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1 /*-
2  * Implementation of the Target Mode 'Black Hole device' for CAM.
3  *
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 1999 Justin T. Gibbs.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification, immediately at the beginning of the file.
15  * 2. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30
31 #include <sys/cdefs.h>
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/types.h>
37 #include <sys/bio.h>
38 #include <sys/conf.h>
39 #include <sys/devicestat.h>
40 #include <sys/malloc.h>
41 #include <sys/uio.h>
42
43 #include <cam/cam.h>
44 #include <cam/cam_ccb.h>
45 #include <cam/cam_periph.h>
46 #include <cam/cam_queue.h>
47 #include <cam/cam_xpt_periph.h>
48 #include <cam/cam_debug.h>
49 #include <cam/cam_sim.h>
50
51 #include <cam/scsi/scsi_all.h>
52 #include <cam/scsi/scsi_message.h>
53
54 static MALLOC_DEFINE(M_SCSIBH, "SCSI bh", "SCSI blackhole buffers");
55
56 typedef enum {
57         TARGBH_STATE_NORMAL,
58         TARGBH_STATE_EXCEPTION,
59         TARGBH_STATE_TEARDOWN
60 } targbh_state;
61
62 typedef enum {
63         TARGBH_FLAG_NONE         = 0x00,
64         TARGBH_FLAG_LUN_ENABLED  = 0x01
65 } targbh_flags;
66
67 typedef enum {
68         TARGBH_CCB_WORKQ
69 } targbh_ccb_types;
70
71 #define MAX_ACCEPT      8
72 #define MAX_IMMEDIATE   16
73 #define MAX_BUF_SIZE    256     /* Max inquiry/sense/mode page transfer */
74
75 /* Offsets into our private CCB area for storing accept information */
76 #define ccb_type        ppriv_field0
77 #define ccb_descr       ppriv_ptr1
78
79 /* We stick a pointer to the originating accept TIO in each continue I/O CCB */
80 #define ccb_atio        ppriv_ptr1
81
82 TAILQ_HEAD(ccb_queue, ccb_hdr);
83
84 struct targbh_softc {
85         struct          ccb_queue pending_queue;
86         struct          ccb_queue work_queue;
87         struct          ccb_queue unknown_atio_queue;
88         struct          devstat device_stats;
89         targbh_state    state;
90         targbh_flags    flags;  
91         u_int           init_level;
92         u_int           inq_data_len;
93         struct          ccb_accept_tio *accept_tio_list;
94         struct          ccb_hdr_slist immed_notify_slist;
95 };
96
97 struct targbh_cmd_desc {
98         struct    ccb_accept_tio* atio_link;
99         u_int     data_resid;   /* How much left to transfer */
100         u_int     data_increment;/* Amount to send before next disconnect */
101         void*     data;         /* The data. Can be from backing_store or not */
102         void*     backing_store;/* Backing store allocated for this descriptor*/
103         u_int     max_size;     /* Size of backing_store */
104         uint32_t timeout;       
105         uint8_t  status;        /* Status to return to initiator */
106 };
107
108 static struct scsi_inquiry_data no_lun_inq_data =
109 {
110         T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
111         /* version */2, /* format version */2
112 };
113
114 static struct scsi_sense_data_fixed no_lun_sense_data =
115 {
116         SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
117         0,
118         SSD_KEY_NOT_READY, 
119         { 0, 0, 0, 0 },
120         /*extra_len*/offsetof(struct scsi_sense_data_fixed, fru)
121                    - offsetof(struct scsi_sense_data_fixed, extra_len),
122         { 0, 0, 0, 0 },
123         /* Logical Unit Not Supported */
124         /*ASC*/0x25, /*ASCQ*/0
125 };
126
127 static const int request_sense_size = offsetof(struct scsi_sense_data_fixed, fru);
128
129 static periph_init_t    targbhinit;
130 static void             targbhasync(void *callback_arg, uint32_t code,
131                                     struct cam_path *path, void *arg);
132 static cam_status       targbhenlun(struct cam_periph *periph);
133 static cam_status       targbhdislun(struct cam_periph *periph);
134 static periph_ctor_t    targbhctor;
135 static periph_dtor_t    targbhdtor;
136 static periph_start_t   targbhstart;
137 static void             targbhdone(struct cam_periph *periph,
138                                    union ccb *done_ccb);
139 #ifdef NOTYET
140 static  int             targbherror(union ccb *ccb, uint32_t cam_flags,
141                                     uint32_t sense_flags);
142 #endif
143 static struct targbh_cmd_desc*  targbhallocdescr(void);
144 static void             targbhfreedescr(struct targbh_cmd_desc *buf);
145                                         
146 static struct periph_driver targbhdriver =
147 {
148         targbhinit, "targbh",
149         TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
150 };
151
152 PERIPHDRIVER_DECLARE(targbh, targbhdriver);
153
154 static void
155 targbhinit(void)
156 {
157         cam_status status;
158
159         /*
160          * Install a global async callback.  This callback will
161          * receive async callbacks like "new path registered".
