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