linux/drivers/net/xen-netfront.c
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   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#include <linux/module.h>
  33#include <linux/kernel.h>
  34#include <linux/netdevice.h>
  35#include <linux/etherdevice.h>
  36#include <linux/skbuff.h>
  37#include <linux/ethtool.h>
  38#include <linux/if_ether.h>
  39#include <net/tcp.h>
  40#include <linux/udp.h>
  41#include <linux/moduleparam.h>
  42#include <linux/mm.h>
  43#include <linux/slab.h>
  44#include <net/ip.h>
  45
  46#include <asm/xen/page.h>
  47#include <xen/xen.h>
  48#include <xen/xenbus.h>
  49#include <xen/events.h>
  50#include <xen/page.h>
  51#include <xen/platform_pci.h>
  52#include <xen/grant_table.h>
  53
  54#include <xen/interface/io/netif.h>
  55#include <xen/interface/memory.h>
  56#include <xen/interface/grant_table.h>
  57
  58static const struct ethtool_ops xennet_ethtool_ops;
  59
  60struct netfront_cb {
  61        int pull_to;
  62};
  63
  64#define NETFRONT_SKB_CB(skb)    ((struct netfront_cb *)((skb)->cb))
  65
  66#define RX_COPY_THRESHOLD 256
  67
  68#define GRANT_INVALID_REF       0
  69
  70#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
  71#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
  72#define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
  73
  74struct netfront_stats {
  75        u64                     rx_packets;
  76        u64                     tx_packets;
  77        u64                     rx_bytes;
  78        u64                     tx_bytes;
  79        struct u64_stats_sync   syncp;
  80};
  81
  82struct netfront_info {
  83        struct list_head list;
  84        struct net_device *netdev;
  85
  86        struct napi_struct napi;
  87
  88        unsigned int evtchn;
  89        struct xenbus_device *xbdev;
  90
  91        spinlock_t   tx_lock;
  92        struct xen_netif_tx_front_ring tx;
  93        int tx_ring_ref;
  94
  95        /*
  96         * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
  97         * are linked from tx_skb_freelist through skb_entry.link.
  98         *
  99         *  NB. Freelist index entries are always going to be less than
 100         *  PAGE_OFFSET, whereas pointers to skbs will always be equal or
 101         *  greater than PAGE_OFFSET: we use this property to distinguish
 102         *  them.
 103         */
 104        union skb_entry {
 105                struct sk_buff *skb;
 106                unsigned long link;
 107        } tx_skbs[NET_TX_RING_SIZE];
 108        grant_ref_t gref_tx_head;
 109        grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
 110        unsigned tx_skb_freelist;
 111
 112        spinlock_t   rx_lock ____cacheline_aligned_in_smp;
 113        struct xen_netif_rx_front_ring rx;
 114        int rx_ring_ref;
 115
 116        /* Receive-ring batched refills. */
 117#define RX_MIN_TARGET 8
 118#define RX_DFL_MIN_TARGET 64
 119#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
 120        unsigned rx_min_target, rx_max_target, rx_target;
 121        struct sk_buff_head rx_batch;
 122
 123        struct timer_list rx_refill_timer;
 124
 125        struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
 126        grant_ref_t gref_rx_head;
 127        grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
 128
 129        unsigned long rx_pfn_array[NET_RX_RING_SIZE];
 130        struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
 131        struct mmu_update rx_mmu[NET_RX_RING_SIZE];
 132
 133        /* Statistics */
 134        struct netfront_stats __percpu *stats;
 135
 136        unsigned long rx_gso_checksum_fixup;
 137};
 138
 139struct netfront_rx_info {
 140        struct xen_netif_rx_response rx;
 141        struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
 142};
 143
 144static void skb_entry_set_link(union skb_entry *list, unsigned short id)
 145{
 146        list->link = id;
 147}
 148
 149static int skb_entry_is_link(const union skb_entry *list)
 150{
 151        BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
 152        return (unsigned long)list->skb < PAGE_OFFSET;
 153}
 154
 155/*
 156 * Access macros for acquiring freeing slots in tx_skbs[].
 157 */
 158
 159static void add_id_to_freelist(unsigned *head, union skb_entry *list,
 160                               unsigned short id)
 161{
 162        skb_entry_set_link(&list[id], *head);
 163        *head = id;
 164}
 165
 166static unsigned short get_id_from_freelist(unsigned *head,
 167                                           union skb_entry *list)
 168{
 169        unsigned int id = *head;
 170        *head = list[id].link;
 171        return id;
 172}
 173
 174static int xennet_rxidx(RING_IDX idx)
 175{
 176        return idx & (NET_RX_RING_SIZE - 1);
 177}
 178
 179static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
 180                                         RING_IDX ri)
 181{
 182        int i = xennet_rxidx(ri);
 183        struct sk_buff *skb = np->rx_skbs[i];
 184        np->rx_skbs[i] = NULL;
 185        return skb;
 186}
 187
 188static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
 189                                            RING_IDX ri)
 190{
 191        int i = xennet_rxidx(ri);
 192        grant_ref_t ref = np->grant_rx_ref[i];
 193        np->grant_rx_ref[i] = GRANT_INVALID_REF;
 194        return ref;
 195}
 196
 197#ifdef CONFIG_SYSFS
 198static int xennet_sysfs_addif(struct net_device *netdev);
 199static void xennet_sysfs_delif(struct net_device *netdev);
 200#else /* !CONFIG_SYSFS */
 201#define xennet_sysfs_addif(dev) (0)
 202#define xennet_sysfs_delif(dev) do { } while (0)
 203#endif
 204
 205static bool xennet_can_sg(struct net_device *dev)
 206{
 207        return dev->features & NETIF_F_SG;
 208}
 209
 210
 211static void rx_refill_timeout(unsigned long data)
 212{
 213        struct net_device *dev = (struct net_device *)data;
 214        struct netfront_info *np = netdev_priv(dev);
 215        napi_schedule(&np->napi);
 216}
 217
 218static int netfront_tx_slot_available(struct netfront_info *np)
 219{
 220        return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
 221                (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
 222}
 223
 224static void xennet_maybe_wake_tx(struct net_device *dev)
 225{
 226        struct netfront_info *np = netdev_priv(dev);
 227
 228        if (unlikely(netif_queue_stopped(dev)) &&
 229            netfront_tx_slot_available(np) &&
 230            likely(netif_running(dev)))
 231                netif_wake_queue(dev);
 232}
 233
 234static void xennet_alloc_rx_buffers(struct net_device *dev)
 235{
 236        unsigned short id;
 237        struct netfront_info *np = netdev_priv(dev);
 238        struct sk_buff *skb;
 239        struct page *page;
 240        int i, batch_target, notify;
 241        RING_IDX req_prod = np->rx.req_prod_pvt;
 242        grant_ref_t ref;
 243        unsigned long pfn;
 244        void *vaddr;
 245        struct xen_netif_rx_request *req;
 246
 247        if (unlikely(!netif_carrier_ok(dev)))
 248                return;
 249
 250        /*
 251         * Allocate skbuffs greedily, even though we batch updates to the
 252         * receive ring. This creates a less bursty demand on the memory
 253         * allocator, so should reduce the chance of failed allocation requests
 254         * both for ourself and for other kernel subsystems.
