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 #include <scsi/scsi_tcq.h>
  35
  36 #include <target/target_core_base.h>
  37 #include <target/target_core_transport.h>
  38 #include <target/target_core_fabric_ops.h>
  39 #include <target/target_core_fabric_configfs.h>
  40 #include <target/target_core_fabric_lib.h>
  41 #include <target/target_core_configfs.h>
  42 #include <target/target_core_device.h>
  43 #include <target/target_core_tpg.h>
  44 #include <target/target_core_tmr.h>
  45
  46 #include "tcm_loop.h"
  47
  48 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  49
  50 /* Local pointer to allocated TCM configfs fabric module */
  51 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
  52
  53 static struct kmem_cache *tcm_loop_cmd_cache;
  54
  55 static int tcm_loop_hba_no_cnt;
  56
  57 /*
  58  * Allocate a tcm_loop cmd descriptor from target_core_mod code
  59  *
  60  * Can be called from interrupt context in tcm_loop_queuecommand() below
  61  */
  62 static struct se_cmd *tcm_loop_allocate_core_cmd(
  63         struct tcm_loop_hba *tl_hba,
  64         struct se_portal_group *se_tpg,
  65         struct scsi_cmnd *sc)
  66 {
  67         struct se_cmd *se_cmd;
  68         struct se_session *se_sess;
  69         struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
  70         struct tcm_loop_cmd *tl_cmd;
  71         int sam_task_attr;
  72
  73         if (!tl_nexus) {
  74                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
  75                                 " does not exist\n");
  76                 set_host_byte(sc, DID_ERROR);
  77                 return NULL;
  78         }
  79         se_sess = tl_nexus->se_sess;
  80
  81         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
  82         if (!tl_cmd) {
  83                 printk(KERN_ERR "Unable to allocate struct tcm_loop_cmd\n");
  84                 set_host_byte(sc, DID_ERROR);
  85                 return NULL;
  86         }
  87         se_cmd = &tl_cmd->tl_se_cmd;
  88         /*
  89          * Save the pointer to struct scsi_cmnd *sc
  90          */
  91         tl_cmd->sc = sc;
  92         /*
  93          * Locate the SAM Task Attr from struct scsi_cmnd *
  94          */
  95         if (sc->device->tagged_supported) {
  96                 switch (sc->tag) {
  97                 case HEAD_OF_QUEUE_TAG:
  98                         sam_task_attr = MSG_HEAD_TAG;
  99                         break;
 100                 case ORDERED_QUEUE_TAG:
 101                         sam_task_attr = MSG_ORDERED_TAG;
 102                         break;
 103                 default:
 104                         sam_task_attr = MSG_SIMPLE_TAG;
 105                         break;
 106                 }
 107         } else
 108                 sam_task_attr = MSG_SIMPLE_TAG;
 109
 110         /*
 111          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 112          */
 113         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
 114                         scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
 115                         &tl_cmd->tl_sense_buf[0]);
 116
 117         /*
 118          * Signal BIDI usage with T_TASK(cmd)->t_tasks_bidi
 119          */
 120         if (scsi_bidi_cmnd(sc))
 121                 se_cmd->t_task.t_tasks_bidi = 1;
 122         /*
 123          * Locate the struct se_lun pointer and attach it to struct se_cmd
 124          */
 125         if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
 126                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 127                 set_host_byte(sc, DID_NO_CONNECT);
 128                 return NULL;
 129         }
 130
 131         return se_cmd;
 132 }
 133
 134 /*
 135  * Called by struct target_core_fabric_ops->new_cmd_map()
 136  *
 137  * Always called in process context.  A non zero return value
 138  * here will signal to handle an exception based on the return code.
 139  */
 140 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
 141 {
 142         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 143                                 struct tcm_loop_cmd, tl_se_cmd);
 144         struct scsi_cmnd *sc = tl_cmd->sc;
 145         struct scatterlist *sgl_bidi = NULL;
 146         u32 sgl_bidi_count = 0;
 147         int ret;
 148         /*
 149          * Allocate the necessary tasks to complete the received CDB+data
 150          */
 151         ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
 152         if (ret == -ENOMEM) {
 153                 /* Out of Resources */
 154                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 155         } else if (ret == -EINVAL) {
 156                 /*
 157                  * Handle case for SAM_STAT_RESERVATION_CONFLICT
 158                  */
 159                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 160                         return PYX_TRANSPORT_RESERVATION_CONFLICT;
 161                 /*
 162                  * Otherwise, return SAM_STAT_CHECK_CONDITION and return
 163                  * sense data.
 164                  */
 165                 return PYX_TRANSPORT_USE_SENSE_REASON;
 166         }
 167
 168         /*
 169          * For BIDI commands, pass in the extra READ buffer
 170          * to transport_generic_map_mem_to_cmd() below..
 171          */
 172         if (se_cmd->t_task.t_tasks_bidi) {
 173                 struct scsi_data_buffer *sdb = scsi_in(sc);
 174
 175                 sgl_bidi = sdb->table.sgl;
 176                 sgl_bidi_count = sdb->table.nents;
 177         }
 178
 179         /*
 180          * Map the SG memory into struct se_mem->page linked list using the same
 181          * physical memory at sg->page_link.
 182          */
 183         ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
 184                         scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
 185         if (ret < 0)
 186                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 187
 188         return 0;
 189 }
 190
 191 /*
 192  * Called from struct target_core_fabric_ops->check_stop_free()
 193  */
 194 static void tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 195 {
 196         /*
 197          * Do not release struct se_cmd's containing a valid TMR
 198          * pointer.  These will be released directly in tcm_loop_device_reset()
 199          * with transport_generic_free_cmd().
