1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Handling of a conduit device, switching frames via its switch fabric CPU port 4 * 5 * Copyright (c) 2017 Savoir-faire Linux Inc. 6 * Vivien Didelot <vivien.didelot@savoirfairelinux.com> 7 */ 8 9 #include <linux/ethtool.h> 10 #include <linux/netdevice.h> 11 #include <linux/netlink.h> 12 #include <net/dsa.h> 13 14 #include "conduit.h" 15 #include "dsa.h" 16 #include "port.h" 17 #include "tag.h" 18 19 static int dsa_conduit_get_regs_len(struct net_device *dev) 20 { 21 struct dsa_port *cpu_dp = dev->dsa_ptr; 22 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 23 struct dsa_switch *ds = cpu_dp->ds; 24 int port = cpu_dp->index; 25 int ret = 0; 26 int len; 27 28 if (ops->get_regs_len) { 29 len = ops->get_regs_len(dev); 30 if (len < 0) 31 return len; 32 ret += len; 33 } 34 35 ret += sizeof(struct ethtool_drvinfo); 36 ret += sizeof(struct ethtool_regs); 37 38 if (ds->ops->get_regs_len) { 39 len = ds->ops->get_regs_len(ds, port); 40 if (len < 0) 41 return len; 42 ret += len; 43 } 44 45 return ret; 46 } 47 48 static void dsa_conduit_get_regs(struct net_device *dev, 49 struct ethtool_regs *regs, void *data) 50 { 51 struct dsa_port *cpu_dp = dev->dsa_ptr; 52 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 53 struct dsa_switch *ds = cpu_dp->ds; 54 struct ethtool_drvinfo *cpu_info; 55 struct ethtool_regs *cpu_regs; 56 int port = cpu_dp->index; 57 int len; 58 59 if (ops->get_regs_len && ops->get_regs) { 60 len = ops->get_regs_len(dev); 61 if (len < 0) 62 return; 63 regs->len = len; 64 ops->get_regs(dev, regs, data); 65 data += regs->len; 66 } 67 68 cpu_info = (struct ethtool_drvinfo *)data; 69 strscpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver)); 70 data += sizeof(*cpu_info); 71 cpu_regs = (struct ethtool_regs *)data; 72 data += sizeof(*cpu_regs); 73 74 if (ds->ops->get_regs_len && ds->ops->get_regs) { 75 len = ds->ops->get_regs_len(ds, port); 76 if (len < 0) 77 return; 78 cpu_regs->len = len; 79 ds->ops->get_regs(ds, port, cpu_regs, data); 80 } 81 } 82 83 static void dsa_conduit_get_ethtool_stats(struct net_device *dev, 84 struct ethtool_stats *stats, 85 uint64_t *data) 86 { 87 struct dsa_port *cpu_dp = dev->dsa_ptr; 88 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 89 struct dsa_switch *ds = cpu_dp->ds; 90 int port = cpu_dp->index; 91 int count = 0; 92 93 if (ops->get_sset_count && ops->get_ethtool_stats) { 94 count = ops->get_sset_count(dev, ETH_SS_STATS); 95 ops->get_ethtool_stats(dev, stats, data); 96 } 97 98 if (ds->ops->get_ethtool_stats) 99 ds->ops->get_ethtool_stats(ds, port, data + count); 100 } 101 102 static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev, 103 struct ethtool_stats *stats, 104 uint64_t *data) 105 { 106 struct dsa_port *cpu_dp = dev->dsa_ptr; 107 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 108 struct dsa_switch *ds = cpu_dp->ds; 109 int port = cpu_dp->index; 110 int count = 0; 111 112 if (dev->phydev && !ops->get_ethtool_phy_stats) { 113 count = phy_ethtool_get_sset_count(dev->phydev); 114 if (count >= 0) 115 phy_ethtool_get_stats(dev->phydev, stats, data); 116 } else if (ops->get_sset_count && ops->get_ethtool_phy_stats) { 117 count = ops->get_sset_count(dev, ETH_SS_PHY_STATS); 118 ops->get_ethtool_phy_stats(dev, stats, data); 119 } 120 121 if (count < 0) 122 count = 0; 123 