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