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
  38 #include "tcm_loop.h"
  39
  40 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  41
  42 static struct kmem_cache *tcm_loop_cmd_cache;
  43
  44 static int tcm_loop_hba_no_cnt;
  45
  46 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
  47
  48 static unsigned int tcm_loop_nr_hw_queues = 1;
  49 module_param_named(nr_hw_queues, tcm_loop_nr_hw_queues, uint, 0644);
  50
  51 static unsigned int tcm_loop_can_queue = 1024;
  52 module_param_named(can_queue, tcm_loop_can_queue, uint, 0644);
  53
  54 static unsigned int tcm_loop_cmd_per_lun = 1024;
  55 module_param_named(cmd_per_lun, tcm_loop_cmd_per_lun, uint, 0644);
  56
  57 /*
  58  * Called from struct target_core_fabric_ops->check_stop_free()
  59  */
  60 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
  61 {
  62         return transport_generic_free_cmd(se_cmd, 0);
  63 }
  64
  65 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
  66 {
  67         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
  68                                 struct tcm_loop_cmd, tl_se_cmd);
  69         struct scsi_cmnd *sc = tl_cmd->sc;
  70
  71         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
  72                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
  73         else
  74                 scsi_done(sc);
  75 }
  76
  77 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
  78 {
  79         seq_puts(m, "tcm_loop_proc_info()\n");
  80         return 0;
  81 }
  82
  83 static int tcm_loop_driver_probe(struct device *);
  84 static void tcm_loop_driver_remove(struct device *);
  85
  86 static struct bus_type tcm_loop_lld_bus = {
  87         .name                   = "tcm_loop_bus",
  88         .probe                  = tcm_loop_driver_probe,
  89         .remove                 = tcm_loop_driver_remove,
  90 };
  91
  92 static struct device_driver tcm_loop_driverfs = {
  93         .name                   = "tcm_loop",
  94         .bus                    = &tcm_loop_lld_bus,
  95 };
  96 /*
  97  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
  98  */
  99 static struct device *tcm_loop_primary;
 100
 101 static void tcm_loop_target_queue_cmd(struct tcm_loop_cmd *tl_cmd)
 102 {
 103         struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
 104         struct scsi_cmnd *sc = tl_cmd->sc;
 105         struct tcm_loop_nexus *tl_nexus;
 106         struct tcm_loop_hba *tl_hba;
 107         struct tcm_loop_tpg *tl_tpg;
 108         struct scatterlist *sgl_bidi = NULL;
 109         u32 sgl_bidi_count = 0, transfer_length;
 110
 111         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 112         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 113
 114         /*
 115          * Ensure that this tl_tpg reference from the incoming sc->device->id
 116          * has already been configured via tcm_loop_make_naa_tpg().
 117          */
 118         if (!tl_tpg->tl_hba) {
 119                 set_host_byte(sc, DID_NO_CONNECT);
 120                 goto out_done;
 121         }
 122         if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
 123                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 124                 goto out_done;
 125         }
 126         tl_nexus = tl_tpg->tl_nexus;
 127         if (!tl_nexus) {
 128                 scmd_printk(KERN_ERR, sc,
 129                             "TCM_Loop I_T Nexus does not exist\n");
 130                 set_host_byte(sc, DID_ERROR);
 131                 goto out_done;
 132         }
 133
 134         transfer_length = scsi_transfer_length(sc);
 135         if (!scsi_prot_sg_count(sc) &&
 136             scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
 137                 se_cmd->prot_pto = true;
 138                 /*
 139                  * loopback transport doesn't support
 140                  * WRITE_GENERATE, READ_STRIP protection
 141                  * information operations, go ahead unprotected.
 142                  */
 143                 transfer_length = scsi_bufflen(sc);
 144         }
 145
 146         se_cmd->tag = tl_cmd->sc_cmd_tag;
 147         target_init_cmd(se_cmd, tl_nexus->se_sess, &tl_cmd->tl_sense_buf[0],
 148                         tl_cmd->sc->device->lun, transfer_length,
 149                         TCM_SIMPLE_TAG, sc->sc_data_direction, 0);
 150
 151         if (target_submit_prep(se_cmd, sc->cmnd, scsi_sglist(sc),
 152                                scsi_sg_count(sc), sgl_bidi, sgl_bidi_count,
 153                                scsi_prot_sglist(sc), scsi_prot_sg_count(sc),
 154                                GFP_ATOMIC))
 155                 return;
 156
 157         target_queue_submission(se_cmd);
 158         return;
 159
 160 out_done:
 161         scsi_done(sc);
 162 }
 163
 164 /*
 165  * ->queuecommand can be and usually is called from interrupt context, so
 166  * defer the actual submission to a workqueue.
