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                         scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
 222         if (rc < 0) {
 223                 set_host_byte(sc, DID_NO_CONNECT);
 224                 goto out_done;
 225         }
 226         return;
 227
 228 out_done:
 229         sc->scsi_done(sc);
 230         return;
 231 }
 232
 233 /*
 234  * ->queuecommand can be and usually is called from interrupt context, so
 235  * defer the actual submission to a workqueue.
 236  */
 237 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 238 {
 239         struct tcm_loop_cmd *tl_cmd;
 240
 241         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 242                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 243                 sc->device->id, sc->device->channel, sc->device->lun,
 244                 sc->cmnd[0], scsi_bufflen(sc));
 245
 246         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
 247         if (!tl_cmd) {
 248                 pr_err("Unable to allocate struct tcm_loop_cmd\n");
 249                 set_host_byte(sc, DID_ERROR);
 250                 sc->scsi_done(sc);
 251                 return 0;
 252         }
 253
 254         tl_cmd->sc = sc;
 255         tl_cmd->sc_cmd_tag = sc->tag;
 256         INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
 257         queue_work(tcm_loop_workqueue, &tl_cmd->work);
 258         return 0;
 259 }
 260
 261 /*
 262  * Called from SCSI EH process context to issue a LUN_RESET TMR
 263  * to struct scsi_device
 264  */
 265 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 266                               struct tcm_loop_nexus *tl_nexus,
 267                               int lun, int task, enum tcm_tmreq_table tmr)
 268 {
 269         struct se_cmd *se_cmd = NULL;
 270         struct se_session *se_sess;
 271         struct se_portal_group *se_tpg;
 272         struct tcm_loop_cmd *tl_cmd = NULL;
 273         struct tcm_loop_tmr *tl_tmr = NULL;
 274         int ret = TMR_FUNCTION_FAILED, rc;
 275
 276         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 277         if (!tl_cmd) {
 278                 pr_err("Unable to allocate memory for tl_cmd\n");
 279                 return ret;
 280         }
 281
 282         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 283         if (!tl_tmr) {
 284                 pr_err("Unable to allocate memory for tl_tmr\n");
 285                 goto release;
 286         }
 287         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 288
 289         se_cmd = &tl_cmd->tl_se_cmd;
 290         se_tpg = &tl_tpg->tl_se_tpg;
 291         se_sess = tl_nexus->se_sess;
 292         /*
 293          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 294          */
 295         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 296                                 DMA_NONE, MSG_SIMPLE_TAG,
 297                                 &tl_cmd->tl_sense_buf[0]);
 298
 299         rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
 300         if (rc < 0)
 301                 goto release;
 302
 303         if (tmr == TMR_ABORT_TASK)
 304                 se_cmd->se_tmr_req->ref_task_tag = task;
 305
 306         /*
 307          * Locate the underlying TCM struct se_lun
 308          */
 309         if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
 310                 ret = TMR_LUN_DOES_NOT_EXIST;
 311                 goto release;
 312         }
 313         /*
 314          * Queue the TMR to TCM Core and sleep waiting for
 315          * tcm_loop_queue_tm_rsp() to wake us up.
 316          */
 317         transport_generic_handle_tmr(se_cmd);
 318         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 319         /*
 320          * The TMR LUN_RESET has completed, check the response status and
 321          * then release allocations.
 322          */
 323         ret = se_cmd->se_tmr_req->response;
 324 release:
 325         if (se_cmd)
 326                 transport_generic_free_cmd(se_cmd, 1);
 327         else
 328                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 329         kfree(tl_tmr);
 330         return ret;
 331 }
 332
 333 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 334 {
 335         struct tcm_loop_hba *tl_hba;
 336         struct tcm_loop_nexus *tl_nexus;
 337         struct tcm_loop_tpg *tl_tpg;
 338         int ret = FAILED;
 339
 340         /*
 341          * Locate the tcm_loop_hba_t pointer
 342          */
 343         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 344         /*
 345          * Locate the tl_nexus and se_sess pointers
 346          */
 347         tl_nexus = tl_hba->tl_nexus;
 348         if (!tl_nexus) {
 349                 pr_err("Unable to perform device reset without"
 350                                 " active I_T Nexus\n");
 351                 return FAILED;
 352         }
 353
 354         /*
 355          * Locate the tl_tpg pointer from TargetID in sc->device->id
 356          */
 357         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 358         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 359                                  sc->tag, TMR_ABORT_TASK);
 360         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 361 }
 362
 363 /*
 364  * Called from SCSI EH process context to issue a LUN_RESET TMR
 365  * to struct scsi_device
 366  */
 367 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 368 {
 369         struct tcm_loop_hba *tl_hba;
 370         struct tcm_loop_nexus *tl_nexus;
 371         struct tcm_loop_tpg *tl_tpg;
 372         int ret = FAILED;
 373
 374         /*
 375          * Locate the tcm_loop_hba_t pointer
 376          */
 377         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 378         /*
 379          * Locate the tl_nexus and se_sess pointers
 380          */
 381         tl_nexus = tl_hba->tl_nexus;
 382         if (!tl_nexus) {
 383                 pr_err("Unable to perform device reset without"
