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  * $DragonFly: src/sys/bus/cam/scsi/scsi_target.c,v 1.7 2004/03/15 02:27:56 dillon Exp $
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/conf.h>
  37 #include <sys/malloc.h>
  38 #include <sys/poll.h>
  39 #include <sys/vnode.h>
  40 #include <sys/devicestat.h>
  41
  42 #include "../cam.h"
  43 #include "../cam_ccb.h"
  44 #include "../cam_periph.h"
  45 #include "../cam_xpt_periph.h"
  46 #include "scsi_targetio.h"
  47
  48 /* Transaction information attached to each CCB sent by the user */
  49 struct targ_cmd_descr {
  50         struct cam_periph_map_info  mapinfo;
  51         TAILQ_ENTRY(targ_cmd_descr) tqe;
  52         union ccb *user_ccb;
  53         int        priority;
  54         int        func_code;
  55 };
  56
  57 /* Offset into the private CCB area for storing our descriptor */
  58 #define targ_descr      periph_priv.entries[1].ptr
  59
  60 TAILQ_HEAD(descr_queue, targ_cmd_descr);
  61
  62 typedef enum {
  63         TARG_STATE_RESV         = 0x00, /* Invalid state */
  64         TARG_STATE_OPENED       = 0x01, /* Device opened, softc initialized */
  65         TARG_STATE_LUN_ENABLED  = 0x02  /* Device enabled for a path */
  66 } targ_state;
  67
  68 /* Per-instance device software context */
  69 struct targ_softc {
  70         /* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
  71         struct ccb_queue         pending_ccb_queue;
  72
  73         /* Command descriptors awaiting CTIO resources from the XPT */
  74         struct descr_queue       work_queue;
  75
  76         /* Command descriptors that have been aborted back to the user. */
  77         struct descr_queue       abort_queue;
  78
  79         /*
  80          * Queue of CCBs that have been copied out to userland, but our
  81          * userland daemon has not yet seen.
  82          */
  83         struct ccb_queue         user_ccb_queue;
  84
  85         struct cam_periph       *periph;
  86         struct cam_path         *path;
  87         targ_state               state;
  88         struct selinfo           read_select;
  89         struct devstat           device_stats;
  90 };
  91
  92 static d_open_t         targopen;
  93 static d_close_t        targclose;
  94 static d_read_t         targread;
  95 static d_write_t        targwrite;
  96 static d_ioctl_t        targioctl;
  97 static d_poll_t         targpoll;
  98 static d_kqfilter_t     targkqfilter;
  99 static void             targreadfiltdetach(struct knote *kn);
 100 static int              targreadfilt(struct knote *kn, long hint);
 101 static struct filterops targread_filtops =
 102         { 1, NULL, targreadfiltdetach, targreadfilt };
 103
 104 #define TARG_CDEV_MAJOR 65
 105 static struct cdevsw targ_cdevsw = {
 106         /* name */      "targ",
 107         /* maj */       TARG_CDEV_MAJOR,
 108         /* flags */     D_KQFILTER,
 109         /* port */      NULL,
 110         /* autoq */     0,
 111
 112         /* open */      targopen,
 113         /* close */     targclose,
 114         /* read */      targread,
 115         /* write */     targwrite,
 116         /* ioctl */     targioctl,
 117         /* poll */      targpoll,
 118         /* mmap */      nommap,
 119         /* strategy */  nostrategy,
 120         /* dump */      nodump,
 121         /* psize */     nopsize,
 122         /* kqfilter */  targkqfilter
 123 };
 124
 125 static cam_status       targendislun(struct cam_path *path, int enable,
 126                                      int grp6_len, int grp7_len);
 127 static cam_status       targenable(struct targ_softc *softc,
 128                                    struct cam_path *path,
 129                                    int grp6_len, int grp7_len);
 130 static cam_status       targdisable(struct targ_softc *softc);
 131 static periph_ctor_t    targctor;
 132 static periph_dtor_t    targdtor;
 133 static periph_start_t   targstart;
 134 static int              targusermerge(struct targ_softc *softc,
 135                                       struct targ_cmd_descr *descr,
 136                                       union ccb *ccb);
 137 static int              targsendccb(struct targ_softc *softc, union ccb *ccb,
 138                                     struct targ_cmd_descr *descr);
 139 static void             targdone(struct cam_periph *periph,
 140                                  union  ccb *done_ccb);
 141 static int              targreturnccb(struct targ_softc *softc,
 142                                       union  ccb *ccb);
 143 static union ccb *      targgetccb(struct targ_softc *softc, xpt_opcode type,
 144                                    int priority);
 145 static void             targfreeccb(struct targ_softc *softc, union ccb *ccb);
 146 static struct targ_cmd_descr *
 147                         targgetdescr(struct targ_softc *softc);
 148 static periph_init_t    targinit;
 149 static void             targasync(void *callback_arg, u_int32_t code,
 150                                   struct cam_path *path, void *arg);
 151 static void             abort_all_pending(struct targ_softc *softc);
 152 static void             notify_user(struct targ_softc *softc);
 153 static int              targcamstatus(cam_status status);
 154 static size_t           targccblen(xpt_opcode func_code);
 155
 156 static struct periph_driver targdriver =
 157 {
 158         targinit, "targ",
 159         TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
 160 };
 161 DATA_SET(periphdriver_set, targdriver);
 162
 163 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
 164
 165 /* Create softc and initialize it. Only one proc can open each targ device. */
 166 static int
 167 targopen(dev_t dev, int flags, int fmt, struct proc *p)
 168 {
