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 <[email protected]>
  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 int pseudo_lld_bus_match(struct device *dev,
  87                                 struct device_driver *dev_driver)
  88 {
  89         return 1;
  90 }
  91
  92 static struct bus_type tcm_loop_lld_bus = {
  93         .name                   = "tcm_loop_bus",
  94         .match                  = pseudo_lld_bus_match,
  95         .probe                  = tcm_loop_driver_probe,
  96         .remove                 = tcm_loop_driver_remove,
  97 };
  98
  99 static struct device_driver tcm_loop_driverfs = {
 100         .name                   = "tcm_loop",
 101         .bus                    = &tcm_loop_lld_bus,
 102 };
 103 /*
 104  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 105  */
 106 static struct device *tcm_loop_primary;
 107
 108 static void tcm_loop_target_queue_cmd(struct tcm_loop_cmd *tl_cmd)
 109 {
 110         struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
 111         struct scsi_cmnd *sc = tl_cmd->sc;
 112         struct tcm_loop_nexus *tl_nexus;
 113         struct tcm_loop_hba *tl_hba;
 114         struct tcm_loop_tpg *tl_tpg;
 115         struct scatterlist *sgl_bidi = NULL;
 116         u32 sgl_bidi_count = 0, transfer_length;
 117
 118         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 119         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 120
 121         /*
 122          * Ensure that this tl_tpg reference from the incoming sc->device->id
 123          * has already been configured via tcm_loop_make_naa_tpg().
 124          */
 125         if (!tl_tpg->tl_hba) {
 126                 set_host_byte(sc, DID_NO_CONNECT);
 127                 goto out_done;
 128         }
 129         if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
 130                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 131                 goto out_done;
 132         }
 133         tl_nexus = tl_tpg->tl_nexus;
 134         if (!tl_nexus) {
 135                 scmd_printk(KERN_ERR, sc,
 136                             "TCM_Loop I_T Nexus does not exist\n");
 137                 set_host_byte(sc, DID_ERROR);
 138                 goto out_done;
 139         }
 140
 141         transfer_length = scsi_transfer_length(sc);
 142         if (!scsi_prot_sg_count(sc) &&
 143             scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
 144                 se_cmd->prot_pto = true;
 145                 /*
 146                  * loopback transport doesn't support
 147                  * WRITE_GENERATE, READ_STRIP protection
 148                  * information operations, go ahead unprotected.
 149                  */
 150                 transfer_length = scsi_bufflen(sc);
 151         }
 152
 153         se_cmd->tag = tl_cmd->sc_cmd_tag;
 154         target_init_cmd(se_cmd, tl_nexus->se_sess, &tl_cmd->tl_sense_buf[0],
 155                         tl_cmd->sc->device->lun, transfer_length,
 156                         TCM_SIMPLE_TAG, sc->sc_data_direction, 0);
 157
 158         if (target_submit_prep(se_cmd, sc->cmnd, scsi_sglist(sc),
 159                                scsi_sg_count(sc), sgl_bidi, sgl_bidi_count,
 160                                scsi_prot_sglist(sc), scsi_prot_sg_count(sc),
 161                                GFP_ATOMIC))
 162                 return;
 163
 164         target_queue_submission(se_cmd);
 165         return;
 166
 167 out_done:
 168         scsi_done(sc);
 169 }
 170
 171 /*
 172  * ->queuecommand can be and usually is called from interrupt context, so
 173  * defer the actual submission to a workqueue.
