1 /* 2 * Virtual network driver for conversing with remote driver backends. 3 * 4 * Copyright (c) 2002-2005, K A Fraser 5 * Copyright (c) 2005, XenSource Ltd 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 2 9 * as published by the Free Software Foundation; or, when distributed 10 * separately from the Linux kernel or incorporated into other 11 * software packages, subject to the following license: 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this source file (the "Software"), to deal in the Software without 15 * restriction, including without limitation the rights to use, copy, modify, 16 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, subject to 18 * the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29 * IN THE SOFTWARE. 30 */ 31 32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 34 #include <linux/module.h> 35 #include <linux/kernel.h> 36 #include <linux/netdevice.h> 37 #include <linux/etherdevice.h> 38 #include <linux/skbuff.h> 39 #include <linux/ethtool.h> 40 #include <linux/if_ether.h> 41 #include <net/tcp.h> 42 #include <linux/udp.h> 43 #include <linux/moduleparam.h> 44 #include <linux/mm.h> 45 #include <linux/slab.h> 46 #include <net/ip.h> 47 48 #include <xen/xen.h> 49 #include <xen/xenbus.h> 50 #include <xen/events.h> 51 #include <xen/page.h> 52 #include <xen/platform_pci.h> 53 #include <xen/grant_table.h> 54 55 #include <xen/interface/io/netif.h> 56 #include <xen/interface/memory.h> 57 #include <xen/interface/grant_table.h> 58 59 /* Module parameters */ 60 #define MAX_QUEUES_DEFAULT 8 61 static unsigned int xennet_max_queues; 62 module_param_named(max_queues, xennet_max_queues, uint, 0644); 63 MODULE_PARM_DESC(max_queues, 64 "Maximum number of queues per virtual interface"); 65 66 #define XENNET_TIMEOUT (5 * HZ) 67 68 static const struct ethtool_ops xennet_ethtool_ops; 69 70 struct netfront_cb { 71 int pull_to; 72 }; 73 74 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 75 76 #define RX_COPY_THRESHOLD 256 77 78 #define GRANT_INVALID_REF 0 79 80 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE) 81 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE) 82 83 /* Minimum number of Rx slots (includes slot for GSO metadata). */ 84 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1) 85 86 /* Queue name is interface name with "-qNNN" appended */ 87 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6) 88 89 /* IRQ name is queue name with "-tx" or "-rx" appended */ 90 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) 91 92 static DECLARE_WAIT_QUEUE_HEAD(module_wq); 93 94 struct netfront_stats { 95 u64 packets; 96 u64 bytes; 97 struct u64_stats_sync syncp; 98 }; 99 100 struct netfront_info; 101 102 struct netfront_queue { 103 unsigned int id; /* Queue ID, 0-based */ 104 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ 105 struct netfront_info *info; 106 107 struct napi_struct napi; 108 109 /* Split event channels support, tx_* == rx_* when using 110 * single event channel. 111 */ 112 unsigned int tx_evtchn, rx_evtchn; 113 unsigned int tx_irq, rx_irq; 114 /* Only used when split event channels support is enabled */ 115 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ 116 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ 117 118 spinlock_t tx_lock; 119 struct xen_netif_tx_front_ring tx; 120 int tx_ring_ref; 121 122 /* 123 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 124 * are linked from tx_skb_freelist through skb_entry.link. 125 * 126 * NB. Freelist index entries are always going to be less than 127 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 128 * greater than PAGE_OFFSET: we use this property to distinguish 129 * them. 130 */ 131 union skb_entry { 132 struct sk_buff *skb; 133 unsigned long link; 134 } tx_skbs[NET_TX_RING_SIZE]; 135 grant_ref_t gref_tx_head; 136 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 137 struct page *grant_tx_page[NET_TX_RING_SIZE]; 138 unsigned tx_skb_freelist; 139 140 spinlock_t rx_lock ____cacheline_aligned_in_smp; 141 struct xen_netif_rx_front_ring rx; 142 int rx_ring_ref; 143 144 struct timer_list rx_refill_timer; 145 146 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 147 grant_ref_t gref_rx_head; 148 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 149 }; 150 151 struct netfront_info { 152 struct list_head list; 153 struct net_device *netdev; 154 155 struct xenbus_device *xbdev; 156 157 /* Multi-queue support */ 158 struct netfront_queue *queues; 159 160 /* Statistics */ 161 struct netfront_stats __percpu *rx_stats; 162 struct netfront_stats __percpu *tx_stats; 163 164 atomic_t rx_gso_checksum_fixup; 165 }; 166 167 struct netfront_rx_info { 168 struct xen_netif_rx_response rx; 169 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 170 }; 171 172 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 173 { 174 list->link = id; 175 } 176 177 static int skb_entry_is_link(const union skb_entry *list) 178 { 179 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 180 return (unsigned long)list->skb < PAGE_OFFSET; 181 } 182 183 /* 184 * Access macros for acquiring freeing slots in tx_skbs[]. 185 */ 186 187 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 188 unsigned short id) 189 { 190 skb_entry_set_link(&list[id], *head); 191 *head = id; 192 } 193 194 static unsigned short get_id_from_freelist(unsigned *head, 195 union skb_entry *list) 196 { 197 unsigned int id = *head; 198 *head = list[id].link; 199 return id; 200 } 201 202 static int xennet_rxidx(RING_IDX idx) 203 { 204 return idx & (NET_RX_RING_SIZE - 1); 205 } 206 207 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, 208 RING_IDX ri) 209 { 210 int i = xennet_rxidx(ri); 211 struct sk_buff *skb = queue->rx_skbs[i]; 212 queue->rx_skbs[i] = NULL; 213 return skb; 214 } 215 216 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, 217 RING_IDX ri) 218 { 219 int i = xennet_rxidx(ri); 220 grant_ref_t ref = queue->grant_rx_ref[i]; 221 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 222 return ref; 223 } 224 225 #ifdef CONFIG_SYSFS 226 static const struct attribute_group xennet_dev_group; 227 #endif 228 229 static bool xennet_can_sg(struct net_device *dev) 230 { 231 return dev->features & NETIF_F_SG; 232 } 233 234 235 static void rx_refill_timeout(struct timer_list *t) 236 { 237 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer); 238 napi_schedule(&queue->napi); 239 } 240 241 static int netfront_tx_slot_available(struct netfront_queue *queue) 242 { 243 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < 244 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1); 245 } 246 247 static void xennet_maybe_wake_tx(struct netfront_queue *queue) 248 { 249 struct net_device *dev = queue->info->netdev; 250 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); 251 252 if (unlikely(netif_tx_queue_stopped(dev_queue)) && 253 netfront_tx_slot_available(queue) && 254 likely(netif_running(dev))) 255 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); 256 } 257 258 259 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue) 260 { 261 struct sk_buff *skb; 262 struct page *page; 263 264 skb = __netdev_alloc_skb(queue->info->netdev, 265 RX_COPY_THRESHOLD + NET_IP_ALIGN, 266 GFP_ATOMIC | __GFP_NOWARN); 267 if (unlikely(!skb)) 268 return NULL; 269 270 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 271 if (!page) { 272 kfree_skb(skb); 273 return NULL; 274 } 275 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 276 277 /* Align ip header to a 16 bytes boundary */ 278 skb_reserve(skb, NET_IP_ALIGN); 279 skb->dev = queue->info->netdev; 280 281 return skb; 282 } 283 284 285 static void xennet_alloc_rx_buffers(struct netfront_queue *queue) 286 { 287 RING_IDX req_prod = queue->rx.req_prod_pvt; 288 int notify; 289 int err = 0; 290 291 if (unlikely(!netif_carrier_ok(queue->info->netdev))) 292 return; 293 294 for (req_prod = queue->rx.req_prod_pvt; 295 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE; 296 req_prod++) { 297 struct sk_buff *skb; 298 unsigned short id; 299 grant_ref_t ref; 300 struct page *page; 301 struct xen_netif_rx_request *req; 302 303 skb = xennet_alloc_one_rx_buffer(queue); 304 if (!skb) { 305 err = -ENOMEM; 306 break; 307 } 308 309 id = xennet_rxidx(req_prod); 310 311 BUG_ON(queue->rx_skbs[id]); 312 queue->rx_skbs[id] = skb; 313 314 ref = gnttab_claim_grant_reference(&queue->gref_rx_head); 315 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 316 queue->grant_rx_ref[id] = ref; 317 318 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 319 320 req = RING_GET_REQUEST(&queue->rx, req_prod); 321 gnttab_page_grant_foreign_access_ref_one(ref, 322 queue->info->xbdev->otherend_id, 323 page, 324 0); 325 req->id = id; 326 req->gref = ref; 327 } 328 329 queue->rx.req_prod_pvt = req_prod; 330 331 /* Try again later if there are not enough requests or skb allocation 332 * failed. 