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 1.18 2007/11/17 20:28:46 pavalos 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/device.h>
  38 #include <sys/malloc.h>
  39 #include <sys/poll.h>
  40 #include <sys/vnode.h>
  41 #include <sys/devicestat.h>
  42 #include <sys/thread2.h>
  43
  44 #include "../cam.h"
  45 #include "../cam_ccb.h"
  46 #include "../cam_periph.h"
  47 #include "../cam_xpt_periph.h"
  48 #include "scsi_targetio.h"
  49
  50 /* Transaction information attached to each CCB sent by the user */
  51 struct targ_cmd_descr {
  52         struct cam_periph_map_info  mapinfo;
  53         TAILQ_ENTRY(targ_cmd_descr) tqe;
  54         union ccb *user_ccb;
  55         int        priority;
  56         int        func_code;
  57 };
  58
  59 /* Offset into the private CCB area for storing our descriptor */
  60 #define targ_descr      periph_priv.entries[1].ptr
  61
  62 TAILQ_HEAD(descr_queue, targ_cmd_descr);
  63
  64 typedef enum {
  65         TARG_STATE_RESV         = 0x00, /* Invalid state */
  66         TARG_STATE_OPENED       = 0x01, /* Device opened, softc initialized */
  67         TARG_STATE_LUN_ENABLED  = 0x02  /* Device enabled for a path */
  68 } targ_state;
  69
  70 /* Per-instance device software context */
  71 struct targ_softc {
  72         /* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
  73         struct ccb_queue         pending_ccb_queue;
  74
  75         /* Command descriptors awaiting CTIO resources from the XPT */
  76         struct descr_queue       work_queue;
  77
  78         /* Command descriptors that have been aborted back to the user. */
  79         struct descr_queue       abort_queue;
  80
  81         /*
  82          * Queue of CCBs that have been copied out to userland, but our
  83          * userland daemon has not yet seen.
  84          */
  85         struct ccb_queue         user_ccb_queue;
  86
  87         struct cam_periph       *periph;
  88         struct cam_path         *path;
  89         targ_state               state;
  90         struct selinfo           read_select;
  91         struct devstat           device_stats;
  92 };
  93
  94 static d_open_t         targopen;
  95 static d_close_t        targclose;
  96 static d_read_t         targread;
  97 static d_write_t        targwrite;
  98 static d_ioctl_t        targioctl;
  99 static d_poll_t         targpoll;
 100 static d_kqfilter_t     targkqfilter;
 101 static void             targreadfiltdetach(struct knote *kn);
 102 static int              targreadfilt(struct knote *kn, long hint);
 103 static struct filterops targread_filtops =
 104         { 1, NULL, targreadfiltdetach, targreadfilt };
 105
 106 #define TARG_CDEV_MAJOR 65
 107 static struct dev_ops targ_ops = {
 108         { "targ", TARG_CDEV_MAJOR, D_KQFILTER },
 109         .d_open = targopen,
 110         .d_close = targclose,
 111         .d_read = targread,
 112         .d_write = targwrite,
 113         .d_ioctl = targioctl,
 114         .d_poll = targpoll,
 115         .d_kqfilter = targkqfilter
 116 };
 117
 118 static cam_status       targendislun(struct cam_path *path, int enable,
 119                                      int grp6_len, int grp7_len);
 120 static cam_status       targenable(struct targ_softc *softc,
 121                                    struct cam_path *path,
 122                                    int grp6_len, int grp7_len);
 123 static cam_status       targdisable(struct targ_softc *softc);
 124 static periph_ctor_t    targctor;
 125 static periph_dtor_t    targdtor;
 126 static periph_start_t   targstart;
 127 static int              targusermerge(struct targ_softc *softc,
 128                                       struct targ_cmd_descr *descr,
 129                                       union ccb *ccb);
 130 static int              targsendccb(struct targ_softc *softc, union ccb *ccb,
 131                                     struct targ_cmd_descr *descr);
 132 static void             targdone(struct cam_periph *periph,
 133                                  union  ccb *done_ccb);
 134 static int              targreturnccb(struct targ_softc *softc,
 135                                       union  ccb *ccb);
 136 static union ccb *      targgetccb(struct targ_softc *softc, xpt_opcode type,
 137                                    int priority);
 138 static void             targfreeccb(struct targ_softc *softc, union ccb *ccb);
 139 static struct targ_cmd_descr *
 140                         targgetdescr(struct targ_softc *softc);
 141 static periph_init_t    targinit;
 142 static void             targasync(void *callback_arg, u_int32_t code,
 143                                   struct cam_path *path, void *arg);
 144 static void             abort_all_pending(struct targ_softc *softc);
