tag_ocelot.c

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