drivers/target/loopback/tcm_loop.c

   1 /*******************************************************************************
   2  *
   3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
   4  * for emulated SAS initiator ports
   5  *
   6  * © Copyright 2011-2013 Datera, Inc.
   7  *
   8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   9  *
  10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  ****************************************************************************/
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/configfs.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_fabric.h>
  37 #include <target/target_core_fabric_configfs.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "tcm_loop.h"
  41
  42 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  43
  44 /* Local pointer to allocated TCM configfs fabric module */
  45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
  46
  47 static struct workqueue_struct *tcm_loop_workqueue;
  48 static struct kmem_cache *tcm_loop_cmd_cache;
  49
  50 static int tcm_loop_hba_no_cnt;
  51
  52 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
  53
  54 /*
  55  * Called from struct target_core_fabric_ops->check_stop_free()
  56  */
  57 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
  58 {
  59         /*
  60          * Do not release struct se_cmd's containing a valid TMR
  61          * pointer.  These will be released directly in tcm_loop_device_reset()
  62          * with transport_generic_free_cmd().
  63          */
  64         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
  65                 return 0;
  66         /*
  67          * Release the struct se_cmd, which will make a callback to release
  68          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
  69          */
  70         transport_generic_free_cmd(se_cmd, 0);
  71         return 1;
  72 }
  73
  74 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
  75 {
  76         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
  77                                 struct tcm_loop_cmd, tl_se_cmd);
  78
  79         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
  80 }
  81
  82 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
  83 {
  84         seq_printf(m, "tcm_loop_proc_info()\n");
  85         return 0;
  86 }
  87
  88 static int tcm_loop_driver_probe(struct device *);
  89 static int tcm_loop_driver_remove(struct device *);
  90
  91 static int pseudo_lld_bus_match(struct device *dev,
  92                                 struct device_driver *dev_driver)
  93 {
  94         return 1;
  95 }
  96
  97 static struct bus_type tcm_loop_lld_bus = {
  98         .name                   = "tcm_loop_bus",
  99         .match                  = pseudo_lld_bus_match,
 100         .probe                  = tcm_loop_driver_probe,
 101         .remove                 = tcm_loop_driver_remove,
 102 };
 103
 104 static struct device_driver tcm_loop_driverfs = {
 105         .name                   = "tcm_loop",
 106         .bus                    = &tcm_loop_lld_bus,
 107 };
 108 /*
 109  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 110  */
 111 struct device *tcm_loop_primary;
 112
 113 /*
 114  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 115  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 116  */
 117 static int tcm_loop_change_queue_depth(
 118         struct scsi_device *sdev,
 119         int depth,
 120         int reason)
 121 {
 122         switch (reason) {
 123         case SCSI_QDEPTH_DEFAULT:
 124                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 125                 break;
 126         case SCSI_QDEPTH_QFULL:
 127                 scsi_track_queue_full(sdev, depth);
 128                 break;
 129         case SCSI_QDEPTH_RAMP_UP:
 130                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 131                 break;
 132         default:
 133                 return -EOPNOTSUPP;
 134         }
 135         return sdev->queue_depth;
 136 }
 137
 138 static int tcm_loop_change_queue_type(struct scsi_device *sdev, int tag)
 139 {
 140         if (sdev->tagged_supported) {
 141                 scsi_set_tag_type(sdev, tag);
 142
 143                 if (tag)
 144                         scsi_activate_tcq(sdev, sdev->queue_depth);
 145                 else
 146                         scsi_deactivate_tcq(sdev, sdev->queue_depth);
 147         } else
 148                 tag = 0;
 149
 150         return tag;
 151 }
 152
 153 /*
 154  * Locate the SAM Task Attr from struct scsi_cmnd *
 155  */
 156 static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
 157 {
 158         if (sc->device->tagged_supported) {
 159                 switch (sc->tag) {
 160                 case HEAD_OF_QUEUE_TAG:
 161                         return MSG_HEAD_TAG;
 162                 case ORDERED_QUEUE_TAG:
 163                         return MSG_ORDERED_TAG;
 164                 default:
 165                         break;
 166                 }
 167         }
 168
 169         return MSG_SIMPLE_TAG;
 170 }
 171
 172 static void tcm_loop_submission_work(struct work_struct *work)
 173 {
 174         struct tcm_loop_cmd *tl_cmd =
 175                 container_of(work, struct tcm_loop_cmd, work);
 176         struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
 177         struct scsi_cmnd *sc = tl_cmd->sc;
 178         struct tcm_loop_nexus *tl_nexus;
 179         struct tcm_loop_hba *tl_hba;
 180         struct tcm_loop_tpg *tl_tpg;
 181         struct scatterlist *sgl_bidi = NULL;
 182         u32 sgl_bidi_count = 0, transfer_length;
 183         int rc;
 184
 185         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 186         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 187
 188         /*
 189          * Ensure that this tl_tpg reference from the incoming sc->device->id
 190          * has already been configured via tcm_loop_make_naa_tpg().
 191          */
 192         if (!tl_tpg->tl_hba) {
 193                 set_host_byte(sc, DID_NO_CONNECT);
 194                 goto out_done;
 195         }
 196         if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
 197                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 198                 goto out_done;
 199         }
 200         tl_nexus = tl_hba->tl_nexus;
 201         if (!tl_nexus) {
 202                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
 203                                 " does not exist\n");
 204                 set_host_byte(sc, DID_ERROR);
 205                 goto out_done;
 206         }
 207         if (scsi_bidi_cmnd(sc)) {
 208                 struct scsi_data_buffer *sdb = scsi_in(sc);
 209
 210                 sgl_bidi = sdb->table.sgl;
 211                 sgl_bidi_count = sdb->table.nents;
 212                 se_cmd->se_cmd_flags |= SCF_BIDI;
 213
 214         }
 215
 216         transfer_length = scsi_transfer_length(sc);
 217         if (!scsi_prot_sg_count(sc) &&
 218             scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
 219                 se_cmd->prot_pto = true;
 220                 /*
 221                  * loopback transport doesn't support
 222                  * WRITE_GENERATE, READ_STRIP protection
 223                  * information operations, go ahead unprotected.
