xref: /linux/drivers/target/loopback/tcm_loop.c (revision 08694199477da412baf1852c6d1bf5fedbd40c7e)
1 /*******************************************************************************
2  *
3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
4  * for emulated SAS initiator ports
5  *
6  * © Copyright 2011-2013 Datera, Inc.
7  *
8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
9  *
10  * Author: Nicholas A. Bellinger <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_fabric.h>
37 
38 #include "tcm_loop.h"
39 
40 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
41 
42 static struct workqueue_struct *tcm_loop_workqueue;
43 static struct kmem_cache *tcm_loop_cmd_cache;
44 
45 static int tcm_loop_hba_no_cnt;
46 
47 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
48 
49 static unsigned int tcm_loop_nr_hw_queues = 1;
50 module_param_named(nr_hw_queues, tcm_loop_nr_hw_queues, uint, 0644);
51 
52 static unsigned int tcm_loop_can_queue = 1024;
53 module_param_named(can_queue, tcm_loop_can_queue, uint, 0644);
54 
55 static unsigned int tcm_loop_cmd_per_lun = 1024;
56 module_param_named(cmd_per_lun, tcm_loop_cmd_per_lun, uint, 0644);
57 
58 /*
59  * Called from struct target_core_fabric_ops->check_stop_free()
60  */
61 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
62 {
63 	return transport_generic_free_cmd(se_cmd, 0);
64 }
65 
66 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
67 {
68 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
69 				struct tcm_loop_cmd, tl_se_cmd);
70 
71 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
72 }
73 
74 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
75 {
76 	seq_puts(m, "tcm_loop_proc_info()\n");
77 	return 0;
78 }
79 
80 static int tcm_loop_driver_probe(struct device *);
81 static int tcm_loop_driver_remove(struct device *);
82 
83 static int pseudo_lld_bus_match(struct device *dev,
84 				struct device_driver *dev_driver)
85 {
86 	return 1;
87 }
88 
89 static struct bus_type tcm_loop_lld_bus = {
90 	.name			= "tcm_loop_bus",
91 	.match			= pseudo_lld_bus_match,
92 	.probe			= tcm_loop_driver_probe,
93 	.remove			= tcm_loop_driver_remove,
94 };
95 
96 static struct device_driver tcm_loop_driverfs = {
97 	.name			= "tcm_loop",
98 	.bus			= &tcm_loop_lld_bus,
99 };
100 /*
101  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
102  */
103 static struct device *tcm_loop_primary;
104 
105 static void tcm_loop_submission_work(struct work_struct *work)
106 {
107 	struct tcm_loop_cmd *tl_cmd =
108 		container_of(work, struct tcm_loop_cmd, work);
109 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
110 	struct scsi_cmnd *sc = tl_cmd->sc;
111 	struct tcm_loop_nexus *tl_nexus;
112 	struct tcm_loop_hba *tl_hba;
113 	struct tcm_loop_tpg *tl_tpg;
114 	struct scatterlist *sgl_bidi = NULL;
115 	u32 sgl_bidi_count = 0, transfer_length;
116 
117 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
118 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
119 
120 	/*
121 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
122 	 * has already been configured via tcm_loop_make_naa_tpg().
123 	 */
124 	if (!tl_tpg->tl_hba) {
125 		set_host_byte(sc, DID_NO_CONNECT);
126 		goto out_done;
127 	}
128 	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
129 		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
130 		goto out_done;
131 	}
132 	tl_nexus = tl_tpg->tl_nexus;
133 	if (!tl_nexus) {
134 		scmd_printk(KERN_ERR, sc,
135 			    "TCM_Loop I_T Nexus does not exist\n");
136 		set_host_byte(sc, DID_ERROR);
137 		goto out_done;
138 	}
139 
140 	transfer_length = scsi_transfer_length(sc);
141 	if (!scsi_prot_sg_count(sc) &&
142 	    scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
143 		se_cmd->prot_pto = true;
144 		/*
145 		 * loopback transport doesn't support
146 		 * WRITE_GENERATE, READ_STRIP protection
147 		 * information operations, go ahead unprotected.
