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_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 
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_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 
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_conduit = true,
120 };
121 
122 MODULE_DESCRIPTION("DSA tag driver for Qualcomm Atheros QCA8K switches");
123 MODULE_LICENSE("GPL");
124 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA, QCA_NAME);
125 
126 module_dsa_tag_driver(qca_netdev_ops);
127