 384                                 " active I_T Nexus\n");
 385                 return FAILED;
 386         }
 387         /*
 388          * Locate the tl_tpg pointer from TargetID in sc->device->id
 389          */
 390         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 391         ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
 392                                  0, TMR_LUN_RESET);
 393         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 394 }
 395
 396 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 397 {
 398         struct tcm_loop_hba *tl_hba;
 399         struct tcm_loop_tpg *tl_tpg;
 400
 401         /*
 402          * Locate the tcm_loop_hba_t pointer
 403          */
 404         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 405         if (!tl_hba) {
 406                 pr_err("Unable to perform device reset without"
 407                                 " active I_T Nexus\n");
 408                 return FAILED;
 409         }
 410         /*
 411          * Locate the tl_tpg pointer from TargetID in sc->device->id
 412          */
 413         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 414         if (tl_tpg) {
 415                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 416                 return SUCCESS;
 417         }
 418         return FAILED;
 419 }
 420
 421 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 422 {
 423         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 424         return 0;
 425 }
 426
 427 static int tcm_loop_slave_configure(struct scsi_device *sd)
 428 {
 429         if (sd->tagged_supported) {
 430                 scsi_activate_tcq(sd, sd->queue_depth);
 431                 scsi_adjust_queue_depth(sd, MSG_SIMPLE_TAG,
 432                                         sd->host->cmd_per_lun);
 433         } else {
 434                 scsi_adjust_queue_depth(sd, 0,
 435                                         sd->host->cmd_per_lun);
 436         }
 437
 438         return 0;
 439 }
 440
 441 static struct scsi_host_template tcm_loop_driver_template = {
 442         .show_info              = tcm_loop_show_info,
 443         .proc_name              = "tcm_loopback",
 444         .name                   = "TCM_Loopback",
 445         .queuecommand           = tcm_loop_queuecommand,
 446         .change_queue_depth     = tcm_loop_change_queue_depth,
 447         .change_queue_type      = tcm_loop_change_queue_type,
 448         .eh_abort_handler = tcm_loop_abort_task,
 449         .eh_device_reset_handler = tcm_loop_device_reset,
 450         .eh_target_reset_handler = tcm_loop_target_reset,
 451         .can_queue              = 1024,
 452         .this_id                = -1,
 453         .sg_tablesize           = 256,
 454         .cmd_per_lun            = 1024,
 455         .max_sectors            = 0xFFFF,
 456         .use_clustering         = DISABLE_CLUSTERING,
 457         .slave_alloc            = tcm_loop_slave_alloc,
 458         .slave_configure        = tcm_loop_slave_configure,
 459         .module                 = THIS_MODULE,
 460 };
 461
 462 static int tcm_loop_driver_probe(struct device *dev)
 463 {
 464         struct tcm_loop_hba *tl_hba;
 465         struct Scsi_Host *sh;
 466         int error, host_prot;
 467
 468         tl_hba = to_tcm_loop_hba(dev);
 469
 470         sh = scsi_host_alloc(&tcm_loop_driver_template,
 471                         sizeof(struct tcm_loop_hba));
 472         if (!sh) {
 473                 pr_err("Unable to allocate struct scsi_host\n");
 474                 return -ENODEV;
 475         }
 476         tl_hba->sh = sh;
 477
 478         /*
 479          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 480          */
 481         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 482         /*
 483          * Setup single ID, Channel and LUN for now..
 484          */
 485         sh->max_id = 2;
 486         sh->max_lun = 0;
 487         sh->max_channel = 0;
 488         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 489
 490         host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
 491                     SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
 492                     SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
 493
 494         scsi_host_set_prot(sh, host_prot);
 495         scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
 496
 497         error = scsi_add_host(sh, &tl_hba->dev);
 498         if (error) {
 499                 pr_err("%s: scsi_add_host failed\n", __func__);
 500                 scsi_host_put(sh);
 501                 return -ENODEV;
 502         }
 503         return 0;
 504 }
 505
 506 static int tcm_loop_driver_remove(struct device *dev)
 507 {
 508         struct tcm_loop_hba *tl_hba;
 509         struct Scsi_Host *sh;
 510
 511         tl_hba = to_tcm_loop_hba(dev);
 512         sh = tl_hba->sh;
 513
 514         scsi_remove_host(sh);
 515         scsi_host_put(sh);
 516         return 0;
 517 }
 518
 519 static void tcm_loop_release_adapter(struct device *dev)
 520 {
 521         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 522
 523         kfree(tl_hba);
 524 }
 525
 526 /*
 527  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 528  */
 529 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 530 {
 531         int ret;
 532
 533         tl_hba->dev.bus = &tcm_loop_lld_bus;
 534         tl_hba->dev.parent = tcm_loop_primary;
 535         tl_hba->dev.release = &tcm_loop_release_adapter;
 536         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 537
 538         ret = device_register(&tl_hba->dev);
 539         if (ret) {
 540                 pr_err("device_register() failed for"
 541                                 " tl_hba->dev: %d\n", ret);
 542                 return -ENODEV;
 543         }
 544
 545         return 0;
 546 }
 547
 548 /*
 549  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 550  * tcm_loop SCSI bus.