333 * Enough requests is quantified as the sum of newly created slots and 334 * the unconsumed slots at the backend. 335 */ 336 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN || 337 unlikely(err)) { 338 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); 339 return; 340 } 341 342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 343 if (notify) 344 notify_remote_via_irq(queue->rx_irq); 345 } 346 347 static int xennet_open(struct net_device *dev) 348 { 349 struct netfront_info *np = netdev_priv(dev); 350 unsigned int num_queues = dev->real_num_tx_queues; 351 unsigned int i = 0; 352 struct netfront_queue *queue = NULL; 353 354 if (!np->queues) 355 return -ENODEV; 356 357 for (i = 0; i < num_queues; ++i) { 358 queue = &np->queues[i]; 359 napi_enable(&queue->napi); 360 361 spin_lock_bh(&queue->rx_lock); 362 if (netif_carrier_ok(dev)) { 363 xennet_alloc_rx_buffers(queue); 364 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 365 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 366 napi_schedule(&queue->napi); 367 } 368 spin_unlock_bh(&queue->rx_lock); 369 } 370 371 netif_tx_start_all_queues(dev); 372 373 return 0; 374 } 375 376 static void xennet_tx_buf_gc(struct netfront_queue *queue) 377 { 378 RING_IDX cons, prod; 379 unsigned short id; 380 struct sk_buff *skb; 381 bool more_to_do; 382 383 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 384 385 do { 386 prod = queue->tx.sring->rsp_prod; 387 rmb(); /* Ensure we see responses up to 'rp'. */ 388 389 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 390 struct xen_netif_tx_response *txrsp; 391 392 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 393 if (txrsp->status == XEN_NETIF_RSP_NULL) 394 continue; 395 396 id = txrsp->id; 397 skb = queue->tx_skbs[id].skb; 398 if (unlikely(gnttab_query_foreign_access( 399 queue->grant_tx_ref[id]) != 0)) { 400 pr_alert("%s: warning -- grant still in use by backend domain\n", 401 __func__); 402 BUG(); 403 } 404 gnttab_end_foreign_access_ref( 405 queue->grant_tx_ref[id], GNTMAP_readonly); 406 gnttab_release_grant_reference( 407 &queue->gref_tx_head, queue->grant_tx_ref[id]); 408 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 409 queue->grant_tx_page[id] = NULL; 410 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 411 dev_kfree_skb_irq(skb); 412 } 413 414 queue->tx.rsp_cons = prod; 415 416 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); 417 } while (more_to_do); 418 419 xennet_maybe_wake_tx(queue); 420 } 421 422 struct xennet_gnttab_make_txreq { 423 struct netfront_queue *queue; 424 struct sk_buff *skb; 425 struct page *page; 426 struct xen_netif_tx_request *tx; /* Last request */ 427 unsigned int size; 428 }; 429 430 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, 431 unsigned int len, void *data) 432 { 433 struct xennet_gnttab_make_txreq *info = data; 434 unsigned int id; 435 struct xen_netif_tx_request *tx; 436 grant_ref_t ref; 437 /* convenient aliases */ 438 struct page *page = info->page; 439 struct netfront_queue *queue = info->queue; 440 struct sk_buff *skb = info->skb; 441 442 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 443 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 444 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 445 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 446 447 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 448 gfn, GNTMAP_readonly); 449 450 queue->tx_skbs[id].skb = skb; 451 queue->grant_tx_page[id] = page; 452 queue->grant_tx_ref[id] = ref; 453 454 tx->id = id; 455 tx->gref = ref; 456 tx->offset = offset; 457 tx->size = len; 458 tx->flags = 0; 459 460 info->tx = tx; 461 info->size += tx->size; 462 } 463 464 static struct xen_netif_tx_request *xennet_make_first_txreq( 465 struct netfront_queue *queue, struct sk_buff *skb, 466 struct page *page, unsigned int offset, unsigned int len) 467 { 468 struct xennet_gnttab_make_txreq info = { 469 .queue = queue, 470 .skb = skb, 471 .page = page, 472 .size = 0, 473 }; 474 475 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info); 476 477 return info.tx; 478 } 479 480 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, 481 unsigned int len, void *data) 482 { 483 struct xennet_gnttab_make_txreq *info = data; 484 485 info->tx->flags |= XEN_NETTXF_more_data; 486 skb_get(info->skb); 487 xennet_tx_setup_grant(gfn, offset, len, data); 488 } 489 490 static struct xen_netif_tx_request *xennet_make_txreqs( 491 struct netfront_queue *queue, struct xen_netif_tx_request *tx, 492 struct sk_buff *skb, struct page *page, 493 unsigned int offset, unsigned int len) 494 { 495 struct xennet_gnttab_make_txreq info = { 496 .queue = queue, 497 .skb = skb, 498 .tx = tx, 499 }; 500 501 /* Skip unused frames from start of page */ 502 page += offset >> PAGE_SHIFT; 503 offset &= ~PAGE_MASK; 504 505 while (len) { 506 info.page = page; 507 info.size = 0; 508 509 gnttab_foreach_grant_in_range(page, offset, len, 510 xennet_make_one_txreq, 511 &info); 512 513 page++; 514 offset = 0; 515 len -= info.size; 516 } 517 518 return info.tx; 519 } 520 521 /* 522 * Count how many ring slots are required to send this skb. Each frag 523 * might be a compound page. 524 */ 525 static int xennet_count_skb_slots(struct sk_buff *skb) 526 { 527 int i, frags = skb_shinfo(skb)->nr_frags; 528 int slots; 529 530 slots = gnttab_count_grant(offset_in_page(skb->data), 531 skb_headlen(skb)); 532 533 for (i = 0; i < frags; i++) { 534 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 535 unsigned long size = skb_frag_size(frag); 536 unsigned long offset = skb_frag_off(frag); 537 538 /* Skip unused frames from start of page */ 539 offset &= ~PAGE_MASK; 540 541 slots += gnttab_count_grant(offset, size); 542 } 543 544 return slots; 545 } 546 547 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 548 struct net_device *sb_dev) 549 { 550 unsigned int num_queues = dev->real_num_tx_queues; 551 u32 hash; 552 u16 queue_idx; 553 554 /* First, check if there is only one queue */ 555 if (num_queues == 1) { 556 queue_idx = 0; 557 } else { 558 hash = skb_get_hash(skb); 559 queue_idx = hash % num_queues; 560 } 561 562 return queue_idx; 563 } 564 565 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) 566 567 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 568 { 569 struct netfront_info *np = netdev_priv(dev); 570 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 571 struct xen_netif_tx_request *tx, *first_tx; 572 unsigned int i; 573 int notify; 574 int slots; 575 struct page *page; 576 unsigned int offset; 577 unsigned int len; 578 unsigned long flags; 579 struct netfront_queue *queue = NULL; 580 unsigned int num_queues = dev->real_num_tx_queues; 581 u16 queue_index; 582 struct sk_buff *nskb; 583 584 /* Drop the packet if no queues are set up */ 585 if (num_queues < 1) 586 goto drop; 587 /* Determine which queue to transmit this SKB on */ 588 queue_index = skb_get_queue_mapping(skb); 589 queue = &np->queues[queue_index]; 590 591 /* If skb->len is too big for wire format, drop skb and alert 592 * user about misconfiguration. 