 224                  */
 225                 transfer_length = scsi_bufflen(sc);
 226         }
 227
 228         rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
 229                         &tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
 230                         transfer_length, tcm_loop_sam_attr(sc),
 231                         sc->sc_data_direction, 0,
 232                         scsi_sglist(sc), scsi_sg_count(sc),
 233                         sgl_bidi, sgl_bidi_count,
 234                         scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
 235         if (rc < 0) {
 236                 set_host_byte(sc, DID_NO_CONNECT);
 237                 goto out_done;
 238         }
 239         return;
 240
 241 out_done:
 242         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 243         sc->scsi_done(sc);
 244         return;
 245 }
 246
 247 /*
 248  * ->queuecommand can be and usually is called from interrupt context, so
 249  * defer the actual submission to a workqueue.
 250  */
 251 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 252 {
 253         struct tcm_loop_cmd *tl_cmd;
 254
 255         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%llu got CDB: 0x%02x"
 256                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 257                 sc->device->id, sc->device->channel, sc->device->lun,
 258                 sc->cmnd[0], scsi_bufflen(sc));
 259
 260         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
 261         if (!tl_cmd) {
 262                 pr_err("Unable to allocate struct tcm_loop_cmd\n");
 263                 set_host_byte(sc, DID_ERROR);
 264                 sc->scsi_done(sc);
 265                 return 0;
 266         }
 267
 268         tl_cmd->sc = sc;
 269         tl_cmd->sc_cmd_tag = sc->tag;
 270         INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
 271         queue_work(tcm_loop_workqueue, &tl_cmd->work);
 272         return 0;
 273 }
 274
 275 /*
 276  * Called from SCSI EH process context to issue a LUN_RESET TMR
 277  * to struct scsi_device
 278  */
 279 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 280                               struct tcm_loop_nexus *tl_nexus,
 281                               int lun, int task, enum tcm_tmreq_table tmr)
 282 {
 283         struct se_cmd *se_cmd = NULL;
 284         struct se_session *se_sess;
 285         struct se_portal_group *se_tpg;
 286         struct tcm_loop_cmd *tl_cmd = NULL;
 287         struct tcm_loop_tmr *tl_tmr = NULL;
 288         int ret = TMR_FUNCTION_FAILED, rc;
 289
 290         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 291         if (!tl_cmd) {
 292                 pr_err("Unable to allocate memory for tl_cmd\n");
 293                 return ret;
 294         }
 295
 296         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 297         if (!tl_tmr) {
 298                 pr_err("Unable to allocate memory for tl_tmr\n");
 299                 goto release;
 300         }
 301         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 302
 303         se_cmd = &tl_cmd->tl_se_cmd;
 304         se_tpg = &tl_tpg->tl_se_tpg;
 305         se_sess = tl_nexus->se_sess;
 306         /*
 307          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 308          */
 309         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 310                                 DMA_NONE, MSG_SIMPLE_TAG,
 311                                 &tl_cmd->tl_sense_buf[0]);
 312
 313         rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
 314         if (rc < 0)
 315                 goto release;
 316
 317         if (tmr == TMR_ABORT_TASK)
 318                 se_cmd->se_tmr_req->ref_task_tag = task;
 319
 320         /*
 321          * Locate the underlying TCM struct se_lun
 322          */
 323         if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
 324                 ret = TMR_LUN_DOES_NOT_EXIST;
 325                 goto release;
 326         }
 327         /*
 328          * Queue the TMR to TCM Core and sleep waiting for
 329          * tcm_loop_queue_tm_rsp() to wake us up.
 330          */
 331         transport_generic_handle_tmr(se_cmd);
 332         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 333         /*
 334          * The TMR LUN_RESET has completed, check the response status and
 335          * then release allocations.
 336          */
 337         ret = se_cmd->se_tmr_req->response;
 338 release:
 339         if (se_cmd)
 340                 transport_generic_free_cmd(se_cmd, 1);
 341         else
 342                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 343         kfree(tl_tmr);
 344         return ret;
 345 }
 346
 347 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 348 {
 349         struct tcm_loop_hba *tl_hba;
 350         struct tcm_loop_nexus *tl_nexus;
 351         struct tcm_loop_tpg *tl_tpg;
 352         int ret = FAILED;
 353
 354         /*
 355          * Locate the tcm_loop_hba_t pointer
 356          */
 357         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 358         /*
 359          * Locate the tl_nexus and se_sess pointers
 360          */
 361         tl_nexus = tl_hba->tl_nexus;
 362         if (!tl_nexus) {
 363                 pr_err("Unable to perform device reset without"
 364                                 " active I_T Nexus\n");
 365                 return FAILED;
 366         }
 367
 368         /*
 369          * Locate the tl_tpg pointer from TargetID in sc->device->id
 370          */
 371         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 372         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 373                                  sc->tag, TMR_ABORT_TASK);
 374         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 375 }
 376
 377 /*
 378  * Called from SCSI EH process context to issue a LUN_RESET TMR
 379  * to struct scsi_device
 380  */
 381 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 382 {
 383         struct tcm_loop_hba *tl_hba;
 384         struct tcm_loop_nexus *tl_nexus;
 385         struct tcm_loop_tpg *tl_tpg;
 386         int ret = FAILED;
 387
 388         /*
 389          * Locate the tcm_loop_hba_t pointer
 390          */
