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