162          */
163         status = xpt_register_async(AC_PATH_REGISTERED | AC_PATH_DEREGISTERED,
164                                     targbhasync, NULL, NULL);
165
166         if (status != CAM_REQ_CMP) {
167                 printf("targbh: Failed to attach master async callback "
168                        "due to status 0x%x!\n", status);
169         }
170 }
171
172 static void
173 targbhasync(void *callback_arg, uint32_t code,
174             struct cam_path *path, void *arg)
175 {
176         struct cam_path *new_path;
177         struct ccb_pathinq *cpi;
178         path_id_t bus_path_id;
179         cam_status status;
180
181         cpi = (struct ccb_pathinq *)arg;
182         if (code == AC_PATH_REGISTERED)
183                 bus_path_id = cpi->ccb_h.path_id;
184         else
185                 bus_path_id = xpt_path_path_id(path);
186         /*
187          * Allocate a peripheral instance for
188          * this target instance.
189          */
190         status = xpt_create_path(&new_path, NULL,
191                                  bus_path_id,
192                                  CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
193         if (status != CAM_REQ_CMP) {
194                 printf("targbhasync: Unable to create path "
195                         "due to status 0x%x\n", status);
196                 return;
197         }
198
199         switch (code) {
200         case AC_PATH_REGISTERED:
201         {
202                 /* Only attach to controllers that support target mode */
203                 if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
204                         break;
205
206                 status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
207                                           targbhstart,
208                                           "targbh", CAM_PERIPH_BIO,
209                                           new_path, targbhasync,
210                                           AC_PATH_REGISTERED,
211                                           cpi);
212                 break;
213         }
214         case AC_PATH_DEREGISTERED:
215         {
216                 struct cam_periph *periph;
217
218                 if ((periph = cam_periph_find(new_path, "targbh")) != NULL)
219                         cam_periph_invalidate(periph);
220                 break;
221         }
222         default:
223                 break;
224         }
225         xpt_free_path(new_path);
226 }
227
228 /* Attempt to enable our lun */
229 static cam_status
230 targbhenlun(struct cam_periph *periph)
231 {
232         union ccb immed_ccb;
233         struct targbh_softc *softc;
234         cam_status status;
235         int i;
236
237         softc = (struct targbh_softc *)periph->softc;
238
239         if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
240                 return (CAM_REQ_CMP);
241
242         memset(&immed_ccb, 0, sizeof(immed_ccb));
243         xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
244         immed_ccb.ccb_h.func_code = XPT_EN_LUN;
245
246         /* Don't need support for any vendor specific commands */
247         immed_ccb.cel.grp6_len = 0;
248         immed_ccb.cel.grp7_len = 0;
249         immed_ccb.cel.enable = 1;
250         xpt_action(&immed_ccb);
251         status = immed_ccb.ccb_h.status;
252         if (status != CAM_REQ_CMP) {
253                 xpt_print(periph->path,
254                     "targbhenlun - Enable Lun Rejected with status 0x%x\n",
255                     status);
256                 return (status);
257         }
258
259         softc->flags |= TARGBH_FLAG_LUN_ENABLED;
260
261         /*
262          * Build up a buffer of accept target I/O
263          * operations for incoming selections.
