ceph/src/seastar/dpdk/kernel/linux/kni/kni_misc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright(c) 2010-2014 Intel Corporation.
   4  */
   5
   6 #include <linux/version.h>
   7 #include <linux/module.h>
   8 #include <linux/miscdevice.h>
   9 #include <linux/netdevice.h>
  10 #include <linux/etherdevice.h>
  11 #include <linux/pci.h>
  12 #include <linux/kthread.h>
  13 #include <linux/rwsem.h>
  14 #include <linux/mutex.h>
  15 #include <linux/nsproxy.h>
  16 #include <net/net_namespace.h>
  17 #include <net/netns/generic.h>
  18
  19 #include <rte_kni_common.h>
  20
  21 #include "compat.h"
  22 #include "kni_dev.h"
  23
  24 MODULE_LICENSE("Dual BSD/GPL");
  25 MODULE_AUTHOR("Intel Corporation");
  26 MODULE_DESCRIPTION("Kernel Module for managing kni devices");
  27
  28 #define KNI_RX_LOOP_NUM 1000
  29
  30 #define KNI_MAX_DEVICES 32
  31
  32 extern const struct pci_device_id ixgbe_pci_tbl[];
  33 extern const struct pci_device_id igb_pci_tbl[];
  34
  35 /* loopback mode */
  36 static char *lo_mode;
  37
  38 /* Kernel thread mode */
  39 static char *kthread_mode;
  40 static uint32_t multiple_kthread_on;
  41
  42 /* Default carrier state for created KNI network interfaces */
  43 static char *carrier;
  44 uint32_t dflt_carrier;
  45
  46 #define KNI_DEV_IN_USE_BIT_NUM 0 /* Bit number for device in use */
  47
  48 static int kni_net_id;
  49
  50 struct kni_net {
  51         unsigned long device_in_use; /* device in use flag */
  52         struct mutex kni_kthread_lock;
  53         struct task_struct *kni_kthread;
  54         struct rw_semaphore kni_list_lock;
  55         struct list_head kni_list_head;
  56 };
  57
  58 static int __net_init
  59 kni_init_net(struct net *net)
  60 {
  61 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
  62         struct kni_net *knet = net_generic(net, kni_net_id);
  63
  64         memset(knet, 0, sizeof(*knet));
  65 #else
  66         struct kni_net *knet;
  67         int ret;
  68
  69         knet = kzalloc(sizeof(struct kni_net), GFP_KERNEL);
  70         if (!knet) {
  71                 ret = -ENOMEM;
  72                 return ret;
  73         }
  74 #endif
  75
  76         /* Clear the bit of device in use */
  77         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
  78
  79         mutex_init(&knet->kni_kthread_lock);
  80
  81         init_rwsem(&knet->kni_list_lock);
  82         INIT_LIST_HEAD(&knet->kni_list_head);
  83
  84 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
  85         return 0;
  86 #else
  87         ret = net_assign_generic(net, kni_net_id, knet);
  88         if (ret < 0)
  89                 kfree(knet);
  90
  91         return ret;
  92 #endif
  93 }
  94
  95 static void __net_exit
  96 kni_exit_net(struct net *net)
  97 {
  98         struct kni_net *knet __maybe_unused;
  99
 100         knet = net_generic(net, kni_net_id);
 101         mutex_destroy(&knet->kni_kthread_lock);
 102
 103 #ifndef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 104         kfree(knet);
 105 #endif
 106 }
 107
 108 static struct pernet_operations kni_net_ops = {
 109         .init = kni_init_net,
 110         .exit = kni_exit_net,
 111 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 112         .id   = &kni_net_id,
 113         .size = sizeof(struct kni_net),
 114 #endif
 115 };
 116
 117 static int
 118 kni_thread_single(void *data)
 119 {
 120         struct kni_net *knet = data;
 121         int j;
 122         struct kni_dev *dev;
 123
 124         while (!kthread_should_stop()) {
 125                 down_read(&knet->kni_list_lock);
 126                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 127                         list_for_each_entry(dev, &knet->kni_list_head, list) {
 128                                 kni_net_rx(dev);
 129                                 kni_net_poll_resp(dev);
 130                         }
 131                 }
 132                 up_read(&knet->kni_list_lock);
 133 #ifdef RTE_KNI_PREEMPT_DEFAULT
 134                 /* reschedule out for a while */
 135                 schedule_timeout_interruptible(
