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_wq); 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 - XEN_NETIF_NR_SLOTS_MIN - 1); 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 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 341 if (notify) 342 notify_remote_via_irq(queue->rx_irq); 343 } 344 345 static int xennet_open(struct net_device *dev) 346 { 347 struct netfront_info *np = netdev_priv(dev); 348 unsigned int num_queues = dev->real_num_tx_queues; 349 unsigned int i = 0; 350 struct netfront_queue *queue = NULL; 351 352 if (!np->queues) 353 return -ENODEV; 354 355 for (i = 0; i < num_queues; ++i) { 356 queue = &np->queues[i]; 357 napi_enable(&queue->napi); 358 359 spin_lock_bh(&queue->rx_lock); 360 if (netif_carrier_ok(dev)) { 361 xennet_alloc_rx_buffers(queue); 362 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 363 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 364 napi_schedule(&queue->napi); 365 } 366 spin_unlock_bh(&queue->rx_lock); 367 } 368 369 netif_tx_start_all_queues(dev); 370 371 return 0; 372 } 373 374 static void xennet_tx_buf_gc(struct netfront_queue *queue) 375 { 376 RING_IDX cons, prod; 377 unsigned short id; 378 struct sk_buff *skb; 379 bool more_to_do; 380 381 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 382 383 do { 384 prod = queue->tx.sring->rsp_prod; 385 rmb(); /* Ensure we see responses up to 'rp'. */ 386 387 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 388 struct xen_netif_tx_response *txrsp; 389 390 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 391 if (txrsp->status == XEN_NETIF_RSP_NULL) 392 continue; 393 394 id = txrsp->id; 395 skb = queue->tx_skbs[id].skb; 396 if (unlikely(gnttab_query_foreign_access( 397 queue->grant_tx_ref[id]) != 0)) { 398 pr_alert("%s: warning -- grant still in use by backend domain\n", 399 __func__); 400 BUG(); 401 } 402 gnttab_end_foreign_access_ref( 403 queue->grant_tx_ref[id], GNTMAP_readonly); 404 gnttab_release_grant_reference( 405 &queue->gref_tx_head, queue->grant_tx_ref[id]); 406 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 407 queue->grant_tx_page[id] = NULL; 408 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 409 dev_kfree_skb_irq(skb); 410 } 411 412 queue->tx.rsp_cons = prod; 413 414 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); 415 } while (more_to_do); 416 417 xennet_maybe_wake_tx(queue); 418 } 419 420 struct xennet_gnttab_make_txreq { 421 struct netfront_queue *queue; 422 struct sk_buff *skb; 423 struct page *page; 424 struct xen_netif_tx_request *tx; /* Last request */ 425 unsigned int size; 426 }; 427 428 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, 429 unsigned int len, void *data) 430 { 431 struct xennet_gnttab_make_txreq *info = data; 432 unsigned int id; 433 struct xen_netif_tx_request *tx; 434 grant_ref_t ref; 435 /* convenient aliases */ 436 struct page *page = info->page; 437 struct netfront_queue *queue = info->queue; 438 struct sk_buff *skb = info->skb; 439 440 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 441 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 442 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 443 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 444 445 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 446 gfn, GNTMAP_readonly); 447 448 queue->tx_skbs[id].skb = skb; 449 queue->grant_tx_page[id] = page; 450 queue->grant_tx_ref[id] = ref; 451 452 tx->id = id; 453 tx->gref = ref; 454 tx->offset = offset; 455 tx->size = len; 456 tx->flags = 0; 457 458 info->tx = tx; 459 info->size += tx->size; 460 } 461 462 static struct xen_netif_tx_request *xennet_make_first_txreq( 463 struct netfront_queue *queue, struct sk_buff *skb, 464 struct page *page, unsigned int offset, unsigned int len) 465 { 466 struct xennet_gnttab_make_txreq info = { 467 .queue = queue, 468 .skb = skb, 469 .page = page, 470 .size = 0, 471 }; 472 473 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info); 474 475 return info.tx; 476 } 477 478 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, 479 unsigned int len, void *data) 480 { 481 struct xennet_gnttab_make_txreq *info = data; 482 483 info->tx->flags |= XEN_NETTXF_more_data; 484 skb_get(info->skb); 485 xennet_tx_setup_grant(gfn, offset, len, data); 486 } 487 488 static struct xen_netif_tx_request *xennet_make_txreqs( 489 struct netfront_queue *queue, struct xen_netif_tx_request *tx, 490 struct sk_buff *skb, struct page *page, 491 unsigned int offset, unsigned int len) 492 { 493 struct xennet_gnttab_make_txreq info = { 494 .queue = queue, 495 .skb = skb, 496 .tx = tx, 497 }; 498 499 /* Skip unused frames from start of page */ 500 page += offset >> PAGE_SHIFT; 501 offset &= ~PAGE_MASK; 502 503 while (len) { 504 info.page = page; 505 info.size = 0; 506 507 gnttab_foreach_grant_in_range(page, offset, len, 508 xennet_make_one_txreq, 509 &info); 510 511 page++; 512 offset = 0; 513 len -= info.size; 514 } 515 516 return info.tx; 517 } 518 519 /* 520 * Count how many ring slots are required to send this skb. Each frag 521 * might be a compound page. 522 */ 523 static int xennet_count_skb_slots(struct sk_buff *skb) 524 { 525 int i, frags = skb_shinfo(skb)->nr_frags; 526 int slots; 527 528 slots = gnttab_count_grant(offset_in_page(skb->data), 529 skb_headlen(skb)); 530 531 for (i = 0; i < frags; i++) { 532 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 533 unsigned long size = skb_frag_size(frag); 534 unsigned long offset = frag->page_offset; 535 536 /* Skip unused frames from start of page */ 537 offset &= ~PAGE_MASK; 538 539 slots += gnttab_count_grant(offset, size); 540 } 541 542 return slots; 543 } 544 545 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 546 struct net_device *sb_dev, 547 select_queue_fallback_t fallback) 548 { 549 unsigned int num_queues = dev->real_num_tx_queues; 550 u32 hash; 551 u16 queue_idx; 552 553 /* First, check if there is only one queue */ 554 if (num_queues == 1) { 555 queue_idx = 0; 556 } else { 557 hash = skb_get_hash(skb); 558 queue_idx = hash % num_queues; 559 } 560 561 return queue_idx; 562 } 563 564 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) 565 566 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 567 { 568 struct netfront_info *np = netdev_priv(dev); 569 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 570 struct xen_netif_tx_request *tx, *first_tx; 571 unsigned int i; 572 int notify; 573 int slots; 574 struct page *page; 575 unsigned int offset; 576 unsigned int len; 577 unsigned long flags; 578 struct netfront_queue *queue = NULL; 579 unsigned int num_queues = dev->real_num_tx_queues; 580 u16 queue_index; 581 struct sk_buff *nskb; 582 583 /* Drop the packet if no queues are set up */ 584 if (num_queues < 1) 585 goto drop; 586 /* Determine which queue to transmit this SKB on */ 587 queue_index = skb_get_queue_mapping(skb); 588 queue = &np->queues[queue_index]; 589 590 /* If skb->len is too big for wire format, drop skb and alert 591 * user about misconfiguration. 