148 		 */
149 		transfer_length = scsi_bufflen(sc);
150 	}
151 
152 	se_cmd->tag = tl_cmd->sc_cmd_tag;
153 	target_init_cmd(se_cmd, tl_nexus->se_sess, &tl_cmd->tl_sense_buf[0],
154 			tl_cmd->sc->device->lun, transfer_length,
155 			TCM_SIMPLE_TAG, sc->sc_data_direction, 0);
156 
157 	if (target_submit_prep(se_cmd, sc->cmnd, scsi_sglist(sc),
158 			       scsi_sg_count(sc), sgl_bidi, sgl_bidi_count,
159 			       scsi_prot_sglist(sc), scsi_prot_sg_count(sc),
160 			       GFP_NOIO))
161 		return;
162 
163 	target_submit(se_cmd);
164 	return;
165 
166 out_done:
167 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
168 	sc->scsi_done(sc);
169 }
170 
171 /*
172  * ->queuecommand can be and usually is called from interrupt context, so
173  * defer the actual submission to a workqueue.
174  */
175 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
176 {
177 	struct tcm_loop_cmd *tl_cmd;
178 
179 	pr_debug("%s() %d:%d:%d:%llu got CDB: 0x%02x scsi_buf_len: %u\n",
180 		 __func__, sc->device->host->host_no, sc->device->id,
181 		 sc->device->channel, sc->device->lun, sc->cmnd[0],
182 		 scsi_bufflen(sc));
183 
184 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
185 	if (!tl_cmd) {
186 		set_host_byte(sc, DID_ERROR);
187 		sc->scsi_done(sc);
188 		return 0;
189 	}
190 
191 	tl_cmd->sc = sc;
192 	tl_cmd->sc_cmd_tag = sc->request->tag;
193 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
194 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
195 	return 0;
196 }
197 
198 /*
199  * Called from SCSI EH process context to issue a LUN_RESET TMR
200  * to struct scsi_device
201  */
202 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
203 			      u64 lun, int task, enum tcm_tmreq_table tmr)
204 {
205 	struct se_cmd *se_cmd;
206 	struct se_session *se_sess;
207 	struct tcm_loop_nexus *tl_nexus;
208 	struct tcm_loop_cmd *tl_cmd;
209 	int ret = TMR_FUNCTION_FAILED, rc;
210 
211 	/*
212 	 * Locate the tl_nexus and se_sess pointers
213 	 */
214 	tl_nexus = tl_tpg->tl_nexus;
215 	if (!tl_nexus) {
216 		pr_err("Unable to perform device reset without active I_T Nexus\n");
217 		return ret;
218 	}
219 
220 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
221 	if (!tl_cmd)
222 		return ret;
223 
224 	init_completion(&tl_cmd->tmr_done);
225 
226 	se_cmd = &tl_cmd->tl_se_cmd;
227 	se_sess = tl_tpg->tl_nexus->se_sess;
228 
229 	rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun,
230 			       NULL, tmr, GFP_KERNEL, task,
231 			       TARGET_SCF_ACK_KREF);
232 	if (rc < 0)
233 		goto release;
234 	wait_for_completion(&tl_cmd->tmr_done);
235 	ret = se_cmd->se_tmr_req->response;
236 	target_put_sess_cmd(se_cmd);
237 
238 out:
239 	return ret;
240 
241 release:
242 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
243 	goto out;
244 }
245 
246 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
247 {
248 	struct tcm_loop_hba *tl_hba;
249 	struct tcm_loop_tpg *tl_tpg;
250 	int ret = FAILED;
251 
252 	/*
253 	 * Locate the tcm_loop_hba_t pointer
254 	 */
255 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
256 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
257 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
258 				 sc->request->tag, TMR_ABORT_TASK);
259 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
260 }
261 
262 /*
263  * Called from SCSI EH process context to issue a LUN_RESET TMR
264  * to struct scsi_device
265  */
266 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
267 {
268 	struct tcm_loop_hba *tl_hba;
269 	struct tcm_loop_tpg *tl_tpg;
270 	int ret = FAILED;
271 
272 	/*
273 	 * Locate the tcm_loop_hba_t pointer
274 	 */
275 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
276 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
277 
278 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
279 				 0, TMR_LUN_RESET);
280 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
281 }
282 
283 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
284 {
285 	struct tcm_loop_hba *tl_hba;
286 	struct tcm_loop_tpg *tl_tpg;
287 
288 	/*
289 	 * Locate the tcm_loop_hba_t pointer
290 	 */
291 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
292 	if (!tl_hba) {
293 		pr_err("Unable to perform device reset without active I_T Nexus\n");
294 		return FAILED;
295 	}
296 	/*
297 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
298 	 */
299 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
300 	if (tl_tpg) {
301 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
302 		return SUCCESS;
303 	}
304 	return FAILED;
305 }
306 
307 static struct scsi_host_template tcm_loop_driver_template = {