 169         struct targ_softc *softc;
 170
 171         if (dev->si_drv1 != 0) {
 172                 return (EBUSY);
 173         }
 174
 175         /* Mark device busy before any potentially blocking operations */
 176         dev->si_drv1 = (void *)~0;
 177
 178         /* Create the targ device, allocate its softc, initialize it */
 179         make_dev(&targ_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600,
 180                          "targ%d", lminor(dev));
 181         MALLOC(softc, struct targ_softc *, sizeof(*softc), M_TARG,
 182                M_INTWAIT | M_ZERO);
 183         dev->si_drv1 = softc;
 184         softc->state = TARG_STATE_OPENED;
 185         softc->periph = NULL;
 186         softc->path = NULL;
 187
 188         TAILQ_INIT(&softc->pending_ccb_queue);
 189         TAILQ_INIT(&softc->work_queue);
 190         TAILQ_INIT(&softc->abort_queue);
 191         TAILQ_INIT(&softc->user_ccb_queue);
 192
 193         return (0);
 194 }
 195
 196 /* Disable LUN if enabled and teardown softc */
 197 static int
 198 targclose(dev_t dev, int flag, int fmt, struct proc *p)
 199 {
 200         struct targ_softc     *softc;
 201         int    error;
 202
 203         softc = (struct targ_softc *)dev->si_drv1;
 204         error = targdisable(softc);
 205         if (error == CAM_REQ_CMP) {
 206                 dev->si_drv1 = 0;
 207                 if (softc->periph != NULL) {
 208                         cam_periph_invalidate(softc->periph);
 209                         softc->periph = NULL;
 210                 }
 211                 destroy_dev(dev);
 212                 FREE(softc, M_TARG);
 213         }
 214         return (error);
 215 }
 216
 217 /* Enable/disable LUNs, set debugging level */
 218 static int
 219 targioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 220 {
 221         struct targ_softc *softc;
 222         cam_status         status;
 223
 224         softc = (struct targ_softc *)dev->si_drv1;
 225
 226         switch (cmd) {
 227         case TARGIOCENABLE:
 228         {
 229                 struct ioc_enable_lun   *new_lun;
 230                 struct cam_path         *path;
 231
 232                 new_lun = (struct ioc_enable_lun *)addr;
 233                 status = xpt_create_path(&path, /*periph*/NULL,
 234                                          new_lun->path_id,
 235                                          new_lun->target_id,
 236                                          new_lun->lun_id);
 237                 if (status != CAM_REQ_CMP) {
 238                         printf("Couldn't create path, status %#x\n", status);
 239                         break;
 240                 }
 241                 status = targenable(softc, path, new_lun->grp6_len,
 242                                     new_lun->grp7_len);
 243                 xpt_free_path(path);
 244                 break;
 245         }
 246         case TARGIOCDISABLE:
 247                 status = targdisable(softc);
 248                 break;
 249         case TARGIOCDEBUG:
 250         {
 251 #ifdef  CAMDEBUG
 252                 struct ccb_debug cdbg;
 253
 254                 bzero(&cdbg, sizeof cdbg);
 255                 if (*((int *)addr) != 0)
 256                         cdbg.flags = CAM_DEBUG_PERIPH;
 257                 else
 258                         cdbg.flags = CAM_DEBUG_NONE;
 259                 xpt_setup_ccb(&cdbg.ccb_h, softc->path, /*priority*/0);
 260                 cdbg.ccb_h.func_code = XPT_DEBUG;
 261                 cdbg.ccb_h.cbfcnp = targdone;
 262
 263                 /* If no periph available, disallow debugging changes */
 264                 if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 265                         status = CAM_DEV_NOT_THERE;
 266                         break;
 267                 }
 268                 xpt_action((union ccb *)&cdbg);
 269                 status = cdbg.ccb_h.status & CAM_STATUS_MASK;
 270 #else
 271                 status = CAM_FUNC_NOTAVAIL;
 272 #endif
 273                 break;
 274         }
 275         default:
 276                 status = CAM_PROVIDE_FAIL;
 277                 break;
 278         }
 279
 280         return (targcamstatus(status));
 281 }
 282
 283 /* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
 284 static int
 285 targpoll(dev_t dev, int poll_events, struct proc *p)
 286 {
 287         struct targ_softc *softc;
 288         int     revents, s;
 289
 290         softc = (struct targ_softc *)dev->si_drv1;
 291
 292         /* Poll for write() is always ok. */
 293         revents = poll_events & (POLLOUT | POLLWRNORM);
 294         if ((poll_events & (POLLIN | POLLRDNORM)) != 0) {
 295                 s = splsoftcam();
 296                 /* Poll for read() depends on user and abort queues. */
 297                 if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
 298                     !TAILQ_EMPTY(&softc->abort_queue)) {
 299                         revents |= poll_events & (POLLIN | POLLRDNORM);
 300                 }
 301                 /* Only sleep if the user didn't poll for write. */
 302                 if (revents == 0)
 303                         selrecord(p, &softc->read_select);
 304                 splx(s);
 305         }
 306
 307         return (revents);
 308 }
 309
 310 static int
 311 targkqfilter(dev_t dev, struct knote *kn)
 312 {
 313         struct  targ_softc *softc;
 314         int     s;
 315
 316         softc = (struct targ_softc *)dev->si_drv1;
 317         kn->kn_hook = (caddr_t)softc;
 318         kn->kn_fop = &targread_filtops;
 319         s = splsoftcam();
 320         SLIST_INSERT_HEAD(&softc->read_select.si_note, kn, kn_selnext);
 321         splx(s);
 322         return (0);
 323 }
 324
 325 static void
 326 targreadfiltdetach(struct knote *kn)
