drivers/net/xen-netback/interface.c

   1 /*
   2  * Network-device interface management.
   3  *
   4  * Copyright (c) 2004-2005, Keir Fraser
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation; or, when distributed
   9  * separately from the Linux kernel or incorporated into other
  10  * software packages, subject to the following license:
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this source file (the "Software"), to deal in the Software without
  14  * restriction, including without limitation the rights to use, copy, modify,
  15  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  16  * and to permit persons to whom the Software is furnished to do so, subject to
  17  * the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  28  * IN THE SOFTWARE.
  29  */
  30
  31 #include "common.h"
  32
  33 #include <linux/kthread.h>
  34 #include <linux/ethtool.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/if_vlan.h>
  37 #include <linux/vmalloc.h>
  38
  39 #include <xen/events.h>
  40 #include <asm/xen/hypercall.h>
  41 #include <xen/balloon.h>
  42
  43 #define XENVIF_QUEUE_LENGTH 32
  44 #define XENVIF_NAPI_WEIGHT  64
  45
  46 /* Number of bytes allowed on the internal guest Rx queue. */
  47 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
  48
  49 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
  50  * increasing the inflight counter. We need to increase the inflight
  51  * counter because core driver calls into xenvif_zerocopy_callback
  52  * which calls xenvif_skb_zerocopy_complete.
  53  */
  54 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
  55                                  struct sk_buff *skb)
  56 {
  57         skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
  58         atomic_inc(&queue->inflight_packets);
  59 }
  60
  61 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
  62 {
  63         atomic_dec(&queue->inflight_packets);
  64
  65         /* Wake the dealloc thread _after_ decrementing inflight_packets so
  66          * that if kthread_stop() has already been called, the dealloc thread
  67          * does not wait forever with nothing to wake it.
  68          */
  69         wake_up(&queue->dealloc_wq);
  70 }
  71
  72 int xenvif_schedulable(struct xenvif *vif)
  73 {
  74         return netif_running(vif->dev) &&
  75                 test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
  76                 !vif->disabled;
  77 }
  78
  79 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
  80 {
  81         struct xenvif_queue *queue = dev_id;
  82
  83         if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
  84                 napi_schedule(&queue->napi);
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 static int xenvif_poll(struct napi_struct *napi, int budget)
  90 {
  91         struct xenvif_queue *queue =
  92                 container_of(napi, struct xenvif_queue, napi);
  93         int work_done;
  94
  95         /* This vif is rogue, we pretend we've there is nothing to do
  96          * for this vif to deschedule it from NAPI. But this interface
  97          * will be turned off in thread context later.
  98          */
  99         if (unlikely(queue->vif->disabled)) {
 100                 napi_complete(napi);
 101                 return 0;
 102         }
 103
 104         work_done = xenvif_tx_action(queue, budget);
 105
 106         if (work_done < budget) {
 107                 napi_complete(napi);
 108                 xenvif_napi_schedule_or_enable_events(queue);
 109         }
 110
 111         return work_done;
 112 }
 113
 114 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 115 {
 116         struct xenvif_queue *queue = dev_id;
 117
 118         xenvif_kick_thread(queue);
 119
 120         return IRQ_HANDLED;
 121 }
 122
 123 irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 124 {
 125         xenvif_tx_interrupt(irq, dev_id);
 126         xenvif_rx_interrupt(irq, dev_id);
 127
 128         return IRQ_HANDLED;
 129 }
 130
 131 irqreturn_t xenvif_ctrl_interrupt(int irq, void *dev_id)
 132 {
 133         struct xenvif *vif = dev_id;
 134
 135         wake_up(&vif->ctrl_wq);
 136
 137         return IRQ_HANDLED;
 138 }
 139
 140 int xenvif_queue_stopped(struct xenvif_queue *queue)
 141 {
 142         struct net_device *dev = queue->vif->dev;
 143         unsigned int id = queue->id;
 144         return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
 145 }
 146
 147 void xenvif_wake_queue(struct xenvif_queue *queue)
 148 {
 149         struct net_device *dev = queue->vif->dev;
 150         unsigned int id = queue->id;
 151         netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
 152 }
 153
 154 static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb,
 155                                void *accel_priv,
 156                                select_queue_fallback_t fallback)
 157 {
 158         struct xenvif *vif = netdev_priv(dev);
 159         unsigned int size = vif->hash.size;
 160
 161         if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) {
 162                 u16 index = fallback(dev, skb) % dev->real_num_tx_queues;
 163
 164                 /* Make sure there is no hash information in the socket
 165                  * buffer otherwise it would be incorrectly forwarded
 166                  * to the frontend.
