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 <linux/slab.h> 44 #include <net/ip.h> 45 46 #include <asm/xen/page.h> 47 #include <xen/xen.h> 48 #include <xen/xenbus.h> 49 #include <xen/events.h> 50 #include <xen/page.h> 51 #include <xen/platform_pci.h> 52 #include <xen/grant_table.h> 53 54 #include <xen/interface/io/netif.h> 55 #include <xen/interface/memory.h> 56 #include <xen/interface/grant_table.h> 57 58 static const struct ethtool_ops xennet_ethtool_ops; 59 60 struct netfront_cb { 61 int pull_to; 62 }; 63 64 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 65 66 #define RX_COPY_THRESHOLD 256 67 68 #define GRANT_INVALID_REF 0 69 70 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) 71 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) 72 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256) 73 74 struct netfront_stats { 75 u64 rx_packets; 76 u64 tx_packets; 77 u64 rx_bytes; 78 u64 tx_bytes; 79 struct u64_stats_sync syncp; 80 }; 81 82 struct netfront_info { 83 struct list_head list; 84 struct net_device *netdev; 85 86 struct napi_struct napi; 87 88 unsigned int evtchn; 89 struct xenbus_device *xbdev; 90 91 spinlock_t tx_lock; 92 struct xen_netif_tx_front_ring tx; 93 int tx_ring_ref; 94 95 /* 96 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 97 * are linked from tx_skb_freelist through skb_entry.link. 98 * 99 * NB. Freelist index entries are always going to be less than 100 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 101 * greater than PAGE_OFFSET: we use this property to distinguish 102 * them. 103 */ 104 union skb_entry { 105 struct sk_buff *skb; 106 unsigned long link; 107 } tx_skbs[NET_TX_RING_SIZE]; 108 grant_ref_t gref_tx_head; 109 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 110 unsigned tx_skb_freelist; 111 112 spinlock_t rx_lock ____cacheline_aligned_in_smp; 113 struct xen_netif_rx_front_ring rx; 114 int rx_ring_ref; 115 116 /* Receive-ring batched refills. */ 117 #define RX_MIN_TARGET 8 118 #define RX_DFL_MIN_TARGET 64 119 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) 120 unsigned rx_min_target, rx_max_target, rx_target; 121 struct sk_buff_head rx_batch; 122 123 struct timer_list rx_refill_timer; 124 125 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 126 grant_ref_t gref_rx_head; 127 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 128 129 unsigned long rx_pfn_array[NET_RX_RING_SIZE]; 130 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; 131 struct mmu_update rx_mmu[NET_RX_RING_SIZE]; 132 133 /* Statistics */ 134 struct netfront_stats __percpu *stats; 135 136 unsigned long rx_gso_checksum_fixup; 137 }; 138 139 struct netfront_rx_info { 140 struct xen_netif_rx_response rx; 141 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 142 }; 143 144 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 145 { 146 list->link = id; 147 } 148 149 static int skb_entry_is_link(const union skb_entry *list) 150 { 151 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 152 return (unsigned long)list->skb < PAGE_OFFSET; 153 } 154 155 /* 156 * Access macros for acquiring freeing slots in tx_skbs[]. 157 */ 158 159 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 160 unsigned short id) 161 { 162 skb_entry_set_link(&list[id], *head); 163 *head = id; 164 } 165 166 static unsigned short get_id_from_freelist(unsigned *head, 167 union skb_entry *list) 168 { 169 unsigned int id = *head; 170 *head = list[id].link; 171 return id; 172 } 173 174 static int xennet_rxidx(RING_IDX idx) 175 { 176 return idx & (NET_RX_RING_SIZE - 1); 177 } 178 179 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np, 180 RING_IDX ri) 181 { 182 int i = xennet_rxidx(ri); 183 struct sk_buff *skb = np->rx_skbs[i]; 184 np->rx_skbs[i] = NULL; 185 return skb; 186 } 187 188 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np, 189 RING_IDX ri) 190 { 191 int i = xennet_rxidx(ri); 192 grant_ref_t ref = np->grant_rx_ref[i]; 193 np->grant_rx_ref[i] = GRANT_INVALID_REF; 194 return ref; 195 } 196 197 #ifdef CONFIG_SYSFS 198 static int xennet_sysfs_addif(struct net_device *netdev); 199 static void xennet_sysfs_delif(struct net_device *netdev); 200 #else /* !CONFIG_SYSFS */ 201 #define xennet_sysfs_addif(dev) (0) 202 #define xennet_sysfs_delif(dev) do { } while (0) 203 #endif 204 205 static bool xennet_can_sg(struct net_device *dev) 206 { 207 return dev->features & NETIF_F_SG; 208 } 209 210 211 static void rx_refill_timeout(unsigned long data) 212 { 213 struct net_device *dev = (struct net_device *)data; 214 struct netfront_info *np = netdev_priv(dev); 215 napi_schedule(&np->napi); 216 } 217 218 static int netfront_tx_slot_available(struct netfront_info *np) 219 { 220 return (np->tx.req_prod_pvt - np->tx.rsp_cons) < 221 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2); 222 } 223 224 static void xennet_maybe_wake_tx(struct net_device *dev) 225 { 226 struct netfront_info *np = netdev_priv(dev); 227 228 if (unlikely(netif_queue_stopped(dev)) && 229 netfront_tx_slot_available(np) && 230 likely(netif_running(dev))) 231 netif_wake_queue(dev); 232 } 233 234 static void xennet_alloc_rx_buffers(struct net_device *dev) 235 { 236 unsigned short id; 237 struct netfront_info *np = netdev_priv(dev); 238 struct sk_buff *skb; 239 struct page *page; 240 int i, batch_target, notify; 241 RING_IDX req_prod = np->rx.req_prod_pvt; 242 grant_ref_t ref; 243 unsigned long pfn; 244 void *vaddr; 245 struct xen_netif_rx_request *req; 246 247 if (unlikely(!netif_carrier_ok(dev))) 248 return; 249 250 /* 251 * Allocate skbuffs greedily, even though we batch updates to the 252 * receive ring. This creates a less bursty demand on the memory 253 * allocator, so should reduce the chance of failed allocation requests 254 * both for ourself and for other kernel subsystems. 