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 list_head list;
  75         struct pci_dev *pdev;
  76         struct net_device *ndev;
  77         struct ntb_transport_qp *qp;
  78         struct timer_list tx_timer;
  79 };
  80
  81 #define NTB_TX_TIMEOUT_MS       1000
  82 #define NTB_RXQ_SIZE            100
  83
  84 static LIST_HEAD(dev_list);
  85
  86 static void ntb_netdev_event_handler(void *data, int link_is_up)
  87 {
  88         struct net_device *ndev = data;
  89         struct ntb_netdev *dev = netdev_priv(ndev);
  90
  91         netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up,
  92                    ntb_transport_link_query(dev->qp));
  93
  94         if (link_is_up) {
  95                 if (ntb_transport_link_query(dev->qp))
  96                         netif_carrier_on(ndev);
  97         } else {
  98                 netif_carrier_off(ndev);
  99         }
 100 }
 101
 102 static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
 103                                   void *data, int len)
 104 {
 105         struct net_device *ndev = qp_data;
 106         struct sk_buff *skb;
 107         int rc;
 108
 109         skb = data;
 110         if (!skb)
 111                 return;
 112
 113         netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len);
 114
 115         if (len < 0) {
 116                 ndev->stats.rx_errors++;
 117                 ndev->stats.rx_length_errors++;
 118                 goto enqueue_again;
 119         }
 120
 121         skb_put(skb, len);
 122         skb->protocol = eth_type_trans(skb, ndev);
 123         skb->ip_summed = CHECKSUM_NONE;
 124
 125         if (netif_rx(skb) == NET_RX_DROP) {
 126                 ndev->stats.rx_errors++;
 127                 ndev->stats.rx_dropped++;
 128         } else {
 129                 ndev->stats.rx_packets++;
 130                 ndev->stats.rx_bytes += len;
 131         }
 132
 133         skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
 134         if (!skb) {
 135                 ndev->stats.rx_errors++;
 136                 ndev->stats.rx_frame_errors++;
 137                 return;
 138         }
 139
 140 enqueue_again:
 141         rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
 142         if (rc) {
 143                 dev_kfree_skb(skb);
 144                 ndev->stats.rx_errors++;
 145                 ndev->stats.rx_fifo_errors++;
 146         }
 147 }
 148
 149 static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev,
 150                                       struct ntb_transport_qp *qp, int size)
 151 {
 152         struct ntb_netdev *dev = netdev_priv(netdev);
 153
 154         netif_stop_queue(netdev);
 155         /* Make sure to see the latest value of ntb_transport_tx_free_entry()
 156          * since the queue was last started.
 157          */
 158         smp_mb();
 159
 160         if (likely(ntb_transport_tx_free_entry(qp) < size)) {
 161                 mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time));
 162                 return -EBUSY;
 163         }
 164
 165         netif_start_queue(netdev);
 166         return 0;
 167 }
 168
 169 static int ntb_netdev_maybe_stop_tx(struct net_device *ndev,
 170                                     struct ntb_transport_qp *qp, int size)
 171 {
 172         if (netif_queue_stopped(ndev) ||
 173             (ntb_transport_tx_free_entry(qp) >= size))
 174                 return 0;
 175
 176         return __ntb_netdev_maybe_stop_tx(ndev, qp, size);
 177 }
 178
 179 static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
 180                                   void *data, int len)
 181 {
 182         struct net_device *ndev = qp_data;
 183         struct sk_buff *skb;
 184         struct ntb_netdev *dev = netdev_priv(ndev);
 185
 186         skb = data;
 187         if (!skb || !ndev)
 188                 return;
 189
 190         if (len > 0) {
 191                 ndev->stats.tx_packets++;
 192                 ndev->stats.tx_bytes += skb->len;
 193         } else {
 194                 ndev->stats.tx_errors++;
 195                 ndev->stats.tx_aborted_errors++;
 196         }
 197
 198         dev_kfree_skb(skb);
 199
 200         if (ntb_transport_tx_free_entry(dev->qp) >= tx_start) {
 201                 /* Make sure anybody stopping the queue after this sees the new
 202                  * value of ntb_transport_tx_free_entry()
 203                  */
 204                 smp_mb();
