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 #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256) 81 82 /* Queue name is interface name with "-qNNN" appended */ 83 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6) 84 85 /* IRQ name is queue name with "-tx" or "-rx" appended */ 86 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) 87 88 struct netfront_stats { 89 u64 rx_packets; 90 u64 tx_packets; 91 u64 rx_bytes; 92 u64 tx_bytes; 93 struct u64_stats_sync syncp; 94 }; 95 96 struct netfront_info; 97 98 struct netfront_queue { 99 unsigned int id; /* Queue ID, 0-based */ 100 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ 101 struct netfront_info *info; 102 103 struct napi_struct napi; 104 105 /* Split event channels support, tx_* == rx_* when using 106 * single event channel. 107 */ 108 unsigned int tx_evtchn, rx_evtchn; 109 unsigned int tx_irq, rx_irq; 110 /* Only used when split event channels support is enabled */ 111 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ 112 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ 113 114 spinlock_t tx_lock; 115 struct xen_netif_tx_front_ring tx; 116 int tx_ring_ref; 117 118 /* 119 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 120 * are linked from tx_skb_freelist through skb_entry.link. 121 * 122 * NB. Freelist index entries are always going to be less than 123 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 124 * greater than PAGE_OFFSET: we use this property to distinguish 125 * them. 126 */ 127 union skb_entry { 128 struct sk_buff *skb; 129 unsigned long link; 130 } tx_skbs[NET_TX_RING_SIZE]; 131 grant_ref_t gref_tx_head; 132 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 133 struct page *grant_tx_page[NET_TX_RING_SIZE]; 134 unsigned tx_skb_freelist; 135 136 spinlock_t rx_lock ____cacheline_aligned_in_smp; 137 struct xen_netif_rx_front_ring rx; 138 int rx_ring_ref; 139 140 /* Receive-ring batched refills. */ 141 #define RX_MIN_TARGET 8 142 #define RX_DFL_MIN_TARGET 64 143 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) 144 unsigned rx_min_target, rx_max_target, rx_target; 145 struct sk_buff_head rx_batch; 146 147 struct timer_list rx_refill_timer; 148 149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 150 grant_ref_t gref_rx_head; 151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 152 153 unsigned long rx_pfn_array[NET_RX_RING_SIZE]; 154 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; 155 struct mmu_update rx_mmu[NET_RX_RING_SIZE]; 156 }; 157 158 struct netfront_info { 159 struct list_head list; 160 struct net_device *netdev; 161 162 struct xenbus_device *xbdev; 163 164 /* Multi-queue support */ 165 struct netfront_queue *queues; 166 167 /* Statistics */ 168 struct netfront_stats __percpu *stats; 169 170 atomic_t rx_gso_checksum_fixup; 171 }; 172 173 struct netfront_rx_info { 174 struct xen_netif_rx_response rx; 175 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 176 }; 177 178 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 179 { 180 list->link = id; 181 } 182 183 static int skb_entry_is_link(const union skb_entry *list) 184 { 185 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 186 return (unsigned long)list->skb < PAGE_OFFSET; 187 } 188 189 /* 190 * Access macros for acquiring freeing slots in tx_skbs[]. 191 */ 192 193 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 194 unsigned short id) 195 { 196 skb_entry_set_link(&list[id], *head); 197 *head = id; 198 } 199 200 static unsigned short get_id_from_freelist(unsigned *head, 201 union skb_entry *list) 202 { 203 unsigned int id = *head; 204 *head = list[id].link; 205 return id; 206 } 207 208 static int xennet_rxidx(RING_IDX idx) 209 { 210 return idx & (NET_RX_RING_SIZE - 1); 211 } 212 213 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, 214 RING_IDX ri) 215 { 216 int i = xennet_rxidx(ri); 217 struct sk_buff *skb = queue->rx_skbs[i]; 218 queue->rx_skbs[i] = NULL; 219 return skb; 220 } 221 222 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, 223 RING_IDX ri) 224 { 225 int i = xennet_rxidx(ri); 226 grant_ref_t ref = queue->grant_rx_ref[i]; 227 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 228 return ref; 229 } 230 231 #ifdef CONFIG_SYSFS 232 static int xennet_sysfs_addif(struct net_device *netdev); 233 static void xennet_sysfs_delif(struct net_device *netdev); 234 #else /* !CONFIG_SYSFS */ 235 #define xennet_sysfs_addif(dev) (0) 236 #define xennet_sysfs_delif(dev) do { } while (0) 237 #endif 238 239 static bool xennet_can_sg(struct net_device *dev) 240 { 241 return dev->features & NETIF_F_SG; 242 } 243 244 245 static void rx_refill_timeout(unsigned long data) 246 { 247 struct netfront_queue *queue = (struct netfront_queue *)data; 248 napi_schedule(&queue->napi); 249 } 250 251 static int netfront_tx_slot_available(struct netfront_queue *queue) 252 { 253 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < 254 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2); 255 } 256 257 static void xennet_maybe_wake_tx(struct netfront_queue *queue) 258 { 259 struct net_device *dev = queue->info->netdev; 260 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); 261 262 if (unlikely(netif_tx_queue_stopped(dev_queue)) && 263 netfront_tx_slot_available(queue) && 264 likely(netif_running(dev))) 265 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); 266 } 267 268 static void xennet_alloc_rx_buffers(struct netfront_queue *queue) 269 { 270 unsigned short id; 271 struct sk_buff *skb; 272 struct page *page; 273 int i, batch_target, notify; 274 RING_IDX req_prod = queue->rx.req_prod_pvt; 275 grant_ref_t ref; 276 unsigned long pfn; 277 void *vaddr; 278 struct xen_netif_rx_request *req; 279 280 if (unlikely(!netif_carrier_ok(queue->info->netdev))) 281 return; 282 283 /* 284 * Allocate skbuffs greedily, even though we batch updates to the 285 * receive ring. This creates a less bursty demand on the memory 286 * allocator, so should reduce the chance of failed allocation requests 287 * both for ourself and for other kernel subsystems. 288 */ 289 batch_target = queue->rx_target - (req_prod - queue->rx.rsp_cons); 290 for (i = skb_queue_len(&queue->rx_batch); i < batch_target; i++) { 291 skb = __netdev_alloc_skb(queue->info->netdev, 292 RX_COPY_THRESHOLD + NET_IP_ALIGN, 293 GFP_ATOMIC | __GFP_NOWARN); 294 if (unlikely(!skb)) 295 goto no_skb; 296 297 /* Align ip header to a 16 bytes boundary */ 298 skb_reserve(skb, NET_IP_ALIGN); 299 300 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 301 if (!page) { 302 kfree_skb(skb); 303 no_skb: 304 /* Could not allocate any skbuffs. Try again later. */ 305 mod_timer(&queue->rx_refill_timer, 306 jiffies + (HZ/10)); 307 308 /* Any skbuffs queued for refill? Force them out. */ 309 if (i != 0) 310 goto refill; 311 break; 312 } 313 314 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 315 __skb_queue_tail(&queue->rx_batch, skb); 316 } 317 318 /* Is the batch large enough to be worthwhile? */ 319 if (i < (queue->rx_target/2)) { 320 if (req_prod > queue->rx.sring->req_prod) 321 goto push; 322 return; 323 } 324 325 /* Adjust our fill target if we risked running out of buffers. */ 326 if (((req_prod - queue->rx.sring->rsp_prod) < (queue->rx_target / 4)) && 327 ((queue->rx_target *= 2) > queue->rx_max_target)) 328 queue->rx_target = queue->rx_max_target; 329 330 refill: 331 for (i = 0; ; i++) { 332 skb = __skb_dequeue(&queue->rx_batch); 333 if (skb == NULL) 334 break; 335 336 skb->dev = queue->info->netdev; 337 338 id = xennet_rxidx(req_prod + i); 339 340 BUG_ON(queue->rx_skbs[id]); 341 queue->rx_skbs[id] = skb; 342 343 ref = gnttab_claim_grant_reference(&queue->gref_rx_head); 344 BUG_ON((signed short)ref < 0); 345 queue->grant_rx_ref[id] = ref; 346 347 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); 348 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0])); 349 350 req = RING_GET_REQUEST(&queue->rx, req_prod + i); 351 gnttab_grant_foreign_access_ref(ref, 352 queue->info->xbdev->otherend_id, 353 pfn_to_mfn(pfn), 