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 <net/net_namespace.h>
  13 #include <asm/unaligned.h>
  14 #include "aoe.h"
  15
  16 #define TIMERTICK (HZ / 10)
  17 #define MINTIMER (2 * TIMERTICK)
  18 #define MAXTIMER (HZ << 1)
  19
  20 static int aoe_deadsecs = 60 * 3;
  21 module_param(aoe_deadsecs, int, 0644);
  22 MODULE_PARM_DESC(aoe_deadsecs, "After aoe_deadsecs seconds, give up and fail dev.");
  23
  24 struct sk_buff *
  25 new_skb(ulong len)
  26 {
  27         struct sk_buff *skb;
  28
  29         skb = alloc_skb(len, GFP_ATOMIC);
  30         if (skb) {
  31                 skb_reset_mac_header(skb);
  32                 skb_reset_network_header(skb);
  33                 skb->protocol = __constant_htons(ETH_P_AOE);
  34                 skb->priority = 0;
  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 = aoe_hdr(skb);
 124         ah = (struct aoe_atahdr *) (h+1);
 125         skb_put(skb, sizeof *h + sizeof *ah);
 126         memset(h, 0, skb->len);
 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                 writebit = 0;
 153         }
 154
 155         ah->cmdstat = WIN_READ | writebit | extbit;
 156
 157         /* mark all tracking fields and load out */
 158         buf->nframesout += 1;
 159         buf->bufaddr += bcnt;
 160         buf->bv_resid -= bcnt;
 161 /* printk(KERN_DEBUG "aoe: bv_resid=%ld\n", buf->bv_resid); */
 162         buf->resid -= bcnt;
 163         buf->sector += bcnt >> 9;
 164         if (buf->resid == 0) {
 165                 d->inprocess = NULL;
 166         } else if (buf->bv_resid == 0) {
 167                 buf->bv++;
 168                 WARN_ON(buf->bv->bv_len == 0);
 169                 buf->bv_resid = buf->bv->bv_len;
 170                 buf->bufaddr = page_address(buf->bv->bv_page) + buf->bv->bv_offset;
 171         }
 172
 173         skb->dev = d->ifp;
 174         skb = skb_clone(skb, GFP_ATOMIC);
 175         if (skb == NULL)
 176                 return;
 177         if (d->sendq_hd)
 178                 d->sendq_tl->next = skb;
 179         else
 180                 d->sendq_hd = skb;
 181         d->sendq_tl = skb;
 182 }
 183
 184 /* some callers cannot sleep, and they can call this function,
 185  * transmitting the packets later, when interrupts are on
 186  */
 187 static struct sk_buff *
 188 aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
 189 {
 190         struct aoe_hdr *h;
 191         struct aoe_cfghdr *ch;
 192         struct sk_buff *skb, *sl, *sl_tail;
 193         struct net_device *ifp;
 194
 195         sl = sl_tail = NULL;
 196
 197         read_lock(&dev_base_lock);
 198         for_each_netdev(&init_net, ifp) {
 199                 dev_hold(ifp);
 200                 if (!is_aoe_netif(ifp))
 201                         goto cont;
 202
 203                 skb = new_skb(sizeof *h + sizeof *ch);
 204                 if (skb == NULL) {
 205                         printk(KERN_INFO "aoe: skb alloc failure\n");
 206                         goto cont;
 207                 }
 208                 skb_put(skb, sizeof *h + sizeof *ch);
 209                 skb->dev = ifp;
 210                 if (sl_tail == NULL)
 211                         sl_tail = skb;
 212                 h = aoe_hdr(skb);
 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 cont:
 226                 dev_put(ifp);
 227         }
 228         read_unlock(&dev_base_lock);
 229
 230         if (tail != NULL)
 231                 *tail = sl_tail;
 232         return sl;
 233 }
 234
 235 static struct frame *
 236 freeframe(struct aoedev *d)
 237 {
 238         struct frame *f, *e;
 239         int n = 0;
 240
 241         f = d->frames;
 242         e = f + d->nframes;
 243         for (; f<e; f++) {
 244                 if (f->tag != FREETAG)
 245                         continue;
 246                 if (atomic_read(&skb_shinfo(f->skb)->dataref) == 1) {
 247                         skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;
 248                         skb_trim(f->skb, 0);
 249                         return f;
 250                 }
 251                 n++;
 252         }
 253         if (n == d->nframes)    /* wait for network layer */
