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 <[email protected]>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  ****************************************************************************/
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/configfs.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_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                 printk(KERN_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                 T_TASK(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_get_lun_for_cmd(se_cmd, NULL, 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         transport_device_setup_cmd(se_cmd);
 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         void *mem_ptr, *mem_bidi_ptr = NULL;
 146         u32 sg_no_bidi = 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, tl_cmd->sc->cmnd);
 152         if (ret == -1) {
 153                 /* Out of Resources */
 154                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 155         } else if (ret == -2) {
 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          * Setup the struct scatterlist memory from the received
 169          * struct scsi_cmnd.
 170          */
 171         if (scsi_sg_count(sc)) {
 172                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM;
 173                 mem_ptr = (void *)scsi_sglist(sc);
 174                 /*
 175                  * For BIDI commands, pass in the extra READ buffer
 176                  * to transport_generic_map_mem_to_cmd() below..
 177                  */
 178                 if (T_TASK(se_cmd)->t_tasks_bidi) {
 179                         struct scsi_data_buffer *sdb = scsi_in(sc);
 180
 181                         mem_bidi_ptr = (void *)sdb->table.sgl;
 182                         sg_no_bidi = sdb->table.nents;
 183                 }
 184         } else {
 185                 /*
 186                  * Used for DMA_NONE
 187                  */
 188                 mem_ptr = NULL;
 189         }
 190         /*
 191          * Map the SG memory into struct se_mem->page linked list using the same
 192          * physical memory at sg->page_link.
 193          */
 194         ret = transport_generic_map_mem_to_cmd(se_cmd, mem_ptr,
 195                         scsi_sg_count(sc), mem_bidi_ptr, sg_no_bidi);
 196         if (ret < 0)
 197                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 198
 199         return 0;
 200 }
 201
 202 /*
 203  * Called from struct target_core_fabric_ops->check_stop_free()
 204  */
 205 static void tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 206 {
 207         /*
 208          * Do not release struct se_cmd's containing a valid TMR
 209          * pointer.  These will be released directly in tcm_loop_device_reset()
 210          * with transport_generic_free_cmd().
 211          */
 212         if (se_cmd->se_tmr_req)
 213                 return;
 214         /*
 215          * Release the struct se_cmd, which will make a callback to release
 216          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
 217          */
 218         transport_generic_free_cmd(se_cmd, 0, 1, 0);
 219 }
 220
 221 /*
 222  * Called from struct target_core_fabric_ops->release_cmd_to_pool()
 223  */
 224 static void tcm_loop_deallocate_core_cmd(struct se_cmd *se_cmd)
 225 {
 226         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 227                                 struct tcm_loop_cmd, tl_se_cmd);
 228
 229         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 230 }
 231
 232 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
 233                                 char **start, off_t offset,
 234                                 int length, int inout)
 235 {
 236         return sprintf(buffer, "tcm_loop_proc_info()\n");
 237 }
 238
 239 static int tcm_loop_driver_probe(struct device *);
 240 static int tcm_loop_driver_remove(struct device *);
 241
 242 static int pseudo_lld_bus_match(struct device *dev,
 243                                 struct device_driver *dev_driver)
 244 {
 245         return 1;
 246 }
 247
 248 static struct bus_type tcm_loop_lld_bus = {
 249         .name                   = "tcm_loop_bus",
 250         .match                  = pseudo_lld_bus_match,
 251         .probe                  = tcm_loop_driver_probe,
 252         .remove                 = tcm_loop_driver_remove,
 253 };
 254
 255 static struct device_driver tcm_loop_driverfs = {
 256         .name                   = "tcm_loop",
 257         .bus                    = &tcm_loop_lld_bus,
 258 };
 259 /*
 260  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 261  */
 262 struct device *tcm_loop_primary;
 263
 264 /*
 265  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 266  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 267  */
 268 static int tcm_loop_change_queue_depth(
 269         struct scsi_device *sdev,
 270         int depth,
 271         int reason)
 272 {
 273         switch (reason) {
 274         case SCSI_QDEPTH_DEFAULT:
 275                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 276                 break;
 277         case SCSI_QDEPTH_QFULL:
 278                 scsi_track_queue_full(sdev, depth);
 279                 break;
 280         case SCSI_QDEPTH_RAMP_UP:
 281                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 282                 break;
 283         default:
 284                 return -EOPNOTSUPP;
 285         }
 286         return sdev->queue_depth;
 287 }
 288
 289 /*
 290  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
 291  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
 292  */
 293 static int tcm_loop_queuecommand(
 294         struct Scsi_Host *sh,
 295         struct scsi_cmnd *sc)
 296 {
 297         struct se_cmd *se_cmd;
 298         struct se_portal_group *se_tpg;
 299         struct tcm_loop_hba *tl_hba;
 300         struct tcm_loop_tpg *tl_tpg;
 301
 302         TL_CDB_DEBUG("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 303                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 304                 sc->device->id, sc->device->channel, sc->device->lun,
 305                 sc->cmnd[0], scsi_bufflen(sc));
 306         /*
 307          * Locate the tcm_loop_hba_t pointer
 308          */
 309         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 310         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 311         se_tpg = &tl_tpg->tl_se_tpg;
 312         /*
 313          * Determine the SAM Task Attribute and allocate tl_cmd and
 314          * tl_cmd->tl_se_cmd from TCM infrastructure
 315          */
 316         se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
 317         if (!se_cmd) {
 318                 sc->scsi_done(sc);
 319                 return 0;
 320         }
 321         /*
 322          * Queue up the newly allocated to be processed in TCM thread context.
 323         */
 324         transport_generic_handle_cdb_map(se_cmd);
 325         return 0;
 326 }
 327
 328 /*
 329  * Called from SCSI EH process context to issue a LUN_RESET TMR
 330  * to struct scsi_device
 331  */
 332 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 333 {
 334         struct se_cmd *se_cmd = NULL;
 335         struct se_portal_group *se_tpg;
 336         struct se_session *se_sess;
 337         struct tcm_loop_cmd *tl_cmd = NULL;
 338         struct tcm_loop_hba *tl_hba;
 339         struct tcm_loop_nexus *tl_nexus;
 340         struct tcm_loop_tmr *tl_tmr = NULL;
 341         struct tcm_loop_tpg *tl_tpg;
 342         int ret = FAILED;
 343         /*
 344          * Locate the tcm_loop_hba_t pointer
 345          */
 346         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 347         /*
 348          * Locate the tl_nexus and se_sess pointers
 349          */
 350         tl_nexus = tl_hba->tl_nexus;
 351         if (!tl_nexus) {
 352                 printk(KERN_ERR "Unable to perform device reset without"
 353                                 " active I_T Nexus\n");
 354                 return FAILED;
 355         }
 356         se_sess = tl_nexus->se_sess;
 357         /*
 358          * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
 359          */
 360         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 361         se_tpg = &tl_tpg->tl_se_tpg;
 362
 363         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 364         if (!tl_cmd) {
 365                 printk(KERN_ERR "Unable to allocate memory for tl_cmd\n");
 366                 return FAILED;
 367         }
 368
 369         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 370         if (!tl_tmr) {
 371                 printk(KERN_ERR "Unable to allocate memory for tl_tmr\n");
 372                 goto release;
 373         }
 374         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 375
 376         se_cmd = &tl_cmd->tl_se_cmd;
 377         /*
 378          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 379          */
 380         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 381                                 DMA_NONE, MSG_SIMPLE_TAG,
 382                                 &tl_cmd->tl_sense_buf[0]);
 383         /*
 384          * Allocate the LUN_RESET TMR
 385          */
 386         se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, (void *)tl_tmr,
 387                                 TMR_LUN_RESET);
 388         if (IS_ERR(se_cmd->se_tmr_req))
 389                 goto release;
 390         /*
 391          * Locate the underlying TCM struct se_lun from sc->device->lun
 392          */
 393         if (transport_get_lun_for_tmr(se_cmd, sc->device->lun) < 0)
 394                 goto release;
 395         /*
 396          * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
 397          * to wake us up.
 398          */
 399         transport_generic_handle_tmr(se_cmd);
 400         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 401         /*
 402          * The TMR LUN_RESET has completed, check the response status and
 403          * then release allocations.
