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, PAGE_SIZE) 78 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, 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 unsigned long pfn; 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 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); 311 312 req = RING_GET_REQUEST(&queue->rx, req_prod); 313 gnttab_grant_foreign_access_ref(ref, 314 queue->info->xbdev->otherend_id, 315 pfn_to_mfn(pfn), 316 0); 317 318 req->id = id; 319 req->gref = ref; 320 } 321 322 queue->rx.req_prod_pvt = req_prod; 323 324 /* Not enough requests? Try again later. */ 325 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) { 326 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); 327 return; 328 } 329 330 wmb(); /* barrier so backend seens requests */ 331 332 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 333 if (notify) 334 notify_remote_via_irq(queue->rx_irq); 335 } 336 337 static int xennet_open(struct net_device *dev) 338 { 339 struct netfront_info *np = netdev_priv(dev); 340 unsigned int num_queues = dev->real_num_tx_queues; 341 unsigned int i = 0; 342 struct netfront_queue *queue = NULL; 343 344 for (i = 0; i < num_queues; ++i) { 345 queue = &np->queues[i]; 346 napi_enable(&queue->napi); 347 348 spin_lock_bh(&queue->rx_lock); 349 if (netif_carrier_ok(dev)) { 350 xennet_alloc_rx_buffers(queue); 351 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 352 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 353 napi_schedule(&queue->napi); 354 } 355 spin_unlock_bh(&queue->rx_lock); 356 } 357 358 netif_tx_start_all_queues(dev); 359 360 return 0; 361 } 362 363 static void xennet_tx_buf_gc(struct netfront_queue *queue) 364 { 365 RING_IDX cons, prod; 366 unsigned short id; 367 struct sk_buff *skb; 368 369 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 370 371 do { 372 prod = queue->tx.sring->rsp_prod; 373 rmb(); /* Ensure we see responses up to 'rp'. */ 374 375 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 376 struct xen_netif_tx_response *txrsp; 377 378 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 379 if (txrsp->status == XEN_NETIF_RSP_NULL) 380 continue; 381 382 id = txrsp->id; 383 skb = queue->tx_skbs[id].skb; 384 if (unlikely(gnttab_query_foreign_access( 385 queue->grant_tx_ref[id]) != 0)) { 386 pr_alert("%s: warning -- grant still in use by backend domain\n", 387 __func__); 388 BUG(); 389 } 390 gnttab_end_foreign_access_ref( 391 queue->grant_tx_ref[id], GNTMAP_readonly); 392 gnttab_release_grant_reference( 393 &queue->gref_tx_head, queue->grant_tx_ref[id]); 394 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 395 queue->grant_tx_page[id] = NULL; 396 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 397 dev_kfree_skb_irq(skb); 398 } 399 400 queue->tx.rsp_cons = prod; 401 402 /* 403 * Set a new event, then check for race with update of tx_cons. 404 * Note that it is essential to schedule a callback, no matter 405 * how few buffers are pending. Even if there is space in the 406 * transmit ring, higher layers may be blocked because too much 407 * data is outstanding: in such cases notification from Xen is 408 * likely to be the only kick that we'll get. 409 */ 410 queue->tx.sring->rsp_event = 411 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1; 412 mb(); /* update shared area */ 413 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod)); 414 415 xennet_maybe_wake_tx(queue); 416 } 417 418 static struct xen_netif_tx_request *xennet_make_one_txreq( 419 struct netfront_queue *queue, struct sk_buff *skb, 420 struct page *page, unsigned int offset, unsigned int len) 421 { 422 unsigned int id; 423 struct xen_netif_tx_request *tx; 424 grant_ref_t ref; 425 426 len = min_t(unsigned int, PAGE_SIZE - offset, len); 427 428 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 429 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 430 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 431 BUG_ON((signed short)ref < 0); 432 433 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 434 page_to_mfn(page), GNTMAP_readonly); 435 436 queue->tx_skbs[id].skb = skb; 437 queue->grant_tx_page[id] = page; 438 queue->grant_tx_ref[id] = ref; 439 440 tx->id = id; 441 tx->gref = ref; 442 tx->offset = offset; 443 tx->size = len; 444 tx->flags = 0; 445 446 return tx; 447 } 448 449 static struct xen_netif_tx_request *xennet_make_txreqs( 450 struct netfront_queue *queue, struct xen_netif_tx_request *tx, 451 struct sk_buff *skb, struct page *page, 452 unsigned int offset, unsigned int len) 453 { 454 /* Skip unused frames from start of page */ 455 page += offset >> PAGE_SHIFT; 456 offset &= ~PAGE_MASK; 457 458 while (len) { 459 tx->flags |= XEN_NETTXF_more_data; 460 tx = xennet_make_one_txreq(queue, skb_get(skb), 461 page, offset, len); 462 page++; 463 offset = 0; 464 len -= tx->size; 465 } 466 467 return tx; 468 } 469 470 /* 471 * Count how many ring slots are required to send this skb. Each frag 472 * might be a compound page. 473 */ 474 static int xennet_count_skb_slots(struct sk_buff *skb) 475 { 476 int i, frags = skb_shinfo(skb)->nr_frags; 477 int pages; 478 479 pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb)); 480 481 for (i = 0; i < frags; i++) { 482 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 483 unsigned long size = skb_frag_size(frag); 484 unsigned long offset = frag->page_offset; 485 486 /* Skip unused frames from start of page */ 487 offset &= ~PAGE_MASK; 488 489 pages += PFN_UP(offset + size); 490 } 491 492 return pages; 493 } 494 495 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 496 void *accel_priv, select_queue_fallback_t fallback) 497 { 498 unsigned int num_queues = dev->real_num_tx_queues; 499 u32 hash; 500 u16 queue_idx; 501 502 /* First, check if there is only one queue */ 503 if (num_queues == 1) { 504 queue_idx = 0; 505 } else { 506 hash = skb_get_hash(skb); 507 queue_idx = hash % num_queues; 508 } 509 510 return queue_idx; 511 } 512 513 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 514 { 515 struct netfront_info *np = netdev_priv(dev); 516 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 517 struct xen_netif_tx_request *tx, *first_tx; 518 unsigned int i; 519 int notify; 520 int slots; 521 struct page *page; 522 unsigned int offset; 523 unsigned int len; 524 unsigned long flags; 525 struct netfront_queue *queue = NULL; 526 unsigned int num_queues = dev->real_num_tx_queues; 527 u16 queue_index; 528 529 /* Drop the packet if no queues are set up */ 530 if (num_queues < 1) 531 goto drop; 532 /* Determine which queue to transmit this SKB on */ 533 queue_index = skb_get_queue_mapping(skb); 534 queue = &np->queues[queue_index]; 535 536 /* If skb->len is too big for wire format, drop skb and alert 537 * user about misconfiguration. 