xref: /openbmc/linux/net/dsa/tag_qca.c (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
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