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         /*
 117          * Signal BIDI usage with T_TASK(cmd)->t_tasks_bidi
 118          */
 119         if (scsi_bidi_cmnd(sc))
 120                 se_cmd->t_tasks_bidi = 1;
 121         /*
 122          * Locate the struct se_lun pointer and attach it to struct se_cmd
 123          */
 124         if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
 125                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 126                 set_host_byte(sc, DID_NO_CONNECT);
 127                 return NULL;
 128         }
 129
 130         return se_cmd;
 131 }
 132
 133 /*
 134  * Called by struct target_core_fabric_ops->new_cmd_map()
 135  *
 136  * Always called in process context.  A non zero return value
 137  * here will signal to handle an exception based on the return code.
 138  */
 139 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
 140 {
 141         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 142                                 struct tcm_loop_cmd, tl_se_cmd);
 143         struct scsi_cmnd *sc = tl_cmd->sc;
 144         struct scatterlist *sgl_bidi = NULL;
 145         u32 sgl_bidi_count = 0;
 146         int ret;
 147         /*
 148          * Allocate the necessary tasks to complete the received CDB+data
 149          */
 150         ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
 151         if (ret == -ENOMEM) {
 152                 /* Out of Resources */
 153                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 154         } else if (ret == -EINVAL) {
 155                 /*
 156                  * Handle case for SAM_STAT_RESERVATION_CONFLICT
 157                  */
 158                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 159                         return PYX_TRANSPORT_RESERVATION_CONFLICT;
 160                 /*
 161                  * Otherwise, return SAM_STAT_CHECK_CONDITION and return
 162                  * sense data.
 163                  */
 164                 return PYX_TRANSPORT_USE_SENSE_REASON;
 165         }
 166
 167         /*
 168          * For BIDI commands, pass in the extra READ buffer
 169          * to transport_generic_map_mem_to_cmd() below..
 170          */
 171         if (se_cmd->t_tasks_bidi) {
 172                 struct scsi_data_buffer *sdb = scsi_in(sc);
 173
 174                 sgl_bidi = sdb->table.sgl;
 175                 sgl_bidi_count = sdb->table.nents;
 176         }
 177         /*
 178          * Because some userspace code via scsi-generic do not memset their
 179          * associated read buffers, go ahead and do that here for type
 180          * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
 181          * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
 182          * by target core in transport_generic_allocate_tasks() ->
 183          * transport_generic_cmd_sequencer().
 184          */
 185         if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
 186             se_cmd->data_direction == DMA_FROM_DEVICE) {
 187                 struct scatterlist *sg = scsi_sglist(sc);
 188                 unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
 189
 190                 if (buf != NULL) {
 191                         memset(buf, 0, sg->length);
 192                         kunmap(sg_page(sg));
 193                 }
 194         }
 195
 196         /* Tell the core about our preallocated memory */
 197         ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
 198                         scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
 199         if (ret < 0)
 200                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 201
 202         return 0;
 203 }
 204
 205 /*
 206  * Called from struct target_core_fabric_ops->check_stop_free()
 207  */
 208 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 209 {
 210         /*
 211          * Do not release struct se_cmd's containing a valid TMR
 212          * pointer.  These will be released directly in tcm_loop_device_reset()
 213          * with transport_generic_free_cmd().
 214          */
 215         if (se_cmd->se_tmr_req)
 216                 return 0;
 217         /*
 218          * Release the struct se_cmd, which will make a callback to release
 219          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
 220          */
 221         transport_generic_free_cmd(se_cmd, 0);
 222         return 1;
 223 }
 224
 225 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
 226 {
 227         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 228                                 struct tcm_loop_cmd, tl_se_cmd);
 229
 230         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 231 }
 232
 233 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
 234                                 char **start, off_t offset,
 235                                 int length, int inout)
 236 {
 237         return sprintf(buffer, "tcm_loop_proc_info()\n");
 238 }
 239
 240 static int tcm_loop_driver_probe(struct device *);
 241 static int tcm_loop_driver_remove(struct device *);
 242
 243 static int pseudo_lld_bus_match(struct device *dev,
 244                                 struct device_driver *dev_driver)
 245 {
 246         return 1;
 247 }
 248
 249 static struct bus_type tcm_loop_lld_bus = {
 250         .name                   = "tcm_loop_bus",
 251         .match                  = pseudo_lld_bus_match,
 252         .probe                  = tcm_loop_driver_probe,
 253         .remove                 = tcm_loop_driver_remove,
 254 };
 255
 256 static struct device_driver tcm_loop_driverfs = {
 257         .name                   = "tcm_loop",
 258         .bus                    = &tcm_loop_lld_bus,
 259 };
 260 /*
 261  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 262  */
 263 struct device *tcm_loop_primary;
 264
 265 /*
 266  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 267  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 268  */
 269 static int tcm_loop_change_queue_depth(
 270         struct scsi_device *sdev,
 271         int depth,
 272         int reason)
 273 {
 274         switch (reason) {
 275         case SCSI_QDEPTH_DEFAULT:
 276                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 277                 break;
 278         case SCSI_QDEPTH_QFULL:
 279                 scsi_track_queue_full(sdev, depth);
 280                 break;
 281         case SCSI_QDEPTH_RAMP_UP:
 282                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 283                 break;
 284         default:
 285                 return -EOPNOTSUPP;
 286         }
 287         return sdev->queue_depth;
 288 }
 289
 290 /*
 291  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
 292  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
 293  */
 294 static int tcm_loop_queuecommand(
 295         struct Scsi_Host *sh,
 296         struct scsi_cmnd *sc)
 297 {
 298         struct se_cmd *se_cmd;
 299         struct se_portal_group *se_tpg;
 300         struct tcm_loop_hba *tl_hba;
 301         struct tcm_loop_tpg *tl_tpg;
 302
 303         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 304                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 305                 sc->device->id, sc->device->channel, sc->device->lun,
 306                 sc->cmnd[0], scsi_bufflen(sc));
 307         /*
 308          * Locate the tcm_loop_hba_t pointer
 309          */
 310         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 311         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 312         /*
 313          * Ensure that this tl_tpg reference from the incoming sc->device->id
 314          * has already been configured via tcm_loop_make_naa_tpg().
