LXR linux/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
  11static 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
  40static 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
  75static 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
  94static 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
 120static 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
 142static 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
 190static 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
 219static const struct dsa_netdevice_ops dsa_netdev_ops = {
 220        .ndo_eth_ioctl = dsa_master_ioctl,
 221};
 222
 223static 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
 249static 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
 257static 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
 263static 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
 275static 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
 285static 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         */
 317out:
 318        dsa_tag_driver_put(old_tag_ops);
 319        return count;
 320}
 321static DEVICE_ATTR_RW(tagging);
 322
 323static struct attribute *dsa_slave_attrs[] = {
 324        &dev_attr_tagging.attr,
 325        NULL
 326};
 327
 328static const struct attribute_group dsa_group = {
 329        .name   = "dsa",
 330        .attrs  = dsa_slave_attrs,
 331};
 332
 333static 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
 345static struct lock_class_key dsa_master_addr_list_lock_key;
 346
 347int 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
 395out_err_ndo_teardown:
 396        dsa_netdev_ops_set(dev, NULL);
 397        dsa_master_ethtool_teardown(dev);
 398out_err_reset_promisc:
 399        dsa_master_set_promiscuity(dev, -1);
 400        return ret;
 401}
 402
 403void 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}
 419