 167  */
 168 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 169 {
 170         struct tcm_loop_cmd *tl_cmd = scsi_cmd_priv(sc);
 171
 172         pr_debug("%s() %d:%d:%d:%llu got CDB: 0x%02x scsi_buf_len: %u\n",
 173                  __func__, sc->device->host->host_no, sc->device->id,
 174                  sc->device->channel, sc->device->lun, sc->cmnd[0],
 175                  scsi_bufflen(sc));
 176
 177         memset(tl_cmd, 0, sizeof(*tl_cmd));
 178         tl_cmd->sc = sc;
 179         tl_cmd->sc_cmd_tag = scsi_cmd_to_rq(sc)->tag;
 180
 181         tcm_loop_target_queue_cmd(tl_cmd);
 182         return 0;
 183 }
 184
 185 /*
 186  * Called from SCSI EH process context to issue a LUN_RESET TMR
 187  * to struct scsi_device
 188  */
 189 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 190                               u64 lun, int task, enum tcm_tmreq_table tmr)
 191 {
 192         struct se_cmd *se_cmd;
 193         struct se_session *se_sess;
 194         struct tcm_loop_nexus *tl_nexus;
 195         struct tcm_loop_cmd *tl_cmd;
 196         int ret = TMR_FUNCTION_FAILED, rc;
 197
 198         /*
 199          * Locate the tl_nexus and se_sess pointers
 200          */
 201         tl_nexus = tl_tpg->tl_nexus;
 202         if (!tl_nexus) {
 203                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 204                 return ret;
 205         }
 206
 207         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 208         if (!tl_cmd)
 209                 return ret;
 210
 211         init_completion(&tl_cmd->tmr_done);
 212
 213         se_cmd = &tl_cmd->tl_se_cmd;
 214         se_sess = tl_tpg->tl_nexus->se_sess;
 215
 216         rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun,
 217                                NULL, tmr, GFP_KERNEL, task,
 218                                TARGET_SCF_ACK_KREF);
 219         if (rc < 0)
 220                 goto release;
 221         wait_for_completion(&tl_cmd->tmr_done);
 222         ret = se_cmd->se_tmr_req->response;
 223         target_put_sess_cmd(se_cmd);
 224
 225 out:
 226         return ret;
 227
 228 release:
 229         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 230         goto out;
 231 }
 232
 233 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 234 {
 235         struct tcm_loop_hba *tl_hba;
 236         struct tcm_loop_tpg *tl_tpg;
 237         int ret;
 238
 239         /*
 240          * Locate the tcm_loop_hba_t pointer
 241          */
 242         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 243         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 244         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 245                                  scsi_cmd_to_rq(sc)->tag, TMR_ABORT_TASK);
 246         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 247 }
 248
 249 /*
 250  * Called from SCSI EH process context to issue a LUN_RESET TMR
 251  * to struct scsi_device
 252  */
 253 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 254 {
 255         struct tcm_loop_hba *tl_hba;
 256         struct tcm_loop_tpg *tl_tpg;
 257         int ret;
 258
 259         /*
 260          * Locate the tcm_loop_hba_t pointer
 261          */
 262         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 263         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 264
 265         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 266                                  0, TMR_LUN_RESET);
 267         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 268 }
 269
 270 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 271 {
 272         struct tcm_loop_hba *tl_hba;
 273         struct tcm_loop_tpg *tl_tpg;
 274
 275         /*
 276          * Locate the tcm_loop_hba_t pointer
 277          */
 278         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 279         if (!tl_hba) {
 280                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 281                 return FAILED;
 282         }
 283         /*
 284          * Locate the tl_tpg pointer from TargetID in sc->device->id
 285          */
 286         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 287         if (tl_tpg) {
 288                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 289                 return SUCCESS;
 290         }
 291         return FAILED;
 292 }
 293
 294 static const struct scsi_host_template tcm_loop_driver_template = {
 295         .show_info              = tcm_loop_show_info,
 296         .proc_name              = "tcm_loopback",
 297         .name                   = "TCM_Loopback",
 298         .queuecommand           = tcm_loop_queuecommand,
 299         .change_queue_depth     = scsi_change_queue_depth,
 300         .eh_abort_handler = tcm_loop_abort_task,
 301         .eh_device_reset_handler = tcm_loop_device_reset,
 302         .eh_target_reset_handler = tcm_loop_target_reset,
 303         .this_id                = -1,
 304         .sg_tablesize           = 256,
 305         .max_sectors            = 0xFFFF,
 306         .dma_boundary           = PAGE_SIZE - 1,