 391         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 392         /*
 393          * Locate the tl_nexus and se_sess pointers
 394          */
 395         tl_nexus = tl_hba->tl_nexus;
 396         if (!tl_nexus) {
 397                 pr_err("Unable to perform device reset without"
 398                                 " active I_T Nexus\n");
 399                 return FAILED;
 400         }
 401         /*
 402          * Locate the tl_tpg pointer from TargetID in sc->device->id
 403          */
 404         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 405         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 406                                  0, TMR_LUN_RESET);
 407         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 408 }
 409
 410 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 411 {
 412         struct tcm_loop_hba *tl_hba;
 413         struct tcm_loop_tpg *tl_tpg;
 414
 415         /*
 416          * Locate the tcm_loop_hba_t pointer
 417          */
 418         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 419         if (!tl_hba) {
 420                 pr_err("Unable to perform device reset without"
 421                                 " active I_T Nexus\n");
 422                 return FAILED;
 423         }
 424         /*
 425          * Locate the tl_tpg pointer from TargetID in sc->device->id
 426          */
 427         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 428         if (tl_tpg) {
 429                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 430                 return SUCCESS;
 431         }
 432         return FAILED;
 433 }
 434
 435 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 436 {
 437         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 438         return 0;
 439 }
 440
 441 static int tcm_loop_slave_configure(struct scsi_device *sd)
 442 {
 443         if (sd->tagged_supported) {
 444                 scsi_activate_tcq(sd, sd->queue_depth);
 445                 scsi_adjust_queue_depth(sd, MSG_SIMPLE_TAG,
 446                                         sd->host->cmd_per_lun);
 447         } else {
 448                 scsi_adjust_queue_depth(sd, 0,
 449                                         sd->host->cmd_per_lun);
 450         }
 451
 452         return 0;
 453 }
 454
 455 static struct scsi_host_template tcm_loop_driver_template = {
 456         .show_info              = tcm_loop_show_info,
 457         .proc_name              = "tcm_loopback",
 458         .name                   = "TCM_Loopback",
 459         .queuecommand           = tcm_loop_queuecommand,
 460         .change_queue_depth     = tcm_loop_change_queue_depth,
 461         .change_queue_type      = tcm_loop_change_queue_type,
 462         .eh_abort_handler = tcm_loop_abort_task,
 463         .eh_device_reset_handler = tcm_loop_device_reset,
 464         .eh_target_reset_handler = tcm_loop_target_reset,
 465         .can_queue              = 1024,
 466         .this_id                = -1,
 467         .sg_tablesize           = 256,
 468         .cmd_per_lun            = 1024,
 469         .max_sectors            = 0xFFFF,
 470         .use_clustering         = DISABLE_CLUSTERING,
 471         .slave_alloc            = tcm_loop_slave_alloc,
 472         .slave_configure        = tcm_loop_slave_configure,
 473         .module                 = THIS_MODULE,
 474 };
 475
 476 static int tcm_loop_driver_probe(struct device *dev)
 477 {
 478         struct tcm_loop_hba *tl_hba;
 479         struct Scsi_Host *sh;
 480         int error, host_prot;
 481
 482         tl_hba = to_tcm_loop_hba(dev);
 483
 484         sh = scsi_host_alloc(&tcm_loop_driver_template,
 485                         sizeof(struct tcm_loop_hba));
 486         if (!sh) {
 487                 pr_err("Unable to allocate struct scsi_host\n");
 488                 return -ENODEV;
 489         }
 490         tl_hba->sh = sh;
 491
 492         /*
 493          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 494          */
 495         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 496         /*
 497          * Setup single ID, Channel and LUN for now..
 498          */
 499         sh->max_id = 2;
 500         sh->max_lun = 0;
 501         sh->max_channel = 0;
 502         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 503
 504         host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
 505                     SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
 506                     SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
 507
 508         scsi_host_set_prot(sh, host_prot);
 509         scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
 510
 511         error = scsi_add_host(sh, &tl_hba->dev);
 512         if (error) {
 513                 pr_err("%s: scsi_add_host failed\n", __func__);
 514                 scsi_host_put(sh);
 515                 return -ENODEV;
 516         }
 517         return 0;
 518 }
 519
 520 static int tcm_loop_driver_remove(struct device *dev)
 521 {
 522         struct tcm_loop_hba *tl_hba;
 523         struct Scsi_Host *sh;
 524
 525         tl_hba = to_tcm_loop_hba(dev);
 526         sh = tl_hba->sh;
 527
 528         scsi_remove_host(sh);
 529         scsi_host_put(sh);
 530         return 0;
 531 }
 532
 533 static void tcm_loop_release_adapter(struct device *dev)
 534 {
 535         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 536
 537         kfree(tl_hba);
 538 }
 539
 540 /*
 541  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 542  */
 543 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 544 {
 545         int ret;
 546
 547         tl_hba->dev.bus = &tcm_loop_lld_bus;
 548         tl_hba->dev.parent = tcm_loop_primary;
 549         tl_hba->dev.release = &tcm_loop_release_adapter;
 550         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 551
 552         ret = device_register(&tl_hba->dev);
 553         if (ret) {
 554                 pr_err("device_register() failed for"
 555                                 " tl_hba->dev: %d\n", ret);
 556                 return -ENODEV;
 557         }
 558
 559         return 0;
 560 }
 561
 562 /*
 563  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 564  * tcm_loop SCSI bus.
