1 /* 2 * Virtual network driver for conversing with remote driver backends. 3 * 4 * Copyright (c) 2002-2005, K A Fraser 5 * Copyright (c) 2005, XenSource Ltd 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 2 9 * as published by the Free Software Foundation; or, when distributed 10 * separately from the Linux kernel or incorporated into other 11 * software packages, subject to the following license: 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this source file (the "Software"), to deal in the Software without 15 * restriction, including without limitation the rights to use, copy, modify, 16 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, subject to 18 * the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29 * IN THE SOFTWARE. 30 */ 31 32 #include <linux/module.h> 33 #include <linux/kernel.h> 34 #include <linux/netdevice.h> 35 #include <linux/etherdevice.h> 36 #include <linux/skbuff.h> 37 #include <linux/ethtool.h> 38 #include <linux/if_ether.h> 39 #include <linux/tcp.h> 40 #include <linux/udp.h> 41 #include <linux/moduleparam.h> 42 #include <linux/mm.h> 43 #include <net/ip.h> 44 45 #include <xen/xen.h> 46 #include <xen/xenbus.h> 47 #include <xen/events.h> 48 #include <xen/page.h> 49 #include <xen/grant_table.h> 50 51 #include <xen/interface/io/netif.h> 52 #include <xen/interface/memory.h> 53 #include <xen/interface/grant_table.h> 54 55 static const struct ethtool_ops xennet_ethtool_ops; 56 57 struct netfront_cb { 58 struct page *page; 59 unsigned offset; 60 }; 61 62 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 63 64 #define RX_COPY_THRESHOLD 256 65 66 #define GRANT_INVALID_REF 0 67 68 #define NET_TX_RING_SIZE __RING_SIZE((struct xen_netif_tx_sring *)0, PAGE_SIZE) 69 #define NET_RX_RING_SIZE __RING_SIZE((struct xen_netif_rx_sring *)0, PAGE_SIZE) 70 #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) 71 72 struct netfront_info { 73 struct list_head list; 74 struct net_device *netdev; 75 76 struct napi_struct napi; 77 78 unsigned int evtchn; 79 struct xenbus_device *xbdev; 80 81 spinlock_t tx_lock; 82 struct xen_netif_tx_front_ring tx; 83 int tx_ring_ref; 84 85 /* 86 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 87 * are linked from tx_skb_freelist through skb_entry.link. 88 * 89 * NB. Freelist index entries are always going to be less than 90 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 91 * greater than PAGE_OFFSET: we use this property to distinguish 92 * them. 93 */ 94 union skb_entry { 95 struct sk_buff *skb; 96 unsigned long link; 97 } tx_skbs[NET_TX_RING_SIZE]; 98 grant_ref_t gref_tx_head; 99 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 100 unsigned tx_skb_freelist; 101 102 spinlock_t rx_lock ____cacheline_aligned_in_smp; 103 struct xen_netif_rx_front_ring rx; 104 int rx_ring_ref; 105 106 /* Receive-ring batched refills. */ 107 #define RX_MIN_TARGET 8 108 #define RX_DFL_MIN_TARGET 64 109 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) 110 unsigned rx_min_target, rx_max_target, rx_target; 111 struct sk_buff_head rx_batch; 112 113 struct timer_list rx_refill_timer; 114 115 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 116 grant_ref_t gref_rx_head; 117 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 118 119 unsigned long rx_pfn_array[NET_RX_RING_SIZE]; 120 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; 121 struct mmu_update rx_mmu[NET_RX_RING_SIZE]; 122 }; 123 124 struct netfront_rx_info { 125 struct xen_netif_rx_response rx; 126 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 127 }; 128 129 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 130 { 131 list->link = id; 132 } 133 134 static int skb_entry_is_link(const union skb_entry *list) 135 { 136 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 137 return ((unsigned long)list->skb < PAGE_OFFSET); 138 } 139 140 /* 141 * Access macros for acquiring freeing slots in tx_skbs[]. 142 */ 143 144 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 145 unsigned short id) 146 { 147 skb_entry_set_link(&list[id], *head); 148 *head = id; 149 } 150 151 static unsigned short get_id_from_freelist(unsigned *head, 152 union skb_entry *list) 153 { 154 unsigned int id = *head; 155 *head = list[id].link; 156 return id; 157 } 158 159 static int xennet_rxidx(RING_IDX idx) 160 { 161 return idx & (NET_RX_RING_SIZE - 1); 162 } 163 164 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np, 165 RING_IDX ri) 166 { 167 int i = xennet_rxidx(ri); 168 struct sk_buff *skb = np->rx_skbs[i]; 169 np->rx_skbs[i] = NULL; 170 return skb; 171 } 172 173 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np, 174 RING_IDX ri) 175 { 176 int i = xennet_rxidx(ri); 177 grant_ref_t ref = np->grant_rx_ref[i]; 178 np->grant_rx_ref[i] = GRANT_INVALID_REF; 179 return ref; 180 } 181 182 #ifdef CONFIG_SYSFS 183 static int xennet_sysfs_addif(struct net_device *netdev); 184 static void xennet_sysfs_delif(struct net_device *netdev); 185 #else /* !CONFIG_SYSFS */ 186 #define xennet_sysfs_addif(dev) (0) 187 #define xennet_sysfs_delif(dev) do { } while (0) 188 #endif 189 190 static int xennet_can_sg(struct net_device *dev) 191 { 192 return dev->features & NETIF_F_SG; 193 } 194 195 196 static void rx_refill_timeout(unsigned long data) 197 { 198 struct net_device *dev = (struct net_device *)data; 199 struct netfront_info *np = netdev_priv(dev); 200 napi_schedule(&np->napi); 201 } 202 203 static int netfront_tx_slot_available(struct netfront_info *np) 204 { 205 return ((np->tx.req_prod_pvt - np->tx.rsp_cons) < 206 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2)); 207 } 208 209 static void xennet_maybe_wake_tx(struct net_device *dev) 210 { 211 struct netfront_info *np = netdev_priv(dev); 212 213 if (unlikely(netif_queue_stopped(dev)) && 214 netfront_tx_slot_available(np) && 215 likely(netif_running(dev))) 216 netif_wake_queue(dev); 217 } 218 219 static void xennet_alloc_rx_buffers(struct net_device *dev) 220 { 221 unsigned short id; 222 struct netfront_info *np = netdev_priv(dev); 223 struct sk_buff *skb; 224 struct page *page; 225 int i, batch_target, notify; 226 RING_IDX req_prod = np->rx.req_prod_pvt; 227 grant_ref_t ref; 228 unsigned long pfn; 229 void *vaddr; 230 struct xen_netif_rx_request *req; 231 232 if (unlikely(!netif_carrier_ok(dev))) 233 return; 234 235 /* 236 * Allocate skbuffs greedily, even though we batch updates to the 237 * receive ring. This creates a less bursty demand on the memory 238 * allocator, so should reduce the chance of failed allocation requests 239 * both for ourself and for other kernel subsystems. 