 307         .module                 = THIS_MODULE,
 308         .track_queue_depth      = 1,
 309         .cmd_size               = sizeof(struct tcm_loop_cmd),
 310 };
 311
 312 static int tcm_loop_driver_probe(struct device *dev)
 313 {
 314         struct tcm_loop_hba *tl_hba;
 315         struct Scsi_Host *sh;
 316         int error, host_prot;
 317
 318         tl_hba = to_tcm_loop_hba(dev);
 319
 320         sh = scsi_host_alloc(&tcm_loop_driver_template,
 321                         sizeof(struct tcm_loop_hba));
 322         if (!sh) {
 323                 pr_err("Unable to allocate struct scsi_host\n");
 324                 return -ENODEV;
 325         }
 326         tl_hba->sh = sh;
 327
 328         /*
 329          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 330          */
 331         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 332         /*
 333          * Setup single ID, Channel and LUN for now..
 334          */
 335         sh->max_id = 2;
 336         sh->max_lun = 0;
 337         sh->max_channel = 0;
 338         sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 339         sh->nr_hw_queues = tcm_loop_nr_hw_queues;
 340         sh->can_queue = tcm_loop_can_queue;
 341         sh->cmd_per_lun = tcm_loop_cmd_per_lun;
 342
 343         host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
 344                     SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
 345                     SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
 346
 347         scsi_host_set_prot(sh, host_prot);
 348         scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
 349
 350         error = scsi_add_host(sh, &tl_hba->dev);
 351         if (error) {
 352                 pr_err("%s: scsi_add_host failed\n", __func__);
 353                 scsi_host_put(sh);
 354                 return -ENODEV;
 355         }
 356         return 0;
 357 }
 358
 359 static void tcm_loop_driver_remove(struct device *dev)
 360 {
 361         struct tcm_loop_hba *tl_hba;
 362         struct Scsi_Host *sh;
 363
 364         tl_hba = to_tcm_loop_hba(dev);
 365         sh = tl_hba->sh;
 366
 367         scsi_remove_host(sh);
 368         scsi_host_put(sh);
 369 }
 370
 371 static void tcm_loop_release_adapter(struct device *dev)
 372 {
 373         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 374
 375         kfree(tl_hba);
 376 }
 377
 378 /*
 379  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 380  */
 381 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 382 {
 383         int ret;
 384
 385         tl_hba->dev.bus = &tcm_loop_lld_bus;
 386         tl_hba->dev.parent = tcm_loop_primary;
 387         tl_hba->dev.release = &tcm_loop_release_adapter;
 388         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 389
 390         ret = device_register(&tl_hba->dev);
 391         if (ret) {
 392                 pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
 393                 put_device(&tl_hba->dev);
 394                 return -ENODEV;
 395         }
 396
 397         return 0;
 398 }
 399
 400 /*
 401  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 402  * tcm_loop SCSI bus.
 403  */
 404 static int tcm_loop_alloc_core_bus(void)
 405 {
 406         int ret;
 407
 408         tcm_loop_primary = root_device_register("tcm_loop_0");
 409         if (IS_ERR(tcm_loop_primary)) {
 410                 pr_err("Unable to allocate tcm_loop_primary\n");
 411                 return PTR_ERR(tcm_loop_primary);
 412         }
 413
 414         ret = bus_register(&tcm_loop_lld_bus);
 415         if (ret) {
 416                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 417                 goto dev_unreg;
 418         }
 419
 420         ret = driver_register(&tcm_loop_driverfs);
 421         if (ret) {
 422                 pr_err("driver_register() failed for tcm_loop_driverfs\n");
 423                 goto bus_unreg;
 424         }
 425
 426         pr_debug("Initialized TCM Loop Core Bus\n");
 427         return ret;
 428
 429 bus_unreg:
 430         bus_unregister(&tcm_loop_lld_bus);
 431 dev_unreg:
 432         root_device_unregister(tcm_loop_primary);
 433         return ret;
 434 }
 435
 436 static void tcm_loop_release_core_bus(void)
 437 {
 438         driver_unregister(&tcm_loop_driverfs);
 439         bus_unregister(&tcm_loop_lld_bus);
 440         root_device_unregister(tcm_loop_primary);
 441
 442         pr_debug("Releasing TCM Loop Core BUS\n");
 443 }
 444
 445 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
 446 {
 447         return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 448 }
 449
 450 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 451 {
 452         /*
 453          * Return the passed NAA identifier for the Target Port
 454          */
 455         return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
 456 }
 457
 458 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 459 {
 460         /*
 461          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 462          * to represent the SCSI Target Port.
