1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 NXP
3 */
4#include <linux/dsa/ocelot.h>
5
6#include "tag.h"
7
8#define OCELOT_NAME	"ocelot"
9#define SEVILLE_NAME	"seville"
10
11/* If the port is under a VLAN-aware bridge, remove the VLAN header from the
12 * payload and move it into the DSA tag, which will make the switch classify
13 * the packet to the bridge VLAN. Otherwise, leave the classified VLAN at zero,
14 * which is the pvid of standalone and VLAN-unaware bridge ports.
15 */
16static void ocelot_xmit_get_vlan_info(struct sk_buff *skb, struct dsa_port *dp,
17				      u64 *vlan_tci, u64 *tag_type)
18{
19	struct net_device *br = dsa_port_bridge_dev_get(dp);
20	struct vlan_ethhdr *hdr;
21	u16 proto, tci;
22
23	if (!br || !br_vlan_enabled(br)) {
24		*vlan_tci = 0;
25		*tag_type = IFH_TAG_TYPE_C;
26		return;
27	}
28
29	hdr = skb_vlan_eth_hdr(skb);
30	br_vlan_get_proto(br, &proto);
31
32	if (ntohs(hdr->h_vlan_proto) == proto) {
33		vlan_remove_tag(skb, &tci);
34		*vlan_tci = tci;
35	} else {
36		rcu_read_lock();
37		br_vlan_get_pvid_rcu(br, &tci);
38		rcu_read_unlock();
39		*vlan_tci = tci;
40	}
41
42	*tag_type = (proto != ETH_P_8021Q) ? IFH_TAG_TYPE_S : IFH_TAG_TYPE_C;
43}
44
45static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
46			       __be32 ifh_prefix, void **ifh)
47{
48	struct dsa_port *dp = dsa_user_to_port(netdev);
49	struct dsa_switch *ds = dp->ds;
50	u64 vlan_tci, tag_type;
51	void *injection;
52	__be32 *prefix;
53	u32 rew_op = 0;
54	u64 qos_class;
55
56	ocelot_xmit_get_vlan_info(skb, dp, &vlan_tci, &tag_type);
57
58	qos_class = netdev_get_num_tc(netdev) ?
59		    netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
60
61	injection = skb_push(skb, OCELOT_TAG_LEN);
62	prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
63
64	*prefix = ifh_prefix;
65	memset(injection, 0, OCELOT_TAG_LEN);
66	ocelot_ifh_set_bypass(injection, 1);
67	ocelot_ifh_set_src(injection, ds->num_ports);
68	ocelot_ifh_set_qos_class(injection, qos_class);
69	ocelot_ifh_set_vlan_tci(injection, vlan_tci);
70	ocelot_ifh_set_tag_type(injection, tag_type);
71
72	rew_op = ocelot_ptp_rew_op(skb);
73	if (rew_op)
74		ocelot_ifh_set_rew_op(injection, rew_op);
75
76	*ifh = injection;
77}
78
79static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
80				   struct net_device *netdev)
81{
82	struct dsa_port *dp = dsa_user_to_port(netdev);
83	void *injection;
84
85	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
86	ocelot_ifh_set_dest(injection, BIT_ULL(dp->index));
87
88	return skb;
89}
90
91static struct sk_buff *seville_xmit(struct sk_buff *skb,
92				    struct net_device *netdev)
93{
94	struct dsa_port *dp = dsa_user_to_port(netdev);
95	void *injection;
96
97	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
98	seville_ifh_set_dest(injection, BIT_ULL(dp->index));
99
100	return skb;
101}
102
103static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
104				  struct net_device *netdev)
105{
106	u64 src_port, qos_class;
107	u64 vlan_tci, tag_type;
108	u8 *start = skb->data;
109	struct dsa_port *dp;
110	u8 *extraction;
111	u16 vlan_tpid;
112	u64 rew_val;
113
114	/* Revert skb->data by the amount consumed by the DSA conduit,
115	 * so it points to the beginning of the frame.
116	 */
117	skb_push(skb, ETH_HLEN);
118	/* We don't care about the short prefix, it is just for easy entrance
119	 * into the DSA conduit's RX filter. Discard it now by moving it into
120	 * the headroom.