308 	.show_info		= tcm_loop_show_info,
309 	.proc_name		= "tcm_loopback",
310 	.name			= "TCM_Loopback",
311 	.queuecommand		= tcm_loop_queuecommand,
312 	.change_queue_depth	= scsi_change_queue_depth,
313 	.eh_abort_handler = tcm_loop_abort_task,
314 	.eh_device_reset_handler = tcm_loop_device_reset,
315 	.eh_target_reset_handler = tcm_loop_target_reset,
316 	.this_id		= -1,
317 	.sg_tablesize		= 256,
318 	.max_sectors		= 0xFFFF,
319 	.dma_boundary		= PAGE_SIZE - 1,
320 	.module			= THIS_MODULE,
321 	.track_queue_depth	= 1,
322 };
323 
324 static int tcm_loop_driver_probe(struct device *dev)
325 {
326 	struct tcm_loop_hba *tl_hba;
327 	struct Scsi_Host *sh;
328 	int error, host_prot;
329 
330 	tl_hba = to_tcm_loop_hba(dev);
331 
332 	sh = scsi_host_alloc(&tcm_loop_driver_template,
333 			sizeof(struct tcm_loop_hba));
334 	if (!sh) {
335 		pr_err("Unable to allocate struct scsi_host\n");
336 		return -ENODEV;
337 	}
338 	tl_hba->sh = sh;
339 
340 	/*
341 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
342 	 */
343 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
344 	/*
345 	 * Setup single ID, Channel and LUN for now..
346 	 */
347 	sh->max_id = 2;
348 	sh->max_lun = 0;
349 	sh->max_channel = 0;
350 	sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
351 	sh->nr_hw_queues = tcm_loop_nr_hw_queues;
352 	sh->can_queue = tcm_loop_can_queue;
353 	sh->cmd_per_lun = tcm_loop_cmd_per_lun;
354 
355 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
356 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
357 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
358 
359 	scsi_host_set_prot(sh, host_prot);
360 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
361 
362 	error = scsi_add_host(sh, &tl_hba->dev);
363 	if (error) {
364 		pr_err("%s: scsi_add_host failed\n", __func__);
365 		scsi_host_put(sh);
366 		return -ENODEV;
367 	}
368 	return 0;
369 }
370 
371 static int tcm_loop_driver_remove(struct device *dev)
372 {
373 	struct tcm_loop_hba *tl_hba;
374 	struct Scsi_Host *sh;
375 
376 	tl_hba = to_tcm_loop_hba(dev);
377 	sh = tl_hba->sh;
378 
379 	scsi_remove_host(sh);
380 	scsi_host_put(sh);
381 	return 0;
382 }
383 
384 static void tcm_loop_release_adapter(struct device *dev)
385 {
386 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
387 
388 	kfree(tl_hba);
389 }
390 
391 /*
392  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
393  */
394 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
395 {
396 	int ret;
397 
398 	tl_hba->dev.bus = &tcm_loop_lld_bus;
399 	tl_hba->dev.parent = tcm_loop_primary;
400 	tl_hba->dev.release = &tcm_loop_release_adapter;
401 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
402 
403 	ret = device_register(&tl_hba->dev);
404 	if (ret) {
405 		pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
406 		return -ENODEV;
407 	}
408 
409 	return 0;
410 }
411 
412 /*
413  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
414  * tcm_loop SCSI bus.
415  */
416 static int tcm_loop_alloc_core_bus(void)
417 {
418 	int ret;
419 
420 	tcm_loop_primary = root_device_register("tcm_loop_0");
421 	if (IS_ERR(tcm_loop_primary)) {
422 		pr_err("Unable to allocate tcm_loop_primary\n");
423 		return PTR_ERR(tcm_loop_primary);
424 	}
425 
426 	ret = bus_register(&tcm_loop_lld_bus);
427 	if (ret) {
428 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
429 		goto dev_unreg;
430 	}
431 
432 	ret = driver_register(&tcm_loop_driverfs);
433 	if (ret) {
434 		pr_err("driver_register() failed for tcm_loop_driverfs\n");
435 		goto bus_unreg;
436 	}
437 
438 	pr_debug("Initialized TCM Loop Core Bus\n");
439 	return ret;
440 
441 bus_unreg:
442 	bus_unregister(&tcm_loop_lld_bus);
443 dev_unreg:
444 	root_device_unregister(tcm_loop_primary);
445 	return ret;
446 }
447 
448 static void tcm_loop_release_core_bus(void)
449 {
450 	driver_unregister(&tcm_loop_driverfs);
451 	bus_unregister(&tcm_loop_lld_bus);
452 	root_device_unregister(tcm_loop_primary);
453 
454 	pr_debug("Releasing TCM Loop Core BUS\n");
455 }
456 
457 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
458 {
459 	return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
460 }
461 
462 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
463 {
464 	/*
465 	 * Return the passed NAA identifier for the Target Port
466 	 */
467 	return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
468 }
469 
470 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
471 {
472 	/*
473 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
474 	 * to represent the SCSI Target Port.
