drivers/block/aoe/aoecmd.c

   1 /* Copyright (c) 2006 Coraid, Inc.  See COPYING for GPL terms. */
   2 /*
   3  * aoecmd.c
   4  * Filesystem request handling methods
   5  */
   6
   7 #include <linux/hdreg.h>
   8 #include <linux/blkdev.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/genhd.h>
  12 #include <asm/unaligned.h>
  13 #include "aoe.h"
  14
  15 #define TIMERTICK (HZ / 10)
  16 #define MINTIMER (2 * TIMERTICK)
  17 #define MAXTIMER (HZ << 1)
  18
  19 static int aoe_deadsecs = 60 * 3;
  20 module_param(aoe_deadsecs, int, 0644);
  21 MODULE_PARM_DESC(aoe_deadsecs, "After aoe_deadsecs seconds, give up and fail dev.");
  22
  23 struct sk_buff *
  24 new_skb(ulong len)
  25 {
  26         struct sk_buff *skb;
  27
  28         skb = alloc_skb(len, GFP_ATOMIC);
  29         if (skb) {
  30                 skb->nh.raw = skb->mac.raw = skb->data;
  31                 skb->protocol = __constant_htons(ETH_P_AOE);
  32                 skb->priority = 0;
  33                 skb_put(skb, len);
  34                 memset(skb->head, 0, len);
  35                 skb->next = skb->prev = NULL;
  36
  37                 /* tell the network layer not to perform IP checksums
  38                  * or to get the NIC to do it
  39                  */
  40                 skb->ip_summed = CHECKSUM_NONE;
  41         }
  42         return skb;
  43 }
  44
  45 static struct frame *
  46 getframe(struct aoedev *d, int tag)
  47 {
  48         struct frame *f, *e;
  49
  50         f = d->frames;
  51         e = f + d->nframes;
  52         for (; f<e; f++)
  53                 if (f->tag == tag)
  54                         return f;
  55         return NULL;
  56 }
  57
  58 /*
  59  * Leave the top bit clear so we have tagspace for userland.
  60  * The bottom 16 bits are the xmit tick for rexmit/rttavg processing.
  61  * This driver reserves tag -1 to mean "unused frame."
  62  */
  63 static int
  64 newtag(struct aoedev *d)
  65 {
  66         register ulong n;
  67
  68         n = jiffies & 0xffff;
  69         return n |= (++d->lasttag & 0x7fff) << 16;
  70 }
  71
  72 static int
  73 aoehdr_atainit(struct aoedev *d, struct aoe_hdr *h)
  74 {
  75         u32 host_tag = newtag(d);
  76
  77         memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
  78         memcpy(h->dst, d->addr, sizeof h->dst);
  79         h->type = __constant_cpu_to_be16(ETH_P_AOE);
  80         h->verfl = AOE_HVER;
  81         h->major = cpu_to_be16(d->aoemajor);
  82         h->minor = d->aoeminor;
  83         h->cmd = AOECMD_ATA;
  84         h->tag = cpu_to_be32(host_tag);
  85
  86         return host_tag;
  87 }
  88
  89 static inline void
  90 put_lba(struct aoe_atahdr *ah, sector_t lba)
  91 {
  92         ah->lba0 = lba;
  93         ah->lba1 = lba >>= 8;
  94         ah->lba2 = lba >>= 8;
  95         ah->lba3 = lba >>= 8;
  96         ah->lba4 = lba >>= 8;
  97         ah->lba5 = lba >>= 8;
  98 }
  99
 100 static void
 101 aoecmd_ata_rw(struct aoedev *d, struct frame *f)
 102 {
 103         struct aoe_hdr *h;
 104         struct aoe_atahdr *ah;
 105         struct buf *buf;
 106         struct sk_buff *skb;
 107         ulong bcnt;
 108         register sector_t sector;
 109         char writebit, extbit;
 110
 111         writebit = 0x10;
 112         extbit = 0x4;
 113
 114         buf = d->inprocess;
 115
 116         sector = buf->sector;
 117         bcnt = buf->bv_resid;
 118         if (bcnt > d->maxbcnt)
 119                 bcnt = d->maxbcnt;
 120
 121         /* initialize the headers & frame */