 565  */
 566 static int tcm_loop_alloc_core_bus(void)
 567 {
 568         int ret;
 569
 570         tcm_loop_primary = root_device_register("tcm_loop_0");
 571         if (IS_ERR(tcm_loop_primary)) {
 572                 pr_err("Unable to allocate tcm_loop_primary\n");
 573                 return PTR_ERR(tcm_loop_primary);
 574         }
 575
 576         ret = bus_register(&tcm_loop_lld_bus);
 577         if (ret) {
 578                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 579                 goto dev_unreg;
 580         }
 581
 582         ret = driver_register(&tcm_loop_driverfs);
 583         if (ret) {
 584                 pr_err("driver_register() failed for"
 585                                 "tcm_loop_driverfs\n");
 586                 goto bus_unreg;
 587         }
 588
 589         pr_debug("Initialized TCM Loop Core Bus\n");
 590         return ret;
 591
 592 bus_unreg:
 593         bus_unregister(&tcm_loop_lld_bus);
 594 dev_unreg:
 595         root_device_unregister(tcm_loop_primary);
 596         return ret;
 597 }
 598
 599 static void tcm_loop_release_core_bus(void)
 600 {
 601         driver_unregister(&tcm_loop_driverfs);
 602         bus_unregister(&tcm_loop_lld_bus);
 603         root_device_unregister(tcm_loop_primary);
 604
 605         pr_debug("Releasing TCM Loop Core BUS\n");
 606 }
 607
 608 static char *tcm_loop_get_fabric_name(void)
 609 {
 610         return "loopback";
 611 }
 612
 613 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 614 {
 615         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 616         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 617         /*
 618          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 619          * time based on the protocol dependent prefix of the passed configfs group.
 620          *
 621          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 622          * ProtocolID using target_core_fabric_lib.c symbols.
 623          */
 624         switch (tl_hba->tl_proto_id) {
 625         case SCSI_PROTOCOL_SAS:
 626                 return sas_get_fabric_proto_ident(se_tpg);
 627         case SCSI_PROTOCOL_FCP:
 628                 return fc_get_fabric_proto_ident(se_tpg);
 629         case SCSI_PROTOCOL_ISCSI:
 630                 return iscsi_get_fabric_proto_ident(se_tpg);
 631         default:
 632                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 633                         " SAS emulation\n", tl_hba->tl_proto_id);
 634                 break;
 635         }
 636
 637         return sas_get_fabric_proto_ident(se_tpg);
 638 }
 639
 640 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 641 {
 642         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 643         /*
 644          * Return the passed NAA identifier for the SAS Target Port
 645          */
 646         return &tl_tpg->tl_hba->tl_wwn_address[0];
 647 }
 648
 649 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 650 {
 651         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 652         /*
 653          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 654          * to represent the SCSI Target Port.
 655          */
 656         return tl_tpg->tl_tpgt;
 657 }
 658
 659 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 660 {
 661         return 1;
 662 }
 663
 664 static u32 tcm_loop_get_pr_transport_id(
 665         struct se_portal_group *se_tpg,
 666         struct se_node_acl *se_nacl,
 667         struct t10_pr_registration *pr_reg,
 668         int *format_code,
 669         unsigned char *buf)
 670 {
 671         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 672         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 673
 674         switch (tl_hba->tl_proto_id) {
 675         case SCSI_PROTOCOL_SAS:
 676                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 677                                         format_code, buf);
 678         case SCSI_PROTOCOL_FCP:
 679                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 680                                         format_code, buf);
 681         case SCSI_PROTOCOL_ISCSI:
 682                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 683                                         format_code, buf);
 684         default:
 685                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 686                         " SAS emulation\n", tl_hba->tl_proto_id);
 687                 break;
 688         }
 689
 690         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 691                         format_code, buf);
 692 }
 693
 694 static u32 tcm_loop_get_pr_transport_id_len(
 695         struct se_portal_group *se_tpg,
 696         struct se_node_acl *se_nacl,
 697         struct t10_pr_registration *pr_reg,
 698         int *format_code)
 699 {
 700         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 701         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 702
 703         switch (tl_hba->tl_proto_id) {
 704         case SCSI_PROTOCOL_SAS:
 705                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 706                                         format_code);
 707         case SCSI_PROTOCOL_FCP:
 708                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 709                                         format_code);
 710         case SCSI_PROTOCOL_ISCSI:
 711                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 712                                         format_code);
 713         default:
 714                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 715                         " SAS emulation\n", tl_hba->tl_proto_id);
 716                 break;
 717         }
 718
 719         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 720                         format_code);
 721 }
 722
 723 /*
 724  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 725  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 726  */
 727 static char *tcm_loop_parse_pr_out_transport_id(
 728         struct se_portal_group *se_tpg,
 729         const char *buf,
 730         u32 *out_tid_len,
 731         char **port_nexus_ptr)
 732 {
 733         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 734         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 735
 736         switch (tl_hba->tl_proto_id) {
 737         case SCSI_PROTOCOL_SAS:
 738                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 739                                         port_nexus_ptr);
 740         case SCSI_PROTOCOL_FCP:
 741                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 742                                         port_nexus_ptr);
 743         case SCSI_PROTOCOL_ISCSI:
 744                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 745                                         port_nexus_ptr);
 746         default:
 747                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 748                         " SAS emulation\n", tl_hba->tl_proto_id);
 749                 break;
 750         }
 751
 752         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 753                         port_nexus_ptr);
 754 }
 755
 756 /*
 757  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 758  * based upon the incoming fabric dependent SCSI Initiator Port
 759  */
 760 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 761 {
 762         return 1;
 763 }
 764
 765 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 766 {
 767         return 0;
 768 }
 769
 770 /*
 771  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 772  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 773  */
 774 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 775 {
 776         return 0;
 777 }
 778
 779 /*
 780  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 781  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 782  * It has been added here as a nop for target_fabric_tf_ops_check()
 783  */
 784 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 785 {
 786         return 0;
 787 }
 788
 789 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 790         struct se_portal_group *se_tpg)
 791 {
 792         struct tcm_loop_nacl *tl_nacl;
 793
 794         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 795         if (!tl_nacl) {
 796                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 797                 return NULL;
 798         }
 799
 800         return &tl_nacl->se_node_acl;
 801 }
 802
 803 static void tcm_loop_tpg_release_fabric_acl(
 804         struct se_portal_group *se_tpg,
 805         struct se_node_acl *se_nacl)
 806 {
 807         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 808                                 struct tcm_loop_nacl, se_node_acl);
 809
 810         kfree(tl_nacl);
 811 }
 812
 813 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 814 {
 815         return 1;
 816 }
 817
 818 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 819 {
 820         return 1;
 821 }
 822
 823 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 824 {
 825         return;
 826 }
 827
 828 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 829 {
 830         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 831                         struct tcm_loop_cmd, tl_se_cmd);
 832
 833         return tl_cmd->sc_cmd_tag;
 834 }
 835
 836 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 837 {
 838         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 839                         struct tcm_loop_cmd, tl_se_cmd);
 840
 841         return tl_cmd->sc_cmd_state;
 842 }
 843
 844 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 845 {
 846         return 0;
 847 }
 848
 849 static void tcm_loop_close_session(struct se_session *se_sess)
 850 {
 851         return;
 852 };
 853
 854 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 855 {
 856         /*
 857          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 858          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 859          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 860          * format with transport_generic_map_mem_to_cmd().
