net/dsa/tag_sja1105.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
0003  */
0004 #include <linux/if_vlan.h>
0005 #include <linux/dsa/sja1105.h>
0006 #include <linux/dsa/8021q.h>
0007 #include <linux/packing.h>
0008 #include "dsa_priv.h"
0009
0010 /* Is this a TX or an RX header? */
0011 #define SJA1110_HEADER_HOST_TO_SWITCH       BIT(15)
0012
0013 /* RX header */
0014 #define SJA1110_RX_HEADER_IS_METADATA       BIT(14)
0015 #define SJA1110_RX_HEADER_HOST_ONLY     BIT(13)
0016 #define SJA1110_RX_HEADER_HAS_TRAILER       BIT(12)
0017
0018 /* Trap-to-host format (no trailer present) */
0019 #define SJA1110_RX_HEADER_SRC_PORT(x)       (((x) & GENMASK(7, 4)) >> 4)
0020 #define SJA1110_RX_HEADER_SWITCH_ID(x)      ((x) & GENMASK(3, 0))
0021
0022 /* Timestamp format (trailer present) */
0023 #define SJA1110_RX_HEADER_TRAILER_POS(x)    ((x) & GENMASK(11, 0))
0024
0025 #define SJA1110_RX_TRAILER_SWITCH_ID(x)     (((x) & GENMASK(7, 4)) >> 4)
0026 #define SJA1110_RX_TRAILER_SRC_PORT(x)      ((x) & GENMASK(3, 0))
0027
0028 /* Meta frame format (for 2-step TX timestamps) */
0029 #define SJA1110_RX_HEADER_N_TS(x)       (((x) & GENMASK(8, 4)) >> 4)
0030
0031 /* TX header */
0032 #define SJA1110_TX_HEADER_UPDATE_TC     BIT(14)
0033 #define SJA1110_TX_HEADER_TAKE_TS       BIT(13)
0034 #define SJA1110_TX_HEADER_TAKE_TS_CASC      BIT(12)
0035 #define SJA1110_TX_HEADER_HAS_TRAILER       BIT(11)
0036
0037 /* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is false */
0038 #define SJA1110_TX_HEADER_PRIO(x)       (((x) << 7) & GENMASK(10, 7))
0039 #define SJA1110_TX_HEADER_TSTAMP_ID(x)      ((x) & GENMASK(7, 0))
0040
0041 /* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is true */
0042 #define SJA1110_TX_HEADER_TRAILER_POS(x)    ((x) & GENMASK(10, 0))
0043
0044 #define SJA1110_TX_TRAILER_TSTAMP_ID(x)     (((x) << 24) & GENMASK(31, 24))
0045 #define SJA1110_TX_TRAILER_PRIO(x)      (((x) << 21) & GENMASK(23, 21))
0046 #define SJA1110_TX_TRAILER_SWITCHID(x)      (((x) << 12) & GENMASK(15, 12))
0047 #define SJA1110_TX_TRAILER_DESTPORTS(x)     (((x) << 1) & GENMASK(11, 1))
0048
0049 #define SJA1110_META_TSTAMP_SIZE        10
0050
0051 #define SJA1110_HEADER_LEN          4
0052 #define SJA1110_RX_TRAILER_LEN          13
0053 #define SJA1110_TX_TRAILER_LEN          4
0054 #define SJA1110_MAX_PADDING_LEN         15
0055
0056 #define SJA1105_HWTS_RX_EN          0
0057
0058 struct sja1105_tagger_private {
0059     struct sja1105_tagger_data data; /* Must be first */
0060     unsigned long state;
0061     /* Protects concurrent access to the meta state machine
0062      * from taggers running on multiple ports on SMP systems
0063      */
0064     spinlock_t meta_lock;
0065     struct sk_buff *stampable_skb;
0066     struct kthread_worker *xmit_worker;
0067 };
0068
0069 static struct sja1105_tagger_private *
0070 sja1105_tagger_private(struct dsa_switch *ds)
0071 {
0072     return ds->tagger_data;
0073 }
0074
0075 /* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
0076 static inline bool sja1105_is_link_local(const struct sk_buff *skb)
0077 {
0078     const struct ethhdr *hdr = eth_hdr(skb);
0079     u64 dmac = ether_addr_to_u64(hdr->h_dest);
0080
0081     if (ntohs(hdr->h_proto) == ETH_P_SJA1105_META)
0082         return false;
0083     if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) ==
0084             SJA1105_LINKLOCAL_FILTER_A)
0085         return true;
0086     if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) ==
0087             SJA1105_LINKLOCAL_FILTER_B)
0088         return true;
0089     return false;
0090 }
0091
0092 struct sja1105_meta {
0093     u64 tstamp;
0094     u64 dmac_byte_4;
0095     u64 dmac_byte_3;
0096     u64 source_port;
0097     u64 switch_id;
0098 };
0099
0100 static void sja1105_meta_unpack(const struct sk_buff *skb,
0101                 struct sja1105_meta *meta)
0102 {
0103     u8 *buf = skb_mac_header(skb) + ETH_HLEN;
0104
0105     /* UM10944.pdf section 4.2.17 AVB Parameters:
0106      * Structure of the meta-data follow-up frame.
