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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 34 #include <linux/module.h> 35 #include <linux/kernel.h> 36 #include <linux/netdevice.h> 37 #include <linux/etherdevice.h> 38 #include <linux/skbuff.h> 39 #include <linux/ethtool.h> 40 #include <linux/if_ether.h> 41 #include <net/tcp.h> 42 #include <linux/udp.h> 43 #include <linux/moduleparam.h> 44 #include <linux/mm.h> 45 #include <linux/slab.h> 46 #include <net/ip.h> 47 48 #include <asm/xen/page.h> 49 #include <xen/xen.h> 50 #include <xen/xenbus.h> 51 #include <xen/events.h> 52 #include <xen/page.h> 53 #include <xen/platform_pci.h> 54 #include <xen/grant_table.h> 55 56 #include <xen/interface/io/netif.h> 57 #include <xen/interface/memory.h> 58 #include <xen/interface/grant_table.h> 59 60 static const struct ethtool_ops xennet_ethtool_ops; 61 62 struct netfront_cb { 63 int pull_to; 64 }; 65 66 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 67 68 #define RX_COPY_THRESHOLD 256 69 70 #define GRANT_INVALID_REF 0 71 72 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) 73 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) 74 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256) 75 76 struct netfront_stats { 77 u64 rx_packets; 78 u64 tx_packets; 79 u64 rx_bytes; 80 u64 tx_bytes; 81 struct u64_stats_sync syncp; 82 }; 83 84 struct netfront_info { 85 struct list_head list; 86 struct net_device *netdev; 87 88 struct napi_struct napi; 89 90 /* Split event channels support, tx_* == rx_* when using 91 * single event channel. 92 */ 93 unsigned int tx_evtchn, rx_evtchn; 94 unsigned int tx_irq, rx_irq; 95 /* Only used when split event channels support is enabled */ 96 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */ 97 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ 98 99 struct xenbus_device *xbdev; 100 101 spinlock_t tx_lock; 102 struct xen_netif_tx_front_ring tx; 103 int tx_ring_ref; 104 105 /* 106 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 107 * are linked from tx_skb_freelist through skb_entry.link. 108 * 109 * NB. Freelist index entries are always going to be less than 110 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 111 * greater than PAGE_OFFSET: we use this property to distinguish 112 * them. 113 */ 114 union skb_entry { 115 struct sk_buff *skb; 116 unsigned long link; 117 } tx_skbs[NET_TX_RING_SIZE]; 118 grant_ref_t gref_tx_head; 119 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 120 struct page *grant_tx_page[NET_TX_RING_SIZE]; 121 unsigned tx_skb_freelist; 122 123 spinlock_t rx_lock ____cacheline_aligned_in_smp; 124 struct xen_netif_rx_front_ring rx; 125 int rx_ring_ref; 126 127 /* Receive-ring batched refills. */ 128 #define RX_MIN_TARGET 8 129 #define RX_DFL_MIN_TARGET 64 130 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) 131 unsigned rx_min_target, rx_max_target, rx_target; 132 struct sk_buff_head rx_batch; 133 134 struct timer_list rx_refill_timer; 135 136 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 137 grant_ref_t gref_rx_head; 138 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 139 140 unsigned long rx_pfn_array[NET_RX_RING_SIZE]; 141 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; 142 struct mmu_update rx_mmu[NET_RX_RING_SIZE]; 143 144 /* Statistics */ 145 struct netfront_stats __percpu *stats; 146 147 unsigned long rx_gso_checksum_fixup; 148 }; 149 150 struct netfront_rx_info { 151 struct xen_netif_rx_response rx; 152 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 153 }; 154 155 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 156 { 157 list->link = id; 158 } 159 160 static int skb_entry_is_link(const union skb_entry *list) 161 { 162 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 163 return (unsigned long)list->skb < PAGE_OFFSET; 164 } 165 166 /* 167 * Access macros for acquiring freeing slots in tx_skbs[]. 168 */ 169 170 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 171 unsigned short id) 172 { 173 skb_entry_set_link(&list[id], *head); 174 *head = id; 175 } 176 177 static unsigned short get_id_from_freelist(unsigned *head, 178 union skb_entry *list) 179 { 180 unsigned int id = *head; 181 *head = list[id].link; 182 return id; 183 } 184 185 static int xennet_rxidx(RING_IDX idx) 186 { 187 return idx & (NET_RX_RING_SIZE - 1); 188 } 189 190 static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np, 191 RING_IDX ri) 192 { 193 int i = xennet_rxidx(ri); 194 struct sk_buff *skb = np->rx_skbs[i]; 195 np->rx_skbs[i] = NULL; 196 return skb; 197 } 198 199 static grant_ref_t xennet_get_rx_ref(struct netfront_info *np, 200 RING_IDX ri) 201 { 202 int i = xennet_rxidx(ri); 203 grant_ref_t ref = np->grant_rx_ref[i]; 204 np->grant_rx_ref[i] = GRANT_INVALID_REF; 205 return ref; 206 } 207 208 #ifdef CONFIG_SYSFS 209 static int xennet_sysfs_addif(struct net_device *netdev); 210 static void xennet_sysfs_delif(struct net_device *netdev); 211 #else /* !CONFIG_SYSFS */ 212 #define xennet_sysfs_addif(dev) (0) 213 #define xennet_sysfs_delif(dev) do { } while (0) 214 #endif 215 216 static bool xennet_can_sg(struct net_device *dev) 217 { 218 return dev->features & NETIF_F_SG; 219 } 220 221 222 static void rx_refill_timeout(unsigned long data) 223 { 224 struct net_device *dev = (struct net_device *)data; 225 struct netfront_info *np = netdev_priv(dev); 226 napi_schedule(&np->napi); 227 } 228 229 static int netfront_tx_slot_available(struct netfront_info *np) 230 { 231 return (np->tx.req_prod_pvt - np->tx.rsp_cons) < 232 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2); 233 } 234 235 static void xennet_maybe_wake_tx(struct net_device *dev) 236 { 237 struct netfront_info *np = netdev_priv(dev); 238 239 if (unlikely(netif_queue_stopped(dev)) && 240 netfront_tx_slot_available(np) && 241 likely(netif_running(dev))) 242 netif_wake_queue(dev); 243 } 244 245 static void xennet_alloc_rx_buffers(struct net_device *dev) 246 { 247 unsigned short id; 248 struct netfront_info *np = netdev_priv(dev); 249 struct sk_buff *skb; 250 struct page *page; 251 int i, batch_target, notify; 252 RING_IDX req_prod = np->rx.req_prod_pvt; 253 grant_ref_t ref; 254 unsigned long pfn; 255 void *vaddr; 256 struct xen_netif_rx_request *req; 257 258 if (unlikely(!netif_carrier_ok(dev))) 259 return; 260 261 /* 262 * Allocate skbuffs greedily, even though we batch updates to the 263 * receive ring. This creates a less bursty demand on the memory 264 * allocator, so should reduce the chance of failed allocation requests 265 * both for ourself and for other kernel subsystems. 