593 */ 594 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 595 net_alert_ratelimited( 596 "xennet: skb->len = %u, too big for wire format\n", 597 skb->len); 598 goto drop; 599 } 600 601 slots = xennet_count_skb_slots(skb); 602 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { 603 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 604 slots, skb->len); 605 if (skb_linearize(skb)) 606 goto drop; 607 } 608 609 page = virt_to_page(skb->data); 610 offset = offset_in_page(skb->data); 611 612 /* The first req should be at least ETH_HLEN size or the packet will be 613 * dropped by netback. 614 */ 615 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { 616 nskb = skb_copy(skb, GFP_ATOMIC); 617 if (!nskb) 618 goto drop; 619 dev_consume_skb_any(skb); 620 skb = nskb; 621 page = virt_to_page(skb->data); 622 offset = offset_in_page(skb->data); 623 } 624 625 len = skb_headlen(skb); 626 627 spin_lock_irqsave(&queue->tx_lock, flags); 628 629 if (unlikely(!netif_carrier_ok(dev) || 630 (slots > 1 && !xennet_can_sg(dev)) || 631 netif_needs_gso(skb, netif_skb_features(skb)))) { 632 spin_unlock_irqrestore(&queue->tx_lock, flags); 633 goto drop; 634 } 635 636 /* First request for the linear area. */ 637 first_tx = tx = xennet_make_first_txreq(queue, skb, 638 page, offset, len); 639 offset += tx->size; 640 if (offset == PAGE_SIZE) { 641 page++; 642 offset = 0; 643 } 644 len -= tx->size; 645 646 if (skb->ip_summed == CHECKSUM_PARTIAL) 647 /* local packet? */ 648 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 649 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 650 /* remote but checksummed. */ 651 tx->flags |= XEN_NETTXF_data_validated; 652 653 /* Optional extra info after the first request. */ 654 if (skb_shinfo(skb)->gso_size) { 655 struct xen_netif_extra_info *gso; 656 657 gso = (struct xen_netif_extra_info *) 658 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 659 660 tx->flags |= XEN_NETTXF_extra_info; 661 662 gso->u.gso.size = skb_shinfo(skb)->gso_size; 663 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 664 XEN_NETIF_GSO_TYPE_TCPV6 : 665 XEN_NETIF_GSO_TYPE_TCPV4; 666 gso->u.gso.pad = 0; 667 gso->u.gso.features = 0; 668 669 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 670 gso->flags = 0; 671 } 672 673 /* Requests for the rest of the linear area. */ 674 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); 675 676 /* Requests for all the frags. */ 677 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 678 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 679 tx = xennet_make_txreqs(queue, tx, skb, skb_frag_page(frag), 680 skb_frag_off(frag), 681 skb_frag_size(frag)); 682 } 683 684 /* First request has the packet length. */ 685 first_tx->size = skb->len; 686 687 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 688 if (notify) 689 notify_remote_via_irq(queue->tx_irq); 690 691 u64_stats_update_begin(&tx_stats->syncp); 692 tx_stats->bytes += skb->len; 693 tx_stats->packets++; 694 u64_stats_update_end(&tx_stats->syncp); 695 696 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 697 xennet_tx_buf_gc(queue); 698 699 if (!netfront_tx_slot_available(queue)) 700 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 701 702 spin_unlock_irqrestore(&queue->tx_lock, flags); 703 704 return NETDEV_TX_OK; 705 706 drop: 707 dev->stats.tx_dropped++; 708 dev_kfree_skb_any(skb); 709 return NETDEV_TX_OK; 710 } 711 712 static int xennet_close(struct net_device *dev) 713 { 714 struct netfront_info *np = netdev_priv(dev); 715 unsigned int num_queues = dev->real_num_tx_queues; 716 unsigned int i; 717 struct netfront_queue *queue; 718 netif_tx_stop_all_queues(np->netdev); 719 for (i = 0; i < num_queues; ++i) { 720 queue = &np->queues[i]; 721 napi_disable(&queue->napi); 722 } 723 return 0; 724 } 725 726 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 727 grant_ref_t ref) 728 { 729 int new = xennet_rxidx(queue->rx.req_prod_pvt); 730 731 BUG_ON(queue->rx_skbs[new]); 732 queue->rx_skbs[new] = skb; 733 queue->grant_rx_ref[new] = ref; 734 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 735 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 736 queue->rx.req_prod_pvt++; 737 } 738 739 static int xennet_get_extras(struct netfront_queue *queue, 740 struct xen_netif_extra_info *extras, 741 RING_IDX rp) 742 743 { 744 struct xen_netif_extra_info *extra; 745 struct device *dev = &queue->info->netdev->dev; 746 RING_IDX cons = queue->rx.rsp_cons; 747 int err = 0; 748 749 do { 750 struct sk_buff *skb; 751 grant_ref_t ref; 752 753 if (unlikely(cons + 1 == rp)) { 754 if (net_ratelimit()) 755 dev_warn(dev, "Missing extra info\n"); 756 err = -EBADR; 757 break; 758 } 759 760 extra = (struct xen_netif_extra_info *) 761 RING_GET_RESPONSE(&queue->rx, ++cons); 762 763 if (unlikely(!extra->type || 764 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 765 if (net_ratelimit()) 766 dev_warn(dev, "Invalid extra type: %d\n", 767 extra->type); 768 err = -EINVAL; 769 } else { 770 memcpy(&extras[extra->type - 1], extra, 771 sizeof(*extra)); 772 } 773 774 skb = xennet_get_rx_skb(queue, cons); 775 ref = xennet_get_rx_ref(queue, cons); 776 xennet_move_rx_slot(queue, skb, ref); 777 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 778 779 queue->rx.rsp_cons = cons; 780 return err; 781 } 782 783 static int xennet_get_responses(struct netfront_queue *queue, 784 struct netfront_rx_info *rinfo, RING_IDX rp, 785 struct sk_buff_head *list) 786 { 787 struct xen_netif_rx_response *rx = &rinfo->rx; 788 struct xen_netif_extra_info *extras = rinfo->extras; 789 struct device *dev = &queue->info->netdev->dev; 790 RING_IDX cons = queue->rx.rsp_cons; 791 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 792 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 793 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD); 794 int slots = 1; 795 int err = 0; 796 unsigned long ret; 797 798 if (rx->flags & XEN_NETRXF_extra_info) { 799 err = xennet_get_extras(queue, extras, rp); 800 cons = queue->rx.rsp_cons; 801 } 802 803 for (;;) { 804 if (unlikely(rx->status < 0 || 805 rx->offset + rx->status > XEN_PAGE_SIZE)) { 806 if (net_ratelimit()) 807 dev_warn(dev, "rx->offset: %u, size: %d\n", 808 rx->offset, rx->status); 809 xennet_move_rx_slot(queue, skb, ref); 810 err = -EINVAL; 811 goto next; 812 } 813 814 /* 815 * This definitely indicates a bug, either in this driver or in 816 * the backend driver. In future this should flag the bad 817 * situation to the system controller to reboot the backend. 818 */ 819 if (ref == GRANT_INVALID_REF) { 820 if (net_ratelimit()) 821 dev_warn(dev, "Bad rx response id %d.\n", 822 rx->id); 823 err = -EINVAL; 824 goto next; 825 } 826 827 ret = gnttab_end_foreign_access_ref(ref, 0); 828 BUG_ON(!ret); 829 830 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 831 832 __skb_queue_tail(list, skb); 833 834 next: 835 if (!