592 */ 593 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 594 net_alert_ratelimited( 595 "xennet: skb->len = %u, too big for wire format\n", 596 skb->len); 597 goto drop; 598 } 599 600 slots = xennet_count_skb_slots(skb); 601 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { 602 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 603 slots, skb->len); 604 if (skb_linearize(skb)) 605 goto drop; 606 } 607 608 page = virt_to_page(skb->data); 609 offset = offset_in_page(skb->data); 610 611 /* The first req should be at least ETH_HLEN size or the packet will be 612 * dropped by netback. 613 */ 614 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { 615 nskb = skb_copy(skb, GFP_ATOMIC); 616 if (!nskb) 617 goto drop; 618 dev_consume_skb_any(skb); 619 skb = nskb; 620 page = virt_to_page(skb->data); 621 offset = offset_in_page(skb->data); 622 } 623 624 len = skb_headlen(skb); 625 626 spin_lock_irqsave(&queue->tx_lock, flags); 627 628 if (unlikely(!netif_carrier_ok(dev) || 629 (slots > 1 && !xennet_can_sg(dev)) || 630 netif_needs_gso(skb, netif_skb_features(skb)))) { 631 spin_unlock_irqrestore(&queue->tx_lock, flags); 632 goto drop; 633 } 634 635 /* First request for the linear area. */ 636 first_tx = tx = xennet_make_first_txreq(queue, skb, 637 page, offset, len); 638 offset += tx->size; 639 if (offset == PAGE_SIZE) { 640 page++; 641 offset = 0; 642 } 643 len -= tx->size; 644 645 if (skb->ip_summed == CHECKSUM_PARTIAL) 646 /* local packet? */ 647 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 648 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 649 /* remote but checksummed. */ 650 tx->flags |= XEN_NETTXF_data_validated; 651 652 /* Optional extra info after the first request. */ 653 if (skb_shinfo(skb)->gso_size) { 654 struct xen_netif_extra_info *gso; 655 656 gso = (struct xen_netif_extra_info *) 657 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 658 659 tx->flags |= XEN_NETTXF_extra_info; 660 661 gso->u.gso.size = skb_shinfo(skb)->gso_size; 662 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 663 XEN_NETIF_GSO_TYPE_TCPV6 : 664 XEN_NETIF_GSO_TYPE_TCPV4; 665 gso->u.gso.pad = 0; 666 gso->u.gso.features = 0; 667 668 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 669 gso->flags = 0; 670 } 671 672 /* Requests for the rest of the linear area. */ 673 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); 674 675 /* Requests for all the frags. */ 676 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 677 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 678 tx = xennet_make_txreqs(queue, tx, skb, 679 skb_frag_page(frag), frag->page_offset, 680 skb_frag_size(frag)); 681 } 682 683 /* First request has the packet length. */ 684 first_tx->size = skb->len; 685 686 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 687 if (notify) 688 notify_remote_via_irq(queue->tx_irq); 689 690 u64_stats_update_begin(&tx_stats->syncp); 691 tx_stats->bytes += skb->len; 692 tx_stats->packets++; 693 u64_stats_update_end(&tx_stats->syncp); 694 695 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 696 xennet_tx_buf_gc(queue); 697 698 if (!netfront_tx_slot_available(queue)) 699 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 700 701 spin_unlock_irqrestore(&queue->tx_lock, flags); 702 703 return NETDEV_TX_OK; 704 705 drop: 706 dev->stats.tx_dropped++; 707 dev_kfree_skb_any(skb); 708 return NETDEV_TX_OK; 709 } 710 711 static int xennet_close(struct net_device *dev) 712 { 713 struct netfront_info *np = netdev_priv(dev); 714 unsigned int num_queues = dev->real_num_tx_queues; 715 unsigned int i; 716 struct netfront_queue *queue; 717 netif_tx_stop_all_queues(np->netdev); 718 for (i = 0; i < num_queues; ++i) { 719 queue = &np->queues[i]; 720 napi_disable(&queue->napi); 721 } 722 return 0; 723 } 724 725 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 726 grant_ref_t ref) 727 { 728 int new = xennet_rxidx(queue->rx.req_prod_pvt); 729 730 BUG_ON(queue->rx_skbs[new]); 731 queue->rx_skbs[new] = skb; 732 queue->grant_rx_ref[new] = ref; 733 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 734 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 735 queue->rx.req_prod_pvt++; 736 } 737 738 static int xennet_get_extras(struct netfront_queue *queue, 739 struct xen_netif_extra_info *extras, 740 RING_IDX rp) 741 742 { 743 struct xen_netif_extra_info *extra; 744 struct device *dev = &queue->info->netdev->dev; 745 RING_IDX cons = queue->rx.rsp_cons; 746 int err = 0; 747 748 do { 749 struct sk_buff *skb; 750 grant_ref_t ref; 751 752 if (unlikely(cons + 1 == rp)) { 753 if (net_ratelimit()) 754 dev_warn(dev, "Missing extra info\n"); 755 err = -EBADR; 756 break; 757 } 758 759 extra = (struct xen_netif_extra_info *) 760 RING_GET_RESPONSE(&queue->rx, ++cons); 761 762 if (unlikely(!extra->type || 763 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 764 if (net_ratelimit()) 765 dev_warn(dev, "Invalid extra type: %d\n", 766 extra->type); 767 err = -EINVAL; 768 } else { 769 memcpy(&extras[extra->type - 1], extra, 770 sizeof(*extra)); 771 } 772 773 skb = xennet_get_rx_skb(queue, cons); 774 ref = xennet_get_rx_ref(queue, cons); 775 xennet_move_rx_slot(queue, skb, ref); 776 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 777 778 queue->rx.rsp_cons = cons; 779 return err; 780 } 781 782 static int xennet_get_responses(struct netfront_queue *queue, 783 struct netfront_rx_info *rinfo, RING_IDX rp, 784 struct sk_buff_head *list) 785 { 786 struct xen_netif_rx_response *rx = &rinfo->rx; 787 struct xen_netif_extra_info *extras = rinfo->extras; 788 struct device *dev = &queue->info->netdev->dev; 789 RING_IDX cons = queue->rx.rsp_cons; 790 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 791 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 792 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD); 793 int slots = 1; 794 int err = 0; 795 unsigned long ret; 796 797 if (rx->flags & XEN_NETRXF_extra_info) { 798 err = xennet_get_extras(queue, extras, rp); 799 cons = queue->rx.rsp_cons; 800 } 801 802 for (;;) { 803 if (unlikely(rx->status < 0 || 804 rx->offset + rx->status > XEN_PAGE_SIZE)) { 805 if (net_ratelimit()) 806 dev_warn(dev, "rx->offset: %u, size: %d\n", 807 rx->offset, rx->status); 808 xennet_move_rx_slot(queue, skb, ref); 809 err = -EINVAL; 810 goto next; 811 } 812 813 /* 814 * This definitely indicates a bug, either in this driver or in 815 * the backend driver. In future this should flag the bad 816 * situation to the system controller to reboot the backend. 