 315          */
 316         if (!tl_tpg->tl_hba) {
 317                 set_host_byte(sc, DID_NO_CONNECT);
 318                 sc->scsi_done(sc);
 319                 return 0;
 320         }
 321         se_tpg = &tl_tpg->tl_se_tpg;
 322         /*
 323          * Determine the SAM Task Attribute and allocate tl_cmd and
 324          * tl_cmd->tl_se_cmd from TCM infrastructure
 325          */
 326         se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
 327         if (!se_cmd) {
 328                 sc->scsi_done(sc);
 329                 return 0;
 330         }
 331         /*
 332          * Queue up the newly allocated to be processed in TCM thread context.
 333         */
 334         transport_generic_handle_cdb_map(se_cmd);
 335         return 0;
 336 }
 337
 338 /*
 339  * Called from SCSI EH process context to issue a LUN_RESET TMR
 340  * to struct scsi_device
 341  */
 342 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 343 {
 344         struct se_cmd *se_cmd = NULL;
 345         struct se_portal_group *se_tpg;
 346         struct se_session *se_sess;
 347         struct tcm_loop_cmd *tl_cmd = NULL;
 348         struct tcm_loop_hba *tl_hba;
 349         struct tcm_loop_nexus *tl_nexus;
 350         struct tcm_loop_tmr *tl_tmr = NULL;
 351         struct tcm_loop_tpg *tl_tpg;
 352         int ret = FAILED;
 353         /*
 354          * Locate the tcm_loop_hba_t pointer
 355          */
 356         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 357         /*
 358          * Locate the tl_nexus and se_sess pointers
 359          */
 360         tl_nexus = tl_hba->tl_nexus;
 361         if (!tl_nexus) {
 362                 pr_err("Unable to perform device reset without"
 363                                 " active I_T Nexus\n");
 364                 return FAILED;
 365         }
 366         se_sess = tl_nexus->se_sess;
 367         /*
 368          * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
 369          */
 370         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 371         se_tpg = &tl_tpg->tl_se_tpg;
 372
 373         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 374         if (!tl_cmd) {
 375                 pr_err("Unable to allocate memory for tl_cmd\n");
 376                 return FAILED;
 377         }
 378
 379         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 380         if (!tl_tmr) {
 381                 pr_err("Unable to allocate memory for tl_tmr\n");
 382                 goto release;
 383         }
 384         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 385
 386         se_cmd = &tl_cmd->tl_se_cmd;
 387         /*
 388          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 389          */
 390         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 391                                 DMA_NONE, MSG_SIMPLE_TAG,
 392                                 &tl_cmd->tl_sense_buf[0]);
 393         /*
 394          * Allocate the LUN_RESET TMR
 395          */
 396         se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
 397                                                 TMR_LUN_RESET, GFP_KERNEL);
 398         if (IS_ERR(se_cmd->se_tmr_req))
 399                 goto release;
 400         /*
 401          * Locate the underlying TCM struct se_lun from sc->device->lun
 402          */
 403         if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
 404                 goto release;
 405         /*
 406          * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
 407          * to wake us up.
 408          */
 409         transport_generic_handle_tmr(se_cmd);
 410         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 411         /*
 412          * The TMR LUN_RESET has completed, check the response status and
 413          * then release allocations.