354 0); 355 356 req->id = id; 357 req->gref = ref; 358 } 359 360 wmb(); /* barrier so backend seens requests */ 361 362 /* Above is a suitable barrier to ensure backend will see requests. */ 363 queue->rx.req_prod_pvt = req_prod + i; 364 push: 365 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 366 if (notify) 367 notify_remote_via_irq(queue->rx_irq); 368 } 369 370 static int xennet_open(struct net_device *dev) 371 { 372 struct netfront_info *np = netdev_priv(dev); 373 unsigned int num_queues = dev->real_num_tx_queues; 374 unsigned int i = 0; 375 struct netfront_queue *queue = NULL; 376 377 for (i = 0; i < num_queues; ++i) { 378 queue = &np->queues[i]; 379 napi_enable(&queue->napi); 380 381 spin_lock_bh(&queue->rx_lock); 382 if (netif_carrier_ok(dev)) { 383 xennet_alloc_rx_buffers(queue); 384 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 385 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 386 napi_schedule(&queue->napi); 387 } 388 spin_unlock_bh(&queue->rx_lock); 389 } 390 391 netif_tx_start_all_queues(dev); 392 393 return 0; 394 } 395 396 static void xennet_tx_buf_gc(struct netfront_queue *queue) 397 { 398 RING_IDX cons, prod; 399 unsigned short id; 400 struct sk_buff *skb; 401 402 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 403 404 do { 405 prod = queue->tx.sring->rsp_prod; 406 rmb(); /* Ensure we see responses up to 'rp'. */ 407 408 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 409 struct xen_netif_tx_response *txrsp; 410 411 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 412 if (txrsp->status == XEN_NETIF_RSP_NULL) 413 continue; 414 415 id = txrsp->id; 416 skb = queue->tx_skbs[id].skb; 417 if (unlikely(gnttab_query_foreign_access( 418 queue->grant_tx_ref[id]) != 0)) { 419 pr_alert("%s: warning -- grant still in use by backend domain\n", 420 __func__); 421 BUG(); 422 } 423 gnttab_end_foreign_access_ref( 424 queue->grant_tx_ref[id], GNTMAP_readonly); 425 gnttab_release_grant_reference( 426 &queue->gref_tx_head, queue->grant_tx_ref[id]); 427 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 428 queue->grant_tx_page[id] = NULL; 429 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 430 dev_kfree_skb_irq(skb); 431 } 432 433 queue->tx.rsp_cons = prod; 434 435 /* 436 * Set a new event, then check for race with update of tx_cons. 437 * Note that it is essential to schedule a callback, no matter 438 * how few buffers are pending. Even if there is space in the 439 * transmit ring, higher layers may be blocked because too much 440 * data is outstanding: in such cases notification from Xen is 441 * likely to be the only kick that we'll get. 442 */ 443 queue->tx.sring->rsp_event = 444 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1; 445 mb(); /* update shared area */ 446 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod)); 447 448 xennet_maybe_wake_tx(queue); 449 } 450 451 static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue, 452 struct xen_netif_tx_request *tx) 453 { 454 char *data = skb->data; 455 unsigned long mfn; 456 RING_IDX prod = queue->tx.req_prod_pvt; 457 int frags = skb_shinfo(skb)->nr_frags; 458 unsigned int offset = offset_in_page(data); 459 unsigned int len = skb_headlen(skb); 460 unsigned int id; 461 grant_ref_t ref; 462 int i; 463 464 /* While the header overlaps a page boundary (including being 465 larger than a page), split it it into page-sized chunks. */ 466 while (len > PAGE_SIZE - offset) { 467 tx->size = PAGE_SIZE - offset; 468 tx->flags |= XEN_NETTXF_more_data; 469 len -= tx->size; 470 data += tx->size; 471 offset = 0; 472 473 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 474 queue->tx_skbs[id].skb = skb_get(skb); 475 tx = RING_GET_REQUEST(&queue->tx, prod++); 476 tx->id = id; 477 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 478 BUG_ON((signed short)ref < 0); 479 480 mfn = virt_to_mfn(data); 481 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 482 mfn, GNTMAP_readonly); 483 484 queue->grant_tx_page[id] = virt_to_page(data); 485 tx->gref = queue->grant_tx_ref[id] = ref; 486 tx->offset = offset; 487 tx->size = len; 488 tx->flags = 0; 489 } 490 491 /* Grant backend access to each skb fragment page. */ 492 for (i = 0; i < frags; i++) { 493 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 494 struct page *page = skb_frag_page(frag); 495 496 len = skb_frag_size(frag); 497 offset = frag->page_offset; 498 499 /* Data must not cross a page boundary. */ 500 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); 501 502 /* Skip unused frames from start of page */ 503 page += offset >> PAGE_SHIFT; 504 offset &= ~PAGE_MASK; 505 506 while (len > 0) { 507 unsigned long bytes; 508 509 BUG_ON(offset >= PAGE_SIZE); 510 511 bytes = PAGE_SIZE - offset; 512 if (bytes > len) 513 bytes = len; 514 515 tx->flags |= XEN_NETTXF_more_data; 516 517 id = get_id_from_freelist(&queue->tx_skb_freelist, 518 queue->tx_skbs); 519 queue->tx_skbs[id].skb = skb_get(skb); 520 tx = RING_GET_REQUEST(&queue->tx, prod++); 521 tx->id = id; 522 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 523 BUG_ON((signed short)ref < 0); 524 525 mfn = pfn_to_mfn(page_to_pfn(page)); 526 gnttab_grant_foreign_access_ref(ref, 527 queue->info->xbdev->otherend_id, 528 mfn, GNTMAP_readonly); 529 530 queue->grant_tx_page[id] = page; 531 tx->gref = queue->grant_tx_ref[id] = ref; 532 tx->offset = offset; 533 tx->size = bytes; 534 tx->flags = 0; 535 536 offset += bytes; 537 len -= bytes; 538 539 /* Next frame */ 540 if (offset == PAGE_SIZE && len) { 541 BUG_ON(!PageCompound(page)); 542 page++; 543 offset = 0; 544 } 545 } 546 } 547 548 queue->tx.req_prod_pvt = prod; 549 } 550 551 /* 552 * Count how many ring slots are required to send the frags of this 553 * skb. Each frag might be a compound page. 554 */ 555 static int xennet_count_skb_frag_slots(struct sk_buff *skb) 556 { 557 int i, frags = skb_shinfo(skb)->nr_frags; 558 int pages = 0; 559 560 for (i = 0; i < frags; i++) { 561 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 562 unsigned long size = skb_frag_size(frag); 563 unsigned long offset = frag->page_offset; 564 565 /* Skip unused frames from start of page */ 566 offset &= ~PAGE_MASK; 567 568 pages += PFN_UP(offset + size); 569 } 570 571 return pages; 572 } 573 574 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 575 void *accel_priv, select_queue_fallback_t fallback) 576 { 577 unsigned int num_queues = dev->real_num_tx_queues; 578 u32 hash; 579 u16 queue_idx; 580 581 /* First, check if there is only one queue */ 582 if (num_queues == 1) { 583 queue_idx = 0; 584 } else { 585 hash = skb_get_hash(skb); 586 queue_idx = hash % num_queues; 587 } 588 589 return queue_idx; 590 } 591 592 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 593 { 594 unsigned short id; 595 struct netfront_info *np = netdev_priv(dev); 596 struct netfront_stats *stats = this_cpu_ptr(np->stats); 597 struct xen_netif_tx_request *tx; 598 char *data = skb->data; 599 RING_IDX i; 600 grant_ref_t ref; 601 unsigned long mfn; 602 int notify; 603 int slots; 604 unsigned int offset = offset_in_page(data); 605 unsigned int len = skb_headlen(skb); 606 unsigned long flags; 607 struct netfront_queue *queue = NULL; 608 unsigned int num_queues = dev->real_num_tx_queues; 609 u16 queue_index; 610 611 /* Drop the packet if no queues are set up */ 612 if (num_queues < 1) 613 goto drop; 614 /* Determine which queue to transmit this SKB on */ 615 queue_index = skb_get_queue_mapping(skb); 616 queue = &np->queues[queue_index]; 617 618 /* If skb->len is too big for wire format, drop skb and alert 619 * user about misconfiguration. 