 145 static void             notify_user(struct targ_softc *softc);
 146 static int              targcamstatus(cam_status status);
 147 static size_t           targccblen(xpt_opcode func_code);
 148
 149 static struct periph_driver targdriver =
 150 {
 151         targinit, "targ",
 152         TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
 153 };
 154 PERIPHDRIVER_DECLARE(targ, targdriver);
 155
 156 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
 157
 158 /* Create softc and initialize it. Only one proc can open each targ device. */
 159 static int
 160 targopen(struct dev_open_args *ap)
 161 {
 162         cdev_t dev = ap->a_head.a_dev;
 163         struct targ_softc *softc;
 164
 165         if (dev->si_drv1 != 0) {
 166                 return (EBUSY);
 167         }
 168
 169         /* Mark device busy before any potentially blocking operations */
 170         dev->si_drv1 = (void *)~0;
 171         reference_dev(dev);             /* save ref for later destroy_dev() */
 172
 173         /* Create the targ device, allocate its softc, initialize it */
 174         make_dev(&targ_ops, minor(dev), UID_ROOT, GID_WHEEL, 0600,
 175                          "targ%d", lminor(dev));
 176         MALLOC(softc, struct targ_softc *, sizeof(*softc), M_TARG,
 177                M_INTWAIT | M_ZERO);
 178         dev->si_drv1 = softc;
 179         softc->state = TARG_STATE_OPENED;
 180         softc->periph = NULL;
 181         softc->path = NULL;
 182
 183         TAILQ_INIT(&softc->pending_ccb_queue);
 184         TAILQ_INIT(&softc->work_queue);
 185         TAILQ_INIT(&softc->abort_queue);
 186         TAILQ_INIT(&softc->user_ccb_queue);
 187
 188         return (0);
 189 }
 190
 191 /* Disable LUN if enabled and teardown softc */
 192 static int
 193 targclose(struct dev_close_args *ap)
 194 {
 195         cdev_t dev = ap->a_head.a_dev;
 196         struct targ_softc     *softc;
 197         int    error;
 198
 199         softc = (struct targ_softc *)dev->si_drv1;
 200         error = targdisable(softc);
 201         if (error == CAM_REQ_CMP) {
 202                 dev->si_drv1 = 0;
 203                 if (softc->periph != NULL) {
 204                         cam_periph_invalidate(softc->periph);
 205                         softc->periph = NULL;
 206                 }
 207                 destroy_dev(dev);       /* eats the open ref */
 208                 FREE(softc, M_TARG);
 209         } else {
 210                 release_dev(dev);
 211         }
 212         return (error);
 213 }
 214
 215 /* Enable/disable LUNs, set debugging level */
 216 static int
 217 targioctl(struct dev_ioctl_args *ap)
 218 {
 219         struct targ_softc *softc;
 220         cam_status         status;
 221
 222         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 223
 224         switch (ap->a_cmd) {
 225         case TARGIOCENABLE:
 226         {
 227                 struct ioc_enable_lun   *new_lun;
 228                 struct cam_path         *path;
 229
 230                 new_lun = (struct ioc_enable_lun *)ap->a_data;
 231                 status = xpt_create_path(&path, /*periph*/NULL,
 232                                          new_lun->path_id,
 233                                          new_lun->target_id,
 234                                          new_lun->lun_id);
 235                 if (status != CAM_REQ_CMP) {
 236                         kprintf("Couldn't create path, status %#x\n", status);
 237                         break;
 238                 }
 239                 status = targenable(softc, path, new_lun->grp6_len,
 240                                     new_lun->grp7_len);
 241                 xpt_free_path(path);
 242                 break;
 243         }
 244         case TARGIOCDISABLE:
 245                 status = targdisable(softc);
 246                 break;
 247         case TARGIOCDEBUG:
 248         {
 249 #ifdef  CAMDEBUG
 250                 struct ccb_debug cdbg;
 251
 252                 bzero(&cdbg, sizeof cdbg);
 253                 if (*((int *)ap->a_data) != 0)
 254                         cdbg.flags = CAM_DEBUG_PERIPH;
 255                 else
 256                         cdbg.flags = CAM_DEBUG_NONE;
 257                 xpt_setup_ccb(&cdbg.ccb_h, softc->path, /*priority*/0);
 258                 cdbg.ccb_h.func_code = XPT_DEBUG;
 259                 cdbg.ccb_h.cbfcnp = targdone;
 260
 261                 /* If no periph available, disallow debugging changes */
 262                 if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 263                         status = CAM_DEV_NOT_THERE;
 264                         break;
 265                 }
 266                 xpt_action((union ccb *)&cdbg);
 267                 status = cdbg.ccb_h.status & CAM_STATUS_MASK;