 551  */
 552 static int tcm_loop_alloc_core_bus(void)
 553 {
 554         int ret;
 555
 556         tcm_loop_primary = root_device_register("tcm_loop_0");
 557         if (IS_ERR(tcm_loop_primary)) {
 558                 pr_err("Unable to allocate tcm_loop_primary\n");
 559                 return PTR_ERR(tcm_loop_primary);
 560         }
 561
 562         ret = bus_register(&tcm_loop_lld_bus);
 563         if (ret) {
 564                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 565                 goto dev_unreg;
 566         }
 567
 568         ret = driver_register(&tcm_loop_driverfs);
 569         if (ret) {
 570                 pr_err("driver_register() failed for"
 571                                 "tcm_loop_driverfs\n");
 572                 goto bus_unreg;
 573         }
 574
 575         pr_debug("Initialized TCM Loop Core Bus\n");
 576         return ret;
 577
 578 bus_unreg:
 579         bus_unregister(&tcm_loop_lld_bus);
 580 dev_unreg:
 581         root_device_unregister(tcm_loop_primary);
 582         return ret;
 583 }
 584
 585 static void tcm_loop_release_core_bus(void)
 586 {
 587         driver_unregister(&tcm_loop_driverfs);
 588         bus_unregister(&tcm_loop_lld_bus);
 589         root_device_unregister(tcm_loop_primary);
 590
 591         pr_debug("Releasing TCM Loop Core BUS\n");
 592 }
 593
 594 static char *tcm_loop_get_fabric_name(void)
 595 {
 596         return "loopback";
 597 }
 598
 599 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 600 {
 601         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 602         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 603         /*
 604          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 605          * time based on the protocol dependent prefix of the passed configfs group.
 606          *
 607          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 608          * ProtocolID using target_core_fabric_lib.c symbols.
 609          */
 610         switch (tl_hba->tl_proto_id) {
 611         case SCSI_PROTOCOL_SAS:
 612                 return sas_get_fabric_proto_ident(se_tpg);
 613         case SCSI_PROTOCOL_FCP:
 614                 return fc_get_fabric_proto_ident(se_tpg);
 615         case SCSI_PROTOCOL_ISCSI:
 616                 return iscsi_get_fabric_proto_ident(se_tpg);
 617         default:
 618                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 619                         " SAS emulation\n", tl_hba->tl_proto_id);
 620                 break;
 621         }
 622
 623         return sas_get_fabric_proto_ident(se_tpg);
 624 }
 625
 626 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 627 {
 628         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 629         /*
 630          * Return the passed NAA identifier for the SAS Target Port
 631          */
 632         return &tl_tpg->tl_hba->tl_wwn_address[0];
 633 }
 634
 635 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 636 {
 637         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 638         /*
 639          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 640          * to represent the SCSI Target Port.
 641          */
 642         return tl_tpg->tl_tpgt;
 643 }
 644
 645 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 646 {
 647         return 1;
 648 }
 649
 650 static u32 tcm_loop_get_pr_transport_id(
 651         struct se_portal_group *se_tpg,
 652         struct se_node_acl *se_nacl,
 653         struct t10_pr_registration *pr_reg,
 654         int *format_code,
 655         unsigned char *buf)
 656 {
 657         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 658         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 659
 660         switch (tl_hba->tl_proto_id) {
 661         case SCSI_PROTOCOL_SAS:
 662                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 663                                         format_code, buf);
 664         case SCSI_PROTOCOL_FCP:
 665                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 666                                         format_code, buf);
 667         case SCSI_PROTOCOL_ISCSI:
 668                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 669                                         format_code, buf);
 670         default:
 671                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 672                         " SAS emulation\n", tl_hba->tl_proto_id);
 673                 break;
 674         }
 675
 676         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 677                         format_code, buf);
 678 }
 679
 680 static u32 tcm_loop_get_pr_transport_id_len(
 681         struct se_portal_group *se_tpg,
 682         struct se_node_acl *se_nacl,
 683         struct t10_pr_registration *pr_reg,
 684         int *format_code)
 685 {
 686         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 687         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 688
 689         switch (tl_hba->tl_proto_id) {
 690         case SCSI_PROTOCOL_SAS:
 691                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 692                                         format_code);
 693         case SCSI_PROTOCOL_FCP:
 694                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 695                                         format_code);
 696         case SCSI_PROTOCOL_ISCSI:
 697                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 698                                         format_code);
 699         default:
 700                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 701                         " SAS emulation\n", tl_hba->tl_proto_id);
 702                 break;
 703         }
 704
 705         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 706                         format_code);
 707 }
 708
 709 /*
 710  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 711  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 712  */
 713 static char *tcm_loop_parse_pr_out_transport_id(
 714         struct se_portal_group *se_tpg,
 715         const char *buf,
 716         u32 *out_tid_len,
 717         char **port_nexus_ptr)
 718 {
 719         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 720         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 721
 722         switch (tl_hba->tl_proto_id) {
 723         case SCSI_PROTOCOL_SAS:
 724                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 725                                         port_nexus_ptr);
 726         case SCSI_PROTOCOL_FCP:
 727                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 728                                         port_nexus_ptr);
 729         case SCSI_PROTOCOL_ISCSI:
 730                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 731                                         port_nexus_ptr);
 732         default:
 733                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 734                         " SAS emulation\n", tl_hba->tl_proto_id);
 735                 break;
 736         }
 737
 738         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 739                         port_nexus_ptr);
 740 }
 741
 742 /*
 743  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 744  * based upon the incoming fabric dependent SCSI Initiator Port
 745  */
 746 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 747 {
 748         return 1;
 749 }
 750
 751 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 752 {
 753         return 0;
 754 }
 755
 756 /*
 757  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 758  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 759  */
 760 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 761 {
 762         return 0;
 763 }
 764
 765 /*
 766  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 767  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 768  * It has been added here as a nop for target_fabric_tf_ops_check()
 769  */
 770 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 771 {
 772         return 0;
 773 }
 774
 775 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 776         struct se_portal_group *se_tpg)
 777 {
 778         struct tcm_loop_nacl *tl_nacl;
 779
 780         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 781         if (!tl_nacl) {
 782                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 783                 return NULL;
 784         }
 785
 786         return &tl_nacl->se_node_acl;
 787 }
 788
 789 static void tcm_loop_tpg_release_fabric_acl(
 790         struct se_portal_group *se_tpg,
 791         struct se_node_acl *se_nacl)
 792 {
 793         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 794                                 struct tcm_loop_nacl, se_node_acl);
 795
 796         kfree(tl_nacl);
 797 }
 798
 799 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 800 {
 801         return 1;
 802 }
 803
 804 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 805 {
 806         return 1;
 807 }
 808
 809 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 810 {
 811         return;
 812 }
 813
 814 static u32 tcm_loop_get_task_tag(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_tag;
 820 }
 821
 822 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 823 {
 824         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 825                         struct tcm_loop_cmd, tl_se_cmd);
 826
 827         return tl_cmd->sc_cmd_state;
 828 }
 829
 830 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 831 {
 832         return 0;
 833 }
 834
 835 static void tcm_loop_close_session(struct se_session *se_sess)
 836 {
 837         return;
 838 };
 839
 840 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 841 {
 842         /*
 843          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 844          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 845          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 846          * format with transport_generic_map_mem_to_cmd().
 847          *
 848          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 849          * object execution queue.
 850          */
 851         target_execute_cmd(se_cmd);
 852         return 0;
 853 }
 854
 855 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 856 {
 857         return 0;
 858 }
 859
 860 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 861 {
 862         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 863                                 struct tcm_loop_cmd, tl_se_cmd);
 864         struct scsi_cmnd *sc = tl_cmd->sc;
 865
 866         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 867                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 868
 869         sc->result = SAM_STAT_GOOD;
 870         set_host_byte(sc, DID_OK);
 871         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 872             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 873                 scsi_set_resid(sc, se_cmd->residual_count);
 874         sc->scsi_done(sc);
 875         return 0;
 876 }
 877
 878 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 879 {
 880         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 881                                 struct tcm_loop_cmd, tl_se_cmd);
 882         struct scsi_cmnd *sc = tl_cmd->sc;
 883
 884         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 885                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 886
 887         if (se_cmd->sense_buffer &&
 888            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 889             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 890
 891                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 892                                 SCSI_SENSE_BUFFERSIZE);
 893                 sc->result = SAM_STAT_CHECK_CONDITION;
 894                 set_driver_byte(sc, DRIVER_SENSE);
 895         } else
 896                 sc->result = se_cmd->scsi_status;
 897
 898         set_host_byte(sc, DID_OK);
 899         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 900             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 901                 scsi_set_resid(sc, se_cmd->residual_count);
 902         sc->scsi_done(sc);
 903         return 0;
 904 }
 905
 906 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 907 {
 908         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 909         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 910         /*
 911          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 912          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 913          */
 914         atomic_set(&tl_tmr->tmr_complete, 1);
 915         wake_up(&tl_tmr->tl_tmr_wait);
 916 }
 917
 918 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 919 {
 920         switch (tl_hba->tl_proto_id) {
 921         case SCSI_PROTOCOL_SAS:
 922                 return "SAS";
 923         case SCSI_PROTOCOL_FCP:
 924                 return "FCP";
 925         case SCSI_PROTOCOL_ISCSI:
 926                 return "iSCSI";
 927         default:
 928                 break;
 929         }
 930