475 	 */
476 	return tl_tpg(se_tpg)->tl_tpgt;
477 }
478 
479 /*
480  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
481  * based upon the incoming fabric dependent SCSI Initiator Port
482  */
483 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
484 {
485 	return 1;
486 }
487 
488 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
489 {
490 	return 0;
491 }
492 
493 /*
494  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
495  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
496  */
497 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
498 {
499 	return 0;
500 }
501 
502 /*
503  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
504  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
505  * It has been added here as a nop for target_fabric_tf_ops_check()
506  */
507 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
508 {
509 	return 0;
510 }
511 
512 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
513 {
514 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
515 						   tl_se_tpg);
516 	return tl_tpg->tl_fabric_prot_type;
517 }
518 
519 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
520 {
521 	return 1;
522 }
523 
524 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
525 {
526 	return 1;
527 }
528 
529 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
530 {
531 	return;
532 }
533 
534 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
535 {
536 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
537 			struct tcm_loop_cmd, tl_se_cmd);
538 
539 	return tl_cmd->sc_cmd_state;
540 }
541 
542 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
543 {
544 	/*
545 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
546 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
547 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
548 	 * format with transport_generic_map_mem_to_cmd().
549 	 *
550 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
551 	 * object execution queue.
552 	 */
553 	target_execute_cmd(se_cmd);
554 	return 0;
555 }
556 
557 static int tcm_loop_queue_data_or_status(const char *func,
558 		struct se_cmd *se_cmd, u8 scsi_status)
559 {
560 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
561 				struct tcm_loop_cmd, tl_se_cmd);
562 	struct scsi_cmnd *sc = tl_cmd->sc;
563 
564 	pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
565 		 func, sc, sc->cmnd[0]);
566 
567 	if (se_cmd->sense_buffer &&
568 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
569 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
570 
571 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
572 				SCSI_SENSE_BUFFERSIZE);
573 		sc->result = SAM_STAT_CHECK_CONDITION;
574 		set_driver_byte(sc, DRIVER_SENSE);
575 	} else
576 		sc->result = scsi_status;
577 
578 	set_host_byte(sc, DID_OK);
579 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
580 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
581 		scsi_set_resid(sc, se_cmd->residual_count);
582 	sc->scsi_done(sc);
583 	return 0;
584 }
585 
586 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
587 {
588 	return tcm_loop_queue_data_or_status(__func__, se_cmd, SAM_STAT_GOOD);
589 }
590 
591 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
592 {
593 	return tcm_loop_queue_data_or_status(__func__,
594 					     se_cmd, se_cmd->scsi_status);
595 }
596 
597 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
598 {
599 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
600 				struct tcm_loop_cmd, tl_se_cmd);
601 
602 	/* Wake up tcm_loop_issue_tmr(). */
603 	complete(&tl_cmd->tmr_done);
604 }
605 
606 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
607 {
608 	return;
609 }
610 
611 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
612 {
613 	switch (tl_hba->tl_proto_id) {
614 	case SCSI_PROTOCOL_SAS:
615 		return "SAS";
616 	case SCSI_PROTOCOL_FCP:
617 		return "FCP";
618 	case SCSI_PROTOCOL_ISCSI:
619 		return "iSCSI";
620 	default:
621 		break;
622 	}
623 
624 	return "Unknown";
625 }
626 
627 /* Start items for tcm_loop_port_cit */
628 
629 static int tcm_loop_port_link(
630 	struct se_portal_group *se_tpg,
631 	struct se_lun *lun)
632 {
633 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
634 				struct tcm_loop_tpg, tl_se_tpg);
635 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
636 
637 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
638 	/*
639 	 * Add Linux/SCSI struct scsi_device by HCTL
640 	 */
641 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
642 
643 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
644 	return 0;
645 }
646 
647 static void tcm_loop_port_unlink(
648 	struct se_portal_group *se_tpg,
649 	struct se_lun *se_lun)
650 {
651 	struct scsi_device *sd;
652 	struct tcm_loop_hba *tl_hba;
653 	struct tcm_loop_tpg *tl_tpg;
654 