266 */ 267 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); 268 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { 269 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, 270 GFP_ATOMIC | __GFP_NOWARN); 271 if (unlikely(!skb)) 272 goto no_skb; 273 274 /* Align ip header to a 16 bytes boundary */ 275 skb_reserve(skb, NET_IP_ALIGN); 276 277 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 278 if (!page) { 279 kfree_skb(skb); 280 no_skb: 281 /* Could not allocate any skbuffs. Try again later. */ 282 mod_timer(&np->rx_refill_timer, 283 jiffies + (HZ/10)); 284 285 /* Any skbuffs queued for refill? Force them out. */ 286 if (i != 0) 287 goto refill; 288 break; 289 } 290 291 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 292 __skb_queue_tail(&np->rx_batch, skb); 293 } 294 295 /* Is the batch large enough to be worthwhile? */ 296 if (i < (np->rx_target/2)) { 297 if (req_prod > np->rx.sring->req_prod) 298 goto push; 299 return; 300 } 301 302 /* Adjust our fill target if we risked running out of buffers. */ 303 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && 304 ((np->rx_target *= 2) > np->rx_max_target)) 305 np->rx_target = np->rx_max_target; 306 307 refill: 308 for (i = 0; ; i++) { 309 skb = __skb_dequeue(&np->rx_batch); 310 if (skb == NULL) 311 break; 312 313 skb->dev = dev; 314 315 id = xennet_rxidx(req_prod + i); 316 317 BUG_ON(np->rx_skbs[id]); 318 np->rx_skbs[id] = skb; 319 320 ref = gnttab_claim_grant_reference(&np->gref_rx_head); 321 BUG_ON((signed short)ref < 0); 322 np->grant_rx_ref[id] = ref; 323 324 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); 325 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0])); 326 327 req = RING_GET_REQUEST(&np->rx, req_prod + i); 328 gnttab_grant_foreign_access_ref(ref, 329 np->xbdev->otherend_id, 330 pfn_to_mfn(pfn), 331 0); 332 333 req->id = id; 334 req->gref = ref; 335 } 336 337 wmb(); /* barrier so backend seens requests */ 338 339 /* Above is a suitable barrier to ensure backend will see requests. */ 340 np->rx.req_prod_pvt = req_prod + i; 341 push: 342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); 343 if (notify) 344 notify_remote_via_irq(np->rx_irq); 345 } 346 347 static int xennet_open(struct net_device *dev) 348 { 349 struct netfront_info *np = netdev_priv(dev); 350 351 napi_enable(&np->napi); 352 353 spin_lock_bh(&np->rx_lock); 354 if (netif_carrier_ok(dev)) { 355 xennet_alloc_rx_buffers(dev); 356 np->rx.sring->rsp_event = np->rx.rsp_cons + 1; 357 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) 358 napi_schedule(&np->napi); 359 } 360 spin_unlock_bh(&np->rx_lock); 361 362 netif_start_queue(dev); 363 364 return 0; 365 } 366 367 static void xennet_tx_buf_gc(struct net_device *dev) 368 { 369 RING_IDX cons, prod; 370 unsigned short id; 371 struct netfront_info *np = netdev_priv(dev); 372 struct sk_buff *skb; 373 374 BUG_ON(!netif_carrier_ok(dev)); 375 376 do { 377 prod = np->tx.sring->rsp_prod; 378 rmb(); /* Ensure we see responses up to 'rp'. */ 379 380 for (cons = np->tx.rsp_cons; cons != prod; cons++) { 381 struct xen_netif_tx_response *txrsp; 382 383 txrsp = RING_GET_RESPONSE(&np->tx, cons); 384 if (txrsp->status == XEN_NETIF_RSP_NULL) 385 continue; 386 387 id = txrsp->id; 388 skb = np->tx_skbs[id].skb; 389 if (unlikely(gnttab_query_foreign_access( 390 np->grant_tx_ref[id]) != 0)) { 391 pr_alert("%s: warning -- grant still in use by backend domain\n", 392 __func__); 393 BUG(); 394 } 395 gnttab_end_foreign_access_ref( 396 np->grant_tx_ref[id], GNTMAP_readonly); 397 gnttab_release_grant_reference( 398 &np->gref_tx_head, np->grant_tx_ref[id]); 399 np->grant_tx_ref[id] = GRANT_INVALID_REF; 400 np->grant_tx_page[id] = NULL; 401 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); 402 dev_kfree_skb_irq(skb); 403 } 404 405 np->tx.rsp_cons = prod; 406 407 /* 408 * Set a new event, then check for race with update of tx_cons. 409 * Note that it is essential to schedule a callback, no matter 410 * how few buffers are pending. Even if there is space in the 411 * transmit ring, higher layers may be blocked because too much 412 * data is outstanding: in such cases notification from Xen is 413 * likely to be the only kick that we'll get. 414 */ 415 np->tx.sring->rsp_event = 416 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1; 417 mb(); /* update shared area */ 418 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); 419 420 xennet_maybe_wake_tx(dev); 421 } 422 423 static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, 424 struct xen_netif_tx_request *tx) 425 { 426 struct netfront_info *np = netdev_priv(dev); 427 char *data = skb->data; 428 unsigned long mfn; 429 RING_IDX prod = np->tx.req_prod_pvt; 430 int frags = skb_shinfo(skb)->nr_frags; 431 unsigned int offset = offset_in_page(data); 432 unsigned int len = skb_headlen(skb); 433 unsigned int id; 434 grant_ref_t ref; 435 int i; 436 437 /* While the header overlaps a page boundary (including being 438 larger than a page), split it it into page-sized chunks. */ 439 while (len > PAGE_SIZE - offset) { 440 tx->size = PAGE_SIZE - offset; 441 tx->flags |= XEN_NETTXF_more_data; 442 len -= tx->size; 443 data += tx->size; 444 offset = 0; 445 446 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 447 np->tx_skbs[id].skb = skb_get(skb); 448 tx = RING_GET_REQUEST(&np->tx, prod++); 449 tx->id = id; 450 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 451 BUG_ON((signed short)ref < 0); 452 453 mfn = virt_to_mfn(data); 454 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, 455 mfn, GNTMAP_readonly); 456 457 np->grant_tx_page[id] = virt_to_page(data); 458 tx->gref = np->grant_tx_ref[id] = ref; 459 tx->offset = offset; 460 tx->size = len; 461 tx->flags = 0; 462 } 463 464 /* Grant backend access to each skb fragment page. */ 465 for (i = 0; i < frags; i++) { 466 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 467 struct page *page = skb_frag_page(frag); 468 469 len = skb_frag_size(frag); 470 offset = frag->page_offset; 471 472 /* Data must not cross a page boundary. */ 473 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); 474 475 /* Skip unused frames from start of page */ 476 page += offset >> PAGE_SHIFT; 477 offset &= ~PAGE_MASK; 478 479 while (len > 0) { 480 unsigned long bytes; 481 482 BUG_ON(offset >= PAGE_SIZE); 483 484 bytes = PAGE_SIZE - offset; 485 if (bytes > len) 486 bytes = len; 487 488 tx->flags |= XEN_NETTXF_more_data; 489 490 id = get_id_from_freelist(&np->tx_skb_freelist, 491 np->tx_skbs); 492 np->tx_skbs[id].skb = skb_get(skb); 493 tx = RING_GET_REQUEST(&np->tx, prod++); 494 tx->id = id; 495 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 496 BUG_ON((signed short)ref < 0); 497 498 mfn = pfn_to_mfn(page_to_pfn(page)); 499 gnttab_grant_foreign_access_ref(ref, 500 np->xbdev->otherend_id, 501 mfn, GNTMAP_readonly); 502 503 np->grant_tx_page[id] = page; 504 tx->gref = np->grant_tx_ref[id] = ref; 505 tx->offset = offset; 506 tx->size = bytes; 507 tx->flags = 0; 508 509 offset += bytes; 510 len -= bytes; 511 512 /* Next frame */ 513 if (offset == PAGE_SIZE && len) { 514 BUG_ON(!PageCompound(page)); 515 page++; 516 offset = 0; 517 } 518 } 519 } 520 521 np->tx.req_prod_pvt = prod; 522 } 523 524 /* 525 * Count how many ring slots are required to send the frags of this 526 * skb. Each frag might be a compound page. 527 */ 528 static int xennet_count_skb_frag_slots(struct sk_buff *skb) 529 { 530 int i, frags = skb_shinfo(skb)->nr_frags; 531 int pages = 0; 532 533 for (i = 0; i < frags; i++) { 534 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 535 unsigned long size = skb_frag_size(frag); 536 unsigned long offset = frag->page_offset; 537 538 /* Skip unused frames from start of page */ 539 offset &= ~PAGE_MASK; 540 541 pages += PFN_UP(offset + size); 542 } 543 544 return pages; 545 } 546 547 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 548 { 549 unsigned short id; 550 struct netfront_info *np = netdev_priv(dev); 551 struct netfront_stats *stats = this_cpu_ptr(np->stats); 552 struct xen_netif_tx_request *tx; 553 char *data = skb->data; 554 RING_IDX i; 555 grant_ref_t ref; 556 unsigned long mfn; 557 int notify; 558 int slots; 559 unsigned int offset = offset_in_page(data); 560 unsigned int len = skb_headlen(skb); 561 unsigned long flags; 562 563 /* If skb->len is too big for wire format, drop skb and alert 564 * user about misconfiguration. 