 200          */
 201         if (se_cmd->se_tmr_req)
 202                 return;
 203         /*
 204          * Release the struct se_cmd, which will make a callback to release
 205          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
 206          */
 207         transport_generic_free_cmd(se_cmd, 0, 1, 0);
 208 }
 209
 210 /*
 211  * Called from struct target_core_fabric_ops->release_cmd_to_pool()
 212  */
 213 static void tcm_loop_deallocate_core_cmd(struct se_cmd *se_cmd)
 214 {
 215         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 216                                 struct tcm_loop_cmd, tl_se_cmd);
 217
 218         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 219 }
 220
 221 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
 222                                 char **start, off_t offset,
 223                                 int length, int inout)
 224 {
 225         return sprintf(buffer, "tcm_loop_proc_info()\n");
 226 }
 227
 228 static int tcm_loop_driver_probe(struct device *);
 229 static int tcm_loop_driver_remove(struct device *);
 230
 231 static int pseudo_lld_bus_match(struct device *dev,
 232                                 struct device_driver *dev_driver)
 233 {
 234         return 1;
 235 }
 236
 237 static struct bus_type tcm_loop_lld_bus = {
 238         .name                   = "tcm_loop_bus",
 239         .match                  = pseudo_lld_bus_match,
 240         .probe                  = tcm_loop_driver_probe,
 241         .remove                 = tcm_loop_driver_remove,
 242 };
 243
 244 static struct device_driver tcm_loop_driverfs = {
 245         .name                   = "tcm_loop",
 246         .bus                    = &tcm_loop_lld_bus,
 247 };
 248 /*
 249  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 250  */
 251 struct device *tcm_loop_primary;
 252
 253 /*
 254  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 255  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 256  */
 257 static int tcm_loop_change_queue_depth(
 258         struct scsi_device *sdev,
 259         int depth,
 260         int reason)
 261 {
 262         switch (reason) {
 263         case SCSI_QDEPTH_DEFAULT:
 264                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 265                 break;
 266         case SCSI_QDEPTH_QFULL:
 267                 scsi_track_queue_full(sdev, depth);
 268                 break;
 269         case SCSI_QDEPTH_RAMP_UP:
 270                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 271                 break;
 272         default:
 273                 return -EOPNOTSUPP;
 274         }
 275         return sdev->queue_depth;
 276 }
 277
 278 /*
 279  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
 280  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
 281  */
 282 static int tcm_loop_queuecommand(
 283         struct Scsi_Host *sh,
 284         struct scsi_cmnd *sc)
 285 {
 286         struct se_cmd *se_cmd;
 287         struct se_portal_group *se_tpg;
 288         struct tcm_loop_hba *tl_hba;
 289         struct tcm_loop_tpg *tl_tpg;
 290
 291         TL_CDB_DEBUG("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 292                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 293                 sc->device->id, sc->device->channel, sc->device->lun,
 294                 sc->cmnd[0], scsi_bufflen(sc));
 295         /*
 296          * Locate the tcm_loop_hba_t pointer
 297          */
 298         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 299         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 300         se_tpg = &tl_tpg->tl_se_tpg;
 301         /*
 302          * Determine the SAM Task Attribute and allocate tl_cmd and
 303          * tl_cmd->tl_se_cmd from TCM infrastructure
 304          */
 305         se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
 306         if (!se_cmd) {
 307                 sc->scsi_done(sc);
 308                 return 0;
 309         }
 310         /*
 311          * Queue up the newly allocated to be processed in TCM thread context.
 312         */
 313         transport_generic_handle_cdb_map(se_cmd);
 314         return 0;
 315 }
 316
 317 /*
 318  * Called from SCSI EH process context to issue a LUN_RESET TMR
 319  * to struct scsi_device
 320  */
 321 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 322 {
 323         struct se_cmd *se_cmd = NULL;
 324         struct se_portal_group *se_tpg;
 325         struct se_session *se_sess;
 326         struct tcm_loop_cmd *tl_cmd = NULL;
 327         struct tcm_loop_hba *tl_hba;
 328         struct tcm_loop_nexus *tl_nexus;
 329         struct tcm_loop_tmr *tl_tmr = NULL;
 330         struct tcm_loop_tpg *tl_tpg;
 331         int ret = FAILED;
 332         /*
 333          * Locate the tcm_loop_hba_t pointer
 334          */
 335         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 336         /*
 337          * Locate the tl_nexus and se_sess pointers
 338          */
 339         tl_nexus = tl_hba->tl_nexus;
 340         if (!tl_nexus) {
 341                 printk(KERN_ERR "Unable to perform device reset without"
 342                                 " active I_T Nexus\n");
 343                 return FAILED;
 344         }
 345         se_sess = tl_nexus->se_sess;
 346         /*
 347          * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
 348          */
 349         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 350         se_tpg = &tl_tpg->tl_se_tpg;
 351
 352         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 353         if (!tl_cmd) {
 354                 printk(KERN_ERR "Unable to allocate memory for tl_cmd\n");
 355                 return FAILED;
 356         }
 357
 358         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 359         if (!tl_tmr) {
 360                 printk(KERN_ERR "Unable to allocate memory for tl_tmr\n");
 361                 goto release;
 362         }
 363         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 364
 365         se_cmd = &tl_cmd->tl_se_cmd;
 366         /*
 367          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 368          */
 369         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 370                                 DMA_NONE, MSG_SIMPLE_TAG,
 371                                 &tl_cmd->tl_sense_buf[0]);
 372         /*
 373          * Allocate the LUN_RESET TMR
 374          */
 375         se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
 376                                 TMR_LUN_RESET);
 377         if (IS_ERR(se_cmd->se_tmr_req))
 378                 goto release;
 379         /*
 380          * Locate the underlying TCM struct se_lun from sc->device->lun
 381          */
 382         if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
 383                 goto release;
 384         /*
 385          * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
 386          * to wake us up.
 387          */
 388         transport_generic_handle_tmr(se_cmd);
 389         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 390         /*
 391          * The TMR LUN_RESET has completed, check the response status and
 392          * then release allocations.
