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 RisingTide Systems LLC.
   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_transport.h>
  37 #include <target/target_core_fabric_ops.h>
  38 #include <target/target_core_fabric_configfs.h>
  39 #include <target/target_core_fabric_lib.h>
  40 #include <target/target_core_configfs.h>
  41 #include <target/target_core_device.h>
  42 #include <target/target_core_tpg.h>
  43 #include <target/target_core_tmr.h>
  44
  45 #include "tcm_loop.h"
  46
  47 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  48
  49 /* Local pointer to allocated TCM configfs fabric module */
  50 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
  51
  52 static struct kmem_cache *tcm_loop_cmd_cache;
  53
  54 static int tcm_loop_hba_no_cnt;
  55
  56 /*
  57  * Allocate a tcm_loop cmd descriptor from target_core_mod code
  58  *
  59  * Can be called from interrupt context in tcm_loop_queuecommand() below
  60  */
  61 static struct se_cmd *tcm_loop_allocate_core_cmd(
  62         struct tcm_loop_hba *tl_hba,
  63         struct se_portal_group *se_tpg,
  64         struct scsi_cmnd *sc)
  65 {
  66         struct se_cmd *se_cmd;
  67         struct se_session *se_sess;
  68         struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
  69         struct tcm_loop_cmd *tl_cmd;
  70         int sam_task_attr;
  71
  72         if (!tl_nexus) {
  73                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
  74                                 " does not exist\n");
  75                 set_host_byte(sc, DID_ERROR);
  76                 return NULL;
  77         }
  78         se_sess = tl_nexus->se_sess;
  79
  80         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
  81         if (!tl_cmd) {
  82                 pr_err("Unable to allocate struct tcm_loop_cmd\n");
  83                 set_host_byte(sc, DID_ERROR);
  84                 return NULL;
  85         }
  86         se_cmd = &tl_cmd->tl_se_cmd;
  87         /*
  88          * Save the pointer to struct scsi_cmnd *sc
  89          */
  90         tl_cmd->sc = sc;
  91         /*
  92          * Locate the SAM Task Attr from struct scsi_cmnd *
  93          */
  94         if (sc->device->tagged_supported) {
  95                 switch (sc->tag) {
  96                 case HEAD_OF_QUEUE_TAG:
  97                         sam_task_attr = MSG_HEAD_TAG;
  98                         break;
  99                 case ORDERED_QUEUE_TAG:
 100                         sam_task_attr = MSG_ORDERED_TAG;
 101                         break;
 102                 default:
 103                         sam_task_attr = MSG_SIMPLE_TAG;
 104                         break;
 105                 }
 106         } else
 107                 sam_task_attr = MSG_SIMPLE_TAG;
 108
 109         /*
 110          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 111          */
 112         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
 113                         scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
 114                         &tl_cmd->tl_sense_buf[0]);
 115
 116         if (scsi_bidi_cmnd(sc))
 117                 se_cmd->se_cmd_flags |= SCF_BIDI;
 118
 119         /*
 120          * Locate the struct se_lun pointer and attach it to struct se_cmd
 121          */
 122         if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
 123                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 124                 set_host_byte(sc, DID_NO_CONNECT);
 125                 return NULL;
 126         }
 127
 128         return se_cmd;
 129 }
 130
 131 /*
 132  * Called by struct target_core_fabric_ops->new_cmd_map()
 133  *
 134  * Always called in process context.  A non zero return value
 135  * here will signal to handle an exception based on the return code.
 136  */
 137 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
 138 {
 139         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 140                                 struct tcm_loop_cmd, tl_se_cmd);
 141         struct scsi_cmnd *sc = tl_cmd->sc;
 142         struct scatterlist *sgl_bidi = NULL;
 143         u32 sgl_bidi_count = 0;
 144         int ret;
 145         /*
 146          * Allocate the necessary tasks to complete the received CDB+data
 147          */
 148         ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
 149         if (ret != 0)
 150                 return ret;
 151         /*
 152          * For BIDI commands, pass in the extra READ buffer
 153          * to transport_generic_map_mem_to_cmd() below..
 154          */
 155         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 156                 struct scsi_data_buffer *sdb = scsi_in(sc);
 157
 158                 sgl_bidi = sdb->table.sgl;
 159                 sgl_bidi_count = sdb->table.nents;
 160         }
 161         /*
 162          * Because some userspace code via scsi-generic do not memset their
 163          * associated read buffers, go ahead and do that here for type
 164          * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
 165          * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
 166          * by target core in transport_generic_allocate_tasks() ->
 167          * transport_generic_cmd_sequencer().
 168          */
 169         if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
 170             se_cmd->data_direction == DMA_FROM_DEVICE) {
 171                 struct scatterlist *sg = scsi_sglist(sc);
 172                 unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
 173
 174                 if (buf != NULL) {
 175                         memset(buf, 0, sg->length);
 176                         kunmap(sg_page(sg));
 177                 }
 178         }
 179
 180         /* Tell the core about our preallocated memory */
 181         return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
 182                         scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
 183 }
 184
 185 /*
 186  * Called from struct target_core_fabric_ops->check_stop_free()
 187  */
 188 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 189 {
 190         /*
 191          * Do not release struct se_cmd's containing a valid TMR
 192          * pointer.  These will be released directly in tcm_loop_device_reset()
 193          * with transport_generic_free_cmd().