 327 {
 328         struct  targ_softc *softc;
 329         int     s;
 330
 331         softc = (struct targ_softc *)kn->kn_hook;
 332         s = splsoftcam();
 333         SLIST_REMOVE(&softc->read_select.si_note, kn, knote, kn_selnext);
 334         splx(s);
 335 }
 336
 337 /* Notify the user's kqueue when the user queue or abort queue gets a CCB */
 338 static int
 339 targreadfilt(struct knote *kn, long hint)
 340 {
 341         struct targ_softc *softc;
 342         int     retval, s;
 343
 344         softc = (struct targ_softc *)kn->kn_hook;
 345         s = splsoftcam();
 346         retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
 347                  !TAILQ_EMPTY(&softc->abort_queue);
 348         splx(s);
 349         return (retval);
 350 }
 351
 352 /* Send the HBA the enable/disable message */
 353 static cam_status
 354 targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
 355 {
 356         struct ccb_en_lun en_ccb;
 357         cam_status        status;
 358
 359         /* Tell the lun to begin answering selects */
 360         xpt_setup_ccb(&en_ccb.ccb_h, path, /*priority*/1);
 361         en_ccb.ccb_h.func_code = XPT_EN_LUN;
 362         /* Don't need support for any vendor specific commands */
 363         en_ccb.grp6_len = grp6_len;
 364         en_ccb.grp7_len = grp7_len;
 365         en_ccb.enable = enable ? 1 : 0;
 366         xpt_action((union ccb *)&en_ccb);
 367         status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
 368         if (status != CAM_REQ_CMP) {
 369                 xpt_print_path(path);
 370                 printf("%sable lun CCB rejected, status %#x\n",
 371                        enable ? "en" : "dis", status);
 372         }
 373         return (status);
 374 }
 375
 376 /* Enable target mode on a LUN, given its path */
 377 static cam_status
 378 targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
 379            int grp7_len)
 380 {
 381         struct cam_periph *periph;
 382         struct ccb_pathinq cpi;
 383         cam_status         status;
 384
 385         if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
 386                 return (CAM_LUN_ALRDY_ENA);
 387
 388         /* Make sure SIM supports target mode */
 389         xpt_setup_ccb(&cpi.ccb_h, path, /*priority*/1);
 390         cpi.ccb_h.func_code = XPT_PATH_INQ;
 391         xpt_action((union ccb *)&cpi);
 392         status = cpi.ccb_h.status & CAM_STATUS_MASK;
 393         if (status != CAM_REQ_CMP) {
 394                 printf("pathinq failed, status %#x\n", status);
 395                 goto enable_fail;
 396         }
 397         if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
 398                 printf("controller does not support target mode\n");
 399                 status = CAM_FUNC_NOTAVAIL;
 400                 goto enable_fail;
 401         }
 402
 403         /* Destroy any periph on our path if it is disabled */
 404         periph = cam_periph_find(path, "targ");
 405         if (periph != NULL) {
 406                 struct targ_softc *del_softc;
 407
 408                 del_softc = (struct targ_softc *)periph->softc;
 409                 if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 410                         cam_periph_invalidate(del_softc->periph);
 411                         del_softc->periph = NULL;
 412                 } else {
 413                         printf("Requested path still in use by targ%d\n",
 414                                periph->unit_number);
 415                         status = CAM_LUN_ALRDY_ENA;
 416                         goto enable_fail;
 417                 }
 418         }
 419
 420         /* Create a periph instance attached to this path */
 421         status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
 422                         "targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
 423         if (status != CAM_REQ_CMP) {
 424                 printf("cam_periph_alloc failed, status %#x\n", status);
 425                 goto enable_fail;
 426         }
 427
 428         /* Ensure that the periph now exists. */
 429         if (cam_periph_find(path, "targ") == NULL) {
 430                 panic("targenable: succeeded but no periph?");
 431                 /* NOTREACHED */
 432         }
 433
 434         /* Send the enable lun message */
 435         status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
 436         if (status != CAM_REQ_CMP) {
 437                 printf("enable lun failed, status %#x\n", status);
 438                 goto enable_fail;
 439         }
 440         softc->state |= TARG_STATE_LUN_ENABLED;
 441
 442 enable_fail:
 443         return (status);
 444 }
 445
 446 /* Disable this softc's target instance if enabled */
 447 static cam_status
 448 targdisable(struct targ_softc *softc)
 449 {
 450         cam_status status;
 451         int s;
 452
 453         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
 454                 return (CAM_REQ_CMP);
 455
 456         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
 457
 458         /* Abort any ccbs pending on the controller */
 459         s = splcam();
 460         abort_all_pending(softc);
 461         splx(s);
 462
 463         /* Disable this lun */
 464         status = targendislun(softc->path, /*enable*/0,
 465                               /*grp6_len*/0, /*grp7_len*/0);
 466         if (status == CAM_REQ_CMP)
 467                 softc->state &= ~TARG_STATE_LUN_ENABLED;
 468         else
 469                 printf("Disable lun failed, status %#x\n", status);
 470
 471         return (status);
 472 }
 473
 474 /* Initialize a periph (called from cam_periph_alloc) */
 475 static cam_status
 476 targctor(struct cam_periph *periph, void *arg)
 477 {
 478         struct targ_softc *softc;
