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_VERSION(KNI_VERSION);
  25 MODULE_LICENSE("Dual BSD/GPL");
  26 MODULE_AUTHOR("Intel Corporation");
  27 MODULE_DESCRIPTION("Kernel Module for managing kni devices");
  28
  29 #define KNI_RX_LOOP_NUM 1000
  30
  31 #define KNI_MAX_DEVICES 32
  32
  33 /* loopback mode */
  34 static char *lo_mode;
  35
  36 /* Kernel thread mode */
  37 static char *kthread_mode;
  38 static uint32_t multiple_kthread_on;
  39
  40 /* Default carrier state for created KNI network interfaces */
  41 static char *carrier;
  42 uint32_t kni_dflt_carrier;
  43
  44 /* Request processing support for bifurcated drivers. */
  45 static char *enable_bifurcated;
  46 uint32_t bifurcated_support;
  47
  48 /* KNI thread scheduling interval */
  49 static long min_scheduling_interval = 100; /* us */
  50 static long max_scheduling_interval = 200; /* us */
  51
  52 #define KNI_DEV_IN_USE_BIT_NUM 0 /* Bit number for device in use */
  53
  54 static int kni_net_id;
  55
  56 struct kni_net {
  57         unsigned long device_in_use; /* device in use flag */
  58         struct mutex kni_kthread_lock;
  59         struct task_struct *kni_kthread;
  60         struct rw_semaphore kni_list_lock;
  61         struct list_head kni_list_head;
  62 };
  63
  64 static int __net_init
  65 kni_init_net(struct net *net)
  66 {
  67 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
  68         struct kni_net *knet = net_generic(net, kni_net_id);
  69
  70         memset(knet, 0, sizeof(*knet));
  71 #else
  72         struct kni_net *knet;
  73         int ret;
  74
  75         knet = kzalloc(sizeof(struct kni_net), GFP_KERNEL);
  76         if (!knet) {
  77                 ret = -ENOMEM;
  78                 return ret;
  79         }
  80 #endif
  81
  82         /* Clear the bit of device in use */
  83         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
  84
  85         mutex_init(&knet->kni_kthread_lock);
  86
  87         init_rwsem(&knet->kni_list_lock);
  88         INIT_LIST_HEAD(&knet->kni_list_head);
  89
  90 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
  91         return 0;
  92 #else
  93         ret = net_assign_generic(net, kni_net_id, knet);
  94         if (ret < 0)
  95                 kfree(knet);
  96
  97         return ret;
  98 #endif
  99 }
 100
 101 static void __net_exit
 102 kni_exit_net(struct net *net)
 103 {
 104         struct kni_net *knet __maybe_unused;
 105
 106         knet = net_generic(net, kni_net_id);
 107         mutex_destroy(&knet->kni_kthread_lock);
 108
 109 #ifndef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 110         kfree(knet);
 111 #endif
 112 }
 113
 114 static struct pernet_operations kni_net_ops = {
 115         .init = kni_init_net,
 116         .exit = kni_exit_net,
 117 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 118         .id   = &kni_net_id,
 119         .size = sizeof(struct kni_net),
 120 #endif
 121 };
 122
 123 static int
 124 kni_thread_single(void *data)
 125 {
 126         struct kni_net *knet = data;
 127         int j;
 128         struct kni_dev *dev;
 129
 130         while (!kthread_should_stop()) {
 131                 down_read(&knet->kni_list_lock);
 132                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 133                         list_for_each_entry(dev, &knet->kni_list_head, list) {
 134                                 kni_net_rx(dev);
 135                                 kni_net_poll_resp(dev);
 136                         }
 137                 }
 138                 up_read(&knet->kni_list_lock);
 139                 /* reschedule out for a while */
 140                 usleep_range(min_scheduling_interval, max_scheduling_interval);
 141         }
 142
 143         return 0;
 144 }
 145
 146 static int
 147 kni_thread_multiple(void *param)
 148 {
 149         int j;
 150         struct kni_dev *dev = param;
 151
 152         while (!kthread_should_stop()) {
 153                 for (j = 0; j < KNI_RX_LOOP_NUM; j++) {
 154                         kni_net_rx(dev);
 155                         kni_net_poll_resp(dev);
 156                 }
 157                 usleep_range(min_scheduling_interval, max_scheduling_interval);
 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         /*
 186          * The memory of kni device is allocated and released together
 187          * with net device. Release mbuf before freeing net device.