255 */ 256 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); 257 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { 258 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, 259 GFP_ATOMIC | __GFP_NOWARN); 260 if (unlikely(!skb)) 261 goto no_skb; 262 263 /* Align ip header to a 16 bytes boundary */ 264 skb_reserve(skb, NET_IP_ALIGN); 265 266 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 267 if (!page) { 268 kfree_skb(skb); 269 no_skb: 270 /* Any skbuffs queued for refill? Force them out. */ 271 if (i != 0) 272 goto refill; 273 /* Could not allocate any skbuffs. Try again later. */ 274 mod_timer(&np->rx_refill_timer, 275 jiffies + (HZ/10)); 276 break; 277 } 278 279 __skb_fill_page_desc(skb, 0, page, 0, 0); 280 skb_shinfo(skb)->nr_frags = 1; 281 __skb_queue_tail(&np->rx_batch, skb); 282 } 283 284 /* Is the batch large enough to be worthwhile? */ 285 if (i < (np->rx_target/2)) { 286 if (req_prod > np->rx.sring->req_prod) 287 goto push; 288 return; 289 } 290 291 /* Adjust our fill target if we risked running out of buffers. */ 292 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && 293 ((np->rx_target *= 2) > np->rx_max_target)) 294 np->rx_target = np->rx_max_target; 295 296 refill: 297 for (i = 0; ; i++) { 298 skb = __skb_dequeue(&np->rx_batch); 299 if (skb == NULL) 300 break; 301 302 skb->dev = dev; 303 304 id = xennet_rxidx(req_prod + i); 305 306 BUG_ON(np->rx_skbs[id]); 307 np->rx_skbs[id] = skb; 308 309 ref = gnttab_claim_grant_reference(&np->gref_rx_head); 310 BUG_ON((signed short)ref < 0); 311 np->grant_rx_ref[id] = ref; 312 313 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); 314 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0])); 315 316 req = RING_GET_REQUEST(&np->rx, req_prod + i); 317 gnttab_grant_foreign_access_ref(ref, 318 np->xbdev->otherend_id, 319 pfn_to_mfn(pfn), 320 0); 321 322 req->id = id; 323 req->gref = ref; 324 } 325 326 wmb(); /* barrier so backend seens requests */ 327 328 /* Above is a suitable barrier to ensure backend will see requests. */ 329 np->rx.req_prod_pvt = req_prod + i; 330 push: 331 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); 332 if (notify) 333 notify_remote_via_irq(np->netdev->irq); 334 } 335 336 static int xennet_open(struct net_device *dev) 337 { 338 struct netfront_info *np = netdev_priv(dev); 339 340 napi_enable(&np->napi); 341 342 spin_lock_bh(&np->rx_lock); 343 if (netif_carrier_ok(dev)) { 344 xennet_alloc_rx_buffers(dev); 345 np->rx.sring->rsp_event = np->rx.rsp_cons + 1; 346 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) 347 napi_schedule(&np->napi); 348 } 349 spin_unlock_bh(&np->rx_lock); 350 351 netif_start_queue(dev); 352 353 return 0; 354 } 355 356 static void xennet_tx_buf_gc(struct net_device *dev) 357 { 358 RING_IDX cons, prod; 359 unsigned short id; 360 struct netfront_info *np = netdev_priv(dev); 361 struct sk_buff *skb; 362 363 BUG_ON(!netif_carrier_ok(dev)); 364 365 do { 366 prod = np->tx.sring->rsp_prod; 367 rmb(); /* Ensure we see responses up to 'rp'. */ 368 369 for (cons = np->tx.rsp_cons; cons != prod; cons++) { 370 struct xen_netif_tx_response *txrsp; 371 372 txrsp = RING_GET_RESPONSE(&np->tx, cons); 373 if (txrsp->status == XEN_NETIF_RSP_NULL) 374 continue; 375 376 id = txrsp->id; 377 skb = np->tx_skbs[id].skb; 378 if (unlikely(gnttab_query_foreign_access( 379 np->grant_tx_ref[id]) != 0)) { 380 printk(KERN_ALERT "xennet_tx_buf_gc: warning " 381 "-- grant still in use by backend " 382 "domain.\n"); 383 BUG(); 384 } 385 gnttab_end_foreign_access_ref( 386 np->grant_tx_ref[id], GNTMAP_readonly); 387 gnttab_release_grant_reference( 388 &np->gref_tx_head, np->grant_tx_ref[id]); 389 np->grant_tx_ref[id] = GRANT_INVALID_REF; 390 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); 391 dev_kfree_skb_irq(skb); 392 } 393 394 np->tx.rsp_cons = prod; 395 396 /* 397 * Set a new event, then check for race with update of tx_cons. 398 * Note that it is essential to schedule a callback, no matter 399 * how few buffers are pending. Even if there is space in the 400 * transmit ring, higher layers may be blocked because too much 401 * data is outstanding: in such cases notification from Xen is 402 * likely to be the only kick that we'll get. 403 */ 404 np->tx.sring->rsp_event = 405 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1; 406 mb(); /* update shared area */ 407 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); 408 409 xennet_maybe_wake_tx(dev); 410 } 411 412 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, 413 struct xen_netif_tx_request *tx) 414 { 415 struct netfront_info *np = netdev_priv(dev); 416 char *data = skb->data; 417 unsigned long mfn; 418 RING_IDX prod = np->tx.req_prod_pvt; 419 int frags = skb_shinfo(skb)->nr_frags; 420 unsigned int offset = offset_in_page(data); 421 unsigned int len = skb_headlen(skb); 422 unsigned int id; 423 grant_ref_t ref; 424 int i; 425 426 /* While the header overlaps a page boundary (including being 427 larger than a page), split it it into page-sized chunks. */ 428 while (len > PAGE_SIZE - offset) { 429 tx->size = PAGE_SIZE - offset; 430 tx->flags |= XEN_NETTXF_more_data; 431 len -= tx->size; 432 data += tx->size; 433 offset = 0; 434 435 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 436 np->tx_skbs[id].skb = skb_get(skb); 437 tx = RING_GET_REQUEST(&np->tx, prod++); 438 tx->id = id; 439 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 440 BUG_ON((signed short)ref < 0); 441 442 mfn = virt_to_mfn(data); 443 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, 444 mfn, GNTMAP_readonly); 445 446 tx->gref = np->grant_tx_ref[id] = ref; 447 tx->offset = offset; 448 tx->size = len; 449 tx->flags = 0; 450 } 451 452 /* Grant backend access to each skb fragment page. */ 453 for (i = 0; i < frags; i++) { 454 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 455 struct page *page = skb_frag_page(frag); 456 457 len = skb_frag_size(frag); 458 offset = frag->page_offset; 459 460 /* Data must not cross a page boundary. */ 461 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); 462 463 /* Skip unused frames from start of page */ 464 page += offset >> PAGE_SHIFT; 465 offset &= ~PAGE_MASK; 466 467 while (len > 0) { 468 unsigned long bytes; 469 470 BUG_ON(offset >= PAGE_SIZE); 471 472 bytes = PAGE_SIZE - offset; 473 if (bytes > len) 474 bytes = len; 475 476 tx->flags |= XEN_NETTXF_more_data; 477 478 id = get_id_from_freelist(&np->tx_skb_freelist, 479 np->tx_skbs); 480 np->tx_skbs[id].skb = skb_get(skb); 481 tx = RING_GET_REQUEST(&np->tx, prod++); 482 tx->id = id; 483 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 484 BUG_ON((signed short)ref < 0); 485 486 mfn = pfn_to_mfn(page_to_pfn(page)); 487 gnttab_grant_foreign_access_ref(ref, 488 np->xbdev->otherend_id, 489 mfn, GNTMAP_readonly); 490 491 tx->gref = np->grant_tx_ref[id] = ref; 492 tx->offset = offset; 493 tx->size = bytes; 494 tx->flags = 0; 495 496 offset += bytes; 497 len -= bytes; 498 499 /* Next frame */ 500 if (offset == PAGE_SIZE && len) { 501 BUG_ON(!PageCompound(page)); 502 page++; 503 offset = 0; 504 } 505 } 506 } 507 508 np->tx.req_prod_pvt = prod; 509 } 510 511 /* 512 * Count how many ring slots are required to send the frags of this 513 * skb. Each frag might be a compound page. 514 */ 515 static int xennet_count_skb_frag_slots(struct sk_buff *skb) 516 { 517 int i, frags = skb_shinfo(skb)->nr_frags; 518 int pages = 0; 519 520 for (i = 0; i < frags; i++) { 521 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 522 unsigned long size = skb_frag_size(frag); 523 unsigned long