 393          */
 394         ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 395                 SUCCESS : FAILED;
 396 release:
 397         if (se_cmd)
 398                 transport_generic_free_cmd(se_cmd, 1, 1, 0);
 399         else
 400                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 401         kfree(tl_tmr);
 402         return ret;
 403 }
 404
 405 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 406 {
 407         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 408         return 0;
 409 }
 410
 411 static int tcm_loop_slave_configure(struct scsi_device *sd)
 412 {
 413         return 0;
 414 }
 415
 416 static struct scsi_host_template tcm_loop_driver_template = {
 417         .proc_info              = tcm_loop_proc_info,
 418         .proc_name              = "tcm_loopback",
 419         .name                   = "TCM_Loopback",
 420         .queuecommand           = tcm_loop_queuecommand,
 421         .change_queue_depth     = tcm_loop_change_queue_depth,
 422         .eh_device_reset_handler = tcm_loop_device_reset,
 423         .can_queue              = TL_SCSI_CAN_QUEUE,
 424         .this_id                = -1,
 425         .sg_tablesize           = TL_SCSI_SG_TABLESIZE,
 426         .cmd_per_lun            = TL_SCSI_CMD_PER_LUN,
 427         .max_sectors            = TL_SCSI_MAX_SECTORS,
 428         .use_clustering         = DISABLE_CLUSTERING,
 429         .slave_alloc            = tcm_loop_slave_alloc,
 430         .slave_configure        = tcm_loop_slave_configure,
 431         .module                 = THIS_MODULE,
 432 };
 433
 434 static int tcm_loop_driver_probe(struct device *dev)
 435 {
 436         struct tcm_loop_hba *tl_hba;
 437         struct Scsi_Host *sh;
 438         int error;
 439
 440         tl_hba = to_tcm_loop_hba(dev);
 441
 442         sh = scsi_host_alloc(&tcm_loop_driver_template,
 443                         sizeof(struct tcm_loop_hba));
 444         if (!sh) {
 445                 printk(KERN_ERR "Unable to allocate struct scsi_host\n");
 446                 return -ENODEV;
 447         }
 448         tl_hba->sh = sh;
 449
 450         /*
 451          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 452          */
 453         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 454         /*
 455          * Setup single ID, Channel and LUN for now..
 456          */
 457         sh->max_id = 2;
 458         sh->max_lun = 0;
 459         sh->max_channel = 0;
 460         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 461
 462         error = scsi_add_host(sh, &tl_hba->dev);
 463         if (error) {
 464                 printk(KERN_ERR "%s: scsi_add_host failed\n", __func__);
 465                 scsi_host_put(sh);
 466                 return -ENODEV;
 467         }
 468         return 0;
 469 }
 470
 471 static int tcm_loop_driver_remove(struct device *dev)
 472 {
 473         struct tcm_loop_hba *tl_hba;
 474         struct Scsi_Host *sh;
 475
 476         tl_hba = to_tcm_loop_hba(dev);
 477         sh = tl_hba->sh;
 478
 479         scsi_remove_host(sh);
 480         scsi_host_put(sh);
 481         return 0;
 482 }
 483
 484 static void tcm_loop_release_adapter(struct device *dev)
 485 {
 486         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 487
 488         kfree(tl_hba);
 489 }
 490
 491 /*
 492  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 493  */
 494 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 495 {
 496         int ret;
 497
 498         tl_hba->dev.bus = &tcm_loop_lld_bus;
 499         tl_hba->dev.parent = tcm_loop_primary;
 500         tl_hba->dev.release = &tcm_loop_release_adapter;
 501         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 502
 503         ret = device_register(&tl_hba->dev);
 504         if (ret) {
 505                 printk(KERN_ERR "device_register() failed for"
 506                                 " tl_hba->dev: %d\n", ret);
 507                 return -ENODEV;
 508         }
 509
 510         return 0;
 511 }
 512
 513 /*
 514  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 515  * tcm_loop SCSI bus.
 516  */
 517 static int tcm_loop_alloc_core_bus(void)
 518 {
 519         int ret;
 520
 521         tcm_loop_primary = root_device_register("tcm_loop_0");
 522         if (IS_ERR(tcm_loop_primary)) {
 523                 printk(KERN_ERR "Unable to allocate tcm_loop_primary\n");
 524                 return PTR_ERR(tcm_loop_primary);
 525         }
 526
 527         ret = bus_register(&tcm_loop_lld_bus);
 528         if (ret) {
 529                 printk(KERN_ERR "bus_register() failed for tcm_loop_lld_bus\n");
 530                 goto dev_unreg;
 531         }
 532
 533         ret = driver_register(&tcm_loop_driverfs);
 534         if (ret) {
 535                 printk(KERN_ERR "driver_register() failed for"
 536                                 "tcm_loop_driverfs\n");
 537                 goto bus_unreg;
 538         }
 539
 540         printk(KERN_INFO "Initialized TCM Loop Core Bus\n");
 541         return ret;
 542
 543 bus_unreg:
 544         bus_unregister(&tcm_loop_lld_bus);
 545 dev_unreg:
 546         root_device_unregister(tcm_loop_primary);
 547         return ret;
 548 }
 549
 550 static void tcm_loop_release_core_bus(void)
 551 {
 552         driver_unregister(&tcm_loop_driverfs);
 553         bus_unregister(&tcm_loop_lld_bus);
 554         root_device_unregister(tcm_loop_primary);
 555
 556         printk(KERN_INFO "Releasing TCM Loop Core BUS\n");
 557 }
 558
 559 static char *tcm_loop_get_fabric_name(void)
 560 {
 561         return "loopback";
 562 }
 563
 564 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 565 {
 566         struct tcm_loop_tpg *tl_tpg =
 567                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 568         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 569         /*
 570          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 571          * time based on the protocol dependent prefix of the passed configfs group.