240 */ 241 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); 242 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { 243 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, 244 GFP_ATOMIC | __GFP_NOWARN); 245 if (unlikely(!skb)) 246 goto no_skb; 247 248 /* Align ip header to a 16 bytes boundary */ 249 skb_reserve(skb, NET_IP_ALIGN); 250 251 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 252 if (!page) { 253 kfree_skb(skb); 254 no_skb: 255 /* Any skbuffs queued for refill? Force them out. */ 256 if (i != 0) 257 goto refill; 258 /* Could not allocate any skbuffs. Try again later. */ 259 mod_timer(&np->rx_refill_timer, 260 jiffies + (HZ/10)); 261 break; 262 } 263 264 skb_shinfo(skb)->frags[0].page = page; 265 skb_shinfo(skb)->nr_frags = 1; 266 __skb_queue_tail(&np->rx_batch, skb); 267 } 268 269 /* Is the batch large enough to be worthwhile? */ 270 if (i < (np->rx_target/2)) { 271 if (req_prod > np->rx.sring->req_prod) 272 goto push; 273 return; 274 } 275 276 /* Adjust our fill target if we risked running out of buffers. */ 277 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && 278 ((np->rx_target *= 2) > np->rx_max_target)) 279 np->rx_target = np->rx_max_target; 280 281 refill: 282 for (i = 0; ; i++) { 283 skb = __skb_dequeue(&np->rx_batch); 284 if (skb == NULL) 285 break; 286 287 skb->dev = dev; 288 289 id = xennet_rxidx(req_prod + i); 290 291 BUG_ON(np->rx_skbs[id]); 292 np->rx_skbs[id] = skb; 293 294 ref = gnttab_claim_grant_reference(&np->gref_rx_head); 295 BUG_ON((signed short)ref < 0); 296 np->grant_rx_ref[id] = ref; 297 298 pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page); 299 vaddr = page_address(skb_shinfo(skb)->frags[0].page); 300 301 req = RING_GET_REQUEST(&np->rx, req_prod + i); 302 gnttab_grant_foreign_access_ref(ref, 303 np->xbdev->otherend_id, 304 pfn_to_mfn(pfn), 305 0); 306 307 req->id = id; 308 req->gref = ref; 309 } 310 311 wmb(); /* barrier so backend seens requests */ 312 313 /* Above is a suitable barrier to ensure backend will see requests. */ 314 np->rx.req_prod_pvt = req_prod + i; 315 push: 316 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); 317 if (notify) 318 notify_remote_via_irq(np->netdev->irq); 319 } 320 321 static int xennet_open(struct net_device *dev) 322 { 323 struct netfront_info *np = netdev_priv(dev); 324 325 napi_enable(&np->napi); 326 327 spin_lock_bh(&np->rx_lock); 328 if (netif_carrier_ok(dev)) { 329 xennet_alloc_rx_buffers(dev); 330 np->rx.sring->rsp_event = np->rx.rsp_cons + 1; 331 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) 332 napi_schedule(&np->napi); 333 } 334 spin_unlock_bh(&np->rx_lock); 335 336 netif_start_queue(dev); 337 338 return 0; 339 } 340 341 static void xennet_tx_buf_gc(struct net_device *dev) 342 { 343 RING_IDX cons, prod; 344 unsigned short id; 345 struct netfront_info *np = netdev_priv(dev); 346 struct sk_buff *skb; 347 348 BUG_ON(!netif_carrier_ok(dev)); 349 350 do { 351 prod = np->tx.sring->rsp_prod; 352 rmb(); /* Ensure we see responses up to 'rp'. */ 353 354 for (cons = np->tx.rsp_cons; cons != prod; cons++) { 355 struct xen_netif_tx_response *txrsp; 356 357 txrsp = RING_GET_RESPONSE(&np->tx, cons); 358 if (txrsp->status == NETIF_RSP_NULL) 359 continue; 360 361 id = txrsp->id; 362 skb = np->tx_skbs[id].skb; 363 if (unlikely(gnttab_query_foreign_access( 364 np->grant_tx_ref[id]) != 0)) { 365 printk(KERN_ALERT "xennet_tx_buf_gc: warning " 366 "-- grant still in use by backend " 367 "domain.\n"); 368 BUG(); 369 } 370 gnttab_end_foreign_access_ref( 371 np->grant_tx_ref[id], GNTMAP_readonly); 372 gnttab_release_grant_reference( 373 &np->gref_tx_head, np->grant_tx_ref[id]); 374 np->grant_tx_ref[id] = GRANT_INVALID_REF; 375 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); 376 dev_kfree_skb_irq(skb); 377 } 378 379 np->tx.rsp_cons = prod; 380 381 /* 382 * Set a new event, then check for race with update of tx_cons. 383 * Note that it is essential to schedule a callback, no matter 384 * how few buffers are pending. Even if there is space in the 385 * transmit ring, higher layers may be blocked because too much 386 * data is outstanding: in such cases notification from Xen is 387 * likely to be the only kick that we'll get. 388 */ 389 np->tx.sring->rsp_event = 390 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1; 391 mb(); /* update shared area */ 392 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); 393 394 xennet_maybe_wake_tx(dev); 395 } 396 397 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, 398 struct xen_netif_tx_request *tx) 399 { 400 struct netfront_info *np = netdev_priv(dev); 401 char *data = skb->data; 402 unsigned long mfn; 403 RING_IDX prod = np->tx.req_prod_pvt; 404 int frags = skb_shinfo(skb)->nr_frags; 405 unsigned int offset = offset_in_page(data); 406 unsigned int len = skb_headlen(skb); 407 unsigned int id; 408 grant_ref_t ref; 409 int i; 410 411 /* While the header overlaps a page boundary (including being 412 larger than a page), split it it into page-sized chunks. */ 413 while (len > PAGE_SIZE - offset) { 414 tx->size = PAGE_SIZE - offset; 415 tx->flags |= NETTXF_more_data; 416 len -= tx->size; 417 data += tx->size; 418 offset = 0; 419 420 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 421 np->tx_skbs[id].skb = skb_get(skb); 422 tx = RING_GET_REQUEST(&np->tx, prod++); 423 tx->id = id; 424 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 425 BUG_ON((signed short)ref < 0); 426 427 mfn = virt_to_mfn(data); 428 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, 429 mfn, GNTMAP_readonly); 430 431 tx->gref = np->grant_tx_ref[id] = ref; 432 tx->offset = offset; 433 tx->size = len; 434 tx->flags = 0; 435 } 436 437 /* Grant backend access to each skb fragment page. */ 438 for (i = 0; i < frags; i++) { 439 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 440 441 tx->flags |= NETTXF_more_data; 442 443 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 