offset = frag->page_offset; 524 525 /* Skip unused frames from start of page */ 526 offset &= ~PAGE_MASK; 527 528 pages += PFN_UP(offset + size); 529 } 530 531 return pages; 532 } 533 534 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 535 { 536 unsigned short id; 537 struct netfront_info *np = netdev_priv(dev); 538 struct netfront_stats *stats = this_cpu_ptr(np->stats); 539 struct xen_netif_tx_request *tx; 540 char *data = skb->data; 541 RING_IDX i; 542 grant_ref_t ref; 543 unsigned long mfn; 544 int notify; 545 int slots; 546 unsigned int offset = offset_in_page(data); 547 unsigned int len = skb_headlen(skb); 548 unsigned long flags; 549 550 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + 551 xennet_count_skb_frag_slots(skb); 552 if (unlikely(slots > MAX_SKB_FRAGS + 1)) { 553 net_alert_ratelimited( 554 "xennet: skb rides the rocket: %d slots\n", slots); 555 goto drop; 556 } 557 558 spin_lock_irqsave(&np->tx_lock, flags); 559 560 if (unlikely(!netif_carrier_ok(dev) || 561 (slots > 1 && !xennet_can_sg(dev)) || 562 netif_needs_gso(skb, netif_skb_features(skb)))) { 563 spin_unlock_irqrestore(&np->tx_lock, flags); 564 goto drop; 565 } 566 567 i = np->tx.req_prod_pvt; 568 569 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 570 np->tx_skbs[id].skb = skb; 571 572 tx = RING_GET_REQUEST(&np->tx, i); 573 574 tx->id = id; 575 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 576 BUG_ON((signed short)ref < 0); 577 mfn = virt_to_mfn(data); 578 gnttab_grant_foreign_access_ref( 579 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); 580 tx->gref = np->grant_tx_ref[id] = ref; 581 tx->offset = offset; 582 tx->size = len; 583 584 tx->flags = 0; 585 if (skb->ip_summed == CHECKSUM_PARTIAL) 586 /* local packet? */ 587 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 588 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 589 /* remote but checksummed. */ 590 tx->flags |= XEN_NETTXF_data_validated; 591 592 if (skb_shinfo(skb)->gso_size) { 593 struct xen_netif_extra_info *gso; 594 595 gso = (struct xen_netif_extra_info *) 596 RING_GET_REQUEST(&np->tx, ++i); 597 598 tx->flags |= XEN_NETTXF_extra_info; 599 600 gso->u.gso.size = skb_shinfo(skb)->gso_size; 601 gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; 602 gso->u.gso.pad = 0; 603 gso->u.gso.features = 0; 604 605 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 606 gso->flags = 0; 607 } 608 609 np->tx.req_prod_pvt = i + 1; 610 611 xennet_make_frags(skb, dev, tx); 612 tx->size = skb->len; 613 614 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); 615 if (notify) 616 notify_remote_via_irq(np->netdev->irq); 617 618 u64_stats_update_begin(&stats->syncp); 619 stats->tx_bytes += skb->len; 620 stats->tx_packets++; 621 u64_stats_update_end(&stats->syncp); 622 623 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 624 xennet_tx_buf_gc(dev); 625 626 if (!netfront_tx_slot_available(np)) 627 netif_stop_queue(dev); 628 629 spin_unlock_irqrestore(&np->tx_lock, flags); 630 631 return NETDEV_TX_OK; 632 633 drop: 634 dev->stats.tx_dropped++; 635 dev_kfree_skb(skb); 636 return NETDEV_TX_OK; 637 } 638 639 static int xennet_close(struct net_device *dev) 640 { 641 struct netfront_info *np = netdev_priv(dev); 642 netif_stop_queue(np->netdev); 643 napi_disable(&np->napi); 644 return 0; 645 } 646 647 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb, 648 grant_ref_t ref) 649 { 650 int new = xennet_rxidx(np->rx.req_prod_pvt); 651 652 BUG_ON(np->rx_skbs[new]); 653 np->rx_skbs[new] = skb; 654 np->grant_rx_ref[new] = ref; 655 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new; 656 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref; 657 np->rx.req_prod_pvt++; 658 } 659 660 static int xennet_get_extras(struct netfront_info *np, 661 struct xen_netif_extra_info *extras, 662 RING_IDX rp) 663 664 { 665 struct xen_netif_extra_info *extra; 666 struct device *dev = &np->netdev->dev; 667 RING_IDX cons = np->rx.rsp_cons; 668 int err = 0; 669 670 do { 671 struct sk_buff *skb; 672 grant_ref_t ref; 673 674 if (unlikely(cons + 1 == rp)) { 675 if (net_ratelimit()) 676 dev_warn(dev, "Missing extra info\n"); 677 err = -EBADR; 678 break; 679 } 680 681 extra = (struct xen_netif_extra_info *) 682 RING_GET_RESPONSE(&np->rx, ++cons); 683 684 if (unlikely(!extra->type || 685 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 686 if (net_ratelimit()) 687 dev_warn(dev, "Invalid extra type: %d\n", 688 extra->type); 689 err = -EINVAL; 690 } else { 691 memcpy(&extras[extra->type - 1], extra, 692 sizeof(*extra)); 693 } 694 695 skb = xennet_get_rx_skb(np, cons); 696 ref = xennet_get_rx_ref(np, cons); 697 xennet_move_rx_slot(np, skb, ref); 698 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 699 700 np->rx.rsp_cons = cons; 701 return err; 702 } 703 704 static int xennet_get_responses(struct netfront_info *np, 705 struct netfront_rx_info *rinfo, RING_IDX rp, 706 struct sk_buff_head *list) 707 { 708 struct xen_netif_rx_response *rx = &rinfo->rx; 709 struct xen_netif_extra_info *extras = rinfo->extras; 710 struct device *dev = &np->netdev->dev; 711 RING_IDX cons = np->rx.rsp_cons; 712 struct sk_buff *skb = xennet_get_rx_skb(np, cons); 713 grant_ref_t ref = xennet_get_rx_ref(np, cons); 714 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 715 int slots = 1; 716 int err = 0; 717 unsigned long ret; 718 719 if (rx->flags & XEN_NETRXF_extra_info) { 720 err = xennet_get_extras(np, extras, rp); 721 cons = np->rx.rsp_cons; 722 } 723 724 for (;;) { 725 if (unlikely(rx->status < 0 || 726 rx->offset + rx->status > PAGE_SIZE)) { 727 if (net_ratelimit()) 728 dev_warn(dev, "rx->offset: %x, size: %u\n", 729 rx->offset, rx->status); 730 xennet_move_rx_slot(np, skb, ref); 731 err = -EINVAL; 732 goto next; 733 } 734 735 /* 736 * This definitely indicates a bug, either in this driver or in 737 * the backend driver. In future this should flag the bad 738 * situation to the system controller to reboot the backed. 739 */ 740 if (ref == GRANT_INVALID_REF) { 741 if (net_ratelimit()) 742 dev_warn(dev, "Bad rx response id %d.\n", 743 rx->id); 744 err = -EINVAL; 745 goto next; 746 } 747 748 ret = gnttab_end_foreign_access_ref(ref, 0); 749 BUG_ON(!ret); 750 751 gnttab_release_grant_reference(&np->gref_rx_head, ref); 752 753 __skb_queue_tail(list, skb); 754 755 next: 756 if (!