565 */ 566 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 567 net_alert_ratelimited( 568 "xennet: skb->len = %u, too big for wire format\n", 569 skb->len); 570 goto drop; 571 } 572 573 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + 574 xennet_count_skb_frag_slots(skb); 575 if (unlikely(slots > MAX_SKB_FRAGS + 1)) { 576 net_alert_ratelimited( 577 "xennet: skb rides the rocket: %d slots\n", slots); 578 goto drop; 579 } 580 581 spin_lock_irqsave(&np->tx_lock, flags); 582 583 if (unlikely(!netif_carrier_ok(dev) || 584 (slots > 1 && !xennet_can_sg(dev)) || 585 netif_needs_gso(skb, netif_skb_features(skb)))) { 586 spin_unlock_irqrestore(&np->tx_lock, flags); 587 goto drop; 588 } 589 590 i = np->tx.req_prod_pvt; 591 592 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); 593 np->tx_skbs[id].skb = skb; 594 595 tx = RING_GET_REQUEST(&np->tx, i); 596 597 tx->id = id; 598 ref = gnttab_claim_grant_reference(&np->gref_tx_head); 599 BUG_ON((signed short)ref < 0); 600 mfn = virt_to_mfn(data); 601 gnttab_grant_foreign_access_ref( 602 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); 603 np->grant_tx_page[id] = virt_to_page(data); 604 tx->gref = np->grant_tx_ref[id] = ref; 605 tx->offset = offset; 606 tx->size = len; 607 608 tx->flags = 0; 609 if (skb->ip_summed == CHECKSUM_PARTIAL) 610 /* local packet? */ 611 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 612 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 613 /* remote but checksummed. */ 614 tx->flags |= XEN_NETTXF_data_validated; 615 616 if (skb_shinfo(skb)->gso_size) { 617 struct xen_netif_extra_info *gso; 618 619 gso = (struct xen_netif_extra_info *) 620 RING_GET_REQUEST(&np->tx, ++i); 621 622 tx->flags |= XEN_NETTXF_extra_info; 623 624 gso->u.gso.size = skb_shinfo(skb)->gso_size; 625 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 626 XEN_NETIF_GSO_TYPE_TCPV6 : 627 XEN_NETIF_GSO_TYPE_TCPV4; 628 gso->u.gso.pad = 0; 629 gso->u.gso.features = 0; 630 631 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 632 gso->flags = 0; 633 } 634 635 np->tx.req_prod_pvt = i + 1; 636 637 xennet_make_frags(skb, dev, tx); 638 tx->size = skb->len; 639 640 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); 641 if (notify) 642 notify_remote_via_irq(np->tx_irq); 643 644 u64_stats_update_begin(&stats->syncp); 645 stats->tx_bytes += skb->len; 646 stats->tx_packets++; 647 u64_stats_update_end(&stats->syncp); 648 649 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 650 xennet_tx_buf_gc(dev); 651 652 if (!netfront_tx_slot_available(np)) 653 netif_stop_queue(dev); 654 655 spin_unlock_irqrestore(&np->tx_lock, flags); 656 657 return NETDEV_TX_OK; 658 659 drop: 660 dev->stats.tx_dropped++; 661 dev_kfree_skb_any(skb); 662 return NETDEV_TX_OK; 663 } 664 665 static int xennet_close(struct net_device *dev) 666 { 667 struct netfront_info *np = netdev_priv(dev); 668 netif_stop_queue(np->netdev); 669 napi_disable(&np->napi); 670 return 0; 671 } 672 673 static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb, 674 grant_ref_t ref) 675 { 676 int new = xennet_rxidx(np->rx.req_prod_pvt); 677 678 BUG_ON(np->rx_skbs[new]); 679 np->rx_skbs[new] = skb; 680 np->grant_rx_ref[new] = ref; 681 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new; 682 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref; 683 np->rx.req_prod_pvt++; 684 } 685 686 static int xennet_get_extras(struct netfront_info *np, 687 struct xen_netif_extra_info *extras, 688 RING_IDX rp) 689 690 { 691 struct xen_netif_extra_info *extra; 692 struct device *dev = &np->netdev->dev; 693 RING_IDX cons = np->rx.rsp_cons; 694 int err = 0; 695 696 do { 697 struct sk_buff *skb; 698 grant_ref_t ref; 699 700 if (unlikely(cons + 1 == rp)) { 701 if (net_ratelimit()) 702 dev_warn(dev, "Missing extra info\n"); 703 err = -EBADR; 704 break; 705 } 706 707 extra = (struct xen_netif_extra_info *) 708 RING_GET_RESPONSE(&np->rx, ++cons); 709 710 if (unlikely(!extra->type || 711 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 712 if (net_ratelimit()) 713 dev_warn(dev, "Invalid extra type: %d\n", 714 extra->type); 715 err = -EINVAL; 716 } else { 717 memcpy(&extras[extra->type - 1], extra, 718 sizeof(*extra)); 719 } 720 721 skb = xennet_get_rx_skb(np, cons); 722 ref = xennet_get_rx_ref(np, cons); 723 xennet_move_rx_slot(np, skb, ref); 724 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 725 726 np->rx.rsp_cons = cons; 727 return err; 728 } 729 730 static int xennet_get_responses(struct netfront_info *np, 731 struct netfront_rx_info *rinfo, RING_IDX rp, 732 struct sk_buff_head *list) 733 { 734 struct xen_netif_rx_response *rx = &rinfo->rx; 735 struct xen_netif_extra_info *extras = rinfo->extras; 736 struct device *dev = &np->netdev->dev; 737 RING_IDX cons = np->rx.rsp_cons; 738 struct sk_buff *skb = xennet_get_rx_skb(np, cons); 739 grant_ref_t ref = xennet_get_rx_ref(np, cons); 740 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 741 int slots = 1; 742 int err = 0; 743 unsigned long ret; 744 745 if (rx->flags & XEN_NETRXF_extra_info) { 746 err = xennet_get_extras(np, extras, rp); 747 cons = np->rx.rsp_cons; 748 } 749 750 for (;;) { 751 if (unlikely(rx->status < 0 || 752 rx->offset + rx->status > PAGE_SIZE)) { 753 if (net_ratelimit()) 754 dev_warn(dev, "rx->offset: %x, size: %u\n", 755 rx->offset, rx->status); 756 xennet_move_rx_slot(np, skb, ref); 757 err = -EINVAL; 758 goto next; 759 } 760 761 /* 762 * This definitely indicates a bug, either in this driver or in 763 * the backend driver. In future this should flag the bad 764 * situation to the system controller to reboot the backend. 765 */ 766 if (ref == GRANT_INVALID_REF) { 767 if (net_ratelimit()) 768 dev_warn(dev, "Bad rx response id %d.\n", 769 rx->id); 770 err = -EINVAL; 771 goto next; 772 } 773 774 ret = gnttab_end_foreign_access_ref(ref, 0); 775 BUG_ON(!ret); 776 777 gnttab_release_grant_reference(&np->gref_rx_head, ref); 778 779 __skb_queue_tail(list, skb); 780 781 next: 782 if (!