 404          */
 405         ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 406                 SUCCESS : FAILED;
 407 release:
 408         if (se_cmd)
 409                 transport_generic_free_cmd(se_cmd, 1, 1, 0);
 410         else
 411                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 412         kfree(tl_tmr);
 413         return ret;
 414 }
 415
 416 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 417 {
 418         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 419         return 0;
 420 }
 421
 422 static int tcm_loop_slave_configure(struct scsi_device *sd)
 423 {
 424         return 0;
 425 }
 426
 427 static struct scsi_host_template tcm_loop_driver_template = {
 428         .proc_info              = tcm_loop_proc_info,
 429         .proc_name              = "tcm_loopback",
 430         .name                   = "TCM_Loopback",
 431         .queuecommand           = tcm_loop_queuecommand,
 432         .change_queue_depth     = tcm_loop_change_queue_depth,
 433         .eh_device_reset_handler = tcm_loop_device_reset,
 434         .can_queue              = TL_SCSI_CAN_QUEUE,
 435         .this_id                = -1,
 436         .sg_tablesize           = TL_SCSI_SG_TABLESIZE,
 437         .cmd_per_lun            = TL_SCSI_CMD_PER_LUN,
 438         .max_sectors            = TL_SCSI_MAX_SECTORS,
 439         .use_clustering         = DISABLE_CLUSTERING,
 440         .slave_alloc            = tcm_loop_slave_alloc,
 441         .slave_configure        = tcm_loop_slave_configure,
 442         .module                 = THIS_MODULE,
 443 };
 444
 445 static int tcm_loop_driver_probe(struct device *dev)
 446 {
 447         struct tcm_loop_hba *tl_hba;
 448         struct Scsi_Host *sh;
 449         int error;
 450
 451         tl_hba = to_tcm_loop_hba(dev);
 452
 453         sh = scsi_host_alloc(&tcm_loop_driver_template,
 454                         sizeof(struct tcm_loop_hba));
 455         if (!sh) {
 456                 printk(KERN_ERR "Unable to allocate struct scsi_host\n");
 457                 return -ENODEV;
 458         }
 459         tl_hba->sh = sh;
 460
 461         /*
 462          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 463          */
 464         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 465         /*
 466          * Setup single ID, Channel and LUN for now..
 467          */
 468         sh->max_id = 2;
 469         sh->max_lun = 0;
 470         sh->max_channel = 0;
 471         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 472
 473         error = scsi_add_host(sh, &tl_hba->dev);
 474         if (error) {
 475                 printk(KERN_ERR "%s: scsi_add_host failed\n", __func__);
 476                 scsi_host_put(sh);
 477                 return -ENODEV;
 478         }
 479         return 0;
 480 }
 481
 482 static int tcm_loop_driver_remove(struct device *dev)
 483 {
 484         struct tcm_loop_hba *tl_hba;
 485         struct Scsi_Host *sh;
 486
 487         tl_hba = to_tcm_loop_hba(dev);
 488         sh = tl_hba->sh;
 489
 490         scsi_remove_host(sh);
 491         scsi_host_put(sh);
 492         return 0;
 493 }
 494
 495 static void tcm_loop_release_adapter(struct device *dev)
 496 {
 497         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 498
 499         kfree(tl_hba);
 500 }
 501
 502 /*
 503  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 504  */
 505 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 506 {
 507         int ret;
 508
 509         tl_hba->dev.bus = &tcm_loop_lld_bus;
 510         tl_hba->dev.parent = tcm_loop_primary;
 511         tl_hba->dev.release = &tcm_loop_release_adapter;
 512         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 513
 514         ret = device_register(&tl_hba->dev);
 515         if (ret) {
 516                 printk(KERN_ERR "device_register() failed for"
 517                                 " tl_hba->dev: %d\n", ret);
 518                 return -ENODEV;
 519         }
 520
 521         return 0;
 522 }
 523
 524 /*
 525  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 526  * tcm_loop SCSI bus.