 414          */
 415         ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 416                 SUCCESS : FAILED;
 417 release:
 418         if (se_cmd)
 419                 transport_generic_free_cmd(se_cmd, 1);
 420         else
 421                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 422         kfree(tl_tmr);
 423         return ret;
 424 }
 425
 426 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 427 {
 428         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 429         return 0;
 430 }
 431
 432 static int tcm_loop_slave_configure(struct scsi_device *sd)
 433 {
 434         return 0;
 435 }
 436
 437 static struct scsi_host_template tcm_loop_driver_template = {
 438         .proc_info              = tcm_loop_proc_info,
 439         .proc_name              = "tcm_loopback",
 440         .name                   = "TCM_Loopback",
 441         .queuecommand           = tcm_loop_queuecommand,
 442         .change_queue_depth     = tcm_loop_change_queue_depth,
 443         .eh_device_reset_handler = tcm_loop_device_reset,
 444         .can_queue              = TL_SCSI_CAN_QUEUE,
 445         .this_id                = -1,
 446         .sg_tablesize           = TL_SCSI_SG_TABLESIZE,
 447         .cmd_per_lun            = TL_SCSI_CMD_PER_LUN,
 448         .max_sectors            = TL_SCSI_MAX_SECTORS,
 449         .use_clustering         = DISABLE_CLUSTERING,
 450         .slave_alloc            = tcm_loop_slave_alloc,
 451         .slave_configure        = tcm_loop_slave_configure,
 452         .module                 = THIS_MODULE,
 453 };
 454
 455 static int tcm_loop_driver_probe(struct device *dev)
 456 {
 457         struct tcm_loop_hba *tl_hba;
 458         struct Scsi_Host *sh;
 459         int error;
 460
 461         tl_hba = to_tcm_loop_hba(dev);
 462
 463         sh = scsi_host_alloc(&tcm_loop_driver_template,
 464                         sizeof(struct tcm_loop_hba));
 465         if (!sh) {
 466                 pr_err("Unable to allocate struct scsi_host\n");
 467                 return -ENODEV;
 468         }
 469         tl_hba->sh = sh;
 470
 471         /*
 472          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 473          */
 474         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 475         /*
 476          * Setup single ID, Channel and LUN for now..
 477          */
 478         sh->max_id = 2;
 479         sh->max_lun = 0;
 480         sh->max_channel = 0;
 481         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 482
 483         error = scsi_add_host(sh, &tl_hba->dev);
 484         if (error) {
 485                 pr_err("%s: scsi_add_host failed\n", __func__);
 486                 scsi_host_put(sh);
 487                 return -ENODEV;
 488         }
 489         return 0;
 490 }
 491
 492 static int tcm_loop_driver_remove(struct device *dev)
 493 {
 494         struct tcm_loop_hba *tl_hba;
 495         struct Scsi_Host *sh;
 496
 497         tl_hba = to_tcm_loop_hba(dev);
 498         sh = tl_hba->sh;
 499
 500         scsi_remove_host(sh);
 501         scsi_host_put(sh);
 502         return 0;
 503 }
 504
 505 static void tcm_loop_release_adapter(struct device *dev)
 506 {
 507         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 508
 509         kfree(tl_hba);
 510 }
 511
 512 /*
 513  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 514  */
 515 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 516 {
 517         int ret;
 518
 519         tl_hba->dev.bus = &tcm_loop_lld_bus;
 520         tl_hba->dev.parent = tcm_loop_primary;
 521         tl_hba->dev.release = &tcm_loop_release_adapter;
 522         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 523
 524         ret = device_register(&tl_hba->dev);
 525         if (ret) {
 526                 pr_err("device_register() failed for"
 527                                 " tl_hba->dev: %d\n", ret);
 528                 return -ENODEV;
 529         }
 530
 531         return 0;
 532 }
 533
 534 /*
 535  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 536  * tcm_loop SCSI bus.
 537  */
 538 static int tcm_loop_alloc_core_bus(void)
 539 {
 540         int ret;
 541
 542         tcm_loop_primary = root_device_register("tcm_loop_0");
 543         if (IS_ERR(tcm_loop_primary)) {
 544                 pr_err("Unable to allocate tcm_loop_primary\n");
 545                 return PTR_ERR(tcm_loop_primary);
 546         }
 547
 548         ret = bus_register(&tcm_loop_lld_bus);
 549         if (ret) {
 550                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 551                 goto dev_unreg;
 552         }
 553
 554         ret = driver_register(&tcm_loop_driverfs);
 555         if (ret) {
 556                 pr_err("driver_register() failed for"
 557                                 "tcm_loop_driverfs\n");
 558                 goto bus_unreg;
 559         }
 560
 561         pr_debug("Initialized TCM Loop Core Bus\n");
 562         return ret;
 563
 564 bus_unreg:
 565         bus_unregister(&tcm_loop_lld_bus);
 566 dev_unreg:
 567         root_device_unregister(tcm_loop_primary);
 568         return ret;
 569 }
 570
 571 static void tcm_loop_release_core_bus(void)
 572 {
 573         driver_unregister(&tcm_loop_driverfs);
 574         bus_unregister(&tcm_loop_lld_bus);
 575         root_device_unregister(tcm_loop_primary);
 576
 577         pr_debug("Releasing TCM Loop Core BUS\n");
 578 }
 579
 580 static char *tcm_loop_get_fabric_name(void)
 581 {
 582         return "loopback";
 583 }
 584
 585 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 586 {
 587         struct tcm_loop_tpg *tl_tpg =
 588                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 589         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 590         /*
 591          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 592          * time based on the protocol dependent prefix of the passed configfs group.
 593          *
 594          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 595          * ProtocolID using target_core_fabric_lib.c symbols.
