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         u8 *tag;
 124         u8 *addr;
 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         addr = skb_mac_header(skb);
 132
 133         *tag = 1 << dp->index;
 134         if (is_link_local_ether_addr(addr))
 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_OVERRIDE       BIT(9)
 182 #define KSZ9477_TAIL_TAG_LOOKUP         BIT(10)
 183
 184 static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
 185 {
 186         u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
 187         ktime_t tstamp;
 188
 189         tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
 190         KSZ_SKB_CB(skb)->tstamp = tstamp;
 191 }
 192
 193 /* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
 194  * Regardless of Whether it is a PTP frame or not.
 195  */
 196 static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
 197 {
 198         struct ksz_tagger_private *priv;
 199         struct ptp_header *ptp_hdr;
 200         unsigned int ptp_type;
 201         u32 tstamp_raw = 0;
 202         s64 correction;
 203
 204         priv = ksz_tagger_private(dp->ds);
 205
 206         if (!test_bit(KSZ_HWTS_EN, &priv->state))
 207                 return;
 208
 209         if (!KSZ_SKB_CB(skb)->update_correction)
 210                 goto output_tag;
 211
 212         ptp_type = KSZ_SKB_CB(skb)->ptp_type;
 213
 214         ptp_hdr = ptp_parse_header(skb, ptp_type);
 215         if (!ptp_hdr)
 216                 goto output_tag;
 217
 218         correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
 219
 220         if (correction < 0) {
 221                 struct timespec64 ts;
 222
 223                 ts = ns_to_timespec64(-correction >> 16);
 224                 tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
 225
 226                 /* Set correction field to 0 and update UDP checksum */
 227                 ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
 228         }
 229
 230 output_tag:
 231         put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
 232 }
 233
 234 /* Defer transmit if waiting for egress time stamp is required.  */
 235 static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
 236 {
 237         struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
 238         struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
 239         void (*xmit_work_fn)(struct kthread_work *work);
 240         struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
 241         struct ksz_deferred_xmit_work *xmit_work;
 242         struct kthread_worker *xmit_worker;
 243
 244         if (!clone)
 245                 return skb;  /* no deferred xmit for this packet */
 246
 247         xmit_work_fn = tagger_data->xmit_work_fn;
 248         xmit_worker = priv->xmit_worker;
 249
 250         if (!xmit_work_fn || !xmit_worker)
 251                 return NULL;
 252
 253         xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
 254         if (!xmit_work)
 255                 return NULL;
 256
 257         kthread_init_work(&xmit_work->work, xmit_work_fn);
 258         /* Increase refcount so the kfree_skb in dsa_slave_xmit
 259          * won't really free the packet.
 260          */
 261         xmit_work->dp = dp;
 262         xmit_work->skb = skb_get(skb);
 263
 264         kthread_queue_work(xmit_worker, &xmit_work->work);
 265
 266         return NULL;
 267 }
 268
 269 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
 270                                     struct net_device *dev)
 271 {
 272         struct dsa_port *dp = dsa_slave_to_port(dev);
 273         __be16 *tag;
 274         u8 *addr;
 275         u16 val;
 276
 277         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 278                 return NULL;
 279
 280         /* Tag encoding */
 281         ksz_xmit_timestamp(dp, skb);
 282
 283         tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
 284         addr = skb_mac_header(skb);
 285
 286         val = BIT(dp->index);
 287
 288         if (is_link_local_ether_addr(addr))
 289                 val |= KSZ9477_TAIL_TAG_OVERRIDE;
 290
 291         *tag = cpu_to_be16(val);
 292
 293         return ksz_defer_xmit(dp, skb);
 294 }
 295
 296 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 297 {
 298         /* Tag decoding */
 299         u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 300         unsigned int port = tag[0] & 7;
 301         unsigned int len = KSZ_EGRESS_TAG_LEN;
 302
 303         /* Extra 4-bytes PTP timestamp */
 304         if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
 305                 ksz_rcv_timestamp(skb, tag);
 306                 len += KSZ_PTP_TAG_LEN;
 307         }
 308
 309         return ksz_common_rcv(skb, dev, port, len);
 310 }
 311
 312 static const struct dsa_device_ops ksz9477_netdev_ops = {