 572          *
 573          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 574          * ProtocolID using target_core_fabric_lib.c symbols.
 575          */
 576         switch (tl_hba->tl_proto_id) {
 577         case SCSI_PROTOCOL_SAS:
 578                 return sas_get_fabric_proto_ident(se_tpg);
 579         case SCSI_PROTOCOL_FCP:
 580                 return fc_get_fabric_proto_ident(se_tpg);
 581         case SCSI_PROTOCOL_ISCSI:
 582                 return iscsi_get_fabric_proto_ident(se_tpg);
 583         default:
 584                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 585                         " SAS emulation\n", tl_hba->tl_proto_id);
 586                 break;
 587         }
 588
 589         return sas_get_fabric_proto_ident(se_tpg);
 590 }
 591
 592 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 593 {
 594         struct tcm_loop_tpg *tl_tpg =
 595                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 596         /*
 597          * Return the passed NAA identifier for the SAS Target Port
 598          */
 599         return &tl_tpg->tl_hba->tl_wwn_address[0];
 600 }
 601
 602 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 603 {
 604         struct tcm_loop_tpg *tl_tpg =
 605                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 606         /*
 607          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 608          * to represent the SCSI Target Port.
 609          */
 610         return tl_tpg->tl_tpgt;
 611 }
 612
 613 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 614 {
 615         return 1;
 616 }
 617
 618 static u32 tcm_loop_get_pr_transport_id(
 619         struct se_portal_group *se_tpg,
 620         struct se_node_acl *se_nacl,
 621         struct t10_pr_registration *pr_reg,
 622         int *format_code,
 623         unsigned char *buf)
 624 {
 625         struct tcm_loop_tpg *tl_tpg =
 626                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 627         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 628
 629         switch (tl_hba->tl_proto_id) {
 630         case SCSI_PROTOCOL_SAS:
 631                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 632                                         format_code, buf);
 633         case SCSI_PROTOCOL_FCP:
 634                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 635                                         format_code, buf);
 636         case SCSI_PROTOCOL_ISCSI:
 637                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 638                                         format_code, buf);
 639         default:
 640                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 641                         " SAS emulation\n", tl_hba->tl_proto_id);
 642                 break;
 643         }
 644
 645         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 646                         format_code, buf);
 647 }
 648
 649 static u32 tcm_loop_get_pr_transport_id_len(
 650         struct se_portal_group *se_tpg,
 651         struct se_node_acl *se_nacl,
 652         struct t10_pr_registration *pr_reg,
 653         int *format_code)
 654 {
 655         struct tcm_loop_tpg *tl_tpg =
 656                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 657         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 658
 659         switch (tl_hba->tl_proto_id) {
 660         case SCSI_PROTOCOL_SAS:
 661                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 662                                         format_code);
 663         case SCSI_PROTOCOL_FCP:
 664                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 665                                         format_code);
 666         case SCSI_PROTOCOL_ISCSI:
 667                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 668                                         format_code);
 669         default:
 670                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 671                         " SAS emulation\n", tl_hba->tl_proto_id);
 672                 break;
 673         }
 674
 675         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 676                         format_code);
 677 }
 678
 679 /*
 680  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 681  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 682  */
 683 static char *tcm_loop_parse_pr_out_transport_id(
 684         struct se_portal_group *se_tpg,
 685         const char *buf,
 686         u32 *out_tid_len,
 687         char **port_nexus_ptr)
 688 {
 689         struct tcm_loop_tpg *tl_tpg =
 690                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 691         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 692
 693         switch (tl_hba->tl_proto_id) {
 694         case SCSI_PROTOCOL_SAS:
 695                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 696                                         port_nexus_ptr);
 697         case SCSI_PROTOCOL_FCP:
 698                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 699                                         port_nexus_ptr);
 700         case SCSI_PROTOCOL_ISCSI:
 701                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 702                                         port_nexus_ptr);
 703         default:
 704                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 705                         " SAS emulation\n", tl_hba->tl_proto_id);
 706                 break;
 707         }
 708
 709         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 710                         port_nexus_ptr);
 711 }
 712
 713 /*
 714  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 715  * based upon the incoming fabric dependent SCSI Initiator Port
 716  */
 717 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 718 {
 719         return 1;
 720 }
 721
 722 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 723 {
 724         return 0;
 725 }
 726
 727 /*
 728  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 729  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 730  */
 731 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 732 {
 733         return 0;
 734 }
 735
 736 /*
 737  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 738  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 739  * It has been added here as a nop for target_fabric_tf_ops_check()
 740  */
 741 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 742 {
 743         return 0;
 744 }
 745
 746 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 747         struct se_portal_group *se_tpg)
 748 {
 749         struct tcm_loop_nacl *tl_nacl;
 750
 751         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 752         if (!tl_nacl) {
 753                 printk(KERN_ERR "Unable to allocate struct tcm_loop_nacl\n");
 754                 return NULL;
 755         }
 756
 757         return &tl_nacl->se_node_acl;
 758 }
 759
 760 static void tcm_loop_tpg_release_fabric_acl(
 761         struct se_portal_group *se_tpg,
 762         struct se_node_acl *se_nacl)
 763 {
 764         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 765                                 struct tcm_loop_nacl, se_node_acl);
 766
 767         kfree(tl_nacl);
 768 }
 769
 770 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 771 {
 772         return 1;
 773 }
 774
 775 static void tcm_loop_new_cmd_failure(struct se_cmd *se_cmd)
 776 {
 777         /*
 778          * Since TCM_loop is already passing struct scatterlist data from
 779          * struct scsi_cmnd, no more Linux/SCSI failure dependent state need
 780          * to be handled here.
 781          */
 782         return;
 783 }
 784
 785 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
 786 {
 787         /*
 788          * Assume struct scsi_cmnd is not in remove state..