 188          */
 189         kni_net_release_fifo_phy(dev);
 190
 191         if (dev->net_dev) {
 192                 unregister_netdev(dev->net_dev);
 193                 free_netdev(dev->net_dev);
 194         }
 195
 196         return 0;
 197 }
 198
 199 static int
 200 kni_release(struct inode *inode, struct file *file)
 201 {
 202         struct net *net = file->private_data;
 203         struct kni_net *knet = net_generic(net, kni_net_id);
 204         struct kni_dev *dev, *n;
 205
 206         /* Stop kernel thread for single mode */
 207         if (multiple_kthread_on == 0) {
 208                 mutex_lock(&knet->kni_kthread_lock);
 209                 /* Stop kernel thread */
 210                 if (knet->kni_kthread != NULL) {
 211                         kthread_stop(knet->kni_kthread);
 212                         knet->kni_kthread = NULL;
 213                 }
 214                 mutex_unlock(&knet->kni_kthread_lock);
 215         }
 216
 217         down_write(&knet->kni_list_lock);
 218         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 219                 /* Stop kernel thread for multiple mode */
 220                 if (multiple_kthread_on && dev->pthread != NULL) {
 221                         kthread_stop(dev->pthread);
 222                         dev->pthread = NULL;
 223                 }
 224
 225                 list_del(&dev->list);
 226                 kni_dev_remove(dev);
 227         }
 228         up_write(&knet->kni_list_lock);
 229
 230         /* Clear the bit of device in use */
 231         clear_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use);
 232
 233         put_net(net);
 234         pr_debug("/dev/kni closed\n");
 235
 236         return 0;
 237 }
 238
 239 static int
 240 kni_check_param(struct kni_dev *kni, struct rte_kni_device_info *dev)
 241 {
 242         if (!kni || !dev)
 243                 return -1;
 244
 245         /* Check if network name has been used */
 246         if (!strncmp(kni->name, dev->name, RTE_KNI_NAMESIZE)) {
 247                 pr_err("KNI name %s duplicated\n", dev->name);
 248                 return -1;
 249         }
 250
 251         return 0;
 252 }
 253
 254 static int
 255 kni_run_thread(struct kni_net *knet, struct kni_dev *kni, uint8_t force_bind)
 256 {
 257         /**
 258          * Create a new kernel thread for multiple mode, set its core affinity,
 259          * and finally wake it up.
 260          */
 261         if (multiple_kthread_on) {
 262                 kni->pthread = kthread_create(kni_thread_multiple,
 263                         (void *)kni, "kni_%s", kni->name);
 264                 if (IS_ERR(kni->pthread)) {
 265                         kni_dev_remove(kni);
 266                         return -ECANCELED;
 267                 }
 268
 269                 if (force_bind)
 270                         kthread_bind(kni->pthread, kni->core_id);
 271                 wake_up_process(kni->pthread);
 272         } else {
 273                 mutex_lock(&knet->kni_kthread_lock);
 274
 275                 if (knet->kni_kthread == NULL) {
 276                         knet->kni_kthread = kthread_create(kni_thread_single,
 277                                 (void *)knet, "kni_single");
 278                         if (IS_ERR(knet->kni_kthread)) {
 279                                 mutex_unlock(&knet->kni_kthread_lock);
 280                                 kni_dev_remove(kni);
 281                                 return -ECANCELED;
 282                         }
 283
 284                         if (force_bind)
 285                                 kthread_bind(knet->kni_kthread, kni->core_id);
 286                         wake_up_process(knet->kni_kthread);
 287                 }
 288
 289                 mutex_unlock(&knet->kni_kthread_lock);
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int
 296 kni_ioctl_create(struct net *net, uint32_t ioctl_num,
 297                 unsigned long ioctl_param)
 298 {
 299         struct kni_net *knet = net_generic(net, kni_net_id);
 300         int ret;
 301         struct rte_kni_device_info dev_info;
 302         struct net_device *net_dev = NULL;
 303         struct kni_dev *kni, *dev, *n;
 304
 305         pr_info("Creating kni...\n");
 306         /* Check the buffer size, to avoid warning */
 307         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 308                 return -EINVAL;
 309
 310         /* Copy kni info from user space */
 311         if (copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info)))
 312                 return -EFAULT;
 313
 314         /* Check if name is zero-ended */
 315         if (strnlen(dev_info.name, sizeof(dev_info.name)) == sizeof(dev_info.name)) {
 316                 pr_err("kni.name not zero-terminated");
 317                 return -EINVAL;
 318         }
 319
 320         /**
 321          * Check if the cpu core id is valid for binding.
