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 unsigned long flags; 981 int err; 982 983 spin_lock(&queue->rx_lock); 984 985 skb_queue_head_init(&rxq); 986 skb_queue_head_init(&errq); 987 skb_queue_head_init(&tmpq); 988 989 rp = queue->rx.sring->rsp_prod; 990 rmb(); /* Ensure we see queued responses up to 'rp'. */ 991 992 i = queue->rx.rsp_cons; 993 work_done = 0; 994 while ((i != rp) && (work_done < budget)) { 995 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 996 memset(extras, 0, sizeof(rinfo.extras)); 997 998 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 999 1000 if (unlikely(err)) { 1001 err: 1002 while ((skb = __skb_dequeue(&tmpq))) 1003 __skb_queue_tail(&errq, skb); 1004 dev->stats.rx_errors++; 1005 i = queue->rx.rsp_cons; 1006 continue; 1007 } 1008 1009 skb = __skb_dequeue(&tmpq); 1010 1011 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1012 struct xen_netif_extra_info *gso; 1013 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1014 1015 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1016 __skb_queue_head(&tmpq, skb); 1017 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1018 goto err; 1019 } 1020 } 1021 1022 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1023 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1024 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1025 1026 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1027 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1028 skb->data_len = rx->status; 1029 skb->len += rx->status; 1030 1031 i = xennet_fill_frags(queue, skb, &tmpq); 1032 1033 if (rx->flags & XEN_NETRXF_csum_blank) 1034 skb->ip_summed = CHECKSUM_PARTIAL; 1035 else if (rx->flags & XEN_NETRXF_data_validated) 1036 skb->ip_summed = CHECKSUM_UNNECESSARY; 1037 1038 __skb_queue_tail(&rxq, skb); 1039 1040 queue->rx.rsp_cons = ++i; 1041 work_done++; 1042 } 1043 1044 __skb_queue_purge(&errq); 1045 1046 work_done -= handle_incoming_queue(queue, &rxq); 1047 1048 xennet_alloc_rx_buffers(queue); 1049 1050 if (work_done < budget) { 1051 int more_to_do = 0; 1052 1053 napi_gro_flush(napi, false); 1054 1055 local_irq_save(flags); 1056 1057 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1058 if (!more_to_do) 1059 __napi_complete(napi); 1060 1061 local_irq_restore(flags); 1062 } 1063 1064 spin_unlock(&queue->rx_lock); 1065 1066 return work_done; 1067 } 1068 1069 static int xennet_change_mtu(struct net_device *dev, int mtu) 1070 { 1071 int max = xennet_can_sg(dev) ? 1072 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; 1073 1074 if (mtu > max) 1075 return -EINVAL; 1076 dev->mtu = mtu; 1077 return 0; 1078 } 1079 1080 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, 1081 struct rtnl_link_stats64 *tot) 1082 { 1083 struct netfront_info *np = netdev_priv(dev); 1084 int cpu; 1085 1086 for_each_possible_cpu(cpu) { 1087 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu); 1088 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1089 unsigned int start; 1090 1091 do { 1092 start = u64_stats_fetch_begin_irq(&stats->syncp); 1093 1094 rx_packets = stats->rx_packets; 1095 tx_packets = stats->tx_packets; 1096 rx_bytes = stats->rx_bytes; 1097 tx_bytes = stats->tx_bytes; 1098 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 1099 1100 tot->rx_packets += rx_packets; 1101 tot->tx_packets += tx_packets; 1102 tot->rx_bytes += rx_bytes; 1103 tot->tx_bytes += tx_bytes; 1104 } 1105 1106 tot->rx_errors = dev->stats.rx_errors; 1107 tot->tx_dropped = dev->stats.tx_dropped; 1108 1109 return tot; 1110 } 1111 1112 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1113 { 1114 struct sk_buff *skb; 1115 int i; 1116 1117 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1118 /* Skip over entries which are actually freelist references */ 1119 if (skb_entry_is_link(&queue->tx_skbs[i])) 1120 continue; 1121 1122 skb = queue->tx_skbs[i].skb; 1123 get_page(queue->grant_tx_page[i]); 1124 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1125 GNTMAP_readonly, 1126 (unsigned long)page_address(queue->grant_tx_page[i])); 1127 queue->grant_tx_page[i] = NULL; 1128 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1129 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1130 dev_kfree_skb_irq(skb); 1131 } 1132 } 1133 1134 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1135 { 1136 int id, ref; 1137 1138 spin_lock_bh(&queue->rx_lock); 1139 1140 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1141 struct sk_buff *skb; 1142 struct page *page; 1143 1144 skb = queue->rx_skbs[id]; 1145 if (!skb) 1146 continue; 1147 1148 ref = queue->grant_rx_ref[id]; 1149 if (ref == GRANT_INVALID_REF) 1150 continue; 1151 1152 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1153 1154 /* gnttab_end_foreign_access() needs a page ref until 1155 * foreign access is ended (which may be deferred). 