lib/librte_eal/linuxapp/kni/kni_misc.c

   1 /*-
   2  * GPL LICENSE SUMMARY
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of version 2 of the GNU General Public License as
   8  *   published by the Free Software Foundation.
   9  *
  10  *   This program is distributed in the hope that it will be useful, but
  11  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *   General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  *   The full GNU General Public License is included in this distribution
  19  *   in the file called LICENSE.GPL.
  20  *
  21  *   Contact Information:
  22  *   Intel Corporation
  23  */
  24
  25 #include <linux/version.h>
  26 #include <linux/module.h>
  27 #include <linux/miscdevice.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/etherdevice.h>
  30 #include <linux/pci.h>
  31 #include <linux/kthread.h>
  32 #include <linux/rwsem.h>
  33 #include <linux/mutex.h>
  34 #include <linux/nsproxy.h>
  35 #include <net/net_namespace.h>
  36 #include <net/netns/generic.h>
  37
  38 #include <exec-env/rte_kni_common.h>
  39
  40 #include "compat.h"
  41 #include "kni_dev.h"
  42
  43 MODULE_LICENSE("Dual BSD/GPL");
  44 MODULE_AUTHOR("Intel Corporation");
  45 MODULE_DESCRIPTION("Kernel Module for managing kni devices");
  46
  47 #define KNI_RX_LOOP_NUM 1000
  48
  49 #define KNI_MAX_DEVICES 32
  50
  51 extern const struct pci_device_id ixgbe_pci_tbl[];
  52 extern const struct pci_device_id igb_pci_tbl[];
  53
  54 /* loopback mode */
  55 static char *lo_mode;
  56
  57 /* Kernel thread mode */
  58 static char *kthread_mode;
  59 static uint32_t multiple_kthread_on;
  60
  61 #define KNI_DEV_IN_USE_BIT_NUM 0 /* Bit number for device in use */
  62
  63 static int kni_net_id;
  64
  65 struct kni_net {
  66         unsigned long device_in_use; /* device in use flag */
  67         struct mutex kni_kthread_lock;
  68         struct task_struct *kni_kthread;
  69         struct rw_semaphore kni_list_lock;
  70         struct list_head kni_list_head;
  71 };
  72
  73 static int __net_init
  74 kni_init_net(struct net *net)
  75 {
  76 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
  77         struct kni_net *knet = net_generic(net, kni_net_id);
  78
  79         memset(knet, 0, sizeof(*knet));
  80 #else
  81         struct kni_net *knet;
  82         int ret;
  83
  84         knet = kzalloc(sizeof(struct kni_net), GFP_KERNEL);
  85         if (!knet) {
  86                 ret = -ENOMEM;
  87                 return ret;
  88         }
  89 #endif
  90
  91         /* Clear the bit of device in use */
  92         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
  93
  94         mutex_init(&knet->kni_kthread_lock);
  95
  96         init_rwsem(&knet->kni_list_lock);
  97         INIT_LIST_HEAD(&knet->kni_list_head);
  98
  99 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 100         return 0;
 101 #else
 102         ret = net_assign_generic(net, kni_net_id, knet);
 103         if (ret < 0)
 104                 kfree(knet);
 105
 106         return ret;
 107 #endif
 108 }
 109
 110 static void __net_exit
 111 kni_exit_net(struct net *net)
 112 {
 113         struct kni_net *knet __maybe_unused;
 114
 115         knet = net_generic(net, kni_net_id);
 116         mutex_destroy(&knet->kni_kthread_lock);
 117
 118 #ifndef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 119         kfree(knet);
 120 #endif
 121 }
 122
 123 static struct pernet_operations kni_net_ops = {
 124         .init = kni_init_net,
 125         .exit = kni_exit_net,
 126 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 127         .id   = &kni_net_id,
 128         .size = sizeof(struct kni_net),
 129 #endif
 130 };
 131
 132 static int
 133 kni_thread_single(void *data)
 134 {
 135         struct kni_net *knet = data;
 136         int j;
 137         struct kni_dev *dev;
 138
 139         while (!kthread_should_stop()) {
 140                 down_read(&knet->kni_list_lock);
 141                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 142                         list_for_each_entry(dev, &knet->kni_list_head, list) {
 143 #ifdef RTE_KNI_VHOST
 144                                 kni_chk_vhost_rx(dev);
 145 #else
 146                                 kni_net_rx(dev);
 147 #endif
 148                                 kni_net_poll_resp(dev);
 149                         }
 150                 }
 151                 up_read(&knet->kni_list_lock);
