drivers/staging/hv/netvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/highmem.h>
  24 #include <linux/device.h>
  25 #include <linux/io.h>
  26 #include <linux/delay.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/inetdevice.h>
  29 #include <linux/etherdevice.h>
  30 #include <linux/skbuff.h>
  31 #include <linux/in.h>
  32 #include <net/arp.h>
  33 #include <net/route.h>
  34 #include <net/sock.h>
  35 #include <net/pkt_sched.h>
  36 #include "osd.h"
  37 #include "logging.h"
  38 #include "vmbus.h"
  39 #include "NetVscApi.h"
  40
  41 MODULE_LICENSE("GPL");
  42
  43 struct net_device_context {
  44         /* point back to our device context */
  45         struct device_context *device_ctx;
  46         struct net_device_stats stats;
  47         struct work_struct work;
  48 };
  49
  50 struct netvsc_driver_context {
  51         /* !! These must be the first 2 fields !! */
  52         /* Which is a bug FIXME! */
  53         struct driver_context drv_ctx;
  54         struct netvsc_driver drv_obj;
  55 };
  56
  57 static int netvsc_ringbuffer_size = NETVSC_DEVICE_RING_BUFFER_SIZE;
  58
  59 /* The one and only one */
  60 static struct netvsc_driver_context g_netvsc_drv;
  61
  62 static struct net_device_stats *netvsc_get_stats(struct net_device *net)
  63 {
  64         struct net_device_context *net_device_ctx = netdev_priv(net);
  65
  66         return &net_device_ctx->stats;
  67 }
  68
  69 static void netvsc_set_multicast_list(struct net_device *net)
  70 {
  71 }
  72
  73 static int netvsc_open(struct net_device *net)
  74 {
  75         struct net_device_context *net_device_ctx = netdev_priv(net);
  76         struct driver_context *driver_ctx =
  77             driver_to_driver_context(net_device_ctx->device_ctx->device.driver);
  78         struct netvsc_driver_context *net_drv_ctx =
  79                 (struct netvsc_driver_context *)driver_ctx;
  80         struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
  81         struct hv_device *device_obj = &net_device_ctx->device_ctx->device_obj;
  82         int ret = 0;
  83
  84         DPRINT_ENTER(NETVSC_DRV);
  85
  86         if (netif_carrier_ok(net)) {
  87                 memset(&net_device_ctx->stats, 0,
  88                        sizeof(struct net_device_stats));
  89
  90                 /* Open up the device */
  91                 ret = net_drv_obj->OnOpen(device_obj);
  92                 if (ret != 0) {
  93                         DPRINT_ERR(NETVSC_DRV,
  94                                    "unable to open device (ret %d).", ret);
  95                         return ret;
  96                 }
  97
  98                 netif_start_queue(net);
  99         } else {
 100                 DPRINT_ERR(NETVSC_DRV, "unable to open device...link is down.");
 101         }
 102
 103         DPRINT_EXIT(NETVSC_DRV);
 104         return ret;
 105 }
 106
 107 static int netvsc_close(struct net_device *net)
 108 {
 109         struct net_device_context *net_device_ctx = netdev_priv(net);
 110         struct driver_context *driver_ctx =
 111             driver_to_driver_context(net_device_ctx->device_ctx->device.driver);
 112         struct netvsc_driver_context *net_drv_ctx =
 113                 (struct netvsc_driver_context *)driver_ctx;
 114         struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 115         struct hv_device *device_obj = &net_device_ctx->device_ctx->device_obj;
 116         int ret;
 117
 118         DPRINT_ENTER(NETVSC_DRV);
 119
 120         netif_stop_queue(net);
 121
 122         ret = net_drv_obj->OnClose(device_obj);
 123         if (ret != 0)
 124                 DPRINT_ERR(NETVSC_DRV, "unable to close device (ret %d).", ret);
 125
 126         DPRINT_EXIT(NETVSC_DRV);
 127
 128         return ret;
 129 }
 130
 131 static void netvsc_xmit_completion(void *context)
 132 {
 133         struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
 134         struct sk_buff *skb = (struct sk_buff *)
 135                 (unsigned long)packet->Completion.Send.SendCompletionTid;
 136         struct net_device *net;
 137
 138         DPRINT_ENTER(NETVSC_DRV);
 139
 140         kfree(packet);
 141
 142         if (skb) {
 143                 net = skb->dev;
 144                 dev_kfree_skb_any(skb);
