net/dsa/master.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Handling of a master 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 "dsa_priv.h"
  10
  11 static int dsa_master_get_regs_len(struct net_device *dev)
  12 {
  13         struct dsa_port *cpu_dp = dev->dsa_ptr;
  14         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  15         struct dsa_switch *ds = cpu_dp->ds;
  16         int port = cpu_dp->index;
  17         int ret = 0;
  18         int len;
  19
  20         if (ops->get_regs_len) {
  21                 len = ops->get_regs_len(dev);
  22                 if (len < 0)
  23                         return len;
  24                 ret += len;
  25         }
  26
  27         ret += sizeof(struct ethtool_drvinfo);
  28         ret += sizeof(struct ethtool_regs);
  29
  30         if (ds->ops->get_regs_len) {
  31                 len = ds->ops->get_regs_len(ds, port);
  32                 if (len < 0)
  33                         return len;
  34                 ret += len;
  35         }
  36
  37         return ret;
  38 }
  39
  40 static void dsa_master_get_regs(struct net_device *dev,
  41                                 struct ethtool_regs *regs, void *data)
  42 {
  43         struct dsa_port *cpu_dp = dev->dsa_ptr;
  44         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  45         struct dsa_switch *ds = cpu_dp->ds;
  46         struct ethtool_drvinfo *cpu_info;
  47         struct ethtool_regs *cpu_regs;
  48         int port = cpu_dp->index;
  49         int len;
  50
  51         if (ops->get_regs_len && ops->get_regs) {
  52                 len = ops->get_regs_len(dev);
  53                 if (len < 0)
  54                         return;
  55                 regs->len = len;
  56                 ops->get_regs(dev, regs, data);
  57                 data += regs->len;
  58         }
  59
  60         cpu_info = (struct ethtool_drvinfo *)data;
  61         strlcpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
  62         data += sizeof(*cpu_info);
  63         cpu_regs = (struct ethtool_regs *)data;
  64         data += sizeof(*cpu_regs);
  65
  66         if (ds->ops->get_regs_len && ds->ops->get_regs) {
  67                 len = ds->ops->get_regs_len(ds, port);
  68                 if (len < 0)
  69                         return;
  70                 cpu_regs->len = len;
  71                 ds->ops->get_regs(ds, port, cpu_regs, data);
  72         }
  73 }
  74
  75 static void dsa_master_get_ethtool_stats(struct net_device *dev,
  76                                          struct ethtool_stats *stats,
  77                                          uint64_t *data)
  78 {
  79         struct dsa_port *cpu_dp = dev->dsa_ptr;
  80         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  81         struct dsa_switch *ds = cpu_dp->ds;
  82         int port = cpu_dp->index;
  83         int count = 0;
  84
  85         if (ops->get_sset_count && ops->get_ethtool_stats) {
  86                 count = ops->get_sset_count(dev, ETH_SS_STATS);
  87                 ops->get_ethtool_stats(dev, stats, data);
  88         }
  89
  90         if (ds->ops->get_ethtool_stats)
  91                 ds->ops->get_ethtool_stats(ds, port, data + count);
  92 }
  93
  94 static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
  95                                              struct ethtool_stats *stats,
  96                                              uint64_t *data)
  97 {
  98         struct dsa_port *cpu_dp = dev->dsa_ptr;
  99         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 100         struct dsa_switch *ds = cpu_dp->ds;
 101         int port = cpu_dp->index;
 102         int count = 0;
 103
 104         if (dev->phydev && !ops->get_ethtool_phy_stats) {
 105                 count = phy_ethtool_get_sset_count(dev->phydev);
 106                 if (count >= 0)
 107                         phy_ethtool_get_stats(dev->phydev, stats, data);
 108         } else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
 109                 count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
 110                 ops->get_ethtool_phy_stats(dev, stats, data);
 111         }
 112
 113         if (count < 0)
 114                 count = 0;
 115
 116         if (ds->ops->get_ethtool_phy_stats)
 117                 ds->ops->get_ethtool_phy_stats(ds, port, data + count);
 118 }
 119
 120 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
 121 {
 122         struct dsa_port *cpu_dp = dev->dsa_ptr;
 123         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 124         struct dsa_switch *ds = cpu_dp->ds;
 125         int count = 0;
 126
 127         if (sset == ETH_SS_PHY_STATS && dev->phydev &&
 128             !ops->get_ethtool_phy_stats)
 129                 count = phy_ethtool_get_sset_count(dev->phydev);
 130         else if (ops->get_sset_count)
 131                 count = ops->get_sset_count(dev, sset);
 132
 133         if (count < 0)
 134                 count = 0;
 135
 136         if (ds->ops->get_sset_count)
 137                 count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
 138
 139         return count;
 140 }
 141
 142 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 143                                    uint8_t *data)
 144 {
 145         struct dsa_port *cpu_dp = dev->dsa_ptr;
 146         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 147         struct dsa_switch *ds = cpu_dp->ds;
 148         int port = cpu_dp->index;
 149         int len = ETH_GSTRING_LEN;
 150         int mcount = 0, count, i;
 151         uint8_t pfx[4];