 463          */
 464         return tl_tpg(se_tpg)->tl_tpgt;
 465 }
 466
 467 /*
 468  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 469  * based upon the incoming fabric dependent SCSI Initiator Port
 470  */
 471 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 472 {
 473         return 1;
 474 }
 475
 476 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
 477 {
 478         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 479                                                    tl_se_tpg);
 480         return tl_tpg->tl_fabric_prot_type;
 481 }
 482
 483 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 484 {
 485         return 1;
 486 }
 487
 488 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 489 {
 490         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 491                         struct tcm_loop_cmd, tl_se_cmd);
 492
 493         return tl_cmd->sc_cmd_state;
 494 }
 495
 496 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 497 {
 498         /*
 499          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 500          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 501          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 502          * format with transport_generic_map_mem_to_cmd().
 503          *
 504          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 505          * object execution queue.
 506          */
 507         target_execute_cmd(se_cmd);
 508         return 0;
 509 }
 510
 511 static int tcm_loop_queue_data_or_status(const char *func,
 512                 struct se_cmd *se_cmd, u8 scsi_status)
 513 {
 514         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 515                                 struct tcm_loop_cmd, tl_se_cmd);
 516         struct scsi_cmnd *sc = tl_cmd->sc;
 517
 518         pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
 519                  func, sc, sc->cmnd[0]);
 520
 521         if (se_cmd->sense_buffer &&
 522            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 523             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 524
 525                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 526                                 SCSI_SENSE_BUFFERSIZE);
 527                 sc->result = SAM_STAT_CHECK_CONDITION;
 528         } else
 529                 sc->result = scsi_status;
 530
 531         set_host_byte(sc, DID_OK);
 532         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 533             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 534                 scsi_set_resid(sc, se_cmd->residual_count);
 535         return 0;
 536 }
 537
 538 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 539 {
 540         return tcm_loop_queue_data_or_status(__func__, se_cmd, SAM_STAT_GOOD);
 541 }
 542
 543 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 544 {
 545         return tcm_loop_queue_data_or_status(__func__,
 546                                              se_cmd, se_cmd->scsi_status);
 547 }
 548
 549 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 550 {
 551         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 552                                 struct tcm_loop_cmd, tl_se_cmd);
 553
 554         /* Wake up tcm_loop_issue_tmr(). */
 555         complete(&tl_cmd->tmr_done);
 556 }
 557
 558 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
 559 {
 560         return;
 561 }
 562
 563 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 564 {
 565         switch (tl_hba->tl_proto_id) {
 566         case SCSI_PROTOCOL_SAS:
 567                 return "SAS";
 568         case SCSI_PROTOCOL_FCP:
 569                 return "FCP";
 570         case SCSI_PROTOCOL_ISCSI:
 571                 return "iSCSI";
 572         default:
 573                 break;
 574         }
 575
 576         return "Unknown";
 577 }
 578
 579 /* Start items for tcm_loop_port_cit */
 580
 581 static int tcm_loop_port_link(
 582         struct se_portal_group *se_tpg,
 583         struct se_lun *lun)
 584 {
 585         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 586                                 struct tcm_loop_tpg, tl_se_tpg);
 587         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 588
 589         atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
 590         /*
 591          * Add Linux/SCSI struct scsi_device by HCTL
 592          */
 593         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 594
 595         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 596         return 0;
 597 }
 598
 599 static void tcm_loop_port_unlink(
 600         struct se_portal_group *se_tpg,
 601         struct se_lun *se_lun)
 602 {
 603         struct scsi_device *sd;
 604         struct tcm_loop_hba *tl_hba;
 605         struct tcm_loop_tpg *tl_tpg;
 606
 607         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 608         tl_hba = tl_tpg->tl_hba;
 609
 610         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 611                                 se_lun->unpacked_lun);
 612         if (!sd) {
 613                 pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
 614                        0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 615                 return;
 616         }
 617         /*
 618          * Remove Linux/SCSI struct scsi_device by HCTL
 619          */
 620         scsi_remove_device(sd);
 621         scsi_device_put(sd);
 622
