xref: /openbmc/linux/drivers/target/loopback/tcm_loop.c (revision 8631f940b81bf0da3d375fce166d381fa8c47bb2)
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 	if (scsi_bidi_cmnd(sc)) {
132 		struct scsi_data_buffer *sdb = scsi_in(sc);
133 
134 		sgl_bidi = sdb->table.sgl;
135 		sgl_bidi_count = sdb->table.nents;
136 		se_cmd->se_cmd_flags |= SCF_BIDI;
137 
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 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
154 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
155 			transfer_length, TCM_SIMPLE_TAG,
156 			sc->sc_data_direction, 0,
157 			scsi_sglist(sc), scsi_sg_count(sc),
158 			sgl_bidi, sgl_bidi_count,
159 			scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
160 	if (rc < 0) {
161 		set_host_byte(sc, DID_NO_CONNECT);
162 		goto out_done;
163 	}
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 int tcm_loop_slave_alloc(struct scsi_device *sd)
308 {
309 	blk_queue_flag_set(QUEUE_FLAG_BIDI, sd->request_queue);
310 	return 0;
311 }
312 
313 static struct scsi_host_template tcm_loop_driver_template = {
314 	.show_info		= tcm_loop_show_info,
315 	.proc_name		= "tcm_loopback",
316 	.name			= "TCM_Loopback",
317 	.queuecommand		= tcm_loop_queuecommand,
318 	.change_queue_depth	= scsi_change_queue_depth,
319 	.eh_abort_handler = tcm_loop_abort_task,
320 	.eh_device_reset_handler = tcm_loop_device_reset,
321 	.eh_target_reset_handler = tcm_loop_target_reset,
322 	.can_queue		= 1024,
323 	.this_id		= -1,
324 	.sg_tablesize		= 256,
325 	.cmd_per_lun		= 1024,
326 	.max_sectors		= 0xFFFF,
327 	.dma_boundary		= PAGE_SIZE - 1,
328 	.slave_alloc		= tcm_loop_slave_alloc,
329 	.module			= THIS_MODULE,
330 	.track_queue_depth	= 1,
331 };
332 
333 static int tcm_loop_driver_probe(struct device *dev)
334 {
335 	struct tcm_loop_hba *tl_hba;
336 	struct Scsi_Host *sh;
337 	int error, host_prot;
338 
339 	tl_hba = to_tcm_loop_hba(dev);
340 
341 	sh = scsi_host_alloc(&tcm_loop_driver_template,
342 			sizeof(struct tcm_loop_hba));
343 	if (!sh) {
344 		pr_err("Unable to allocate struct scsi_host\n");
345 		return -ENODEV;
346 	}
347 	tl_hba->sh = sh;
348 
349 	/*
350 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
351 	 */
352 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
353 	/*
354 	 * Setup single ID, Channel and LUN for now..
355 	 */
356 	sh->max_id = 2;
357 	sh->max_lun = 0;
358 	sh->max_channel = 0;
359 	sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
360 
361 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
362 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
363 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
364 
365 	scsi_host_set_prot(sh, host_prot);
366 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
367 
368 	error = scsi_add_host(sh, &tl_hba->dev);
369 	if (error) {
370 		pr_err("%s: scsi_add_host failed\n", __func__);
371 		scsi_host_put(sh);
372 		return -ENODEV;
373 	}
374 	return 0;
375 }
376 
377 static int tcm_loop_driver_remove(struct device *dev)
378 {
379 	struct tcm_loop_hba *tl_hba;
380 	struct Scsi_Host *sh;
381 
382 	tl_hba = to_tcm_loop_hba(dev);
383 	sh = tl_hba->sh;
384 
385 	scsi_remove_host(sh);
386 	scsi_host_put(sh);
387 	return 0;
388 }
389 
390 static void tcm_loop_release_adapter(struct device *dev)
391 {
392 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
393 
394 	kfree(tl_hba);
395 }
396 
397 /*
398  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
399  */
400 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
401 {
402 	int ret;
403 
404 	tl_hba->dev.bus = &tcm_loop_lld_bus;
405 	tl_hba->dev.parent = tcm_loop_primary;
406 	tl_hba->dev.release = &tcm_loop_release_adapter;
407 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
408 
409 	ret = device_register(&tl_hba->dev);
410 	if (ret) {
411 		pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
412 		return -ENODEV;
413 	}
414 
415 	return 0;
416 }
417 
418 /*
419  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
420  * tcm_loop SCSI bus.
