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