(rx->flags & XEN_NETRXF_more_data)) 836 break; 837 838 if (cons + slots == rp) { 839 if (net_ratelimit()) 840 dev_warn(dev, "Need more slots\n"); 841 err = -ENOENT; 842 break; 843 } 844 845 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 846 skb = xennet_get_rx_skb(queue, cons + slots); 847 ref = xennet_get_rx_ref(queue, cons + slots); 848 slots++; 849 } 850 851 if (unlikely(slots > max)) { 852 if (net_ratelimit()) 853 dev_warn(dev, "Too many slots\n"); 854 err = -E2BIG; 855 } 856 857 if (unlikely(err)) 858 queue->rx.rsp_cons = cons + slots; 859 860 return err; 861 } 862 863 static int xennet_set_skb_gso(struct sk_buff *skb, 864 struct xen_netif_extra_info *gso) 865 { 866 if (!gso->u.gso.size) { 867 if (net_ratelimit()) 868 pr_warn("GSO size must not be zero\n"); 869 return -EINVAL; 870 } 871 872 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 873 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 874 if (net_ratelimit()) 875 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 876 return -EINVAL; 877 } 878 879 skb_shinfo(skb)->gso_size = gso->u.gso.size; 880 skb_shinfo(skb)->gso_type = 881 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 882 SKB_GSO_TCPV4 : 883 SKB_GSO_TCPV6; 884 885 /* Header must be checked, and gso_segs computed. */ 886 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 887 skb_shinfo(skb)->gso_segs = 0; 888 889 return 0; 890 } 891 892 static int xennet_fill_frags(struct netfront_queue *queue, 893 struct sk_buff *skb, 894 struct sk_buff_head *list) 895 { 896 RING_IDX cons = queue->rx.rsp_cons; 897 struct sk_buff *nskb; 898 899 while ((nskb = __skb_dequeue(list))) { 900 struct xen_netif_rx_response *rx = 901 RING_GET_RESPONSE(&queue->rx, ++cons); 902 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 903 904 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { 905 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 906 907 BUG_ON(pull_to < skb_headlen(skb)); 908 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 909 } 910 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) { 911 queue->rx.rsp_cons = ++cons + skb_queue_len(list); 912 kfree_skb(nskb); 913 return -ENOENT; 914 } 915 916 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 917 skb_frag_page(nfrag), 918 rx->offset, rx->status, PAGE_SIZE); 919 920 skb_shinfo(nskb)->nr_frags = 0; 921 kfree_skb(nskb); 922 } 923 924 queue->rx.rsp_cons = cons; 925 926 return 0; 927 } 928 929 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 930 { 931 bool recalculate_partial_csum = false; 932 933 /* 934 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 935 * peers can fail to set NETRXF_csum_blank when sending a GSO 936 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 937 * recalculate the partial checksum. 938 */ 939 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 940 struct netfront_info *np = netdev_priv(dev); 941 atomic_inc(&np->rx_gso_checksum_fixup); 942 skb->ip_summed = CHECKSUM_PARTIAL; 943 recalculate_partial_csum = true; 944 } 945 946 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 947 if (skb->ip_summed != CHECKSUM_PARTIAL) 948 return 0; 949 950 return skb_checksum_setup(skb, recalculate_partial_csum); 951 } 952 953 static int handle_incoming_queue(struct netfront_queue *queue, 954 struct sk_buff_head *rxq) 955 { 956 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 957 int packets_dropped = 0; 958 struct sk_buff *skb; 959 960 while ((skb = __skb_dequeue(rxq)) != NULL) { 961 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 962 963 if (pull_to > skb_headlen(skb)) 964 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 965 966 /* Ethernet work: Delayed to here as it peeks the header. */ 967 skb->protocol = eth_type_trans(skb, queue->info->netdev); 968 skb_reset_network_header(skb); 969 970 if (checksum_setup(queue->info->netdev, skb)) { 971 kfree_skb(skb); 972 packets_dropped++; 973 queue->info->netdev->stats.rx_errors++; 974 continue; 975 } 976 977 u64_stats_update_begin(&rx_stats->syncp); 978 rx_stats->packets++; 979 rx_stats->bytes += skb->len; 980 u64_stats_update_end(&rx_stats->syncp); 981 982 /* Pass it up. */ 983 napi_gro_receive(&queue->napi, skb); 984 } 985 986 return packets_dropped; 987 } 988 989 static int xennet_poll(struct napi_struct *napi, int budget) 990 { 991 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 992 struct net_device *dev = queue->info->netdev; 993 struct sk_buff *skb; 994 struct netfront_rx_info rinfo; 995 struct xen_netif_rx_response *rx = &rinfo.rx; 996 struct xen_netif_extra_info *extras = rinfo.extras; 997 RING_IDX i, rp; 998 int work_done; 999 struct sk_buff_head rxq; 1000 struct sk_buff_head errq; 1001 struct sk_buff_head tmpq; 1002 int err; 1003 1004 spin_lock(&queue->rx_lock); 1005 1006 skb_queue_head_init(&rxq); 1007 skb_queue_head_init(&errq); 1008 skb_queue_head_init(&tmpq); 1009 1010 rp = queue->rx.sring->rsp_prod; 1011 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1012 1013 i = queue->rx.rsp_cons; 1014 work_done = 0; 1015 while ((i != rp) && (work_done < budget)) { 1016 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 1017 memset(extras, 0, sizeof(rinfo.extras)); 1018 1019 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 1020 1021 if (unlikely(err)) { 1022 err: 1023 while ((skb = __skb_dequeue(&tmpq))) 1024 __skb_queue_tail(&errq, skb); 1025 dev->stats.rx_errors++; 1026 i = queue->rx.rsp_cons; 1027 continue; 1028 } 1029 1030 skb = __skb_dequeue(&tmpq); 1031 1032 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1033 struct xen_netif_extra_info *gso; 1034 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1035 1036 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1037 __skb_queue_head(&tmpq, skb); 1038 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1039 goto err; 1040 } 1041 } 1042 1043 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1044 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1045 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1046 1047 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset); 1048 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1049 skb->data_len = rx->status; 1050 skb->len += rx->status; 1051 1052 if (unlikely(xennet_fill_frags(queue, skb, &tmpq))) 1053 goto err; 1054 1055 if (rx->flags & XEN_NETRXF_csum_blank) 1056 skb->ip_summed = CHECKSUM_PARTIAL; 1057 else if (rx->flags & XEN_NETRXF_data_validated) 1058 skb->ip_summed = CHECKSUM_UNNECESSARY; 1059 1060 __skb_queue_tail(&rxq, skb); 1061 1062 i = ++queue->rx.rsp_cons; 1063 work_done++; 1064 } 1065 1066 __skb_queue_purge(&errq); 1067 1068 work_done -= handle_incoming_queue(queue, &rxq); 1069 1070 xennet_alloc_rx_buffers(queue); 1071 1072 if (work_done < budget) { 1073 int more_to_do = 0; 1074 1075 napi_complete_done(napi, work_done); 1076 1077 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1078 if (more_to_do) 1079 napi_schedule(napi); 1080 } 1081 1082 spin_unlock(&queue->rx_lock); 1083 1084 return work_done; 1085 } 1086 1087 static int xennet_change_mtu(struct net_device *dev, int mtu) 1088 { 1089 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1090 1091 if (mtu > max) 1092 return -EINVAL; 1093 dev->mtu = mtu; 1094 return 0; 1095 } 1096 1097 static void xennet_get_stats64(struct net_device *dev, 1098 struct rtnl_link_stats64 *tot) 1099 { 1100 struct netfront_info *np = netdev_priv(dev); 1101 int cpu; 1102 1103 for_each_possible_cpu(cpu) { 1104 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1105 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1106 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1107 unsigned int start; 1108 1109 do { 1110 start = u64_stats_fetch_begin_irq(&tx_stats->syncp); 1111 tx_packets = tx_stats->packets; 1112 tx_bytes = tx_stats->bytes; 1113 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); 1114 1115 do { 1116 start = u64_stats_fetch_begin_irq(&rx_stats->syncp); 1117 rx_packets = rx_stats->packets; 1118 rx_bytes = rx_stats->bytes; 1119 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); 1120 1121 tot->rx_packets += rx_packets; 1122 tot->tx_packets += tx_packets; 1123 tot->rx_bytes += rx_bytes; 1124 tot->tx_bytes += tx_bytes; 1125 } 1126 1127 tot->rx_errors = dev->stats.rx_errors; 1128 tot->tx_dropped = dev->stats.tx_dropped; 1129 } 1130 1131 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1132 { 1133 struct sk_buff *skb; 1134 int i; 1135 1136 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1137 /* Skip over entries which are actually freelist references */ 1138 if (skb_entry_is_link(&queue->tx_skbs[i])) 1139 continue; 1140 1141 skb = queue->tx_skbs[i].skb; 1142 get_page(queue->grant_tx_page[i]); 1143 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1144 GNTMAP_readonly, 1145 (unsigned long)page_address(queue->grant_tx_page[i])); 1146 queue->grant_tx_page[i] = NULL; 1147 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1148 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1149 dev_kfree_skb_irq(skb); 1150 } 1151 } 1152 1153 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1154 { 1155 int id, ref; 1156 1157 spin_lock_bh(&queue->rx_lock); 1158 1159 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1160 struct sk_buff *skb; 1161 struct page *page; 1162 1163 skb = queue->rx_skbs[id]; 1164 if (!skb) 1165 continue; 1166 1167 ref = queue->grant_rx_ref[id]; 1168 if (ref == GRANT_INVALID_REF) 1169 continue; 1170 1171 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1172 1173 /* gnttab_end_foreign_access() needs a page ref until 1174 * foreign access is ended (which may be deferred). 1175 */ 1176 get_page(page); 1177 gnttab_end_foreign_access(ref, 0, 1178 (unsigned long)page_address(page)); 1179 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1180 1181 kfree_skb(skb); 1182 } 1183 1184 spin_unlock_bh(&queue->rx_lock); 1185 } 1186 1187 static netdev_features_t xennet_fix_features(struct net_device *dev, 1188 netdev_features_t features) 1189 { 1190 struct netfront_info *np = netdev_priv(dev); 1191 1192 if (features & NETIF_F_SG && 1193 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) 1194 features &= ~NETIF_F_SG; 1195 1196 if (features & NETIF_F_IPV6_CSUM && 1197 !xenbus_read_unsigned(np->xbdev->otherend, 1198 "feature-ipv6-csum-offload", 0)) 1199 features &= ~NETIF_F_IPV6_CSUM; 1200 1201 if (features & NETIF_F_TSO && 1202 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) 1203 features &= ~NETIF_F_TSO; 1204 1205 if (features & NETIF_F_TSO6 && 1206 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) 1207 features &= ~NETIF_F_TSO6; 1208 1209 return features; 1210 } 1211 1212 static int xennet_set_features(struct net_device *dev, 1213 netdev_features_t features) 1214 { 1215 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1216 netdev_info(dev, "Reducing MTU because no SG offload"); 1217 dev->mtu = ETH_DATA_LEN; 1218 } 1219 1220 return 0; 1221 } 1222 1223 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1224 { 1225 struct netfront_queue *queue = dev_id; 1226 unsigned long flags; 1227 1228 spin_lock_irqsave(&queue->tx_lock, flags); 1229 xennet_tx_buf_gc(queue); 1230 spin_unlock_irqrestore(&queue->tx_lock, flags); 1231 1232 return IRQ_HANDLED; 1233 } 1234 1235 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1236 { 1237 struct netfront_queue *queue = dev_id; 1238 struct net_device *dev = queue->info->netdev; 1239 1240 if (likely(netif_carrier_ok(dev) && 1241 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1242 napi_schedule(&queue->napi); 1243 1244 return IRQ_HANDLED; 1245 } 1246 1247 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1248 { 1249 xennet_tx_interrupt(irq, dev_id); 1250 xennet_rx_interrupt(irq, dev_id); 1251 return IRQ_HANDLED; 1252 } 1253 1254 #ifdef CONFIG_NET_POLL_CONTROLLER 1255 static void xennet_poll_controller(struct net_device *dev) 1256 { 1257 /* Poll each queue */ 1258 struct netfront_info *info = netdev_priv(dev); 1259 unsigned int num_queues = dev->real_num_tx_queues; 1260 unsigned int i; 1261 for (i = 0; i < num_queues; ++i) 1262 xennet_interrupt(0, &info->queues[i]); 1263 } 1264 #endif 1265 1266 static const struct net_device_ops xennet_netdev_ops = { 1267 .ndo_open = xennet_open, 1268 .ndo_stop = xennet_close, 1269 .ndo_start_xmit = xennet_start_xmit, 1270 .ndo_change_mtu = xennet_change_mtu, 1271 .ndo_get_stats64 = xennet_get_stats64, 1272 .ndo_set_mac_address = eth_mac_addr, 1273 .ndo_validate_addr = eth_validate_addr, 1274 .ndo_fix_features = xennet_fix_features, 1275 .ndo_set_features = xennet_set_features, 1276 .ndo_select_queue = xennet_select_queue, 1277 #ifdef CONFIG_NET_POLL_CONTROLLER 1278 .ndo_poll_controller = xennet_poll_controller, 1279 #endif 1280 }; 1281 1282 static void xennet_free_netdev(struct net_device *netdev) 1283 { 1284 struct netfront_info *np = netdev_priv(netdev); 1285 1286 free_percpu(np->rx_stats); 1287 free_percpu(np->tx_stats); 1288 free_netdev(netdev); 1289 } 1290 1291 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1292 { 1293 int err; 1294 struct net_device *netdev; 1295 struct netfront_info *np; 1296 1297 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1298 if (!netdev) 1299 return ERR_PTR(-ENOMEM); 1300 1301 np = netdev_priv(netdev); 1302 np->xbdev = dev; 1303 1304 np->queues = NULL; 1305 1306 err = -ENOMEM; 1307 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1308 if (np->rx_stats == NULL) 1309 goto exit; 1310 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1311 if (np->tx_stats == NULL) 1312 goto exit; 1313 1314 netdev->netdev_ops = &xennet_netdev_ops; 1315 1316 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1317 NETIF_F_GSO_ROBUST; 1318 netdev->hw_features = NETIF_F_SG | 1319 NETIF_F_IPV6_CSUM | 1320 NETIF_F_TSO | NETIF_F_TSO6; 1321 1322 /* 1323 * Assume that all hw features are available for now. This set 1324 * will be adjusted by the call to netdev_update_features() in 1325 * xennet_connect() which is the earliest point where we can 1326 * negotiate with the backend regarding supported features. 1327 */ 1328 netdev->features |= netdev->hw_features; 1329 1330 netdev->ethtool_ops = &xennet_ethtool_ops; 1331 netdev->min_mtu = ETH_MIN_MTU; 1332 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; 1333 SET_NETDEV_DEV(netdev, &dev->dev); 1334 1335 np->netdev = netdev; 1336 1337 netif_carrier_off(netdev); 1338 1339 do { 1340 xenbus_switch_state(dev, XenbusStateInitialising); 1341 err = wait_event_timeout(module_wq, 1342 xenbus_read_driver_state(dev->otherend) != 1343 XenbusStateClosed && 1344 xenbus_read_driver_state(dev->otherend) != 1345 XenbusStateUnknown, XENNET_TIMEOUT); 1346 } while (!err); 1347 1348 return netdev; 1349 1350 exit: 1351 xennet_free_netdev(netdev); 1352 return ERR_PTR(err); 1353 } 1354 1355 /** 1356 * Entry point to this code when a new device is created. Allocate the basic 1357 * structures and the ring buffers for communication with the backend, and 1358 * inform the backend of the appropriate details for those. 