421  */
422 static int tcm_loop_alloc_core_bus(void)
423 {
424 	int ret;
425 
426 	tcm_loop_primary = root_device_register("tcm_loop_0");
427 	if (IS_ERR(tcm_loop_primary)) {
428 		pr_err("Unable to allocate tcm_loop_primary\n");
429 		return PTR_ERR(tcm_loop_primary);
430 	}
431 
432 	ret = bus_register(&tcm_loop_lld_bus);
433 	if (ret) {
434 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
435 		goto dev_unreg;
436 	}
437 
438 	ret = driver_register(&tcm_loop_driverfs);
439 	if (ret) {
440 		pr_err("driver_register() failed for tcm_loop_driverfs\n");
441 		goto bus_unreg;
442 	}
443 
444 	pr_debug("Initialized TCM Loop Core Bus\n");
445 	return ret;
446 
447 bus_unreg:
448 	bus_unregister(&tcm_loop_lld_bus);
449 dev_unreg:
450 	root_device_unregister(tcm_loop_primary);
451 	return ret;
452 }
453 
454 static void tcm_loop_release_core_bus(void)
455 {
456 	driver_unregister(&tcm_loop_driverfs);
457 	bus_unregister(&tcm_loop_lld_bus);
458 	root_device_unregister(tcm_loop_primary);
459 
460 	pr_debug("Releasing TCM Loop Core BUS\n");
461 }
462 
463 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
464 {
465 	return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
466 }
467 
468 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
469 {
470 	/*
471 	 * Return the passed NAA identifier for the Target Port
472 	 */
473 	return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
474 }
475 
476 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
477 {
478 	/*
479 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
480 	 * to represent the SCSI Target Port.
481 	 */
482 	return tl_tpg(se_tpg)->tl_tpgt;
483 }
484 
485 /*
486  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
487  * based upon the incoming fabric dependent SCSI Initiator Port
488  */
489 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
490 {
491 	return 1;
492 }
493 
494 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
495 {
496 	return 0;
497 }
498 
499 /*
500  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
501  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
502  */
503 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
504 {
505 	return 0;
506 }
507 
508 /*
509  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
510  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
511  * It has been added here as a nop for target_fabric_tf_ops_check()
512  */
513 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
514 {
515 	return 0;
516 }
517 
518 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
519 {
520 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
521 						   tl_se_tpg);
522 	return tl_tpg->tl_fabric_prot_type;
523 }
524 
525 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
526 {
527 	return 1;
528 }
529 
530 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
531 {
532 	return 1;
533 }
534 
535 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
536 {
537 	return;
538 }
539 
540 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
541 {
542 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
543 			struct tcm_loop_cmd, tl_se_cmd);
544 
545 	return tl_cmd->sc_cmd_state;
546 }
547 
548 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
549 {
550 	/*
551 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
552 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
553 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
554 	 * format with transport_generic_map_mem_to_cmd().
555 	 *
556 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
557 	 * object execution queue.