 268 #else
 269                 status = CAM_FUNC_NOTAVAIL;
 270 #endif
 271                 break;
 272         }
 273         default:
 274                 status = CAM_PROVIDE_FAIL;
 275                 break;
 276         }
 277
 278         return (targcamstatus(status));
 279 }
 280
 281 /* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
 282 static int
 283 targpoll(struct dev_poll_args *ap)
 284 {
 285         struct targ_softc *softc;
 286         int     revents;
 287
 288         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 289
 290         /* Poll for write() is always ok. */
 291         revents = ap->a_events & (POLLOUT | POLLWRNORM);
 292         if ((ap->a_events & (POLLIN | POLLRDNORM)) != 0) {
 293                 crit_enter();
 294                 /* Poll for read() depends on user and abort queues. */
 295                 if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
 296                     !TAILQ_EMPTY(&softc->abort_queue)) {
 297                         revents |= ap->a_events & (POLLIN | POLLRDNORM);
 298                 }
 299                 /* Only sleep if the user didn't poll for write. */
 300                 if (revents == 0)
 301                         selrecord(curthread, &softc->read_select);
 302                 crit_exit();
 303         }
 304         ap->a_events = revents;
 305         return (0);
 306 }
 307
 308 static int
 309 targkqfilter(struct dev_kqfilter_args *ap)
 310 {
 311         struct  knote *kn = ap->a_kn;
 312         struct  targ_softc *softc;
 313
 314         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 315         kn->kn_hook = (caddr_t)softc;
 316         kn->kn_fop = &targread_filtops;
 317         crit_enter();
 318         SLIST_INSERT_HEAD(&softc->read_select.si_note, kn, kn_selnext);
 319         crit_exit();
 320         return (0);
 321 }
 322
 323 static void
 324 targreadfiltdetach(struct knote *kn)
 325 {
 326         struct  targ_softc *softc;
 327
 328         softc = (struct targ_softc *)kn->kn_hook;
 329         crit_enter();
 330         SLIST_REMOVE(&softc->read_select.si_note, kn, knote, kn_selnext);
 331         crit_exit();
 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;
 340
 341         softc = (struct targ_softc *)kn->kn_hook;
 342         crit_enter();
 343         retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
 344                  !TAILQ_EMPTY(&softc->abort_queue);
 345         crit_exit();
 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                 kprintf("%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                 kprintf("pathinq failed, status %#x\n", status);
 392                 goto enable_fail;
 393         }
 394         if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
 395                 kprintf("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                         kprintf("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                 kprintf("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                 kprintf("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
 449         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
 450                 return (CAM_REQ_CMP);
 451
 452         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
 453
 454         /* Abort any ccbs pending on the controller */
 455         crit_enter();
 456         abort_all_pending(softc);
 457         crit_exit();
 458
 459         /* Disable this lun */
 460         status = targendislun(softc->path, /*enable*/0,
 461                               /*grp6_len*/0, /*grp7_len*/0);
 462         if (status == CAM_REQ_CMP)
 463                 softc->state &= ~TARG_STATE_LUN_ENABLED;
 464         else
 465                 kprintf("Disable lun failed, status %#x\n", status);
 466
 467         return (status);
 468 }
 469
 470 /* Initialize a periph (called from cam_periph_alloc) */
 471 static cam_status
 472 targctor(struct cam_periph *periph, void *arg)
 473 {
 474         struct targ_softc *softc;
 475
 476         /* Store pointer to softc for periph-driven routines */
 477         softc = (struct targ_softc *)arg;
 478         periph->softc = softc;
 479         softc->periph = periph;
 480         softc->path = periph->path;
 481         return (CAM_REQ_CMP);
 482 }
 483
 484 static void
 485 targdtor(struct cam_periph *periph)
 486 {
 487         struct targ_softc     *softc;
 488         struct ccb_hdr        *ccb_h;
 489         struct targ_cmd_descr *descr;
 490
 491         softc = (struct targ_softc *)periph->softc;
 492
 493         /*
 494          * targdisable() aborts CCBs back to the user and leaves them
 495          * on user_ccb_queue and abort_queue in case the user is still
 496          * interested in them.  We free them now.