 152 #ifdef RTE_KNI_PREEMPT_DEFAULT
 153                 /* reschedule out for a while */
 154                 schedule_timeout_interruptible(
 155                         usecs_to_jiffies(KNI_KTHREAD_RESCHEDULE_INTERVAL));
 156 #endif
 157         }
 158
 159         return 0;
 160 }
 161
 162 static int
 163 kni_thread_multiple(void *param)
 164 {
 165         int j;
 166         struct kni_dev *dev = (struct kni_dev *)param;
 167
 168         while (!kthread_should_stop()) {
 169                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 170 #ifdef RTE_KNI_VHOST
 171                         kni_chk_vhost_rx(dev);
 172 #else
 173                         kni_net_rx(dev);
 174 #endif
 175                         kni_net_poll_resp(dev);
 176                 }
 177 #ifdef RTE_KNI_PREEMPT_DEFAULT
 178                 schedule_timeout_interruptible(
 179                         usecs_to_jiffies(KNI_KTHREAD_RESCHEDULE_INTERVAL));
 180 #endif
 181         }
 182
 183         return 0;
 184 }
 185
 186 static int
 187 kni_open(struct inode *inode, struct file *file)
 188 {
 189         struct net *net = current->nsproxy->net_ns;
 190         struct kni_net *knet = net_generic(net, kni_net_id);
 191
 192         /* kni device can be opened by one user only per netns */
 193         if (test_and_set_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use))
 194                 return -EBUSY;
 195
 196         file->private_data = get_net(net);
 197         pr_debug("/dev/kni opened\n");
 198
 199         return 0;
 200 }
 201
 202 static int
 203 kni_dev_remove(struct kni_dev *dev)
 204 {
 205         if (!dev)
 206                 return -ENODEV;
 207
 208         if (dev->pci_dev) {
 209                 if (pci_match_id(ixgbe_pci_tbl, dev->pci_dev))
 210                         ixgbe_kni_remove(dev->pci_dev);
 211                 else if (pci_match_id(igb_pci_tbl, dev->pci_dev))
 212                         igb_kni_remove(dev->pci_dev);
 213         }
 214
 215         if (dev->net_dev) {
 216                 unregister_netdev(dev->net_dev);
 217                 free_netdev(dev->net_dev);
 218         }
 219
 220         return 0;
 221 }
 222
 223 static int
 224 kni_release(struct inode *inode, struct file *file)
 225 {
 226         struct net *net = file->private_data;
 227         struct kni_net *knet = net_generic(net, kni_net_id);
 228         struct kni_dev *dev, *n;
 229
 230         /* Stop kernel thread for single mode */
 231         if (multiple_kthread_on == 0) {
 232                 mutex_lock(&knet->kni_kthread_lock);
 233                 /* Stop kernel thread */
 234                 if (knet->kni_kthread != NULL) {
 235                         kthread_stop(knet->kni_kthread);
 236                         knet->kni_kthread = NULL;
 237                 }
 238                 mutex_unlock(&knet->kni_kthread_lock);
 239         }
 240
 241         down_write(&knet->kni_list_lock);
 242         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 243                 /* Stop kernel thread for multiple mode */
 244                 if (multiple_kthread_on && dev->pthread != NULL) {
 245                         kthread_stop(dev->pthread);
 246                         dev->pthread = NULL;
 247                 }
 248
 249 #ifdef RTE_KNI_VHOST
 250                 kni_vhost_backend_release(dev);
 251 #endif
 252                 kni_dev_remove(dev);
 253                 list_del(&dev->list);
 254         }
 255         up_write(&knet->kni_list_lock);
 256
 257         /* Clear the bit of device in use */
 258         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
 259
 260         put_net(net);
 261         pr_debug("/dev/kni closed\n");
 262
 263         return 0;
 264 }
 265
 266 static int
 267 kni_check_param(struct kni_dev *kni, struct rte_kni_device_info *dev)
 268 {
 269         if (!kni || !dev)
 270                 return -1;
 271
 272         /* Check if network name has been used */
 273         if (!strncmp(kni->name, dev->name, RTE_KNI_NAMESIZE)) {
 274                 pr_err("KNI name %s duplicated\n", dev->name);
 275                 return -1;
 276         }
 277
 278         return 0;
 279 }
 280
 281 static int
 282 kni_run_thread(struct kni_net *knet, struct kni_dev *kni, uint8_t force_bind)
 283 {
 284         /**
 285          * Create a new kernel thread for multiple mode, set its core affinity,
 286          * and finally wake it up.
