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