(rx->flags & XEN_NETRXF_more_data)) 757 break; 758 759 if (cons + slots == rp) { 760 if (net_ratelimit()) 761 dev_warn(dev, "Need more slots\n"); 762 err = -ENOENT; 763 break; 764 } 765 766 rx = RING_GET_RESPONSE(&np->rx, cons + slots); 767 skb = xennet_get_rx_skb(np, cons + slots); 768 ref = xennet_get_rx_ref(np, cons + slots); 769 slots++; 770 } 771 772 if (unlikely(slots > max)) { 773 if (net_ratelimit()) 774 dev_warn(dev, "Too many frags\n"); 775 err = -E2BIG; 776 } 777 778 if (unlikely(err)) 779 np->rx.rsp_cons = cons + slots; 780 781 return err; 782 } 783 784 static int xennet_set_skb_gso(struct sk_buff *skb, 785 struct xen_netif_extra_info *gso) 786 { 787 if (!gso->u.gso.size) { 788 if (net_ratelimit()) 789 printk(KERN_WARNING "GSO size must not be zero.\n"); 790 return -EINVAL; 791 } 792 793 /* Currently only TCPv4 S.O. is supported. */ 794 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) { 795 if (net_ratelimit()) 796 printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type); 797 return -EINVAL; 798 } 799 800 skb_shinfo(skb)->gso_size = gso->u.gso.size; 801 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 802 803 /* Header must be checked, and gso_segs computed. */ 804 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 805 skb_shinfo(skb)->gso_segs = 0; 806 807 return 0; 808 } 809 810 static RING_IDX xennet_fill_frags(struct netfront_info *np, 811 struct sk_buff *skb, 812 struct sk_buff_head *list) 813 { 814 struct skb_shared_info *shinfo = skb_shinfo(skb); 815 int nr_frags = shinfo->nr_frags; 816 RING_IDX cons = np->rx.rsp_cons; 817 struct sk_buff *nskb; 818 819 while ((nskb = __skb_dequeue(list))) { 820 struct xen_netif_rx_response *rx = 821 RING_GET_RESPONSE(&np->rx, ++cons); 822 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 823 824 __skb_fill_page_desc(skb, nr_frags, 825 skb_frag_page(nfrag), 826 rx->offset, rx->status); 827 828 skb->data_len += rx->status; 829 830 skb_shinfo(nskb)->nr_frags = 0; 831 kfree_skb(nskb); 832 833 nr_frags++; 834 } 835 836 shinfo->nr_frags = nr_frags; 837 return cons; 838 } 839 840 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 841 { 842 struct iphdr *iph; 843 unsigned char *th; 844 int err = -EPROTO; 845 int recalculate_partial_csum = 0; 846 847 /* 848 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 849 * peers can fail to set NETRXF_csum_blank when sending a GSO 850 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 851 * recalculate the partial checksum. 852 */ 853 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 854 struct netfront_info *np = netdev_priv(dev); 855 np->rx_gso_checksum_fixup++; 856 skb->ip_summed = CHECKSUM_PARTIAL; 857 recalculate_partial_csum = 1; 858 } 859 860 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 861 if (skb->ip_summed != CHECKSUM_PARTIAL) 862 return 0; 863 864 if (skb->protocol != htons(ETH_P_IP)) 865 goto out; 866 867 iph = (void *)skb->data; 868 th = skb->data + 4 * iph->ihl; 869 if (th >= skb_tail_pointer(skb)) 870 goto out; 871 872 skb->csum_start = th - skb->head; 873 switch (iph->protocol) { 874 case IPPROTO_TCP: 875 skb->csum_offset = offsetof(struct tcphdr, check); 876 877 if (recalculate_partial_csum) { 878 struct tcphdr *tcph = (struct tcphdr *)th; 879 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, 880 skb->len - iph->ihl*4, 881 IPPROTO_TCP, 0); 882 } 883 break; 884 case IPPROTO_UDP: 885 skb->csum_offset = offsetof(struct udphdr, check); 886 887 if (recalculate_partial_csum) { 888 struct udphdr *udph = (struct udphdr *)th; 889 udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, 890 skb->len - iph->ihl*4, 891 IPPROTO_UDP, 0); 892 } 893 break; 894 default: 895 if (net_ratelimit()) 896 printk(KERN_ERR "Attempting to checksum a non-" 897 "TCP/UDP packet, dropping a protocol" 898 " %d packet", iph->protocol); 899 goto out; 900 } 901 902 if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb)) 903 goto out; 904 905 err = 0; 906 907 out: 908 return err; 909 } 910 911 static int handle_incoming_queue(struct net_device *dev, 912 struct sk_buff_head *rxq) 913 { 914 struct netfront_info *np = netdev_priv(dev); 915 struct netfront_stats *stats = this_cpu_ptr(np->stats); 916 int packets_dropped = 0; 917 struct sk_buff *skb; 918 919 while ((skb = __skb_dequeue(rxq)) != NULL) { 920 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 921 922 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 923 924 /* Ethernet work: Delayed to here as it peeks the header. */ 925 skb->protocol = eth_type_trans(skb, dev); 926 927 if (checksum_setup(dev, skb)) { 928 kfree_skb(skb); 929 packets_dropped++; 930 dev->stats.rx_errors++; 931 continue; 932 } 933 934 u64_stats_update_begin(&stats->syncp); 935 stats->rx_packets++; 936 stats->rx_bytes += skb->len; 937 u64_stats_update_end(&stats->syncp); 938 939 /* Pass it up. */ 940 netif_receive_skb(skb); 941 } 942 943 return packets_dropped; 944 } 945 946 static int xennet_poll(struct napi_struct *napi, int budget) 947 { 948 struct netfront_info *np = container_of(napi, struct netfront_info, napi); 949 struct net_device *dev = np->netdev; 950 struct sk_buff *skb; 951 struct netfront_rx_info rinfo; 952 struct xen_netif_rx_response *rx = &rinfo.rx; 953 struct xen_netif_extra_info *extras = rinfo.extras; 954 RING_IDX i, rp; 955 int work_done; 956 struct sk_buff_head rxq; 957 struct sk_buff_head errq; 958 struct sk_buff_head tmpq; 959 unsigned long flags; 960 int err; 961 962 spin_lock(&np->rx_lock); 963 964 skb_queue_head_init(&rxq); 965 skb_queue_head_init(&errq); 966 skb_queue_head_init(&tmpq); 967 968 rp = np->rx.sring->rsp_prod; 969 rmb(); /* Ensure we see queued responses up to 'rp'. */ 970 971 i = np->rx.rsp_cons; 972 work_done = 0; 973 while ((i != rp) && (work_done < budget)) { 974 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx)); 975 memset(extras, 0, sizeof(rinfo.extras)); 976 977 err = xennet_get_responses(np, &rinfo, rp, &tmpq); 978 979 if (unlikely(err)) { 980 err: 981 while ((skb = __skb_dequeue(&tmpq))) 982 __skb_queue_tail(&errq, skb); 983 dev->stats.rx_errors++; 984 i = np->rx.rsp_cons; 985 continue; 986 } 987 988 skb = __skb_dequeue(&tmpq); 989 990 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 991 struct xen_netif_extra_info *gso; 992 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 993 994 if (unlikely(xennet_set_skb_gso(skb, gso))) { 995 __skb_queue_head(&tmpq, skb); 996 np->rx.rsp_cons += skb_queue_len(&tmpq); 997 goto err; 998 } 999 } 1000 1001 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1002 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1003 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1004 1005 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1006 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1007 skb->data_len = rx->status; 1008 1009 i = xennet_fill_frags(np, skb, &tmpq); 1010 1011 /* 1012 * Truesize is the actual allocation size, even if the 1013 * allocation is only partially used. 1014 */ 1015 skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags; 