 122         skb = f->skb;
 123         h = (struct aoe_hdr *) skb->mac.raw;
 124         ah = (struct aoe_atahdr *) (h+1);
 125         skb->len = sizeof *h + sizeof *ah;
 126         memset(h, 0, ETH_ZLEN);
 127         f->tag = aoehdr_atainit(d, h);
 128         f->waited = 0;
 129         f->buf = buf;
 130         f->bufaddr = buf->bufaddr;
 131         f->bcnt = bcnt;
 132         f->lba = sector;
 133
 134         /* set up ata header */
 135         ah->scnt = bcnt >> 9;
 136         put_lba(ah, sector);
 137         if (d->flags & DEVFL_EXT) {
 138                 ah->aflags |= AOEAFL_EXT;
 139         } else {
 140                 extbit = 0;
 141                 ah->lba3 &= 0x0f;
 142                 ah->lba3 |= 0xe0;       /* LBA bit + obsolete 0xa0 */
 143         }
 144
 145         if (bio_data_dir(buf->bio) == WRITE) {
 146                 skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),
 147                         offset_in_page(f->bufaddr), bcnt);
 148                 ah->aflags |= AOEAFL_WRITE;
 149                 skb->len += bcnt;
 150                 skb->data_len = bcnt;
 151         } else {
 152                 skb->len = ETH_ZLEN;
 153                 writebit = 0;
 154         }
 155
 156         ah->cmdstat = WIN_READ | writebit | extbit;
 157
 158         /* mark all tracking fields and load out */
 159         buf->nframesout += 1;
 160         buf->bufaddr += bcnt;
 161         buf->bv_resid -= bcnt;
 162 /* printk(KERN_DEBUG "aoe: bv_resid=%ld\n", buf->bv_resid); */
 163         buf->resid -= bcnt;
 164         buf->sector += bcnt >> 9;
 165         if (buf->resid == 0) {
 166                 d->inprocess = NULL;
 167         } else if (buf->bv_resid == 0) {
 168                 buf->bv++;
 169                 WARN_ON(buf->bv->bv_len == 0);
 170                 buf->bv_resid = buf->bv->bv_len;
 171                 buf->bufaddr = page_address(buf->bv->bv_page) + buf->bv->bv_offset;
 172         }
 173
 174         skb->dev = d->ifp;
 175         skb = skb_clone(skb, GFP_ATOMIC);
 176         if (skb == NULL)
 177                 return;
 178         if (d->sendq_hd)
 179                 d->sendq_tl->next = skb;
 180         else
 181                 d->sendq_hd = skb;
 182         d->sendq_tl = skb;
 183 }
 184
 185 /* some callers cannot sleep, and they can call this function,
 186  * transmitting the packets later, when interrupts are on
 187  */
 188 static struct sk_buff *
 189 aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
 190 {
 191         struct aoe_hdr *h;
 192         struct aoe_cfghdr *ch;
 193         struct sk_buff *skb, *sl, *sl_tail;
 194         struct net_device *ifp;
 195
 196         sl = sl_tail = NULL;
 197
 198         read_lock(&dev_base_lock);
 199         for (ifp = dev_base; ifp; dev_put(ifp), ifp = ifp->next) {
 200                 dev_hold(ifp);
 201                 if (!is_aoe_netif(ifp))
 202                         continue;
 203
 204                 skb = new_skb(sizeof *h + sizeof *ch);
 205                 if (skb == NULL) {
 206                         printk(KERN_INFO "aoe: skb alloc failure\n");
 207                         continue;
 208                 }
 209                 skb->dev = ifp;
 210                 if (sl_tail == NULL)
 211                         sl_tail = skb;
 212                 h = (struct aoe_hdr *) skb->mac.raw;
 213                 memset(h, 0, sizeof *h + sizeof *ch);
 214
 215                 memset(h->dst, 0xff, sizeof h->dst);
 216                 memcpy(h->src, ifp->dev_addr, sizeof h->src);