1156 */ 1157 get_page(page); 1158 gnttab_end_foreign_access(ref, 0, 1159 (unsigned long)page_address(page)); 1160 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1161 1162 kfree_skb(skb); 1163 } 1164 1165 spin_unlock_bh(&queue->rx_lock); 1166 } 1167 1168 static netdev_features_t xennet_fix_features(struct net_device *dev, 1169 netdev_features_t features) 1170 { 1171 struct netfront_info *np = netdev_priv(dev); 1172 int val; 1173 1174 if (features & NETIF_F_SG) { 1175 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1176 "%d", &val) < 0) 1177 val = 0; 1178 1179 if (!val) 1180 features &= ~NETIF_F_SG; 1181 } 1182 1183 if (features & NETIF_F_IPV6_CSUM) { 1184 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1185 "feature-ipv6-csum-offload", "%d", &val) < 0) 1186 val = 0; 1187 1188 if (!val) 1189 features &= ~NETIF_F_IPV6_CSUM; 1190 } 1191 1192 if (features & NETIF_F_TSO) { 1193 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1194 "feature-gso-tcpv4", "%d", &val) < 0) 1195 val = 0; 1196 1197 if (!val) 1198 features &= ~NETIF_F_TSO; 1199 } 1200 1201 if (features & NETIF_F_TSO6) { 1202 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1203 "feature-gso-tcpv6", "%d", &val) < 0) 1204 val = 0; 1205 1206 if (!val) 1207 features &= ~NETIF_F_TSO6; 1208 } 1209 1210 return features; 1211 } 1212 1213 static int xennet_set_features(struct net_device *dev, 1214 netdev_features_t features) 1215 { 1216 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1217 netdev_info(dev, "Reducing MTU because no SG offload"); 1218 dev->mtu = ETH_DATA_LEN; 1219 } 1220 1221 return 0; 1222 } 1223 1224 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1225 { 1226 struct netfront_queue *queue = dev_id; 1227 unsigned long flags; 1228 1229 spin_lock_irqsave(&queue->tx_lock, flags); 1230 xennet_tx_buf_gc(queue); 1231 spin_unlock_irqrestore(&queue->tx_lock, flags); 1232 1233 return IRQ_HANDLED; 1234 } 1235 1236 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1237 { 1238 struct netfront_queue *queue = dev_id; 1239 struct net_device *dev = queue->info->netdev; 1240 1241 if (likely(netif_carrier_ok(dev) && 1242 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1243 napi_schedule(&queue->napi); 1244 1245 return IRQ_HANDLED; 1246 } 1247 1248 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1249 { 1250 xennet_tx_interrupt(irq, dev_id); 1251 xennet_rx_interrupt(irq, dev_id); 1252 return IRQ_HANDLED; 1253 } 1254 1255 #ifdef CONFIG_NET_POLL_CONTROLLER 1256 static void xennet_poll_controller(struct net_device *dev) 1257 { 1258 /* Poll each queue */ 1259 struct netfront_info *info = netdev_priv(dev); 1260 unsigned int num_queues = dev->real_num_tx_queues; 1261 unsigned int i; 1262 for (i = 0; i < num_queues; ++i) 1263 xennet_interrupt(0, &info->queues[i]); 1264 } 1265 #endif 1266 1267 static const struct net_device_ops xennet_netdev_ops = { 1268 .ndo_open = xennet_open, 1269 .ndo_stop = xennet_close, 1270 .ndo_start_xmit = xennet_start_xmit, 1271 .ndo_change_mtu = xennet_change_mtu, 1272 .ndo_get_stats64 = xennet_get_stats64, 1273 .ndo_set_mac_address = eth_mac_addr, 1274 .ndo_validate_addr = eth_validate_addr, 1275 .ndo_fix_features = xennet_fix_features, 1276 .ndo_set_features = xennet_set_features, 1277 .ndo_select_queue = xennet_select_queue, 1278 #ifdef CONFIG_NET_POLL_CONTROLLER 1279 .ndo_poll_controller = xennet_poll_controller, 1280 #endif 1281 }; 1282 1283 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1284 { 1285 int err; 1286 struct net_device *netdev; 1287 struct netfront_info *np; 1288 1289 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1290 if (!netdev) 1291 return ERR_PTR(-ENOMEM); 1292 1293 np = netdev_priv(netdev); 1294 np->xbdev = dev; 1295 1296 /* No need to use rtnl_lock() before the call below as it 1297 * happens before register_netdev(). 