drivers/target/loopback/tcm_loop.c

   1 /*******************************************************************************
   2  *
   3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
   4  * for emulated SAS initiator ports
   5  *
   6  * © Copyright 2011-2013 Datera, Inc.
   7  *
   8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   9  *
  10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  ****************************************************************************/
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/configfs.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_fabric.h>
  37 #include <target/target_core_fabric_configfs.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "tcm_loop.h"
  41
  42 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  43
  44 /* Local pointer to allocated TCM configfs fabric module */
  45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
  46
  47 static struct workqueue_struct *tcm_loop_workqueue;
  48 static struct kmem_cache *tcm_loop_cmd_cache;
  49
  50 static int tcm_loop_hba_no_cnt;
  51
  52 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
  53
  54 /*
  55  * Called from struct target_core_fabric_ops->check_stop_free()
  56  */
  57 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
  58 {
  59         /*
  60          * Do not release struct se_cmd's containing a valid TMR
  61          * pointer.  These will be released directly in tcm_loop_device_reset()
  62          * with transport_generic_free_cmd().
  63          */
  64         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
  65                 return 0;
  66         /*
  67          * Release the struct se_cmd, which will make a callback to release
  68          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
  69          */
  70         transport_generic_free_cmd(se_cmd, 0);
  71         return 1;
  72 }
  73
  74 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
  75 {
  76         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
  77                                 struct tcm_loop_cmd, tl_se_cmd);
  78
  79         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
  80 }
  81
  82 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
  83 {
  84         seq_printf(m, "tcm_loop_proc_info()\n");
  85         return 0;
  86 }
  87
  88 static int tcm_loop_driver_probe(struct device *);
  89 static int tcm_loop_driver_remove(struct device *);
  90
  91 static int pseudo_lld_bus_match(struct device *dev,
  92                                 struct device_driver *dev_driver)
  93 {
  94         return 1;
  95 }
  96
  97 static struct bus_type tcm_loop_lld_bus = {
  98         .name                   = "tcm_loop_bus",
  99         .match                  = pseudo_lld_bus_match,
 100         .probe                  = tcm_loop_driver_probe,
 101         .remove                 = tcm_loop_driver_remove,
 102 };
 103
 104 static struct device_driver tcm_loop_driverfs = {
 105         .name                   = "tcm_loop",
 106         .bus                    = &tcm_loop_lld_bus,
 107 };
 108 /*
 109  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 110  */
 111 struct device *tcm_loop_primary;
 112
 113 /*
 114  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 115  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 116  */
 117 static int tcm_loop_change_queue_depth(
 118         struct scsi_device *sdev,
 119         int depth,
 120         int reason)
 121 {
 122         switch (reason) {
 123         case SCSI_QDEPTH_DEFAULT:
 124                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 125                 break;
 126         case SCSI_QDEPTH_QFULL:
 127                 scsi_track_queue_full(sdev, depth);
 128                 break;
 129         case SCSI_QDEPTH_RAMP_UP:
 130                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 131                 break;
 132         default:
 133                 return -EOPNOTSUPP;
 134         }
 135         return sdev->queue_depth;
 136 }
 137
 138 static int tcm_loop_change_queue_type(struct scsi_device *sdev, int tag)
 139 {
 140         if (sdev->tagged_supported) {
 141                 scsi_set_tag_type(sdev, tag);
 142
 143                 if (tag)
 144                         scsi_activate_tcq(sdev, sdev->queue_depth);
 145                 else
 146                         scsi_deactivate_tcq(sdev, sdev->queue_depth);
 147         } else
 148                 tag = 0;
 149
 150         return tag;
 151 }
 152
 153 /*
 154  * Locate the SAM Task Attr from struct scsi_cmnd *
 155  */
 156 static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
 157 {
 158         if (sc->device->tagged_supported) {
 159                 switch (sc->tag) {
 160                 case HEAD_OF_QUEUE_TAG:
 161                         return MSG_HEAD_TAG;
 162                 case ORDERED_QUEUE_TAG:
 163                         return MSG_ORDERED_TAG;
 164                 default:
 165                         break;
 166                 }
 167         }
 168
 169         return MSG_SIMPLE_TAG;
 170 }
 171
 172 static void tcm_loop_submission_work(struct work_struct *work)
 173 {
 174         struct tcm_loop_cmd *tl_cmd =
 175                 container_of(work, struct tcm_loop_cmd, work);
 176         struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
 177         struct scsi_cmnd *sc = tl_cmd->sc;
 178         struct tcm_loop_nexus *tl_nexus;
 179         struct tcm_loop_hba *tl_hba;
 180         struct tcm_loop_tpg *tl_tpg;
 181         struct scatterlist *sgl_bidi = NULL;
 182         u32 sgl_bidi_count = 0;
 183         int rc;
 184
 185         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 186         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 187
 188         /*
 189          * Ensure that this tl_tpg reference from the incoming sc->device->id
 190          * has already been configured via tcm_loop_make_naa_tpg().
 191          */
 192         if (!tl_tpg->tl_hba) {
 193                 set_host_byte(sc, DID_NO_CONNECT);
 194                 goto out_done;
 195         }
 196         if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
 197                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 198                 goto out_done;
 199         }
 200         tl_nexus = tl_hba->tl_nexus;
 201         if (!tl_nexus) {
 202                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
 203                                 " does not exist\n");
 204                 set_host_byte(sc, DID_ERROR);
 205                 goto out_done;
 206         }
 207         if (scsi_bidi_cmnd(sc)) {
 208                 struct scsi_data_buffer *sdb = scsi_in(sc);
 209
 210                 sgl_bidi = sdb->table.sgl;
 211                 sgl_bidi_count = sdb->table.nents;
 212                 se_cmd->se_cmd_flags |= SCF_BIDI;
 213
 214         }
 215         rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
 216                         &tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
 217                         scsi_bufflen(sc), tcm_loop_sam_attr(sc),
 218                         sc->sc_data_direction, 0,
 219                         scsi_sglist(sc), scsi_sg_count(sc),
 220                         sgl_bidi, sgl_bidi_count);
 221         if (rc < 0) {
 222                 set_host_byte(sc, DID_NO_CONNECT);
 223                 goto out_done;
 224         }
 225         return;
 226
 227 out_done:
 228         sc->scsi_done(sc);
 229         return;
 230 }
 231
 232 /*
 233  * ->queuecommand can be and usually is called from interrupt context, so
 234  * defer the actual submission to a workqueue.