655 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
656 	tl_hba = tl_tpg->tl_hba;
657 
658 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
659 				se_lun->unpacked_lun);
660 	if (!sd) {
661 		pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
662 		       0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
663 		return;
664 	}
665 	/*
666 	 * Remove Linux/SCSI struct scsi_device by HCTL
667 	 */
668 	scsi_remove_device(sd);
669 	scsi_device_put(sd);
670 
671 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
672 
673 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
674 }
675 
676 /* End items for tcm_loop_port_cit */
677 
678 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
679 		struct config_item *item, char *page)
680 {
681 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
682 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
683 						   tl_se_tpg);
684 
685 	return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
686 }
687 
688 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
689 		struct config_item *item, const char *page, size_t count)
690 {
691 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
692 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
693 						   tl_se_tpg);
694 	unsigned long val;
695 	int ret = kstrtoul(page, 0, &val);
696 
697 	if (ret) {
698 		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
699 		return ret;
700 	}
701 	if (val != 0 && val != 1 && val != 3) {
702 		pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
703 		return -EINVAL;
704 	}
705 	tl_tpg->tl_fabric_prot_type = val;
706 
707 	return count;
708 }
709 
710 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
711 
712 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
713 	&tcm_loop_tpg_attrib_attr_fabric_prot_type,
714 	NULL,
715 };
716 
717 /* Start items for tcm_loop_nexus_cit */
718 
719 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
720 				  struct se_session *se_sess, void *p)
721 {
722 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
723 					struct tcm_loop_tpg, tl_se_tpg);
724 
725 	tl_tpg->tl_nexus = p;
726 	return 0;
727 }
728 
729 static int tcm_loop_make_nexus(
730 	struct tcm_loop_tpg *tl_tpg,
731 	const char *name)
732 {
733 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
734 	struct tcm_loop_nexus *tl_nexus;
735 	int ret;
736 
737 	if (tl_tpg->tl_nexus) {
738 		pr_debug("tl_tpg->tl_nexus already exists\n");
739 		return -EEXIST;
740 	}
741 
742 	tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
743 	if (!tl_nexus)
744 		return -ENOMEM;
745 
746 	tl_nexus->se_sess = target_setup_session(&tl_tpg->tl_se_tpg, 0, 0,
747 					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
748 					name, tl_nexus, tcm_loop_alloc_sess_cb);
749 	if (IS_ERR(tl_nexus->se_sess)) {
750 		ret = PTR_ERR(tl_nexus->se_sess);
751 		kfree(tl_nexus);
752 		return ret;
753 	}
754 
755 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
756 		 tcm_loop_dump_proto_id(tl_hba), name);
757 	return 0;
758 }
759 
760 static int tcm_loop_drop_nexus(
761 	struct tcm_loop_tpg *tpg)
762 {
763 	struct se_session *se_sess;
764 	struct tcm_loop_nexus *tl_nexus;
765 
766 	tl_nexus = tpg->tl_nexus;
767 	if (!tl_nexus)
768 		return -ENODEV;
769 
770 	se_sess = tl_nexus->se_sess;
771 	if (!se_sess)
772 		return -ENODEV;
773 
774 	if (atomic_read(&tpg->tl_tpg_port_count)) {
775 		pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
776 		       atomic_read(&tpg->tl_tpg_port_count));
777 		return -EPERM;
778 	}
779 
780 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
781 		 tcm_loop_dump_proto_id(tpg->tl_hba),
782 		 tl_nexus->se_sess->se_node_acl->initiatorname);
783 	/*
784 	 * Release the SCSI I_T Nexus to the emulated Target Port
785 	 */
786 	target_remove_session(se_sess);
787 	tpg->tl_nexus = NULL;
788 	kfree(tl_nexus);
789 	return 0;
790 }
791 
792 /* End items for tcm_loop_nexus_cit */
793 
794 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
795 {
796 	struct se_portal_group *se_tpg = to_tpg(item);
797 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
798 			struct tcm_loop_tpg, tl_se_tpg);
799 	struct tcm_loop_nexus *tl_nexus;
800 	ssize_t ret;
801 
802 	tl_nexus = tl_tpg->tl_nexus;
803 	if (!tl_nexus)
804 		return -ENODEV;
805 
806 	ret = snprintf(page, PAGE_SIZE, "%s\n",
807 		tl_nexus->se_sess->se_node_acl->initiatorname);
808 
809 	return ret;
810 }
811 
812 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
813 		const char *page, size_t count)
814 {
815 	struct se_portal_group *se_tpg = to_tpg(item);
816 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
817 			struct tcm_loop_tpg, tl_se_tpg);
818 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
819 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
820 	int ret;
821 	/*
822 	 * Shutdown the active I_T nexus if 'NULL' is passed..