444 np->tx_skbs[id].skb = skb_get(skb); 445 tx = RING_GET_REQUEST(&np->tx, prod++); 446 tx->id = id; 447 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 448 BUG_ON((signed short)ref < 0); 449 450 mfn = pfn_to_mfn(page_to_pfn(frag->page)); 451 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, 452 mfn, GNTMAP_readonly); 453 454 tx->gref = np->grant_tx_ref[id] = ref; 455 tx->offset = frag->page_offset; 456 tx->size = frag->size; 457 tx->flags = 0; 458 } 459 460 np->tx.req_prod_pvt = prod; 461 } 462 463 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 464 { 465 unsigned short id; 466 struct netfront_info *np = netdev_priv(dev); 467 struct xen_netif_tx_request *tx; 468 struct xen_netif_extra_info *extra; 469 char *data = skb->data; 470 RING_IDX i; 471 grant_ref_t ref; 472 unsigned long mfn; 473 int notify; 474 int frags = skb_shinfo(skb)->nr_frags; 475 unsigned int offset = offset_in_page(data); 476 unsigned int len = skb_headlen(skb); 477 478 frags += DIV_ROUND_UP(offset + len, PAGE_SIZE); 479 if (unlikely(frags > MAX_SKB_FRAGS + 1)) { 480 printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n", 481 frags); 482 dump_stack(); 483 goto drop; 484 } 485 486 spin_lock_irq(&np->tx_lock); 487 488 if (unlikely(!netif_carrier_ok(dev) || 489 (frags > 1 && !xennet_can_sg(dev)) || 490 netif_needs_gso(dev, skb))) { 491 spin_unlock_irq(&np->tx_lock); 492 goto drop; 493 } 494 495 i = np->tx.req_prod_pvt; 496 497 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 498 np->tx_skbs[id].skb = skb; 499 500 tx = RING_GET_REQUEST(&np->tx, i); 501 502 tx->id = id; 503 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 504 BUG_ON((signed short)ref < 0); 505 mfn = virt_to_mfn(data); 506 gnttab_grant_foreign_access_ref( 507 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); 508 tx->gref = np->grant_tx_ref[id] = ref; 509 tx->offset = offset; 510 tx->size = len; 511 extra = NULL; 512 513 tx->flags = 0; 514 if (skb->ip_summed == CHECKSUM_PARTIAL) 515 /* local packet? */ 516 tx->flags |= NETTXF_csum_blank | NETTXF_data_validated; 517 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 518 /* remote but checksummed. */ 519 tx->flags |= NETTXF_data_validated; 520 521 if (skb_shinfo(skb)->gso_size) { 522 struct xen_netif_extra_info *gso; 523 524 gso = (struct xen_netif_extra_info *) 525 RING_GET_REQUEST(&np->tx, ++i); 526 527 if (extra) 528 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE; 529 else 530 tx->flags |= NETTXF_extra_info; 531 532 gso->u.gso.size = skb_shinfo(skb)->gso_size; 533 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; 534 gso->u.gso.pad = 0; 535 gso->u.gso.features = 0; 536 537 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 538 gso->flags = 0; 539 extra = gso; 540 } 541 542 np->tx.req_prod_pvt = i + 1; 543 544 xennet_make_frags(skb, dev, tx); 545 tx->size = skb->len; 546 547 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); 548 if (notify) 549 notify_remote_via_irq(np->netdev->irq); 550 551 dev->stats.tx_bytes += skb->len; 552 dev->stats.tx_packets++; 553 554 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 555 xennet_tx_buf_gc(dev); 556 557 if (!netfront_tx_slot_available(np)) 558 netif_stop_queue(dev); 559 560 spin_unlock_irq(&np->tx_lock); 561 562 return NETDEV_TX_OK; 563 564 drop: 565 dev->stats.tx_dropped++; 566 dev_kfree_skb(skb); 567 return NETDEV_TX_OK; 568 } 569 570 static int xennet_close(struct net_device *dev) 571 { 572 struct netfront_info *np = netdev_priv(dev); 573 netif_stop_queue(np->netdev); 574 napi_disable(&np->napi); 575 return 0; 576 } 577 578 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb, 579 grant_ref_t ref) 580 { 581 int new = xennet_rxidx(np->rx.req_prod_pvt); 582 583 BUG_ON(np->rx_skbs[new]); 584 np->rx_skbs[new] = skb; 585 np->grant_rx_ref[new] = ref; 586 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new; 587 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref; 588 np->rx.req_prod_pvt++; 589 } 590 591 static int xennet_get_extras(struct netfront_info *np, 592 struct xen_netif_extra_info *extras, 593 RING_IDX rp) 594 595 { 596 struct xen_netif_extra_info *extra; 597 struct device *dev = &np->netdev->dev; 598 RING_IDX cons = np->rx.rsp_cons; 599 int err = 0; 600 601 do { 602 struct sk_buff *skb; 603 grant_ref_t ref; 604 605 if (unlikely(cons + 1 == rp)) { 606 if (net_ratelimit()) 607 dev_warn(dev, "Missing extra info\n"); 608 err = -EBADR; 609 break; 610 } 611 612 extra = (struct xen_netif_extra_info *) 613 RING_GET_RESPONSE(&np->rx, ++cons); 614 615 if (unlikely(!extra->type || 616 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 617 if (net_ratelimit()) 618 dev_warn(dev, "Invalid extra type: %d\n", 619 extra->type); 620 err = -EINVAL; 621 } else { 622 memcpy(&extras[extra->type - 1], extra, 623 sizeof(*extra)); 624 } 625 626 skb = xennet_get_rx_skb(np, cons); 627 ref = xennet_get_rx_ref(np, cons); 628 xennet_move_rx_slot(np, skb, ref); 629 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 630 631 np->rx.rsp_cons = cons; 632 return err; 633 } 634 635 static int xennet_get_responses(struct netfront_info *np, 636 struct netfront_rx_info *rinfo, RING_IDX rp, 637 struct sk_buff_head *list) 638 { 639 struct xen_netif_rx_response *rx = &rinfo->rx; 640 struct xen_netif_extra_info *extras = rinfo->extras; 641 struct device *dev = &np->netdev->dev; 642 RING_IDX cons = np->rx.rsp_cons; 643 struct sk_buff *skb = xennet_get_rx_skb(np, cons); 644 grant_ref_t ref = xennet_get_rx_ref(np, cons); 645 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 646 int frags = 1; 647 int err = 0; 648 unsigned long ret; 649 650 if (rx->flags & NETRXF_extra_info) { 651 err = xennet_get_extras(np, extras, rp); 652 cons = np->rx.rsp_cons; 653 } 654 655 for (;;) { 656 if (unlikely(rx->status < 0 || 657 rx->offset + rx->status > PAGE_SIZE)) { 658 if (net_ratelimit()) 659 dev_warn(dev, "rx->offset: %x, size: %u\n", 660 rx->offset, rx->status); 661 xennet_move_rx_slot(np, skb, ref); 662 err = -EINVAL; 663 goto next; 664 } 665 666 /* 667 * This definitely indicates a bug, either in this driver or in 668 * the backend driver. In future this should flag the bad 669 * situation to the system controller to reboot the backed. 