 217                 h->type = __constant_cpu_to_be16(ETH_P_AOE);
 218                 h->verfl = AOE_HVER;
 219                 h->major = cpu_to_be16(aoemajor);
 220                 h->minor = aoeminor;
 221                 h->cmd = AOECMD_CFG;
 222
 223                 skb->next = sl;
 224                 sl = skb;
 225         }
 226         read_unlock(&dev_base_lock);
 227
 228         if (tail != NULL)
 229                 *tail = sl_tail;
 230         return sl;
 231 }
 232
 233 static struct frame *
 234 freeframe(struct aoedev *d)
 235 {
 236         struct frame *f, *e;
 237         int n = 0;
 238
 239         f = d->frames;
 240         e = f + d->nframes;
 241         for (; f<e; f++) {
 242                 if (f->tag != FREETAG)
 243                         continue;
 244                 if (atomic_read(&skb_shinfo(f->skb)->dataref) == 1) {
 245                         skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;
 246                         return f;
 247                 }
 248                 n++;
 249         }
 250         if (n == d->nframes)    /* wait for network layer */
 251                 d->flags |= DEVFL_KICKME;
 252
 253         return NULL;
 254 }
 255
 256 /* enters with d->lock held */
 257 void
 258 aoecmd_work(struct aoedev *d)
 259 {
 260         struct frame *f;
 261         struct buf *buf;
 262
 263         if (d->flags & DEVFL_PAUSE) {
 264                 if (!aoedev_isbusy(d))
 265                         d->sendq_hd = aoecmd_cfg_pkts(d->aoemajor,
 266                                                 d->aoeminor, &d->sendq_tl);
 267                 return;
 268         }
 269
 270 loop:
 271         f = freeframe(d);
 272         if (f == NULL)
 273                 return;
 274         if (d->inprocess == NULL) {
 275                 if (list_empty(&d->bufq))
 276                         return;
 277                 buf = container_of(d->bufq.next, struct buf, bufs);
 278                 list_del(d->bufq.next);
 279 /*printk(KERN_DEBUG "aoe: bi_size=%ld\n", buf->bio->bi_size); */
 280                 d->inprocess = buf;
 281         }
 282         aoecmd_ata_rw(d, f);
 283         goto loop;
 284 }
 285
 286 static void
 287 rexmit(struct aoedev *d, struct frame *f)
 288 {
 289         struct sk_buff *skb;
 290         struct aoe_hdr *h;
 291         struct aoe_atahdr *ah;
 292         char buf[128];
 293         u32 n;
 294
 295         n = newtag(d);
 296
 297         snprintf(buf, sizeof buf,
 298                 "%15s e%ld.%ld oldtag=%08x@%08lx newtag=%08x\n",
 299                 "retransmit",
 300                 d->aoemajor, d->aoeminor, f->tag, jiffies, n);
 301         aoechr_error(buf);
 302
 303         skb = f->skb;
 304         h = (struct aoe_hdr *) skb->mac.raw;
 305         ah = (struct aoe_atahdr *) (h+1);
 306         f->tag = n;
 307         h->tag = cpu_to_be32(n);
 308         memcpy(h->dst, d->addr, sizeof h->dst);
 309         memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
 310
 311         n = DEFAULTBCNT / 512;
 312         if (ah->scnt > n) {
 313                 ah->scnt = n;
 314                 if (ah->aflags & AOEAFL_WRITE) {
 315                         skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),
 316                                 offset_in_page(f->bufaddr), DEFAULTBCNT);
 317                         skb->len = sizeof *h + sizeof *ah + DEFAULTBCNT;
 318                         skb->data_len = DEFAULTBCNT;
 319                 }
 320                 if (++d->lostjumbo > (d->nframes << 1))
 321                 if (d->maxbcnt != DEFAULTBCNT) {
