sys/bus/cam/scsi/scsi_target.c

   1 /*
   2  * Generic SCSI Target Kernel Mode Driver
   3  *
   4  * Copyright (c) 2002 Nate Lawson.
   5  * Copyright (c) 1998, 1999, 2001, 2002 Justin T. Gibbs.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions, and the following disclaimer,
  13  *    without modification, immediately at the beginning of the file.
  14  * 2. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/sys/cam/scsi/scsi_target.c,v 1.22.2.7 2003/02/18 22:07:10 njl Exp $
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/kernel.h>
  35 #include <sys/conf.h>
  36 #include <sys/device.h>
  37 #include <sys/malloc.h>
  38 #include <sys/vnode.h>
  39 #include <sys/devicestat.h>
  40 #include <sys/thread2.h>
  41 #include <sys/devfs.h>
  42
  43 #include "../cam.h"
  44 #include "../cam_ccb.h"
  45 #include "../cam_periph.h"
  46 #include "../cam_xpt_periph.h"
  47 #include "../cam_sim.h"
  48 #include "scsi_targetio.h"
  49
  50 /* Transaction information attached to each CCB sent by the user */
  51 struct targ_cmd_descr {
  52         struct cam_periph_map_info  mapinfo;
  53         TAILQ_ENTRY(targ_cmd_descr) tqe;
  54         union ccb *user_ccb;
  55         int        priority;
  56         int        func_code;
  57 };
  58
  59 /* Offset into the private CCB area for storing our descriptor */
  60 #define targ_descr      periph_priv.entries[1].ptr
  61
  62 TAILQ_HEAD(descr_queue, targ_cmd_descr);
  63
  64 typedef enum {
  65         TARG_STATE_RESV         = 0x00, /* Invalid state */
  66         TARG_STATE_OPENED       = 0x01, /* Device opened, softc initialized */
  67         TARG_STATE_LUN_ENABLED  = 0x02  /* Device enabled for a path */
  68 } targ_state;
  69
  70 /* Per-instance device software context */
  71 struct targ_softc {
  72         /* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
  73         struct ccb_queue         pending_ccb_queue;
  74
  75         /* Command descriptors awaiting CTIO resources from the XPT */
  76         struct descr_queue       work_queue;
  77
  78         /* Command descriptors that have been aborted back to the user. */
  79         struct descr_queue       abort_queue;
  80
  81         /*
  82          * Queue of CCBs that have been copied out to userland, but our
  83          * userland daemon has not yet seen.
  84          */
  85         struct ccb_queue         user_ccb_queue;
  86
  87         struct cam_periph       *periph;
  88         struct cam_path         *path;
  89         targ_state               state;
  90         struct kqinfo            read_kq;
  91         struct devstat           device_stats;
  92 };
  93
  94 static d_open_t         targopen;
  95 static d_close_t        targclose;
  96 static d_read_t         targread;
  97 static d_write_t        targwrite;
  98 static d_ioctl_t        targioctl;
  99 static d_kqfilter_t     targkqfilter;
 100 static d_clone_t        targclone;
 101 DEVFS_DECLARE_CLONE_BITMAP(targ);
 102
 103 static void             targfiltdetach(struct knote *kn);
 104 static int              targreadfilt(struct knote *kn, long hint);
 105 static int              targwritefilt(struct knote *kn, long hint);
 106 static struct filterops targread_filtops =
 107         { FILTEROP_ISFD, NULL, targfiltdetach, targreadfilt };
 108 static struct filterops targwrite_filtops =
 109         { FILTEROP_ISFD, NULL, targfiltdetach, targwritefilt };
 110
 111 static struct dev_ops targ_ops = {
 112         { "targ", 0, 0 },
 113         .d_open = targopen,
 114         .d_close = targclose,
 115         .d_read = targread,
 116         .d_write = targwrite,
 117         .d_ioctl = targioctl,
 118         .d_kqfilter = targkqfilter
 119 };
 120
 121 static cam_status       targendislun(struct cam_path *path, int enable,
 122                                      int grp6_len, int grp7_len);
 123 static cam_status       targenable(struct targ_softc *softc,
 124                                    struct cam_path *path,
 125                                    int grp6_len, int grp7_len);
 126 static cam_status       targdisable(struct targ_softc *softc);
 127 static periph_ctor_t    targctor;
 128 static periph_dtor_t    targdtor;
 129 static periph_start_t   targstart;
 130 static int              targusermerge(struct targ_softc *softc,
 131                                       struct targ_cmd_descr *descr,
 132                                       union ccb *ccb);
 133 static int              targsendccb(struct targ_softc *softc, union ccb *ccb,
 134                                     struct targ_cmd_descr *descr);
 135 static void             targdone(struct cam_periph *periph,
 136                                  union  ccb *done_ccb);
 137 static int              targreturnccb(struct targ_softc *softc,
 138                                       union  ccb *ccb);
 139 static union ccb *      targgetccb(struct targ_softc *softc, xpt_opcode type,
 140                                    int priority);
 141 static void             targfreeccb(struct targ_softc *softc, union ccb *ccb);
 142 static struct targ_cmd_descr *
 143                         targgetdescr(struct targ_softc *softc);
 144 static periph_init_t    targinit;
 145 static void             targasync(void *callback_arg, u_int32_t code,
 146                                   struct cam_path *path, void *arg);
 147 static void             abort_all_pending(struct targ_softc *softc);
 148 static void             notify_user(struct targ_softc *softc);
 149 static int              targcamstatus(cam_status status);
 150 static size_t           targccblen(xpt_opcode func_code);
 151
 152 static struct periph_driver targdriver =
 153 {
 154         targinit, "targ",
 155         TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
 156 };
 157 PERIPHDRIVER_DECLARE(targ, targdriver);
 158
 159 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
 160
 161 /*
 162  * Create softc and initialize it. Only one proc can open each targ device.