 254                 d->flags |= DEVFL_KICKME;
 255
 256         return NULL;
 257 }
 258
 259 /* enters with d->lock held */
 260 void
 261 aoecmd_work(struct aoedev *d)
 262 {
 263         struct frame *f;
 264         struct buf *buf;
 265
 266         if (d->flags & DEVFL_PAUSE) {
 267                 if (!aoedev_isbusy(d))
 268                         d->sendq_hd = aoecmd_cfg_pkts(d->aoemajor,
 269                                                 d->aoeminor, &d->sendq_tl);
 270                 return;
 271         }
 272
 273 loop:
 274         f = freeframe(d);
 275         if (f == NULL)
 276                 return;
 277         if (d->inprocess == NULL) {
 278                 if (list_empty(&d->bufq))
 279                         return;
 280                 buf = container_of(d->bufq.next, struct buf, bufs);
 281                 list_del(d->bufq.next);
 282 /*printk(KERN_DEBUG "aoe: bi_size=%ld\n", buf->bio->bi_size); */
 283                 d->inprocess = buf;
 284         }
 285         aoecmd_ata_rw(d, f);
 286         goto loop;
 287 }
 288
 289 static void
 290 rexmit(struct aoedev *d, struct frame *f)
 291 {
 292         struct sk_buff *skb;
 293         struct aoe_hdr *h;
 294         struct aoe_atahdr *ah;
 295         char buf[128];
 296         u32 n;
 297
 298         n = newtag(d);
 299
 300         snprintf(buf, sizeof buf,
 301                 "%15s e%ld.%ld oldtag=%08x@%08lx newtag=%08x\n",
 302                 "retransmit",
 303                 d->aoemajor, d->aoeminor, f->tag, jiffies, n);
 304         aoechr_error(buf);
 305
 306         skb = f->skb;
 307         h = aoe_hdr(skb);
 308         ah = (struct aoe_atahdr *) (h+1);
 309         f->tag = n;
 310         h->tag = cpu_to_be32(n);
 311         memcpy(h->dst, d->addr, sizeof h->dst);
 312         memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
 313
 314         n = DEFAULTBCNT / 512;
 315         if (ah->scnt > n) {
 316                 ah->scnt = n;
 317                 if (ah->aflags & AOEAFL_WRITE) {
 318                         skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),
 319                                 offset_in_page(f->bufaddr), DEFAULTBCNT);
 320                         skb->len = sizeof *h + sizeof *ah + DEFAULTBCNT;
 321                         skb->data_len = DEFAULTBCNT;
 322                 }
 323                 if (++d->lostjumbo > (d->nframes << 1))
 324                 if (d->maxbcnt != DEFAULTBCNT) {
 325                         printk(KERN_INFO "aoe: e%ld.%ld: too many lost jumbo on %s - using 1KB frames.\n",
 326                                 d->aoemajor, d->aoeminor, d->ifp->name);
 327                         d->maxbcnt = DEFAULTBCNT;
 328                         d->flags |= DEVFL_MAXBCNT;
 329                 }
 330         }
 331
 332         skb->dev = d->ifp;
 333         skb = skb_clone(skb, GFP_ATOMIC);
 334         if (skb == NULL)
 335                 return;
 336         if (d->sendq_hd)
 337                 d->sendq_tl->next = skb;
 338         else
 339                 d->sendq_hd = skb;
 340         d->sendq_tl = skb;
 341 }
 342
 343 static int
 344 tsince(int tag)
 345 {
 346         int n;
 347
 348         n = jiffies & 0xffff;
 349         n -= tag & 0xffff;
 350         if (n < 0)
 351                 n += 1<<16;
 352         return n;
 353 }
 354
 355 static void
 356 rexmit_timer(ulong vp)
 357 {
 358         struct aoedev *d;
 359         struct frame *f, *e;
 360         struct sk_buff *sl;
 361         register long timeout;
 362         ulong flags, n;
 363
 364         d = (struct aoedev *) vp;
 365         sl = NULL;
 366
 367         /* timeout is always ~150% of the moving average */
 368         timeout = d->rttavg;
 369         timeout += timeout >> 1;
 370
 371         spin_lock_irqsave(&d->lock, flags);
 372
 373         if (d->flags & DEVFL_TKILL) {
 374                 spin_unlock_irqrestore(&d->lock, flags);
 375                 return;
 376         }
 377         f = d->frames;
 378         e = f + d->nframes;
 379         for (; f<e; f++) {
 380                 if (f->tag != FREETAG && tsince(f->tag) >= timeout) {
 381                         n = f->waited += timeout;