0107      * It is in network byte order, so there are no quirks
0108      * while unpacking the meta frame.
0109      *
0110      * Also SJA1105 E/T only populates bits 23:0 of the timestamp
0111      * whereas P/Q/R/S does 32 bits. Since the structure is the
0112      * same and the E/T puts zeroes in the high-order byte, use
0113      * a unified unpacking command for both device series.
0114      */
0115     packing(buf,     &meta->tstamp,     31, 0, 4, UNPACK, 0);
0116     packing(buf + 4, &meta->dmac_byte_4, 7, 0, 1, UNPACK, 0);
0117     packing(buf + 5, &meta->dmac_byte_3, 7, 0, 1, UNPACK, 0);
0118     packing(buf + 6, &meta->source_port, 7, 0, 1, UNPACK, 0);
0119     packing(buf + 7, &meta->switch_id,   7, 0, 1, UNPACK, 0);
0120 }
0121
0122 static inline bool sja1105_is_meta_frame(const struct sk_buff *skb)
0123 {
0124     const struct ethhdr *hdr = eth_hdr(skb);
0125     u64 smac = ether_addr_to_u64(hdr->h_source);
0126     u64 dmac = ether_addr_to_u64(hdr->h_dest);
0127
0128     if (smac != SJA1105_META_SMAC)
0129         return false;
0130     if (dmac != SJA1105_META_DMAC)
0131         return false;
0132     if (ntohs(hdr->h_proto) != ETH_P_SJA1105_META)
0133         return false;
0134     return true;
0135 }
0136
0137 /* Calls sja1105_port_deferred_xmit in sja1105_main.c */
0138 static struct sk_buff *sja1105_defer_xmit(struct dsa_port *dp,
0139                       struct sk_buff *skb)
0140 {
0141     struct sja1105_tagger_data *tagger_data = sja1105_tagger_data(dp->ds);
0142     struct sja1105_tagger_private *priv = sja1105_tagger_private(dp->ds);
0143     void (*xmit_work_fn)(struct kthread_work *work);
0144     struct sja1105_deferred_xmit_work *xmit_work;
0145     struct kthread_worker *xmit_worker;
0146
0147     xmit_work_fn = tagger_data->xmit_work_fn;
0148     xmit_worker = priv->xmit_worker;
0149
0150     if (!xmit_work_fn || !xmit_worker)
0151         return NULL;
0152
0153     xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
0154     if (!xmit_work)
0155         return NULL;
0156
0157     kthread_init_work(&xmit_work->work, xmit_work_fn);
0158     /* Increase refcount so the kfree_skb in dsa_slave_xmit
0159      * won't really free the packet.
0160      */
0161     xmit_work->dp = dp;
0162     xmit_work->skb = skb_get(skb);
0163
0164     kthread_queue_work(xmit_worker, &xmit_work->work);
0165
0166     return NULL;
0167 }
0168
0169 /* Send VLAN tags with a TPID that blends in with whatever VLAN protocol a
0170  * bridge spanning ports of this switch might have.
0171  */
0172 static u16 sja1105_xmit_tpid(struct dsa_port *dp)
0173 {
0174     struct dsa_switch *ds = dp->ds;
0175     struct dsa_port *other_dp;
0176     u16 proto;
0177
0178     /* Since VLAN awareness is global, then if this port is VLAN-unaware,
0179      * all ports are. Use the VLAN-unaware TPID used for tag_8021q.
0180      */
0181     if (!dsa_port_is_vlan_filtering(dp))
0182         return ETH_P_SJA1105;
0183
0184     /* Port is VLAN-aware, so there is a bridge somewhere (a single one,
0185      * we're sure about that). It may not be on this port though, so we
0186      * need to find it.