620 */ 621 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 622 net_alert_ratelimited( 623 "xennet: skb->len = %u, too big for wire format\n", 624 skb->len); 625 goto drop; 626 } 627 628 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + 629 xennet_count_skb_frag_slots(skb); 630 if (unlikely(slots > MAX_SKB_FRAGS + 1)) { 631 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 632 slots, skb->len); 633 if (skb_linearize(skb)) 634 goto drop; 635 } 636 637 spin_lock_irqsave(&queue->tx_lock, flags); 638 639 if (unlikely(!netif_carrier_ok(dev) || 640 (slots > 1 && !xennet_can_sg(dev)) || 641 netif_needs_gso(dev, skb, netif_skb_features(skb)))) { 642 spin_unlock_irqrestore(&queue->tx_lock, flags); 643 goto drop; 644 } 645 646 i = queue->tx.req_prod_pvt; 647 648 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 649 queue->tx_skbs[id].skb = skb; 650 651 tx = RING_GET_REQUEST(&queue->tx, i); 652 653 tx->id = id; 654 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 655 BUG_ON((signed short)ref < 0); 656 mfn = virt_to_mfn(data); 657 gnttab_grant_foreign_access_ref( 658 ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly); 659 queue->grant_tx_page[id] = virt_to_page(data); 660 tx->gref = queue->grant_tx_ref[id] = ref; 661 tx->offset = offset; 662 tx->size = len; 663 664 tx->flags = 0; 665 if (skb->ip_summed == CHECKSUM_PARTIAL) 666 /* local packet? */ 667 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 668 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 669 /* remote but checksummed. */ 670 tx->flags |= XEN_NETTXF_data_validated; 671 672 if (skb_shinfo(skb)->gso_size) { 673 struct xen_netif_extra_info *gso; 674 675 gso = (struct xen_netif_extra_info *) 676 RING_GET_REQUEST(&queue->tx, ++i); 677 678 tx->flags |= XEN_NETTXF_extra_info; 679 680 gso->u.gso.size = skb_shinfo(skb)->gso_size; 681 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 682 XEN_NETIF_GSO_TYPE_TCPV6 : 683 XEN_NETIF_GSO_TYPE_TCPV4; 684 gso->u.gso.pad = 0; 685 gso->u.gso.features = 0; 686 687 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 688 gso->flags = 0; 689 } 690 691 queue->tx.req_prod_pvt = i + 1; 692 693 xennet_make_frags(skb, queue, tx); 694 tx->size = skb->len; 695 696 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 697 if (notify) 698 notify_remote_via_irq(queue->tx_irq); 699 700 u64_stats_update_begin(&stats->syncp); 701 stats->tx_bytes += skb->len; 702 stats->tx_packets++; 703 u64_stats_update_end(&stats->syncp); 704 705 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 706 xennet_tx_buf_gc(queue); 707 708 if (!netfront_tx_slot_available(queue)) 709 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 710 711 spin_unlock_irqrestore(&queue->tx_lock, flags); 712 713 return NETDEV_TX_OK; 714 715 drop: 716 dev->stats.tx_dropped++; 717 dev_kfree_skb_any(skb); 718 return NETDEV_TX_OK; 719 } 720 721 static int xennet_close(struct net_device *dev) 722 { 723 struct netfront_info *np = netdev_priv(dev); 724 unsigned int num_queues = dev->real_num_tx_queues; 725 unsigned int i; 726 struct netfront_queue *queue; 727 netif_tx_stop_all_queues(np->netdev); 728 for (i = 0; i < num_queues; ++i) { 729 queue = &np->queues[i]; 730 napi_disable(&queue->napi); 731 } 732 return 0; 733 } 734 735 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 736 grant_ref_t ref) 737 { 738 int new = xennet_rxidx(queue->rx.req_prod_pvt); 739 740 BUG_ON(queue->rx_skbs[new]); 741 queue->rx_skbs[new] = skb; 742 queue->grant_rx_ref[new] = ref; 743 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 744 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 745 queue->rx.req_prod_pvt++; 746 } 747 748 static int xennet_get_extras(struct netfront_queue *queue, 749 struct xen_netif_extra_info *extras, 750 RING_IDX rp) 751 752 { 753 struct xen_netif_extra_info *extra; 754 struct device *dev = &queue->info->netdev->dev; 755 RING_IDX cons = queue->rx.rsp_cons; 756 int err = 0; 757 758 do { 759 struct sk_buff *skb; 760 grant_ref_t ref; 761 762 if (unlikely(cons + 1 == rp)) { 763 if (net_ratelimit()) 764 dev_warn(dev, "Missing extra info\n"); 765 err = -EBADR; 766 break; 767 } 768 769 extra = (struct xen_netif_extra_info *) 770 RING_GET_RESPONSE(&queue->rx, ++cons); 771 772 if (unlikely(!extra->type || 773 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 774 if (net_ratelimit()) 775 dev_warn(dev, "Invalid extra type: %d\n", 776 extra->type); 777 err = -EINVAL; 778 } else { 779 memcpy(&extras[extra->type - 1], extra, 780 sizeof(*extra)); 781 } 782 783 skb = xennet_get_rx_skb(queue, cons); 784 ref = xennet_get_rx_ref(queue, cons); 785 xennet_move_rx_slot(queue, skb, ref); 786 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 787 788 queue->rx.rsp_cons = cons; 789 return err; 790 } 791 792 static int xennet_get_responses(struct netfront_queue *queue, 793 struct netfront_rx_info *rinfo, RING_IDX rp, 794 struct sk_buff_head *list) 795 { 796 struct xen_netif_rx_response *rx = &rinfo->rx; 797 struct xen_netif_extra_info *extras = rinfo->extras; 798 struct device *dev = &queue->info->netdev->dev; 799 RING_IDX cons = queue->rx.rsp_cons; 800 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 801 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 802 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); 803 int slots = 1; 804 int err = 0; 805 unsigned long ret; 806 807 if (rx->flags & XEN_NETRXF_extra_info) { 808 err = xennet_get_extras(queue, extras, rp); 809 cons = queue->rx.rsp_cons; 810 } 811 812 for (;;) { 813 if (unlikely(rx->status < 0 || 814 rx->offset + rx->status > PAGE_SIZE)) { 815 if (net_ratelimit()) 816 dev_warn(dev, "rx->offset: %x, size: %u\n", 817 rx->offset, rx->status); 818 xennet_move_rx_slot(queue, skb, ref); 819 err = -EINVAL; 820 goto next; 821 } 822 823 /* 824 * This definitely indicates a bug, either in this driver or in 825 * the backend driver. In future this should flag the bad 826 * situation to the system controller to reboot the backend. 827 */ 828 if (ref == GRANT_INVALID_REF) { 829 if (net_ratelimit()) 830 dev_warn(dev, "Bad rx response id %d.\n", 831 rx->id); 832 err = -EINVAL; 833 goto next; 834 } 835 836 ret = gnttab_end_foreign_access_ref(ref, 0); 837 BUG_ON(!ret); 838 839 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 840 841 __skb_queue_tail(list, skb); 842 843 next: 844 if (!(rx->flags & XEN_NETRXF_more_data)) 845 break; 846 847 if (cons + slots == rp) { 848 if (net_ratelimit()) 849 dev_warn(dev, "Need more slots\n"); 850 err = -ENOENT; 851 break; 852 } 853 854 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 855 skb = xennet_get_rx_skb(queue, cons + slots); 856 ref = xennet_get_rx_ref(queue, cons + slots); 857 slots++; 858 } 859 860 if (unlikely(slots > max)) { 861 if (net_ratelimit()) 862 dev_warn(dev, "Too many slots\n"); 863 err = -E2BIG; 864 } 865 866 if (unlikely(err)) 867 queue->rx.rsp_cons = cons + slots; 868 869 return err; 870 } 871 872 static int xennet_set_skb_gso(struct sk_buff *skb, 873 struct xen_netif_extra_info *gso) 874 { 875 if (!gso->u.gso.size) { 876 if (net_ratelimit()) 877 pr_warn("GSO size must not be zero\n"); 878 return -EINVAL; 879 } 880 881 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 882 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 883 if (net_ratelimit()) 884 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 885 return -EINVAL; 886 } 887 888 skb_shinfo(skb)->gso_size = gso->u.gso.size; 889 skb_shinfo(skb)->gso_type = 890 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 891 SKB_GSO_TCPV4 : 892 SKB_GSO_TCPV6; 893 894 /* Header must be checked, and gso_segs computed. */ 895 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 896 skb_shinfo(skb)->gso_segs = 0; 897 898 return 0; 899 } 900 901 static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 902 struct sk_buff *skb, 903 struct sk_buff_head *list) 904 { 905 struct skb_shared_info *shinfo = skb_shinfo(skb); 906 RING_IDX cons = queue->rx.rsp_cons; 907 struct sk_buff *nskb; 908 909 while ((nskb = __skb_dequeue(list))) { 910 struct xen_netif_rx_response *rx = 911 RING_GET_RESPONSE(&queue->rx, ++cons); 912 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 913 914 if (shinfo->nr_frags == MAX_SKB_FRAGS) { 915 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 916 917 BUG_ON(pull_to <= skb_headlen(skb)); 918 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 919 } 920 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); 921 922 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), 923 rx->offset, rx->status, PAGE_SIZE); 924 925 skb_shinfo(nskb)->nr_frags = 0; 926 kfree_skb(nskb); 927 } 928 929 return cons; 930 } 931 932 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 933 { 934 bool recalculate_partial_csum = false; 935 936 /* 937 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 938 * peers can fail to set NETRXF_csum_blank when sending a GSO 939 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 940 * recalculate the partial checksum. 