1298 */ 1299 netif_set_real_num_tx_queues(netdev, 0); 1300 np->queues = NULL; 1301 1302 err = -ENOMEM; 1303 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1304 if (np->stats == NULL) 1305 goto exit; 1306 1307 netdev->netdev_ops = &xennet_netdev_ops; 1308 1309 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1310 NETIF_F_GSO_ROBUST; 1311 netdev->hw_features = NETIF_F_SG | 1312 NETIF_F_IPV6_CSUM | 1313 NETIF_F_TSO | NETIF_F_TSO6; 1314 1315 /* 1316 * Assume that all hw features are available for now. This set 1317 * will be adjusted by the call to netdev_update_features() in 1318 * xennet_connect() which is the earliest point where we can 1319 * negotiate with the backend regarding supported features. 1320 */ 1321 netdev->features |= netdev->hw_features; 1322 1323 netdev->ethtool_ops = &xennet_ethtool_ops; 1324 SET_NETDEV_DEV(netdev, &dev->dev); 1325 1326 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); 1327 1328 np->netdev = netdev; 1329 1330 netif_carrier_off(netdev); 1331 1332 return netdev; 1333 1334 exit: 1335 free_netdev(netdev); 1336 return ERR_PTR(err); 1337 } 1338 1339 /** 1340 * Entry point to this code when a new device is created. Allocate the basic 1341 * structures and the ring buffers for communication with the backend, and 1342 * inform the backend of the appropriate details for those. 1343 */ 1344 static int netfront_probe(struct xenbus_device *dev, 1345 const struct xenbus_device_id *id) 1346 { 1347 int err; 1348 struct net_device *netdev; 1349 struct netfront_info *info; 1350 1351 netdev = xennet_create_dev(dev); 1352 if (IS_ERR(netdev)) { 1353 err = PTR_ERR(netdev); 1354 xenbus_dev_fatal(dev, err, "creating netdev"); 1355 return err; 1356 } 1357 1358 info = netdev_priv(netdev); 1359 dev_set_drvdata(&dev->dev, info); 1360 1361 err = register_netdev(info->netdev); 1362 if (err) { 1363 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1364 goto fail; 1365 } 1366 1367 err = xennet_sysfs_addif(info->netdev); 1368 if (err) { 1369 unregister_netdev(info->netdev); 1370 pr_warn("%s: add sysfs failed err=%d\n", __func__, err); 1371 goto fail; 1372 } 1373 1374 return 0; 1375 1376 fail: 1377 free_netdev(netdev); 1378 dev_set_drvdata(&dev->dev, NULL); 1379 return err; 1380 } 1381 1382 static void xennet_end_access(int ref, void *page) 1383 { 1384 /* This frees the page as a side-effect */ 1385 if (ref != GRANT_INVALID_REF) 1386 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1387 } 1388 1389 static void xennet_disconnect_backend(struct netfront_info *info) 1390 { 1391 unsigned int i = 0; 1392 unsigned int num_queues = info->netdev->real_num_tx_queues; 1393 1394 netif_carrier_off(info->netdev); 1395 1396 for (i = 0; i < num_queues; ++i) { 1397 struct netfront_queue *queue = &info->queues[i]; 1398 1399 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1400 unbind_from_irqhandler(queue->tx_irq, queue); 1401 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1402 unbind_from_irqhandler(queue->tx_irq, queue); 1403 unbind_from_irqhandler(queue->rx_irq, queue); 1404 } 1405 queue->tx_evtchn = queue->rx_evtchn = 0; 1406 queue->tx_irq = queue->rx_irq = 0; 1407 1408 napi_synchronize(&queue->napi); 1409 1410 xennet_release_tx_bufs(queue); 1411 xennet_release_rx_bufs(queue); 1412 gnttab_free_grant_references(queue->gref_tx_head); 1413 gnttab_free_grant_references(queue->gref_rx_head); 1414 1415 /* End access and free the pages */ 1416 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1417 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1418 1419 queue->tx_ring_ref = GRANT_INVALID_REF; 1420 queue->rx_ring_ref = GRANT_INVALID_REF; 1421 queue->tx.sring = NULL; 1422 queue->rx.sring = NULL; 1423 } 1424 } 1425 1426 /** 1427 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1428 * driver restart. We tear down our netif structure and recreate it, but 1429 * leave the device-layer structures intact so that this is transparent to the 1430 * rest of the kernel. 