 789          */
 790         return 0;
 791 }
 792
 793 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
 794 {
 795         /*
 796          * Assume that TL Nexus is always active
 797          */
 798         return 1;
 799 }
 800
 801 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 802 {
 803         return 1;
 804 }
 805
 806 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 807 {
 808         return;
 809 }
 810
 811 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 812 {
 813         return 1;
 814 }
 815
 816 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 817 {
 818         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 819                         struct tcm_loop_cmd, tl_se_cmd);
 820
 821         return tl_cmd->sc_cmd_state;
 822 }
 823
 824 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 825 {
 826         return 0;
 827 }
 828
 829 static void tcm_loop_close_session(struct se_session *se_sess)
 830 {
 831         return;
 832 };
 833
 834 static void tcm_loop_stop_session(
 835         struct se_session *se_sess,
 836         int sess_sleep,
 837         int conn_sleep)
 838 {
 839         return;
 840 }
 841
 842 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
 843 {
 844         return;
 845 }
 846
 847 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 848 {
 849         /*
 850          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 851          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 852          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 853          * format with transport_generic_map_mem_to_cmd().
 854          *
 855          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 856          * object execution queue.
 857          */
 858         transport_generic_process_write(se_cmd);
 859         return 0;
 860 }
 861
 862 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 863 {
 864         return 0;
 865 }
 866
 867 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 868 {
 869         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 870                                 struct tcm_loop_cmd, tl_se_cmd);
 871         struct scsi_cmnd *sc = tl_cmd->sc;
 872
 873         TL_CDB_DEBUG("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 874                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 875
 876         sc->result = SAM_STAT_GOOD;
 877         set_host_byte(sc, DID_OK);
 878         sc->scsi_done(sc);
 879         return 0;
 880 }
 881
 882 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 883 {
 884         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 885                                 struct tcm_loop_cmd, tl_se_cmd);
 886         struct scsi_cmnd *sc = tl_cmd->sc;
 887
 888         TL_CDB_DEBUG("tcm_loop_queue_status() called for scsi_cmnd: %p"
 889                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 890
 891         if (se_cmd->sense_buffer &&
 892            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 893             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 894
 895                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 896                                 SCSI_SENSE_BUFFERSIZE);
 897                 sc->result = SAM_STAT_CHECK_CONDITION;
 898                 set_driver_byte(sc, DRIVER_SENSE);
 899         } else
 900                 sc->result = se_cmd->scsi_status;
 901
 902         set_host_byte(sc, DID_OK);
 903         sc->scsi_done(sc);
 904         return 0;
 905 }
 906
 907 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 908 {
 909         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 910         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 911         /*
 912          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 913          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 914          */
 915         atomic_set(&tl_tmr->tmr_complete, 1);
 916         wake_up(&tl_tmr->tl_tmr_wait);
 917         return 0;
 918 }
 919
 920 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
 921 {
 922         return 0;
 923 }
 924
 925 static u16 tcm_loop_get_fabric_sense_len(void)
 926 {
 927         return 0;
 928 }
 929
 930 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 931 {
 932         switch (tl_hba->tl_proto_id) {
 933         case SCSI_PROTOCOL_SAS:
 934                 return "SAS";
 935         case SCSI_PROTOCOL_FCP:
 936                 return "FCP";
 937         case SCSI_PROTOCOL_ISCSI:
 938                 return "iSCSI";
 939         default:
 940                 break;
 941         }
 942
 943         return "Unknown";
 944 }
 945
 946 /* Start items for tcm_loop_port_cit */
 947
 948 static int tcm_loop_port_link(
 949         struct se_portal_group *se_tpg,
 950         struct se_lun *lun)
 951 {
 952         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 953                                 struct tcm_loop_tpg, tl_se_tpg);
 954         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 955
 956         atomic_inc(&tl_tpg->tl_tpg_port_count);
 957         smp_mb__after_atomic_inc();
 958         /*
 959          * Add Linux/SCSI struct scsi_device by HCTL
 960          */
 961         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 962
 963         printk(KERN_INFO "TCM_Loop_ConfigFS: Port Link Successful\n");
 964         return 0;
 965 }
 966
 967 static void tcm_loop_port_unlink(
 968         struct se_portal_group *se_tpg,
 969         struct se_lun *se_lun)
 970 {
 971         struct scsi_device *sd;
 972         struct tcm_loop_hba *tl_hba;
 973         struct tcm_loop_tpg *tl_tpg;
 974
 975         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 976         tl_hba = tl_tpg->tl_hba;
 977
 978         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 979                                 se_lun->unpacked_lun);
 980         if (!sd) {
 981                 printk(KERN_ERR "Unable to locate struct scsi_device for %d:%d:"
 982                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 983                 return;
 984         }
 985         /*
 986          * Remove Linux/SCSI struct scsi_device by HCTL
 987          */
 988         scsi_remove_device(sd);
 989         scsi_device_put(sd);
 990
 991         atomic_dec(&tl_tpg->tl_tpg_port_count);
 992         smp_mb__after_atomic_dec();
 993
 994         printk(KERN_INFO "TCM_Loop_ConfigFS: Port Unlink Successful\n");
 995 }
 996
 997 /* End items for tcm_loop_port_cit */
 998
 999 /* Start items for tcm_loop_nexus_cit */
1000
1001 static int tcm_loop_make_nexus(
1002         struct tcm_loop_tpg *tl_tpg,
1003         const char *name)
1004 {
1005         struct se_portal_group *se_tpg;
1006         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1007         struct tcm_loop_nexus *tl_nexus;
1008         int ret = -ENOMEM;
1009
1010         if (tl_tpg->tl_hba->tl_nexus) {
1011                 printk(KERN_INFO "tl_tpg->tl_hba->tl_nexus already exists\n");
1012                 return -EEXIST;
1013         }
1014         se_tpg = &tl_tpg->tl_se_tpg;
1015
1016         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1017         if (!tl_nexus) {
1018                 printk(KERN_ERR "Unable to allocate struct tcm_loop_nexus\n");
1019                 return -ENOMEM;
1020         }
1021         /*
1022          * Initialize the struct se_session pointer
1023          */
1024         tl_nexus->se_sess = transport_init_session();
1025         if (IS_ERR(tl_nexus->se_sess)) {
1026                 ret = PTR_ERR(tl_nexus->se_sess);
1027                 goto out;
1028         }
1029         /*
1030          * Since we are running in 'demo mode' this call with generate a
1031          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1032          * Initiator port name of the passed configfs group 'name'.