 152         uint8_t *ndata;
 153
 154         snprintf(pfx, sizeof(pfx), "p%.2d", port);
 155         /* We do not want to be NULL-terminated, since this is a prefix */
 156         pfx[sizeof(pfx) - 1] = '_';
 157
 158         if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
 159             !ops->get_ethtool_phy_stats) {
 160                 mcount = phy_ethtool_get_sset_count(dev->phydev);
 161                 if (mcount < 0)
 162                         mcount = 0;
 163                 else
 164                         phy_ethtool_get_strings(dev->phydev, data);
 165         } else if (ops->get_sset_count && ops->get_strings) {
 166                 mcount = ops->get_sset_count(dev, stringset);
 167                 if (mcount < 0)
 168                         mcount = 0;
 169                 ops->get_strings(dev, stringset, data);
 170         }
 171
 172         if (ds->ops->get_strings) {
 173                 ndata = data + mcount * len;
 174                 /* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
 175                  * the output after to prepend our CPU port prefix we
 176                  * constructed earlier
 177                  */
 178                 ds->ops->get_strings(ds, port, stringset, ndata);
 179                 count = ds->ops->get_sset_count(ds, port, stringset);
 180                 if (count < 0)
 181                         return;
 182                 for (i = 0; i < count; i++) {
 183                         memmove(ndata + (i * len + sizeof(pfx)),
 184                                 ndata + i * len, len - sizeof(pfx));
 185                         memcpy(ndata + i * len, pfx, sizeof(pfx));
 186                 }
 187         }
 188 }
 189
 190 static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 191 {
 192         struct dsa_port *cpu_dp = dev->dsa_ptr;
 193         struct dsa_switch *ds = cpu_dp->ds;
 194         struct dsa_switch_tree *dst;
 195         int err = -EOPNOTSUPP;
 196         struct dsa_port *dp;
 197
 198         dst = ds->dst;
 199
 200         switch (cmd) {
 201         case SIOCGHWTSTAMP:
 202         case SIOCSHWTSTAMP:
 203                 /* Deny PTP operations on master if there is at least one
 204                  * switch in the tree that is PTP capable.
 205                  */
 206                 list_for_each_entry(dp, &dst->ports, list)
 207                         if (dp->ds->ops->port_hwtstamp_get ||
 208                             dp->ds->ops->port_hwtstamp_set)
 209                                 return -EBUSY;
 210                 break;
 211         }
 212
 213         if (dev->netdev_ops->ndo_eth_ioctl)
 214                 err = dev->netdev_ops->ndo_eth_ioctl(dev, ifr, cmd);
 215
 216         return err;
 217 }
 218
 219 static const struct dsa_netdevice_ops dsa_netdev_ops = {
 220         .ndo_eth_ioctl = dsa_master_ioctl,
 221 };
 222
 223 static int dsa_master_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         ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 230         if (!ops)
 231                 return -ENOMEM;
 232
 233         cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
 234         if (cpu_dp->orig_ethtool_ops)
 235                 memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 236
 237         ops->get_regs_len = dsa_master_get_regs_len;
 238         ops->get_regs = dsa_master_get_regs;
 239         ops->get_sset_count = dsa_master_get_sset_count;
 240         ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
 241         ops->get_strings = dsa_master_get_strings;
 242         ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
 243
 244         dev->ethtool_ops = ops;
 245
 246         return 0;
 247 }
 248
 249 static void dsa_master_ethtool_teardown(struct net_device *dev)
 250 {
 251         struct dsa_port *cpu_dp = dev->dsa_ptr;
 252
 253         dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 254         cpu_dp->orig_ethtool_ops = NULL;
 255 }
 256
 257 static void dsa_netdev_ops_set(struct net_device *dev,
 258                                const struct dsa_netdevice_ops *ops)
 259 {
 260         dev->dsa_ptr->netdev_ops = ops;
 261 }
 262
 263 static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
 264 {
 265         const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
 266
 267         if (!ops->promisc_on_master)
 268                 return;
 269
 270         rtnl_lock();
 271         dev_set_promiscuity(dev, inc);
 272         rtnl_unlock();
 273 }
 274
 275 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 276                             char *buf)
 277 {
 278         struct net_device *dev = to_net_dev(d);
 279         struct dsa_port *cpu_dp = dev->dsa_ptr;
 280
 281         return sprintf(buf, "%s\n",
 282                        dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 283 }
 284
 285 static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
 286                              const char *buf, size_t count)
 287 {
 288         const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
 289         struct net_device *dev = to_net_dev(d);
 290         struct dsa_port *cpu_dp = dev->dsa_ptr;
 291         int err;
 292
 293         old_tag_ops = cpu_dp->tag_ops;
 294         new_tag_ops = dsa_find_tagger_by_name(buf);
 295         /* Bad tagger name, or module is not loaded? */
 296         if (IS_ERR(new_tag_ops))
 297                 return PTR_ERR(new_tag_ops);
 298
 299         if (new_tag_ops == old_tag_ops)
 300                 /* Drop the temporarily held duplicate reference, since
 301                  * the DSA switch tree uses this tagger.