 322          */
 323         if (dev_info.force_bind && !cpu_online(dev_info.core_id)) {
 324                 pr_err("cpu %u is not online\n", dev_info.core_id);
 325                 return -EINVAL;
 326         }
 327
 328         /* Check if it has been created */
 329         down_read(&knet->kni_list_lock);
 330         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 331                 if (kni_check_param(dev, &dev_info) < 0) {
 332                         up_read(&knet->kni_list_lock);
 333                         return -EINVAL;
 334                 }
 335         }
 336         up_read(&knet->kni_list_lock);
 337
 338         net_dev = alloc_netdev(sizeof(struct kni_dev), dev_info.name,
 339 #ifdef NET_NAME_USER
 340                                                         NET_NAME_USER,
 341 #endif
 342                                                         kni_net_init);
 343         if (net_dev == NULL) {
 344                 pr_err("error allocating device \"%s\"\n", dev_info.name);
 345                 return -EBUSY;
 346         }
 347
 348         dev_net_set(net_dev, net);
 349
 350         kni = netdev_priv(net_dev);
 351
 352         kni->net_dev = net_dev;
 353         kni->core_id = dev_info.core_id;
 354         strncpy(kni->name, dev_info.name, RTE_KNI_NAMESIZE);
 355
 356         /* Translate user space info into kernel space info */
 357         if (dev_info.iova_mode) {
 358 #ifdef HAVE_IOVA_TO_KVA_MAPPING_SUPPORT
 359                 kni->tx_q = iova_to_kva(current, dev_info.tx_phys);
 360                 kni->rx_q = iova_to_kva(current, dev_info.rx_phys);
 361                 kni->alloc_q = iova_to_kva(current, dev_info.alloc_phys);
 362                 kni->free_q = iova_to_kva(current, dev_info.free_phys);
 363
 364                 kni->req_q = iova_to_kva(current, dev_info.req_phys);
 365                 kni->resp_q = iova_to_kva(current, dev_info.resp_phys);
 366                 kni->sync_va = dev_info.sync_va;
 367                 kni->sync_kva = iova_to_kva(current, dev_info.sync_phys);
 368                 kni->usr_tsk = current;
 369                 kni->iova_mode = 1;
 370 #else
 371                 pr_err("KNI module does not support IOVA to VA translation\n");
 372                 return -EINVAL;
 373 #endif
 374         } else {
 375
 376                 kni->tx_q = phys_to_virt(dev_info.tx_phys);
 377                 kni->rx_q = phys_to_virt(dev_info.rx_phys);
 378                 kni->alloc_q = phys_to_virt(dev_info.alloc_phys);
 379                 kni->free_q = phys_to_virt(dev_info.free_phys);
 380
 381                 kni->req_q = phys_to_virt(dev_info.req_phys);
 382                 kni->resp_q = phys_to_virt(dev_info.resp_phys);
 383                 kni->sync_va = dev_info.sync_va;
 384                 kni->sync_kva = phys_to_virt(dev_info.sync_phys);
 385                 kni->iova_mode = 0;
 386         }
 387
 388         kni->mbuf_size = dev_info.mbuf_size;
 389
 390         pr_debug("tx_phys:      0x%016llx, tx_q addr:      0x%p\n",
 391                 (unsigned long long) dev_info.tx_phys, kni->tx_q);
 392         pr_debug("rx_phys:      0x%016llx, rx_q addr:      0x%p\n",
 393                 (unsigned long long) dev_info.rx_phys, kni->rx_q);
 394         pr_debug("alloc_phys:   0x%016llx, alloc_q addr:   0x%p\n",
 395                 (unsigned long long) dev_info.alloc_phys, kni->alloc_q);
 396         pr_debug("free_phys:    0x%016llx, free_q addr:    0x%p\n",
 397                 (unsigned long long) dev_info.free_phys, kni->free_q);
 398         pr_debug("req_phys:     0x%016llx, req_q addr:     0x%p\n",