264          */
265         for (i = 0; i < MAX_ACCEPT; i++) {
266                 struct ccb_accept_tio *atio;
267
268                 atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_SCSIBH,
269                                                       M_ZERO | M_NOWAIT);
270                 if (atio == NULL) {
271                         status = CAM_RESRC_UNAVAIL;
272                         break;
273                 }
274
275                 atio->ccb_h.ccb_descr = targbhallocdescr();
276
277                 if (atio->ccb_h.ccb_descr == NULL) {
278                         free(atio, M_SCSIBH);
279                         status = CAM_RESRC_UNAVAIL;
280                         break;
281                 }
282
283                 xpt_setup_ccb(&atio->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
284                 atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
285                 atio->ccb_h.cbfcnp = targbhdone;
286                 ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
287                     softc->accept_tio_list;
288                 softc->accept_tio_list = atio;
289                 xpt_action((union ccb *)atio);
290                 status = atio->ccb_h.status;
291                 if (status != CAM_REQ_INPROG)
292                         break;
293         }
294
295         if (i == 0) {
296                 xpt_print(periph->path,
297                     "targbhenlun - Could not allocate accept tio CCBs: status "
298                     "= 0x%x\n", status);
299                 targbhdislun(periph);
300                 return (CAM_REQ_CMP_ERR);
301         }
302
303         /*
304          * Build up a buffer of immediate notify CCBs
305          * so the SIM can tell us of asynchronous target mode events.
306          */
307         for (i = 0; i < MAX_ACCEPT; i++) {
308                 struct ccb_immediate_notify *inot;
309
310                 inot = (struct ccb_immediate_notify*)malloc(sizeof(*inot),
311                             M_SCSIBH, M_ZERO | M_NOWAIT);
312
313                 if (inot == NULL) {
314                         status = CAM_RESRC_UNAVAIL;
315                         break;
316                 }
317
318                 xpt_setup_ccb(&inot->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
319                 inot->ccb_h.func_code = XPT_IMMEDIATE_NOTIFY;
320                 inot->ccb_h.cbfcnp = targbhdone;
321                 SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
322                                   periph_links.sle);
323                 xpt_action((union ccb *)inot);
324                 status = inot->ccb_h.status;
325                 if (status != CAM_REQ_INPROG)
326                         break;
327         }
328
329         if (i == 0) {
330                 xpt_print(periph->path,
331                     "targbhenlun - Could not allocate immediate notify "
332                     "CCBs: status = 0x%x\n", status);
333                 targbhdislun(periph);
334                 return (CAM_REQ_CMP_ERR);
335         }
336
337         return (CAM_REQ_CMP);
338 }
339
340 static cam_status
341 targbhdislun(struct cam_periph *periph)
342 {
343         union ccb ccb;
344         struct targbh_softc *softc;
345         struct ccb_accept_tio* atio;
346         struct ccb_hdr *ccb_h;
347
348         softc = (struct targbh_softc *)periph->softc;
349         if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
350                 return CAM_REQ_CMP;
351
352         memset(&ccb, 0, sizeof(ccb));
353
354         /* XXX Block for Continue I/O completion */
355
356         /* Kill off all ACCECPT and IMMEDIATE CCBs */
357         while ((atio = softc->accept_tio_list) != NULL) {
358                 
359                 softc->accept_tio_list =
360                     ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
361                 xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
362                 ccb.cab.ccb_h.func_code = XPT_ABORT;
363                 ccb.cab.abort_ccb = (union ccb *)atio;
364                 xpt_action(&ccb);
365         }
366
367         while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
368                 SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
369                 xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
370                 ccb.cab.ccb_h.func_code = XPT_ABORT;
371                 ccb.cab.abort_ccb = (union ccb *)ccb_h;
372                 xpt_action(&ccb);
373         }
374
375         /*
376          * Dissable this lun.
