xpnet.c revision 2c2b94f93f4732c3b9703ce62627e6187e7d6128
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) 1999-2008 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/module.h> 24#include <linux/types.h> 25#include <linux/kernel.h> 26#include <linux/init.h> 27#include <linux/ioport.h> 28#include <linux/netdevice.h> 29#include <linux/etherdevice.h> 30#include <linux/delay.h> 31#include <linux/ethtool.h> 32#include <linux/mii.h> 33#include <linux/smp.h> 34#include <linux/string.h> 35#include <asm/sn/bte.h> 36#include <asm/sn/io.h> 37#include <asm/sn/sn_sal.h> 38#include <asm/atomic.h> 39#include "xp.h" 40 41/* 42 * The message payload transferred by XPC. 43 * 44 * buf_pa is the physical address where the DMA should pull from. 45 * 46 * NOTE: for performance reasons, buf_pa should _ALWAYS_ begin on a 47 * cacheline boundary. To accomplish this, we record the number of 48 * bytes from the beginning of the first cacheline to the first useful 49 * byte of the skb (leadin_ignore) and the number of bytes from the 50 * last useful byte of the skb to the end of the last cacheline 51 * (tailout_ignore). 52 * 53 * size is the number of bytes to transfer which includes the skb->len 54 * (useful bytes of the senders skb) plus the leadin and tailout 55 */ 56struct xpnet_message { 57 u16 version; /* Version for this message */ 58 u16 embedded_bytes; /* #of bytes embedded in XPC message */ 59 u32 magic; /* Special number indicating this is xpnet */ 60 u64 buf_pa; /* phys address of buffer to retrieve */ 61 u32 size; /* #of bytes in buffer */ 62 u8 leadin_ignore; /* #of bytes to ignore at the beginning */ 63 u8 tailout_ignore; /* #of bytes to ignore at the end */ 64 unsigned char data; /* body of small packets */ 65}; 66 67/* 68 * Determine the size of our message, the cacheline aligned size, 69 * and then the number of message will request from XPC. 70 * 71 * XPC expects each message to exist in an individual cacheline. 72 */ 73#define XPNET_MSG_SIZE (L1_CACHE_BYTES - XPC_MSG_PAYLOAD_OFFSET) 74#define XPNET_MSG_DATA_MAX \ 75 (XPNET_MSG_SIZE - (u64)(&((struct xpnet_message *)0)->data)) 76#define XPNET_MSG_ALIGNED_SIZE (L1_CACHE_ALIGN(XPNET_MSG_SIZE)) 77#define XPNET_MSG_NENTRIES (PAGE_SIZE / XPNET_MSG_ALIGNED_SIZE) 78 79#define XPNET_MAX_KTHREADS (XPNET_MSG_NENTRIES + 1) 80#define XPNET_MAX_IDLE_KTHREADS (XPNET_MSG_NENTRIES + 1) 81 82/* 83 * Version number of XPNET implementation. XPNET can always talk to versions 84 * with same major #, and never talk to versions with a different version. 85 */ 86#define _XPNET_VERSION(_major, _minor) (((_major) << 4) | (_minor)) 87#define XPNET_VERSION_MAJOR(_v) ((_v) >> 4) 88#define XPNET_VERSION_MINOR(_v) ((_v) & 0xf) 89 90#define XPNET_VERSION _XPNET_VERSION(1, 0) /* version 1.0 */ 91#define XPNET_VERSION_EMBED _XPNET_VERSION(1, 1) /* version 1.1 */ 92#define XPNET_MAGIC 0x88786984 /* "XNET" */ 93 94#define XPNET_VALID_MSG(_m) \ 95 ((XPNET_VERSION_MAJOR(_m->version) == XPNET_VERSION_MAJOR(XPNET_VERSION)) \ 96 && (msg->magic == XPNET_MAGIC)) 97 98#define XPNET_DEVICE_NAME "xp0" 99 100/* 101 * When messages are queued with xpc_send_notify, a kmalloc'd buffer 102 * of the following type is passed as a notification cookie. When the 103 * notification function is called, we use the cookie to decide 104 * whether all outstanding message sends have completed. The skb can 105 * then be released. 