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;
 151        unsigned int i;
 152        uint8_t pfx[4];
 153        uint8_t *ndata;
 154
 155        snprintf(pfx, sizeof(pfx), "p%.2d", port);
 156        /* We do not want to be NULL-terminated, since this is a prefix */
 157        pfx[sizeof(pfx) - 1] = '_';
 158
 159        if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
 160            !ops->get_ethtool_phy_stats) {
 161                mcount = phy_ethtool_get_sset_count(dev->phydev);
 162                if (mcount < 0)
 163                        mcount = 0;
 164                else
 165                        phy_ethtool_get_strings(dev->phydev, data);
 166        } else if (ops->get_sset_count && ops->get_strings) {
 167                mcount = ops->get_sset_count(dev, stringset);
 168                if (mcount < 0)
 169                        mcount = 0;
 170                ops->get_strings(dev, stringset, data);
 171        }
 172
 173        if (ds->ops->get_strings) {
 174                ndata = data + mcount * len;
 175                /* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
 176                 * the output after to prepend our CPU port prefix we
 177                 * constructed earlier
 178                 */
 179                ds->ops->get_strings(ds, port, stringset, ndata);
 180                count = ds->ops->get_sset_count(ds, port, stringset);
 181                for (i = 0; i < count; i++) {
 182                        memmove(ndata + (i * len + sizeof(pfx)),
 183                                ndata + i * len, len - sizeof(pfx));
 184                        memcpy(ndata + i * len, pfx, sizeof(pfx));
 185                }
 186        }
 187}
 188
 189static int dsa_master_get_phys_port_name(struct net_device *dev,
 190                                         char *name, size_t len)
 191{
 192        struct dsa_port *cpu_dp = dev->dsa_ptr;
 193
 194        if (snprintf(name, len, "p%d", cpu_dp->index) >= len)
 195                return -EINVAL;
 196
 197        return 0;
 198}
 199
 200static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 201{
 202        struct dsa_port *cpu_dp = dev->dsa_ptr;
 203        struct dsa_switch *ds = cpu_dp->ds;
 204        struct dsa_switch_tree *dst;
 205        int err = -EOPNOTSUPP;
 206        struct dsa_port *dp;
 207
 208        dst = ds->dst;
 209
 210        switch (cmd) {
 211        case SIOCGHWTSTAMP:
 212        case SIOCSHWTSTAMP:
 213                /* Deny PTP operations on master if there is at least one
 214                 * switch in the tree that is PTP capable.
 215                 */
 216                list_for_each_entry(dp, &dst->ports, list)
 217                        if (dp->ds->ops->port_hwtstamp_get ||
 218                            dp->ds->ops->port_hwtstamp_set)
 219                                return -EBUSY;
 220                break;
 221        }
 222
 223        if (cpu_dp->orig_ndo_ops && cpu_dp->orig_ndo_ops->ndo_do_ioctl)
 224                err = cpu_dp->orig_ndo_ops->ndo_do_ioctl(dev, ifr, cmd);
 225
 226        return err;
 227}
 228
 229static int dsa_master_ethtool_setup(struct net_device *dev)
 230{
 231        struct dsa_port *cpu_dp = dev->dsa_ptr;
 232        struct dsa_switch *ds = cpu_dp->ds;
 233        struct ethtool_ops *ops;
 234
 235        ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 236        if (!ops)
 237                return -ENOMEM;
 238
 239        cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
 240        if (cpu_dp->orig_ethtool_ops)
 241                memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 242
 243        ops->get_regs_len = dsa_master_get_regs_len;
 244        ops->get_regs = dsa_master_get_regs;
 245        ops->get_sset_count = dsa_master_get_sset_count;
 246        ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
 247        ops->get_strings = dsa_master_get_strings;
 248        ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
 249
 250        dev->ethtool_ops = ops;
 251
 252        return 0;
 253}
 254
 255static void dsa_master_ethtool_teardown(struct net_device *dev)
 256{