1033          */
1034         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1035                                 se_tpg, (unsigned char *)name);
1036         if (!tl_nexus->se_sess->se_node_acl) {
1037                 transport_free_session(tl_nexus->se_sess);
1038                 goto out;
1039         }
1040         /*
1041          * Now, register the SAS I_T Nexus as active with the call to
1042          * transport_register_session()
1043          */
1044         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1045                         tl_nexus->se_sess, tl_nexus);
1046         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1047         printk(KERN_INFO "TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1048                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1049                 name);
1050         return 0;
1051
1052 out:
1053         kfree(tl_nexus);
1054         return ret;
1055 }
1056
1057 static int tcm_loop_drop_nexus(
1058         struct tcm_loop_tpg *tpg)
1059 {
1060         struct se_session *se_sess;
1061         struct tcm_loop_nexus *tl_nexus;
1062         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1063
1064         tl_nexus = tpg->tl_hba->tl_nexus;
1065         if (!tl_nexus)
1066                 return -ENODEV;
1067
1068         se_sess = tl_nexus->se_sess;
1069         if (!se_sess)
1070                 return -ENODEV;
1071
1072         if (atomic_read(&tpg->tl_tpg_port_count)) {
1073                 printk(KERN_ERR "Unable to remove TCM_Loop I_T Nexus with"
1074                         " active TPG port count: %d\n",
1075                         atomic_read(&tpg->tl_tpg_port_count));
1076                 return -EPERM;
1077         }
1078
1079         printk(KERN_INFO "TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1080                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1081                 tl_nexus->se_sess->se_node_acl->initiatorname);
1082         /*
1083          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1084          */
1085         transport_deregister_session(tl_nexus->se_sess);
1086         tpg->tl_hba->tl_nexus = NULL;
1087         kfree(tl_nexus);
1088         return 0;
1089 }
1090
1091 /* End items for tcm_loop_nexus_cit */
1092
1093 static ssize_t tcm_loop_tpg_show_nexus(
1094         struct se_portal_group *se_tpg,
1095         char *page)
1096 {
1097         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1098                         struct tcm_loop_tpg, tl_se_tpg);
1099         struct tcm_loop_nexus *tl_nexus;
1100         ssize_t ret;
1101
1102         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1103         if (!tl_nexus)
1104                 return -ENODEV;
1105
1106         ret = snprintf(page, PAGE_SIZE, "%s\n",
1107                 tl_nexus->se_sess->se_node_acl->initiatorname);
1108
1109         return ret;
1110 }
1111
1112 static ssize_t tcm_loop_tpg_store_nexus(
1113         struct se_portal_group *se_tpg,
1114         const char *page,
1115         size_t count)
1116 {
1117         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1118                         struct tcm_loop_tpg, tl_se_tpg);
1119         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1120         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1121         int ret;
1122         /*
1123          * Shutdown the active I_T nexus if 'NULL' is passed..
1124          */
1125         if (!strncmp(page, "NULL", 4)) {
1126                 ret = tcm_loop_drop_nexus(tl_tpg);
1127                 return (!ret) ? count : ret;
1128         }
1129         /*
1130          * Otherwise make sure the passed virtual Initiator port WWN matches
1131          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1132          * tcm_loop_make_nexus()
1133          */
1134         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1135                 printk(KERN_ERR "Emulated NAA Sas Address: %s, exceeds"
1136                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1137                 return -EINVAL;
1138         }
1139         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1140
1141         ptr = strstr(i_port, "naa.");
1142         if (ptr) {
1143                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1144                         printk(KERN_ERR "Passed SAS Initiator Port %s does not"
1145                                 " match target port protoid: %s\n", i_port,
1146                                 tcm_loop_dump_proto_id(tl_hba));
1147                         return -EINVAL;
1148                 }
1149                 port_ptr = &i_port[0];
1150                 goto check_newline;
1151         }
1152         ptr = strstr(i_port, "fc.");
1153         if (ptr) {
1154                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1155                         printk(KERN_ERR "Passed FCP Initiator Port %s does not"
1156                                 " match target port protoid: %s\n", i_port,
1157                                 tcm_loop_dump_proto_id(tl_hba));
1158                         return -EINVAL;
1159                 }
1160                 port_ptr = &i_port[3]; /* Skip over "fc." */
1161                 goto check_newline;
1162         }
1163         ptr = strstr(i_port, "iqn.");
1164         if (ptr) {
1165                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1166                         printk(KERN_ERR "Passed iSCSI Initiator Port %s does not"
1167                                 " match target port protoid: %s\n", i_port,
1168                                 tcm_loop_dump_proto_id(tl_hba));
1169                         return -EINVAL;
1170                 }
1171                 port_ptr = &i_port[0];
1172                 goto check_newline;
1173         }
1174         printk(KERN_ERR "Unable to locate prefix for emulated Initiator Port:"
1175                         " %s\n", i_port);
1176         return -EINVAL;
1177         /*
1178          * Clear any trailing newline for the NAA WWN
1179          */
1180 check_newline:
1181         if (i_port[strlen(i_port)-1] == '\n')
1182                 i_port[strlen(i_port)-1] = '\0';
1183
1184         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1185         if (ret < 0)
1186                 return ret;
1187