823 	 */
824 	if (!strncmp(page, "NULL", 4)) {
825 		ret = tcm_loop_drop_nexus(tl_tpg);
826 		return (!ret) ? count : ret;
827 	}
828 	/*
829 	 * Otherwise make sure the passed virtual Initiator port WWN matches
830 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
831 	 * tcm_loop_make_nexus()
832 	 */
833 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
834 		pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
835 		       page, TL_WWN_ADDR_LEN);
836 		return -EINVAL;
837 	}
838 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
839 
840 	ptr = strstr(i_port, "naa.");
841 	if (ptr) {
842 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
843 			pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
844 			       i_port, tcm_loop_dump_proto_id(tl_hba));
845 			return -EINVAL;
846 		}
847 		port_ptr = &i_port[0];
848 		goto check_newline;
849 	}
850 	ptr = strstr(i_port, "fc.");
851 	if (ptr) {
852 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
853 			pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
854 			       i_port, tcm_loop_dump_proto_id(tl_hba));
855 			return -EINVAL;
856 		}
857 		port_ptr = &i_port[3]; /* Skip over "fc." */
858 		goto check_newline;
859 	}
860 	ptr = strstr(i_port, "iqn.");
861 	if (ptr) {
862 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
863 			pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
864 			       i_port, tcm_loop_dump_proto_id(tl_hba));
865 			return -EINVAL;
866 		}
867 		port_ptr = &i_port[0];
868 		goto check_newline;
869 	}
870 	pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
871 	       i_port);
872 	return -EINVAL;
873 	/*
874 	 * Clear any trailing newline for the NAA WWN
875 	 */
876 check_newline:
877 	if (i_port[strlen(i_port)-1] == '\n')
878 		i_port[strlen(i_port)-1] = '\0';
879 
880 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
881 	if (ret < 0)
882 		return ret;
883 
884 	return count;
885 }
886 
887 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
888 		char *page)
889 {
890 	struct se_portal_group *se_tpg = to_tpg(item);
891 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
892 			struct tcm_loop_tpg, tl_se_tpg);
893 	const char *status = NULL;
894 	ssize_t ret = -EINVAL;
895 
896 	switch (tl_tpg->tl_transport_status) {
897 	case TCM_TRANSPORT_ONLINE:
898 		status = "online";
899 		break;
900 	case TCM_TRANSPORT_OFFLINE:
901 		status = "offline";
902 		break;
903 	default:
904 		break;
905 	}
906 
907 	if (status)
908 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
909 
910 	return ret;
911 }
912 
913 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
914 		const char *page, size_t count)
915 {
916 	struct se_portal_group *se_tpg = to_tpg(item);
917 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
918 			struct tcm_loop_tpg, tl_se_tpg);
919 
920 	if (!strncmp(page, "online", 6)) {
921 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
922 		return count;
923 	}
924 	if (!strncmp(page, "offline", 7)) {
925 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
926 		if (tl_tpg->tl_nexus) {
927 			struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
928 
929 			core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
930 		}
931 		return count;
932 	}
933 	return -EINVAL;
934 }
935 
936 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
937 					 char *page)
938 {
939 	struct se_portal_group *se_tpg = to_tpg(item);
940 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
941 			struct tcm_loop_tpg, tl_se_tpg);
942 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
943 
944 	return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
945 			tl_hba->sh->host_no, tl_tpg->tl_tpgt);
946 }
947 
948 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
949 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
950 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
951 
952 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
953 	&tcm_loop_tpg_attr_nexus,
954 	&tcm_loop_tpg_attr_transport_status,
955 	&tcm_loop_tpg_attr_address,
956 	NULL,
957 };
958 
959 /* Start items for tcm_loop_naa_cit */
960 
961 static struct se_portal_group *tcm_loop_make_naa_tpg(struct se_wwn *wwn,
962 						     const char *name)
963 {
964 	struct tcm_loop_hba *tl_hba = container_of(wwn,
965 			struct tcm_loop_hba, tl_hba_wwn);
