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 <[email protected]>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  ****************************************************************************/
22 
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/configfs.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_cmnd.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_fabric.h>
37 #include <target/target_core_fabric_configfs.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "tcm_loop.h"
41 
42 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
43 
44 static const struct target_core_fabric_ops loop_ops;
45 
46 static struct workqueue_struct *tcm_loop_workqueue;
47 static struct kmem_cache *tcm_loop_cmd_cache;
48 
49 static int tcm_loop_hba_no_cnt;
50 
51 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
52 
53 /*
54  * Called from struct target_core_fabric_ops->check_stop_free()
55  */
56 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
57 {
58 	/*
59 	 * Do not release struct se_cmd's containing a valid TMR
60 	 * pointer.  These will be released directly in tcm_loop_device_reset()
61 	 * with transport_generic_free_cmd().
62 	 */
63 	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
64 		return 0;
65 	/*
66 	 * Release the struct se_cmd, which will make a callback to release
67 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
68 	 */
69 	transport_generic_free_cmd(se_cmd, 0);
70 	return 1;
71 }
72 
73 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
74 {
75 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
76 				struct tcm_loop_cmd, tl_se_cmd);
77 
78 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
79 }
80 
81 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
82 {
83 	seq_printf(m, "tcm_loop_proc_info()\n");
84 	return 0;
85 }
86 
87 static int tcm_loop_driver_probe(struct device *);
88 static int tcm_loop_driver_remove(struct device *);
89 
90 static int pseudo_lld_bus_match(struct device *dev,
91 				struct device_driver *dev_driver)
92 {
93 	return 1;
94 }
95 
96 static struct bus_type tcm_loop_lld_bus = {
97 	.name			= "tcm_loop_bus",
98 	.match			= pseudo_lld_bus_match,
99 	.probe			= tcm_loop_driver_probe,
100 	.remove			= tcm_loop_driver_remove,
101 };
102 
103 static struct device_driver tcm_loop_driverfs = {
104 	.name			= "tcm_loop",
105 	.bus			= &tcm_loop_lld_bus,
106 };
107 /*
108  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
109  */
110 static struct device *tcm_loop_primary;
111 
112 static void tcm_loop_submission_work(struct work_struct *work)
113 {
114 	struct tcm_loop_cmd *tl_cmd =
115 		container_of(work, struct tcm_loop_cmd, work);
116 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
117 	struct scsi_cmnd *sc = tl_cmd->sc;
118 	struct tcm_loop_nexus *tl_nexus;
119 	struct tcm_loop_hba *tl_hba;
120 	struct tcm_loop_tpg *tl_tpg;
121 	struct scatterlist *sgl_bidi = NULL;
122 	u32 sgl_bidi_count = 0, transfer_length;
123 	int rc;
124 
125 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
126 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
127 
128 	/*
129 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
130 	 * has already been configured via tcm_loop_make_naa_tpg().
131 	 */
132 	if (!tl_tpg->tl_hba) {
133 		set_host_byte(sc, DID_NO_CONNECT);
134 		goto out_done;
135 	}
136 	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
137 		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
138 		goto out_done;
139 	}
140 	tl_nexus = tl_tpg->tl_nexus;
141 	if (!tl_nexus) {
142 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
143 				" does not exist\n");
144 		set_host_byte(sc, DID_ERROR);
145 		goto out_done;
146 	}
147 	if (scsi_bidi_cmnd(sc)) {
148 		struct scsi_data_buffer *sdb = scsi_in(sc);
149 
150 		sgl_bidi = sdb->table.sgl;
151 		sgl_bidi_count = sdb->table.nents;
152 		se_cmd->se_cmd_flags |= SCF_BIDI;
153 
154 	}
155 
156 	transfer_length = scsi_transfer_length(sc);
157 	if (!scsi_prot_sg_count(sc) &&
158 	    scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
159 		se_cmd->prot_pto = true;
160 		/*
161 		 * loopback transport doesn't support
162 		 * WRITE_GENERATE, READ_STRIP protection
163 		 * information operations, go ahead unprotected.
164 		 */
165 		transfer_length = scsi_bufflen(sc);
166 	}
167 
168 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
169 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
170 			transfer_length, TCM_SIMPLE_TAG,
171 			sc->sc_data_direction, 0,
172 			scsi_sglist(sc), scsi_sg_count(sc),
173 			sgl_bidi, sgl_bidi_count,
174 			scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
175 	if (rc < 0) {
176 		set_host_byte(sc, DID_NO_CONNECT);
177 		goto out_done;
178 	}
179 	return;
180 
181 out_done:
182 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
183 	sc->scsi_done(sc);
184 	return;
185 }
186 
187 /*
188  * ->queuecommand can be and usually is called from interrupt context, so
189  * defer the actual submission to a workqueue.