 322                         printk(KERN_INFO "aoe: e%ld.%ld: too many lost jumbo on %s - using 1KB frames.\n",
 323                                 d->aoemajor, d->aoeminor, d->ifp->name);
 324                         d->maxbcnt = DEFAULTBCNT;
 325                         d->flags |= DEVFL_MAXBCNT;
 326                 }
 327         }
 328
 329         skb->dev = d->ifp;
 330         skb = skb_clone(skb, GFP_ATOMIC);
 331         if (skb == NULL)
 332                 return;
 333         if (d->sendq_hd)
 334                 d->sendq_tl->next = skb;
 335         else
 336                 d->sendq_hd = skb;
 337         d->sendq_tl = skb;
 338 }
 339
 340 static int
 341 tsince(int tag)
 342 {
 343         int n;
 344
 345         n = jiffies & 0xffff;
 346         n -= tag & 0xffff;
 347         if (n < 0)
 348                 n += 1<<16;
 349         return n;
 350 }
 351
 352 static void
 353 rexmit_timer(ulong vp)
 354 {
 355         struct aoedev *d;
 356         struct frame *f, *e;
 357         struct sk_buff *sl;
 358         register long timeout;
 359         ulong flags, n;
 360
 361         d = (struct aoedev *) vp;
 362         sl = NULL;
 363
 364         /* timeout is always ~150% of the moving average */
 365         timeout = d->rttavg;
 366         timeout += timeout >> 1;
 367
 368         spin_lock_irqsave(&d->lock, flags);
 369
 370         if (d->flags & DEVFL_TKILL) {
 371                 spin_unlock_irqrestore(&d->lock, flags);
 372                 return;
 373         }
 374         f = d->frames;
 375         e = f + d->nframes;
 376         for (; f<e; f++) {
 377                 if (f->tag != FREETAG && tsince(f->tag) >= timeout) {
 378                         n = f->waited += timeout;
 379                         n /= HZ;
 380                         if (n > aoe_deadsecs) { /* waited too long for response */
 381                                 aoedev_downdev(d);
 382                                 break;
 383                         }
 384                         rexmit(d, f);
 385                 }
 386         }
 387         if (d->flags & DEVFL_KICKME) {
 388                 d->flags &= ~DEVFL_KICKME;
 389                 aoecmd_work(d);
 390         }
 391
 392         sl = d->sendq_hd;
 393         d->sendq_hd = d->sendq_tl = NULL;
 394         if (sl) {
 395                 n = d->rttavg <<= 1;
 396                 if (n > MAXTIMER)
 397                         d->rttavg = MAXTIMER;
 398         }
 399
 400         d->timer.expires = jiffies + TIMERTICK;
 401         add_timer(&d->timer);
 402
 403         spin_unlock_irqrestore(&d->lock, flags);
 404
 405         aoenet_xmit(sl);
 406 }
 407
 408 /* this function performs work that has been deferred until sleeping is OK
 409  */
 410 void
 411 aoecmd_sleepwork(struct work_struct *work)
 412 {
 413         struct aoedev *d = container_of(work, struct aoedev, work);
 414
 415         if (d->flags & DEVFL_GDALLOC)
 416                 aoeblk_gdalloc(d);
 417
 418         if (d->flags & DEVFL_NEWSIZE) {
 419                 struct block_device *bd;
 420                 unsigned long flags;
 421                 u64 ssize;
 422
 423                 ssize = d->gd->capacity;
 424                 bd = bdget_disk(d->gd, 0);
 425
 426                 if (bd) {
 427                         mutex_lock(&bd->bd_inode->i_mutex);
 428                         i_size_write(bd->bd_inode, (loff_t)ssize<<9);
 429                         mutex_unlock(&bd->bd_inode->i_mutex);
 430                         bdput(bd);