 167                  */
 168                 skb_clear_hash(skb);
 169
 170                 return index;
 171         }
 172
 173         xenvif_set_skb_hash(vif, skb);
 174
 175         if (size == 0)
 176                 return skb_get_hash_raw(skb) % dev->real_num_tx_queues;
 177
 178         return vif->hash.mapping[skb_get_hash_raw(skb) % size];
 179 }
 180
 181 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 182 {
 183         struct xenvif *vif = netdev_priv(dev);
 184         struct xenvif_queue *queue = NULL;
 185         unsigned int num_queues = vif->num_queues;
 186         u16 index;
 187         struct xenvif_rx_cb *cb;
 188
 189         BUG_ON(skb->dev != dev);
 190
 191         /* Drop the packet if queues are not set up */
 192         if (num_queues < 1)
 193                 goto drop;
 194
 195         /* Obtain the queue to be used to transmit this packet */
 196         index = skb_get_queue_mapping(skb);
 197         if (index >= num_queues) {
 198                 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
 199                                     index, vif->dev->name);
 200                 index %= num_queues;
 201         }
 202         queue = &vif->queues[index];
 203
 204         /* Drop the packet if queue is not ready */
 205         if (queue->task == NULL ||
 206             queue->dealloc_task == NULL ||
 207             !xenvif_schedulable(vif))
 208                 goto drop;
 209
 210         if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
 211                 struct ethhdr *eth = (struct ethhdr *)skb->data;
 212
 213                 if (!xenvif_mcast_match(vif, eth->h_dest))
 214                         goto drop;
 215         }
 216
 217         cb = XENVIF_RX_CB(skb);
 218         cb->expires = jiffies + vif->drain_timeout;
 219
 220         xenvif_rx_queue_tail(queue, skb);
 221         xenvif_kick_thread(queue);
 222
 223         return NETDEV_TX_OK;
 224
 225  drop:
 226         vif->dev->stats.tx_dropped++;
 227         dev_kfree_skb(skb);
 228         return NETDEV_TX_OK;
 229 }
 230
 231 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 232 {
 233         struct xenvif *vif = netdev_priv(dev);
 234         struct xenvif_queue *queue = NULL;
 235         unsigned int num_queues = vif->num_queues;
 236         unsigned long rx_bytes = 0;
 237         unsigned long rx_packets = 0;
 238         unsigned long tx_bytes = 0;
 239         unsigned long tx_packets = 0;
 240         unsigned int index;
 241
 242         if (vif->queues == NULL)
 243                 goto out;
 244
 245         /* Aggregate tx and rx stats from each queue */
 246         for (index = 0; index < num_queues; ++index) {
 247                 queue = &vif->queues[index];
 248                 rx_bytes += queue->stats.rx_bytes;
 249                 rx_packets += queue->stats.rx_packets;
 250                 tx_bytes += queue->stats.tx_bytes;
 251                 tx_packets += queue->stats.tx_packets;
 252         }
 253
 254 out:
 255         vif->dev->stats.rx_bytes = rx_bytes;
 256         vif->dev->stats.rx_packets = rx_packets;
 257         vif->dev->stats.tx_bytes = tx_bytes;
 258         vif->dev->stats.tx_packets = tx_packets;
 259
 260         return &vif->dev->stats;
 261 }
 262
 263 static void xenvif_up(struct xenvif *vif)
 264 {
 265         struct xenvif_queue *queue = NULL;
 266         unsigned int num_queues = vif->num_queues;
 267         unsigned int queue_index;
 268
 269         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 270                 queue = &vif->queues[queue_index];
 271                 napi_enable(&queue->napi);
 272                 enable_irq(queue->tx_irq);
 273                 if (queue->tx_irq != queue->rx_irq)
 274                         enable_irq(queue->rx_irq);
 275                 xenvif_napi_schedule_or_enable_events(queue);
 276         }
 277 }
 278
 279 static void xenvif_down(struct xenvif *vif)
 280 {
 281         struct xenvif_queue *queue = NULL;
 282         unsigned int num_queues = vif->num_queues;
 283         unsigned int queue_index;
 284
 285         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 286                 queue = &vif->queues[queue_index];
 287                 disable_irq(queue->tx_irq);
 288                 if (queue->tx_irq != queue->rx_irq)
 289                         disable_irq(queue->rx_irq);
 290                 napi_disable(&queue->napi);
 291                 del_timer_sync(&queue->credit_timeout);
 292         }
 293 }
 294
 295 static int xenvif_open(struct net_device *dev)
 296 {
 297         struct xenvif *vif = netdev_priv(dev);
 298         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 299                 xenvif_up(vif);
 300         netif_tx_start_all_queues(dev);
 301         return 0;
 302 }
 303
 304 static int xenvif_close(struct net_device *dev)
 305 {
 306         struct xenvif *vif = netdev_priv(dev);