 255         */
 256        batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
 257        for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
 258                skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
 259                                         GFP_ATOMIC | __GFP_NOWARN);
 260                if (unlikely(!skb))
 261                        goto no_skb;
 262
 263                /* Align ip header to a 16 bytes boundary */
 264                skb_reserve(skb, NET_IP_ALIGN);
 265
 266                page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
 267                if (!page) {
 268                        kfree_skb(skb);
 269no_skb:
 270                        /* Any skbuffs queued for refill? Force them out. */
 271                        if (i != 0)
 272                                goto refill;
 273                        /* Could not allocate any skbuffs. Try again later. */
 274                        mod_timer(&np->rx_refill_timer,
 275                                  jiffies + (HZ/10));
 276                        break;
 277                }
 278
 279                __skb_fill_page_desc(skb, 0, page, 0, 0);
 280                skb_shinfo(skb)->nr_frags = 1;
 281                __skb_queue_tail(&np->rx_batch, skb);
 282        }
 283
 284        /* Is the batch large enough to be worthwhile? */
 285        if (i < (np->rx_target/2)) {
 286                if (req_prod > np->rx.sring->req_prod)
 287                        goto push;
 288                return;
 289        }
 290
 291        /* Adjust our fill target if we risked running out of buffers. */
 292        if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
 293            ((np->rx_target *= 2) > np->rx_max_target))
 294                np->rx_target = np->rx_max_target;
 295
 296 refill:
 297        for (i = 0; ; i++) {
 298                skb = __skb_dequeue(&np->rx_batch);
 299                if (skb == NULL)
 300                        break;
 301
 302                skb->dev = dev;
 303
 304                id = xennet_rxidx(req_prod + i);
 305
 306                BUG_ON(np->rx_skbs[id]);
 307                np->rx_skbs[id] = skb;
 308
 309                ref = gnttab_claim_grant_reference(&np->gref_rx_head);
 310                BUG_ON((signed short)ref < 0);
 311                np->grant_rx_ref[id] = ref;
 312
 313                pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
 314                vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
 315
 316                req = RING_GET_REQUEST(&np->rx, req_prod + i);
 317                gnttab_grant_foreign_access_ref(ref,
 318                                                np->xbdev->otherend_id,
 319                                                pfn_to_mfn(pfn),
 320                                                0);
 321
 322                req->id = id;
 323                req->gref = ref;
 324        }
 325
 326        wmb();          /* barrier so backend seens requests */
 327
 328        /* Above is a suitable barrier to ensure backend will see requests. */
 329        np->rx.req_prod_pvt = req_prod + i;
 330 push:
 331        RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
 332        if (notify)
 333                notify_remote_via_irq(np->netdev->irq);
 334}
 335
 336static int xennet_open(struct net_device *dev)
 337{
 338        struct netfront_info *np = netdev_priv(dev);
 339
 340        napi_enable(&np->napi);
 341
 342        spin_lock_bh(&np->rx_lock);
 343        if (netif_carrier_ok(dev)) {
 344                xennet_alloc_rx_buffers(dev);
 345                np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
 346                if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
 347                        napi_schedule(&np->napi);
 348        }
 349        spin_unlock_bh(&np->rx_lock);
 350
 351        netif_start_queue(dev);
 352
 353        return 0;
 354}
 355
 356static void xennet_tx_buf_gc(struct net_device *dev)
 357{
 358        RING_IDX cons, prod;
 359        unsigned short id;
 360        struct netfront_info *np = netdev_priv(dev);
 361        struct sk_buff *skb;
 362
 363        BUG_ON(!netif_carrier_ok(dev));
 364
 365        do {
 366                prod = np->tx.sring->rsp_prod;
 367                rmb(); /* Ensure we see responses up to 'rp'. */
 368
 369                for (cons = np->tx.rsp_cons; cons != prod; cons++) {
 370                        struct xen_netif_tx_response *txrsp;
 371
 372                        txrsp = RING_GET_RESPONSE(&np->tx, cons);
 373                        if (txrsp->status == XEN_NETIF_RSP_NULL)
 374                                continue;
 375
 376                        id  = txrsp->id;
 377                        skb = np->tx_skbs[id].skb;
 378                        if (unlikely(gnttab_query_foreign_access(
 379                                np->grant_tx_ref[id]) != 0)) {
 380                                printk(KERN_ALERT "xennet_tx_buf_gc: warning "
 381                                       "-- grant still in use by backend "
 382                                       "domain.\n");
 383                                BUG();
 384                        }
 385                        gnttab_end_foreign_access_ref(
 386                                np->grant_tx_ref[id], GNTMAP_readonly);
 387                        gnttab_release_grant_reference(
 388                                &np->gref_tx_head, np->grant_tx_ref[id]);
 389                        np->grant_tx_ref[id] = GRANT_INVALID_REF;
 390                        add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
 391                        dev_kfree_skb_irq(skb);
 392                }
 393
 394                np->tx.rsp_cons = prod;
 395
 396                /*
 397                 * Set a new event, then check for race with update of tx_cons.
 398                 * Note that it is essential to schedule a callback, no matter
 399                 * how few buffers are pending. Even if there is space in the
 400                 * transmit ring, higher layers may be blocked because too much
 401                 * data is outstanding: in such cases notification from Xen is
 402                 * likely to be the only kick that we'll get.
 403                 */
 404                np->tx.sring->rsp_event =
 405                        prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
 406                mb();           /* update shared area */
 407        } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
 408
 409        xennet_maybe_wake_tx(dev);
 410}
 411
 412static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
 413                              struct xen_netif_tx_request *tx)
 414{
 415        struct netfront_info *np = netdev_priv(dev);
 416        char *data = skb->data;
 417        unsigned long mfn;
 418        RING_IDX prod = np->tx.req_prod_pvt;
 419        int frags = skb_shinfo(skb)->nr_frags;
 420        unsigned int offset = offset_in_page(data);
 421        unsigned int len = skb_headlen(skb);
 422        unsigned int id;
 423        grant_ref_t ref;
 424        int i;
 425
 426        /* While the header overlaps a page boundary (including being
 427           larger than a page), split it it into page-sized chunks. */
 428        while (len > PAGE_SIZE - offset) {
 429                tx->size = PAGE_SIZE - offset;
 430                tx->flags |= XEN_NETTXF_more_data;
 431                len -= tx->size;
 432                data += tx->size;
 433                offset = 0;
 434
 435                id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
 436                np->tx_skbs[id].skb = skb_get(skb);
 437                tx = RING_GET_REQUEST(&np->tx, prod++);
 438                tx->id = id;
 439                ref = gnttab_claim_grant_reference(&np->gref_tx_head);
 440                BUG_ON((signed short)ref < 0);
 441
 442                mfn = virt_to_mfn(data);
 443                gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
 444                                                mfn, GNTMAP_readonly);
 445
 446                tx->gref = np->grant_tx_ref[id] = ref;
 447                tx->offset = offset;
 448                tx->size = len;
 449                tx->flags = 0;
 450        }
 451
 452        /* Grant backend access to each skb fragment page. */
 453        for (i = 0; i < frags; i++) {
 454                skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 455                struct page *page = skb_frag_page(frag);
 456
 457                len = skb_frag_size(frag);
 458                offset = frag->page_offset;
 459
 460                /* Data must not cross a page boundary. */
 461                BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
 462
 463                /* Skip unused frames from start of page */
 464                page += offset >> PAGE_SHIFT;
 465                offset &= ~PAGE_MASK;
 466
 467                while (len > 0) {
 468                        unsigned long bytes;
 469
 470                        BUG_ON(offset >= PAGE_SIZE);
 471
 472                        bytes = PAGE_SIZE - offset;
 473                        if (bytes > len)
 474                                bytes = len;
 475
 476                        tx->flags |= XEN_NETTXF_more_data;
 477
 478                        id = get_id_from_freelist(&np->tx_skb_freelist,
 479                                                  np->tx_skbs);
 480                        np->tx_skbs[id].skb = skb_get(skb);
 481                        tx = RING_GET_REQUEST(&np->tx, prod++);
 482                        tx->id = id;
 483                        ref = gnttab_claim_grant_reference(&np->gref_tx_head);
 484                        BUG_ON((signed short)ref < 0);
 485
 486                        mfn = pfn_to_mfn(page_to_pfn(page));
 487                        gnttab_grant_foreign_access_ref(ref,
 488                                                        np->xbdev->otherend_id,
 489                                                        mfn, GNTMAP_readonly);
 490
 491                        tx->gref = np->grant_tx_ref[id] = ref;
 492                        tx->offset = offset;
 493                        tx->size = bytes;
 494                        tx->flags = 0;
 495
 496                        offset += bytes;
 497                        len -= bytes;
 498
 499                        /* Next frame */
 500                        if (offset == PAGE_SIZE && len) {
 501                                BUG_ON(!PageCompound(page));
 502                                page++;
 503                                offset = 0;
 504                        }
 505                }
 506        }
 507
 508        np->tx.req_prod_pvt = prod;
 509}
 510
 511/*
 512 * Count how many ring slots are required to send the frags of this
 513 * skb. Each frag might be a compound page.