538 */ 539 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 540 net_alert_ratelimited( 541 "xennet: skb->len = %u, too big for wire format\n", 542 skb->len); 543 goto drop; 544 } 545 546 slots = xennet_count_skb_slots(skb); 547 if (unlikely(slots > MAX_SKB_FRAGS + 1)) { 548 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 549 slots, skb->len); 550 if (skb_linearize(skb)) 551 goto drop; 552 } 553 554 page = virt_to_page(skb->data); 555 offset = offset_in_page(skb->data); 556 len = skb_headlen(skb); 557 558 spin_lock_irqsave(&queue->tx_lock, flags); 559 560 if (unlikely(!netif_carrier_ok(dev) || 561 (slots > 1 && !xennet_can_sg(dev)) || 562 netif_needs_gso(skb, netif_skb_features(skb)))) { 563 spin_unlock_irqrestore(&queue->tx_lock, flags); 564 goto drop; 565 } 566 567 /* First request for the linear area. */ 568 first_tx = tx = xennet_make_one_txreq(queue, skb, 569 page, offset, len); 570 page++; 571 offset = 0; 572 len -= tx->size; 573 574 if (skb->ip_summed == CHECKSUM_PARTIAL) 575 /* local packet? */ 576 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 577 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 578 /* remote but checksummed. */ 579 tx->flags |= XEN_NETTXF_data_validated; 580 581 /* Optional extra info after the first request. */ 582 if (skb_shinfo(skb)->gso_size) { 583 struct xen_netif_extra_info *gso; 584 585 gso = (struct xen_netif_extra_info *) 586 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 587 588 tx->flags |= XEN_NETTXF_extra_info; 589 590 gso->u.gso.size = skb_shinfo(skb)->gso_size; 591 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 592 XEN_NETIF_GSO_TYPE_TCPV6 : 593 XEN_NETIF_GSO_TYPE_TCPV4; 594 gso->u.gso.pad = 0; 595 gso->u.gso.features = 0; 596 597 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 598 gso->flags = 0; 599 } 600 601 /* Requests for the rest of the linear area. */ 602 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); 603 604 /* Requests for all the frags. */ 605 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 606 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 607 tx = xennet_make_txreqs(queue, tx, skb, 608 skb_frag_page(frag), frag->page_offset, 609 skb_frag_size(frag)); 610 } 611 612 /* First request has the packet length. */ 613 first_tx->size = skb->len; 614 615 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 616 if (notify) 617 notify_remote_via_irq(queue->tx_irq); 618 619 u64_stats_update_begin(&tx_stats->syncp); 620 tx_stats->bytes += skb->len; 621 tx_stats->packets++; 622 u64_stats_update_end(&tx_stats->syncp); 623 624 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 625 xennet_tx_buf_gc(queue); 626 627 if (!netfront_tx_slot_available(queue)) 628 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 629 630 spin_unlock_irqrestore(&queue->tx_lock, flags); 631 632 return NETDEV_TX_OK; 633 634 drop: 635 dev->stats.tx_dropped++; 636 dev_kfree_skb_any(skb); 637 return NETDEV_TX_OK; 638 } 639 640 static int xennet_close(struct net_device *dev) 641 { 642 struct netfront_info *np = netdev_priv(dev); 643 unsigned int num_queues = dev->real_num_tx_queues; 644 unsigned int i; 645 struct netfront_queue *queue; 646 netif_tx_stop_all_queues(np->netdev); 647 for (i = 0; i < num_queues; ++i) { 648 queue = &np->queues[i]; 649 napi_disable(&queue->napi); 650 } 651 return 0; 652 } 653 654 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 655 grant_ref_t ref) 656 { 657 int new = xennet_rxidx(queue->rx.req_prod_pvt); 658 659 BUG_ON(queue->rx_skbs[new]); 660 queue->rx_skbs[new] = skb; 661 queue->grant_rx_ref[new] = ref; 662 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 663 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 664 queue->rx.req_prod_pvt++; 665 } 666 667 static int xennet_get_extras(struct netfront_queue *queue, 668 struct xen_netif_extra_info *extras, 669 RING_IDX rp) 670 671 { 672 struct xen_netif_extra_info *extra; 673 struct device *dev = &queue->info->netdev->dev; 674 RING_IDX cons = queue->rx.rsp_cons; 675 int err = 0; 676 677 do { 678 struct sk_buff *skb; 679 grant_ref_t ref; 680 681 if (unlikely(cons + 1 == rp)) { 682 if (net_ratelimit()) 683 dev_warn(dev, "Missing extra info\n"); 684 err = -EBADR; 685 break; 686 } 687 688 extra = (struct xen_netif_extra_info *) 689 RING_GET_RESPONSE(&queue->rx, ++cons); 690 691 if (unlikely(!extra->type || 692 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 693 if (net_ratelimit()) 694 dev_warn(dev, "Invalid extra type: %d\n", 695 extra->type); 696 err = -EINVAL; 697 } else { 698 memcpy(&extras[extra->type - 1], extra, 699 sizeof(*extra)); 700 } 701 702 skb = xennet_get_rx_skb(queue, cons); 703 ref = xennet_get_rx_ref(queue, cons); 704 xennet_move_rx_slot(queue, skb, ref); 705 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 706 707 queue->rx.rsp_cons = cons; 708 return err; 709 } 710 711 static int xennet_get_responses(struct netfront_queue *queue, 712 struct netfront_rx_info *rinfo, RING_IDX rp, 713 struct sk_buff_head *list) 714 { 715 struct xen_netif_rx_response *rx = &rinfo->rx; 716 struct xen_netif_extra_info *extras = rinfo->extras; 717 struct device *dev = &queue->info->netdev->dev; 718 RING_IDX cons = queue->rx.rsp_cons; 719 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 720 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 721 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 722 int slots = 1; 723 int err = 0; 724 unsigned long ret; 725 726 if (rx->flags & XEN_NETRXF_extra_info) { 727 err = xennet_get_extras(queue, extras, rp); 728 cons = queue->rx.rsp_cons; 729 } 730 731 for (;;) { 732 if (unlikely(rx->status < 0 || 733 rx->offset + rx->status > PAGE_SIZE)) { 734 if (net_ratelimit()) 735 dev_warn(dev, "rx->offset: %u, size: %d\n", 736 rx->offset, rx->status); 737 xennet_move_rx_slot(queue, skb, ref); 738 err = -EINVAL; 739 goto next; 740 } 741 742 /* 743 * This definitely indicates a bug, either in this driver or in 744 * the backend driver. In future this should flag the bad 745 * situation to the system controller to reboot the backend. 