linux/drivers/misc/sgi-xp/xpnet.c
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1999-2009 Silicon Graphics, Inc. All rights reserved.
   7 */
   8
   9/*
  10 * Cross Partition Network Interface (XPNET) support
  11 *
  12 *      XPNET provides a virtual network layered on top of the Cross
  13 *      Partition communication layer.
  14 *
  15 *      XPNET provides direct point-to-point and broadcast-like support
  16 *      for an ethernet-like device.  The ethernet broadcast medium is
  17 *      replaced with a point-to-point message structure which passes
  18 *      pointers to a DMA-capable block that a remote partition should
  19 *      retrieve and pass to the upper level networking layer.
  20 *
  21 */
  22
  23#include <linux/slab.h>
  24#include <linux/module.h>
  25#include <linux/netdevice.h>
  26#include <linux/etherdevice.h>
  27#include "xp.h"
  28
  29/*
  30 * The message payload transferred by XPC.
  31 *
  32 * buf_pa is the physical address where the DMA should pull from.
  33 *
  34 * NOTE: for performance reasons, buf_pa should _ALWAYS_ begin on a
  35 * cacheline boundary.  To accomplish this, we record the number of
  36 * bytes from the beginning of the first cacheline to the first useful
  37 * byte of the skb (leadin_ignore) and the number of bytes from the
  38 * last useful byte of the skb to the end of the last cacheline
  39 * (tailout_ignore).
  40 *
  41 * size is the number of bytes to transfer which includes the skb->len
  42 * (useful bytes of the senders skb) plus the leadin and tailout
  43 */
  44struct xpnet_message {
  45        u16 version;            /* Version for this message */
  46        u16 embedded_bytes;     /* #of bytes embedded in XPC message */
  47        u32 magic;              /* Special number indicating this is xpnet */
  48        unsigned long buf_pa;   /* phys address of buffer to retrieve */
  49        u32 size;               /* #of bytes in buffer */
  50        u8 leadin_ignore;       /* #of bytes to ignore at the beginning */
  51        u8 tailout_ignore;      /* #of bytes to ignore at the end */
  52        unsigned char data;     /* body of small packets */
  53};
  54
  55/*
  56 * Determine the size of our message, the cacheline aligned size,
  57 * and then the number of message will request from XPC.
  58 *
  59 * XPC expects each message to exist in an individual cacheline.
  60 */
  61#define XPNET_MSG_SIZE          XPC_MSG_PAYLOAD_MAX_SIZE
  62#define XPNET_MSG_DATA_MAX      \
  63                (XPNET_MSG_SIZE - offsetof(struct xpnet_message, data))
  64#define XPNET_MSG_NENTRIES      (PAGE_SIZE / XPC_MSG_MAX_SIZE)
  65
  66#define XPNET_MAX_KTHREADS      (XPNET_MSG_NENTRIES + 1)
  67#define XPNET_MAX_IDLE_KTHREADS (XPNET_MSG_NENTRIES + 1)
  68
  69/*
  70 * Version number of XPNET implementation. XPNET can always talk to versions
  71 * with same major #, and never talk to versions with a different version.
  72 */
  73#define _XPNET_VERSION(_major, _minor)  (((_major) << 4) | (_minor))
  74#define XPNET_VERSION_MAJOR(_v)         ((_v) >> 4)
  75#define XPNET_VERSION_MINOR(_v)         ((_v) & 0xf)
  76
  77#define XPNET_VERSION _XPNET_VERSION(1, 0)      /* version 1.0 */
  78#define XPNET_VERSION_EMBED _XPNET_VERSION(1, 1)        /* version 1.1 */
  79#define XPNET_MAGIC     0x88786984      /* "XNET" */
  80
  81#define XPNET_VALID_MSG(_m)                                                  \
  82   ((XPNET_VERSION_MAJOR(_m->version) == XPNET_VERSION_MAJOR(XPNET_VERSION)) \
  83    && (msg->magic == XPNET_MAGIC))
  84
  85#define XPNET_DEVICE_NAME               "xp0"
  86
  87/*
  88 * When messages are queued with xpc_send_notify, a kmalloc'd buffer
  89 * of the following type is passed as a notification cookie.  When the
  90 * notification function is called, we use the cookie to decide
  91 * whether all outstanding message sends have completed.  The skb can
  92 * then be released.