670 */ 671 if (ref == GRANT_INVALID_REF) { 672 if (net_ratelimit()) 673 dev_warn(dev, "Bad rx response id %d.\n", 674 rx->id); 675 err = -EINVAL; 676 goto next; 677 } 678 679 ret = gnttab_end_foreign_access_ref(ref, 0); 680 BUG_ON(!ret); 681 682 gnttab_release_grant_reference(&np->gref_rx_head, ref); 683 684 __skb_queue_tail(list, skb); 685 686 next: 687 if (!(rx->flags & NETRXF_more_data)) 688 break; 689 690 if (cons + frags == rp) { 691 if (net_ratelimit()) 692 dev_warn(dev, "Need more frags\n"); 693 err = -ENOENT; 694 break; 695 } 696 697 rx = RING_GET_RESPONSE(&np->rx, cons + frags); 698 skb = xennet_get_rx_skb(np, cons + frags); 699 ref = xennet_get_rx_ref(np, cons + frags); 700 frags++; 701 } 702 703 if (unlikely(frags > max)) { 704 if (net_ratelimit()) 705 dev_warn(dev, "Too many frags\n"); 706 err = -E2BIG; 707 } 708 709 if (unlikely(err)) 710 np->rx.rsp_cons = cons + frags; 711 712 return err; 713 } 714 715 static int xennet_set_skb_gso(struct sk_buff *skb, 716 struct xen_netif_extra_info *gso) 717 { 718 if (!gso->u.gso.size) { 719 if (net_ratelimit()) 720 printk(KERN_WARNING "GSO size must not be zero.\n"); 721 return -EINVAL; 722 } 723 724 /* Currently only TCPv4 S.O. is supported. */ 725 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) { 726 if (net_ratelimit()) 727 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type); 728 return -EINVAL; 729 } 730 731 skb_shinfo(skb)->gso_size = gso->u.gso.size; 732 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 733 734 /* Header must be checked, and gso_segs computed. */ 735 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 736 skb_shinfo(skb)->gso_segs = 0; 737 738 return 0; 739 } 740 741 static RING_IDX xennet_fill_frags(struct netfront_info *np, 742 struct sk_buff *skb, 743 struct sk_buff_head *list) 744 { 745 struct skb_shared_info *shinfo = skb_shinfo(skb); 746 int nr_frags = shinfo->nr_frags; 747 RING_IDX cons = np->rx.rsp_cons; 748 skb_frag_t *frag = shinfo->frags + nr_frags; 749 struct sk_buff *nskb; 750 751 while ((nskb = __skb_dequeue(list))) { 752 struct xen_netif_rx_response *rx = 753 RING_GET_RESPONSE(&np->rx, ++cons); 754 755 frag->page = skb_shinfo(nskb)->frags[0].page; 756 frag->page_offset = rx->offset; 757 frag->size = rx->status; 758 759 skb->data_len += rx->status; 760 761 skb_shinfo(nskb)->nr_frags = 0; 762 kfree_skb(nskb); 763 764 frag++; 765 nr_frags++; 766 } 767 768 shinfo->nr_frags = nr_frags; 769 return cons; 770 } 771 772 static int skb_checksum_setup(struct sk_buff *skb) 773 { 774 struct iphdr *iph; 775 unsigned char *th; 776 int err = -EPROTO; 777 778 if (skb->protocol != htons(ETH_P_IP)) 779 goto out; 780 781 iph = (void *)skb->data; 782 th = skb->data + 4 * iph->ihl; 783 if (th >= skb_tail_pointer(skb)) 784 goto out; 785 786 skb->csum_start = th - skb->head; 787 switch (iph->protocol) { 788 case IPPROTO_TCP: 789 skb->csum_offset = offsetof(struct tcphdr, check); 790 break; 791 case IPPROTO_UDP: 792 skb->csum_offset = offsetof(struct udphdr, check); 793 break; 794 default: 795 if (net_ratelimit()) 796 printk(KERN_ERR "Attempting to checksum a non-" 797 "TCP/UDP packet, dropping a protocol" 798 " %d packet", iph->protocol); 799 goto out; 800 } 801 802 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb)) 803 goto out; 804 805 err = 0; 806 807 out: 808 return err; 809 } 810 811 static int handle_incoming_queue(struct net_device *dev, 812 struct sk_buff_head *rxq) 813 { 814 int packets_dropped = 0; 815 struct sk_buff *skb; 816 817 while ((skb = __skb_dequeue(rxq)) != NULL) { 818 struct page *page = NETFRONT_SKB_CB(skb)->page; 819 void *vaddr = page_address(page); 820 unsigned offset = NETFRONT_SKB_CB(skb)->offset; 821 822 memcpy(skb->data, vaddr + offset, 823 skb_headlen(skb)); 824 825 if (page != skb_shinfo(skb)->frags[0].page) 826 __free_page(page); 827 828 /* Ethernet work: Delayed to here as it peeks the header. */ 829 skb->protocol = eth_type_trans(skb, dev); 830 831 if (skb->ip_summed == CHECKSUM_PARTIAL) { 832 if (skb_checksum_setup(skb)) { 833 kfree_skb(skb); 834 packets_dropped++; 835 dev->stats.rx_errors++; 836 continue; 837 } 838 } 839 840 dev->stats.rx_packets++; 841 dev->stats.rx_bytes += skb->len; 842 843 /* Pass it up. */ 844 netif_receive_skb(skb); 845 } 846 847 return packets_dropped; 848 } 849 850 static int xennet_poll(struct napi_struct *napi, int budget) 851 { 852 struct netfront_info *np = container_of(napi, struct netfront_info, napi); 853 struct net_device *dev = np->netdev; 854 struct sk_buff *skb; 855 struct netfront_rx_info rinfo; 856 struct xen_netif_rx_response *rx = &rinfo.rx; 857 struct xen_netif_extra_info *extras = rinfo.extras; 858 RING_IDX i, rp; 859 int work_done; 860 struct sk_buff_head rxq; 861 struct sk_buff_head errq; 862 struct sk_buff_head tmpq; 863 unsigned long flags; 864 unsigned int len; 865 int err; 866 867 spin_lock(&np->rx_lock); 868 869 skb_queue_head_init(&rxq); 870 skb_queue_head_init(&errq); 871 skb_queue_head_init(&tmpq); 872 873 rp = np->rx.sring->rsp_prod; 874 rmb(); /* Ensure we see queued responses up to 'rp'. */ 875 876 i = np->rx.rsp_cons; 877 work_done = 0; 878 while ((i != rp) && (work_done < budget)) { 879 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx)); 880 memset(extras, 0, sizeof(rinfo.extras)); 881 882 err = xennet_get_responses(np, &rinfo, rp, &tmpq); 883 884 if (unlikely(err)) { 885 err: 886 while ((skb = __skb_dequeue(&tmpq))) 887 __skb_queue_tail(&errq, skb); 888 dev->stats.rx_errors++; 889 i = np->rx.rsp_cons; 890 continue; 891 } 892 893 skb = __skb_dequeue(&tmpq); 894 895 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 896 struct xen_netif_extra_info *gso; 897 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 898 899 if (unlikely(xennet_set_skb_gso(skb, gso))) { 900 __skb_queue_head(&tmpq, skb); 901 np->rx.rsp_cons += skb_queue_len(&tmpq); 902 goto err; 903 } 904 } 905 906 NETFRONT_SKB_CB(skb)->page = skb_shinfo(skb)->frags[0].page; 907 NETFRONT_SKB_CB(skb)->offset = rx->offset; 908 909 len = rx->status; 910 if (len > RX_COPY_THRESHOLD) 911 len = RX_COPY_THRESHOLD; 912 skb_put(skb, len); 913 914 if (rx->status > len) { 915 skb_shinfo(skb)->frags[0].page_offset = 916 rx->offset + len; 917 skb_shinfo(skb)->frags[0].size = rx->status - len; 918 skb->data_len = rx->status - len; 919 } else { 920 skb_shinfo(skb)->frags[0].page = NULL; 921 skb_shinfo(skb)->nr_frags = 0; 922 } 923 924 i = xennet_fill_frags(np, skb, &tmpq); 925 926 /* 927 * Truesize approximates the size of true data plus 928 * any supervisor overheads. Adding hypervisor 929 * overheads has been shown to significantly reduce 930 * achievable bandwidth with the default receive 931 * buffer size. It is therefore not wise to account 932 * for it here. 933 * 934 * After alloc_skb(RX_COPY_THRESHOLD), truesize is set 935 * to RX_COPY_THRESHOLD + the supervisor 936 * overheads. Here, we add the size of the data pulled 937 * in xennet_fill_frags(). 