 596          */
 597         switch (tl_hba->tl_proto_id) {
 598         case SCSI_PROTOCOL_SAS:
 599                 return sas_get_fabric_proto_ident(se_tpg);
 600         case SCSI_PROTOCOL_FCP:
 601                 return fc_get_fabric_proto_ident(se_tpg);
 602         case SCSI_PROTOCOL_ISCSI:
 603                 return iscsi_get_fabric_proto_ident(se_tpg);
 604         default:
 605                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 606                         " SAS emulation\n", tl_hba->tl_proto_id);
 607                 break;
 608         }
 609
 610         return sas_get_fabric_proto_ident(se_tpg);
 611 }
 612
 613 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 614 {
 615         struct tcm_loop_tpg *tl_tpg =
 616                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 617         /*
 618          * Return the passed NAA identifier for the SAS Target Port
 619          */
 620         return &tl_tpg->tl_hba->tl_wwn_address[0];
 621 }
 622
 623 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 624 {
 625         struct tcm_loop_tpg *tl_tpg =
 626                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 627         /*
 628          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 629          * to represent the SCSI Target Port.
 630          */
 631         return tl_tpg->tl_tpgt;
 632 }
 633
 634 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 635 {
 636         return 1;
 637 }
 638
 639 static u32 tcm_loop_get_pr_transport_id(
 640         struct se_portal_group *se_tpg,
 641         struct se_node_acl *se_nacl,
 642         struct t10_pr_registration *pr_reg,
 643         int *format_code,
 644         unsigned char *buf)
 645 {
 646         struct tcm_loop_tpg *tl_tpg =
 647                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 648         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 649
 650         switch (tl_hba->tl_proto_id) {
 651         case SCSI_PROTOCOL_SAS:
 652                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 653                                         format_code, buf);
 654         case SCSI_PROTOCOL_FCP:
 655                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 656                                         format_code, buf);
 657         case SCSI_PROTOCOL_ISCSI:
 658                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 659                                         format_code, buf);
 660         default:
 661                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 662                         " SAS emulation\n", tl_hba->tl_proto_id);
 663                 break;
 664         }
 665
 666         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 667                         format_code, buf);
 668 }
 669
 670 static u32 tcm_loop_get_pr_transport_id_len(
 671         struct se_portal_group *se_tpg,
 672         struct se_node_acl *se_nacl,
 673         struct t10_pr_registration *pr_reg,
 674         int *format_code)
 675 {
 676         struct tcm_loop_tpg *tl_tpg =
 677                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 678         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 679
 680         switch (tl_hba->tl_proto_id) {
 681         case SCSI_PROTOCOL_SAS:
 682                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 683                                         format_code);
 684         case SCSI_PROTOCOL_FCP:
 685                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 686                                         format_code);
 687         case SCSI_PROTOCOL_ISCSI:
 688                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 689                                         format_code);
 690         default:
 691                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 692                         " SAS emulation\n", tl_hba->tl_proto_id);
 693                 break;
 694         }
 695
 696         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 697                         format_code);
 698 }
 699
 700 /*
 701  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 702  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 703  */
 704 static char *tcm_loop_parse_pr_out_transport_id(
 705         struct se_portal_group *se_tpg,
 706         const char *buf,
 707         u32 *out_tid_len,
 708         char **port_nexus_ptr)
 709 {
 710         struct tcm_loop_tpg *tl_tpg =
 711                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 712         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 713
 714         switch (tl_hba->tl_proto_id) {
 715         case SCSI_PROTOCOL_SAS:
 716                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 717                                         port_nexus_ptr);
 718         case SCSI_PROTOCOL_FCP:
 719                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 720                                         port_nexus_ptr);
 721         case SCSI_PROTOCOL_ISCSI:
 722                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 723                                         port_nexus_ptr);
 724         default:
 725                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 726                         " SAS emulation\n", tl_hba->tl_proto_id);
 727                 break;
 728         }
 729
 730         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 731                         port_nexus_ptr);
 732 }
 733
 734 /*
 735  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 736  * based upon the incoming fabric dependent SCSI Initiator Port
 737  */
 738 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 739 {
 740         return 1;
 741 }
 742
 743 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 744 {
 745         return 0;
 746 }
 747
 748 /*
 749  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 750  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 751  */
 752 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 753 {
 754         return 0;
 755 }
 756
 757 /*
 758  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 759  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 760  * It has been added here as a nop for target_fabric_tf_ops_check()
 761  */
 762 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 763 {
 764         return 0;
 765 }
 766
 767 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 768         struct se_portal_group *se_tpg)
 769 {
 770         struct tcm_loop_nacl *tl_nacl;
 771
 772         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 773         if (!tl_nacl) {
 774                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 775                 return NULL;
 776         }
 777
 778         return &tl_nacl->se_node_acl;
 779 }
 780
 781 static void tcm_loop_tpg_release_fabric_acl(
 782         struct se_portal_group *se_tpg,
 783         struct se_node_acl *se_nacl)
 784 {
 785         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 786                                 struct tcm_loop_nacl, se_node_acl);
 787
 788         kfree(tl_nacl);
 789 }
 790
 791 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 792 {
 793         return 1;
 794 }
 795
 796 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
 797 {
 798         /*
 799          * Assume struct scsi_cmnd is not in remove state..