190  */
191 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
192 {
193 	struct tcm_loop_cmd *tl_cmd;
194 
195 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%llu got CDB: 0x%02x"
196 		" scsi_buf_len: %u\n", sc->device->host->host_no,
197 		sc->device->id, sc->device->channel, sc->device->lun,
198 		sc->cmnd[0], scsi_bufflen(sc));
199 
200 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
201 	if (!tl_cmd) {
202 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
203 		set_host_byte(sc, DID_ERROR);
204 		sc->scsi_done(sc);
205 		return 0;
206 	}
207 
208 	tl_cmd->sc = sc;
209 	tl_cmd->sc_cmd_tag = sc->request->tag;
210 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
211 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
212 	return 0;
213 }
214 
215 /*
216  * Called from SCSI EH process context to issue a LUN_RESET TMR
217  * to struct scsi_device
218  */
219 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
220 			      int lun, int task, enum tcm_tmreq_table tmr)
221 {
222 	struct se_cmd *se_cmd = NULL;
223 	struct se_session *se_sess;
224 	struct se_portal_group *se_tpg;
225 	struct tcm_loop_nexus *tl_nexus;
226 	struct tcm_loop_cmd *tl_cmd = NULL;
227 	struct tcm_loop_tmr *tl_tmr = NULL;
228 	int ret = TMR_FUNCTION_FAILED, rc;
229 
230 	/*
231 	 * Locate the tl_nexus and se_sess pointers
232 	 */
233 	tl_nexus = tl_tpg->tl_nexus;
234 	if (!tl_nexus) {
235 		pr_err("Unable to perform device reset without"
236 				" active I_T Nexus\n");
237 		return ret;
238 	}
239 
240 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
241 	if (!tl_cmd) {
242 		pr_err("Unable to allocate memory for tl_cmd\n");
243 		return ret;
244 	}
245 
246 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
247 	if (!tl_tmr) {
248 		pr_err("Unable to allocate memory for tl_tmr\n");
249 		goto release;
250 	}
251 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
252 
253 	se_cmd = &tl_cmd->tl_se_cmd;
254 	se_tpg = &tl_tpg->tl_se_tpg;
255 	se_sess = tl_tpg->tl_nexus->se_sess;
256 	/*
257 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
258 	 */
259 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
260 				DMA_NONE, TCM_SIMPLE_TAG,
261 				&tl_cmd->tl_sense_buf[0]);
262 
263 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
264 	if (rc < 0)
265 		goto release;
266 
267 	if (tmr == TMR_ABORT_TASK)
268 		se_cmd->se_tmr_req->ref_task_tag = task;
269 
270 	/*
271 	 * Locate the underlying TCM struct se_lun
272 	 */
273 	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
274 		ret = TMR_LUN_DOES_NOT_EXIST;
275 		goto release;
276 	}
277 	/*
278 	 * Queue the TMR to TCM Core and sleep waiting for
279 	 * tcm_loop_queue_tm_rsp() to wake us up.
280 	 */
281 	transport_generic_handle_tmr(se_cmd);
282 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
283 	/*
284 	 * The TMR LUN_RESET has completed, check the response status and
285 	 * then release allocations.
286 	 */
287 	ret = se_cmd->se_tmr_req->response;
288 release:
289 	if (se_cmd)
290 		transport_generic_free_cmd(se_cmd, 1);
291 	else
292 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
293 	kfree(tl_tmr);
294 	return ret;
295 }
296 
297 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
298 {
299 	struct tcm_loop_hba *tl_hba;
300 	struct tcm_loop_tpg *tl_tpg;
301 	int ret = FAILED;
302 
303 	/*
304 	 * Locate the tcm_loop_hba_t pointer
305 	 */
306 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
307 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
308 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
309 				 sc->request->tag, TMR_ABORT_TASK);
310 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
311 }
312 
313 /*
314  * Called from SCSI EH process context to issue a LUN_RESET TMR
315  * to struct scsi_device
316  */
317 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
318 {
319 	struct tcm_loop_hba *tl_hba;
320 	struct tcm_loop_tpg *tl_tpg;
321 	int ret = FAILED;
322 
323 	/*
324 	 * Locate the tcm_loop_hba_t pointer
325 	 */
326 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
327 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
328 
329 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
330 				 0, TMR_LUN_RESET);
331 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
332 }
333 
334 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
335 {
336 	struct tcm_loop_hba *tl_hba;
337 	struct tcm_loop_tpg *tl_tpg;
338 
339 	/*
340 	 * Locate the tcm_loop_hba_t pointer
341 	 */
342 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
343 	if (!tl_hba) {
344 		pr_err("Unable to perform device reset without"
345 				" active I_T Nexus\n");
346 		return FAILED;
347 	}
348 	/*
349 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
350 	 */
351 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
352 	if (tl_tpg) {
353 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
354 		return SUCCESS;
355 	}
356 	return FAILED;
357 }
358 
359 static int tcm_loop_slave_alloc(struct scsi_device *sd)
360 {
361 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
362 	return 0;
363 }
364 
365 static struct scsi_host_template tcm_loop_driver_template = {
366 	.show_info		= tcm_loop_show_info,
367 	.proc_name		= "tcm_loopback",
368 	.name			= "TCM_Loopback",
369 	.queuecommand		= tcm_loop_queuecommand,
370 	.change_queue_depth	= scsi_change_queue_depth,
371 	.eh_abort_handler = tcm_loop_abort_task,
372 	.eh_device_reset_handler = tcm_loop_device_reset,
373 	.eh_target_reset_handler = tcm_loop_target_reset,
374 	.can_queue		= 1024,
375 	.this_id		= -1,
376 	.sg_tablesize		= 256,
377 	.cmd_per_lun		= 1024,
378 	.max_sectors		= 0xFFFF,
379 	.use_clustering		= DISABLE_CLUSTERING,
380 	.slave_alloc		= tcm_loop_slave_alloc,
381 	.module			= THIS_MODULE,
382 	.use_blk_tags		= 1,
383 	.track_queue_depth	= 1,
384 };
385 
386 static int tcm_loop_driver_probe(struct device *dev)
387 {
388 	struct tcm_loop_hba *tl_hba;
389 	struct Scsi_Host *sh;
390 	int error, host_prot;
391 
392 	tl_hba = to_tcm_loop_hba(dev);
393 
394 	sh = scsi_host_alloc(&tcm_loop_driver_template,
395 			sizeof(struct tcm_loop_hba));
396 	if (!sh) {
397 		pr_err("Unable to allocate struct scsi_host\n");
398 		return -ENODEV;
399 	}
400 	tl_hba->sh = sh;
401 
402 	/*
403 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
404 	 */
405 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
406 	/*
407 	 * Setup single ID, Channel and LUN for now..