 174  */
 175 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 176 {
 177         struct tcm_loop_cmd *tl_cmd = scsi_cmd_priv(sc);
 178
 179         pr_debug("%s() %d:%d:%d:%llu got CDB: 0x%02x scsi_buf_len: %u\n",
 180                  __func__, sc->device->host->host_no, sc->device->id,
 181                  sc->device->channel, sc->device->lun, sc->cmnd[0],
 182                  scsi_bufflen(sc));
 183
 184         memset(tl_cmd, 0, sizeof(*tl_cmd));
 185         tl_cmd->sc = sc;
 186         tl_cmd->sc_cmd_tag = scsi_cmd_to_rq(sc)->tag;
 187
 188         tcm_loop_target_queue_cmd(tl_cmd);
 189         return 0;
 190 }
 191
 192 /*
 193  * Called from SCSI EH process context to issue a LUN_RESET TMR
 194  * to struct scsi_device
 195  */
 196 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 197                               u64 lun, int task, enum tcm_tmreq_table tmr)
 198 {
 199         struct se_cmd *se_cmd;
 200         struct se_session *se_sess;
 201         struct tcm_loop_nexus *tl_nexus;
 202         struct tcm_loop_cmd *tl_cmd;
 203         int ret = TMR_FUNCTION_FAILED, rc;
 204
 205         /*
 206          * Locate the tl_nexus and se_sess pointers
 207          */
 208         tl_nexus = tl_tpg->tl_nexus;
 209         if (!tl_nexus) {
 210                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 211                 return ret;
 212         }
 213
 214         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 215         if (!tl_cmd)
 216                 return ret;
 217
 218         init_completion(&tl_cmd->tmr_done);
 219
 220         se_cmd = &tl_cmd->tl_se_cmd;
 221         se_sess = tl_tpg->tl_nexus->se_sess;
 222
 223         rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun,
 224                                NULL, tmr, GFP_KERNEL, task,
 225                                TARGET_SCF_ACK_KREF);
 226         if (rc < 0)
 227                 goto release;
 228         wait_for_completion(&tl_cmd->tmr_done);
 229         ret = se_cmd->se_tmr_req->response;
 230         target_put_sess_cmd(se_cmd);
 231
 232 out:
 233         return ret;
 234
 235 release:
 236         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 237         goto out;
 238 }
 239
 240 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 241 {
 242         struct tcm_loop_hba *tl_hba;
 243         struct tcm_loop_tpg *tl_tpg;
 244         int ret;
 245
 246         /*
 247          * Locate the tcm_loop_hba_t pointer
 248          */
 249         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 250         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 251         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 252                                  scsi_cmd_to_rq(sc)->tag, TMR_ABORT_TASK);
 253         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 254 }
 255
 256 /*
 257  * Called from SCSI EH process context to issue a LUN_RESET TMR
 258  * to struct scsi_device
 259  */
 260 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 261 {
 262         struct tcm_loop_hba *tl_hba;
 263         struct tcm_loop_tpg *tl_tpg;
 264         int ret;
 265
 266         /*
 267          * Locate the tcm_loop_hba_t pointer
 268          */
 269         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 270         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 271
 272         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 273                                  0, TMR_LUN_RESET);
 274         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 275 }
 276
 277 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 278 {
 279         struct tcm_loop_hba *tl_hba;
 280         struct tcm_loop_tpg *tl_tpg;
 281
 282         /*
 283          * Locate the tcm_loop_hba_t pointer
 284          */
 285         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 286         if (!tl_hba) {
 287                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 288                 return FAILED;
 289         }
 290         /*
 291          * Locate the tl_tpg pointer from TargetID in sc->device->id
 292          */
 293         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 294         if (tl_tpg) {
 295                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 296                 return SUCCESS;
 297         }
 298         return FAILED;
 299 }
 300
 301 static const struct scsi_host_template tcm_loop_driver_template = {
 302         .show_info              = tcm_loop_show_info,
 303         .proc_name              = "tcm_loopback",
 304         .name                   = "TCM_Loopback",
 305         .queuecommand           = tcm_loop_queuecommand,
 306         .change_queue_depth     = scsi_change_queue_depth,
 307         .eh_abort_handler = tcm_loop_abort_task,
 308         .eh_device_reset_handler = tcm_loop_device_reset,
 309         .eh_target_reset_handler = tcm_loop_target_reset,
 310         .this_id                = -1,
 311         .sg_tablesize           = 256,
 312         .max_sectors            = 0xFFFF,
 313         .dma_boundary           = PAGE_SIZE - 1,
 314         .module                 = THIS_MODULE,
 315         .track_queue_depth      = 1,
 316         .cmd_size               = sizeof(struct tcm_loop_cmd),
 317 };
 318
 319 static int tcm_loop_driver_probe(struct device *dev)
 320 {
 321         struct tcm_loop_hba *tl_hba;
 322         struct Scsi_Host *sh;
 323         int error, host_prot;
 324
 325         tl_hba = to_tcm_loop_hba(dev);
 326
 327         sh = scsi_host_alloc(&tcm_loop_driver_template,
 328                         sizeof(struct tcm_loop_hba));
 329         if (!sh) {
 330                 pr_err("Unable to allocate struct scsi_host\n");
 331                 return -ENODEV;
 332         }
 333         tl_hba->sh = sh;
 334
 335         /*
 336          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 337          */
 338         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 339         /*
 340          * Setup single ID, Channel and LUN for now..