1188         return count;
1189 }
1190
1191 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1192
1193 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1194         &tcm_loop_tpg_nexus.attr,
1195         NULL,
1196 };
1197
1198 /* Start items for tcm_loop_naa_cit */
1199
1200 struct se_portal_group *tcm_loop_make_naa_tpg(
1201         struct se_wwn *wwn,
1202         struct config_group *group,
1203         const char *name)
1204 {
1205         struct tcm_loop_hba *tl_hba = container_of(wwn,
1206                         struct tcm_loop_hba, tl_hba_wwn);
1207         struct tcm_loop_tpg *tl_tpg;
1208         char *tpgt_str, *end_ptr;
1209         int ret;
1210         unsigned short int tpgt;
1211
1212         tpgt_str = strstr(name, "tpgt_");
1213         if (!tpgt_str) {
1214                 printk(KERN_ERR "Unable to locate \"tpgt_#\" directory"
1215                                 " group\n");
1216                 return ERR_PTR(-EINVAL);
1217         }
1218         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1219         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1220
1221         if (tpgt > TL_TPGS_PER_HBA) {
1222                 printk(KERN_ERR "Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1223                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1224                 return ERR_PTR(-EINVAL);
1225         }
1226         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1227         tl_tpg->tl_hba = tl_hba;
1228         tl_tpg->tl_tpgt = tpgt;
1229         /*
1230          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1231          */
1232         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1233                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1234                         TRANSPORT_TPG_TYPE_NORMAL);
1235         if (ret < 0)
1236                 return ERR_PTR(-ENOMEM);
1237
1238         printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated Emulated %s"
1239                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1240                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1241
1242         return &tl_tpg->tl_se_tpg;
1243 }
1244
1245 void tcm_loop_drop_naa_tpg(
1246         struct se_portal_group *se_tpg)
1247 {
1248         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1249         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1250                                 struct tcm_loop_tpg, tl_se_tpg);
1251         struct tcm_loop_hba *tl_hba;
1252         unsigned short tpgt;
1253
1254         tl_hba = tl_tpg->tl_hba;
1255         tpgt = tl_tpg->tl_tpgt;
1256         /*
1257          * Release the I_T Nexus for the Virtual SAS link if present
1258          */
1259         tcm_loop_drop_nexus(tl_tpg);
1260         /*
1261          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1262          */
1263         core_tpg_deregister(se_tpg);
1264
1265         printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated Emulated %s"
1266                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1267                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1268 }
1269
1270 /* End items for tcm_loop_naa_cit */
1271
1272 /* Start items for tcm_loop_cit */
1273
1274 struct se_wwn *tcm_loop_make_scsi_hba(
1275         struct target_fabric_configfs *tf,
1276         struct config_group *group,
1277         const char *name)
1278 {
1279         struct tcm_loop_hba *tl_hba;
1280         struct Scsi_Host *sh;
1281         char *ptr;
1282         int ret, off = 0;
1283
1284         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1285         if (!tl_hba) {
1286                 printk(KERN_ERR "Unable to allocate struct tcm_loop_hba\n");
1287                 return ERR_PTR(-ENOMEM);
1288         }
1289         /*
1290          * Determine the emulated Protocol Identifier and Target Port Name
1291          * based on the incoming configfs directory name.
1292          */
1293         ptr = strstr(name, "naa.");
1294         if (ptr) {
1295                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1296                 goto check_len;
1297         }
1298         ptr = strstr(name, "fc.");
1299         if (ptr) {
1300                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1301                 off = 3; /* Skip over "fc." */
1302                 goto check_len;
1303         }
1304         ptr = strstr(name, "iqn.");
1305         if (ptr) {
1306                 tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1307                 goto check_len;
1308         }
1309
1310         printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
1311                         " %s\n", name);
1312         return ERR_PTR(-EINVAL);
1313
1314 check_len:
1315         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1316                 printk(KERN_ERR "Emulated NAA %s Address: %s, exceeds"
1317                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1318                         TL_WWN_ADDR_LEN);
1319                 kfree(tl_hba);
1320                 return ERR_PTR(-EINVAL);
1321         }
1322         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1323
1324         /*
1325          * Call device_register(tl_hba->dev) to register the emulated
1326          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1327          * device_register() callbacks in tcm_loop_driver_probe()
1328          */
1329         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1330         if (ret)
1331                 goto out;
1332
1333         sh = tl_hba->sh;
1334         tcm_loop_hba_no_cnt++;
1335         printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated emulated Target"
1336                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1337                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1338
1339         return &tl_hba->tl_hba_wwn;
1340 out:
1341         kfree(tl_hba);
1342         return ERR_PTR(ret);
1343 }
1344
1345 void tcm_loop_drop_scsi_hba(
1346         struct se_wwn *wwn)
1347 {
1348         struct tcm_loop_hba *tl_hba = container_of(wwn,
1349                                 struct tcm_loop_hba, tl_hba_wwn);
1350         int host_no = tl_hba->sh->host_no;
1351         /*
1352          * Call device_unregister() on the original tl_hba->dev.