  93 */
  94struct xpnet_pending_msg {
  95        struct sk_buff *skb;
  96        atomic_t use_count;
  97};
  98
  99struct net_device *xpnet_device;
 100
 101/*
 102 * When we are notified of other partitions activating, we add them to
 103 * our bitmask of partitions to which we broadcast.
 104 */
 105static unsigned long *xpnet_broadcast_partitions;
 106/* protect above */
 107static DEFINE_SPINLOCK(xpnet_broadcast_lock);
 108
 109/*
 110 * Since the Block Transfer Engine (BTE) is being used for the transfer
 111 * and it relies upon cache-line size transfers, we need to reserve at
 112 * least one cache-line for head and tail alignment.  The BTE is
 113 * limited to 8MB transfers.
 114 *
 115 * Testing has shown that changing MTU to greater than 64KB has no effect
 116 * on TCP as the two sides negotiate a Max Segment Size that is limited
 117 * to 64K.  Other protocols May use packets greater than this, but for
 118 * now, the default is 64KB.
 119 */
 120#define XPNET_MAX_MTU (0x800000UL - L1_CACHE_BYTES)
 121/* 32KB has been determined to be the ideal */
 122#define XPNET_DEF_MTU (0x8000UL)
 123
 124/*
 125 * The partid is encapsulated in the MAC address beginning in the following
 126 * octet and it consists of two octets.
 127 */
 128#define XPNET_PARTID_OCTET      2
 129
 130/* Define the XPNET debug device structures to be used with dev_dbg() et al */
 131
 132struct device_driver xpnet_dbg_name = {
 133        .name = "xpnet"
 134};
 135
 136struct device xpnet_dbg_subname = {
 137        .init_name = "",        /* set to "" */
 138        .driver = &xpnet_dbg_name
 139};
 140
 141struct device *xpnet = &xpnet_dbg_subname;
 142
 143/*
 144 * Packet was recevied by XPC and forwarded to us.
 145 */
 146static void
 147xpnet_receive(short partid, int channel, struct xpnet_message *msg)
 148{
 149        struct sk_buff *skb;
 150        void *dst;
 151        enum xp_retval ret;
 152
 153        if (!XPNET_VALID_MSG(msg)) {
 154                /*
 155                 * Packet with a different XPC version.  Ignore.
 156                 */
 157                xpc_received(partid, channel, (void *)msg);
 158
 159                xpnet_device->stats.rx_errors++;
 160
 161                return;
 162        }
 163        dev_dbg(xpnet, "received 0x%lx, %d, %d, %d\n", msg->buf_pa, msg->size,
 164                msg->leadin_ignore, msg->tailout_ignore);
 165
 166        /* reserve an extra cache line */
 167        skb = dev_alloc_skb(msg->size + L1_CACHE_BYTES);
 168        if (!skb) {
 169                dev_err(xpnet, "failed on dev_alloc_skb(%d)\n",
 170                        msg->size + L1_CACHE_BYTES);
 171
 172                xpc_received(partid, channel, (void *)msg);
 173
 174                xpnet_device->stats.rx_errors++;
 175
 176                return;
 177        }
 178
 179        /*
 180         * The allocated skb has some reserved space.
 181         * In order to use xp_remote_memcpy(), we need to get the
 182         * skb->data pointer moved forward.
 183         */
 184        skb_reserve(skb, (L1_CACHE_BYTES - ((u64)skb->data &
 185                                            (L1_CACHE_BYTES - 1)) +
 186                          msg->leadin_ignore));
 187
 188        /*
 189         * Update the tail pointer to indicate data actually
 190         * transferred.
 191         */
 192        skb_put(skb, (msg->size - msg->leadin_ignore - msg->tailout_ignore));
 193
 194        /*
 195         * Move the data over from the other side.