 623         atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
 624
 625         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 626 }
 627
 628 /* End items for tcm_loop_port_cit */
 629
 630 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
 631                 struct config_item *item, char *page)
 632 {
 633         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 634         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 635                                                    tl_se_tpg);
 636
 637         return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
 638 }
 639
 640 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
 641                 struct config_item *item, const char *page, size_t count)
 642 {
 643         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 644         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 645                                                    tl_se_tpg);
 646         unsigned long val;
 647         int ret = kstrtoul(page, 0, &val);
 648
 649         if (ret) {
 650                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
 651                 return ret;
 652         }
 653         if (val != 0 && val != 1 && val != 3) {
 654                 pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
 655                 return -EINVAL;
 656         }
 657         tl_tpg->tl_fabric_prot_type = val;
 658
 659         return count;
 660 }
 661
 662 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
 663
 664 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
 665         &tcm_loop_tpg_attrib_attr_fabric_prot_type,
 666         NULL,
 667 };
 668
 669 /* Start items for tcm_loop_nexus_cit */
 670
 671 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
 672                                   struct se_session *se_sess, void *p)
 673 {
 674         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 675                                         struct tcm_loop_tpg, tl_se_tpg);
 676
 677         tl_tpg->tl_nexus = p;
 678         return 0;
 679 }
 680
 681 static int tcm_loop_make_nexus(
 682         struct tcm_loop_tpg *tl_tpg,
 683         const char *name)
 684 {
 685         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 686         struct tcm_loop_nexus *tl_nexus;
 687         int ret;
 688
 689         if (tl_tpg->tl_nexus) {
 690                 pr_debug("tl_tpg->tl_nexus already exists\n");
 691                 return -EEXIST;
 692         }
 693
 694         tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
 695         if (!tl_nexus)
 696                 return -ENOMEM;
 697
 698         tl_nexus->se_sess = target_setup_session(&tl_tpg->tl_se_tpg, 0, 0,
 699                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
 700                                         name, tl_nexus, tcm_loop_alloc_sess_cb);
 701         if (IS_ERR(tl_nexus->se_sess)) {
 702                 ret = PTR_ERR(tl_nexus->se_sess);
 703                 kfree(tl_nexus);
 704                 return ret;
 705         }
 706
 707         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
 708                  tcm_loop_dump_proto_id(tl_hba), name);
 709         return 0;
 710 }
 711
 712 static int tcm_loop_drop_nexus(
 713         struct tcm_loop_tpg *tpg)
 714 {
 715         struct se_session *se_sess;
 716         struct tcm_loop_nexus *tl_nexus;
 717
 718         tl_nexus = tpg->tl_nexus;
 719         if (!tl_nexus)
 720                 return -ENODEV;
 721
 722         se_sess = tl_nexus->se_sess;
 723         if (!se_sess)
 724                 return -ENODEV;
 725
 726         if (atomic_read(&tpg->tl_tpg_port_count)) {
 727                 pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
 728                        atomic_read(&tpg->tl_tpg_port_count));
 729                 return -EPERM;
 730         }
 731
 732         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
 733                  tcm_loop_dump_proto_id(tpg->tl_hba),
 734                  tl_nexus->se_sess->se_node_acl->initiatorname);
 735         /*
 736          * Release the SCSI I_T Nexus to the emulated Target Port
 737          */
 738         target_remove_session(se_sess);
 739         tpg->tl_nexus = NULL;
 740         kfree(tl_nexus);
 741         return 0;
 742 }
 743
 744 /* End items for tcm_loop_nexus_cit */
 745
 746 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
 747 {
 748         struct se_portal_group *se_tpg = to_tpg(item);
 749         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 750                         struct tcm_loop_tpg, tl_se_tpg);
 751         struct tcm_loop_nexus *tl_nexus;
 752         ssize_t ret;
 753
 754         tl_nexus = tl_tpg->tl_nexus;
 755         if (!tl_nexus)
 756                 return -ENODEV;
 757
 758         ret = snprintf(page, PAGE_SIZE, "%s\n",
 759                 tl_nexus->se_sess->se_node_acl->initiatorname);
 760
 761         return ret;
 762 }
 763
 764 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
 765                 const char *page, size_t count)
 766 {
 767         struct se_portal_group *se_tpg = to_tpg(item);
 768         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 769                         struct tcm_loop_tpg, tl_se_tpg);
 770         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 771         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
 772         int ret;
 773         /*
 774          * Shutdown the active I_T nexus if 'NULL' is passed..