966 	struct tcm_loop_tpg *tl_tpg;
967 	int ret;
968 	unsigned long tpgt;
969 
970 	if (strstr(name, "tpgt_") != name) {
971 		pr_err("Unable to locate \"tpgt_#\" directory group\n");
972 		return ERR_PTR(-EINVAL);
973 	}
974 	if (kstrtoul(name+5, 10, &tpgt))
975 		return ERR_PTR(-EINVAL);
976 
977 	if (tpgt >= TL_TPGS_PER_HBA) {
978 		pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
979 		       tpgt, TL_TPGS_PER_HBA);
980 		return ERR_PTR(-EINVAL);
981 	}
982 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
983 	tl_tpg->tl_hba = tl_hba;
984 	tl_tpg->tl_tpgt = tpgt;
985 	/*
986 	 * Register the tl_tpg as a emulated TCM Target Endpoint
987 	 */
988 	ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
989 	if (ret < 0)
990 		return ERR_PTR(-ENOMEM);
991 
992 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
993 		 tcm_loop_dump_proto_id(tl_hba),
994 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
995 	return &tl_tpg->tl_se_tpg;
996 }
997 
998 static void tcm_loop_drop_naa_tpg(
999 	struct se_portal_group *se_tpg)
1000 {
1001 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1002 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1003 				struct tcm_loop_tpg, tl_se_tpg);
1004 	struct tcm_loop_hba *tl_hba;
1005 	unsigned short tpgt;
1006 
1007 	tl_hba = tl_tpg->tl_hba;
1008 	tpgt = tl_tpg->tl_tpgt;
1009 	/*
1010 	 * Release the I_T Nexus for the Virtual target link if present
1011 	 */
1012 	tcm_loop_drop_nexus(tl_tpg);
1013 	/*
1014 	 * Deregister the tl_tpg as a emulated TCM Target Endpoint
1015 	 */
1016 	core_tpg_deregister(se_tpg);
1017 
1018 	tl_tpg->tl_hba = NULL;
1019 	tl_tpg->tl_tpgt = 0;
1020 
1021 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
1022 		 tcm_loop_dump_proto_id(tl_hba),
1023 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1024 }
1025 
1026 /* End items for tcm_loop_naa_cit */
1027 
1028 /* Start items for tcm_loop_cit */
1029 
1030 static struct se_wwn *tcm_loop_make_scsi_hba(
1031 	struct target_fabric_configfs *tf,
1032 	struct config_group *group,
1033 	const char *name)
1034 {
1035 	struct tcm_loop_hba *tl_hba;
1036 	struct Scsi_Host *sh;
1037 	char *ptr;
1038 	int ret, off = 0;
1039 
1040 	tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
1041 	if (!tl_hba)
1042 		return ERR_PTR(-ENOMEM);
1043 
1044 	/*
1045 	 * Determine the emulated Protocol Identifier and Target Port Name
1046 	 * based on the incoming configfs directory name.
1047 	 */
1048 	ptr = strstr(name, "naa.");
1049 	if (ptr) {
1050 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1051 		goto check_len;
1052 	}
1053 	ptr = strstr(name, "fc.");
1054 	if (ptr) {
1055 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1056 		off = 3; /* Skip over "fc." */
1057 		goto check_len;
1058 	}
1059 	ptr = strstr(name, "iqn.");
1060 	if (!ptr) {
1061 		pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1062 		       name);
1063 		ret = -EINVAL;
1064 		goto out;
1065 	}
1066 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1067 
1068 check_len:
1069 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1070 		pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1071 		       name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1072 		ret = -EINVAL;
1073 		goto out;
1074 	}
1075 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1076 
1077 	/*
1078 	 * Call device_register(tl_hba->dev) to register the emulated
1079 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1080 	 * device_register() callbacks in tcm_loop_driver_probe()
1081 	 */
1082 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1083 	if (ret)
1084 		goto out;
1085 
1086 	sh = tl_hba->sh;
1087 	tcm_loop_hba_no_cnt++;
1088 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1089 		 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1090 	return &tl_hba->tl_hba_wwn;
1091 out:
1092 	kfree(tl_hba);
1093 	return ERR_PTR(ret);
1094 }
1095 
1096 static void tcm_loop_drop_scsi_hba(
1097 	struct se_wwn *wwn)
1098 {
1099 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1100 				struct tcm_loop_hba, tl_hba_wwn);
1101 
1102 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1103 		 tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1104 		 tl_hba->sh->host_no);
1105 	/*
1106 	 * Call device_unregister() on the original tl_hba->dev.
