net/dsa/tag_ocelot.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright 2019 NXP
0003  */
0004 #include <linux/dsa/ocelot.h>
0005 #include "dsa_priv.h"
0006
0007 /* If the port is under a VLAN-aware bridge, remove the VLAN header from the
0008  * payload and move it into the DSA tag, which will make the switch classify
0009  * the packet to the bridge VLAN. Otherwise, leave the classified VLAN at zero,
0010  * which is the pvid of standalone and VLAN-unaware bridge ports.
0011  */
0012 static void ocelot_xmit_get_vlan_info(struct sk_buff *skb, struct dsa_port *dp,
0013                       u64 *vlan_tci, u64 *tag_type)
0014 {
0015     struct net_device *br = dsa_port_bridge_dev_get(dp);
0016     struct vlan_ethhdr *hdr;
0017     u16 proto, tci;
0018
0019     if (!br || !br_vlan_enabled(br)) {
0020         *vlan_tci = 0;
0021         *tag_type = IFH_TAG_TYPE_C;
0022         return;
0023     }
0024
0025     hdr = (struct vlan_ethhdr *)skb_mac_header(skb);
0026     br_vlan_get_proto(br, &proto);
0027
0028     if (ntohs(hdr->h_vlan_proto) == proto) {
0029         __skb_vlan_pop(skb, &tci);
0030         *vlan_tci = tci;
0031     } else {
0032         rcu_read_lock();
0033         br_vlan_get_pvid_rcu(br, &tci);
0034         rcu_read_unlock();
0035         *vlan_tci = tci;
0036     }
0037
0038     *tag_type = (proto != ETH_P_8021Q) ? IFH_TAG_TYPE_S : IFH_TAG_TYPE_C;
0039 }
0040
0041 static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
0042                    __be32 ifh_prefix, void **ifh)
0043 {
0044     struct dsa_port *dp = dsa_slave_to_port(netdev);
0045     struct dsa_switch *ds = dp->ds;
0046     u64 vlan_tci, tag_type;
0047     void *injection;
0048     __be32 *prefix;
0049     u32 rew_op = 0;
0050     u64 qos_class;
0051
0052     ocelot_xmit_get_vlan_info(skb, dp, &vlan_tci, &tag_type);
0053
0054     qos_class = netdev_get_num_tc(netdev) ?
0055             netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
0056
0057     injection = skb_push(skb, OCELOT_TAG_LEN);
0058     prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
0059
0060     *prefix = ifh_prefix;
0061     memset(injection, 0, OCELOT_TAG_LEN);
0062     ocelot_ifh_set_bypass(injection, 1);
0063     ocelot_ifh_set_src(injection, ds->num_ports);
0064     ocelot_ifh_set_qos_class(injection, qos_class);
0065     ocelot_ifh_set_vlan_tci(injection, vlan_tci);
0066     ocelot_ifh_set_tag_type(injection, tag_type);
0067
0068     rew_op = ocelot_ptp_rew_op(skb);
0069     if (rew_op)
0070         ocelot_ifh_set_rew_op(injection, rew_op);
0071
0072     *ifh = injection;
0073 }
0074
0075 static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
0076                    struct net_device *netdev)
0077 {
0078     struct dsa_port *dp = dsa_slave_to_port(netdev);
0079     void *injection;
0080
0081     ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
0082     ocelot_ifh_set_dest(injection, BIT_ULL(dp->index));
0083
0084     return skb;
0085 }
0086
0087 static struct sk_buff *seville_xmit(struct sk_buff *skb,
0088                     struct net_device *netdev)
0089 {
0090     struct dsa_port *dp = dsa_slave_to_port(netdev);
0091     void *injection;
0092
0093     ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
0094     seville_ifh_set_dest(injection, BIT_ULL(dp->index));
0095
0096     return skb;
0097 }
0098
0099 static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
0100                   struct net_device *netdev)
0101 {
0102     u64 src_port, qos_class;
0103     u64 vlan_tci, tag_type;
0104     u8 *start = skb->data;
0105     struct dsa_port *dp;
0106     u8 *extraction;
0107     u16 vlan_tpid;
0108     u64 rew_val;
0109
0110     /* Revert skb->data by the amount consumed by the DSA master,
0111      * so it points to the beginning of the frame.
0112      */
0113     skb_push(skb, ETH_HLEN);
0114     /* We don't care about the short prefix, it is just for easy entrance
0115      * into the DSA master's RX filter. Discard it now by moving it into
0116      * the headroom.