 163  * There is no locking here because a periph doesn't get created until an
 164  * ioctl is issued to do so, and that can't happen until this method returns.
 165  */
 166 static int
 167 targopen(struct dev_open_args *ap)
 168 {
 169         cdev_t dev = ap->a_head.a_dev;
 170         struct targ_softc *softc;
 171
 172         if (dev->si_drv1 != 0) {
 173                 return (EBUSY);
 174         }
 175
 176         /* Mark device busy before any potentially blocking operations */
 177         dev->si_drv1 = (void *)~0;
 178         reference_dev(dev);             /* save ref for later destroy_dev() */
 179
 180         /* Create the targ device, allocate its softc, initialize it */
 181 #if 0
 182         make_dev(&targ_ops, minor(dev), UID_ROOT, GID_WHEEL, 0600,
 183                          "targ%d", lminor(dev));
 184 #endif
 185         MALLOC(softc, struct targ_softc *, sizeof(*softc), M_TARG,
 186                M_INTWAIT | M_ZERO);
 187         dev->si_drv1 = softc;
 188         softc->state = TARG_STATE_OPENED;
 189         softc->periph = NULL;
 190         softc->path = NULL;
 191
 192         TAILQ_INIT(&softc->pending_ccb_queue);
 193         TAILQ_INIT(&softc->work_queue);
 194         TAILQ_INIT(&softc->abort_queue);
 195         TAILQ_INIT(&softc->user_ccb_queue);
 196
 197         return (0);
 198 }
 199
 200 /* Disable LUN if enabled and teardown softc */
 201 static int
 202 targclose(struct dev_close_args *ap)
 203 {
 204         cdev_t dev = ap->a_head.a_dev;
 205         struct targ_softc     *softc;
 206         struct cam_periph     *periph;
 207         int    error;
 208
 209         softc = (struct targ_softc *)dev->si_drv1;
 210         if ((softc->periph == NULL) ||
 211             (softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 212                 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(targ), dev->si_uminor);
 213                 destroy_dev(dev);
 214                 FREE(softc, M_TARG);
 215                 return (0);
 216         }
 217
 218         /*
 219          * Acquire a hold on the periph so that it doesn't go away before
 220          * we are ready at the end of the function.
 221          */
 222         periph = softc->periph;
 223         cam_periph_acquire(periph);
 224         cam_periph_lock(periph);
 225         error = targdisable(softc);
 226         if (error == CAM_REQ_CMP) {
 227                 dev->si_drv1 = 0;
 228                 if (softc->periph != NULL) {
 229                         cam_periph_invalidate(softc->periph);
 230                         softc->periph = NULL;
 231                 }
 232                 destroy_dev(dev);       /* eats the open ref */
 233                 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(targ), dev->si_uminor);
 234                 FREE(softc, M_TARG);
 235         } else {
 236                 release_dev(dev);
 237         }
 238         cam_periph_unlock(periph);
 239         cam_periph_release(periph);
 240
 241         return (error);
 242 }
 243
 244 /* Enable/disable LUNs, set debugging level */
 245 static int
 246 targioctl(struct dev_ioctl_args *ap)
 247 {
 248         struct targ_softc *softc;
 249         cam_status         status;
 250
 251         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 252
 253         switch (ap->a_cmd) {
 254         case TARGIOCENABLE:
 255         {
 256                 struct ioc_enable_lun   *new_lun;
 257                 struct cam_path         *path;
 258                 struct cam_sim          *sim;
 259
 260                 new_lun = (struct ioc_enable_lun *)ap->a_data;
 261                 status = xpt_create_path_unlocked(&path, /*periph*/NULL,
 262                                                   new_lun->path_id,
 263                                                   new_lun->target_id,
 264                                                   new_lun->lun_id);
 265                 if (status != CAM_REQ_CMP) {
 266                         kprintf("Couldn't create path, status %#x\n", status);
 267                         break;
 268                 }
 269                 sim = xpt_path_sim(path);
 270                 CAM_SIM_LOCK(sim);
 271                 status = targenable(softc, path, new_lun->grp6_len,
 272                                     new_lun->grp7_len);
 273                 xpt_free_path(path);
 274                 CAM_SIM_UNLOCK(sim);
 275                 break;
 276         }
 277         case TARGIOCDISABLE:
 278                 if (softc->periph == NULL) {
 279                         status = CAM_DEV_NOT_THERE;
 280                         break;
 281                 }
 282                 cam_periph_lock(softc->periph);
 283                 status = targdisable(softc);
 284                 cam_periph_unlock(softc->periph);
 285                 break;
 286         case TARGIOCDEBUG:
 287         {
 288 #ifdef  CAMDEBUG
 289                 struct ccb_debug cdbg;
 290
 291                 /* If no periph available, disallow debugging changes */
 292                 if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 293                         status = CAM_DEV_NOT_THERE;
 294                         break;
 295                 }
 296                 bzero(&cdbg, sizeof cdbg);
 297                 if (*((int *)ap->a_data) != 0)
 298                         cdbg.flags = CAM_DEBUG_PERIPH;
 299                 else
 300                         cdbg.flags = CAM_DEBUG_NONE;
 301                 cam_periph_lock(softc->periph);
 302                 xpt_setup_ccb(&cdbg.ccb_h, softc->path, /*priority*/0);
 303                 cdbg.ccb_h.func_code = XPT_DEBUG;
 304                 cdbg.ccb_h.cbfcnp = targdone;
 305
 306                 xpt_action((union ccb *)&cdbg);
 307                 cam_periph_unlock(softc->periph);
 308                 status = cdbg.ccb_h.status & CAM_STATUS_MASK;
 309 #else
 310                 status = CAM_FUNC_NOTAVAIL;
 311 #endif
 312                 break;
 313         }
 314         default:
 315                 status = CAM_PROVIDE_FAIL;
 316                 break;
 317         }
 318
 319         return (targcamstatus(status));
 320 }
 321
 322 static int
 323 targkqfilter(struct dev_kqfilter_args *ap)
 324 {
 325         struct  knote *kn = ap->a_kn;