 287          */
 288         if (multiple_kthread_on) {
 289                 kni->pthread = kthread_create(kni_thread_multiple,
 290                         (void *)kni, "kni_%s", kni->name);
 291                 if (IS_ERR(kni->pthread)) {
 292                         kni_dev_remove(kni);
 293                         return -ECANCELED;
 294                 }
 295
 296                 if (force_bind)
 297                         kthread_bind(kni->pthread, kni->core_id);
 298                 wake_up_process(kni->pthread);
 299         } else {
 300                 mutex_lock(&knet->kni_kthread_lock);
 301
 302                 if (knet->kni_kthread == NULL) {
 303                         knet->kni_kthread = kthread_create(kni_thread_single,
 304                                 (void *)knet, "kni_single");
 305                         if (IS_ERR(knet->kni_kthread)) {
 306                                 mutex_unlock(&knet->kni_kthread_lock);
 307                                 kni_dev_remove(kni);
 308                                 return -ECANCELED;
 309                         }
 310
 311                         if (force_bind)
 312                                 kthread_bind(knet->kni_kthread, kni->core_id);
 313                         wake_up_process(knet->kni_kthread);
 314                 }
 315
 316                 mutex_unlock(&knet->kni_kthread_lock);
 317         }
 318
 319         return 0;
 320 }
 321
 322 static int
 323 kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 324                 unsigned long ioctl_param)
 325 {
 326         struct kni_net *knet = net_generic(net, kni_net_id);
 327         int ret;
 328         struct rte_kni_device_info dev_info;
 329         struct pci_dev *pci = NULL;
 330         struct pci_dev *found_pci = NULL;
 331         struct net_device *net_dev = NULL;
 332         struct net_device *lad_dev = NULL;
 333         struct kni_dev *kni, *dev, *n;
 334
 335         pr_info("Creating kni...\n");
 336         /* Check the buffer size, to avoid warning */
 337         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 338                 return -EINVAL;
 339
 340         /* Copy kni info from user space */
 341         ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
 342         if (ret) {
 343                 pr_err("copy_from_user in kni_ioctl_create");
 344                 return -EIO;
 345         }
 346
 347         /**
 348          * Check if the cpu core id is valid for binding.