 302                  */
 303                 goto out;
 304
 305         err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, dev, new_tag_ops,
 306                                         old_tag_ops);
 307         if (err) {
 308                 /* On failure the old tagger is restored, so we don't need the
 309                  * driver for the new one.
 310                  */
 311                 dsa_tag_driver_put(new_tag_ops);
 312                 return err;
 313         }
 314
 315         /* On success we no longer need the module for the old tagging protocol
 316          */
 317 out:
 318         dsa_tag_driver_put(old_tag_ops);
 319         return count;
 320 }
 321 static DEVICE_ATTR_RW(tagging);
 322
 323 static struct attribute *dsa_slave_attrs[] = {
 324         &dev_attr_tagging.attr,
 325         NULL
 326 };
 327
 328 static const struct attribute_group dsa_group = {
 329         .name   = "dsa",
 330         .attrs  = dsa_slave_attrs,
 331 };
 332
 333 static void dsa_master_reset_mtu(struct net_device *dev)
 334 {
 335         int err;
 336
 337         rtnl_lock();
 338         err = dev_set_mtu(dev, ETH_DATA_LEN);
 339         if (err)
 340                 netdev_dbg(dev,
 341                            "Unable to reset MTU to exclude DSA overheads\n");
 342         rtnl_unlock();
 343 }
 344
 345 static struct lock_class_key dsa_master_addr_list_lock_key;
 346
 347 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 348 {
 349         const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
 350         struct dsa_switch *ds = cpu_dp->ds;
 351         struct device_link *consumer_link;
 352         int mtu, ret;
 353
 354         mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
 355
 356         /* The DSA master must use SET_NETDEV_DEV for this to work. */
 357         consumer_link = device_link_add(ds->dev, dev->dev.parent,
 358                                         DL_FLAG_AUTOREMOVE_CONSUMER);
 359         if (!consumer_link)
 360                 netdev_err(dev,
 361                            "Failed to create a device link to DSA switch %s\n",
 362                            dev_name(ds->dev));
 363
 364         rtnl_lock();
 365         ret = dev_set_mtu(dev, mtu);
 366         rtnl_unlock();
 367         if (ret)
 368                 netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
 369                             ret, mtu);
 370
 371         /* If we use a tagging format that doesn't have an ethertype
 372          * field, make sure that all packets from this point on get
 373          * sent to the tag format's receive function.
 374          */
 375         wmb();
 376
 377         dev->dsa_ptr = cpu_dp;
 378         lockdep_set_class(&dev->addr_list_lock,
 379                           &dsa_master_addr_list_lock_key);
 380
 381         dsa_master_set_promiscuity(dev, 1);
 382
 383         ret = dsa_master_ethtool_setup(dev);
 384         if (ret)
 385                 goto out_err_reset_promisc;
 386
 387         dsa_netdev_ops_set(dev, &dsa_netdev_ops);
 388
 389         ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
 390         if (ret)
 391                 goto out_err_ndo_teardown;
 392
 393         return ret;
 394
 395 out_err_ndo_teardown:
 396         dsa_netdev_ops_set(dev, NULL);
 397         dsa_master_ethtool_teardown(dev);
 398 out_err_reset_promisc:
 399         dsa_master_set_promiscuity(dev, -1);
 400         return ret;
 401 }
 402
 403 void dsa_master_teardown(struct net_device *dev)
 404 {
 405         sysfs_remove_group(&dev->dev.kobj, &dsa_group);
 406         dsa_netdev_ops_set(dev, NULL);
 407         dsa_master_ethtool_teardown(dev);
 408         dsa_master_reset_mtu(dev);
 409         dsa_master_set_promiscuity(dev, -1);
 410
 411         dev->dsa_ptr = NULL;
 412
 413         /* If we used a tagging format that doesn't have an ethertype
 414          * field, make sure that all packets from this point get sent
 415          * without the tag and go through the regular receive path.
 416          */
 417         wmb();
 418 }