 145
 146                 if (netif_queue_stopped(net)) {
 147                         DPRINT_INFO(NETVSC_DRV, "net device (%p) waking up...",
 148                                     net);
 149
 150                         netif_wake_queue(net);
 151                 }
 152         }
 153
 154         DPRINT_EXIT(NETVSC_DRV);
 155 }
 156
 157 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 158 {
 159         struct net_device_context *net_device_ctx = netdev_priv(net);
 160         struct driver_context *driver_ctx =
 161             driver_to_driver_context(net_device_ctx->device_ctx->device.driver);
 162         struct netvsc_driver_context *net_drv_ctx =
 163                 (struct netvsc_driver_context *)driver_ctx;
 164         struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 165         struct hv_netvsc_packet *packet;
 166         int i;
 167         int ret;
 168         int num_frags;
 169         int retries = 0;
 170
 171         DPRINT_ENTER(NETVSC_DRV);
 172
 173         /* Support only 1 chain of frags */
 174         ASSERT(skb_shinfo(skb)->frag_list == NULL);
 175         ASSERT(skb->dev == net);
 176
 177         DPRINT_DBG(NETVSC_DRV, "xmit packet - len %d data_len %d",
 178                    skb->len, skb->data_len);
 179
 180         /* Add 1 for skb->data and any additional ones requested */
 181         num_frags = skb_shinfo(skb)->nr_frags + 1 +
 182                     net_drv_obj->AdditionalRequestPageBufferCount;
 183
 184         /* Allocate a netvsc packet based on # of frags. */
 185         packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 186                          (num_frags * sizeof(struct hv_page_buffer)) +
 187                          net_drv_obj->RequestExtSize, GFP_ATOMIC);
 188         if (!packet) {
 189                 DPRINT_ERR(NETVSC_DRV, "unable to allocate hv_netvsc_packet");
 190                 return -1;
 191         }
 192
 193         packet->Extension = (void *)(unsigned long)packet +
 194                                 sizeof(struct hv_netvsc_packet) +
 195                                     (num_frags * sizeof(struct hv_page_buffer));
 196
 197         /* Setup the rndis header */
 198         packet->PageBufferCount = num_frags;
 199
 200         /* TODO: Flush all write buffers/ memory fence ??? */
 201         /* wmb(); */
 202
 203         /* Initialize it from the skb */
 204         ASSERT(skb->data);
 205         packet->TotalDataBufferLength   = skb->len;
 206
 207         /*
 208          * Start filling in the page buffers starting at
 209          * AdditionalRequestPageBufferCount offset
 210          */
 211         packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;
 212         packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Offset = (unsigned long)skb->data & (PAGE_SIZE - 1);
 213         packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Length = skb->len - skb->data_len;
 214
 215         ASSERT((skb->len - skb->data_len) <= PAGE_SIZE);
 216
 217         for (i = net_drv_obj->AdditionalRequestPageBufferCount + 1;
 218              i < num_frags; i++) {
 219                 packet->PageBuffers[i].Pfn =
 220                         page_to_pfn(skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].page);
 221                 packet->PageBuffers[i].Offset =
 222                         skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].page_offset;
 223                 packet->PageBuffers[i].Length =
 224                         skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].size;
 225         }
 226
 227         /* Set the completion routine */
 228         packet->Completion.Send.OnSendCompletion = netvsc_xmit_completion;
 229         packet->Completion.Send.SendCompletionContext = packet;
 230         packet->Completion.Send.SendCompletionTid = (unsigned long)skb;
 231
 232 retry_send:
 233         ret = net_drv_obj->OnSend(&net_device_ctx->device_ctx->device_obj,
 234                                   packet);
 235
 236         if (ret == 0) {
 237                 ret = NETDEV_TX_OK;
 238                 net_device_ctx->stats.tx_bytes += skb->len;
 239                 net_device_ctx->stats.tx_packets++;
 240         } else {
 241                 retries++;