 235  */
 236 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 237 {
 238         struct tcm_loop_cmd *tl_cmd;
 239
 240         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 241                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 242                 sc->device->id, sc->device->channel, sc->device->lun,
 243                 sc->cmnd[0], scsi_bufflen(sc));
 244
 245         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
 246         if (!tl_cmd) {
 247                 pr_err("Unable to allocate struct tcm_loop_cmd\n");
 248                 set_host_byte(sc, DID_ERROR);
 249                 sc->scsi_done(sc);
 250                 return 0;
 251         }
 252
 253         tl_cmd->sc = sc;
 254         tl_cmd->sc_cmd_tag = sc->tag;
 255         INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
 256         queue_work(tcm_loop_workqueue, &tl_cmd->work);
 257         return 0;
 258 }
 259
 260 /*
 261  * Called from SCSI EH process context to issue a LUN_RESET TMR
 262  * to struct scsi_device
 263  */
 264 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 265                               struct tcm_loop_nexus *tl_nexus,
 266                               int lun, int task, enum tcm_tmreq_table tmr)
 267 {
 268         struct se_cmd *se_cmd = NULL;
 269         struct se_session *se_sess;
 270         struct se_portal_group *se_tpg;
 271         struct tcm_loop_cmd *tl_cmd = NULL;
 272         struct tcm_loop_tmr *tl_tmr = NULL;
 273         int ret = TMR_FUNCTION_FAILED, rc;
 274
 275         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 276         if (!tl_cmd) {
 277                 pr_err("Unable to allocate memory for tl_cmd\n");
 278                 return ret;
 279         }
 280
 281         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 282         if (!tl_tmr) {
 283                 pr_err("Unable to allocate memory for tl_tmr\n");
 284                 goto release;
 285         }
 286         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 287
 288         se_cmd = &tl_cmd->tl_se_cmd;
 289         se_tpg = &tl_tpg->tl_se_tpg;
 290         se_sess = tl_nexus->se_sess;
 291         /*
 292          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 293          */
 294         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 295                                 DMA_NONE, MSG_SIMPLE_TAG,
 296                                 &tl_cmd->tl_sense_buf[0]);
 297
 298         rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
 299         if (rc < 0)
 300                 goto release;
 301
 302         if (tmr == TMR_ABORT_TASK)
 303                 se_cmd->se_tmr_req->ref_task_tag = task;
 304
 305         /*
 306          * Locate the underlying TCM struct se_lun
 307          */
 308         if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
 309                 ret = TMR_LUN_DOES_NOT_EXIST;
 310                 goto release;
 311         }
 312         /*
 313          * Queue the TMR to TCM Core and sleep waiting for
 314          * tcm_loop_queue_tm_rsp() to wake us up.
 315          */
 316         transport_generic_handle_tmr(se_cmd);
 317         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 318         /*
 319          * The TMR LUN_RESET has completed, check the response status and
 320          * then release allocations.
 321          */
 322         ret = se_cmd->se_tmr_req->response;
 323 release:
 324         if (se_cmd)
 325                 transport_generic_free_cmd(se_cmd, 1);
 326         else
 327                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 328         kfree(tl_tmr);
 329         return ret;
 330 }
 331
 332 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 333 {
 334         struct tcm_loop_hba *tl_hba;
 335         struct tcm_loop_nexus *tl_nexus;
 336         struct tcm_loop_tpg *tl_tpg;
 337         int ret = FAILED;
 338
 339         /*
 340          * Locate the tcm_loop_hba_t pointer
 341          */
 342         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 343         /*
 344          * Locate the tl_nexus and se_sess pointers
 345          */
 346         tl_nexus = tl_hba->tl_nexus;
 347         if (!tl_nexus) {
 348                 pr_err("Unable to perform device reset without"
 349                                 " active I_T Nexus\n");
 350                 return FAILED;
 351         }
 352
 353         /*
 354          * Locate the tl_tpg pointer from TargetID in sc->device->id
 355          */
 356         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 357         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 358                                  sc->tag, TMR_ABORT_TASK);
 359         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 360 }
 361
 362 /*
 363  * Called from SCSI EH process context to issue a LUN_RESET TMR
 364  * to struct scsi_device
 365  */
 366 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 367 {
 368         struct tcm_loop_hba *tl_hba;
 369         struct tcm_loop_nexus *tl_nexus;
 370         struct tcm_loop_tpg *tl_tpg;
 371         int ret = FAILED;
 372
 373         /*
 374          * Locate the tcm_loop_hba_t pointer
 375          */
 376         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 377         /*
 378          * Locate the tl_nexus and se_sess pointers
 379          */
 380         tl_nexus = tl_hba->tl_nexus;
 381         if (!tl_nexus) {
 382                 pr_err("Unable to perform device reset without"
 383                                 " active I_T Nexus\n");
 384                 return FAILED;
 385         }
 386         /*
 387          * Locate the tl_tpg pointer from TargetID in sc->device->id
 388          */
 389         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 390         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 391                                  0, TMR_LUN_RESET);
 392         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 393 }
 394
 395 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 396 {
 397         struct tcm_loop_hba *tl_hba;
 398         struct tcm_loop_tpg *tl_tpg;
 399
 400         /*
 401          * Locate the tcm_loop_hba_t pointer
 402          */
 403         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 404         if (!tl_hba) {
 405                 pr_err("Unable to perform device reset without"
 406                                 " active I_T Nexus\n");