 775          */
 776         if (!strncmp(page, "NULL", 4)) {
 777                 ret = tcm_loop_drop_nexus(tl_tpg);
 778                 return (!ret) ? count : ret;
 779         }
 780         /*
 781          * Otherwise make sure the passed virtual Initiator port WWN matches
 782          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
 783          * tcm_loop_make_nexus()
 784          */
 785         if (strlen(page) >= TL_WWN_ADDR_LEN) {
 786                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
 787                        page, TL_WWN_ADDR_LEN);
 788                 return -EINVAL;
 789         }
 790         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
 791
 792         ptr = strstr(i_port, "naa.");
 793         if (ptr) {
 794                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
 795                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
 796                                i_port, tcm_loop_dump_proto_id(tl_hba));
 797                         return -EINVAL;
 798                 }
 799                 port_ptr = &i_port[0];
 800                 goto check_newline;
 801         }
 802         ptr = strstr(i_port, "fc.");
 803         if (ptr) {
 804                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
 805                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
 806                                i_port, tcm_loop_dump_proto_id(tl_hba));
 807                         return -EINVAL;
 808                 }
 809                 port_ptr = &i_port[3]; /* Skip over "fc." */
 810                 goto check_newline;
 811         }
 812         ptr = strstr(i_port, "iqn.");
 813         if (ptr) {
 814                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
 815                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
 816                                i_port, tcm_loop_dump_proto_id(tl_hba));
 817                         return -EINVAL;
 818                 }
 819                 port_ptr = &i_port[0];
 820                 goto check_newline;
 821         }
 822         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
 823                i_port);
 824         return -EINVAL;
 825         /*
 826          * Clear any trailing newline for the NAA WWN
 827          */
 828 check_newline:
 829         if (i_port[strlen(i_port)-1] == '\n')
 830                 i_port[strlen(i_port)-1] = '\0';
 831
 832         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
 833         if (ret < 0)
 834                 return ret;
 835
 836         return count;
 837 }
 838
 839 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
 840                 char *page)
 841 {
 842         struct se_portal_group *se_tpg = to_tpg(item);
 843         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 844                         struct tcm_loop_tpg, tl_se_tpg);
 845         const char *status = NULL;
 846         ssize_t ret = -EINVAL;
 847
 848         switch (tl_tpg->tl_transport_status) {
 849         case TCM_TRANSPORT_ONLINE:
 850                 status = "online";
 851                 break;
 852         case TCM_TRANSPORT_OFFLINE:
 853                 status = "offline";
 854                 break;
 855         default:
 856                 break;
 857         }
 858
 859         if (status)
 860                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
 861
 862         return ret;
 863 }
 864
 865 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
 866                 const char *page, size_t count)
 867 {
 868         struct se_portal_group *se_tpg = to_tpg(item);
 869         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 870                         struct tcm_loop_tpg, tl_se_tpg);
 871
 872         if (!strncmp(page, "online", 6)) {
 873                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 874                 return count;
 875         }
 876         if (!strncmp(page, "offline", 7)) {
 877                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
 878                 if (tl_tpg->tl_nexus) {
 879                         struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
 880
 881                         core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
 882                 }
 883                 return count;
 884         }
 885         return -EINVAL;
 886 }
 887
 888 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
 889                                          char *page)
 890 {
 891         struct se_portal_group *se_tpg = to_tpg(item);
 892         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 893                         struct tcm_loop_tpg, tl_se_tpg);
 894         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 895
 896         return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
 897                         tl_hba->sh->host_no, tl_tpg->tl_tpgt);
 898 }
 899
 900 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
 901 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
 902 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
 903
 904 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
 905         &tcm_loop_tpg_attr_nexus,
 906         &tcm_loop_tpg_attr_transport_status,
 907         &tcm_loop_tpg_attr_address,
 908         NULL,
 909 };
 910
 911 /* Start items for tcm_loop_naa_cit */
 912
 913 static struct se_portal_group *tcm_loop_make_naa_tpg(struct se_wwn *wwn,
 914                                                      const char *name)