 242                 if (retries < 4) {
 243                         DPRINT_ERR(NETVSC_DRV, "unable to send..."
 244                                         "retrying %d...", retries);
 245                         udelay(100);
 246                         goto retry_send;
 247                 }
 248
 249                 /* no more room or we are shutting down */
 250                 DPRINT_ERR(NETVSC_DRV, "unable to send (%d)..."
 251                            "marking net device (%p) busy", ret, net);
 252                 DPRINT_INFO(NETVSC_DRV, "net device (%p) stopping", net);
 253
 254                 ret = NETDEV_TX_BUSY;
 255                 net_device_ctx->stats.tx_dropped++;
 256
 257                 netif_stop_queue(net);
 258
 259                 /*
 260                  * Null it since the caller will free it instead of the
 261                  * completion routine
 262                  */
 263                 packet->Completion.Send.SendCompletionTid = 0;
 264
 265                 /*
 266                  * Release the resources since we will not get any send
 267                  * completion
 268                  */
 269                 netvsc_xmit_completion((void *)packet);
 270         }
 271
 272         DPRINT_DBG(NETVSC_DRV, "# of xmits %lu total size %lu",
 273                    net_device_ctx->stats.tx_packets,
 274                    net_device_ctx->stats.tx_bytes);
 275
 276         DPRINT_EXIT(NETVSC_DRV);
 277         return ret;
 278 }
 279
 280 /**
 281  * netvsc_linkstatus_callback - Link up/down notification
 282  */
 283 static void netvsc_linkstatus_callback(struct hv_device *device_obj,
 284                                        unsigned int status)
 285 {
 286         struct device_context *device_ctx = to_device_context(device_obj);
 287         struct net_device *net = dev_get_drvdata(&device_ctx->device);
 288         struct net_device_context *ndev_ctx;
 289
 290         DPRINT_ENTER(NETVSC_DRV);
 291
 292         if (!net) {
 293                 DPRINT_ERR(NETVSC_DRV, "got link status but net device "
 294                                 "not initialized yet");
 295                 return;
 296         }
 297
 298         if (status == 1) {
 299                 netif_carrier_on(net);
 300                 netif_wake_queue(net);
 301                 netif_notify_peers(net);
 302                 ndev_ctx = netdev_priv(net);
 303                 schedule_work(&ndev_ctx->work);
 304         } else {
 305                 netif_carrier_off(net);
 306                 netif_stop_queue(net);
 307         }
 308         DPRINT_EXIT(NETVSC_DRV);
 309 }
 310
 311 /**
 312  * netvsc_recv_callback -  Callback when we receive a packet from the "wire" on the specified device.
