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 <xen/xen.h> 49 #include <xen/xenbus.h> 50 #include <xen/events.h> 51 #include <xen/page.h> 52 #include <xen/platform_pci.h> 53 #include <xen/grant_table.h> 54 55 #include <xen/interface/io/netif.h> 56 #include <xen/interface/memory.h> 57 #include <xen/interface/grant_table.h> 58 59 /* Module parameters */ 60 #define MAX_QUEUES_DEFAULT 8 61 static unsigned int xennet_max_queues; 62 module_param_named(max_queues, xennet_max_queues, uint, 0644); 63 MODULE_PARM_DESC(max_queues, 64 "Maximum number of queues per virtual interface"); 65 66 static const struct ethtool_ops xennet_ethtool_ops; 67 68 struct netfront_cb { 69 int pull_to; 70 }; 71 72 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 73 74 #define RX_COPY_THRESHOLD 256 75 76 #define GRANT_INVALID_REF 0 77 78 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE) 79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE) 80 81 /* Minimum number of Rx slots (includes slot for GSO metadata). */ 82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1) 83 84 /* Queue name is interface name with "-qNNN" appended */ 85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6) 86 87 /* IRQ name is queue name with "-tx" or "-rx" appended */ 88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) 89 90 static DECLARE_WAIT_QUEUE_HEAD(module_unload_q); 91 92 struct netfront_stats { 93 u64 packets; 94 u64 bytes; 95 struct u64_stats_sync syncp; 96 }; 97 98 struct netfront_info; 99 100 struct netfront_queue { 101 unsigned int id; /* Queue ID, 0-based */ 102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ 103 struct netfront_info *info; 104 105 struct napi_struct napi; 106 107 /* Split event channels support, tx_* == rx_* when using 108 * single event channel. 109 */ 110 unsigned int tx_evtchn, rx_evtchn; 111 unsigned int tx_irq, rx_irq; 112 /* Only used when split event channels support is enabled */ 113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ 114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ 115 116 spinlock_t tx_lock; 117 struct xen_netif_tx_front_ring tx; 118 int tx_ring_ref; 119 120 /* 121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 122 * are linked from tx_skb_freelist through skb_entry.link. 123 * 124 * NB. Freelist index entries are always going to be less than 125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 126 * greater than PAGE_OFFSET: we use this property to distinguish 127 * them. 128 */ 129 union skb_entry { 130 struct sk_buff *skb; 131 unsigned long link; 132 } tx_skbs[NET_TX_RING_SIZE]; 133 grant_ref_t gref_tx_head; 134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 135 struct page *grant_tx_page[NET_TX_RING_SIZE]; 136 unsigned tx_skb_freelist; 137 138 spinlock_t rx_lock ____cacheline_aligned_in_smp; 139 struct xen_netif_rx_front_ring rx; 140 int rx_ring_ref; 141 142 struct timer_list rx_refill_timer; 143 144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 145 grant_ref_t gref_rx_head; 146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 147 }; 148 149 struct netfront_info { 150 struct list_head list; 151 struct net_device *netdev; 152 153 struct xenbus_device *xbdev; 154 155 /* Multi-queue support */ 156 struct netfront_queue *queues; 157 158 /* Statistics */ 159 struct netfront_stats __percpu *rx_stats; 160 struct netfront_stats __percpu *tx_stats; 161 162 atomic_t rx_gso_checksum_fixup; 163 }; 164 165 struct netfront_rx_info { 166 struct xen_netif_rx_response rx; 167 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 168 }; 169 170 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 171 { 172 list->link = id; 173 } 174 175 static int skb_entry_is_link(const union skb_entry *list) 176 { 177 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 178 return (unsigned long)list->skb < PAGE_OFFSET; 179 } 180 181 /* 182 * Access macros for acquiring freeing slots in tx_skbs[]. 183 */ 184 185 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 186 unsigned short id) 187 { 188 skb_entry_set_link(&list[id], *head); 189 *head = id; 190 } 191 192 static unsigned short get_id_from_freelist(unsigned *head, 193 union skb_entry *list) 194 { 195 unsigned int id = *head; 196 *head = list[id].link; 197 return id; 198 } 199 200 static int xennet_rxidx(RING_IDX idx) 201 { 202 return idx & (NET_RX_RING_SIZE - 1); 203 } 204 205 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, 206 RING_IDX ri) 207 { 208 int i = xennet_rxidx(ri); 209 struct sk_buff *skb = queue->rx_skbs[i]; 210 queue->rx_skbs[i] = NULL; 211 return skb; 212 } 213 214 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, 215 RING_IDX ri) 216 { 217 int i = xennet_rxidx(ri); 218 grant_ref_t ref = queue->grant_rx_ref[i]; 219 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 220 return ref; 221 } 222 223 #ifdef CONFIG_SYSFS 224 static const struct attribute_group xennet_dev_group; 225 #endif 226 227 static bool xennet_can_sg(struct net_device *dev) 228 { 229 return dev->features & NETIF_F_SG; 230 } 231 232 233 static void rx_refill_timeout(struct timer_list *t) 234 { 235 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer); 236 napi_schedule(&queue->napi); 237 } 238 239 static int netfront_tx_slot_available(struct netfront_queue *queue) 240 { 241 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < 242 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2); 243 } 244 245 static void xennet_maybe_wake_tx(struct netfront_queue *queue) 246 { 247 struct net_device *dev = queue->info->netdev; 248 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); 249 250 if (unlikely(netif_tx_queue_stopped(dev_queue)) && 251 netfront_tx_slot_available(queue) && 252 likely(netif_running(dev))) 253 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); 254 } 255 256 257 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue) 258 { 259 struct sk_buff *skb; 260 struct page *page; 261 262 skb = __netdev_alloc_skb(queue->info->netdev, 263 RX_COPY_THRESHOLD + NET_IP_ALIGN, 264 GFP_ATOMIC | __GFP_NOWARN); 265 if (unlikely(!skb)) 266 return NULL; 267 268 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 269 if (!page) { 270 kfree_skb(skb); 271 return NULL; 272 } 273 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 274 275 /* Align ip header to a 16 bytes boundary */ 276 skb_reserve(skb, NET_IP_ALIGN); 277 skb->dev = queue->info->netdev; 278 279 return skb; 280 } 281 282 283 static void xennet_alloc_rx_buffers(struct netfront_queue *queue) 284 { 285 RING_IDX req_prod = queue->rx.req_prod_pvt; 286 int notify; 287 int err = 0; 288 289 if (unlikely(!netif_carrier_ok(queue->info->netdev))) 290 return; 291 292 for (req_prod = queue->rx.req_prod_pvt; 293 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE; 294 req_prod++) { 295 struct sk_buff *skb; 296 unsigned short id; 297 grant_ref_t ref; 298 struct page *page; 299 struct xen_netif_rx_request *req; 300 301 skb = xennet_alloc_one_rx_buffer(queue); 302 if (!skb) { 303 err = -ENOMEM; 304 break; 305 } 306 307 id = xennet_rxidx(req_prod); 308 309 BUG_ON(queue->rx_skbs[id]); 310 queue->rx_skbs[id] = skb; 311 312 ref = gnttab_claim_grant_reference(&queue->gref_rx_head); 313 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 314 queue->grant_rx_ref[id] = ref; 315 316 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 317 318 req = RING_GET_REQUEST(&queue->rx, req_prod); 319 gnttab_page_grant_foreign_access_ref_one(ref, 320 queue->info->xbdev->otherend_id, 321 page, 322 0); 323 req->id = id; 324 req->gref = ref; 325 } 326 327 queue->rx.req_prod_pvt = req_prod; 328 329 /* Try again later if there are not enough requests or skb allocation 330 * failed. 