938 * 939 * We also adjust for any unused space in the main 940 * data area by subtracting (RX_COPY_THRESHOLD - 941 * len). This is especially important with drivers 942 * which split incoming packets into header and data, 943 * using only 66 bytes of the main data area (see the 944 * e1000 driver for example.) On such systems, 945 * without this last adjustement, our achievable 946 * receive throughout using the standard receive 947 * buffer size was cut by 25%(!!!). 948 */ 949 skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len); 950 skb->len += skb->data_len; 951 952 if (rx->flags & NETRXF_csum_blank) 953 skb->ip_summed = CHECKSUM_PARTIAL; 954 else if (rx->flags & NETRXF_data_validated) 955 skb->ip_summed = CHECKSUM_UNNECESSARY; 956 957 __skb_queue_tail(&rxq, skb); 958 959 np->rx.rsp_cons = ++i; 960 work_done++; 961 } 962 963 __skb_queue_purge(&errq); 964 965 work_done -= handle_incoming_queue(dev, &rxq); 966 967 /* If we get a callback with very few responses, reduce fill target. */ 968 /* NB. Note exponential increase, linear decrease. */ 969 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > 970 ((3*np->rx_target) / 4)) && 971 (--np->rx_target < np->rx_min_target)) 972 np->rx_target = np->rx_min_target; 973 974 xennet_alloc_rx_buffers(dev); 975 976 if (work_done < budget) { 977 int more_to_do = 0; 978 979 local_irq_save(flags); 980 981 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); 982 if (!more_to_do) 983 __napi_complete(napi); 984 985 local_irq_restore(flags); 986 } 987 988 spin_unlock(&np->rx_lock); 989 990 return work_done; 991 } 992 993 static int xennet_change_mtu(struct net_device *dev, int mtu) 994 { 995 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN; 996 997 if (mtu > max) 998 return -EINVAL; 999 dev->mtu = mtu; 1000 return 0; 1001 } 1002 1003 static void xennet_release_tx_bufs(struct netfront_info *np) 1004 { 1005 struct sk_buff *skb; 1006 int i; 1007 1008 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1009 /* Skip over entries which are actually freelist references */ 1010 if (skb_entry_is_link(&np->tx_skbs[i])) 1011 continue; 1012 1013 skb = np->tx_skbs[i].skb; 1014 gnttab_end_foreign_access_ref(np->grant_tx_ref[i], 1015 GNTMAP_readonly); 1016 gnttab_release_grant_reference(&np->gref_tx_head, 1017 np->grant_tx_ref[i]); 1018 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1019 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); 1020 dev_kfree_skb_irq(skb); 1021 } 1022 } 1023 1024 static void xennet_release_rx_bufs(struct netfront_info *np) 1025 { 1026 struct mmu_update *mmu = np->rx_mmu; 1027 struct multicall_entry *mcl = np->rx_mcl; 1028 struct sk_buff_head free_list; 1029 struct sk_buff *skb; 1030 unsigned long mfn; 1031 int xfer = 0, noxfer = 0, unused = 0; 1032 int id, ref; 1033 1034 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n", 1035 __func__); 1036 return; 1037 1038 skb_queue_head_init(&free_list); 1039 1040 spin_lock_bh(&np->rx_lock); 1041 1042 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1043 ref = np->grant_rx_ref[id]; 1044 if (ref == GRANT_INVALID_REF) { 1045 unused++; 1046 continue; 1047 } 1048 1049 skb = np->rx_skbs[id]; 1050 mfn = gnttab_end_foreign_transfer_ref(ref); 1051 gnttab_release_grant_reference(&np->gref_rx_head, ref); 1052 np->grant_rx_ref[id] = GRANT_INVALID_REF; 1053 1054 if (0 == mfn) { 1055 skb_shinfo(skb)->nr_frags = 0; 1056 dev_kfree_skb(skb); 1057 noxfer++; 1058 continue; 1059 } 1060 1061 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 1062 /* Remap the page. */ 1063 struct page *page = skb_shinfo(skb)->frags[0].page; 1064 unsigned long pfn = page_to_pfn(page); 1065 void *vaddr = page_address(page); 1066 1067 MULTI_update_va_mapping(mcl, (unsigned long)vaddr, 1068 mfn_pte(mfn, PAGE_KERNEL), 1069 0); 1070 mcl++; 1071 mmu->ptr = ((u64)mfn << PAGE_SHIFT) 1072 | MMU_MACHPHYS_UPDATE; 1073 mmu->val = pfn; 1074 mmu++; 1075 1076 set_phys_to_machine(pfn, mfn); 1077 } 1078 __skb_queue_tail(&free_list, skb); 1079 xfer++; 1080 } 1081 1082 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n", 1083 __func__, xfer, noxfer, unused); 1084 1085 if (xfer) { 1086 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 1087 /* Do all the remapping work and M2P updates. */ 1088 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu, 1089 NULL, DOMID_SELF); 1090 mcl++; 1091 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl); 1092 } 1093 } 1094 1095 __skb_queue_purge(&free_list); 1096 1097 spin_unlock_bh(&np->rx_lock); 1098 } 1099 1100 static void xennet_uninit(struct net_device *dev) 1101 { 1102 struct netfront_info *np = netdev_priv(dev); 1103 xennet_release_tx_bufs(np); 1104 xennet_release_rx_bufs(np); 1105 gnttab_free_grant_references(np->gref_tx_head); 1106 gnttab_free_grant_references(np->gref_rx_head); 1107 } 1108 1109 static const struct net_device_ops xennet_netdev_ops = { 1110 .ndo_open = xennet_open, 1111 .ndo_uninit = xennet_uninit, 1112 .ndo_stop = xennet_close, 1113 .ndo_start_xmit = xennet_start_xmit, 1114 .ndo_change_mtu = xennet_change_mtu, 1115 .ndo_set_mac_address = eth_mac_addr, 1116 .ndo_validate_addr = eth_validate_addr, 1117 }; 1118 1119 static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev) 1120 { 1121 int i, err; 1122 struct net_device *netdev; 1123 struct netfront_info *np; 1124 1125 netdev = alloc_etherdev(sizeof(struct netfront_info)); 1126 if (!netdev) { 1127 printk(KERN_WARNING "%s> alloc_etherdev failed.