 349          */
 350         if (dev_info.force_bind && !cpu_online(dev_info.core_id)) {
 351                 pr_err("cpu %u is not online\n", dev_info.core_id);
 352                 return -EINVAL;
 353         }
 354
 355         /* Check if it has been created */
 356         down_read(&knet->kni_list_lock);
 357         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 358                 if (kni_check_param(dev, &dev_info) < 0) {
 359                         up_read(&knet->kni_list_lock);
 360                         return -EINVAL;
 361                 }
 362         }
 363         up_read(&knet->kni_list_lock);
 364
 365         net_dev = alloc_netdev(sizeof(struct kni_dev), dev_info.name,
 366 #ifdef NET_NAME_UNKNOWN
 367                                                         NET_NAME_UNKNOWN,
 368 #endif
 369                                                         kni_net_init);
 370         if (net_dev == NULL) {
 371                 pr_err("error allocating device \"%s\"\n", dev_info.name);
 372                 return -EBUSY;
 373         }
 374
 375         dev_net_set(net_dev, net);
 376
 377         kni = netdev_priv(net_dev);
 378
 379         kni->net_dev = net_dev;
 380         kni->group_id = dev_info.group_id;
 381         kni->core_id = dev_info.core_id;
 382         strncpy(kni->name, dev_info.name, RTE_KNI_NAMESIZE);
 383
 384         /* Translate user space info into kernel space info */
 385         kni->tx_q = phys_to_virt(dev_info.tx_phys);
 386         kni->rx_q = phys_to_virt(dev_info.rx_phys);
 387         kni->alloc_q = phys_to_virt(dev_info.alloc_phys);
 388         kni->free_q = phys_to_virt(dev_info.free_phys);
 389
 390         kni->req_q = phys_to_virt(dev_info.req_phys);
 391         kni->resp_q = phys_to_virt(dev_info.resp_phys);
 392         kni->sync_va = dev_info.sync_va;
 393         kni->sync_kva = phys_to_virt(dev_info.sync_phys);
 394
 395 #ifdef RTE_KNI_VHOST
 396         kni->vhost_queue = NULL;
 397         kni->vq_status = BE_STOP;
 398 #endif
 399         kni->mbuf_size = dev_info.mbuf_size;
 400
 401         pr_debug("tx_phys:      0x%016llx, tx_q addr:      0x%p\n",
 402                 (unsigned long long) dev_info.tx_phys, kni->tx_q);
 403         pr_debug("rx_phys:      0x%016llx, rx_q addr:      0x%p\n",
 404                 (unsigned long long) dev_info.rx_phys, kni->rx_q);
 405         pr_debug("alloc_phys:   0x%016llx, alloc_q addr:   0x%p\n",
 406                 (unsigned long long) dev_info.alloc_phys, kni->alloc_q);
 407         pr_debug("free_phys:    0x%016llx, free_q addr:    0x%p\n",
 408                 (unsigned long long) dev_info.free_phys, kni->free_q);
 409         pr_debug("req_phys:     0x%016llx, req_q addr:     0x%p\n",
 410                 (unsigned long long) dev_info.req_phys, kni->req_q);
 411         pr_debug("resp_phys:    0x%016llx, resp_q addr:    0x%p\n",
 412                 (unsigned long long) dev_info.resp_phys, kni->resp_q);
 413         pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 414
 415         pr_debug("PCI: %02x:%02x.%02x %04x:%04x\n",
 416                                         dev_info.bus,
 417                                         dev_info.devid,
 418                                         dev_info.function,
 419                                         dev_info.vendor_id,
 420                                         dev_info.device_id);
 421
 422         pci = pci_get_device(dev_info.vendor_id, dev_info.device_id, NULL);
 423
 424         /* Support Ethtool */
 425         while (pci) {
 426                 pr_debug("pci_bus: %02x:%02x:%02x\n",
 427                                         pci->bus->number,
 428                                         PCI_SLOT(pci->devfn),
 429                                         PCI_FUNC(pci->devfn));
 430
 431                 if ((pci->bus->number == dev_info.bus) &&
 432                         (PCI_SLOT(pci->devfn) == dev_info.devid) &&
 433                         (PCI_FUNC(pci->devfn) == dev_info.function)) {
 434                         found_pci = pci;
 435
 436                         if (pci_match_id(ixgbe_pci_tbl, found_pci))
 437                                 ret = ixgbe_kni_probe(found_pci, &lad_dev);
 438                         else if (pci_match_id(igb_pci_tbl, found_pci))
 439                                 ret = igb_kni_probe(found_pci, &lad_dev);
 440                         else
 441                                 ret = -1;
 442
 443                         pr_debug("PCI found: pci=0x%p, lad_dev=0x%p\n",
 444                                                         pci, lad_dev);
 445                         if (ret == 0) {
 446                                 kni->lad_dev = lad_dev;
 447                                 kni_set_ethtool_ops(kni->net_dev);
 448                         } else {
 449                                 pr_err("Device not supported by ethtool");
 450                                 kni->lad_dev = NULL;
 451                         }
 452
 453                         kni->pci_dev = found_pci;
 454                         kni->device_id = dev_info.device_id;
 455                         break;
 456                 }
 457                 pci = pci_get_device(dev_info.vendor_id,
 458                                 dev_info.device_id, pci);
 459         }
 460         if (pci)
 461                 pci_dev_put(pci);
 462
 463         if (kni->lad_dev)
 464                 ether_addr_copy(net_dev->dev_addr, kni->lad_dev->dev_addr);
 465         else
 466                 /*
 467                  * Generate random mac address. eth_random_addr() is the newer
 468                  * version of generating mac address in linux kernel.