746 */ 747 if (ref == GRANT_INVALID_REF) { 748 if (net_ratelimit()) 749 dev_warn(dev, "Bad rx response id %d.\n", 750 rx->id); 751 err = -EINVAL; 752 goto next; 753 } 754 755 ret = gnttab_end_foreign_access_ref(ref, 0); 756 BUG_ON(!ret); 757 758 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 759 760 __skb_queue_tail(list, skb); 761 762 next: 763 if (!(rx->flags & XEN_NETRXF_more_data)) 764 break; 765 766 if (cons + slots == rp) { 767 if (net_ratelimit()) 768 dev_warn(dev, "Need more slots\n"); 769 err = -ENOENT; 770 break; 771 } 772 773 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 774 skb = xennet_get_rx_skb(queue, cons + slots); 775 ref = xennet_get_rx_ref(queue, cons + slots); 776 slots++; 777 } 778 779 if (unlikely(slots > max)) { 780 if (net_ratelimit()) 781 dev_warn(dev, "Too many slots\n"); 782 err = -E2BIG; 783 } 784 785 if (unlikely(err)) 786 queue->rx.rsp_cons = cons + slots; 787 788 return err; 789 } 790 791 static int xennet_set_skb_gso(struct sk_buff *skb, 792 struct xen_netif_extra_info *gso) 793 { 794 if (!gso->u.gso.size) { 795 if (net_ratelimit()) 796 pr_warn("GSO size must not be zero\n"); 797 return -EINVAL; 798 } 799 800 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 801 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 802 if (net_ratelimit()) 803 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 804 return -EINVAL; 805 } 806 807 skb_shinfo(skb)->gso_size = gso->u.gso.size; 808 skb_shinfo(skb)->gso_type = 809 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 810 SKB_GSO_TCPV4 : 811 SKB_GSO_TCPV6; 812 813 /* Header must be checked, and gso_segs computed. */ 814 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 815 skb_shinfo(skb)->gso_segs = 0; 816 817 return 0; 818 } 819 820 static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 821 struct sk_buff *skb, 822 struct sk_buff_head *list) 823 { 824 struct skb_shared_info *shinfo = skb_shinfo(skb); 825 RING_IDX cons = queue->rx.rsp_cons; 826 struct sk_buff *nskb; 827 828 while ((nskb = __skb_dequeue(list))) { 829 struct xen_netif_rx_response *rx = 830 RING_GET_RESPONSE(&queue->rx, ++cons); 831 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 832 833 if (shinfo->nr_frags == MAX_SKB_FRAGS) { 834 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 835 836 BUG_ON(pull_to <= skb_headlen(skb)); 837 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 838 } 839 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); 840 841 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), 842 rx->offset, rx->status, PAGE_SIZE); 843 844 skb_shinfo(nskb)->nr_frags = 0; 845 kfree_skb(nskb); 846 } 847 848 return cons; 849 } 850 851 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 852 { 853 bool recalculate_partial_csum = false; 854 855 /* 856 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 857 * peers can fail to set NETRXF_csum_blank when sending a GSO 858 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 859 * recalculate the partial checksum. 860 */ 861 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 862 struct netfront_info *np = netdev_priv(dev); 863 atomic_inc(&np->rx_gso_checksum_fixup); 864 skb->ip_summed = CHECKSUM_PARTIAL; 865 recalculate_partial_csum = true; 866 } 867 868 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 869 if (skb->ip_summed != CHECKSUM_PARTIAL) 870 return 0; 871 872 return skb_checksum_setup(skb, recalculate_partial_csum); 873 } 874 875 static int handle_incoming_queue(struct netfront_queue *queue, 876 struct sk_buff_head *rxq) 877 { 878 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 879 int packets_dropped = 0; 880 struct sk_buff *skb; 881 882 while ((skb = __skb_dequeue(rxq)) != NULL) { 883 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 884 885 if (pull_to > skb_headlen(skb)) 886 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 887 888 /* Ethernet work: Delayed to here as it peeks the header. */ 889 skb->protocol = eth_type_trans(skb, queue->info->netdev); 890 skb_reset_network_header(skb); 891 892 if (checksum_setup(queue->info->netdev, skb)) { 893 kfree_skb(skb); 894 packets_dropped++; 895 queue->info->netdev->stats.rx_errors++; 896 continue; 897 } 898 899 u64_stats_update_begin(&rx_stats->syncp); 900 rx_stats->packets++; 901 rx_stats->bytes += skb->len; 902 u64_stats_update_end(&rx_stats->syncp); 903 904 /* Pass it up. */ 905 napi_gro_receive(&queue->napi, skb); 906 } 907 908 return packets_dropped; 909 } 910 911 static int xennet_poll(struct napi_struct *napi, int budget) 912 { 913 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 914 struct net_device *dev = queue->info->netdev; 915 struct sk_buff *skb; 916 struct netfront_rx_info rinfo; 917 struct xen_netif_rx_response *rx = &rinfo.rx; 918 struct xen_netif_extra_info *extras = rinfo.extras; 919 RING_IDX i, rp; 920 int work_done; 921 struct sk_buff_head rxq; 922 struct sk_buff_head errq; 923 struct sk_buff_head tmpq; 924 int err; 925 926 spin_lock(&queue->rx_lock); 927 928 skb_queue_head_init(&rxq); 929 skb_queue_head_init(&errq); 930 skb_queue_head_init(&tmpq); 931 932 rp = queue->rx.sring->rsp_prod; 933 rmb(); /* Ensure we see queued responses up to 'rp'. */ 934 935 i = queue->rx.rsp_cons; 936 work_done = 0; 937 while ((i != rp) && (work_done < budget)) { 938 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 939 memset(extras, 0, sizeof(rinfo.extras)); 940 941 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 942 943 if (unlikely(err)) { 944 err: 945 while ((skb = __skb_dequeue(&tmpq))) 946 __skb_queue_tail(&errq, skb); 947 dev->stats.rx_errors++; 948 i = queue->rx.rsp_cons; 949 continue; 950 } 951 952 skb = __skb_dequeue(&tmpq); 953 954 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 955 struct xen_netif_extra_info *gso; 956 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 957 958 if (unlikely(xennet_set_skb_gso(skb, gso))) { 959 __skb_queue_head(&tmpq, skb); 960 queue->rx.rsp_cons += skb_queue_len(&tmpq); 961 goto err; 962 } 963 } 964 965 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 966 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 967 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 968 969 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 970 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 971 skb->data_len = rx->status; 972 skb->len += rx->status; 973 974 i = xennet_fill_frags(queue, skb, &tmpq); 975 976 if (rx->flags & XEN_NETRXF_csum_blank) 977 skb->ip_summed = CHECKSUM_PARTIAL; 978 else if (rx->flags & XEN_NETRXF_data_validated) 979 skb->ip_summed = CHECKSUM_UNNECESSARY; 980 981 __skb_queue_tail(&rxq, skb); 982 983 queue->rx.rsp_cons = ++i; 984 work_done++; 985 } 986 987 __skb_queue_purge(&errq); 988 989 work_done -= handle_incoming_queue(queue, &rxq); 990 991 xennet_alloc_rx_buffers(queue); 992 993 if (work_done < budget) { 994 int more_to_do = 0; 995 996 napi_complete(napi); 997 998 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 999 if (more_to_do) 1000 napi_schedule(napi); 1001 } 1002 1003 spin_unlock(&queue->rx_lock); 1004 1005 return work_done; 1006 } 1007 1008 static int xennet_change_mtu(struct net_device *dev, int mtu) 1009 { 1010 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1011 1012 if (mtu > max) 1013 return -EINVAL; 1014 dev->mtu = mtu; 1015 return 0; 1016 } 1017 1018 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, 1019 struct rtnl_link_stats64 *tot) 1020 { 1021 struct netfront_info *np = netdev_priv(dev); 1022 int cpu; 1023 1024 for_each_possible_cpu(cpu) { 1025 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1026 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1027 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1028 unsigned int start; 1029 1030 do { 1031 start = u64_stats_fetch_begin_irq(&tx_stats->syncp); 1032 tx_packets = tx_stats->packets; 1033 tx_bytes = tx_stats->bytes; 1034 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); 1035 1036 do { 1037 start = u64_stats_fetch_begin_irq(&rx_stats->syncp); 1038 rx_packets = rx_stats->packets; 1039 rx_bytes = rx_stats->bytes; 1040 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); 1041 1042 tot->rx_packets += rx_packets; 1043 tot->tx_packets += tx_packets; 1044 tot->rx_bytes += rx_bytes; 1045 tot->tx_bytes += tx_bytes; 1046 } 1047 1048 tot->rx_errors = dev->stats.rx_errors; 1049 tot->tx_dropped = dev->stats.tx_dropped; 1050 1051 return tot; 1052 } 1053 1054 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1055 { 1056 struct sk_buff *skb; 1057 int i; 1058 1059 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1060 /* Skip over entries which are actually freelist references */ 1061 if (skb_entry_is_link(&queue->tx_skbs[i])) 1062 continue; 1063 1064 skb = queue->tx_skbs[i].skb; 1065 get_page(queue->grant_tx_page[i]); 1066 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1067 GNTMAP_readonly, 1068 (unsigned long)page_address(queue->grant_tx_page[i])); 1069 queue->grant_tx_page[i] = NULL; 1070 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1071 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1072 dev_kfree_skb_irq(skb); 1073 } 1074 } 1075 1076 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1077 { 1078 int id, ref; 1079 1080 spin_lock_bh(&queue->rx_lock); 1081 1082 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1083 struct sk_buff *skb; 1084 struct page *page; 1085 1086 skb = queue->rx_skbs[id]; 1087 if (!skb) 1088 continue; 1089 1090 ref = queue->grant_rx_ref[id]; 1091 if (ref == GRANT_INVALID_REF) 1092 continue; 1093 1094 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1095 1096 /* gnttab_end_foreign_access() needs a page ref until 1097 * foreign access is ended (which may be deferred). 1098 */ 1099 get_page(page); 1100 gnttab_end_foreign_access(ref, 0, 1101 (unsigned long)page_address(page)); 1102 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1103 1104 kfree_skb(skb); 1105 } 1106 1107 spin_unlock_bh(&queue->rx_lock); 1108 } 1109 1110 static netdev_features_t xennet_fix_features(struct net_device *dev, 1111 netdev_features_t features) 1112 { 1113 struct netfront_info *np = netdev_priv(dev); 1114 int val; 1115 1116 if (features & NETIF_F_SG) { 1117 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1118 "%d", &val) < 0) 1119 val = 0; 1120 1121 if (!val) 1122 features &= ~NETIF_F_SG; 1123 } 1124 1125 if (features & NETIF_F_IPV6_CSUM) { 1126 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1127 "feature-ipv6-csum-offload", "%d", &val) < 0) 1128 val = 0; 1129 1130 if (!val) 1131 features &= ~NETIF_F_IPV6_CSUM; 1132 } 1133 1134 if (features & NETIF_F_TSO) { 1135 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1136 "feature-gso-tcpv4", "%d", &val) < 0) 1137 val = 0; 1138 1139 if (!val) 1140 features &= ~NETIF_F_TSO; 1141 } 1142 1143 if (features & NETIF_F_TSO6) { 1144 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1145 "feature-gso-tcpv6", "%d", &val) < 0) 1146 val = 0; 1147 1148 if (!val) 1149 features &= ~NETIF_F_TSO6; 1150 } 1151 1152 return features; 1153 } 1154 1155 static int xennet_set_features(struct net_device *dev, 1156 netdev_features_t features) 1157 { 1158 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1159 netdev_info(dev, "Reducing MTU because no SG offload"); 1160 dev->mtu = ETH_DATA_LEN; 1161 } 1162 1163 return 0; 1164 } 1165 1166 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1167 { 1168 struct netfront_queue *queue = dev_id; 1169 unsigned long flags; 1170 1171 spin_lock_irqsave(&queue->tx_lock, flags); 1172 xennet_tx_buf_gc(queue); 1173 spin_unlock_irqrestore(&queue->tx_lock, flags); 1174 1175 return IRQ_HANDLED; 1176 } 1177 1178 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1179 { 1180 struct netfront_queue *queue = dev_id; 1181 struct net_device *dev = queue->info->netdev; 1182 1183 if (likely(netif_carrier_ok(dev) && 1184 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1185 napi_schedule(&queue->napi); 1186 1187 return IRQ_HANDLED; 1188 } 1189 1190 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1191 { 1192 xennet_tx_interrupt(irq, dev_id); 1193 xennet_rx_interrupt(irq, dev_id); 1194 return IRQ_HANDLED; 1195 } 1196 1197 #ifdef CONFIG_NET_POLL_CONTROLLER 1198 static void xennet_poll_controller(struct net_device *dev) 1199 { 1200 /* Poll each queue */ 1201 struct netfront_info *info = netdev_priv(dev); 1202 unsigned int num_queues = dev->real_num_tx_queues; 1203 unsigned int i; 1204 for (i = 0; i < num_queues; ++i) 1205 xennet_interrupt(0, &info->queues[i]); 1206 } 1207 #endif 1208 1209 static const struct net_device_ops xennet_netdev_ops = { 1210 .ndo_open = xennet_open, 1211 .ndo_stop = xennet_close, 1212 .ndo_start_xmit = xennet_start_xmit, 1213 .ndo_change_mtu = xennet_change_mtu, 1214 .ndo_get_stats64 = xennet_get_stats64, 1215 .ndo_set_mac_address = eth_mac_addr, 1216 .ndo_validate_addr = eth_validate_addr, 1217 .ndo_fix_features = xennet_fix_features, 1218 .ndo_set_features = xennet_set_features, 1219 .ndo_select_queue = xennet_select_queue, 1220 #ifdef CONFIG_NET_POLL_CONTROLLER 1221 .ndo_poll_controller = xennet_poll_controller, 1222 #endif 1223 }; 1224 1225 static void xennet_free_netdev(struct net_device *netdev) 1226 { 1227 struct netfront_info *np = netdev_priv(netdev); 1228 1229 free_percpu(np->rx_stats); 1230 free_percpu(np->tx_stats); 1231 free_netdev(netdev); 1232 } 1233 1234 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1235 { 1236 int err; 1237 struct net_device *netdev; 1238 struct netfront_info *np; 1239 1240 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1241 if (!netdev) 1242 return ERR_PTR(-ENOMEM); 1243 1244 np = netdev_priv(netdev); 1245 np->xbdev = dev; 1246 1247 np->queues = NULL; 1248 1249 err = -ENOMEM; 1250 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1251 if (np->rx_stats == NULL) 1252 goto exit; 1253 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1254 if (np->tx_stats == NULL) 1255 goto exit; 1256 1257 netdev->netdev_ops = &xennet_netdev_ops; 1258 1259 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1260 NETIF_F_GSO_ROBUST; 1261 netdev->hw_features = NETIF_F_SG | 1262 NETIF_F_IPV6_CSUM | 1263 NETIF_F_TSO | NETIF_F_TSO6; 1264 1265 /* 1266 * Assume that all hw features are available for now. This set 1267 * will be adjusted by the call to netdev_update_features() in 1268 * xennet_connect() which is the earliest point where we can 1269 * negotiate with the backend regarding supported features. 1270 */ 1271 netdev->features |= netdev->hw_features; 1272 1273 netdev->ethtool_ops = &xennet_ethtool_ops; 1274 SET_NETDEV_DEV(netdev, &dev->dev); 1275 1276 np->netdev = netdev; 1277 1278 netif_carrier_off(netdev); 1279 1280 return netdev; 1281 1282 exit: 1283 xennet_free_netdev(netdev); 1284 return ERR_PTR(err); 1285 } 1286 1287 /** 1288 * Entry point to this code when a new device is created. Allocate the basic 1289 * structures and the ring buffers for communication with the backend, and 1290 * inform the backend of the appropriate details for those. 1291 */ 1292 static int netfront_probe(struct xenbus_device *dev, 1293 const struct xenbus_device_id *id) 1294 { 1295 int err; 1296 struct net_device *netdev; 1297 struct netfront_info *info; 1298 1299 netdev = xennet_create_dev(dev); 1300 if (IS_ERR(netdev)) { 1301 err = PTR_ERR(netdev); 1302 xenbus_dev_fatal(dev, err, "creating netdev"); 1303 return err; 1304 } 1305 1306 info = netdev_priv(netdev); 1307 dev_set_drvdata(&dev->dev, info); 1308 #ifdef CONFIG_SYSFS 1309 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1310 #endif 1311 err = register_netdev(info->netdev); 1312 if (err) { 1313 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1314 goto fail; 1315 } 1316 1317 return 0; 1318 1319 fail: 1320 xennet_free_netdev(netdev); 1321 dev_set_drvdata(&dev->dev, NULL); 1322 return err; 1323 } 1324 1325 static void xennet_end_access(int ref, void *page) 1326 { 1327 /* This frees the page as a side-effect */ 1328 if (ref != GRANT_INVALID_REF) 1329 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1330 } 1331 1332 static void xennet_disconnect_backend(struct netfront_info *info) 1333 { 1334 unsigned int i = 0; 1335 unsigned int num_queues = info->netdev->real_num_tx_queues; 1336 1337 netif_carrier_off(info->netdev); 1338 1339 for (i = 0; i < num_queues; ++i) { 1340 struct netfront_queue *queue = &info->queues[i]; 1341 1342 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1343 unbind_from_irqhandler(queue->tx_irq, queue); 1344 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1345 unbind_from_irqhandler(queue->tx_irq, queue); 1346 unbind_from_irqhandler(queue->rx_irq, queue); 1347 } 1348 queue->tx_evtchn = queue->rx_evtchn = 0; 1349 queue->tx_irq = queue->rx_irq = 0; 1350 1351 napi_synchronize(&queue->napi); 1352 1353 xennet_release_tx_bufs(queue); 1354 xennet_release_rx_bufs(queue); 1355 gnttab_free_grant_references(queue->gref_tx_head); 1356 gnttab_free_grant_references(queue->gref_rx_head); 1357 1358 /* End access and free the pages */ 1359 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1360 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1361 1362 queue->tx_ring_ref = GRANT_INVALID_REF; 1363 queue->rx_ring_ref = GRANT_INVALID_REF; 1364 queue->tx.sring = NULL; 1365 queue->rx.sring = NULL; 1366 } 1367 } 1368 1369 /** 1370 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1371 * driver restart. We tear down our netif structure and recreate it, but 1372 * leave the device-layer structures intact so that this is transparent to the 1373 * rest of the kernel. 1374 */ 1375 static int netfront_resume(struct xenbus_device *dev) 1376 { 1377 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1378 1379 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1380 1381 xennet_disconnect_backend(info); 1382 return 0; 1383 } 1384 1385 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1386 { 1387 char *s, *e, *macstr; 1388 int i; 1389 1390 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1391 if (IS_ERR(macstr)) 1392 return PTR_ERR(macstr); 1393 1394 for (i = 0; i < ETH_ALEN; i++) { 1395 mac[i] = simple_strtoul(s, &e, 16); 1396 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1397 kfree(macstr); 1398 return -ENOENT; 1399 } 1400 s = e+1; 1401 } 1402 1403 kfree(macstr); 1404 return 0; 1405 } 1406 1407 static int setup_netfront_single(struct netfront_queue *queue) 1408 { 1409 int err; 1410 1411 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1412 if (err < 0) 1413 goto fail; 1414 1415 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1416 xennet_interrupt, 1417 0, queue->info->netdev->name, queue); 1418 if (err < 0) 1419 goto bind_fail; 1420 queue->rx_evtchn = queue->tx_evtchn; 1421 queue->rx_irq = queue->tx_irq = err; 1422 1423 return 0; 1424 1425 bind_fail: 1426 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1427 queue->tx_evtchn = 0; 1428 fail: 1429 return err; 1430 } 1431 1432 static int setup_netfront_split(struct netfront_queue *queue) 1433 { 1434 int err; 1435 1436 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1437 if (err < 0) 1438 goto fail; 1439 