 341          */
 342         sh->max_id = 2;
 343         sh->max_lun = 0;
 344         sh->max_channel = 0;
 345         sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 346         sh->nr_hw_queues = tcm_loop_nr_hw_queues;
 347         sh->can_queue = tcm_loop_can_queue;
 348         sh->cmd_per_lun = tcm_loop_cmd_per_lun;
 349
 350         host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
 351                     SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
 352                     SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
 353
 354         scsi_host_set_prot(sh, host_prot);
 355         scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
 356
 357         error = scsi_add_host(sh, &tl_hba->dev);
 358         if (error) {
 359                 pr_err("%s: scsi_add_host failed\n", __func__);
 360                 scsi_host_put(sh);
 361                 return -ENODEV;
 362         }
 363         return 0;
 364 }
 365
 366 static void tcm_loop_driver_remove(struct device *dev)
 367 {
 368         struct tcm_loop_hba *tl_hba;
 369         struct Scsi_Host *sh;
 370
 371         tl_hba = to_tcm_loop_hba(dev);
 372         sh = tl_hba->sh;
 373
 374         scsi_remove_host(sh);
 375         scsi_host_put(sh);
 376 }
 377
 378 static void tcm_loop_release_adapter(struct device *dev)
 379 {
 380         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 381
 382         kfree(tl_hba);
 383 }
 384
 385 /*
 386  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 387  */
 388 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 389 {
 390         int ret;
 391
 392         tl_hba->dev.bus = &tcm_loop_lld_bus;
 393         tl_hba->dev.parent = tcm_loop_primary;
 394         tl_hba->dev.release = &tcm_loop_release_adapter;
 395         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 396
 397         ret = device_register(&tl_hba->dev);
 398         if (ret) {
 399                 pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
 400                 put_device(&tl_hba->dev);
 401                 return -ENODEV;
 402         }
 403
 404         return 0;
 405 }
 406
 407 /*
 408  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 409  * tcm_loop SCSI bus.
 410  */
 411 static int tcm_loop_alloc_core_bus(void)
 412 {
 413         int ret;
 414
 415         tcm_loop_primary = root_device_register("tcm_loop_0");
 416         if (IS_ERR(tcm_loop_primary)) {
 417                 pr_err("Unable to allocate tcm_loop_primary\n");
 418                 return PTR_ERR(tcm_loop_primary);
 419         }
 420
 421         ret = bus_register(&tcm_loop_lld_bus);
 422         if (ret) {
 423                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 424                 goto dev_unreg;
 425         }
 426
 427         ret = driver_register(&tcm_loop_driverfs);
 428         if (ret) {
 429                 pr_err("driver_register() failed for tcm_loop_driverfs\n");
 430                 goto bus_unreg;
 431         }
 432
 433         pr_debug("Initialized TCM Loop Core Bus\n");
 434         return ret;
 435
 436 bus_unreg:
 437         bus_unregister(&tcm_loop_lld_bus);
 438 dev_unreg:
 439         root_device_unregister(tcm_loop_primary);
 440         return ret;
 441 }
 442
 443 static void tcm_loop_release_core_bus(void)
 444 {
 445         driver_unregister(&tcm_loop_driverfs);
 446         bus_unregister(&tcm_loop_lld_bus);
 447         root_device_unregister(tcm_loop_primary);
 448
 449         pr_debug("Releasing TCM Loop Core BUS\n");
 450 }
 451
 452 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
 453 {
 454         return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 455 }
 456
 457 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 458 {
 459         /*
 460          * Return the passed NAA identifier for the Target Port
 461          */
 462         return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
 463 }
 464
 465 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 466 {
 467         /*
 468          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 469          * to represent the SCSI Target Port.