 800          */
 801         return 0;
 802 }
 803
 804 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
 805 {
 806         /*
 807          * Assume that TL Nexus is always active
 808          */
 809         return 1;
 810 }
 811
 812 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 813 {
 814         return 1;
 815 }
 816
 817 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 818 {
 819         return;
 820 }
 821
 822 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 823 {
 824         return 1;
 825 }
 826
 827 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 828 {
 829         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 830                         struct tcm_loop_cmd, tl_se_cmd);
 831
 832         return tl_cmd->sc_cmd_state;
 833 }
 834
 835 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 836 {
 837         return 0;
 838 }
 839
 840 static void tcm_loop_close_session(struct se_session *se_sess)
 841 {
 842         return;
 843 };
 844
 845 static void tcm_loop_stop_session(
 846         struct se_session *se_sess,
 847         int sess_sleep,
 848         int conn_sleep)
 849 {
 850         return;
 851 }
 852
 853 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
 854 {
 855         return;
 856 }
 857
 858 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 859 {
 860         /*
 861          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 862          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 863          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 864          * format with transport_generic_map_mem_to_cmd().
 865          *
 866          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 867          * object execution queue.
 868          */
 869         transport_generic_process_write(se_cmd);
 870         return 0;
 871 }
 872
 873 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 874 {
 875         return 0;
 876 }
 877
 878 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 879 {
 880         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 881                                 struct tcm_loop_cmd, tl_se_cmd);
 882         struct scsi_cmnd *sc = tl_cmd->sc;
 883
 884         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 885                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 886
 887         sc->result = SAM_STAT_GOOD;
 888         set_host_byte(sc, DID_OK);
 889         sc->scsi_done(sc);
 890         return 0;
 891 }
 892
 893 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 894 {
 895         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 896                                 struct tcm_loop_cmd, tl_se_cmd);
 897         struct scsi_cmnd *sc = tl_cmd->sc;
 898
 899         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 900                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 901
 902         if (se_cmd->sense_buffer &&
 903            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 904             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 905
 906                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 907                                 SCSI_SENSE_BUFFERSIZE);
 908                 sc->result = SAM_STAT_CHECK_CONDITION;
 909                 set_driver_byte(sc, DRIVER_SENSE);
 910         } else
 911                 sc->result = se_cmd->scsi_status;
 912
 913         set_host_byte(sc, DID_OK);
 914         sc->scsi_done(sc);
 915         return 0;
 916 }
 917
 918 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 919 {
 920         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 921         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 922         /*
 923          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 924          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 925          */
 926         atomic_set(&tl_tmr->tmr_complete, 1);
 927         wake_up(&tl_tmr->tl_tmr_wait);
 928         return 0;
 929 }
 930
 931 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
 932 {
 933         return 0;
 934 }
 935
 936 static u16 tcm_loop_get_fabric_sense_len(void)
 937 {
 938         return 0;
 939 }
 940
 941 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 942 {
 943         switch (tl_hba->tl_proto_id) {
 944         case SCSI_PROTOCOL_SAS:
 945                 return "SAS";
 946         case SCSI_PROTOCOL_FCP:
 947                 return "FCP";
 948         case SCSI_PROTOCOL_ISCSI:
 949                 return "iSCSI";
 950         default:
 951                 break;
 952         }
 953
 954         return "Unknown";
 955 }
 956
 957 /* Start items for tcm_loop_port_cit */
 958
 959 static int tcm_loop_port_link(
 960         struct se_portal_group *se_tpg,
 961         struct se_lun *lun)
 962 {
 963         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 964                                 struct tcm_loop_tpg, tl_se_tpg);
 965         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 966
 967         atomic_inc(&tl_tpg->tl_tpg_port_count);
 968         smp_mb__after_atomic_inc();
 969         /*
 970          * Add Linux/SCSI struct scsi_device by HCTL
 971          */
 972         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 973
 974         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 975         return 0;
 976 }
 977
 978 static void tcm_loop_port_unlink(
 979         struct se_portal_group *se_tpg,
 980         struct se_lun *se_lun)
 981 {
 982         struct scsi_device *sd;
 983         struct tcm_loop_hba *tl_hba;
 984         struct tcm_loop_tpg *tl_tpg;
 985
 986         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 987         tl_hba = tl_tpg->tl_hba;
 988
 989         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 990                                 se_lun->unpacked_lun);
 991         if (!sd) {
 992                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 993                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 994                 return;
 995         }
 996         /*
 997          * Remove Linux/SCSI struct scsi_device by HCTL
 998          */
 999         scsi_remove_device(sd);
1000         scsi_device_put(sd);
1001
1002         atomic_dec(&tl_tpg->tl_tpg_port_count);
1003         smp_mb__after_atomic_dec();
1004
1005         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
1006 }
1007
1008 /* End items for tcm_loop_port_cit */
1009
1010 /* Start items for tcm_loop_nexus_cit */
1011
1012 static int tcm_loop_make_nexus(
1013         struct tcm_loop_tpg *tl_tpg,
1014         const char *name)
1015 {
1016         struct se_portal_group *se_tpg;
1017         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1018         struct tcm_loop_nexus *tl_nexus;
1019         int ret = -ENOMEM;
1020
1021         if (tl_tpg->tl_hba->tl_nexus) {
1022                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
1023                 return -EEXIST;
1024         }
1025         se_tpg = &tl_tpg->tl_se_tpg;
1026
1027         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1028         if (!tl_nexus) {
1029                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
1030                 return -ENOMEM;
1031         }
1032         /*
1033          * Initialize the struct se_session pointer
1034          */
1035         tl_nexus->se_sess = transport_init_session();
1036         if (IS_ERR(tl_nexus->se_sess)) {
1037                 ret = PTR_ERR(tl_nexus->se_sess);
1038                 goto out;
1039         }
1040         /*
1041          * Since we are running in 'demo mode' this call with generate a
1042          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1043          * Initiator port name of the passed configfs group 'name'.