106 */ 107struct xpnet_pending_msg { 108 struct list_head free_list; 109 struct sk_buff *skb; 110 atomic_t use_count; 111}; 112 113/* driver specific structure pointed to by the device structure */ 114struct xpnet_dev_private { 115 struct net_device_stats stats; 116}; 117 118struct net_device *xpnet_device; 119 120/* 121 * When we are notified of other partitions activating, we add them to 122 * our bitmask of partitions to which we broadcast. 123 */ 124static u64 xpnet_broadcast_partitions; 125/* protect above */ 126static DEFINE_SPINLOCK(xpnet_broadcast_lock); 127 128/* 129 * Since the Block Transfer Engine (BTE) is being used for the transfer 130 * and it relies upon cache-line size transfers, we need to reserve at 131 * least one cache-line for head and tail alignment. The BTE is 132 * limited to 8MB transfers. 133 * 134 * Testing has shown that changing MTU to greater than 64KB has no effect 135 * on TCP as the two sides negotiate a Max Segment Size that is limited 136 * to 64K. Other protocols May use packets greater than this, but for 137 * now, the default is 64KB. 138 */ 139#define XPNET_MAX_MTU (0x800000UL - L1_CACHE_BYTES) 140/* 32KB has been determined to be the ideal */ 141#define XPNET_DEF_MTU (0x8000UL) 142 143/* 144 * The partition id is encapsulated in the MAC address. The following 145 * define locates the octet the partid is in. 146 */ 147#define XPNET_PARTID_OCTET 1 148#define XPNET_LICENSE_OCTET 2 149 150/* 151 * Define the XPNET debug device structure that is to be used with dev_dbg(), 152 * dev_err(), dev_warn(), and dev_info(). 153 */ 154struct device_driver xpnet_dbg_name = { 155 .name = "xpnet" 156}; 157 158struct device xpnet_dbg_subname = { 159 .bus_id = {0}, /* set to "" */ 160 .driver = &xpnet_dbg_name 161}; 162 163struct device *xpnet = &xpnet_dbg_subname; 164 165/* 166 * Packet was recevied by XPC and forwarded to us. 167 */ 168static void 169xpnet_receive(partid_t partid, int channel, struct xpnet_message *msg) 170{ 171 struct sk_buff *skb; 172 bte_result_t bret; 173 struct xpnet_dev_private *priv = 174 (struct xpnet_dev_private *)xpnet_device->priv; 175 176 if (!XPNET_VALID_MSG(msg)) { 177 /* 178 * Packet with a different XPC version. Ignore. 179 */ 180 xpc_received(partid, channel, (void *)msg); 181 182 priv->stats.rx_errors++; 183 184 return; 185 } 186 dev_dbg(xpnet, "received 0x%lx, %d, %d, %d\n", msg->buf_pa, msg->size, 187 msg->leadin_ignore, msg->tailout_ignore); 188 189 /* reserve an extra cache line */ 190 skb = dev_alloc_skb(msg->size + L1_CACHE_BYTES); 191 if (!skb) { 192 dev_err(xpnet, "failed on dev_alloc_skb(%d)\n", 193 msg->size + L1_CACHE_BYTES); 194 195 xpc_received(partid, channel, (void *)msg); 196 197 priv->stats.rx_errors++; 198 199 return; 200 } 201 202 /* 203 * The allocated skb has some reserved space. 204 * In order to use bte_copy, we need to get the 205 * skb->data pointer moved forward. 206 */ 207 skb_reserve(skb, (L1_CACHE_BYTES - ((u64)skb->data & 208 (L1_CACHE_BYTES - 1)) + 209 msg->leadin_ignore)); 210 211 /* 212 * Update the tail pointer to indicate data actually 213 * transferred. 