377          */
378         xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
379         ccb.cel.ccb_h.func_code = XPT_EN_LUN;
380         ccb.cel.enable = 0;
381         xpt_action(&ccb);
382
383         if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
384                 printf("targbhdislun - Disabling lun on controller failed "
385                        "with status 0x%x\n", ccb.cel.ccb_h.status);
386         else 
387                 softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
388         return (ccb.cel.ccb_h.status);
389 }
390
391 static cam_status
392 targbhctor(struct cam_periph *periph, void *arg)
393 {
394         struct targbh_softc *softc;
395
396         /* Allocate our per-instance private storage */
397         softc = (struct targbh_softc *)malloc(sizeof(*softc),
398                                               M_SCSIBH, M_NOWAIT);
399         if (softc == NULL) {
400                 printf("targctor: unable to malloc softc\n");
401                 return (CAM_REQ_CMP_ERR);
402         }
403
404         bzero(softc, sizeof(*softc));
405         TAILQ_INIT(&softc->pending_queue);
406         TAILQ_INIT(&softc->work_queue);
407         softc->accept_tio_list = NULL;
408         SLIST_INIT(&softc->immed_notify_slist);
409         softc->state = TARGBH_STATE_NORMAL;
410         periph->softc = softc;
411         softc->init_level++;
412
413         if (targbhenlun(periph) != CAM_REQ_CMP)
414                 cam_periph_invalidate(periph);
415         return (CAM_REQ_CMP);
416 }
417
418 static void
419 targbhdtor(struct cam_periph *periph)
420 {
421         struct targbh_softc *softc;
422
423         softc = (struct targbh_softc *)periph->softc;
424
425         softc->state = TARGBH_STATE_TEARDOWN;
426
427         targbhdislun(periph);
428
429         switch (softc->init_level) {
430         case 0:
431                 panic("targdtor - impossible init level");
432         case 1:
433                 /* FALLTHROUGH */
434         default:
435                 /* XXX Wait for callback of targbhdislun() */
436                 cam_periph_sleep(periph, softc, PRIBIO, "targbh", hz/2);
437                 free(softc, M_SCSIBH);
438                 break;
439         }
440 }
441
442 static void
443 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
444 {
445         struct targbh_softc *softc;
446         struct ccb_hdr *ccbh;
447         struct ccb_accept_tio *atio;
448         struct targbh_cmd_desc *desc;
449         struct ccb_scsiio *csio;
450         ccb_flags flags;
451
452         softc = (struct targbh_softc *)periph->softc;
453
454         ccbh = TAILQ_FIRST(&softc->work_queue);
455         if (ccbh == NULL) {
456                 xpt_release_ccb(start_ccb);     
457         } else {
458                 TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
459                 TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
460                                   periph_links.tqe);
461                 atio = (struct ccb_accept_tio*)ccbh;
462                 desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
463
464                 /* Is this a tagged request? */
465                 flags = atio->ccb_h.flags &
466                     (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
467
468                 csio = &start_ccb->csio;
469                 /*
470                  * If we are done with the transaction, tell the
471                  * controller to send status and perform a CMD_CMPLT.
472                  * If we have associated sense data, see if we can
473                  * send that too.
474                  */
475                 if (desc->data_resid == desc->data_increment) {
476                         flags |= CAM_SEND_STATUS;
477                         if (atio->sense_len) {
478                                 csio->sense_len = atio->sense_len;
479                                 csio->sense_data = atio->sense_data;
480                                 flags |= CAM_SEND_SENSE;
481                         }
482                 }
483
484                 cam_fill_ctio(csio,
485                               /*retries*/2,
486                               targbhdone,
487                               flags,
488                               (flags & CAM_TAG_ACTION_VALID)?
489                                 MSG_SIMPLE_Q_TAG : 0,
490                               atio->tag_id,
491                               atio->init_id,
492                               desc->status,
493                               /*data_ptr*/desc->data_increment == 0
494                                           ? NULL : desc->data,
495                               /*dxfer_len*/desc->data_increment,
496                               /*timeout*/desc->timeout);
497
498                 /* Override our wildcard attachment */
499                 start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
500                 start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
501
502                 start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
503                 start_ccb->ccb_h.ccb_atio = atio;
504                 CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
505                           ("Sending a CTIO\n"));
506                 xpt_action(start_ccb);
507                 /*
508                  * If the queue was frozen waiting for the response
509                  * to this ATIO (for instance disconnection was disallowed),
510                  * then release it now that our response has been queued.
