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