 196         */
 197        if ((XPNET_VERSION_MINOR(msg->version) == 1) &&
 198            (msg->embedded_bytes != 0)) {
 199                dev_dbg(xpnet, "copying embedded message. memcpy(0x%p, 0x%p, "
 200                        "%lu)\n", skb->data, &msg->data,
 201                        (size_t)msg->embedded_bytes);
 202
 203                skb_copy_to_linear_data(skb, &msg->data,
 204                                        (size_t)msg->embedded_bytes);
 205        } else {
 206                dst = (void *)((u64)skb->data & ~(L1_CACHE_BYTES - 1));
 207                dev_dbg(xpnet, "transferring buffer to the skb->data area;\n\t"
 208                        "xp_remote_memcpy(0x%p, 0x%p, %hu)\n", dst,
 209                                          (void *)msg->buf_pa, msg->size);
 210
 211                ret = xp_remote_memcpy(xp_pa(dst), msg->buf_pa, msg->size);
 212                if (ret != xpSuccess) {
 213                        /*
 214                         * !!! Need better way of cleaning skb.  Currently skb
 215                         * !!! appears in_use and we can't just call
 216                         * !!! dev_kfree_skb.
 217                         */
 218                        dev_err(xpnet, "xp_remote_memcpy(0x%p, 0x%p, 0x%hx) "
 219                                "returned error=0x%x\n", dst,
 220                                (void *)msg->buf_pa, msg->size, ret);
 221
 222                        xpc_received(partid, channel, (void *)msg);
 223
 224                        xpnet_device->stats.rx_errors++;
 225
 226                        return;
 227                }
 228        }
 229
 230        dev_dbg(xpnet, "<skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 231                "skb->end=0x%p skb->len=%d\n", (void *)skb->head,
 232                (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb),
 233                skb->len);
 234
 235        skb->protocol = eth_type_trans(skb, xpnet_device);
 236        skb->ip_summed = CHECKSUM_UNNECESSARY;
 237
 238        dev_dbg(xpnet, "passing skb to network layer\n"
 239                "\tskb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 240                "skb->end=0x%p skb->len=%d\n",
 241                (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb),
 242                skb_end_pointer(skb), skb->len);
 243
 244        xpnet_device->stats.rx_packets++;
 245        xpnet_device->stats.rx_bytes += skb->len + ETH_HLEN;
 246
 247        netif_rx_ni(skb);
 248        xpc_received(partid, channel, (void *)msg);
 249}
 250
 251/*
 252 * This is the handler which XPC calls during any sort of change in
 253 * state or message reception on a connection.
 254 */
 255static void
 256xpnet_connection_activity(enum xp_retval reason, short partid, int channel,
 257                          void *data, void *key)
 258{
 259        DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 260        DBUG_ON(channel != XPC_NET_CHANNEL);
 261
 262        switch (reason) {
 263        case xpMsgReceived:     /* message received */
 264                DBUG_ON(data == NULL);
 265
 266                xpnet_receive(partid, channel, (struct xpnet_message *)data);
 267                break;
 268
 269        case xpConnected:       /* connection completed to a partition */
 270                spin_lock_bh(&xpnet_broadcast_lock);
 271                __set_bit(partid, xpnet_broadcast_partitions);
 272                spin_unlock_bh(&xpnet_broadcast_lock);
 273
 274                netif_carrier_on(xpnet_device);
 275
 276                dev_dbg(xpnet, "%s connected to partition %d\n",
 277                        xpnet_device->name, partid);
 278                break;
 279
 280        default:
 281                spin_lock_bh(&xpnet_broadcast_lock);
 282                __clear_bit(partid, xpnet_broadcast_partitions);
 283                spin_unlock_bh(&xpnet_broadcast_lock);
 284
 285                if (bitmap_empty((unsigned long *)xpnet_broadcast_partitions,
 286                                 xp_max_npartitions)) {
 287                        netif_carrier_off(xpnet_device);
 288                }
 289
 290                dev_dbg(xpnet, "%s disconnected from partition %d\n",
 291                        xpnet_device->name, partid);
 292                break;
 293        }
 294}
 295
 296static int
 297xpnet_dev_open(struct net_device *dev)
 298{
 299        enum xp_retval ret;
 300
 301        dev_dbg(xpnet, "calling xpc_connect(%d, 0x%p, NULL, %ld, %ld, %ld, "
 302                "%ld)\n", XPC_NET_CHANNEL, xpnet_connection_activity,
 303                (unsigned long)XPNET_MSG_SIZE,