 307         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 308                 xenvif_down(vif);
 309         netif_tx_stop_all_queues(dev);
 310         return 0;
 311 }
 312
 313 static int xenvif_change_mtu(struct net_device *dev, int mtu)
 314 {
 315         struct xenvif *vif = netdev_priv(dev);
 316         int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
 317
 318         if (mtu > max)
 319                 return -EINVAL;
 320         dev->mtu = mtu;
 321         return 0;
 322 }
 323
 324 static netdev_features_t xenvif_fix_features(struct net_device *dev,
 325         netdev_features_t features)
 326 {
 327         struct xenvif *vif = netdev_priv(dev);
 328
 329         if (!vif->can_sg)
 330                 features &= ~NETIF_F_SG;
 331         if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
 332                 features &= ~NETIF_F_TSO;
 333         if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
 334                 features &= ~NETIF_F_TSO6;
 335         if (!vif->ip_csum)
 336                 features &= ~NETIF_F_IP_CSUM;
 337         if (!vif->ipv6_csum)
 338                 features &= ~NETIF_F_IPV6_CSUM;
 339
 340         return features;
 341 }
 342
 343 static const struct xenvif_stat {
 344         char name[ETH_GSTRING_LEN];
 345         u16 offset;
 346 } xenvif_stats[] = {
 347         {
 348                 "rx_gso_checksum_fixup",
 349                 offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
 350         },
 351         /* If (sent != success + fail), there are probably packets never
 352          * freed up properly!
 353          */
 354         {
 355                 "tx_zerocopy_sent",
 356                 offsetof(struct xenvif_stats, tx_zerocopy_sent),
 357         },
 358         {
 359                 "tx_zerocopy_success",
 360                 offsetof(struct xenvif_stats, tx_zerocopy_success),
 361         },
 362         {
 363                 "tx_zerocopy_fail",
 364                 offsetof(struct xenvif_stats, tx_zerocopy_fail)
 365         },
 366         /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
 367          * a guest with the same MAX_SKB_FRAG
 368          */
 369         {
 370                 "tx_frag_overflow",
 371                 offsetof(struct xenvif_stats, tx_frag_overflow)
 372         },
 373 };
 374
 375 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
 376 {
 377         switch (string_set) {
 378         case ETH_SS_STATS:
 379                 return ARRAY_SIZE(xenvif_stats);
 380         default:
 381                 return -EINVAL;
 382         }
 383 }
 384
 385 static void xenvif_get_ethtool_stats(struct net_device *dev,
 386                                      struct ethtool_stats *stats, u64 * data)
 387 {
 388         struct xenvif *vif = netdev_priv(dev);
 389         unsigned int num_queues = vif->num_queues;
 390         int i;
 391         unsigned int queue_index;
 392
 393         for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
 394                 unsigned long accum = 0;
 395                 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 396                         void *vif_stats = &vif->queues[queue_index].stats;
 397                         accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
 398                 }
 399                 data[i] = accum;
 400         }
 401 }
 402
 403 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
 404 {
 405         int i;
 406
 407         switch (stringset) {
 408         case ETH_SS_STATS:
 409                 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
 410                         memcpy(data + i * ETH_GSTRING_LEN,
 411                                xenvif_stats[i].name, ETH_GSTRING_LEN);
 412                 break;
 413         }
 414 }
 415
 416 static const struct ethtool_ops xenvif_ethtool_ops = {
 417         .get_link       = ethtool_op_get_link,
 418
 419         .get_sset_count = xenvif_get_sset_count,
 420         .get_ethtool_stats = xenvif_get_ethtool_stats,
 421         .get_strings = xenvif_get_strings,
 422 };
 423
 424 static const struct net_device_ops xenvif_netdev_ops = {
 425         .ndo_select_queue = xenvif_select_queue,
 426         .ndo_start_xmit = xenvif_start_xmit,
 427         .ndo_get_stats  = xenvif_get_stats,
 428         .ndo_open       = xenvif_open,
 429         .ndo_stop       = xenvif_close,
 430         .ndo_change_mtu = xenvif_change_mtu,
 431         .ndo_fix_features = xenvif_fix_features,
 432         .ndo_set_mac_address = eth_mac_addr,
 433         .ndo_validate_addr   = eth_validate_addr,
 434 };
 435
 436 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 437                             unsigned int handle)
 438 {
 439         int err;
 440         struct net_device *dev;
 441         struct xenvif *vif;
 442         char name[IFNAMSIZ] = {};
 443
 444         snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
 445         /* Allocate a netdev with the max. supported number of queues.