 407                 return FAILED;
 408         }
 409         /*
 410          * Locate the tl_tpg pointer from TargetID in sc->device->id
 411          */
 412         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 413         if (tl_tpg) {
 414                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 415                 return SUCCESS;
 416         }
 417         return FAILED;
 418 }
 419
 420 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 421 {
 422         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 423         return 0;
 424 }
 425
 426 static int tcm_loop_slave_configure(struct scsi_device *sd)
 427 {
 428         if (sd->tagged_supported) {
 429                 scsi_activate_tcq(sd, sd->queue_depth);
 430                 scsi_adjust_queue_depth(sd, MSG_SIMPLE_TAG,
 431                                         sd->host->cmd_per_lun);
 432         } else {
 433                 scsi_adjust_queue_depth(sd, 0,
 434                                         sd->host->cmd_per_lun);
 435         }
 436
 437         return 0;
 438 }
 439
 440 static struct scsi_host_template tcm_loop_driver_template = {
 441         .show_info              = tcm_loop_show_info,
 442         .proc_name              = "tcm_loopback",
 443         .name                   = "TCM_Loopback",
 444         .queuecommand           = tcm_loop_queuecommand,
 445         .change_queue_depth     = tcm_loop_change_queue_depth,
 446         .change_queue_type      = tcm_loop_change_queue_type,
 447         .eh_abort_handler = tcm_loop_abort_task,
 448         .eh_device_reset_handler = tcm_loop_device_reset,
 449         .eh_target_reset_handler = tcm_loop_target_reset,
 450         .can_queue              = 1024,
 451         .this_id                = -1,
 452         .sg_tablesize           = 256,
 453         .cmd_per_lun            = 1024,
 454         .max_sectors            = 0xFFFF,
 455         .use_clustering         = DISABLE_CLUSTERING,
 456         .slave_alloc            = tcm_loop_slave_alloc,
 457         .slave_configure        = tcm_loop_slave_configure,
 458         .module                 = THIS_MODULE,
 459 };
 460
 461 static int tcm_loop_driver_probe(struct device *dev)
 462 {
 463         struct tcm_loop_hba *tl_hba;
 464         struct Scsi_Host *sh;
 465         int error;
 466
 467         tl_hba = to_tcm_loop_hba(dev);
 468
 469         sh = scsi_host_alloc(&tcm_loop_driver_template,
 470                         sizeof(struct tcm_loop_hba));
 471         if (!sh) {
 472                 pr_err("Unable to allocate struct scsi_host\n");
 473                 return -ENODEV;
 474         }
 475         tl_hba->sh = sh;
 476
 477         /*
 478          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 479          */
 480         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 481         /*
 482          * Setup single ID, Channel and LUN for now..
 483          */
 484         sh->max_id = 2;
 485         sh->max_lun = 0;
 486         sh->max_channel = 0;
 487         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 488
 489         error = scsi_add_host(sh, &tl_hba->dev);
 490         if (error) {
 491                 pr_err("%s: scsi_add_host failed\n", __func__);
 492                 scsi_host_put(sh);
 493                 return -ENODEV;
 494         }
 495         return 0;
 496 }
 497
 498 static int tcm_loop_driver_remove(struct device *dev)
 499 {
 500         struct tcm_loop_hba *tl_hba;
 501         struct Scsi_Host *sh;
 502
 503         tl_hba = to_tcm_loop_hba(dev);
 504         sh = tl_hba->sh;
 505
 506         scsi_remove_host(sh);
 507         scsi_host_put(sh);
 508         return 0;
 509 }
 510
 511 static void tcm_loop_release_adapter(struct device *dev)
 512 {
 513         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 514
 515         kfree(tl_hba);
 516 }
 517
 518 /*
 519  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 520  */
 521 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 522 {
 523         int ret;
 524
 525         tl_hba->dev.bus = &tcm_loop_lld_bus;
 526         tl_hba->dev.parent = tcm_loop_primary;
 527         tl_hba->dev.release = &tcm_loop_release_adapter;
 528         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 529
 530         ret = device_register(&tl_hba->dev);
 531         if (ret) {
 532                 pr_err("device_register() failed for"
 533                                 " tl_hba->dev: %d\n", ret);
 534                 return -ENODEV;
 535         }
 536
 537         return 0;
 538 }
 539
 540 /*
 541  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 542  * tcm_loop SCSI bus.
 543  */
 544 static int tcm_loop_alloc_core_bus(void)
 545 {
 546         int ret;
 547
 548         tcm_loop_primary = root_device_register("tcm_loop_0");
 549         if (IS_ERR(tcm_loop_primary)) {
 550                 pr_err("Unable to allocate tcm_loop_primary\n");
 551                 return PTR_ERR(tcm_loop_primary);
 552         }
 553
 554         ret = bus_register(&tcm_loop_lld_bus);
 555         if (ret) {
 556                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 557                 goto dev_unreg;
 558         }
 559
 560         ret = driver_register(&tcm_loop_driverfs);
 561         if (ret) {
 562                 pr_err("driver_register() failed for"
 563                                 "tcm_loop_driverfs\n");
 564                 goto bus_unreg;
 565         }
 566
 567         pr_debug("Initialized TCM Loop Core Bus\n");
 568         return ret;
 569
 570 bus_unreg:
 571         bus_unregister(&tcm_loop_lld_bus);
 572 dev_unreg:
 573         root_device_unregister(tcm_loop_primary);
 574         return ret;
 575 }
 576
 577 static void tcm_loop_release_core_bus(void)
 578 {
 579         driver_unregister(&tcm_loop_driverfs);
 580         bus_unregister(&tcm_loop_lld_bus);
 581         root_device_unregister(tcm_loop_primary);
 582
 583         pr_debug("Releasing TCM Loop Core BUS\n");
 584 }
 585
 586 static char *tcm_loop_get_fabric_name(void)
 587 {
 588         return "loopback";
 589 }
 590
 591 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 592 {
 593         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 594         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 595         /*
 596          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 597          * time based on the protocol dependent prefix of the passed configfs group.