 304                (unsigned long)XPNET_MSG_NENTRIES,
 305                (unsigned long)XPNET_MAX_KTHREADS,
 306                (unsigned long)XPNET_MAX_IDLE_KTHREADS);
 307
 308        ret = xpc_connect(XPC_NET_CHANNEL, xpnet_connection_activity, NULL,
 309                          XPNET_MSG_SIZE, XPNET_MSG_NENTRIES,
 310                          XPNET_MAX_KTHREADS, XPNET_MAX_IDLE_KTHREADS);
 311        if (ret != xpSuccess) {
 312                dev_err(xpnet, "ifconfig up of %s failed on XPC connect, "
 313                        "ret=%d\n", dev->name, ret);
 314
 315                return -ENOMEM;
 316        }
 317
 318        dev_dbg(xpnet, "ifconfig up of %s; XPC connected\n", dev->name);
 319
 320        return 0;
 321}
 322
 323static int
 324xpnet_dev_stop(struct net_device *dev)
 325{
 326        xpc_disconnect(XPC_NET_CHANNEL);
 327
 328        dev_dbg(xpnet, "ifconfig down of %s; XPC disconnected\n", dev->name);
 329
 330        return 0;
 331}
 332
 333static int
 334xpnet_dev_change_mtu(struct net_device *dev, int new_mtu)
 335{
 336        /* 68 comes from min TCP+IP+MAC header */
 337        if ((new_mtu < 68) || (new_mtu > XPNET_MAX_MTU)) {
 338                dev_err(xpnet, "ifconfig %s mtu %d failed; value must be "
 339                        "between 68 and %ld\n", dev->name, new_mtu,
 340                        XPNET_MAX_MTU);
 341                return -EINVAL;
 342        }
 343
 344        dev->mtu = new_mtu;
 345        dev_dbg(xpnet, "ifconfig %s mtu set to %d\n", dev->name, new_mtu);
 346        return 0;
 347}
 348
 349/*
 350 * Notification that the other end has received the message and
 351 * DMA'd the skb information.  At this point, they are done with
 352 * our side.  When all recipients are done processing, we
 353 * release the skb and then release our pending message structure.
 354 */
 355static void
 356xpnet_send_completed(enum xp_retval reason, short partid, int channel,
 357                     void *__qm)
 358{
 359        struct xpnet_pending_msg *queued_msg = (struct xpnet_pending_msg *)__qm;
 360
 361        DBUG_ON(queued_msg == NULL);
 362
 363        dev_dbg(xpnet, "message to %d notified with reason %d\n",
 364                partid, reason);
 365
 366        if (atomic_dec_return(&queued_msg->use_count) == 0) {
 367                dev_dbg(xpnet, "all acks for skb->head=-x%p\n",
 368                        (void *)queued_msg->skb->head);
 369
 370                dev_kfree_skb_any(queued_msg->skb);
 371                kfree(queued_msg);
 372        }
 373}
 374
 375static void
 376xpnet_send(struct sk_buff *skb, struct xpnet_pending_msg *queued_msg,
 377           u64 start_addr, u64 end_addr, u16 embedded_bytes, int dest_partid)
 378{
 379        u8 msg_buffer[XPNET_MSG_SIZE];
 380        struct xpnet_message *msg = (struct xpnet_message *)&msg_buffer;
 381        u16 msg_size = sizeof(struct xpnet_message);
 382        enum xp_retval ret;
 383
 384        msg->embedded_bytes = embedded_bytes;
 385        if (unlikely(embedded_bytes != 0)) {
 386                msg->version = XPNET_VERSION_EMBED;
 387                dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n",
 388                        &msg->data, skb->data, (size_t)embedded_bytes);
 389                skb_copy_from_linear_data(skb, &msg->data,
 390                                          (size_t)embedded_bytes);
 391                msg_size += embedded_bytes - 1;
 392        } else {
 393                msg->version = XPNET_VERSION;
 394        }
 395        msg->magic = XPNET_MAGIC;
 396        msg->size = end_addr - start_addr;
 397        msg->leadin_ignore = (u64)skb->data - start_addr;
 398        msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb);
 399        msg->buf_pa = xp_pa((void *)start_addr);
 400
 401        dev_dbg(xpnet, "sending XPC message to %d:%d\n"
 402                "msg->buf_pa=0x%lx, msg->size=%u, "
 403                "msg->leadin_ignore=%u, msg->tailout_ignore=%u\n",
 404                dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size,
 405                msg->leadin_ignore, msg->tailout_ignore);
 406
 407        atomic_inc(&queued_msg->use_count);
 408
 409        ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, XPC_NOWAIT, msg,
 410                              msg_size, xpnet_send_completed, queued_msg);
 411        if (unlikely(ret != xpSuccess))
 412                atomic_dec(&queued_msg->use_count);
 413}
 414
 415/*
 416 * Network layer has formatted a packet (skb) and is ready to place it
 417 * "on the wire".  Prepare and send an xpnet_message to all partitions
 418 * which have connected with us and are targets of this packet.