 326         struct  targ_softc *softc;
 327
 328         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 329
 330         ap->a_result = 0;
 331
 332         switch (kn->kn_filter) {
 333         case EVFILT_READ:
 334                 kn->kn_hook = (caddr_t)softc;
 335                 kn->kn_fop = &targread_filtops;
 336                 break;
 337         case EVFILT_WRITE:
 338                 kn->kn_hook = (caddr_t)softc;
 339                 kn->kn_fop = &targwrite_filtops;
 340         default:
 341                 ap->a_result = EOPNOTSUPP;
 342                 return (0);
 343         }
 344
 345         knote_insert(&softc->read_kq.ki_note, kn);
 346         return (0);
 347 }
 348
 349 static void
 350 targfiltdetach(struct knote *kn)
 351 {
 352         struct  targ_softc *softc;
 353
 354         softc = (struct targ_softc *)kn->kn_hook;
 355         knote_remove(&softc->read_kq.ki_note, kn);
 356 }
 357
 358 /* Notify the user's kqueue when the user queue or abort queue gets a CCB */
 359 static int
 360 targreadfilt(struct knote *kn, long hint)
 361 {
 362         struct targ_softc *softc;
 363         int     retval;
 364
 365         softc = (struct targ_softc *)kn->kn_hook;
 366         cam_periph_lock(softc->periph);
 367         retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
 368                  !TAILQ_EMPTY(&softc->abort_queue);
 369         cam_periph_unlock(softc->periph);
 370         return (retval);
 371 }
 372
 373 /* write() is always ok */
 374 static int
 375 targwritefilt(struct knote *kn, long hint)
 376 {
 377         return (1);
 378 }
 379
 380 /* Send the HBA the enable/disable message */
 381 static cam_status
 382 targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
 383 {
 384         struct ccb_en_lun en_ccb;
 385         cam_status        status;
 386
 387         /* Tell the lun to begin answering selects */
 388         xpt_setup_ccb(&en_ccb.ccb_h, path, /*priority*/1);
 389         en_ccb.ccb_h.func_code = XPT_EN_LUN;
 390         /* Don't need support for any vendor specific commands */
 391         en_ccb.grp6_len = grp6_len;
 392         en_ccb.grp7_len = grp7_len;
 393         en_ccb.enable = enable ? 1 : 0;
 394         xpt_action((union ccb *)&en_ccb);
 395         status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
 396         if (status != CAM_REQ_CMP) {
 397                 xpt_print(path, "%sable lun CCB rejected, status %#x\n",
 398                     enable ? "en" : "dis", status);
 399         }
 400         return (status);
 401 }
 402
 403 /* Enable target mode on a LUN, given its path */
 404 static cam_status
 405 targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
 406            int grp7_len)
 407 {
 408         struct cam_periph *periph;
 409         struct ccb_pathinq cpi;
 410         cam_status         status;
 411
 412         if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
 413                 return (CAM_LUN_ALRDY_ENA);
 414
 415         /* Make sure SIM supports target mode */
 416         xpt_setup_ccb(&cpi.ccb_h, path, /*priority*/1);
 417         cpi.ccb_h.func_code = XPT_PATH_INQ;
 418         xpt_action((union ccb *)&cpi);
 419         status = cpi.ccb_h.status & CAM_STATUS_MASK;
 420         if (status != CAM_REQ_CMP) {
 421                 kprintf("pathinq failed, status %#x\n", status);
 422                 goto enable_fail;
 423         }
 424         if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
 425                 kprintf("controller does not support target mode\n");
 426                 status = CAM_FUNC_NOTAVAIL;
 427                 goto enable_fail;
 428         }
 429
 430         /* Destroy any periph on our path if it is disabled */
 431         periph = cam_periph_find(path, "targ");
 432         if (periph != NULL) {
 433                 struct targ_softc *del_softc;
 434
 435                 del_softc = (struct targ_softc *)periph->softc;
 436                 if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 437                         cam_periph_invalidate(del_softc->periph);
 438                         del_softc->periph = NULL;
 439                 } else {
 440                         kprintf("Requested path still in use by targ%d\n",
 441                                periph->unit_number);
 442                         status = CAM_LUN_ALRDY_ENA;
 443                         goto enable_fail;
 444                 }
 445         }
 446
 447         /* Create a periph instance attached to this path */
 448         status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
 449                         "targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
 450         if (status != CAM_REQ_CMP) {
 451                 kprintf("cam_periph_alloc failed, status %#x\n", status);
 452                 goto enable_fail;
 453         }
 454
 455         /* Ensure that the periph now exists. */
 456         if (cam_periph_find(path, "targ") == NULL) {
 457                 panic("targenable: succeeded but no periph?");
 458                 /* NOTREACHED */
 459         }
 460
 461         /* Send the enable lun message */
 462         status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
 463         if (status != CAM_REQ_CMP) {
 464                 kprintf("enable lun failed, status %#x\n", status);
 465                 goto enable_fail;
 466         }
 467         softc->state |= TARG_STATE_LUN_ENABLED;
 468
 469 enable_fail:
 470         return (status);
 471 }
 472
 473 /* Disable this softc's target instance if enabled */
 474 static cam_status
 475 targdisable(struct targ_softc *softc)
 476 {
 477         cam_status status;
 478
 479         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
 480                 return (CAM_REQ_CMP);
 481
 482         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
 483
 484         /* Abort any ccbs pending on the controller */
 485         crit_enter();
 486         abort_all_pending(softc);
 487         crit_exit();
 488
 489         /* Disable this lun */
 490         status = targendislun(softc->path, /*enable*/0,
 491                               /*grp6_len*/0, /*grp7_len*/0);
 492         if (status == CAM_REQ_CMP)
 493                 softc->state &= ~TARG_STATE_LUN_ENABLED;