(rx->flags & XEN_NETRXF_more_data)) 783 break; 784 785 if (cons + slots == rp) { 786 if (net_ratelimit()) 787 dev_warn(dev, "Need more slots\n"); 788 err = -ENOENT; 789 break; 790 } 791 792 rx = RING_GET_RESPONSE(&np->rx, cons + slots); 793 skb = xennet_get_rx_skb(np, cons + slots); 794 ref = xennet_get_rx_ref(np, cons + slots); 795 slots++; 796 } 797 798 if (unlikely(slots > max)) { 799 if (net_ratelimit()) 800 dev_warn(dev, "Too many slots\n"); 801 err = -E2BIG; 802 } 803 804 if (unlikely(err)) 805 np->rx.rsp_cons = cons + slots; 806 807 return err; 808 } 809 810 static int xennet_set_skb_gso(struct sk_buff *skb, 811 struct xen_netif_extra_info *gso) 812 { 813 if (!gso->u.gso.size) { 814 if (net_ratelimit()) 815 pr_warn("GSO size must not be zero\n"); 816 return -EINVAL; 817 } 818 819 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 820 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 821 if (net_ratelimit()) 822 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 823 return -EINVAL; 824 } 825 826 skb_shinfo(skb)->gso_size = gso->u.gso.size; 827 skb_shinfo(skb)->gso_type = 828 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 829 SKB_GSO_TCPV4 : 830 SKB_GSO_TCPV6; 831 832 /* Header must be checked, and gso_segs computed. */ 833 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 834 skb_shinfo(skb)->gso_segs = 0; 835 836 return 0; 837 } 838 839 static RING_IDX xennet_fill_frags(struct netfront_info *np, 840 struct sk_buff *skb, 841 struct sk_buff_head *list) 842 { 843 struct skb_shared_info *shinfo = skb_shinfo(skb); 844 RING_IDX cons = np->rx.rsp_cons; 845 struct sk_buff *nskb; 846 847 while ((nskb = __skb_dequeue(list))) { 848 struct xen_netif_rx_response *rx = 849 RING_GET_RESPONSE(&np->rx, ++cons); 850 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 851 852 if (shinfo->nr_frags == MAX_SKB_FRAGS) { 853 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 854 855 BUG_ON(pull_to <= skb_headlen(skb)); 856 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 857 } 858 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); 859 860 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), 861 rx->offset, rx->status, PAGE_SIZE); 862 863 skb_shinfo(nskb)->nr_frags = 0; 864 kfree_skb(nskb); 865 } 866 867 return cons; 868 } 869 870 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 871 { 872 bool recalculate_partial_csum = false; 873 874 /* 875 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 876 * peers can fail to set NETRXF_csum_blank when sending a GSO 877 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 878 * recalculate the partial checksum. 879 */ 880 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 881 struct netfront_info *np = netdev_priv(dev); 882 np->rx_gso_checksum_fixup++; 883 skb->ip_summed = CHECKSUM_PARTIAL; 884 recalculate_partial_csum = true; 885 } 886 887 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 888 if (skb->ip_summed != CHECKSUM_PARTIAL) 889 return 0; 890 891 return skb_checksum_setup(skb, recalculate_partial_csum); 892 } 893 894 static int handle_incoming_queue(struct net_device *dev, 895 struct sk_buff_head *rxq) 896 { 897 struct netfront_info *np = netdev_priv(dev); 898 struct netfront_stats *stats = this_cpu_ptr(np->stats); 899 int packets_dropped = 0; 900 struct sk_buff *skb; 901 902 while ((skb = __skb_dequeue(rxq)) != NULL) { 903 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 904 905 if (pull_to > skb_headlen(skb)) 906 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 907 908 /* Ethernet work: Delayed to here as it peeks the header. */ 909 skb->protocol = eth_type_trans(skb, dev); 910 skb_reset_network_header(skb); 911 912 if (checksum_setup(dev, skb)) { 913 kfree_skb(skb); 914 packets_dropped++; 915 dev->stats.rx_errors++; 916 continue; 917 } 918 919 u64_stats_update_begin(&stats->syncp); 920 stats->rx_packets++; 921 stats->rx_bytes += skb->len; 922 u64_stats_update_end(&stats->syncp); 923 924 /* Pass it up. */ 925 napi_gro_receive(&np->napi, skb); 926 } 927 928 return packets_dropped; 929 } 930 931 static int xennet_poll(struct napi_struct *napi, int budget) 932 { 933 struct netfront_info *np = container_of(napi, struct netfront_info, napi); 934 struct net_device *dev = np->netdev; 935 struct sk_buff *skb; 936 struct netfront_rx_info rinfo; 937 struct xen_netif_rx_response *rx = &rinfo.rx; 938 struct xen_netif_extra_info *extras = rinfo.extras; 939 RING_IDX i, rp; 940 int work_done; 941 struct sk_buff_head rxq; 942 struct sk_buff_head errq; 943 struct sk_buff_head tmpq; 944 unsigned long flags; 945 int err; 946 947 spin_lock(&np->rx_lock); 948 949 skb_queue_head_init(&rxq); 950 skb_queue_head_init(&errq); 951 skb_queue_head_init(&tmpq); 952 953 rp = np->rx.sring->rsp_prod; 954 rmb(); /* Ensure we see queued responses up to 'rp'. */ 955 956 i = np->rx.rsp_cons; 957 work_done = 0; 958 while ((i != rp) && (work_done < budget)) { 959 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx)); 960 memset(extras, 0, sizeof(rinfo.extras)); 961 962 err = xennet_get_responses(np, &rinfo, rp, &tmpq); 963 964 if (unlikely(err)) { 965 err: 966 while ((skb = __skb_dequeue(&tmpq))) 967 __skb_queue_tail(&errq, skb); 968 dev->stats.rx_errors++; 969 i = np->rx.rsp_cons; 970 continue; 971 } 972 973 skb = __skb_dequeue(&tmpq); 974 975 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 976 struct xen_netif_extra_info *gso; 977 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 978 979 if (unlikely(xennet_set_skb_gso(skb, gso))) { 980 __skb_queue_head(&tmpq, skb); 981 np->rx.rsp_cons += skb_queue_len(&tmpq); 982 goto err; 983 } 984 } 985 986 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 987 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 988 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 989 990 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 991 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 992 skb->data_len = rx->status; 993 skb->len += rx->status; 994 995 i = xennet_fill_frags(np, skb, &tmpq); 996 997 if (rx->flags & XEN_NETRXF_csum_blank) 998 skb->ip_summed = CHECKSUM_PARTIAL; 999 else if (rx->flags & XEN_NETRXF_data_validated) 1000 skb->ip_summed = CHECKSUM_UNNECESSARY; 1001 1002 __skb_queue_tail(&rxq, skb); 1003 1004 np->rx.rsp_cons = ++i; 1005 work_done++; 1006 } 1007 1008 __skb_queue_purge(&errq); 1009 1010 work_done -= handle_incoming_queue(dev, &rxq); 1011 1012 /* If we get a callback with very few responses, reduce fill target. */ 1013 /* NB. Note exponential increase, linear decrease. */ 1014 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > 1015 ((3*np->rx_target) / 4)) && 1016 (--np->rx_target < np->rx_min_target)) 1017 np->rx_target = np->rx_min_target; 1018 1019 xennet_alloc_rx_buffers(dev); 1020 1021 if (work_done < budget) { 1022 int more_to_do = 0; 1023 1024 napi_gro_flush(napi, false); 1025 1026 local_irq_save(flags); 1027 1028 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); 1029 if (!more_to_do) 1030 __napi_complete(napi); 1031 1032 local_irq_restore(flags); 1033 } 1034 1035 spin_unlock(&np->rx_lock); 1036 1037 return work_done; 1038 } 1039 1040 static int xennet_change_mtu(struct net_device *dev, int mtu) 1041 { 1042 int max = xennet_can_sg(dev) ? 