408 	 */
409 	sh->max_id = 2;
410 	sh->max_lun = 0;
411 	sh->max_channel = 0;
412 	sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
413 
414 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
415 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
416 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
417 
418 	scsi_host_set_prot(sh, host_prot);
419 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
420 
421 	error = scsi_add_host(sh, &tl_hba->dev);
422 	if (error) {
423 		pr_err("%s: scsi_add_host failed\n", __func__);
424 		scsi_host_put(sh);
425 		return -ENODEV;
426 	}
427 	return 0;
428 }
429 
430 static int tcm_loop_driver_remove(struct device *dev)
431 {
432 	struct tcm_loop_hba *tl_hba;
433 	struct Scsi_Host *sh;
434 
435 	tl_hba = to_tcm_loop_hba(dev);
436 	sh = tl_hba->sh;
437 
438 	scsi_remove_host(sh);
439 	scsi_host_put(sh);
440 	return 0;
441 }
442 
443 static void tcm_loop_release_adapter(struct device *dev)
444 {
445 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
446 
447 	kfree(tl_hba);
448 }
449 
450 /*
451  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
452  */
453 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
454 {
455 	int ret;
456 
457 	tl_hba->dev.bus = &tcm_loop_lld_bus;
458 	tl_hba->dev.parent = tcm_loop_primary;
459 	tl_hba->dev.release = &tcm_loop_release_adapter;
460 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
461 
462 	ret = device_register(&tl_hba->dev);
463 	if (ret) {
464 		pr_err("device_register() failed for"
465 				" tl_hba->dev: %d\n", ret);
466 		return -ENODEV;
467 	}
468 
469 	return 0;
470 }
471 
472 /*
473  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
474  * tcm_loop SCSI bus.
475  */
476 static int tcm_loop_alloc_core_bus(void)
477 {
478 	int ret;
479 
480 	tcm_loop_primary = root_device_register("tcm_loop_0");
481 	if (IS_ERR(tcm_loop_primary)) {
482 		pr_err("Unable to allocate tcm_loop_primary\n");
483 		return PTR_ERR(tcm_loop_primary);
484 	}
485 
486 	ret = bus_register(&tcm_loop_lld_bus);
487 	if (ret) {
488 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
489 		goto dev_unreg;
490 	}
491 
492 	ret = driver_register(&tcm_loop_driverfs);
493 	if (ret) {
494 		pr_err("driver_register() failed for"
495 				"tcm_loop_driverfs\n");
496 		goto bus_unreg;
497 	}
498 
499 	pr_debug("Initialized TCM Loop Core Bus\n");
500 	return ret;
501 
502 bus_unreg:
503 	bus_unregister(&tcm_loop_lld_bus);
504 dev_unreg:
505 	root_device_unregister(tcm_loop_primary);
506 	return ret;
507 }
508 
509 static void tcm_loop_release_core_bus(void)
510 {
511 	driver_unregister(&tcm_loop_driverfs);
512 	bus_unregister(&tcm_loop_lld_bus);
513 	root_device_unregister(tcm_loop_primary);
514 
515 	pr_debug("Releasing TCM Loop Core BUS\n");
516 }
517 
518 static char *tcm_loop_get_fabric_name(void)
519 {
520 	return "loopback";
521 }
522 
523 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
524 {
525 	return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
526 }
527 
528 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
529 {
530 	/*
531 	 * Return the passed NAA identifier for the SAS Target Port
532 	 */
533 	return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
534 }
535 
536 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
537 {
538 	/*
539 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
540 	 * to represent the SCSI Target Port.
