drivers/net/ntb_netdev.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
   9  *
  10  *   This program is free software; you can redistribute it and/or modify
  11  *   it under the terms of version 2 of the GNU General Public License as
  12  *   published by the Free Software Foundation.
  13  *
  14  *   BSD LICENSE
  15  *
  16  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  17  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
  18  *
  19  *   Redistribution and use in source and binary forms, with or without
  20  *   modification, are permitted provided that the following conditions
  21  *   are met:
  22  *
  23  *     * Redistributions of source code must retain the above copyright
  24  *       notice, this list of conditions and the following disclaimer.
  25  *     * Redistributions in binary form must reproduce the above copy
  26  *       notice, this list of conditions and the following disclaimer in
  27  *       the documentation and/or other materials provided with the
  28  *       distribution.
  29  *     * Neither the name of Intel Corporation nor the names of its
  30  *       contributors may be used to endorse or promote products derived
  31  *       from this software without specific prior written permission.
  32  *
  33  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  34  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  35  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  36  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  37  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  38  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  39  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  40  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  41  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  42  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  43  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  44  *
  45  * PCIe NTB Network Linux driver
  46  *
  47  * Contact Information:
  48  * Jon Mason <jon.mason@intel.com>
  49  */
  50 #include <linux/etherdevice.h>
  51 #include <linux/ethtool.h>
  52 #include <linux/module.h>
  53 #include <linux/pci.h>
  54 #include <linux/ntb.h>
  55 #include <linux/ntb_transport.h>
  56
  57 #define NTB_NETDEV_VER  "0.7"
  58
  59 MODULE_DESCRIPTION(KBUILD_MODNAME);
  60 MODULE_VERSION(NTB_NETDEV_VER);
  61 MODULE_LICENSE("Dual BSD/GPL");
  62 MODULE_AUTHOR("Intel Corporation");
  63
  64 /* Time in usecs for tx resource reaper */
  65 static unsigned int tx_time = 1;
  66
  67 /* Number of descriptors to free before resuming tx */
  68 static unsigned int tx_start = 10;
  69
  70 /* Number of descriptors still available before stop upper layer tx */
  71 static unsigned int tx_stop = 5;
  72
  73 struct ntb_netdev {
  74         struct pci_dev *pdev;
  75         struct net_device *ndev;
  76         struct ntb_transport_qp *qp;
  77         struct timer_list tx_timer;
  78 };
  79
  80 #define NTB_TX_TIMEOUT_MS       1000
  81 #define NTB_RXQ_SIZE            100
  82
  83 static void ntb_netdev_event_handler(void *data, int link_is_up)
  84 {
  85         struct net_device *ndev = data;
  86         struct ntb_netdev *dev = netdev_priv(ndev);
  87
  88         netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up,
  89                    ntb_transport_link_query(dev->qp));
  90
  91         if (link_is_up) {
  92                 if (ntb_transport_link_query(dev->qp))
  93                         netif_carrier_on(ndev);
  94         } else {
  95                 netif_carrier_off(ndev);
  96         }
  97 }
  98
  99 static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
 100                                   void *data, int len)
 101 {
 102         struct net_device *ndev = qp_data;
 103         struct sk_buff *skb;
 104         int rc;
 105
 106         skb = data;
 107         if (!skb)
 108                 return;
 109
 110         netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len);
 111
 112         if (len < 0) {
 113                 ndev->stats.rx_errors++;
 114                 ndev->stats.rx_length_errors++;
 115                 goto enqueue_again;
 116         }
 117
 118         skb_put(skb, len);
 119         skb->protocol = eth_type_trans(skb, ndev);
 120         skb->ip_summed = CHECKSUM_NONE;
 121
 122         if (netif_rx(skb) == NET_RX_DROP) {
 123                 ndev->stats.rx_errors++;
 124                 ndev->stats.rx_dropped++;
 125         } else {
 126                 ndev->stats.rx_packets++;
 127                 ndev->stats.rx_bytes += len;
 128         }
 129
 130         skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
 131         if (!skb) {
 132                 ndev->stats.rx_errors++;
 133                 ndev->stats.rx_frame_errors++;
 134                 return;
 135         }
 136
 137 enqueue_again:
 138         rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
 139         if (rc) {
 140                 dev_kfree_skb(skb);
 141                 ndev->stats.rx_errors++;
 142                 ndev->stats.rx_fifo_errors++;
 143         }
 144 }
 145
 146 static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev,
 147                                       struct ntb_transport_qp *qp, int size)
 148 {
 149         struct ntb_netdev *dev = netdev_priv(netdev);
 150
 151         netif_stop_queue(netdev);
 152         /* Make sure to see the latest value of ntb_transport_tx_free_entry()
 153          * since the queue was last started.