817 */ 818 if (ref == GRANT_INVALID_REF) { 819 if (net_ratelimit()) 820 dev_warn(dev, "Bad rx response id %d.\n", 821 rx->id); 822 err = -EINVAL; 823 goto next; 824 } 825 826 ret = gnttab_end_foreign_access_ref(ref, 0); 827 BUG_ON(!ret); 828 829 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 830 831 __skb_queue_tail(list, skb); 832 833 next: 834 if (!(rx->flags & XEN_NETRXF_more_data)) 835 break; 836 837 if (cons + slots == rp) { 838 if (net_ratelimit()) 839 dev_warn(dev, "Need more slots\n"); 840 err = -ENOENT; 841 break; 842 } 843 844 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 845 skb = xennet_get_rx_skb(queue, cons + slots); 846 ref = xennet_get_rx_ref(queue, cons + slots); 847 slots++; 848 } 849 850 if (unlikely(slots > max)) { 851 if (net_ratelimit()) 852 dev_warn(dev, "Too many slots\n"); 853 err = -E2BIG; 854 } 855 856 if (unlikely(err)) 857 queue->rx.rsp_cons = cons + slots; 858 859 return err; 860 } 861 862 static int xennet_set_skb_gso(struct sk_buff *skb, 863 struct xen_netif_extra_info *gso) 864 { 865 if (!gso->u.gso.size) { 866 if (net_ratelimit()) 867 pr_warn("GSO size must not be zero\n"); 868 return -EINVAL; 869 } 870 871 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 872 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 873 if (net_ratelimit()) 874 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 875 return -EINVAL; 876 } 877 878 skb_shinfo(skb)->gso_size = gso->u.gso.size; 879 skb_shinfo(skb)->gso_type = 880 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 881 SKB_GSO_TCPV4 : 882 SKB_GSO_TCPV6; 883 884 /* Header must be checked, and gso_segs computed. */ 885 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 886 skb_shinfo(skb)->gso_segs = 0; 887 888 return 0; 889 } 890 891 static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 892 struct sk_buff *skb, 893 struct sk_buff_head *list) 894 { 895 RING_IDX cons = queue->rx.rsp_cons; 896 struct sk_buff *nskb; 897 898 while ((nskb = __skb_dequeue(list))) { 899 struct xen_netif_rx_response *rx = 900 RING_GET_RESPONSE(&queue->rx, ++cons); 901 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 902 903 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { 904 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 905 906 BUG_ON(pull_to < skb_headlen(skb)); 907 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 908 } 909 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) { 910 queue->rx.rsp_cons = ++cons; 911 kfree_skb(nskb); 912 return ~0U; 913 } 914 915 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 916 skb_frag_page(nfrag), 917 rx->offset, rx->status, PAGE_SIZE); 918 919 skb_shinfo(nskb)->nr_frags = 0; 920 kfree_skb(nskb); 921 } 922 923 return cons; 924 } 925 926 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 927 { 928 bool recalculate_partial_csum = false; 929 930 /* 931 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 932 * peers can fail to set NETRXF_csum_blank when sending a GSO 933 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 934 * recalculate the partial checksum. 935 */ 936 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 937 struct netfront_info *np = netdev_priv(dev); 938 atomic_inc(&np->rx_gso_checksum_fixup); 939 skb->ip_summed = CHECKSUM_PARTIAL; 940 recalculate_partial_csum = true; 941 } 942 943 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 944 if (skb->ip_summed != CHECKSUM_PARTIAL) 945 return 0; 946 947 return skb_checksum_setup(skb, recalculate_partial_csum); 948 } 949 950 static int handle_incoming_queue(struct netfront_queue *queue, 951 struct sk_buff_head *rxq) 952 { 953 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 954 int packets_dropped = 0; 955 struct sk_buff *skb; 956 957 while ((skb = __skb_dequeue(rxq)) != NULL) { 958 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 959 960 if (pull_to > skb_headlen(skb)) 961 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 962 963 /* Ethernet work: Delayed to here as it peeks the header. */ 964 skb->protocol = eth_type_trans(skb, queue->info->netdev); 965 skb_reset_network_header(skb); 966 967 if (checksum_setup(queue->info->netdev, skb)) { 968 kfree_skb(skb); 969 packets_dropped++; 970 queue->info->netdev->stats.rx_errors++; 971 continue; 972 } 973 974 u64_stats_update_begin(&rx_stats->syncp); 975 rx_stats->packets++; 976 rx_stats->bytes += skb->len; 977 u64_stats_update_end(&rx_stats->syncp); 978 979 /* Pass it up. */ 980 napi_gro_receive(&queue->napi, skb); 981 } 982 983 return packets_dropped; 984 } 985 986 static int xennet_poll(struct napi_struct *napi, int budget) 987 { 988 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 989 struct net_device *dev = queue->info->netdev; 990 struct sk_buff *skb; 991 struct netfront_rx_info rinfo; 992 struct xen_netif_rx_response *rx = &rinfo.rx; 993 struct xen_netif_extra_info *extras = rinfo.extras; 994 RING_IDX i, rp; 995 int work_done; 996 struct sk_buff_head rxq; 997 struct sk_buff_head errq; 998 struct sk_buff_head tmpq; 999 int err; 1000 1001 spin_lock(&queue->rx_lock); 1002 1003 skb_queue_head_init(&rxq); 1004 skb_queue_head_init(&errq); 1005 skb_queue_head_init(&tmpq); 1006 1007 rp = queue->rx.sring->rsp_prod; 1008 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1009 1010 i = queue->rx.rsp_cons; 1011 work_done = 0; 1012 while ((i != rp) && (work_done < budget)) { 1013 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 1014 memset(extras, 0, sizeof(rinfo.extras)); 1015 1016 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 1017 1018 if (unlikely(err)) { 1019 err: 1020 while ((skb = __skb_dequeue(&tmpq))) 1021 __skb_queue_tail(&errq, skb); 1022 dev->stats.rx_errors++; 1023 i = queue->rx.rsp_cons; 1024 continue; 1025 } 1026 1027 skb = __skb_dequeue(&tmpq); 1028 1029 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1030 struct xen_netif_extra_info *gso; 1031 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1032 1033 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1034 __skb_queue_head(&tmpq, skb); 1035 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1036 goto err; 1037 } 1038 } 1039 1040 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1041 