1107 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1108 	 * release *tl_hba;
1109 	 */
1110 	device_unregister(&tl_hba->dev);
1111 }
1112 
1113 /* Start items for tcm_loop_cit */
1114 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1115 {
1116 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1117 }
1118 
1119 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1120 
1121 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1122 	&tcm_loop_wwn_attr_version,
1123 	NULL,
1124 };
1125 
1126 /* End items for tcm_loop_cit */
1127 
1128 static const struct target_core_fabric_ops loop_ops = {
1129 	.module				= THIS_MODULE,
1130 	.fabric_name			= "loopback",
1131 	.tpg_get_wwn			= tcm_loop_get_endpoint_wwn,
1132 	.tpg_get_tag			= tcm_loop_get_tag,
1133 	.tpg_check_demo_mode		= tcm_loop_check_demo_mode,
1134 	.tpg_check_demo_mode_cache	= tcm_loop_check_demo_mode_cache,
1135 	.tpg_check_demo_mode_write_protect =
1136 				tcm_loop_check_demo_mode_write_protect,
1137 	.tpg_check_prod_mode_write_protect =
1138 				tcm_loop_check_prod_mode_write_protect,
1139 	.tpg_check_prot_fabric_only	= tcm_loop_check_prot_fabric_only,
1140 	.tpg_get_inst_index		= tcm_loop_get_inst_index,
1141 	.check_stop_free		= tcm_loop_check_stop_free,
1142 	.release_cmd			= tcm_loop_release_cmd,
1143 	.sess_get_index			= tcm_loop_sess_get_index,
1144 	.write_pending			= tcm_loop_write_pending,
1145 	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
1146 	.get_cmd_state			= tcm_loop_get_cmd_state,
1147 	.queue_data_in			= tcm_loop_queue_data_in,
1148 	.queue_status			= tcm_loop_queue_status,
1149 	.queue_tm_rsp			= tcm_loop_queue_tm_rsp,
1150 	.aborted_task			= tcm_loop_aborted_task,
1151 	.fabric_make_wwn		= tcm_loop_make_scsi_hba,
1152 	.fabric_drop_wwn		= tcm_loop_drop_scsi_hba,
1153 	.fabric_make_tpg		= tcm_loop_make_naa_tpg,
1154 	.fabric_drop_tpg		= tcm_loop_drop_naa_tpg,
1155 	.fabric_post_link		= tcm_loop_port_link,
1156 	.fabric_pre_unlink		= tcm_loop_port_unlink,
1157 	.tfc_wwn_attrs			= tcm_loop_wwn_attrs,
1158 	.tfc_tpg_base_attrs		= tcm_loop_tpg_attrs,
1159 	.tfc_tpg_attrib_attrs		= tcm_loop_tpg_attrib_attrs,
1160 };
1161 
1162 static int __init tcm_loop_fabric_init(void)
1163 {
1164 	int ret = -ENOMEM;
1165 
1166 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1167 	if (!tcm_loop_workqueue)
1168 		goto out;
1169 
1170 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1171 				sizeof(struct tcm_loop_cmd),
1172 				__alignof__(struct tcm_loop_cmd),
1173 				0, NULL);
1174 	if (!tcm_loop_cmd_cache) {
1175 		pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1176 		goto out_destroy_workqueue;
1177 	}
1178 
1179 	ret = tcm_loop_alloc_core_bus();
1180 	if (ret)
1181 		goto out_destroy_cache;
1182 
1183 	ret = target_register_template(&loop_ops);
1184 	if (ret)
1185 		goto out_release_core_bus;
1186 
1187 	return 0;
1188 
1189 out_release_core_bus:
1190 	tcm_loop_release_core_bus();
1191 out_destroy_cache:
1192 	kmem_cache_destroy(tcm_loop_cmd_cache);
1193 out_destroy_workqueue:
1194 	destroy_workqueue(tcm_loop_workqueue);
1195 out:
1196 	return ret;
1197 }
1198 
1199 static void __exit tcm_loop_fabric_exit(void)
1200 {
1201 	target_unregister_template(&loop_ops);
1202 	tcm_loop_release_core_bus();
1203 	kmem_cache_destroy(tcm_loop_cmd_cache);
1204 	destroy_workqueue(tcm_loop_workqueue);
1205 }
1206 
1207 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1208 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1209 MODULE_LICENSE("GPL");
1210 module_init(tcm_loop_fabric_init);
1211 module_exit(tcm_loop_fabric_exit);
1212