 154          */
 155         smp_mb();
 156
 157         if (likely(ntb_transport_tx_free_entry(qp) < size)) {
 158                 mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time));
 159                 return -EBUSY;
 160         }
 161
 162         netif_start_queue(netdev);
 163         return 0;
 164 }
 165
 166 static int ntb_netdev_maybe_stop_tx(struct net_device *ndev,
 167                                     struct ntb_transport_qp *qp, int size)
 168 {
 169         if (netif_queue_stopped(ndev) ||
 170             (ntb_transport_tx_free_entry(qp) >= size))
 171                 return 0;
 172
 173         return __ntb_netdev_maybe_stop_tx(ndev, qp, size);
 174 }
 175
 176 static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
 177                                   void *data, int len)
 178 {
 179         struct net_device *ndev = qp_data;
 180         struct sk_buff *skb;
 181         struct ntb_netdev *dev = netdev_priv(ndev);
 182
 183         skb = data;
 184         if (!skb || !ndev)
 185                 return;
 186
 187         if (len > 0) {
 188                 ndev->stats.tx_packets++;
 189                 ndev->stats.tx_bytes += skb->len;
 190         } else {
 191                 ndev->stats.tx_errors++;
 192                 ndev->stats.tx_aborted_errors++;
 193         }
 194
 195         dev_kfree_skb(skb);
 196
 197         if (ntb_transport_tx_free_entry(dev->qp) >= tx_start) {
 198                 /* Make sure anybody stopping the queue after this sees the new
 199                  * value of ntb_transport_tx_free_entry()
 200                  */
 201                 smp_mb();
 202                 if (netif_queue_stopped(ndev))
 203                         netif_wake_queue(ndev);
 204         }
 205 }
 206
 207 static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
 208                                          struct net_device *ndev)
 209 {
 210         struct ntb_netdev *dev = netdev_priv(ndev);
 211         int rc;
 212
 213         ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);
 214
 215         rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
 216         if (rc)
 217                 goto err;
 218
 219         /* check for next submit */
 220         ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);
 221
 222         return NETDEV_TX_OK;
 223
 224 err:
 225         ndev->stats.tx_dropped++;
 226         ndev->stats.tx_errors++;
 227         return NETDEV_TX_BUSY;
 228 }
 229
 230 static void ntb_netdev_tx_timer(struct timer_list *t)
 231 {
 232         struct ntb_netdev *dev = from_timer(dev, t, tx_timer);
 233         struct net_device *ndev = dev->ndev;
 234
 235         if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) {
 236                 mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time));
 237         } else {
 238                 /* Make sure anybody stopping the queue after this sees the new
 239                  * value of ntb_transport_tx_free_entry()
 240                  */
 241                 smp_mb();
 242                 if (netif_queue_stopped(ndev))
 243                         netif_wake_queue(ndev);
 244         }
 245 }
 246
 247 static int ntb_netdev_open(struct net_device *ndev)
 248 {
 249         struct ntb_netdev *dev = netdev_priv(ndev);
 250         struct sk_buff *skb;
 251         int rc, i, len;
 252
 253         /* Add some empty rx bufs */
 254         for (i = 0; i < NTB_RXQ_SIZE; i++) {
 255                 skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
 256                 if (!skb) {
 257                         rc = -ENOMEM;
 258                         goto err;
 259                 }
 260
 261                 rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
 262                                               ndev->mtu + ETH_HLEN);
 263                 if (rc) {