 431                 }
 432                 spin_lock_irqsave(&d->lock, flags);
 433                 d->flags |= DEVFL_UP;
 434                 d->flags &= ~DEVFL_NEWSIZE;
 435                 spin_unlock_irqrestore(&d->lock, flags);
 436         }
 437 }
 438
 439 static void
 440 ataid_complete(struct aoedev *d, unsigned char *id)
 441 {
 442         u64 ssize;
 443         u16 n;
 444
 445         /* word 83: command set supported */
 446         n = le16_to_cpu(get_unaligned((__le16 *) &id[83<<1]));
 447
 448         /* word 86: command set/feature enabled */
 449         n |= le16_to_cpu(get_unaligned((__le16 *) &id[86<<1]));
 450
 451         if (n & (1<<10)) {      /* bit 10: LBA 48 */
 452                 d->flags |= DEVFL_EXT;
 453
 454                 /* word 100: number lba48 sectors */
 455                 ssize = le64_to_cpu(get_unaligned((__le64 *) &id[100<<1]));
 456
 457                 /* set as in ide-disk.c:init_idedisk_capacity */
 458                 d->geo.cylinders = ssize;
 459                 d->geo.cylinders /= (255 * 63);
 460                 d->geo.heads = 255;
 461                 d->geo.sectors = 63;
 462         } else {
 463                 d->flags &= ~DEVFL_EXT;
 464
 465                 /* number lba28 sectors */
 466                 ssize = le32_to_cpu(get_unaligned((__le32 *) &id[60<<1]));
 467
 468                 /* NOTE: obsolete in ATA 6 */
 469                 d->geo.cylinders = le16_to_cpu(get_unaligned((__le16 *) &id[54<<1]));
 470                 d->geo.heads = le16_to_cpu(get_unaligned((__le16 *) &id[55<<1]));
 471                 d->geo.sectors = le16_to_cpu(get_unaligned((__le16 *) &id[56<<1]));
 472         }
 473
 474         if (d->ssize != ssize)
 475                 printk(KERN_INFO "aoe: %012llx e%lu.%lu v%04x has %llu sectors\n",
 476                         (unsigned long long)mac_addr(d->addr),
 477                         d->aoemajor, d->aoeminor,
 478                         d->fw_ver, (long long)ssize);
 479         d->ssize = ssize;
 480         d->geo.start = 0;
 481         if (d->gd != NULL) {
 482                 d->gd->capacity = ssize;
 483                 d->flags |= DEVFL_NEWSIZE;
 484         } else {
 485                 if (d->flags & DEVFL_GDALLOC) {
 486                         printk(KERN_ERR "aoe: can't schedule work for e%lu.%lu, %s\n",
 487                                d->aoemajor, d->aoeminor,
 488                                "it's already on!  This shouldn't happen.\n");
 489                         return;
 490                 }
 491                 d->flags |= DEVFL_GDALLOC;
 492         }
 493         schedule_work(&d->work);
 494 }
 495
 496 static void
 497 calc_rttavg(struct aoedev *d, int rtt)
 498 {
 499         register long n;
 500
 501         n = rtt;
 502         if (n < 0) {
 503                 n = -rtt;
 504                 if (n < MINTIMER)
 505                         n = MINTIMER;
 506                 else if (n > MAXTIMER)
 507                         n = MAXTIMER;
 508                 d->mintimer += (n - d->mintimer) >> 1;
 509         } else if (n < d->mintimer)
 510                 n = d->mintimer;
 511         else if (n > MAXTIMER)
 512                 n = MAXTIMER;
 513
 514         /* g == .25; cf. Congestion Avoidance and Control, Jacobson & Karels; 1988 */
 515         n -= d->rttavg;
 516         d->rttavg += n >> 2;
 517 }
 518
 519 void
 520 aoecmd_ata_rsp(struct sk_buff *skb)
 521 {
 522         struct aoedev *d;
 523         struct aoe_hdr *hin, *hout;
 524         struct aoe_atahdr *ahin, *ahout;