 194          */
 195         if (se_cmd->se_tmr_req)
 196                 return 0;
 197         /*
 198          * Release the struct se_cmd, which will make a callback to release
 199          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
 200          */
 201         transport_generic_free_cmd(se_cmd, 0);
 202         return 1;
 203 }
 204
 205 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
 206 {
 207         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 208                                 struct tcm_loop_cmd, tl_se_cmd);
 209
 210         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 211 }
 212
 213 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
 214                                 char **start, off_t offset,
 215                                 int length, int inout)
 216 {
 217         return sprintf(buffer, "tcm_loop_proc_info()\n");
 218 }
 219
 220 static int tcm_loop_driver_probe(struct device *);
 221 static int tcm_loop_driver_remove(struct device *);
 222
 223 static int pseudo_lld_bus_match(struct device *dev,
 224                                 struct device_driver *dev_driver)
 225 {
 226         return 1;
 227 }
 228
 229 static struct bus_type tcm_loop_lld_bus = {
 230         .name                   = "tcm_loop_bus",
 231         .match                  = pseudo_lld_bus_match,
 232         .probe                  = tcm_loop_driver_probe,
 233         .remove                 = tcm_loop_driver_remove,
 234 };
 235
 236 static struct device_driver tcm_loop_driverfs = {
 237         .name                   = "tcm_loop",
 238         .bus                    = &tcm_loop_lld_bus,
 239 };
 240 /*
 241  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 242  */
 243 struct device *tcm_loop_primary;
 244
 245 /*
 246  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 247  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 248  */
 249 static int tcm_loop_change_queue_depth(
 250         struct scsi_device *sdev,
 251         int depth,
 252         int reason)
 253 {
 254         switch (reason) {
 255         case SCSI_QDEPTH_DEFAULT:
 256                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 257                 break;
 258         case SCSI_QDEPTH_QFULL:
 259                 scsi_track_queue_full(sdev, depth);
 260                 break;
 261         case SCSI_QDEPTH_RAMP_UP:
 262                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 263                 break;
 264         default:
 265                 return -EOPNOTSUPP;
 266         }
 267         return sdev->queue_depth;
 268 }
 269
 270 /*
 271  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
 272  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
 273  */
 274 static int tcm_loop_queuecommand(
 275         struct Scsi_Host *sh,
 276         struct scsi_cmnd *sc)
 277 {
 278         struct se_cmd *se_cmd;
 279         struct se_portal_group *se_tpg;
 280         struct tcm_loop_hba *tl_hba;
 281         struct tcm_loop_tpg *tl_tpg;
 282
 283         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 284                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 285                 sc->device->id, sc->device->channel, sc->device->lun,
 286                 sc->cmnd[0], scsi_bufflen(sc));
 287         /*
 288          * Locate the tcm_loop_hba_t pointer
 289          */
 290         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 291         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 292         /*
 293          * Ensure that this tl_tpg reference from the incoming sc->device->id
 294          * has already been configured via tcm_loop_make_naa_tpg().
 295          */
 296         if (!tl_tpg->tl_hba) {
 297                 set_host_byte(sc, DID_NO_CONNECT);
 298                 sc->scsi_done(sc);
 299                 return 0;
 300         }
 301         se_tpg = &tl_tpg->tl_se_tpg;
 302         /*
 303          * Determine the SAM Task Attribute and allocate tl_cmd and
 304          * tl_cmd->tl_se_cmd from TCM infrastructure
 305          */
 306         se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
 307         if (!se_cmd) {
 308                 sc->scsi_done(sc);
 309                 return 0;
 310         }
 311         /*
 312          * Queue up the newly allocated to be processed in TCM thread context.