1043 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; 1044 1045 if (mtu > max) 1046 return -EINVAL; 1047 dev->mtu = mtu; 1048 return 0; 1049 } 1050 1051 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, 1052 struct rtnl_link_stats64 *tot) 1053 { 1054 struct netfront_info *np = netdev_priv(dev); 1055 int cpu; 1056 1057 for_each_possible_cpu(cpu) { 1058 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu); 1059 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1060 unsigned int start; 1061 1062 do { 1063 start = u64_stats_fetch_begin_irq(&stats->syncp); 1064 1065 rx_packets = stats->rx_packets; 1066 tx_packets = stats->tx_packets; 1067 rx_bytes = stats->rx_bytes; 1068 tx_bytes = stats->tx_bytes; 1069 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 1070 1071 tot->rx_packets += rx_packets; 1072 tot->tx_packets += tx_packets; 1073 tot->rx_bytes += rx_bytes; 1074 tot->tx_bytes += tx_bytes; 1075 } 1076 1077 tot->rx_errors = dev->stats.rx_errors; 1078 tot->tx_dropped = dev->stats.tx_dropped; 1079 1080 return tot; 1081 } 1082 1083 static void xennet_release_tx_bufs(struct netfront_info *np) 1084 { 1085 struct sk_buff *skb; 1086 int i; 1087 1088 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1089 /* Skip over entries which are actually freelist references */ 1090 if (skb_entry_is_link(&np->tx_skbs[i])) 1091 continue; 1092 1093 skb = np->tx_skbs[i].skb; 1094 get_page(np->grant_tx_page[i]); 1095 gnttab_end_foreign_access(np->grant_tx_ref[i], 1096 GNTMAP_readonly, 1097 (unsigned long)page_address(np->grant_tx_page[i])); 1098 np->grant_tx_page[i] = NULL; 1099 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1100 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); 1101 dev_kfree_skb_irq(skb); 1102 } 1103 } 1104 1105 static void xennet_release_rx_bufs(struct netfront_info *np) 1106 { 1107 int id, ref; 1108 1109 spin_lock_bh(&np->rx_lock); 1110 1111 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1112 struct sk_buff *skb; 1113 struct page *page; 1114 1115 skb = np->rx_skbs[id]; 1116 if (!skb) 1117 continue; 1118 1119 ref = np->grant_rx_ref[id]; 1120 if (ref == GRANT_INVALID_REF) 1121 continue; 1122 1123 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1124 1125 /* gnttab_end_foreign_access() needs a page ref until 1126 * foreign access is ended (which may be deferred). 1127 */ 1128 get_page(page); 1129 gnttab_end_foreign_access(ref, 0, 1130 (unsigned long)page_address(page)); 1131 np->grant_rx_ref[id] = GRANT_INVALID_REF; 1132 1133 kfree_skb(skb); 1134 } 1135 1136 spin_unlock_bh(&np->rx_lock); 1137 } 1138 1139 static void xennet_uninit(struct net_device *dev) 1140 { 1141 struct netfront_info *np = netdev_priv(dev); 1142 xennet_release_tx_bufs(np); 1143 xennet_release_rx_bufs(np); 1144 gnttab_free_grant_references(np->gref_tx_head); 1145 gnttab_free_grant_references(np->gref_rx_head); 1146 } 1147 1148 static netdev_features_t xennet_fix_features(struct net_device *dev, 1149 netdev_features_t features) 1150 { 1151 struct netfront_info *np = netdev_priv(dev); 1152 int val; 1153 1154 if (features & NETIF_F_SG) { 1155 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1156 "%d", &val) < 0) 1157 val = 0; 1158 1159 if (!val) 1160 features &= ~NETIF_F_SG; 1161 } 1162 1163 if (features & NETIF_F_IPV6_CSUM) { 1164 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1165 "feature-ipv6-csum-offload", "%d", &val) < 0) 1166 val = 0; 1167 1168 if (!val) 1169 features &= ~NETIF_F_IPV6_CSUM; 1170 } 1171 1172 if (features & NETIF_F_TSO) { 1173 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1174 "feature-gso-tcpv4", "%d", &val) < 0) 1175 val = 0; 1176 1177 if (!val) 1178 features &= ~NETIF_F_TSO; 1179 } 1180 1181 if (features & NETIF_F_TSO6) { 1182 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1183 "feature-gso-tcpv6", "%d", &val) < 0) 1184 val = 0; 1185 1186 if (!val) 1187 features &= ~NETIF_F_TSO6; 1188 } 1189 1190 return features; 1191 } 1192 1193 static int xennet_set_features(struct net_device *dev, 1194 netdev_features_t features) 1195 { 1196 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1197 netdev_info(dev, "Reducing MTU because no SG offload"); 1198 dev->mtu = ETH_DATA_LEN; 1199 } 1200 1201 return 0; 1202 } 1203 1204 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1205 { 1206 struct netfront_info *np = dev_id; 1207 struct net_device *dev = np->netdev; 1208 unsigned long flags; 1209 1210 spin_lock_irqsave(&np->tx_lock, flags); 1211 xennet_tx_buf_gc(dev); 1212 spin_unlock_irqrestore(&np->tx_lock, flags); 1213 1214 return IRQ_HANDLED; 1215 } 1216 1217 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1218 { 1219 struct netfront_info *np = dev_id; 1220 struct net_device *dev = np->netdev; 1221 1222 if (likely(netif_carrier_ok(dev) && 1223 RING_HAS_UNCONSUMED_RESPONSES(&np->rx))) 1224 napi_schedule(&np->napi); 1225 1226 return IRQ_HANDLED; 1227 } 1228 1229 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1230 { 1231 xennet_tx_interrupt(irq, dev_id); 1232 xennet_rx_interrupt(irq, dev_id); 1233 return IRQ_HANDLED; 1234 } 1235 1236 #ifdef CONFIG_NET_POLL_CONTROLLER 1237 static void xennet_poll_controller(struct net_device *dev) 1238 { 1239 xennet_interrupt(0, dev); 1240 } 1241 #endif 1242 1243 static const struct net_device_ops xennet_netdev_ops = { 1244 .ndo_open = xennet_open, 1245 .ndo_uninit = xennet_uninit, 1246 .ndo_stop = xennet_close, 1247 .ndo_start_xmit = xennet_start_xmit, 1248 .ndo_change_mtu = xennet_change_mtu, 1249 .ndo_get_stats64 = xennet_get_stats64, 1250 .ndo_set_mac_address = eth_mac_addr, 1251 .ndo_validate_addr = eth_validate_addr, 1252 .ndo_fix_features = xennet_fix_features, 1253 .ndo_set_features = xennet_set_features, 1254 #ifdef CONFIG_NET_POLL_CONTROLLER 1255 .ndo_poll_controller = xennet_poll_controller, 1256 #endif 1257 }; 1258 1259 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1260 { 1261 int i, err; 1262 struct net_device *netdev; 1263 struct netfront_info *np; 1264 1265 netdev = alloc_etherdev(sizeof(struct netfront_info)); 1266 if (!netdev) 1267 return ERR_PTR(-ENOMEM); 1268 1269 np = netdev_priv(netdev); 1270 np->xbdev = dev; 1271 1272 spin_lock_init(&np->tx_lock); 1273 spin_lock_init(&np->rx_lock); 1274 1275 skb_queue_head_init(&np->rx_batch); 1276 np->rx_target = RX_DFL_MIN_TARGET; 1277 np->rx_min_target = RX_DFL_MIN_TARGET; 1278 np->rx_max_target = RX_MAX_TARGET; 1279 1280 init_timer(&np->rx_refill_timer); 1281 np->rx_refill_timer.data = (unsigned long)netdev; 1282 np->rx_refill_timer.function = rx_refill_timeout; 1283 1284 err = -ENOMEM; 1285 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1286 if (np->stats == NULL) 1287 goto exit; 1288 1289 /* Initialise tx_skbs as a free chain containing every entry. */ 1290 np->tx_skb_freelist = 0; 1291 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1292 skb_entry_set_link(&np->tx_skbs[i], i+1); 1293 np->grant_tx_ref[i] = GRANT_INVALID_REF; 1294 np->grant_tx_page[i] = NULL; 1295 } 1296 1297 /* Clear out rx_skbs */ 1298 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1299 np->rx_skbs[i] = NULL; 1300 np->grant_rx_ref[i] = GRANT_INVALID_REF; 1301 } 1302 1303 /* A grant for every tx ring slot */ 1304 if (gnttab_alloc_grant_references(TX_MAX_TARGET, 1305 &np->gref_tx_head) < 0) { 1306 pr_alert("can't alloc tx grant refs\n"); 1307 err = -ENOMEM; 1308 goto exit_free_stats; 1309 } 1310 /* A grant for every rx ring slot */ 1311 if (gnttab_alloc_grant_references(RX_MAX_TARGET, 1312 &np->gref_rx_head) < 0) { 1313 pr_alert("can't alloc rx grant refs\n"); 1314 err = -ENOMEM; 1315 goto exit_free_tx; 1316 } 1317 1318 netdev->netdev_ops = &xennet_netdev_ops; 1319 1320 netif_napi_add(netdev, &np->napi, xennet_poll, 64); 1321 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1322 NETIF_F_GSO_ROBUST; 1323 netdev->hw_features = NETIF_F_SG | 1324 NETIF_F_IPV6_CSUM | 1325 NETIF_F_TSO | NETIF_F_TSO6; 1326 1327 /* 1328 * Assume that all hw features are available for now. This set 1329 * will be adjusted by the call to netdev_update_features() in 1330 * xennet_connect() which is the earliest point where we can 1331 * negotiate with the backend regarding supported features. 