331 * Enough requests is quantified as the sum of newly created slots and 332 * the unconsumed slots at the backend. 333 */ 334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN || 335 unlikely(err)) { 336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); 337 return; 338 } 339 340 wmb(); /* barrier so backend seens requests */ 341 342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 343 if (notify) 344 notify_remote_via_irq(queue->rx_irq); 345 } 346 347 static int xennet_open(struct net_device *dev) 348 { 349 struct netfront_info *np = netdev_priv(dev); 350 unsigned int num_queues = dev->real_num_tx_queues; 351 unsigned int i = 0; 352 struct netfront_queue *queue = NULL; 353 354 for (i = 0; i < num_queues; ++i) { 355 queue = &np->queues[i]; 356 napi_enable(&queue->napi); 357 358 spin_lock_bh(&queue->rx_lock); 359 if (netif_carrier_ok(dev)) { 360 xennet_alloc_rx_buffers(queue); 361 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 362 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 363 napi_schedule(&queue->napi); 364 } 365 spin_unlock_bh(&queue->rx_lock); 366 } 367 368 netif_tx_start_all_queues(dev); 369 370 return 0; 371 } 372 373 static void xennet_tx_buf_gc(struct netfront_queue *queue) 374 { 375 RING_IDX cons, prod; 376 unsigned short id; 377 struct sk_buff *skb; 378 bool more_to_do; 379 380 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 381 382 do { 383 prod = queue->tx.sring->rsp_prod; 384 rmb(); /* Ensure we see responses up to 'rp'. */ 385 386 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 387 struct xen_netif_tx_response *txrsp; 388 389 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 390 if (txrsp->status == XEN_NETIF_RSP_NULL) 391 continue; 392 393 id = txrsp->id; 394 skb = queue->tx_skbs[id].skb; 395 if (unlikely(gnttab_query_foreign_access( 396 queue->grant_tx_ref[id]) != 0)) { 397 pr_alert("%s: warning -- grant still in use by backend domain\n", 398 __func__); 399 BUG(); 400 } 401 gnttab_end_foreign_access_ref( 402 queue->grant_tx_ref[id], GNTMAP_readonly); 403 gnttab_release_grant_reference( 404 &queue->gref_tx_head, queue->grant_tx_ref[id]); 405 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 406 queue->grant_tx_page[id] = NULL; 407 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 408 dev_kfree_skb_irq(skb); 409 } 410 411 queue->tx.rsp_cons = prod; 412 413 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); 414 } while (more_to_do); 415 416 xennet_maybe_wake_tx(queue); 417 } 418 419 struct xennet_gnttab_make_txreq { 420 struct netfront_queue *queue; 421 struct sk_buff *skb; 422 struct page *page; 423 struct xen_netif_tx_request *tx; /* Last request */ 424 unsigned int size; 425 }; 426 427 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, 428 unsigned int len, void *data) 429 { 430 struct xennet_gnttab_make_txreq *info = data; 431 unsigned int id; 432 struct xen_netif_tx_request *tx; 433 grant_ref_t ref; 434 /* convenient aliases */ 435 struct page *page = info->page; 436 struct netfront_queue *queue = info->queue; 437 struct sk_buff *skb = info->skb; 438 439 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 440 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 441 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 442 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 443 444 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 445 gfn, GNTMAP_readonly); 446 447 queue->tx_skbs[id].skb = skb; 448 queue->grant_tx_page[id] = page; 449 queue->grant_tx_ref[id] = ref; 450 451 tx->id = id; 452 tx->gref = ref; 453 tx->offset = offset; 454 tx->size = len; 455 tx->flags = 0; 456 457 info->tx = tx; 458 info->size += tx->size; 459 } 460 461 static struct xen_netif_tx_request *xennet_make_first_txreq( 462 struct netfront_queue *queue, struct sk_buff *skb, 463 struct page *page, unsigned int offset, unsigned int len) 464 { 465 struct xennet_gnttab_make_txreq info = { 466 .queue = queue, 467 .skb = skb, 468 .page = page, 469 .size = 0, 470 }; 471 472 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info); 473 474 return info.tx; 475 } 476 477 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, 478 unsigned int len, void *data) 479 { 480 struct xennet_gnttab_make_txreq *info = data; 481 482 info->tx->flags |= XEN_NETTXF_more_data; 483 skb_get(info->skb); 484 xennet_tx_setup_grant(gfn, offset, len, data); 485 } 486 487 static struct xen_netif_tx_request *xennet_make_txreqs( 488 struct netfront_queue *queue, struct xen_netif_tx_request *tx, 489 struct sk_buff *skb, struct page *page, 490 unsigned int offset, unsigned int len) 491 { 492 struct xennet_gnttab_make_txreq info = { 493 .queue = queue, 494 .skb = skb, 495 .tx = tx, 496 }; 497 498 /* Skip unused frames from start of page */ 499 page += offset >> PAGE_SHIFT; 500 offset &= ~PAGE_MASK; 501 502 while (len) { 503 info.page = page; 504 info.size = 0; 505 506 gnttab_foreach_grant_in_range(page, offset, len, 507 xennet_make_one_txreq, 508 &info); 509 510 page++; 511 offset = 0; 512 len -= info.size; 513 } 514 515 return info.tx; 516 } 517 518 /* 519 * Count how many ring slots are required to send this skb. Each frag 520 * might be a compound page. 521 */ 522 static int xennet_count_skb_slots(struct sk_buff *skb) 523 { 524 int i, frags = skb_shinfo(skb)->nr_frags; 525 int slots; 526 527 slots = gnttab_count_grant(offset_in_page(skb->data), 528 skb_headlen(skb)); 529 530 for (i = 0; i < frags; i++) { 531 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 532 unsigned long size = skb_frag_size(frag); 533 unsigned long offset = frag->page_offset; 534 535 /* Skip unused frames from start of page */ 536 offset &= ~PAGE_MASK; 537 538 slots += gnttab_count_grant(offset, size); 539 } 540 541 return slots; 542 } 543 544 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 545 void *accel_priv, select_queue_fallback_t fallback) 546 { 547 unsigned int num_queues = dev->real_num_tx_queues; 548 u32 hash; 549 u16 queue_idx; 550 551 /* First, check if there is only one queue */ 552 if (num_queues == 1) { 553 queue_idx = 0; 554 } else { 555 hash = skb_get_hash(skb); 556 queue_idx = hash % num_queues; 557 } 558 559 return queue_idx; 560 } 561 562 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) 563 564 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 565 { 566 struct netfront_info *np = netdev_priv(dev); 567 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 568 struct xen_netif_tx_request *tx, *first_tx; 569 unsigned int i; 570 int notify; 571 int slots; 572 struct page *page; 573 unsigned int offset; 574 unsigned int len; 575 unsigned long flags; 576 struct netfront_queue *queue = NULL; 577 unsigned int num_queues = dev->real_num_tx_queues; 578 u16 queue_index; 579 struct sk_buff *nskb; 580 581 /* Drop the packet if no queues are set up */ 582 if (num_queues < 1) 583 goto drop; 584 /* Determine which queue to transmit this SKB on */ 585 queue_index = skb_get_queue_mapping(skb); 586 queue = &np->queues[queue_index]; 587 588 /* If skb->len is too big for wire format, drop skb and alert 589 * user about misconfiguration. 