0117      */
0118     skb_pull(skb, OCELOT_SHORT_PREFIX_LEN);
0119     /* And skb->data now points to the extraction frame header.
0120      * Keep a pointer to it.
0121      */
0122     extraction = skb->data;
0123     /* Now the EFH is part of the headroom as well */
0124     skb_pull(skb, OCELOT_TAG_LEN);
0125     /* Reset the pointer to the real MAC header */
0126     skb_reset_mac_header(skb);
0127     skb_reset_mac_len(skb);
0128     /* And move skb->data to the correct location again */
0129     skb_pull(skb, ETH_HLEN);
0130
0131     /* Remove from inet csum the extraction header */
0132     skb_postpull_rcsum(skb, start, OCELOT_TOTAL_TAG_LEN);
0133
0134     ocelot_xfh_get_src_port(extraction, &src_port);
0135     ocelot_xfh_get_qos_class(extraction, &qos_class);
0136     ocelot_xfh_get_tag_type(extraction, &tag_type);
0137     ocelot_xfh_get_vlan_tci(extraction, &vlan_tci);
0138     ocelot_xfh_get_rew_val(extraction, &rew_val);
0139
0140     skb->dev = dsa_master_find_slave(netdev, 0, src_port);
0141     if (!skb->dev)
0142         /* The switch will reflect back some frames sent through
0143          * sockets opened on the bare DSA master. These will come back
0144          * with src_port equal to the index of the CPU port, for which
0145          * there is no slave registered. So don't print any error
0146          * message here (ignore and drop those frames).
0147          */
0148         return NULL;
0149
0150     dsa_default_offload_fwd_mark(skb);
0151     skb->priority = qos_class;
0152     OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;
0153
0154     /* Ocelot switches copy frames unmodified to the CPU. However, it is
0155      * possible for the user to request a VLAN modification through
0156      * VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
0157      * the VLAN ID field from the Extraction Header gets updated, but the
0158      * 802.1Q header does not (the classified VLAN only becomes visible on
0159      * egress through the "port tag" of front-panel ports).
0160      * So, for traffic extracted by the CPU, we want to pick up the
0161      * classified VLAN and manually replace the existing 802.1Q header from
0162      * the packet with it, so that the operating system is always up to
0163      * date with the result of tc-vlan actions.
0164      * NOTE: In VLAN-unaware mode, we don't want to do that, we want the
0165      * frame to remain unmodified, because the classified VLAN is always
0166      * equal to the pvid of the ingress port and should not be used for
0167      * processing.
0168      */
0169     dp = dsa_slave_to_port(skb->dev);
0170     vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
0171
0172     if (dsa_port_is_vlan_filtering(dp) &&
0173         eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
0174         u16 dummy_vlan_tci;
0175
0176         skb_push_rcsum(skb, ETH_HLEN);
0177         __skb_vlan_pop(skb, &dummy_vlan_tci);
0178         skb_pull_rcsum(skb, ETH_HLEN);
0179         __vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
0180     }
0181
0182     return skb;
0183 }
0184
0185 static const struct dsa_device_ops ocelot_netdev_ops = {
0186     .name           = "ocelot",
0187     .proto          = DSA_TAG_PROTO_OCELOT,
0188     .xmit           = ocelot_xmit,
0189     .rcv            = ocelot_rcv,
0190     .needed_headroom    = OCELOT_TOTAL_TAG_LEN,
0191     .promisc_on_master  = true,
0192 };
0193
0194 DSA_TAG_DRIVER(ocelot_netdev_ops);
0195 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT);
0196
0197 static const struct dsa_device_ops seville_netdev_ops = {
0198     .name           = "seville",
0199     .proto          = DSA_TAG_PROTO_SEVILLE,
0200     .xmit           = seville_xmit,
0201     .rcv            = ocelot_rcv,
0202     .needed_headroom    = OCELOT_TOTAL_TAG_LEN,
0203     .promisc_on_master  = true,
0204 };
0205
0206 DSA_TAG_DRIVER(seville_netdev_ops);
0207 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE);
0208
0209 static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
0210     &DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
0211     &DSA_TAG_DRIVER_NAME(seville_netdev_ops),
0212 };
0213
0214 module_dsa_tag_drivers(ocelot_tag_driver_array);
0215
0216 MODULE_LICENSE("GPL v2");