 497          */
 498         while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
 499                 TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
 500                 targfreeccb(softc, (union ccb *)ccb_h);
 501         }
 502         while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
 503                 TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
 504                 FREE(descr, M_TARG);
 505         }
 506
 507         softc->periph = NULL;
 508         softc->path = NULL;
 509         periph->softc = NULL;
 510 }
 511
 512 /* Receive CCBs from user mode proc and send them to the HBA */
 513 static int
 514 targwrite(struct dev_write_args *ap)
 515 {
 516         struct uio *uio = ap->a_uio;
 517         union ccb *user_ccb;
 518         struct targ_softc *softc;
 519         struct targ_cmd_descr *descr;
 520         int write_len, error;
 521         int func_code, priority;
 522
 523         softc = (struct targ_softc *)ap->a_head.a_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
 530                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 531                 if (error != 0) {
 532                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 533                                   ("write - uiomove failed (%d)\n", error));
 534                         break;
 535                 }
 536                 priority = fuword(&user_ccb->ccb_h.pinfo.priority);
 537                 if (priority == -1) {
 538                         error = EINVAL;
 539                         break;
 540                 }
 541                 func_code = fuword(&user_ccb->ccb_h.func_code);
 542                 switch (func_code) {
 543                 case XPT_ACCEPT_TARGET_IO:
 544                 case XPT_IMMED_NOTIFY:
 545                         ccb = targgetccb(softc, func_code, priority);
 546                         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 547                         descr->user_ccb = user_ccb;
 548                         descr->func_code = func_code;
 549                         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 550                                   ("Sent ATIO/INOT (%p)\n", user_ccb));
 551                         xpt_action(ccb);
 552                         crit_enter();
 553                         TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
 554                                           &ccb->ccb_h,
 555                                           periph_links.tqe);
 556                         crit_exit();
 557                         break;
 558                 default:
 559                         if ((func_code & XPT_FC_QUEUED) != 0) {
 560                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 561                                           ("Sending queued ccb %#x (%p)\n",
 562                                           func_code, user_ccb));
 563                                 descr = targgetdescr(softc);
 564                                 descr->user_ccb = user_ccb;
 565                                 descr->priority = priority;
 566                                 descr->func_code = func_code;
 567                                 crit_enter();
 568                                 TAILQ_INSERT_TAIL(&softc->work_queue,
 569                                                   descr, tqe);
 570                                 crit_exit();
 571                                 xpt_schedule(softc->periph, priority);
 572                         } else {
 573                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 574                                           ("Sending inline ccb %#x (%p)\n",
 575                                           func_code, user_ccb));
 576                                 ccb = targgetccb(softc, func_code, priority);
 577                                 descr = (struct targ_cmd_descr *)
 578                                          ccb->ccb_h.targ_descr;
 579                                 descr->user_ccb = user_ccb;
 580                                 descr->priority = priority;
 581                                 descr->func_code = func_code;
 582                                 if (targusermerge(softc, descr, ccb) != EFAULT)
 583                                         targsendccb(softc, ccb, descr);
 584                                 targreturnccb(softc, ccb);
 585                         }
 586                         break;
 587                 }
 588                 write_len += sizeof(user_ccb);
 589         }
 590
 591         /*
 592          * If we've successfully taken in some amount of
 593          * data, return success for that data first.  If
 594          * an error is persistent, it will be reported
 595          * on the next write.
 596          */
 597         if (error != 0 && write_len == 0)
 598                 return (error);
 599         if (write_len == 0 && uio->uio_resid != 0)
 600                 return (ENOSPC);
 601         return (0);
 602 }
 603
 604 /* Process requests (descrs) via the periph-supplied CCBs */
 605 static void
 606 targstart(struct cam_periph *periph, union ccb *start_ccb)
 607 {
 608         struct targ_softc *softc;
 609         struct targ_cmd_descr *descr, *next_descr;
 610         int error;
 611
 612         softc = (struct targ_softc *)periph->softc;
 613         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
 614
 615         crit_enter();
 616         descr = TAILQ_FIRST(&softc->work_queue);
 617         if (descr == NULL) {
 618                 crit_exit();
 619                 xpt_release_ccb(start_ccb);
 620         } else {
 621                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
 622                 next_descr = TAILQ_FIRST(&softc->work_queue);
 623                 crit_exit();
 624
