net/dsa/tag_ksz.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
   4  * Copyright (c) 2017 Microchip Technology
   5  */
   6
   7 #include <linux/dsa/ksz_common.h>
   8 #include <linux/etherdevice.h>
   9 #include <linux/list.h>
  10 #include <linux/ptp_classify.h>
  11 #include <net/dsa.h>
  12
  13 #include "tag.h"
  14
  15 #define KSZ8795_NAME "ksz8795"
  16 #define KSZ9477_NAME "ksz9477"
  17 #define KSZ9893_NAME "ksz9893"
  18 #define LAN937X_NAME "lan937x"
  19
  20 /* Typically only one byte is used for tail tag. */
  21 #define KSZ_PTP_TAG_LEN                 4
  22 #define KSZ_EGRESS_TAG_LEN              1
  23 #define KSZ_INGRESS_TAG_LEN             1
  24
  25 #define KSZ_HWTS_EN  0
  26
  27 struct ksz_tagger_private {
  28         struct ksz_tagger_data data; /* Must be first */
  29         unsigned long state;
  30         struct kthread_worker *xmit_worker;
  31 };
  32
  33 static struct ksz_tagger_private *
  34 ksz_tagger_private(struct dsa_switch *ds)
  35 {
  36         return ds->tagger_data;
  37 }
  38
  39 static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
  40 {
  41         struct ksz_tagger_private *priv = ksz_tagger_private(ds);
  42
  43         if (on)
  44                 set_bit(KSZ_HWTS_EN, &priv->state);
  45         else
  46                 clear_bit(KSZ_HWTS_EN, &priv->state);
  47 }
  48
  49 static void ksz_disconnect(struct dsa_switch *ds)
  50 {
  51         struct ksz_tagger_private *priv = ds->tagger_data;
  52
  53         kthread_destroy_worker(priv->xmit_worker);
  54         kfree(priv);
  55         ds->tagger_data = NULL;
  56 }
  57
  58 static int ksz_connect(struct dsa_switch *ds)
  59 {
  60         struct ksz_tagger_data *tagger_data;
  61         struct kthread_worker *xmit_worker;
  62         struct ksz_tagger_private *priv;
  63         int ret;
  64
  65         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
  66         if (!priv)
  67                 return -ENOMEM;
  68
  69         xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",
  70                                             ds->dst->index, ds->index);
  71         if (IS_ERR(xmit_worker)) {
  72                 ret = PTR_ERR(xmit_worker);
  73                 kfree(priv);
  74                 return ret;
  75         }
  76
  77         priv->xmit_worker = xmit_worker;
  78         /* Export functions for switch driver use */
  79         tagger_data = &priv->data;
  80         tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
  81         ds->tagger_data = priv;
  82
  83         return 0;
  84 }
  85
  86 static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
  87                                       struct net_device *dev,
  88                                       unsigned int port, unsigned int len)
  89 {
  90         skb->dev = dsa_master_find_slave(dev, 0, port);
  91         if (!skb->dev)
  92                 return NULL;
  93
  94         if (pskb_trim_rcsum(skb, skb->len - len))
  95                 return NULL;
  96
  97         dsa_default_offload_fwd_mark(skb);
  98
  99         return skb;
 100 }
 101
 102 /*
 103  * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
 104  * ---------------------------------------------------------------------------
 105  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
 106  * ---------------------------------------------------------------------------
 107  * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
 108  *
 109  * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
 110  * ---------------------------------------------------------------------------
 111  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
 112  * ---------------------------------------------------------------------------
 113  * tag0 : zero-based value represents port
 114  *        (eg, 0x00=port1, 0x02=port3, 0x06=port7)
 115  */
 116
 117 #define KSZ8795_TAIL_TAG_OVERRIDE       BIT(6)
 118 #define KSZ8795_TAIL_TAG_LOOKUP         BIT(7)
 119
 120 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
 121 {
 122         struct dsa_port *dp = dsa_slave_to_port(dev);
 123         struct ethhdr *hdr;
 124         u8 *tag;
 125
 126         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 127                 return NULL;
 128
 129         /* Tag encoding */
 130         tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 131         hdr = skb_eth_hdr(skb);
 132
 133         *tag = 1 << dp->index;
 134         if (is_link_local_ether_addr(hdr->h_dest))
 135                 *tag |= KSZ8795_TAIL_TAG_OVERRIDE;
 136
 137         return skb;
 138 }
 139
 140 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
 141 {
 142         u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 143
 144         return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
 145 }
 146
 147 static const struct dsa_device_ops ksz8795_netdev_ops = {
 148         .name   = KSZ8795_NAME,
 149         .proto  = DSA_TAG_PROTO_KSZ8795,
 150         .xmit   = ksz8795_xmit,
 151         .rcv    = ksz8795_rcv,
 152         .needed_tailroom = KSZ_INGRESS_TAG_LEN,
 153 };
 154
 155 DSA_TAG_DRIVER(ksz8795_netdev_ops);
 156 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
 157
 158 /*
 159  * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
 160  * ---------------------------------------------------------------------------
 161  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
 162  * FCS(4bytes)
 163  * ---------------------------------------------------------------------------
 164  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
 165  * tag0 : Prioritization (not used now)
 166  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
 167  *
 168  * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
 169  * ---------------------------------------------------------------------------
 170  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
 171  * ---------------------------------------------------------------------------
 172  * ts   : time stamp (Present only if bit 7 of tag0 is set)
 173  * tag0 : zero-based value represents port
 174  *        (eg, 0x00=port1, 0x02=port3, 0x06=port7)
 175  */
 176
 177 #define KSZ9477_INGRESS_TAG_LEN         2
 178 #define KSZ9477_PTP_TAG_LEN             4
 179 #define KSZ9477_PTP_TAG_INDICATION      0x80
 180
 181 #define KSZ9477_TAIL_TAG_PRIO           GENMASK(8, 7)
 182 #define KSZ9477_TAIL_TAG_OVERRIDE       BIT(9)
 183 #define KSZ9477_TAIL_TAG_LOOKUP         BIT(10)
 184
 185 static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
 186 {
 187         u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
 188         ktime_t tstamp;
 189
 190         tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
 191         KSZ_SKB_CB(skb)->tstamp = tstamp;
 192 }
 193
 194 /* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
 195  * Regardless of Whether it is a PTP frame or not.