 514 */
 515static int xennet_count_skb_frag_slots(struct sk_buff *skb)
 516{
 517        int i, frags = skb_shinfo(skb)->nr_frags;
 518        int pages = 0;
 519
 520        for (i = 0; i < frags; i++) {
 521                skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 522                unsigned long size = skb_frag_size(frag);
 523                unsigned long offset = frag->page_offset;
 524
 525                /* Skip unused frames from start of page */
 526                offset &= ~PAGE_MASK;
 527
 528                pages += PFN_UP(offset + size);
 529        }
 530
 531        return pages;
 532}
 533
 534static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 535{
 536        unsigned short id;
 537        struct netfront_info *np = netdev_priv(dev);
 538        struct netfront_stats *stats = this_cpu_ptr(np->stats);
 539        struct xen_netif_tx_request *tx;
 540        char *data = skb->data;
 541        RING_IDX i;
 542        grant_ref_t ref;
 543        unsigned long mfn;
 544        int notify;
 545        int slots;
 546        unsigned int offset = offset_in_page(data);
 547        unsigned int len = skb_headlen(skb);
 548        unsigned long flags;
 549
 550        /* If skb->len is too big for wire format, drop skb and alert
 551         * user about misconfiguration.
 552         */
 553        if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
 554                net_alert_ratelimited(
 555                        "xennet: skb->len = %u, too big for wire format\n",
 556                        skb->len);
 557                goto drop;
 558        }
 559
 560        slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
 561                xennet_count_skb_frag_slots(skb);
 562        if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
 563                net_alert_ratelimited(
 564                        "xennet: skb rides the rocket: %d slots\n", slots);
 565                goto drop;
 566        }
 567
 568        spin_lock_irqsave(&np->tx_lock, flags);
 569
 570        if (unlikely(!netif_carrier_ok(dev) ||
 571                     (slots > 1 && !xennet_can_sg(dev)) ||
 572                     netif_needs_gso(skb, netif_skb_features(skb)))) {
 573                spin_unlock_irqrestore(&np->tx_lock, flags);
 574                goto drop;
 575        }
 576
 577        i = np->tx.req_prod_pvt;
 578
 579        id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
 580        np->tx_skbs[id].skb = skb;
 581
 582        tx = RING_GET_REQUEST(&np->tx, i);
 583
 584        tx->id   = id;
 585        ref = gnttab_claim_grant_reference(&np->gref_tx_head);
 586        BUG_ON((signed short)ref < 0);
 587        mfn = virt_to_mfn(data);
 588        gnttab_grant_foreign_access_ref(
 589                ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
 590        tx->gref = np->grant_tx_ref[id] = ref;
 591        tx->offset = offset;
 592        tx->size = len;
 593
 594        tx->flags = 0;
 595        if (skb->ip_summed == CHECKSUM_PARTIAL)
 596                /* local packet? */
 597                tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
 598        else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
 599                /* remote but checksummed. */
 600                tx->flags |= XEN_NETTXF_data_validated;
 601
 602        if (skb_shinfo(skb)->gso_size) {
 603                struct xen_netif_extra_info *gso;
 604
 605                gso = (struct xen_netif_extra_info *)
 606                        RING_GET_REQUEST(&np->tx, ++i);
 607
 608                tx->flags |= XEN_NETTXF_extra_info;
 609
 610                gso->u.gso.size = skb_shinfo(skb)->gso_size;
 611                gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
 612                gso->u.gso.pad = 0;
 613                gso->u.gso.features = 0;
 614
 615                gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
 616                gso->flags = 0;
 617        }
 618
 619        np->tx.req_prod_pvt = i + 1;
 620
 621        xennet_make_frags(skb, dev, tx);
 622        tx->size = skb->len;
 623
 624        RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
 625        if (notify)
 626                notify_remote_via_irq(np->netdev->irq);
 627
 628        u64_stats_update_begin(&stats->syncp);
 629        stats->tx_bytes += skb->len;
 630        stats->tx_packets++;
 631        u64_stats_update_end(&stats->syncp);
 632
 633        /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
 634        xennet_tx_buf_gc(dev);
 635
 636        if (!netfront_tx_slot_available(np))
 637                netif_stop_queue(dev);
 638
 639        spin_unlock_irqrestore(&np->tx_lock, flags);
 640
 641        return NETDEV_TX_OK;
 642
 643 drop:
 644        dev->stats.tx_dropped++;
 645        dev_kfree_skb(skb);
 646        return NETDEV_TX_OK;
 647}
 648
 649static int xennet_close(struct net_device *dev)
 650{
 651        struct netfront_info *np = netdev_priv(dev);
 652        netif_stop_queue(np->netdev);
 653        napi_disable(&np->napi);
 654        return 0;
 655}
 656
 657static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
 658                                grant_ref_t ref)
 659{
 660        int new = xennet_rxidx(np->rx.req_prod_pvt);
 661
 662        BUG_ON(np->rx_skbs[new]);
 663        np->rx_skbs[new] = skb;
 664        np->grant_rx_ref[new] = ref;
 665        RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
 666        RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
 667        np->rx.req_prod_pvt++;
 668}
 669
 670static int xennet_get_extras(struct netfront_info *np,
 671                             struct xen_netif_extra_info *extras,
 672                             RING_IDX rp)
 673
 674{
 675        struct xen_netif_extra_info *extra;
 676        struct device *dev = &np->netdev->dev;
 677        RING_IDX cons = np->rx.rsp_cons;
 678        int err = 0;
 679
 680        do {
 681                struct sk_buff *skb;
 682                grant_ref_t ref;
 683
 684                if (unlikely(cons + 1 == rp)) {
 685                        if (net_ratelimit())
 686                                dev_warn(dev, "Missing extra info\n");
 687                        err = -EBADR;
 688                        break;
 689                }
 690
 691                extra = (struct xen_netif_extra_info *)
 692                        RING_GET_RESPONSE(&np->rx, ++cons);
 693
 694                if (unlikely(!extra->type ||
 695                             extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
 696                        if (net_ratelimit())
 697                                dev_warn(dev, "Invalid extra type: %d\n",
 698                                        extra->type);
 699                        err = -EINVAL;
 700                } else {
 701                        memcpy(&extras[extra->type - 1], extra,
 702                               sizeof(*extra));
 703                }
 704
 705                skb = xennet_get_rx_skb(np, cons);
 706                ref = xennet_get_rx_ref(np, cons);
 707                xennet_move_rx_slot(np, skb, ref);
 708        } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
 709
 710        np->rx.rsp_cons = cons;
 711        return err;
 712}
 713
 714static int xennet_get_responses(struct netfront_info *np,
 715                                struct netfront_rx_info *rinfo, RING_IDX rp,
 716                                struct sk_buff_head *list)
 717{
 718        struct xen_netif_rx_response *rx = &rinfo->rx;
 719        struct xen_netif_extra_info *extras = rinfo->extras;
 720        struct device *dev = &np->netdev->dev;
 721        RING_IDX cons = np->rx.rsp_cons;
 722        struct sk_buff *skb = xennet_get_rx_skb(np, cons);
 723        grant_ref_t ref = xennet_get_rx_ref(np, cons);
 724        int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
 725        int slots = 1;
 726        int err = 0;
 727        unsigned long ret;
 728
 729        if (rx->flags & XEN_NETRXF_extra_info) {
 730                err = xennet_get_extras(np, extras, rp);
 731                cons = np->rx.rsp_cons;
 732        }
 733
 734        for (;;) {
 735                if (unlikely(rx->status < 0 ||
 736                             rx->offset + rx->status > PAGE_SIZE)) {
 737                        if (net_ratelimit())
 738                                dev_warn(dev, "rx->offset: %x, size: %u\n",
 739                                         rx->offset, rx->status);
 740                        xennet_move_rx_slot(np, skb, ref);
 741                        err = -EINVAL;
 742                        goto next;
 743                }
 744
 745                /*
 746                 * This definitely indicates a bug, either in this driver or in
 747                 * the backend driver. In future this should flag the bad
 748                 * situation to the system controller to reboot the backend.