558 	 */
559 	target_execute_cmd(se_cmd);
560 	return 0;
561 }
562 
563 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
564 {
565 	return 0;
566 }
567 
568 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
569 {
570 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
571 				struct tcm_loop_cmd, tl_se_cmd);
572 	struct scsi_cmnd *sc = tl_cmd->sc;
573 
574 	pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
575 		 __func__, sc, sc->cmnd[0]);
576 
577 	sc->result = SAM_STAT_GOOD;
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_status(struct se_cmd *se_cmd)
587 {
588 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
589 				struct tcm_loop_cmd, tl_se_cmd);
590 	struct scsi_cmnd *sc = tl_cmd->sc;
591 
592 	pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
593 		 __func__, sc, sc->cmnd[0]);
594 
595 	if (se_cmd->sense_buffer &&
596 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
597 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
598 
599 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
600 				SCSI_SENSE_BUFFERSIZE);
601 		sc->result = SAM_STAT_CHECK_CONDITION;
602 		set_driver_byte(sc, DRIVER_SENSE);
603 	} else
604 		sc->result = se_cmd->scsi_status;
605 
606 	set_host_byte(sc, DID_OK);
607 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
608 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
609 		scsi_set_resid(sc, se_cmd->residual_count);
610 	sc->scsi_done(sc);
611 	return 0;
612 }
613 
614 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
615 {
616 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
617 				struct tcm_loop_cmd, tl_se_cmd);
618 
619 	/* Wake up tcm_loop_issue_tmr(). */
620 	complete(&tl_cmd->tmr_done);
621 }
622 
623 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
624 {
625 	return;
626 }
627 
628 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
629 {
630 	switch (tl_hba->tl_proto_id) {
631 	case SCSI_PROTOCOL_SAS:
632 		return "SAS";
633 	case SCSI_PROTOCOL_FCP:
634 		return "FCP";
635 	case SCSI_PROTOCOL_ISCSI:
636 		return "iSCSI";
637 	default:
638 		break;
639 	}
640 
641 	return "Unknown";
642 }
643 
644 /* Start items for tcm_loop_port_cit */
645 
646 static int tcm_loop_port_link(
647 	struct se_portal_group *se_tpg,
648 	struct se_lun *lun)
649 {
650 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
651 				struct tcm_loop_tpg, tl_se_tpg);
652 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
653 
654 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
655 	/*
656 	 * Add Linux/SCSI struct scsi_device by HCTL
657 	 */
658 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
659 
660 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
661 	return 0;
662 }
663 
664 static void tcm_loop_port_unlink(
665 	struct se_portal_group *se_tpg,
666 	struct se_lun *se_lun)
667 {
668 	struct scsi_device *sd;
669 	struct tcm_loop_hba *tl_hba;
670 	struct tcm_loop_tpg *tl_tpg;
671 
672 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
673 	tl_hba = tl_tpg->tl_hba;
674 
675 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
676 				se_lun->unpacked_lun);
677 	if (!sd) {
678 		pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
679 		       0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
680 		return;
681 	}
682 	/*
683 	 * Remove Linux/SCSI struct scsi_device by HCTL
684 	 */
685 	scsi_remove_device(sd);
686 	scsi_device_put(sd);
687 
688 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
689 
690 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
691 }
692 
693 /* End items for tcm_loop_port_cit */
694 
695 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
696 		struct config_item *item, char *page)
697 {
698 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
699 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
700 						   tl_se_tpg);
701 
702 	return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