1431 */ 1432 static int netfront_resume(struct xenbus_device *dev) 1433 { 1434 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1435 1436 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1437 1438 xennet_disconnect_backend(info); 1439 return 0; 1440 } 1441 1442 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1443 { 1444 char *s, *e, *macstr; 1445 int i; 1446 1447 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1448 if (IS_ERR(macstr)) 1449 return PTR_ERR(macstr); 1450 1451 for (i = 0; i < ETH_ALEN; i++) { 1452 mac[i] = simple_strtoul(s, &e, 16); 1453 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1454 kfree(macstr); 1455 return -ENOENT; 1456 } 1457 s = e+1; 1458 } 1459 1460 kfree(macstr); 1461 return 0; 1462 } 1463 1464 static int setup_netfront_single(struct netfront_queue *queue) 1465 { 1466 int err; 1467 1468 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1469 if (err < 0) 1470 goto fail; 1471 1472 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1473 xennet_interrupt, 1474 0, queue->info->netdev->name, queue); 1475 if (err < 0) 1476 goto bind_fail; 1477 queue->rx_evtchn = queue->tx_evtchn; 1478 queue->rx_irq = queue->tx_irq = err; 1479 1480 return 0; 1481 1482 bind_fail: 1483 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1484 queue->tx_evtchn = 0; 1485 fail: 1486 return err; 1487 } 1488 1489 static int setup_netfront_split(struct netfront_queue *queue) 1490 { 1491 int err; 1492 1493 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1494 if (err < 0) 1495 goto fail; 1496 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1497 if (err < 0) 1498 goto alloc_rx_evtchn_fail; 1499 1500 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1501 "%s-tx", queue->name); 1502 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1503 xennet_tx_interrupt, 1504 0, queue->tx_irq_name, queue); 1505 if (err < 0) 1506 goto bind_tx_fail; 1507 queue->tx_irq = err; 1508 1509 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1510 "%s-rx", queue->name); 1511 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1512 xennet_rx_interrupt, 1513 0, queue->rx_irq_name, queue); 1514 if (err < 0) 1515 goto bind_rx_fail; 1516 queue->rx_irq = err; 1517 1518 return 0; 1519 1520 bind_rx_fail: 1521 unbind_from_irqhandler(queue->tx_irq, queue); 1522 queue->tx_irq = 0; 1523 bind_tx_fail: 1524 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1525 queue->rx_evtchn = 0; 1526 alloc_rx_evtchn_fail: 1527 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1528 queue->tx_evtchn = 0; 1529 fail: 1530 return err; 1531 } 1532 1533 static int setup_netfront(struct xenbus_device *dev, 1534 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1535 { 1536 struct xen_netif_tx_sring *txs; 1537 struct xen_netif_rx_sring *rxs; 1538 int err; 1539 1540 queue->tx_ring_ref = GRANT_INVALID_REF; 1541 queue->rx_ring_ref = GRANT_INVALID_REF; 1542 queue->rx.sring = NULL; 1543 queue->tx.sring = NULL; 1544 1545 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1546 if (!txs) { 1547 err = -ENOMEM; 1548 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1549 goto fail; 1550 } 1551 SHARED_RING_INIT(txs); 1552 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE); 1553 1554 err = xenbus_grant_ring(dev, virt_to_mfn(txs)); 1555 if (err < 0) 1556 goto grant_tx_ring_fail; 1557 queue->tx_ring_ref = err; 1558 1559 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1560 if (!rxs) { 1561 err = -ENOMEM; 1562 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1563 goto alloc_rx_ring_fail; 1564 } 1565 SHARED_RING_INIT(rxs); 1566 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE); 1567 1568 err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); 1569 if (err < 0) 1570 goto grant_rx_ring_fail; 1571 queue->rx_ring_ref = err; 1572 1573 if (feature_split_evtchn) 1574 err = setup_netfront_split(queue); 1575 /* setup single event channel if 1576 * a) feature-split-event-channels == 0 1577 * b) feature-split-event-channels == 1 but failed to setup 1578 */ 1579 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1580 err = setup_netfront_single(queue); 1581 1582 if (err) 1583 goto alloc_evtchn_fail; 1584 1585 return 0; 1586 1587 /* If we fail to setup netfront, it is safe to just revoke access to 1588 * granted pages because backend is not accessing it at this point. 