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