 382                         n /= HZ;
 383                         if (n > aoe_deadsecs) { /* waited too long for response */
 384                                 aoedev_downdev(d);
 385                                 break;
 386                         }
 387                         rexmit(d, f);
 388                 }
 389         }
 390         if (d->flags & DEVFL_KICKME) {
 391                 d->flags &= ~DEVFL_KICKME;
 392                 aoecmd_work(d);
 393         }
 394
 395         sl = d->sendq_hd;
 396         d->sendq_hd = d->sendq_tl = NULL;
 397         if (sl) {
 398                 n = d->rttavg <<= 1;
 399                 if (n > MAXTIMER)
 400                         d->rttavg = MAXTIMER;
 401         }
 402
 403         d->timer.expires = jiffies + TIMERTICK;
 404         add_timer(&d->timer);
 405
 406         spin_unlock_irqrestore(&d->lock, flags);
 407
 408         aoenet_xmit(sl);
 409 }
 410
 411 /* this function performs work that has been deferred until sleeping is OK
 412  */
 413 void
 414 aoecmd_sleepwork(struct work_struct *work)
 415 {
 416         struct aoedev *d = container_of(work, struct aoedev, work);
 417
 418         if (d->flags & DEVFL_GDALLOC)
 419                 aoeblk_gdalloc(d);
 420
 421         if (d->flags & DEVFL_NEWSIZE) {
 422                 struct block_device *bd;
 423                 unsigned long flags;
 424                 u64 ssize;
 425
 426                 ssize = d->gd->capacity;
 427                 bd = bdget_disk(d->gd, 0);
 428
 429                 if (bd) {
 430                         mutex_lock(&bd->bd_inode->i_mutex);
 431                         i_size_write(bd->bd_inode, (loff_t)ssize<<9);
 432                         mutex_unlock(&bd->bd_inode->i_mutex);
 433                         bdput(bd);
 434                 }
 435                 spin_lock_irqsave(&d->lock, flags);
 436                 d->flags |= DEVFL_UP;
 437                 d->flags &= ~DEVFL_NEWSIZE;
 438                 spin_unlock_irqrestore(&d->lock, flags);
 439         }
 440 }
 441
 442 static void
 443 ataid_complete(struct aoedev *d, unsigned char *id)
 444 {
 445         u64 ssize;
 446         u16 n;
 447
 448         /* word 83: command set supported */
 449         n = le16_to_cpu(get_unaligned((__le16 *) &id[83<<1]));
 450
 451         /* word 86: command set/feature enabled */
 452         n |= le16_to_cpu(get_unaligned((__le16 *) &id[86<<1]));
 453
 454         if (n & (1<<10)) {      /* bit 10: LBA 48 */
 455                 d->flags |= DEVFL_EXT;
 456
 457                 /* word 100: number lba48 sectors */
 458                 ssize = le64_to_cpu(get_unaligned((__le64 *) &id[100<<1]));
 459
 460                 /* set as in ide-disk.c:init_idedisk_capacity */
 461                 d->geo.cylinders = ssize;
 462                 d->geo.cylinders /= (255 * 63);
 463                 d->geo.heads = 255;
 464                 d->geo.sectors = 63;
 465         } else {
 466                 d->flags &= ~DEVFL_EXT;
 467
 468                 /* number lba28 sectors */
 469                 ssize = le32_to_cpu(get_unaligned((__le32 *) &id[60<<1]));
 470
 471                 /* NOTE: obsolete in ATA 6 */
 472                 d->geo.cylinders = le16_to_cpu(get_unaligned((__le16 *) &id[54<<1]));
 473                 d->geo.heads = le16_to_cpu(get_unaligned((__le16 *) &id[55<<1]));
 474                 d->geo.sectors = le16_to_cpu(get_unaligned((__le16 *) &id[56<<1]));
 475         }
 476
 477         if (d->ssize != ssize)
 478                 printk(KERN_INFO "aoe: %012llx e%lu.%lu v%04x has %llu sectors\n",
 479                         (unsigned long long)mac_addr(d->addr),
 480                         d->aoemajor, d->aoeminor,
 481                         d->fw_ver, (long long)ssize);
 482         d->ssize = ssize;
 483         d->geo.start = 0;
 484         if (d->gd != NULL) {
 485                 d->gd->capacity = ssize;
 486                 d->flags |= DEVFL_NEWSIZE;
 487         } else {
 488                 if (d->flags & DEVFL_GDALLOC) {
 489                         printk(KERN_ERR "aoe: can't schedule work for e%lu.%lu, %s\n",