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1440 if (err < 0) 1441 goto alloc_rx_evtchn_fail; 1442 1443 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1444 "%s-tx", queue->name); 1445 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1446 xennet_tx_interrupt, 1447 0, queue->tx_irq_name, queue); 1448 if (err < 0) 1449 goto bind_tx_fail; 1450 queue->tx_irq = err; 1451 1452 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1453 "%s-rx", queue->name); 1454 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1455 xennet_rx_interrupt, 1456 0, queue->rx_irq_name, queue); 1457 if (err < 0) 1458 goto bind_rx_fail; 1459 queue->rx_irq = err; 1460 1461 return 0; 1462 1463 bind_rx_fail: 1464 unbind_from_irqhandler(queue->tx_irq, queue); 1465 queue->tx_irq = 0; 1466 bind_tx_fail: 1467 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1468 queue->rx_evtchn = 0; 1469 alloc_rx_evtchn_fail: 1470 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1471 queue->tx_evtchn = 0; 1472 fail: 1473 return err; 1474 } 1475 1476 static int setup_netfront(struct xenbus_device *dev, 1477 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1478 { 1479 struct xen_netif_tx_sring *txs; 1480 struct xen_netif_rx_sring *rxs; 1481 grant_ref_t gref; 1482 int err; 1483 1484 queue->tx_ring_ref = GRANT_INVALID_REF; 1485 queue->rx_ring_ref = GRANT_INVALID_REF; 1486 queue->rx.sring = NULL; 1487 queue->tx.sring = NULL; 1488 1489 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1490 if (!txs) { 1491 err = -ENOMEM; 1492 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1493 goto fail; 1494 } 1495 SHARED_RING_INIT(txs); 1496 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE); 1497 1498 err = xenbus_grant_ring(dev, txs, 1, &gref); 1499 if (err < 0) 1500 goto grant_tx_ring_fail; 1501 queue->tx_ring_ref = gref; 1502 1503 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1504 if (!rxs) { 1505 err = -ENOMEM; 1506 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1507 goto alloc_rx_ring_fail; 1508 } 1509 SHARED_RING_INIT(rxs); 1510 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE); 1511 1512 err = xenbus_grant_ring(dev, rxs, 1, &gref); 1513 if (err < 0) 1514 goto grant_rx_ring_fail; 1515 queue->rx_ring_ref = gref; 1516 1517 if (feature_split_evtchn) 1518 err = setup_netfront_split(queue); 1519 /* setup single event channel if 1520 * a) feature-split-event-channels == 0 1521 * b) feature-split-event-channels == 1 but failed to setup 1522 */ 1523 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1524 err = setup_netfront_single(queue); 1525 1526 if (err) 1527 goto alloc_evtchn_fail; 1528 1529 return 0; 1530 1531 /* If we fail to setup netfront, it is safe to just revoke access to 1532 * granted pages because backend is not accessing it at this point. 1533 */ 1534 alloc_evtchn_fail: 1535 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1536 grant_rx_ring_fail: 1537 free_page((unsigned long)rxs); 1538 alloc_rx_ring_fail: 1539 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1540 grant_tx_ring_fail: 1541 free_page((unsigned long)txs); 1542 fail: 1543 return err; 1544 } 1545 1546 /* Queue-specific initialisation 1547 * This used to be done in xennet_create_dev() but must now 1548 * be run per-queue. 1549 */ 1550 static int xennet_init_queue(struct netfront_queue *queue) 1551 { 1552 unsigned short i; 1553 int err = 0; 1554 1555 spin_lock_init(&queue->tx_lock); 1556 spin_lock_init(&queue->rx_lock); 1557 1558 setup_timer(&queue->rx_refill_timer, rx_refill_timeout, 1559 (unsigned long)queue); 1560 1561 snprintf(queue->name, sizeof(queue->name), "%s-q%u", 1562 queue->info->netdev->name, queue->id); 1563 1564 /* Initialise tx_skbs as a free chain containing every entry. */ 1565 queue->tx_skb_freelist = 0; 1566 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1567 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1568 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1569 queue->grant_tx_page[i] = NULL; 1570 } 1571 1572 /* Clear out rx_skbs */ 1573 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1574 queue->rx_skbs[i] = NULL; 1575 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1576 } 1577 1578 /* A grant for every tx ring slot */ 1579 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1580 &queue->gref_tx_head) < 0) { 1581 pr_alert("can't alloc tx grant refs\n"); 1582 err = -ENOMEM; 1583 goto exit; 1584 } 1585 1586 /* A grant for every rx ring slot */ 1587 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1588 &queue->gref_rx_head) < 0) { 1589 pr_alert("can't alloc rx grant refs\n"); 1590 err = -ENOMEM; 1591 goto exit_free_tx; 1592 } 1593 1594 return 0; 1595 1596 exit_free_tx: 1597 gnttab_free_grant_references(queue->gref_tx_head); 1598 exit: 1599 return err; 1600 } 1601 1602 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1603 struct xenbus_transaction *xbt, int write_hierarchical) 1604 { 1605 /* Write the queue-specific keys into XenStore in the traditional 1606 * way for a single queue, or in a queue subkeys for multiple 1607 * queues. 1608 */ 1609 struct xenbus_device *dev = queue->info->xbdev; 1610 int err; 1611 const char *message; 1612 char *path; 1613 size_t pathsize; 1614 1615 /* Choose the correct place to write the keys */ 1616 if (write_hierarchical) { 1617 pathsize = strlen(dev->nodename) + 10; 1618 path = kzalloc(pathsize, GFP_KERNEL); 1619 if (!path) { 1620 err = -ENOMEM; 1621 message = "out of memory while writing ring references"; 1622 goto error; 1623 } 1624 snprintf(path, pathsize, "%s/queue-%u", 1625 dev->nodename, queue->id); 1626 } else { 1627 path = (char *)dev->nodename; 1628 } 1629 1630 /* Write ring references */ 1631 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1632 queue->tx_ring_ref); 1633 if (err) { 1634 message = "writing tx-ring-ref"; 1635 goto error; 1636 } 1637 1638 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1639 queue->rx_ring_ref); 1640 if (err) { 1641 message = "writing rx-ring-ref"; 1642 goto error; 1643 } 1644 1645 /* Write event channels; taking into account both shared 1646 * and split event channel scenarios. 