 313         */
 314         transport_generic_handle_cdb_map(se_cmd);
 315         return 0;
 316 }
 317
 318 /*
 319  * Called from SCSI EH process context to issue a LUN_RESET TMR
 320  * to struct scsi_device
 321  */
 322 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 323 {
 324         struct se_cmd *se_cmd = NULL;
 325         struct se_portal_group *se_tpg;
 326         struct se_session *se_sess;
 327         struct tcm_loop_cmd *tl_cmd = NULL;
 328         struct tcm_loop_hba *tl_hba;
 329         struct tcm_loop_nexus *tl_nexus;
 330         struct tcm_loop_tmr *tl_tmr = NULL;
 331         struct tcm_loop_tpg *tl_tpg;
 332         int ret = FAILED;
 333         /*
 334          * Locate the tcm_loop_hba_t pointer
 335          */
 336         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 337         /*
 338          * Locate the tl_nexus and se_sess pointers
 339          */
 340         tl_nexus = tl_hba->tl_nexus;
 341         if (!tl_nexus) {
 342                 pr_err("Unable to perform device reset without"
 343                                 " active I_T Nexus\n");
 344                 return FAILED;
 345         }
 346         se_sess = tl_nexus->se_sess;
 347         /*
 348          * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
 349          */
 350         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 351         se_tpg = &tl_tpg->tl_se_tpg;
 352
 353         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 354         if (!tl_cmd) {
 355                 pr_err("Unable to allocate memory for tl_cmd\n");
 356                 return FAILED;
 357         }
 358
 359         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 360         if (!tl_tmr) {
 361                 pr_err("Unable to allocate memory for tl_tmr\n");
 362                 goto release;
 363         }
 364         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 365
 366         se_cmd = &tl_cmd->tl_se_cmd;
 367         /*
 368          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 369          */
 370         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 371                                 DMA_NONE, MSG_SIMPLE_TAG,
 372                                 &tl_cmd->tl_sense_buf[0]);
 373         /*
 374          * Allocate the LUN_RESET TMR
 375          */
 376         se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
 377                                                 TMR_LUN_RESET, GFP_KERNEL);
 378         if (IS_ERR(se_cmd->se_tmr_req))
 379                 goto release;
 380         /*
 381          * Locate the underlying TCM struct se_lun from sc->device->lun
 382          */
 383         if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
 384                 goto release;
 385         /*
 386          * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
 387          * to wake us up.
 388          */
 389         transport_generic_handle_tmr(se_cmd);
 390         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 391         /*
 392          * The TMR LUN_RESET has completed, check the response status and
 393          * then release allocations.
 394          */
 395         ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 396                 SUCCESS : FAILED;
 397 release:
 398         if (se_cmd)
 399                 transport_generic_free_cmd(se_cmd, 1);
 400         else
 401                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 402         kfree(tl_tmr);
 403         return ret;
 404 }
 405
 406 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 407 {
 408         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 409         return 0;
 410 }
 411
 412 static int tcm_loop_slave_configure(struct scsi_device *sd)
 413 {
 414         return 0;
 415 }
 416
 417 static struct scsi_host_template tcm_loop_driver_template = {
 418         .proc_info              = tcm_loop_proc_info,
 419         .proc_name              = "tcm_loopback",
 420         .name                   = "TCM_Loopback",
 421         .queuecommand           = tcm_loop_queuecommand,
 422         .change_queue_depth     = tcm_loop_change_queue_depth,
 423         .eh_device_reset_handler = tcm_loop_device_reset,
 424         .can_queue              = TL_SCSI_CAN_QUEUE,
 425         .this_id                = -1,
 426         .sg_tablesize           = TL_SCSI_SG_TABLESIZE,
 427         .cmd_per_lun            = TL_SCSI_CMD_PER_LUN,
 428         .max_sectors            = TL_SCSI_MAX_SECTORS,
 429         .use_clustering         = DISABLE_CLUSTERING,
 430         .slave_alloc            = tcm_loop_slave_alloc,
 431         .slave_configure        = tcm_loop_slave_configure,
 432         .module                 = THIS_MODULE,
 433 };
 434
 435 static int tcm_loop_driver_probe(struct device *dev)
 436 {
 437         struct tcm_loop_hba *tl_hba;
 438         struct Scsi_Host *sh;
 439         int error;
 440
 441         tl_hba = to_tcm_loop_hba(dev);
 442
 443         sh = scsi_host_alloc(&tcm_loop_driver_template,
 444                         sizeof(struct tcm_loop_hba));
 445         if (!sh) {
 446                 pr_err("Unable to allocate struct scsi_host\n");
 447                 return -ENODEV;
 448         }
 449         tl_hba->sh = sh;
 450
 451         /*
 452          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 453          */
 454         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 455         /*
 456          * Setup single ID, Channel and LUN for now..
 457          */
 458         sh->max_id = 2;
 459         sh->max_lun = 0;
 460         sh->max_channel = 0;
 461         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 462
 463         error = scsi_add_host(sh, &tl_hba->dev);
 464         if (error) {
 465                 pr_err("%s: scsi_add_host failed\n", __func__);
 466                 scsi_host_put(sh);
 467                 return -ENODEV;
 468         }
 469         return 0;
 470 }
 471
 472 static int tcm_loop_driver_remove(struct device *dev)
 473 {
 474         struct tcm_loop_hba *tl_hba;
 475         struct Scsi_Host *sh;
 476
 477         tl_hba = to_tcm_loop_hba(dev);
 478         sh = tl_hba->sh;
 479
 480         scsi_remove_host(sh);
 481         scsi_host_put(sh);
 482         return 0;
 483 }
 484
 485 static void tcm_loop_release_adapter(struct device *dev)
 486 {
 487         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 488
 489         kfree(tl_hba);
 490 }
 491
 492 /*
 493  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 494  */
 495 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 496 {
 497         int ret;
 498
 499         tl_hba->dev.bus = &tcm_loop_lld_bus;
 500         tl_hba->dev.parent = tcm_loop_primary;
 501         tl_hba->dev.release = &tcm_loop_release_adapter;
 502         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 503
 504         ret = device_register(&tl_hba->dev);
 505         if (ret) {
 506                 pr_err("device_register() failed for"
 507                                 " tl_hba->dev: %d\n", ret);
 508                 return -ENODEV;
 509         }
 510
 511         return 0;
 512 }
 513
 514 /*
 515  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 516  * tcm_loop SCSI bus.