1016 skb->len += skb->data_len; 1017 1018 if (rx->flags & XEN_NETRXF_csum_blank) 1019 skb->ip_summed = CHECKSUM_PARTIAL; 1020 else if (rx->flags & XEN_NETRXF_data_validated) 1021 skb->ip_summed = CHECKSUM_UNNECESSARY; 1022 1023 __skb_queue_tail(&rxq, skb); 1024 1025 np->rx.rsp_cons = ++i; 1026 work_done++; 1027 } 1028 1029 __skb_queue_purge(&errq); 1030 1031 work_done -= handle_incoming_queue(dev, &rxq); 1032 1033 /* If we get a callback with very few responses, reduce fill target. */ 1034 /* NB. Note exponential increase, linear decrease. */ 1035 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > 1036 ((3*np->rx_target) / 4)) && 1037 (--np->rx_target < np->rx_min_target)) 1038 np->rx_target = np->rx_min_target; 1039 1040 xennet_alloc_rx_buffers(dev); 1041 1042 if (work_done < budget) { 1043 int more_to_do = 0; 1044 1045 local_irq_save(flags); 1046 1047 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); 1048 if (!more_to_do) 1049 __napi_complete(napi); 1050 1051 local_irq_restore(flags); 1052 } 1053 1054 spin_unlock(&np->rx_lock); 1055 1056 return work_done; 1057 } 1058 1059 static int xennet_change_mtu(struct net_device *dev, int mtu) 1060 { 1061 int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN; 1062 1063 if (mtu > max) 1064 return -EINVAL; 1065 dev->mtu = mtu; 1066 return 0; 1067 } 1068 1069 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, 1070 struct rtnl_link_stats64 *tot) 1071 { 1072 struct netfront_info *np = netdev_priv(dev); 1073 int cpu; 1074 1075 for_each_possible_cpu(cpu) { 1076 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu); 1077 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1078 unsigned int start; 1079 1080 do { 1081 start = u64_stats_fetch_begin_bh(&stats->syncp); 1082 1083 rx_packets = stats->rx_packets; 1084 tx_packets = stats->tx_packets; 1085 rx_bytes = stats->rx_bytes; 1086 tx_bytes = stats->tx_bytes; 1087 } while (u64_stats_fetch_retry_bh(&stats->syncp, start)); 1088 1089 tot->rx_packets += rx_packets; 1090 tot->tx_packets += tx_packets; 1091 tot->rx_bytes += rx_bytes; 1092 tot->tx_bytes += tx_bytes; 1093 } 1094 1095 tot->rx_errors = dev->stats.rx_errors; 1096 tot->tx_dropped = dev->stats.tx_dropped; 1097 1098 return tot; 1099 } 1100 1101 static void xennet_release_tx_bufs(struct netfront_info *np) 1102 { 1103 struct sk_buff *skb; 1104 int i; 1105 1106 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1107 /* Skip over entries which are actually freelist references */ 1108 if (skb_entry_is_link(&np->tx_skbs[i])) 1109 continue; 1110 1111 skb = np->tx_skbs[i].skb; 1112 gnttab_end_foreign_access_ref(np->grant_tx_ref[i], 1113 GNTMAP_readonly); 1114 gnttab_release_grant_reference(&np->gref_tx_head, 1115 np->grant_tx_ref[i]); 1116 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1117 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); 1118 dev_kfree_skb_irq(skb); 1119 } 1120 } 1121 1122 static void xennet_release_rx_bufs(struct netfront_info *np) 1123 { 1124 struct mmu_update *mmu = np->rx_mmu; 1125 struct multicall_entry *mcl = np->rx_mcl; 1126 struct sk_buff_head free_list; 1127 struct sk_buff *skb; 1128 unsigned long mfn; 1129 int xfer = 0, noxfer = 0, unused = 0; 1130 int id, ref; 1131 1132 dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n", 1133 __func__); 1134 return; 1135 1136 skb_queue_head_init(&free_list); 1137 1138 spin_lock_bh(&np->rx_lock); 1139 1140 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1141 ref = np->grant_rx_ref[id]; 1142 if (ref == GRANT_INVALID_REF) { 1143 unused++; 1144 continue; 1145 } 1146 1147 skb = np->rx_skbs[id]; 1148 mfn = gnttab_end_foreign_transfer_ref(ref); 1149 gnttab_release_grant_reference(&np->gref_rx_head, ref); 1150 np->grant_rx_ref[id] = GRANT_INVALID_REF; 1151 1152 if (0 == mfn) { 1153 skb_shinfo(skb)->nr_frags = 0; 1154 dev_kfree_skb(skb); 1155 noxfer++; 1156 continue; 1157 } 1158 1159 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 1160 /* Remap the page. */ 1161 const struct page *page = 1162 skb_frag_page(&skb_shinfo(skb)->frags[0]); 1163 unsigned long pfn = page_to_pfn(page); 1164 void *vaddr = page_address(page); 1165 1166 MULTI_update_va_mapping(mcl, (unsigned long)vaddr, 1167 mfn_pte(mfn, PAGE_KERNEL), 1168 0); 1169 mcl++; 1170 mmu->ptr = ((u64)mfn << PAGE_SHIFT) 1171 | MMU_MACHPHYS_UPDATE; 1172 mmu->val = pfn; 1173 mmu++; 1174 1175 set_phys_to_machine(pfn, mfn); 1176 } 1177 __skb_queue_tail(&free_list, skb); 1178 xfer++; 1179 } 1180 1181 dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n", 1182 __func__, xfer, noxfer, unused); 1183 1184 if (xfer) { 1185 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 1186 /* Do all the remapping work and M2P updates. */ 1187 MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu, 1188 NULL, DOMID_SELF); 1189 mcl++; 1190 HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl); 1191 } 1192 } 1193 1194 __skb_queue_purge(&free_list); 1195 1196 spin_unlock_bh(&np->rx_lock); 1197 } 1198 1199 static void xennet_uninit(struct net_device *dev) 1200 { 1201 struct netfront_info *np = netdev_priv(dev); 1202 xennet_release_tx_bufs(np); 1203 xennet_release_rx_bufs(np); 1204 gnttab_free_grant_references(np->gref_tx_head); 1205 gnttab_free_grant_references(np->gref_rx_head); 1206 } 1207 1208 static netdev_features_t xennet_fix_features(struct net_device *dev, 1209 netdev_features_t features) 1210 { 1211 struct netfront_info *np = netdev_priv(dev); 1212 int val; 1213 1214 if (features & NETIF_F_SG) { 1215 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1216 "%d", &val) < 0) 1217 val = 0; 1218 1219 if (!val) 1220 features &= ~NETIF_F_SG; 1221 } 1222 1223 if (features & NETIF_F_TSO) { 1224 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1225 "feature-gso-tcpv4", "%d", &val) < 0) 1226 val = 0; 1227 1228 if (!val) 1229 features &= ~NETIF_F_TSO; 1230 } 1231 1232 return features; 1233 } 1234 1235 static int xennet_set_features(struct net_device *dev, 1236 netdev_features_t features) 1237 { 1238 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1239 netdev_info(dev, "Reducing MTU because no SG offload"); 1240 dev->mtu = ETH_DATA_LEN; 1241 } 1242 1243 return 0; 1244 } 1245 1246 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1247 { 1248 struct net_device *dev = dev_id; 1249 struct netfront_info *np = netdev_priv(dev); 1250 unsigned long flags; 1251 1252 spin_lock_irqsave(&np->tx_lock, flags); 1253 1254 if (likely(netif_carrier_ok(dev))) { 1255 xennet_tx_buf_gc(dev); 1256 /* Under tx_lock: protects access to rx shared-ring indexes. */ 1257 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) 1258 napi_schedule(&np->napi); 1259 } 1260 1261 spin_unlock_irqrestore(&np->tx_lock, flags); 