 470          */
 471         return tl_tpg(se_tpg)->tl_tpgt;
 472 }
 473
 474 /*
 475  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 476  * based upon the incoming fabric dependent SCSI Initiator Port
 477  */
 478 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 479 {
 480         return 1;
 481 }
 482
 483 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
 484 {
 485         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 486                                                    tl_se_tpg);
 487         return tl_tpg->tl_fabric_prot_type;
 488 }
 489
 490 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 491 {
 492         return 1;
 493 }
 494
 495 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 496 {
 497         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 498                         struct tcm_loop_cmd, tl_se_cmd);
 499
 500         return tl_cmd->sc_cmd_state;
 501 }
 502
 503 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 504 {
 505         /*
 506          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 507          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 508          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 509          * format with transport_generic_map_mem_to_cmd().
 510          *
 511          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 512          * object execution queue.
 513          */
 514         target_execute_cmd(se_cmd);
 515         return 0;
 516 }
 517
 518 static int tcm_loop_queue_data_or_status(const char *func,
 519                 struct se_cmd *se_cmd, u8 scsi_status)
 520 {
 521         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 522                                 struct tcm_loop_cmd, tl_se_cmd);
 523         struct scsi_cmnd *sc = tl_cmd->sc;
 524
 525         pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
 526                  func, sc, sc->cmnd[0]);
 527
 528         if (se_cmd->sense_buffer &&
 529            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 530             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 531
 532                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 533                                 SCSI_SENSE_BUFFERSIZE);
 534                 sc->result = SAM_STAT_CHECK_CONDITION;
 535         } else
 536                 sc->result = scsi_status;
 537
 538         set_host_byte(sc, DID_OK);
 539         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 540             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 541                 scsi_set_resid(sc, se_cmd->residual_count);
 542         return 0;
 543 }
 544
 545 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 546 {
 547         return tcm_loop_queue_data_or_status(__func__, se_cmd, SAM_STAT_GOOD);
 548 }
 549
 550 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 551 {
 552         return tcm_loop_queue_data_or_status(__func__,
 553                                              se_cmd, se_cmd->scsi_status);
 554 }
 555
 556 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 557 {
 558         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 559                                 struct tcm_loop_cmd, tl_se_cmd);
 560
 561         /* Wake up tcm_loop_issue_tmr(). */
 562         complete(&tl_cmd->tmr_done);
 563 }
 564
 565 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
 566 {
 567         return;
 568 }
 569
 570 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 571 {
 572         switch (tl_hba->tl_proto_id) {
 573         case SCSI_PROTOCOL_SAS:
 574                 return "SAS";
 575         case SCSI_PROTOCOL_FCP:
 576                 return "FCP";
 577         case SCSI_PROTOCOL_ISCSI:
 578                 return "iSCSI";
 579         default:
 580                 break;
 581         }
 582
 583         return "Unknown";
 584 }
 585
 586 /* Start items for tcm_loop_port_cit */
 587
 588 static int tcm_loop_port_link(
 589         struct se_portal_group *se_tpg,
 590         struct se_lun *lun)
 591 {
 592         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 593                                 struct tcm_loop_tpg, tl_se_tpg);
 594         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 595
 596         atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
 597         /*
 598          * Add Linux/SCSI struct scsi_device by HCTL
 599          */
 600         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 601
 602         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 603         return 0;
 604 }
 605
 606 static void tcm_loop_port_unlink(
 607         struct se_portal_group *se_tpg,
 608         struct se_lun *se_lun)
 609 {
 610         struct scsi_device *sd;
 611         struct tcm_loop_hba *tl_hba;
 612         struct tcm_loop_tpg *tl_tpg;
 613
 614         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 615         tl_hba = tl_tpg->tl_hba;
 616
 617         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 618                                 se_lun->unpacked_lun);
 619         if (!sd) {
 620                 pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
 621                        0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 622                 return;
 623         }
 624         /*
 625          * Remove Linux/SCSI struct scsi_device by HCTL
 626          */
 627         scsi_remove_device(sd);
 628         scsi_device_put(sd);
 629