 931         return "Unknown";
 932 }
 933
 934 /* Start items for tcm_loop_port_cit */
 935
 936 static int tcm_loop_port_link(
 937         struct se_portal_group *se_tpg,
 938         struct se_lun *lun)
 939 {
 940         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 941                                 struct tcm_loop_tpg, tl_se_tpg);
 942         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 943
 944         atomic_inc(&tl_tpg->tl_tpg_port_count);
 945         smp_mb__after_atomic_inc();
 946         /*
 947          * Add Linux/SCSI struct scsi_device by HCTL
 948          */
 949         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 950
 951         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 952         return 0;
 953 }
 954
 955 static void tcm_loop_port_unlink(
 956         struct se_portal_group *se_tpg,
 957         struct se_lun *se_lun)
 958 {
 959         struct scsi_device *sd;
 960         struct tcm_loop_hba *tl_hba;
 961         struct tcm_loop_tpg *tl_tpg;
 962
 963         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 964         tl_hba = tl_tpg->tl_hba;
 965
 966         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 967                                 se_lun->unpacked_lun);
 968         if (!sd) {
 969                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 970                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 971                 return;
 972         }
 973         /*
 974          * Remove Linux/SCSI struct scsi_device by HCTL
 975          */
 976         scsi_remove_device(sd);
 977         scsi_device_put(sd);
 978
 979         atomic_dec(&tl_tpg->tl_tpg_port_count);
 980         smp_mb__after_atomic_dec();
 981
 982         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 983 }
 984
 985 /* End items for tcm_loop_port_cit */
 986
 987 /* Start items for tcm_loop_nexus_cit */
 988
 989 static int tcm_loop_make_nexus(
 990         struct tcm_loop_tpg *tl_tpg,
 991         const char *name)
 992 {
 993         struct se_portal_group *se_tpg;
 994         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 995         struct tcm_loop_nexus *tl_nexus;
 996         int ret = -ENOMEM;
 997
 998         if (tl_tpg->tl_hba->tl_nexus) {
 999                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
1000                 return -EEXIST;
1001         }
1002         se_tpg = &tl_tpg->tl_se_tpg;
1003
1004         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1005         if (!tl_nexus) {
1006                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
1007                 return -ENOMEM;
1008         }
1009         /*
1010          * Initialize the struct se_session pointer
1011          */
1012         tl_nexus->se_sess = transport_init_session();
1013         if (IS_ERR(tl_nexus->se_sess)) {
1014                 ret = PTR_ERR(tl_nexus->se_sess);
1015                 goto out;
1016         }
1017         /*
1018          * Since we are running in 'demo mode' this call with generate a
1019          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1020          * Initiator port name of the passed configfs group 'name'.
1021          */
1022         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1023                                 se_tpg, (unsigned char *)name);
1024         if (!tl_nexus->se_sess->se_node_acl) {
1025                 transport_free_session(tl_nexus->se_sess);
1026                 goto out;
1027         }
1028         /*
1029          * Now, register the SAS I_T Nexus as active with the call to
1030          * transport_register_session()
1031          */
1032         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1033                         tl_nexus->se_sess, tl_nexus);
1034         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1035         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1036                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1037                 name);
1038         return 0;
1039
1040 out:
1041         kfree(tl_nexus);
1042         return ret;
1043 }
1044
1045 static int tcm_loop_drop_nexus(
1046         struct tcm_loop_tpg *tpg)
1047 {
1048         struct se_session *se_sess;
1049         struct tcm_loop_nexus *tl_nexus;
1050         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1051
1052         if (!tl_hba)
1053                 return -ENODEV;
1054
1055         tl_nexus = tl_hba->tl_nexus;
1056         if (!tl_nexus)
1057                 return -ENODEV;
1058
1059         se_sess = tl_nexus->se_sess;
1060         if (!se_sess)
1061                 return -ENODEV;
1062
1063         if (atomic_read(&tpg->tl_tpg_port_count)) {
1064                 pr_err("Unable to remove TCM_Loop I_T Nexus with"
1065                         " active TPG port count: %d\n",
1066                         atomic_read(&tpg->tl_tpg_port_count));
1067                 return -EPERM;
1068         }
1069
1070         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1071                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1072                 tl_nexus->se_sess->se_node_acl->initiatorname);
1073         /*
1074          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1075          */
1076         transport_deregister_session(tl_nexus->se_sess);
1077         tpg->tl_hba->tl_nexus = NULL;
1078         kfree(tl_nexus);
1079         return 0;
1080 }
1081
1082 /* End items for tcm_loop_nexus_cit */
1083
1084 static ssize_t tcm_loop_tpg_show_nexus(
1085         struct se_portal_group *se_tpg,
1086         char *page)
1087 {
1088         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1089                         struct tcm_loop_tpg, tl_se_tpg);
1090         struct tcm_loop_nexus *tl_nexus;
1091         ssize_t ret;
1092
1093         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1094         if (!tl_nexus)
1095                 return -ENODEV;
1096
1097         ret = snprintf(page, PAGE_SIZE, "%s\n",
1098                 tl_nexus->se_sess->se_node_acl->initiatorname);
1099
1100         return ret;
1101 }
1102
1103 static ssize_t tcm_loop_tpg_store_nexus(
1104         struct se_portal_group *se_tpg,
1105         const char *page,
1106         size_t count)
1107 {
1108         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1109                         struct tcm_loop_tpg, tl_se_tpg);
1110         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1111         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1112         int ret;
1113         /*
1114          * Shutdown the active I_T nexus if 'NULL' is passed..