 598          *
 599          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 600          * ProtocolID using target_core_fabric_lib.c symbols.
 601          */
 602         switch (tl_hba->tl_proto_id) {
 603         case SCSI_PROTOCOL_SAS:
 604                 return sas_get_fabric_proto_ident(se_tpg);
 605         case SCSI_PROTOCOL_FCP:
 606                 return fc_get_fabric_proto_ident(se_tpg);
 607         case SCSI_PROTOCOL_ISCSI:
 608                 return iscsi_get_fabric_proto_ident(se_tpg);
 609         default:
 610                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 611                         " SAS emulation\n", tl_hba->tl_proto_id);
 612                 break;
 613         }
 614
 615         return sas_get_fabric_proto_ident(se_tpg);
 616 }
 617
 618 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 619 {
 620         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 621         /*
 622          * Return the passed NAA identifier for the SAS Target Port
 623          */
 624         return &tl_tpg->tl_hba->tl_wwn_address[0];
 625 }
 626
 627 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 628 {
 629         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 630         /*
 631          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 632          * to represent the SCSI Target Port.
 633          */
 634         return tl_tpg->tl_tpgt;
 635 }
 636
 637 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 638 {
 639         return 1;
 640 }
 641
 642 static u32 tcm_loop_get_pr_transport_id(
 643         struct se_portal_group *se_tpg,
 644         struct se_node_acl *se_nacl,
 645         struct t10_pr_registration *pr_reg,
 646         int *format_code,
 647         unsigned char *buf)
 648 {
 649         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 650         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 651
 652         switch (tl_hba->tl_proto_id) {
 653         case SCSI_PROTOCOL_SAS:
 654                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 655                                         format_code, buf);
 656         case SCSI_PROTOCOL_FCP:
 657                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 658                                         format_code, buf);
 659         case SCSI_PROTOCOL_ISCSI:
 660                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 661                                         format_code, buf);
 662         default:
 663                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 664                         " SAS emulation\n", tl_hba->tl_proto_id);
 665                 break;
 666         }
 667
 668         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 669                         format_code, buf);
 670 }
 671
 672 static u32 tcm_loop_get_pr_transport_id_len(
 673         struct se_portal_group *se_tpg,
 674         struct se_node_acl *se_nacl,
 675         struct t10_pr_registration *pr_reg,
 676         int *format_code)
 677 {
 678         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 679         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 680
 681         switch (tl_hba->tl_proto_id) {
 682         case SCSI_PROTOCOL_SAS:
 683                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 684                                         format_code);
 685         case SCSI_PROTOCOL_FCP:
 686                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 687                                         format_code);
 688         case SCSI_PROTOCOL_ISCSI:
 689                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 690                                         format_code);
 691         default:
 692                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 693                         " SAS emulation\n", tl_hba->tl_proto_id);
 694                 break;
 695         }
 696
 697         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 698                         format_code);
 699 }
 700
 701 /*
 702  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 703  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 704  */
 705 static char *tcm_loop_parse_pr_out_transport_id(
 706         struct se_portal_group *se_tpg,
 707         const char *buf,
 708         u32 *out_tid_len,
 709         char **port_nexus_ptr)
 710 {
 711         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 712         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 713
 714         switch (tl_hba->tl_proto_id) {
 715         case SCSI_PROTOCOL_SAS:
 716                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 717                                         port_nexus_ptr);
 718         case SCSI_PROTOCOL_FCP:
 719                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 720                                         port_nexus_ptr);
 721         case SCSI_PROTOCOL_ISCSI:
 722                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 723                                         port_nexus_ptr);
 724         default:
 725                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 726                         " SAS emulation\n", tl_hba->tl_proto_id);
 727                 break;
 728         }
 729
 730         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 731                         port_nexus_ptr);
 732 }
 733
 734 /*
 735  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 736  * based upon the incoming fabric dependent SCSI Initiator Port
 737  */
 738 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 739 {
 740         return 1;
 741 }
 742
 743 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 744 {
 745         return 0;
 746 }
 747
 748 /*
 749  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 750  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 751  */
 752 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 753 {
 754         return 0;
 755 }
 756
 757 /*
 758  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 759  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 760  * It has been added here as a nop for target_fabric_tf_ops_check()
 761  */
 762 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 763 {
 764         return 0;
 765 }
 766
 767 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 768         struct se_portal_group *se_tpg)
 769 {
 770         struct tcm_loop_nacl *tl_nacl;
 771
 772         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 773         if (!tl_nacl) {
 774                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 775                 return NULL;
 776         }
 777
 778         return &tl_nacl->se_node_acl;
 779 }
 780
 781 static void tcm_loop_tpg_release_fabric_acl(
 782         struct se_portal_group *se_tpg,
 783         struct se_node_acl *se_nacl)
 784 {
 785         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 786                                 struct tcm_loop_nacl, se_node_acl);
 787
 788         kfree(tl_nacl);
 789 }
 790
 791 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 792 {
 793         return 1;
 794 }
 795
 796 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 797 {
 798         return 1;
 799 }
 800
 801 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 802 {
 803         return;
 804 }
 805
 806 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 807 {
 808         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 809                         struct tcm_loop_cmd, tl_se_cmd);
 810
 811         return tl_cmd->sc_cmd_tag;
 812 }
 813
 814 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 815 {
 816         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 817                         struct tcm_loop_cmd, tl_se_cmd);
 818
 819         return tl_cmd->sc_cmd_state;
 820 }
 821
 822 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 823 {
 824         return 0;
 825 }
 826
 827 static void tcm_loop_close_session(struct se_session *se_sess)
 828 {
 829         return;
 830 };
 831
 832 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 833 {
 834         /*
 835          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 836          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 837          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 838          * format with transport_generic_map_mem_to_cmd().