 915 {
 916         struct tcm_loop_hba *tl_hba = container_of(wwn,
 917                         struct tcm_loop_hba, tl_hba_wwn);
 918         struct tcm_loop_tpg *tl_tpg;
 919         int ret;
 920         unsigned long tpgt;
 921
 922         if (strstr(name, "tpgt_") != name) {
 923                 pr_err("Unable to locate \"tpgt_#\" directory group\n");
 924                 return ERR_PTR(-EINVAL);
 925         }
 926         if (kstrtoul(name+5, 10, &tpgt))
 927                 return ERR_PTR(-EINVAL);
 928
 929         if (tpgt >= TL_TPGS_PER_HBA) {
 930                 pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
 931                        tpgt, TL_TPGS_PER_HBA);
 932                 return ERR_PTR(-EINVAL);
 933         }
 934         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
 935         tl_tpg->tl_hba = tl_hba;
 936         tl_tpg->tl_tpgt = tpgt;
 937         /*
 938          * Register the tl_tpg as a emulated TCM Target Endpoint
 939          */
 940         ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
 941         if (ret < 0)
 942                 return ERR_PTR(-ENOMEM);
 943
 944         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
 945                  tcm_loop_dump_proto_id(tl_hba),
 946                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
 947         return &tl_tpg->tl_se_tpg;
 948 }
 949
 950 static void tcm_loop_drop_naa_tpg(
 951         struct se_portal_group *se_tpg)
 952 {
 953         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
 954         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 955                                 struct tcm_loop_tpg, tl_se_tpg);
 956         struct tcm_loop_hba *tl_hba;
 957         unsigned short tpgt;
 958
 959         tl_hba = tl_tpg->tl_hba;
 960         tpgt = tl_tpg->tl_tpgt;
 961         /*
 962          * Release the I_T Nexus for the Virtual target link if present
 963          */
 964         tcm_loop_drop_nexus(tl_tpg);
 965         /*
 966          * Deregister the tl_tpg as a emulated TCM Target Endpoint
 967          */
 968         core_tpg_deregister(se_tpg);
 969
 970         tl_tpg->tl_hba = NULL;
 971         tl_tpg->tl_tpgt = 0;
 972
 973         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
 974                  tcm_loop_dump_proto_id(tl_hba),
 975                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
 976 }
 977
 978 /* End items for tcm_loop_naa_cit */
 979
 980 /* Start items for tcm_loop_cit */
 981
 982 static struct se_wwn *tcm_loop_make_scsi_hba(
 983         struct target_fabric_configfs *tf,
 984         struct config_group *group,
 985         const char *name)
 986 {
 987         struct tcm_loop_hba *tl_hba;
 988         struct Scsi_Host *sh;
 989         char *ptr;
 990         int ret, off = 0;
 991
 992         tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
 993         if (!tl_hba)
 994                 return ERR_PTR(-ENOMEM);
 995
 996         /*
 997          * Determine the emulated Protocol Identifier and Target Port Name
 998          * based on the incoming configfs directory name.
 999          */
1000         ptr = strstr(name, "naa.");
1001         if (ptr) {
1002                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1003                 goto check_len;
1004         }
1005         ptr = strstr(name, "fc.");
1006         if (ptr) {
1007                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1008                 off = 3; /* Skip over "fc." */
1009                 goto check_len;
1010         }
1011         ptr = strstr(name, "iqn.");
1012         if (!ptr) {
1013                 pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1014                        name);
1015                 ret = -EINVAL;
1016                 goto out;
1017         }
1018         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1019
1020 check_len:
1021         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1022                 pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1023                        name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1024                 ret = -EINVAL;
1025                 goto out;
1026         }
1027         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1028
1029         /*
1030          * Call device_register(tl_hba->dev) to register the emulated
1031          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1032          * device_register() callbacks in tcm_loop_driver_probe()
1033          */
1034         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1035         if (ret)
1036                 return ERR_PTR(ret);
1037
1038         sh = tl_hba->sh;
1039         tcm_loop_hba_no_cnt++;
1040         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1041                  tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1042         return &tl_hba->tl_hba_wwn;
1043 out:
1044         kfree(tl_hba);
1045         return ERR_PTR(ret);
1046 }
1047
1048 static void tcm_loop_drop_scsi_hba(
1049         struct se_wwn *wwn)
1050 {
1051         struct tcm_loop_hba *tl_hba = container_of(wwn,
1052                                 struct tcm_loop_hba, tl_hba_wwn);
1053
1054         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1055                  tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1056                  tl_hba->sh->host_no);
1057         /*
1058          * Call device_unregister() on the original tl_hba->dev.
