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