1332 */ 1333 netdev->features |= netdev->hw_features; 1334 1335 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); 1336 SET_NETDEV_DEV(netdev, &dev->dev); 1337 1338 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); 1339 1340 np->netdev = netdev; 1341 1342 netif_carrier_off(netdev); 1343 1344 return netdev; 1345 1346 exit_free_tx: 1347 gnttab_free_grant_references(np->gref_tx_head); 1348 exit_free_stats: 1349 free_percpu(np->stats); 1350 exit: 1351 free_netdev(netdev); 1352 return ERR_PTR(err); 1353 } 1354 1355 /** 1356 * Entry point to this code when a new device is created. Allocate the basic 1357 * structures and the ring buffers for communication with the backend, and 1358 * inform the backend of the appropriate details for those. 1359 */ 1360 static int netfront_probe(struct xenbus_device *dev, 1361 const struct xenbus_device_id *id) 1362 { 1363 int err; 1364 struct net_device *netdev; 1365 struct netfront_info *info; 1366 1367 netdev = xennet_create_dev(dev); 1368 if (IS_ERR(netdev)) { 1369 err = PTR_ERR(netdev); 1370 xenbus_dev_fatal(dev, err, "creating netdev"); 1371 return err; 1372 } 1373 1374 info = netdev_priv(netdev); 1375 dev_set_drvdata(&dev->dev, info); 1376 1377 err = register_netdev(info->netdev); 1378 if (err) { 1379 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1380 goto fail; 1381 } 1382 1383 err = xennet_sysfs_addif(info->netdev); 1384 if (err) { 1385 unregister_netdev(info->netdev); 1386 pr_warn("%s: add sysfs failed err=%d\n", __func__, err); 1387 goto fail; 1388 } 1389 1390 return 0; 1391 1392 fail: 1393 free_netdev(netdev); 1394 dev_set_drvdata(&dev->dev, NULL); 1395 return err; 1396 } 1397 1398 static void xennet_end_access(int ref, void *page) 1399 { 1400 /* This frees the page as a side-effect */ 1401 if (ref != GRANT_INVALID_REF) 1402 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1403 } 1404 1405 static void xennet_disconnect_backend(struct netfront_info *info) 1406 { 1407 /* Stop old i/f to prevent errors whilst we rebuild the state. */ 1408 spin_lock_bh(&info->rx_lock); 1409 spin_lock_irq(&info->tx_lock); 1410 netif_carrier_off(info->netdev); 1411 spin_unlock_irq(&info->tx_lock); 1412 spin_unlock_bh(&info->rx_lock); 1413 1414 if (info->tx_irq && (info->tx_irq == info->rx_irq)) 1415 unbind_from_irqhandler(info->tx_irq, info); 1416 if (info->tx_irq && (info->tx_irq != info->rx_irq)) { 1417 unbind_from_irqhandler(info->tx_irq, info); 1418 unbind_from_irqhandler(info->rx_irq, info); 1419 } 1420 info->tx_evtchn = info->rx_evtchn = 0; 1421 info->tx_irq = info->rx_irq = 0; 1422 1423 /* End access and free the pages */ 1424 xennet_end_access(info->tx_ring_ref, info->tx.sring); 1425 xennet_end_access(info->rx_ring_ref, info->rx.sring); 1426 1427 info->tx_ring_ref = GRANT_INVALID_REF; 1428 info->rx_ring_ref = GRANT_INVALID_REF; 1429 info->tx.sring = NULL; 1430 info->rx.sring = NULL; 1431 } 1432 1433 /** 1434 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1435 * driver restart. We tear down our netif structure and recreate it, but 1436 * leave the device-layer structures intact so that this is transparent to the 1437 * rest of the kernel. 1438 */ 1439 static int netfront_resume(struct xenbus_device *dev) 1440 { 1441 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1442 1443 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1444 1445 xennet_disconnect_backend(info); 1446 return 0; 1447 } 1448 1449 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1450 { 1451 char *s, *e, *macstr; 1452 int i; 1453 1454 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1455 if (IS_ERR(macstr)) 1456 return PTR_ERR(macstr); 1457 1458 for (i = 0; i < ETH_ALEN; i++) { 1459 mac[i] = simple_strtoul(s, &e, 16); 1460 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1461 kfree(macstr); 1462 return -ENOENT; 1463 } 1464 s = e+1; 1465 } 1466 1467 kfree(macstr); 1468 return 0; 1469 } 1470 1471 static int setup_netfront_single(struct netfront_info *info) 1472 { 1473 int err; 1474 1475 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); 1476 if (err < 0) 1477 goto fail; 1478 1479 err = bind_evtchn_to_irqhandler(info->tx_evtchn, 1480 xennet_interrupt, 1481 0, info->netdev->name, info); 1482 if (err < 0) 1483 goto bind_fail; 1484 info->rx_evtchn = info->tx_evtchn; 1485 info->rx_irq = info->tx_irq = err; 1486 1487 return 0; 1488 1489 bind_fail: 1490 xenbus_free_evtchn(info->xbdev, info->tx_evtchn); 1491 info->tx_evtchn = 0; 1492 fail: 1493 return err; 1494 } 1495 1496 static int setup_netfront_split(struct netfront_info *info) 1497 { 1498 int err; 1499 1500 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); 1501 if (err < 0) 1502 goto fail; 1503 err = xenbus_alloc_evtchn(info->xbdev, &info->rx_evtchn); 1504 if (err < 0) 1505 goto alloc_rx_evtchn_fail; 1506 1507 snprintf(info->tx_irq_name, sizeof(info->tx_irq_name), 1508 "%s-tx", info->netdev->name); 1509 err = bind_evtchn_to_irqhandler(info->tx_evtchn, 1510 xennet_tx_interrupt, 1511 0, info->tx_irq_name, info); 1512 if (err < 0) 1513 goto bind_tx_fail; 1514 info->tx_irq = err; 1515 1516 snprintf(info->rx_irq_name, sizeof(info->rx_irq_name), 1517 "%s-rx", info->netdev->name); 1518 err = bind_evtchn_to_irqhandler(info->rx_evtchn, 1519 xennet_rx_interrupt, 1520 0, info->rx_irq_name, info); 1521 if (err < 0) 1522 goto bind_rx_fail; 1523 info->rx_irq = err; 1524 1525 return 0; 1526 1527 bind_rx_fail: 1528 unbind_from_irqhandler(info->tx_irq, info); 1529 info->tx_irq = 0; 1530 bind_tx_fail: 1531 xenbus_free_evtchn(info->xbdev, info->rx_evtchn); 1532 info->rx_evtchn = 0; 1533 alloc_rx_evtchn_fail: 1534 xenbus_free_evtchn(info->xbdev, info->tx_evtchn); 1535 info->tx_evtchn = 0; 1536 fail: 1537 return err; 1538 } 1539 1540 static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) 1541 { 1542 struct xen_netif_tx_sring *txs; 1543 struct xen_netif_rx_sring *rxs; 1544 int err; 1545 struct net_device *netdev = info->netdev; 1546 unsigned int feature_split_evtchn; 1547 1548 info->tx_ring_ref = GRANT_INVALID_REF; 1549 info->rx_ring_ref = GRANT_INVALID_REF; 1550 info->rx.sring = NULL; 1551 info->tx.sring = NULL; 1552 netdev->irq = 0; 1553 1554 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1555 "feature-split-event-channels", "%u", 1556 &feature_split_evtchn); 1557 if (err < 0) 1558 feature_split_evtchn = 0; 1559 1560 err = xen_net_read_mac(dev, netdev->dev_addr); 1561 if (err) { 1562 