703 }
704 
705 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
706 		struct config_item *item, const char *page, size_t count)
707 {
708 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
709 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
710 						   tl_se_tpg);
711 	unsigned long val;
712 	int ret = kstrtoul(page, 0, &val);
713 
714 	if (ret) {
715 		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
716 		return ret;
717 	}
718 	if (val != 0 && val != 1 && val != 3) {
719 		pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
720 		return -EINVAL;
721 	}
722 	tl_tpg->tl_fabric_prot_type = val;
723 
724 	return count;
725 }
726 
727 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
728 
729 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
730 	&tcm_loop_tpg_attrib_attr_fabric_prot_type,
731 	NULL,
732 };
733 
734 /* Start items for tcm_loop_nexus_cit */
735 
736 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
737 				  struct se_session *se_sess, void *p)
738 {
739 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
740 					struct tcm_loop_tpg, tl_se_tpg);
741 
742 	tl_tpg->tl_nexus = p;
743 	return 0;
744 }
745 
746 static int tcm_loop_make_nexus(
747 	struct tcm_loop_tpg *tl_tpg,
748 	const char *name)
749 {
750 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
751 	struct tcm_loop_nexus *tl_nexus;
752 	int ret;
753 
754 	if (tl_tpg->tl_nexus) {
755 		pr_debug("tl_tpg->tl_nexus already exists\n");
756 		return -EEXIST;
757 	}
758 
759 	tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
760 	if (!tl_nexus)
761 		return -ENOMEM;
762 
763 	tl_nexus->se_sess = target_setup_session(&tl_tpg->tl_se_tpg, 0, 0,
764 					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
765 					name, tl_nexus, tcm_loop_alloc_sess_cb);
766 	if (IS_ERR(tl_nexus->se_sess)) {
767 		ret = PTR_ERR(tl_nexus->se_sess);
768 		kfree(tl_nexus);
769 		return ret;
770 	}
771 
772 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
773 		 tcm_loop_dump_proto_id(tl_hba), name);
774 	return 0;
775 }
776 
777 static int tcm_loop_drop_nexus(
778 	struct tcm_loop_tpg *tpg)
779 {
780 	struct se_session *se_sess;
781 	struct tcm_loop_nexus *tl_nexus;
782 
783 	tl_nexus = tpg->tl_nexus;
784 	if (!tl_nexus)
785 		return -ENODEV;
786 
787 	se_sess = tl_nexus->se_sess;
788 	if (!se_sess)
789 		return -ENODEV;
790 
791 	if (atomic_read(&tpg->tl_tpg_port_count)) {
792 		pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
793 		       atomic_read(&tpg->tl_tpg_port_count));
794 		return -EPERM;
795 	}
796 
797 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
798 		 tcm_loop_dump_proto_id(tpg->tl_hba),
799 		 tl_nexus->se_sess->se_node_acl->initiatorname);
800 	/*
801 	 * Release the SCSI I_T Nexus to the emulated Target Port
802 	 */
803 	target_remove_session(se_sess);
804 	tpg->tl_nexus = NULL;
805 	kfree(tl_nexus);
806 	return 0;
807 }
808 
809 /* End items for tcm_loop_nexus_cit */
810 
811 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
812 {
813 	struct se_portal_group *se_tpg = to_tpg(item);
814 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
815 			struct tcm_loop_tpg, tl_se_tpg);
816 	struct tcm_loop_nexus *tl_nexus;
817 	ssize_t ret;
818 
819 	tl_nexus = tl_tpg->tl_nexus;
820 	if (!tl_nexus)
821 		return -ENODEV;
822 
823 	ret = snprintf(page, PAGE_SIZE, "%s\n",
824 		tl_nexus->se_sess->se_node_acl->initiatorname);
825 
826 	return ret;
827 }
828 
829 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
830 		const char *page, size_t count)
831 {
832 	struct se_portal_group *se_tpg = to_tpg(item);
833 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
834 			struct tcm_loop_tpg, tl_se_tpg);
835 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
836 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
837 	int ret;
838 	/*
839 	 * Shutdown the active I_T nexus if 'NULL' is passed..