541 	 */
542 	return tl_tpg(se_tpg)->tl_tpgt;
543 }
544 
545 static u32 tcm_loop_get_pr_transport_id(
546 	struct se_portal_group *se_tpg,
547 	struct se_node_acl *se_nacl,
548 	struct t10_pr_registration *pr_reg,
549 	int *format_code,
550 	unsigned char *buf)
551 {
552 	struct tcm_loop_hba *tl_hba = tl_tpg(se_tpg)->tl_hba;
553 
554 	switch (tl_hba->tl_proto_id) {
555 	case SCSI_PROTOCOL_SAS:
556 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
557 					format_code, buf);
558 	case SCSI_PROTOCOL_FCP:
559 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
560 					format_code, buf);
561 	case SCSI_PROTOCOL_ISCSI:
562 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
563 					format_code, buf);
564 	default:
565 		pr_err("Unknown tl_proto_id: 0x%02x, using"
566 			" SAS emulation\n", tl_hba->tl_proto_id);
567 		break;
568 	}
569 
570 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
571 			format_code, buf);
572 }
573 
574 static u32 tcm_loop_get_pr_transport_id_len(
575 	struct se_portal_group *se_tpg,
576 	struct se_node_acl *se_nacl,
577 	struct t10_pr_registration *pr_reg,
578 	int *format_code)
579 {
580 	struct tcm_loop_hba *tl_hba = tl_tpg(se_tpg)->tl_hba;
581 
582 	switch (tl_hba->tl_proto_id) {
583 	case SCSI_PROTOCOL_SAS:
584 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
585 					format_code);
586 	case SCSI_PROTOCOL_FCP:
587 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
588 					format_code);
589 	case SCSI_PROTOCOL_ISCSI:
590 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
591 					format_code);
592 	default:
593 		pr_err("Unknown tl_proto_id: 0x%02x, using"
594 			" SAS emulation\n", tl_hba->tl_proto_id);
595 		break;
596 	}
597 
598 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
599 			format_code);
600 }
601 
602 /*
603  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
604  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
605  */
606 static char *tcm_loop_parse_pr_out_transport_id(
607 	struct se_portal_group *se_tpg,
608 	const char *buf,
609 	u32 *out_tid_len,
610 	char **port_nexus_ptr)
611 {
612 	struct tcm_loop_hba *tl_hba = tl_tpg(se_tpg)->tl_hba;
613 
614 	switch (tl_hba->tl_proto_id) {
615 	case SCSI_PROTOCOL_SAS:
616 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
617 					port_nexus_ptr);
618 	case SCSI_PROTOCOL_FCP:
619 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
620 					port_nexus_ptr);
621 	case SCSI_PROTOCOL_ISCSI:
622 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
623 					port_nexus_ptr);
624 	default:
625 		pr_err("Unknown tl_proto_id: 0x%02x, using"
626 			" SAS emulation\n", tl_hba->tl_proto_id);
627 		break;
628 	}
629 
630 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
631 			port_nexus_ptr);
632 }
633 
634 /*
635  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
636  * based upon the incoming fabric dependent SCSI Initiator Port
637  */
638 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
639 {
640 	return 1;
641 }
642 
643 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
644 {
645 	return 0;
646 }
647 
648 /*
649  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
650  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
651  */
652 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
653 {
654 	return 0;
655 }
656 
657 /*
658  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
659  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
660  * It has been added here as a nop for target_fabric_tf_ops_check()
661  */
662 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
663 {
664 	return 0;
665 }
666 
667 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
668 {
669 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
670 						   tl_se_tpg);
671 	return tl_tpg->tl_fabric_prot_type;
672 }
673 
674 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
675 {
676 	return 1;
677 }
678 
679 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
680 {
681 	return 1;
682 }
683 
684 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
685 {
686 	return;
687 }
688 
689 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
690 {
691 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
692 			struct tcm_loop_cmd, tl_se_cmd);
693 
694 	return tl_cmd->sc_cmd_tag;
695 }
696 
697 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
698 {
699 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
700 			struct tcm_loop_cmd, tl_se_cmd);
701 
702 	return tl_cmd->sc_cmd_state;
703 }
704 
705 static int tcm_loop_shutdown_session(struct se_session *se_sess)
706 {
707 	return 0;
708 }
709 
710 static void tcm_loop_close_session(struct se_session *se_sess)
711 {
712 	return;
713 };
714 
715 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
716 {
717 	/*
718 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
719 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
720 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
721 	 * format with transport_generic_map_mem_to_cmd().
722 	 *
723 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
724 	 * object execution queue.