1647 */ 1648 if (queue->tx_evtchn == queue->rx_evtchn) { 1649 /* Shared event channel */ 1650 err = xenbus_printf(*xbt, path, 1651 "event-channel", "%u", queue->tx_evtchn); 1652 if (err) { 1653 message = "writing event-channel"; 1654 goto error; 1655 } 1656 } else { 1657 /* Split event channels */ 1658 err = xenbus_printf(*xbt, path, 1659 "event-channel-tx", "%u", queue->tx_evtchn); 1660 if (err) { 1661 message = "writing event-channel-tx"; 1662 goto error; 1663 } 1664 1665 err = xenbus_printf(*xbt, path, 1666 "event-channel-rx", "%u", queue->rx_evtchn); 1667 if (err) { 1668 message = "writing event-channel-rx"; 1669 goto error; 1670 } 1671 } 1672 1673 if (write_hierarchical) 1674 kfree(path); 1675 return 0; 1676 1677 error: 1678 if (write_hierarchical) 1679 kfree(path); 1680 xenbus_dev_fatal(dev, err, "%s", message); 1681 return err; 1682 } 1683 1684 static void xennet_destroy_queues(struct netfront_info *info) 1685 { 1686 unsigned int i; 1687 1688 rtnl_lock(); 1689 1690 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1691 struct netfront_queue *queue = &info->queues[i]; 1692 1693 if (netif_running(info->netdev)) 1694 napi_disable(&queue->napi); 1695 del_timer_sync(&queue->rx_refill_timer); 1696 netif_napi_del(&queue->napi); 1697 } 1698 1699 rtnl_unlock(); 1700 1701 kfree(info->queues); 1702 info->queues = NULL; 1703 } 1704 1705 static int xennet_create_queues(struct netfront_info *info, 1706 unsigned int num_queues) 1707 { 1708 unsigned int i; 1709 int ret; 1710 1711 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue), 1712 GFP_KERNEL); 1713 if (!info->queues) 1714 return -ENOMEM; 1715 1716 rtnl_lock(); 1717 1718 for (i = 0; i < num_queues; i++) { 1719 struct netfront_queue *queue = &info->queues[i]; 1720 1721 queue->id = i; 1722 queue->info = info; 1723 1724 ret = xennet_init_queue(queue); 1725 if (ret < 0) { 1726 dev_warn(&info->netdev->dev, 1727 "only created %d queues\n", i); 1728 num_queues = i; 1729 break; 1730 } 1731 1732 netif_napi_add(queue->info->netdev, &queue->napi, 1733 xennet_poll, 64); 1734 if (netif_running(info->netdev)) 1735 napi_enable(&queue->napi); 1736 } 1737 1738 netif_set_real_num_tx_queues(info->netdev, num_queues); 1739 1740 rtnl_unlock(); 1741 1742 if (num_queues == 0) { 1743 dev_err(&info->netdev->dev, "no queues\n"); 1744 return -EINVAL; 1745 } 1746 return 0; 1747 } 1748 1749 /* Common code used when first setting up, and when resuming. */ 1750 static int talk_to_netback(struct xenbus_device *dev, 1751 struct netfront_info *info) 1752 { 1753 const char *message; 1754 struct xenbus_transaction xbt; 1755 int err; 1756 unsigned int feature_split_evtchn; 1757 unsigned int i = 0; 1758 unsigned int max_queues = 0; 1759 struct netfront_queue *queue = NULL; 1760 unsigned int num_queues = 1; 1761 1762 info->netdev->irq = 0; 1763 1764 /* Check if backend supports multiple queues */ 1765 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1766 "multi-queue-max-queues", "%u", &max_queues); 1767 if (err < 0) 1768 max_queues = 1; 1769 num_queues = min(max_queues, xennet_max_queues); 1770 1771 /* Check feature-split-event-channels */ 1772 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1773 "feature-split-event-channels", "%u", 1774 &feature_split_evtchn); 1775 if (err < 0) 1776 feature_split_evtchn = 0; 1777 1778 /* Read mac addr. */ 1779 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1780 if (err) { 1781 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1782 goto out; 1783 } 1784 1785 if (info->queues) 1786 xennet_destroy_queues(info); 1787 1788 err = xennet_create_queues(info, num_queues); 1789 if (err < 0) 1790 goto destroy_ring; 1791 1792 /* Create shared ring, alloc event channel -- for each queue */ 1793 for (i = 0; i < num_queues; ++i) { 1794 queue = &info->queues[i]; 1795 err = setup_netfront(dev, queue, feature_split_evtchn); 1796 if (err) { 1797 /* setup_netfront() will tidy up the current 1798 * queue on error, but we need to clean up 1799 * those already allocated. 1800 */ 1801 if (i > 0) { 1802 rtnl_lock(); 1803 netif_set_real_num_tx_queues(info->netdev, i); 1804 rtnl_unlock(); 1805 goto destroy_ring; 1806 } else { 1807 goto out; 1808 } 1809 } 1810 } 1811 1812 again: 1813 err = xenbus_transaction_start(&xbt); 1814 if (err) { 1815 xenbus_dev_fatal(dev, err, "starting transaction"); 1816 goto destroy_ring; 1817 } 1818 1819 if (num_queues == 1) { 1820 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1821 if (err) 1822 goto abort_transaction_no_dev_fatal; 1823 } else { 1824 /* Write the number of queues */ 1825 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", 1826 "%u", num_queues); 1827 if (err) { 1828 message = "writing multi-queue-num-queues"; 1829 goto abort_transaction_no_dev_fatal; 1830 } 1831 1832 /* Write the keys for each queue */ 1833 for (i = 0; i < num_queues; ++i) { 1834 queue = &info->queues[i]; 1835 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1836 if (err) 1837 goto abort_transaction_no_dev_fatal; 1838 } 1839 } 1840 1841 /* The remaining keys are not queue-specific */ 1842 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1843 1); 1844 if (err) { 1845 message = "writing request-rx-copy"; 1846 goto abort_transaction; 1847 } 1848 1849 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1850 if (err) { 1851 message = "writing feature-rx-notify"; 1852 goto abort_transaction; 1853 } 1854 1855 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1856 if (err) { 1857 message = "writing feature-sg"; 1858 goto abort_transaction; 1859 } 1860 1861 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1862 if (err) { 1863 message = "writing feature-gso-tcpv4"; 1864 goto abort_transaction; 1865 } 1866 1867 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1868 if (err) { 1869 message = "writing feature-gso-tcpv6"; 1870 goto abort_transaction; 1871 } 1872 1873 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1874 "1"); 1875 if (err) { 1876 message = "writing feature-ipv6-csum-offload"; 1877 goto abort_transaction; 1878 } 1879 1880 err = xenbus_transaction_end(xbt, 0); 1881 if (err) { 1882 if (err == -EAGAIN) 1883 goto again; 1884 xenbus_dev_fatal(dev, err, "completing transaction"); 1885 goto destroy_ring; 1886 } 1887 1888 return 0; 1889 1890 abort_transaction: 1891 xenbus_dev_fatal(dev, err, "%s", message); 1892 abort_transaction_no_dev_fatal: 1893 xenbus_transaction_end(xbt, 1); 1894 destroy_ring: 1895 xennet_disconnect_backend(info); 1896 kfree(info->queues); 1897 info->queues = NULL; 1898 out: 1899 return err; 1900 } 1901 1902 static int xennet_connect(struct net_device *dev) 1903 { 1904 struct netfront_info *np = netdev_priv(dev); 1905 unsigned int num_queues = 0; 1906 int err; 1907 unsigned int feature_rx_copy; 1908 unsigned int j = 0; 1909 struct netfront_queue *queue = NULL; 1910 1911 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1912 "feature-rx-copy", "%u", &feature_rx_copy); 1913 if (err != 1) 1914 feature_rx_copy = 0; 1915 1916 if (!feature_rx_copy) { 1917 dev_info(&dev->dev, 1918 "backend does not support copying receive path\n"); 1919 return -ENODEV; 1920 } 1921 1922 err = talk_to_netback(np->xbdev, np); 1923 if (err) 1924 return err; 1925 1926 /* talk_to_netback() sets the correct number of queues */ 1927 num_queues = dev->real_num_tx_queues; 1928 1929 rtnl_lock(); 1930 netdev_update_features(dev); 1931 rtnl_unlock(); 1932 1933 /* 1934 * All public and private state should now be sane. Get 1935 * ready to start sending and receiving packets and give the driver 1936 * domain a kick because we've probably just requeued some 1937 * packets. 