590 */ 591 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 592 net_alert_ratelimited( 593 "xennet: skb->len = %u, too big for wire format\n", 594 skb->len); 595 goto drop; 596 } 597 598 slots = xennet_count_skb_slots(skb); 599 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { 600 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 601 slots, skb->len); 602 if (skb_linearize(skb)) 603 goto drop; 604 } 605 606 page = virt_to_page(skb->data); 607 offset = offset_in_page(skb->data); 608 609 /* The first req should be at least ETH_HLEN size or the packet will be 610 * dropped by netback. 611 */ 612 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { 613 nskb = skb_copy(skb, GFP_ATOMIC); 614 if (!nskb) 615 goto drop; 616 dev_consume_skb_any(skb); 617 skb = nskb; 618 page = virt_to_page(skb->data); 619 offset = offset_in_page(skb->data); 620 } 621 622 len = skb_headlen(skb); 623 624 spin_lock_irqsave(&queue->tx_lock, flags); 625 626 if (unlikely(!netif_carrier_ok(dev) || 627 (slots > 1 && !xennet_can_sg(dev)) || 628 netif_needs_gso(skb, netif_skb_features(skb)))) { 629 spin_unlock_irqrestore(&queue->tx_lock, flags); 630 goto drop; 631 } 632 633 /* First request for the linear area. */ 634 first_tx = tx = xennet_make_first_txreq(queue, skb, 635 page, offset, len); 636 offset += tx->size; 637 if (offset == PAGE_SIZE) { 638 page++; 639 offset = 0; 640 } 641 len -= tx->size; 642 643 if (skb->ip_summed == CHECKSUM_PARTIAL) 644 /* local packet? */ 645 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 646 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 647 /* remote but checksummed. */ 648 tx->flags |= XEN_NETTXF_data_validated; 649 650 /* Optional extra info after the first request. */ 651 if (skb_shinfo(skb)->gso_size) { 652 struct xen_netif_extra_info *gso; 653 654 gso = (struct xen_netif_extra_info *) 655 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 656 657 tx->flags |= XEN_NETTXF_extra_info; 658 659 gso->u.gso.size = skb_shinfo(skb)->gso_size; 660 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 661 XEN_NETIF_GSO_TYPE_TCPV6 : 662 XEN_NETIF_GSO_TYPE_TCPV4; 663 gso->u.gso.pad = 0; 664 gso->u.gso.features = 0; 665 666 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 667 gso->flags = 0; 668 } 669 670 /* Requests for the rest of the linear area. */ 671 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); 672 673 /* Requests for all the frags. */ 674 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 675 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 676 tx = xennet_make_txreqs(queue, tx, skb, 677 skb_frag_page(frag), frag->page_offset, 678 skb_frag_size(frag)); 679 } 680 681 /* First request has the packet length. */ 682 first_tx->size = skb->len; 683 684 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 685 if (notify) 686 notify_remote_via_irq(queue->tx_irq); 687 688 u64_stats_update_begin(&tx_stats->syncp); 689 tx_stats->bytes += skb->len; 690 tx_stats->packets++; 691 u64_stats_update_end(&tx_stats->syncp); 692 693 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 694 xennet_tx_buf_gc(queue); 695 696 if (!netfront_tx_slot_available(queue)) 697 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 698 699 spin_unlock_irqrestore(&queue->tx_lock, flags); 700 701 return NETDEV_TX_OK; 702 703 drop: 704 dev->stats.tx_dropped++; 705 dev_kfree_skb_any(skb); 706 return NETDEV_TX_OK; 707 } 708 709 static int xennet_close(struct net_device *dev) 710 { 711 struct netfront_info *np = netdev_priv(dev); 712 unsigned int num_queues = dev->real_num_tx_queues; 713 unsigned int i; 714 struct netfront_queue *queue; 715 netif_tx_stop_all_queues(np->netdev); 716 for (i = 0; i < num_queues; ++i) { 717 queue = &np->queues[i]; 718 napi_disable(&queue->napi); 719 } 720 return 0; 721 } 722 723 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 724 grant_ref_t ref) 725 { 726 int new = xennet_rxidx(queue->rx.req_prod_pvt); 727 728 BUG_ON(queue->rx_skbs[new]); 729 queue->rx_skbs[new] = skb; 730 queue->grant_rx_ref[new] = ref; 731 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 732 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 733 queue->rx.req_prod_pvt++; 734 } 735 736 static int xennet_get_extras(struct netfront_queue *queue, 737 struct xen_netif_extra_info *extras, 738 RING_IDX rp) 739 740 { 741 struct xen_netif_extra_info *extra; 742 struct device *dev = &queue->info->netdev->dev; 743 RING_IDX cons = queue->rx.rsp_cons; 744 int err = 0; 745 746 do { 747 struct sk_buff *skb; 748 grant_ref_t ref; 749 750 if (unlikely(cons + 1 == rp)) { 751 if (net_ratelimit()) 752 dev_warn(dev, "Missing extra info\n"); 753 err = -EBADR; 754 break; 755 } 756 757 extra = (struct xen_netif_extra_info *) 758 RING_GET_RESPONSE(&queue->rx, ++cons); 759 760 if (unlikely(!extra->type || 761 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 762 if (net_ratelimit()) 763 dev_warn(dev, "Invalid extra type: %d\n", 764 extra->type); 765 err = -EINVAL; 766 } else { 767 memcpy(&extras[extra->type - 1], extra, 768 sizeof(*extra)); 769 } 770 771 skb = xennet_get_rx_skb(queue, cons); 772 ref = xennet_get_rx_ref(queue, cons); 773 xennet_move_rx_slot(queue, skb, ref); 774 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 775 776 queue->rx.rsp_cons = cons; 777 return err; 778 } 779 780 static int xennet_get_responses(struct netfront_queue *queue, 781 struct netfront_rx_info *rinfo, RING_IDX rp, 782 struct sk_buff_head *list) 783 { 784 struct xen_netif_rx_response *rx = &rinfo->rx; 785 struct xen_netif_extra_info *extras = rinfo->extras; 786 struct device *dev = &queue->info->netdev->dev; 787 RING_IDX cons = queue->rx.rsp_cons; 788 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 789 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 790 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 791 int slots = 1; 792 int err = 0; 793 unsigned long ret; 794 795 if (rx->flags & XEN_NETRXF_extra_info) { 796 err = xennet_get_extras(queue, extras, rp); 797 cons = queue->rx.rsp_cons; 798 } 799 800 for (;;) { 801 if (unlikely(rx->status < 0 || 802 rx->offset + rx->status > XEN_PAGE_SIZE)) { 803 if (net_ratelimit()) 804 dev_warn(dev, "rx->offset: %u, size: %d\n", 805 rx->offset, rx->status); 806 xennet_move_rx_slot(queue, skb, ref); 807 err = -EINVAL; 808 goto next; 809 } 810 811 /* 812 * This definitely indicates a bug, either in this driver or in 813 * the backend driver. In future this should flag the bad 814 * situation to the system controller to reboot the backend. 815 */ 816 if (ref == GRANT_INVALID_REF) { 817 if (net_ratelimit()) 818 dev_warn(dev, "Bad rx response id %d.\n", 819 rx->id); 820 err = -EINVAL; 821 goto next; 822 } 823 824 ret = gnttab_end_foreign_access_ref(ref, 0); 825 BUG_ON(!ret); 826 827 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 828 829 __skb_queue_tail(list, skb); 830 831 next: 832 if (!