214 */ 215 skb_put(skb, (msg->size - msg->leadin_ignore - msg->tailout_ignore)); 216 217 /* 218 * Move the data over from the other side. 219 */ 220 if ((XPNET_VERSION_MINOR(msg->version) == 1) && 221 (msg->embedded_bytes != 0)) { 222 dev_dbg(xpnet, "copying embedded message. memcpy(0x%p, 0x%p, " 223 "%lu)\n", skb->data, &msg->data, 224 (size_t)msg->embedded_bytes); 225 226 skb_copy_to_linear_data(skb, &msg->data, 227 (size_t)msg->embedded_bytes); 228 } else { 229 dev_dbg(xpnet, "transferring buffer to the skb->data area;\n\t" 230 "bte_copy(0x%p, 0x%p, %hu)\n", (void *)msg->buf_pa, 231 (void *)__pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)), 232 msg->size); 233 234 bret = bte_copy(msg->buf_pa, 235 __pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)), 236 msg->size, (BTE_NOTIFY | BTE_WACQUIRE), NULL); 237 238 if (bret != BTE_SUCCESS) { 239 /* 240 * >>> Need better way of cleaning skb. Currently skb 241 * >>> appears in_use and we can't just call 242 * >>> dev_kfree_skb. 243 */ 244 dev_err(xpnet, "bte_copy(0x%p, 0x%p, 0x%hx) returned " 245 "error=0x%x\n", (void *)msg->buf_pa, 246 (void *)__pa((u64)skb->data & 247 ~(L1_CACHE_BYTES - 1)), 248 msg->size, bret); 249 250 xpc_received(partid, channel, (void *)msg); 251 252 priv->stats.rx_errors++; 253 254 return; 255 } 256 } 257 258 dev_dbg(xpnet, "<skb->head=0x%p skb->data=0x%p skb->tail=0x%p " 259 "skb->end=0x%p skb->len=%d\n", (void *)skb->head, 260 (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb), 261 skb->len); 262 263 skb->protocol = eth_type_trans(skb, xpnet_device); 264 skb->ip_summed = CHECKSUM_UNNECESSARY; 265 266 dev_dbg(xpnet, "passing skb to network layer\n" 267 KERN_DEBUG "\tskb->head=0x%p skb->data=0x%p skb->tail=0x%p " 268 "skb->end=0x%p skb->len=%d\n", 269 (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb), 270 skb_end_pointer(skb), skb->len); 271 272 xpnet_device->last_rx = jiffies; 273 priv->stats.rx_packets++; 274 priv->stats.rx_bytes += skb->len + ETH_HLEN; 275 276 netif_rx_ni(skb); 277 xpc_received(partid, channel, (void *)msg); 278} 279 280/* 281 * This is the handler which XPC calls during any sort of change in 282 * state or message reception on a connection. 283 */ 284static void 285xpnet_connection_activity(enum xpc_retval reason, partid_t partid, int channel, 286 void *data, void *key) 287{ 288 long bp; 289 290 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); 291 DBUG_ON(channel != XPC_NET_CHANNEL); 292 293 switch (reason) { 294 case xpcMsgReceived: /* message received */ 295 DBUG_ON(data == NULL); 296 297 xpnet_receive(partid, channel, (struct xpnet_message *)data); 298 break; 299 300 case xpcConnected: /* connection completed to a partition */ 301 spin_lock_bh(&xpnet_broadcast_lock); 302 xpnet_broadcast_partitions |= 1UL << (partid - 1); 303 bp = xpnet_broadcast_partitions; 304 spin_unlock_bh(&xpnet_broadcast_lock); 305 306 netif_carrier_on(xpnet_device); 307 308 dev_dbg(xpnet, "%s connection created to partition %d; " 309 "xpnet_broadcast_partitions=0x%lx\n", 310 xpnet_device->name, partid, bp); 311 break; 312 313 default: 314 spin_lock_bh(&xpnet_broadcast_lock); 315 xpnet_broadcast_partitions &= ~(1UL << (partid - 1)); 316 bp = xpnet_broadcast_partitions; 317 spin_unlock_bh(&xpnet_broadcast_lock); 318 319 if (bp == 0) 320 netif_carrier_off(xpnet_device); 321 322 dev_dbg(xpnet, "%s disconnected from partition %d; " 323 "xpnet_broadcast_partitions=0x%lx\n", 324 xpnet_device->name, partid, bp); 325 break; 326 327 } 328} 329 330static int 331xpnet_dev_open(struct net_device *dev) 332{ 333 enum xpc_retval ret; 334 335 dev_dbg(xpnet, "calling xpc_connect(%d, 