1059          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1060          * release *tl_hba;
1061          */
1062         device_unregister(&tl_hba->dev);
1063 }
1064
1065 /* Start items for tcm_loop_cit */
1066 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1067 {
1068         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1069 }
1070
1071 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1072
1073 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1074         &tcm_loop_wwn_attr_version,
1075         NULL,
1076 };
1077
1078 /* End items for tcm_loop_cit */
1079
1080 static const struct target_core_fabric_ops loop_ops = {
1081         .module                         = THIS_MODULE,
1082         .fabric_name                    = "loopback",
1083         .tpg_get_wwn                    = tcm_loop_get_endpoint_wwn,
1084         .tpg_get_tag                    = tcm_loop_get_tag,
1085         .tpg_check_demo_mode            = tcm_loop_check_demo_mode,
1086         .tpg_check_prot_fabric_only     = tcm_loop_check_prot_fabric_only,
1087         .check_stop_free                = tcm_loop_check_stop_free,
1088         .release_cmd                    = tcm_loop_release_cmd,
1089         .sess_get_index                 = tcm_loop_sess_get_index,
1090         .write_pending                  = tcm_loop_write_pending,
1091         .get_cmd_state                  = tcm_loop_get_cmd_state,
1092         .queue_data_in                  = tcm_loop_queue_data_in,
1093         .queue_status                   = tcm_loop_queue_status,
1094         .queue_tm_rsp                   = tcm_loop_queue_tm_rsp,
1095         .aborted_task                   = tcm_loop_aborted_task,
1096         .fabric_make_wwn                = tcm_loop_make_scsi_hba,
1097         .fabric_drop_wwn                = tcm_loop_drop_scsi_hba,
1098         .fabric_make_tpg                = tcm_loop_make_naa_tpg,
1099         .fabric_drop_tpg                = tcm_loop_drop_naa_tpg,
1100         .fabric_post_link               = tcm_loop_port_link,
1101         .fabric_pre_unlink              = tcm_loop_port_unlink,
1102         .tfc_wwn_attrs                  = tcm_loop_wwn_attrs,
1103         .tfc_tpg_base_attrs             = tcm_loop_tpg_attrs,
1104         .tfc_tpg_attrib_attrs           = tcm_loop_tpg_attrib_attrs,
1105 };
1106
1107 static int __init tcm_loop_fabric_init(void)
1108 {
1109         int ret = -ENOMEM;
1110
1111         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1112                                 sizeof(struct tcm_loop_cmd),
1113                                 __alignof__(struct tcm_loop_cmd),
1114                                 0, NULL);
1115         if (!tcm_loop_cmd_cache) {
1116                 pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1117                 goto out;
1118         }
1119
1120         ret = tcm_loop_alloc_core_bus();
1121         if (ret)
1122                 goto out_destroy_cache;
1123
1124         ret = target_register_template(&loop_ops);
1125         if (ret)
1126                 goto out_release_core_bus;
1127
1128         return 0;
1129
1130 out_release_core_bus:
1131         tcm_loop_release_core_bus();
1132 out_destroy_cache:
1133         kmem_cache_destroy(tcm_loop_cmd_cache);
1134 out:
1135         return ret;
1136 }
1137
1138 static void __exit tcm_loop_fabric_exit(void)
1139 {
1140         target_unregister_template(&loop_ops);
1141         tcm_loop_release_core_bus();
1142         kmem_cache_destroy(tcm_loop_cmd_cache);
1143 }
1144
1145 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1146 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1147 MODULE_LICENSE("GPL");
1148 module_init(tcm_loop_fabric_init);
1149 module_exit(tcm_loop_fabric_exit);