1044          */
1045         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1046                                 se_tpg, (unsigned char *)name);
1047         if (!tl_nexus->se_sess->se_node_acl) {
1048                 transport_free_session(tl_nexus->se_sess);
1049                 goto out;
1050         }
1051         /*
1052          * Now, register the SAS I_T Nexus as active with the call to
1053          * transport_register_session()
1054          */
1055         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1056                         tl_nexus->se_sess, tl_nexus);
1057         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1058         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1059                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1060                 name);
1061         return 0;
1062
1063 out:
1064         kfree(tl_nexus);
1065         return ret;
1066 }
1067
1068 static int tcm_loop_drop_nexus(
1069         struct tcm_loop_tpg *tpg)
1070 {
1071         struct se_session *se_sess;
1072         struct tcm_loop_nexus *tl_nexus;
1073         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1074
1075         tl_nexus = tpg->tl_hba->tl_nexus;
1076         if (!tl_nexus)
1077                 return -ENODEV;
1078
1079         se_sess = tl_nexus->se_sess;
1080         if (!se_sess)
1081                 return -ENODEV;
1082
1083         if (atomic_read(&tpg->tl_tpg_port_count)) {
1084                 pr_err("Unable to remove TCM_Loop I_T Nexus with"
1085                         " active TPG port count: %d\n",
1086                         atomic_read(&tpg->tl_tpg_port_count));
1087                 return -EPERM;
1088         }
1089
1090         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1091                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1092                 tl_nexus->se_sess->se_node_acl->initiatorname);
1093         /*
1094          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1095          */
1096         transport_deregister_session(tl_nexus->se_sess);
1097         tpg->tl_hba->tl_nexus = NULL;
1098         kfree(tl_nexus);
1099         return 0;
1100 }
1101
1102 /* End items for tcm_loop_nexus_cit */
1103
1104 static ssize_t tcm_loop_tpg_show_nexus(
1105         struct se_portal_group *se_tpg,
1106         char *page)
1107 {
1108         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1109                         struct tcm_loop_tpg, tl_se_tpg);
1110         struct tcm_loop_nexus *tl_nexus;
1111         ssize_t ret;
1112
1113         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1114         if (!tl_nexus)
1115                 return -ENODEV;
1116
1117         ret = snprintf(page, PAGE_SIZE, "%s\n",
1118                 tl_nexus->se_sess->se_node_acl->initiatorname);
1119
1120         return ret;
1121 }
1122
1123 static ssize_t tcm_loop_tpg_store_nexus(
1124         struct se_portal_group *se_tpg,
1125         const char *page,
1126         size_t count)
1127 {
1128         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1129                         struct tcm_loop_tpg, tl_se_tpg);
1130         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1131         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1132         int ret;
1133         /*
1134          * Shutdown the active I_T nexus if 'NULL' is passed..
1135          */
1136         if (!strncmp(page, "NULL", 4)) {
1137                 ret = tcm_loop_drop_nexus(tl_tpg);
1138                 return (!ret) ? count : ret;
1139         }
1140         /*
1141          * Otherwise make sure the passed virtual Initiator port WWN matches
1142          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1143          * tcm_loop_make_nexus()
1144          */
1145         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1146                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1147                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1148                 return -EINVAL;
1149         }
1150         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1151
1152         ptr = strstr(i_port, "naa.");
1153         if (ptr) {
1154                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1155                         pr_err("Passed SAS 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[0];
1161                 goto check_newline;
1162         }
1163         ptr = strstr(i_port, "fc.");
1164         if (ptr) {
1165                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1166                         pr_err("Passed FCP 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[3]; /* Skip over "fc." */
1172                 goto check_newline;
1173         }
1174         ptr = strstr(i_port, "iqn.");
1175         if (ptr) {
1176                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1177                         pr_err("Passed iSCSI Initiator Port %s does not"
1178                                 " match target port protoid: %s\n", i_port,
1179                                 tcm_loop_dump_proto_id(tl_hba));
1180                         return -EINVAL;
1181                 }
1182                 port_ptr = &i_port[0];
1183                 goto check_newline;
1184         }
1185         pr_err("Unable to locate prefix for emulated Initiator Port:"
1186                         " %s\n", i_port);
1187         return -EINVAL;
1188         /*
1189          * Clear any trailing newline for the NAA WWN
1190          */
1191 check_newline:
1192         if (i_port[strlen(i_port)-1] == '\n')
1193                 i_port[strlen(i_port)-1] = '\0';
1194
1195         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1196         if (ret < 0)
1197                 return ret;
1198
1199         return count;
1200 }
1201
1202 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1203
1204 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1205         &tcm_loop_tpg_nexus.attr,
1206         NULL,
1207 };
1208
1209 /* Start items for tcm_loop_naa_cit */