 517  */
 518 static int tcm_loop_alloc_core_bus(void)
 519 {
 520         int ret;
 521
 522         tcm_loop_primary = root_device_register("tcm_loop_0");
 523         if (IS_ERR(tcm_loop_primary)) {
 524                 pr_err("Unable to allocate tcm_loop_primary\n");
 525                 return PTR_ERR(tcm_loop_primary);
 526         }
 527
 528         ret = bus_register(&tcm_loop_lld_bus);
 529         if (ret) {
 530                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 531                 goto dev_unreg;
 532         }
 533
 534         ret = driver_register(&tcm_loop_driverfs);
 535         if (ret) {
 536                 pr_err("driver_register() failed for"
 537                                 "tcm_loop_driverfs\n");
 538                 goto bus_unreg;
 539         }
 540
 541         pr_debug("Initialized TCM Loop Core Bus\n");
 542         return ret;
 543
 544 bus_unreg:
 545         bus_unregister(&tcm_loop_lld_bus);
 546 dev_unreg:
 547         root_device_unregister(tcm_loop_primary);
 548         return ret;
 549 }
 550
 551 static void tcm_loop_release_core_bus(void)
 552 {
 553         driver_unregister(&tcm_loop_driverfs);
 554         bus_unregister(&tcm_loop_lld_bus);
 555         root_device_unregister(tcm_loop_primary);
 556
 557         pr_debug("Releasing TCM Loop Core BUS\n");
 558 }
 559
 560 static char *tcm_loop_get_fabric_name(void)
 561 {
 562         return "loopback";
 563 }
 564
 565 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 566 {
 567         struct tcm_loop_tpg *tl_tpg =
 568                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 569         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 570         /*
 571          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 572          * time based on the protocol dependent prefix of the passed configfs group.
 573          *
 574          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 575          * ProtocolID using target_core_fabric_lib.c symbols.
 576          */
 577         switch (tl_hba->tl_proto_id) {
 578         case SCSI_PROTOCOL_SAS:
 579                 return sas_get_fabric_proto_ident(se_tpg);
 580         case SCSI_PROTOCOL_FCP:
 581                 return fc_get_fabric_proto_ident(se_tpg);
 582         case SCSI_PROTOCOL_ISCSI:
 583                 return iscsi_get_fabric_proto_ident(se_tpg);
 584         default:
 585                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 586                         " SAS emulation\n", tl_hba->tl_proto_id);
 587                 break;
 588         }
 589
 590         return sas_get_fabric_proto_ident(se_tpg);
 591 }
 592
 593 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 594 {
 595         struct tcm_loop_tpg *tl_tpg =
 596                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 597         /*
 598          * Return the passed NAA identifier for the SAS Target Port
 599          */
 600         return &tl_tpg->tl_hba->tl_wwn_address[0];
 601 }
 602
 603 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 604 {
 605         struct tcm_loop_tpg *tl_tpg =
 606                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 607         /*
 608          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 609          * to represent the SCSI Target Port.