 525         struct frame *f;
 526         struct buf *buf;
 527         struct sk_buff *sl;
 528         register long n;
 529         ulong flags;
 530         char ebuf[128];
 531         u16 aoemajor;
 532
 533         hin = (struct aoe_hdr *) skb->mac.raw;
 534         aoemajor = be16_to_cpu(hin->major);
 535         d = aoedev_by_aoeaddr(aoemajor, hin->minor);
 536         if (d == NULL) {
 537                 snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "
 538                         "for unknown device %d.%d\n",
 539                          aoemajor, hin->minor);
 540                 aoechr_error(ebuf);
 541                 return;
 542         }
 543
 544         spin_lock_irqsave(&d->lock, flags);
 545
 546         n = be32_to_cpu(hin->tag);
 547         f = getframe(d, n);
 548         if (f == NULL) {
 549                 calc_rttavg(d, -tsince(n));
 550                 spin_unlock_irqrestore(&d->lock, flags);
 551                 snprintf(ebuf, sizeof ebuf,
 552                         "%15s e%d.%d    tag=%08x@%08lx\n",
 553                         "unexpected rsp",
 554                         be16_to_cpu(hin->major),
 555                         hin->minor,
 556                         be32_to_cpu(hin->tag),
 557                         jiffies);
 558                 aoechr_error(ebuf);
 559                 return;
 560         }
 561
 562         calc_rttavg(d, tsince(f->tag));
 563
 564         ahin = (struct aoe_atahdr *) (hin+1);
 565         hout = (struct aoe_hdr *) f->skb->mac.raw;
 566         ahout = (struct aoe_atahdr *) (hout+1);
 567         buf = f->buf;
 568
 569         if (ahout->cmdstat == WIN_IDENTIFY)
 570                 d->flags &= ~DEVFL_PAUSE;
 571         if (ahin->cmdstat & 0xa9) {     /* these bits cleared on success */
 572                 printk(KERN_ERR
 573                         "aoe: ata error cmd=%2.2Xh stat=%2.2Xh from e%ld.%ld\n",
 574                         ahout->cmdstat, ahin->cmdstat,
 575                         d->aoemajor, d->aoeminor);
 576                 if (buf)
 577                         buf->flags |= BUFFL_FAIL;
 578         } else {
 579                 n = ahout->scnt << 9;
 580                 switch (ahout->cmdstat) {
 581                 case WIN_READ:
 582                 case WIN_READ_EXT:
 583                         if (skb->len - sizeof *hin - sizeof *ahin < n) {
 584                                 printk(KERN_ERR
 585                                         "aoe: runt data size in read.  skb->len=%d\n",
 586                                         skb->len);
 587                                 /* fail frame f?  just returning will rexmit. */
 588                                 spin_unlock_irqrestore(&d->lock, flags);
 589                                 return;
 590                         }
 591                         memcpy(f->bufaddr, ahin+1, n);
 592                 case WIN_WRITE:
 593                 case WIN_WRITE_EXT:
 594                         if (f->bcnt -= n) {
 595                                 skb = f->skb;
 596                                 f->bufaddr += n;
 597                                 put_lba(ahout, f->lba += ahout->scnt);
 598                                 n = f->bcnt;
 599                                 if (n > DEFAULTBCNT)
 600                                         n = DEFAULTBCNT;
 601                                 ahout->scnt = n >> 9;
 602                                 if (ahout->aflags & AOEAFL_WRITE) {
 603                                         skb_fill_page_desc(skb, 0,