0187      */
0188     dsa_switch_for_each_port(other_dp, ds) {
0189         struct net_device *br = dsa_port_bridge_dev_get(other_dp);
0190
0191         if (!br)
0192             continue;
0193
0194         /* Error is returned only if CONFIG_BRIDGE_VLAN_FILTERING,
0195          * which seems pointless to handle, as our port cannot become
0196          * VLAN-aware in that case.
0197          */
0198         br_vlan_get_proto(br, &proto);
0199
0200         return proto;
0201     }
0202
0203     WARN_ONCE(1, "Port is VLAN-aware but cannot find associated bridge!\n");
0204
0205     return ETH_P_SJA1105;
0206 }
0207
0208 static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
0209                           struct net_device *netdev)
0210 {
0211     struct dsa_port *dp = dsa_slave_to_port(netdev);
0212     unsigned int bridge_num = dsa_port_bridge_num_get(dp);
0213     struct net_device *br = dsa_port_bridge_dev_get(dp);
0214     u16 tx_vid;
0215
0216     /* If the port is under a VLAN-aware bridge, just slide the
0217      * VLAN-tagged packet into the FDB and hope for the best.
0218      * This works because we support a single VLAN-aware bridge
0219      * across the entire dst, and its VLANs cannot be shared with
0220      * any standalone port.
0221      */
0222     if (br_vlan_enabled(br))
0223         return skb;
0224
0225     /* If the port is under a VLAN-unaware bridge, use an imprecise
0226      * TX VLAN that targets the bridge's entire broadcast domain,
0227      * instead of just the specific port.
0228      */
0229     tx_vid = dsa_tag_8021q_bridge_vid(bridge_num);
0230
0231     return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp), tx_vid);
0232 }
0233
0234 /* Transform untagged control packets into pvid-tagged control packets so that
0235  * all packets sent by this tagger are VLAN-tagged and we can configure the
0236  * switch to drop untagged packets coming from the DSA master.
0237  */
0238 static struct sk_buff *sja1105_pvid_tag_control_pkt(struct dsa_port *dp,
0239                             struct sk_buff *skb, u8 pcp)
0240 {
0241     __be16 xmit_tpid = htons(sja1105_xmit_tpid(dp));
0242     struct vlan_ethhdr *hdr;
0243
0244     /* If VLAN tag is in hwaccel area, move it to the payload
0245      * to deal with both cases uniformly and to ensure that
0246      * the VLANs are added in the right order.
0247      */
0248     if (unlikely(skb_vlan_tag_present(skb))) {
0249         skb = __vlan_hwaccel_push_inside(skb);
0250         if (!skb)
0251             return NULL;
0252     }
0253
0254     hdr = (struct vlan_ethhdr *)skb_mac_header(skb);
0255
0256     /* If skb is already VLAN-tagged, leave that VLAN ID in place */
0257     if (hdr->h_vlan_proto == xmit_tpid)
0258         return skb;
0259
0260     return vlan_insert_tag(skb, xmit_tpid, (pcp << VLAN_PRIO_SHIFT) |
0261                    SJA1105_DEFAULT_VLAN);
0262 }
0263
0264 static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
0265                     struct net_device *netdev)
0266 {
0267     struct dsa_port *dp = dsa_slave_to_port(netdev);
0268     u16 queue_mapping = skb_get_queue_mapping(skb);
0269     u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
0270     u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
0271
0272     if (skb->offload_fwd_mark)
0273         return sja1105_imprecise_xmit(skb, netdev);
0274
0275     /* Transmitting management traffic does not rely upon switch tagging,
0276      * but instead SPI-installed management routes. Part 2 of this
0277      * is the .port_deferred_xmit driver callback.
0278      */
0279     if (unlikely(sja1105_is_link_local(skb))) {
0280         skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
0281         if (!skb)
0282             return NULL;
0283
0284         return sja1105_defer_xmit(dp, skb);
0285     }
0286
0287     return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
0288                  ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
0289 }
0290
0291 static struct sk_buff *sja1110_xmit(struct sk_buff *skb,
0292                     struct net_device *netdev)
0293 {
0294     struct sk_buff *clone = SJA1105_SKB_CB(skb)->clone;
0295     struct dsa_port *dp = dsa_slave_to_port(netdev);
0296     u16 queue_mapping = skb_get_queue_mapping(skb);
0297     u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
0298     u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
0299     __be32 *tx_trailer;
0300     __be16 *tx_header;
0301     int trailer_pos;
0302
0303     if (skb->offload_fwd_mark)
0304         return sja1105_imprecise_xmit(skb, netdev);
0305
0306     /* Transmitting control packets is done using in-band control
0307      * extensions, while data packets are transmitted using
0308      * tag_8021q TX VLANs.