725 	 */
726 	target_execute_cmd(se_cmd);
727 	return 0;
728 }
729 
730 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
731 {
732 	return 0;
733 }
734 
735 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
736 {
737 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
738 				struct tcm_loop_cmd, tl_se_cmd);
739 	struct scsi_cmnd *sc = tl_cmd->sc;
740 
741 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
742 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
743 
744 	sc->result = SAM_STAT_GOOD;
745 	set_host_byte(sc, DID_OK);
746 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
747 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
748 		scsi_set_resid(sc, se_cmd->residual_count);
749 	sc->scsi_done(sc);
750 	return 0;
751 }
752 
753 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
754 {
755 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
756 				struct tcm_loop_cmd, tl_se_cmd);
757 	struct scsi_cmnd *sc = tl_cmd->sc;
758 
759 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
760 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
761 
762 	if (se_cmd->sense_buffer &&
763 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
764 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
765 
766 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
767 				SCSI_SENSE_BUFFERSIZE);
768 		sc->result = SAM_STAT_CHECK_CONDITION;
769 		set_driver_byte(sc, DRIVER_SENSE);
770 	} else
771 		sc->result = se_cmd->scsi_status;
772 
773 	set_host_byte(sc, DID_OK);
774 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
775 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
776 		scsi_set_resid(sc, se_cmd->residual_count);
777 	sc->scsi_done(sc);
778 	return 0;
779 }
780 
781 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
782 {
783 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
784 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
785 	/*
786 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
787 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
788 	 */
789 	atomic_set(&tl_tmr->tmr_complete, 1);
790 	wake_up(&tl_tmr->tl_tmr_wait);
791 }
792 
793 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
794 {
795 	return;
796 }
797 
798 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
799 {
800 	switch (tl_hba->tl_proto_id) {
801 	case SCSI_PROTOCOL_SAS:
802 		return "SAS";
803 	case SCSI_PROTOCOL_FCP:
804 		return "FCP";
805 	case SCSI_PROTOCOL_ISCSI:
806 		return "iSCSI";
807 	default:
808 		break;
809 	}
810 
811 	return "Unknown";
812 }
813 
814 /* Start items for tcm_loop_port_cit */
815 
816 static int tcm_loop_port_link(
817 	struct se_portal_group *se_tpg,
818 	struct se_lun *lun)
819 {
820 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
821 				struct tcm_loop_tpg, tl_se_tpg);
822 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
823 
824 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
825 	/*
826 	 * Add Linux/SCSI struct scsi_device by HCTL
827 	 */
828 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
829 
830 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
831 	return 0;
832 }
833 
834 static void tcm_loop_port_unlink(
835 	struct se_portal_group *se_tpg,
836 	struct se_lun *se_lun)
837 {
838 	struct scsi_device *sd;
839 	struct tcm_loop_hba *tl_hba;
840 	struct tcm_loop_tpg *tl_tpg;
841 
842 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
843 	tl_hba = tl_tpg->tl_hba;
844 
845 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
846 				se_lun->unpacked_lun);
847 	if (!sd) {
848 		pr_err("Unable to locate struct scsi_device for %d:%d:"
849 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
850 		return;
851 	}
852 	/*
853 	 * Remove Linux/SCSI struct scsi_device by HCTL
854 	 */
855 	scsi_remove_device(sd);
856 	scsi_device_put(sd);
857 
858 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
859 
860 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
861 }
862 
863 /* End items for tcm_loop_port_cit */
864 
865 static ssize_t tcm_loop_tpg_attrib_show_fabric_prot_type(
866 	struct se_portal_group *se_tpg,
867 	char *page)
868 {
869 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
870 						   tl_se_tpg);
871 
872 	return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
873 }
874 
875 static ssize_t tcm_loop_tpg_attrib_store_fabric_prot_type(
876 	struct se_portal_group *se_tpg,
877 	const char *page,
878 	size_t count)
879 {
880 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
881 						   tl_se_tpg);
882 	unsigned long val;
883 	int ret = kstrtoul(page, 0, &val);
884 
885 	if (ret) {
886 		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
887 		return ret;
888 	}
889 	if (val != 0 && val != 1 && val != 3) {
890 		pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
891 		return -EINVAL;
892 	}
893 	tl_tpg->tl_fabric_prot_type = val;
894 
895 	return count;
896 }
897 
898 TF_TPG_ATTRIB_ATTR(tcm_loop, fabric_prot_type, S_IRUGO | S_IWUSR);
899 
900 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
901 	&tcm_loop_tpg_attrib_fabric_prot_type.attr,
902 	NULL,
903 };
904 
905 /* Start items for tcm_loop_nexus_cit */
906 
907 static int tcm_loop_make_nexus(
908 	struct tcm_loop_tpg *tl_tpg,
909 	const char *name)
910 {
911 	struct se_portal_group *se_tpg;
912 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
913 	struct tcm_loop_nexus *tl_nexus;
914 	int ret = -ENOMEM;
915 
916 	if (tl_tpg->tl_nexus) {
917 		pr_debug("tl_tpg->tl_nexus already exists\n");
918 		return -EEXIST;
919 	}
920 	se_tpg = &tl_tpg->tl_se_tpg;
921 
922 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
923 	if (!tl_nexus) {
924 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
925 		return -ENOMEM;
926 	}
927 	/*
928 	 * Initialize the struct se_session pointer
929 	 */
930 	tl_nexus->se_sess = transport_init_session(
931 				TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
932 	if (IS_ERR(tl_nexus->se_sess)) {
933 		ret = PTR_ERR(tl_nexus->se_sess);
934 		goto out;
935 	}
936 	/*
937 	 * Since we are running in 'demo mode' this call with generate a
938 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
939 	 * Initiator port name of the passed configfs group 'name'.