 419 *
 420 * MAC-NOTE:  For the XPNET driver, the MAC address contains the
 421 * destination partid.  If the destination partid octets are 0xffff,
 422 * this packet is to be broadcast to all connected partitions.
 423 */
 424static int
 425xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 426{
 427        struct xpnet_pending_msg *queued_msg;
 428        u64 start_addr, end_addr;
 429        short dest_partid;
 430        u16 embedded_bytes = 0;
 431
 432        dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 433                "skb->end=0x%p skb->len=%d\n", (void *)skb->head,
 434                (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb),
 435                skb->len);
 436
 437        if (skb->data[0] == 0x33) {
 438                dev_kfree_skb(skb);
 439                return NETDEV_TX_OK;    /* nothing needed to be done */
 440        }
 441
 442        /*
 443         * The xpnet_pending_msg tracks how many outstanding
 444         * xpc_send_notifies are relying on this skb.  When none
 445         * remain, release the skb.
 446         */
 447        queued_msg = kmalloc(sizeof(struct xpnet_pending_msg), GFP_ATOMIC);
 448        if (queued_msg == NULL) {
 449                dev_warn(xpnet, "failed to kmalloc %ld bytes; dropping "
 450                         "packet\n", sizeof(struct xpnet_pending_msg));
 451
 452                dev->stats.tx_errors++;
 453                dev_kfree_skb(skb);
 454                return NETDEV_TX_OK;
 455        }
 456
 457        /* get the beginning of the first cacheline and end of last */
 458        start_addr = ((u64)skb->data & ~(L1_CACHE_BYTES - 1));
 459        end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb));
 460
 461        /* calculate how many bytes to embed in the XPC message */
 462        if (unlikely(skb->len <= XPNET_MSG_DATA_MAX)) {
 463                /* skb->data does fit so embed */
 464                embedded_bytes = skb->len;
 465        }
 466
 467        /*
 468         * Since the send occurs asynchronously, we set the count to one
 469         * and begin sending.  Any sends that happen to complete before
 470         * we are done sending will not free the skb.  We will be left
 471         * with that task during exit.  This also handles the case of
 472         * a packet destined for a partition which is no longer up.
 473         */
 474        atomic_set(&queued_msg->use_count, 1);
 475        queued_msg->skb = skb;
 476
 477        if (skb->data[0] == 0xff) {
 478                /* we are being asked to broadcast to all partitions */
 479                for_each_set_bit(dest_partid, xpnet_broadcast_partitions,
 480                             xp_max_npartitions) {
 481
 482                        xpnet_send(skb, queued_msg, start_addr, end_addr,
 483                                   embedded_bytes, dest_partid);
 484                }
 485        } else {
 486                dest_partid = (short)skb->data[XPNET_PARTID_OCTET + 1];
 487                dest_partid |= (short)skb->data[XPNET_PARTID_OCTET + 0] << 8;
 488
 489                if (dest_partid >= 0 &&
 490                    dest_partid < xp_max_npartitions &&
 491                    test_bit(dest_partid, xpnet_broadcast_partitions) != 0) {
 492
 493                        xpnet_send(skb, queued_msg, start_addr, end_addr,
 494                                   embedded_bytes, dest_partid);
 495                }
 496        }
 497
 498        dev->stats.tx_packets++;
 499        dev->stats.tx_bytes += skb->len;
 500
 501        if (atomic_dec_return(&queued_msg->use_count) == 0) {
 502                dev_kfree_skb(skb);
 503                kfree(queued_msg);
 504        }
 505
 506        return NETDEV_TX_OK;
 507}
 508
 509/*
 510 * Deal with transmit timeouts coming from the network layer.