\n", 1128 __func__); 1129 return ERR_PTR(-ENOMEM); 1130 } 1131 1132 np = netdev_priv(netdev); 1133 np->xbdev = dev; 1134 1135 spin_lock_init(&np->tx_lock); 1136 spin_lock_init(&np->rx_lock); 1137 1138 skb_queue_head_init(&np->rx_batch); 1139 np->rx_target = RX_DFL_MIN_TARGET; 1140 np->rx_min_target = RX_DFL_MIN_TARGET; 1141 np->rx_max_target = RX_MAX_TARGET; 1142 1143 init_timer(&np->rx_refill_timer); 1144 np->rx_refill_timer.data = (unsigned long)netdev; 1145 np->rx_refill_timer.function = rx_refill_timeout; 1146 1147 /* Initialise tx_skbs as a free chain containing every entry. */ 1148 np->tx_skb_freelist = 0; 1149 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1150 skb_entry_set_link(&np->tx_skbs[i], i+1); 1151 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1152 } 1153 1154 /* Clear out rx_skbs */ 1155 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1156 np->rx_skbs[i] = NULL; 1157 np->grant_rx_ref[i] = GRANT_INVALID_REF; 1158 } 1159 1160 /* A grant for every tx ring slot */ 1161 if (gnttab_alloc_grant_references(TX_MAX_TARGET, 1162 &np->gref_tx_head) < 0) { 1163 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n"); 1164 err = -ENOMEM; 1165 goto exit; 1166 } 1167 /* A grant for every rx ring slot */ 1168 if (gnttab_alloc_grant_references(RX_MAX_TARGET, 1169 &np->gref_rx_head) < 0) { 1170 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n"); 1171 err = -ENOMEM; 1172 goto exit_free_tx; 1173 } 1174 1175 netdev->netdev_ops = &xennet_netdev_ops; 1176 1177 netif_napi_add(netdev, &np->napi, xennet_poll, 64); 1178 netdev->features = NETIF_F_IP_CSUM; 1179 1180 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); 1181 SET_NETDEV_DEV(netdev, &dev->dev); 1182 1183 np->netdev = netdev; 1184 1185 netif_carrier_off(netdev); 1186 1187 return netdev; 1188 1189 exit_free_tx: 1190 gnttab_free_grant_references(np->gref_tx_head); 1191 exit: 1192 free_netdev(netdev); 1193 return ERR_PTR(err); 1194 } 1195 1196 /** 1197 * Entry point to this code when a new device is created. Allocate the basic 1198 * structures and the ring buffers for communication with the backend, and 1199 * inform the backend of the appropriate details for those. 1200 */ 1201 static int __devinit netfront_probe(struct xenbus_device *dev, 1202 const struct xenbus_device_id *id) 1203 { 1204 int err; 1205 struct net_device *netdev; 1206 struct netfront_info *info; 1207 1208 netdev = xennet_create_dev(dev); 1209 if (IS_ERR(netdev)) { 1210 err = PTR_ERR(netdev); 1211 xenbus_dev_fatal(dev, err, "creating netdev"); 1212 return err; 1213 } 1214 1215 info = netdev_priv(netdev); 1216 dev_set_drvdata(&dev->dev, info); 1217 1218 err = register_netdev(info->netdev); 1219 if (err) { 1220 printk(KERN_WARNING "%s: register_netdev err=%d\n", 1221 __func__, err); 1222 goto fail; 1223 } 1224 1225 err = xennet_sysfs_addif(info->netdev); 1226 if (err) { 1227 unregister_netdev(info->netdev); 1228 printk(KERN_WARNING "%s: add sysfs failed err=%d\n", 1229 __func__, err); 1230 goto fail; 1231 } 1232 1233 return 0; 1234 1235 fail: 1236 free_netdev(netdev); 1237 dev_set_drvdata(&dev->dev, NULL); 1238 return err; 1239 } 1240 1241 static void xennet_end_access(int ref, void *page) 1242 { 1243 /* This frees the page as a side-effect */ 1244 if (ref != GRANT_INVALID_REF) 1245 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1246 } 1247 1248 static void xennet_disconnect_backend(struct netfront_info *info) 1249 { 1250 /* Stop old i/f to prevent errors whilst we rebuild the state. */ 1251 spin_lock_bh(&info->rx_lock); 1252 spin_lock_irq(&info->tx_lock); 1253 netif_carrier_off(info->netdev); 1254 spin_unlock_irq(&info->tx_lock); 1255 spin_unlock_bh(&info->rx_lock); 1256 1257 if (info->netdev->irq) 1258 unbind_from_irqhandler(info->netdev->irq, info->netdev); 1259 info->evtchn = info->netdev->irq = 0; 1260 1261 /* End access and free the pages */ 1262 xennet_end_access(info->tx_ring_ref, info->tx.sring); 1263 xennet_end_access(info->rx_ring_ref, info->rx.sring); 1264 1265 info->tx_ring_ref = GRANT_INVALID_REF; 1266 info->rx_ring_ref = GRANT_INVALID_REF; 1267 info->tx.sring = NULL; 1268 info->rx.sring = NULL; 1269 } 1270 1271 /** 1272 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1273 * driver restart. We tear down our netif structure and recreate it, but 1274 * leave the device-layer structures intact so that this is transparent to the 1275 * rest of the kernel. 1276 */ 1277 static int netfront_resume(struct xenbus_device *dev) 1278 { 1279 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1280 1281 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1282 1283 xennet_disconnect_backend(info); 1284 return 0; 1285 } 1286 1287 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1288 { 1289 char *s, *e, *macstr; 1290 int i; 1291 1292 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1293 if (IS_ERR(macstr)) 1294 return PTR_ERR(macstr); 1295 1296 for (i = 0; i < ETH_ALEN; i++) { 1297 mac[i] = simple_strtoul(s, &e, 16); 1298 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1299 kfree(macstr); 1300 return -ENOENT; 1301 } 1302 s = e+1; 1303 } 1304 1305 kfree(macstr); 1306 return 0; 1307 } 1308 1309 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1310 { 1311 struct net_device *dev = dev_id; 1312 struct netfront_info *np = netdev_priv(dev); 1313 unsigned long flags; 1314 1315 spin_lock_irqsave(&np->tx_lock, flags); 1316 1317 if (likely(netif_carrier_ok(dev))) { 1318 xennet_tx_buf_gc(dev); 1319 /* Under tx_lock: protects access to rx shared-ring indexes. */ 1320 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) 1321 napi_schedule(&np->napi); 1322 } 1323 1324 spin_unlock_irqrestore(&np->tx_lock, flags); 1325 1326 return IRQ_HANDLED; 1327 } 1328 1329 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) 1330 { 1331 struct xen_netif_tx_sring *txs; 1332 struct xen_netif_rx_sring *rxs; 1333 int err; 1334 struct net_device *netdev = info->netdev; 1335 1336 info->tx_ring_ref = GRANT_INVALID_REF; 1337 info->rx_ring_ref = GRANT_INVALID_REF; 1338 info->rx.sring = NULL; 1339 info->tx.sring = NULL; 1340 netdev->irq = 0; 1341 1342 err = xen_net_read_mac(dev, netdev->dev_addr); 1343 if (err) { 1344 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1345 goto fail; 1346 } 1347 1348 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1349 if (!txs) { 1350 err = -ENOMEM; 1351 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1352 goto fail; 