 494         else
 495                 kprintf("Disable lun failed, status %#x\n", status);
 496
 497         return (status);
 498 }
 499
 500 /* Initialize a periph (called from cam_periph_alloc) */
 501 static cam_status
 502 targctor(struct cam_periph *periph, void *arg)
 503 {
 504         struct targ_softc *softc;
 505
 506         /* Store pointer to softc for periph-driven routines */
 507         softc = (struct targ_softc *)arg;
 508         periph->softc = softc;
 509         softc->periph = periph;
 510         softc->path = periph->path;
 511         return (CAM_REQ_CMP);
 512 }
 513
 514 static void
 515 targdtor(struct cam_periph *periph)
 516 {
 517         struct targ_softc     *softc;
 518         struct ccb_hdr        *ccb_h;
 519         struct targ_cmd_descr *descr;
 520
 521         softc = (struct targ_softc *)periph->softc;
 522
 523         /*
 524          * targdisable() aborts CCBs back to the user and leaves them
 525          * on user_ccb_queue and abort_queue in case the user is still
 526          * interested in them.  We free them now.
 527          */
 528         while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
 529                 TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
 530                 targfreeccb(softc, (union ccb *)ccb_h);
 531         }
 532         while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
 533                 TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
 534                 FREE(descr, M_TARG);
 535         }
 536
 537         softc->periph = NULL;
 538         softc->path = NULL;
 539         periph->softc = NULL;
 540 }
 541
 542 /* Receive CCBs from user mode proc and send them to the HBA */
 543 static int
 544 targwrite(struct dev_write_args *ap)
 545 {
 546         struct uio *uio = ap->a_uio;
 547         union ccb *user_ccb;
 548         struct targ_softc *softc;
 549         struct targ_cmd_descr *descr;
 550         int write_len, error;
 551         int func_code, priority;
 552
 553         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 554         write_len = error = 0;
 555         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 556                   ("write - uio_resid %zu\n", uio->uio_resid));
 557         while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
 558                 union ccb *ccb;
 559
 560                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 561                 if (error != 0) {
 562                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 563                                   ("write - uiomove failed (%d)\n", error));
 564                         break;
 565                 }
 566                 priority = fuword(&user_ccb->ccb_h.pinfo.priority);
 567                 if (priority == -1) {
 568                         error = EINVAL;
 569                         break;
 570                 }
 571                 func_code = fuword(&user_ccb->ccb_h.func_code);
 572                 switch (func_code) {
 573                 case XPT_ACCEPT_TARGET_IO:
 574                 case XPT_IMMED_NOTIFY:
 575                         cam_periph_lock(softc->periph);
 576                         ccb = targgetccb(softc, func_code, priority);
 577                         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 578                         descr->user_ccb = user_ccb;
 579                         descr->func_code = func_code;
 580                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 581                                   ("Sent ATIO/INOT (%p)\n", user_ccb));
 582                         xpt_action(ccb);
 583                         TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
 584                                           &ccb->ccb_h,
 585                                           periph_links.tqe);
 586                         cam_periph_unlock(softc->periph);
 587                         break;
 588                 default:
 589                         cam_periph_lock(softc->periph);
 590                         if ((func_code & XPT_FC_QUEUED) != 0) {
 591                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 592                                           ("Sending queued ccb %#x (%p)\n",
 593                                           func_code, user_ccb));
 594                                 descr = targgetdescr(softc);
 595                                 descr->user_ccb = user_ccb;
 596                                 descr->priority = priority;
 597                                 descr->func_code = func_code;
 598                                 crit_enter();
 599                                 TAILQ_INSERT_TAIL(&softc->work_queue,
 600                                                   descr, tqe);
 601                                 crit_exit();
 602                                 xpt_schedule(softc->periph, priority);
 603                         } else {
 604                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 605                                           ("Sending inline ccb %#x (%p)\n",
 606                                           func_code, user_ccb));
 607                                 ccb = targgetccb(softc, func_code, priority);
 608                                 descr = (struct targ_cmd_descr *)
 609                                          ccb->ccb_h.targ_descr;
 610                                 descr->user_ccb = user_ccb;
 611                                 descr->priority = priority;
 612                                 descr->func_code = func_code;
 613                                 if (targusermerge(softc, descr, ccb) != EFAULT)
 614                                         targsendccb(softc, ccb, descr);
 615                                 targreturnccb(softc, ccb);
 616                         }
 617                         cam_periph_unlock(softc->periph);
 618                         break;
 619                 }
 620                 write_len += sizeof(user_ccb);
 621         }
 622
 623         /*
 624          * If we've successfully taken in some amount of
 625          * data, return success for that data first.  If
 626          * an error is persistent, it will be reported
 627          * on the next write.