1938 */ 1939 netif_carrier_on(np->netdev); 1940 for (j = 0; j < num_queues; ++j) { 1941 queue = &np->queues[j]; 1942 1943 notify_remote_via_irq(queue->tx_irq); 1944 if (queue->tx_irq != queue->rx_irq) 1945 notify_remote_via_irq(queue->rx_irq); 1946 1947 spin_lock_irq(&queue->tx_lock); 1948 xennet_tx_buf_gc(queue); 1949 spin_unlock_irq(&queue->tx_lock); 1950 1951 spin_lock_bh(&queue->rx_lock); 1952 xennet_alloc_rx_buffers(queue); 1953 spin_unlock_bh(&queue->rx_lock); 1954 } 1955 1956 return 0; 1957 } 1958 1959 /** 1960 * Callback received when the backend's state changes. 1961 */ 1962 static void netback_changed(struct xenbus_device *dev, 1963 enum xenbus_state backend_state) 1964 { 1965 struct netfront_info *np = dev_get_drvdata(&dev->dev); 1966 struct net_device *netdev = np->netdev; 1967 1968 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 1969 1970 switch (backend_state) { 1971 case XenbusStateInitialising: 1972 case XenbusStateInitialised: 1973 case XenbusStateReconfiguring: 1974 case XenbusStateReconfigured: 1975 case XenbusStateUnknown: 1976 break; 1977 1978 case XenbusStateInitWait: 1979 if (dev->state != XenbusStateInitialising) 1980 break; 1981 if (xennet_connect(netdev) != 0) 1982 break; 1983 xenbus_switch_state(dev, XenbusStateConnected); 1984 break; 1985 1986 case XenbusStateConnected: 1987 netdev_notify_peers(netdev); 1988 break; 1989 1990 case XenbusStateClosed: 1991 if (dev->state == XenbusStateClosed) 1992 break; 1993 /* Missed the backend's CLOSING state -- fallthrough */ 1994 case XenbusStateClosing: 1995 xenbus_frontend_closed(dev); 1996 break; 1997 } 1998 } 1999 2000 static const struct xennet_stat { 2001 char name[ETH_GSTRING_LEN]; 2002 u16 offset; 2003 } xennet_stats[] = { 2004 { 2005 "rx_gso_checksum_fixup", 2006 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2007 }, 2008 }; 2009 2010 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2011 { 2012 switch (string_set) { 2013 case ETH_SS_STATS: 2014 return ARRAY_SIZE(xennet_stats); 2015 default: 2016 return -EINVAL; 2017 } 2018 } 2019 2020 static void xennet_get_ethtool_stats(struct net_device *dev, 2021 struct ethtool_stats *stats, u64 * data) 2022 { 2023 void *np = netdev_priv(dev); 2024 int i; 2025 2026 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2027 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2028 } 2029 2030 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2031 { 2032 int i; 2033 2034 switch (stringset) { 2035 case ETH_SS_STATS: 2036 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2037 memcpy(data + i * ETH_GSTRING_LEN, 2038 xennet_stats[i].name, ETH_GSTRING_LEN); 2039 break; 2040 } 2041 } 2042 2043 static const struct ethtool_ops xennet_ethtool_ops = 2044 { 2045 .get_link = ethtool_op_get_link, 2046 2047 .get_sset_count = xennet_get_sset_count, 2048 .get_ethtool_stats = xennet_get_ethtool_stats, 2049 .get_strings = xennet_get_strings, 2050 }; 2051 2052 #ifdef CONFIG_SYSFS 2053 static ssize_t show_rxbuf(struct device *dev, 2054 struct device_attribute *attr, char *buf) 2055 { 2056 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2057 } 2058 2059 static ssize_t store_rxbuf(struct device *dev, 2060 struct device_attribute *attr, 2061 const char *buf, size_t len) 2062 { 2063 char *endp; 2064 unsigned long target; 2065 2066 if (!capable(CAP_NET_ADMIN)) 2067 return -EPERM; 2068 2069 target = simple_strtoul(buf, &endp, 0); 2070 if (endp == buf) 2071 return -EBADMSG; 2072 2073 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2074 2075 return len; 2076 } 2077 2078 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf); 2079 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf); 2080 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL); 2081 2082 static struct attribute *xennet_dev_attrs[] = { 2083 &dev_attr_rxbuf_min.attr, 2084 &dev_attr_rxbuf_max.attr, 2085 &dev_attr_rxbuf_cur.attr, 2086 NULL 2087 }; 2088 2089 static const struct attribute_group xennet_dev_group = { 2090 .attrs = xennet_dev_attrs 2091 }; 2092 #endif /* CONFIG_SYSFS */ 2093 2094 static int xennet_remove(struct xenbus_device *dev) 2095 { 2096 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2097 2098 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2099 2100 xennet_disconnect_backend(info); 2101 2102 unregister_netdev(info->netdev); 2103 2104 xennet_destroy_queues(info); 2105 xennet_free_netdev(info->netdev); 2106 2107 return 0; 2108 } 2109 2110 static const struct xenbus_device_id netfront_ids[] = { 2111 { "vif" }, 2112 { "" } 2113 }; 2114 2115 static struct xenbus_driver netfront_driver = { 2116 .ids = netfront_ids, 2117 .probe = netfront_probe, 2118 .remove = xennet_remove, 2119 .resume = netfront_resume, 2120 .otherend_changed = netback_changed, 2121 }; 2122 2123 static int __init netif_init(void) 2124 { 2125 if (!xen_domain()) 2126 return -ENODEV; 2127 2128 if (!xen_has_pv_nic_devices()) 2129 return -ENODEV; 2130 2131 pr_info("Initialising Xen virtual ethernet driver\n"); 2132 2133 /* Allow as many queues as there are CPUs, by default */ 2134 xennet_max_queues = num_online_cpus(); 2135 2136 return xenbus_register_frontend(&netfront_driver); 2137 } 2138 module_init(netif_init); 2139 2140 2141 static void __exit netif_exit(void) 2142 { 2143 xenbus_unregister_driver(&netfront_driver); 2144 } 2145 module_exit(netif_exit); 2146 2147 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2148 MODULE_LICENSE("GPL"); 2149 MODULE_ALIAS("xen:vif"); 2150 MODULE_ALIAS("xennet"); 2151