 479
 480         /* Store pointer to softc for periph-driven routines */
 481         softc = (struct targ_softc *)arg;
 482         periph->softc = softc;
 483         softc->periph = periph;
 484         softc->path = periph->path;
 485         return (CAM_REQ_CMP);
 486 }
 487
 488 static void
 489 targdtor(struct cam_periph *periph)
 490 {
 491         struct targ_softc     *softc;
 492         struct ccb_hdr        *ccb_h;
 493         struct targ_cmd_descr *descr;
 494
 495         softc = (struct targ_softc *)periph->softc;
 496
 497         /*
 498          * targdisable() aborts CCBs back to the user and leaves them
 499          * on user_ccb_queue and abort_queue in case the user is still
 500          * interested in them.  We free them now.
 501          */
 502         while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
 503                 TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
 504                 targfreeccb(softc, (union ccb *)ccb_h);
 505         }
 506         while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
 507                 TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
 508                 FREE(descr, M_TARG);
 509         }
 510
 511         softc->periph = NULL;
 512         softc->path = NULL;
 513         periph->softc = NULL;
 514 }
 515
 516 /* Receive CCBs from user mode proc and send them to the HBA */
 517 static int
 518 targwrite(dev_t dev, struct uio *uio, int ioflag)
 519 {
 520         union ccb *user_ccb;
 521         struct targ_softc *softc;
 522         struct targ_cmd_descr *descr;
 523         int write_len, error, s;
 524         int func_code, priority;
 525
 526         softc = (struct targ_softc *)dev->si_drv1;
 527         write_len = error = 0;
 528         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 529                   ("write - uio_resid %d\n", uio->uio_resid));
 530         while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
 531                 union ccb *ccb;
 532                 int error;
 533
 534                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 535                 if (error != 0) {
 536                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 537                                   ("write - uiomove failed (%d)\n", error));
 538                         break;
 539                 }
 540                 priority = fuword(&user_ccb->ccb_h.pinfo.priority);
 541                 if (priority == -1) {
 542                         error = EINVAL;
 543                         break;
 544                 }
 545                 func_code = fuword(&user_ccb->ccb_h.func_code);
 546                 switch (func_code) {
 547                 case XPT_ACCEPT_TARGET_IO:
 548                 case XPT_IMMED_NOTIFY:
 549                         ccb = targgetccb(softc, func_code, priority);
 550                         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 551                         descr->user_ccb = user_ccb;
 552                         descr->func_code = func_code;
 553                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 554                                   ("Sent ATIO/INOT (%p)\n", user_ccb));
 555                         xpt_action(ccb);
 556                         s = splsoftcam();
 557                         TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
 558                                           &ccb->ccb_h,
 559                                           periph_links.tqe);
 560                         splx(s);
 561                         break;
 562                 default:
 563                         if ((func_code & XPT_FC_QUEUED) != 0) {
 564                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 565                                           ("Sending queued ccb %#x (%p)\n",
 566                                           func_code, user_ccb));
 567                                 descr = targgetdescr(softc);
 568                                 descr->user_ccb = user_ccb;
 569                                 descr->priority = priority;
 570                                 descr->func_code = func_code;
 571                                 s = splsoftcam();
 572                                 TAILQ_INSERT_TAIL(&softc->work_queue,
 573                                                   descr, tqe);
 574                                 splx(s);
 575                                 xpt_schedule(softc->periph, priority);
 576                         } else {
 577                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 578                                           ("Sending inline ccb %#x (%p)\n",
 579                                           func_code, user_ccb));
 580                                 ccb = targgetccb(softc, func_code, priority);
 581                                 descr = (struct targ_cmd_descr *)
 582                                          ccb->ccb_h.targ_descr;
 583                                 descr->user_ccb = user_ccb;
 584                                 descr->priority = priority;
 585                                 descr->func_code = func_code;
 586                                 if (targusermerge(softc, descr, ccb) != EFAULT)
 587                                         targsendccb(softc, ccb, descr);
 588                                 targreturnccb(softc, ccb);
 589                         }
 590                         break;
 591                 }
 592                 write_len += sizeof(user_ccb);
 593         }
 594
 595         /*
 596          * If we've successfully taken in some amount of
 597          * data, return success for that data first.  If
 598          * an error is persistent, it will be reported
 599          * on the next write.