940 	 */
941 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
942 				se_tpg, (unsigned char *)name);
943 	if (!tl_nexus->se_sess->se_node_acl) {
944 		transport_free_session(tl_nexus->se_sess);
945 		goto out;
946 	}
947 	/* Now, register the SAS I_T Nexus as active. */
948 	transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
949 			tl_nexus->se_sess, tl_nexus);
950 	tl_tpg->tl_nexus = tl_nexus;
951 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
952 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
953 		name);
954 	return 0;
955 
956 out:
957 	kfree(tl_nexus);
958 	return ret;
959 }
960 
961 static int tcm_loop_drop_nexus(
962 	struct tcm_loop_tpg *tpg)
963 {
964 	struct se_session *se_sess;
965 	struct tcm_loop_nexus *tl_nexus;
966 
967 	tl_nexus = tpg->tl_nexus;
968 	if (!tl_nexus)
969 		return -ENODEV;
970 
971 	se_sess = tl_nexus->se_sess;
972 	if (!se_sess)
973 		return -ENODEV;
974 
975 	if (atomic_read(&tpg->tl_tpg_port_count)) {
976 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
977 			" active TPG port count: %d\n",
978 			atomic_read(&tpg->tl_tpg_port_count));
979 		return -EPERM;
980 	}
981 
982 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
983 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tpg->tl_hba),
984 		tl_nexus->se_sess->se_node_acl->initiatorname);
985 	/*
986 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
987 	 */
988 	transport_deregister_session(tl_nexus->se_sess);
989 	tpg->tl_nexus = NULL;
990 	kfree(tl_nexus);
991 	return 0;
992 }
993 
994 /* End items for tcm_loop_nexus_cit */
995 
996 static ssize_t tcm_loop_tpg_show_nexus(
997 	struct se_portal_group *se_tpg,
998 	char *page)
999 {
1000 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1001 			struct tcm_loop_tpg, tl_se_tpg);
1002 	struct tcm_loop_nexus *tl_nexus;
1003 	ssize_t ret;
1004 
1005 	tl_nexus = tl_tpg->tl_nexus;
1006 	if (!tl_nexus)
1007 		return -ENODEV;
1008 
1009 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1010 		tl_nexus->se_sess->se_node_acl->initiatorname);
1011 
1012 	return ret;
1013 }
1014 
1015 static ssize_t tcm_loop_tpg_store_nexus(
1016 	struct se_portal_group *se_tpg,
1017 	const char *page,
1018 	size_t count)
1019 {
1020 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1021 			struct tcm_loop_tpg, tl_se_tpg);
1022 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1023 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1024 	int ret;
1025 	/*
1026 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1027 	 */
1028 	if (!strncmp(page, "NULL", 4)) {
1029 		ret = tcm_loop_drop_nexus(tl_tpg);
1030 		return (!ret) ? count : ret;
1031 	}
1032 	/*
1033 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1034 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1035 	 * tcm_loop_make_nexus()
1036 	 */
1037 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1038 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1039 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1040 		return -EINVAL;
1041 	}
1042 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1043 
1044 	ptr = strstr(i_port, "naa.");
1045 	if (ptr) {
1046 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1047 			pr_err("Passed SAS Initiator Port %s does not"
1048 				" match target port protoid: %s\n", i_port,
1049 				tcm_loop_dump_proto_id(tl_hba));
1050 			return -EINVAL;
1051 		}
1052 		port_ptr = &i_port[0];
1053 		goto check_newline;
1054 	}
1055 	ptr = strstr(i_port, "fc.");
1056 	if (ptr) {
1057 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1058 			pr_err("Passed FCP Initiator Port %s does not"
1059 				" match target port protoid: %s\n", i_port,
1060 				tcm_loop_dump_proto_id(tl_hba));
1061 			return -EINVAL;
1062 		}
1063 		port_ptr = &i_port[3]; /* Skip over "fc." */
1064 		goto check_newline;
1065 	}
1066 	ptr = strstr(i_port, "iqn.");
1067 	if (ptr) {
1068 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1069 			pr_err("Passed iSCSI Initiator Port %s does not"
1070 				" match target port protoid: %s\n", i_port,
1071 				tcm_loop_dump_proto_id(tl_hba));
1072 			return -EINVAL;
1073 		}
1074 		port_ptr = &i_port[0];
1075 		goto check_newline;
1076 	}
1077 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1078 			" %s\n", i_port);
1079 	return -EINVAL;
1080 	/*
1081 	 * Clear any trailing newline for the NAA WWN
1082 	 */
1083 check_newline:
1084 	if (i_port[strlen(i_port)-1] == '\n')
1085 		i_port[strlen(i_port)-1] = '\0';
1086 
1087 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1088 	if (ret < 0)
1089 		return ret;
1090 
1091 	return count;
1092 }
1093 
1094 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1095 
1096 static ssize_t tcm_loop_tpg_show_transport_status(
1097 	struct se_portal_group *se_tpg,
1098 	char *page)
1099 {
1100 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1101 			struct tcm_loop_tpg, tl_se_tpg);
1102 	const char *status = NULL;
1103 	ssize_t ret = -EINVAL;
1104 
1105 	switch (tl_tpg->tl_transport_status) {
1106 	case TCM_TRANSPORT_ONLINE:
1107 		status = "online";
1108 		break;
1109 	case TCM_TRANSPORT_OFFLINE:
1110 		status = "offline";
1111 		break;
1112 	default:
1113 		break;
1114 	}
1115 
1116 	if (status)
1117 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1118 
1119 	return ret;
1120 }
1121 
1122 static ssize_t tcm_loop_tpg_store_transport_status(
1123 	struct se_portal_group *se_tpg,
1124 	const char *page,
1125 	size_t count)
1126 {