 399                 (unsigned long long) dev_info.req_phys, kni->req_q);
 400         pr_debug("resp_phys:    0x%016llx, resp_q addr:    0x%p\n",
 401                 (unsigned long long) dev_info.resp_phys, kni->resp_q);
 402         pr_debug("mbuf_size:    %u\n", kni->mbuf_size);
 403
 404         /* if user has provided a valid mac address */
 405         if (is_valid_ether_addr(dev_info.mac_addr))
 406                 memcpy(net_dev->dev_addr, dev_info.mac_addr, ETH_ALEN);
 407         else
 408                 /* Generate random MAC address. */
 409                 eth_random_addr(net_dev->dev_addr);
 410
 411         if (dev_info.mtu)
 412                 net_dev->mtu = dev_info.mtu;
 413 #ifdef HAVE_MAX_MTU_PARAM
 414         net_dev->max_mtu = net_dev->mtu;
 415
 416         if (dev_info.min_mtu)
 417                 net_dev->min_mtu = dev_info.min_mtu;
 418
 419         if (dev_info.max_mtu)
 420                 net_dev->max_mtu = dev_info.max_mtu;
 421 #endif
 422
 423         ret = register_netdev(net_dev);
 424         if (ret) {
 425                 pr_err("error %i registering device \"%s\"\n",
 426                                         ret, dev_info.name);
 427                 kni->net_dev = NULL;
 428                 kni_dev_remove(kni);
 429                 free_netdev(net_dev);
 430                 return -ENODEV;
 431         }
 432
 433         netif_carrier_off(net_dev);
 434
 435         ret = kni_run_thread(knet, kni, dev_info.force_bind);
 436         if (ret != 0)
 437                 return ret;
 438
 439         down_write(&knet->kni_list_lock);
 440         list_add(&kni->list, &knet->kni_list_head);
 441         up_write(&knet->kni_list_lock);
 442
 443         return 0;
 444 }
 445
 446 static int
 447 kni_ioctl_release(struct net *net, uint32_t ioctl_num,
 448                 unsigned long ioctl_param)
 449 {
 450         struct kni_net *knet = net_generic(net, kni_net_id);
 451         int ret = -EINVAL;
 452         struct kni_dev *dev, *n;
 453         struct rte_kni_device_info dev_info;
 454
 455         if (_IOC_SIZE(ioctl_num) > sizeof(dev_info))
 456                 return -EINVAL;
 457
 458         if (copy_from_user(&dev_info, (void *)ioctl_param, sizeof(dev_info)))
 459                 return -EFAULT;
 460
 461         /* Release the network device according to its name */
 462         if (strlen(dev_info.name) == 0)
 463                 return -EINVAL;
 464
 465         down_write(&knet->kni_list_lock);
 466         list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
 467                 if (strncmp(dev->name, dev_info.name, RTE_KNI_NAMESIZE) != 0)
 468                         continue;
 469
 470                 if (multiple_kthread_on && dev->pthread != NULL) {
 471                         kthread_stop(dev->pthread);
 472                         dev->pthread = NULL;
 473                 }
 474
 475                 list_del(&dev->list);
 476                 kni_dev_remove(dev);
 477                 ret = 0;
 478                 break;
 479         }
 480         up_write(&knet->kni_list_lock);
 481         pr_info("%s release kni named %s\n",
 482                 (ret == 0 ? "Successfully" : "Unsuccessfully"), dev_info.name);
 483
 484         return ret;
 485 }
 486
 487 static long
 488 kni_ioctl(struct file *file, unsigned int ioctl_num, unsigned long ioctl_param)
 489 {
 490         long ret = -EINVAL;
 491         struct net *net = current->nsproxy->net_ns;
 492
 493         pr_debug("IOCTL num=0x%0x param=0x%0lx\n", ioctl_num, ioctl_param);
 494