 628          */
 629         if (error != 0 && write_len == 0)
 630                 return (error);
 631         if (write_len == 0 && uio->uio_resid != 0)
 632                 return (ENOSPC);
 633         return (0);
 634 }
 635
 636 /* Process requests (descrs) via the periph-supplied CCBs */
 637 static void
 638 targstart(struct cam_periph *periph, union ccb *start_ccb)
 639 {
 640         struct targ_softc *softc;
 641         struct targ_cmd_descr *descr, *next_descr;
 642         int error;
 643
 644         softc = (struct targ_softc *)periph->softc;
 645         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
 646
 647         crit_enter();
 648         descr = TAILQ_FIRST(&softc->work_queue);
 649         if (descr == NULL) {
 650                 crit_exit();
 651                 xpt_release_ccb(start_ccb);
 652         } else {
 653                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
 654                 next_descr = TAILQ_FIRST(&softc->work_queue);
 655                 crit_exit();
 656
 657                 /* Initiate a transaction using the descr and supplied CCB */
 658                 error = targusermerge(softc, descr, start_ccb);
 659                 if (error == 0)
 660                         error = targsendccb(softc, start_ccb, descr);
 661                 if (error != 0) {
 662                         xpt_print(periph->path,
 663                             "targsendccb failed, err %d\n", error);
 664                         xpt_release_ccb(start_ccb);
 665                         suword(&descr->user_ccb->ccb_h.status,
 666                                CAM_REQ_CMP_ERR);
 667                         crit_enter();
 668                         TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
 669                         crit_exit();
 670                         notify_user(softc);
 671                 }
 672
 673                 /* If we have more work to do, stay scheduled */
 674                 if (next_descr != NULL)
 675                         xpt_schedule(periph, next_descr->priority);
 676         }
 677 }
 678
 679 static int
 680 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
 681               union ccb *ccb)
 682 {
 683         struct ccb_hdr *u_ccbh, *k_ccbh;
 684         size_t ccb_len;
 685         int error;
 686
 687         u_ccbh = &descr->user_ccb->ccb_h;
 688         k_ccbh = &ccb->ccb_h;
 689
 690         /*
 691          * There are some fields in the CCB header that need to be
 692          * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
 693          */
 694         xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
 695         k_ccbh->retry_count = fuword(&u_ccbh->retry_count);
 696         k_ccbh->func_code = descr->func_code;
 697         k_ccbh->flags = fuword(&u_ccbh->flags);
 698         k_ccbh->timeout = fuword(&u_ccbh->timeout);
 699         ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
 700         error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
 701         if (error != 0) {
 702                 k_ccbh->status = CAM_REQ_CMP_ERR;
 703                 return (error);
 704         }
 705
 706         /* Translate usermode abort_ccb pointer to its kernel counterpart */
 707         if (k_ccbh->func_code == XPT_ABORT) {
 708                 struct ccb_abort *cab;
 709                 struct ccb_hdr *ccb_h;
 710
 711                 cab = (struct ccb_abort *)ccb;
 712                 crit_enter();
 713                 TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
 714                     periph_links.tqe) {
 715                         struct targ_cmd_descr *ab_descr;
 716
 717                         ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 718                         if (ab_descr->user_ccb == cab->abort_ccb) {
 719                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 720                                           ("Changing abort for %p to %p\n",
 721                                           cab->abort_ccb, ccb_h));
 722                                 cab->abort_ccb = (union ccb *)ccb_h;
 723                                 break;
 724                         }
 725                 }
 726                 crit_exit();
 727                 /* CCB not found, set appropriate status */
 728                 if (ccb_h == NULL) {
 729                         k_ccbh->status = CAM_PATH_INVALID;
 730                         error = ESRCH;
 731                 }
 732         }
 733
 734         return (error);
 735 }
 736
 737 /* Build and send a kernel CCB formed from descr->user_ccb */
 738 static int
 739 targsendccb(struct targ_softc *softc, union ccb *ccb,
 740             struct targ_cmd_descr *descr)
 741 {
 742         struct cam_periph_map_info *mapinfo;
 743         struct ccb_hdr *ccb_h;
 744         int error;
 745
 746         ccb_h = &ccb->ccb_h;
 747         mapinfo = &descr->mapinfo;
 748         mapinfo->num_bufs_used = 0;
 749
 750         /*
 751          * There's no way for the user to have a completion
 752          * function, so we put our own completion function in here.
 753          * We also stash in a reference to our descriptor so targreturnccb()
 754          * can find our mapping info.