(rx->flags & XEN_NETRXF_more_data)) 833 break; 834 835 if (cons + slots == rp) { 836 if (net_ratelimit()) 837 dev_warn(dev, "Need more slots\n"); 838 err = -ENOENT; 839 break; 840 } 841 842 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 843 skb = xennet_get_rx_skb(queue, cons + slots); 844 ref = xennet_get_rx_ref(queue, cons + slots); 845 slots++; 846 } 847 848 if (unlikely(slots > max)) { 849 if (net_ratelimit()) 850 dev_warn(dev, "Too many slots\n"); 851 err = -E2BIG; 852 } 853 854 if (unlikely(err)) 855 queue->rx.rsp_cons = cons + slots; 856 857 return err; 858 } 859 860 static int xennet_set_skb_gso(struct sk_buff *skb, 861 struct xen_netif_extra_info *gso) 862 { 863 if (!gso->u.gso.size) { 864 if (net_ratelimit()) 865 pr_warn("GSO size must not be zero\n"); 866 return -EINVAL; 867 } 868 869 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 870 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 871 if (net_ratelimit()) 872 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 873 return -EINVAL; 874 } 875 876 skb_shinfo(skb)->gso_size = gso->u.gso.size; 877 skb_shinfo(skb)->gso_type = 878 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 879 SKB_GSO_TCPV4 : 880 SKB_GSO_TCPV6; 881 882 /* Header must be checked, and gso_segs computed. */ 883 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 884 skb_shinfo(skb)->gso_segs = 0; 885 886 return 0; 887 } 888 889 static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 890 struct sk_buff *skb, 891 struct sk_buff_head *list) 892 { 893 struct skb_shared_info *shinfo = skb_shinfo(skb); 894 RING_IDX cons = queue->rx.rsp_cons; 895 struct sk_buff *nskb; 896 897 while ((nskb = __skb_dequeue(list))) { 898 struct xen_netif_rx_response *rx = 899 RING_GET_RESPONSE(&queue->rx, ++cons); 900 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 901 902 if (shinfo->nr_frags == MAX_SKB_FRAGS) { 903 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 904 905 BUG_ON(pull_to <= skb_headlen(skb)); 906 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 907 } 908 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); 909 910 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), 911 rx->offset, rx->status, PAGE_SIZE); 912 913 skb_shinfo(nskb)->nr_frags = 0; 914 kfree_skb(nskb); 915 } 916 917 return cons; 918 } 919 920 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 921 { 922 bool recalculate_partial_csum = false; 923 924 /* 925 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 926 * peers can fail to set NETRXF_csum_blank when sending a GSO 927 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 928 * recalculate the partial checksum. 929 */ 930 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 931 struct netfront_info *np = netdev_priv(dev); 932 atomic_inc(&np->rx_gso_checksum_fixup); 933 skb->ip_summed = CHECKSUM_PARTIAL; 934 recalculate_partial_csum = true; 935 } 936 937 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 938 if (skb->ip_summed != CHECKSUM_PARTIAL) 939 return 0; 940 941 return skb_checksum_setup(skb, recalculate_partial_csum); 942 } 943 944 static int handle_incoming_queue(struct netfront_queue *queue, 945 struct sk_buff_head *rxq) 946 { 947 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 948 int packets_dropped = 0; 949 struct sk_buff *skb; 950 951 while ((skb = __skb_dequeue(rxq)) != NULL) { 952 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 953 954 if (pull_to > skb_headlen(skb)) 955 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 956 957 /* Ethernet work: Delayed to here as it peeks the header. */ 958 skb->protocol = eth_type_trans(skb, queue->info->netdev); 959 skb_reset_network_header(skb); 960 961 if (checksum_setup(queue->info->netdev, skb)) { 962 kfree_skb(skb); 963 packets_dropped++; 964 queue->info->netdev->stats.rx_errors++; 965 continue; 966 } 967 968 u64_stats_update_begin(&rx_stats->syncp); 969 rx_stats->packets++; 970 rx_stats->bytes += skb->len; 971 u64_stats_update_end(&rx_stats->syncp); 972 973 /* Pass it up. */ 974 napi_gro_receive(&queue->napi, skb); 975 } 976 977 return packets_dropped; 978 } 979 980 static int xennet_poll(struct napi_struct *napi, int budget) 981 { 982 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 983 struct net_device *dev = queue->info->netdev; 984 struct sk_buff *skb; 985 struct netfront_rx_info rinfo; 986 struct xen_netif_rx_response *rx = &rinfo.rx; 987 struct xen_netif_extra_info *extras = rinfo.extras; 988 RING_IDX i, rp; 989 int work_done; 990 struct sk_buff_head rxq; 991 struct sk_buff_head errq; 992 struct sk_buff_head tmpq; 993 int err; 994 995 spin_lock(&queue->rx_lock); 996 997 skb_queue_head_init(&rxq); 998 skb_queue_head_init(&errq); 999 skb_queue_head_init(&tmpq); 1000 1001 rp = queue->rx.sring->rsp_prod; 1002 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1003 1004 i = queue->rx.rsp_cons; 1005 work_done = 0; 1006 while ((i != rp) && (work_done < budget)) { 1007 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 1008 memset(extras, 0, sizeof(rinfo.extras)); 1009 1010 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 1011 1012 if (unlikely(err)) { 1013 err: 1014 while ((skb = __skb_dequeue(&tmpq))) 1015 __skb_queue_tail(&errq, skb); 1016 dev->stats.rx_errors++; 1017 i = queue->rx.rsp_cons; 1018 continue; 1019 } 1020 1021 skb = __skb_dequeue(&tmpq); 1022 1023 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1024 struct xen_netif_extra_info *gso; 1025 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1026 1027 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1028 __skb_queue_head(&tmpq, skb); 1029 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1030 goto err; 1031 } 1032 } 1033 1034 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1035 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1036 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1037 1038 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1039 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1040 skb->data_len = rx->status; 1041 skb->len += rx->status; 1042 1043 i = xennet_fill_frags(queue, skb, &tmpq); 1044 1045 if (rx->flags & XEN_NETRXF_csum_blank) 1046 skb->ip_summed = CHECKSUM_PARTIAL; 1047 else if (rx->flags & XEN_NETRXF_data_validated) 1048 skb->ip_summed = CHECKSUM_UNNECESSARY; 1049 1050 __skb_queue_tail(&rxq, skb); 1051 1052 queue->rx.rsp_cons = ++i; 1053 work_done++; 1054 } 1055 1056 __skb_queue_purge(&errq); 1057 1058 work_done -= handle_incoming_queue(queue, &rxq); 1059 1060 xennet_alloc_rx_buffers(queue); 1061 1062 if (work_done < budget) { 1063 int more_to_do = 0; 1064 1065 napi_complete_done(napi, work_done); 1066 1067 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1068 if (more_to_do) 1069 napi_schedule(napi); 1070 } 1071 1072 spin_unlock(&queue->rx_lock); 1073 1074 return work_done; 1075 } 1076 1077 static int xennet_change_mtu(struct net_device *dev, int mtu) 1078 { 1079 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1080 1081 if (mtu > max) 1082 return -EINVAL; 1083 dev->mtu = mtu; 1084 return 0; 1085 } 1086 1087 static void xennet_get_stats64(struct net_device *dev, 1088 struct rtnl_link_stats64 *tot) 1089 { 1090 struct netfront_info *np = netdev_priv(dev); 1091 int cpu; 1092 1093 for_each_possible_cpu(cpu) { 1094 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1095 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1096 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1097 unsigned int start; 1098 1099 do { 1100 start = u64_stats_fetch_begin_irq(&tx_stats->syncp); 1101 tx_packets = tx_stats->packets; 1102 tx_bytes = tx_stats->bytes; 1103 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); 1104 1105 do { 1106 start = u64_stats_fetch_begin_irq(&rx_stats->syncp); 1107 rx_packets = rx_stats->packets; 1108 rx_bytes = rx_stats->bytes; 1109 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); 1110 1111 tot->rx_packets += rx_packets; 1112 tot->tx_packets += tx_packets; 1113 tot->rx_bytes += rx_bytes; 1114 tot->tx_bytes += tx_bytes; 1115 } 1116 1117 tot->rx_errors = dev->stats.rx_errors; 1118 tot->tx_dropped = dev->stats.tx_dropped; 1119 } 1120 1121 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1122 { 1123 struct sk_buff *skb; 1124 int i; 1125 1126 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1127 /* Skip over entries which are actually freelist references */ 1128 if (skb_entry_is_link(&queue->tx_skbs[i])) 1129 continue; 1130 1131 skb = queue->tx_skbs[i].skb; 1132 get_page(queue->grant_tx_page[i]); 1133 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1134 GNTMAP_readonly, 1135 (unsigned long)page_address(queue->grant_tx_page[i])); 1136 queue->grant_tx_page[i] = NULL; 1137 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1138 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1139 dev_kfree_skb_irq(skb); 1140 } 1141 } 1142 1143 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1144 { 1145 int id, ref; 1146 1147 spin_lock_bh(&queue->rx_lock); 1148 1149 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1150 struct sk_buff *skb; 1151 struct page *page; 1152 1153 skb = queue->rx_skbs[id]; 1154 if (!skb) 1155 continue; 1156 1157 ref = queue->grant_rx_ref[id]; 1158 if (ref == GRANT_INVALID_REF) 1159 continue; 1160 1161 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1162 1163 /* gnttab_end_foreign_access() needs a page ref until 1164 * foreign access is ended (which may be deferred). 1165 */ 1166 get_page(page); 1167 gnttab_end_foreign_access(ref, 0, 1168 (unsigned long)page_address(page)); 1169 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1170 1171 kfree_skb(skb); 1172 } 1173 1174 spin_unlock_bh(&queue->rx_lock); 1175 } 1176 1177 static netdev_features_t xennet_fix_features(struct net_device *dev, 1178 netdev_features_t features) 1179 { 1180 struct netfront_info *np = netdev_priv(dev); 1181 1182 if (features & NETIF_F_SG && 1183 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) 1184 features &= ~NETIF_F_SG; 1185 1186 if (features & NETIF_F_IPV6_CSUM && 1187 !xenbus_read_unsigned(np->xbdev->otherend, 1188 "feature-ipv6-csum-offload", 0)) 1189 features &= ~NETIF_F_IPV6_CSUM; 1190 1191 if (features & NETIF_F_TSO && 1192 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) 1193 features &= ~NETIF_F_TSO; 1194 1195 if (features & NETIF_F_TSO6 && 1196 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) 1197 features &= ~NETIF_F_TSO6; 1198 1199 return features; 1200 } 1201 1202 static int xennet_set_features(struct net_device *dev, 1203 netdev_features_t features) 1204 { 1205 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1206 netdev_info(dev, "Reducing MTU because no SG offload"); 1207 dev->mtu = ETH_DATA_LEN; 1208 } 1209 1210 return 0; 1211 } 1212 1213 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1214 { 1215 struct netfront_queue *queue = dev_id; 1216 unsigned long flags; 1217 1218 spin_lock_irqsave(&queue->tx_lock, flags); 1219 xennet_tx_buf_gc(queue); 1220 spin_unlock_irqrestore(&queue->tx_lock, flags); 1221 1222 return IRQ_HANDLED; 1223 } 1224 1225 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1226 { 1227 struct netfront_queue *queue = dev_id; 1228 struct net_device *dev = queue->info->netdev; 1229 1230 if (likely(netif_carrier_ok(dev) && 1231 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1232 napi_schedule(&queue->napi); 1233 1234 return IRQ_HANDLED; 1235 } 1236 1237 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1238 { 1239 xennet_tx_interrupt(irq, dev_id); 1240 xennet_rx_interrupt(irq, dev_id); 1241 return IRQ_HANDLED; 1242 } 1243 1244 #ifdef CONFIG_NET_POLL_CONTROLLER 1245 static void xennet_poll_controller(struct net_device *dev) 1246 { 1247 /* Poll each queue */ 1248 struct netfront_info *info = netdev_priv(dev); 1249 unsigned int num_queues = dev->real_num_tx_queues; 1250 unsigned int i; 1251 for (i = 0; i < num_queues; ++i) 1252 xennet_interrupt(0, &info->queues[i]); 1253 } 1254 #endif 1255 1256 static const struct net_device_ops xennet_netdev_ops = { 1257 .ndo_open = xennet_open, 1258 .ndo_stop = xennet_close, 1259 .ndo_start_xmit = xennet_start_xmit, 1260 .ndo_change_mtu = xennet_change_mtu, 1261 .ndo_get_stats64 = xennet_get_stats64, 1262 .ndo_set_mac_address = eth_mac_addr, 1263 .ndo_validate_addr = eth_validate_addr, 1264 .ndo_fix_features = xennet_fix_features, 1265 .ndo_set_features = xennet_set_features, 1266 .ndo_select_queue = xennet_select_queue, 1267 #ifdef CONFIG_NET_POLL_CONTROLLER 1268 .ndo_poll_controller = xennet_poll_controller, 1269 #endif 1270 }; 1271 1272 static void xennet_free_netdev(struct net_device *netdev) 1273 { 1274 struct netfront_info *np = netdev_priv(netdev); 1275 1276 free_percpu(np->rx_stats); 1277 free_percpu(np->tx_stats); 1278 free_netdev(netdev); 1279 } 1280 1281 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1282 { 1283 int err; 1284 struct net_device *netdev; 1285 struct netfront_info *np; 1286 1287 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1288 if (!netdev) 1289 return ERR_PTR(-ENOMEM); 1290 1291 np = netdev_priv(netdev); 1292 np->xbdev = dev; 1293 1294 np->queues = NULL; 1295 1296 err = -ENOMEM; 1297 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1298 if (np->rx_stats == NULL) 1299 goto exit; 1300 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1301 if (np->tx_stats == NULL) 1302 goto exit; 1303 1304 netdev->netdev_ops = &xennet_netdev_ops; 1305 1306 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1307 NETIF_F_GSO_ROBUST; 1308 netdev->hw_features = NETIF_F_SG | 1309 NETIF_F_IPV6_CSUM | 1310 NETIF_F_TSO | NETIF_F_TSO6; 1311 1312 /* 1313 * Assume that all hw features are available for now. This set 1314 * will be adjusted by the call to netdev_update_features() in 1315 * xennet_connect() which is the earliest point where we can 1316 * negotiate with the backend regarding supported features. 1317 */ 1318 netdev->features |= netdev->hw_features; 1319 1320 netdev->ethtool_ops = &xennet_ethtool_ops; 1321 netdev->min_mtu = ETH_MIN_MTU; 1322 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; 1323 SET_NETDEV_DEV(netdev, &dev->dev); 1324 1325 np->netdev = netdev; 1326 1327 netif_carrier_off(netdev); 1328 1329 xenbus_switch_state(dev, XenbusStateInitialising); 1330 return netdev; 1331 1332 exit: 1333 xennet_free_netdev(netdev); 1334 return ERR_PTR(err); 1335 } 1336 1337 /** 1338 * Entry point to this code when a new device is created. Allocate the basic 1339 * structures and the ring buffers for communication with the backend, and 1340 * inform the backend of the appropriate details for those. 1341 */ 1342 static int netfront_probe(struct xenbus_device *dev, 1343 const struct xenbus_device_id *id) 1344 { 1345 int err; 1346 struct net_device *netdev; 1347 struct netfront_info *info; 1348 1349 netdev = xennet_create_dev(dev); 1350 if (IS_ERR(netdev)) { 1351 err = PTR_ERR(netdev); 1352 xenbus_dev_fatal(dev, err, "creating netdev"); 1353 return err; 1354 } 1355 1356 info = netdev_priv(netdev); 1357 dev_set_drvdata(&dev->dev, info); 1358 #ifdef CONFIG_SYSFS 1359 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1360 #endif 1361 err = register_netdev(info->netdev); 1362 if (err) { 1363 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1364 goto fail; 1365 } 1366 1367 return 0; 1368 1369 fail: 1370 xennet_free_netdev(netdev); 1371 dev_set_drvdata(&dev->dev, NULL); 1372 return err; 1373 } 1374 1375 static void xennet_end_access(int ref, void *page) 1376 { 1377 /* This frees the page as a side-effect */ 1378 if (ref != GRANT_INVALID_REF) 1379 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1380 } 1381 1382 static void xennet_disconnect_backend(struct netfront_info *info) 1383 { 1384 unsigned int i = 0; 1385 unsigned int num_queues = info->netdev->real_num_tx_queues; 