 313  */
 314 static int netvsc_recv_callback(struct hv_device *device_obj,
 315                                 struct hv_netvsc_packet *packet)
 316 {
 317         struct device_context *device_ctx = to_device_context(device_obj);
 318         struct net_device *net = dev_get_drvdata(&device_ctx->device);
 319         struct net_device_context *net_device_ctx;
 320         struct sk_buff *skb;
 321         void *data;
 322         int ret;
 323         int i;
 324         unsigned long flags;
 325
 326         DPRINT_ENTER(NETVSC_DRV);
 327
 328         if (!net) {
 329                 DPRINT_ERR(NETVSC_DRV, "got receive callback but net device "
 330                                 "not initialized yet");
 331                 return 0;
 332         }
 333
 334         net_device_ctx = netdev_priv(net);
 335
 336         /* Allocate a skb - TODO preallocate this */
 337         /* Pad 2-bytes to align IP header to 16 bytes */
 338         skb = dev_alloc_skb(packet->TotalDataBufferLength + 2);
 339         ASSERT(skb);
 340         skb_reserve(skb, 2);
 341         skb->dev = net;
 342
 343         /* for kmap_atomic */
 344         local_irq_save(flags);
 345
 346         /*
 347          * Copy to skb. This copy is needed here since the memory pointed by
 348          * hv_netvsc_packet cannot be deallocated
 349          */
 350         for (i = 0; i < packet->PageBufferCount; i++) {
 351                 data = kmap_atomic(pfn_to_page(packet->PageBuffers[i].Pfn),
 352                                                KM_IRQ1);
 353                 data = (void *)(unsigned long)data +
 354                                 packet->PageBuffers[i].Offset;
 355
 356                 memcpy(skb_put(skb, packet->PageBuffers[i].Length), data,
 357                        packet->PageBuffers[i].Length);
 358
 359                 kunmap_atomic((void *)((unsigned long)data -
 360                                        packet->PageBuffers[i].Offset), KM_IRQ1);
 361         }
 362
 363         local_irq_restore(flags);
 364
 365         skb->protocol = eth_type_trans(skb, net);
 366
 367         skb->ip_summed = CHECKSUM_NONE;
 368
 369         /*
 370          * Pass the skb back up. Network stack will deallocate the skb when it
 371          * is done
 372          */
 373         ret = netif_rx(skb);
 374
 375         switch (ret) {
 376         case NET_RX_DROP:
 377                 net_device_ctx->stats.rx_dropped++;
 378                 break;
 379         default:
 380                 net_device_ctx->stats.rx_packets++;
 381                 net_device_ctx->stats.rx_bytes += skb->len;
 382                 break;
 383
 384         }
 385         DPRINT_DBG(NETVSC_DRV, "# of recvs %lu total size %lu",
 386                    net_device_ctx->stats.rx_packets,
 387                    net_device_ctx->stats.rx_bytes);
 388
 389         DPRINT_EXIT(NETVSC_DRV);
 390
 391         return 0;
 392 }
 393
 394 static const struct net_device_ops device_ops = {
 395         .ndo_open =                     netvsc_open,
 396         .ndo_stop =                     netvsc_close,
 397         .ndo_start_xmit =               netvsc_start_xmit,
 398         .ndo_get_stats =                netvsc_get_stats,
 399         .ndo_set_multicast_list =       netvsc_set_multicast_list,
 400         .ndo_change_mtu =               eth_change_mtu,
 401         .ndo_validate_addr =            eth_validate_addr,
 402         .ndo_set_mac_address =          eth_mac_addr,
 403 };
 404
 405 /*
 406  * Send GARP packet to network peers after migrations.
 407  * After Quick Migration, the network is not immediately operational in the
 408  * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
 409  * another netif_notify_peers() into a scheduled work, otherwise GARP packet
 410  * will not be sent after quick migration, and cause network disconnection.