1210
1211 struct se_portal_group *tcm_loop_make_naa_tpg(
1212         struct se_wwn *wwn,
1213         struct config_group *group,
1214         const char *name)
1215 {
1216         struct tcm_loop_hba *tl_hba = container_of(wwn,
1217                         struct tcm_loop_hba, tl_hba_wwn);
1218         struct tcm_loop_tpg *tl_tpg;
1219         char *tpgt_str, *end_ptr;
1220         int ret;
1221         unsigned short int tpgt;
1222
1223         tpgt_str = strstr(name, "tpgt_");
1224         if (!tpgt_str) {
1225                 pr_err("Unable to locate \"tpgt_#\" directory"
1226                                 " group\n");
1227                 return ERR_PTR(-EINVAL);
1228         }
1229         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1230         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1231
1232         if (tpgt >= TL_TPGS_PER_HBA) {
1233                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1234                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1235                 return ERR_PTR(-EINVAL);
1236         }
1237         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1238         tl_tpg->tl_hba = tl_hba;
1239         tl_tpg->tl_tpgt = tpgt;
1240         /*
1241          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1242          */
1243         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1244                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1245                         TRANSPORT_TPG_TYPE_NORMAL);
1246         if (ret < 0)
1247                 return ERR_PTR(-ENOMEM);
1248
1249         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1250                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1251                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1252
1253         return &tl_tpg->tl_se_tpg;
1254 }
1255
1256 void tcm_loop_drop_naa_tpg(
1257         struct se_portal_group *se_tpg)
1258 {
1259         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1260         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1261                                 struct tcm_loop_tpg, tl_se_tpg);
1262         struct tcm_loop_hba *tl_hba;
1263         unsigned short tpgt;
1264
1265         tl_hba = tl_tpg->tl_hba;
1266         tpgt = tl_tpg->tl_tpgt;
1267         /*
1268          * Release the I_T Nexus for the Virtual SAS link if present
1269          */
1270         tcm_loop_drop_nexus(tl_tpg);
1271         /*
1272          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1273          */
1274         core_tpg_deregister(se_tpg);
1275
1276         tl_tpg->tl_hba = NULL;
1277         tl_tpg->tl_tpgt = 0;
1278
1279         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1280                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1281                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1282 }
1283
1284 /* End items for tcm_loop_naa_cit */
1285
1286 /* Start items for tcm_loop_cit */
1287
1288 struct se_wwn *tcm_loop_make_scsi_hba(
1289         struct target_fabric_configfs *tf,
1290         struct config_group *group,
1291         const char *name)
1292 {
1293         struct tcm_loop_hba *tl_hba;
1294         struct Scsi_Host *sh;
1295         char *ptr;
1296         int ret, off = 0;
1297
1298         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1299         if (!tl_hba) {
1300                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1301                 return ERR_PTR(-ENOMEM);
1302         }
1303         /*
1304          * Determine the emulated Protocol Identifier and Target Port Name
1305          * based on the incoming configfs directory name.
1306          */
1307         ptr = strstr(name, "naa.");
1308         if (ptr) {
1309                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1310                 goto check_len;
1311         }
1312         ptr = strstr(name, "fc.");
1313         if (ptr) {
1314                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1315                 off = 3; /* Skip over "fc." */
1316                 goto check_len;
1317         }
1318         ptr = strstr(name, "iqn.");
1319         if (!ptr) {
1320                 pr_err("Unable to locate prefix for emulated Target "
1321                                 "Port: %s\n", name);
1322                 ret = -EINVAL;
1323                 goto out;
1324         }
1325         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1326
1327 check_len:
1328         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1329                 pr_err("Emulated NAA %s Address: %s, exceeds"
1330                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1331                         TL_WWN_ADDR_LEN);
1332                 ret = -EINVAL;
1333                 goto out;
1334         }
1335         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1336
1337         /*
1338          * Call device_register(tl_hba->dev) to register the emulated
1339          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1340          * device_register() callbacks in tcm_loop_driver_probe()
1341          */
1342         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1343         if (ret)
1344                 goto out;
1345
1346         sh = tl_hba->sh;
1347         tcm_loop_hba_no_cnt++;
1348         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1349                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1350                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1351
1352         return &tl_hba->tl_hba_wwn;
1353 out:
1354         kfree(tl_hba);
1355         return ERR_PTR(ret);
1356 }
1357
1358 void tcm_loop_drop_scsi_hba(
1359         struct se_wwn *wwn)
1360 {
1361         struct tcm_loop_hba *tl_hba = container_of(wwn,
1362                                 struct tcm_loop_hba, tl_hba_wwn);
1363         int host_no = tl_hba->sh->host_no;
1364         /*
1365          * Call device_unregister() on the original tl_hba->dev.