840 	 */
841 	if (!strncmp(page, "NULL", 4)) {
842 		ret = tcm_loop_drop_nexus(tl_tpg);
843 		return (!ret) ? count : ret;
844 	}
845 	/*
846 	 * Otherwise make sure the passed virtual Initiator port WWN matches
847 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
848 	 * tcm_loop_make_nexus()
849 	 */
850 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
851 		pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
852 		       page, TL_WWN_ADDR_LEN);
853 		return -EINVAL;
854 	}
855 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
856 
857 	ptr = strstr(i_port, "naa.");
858 	if (ptr) {
859 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
860 			pr_err("Passed SAS 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 	ptr = strstr(i_port, "fc.");
868 	if (ptr) {
869 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
870 			pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
871 			       i_port, tcm_loop_dump_proto_id(tl_hba));
872 			return -EINVAL;
873 		}
874 		port_ptr = &i_port[3]; /* Skip over "fc." */
875 		goto check_newline;
876 	}
877 	ptr = strstr(i_port, "iqn.");
878 	if (ptr) {
879 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
880 			pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
881 			       i_port, tcm_loop_dump_proto_id(tl_hba));
882 			return -EINVAL;
883 		}
884 		port_ptr = &i_port[0];
885 		goto check_newline;
886 	}
887 	pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
888 	       i_port);
889 	return -EINVAL;
890 	/*
891 	 * Clear any trailing newline for the NAA WWN
892 	 */
893 check_newline:
894 	if (i_port[strlen(i_port)-1] == '\n')
895 		i_port[strlen(i_port)-1] = '\0';
896 
897 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
898 	if (ret < 0)
899 		return ret;
900 
901 	return count;
902 }
903 
904 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
905 		char *page)
906 {
907 	struct se_portal_group *se_tpg = to_tpg(item);
908 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
909 			struct tcm_loop_tpg, tl_se_tpg);
910 	const char *status = NULL;
911 	ssize_t ret = -EINVAL;
912 
913 	switch (tl_tpg->tl_transport_status) {
914 	case TCM_TRANSPORT_ONLINE:
915 		status = "online";
916 		break;
917 	case TCM_TRANSPORT_OFFLINE:
918 		status = "offline";
919 		break;
920 	default:
921 		break;
922 	}
923 
924 	if (status)
925 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
926 
927 	return ret;
928 }
929 
930 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
931 		const char *page, size_t count)
932 {
933 	struct se_portal_group *se_tpg = to_tpg(item);
934 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
935 			struct tcm_loop_tpg, tl_se_tpg);
936 
937 	if (!strncmp(page, "online", 6)) {
938 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
939 		return count;
940 	}
941 	if (!strncmp(page, "offline", 7)) {
942 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
943 		if (tl_tpg->tl_nexus) {
944 			struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
945 
946 			core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
947 		}
948 		return count;
949 	}
950 	return -EINVAL;
951 }
952 
953 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
954 					 char *page)
955 {
956 	struct se_portal_group *se_tpg = to_tpg(item);
957 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
958 			struct tcm_loop_tpg, tl_se_tpg);
959 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
960 
961 	return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
962 			tl_hba->sh->host_no, tl_tpg->tl_tpgt);
963 }
964 
965 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
966 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
967 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
968 
969 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
970 	&tcm_loop_tpg_attr_nexus,
971 	&tcm_loop_tpg_attr_transport_status,
972 	&tcm_loop_tpg_attr_address,
973 	NULL,
974 };
975 
976 /* Start items for tcm_loop_naa_cit */
977 
978 static struct se_portal_group *tcm_loop_make_naa_tpg(struct se_wwn *wwn,
979 						     const char *name)
980 {
981 	struct tcm_loop_hba *tl_hba = container_of(wwn,
982 			struct tcm_loop_hba, tl_hba_wwn);
983 	struct tcm_loop_tpg *tl_tpg;
984 	int ret;
985 	unsigned long tpgt;