 446          * When the guest selects the desired number, it will be updated
 447          * via netif_set_real_num_*_queues().
 448          */
 449         dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
 450                               ether_setup, xenvif_max_queues);
 451         if (dev == NULL) {
 452                 pr_warn("Could not allocate netdev for %s\n", name);
 453                 return ERR_PTR(-ENOMEM);
 454         }
 455
 456         SET_NETDEV_DEV(dev, parent);
 457
 458         vif = netdev_priv(dev);
 459
 460         vif->domid  = domid;
 461         vif->handle = handle;
 462         vif->can_sg = 1;
 463         vif->ip_csum = 1;
 464         vif->dev = dev;
 465         vif->disabled = false;
 466         vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
 467         vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
 468
 469         /* Start out with no queues. */
 470         vif->queues = NULL;
 471         vif->num_queues = 0;
 472
 473         spin_lock_init(&vif->lock);
 474         INIT_LIST_HEAD(&vif->fe_mcast_addr);
 475
 476         dev->netdev_ops = &xenvif_netdev_ops;
 477         dev->hw_features = NETIF_F_SG |
 478                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 479                 NETIF_F_TSO | NETIF_F_TSO6;
 480         dev->features = dev->hw_features | NETIF_F_RXCSUM;
 481         dev->ethtool_ops = &xenvif_ethtool_ops;
 482
 483         dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
 484
 485         /*
 486          * Initialise a dummy MAC address. We choose the numerically
 487          * largest non-broadcast address to prevent the address getting
 488          * stolen by an Ethernet bridge for STP purposes.
 489          * (FE:FF:FF:FF:FF:FF)
 490          */
 491         eth_broadcast_addr(dev->dev_addr);
 492         dev->dev_addr[0] &= ~0x01;
 493
 494         netif_carrier_off(dev);
 495
 496         err = register_netdev(dev);
 497         if (err) {
 498                 netdev_warn(dev, "Could not register device: err=%d\n", err);
 499                 free_netdev(dev);
 500                 return ERR_PTR(err);
 501         }
 502
 503         netdev_dbg(dev, "Successfully created xenvif\n");
 504
 505         __module_get(THIS_MODULE);
 506
 507         return vif;
 508 }
 509
 510 int xenvif_init_queue(struct xenvif_queue *queue)
 511 {
 512         int err, i;
 513
 514         queue->credit_bytes = queue->remaining_credit = ~0UL;
 515         queue->credit_usec  = 0UL;
 516         init_timer(&queue->credit_timeout);
 517         queue->credit_timeout.function = xenvif_tx_credit_callback;
 518         queue->credit_window_start = get_jiffies_64();
 519
 520         queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
 521
 522         skb_queue_head_init(&queue->rx_queue);
 523         skb_queue_head_init(&queue->tx_queue);
 524
 525         queue->pending_cons = 0;
 526         queue->pending_prod = MAX_PENDING_REQS;
 527         for (i = 0; i < MAX_PENDING_REQS; ++i)
 528                 queue->pending_ring[i] = i;
 529
 530         spin_lock_init(&queue->callback_lock);
 531         spin_lock_init(&queue->response_lock);
 532
 533         /* If ballooning is disabled, this will consume real memory, so you
 534          * better enable it. The long term solution would be to use just a
 535          * bunch of valid page descriptors, without dependency on ballooning
 536          */
 537         err = gnttab_alloc_pages(MAX_PENDING_REQS,
 538                                  queue->mmap_pages);
 539         if (err) {
 540                 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
 541                 return -ENOMEM;
 542         }
 543
 544         for (i = 0; i < MAX_PENDING_REQS; i++) {
 545                 queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
 546                         { .callback = xenvif_zerocopy_callback,
 547                           .ctx = NULL,
 548                           .desc = i };
 549                 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
 550         }
 551
 552         return 0;
 553 }
 554
 555 void xenvif_carrier_on(struct xenvif *vif)
 556 {
 557         rtnl_lock();
 558         if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
 559                 dev_set_mtu(vif->dev, ETH_DATA_LEN);
 560         netdev_update_features(vif->dev);
 561         set_bit(VIF_STATUS_CONNECTED, &vif->status);
 562         if (netif_running(vif->dev))
 563                 xenvif_up(vif);
 564         rtnl_unlock();
 565 }
 566
 567 int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 568                         unsigned int evtchn)