 861          *
 862          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 863          * object execution queue.
 864          */
 865         target_execute_cmd(se_cmd);
 866         return 0;
 867 }
 868
 869 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 870 {
 871         return 0;
 872 }
 873
 874 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 875 {
 876         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 877                                 struct tcm_loop_cmd, tl_se_cmd);
 878         struct scsi_cmnd *sc = tl_cmd->sc;
 879
 880         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 881                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 882
 883         sc->result = SAM_STAT_GOOD;
 884         set_host_byte(sc, DID_OK);
 885         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 886             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 887                 scsi_set_resid(sc, se_cmd->residual_count);
 888         sc->scsi_done(sc);
 889         return 0;
 890 }
 891
 892 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 893 {
 894         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 895                                 struct tcm_loop_cmd, tl_se_cmd);
 896         struct scsi_cmnd *sc = tl_cmd->sc;
 897
 898         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 899                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 900
 901         if (se_cmd->sense_buffer &&
 902            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 903             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 904
 905                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 906                                 SCSI_SENSE_BUFFERSIZE);
 907                 sc->result = SAM_STAT_CHECK_CONDITION;
 908                 set_driver_byte(sc, DRIVER_SENSE);
 909         } else
 910                 sc->result = se_cmd->scsi_status;
 911
 912         set_host_byte(sc, DID_OK);
 913         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 914             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 915                 scsi_set_resid(sc, se_cmd->residual_count);
 916         sc->scsi_done(sc);
 917         return 0;
 918 }
 919
 920 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 921 {
 922         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 923         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 924         /*
 925          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 926          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 927          */
 928         atomic_set(&tl_tmr->tmr_complete, 1);
 929         wake_up(&tl_tmr->tl_tmr_wait);
 930 }
 931
 932 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
 933 {
 934         return;
 935 }
 936
 937 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 938 {
 939         switch (tl_hba->tl_proto_id) {
 940         case SCSI_PROTOCOL_SAS:
 941                 return "SAS";
 942         case SCSI_PROTOCOL_FCP:
 943                 return "FCP";
 944         case SCSI_PROTOCOL_ISCSI:
 945                 return "iSCSI";
 946         default:
 947                 break;
 948         }
 949
 950         return "Unknown";
 951 }
 952
 953 /* Start items for tcm_loop_port_cit */
 954
 955 static int tcm_loop_port_link(
 956         struct se_portal_group *se_tpg,
 957         struct se_lun *lun)
 958 {
 959         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 960                                 struct tcm_loop_tpg, tl_se_tpg);
 961         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 962
 963         atomic_inc(&tl_tpg->tl_tpg_port_count);
 964         smp_mb__after_atomic();
 965         /*
 966          * Add Linux/SCSI struct scsi_device by HCTL
 967          */
 968         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 969
 970         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 971         return 0;
 972 }
 973
 974 static void tcm_loop_port_unlink(
 975         struct se_portal_group *se_tpg,
 976         struct se_lun *se_lun)
 977 {
 978         struct scsi_device *sd;
 979         struct tcm_loop_hba *tl_hba;
 980         struct tcm_loop_tpg *tl_tpg;
 981
 982         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 983         tl_hba = tl_tpg->tl_hba;
 984
 985         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 986                                 se_lun->unpacked_lun);
 987         if (!sd) {
 988                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 989                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 990                 return;
 991         }
 992         /*
 993          * Remove Linux/SCSI struct scsi_device by HCTL
 994          */
 995         scsi_remove_device(sd);
 996         scsi_device_put(sd);
 997
 998         atomic_dec(&tl_tpg->tl_tpg_port_count);
 999         smp_mb__after_atomic();
1000
1001         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
1002 }
1003
1004 /* End items for tcm_loop_port_cit */
1005
1006 /* Start items for tcm_loop_nexus_cit */
1007
1008 static int tcm_loop_make_nexus(
1009         struct tcm_loop_tpg *tl_tpg,
1010         const char *name)
1011 {
1012         struct se_portal_group *se_tpg;
1013         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1014         struct tcm_loop_nexus *tl_nexus;
1015         int ret = -ENOMEM;
1016
1017         if (tl_tpg->tl_hba->tl_nexus) {
1018                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
1019                 return -EEXIST;
1020         }
1021         se_tpg = &tl_tpg->tl_se_tpg;
1022
1023         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1024         if (!tl_nexus) {
1025                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
1026                 return -ENOMEM;
1027         }
1028         /*
1029          * Initialize the struct se_session pointer
1030          */
1031         tl_nexus->se_sess = transport_init_session(TARGET_PROT_ALL);
1032         if (IS_ERR(tl_nexus->se_sess)) {
1033                 ret = PTR_ERR(tl_nexus->se_sess);
1034                 goto out;
1035         }
1036         /*
1037          * Since we are running in 'demo mode' this call with generate a
1038          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1039          * Initiator port name of the passed configfs group 'name'.