 495         /*
 496          * Switch according to the ioctl called
 497          */
 498         switch (_IOC_NR(ioctl_num)) {
 499         case _IOC_NR(RTE_KNI_IOCTL_TEST):
 500                 /* For test only, not used */
 501                 break;
 502         case _IOC_NR(RTE_KNI_IOCTL_CREATE):
 503                 ret = kni_ioctl_create(net, ioctl_num, ioctl_param);
 504                 break;
 505         case _IOC_NR(RTE_KNI_IOCTL_RELEASE):
 506                 ret = kni_ioctl_release(net, ioctl_num, ioctl_param);
 507                 break;
 508         default:
 509                 pr_debug("IOCTL default\n");
 510                 break;
 511         }
 512
 513         return ret;
 514 }
 515
 516 static long
 517 kni_compat_ioctl(struct file *file, unsigned int ioctl_num,
 518                 unsigned long ioctl_param)
 519 {
 520         /* 32 bits app on 64 bits OS to be supported later */
 521         pr_debug("Not implemented.\n");
 522
 523         return -EINVAL;
 524 }
 525
 526 static const struct file_operations kni_fops = {
 527         .owner = THIS_MODULE,
 528         .open = kni_open,
 529         .release = kni_release,
 530         .unlocked_ioctl = kni_ioctl,
 531         .compat_ioctl = kni_compat_ioctl,
 532 };
 533
 534 static struct miscdevice kni_misc = {
 535         .minor = MISC_DYNAMIC_MINOR,
 536         .name = KNI_DEVICE,
 537         .fops = &kni_fops,
 538 };
 539
 540 static int __init
 541 kni_parse_kthread_mode(void)
 542 {
 543         if (!kthread_mode)
 544                 return 0;
 545
 546         if (strcmp(kthread_mode, "single") == 0)
 547                 return 0;
 548         else if (strcmp(kthread_mode, "multiple") == 0)
 549                 multiple_kthread_on = 1;
 550         else
 551                 return -1;
 552
 553         return 0;
 554 }
 555
 556 static int __init
 557 kni_parse_carrier_state(void)
 558 {
 559         if (!carrier) {
 560                 kni_dflt_carrier = 0;
 561                 return 0;
 562         }
 563
 564         if (strcmp(carrier, "off") == 0)
 565                 kni_dflt_carrier = 0;
 566         else if (strcmp(carrier, "on") == 0)
 567                 kni_dflt_carrier = 1;
 568         else
 569                 return -1;
 570
 571         return 0;
 572 }
 573
 574 static int __init
 575 kni_parse_bifurcated_support(void)
 576 {
 577         if (!enable_bifurcated) {
 578                 bifurcated_support = 0;
 579                 return 0;
 580         }
 581
 582         if (strcmp(enable_bifurcated, "on") == 0)
 583                 bifurcated_support = 1;
 584         else
 585                 return -1;
 586
 587         return 0;
 588 }
 589
 590 static int __init
 591 kni_init(void)
 592 {
 593         int rc;
 594
 595         if (kni_parse_kthread_mode() < 0) {
 596                 pr_err("Invalid parameter for kthread_mode\n");
 597                 return -EINVAL;
 598         }
 599
 600         if (multiple_kthread_on == 0)
 601                 pr_debug("Single kernel thread for all KNI devices\n");
 602         else
 603                 pr_debug("Multiple kernel thread mode enabled\n");
 604
 605         if (kni_parse_carrier_state() < 0) {
 606                 pr_err("Invalid parameter for carrier\n");
 607                 return -EINVAL;
 608         }
 609
 610         if (kni_dflt_carrier == 0)
 611                 pr_debug("Default carrier state set to off.\n");
 612         else
 613                 pr_debug("Default carrier state set to on.\n");
 614
 615         if (kni_parse_bifurcated_support() < 0) {