 205                 if (netif_queue_stopped(ndev))
 206                         netif_wake_queue(ndev);
 207         }
 208 }
 209
 210 static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
 211                                          struct net_device *ndev)
 212 {
 213         struct ntb_netdev *dev = netdev_priv(ndev);
 214         int rc;
 215
 216         ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);
 217
 218         rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
 219         if (rc)
 220                 goto err;
 221
 222         /* check for next submit */
 223         ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);
 224
 225         return NETDEV_TX_OK;
 226
 227 err:
 228         ndev->stats.tx_dropped++;
 229         ndev->stats.tx_errors++;
 230         return NETDEV_TX_BUSY;
 231 }
 232
 233 static void ntb_netdev_tx_timer(unsigned long data)
 234 {
 235         struct net_device *ndev = (struct net_device *)data;
 236         struct ntb_netdev *dev = netdev_priv(ndev);
 237
 238         if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) {
 239                 mod_timer(&dev->tx_timer, jiffies + msecs_to_jiffies(tx_time));
 240         } else {
 241                 /* Make sure anybody stopping the queue after this sees the new
 242                  * value of ntb_transport_tx_free_entry()
 243                  */
 244                 smp_mb();
 245                 if (netif_queue_stopped(ndev))
 246                         netif_wake_queue(ndev);
 247         }
 248 }
 249
 250 static int ntb_netdev_open(struct net_device *ndev)
 251 {
 252         struct ntb_netdev *dev = netdev_priv(ndev);
 253         struct sk_buff *skb;
 254         int rc, i, len;
 255
 256         /* Add some empty rx bufs */
 257         for (i = 0; i < NTB_RXQ_SIZE; i++) {
 258                 skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
 259                 if (!skb) {
 260                         rc = -ENOMEM;
 261                         goto err;
 262                 }
 263
 264                 rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
 265                                               ndev->mtu + ETH_HLEN);
 266                 if (rc) {
 267                         dev_kfree_skb(skb);
 268                         goto err;
 269                 }
 270         }
 271
 272         setup_timer(&dev->tx_timer, ntb_netdev_tx_timer, (unsigned long)ndev);
 273
 274         netif_carrier_off(ndev);
 275         ntb_transport_link_up(dev->qp);
 276         netif_start_queue(ndev);
 277
 278         return 0;
 279
 280 err:
 281         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 282                 dev_kfree_skb(skb);
 283         return rc;
 284 }
 285
 286 static int ntb_netdev_close(struct net_device *ndev)
 287 {
 288         struct ntb_netdev *dev = netdev_priv(ndev);
 289         struct sk_buff *skb;
 290         int len;
 291
 292         ntb_transport_link_down(dev->qp);
 293
 294         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 295                 dev_kfree_skb(skb);
 296
 297         del_timer_sync(&dev->tx_timer);
 298
 299         return 0;
 300 }
 301
 302 static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu)
 303 {
 304         struct ntb_netdev *dev = netdev_priv(ndev);
 305         struct sk_buff *skb;
 306         int len, rc;
 307
 308         if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN)
 309                 return -EINVAL;
 310
 311         if (!netif_running(ndev)) {
 312                 ndev->mtu = new_mtu;
 313                 return 0;
 314         }
 315
 316         /* Bring down the link and dispose of posted rx entries */
 317         ntb_transport_link_down(dev->qp);
 318
 319         if (ndev->mtu < new_mtu) {
 320                 int i;
 321
 322                 for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++)
 323                         dev_kfree_skb(skb);
 324
 325                 for (; i; i--) {
 326                         skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN);
 327                         if (!skb) {
 328                                 rc = -ENOMEM;
 329                                 goto err;
 330                         }
 331
 332                         rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
 333                                                       new_mtu + ETH_HLEN);
 334                         if (rc) {
 335                                 dev_kfree_skb(skb);