941 */ 942 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 943 struct netfront_info *np = netdev_priv(dev); 944 atomic_inc(&np->rx_gso_checksum_fixup); 945 skb->ip_summed = CHECKSUM_PARTIAL; 946 recalculate_partial_csum = true; 947 } 948 949 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 950 if (skb->ip_summed != CHECKSUM_PARTIAL) 951 return 0; 952 953 return skb_checksum_setup(skb, recalculate_partial_csum); 954 } 955 956 static int handle_incoming_queue(struct netfront_queue *queue, 957 struct sk_buff_head *rxq) 958 { 959 struct netfront_stats *stats = this_cpu_ptr(queue->info->stats); 960 int packets_dropped = 0; 961 struct sk_buff *skb; 962 963 while ((skb = __skb_dequeue(rxq)) != NULL) { 964 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 965 966 if (pull_to > skb_headlen(skb)) 967 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 968 969 /* Ethernet work: Delayed to here as it peeks the header. */ 970 skb->protocol = eth_type_trans(skb, queue->info->netdev); 971 skb_reset_network_header(skb); 972 973 if (checksum_setup(queue->info->netdev, skb)) { 974 kfree_skb(skb); 975 packets_dropped++; 976 queue->info->netdev->stats.rx_errors++; 977 continue; 978 } 979 980 u64_stats_update_begin(&stats->syncp); 981 stats->rx_packets++; 982 stats->rx_bytes += skb->len; 983 u64_stats_update_end(&stats->syncp); 984 985 /* Pass it up. */ 986 napi_gro_receive(&queue->napi, skb); 987 } 988 989 return packets_dropped; 990 } 991 992 static int xennet_poll(struct napi_struct *napi, int budget) 993 { 994 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 995 struct net_device *dev = queue->info->netdev; 996 struct sk_buff *skb; 997 struct netfront_rx_info rinfo; 998 struct xen_netif_rx_response *rx = &rinfo.rx; 999 struct xen_netif_extra_info *extras = rinfo.extras; 1000 RING_IDX i, rp; 1001 int work_done; 1002 struct sk_buff_head rxq; 1003 struct sk_buff_head errq; 1004 struct sk_buff_head tmpq; 1005 unsigned long flags; 1006 int err; 1007 1008 spin_lock(&queue->rx_lock); 1009 1010 skb_queue_head_init(&rxq); 1011 skb_queue_head_init(&errq); 1012 skb_queue_head_init(&tmpq); 1013 1014 rp = queue->rx.sring->rsp_prod; 1015 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1016 1017 i = queue->rx.rsp_cons; 1018 work_done = 0; 1019 while ((i != rp) && (work_done < budget)) { 1020 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 1021 memset(extras, 0, sizeof(rinfo.extras)); 1022 1023 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 1024 1025 if (unlikely(err)) { 1026 err: 1027 while ((skb = __skb_dequeue(&tmpq))) 1028 __skb_queue_tail(&errq, skb); 1029 dev->stats.rx_errors++; 1030 i = queue->rx.rsp_cons; 1031 continue; 1032 } 1033 1034 skb = __skb_dequeue(&tmpq); 1035 1036 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1037 struct xen_netif_extra_info *gso; 1038 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1039 1040 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1041 __skb_queue_head(&tmpq, skb); 1042 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1043 goto err; 1044 } 1045 } 1046 1047 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1048 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1049 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1050 1051 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1052 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1053 skb->data_len = rx->status; 1054 skb->len += rx->status; 1055 1056 i = xennet_fill_frags(queue, skb, &tmpq); 1057 1058 if (rx->flags & XEN_NETRXF_csum_blank) 1059 skb->ip_summed = CHECKSUM_PARTIAL; 1060 else if (rx->flags & XEN_NETRXF_data_validated) 1061 skb->ip_summed = CHECKSUM_UNNECESSARY; 1062 1063 __skb_queue_tail(&rxq, skb); 1064 1065 queue->rx.rsp_cons = ++i; 1066 work_done++; 1067 } 1068 1069 __skb_queue_purge(&errq); 1070 1071 work_done -= handle_incoming_queue(queue, &rxq); 1072 1073 /* If we get a callback with very few responses, reduce fill target. */ 1074 /* NB. Note exponential increase, linear decrease. */ 1075 if (((queue->rx.req_prod_pvt - queue->rx.sring->rsp_prod) > 1076 ((3*queue->rx_target) / 4)) && 1077 (--queue->rx_target < queue->rx_min_target)) 1078 queue->rx_target = queue->rx_min_target; 1079 1080 xennet_alloc_rx_buffers(queue); 1081 1082 if (work_done < budget) { 1083 int more_to_do = 0; 1084 1085 napi_gro_flush(napi, false); 1086 1087 local_irq_save(flags); 1088 1089 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1090 if (!more_to_do) 1091 __napi_complete(napi); 1092 1093 local_irq_restore(flags); 1094 } 1095 1096 spin_unlock(&queue->rx_lock); 1097 1098 return work_done; 1099 } 1100 1101 static int xennet_change_mtu(struct net_device *dev, int mtu) 1102 { 1103 int max = xennet_can_sg(dev) ? 1104 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; 1105 1106 if (mtu > max) 1107 return -EINVAL; 1108 dev->mtu = mtu; 1109 return 0; 1110 } 1111 1112 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, 1113 struct rtnl_link_stats64 *tot) 1114 { 1115 struct netfront_info *np = netdev_priv(dev); 1116 int cpu; 1117 1118 for_each_possible_cpu(cpu) { 1119 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu); 1120 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1121 unsigned int start; 1122 1123 do { 1124 start = u64_stats_fetch_begin_irq(&stats->syncp); 1125 1126 rx_packets = stats->rx_packets; 1127 tx_packets = stats->tx_packets; 1128 rx_bytes = stats->rx_bytes; 1129 tx_bytes = stats->tx_bytes; 1130 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 1131 1132 tot->rx_packets += rx_packets; 1133 tot->tx_packets += tx_packets; 1134 tot->rx_bytes += rx_bytes; 1135 tot->tx_bytes += tx_bytes; 1136 } 1137 1138 tot->rx_errors = dev->stats.rx_errors; 1139 tot->tx_dropped = dev->stats.tx_dropped; 1140 1141 return tot; 1142 } 1143 1144 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1145 { 1146 struct sk_buff *skb; 1147 int i; 1148 1149 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1150 /* Skip over entries which are actually freelist references */ 1151 if (skb_entry_is_link(&queue->tx_skbs[i])) 1152 continue; 1153 1154 skb = queue->tx_skbs[i].skb; 1155 get_page(queue->grant_tx_page[i]); 1156 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1157 GNTMAP_readonly, 1158 (unsigned long)page_address(queue->grant_tx_page[i])); 1159 queue->grant_tx_page[i] = NULL; 1160 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1161 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1162 dev_kfree_skb_irq(skb); 1163 } 1164 } 1165 1166 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1167 { 1168 int id, ref; 1169 1170 spin_lock_bh(&queue->rx_lock); 1171 1172 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1173 struct sk_buff *skb; 1174 struct page *page; 1175 1176 skb = queue->rx_skbs[id]; 1177 if (!skb) 1178 continue; 1179 1180 ref = queue->grant_rx_ref[id]; 1181 if (ref == GRANT_INVALID_REF) 1182 continue; 1183 1184 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1185 1186 /* gnttab_end_foreign_access() needs a page ref until 1187 * foreign access is ended (which may be deferred). 