 630         atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
 631
 632         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 633 }
 634
 635 /* End items for tcm_loop_port_cit */
 636
 637 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
 638                 struct config_item *item, char *page)
 639 {
 640         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 641         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 642                                                    tl_se_tpg);
 643
 644         return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
 645 }
 646
 647 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
 648                 struct config_item *item, const char *page, size_t count)
 649 {
 650         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 651         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 652                                                    tl_se_tpg);
 653         unsigned long val;
 654         int ret = kstrtoul(page, 0, &val);
 655
 656         if (ret) {
 657                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
 658                 return ret;
 659         }
 660         if (val != 0 && val != 1 && val != 3) {
 661                 pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
 662                 return -EINVAL;
 663         }
 664         tl_tpg->tl_fabric_prot_type = val;
 665
 666         return count;
 667 }
 668
 669 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
 670
 671 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
 672         &tcm_loop_tpg_attrib_attr_fabric_prot_type,
 673         NULL,
 674 };
 675
 676 /* Start items for tcm_loop_nexus_cit */
 677
 678 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
 679                                   struct se_session *se_sess, void *p)
 680 {
 681         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 682                                         struct tcm_loop_tpg, tl_se_tpg);
 683
 684         tl_tpg->tl_nexus = p;
 685         return 0;
 686 }
 687
 688 static int tcm_loop_make_nexus(
 689         struct tcm_loop_tpg *tl_tpg,
 690         const char *name)
 691 {
 692         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 693         struct tcm_loop_nexus *tl_nexus;
 694         int ret;
 695
 696         if (tl_tpg->tl_nexus) {
 697                 pr_debug("tl_tpg->tl_nexus already exists\n");
 698                 return -EEXIST;
 699         }
 700
 701         tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
 702         if (!tl_nexus)
 703                 return -ENOMEM;
 704
 705         tl_nexus->se_sess = target_setup_session(&tl_tpg->tl_se_tpg, 0, 0,
 706                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
 707                                         name, tl_nexus, tcm_loop_alloc_sess_cb);
 708         if (IS_ERR(tl_nexus->se_sess)) {
 709                 ret = PTR_ERR(tl_nexus->se_sess);
 710                 kfree(tl_nexus);
 711                 return ret;
 712         }
 713
 714         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
 715                  tcm_loop_dump_proto_id(tl_hba), name);
 716         return 0;
 717 }
 718
 719 static int tcm_loop_drop_nexus(
 720         struct tcm_loop_tpg *tpg)
 721 {
 722         struct se_session *se_sess;
 723         struct tcm_loop_nexus *tl_nexus;
 724
 725         tl_nexus = tpg->tl_nexus;
 726         if (!tl_nexus)
 727                 return -ENODEV;
 728
 729         se_sess = tl_nexus->se_sess;
 730         if (!se_sess)
 731                 return -ENODEV;
 732
 733         if (atomic_read(&tpg->tl_tpg_port_count)) {
 734                 pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
 735                        atomic_read(&tpg->tl_tpg_port_count));
 736                 return -EPERM;
 737         }
 738
 739         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
 740                  tcm_loop_dump_proto_id(tpg->tl_hba),
 741                  tl_nexus->se_sess->se_node_acl->initiatorname);
 742         /*
 743          * Release the SCSI I_T Nexus to the emulated Target Port
 744          */
 745         target_remove_session(se_sess);
 746         tpg->tl_nexus = NULL;
 747         kfree(tl_nexus);
 748         return 0;
 749 }
 750
 751 /* End items for tcm_loop_nexus_cit */
 752
 753 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
 754 {
 755         struct se_portal_group *se_tpg = to_tpg(item);
 756         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 757                         struct tcm_loop_tpg, tl_se_tpg);
 758         struct tcm_loop_nexus *tl_nexus;
 759         ssize_t ret;
 760
 761         tl_nexus = tl_tpg->tl_nexus;
 762         if (!tl_nexus)
 763                 return -ENODEV;
 764
 765         ret = snprintf(page, PAGE_SIZE, "%s\n",
 766                 tl_nexus->se_sess->se_node_acl->initiatorname);
 767
 768         return ret;
 769 }
 770
 771 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
 772                 const char *page, size_t count)
 773 {
 774         struct se_portal_group *se_tpg = to_tpg(item);
 775         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 776                         struct tcm_loop_tpg, tl_se_tpg);
 777         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 778         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
 779         int ret;
 780         /*
 781          * Shutdown the active I_T nexus if 'NULL' is passed..