121	 */
122	skb_pull(skb, OCELOT_SHORT_PREFIX_LEN);
123	/* And skb->data now points to the extraction frame header.
124	 * Keep a pointer to it.
125	 */
126	extraction = skb->data;
127	/* Now the EFH is part of the headroom as well */
128	skb_pull(skb, OCELOT_TAG_LEN);
129	/* Reset the pointer to the real MAC header */
130	skb_reset_mac_header(skb);
131	skb_reset_mac_len(skb);
132	/* And move skb->data to the correct location again */
133	skb_pull(skb, ETH_HLEN);
134
135	/* Remove from inet csum the extraction header */
136	skb_postpull_rcsum(skb, start, OCELOT_TOTAL_TAG_LEN);
137
138	ocelot_xfh_get_src_port(extraction, &src_port);
139	ocelot_xfh_get_qos_class(extraction, &qos_class);
140	ocelot_xfh_get_tag_type(extraction, &tag_type);
141	ocelot_xfh_get_vlan_tci(extraction, &vlan_tci);
142	ocelot_xfh_get_rew_val(extraction, &rew_val);
143
144	skb->dev = dsa_conduit_find_user(netdev, 0, src_port);
145	if (!skb->dev)
146		/* The switch will reflect back some frames sent through
147		 * sockets opened on the bare DSA conduit. These will come back
148		 * with src_port equal to the index of the CPU port, for which
149		 * there is no user registered. So don't print any error
150		 * message here (ignore and drop those frames).
151		 */
152		return NULL;
153
154	dsa_default_offload_fwd_mark(skb);
155	skb->priority = qos_class;
156	OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;
157
158	/* Ocelot switches copy frames unmodified to the CPU. However, it is
159	 * possible for the user to request a VLAN modification through
160	 * VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
161	 * the VLAN ID field from the Extraction Header gets updated, but the
162	 * 802.1Q header does not (the classified VLAN only becomes visible on
163	 * egress through the "port tag" of front-panel ports).
164	 * So, for traffic extracted by the CPU, we want to pick up the
165	 * classified VLAN and manually replace the existing 802.1Q header from
166	 * the packet with it, so that the operating system is always up to
167	 * date with the result of tc-vlan actions.
168	 * NOTE: In VLAN-unaware mode, we don't want to do that, we want the
169	 * frame to remain unmodified, because the classified VLAN is always
170	 * equal to the pvid of the ingress port and should not be used for
171	 * processing.
172	 */
173	dp = dsa_user_to_port(skb->dev);
174	vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
175
176	if (dsa_port_is_vlan_filtering(dp) &&
177	    eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
178		u16 dummy_vlan_tci;
179
180		skb_push_rcsum(skb, ETH_HLEN);
181		__skb_vlan_pop(skb, &dummy_vlan_tci);
182		skb_pull_rcsum(skb, ETH_HLEN);
183		__vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
184	}
185
186	return skb;
187}
188
189static const struct dsa_device_ops ocelot_netdev_ops = {
190	.name			= OCELOT_NAME,
191	.proto			= DSA_TAG_PROTO_OCELOT,
192	.xmit			= ocelot_xmit,
193	.rcv			= ocelot_rcv,
194	.needed_headroom	= OCELOT_TOTAL_TAG_LEN,
195	.promisc_on_conduit	= true,
196};
197
198DSA_TAG_DRIVER(ocelot_netdev_ops);
199MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT, OCELOT_NAME);
200
201static const struct dsa_device_ops seville_netdev_ops = {
202	.name			= SEVILLE_NAME,
203	.proto			= DSA_TAG_PROTO_SEVILLE,
204	.xmit			= seville_xmit,
205	.rcv			= ocelot_rcv,
206	.needed_headroom	= OCELOT_TOTAL_TAG_LEN,
207	.promisc_on_conduit	= true,
208};
209
210DSA_TAG_DRIVER(seville_netdev_ops);
211MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE, SEVILLE_NAME);
212
213static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
214	&DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
215	&DSA_TAG_DRIVER_NAME(seville_netdev_ops),
216};
217
218module_dsa_tag_drivers(ocelot_tag_driver_array);
219
220MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using NPI port");
221MODULE_LICENSE("GPL v2");
222