1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2020-2021 NXP
3 *
4 * An implementation of the software-defined tag_8021q.c tagger format, which
5 * also preserves full functionality under a vlan_filtering bridge. It does
6 * this by using the TCAM engines for:
7 * - pushing the RX VLAN as a second, outer tag, on egress towards the CPU port
8 * - redirecting towards the correct front port based on TX VLAN and popping
9 * that on egress
10 */
11 #include <linux/dsa/8021q.h>
12 #include <linux/dsa/ocelot.h>
13
14 #include "tag.h"
15 #include "tag_8021q.h"
16
17 #define OCELOT_8021Q_NAME "ocelot-8021q"
18
19 struct ocelot_8021q_tagger_private {
20 struct ocelot_8021q_tagger_data data; /* Must be first */
21 struct kthread_worker *xmit_worker;
22 };
23
ocelot_defer_xmit(struct dsa_port * dp,struct sk_buff * skb)24 static struct sk_buff *ocelot_defer_xmit(struct dsa_port *dp,
25 struct sk_buff *skb)
26 {
27 struct ocelot_8021q_tagger_private *priv = dp->ds->tagger_data;
28 struct ocelot_8021q_tagger_data *data = &priv->data;
29 void (*xmit_work_fn)(struct kthread_work *work);
30 struct felix_deferred_xmit_work *xmit_work;
31 struct kthread_worker *xmit_worker;
32
33 xmit_work_fn = data->xmit_work_fn;
34 xmit_worker = priv->xmit_worker;
35
36 if (!xmit_work_fn || !xmit_worker)
37 return NULL;
38
39 /* PTP over IP packets need UDP checksumming. We may have inherited
40 * NETIF_F_HW_CSUM from the DSA conduit, but these packets are not sent
41 * through the DSA conduit, so calculate the checksum here.
42 */
43 if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
44 return NULL;
45
46 xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
47 if (!xmit_work)
48 return NULL;
49
50 /* Calls felix_port_deferred_xmit in felix.c */
51 kthread_init_work(&xmit_work->work, xmit_work_fn);
52 /* Increase refcount so the kfree_skb in dsa_user_xmit
53 * won't really free the packet.
54 */
55 xmit_work->dp = dp;
56 xmit_work->skb = skb_get(skb);
57
58 kthread_queue_work(xmit_worker, &xmit_work->work);
59
60 return NULL;
61 }
62
ocelot_xmit(struct sk_buff * skb,struct net_device * netdev)63 static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
64 struct net_device *netdev)
65 {
66 struct dsa_port *dp = dsa_user_to_port(netdev);
67 u16 queue_mapping = skb_get_queue_mapping(skb);
68 u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
69 u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
70 struct ethhdr *hdr = eth_hdr(skb);
71
72 if (ocelot_ptp_rew_op(skb) || is_link_local_ether_addr(hdr->h_dest))
73 return ocelot_defer_xmit(dp, skb);
74
75 return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q,
76 ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
77 }
78
ocelot_rcv(struct sk_buff * skb,struct net_device * netdev)79 static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
80 struct net_device *netdev)
81 {
82 int src_port, switch_id;
83
84 dsa_8021q_rcv(skb, &src_port, &switch_id, NULL, NULL);
85
86 skb->dev = dsa_conduit_find_user(netdev, switch_id, src_port);
87 if (!skb->dev)
88 return NULL;
89
90 dsa_default_offload_fwd_mark(skb);
91
92 return skb;
93 }
94
ocelot_disconnect(struct dsa_switch * ds)95 static void ocelot_disconnect(struct dsa_switch *ds)
96 {
97 struct ocelot_8021q_tagger_private *priv = ds->tagger_data;
98
99 kthread_destroy_worker(priv->xmit_worker);
100 kfree(priv);
101 ds->tagger_data = NULL;
102 }
103
ocelot_connect(struct dsa_switch * ds)104 static int ocelot_connect(struct dsa_switch *ds)
105 {
106 struct ocelot_8021q_tagger_private *priv;
107 int err;
108
109 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
110 if (!priv)
111 return -ENOMEM;
112
113 priv->xmit_worker = kthread_create_worker(0, "felix_xmit");
114 if (IS_ERR(priv->xmit_worker)) {
115 err = PTR_ERR(priv->xmit_worker);
116 kfree(priv);
117 return err;
118 }
119
120 ds->tagger_data = priv;
121
122 return 0;
123 }
124
125 static const struct dsa_device_ops ocelot_8021q_netdev_ops = {
126 .name = OCELOT_8021Q_NAME,
127 .proto = DSA_TAG_PROTO_OCELOT_8021Q,
128 .xmit = ocelot_xmit,
129 .rcv = ocelot_rcv,
130 .connect = ocelot_connect,
131 .disconnect = ocelot_disconnect,
132 .needed_headroom = VLAN_HLEN,
133 .promisc_on_conduit = true,
134 };
135
136 MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using VLAN");
137 MODULE_LICENSE("GPL v2");
138 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT_8021Q, OCELOT_8021Q_NAME);
139
140 module_dsa_tag_driver(ocelot_8021q_netdev_ops);
141