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_ethtool_setup(struct net_device *dev)
 201 {
 202         struct dsa_port *cpu_dp = dev->dsa_ptr;
 203         struct dsa_switch *ds = cpu_dp->ds;
 204         struct ethtool_ops *ops;
 205
 206         ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 207         if (!ops)
 208                 return -ENOMEM;
 209
 210         cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
 211         if (cpu_dp->orig_ethtool_ops)
 212                 memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 213
 214         ops->get_regs_len = dsa_master_get_regs_len;
 215         ops->get_regs = dsa_master_get_regs;
 216         ops->get_sset_count = dsa_master_get_sset_count;
 217         ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
 218         ops->get_strings = dsa_master_get_strings;
 219         ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
 220
 221         dev->ethtool_ops = ops;
 222
 223         return 0;
 224 }
 225
 226 static void dsa_master_ethtool_teardown(struct net_device *dev)
 227 {
 228         struct dsa_port *cpu_dp = dev->dsa_ptr;
 229
 230         dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 231         cpu_dp->orig_ethtool_ops = NULL;
 232 }
 233
 234 static int dsa_master_ndo_setup(struct net_device *dev)
 235 {
 236         struct dsa_port *cpu_dp = dev->dsa_ptr;
 237         struct dsa_switch *ds = cpu_dp->ds;
 238         struct net_device_ops *ops;
 239
 240         if (dev->netdev_ops->ndo_get_phys_port_name)
 241                 return 0;
 242
 243         ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 244         if (!ops)
 245                 return -ENOMEM;
 246
 247         cpu_dp->orig_ndo_ops = dev->netdev_ops;
 248         if (cpu_dp->orig_ndo_ops)
 249                 memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
 250
 251         ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
 252
 253         dev->netdev_ops  = ops;
 254
 255         return 0;
 256 }
 257
 258 static void dsa_master_ndo_teardown(struct net_device *dev)
 259 {
 260         struct dsa_port *cpu_dp = dev->dsa_ptr;
 261
 262         dev->netdev_ops = cpu_dp->orig_ndo_ops;
 263         cpu_dp->orig_ndo_ops = NULL;
 264 }
 265
 266 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 267                             char *buf)
 268 {
 269         struct net_device *dev = to_net_dev(d);
 270         struct dsa_port *cpu_dp = dev->dsa_ptr;
 271
 272         return sprintf(buf, "%s\n",
 273                        dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 274 }
 275 static DEVICE_ATTR_RO(tagging);
 276
 277 static struct attribute *dsa_slave_attrs[] = {
 278         &dev_attr_tagging.attr,
 279         NULL
 280 };
 281
 282 static const struct attribute_group dsa_group = {
 283         .name   = "dsa",
 284         .attrs  = dsa_slave_attrs,
 285 };
 286
 287 static void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
 288 {
 289         unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
 290         int err;
 291
 292         rtnl_lock();
 293         if (mtu <= dev->max_mtu) {
 294                 err = dev_set_mtu(dev, mtu);
 295                 if (err)
 296                         netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
 297         }
 298         rtnl_unlock();
 299 }
 300
 301 static void dsa_master_reset_mtu(struct net_device *dev)
 302 {
 303         int err;
 304
 305         rtnl_lock();
 306         err = dev_set_mtu(dev, ETH_DATA_LEN);
 307         if (err)
 308                 netdev_dbg(dev,
 309                            "Unable to reset MTU to exclude DSA overheads\n");
 310         rtnl_unlock();
 311 }
 312
 313 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 314 {
 315         int ret;
 316
 317         dsa_master_set_mtu(dev,  cpu_dp);
 318
 319         /* If we use a tagging format that doesn't have an ethertype
 320          * field, make sure that all packets from this point on get
 321          * sent to the tag format's receive function.
 322          */
 323         wmb();
 324
 325         dev->dsa_ptr = cpu_dp;
 326         ret = dsa_master_ethtool_setup(dev);
 327         if (ret)
 328                 return ret;
 329
 330         ret = dsa_master_ndo_setup(dev);
 331         if (ret)
 332                 goto out_err_ethtool_teardown;
 333
 334         ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
 335         if (ret)
 336                 goto out_err_ndo_teardown;
 337
 338         return ret;
 339
 340 out_err_ndo_teardown:
 341         dsa_master_ndo_teardown(dev);
 342 out_err_ethtool_teardown:
 343         dsa_master_ethtool_teardown(dev);
 344         return ret;
 345 }
 346
 347 void dsa_master_teardown(struct net_device *dev)
 348 {
 349         sysfs_remove_group(&dev->dev.kobj, &dsa_group);
 350         dsa_master_ndo_teardown(dev);
 351         dsa_master_ethtool_teardown(dev);
 352         dsa_master_reset_mtu(dev);
 353
 354         dev->dsa_ptr = NULL;
 355
 356         /* If we used a tagging format that doesn't have an ethertype
 357          * field, make sure that all packets from this point get sent
 358          * without the tag and go through the regular receive path.
 359          */
 360         wmb();
 361 }