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