0309      */
0310     if (likely(!sja1105_is_link_local(skb)))
0311         return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
0312                      ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
0313
0314     skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
0315     if (!skb)
0316         return NULL;
0317
0318     skb_push(skb, SJA1110_HEADER_LEN);
0319
0320     dsa_alloc_etype_header(skb, SJA1110_HEADER_LEN);
0321
0322     trailer_pos = skb->len;
0323
0324     tx_header = dsa_etype_header_pos_tx(skb);
0325     tx_trailer = skb_put(skb, SJA1110_TX_TRAILER_LEN);
0326
0327     tx_header[0] = htons(ETH_P_SJA1110);
0328     tx_header[1] = htons(SJA1110_HEADER_HOST_TO_SWITCH |
0329                  SJA1110_TX_HEADER_HAS_TRAILER |
0330                  SJA1110_TX_HEADER_TRAILER_POS(trailer_pos));
0331     *tx_trailer = cpu_to_be32(SJA1110_TX_TRAILER_PRIO(pcp) |
0332                   SJA1110_TX_TRAILER_SWITCHID(dp->ds->index) |
0333                   SJA1110_TX_TRAILER_DESTPORTS(BIT(dp->index)));
0334     if (clone) {
0335         u8 ts_id = SJA1105_SKB_CB(clone)->ts_id;
0336
0337         tx_header[1] |= htons(SJA1110_TX_HEADER_TAKE_TS);
0338         *tx_trailer |= cpu_to_be32(SJA1110_TX_TRAILER_TSTAMP_ID(ts_id));
0339     }
0340
0341     return skb;
0342 }
0343
0344 static void sja1105_transfer_meta(struct sk_buff *skb,
0345                   const struct sja1105_meta *meta)
0346 {
0347     struct ethhdr *hdr = eth_hdr(skb);
0348
0349     hdr->h_dest[3] = meta->dmac_byte_3;
0350     hdr->h_dest[4] = meta->dmac_byte_4;
0351     SJA1105_SKB_CB(skb)->tstamp = meta->tstamp;
0352 }
0353
0354 /* This is a simple state machine which follows the hardware mechanism of
0355  * generating RX timestamps:
0356  *
0357  * After each timestampable skb (all traffic for which send_meta1 and
0358  * send_meta0 is true, aka all MAC-filtered link-local traffic) a meta frame
0359  * containing a partial timestamp is immediately generated by the switch and
0360  * sent as a follow-up to the link-local frame on the CPU port.
0361  *
0362  * The meta frames have no unique identifier (such as sequence number) by which
0363  * one may pair them to the correct timestampable frame.
0364  * Instead, the switch has internal logic that ensures no frames are sent on
0365  * the CPU port between a link-local timestampable frame and its corresponding
0366  * meta follow-up. It also ensures strict ordering between ports (lower ports
0367  * have higher priority towards the CPU port). For this reason, a per-port
0368  * data structure is not needed/desirable.
0369  *
0370  * This function pairs the link-local frame with its partial timestamp from the
0371  * meta follow-up frame. The full timestamp will be reconstructed later in a
0372  * work queue.
0373  */
0374 static struct sk_buff
0375 *sja1105_rcv_meta_state_machine(struct sk_buff *skb,
0376                 struct sja1105_meta *meta,
0377                 bool is_link_local,
0378                 bool is_meta)
0379 {
0380     /* Step 1: A timestampable frame was received.
0381      * Buffer it until we get its meta frame.
0382      */
0383     if (is_link_local) {
0384         struct dsa_port *dp = dsa_slave_to_port(skb->dev);
0385         struct sja1105_tagger_private *priv;
0386         struct dsa_switch *ds = dp->ds;
0387
0388         priv = sja1105_tagger_private(ds);
0389
0390         if (!test_bit(SJA1105_HWTS_RX_EN, &priv->state))
0391             /* Do normal processing. */
0392             return skb;
0393
0394         spin_lock(&priv->meta_lock);
0395         /* Was this a link-local frame instead of the meta
0396          * that we were expecting?