 625                 /* Initiate a transaction using the descr and supplied CCB */
 626                 error = targusermerge(softc, descr, start_ccb);
 627                 if (error == 0)
 628                         error = targsendccb(softc, start_ccb, descr);
 629                 if (error != 0) {
 630                         xpt_print_path(periph->path);
 631                         kprintf("targsendccb failed, err %d\n", error);
 632                         xpt_release_ccb(start_ccb);
 633                         suword(&descr->user_ccb->ccb_h.status,
 634                                CAM_REQ_CMP_ERR);
 635                         crit_enter();
 636                         TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
 637                         crit_exit();
 638                         notify_user(softc);
 639                 }
 640
 641                 /* If we have more work to do, stay scheduled */
 642                 if (next_descr != NULL)
 643                         xpt_schedule(periph, next_descr->priority);
 644         }
 645 }
 646
 647 static int
 648 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
 649               union ccb *ccb)
 650 {
 651         struct ccb_hdr *u_ccbh, *k_ccbh;
 652         size_t ccb_len;
 653         int error;
 654
 655         u_ccbh = &descr->user_ccb->ccb_h;
 656         k_ccbh = &ccb->ccb_h;
 657
 658         /*
 659          * There are some fields in the CCB header that need to be
 660          * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
 661          */
 662         xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
 663         k_ccbh->retry_count = fuword(&u_ccbh->retry_count);
 664         k_ccbh->func_code = descr->func_code;
 665         k_ccbh->flags = fuword(&u_ccbh->flags);
 666         k_ccbh->timeout = fuword(&u_ccbh->timeout);
 667         ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
 668         error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
 669         if (error != 0) {
 670                 k_ccbh->status = CAM_REQ_CMP_ERR;
 671                 return (error);
 672         }
 673
 674         /* Translate usermode abort_ccb pointer to its kernel counterpart */
 675         if (k_ccbh->func_code == XPT_ABORT) {
 676                 struct ccb_abort *cab;
 677                 struct ccb_hdr *ccb_h;
 678
 679                 cab = (struct ccb_abort *)ccb;
 680                 crit_enter();
 681                 TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
 682                     periph_links.tqe) {
 683                         struct targ_cmd_descr *ab_descr;
 684
 685                         ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 686                         if (ab_descr->user_ccb == cab->abort_ccb) {
 687                                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 688                                           ("Changing abort for %p to %p\n",
 689                                           cab->abort_ccb, ccb_h));
 690                                 cab->abort_ccb = (union ccb *)ccb_h;
 691                                 break;
 692                         }
 693                 }
 694                 crit_exit();
 695                 /* CCB not found, set appropriate status */
 696                 if (ccb_h == NULL) {
 697                         k_ccbh->status = CAM_PATH_INVALID;
 698                         error = ESRCH;
 699                 }
 700         }
 701
 702         return (error);
 703 }
 704
 705 /* Build and send a kernel CCB formed from descr->user_ccb */
 706 static int
 707 targsendccb(struct targ_softc *softc, union ccb *ccb,
 708             struct targ_cmd_descr *descr)
 709 {
 710         struct cam_periph_map_info *mapinfo;
 711         struct ccb_hdr *ccb_h;
 712         int error;
 713
 714         ccb_h = &ccb->ccb_h;
 715         mapinfo = &descr->mapinfo;
 716         mapinfo->num_bufs_used = 0;
 717
 718         /*
 719          * There's no way for the user to have a completion
 720          * function, so we put our own completion function in here.
 721          * We also stash in a reference to our descriptor so targreturnccb()
 722          * can find our mapping info.
 723          */
 724         ccb_h->cbfcnp = targdone;
 725         ccb_h->targ_descr = descr;
 726
 727         /*
 728          * We only attempt to map the user memory into kernel space
 729          * if they haven't passed in a physical memory pointer,
 730          * and if there is actually an I/O operation to perform.
 731          * Right now cam_periph_mapmem() only supports SCSI and device
 732          * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
 733          * there's actually data to map.  cam_periph_mapmem() will do the
 734          * right thing, even if there isn't data to map, but since CCBs
 735          * without data are a reasonably common occurance (e.g. test unit
 736          * ready), it will save a few cycles if we check for it here.
 737          */
 738         if (((ccb_h->flags & CAM_DATA_PHYS) == 0)
 739          && (((ccb_h->func_code == XPT_CONT_TARGET_IO)
 740             && ((ccb_h->flags & CAM_DIR_MASK) != CAM_DIR_NONE))
 741           || (ccb_h->func_code == XPT_DEV_MATCH))) {
 742
 743                 error = cam_periph_mapmem(ccb, mapinfo);
 744
 745                 /*
 746                  * cam_periph_mapmem returned an error, we can't continue.
 747                  * Return the error to the user.
 748                  */
 749                 if (error) {
 750                         ccb_h->status = CAM_REQ_CMP_ERR;
 751                         mapinfo->num_bufs_used = 0;
 752                         return (error);
 753                 }
 754         }
 755
 756         /*
 757          * Once queued on the pending CCB list, this CCB will be protected
 758          * by our error recovery handler.