 749                 */
 750                if (ref == GRANT_INVALID_REF) {
 751                        if (net_ratelimit())
 752                                dev_warn(dev, "Bad rx response id %d.\n",
 753                                         rx->id);
 754                        err = -EINVAL;
 755                        goto next;
 756                }
 757
 758                ret = gnttab_end_foreign_access_ref(ref, 0);
 759                BUG_ON(!ret);
 760
 761                gnttab_release_grant_reference(&np->gref_rx_head, ref);
 762
 763                __skb_queue_tail(list, skb);
 764
 765next:
 766                if (!(rx->flags & XEN_NETRXF_more_data))
 767                        break;
 768
 769                if (cons + slots == rp) {
 770                        if (net_ratelimit())
 771                                dev_warn(dev, "Need more slots\n");
 772                        err = -ENOENT;
 773                        break;
 774                }
 775
 776                rx = RING_GET_RESPONSE(&np->rx, cons + slots);
 777                skb = xennet_get_rx_skb(np, cons + slots);
 778                ref = xennet_get_rx_ref(np, cons + slots);
 779                slots++;
 780        }
 781
 782        if (unlikely(slots > max)) {
 783                if (net_ratelimit())
 784                        dev_warn(dev, "Too many slots\n");
 785                err = -E2BIG;
 786        }
 787
 788        if (unlikely(err))
 789                np->rx.rsp_cons = cons + slots;
 790
 791        return err;
 792}
 793
 794static int xennet_set_skb_gso(struct sk_buff *skb,
 795                              struct xen_netif_extra_info *gso)
 796{
 797        if (!gso->u.gso.size) {
 798                if (net_ratelimit())
 799                        printk(KERN_WARNING "GSO size must not be zero.\n");
 800                return -EINVAL;
 801        }
 802
 803        /* Currently only TCPv4 S.O. is supported. */
 804        if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
 805                if (net_ratelimit())
 806                        printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type);
 807                return -EINVAL;
 808        }
 809
 810        skb_shinfo(skb)->gso_size = gso->u.gso.size;
 811        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 812
 813        /* Header must be checked, and gso_segs computed. */
 814        skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 815        skb_shinfo(skb)->gso_segs = 0;
 816
 817        return 0;
 818}
 819
 820static RING_IDX xennet_fill_frags(struct netfront_info *np,
 821                                  struct sk_buff *skb,
 822                                  struct sk_buff_head *list)
 823{
 824        struct skb_shared_info *shinfo = skb_shinfo(skb);
 825        int nr_frags = shinfo->nr_frags;
 826        RING_IDX cons = np->rx.rsp_cons;
 827        struct sk_buff *nskb;
 828
 829        while ((nskb = __skb_dequeue(list))) {
 830                struct xen_netif_rx_response *rx =
 831                        RING_GET_RESPONSE(&np->rx, ++cons);
 832                skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
 833
 834                __skb_fill_page_desc(skb, nr_frags,
 835                                     skb_frag_page(nfrag),
 836                                     rx->offset, rx->status);
 837
 838                skb->data_len += rx->status;
 839
 840                skb_shinfo(nskb)->nr_frags = 0;
 841                kfree_skb(nskb);
 842
 843                nr_frags++;
 844        }
 845
 846        shinfo->nr_frags = nr_frags;
 847        return cons;
 848}
 849
 850static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
 851{
 852        struct iphdr *iph;
 853        unsigned char *th;
 854        int err = -EPROTO;
 855        int recalculate_partial_csum = 0;
 856
 857        /*
 858         * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
 859         * peers can fail to set NETRXF_csum_blank when sending a GSO
 860         * frame. In this case force the SKB to CHECKSUM_PARTIAL and
 861         * recalculate the partial checksum.
 862         */
 863        if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
 864                struct netfront_info *np = netdev_priv(dev);
 865                np->rx_gso_checksum_fixup++;
 866                skb->ip_summed = CHECKSUM_PARTIAL;
 867                recalculate_partial_csum = 1;
 868        }
 869
 870        /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
 871        if (skb->ip_summed != CHECKSUM_PARTIAL)
 872                return 0;
 873
 874        if (skb->protocol != htons(ETH_P_IP))
 875                goto out;
 876
 877        iph = (void *)skb->data;
 878        th = skb->data + 4 * iph->ihl;
 879        if (th >= skb_tail_pointer(skb))
 880                goto out;
 881
 882        skb->csum_start = th - skb->head;
 883        switch (iph->protocol) {
 884        case IPPROTO_TCP:
 885                skb->csum_offset = offsetof(struct tcphdr, check);
 886
 887                if (recalculate_partial_csum) {
 888                        struct tcphdr *tcph = (struct tcphdr *)th;
 889                        tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
 890                                                         skb->len - iph->ihl*4,
 891                                                         IPPROTO_TCP, 0);
 892                }
 893                break;
 894        case IPPROTO_UDP:
 895                skb->csum_offset = offsetof(struct udphdr, check);
 896
 897                if (recalculate_partial_csum) {
 898                        struct udphdr *udph = (struct udphdr *)th;
 899                        udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
 900                                                         skb->len - iph->ihl*4,
 901                                                         IPPROTO_UDP, 0);
 902                }
 903                break;
 904        default:
 905                if (net_ratelimit())
 906                        printk(KERN_ERR "Attempting to checksum a non-"
 907                               "TCP/UDP packet, dropping a protocol"
 908                               " %d packet", iph->protocol);
 909                goto out;
 910        }
 911
 912        if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
 913                goto out;
 914
 915        err = 0;
 916
 917out:
 918        return err;
 919}
 920
 921static int handle_incoming_queue(struct net_device *dev,
 922                                 struct sk_buff_head *rxq)
 923{
 924        struct netfront_info *np = netdev_priv(dev);
 925        struct netfront_stats *stats = this_cpu_ptr(np->stats);
 926        int packets_dropped = 0;
 927        struct sk_buff *skb;
 928
 929        while ((skb = __skb_dequeue(rxq)) != NULL) {
 930                int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
 931
 932                __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
 933
 934                /* Ethernet work: Delayed to here as it peeks the header. */
 935                skb->protocol = eth_type_trans(skb, dev);
 936
 937                if (checksum_setup(dev, skb)) {
 938                        kfree_skb(skb);
 939                        packets_dropped++;
 940                        dev->stats.rx_errors++;
 941                        continue;
 942                }
 943
 944                u64_stats_update_begin(&stats->syncp);
 945                stats->rx_packets++;
 946                stats->rx_bytes += skb->len;
 947                u64_stats_update_end(&stats->syncp);
 948
 949                /* Pass it up. */
 950                netif_receive_skb(skb);
 951        }
 952
 953        return packets_dropped;
 954}
 955
 956static int xennet_poll(struct napi_struct *napi, int budget)
 957{
 958        struct netfront_info *np = container_of(napi, struct netfront_info, napi);
 959        struct net_device *dev = np->netdev;
 960        struct sk_buff *skb;
 961        struct netfront_rx_info rinfo;
 962        struct xen_netif_rx_response *rx = &rinfo.rx;
 963        struct xen_netif_extra_info *extras = rinfo.extras;
 964        RING_IDX i, rp;
 965        int work_done;
 966        struct sk_buff_head rxq;
 967        struct sk_buff_head errq;
 968        struct sk_buff_head tmpq;
 969        unsigned long flags;
 970        int err;
 971
 972        spin_lock(&np->rx_lock);
 973
 974        skb_queue_head_init(&rxq);
 975        skb_queue_head_init(&errq);
 976        skb_queue_head_init(&tmpq);
 977
 978        rp = np->rx.sring->rsp_prod;
 979        rmb(); /* Ensure we see queued responses up to 'rp'. */
 980
 981        i = np->rx.rsp_cons;
 982        work_done = 0;
 983        while ((i != rp) && (work_done < budget)) {
 984                memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
 985                memset(extras, 0, sizeof(rinfo.extras));
 986
 987                err = xennet_get_responses(np, &rinfo, rp, &tmpq);
 988
 989                if (unlikely(err)) {
 990err:
 991                        while ((skb = __skb_dequeue(&tmpq)))
 992                                __skb_queue_tail(&errq, skb);
 993                        dev->stats.rx_errors++;
 994                        i = np->rx.rsp_cons;
 995                        continue;
 996                }
 997
 998                skb = __skb_dequeue(&tmpq);
 999
1000                if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1001                        struct xen_netif_extra_info *gso;
1002                        gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1003
1004                        if (unlikely(xennet_set_skb_gso(skb, gso))) {
1005                                __skb_queue_head(&tmpq, skb);
1006                                np->rx.rsp_cons += skb_queue_len(&tmpq);
1007                                goto err;
1008                        }
1009                }
1010
1011                NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1012                if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1013                        NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1014
1015                skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1016                skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1017                skb->data_len = rx->status;
1018
1019                i = xennet_fill_frags(np, skb, &tmpq);
1020
1021                /*
1022                 * Truesize is the actual allocation size, even if the
1023                 * allocation is only partially used.