 136                         usecs_to_jiffies(KNI_KTHREAD_RESCHEDULE_INTERVAL));
 137 #endif
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int
 144 kni_thread_multiple(void *param)
 145 {
 146         int j;
 147         struct kni_dev *dev = param;
 148
 149         while (!kthread_should_stop()) {
 150                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 151                         kni_net_rx(dev);
 152                         kni_net_poll_resp(dev);
 153                 }
 154 #ifdef RTE_KNI_PREEMPT_DEFAULT
 155                 schedule_timeout_interruptible(
 156                         usecs_to_jiffies(KNI_KTHREAD_RESCHEDULE_INTERVAL));
 157 #endif
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int
 164 kni_open(struct inode *inode, struct file *file)
 165 {
 166         struct net *net = current->nsproxy->net_ns;
 167         struct kni_net *knet = net_generic(net, kni_net_id);
 168
 169         /* kni device can be opened by one user only per netns */
 170         if (test_and_set_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use))
 171                 return -EBUSY;
 172
 173         file->private_data = get_net(net);
 174         pr_debug("/dev/kni opened\n");
 175
 176         return 0;
 177 }
 178
 179 static int
 180 kni_dev_remove(struct kni_dev *dev)
 181 {
 182         if (!dev)
 183                 return -ENODEV;
 184
 185 #ifdef RTE_KNI_KMOD_ETHTOOL
 186         if (dev->pci_dev) {
 187                 if (pci_match_id(ixgbe_pci_tbl, dev->pci_dev))
 188                         ixgbe_kni_remove(dev->pci_dev);
 189                 else if (pci_match_id(igb_pci_tbl, dev->pci_dev))
 190                         igb_kni_remove(dev->pci_dev);
 191         }
 192 #endif
 193
 194         if (dev->net_dev) {
 195                 unregister_netdev(dev->net_dev);
 196                 free_netdev(dev->net_dev);
 197         }
 198
 199         kni_net_release_fifo_phy(dev);
 200
 201         return 0;
 202 }
 203
 204 static int
 205 kni_release(struct inode *inode, struct file *file)
 206 {
 207         struct net *net = file->private_data;
 208         struct kni_net *knet = net_generic(net, kni_net_id);
 209         struct kni_dev *dev, *n;
 210
 211         /* Stop kernel thread for single mode */
 212         if (multiple_kthread_on == 0) {
 213                 mutex_lock(&knet->kni_kthread_lock);
 214                 /* Stop kernel thread */
 215                 if (knet->kni_kthread != NULL) {
 216                         kthread_stop(knet->kni_kthread);
 217                         knet->kni_kthread = NULL;
 218                 }
 219                 mutex_unlock(&knet->kni_kthread_lock);
 220         }
 221
 222         down_write(&knet->kni_list_lock);
 223         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 224                 /* Stop kernel thread for multiple mode */
 225                 if (multiple_kthread_on && dev->pthread != NULL) {
 226                         kthread_stop(dev->pthread);
 227                         dev->pthread = NULL;
 228                 }
 229
 230                 kni_dev_remove(dev);
 231                 list_del(&dev->list);
 232         }
 233         up_write(&knet->kni_list_lock);
 234
 235         /* Clear the bit of device in use */
 236         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
 237
 238         put_net(net);
 239         pr_debug("/dev/kni closed\n");
 240
 241         return 0;
 242 }
 243
 244 static int
 245 kni_check_param(struct kni_dev *kni, struct rte_kni_device_info *dev)
 246 {
 247         if (!kni || !dev)
 248                 return -1;
 249
 250         /* Check if network name has been used */
 251         if (!strncmp(kni->name, dev->name, RTE_KNI_NAMESIZE)) {
 252                 pr_err("KNI name %s duplicated\n", dev->name);
 253                 return -1;
 254         }
 255
 256         return 0;
 257 }
 258
 259 static int
 260 kni_run_thread(struct kni_net *knet, struct kni_dev *kni, uint8_t force_bind)
 261 {
 262         /**
 263          * Create a new kernel thread for multiple mode, set its core affinity,
 264          * and finally wake it up.