1188 */ 1189 get_page(page); 1190 gnttab_end_foreign_access(ref, 0, 1191 (unsigned long)page_address(page)); 1192 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1193 1194 kfree_skb(skb); 1195 } 1196 1197 spin_unlock_bh(&queue->rx_lock); 1198 } 1199 1200 static netdev_features_t xennet_fix_features(struct net_device *dev, 1201 netdev_features_t features) 1202 { 1203 struct netfront_info *np = netdev_priv(dev); 1204 int val; 1205 1206 if (features & NETIF_F_SG) { 1207 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", 1208 "%d", &val) < 0) 1209 val = 0; 1210 1211 if (!val) 1212 features &= ~NETIF_F_SG; 1213 } 1214 1215 if (features & NETIF_F_IPV6_CSUM) { 1216 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1217 "feature-ipv6-csum-offload", "%d", &val) < 0) 1218 val = 0; 1219 1220 if (!val) 1221 features &= ~NETIF_F_IPV6_CSUM; 1222 } 1223 1224 if (features & NETIF_F_TSO) { 1225 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1226 "feature-gso-tcpv4", "%d", &val) < 0) 1227 val = 0; 1228 1229 if (!val) 1230 features &= ~NETIF_F_TSO; 1231 } 1232 1233 if (features & NETIF_F_TSO6) { 1234 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, 1235 "feature-gso-tcpv6", "%d", &val) < 0) 1236 val = 0; 1237 1238 if (!val) 1239 features &= ~NETIF_F_TSO6; 1240 } 1241 1242 return features; 1243 } 1244 1245 static int xennet_set_features(struct net_device *dev, 1246 netdev_features_t features) 1247 { 1248 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1249 netdev_info(dev, "Reducing MTU because no SG offload"); 1250 dev->mtu = ETH_DATA_LEN; 1251 } 1252 1253 return 0; 1254 } 1255 1256 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1257 { 1258 struct netfront_queue *queue = dev_id; 1259 unsigned long flags; 1260 1261 spin_lock_irqsave(&queue->tx_lock, flags); 1262 xennet_tx_buf_gc(queue); 1263 spin_unlock_irqrestore(&queue->tx_lock, flags); 1264 1265 return IRQ_HANDLED; 1266 } 1267 1268 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1269 { 1270 struct netfront_queue *queue = dev_id; 1271 struct net_device *dev = queue->info->netdev; 1272 1273 if (likely(netif_carrier_ok(dev) && 1274 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1275 napi_schedule(&queue->napi); 1276 1277 return IRQ_HANDLED; 1278 } 1279 1280 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1281 { 1282 xennet_tx_interrupt(irq, dev_id); 1283 xennet_rx_interrupt(irq, dev_id); 1284 return IRQ_HANDLED; 1285 } 1286 1287 #ifdef CONFIG_NET_POLL_CONTROLLER 1288 static void xennet_poll_controller(struct net_device *dev) 1289 { 1290 /* Poll each queue */ 1291 struct netfront_info *info = netdev_priv(dev); 1292 unsigned int num_queues = dev->real_num_tx_queues; 1293 unsigned int i; 1294 for (i = 0; i < num_queues; ++i) 1295 xennet_interrupt(0, &info->queues[i]); 1296 } 1297 #endif 1298 1299 static const struct net_device_ops xennet_netdev_ops = { 1300 .ndo_open = xennet_open, 1301 .ndo_stop = xennet_close, 1302 .ndo_start_xmit = xennet_start_xmit, 1303 .ndo_change_mtu = xennet_change_mtu, 1304 .ndo_get_stats64 = xennet_get_stats64, 1305 .ndo_set_mac_address = eth_mac_addr, 1306 .ndo_validate_addr = eth_validate_addr, 1307 .ndo_fix_features = xennet_fix_features, 1308 .ndo_set_features = xennet_set_features, 1309 .ndo_select_queue = xennet_select_queue, 1310 #ifdef CONFIG_NET_POLL_CONTROLLER 1311 .ndo_poll_controller = xennet_poll_controller, 1312 #endif 1313 }; 1314 1315 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1316 { 1317 int err; 1318 struct net_device *netdev; 1319 struct netfront_info *np; 1320 1321 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1322 if (!netdev) 1323 return ERR_PTR(-ENOMEM); 1324 1325 np = netdev_priv(netdev); 1326 np->xbdev = dev; 1327 1328 /* No need to use rtnl_lock() before the call below as it 1329 * happens before register_netdev(). 1330 */ 1331 netif_set_real_num_tx_queues(netdev, 0); 1332 np->queues = NULL; 1333 1334 err = -ENOMEM; 1335 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1336 if (np->stats == NULL) 1337 goto exit; 1338 1339 netdev->netdev_ops = &xennet_netdev_ops; 1340 1341 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1342 NETIF_F_GSO_ROBUST; 1343 netdev->hw_features = NETIF_F_SG | 1344 NETIF_F_IPV6_CSUM | 1345 NETIF_F_TSO | NETIF_F_TSO6; 1346 1347 /* 1348 * Assume that all hw features are available for now. This set 1349 * will be adjusted by the call to netdev_update_features() in 1350 * xennet_connect() which is the earliest point where we can 1351 * negotiate with the backend regarding supported features. 1352 */ 1353 netdev->features |= netdev->hw_features; 1354 1355 netdev->ethtool_ops = &xennet_ethtool_ops; 1356 SET_NETDEV_DEV(netdev, &dev->dev); 1357 1358 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); 1359 1360 np->netdev = netdev; 1361 1362 netif_carrier_off(netdev); 1363 1364 return netdev; 1365 1366 exit: 1367 free_netdev(netdev); 1368 return ERR_PTR(err); 1369 } 1370 1371 /** 1372 * Entry point to this code when a new device is created. Allocate the basic 1373 * structures and the ring buffers for communication with the backend, and 1374 * inform the backend of the appropriate details for those. 1375 */ 1376 static int netfront_probe(struct xenbus_device *dev, 1377 const struct xenbus_device_id *id) 1378 { 1379 int err; 1380 struct net_device *netdev; 1381 struct netfront_info *info; 1382 1383 netdev = xennet_create_dev(dev); 1384 if (IS_ERR(netdev)) { 1385 err = PTR_ERR(netdev); 1386 xenbus_dev_fatal(dev, err, "creating netdev"); 1387 return err; 1388 } 1389 1390 info = netdev_priv(netdev); 1391 dev_set_drvdata(&dev->dev, info); 1392 1393 err = register_netdev(info->netdev); 1394 if (err) { 1395 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1396 goto fail; 1397 } 1398 1399 err = xennet_sysfs_addif(info->netdev); 1400 if (err) { 1401 unregister_netdev(info->netdev); 1402 pr_warn("%s: add sysfs failed err=%d\n", __func__, err); 1403 goto fail; 1404 } 1405 1406 return 0; 1407 1408 fail: 1409 free_netdev(netdev); 1410 dev_set_drvdata(&dev->dev, NULL); 1411 return err; 1412 } 1413 1414 static void xennet_end_access(int ref, void *page) 1415 { 1416 /* This frees the page as a side-effect */ 1417 if (ref != GRANT_INVALID_REF) 1418 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1419 } 1420 1421 static void xennet_disconnect_backend(struct netfront_info *info) 1422 { 1423 unsigned int i = 0; 1424 unsigned int num_queues = info->netdev->real_num_tx_queues; 1425 1426 netif_carrier_off(info->netdev); 1427 1428 for (i = 0; i < num_queues; ++i) { 1429 struct netfront_queue *queue = &info->queues[i]; 1430 1431 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1432 unbind_from_irqhandler(queue->tx_irq, queue); 1433 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1434 unbind_from_irqhandler(queue->tx_irq, queue); 1435 unbind_from_irqhandler(queue->rx_irq, queue); 1436 } 1437 queue->tx_evtchn = queue->rx_evtchn = 0; 1438 queue->tx_irq = queue->rx_irq = 0; 1439 1440 napi_synchronize(&queue->napi); 1441 1442 xennet_release_tx_bufs(queue); 1443 xennet_release_rx_bufs(queue); 1444 gnttab_free_grant_references(queue->gref_tx_head); 1445 gnttab_free_grant_references(queue->gref_rx_head); 1446 1447 /* End access and free the pages */ 1448 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1449 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1450 1451 queue->tx_ring_ref = GRANT_INVALID_REF; 1452 queue->rx_ring_ref = GRANT_INVALID_REF; 1453 queue->tx.sring = NULL; 1454 queue->rx.sring = NULL; 1455 } 1456 } 1457 1458 /** 1459 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1460 * driver restart. We tear down our netif structure and recreate it, but 1461 * leave the device-layer structures intact so that this is transparent to the 1462 * rest of the kernel. 