 257        struct dsa_port *cpu_dp = dev->dsa_ptr;
 258
 259        dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 260        cpu_dp->orig_ethtool_ops = NULL;
 261}
 262
 263static int dsa_master_ndo_setup(struct net_device *dev)
 264{
 265        struct dsa_port *cpu_dp = dev->dsa_ptr;
 266        struct dsa_switch *ds = cpu_dp->ds;
 267        struct net_device_ops *ops;
 268
 269        if (dev->netdev_ops->ndo_get_phys_port_name)
 270                return 0;
 271
 272        ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 273        if (!ops)
 274                return -ENOMEM;
 275
 276        cpu_dp->orig_ndo_ops = dev->netdev_ops;
 277        if (cpu_dp->orig_ndo_ops)
 278                memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
 279
 280        ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
 281        ops->ndo_do_ioctl = dsa_master_ioctl;
 282
 283        dev->netdev_ops  = ops;
 284
 285        return 0;
 286}
 287
 288static void dsa_master_ndo_teardown(struct net_device *dev)
 289{
 290        struct dsa_port *cpu_dp = dev->dsa_ptr;
 291
 292        if (cpu_dp->orig_ndo_ops)
 293                dev->netdev_ops = cpu_dp->orig_ndo_ops;
 294        cpu_dp->orig_ndo_ops = NULL;
 295}
 296
 297static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 298                            char *buf)
 299{
 300        struct net_device *dev = to_net_dev(d);
 301        struct dsa_port *cpu_dp = dev->dsa_ptr;
 302
 303        return sprintf(buf, "%s\n",
 304                       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 305}
 306static DEVICE_ATTR_RO(tagging);
 307
 308static struct attribute *dsa_slave_attrs[] = {
 309        &dev_attr_tagging.attr,
 310        NULL
 311};
 312
 313static const struct attribute_group dsa_group = {
 314        .name   = "dsa",
 315        .attrs  = dsa_slave_attrs,
 316};
 317
 318static void dsa_master_reset_mtu(struct net_device *dev)
 319{
 320        int err;
 321
 322        rtnl_lock();
 323        err = dev_set_mtu(dev, ETH_DATA_LEN);
 324        if (err)
 325                netdev_dbg(dev,
 326                           "Unable to reset MTU to exclude DSA overheads\n");
 327        rtnl_unlock();
 328}
 329
 330static struct lock_class_key dsa_master_addr_list_lock_key;
 331
 332int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 333{
 334        int ret;
 335
 336        rtnl_lock();
 337        ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
 338        rtnl_unlock();
 339        if (ret)
 340                netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
 341                            ret);
 342
 343        /* If we use a tagging format that doesn't have an ethertype
 344         * field, make sure that all packets from this point on get
 345         * sent to the tag format's receive function.
 346         */
 347        wmb();
 348
 349        dev->dsa_ptr = cpu_dp;
 350        lockdep_set_class(&dev->addr_list_lock,
 351                          &dsa_master_addr_list_lock_key);
 352        ret = dsa_master_ethtool_setup(dev);
 353        if (ret)
 354                return ret;
 355
 356        ret = dsa_master_ndo_setup(dev);
 357        if (ret)
 358                goto out_err_ethtool_teardown;
 359
 360        ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
 361        if (ret)
 362                goto out_err_ndo_teardown;
 363
 364        return ret;
 365
 366out_err_ndo_teardown:
 367        dsa_master_ndo_teardown(dev);
 368out_err_ethtool_teardown:
 369        dsa_master_ethtool_teardown(dev);
 370        return ret;
 371}
 372
 373void dsa_master_teardown(struct net_device *dev)
 374{
 375        sysfs_remove_group(&dev->dev.kobj, &dsa_group);
 376        dsa_master_ndo_teardown(dev);
 377        dsa_master_ethtool_teardown(dev);
 378        dsa_master_reset_mtu(dev);
 379
 380        dev->dsa_ptr = NULL;
 381
 382        /* If we used a tagging format that doesn't have an ethertype
 383         * field, make sure that all packets from this point get sent
 384         * without the tag and go through the regular receive path.
 385         */
 386        wmb();
 387}
 388