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_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 190{
 191        struct dsa_port *cpu_dp = dev->dsa_ptr;
 192        struct dsa_switch *ds = cpu_dp->ds;
 193        struct dsa_switch_tree *dst;
 194        int err = -EOPNOTSUPP;
 195        struct dsa_port *dp;
 196
 197        dst = ds->dst;
 198
 199        switch (cmd) {
 200        case SIOCGHWTSTAMP:
 201        case SIOCSHWTSTAMP:
 202                /* Deny PTP operations on master if there is at least one
 203                 * switch in the tree that is PTP capable.
 204                 */
 205                list_for_each_entry(dp, &dst->ports, list)
 206                        if (dp->ds->ops->port_hwtstamp_get ||
 207                            dp->ds->ops->port_hwtstamp_set)
 208                                return -EBUSY;
 209                break;
 210        }
 211
 212        if (dev->netdev_ops->ndo_do_ioctl)
 213                err = dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
 214
 215        return err;
 216}
 217
 218static const struct dsa_netdevice_ops dsa_netdev_ops = {
 219        .ndo_do_ioctl = dsa_master_ioctl,
 220};
 221
 222static int dsa_master_ethtool_setup(struct net_device *dev)
 223{
 224        struct dsa_port *cpu_dp = dev->dsa_ptr;
 225        struct dsa_switch *ds = cpu_dp->ds;
 226        struct ethtool_ops *ops;
 227
 228        ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 229        if (!ops)
 230                return -ENOMEM;
 231
 232        cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
 233        if (cpu_dp->orig_ethtool_ops)
 234                memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 235
 236        ops->get_regs_len = dsa_master_get_regs_len;
 237        ops->get_regs = dsa_master_get_regs;
 238        ops->get_sset_count = dsa_master_get_sset_count;
 239        ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
 240        ops->get_strings = dsa_master_get_strings;
 241        ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
 242
 243        dev->ethtool_ops = ops;
 244
 245        return 0;
 246}
 247
 248static void dsa_master_ethtool_teardown(struct net_device *dev)
 249{
 250        struct dsa_port *cpu_dp = dev->dsa_ptr;
 251
 252        dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 253        cpu_dp->orig_ethtool_ops = NULL;
 254}
 255
 256static void dsa_netdev_ops_set(struct net_device *dev,
 257                               const struct dsa_netdevice_ops *ops)
 258{
 259        dev->dsa_ptr->netdev_ops = ops;
 260}
 261
 262static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 263                            char *buf)
 264{
 265        struct net_device *dev = to_net_dev(d);
 266        struct dsa_port *cpu_dp = dev->dsa_ptr;
 267
 268        return sprintf(buf, "%s\n",
 269                       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 270}
 271static DEVICE_ATTR_RO(tagging);
 272
 273static struct attribute *dsa_slave_attrs[] = {
 274        &dev_attr_tagging.attr,
 275        NULL
 276};
 277
 278static const struct attribute_group dsa_group = {
 279        .name   = "dsa",
 280        .attrs  = dsa_slave_attrs,
 281};
 282
 283static void dsa_master_reset_mtu(struct net_device *dev)
 284{
 285        int err;
 286
 287        rtnl_lock();
 288        err = dev_set_mtu(dev, ETH_DATA_LEN);
 289        if (err)
 290                netdev_dbg(dev,
 291                           "Unable to reset MTU to exclude DSA overheads\n");
 292        rtnl_unlock();
 293}
 294
 295static struct lock_class_key dsa_master_addr_list_lock_key;
 296
 297int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 298{
 299        int ret;
 300
 301        rtnl_lock();
 302        ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
 303        rtnl_unlock();
 304        if (ret)
 305                netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
 306                            ret);
 307
 308        /* If we use a tagging format that doesn't have an ethertype
 309         * field, make sure that all packets from this point on get
 310         * sent to the tag format's receive function.
 311         */
 312        wmb();
 313
 314        dev->dsa_ptr = cpu_dp;
 315        lockdep_set_class(&dev->addr_list_lock,
 316                          &dsa_master_addr_list_lock_key);
 317        ret = dsa_master_ethtool_setup(dev);
 318        if (ret)
 319                return ret;
 320
 321        dsa_netdev_ops_set(dev, &dsa_netdev_ops);
 322
 323        ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
 324        if (ret)
 325                goto out_err_ndo_teardown;
 326
 327        return ret;
 328
 329out_err_ndo_teardown:
 330        dsa_netdev_ops_set(dev, NULL);
 331        dsa_master_ethtool_teardown(dev);
 332        return ret;
 333}
 334
 335void dsa_master_teardown(struct net_device *dev)
 336{
 337        sysfs_remove_group(&dev->dev.kobj, &dsa_group);
 338        dsa_netdev_ops_set(dev, NULL);
 339        dsa_master_ethtool_teardown(dev);
 340        dsa_master_reset_mtu(dev);
 341
 342        dev->dsa_ptr = NULL;
 343
 344        /* If we used a tagging format that doesn't have an ethertype
 345         * field, make sure that all packets from this point get sent
 346         * without the tag and go through the regular receive path.
 347         */
 348        wmb();
 349}
 350