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1563 goto fail; 1564 } 1565 1566 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1567 if (!txs) { 1568 err = -ENOMEM; 1569 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1570 goto fail; 1571 } 1572 SHARED_RING_INIT(txs); 1573 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE); 1574 1575 err = xenbus_grant_ring(dev, virt_to_mfn(txs)); 1576 if (err < 0) 1577 goto grant_tx_ring_fail; 1578 1579 info->tx_ring_ref = err; 1580 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1581 if (!rxs) { 1582 err = -ENOMEM; 1583 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1584 goto alloc_rx_ring_fail; 1585 } 1586 SHARED_RING_INIT(rxs); 1587 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE); 1588 1589 err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); 1590 if (err < 0) 1591 goto grant_rx_ring_fail; 1592 info->rx_ring_ref = err; 1593 1594 if (feature_split_evtchn) 1595 err = setup_netfront_split(info); 1596 /* setup single event channel if 1597 * a) feature-split-event-channels == 0 1598 * b) feature-split-event-channels == 1 but failed to setup 1599 */ 1600 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1601 err = setup_netfront_single(info); 1602 1603 if (err) 1604 goto alloc_evtchn_fail; 1605 1606 return 0; 1607 1608 /* If we fail to setup netfront, it is safe to just revoke access to 1609 * granted pages because backend is not accessing it at this point. 1610 */ 1611 alloc_evtchn_fail: 1612 gnttab_end_foreign_access_ref(info->rx_ring_ref, 0); 1613 grant_rx_ring_fail: 1614 free_page((unsigned long)rxs); 1615 alloc_rx_ring_fail: 1616 gnttab_end_foreign_access_ref(info->tx_ring_ref, 0); 1617 grant_tx_ring_fail: 1618 free_page((unsigned long)txs); 1619 fail: 1620 return err; 1621 } 1622 1623 /* Common code used when first setting up, and when resuming. */ 1624 static int talk_to_netback(struct xenbus_device *dev, 1625 struct netfront_info *info) 1626 { 1627 const char *message; 1628 struct xenbus_transaction xbt; 1629 int err; 1630 1631 /* Create shared ring, alloc event channel. */ 1632 err = setup_netfront(dev, info); 1633 if (err) 1634 goto out; 1635 1636 again: 1637 err = xenbus_transaction_start(&xbt); 1638 if (err) { 1639 xenbus_dev_fatal(dev, err, "starting transaction"); 1640 goto destroy_ring; 1641 } 1642 1643 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u", 1644 info->tx_ring_ref); 1645 if (err) { 1646 message = "writing tx ring-ref"; 1647 goto abort_transaction; 1648 } 1649 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u", 1650 info->rx_ring_ref); 1651 if (err) { 1652 message = "writing rx ring-ref"; 1653 goto abort_transaction; 1654 } 1655 1656 if (info->tx_evtchn == info->rx_evtchn) { 1657 err = xenbus_printf(xbt, dev->nodename, 1658 "event-channel", "%u", info->tx_evtchn); 1659 if (err) { 1660 message = "writing event-channel"; 1661 goto abort_transaction; 1662 } 1663 } else { 1664 err = xenbus_printf(xbt, dev->nodename, 1665 "event-channel-tx", "%u", info->tx_evtchn); 1666 if (err) { 1667 message = "writing event-channel-tx"; 1668 goto abort_transaction; 1669 } 1670 err = xenbus_printf(xbt, dev->nodename, 1671 "event-channel-rx", "%u", info->rx_evtchn); 1672 if (err) { 1673 message = "writing event-channel-rx"; 1674 goto abort_transaction; 1675 } 1676 } 1677 1678 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1679 1); 1680 if (err) { 1681 message = "writing request-rx-copy"; 1682 goto abort_transaction; 1683 } 1684 1685 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1686 if (err) { 1687 message = "writing feature-rx-notify"; 1688 goto abort_transaction; 1689 } 1690 1691 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1692 if (err) { 1693 message = "writing feature-sg"; 1694 goto abort_transaction; 1695 } 1696 1697 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1698 if (err) { 1699 message = "writing feature-gso-tcpv4"; 1700 goto abort_transaction; 1701 } 1702 1703 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1704 if (err) { 1705 message = "writing feature-gso-tcpv6"; 1706 goto abort_transaction; 1707 } 1708 1709 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1710 "1"); 1711 if (err) { 1712 message = "writing feature-ipv6-csum-offload"; 1713 goto abort_transaction; 1714 } 1715 1716 err = xenbus_transaction_end(xbt, 0); 1717 if (err) { 1718 if (err == -EAGAIN) 1719 goto again; 1720 xenbus_dev_fatal(dev, err, "completing transaction"); 1721 goto destroy_ring; 1722 } 1723 1724 return 0; 1725 1726 abort_transaction: 1727 xenbus_transaction_end(xbt, 1); 1728 xenbus_dev_fatal(dev, err, "%s", message); 1729 destroy_ring: 1730 xennet_disconnect_backend(info); 1731 out: 1732 return err; 1733 } 1734 1735 static int xennet_connect(struct net_device *dev) 1736 { 1737 struct netfront_info *np = netdev_priv(dev); 1738 int i, requeue_idx, err; 1739 struct sk_buff *skb; 1740 grant_ref_t ref; 1741 struct xen_netif_rx_request *req; 1742 unsigned int feature_rx_copy; 1743 1744 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1745 "feature-rx-copy", "%u", &feature_rx_copy); 1746 if (err != 1) 1747 feature_rx_copy = 0; 1748 1749 if (!feature_rx_copy) { 1750 dev_info(&dev->dev, 1751 "backend does not support copying receive path\n"); 1752 return -ENODEV; 1753 } 1754 1755 err = talk_to_netback(np->xbdev, np); 1756 if (err) 1757 return err; 1758 1759 rtnl_lock(); 1760 netdev_update_features(dev); 1761 rtnl_unlock(); 1762 1763 spin_lock_bh(&np->rx_lock); 1764 spin_lock_irq(&np->tx_lock); 1765 1766 /* Step 1: Discard all pending TX packet fragments. */ 1767 xennet_release_tx_bufs(np); 1768 1769 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ 1770 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { 1771 skb_frag_t *frag; 1772 const struct page *page; 1773 if (!np->rx_skbs[i]) 1774 continue; 1775 1776 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i); 1777 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i); 1778 req = RING_GET_REQUEST(&np->rx, requeue_idx); 1779 1780 frag = &skb_shinfo(skb)->frags[0]; 1781 page = skb_frag_page(frag); 1782 gnttab_grant_foreign_access_ref( 1783 ref, np->xbdev->otherend_id, 1784 pfn_to_mfn(page_to_pfn(page)), 1785 0); 1786 req->gref = ref; 1787 req->id = requeue_idx; 1788 1789 requeue_idx++; 1790 } 1791 1792 np->rx.req_prod_pvt = requeue_idx; 1793 1794 /* 1795 * Step 3: All public and private state should now be sane. Get 1796 * ready to start sending and receiving packets and give the driver 1797 * domain a kick because we've probably just requeued some 1798 * packets. 1799 */ 1800 netif_carrier_on(np->netdev); 1801 notify_remote_via_irq(np->tx_irq); 1802 if (np->tx_irq != np->rx_irq) 1803 notify_remote_via_irq(np->rx_irq); 1804 xennet_tx_buf_gc(dev); 1805 xennet_alloc_rx_buffers(dev); 1806 1807 spin_unlock_irq(&np->tx_lock); 1808 spin_unlock_bh(&np->rx_lock); 1809 1810 return 0; 1811 } 1812 1813 /** 1814 * Callback received when the backend's state changes. 