 839          *
 840          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 841          * object execution queue.
 842          */
 843         target_execute_cmd(se_cmd);
 844         return 0;
 845 }
 846
 847 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 848 {
 849         return 0;
 850 }
 851
 852 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 853 {
 854         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 855                                 struct tcm_loop_cmd, tl_se_cmd);
 856         struct scsi_cmnd *sc = tl_cmd->sc;
 857
 858         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 859                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 860
 861         sc->result = SAM_STAT_GOOD;
 862         set_host_byte(sc, DID_OK);
 863         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 864             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 865                 scsi_set_resid(sc, se_cmd->residual_count);
 866         sc->scsi_done(sc);
 867         return 0;
 868 }
 869
 870 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 871 {
 872         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 873                                 struct tcm_loop_cmd, tl_se_cmd);
 874         struct scsi_cmnd *sc = tl_cmd->sc;
 875
 876         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 877                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 878
 879         if (se_cmd->sense_buffer &&
 880            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 881             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 882
 883                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 884                                 SCSI_SENSE_BUFFERSIZE);
 885                 sc->result = SAM_STAT_CHECK_CONDITION;
 886                 set_driver_byte(sc, DRIVER_SENSE);
 887         } else
 888                 sc->result = se_cmd->scsi_status;
 889
 890         set_host_byte(sc, DID_OK);
 891         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 892             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 893                 scsi_set_resid(sc, se_cmd->residual_count);
 894         sc->scsi_done(sc);
 895         return 0;
 896 }
 897
 898 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 899 {
 900         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 901         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 902         /*
 903          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 904          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 905          */
 906         atomic_set(&tl_tmr->tmr_complete, 1);
 907         wake_up(&tl_tmr->tl_tmr_wait);
 908 }
 909
 910 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 911 {
 912         switch (tl_hba->tl_proto_id) {
 913         case SCSI_PROTOCOL_SAS:
 914                 return "SAS";
 915         case SCSI_PROTOCOL_FCP:
 916                 return "FCP";
 917         case SCSI_PROTOCOL_ISCSI:
 918                 return "iSCSI";
 919         default:
 920                 break;
 921         }
 922
 923         return "Unknown";
 924 }
 925
 926 /* Start items for tcm_loop_port_cit */
 927
 928 static int tcm_loop_port_link(
 929         struct se_portal_group *se_tpg,
 930         struct se_lun *lun)
 931 {
 932         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 933                                 struct tcm_loop_tpg, tl_se_tpg);
 934         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 935
 936         atomic_inc(&tl_tpg->tl_tpg_port_count);
 937         smp_mb__after_atomic_inc();
 938         /*
 939          * Add Linux/SCSI struct scsi_device by HCTL
 940          */
 941         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 942
 943         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 944         return 0;
 945 }
 946
 947 static void tcm_loop_port_unlink(
 948         struct se_portal_group *se_tpg,
 949         struct se_lun *se_lun)
 950 {
 951         struct scsi_device *sd;
 952         struct tcm_loop_hba *tl_hba;
 953         struct tcm_loop_tpg *tl_tpg;
 954
 955         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 956         tl_hba = tl_tpg->tl_hba;
 957
 958         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 959                                 se_lun->unpacked_lun);
 960         if (!sd) {
 961                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 962                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 963                 return;
 964         }
 965         /*
 966          * Remove Linux/SCSI struct scsi_device by HCTL
 967          */
 968         scsi_remove_device(sd);
 969         scsi_device_put(sd);
 970
 971         atomic_dec(&tl_tpg->tl_tpg_port_count);
 972         smp_mb__after_atomic_dec();
 973
 974         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 975 }
 976
 977 /* End items for tcm_loop_port_cit */
 978
 979 /* Start items for tcm_loop_nexus_cit */
 980
 981 static int tcm_loop_make_nexus(
 982         struct tcm_loop_tpg *tl_tpg,
 983         const char *name)
 984 {
 985         struct se_portal_group *se_tpg;
 986         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 987         struct tcm_loop_nexus *tl_nexus;
 988         int ret = -ENOMEM;
 989
 990         if (tl_tpg->tl_hba->tl_nexus) {
 991                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
 992                 return -EEXIST;
 993         }
 994         se_tpg = &tl_tpg->tl_se_tpg;
 995
 996         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
 997         if (!tl_nexus) {
 998                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
 999                 return -ENOMEM;
1000         }
1001         /*
1002          * Initialize the struct se_session pointer
1003          */
1004         tl_nexus->se_sess = transport_init_session();
1005         if (IS_ERR(tl_nexus->se_sess)) {
1006                 ret = PTR_ERR(tl_nexus->se_sess);
1007                 goto out;
1008         }
1009         /*
1010          * Since we are running in 'demo mode' this call with generate a
1011          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1012          * Initiator port name of the passed configfs group 'name'.