 782          */
 783         if (!strncmp(page, "NULL", 4)) {
 784                 ret = tcm_loop_drop_nexus(tl_tpg);
 785                 return (!ret) ? count : ret;
 786         }
 787         /*
 788          * Otherwise make sure the passed virtual Initiator port WWN matches
 789          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
 790          * tcm_loop_make_nexus()
 791          */
 792         if (strlen(page) >= TL_WWN_ADDR_LEN) {
 793                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
 794                        page, TL_WWN_ADDR_LEN);
 795                 return -EINVAL;
 796         }
 797         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
 798
 799         ptr = strstr(i_port, "naa.");
 800         if (ptr) {
 801                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
 802                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
 803                                i_port, tcm_loop_dump_proto_id(tl_hba));
 804                         return -EINVAL;
 805                 }
 806                 port_ptr = &i_port[0];
 807                 goto check_newline;
 808         }
 809         ptr = strstr(i_port, "fc.");
 810         if (ptr) {
 811                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
 812                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
 813                                i_port, tcm_loop_dump_proto_id(tl_hba));
 814                         return -EINVAL;
 815                 }
 816                 port_ptr = &i_port[3]; /* Skip over "fc." */
 817                 goto check_newline;
 818         }
 819         ptr = strstr(i_port, "iqn.");
 820         if (ptr) {
 821                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
 822                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
 823                                i_port, tcm_loop_dump_proto_id(tl_hba));
 824                         return -EINVAL;
 825                 }
 826                 port_ptr = &i_port[0];
 827                 goto check_newline;
 828         }
 829         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
 830                i_port);
 831         return -EINVAL;
 832         /*
 833          * Clear any trailing newline for the NAA WWN
 834          */
 835 check_newline:
 836         if (i_port[strlen(i_port)-1] == '\n')
 837                 i_port[strlen(i_port)-1] = '\0';
 838
 839         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
 840         if (ret < 0)
 841                 return ret;
 842
 843         return count;
 844 }
 845
 846 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
 847                 char *page)
 848 {
 849         struct se_portal_group *se_tpg = to_tpg(item);
 850         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 851                         struct tcm_loop_tpg, tl_se_tpg);
 852         const char *status = NULL;
 853         ssize_t ret = -EINVAL;
 854
 855         switch (tl_tpg->tl_transport_status) {
 856         case TCM_TRANSPORT_ONLINE:
 857                 status = "online";
 858                 break;
 859         case TCM_TRANSPORT_OFFLINE:
 860                 status = "offline";
 861                 break;
 862         default:
 863                 break;
 864         }
 865
 866         if (status)
 867                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
 868
 869         return ret;
 870 }
 871
 872 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
 873                 const char *page, size_t count)
 874 {
 875         struct se_portal_group *se_tpg = to_tpg(item);
 876         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 877                         struct tcm_loop_tpg, tl_se_tpg);
 878
 879         if (!strncmp(page, "online", 6)) {
 880                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 881                 return count;
 882         }
 883         if (!strncmp(page, "offline", 7)) {
 884                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
 885                 if (tl_tpg->tl_nexus) {
 886                         struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
 887
 888                         core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
 889                 }
 890                 return count;
 891         }
 892         return -EINVAL;
 893 }
 894
 895 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
 896                                          char *page)
 897 {
 898         struct se_portal_group *se_tpg = to_tpg(item);
 899         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 900                         struct tcm_loop_tpg, tl_se_tpg);
 901         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 902
 903         return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
 904                         tl_hba->sh->host_no, tl_tpg->tl_tpgt);
 905 }
 906
 907 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
 908 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
 909 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
 910
 911 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
 912         &tcm_loop_tpg_attr_nexus,
 913         &tcm_loop_tpg_attr_transport_status,
 914         &tcm_loop_tpg_attr_address,
 915         NULL,
 916 };
 917
 918 /* Start items for tcm_loop_naa_cit */
 919
 920 static struct se_portal_group *tcm_loop_make_naa_tpg(struct se_wwn *wwn,
 921                                                      const char *name)