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1042 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1043 1044 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1045 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1046 skb->data_len = rx->status; 1047 skb->len += rx->status; 1048 1049 i = xennet_fill_frags(queue, skb, &tmpq); 1050 if (unlikely(i == ~0U)) 1051 goto err; 1052 1053 if (rx->flags & XEN_NETRXF_csum_blank) 1054 skb->ip_summed = CHECKSUM_PARTIAL; 1055 else if (rx->flags & XEN_NETRXF_data_validated) 1056 skb->ip_summed = CHECKSUM_UNNECESSARY; 1057 1058 __skb_queue_tail(&rxq, skb); 1059 1060 queue->rx.rsp_cons = ++i; 1061 work_done++; 1062 } 1063 1064 __skb_queue_purge(&errq); 1065 1066 work_done -= handle_incoming_queue(queue, &rxq); 1067 1068 xennet_alloc_rx_buffers(queue); 1069 1070 if (work_done < budget) { 1071 int more_to_do = 0; 1072 1073 napi_complete_done(napi, work_done); 1074 1075 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1076 if (more_to_do) 1077 napi_schedule(napi); 1078 } 1079 1080 spin_unlock(&queue->rx_lock); 1081 1082 return work_done; 1083 } 1084 1085 static int xennet_change_mtu(struct net_device *dev, int mtu) 1086 { 1087 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1088 1089 if (mtu > max) 1090 return -EINVAL; 1091 dev->mtu = mtu; 1092 return 0; 1093 } 1094 1095 static void xennet_get_stats64(struct net_device *dev, 1096 struct rtnl_link_stats64 *tot) 1097 { 1098 struct netfront_info *np = netdev_priv(dev); 1099 int cpu; 1100 1101 for_each_possible_cpu(cpu) { 1102 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1103 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1104 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1105 unsigned int start; 1106 1107 do { 1108 start = u64_stats_fetch_begin_irq(&tx_stats->syncp); 1109 tx_packets = tx_stats->packets; 1110 tx_bytes = tx_stats->bytes; 1111 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); 1112 1113 do { 1114 start = u64_stats_fetch_begin_irq(&rx_stats->syncp); 1115 rx_packets = rx_stats->packets; 1116 rx_bytes = rx_stats->bytes; 1117 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); 1118 1119 tot->rx_packets += rx_packets; 1120 tot->tx_packets += tx_packets; 1121 tot->rx_bytes += rx_bytes; 1122 tot->tx_bytes += tx_bytes; 1123 } 1124 1125 tot->rx_errors = dev->stats.rx_errors; 1126 tot->tx_dropped = dev->stats.tx_dropped; 1127 } 1128 1129 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1130 { 1131 struct sk_buff *skb; 1132 int i; 1133 1134 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1135 /* Skip over entries which are actually freelist references */ 1136 if (skb_entry_is_link(&queue->tx_skbs[i])) 1137 continue; 1138 1139 skb = queue->tx_skbs[i].skb; 1140 get_page(queue->grant_tx_page[i]); 1141 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1142 GNTMAP_readonly, 1143 (unsigned long)page_address(queue->grant_tx_page[i])); 1144 queue->grant_tx_page[i] = NULL; 1145 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1146 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1147 dev_kfree_skb_irq(skb); 1148 } 1149 } 1150 1151 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1152 { 1153 int id, ref; 1154 1155 spin_lock_bh(&queue->rx_lock); 1156 1157 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1158 struct sk_buff *skb; 1159 struct page *page; 1160 1161 skb = queue->rx_skbs[id]; 1162 if (!skb) 1163 continue; 1164 1165 ref = queue->grant_rx_ref[id]; 1166 if (ref == GRANT_INVALID_REF) 1167 continue; 1168 1169 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1170 1171 /* gnttab_end_foreign_access() needs a page ref until 1172 * foreign access is ended (which may be deferred). 1173 */ 1174 get_page(page); 1175 gnttab_end_foreign_access(ref, 0, 1176 (unsigned long)page_address(page)); 1177 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1178 1179 kfree_skb(skb); 1180 } 1181 1182 spin_unlock_bh(&queue->rx_lock); 1183 } 1184 1185 static netdev_features_t xennet_fix_features(struct net_device *dev, 1186 netdev_features_t features) 1187 { 1188 struct netfront_info *np = netdev_priv(dev); 1189 1190 if (features & NETIF_F_SG && 1191 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) 1192 features &= ~NETIF_F_SG; 1193 1194 if (features & NETIF_F_IPV6_CSUM && 1195 !xenbus_read_unsigned(np->xbdev->otherend, 1196 "feature-ipv6-csum-offload", 0)) 1197 features &= ~NETIF_F_IPV6_CSUM; 1198 1199 if (features & NETIF_F_TSO && 1200 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) 1201 features &= ~NETIF_F_TSO; 1202 1203 if (features & NETIF_F_TSO6 && 1204 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) 1205 features &= ~NETIF_F_TSO6; 1206 1207 return features; 1208 } 1209 1210 static int xennet_set_features(struct net_device *dev, 1211 netdev_features_t features) 1212 { 1213 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1214 netdev_info(dev, "Reducing MTU because no SG offload"); 1215 dev->mtu = ETH_DATA_LEN; 1216 } 1217 1218 return 0; 1219 } 1220 1221 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1222 { 1223 struct netfront_queue *queue = dev_id; 1224 unsigned long flags; 1225 1226 spin_lock_irqsave(&queue->tx_lock, flags); 1227 xennet_tx_buf_gc(queue); 1228 spin_unlock_irqrestore(&queue->tx_lock, flags); 1229 1230 return IRQ_HANDLED; 1231 } 1232 1233 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1234 { 1235 struct netfront_queue *queue = dev_id; 1236 struct net_device *dev = queue->info->netdev; 1237 1238 if (likely(netif_carrier_ok(dev) && 1239 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1240 napi_schedule(&queue->napi); 1241 1242 return IRQ_HANDLED; 1243 } 1244 1245 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1246 { 1247 xennet_tx_interrupt(irq, dev_id); 1248 xennet_rx_interrupt(irq, dev_id); 1249 return IRQ_HANDLED; 1250 } 1251 1252 #ifdef CONFIG_NET_POLL_CONTROLLER 1253 static void xennet_poll_controller(struct net_device *dev) 1254 { 1255 /* Poll each queue */ 1256 struct netfront_info *info = netdev_priv(dev); 1257 unsigned int num_queues = dev->real_num_tx_queues; 1258 unsigned int i; 1259 for (i = 0; i < num_queues; ++i) 1260 xennet_interrupt(0, &info->queues[i]); 1261 } 1262 #endif 1263 1264 static const struct net_device_ops xennet_netdev_ops = { 1265 .ndo_open = xennet_open, 1266 .ndo_stop = xennet_close, 1267 .ndo_start_xmit = xennet_start_xmit, 1268 .ndo_change_mtu = xennet_change_mtu, 1269 .ndo_get_stats64 = xennet_get_stats64, 1270 .ndo_set_mac_address = eth_mac_addr, 1271 .ndo_validate_addr = eth_validate_addr, 1272 .ndo_fix_features = xennet_fix_features, 1273 .ndo_set_features = xennet_set_features, 1274 .ndo_select_queue = xennet_select_queue, 1275 #ifdef CONFIG_NET_POLL_CONTROLLER 1276 .ndo_poll_controller = xennet_poll_controller, 1277 #endif 1278 }; 1279 1280 static void xennet_free_netdev(struct net_device *netdev) 1281 { 1282 struct netfront_info *np = netdev_priv(netdev); 1283 1284 free_percpu(np->rx_stats); 1285 free_percpu(np->tx_stats); 1286 free_netdev(netdev); 1287 } 1288 1289 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1290 { 1291 int err; 1292 struct net_device *netdev; 1293 struct netfront_info *np; 1294 1295 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1296 if (!netdev) 1297 return ERR_PTR(-ENOMEM); 1298 1299 np = netdev_priv(netdev); 1300 np->xbdev = dev; 1301 1302 np->queues = NULL; 1303 1304 err = -ENOMEM; 1305 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1306 if (np->rx_stats == NULL) 1307 goto exit; 1308 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1309 if (np->tx_stats == NULL) 1310 goto exit; 1311 1312 netdev->netdev_ops = &xennet_netdev_ops; 1313 1314 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1315 NETIF_F_GSO_ROBUST; 1316 netdev->hw_features = NETIF_F_SG | 1317 NETIF_F_IPV6_CSUM | 1318 NETIF_F_TSO | NETIF_F_TSO6; 1319 1320 /* 1321 * Assume that all hw features are available for now. This set 1322 * will be adjusted by the call to netdev_update_features() in 1323 * xennet_connect() which is the earliest point where we can 1324 * negotiate with the backend regarding supported features. 1325 */ 1326 netdev->features |= netdev->hw_features; 1327 1328 netdev->ethtool_ops = &xennet_ethtool_ops; 1329 netdev->min_mtu = ETH_MIN_MTU; 1330 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; 1331 SET_NETDEV_DEV(netdev, &dev->dev); 1332 1333 np->netdev = netdev; 1334 1335 netif_carrier_off(netdev); 1336 1337 xenbus_switch_state(dev, XenbusStateInitialising); 1338 wait_event(module_wq, 1339 xenbus_read_driver_state(dev->otherend) != 1340 XenbusStateClosed && 1341 xenbus_read_driver_state(dev->otherend) != 1342 XenbusStateUnknown); 1343 return netdev; 1344 1345 exit: 1346 xennet_free_netdev(netdev); 1347 return ERR_PTR(err); 1348 } 1349 1350 /** 1351 * Entry point to this code when a new device is created. Allocate the basic 1352 * structures and the ring buffers for communication with the backend, and 1353 * inform the backend of the appropriate details for those. 1354 */ 1355 static int netfront_probe(struct xenbus_device *dev, 1356 const struct xenbus_device_id *id) 1357 { 1358 int err; 1359 struct net_device *netdev; 1360 struct netfront_info *info; 1361 1362 netdev = xennet_create_dev(dev); 1363 if (IS_ERR(netdev)) { 1364 err = PTR_ERR(netdev); 1365 xenbus_dev_fatal(dev, err, "creating netdev"); 1366 return err; 1367 } 1368 1369 info = netdev_priv(netdev); 1370 dev_set_drvdata(&dev->dev, info); 1371 #ifdef CONFIG_SYSFS 1372 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1373 #endif 1374 1375 return 0; 1376 } 1377 1378 static void xennet_end_access(int ref, void *page) 1379 { 1380 /* This frees the page as a side-effect */ 1381 if (ref != GRANT_INVALID_REF) 1382 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1383 } 1384 1385 static void xennet_disconnect_backend(struct netfront_info *info) 1386 { 1387 unsigned int i = 0; 1388 unsigned int num_queues = info->netdev->real_num_tx_queues; 1389 1390 netif_carrier_off(info->netdev); 1391 1392 for (i = 0; i < num_queues && info->queues; ++i) { 1393 struct netfront_queue *queue = &info->queues[i]; 1394 1395 del_timer_sync(&queue->rx_refill_timer); 1396 1397 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1398 unbind_from_irqhandler(queue->tx_irq, queue); 1399 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1400 unbind_from_irqhandler(queue->tx_irq, queue); 1401 unbind_from_irqhandler(queue->rx_irq, queue); 1402 } 1403 queue->tx_evtchn = queue->rx_evtchn = 0; 1404 queue->tx_irq = queue->rx_irq = 0; 1405 1406 if (netif_running(info->netdev)) 1407 napi_synchronize(&queue->napi); 1408 1409 xennet_release_tx_bufs(queue); 1410 xennet_release_rx_bufs(queue); 1411 gnttab_free_grant_references(queue->gref_tx_head); 1412 gnttab_free_grant_references(queue->gref_rx_head); 1413 1414 /* End access and free the pages */ 1415 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1416 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1417 1418 queue->tx_ring_ref = GRANT_INVALID_REF; 1419 queue->rx_ring_ref = GRANT_INVALID_REF; 1420 queue->tx.sring = NULL; 1421 queue->rx.sring = NULL; 1422 } 1423 } 1424 1425 /** 1426 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1427 * driver restart. We tear down our netif structure and recreate it, but 1428 * leave the device-layer structures intact so that this is transparent to the 1429 * rest of the kernel. 1430 */ 1431 static int netfront_resume(struct xenbus_device *dev) 1432 { 1433 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1434 1435 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1436 1437 xennet_disconnect_backend(info); 1438 return 0; 1439 } 1440 1441 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1442 { 1443 char *s, *e, *macstr; 1444 int i; 1445 1446 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1447 if (IS_ERR(macstr)) 1448 return PTR_ERR(macstr); 1449 1450 for (i = 0; i < ETH_ALEN; i++) { 1451 mac[i] = simple_strtoul(s, &e, 16); 1452 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1453 kfree(macstr); 1454 return -ENOENT; 1455 } 1456 s = e+1; 1457 } 1458 1459 kfree(macstr); 1460 return 0; 1461 } 1462 1463 static int setup_netfront_single(struct netfront_queue *queue) 1464 { 1465 int err; 1466 1467 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1468 if (err < 0) 1469 goto fail; 1470 1471 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1472 xennet_interrupt, 1473 0, queue->info->netdev->name, queue); 1474 if (err < 0) 1475 goto bind_fail; 1476 queue->rx_evtchn = queue->tx_evtchn; 1477 queue->rx_irq = queue->tx_irq = err; 1478 1479 return 0; 1480 1481 bind_fail: 1482 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1483 queue->tx_evtchn = 0; 1484 fail: 1485 return err; 1486 } 1487 1488 static int setup_netfront_split(struct netfront_queue *queue) 1489 { 1490 int err; 1491 1492 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1493 if (err < 0) 1494 goto fail; 1495 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1496 if (err < 0) 1497 goto alloc_rx_evtchn_fail; 1498 1499 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1500 "%s-tx", queue->name); 1501 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1502 xennet_tx_interrupt, 1503 0, queue->tx_irq_name, queue); 1504 if (err < 0) 1505 goto bind_tx_fail; 1506 queue->tx_irq = err; 1507 1508 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1509 "%s-rx", queue->name); 1510 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1511 xennet_rx_interrupt, 1512 0, queue->rx_irq_name, queue); 1513 if (err < 0) 1514 goto bind_rx_fail; 1515 queue->rx_irq = err; 1516 1517 return 0; 1518 1519 bind_rx_fail: 1520 unbind_from_irqhandler(queue->tx_irq, queue); 1521 queue->tx_irq = 0; 1522 bind_tx_fail: 1523 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1524 queue->rx_evtchn = 0; 1525 alloc_rx_evtchn_fail: 1526 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1527 queue->tx_evtchn = 0; 1528 fail: 1529 return err; 1530 } 1531 1532 static int setup_netfront(struct xenbus_device *dev, 1533 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1534 { 1535 struct xen_netif_tx_sring *txs; 1536 struct xen_netif_rx_sring *rxs; 1537 grant_ref_t gref; 1538 int err; 1539 1540 queue->tx_ring_ref = GRANT_INVALID_REF; 1541 queue->rx_ring_ref = GRANT_INVALID_REF; 1542 queue->rx.sring = NULL; 1543 queue->tx.sring = NULL; 1544 1545 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1546 if (!txs) { 1547 err = -ENOMEM; 1548 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1549 goto fail; 1550 } 1551 SHARED_RING_INIT(txs); 1552 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); 1553 1554 err = xenbus_grant_ring(dev, txs, 1, &gref); 1555 if (err < 0) 1556 goto grant_tx_ring_fail; 1557 queue->tx_ring_ref = gref; 1558 1559 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1560 if (!rxs) { 1561 err = -ENOMEM; 1562 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1563 goto alloc_rx_ring_fail; 1564 } 1565 SHARED_RING_INIT(rxs); 1566 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); 1567 1568 err = xenbus_grant_ring(dev, rxs, 1, &gref); 1569 if (err < 0) 1570 goto grant_rx_ring_fail; 1571 queue->rx_ring_ref = gref; 1572 1573 if (feature_split_evtchn) 1574 err = setup_netfront_split(queue); 1575 /* setup single event channel if 1576 * a) feature-split-event-channels == 0 1577 * b) feature-split-event-channels == 1 but failed to setup 1578 */ 1579 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1580 err = setup_netfront_single(queue); 1581 1582 if (err) 1583 goto alloc_evtchn_fail; 1584 1585 return 0; 1586 1587 /* If we fail to setup netfront, it is safe to just revoke access to 1588 * granted pages because backend is not accessing it at this point. 1589 */ 1590 alloc_evtchn_fail: 1591 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1592 grant_rx_ring_fail: 1593 free_page((unsigned long)rxs); 1594 alloc_rx_ring_fail: 1595 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1596 grant_tx_ring_fail: 1597 free_page((unsigned long)txs); 1598 fail: 1599 return err; 1600 } 1601 1602 /* Queue-specific initialisation 1603 * This used to be done in xennet_create_dev() but must now 1604 * be run per-queue. 1605 */ 1606 static int xennet_init_queue(struct netfront_queue *queue) 1607 { 1608 unsigned short i; 1609 int err = 0; 1610 char *devid; 1611 1612 spin_lock_init(&queue->tx_lock); 1613 spin_lock_init(&queue->rx_lock); 1614 1615 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); 1616 1617 devid = strrchr(queue->info->xbdev->nodename, '/') + 1; 1618 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u", 1619 devid, queue->id); 1620 1621 /* Initialise tx_skbs as a free chain containing every entry. */ 1622 queue->tx_skb_freelist = 0; 1623 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1624 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1625 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1626 queue->grant_tx_page[i] = NULL; 1627 } 1628 1629 /* Clear out rx_skbs */ 1630 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1631 queue->rx_skbs[i] = NULL; 1632 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1633 } 1634 1635 /* A grant for every tx ring slot */ 1636 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1637 &queue->gref_tx_head) < 0) { 1638 pr_alert("can't alloc tx grant refs\n"); 1639 err = -ENOMEM; 1640 goto exit; 1641 } 1642 1643 /* A grant for every rx ring slot */ 1644 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1645 &queue->gref_rx_head) < 0) { 1646 pr_alert("can't alloc rx grant refs\n"); 1647 err = -ENOMEM; 1648 goto exit_free_tx; 1649 } 1650 1651 return 0; 1652 1653 exit_free_tx: 1654 gnttab_free_grant_references(queue->gref_tx_head); 1655 exit: 1656 return err; 1657 } 1658 1659 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1660 struct xenbus_transaction *xbt, int write_hierarchical) 1661 { 1662 /* Write the queue-specific keys into XenStore in the traditional 1663 * way for a single queue, or in a queue subkeys for multiple 1664 * queues. 1665 */ 1666 struct xenbus_device *dev = queue->info->xbdev; 1667 int err; 1668 const char *message; 1669 char *path; 1670 size_t pathsize; 1671 1672 /* Choose the correct place to write the keys */ 1673 if (write_hierarchical) { 1674 pathsize = strlen(dev->nodename) + 10; 1675 path = kzalloc(pathsize, GFP_KERNEL); 1676 if (!path) { 1677 err = -ENOMEM; 1678 message = "out of memory while writing ring references"; 1679 goto error; 1680 } 1681 snprintf(path, pathsize, "%s/queue-%u", 1682 dev->nodename, queue->id); 1683 } else { 1684 path = (char *)dev->nodename; 1685 } 1686 1687 /* Write ring references */ 1688 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1689 queue->tx_ring_ref); 1690 if (err) { 1691 message = "writing tx-ring-ref"; 1692 goto error; 1693 } 1694 1695 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1696 queue->rx_ring_ref); 1697 if (err) { 1698 message = "writing rx-ring-ref"; 1699 goto error; 1700 } 1701 1702 /* Write event channels; taking into account both shared 1703 * and split event channel scenarios. 