1386 1387 netif_carrier_off(info->netdev); 1388 1389 for (i = 0; i < num_queues && info->queues; ++i) { 1390 struct netfront_queue *queue = &info->queues[i]; 1391 1392 del_timer_sync(&queue->rx_refill_timer); 1393 1394 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1395 unbind_from_irqhandler(queue->tx_irq, queue); 1396 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1397 unbind_from_irqhandler(queue->tx_irq, queue); 1398 unbind_from_irqhandler(queue->rx_irq, queue); 1399 } 1400 queue->tx_evtchn = queue->rx_evtchn = 0; 1401 queue->tx_irq = queue->rx_irq = 0; 1402 1403 if (netif_running(info->netdev)) 1404 napi_synchronize(&queue->napi); 1405 1406 xennet_release_tx_bufs(queue); 1407 xennet_release_rx_bufs(queue); 1408 gnttab_free_grant_references(queue->gref_tx_head); 1409 gnttab_free_grant_references(queue->gref_rx_head); 1410 1411 /* End access and free the pages */ 1412 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1413 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1414 1415 queue->tx_ring_ref = GRANT_INVALID_REF; 1416 queue->rx_ring_ref = GRANT_INVALID_REF; 1417 queue->tx.sring = NULL; 1418 queue->rx.sring = NULL; 1419 } 1420 } 1421 1422 /** 1423 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1424 * driver restart. We tear down our netif structure and recreate it, but 1425 * leave the device-layer structures intact so that this is transparent to the 1426 * rest of the kernel. 1427 */ 1428 static int netfront_resume(struct xenbus_device *dev) 1429 { 1430 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1431 1432 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1433 1434 xennet_disconnect_backend(info); 1435 return 0; 1436 } 1437 1438 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1439 { 1440 char *s, *e, *macstr; 1441 int i; 1442 1443 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1444 if (IS_ERR(macstr)) 1445 return PTR_ERR(macstr); 1446 1447 for (i = 0; i < ETH_ALEN; i++) { 1448 mac[i] = simple_strtoul(s, &e, 16); 1449 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1450 kfree(macstr); 1451 return -ENOENT; 1452 } 1453 s = e+1; 1454 } 1455 1456 kfree(macstr); 1457 return 0; 1458 } 1459 1460 static int setup_netfront_single(struct netfront_queue *queue) 1461 { 1462 int err; 1463 1464 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1465 if (err < 0) 1466 goto fail; 1467 1468 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1469 xennet_interrupt, 1470 0, queue->info->netdev->name, queue); 1471 if (err < 0) 1472 goto bind_fail; 1473 queue->rx_evtchn = queue->tx_evtchn; 1474 queue->rx_irq = queue->tx_irq = err; 1475 1476 return 0; 1477 1478 bind_fail: 1479 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1480 queue->tx_evtchn = 0; 1481 fail: 1482 return err; 1483 } 1484 1485 static int setup_netfront_split(struct netfront_queue *queue) 1486 { 1487 int err; 1488 1489 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1490 if (err < 0) 1491 goto fail; 1492 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1493 if (err < 0) 1494 goto alloc_rx_evtchn_fail; 1495 1496 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1497 "%s-tx", queue->name); 1498 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1499 xennet_tx_interrupt, 1500 0, queue->tx_irq_name, queue); 1501 if (err < 0) 1502 goto bind_tx_fail; 1503 queue->tx_irq = err; 1504 1505 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1506 "%s-rx", queue->name); 1507 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1508 xennet_rx_interrupt, 1509 0, queue->rx_irq_name, queue); 1510 if (err < 0) 1511 goto bind_rx_fail; 1512 queue->rx_irq = err; 1513 1514 return 0; 1515 1516 bind_rx_fail: 1517 unbind_from_irqhandler(queue->tx_irq, queue); 1518 queue->tx_irq = 0; 1519 bind_tx_fail: 1520 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1521 queue->rx_evtchn = 0; 1522 alloc_rx_evtchn_fail: 1523 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1524 queue->tx_evtchn = 0; 1525 fail: 1526 return err; 1527 } 1528 1529 static int setup_netfront(struct xenbus_device *dev, 1530 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1531 { 1532 struct xen_netif_tx_sring *txs; 1533 struct xen_netif_rx_sring *rxs; 1534 grant_ref_t gref; 1535 int err; 1536 1537 queue->tx_ring_ref = GRANT_INVALID_REF; 1538 queue->rx_ring_ref = GRANT_INVALID_REF; 1539 queue->rx.sring = NULL; 1540 queue->tx.sring = NULL; 1541 1542 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1543 if (!txs) { 1544 err = -ENOMEM; 1545 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1546 goto fail; 1547 } 1548 SHARED_RING_INIT(txs); 1549 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); 1550 1551 err = xenbus_grant_ring(dev, txs, 1, &gref); 1552 if (err < 0) 1553 goto grant_tx_ring_fail; 1554 queue->tx_ring_ref = gref; 1555 1556 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1557 if (!rxs) { 1558 err = -ENOMEM; 1559 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1560 goto alloc_rx_ring_fail; 1561 } 1562 SHARED_RING_INIT(rxs); 1563 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); 1564 1565 err = xenbus_grant_ring(dev, rxs, 1, &gref); 1566 if (err < 0) 1567 goto grant_rx_ring_fail; 1568 queue->rx_ring_ref = gref; 1569 1570 if (feature_split_evtchn) 1571 err = setup_netfront_split(queue); 1572 /* setup single event channel if 1573 * a) feature-split-event-channels == 0 1574 * b) feature-split-event-channels == 1 but failed to setup 1575 */ 1576 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1577 err = setup_netfront_single(queue); 1578 1579 if (err) 1580 goto alloc_evtchn_fail; 1581 1582 return 0; 1583 1584 /* If we fail to setup netfront, it is safe to just revoke access to 1585 * granted pages because backend is not accessing it at this point. 1586 */ 1587 alloc_evtchn_fail: 1588 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1589 grant_rx_ring_fail: 1590 free_page((unsigned long)rxs); 1591 alloc_rx_ring_fail: 1592 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1593 grant_tx_ring_fail: 1594 free_page((unsigned long)txs); 1595 fail: 1596 return err; 1597 } 1598 1599 /* Queue-specific initialisation 1600 * This used to be done in xennet_create_dev() but must now 1601 * be run per-queue. 1602 */ 1603 static int xennet_init_queue(struct netfront_queue *queue) 1604 { 1605 unsigned short i; 1606 int err = 0; 1607 1608 spin_lock_init(&queue->tx_lock); 1609 spin_lock_init(&queue->rx_lock); 1610 1611 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); 1612 1613 snprintf(queue->name, sizeof(queue->name), "%s-q%u", 1614 queue->info->netdev->name, queue->id); 1615 1616 /* Initialise tx_skbs as a free chain containing every entry. */ 1617 queue->tx_skb_freelist = 0; 1618 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1619 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1620 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1621 queue->grant_tx_page[i] = NULL; 1622 } 1623 1624 /* Clear out rx_skbs */ 1625 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1626 queue->rx_skbs[i] = NULL; 1627 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1628 } 1629 1630 /* A grant for every tx ring slot */ 1631 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1632 &queue->gref_tx_head) < 0) { 1633 pr_alert("can't alloc tx grant refs\n"); 1634 err = -ENOMEM; 1635 goto exit; 1636 } 1637 1638 /* A grant for every rx ring slot */ 1639 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1640 &queue->gref_rx_head) < 0) { 1641 pr_alert("can't alloc rx grant refs\n"); 1642 err = -ENOMEM; 1643 goto exit_free_tx; 1644 } 1645 1646 return 0; 1647 1648 exit_free_tx: 1649 gnttab_free_grant_references(queue->gref_tx_head); 1650 exit: 1651 return err; 1652 } 1653 1654 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1655 struct xenbus_transaction *xbt, int write_hierarchical) 1656 { 1657 /* Write the queue-specific keys into XenStore in the traditional 1658 * way for a single queue, or in a queue subkeys for multiple 1659 * queues. 