 755          */
 756         ccb_h->cbfcnp = targdone;
 757         ccb_h->targ_descr = descr;
 758
 759         /*
 760          * We only attempt to map the user memory into kernel space
 761          * if they haven't passed in a physical memory pointer,
 762          * and if there is actually an I/O operation to perform.
 763          * Right now cam_periph_mapmem() only supports SCSI and device
 764          * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
 765          * there's actually data to map.  cam_periph_mapmem() will do the
 766          * right thing, even if there isn't data to map, but since CCBs
 767          * without data are a reasonably common occurance (e.g. test unit
 768          * ready), it will save a few cycles if we check for it here.
 769          */
 770         if (((ccb_h->flags & CAM_DATA_PHYS) == 0)
 771          && (((ccb_h->func_code == XPT_CONT_TARGET_IO)
 772             && ((ccb_h->flags & CAM_DIR_MASK) != CAM_DIR_NONE))
 773           || (ccb_h->func_code == XPT_DEV_MATCH))) {
 774
 775                 error = cam_periph_mapmem(ccb, mapinfo);
 776
 777                 /*
 778                  * cam_periph_mapmem returned an error, we can't continue.
 779                  * Return the error to the user.
 780                  */
 781                 if (error) {
 782                         ccb_h->status = CAM_REQ_CMP_ERR;
 783                         mapinfo->num_bufs_used = 0;
 784                         return (error);
 785                 }
 786         }
 787
 788         /*
 789          * Once queued on the pending CCB list, this CCB will be protected
 790          * by our error recovery handler.
 791          */
 792         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
 793         if (XPT_FC_IS_QUEUED(ccb)) {
 794                 crit_enter();
 795                 TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
 796                                   periph_links.tqe);
 797                 crit_exit();
 798         }
 799         xpt_action(ccb);
 800
 801         return (0);
 802 }
 803
 804 /* Completion routine for CCBs (called in a critical section) */
 805 static void
 806 targdone(struct cam_periph *periph, union ccb *done_ccb)
 807 {
 808         struct targ_softc *softc;
 809         cam_status status;
 810
 811         CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
 812         softc = (struct targ_softc *)periph->softc;
 813         TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
 814                      periph_links.tqe);
 815         status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
 816
 817         /* If we're no longer enabled, throw away CCB */
 818         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 819                 targfreeccb(softc, done_ccb);
 820                 return;
 821         }
 822         /* abort_all_pending() waits for pending queue to be empty */
 823         if (TAILQ_EMPTY(&softc->pending_ccb_queue))
 824                 wakeup(&softc->pending_ccb_queue);
 825
 826         switch (done_ccb->ccb_h.func_code) {
 827         /* All FC_*_QUEUED CCBs go back to userland */
 828         case XPT_IMMED_NOTIFY:
 829         case XPT_ACCEPT_TARGET_IO:
 830         case XPT_CONT_TARGET_IO:
 831                 TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
 832                                   periph_links.tqe);
 833                 notify_user(softc);
 834                 break;
 835         default:
 836                 panic("targdone: impossible xpt opcode %#x",
 837                       done_ccb->ccb_h.func_code);
 838                 /* NOTREACHED */
 839         }
 840 }
 841
 842 /* Return CCBs to the user from the user queue and abort queue */
 843 static int
 844 targread(struct dev_read_args *ap)
 845 {
 846         struct uio *uio = ap->a_uio;
 847         struct descr_queue      *abort_queue;
 848         struct targ_cmd_descr   *user_descr;
 849         struct targ_softc       *softc;
 850         struct ccb_queue  *user_queue;
 851         struct ccb_hdr    *ccb_h;
 852         union  ccb        *user_ccb;
 853         int                read_len, error;
 854
 855         error = 0;
 856         read_len = 0;
 857         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 858         user_queue = &softc->user_ccb_queue;
 859         abort_queue = &softc->abort_queue;
 860         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
 861
 862         /* If no data is available, wait or return immediately */
 863         cam_periph_lock(softc->periph);
 864         ccb_h = TAILQ_FIRST(user_queue);
 865         user_descr = TAILQ_FIRST(abort_queue);
 866         while (ccb_h == NULL && user_descr == NULL) {
 867                 if ((ap->a_ioflag & IO_NDELAY) == 0) {
 868                         error = sim_lock_sleep(user_queue, PCATCH, "targrd", 0,
 869                                                softc->periph->sim->lock);
 870                         ccb_h = TAILQ_FIRST(user_queue);
 871                         user_descr = TAILQ_FIRST(abort_queue);
 872                         if (error != 0) {
 873                                 if (error == ERESTART) {
 874                                         continue;
 875                                 } else {
 876                                         goto read_fail;
 877                                 }
 878                         }
 879                 } else {
 880                         cam_periph_unlock(softc->periph);
 881                         return (EAGAIN);
 882                 }
 883         }
 884
 885         /* Data is available so fill the user's buffer */
 886         while (ccb_h != NULL) {
 887                 struct targ_cmd_descr *descr;
 888
 889                 if (uio->uio_resid < sizeof(user_ccb))
 890                         break;
 891                 TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
 892                 descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 893                 user_ccb = descr->user_ccb;
 894                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 895                           ("targread ccb %p (%p)\n", ccb_h, user_ccb));
 896                 error = targreturnccb(softc, (union ccb *)ccb_h);
 897                 if (error != 0)
 898                         goto read_fail;
 899                 cam_periph_unlock(softc->periph);
 900                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 901                 cam_periph_lock(softc->periph);
 902                 if (error != 0)
 903                         goto read_fail;
 904                 read_len += sizeof(user_ccb);
 905
 906                 ccb_h = TAILQ_FIRST(user_queue);
 907         }
 908
 909         /* Flush out any aborted descriptors */
 910         while (user_descr != NULL) {
 911                 if (uio->uio_resid < sizeof(user_ccb))
 912                         break;
 913                 TAILQ_REMOVE(abort_queue, user_descr, tqe);
 914                 user_ccb = user_descr->user_ccb;
 915                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 916                           ("targread aborted descr %p (%p)\n",
 917                           user_descr, user_ccb));
 918                 suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
 919                 cam_periph_unlock(softc->periph);
 920                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 921                 cam_periph_lock(softc->periph);
 922                 if (error != 0)
 923                         goto read_fail;
 924                 read_len += sizeof(user_ccb);
 925
 926                 user_descr = TAILQ_FIRST(abort_queue);
 927         }
 928
 929         /*
 930          * If we've successfully read some amount of data, don't report an
 931          * error.  If the error is persistent, it will be reported on the
 932          * next read().