 610          */
 611         return tl_tpg->tl_tpgt;
 612 }
 613
 614 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 615 {
 616         return 1;
 617 }
 618
 619 static u32 tcm_loop_get_pr_transport_id(
 620         struct se_portal_group *se_tpg,
 621         struct se_node_acl *se_nacl,
 622         struct t10_pr_registration *pr_reg,
 623         int *format_code,
 624         unsigned char *buf)
 625 {
 626         struct tcm_loop_tpg *tl_tpg =
 627                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 628         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 629
 630         switch (tl_hba->tl_proto_id) {
 631         case SCSI_PROTOCOL_SAS:
 632                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 633                                         format_code, buf);
 634         case SCSI_PROTOCOL_FCP:
 635                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 636                                         format_code, buf);
 637         case SCSI_PROTOCOL_ISCSI:
 638                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 639                                         format_code, buf);
 640         default:
 641                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 642                         " SAS emulation\n", tl_hba->tl_proto_id);
 643                 break;
 644         }
 645
 646         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 647                         format_code, buf);
 648 }
 649
 650 static u32 tcm_loop_get_pr_transport_id_len(
 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 {
 656         struct tcm_loop_tpg *tl_tpg =
 657                         (struct tcm_loop_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_len(se_tpg, se_nacl, pr_reg,
 663                                         format_code);
 664         case SCSI_PROTOCOL_FCP:
 665                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 666                                         format_code);
 667         case SCSI_PROTOCOL_ISCSI:
 668                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 669                                         format_code);
 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_len(se_tpg, se_nacl, pr_reg,
 677                         format_code);
 678 }
 679
 680 /*
 681  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 682  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 683  */
 684 static char *tcm_loop_parse_pr_out_transport_id(
 685         struct se_portal_group *se_tpg,
 686         const char *buf,
 687         u32 *out_tid_len,
 688         char **port_nexus_ptr)
 689 {
 690         struct tcm_loop_tpg *tl_tpg =
 691                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 692         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 693
 694         switch (tl_hba->tl_proto_id) {
 695         case SCSI_PROTOCOL_SAS:
 696                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 697                                         port_nexus_ptr);
 698         case SCSI_PROTOCOL_FCP:
 699                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 700                                         port_nexus_ptr);
 701         case SCSI_PROTOCOL_ISCSI:
 702                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 703                                         port_nexus_ptr);
 704         default:
 705                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 706                         " SAS emulation\n", tl_hba->tl_proto_id);
 707                 break;
 708         }
 709
 710         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 711                         port_nexus_ptr);
 712 }
 713
 714 /*
 715  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 716  * based upon the incoming fabric dependent SCSI Initiator Port
 717  */
 718 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 719 {
 720         return 1;
 721 }
 722
 723 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 724 {
 725         return 0;
 726 }
 727
 728 /*
 729  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 730  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 731  */
 732 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 733 {
 734         return 0;
 735 }
 736
 737 /*
 738  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 739  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 740  * It has been added here as a nop for target_fabric_tf_ops_check()
 741  */
 742 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 743 {
 744         return 0;
 745 }
 746
 747 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 748         struct se_portal_group *se_tpg)
 749 {
 750         struct tcm_loop_nacl *tl_nacl;
 751
 752         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 753         if (!tl_nacl) {
 754                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 755                 return NULL;
 756         }
 757
 758         return &tl_nacl->se_node_acl;
 759 }
 760
 761 static void tcm_loop_tpg_release_fabric_acl(
 762         struct se_portal_group *se_tpg,
 763         struct se_node_acl *se_nacl)
 764 {
 765         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 766                                 struct tcm_loop_nacl, se_node_acl);
 767
 768         kfree(tl_nacl);
 769 }
 770
 771 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 772 {
 773         return 1;
 774 }
 775
 776 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
 777 {
 778         /*
 779          * Assume struct scsi_cmnd is not in remove state..
 780          */
 781         return 0;
 782 }
 783
 784 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
 785 {
 786         /*
 787          * Assume that TL Nexus is always active
 788          */
 789         return 1;
 790 }
 791
 792 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 793 {
 794         return 1;
 795 }
 796
 797 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 798 {
 799         return;
 800 }
 801
 802 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 803 {
 804         return 1;
 805 }
 806
 807 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 808 {
 809         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 810                         struct tcm_loop_cmd, tl_se_cmd);
 811
 812         return tl_cmd->sc_cmd_state;
 813 }
 814
 815 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 816 {
 817         return 0;
 818 }
 819
 820 static void tcm_loop_close_session(struct se_session *se_sess)
 821 {
 822         return;
 823 };
 824
 825 static void tcm_loop_stop_session(
 826         struct se_session *se_sess,
 827         int sess_sleep,
 828         int conn_sleep)
 829 {
 830         return;
 831 }
 832
 833 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
 834 {
 835         return;
 836 }
 837
 838 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 839 {
 840         /*
 841          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 842          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 843          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 844          * format with transport_generic_map_mem_to_cmd().
 845          *
 846          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 847          * object execution queue.