1127 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1128 			struct tcm_loop_tpg, tl_se_tpg);
1129 
1130 	if (!strncmp(page, "online", 6)) {
1131 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1132 		return count;
1133 	}
1134 	if (!strncmp(page, "offline", 7)) {
1135 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1136 		return count;
1137 	}
1138 	return -EINVAL;
1139 }
1140 
1141 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1142 
1143 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1144 	&tcm_loop_tpg_nexus.attr,
1145 	&tcm_loop_tpg_transport_status.attr,
1146 	NULL,
1147 };
1148 
1149 /* Start items for tcm_loop_naa_cit */
1150 
1151 static struct se_portal_group *tcm_loop_make_naa_tpg(
1152 	struct se_wwn *wwn,
1153 	struct config_group *group,
1154 	const char *name)
1155 {
1156 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1157 			struct tcm_loop_hba, tl_hba_wwn);
1158 	struct tcm_loop_tpg *tl_tpg;
1159 	int ret;
1160 	unsigned long tpgt;
1161 
1162 	if (strstr(name, "tpgt_") != name) {
1163 		pr_err("Unable to locate \"tpgt_#\" directory"
1164 				" group\n");
1165 		return ERR_PTR(-EINVAL);
1166 	}
1167 	if (kstrtoul(name+5, 10, &tpgt))
1168 		return ERR_PTR(-EINVAL);
1169 
1170 	if (tpgt >= TL_TPGS_PER_HBA) {
1171 		pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA:"
1172 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1173 		return ERR_PTR(-EINVAL);
1174 	}
1175 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1176 	tl_tpg->tl_hba = tl_hba;
1177 	tl_tpg->tl_tpgt = tpgt;
1178 	/*
1179 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1180 	 */
1181 	ret = core_tpg_register(&loop_ops, wwn, &tl_tpg->tl_se_tpg,
1182 				tl_hba->tl_proto_id);
1183 	if (ret < 0)
1184 		return ERR_PTR(-ENOMEM);
1185 
1186 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1187 		" Target Port %s,t,0x%04lx\n", tcm_loop_dump_proto_id(tl_hba),
1188 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1189 
1190 	return &tl_tpg->tl_se_tpg;
1191 }
1192 
1193 static void tcm_loop_drop_naa_tpg(
1194 	struct se_portal_group *se_tpg)
1195 {
1196 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1197 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1198 				struct tcm_loop_tpg, tl_se_tpg);
1199 	struct tcm_loop_hba *tl_hba;
1200 	unsigned short tpgt;
1201 
1202 	tl_hba = tl_tpg->tl_hba;
1203 	tpgt = tl_tpg->tl_tpgt;
1204 	/*
1205 	 * Release the I_T Nexus for the Virtual SAS link if present
1206 	 */
1207 	tcm_loop_drop_nexus(tl_tpg);
1208 	/*
1209 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1210 	 */
1211 	core_tpg_deregister(se_tpg);
1212 
1213 	tl_tpg->tl_hba = NULL;
1214 	tl_tpg->tl_tpgt = 0;
1215 
1216 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1217 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1218 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1219 }
1220 
1221 /* End items for tcm_loop_naa_cit */
1222 
1223 /* Start items for tcm_loop_cit */
1224 
1225 static struct se_wwn *tcm_loop_make_scsi_hba(
1226 	struct target_fabric_configfs *tf,
1227 	struct config_group *group,
1228 	const char *name)
1229 {
1230 	struct tcm_loop_hba *tl_hba;
1231 	struct Scsi_Host *sh;
1232 	char *ptr;
1233 	int ret, off = 0;
1234 
1235 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1236 	if (!tl_hba) {
1237 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1238 		return ERR_PTR(-ENOMEM);
1239 	}
1240 	/*
1241 	 * Determine the emulated Protocol Identifier and Target Port Name
1242 	 * based on the incoming configfs directory name.
1243 	 */
1244 	ptr = strstr(name, "naa.");
1245 	if (ptr) {
1246 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1247 		goto check_len;
1248 	}
1249 	ptr = strstr(name, "fc.");
1250 	if (ptr) {
1251 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1252 		off = 3; /* Skip over "fc." */
1253 		goto check_len;
1254 	}
1255 	ptr = strstr(name, "iqn.");
1256 	if (!ptr) {
1257 		pr_err("Unable to locate prefix for emulated Target "
1258 				"Port: %s\n", name);
1259 		ret = -EINVAL;
1260 		goto out;
1261 	}
1262 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1263 
1264 check_len:
1265 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1266 		pr_err("Emulated NAA %s Address: %s, exceeds"
1267 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1268 			TL_WWN_ADDR_LEN);
1269 		ret = -EINVAL;
1270 		goto out;
1271 	}
1272 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1273 
1274 	/*
1275 	 * Call device_register(tl_hba->dev) to register the emulated
1276 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1277 	 * device_register() callbacks in tcm_loop_driver_probe()
1278 	 */
1279 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1280 	if (ret)
1281 		goto out;
1282 
1283 	sh = tl_hba->sh;
1284 	tcm_loop_hba_no_cnt++;
1285 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1286 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1287 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1288 
1289 	return &tl_hba->tl_hba_wwn;
1290 out:
1291 	kfree(tl_hba);
1292 	return ERR_PTR(ret);
1293 }
1294 
1295 static void tcm_loop_drop_scsi_hba(
1296 	struct se_wwn *wwn)
1297 {
1298 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1299 				struct tcm_loop_hba, tl_hba_wwn);
1300 
1301 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1302 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1303 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1304 	/*
1305 	 * Call device_unregister() on the original tl_hba->dev.