1262 1263 return IRQ_HANDLED; 1264 } 1265 1266 #ifdef CONFIG_NET_POLL_CONTROLLER 1267 static void xennet_poll_controller(struct net_device *dev) 1268 { 1269 xennet_interrupt(0, dev); 1270 } 1271 #endif 1272 1273 static const struct net_device_ops xennet_netdev_ops = { 1274 .ndo_open = xennet_open, 1275 .ndo_uninit = xennet_uninit, 1276 .ndo_stop = xennet_close, 1277 .ndo_start_xmit = xennet_start_xmit, 1278 .ndo_change_mtu = xennet_change_mtu, 1279 .ndo_get_stats64 = xennet_get_stats64, 1280 .ndo_set_mac_address = eth_mac_addr, 1281 .ndo_validate_addr = eth_validate_addr, 1282 .ndo_fix_features = xennet_fix_features, 1283 .ndo_set_features = xennet_set_features, 1284 #ifdef CONFIG_NET_POLL_CONTROLLER 1285 .ndo_poll_controller = xennet_poll_controller, 1286 #endif 1287 }; 1288 1289 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1290 { 1291 int i, err; 1292 struct net_device *netdev; 1293 struct netfront_info *np; 1294 1295 netdev = alloc_etherdev(sizeof(struct netfront_info)); 1296 if (!netdev) 1297 return ERR_PTR(-ENOMEM); 1298 1299 np = netdev_priv(netdev); 1300 np->xbdev = dev; 1301 1302 spin_lock_init(&np->tx_lock); 1303 spin_lock_init(&np->rx_lock); 1304 1305 skb_queue_head_init(&np->rx_batch); 1306 np->rx_target = RX_DFL_MIN_TARGET; 1307 np->rx_min_target = RX_DFL_MIN_TARGET; 1308 np->rx_max_target = RX_MAX_TARGET; 1309 1310 init_timer(&np->rx_refill_timer); 1311 np->rx_refill_timer.data = (unsigned long)netdev; 1312 np->rx_refill_timer.function = rx_refill_timeout; 1313 1314 err = -ENOMEM; 1315 np->stats = alloc_percpu(struct netfront_stats); 1316 if (np->stats == NULL) 1317 goto exit; 1318 1319 /* Initialise tx_skbs as a free chain containing every entry. */ 1320 np->tx_skb_freelist = 0; 1321 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1322 skb_entry_set_link(&np->tx_skbs[i], i+1); 1323 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1324 } 1325 1326 /* Clear out rx_skbs */ 1327 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1328 np->rx_skbs[i] = NULL; 1329 np->grant_rx_ref[i] = GRANT_INVALID_REF; 1330 } 1331 1332 /* A grant for every tx ring slot */ 1333 if (gnttab_alloc_grant_references(TX_MAX_TARGET, 1334 &np->gref_tx_head) < 0) { 1335 printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n"); 1336 err = -ENOMEM; 1337 goto exit_free_stats; 1338 } 1339 /* A grant for every rx ring slot */ 1340 if (gnttab_alloc_grant_references(RX_MAX_TARGET, 1341 &np->gref_rx_head) < 0) { 1342 printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n"); 1343 err = -ENOMEM; 1344 goto exit_free_tx; 1345 } 1346 1347 netdev->netdev_ops = &xennet_netdev_ops; 1348 1349 netif_napi_add(netdev, &np->napi, xennet_poll, 64); 1350 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1351 NETIF_F_GSO_ROBUST; 1352 netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO; 1353 1354 /* 1355 * Assume that all hw features are available for now. This set 1356 * will be adjusted by the call to netdev_update_features() in 1357 * xennet_connect() which is the earliest point where we can 1358 * negotiate with the backend regarding supported features. 1359 */ 1360 netdev->features |= netdev->hw_features; 1361 1362 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); 1363 SET_NETDEV_DEV(netdev, &dev->dev); 1364 1365 np->netdev = netdev; 1366 1367 netif_carrier_off(netdev); 1368 1369 return netdev; 1370 1371 exit_free_tx: 1372 gnttab_free_grant_references(np->gref_tx_head); 1373 exit_free_stats: 1374 free_percpu(np->stats); 1375 exit: 1376 free_netdev(netdev); 1377 return ERR_PTR(err); 1378 } 1379 1380 /** 1381 * Entry point to this code when a new device is created. Allocate the basic 1382 * structures and the ring buffers for communication with the backend, and 1383 * inform the backend of the appropriate details for those. 1384 */ 1385 static int netfront_probe(struct xenbus_device *dev, 1386 const struct xenbus_device_id *id) 1387 { 1388 int err; 1389 struct net_device *netdev; 1390 struct netfront_info *info; 1391 1392 netdev = xennet_create_dev(dev); 1393 if (IS_ERR(netdev)) { 1394 err = PTR_ERR(netdev); 1395 xenbus_dev_fatal(dev, err, "creating netdev"); 1396 return err; 1397 } 1398 1399 info = netdev_priv(netdev); 1400 dev_set_drvdata(&dev->dev, info); 1401 1402 err = register_netdev(info->netdev); 1403 if (err) { 1404 printk(KERN_WARNING "%s: register_netdev err=%d\n", 1405 __func__, err); 1406 goto fail; 1407 } 1408 1409 err = xennet_sysfs_addif(info->netdev); 1410 if (err) { 1411 unregister_netdev(info->netdev); 1412 printk(KERN_WARNING "%s: add sysfs failed err=%d\n", 1413 __func__, err); 1414 goto fail; 1415 } 1416 1417 return 0; 1418 1419 fail: 1420 free_netdev(netdev); 1421 dev_set_drvdata(&dev->dev, NULL); 1422 return err; 1423 } 1424 1425 static void xennet_end_access(int ref, void *page) 1426 { 1427 /* This frees the page as a side-effect */ 1428 if (ref != GRANT_INVALID_REF) 1429 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1430 } 1431 1432 static void xennet_disconnect_backend(struct netfront_info *info) 1433 { 1434 /* Stop old i/f to prevent errors whilst we rebuild the state. */ 1435 spin_lock_bh(&info->rx_lock); 1436 spin_lock_irq(&info->tx_lock); 1437 netif_carrier_off(info->netdev); 1438 spin_unlock_irq(&info->tx_lock); 1439 spin_unlock_bh(&info->rx_lock); 1440 1441 if (info->netdev->irq) 1442 unbind_from_irqhandler(info->netdev->irq, info->netdev); 1443 info->evtchn = info->netdev->irq = 0; 1444 1445 /* End access and free the pages */ 1446 xennet_end_access(info->tx_ring_ref, info->tx.sring); 1447 xennet_end_access(info->rx_ring_ref, info->rx.sring); 1448 1449 info->tx_ring_ref = GRANT_INVALID_REF; 1450 info->rx_ring_ref = GRANT_INVALID_REF; 1451 info->tx.sring = NULL; 1452 info->rx.sring = NULL; 1453 } 1454 1455 /** 1456 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1457 * driver restart. We tear down our netif structure and recreate it, but 1458 * leave the device-layer structures intact so that this is transparent to the 1459 * rest of the kernel. 