1024                 */
1025                skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags;
1026                skb->len += skb->data_len;
1027
1028                if (rx->flags & XEN_NETRXF_csum_blank)
1029                        skb->ip_summed = CHECKSUM_PARTIAL;
1030                else if (rx->flags & XEN_NETRXF_data_validated)
1031                        skb->ip_summed = CHECKSUM_UNNECESSARY;
1032
1033                __skb_queue_tail(&rxq, skb);
1034
1035                np->rx.rsp_cons = ++i;
1036                work_done++;
1037        }
1038
1039        __skb_queue_purge(&errq);
1040
1041        work_done -= handle_incoming_queue(dev, &rxq);
1042
1043        /* If we get a callback with very few responses, reduce fill target. */
1044        /* NB. Note exponential increase, linear decrease. */
1045        if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1046             ((3*np->rx_target) / 4)) &&
1047            (--np->rx_target < np->rx_min_target))
1048                np->rx_target = np->rx_min_target;
1049
1050        xennet_alloc_rx_buffers(dev);
1051
1052        if (work_done < budget) {
1053                int more_to_do = 0;
1054
1055                local_irq_save(flags);
1056
1057                RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1058                if (!more_to_do)
1059                        __napi_complete(napi);
1060
1061                local_irq_restore(flags);
1062        }
1063
1064        spin_unlock(&np->rx_lock);
1065
1066        return work_done;
1067}
1068
1069static int xennet_change_mtu(struct net_device *dev, int mtu)
1070{
1071        int max = xennet_can_sg(dev) ?
1072                XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1073
1074        if (mtu > max)
1075                return -EINVAL;
1076        dev->mtu = mtu;
1077        return 0;
1078}
1079
1080static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1081                                                    struct rtnl_link_stats64 *tot)
1082{
1083        struct netfront_info *np = netdev_priv(dev);
1084        int cpu;
1085
1086        for_each_possible_cpu(cpu) {
1087                struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1088                u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1089                unsigned int start;
1090
1091                do {
1092                        start = u64_stats_fetch_begin_bh(&stats->syncp);
1093
1094                        rx_packets = stats->rx_packets;
1095                        tx_packets = stats->tx_packets;
1096                        rx_bytes = stats->rx_bytes;
1097                        tx_bytes = stats->tx_bytes;
1098                } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
1099
1100                tot->rx_packets += rx_packets;
1101                tot->tx_packets += tx_packets;
1102                tot->rx_bytes   += rx_bytes;
1103                tot->tx_bytes   += tx_bytes;
1104        }
1105
1106        tot->rx_errors  = dev->stats.rx_errors;
1107        tot->tx_dropped = dev->stats.tx_dropped;
1108
1109        return tot;
1110}
1111
1112static void xennet_release_tx_bufs(struct netfront_info *np)
1113{
1114        struct sk_buff *skb;
1115        int i;
1116
1117        for (i = 0; i < NET_TX_RING_SIZE; i++) {
1118                /* Skip over entries which are actually freelist references */
1119                if (skb_entry_is_link(&np->tx_skbs[i]))
1120                        continue;
1121
1122                skb = np->tx_skbs[i].skb;
1123                gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
1124                                              GNTMAP_readonly);
1125                gnttab_release_grant_reference(&np->gref_tx_head,
1126                                               np->grant_tx_ref[i]);
1127                np->grant_tx_ref[i] = GRANT_INVALID_REF;
1128                add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1129                dev_kfree_skb_irq(skb);
1130        }
1131}
1132
1133static void xennet_release_rx_bufs(struct netfront_info *np)
1134{
1135        struct mmu_update      *mmu = np->rx_mmu;
1136        struct multicall_entry *mcl = np->rx_mcl;
1137        struct sk_buff_head free_list;
1138        struct sk_buff *skb;
1139        unsigned long mfn;
1140        int xfer = 0, noxfer = 0, unused = 0;
1141        int id, ref;
1142
1143        dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
1144                         __func__);
1145        return;
1146
1147        skb_queue_head_init(&free_list);
1148
1149        spin_lock_bh(&np->rx_lock);
1150
1151        for (id = 0; id < NET_RX_RING_SIZE; id++) {
1152                ref = np->grant_rx_ref[id];
1153                if (ref == GRANT_INVALID_REF) {
1154                        unused++;
1155                        continue;
1156                }
1157
1158                skb = np->rx_skbs[id];
1159                mfn = gnttab_end_foreign_transfer_ref(ref);
1160                gnttab_release_grant_reference(&np->gref_rx_head, ref);
1161                np->grant_rx_ref[id] = GRANT_INVALID_REF;
1162
1163                if (0 == mfn) {
1164                        skb_shinfo(skb)->nr_frags = 0;
1165                        dev_kfree_skb(skb);
1166                        noxfer++;
1167                        continue;
1168                }
1169
1170                if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1171                        /* Remap the page. */
1172                        const struct page *page =
1173                                skb_frag_page(&skb_shinfo(skb)->frags[0]);
1174                        unsigned long pfn = page_to_pfn(page);
1175                        void *vaddr = page_address(page);
1176
1177                        MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
1178                                                mfn_pte(mfn, PAGE_KERNEL),
1179                                                0);
1180                        mcl++;
1181                        mmu->ptr = ((u64)mfn << PAGE_SHIFT)
1182                                | MMU_MACHPHYS_UPDATE;
1183                        mmu->val = pfn;
1184                        mmu++;
1185
1186                        set_phys_to_machine(pfn, mfn);
1187                }
1188                __skb_queue_tail(&free_list, skb);
1189                xfer++;
1190        }
1191
1192        dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
1193                 __func__, xfer, noxfer, unused);
1194
1195        if (xfer) {
1196                if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1197                        /* Do all the remapping work and M2P updates. */
1198                        MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
1199                                         NULL, DOMID_SELF);
1200                        mcl++;
1201                        HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
1202                }
1203        }
1204
1205        __skb_queue_purge(&free_list);
1206
1207        spin_unlock_bh(&np->rx_lock);
1208}
1209
1210static void xennet_uninit(struct net_device *dev)
1211{
1212        struct netfront_info *np = netdev_priv(dev);
1213        xennet_release_tx_bufs(np);
1214        xennet_release_rx_bufs(np);
1215        gnttab_free_grant_references(np->gref_tx_head);
1216        gnttab_free_grant_references(np->gref_rx_head);
1217}
1218
1219static netdev_features_t xennet_fix_features(struct net_device *dev,
1220        netdev_features_t features)
1221{
1222        struct netfront_info *np = netdev_priv(dev);
1223        int val;
1224
1225        if (features & NETIF_F_SG) {
1226                if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1227                                 "%d", &val) < 0)
1228                        val = 0;
1229
1230                if (!val)
1231                        features &= ~NETIF_F_SG;
1232        }
1233
1234        if (features & NETIF_F_TSO) {
1235                if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1236                                 "feature-gso-tcpv4", "%d", &val) < 0)
1237                        val = 0;
1238
1239                if (!val)
1240                        features &= ~NETIF_F_TSO;
1241        }
1242
1243        return features;
1244}
1245