1115          */
1116         if (!strncmp(page, "NULL", 4)) {
1117                 ret = tcm_loop_drop_nexus(tl_tpg);
1118                 return (!ret) ? count : ret;
1119         }
1120         /*
1121          * Otherwise make sure the passed virtual Initiator port WWN matches
1122          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1123          * tcm_loop_make_nexus()
1124          */
1125         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1126                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1127                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1128                 return -EINVAL;
1129         }
1130         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1131
1132         ptr = strstr(i_port, "naa.");
1133         if (ptr) {
1134                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1135                         pr_err("Passed SAS Initiator Port %s does not"
1136                                 " match target port protoid: %s\n", i_port,
1137                                 tcm_loop_dump_proto_id(tl_hba));
1138                         return -EINVAL;
1139                 }
1140                 port_ptr = &i_port[0];
1141                 goto check_newline;
1142         }
1143         ptr = strstr(i_port, "fc.");
1144         if (ptr) {
1145                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1146                         pr_err("Passed FCP Initiator Port %s does not"
1147                                 " match target port protoid: %s\n", i_port,
1148                                 tcm_loop_dump_proto_id(tl_hba));
1149                         return -EINVAL;
1150                 }
1151                 port_ptr = &i_port[3]; /* Skip over "fc." */
1152                 goto check_newline;
1153         }
1154         ptr = strstr(i_port, "iqn.");
1155         if (ptr) {
1156                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1157                         pr_err("Passed iSCSI Initiator Port %s does not"
1158                                 " match target port protoid: %s\n", i_port,
1159                                 tcm_loop_dump_proto_id(tl_hba));
1160                         return -EINVAL;
1161                 }
1162                 port_ptr = &i_port[0];
1163                 goto check_newline;
1164         }
1165         pr_err("Unable to locate prefix for emulated Initiator Port:"
1166                         " %s\n", i_port);
1167         return -EINVAL;
1168         /*
1169          * Clear any trailing newline for the NAA WWN
1170          */
1171 check_newline:
1172         if (i_port[strlen(i_port)-1] == '\n')
1173                 i_port[strlen(i_port)-1] = '\0';
1174
1175         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1176         if (ret < 0)
1177                 return ret;
1178
1179         return count;
1180 }
1181
1182 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1183
1184 static ssize_t tcm_loop_tpg_show_transport_status(
1185         struct se_portal_group *se_tpg,
1186         char *page)
1187 {
1188         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1189                         struct tcm_loop_tpg, tl_se_tpg);
1190         const char *status = NULL;
1191         ssize_t ret = -EINVAL;
1192
1193         switch (tl_tpg->tl_transport_status) {
1194         case TCM_TRANSPORT_ONLINE:
1195                 status = "online";
1196                 break;
1197         case TCM_TRANSPORT_OFFLINE:
1198                 status = "offline";
1199                 break;
1200         default:
1201                 break;
1202         }
1203
1204         if (status)
1205                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1206
1207         return ret;
1208 }
1209
1210 static ssize_t tcm_loop_tpg_store_transport_status(
1211         struct se_portal_group *se_tpg,
1212         const char *page,
1213         size_t count)
1214 {
1215         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1216                         struct tcm_loop_tpg, tl_se_tpg);
1217
1218         if (!strncmp(page, "online", 6)) {
1219                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1220                 return count;
1221         }
1222         if (!strncmp(page, "offline", 7)) {
1223                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1224                 return count;
1225         }
1226         return -EINVAL;
1227 }
1228
1229 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1230
1231 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1232         &tcm_loop_tpg_nexus.attr,
1233         &tcm_loop_tpg_transport_status.attr,
1234         NULL,
1235 };
1236
1237 /* Start items for tcm_loop_naa_cit */
1238
1239 static struct se_portal_group *tcm_loop_make_naa_tpg(
1240         struct se_wwn *wwn,
1241         struct config_group *group,
1242         const char *name)
1243 {
1244         struct tcm_loop_hba *tl_hba = container_of(wwn,
1245                         struct tcm_loop_hba, tl_hba_wwn);
1246         struct tcm_loop_tpg *tl_tpg;
1247         char *tpgt_str, *end_ptr;
1248         int ret;
1249         unsigned short int tpgt;
1250
1251         tpgt_str = strstr(name, "tpgt_");
1252         if (!tpgt_str) {
1253                 pr_err("Unable to locate \"tpgt_#\" directory"
1254                                 " group\n");
1255                 return ERR_PTR(-EINVAL);
1256         }
1257         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1258         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1259
1260         if (tpgt >= TL_TPGS_PER_HBA) {
1261                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1262                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1263                 return ERR_PTR(-EINVAL);
1264         }
1265         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1266         tl_tpg->tl_hba = tl_hba;
1267         tl_tpg->tl_tpgt = tpgt;
1268         /*
1269          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1270          */
1271         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1272                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1273                         TRANSPORT_TPG_TYPE_NORMAL);
1274         if (ret < 0)
1275                 return ERR_PTR(-ENOMEM);
1276
1277         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1278                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1279                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1280
1281         return &tl_tpg->tl_se_tpg;
1282 }
1283
1284 static void tcm_loop_drop_naa_tpg(
1285         struct se_portal_group *se_tpg)
1286 {
1287         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1288         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1289                                 struct tcm_loop_tpg, tl_se_tpg);