1589 */ 1590 alloc_evtchn_fail: 1591 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1592 grant_rx_ring_fail: 1593 free_page((unsigned long)rxs); 1594 alloc_rx_ring_fail: 1595 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1596 grant_tx_ring_fail: 1597 free_page((unsigned long)txs); 1598 fail: 1599 return err; 1600 } 1601 1602 /* Queue-specific initialisation 1603 * This used to be done in xennet_create_dev() but must now 1604 * be run per-queue. 1605 */ 1606 static int xennet_init_queue(struct netfront_queue *queue) 1607 { 1608 unsigned short i; 1609 int err = 0; 1610 1611 spin_lock_init(&queue->tx_lock); 1612 spin_lock_init(&queue->rx_lock); 1613 1614 init_timer(&queue->rx_refill_timer); 1615 queue->rx_refill_timer.data = (unsigned long)queue; 1616 queue->rx_refill_timer.function = rx_refill_timeout; 1617 1618 snprintf(queue->name, sizeof(queue->name), "%s-q%u", 1619 queue->info->netdev->name, queue->id); 1620 1621 /* Initialise tx_skbs as a free chain containing every entry. */ 1622 queue->tx_skb_freelist = 0; 1623 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1624 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1625 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1626 queue->grant_tx_page[i] = NULL; 1627 } 1628 1629 /* Clear out rx_skbs */ 1630 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1631 queue->rx_skbs[i] = NULL; 1632 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1633 } 1634 1635 /* A grant for every tx ring slot */ 1636 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1637 &queue->gref_tx_head) < 0) { 1638 pr_alert("can't alloc tx grant refs\n"); 1639 err = -ENOMEM; 1640 goto exit; 1641 } 1642 1643 /* A grant for every rx ring slot */ 1644 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1645 &queue->gref_rx_head) < 0) { 1646 pr_alert("can't alloc rx grant refs\n"); 1647 err = -ENOMEM; 1648 goto exit_free_tx; 1649 } 1650 1651 return 0; 1652 1653 exit_free_tx: 1654 gnttab_free_grant_references(queue->gref_tx_head); 1655 exit: 1656 return err; 1657 } 1658 1659 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1660 struct xenbus_transaction *xbt, int write_hierarchical) 1661 { 1662 /* Write the queue-specific keys into XenStore in the traditional 1663 * way for a single queue, or in a queue subkeys for multiple 1664 * queues. 1665 */ 1666 struct xenbus_device *dev = queue->info->xbdev; 1667 int err; 1668 const char *message; 1669 char *path; 1670 size_t pathsize; 1671 1672 /* Choose the correct place to write the keys */ 1673 if (write_hierarchical) { 1674 pathsize = strlen(dev->nodename) + 10; 1675 path = kzalloc(pathsize, GFP_KERNEL); 1676 if (!path) { 1677 err = -ENOMEM; 1678 message = "out of memory while writing ring references"; 1679 goto error; 1680 } 1681 snprintf(path, pathsize, "%s/queue-%u", 1682 dev->nodename, queue->id); 1683 } else { 1684 path = (char *)dev->nodename; 1685 } 1686 1687 /* Write ring references */ 1688 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1689 queue->tx_ring_ref); 1690 if (err) { 1691 message = "writing tx-ring-ref"; 1692 goto error; 1693 } 1694 1695 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1696 queue->rx_ring_ref); 1697 if (err) { 1698 message = "writing rx-ring-ref"; 1699 goto error; 1700 } 1701 1702 /* Write event channels; taking into account both shared 1703 * and split event channel scenarios. 1704 */ 1705 if (queue->tx_evtchn == queue->rx_evtchn) { 1706 /* Shared event channel */ 1707 err = xenbus_printf(*xbt, path, 1708 "event-channel", "%u", queue->tx_evtchn); 1709 if (err) { 1710 message = "writing event-channel"; 1711 goto error; 1712 } 1713 } else { 1714 /* Split event channels */ 1715 err = xenbus_printf(*xbt, path, 1716 "event-channel-tx", "%u", queue->tx_evtchn); 1717 if (err) { 1718 message = "writing event-channel-tx"; 1719 goto error; 1720 } 1721 1722 err = xenbus_printf(*xbt, path, 1723 "event-channel-rx", "%u", queue->rx_evtchn); 1724 if (err) { 1725 message = "writing event-channel-rx"; 1726 goto error; 1727 } 1728 } 1729 1730 if (write_hierarchical) 1731 kfree(path); 1732 return 0; 1733 1734 error: 1735 if (write_hierarchical) 1736 kfree(path); 1737 xenbus_dev_fatal(dev, err, "%s", message); 1738 return err; 1739 } 1740 1741 static void xennet_destroy_queues(struct netfront_info *info) 1742 { 1743 unsigned int i; 1744 1745 rtnl_lock(); 1746 1747 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1748 struct netfront_queue *queue = &info->queues[i]; 1749 1750 if (netif_running(info->netdev)) 1751 napi_disable(&queue->napi); 1752 netif_napi_del(&queue->napi); 1753 } 1754 1755 rtnl_unlock(); 1756 1757 kfree(info->queues); 1758 info->queues = NULL; 1759 } 1760 1761 static int xennet_create_queues(struct netfront_info *info, 1762 unsigned int num_queues) 1763 { 1764 unsigned int i; 1765 int ret; 1766 1767 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue), 1768 GFP_KERNEL); 1769 if (!info->queues) 1770 return -ENOMEM; 1771 1772 rtnl_lock(); 1773 1774 for (i = 0; i < num_queues; i++) { 1775 struct netfront_queue *queue = &info->queues[i]; 1776 1777 queue->id = i; 1778 queue->info = info; 1779 1780 ret = xennet_init_queue(queue); 1781 if (ret < 0) { 1782 dev_warn(&info->netdev->dev, 1783 "only created %d queues\n", i); 1784 num_queues = i; 1785 break; 1786 } 1787 1788 netif_napi_add(queue->info->netdev, &queue->napi, 1789 xennet_poll, 64); 1790 if (netif_running(info->netdev)) 1791 napi_enable(&queue->napi); 1792 } 1793 1794 netif_set_real_num_tx_queues(info->netdev, num_queues); 1795 1796 rtnl_unlock(); 1797 1798 if (num_queues == 0) { 1799 dev_err(&info->netdev->dev, "no queues\n"); 1800 return -EINVAL; 1801 } 1802 return 0; 1803 } 1804 1805 /* Common code used when first setting up, and when resuming. */ 1806 static int talk_to_netback(struct xenbus_device *dev, 1807 struct netfront_info *info) 1808 { 1809 const char *message; 1810 struct xenbus_transaction xbt; 1811 int err; 1812 unsigned int feature_split_evtchn; 1813 unsigned int i = 0; 1814 unsigned int max_queues = 0; 1815 struct netfront_queue *queue = NULL; 1816 unsigned int num_queues = 1; 1817 1818 info->netdev->irq = 0; 1819 1820 /* Check if backend supports multiple queues */ 1821 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1822 "multi-queue-max-queues", "%u", &max_queues); 1823 if (err < 0) 1824 max_queues = 1; 1825 num_queues = min(max_queues, xennet_max_queues); 1826 1827 /* Check feature-split-event-channels */ 1828 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1829 "feature-split-event-channels", "%u", 1830 &feature_split_evtchn); 1831 if (err < 0) 1832 feature_split_evtchn = 0; 1833 1834 /* Read mac addr. */ 1835 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1836 if (err) { 1837 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1838 goto out; 1839 } 1840 1841 if (info->queues) 1842 xennet_destroy_queues(info); 1843 1844 err = xennet_create_queues(info, num_queues); 1845 if (err < 0) 1846 goto destroy_ring; 1847 1848 /* Create shared ring, alloc event channel -- for each queue */ 1849 for (i = 0; i < num_queues; ++i) { 1850 queue = &info->queues[i]; 1851 err = setup_netfront(dev, queue, feature_split_evtchn); 1852 if (err) { 1853 /* setup_netfront() will tidy up the current 1854 * queue on error, but we need to clean up 1855 * those already allocated. 1856 */ 1857 if (i > 0) { 1858 rtnl_lock(); 1859 netif_set_real_num_tx_queues(info->netdev, i); 1860 rtnl_unlock(); 1861 goto destroy_ring; 1862 } else { 1863 goto out; 1864 } 1865 } 1866 } 1867 1868 again: 1869 err = xenbus_transaction_start(&xbt); 1870 if (err) { 1871 xenbus_dev_fatal(dev, err, "starting transaction"); 1872 goto destroy_ring; 1873 } 1874 1875 if (num_queues == 1) { 1876 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1877 if (err) 1878 goto abort_transaction_no_dev_fatal; 1879 } else { 1880 /* Write the number of queues */ 1881 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", 1882 "%u", num_queues); 1883 if (err) { 1884 message = "writing multi-queue-num-queues"; 1885 goto abort_transaction_no_dev_fatal; 1886 } 1887 1888 /* Write the keys for each queue */ 1889 for (i = 0; i < num_queues; ++i) { 1890 queue = &info->queues[i]; 1891 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1892 if (err) 1893 goto abort_transaction_no_dev_fatal; 1894 } 1895 } 1896 1897 /* The remaining keys are not queue-specific */ 1898 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1899 1); 1900 if (err) { 1901 message = "writing request-rx-copy"; 1902 goto abort_transaction; 1903 } 1904 1905 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1906 if (err) { 1907 message = "writing feature-rx-notify"; 1908 goto abort_transaction; 1909 } 1910 1911 