0397          */
0398         if (priv->stampable_skb) {
0399             dev_err_ratelimited(ds->dev,
0400                         "Expected meta frame, is %12llx "
0401                         "in the DSA master multicast filter?\n",
0402                         SJA1105_META_DMAC);
0403             kfree_skb(priv->stampable_skb);
0404         }
0405
0406         /* Hold a reference to avoid dsa_switch_rcv
0407          * from freeing the skb.
0408          */
0409         priv->stampable_skb = skb_get(skb);
0410         spin_unlock(&priv->meta_lock);
0411
0412         /* Tell DSA we got nothing */
0413         return NULL;
0414
0415     /* Step 2: The meta frame arrived.
0416      * Time to take the stampable skb out of the closet, annotate it
0417      * with the partial timestamp, and pretend that we received it
0418      * just now (basically masquerade the buffered frame as the meta
0419      * frame, which serves no further purpose).
0420      */
0421     } else if (is_meta) {
0422         struct dsa_port *dp = dsa_slave_to_port(skb->dev);
0423         struct sja1105_tagger_private *priv;
0424         struct dsa_switch *ds = dp->ds;
0425         struct sk_buff *stampable_skb;
0426
0427         priv = sja1105_tagger_private(ds);
0428
0429         /* Drop the meta frame if we're not in the right state
0430          * to process it.
0431          */
0432         if (!test_bit(SJA1105_HWTS_RX_EN, &priv->state))
0433             return NULL;
0434
0435         spin_lock(&priv->meta_lock);
0436
0437         stampable_skb = priv->stampable_skb;
0438         priv->stampable_skb = NULL;
0439
0440         /* Was this a meta frame instead of the link-local
0441          * that we were expecting?
0442          */
0443         if (!stampable_skb) {
0444             dev_err_ratelimited(ds->dev,
0445                         "Unexpected meta frame\n");
0446             spin_unlock(&priv->meta_lock);
0447             return NULL;
0448         }
0449
0450         if (stampable_skb->dev != skb->dev) {
0451             dev_err_ratelimited(ds->dev,
0452                         "Meta frame on wrong port\n");
0453             spin_unlock(&priv->meta_lock);
0454             return NULL;
0455         }
0456
0457         /* Free the meta frame and give DSA the buffered stampable_skb
0458          * for further processing up the network stack.
0459          */
0460         kfree_skb(skb);
0461         skb = stampable_skb;
0462         sja1105_transfer_meta(skb, meta);
0463
0464         spin_unlock(&priv->meta_lock);
0465     }
0466
0467     return skb;
0468 }
0469
0470 static bool sja1105_rxtstamp_get_state(struct dsa_switch *ds)
0471 {
0472     struct sja1105_tagger_private *priv = sja1105_tagger_private(ds);
0473
0474     return test_bit(SJA1105_HWTS_RX_EN, &priv->state);
0475 }
0476
0477 static void sja1105_rxtstamp_set_state(struct dsa_switch *ds, bool on)
0478 {
0479     struct sja1105_tagger_private *priv = sja1105_tagger_private(ds);
0480
0481     if (on)
0482         set_bit(SJA1105_HWTS_RX_EN, &priv->state);
0483     else
0484         clear_bit(SJA1105_HWTS_RX_EN, &priv->state);
0485
0486     /* Initialize the meta state machine to a known state */
0487     if (!priv->stampable_skb)
0488         return;
0489
0490     kfree_skb(priv->stampable_skb);
0491     priv->stampable_skb = NULL;
0492 }
0493
0494 static bool sja1105_skb_has_tag_8021q(const struct sk_buff *skb)
0495 {
0496     u16 tpid = ntohs(eth_hdr(skb)->h_proto);
0497
0498     return tpid == ETH_P_SJA1105 || tpid == ETH_P_8021Q ||
0499            skb_vlan_tag_present(skb);
0500 }
0501
0502 static bool sja1110_skb_has_inband_control_extension(const struct sk_buff *skb)
0503 {
0504     return ntohs(eth_hdr(skb)->h_proto) == ETH_P_SJA1110;
0505 }
0506
0507 /* If the VLAN in the packet is a tag_8021q one, set @source_port and
0508  * @switch_id and strip the header. Otherwise set @vid and keep it in the
0509  * packet.