 527  */
 528 static int tcm_loop_alloc_core_bus(void)
 529 {
 530         int ret;
 531
 532         tcm_loop_primary = root_device_register("tcm_loop_0");
 533         if (IS_ERR(tcm_loop_primary)) {
 534                 printk(KERN_ERR "Unable to allocate tcm_loop_primary\n");
 535                 return PTR_ERR(tcm_loop_primary);
 536         }
 537
 538         ret = bus_register(&tcm_loop_lld_bus);
 539         if (ret) {
 540                 printk(KERN_ERR "bus_register() failed for tcm_loop_lld_bus\n");
 541                 goto dev_unreg;
 542         }
 543
 544         ret = driver_register(&tcm_loop_driverfs);
 545         if (ret) {
 546                 printk(KERN_ERR "driver_register() failed for"
 547                                 "tcm_loop_driverfs\n");
 548                 goto bus_unreg;
 549         }
 550
 551         printk(KERN_INFO "Initialized TCM Loop Core Bus\n");
 552         return ret;
 553
 554 bus_unreg:
 555         bus_unregister(&tcm_loop_lld_bus);
 556 dev_unreg:
 557         root_device_unregister(tcm_loop_primary);
 558         return ret;
 559 }
 560
 561 static void tcm_loop_release_core_bus(void)
 562 {
 563         driver_unregister(&tcm_loop_driverfs);
 564         bus_unregister(&tcm_loop_lld_bus);
 565         root_device_unregister(tcm_loop_primary);
 566
 567         printk(KERN_INFO "Releasing TCM Loop Core BUS\n");
 568 }
 569
 570 static char *tcm_loop_get_fabric_name(void)
 571 {
 572         return "loopback";
 573 }
 574
 575 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 576 {
 577         struct tcm_loop_tpg *tl_tpg =
 578                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 579         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 580         /*
 581          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 582          * time based on the protocol dependent prefix of the passed configfs group.
 583          *
 584          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 585          * ProtocolID using target_core_fabric_lib.c symbols.
 586          */
 587         switch (tl_hba->tl_proto_id) {
 588         case SCSI_PROTOCOL_SAS:
 589                 return sas_get_fabric_proto_ident(se_tpg);
 590         case SCSI_PROTOCOL_FCP:
 591                 return fc_get_fabric_proto_ident(se_tpg);
 592         case SCSI_PROTOCOL_ISCSI:
 593                 return iscsi_get_fabric_proto_ident(se_tpg);
 594         default:
 595                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 596                         " SAS emulation\n", tl_hba->tl_proto_id);
 597                 break;
 598         }
 599
 600         return sas_get_fabric_proto_ident(se_tpg);
 601 }
 602
 603 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 604 {
 605         struct tcm_loop_tpg *tl_tpg =
 606                 (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 607         /*
 608          * Return the passed NAA identifier for the SAS Target Port
 609          */
 610         return &tl_tpg->tl_hba->tl_wwn_address[0];
 611 }
 612
 613 static u16 tcm_loop_get_tag(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          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 619          * to represent the SCSI Target Port.
 620          */
 621         return tl_tpg->tl_tpgt;
 622 }
 623
 624 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 625 {
 626         return 1;
 627 }
 628
 629 static u32 tcm_loop_get_pr_transport_id(
 630         struct se_portal_group *se_tpg,
 631         struct se_node_acl *se_nacl,
 632         struct t10_pr_registration *pr_reg,
 633         int *format_code,
 634         unsigned char *buf)
 635 {
 636         struct tcm_loop_tpg *tl_tpg =
 637                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 638         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 639
 640         switch (tl_hba->tl_proto_id) {
 641         case SCSI_PROTOCOL_SAS:
 642                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 643                                         format_code, buf);
 644         case SCSI_PROTOCOL_FCP:
 645                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 646                                         format_code, buf);
 647         case SCSI_PROTOCOL_ISCSI:
 648                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 649                                         format_code, buf);
 650         default:
 651                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 652                         " SAS emulation\n", tl_hba->tl_proto_id);
 653                 break;
 654         }
 655
 656         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 657                         format_code, buf);
 658 }
 659
 660 static u32 tcm_loop_get_pr_transport_id_len(
 661         struct se_portal_group *se_tpg,
 662         struct se_node_acl *se_nacl,
 663         struct t10_pr_registration *pr_reg,
 664         int *format_code)
 665 {
 666         struct tcm_loop_tpg *tl_tpg =
 667                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 668         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 669
 670         switch (tl_hba->tl_proto_id) {
 671         case SCSI_PROTOCOL_SAS:
 672                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 673                                         format_code);
 674         case SCSI_PROTOCOL_FCP:
 675                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 676                                         format_code);
 677         case SCSI_PROTOCOL_ISCSI:
 678                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 679                                         format_code);
 680         default:
 681                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 682                         " SAS emulation\n", tl_hba->tl_proto_id);
 683                 break;
 684         }
 685
 686         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 687                         format_code);
 688 }
 689
 690 /*
 691  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 692  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 693  */
 694 static char *tcm_loop_parse_pr_out_transport_id(