1013          */
1014         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1015                                 se_tpg, (unsigned char *)name);
1016         if (!tl_nexus->se_sess->se_node_acl) {
1017                 transport_free_session(tl_nexus->se_sess);
1018                 goto out;
1019         }
1020         /*
1021          * Now, register the SAS I_T Nexus as active with the call to
1022          * transport_register_session()
1023          */
1024         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1025                         tl_nexus->se_sess, tl_nexus);
1026         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1027         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1028                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1029                 name);
1030         return 0;
1031
1032 out:
1033         kfree(tl_nexus);
1034         return ret;
1035 }
1036
1037 static int tcm_loop_drop_nexus(
1038         struct tcm_loop_tpg *tpg)
1039 {
1040         struct se_session *se_sess;
1041         struct tcm_loop_nexus *tl_nexus;
1042         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1043
1044         if (!tl_hba)
1045                 return -ENODEV;
1046
1047         tl_nexus = tl_hba->tl_nexus;
1048         if (!tl_nexus)
1049                 return -ENODEV;
1050
1051         se_sess = tl_nexus->se_sess;
1052         if (!se_sess)
1053                 return -ENODEV;
1054
1055         if (atomic_read(&tpg->tl_tpg_port_count)) {
1056                 pr_err("Unable to remove TCM_Loop I_T Nexus with"
1057                         " active TPG port count: %d\n",
1058                         atomic_read(&tpg->tl_tpg_port_count));
1059                 return -EPERM;
1060         }
1061
1062         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1063                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1064                 tl_nexus->se_sess->se_node_acl->initiatorname);
1065         /*
1066          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1067          */
1068         transport_deregister_session(tl_nexus->se_sess);
1069         tpg->tl_hba->tl_nexus = NULL;
1070         kfree(tl_nexus);
1071         return 0;
1072 }
1073
1074 /* End items for tcm_loop_nexus_cit */
1075
1076 static ssize_t tcm_loop_tpg_show_nexus(
1077         struct se_portal_group *se_tpg,
1078         char *page)
1079 {
1080         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1081                         struct tcm_loop_tpg, tl_se_tpg);
1082         struct tcm_loop_nexus *tl_nexus;
1083         ssize_t ret;
1084
1085         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1086         if (!tl_nexus)
1087                 return -ENODEV;
1088
1089         ret = snprintf(page, PAGE_SIZE, "%s\n",
1090                 tl_nexus->se_sess->se_node_acl->initiatorname);
1091
1092         return ret;
1093 }
1094
1095 static ssize_t tcm_loop_tpg_store_nexus(
1096         struct se_portal_group *se_tpg,
1097         const char *page,
1098         size_t count)
1099 {
1100         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1101                         struct tcm_loop_tpg, tl_se_tpg);
1102         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1103         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1104         int ret;
1105         /*
1106          * Shutdown the active I_T nexus if 'NULL' is passed..
1107          */
1108         if (!strncmp(page, "NULL", 4)) {
1109                 ret = tcm_loop_drop_nexus(tl_tpg);
1110                 return (!ret) ? count : ret;
1111         }
1112         /*
1113          * Otherwise make sure the passed virtual Initiator port WWN matches
1114          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1115          * tcm_loop_make_nexus()
1116          */
1117         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1118                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1119                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1120                 return -EINVAL;
1121         }
1122         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1123
1124         ptr = strstr(i_port, "naa.");
1125         if (ptr) {
1126                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1127                         pr_err("Passed SAS Initiator Port %s does not"
1128                                 " match target port protoid: %s\n", i_port,
1129                                 tcm_loop_dump_proto_id(tl_hba));
1130                         return -EINVAL;
1131                 }
1132                 port_ptr = &i_port[0];
1133                 goto check_newline;
1134         }
1135         ptr = strstr(i_port, "fc.");
1136         if (ptr) {
1137                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1138                         pr_err("Passed FCP Initiator Port %s does not"
1139                                 " match target port protoid: %s\n", i_port,
1140                                 tcm_loop_dump_proto_id(tl_hba));
1141                         return -EINVAL;
1142                 }
1143                 port_ptr = &i_port[3]; /* Skip over "fc." */
1144                 goto check_newline;
1145         }
1146         ptr = strstr(i_port, "iqn.");
1147         if (ptr) {
1148                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1149                         pr_err("Passed iSCSI Initiator Port %s does not"
1150                                 " match target port protoid: %s\n", i_port,
1151                                 tcm_loop_dump_proto_id(tl_hba));
1152                         return -EINVAL;
1153                 }
1154                 port_ptr = &i_port[0];
1155                 goto check_newline;
1156         }
1157         pr_err("Unable to locate prefix for emulated Initiator Port:"
1158                         " %s\n", i_port);
1159         return -EINVAL;
1160         /*
1161          * Clear any trailing newline for the NAA WWN
1162          */
1163 check_newline:
1164         if (i_port[strlen(i_port)-1] == '\n')
1165                 i_port[strlen(i_port)-1] = '\0';
1166
1167         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1168         if (ret < 0)
1169                 return ret;
1170
1171         return count;
1172 }
1173
1174 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1175
1176 static ssize_t tcm_loop_tpg_show_transport_status(
1177         struct se_portal_group *se_tpg,
1178         char *page)
1179 {
1180         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1181                         struct tcm_loop_tpg, tl_se_tpg);
1182         const char *status = NULL;
1183         ssize_t ret = -EINVAL;
1184
1185         switch (tl_tpg->tl_transport_status) {
1186         case TCM_TRANSPORT_ONLINE:
1187                 status = "online";
1188                 break;
1189         case TCM_TRANSPORT_OFFLINE:
1190                 status = "offline";
1191                 break;
1192         default:
1193                 break;
1194         }
1195
1196         if (status)
1197                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1198