 604                                                 virt_to_page(f->bufaddr),
 605                                                 offset_in_page(f->bufaddr), n);
 606                                         skb->len = sizeof *hout + sizeof *ahout + n;
 607                                         skb->data_len = n;
 608                                 }
 609                                 f->tag = newtag(d);
 610                                 hout->tag = cpu_to_be32(f->tag);
 611                                 skb->dev = d->ifp;
 612                                 skb = skb_clone(skb, GFP_ATOMIC);
 613                                 spin_unlock_irqrestore(&d->lock, flags);
 614                                 if (skb)
 615                                         aoenet_xmit(skb);
 616                                 return;
 617                         }
 618                         if (n > DEFAULTBCNT)
 619                                 d->lostjumbo = 0;
 620                         break;
 621                 case WIN_IDENTIFY:
 622                         if (skb->len - sizeof *hin - sizeof *ahin < 512) {
 623                                 printk(KERN_INFO
 624                                         "aoe: runt data size in ataid.  skb->len=%d\n",
 625                                         skb->len);
 626                                 spin_unlock_irqrestore(&d->lock, flags);
 627                                 return;
 628                         }
 629                         ataid_complete(d, (char *) (ahin+1));
 630                         break;
 631                 default:
 632                         printk(KERN_INFO
 633                                 "aoe: unrecognized ata command %2.2Xh for %d.%d\n",
 634                                 ahout->cmdstat,
 635                                 be16_to_cpu(hin->major),
 636                                 hin->minor);
 637                 }
 638         }
 639
 640         if (buf) {
 641                 buf->nframesout -= 1;
 642                 if (buf->nframesout == 0 && buf->resid == 0) {
 643                         unsigned long duration = jiffies - buf->start_time;
 644                         unsigned long n_sect = buf->bio->bi_size >> 9;
 645                         struct gendisk *disk = d->gd;
 646                         const int rw = bio_data_dir(buf->bio);
 647
 648                         disk_stat_inc(disk, ios[rw]);
 649                         disk_stat_add(disk, ticks[rw], duration);
 650                         disk_stat_add(disk, sectors[rw], n_sect);
 651                         disk_stat_add(disk, io_ticks, duration);
 652                         n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;
 653                         bio_endio(buf->bio, buf->bio->bi_size, n);
 654                         mempool_free(buf, d->bufpool);
 655                 }
 656         }
 657
 658         f->buf = NULL;
 659         f->tag = FREETAG;
 660
 661         aoecmd_work(d);
 662         sl = d->sendq_hd;
 663         d->sendq_hd = d->sendq_tl = NULL;
 664
 665         spin_unlock_irqrestore(&d->lock, flags);
 666         aoenet_xmit(sl);
 667 }
 668
 669 void
 670 aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
 671 {
 672         struct sk_buff *sl;
 673
 674         sl = aoecmd_cfg_pkts(aoemajor, aoeminor, NULL);
 675
 676         aoenet_xmit(sl);
 677 }
 678
 679 /*
 680  * Since we only call this in one place (and it only prepares one frame)
 681  * we just return the skb.  Usually we'd chain it up to the aoedev sendq.