1246static int xennet_set_features(struct net_device *dev,
1247        netdev_features_t features)
1248{
1249        if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1250                netdev_info(dev, "Reducing MTU because no SG offload");
1251                dev->mtu = ETH_DATA_LEN;
1252        }
1253
1254        return 0;
1255}
1256
1257static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1258{
1259        struct net_device *dev = dev_id;
1260        struct netfront_info *np = netdev_priv(dev);
1261        unsigned long flags;
1262
1263        spin_lock_irqsave(&np->tx_lock, flags);
1264
1265        if (likely(netif_carrier_ok(dev))) {
1266                xennet_tx_buf_gc(dev);
1267                /* Under tx_lock: protects access to rx shared-ring indexes. */
1268                if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
1269                        napi_schedule(&np->napi);
1270        }
1271
1272        spin_unlock_irqrestore(&np->tx_lock, flags);
1273
1274        return IRQ_HANDLED;
1275}
1276
1277#ifdef CONFIG_NET_POLL_CONTROLLER
1278static void xennet_poll_controller(struct net_device *dev)
1279{
1280        xennet_interrupt(0, dev);
1281}
1282#endif
1283
1284static const struct net_device_ops xennet_netdev_ops = {
1285        .ndo_open            = xennet_open,
1286        .ndo_uninit          = xennet_uninit,
1287        .ndo_stop            = xennet_close,
1288        .ndo_start_xmit      = xennet_start_xmit,
1289        .ndo_change_mtu      = xennet_change_mtu,
1290        .ndo_get_stats64     = xennet_get_stats64,
1291        .ndo_set_mac_address = eth_mac_addr,
1292        .ndo_validate_addr   = eth_validate_addr,
1293        .ndo_fix_features    = xennet_fix_features,
1294        .ndo_set_features    = xennet_set_features,
1295#ifdef CONFIG_NET_POLL_CONTROLLER
1296        .ndo_poll_controller = xennet_poll_controller,
1297#endif
1298};
1299
1300static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1301{
1302        int i, err;
1303        struct net_device *netdev;
1304        struct netfront_info *np;
1305
1306        netdev = alloc_etherdev(sizeof(struct netfront_info));
1307        if (!netdev)
1308                return ERR_PTR(-ENOMEM);
1309
1310        np                   = netdev_priv(netdev);
1311        np->xbdev            = dev;
1312
1313        spin_lock_init(&np->tx_lock);
1314        spin_lock_init(&np->rx_lock);
1315
1316        skb_queue_head_init(&np->rx_batch);
1317        np->rx_target     = RX_DFL_MIN_TARGET;
1318        np->rx_min_target = RX_DFL_MIN_TARGET;
1319        np->rx_max_target = RX_MAX_TARGET;
1320
1321        init_timer(&np->rx_refill_timer);
1322        np->rx_refill_timer.data = (unsigned long)netdev;
1323        np->rx_refill_timer.function = rx_refill_timeout;
1324
1325        err = -ENOMEM;
1326        np->stats = alloc_percpu(struct netfront_stats);
1327        if (np->stats == NULL)
1328                goto exit;
1329
1330        /* Initialise tx_skbs as a free chain containing every entry. */
1331        np->tx_skb_freelist = 0;
1332        for (i = 0; i < NET_TX_RING_SIZE; i++) {
1333                skb_entry_set_link(&np->tx_skbs[i], i+1);
1334                np->grant_tx_ref[i] = GRANT_INVALID_REF;
1335        }
1336
1337        /* Clear out rx_skbs */
1338        for (i = 0; i < NET_RX_RING_SIZE; i++) {
1339                np->rx_skbs[i] = NULL;
1340                np->grant_rx_ref[i] = GRANT_INVALID_REF;
1341        }
1342
1343        /* A grant for every tx ring slot */
1344        if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1345                                          &np->gref_tx_head) < 0) {
1346                printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
1347                err = -ENOMEM;
1348                goto exit_free_stats;
1349        }
1350        /* A grant for every rx ring slot */
1351        if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1352                                          &np->gref_rx_head) < 0) {
1353                printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
1354                err = -ENOMEM;
1355                goto exit_free_tx;
1356        }
1357
1358        netdev->netdev_ops      = &xennet_netdev_ops;
1359
1360        netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1361        netdev->features        = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1362                                  NETIF_F_GSO_ROBUST;
1363        netdev->hw_features     = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
1364
1365        /*
1366         * Assume that all hw features are available for now. This set
1367         * will be adjusted by the call to netdev_update_features() in
1368         * xennet_connect() which is the earliest point where we can
1369         * negotiate with the backend regarding supported features.
1370         */
1371        netdev->features |= netdev->hw_features;
1372
1373        SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1374        SET_NETDEV_DEV(netdev, &dev->dev);
1375
1376        netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1377
1378        np->netdev = netdev;
1379
1380        netif_carrier_off(netdev);
1381
1382        return netdev;
1383
1384 exit_free_tx:
1385        gnttab_free_grant_references(np->gref_tx_head);
1386 exit_free_stats:
1387        free_percpu(np->stats);
1388 exit:
1389        free_netdev(netdev);
1390        return ERR_PTR(err);
1391}
1392
1393/**
1394 * Entry point to this code when a new device is created.  Allocate the basic
1395 * structures and the ring buffers for communication with the backend, and
1396 * inform the backend of the appropriate details for those.
1397 */
1398static int netfront_probe(struct xenbus_device *dev,
1399                          const struct xenbus_device_id *id)
1400{
1401        int err;
1402        struct net_device *netdev;
1403        struct netfront_info *info;
1404
1405        netdev = xennet_create_dev(dev);
1406        if (IS_ERR(netdev)) {
1407                err = PTR_ERR(netdev);
1408                xenbus_dev_fatal(dev, err, "creating netdev");
1409                return err;
1410        }
1411
1412        info = netdev_priv(netdev);
1413        dev_set_drvdata(&dev->dev, info);
1414
1415        err = register_netdev(info->netdev);
1416        if (err) {
1417                printk(KERN_WARNING "%s: register_netdev err=%d\n",
1418                       __func__, err);
1419                goto fail;
1420        }
1421
1422        err = xennet_sysfs_addif(info->netdev);
1423        if (err) {
1424                unregister_netdev(info->netdev);
1425                printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
1426                       __func__, err);
1427                goto fail;
1428        }
1429
1430        return 0;
1431
1432 fail:
1433        free_netdev(netdev);
1434        dev_set_drvdata(&dev->dev, NULL);
1435        return err;
1436}
1437
1438static void xennet_end_access(int ref, void *page)
1439{
1440        /* This frees the page as a side-effect */
1441        if (ref != GRANT_INVALID_REF)
1442                gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1443}
1444
1445static void xennet_disconnect_backend(struct netfront_info *info)
1446{
1447        /* Stop old i/f to prevent errors whilst we rebuild the state. */
1448        spin_lock_bh(&info->rx_lock);
1449        spin_lock_irq(&info->tx_lock);
1450        netif_carrier_off(info->netdev);
1451        spin_unlock_irq(&info->tx_lock);
1452        spin_unlock_bh(&info->rx_lock);
1453
1454        if (info->netdev->irq)
1455                unbind_from_irqhandler(info->netdev->irq, info->netdev);
1456        info->evtchn = info->netdev->irq = 0;
1457
1458        /* End access and free the pages */
1459        xennet_end_access(info->tx_ring_ref, info->tx.sring);
1460        xennet_end_access(info->rx_ring_ref, info->rx.sring);
1461
1462        info->tx_ring_ref = GRANT_INVALID_REF;
1463        info->rx_ring_ref = GRANT_INVALID_REF;
1464        info->tx.sring = NULL;
1465        info->rx.sring = NULL;
1466}
1467
1468/**
1469 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1470 * driver restart.  We tear down our netif structure and recreate it, but
1471 * leave the device-layer structures intact so that this is transparent to the
1472 * rest of the kernel.