 265          */
 266         if (multiple_kthread_on) {
 267                 kni->pthread = kthread_create(kni_thread_multiple,
 268                         (void *)kni, "kni_%s", kni->name);
 269                 if (IS_ERR(kni->pthread)) {
 270                         kni_dev_remove(kni);
 271                         return -ECANCELED;
 272                 }
 273
 274                 if (force_bind)
 275                         kthread_bind(kni->pthread, kni->core_id);
 276                 wake_up_process(kni->pthread);
 277         } else {
 278                 mutex_lock(&knet->kni_kthread_lock);
 279
 280                 if (knet->kni_kthread == NULL) {
 281                         knet->kni_kthread = kthread_create(kni_thread_single,
 282                                 (void *)knet, "kni_single");
 283                         if (IS_ERR(knet->kni_kthread)) {
 284                                 mutex_unlock(&knet->kni_kthread_lock);
 285                                 kni_dev_remove(kni);
 286                                 return -ECANCELED;
 287                         }
 288
 289                         if (force_bind)
 290                                 kthread_bind(knet->kni_kthread, kni->core_id);
 291                         wake_up_process(knet->kni_kthread);
 292                 }
 293
 294                 mutex_unlock(&knet->kni_kthread_lock);
 295         }
 296
 297         return 0;
 298 }
 299
 300 static int
 301 kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 302                 unsigned long ioctl_param)
 303 {
 304         struct kni_net *knet = net_generic(net, kni_net_id);
 305         int ret;
 306         struct rte_kni_device_info dev_info;
 307         struct net_device *net_dev = NULL;
 308         struct kni_dev *kni, *dev, *n;
 309 #ifdef RTE_KNI_KMOD_ETHTOOL
 310         struct pci_dev *found_pci = NULL;
 311         struct net_device *lad_dev = NULL;
 312         struct pci_dev *pci = NULL;
 313 #endif
 314
 315         pr_info("Creating kni...\n");
 316         /* Check the buffer size, to avoid warning */
 317         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 318                 return -EINVAL;
 319
 320         /* Copy kni info from user space */
 321         ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
 322         if (ret) {
 323                 pr_err("copy_from_user in kni_ioctl_create");
 324                 return -EIO;
 325         }
 326
 327         /* Check if name is zero-ended */
 328         if (strnlen(dev_info.name, sizeof(dev_info.name)) == sizeof(dev_info.name)) {
 329                 pr_err("kni.name not zero-terminated");
 330                 return -EINVAL;
 331         }
 332
 333         /**
 334          * Check if the cpu core id is valid for binding.
 335          */
 336         if (dev_info.force_bind && !cpu_online(dev_info.core_id)) {
 337                 pr_err("cpu %u is not online\n", dev_info.core_id);
 338                 return -EINVAL;
 339         }
 340
 341         /* Check if it has been created */
 342         down_read(&knet->kni_list_lock);
 343         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 344                 if (kni_check_param(dev, &dev_info) < 0) {
 345                         up_read(&knet->kni_list_lock);
 346                         return -EINVAL;
 347                 }
 348         }
 349         up_read(&knet->kni_list_lock);
 350
 351         net_dev = alloc_netdev(sizeof(struct kni_dev), dev_info.name,
 352 #ifdef NET_NAME_USER
 353                                                         NET_NAME_USER,
 354 #endif
 355                                                         kni_net_init);
 356         if (net_dev == NULL) {
 357                 pr_err("error allocating device \"%s\"\n", dev_info.name);
 358                 return -EBUSY;
 359         }
 360
 361         dev_net_set(net_dev, net);
 362
 363         kni = netdev_priv(net_dev);
 364
 365         kni->net_dev = net_dev;
 366         kni->group_id = dev_info.group_id;
 367         kni->core_id = dev_info.core_id;
 368         strncpy(kni->name, dev_info.name, RTE_KNI_NAMESIZE);
 369
 370         /* Translate user space info into kernel space info */
 371         kni->tx_q = phys_to_virt(dev_info.tx_phys);
 372         kni->rx_q = phys_to_virt(dev_info.rx_phys);