1040          */
1041         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1042                                 se_tpg, (unsigned char *)name);
1043         if (!tl_nexus->se_sess->se_node_acl) {
1044                 transport_free_session(tl_nexus->se_sess);
1045                 goto out;
1046         }
1047         /*
1048          * Now, register the SAS I_T Nexus as active with the call to
1049          * transport_register_session()
1050          */
1051         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1052                         tl_nexus->se_sess, tl_nexus);
1053         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1054         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1055                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1056                 name);
1057         return 0;
1058
1059 out:
1060         kfree(tl_nexus);
1061         return ret;
1062 }
1063
1064 static int tcm_loop_drop_nexus(
1065         struct tcm_loop_tpg *tpg)
1066 {
1067         struct se_session *se_sess;
1068         struct tcm_loop_nexus *tl_nexus;
1069         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1070
1071         if (!tl_hba)
1072                 return -ENODEV;
1073
1074         tl_nexus = tl_hba->tl_nexus;
1075         if (!tl_nexus)
1076                 return -ENODEV;
1077
1078         se_sess = tl_nexus->se_sess;
1079         if (!se_sess)
1080                 return -ENODEV;
1081
1082         if (atomic_read(&tpg->tl_tpg_port_count)) {
1083                 pr_err("Unable to remove TCM_Loop I_T Nexus with"
1084                         " active TPG port count: %d\n",
1085                         atomic_read(&tpg->tl_tpg_port_count));
1086                 return -EPERM;
1087         }
1088
1089         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1090                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1091                 tl_nexus->se_sess->se_node_acl->initiatorname);
1092         /*
1093          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1094          */
1095         transport_deregister_session(tl_nexus->se_sess);
1096         tpg->tl_hba->tl_nexus = NULL;
1097         kfree(tl_nexus);
1098         return 0;
1099 }
1100
1101 /* End items for tcm_loop_nexus_cit */
1102
1103 static ssize_t tcm_loop_tpg_show_nexus(
1104         struct se_portal_group *se_tpg,
1105         char *page)
1106 {
1107         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1108                         struct tcm_loop_tpg, tl_se_tpg);
1109         struct tcm_loop_nexus *tl_nexus;
1110         ssize_t ret;
1111
1112         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1113         if (!tl_nexus)
1114                 return -ENODEV;
1115
1116         ret = snprintf(page, PAGE_SIZE, "%s\n",
1117                 tl_nexus->se_sess->se_node_acl->initiatorname);
1118
1119         return ret;
1120 }
1121
1122 static ssize_t tcm_loop_tpg_store_nexus(
1123         struct se_portal_group *se_tpg,
1124         const char *page,
1125         size_t count)
1126 {
1127         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1128                         struct tcm_loop_tpg, tl_se_tpg);
1129         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1130         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1131         int ret;
1132         /*
1133          * Shutdown the active I_T nexus if 'NULL' is passed..
1134          */
1135         if (!strncmp(page, "NULL", 4)) {
1136                 ret = tcm_loop_drop_nexus(tl_tpg);
1137                 return (!ret) ? count : ret;
1138         }
1139         /*
1140          * Otherwise make sure the passed virtual Initiator port WWN matches
1141          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1142          * tcm_loop_make_nexus()
1143          */
1144         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1145                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1146                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1147                 return -EINVAL;
1148         }
1149         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1150
1151         ptr = strstr(i_port, "naa.");
1152         if (ptr) {
1153                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1154                         pr_err("Passed SAS Initiator Port %s does not"
1155                                 " match target port protoid: %s\n", i_port,
1156                                 tcm_loop_dump_proto_id(tl_hba));
1157                         return -EINVAL;
1158                 }
1159                 port_ptr = &i_port[0];
1160                 goto check_newline;
1161         }
1162         ptr = strstr(i_port, "fc.");
1163         if (ptr) {
1164                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1165                         pr_err("Passed FCP Initiator Port %s does not"
1166                                 " match target port protoid: %s\n", i_port,
1167                                 tcm_loop_dump_proto_id(tl_hba));
1168                         return -EINVAL;
1169                 }
1170                 port_ptr = &i_port[3]; /* Skip over "fc." */
1171                 goto check_newline;
1172         }
1173         ptr = strstr(i_port, "iqn.");
1174         if (ptr) {
1175                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1176                         pr_err("Passed iSCSI Initiator Port %s does not"
1177                                 " match target port protoid: %s\n", i_port,
1178                                 tcm_loop_dump_proto_id(tl_hba));
1179                         return -EINVAL;
1180                 }
1181                 port_ptr = &i_port[0];
1182                 goto check_newline;
1183         }
1184         pr_err("Unable to locate prefix for emulated Initiator Port:"
1185                         " %s\n", i_port);
1186         return -EINVAL;
1187         /*
1188          * Clear any trailing newline for the NAA WWN
1189          */
1190 check_newline:
1191         if (i_port[strlen(i_port)-1] == '\n')
1192                 i_port[strlen(i_port)-1] = '\0';
1193
1194         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1195         if (ret < 0)
1196                 return ret;
1197
1198         return count;
1199 }
1200
1201 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1202
1203 static ssize_t tcm_loop_tpg_show_transport_status(
1204         struct se_portal_group *se_tpg,
1205         char *page)
1206 {
1207         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1208                         struct tcm_loop_tpg, tl_se_tpg);
1209         const char *status = NULL;
1210         ssize_t ret = -EINVAL;
1211
1212         switch (tl_tpg->tl_transport_status) {
1213         case TCM_TRANSPORT_ONLINE:
1214                 status = "online";
1215                 break;
1216         case TCM_TRANSPORT_OFFLINE:
1217                 status = "offline";
1218                 break;
1219         default:
1220                 break;
1221         }
1222
1223         if (status)
1224                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1225
1226         return ret;