 922 {
 923         struct tcm_loop_hba *tl_hba = container_of(wwn,
 924                         struct tcm_loop_hba, tl_hba_wwn);
 925         struct tcm_loop_tpg *tl_tpg;
 926         int ret;
 927         unsigned long tpgt;
 928
 929         if (strstr(name, "tpgt_") != name) {
 930                 pr_err("Unable to locate \"tpgt_#\" directory group\n");
 931                 return ERR_PTR(-EINVAL);
 932         }
 933         if (kstrtoul(name+5, 10, &tpgt))
 934                 return ERR_PTR(-EINVAL);
 935
 936         if (tpgt >= TL_TPGS_PER_HBA) {
 937                 pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
 938                        tpgt, TL_TPGS_PER_HBA);
 939                 return ERR_PTR(-EINVAL);
 940         }
 941         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
 942         tl_tpg->tl_hba = tl_hba;
 943         tl_tpg->tl_tpgt = tpgt;
 944         /*
 945          * Register the tl_tpg as a emulated TCM Target Endpoint
 946          */
 947         ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
 948         if (ret < 0)
 949                 return ERR_PTR(-ENOMEM);
 950
 951         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
 952                  tcm_loop_dump_proto_id(tl_hba),
 953                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
 954         return &tl_tpg->tl_se_tpg;
 955 }
 956
 957 static void tcm_loop_drop_naa_tpg(
 958         struct se_portal_group *se_tpg)
 959 {
 960         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
 961         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 962                                 struct tcm_loop_tpg, tl_se_tpg);
 963         struct tcm_loop_hba *tl_hba;
 964         unsigned short tpgt;
 965
 966         tl_hba = tl_tpg->tl_hba;
 967         tpgt = tl_tpg->tl_tpgt;
 968         /*
 969          * Release the I_T Nexus for the Virtual target link if present
 970          */
 971         tcm_loop_drop_nexus(tl_tpg);
 972         /*
 973          * Deregister the tl_tpg as a emulated TCM Target Endpoint
 974          */
 975         core_tpg_deregister(se_tpg);
 976
 977         tl_tpg->tl_hba = NULL;
 978         tl_tpg->tl_tpgt = 0;
 979
 980         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
 981                  tcm_loop_dump_proto_id(tl_hba),
 982                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
 983 }
 984
 985 /* End items for tcm_loop_naa_cit */
 986
 987 /* Start items for tcm_loop_cit */
 988
 989 static struct se_wwn *tcm_loop_make_scsi_hba(
 990         struct target_fabric_configfs *tf,
 991         struct config_group *group,
 992         const char *name)
 993 {
 994         struct tcm_loop_hba *tl_hba;
 995         struct Scsi_Host *sh;
 996         char *ptr;
 997         int ret, off = 0;
 998
 999         tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
1000         if (!tl_hba)
1001                 return ERR_PTR(-ENOMEM);
1002
1003         /*
1004          * Determine the emulated Protocol Identifier and Target Port Name
1005          * based on the incoming configfs directory name.
1006          */
1007         ptr = strstr(name, "naa.");
1008         if (ptr) {
1009                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1010                 goto check_len;
1011         }
1012         ptr = strstr(name, "fc.");
1013         if (ptr) {
1014                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1015                 off = 3; /* Skip over "fc." */
1016                 goto check_len;
1017         }
1018         ptr = strstr(name, "iqn.");
1019         if (!ptr) {
1020                 pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1021                        name);
1022                 ret = -EINVAL;
1023                 goto out;
1024         }
1025         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1026
1027 check_len:
1028         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1029                 pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1030                        name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1031                 ret = -EINVAL;
1032                 goto out;
1033         }
1034         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1035
1036         /*
1037          * Call device_register(tl_hba->dev) to register the emulated
1038          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1039          * device_register() callbacks in tcm_loop_driver_probe()
1040          */
1041         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1042         if (ret)
1043                 return ERR_PTR(ret);
1044
1045         sh = tl_hba->sh;
1046         tcm_loop_hba_no_cnt++;
1047         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1048                  tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1049         return &tl_hba->tl_hba_wwn;
1050 out:
1051         kfree(tl_hba);
1052         return ERR_PTR(ret);
1053 }
1054
1055 static void tcm_loop_drop_scsi_hba(
1056         struct se_wwn *wwn)
1057 {
1058         struct tcm_loop_hba *tl_hba = container_of(wwn,
1059                                 struct tcm_loop_hba, tl_hba_wwn);
1060
1061         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1062                  tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1063                  tl_hba->sh->host_no);
1064         /*
1065          * Call device_unregister() on the original tl_hba->dev.