986 
987 	if (strstr(name, "tpgt_") != name) {
988 		pr_err("Unable to locate \"tpgt_#\" directory group\n");
989 		return ERR_PTR(-EINVAL);
990 	}
991 	if (kstrtoul(name+5, 10, &tpgt))
992 		return ERR_PTR(-EINVAL);
993 
994 	if (tpgt >= TL_TPGS_PER_HBA) {
995 		pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
996 		       tpgt, TL_TPGS_PER_HBA);
997 		return ERR_PTR(-EINVAL);
998 	}
999 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1000 	tl_tpg->tl_hba = tl_hba;
1001 	tl_tpg->tl_tpgt = tpgt;
1002 	/*
1003 	 * Register the tl_tpg as a emulated TCM Target Endpoint
1004 	 */
1005 	ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
1006 	if (ret < 0)
1007 		return ERR_PTR(-ENOMEM);
1008 
1009 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
1010 		 tcm_loop_dump_proto_id(tl_hba),
1011 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1012 	return &tl_tpg->tl_se_tpg;
1013 }
1014 
1015 static void tcm_loop_drop_naa_tpg(
1016 	struct se_portal_group *se_tpg)
1017 {
1018 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1019 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1020 				struct tcm_loop_tpg, tl_se_tpg);
1021 	struct tcm_loop_hba *tl_hba;
1022 	unsigned short tpgt;
1023 
1024 	tl_hba = tl_tpg->tl_hba;
1025 	tpgt = tl_tpg->tl_tpgt;
1026 	/*
1027 	 * Release the I_T Nexus for the Virtual target link if present
1028 	 */
1029 	tcm_loop_drop_nexus(tl_tpg);
1030 	/*
1031 	 * Deregister the tl_tpg as a emulated TCM Target Endpoint
1032 	 */
1033 	core_tpg_deregister(se_tpg);
1034 
1035 	tl_tpg->tl_hba = NULL;
1036 	tl_tpg->tl_tpgt = 0;
1037 
1038 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
1039 		 tcm_loop_dump_proto_id(tl_hba),
1040 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1041 }
1042 
1043 /* End items for tcm_loop_naa_cit */
1044 
1045 /* Start items for tcm_loop_cit */
1046 
1047 static struct se_wwn *tcm_loop_make_scsi_hba(
1048 	struct target_fabric_configfs *tf,
1049 	struct config_group *group,
1050 	const char *name)
1051 {
1052 	struct tcm_loop_hba *tl_hba;
1053 	struct Scsi_Host *sh;
1054 	char *ptr;
1055 	int ret, off = 0;
1056 
1057 	tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
1058 	if (!tl_hba)
1059 		return ERR_PTR(-ENOMEM);
1060 
1061 	/*
1062 	 * Determine the emulated Protocol Identifier and Target Port Name
1063 	 * based on the incoming configfs directory name.
1064 	 */
1065 	ptr = strstr(name, "naa.");
1066 	if (ptr) {
1067 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1068 		goto check_len;
1069 	}
1070 	ptr = strstr(name, "fc.");
1071 	if (ptr) {
1072 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1073 		off = 3; /* Skip over "fc." */
1074 		goto check_len;
1075 	}
1076 	ptr = strstr(name, "iqn.");
1077 	if (!ptr) {
1078 		pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1079 		       name);
1080 		ret = -EINVAL;
1081 		goto out;
1082 	}
1083 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1084 
1085 check_len:
1086 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1087 		pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1088 		       name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1089 		ret = -EINVAL;
1090 		goto out;
1091 	}
1092 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1093 
1094 	/*
1095 	 * Call device_register(tl_hba->dev) to register the emulated
1096 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1097 	 * device_register() callbacks in tcm_loop_driver_probe()
1098 	 */
1099 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1100 	if (ret)
1101 		goto out;
1102 
1103 	sh = tl_hba->sh;
1104 	tcm_loop_hba_no_cnt++;
1105 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1106 		 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1107 	return &tl_hba->tl_hba_wwn;
1108 out:
1109 	kfree(tl_hba);
1110 	return ERR_PTR(ret);
1111 }
1112 
1113 static void tcm_loop_drop_scsi_hba(
1114 	struct se_wwn *wwn)
1115 {
1116 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1117 				struct tcm_loop_hba, tl_hba_wwn);
1118 
1119 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1120 		 tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1121 		 tl_hba->sh->host_no);
1122 	/*
1123 	 * Call device_unregister() on the original tl_hba->dev.