1290         struct tcm_loop_hba *tl_hba;
1291         unsigned short tpgt;
1292
1293         tl_hba = tl_tpg->tl_hba;
1294         tpgt = tl_tpg->tl_tpgt;
1295         /*
1296          * Release the I_T Nexus for the Virtual SAS link if present
1297          */
1298         tcm_loop_drop_nexus(tl_tpg);
1299         /*
1300          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1301          */
1302         core_tpg_deregister(se_tpg);
1303
1304         tl_tpg->tl_hba = NULL;
1305         tl_tpg->tl_tpgt = 0;
1306
1307         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1308                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1309                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1310 }
1311
1312 /* End items for tcm_loop_naa_cit */
1313
1314 /* Start items for tcm_loop_cit */
1315
1316 static struct se_wwn *tcm_loop_make_scsi_hba(
1317         struct target_fabric_configfs *tf,
1318         struct config_group *group,
1319         const char *name)
1320 {
1321         struct tcm_loop_hba *tl_hba;
1322         struct Scsi_Host *sh;
1323         char *ptr;
1324         int ret, off = 0;
1325
1326         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1327         if (!tl_hba) {
1328                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1329                 return ERR_PTR(-ENOMEM);
1330         }
1331         /*
1332          * Determine the emulated Protocol Identifier and Target Port Name
1333          * based on the incoming configfs directory name.
1334          */
1335         ptr = strstr(name, "naa.");
1336         if (ptr) {
1337                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1338                 goto check_len;
1339         }
1340         ptr = strstr(name, "fc.");
1341         if (ptr) {
1342                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1343                 off = 3; /* Skip over "fc." */
1344                 goto check_len;
1345         }
1346         ptr = strstr(name, "iqn.");
1347         if (!ptr) {
1348                 pr_err("Unable to locate prefix for emulated Target "
1349                                 "Port: %s\n", name);
1350                 ret = -EINVAL;
1351                 goto out;
1352         }
1353         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1354
1355 check_len:
1356         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1357                 pr_err("Emulated NAA %s Address: %s, exceeds"
1358                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1359                         TL_WWN_ADDR_LEN);
1360                 ret = -EINVAL;
1361                 goto out;
1362         }
1363         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1364
1365         /*
1366          * Call device_register(tl_hba->dev) to register the emulated
1367          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1368          * device_register() callbacks in tcm_loop_driver_probe()
1369          */
1370         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1371         if (ret)
1372                 goto out;
1373
1374         sh = tl_hba->sh;
1375         tcm_loop_hba_no_cnt++;
1376         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1377                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1378                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1379
1380         return &tl_hba->tl_hba_wwn;
1381 out:
1382         kfree(tl_hba);
1383         return ERR_PTR(ret);
1384 }
1385
1386 static void tcm_loop_drop_scsi_hba(
1387         struct se_wwn *wwn)
1388 {
1389         struct tcm_loop_hba *tl_hba = container_of(wwn,
1390                                 struct tcm_loop_hba, tl_hba_wwn);
1391
1392         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1393                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1394                 tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1395         /*
1396          * Call device_unregister() on the original tl_hba->dev.
1397          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1398          * release *tl_hba;
1399          */
1400         device_unregister(&tl_hba->dev);
1401 }
1402
1403 /* Start items for tcm_loop_cit */
1404 static ssize_t tcm_loop_wwn_show_attr_version(
1405         struct target_fabric_configfs *tf,
1406         char *page)
1407 {
1408         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1409 }
1410
1411 TF_WWN_ATTR_RO(tcm_loop, version);
1412
1413 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1414         &tcm_loop_wwn_version.attr,
1415         NULL,
1416 };
1417
1418 /* End items for tcm_loop_cit */
1419
1420 static int tcm_loop_register_configfs(void)
1421 {
1422         struct target_fabric_configfs *fabric;
1423         int ret;
1424         /*
1425          * Set the TCM Loop HBA counter to zero
1426          */
1427         tcm_loop_hba_no_cnt = 0;
1428         /*
1429          * Register the top level struct config_item_type with TCM core
1430          */
1431         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1432         if (IS_ERR(fabric)) {
1433                 pr_err("tcm_loop_register_configfs() failed!\n");
1434                 return PTR_ERR(fabric);
1435         }
1436         /*
1437          * Setup the fabric API of function pointers used by target_core_mod
1438          */
1439         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1440         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1441         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1442         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1443         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1444         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1445         fabric->tf_ops.tpg_get_pr_transport_id_len =
1446                                         &tcm_loop_get_pr_transport_id_len;
1447         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1448                                         &tcm_loop_parse_pr_out_transport_id;
1449         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1450         fabric->tf_ops.tpg_check_demo_mode_cache =
1451                                         &tcm_loop_check_demo_mode_cache;
1452         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1453                                         &tcm_loop_check_demo_mode_write_protect;
1454         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1455                                         &tcm_loop_check_prod_mode_write_protect;
1456         /*
1457          * The TCM loopback fabric module runs in demo-mode to a local
1458          * virtual SCSI device, so fabric dependent initator ACLs are
1459          * not required.
