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;
 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
 189 static 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
 200 static 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
 229 static 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
 255 static 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
 263 static 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
 288 static 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
 297 static 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 }
 306 static DEVICE_ATTR_RO(tagging);
 307
 308 static struct attribute *dsa_slave_attrs[] = {
 309         &dev_attr_tagging.attr,
 310         NULL
 311 };
 312
 313 static const struct attribute_group dsa_group = {
 314         .name   = "dsa",
 315         .attrs  = dsa_slave_attrs,
 316 };
 317
 318 static 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
 330 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 331 {
 332         int ret;
 333
 334         rtnl_lock();
 335         ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
 336         rtnl_unlock();
 337         if (ret)
 338                 netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
 339                             ret);
 340
 341         /* If we use a tagging format that doesn't have an ethertype
 342          * field, make sure that all packets from this point on get
 343          * sent to the tag format's receive function.
 344          */
 345         wmb();
 346
 347         dev->dsa_ptr = cpu_dp;
 348         ret = dsa_master_ethtool_setup(dev);
 349         if (ret)
 350                 return ret;
 351
 352         ret = dsa_master_ndo_setup(dev);
 353         if (ret)
 354                 goto out_err_ethtool_teardown;
 355
 356         ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
 357         if (ret)
 358                 goto out_err_ndo_teardown;
 359
 360         return ret;
 361
 362 out_err_ndo_teardown:
 363         dsa_master_ndo_teardown(dev);
 364 out_err_ethtool_teardown:
 365         dsa_master_ethtool_teardown(dev);
 366         return ret;
 367 }
 368
 369 void dsa_master_teardown(struct net_device *dev)
 370 {
 371         sysfs_remove_group(&dev->dev.kobj, &dsa_group);
 372         dsa_master_ndo_teardown(dev);
 373         dsa_master_ethtool_teardown(dev);
 374         dsa_master_reset_mtu(dev);
 375
 376         dev->dsa_ptr = NULL;
 377
 378         /* If we used a tagging format that doesn't have an ethertype
 379          * field, make sure that all packets from this point get sent
 380          * without the tag and go through the regular receive path.
 381          */
 382         wmb();
 383 }