 848          */
 849         transport_generic_process_write(se_cmd);
 850         return 0;
 851 }
 852
 853 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 854 {
 855         return 0;
 856 }
 857
 858 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 859 {
 860         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 861                                 struct tcm_loop_cmd, tl_se_cmd);
 862         struct scsi_cmnd *sc = tl_cmd->sc;
 863
 864         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 865                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 866
 867         sc->result = SAM_STAT_GOOD;
 868         set_host_byte(sc, DID_OK);
 869         sc->scsi_done(sc);
 870         return 0;
 871 }
 872
 873 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 874 {
 875         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 876                                 struct tcm_loop_cmd, tl_se_cmd);
 877         struct scsi_cmnd *sc = tl_cmd->sc;
 878
 879         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 880                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 881
 882         if (se_cmd->sense_buffer &&
 883            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 884             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 885
 886                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 887                                 SCSI_SENSE_BUFFERSIZE);
 888                 sc->result = SAM_STAT_CHECK_CONDITION;
 889                 set_driver_byte(sc, DRIVER_SENSE);
 890         } else
 891                 sc->result = se_cmd->scsi_status;
 892
 893         set_host_byte(sc, DID_OK);
 894         sc->scsi_done(sc);
 895         return 0;
 896 }
 897
 898 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 899 {
 900         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 901         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 902         /*
 903          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 904          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 905          */
 906         atomic_set(&tl_tmr->tmr_complete, 1);
 907         wake_up(&tl_tmr->tl_tmr_wait);
 908         return 0;
 909 }
 910
 911 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
 912 {
 913         return 0;
 914 }
 915
 916 static u16 tcm_loop_get_fabric_sense_len(void)
 917 {
 918         return 0;
 919 }
 920
 921 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 922 {
 923         switch (tl_hba->tl_proto_id) {
 924         case SCSI_PROTOCOL_SAS:
 925                 return "SAS";
 926         case SCSI_PROTOCOL_FCP:
 927                 return "FCP";
 928         case SCSI_PROTOCOL_ISCSI:
 929                 return "iSCSI";
 930         default:
 931                 break;
 932         }
 933
 934         return "Unknown";
 935 }
 936
 937 /* Start items for tcm_loop_port_cit */
 938
 939 static int tcm_loop_port_link(
 940         struct se_portal_group *se_tpg,
 941         struct se_lun *lun)
 942 {
 943         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 944                                 struct tcm_loop_tpg, tl_se_tpg);
 945         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 946
 947         atomic_inc(&tl_tpg->tl_tpg_port_count);
 948         smp_mb__after_atomic_inc();
 949         /*
 950          * Add Linux/SCSI struct scsi_device by HCTL
 951          */
 952         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 953
 954         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 955         return 0;
 956 }
 957
 958 static void tcm_loop_port_unlink(
 959         struct se_portal_group *se_tpg,
 960         struct se_lun *se_lun)
 961 {
 962         struct scsi_device *sd;
 963         struct tcm_loop_hba *tl_hba;
 964         struct tcm_loop_tpg *tl_tpg;
 965
 966         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 967         tl_hba = tl_tpg->tl_hba;
 968
 969         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 970                                 se_lun->unpacked_lun);
 971         if (!sd) {
 972                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 973                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 974                 return;
 975         }
 976         /*
 977          * Remove Linux/SCSI struct scsi_device by HCTL
 978          */
 979         scsi_remove_device(sd);
 980         scsi_device_put(sd);
 981
 982         atomic_dec(&tl_tpg->tl_tpg_port_count);
 983         smp_mb__after_atomic_dec();
 984
 985         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 986 }
 987
 988 /* End items for tcm_loop_port_cit */
 989
 990 /* Start items for tcm_loop_nexus_cit */
 991
 992 static int tcm_loop_make_nexus(
 993         struct tcm_loop_tpg *tl_tpg,
 994         const char *name)
 995 {
 996         struct se_portal_group *se_tpg;
 997         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 998         struct tcm_loop_nexus *tl_nexus;
 999         int ret = -ENOMEM;
1000
1001         if (tl_tpg->tl_hba->tl_nexus) {
1002                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
1003                 return -EEXIST;
1004         }
1005         se_tpg = &tl_tpg->tl_se_tpg;
1006
1007         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1008         if (!tl_nexus) {
1009                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
1010                 return -ENOMEM;
1011         }
1012         /*
1013          * Initialize the struct se_session pointer
1014          */
1015         tl_nexus->se_sess = transport_init_session();
1016         if (IS_ERR(tl_nexus->se_sess)) {
1017                 ret = PTR_ERR(tl_nexus->se_sess);
1018                 goto out;
1019         }
1020         /*
1021          * Since we are running in 'demo mode' this call with generate a
1022          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1023          * Initiator port name of the passed configfs group 'name'.
1024          */
1025         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1026                                 se_tpg, (unsigned char *)name);
1027         if (!tl_nexus->se_sess->se_node_acl) {
1028                 transport_free_session(tl_nexus->se_sess);
1029                 goto out;
1030         }
1031         /*
1032          * Now, register the SAS I_T Nexus as active with the call to
1033          * transport_register_session()
1034          */
1035         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1036                         tl_nexus->se_sess, tl_nexus);
1037         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1038         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1039                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1040                 name);