 933          */
 934         if (read_len == 0 && uio->uio_resid != 0)
 935                 error = ENOSPC;
 936
 937 read_fail:
 938         cam_periph_unlock(softc->periph);
 939         return (error);
 940 }
 941
 942 /* Copy completed ccb back to the user */
 943 static int
 944 targreturnccb(struct targ_softc *softc, union ccb *ccb)
 945 {
 946         struct targ_cmd_descr *descr;
 947         struct ccb_hdr *u_ccbh;
 948         size_t ccb_len;
 949         int error;
 950
 951         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
 952         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 953         u_ccbh = &descr->user_ccb->ccb_h;
 954
 955         /* Copy out the central portion of the ccb_hdr */
 956         copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
 957                 offsetof(struct ccb_hdr, periph_priv) -
 958                 offsetof(struct ccb_hdr, retry_count));
 959
 960         /* Copy out the rest of the ccb (after the ccb_hdr) */
 961         ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
 962         if (descr->mapinfo.num_bufs_used != 0)
 963                 cam_periph_unmapmem(ccb, &descr->mapinfo);
 964         error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
 965         if (error != 0) {
 966                 xpt_print(softc->path,
 967                     "targreturnccb - CCB copyout failed (%d)\n", error);
 968         }
 969         /* Free CCB or send back to devq. */
 970         targfreeccb(softc, ccb);
 971
 972         return (error);
 973 }
 974
 975 static union ccb *
 976 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
 977 {
 978         union ccb *ccb;
 979         int ccb_len;
 980
 981         ccb_len = targccblen(type);
 982         MALLOC(ccb, union ccb *, ccb_len, M_TARG, M_INTWAIT);
 983         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
 984
 985         xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
 986         ccb->ccb_h.func_code = type;
 987         ccb->ccb_h.cbfcnp = targdone;
 988         ccb->ccb_h.targ_descr = targgetdescr(softc);
 989         return (ccb);
 990 }
 991
 992 static void
 993 targfreeccb(struct targ_softc *softc, union ccb *ccb)
 994 {
 995         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
 996                         ccb->ccb_h.targ_descr));
 997         FREE(ccb->ccb_h.targ_descr, M_TARG);
 998
 999         switch (ccb->ccb_h.func_code) {
1000         case XPT_ACCEPT_TARGET_IO:
1001         case XPT_IMMED_NOTIFY:
1002                 CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
1003                 FREE(ccb, M_TARG);
1004                 break;
1005         default:
1006                 /* Send back CCB if we got it from the periph */
1007                 if (XPT_FC_IS_QUEUED(ccb)) {
1008                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
1009                                         ("returning queued ccb %p\n", ccb));
1010                         xpt_release_ccb(ccb);
1011                 } else {
1012                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
1013                                         ("freeing ccb %p\n", ccb));
1014                         FREE(ccb, M_TARG);
1015                 }
1016                 break;
1017         }
1018 }
1019
1020 static struct targ_cmd_descr *
1021 targgetdescr(struct targ_softc *softc)
1022 {
1023         struct targ_cmd_descr *descr;
1024
1025         MALLOC(descr, struct targ_cmd_descr *, sizeof(*descr),
1026                 M_TARG, M_INTWAIT);
1027         descr->mapinfo.num_bufs_used = 0;
1028         return (descr);
1029 }
1030
1031 static int
1032 targclone(struct dev_clone_args *ap)
1033 {
1034         int unit;
1035
1036         unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(targ), 0);
1037         ap->a_dev = make_only_dev(&targ_ops, unit, UID_ROOT, GID_WHEEL,
1038                                   0600, "targ%d", unit);
1039         return 0;
1040 }
1041
1042 static void
1043 targinit(void)
1044 {
1045         make_autoclone_dev(&targ_ops, &DEVFS_CLONE_BITMAP(targ),
1046                 targclone, UID_ROOT, GID_WHEEL, 0600, "targ");
1047         /* XXX: need uninit or so? */
1048 }
1049
1050 static void
1051 targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
1052 {
1053         /* All events are handled in usermode by INOTs */
1054         panic("targasync() called, should be an INOT instead");
1055 }
1056
1057 /* Cancel all pending requests and CCBs awaiting work. */
1058 static void
1059 abort_all_pending(struct targ_softc *softc)
1060 {
1061         struct targ_cmd_descr   *descr;
1062         struct ccb_abort         cab;
1063         struct ccb_hdr          *ccb_h;
1064         struct cam_sim          *sim;
1065
1066         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1067
1068         /* First abort the descriptors awaiting resources */
1069         while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1070                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1071                           ("Aborting descr from workq %p\n", descr));
1072                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1073                 TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1074         }
1075
1076         /*
1077          * Then abort all pending CCBs.