124 if (ds->ops->get_ethtool_phy_stats) 125 ds->ops->get_ethtool_phy_stats(ds, port, data + count); 126 } 127 128 static int dsa_conduit_get_sset_count(struct net_device *dev, int sset) 129 { 130 struct dsa_port *cpu_dp = dev->dsa_ptr; 131 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 132 struct dsa_switch *ds = cpu_dp->ds; 133 int count = 0; 134 135 if (sset == ETH_SS_PHY_STATS && dev->phydev && 136 !ops->get_ethtool_phy_stats) 137 count = phy_ethtool_get_sset_count(dev->phydev); 138 else if (ops->get_sset_count) 139 count = ops->get_sset_count(dev, sset); 140 141 if (count < 0) 142 count = 0; 143 144 if (ds->ops->get_sset_count) 145 count += ds->ops->get_sset_count(ds, cpu_dp->index, sset); 146 147 return count; 148 } 149 150 static void dsa_conduit_get_strings(struct net_device *dev, uint32_t stringset, 151 uint8_t *data) 152 { 153 struct dsa_port *cpu_dp = dev->dsa_ptr; 154 const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops; 155 struct dsa_switch *ds = cpu_dp->ds; 156 int port = cpu_dp->index; 157 int len = ETH_GSTRING_LEN; 158 int mcount = 0, count, i; 159 uint8_t pfx[4]; 160 uint8_t *ndata; 161 162 snprintf(pfx, sizeof(pfx), "p%.2d", port); 163 /* We do not want to be NULL-terminated, since this is a prefix */ 164 pfx[sizeof(pfx) - 1] = '_'; 165 166 if (stringset == ETH_SS_PHY_STATS && dev->phydev && 167 !ops->get_ethtool_phy_stats) { 168 mcount = phy_ethtool_get_sset_count(dev->phydev); 169 if (mcount < 0) 170 mcount = 0; 171 else 172 phy_ethtool_get_strings(dev->phydev, data); 173 } else if (ops->get_sset_count && ops->get_strings) { 174 mcount = ops->get_sset_count(dev, stringset); 175 if (mcount < 0) 176 mcount = 0; 177 ops->get_strings(dev, stringset, data); 178 } 179 180 if (ds->ops->get_strings) { 181 ndata = data + mcount * len; 182 /* This function copies ETH_GSTRINGS_LEN bytes, we will mangle 183 * the output after to prepend our CPU port prefix we 184 * constructed earlier 185 */ 186 ds->ops->get_strings(ds, port, stringset, ndata); 187 count = ds->ops->get_sset_count(ds, port, stringset); 188 if (count < 0) 189 return; 190 for (i = 0; i < count; i++) { 191 memmove(ndata + (i * len + sizeof(pfx)), 192 ndata + i * len, len - sizeof(pfx)); 193 memcpy(ndata + i * len, pfx, sizeof(pfx)); 194 } 195 } 196 } 197 198 /* Deny PTP operations on conduit if there is at least one switch in the tree 199 * that is PTP capable. 200 */ 201 int __dsa_conduit_hwtstamp_validate(struct net_device *dev, 202 const struct kernel_hwtstamp_config *config, 203 struct netlink_ext_ack *extack) 204 { 205 struct dsa_port *cpu_dp = dev->dsa_ptr; 206 struct dsa_switch *ds = cpu_dp->ds; 207 struct dsa_switch_tree *dst; 208 struct dsa_port *dp; 209 210 dst = ds->dst; 211 212 list_for_each_entry(dp, &dst->ports, list) { 213 if (dsa_port_supports_hwtstamp(dp)) { 214 NL_SET_ERR_MSG(extack, 215 "HW timestamping not allowed on DSA conduit when switch supports the operation"); 216 return -EBUSY; 217 } 218 } 219 220 return 0; 221 } 222 223 static int dsa_conduit_ethtool_setup(struct net_device *dev) 224 { 225 struct dsa_port *cpu_dp = dev->dsa_ptr; 226 struct dsa_switch *ds = cpu_dp->ds; 227 struct ethtool_ops *ops; 228 229 if (netif_is_lag_master(dev)) 230 return 0; 231 232 ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL); 233 if (!ops) 234 return -ENOMEM; 235 236 cpu_dp->orig_ethtool_ops = dev->ethtool_ops; 237 if (cpu_dp->orig_ethtool_ops) 238 memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops)); 239 240 ops->get_regs_len = dsa_conduit_get_regs_len; 241 ops->get_regs = dsa_conduit_get_regs; 242 ops->get_sset_count = dsa_conduit_get_sset_count; 243 ops->get_ethtool_stats = dsa_conduit_get_ethtool_stats; 244 ops->get_strings = dsa_conduit_get_strings; 245 ops->get_ethtool_phy_stats = dsa_conduit_get_ethtool_phy_stats; 246 247 dev->ethtool_ops = ops; 248 249 return 0; 250 } 251 252 static void dsa_conduit_ethtool_teardown(struct net_device *dev) 253 { 254 struct dsa_port *cpu_dp = dev->dsa_ptr; 255 256 if (netif_is_lag_master(dev)) 257 return; 258 259 dev->ethtool_ops = cpu_dp->orig_ethtool_ops; 260 cpu_dp->orig_ethtool_ops = NULL; 261 } 262 263 /* Keep the conduit always promiscuous if the tagging protocol requires that 264 * (garbles MAC DA) or if it doesn't support unicast filtering, case in which 265 * it would revert to promiscuous mode as soon as we call dev_uc_add() on it 266 * anyway. 267 */ 268 static void dsa_conduit_set_promiscuity(struct net_device *dev, int inc) 269 { 270 const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops; 271 272 if ((dev->priv_flags & IFF_UNICAST_FLT) && !ops->promisc_on_conduit) 273 return; 274 275 ASSERT_RTNL(); 276 277 dev_set_promiscuity(dev, inc); 278 } 279 280 static ssize_t tagging_show(struct device *d, struct device_attribute *attr, 281 char *buf) 282 { 283 struct net_device *dev = to_net_dev(d); 284 struct dsa_port *cpu_dp = dev->dsa_ptr; 285 286 return sysfs_emit(buf, "%s\n", 287 dsa_tag_protocol_to_str(cpu_dp->tag_ops)); 288 } 289 290 static ssize_t tagging_store(struct device *d, struct device_attribute *attr, 291 const char *buf, size_t count) 292 { 293 const struct dsa_device_ops *new_tag_ops, *old_tag_ops; 294 const char *end = strchrnul(buf, '\n'), *name; 295 struct net_device *dev = to_net_dev(d); 296 struct dsa_port *cpu_dp = dev->dsa_ptr; 297 size_t len = end - buf; 298 int err; 299 300 /* Empty string passed */ 301 if (!len) 302 return -ENOPROTOOPT; 303 304 name = kstrndup(buf, len, GFP_KERNEL); 305 if (!name) 306 return -ENOMEM; 307 308 old_tag_ops = cpu_dp->tag_ops; 309 new_tag_ops = dsa_tag_driver_get_by_name(name); 310 kfree(name); 311 /* Bad tagger name? */ 312 if (IS_ERR(new_tag_ops)) 313 return PTR_ERR(new_tag_ops); 314 315 if (new_tag_ops == old_tag_ops) 316 /* Drop the temporarily held duplicate reference, since 317 * the DSA switch tree uses this tagger. 318 */ 319 goto out; 320 321 err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, new_tag_ops, 322 old_tag_ops); 323 if (err) { 324 /* On failure the old tagger is restored, so we don't need the 325 * driver for the new one. 326 */ 327 dsa_tag_driver_put(new_tag_ops); 328 return err; 329 } 330 331 /* On success we no longer need the module for the old tagging protocol 332 */ 333 out: 334 dsa_tag_driver_put(old_tag_ops); 335 return count; 336 } 337 static DEVICE_ATTR_RW(tagging); 338 339 static struct attribute *dsa_user_attrs[] = { 340 &dev_attr_tagging.attr, 341 NULL 342 }; 343 344 static const struct attribute_group dsa_group = { 345 .name = "dsa", 346 .attrs = dsa_user_attrs, 347 }; 348 349 static void dsa_conduit_reset_mtu(struct net_device *dev) 350 { 351 int err; 352 353 err = dev_set_mtu(dev, ETH_DATA_LEN); 354 if (err) 