1041         return 0;
1042
1043 out:
1044         kfree(tl_nexus);
1045         return ret;
1046 }
1047
1048 static int tcm_loop_drop_nexus(
1049         struct tcm_loop_tpg *tpg)
1050 {
1051         struct se_session *se_sess;
1052         struct tcm_loop_nexus *tl_nexus;
1053         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1054
1055         tl_nexus = tpg->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 struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1185         &tcm_loop_tpg_nexus.attr,
1186         NULL,
1187 };
1188
1189 /* Start items for tcm_loop_naa_cit */
1190
1191 struct se_portal_group *tcm_loop_make_naa_tpg(
1192         struct se_wwn *wwn,
1193         struct config_group *group,
1194         const char *name)
1195 {
1196         struct tcm_loop_hba *tl_hba = container_of(wwn,
1197                         struct tcm_loop_hba, tl_hba_wwn);
1198         struct tcm_loop_tpg *tl_tpg;
1199         char *tpgt_str, *end_ptr;
1200         int ret;
1201         unsigned short int tpgt;
1202
1203         tpgt_str = strstr(name, "tpgt_");
1204         if (!tpgt_str) {
1205                 pr_err("Unable to locate \"tpgt_#\" directory"
1206                                 " group\n");
1207                 return ERR_PTR(-EINVAL);
1208         }
1209         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1210         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1211
1212         if (tpgt >= TL_TPGS_PER_HBA) {
1213                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1214                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1215                 return ERR_PTR(-EINVAL);
1216         }
1217         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1218         tl_tpg->tl_hba = tl_hba;
1219         tl_tpg->tl_tpgt = tpgt;
1220         /*
1221          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1222          */
1223         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1224                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1225                         TRANSPORT_TPG_TYPE_NORMAL);
1226         if (ret < 0)
1227                 return ERR_PTR(-ENOMEM);
1228
1229         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1230                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1231                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1232
1233         return &tl_tpg->tl_se_tpg;
1234 }
1235
1236 void tcm_loop_drop_naa_tpg(
1237         struct se_portal_group *se_tpg)
1238 {
1239         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1240         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1241                                 struct tcm_loop_tpg, tl_se_tpg);
1242         struct tcm_loop_hba *tl_hba;
1243         unsigned short tpgt;
1244
1245         tl_hba = tl_tpg->tl_hba;
1246         tpgt = tl_tpg->tl_tpgt;
1247         /*
1248          * Release the I_T Nexus for the Virtual SAS link if present
1249          */
1250         tcm_loop_drop_nexus(tl_tpg);
1251         /*
1252          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1253          */
1254         core_tpg_deregister(se_tpg);
1255
1256         tl_tpg->tl_hba = NULL;
1257         tl_tpg->tl_tpgt = 0;
1258
1259         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1260                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1261                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1262 }
1263
1264 /* End items for tcm_loop_naa_cit */
1265
1266 /* Start items for tcm_loop_cit */
1267
1268 struct se_wwn *tcm_loop_make_scsi_hba(
1269         struct target_fabric_configfs *tf,
1270         struct config_group *group,
1271         const char *name)
1272 {
1273         struct tcm_loop_hba *tl_hba;
1274         struct Scsi_Host *sh;
1275         char *ptr;
1276         int ret, off = 0;
1277
1278         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1279         if (!tl_hba) {
1280                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1281                 return ERR_PTR(-ENOMEM);
1282         }
1283         /*
1284          * Determine the emulated Protocol Identifier and Target Port Name
1285          * based on the incoming configfs directory name.
1286          */
1287         ptr = strstr(name, "naa.");
1288         if (ptr) {
1289                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1290                 goto check_len;
1291         }
1292         ptr = strstr(name, "fc.");
1293         if (ptr) {
1294                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1295                 off = 3; /* Skip over "fc." */
1296                 goto check_len;
1297         }
1298         ptr = strstr(name, "iqn.");
1299         if (!ptr) {
1300                 pr_err("Unable to locate prefix for emulated Target "
1301                                 "Port: %s\n", name);
1302                 ret = -EINVAL;
1303                 goto out;
1304         }
1305         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1306
1307 check_len:
1308         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1309                 pr_err("Emulated NAA %s Address: %s, exceeds"
1310                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1311                         TL_WWN_ADDR_LEN);
1312                 ret = -EINVAL;
1313                 goto out;
1314         }
1315         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1316
1317         /*
1318          * Call device_register(tl_hba->dev) to register the emulated
1319          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1320          * device_register() callbacks in tcm_loop_driver_probe()
1321          */
1322         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1323         if (ret)
1324                 goto out;
1325
1326         sh = tl_hba->sh;
1327         tcm_loop_hba_no_cnt++;
1328         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1329                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1330                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1331
1332         return &tl_hba->tl_hba_wwn;
1333 out:
1334         kfree(tl_hba);
1335         return ERR_PTR(ret);
1336 }
1337
1338 void tcm_loop_drop_scsi_hba(
1339         struct se_wwn *wwn)
1340 {
1341         struct tcm_loop_hba *tl_hba = container_of(wwn,
1342                                 struct tcm_loop_hba, tl_hba_wwn);
1343
1344         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1345                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1346                 tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1347         /*
1348          * Call device_unregister() on the original tl_hba->dev.