1359 */ 1360 static int netfront_probe(struct xenbus_device *dev, 1361 const struct xenbus_device_id *id) 1362 { 1363 int err; 1364 struct net_device *netdev; 1365 struct netfront_info *info; 1366 1367 netdev = xennet_create_dev(dev); 1368 if (IS_ERR(netdev)) { 1369 err = PTR_ERR(netdev); 1370 xenbus_dev_fatal(dev, err, "creating netdev"); 1371 return err; 1372 } 1373 1374 info = netdev_priv(netdev); 1375 dev_set_drvdata(&dev->dev, info); 1376 #ifdef CONFIG_SYSFS 1377 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1378 #endif 1379 1380 return 0; 1381 } 1382 1383 static void xennet_end_access(int ref, void *page) 1384 { 1385 /* This frees the page as a side-effect */ 1386 if (ref != GRANT_INVALID_REF) 1387 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1388 } 1389 1390 static void xennet_disconnect_backend(struct netfront_info *info) 1391 { 1392 unsigned int i = 0; 1393 unsigned int num_queues = info->netdev->real_num_tx_queues; 1394 1395 netif_carrier_off(info->netdev); 1396 1397 for (i = 0; i < num_queues && info->queues; ++i) { 1398 struct netfront_queue *queue = &info->queues[i]; 1399 1400 del_timer_sync(&queue->rx_refill_timer); 1401 1402 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1403 unbind_from_irqhandler(queue->tx_irq, queue); 1404 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1405 unbind_from_irqhandler(queue->tx_irq, queue); 1406 unbind_from_irqhandler(queue->rx_irq, queue); 1407 } 1408 queue->tx_evtchn = queue->rx_evtchn = 0; 1409 queue->tx_irq = queue->rx_irq = 0; 1410 1411 if (netif_running(info->netdev)) 1412 napi_synchronize(&queue->napi); 1413 1414 xennet_release_tx_bufs(queue); 1415 xennet_release_rx_bufs(queue); 1416 gnttab_free_grant_references(queue->gref_tx_head); 1417 gnttab_free_grant_references(queue->gref_rx_head); 1418 1419 /* End access and free the pages */ 1420 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1421 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1422 1423 queue->tx_ring_ref = GRANT_INVALID_REF; 1424 queue->rx_ring_ref = GRANT_INVALID_REF; 1425 queue->tx.sring = NULL; 1426 queue->rx.sring = NULL; 1427 } 1428 } 1429 1430 /** 1431 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1432 * driver restart. We tear down our netif structure and recreate it, but 1433 * leave the device-layer structures intact so that this is transparent to the 1434 * rest of the kernel. 1435 */ 1436 static int netfront_resume(struct xenbus_device *dev) 1437 { 1438 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1439 1440 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1441 1442 xennet_disconnect_backend(info); 1443 return 0; 1444 } 1445 1446 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1447 { 1448 char *s, *e, *macstr; 1449 int i; 1450 1451 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1452 if (IS_ERR(macstr)) 1453 return PTR_ERR(macstr); 1454 1455 for (i = 0; i < ETH_ALEN; i++) { 1456 mac[i] = simple_strtoul(s, &e, 16); 1457 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1458 kfree(macstr); 1459 return -ENOENT; 1460 } 1461 s = e+1; 1462 } 1463 1464 kfree(macstr); 1465 return 0; 1466 } 1467 1468 static int setup_netfront_single(struct netfront_queue *queue) 1469 { 1470 int err; 1471 1472 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1473 if (err < 0) 1474 goto fail; 1475 1476 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1477 xennet_interrupt, 1478 0, queue->info->netdev->name, queue); 1479 if (err < 0) 1480 goto bind_fail; 1481 queue->rx_evtchn = queue->tx_evtchn; 1482 queue->rx_irq = queue->tx_irq = err; 1483 1484 return 0; 1485 1486 bind_fail: 1487 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1488 queue->tx_evtchn = 0; 1489 fail: 1490 return err; 1491 } 1492 1493 static int setup_netfront_split(struct netfront_queue *queue) 1494 { 1495 int err; 1496 1497 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1498 if (err < 0) 1499 goto fail; 1500 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1501 if (err < 0) 1502 goto alloc_rx_evtchn_fail; 1503 1504 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1505 "%s-tx", queue->name); 1506 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1507 xennet_tx_interrupt, 1508 0, queue->tx_irq_name, queue); 1509 if (err < 0) 1510 goto bind_tx_fail; 1511 queue->tx_irq = err; 1512 1513 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1514 "%s-rx", queue->name); 1515 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1516 xennet_rx_interrupt, 1517 0, queue->rx_irq_name, queue); 1518 if (err < 0) 1519 goto bind_rx_fail; 1520 queue->rx_irq = err; 1521 1522 return 0; 1523 1524 bind_rx_fail: 1525 unbind_from_irqhandler(queue->tx_irq, queue); 1526 queue->tx_irq = 0; 1527 bind_tx_fail: 1528 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1529 queue->rx_evtchn = 0; 1530 alloc_rx_evtchn_fail: 1531 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1532 queue->tx_evtchn = 0; 1533 fail: 1534 return err; 1535 } 1536 1537 static int setup_netfront(struct xenbus_device *dev, 1538 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1539 { 1540 struct xen_netif_tx_sring *txs; 1541 struct xen_netif_rx_sring *rxs; 1542 grant_ref_t gref; 1543 int err; 1544 1545 queue->tx_ring_ref = GRANT_INVALID_REF; 1546 queue->rx_ring_ref = GRANT_INVALID_REF; 1547 queue->rx.sring = NULL; 1548 queue->tx.sring = NULL; 1549 1550 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1551 if (!txs) { 1552 err = -ENOMEM; 1553 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1554 goto fail; 1555 } 1556 SHARED_RING_INIT(txs); 1557 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); 1558 1559 err = xenbus_grant_ring(dev, txs, 1, &gref); 1560 if (err < 0) 1561 goto grant_tx_ring_fail; 1562 queue->tx_ring_ref = gref; 1563 1564 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1565 if (!rxs) { 1566 err = -ENOMEM; 1567 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1568 goto alloc_rx_ring_fail; 1569 } 1570 SHARED_RING_INIT(rxs); 1571 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); 1572 1573 err = xenbus_grant_ring(dev, rxs, 1, &gref); 1574 if (err < 0) 1575 goto grant_rx_ring_fail; 1576 queue->rx_ring_ref = gref; 1577 1578 if (feature_split_evtchn) 1579 err = setup_netfront_split(queue); 1580 /* setup single event channel if 1581 * a) feature-split-event-channels == 0 1582 * b) feature-split-event-channels == 1 but failed to setup 1583 */ 1584 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1585 err = setup_netfront_single(queue); 1586 1587 if (err) 1588 goto alloc_evtchn_fail; 1589 1590 return 0; 1591 1592 /* If we fail to setup netfront, it is safe to just revoke access to 1593 * granted pages because backend is not accessing it at this point. 1594 */ 1595 alloc_evtchn_fail: 1596 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1597 grant_rx_ring_fail: 1598 free_page((unsigned long)rxs); 1599 alloc_rx_ring_fail: 1600 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1601 grant_tx_ring_fail: 1602 free_page((unsigned long)txs); 1603 fail: 1604 return err; 1605 } 1606 1607 /* Queue-specific initialisation 1608 * This used to be done in xennet_create_dev() but must now 1609 * be run per-queue. 1610 */ 1611 static int xennet_init_queue(struct netfront_queue *queue) 1612 { 1613 unsigned short i; 1614 int err = 0; 1615 char *devid; 1616 1617 spin_lock_init(&queue->tx_lock); 1618 spin_lock_init(&queue->rx_lock); 1619 1620 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); 1621 1622 devid = strrchr(queue->info->xbdev->nodename, '/') + 1; 1623 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u", 1624 devid, queue->id); 1625 1626 /* Initialise tx_skbs as a free chain containing every entry. */ 1627 queue->tx_skb_freelist = 0; 1628 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1629 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1630 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1631 queue->grant_tx_page[i] = NULL; 1632 } 1633 1634 /* Clear out rx_skbs */ 1635 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1636 queue->rx_skbs[i] = NULL; 1637 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1638 } 1639 1640 /* A grant for every tx ring slot */ 1641 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1642 &queue->gref_tx_head) < 0) { 1643 pr_alert("can't alloc tx grant refs\n"); 1644 err = -ENOMEM; 1645 goto exit; 1646 } 1647 1648 /* A grant for every rx ring slot */ 1649 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1650 &queue->gref_rx_head) < 0) { 1651 pr_alert("can't alloc rx grant refs\n"); 1652 err = -ENOMEM; 1653 goto exit_free_tx; 1654 } 1655 1656 return 0; 1657 1658 exit_free_tx: 1659 gnttab_free_grant_references(queue->gref_tx_head); 1660 exit: 1661 return err; 1662 } 1663 1664 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1665 struct xenbus_transaction *xbt, int write_hierarchical) 1666 { 1667 /* Write the queue-specific keys into XenStore in the traditional 1668 * way for a single queue, or in a queue subkeys for multiple 1669 * queues. 