1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
4 */
5
6 #include <linux/etherdevice.h>
7 #include <linux/bitfield.h>
8 #include <net/dsa.h>
9 #include <linux/dsa/tag_qca.h>
10
11 #include "tag.h"
12
13 #define QCA_NAME "qca"
14
qca_tag_xmit(struct sk_buff * skb,struct net_device * dev)15 static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
16 {
17 struct dsa_port *dp = dsa_slave_to_port(dev);
18 __be16 *phdr;
19 u16 hdr;
20
21 skb_push(skb, QCA_HDR_LEN);
22
23 dsa_alloc_etype_header(skb, QCA_HDR_LEN);
24 phdr = dsa_etype_header_pos_tx(skb);
25
26 /* Set the version field, and set destination port information */
27 hdr = FIELD_PREP(QCA_HDR_XMIT_VERSION, QCA_HDR_VERSION);
28 hdr |= QCA_HDR_XMIT_FROM_CPU;
29 hdr |= FIELD_PREP(QCA_HDR_XMIT_DP_BIT, BIT(dp->index));
30
31 *phdr = htons(hdr);
32
33 return skb;
34 }
35
qca_tag_rcv(struct sk_buff * skb,struct net_device * dev)36 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
37 {
38 struct qca_tagger_data *tagger_data;
39 struct dsa_port *dp = dev->dsa_ptr;
40 struct dsa_switch *ds = dp->ds;
41 u8 ver, pk_type;
42 __be16 *phdr;
43 int port;
44 u16 hdr;
45
46 BUILD_BUG_ON(sizeof(struct qca_mgmt_ethhdr) != QCA_HDR_MGMT_HEADER_LEN + QCA_HDR_LEN);
47
48 tagger_data = ds->tagger_data;
49
50 if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
51 return NULL;
52
53 phdr = dsa_etype_header_pos_rx(skb);
54 hdr = ntohs(*phdr);
55
56 /* Make sure the version is correct */
57 ver = FIELD_GET(QCA_HDR_RECV_VERSION, hdr);
58 if (unlikely(ver != QCA_HDR_VERSION))
59 return NULL;
60
61 /* Get pk type */
62 pk_type = FIELD_GET(QCA_HDR_RECV_TYPE, hdr);
63
64 /* Ethernet mgmt read/write packet */
65 if (pk_type == QCA_HDR_RECV_TYPE_RW_REG_ACK) {
66 if (likely(tagger_data->rw_reg_ack_handler))
67 tagger_data->rw_reg_ack_handler(ds, skb);
68 return NULL;
69 }
70
71 /* Ethernet MIB counter packet */
72 if (pk_type == QCA_HDR_RECV_TYPE_MIB) {
73 if (likely(tagger_data->mib_autocast_handler))
74 tagger_data->mib_autocast_handler(ds, skb);
75 return NULL;
76 }
77
78 /* Get source port information */
79 port = FIELD_GET(QCA_HDR_RECV_SOURCE_PORT, hdr);
80
81 skb->dev = dsa_master_find_slave(dev, 0, port);
82 if (!skb->dev)
83 return NULL;
84
85 /* Remove QCA tag and recalculate checksum */
86 skb_pull_rcsum(skb, QCA_HDR_LEN);
87 dsa_strip_etype_header(skb, QCA_HDR_LEN);
88
89 return skb;
90 }
91
qca_tag_connect(struct dsa_switch * ds)92 static int qca_tag_connect(struct dsa_switch *ds)
93 {
94 struct qca_tagger_data *tagger_data;
95
96 tagger_data = kzalloc(sizeof(*tagger_data), GFP_KERNEL);
97 if (!tagger_data)
98 return -ENOMEM;
99
100 ds->tagger_data = tagger_data;
101
102 return 0;
103 }
104
qca_tag_disconnect(struct dsa_switch * ds)105 static void qca_tag_disconnect(struct dsa_switch *ds)
106 {
107 kfree(ds->tagger_data);
108 ds->tagger_data = NULL;
109 }
110
111 static const struct dsa_device_ops qca_netdev_ops = {
112 .name = QCA_NAME,
113 .proto = DSA_TAG_PROTO_QCA,
114 .connect = qca_tag_connect,
115 .disconnect = qca_tag_disconnect,
116 .xmit = qca_tag_xmit,
117 .rcv = qca_tag_rcv,
118 .needed_headroom = QCA_HDR_LEN,
119 .promisc_on_master = true,
120 };
121
122 MODULE_LICENSE("GPL");
123 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA, QCA_NAME);
124
125 module_dsa_tag_driver(qca_netdev_ops);
126