 695         struct se_portal_group *se_tpg,
 696         const char *buf,
 697         u32 *out_tid_len,
 698         char **port_nexus_ptr)
 699 {
 700         struct tcm_loop_tpg *tl_tpg =
 701                         (struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
 702         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 703
 704         switch (tl_hba->tl_proto_id) {
 705         case SCSI_PROTOCOL_SAS:
 706                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 707                                         port_nexus_ptr);
 708         case SCSI_PROTOCOL_FCP:
 709                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 710                                         port_nexus_ptr);
 711         case SCSI_PROTOCOL_ISCSI:
 712                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 713                                         port_nexus_ptr);
 714         default:
 715                 printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
 716                         " SAS emulation\n", tl_hba->tl_proto_id);
 717                 break;
 718         }
 719
 720         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 721                         port_nexus_ptr);
 722 }
 723
 724 /*
 725  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 726  * based upon the incoming fabric dependent SCSI Initiator Port
 727  */
 728 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 729 {
 730         return 1;
 731 }
 732
 733 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 734 {
 735         return 0;
 736 }
 737
 738 /*
 739  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 740  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 741  */
 742 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 743 {
 744         return 0;
 745 }
 746
 747 /*
 748  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 749  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 750  * It has been added here as a nop for target_fabric_tf_ops_check()
 751  */
 752 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 753 {
 754         return 0;
 755 }
 756
 757 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 758         struct se_portal_group *se_tpg)
 759 {
 760         struct tcm_loop_nacl *tl_nacl;
 761
 762         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 763         if (!tl_nacl) {
 764                 printk(KERN_ERR "Unable to allocate struct tcm_loop_nacl\n");
 765                 return NULL;
 766         }
 767
 768         return &tl_nacl->se_node_acl;
 769 }
 770
 771 static void tcm_loop_tpg_release_fabric_acl(
 772         struct se_portal_group *se_tpg,
 773         struct se_node_acl *se_nacl)
 774 {
 775         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 776                                 struct tcm_loop_nacl, se_node_acl);
 777
 778         kfree(tl_nacl);
 779 }
 780
 781 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 782 {
 783         return 1;
 784 }
 785
 786 static void tcm_loop_new_cmd_failure(struct se_cmd *se_cmd)
 787 {
 788         /*
 789          * Since TCM_loop is already passing struct scatterlist data from
 790          * struct scsi_cmnd, no more Linux/SCSI failure dependent state need
 791          * to be handled here.
 792          */
 793         return;
 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         TL_CDB_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         TL_CDB_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((void *)sc->sense_buffer, (void *)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         printk(KERN_INFO "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                 printk(KERN_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         printk(KERN_INFO "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                 printk(KERN_INFO "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                 printk(KERN_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, (void *)tl_nexus);
1057         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1058         printk(KERN_INFO "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                 printk(KERN_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         printk(KERN_INFO "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                 printk(KERN_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                         printk(KERN_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                         printk(KERN_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                         printk(KERN_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         printk(KERN_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                 printk(KERN_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                 printk(KERN_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, (void *)tl_tpg,
1245                         TRANSPORT_TPG_TYPE_NORMAL);
1246         if (ret < 0)
1247                 return ERR_PTR(-ENOMEM);
1248
1249         printk(KERN_INFO "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         printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated Emulated %s"
1277                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1278                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1279 }
1280
1281 /* End items for tcm_loop_naa_cit */
1282
1283 /* Start items for tcm_loop_cit */
1284
1285 struct se_wwn *tcm_loop_make_scsi_hba(
1286         struct target_fabric_configfs *tf,
1287         struct config_group *group,
1288         const char *name)
1289 {
1290         struct tcm_loop_hba *tl_hba;
1291         struct Scsi_Host *sh;
1292         char *ptr;
1293         int ret, off = 0;
1294
1295         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1296         if (!tl_hba) {
1297                 printk(KERN_ERR "Unable to allocate struct tcm_loop_hba\n");
1298                 return ERR_PTR(-ENOMEM);
1299         }
1300         /*
1301          * Determine the emulated Protocol Identifier and Target Port Name
1302          * based on the incoming configfs directory name.
