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