1473 */
1474static int netfront_resume(struct xenbus_device *dev)
1475{
1476        struct netfront_info *info = dev_get_drvdata(&dev->dev);
1477
1478        dev_dbg(&dev->dev, "%s\n", dev->nodename);
1479
1480        xennet_disconnect_backend(info);
1481        return 0;
1482}
1483
1484static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1485{
1486        char *s, *e, *macstr;
1487        int i;
1488
1489        macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1490        if (IS_ERR(macstr))
1491                return PTR_ERR(macstr);
1492
1493        for (i = 0; i < ETH_ALEN; i++) {
1494                mac[i] = simple_strtoul(s, &e, 16);
1495                if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1496                        kfree(macstr);
1497                        return -ENOENT;
1498                }
1499                s = e+1;
1500        }
1501
1502        kfree(macstr);
1503        return 0;
1504}
1505
1506static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1507{
1508        struct xen_netif_tx_sring *txs;
1509        struct xen_netif_rx_sring *rxs;
1510        int err;
1511        struct net_device *netdev = info->netdev;
1512
1513        info->tx_ring_ref = GRANT_INVALID_REF;
1514        info->rx_ring_ref = GRANT_INVALID_REF;
1515        info->rx.sring = NULL;
1516        info->tx.sring = NULL;
1517        netdev->irq = 0;
1518
1519        err = xen_net_read_mac(dev, netdev->dev_addr);
1520        if (err) {
1521                xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1522                goto fail;
1523        }
1524
1525        txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1526        if (!txs) {
1527                err = -ENOMEM;
1528                xenbus_dev_fatal(dev, err, "allocating tx ring page");
1529                goto fail;
1530        }
1531        SHARED_RING_INIT(txs);
1532        FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1533
1534        err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1535        if (err < 0) {
1536                free_page((unsigned long)txs);
1537                goto fail;
1538        }
1539
1540        info->tx_ring_ref = err;
1541        rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1542        if (!rxs) {
1543                err = -ENOMEM;
1544                xenbus_dev_fatal(dev, err, "allocating rx ring page");
1545                goto fail;
1546        }
1547        SHARED_RING_INIT(rxs);
1548        FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1549
1550        err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1551        if (err < 0) {
1552                free_page((unsigned long)rxs);
1553                goto fail;
1554        }
1555        info->rx_ring_ref = err;
1556
1557        err = xenbus_alloc_evtchn(dev, &info->evtchn);
1558        if (err)
1559                goto fail;
1560
1561        err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
1562                                        0, netdev->name, netdev);
1563        if (err < 0)
1564                goto fail;
1565        netdev->irq = err;
1566        return 0;
1567
1568 fail:
1569        return err;
1570}
1571
1572/* Common code used when first setting up, and when resuming. */
1573static int talk_to_netback(struct xenbus_device *dev,
1574                           struct netfront_info *info)
1575{
1576        const char *message;
1577        struct xenbus_transaction xbt;
1578        int err;
1579
1580        /* Create shared ring, alloc event channel. */
1581        err = setup_netfront(dev, info);
1582        if (err)
1583                goto out;
1584
1585again:
1586        err = xenbus_transaction_start(&xbt);
1587        if (err) {
1588                xenbus_dev_fatal(dev, err, "starting transaction");
1589                goto destroy_ring;
1590        }
1591
1592        err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1593                            info->tx_ring_ref);
1594        if (err) {
1595                message = "writing tx ring-ref";
1596                goto abort_transaction;
1597        }
1598        err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1599                            info->rx_ring_ref);
1600        if (err) {
1601                message = "writing rx ring-ref";
1602                goto abort_transaction;
1603        }
1604        err = xenbus_printf(xbt, dev->nodename,
1605                            "event-channel", "%u", info->evtchn);
1606        if (err) {
1607                message = "writing event-channel";
1608                goto abort_transaction;
1609        }
1610
1611        err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1612                            1);
1613        if (err) {
1614                message = "writing request-rx-copy";
1615                goto abort_transaction;
1616        }
1617
1618        err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1619        if (err) {
1620                message = "writing feature-rx-notify";
1621                goto abort_transaction;
1622        }
1623
1624        err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1625        if (err) {
1626                message = "writing feature-sg";
1627                goto abort_transaction;
1628        }
1629
1630        err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1631        if (err) {
1632                message = "writing feature-gso-tcpv4";
1633                goto abort_transaction;
1634        }
1635
1636        err = xenbus_transaction_end(xbt, 0);
1637        if (err) {
1638                if (err == -EAGAIN)
1639                        goto again;
1640                xenbus_dev_fatal(dev, err, "completing transaction");
1641                goto destroy_ring;
1642        }
1643
1644        return 0;
1645
1646 abort_transaction:
1647        xenbus_transaction_end(xbt, 1);
1648        xenbus_dev_fatal(dev, err, "%s", message);
1649 destroy_ring:
1650        xennet_disconnect_backend(info);
1651 out:
1652        return err;
1653}
1654
1655static int xennet_connect(struct net_device *dev)
1656{
1657        struct netfront_info *np = netdev_priv(dev);
1658        int i, requeue_idx, err;
1659        struct sk_buff *skb;
1660        grant_ref_t ref;
1661        struct xen_netif_rx_request *req;
1662        unsigned int feature_rx_copy;
1663
1664        err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1665                           "feature-rx-copy", "%u", &feature_rx_copy);
1666        if (err != 1)
1667                feature_rx_copy = 0;
1668
1669        if (!feature_rx_copy) {
1670                dev_info(&dev->dev,
1671                         "backend does not support copying receive path\n");
1672                return -ENODEV;
1673        }
1674
1675        err = talk_to_netback(np->xbdev, np);
1676        if (err)
1677                return err;
1678
1679        rtnl_lock();
1680        netdev_update_features(dev);
1681        rtnl_unlock();
1682
1683        spin_lock_bh(&np->rx_lock);
1684        spin_lock_irq(&np->tx_lock);
1685
1686        /* Step 1: Discard all pending TX packet fragments. */
1687        xennet_release_tx_bufs(np);
1688
1689        /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1690        for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1691                skb_frag_t *frag;
1692                const struct page *page;
1693                if (!np->rx_skbs[i])
1694                        continue;
1695
1696                skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1697                ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1698                req = RING_GET_REQUEST(&np->rx, requeue_idx);
1699
1700                frag = &skb_shinfo(skb)->frags[0];
1701                page = skb_frag_page(frag);
1702                gnttab_grant_foreign_access_ref(
1703                        ref, np->xbdev->otherend_id,
1704                        pfn_to_mfn(page_to_pfn(page)),
1705                        0);
1706                req->gref = ref;
1707                req->id   = requeue_idx;
1708
1709                requeue_idx++;
1710        }
1711
1712        np->rx.req_prod_pvt = requeue_idx;
1713
1714        /*
1715         * Step 3: All public and private state should now be sane.  Get
1716         * ready to start sending and receiving packets and give the driver
1717         * domain a kick because we've probably just requeued some
1718         * packets.
1719         */
1720        netif_carrier_on(np->netdev);
1721        notify_remote_via_irq(np->netdev->irq);
1722        xennet_tx_buf_gc(dev);
1723        xennet_alloc_rx_buffers(dev);
1724
1725        spin_unlock_irq(&np->tx_lock);
1726        spin_unlock_bh(&np->rx_lock);
1727
1728        return 0;
1729}
1730
1731/**
1732 * Callback received when the backend's state changes.