0x%p, NULL, %ld, %ld, %ld, " 336 "%ld)\n", XPC_NET_CHANNEL, xpnet_connection_activity, 337 XPNET_MSG_SIZE, XPNET_MSG_NENTRIES, XPNET_MAX_KTHREADS, 338 XPNET_MAX_IDLE_KTHREADS); 339 340 ret = xpc_connect(XPC_NET_CHANNEL, xpnet_connection_activity, NULL, 341 XPNET_MSG_SIZE, XPNET_MSG_NENTRIES, 342 XPNET_MAX_KTHREADS, XPNET_MAX_IDLE_KTHREADS); 343 if (ret != xpcSuccess) { 344 dev_err(xpnet, "ifconfig up of %s failed on XPC connect, " 345 "ret=%d\n", dev->name, ret); 346 347 return -ENOMEM; 348 } 349 350 dev_dbg(xpnet, "ifconfig up of %s; XPC connected\n", dev->name); 351 352 return 0; 353} 354 355static int 356xpnet_dev_stop(struct net_device *dev) 357{ 358 xpc_disconnect(XPC_NET_CHANNEL); 359 360 dev_dbg(xpnet, "ifconfig down of %s; XPC disconnected\n", dev->name); 361 362 return 0; 363} 364 365static int 366xpnet_dev_change_mtu(struct net_device *dev, int new_mtu) 367{ 368 /* 68 comes from min TCP+IP+MAC header */ 369 if ((new_mtu < 68) || (new_mtu > XPNET_MAX_MTU)) { 370 dev_err(xpnet, "ifconfig %s mtu %d failed; value must be " 371 "between 68 and %ld\n", dev->name, new_mtu, 372 XPNET_MAX_MTU); 373 return -EINVAL; 374 } 375 376 dev->mtu = new_mtu; 377 dev_dbg(xpnet, "ifconfig %s mtu set to %d\n", dev->name, new_mtu); 378 return 0; 379} 380 381/* 382 * Required for the net_device structure. 383 */ 384static int 385xpnet_dev_set_config(struct net_device *dev, struct ifmap *new_map) 386{ 387 return 0; 388} 389 390/* 391 * Return statistics to the caller. 392 */ 393static struct net_device_stats * 394xpnet_dev_get_stats(struct net_device *dev) 395{ 396 struct xpnet_dev_private *priv; 397 398 priv = (struct xpnet_dev_private *)dev->priv; 399 400 return &priv->stats; 401} 402 403/* 404 * Notification that the other end has received the message and 405 * DMA'd the skb information. At this point, they are done with 406 * our side. When all recipients are done processing, we 407 * release the skb and then release our pending message structure. 408 */ 409static void 410xpnet_send_completed(enum xpc_retval reason, partid_t partid, int channel, 411 void *__qm) 412{ 413 struct xpnet_pending_msg *queued_msg = (struct xpnet_pending_msg *)__qm; 414 415 DBUG_ON(queued_msg == NULL); 416 417 dev_dbg(xpnet, "message to %d notified with reason %d\n", 418 partid, reason); 419 420 if (atomic_dec_return(&queued_msg->use_count) == 0) { 421 dev_dbg(xpnet, "all acks for skb->head=-x%p\n", 422 (void *)queued_msg->skb->head); 423 424 dev_kfree_skb_any(queued_msg->skb); 425 kfree(queued_msg); 426 } 427} 428 429/* 430 * Network layer has formatted a packet (skb) and is ready to place it 431 * "on the wire". Prepare and send an xpnet_message to all partitions 432 * which have connected with us and are targets of this packet. 433 * 434 * MAC-NOTE: For the XPNET driver, the MAC address contains the 435 * destination partition_id. If the destination partition id word 436 * is 0xff, this packet is to broadcast to all partitions. 