 469                  */
 470                 random_ether_addr(net_dev->dev_addr);
 471
 472         ret = register_netdev(net_dev);
 473         if (ret) {
 474                 pr_err("error %i registering device \"%s\"\n",
 475                                         ret, dev_info.name);
 476                 kni->net_dev = NULL;
 477                 kni_dev_remove(kni);
 478                 free_netdev(net_dev);
 479                 return -ENODEV;
 480         }
 481
 482 #ifdef RTE_KNI_VHOST
 483         kni_vhost_init(kni);
 484 #endif
 485
 486         ret = kni_run_thread(knet, kni, dev_info.force_bind);
 487         if (ret != 0)
 488                 return ret;
 489
 490         down_write(&knet->kni_list_lock);
 491         list_add(&kni->list, &knet->kni_list_head);
 492         up_write(&knet->kni_list_lock);
 493
 494         return 0;
 495 }
 496
 497 static int
 498 kni_ioctl_release(struct net *net, uint32_t ioctl_num,
 499                 unsigned long ioctl_param)
 500 {
 501         struct kni_net *knet = net_generic(net, kni_net_id);
 502         int ret = -EINVAL;
 503         struct kni_dev *dev, *n;
 504         struct rte_kni_device_info dev_info;
 505
 506         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 507                 return -EINVAL;
 508
 509         ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
 510         if (ret) {
 511                 pr_err("copy_from_user in kni_ioctl_release");
 512                 return -EIO;
 513         }
 514
 515         /* Release the network device according to its name */
 516         if (strlen(dev_info.name) == 0)
 517                 return ret;
 518
 519         down_write(&knet->kni_list_lock);
 520         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 521                 if (strncmp(dev->name, dev_info.name, RTE_KNI_NAMESIZE) != 0)
 522                         continue;
 523
 524                 if (multiple_kthread_on && dev->pthread != NULL) {
 525                         kthread_stop(dev->pthread);
 526                         dev->pthread = NULL;
 527                 }
 528
 529 #ifdef RTE_KNI_VHOST
 530                 kni_vhost_backend_release(dev);
 531 #endif
 532                 kni_dev_remove(dev);
 533                 list_del(&dev->list);
 534                 ret = 0;
 535                 break;
 536         }
 537         up_write(&knet->kni_list_lock);
 538         pr_info("%s release kni named %s\n",
 539                 (ret == 0 ? "Successfully" : "Unsuccessfully"), dev_info.name);
 540
 541         return ret;
 542 }
 543
 544 static int
 545 kni_ioctl(struct inode *inode, uint32_t ioctl_num, unsigned long ioctl_param)
 546 {
 547         int ret = -EINVAL;
 548         struct net *net = current->nsproxy->net_ns;
 549
 550         pr_debug("IOCTL num=0x%0x param=0x%0lx\n", ioctl_num, ioctl_param);
 551
 552         /*
 553          * Switch according to the ioctl called
 554          */
 555         switch (_IOC_NR(ioctl_num)) {
 556         case _IOC_NR(RTE_KNI_IOCTL_TEST):
 557                 /* For test only, not used */
 558                 break;
 559         case _IOC_NR(RTE_KNI_IOCTL_CREATE):
 560                 ret = kni_ioctl_create(net, ioctl_num, ioctl_param);
 561                 break;
 562         case _IOC_NR(RTE_KNI_IOCTL_RELEASE):
 563                 ret = kni_ioctl_release(net, ioctl_num, ioctl_param);
 564                 break;
 565         default:
 566                 pr_debug("IOCTL default\n");
 567                 break;
