit's RX filter. Discard it now by moving it into
120 * the headroom.
121 */
122 skb_pull(skb, OCELOT_SHORT_PREFIX_LEN);
123 /* And skb->data now points to the extraction frame header.
124 * Keep a pointer to it.
125 */
126 extraction = skb->data;
127 /* Now the EFH is part of the headroom as well */
128 skb_pull(skb, OCELOT_TAG_LEN);
129 /* Reset the pointer to the real MAC header */
130 skb_reset_mac_header(skb);
131 skb_reset_mac_len(skb);
132 /* And move skb->data to the correct location again */
133 skb_pull(skb, ETH_HLEN);
134
135 /* Remove from inet csum the extraction header */
136 skb_postpull_rcsum(skb, start, OCELOT_TOTAL_TAG_LEN);
137
138 ocelot_xfh_get_src_port(extraction, src_port: &src_port);
139 ocelot_xfh_get_qos_class(extraction, qos_class: &qos_class);
140 ocelot_xfh_get_tag_type(extraction, tag_type: &tag_type);
141 ocelot_xfh_get_vlan_tci(extraction, vlan_tci: &vlan_tci);
142 ocelot_xfh_get_rew_val(extraction, rew_val: &rew_val);
143
144 skb->dev = dsa_conduit_find_user(dev: netdev, device: 0, port: src_port);
145 if (!skb->dev)
146 /* The switch will reflect back some frames sent through
147 * sockets opened on the bare DSA conduit. These will come back
148 * with src_port equal to the index of the CPU port, for which
149 * there is no user registered. So don't print any error
150 * message here (ignore and drop those frames).
151 */
152 return NULL;
153
154 dsa_default_offload_fwd_mark(skb);
155 skb->priority = qos_class;
156 OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;
157
158 /* Ocelot switches copy frames unmodified to the CPU. However, it is
159 * possible for the user to request a VLAN modification through
160 * VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
161 * the VLAN ID field from the Extraction Header gets updated, but the
162 * 802.1Q header does not (the classified VLAN only becomes visible on
163 * egress through the "port tag" of front-panel ports).
164 * So, for traffic extracted by the CPU, we want to pick up the
165 * classified VLAN and manually replace the existing 802.1Q header from
166 * the packet with it, so that the operating system is always up to
167 * date with the result of tc-vlan actions.
168 * NOTE: In VLAN-unaware mode, we don't want to do that, we want the
169 * frame to remain unmodified, because the classified VLAN is always
170 * equal to the pvid of the ingress port and should not be used for
171 * processing.
172 */
173 dp = dsa_user_to_port(dev: skb->dev);
174 vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
175
176 if (dsa_port_is_vlan_filtering(dp) &&
177 eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
178 u16 dummy_vlan_tci;
179
180 skb_push_rcsum(skb, ETH_HLEN);
181 __skb_vlan_pop(skb, vlan_tci: &dummy_vlan_tci);
182 skb_pull_rcsum(skb, ETH_HLEN);
183 __vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
184 }
185
186 return skb;
187}
188
189static const struct dsa_device_ops ocelot_netdev_ops = {
190 .name = OCELOT_NAME,
191 .proto = DSA_TAG_PROTO_OCELOT,
192 .xmit = ocelot_xmit,
193 .rcv = ocelot_rcv,
194 .needed_headroom = OCELOT_TOTAL_TAG_LEN,
195 .promisc_on_conduit = true,
196};
197
198DSA_TAG_DRIVER(ocelot_netdev_ops);
199MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT, OCELOT_NAME);
200
201static const struct dsa_device_ops seville_netdev_ops = {
202 .name = SEVILLE_NAME,
203 .proto = DSA_TAG_PROTO_SEVILLE,
204 .xmit = seville_xmit,
205 .rcv = ocelot_rcv,
206 .needed_headroom = OCELOT_TOTAL_TAG_LEN,
207 .promisc_on_conduit = true,
208};
209
210DSA_TAG_DRIVER(seville_netdev_ops);
211MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE, SEVILLE_NAME);
212
213static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
214 &DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
215 &DSA_TAG_DRIVER_NAME(seville_netdev_ops),
216};
217
218module_dsa_tag_drivers(ocelot_tag_driver_array);
219
220MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using NPI port");
221MODULE_LICENSE("GPL v2");
222

source code of linux/net/dsa/tag_ocelot.c