 264                         dev_kfree_skb(skb);
 265                         goto err;
 266                 }
 267         }
 268
 269         timer_setup(&dev->tx_timer, ntb_netdev_tx_timer, 0);
 270
 271         netif_carrier_off(ndev);
 272         ntb_transport_link_up(dev->qp);
 273         netif_start_queue(ndev);
 274
 275         return 0;
 276
 277 err:
 278         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 279                 dev_kfree_skb(skb);
 280         return rc;
 281 }
 282
 283 static int ntb_netdev_close(struct net_device *ndev)
 284 {
 285         struct ntb_netdev *dev = netdev_priv(ndev);
 286         struct sk_buff *skb;
 287         int len;
 288
 289         ntb_transport_link_down(dev->qp);
 290
 291         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 292                 dev_kfree_skb(skb);
 293
 294         del_timer_sync(&dev->tx_timer);
 295
 296         return 0;
 297 }
 298
 299 static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu)
 300 {
 301         struct ntb_netdev *dev = netdev_priv(ndev);
 302         struct sk_buff *skb;
 303         int len, rc;
 304
 305         if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN)
 306                 return -EINVAL;
 307
 308         if (!netif_running(ndev)) {
 309                 ndev->mtu = new_mtu;
 310                 return 0;
 311         }
 312
 313         /* Bring down the link and dispose of posted rx entries */
 314         ntb_transport_link_down(dev->qp);
 315
 316         if (ndev->mtu < new_mtu) {
 317                 int i;
 318
 319                 for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++)
 320                         dev_kfree_skb(skb);
 321
 322                 for (; i; i--) {
 323                         skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN);
 324                         if (!skb) {
 325                                 rc = -ENOMEM;
 326                                 goto err;
 327                         }
 328
 329                         rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
 330                                                       new_mtu + ETH_HLEN);
 331                         if (rc) {
 332                                 dev_kfree_skb(skb);
 333                                 goto err;
 334                         }
 335                 }
 336         }
 337
 338         ndev->mtu = new_mtu;
 339
 340         ntb_transport_link_up(dev->qp);
 341
 342         return 0;
 343
 344 err:
 345         ntb_transport_link_down(dev->qp);
 346
 347         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 348                 dev_kfree_skb(skb);
 349
 350         netdev_err(ndev, "Error changing MTU, device inoperable\n");
 351         return rc;
 352 }
 353
 354 static const struct net_device_ops ntb_netdev_ops = {
 355         .ndo_open = ntb_netdev_open,
 356         .ndo_stop = ntb_netdev_close,
 357         .ndo_start_xmit = ntb_netdev_start_xmit,
 358         .ndo_change_mtu = ntb_netdev_change_mtu,
 359         .ndo_set_mac_address = eth_mac_addr,
 360 };
 361
 362 static void ntb_get_drvinfo(struct net_device *ndev,
 363                             struct ethtool_drvinfo *info)
 364 {
 365         struct ntb_netdev *dev = netdev_priv(ndev);
 366
 367         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 368         strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
 369         strlcpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info));
 370 }
 371
 372 static int ntb_get_link_ksettings(struct net_device *dev,
 373                                   struct ethtool_link_ksettings *cmd)
 374 {
 375         ethtool_link_ksettings_zero_link_mode(cmd, supported);
 376         ethtool_link_ksettings_add_link_mode(cmd, supported, Backplane);
 377         ethtool_link_ksettings_zero_link_mode(cmd, advertising);
