tag_qca.c

  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	__be16 *phdr;
 18	u16 hdr;
 19
 20	skb_push(skb, QCA_HDR_LEN);
 21
 22	dsa_alloc_etype_header(skb, QCA_HDR_LEN);
 23	phdr = dsa_etype_header_pos_tx(skb);
 24
 25	/* Set the version field, and set destination port information */
 26	hdr = FIELD_PREP(QCA_HDR_XMIT_VERSION, QCA_HDR_VERSION);
 27	hdr |= QCA_HDR_XMIT_FROM_CPU;
 28	hdr |= FIELD_PREP(QCA_HDR_XMIT_DP_BIT, dsa_xmit_port_mask(skb, dev));
 29
 30	*phdr = htons(hdr);
 31
 32	return skb;
 33}
 34
 35static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 36{
 37	struct qca_tagger_data *tagger_data;
 38	struct dsa_port *dp = dev->dsa_ptr;
 39	struct dsa_switch *ds = dp->ds;
 40	u8 ver, pk_type;
 41	__be16 *phdr;
 42	int port;
 43	u16 hdr;
 44
 45	BUILD_BUG_ON(sizeof(struct qca_mgmt_ethhdr) != QCA_HDR_MGMT_HEADER_LEN + QCA_HDR_LEN);
 46
 47	tagger_data = ds->tagger_data;
 48
 49	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
 50		return NULL;
 51
 52	phdr = dsa_etype_header_pos_rx(skb);
 53	hdr = ntohs(*phdr);
 54
 55	/* Make sure the version is correct */
 56	ver = FIELD_GET(QCA_HDR_RECV_VERSION, hdr);
 57	if (unlikely(ver != QCA_HDR_VERSION))
 58		return NULL;
 59
 60	/* Get pk type */
 61	pk_type = FIELD_GET(QCA_HDR_RECV_TYPE, hdr);
 62
 63	/* Ethernet mgmt read/write packet */
 64	if (pk_type == QCA_HDR_RECV_TYPE_RW_REG_ACK) {
 65		if (likely(tagger_data->rw_reg_ack_handler))
 66			tagger_data->rw_reg_ack_handler(ds, skb);
 67		return NULL;
 68	}
 69
 70	/* Ethernet MIB counter packet */
 71	if (pk_type == QCA_HDR_RECV_TYPE_MIB) {
 72		if (likely(tagger_data->mib_autocast_handler))
 73			tagger_data->mib_autocast_handler(ds, skb);
 74		return NULL;
 75	}
 76
 77	/* Get source port information */
 78	port = FIELD_GET(QCA_HDR_RECV_SOURCE_PORT, hdr);
 79
 80	skb->dev = dsa_conduit_find_user(dev, 0, port);
 81	if (!skb->dev)
 82		return NULL;
 83
 84	/* Remove QCA tag and recalculate checksum */
 85	skb_pull_rcsum(skb, QCA_HDR_LEN);
 86	dsa_strip_etype_header(skb, QCA_HDR_LEN);
 87
 88	return skb;
 89}
 90
 91static int qca_tag_connect(struct dsa_switch *ds)
 92{
 93	struct qca_tagger_data *tagger_data;
 94
 95	tagger_data = kzalloc(sizeof(*tagger_data), GFP_KERNEL);
 96	if (!tagger_data)
 97		return -ENOMEM;
 98
 99	ds->tagger_data = tagger_data;
100
101	return 0;
102}
103
104static void qca_tag_disconnect(struct dsa_switch *ds)
105{
106	kfree(ds->tagger_data);
107	ds->tagger_data = NULL;
108}
109
110static const struct dsa_device_ops qca_netdev_ops = {
111	.name	= QCA_NAME,
112	.proto	= DSA_TAG_PROTO_QCA,
113	.connect = qca_tag_connect,
114	.disconnect = qca_tag_disconnect,
115	.xmit	= qca_tag_xmit,
116	.rcv	= qca_tag_rcv,
117	.needed_headroom = QCA_HDR_LEN,
118	.promisc_on_conduit = true,
119};
120
121MODULE_DESCRIPTION("DSA tag driver for Qualcomm Atheros QCA8K switches");
122MODULE_LICENSE("GPL");
123MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA, QCA_NAME);
124
125module_dsa_tag_driver(qca_netdev_ops);