 490                                d->aoemajor, d->aoeminor,
 491                                "it's already on!  This shouldn't happen.\n");
 492                         return;
 493                 }
 494                 d->flags |= DEVFL_GDALLOC;
 495         }
 496         schedule_work(&d->work);
 497 }
 498
 499 static void
 500 calc_rttavg(struct aoedev *d, int rtt)
 501 {
 502         register long n;
 503
 504         n = rtt;
 505         if (n < 0) {
 506                 n = -rtt;
 507                 if (n < MINTIMER)
 508                         n = MINTIMER;
 509                 else if (n > MAXTIMER)
 510                         n = MAXTIMER;
 511                 d->mintimer += (n - d->mintimer) >> 1;
 512         } else if (n < d->mintimer)
 513                 n = d->mintimer;
 514         else if (n > MAXTIMER)
 515                 n = MAXTIMER;
 516
 517         /* g == .25; cf. Congestion Avoidance and Control, Jacobson & Karels; 1988 */
 518         n -= d->rttavg;
 519         d->rttavg += n >> 2;
 520 }
 521
 522 void
 523 aoecmd_ata_rsp(struct sk_buff *skb)
 524 {
 525         struct aoedev *d;
 526         struct aoe_hdr *hin, *hout;
 527         struct aoe_atahdr *ahin, *ahout;
 528         struct frame *f;
 529         struct buf *buf;
 530         struct sk_buff *sl;
 531         register long n;
 532         ulong flags;
 533         char ebuf[128];
 534         u16 aoemajor;
 535
 536         hin = aoe_hdr(skb);
 537         aoemajor = be16_to_cpu(get_unaligned(&hin->major));
 538         d = aoedev_by_aoeaddr(aoemajor, hin->minor);
 539         if (d == NULL) {
 540                 snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "
 541                         "for unknown device %d.%d\n",
 542                          aoemajor, hin->minor);
 543                 aoechr_error(ebuf);
 544                 return;
 545         }
 546
 547         spin_lock_irqsave(&d->lock, flags);
 548
 549         n = be32_to_cpu(get_unaligned(&hin->tag));
 550         f = getframe(d, n);
 551         if (f == NULL) {
 552                 calc_rttavg(d, -tsince(n));
 553                 spin_unlock_irqrestore(&d->lock, flags);
 554                 snprintf(ebuf, sizeof ebuf,
 555                         "%15s e%d.%d    tag=%08x@%08lx\n",
 556                         "unexpected rsp",
 557                         be16_to_cpu(get_unaligned(&hin->major)),
 558                         hin->minor,
 559                         be32_to_cpu(get_unaligned(&hin->tag)),
 560                         jiffies);
 561                 aoechr_error(ebuf);
 562                 return;
 563         }
 564
 565         calc_rttavg(d, tsince(f->tag));
 566
 567         ahin = (struct aoe_atahdr *) (hin+1);
 568         hout = aoe_hdr(f->skb);
 569         ahout = (struct aoe_atahdr *) (hout+1);
 570         buf = f->buf;
 571
 572         if (ahout->cmdstat == WIN_IDENTIFY)
 573                 d->flags &= ~DEVFL_PAUSE;
 574         if (ahin->cmdstat & 0xa9) {     /* these bits cleared on success */
 575                 printk(KERN_ERR
 576                         "aoe: ata error cmd=%2.2Xh stat=%2.2Xh from e%ld.%ld\n",
 577                         ahout->cmdstat, ahin->cmdstat,
 578                         d->aoemajor, d->aoeminor);
 579                 if (buf)
 580                         buf->flags |= BUFFL_FAIL;
 581         } else {
 582                 n = ahout->scnt << 9;
 583                 switch (ahout->cmdstat) {
 584                 case WIN_READ:
 585                 case WIN_READ_EXT:
 586                         if (skb->len - sizeof *hin - sizeof *ahin < n) {
 587                                 printk(KERN_ERR
 588                                         "aoe: runt data size in read.  skb->len=%d\n",
 589                                         skb->len);
 590                                 /* fail frame f?  just returning will rexmit. */
 591                                 spin_unlock_irqrestore(&d->lock, flags);
 592                                 return;
 593                         }
 594                         memcpy(f->bufaddr, ahin+1, n);
 595                 case WIN_WRITE:
 596                 case WIN_WRITE_EXT:
 597                         if (f->bcnt -= n) {
 598                                 skb = f->skb;
 599                                 f->bufaddr += n;
 600                                 put_lba(ahout, f->lba += ahout->scnt);
 601                                 n = f->bcnt;
 602                                 if (n > DEFAULTBCNT)
 603                                         n = DEFAULTBCNT;
 604                                 ahout->scnt = n >> 9;
 605                                 if (ahout->aflags & AOEAFL_WRITE) {
 606                                         skb_fill_page_desc(skb, 0,
 607                                                 virt_to_page(f->bufaddr),
 608                                                 offset_in_page(f->bufaddr), n);
 609                                         skb->len = sizeof *hout + sizeof *ahout + n;
 610                                         skb->data_len = n;
 611                                 }
 612                                 f->tag = newtag(d);
 613                                 hout->tag = cpu_to_be32(f->tag);
 614                                 skb->dev = d->ifp;
 615                                 skb = skb_clone(skb, GFP_ATOMIC);
 616                                 spin_unlock_irqrestore(&d->lock, flags);
 617                                 if (skb)
 618                                         aoenet_xmit(skb);
 619                                 return;
 620                         }
 621                         if (n > DEFAULTBCNT)
 622                                 d->lostjumbo = 0;
 623                         break;
 624                 case WIN_IDENTIFY:
 625                         if (skb->len - sizeof *hin - sizeof *ahin < 512) {
 626                                 printk(KERN_INFO
 627                                         "aoe: runt data size in ataid.  skb->len=%d\n",
 628                                         skb->len);
 629                                 spin_unlock_irqrestore(&d->lock, flags);
 630                                 return;
 631                         }
 632                         ataid_complete(d, (char *) (ahin+1));
 633                         break;
 634                 default:
 635                         printk(KERN_INFO
 636                                 "aoe: unrecognized ata command %2.2Xh for %d.%d\n",
 637                                 ahout->cmdstat,
 638                                 be16_to_cpu(get_unaligned(&hin->major)),
 639                                 hin->minor);
 640                 }
 641         }
 642
 643         if (buf) {
 644                 buf->nframesout -= 1;
 645                 if (buf->nframesout == 0 && buf->resid == 0) {
 646                         unsigned long duration = jiffies - buf->start_time;
 647                         unsigned long n_sect = buf->bio->bi_size >> 9;
 648                         struct gendisk *disk = d->gd;
 649                         const int rw = bio_data_dir(buf->bio);
 650
 651                         disk_stat_inc(disk, ios[rw]);
 652                         disk_stat_add(disk, ticks[rw], duration);
 653                         disk_stat_add(disk, sectors[rw], n_sect);
 654                         disk_stat_add(disk, io_ticks, duration);
 655                         n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;
 656                         bio_endio(buf->bio, buf->bio->bi_size, n);
 657                         mempool_free(buf, d->bufpool);
 658                 }
 659         }
 660
 661         f->buf = NULL;
 662         f->tag = FREETAG;
 663
 664         aoecmd_work(d);
 665         sl = d->sendq_hd;
 666         d->sendq_hd = d->sendq_tl = NULL;
 667
 668         spin_unlock_irqrestore(&d->lock, flags);
 669         aoenet_xmit(sl);
 670 }
 671
 672 void
 673 aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
 674 {
 675         struct sk_buff *sl;
 676
 677         sl = aoecmd_cfg_pkts(aoemajor, aoeminor, NULL);
 678
 679         aoenet_xmit(sl);
 680 }
 681
 682 /*
 683  * Since we only call this in one place (and it only prepares one frame)
 684  * we just return the skb.  Usually we'd chain it up to the aoedev sendq.