1366          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1367          * release *tl_hba;
1368          */
1369         device_unregister(&tl_hba->dev);
1370
1371         pr_debug("TCM_Loop_ConfigFS: Deallocated emulated Target"
1372                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1373                 config_item_name(&wwn->wwn_group.cg_item), host_no);
1374 }
1375
1376 /* Start items for tcm_loop_cit */
1377 static ssize_t tcm_loop_wwn_show_attr_version(
1378         struct target_fabric_configfs *tf,
1379         char *page)
1380 {
1381         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1382 }
1383
1384 TF_WWN_ATTR_RO(tcm_loop, version);
1385
1386 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1387         &tcm_loop_wwn_version.attr,
1388         NULL,
1389 };
1390
1391 /* End items for tcm_loop_cit */
1392
1393 static int tcm_loop_register_configfs(void)
1394 {
1395         struct target_fabric_configfs *fabric;
1396         struct config_group *tf_cg;
1397         int ret;
1398         /*
1399          * Set the TCM Loop HBA counter to zero
1400          */
1401         tcm_loop_hba_no_cnt = 0;
1402         /*
1403          * Register the top level struct config_item_type with TCM core
1404          */
1405         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1406         if (IS_ERR(fabric)) {
1407                 pr_err("tcm_loop_register_configfs() failed!\n");
1408                 return PTR_ERR(fabric);
1409         }
1410         /*
1411          * Setup the fabric API of function pointers used by target_core_mod
1412          */
1413         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1414         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1415         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1416         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1417         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1418         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1419         fabric->tf_ops.tpg_get_pr_transport_id_len =
1420                                         &tcm_loop_get_pr_transport_id_len;
1421         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1422                                         &tcm_loop_parse_pr_out_transport_id;
1423         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1424         fabric->tf_ops.tpg_check_demo_mode_cache =
1425                                         &tcm_loop_check_demo_mode_cache;
1426         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1427                                         &tcm_loop_check_demo_mode_write_protect;
1428         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1429                                         &tcm_loop_check_prod_mode_write_protect;
1430         /*
1431          * The TCM loopback fabric module runs in demo-mode to a local
1432          * virtual SCSI device, so fabric dependent initator ACLs are
1433          * not required.
1434          */
1435         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1436         fabric->tf_ops.tpg_release_fabric_acl =
1437                                         &tcm_loop_tpg_release_fabric_acl;
1438         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1439         /*
1440          * Used for setting up remaining TCM resources in process context
1441          */
1442         fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1443         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1444         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1445         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1446         fabric->tf_ops.close_session = &tcm_loop_close_session;
1447         fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1448         fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1449         fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1450         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1451         fabric->tf_ops.sess_get_initiator_sid = NULL;
1452         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1453         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1454         /*
1455          * Not used for TCM loopback
1456          */
1457         fabric->tf_ops.set_default_node_attributes =
1458                                         &tcm_loop_set_default_node_attributes;
1459         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1460         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1461         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1462         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1463         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1464         fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1465         fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1466         fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1467
1468         tf_cg = &fabric->tf_group;
1469         /*
1470          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1471          */
1472         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1473         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1474         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1475         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1476         /*
1477          * fabric_post_link() and fabric_pre_unlink() are used for
1478          * registration and release of TCM Loop Virtual SCSI LUNs.
1479          */
1480         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1481         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1482         fabric->tf_ops.fabric_make_np = NULL;
1483         fabric->tf_ops.fabric_drop_np = NULL;
1484         /*
1485          * Setup default attribute lists for various fabric->tf_cit_tmpl
1486          */
1487         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1488         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1489         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1490         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1491         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1492         /*
1493          * Once fabric->tf_ops has been setup, now register the fabric for
1494          * use within TCM
1495          */
1496         ret = target_fabric_configfs_register(fabric);
1497         if (ret < 0) {
1498                 pr_err("target_fabric_configfs_register() for"
1499                                 " TCM_Loop failed!\n");
1500                 target_fabric_configfs_free(fabric);
1501                 return -1;
1502         }
1503         /*
1504          * Setup our local pointer to *fabric.
1505          */
1506         tcm_loop_fabric_configfs = fabric;
1507         pr_debug("TCM_LOOP[0] - Set fabric ->"
1508                         " tcm_loop_fabric_configfs\n");
1509         return 0;
1510 }
1511
1512 static void tcm_loop_deregister_configfs(void)
1513 {
1514         if (!tcm_loop_fabric_configfs)
1515                 return;
1516
1517         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1518         tcm_loop_fabric_configfs = NULL;
1519         pr_debug("TCM_LOOP[0] - Cleared"
1520                                 " tcm_loop_fabric_configfs\n");
1521 }
1522
1523 static int __init tcm_loop_fabric_init(void)
1524 {
1525         int ret;
1526
1527         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1528                                 sizeof(struct tcm_loop_cmd),
1529                                 __alignof__(struct tcm_loop_cmd),
1530                                 0, NULL);
1531         if (!tcm_loop_cmd_cache) {
1532                 pr_debug("kmem_cache_create() for"
1533                         " tcm_loop_cmd_cache failed\n");
1534                 return -ENOMEM;
1535         }
1536
1537         ret = tcm_loop_alloc_core_bus();
1538         if (ret)
1539                 return ret;
1540
1541         ret = tcm_loop_register_configfs();
1542         if (ret) {
1543                 tcm_loop_release_core_bus();
1544                 return ret;
1545         }
1546
1547         return 0;
1548 }
1549
1550 static void __exit tcm_loop_fabric_exit(void)
1551 {
1552         tcm_loop_deregister_configfs();
1553         tcm_loop_release_core_bus();
1554         kmem_cache_destroy(tcm_loop_cmd_cache);
1555 }
1556
1557 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1558 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1559 MODULE_LICENSE("GPL");
1560 module_init(tcm_loop_fabric_init);
1561 module_exit(tcm_loop_fabric_exit);