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