 378         ethtool_link_ksettings_add_link_mode(cmd, advertising, Backplane);
 379
 380         cmd->base.speed = SPEED_UNKNOWN;
 381         cmd->base.duplex = DUPLEX_FULL;
 382         cmd->base.port = PORT_OTHER;
 383         cmd->base.phy_address = 0;
 384         cmd->base.autoneg = AUTONEG_ENABLE;
 385
 386         return 0;
 387 }
 388
 389 static const struct ethtool_ops ntb_ethtool_ops = {
 390         .get_drvinfo = ntb_get_drvinfo,
 391         .get_link = ethtool_op_get_link,
 392         .get_link_ksettings = ntb_get_link_ksettings,
 393 };
 394
 395 static const struct ntb_queue_handlers ntb_netdev_handlers = {
 396         .tx_handler = ntb_netdev_tx_handler,
 397         .rx_handler = ntb_netdev_rx_handler,
 398         .event_handler = ntb_netdev_event_handler,
 399 };
 400
 401 static int ntb_netdev_probe(struct device *client_dev)
 402 {
 403         struct ntb_dev *ntb;
 404         struct net_device *ndev;
 405         struct pci_dev *pdev;
 406         struct ntb_netdev *dev;
 407         int rc;
 408
 409         ntb = dev_ntb(client_dev->parent);
 410         pdev = ntb->pdev;
 411         if (!pdev)
 412                 return -ENODEV;
 413
 414         ndev = alloc_etherdev(sizeof(*dev));
 415         if (!ndev)
 416                 return -ENOMEM;
 417
 418         SET_NETDEV_DEV(ndev, client_dev);
 419
 420         dev = netdev_priv(ndev);
 421         dev->ndev = ndev;
 422         dev->pdev = pdev;
 423         ndev->features = NETIF_F_HIGHDMA;
 424
 425         ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 426
 427         ndev->hw_features = ndev->features;
 428         ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS);
 429
 430         eth_random_addr(ndev->perm_addr);
 431         memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len);
 432
 433         ndev->netdev_ops = &ntb_netdev_ops;
 434         ndev->ethtool_ops = &ntb_ethtool_ops;
 435
 436         ndev->min_mtu = 0;
 437         ndev->max_mtu = ETH_MAX_MTU;
 438
 439         dev->qp = ntb_transport_create_queue(ndev, client_dev,
 440                                              &ntb_netdev_handlers);
 441         if (!dev->qp) {
 442                 rc = -EIO;
 443                 goto err;
 444         }
 445
 446         ndev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN;
 447
 448         rc = register_netdev(ndev);
 449         if (rc)
 450                 goto err1;
 451
 452         dev_set_drvdata(client_dev, ndev);
 453         dev_info(&pdev->dev, "%s created\n", ndev->name);
 454         return 0;
 455
 456 err1:
 457         ntb_transport_free_queue(dev->qp);
 458 err:
 459         free_netdev(ndev);
 460         return rc;
 461 }
 462
 463 static void ntb_netdev_remove(struct device *client_dev)
 464 {
 465         struct net_device *ndev = dev_get_drvdata(client_dev);
 466         struct ntb_netdev *dev = netdev_priv(ndev);
 467
 468         unregister_netdev(ndev);
 469         ntb_transport_free_queue(dev->qp);
 470         free_netdev(ndev);
 471 }
 472
 473 static struct ntb_transport_client ntb_netdev_client = {
 474         .driver.name = KBUILD_MODNAME,
 475         .driver.owner = THIS_MODULE,
 476         .probe = ntb_netdev_probe,
 477         .remove = ntb_netdev_remove,
 478 };
 479
 480 static int __init ntb_netdev_init_module(void)
 481 {
 482         int rc;
 483
 484         rc = ntb_transport_register_client_dev(KBUILD_MODNAME);
 485         if (rc)
 486                 return rc;
 487         return ntb_transport_register_client(&ntb_netdev_client);
 488 }
 489 module_init(ntb_netdev_init_module);
 490
 491 static void __exit ntb_netdev_exit_module(void)
 492 {
 493         ntb_transport_unregister_client(&ntb_netdev_client);
 494         ntb_transport_unregister_client_dev(KBUILD_MODNAME);
 495 }
 496 module_exit(ntb_netdev_exit_module);