355 netdev_dbg(dev, 356 "Unable to reset MTU to exclude DSA overheads\n"); 357 } 358 359 int dsa_conduit_setup(struct net_device *dev, struct dsa_port *cpu_dp) 360 { 361 const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops; 362 struct dsa_switch *ds = cpu_dp->ds; 363 struct device_link *consumer_link; 364 int mtu, ret; 365 366 mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops); 367 368 /* The DSA conduit must use SET_NETDEV_DEV for this to work. */ 369 if (!netif_is_lag_master(dev)) { 370 consumer_link = device_link_add(ds->dev, dev->dev.parent, 371 DL_FLAG_AUTOREMOVE_CONSUMER); 372 if (!consumer_link) 373 netdev_err(dev, 374 "Failed to create a device link to DSA switch %s\n", 375 dev_name(ds->dev)); 376 } 377 378 /* The switch driver may not implement ->port_change_mtu(), case in 379 * which dsa_user_change_mtu() will not update the conduit MTU either, 380 * so we need to do that here. 381 */ 382 ret = dev_set_mtu(dev, mtu); 383 if (ret) 384 netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n", 385 ret, mtu); 386 387 /* If we use a tagging format that doesn't have an ethertype 388 * field, make sure that all packets from this point on get 389 * sent to the tag format's receive function. 390 */ 391 wmb(); 392 393 dev->dsa_ptr = cpu_dp; 394 395 dsa_conduit_set_promiscuity(dev, 1); 396 397 ret = dsa_conduit_ethtool_setup(dev); 398 if (ret) 399 goto out_err_reset_promisc; 400 401 ret = sysfs_create_group(&dev->dev.kobj, &dsa_group); 402 if (ret) 403 goto out_err_ethtool_teardown; 404 405 return ret; 406 407 out_err_ethtool_teardown: 408 dsa_conduit_ethtool_teardown(dev); 409 out_err_reset_promisc: 410 dsa_conduit_set_promiscuity(dev, -1); 411 return ret; 412 } 413 414 void dsa_conduit_teardown(struct net_device *dev) 415 { 416 sysfs_remove_group(&dev->dev.kobj, &dsa_group); 417 dsa_conduit_ethtool_teardown(dev); 418 dsa_conduit_reset_mtu(dev); 419 dsa_conduit_set_promiscuity(dev, -1); 420 421 dev->dsa_ptr = NULL; 422 423 /* If we used a tagging format that doesn't have an ethertype 424 * field, make sure that all packets from this point get sent 425 * without the tag and go through the regular receive path. 426 */ 427 wmb(); 428 } 429 430 int dsa_conduit_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp, 431 struct netdev_lag_upper_info *uinfo, 432 struct netlink_ext_ack *extack) 433 { 434 bool conduit_setup = false; 435 int err; 436 437 if (!netdev_uses_dsa(lag_dev)) { 438 err = dsa_conduit_setup(lag_dev, cpu_dp); 439 if (err) 440 return err; 441 442 conduit_setup = true; 443 } 444 445 err = dsa_port_lag_join(cpu_dp, lag_dev, uinfo, extack); 446 if (err) { 447 NL_SET_ERR_MSG_WEAK_MOD(extack, "CPU port failed to join LAG"); 448 goto out_conduit_teardown; 449 } 450 451 return 0; 452 453 out_conduit_teardown: 454 if (conduit_setup) 455 dsa_conduit_teardown(lag_dev); 456 return err; 457 } 458 459 /* Tear down a conduit if there isn't any other user port on it, 460 * optionally also destroying LAG information. 461 */ 462 void dsa_conduit_lag_teardown(struct net_device *lag_dev, 463 struct dsa_port *cpu_dp) 464 { 465 struct net_device *upper; 466 struct list_head *iter; 467 468 dsa_port_lag_leave(cpu_dp, lag_dev); 469 470 netdev_for_each_upper_dev_rcu(lag_dev, upper, iter) 471 if (dsa_user_dev_check(upper)) 472 return; 473 474 dsa_conduit_teardown(lag_dev); 475 } 476