 568         }
 569
 570         return ret;
 571 }
 572
 573 static int
 574 kni_compat_ioctl(struct inode *inode, uint32_t ioctl_num,
 575                 unsigned long ioctl_param)
 576 {
 577         /* 32 bits app on 64 bits OS to be supported later */
 578         pr_debug("Not implemented.\n");
 579
 580         return -EINVAL;
 581 }
 582
 583 static const struct file_operations kni_fops = {
 584         .owner = THIS_MODULE,
 585         .open = kni_open,
 586         .release = kni_release,
 587         .unlocked_ioctl = (void *)kni_ioctl,
 588         .compat_ioctl = (void *)kni_compat_ioctl,
 589 };
 590
 591 static struct miscdevice kni_misc = {
 592         .minor = MISC_DYNAMIC_MINOR,
 593         .name = KNI_DEVICE,
 594         .fops = &kni_fops,
 595 };
 596
 597 static int __init
 598 kni_parse_kthread_mode(void)
 599 {
 600         if (!kthread_mode)
 601                 return 0;
 602
 603         if (strcmp(kthread_mode, "single") == 0)
 604                 return 0;
 605         else if (strcmp(kthread_mode, "multiple") == 0)
 606                 multiple_kthread_on = 1;
 607         else
 608                 return -1;
 609
 610         return 0;
 611 }
 612
 613 static int __init
 614 kni_init(void)
 615 {
 616         int rc;
 617
 618         if (kni_parse_kthread_mode() < 0) {
 619                 pr_err("Invalid parameter for kthread_mode\n");
 620                 return -EINVAL;
 621         }
 622
 623         if (multiple_kthread_on == 0)
 624                 pr_debug("Single kernel thread for all KNI devices\n");
 625         else
 626                 pr_debug("Multiple kernel thread mode enabled\n");
 627
 628 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 629         rc = register_pernet_subsys(&kni_net_ops);
 630 #else
 631         rc = register_pernet_gen_subsys(&kni_net_id, &kni_net_ops);
 632 #endif
 633         if (rc)
 634                 return -EPERM;
 635
 636         rc = misc_register(&kni_misc);
 637         if (rc != 0) {
 638                 pr_err("Misc registration failed\n");
 639                 goto out;
 640         }
 641
 642         /* Configure the lo mode according to the input parameter */
 643         kni_net_config_lo_mode(lo_mode);
 644
 645         return 0;
 646
 647 out:
 648 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 649         unregister_pernet_subsys(&kni_net_ops);
 650 #else
 651         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 652 #endif
 653         return rc;
 654 }
 655
 656 static void __exit
 657 kni_exit(void)
 658 {
 659         misc_deregister(&kni_misc);
 660 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 661         unregister_pernet_subsys(&kni_net_ops);
 662 #else
 663         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 664 #endif
 665 }
 666
 667 module_init(kni_init);
 668 module_exit(kni_exit);
 669
 670 module_param(lo_mode, charp, S_IRUGO | S_IWUSR);
 671 MODULE_PARM_DESC(lo_mode,
 672 "KNI loopback mode (default=lo_mode_none):\n"
 673 "    lo_mode_none        Kernel loopback disabled\n"
 674 "    lo_mode_fifo        Enable kernel loopback with fifo\n"
 675 "    lo_mode_fifo_skb    Enable kernel loopback with fifo and skb buffer\n"
 676 "\n"
 677 );
 678
 679 module_param(kthread_mode, charp, S_IRUGO);
 680 MODULE_PARM_DESC(kthread_mode,
 681 "Kernel thread mode (default=single):\n"
 682 "    single    Single kernel thread mode enabled.\n"
 683 "    multiple  Multiple kernel thread mode enabled.\n"
 684 "\n"
 685 );