 411  */
 412 static void netvsc_send_garp(struct work_struct *w)
 413 {
 414         struct net_device_context *ndev_ctx;
 415         struct net_device *net;
 416
 417         msleep(20);
 418         ndev_ctx = container_of(w, struct net_device_context, work);
 419         net = dev_get_drvdata(&ndev_ctx->device_ctx->device);
 420         netif_notify_peers(net);
 421 }
 422
 423
 424 static int netvsc_probe(struct device *device)
 425 {
 426         struct driver_context *driver_ctx =
 427                 driver_to_driver_context(device->driver);
 428         struct netvsc_driver_context *net_drv_ctx =
 429                 (struct netvsc_driver_context *)driver_ctx;
 430         struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 431         struct device_context *device_ctx = device_to_device_context(device);
 432         struct hv_device *device_obj = &device_ctx->device_obj;
 433         struct net_device *net = NULL;
 434         struct net_device_context *net_device_ctx;
 435         struct netvsc_device_info device_info;
 436         int ret;
 437
 438         DPRINT_ENTER(NETVSC_DRV);
 439
 440         if (!net_drv_obj->Base.OnDeviceAdd)
 441                 return -1;
 442
 443         net = alloc_etherdev(sizeof(struct net_device_context));
 444         if (!net)
 445                 return -1;
 446
 447         /* Set initial state */
 448         netif_carrier_off(net);
 449         netif_stop_queue(net);
 450
 451         net_device_ctx = netdev_priv(net);
 452         net_device_ctx->device_ctx = device_ctx;
 453         dev_set_drvdata(device, net);
 454         INIT_WORK(&net_device_ctx->work, netvsc_send_garp);
 455
 456         /* Notify the netvsc driver of the new device */
 457         ret = net_drv_obj->Base.OnDeviceAdd(device_obj, &device_info);
 458         if (ret != 0) {
 459                 free_netdev(net);
 460                 dev_set_drvdata(device, NULL);
 461
 462                 DPRINT_ERR(NETVSC_DRV, "unable to add netvsc device (ret %d)",
 463                            ret);
 464                 return ret;
 465         }
 466
 467         /*
 468          * If carrier is still off ie we did not get a link status callback,
 469          * update it if necessary
 470          */
 471         /*
 472          * FIXME: We should use a atomic or test/set instead to avoid getting
 473          * out of sync with the device's link status
 474          */
 475         if (!netif_carrier_ok(net))
 476                 if (!device_info.LinkState)
 477                         netif_carrier_on(net);
 478
 479         memcpy(net->dev_addr, device_info.MacAddr, ETH_ALEN);
 480
 481         net->netdev_ops = &device_ops;
 482
 483         SET_NETDEV_DEV(net, device);
 484
 485         ret = register_netdev(net);
 486         if (ret != 0) {
 487                 /* Remove the device and release the resource */
 488                 net_drv_obj->Base.OnDeviceRemove(device_obj);
 489                 free_netdev(net);
 490         }
 491
 492         DPRINT_EXIT(NETVSC_DRV);
 493         return ret;
 494 }
 495
 496 static int netvsc_remove(struct device *device)
 497 {
 498         struct driver_context *driver_ctx =
 499                 driver_to_driver_context(device->driver);
 500         struct netvsc_driver_context *net_drv_ctx =
 501                 (struct netvsc_driver_context *)driver_ctx;
 502         struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 503         struct device_context *device_ctx = device_to_device_context(device);
 504         struct net_device *net = dev_get_drvdata(&device_ctx->device);
 505         struct hv_device *device_obj = &device_ctx->device_obj;
 506         int ret;
 507
 508         DPRINT_ENTER(NETVSC_DRV);
 509
 510         if (net == NULL) {
 511                 DPRINT_INFO(NETVSC, "no net device to remove");
 512                 DPRINT_EXIT(NETVSC_DRV);
 513                 return 0;
 514         }
 515
 516         if (!net_drv_obj->Base.OnDeviceRemove) {
 517                 DPRINT_EXIT(NETVSC_DRV);
