net/dsa/tag_ocelot.c

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