437 */ 438static int 439xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) 440{ 441 struct xpnet_pending_msg *queued_msg; 442 enum xpc_retval ret; 443 struct xpnet_message *msg; 444 u64 start_addr, end_addr; 445 long dp; 446 u8 second_mac_octet; 447 partid_t dest_partid; 448 struct xpnet_dev_private *priv; 449 u16 embedded_bytes; 450 451 priv = (struct xpnet_dev_private *)dev->priv; 452 453 dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p " 454 "skb->end=0x%p skb->len=%d\n", (void *)skb->head, 455 (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb), 456 skb->len); 457 458 /* 459 * The xpnet_pending_msg tracks how many outstanding 460 * xpc_send_notifies are relying on this skb. When none 461 * remain, release the skb. 462 */ 463 queued_msg = kmalloc(sizeof(struct xpnet_pending_msg), GFP_ATOMIC); 464 if (queued_msg == NULL) { 465 dev_warn(xpnet, "failed to kmalloc %ld bytes; dropping " 466 "packet\n", sizeof(struct xpnet_pending_msg)); 467 468 priv->stats.tx_errors++; 469 470 return -ENOMEM; 471 } 472 473 /* get the beginning of the first cacheline and end of last */ 474 start_addr = ((u64)skb->data & ~(L1_CACHE_BYTES - 1)); 475 end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb)); 476 477 /* calculate how many bytes to embed in the XPC message */ 478 embedded_bytes = 0; 479 if (unlikely(skb->len <= XPNET_MSG_DATA_MAX)) { 480 /* skb->data does fit so embed */ 481 embedded_bytes = skb->len; 482 } 483 484 /* 485 * Since the send occurs asynchronously, we set the count to one 486 * and begin sending. Any sends that happen to complete before 487 * we are done sending will not free the skb. We will be left 488 * with that task during exit. This also handles the case of 489 * a packet destined for a partition which is no longer up. 490 */ 491 atomic_set(&queued_msg->use_count, 1); 492 queued_msg->skb = skb; 493 494 second_mac_octet = skb->data[XPNET_PARTID_OCTET]; 495 if (second_mac_octet == 0xff) { 496 /* we are being asked to broadcast to all partitions */ 497 dp = xpnet_broadcast_partitions; 498 } else if (second_mac_octet != 0) { 499 dp = xpnet_broadcast_partitions & 500 (1UL << (second_mac_octet - 1)); 501 } else { 502 /* 0 is an invalid partid. Ignore */ 503 dp = 0; 504 } 505 dev_dbg(xpnet, "destination Partitions mask (dp) = 0x%lx\n", dp); 506 507 /* 508 * If we wanted to allow promiscuous mode to work like an 509 * unswitched network, this would be a good point to OR in a 510 * mask of partitions which should be receiving all packets. 511 */ 512 513 /* 514 * Main send loop. 515 */ 516 for (dest_partid = 1; dp && dest_partid < XP_MAX_PARTITIONS; 517 dest_partid++) { 518 519 if (!(dp & (1UL << (dest_partid - 1)))) { 520 /* not destined for this partition */ 521 continue; 522 } 523 524 /* remove this partition from the destinations mask */ 525 dp &= ~(1UL << (dest_partid - 1)); 526 527 /* found a partition to send to */ 528 529 ret = xpc_allocate(dest_partid, XPC_NET_CHANNEL, 530 XPC_NOWAIT, (void **)&msg); 531 if (unlikely(ret != xpcSuccess)) 532 continue; 533 534 msg->embedded_bytes = embedded_bytes; 535 if (unlikely(embedded_bytes != 0)) { 536 msg->version = XPNET_VERSION_EMBED; 537 dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n", 538 &msg->data, skb->data, (size_t)embedded_bytes); 539 skb_copy_from_linear_data(skb, &msg->data, 540 (size_t)embedded_bytes); 541 } else { 542 msg->version = XPNET_VERSION; 543 } 544 msg->magic = XPNET_MAGIC; 545 msg->size = end_addr - start_addr; 546 msg->leadin_ignore = (u64)skb->data - start_addr; 547 msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb); 548 msg->buf_pa = __pa(start_addr); 549 550 dev_dbg(xpnet, "sending XPC message to %d:%d\n" 551 KERN_DEBUG "msg->buf_pa=0x%lx, msg->size=%u, " 552 "msg->leadin_ignore=%u, msg->tailout_ignore=%u\n", 553 dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size, 554 msg->leadin_ignore, msg->tailout_ignore); 555 556 atomic_inc(&queued_msg->use_count); 557 558 ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, msg, 559 xpnet_send_completed, queued_msg); 560 if (unlikely(ret != xpcSuccess)) { 561 atomic_dec(&queued_msg->use_count); 562 continue; 563 } 564 } 565 566 if (atomic_dec_return(&queued_msg->use_count) == 0) { 567 dev_dbg(xpnet, "no partitions to receive packet destined for " 568 "%d\n", dest_partid); 569 570 dev_kfree_skb(skb); 571 kfree(queued_msg); 572 } 573 574 priv->stats.tx_packets++; 575 priv->stats.tx_bytes += skb->len; 576 577 return 0; 578} 579 580/* 581 * Deal with transmit timeouts coming from the network layer. 582 */ 583static void 584xpnet_dev_tx_timeout(struct net_device *dev) 585{ 586 struct xpnet_dev_private *priv; 587 588 priv = (struct xpnet_dev_private *)dev->priv; 589 590 priv->stats.tx_errors++; 591 return; 592} 593 594static int __init 595xpnet_init(void) 596{ 597 int i; 598 u32 license_num; 599 int result = -ENOMEM; 600 601 if (!ia64_platform_is("sn2")) 602 return -ENODEV; 603 604 dev_info(xpnet, "registering network device %s\n", XPNET_DEVICE_NAME); 605 606 /* 607 * use ether_setup() to init the majority of our device 608 * structure and then override the necessary pieces. 609 */ 610 xpnet_device = alloc_netdev(sizeof(struct xpnet_dev_private), 611 XPNET_DEVICE_NAME, ether_setup); 612 if (xpnet_device == NULL) 613 return -ENOMEM; 614 615 netif_carrier_off(xpnet_device); 616 617 xpnet_device->mtu = XPNET_DEF_MTU; 618 xpnet_device->change_mtu = xpnet_dev_change_mtu; 619 xpnet_device->open = xpnet_dev_open; 620 xpnet_device->get_stats = xpnet_dev_get_stats; 621 xpnet_device->stop = xpnet_dev_stop; 622 xpnet_device->hard_start_xmit = xpnet_dev_hard_start_xmit; 623 xpnet_device->tx_timeout = xpnet_dev_tx_timeout; 624 xpnet_device->set_config = xpnet_dev_set_config; 625 626 /* 627 * Multicast assumes the LSB of the first octet is set for multicast 628 * MAC addresses. We chose the first octet of the MAC to be unlikely 629 * to collide with any vendor's officially issued MAC. 630 */ 631 xpnet_device->dev_addr[0] = 0xfe; 632 xpnet_device->dev_addr[XPNET_PARTID_OCTET] = sn_partition_id; 633 license_num = sn_partition_serial_number_val(); 634 for (i = 3; i >= 0; i--) { 635 xpnet_device->dev_addr[XPNET_LICENSE_OCTET + i] = 636 license_num & 0xff; 637 license_num = license_num >> 8; 638 } 639 640 /* 641 * ether_setup() sets this to a multicast device. We are 642 * really not supporting multicast at this time. 643 */ 644 xpnet_device->flags &= ~IFF_MULTICAST; 645 646 /* 647 * No need to checksum as it is a DMA transfer. The BTE will 648 * report an error if the data is not retrievable and the 649 * packet will be dropped. 650 */ 651 xpnet_device->features = NETIF_F_NO_CSUM; 652 653 result = register_netdev(xpnet_device); 654 if (result != 0) 655 free_netdev(xpnet_device); 656 657 return result; 658} 659 660module_init(xpnet_init); 661 662static void __exit 663xpnet_exit(void) 664{ 665 dev_info(xpnet, "unregistering network device %s\n", 666 xpnet_device[0].name); 667 668 unregister_netdev(xpnet_device); 669 670 free_netdev(xpnet_device); 671} 672 673module_exit(xpnet_exit); 674 675MODULE_AUTHOR("Silicon Graphics, Inc."); 676MODULE_DESCRIPTION("Cross Partition Network adapter (XPNET)"); 677MODULE_LICENSE("GPL"); 678