511                  */
512                 if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
513                         cam_release_devq(periph->path,
514                                          /*relsim_flags*/0,
515                                          /*reduction*/0,
516                                          /*timeout*/0,
517                                          /*getcount_only*/0); 
518                         atio->ccb_h.status &= ~CAM_DEV_QFRZN;
519                 }
520                 ccbh = TAILQ_FIRST(&softc->work_queue);
521         }
522         if (ccbh != NULL)
523                 xpt_schedule(periph, CAM_PRIORITY_NORMAL);
524 }
525
526 static void
527 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
528 {
529         struct targbh_softc *softc;
530
531         softc = (struct targbh_softc *)periph->softc;
532
533         switch (done_ccb->ccb_h.func_code) {
534         case XPT_ACCEPT_TARGET_IO:
535         {
536                 struct ccb_accept_tio *atio;
537                 struct targbh_cmd_desc *descr;
538                 uint8_t *cdb;
539                 int priority;
540
541                 atio = &done_ccb->atio;
542                 descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
543                 cdb = atio->cdb_io.cdb_bytes;
544                 if (softc->state == TARGBH_STATE_TEARDOWN
545                  || atio->ccb_h.status == CAM_REQ_ABORTED) {
546                         targbhfreedescr(descr);
547                         xpt_free_ccb(done_ccb);
548                         return;
549                 }
550
551                 /*
552                  * Determine the type of incoming command and
553                  * setup our buffer for a response.
554                  */
555                 switch (cdb[0]) {
556                 case INQUIRY:
557                 {
558                         struct scsi_inquiry *inq;
559
560                         inq = (struct scsi_inquiry *)cdb;
561                         CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
562                                   ("Saw an inquiry!\n"));
563                         /*
564                          * Validate the command.  We don't
565                          * support any VPD pages, so complain
566                          * if EVPD is set.
567                          */
568                         if ((inq->byte2 & SI_EVPD) != 0
569                          || inq->page_code != 0) {
570                                 atio->ccb_h.flags &= ~CAM_DIR_MASK;
571                                 atio->ccb_h.flags |= CAM_DIR_NONE;
572                                 /*
573                                  * This needs to have other than a
574                                  * no_lun_sense_data response.
575                                  */
576                                 bcopy(&no_lun_sense_data, &atio->sense_data,
577                                       min(sizeof(no_lun_sense_data),
578                                           sizeof(atio->sense_data)));
579                                 atio->sense_len = sizeof(no_lun_sense_data);
580                                 descr->data_resid = 0;
581                                 descr->data_increment = 0;
582                                 descr->status = SCSI_STATUS_CHECK_COND;
583                                 break;
584                         }
585                         /*
586                          * Direction is always relative
587                          * to the initator.
588                          */
589                         atio->ccb_h.flags &= ~CAM_DIR_MASK;
590                         atio->ccb_h.flags |= CAM_DIR_IN;
591                         descr->data = &no_lun_inq_data;
592                         descr->data_resid = MIN(sizeof(no_lun_inq_data),
593                                                 scsi_2btoul(inq->length));
594                         descr->data_increment = descr->data_resid;
595                         descr->timeout = 5 * 1000;
596                         descr->status = SCSI_STATUS_OK;
597                         break;
598                 }
599                 case REQUEST_SENSE:
600                 {
601                         struct scsi_request_sense *rsense;
602
603                         rsense = (struct scsi_request_sense *)cdb;
604                         /* Refer to static sense data */
605                         atio->ccb_h.flags &= ~CAM_DIR_MASK;
606                         atio->ccb_h.flags |= CAM_DIR_IN;
607                         descr->data = &no_lun_sense_data;
608                         descr->data_resid = request_sense_size;
609                         descr->data_resid = MIN(descr->data_resid,
610                                                 SCSI_CDB6_LEN(rsense->length));
611                         descr->data_increment = descr->data_resid;
612                         descr->timeout = 5 * 1000;
613                         descr->status = SCSI_STATUS_OK;
614                         break;
615                 }
616                 default:
617                         /* Constant CA, tell initiator */
618                         /* Direction is always relative to the initator */
619                         atio->ccb_h.flags &= ~CAM_DIR_MASK;
620                         atio->ccb_h.flags |= CAM_DIR_NONE;
621                         bcopy(&no_lun_sense_data, &atio->sense_data,
622                               min(sizeof(no_lun_sense_data),
623                                   sizeof(atio->sense_data)));
624                         atio->sense_len = sizeof (no_lun_sense_data);
625                         descr->data_resid = 0;
626                         descr->data_increment = 0;
627                         descr->timeout = 5 * 1000;
628                         descr->status = SCSI_STATUS_CHECK_COND;
629                         break;
630                 }
631
632                 /* Queue us up to receive a Continue Target I/O ccb. */
633                 if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
634                         TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
635                                           periph_links.tqe);
636                         priority = 0;
637                 } else {
638                         TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
639                                           periph_links.tqe);
640                         priority = CAM_PRIORITY_NORMAL;
641                 }
642                 xpt_schedule(periph, priority);
643                 break;
644         }
645         case XPT_CONT_TARGET_IO:
646         {
647                 struct ccb_accept_tio *atio;
648                 struct targbh_cmd_desc *desc;
649
650                 CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
651                           ("Received completed CTIO\n"));
652                 atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
653                 desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
654
655                 TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
656                              periph_links.tqe);
657
658                 /*
659                  * We could check for CAM_SENT_SENSE bein set here,
660                  * but since we're not maintaining any CA/UA state,
661                  * there's no point.