 373         kni->alloc_q = phys_to_virt(dev_info.alloc_phys);
 374         kni->free_q = phys_to_virt(dev_info.free_phys);
 375
 376         kni->req_q = phys_to_virt(dev_info.req_phys);
 377         kni->resp_q = phys_to_virt(dev_info.resp_phys);
 378         kni->sync_va = dev_info.sync_va;
 379         kni->sync_kva = phys_to_virt(dev_info.sync_phys);
 380
 381         kni->mbuf_size = dev_info.mbuf_size;
 382
 383         pr_debug("tx_phys:      0x%016llx, tx_q addr:      0x%p\n",
 384                 (unsigned long long) dev_info.tx_phys, kni->tx_q);
 385         pr_debug("rx_phys:      0x%016llx, rx_q addr:      0x%p\n",
 386                 (unsigned long long) dev_info.rx_phys, kni->rx_q);
 387         pr_debug("alloc_phys:   0x%016llx, alloc_q addr:   0x%p\n",
 388                 (unsigned long long) dev_info.alloc_phys, kni->alloc_q);
 389         pr_debug("free_phys:    0x%016llx, free_q addr:    0x%p\n",
 390                 (unsigned long long) dev_info.free_phys, kni->free_q);
 391         pr_debug("req_phys:     0x%016llx, req_q addr:     0x%p\n",
 392                 (unsigned long long) dev_info.req_phys, kni->req_q);
 393         pr_debug("resp_phys:    0x%016llx, resp_q addr:    0x%p\n",
 394                 (unsigned long long) dev_info.resp_phys, kni->resp_q);
 395         pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 396
 397         pr_debug("PCI: %02x:%02x.%02x %04x:%04x\n",
 398                                         dev_info.bus,
 399                                         dev_info.devid,
 400                                         dev_info.function,
 401                                         dev_info.vendor_id,
 402                                         dev_info.device_id);
 403 #ifdef RTE_KNI_KMOD_ETHTOOL
 404         pci = pci_get_device(dev_info.vendor_id, dev_info.device_id, NULL);
 405
 406         /* Support Ethtool */
 407         while (pci) {
 408                 pr_debug("pci_bus: %02x:%02x:%02x\n",
 409                                         pci->bus->number,
 410                                         PCI_SLOT(pci->devfn),
 411                                         PCI_FUNC(pci->devfn));
 412
 413                 if ((pci->bus->number == dev_info.bus) &&
 414                         (PCI_SLOT(pci->devfn) == dev_info.devid) &&
 415                         (PCI_FUNC(pci->devfn) == dev_info.function)) {
 416                         found_pci = pci;
 417
 418                         if (pci_match_id(ixgbe_pci_tbl, found_pci))
 419                                 ret = ixgbe_kni_probe(found_pci, &lad_dev);
 420                         else if (pci_match_id(igb_pci_tbl, found_pci))
 421                                 ret = igb_kni_probe(found_pci, &lad_dev);
 422                         else
 423                                 ret = -1;
 424
 425                         pr_debug("PCI found: pci=0x%p, lad_dev=0x%p\n",
 426                                                         pci, lad_dev);
 427                         if (ret == 0) {
 428                                 kni->lad_dev = lad_dev;
 429                                 kni_set_ethtool_ops(kni->net_dev);
 430                         } else {
 431                                 pr_err("Device not supported by ethtool");
 432                                 kni->lad_dev = NULL;
 433                         }
 434
 435                         kni->pci_dev = found_pci;
 436                         kni->device_id = dev_info.device_id;
 437                         break;
 438                 }
 439                 pci = pci_get_device(dev_info.vendor_id,
 440                                 dev_info.device_id, pci);
 441         }
 442         if (pci)
 443                 pci_dev_put(pci);
 444 #endif
 445
 446         if (kni->lad_dev)
 447                 ether_addr_copy(net_dev->dev_addr, kni->lad_dev->dev_addr);
 448         else {
 449                 /* if user has provided a valid mac address */
 450                 if (is_valid_ether_addr(dev_info.mac_addr))
 451                         memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
 452                 else
 453                         /*
 454                          * Generate random mac address. eth_random_addr() is the
 455                          * newer version of generating mac address in kernel.