 759          */
 760         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
 761         if (XPT_FC_IS_QUEUED(ccb)) {
 762                 crit_enter();
 763                 TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
 764                                   periph_links.tqe);
 765                 crit_exit();
 766         }
 767         xpt_action(ccb);
 768
 769         return (0);
 770 }
 771
 772 /* Completion routine for CCBs (called in a critical section) */
 773 static void
 774 targdone(struct cam_periph *periph, union ccb *done_ccb)
 775 {
 776         struct targ_softc *softc;
 777         cam_status status;
 778
 779         CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
 780         softc = (struct targ_softc *)periph->softc;
 781         TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
 782                      periph_links.tqe);
 783         status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
 784
 785         /* If we're no longer enabled, throw away CCB */
 786         if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
 787                 targfreeccb(softc, done_ccb);
 788                 return;
 789         }
 790         /* abort_all_pending() waits for pending queue to be empty */
 791         if (TAILQ_EMPTY(&softc->pending_ccb_queue))
 792                 wakeup(&softc->pending_ccb_queue);
 793
 794         switch (done_ccb->ccb_h.func_code) {
 795         /* All FC_*_QUEUED CCBs go back to userland */
 796         case XPT_IMMED_NOTIFY:
 797         case XPT_ACCEPT_TARGET_IO:
 798         case XPT_CONT_TARGET_IO:
 799                 TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
 800                                   periph_links.tqe);
 801                 notify_user(softc);
 802                 break;
 803         default:
 804                 panic("targdone: impossible xpt opcode %#x",
 805                       done_ccb->ccb_h.func_code);
 806                 /* NOTREACHED */
 807         }
 808 }
 809
 810 /* Return CCBs to the user from the user queue and abort queue */
 811 static int
 812 targread(struct dev_read_args *ap)
 813 {
 814         struct uio *uio = ap->a_uio;
 815         struct descr_queue      *abort_queue;
 816         struct targ_cmd_descr   *user_descr;
 817         struct targ_softc       *softc;
 818         struct ccb_queue  *user_queue;
 819         struct ccb_hdr    *ccb_h;
 820         union  ccb        *user_ccb;
 821         int                read_len, error;
 822
 823         error = 0;
 824         read_len = 0;
 825         softc = (struct targ_softc *)ap->a_head.a_dev->si_drv1;
 826         user_queue = &softc->user_ccb_queue;
 827         abort_queue = &softc->abort_queue;
 828         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
 829
 830         /* If no data is available, wait or return immediately */
 831         crit_enter();
 832         ccb_h = TAILQ_FIRST(user_queue);
 833         user_descr = TAILQ_FIRST(abort_queue);
 834         while (ccb_h == NULL && user_descr == NULL) {
 835                 if ((ap->a_ioflag & IO_NDELAY) == 0) {
 836                         error = tsleep(user_queue, PCATCH, "targrd", 0);
 837                         ccb_h = TAILQ_FIRST(user_queue);
 838                         user_descr = TAILQ_FIRST(abort_queue);
 839                         if (error != 0) {
 840                                 if (error == ERESTART) {
 841                                         continue;
 842                                 } else {
 843                                         crit_exit();
 844                                         goto read_fail;
 845                                 }
 846                         }
 847                 } else {
 848                         crit_exit();
 849                         return (EAGAIN);
 850                 }
 851         }
 852
 853         /* Data is available so fill the user's buffer */
 854         while (ccb_h != NULL) {
 855                 struct targ_cmd_descr *descr;
 856
 857                 if (uio->uio_resid < sizeof(user_ccb))
 858                         break;
 859                 TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
 860                 crit_exit();
 861                 descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
 862                 user_ccb = descr->user_ccb;
 863                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 864                           ("targread ccb %p (%p)\n", ccb_h, user_ccb));
 865                 error = targreturnccb(softc, (union ccb *)ccb_h);
 866                 if (error != 0)
 867                         goto read_fail;
 868                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 869                 if (error != 0)
 870                         goto read_fail;
 871                 read_len += sizeof(user_ccb);
 872
 873                 crit_enter();
 874                 ccb_h = TAILQ_FIRST(user_queue);
 875         }
 876
 877         /* Flush out any aborted descriptors */
 878         while (user_descr != NULL) {
 879                 if (uio->uio_resid < sizeof(user_ccb))
 880                         break;
 881                 TAILQ_REMOVE(abort_queue, user_descr, tqe);
 882                 crit_exit();
 883                 user_ccb = user_descr->user_ccb;
 884                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
 885                           ("targread aborted descr %p (%p)\n",
 886                           user_descr, user_ccb));
 887                 suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
 888                 error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
 889                 if (error != 0)
 890                         goto read_fail;
 891                 read_len += sizeof(user_ccb);
 892
 893                 crit_enter();
 894                 user_descr = TAILQ_FIRST(abort_queue);
 895         }
 896         crit_exit();
 897
 898         /*
 899          * If we've successfully read some amount of data, don't report an
 900          * error.  If the error is persistent, it will be reported on the
 901          * next read().