 511 */
 512static void
 513xpnet_dev_tx_timeout(struct net_device *dev)
 514{
 515        dev->stats.tx_errors++;
 516}
 517
 518static const struct net_device_ops xpnet_netdev_ops = {
 519        .ndo_open               = xpnet_dev_open,
 520        .ndo_stop               = xpnet_dev_stop,
 521        .ndo_start_xmit         = xpnet_dev_hard_start_xmit,
 522        .ndo_change_mtu         = xpnet_dev_change_mtu,
 523        .ndo_tx_timeout         = xpnet_dev_tx_timeout,
 524        .ndo_set_mac_address    = eth_mac_addr,
 525        .ndo_validate_addr      = eth_validate_addr,
 526};
 527
 528static int __init
 529xpnet_init(void)
 530{
 531        int result;
 532
 533        if (!is_shub() && !is_uv())
 534                return -ENODEV;
 535
 536        dev_info(xpnet, "registering network device %s\n", XPNET_DEVICE_NAME);
 537
 538        xpnet_broadcast_partitions = kzalloc(BITS_TO_LONGS(xp_max_npartitions) *
 539                                             sizeof(long), GFP_KERNEL);
 540        if (xpnet_broadcast_partitions == NULL)
 541                return -ENOMEM;
 542
 543        /*
 544         * use ether_setup() to init the majority of our device
 545         * structure and then override the necessary pieces.
 546         */
 547        xpnet_device = alloc_netdev(0, XPNET_DEVICE_NAME, ether_setup);
 548        if (xpnet_device == NULL) {
 549                kfree(xpnet_broadcast_partitions);
 550                return -ENOMEM;
 551        }
 552
 553        netif_carrier_off(xpnet_device);
 554
 555        xpnet_device->netdev_ops = &xpnet_netdev_ops;
 556        xpnet_device->mtu = XPNET_DEF_MTU;
 557
 558        /*
 559         * Multicast assumes the LSB of the first octet is set for multicast
 560         * MAC addresses.  We chose the first octet of the MAC to be unlikely
 561         * to collide with any vendor's officially issued MAC.
 562         */
 563        xpnet_device->dev_addr[0] = 0x02;     /* locally administered, no OUI */
 564
 565        xpnet_device->dev_addr[XPNET_PARTID_OCTET + 1] = xp_partition_id;
 566        xpnet_device->dev_addr[XPNET_PARTID_OCTET + 0] = (xp_partition_id >> 8);
 567
 568        /*
 569         * ether_setup() sets this to a multicast device.  We are
 570         * really not supporting multicast at this time.
 571         */
 572        xpnet_device->flags &= ~IFF_MULTICAST;
 573
 574        /*
 575         * No need to checksum as it is a DMA transfer.  The BTE will
 576         * report an error if the data is not retrievable and the
 577         * packet will be dropped.
 578         */
 579        xpnet_device->features = NETIF_F_HW_CSUM;
 580
 581        result = register_netdev(xpnet_device);
 582        if (result != 0) {
 583                free_netdev(xpnet_device);
 584                kfree(xpnet_broadcast_partitions);
 585        }
 586
 587        return result;
 588}
 589
 590module_init(xpnet_init);
 591
 592static void __exit
 593xpnet_exit(void)
 594{
 595        dev_info(xpnet, "unregistering network device %s\n",
 596                 xpnet_device[0].name);
 597
 598        unregister_netdev(xpnet_device);
 599        free_netdev(xpnet_device);
 600        kfree(xpnet_broadcast_partitions);
 601}
 602
 603module_exit(xpnet_exit);
 604
 605MODULE_AUTHOR("Silicon Graphics, Inc.");
 606MODULE_DESCRIPTION("Cross Partition Network adapter (XPNET)");
 607MODULE_LICENSE("GPL");
 608