1353          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1354          * release *tl_hba;
1355          */
1356         device_unregister(&tl_hba->dev);
1357
1358         printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated emulated Target"
1359                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1360                 config_item_name(&wwn->wwn_group.cg_item), host_no);
1361 }
1362
1363 /* Start items for tcm_loop_cit */
1364 static ssize_t tcm_loop_wwn_show_attr_version(
1365         struct target_fabric_configfs *tf,
1366         char *page)
1367 {
1368         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1369 }
1370
1371 TF_WWN_ATTR_RO(tcm_loop, version);
1372
1373 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1374         &tcm_loop_wwn_version.attr,
1375         NULL,
1376 };
1377
1378 /* End items for tcm_loop_cit */
1379
1380 static int tcm_loop_register_configfs(void)
1381 {
1382         struct target_fabric_configfs *fabric;
1383         struct config_group *tf_cg;
1384         int ret;
1385         /*
1386          * Set the TCM Loop HBA counter to zero
1387          */
1388         tcm_loop_hba_no_cnt = 0;
1389         /*
1390          * Register the top level struct config_item_type with TCM core
1391          */
1392         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1393         if (IS_ERR(fabric)) {
1394                 printk(KERN_ERR "tcm_loop_register_configfs() failed!\n");
1395                 return PTR_ERR(fabric);
1396         }
1397         /*
1398          * Setup the fabric API of function pointers used by target_core_mod
1399          */
1400         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1401         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1402         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1403         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1404         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1405         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1406         fabric->tf_ops.tpg_get_pr_transport_id_len =
1407                                         &tcm_loop_get_pr_transport_id_len;
1408         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1409                                         &tcm_loop_parse_pr_out_transport_id;
1410         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1411         fabric->tf_ops.tpg_check_demo_mode_cache =
1412                                         &tcm_loop_check_demo_mode_cache;
1413         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1414                                         &tcm_loop_check_demo_mode_write_protect;
1415         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1416                                         &tcm_loop_check_prod_mode_write_protect;
1417         /*
1418          * The TCM loopback fabric module runs in demo-mode to a local
1419          * virtual SCSI device, so fabric dependent initator ACLs are
1420          * not required.
1421          */
1422         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1423         fabric->tf_ops.tpg_release_fabric_acl =
1424                                         &tcm_loop_tpg_release_fabric_acl;
1425         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1426         /*
1427          * Since tcm_loop is mapping physical memory from Linux/SCSI
1428          * struct scatterlist arrays for each struct scsi_cmnd I/O,
1429          * we do not need TCM to allocate a iovec array for
1430          * virtual memory address mappings
1431          */
1432         fabric->tf_ops.alloc_cmd_iovecs = NULL;
1433         /*
1434          * Used for setting up remaining TCM resources in process context
1435          */
1436         fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1437         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1438         fabric->tf_ops.release_cmd_to_pool = &tcm_loop_deallocate_core_cmd;
1439         fabric->tf_ops.release_cmd_direct = &tcm_loop_deallocate_core_cmd;
1440         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1441         fabric->tf_ops.close_session = &tcm_loop_close_session;
1442         fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1443         fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1444         fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1445         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1446         fabric->tf_ops.sess_get_initiator_sid = NULL;
1447         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1448         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1449         /*
1450          * Not used for TCM loopback
1451          */
1452         fabric->tf_ops.set_default_node_attributes =
1453                                         &tcm_loop_set_default_node_attributes;
1454         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1455         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1456         fabric->tf_ops.new_cmd_failure = &tcm_loop_new_cmd_failure;
1457         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1458         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1459         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1460         fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1461         fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1462         fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1463
1464         tf_cg = &fabric->tf_group;
1465         /*
1466          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1467          */
1468         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1469         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1470         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1471         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1472         /*
1473          * fabric_post_link() and fabric_pre_unlink() are used for
1474          * registration and release of TCM Loop Virtual SCSI LUNs.
1475          */
1476         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1477         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1478         fabric->tf_ops.fabric_make_np = NULL;
1479         fabric->tf_ops.fabric_drop_np = NULL;
1480         /*
1481          * Setup default attribute lists for various fabric->tf_cit_tmpl
1482          */
1483         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1484         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1485         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1486         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1487         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1488         /*
1489          * Once fabric->tf_ops has been setup, now register the fabric for
1490          * use within TCM
1491          */
1492         ret = target_fabric_configfs_register(fabric);
1493         if (ret < 0) {
1494                 printk(KERN_ERR "target_fabric_configfs_register() for"
1495                                 " TCM_Loop failed!\n");
1496                 target_fabric_configfs_free(fabric);
1497                 return -1;
1498         }
1499         /*
1500          * Setup our local pointer to *fabric.
1501          */
1502         tcm_loop_fabric_configfs = fabric;
1503         printk(KERN_INFO "TCM_LOOP[0] - Set fabric ->"
1504                         " tcm_loop_fabric_configfs\n");
1505         return 0;
1506 }
1507
1508 static void tcm_loop_deregister_configfs(void)
1509 {
1510         if (!tcm_loop_fabric_configfs)
1511                 return;
1512
1513         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1514         tcm_loop_fabric_configfs = NULL;
1515         printk(KERN_INFO "TCM_LOOP[0] - Cleared"
1516                                 " tcm_loop_fabric_configfs\n");
1517 }
1518
1519 static int __init tcm_loop_fabric_init(void)
1520 {
1521         int ret;
1522
1523         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1524                                 sizeof(struct tcm_loop_cmd),
1525                                 __alignof__(struct tcm_loop_cmd),
1526                                 0, NULL);
1527         if (!tcm_loop_cmd_cache) {
1528                 printk(KERN_ERR "kmem_cache_create() for"
1529                         " tcm_loop_cmd_cache failed\n");
1530                 return -ENOMEM;
1531         }
1532
1533         ret = tcm_loop_alloc_core_bus();
1534         if (ret)
1535                 return ret;
1536
1537         ret = tcm_loop_register_configfs();
1538         if (ret) {
1539                 tcm_loop_release_core_bus();
1540                 return ret;
1541         }
1542
1543         return 0;
1544 }
1545
1546 static void __exit tcm_loop_fabric_exit(void)
1547 {
1548         tcm_loop_deregister_configfs();
1549         tcm_loop_release_core_bus();
1550         kmem_cache_destroy(tcm_loop_cmd_cache);
1551 }
1552
1553 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1554 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1555 MODULE_LICENSE("GPL");
1556 module_init(tcm_loop_fabric_init);
1557 module_exit(tcm_loop_fabric_exit);