1660 */ 1661 struct xenbus_device *dev = queue->info->xbdev; 1662 int err; 1663 const char *message; 1664 char *path; 1665 size_t pathsize; 1666 1667 /* Choose the correct place to write the keys */ 1668 if (write_hierarchical) { 1669 pathsize = strlen(dev->nodename) + 10; 1670 path = kzalloc(pathsize, GFP_KERNEL); 1671 if (!path) { 1672 err = -ENOMEM; 1673 message = "out of memory while writing ring references"; 1674 goto error; 1675 } 1676 snprintf(path, pathsize, "%s/queue-%u", 1677 dev->nodename, queue->id); 1678 } else { 1679 path = (char *)dev->nodename; 1680 } 1681 1682 /* Write ring references */ 1683 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1684 queue->tx_ring_ref); 1685 if (err) { 1686 message = "writing tx-ring-ref"; 1687 goto error; 1688 } 1689 1690 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1691 queue->rx_ring_ref); 1692 if (err) { 1693 message = "writing rx-ring-ref"; 1694 goto error; 1695 } 1696 1697 /* Write event channels; taking into account both shared 1698 * and split event channel scenarios. 1699 */ 1700 if (queue->tx_evtchn == queue->rx_evtchn) { 1701 /* Shared event channel */ 1702 err = xenbus_printf(*xbt, path, 1703 "event-channel", "%u", queue->tx_evtchn); 1704 if (err) { 1705 message = "writing event-channel"; 1706 goto error; 1707 } 1708 } else { 1709 /* Split event channels */ 1710 err = xenbus_printf(*xbt, path, 1711 "event-channel-tx", "%u", queue->tx_evtchn); 1712 if (err) { 1713 message = "writing event-channel-tx"; 1714 goto error; 1715 } 1716 1717 err = xenbus_printf(*xbt, path, 1718 "event-channel-rx", "%u", queue->rx_evtchn); 1719 if (err) { 1720 message = "writing event-channel-rx"; 1721 goto error; 1722 } 1723 } 1724 1725 if (write_hierarchical) 1726 kfree(path); 1727 return 0; 1728 1729 error: 1730 if (write_hierarchical) 1731 kfree(path); 1732 xenbus_dev_fatal(dev, err, "%s", message); 1733 return err; 1734 } 1735 1736 static void xennet_destroy_queues(struct netfront_info *info) 1737 { 1738 unsigned int i; 1739 1740 rtnl_lock(); 1741 1742 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1743 struct netfront_queue *queue = &info->queues[i]; 1744 1745 if (netif_running(info->netdev)) 1746 napi_disable(&queue->napi); 1747 netif_napi_del(&queue->napi); 1748 } 1749 1750 rtnl_unlock(); 1751 1752 kfree(info->queues); 1753 info->queues = NULL; 1754 } 1755 1756 static int xennet_create_queues(struct netfront_info *info, 1757 unsigned int *num_queues) 1758 { 1759 unsigned int i; 1760 int ret; 1761 1762 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), 1763 GFP_KERNEL); 1764 if (!info->queues) 1765 return -ENOMEM; 1766 1767 rtnl_lock(); 1768 1769 for (i = 0; i < *num_queues; i++) { 1770 struct netfront_queue *queue = &info->queues[i]; 1771 1772 queue->id = i; 1773 queue->info = info; 1774 1775 ret = xennet_init_queue(queue); 1776 if (ret < 0) { 1777 dev_warn(&info->netdev->dev, 1778 "only created %d queues\n", i); 1779 *num_queues = i; 1780 break; 1781 } 1782 1783 netif_napi_add(queue->info->netdev, &queue->napi, 1784 xennet_poll, 64); 1785 if (netif_running(info->netdev)) 1786 napi_enable(&queue->napi); 1787 } 1788 1789 netif_set_real_num_tx_queues(info->netdev, *num_queues); 1790 1791 rtnl_unlock(); 1792 1793 if (*num_queues == 0) { 1794 dev_err(&info->netdev->dev, "no queues\n"); 1795 return -EINVAL; 1796 } 1797 return 0; 1798 } 1799 1800 /* Common code used when first setting up, and when resuming. */ 1801 static int talk_to_netback(struct xenbus_device *dev, 1802 struct netfront_info *info) 1803 { 1804 const char *message; 1805 struct xenbus_transaction xbt; 1806 int err; 1807 unsigned int feature_split_evtchn; 1808 unsigned int i = 0; 1809 unsigned int max_queues = 0; 1810 struct netfront_queue *queue = NULL; 1811 unsigned int num_queues = 1; 1812 1813 info->netdev->irq = 0; 1814 1815 /* Check if backend supports multiple queues */ 1816 max_queues = xenbus_read_unsigned(info->xbdev->otherend, 1817 "multi-queue-max-queues", 1); 1818 num_queues = min(max_queues, xennet_max_queues); 1819 1820 /* Check feature-split-event-channels */ 1821 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, 1822 "feature-split-event-channels", 0); 1823 1824 /* Read mac addr. */ 1825 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1826 if (err) { 1827 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1828 goto out; 1829 } 1830 1831 if (info->queues) 1832 xennet_destroy_queues(info); 1833 1834 err = xennet_create_queues(info, &num_queues); 1835 if (err < 0) { 1836 xenbus_dev_fatal(dev, err, "creating queues"); 1837 kfree(info->queues); 1838 info->queues = NULL; 1839 goto out; 1840 } 1841 1842 /* Create shared ring, alloc event channel -- for each queue */ 1843 for (i = 0; i < num_queues; ++i) { 1844 queue = &info->queues[i]; 1845 err = setup_netfront(dev, queue, feature_split_evtchn); 1846 if (err) 1847 goto destroy_ring; 1848 } 1849 1850 again: 1851 err = xenbus_transaction_start(&xbt); 1852 if (err) { 1853 xenbus_dev_fatal(dev, err, "starting transaction"); 1854 goto destroy_ring; 1855 } 1856 1857 if (xenbus_exists(XBT_NIL, 1858 info->xbdev->otherend, "multi-queue-max-queues")) { 1859 /* Write the number of queues */ 1860 err = xenbus_printf(xbt, dev->nodename, 1861 "multi-queue-num-queues", "%u", num_queues); 1862 if (err) { 1863 message = "writing multi-queue-num-queues"; 1864 goto abort_transaction_no_dev_fatal; 1865 } 1866 } 1867 1868 if (num_queues == 1) { 1869 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1870 if (err) 1871 goto abort_transaction_no_dev_fatal; 1872 } else { 1873 /* Write the keys for each queue */ 1874 for (i = 0; i < num_queues; ++i) { 1875 queue = &info->queues[i]; 1876 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1877 if (err) 1878 goto abort_transaction_no_dev_fatal; 1879 } 1880 } 1881 1882 /* The remaining keys are not queue-specific */ 1883 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1884 1); 1885 if (err) { 1886 message = "writing request-rx-copy"; 1887 goto abort_transaction; 1888 } 1889 1890 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1891 if (err) { 1892 message = "writing feature-rx-notify"; 1893 goto abort_transaction; 1894 } 1895 1896 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1897 if (err) { 1898 message = "writing feature-sg"; 1899 goto abort_transaction; 1900 } 1901 1902 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1903 if (err) { 1904 message = "writing feature-gso-tcpv4"; 1905 goto abort_transaction; 1906 } 1907 1908 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1909 if (err) { 1910 message = "writing feature-gso-tcpv6"; 1911 goto abort_transaction; 1912 } 1913 1914 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1915 "1"); 1916 if (err) { 1917 message = "writing feature-ipv6-csum-offload"; 1918 goto abort_transaction; 1919 } 1920 1921 err = xenbus_transaction_end(xbt, 0); 1922 if (err) { 1923 if (err == -EAGAIN) 1924 goto again; 1925 