 600          */
 601         if (error != 0 && write_len == 0)
 602                 return (error);
 603         if (write_len == 0 && uio->uio_resid != 0)
 604                 return (ENOSPC);
 605         return (0);
 606 }
 607
 608 /* Process requests (descrs) via the periph-supplied CCBs */
 609 static void
 610 targstart(struct cam_periph *periph, union ccb *start_ccb)
 611 {
 612         struct targ_softc *softc;
 613         struct targ_cmd_descr *descr, *next_descr;
 614         int s, error;
 615
 616         softc = (struct targ_softc *)periph->softc;
 617         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
 618
 619         s = splsoftcam();
 620         descr = TAILQ_FIRST(&softc->work_queue);
 621         if (descr == NULL) {
 622                 splx(s);
 623                 xpt_release_ccb(start_ccb);
 624         } else {
 625                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
 626                 next_descr = TAILQ_FIRST(&softc->work_queue);
 627                 splx(s);
 628
 629                 /* Initiate a transaction using the descr and supplied CCB */
 630                 error = targusermerge(softc, descr, start_ccb);
 631                 if (error == 0)
 632                         error = targsendccb(softc, start_ccb, descr);
 633                 if (error != 0) {
 634                         xpt_print_path(periph->path);
 635                         printf("targsendccb failed, err %d\n", error);
 636                         xpt_release_ccb(start_ccb);
 637                         suword(&descr->user_ccb->ccb_h.status,
 638                                CAM_REQ_CMP_ERR);
 639                         s = splsoftcam();
 640                         TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
 641                         splx(s);
 642                         notify_user(softc);
 643                 }
 644
 645                 /* If we have more work to do, stay scheduled */
 646                 if (next_descr != NULL)
 647                         xpt_schedule(periph, next_descr->priority);
 648         }
 649 }
 650
 651 static int
 652 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
 653               union ccb *ccb)
 654 {
 655         struct ccb_hdr *u_ccbh, *k_ccbh;
 656         size_t ccb_len;
 657         int error;
 658
 659         u_ccbh = &descr->user_ccb->ccb_h;
 660         k_ccbh = &ccb->ccb_h;
 661
 662         /*
 663          * There are some fields in the CCB header that need to be
 664          * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
 665          */
 666         xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
 667         k_ccbh->retry_count = fuword(&u_ccbh->retry_count);
 668         k_ccbh->func_code = descr->func_code;
 669         k_ccbh->flags = fuword(&u_ccbh->flags);
 670         k_ccbh->timeout = fuword(&u_ccbh->timeout);
 671         ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
 672         error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
 673         if (error != 0) {
 674                 k_ccbh->status = CAM_REQ_CMP_ERR;
 675                 return (error);
 676         }
 677
 678         /* Translate usermode abort_ccb pointer to its kernel counterpart */
 679         if (k_ccbh->func_code == XPT_ABORT) {
 680                 struct ccb_abort *cab;
 681                 struct ccb_hdr *ccb_h;
 682                 int s;
 683
 684                 cab = (struct ccb_abort *)ccb;
 685                 s = splsoftcam();
 686                 TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
 687                     periph_links.tqe) {
 688                         struct targ_cmd_descr *ab_descr;
 689
 690                         ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 691                         if (ab_descr->user_ccb == cab->abort_ccb) {
 692                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 693                                           ("Changing abort for %p to %p\n",
 694                                           cab->abort_ccb, ccb_h));
 695                                 cab->abort_ccb = (union ccb *)ccb_h;
 696                                 break;
 697                         }
 698                 }
 699                 splx(s);
 700                 /* CCB not found, set appropriate status */
 701                 if (ccb_h == NULL) {
 702                         k_ccbh->status = CAM_PATH_INVALID;
 703                         error = ESRCH;
 704                 }
 705         }
 706
 707         return (error);
 708 }
 709
 710 /* Build and send a kernel CCB formed from descr->user_ccb */
 711 static int
 712 targsendccb(struct targ_softc *softc, union ccb *ccb,
 713             struct targ_cmd_descr *descr)
 714 {
 715         struct cam_periph_map_info *mapinfo;
 716         struct ccb_hdr *ccb_h;
 717         int error;
 718
 719         ccb_h = &ccb->ccb_h;
 720         mapinfo = &descr->mapinfo;
 721         mapinfo->num_bufs_used = 0;
 722
 723         /*
 724          * There's no way for the user to have a completion
 725          * function, so we put our own completion function in here.
 726          * We also stash in a reference to our descriptor so targreturnccb()
 727          * can find our mapping info.
 728          */
 729         ccb_h->cbfcnp = targdone;
 730         ccb_h->targ_descr = descr;
 731
 732         /*
 733          * We only attempt to map the user memory into kernel space
 734          * if they haven't passed in a physical memory pointer,
 735          * and if there is actually an I/O operation to perform.