1353 } 1354 SHARED_RING_INIT(txs); 1355 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE); 1356 1357 err = xenbus_grant_ring(dev, virt_to_mfn(txs)); 1358 if (err < 0) { 1359 free_page((unsigned long)txs); 1360 goto fail; 1361 } 1362 1363 info->tx_ring_ref = err; 1364 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1365 if (!rxs) { 1366 err = -ENOMEM; 1367 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1368 goto fail; 1369 } 1370 SHARED_RING_INIT(rxs); 1371 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE); 1372 1373 err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); 1374 if (err < 0) { 1375 free_page((unsigned long)rxs); 1376 goto fail; 1377 } 1378 info->rx_ring_ref = err; 1379 1380 err = xenbus_alloc_evtchn(dev, &info->evtchn); 1381 if (err) 1382 goto fail; 1383 1384 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt, 1385 IRQF_SAMPLE_RANDOM, netdev->name, 1386 netdev); 1387 if (err < 0) 1388 goto fail; 1389 netdev->irq = err; 1390 return 0; 1391 1392 fail: 1393 return err; 1394 } 1395 1396 /* Common code used when first setting up, and when resuming. */ 1397 static int talk_to_backend(struct xenbus_device *dev, 1398 struct netfront_info *info) 1399 { 1400 const char *message; 1401 struct xenbus_transaction xbt; 1402 int err; 1403 1404 /* Create shared ring, alloc event channel. */ 1405 err = setup_netfront(dev, info); 1406 if (err) 1407 goto out; 1408 1409 again: 1410 err = xenbus_transaction_start(&xbt); 1411 if (err) { 1412 xenbus_dev_fatal(dev, err, "starting transaction"); 1413 goto destroy_ring; 1414 } 1415 1416 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u", 1417 info->tx_ring_ref); 1418 if (err) { 1419 message = "writing tx ring-ref"; 1420 goto abort_transaction; 1421 } 1422 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u", 1423 info->rx_ring_ref); 1424 if (err) { 1425 message = "writing rx ring-ref"; 1426 goto abort_transaction; 1427 } 1428 err = xenbus_printf(xbt, dev->nodename, 1429 "event-channel", "%u", info->evtchn); 1430 if (err) { 1431 message = "writing event-channel"; 1432 goto abort_transaction; 1433 } 1434 1435 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1436 1); 1437 if (err) { 1438 message = "writing request-rx-copy"; 1439 goto abort_transaction; 1440 } 1441 1442 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1443 if (err) { 1444 message = "writing feature-rx-notify"; 1445 goto abort_transaction; 1446 } 1447 1448 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1449 if (err) { 1450 message = "writing feature-sg"; 1451 goto abort_transaction; 1452 } 1453 1454 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1455 if (err) { 1456 message = "writing feature-gso-tcpv4"; 1457 goto abort_transaction; 1458 } 1459 1460 err = xenbus_transaction_end(xbt, 0); 1461 if (err) { 1462 if (err == -EAGAIN) 1463 goto again; 1464 xenbus_dev_fatal(dev, err, "completing transaction"); 1465 goto destroy_ring; 1466 } 1467 1468 return 0; 1469 1470 abort_transaction: 1471 xenbus_transaction_end(xbt, 1); 1472 xenbus_dev_fatal(dev, err, "%s", message); 1473 destroy_ring: 1474 xennet_disconnect_backend(info); 1475 out: 1476 return err; 1477 } 1478 1479 static int xennet_set_sg(struct net_device *dev, u32 data) 1480 { 1481 if (data) { 1482 struct netfront_info *np = netdev_priv(dev); 1483 int val; 1484 1485 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1486 "%d", &val) < 0) 1487 val = 0; 1488 if (!val) 1489 return -ENOSYS; 1490 } else if (dev->mtu > ETH_DATA_LEN) 1491 dev->mtu = ETH_DATA_LEN; 1492 1493 return ethtool_op_set_sg(dev, data); 1494 } 1495 1496 static int xennet_set_tso(struct net_device *dev, u32 data) 1497 { 1498 if (data) { 1499 struct netfront_info *np = netdev_priv(dev); 1500 int val; 1501 1502 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1503 "feature-gso-tcpv4", "%d", &val) < 0) 1504 val = 0; 1505 if (!val) 1506 return -ENOSYS; 1507 } 1508 1509 return ethtool_op_set_tso(dev, data); 1510 } 1511 1512 static void xennet_set_features(struct net_device *dev) 1513 { 1514 /* Turn off all GSO bits except ROBUST. */ 1515 dev->features &= ~NETIF_F_GSO_MASK; 1516 dev->features |= NETIF_F_GSO_ROBUST; 1517 xennet_set_sg(dev, 0); 1518 1519 /* We need checksum offload to enable scatter/gather and TSO. */ 1520 if (!(dev->features & NETIF_F_IP_CSUM)) 1521 return; 1522 1523 if (!xennet_set_sg(dev, 1)) 1524 xennet_set_tso(dev, 1); 1525 } 1526 1527 static int xennet_connect(struct net_device *dev) 1528 { 1529 struct netfront_info *np = netdev_priv(dev); 1530 int i, requeue_idx, err; 1531 struct sk_buff *skb; 1532 grant_ref_t ref; 1533 struct xen_netif_rx_request *req; 1534 unsigned int feature_rx_copy; 1535 1536 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1537 "feature-rx-copy", "%u", &feature_rx_copy); 1538 if (err != 1) 1539 feature_rx_copy = 0; 1540 1541 if (!feature_rx_copy) { 1542 dev_info(&dev->dev, 1543 "backend does not support copying receive path\n"); 1544 return -ENODEV; 1545 } 1546 1547 err = talk_to_backend(np->xbdev, np); 1548 if (err) 1549 return err; 1550 1551 xennet_set_features(dev); 1552 1553 spin_lock_bh(&np->rx_lock); 1554 spin_lock_irq(&np->tx_lock); 1555 1556 /* Step 1: Discard all pending TX packet fragments. */ 1557 xennet_release_tx_bufs(np); 1558 1559 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ 1560 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { 1561 if (!np->rx_skbs[i]) 1562 continue; 1563 1564 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i); 1565 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i); 1566 req = RING_GET_REQUEST(&np->rx, requeue_idx); 1567 1568 gnttab_grant_foreign_access_ref( 1569 ref, np->xbdev->otherend_id, 1570 pfn_to_mfn(page_to_pfn(skb_shinfo(skb)-> 1571 frags->page)), 1572 0); 1573 req->gref = ref; 1574 req->id = requeue_idx; 1575 1576 requeue_idx++; 1577 } 1578 1579 np->rx.req_prod_pvt = requeue_idx; 1580 1581 /* 1582 * Step 3: All public and private state should now be sane. Get 1583 * ready to start sending and receiving packets and give the driver 1584 * domain a kick because we've probably just requeued some 1585 * packets. 