1463 */ 1464 static int netfront_resume(struct xenbus_device *dev) 1465 { 1466 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1467 1468 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1469 1470 xennet_disconnect_backend(info); 1471 return 0; 1472 } 1473 1474 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1475 { 1476 char *s, *e, *macstr; 1477 int i; 1478 1479 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1480 if (IS_ERR(macstr)) 1481 return PTR_ERR(macstr); 1482 1483 for (i = 0; i < ETH_ALEN; i++) { 1484 mac[i] = simple_strtoul(s, &e, 16); 1485 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1486 kfree(macstr); 1487 return -ENOENT; 1488 } 1489 s = e+1; 1490 } 1491 1492 kfree(macstr); 1493 return 0; 1494 } 1495 1496 static int setup_netfront_single(struct netfront_queue *queue) 1497 { 1498 int err; 1499 1500 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1501 if (err < 0) 1502 goto fail; 1503 1504 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1505 xennet_interrupt, 1506 0, queue->info->netdev->name, queue); 1507 if (err < 0) 1508 goto bind_fail; 1509 queue->rx_evtchn = queue->tx_evtchn; 1510 queue->rx_irq = queue->tx_irq = err; 1511 1512 return 0; 1513 1514 bind_fail: 1515 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1516 queue->tx_evtchn = 0; 1517 fail: 1518 return err; 1519 } 1520 1521 static int setup_netfront_split(struct netfront_queue *queue) 1522 { 1523 int err; 1524 1525 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1526 if (err < 0) 1527 goto fail; 1528 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1529 if (err < 0) 1530 goto alloc_rx_evtchn_fail; 1531 1532 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1533 "%s-tx", queue->name); 1534 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1535 xennet_tx_interrupt, 1536 0, queue->tx_irq_name, queue); 1537 if (err < 0) 1538 goto bind_tx_fail; 1539 queue->tx_irq = err; 1540 1541 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1542 "%s-rx", queue->name); 1543 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1544 xennet_rx_interrupt, 1545 0, queue->rx_irq_name, queue); 1546 if (err < 0) 1547 goto bind_rx_fail; 1548 queue->rx_irq = err; 1549 1550 return 0; 1551 1552 bind_rx_fail: 1553 unbind_from_irqhandler(queue->tx_irq, queue); 1554 queue->tx_irq = 0; 1555 bind_tx_fail: 1556 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1557 queue->rx_evtchn = 0; 1558 alloc_rx_evtchn_fail: 1559 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1560 queue->tx_evtchn = 0; 1561 fail: 1562 return err; 1563 } 1564 1565 static int setup_netfront(struct xenbus_device *dev, 1566 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1567 { 1568 struct xen_netif_tx_sring *txs; 1569 struct xen_netif_rx_sring *rxs; 1570 int err; 1571 1572 queue->tx_ring_ref = GRANT_INVALID_REF; 1573 queue->rx_ring_ref = GRANT_INVALID_REF; 1574 queue->rx.sring = NULL; 1575 queue->tx.sring = NULL; 1576 1577 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1578 if (!txs) { 1579 err = -ENOMEM; 1580 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1581 goto fail; 1582 } 1583 SHARED_RING_INIT(txs); 1584 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE); 1585 1586 err = xenbus_grant_ring(dev, virt_to_mfn(txs)); 1587 if (err < 0) 1588 goto grant_tx_ring_fail; 1589 queue->tx_ring_ref = err; 1590 1591 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1592 if (!rxs) { 1593 err = -ENOMEM; 1594 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1595 goto alloc_rx_ring_fail; 1596 } 1597 SHARED_RING_INIT(rxs); 1598 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE); 1599 1600 err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); 1601 if (err < 0) 1602 goto grant_rx_ring_fail; 1603 queue->rx_ring_ref = err; 1604 1605 if (feature_split_evtchn) 1606 err = setup_netfront_split(queue); 1607 /* setup single event channel if 1608 * a) feature-split-event-channels == 0 1609 * b) feature-split-event-channels == 1 but failed to setup 1610 */ 1611 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1612 err = setup_netfront_single(queue); 1613 1614 if (err) 1615 goto alloc_evtchn_fail; 1616 1617 return 0; 1618 1619 /* If we fail to setup netfront, it is safe to just revoke access to 1620 * granted pages because backend is not accessing it at this point. 1621 */ 1622 alloc_evtchn_fail: 1623 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1624 grant_rx_ring_fail: 1625 free_page((unsigned long)rxs); 1626 alloc_rx_ring_fail: 1627 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1628 grant_tx_ring_fail: 1629 free_page((unsigned long)txs); 1630 fail: 1631 return err; 1632 } 1633 1634 /* Queue-specific initialisation 1635 * This used to be done in xennet_create_dev() but must now 1636 * be run per-queue. 1637 */ 1638 static int xennet_init_queue(struct netfront_queue *queue) 1639 { 1640 unsigned short i; 1641 int err = 0; 1642 1643 spin_lock_init(&queue->tx_lock); 1644 spin_lock_init(&queue->rx_lock); 1645 1646 skb_queue_head_init(&queue->rx_batch); 1647 queue->rx_target = RX_DFL_MIN_TARGET; 1648 queue->rx_min_target = RX_DFL_MIN_TARGET; 1649 queue->rx_max_target = RX_MAX_TARGET; 1650 1651 init_timer(&queue->rx_refill_timer); 1652 queue->rx_refill_timer.data = (unsigned long)queue; 1653 queue->rx_refill_timer.function = rx_refill_timeout; 1654 1655 snprintf(queue->name, sizeof(queue->name), "%s-q%u", 1656 queue->info->netdev->name, queue->id); 1657 1658 /* Initialise tx_skbs as a free chain containing every entry. */ 1659 queue->tx_skb_freelist = 0; 1660 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1661 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1662 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1663 queue->grant_tx_page[i] = NULL; 1664 } 1665 1666 /* Clear out rx_skbs */ 1667 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1668 queue->rx_skbs[i] = NULL; 1669 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1670 } 1671 1672 /* A grant for every tx ring slot */ 1673 if (gnttab_alloc_grant_references(TX_MAX_TARGET, 1674 &queue->gref_tx_head) < 0) { 1675 pr_alert("can't alloc tx grant refs\n"); 1676 err = -ENOMEM; 1677 goto exit; 1678 } 1679 1680 /* A grant for every rx ring slot */ 1681 if (gnttab_alloc_grant_references(RX_MAX_TARGET, 1682 &queue->gref_rx_head) < 0) { 1683 pr_alert("can't alloc rx grant refs\n"); 1684 err = -ENOMEM; 1685 goto exit_free_tx; 1686 } 1687 1688 return 0; 1689 1690 exit_free_tx: 1691 gnttab_free_grant_references(queue->gref_tx_head); 1692 exit: 1693 return err; 1694 } 1695 1696 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1697 struct xenbus_transaction *xbt, int write_hierarchical) 1698 { 1699 /* Write the queue-specific keys into XenStore in the traditional 1700 * way for a single queue, or in a queue subkeys for multiple 1701 * queues. 1702 */ 1703 struct xenbus_device *dev = queue->info->xbdev; 1704 int err; 1705 const char *message; 1706 char *path; 1707 size_t pathsize; 1708 1709 /* Choose the correct place to write the keys */ 1710 if (write_hierarchical) { 1711 pathsize = strlen(dev->nodename) + 10; 1712 path = kzalloc(pathsize, GFP_KERNEL); 1713 if (!path) { 1714 err = -ENOMEM; 1715 message = "out of memory while writing ring references"; 1716 goto error; 1717 } 1718 snprintf(path, pathsize, "%s/queue-%u", 1719 dev->nodename, queue->id); 1720 } else { 1721 path = (char *)dev->nodename; 1722 } 1723 1724 /* Write ring references */ 1725 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1726 queue->tx_ring_ref); 1727 if (err) { 1728 message = "writing tx-ring-ref"; 1729 goto error; 1730 } 1731 1732 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1733 queue->rx_ring_ref); 1734 if (err) { 1735 message = "writing rx-ring-ref"; 1736 goto error; 1737 } 1738 1739 /* Write event channels; taking into account both shared 1740 * and split event channel scenarios. 