 736          * Right now cam_periph_mapmem() only supports SCSI and device
 737          * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
 738          * there's actually data to map.  cam_periph_mapmem() will do the
 739          * right thing, even if there isn't data to map, but since CCBs
 740          * without data are a reasonably common occurance (e.g. test unit
 741          * ready), it will save a few cycles if we check for it here.
 742          */
 743         if (((ccb_h->flags & CAM_DATA_PHYS) == 0)
 744          && (((ccb_h->func_code == XPT_CONT_TARGET_IO)
 745             && ((ccb_h->flags & CAM_DIR_MASK) != CAM_DIR_NONE))
 746           || (ccb_h->func_code == XPT_DEV_MATCH))) {
 747
 748                 error = cam_periph_mapmem(ccb, mapinfo);
 749
 750                 /*
 751                  * cam_periph_mapmem returned an error, we can't continue.
 752                  * Return the error to the user.
 753                  */
 754                 if (error) {
 755                         ccb_h->status = CAM_REQ_CMP_ERR;
 756                         mapinfo->num_bufs_used = 0;
 757                         return (error);
 758                 }
 759         }
 760
 761         /*
 762          * Once queued on the pending CCB list, this CCB will be protected
 763          * by our error recovery handler.
 764          */
 765         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
 766         if (XPT_FC_IS_QUEUED(ccb)) {
 767                 int s;
 768
 769                 s = splsoftcam();
 770                 TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
 771                                   periph_links.tqe);
 772                 splx(s);
 773         }
 774         xpt_action(ccb);
 775
 776         return (0);
 777 }
 778
 779 /* Completion routine for CCBs (called at splsoftcam) */
 780 static void
 781 targdone(struct cam_periph *periph, union ccb *done_ccb)
 782 {
 783         struct targ_softc *softc;
 784         cam_status status;
 785
 786         CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
 787         softc = (struct targ_softc *)periph->softc;
 788         TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
 789                      periph_links.tqe);
 790         status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
 791
 792         /* If we're no longer enabled, throw away CCB */
 793         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 794                 targfreeccb(softc, done_ccb);
 795                 return;
 796         }
 797         /* abort_all_pending() waits for pending queue to be empty */
 798         if (TAILQ_EMPTY(&softc->pending_ccb_queue))
 799                 wakeup(&softc->pending_ccb_queue);
 800
 801         switch (done_ccb->ccb_h.func_code) {
 802         /* All FC_*_QUEUED CCBs go back to userland */
 803         case XPT_IMMED_NOTIFY:
 804         case XPT_ACCEPT_TARGET_IO:
 805         case XPT_CONT_TARGET_IO:
 806                 TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
 807                                   periph_links.tqe);
 808                 notify_user(softc);
 809                 break;
 810         default:
 811                 panic("targdone: impossible xpt opcode %#x",
 812                       done_ccb->ccb_h.func_code);
 813                 /* NOTREACHED */
 814         }
 815 }
 816
 817 /* Return CCBs to the user from the user queue and abort queue */
 818 static int
 819 targread(dev_t dev, struct uio *uio, int ioflag)
 820 {
 821         struct descr_queue      *abort_queue;
 822         struct targ_cmd_descr   *user_descr;
 823         struct targ_softc       *softc;
 824         struct ccb_queue  *user_queue;
 825         struct ccb_hdr    *ccb_h;
 826         union  ccb        *user_ccb;
 827         int                read_len, error, s;
 828
 829         error = 0;
 830         read_len = 0;
 831         softc = (struct targ_softc *)dev->si_drv1;
 832         user_queue = &softc->user_ccb_queue;
 833         abort_queue = &softc->abort_queue;
 834         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
 835
 836         /* If no data is available, wait or return immediately */
 837         s = splsoftcam();
 838         ccb_h = TAILQ_FIRST(user_queue);
 839         user_descr = TAILQ_FIRST(abort_queue);
 840         while (ccb_h == NULL && user_descr == NULL) {
 841                 if ((ioflag & IO_NDELAY) == 0) {
 842                         error = tsleep(user_queue, PCATCH, "targrd", 0);
 843                         ccb_h = TAILQ_FIRST(user_queue);
 844                         user_descr = TAILQ_FIRST(abort_queue);
 845                         if (error != 0) {
 846                                 if (error == ERESTART) {
 847                                         continue;
 848                                 } else {
 849                                         splx(s);
 850                                         goto read_fail;
 851                                 }
 852                         }
 853                 } else {
 854                         splx(s);
 855                         return (EAGAIN);
 856                 }
 857         }
 858
 859         /* Data is available so fill the user's buffer */
 860         while (ccb_h != NULL) {
 861                 struct targ_cmd_descr *descr;
 862
 863                 if (uio->uio_resid < sizeof(user_ccb))
 864                         break;
 865                 TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
 866                 splx(s);
 867                 descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 868                 user_ccb = descr->user_ccb;
 869                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 870                           ("targread ccb %p (%p)\n", ccb_h, user_ccb));
 871                 error = targreturnccb(softc, (union ccb *)ccb_h);
 872                 if (error != 0)
 873                         goto read_fail;
 874                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 875                 if (error != 0)
 876                         goto read_fail;
 877                 read_len += sizeof(user_ccb);
 878
 879                 s = splsoftcam();
 880                 ccb_h = TAILQ_FIRST(user_queue);
 881         }
 882
 883         /* Flush out any aborted descriptors */
 884         while (user_descr != NULL) {
 885                 if (uio->uio_resid < sizeof(user_ccb))
 886                         break;
 887                 TAILQ_REMOVE(abort_queue, user_descr, tqe);
 888                 splx(s);
 889                 user_ccb = user_descr->user_ccb;
 890                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 891                           ("targread aborted descr %p (%p)\n",
 892                           user_descr, user_ccb));
 893                 suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
 894                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 895                 if (error != 0)
 896                         goto read_fail;
 897                 read_len += sizeof(user_ccb);
 898
 899                 s = splsoftcam();
 900                 user_descr = TAILQ_FIRST(abort_queue);
 901         }
 902         splx(s);
 903
 904         /*
 905          * If we've successfully read some amount of data, don't report an
 906          * error.  If the error is persistent, it will be reported on the
 907          * next read().