 456                          */
 457                         random_ether_addr(net_dev->dev_addr);
 458         }
 459
 460         if (dev_info.mtu)
 461                 net_dev->mtu = dev_info.mtu;
 462 #ifdef HAVE_MAX_MTU_PARAM
 463         net_dev->max_mtu = net_dev->mtu;
 464 #endif
 465
 466         ret = register_netdev(net_dev);
 467         if (ret) {
 468                 pr_err("error %i registering device \"%s\"\n",
 469                                         ret, dev_info.name);
 470                 kni->net_dev = NULL;
 471                 kni_dev_remove(kni);
 472                 free_netdev(net_dev);
 473                 return -ENODEV;
 474         }
 475
 476         netif_carrier_off(net_dev);
 477
 478         ret = kni_run_thread(knet, kni, dev_info.force_bind);
 479         if (ret != 0)
 480                 return ret;
 481
 482         down_write(&knet->kni_list_lock);
 483         list_add(&kni->list, &knet->kni_list_head);
 484         up_write(&knet->kni_list_lock);
 485
 486         return 0;
 487 }
 488
 489 static int
 490 kni_ioctl_release(struct net *net, uint32_t ioctl_num,
 491                 unsigned long ioctl_param)
 492 {
 493         struct kni_net *knet = net_generic(net, kni_net_id);
 494         int ret = -EINVAL;
 495         struct kni_dev *dev, *n;
 496         struct rte_kni_device_info dev_info;
 497
 498         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 499                 return -EINVAL;
 500
 501         ret = copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info));
 502         if (ret) {
 503                 pr_err("copy_from_user in kni_ioctl_release");
 504                 return -EIO;
 505         }
 506
 507         /* Release the network device according to its name */
 508         if (strlen(dev_info.name) == 0)
 509                 return ret;
 510
 511         down_write(&knet->kni_list_lock);
 512         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 513                 if (strncmp(dev->name, dev_info.name, RTE_KNI_NAMESIZE) != 0)
 514                         continue;
 515
 516                 if (multiple_kthread_on && dev->pthread != NULL) {
 517                         kthread_stop(dev->pthread);
 518                         dev->pthread = NULL;
 519                 }
 520
 521                 kni_dev_remove(dev);
 522                 list_del(&dev->list);
 523                 ret = 0;
 524                 break;
 525         }
 526         up_write(&knet->kni_list_lock);
 527         pr_info("%s release kni named %s\n",
 528                 (ret == 0 ? "Successfully" : "Unsuccessfully"), dev_info.name);
 529
 530         return ret;
 531 }
 532
 533 static int
 534 kni_ioctl(struct inode *inode, uint32_t ioctl_num, unsigned long ioctl_param)
 535 {
 536         int ret = -EINVAL;
 537         struct net *net = current->nsproxy->net_ns;
 538
 539         pr_debug("IOCTL num=0x%0x param=0x%0lx\n", ioctl_num, ioctl_param);
 540
 541         /*
 542          * Switch according to the ioctl called
 543          */
 544         switch (_IOC_NR(ioctl_num)) {
 545         case _IOC_NR(RTE_KNI_IOCTL_TEST):
 546                 /* For test only, not used */
 547                 break;
 548         case _IOC_NR(RTE_KNI_IOCTL_CREATE):
 549                 ret = kni_ioctl_create(net, ioctl_num, ioctl_param);
 550                 break;
 551         case _IOC_NR(RTE_KNI_IOCTL_RELEASE):
 552                 ret = kni_ioctl_release(net, ioctl_num, ioctl_param);
 553                 break;
 554         default:
 555                 pr_debug("IOCTL default\n");
 556                 break;
 557         }
 558
 559         return ret;
 560 }
 561
 562 static int
 563 kni_compat_ioctl(struct inode *inode, uint32_t ioctl_num,
 564                 unsigned long ioctl_param)
 565 {
 566         /* 32 bits app on 64 bits OS to be supported later */
 567         pr_debug("Not implemented.\n");
 568
 569         return -EINVAL;
 570 }
 571
 572 static const struct file_operations kni_fops = {
 573         .owner = THIS_MODULE,
 574         .open = kni_open,
 575         .release = kni_release,