 902          */
 903         if (read_len == 0 && uio->uio_resid != 0)
 904                 error = ENOSPC;
 905
 906 read_fail:
 907         return (error);
 908 }
 909
 910 /* Copy completed ccb back to the user */
 911 static int
 912 targreturnccb(struct targ_softc *softc, union ccb *ccb)
 913 {
 914         struct targ_cmd_descr *descr;
 915         struct ccb_hdr *u_ccbh;
 916         size_t ccb_len;
 917         int error;
 918
 919         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
 920         descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
 921         u_ccbh = &descr->user_ccb->ccb_h;
 922
 923         /* Copy out the central portion of the ccb_hdr */
 924         copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
 925                 offsetof(struct ccb_hdr, periph_priv) -
 926                 offsetof(struct ccb_hdr, retry_count));
 927
 928         /* Copy out the rest of the ccb (after the ccb_hdr) */
 929         ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
 930         if (descr->mapinfo.num_bufs_used != 0)
 931                 cam_periph_unmapmem(ccb, &descr->mapinfo);
 932         error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
 933         if (error != 0) {
 934                 xpt_print_path(softc->path);
 935                 kprintf("targreturnccb - CCB copyout failed (%d)\n",
 936                        error);
 937         }
 938         /* Free CCB or send back to devq. */
 939         targfreeccb(softc, ccb);
 940
 941         return (error);
 942 }
 943
 944 static union ccb *
 945 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
 946 {
 947         union ccb *ccb;
 948         int ccb_len;
 949
 950         ccb_len = targccblen(type);
 951         MALLOC(ccb, union ccb *, ccb_len, M_TARG, M_INTWAIT);
 952         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
 953
 954         xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
 955         ccb->ccb_h.func_code = type;
 956         ccb->ccb_h.cbfcnp = targdone;
 957         ccb->ccb_h.targ_descr = targgetdescr(softc);
 958         return (ccb);
 959 }
 960
 961 static void
 962 targfreeccb(struct targ_softc *softc, union ccb *ccb)
 963 {
 964         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
 965                         ccb->ccb_h.targ_descr));
 966         FREE(ccb->ccb_h.targ_descr, M_TARG);
 967
 968         switch (ccb->ccb_h.func_code) {
 969         case XPT_ACCEPT_TARGET_IO:
 970         case XPT_IMMED_NOTIFY:
 971                 CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
 972                 FREE(ccb, M_TARG);
 973                 break;
 974         default:
 975                 /* Send back CCB if we got it from the periph */
 976                 if (XPT_FC_IS_QUEUED(ccb)) {
 977                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
 978                                         ("returning queued ccb %p\n", ccb));
 979                         xpt_release_ccb(ccb);
 980                 } else {
 981                         CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
 982                                         ("freeing ccb %p\n", ccb));
 983                         FREE(ccb, M_TARG);
 984                 }
 985                 break;
 986         }
 987 }
 988
 989 static struct targ_cmd_descr *
 990 targgetdescr(struct targ_softc *softc)
 991 {
 992         struct targ_cmd_descr *descr;
 993
 994         MALLOC(descr, struct targ_cmd_descr *, sizeof(*descr),
 995                 M_TARG, M_INTWAIT);
 996         descr->mapinfo.num_bufs_used = 0;
 997         return (descr);
 998 }
 999
1000 static void
1001 targinit(void)
1002 {
1003         dev_ops_add(&targ_ops, 0, 0);
1004 }
1005
1006 static void
1007 targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
1008 {
1009         /* All events are handled in usermode by INOTs */
1010         panic("targasync() called, should be an INOT instead");
1011 }
1012
1013 /* Cancel all pending requests and CCBs awaiting work. */
1014 static void
1015 abort_all_pending(struct targ_softc *softc)
1016 {
1017         struct targ_cmd_descr   *descr;
1018         struct ccb_abort         cab;
1019         struct ccb_hdr          *ccb_h;
1020
1021         CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1022
1023         /* First abort the descriptors awaiting resources */
1024         while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1025                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1026                           ("Aborting descr from workq %p\n", descr));
1027                 TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1028                 TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1029         }
1030
1031         /*
1032          * Then abort all pending CCBs.