 196  */
 197 static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
 198 {
 199         struct ksz_tagger_private *priv;
 200         struct ptp_header *ptp_hdr;
 201         unsigned int ptp_type;
 202         u32 tstamp_raw = 0;
 203         s64 correction;
 204
 205         priv = ksz_tagger_private(dp->ds);
 206
 207         if (!test_bit(KSZ_HWTS_EN, &priv->state))
 208                 return;
 209
 210         if (!KSZ_SKB_CB(skb)->update_correction)
 211                 goto output_tag;
 212
 213         ptp_type = KSZ_SKB_CB(skb)->ptp_type;
 214
 215         ptp_hdr = ptp_parse_header(skb, ptp_type);
 216         if (!ptp_hdr)
 217                 goto output_tag;
 218
 219         correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
 220
 221         if (correction < 0) {
 222                 struct timespec64 ts;
 223
 224                 ts = ns_to_timespec64(-correction >> 16);
 225                 tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
 226
 227                 /* Set correction field to 0 and update UDP checksum */
 228                 ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
 229         }
 230
 231 output_tag:
 232         put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
 233 }
 234
 235 /* Defer transmit if waiting for egress time stamp is required.  */
 236 static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
 237 {
 238         struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
 239         struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
 240         void (*xmit_work_fn)(struct kthread_work *work);
 241         struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
 242         struct ksz_deferred_xmit_work *xmit_work;
 243         struct kthread_worker *xmit_worker;
 244
 245         if (!clone)
 246                 return skb;  /* no deferred xmit for this packet */
 247
 248         xmit_work_fn = tagger_data->xmit_work_fn;
 249         xmit_worker = priv->xmit_worker;
 250
 251         if (!xmit_work_fn || !xmit_worker)
 252                 return NULL;
 253
 254         xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
 255         if (!xmit_work)
 256                 return NULL;
 257
 258         kthread_init_work(&xmit_work->work, xmit_work_fn);
 259         /* Increase refcount so the kfree_skb in dsa_slave_xmit
 260          * won't really free the packet.
 261          */
 262         xmit_work->dp = dp;
 263         xmit_work->skb = skb_get(skb);
 264
 265         kthread_queue_work(xmit_worker, &xmit_work->work);
 266
 267         return NULL;
 268 }
 269
 270 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 271                                     struct net_device *dev)
 272 {
 273         u16 queue_mapping = skb_get_queue_mapping(skb);
 274         u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 275         struct dsa_port *dp = dsa_slave_to_port(dev);
 276         struct ethhdr *hdr;
 277         __be16 *tag;
 278         u16 val;
 279
 280         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 281                 return NULL;
 282
 283         /* Tag encoding */
 284         ksz_xmit_timestamp(dp, skb);
 285
 286         tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
 287         hdr = skb_eth_hdr(skb);
 288
 289         val = BIT(dp->index);
 290
 291         val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);
 292
 293         if (is_link_local_ether_addr(hdr->h_dest))
 294                 val |= KSZ9477_TAIL_TAG_OVERRIDE;
 295
 296         *tag = cpu_to_be16(val);
 297
 298         return ksz_defer_xmit(dp, skb);
 299 }
 300
 301 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 302 {
 303         /* Tag decoding */
 304         u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 305         unsigned int port = tag[0] & 7;
 306         unsigned int len = KSZ_EGRESS_TAG_LEN;
 307
 308         /* Extra 4-bytes PTP timestamp */
 309         if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
 310                 ksz_rcv_timestamp(skb, tag);
 311                 len += KSZ_PTP_TAG_LEN;
 312         }
 313
 314         return ksz_common_rcv(skb, dev, port, len);
 315 }
 316
 317 static const struct dsa_device_ops ksz9477_netdev_ops = {
 318         .name   = KSZ9477_NAME,
 319         .proto  = DSA_TAG_PROTO_KSZ9477,
 320         .xmit   = ksz9477_xmit,
 321         .rcv    = ksz9477_rcv,
 322         .connect = ksz_connect,
 323         .disconnect = ksz_disconnect,
 324         .needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 325 };
 326
 327 DSA_TAG_DRIVER(ksz9477_netdev_ops);
 328 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);
 329
 330 #define KSZ9893_TAIL_TAG_PRIO           GENMASK(4, 3)
 331 #define KSZ9893_TAIL_TAG_OVERRIDE       BIT(5)
 332 #define KSZ9893_TAIL_TAG_LOOKUP         BIT(6)
