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