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