0510  */
0511 static void sja1105_vlan_rcv(struct sk_buff *skb, int *source_port,
0512                  int *switch_id, int *vbid, u16 *vid)
0513 {
0514     struct vlan_ethhdr *hdr = (struct vlan_ethhdr *)skb_mac_header(skb);
0515     u16 vlan_tci;
0516
0517     if (skb_vlan_tag_present(skb))
0518         vlan_tci = skb_vlan_tag_get(skb);
0519     else
0520         vlan_tci = ntohs(hdr->h_vlan_TCI);
0521
0522     if (vid_is_dsa_8021q(vlan_tci & VLAN_VID_MASK))
0523         return dsa_8021q_rcv(skb, source_port, switch_id, vbid);
0524
0525     /* Try our best with imprecise RX */
0526     *vid = vlan_tci & VLAN_VID_MASK;
0527 }
0528
0529 static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
0530                    struct net_device *netdev)
0531 {
0532     int source_port = -1, switch_id = -1, vbid = -1;
0533     struct sja1105_meta meta = {0};
0534     struct ethhdr *hdr;
0535     bool is_link_local;
0536     bool is_meta;
0537     u16 vid;
0538
0539     hdr = eth_hdr(skb);
0540     is_link_local = sja1105_is_link_local(skb);
0541     is_meta = sja1105_is_meta_frame(skb);
0542
0543     if (sja1105_skb_has_tag_8021q(skb)) {
0544         /* Normal traffic path. */
0545         sja1105_vlan_rcv(skb, &source_port, &switch_id, &vbid, &vid);
0546     } else if (is_link_local) {
0547         /* Management traffic path. Switch embeds the switch ID and
0548          * port ID into bytes of the destination MAC, courtesy of
0549          * the incl_srcpt options.
0550          */
0551         source_port = hdr->h_dest[3];
0552         switch_id = hdr->h_dest[4];
0553         /* Clear the DMAC bytes that were mangled by the switch */
0554         hdr->h_dest[3] = 0;
0555         hdr->h_dest[4] = 0;
0556     } else if (is_meta) {
0557         sja1105_meta_unpack(skb, &meta);
0558         source_port = meta.source_port;
0559         switch_id = meta.switch_id;
0560     } else {
0561         return NULL;
0562     }
0563
0564     if (vbid >= 1)
0565         skb->dev = dsa_tag_8021q_find_port_by_vbid(netdev, vbid);
0566     else if (source_port == -1 || switch_id == -1)
0567         skb->dev = dsa_find_designated_bridge_port_by_vid(netdev, vid);
0568     else
0569         skb->dev = dsa_master_find_slave(netdev, switch_id, source_port);
0570     if (!skb->dev) {
0571         netdev_warn(netdev, "Couldn't decode source port\n");
0572         return NULL;
0573     }
0574
0575     if (!is_link_local)
0576         dsa_default_offload_fwd_mark(skb);
0577
0578     return sja1105_rcv_meta_state_machine(skb, &meta, is_link_local,
0579                           is_meta);
0580 }
0581
0582 static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
0583 {
0584     u8 *buf = dsa_etype_header_pos_rx(skb) + SJA1110_HEADER_LEN;
0585     int switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
0586     int n_ts = SJA1110_RX_HEADER_N_TS(rx_header);
0587     struct sja1105_tagger_data *tagger_data;
0588     struct net_device *master = skb->dev;
0589     struct dsa_port *cpu_dp;
0590     struct dsa_switch *ds;
0591     int i;
0592
0593     cpu_dp = master->dsa_ptr;
0594     ds = dsa_switch_find(cpu_dp->dst->index, switch_id);
0595     if (!ds) {
0596         net_err_ratelimited("%s: cannot find switch id %d\n",
0597                     master->name, switch_id);
0598         return NULL;
0599     }
0600
0601     tagger_data = sja1105_tagger_data(ds);
0602     if (!tagger_data->meta_tstamp_handler)
0603         return NULL;
0604
0605     for (i = 0; i <= n_ts; i++) {
0606         u8 ts_id, source_port, dir;
0607         u64 tstamp;
0608
0609         ts_id = buf[0];
0610         source_port = (buf[1] & GENMASK(7, 4)) >> 4;
0611         dir = (buf[1] & BIT(3)) >> 3;
0612         tstamp = be64_to_cpu(*(__be64 *)(buf + 2));
0613
0614         tagger_data->meta_tstamp_handler(ds, source_port, ts_id, dir,
0615                          tstamp);
0616
0617         buf += SJA1110_META_TSTAMP_SIZE;
0618     }
0619
0620     /* Discard the meta frame, we've consumed the timestamps it contained */
0621     return NULL;
0622 }
0623
0624 static struct sk_buff *sja1110_rcv_inband_control_extension(struct sk_buff *skb,
0625                                 int *source_port,
0626                                 int *switch_id,
0627                                 bool *host_only)
0628 {
0629     u16 rx_header;
0630
0631     if (unlikely(!pskb_may_pull(skb, SJA1110_HEADER_LEN)))
0632         return NULL;
0633
0634     /* skb->data points to skb_mac_header(skb) + ETH_HLEN, which is exactly
0635      * what we need because the caller has checked the EtherType (which is
0636      * located 2 bytes back) and we just need a pointer to the header that
0637      * comes afterwards.