1670 */ 1671 struct xenbus_device *dev = queue->info->xbdev; 1672 int err; 1673 const char *message; 1674 char *path; 1675 size_t pathsize; 1676 1677 /* Choose the correct place to write the keys */ 1678 if (write_hierarchical) { 1679 pathsize = strlen(dev->nodename) + 10; 1680 path = kzalloc(pathsize, GFP_KERNEL); 1681 if (!path) { 1682 err = -ENOMEM; 1683 message = "out of memory while writing ring references"; 1684 goto error; 1685 } 1686 snprintf(path, pathsize, "%s/queue-%u", 1687 dev->nodename, queue->id); 1688 } else { 1689 path = (char *)dev->nodename; 1690 } 1691 1692 /* Write ring references */ 1693 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1694 queue->tx_ring_ref); 1695 if (err) { 1696 message = "writing tx-ring-ref"; 1697 goto error; 1698 } 1699 1700 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1701 queue->rx_ring_ref); 1702 if (err) { 1703 message = "writing rx-ring-ref"; 1704 goto error; 1705 } 1706 1707 /* Write event channels; taking into account both shared 1708 * and split event channel scenarios. 1709 */ 1710 if (queue->tx_evtchn == queue->rx_evtchn) { 1711 /* Shared event channel */ 1712 err = xenbus_printf(*xbt, path, 1713 "event-channel", "%u", queue->tx_evtchn); 1714 if (err) { 1715 message = "writing event-channel"; 1716 goto error; 1717 } 1718 } else { 1719 /* Split event channels */ 1720 err = xenbus_printf(*xbt, path, 1721 "event-channel-tx", "%u", queue->tx_evtchn); 1722 if (err) { 1723 message = "writing event-channel-tx"; 1724 goto error; 1725 } 1726 1727 err = xenbus_printf(*xbt, path, 1728 "event-channel-rx", "%u", queue->rx_evtchn); 1729 if (err) { 1730 message = "writing event-channel-rx"; 1731 goto error; 1732 } 1733 } 1734 1735 if (write_hierarchical) 1736 kfree(path); 1737 return 0; 1738 1739 error: 1740 if (write_hierarchical) 1741 kfree(path); 1742 xenbus_dev_fatal(dev, err, "%s", message); 1743 return err; 1744 } 1745 1746 static void xennet_destroy_queues(struct netfront_info *info) 1747 { 1748 unsigned int i; 1749 1750 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1751 struct netfront_queue *queue = &info->queues[i]; 1752 1753 if (netif_running(info->netdev)) 1754 napi_disable(&queue->napi); 1755 netif_napi_del(&queue->napi); 1756 } 1757 1758 kfree(info->queues); 1759 info->queues = NULL; 1760 } 1761 1762 static int xennet_create_queues(struct netfront_info *info, 1763 unsigned int *num_queues) 1764 { 1765 unsigned int i; 1766 int ret; 1767 1768 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), 1769 GFP_KERNEL); 1770 if (!info->queues) 1771 return -ENOMEM; 1772 1773 for (i = 0; i < *num_queues; i++) { 1774 struct netfront_queue *queue = &info->queues[i]; 1775 1776 queue->id = i; 1777 queue->info = info; 1778 1779 ret = xennet_init_queue(queue); 1780 if (ret < 0) { 1781 dev_warn(&info->xbdev->dev, 1782 "only created %d queues\n", i); 1783 *num_queues = i; 1784 break; 1785 } 1786 1787 netif_napi_add(queue->info->netdev, &queue->napi, 1788 xennet_poll, 64); 1789 if (netif_running(info->netdev)) 1790 napi_enable(&queue->napi); 1791 } 1792 1793 netif_set_real_num_tx_queues(info->netdev, *num_queues); 1794 1795 if (*num_queues == 0) { 1796 dev_err(&info->xbdev->dev, "no queues\n"); 1797 return -EINVAL; 1798 } 1799 return 0; 1800 } 1801 1802 /* Common code used when first setting up, and when resuming. */ 1803 static int talk_to_netback(struct xenbus_device *dev, 1804 struct netfront_info *info) 1805 { 1806 const char *message; 1807 struct xenbus_transaction xbt; 1808 int err; 1809 unsigned int feature_split_evtchn; 1810 unsigned int i = 0; 1811 unsigned int max_queues = 0; 1812 struct netfront_queue *queue = NULL; 1813 unsigned int num_queues = 1; 1814 1815 info->netdev->irq = 0; 1816 1817 /* Check if backend supports multiple queues */ 1818 max_queues = xenbus_read_unsigned(info->xbdev->otherend, 1819 "multi-queue-max-queues", 1); 1820 num_queues = min(max_queues, xennet_max_queues); 1821 1822 /* Check feature-split-event-channels */ 1823 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, 1824 "feature-split-event-channels", 0); 1825 1826 /* Read mac addr. */ 1827 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1828 if (err) { 1829 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1830 goto out_unlocked; 1831 } 1832 1833 rtnl_lock(); 1834 if (info->queues) 1835 xennet_destroy_queues(info); 1836 1837 err = xennet_create_queues(info, &num_queues); 1838 if (err < 0) { 1839 xenbus_dev_fatal(dev, err, "creating queues"); 1840 kfree(info->queues); 1841 info->queues = NULL; 1842 goto out; 1843 } 1844 rtnl_unlock(); 1845 1846 /* Create shared ring, alloc event channel -- for each queue */ 1847 for (i = 0; i < num_queues; ++i) { 1848 queue = &info->queues[i]; 1849 err = setup_netfront(dev, queue, feature_split_evtchn); 1850 if (err) 1851 goto destroy_ring; 1852 } 1853 1854 again: 1855 err = xenbus_transaction_start(&xbt); 1856 if (err) { 1857 xenbus_dev_fatal(dev, err, "starting transaction"); 1858 goto destroy_ring; 1859 } 1860 1861 if (xenbus_exists(XBT_NIL, 1862 info->xbdev->otherend, "multi-queue-max-queues")) { 1863 /* Write the number of queues */ 1864 err = xenbus_printf(xbt, dev->nodename, 1865 "multi-queue-num-queues", "%u", num_queues); 1866 if (err) { 1867 message = "writing multi-queue-num-queues"; 1868 goto abort_transaction_no_dev_fatal; 1869 } 1870 } 1871 1872 if (num_queues == 1) { 1873 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1874 if (err) 1875 goto abort_transaction_no_dev_fatal; 1876 } else { 1877 /* Write the keys for each queue */ 1878 for (i = 0; i < num_queues; ++i) { 1879 queue = &info->queues[i]; 1880 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1881 if (err) 1882 goto abort_transaction_no_dev_fatal; 1883 } 1884 } 1885 1886 /* The remaining keys are not queue-specific */ 1887 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1888 1); 1889 if (err) { 1890 message = "writing request-rx-copy"; 1891 goto abort_transaction; 1892 } 1893 1894 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1895 if (err) { 1896 message = "writing feature-rx-notify"; 1897 goto abort_transaction; 1898 } 1899 1900 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1901 if (err) { 1902 message = "writing feature-sg"; 1903 goto abort_transaction; 1904 } 1905 1906 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1907 if (err) { 1908 message = "writing feature-gso-tcpv4"; 1909 goto abort_transaction; 1910 } 1911 1912 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1913 if (err) { 1914 message = "writing feature-gso-tcpv6"; 1915 goto abort_transaction; 1916 } 1917 1918 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1919 "1"); 1920 if (err) { 1921 message = "writing feature-ipv6-csum-offload"; 1922 goto abort_transaction; 1923 } 1924 1925 err = xenbus_transaction_end(xbt, 0); 1926 if (err) { 1927 if (err == -EAGAIN) 1928 goto again; 1929 xenbus_dev_fatal(dev, err, "completing transaction"); 1930 goto destroy_ring; 1931 } 1932 1933 return 0; 1934 1935 abort_transaction: 1936 xenbus_dev_fatal(dev, err, "%s", message); 1937 abort_transaction_no_dev_fatal: 1938 xenbus_transaction_end(xbt, 1); 1939 destroy_ring: 1940 xennet_disconnect_backend(info); 1941 rtnl_lock(); 1942 xennet_destroy_queues(info); 1943 out: 1944 rtnl_unlock(); 1945 out_unlocked: 1946 device_unregister(&dev->dev); 1947 return err; 1948 } 1949 1950 static int xennet_connect(struct net_device *dev) 1951 { 1952 struct netfront_info *np = netdev_priv(dev); 1953 unsigned int num_queues = 0; 1954 int err; 1955 unsigned int j = 0; 1956 struct netfront_queue *queue = NULL; 1957 1958 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { 1959 dev_info(&dev->dev, 1960 "backend does not support copying receive path\n"); 1961 return -ENODEV; 1962 } 1963 1964 err = talk_to_netback(np->xbdev, np); 1965 if (err) 1966 return err; 1967 1968 /* talk_to_netback() sets the correct number of queues */ 1969 num_queues = dev->real_num_tx_queues; 1970 1971 if (dev->reg_state == NETREG_UNINITIALIZED) { 1972 err = register_netdev(dev); 1973 if (err) { 1974 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1975 device_unregister(&np->xbdev->dev); 1976 return err; 1977 } 1978 } 1979 1980 rtnl_lock(); 1981 netdev_update_features(dev); 1982 rtnl_unlock(); 1983 1984 /* 1985 * All public and private state should now be sane. Get 1986 * ready to start sending and receiving packets and give the driver 1987 * domain a kick because we've probably just requeued some 1988 * packets. 