1460          */
1461         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1462         fabric->tf_ops.tpg_release_fabric_acl =
1463                                         &tcm_loop_tpg_release_fabric_acl;
1464         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1465         /*
1466          * Used for setting up remaining TCM resources in process context
1467          */
1468         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1469         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1470         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1471         fabric->tf_ops.close_session = &tcm_loop_close_session;
1472         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1473         fabric->tf_ops.sess_get_initiator_sid = NULL;
1474         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1475         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1476         /*
1477          * Not used for TCM loopback
1478          */
1479         fabric->tf_ops.set_default_node_attributes =
1480                                         &tcm_loop_set_default_node_attributes;
1481         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1482         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1483         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1484         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1485         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1486
1487         /*
1488          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1489          */
1490         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1491         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1492         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1493         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1494         /*
1495          * fabric_post_link() and fabric_pre_unlink() are used for
1496          * registration and release of TCM Loop Virtual SCSI LUNs.
1497          */
1498         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1499         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1500         fabric->tf_ops.fabric_make_np = NULL;
1501         fabric->tf_ops.fabric_drop_np = NULL;
1502         /*
1503          * Setup default attribute lists for various fabric->tf_cit_tmpl
1504          */
1505         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1506         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1507         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1508         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1509         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1510         /*
1511          * Once fabric->tf_ops has been setup, now register the fabric for
1512          * use within TCM
1513          */
1514         ret = target_fabric_configfs_register(fabric);
1515         if (ret < 0) {
1516                 pr_err("target_fabric_configfs_register() for"
1517                                 " TCM_Loop failed!\n");
1518                 target_fabric_configfs_free(fabric);
1519                 return -1;
1520         }
1521         /*
1522          * Setup our local pointer to *fabric.
1523          */
1524         tcm_loop_fabric_configfs = fabric;
1525         pr_debug("TCM_LOOP[0] - Set fabric ->"
1526                         " tcm_loop_fabric_configfs\n");
1527         return 0;
1528 }
1529
1530 static void tcm_loop_deregister_configfs(void)
1531 {
1532         if (!tcm_loop_fabric_configfs)
1533                 return;
1534
1535         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1536         tcm_loop_fabric_configfs = NULL;
1537         pr_debug("TCM_LOOP[0] - Cleared"
1538                                 " tcm_loop_fabric_configfs\n");
1539 }
1540
1541 static int __init tcm_loop_fabric_init(void)
1542 {
1543         int ret = -ENOMEM;
1544
1545         tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1546         if (!tcm_loop_workqueue)
1547                 goto out;
1548
1549         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1550                                 sizeof(struct tcm_loop_cmd),
1551                                 __alignof__(struct tcm_loop_cmd),
1552                                 0, NULL);
1553         if (!tcm_loop_cmd_cache) {
1554                 pr_debug("kmem_cache_create() for"
1555                         " tcm_loop_cmd_cache failed\n");
1556                 goto out_destroy_workqueue;
1557         }
1558
1559         ret = tcm_loop_alloc_core_bus();
1560         if (ret)
1561                 goto out_destroy_cache;
1562
1563         ret = tcm_loop_register_configfs();
1564         if (ret)
1565                 goto out_release_core_bus;
1566
1567         return 0;
1568
1569 out_release_core_bus:
1570         tcm_loop_release_core_bus();
1571 out_destroy_cache:
1572         kmem_cache_destroy(tcm_loop_cmd_cache);
1573 out_destroy_workqueue:
1574         destroy_workqueue(tcm_loop_workqueue);
1575 out:
1576         return ret;
1577 }
1578
1579 static void __exit tcm_loop_fabric_exit(void)
1580 {
1581         tcm_loop_deregister_configfs();
1582         tcm_loop_release_core_bus();
1583         kmem_cache_destroy(tcm_loop_cmd_cache);
1584         destroy_workqueue(tcm_loop_workqueue);
1585 }
1586
1587 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1588 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1589 MODULE_LICENSE("GPL");
1590 module_init(tcm_loop_fabric_init);
1591 module_exit(tcm_loop_fabric_exit);