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1912 if (err) { 1913 message = "writing feature-sg"; 1914 goto abort_transaction; 1915 } 1916 1917 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1918 if (err) { 1919 message = "writing feature-gso-tcpv4"; 1920 goto abort_transaction; 1921 } 1922 1923 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1924 if (err) { 1925 message = "writing feature-gso-tcpv6"; 1926 goto abort_transaction; 1927 } 1928 1929 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1930 "1"); 1931 if (err) { 1932 message = "writing feature-ipv6-csum-offload"; 1933 goto abort_transaction; 1934 } 1935 1936 err = xenbus_transaction_end(xbt, 0); 1937 if (err) { 1938 if (err == -EAGAIN) 1939 goto again; 1940 xenbus_dev_fatal(dev, err, "completing transaction"); 1941 goto destroy_ring; 1942 } 1943 1944 return 0; 1945 1946 abort_transaction: 1947 xenbus_dev_fatal(dev, err, "%s", message); 1948 abort_transaction_no_dev_fatal: 1949 xenbus_transaction_end(xbt, 1); 1950 destroy_ring: 1951 xennet_disconnect_backend(info); 1952 kfree(info->queues); 1953 info->queues = NULL; 1954 rtnl_lock(); 1955 netif_set_real_num_tx_queues(info->netdev, 0); 1956 rtnl_unlock(); 1957 out: 1958 return err; 1959 } 1960 1961 static int xennet_connect(struct net_device *dev) 1962 { 1963 struct netfront_info *np = netdev_priv(dev); 1964 unsigned int num_queues = 0; 1965 int err; 1966 unsigned int feature_rx_copy; 1967 unsigned int j = 0; 1968 struct netfront_queue *queue = NULL; 1969 1970 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1971 "feature-rx-copy", "%u", &feature_rx_copy); 1972 if (err != 1) 1973 feature_rx_copy = 0; 1974 1975 if (!feature_rx_copy) { 1976 dev_info(&dev->dev, 1977 "backend does not support copying receive path\n"); 1978 return -ENODEV; 1979 } 1980 1981 err = talk_to_netback(np->xbdev, np); 1982 if (err) 1983 return err; 1984 1985 /* talk_to_netback() sets the correct number of queues */ 1986 num_queues = dev->real_num_tx_queues; 1987 1988 rtnl_lock(); 1989 netdev_update_features(dev); 1990 rtnl_unlock(); 1991 1992 /* 1993 * All public and private state should now be sane. Get 1994 * ready to start sending and receiving packets and give the driver 1995 * domain a kick because we've probably just requeued some 1996 * packets. 1997 */ 1998 netif_carrier_on(np->netdev); 1999 for (j = 0; j < num_queues; ++j) { 2000 queue = &np->queues[j]; 2001 2002 notify_remote_via_irq(queue->tx_irq); 2003 if (queue->tx_irq != queue->rx_irq) 2004 notify_remote_via_irq(queue->rx_irq); 2005 2006 spin_lock_irq(&queue->tx_lock); 2007 xennet_tx_buf_gc(queue); 2008 spin_unlock_irq(&queue->tx_lock); 2009 2010 spin_lock_bh(&queue->rx_lock); 2011 xennet_alloc_rx_buffers(queue); 2012 spin_unlock_bh(&queue->rx_lock); 2013 } 2014 2015 return 0; 2016 } 2017 2018 /** 2019 * Callback received when the backend's state changes. 2020 */ 2021 static void netback_changed(struct xenbus_device *dev, 2022 enum xenbus_state backend_state) 2023 { 2024 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2025 struct net_device *netdev = np->netdev; 2026 2027 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2028 2029 switch (backend_state) { 2030 case XenbusStateInitialising: 2031 case XenbusStateInitialised: 2032 case XenbusStateReconfiguring: 2033 case XenbusStateReconfigured: 2034 case XenbusStateUnknown: 2035 break; 2036 2037 case XenbusStateInitWait: 2038 if (dev->state != XenbusStateInitialising) 2039 break; 2040 if (xennet_connect(netdev) != 0) 2041 break; 2042 xenbus_switch_state(dev, XenbusStateConnected); 2043 break; 2044 2045 case XenbusStateConnected: 2046 netdev_notify_peers(netdev); 2047 break; 2048 2049 case XenbusStateClosed: 2050 if (dev->state == XenbusStateClosed) 2051 break; 2052 /* Missed the backend's CLOSING state -- fallthrough */ 2053 case XenbusStateClosing: 2054 xenbus_frontend_closed(dev); 2055 break; 2056 } 2057 } 2058 2059 static const struct xennet_stat { 2060 char name[ETH_GSTRING_LEN]; 2061 u16 offset; 2062 } xennet_stats[] = { 2063 { 2064 "rx_gso_checksum_fixup", 2065 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2066 }, 2067 }; 2068 2069 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2070 { 2071 switch (string_set) { 2072 case ETH_SS_STATS: 2073 return ARRAY_SIZE(xennet_stats); 