1199         return ret;
1200 }
1201
1202 static ssize_t tcm_loop_tpg_store_transport_status(
1203         struct se_portal_group *se_tpg,
1204         const char *page,
1205         size_t count)
1206 {
1207         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1208                         struct tcm_loop_tpg, tl_se_tpg);
1209
1210         if (!strncmp(page, "online", 6)) {
1211                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1212                 return count;
1213         }
1214         if (!strncmp(page, "offline", 7)) {
1215                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1216                 return count;
1217         }
1218         return -EINVAL;
1219 }
1220
1221 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1222
1223 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1224         &tcm_loop_tpg_nexus.attr,
1225         &tcm_loop_tpg_transport_status.attr,
1226         NULL,
1227 };
1228
1229 /* Start items for tcm_loop_naa_cit */
1230
1231 struct se_portal_group *tcm_loop_make_naa_tpg(
1232         struct se_wwn *wwn,
1233         struct config_group *group,
1234         const char *name)
1235 {
1236         struct tcm_loop_hba *tl_hba = container_of(wwn,
1237                         struct tcm_loop_hba, tl_hba_wwn);
1238         struct tcm_loop_tpg *tl_tpg;
1239         char *tpgt_str, *end_ptr;
1240         int ret;
1241         unsigned short int tpgt;
1242
1243         tpgt_str = strstr(name, "tpgt_");
1244         if (!tpgt_str) {
1245                 pr_err("Unable to locate \"tpgt_#\" directory"
1246                                 " group\n");
1247                 return ERR_PTR(-EINVAL);
1248         }
1249         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1250         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1251
1252         if (tpgt >= TL_TPGS_PER_HBA) {
1253                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1254                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1255                 return ERR_PTR(-EINVAL);
1256         }
1257         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1258         tl_tpg->tl_hba = tl_hba;
1259         tl_tpg->tl_tpgt = tpgt;
1260         /*
1261          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1262          */
1263         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1264                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1265                         TRANSPORT_TPG_TYPE_NORMAL);
1266         if (ret < 0)
1267                 return ERR_PTR(-ENOMEM);
1268
1269         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1270                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1271                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1272
1273         return &tl_tpg->tl_se_tpg;
1274 }
1275
1276 void tcm_loop_drop_naa_tpg(
1277         struct se_portal_group *se_tpg)
1278 {
1279         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1280         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1281                                 struct tcm_loop_tpg, tl_se_tpg);
1282         struct tcm_loop_hba *tl_hba;
1283         unsigned short tpgt;
1284
1285         tl_hba = tl_tpg->tl_hba;
1286         tpgt = tl_tpg->tl_tpgt;
1287         /*
1288          * Release the I_T Nexus for the Virtual SAS link if present
1289          */
1290         tcm_loop_drop_nexus(tl_tpg);
1291         /*
1292          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1293          */
1294         core_tpg_deregister(se_tpg);
1295
1296         tl_tpg->tl_hba = NULL;
1297         tl_tpg->tl_tpgt = 0;
1298
1299         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1300                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1301                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1302 }
1303
1304 /* End items for tcm_loop_naa_cit */
1305
1306 /* Start items for tcm_loop_cit */
1307
1308 struct se_wwn *tcm_loop_make_scsi_hba(
1309         struct target_fabric_configfs *tf,
1310         struct config_group *group,
1311         const char *name)
1312 {
1313         struct tcm_loop_hba *tl_hba;
1314         struct Scsi_Host *sh;
1315         char *ptr;
1316         int ret, off = 0;
1317
1318         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1319         if (!tl_hba) {
1320                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1321                 return ERR_PTR(-ENOMEM);
1322         }
1323         /*
1324          * Determine the emulated Protocol Identifier and Target Port Name
1325          * based on the incoming configfs directory name.
1326          */
1327         ptr = strstr(name, "naa.");
1328         if (ptr) {
1329                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1330                 goto check_len;
1331         }
1332         ptr = strstr(name, "fc.");
1333         if (ptr) {
1334                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1335                 off = 3; /* Skip over "fc." */
1336                 goto check_len;
1337         }
1338         ptr = strstr(name, "iqn.");
1339         if (!ptr) {
1340                 pr_err("Unable to locate prefix for emulated Target "
1341                                 "Port: %s\n", name);
1342                 ret = -EINVAL;
1343                 goto out;
1344         }
1345         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1346
1347 check_len:
1348         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1349                 pr_err("Emulated NAA %s Address: %s, exceeds"
1350                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1351                         TL_WWN_ADDR_LEN);
1352                 ret = -EINVAL;
1353                 goto out;
1354         }
1355         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1356
1357         /*
1358          * Call device_register(tl_hba->dev) to register the emulated
1359          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1360          * device_register() callbacks in tcm_loop_driver_probe()
1361          */
1362         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1363         if (ret)
1364                 goto out;
1365
1366         sh = tl_hba->sh;
1367         tcm_loop_hba_no_cnt++;
1368         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1369                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1370                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1371
1372         return &tl_hba->tl_hba_wwn;
1373 out:
1374         kfree(tl_hba);
1375         return ERR_PTR(ret);
1376 }
1377
1378 void tcm_loop_drop_scsi_hba(
1379         struct se_wwn *wwn)
1380 {
1381         struct tcm_loop_hba *tl_hba = container_of(wwn,
1382                                 struct tcm_loop_hba, tl_hba_wwn);
1383
1384         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1385                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1386                 tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1387         /*
1388          * Call device_unregister() on the original tl_hba->dev.