 569 {
 570         struct net_device *dev = vif->dev;
 571         void *addr;
 572         struct xen_netif_ctrl_sring *shared;
 573         struct task_struct *task;
 574         int err = -ENOMEM;
 575
 576         err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
 577                                      &ring_ref, 1, &addr);
 578         if (err)
 579                 goto err;
 580
 581         shared = (struct xen_netif_ctrl_sring *)addr;
 582         BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE);
 583
 584         init_waitqueue_head(&vif->ctrl_wq);
 585
 586         err = bind_interdomain_evtchn_to_irqhandler(vif->domid, evtchn,
 587                                                     xenvif_ctrl_interrupt,
 588                                                     0, dev->name, vif);
 589         if (err < 0)
 590                 goto err_unmap;
 591
 592         vif->ctrl_irq = err;
 593
 594         xenvif_init_hash(vif);
 595
 596         task = kthread_create(xenvif_ctrl_kthread, (void *)vif,
 597                               "%s-control", dev->name);
 598         if (IS_ERR(task)) {
 599                 pr_warn("Could not allocate kthread for %s\n", dev->name);
 600                 err = PTR_ERR(task);
 601                 goto err_deinit;
 602         }
 603
 604         get_task_struct(task);
 605         vif->ctrl_task = task;
 606
 607         wake_up_process(vif->ctrl_task);
 608
 609         return 0;
 610
 611 err_deinit:
 612         xenvif_deinit_hash(vif);
 613         unbind_from_irqhandler(vif->ctrl_irq, vif);
 614         vif->ctrl_irq = 0;
 615
 616 err_unmap:
 617         xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
 618                                 vif->ctrl.sring);
 619         vif->ctrl.sring = NULL;
 620
 621 err:
 622         return err;
 623 }
 624
 625 int xenvif_connect_data(struct xenvif_queue *queue,
 626                         unsigned long tx_ring_ref,
 627                         unsigned long rx_ring_ref,
 628                         unsigned int tx_evtchn,
 629                         unsigned int rx_evtchn)
 630 {
 631         struct task_struct *task;
 632         int err = -ENOMEM;
 633
 634         BUG_ON(queue->tx_irq);
 635         BUG_ON(queue->task);
 636         BUG_ON(queue->dealloc_task);
 637
 638         err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
 639                                              rx_ring_ref);
 640         if (err < 0)
 641                 goto err;
 642
 643         init_waitqueue_head(&queue->wq);
 644         init_waitqueue_head(&queue->dealloc_wq);
 645         atomic_set(&queue->inflight_packets, 0);
 646
 647         netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
 648                         XENVIF_NAPI_WEIGHT);
 649
 650         if (tx_evtchn == rx_evtchn) {
 651                 /* feature-split-event-channels == 0 */
 652                 err = bind_interdomain_evtchn_to_irqhandler(
 653                         queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
 654                         queue->name, queue);
 655                 if (err < 0)
 656                         goto err_unmap;
 657                 queue->tx_irq = queue->rx_irq = err;
 658                 disable_irq(queue->tx_irq);
 659         } else {
 660                 /* feature-split-event-channels == 1 */
 661                 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
 662                          "%s-tx", queue->name);
 663                 err = bind_interdomain_evtchn_to_irqhandler(
 664                         queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
 665                         queue->tx_irq_name, queue);
 666                 if (err < 0)
 667                         goto err_unmap;
 668                 queue->tx_irq = err;
 669                 disable_irq(queue->tx_irq);
 670
 671                 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
 672                          "%s-rx", queue->name);
 673                 err = bind_interdomain_evtchn_to_irqhandler(
 674                         queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
 675                         queue->rx_irq_name, queue);
 676                 if (err < 0)
 677                         goto err_tx_unbind;
 678                 queue->rx_irq = err;
 679                 disable_irq(queue->rx_irq);
 680         }
 681
 682         queue->stalled = true;
 683
 684         task = kthread_create(xenvif_kthread_guest_rx,
 685                               (void *)queue, "%s-guest-rx", queue->name);
 686         if (IS_ERR(task)) {