1704 */ 1705 if (queue->tx_evtchn == queue->rx_evtchn) { 1706 /* Shared event channel */ 1707 err = xenbus_printf(*xbt, path, 1708 "event-channel", "%u", queue->tx_evtchn); 1709 if (err) { 1710 message = "writing event-channel"; 1711 goto error; 1712 } 1713 } else { 1714 /* Split event channels */ 1715 err = xenbus_printf(*xbt, path, 1716 "event-channel-tx", "%u", queue->tx_evtchn); 1717 if (err) { 1718 message = "writing event-channel-tx"; 1719 goto error; 1720 } 1721 1722 err = xenbus_printf(*xbt, path, 1723 "event-channel-rx", "%u", queue->rx_evtchn); 1724 if (err) { 1725 message = "writing event-channel-rx"; 1726 goto error; 1727 } 1728 } 1729 1730 if (write_hierarchical) 1731 kfree(path); 1732 return 0; 1733 1734 error: 1735 if (write_hierarchical) 1736 kfree(path); 1737 xenbus_dev_fatal(dev, err, "%s", message); 1738 return err; 1739 } 1740 1741 static void xennet_destroy_queues(struct netfront_info *info) 1742 { 1743 unsigned int i; 1744 1745 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1746 struct netfront_queue *queue = &info->queues[i]; 1747 1748 if (netif_running(info->netdev)) 1749 napi_disable(&queue->napi); 1750 netif_napi_del(&queue->napi); 1751 } 1752 1753 kfree(info->queues); 1754 info->queues = NULL; 1755 } 1756 1757 static int xennet_create_queues(struct netfront_info *info, 1758 unsigned int *num_queues) 1759 { 1760 unsigned int i; 1761 int ret; 1762 1763 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), 1764 GFP_KERNEL); 1765 if (!info->queues) 1766 return -ENOMEM; 1767 1768 for (i = 0; i < *num_queues; i++) { 1769 struct netfront_queue *queue = &info->queues[i]; 1770 1771 queue->id = i; 1772 queue->info = info; 1773 1774 ret = xennet_init_queue(queue); 1775 if (ret < 0) { 1776 dev_warn(&info->xbdev->dev, 1777 "only created %d queues\n", i); 1778 *num_queues = i; 1779 break; 1780 } 1781 1782 netif_napi_add(queue->info->netdev, &queue->napi, 1783 xennet_poll, 64); 1784 if (netif_running(info->netdev)) 1785 napi_enable(&queue->napi); 1786 } 1787 1788 netif_set_real_num_tx_queues(info->netdev, *num_queues); 1789 1790 if (*num_queues == 0) { 1791 dev_err(&info->xbdev->dev, "no queues\n"); 1792 return -EINVAL; 1793 } 1794 return 0; 1795 } 1796 1797 /* Common code used when first setting up, and when resuming. */ 1798 static int talk_to_netback(struct xenbus_device *dev, 1799 struct netfront_info *info) 1800 { 1801 const char *message; 1802 struct xenbus_transaction xbt; 1803 int err; 1804 unsigned int feature_split_evtchn; 1805 unsigned int i = 0; 1806 unsigned int max_queues = 0; 1807 struct netfront_queue *queue = NULL; 1808 unsigned int num_queues = 1; 1809 1810 info->netdev->irq = 0; 1811 1812 /* Check if backend supports multiple queues */ 1813 max_queues = xenbus_read_unsigned(info->xbdev->otherend, 1814 "multi-queue-max-queues", 1); 1815 num_queues = min(max_queues, xennet_max_queues); 1816 1817 /* Check feature-split-event-channels */ 1818 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, 1819 "feature-split-event-channels", 0); 1820 1821 /* Read mac addr. */ 1822 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1823 if (err) { 1824 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1825 goto out_unlocked; 1826 } 1827 1828 rtnl_lock(); 1829 if (info->queues) 1830 xennet_destroy_queues(info); 1831 1832 err = xennet_create_queues(info, &num_queues); 1833 if (err < 0) { 1834 xenbus_dev_fatal(dev, err, "creating queues"); 1835 kfree(info->queues); 1836 info->queues = NULL; 1837 goto out; 1838 } 1839 rtnl_unlock(); 1840 1841 /* Create shared ring, alloc event channel -- for each queue */ 1842 for (i = 0; i < num_queues; ++i) { 1843 queue = &info->queues[i]; 1844 err = setup_netfront(dev, queue, feature_split_evtchn); 1845 if (err) 1846 goto destroy_ring; 1847 } 1848 1849 again: 1850 err = xenbus_transaction_start(&xbt); 1851 if (err) { 1852 xenbus_dev_fatal(dev, err, "starting transaction"); 1853 goto destroy_ring; 1854 } 1855 1856 if (xenbus_exists(XBT_NIL, 1857 info->xbdev->otherend, "multi-queue-max-queues")) { 1858 /* Write the number of queues */ 1859 err = xenbus_printf(xbt, dev->nodename, 1860 "multi-queue-num-queues", "%u", num_queues); 1861 if (err) { 1862 message = "writing multi-queue-num-queues"; 1863 goto abort_transaction_no_dev_fatal; 1864 } 1865 } 1866 1867 if (num_queues == 1) { 1868 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1869 if (err) 1870 goto abort_transaction_no_dev_fatal; 1871 } else { 1872 /* Write the keys for each queue */ 1873 for (i = 0; i < num_queues; ++i) { 1874 queue = &info->queues[i]; 1875 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1876 if (err) 1877 goto abort_transaction_no_dev_fatal; 1878 } 1879 } 1880 1881 /* The remaining keys are not queue-specific */ 1882 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1883 1); 1884 if (err) { 1885 message = "writing request-rx-copy"; 1886 goto abort_transaction; 1887 } 1888 1889 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1890 if (err) { 1891 message = "writing feature-rx-notify"; 1892 goto abort_transaction; 1893 } 1894 1895 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1896 if (err) { 1897 message = "writing feature-sg"; 1898 goto abort_transaction; 1899 } 1900 1901 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1902 if (err) { 1903 message = "writing feature-gso-tcpv4"; 1904 goto abort_transaction; 1905 } 1906 1907 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1908 if (err) { 1909 message = "writing feature-gso-tcpv6"; 1910 goto abort_transaction; 1911 } 1912 1913 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1914 "1"); 1915 if (err) { 1916 message = "writing feature-ipv6-csum-offload"; 1917 goto abort_transaction; 1918 } 1919 1920 err = xenbus_transaction_end(xbt, 0); 1921 if (err) { 1922 if (err == -EAGAIN) 1923 goto again; 1924 xenbus_dev_fatal(dev, err, "completing transaction"); 1925 goto destroy_ring; 1926 } 1927 1928 return 0; 1929 1930 abort_transaction: 1931 xenbus_dev_fatal(dev, err, "%s", message); 1932 abort_transaction_no_dev_fatal: 1933 xenbus_transaction_end(xbt, 1); 1934 destroy_ring: 1935 xennet_disconnect_backend(info); 1936 rtnl_lock(); 1937 xennet_destroy_queues(info); 1938 out: 1939 rtnl_unlock(); 1940 out_unlocked: 1941 device_unregister(&dev->dev); 1942 return err; 1943 } 1944 1945 static int xennet_connect(struct net_device *dev) 1946 { 1947 struct netfront_info *np = netdev_priv(dev); 1948 unsigned int num_queues = 0; 1949 int err; 1950 unsigned int j = 0; 1951 struct netfront_queue *queue = NULL; 1952 1953 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { 1954 dev_info(&dev->dev, 1955 "backend does not support copying receive path\n"); 1956 return -ENODEV; 1957 } 1958 1959 err = talk_to_netback(np->xbdev, np); 1960 if (err) 1961 return err; 1962 1963 /* talk_to_netback() sets the correct number of queues */ 1964 num_queues = dev->real_num_tx_queues; 1965 1966 if (dev->reg_state == NETREG_UNINITIALIZED) { 1967 err = register_netdev(dev); 1968 if (err) { 1969 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1970 device_unregister(&np->xbdev->dev); 1971 return err; 1972 } 1973 } 1974 1975 rtnl_lock(); 1976 netdev_update_features(dev); 1977 rtnl_unlock(); 1978 1979 /* 1980 * All public and private state should now be sane. Get 1981 * ready to start sending and receiving packets and give the driver 1982 * domain a kick because we've probably just requeued some 1983 * packets. 