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