 313         .name   = KSZ9477_NAME,
 314         .proto  = DSA_TAG_PROTO_KSZ9477,
 315         .xmit   = ksz9477_xmit,
 316         .rcv    = ksz9477_rcv,
 317         .connect = ksz_connect,
 318         .disconnect = ksz_disconnect,
 319         .needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 320 };
 321
 322 DSA_TAG_DRIVER(ksz9477_netdev_ops);
 323 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);
 324
 325 #define KSZ9893_TAIL_TAG_OVERRIDE       BIT(5)
 326 #define KSZ9893_TAIL_TAG_LOOKUP         BIT(6)
 327
 328 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
 329                                     struct net_device *dev)
 330 {
 331         struct dsa_port *dp = dsa_slave_to_port(dev);
 332         u8 *addr;
 333         u8 *tag;
 334
 335         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 336                 return NULL;
 337
 338         /* Tag encoding */
 339         ksz_xmit_timestamp(dp, skb);
 340
 341         tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
 342         addr = skb_mac_header(skb);
 343
 344         *tag = BIT(dp->index);
 345
 346         if (is_link_local_ether_addr(addr))
 347                 *tag |= KSZ9893_TAIL_TAG_OVERRIDE;
 348
 349         return ksz_defer_xmit(dp, skb);
 350 }
 351
 352 static const struct dsa_device_ops ksz9893_netdev_ops = {
 353         .name   = KSZ9893_NAME,
 354         .proto  = DSA_TAG_PROTO_KSZ9893,
 355         .xmit   = ksz9893_xmit,
 356         .rcv    = ksz9477_rcv,
 357         .connect = ksz_connect,
 358         .disconnect = ksz_disconnect,
 359         .needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 360 };
 361
 362 DSA_TAG_DRIVER(ksz9893_netdev_ops);
 363 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
 364
 365 /* For xmit, 2/6 bytes are added before FCS.
 366  * ---------------------------------------------------------------------------
 367  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
 368  * FCS(4bytes)
 369  * ---------------------------------------------------------------------------
 370  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
 371  * tag0 : represents tag override, lookup and valid
 372  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
 373  *
 374  * For rcv, 1/5 bytes is added before FCS.
 375  * ---------------------------------------------------------------------------
 376  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
 377  * ---------------------------------------------------------------------------
 378  * ts   : time stamp (Present only if bit 7 of tag0 is set)
 379  * tag0 : zero-based value represents port
 380  *        (eg, 0x00=port1, 0x02=port3, 0x07=port8)
 381  */
 382 #define LAN937X_EGRESS_TAG_LEN          2
 383
 384 #define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE      BIT(11)
 385 #define LAN937X_TAIL_TAG_LOOKUP                 BIT(12)
 386 #define LAN937X_TAIL_TAG_VALID                  BIT(13)
 387 #define LAN937X_TAIL_TAG_PORT_MASK              7
 388
 389 static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
 390                                     struct net_device *dev)
 391 {
 392         struct dsa_port *dp = dsa_slave_to_port(dev);
 393         const struct ethhdr *hdr = eth_hdr(skb);
 394         __be16 *tag;
 395         u16 val;
 396
 397         if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
 398                 return NULL;
 399
 400         ksz_xmit_timestamp(dp, skb);
 401
 402         tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
 403
 404         val = BIT(dp->index);
 405
 406         if (is_link_local_ether_addr(hdr->h_dest))
 407                 val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
 408
 409         /* Tail tag valid bit - This bit should always be set by the CPU */
 410         val |= LAN937X_TAIL_TAG_VALID;
 411
 412         put_unaligned_be16(val, tag);
 413
 414         return ksz_defer_xmit(dp, skb);
 415 }
 416
 417 static const struct dsa_device_ops lan937x_netdev_ops = {
 418         .name   = LAN937X_NAME,
 419         .proto  = DSA_TAG_PROTO_LAN937X,
 420         .xmit   = lan937x_xmit,
 421         .rcv    = ksz9477_rcv,
 422         .connect = ksz_connect,
 423         .disconnect = ksz_disconnect,
 424         .needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
 425 };
 426
 427 DSA_TAG_DRIVER(lan937x_netdev_ops);
 428 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
 429
 430 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
 431         &DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
 432         &DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
 433         &DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
 434         &DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
 435 };
 436
 437 module_dsa_tag_drivers(dsa_tag_driver_array);
 438
 439 MODULE_LICENSE("GPL");