drivers/net/xen-netback/interface.c

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

DEFINITIONS