 336                                 goto err;
 337                         }
 338                 }
 339         }
 340
 341         ndev->mtu = new_mtu;
 342
 343         ntb_transport_link_up(dev->qp);
 344
 345         return 0;
 346
 347 err:
 348         ntb_transport_link_down(dev->qp);
 349
 350         while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
 351                 dev_kfree_skb(skb);
 352
 353         netdev_err(ndev, "Error changing MTU, device inoperable\n");
 354         return rc;
 355 }
 356
 357 static const struct net_device_ops ntb_netdev_ops = {
 358         .ndo_open = ntb_netdev_open,
 359         .ndo_stop = ntb_netdev_close,
 360         .ndo_start_xmit = ntb_netdev_start_xmit,
 361         .ndo_change_mtu = ntb_netdev_change_mtu,
 362         .ndo_set_mac_address = eth_mac_addr,
 363 };
 364
 365 static void ntb_get_drvinfo(struct net_device *ndev,
 366                             struct ethtool_drvinfo *info)
 367 {
 368         struct ntb_netdev *dev = netdev_priv(ndev);
 369
 370         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 371         strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
 372         strlcpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info));
 373 }
 374
 375 static int ntb_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 376 {
 377         cmd->supported = SUPPORTED_Backplane;
 378         cmd->advertising = ADVERTISED_Backplane;
 379         ethtool_cmd_speed_set(cmd, SPEED_UNKNOWN);
 380         cmd->duplex = DUPLEX_FULL;
 381         cmd->port = PORT_OTHER;
 382         cmd->phy_address = 0;
 383         cmd->transceiver = XCVR_DUMMY1;
 384         cmd->autoneg = AUTONEG_ENABLE;
 385         cmd->maxtxpkt = 0;
 386         cmd->maxrxpkt = 0;
 387
 388         return 0;
 389 }
 390
 391 static const struct ethtool_ops ntb_ethtool_ops = {
 392         .get_drvinfo = ntb_get_drvinfo,
 393         .get_link = ethtool_op_get_link,
 394         .get_settings = ntb_get_settings,
 395 };
 396
 397 static const struct ntb_queue_handlers ntb_netdev_handlers = {
 398         .tx_handler = ntb_netdev_tx_handler,
 399         .rx_handler = ntb_netdev_rx_handler,
 400         .event_handler = ntb_netdev_event_handler,
 401 };
 402
 403 static int ntb_netdev_probe(struct device *client_dev)
 404 {
 405         struct ntb_dev *ntb;
 406         struct net_device *ndev;
 407         struct pci_dev *pdev;
 408         struct ntb_netdev *dev;
 409         int rc;
 410
 411         ntb = dev_ntb(client_dev->parent);
 412         pdev = ntb->pdev;
 413         if (!pdev)
 414                 return -ENODEV;
 415
 416         ndev = alloc_etherdev(sizeof(*dev));
 417         if (!ndev)
 418                 return -ENOMEM;
 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         random_ether_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         list_add(&dev->list, &dev_list);
 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 ntb_dev *ntb;
 466         struct net_device *ndev;
 467         struct pci_dev *pdev;
 468         struct ntb_netdev *dev;
 469         bool found = false;
 470
 471         ntb = dev_ntb(client_dev->parent);
 472         pdev = ntb->pdev;
 473
 474         list_for_each_entry(dev, &dev_list, list) {
 475                 if (dev->pdev == pdev) {
 476                         found = true;
 477                         break;
 478                 }
 479         }
 480         if (!found)
 481                 return;
 482
 483         list_del(&dev->list);
 484
 485         ndev = dev->ndev;
 486
 487         unregister_netdev(ndev);
 488         ntb_transport_free_queue(dev->qp);
 489         free_netdev(ndev);
 490 }
 491
 492 static struct ntb_transport_client ntb_netdev_client = {
 493         .driver.name = KBUILD_MODNAME,
 494         .driver.owner = THIS_MODULE,
 495         .probe = ntb_netdev_probe,
 496         .remove = ntb_netdev_remove,
 497 };
 498
 499 static int __init ntb_netdev_init_module(void)
 500 {
 501         int rc;
 502
 503         rc = ntb_transport_register_client_dev(KBUILD_MODNAME);
 504         if (rc)
 505                 return rc;
 506         return ntb_transport_register_client(&ntb_netdev_client);
 507 }
 508 module_init(ntb_netdev_init_module);
 509
 510 static void __exit ntb_netdev_exit_module(void)
 511 {
 512         ntb_transport_unregister_client(&ntb_netdev_client);
 513         ntb_transport_unregister_client_dev(KBUILD_MODNAME);
 514 }
 515 module_exit(ntb_netdev_exit_module);