1586 */ 1587 netif_carrier_on(np->netdev); 1588 notify_remote_via_irq(np->netdev->irq); 1589 xennet_tx_buf_gc(dev); 1590 xennet_alloc_rx_buffers(dev); 1591 1592 spin_unlock_irq(&np->tx_lock); 1593 spin_unlock_bh(&np->rx_lock); 1594 1595 return 0; 1596 } 1597 1598 /** 1599 * Callback received when the backend's state changes. 1600 */ 1601 static void backend_changed(struct xenbus_device *dev, 1602 enum xenbus_state backend_state) 1603 { 1604 struct netfront_info *np = dev_get_drvdata(&dev->dev); 1605 struct net_device *netdev = np->netdev; 1606 1607 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 1608 1609 switch (backend_state) { 1610 case XenbusStateInitialising: 1611 case XenbusStateInitialised: 1612 case XenbusStateConnected: 1613 case XenbusStateUnknown: 1614 case XenbusStateClosed: 1615 break; 1616 1617 case XenbusStateInitWait: 1618 if (dev->state != XenbusStateInitialising) 1619 break; 1620 if (xennet_connect(netdev) != 0) 1621 break; 1622 xenbus_switch_state(dev, XenbusStateConnected); 1623 break; 1624 1625 case XenbusStateClosing: 1626 xenbus_frontend_closed(dev); 1627 break; 1628 } 1629 } 1630 1631 static const struct ethtool_ops xennet_ethtool_ops = 1632 { 1633 .set_tx_csum = ethtool_op_set_tx_csum, 1634 .set_sg = xennet_set_sg, 1635 .set_tso = xennet_set_tso, 1636 .get_link = ethtool_op_get_link, 1637 }; 1638 1639 #ifdef CONFIG_SYSFS 1640 static ssize_t show_rxbuf_min(struct device *dev, 1641 struct device_attribute *attr, char *buf) 1642 { 1643 struct net_device *netdev = to_net_dev(dev); 1644 struct netfront_info *info = netdev_priv(netdev); 1645 1646 return sprintf(buf, "%u\n", info->rx_min_target); 1647 } 1648 1649 static ssize_t store_rxbuf_min(struct device *dev, 1650 struct device_attribute *attr, 1651 const char *buf, size_t len) 1652 { 1653 struct net_device *netdev = to_net_dev(dev); 1654 struct netfront_info *np = netdev_priv(netdev); 1655 char *endp; 1656 unsigned long target; 1657 1658 if (!capable(CAP_NET_ADMIN)) 1659 return -EPERM; 1660 1661 target = simple_strtoul(buf, &endp, 0); 1662 if (endp == buf) 1663 return -EBADMSG; 1664 1665 if (target < RX_MIN_TARGET) 1666 target = RX_MIN_TARGET; 1667 if (target > RX_MAX_TARGET) 1668 target = RX_MAX_TARGET; 1669 1670 spin_lock_bh(&np->rx_lock); 1671 if (target > np->rx_max_target) 1672 np->rx_max_target = target; 1673 np->rx_min_target = target; 1674 if (target > np->rx_target) 1675 np->rx_target = target; 1676 1677 xennet_alloc_rx_buffers(netdev); 1678 1679 spin_unlock_bh(&np->rx_lock); 1680 return len; 1681 } 1682 1683 static ssize_t show_rxbuf_max(struct device *dev, 1684 struct device_attribute *attr, char *buf) 1685 { 1686 struct net_device *netdev = to_net_dev(dev); 1687 struct netfront_info *info = netdev_priv(netdev); 1688 1689 return sprintf(buf, "%u\n", info->rx_max_target); 1690 } 1691 1692 static ssize_t store_rxbuf_max(struct device *dev, 1693 struct device_attribute *attr, 1694 const char *buf, size_t len) 1695 { 1696 struct net_device *netdev = to_net_dev(dev); 1697 struct netfront_info *np = netdev_priv(netdev); 1698 char *endp; 1699 unsigned long target; 1700 1701 if (!capable(CAP_NET_ADMIN)) 1702 return -EPERM; 1703 1704 target = simple_strtoul(buf, &endp, 0); 1705 if (endp == buf) 1706 return -EBADMSG; 1707 1708 if (target < RX_MIN_TARGET) 1709 target = RX_MIN_TARGET; 1710 if (target > RX_MAX_TARGET) 1711 target = RX_MAX_TARGET; 1712 1713 spin_lock_bh(&np->rx_lock); 1714 if (target < np->rx_min_target) 1715 np->rx_min_target = target; 1716 np->rx_max_target = target; 1717 if (target < np->rx_target) 1718 np->rx_target = target; 1719 1720 xennet_alloc_rx_buffers(netdev); 1721 1722 spin_unlock_bh(&np->rx_lock); 1723 return len; 1724 } 1725 1726 static ssize_t show_rxbuf_cur(struct device *dev, 1727 struct device_attribute *attr, char *buf) 1728 { 1729 struct net_device *netdev = to_net_dev(dev); 1730 struct netfront_info *info = netdev_priv(netdev); 1731 1732 return sprintf(buf, "%u\n", info->rx_target); 1733 } 1734 1735 static struct device_attribute xennet_attrs[] = { 1736 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), 1737 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), 1738 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), 1739 }; 1740 1741 static int xennet_sysfs_addif(struct net_device *netdev) 1742 { 1743 int i; 1744 int err; 1745 1746 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { 1747 err = device_create_file(&netdev->dev, 1748 &xennet_attrs[i]); 1749 if (err) 1750 goto fail; 1751 } 1752 return 0; 1753 1754 fail: 1755 while (--i >= 0) 1756 device_remove_file(&netdev->dev, &xennet_attrs[i]); 1757 return err; 1758 } 1759 1760 static void xennet_sysfs_delif(struct net_device *netdev) 1761 { 1762 int i; 1763 1764 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) 1765 device_remove_file(&netdev->dev, &xennet_attrs[i]); 1766 } 1767 1768 #endif /* CONFIG_SYSFS */ 1769 1770 static struct xenbus_device_id netfront_ids[] = { 1771 { "vif" }, 1772 { "" } 1773 }; 1774 1775 1776 static int __devexit xennet_remove(struct xenbus_device *dev) 1777 { 1778 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1779 1780 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1781 1782 unregister_netdev(info->netdev); 1783 1784 xennet_disconnect_backend(info); 1785 1786 del_timer_sync(&info->rx_refill_timer); 1787 1788 xennet_sysfs_delif(info->netdev); 1789 1790 free_netdev(info->netdev); 1791 1792 return 0; 1793 } 1794 1795 static struct xenbus_driver netfront_driver = { 1796 .name = "vif", 1797 .owner = THIS_MODULE, 1798 .ids = netfront_ids, 1799 .probe = netfront_probe, 1800 .remove = __devexit_p(xennet_remove), 1801 .resume = netfront_resume, 1802 .otherend_changed = backend_changed, 1803 }; 1804 1805 static int __init netif_init(void) 1806 { 1807 if (!xen_domain()) 1808 return -ENODEV; 1809 1810 if (xen_initial_domain()) 1811 return 0; 1812 1813 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n"); 1814 1815 return xenbus_register_frontend(&netfront_driver); 1816 } 1817 module_init(netif_init); 1818 1819 1820 static void __exit netif_exit(void) 1821 { 1822 if (xen_initial_domain()) 1823 return; 1824 1825 xenbus_unregister_driver(&netfront_driver); 1826 } 1827 module_exit(netif_exit); 1828 1829 MODULE_DESCRIPTION("Xen virtual network device frontend"); 1830 MODULE_LICENSE("GPL"); 1831 MODULE_ALIAS("xen:vif"); 1832 MODULE_ALIAS("xennet"); 1833