 518                 return -1;
 519         }
 520
 521         /* Stop outbound asap */
 522         netif_stop_queue(net);
 523         /* netif_carrier_off(net); */
 524
 525         unregister_netdev(net);
 526
 527         /*
 528          * Call to the vsc driver to let it know that the device is being
 529          * removed
 530          */
 531         ret = net_drv_obj->Base.OnDeviceRemove(device_obj);
 532         if (ret != 0) {
 533                 /* TODO: */
 534                 DPRINT_ERR(NETVSC, "unable to remove vsc device (ret %d)", ret);
 535         }
 536
 537         free_netdev(net);
 538         DPRINT_EXIT(NETVSC_DRV);
 539         return ret;
 540 }
 541
 542 static int netvsc_drv_exit_cb(struct device *dev, void *data)
 543 {
 544         struct device **curr = (struct device **)data;
 545
 546         *curr = dev;
 547         /* stop iterating */
 548         return 1;
 549 }
 550
 551 static void netvsc_drv_exit(void)
 552 {
 553         struct netvsc_driver *netvsc_drv_obj = &g_netvsc_drv.drv_obj;
 554         struct driver_context *drv_ctx = &g_netvsc_drv.drv_ctx;
 555         struct device *current_dev;
 556         int ret;
 557
 558         DPRINT_ENTER(NETVSC_DRV);
 559
 560         while (1) {
 561                 current_dev = NULL;
 562
 563                 /* Get the device */
 564                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 565                                              &current_dev, netvsc_drv_exit_cb);
 566                 if (ret)
 567                         DPRINT_WARN(NETVSC_DRV,
 568                                     "driver_for_each_device returned %d", ret);
 569
 570                 if (current_dev == NULL)
 571                         break;
 572
 573                 /* Initiate removal from the top-down */
 574                 DPRINT_INFO(NETVSC_DRV, "unregistering device (%p)...",
 575                             current_dev);
 576
 577                 device_unregister(current_dev);
 578         }
 579
 580         if (netvsc_drv_obj->Base.OnCleanup)
 581                 netvsc_drv_obj->Base.OnCleanup(&netvsc_drv_obj->Base);
 582
 583         vmbus_child_driver_unregister(drv_ctx);
 584
 585         DPRINT_EXIT(NETVSC_DRV);
 586
 587         return;
 588 }
 589
 590 static int netvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 591 {
 592         struct netvsc_driver *net_drv_obj = &g_netvsc_drv.drv_obj;
 593         struct driver_context *drv_ctx = &g_netvsc_drv.drv_ctx;
 594         int ret;
 595
 596         DPRINT_ENTER(NETVSC_DRV);
 597
 598         vmbus_get_interface(&net_drv_obj->Base.VmbusChannelInterface);
 599
 600         net_drv_obj->RingBufferSize = netvsc_ringbuffer_size;
 601         net_drv_obj->OnReceiveCallback = netvsc_recv_callback;
 602         net_drv_obj->OnLinkStatusChanged = netvsc_linkstatus_callback;
 603
 604         /* Callback to client driver to complete the initialization */
 605         drv_init(&net_drv_obj->Base);
 606
 607         drv_ctx->driver.name = net_drv_obj->Base.name;
 608         memcpy(&drv_ctx->class_id, &net_drv_obj->Base.deviceType,
 609                sizeof(struct hv_guid));
 610
 611         drv_ctx->probe = netvsc_probe;
 612         drv_ctx->remove = netvsc_remove;
 613
 614         /* The driver belongs to vmbus */
 615         ret = vmbus_child_driver_register(drv_ctx);
 616
 617         DPRINT_EXIT(NETVSC_DRV);
 618
 619         return ret;
 620 }
 621
 622 static int __init netvsc_init(void)
 623 {
 624         int ret;
 625
 626         DPRINT_ENTER(NETVSC_DRV);
 627         DPRINT_INFO(NETVSC_DRV, "Netvsc initializing....");
 628
 629         ret = netvsc_drv_init(NetVscInitialize);
 630
 631         DPRINT_EXIT(NETVSC_DRV);
 632
 633         return ret;
 634 }
 635
 636 static void __exit netvsc_exit(void)
 637 {
 638         DPRINT_ENTER(NETVSC_DRV);
 639         netvsc_drv_exit();
 640         DPRINT_EXIT(NETVSC_DRV);
 641 }
 642
 643 module_param(netvsc_ringbuffer_size, int, S_IRUGO);
 644
 645 module_init(netvsc_init);
 646 module_exit(netvsc_exit);