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