1741 */ 1742 if (queue->tx_evtchn == queue->rx_evtchn) { 1743 /* Shared event channel */ 1744 err = xenbus_printf(*xbt, path, 1745 "event-channel", "%u", queue->tx_evtchn); 1746 if (err) { 1747 message = "writing event-channel"; 1748 goto error; 1749 } 1750 } else { 1751 /* Split event channels */ 1752 err = xenbus_printf(*xbt, path, 1753 "event-channel-tx", "%u", queue->tx_evtchn); 1754 if (err) { 1755 message = "writing event-channel-tx"; 1756 goto error; 1757 } 1758 1759 err = xenbus_printf(*xbt, path, 1760 "event-channel-rx", "%u", queue->rx_evtchn); 1761 if (err) { 1762 message = "writing event-channel-rx"; 1763 goto error; 1764 } 1765 } 1766 1767 if (write_hierarchical) 1768 kfree(path); 1769 return 0; 1770 1771 error: 1772 if (write_hierarchical) 1773 kfree(path); 1774 xenbus_dev_fatal(dev, err, "%s", message); 1775 return err; 1776 } 1777 1778 static void xennet_destroy_queues(struct netfront_info *info) 1779 { 1780 unsigned int i; 1781 1782 rtnl_lock(); 1783 1784 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1785 struct netfront_queue *queue = &info->queues[i]; 1786 1787 if (netif_running(info->netdev)) 1788 napi_disable(&queue->napi); 1789 netif_napi_del(&queue->napi); 1790 } 1791 1792 rtnl_unlock(); 1793 1794 kfree(info->queues); 1795 info->queues = NULL; 1796 } 1797 1798 static int xennet_create_queues(struct netfront_info *info, 1799 unsigned int num_queues) 1800 { 1801 unsigned int i; 1802 int ret; 1803 1804 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue), 1805 GFP_KERNEL); 1806 if (!info->queues) 1807 return -ENOMEM; 1808 1809 rtnl_lock(); 1810 1811 for (i = 0; i < num_queues; i++) { 1812 struct netfront_queue *queue = &info->queues[i]; 1813 1814 queue->id = i; 1815 queue->info = info; 1816 1817 ret = xennet_init_queue(queue); 1818 if (ret < 0) { 1819 dev_warn(&info->netdev->dev, 1820 "only created %d queues\n", i); 1821 num_queues = i; 1822 break; 1823 } 1824 1825 netif_napi_add(queue->info->netdev, &queue->napi, 1826 xennet_poll, 64); 1827 if (netif_running(info->netdev)) 1828 napi_enable(&queue->napi); 1829 } 1830 1831 netif_set_real_num_tx_queues(info->netdev, num_queues); 1832 1833 rtnl_unlock(); 1834 1835 if (num_queues == 0) { 1836 dev_err(&info->netdev->dev, "no queues\n"); 1837 return -EINVAL; 1838 } 1839 return 0; 1840 } 1841 1842 /* Common code used when first setting up, and when resuming. */ 1843 static int talk_to_netback(struct xenbus_device *dev, 1844 struct netfront_info *info) 1845 { 1846 const char *message; 1847 struct xenbus_transaction xbt; 1848 int err; 1849 unsigned int feature_split_evtchn; 1850 unsigned int i = 0; 1851 unsigned int max_queues = 0; 1852 struct netfront_queue *queue = NULL; 1853 unsigned int num_queues = 1; 1854 1855 info->netdev->irq = 0; 1856 1857 /* Check if backend supports multiple queues */ 1858 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1859 "multi-queue-max-queues", "%u", &max_queues); 1860 if (err < 0) 1861 max_queues = 1; 1862 num_queues = min(max_queues, xennet_max_queues); 1863 1864 /* Check feature-split-event-channels */ 1865 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, 1866 "feature-split-event-channels", "%u", 1867 &feature_split_evtchn); 1868 if (err < 0) 1869 feature_split_evtchn = 0; 1870 1871 /* Read mac addr. */ 1872 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1873 if (err) { 1874 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1875 goto out; 1876 } 1877 1878 if (info->queues) 1879 xennet_destroy_queues(info); 1880 1881 err = xennet_create_queues(info, num_queues); 1882 if (err < 0) 1883 goto destroy_ring; 1884 1885 /* Create shared ring, alloc event channel -- for each queue */ 1886 for (i = 0; i < num_queues; ++i) { 1887 queue = &info->queues[i]; 1888 err = setup_netfront(dev, queue, feature_split_evtchn); 1889 if (err) { 1890 /* setup_netfront() will tidy up the current 1891 * queue on error, but we need to clean up 1892 * those already allocated. 1893 */ 1894 if (i > 0) { 1895 rtnl_lock(); 1896 netif_set_real_num_tx_queues(info->netdev, i); 1897 rtnl_unlock(); 1898 goto destroy_ring; 1899 } else { 1900 goto out; 1901 } 1902 } 1903 } 1904 1905 again: 1906 err = xenbus_transaction_start(&xbt); 1907 if (err) { 1908 xenbus_dev_fatal(dev, err, "starting transaction"); 1909 goto destroy_ring; 1910 } 1911 1912 if (num_queues == 1) { 1913 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1914 if (err) 1915 goto abort_transaction_no_dev_fatal; 1916 } else { 1917 /* Write the number of queues */ 1918 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", 1919 "%u", num_queues); 1920 if (err) { 1921 message = "writing multi-queue-num-queues"; 1922 goto abort_transaction_no_dev_fatal; 1923 } 1924 1925 /* Write the keys for each queue */ 1926 for (i = 0; i < num_queues; ++i) { 1927 queue = &info->queues[i]; 1928 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1929 if (err) 1930 goto abort_transaction_no_dev_fatal; 1931 } 1932 } 1933 1934 /* The remaining keys are not queue-specific */ 1935 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1936 1); 1937 if (err) { 1938 message = "writing request-rx-copy"; 1939 goto abort_transaction; 1940 } 1941 1942 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1943 if (err) { 1944 message = "writing feature-rx-notify"; 1945 goto abort_transaction; 1946 } 1947 1948 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1949 if (err) { 1950 message = "writing feature-sg"; 1951 goto abort_transaction; 1952 } 1953 1954 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1955 if (err) { 1956 message = "writing feature-gso-tcpv4"; 1957 goto abort_transaction; 1958 } 1959 1960 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1961 if (err) { 1962 message = "writing feature-gso-tcpv6"; 1963 goto abort_transaction; 1964 } 1965 1966 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1967 "1"); 1968 if (err) { 1969 message = "writing feature-ipv6-csum-offload"; 1970 goto abort_transaction; 1971 } 1972 1973 err = xenbus_transaction_end(xbt, 0); 1974 if (err) { 1975 if (err == -EAGAIN) 1976 goto again; 1977 xenbus_dev_fatal(dev, err, "completing transaction"); 1978 goto destroy_ring; 1979 } 1980 1981 return 0; 1982 1983 abort_transaction: 1984 xenbus_dev_fatal(dev, err, "%s", message); 1985 abort_transaction_no_dev_fatal: 1986 xenbus_transaction_end(xbt, 1); 1987 destroy_ring: 1988 xennet_disconnect_backend(info); 1989 kfree(info->queues); 1990 info->queues = NULL; 1991 rtnl_lock(); 1992 netif_set_real_num_tx_queues(info->netdev, 0); 1993 rtnl_unlock(); 1994 out: 1995 return err; 1996 } 1997 1998 static int xennet_connect(struct net_device *dev) 1999 { 2000 struct netfront_info *np = netdev_priv(dev); 2001 unsigned int num_queues = 0; 2002 int err; 2003 unsigned int feature_rx_copy; 2004 unsigned int j = 0; 2005 struct netfront_queue *queue = NULL; 2006 2007 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, 2008 "feature-rx-copy", "%u", &feature_rx_copy); 2009 if (err != 1) 2010 feature_rx_copy = 0; 2011 2012 if (!feature_rx_copy) { 2013 dev_info(&dev->dev, 2014 "backend does not support copying receive path\n"); 2015 return -ENODEV; 2016 } 2017 2018 err = talk_to_netback(np->xbdev, np); 2019 if (err) 2020 return err; 2021 2022 /* talk_to_netback() sets the correct number of queues */ 2023 num_queues = dev->real_num_tx_queues; 2024 2025 rtnl_lock(); 2026 netdev_update_features(dev); 2027 rtnl_unlock(); 2028 2029 /* 2030 * All public and private state should now be sane. Get 2031 * ready to start sending and receiving packets and give the driver 2032 * domain a kick because we've probably just requeued some 2033 * packets. 2034 */ 2035 netif_carrier_on(np->netdev); 2036 for (j = 0; j < num_queues; ++j) { 2037 queue = &np->queues[j]; 2038 2039 notify_remote_via_irq(queue->tx_irq); 2040 if (queue->tx_irq != queue->rx_irq) 2041 notify_remote_via_irq(queue->rx_irq); 2042 2043 spin_lock_irq(&queue->tx_lock); 2044 xennet_tx_buf_gc(queue); 2045 spin_unlock_irq(&queue->tx_lock); 2046 2047 spin_lock_bh(&queue->rx_lock); 2048 xennet_alloc_rx_buffers(queue); 2049 spin_unlock_bh(&queue->rx_lock); 2050 } 2051 2052 return 0; 2053 } 2054 2055 /** 2056 * Callback received when the backend's state changes. 