 333
 334 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 335                                     struct net_device *dev)
 336 {
 337         u16 queue_mapping = skb_get_queue_mapping(skb);
 338         u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 339         struct dsa_port *dp = dsa_slave_to_port(dev);
 340         struct ethhdr *hdr;
 341         u8 *tag;
 342
 343         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 344                 return NULL;
 345
 346         /* Tag encoding */
 347         ksz_xmit_timestamp(dp, skb);
 348
 349         tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 350         hdr = skb_eth_hdr(skb);
 351
 352         *tag = BIT(dp->index);
 353
 354         *tag |= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);
 355
 356         if (is_link_local_ether_addr(hdr->h_dest))
 357                 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
 358
 359         return ksz_defer_xmit(dp, skb);
 360 }
 361
 362 static const struct dsa_device_ops ksz9893_netdev_ops = {
 363         .name   = KSZ9893_NAME,
 364         .proto  = DSA_TAG_PROTO_KSZ9893,
 365         .xmit   = ksz9893_xmit,
 366         .rcv    = ksz9477_rcv,
 367         .connect = ksz_connect,
 368         .disconnect = ksz_disconnect,
 369         .needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 370 };
 371
 372 DSA_TAG_DRIVER(ksz9893_netdev_ops);
 373 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
 374
 375 /* For xmit, 2/6 bytes are added before FCS.
 376  * ---------------------------------------------------------------------------
 377  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
 378  * FCS(4bytes)
 379  * ---------------------------------------------------------------------------
 380  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
 381  * tag0 : represents tag override, lookup and valid
 382  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
 383  *
 384  * For rcv, 1/5 bytes is added before FCS.
 385  * ---------------------------------------------------------------------------
 386  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
 387  * ---------------------------------------------------------------------------
 388  * ts   : time stamp (Present only if bit 7 of tag0 is set)
 389  * tag0 : zero-based value represents port
 390  *        (eg, 0x00=port1, 0x02=port3, 0x07=port8)
 391  */
 392 #define LAN937X_EGRESS_TAG_LEN          2
 393
 394 #define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE      BIT(11)
 395 #define LAN937X_TAIL_TAG_LOOKUP                 BIT(12)
 396 #define LAN937X_TAIL_TAG_VALID                  BIT(13)
 397 #define LAN937X_TAIL_TAG_PRIO                   GENMASK(10, 8)
 398 #define LAN937X_TAIL_TAG_PORT_MASK              7
 399
 400 static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 401                                     struct net_device *dev)
 402 {
 403         u16 queue_mapping = skb_get_queue_mapping(skb);
 404         u8 prio = netdev_txq_to_tc(dev, queue_mapping);
 405         struct dsa_port *dp = dsa_slave_to_port(dev);
 406         const struct ethhdr *hdr = eth_hdr(skb);
 407         __be16 *tag;
 408         u16 val;
 409
 410         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 411                 return NULL;
 412
 413         ksz_xmit_timestamp(dp, skb);
 414
 415         tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
 416
 417         val = BIT(dp->index);
 418
 419         val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);
 420
 421         if (is_link_local_ether_addr(hdr->h_dest))
 422                 val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
 423
 424         /* Tail tag valid bit - This bit should always be set by the CPU */
 425         val |= LAN937X_TAIL_TAG_VALID;
 426
 427         put_unaligned_be16(val, tag);
 428
 429         return ksz_defer_xmit(dp, skb);
 430 }
 431
 432 static const struct dsa_device_ops lan937x_netdev_ops = {
 433         .name   = LAN937X_NAME,
 434         .proto  = DSA_TAG_PROTO_LAN937X,
 435         .xmit   = lan937x_xmit,
 436         .rcv    = ksz9477_rcv,
 437         .connect = ksz_connect,
 438         .disconnect = ksz_disconnect,
 439         .needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 440 };
 441
 442 DSA_TAG_DRIVER(lan937x_netdev_ops);
 443 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
 444
 445 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
 446         &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
 447         &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
 448         &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
 449         &DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
 450 };
 451
 452 module_dsa_tag_drivers(dsa_tag_driver_array);
 453
 454 MODULE_LICENSE("GPL");