662                  */
663                 atio->sense_len = 0;
664                 done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
665                 done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
666
667                 /*
668                  * Any errors will not change the data we return,
669                  * so make sure the queue is not left frozen.
670                  * XXX - At some point there may be errors that
671                  *       leave us in a connected state with the
672                  *       initiator...
673                  */
674                 if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
675                         printf("Releasing Queue\n");
676                         cam_release_devq(done_ccb->ccb_h.path,
677                                          /*relsim_flags*/0,
678                                          /*reduction*/0,
679                                          /*timeout*/0,
680                                          /*getcount_only*/0); 
681                         done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
682                 }
683                 desc->data_resid -= desc->data_increment;
684                 xpt_release_ccb(done_ccb);
685                 if (softc->state != TARGBH_STATE_TEARDOWN) {
686                         /*
687                          * Send the original accept TIO back to the
688                          * controller to handle more work.
689                          */
690                         CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
691                                   ("Returning ATIO to target\n"));
692                         /* Restore wildcards */
693                         atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
694                         atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
695                         xpt_action((union ccb *)atio);
696                         break;
697                 } else {
698                         targbhfreedescr(desc);
699                         free(atio, M_SCSIBH);
700                 }
701                 break;
702         }
703         case XPT_IMMEDIATE_NOTIFY:
704         {
705                 int frozen;
706
707                 frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
708                 if (softc->state == TARGBH_STATE_TEARDOWN
709                  || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
710                         printf("Freed an immediate notify\n");
711                         xpt_free_ccb(done_ccb);
712                 } else {
713                         /* Requeue for another immediate event */
714                         xpt_action(done_ccb);
715                 }
716                 if (frozen != 0)
717                         cam_release_devq(periph->path,
718                                          /*relsim_flags*/0,
719                                          /*opening reduction*/0,
720                                          /*timeout*/0,
721                                          /*getcount_only*/0);
722                 break;
723         }
724         default:
725                 panic("targbhdone: Unexpected ccb opcode");
726                 break;
727         }
728 }
729
730 #ifdef NOTYET
731 static int
732 targbherror(union ccb *ccb, uint32_t cam_flags, uint32_t sense_flags)
733 {
734         return 0;
735 }
736 #endif
737
738 static struct targbh_cmd_desc*
739 targbhallocdescr(void)
740 {
741         struct targbh_cmd_desc* descr;
742
743         /* Allocate the targbh_descr structure */
744         descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
745                                                M_SCSIBH, M_NOWAIT);
746         if (descr == NULL)
747                 return (NULL);
748
749         bzero(descr, sizeof(*descr));
750
751         /* Allocate buffer backing store */
752         descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
753         if (descr->backing_store == NULL) {
754                 free(descr, M_SCSIBH);
755                 return (NULL);
756         }
757         descr->max_size = MAX_BUF_SIZE;
758         return (descr);
759 }
760
761 static void
762 targbhfreedescr(struct targbh_cmd_desc *descr)
763 {
764         free(descr->backing_store, M_SCSIBH);
765         free(descr, M_SCSIBH);
766 }