1989 */ 1990 netif_carrier_on(np->netdev); 1991 for (j = 0; j < num_queues; ++j) { 1992 queue = &np->queues[j]; 1993 1994 notify_remote_via_irq(queue->tx_irq); 1995 if (queue->tx_irq != queue->rx_irq) 1996 notify_remote_via_irq(queue->rx_irq); 1997 1998 spin_lock_irq(&queue->tx_lock); 1999 xennet_tx_buf_gc(queue); 2000 spin_unlock_irq(&queue->tx_lock); 2001 2002 spin_lock_bh(&queue->rx_lock); 2003 xennet_alloc_rx_buffers(queue); 2004 spin_unlock_bh(&queue->rx_lock); 2005 } 2006 2007 return 0; 2008 } 2009 2010 /** 2011 * Callback received when the backend's state changes. 2012 */ 2013 static void netback_changed(struct xenbus_device *dev, 2014 enum xenbus_state backend_state) 2015 { 2016 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2017 struct net_device *netdev = np->netdev; 2018 2019 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2020 2021 wake_up_all(&module_wq); 2022 2023 switch (backend_state) { 2024 case XenbusStateInitialising: 2025 case XenbusStateInitialised: 2026 case XenbusStateReconfiguring: 2027 case XenbusStateReconfigured: 2028 case XenbusStateUnknown: 2029 break; 2030 2031 case XenbusStateInitWait: 2032 if (dev->state != XenbusStateInitialising) 2033 break; 2034 if (xennet_connect(netdev) != 0) 2035 break; 2036 xenbus_switch_state(dev, XenbusStateConnected); 2037 break; 2038 2039 case XenbusStateConnected: 2040 netdev_notify_peers(netdev); 2041 break; 2042 2043 case XenbusStateClosed: 2044 if (dev->state == XenbusStateClosed) 2045 break; 2046 /* Fall through - Missed the backend's CLOSING state. */ 2047 case XenbusStateClosing: 2048 xenbus_frontend_closed(dev); 2049 break; 2050 } 2051 } 2052 2053 static const struct xennet_stat { 2054 char name[ETH_GSTRING_LEN]; 2055 u16 offset; 2056 } xennet_stats[] = { 2057 { 2058 "rx_gso_checksum_fixup", 2059 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2060 }, 2061 }; 2062 2063 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2064 { 2065 switch (string_set) { 2066 case ETH_SS_STATS: 2067 return ARRAY_SIZE(xennet_stats); 2068 default: 2069 return -EINVAL; 2070 } 2071 } 2072 2073 static void xennet_get_ethtool_stats(struct net_device *dev, 2074 struct ethtool_stats *stats, u64 * data) 2075 { 2076 void *np = netdev_priv(dev); 2077 int i; 2078 2079 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2080 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2081 } 2082 2083 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2084 { 2085 int i; 2086 2087 switch (stringset) { 2088 case ETH_SS_STATS: 2089 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2090 memcpy(data + i * ETH_GSTRING_LEN, 2091 xennet_stats[i].name, ETH_GSTRING_LEN); 2092 break; 2093 } 2094 } 2095 2096 static const struct ethtool_ops xennet_ethtool_ops = 2097 { 2098 .get_link = ethtool_op_get_link, 2099 2100 .get_sset_count = xennet_get_sset_count, 2101 .get_ethtool_stats = xennet_get_ethtool_stats, 2102 .get_strings = xennet_get_strings, 2103 }; 2104 2105 #ifdef CONFIG_SYSFS 2106 static ssize_t show_rxbuf(struct device *dev, 2107 struct device_attribute *attr, char *buf) 2108 { 2109 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2110 } 2111 2112 static ssize_t store_rxbuf(struct device *dev, 2113 struct device_attribute *attr, 2114 const char *buf, size_t len) 2115 { 2116 char *endp; 2117 unsigned long target; 2118 2119 if (!capable(CAP_NET_ADMIN)) 2120 return -EPERM; 2121 2122 target = simple_strtoul(buf, &endp, 0); 2123 if (endp == buf) 2124 return -EBADMSG; 2125 2126 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2127 2128 return len; 2129 } 2130 2131 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf); 2132 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf); 2133 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL); 2134 2135 static struct attribute *xennet_dev_attrs[] = { 2136 &dev_attr_rxbuf_min.attr, 2137 &dev_attr_rxbuf_max.attr, 2138 &dev_attr_rxbuf_cur.attr, 2139 NULL 2140 }; 2141 2142 static const struct attribute_group xennet_dev_group = { 2143 .attrs = xennet_dev_attrs 2144 }; 2145 #endif /* CONFIG_SYSFS */ 2146 2147 static void xennet_bus_close(struct xenbus_device *dev) 2148 { 2149 int ret; 2150 2151 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed) 2152 return; 2153 do { 2154 xenbus_switch_state(dev, XenbusStateClosing); 2155 ret = wait_event_timeout(module_wq, 2156 xenbus_read_driver_state(dev->otherend) == 2157 XenbusStateClosing || 2158 xenbus_read_driver_state(dev->otherend) == 2159 XenbusStateClosed || 2160 xenbus_read_driver_state(dev->otherend) == 2161 XenbusStateUnknown, 2162 XENNET_TIMEOUT); 2163 } while (!ret); 2164 2165 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed) 2166 return; 2167 2168 do { 2169 xenbus_switch_state(dev, XenbusStateClosed); 2170 ret = wait_event_timeout(module_wq, 2171 xenbus_read_driver_state(dev->otherend) == 2172 XenbusStateClosed || 2173 xenbus_read_driver_state(dev->otherend) == 2174 XenbusStateUnknown, 2175 XENNET_TIMEOUT); 2176 } while (!ret); 2177 } 2178 2179 static int xennet_remove(struct xenbus_device *dev) 2180 { 2181 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2182 2183 xennet_bus_close(dev); 2184 xennet_disconnect_backend(info); 2185 2186 if (info->netdev->reg_state == NETREG_REGISTERED) 2187 unregister_netdev(info->netdev); 2188 2189 if (info->queues) { 2190 rtnl_lock(); 2191 xennet_destroy_queues(info); 2192 rtnl_unlock(); 2193 } 2194 xennet_free_netdev(info->netdev); 2195 2196 return 0; 2197 } 2198 2199 static const struct xenbus_device_id netfront_ids[] = { 2200 { "vif" }, 2201 { "" } 2202 }; 2203 2204 static struct xenbus_driver netfront_driver = { 2205 .ids = netfront_ids, 2206 .probe = netfront_probe, 2207 .remove = xennet_remove, 2208 .resume = netfront_resume, 2209 .otherend_changed = netback_changed, 2210 }; 2211 2212 static int __init netif_init(void) 2213 { 2214 if (!xen_domain()) 2215 return -ENODEV; 2216 2217 if (!xen_has_pv_nic_devices()) 2218 return -ENODEV; 2219 2220 pr_info("Initialising Xen virtual ethernet driver\n"); 2221 2222 /* Allow as many queues as there are CPUs inut max. 8 if user has not 2223 * specified a value. 2224 */ 2225 if (xennet_max_queues == 0) 2226 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, 2227 num_online_cpus()); 2228 2229 return xenbus_register_frontend(&netfront_driver); 2230 } 2231 module_init(netif_init); 2232 2233 2234 static void __exit netif_exit(void) 2235 { 2236 xenbus_unregister_driver(&netfront_driver); 2237 } 2238 module_exit(netif_exit); 2239 2240 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2241 MODULE_LICENSE("GPL"); 2242 MODULE_ALIAS("xen:vif"); 2243 MODULE_ALIAS("xennet"); 2244