 616                 pr_err("Invalid parameter for bifurcated support\n");
 617                 return -EINVAL;
 618         }
 619         if (bifurcated_support == 1)
 620                 pr_debug("bifurcated support is enabled.\n");
 621
 622         if (min_scheduling_interval < 0 || max_scheduling_interval < 0 ||
 623                 min_scheduling_interval > KNI_KTHREAD_MAX_RESCHEDULE_INTERVAL ||
 624                 max_scheduling_interval > KNI_KTHREAD_MAX_RESCHEDULE_INTERVAL ||
 625                 min_scheduling_interval >= max_scheduling_interval) {
 626                 pr_err("Invalid parameters for scheduling interval\n");
 627                 return -EINVAL;
 628         }
 629
 630 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 631         rc = register_pernet_subsys(&kni_net_ops);
 632 #else
 633         rc = register_pernet_gen_subsys(&kni_net_id, &kni_net_ops);
 634 #endif
 635         if (rc)
 636                 return -EPERM;
 637
 638         rc = misc_register(&kni_misc);
 639         if (rc != 0) {
 640                 pr_err("Misc registration failed\n");
 641                 goto out;
 642         }
 643
 644         /* Configure the lo mode according to the input parameter */
 645         kni_net_config_lo_mode(lo_mode);
 646
 647         return 0;
 648
 649 out:
 650 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 651         unregister_pernet_subsys(&kni_net_ops);
 652 #else
 653         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 654 #endif
 655         return rc;
 656 }
 657
 658 static void __exit
 659 kni_exit(void)
 660 {
 661         misc_deregister(&kni_misc);
 662 #ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
 663         unregister_pernet_subsys(&kni_net_ops);
 664 #else
 665         unregister_pernet_gen_subsys(kni_net_id, &kni_net_ops);
 666 #endif
 667 }
 668
 669 module_init(kni_init);
 670 module_exit(kni_exit);
 671
 672 module_param(lo_mode, charp, 0644);
 673 MODULE_PARM_DESC(lo_mode,
 674 "KNI loopback mode (default=lo_mode_none):\n"
 675 "\t\tlo_mode_none        Kernel loopback disabled\n"
 676 "\t\tlo_mode_fifo        Enable kernel loopback with fifo\n"
 677 "\t\tlo_mode_fifo_skb    Enable kernel loopback with fifo and skb buffer\n"
 678 "\t\t"
 679 );
 680
 681 module_param(kthread_mode, charp, 0644);
 682 MODULE_PARM_DESC(kthread_mode,
 683 "Kernel thread mode (default=single):\n"
 684 "\t\tsingle    Single kernel thread mode enabled.\n"
 685 "\t\tmultiple  Multiple kernel thread mode enabled.\n"
 686 "\t\t"
 687 );
 688
 689 module_param(carrier, charp, 0644);
 690 MODULE_PARM_DESC(carrier,
 691 "Default carrier state for KNI interface (default=off):\n"
 692 "\t\toff   Interfaces will be created with carrier state set to off.\n"
 693 "\t\ton    Interfaces will be created with carrier state set to on.\n"
 694 "\t\t"
 695 );
 696
 697 module_param(enable_bifurcated, charp, 0644);
 698 MODULE_PARM_DESC(enable_bifurcated,
 699 "Enable request processing support for bifurcated drivers, "
 700 "which means releasing rtnl_lock before calling userspace callback and "
 701 "supporting async requests (default=off):\n"
 702 "\t\ton    Enable request processing support for bifurcated drivers.\n"
 703 "\t\t"
 704 );
 705
 706 module_param(min_scheduling_interval, long, 0644);
 707 MODULE_PARM_DESC(min_scheduling_interval,
 708 "KNI thread min scheduling interval (default=100 microseconds)"
 709 );
 710
 711 module_param(max_scheduling_interval, long, 0644);
 712 MODULE_PARM_DESC(max_scheduling_interval,
 713 "KNI thread max scheduling interval (default=200 microseconds)"
 714 );