1306 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1307 	 * release *tl_hba;
1308 	 */
1309 	device_unregister(&tl_hba->dev);
1310 }
1311 
1312 /* Start items for tcm_loop_cit */
1313 static ssize_t tcm_loop_wwn_show_attr_version(
1314 	struct target_fabric_configfs *tf,
1315 	char *page)
1316 {
1317 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1318 }
1319 
1320 TF_WWN_ATTR_RO(tcm_loop, version);
1321 
1322 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1323 	&tcm_loop_wwn_version.attr,
1324 	NULL,
1325 };
1326 
1327 /* End items for tcm_loop_cit */
1328 
1329 static const struct target_core_fabric_ops loop_ops = {
1330 	.module				= THIS_MODULE,
1331 	.name				= "loopback",
1332 	.get_fabric_name		= tcm_loop_get_fabric_name,
1333 	.tpg_get_wwn			= tcm_loop_get_endpoint_wwn,
1334 	.tpg_get_tag			= tcm_loop_get_tag,
1335 	.tpg_get_pr_transport_id	= tcm_loop_get_pr_transport_id,
1336 	.tpg_get_pr_transport_id_len	= tcm_loop_get_pr_transport_id_len,
1337 	.tpg_parse_pr_out_transport_id	= tcm_loop_parse_pr_out_transport_id,
1338 	.tpg_check_demo_mode		= tcm_loop_check_demo_mode,
1339 	.tpg_check_demo_mode_cache	= tcm_loop_check_demo_mode_cache,
1340 	.tpg_check_demo_mode_write_protect =
1341 				tcm_loop_check_demo_mode_write_protect,
1342 	.tpg_check_prod_mode_write_protect =
1343 				tcm_loop_check_prod_mode_write_protect,
1344 	.tpg_check_prot_fabric_only	= tcm_loop_check_prot_fabric_only,
1345 	.tpg_get_inst_index		= tcm_loop_get_inst_index,
1346 	.check_stop_free		= tcm_loop_check_stop_free,
1347 	.release_cmd			= tcm_loop_release_cmd,
1348 	.shutdown_session		= tcm_loop_shutdown_session,
1349 	.close_session			= tcm_loop_close_session,
1350 	.sess_get_index			= tcm_loop_sess_get_index,
1351 	.write_pending			= tcm_loop_write_pending,
1352 	.write_pending_status		= tcm_loop_write_pending_status,
1353 	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
1354 	.get_task_tag			= tcm_loop_get_task_tag,
1355 	.get_cmd_state			= tcm_loop_get_cmd_state,
1356 	.queue_data_in			= tcm_loop_queue_data_in,
1357 	.queue_status			= tcm_loop_queue_status,
1358 	.queue_tm_rsp			= tcm_loop_queue_tm_rsp,
1359 	.aborted_task			= tcm_loop_aborted_task,
1360 	.fabric_make_wwn		= tcm_loop_make_scsi_hba,
1361 	.fabric_drop_wwn		= tcm_loop_drop_scsi_hba,
1362 	.fabric_make_tpg		= tcm_loop_make_naa_tpg,
1363 	.fabric_drop_tpg		= tcm_loop_drop_naa_tpg,
1364 	.fabric_post_link		= tcm_loop_port_link,
1365 	.fabric_pre_unlink		= tcm_loop_port_unlink,
1366 	.tfc_wwn_attrs			= tcm_loop_wwn_attrs,
1367 	.tfc_tpg_base_attrs		= tcm_loop_tpg_attrs,
1368 	.tfc_tpg_attrib_attrs		= tcm_loop_tpg_attrib_attrs,
1369 };
1370 
1371 static int __init tcm_loop_fabric_init(void)
1372 {
1373 	int ret = -ENOMEM;
1374 
1375 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1376 	if (!tcm_loop_workqueue)
1377 		goto out;
1378 
1379 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1380 				sizeof(struct tcm_loop_cmd),
1381 				__alignof__(struct tcm_loop_cmd),
1382 				0, NULL);
1383 	if (!tcm_loop_cmd_cache) {
1384 		pr_debug("kmem_cache_create() for"
1385 			" tcm_loop_cmd_cache failed\n");
1386 		goto out_destroy_workqueue;
1387 	}
1388 
1389 	ret = tcm_loop_alloc_core_bus();
1390 	if (ret)
1391 		goto out_destroy_cache;
1392 
1393 	ret = target_register_template(&loop_ops);
1394 	if (ret)
1395 		goto out_release_core_bus;
1396 
1397 	return 0;
1398 
1399 out_release_core_bus:
1400 	tcm_loop_release_core_bus();
1401 out_destroy_cache:
1402 	kmem_cache_destroy(tcm_loop_cmd_cache);
1403 out_destroy_workqueue:
1404 	destroy_workqueue(tcm_loop_workqueue);
1405 out:
1406 	return ret;
1407 }
1408 
1409 static void __exit tcm_loop_fabric_exit(void)
1410 {
1411 	target_unregister_template(&loop_ops);
1412 	tcm_loop_release_core_bus();
1413 	kmem_cache_destroy(tcm_loop_cmd_cache);
1414 	destroy_workqueue(tcm_loop_workqueue);
1415 }
1416 
1417 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1418 MODULE_AUTHOR("Nicholas A. Bellinger <[email protected]>");
1419 MODULE_LICENSE("GPL");
1420 module_init(tcm_loop_fabric_init);
1421 module_exit(tcm_loop_fabric_exit);
1422