 685  */
 686 static struct sk_buff *
 687 aoecmd_ata_id(struct aoedev *d)
 688 {
 689         struct aoe_hdr *h;
 690         struct aoe_atahdr *ah;
 691         struct frame *f;
 692         struct sk_buff *skb;
 693
 694         f = freeframe(d);
 695         if (f == NULL) {
 696                 printk(KERN_ERR "aoe: can't get a frame. This shouldn't happen.\n");
 697                 return NULL;
 698         }
 699
 700         /* initialize the headers & frame */
 701         skb = f->skb;
 702         h = aoe_hdr(skb);
 703         ah = (struct aoe_atahdr *) (h+1);
 704         skb_put(skb, sizeof *h + sizeof *ah);
 705         memset(h, 0, skb->len);
 706         f->tag = aoehdr_atainit(d, h);
 707         f->waited = 0;
 708
 709         /* set up ata header */
 710         ah->scnt = 1;
 711         ah->cmdstat = WIN_IDENTIFY;
 712         ah->lba3 = 0xa0;
 713
 714         skb->dev = d->ifp;
 715
 716         d->rttavg = MAXTIMER;
 717         d->timer.function = rexmit_timer;
 718
 719         return skb_clone(skb, GFP_ATOMIC);
 720 }
 721
 722 void
 723 aoecmd_cfg_rsp(struct sk_buff *skb)
 724 {
 725         struct aoedev *d;
 726         struct aoe_hdr *h;
 727         struct aoe_cfghdr *ch;
 728         ulong flags, sysminor, aoemajor;
 729         struct sk_buff *sl;
 730         enum { MAXFRAMES = 16 };
 731         u16 n;
 732
 733         h = aoe_hdr(skb);
 734         ch = (struct aoe_cfghdr *) (h+1);
 735
 736         /*
 737          * Enough people have their dip switches set backwards to
 738          * warrant a loud message for this special case.
 739          */
 740         aoemajor = be16_to_cpu(get_unaligned(&h->major));
 741         if (aoemajor == 0xfff) {
 742                 printk(KERN_ERR "aoe: Warning: shelf address is all ones.  "
 743                         "Check shelf dip switches.\n");
 744                 return;
 745         }
 746
 747         sysminor = SYSMINOR(aoemajor, h->minor);
 748         if (sysminor * AOE_PARTITIONS + AOE_PARTITIONS > MINORMASK) {
 749                 printk(KERN_INFO "aoe: e%ld.%d: minor number too large\n",
 750                         aoemajor, (int) h->minor);
 751                 return;
 752         }
 753
 754         n = be16_to_cpu(ch->bufcnt);
 755         if (n > MAXFRAMES)      /* keep it reasonable */
 756                 n = MAXFRAMES;
 757
 758         d = aoedev_by_sysminor_m(sysminor, n);
 759         if (d == NULL) {
 760                 printk(KERN_INFO "aoe: device sysminor_m failure\n");
 761                 return;
 762         }
 763
 764         spin_lock_irqsave(&d->lock, flags);
 765
 766         /* permit device to migrate mac and network interface */
 767         d->ifp = skb->dev;
 768         memcpy(d->addr, h->src, sizeof d->addr);
 769         if (!(d->flags & DEVFL_MAXBCNT)) {
 770                 n = d->ifp->mtu;
 771                 n -= sizeof (struct aoe_hdr) + sizeof (struct aoe_atahdr);
 772                 n /= 512;
 773                 if (n > ch->scnt)
 774                         n = ch->scnt;
 775                 n = n ? n * 512 : DEFAULTBCNT;
 776                 if (n != d->maxbcnt) {
 777                         printk(KERN_INFO
 778                                 "aoe: e%ld.%ld: setting %d byte data frames on %s\n",
 779                                 d->aoemajor, d->aoeminor, n, d->ifp->name);
 780                         d->maxbcnt = n;
 781                 }
 782         }
 783
 784         /* don't change users' perspective */
 785         if (d->nopen && !(d->flags & DEVFL_PAUSE)) {
 786                 spin_unlock_irqrestore(&d->lock, flags);
 787                 return;
 788         }
 789         d->flags |= DEVFL_PAUSE;        /* force pause */
 790         d->mintimer = MINTIMER;
 791         d->fw_ver = be16_to_cpu(ch->fwver);
 792
 793         /* check for already outstanding ataid */
 794         sl = aoedev_isbusy(d) == 0 ? aoecmd_ata_id(d) : NULL;
 795
 796         spin_unlock_irqrestore(&d->lock, flags);
 797
 798         aoenet_xmit(sl);
 799 }
 800