1460 */ 1461 static int netfront_resume(struct xenbus_device *dev) 1462 { 1463 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1464 1465 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1466 1467 xennet_disconnect_backend(info); 1468 return 0; 1469 } 1470 1471 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1472 { 1473 char *s, *e, *macstr; 1474 int i; 1475 1476 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1477 if (IS_ERR(macstr)) 1478 return PTR_ERR(macstr); 1479 1480 for (i = 0; i < ETH_ALEN; i++) { 1481 mac[i] = simple_strtoul(s, &e, 16); 1482 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1483 kfree(macstr); 1484 return -ENOENT; 1485 } 1486 s = e+1; 1487 } 1488 1489 kfree(macstr); 1490 return 0; 1491 } 1492 1493 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) 1494 { 1495 struct xen_netif_tx_sring *txs; 1496 struct xen_netif_rx_sring *rxs; 1497 int err; 1498 struct net_device *netdev = info->netdev; 1499 1500 info->tx_ring_ref = GRANT_INVALID_REF; 1501 info->rx_ring_ref = GRANT_INVALID_REF; 1502 info->rx.sring = NULL; 1503 info->tx.sring = NULL; 1504 netdev->irq = 0; 1505 1506 err = xen_net_read_mac(dev, netdev->dev_addr); 1507 if (err) { 1508 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1509 goto fail; 1510 } 1511 1512 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1513 if (!txs) { 1514 err = -ENOMEM; 1515 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1516 goto fail; 1517 } 1518 SHARED_RING_INIT(txs); 1519 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE); 1520 1521 err = xenbus_grant_ring(dev, virt_to_mfn(txs)); 1522 if (err < 0) { 1523 free_page((unsigned long)txs); 1524 goto fail; 1525 } 1526 1527 info->tx_ring_ref = err; 1528 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1529 if (!rxs) { 1530 err = -ENOMEM; 1531 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1532 goto fail; 1533 } 1534 SHARED_RING_INIT(rxs); 1535 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE); 1536 1537 err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); 1538 if (err < 0) { 1539 free_page((unsigned long)rxs); 1540 goto fail; 1541 } 1542 info->rx_ring_ref = err; 1543 1544 err = xenbus_alloc_evtchn(dev, &info->evtchn); 1545 if (err) 1546 goto fail; 1547 1548 err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt, 1549 0, netdev->name, netdev); 1550 if (err < 0) 1551 goto fail; 1552 netdev->irq = err; 1553 return 0; 1554 1555 fail: 1556 return err; 1557 } 1558 1559 /* Common code used when first setting up, and when resuming. */ 1560 static int talk_to_netback(struct xenbus_device *dev, 1561 struct netfront_info *info) 1562 { 1563 const char *message; 1564 struct xenbus_transaction xbt; 1565 int err; 1566 1567 /* Create shared ring, alloc event channel. */ 1568 err = setup_netfront(dev, info); 1569 if (err) 1570 goto out; 1571 1572 again: 1573 err = xenbus_transaction_start(&xbt); 1574 if (err) { 1575 xenbus_dev_fatal(dev, err, "starting transaction"); 1576 goto destroy_ring; 1577 } 1578 1579 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u", 1580 info->tx_ring_ref); 1581 if (err) { 1582 message = "writing tx ring-ref"; 1583 goto abort_transaction; 1584 } 1585 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u", 1586 info->rx_ring_ref); 1587 if (err) { 1588 message = "writing rx ring-ref"; 1589 goto abort_transaction; 1590 } 1591 err = xenbus_printf(xbt, dev->nodename, 1592 "event-channel", "%u", info->evtchn); 1593 if (err) { 1594 message = "writing event-channel"; 1595 goto abort_transaction; 1596 } 1597 1598 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1599 1); 1600 if (err) { 1601 message = "writing request-rx-copy"; 1602 goto abort_transaction; 1603 } 1604 1605 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1606 if (err) { 1607 message = "writing feature-rx-notify"; 1608 goto abort_transaction; 1609 } 1610 1611 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1612 if (err) { 1613 message = "writing feature-sg"; 1614 goto abort_transaction; 1615 } 1616 1617 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1618 if (err) { 1619 message = "writing feature-gso-tcpv4"; 1620 goto abort_transaction; 1621 } 1622 1623 err = xenbus_transaction_end(xbt, 0); 1624 if (err) { 1625 if (err == -EAGAIN) 1626 goto again; 1627 xenbus_dev_fatal(dev, err, "completing transaction"); 1628 goto destroy_ring; 1629 } 1630 1631 return 0; 1632 1633 abort_transaction: 1634 xenbus_transaction_end(xbt, 1); 1635 xenbus_dev_fatal(dev, err, "%s", message); 1636 destroy_ring: 1637 xennet_disconnect_backend(info); 1638 out: 1639 return err; 1640 } 1641 1642 static int xennet_connect(struct net_device *dev) 1643 { 1644 struct netfront_info *np = netdev_priv(dev); 1645 int i, requeue_idx, err; 1646 struct sk_buff *skb; 1647 grant_ref_t ref; 1648 struct xen_netif_rx_request *req; 1649 unsigned int feature_rx_copy; 1650 1651 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1652 "feature-rx-copy", "%u", &feature_rx_copy); 1653 if (err != 1) 1654 feature_rx_copy = 0; 1655 1656 if (!feature_rx_copy) { 1657 dev_info(&dev->dev, 1658 "backend does not support copying receive path\n"); 1659 return -ENODEV; 1660 } 1661 1662 err = talk_to_netback(np->xbdev, np); 1663 if (err) 1664 return err; 1665 1666 rtnl_lock(); 1667 netdev_update_features(dev); 1668 rtnl_unlock(); 1669 1670 spin_lock_bh(&np->rx_lock); 1671 spin_lock_irq(&np->tx_lock); 1672 1673 /* Step 1: Discard all pending TX packet fragments. */ 1674 xennet_release_tx_bufs(np); 1675 1676 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ 1677 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { 1678 skb_frag_t *frag; 1679 const struct page *page; 1680 if (!np->rx_skbs[i]) 1681 continue; 1682 1683 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i); 1684 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i); 1685 req = RING_GET_REQUEST(&np->rx, requeue_idx); 1686 1687 frag = &skb_shinfo(skb)->frags[0]; 1688 page = skb_frag_page(frag); 1689 gnttab_grant_foreign_access_ref( 1690 ref, np->xbdev->otherend_id, 1691 pfn_to_mfn(page_to_pfn(page)), 1692 0); 1693 req->gref = ref; 1694 req->id = requeue_idx; 1695 1696 requeue_idx++; 1697 } 1698 1699 np->rx.req_prod_pvt = requeue_idx; 1700 1701 /* 1702 * Step 3: All public and private state should now be sane. Get 1703 * ready to start sending and receiving packets and give the driver 1704 * domain a kick because we've probably just requeued some 1705 * packets. 1706 */ 1707 netif_carrier_on(np->netdev); 1708 notify_remote_via_irq(np->netdev->irq); 1709 xennet_tx_buf_gc(dev); 1710 xennet_alloc_rx_buffers(dev); 1711 1712 spin_unlock_irq(&np->tx_lock); 1713 spin_unlock_bh(&np->rx_lock); 1714 1715 return 0; 1716 } 1717 1718 /** 1719 * Callback received when the backend's state changes. 