1124 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1125 	 * release *tl_hba;
1126 	 */
1127 	device_unregister(&tl_hba->dev);
1128 }
1129 
1130 /* Start items for tcm_loop_cit */
1131 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1132 {
1133 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1134 }
1135 
1136 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1137 
1138 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1139 	&tcm_loop_wwn_attr_version,
1140 	NULL,
1141 };
1142 
1143 /* End items for tcm_loop_cit */
1144 
1145 static const struct target_core_fabric_ops loop_ops = {
1146 	.module				= THIS_MODULE,
1147 	.fabric_name			= "loopback",
1148 	.tpg_get_wwn			= tcm_loop_get_endpoint_wwn,
1149 	.tpg_get_tag			= tcm_loop_get_tag,
1150 	.tpg_check_demo_mode		= tcm_loop_check_demo_mode,
1151 	.tpg_check_demo_mode_cache	= tcm_loop_check_demo_mode_cache,
1152 	.tpg_check_demo_mode_write_protect =
1153 				tcm_loop_check_demo_mode_write_protect,
1154 	.tpg_check_prod_mode_write_protect =
1155 				tcm_loop_check_prod_mode_write_protect,
1156 	.tpg_check_prot_fabric_only	= tcm_loop_check_prot_fabric_only,
1157 	.tpg_get_inst_index		= tcm_loop_get_inst_index,
1158 	.check_stop_free		= tcm_loop_check_stop_free,
1159 	.release_cmd			= tcm_loop_release_cmd,
1160 	.sess_get_index			= tcm_loop_sess_get_index,
1161 	.write_pending			= tcm_loop_write_pending,
1162 	.write_pending_status		= tcm_loop_write_pending_status,
1163 	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
1164 	.get_cmd_state			= tcm_loop_get_cmd_state,
1165 	.queue_data_in			= tcm_loop_queue_data_in,
1166 	.queue_status			= tcm_loop_queue_status,
1167 	.queue_tm_rsp			= tcm_loop_queue_tm_rsp,
1168 	.aborted_task			= tcm_loop_aborted_task,
1169 	.fabric_make_wwn		= tcm_loop_make_scsi_hba,
1170 	.fabric_drop_wwn		= tcm_loop_drop_scsi_hba,
1171 	.fabric_make_tpg		= tcm_loop_make_naa_tpg,
1172 	.fabric_drop_tpg		= tcm_loop_drop_naa_tpg,
1173 	.fabric_post_link		= tcm_loop_port_link,
1174 	.fabric_pre_unlink		= tcm_loop_port_unlink,
1175 	.tfc_wwn_attrs			= tcm_loop_wwn_attrs,
1176 	.tfc_tpg_base_attrs		= tcm_loop_tpg_attrs,
1177 	.tfc_tpg_attrib_attrs		= tcm_loop_tpg_attrib_attrs,
1178 };
1179 
1180 static int __init tcm_loop_fabric_init(void)
1181 {
1182 	int ret = -ENOMEM;
1183 
1184 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1185 	if (!tcm_loop_workqueue)
1186 		goto out;
1187 
1188 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1189 				sizeof(struct tcm_loop_cmd),
1190 				__alignof__(struct tcm_loop_cmd),
1191 				0, NULL);
1192 	if (!tcm_loop_cmd_cache) {
1193 		pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1194 		goto out_destroy_workqueue;
1195 	}
1196 
1197 	ret = tcm_loop_alloc_core_bus();
1198 	if (ret)
1199 		goto out_destroy_cache;
1200 
1201 	ret = target_register_template(&loop_ops);
1202 	if (ret)
1203 		goto out_release_core_bus;
1204 
1205 	return 0;
1206 
1207 out_release_core_bus:
1208 	tcm_loop_release_core_bus();
1209 out_destroy_cache:
1210 	kmem_cache_destroy(tcm_loop_cmd_cache);
1211 out_destroy_workqueue:
1212 	destroy_workqueue(tcm_loop_workqueue);
1213 out:
1214 	return ret;
1215 }
1216 
1217 static void __exit tcm_loop_fabric_exit(void)
1218 {
1219 	target_unregister_template(&loop_ops);
1220 	tcm_loop_release_core_bus();
1221 	kmem_cache_destroy(tcm_loop_cmd_cache);
1222 	destroy_workqueue(tcm_loop_workqueue);
1223 }
1224 
1225 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1226 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1227 MODULE_LICENSE("GPL");
1228 module_init(tcm_loop_fabric_init);
1229 module_exit(tcm_loop_fabric_exit);
1230