1349          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1350          * release *tl_hba;
1351          */
1352         device_unregister(&tl_hba->dev);
1353 }
1354
1355 /* Start items for tcm_loop_cit */
1356 static ssize_t tcm_loop_wwn_show_attr_version(
1357         struct target_fabric_configfs *tf,
1358         char *page)
1359 {
1360         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1361 }
1362
1363 TF_WWN_ATTR_RO(tcm_loop, version);
1364
1365 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1366         &tcm_loop_wwn_version.attr,
1367         NULL,
1368 };
1369
1370 /* End items for tcm_loop_cit */
1371
1372 static int tcm_loop_register_configfs(void)
1373 {
1374         struct target_fabric_configfs *fabric;
1375         struct config_group *tf_cg;
1376         int ret;
1377         /*
1378          * Set the TCM Loop HBA counter to zero
1379          */
1380         tcm_loop_hba_no_cnt = 0;
1381         /*
1382          * Register the top level struct config_item_type with TCM core
1383          */
1384         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1385         if (IS_ERR(fabric)) {
1386                 pr_err("tcm_loop_register_configfs() failed!\n");
1387                 return PTR_ERR(fabric);
1388         }
1389         /*
1390          * Setup the fabric API of function pointers used by target_core_mod
1391          */
1392         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1393         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1394         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1395         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1396         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1397         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1398         fabric->tf_ops.tpg_get_pr_transport_id_len =
1399                                         &tcm_loop_get_pr_transport_id_len;
1400         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1401                                         &tcm_loop_parse_pr_out_transport_id;
1402         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1403         fabric->tf_ops.tpg_check_demo_mode_cache =
1404                                         &tcm_loop_check_demo_mode_cache;
1405         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1406                                         &tcm_loop_check_demo_mode_write_protect;
1407         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1408                                         &tcm_loop_check_prod_mode_write_protect;
1409         /*
1410          * The TCM loopback fabric module runs in demo-mode to a local
1411          * virtual SCSI device, so fabric dependent initator ACLs are
1412          * not required.
1413          */
1414         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1415         fabric->tf_ops.tpg_release_fabric_acl =
1416                                         &tcm_loop_tpg_release_fabric_acl;
1417         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1418         /*
1419          * Used for setting up remaining TCM resources in process context
1420          */
1421         fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1422         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1423         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1424         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1425         fabric->tf_ops.close_session = &tcm_loop_close_session;
1426         fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1427         fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1428         fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1429         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1430         fabric->tf_ops.sess_get_initiator_sid = NULL;
1431         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1432         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1433         /*
1434          * Not used for TCM loopback
1435          */
1436         fabric->tf_ops.set_default_node_attributes =
1437                                         &tcm_loop_set_default_node_attributes;
1438         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1439         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1440         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1441         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1442         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1443         fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1444         fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1445         fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1446
1447         tf_cg = &fabric->tf_group;
1448         /*
1449          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1450          */
1451         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1452         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1453         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1454         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1455         /*
1456          * fabric_post_link() and fabric_pre_unlink() are used for
1457          * registration and release of TCM Loop Virtual SCSI LUNs.
1458          */
1459         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1460         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1461         fabric->tf_ops.fabric_make_np = NULL;
1462         fabric->tf_ops.fabric_drop_np = NULL;
1463         /*
1464          * Setup default attribute lists for various fabric->tf_cit_tmpl
1465          */
1466         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1467         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1468         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1469         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1470         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1471         /*
1472          * Once fabric->tf_ops has been setup, now register the fabric for
1473          * use within TCM
1474          */
1475         ret = target_fabric_configfs_register(fabric);
1476         if (ret < 0) {
1477                 pr_err("target_fabric_configfs_register() for"
1478                                 " TCM_Loop failed!\n");
1479                 target_fabric_configfs_free(fabric);
1480                 return -1;
1481         }
1482         /*
1483          * Setup our local pointer to *fabric.
1484          */
1485         tcm_loop_fabric_configfs = fabric;
1486         pr_debug("TCM_LOOP[0] - Set fabric ->"
1487                         " tcm_loop_fabric_configfs\n");
1488         return 0;
1489 }
1490
1491 static void tcm_loop_deregister_configfs(void)
1492 {
1493         if (!tcm_loop_fabric_configfs)
1494                 return;
1495
1496         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1497         tcm_loop_fabric_configfs = NULL;
1498         pr_debug("TCM_LOOP[0] - Cleared"
1499                                 " tcm_loop_fabric_configfs\n");
1500 }
1501
1502 static int __init tcm_loop_fabric_init(void)
1503 {
1504         int ret;
1505
1506         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1507                                 sizeof(struct tcm_loop_cmd),
1508                                 __alignof__(struct tcm_loop_cmd),
1509                                 0, NULL);
1510         if (!tcm_loop_cmd_cache) {
1511                 pr_debug("kmem_cache_create() for"
1512                         " tcm_loop_cmd_cache failed\n");
1513                 return -ENOMEM;
1514         }
1515
1516         ret = tcm_loop_alloc_core_bus();
1517         if (ret)
1518                 return ret;
1519
1520         ret = tcm_loop_register_configfs();
1521         if (ret) {
1522                 tcm_loop_release_core_bus();
1523                 return ret;
1524         }
1525
1526         return 0;
1527 }
1528
1529 static void __exit tcm_loop_fabric_exit(void)
1530 {
1531         tcm_loop_deregister_configfs();
1532         tcm_loop_release_core_bus();
1533         kmem_cache_destroy(tcm_loop_cmd_cache);
1534 }
1535
1536 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1537 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1538 MODULE_LICENSE("GPL");
1539 module_init(tcm_loop_fabric_init);
1540 module_exit(tcm_loop_fabric_exit);