1720 */ 1721 static void netback_changed(struct xenbus_device *dev, 1722 enum xenbus_state backend_state) 1723 { 1724 struct netfront_info *np = dev_get_drvdata(&dev->dev); 1725 struct net_device *netdev = np->netdev; 1726 1727 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 1728 1729 switch (backend_state) { 1730 case XenbusStateInitialising: 1731 case XenbusStateInitialised: 1732 case XenbusStateReconfiguring: 1733 case XenbusStateReconfigured: 1734 case XenbusStateUnknown: 1735 case XenbusStateClosed: 1736 break; 1737 1738 case XenbusStateInitWait: 1739 if (dev->state != XenbusStateInitialising) 1740 break; 1741 if (xennet_connect(netdev) != 0) 1742 break; 1743 xenbus_switch_state(dev, XenbusStateConnected); 1744 break; 1745 1746 case XenbusStateConnected: 1747 netdev_notify_peers(netdev); 1748 break; 1749 1750 case XenbusStateClosing: 1751 xenbus_frontend_closed(dev); 1752 break; 1753 } 1754 } 1755 1756 static const struct xennet_stat { 1757 char name[ETH_GSTRING_LEN]; 1758 u16 offset; 1759 } xennet_stats[] = { 1760 { 1761 "rx_gso_checksum_fixup", 1762 offsetof(struct netfront_info, rx_gso_checksum_fixup) 1763 }, 1764 }; 1765 1766 static int xennet_get_sset_count(struct net_device *dev, int string_set) 1767 { 1768 switch (string_set) { 1769 case ETH_SS_STATS: 1770 return ARRAY_SIZE(xennet_stats); 1771 default: 1772 return -EINVAL; 1773 } 1774 } 1775 1776 static void xennet_get_ethtool_stats(struct net_device *dev, 1777 struct ethtool_stats *stats, u64 * data) 1778 { 1779 void *np = netdev_priv(dev); 1780 int i; 1781 1782 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 1783 data[i] = *(unsigned long *)(np + xennet_stats[i].offset); 1784 } 1785 1786 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 1787 { 1788 int i; 1789 1790 switch (stringset) { 1791 case ETH_SS_STATS: 1792 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 1793 memcpy(data + i * ETH_GSTRING_LEN, 1794 xennet_stats[i].name, ETH_GSTRING_LEN); 1795 break; 1796 } 1797 } 1798 1799 static const struct ethtool_ops xennet_ethtool_ops = 1800 { 1801 .get_link = ethtool_op_get_link, 1802 1803 .get_sset_count = xennet_get_sset_count, 1804 .get_ethtool_stats = xennet_get_ethtool_stats, 1805 .get_strings = xennet_get_strings, 1806 }; 1807 1808 #ifdef CONFIG_SYSFS 1809 static ssize_t show_rxbuf_min(struct device *dev, 1810 struct device_attribute *attr, char *buf) 1811 { 1812 struct net_device *netdev = to_net_dev(dev); 1813 struct netfront_info *info = netdev_priv(netdev); 1814 1815 return sprintf(buf, "%u\n", info->rx_min_target); 1816 } 1817 1818 static ssize_t store_rxbuf_min(struct device *dev, 1819 struct device_attribute *attr, 1820 const char *buf, size_t len) 1821 { 1822 struct net_device *netdev = to_net_dev(dev); 1823 struct netfront_info *np = netdev_priv(netdev); 1824 char *endp; 1825 unsigned long target; 1826 1827 if (!capable(CAP_NET_ADMIN)) 1828 return -EPERM; 1829 1830 target = simple_strtoul(buf, &endp, 0); 1831 if (endp == buf) 1832 return -EBADMSG; 1833 1834 if (target < RX_MIN_TARGET) 1835 target = RX_MIN_TARGET; 1836 if (target > RX_MAX_TARGET) 1837 target = RX_MAX_TARGET; 1838 1839 spin_lock_bh(&np->rx_lock); 1840 if (target > np->rx_max_target) 1841 np->rx_max_target = target; 1842 np->rx_min_target = target; 1843 if (target > np->rx_target) 1844 np->rx_target = target; 1845 1846 xennet_alloc_rx_buffers(netdev); 1847 1848 spin_unlock_bh(&np->rx_lock); 1849 return len; 1850 } 1851 1852 static ssize_t show_rxbuf_max(struct device *dev, 1853 struct device_attribute *attr, char *buf) 1854 { 1855 struct net_device *netdev = to_net_dev(dev); 1856 struct netfront_info *info = netdev_priv(netdev); 1857 1858 return sprintf(buf, "%u\n", info->rx_max_target); 1859 } 1860 1861 static ssize_t store_rxbuf_max(struct device *dev, 1862 struct device_attribute *attr, 1863 const char *buf, size_t len) 1864 { 1865 struct net_device *netdev = to_net_dev(dev); 1866 struct netfront_info *np = netdev_priv(netdev); 1867 char *endp; 1868 unsigned long target; 1869 1870 if (!capable(CAP_NET_ADMIN)) 1871 return -EPERM; 1872 1873 target = simple_strtoul(buf, &endp, 0); 1874 if (endp == buf) 1875 return -EBADMSG; 1876 1877 if (target < RX_MIN_TARGET) 1878 target = RX_MIN_TARGET; 1879 if (target > RX_MAX_TARGET) 1880 target = RX_MAX_TARGET; 1881 1882 spin_lock_bh(&np->rx_lock); 1883 if (target < np->rx_min_target) 1884 np->rx_min_target = target; 1885 np->rx_max_target = target; 1886 if (target < np->rx_target) 1887 np->rx_target = target; 1888 1889 xennet_alloc_rx_buffers(netdev); 1890 1891 spin_unlock_bh(&np->rx_lock); 1892 return len; 1893 } 1894 1895 static ssize_t show_rxbuf_cur(struct device *dev, 1896 struct device_attribute *attr, char *buf) 1897 { 1898 struct net_device *netdev = to_net_dev(dev); 1899 struct netfront_info *info = netdev_priv(netdev); 1900 1901 return sprintf(buf, "%u\n", info->rx_target); 1902 } 1903 1904 static struct device_attribute xennet_attrs[] = { 1905 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), 1906 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), 1907 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), 1908 }; 1909 1910 static int xennet_sysfs_addif(struct net_device *netdev) 1911 { 1912 int i; 1913 int err; 1914 1915 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { 1916 err = device_create_file(&netdev->dev, 1917 &xennet_attrs[i]); 1918 if (err) 1919 goto fail; 1920 } 1921 return 0; 1922 1923 fail: 1924 while (--i >= 0) 1925 device_remove_file(&netdev->dev, &xennet_attrs[i]); 1926 return err; 1927 } 1928 1929 static void xennet_sysfs_delif(struct net_device *netdev) 1930 { 1931 int i; 1932 1933 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) 1934 device_remove_file(&netdev->dev, &xennet_attrs[i]); 1935 } 1936 1937 #endif /* CONFIG_SYSFS */ 1938 1939 static const struct xenbus_device_id netfront_ids[] = { 1940 { "vif" }, 1941 { "" } 1942 }; 1943 1944 1945 static int xennet_remove(struct xenbus_device *dev) 1946 { 1947 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1948 1949 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1950 1951 xennet_disconnect_backend(info); 1952 1953 xennet_sysfs_delif(info->netdev); 1954 1955 unregister_netdev(info->netdev); 1956 1957 del_timer_sync(&info->rx_refill_timer); 1958 1959 free_percpu(info->stats); 1960 1961 free_netdev(info->netdev); 1962 1963 return 0; 1964 } 1965 1966 static DEFINE_XENBUS_DRIVER(netfront, , 1967 .probe = netfront_probe, 1968 .remove = xennet_remove, 1969 .resume = netfront_resume, 1970 .otherend_changed = netback_changed, 1971 ); 1972 1973 static int __init netif_init(void) 1974 { 1975 if (!xen_domain()) 1976 return -ENODEV; 1977 1978 if (xen_hvm_domain() && !xen_platform_pci_unplug) 1979 return -ENODEV; 1980 1981 printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n"); 1982 1983 return xenbus_register_frontend(&netfront_driver); 1984 } 1985 module_init(netif_init); 1986 1987 1988 static void __exit netif_exit(void) 1989 { 1990 xenbus_unregister_driver(&netfront_driver); 1991 } 1992 module_exit(netif_exit); 1993 1994 MODULE_DESCRIPTION("Xen virtual network device frontend"); 1995 MODULE_LICENSE("GPL"); 1996 MODULE_ALIAS("xen:vif"); 1997 MODULE_ALIAS("xennet"); 1998