1984 */ 1985 netif_carrier_on(np->netdev); 1986 for (j = 0; j < num_queues; ++j) { 1987 queue = &np->queues[j]; 1988 1989 notify_remote_via_irq(queue->tx_irq); 1990 if (queue->tx_irq != queue->rx_irq) 1991 notify_remote_via_irq(queue->rx_irq); 1992 1993 spin_lock_irq(&queue->tx_lock); 1994 xennet_tx_buf_gc(queue); 1995 spin_unlock_irq(&queue->tx_lock); 1996 1997 spin_lock_bh(&queue->rx_lock); 1998 xennet_alloc_rx_buffers(queue); 1999 spin_unlock_bh(&queue->rx_lock); 2000 } 2001 2002 return 0; 2003 } 2004 2005 /** 2006 * Callback received when the backend's state changes. 2007 */ 2008 static void netback_changed(struct xenbus_device *dev, 2009 enum xenbus_state backend_state) 2010 { 2011 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2012 struct net_device *netdev = np->netdev; 2013 2014 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2015 2016 wake_up_all(&module_wq); 2017 2018 switch (backend_state) { 2019 case XenbusStateInitialising: 2020 case XenbusStateInitialised: 2021 case XenbusStateReconfiguring: 2022 case XenbusStateReconfigured: 2023 case XenbusStateUnknown: 2024 break; 2025 2026 case XenbusStateInitWait: 2027 if (dev->state != XenbusStateInitialising) 2028 break; 2029 if (xennet_connect(netdev) != 0) 2030 break; 2031 xenbus_switch_state(dev, XenbusStateConnected); 2032 break; 2033 2034 case XenbusStateConnected: 2035 netdev_notify_peers(netdev); 2036 break; 2037 2038 case XenbusStateClosed: 2039 if (dev->state == XenbusStateClosed) 2040 break; 2041 /* Missed the backend's CLOSING state -- fallthrough */ 2042 case XenbusStateClosing: 2043 xenbus_frontend_closed(dev); 2044 break; 2045 } 2046 } 2047 2048 static const struct xennet_stat { 2049 char name[ETH_GSTRING_LEN]; 2050 u16 offset; 2051 } xennet_stats[] = { 2052 { 2053 "rx_gso_checksum_fixup", 2054 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2055 }, 2056 }; 2057 2058 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2059 { 2060 switch (string_set) { 2061 case ETH_SS_STATS: 2062 return ARRAY_SIZE(xennet_stats); 2063 default: 2064 return -EINVAL; 2065 } 2066 } 2067 2068 static void xennet_get_ethtool_stats(struct net_device *dev, 2069 struct ethtool_stats *stats, u64 * data) 2070 { 2071 void *np = netdev_priv(dev); 2072 int i; 2073 2074 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2075 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2076 } 2077 2078 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2079 { 2080 int i; 2081 2082 switch (stringset) { 2083 case ETH_SS_STATS: 2084 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2085 memcpy(data + i * ETH_GSTRING_LEN, 2086 xennet_stats[i].name, ETH_GSTRING_LEN); 2087 break; 2088 } 2089 } 2090 2091 static const struct ethtool_ops xennet_ethtool_ops = 2092 { 2093 .get_link = ethtool_op_get_link, 2094 2095 .get_sset_count = xennet_get_sset_count, 2096 .get_ethtool_stats = xennet_get_ethtool_stats, 2097 .get_strings = xennet_get_strings, 2098 }; 2099 2100 #ifdef CONFIG_SYSFS 2101 static ssize_t show_rxbuf(struct device *dev, 2102 struct device_attribute *attr, char *buf) 2103 { 2104 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2105 } 2106 2107 static ssize_t store_rxbuf(struct device *dev, 2108 struct device_attribute *attr, 2109 const char *buf, size_t len) 2110 { 2111 char *endp; 2112 unsigned long target; 2113 2114 if (!capable(CAP_NET_ADMIN)) 2115 return -EPERM; 2116 2117 target = simple_strtoul(buf, &endp, 0); 2118 if (endp == buf) 2119 return -EBADMSG; 2120 2121 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2122 2123 return len; 2124 } 2125 2126 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf); 2127 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf); 2128 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL); 2129 2130 static struct attribute *xennet_dev_attrs[] = { 2131 &dev_attr_rxbuf_min.attr, 2132 &dev_attr_rxbuf_max.attr, 2133 &dev_attr_rxbuf_cur.attr, 2134 NULL 2135 }; 2136 2137 static const struct attribute_group xennet_dev_group = { 2138 .attrs = xennet_dev_attrs 2139 }; 2140 #endif /* CONFIG_SYSFS */ 2141 2142 static int xennet_remove(struct xenbus_device *dev) 2143 { 2144 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2145 2146 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2147 2148 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) { 2149 xenbus_switch_state(dev, XenbusStateClosing); 2150 wait_event(module_wq, 2151 xenbus_read_driver_state(dev->otherend) == 2152 XenbusStateClosing || 2153 xenbus_read_driver_state(dev->otherend) == 2154 XenbusStateUnknown); 2155 2156 xenbus_switch_state(dev, XenbusStateClosed); 2157 wait_event(module_wq, 2158 xenbus_read_driver_state(dev->otherend) == 2159 XenbusStateClosed || 2160 xenbus_read_driver_state(dev->otherend) == 2161 XenbusStateUnknown); 2162 } 2163 2164 xennet_disconnect_backend(info); 2165 2166 if (info->netdev->reg_state == NETREG_REGISTERED) 2167 unregister_netdev(info->netdev); 2168 2169 if (info->queues) { 2170 rtnl_lock(); 2171 xennet_destroy_queues(info); 2172 rtnl_unlock(); 2173 } 2174 xennet_free_netdev(info->netdev); 2175 2176 return 0; 2177 } 2178 2179 static const struct xenbus_device_id netfront_ids[] = { 2180 { "vif" }, 2181 { "" } 2182 }; 2183 2184 static struct xenbus_driver netfront_driver = { 2185 .ids = netfront_ids, 2186 .probe = netfront_probe, 2187 .remove = xennet_remove, 2188 .resume = netfront_resume, 2189 .otherend_changed = netback_changed, 2190 }; 2191 2192 static int __init netif_init(void) 2193 { 2194 if (!xen_domain()) 2195 return -ENODEV; 2196 2197 if (!xen_has_pv_nic_devices()) 2198 return -ENODEV; 2199 2200 pr_info("Initialising Xen virtual ethernet driver\n"); 2201 2202 /* Allow as many queues as there are CPUs inut max. 8 if user has not 2203 * specified a value. 2204 */ 2205 if (xennet_max_queues == 0) 2206 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, 2207 num_online_cpus()); 2208 2209 return xenbus_register_frontend(&netfront_driver); 2210 } 2211 module_init(netif_init); 2212 2213 2214 static void __exit netif_exit(void) 2215 { 2216 xenbus_unregister_driver(&netfront_driver); 2217 } 2218 module_exit(netif_exit); 2219 2220 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2221 MODULE_LICENSE("GPL"); 2222 MODULE_ALIAS("xen:vif"); 2223 MODULE_ALIAS("xennet"); 2224