1303          */
1304         ptr = strstr(name, "naa.");
1305         if (ptr) {
1306                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1307                 goto check_len;
1308         }
1309         ptr = strstr(name, "fc.");
1310         if (ptr) {
1311                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1312                 off = 3; /* Skip over "fc." */
1313                 goto check_len;
1314         }
1315         ptr = strstr(name, "iqn.");
1316         if (ptr) {
1317                 tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1318                 goto check_len;
1319         }
1320
1321         printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
1322                         " %s\n", name);
1323         return ERR_PTR(-EINVAL);
1324
1325 check_len:
1326         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1327                 printk(KERN_ERR "Emulated NAA %s Address: %s, exceeds"
1328                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1329                         TL_WWN_ADDR_LEN);
1330                 kfree(tl_hba);
1331                 return ERR_PTR(-EINVAL);
1332         }
1333         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1334
1335         /*
1336          * Call device_register(tl_hba->dev) to register the emulated
1337          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1338          * device_register() callbacks in tcm_loop_driver_probe()
1339          */
1340         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1341         if (ret)
1342                 goto out;
1343
1344         sh = tl_hba->sh;
1345         tcm_loop_hba_no_cnt++;
1346         printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated emulated Target"
1347                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1348                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1349
1350         return &tl_hba->tl_hba_wwn;
1351 out:
1352         kfree(tl_hba);
1353         return ERR_PTR(ret);
1354 }
1355
1356 void tcm_loop_drop_scsi_hba(
1357         struct se_wwn *wwn)
1358 {
1359         struct tcm_loop_hba *tl_hba = container_of(wwn,
1360                                 struct tcm_loop_hba, tl_hba_wwn);
1361         int host_no = tl_hba->sh->host_no;
1362         /*
1363          * Call device_unregister() on the original tl_hba->dev.
1364          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1365          * release *tl_hba;
1366          */
1367         device_unregister(&tl_hba->dev);
1368
1369         printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated emulated Target"
1370                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1371                 config_item_name(&wwn->wwn_group.cg_item), host_no);
1372 }
1373
1374 /* Start items for tcm_loop_cit */
1375 static ssize_t tcm_loop_wwn_show_attr_version(
1376         struct target_fabric_configfs *tf,
1377         char *page)
1378 {
1379         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1380 }
1381
1382 TF_WWN_ATTR_RO(tcm_loop, version);
1383
1384 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1385         &tcm_loop_wwn_version.attr,
1386         NULL,
1387 };
1388
1389 /* End items for tcm_loop_cit */
1390
1391 static int tcm_loop_register_configfs(void)
1392 {
1393         struct target_fabric_configfs *fabric;
1394         struct config_group *tf_cg;
1395         int ret;
1396         /*
1397          * Set the TCM Loop HBA counter to zero
1398          */
1399         tcm_loop_hba_no_cnt = 0;
1400         /*
1401          * Register the top level struct config_item_type with TCM core
1402          */
1403         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1404         if (!fabric) {
1405                 printk(KERN_ERR "tcm_loop_register_configfs() failed!\n");
1406                 return -1;
1407         }
1408         /*
1409          * Setup the fabric API of function pointers used by target_core_mod
1410          */
1411         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1412         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1413         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1414         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1415         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1416         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1417         fabric->tf_ops.tpg_get_pr_transport_id_len =
1418                                         &tcm_loop_get_pr_transport_id_len;
1419         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1420                                         &tcm_loop_parse_pr_out_transport_id;
1421         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1422         fabric->tf_ops.tpg_check_demo_mode_cache =
1423                                         &tcm_loop_check_demo_mode_cache;
1424         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1425                                         &tcm_loop_check_demo_mode_write_protect;
1426         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1427                                         &tcm_loop_check_prod_mode_write_protect;
1428         /*
1429          * The TCM loopback fabric module runs in demo-mode to a local
1430          * virtual SCSI device, so fabric dependent initator ACLs are
1431          * not required.