1733 */
1734static void netback_changed(struct xenbus_device *dev,
1735                            enum xenbus_state backend_state)
1736{
1737        struct netfront_info *np = dev_get_drvdata(&dev->dev);
1738        struct net_device *netdev = np->netdev;
1739
1740        dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1741
1742        switch (backend_state) {
1743        case XenbusStateInitialising:
1744        case XenbusStateInitialised:
1745        case XenbusStateReconfiguring:
1746        case XenbusStateReconfigured:
1747        case XenbusStateUnknown:
1748        case XenbusStateClosed:
1749                break;
1750
1751        case XenbusStateInitWait:
1752                if (dev->state != XenbusStateInitialising)
1753                        break;
1754                if (xennet_connect(netdev) != 0)
1755                        break;
1756                xenbus_switch_state(dev, XenbusStateConnected);
1757                break;
1758
1759        case XenbusStateConnected:
1760                netdev_notify_peers(netdev);
1761                break;
1762
1763        case XenbusStateClosing:
1764                xenbus_frontend_closed(dev);
1765                break;
1766        }
1767}
1768
1769static const struct xennet_stat {
1770        char name[ETH_GSTRING_LEN];
1771        u16 offset;
1772} xennet_stats[] = {
1773        {
1774                "rx_gso_checksum_fixup",
1775                offsetof(struct netfront_info, rx_gso_checksum_fixup)
1776        },
1777};
1778
1779static int xennet_get_sset_count(struct net_device *dev, int string_set)
1780{
1781        switch (string_set) {
1782        case ETH_SS_STATS:
1783                return ARRAY_SIZE(xennet_stats);
1784        default:
1785                return -EINVAL;
1786        }
1787}
1788
1789static void xennet_get_ethtool_stats(struct net_device *dev,
1790                                     struct ethtool_stats *stats, u64 * data)
1791{
1792        void *np = netdev_priv(dev);
1793        int i;
1794
1795        for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1796                data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1797}
1798
1799static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1800{
1801        int i;
1802
1803        switch (stringset) {
1804        case ETH_SS_STATS:
1805                for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1806                        memcpy(data + i * ETH_GSTRING_LEN,
1807                               xennet_stats[i].name, ETH_GSTRING_LEN);
1808                break;
1809        }
1810}
1811
1812static const struct ethtool_ops xennet_ethtool_ops =
1813{
1814        .get_link = ethtool_op_get_link,
1815
1816        .get_sset_count = xennet_get_sset_count,
1817        .get_ethtool_stats = xennet_get_ethtool_stats,
1818        .get_strings = xennet_get_strings,
1819};
1820
1821#ifdef CONFIG_SYSFS
1822static ssize_t show_rxbuf_min(struct device *dev,
1823                              struct device_attribute *attr, char *buf)
1824{
1825        struct net_device *netdev = to_net_dev(dev);
1826        struct netfront_info *info = netdev_priv(netdev);
1827
1828        return sprintf(buf, "%u\n", info->rx_min_target);
1829}
1830
1831static ssize_t store_rxbuf_min(struct device *dev,
1832                               struct device_attribute *attr,
1833                               const char *buf, size_t len)
1834{
1835        struct net_device *netdev = to_net_dev(dev);
1836        struct netfront_info *np = netdev_priv(netdev);
1837        char *endp;
1838        unsigned long target;
1839
1840        if (!capable(CAP_NET_ADMIN))
1841                return -EPERM;
1842
1843        target = simple_strtoul(buf, &endp, 0);
1844        if (endp == buf)
1845                return -EBADMSG;
1846
1847        if (target < RX_MIN_TARGET)
1848                target = RX_MIN_TARGET;
1849        if (target > RX_MAX_TARGET)
1850                target = RX_MAX_TARGET;
1851
1852        spin_lock_bh(&np->rx_lock);
1853        if (target > np->rx_max_target)
1854                np->rx_max_target = target;
1855        np->rx_min_target = target;
1856        if (target > np->rx_target)
1857                np->rx_target = target;
1858
1859        xennet_alloc_rx_buffers(netdev);
1860
1861        spin_unlock_bh(&np->rx_lock);
1862        return len;
1863}
1864
1865static ssize_t show_rxbuf_max(struct device *dev,
1866                              struct device_attribute *attr, char *buf)
1867{
1868        struct net_device *netdev = to_net_dev(dev);
1869        struct netfront_info *info = netdev_priv(netdev);
1870
1871        return sprintf(buf, "%u\n", info->rx_max_target);
1872}
1873
1874static ssize_t store_rxbuf_max(struct device *dev,
1875                               struct device_attribute *attr,
1876                               const char *buf, size_t len)
1877{
1878        struct net_device *netdev = to_net_dev(dev);
1879        struct netfront_info *np = netdev_priv(netdev);
1880        char *endp;
1881        unsigned long target;
1882
1883        if (!capable(CAP_NET_ADMIN))
1884                return -EPERM;
1885
1886        target = simple_strtoul(buf, &endp, 0);
1887        if (endp == buf)
1888                return -EBADMSG;
1889
1890        if (target < RX_MIN_TARGET)
1891                target = RX_MIN_TARGET;
1892        if (target > RX_MAX_TARGET)
1893                target = RX_MAX_TARGET;
1894
1895        spin_lock_bh(&np->rx_lock);
1896        if (target < np->rx_min_target)
1897                np->rx_min_target = target;
1898        np->rx_max_target = target;
1899        if (target < np->rx_target)
1900                np->rx_target = target;
1901
1902        xennet_alloc_rx_buffers(netdev);
1903
1904        spin_unlock_bh(&np->rx_lock);
1905        return len;
1906}
1907
1908static ssize_t show_rxbuf_cur(struct device *dev,
1909                              struct device_attribute *attr, char *buf)
1910{
1911        struct net_device *netdev = to_net_dev(dev);
1912        struct netfront_info *info = netdev_priv(netdev);
1913
1914        return sprintf(buf, "%u\n", info->rx_target);
1915}
1916
1917static struct device_attribute xennet_attrs[] = {
1918        __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
1919        __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
1920        __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
1921};
1922
1923static int xennet_sysfs_addif(struct net_device *netdev)
1924{
1925        int i;
1926        int err;
1927
1928        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
1929                err = device_create_file(&netdev->dev,
1930                                           &xennet_attrs[i]);
1931                if (err)
1932                        goto fail;
1933        }
1934        return 0;
1935
1936 fail:
1937        while (--i >= 0)
1938                device_remove_file(&netdev->dev, &xennet_attrs[i]);
1939        return err;
1940}
1941
1942static void xennet_sysfs_delif(struct net_device *netdev)
1943{
1944        int i;
1945
1946        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
1947                device_remove_file(&netdev->dev, &xennet_attrs[i]);
1948}
1949
1950#endif /* CONFIG_SYSFS */
1951
1952static const struct xenbus_device_id netfront_ids[] = {
1953        { "vif" },
1954        { "" }
1955};
1956
1957
1958static int xennet_remove(struct xenbus_device *dev)
1959{
1960        struct netfront_info *info = dev_get_drvdata(&dev->dev);
1961
1962        dev_dbg(&dev->dev, "%s\n", dev->nodename);
1963
1964        xennet_disconnect_backend(info);
1965
1966        xennet_sysfs_delif(info->netdev);
1967
1968        unregister_netdev(info->netdev);
1969
1970        del_timer_sync(&info->rx_refill_timer);
1971
1972        free_percpu(info->stats);
1973
1974        free_netdev(info->netdev);
1975
1976        return 0;
1977}
1978
1979static DEFINE_XENBUS_DRIVER(netfront, ,
1980        .probe = netfront_probe,
1981        .remove = xennet_remove,
1982        .resume = netfront_resume,
1983        .otherend_changed = netback_changed,
1984);
1985
1986static int __init netif_init(void)
1987{
1988        if (!xen_domain())
1989                return -ENODEV;
1990
1991        if (xen_hvm_domain() && !xen_platform_pci_unplug)
1992                return -ENODEV;
1993
1994        printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
1995
1996        return xenbus_register_frontend(&netfront_driver);
1997}
1998module_init(netif_init);
1999
2000
2001static void __exit netif_exit(void)
2002{
2003        xenbus_unregister_driver(&netfront_driver);
2004}
2005module_exit(netif_exit);
2006
2007MODULE_DESCRIPTION("Xen virtual network device frontend");
2008MODULE_LICENSE("GPL");
2009MODULE_ALIAS("xen:vif");
2010MODULE_ALIAS("xennet");
2011
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