1227 }
1228
1229 static ssize_t tcm_loop_tpg_store_transport_status(
1230         struct se_portal_group *se_tpg,
1231         const char *page,
1232         size_t count)
1233 {
1234         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1235                         struct tcm_loop_tpg, tl_se_tpg);
1236
1237         if (!strncmp(page, "online", 6)) {
1238                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1239                 return count;
1240         }
1241         if (!strncmp(page, "offline", 7)) {
1242                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1243                 return count;
1244         }
1245         return -EINVAL;
1246 }
1247
1248 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1249
1250 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1251         &tcm_loop_tpg_nexus.attr,
1252         &tcm_loop_tpg_transport_status.attr,
1253         NULL,
1254 };
1255
1256 /* Start items for tcm_loop_naa_cit */
1257
1258 static struct se_portal_group *tcm_loop_make_naa_tpg(
1259         struct se_wwn *wwn,
1260         struct config_group *group,
1261         const char *name)
1262 {
1263         struct tcm_loop_hba *tl_hba = container_of(wwn,
1264                         struct tcm_loop_hba, tl_hba_wwn);
1265         struct tcm_loop_tpg *tl_tpg;
1266         char *tpgt_str, *end_ptr;
1267         int ret;
1268         unsigned short int tpgt;
1269
1270         tpgt_str = strstr(name, "tpgt_");
1271         if (!tpgt_str) {
1272                 pr_err("Unable to locate \"tpgt_#\" directory"
1273                                 " group\n");
1274                 return ERR_PTR(-EINVAL);
1275         }
1276         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1277         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1278
1279         if (tpgt >= TL_TPGS_PER_HBA) {
1280                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1281                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1282                 return ERR_PTR(-EINVAL);
1283         }
1284         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1285         tl_tpg->tl_hba = tl_hba;
1286         tl_tpg->tl_tpgt = tpgt;
1287         /*
1288          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1289          */
1290         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1291                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1292                         TRANSPORT_TPG_TYPE_NORMAL);
1293         if (ret < 0)
1294                 return ERR_PTR(-ENOMEM);
1295
1296         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1297                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1298                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1299
1300         return &tl_tpg->tl_se_tpg;
1301 }
1302
1303 static void tcm_loop_drop_naa_tpg(
1304         struct se_portal_group *se_tpg)
1305 {
1306         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1307         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1308                                 struct tcm_loop_tpg, tl_se_tpg);
1309         struct tcm_loop_hba *tl_hba;
1310         unsigned short tpgt;
1311
1312         tl_hba = tl_tpg->tl_hba;
1313         tpgt = tl_tpg->tl_tpgt;
1314         /*
1315          * Release the I_T Nexus for the Virtual SAS link if present
1316          */
1317         tcm_loop_drop_nexus(tl_tpg);
1318         /*
1319          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1320          */
1321         core_tpg_deregister(se_tpg);
1322
1323         tl_tpg->tl_hba = NULL;
1324         tl_tpg->tl_tpgt = 0;
1325
1326         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1327                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1328                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1329 }
1330
1331 /* End items for tcm_loop_naa_cit */
1332
1333 /* Start items for tcm_loop_cit */
1334
1335 static struct se_wwn *tcm_loop_make_scsi_hba(
1336         struct target_fabric_configfs *tf,
1337         struct config_group *group,
1338         const char *name)
1339 {
1340         struct tcm_loop_hba *tl_hba;
1341         struct Scsi_Host *sh;
1342         char *ptr;
1343         int ret, off = 0;
1344
1345         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1346         if (!tl_hba) {
1347                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1348                 return ERR_PTR(-ENOMEM);
1349         }
1350         /*
1351          * Determine the emulated Protocol Identifier and Target Port Name
1352          * based on the incoming configfs directory name.
1353          */
1354         ptr = strstr(name, "naa.");
1355         if (ptr) {
1356                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1357                 goto check_len;
1358         }
1359         ptr = strstr(name, "fc.");
1360         if (ptr) {
1361                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1362                 off = 3; /* Skip over "fc." */
1363                 goto check_len;
1364         }
1365         ptr = strstr(name, "iqn.");
1366         if (!ptr) {
1367                 pr_err("Unable to locate prefix for emulated Target "
1368                                 "Port: %s\n", name);
1369                 ret = -EINVAL;
1370                 goto out;
1371         }
1372         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1373
1374 check_len:
1375         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1376                 pr_err("Emulated NAA %s Address: %s, exceeds"
1377                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1378                         TL_WWN_ADDR_LEN);
1379                 ret = -EINVAL;
1380                 goto out;
1381         }
1382         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1383
1384         /*
1385          * Call device_register(tl_hba->dev) to register the emulated
1386          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1387          * device_register() callbacks in tcm_loop_driver_probe()
1388          */
1389         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1390         if (ret)
1391                 goto out;
1392
1393         sh = tl_hba->sh;
1394         tcm_loop_hba_no_cnt++;
1395         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1396                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1397                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1398
1399         return &tl_hba->tl_hba_wwn;
1400 out:
1401         kfree(tl_hba);
1402         return ERR_PTR(ret);
1403 }
1404
1405 static void tcm_loop_drop_scsi_hba(
1406         struct se_wwn *wwn)
1407 {
1408         struct tcm_loop_hba *tl_hba = container_of(wwn,
1409                                 struct tcm_loop_hba, tl_hba_wwn);
1410
1411         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1412                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1413                 tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1414         /*
1415          * Call device_unregister() on the original tl_hba->dev.