xenbus_dev_fatal(dev, err, "completing transaction"); 1926 goto destroy_ring; 1927 } 1928 1929 return 0; 1930 1931 abort_transaction: 1932 xenbus_dev_fatal(dev, err, "%s", message); 1933 abort_transaction_no_dev_fatal: 1934 xenbus_transaction_end(xbt, 1); 1935 destroy_ring: 1936 xennet_disconnect_backend(info); 1937 xennet_destroy_queues(info); 1938 out: 1939 device_unregister(&dev->dev); 1940 return err; 1941 } 1942 1943 static int xennet_connect(struct net_device *dev) 1944 { 1945 struct netfront_info *np = netdev_priv(dev); 1946 unsigned int num_queues = 0; 1947 int err; 1948 unsigned int j = 0; 1949 struct netfront_queue *queue = NULL; 1950 1951 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { 1952 dev_info(&dev->dev, 1953 "backend does not support copying receive path\n"); 1954 return -ENODEV; 1955 } 1956 1957 err = talk_to_netback(np->xbdev, np); 1958 if (err) 1959 return err; 1960 1961 /* talk_to_netback() sets the correct number of queues */ 1962 num_queues = dev->real_num_tx_queues; 1963 1964 rtnl_lock(); 1965 netdev_update_features(dev); 1966 rtnl_unlock(); 1967 1968 /* 1969 * All public and private state should now be sane. Get 1970 * ready to start sending and receiving packets and give the driver 1971 * domain a kick because we've probably just requeued some 1972 * packets. 1973 */ 1974 netif_carrier_on(np->netdev); 1975 for (j = 0; j < num_queues; ++j) { 1976 queue = &np->queues[j]; 1977 1978 notify_remote_via_irq(queue->tx_irq); 1979 if (queue->tx_irq != queue->rx_irq) 1980 notify_remote_via_irq(queue->rx_irq); 1981 1982 spin_lock_irq(&queue->tx_lock); 1983 xennet_tx_buf_gc(queue); 1984 spin_unlock_irq(&queue->tx_lock); 1985 1986 spin_lock_bh(&queue->rx_lock); 1987 xennet_alloc_rx_buffers(queue); 1988 spin_unlock_bh(&queue->rx_lock); 1989 } 1990 1991 return 0; 1992 } 1993 1994 /** 1995 * Callback received when the backend's state changes. 1996 */ 1997 static void netback_changed(struct xenbus_device *dev, 1998 enum xenbus_state backend_state) 1999 { 2000 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2001 struct net_device *netdev = np->netdev; 2002 2003 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2004 2005 switch (backend_state) { 2006 case XenbusStateInitialising: 2007 case XenbusStateInitialised: 2008 case XenbusStateReconfiguring: 2009 case XenbusStateReconfigured: 2010 case XenbusStateUnknown: 2011 break; 2012 2013 case XenbusStateInitWait: 2014 if (dev->state != XenbusStateInitialising) 2015 break; 2016 if (xennet_connect(netdev) != 0) 2017 break; 2018 xenbus_switch_state(dev, XenbusStateConnected); 2019 break; 2020 2021 case XenbusStateConnected: 2022 netdev_notify_peers(netdev); 2023 break; 2024 2025 case XenbusStateClosed: 2026 wake_up_all(&module_unload_q); 2027 if (dev->state == XenbusStateClosed) 2028 break; 2029 /* Missed the backend's CLOSING state -- fallthrough */ 2030 case XenbusStateClosing: 2031 wake_up_all(&module_unload_q); 2032 xenbus_frontend_closed(dev); 2033 break; 2034 } 2035 } 2036 2037 static const struct xennet_stat { 2038 char name[ETH_GSTRING_LEN]; 2039 u16 offset; 2040 } xennet_stats[] = { 2041 { 2042 "rx_gso_checksum_fixup", 2043 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2044 }, 2045 }; 2046 2047 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2048 { 2049 switch (string_set) { 2050 case ETH_SS_STATS: 2051 return ARRAY_SIZE(xennet_stats); 2052 default: 2053 return -EINVAL; 2054 } 2055 } 2056 2057 static void xennet_get_ethtool_stats(struct net_device *dev, 2058 struct ethtool_stats *stats, u64 * data) 2059 { 2060 void *np = netdev_priv(dev); 2061 int i; 2062 2063 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2064 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2065 } 2066 2067 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2068 { 2069 int i; 2070 2071 switch (stringset) { 2072 case ETH_SS_STATS: 2073 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2074 memcpy(data + i * ETH_GSTRING_LEN, 2075 xennet_stats[i].name, ETH_GSTRING_LEN); 2076 break; 2077 } 2078 } 2079 2080 static const struct ethtool_ops xennet_ethtool_ops = 2081 { 2082 .get_link = ethtool_op_get_link, 2083 2084 .get_sset_count = xennet_get_sset_count, 2085 .get_ethtool_stats = xennet_get_ethtool_stats, 2086 .get_strings = xennet_get_strings, 2087 }; 2088 2089 #ifdef CONFIG_SYSFS 2090 static ssize_t show_rxbuf(struct device *dev, 2091 struct device_attribute *attr, char *buf) 2092 { 2093 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2094 } 2095 2096 static ssize_t store_rxbuf(struct device *dev, 2097 struct device_attribute *attr, 2098 const char *buf, size_t len) 2099 { 2100 char *endp; 2101 unsigned long target; 2102 2103 if (!capable(CAP_NET_ADMIN)) 2104 return -EPERM; 2105 2106 target = simple_strtoul(buf, &endp, 0); 2107 if (endp == buf) 2108 return -EBADMSG; 2109 2110 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2111 2112 return len; 2113 } 2114 2115 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf); 2116 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf); 2117 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL); 2118 2119 static struct attribute *xennet_dev_attrs[] = { 2120 &dev_attr_rxbuf_min.attr, 2121 &dev_attr_rxbuf_max.attr, 2122 &dev_attr_rxbuf_cur.attr, 2123 NULL 2124 }; 2125 2126 static const struct attribute_group xennet_dev_group = { 2127 .attrs = xennet_dev_attrs 2128 }; 2129 #endif /* CONFIG_SYSFS */ 2130 2131 static int xennet_remove(struct xenbus_device *dev) 2132 { 2133 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2134 2135 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2136 2137 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) { 2138 xenbus_switch_state(dev, XenbusStateClosing); 2139 wait_event(module_unload_q, 2140 xenbus_read_driver_state(dev->otherend) == 2141 XenbusStateClosing); 2142 2143 xenbus_switch_state(dev, XenbusStateClosed); 2144 wait_event(module_unload_q, 2145 xenbus_read_driver_state(dev->otherend) == 2146 XenbusStateClosed || 2147 xenbus_read_driver_state(dev->otherend) == 2148 XenbusStateUnknown); 2149 } 2150 2151 xennet_disconnect_backend(info); 2152 2153 unregister_netdev(info->netdev); 2154 2155 if (info->queues) 2156 xennet_destroy_queues(info); 2157 xennet_free_netdev(info->netdev); 2158 2159 return 0; 2160 } 2161 2162 static const struct xenbus_device_id netfront_ids[] = { 2163 { "vif" }, 2164 { "" } 2165 }; 2166 2167 static struct xenbus_driver netfront_driver = { 2168 .ids = netfront_ids, 2169 .probe = netfront_probe, 2170 .remove = xennet_remove, 2171 .resume = netfront_resume, 2172 .otherend_changed = netback_changed, 2173 }; 2174 2175 static int __init netif_init(void) 2176 { 2177 if (!xen_domain()) 2178 return -ENODEV; 2179 2180 if (!xen_has_pv_nic_devices()) 2181 return -ENODEV; 2182 2183 pr_info("Initialising Xen virtual ethernet driver\n"); 2184 2185 /* Allow as many queues as there are CPUs inut max. 8 if user has not 2186 * specified a value. 2187 */ 2188 if (xennet_max_queues == 0) 2189 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, 2190 num_online_cpus()); 2191 2192 return xenbus_register_frontend(&netfront_driver); 2193 } 2194 module_init(netif_init); 2195 2196 2197 static void __exit netif_exit(void) 2198 { 2199 xenbus_unregister_driver(&netfront_driver); 2200 } 2201 module_exit(netif_exit); 2202 2203 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2204 MODULE_LICENSE("GPL"); 2205 MODULE_ALIAS("xen:vif"); 2206 MODULE_ALIAS("xennet"); 2207