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
15static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
16{
17	struct dsa_port *dp = dsa_user_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
36static 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_conduit_find_user(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
92static 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
105static void qca_tag_disconnect(struct dsa_switch *ds)
106{
107	kfree(ds->tagger_data);
108	ds->tagger_data = NULL;
109}
110
111static 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_conduit = true,
120};
121
122MODULE_DESCRIPTION("DSA tag driver for Qualcomm Atheros QCA8K switches");
123MODULE_LICENSE("GPL");
124MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA, QCA_NAME);
125
126module_dsa_tag_driver(qca_netdev_ops);
127