1066          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1067          * release *tl_hba;
1068          */
1069         device_unregister(&tl_hba->dev);
1070 }
1071
1072 /* Start items for tcm_loop_cit */
1073 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1074 {
1075         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1076 }
1077
1078 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1079
1080 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1081         &tcm_loop_wwn_attr_version,
1082         NULL,
1083 };
1084
1085 /* End items for tcm_loop_cit */
1086
1087 static const struct target_core_fabric_ops loop_ops = {
1088         .module                         = THIS_MODULE,
1089         .fabric_name                    = "loopback",
1090         .tpg_get_wwn                    = tcm_loop_get_endpoint_wwn,
1091         .tpg_get_tag                    = tcm_loop_get_tag,
1092         .tpg_check_demo_mode            = tcm_loop_check_demo_mode,
1093         .tpg_check_prot_fabric_only     = tcm_loop_check_prot_fabric_only,
1094         .check_stop_free                = tcm_loop_check_stop_free,
1095         .release_cmd                    = tcm_loop_release_cmd,
1096         .sess_get_index                 = tcm_loop_sess_get_index,
1097         .write_pending                  = tcm_loop_write_pending,
1098         .get_cmd_state                  = tcm_loop_get_cmd_state,
1099         .queue_data_in                  = tcm_loop_queue_data_in,
1100         .queue_status                   = tcm_loop_queue_status,
1101         .queue_tm_rsp                   = tcm_loop_queue_tm_rsp,
1102         .aborted_task                   = tcm_loop_aborted_task,
1103         .fabric_make_wwn                = tcm_loop_make_scsi_hba,
1104         .fabric_drop_wwn                = tcm_loop_drop_scsi_hba,
1105         .fabric_make_tpg                = tcm_loop_make_naa_tpg,
1106         .fabric_drop_tpg                = tcm_loop_drop_naa_tpg,
1107         .fabric_post_link               = tcm_loop_port_link,
1108         .fabric_pre_unlink              = tcm_loop_port_unlink,
1109         .tfc_wwn_attrs                  = tcm_loop_wwn_attrs,
1110         .tfc_tpg_base_attrs             = tcm_loop_tpg_attrs,
1111         .tfc_tpg_attrib_attrs           = tcm_loop_tpg_attrib_attrs,
1112 };
1113
1114 static int __init tcm_loop_fabric_init(void)
1115 {
1116         int ret = -ENOMEM;
1117
1118         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1119                                 sizeof(struct tcm_loop_cmd),
1120                                 __alignof__(struct tcm_loop_cmd),
1121                                 0, NULL);
1122         if (!tcm_loop_cmd_cache) {
1123                 pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1124                 goto out;
1125         }
1126
1127         ret = tcm_loop_alloc_core_bus();
1128         if (ret)
1129                 goto out_destroy_cache;
1130
1131         ret = target_register_template(&loop_ops);
1132         if (ret)
1133                 goto out_release_core_bus;
1134
1135         return 0;
1136
1137 out_release_core_bus:
1138         tcm_loop_release_core_bus();
1139 out_destroy_cache:
1140         kmem_cache_destroy(tcm_loop_cmd_cache);
1141 out:
1142         return ret;
1143 }
1144
1145 static void __exit tcm_loop_fabric_exit(void)
1146 {
1147         target_unregister_template(&loop_ops);
1148         tcm_loop_release_core_bus();
1149         kmem_cache_destroy(tcm_loop_cmd_cache);
1150 }
1151
1152 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1153 MODULE_AUTHOR("Nicholas A. Bellinger <[email protected]>");
1154 MODULE_LICENSE("GPL");
1155 module_init(tcm_loop_fabric_init);
1156 module_exit(tcm_loop_fabric_exit);