 687                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 688                 err = PTR_ERR(task);
 689                 goto err_rx_unbind;
 690         }
 691         queue->task = task;
 692         get_task_struct(task);
 693
 694         task = kthread_create(xenvif_dealloc_kthread,
 695                               (void *)queue, "%s-dealloc", queue->name);
 696         if (IS_ERR(task)) {
 697                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 698                 err = PTR_ERR(task);
 699                 goto err_rx_unbind;
 700         }
 701         queue->dealloc_task = task;
 702
 703         wake_up_process(queue->task);
 704         wake_up_process(queue->dealloc_task);
 705
 706         return 0;
 707
 708 err_rx_unbind:
 709         unbind_from_irqhandler(queue->rx_irq, queue);
 710         queue->rx_irq = 0;
 711 err_tx_unbind:
 712         unbind_from_irqhandler(queue->tx_irq, queue);
 713         queue->tx_irq = 0;
 714 err_unmap:
 715         xenvif_unmap_frontend_data_rings(queue);
 716         netif_napi_del(&queue->napi);
 717 err:
 718         module_put(THIS_MODULE);
 719         return err;
 720 }
 721
 722 void xenvif_carrier_off(struct xenvif *vif)
 723 {
 724         struct net_device *dev = vif->dev;
 725
 726         rtnl_lock();
 727         if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
 728                 netif_carrier_off(dev); /* discard queued packets */
 729                 if (netif_running(dev))
 730                         xenvif_down(vif);
 731         }
 732         rtnl_unlock();
 733 }
 734
 735 void xenvif_disconnect_data(struct xenvif *vif)
 736 {
 737         struct xenvif_queue *queue = NULL;
 738         unsigned int num_queues = vif->num_queues;
 739         unsigned int queue_index;
 740
 741         xenvif_carrier_off(vif);
 742
 743         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 744                 queue = &vif->queues[queue_index];
 745
 746                 netif_napi_del(&queue->napi);
 747
 748                 if (queue->task) {
 749                         kthread_stop(queue->task);
 750                         put_task_struct(queue->task);
 751                         queue->task = NULL;
 752                 }
 753
 754                 if (queue->dealloc_task) {
 755                         kthread_stop(queue->dealloc_task);
 756                         queue->dealloc_task = NULL;
 757                 }
 758
 759                 if (queue->tx_irq) {
 760                         if (queue->tx_irq == queue->rx_irq)
 761                                 unbind_from_irqhandler(queue->tx_irq, queue);
 762                         else {
 763                                 unbind_from_irqhandler(queue->tx_irq, queue);
 764                                 unbind_from_irqhandler(queue->rx_irq, queue);
 765                         }
 766                         queue->tx_irq = 0;
 767                 }
 768
 769                 xenvif_unmap_frontend_data_rings(queue);
 770         }
 771
 772         xenvif_mcast_addr_list_free(vif);
 773 }
 774
 775 void xenvif_disconnect_ctrl(struct xenvif *vif)
 776 {
 777         if (vif->ctrl_task) {
 778                 kthread_stop(vif->ctrl_task);
 779                 put_task_struct(vif->ctrl_task);
 780                 vif->ctrl_task = NULL;
 781         }
 782
 783         if (vif->ctrl_irq) {
 784                 xenvif_deinit_hash(vif);
 785                 unbind_from_irqhandler(vif->ctrl_irq, vif);
 786                 vif->ctrl_irq = 0;
 787         }
 788
 789         if (vif->ctrl.sring) {
 790                 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
 791                                         vif->ctrl.sring);
 792                 vif->ctrl.sring = NULL;
 793         }
 794 }
 795
 796 /* Reverse the relevant parts of xenvif_init_queue().
 797  * Used for queue teardown from xenvif_free(), and on the
 798  * error handling paths in xenbus.c:connect().
 799  */
 800 void xenvif_deinit_queue(struct xenvif_queue *queue)
 801 {
 802         gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
 803 }
 804
 805 void xenvif_free(struct xenvif *vif)
 806 {
 807         struct xenvif_queue *queues = vif->queues;
 808         unsigned int num_queues = vif->num_queues;
 809         unsigned int queue_index;
 810
 811         unregister_netdev(vif->dev);
 812         free_netdev(vif->dev);
 813
 814         for (queue_index = 0; queue_index < num_queues; ++queue_index)
 815                 xenvif_deinit_queue(&queues[queue_index]);
 816         vfree(queues);
 817
 818         module_put(THIS_MODULE);
 819 }