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