1416          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1417          * release *tl_hba;
1418          */
1419         device_unregister(&tl_hba->dev);
1420 }
1421
1422 /* Start items for tcm_loop_cit */
1423 static ssize_t tcm_loop_wwn_show_attr_version(
1424         struct target_fabric_configfs *tf,
1425         char *page)
1426 {
1427         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1428 }
1429
1430 TF_WWN_ATTR_RO(tcm_loop, version);
1431
1432 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1433         &tcm_loop_wwn_version.attr,
1434         NULL,
1435 };
1436
1437 /* End items for tcm_loop_cit */
1438
1439 static int tcm_loop_register_configfs(void)
1440 {
1441         struct target_fabric_configfs *fabric;
1442         int ret;
1443         /*
1444          * Set the TCM Loop HBA counter to zero
1445          */
1446         tcm_loop_hba_no_cnt = 0;
1447         /*
1448          * Register the top level struct config_item_type with TCM core
1449          */
1450         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1451         if (IS_ERR(fabric)) {
1452                 pr_err("tcm_loop_register_configfs() failed!\n");
1453                 return PTR_ERR(fabric);
1454         }
1455         /*
1456          * Setup the fabric API of function pointers used by target_core_mod
1457          */
1458         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1459         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1460         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1461         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1462         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1463         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1464         fabric->tf_ops.tpg_get_pr_transport_id_len =
1465                                         &tcm_loop_get_pr_transport_id_len;
1466         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1467                                         &tcm_loop_parse_pr_out_transport_id;
1468         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1469         fabric->tf_ops.tpg_check_demo_mode_cache =
1470                                         &tcm_loop_check_demo_mode_cache;
1471         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1472                                         &tcm_loop_check_demo_mode_write_protect;
1473         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1474                                         &tcm_loop_check_prod_mode_write_protect;
1475         /*
1476          * The TCM loopback fabric module runs in demo-mode to a local
1477          * virtual SCSI device, so fabric dependent initator ACLs are
1478          * not required.
1479          */
1480         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1481         fabric->tf_ops.tpg_release_fabric_acl =
1482                                         &tcm_loop_tpg_release_fabric_acl;
1483         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1484         /*
1485          * Used for setting up remaining TCM resources in process context
1486          */
1487         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1488         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1489         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1490         fabric->tf_ops.close_session = &tcm_loop_close_session;
1491         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1492         fabric->tf_ops.sess_get_initiator_sid = NULL;
1493         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1494         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1495         /*
1496          * Not used for TCM loopback
1497          */
1498         fabric->tf_ops.set_default_node_attributes =
1499                                         &tcm_loop_set_default_node_attributes;
1500         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1501         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1502         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1503         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1504         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1505         fabric->tf_ops.aborted_task = &tcm_loop_aborted_task;
1506
1507         /*
1508          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1509          */
1510         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1511         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1512         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1513         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1514         /*
1515          * fabric_post_link() and fabric_pre_unlink() are used for
1516          * registration and release of TCM Loop Virtual SCSI LUNs.
1517          */
1518         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1519         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1520         fabric->tf_ops.fabric_make_np = NULL;
1521         fabric->tf_ops.fabric_drop_np = NULL;
1522         /*
1523          * Setup default attribute lists for various fabric->tf_cit_tmpl
1524          */
1525         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1526         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1527         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1528         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1529         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1530         /*
1531          * Once fabric->tf_ops has been setup, now register the fabric for
1532          * use within TCM
1533          */
1534         ret = target_fabric_configfs_register(fabric);
1535         if (ret < 0) {
1536                 pr_err("target_fabric_configfs_register() for"
1537                                 " TCM_Loop failed!\n");
1538                 target_fabric_configfs_free(fabric);
1539                 return -1;
1540         }
1541         /*
1542          * Setup our local pointer to *fabric.
1543          */
1544         tcm_loop_fabric_configfs = fabric;
1545         pr_debug("TCM_LOOP[0] - Set fabric ->"
1546                         " tcm_loop_fabric_configfs\n");
1547         return 0;
1548 }
1549
1550 static void tcm_loop_deregister_configfs(void)
1551 {
1552         if (!tcm_loop_fabric_configfs)
1553                 return;
1554
1555         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1556         tcm_loop_fabric_configfs = NULL;
1557         pr_debug("TCM_LOOP[0] - Cleared"
1558                                 " tcm_loop_fabric_configfs\n");
1559 }
1560
1561 static int __init tcm_loop_fabric_init(void)
1562 {
1563         int ret = -ENOMEM;
1564
1565         tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1566         if (!tcm_loop_workqueue)
1567                 goto out;
1568
1569         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1570                                 sizeof(struct tcm_loop_cmd),
1571                                 __alignof__(struct tcm_loop_cmd),
1572                                 0, NULL);
1573         if (!tcm_loop_cmd_cache) {
1574                 pr_debug("kmem_cache_create() for"
1575                         " tcm_loop_cmd_cache failed\n");
1576                 goto out_destroy_workqueue;
1577         }
1578
1579         ret = tcm_loop_alloc_core_bus();
1580         if (ret)
1581                 goto out_destroy_cache;
1582
1583         ret = tcm_loop_register_configfs();
1584         if (ret)
1585                 goto out_release_core_bus;
1586
1587         return 0;
1588
1589 out_release_core_bus:
1590         tcm_loop_release_core_bus();
1591 out_destroy_cache:
1592         kmem_cache_destroy(tcm_loop_cmd_cache);
1593 out_destroy_workqueue:
1594         destroy_workqueue(tcm_loop_workqueue);
1595 out:
1596         return ret;
1597 }
1598
1599 static void __exit tcm_loop_fabric_exit(void)
1600 {
1601         tcm_loop_deregister_configfs();
1602         tcm_loop_release_core_bus();
1603         kmem_cache_destroy(tcm_loop_cmd_cache);
1604         destroy_workqueue(tcm_loop_workqueue);
1605 }
1606
1607 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1608 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1609 MODULE_LICENSE("GPL");
1610 module_init(tcm_loop_fabric_init);
1611 module_exit(tcm_loop_fabric_exit);