1432          */
1433         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1434         fabric->tf_ops.tpg_release_fabric_acl =
1435                                         &tcm_loop_tpg_release_fabric_acl;
1436         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1437         /*
1438          * Since tcm_loop is mapping physical memory from Linux/SCSI
1439          * struct scatterlist arrays for each struct scsi_cmnd I/O,
1440          * we do not need TCM to allocate a iovec array for
1441          * virtual memory address mappings
1442          */
1443         fabric->tf_ops.alloc_cmd_iovecs = NULL;
1444         /*
1445          * Used for setting up remaining TCM resources in process context
1446          */
1447         fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1448         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1449         fabric->tf_ops.release_cmd_to_pool = &tcm_loop_deallocate_core_cmd;
1450         fabric->tf_ops.release_cmd_direct = &tcm_loop_deallocate_core_cmd;
1451         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1452         fabric->tf_ops.close_session = &tcm_loop_close_session;
1453         fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1454         fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1455         fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1456         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1457         fabric->tf_ops.sess_get_initiator_sid = NULL;
1458         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1459         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1460         /*
1461          * Not used for TCM loopback
1462          */
1463         fabric->tf_ops.set_default_node_attributes =
1464                                         &tcm_loop_set_default_node_attributes;
1465         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1466         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1467         fabric->tf_ops.new_cmd_failure = &tcm_loop_new_cmd_failure;
1468         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1469         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1470         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1471         fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1472         fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1473         fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1474
1475         tf_cg = &fabric->tf_group;
1476         /*
1477          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1478          */
1479         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1480         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1481         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1482         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1483         /*
1484          * fabric_post_link() and fabric_pre_unlink() are used for
1485          * registration and release of TCM Loop Virtual SCSI LUNs.
1486          */
1487         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1488         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1489         fabric->tf_ops.fabric_make_np = NULL;
1490         fabric->tf_ops.fabric_drop_np = NULL;
1491         /*
1492          * Setup default attribute lists for various fabric->tf_cit_tmpl
1493          */
1494         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1495         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1496         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1497         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1498         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1499         /*
1500          * Once fabric->tf_ops has been setup, now register the fabric for
1501          * use within TCM
1502          */
1503         ret = target_fabric_configfs_register(fabric);
1504         if (ret < 0) {
1505                 printk(KERN_ERR "target_fabric_configfs_register() for"
1506                                 " TCM_Loop failed!\n");
1507                 target_fabric_configfs_free(fabric);
1508                 return -1;
1509         }
1510         /*
1511          * Setup our local pointer to *fabric.
1512          */
1513         tcm_loop_fabric_configfs = fabric;
1514         printk(KERN_INFO "TCM_LOOP[0] - Set fabric ->"
1515                         " tcm_loop_fabric_configfs\n");
1516         return 0;
1517 }
1518
1519 static void tcm_loop_deregister_configfs(void)
1520 {
1521         if (!tcm_loop_fabric_configfs)
1522                 return;
1523
1524         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1525         tcm_loop_fabric_configfs = NULL;
1526         printk(KERN_INFO "TCM_LOOP[0] - Cleared"
1527                                 " tcm_loop_fabric_configfs\n");
1528 }
1529
1530 static int __init tcm_loop_fabric_init(void)
1531 {
1532         int ret;
1533
1534         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1535                                 sizeof(struct tcm_loop_cmd),
1536                                 __alignof__(struct tcm_loop_cmd),
1537                                 0, NULL);
1538         if (!tcm_loop_cmd_cache) {
1539                 printk(KERN_ERR "kmem_cache_create() for"
1540                         " tcm_loop_cmd_cache failed\n");
1541                 return -ENOMEM;
1542         }
1543
1544         ret = tcm_loop_alloc_core_bus();
1545         if (ret)
1546                 return ret;
1547
1548         ret = tcm_loop_register_configfs();
1549         if (ret) {
1550                 tcm_loop_release_core_bus();
1551                 return ret;
1552         }
1553
1554         return 0;
1555 }
1556
1557 static void __exit tcm_loop_fabric_exit(void)
1558 {
1559         tcm_loop_deregister_configfs();
1560         tcm_loop_release_core_bus();
1561         kmem_cache_destroy(tcm_loop_cmd_cache);
1562 }
1563
1564 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1565 MODULE_AUTHOR("Nicholas A. Bellinger <[email protected]>");
1566 MODULE_LICENSE("GPL");
1567 module_init(tcm_loop_fabric_init);
1568 module_exit(tcm_loop_fabric_exit);