2074 default: 2075 return -EINVAL; 2076 } 2077 } 2078 2079 static void xennet_get_ethtool_stats(struct net_device *dev, 2080 struct ethtool_stats *stats, u64 * data) 2081 { 2082 void *np = netdev_priv(dev); 2083 int i; 2084 2085 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2086 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2087 } 2088 2089 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2090 { 2091 int i; 2092 2093 switch (stringset) { 2094 case ETH_SS_STATS: 2095 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2096 memcpy(data + i * ETH_GSTRING_LEN, 2097 xennet_stats[i].name, ETH_GSTRING_LEN); 2098 break; 2099 } 2100 } 2101 2102 static const struct ethtool_ops xennet_ethtool_ops = 2103 { 2104 .get_link = ethtool_op_get_link, 2105 2106 .get_sset_count = xennet_get_sset_count, 2107 .get_ethtool_stats = xennet_get_ethtool_stats, 2108 .get_strings = xennet_get_strings, 2109 }; 2110 2111 #ifdef CONFIG_SYSFS 2112 static ssize_t show_rxbuf(struct device *dev, 2113 struct device_attribute *attr, char *buf) 2114 { 2115 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2116 } 2117 2118 static ssize_t store_rxbuf(struct device *dev, 2119 struct device_attribute *attr, 2120 const char *buf, size_t len) 2121 { 2122 char *endp; 2123 unsigned long target; 2124 2125 if (!capable(CAP_NET_ADMIN)) 2126 return -EPERM; 2127 2128 target = simple_strtoul(buf, &endp, 0); 2129 if (endp == buf) 2130 return -EBADMSG; 2131 2132 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2133 2134 return len; 2135 } 2136 2137 static struct device_attribute xennet_attrs[] = { 2138 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf), 2139 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf), 2140 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL), 2141 }; 2142 2143 static int xennet_sysfs_addif(struct net_device *netdev) 2144 { 2145 int i; 2146 int err; 2147 2148 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { 2149 err = device_create_file(&netdev->dev, 2150 &xennet_attrs[i]); 2151 if (err) 2152 goto fail; 2153 } 2154 return 0; 2155 2156 fail: 2157 while (--i >= 0) 2158 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2159 return err; 2160 } 2161 2162 static void xennet_sysfs_delif(struct net_device *netdev) 2163 { 2164 int i; 2165 2166 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) 2167 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2168 } 2169 2170 #endif /* CONFIG_SYSFS */ 2171 2172 static int xennet_remove(struct xenbus_device *dev) 2173 { 2174 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2175 unsigned int num_queues = info->netdev->real_num_tx_queues; 2176 struct netfront_queue *queue = NULL; 2177 unsigned int i = 0; 2178 2179 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2180 2181 xennet_disconnect_backend(info); 2182 2183 xennet_sysfs_delif(info->netdev); 2184 2185 unregister_netdev(info->netdev); 2186 2187 for (i = 0; i < num_queues; ++i) { 2188 queue = &info->queues[i]; 2189 del_timer_sync(&queue->rx_refill_timer); 2190 } 2191 2192 if (num_queues) { 2193 kfree(info->queues); 2194 info->queues = NULL; 2195 } 2196 2197 free_percpu(info->stats); 2198 2199 free_netdev(info->netdev); 2200 2201 return 0; 2202 } 2203 2204 static const struct xenbus_device_id netfront_ids[] = { 2205 { "vif" }, 2206 { "" } 2207 }; 2208 2209 static struct xenbus_driver netfront_driver = { 2210 .ids = netfront_ids, 2211 .probe = netfront_probe, 2212 .remove = xennet_remove, 2213 .resume = netfront_resume, 2214 .otherend_changed = netback_changed, 2215 }; 2216 2217 static int __init netif_init(void) 2218 { 2219 if (!xen_domain()) 2220 return -ENODEV; 2221 2222 if (!xen_has_pv_nic_devices()) 2223 return -ENODEV; 2224 2225 pr_info("Initialising Xen virtual ethernet driver\n"); 2226 2227 /* Allow as many queues as there are CPUs, by default */ 2228 xennet_max_queues = num_online_cpus(); 2229 2230 return xenbus_register_frontend(&netfront_driver); 2231 } 2232 module_init(netif_init); 2233 2234 2235 static void __exit netif_exit(void) 2236 { 2237 xenbus_unregister_driver(&netfront_driver); 2238 } 2239 module_exit(netif_exit); 2240 2241 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2242 MODULE_LICENSE("GPL"); 2243 MODULE_ALIAS("xen:vif"); 2244 MODULE_ALIAS("xennet"); 2245