 576         .unlocked_ioctl = (void *)kni_ioctl,
 577         .compat_ioctl = (void *)kni_compat_ioctl,
 578 };
 579
 580 static struct miscdevice kni_misc = {
 581         .minor = MISC_DYNAMIC_MINOR,
 582         .name = KNI_DEVICE,
 583         .fops = &kni_fops,
 584 };
 585
 586 static int __init
 587 kni_parse_kthread_mode(void)
 588 {
 589         if (!kthread_mode)
 590                 return 0;
 591
 592         if (strcmp(kthread_mode, "single") == 0)
 593                 return 0;
 594         else if (strcmp(kthread_mode, "multiple") == 0)
 595                 multiple_kthread_on = 1;
 596         else
 597                 return -1;
 598
 599         return 0;
 600 }
 601
 602 static int __init
 603 kni_parse_carrier_state(void)
 604 {
 605         if (!carrier) {
 606                 dflt_carrier = 0;
 607                 return 0;
 608         }
 609
 610         if (strcmp(carrier, "off") == 0)
 611                 dflt_carrier = 0;
 612         else if (strcmp(carrier, "on") == 0)
 613                 dflt_carrier = 1;
 614         else
 615                 return -1;
 616
 617         return 0;
 618 }
 619
 620 static int __init
 621 kni_init(void)
 622 {
 623         int rc;
 624
 625         if (kni_parse_kthread_mode() < 0) {
 626                 pr_err("Invalid parameter for kthread_mode\n");
 627                 return -EINVAL;
 628         }
 629
 630         if (multiple_kthread_on == 0)
 631                 pr_debug("Single kernel thread for all KNI devices\n");
 632         else
 633                 pr_debug("Multiple kernel thread mode enabled\n");
 634
 635         if (kni_parse_carrier_state() < 0) {
 636                 pr_err("Invalid parameter for carrier\n");
 637                 return -EINVAL;
 638         }
 639
 640         if (dflt_carrier == 0)
 641                 pr_debug("Default carrier state set to off.\n");
 642         else
 643                 pr_debug("Default carrier state set to on.\n");
 644
 645 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 646         rc = register_pernet_subsys(&kni_net_ops);
 647 #else
 648         rc = register_pernet_gen_subsys(&kni_net_id, &kni_net_ops);
 649 #endif
 650         if (rc)
 651                 return -EPERM;
 652
 653         rc = misc_register(&kni_misc);
 654         if (rc != 0) {
 655                 pr_err("Misc registration failed\n");
 656                 goto out;
 657         }
 658
 659         /* Configure the lo mode according to the input parameter */
 660         kni_net_config_lo_mode(lo_mode);
 661
 662         return 0;
 663
 664 out:
 665 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 666         unregister_pernet_subsys(&kni_net_ops);
 667 #else
 668         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 669 #endif
 670         return rc;
 671 }
 672
 673 static void __exit
 674 kni_exit(void)
 675 {
 676         misc_deregister(&kni_misc);
 677 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 678         unregister_pernet_subsys(&kni_net_ops);
 679 #else
 680         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 681 #endif
 682 }
 683
 684 module_init(kni_init);
 685 module_exit(kni_exit);
 686
 687 module_param(lo_mode, charp, 0644);
 688 MODULE_PARM_DESC(lo_mode,
 689 "KNI loopback mode (default=lo_mode_none):\n"
 690 "\t\tlo_mode_none        Kernel loopback disabled\n"
 691 "\t\tlo_mode_fifo        Enable kernel loopback with fifo\n"
 692 "\t\tlo_mode_fifo_skb    Enable kernel loopback with fifo and skb buffer\n"
 693 "\t\t"
 694 );
 695
 696 module_param(kthread_mode, charp, 0644);
 697 MODULE_PARM_DESC(kthread_mode,
 698 "Kernel thread mode (default=single):\n"
 699 "\t\tsingle    Single kernel thread mode enabled.\n"
 700 "\t\tmultiple  Multiple kernel thread mode enabled.\n"
 701 "\t\t"
 702 );
 703
 704 module_param(carrier, charp, 0644);
 705 MODULE_PARM_DESC(carrier,
 706 "Default carrier state for KNI interface (default=off):\n"
 707 "\t\toff   Interfaces will be created with carrier state set to off.\n"
 708 "\t\ton    Interfaces will be created with carrier state set to on.\n"
 709 "\t\t"
 710 );