 682  */
 683 static struct sk_buff *
 684 aoecmd_ata_id(struct aoedev *d)
 685 {
 686         struct aoe_hdr *h;
 687         struct aoe_atahdr *ah;
 688         struct frame *f;
 689         struct sk_buff *skb;
 690
 691         f = freeframe(d);
 692         if (f == NULL) {
 693                 printk(KERN_ERR "aoe: can't get a frame. This shouldn't happen.\n");
 694                 return NULL;
 695         }
 696
 697         /* initialize the headers & frame */
 698         skb = f->skb;
 699         h = (struct aoe_hdr *) skb->mac.raw;
 700         ah = (struct aoe_atahdr *) (h+1);
 701         skb->len = ETH_ZLEN;
 702         memset(h, 0, ETH_ZLEN);
 703         f->tag = aoehdr_atainit(d, h);
 704         f->waited = 0;
 705
 706         /* set up ata header */
 707         ah->scnt = 1;
 708         ah->cmdstat = WIN_IDENTIFY;
 709         ah->lba3 = 0xa0;
 710
 711         skb->dev = d->ifp;
 712
 713         d->rttavg = MAXTIMER;
 714         d->timer.function = rexmit_timer;
 715
 716         return skb_clone(skb, GFP_ATOMIC);
 717 }
 718
 719 void
 720 aoecmd_cfg_rsp(struct sk_buff *skb)
 721 {
 722         struct aoedev *d;
 723         struct aoe_hdr *h;
 724         struct aoe_cfghdr *ch;
 725         ulong flags, sysminor, aoemajor;
 726         struct sk_buff *sl;
 727         enum { MAXFRAMES = 16 };
 728         u16 n;
 729
 730         h = (struct aoe_hdr *) skb->mac.raw;
 731         ch = (struct aoe_cfghdr *) (h+1);
 732
 733         /*
 734          * Enough people have their dip switches set backwards to
 735          * warrant a loud message for this special case.
 736          */
 737         aoemajor = be16_to_cpu(h->major);
 738         if (aoemajor == 0xfff) {
 739                 printk(KERN_ERR "aoe: Warning: shelf address is all ones.  "
 740                         "Check shelf dip switches.\n");
 741                 return;
 742         }
 743
 744         sysminor = SYSMINOR(aoemajor, h->minor);
 745         if (sysminor * AOE_PARTITIONS + AOE_PARTITIONS > MINORMASK) {
 746                 printk(KERN_INFO "aoe: e%ld.%d: minor number too large\n",
 747                         aoemajor, (int) h->minor);
 748                 return;
 749         }
 750
 751         n = be16_to_cpu(ch->bufcnt);
 752         if (n > MAXFRAMES)      /* keep it reasonable */
 753                 n = MAXFRAMES;
 754
 755         d = aoedev_by_sysminor_m(sysminor, n);
 756         if (d == NULL) {
 757                 printk(KERN_INFO "aoe: device sysminor_m failure\n");
 758                 return;
 759         }
 760
 761         spin_lock_irqsave(&d->lock, flags);
 762
 763         /* permit device to migrate mac and network interface */
 764         d->ifp = skb->dev;
 765         memcpy(d->addr, h->src, sizeof d->addr);
 766         if (!(d->flags & DEVFL_MAXBCNT)) {
 767                 n = d->ifp->mtu;
 768                 n -= sizeof (struct aoe_hdr) + sizeof (struct aoe_atahdr);
 769                 n /= 512;
 770                 if (n > ch->scnt)
 771                         n = ch->scnt;
 772                 n = n ? n * 512 : DEFAULTBCNT;
 773                 if (n != d->maxbcnt) {
 774                         printk(KERN_INFO
 775                                 "aoe: e%ld.%ld: setting %d byte data frames on %s\n",
 776                                 d->aoemajor, d->aoeminor, n, d->ifp->name);
 777                         d->maxbcnt = n;
 778                 }
 779         }
 780
 781         /* don't change users' perspective */
 782         if (d->nopen && !(d->flags & DEVFL_PAUSE)) {
 783                 spin_unlock_irqrestore(&d->lock, flags);
 784                 return;
 785         }
 786         d->flags |= DEVFL_PAUSE;        /* force pause */
 787         d->mintimer = MINTIMER;
 788         d->fw_ver = be16_to_cpu(ch->fwver);
 789
 790         /* check for already outstanding ataid */
 791         sl = aoedev_isbusy(d) == 0 ? aoecmd_ata_id(d) : NULL;
 792
 793         spin_unlock_irqrestore(&d->lock, flags);
 794
 795         aoenet_xmit(sl);
 796 }
 797