 908          */
 909         if (read_len == 0 && uio->uio_resid != 0)
 910                 error = ENOSPC;
 911
 912 read_fail:
 913         return (error);
 914 }
 915
 916 /* Copy completed ccb back to the user */
 917 static int
 918 targreturnccb(struct targ_softc *softc, union ccb *ccb)
 919 {
 920         struct targ_cmd_descr *descr;
 921         struct ccb_hdr *u_ccbh;
 922         size_t ccb_len;
 923         int error;
 924
 925         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
 926         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 927         u_ccbh = &descr->user_ccb->ccb_h;
 928
 929         /* Copy out the central portion of the ccb_hdr */
 930         copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
 931                 offsetof(struct ccb_hdr, periph_priv) -
 932                 offsetof(struct ccb_hdr, retry_count));
 933
 934         /* Copy out the rest of the ccb (after the ccb_hdr) */
 935         ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
 936         if (descr->mapinfo.num_bufs_used != 0)
 937                 cam_periph_unmapmem(ccb, &descr->mapinfo);
 938         error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
 939         if (error != 0) {
 940                 xpt_print_path(softc->path);
 941                 printf("targreturnccb - CCB copyout failed (%d)\n",
 942                        error);
 943         }
 944         /* Free CCB or send back to devq. */
 945         targfreeccb(softc, ccb);
 946
 947         return (error);
 948 }
 949
 950 static union ccb *
 951 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
 952 {
 953         union ccb *ccb;
 954         int ccb_len;
 955
 956         ccb_len = targccblen(type);
 957         MALLOC(ccb, union ccb *, ccb_len, M_TARG, M_INTWAIT);
 958         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
 959
 960         xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
 961         ccb->ccb_h.func_code = type;
 962         ccb->ccb_h.cbfcnp = targdone;
 963         ccb->ccb_h.targ_descr = targgetdescr(softc);
 964         return (ccb);
 965 }
 966
 967 static void
 968 targfreeccb(struct targ_softc *softc, union ccb *ccb)
 969 {
 970         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
 971                         ccb->ccb_h.targ_descr));
 972         FREE(ccb->ccb_h.targ_descr, M_TARG);
 973
 974         switch (ccb->ccb_h.func_code) {
 975         case XPT_ACCEPT_TARGET_IO:
 976         case XPT_IMMED_NOTIFY:
 977                 CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
 978                 FREE(ccb, M_TARG);
 979                 break;
 980         default:
 981                 /* Send back CCB if we got it from the periph */
 982                 if (XPT_FC_IS_QUEUED(ccb)) {
 983                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
 984                                         ("returning queued ccb %p\n", ccb));
 985                         xpt_release_ccb(ccb);
 986                 } else {
 987                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
 988                                         ("freeing ccb %p\n", ccb));
 989                         FREE(ccb, M_TARG);
 990                 }
 991                 break;
 992         }
 993 }
 994
 995 static struct targ_cmd_descr *
 996 targgetdescr(struct targ_softc *softc)
 997 {
 998         struct targ_cmd_descr *descr;
 999
1000         MALLOC(descr, struct targ_cmd_descr *, sizeof(*descr),
1001                 M_TARG, M_INTWAIT);
1002         descr->mapinfo.num_bufs_used = 0;
1003         return (descr);
1004 }
1005
1006 static void
1007 targinit(void)
1008 {
1009         cdevsw_add(&targ_cdevsw);
1010 }
1011
1012 static void
1013 targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
1014 {
1015         /* All events are handled in usermode by INOTs */
1016         panic("targasync() called, should be an INOT instead");
1017 }
1018
1019 /* Cancel all pending requests and CCBs awaiting work. */
1020 static void
1021 abort_all_pending(struct targ_softc *softc)
1022 {
1023         struct targ_cmd_descr   *descr;
1024         struct ccb_abort         cab;
1025         struct ccb_hdr          *ccb_h;
1026
1027         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1028
1029         /* First abort the descriptors awaiting resources */
1030         while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1031                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1032                           ("Aborting descr from workq %p\n", descr));
1033                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1034                 TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1035         }
1036
1037         /*
1038          * Then abort all pending CCBs.