0638      */
0639     rx_header = ntohs(*(__be16 *)skb->data);
0640
0641     if (rx_header & SJA1110_RX_HEADER_HOST_ONLY)
0642         *host_only = true;
0643
0644     if (rx_header & SJA1110_RX_HEADER_IS_METADATA)
0645         return sja1110_rcv_meta(skb, rx_header);
0646
0647     /* Timestamp frame, we have a trailer */
0648     if (rx_header & SJA1110_RX_HEADER_HAS_TRAILER) {
0649         int start_of_padding = SJA1110_RX_HEADER_TRAILER_POS(rx_header);
0650         u8 *rx_trailer = skb_tail_pointer(skb) - SJA1110_RX_TRAILER_LEN;
0651         u64 *tstamp = &SJA1105_SKB_CB(skb)->tstamp;
0652         u8 last_byte = rx_trailer[12];
0653
0654         /* The timestamp is unaligned, so we need to use packing()
0655          * to get it
0656          */
0657         packing(rx_trailer, tstamp, 63, 0, 8, UNPACK, 0);
0658
0659         *source_port = SJA1110_RX_TRAILER_SRC_PORT(last_byte);
0660         *switch_id = SJA1110_RX_TRAILER_SWITCH_ID(last_byte);
0661
0662         /* skb->len counts from skb->data, while start_of_padding
0663          * counts from the destination MAC address. Right now skb->data
0664          * is still as set by the DSA master, so to trim away the
0665          * padding and trailer we need to account for the fact that
0666          * skb->data points to skb_mac_header(skb) + ETH_HLEN.
0667          */
0668         pskb_trim_rcsum(skb, start_of_padding - ETH_HLEN);
0669     /* Trap-to-host frame, no timestamp trailer */
0670     } else {
0671         *source_port = SJA1110_RX_HEADER_SRC_PORT(rx_header);
0672         *switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
0673     }
0674
0675     /* Advance skb->data past the DSA header */
0676     skb_pull_rcsum(skb, SJA1110_HEADER_LEN);
0677
0678     dsa_strip_etype_header(skb, SJA1110_HEADER_LEN);
0679
0680     /* With skb->data in its final place, update the MAC header
0681      * so that eth_hdr() continues to works properly.
0682      */
0683     skb_set_mac_header(skb, -ETH_HLEN);
0684
0685     return skb;
0686 }
0687
0688 static struct sk_buff *sja1110_rcv(struct sk_buff *skb,
0689                    struct net_device *netdev)
0690 {
0691     int source_port = -1, switch_id = -1, vbid = -1;
0692     bool host_only = false;
0693     u16 vid = 0;
0694
0695     if (sja1110_skb_has_inband_control_extension(skb)) {
0696         skb = sja1110_rcv_inband_control_extension(skb, &source_port,
0697                                &switch_id,
0698                                &host_only);
0699         if (!skb)
0700             return NULL;
0701     }
0702
0703     /* Packets with in-band control extensions might still have RX VLANs */
0704     if (likely(sja1105_skb_has_tag_8021q(skb)))
0705         sja1105_vlan_rcv(skb, &source_port, &switch_id, &vbid, &vid);
0706
0707     if (vbid >= 1)
0708         skb->dev = dsa_tag_8021q_find_port_by_vbid(netdev, vbid);
0709     else if (source_port == -1 || switch_id == -1)
0710         skb->dev = dsa_find_designated_bridge_port_by_vid(netdev, vid);
0711     else
0712         skb->dev = dsa_master_find_slave(netdev, switch_id, source_port);
0713     if (!skb->dev) {
0714         netdev_warn(netdev, "Couldn't decode source port\n");
0715         return NULL;
0716     }
0717
0718     if (!host_only)
0719         dsa_default_offload_fwd_mark(skb);
0720
0721     return skb;
0722 }
0723
0724 static void sja1105_flow_dissect(const struct sk_buff *skb, __be16 *proto,
0725                  int *offset)
0726 {
0727     /* No tag added for management frames, all ok */
0728     if (unlikely(sja1105_is_link_local(skb)))
0729         return;
0730
0731     dsa_tag_generic_flow_dissect(skb, proto, offset);
0732 }
0733
0734 static void sja1110_flow_dissect(const struct sk_buff *skb, __be16 *proto,
0735                  int *offset)
0736 {
0737     /* Management frames have 2 DSA tags on RX, so the needed_headroom we
0738      * declared is fine for the generic dissector adjustment procedure.