2057 */ 2058 static void netback_changed(struct xenbus_device *dev, 2059 enum xenbus_state backend_state) 2060 { 2061 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2062 struct net_device *netdev = np->netdev; 2063 2064 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2065 2066 switch (backend_state) { 2067 case XenbusStateInitialising: 2068 case XenbusStateInitialised: 2069 case XenbusStateReconfiguring: 2070 case XenbusStateReconfigured: 2071 case XenbusStateUnknown: 2072 break; 2073 2074 case XenbusStateInitWait: 2075 if (dev->state != XenbusStateInitialising) 2076 break; 2077 if (xennet_connect(netdev) != 0) 2078 break; 2079 xenbus_switch_state(dev, XenbusStateConnected); 2080 break; 2081 2082 case XenbusStateConnected: 2083 netdev_notify_peers(netdev); 2084 break; 2085 2086 case XenbusStateClosed: 2087 if (dev->state == XenbusStateClosed) 2088 break; 2089 /* Missed the backend's CLOSING state -- fallthrough */ 2090 case XenbusStateClosing: 2091 xenbus_frontend_closed(dev); 2092 break; 2093 } 2094 } 2095 2096 static const struct xennet_stat { 2097 char name[ETH_GSTRING_LEN]; 2098 u16 offset; 2099 } xennet_stats[] = { 2100 { 2101 "rx_gso_checksum_fixup", 2102 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2103 }, 2104 }; 2105 2106 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2107 { 2108 switch (string_set) { 2109 case ETH_SS_STATS: 2110 return ARRAY_SIZE(xennet_stats); 2111 default: 2112 return -EINVAL; 2113 } 2114 } 2115 2116 static void xennet_get_ethtool_stats(struct net_device *dev, 2117 struct ethtool_stats *stats, u64 * data) 2118 { 2119 void *np = netdev_priv(dev); 2120 int i; 2121 2122 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2123 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2124 } 2125 2126 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2127 { 2128 int i; 2129 2130 switch (stringset) { 2131 case ETH_SS_STATS: 2132 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2133 memcpy(data + i * ETH_GSTRING_LEN, 2134 xennet_stats[i].name, ETH_GSTRING_LEN); 2135 break; 2136 } 2137 } 2138 2139 static const struct ethtool_ops xennet_ethtool_ops = 2140 { 2141 .get_link = ethtool_op_get_link, 2142 2143 .get_sset_count = xennet_get_sset_count, 2144 .get_ethtool_stats = xennet_get_ethtool_stats, 2145 .get_strings = xennet_get_strings, 2146 }; 2147 2148 #ifdef CONFIG_SYSFS 2149 static ssize_t show_rxbuf_min(struct device *dev, 2150 struct device_attribute *attr, char *buf) 2151 { 2152 struct net_device *netdev = to_net_dev(dev); 2153 struct netfront_info *info = netdev_priv(netdev); 2154 unsigned int num_queues = netdev->real_num_tx_queues; 2155 2156 if (num_queues) 2157 return sprintf(buf, "%u\n", info->queues[0].rx_min_target); 2158 else 2159 return sprintf(buf, "%u\n", RX_MIN_TARGET); 2160 } 2161 2162 static ssize_t store_rxbuf_min(struct device *dev, 2163 struct device_attribute *attr, 2164 const char *buf, size_t len) 2165 { 2166 struct net_device *netdev = to_net_dev(dev); 2167 struct netfront_info *np = netdev_priv(netdev); 2168 unsigned int num_queues = netdev->real_num_tx_queues; 2169 char *endp; 2170 unsigned long target; 2171 unsigned int i; 2172 struct netfront_queue *queue; 2173 2174 if (!capable(CAP_NET_ADMIN)) 2175 return -EPERM; 2176 2177 target = simple_strtoul(buf, &endp, 0); 2178 if (endp == buf) 2179 return -EBADMSG; 2180 2181 if (target < RX_MIN_TARGET) 2182 target = RX_MIN_TARGET; 2183 if (target > RX_MAX_TARGET) 2184 target = RX_MAX_TARGET; 2185 2186 for (i = 0; i < num_queues; ++i) { 2187 queue = &np->queues[i]; 2188 spin_lock_bh(&queue->rx_lock); 2189 if (target > queue->rx_max_target) 2190 queue->rx_max_target = target; 2191 queue->rx_min_target = target; 2192 if (target > queue->rx_target) 2193 queue->rx_target = target; 2194 2195 xennet_alloc_rx_buffers(queue); 2196 2197 spin_unlock_bh(&queue->rx_lock); 2198 } 2199 return len; 2200 } 2201 2202 static ssize_t show_rxbuf_max(struct device *dev, 2203 struct device_attribute *attr, char *buf) 2204 { 2205 struct net_device *netdev = to_net_dev(dev); 2206 struct netfront_info *info = netdev_priv(netdev); 2207 unsigned int num_queues = netdev->real_num_tx_queues; 2208 2209 if (num_queues) 2210 return sprintf(buf, "%u\n", info->queues[0].rx_max_target); 2211 else 2212 return sprintf(buf, "%u\n", RX_MAX_TARGET); 2213 } 2214 2215 static ssize_t store_rxbuf_max(struct device *dev, 2216 struct device_attribute *attr, 2217 const char *buf, size_t len) 2218 { 2219 struct net_device *netdev = to_net_dev(dev); 2220 struct netfront_info *np = netdev_priv(netdev); 2221 unsigned int num_queues = netdev->real_num_tx_queues; 2222 char *endp; 2223 unsigned long target; 2224 unsigned int i = 0; 2225 struct netfront_queue *queue = NULL; 2226 2227 if (!capable(CAP_NET_ADMIN)) 2228 return -EPERM; 2229 2230 target = simple_strtoul(buf, &endp, 0); 2231 if (endp == buf) 2232 return -EBADMSG; 2233 2234 if (target < RX_MIN_TARGET) 2235 target = RX_MIN_TARGET; 2236 if (target > RX_MAX_TARGET) 2237 target = RX_MAX_TARGET; 2238 2239 for (i = 0; i < num_queues; ++i) { 2240 queue = &np->queues[i]; 2241 spin_lock_bh(&queue->rx_lock); 2242 if (target < queue->rx_min_target) 2243 queue->rx_min_target = target; 2244 queue->rx_max_target = target; 2245 if (target < queue->rx_target) 2246 queue->rx_target = target; 2247 2248 xennet_alloc_rx_buffers(queue); 2249 2250 spin_unlock_bh(&queue->rx_lock); 2251 } 2252 return len; 2253 } 2254 2255 static ssize_t show_rxbuf_cur(struct device *dev, 2256 struct device_attribute *attr, char *buf) 2257 { 2258 struct net_device *netdev = to_net_dev(dev); 2259 struct netfront_info *info = netdev_priv(netdev); 2260 unsigned int num_queues = netdev->real_num_tx_queues; 2261 2262 if (num_queues) 2263 return sprintf(buf, "%u\n", info->queues[0].rx_target); 2264 else 2265 return sprintf(buf, "0\n"); 2266 } 2267 2268 static struct device_attribute xennet_attrs[] = { 2269 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), 2270 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), 2271 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), 2272 }; 2273 2274 static int xennet_sysfs_addif(struct net_device *netdev) 2275 { 2276 int i; 2277 int err; 2278 2279 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { 2280 err = device_create_file(&netdev->dev, 2281 &xennet_attrs[i]); 2282 if (err) 2283 goto fail; 2284 } 2285 return 0; 2286 2287 fail: 2288 while (--i >= 0) 2289 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2290 return err; 2291 } 2292 2293 static void xennet_sysfs_delif(struct net_device *netdev) 2294 { 2295 int i; 2296 2297 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) 2298 device_remove_file(&netdev->dev, &xennet_attrs[i]); 2299 } 2300 2301 #endif /* CONFIG_SYSFS */ 2302 2303 static int xennet_remove(struct xenbus_device *dev) 2304 { 2305 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2306 unsigned int num_queues = info->netdev->real_num_tx_queues; 2307 struct netfront_queue *queue = NULL; 2308 unsigned int i = 0; 2309 2310 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2311 2312 xennet_disconnect_backend(info); 2313 2314 xennet_sysfs_delif(info->netdev); 2315 2316 unregister_netdev(info->netdev); 2317 2318 for (i = 0; i < num_queues; ++i) { 2319 queue = &info->queues[i]; 2320 del_timer_sync(&queue->rx_refill_timer); 2321 } 2322 2323 if (num_queues) { 2324 kfree(info->queues); 2325 info->queues = NULL; 2326 } 2327 2328 free_percpu(info->stats); 2329 2330 free_netdev(info->netdev); 2331 2332 return 0; 2333 } 2334 2335 static const struct xenbus_device_id netfront_ids[] = { 2336 { "vif" }, 2337 { "" } 2338 }; 2339 2340 static struct xenbus_driver netfront_driver = { 2341 .ids = netfront_ids, 2342 .probe = netfront_probe, 2343 .remove = xennet_remove, 2344 .resume = netfront_resume, 2345 .otherend_changed = netback_changed, 2346 }; 2347 2348 static int __init netif_init(void) 2349 { 2350 if (!xen_domain()) 2351 return -ENODEV; 2352 2353 if (!xen_has_pv_nic_devices()) 2354 return -ENODEV; 2355 2356 pr_info("Initialising Xen virtual ethernet driver\n"); 2357 2358 /* Allow as many queues as there are CPUs, by default */ 2359 xennet_max_queues = num_online_cpus(); 2360 2361 return xenbus_register_frontend(&netfront_driver); 2362 } 2363 module_init(netif_init); 2364 2365 2366 static void __exit netif_exit(void) 2367 { 2368 xenbus_unregister_driver(&netfront_driver); 2369 } 2370 module_exit(netif_exit); 2371 2372 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2373 MODULE_LICENSE("GPL"); 2374 MODULE_ALIAS("xen:vif"); 2375 MODULE_ALIAS("xennet"); 2376