1039          * targdone() will return the aborted CCB via user_ccb_queue
1040          */
1041         xpt_setup_ccb(&cab.ccb_h, softc->path, /*priority*/0);
1042         cab.ccb_h.func_code = XPT_ABORT;
1043         cab.ccb_h.status = CAM_REQ_CMP_ERR;
1044         TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1045                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1046                           ("Aborting pending CCB %p\n", ccb_h));
1047                 cab.abort_ccb = (union ccb *)ccb_h;
1048                 xpt_action((union ccb *)&cab);
1049                 if (cab.ccb_h.status != CAM_REQ_CMP) {
1050                         xpt_print_path(cab.ccb_h.path);
1051                         printf("Unable to abort CCB, status %#x\n",
1052                                cab.ccb_h.status);
1053                 }
1054         }
1055
1056         /* If we aborted at least one pending CCB ok, wait for it. */
1057         if (cab.ccb_h.status == CAM_REQ_CMP) {
1058                 tsleep(&softc->pending_ccb_queue, PCATCH, "tgabrt", 0);
1059         }
1060
1061         /* If we aborted anything from the work queue, wakeup user. */
1062         if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1063          || !TAILQ_EMPTY(&softc->abort_queue))
1064                 notify_user(softc);
1065 }
1066
1067 /* Notify the user that data is ready */
1068 static void
1069 notify_user(struct targ_softc *softc)
1070 {
1071         /*
1072          * Notify users sleeping via poll(), kqueue(), and
1073          * blocking read().
1074          */
1075         selwakeup(&softc->read_select);
1076         KNOTE(&softc->read_select.si_note, 0);
1077         wakeup(&softc->user_ccb_queue);
1078 }
1079
1080 /* Convert CAM status to errno values */
1081 static int
1082 targcamstatus(cam_status status)
1083 {
1084         switch (status & CAM_STATUS_MASK) {
1085         case CAM_REQ_CMP:       /* CCB request completed without error */
1086                 return (0);
1087         case CAM_REQ_INPROG:    /* CCB request is in progress */
1088                 return (EINPROGRESS);
1089         case CAM_REQ_CMP_ERR:   /* CCB request completed with an error */
1090                 return (EIO);
1091         case CAM_PROVIDE_FAIL:  /* Unable to provide requested capability */
1092                 return (ENOTTY);
1093         case CAM_FUNC_NOTAVAIL: /* The requested function is not available */
1094                 return (ENOTSUP);
1095         case CAM_LUN_ALRDY_ENA: /* LUN is already enabled for target mode */
1096                 return (EADDRINUSE);
1097         case CAM_PATH_INVALID:  /* Supplied Path ID is invalid */
1098         case CAM_DEV_NOT_THERE: /* SCSI Device Not Installed/there */
1099                 return (ENOENT);
1100         case CAM_REQ_ABORTED:   /* CCB request aborted by the host */
1101                 return (ECANCELED);
1102         case CAM_CMD_TIMEOUT:   /* Command timeout */
1103                 return (ETIMEDOUT);
1104         case CAM_REQUEUE_REQ:   /* Requeue to preserve transaction ordering */
1105                 return (EAGAIN);
1106         case CAM_REQ_INVALID:   /* CCB request was invalid */
1107                 return (EINVAL);
1108         case CAM_RESRC_UNAVAIL: /* Resource Unavailable */
1109                 return (ENOMEM);
1110         case CAM_BUSY:          /* CAM subsytem is busy */
1111         case CAM_UA_ABORT:      /* Unable to abort CCB request */
1112                 return (EBUSY);
1113         default:
1114                 return (ENXIO);
1115         }
1116 }
1117
1118 static size_t
1119 targccblen(xpt_opcode func_code)
1120 {
1121         int len;
1122
1123         /* Codes we expect to see as a target */
1124         switch (func_code) {
1125         case XPT_CONT_TARGET_IO:
1126         case XPT_SCSI_IO:
1127                 len = sizeof(struct ccb_scsiio);
1128                 break;
1129         case XPT_ACCEPT_TARGET_IO:
1130                 len = sizeof(struct ccb_accept_tio);
1131                 break;
1132         case XPT_IMMED_NOTIFY:
1133                 len = sizeof(struct ccb_immed_notify);
1134                 break;
1135         case XPT_REL_SIMQ:
1136                 len = sizeof(struct ccb_relsim);
1137                 break;
1138         case XPT_PATH_INQ:
1139                 len = sizeof(struct ccb_pathinq);
1140                 break;
1141         case XPT_DEBUG:
1142                 len = sizeof(struct ccb_debug);
1143                 break;
1144         case XPT_ABORT:
1145                 len = sizeof(struct ccb_abort);
1146                 break;
1147         case XPT_EN_LUN:
1148                 len = sizeof(struct ccb_en_lun);
1149                 break;
1150         default:
1151                 len = sizeof(union ccb);
1152                 break;
1153         }
1154
1155         return (len);
1156 }