0739      */
0740     if (unlikely(sja1105_is_link_local(skb)))
0741         return dsa_tag_generic_flow_dissect(skb, proto, offset);
0742
0743     /* For the rest, there is a single DSA tag, the tag_8021q one */
0744     *offset = VLAN_HLEN;
0745     *proto = ((__be16 *)skb->data)[(VLAN_HLEN / 2) - 1];
0746 }
0747
0748 static void sja1105_disconnect(struct dsa_switch *ds)
0749 {
0750     struct sja1105_tagger_private *priv = ds->tagger_data;
0751
0752     kthread_destroy_worker(priv->xmit_worker);
0753     kfree(priv);
0754     ds->tagger_data = NULL;
0755 }
0756
0757 static int sja1105_connect(struct dsa_switch *ds)
0758 {
0759     struct sja1105_tagger_data *tagger_data;
0760     struct sja1105_tagger_private *priv;
0761     struct kthread_worker *xmit_worker;
0762     int err;
0763
0764     priv = kzalloc(sizeof(*priv), GFP_KERNEL);
0765     if (!priv)
0766         return -ENOMEM;
0767
0768     spin_lock_init(&priv->meta_lock);
0769
0770     xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",
0771                         ds->dst->index, ds->index);
0772     if (IS_ERR(xmit_worker)) {
0773         err = PTR_ERR(xmit_worker);
0774         kfree(priv);
0775         return err;
0776     }
0777
0778     priv->xmit_worker = xmit_worker;
0779     /* Export functions for switch driver use */
0780     tagger_data = &priv->data;
0781     tagger_data->rxtstamp_get_state = sja1105_rxtstamp_get_state;
0782     tagger_data->rxtstamp_set_state = sja1105_rxtstamp_set_state;
0783     ds->tagger_data = priv;
0784
0785     return 0;
0786 }
0787
0788 static const struct dsa_device_ops sja1105_netdev_ops = {
0789     .name = "sja1105",
0790     .proto = DSA_TAG_PROTO_SJA1105,
0791     .xmit = sja1105_xmit,
0792     .rcv = sja1105_rcv,
0793     .connect = sja1105_connect,
0794     .disconnect = sja1105_disconnect,
0795     .needed_headroom = VLAN_HLEN,
0796     .flow_dissect = sja1105_flow_dissect,
0797     .promisc_on_master = true,
0798 };
0799
0800 DSA_TAG_DRIVER(sja1105_netdev_ops);
0801 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105);
0802
0803 static const struct dsa_device_ops sja1110_netdev_ops = {
0804     .name = "sja1110",
0805     .proto = DSA_TAG_PROTO_SJA1110,
0806     .xmit = sja1110_xmit,
0807     .rcv = sja1110_rcv,
0808     .connect = sja1105_connect,
0809     .disconnect = sja1105_disconnect,
0810     .flow_dissect = sja1110_flow_dissect,
0811     .needed_headroom = SJA1110_HEADER_LEN + VLAN_HLEN,
0812     .needed_tailroom = SJA1110_RX_TRAILER_LEN + SJA1110_MAX_PADDING_LEN,
0813 };
0814
0815 DSA_TAG_DRIVER(sja1110_netdev_ops);
0816 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1110);
0817
0818 static struct dsa_tag_driver *sja1105_tag_driver_array[] = {
0819     &DSA_TAG_DRIVER_NAME(sja1105_netdev_ops),
0820     &DSA_TAG_DRIVER_NAME(sja1110_netdev_ops),
0821 };
0822
0823 module_dsa_tag_drivers(sja1105_tag_driver_array);
0824
0825 MODULE_LICENSE("GPL v2");