1815 */ 1816 static void netback_changed(struct xenbus_device *dev, 1817 enum xenbus_state backend_state) 1818 { 1819 struct netfront_info *np = dev_get_drvdata(&dev->dev); 1820 struct net_device *netdev = np->netdev; 1821 1822 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 1823 1824 switch (backend_state) { 1825 case XenbusStateInitialising: 1826 case XenbusStateInitialised: 1827 case XenbusStateReconfiguring: 1828 case XenbusStateReconfigured: 1829 case XenbusStateUnknown: 1830 break; 1831 1832 case XenbusStateInitWait: 1833 if (dev->state != XenbusStateInitialising) 1834 break; 1835 if (xennet_connect(netdev) != 0) 1836 break; 1837 xenbus_switch_state(dev, XenbusStateConnected); 1838 break; 1839 1840 case XenbusStateConnected: 1841 netdev_notify_peers(netdev); 1842 break; 1843 1844 case XenbusStateClosed: 1845 if (dev->state == XenbusStateClosed) 1846 break; 1847 /* Missed the backend's CLOSING state -- fallthrough */ 1848 case XenbusStateClosing: 1849 xenbus_frontend_closed(dev); 1850 break; 1851 } 1852 } 1853 1854 static const struct xennet_stat { 1855 char name[ETH_GSTRING_LEN]; 1856 u16 offset; 1857 } xennet_stats[] = { 1858 { 1859 "rx_gso_checksum_fixup", 1860 offsetof(struct netfront_info, rx_gso_checksum_fixup) 1861 }, 1862 }; 1863 1864 static int xennet_get_sset_count(struct net_device *dev, int string_set) 1865 { 1866 switch (string_set) { 1867 case ETH_SS_STATS: 1868 return ARRAY_SIZE(xennet_stats); 1869 default: 1870 return -EINVAL; 1871 } 1872 } 1873 1874 static void xennet_get_ethtool_stats(struct net_device *dev, 1875 struct ethtool_stats *stats, u64 * data) 1876 { 1877 void *np = netdev_priv(dev); 1878 int i; 1879 1880 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 1881 data[i] = *(unsigned long *)(np + xennet_stats[i].offset); 1882 } 1883 1884 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 1885 { 1886 int i; 1887 1888 switch (stringset) { 1889 case ETH_SS_STATS: 1890 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 1891 memcpy(data + i * ETH_GSTRING_LEN, 1892 xennet_stats[i].name, ETH_GSTRING_LEN); 1893 break; 1894 } 1895 } 1896 1897 static const struct ethtool_ops xennet_ethtool_ops = 1898 { 1899 .get_link = ethtool_op_get_link, 1900 1901 .get_sset_count = xennet_get_sset_count, 1902 .get_ethtool_stats = xennet_get_ethtool_stats, 1903 .get_strings = xennet_get_strings, 1904 }; 1905 1906 #ifdef CONFIG_SYSFS 1907 static ssize_t show_rxbuf_min(struct device *dev, 1908 struct device_attribute *attr, char *buf) 1909 { 1910 struct net_device *netdev = to_net_dev(dev); 1911 struct netfront_info *info = netdev_priv(netdev); 1912 1913 return sprintf(buf, "%u\n", info->rx_min_target); 1914 } 1915 1916 static ssize_t store_rxbuf_min(struct device *dev, 1917 struct device_attribute *attr, 1918 const char *buf, size_t len) 1919 { 1920 struct net_device *netdev = to_net_dev(dev); 1921 struct netfront_info *np = netdev_priv(netdev); 1922 char *endp; 1923 unsigned long target; 1924 1925 if (!capable(CAP_NET_ADMIN)) 1926 return -EPERM; 1927 1928 target = simple_strtoul(buf, &endp, 0); 1929 if (endp == buf) 1930 return -EBADMSG; 1931 1932 if (target < RX_MIN_TARGET) 1933 target = RX_MIN_TARGET; 1934 if (target > RX_MAX_TARGET) 1935 target = RX_MAX_TARGET; 1936 1937 spin_lock_bh(&np->rx_lock); 1938 if (target > np->rx_max_target) 1939 np->rx_max_target = target; 1940 np->rx_min_target = target; 1941 if (target > np->rx_target) 1942 np->rx_target = target; 1943 1944 xennet_alloc_rx_buffers(netdev); 1945 1946 spin_unlock_bh(&np->rx_lock); 1947 return len; 1948 } 1949 1950 static ssize_t show_rxbuf_max(struct device *dev, 1951 struct device_attribute *attr, char *buf) 1952 { 1953 struct net_device *netdev = to_net_dev(dev); 1954 struct netfront_info *info = netdev_priv(netdev); 1955 1956 return sprintf(buf, "%u\n", info->rx_max_target); 1957 } 1958 1959 static ssize_t store_rxbuf_max(struct device *dev, 1960 struct device_attribute *attr, 1961 const char *buf, size_t len) 1962 { 1963 struct net_device *netdev = to_net_dev(dev); 1964 struct netfront_info *np = netdev_priv(netdev); 1965 char *endp; 1966 unsigned long target; 1967 1968 if (!capable(CAP_NET_ADMIN)) 1969 return -EPERM; 1970 1971 target = simple_strtoul(buf, &endp, 0); 1972 if (endp == buf) 1973 return -EBADMSG; 1974 1975 if (target < RX_MIN_TARGET) 1976 target = RX_MIN_TARGET; 1977 if (target > RX_MAX_TARGET) 1978 target = RX_MAX_TARGET; 1979 1980 spin_lock_bh(&np->rx_lock); 1981 if (target < np->rx_min_target) 1982 np->rx_min_target = target; 1983 np->rx_max_target = target; 1984 if (target < np->rx_target) 1985 np->rx_target = target; 1986 1987 xennet_alloc_rx_buffers(netdev); 1988 1989 spin_unlock_bh(&np->rx_lock); 1990 return len; 1991 } 1992 1993 static ssize_t show_rxbuf_cur(struct device *dev, 1994 struct device_attribute *attr, char *buf) 1995 { 1996 struct net_device *netdev = to_net_dev(dev); 1997 struct netfront_info *info = netdev_priv(netdev); 1998 1999 return sprintf(buf, "%u\n", info->rx_target); 2000 } 2001 2002 static struct device_attribute xennet_attrs[] = { 2003 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), 2004 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), 2005 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), 2006 }; 2007 2008 static int xennet_sysfs_addif(struct net_device *netdev) 2009 { 2010 int i; 2011 int err; 2012 2013 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { 2014 err = device_create_file(&netdev->dev, 2015 &xennet_attrs[i]); 2016 if (err) 2017 goto fail; 2018 } 2019 return 0; 2020 2021 fail: 2022 while (--i >= 0) 2023 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2024 return err; 2025 } 2026 2027 static void xennet_sysfs_delif(struct net_device *netdev) 2028 { 2029 int i; 2030 2031 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) 2032 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2033 } 2034 2035 #endif /* CONFIG_SYSFS */ 2036 2037 static const struct xenbus_device_id netfront_ids[] = { 2038 { "vif" }, 2039 { "" } 2040 }; 2041 2042 2043 static int xennet_remove(struct xenbus_device *dev) 2044 { 2045 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2046 2047 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2048 2049 xennet_disconnect_backend(info); 2050 2051 xennet_sysfs_delif(info->netdev); 2052 2053 unregister_netdev(info->netdev); 2054 2055 del_timer_sync(&info->rx_refill_timer); 2056 2057 free_percpu(info->stats); 2058 2059 free_netdev(info->netdev); 2060 2061 return 0; 2062 } 2063 2064 static DEFINE_XENBUS_DRIVER(netfront, , 2065 .probe = netfront_probe, 2066 .remove = xennet_remove, 2067 .resume = netfront_resume, 2068 .otherend_changed = netback_changed, 2069 ); 2070 2071 static int __init netif_init(void) 2072 { 2073 if (!xen_domain()) 2074 return -ENODEV; 2075 2076 if (!xen_has_pv_nic_devices()) 2077 return -ENODEV; 2078 2079 pr_info("Initialising Xen virtual ethernet driver\n"); 2080 2081 return xenbus_register_frontend(&netfront_driver); 2082 } 2083 module_init(netif_init); 2084 2085 2086 static void __exit netif_exit(void) 2087 { 2088 xenbus_unregister_driver(&netfront_driver); 2089 } 2090 module_exit(netif_exit); 2091 2092 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2093 MODULE_LICENSE("GPL"); 2094 MODULE_ALIAS("xen:vif"); 2095 MODULE_ALIAS("xennet"); 2096