1078          * targdone() will return the aborted CCB via user_ccb_queue
1079          */
1080         xpt_setup_ccb(&cab.ccb_h, softc->path, /*priority*/0);
1081         cab.ccb_h.func_code = XPT_ABORT;
1082         cab.ccb_h.status = CAM_REQ_CMP_ERR;
1083         TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1084                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1085                           ("Aborting pending CCB %p\n", ccb_h));
1086                 cab.abort_ccb = (union ccb *)ccb_h;
1087                 xpt_action((union ccb *)&cab);
1088                 if (cab.ccb_h.status != CAM_REQ_CMP) {
1089                         xpt_print(cab.ccb_h.path,
1090                             "Unable to abort CCB, status %#x\n",
1091                             cab.ccb_h.status);
1092                 }
1093         }
1094
1095         /* If we aborted at least one pending CCB ok, wait for it. */
1096         if (cab.ccb_h.status == CAM_REQ_CMP) {
1097                 sim = xpt_path_sim(softc->path);
1098                 sim_lock_sleep(&softc->pending_ccb_queue, PCATCH, "tgabrt", 0,
1099                                sim->lock);
1100         }
1101
1102         /* If we aborted anything from the work queue, wakeup user. */
1103         if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1104          || !TAILQ_EMPTY(&softc->abort_queue))
1105                 notify_user(softc);
1106 }
1107
1108 /* Notify the user that data is ready */
1109 static void
1110 notify_user(struct targ_softc *softc)
1111 {
1112         /*
1113          * Notify users sleeping via poll(), kqueue(), and
1114          * blocking read().
1115          */
1116         KNOTE(&softc->read_kq.ki_note, 0);
1117         wakeup(&softc->user_ccb_queue);
1118 }
1119
1120 /* Convert CAM status to errno values */
1121 static int
1122 targcamstatus(cam_status status)
1123 {
1124         switch (status & CAM_STATUS_MASK) {
1125         case CAM_REQ_CMP:       /* CCB request completed without error */
1126                 return (0);
1127         case CAM_REQ_INPROG:    /* CCB request is in progress */
1128                 return (EINPROGRESS);
1129         case CAM_REQ_CMP_ERR:   /* CCB request completed with an error */
1130                 return (EIO);
1131         case CAM_PROVIDE_FAIL:  /* Unable to provide requested capability */
1132                 return (ENOTTY);
1133         case CAM_FUNC_NOTAVAIL: /* The requested function is not available */
1134                 return (ENOTSUP);
1135         case CAM_LUN_ALRDY_ENA: /* LUN is already enabled for target mode */
1136                 return (EADDRINUSE);
1137         case CAM_PATH_INVALID:  /* Supplied Path ID is invalid */
1138         case CAM_DEV_NOT_THERE: /* SCSI Device Not Installed/there */
1139                 return (ENOENT);
1140         case CAM_REQ_ABORTED:   /* CCB request aborted by the host */
1141                 return (ECANCELED);
1142         case CAM_CMD_TIMEOUT:   /* Command timeout */
1143                 return (ETIMEDOUT);
1144         case CAM_REQUEUE_REQ:   /* Requeue to preserve transaction ordering */
1145                 return (EAGAIN);
1146         case CAM_REQ_INVALID:   /* CCB request was invalid */
1147                 return (EINVAL);
1148         case CAM_RESRC_UNAVAIL: /* Resource Unavailable */
1149                 return (ENOMEM);
1150         case CAM_BUSY:          /* CAM subsytem is busy */
1151         case CAM_UA_ABORT:      /* Unable to abort CCB request */
1152                 return (EBUSY);
1153         default:
1154                 return (ENXIO);
1155         }
1156 }
1157
1158 static size_t
1159 targccblen(xpt_opcode func_code)
1160 {
1161         int len;
1162
1163         /* Codes we expect to see as a target */
1164         switch (func_code) {
1165         case XPT_CONT_TARGET_IO:
1166         case XPT_SCSI_IO:
1167                 len = sizeof(struct ccb_scsiio);
1168                 break;
1169         case XPT_ACCEPT_TARGET_IO:
1170                 len = sizeof(struct ccb_accept_tio);
1171                 break;
1172         case XPT_IMMED_NOTIFY:
1173                 len = sizeof(struct ccb_immed_notify);
1174                 break;
1175         case XPT_REL_SIMQ:
1176                 len = sizeof(struct ccb_relsim);
1177                 break;
1178         case XPT_PATH_INQ:
1179                 len = sizeof(struct ccb_pathinq);
1180                 break;
1181         case XPT_DEBUG:
1182                 len = sizeof(struct ccb_debug);
1183                 break;
1184         case XPT_ABORT:
1185                 len = sizeof(struct ccb_abort);
1186                 break;
1187         case XPT_EN_LUN:
1188                 len = sizeof(struct ccb_en_lun);
1189                 break;
1190         default:
1191                 len = sizeof(union ccb);
1192                 break;
1193         }
1194
1195         return (len);
1196 }