1033          * targdone() will return the aborted CCB via user_ccb_queue
1034          */
1035         xpt_setup_ccb(&cab.ccb_h, softc->path, /*priority*/0);
1036         cab.ccb_h.func_code = XPT_ABORT;
1037         cab.ccb_h.status = CAM_REQ_CMP_ERR;
1038         TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1039                 CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1040                           ("Aborting pending CCB %p\n", ccb_h));
1041                 cab.abort_ccb = (union ccb *)ccb_h;
1042                 xpt_action((union ccb *)&cab);
1043                 if (cab.ccb_h.status != CAM_REQ_CMP) {
1044                         xpt_print_path(cab.ccb_h.path);
1045                         kprintf("Unable to abort CCB, status %#x\n",
1046                                cab.ccb_h.status);
1047                 }
1048         }
1049
1050         /* If we aborted at least one pending CCB ok, wait for it. */
1051         if (cab.ccb_h.status == CAM_REQ_CMP) {
1052                 tsleep(&softc->pending_ccb_queue, PCATCH, "tgabrt", 0);
1053         }
1054
1055         /* If we aborted anything from the work queue, wakeup user. */
1056         if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1057          || !TAILQ_EMPTY(&softc->abort_queue))
1058                 notify_user(softc);
1059 }
1060
1061 /* Notify the user that data is ready */
1062 static void
1063 notify_user(struct targ_softc *softc)
1064 {
1065         /*
1066          * Notify users sleeping via poll(), kqueue(), and
1067          * blocking read().
1068          */
1069         selwakeup(&softc->read_select);
1070         KNOTE(&softc->read_select.si_note, 0);
1071         wakeup(&softc->user_ccb_queue);
1072 }
1073
1074 /* Convert CAM status to errno values */
1075 static int
1076 targcamstatus(cam_status status)
1077 {
1078         switch (status & CAM_STATUS_MASK) {
1079         case CAM_REQ_CMP:       /* CCB request completed without error */
1080                 return (0);
1081         case CAM_REQ_INPROG:    /* CCB request is in progress */
1082                 return (EINPROGRESS);
1083         case CAM_REQ_CMP_ERR:   /* CCB request completed with an error */
1084                 return (EIO);
1085         case CAM_PROVIDE_FAIL:  /* Unable to provide requested capability */
1086                 return (ENOTTY);
1087         case CAM_FUNC_NOTAVAIL: /* The requested function is not available */
1088                 return (ENOTSUP);
1089         case CAM_LUN_ALRDY_ENA: /* LUN is already enabled for target mode */
1090                 return (EADDRINUSE);
1091         case CAM_PATH_INVALID:  /* Supplied Path ID is invalid */
1092         case CAM_DEV_NOT_THERE: /* SCSI Device Not Installed/there */
1093                 return (ENOENT);
1094         case CAM_REQ_ABORTED:   /* CCB request aborted by the host */
1095                 return (ECANCELED);
1096         case CAM_CMD_TIMEOUT:   /* Command timeout */
1097                 return (ETIMEDOUT);
1098         case CAM_REQUEUE_REQ:   /* Requeue to preserve transaction ordering */
1099                 return (EAGAIN);
1100         case CAM_REQ_INVALID:   /* CCB request was invalid */
1101                 return (EINVAL);
1102         case CAM_RESRC_UNAVAIL: /* Resource Unavailable */
1103                 return (ENOMEM);
1104         case CAM_BUSY:          /* CAM subsytem is busy */
1105         case CAM_UA_ABORT:      /* Unable to abort CCB request */
1106                 return (EBUSY);
1107         default:
1108                 return (ENXIO);
1109         }
1110 }
1111
1112 static size_t
1113 targccblen(xpt_opcode func_code)
1114 {
1115         int len;
1116
1117         /* Codes we expect to see as a target */
1118         switch (func_code) {
1119         case XPT_CONT_TARGET_IO:
1120         case XPT_SCSI_IO:
1121                 len = sizeof(struct ccb_scsiio);
1122                 break;
1123         case XPT_ACCEPT_TARGET_IO:
1124                 len = sizeof(struct ccb_accept_tio);
1125                 break;
1126         case XPT_IMMED_NOTIFY:
1127                 len = sizeof(struct ccb_immed_notify);
1128                 break;
1129         case XPT_REL_SIMQ:
1130                 len = sizeof(struct ccb_relsim);
1131                 break;
1132         case XPT_PATH_INQ:
1133                 len = sizeof(struct ccb_pathinq);
1134                 break;
1135         case XPT_DEBUG:
1136                 len = sizeof(struct ccb_debug);
1137                 break;
1138         case XPT_ABORT:
1139                 len = sizeof(struct ccb_abort);
1140                 break;
1141         case XPT_EN_LUN:
1142                 len = sizeof(struct ccb_en_lun);
1143                 break;
1144         default:
1145                 len = sizeof(union ccb);
1146                 break;
1147         }
1148
1149         return (len);
1150 }