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