1389          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1390          * release *tl_hba;
1391          */
1392         device_unregister(&tl_hba->dev);
1393 }
1394
1395 /* Start items for tcm_loop_cit */
1396 static ssize_t tcm_loop_wwn_show_attr_version(
1397         struct target_fabric_configfs *tf,
1398         char *page)
1399 {
1400         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1401 }
1402
1403 TF_WWN_ATTR_RO(tcm_loop, version);
1404
1405 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1406         &tcm_loop_wwn_version.attr,
1407         NULL,
1408 };
1409
1410 /* End items for tcm_loop_cit */
1411
1412 static int tcm_loop_register_configfs(void)
1413 {
1414         struct target_fabric_configfs *fabric;
1415         int ret;
1416         /*
1417          * Set the TCM Loop HBA counter to zero
1418          */
1419         tcm_loop_hba_no_cnt = 0;
1420         /*
1421          * Register the top level struct config_item_type with TCM core
1422          */
1423         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1424         if (IS_ERR(fabric)) {
1425                 pr_err("tcm_loop_register_configfs() failed!\n");
1426                 return PTR_ERR(fabric);
1427         }
1428         /*
1429          * Setup the fabric API of function pointers used by target_core_mod
1430          */
1431         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1432         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1433         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1434         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1435         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1436         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1437         fabric->tf_ops.tpg_get_pr_transport_id_len =
1438                                         &tcm_loop_get_pr_transport_id_len;
1439         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1440                                         &tcm_loop_parse_pr_out_transport_id;
1441         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1442         fabric->tf_ops.tpg_check_demo_mode_cache =
1443                                         &tcm_loop_check_demo_mode_cache;
1444         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1445                                         &tcm_loop_check_demo_mode_write_protect;
1446         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1447                                         &tcm_loop_check_prod_mode_write_protect;
1448         /*
1449          * The TCM loopback fabric module runs in demo-mode to a local
1450          * virtual SCSI device, so fabric dependent initator ACLs are
1451          * not required.
1452          */
1453         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1454         fabric->tf_ops.tpg_release_fabric_acl =
1455                                         &tcm_loop_tpg_release_fabric_acl;
1456         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1457         /*
1458          * Used for setting up remaining TCM resources in process context
1459          */
1460         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1461         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1462         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1463         fabric->tf_ops.close_session = &tcm_loop_close_session;
1464         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1465         fabric->tf_ops.sess_get_initiator_sid = NULL;
1466         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1467         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1468         /*
1469          * Not used for TCM loopback
1470          */
1471         fabric->tf_ops.set_default_node_attributes =
1472                                         &tcm_loop_set_default_node_attributes;
1473         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1474         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1475         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1476         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1477         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1478
1479         /*
1480          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1481          */
1482         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1483         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1484         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1485         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1486         /*
1487          * fabric_post_link() and fabric_pre_unlink() are used for
1488          * registration and release of TCM Loop Virtual SCSI LUNs.
1489          */
1490         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1491         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1492         fabric->tf_ops.fabric_make_np = NULL;
1493         fabric->tf_ops.fabric_drop_np = NULL;
1494         /*
1495          * Setup default attribute lists for various fabric->tf_cit_tmpl
1496          */
1497         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1498         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1499         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1500         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1501         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1502         /*
1503          * Once fabric->tf_ops has been setup, now register the fabric for
1504          * use within TCM
1505          */
1506         ret = target_fabric_configfs_register(fabric);
1507         if (ret < 0) {
1508                 pr_err("target_fabric_configfs_register() for"
1509                                 " TCM_Loop failed!\n");
1510                 target_fabric_configfs_free(fabric);
1511                 return -1;
1512         }
1513         /*
1514          * Setup our local pointer to *fabric.
1515          */
1516         tcm_loop_fabric_configfs = fabric;
1517         pr_debug("TCM_LOOP[0] - Set fabric ->"
1518                         " tcm_loop_fabric_configfs\n");
1519         return 0;
1520 }
1521
1522 static void tcm_loop_deregister_configfs(void)
1523 {
1524         if (!tcm_loop_fabric_configfs)
1525                 return;
1526
1527         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1528         tcm_loop_fabric_configfs = NULL;
1529         pr_debug("TCM_LOOP[0] - Cleared"
1530                                 " tcm_loop_fabric_configfs\n");
1531 }
1532
1533 static int __init tcm_loop_fabric_init(void)
1534 {
1535         int ret = -ENOMEM;
1536
1537         tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1538         if (!tcm_loop_workqueue)
1539                 goto out;
1540
1541         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1542                                 sizeof(struct tcm_loop_cmd),
1543                                 __alignof__(struct tcm_loop_cmd),
1544                                 0, NULL);
1545         if (!tcm_loop_cmd_cache) {
1546                 pr_debug("kmem_cache_create() for"
1547                         " tcm_loop_cmd_cache failed\n");
1548                 goto out_destroy_workqueue;
1549         }
1550
1551         ret = tcm_loop_alloc_core_bus();
1552         if (ret)
1553                 goto out_destroy_cache;
1554
1555         ret = tcm_loop_register_configfs();
1556         if (ret)
1557                 goto out_release_core_bus;
1558
1559         return 0;
1560
1561 out_release_core_bus:
1562         tcm_loop_release_core_bus();
1563 out_destroy_cache:
1564         kmem_cache_destroy(tcm_loop_cmd_cache);
1565 out_destroy_workqueue:
1566         destroy_workqueue(tcm_loop_workqueue);
1567 out:
1568         return ret;
1569 }
1570
1571 static void __exit tcm_loop_fabric_exit(void)
1572 {
1573         tcm_loop_deregister_configfs();
1574         tcm_loop_release_core_bus();
1575         kmem_cache_destroy(tcm_loop_cmd_cache);
1576         destroy_workqueue(tcm_loop_workqueue);
1577 }
1578
1579 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1580 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1581 MODULE_LICENSE("GPL");
1582 module_init(tcm_loop_fabric_init);
1583 module_exit(tcm_loop_fabric_exit);