drivers/target/loopback/tcm_loop.c

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