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 	if (se_cmd)
243 		transport_generic_free_cmd(se_cmd, 0);
244 	else
245 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
246 	goto out;
247 }
248 
249 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
250 {
251 	struct tcm_loop_hba *tl_hba;
252 	struct tcm_loop_tpg *tl_tpg;
253 	int ret = FAILED;
254 
255 	/*
256 	 * Locate the tcm_loop_hba_t pointer
257 	 */
258 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
259 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
260 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
261 				 sc->request->tag, TMR_ABORT_TASK);
262 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
263 }
264 
265 /*
266  * Called from SCSI EH process context to issue a LUN_RESET TMR
267  * to struct scsi_device
268  */
269 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
270 {
271 	struct tcm_loop_hba *tl_hba;
272 	struct tcm_loop_tpg *tl_tpg;
273 	int ret = FAILED;
274 
275 	/*
276 	 * Locate the tcm_loop_hba_t pointer
277 	 */
278 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
279 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
280 
281 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
282 				 0, TMR_LUN_RESET);
283 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
284 }
285 
286 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
287 {
288 	struct tcm_loop_hba *tl_hba;
289 	struct tcm_loop_tpg *tl_tpg;
290 
291 	/*
292 	 * Locate the tcm_loop_hba_t pointer
293 	 */
294 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
295 	if (!tl_hba) {
296 		pr_err("Unable to perform device reset without active I_T Nexus\n");
297 		return FAILED;
298 	}
299 	/*
300 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
301 	 */
302 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
303 	if (tl_tpg) {
304 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
305 		return SUCCESS;
306 	}
307 	return FAILED;
308 }
309 
310 static int tcm_loop_slave_alloc(struct scsi_device *sd)
311 {
312 	blk_queue_flag_set(QUEUE_FLAG_BIDI, sd->request_queue);
313 	return 0;
314 }
315 
316 static struct scsi_host_template tcm_loop_driver_template = {
317 	.show_info		= tcm_loop_show_info,
318 	.proc_name		= "tcm_loopback",
319 	.name			= "TCM_Loopback",
320 	.queuecommand		= tcm_loop_queuecommand,
321 	.change_queue_depth	= scsi_change_queue_depth,
322 	.eh_abort_handler = tcm_loop_abort_task,
323 	.eh_device_reset_handler = tcm_loop_device_reset,
324 	.eh_target_reset_handler = tcm_loop_target_reset,
325 	.can_queue		= 1024,
326 	.this_id		= -1,
327 	.sg_tablesize		= 256,
328 	.cmd_per_lun		= 1024,
329 	.max_sectors		= 0xFFFF,
330 	.use_clustering		= DISABLE_CLUSTERING,
331 	.slave_alloc		= tcm_loop_slave_alloc,
332 	.module			= THIS_MODULE,
333 	.track_queue_depth	= 1,
334 };
335 
336 static int tcm_loop_driver_probe(struct device *dev)
337 {
338 	struct tcm_loop_hba *tl_hba;
339 	struct Scsi_Host *sh;
340 	int error, host_prot;
341 
342 	tl_hba = to_tcm_loop_hba(dev);
343 
344 	sh = scsi_host_alloc(&tcm_loop_driver_template,
345 			sizeof(struct tcm_loop_hba));
346 	if (!sh) {
347 		pr_err("Unable to allocate struct scsi_host\n");
348 		return -ENODEV;
349 	}
350 	tl_hba->sh = sh;
351 
352 	/*
353 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
354 	 */
355 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
356 	/*
357 	 * Setup single ID, Channel and LUN for now..
358 	 */
359 	sh->max_id = 2;
360 	sh->max_lun = 0;
361 	sh->max_channel = 0;
362 	sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
363 
364 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
365 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
366 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
367 
368 	scsi_host_set_prot(sh, host_prot);
369 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
370 
371 	error = scsi_add_host(sh, &tl_hba->dev);
372 	if (error) {
373 		pr_err("%s: scsi_add_host failed\n", __func__);
374 		scsi_host_put(sh);
375 		return -ENODEV;
376 	}
377 	return 0;
378 }
379 
380 static int tcm_loop_driver_remove(struct device *dev)
381 {
382 	struct tcm_loop_hba *tl_hba;
383 	struct Scsi_Host *sh;
384 
385 	tl_hba = to_tcm_loop_hba(dev);
386 	sh = tl_hba->sh;
387 
388 	scsi_remove_host(sh);
389 	scsi_host_put(sh);
390 	return 0;
391 }
392 
393 static void tcm_loop_release_adapter(struct device *dev)
394 {
395 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
396 
397 	kfree(tl_hba);
398 }
399 
400 /*
401  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
402  */
403 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
404 {
405 	int ret;
406 
407 	tl_hba->dev.bus = &tcm_loop_lld_bus;
408 	tl_hba->dev.parent = tcm_loop_primary;
409 	tl_hba->dev.release = &tcm_loop_release_adapter;
410 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
411 
412 	ret = device_register(&tl_hba->dev);
413 	if (ret) {
414 		pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
415 		return -ENODEV;
416 	}
417 
418 	return 0;
419 }
420 
421 /*
422  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
423  * tcm_loop SCSI bus.
424  */
425 static int tcm_loop_alloc_core_bus(void)
426 {
427 	int ret;
428 
429 	tcm_loop_primary = root_device_register("tcm_loop_0");
430 	if (IS_ERR(tcm_loop_primary)) {
431 		pr_err("Unable to allocate tcm_loop_primary\n");
432 		return PTR_ERR(tcm_loop_primary);
433 	}
434 
435 	ret = bus_register(&tcm_loop_lld_bus);
436 	if (ret) {
437 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
438 		goto dev_unreg;
439 	}
440 
441 	ret = driver_register(&tcm_loop_driverfs);
442 	if (ret) {
443 		pr_err("driver_register() failed for tcm_loop_driverfs\n");
444 		goto bus_unreg;
445 	}
446 
447 	pr_debug("Initialized TCM Loop Core Bus\n");
448 	return ret;
449 
450 bus_unreg:
451 	bus_unregister(&tcm_loop_lld_bus);
452 dev_unreg:
453 	root_device_unregister(tcm_loop_primary);
454 	return ret;
455 }
456 
457 static void tcm_loop_release_core_bus(void)
458 {
459 	driver_unregister(&tcm_loop_driverfs);
460 	bus_unregister(&tcm_loop_lld_bus);
461 	root_device_unregister(tcm_loop_primary);
462 
463 	pr_debug("Releasing TCM Loop Core BUS\n");
464 }
465 
466 static char *tcm_loop_get_fabric_name(void)
467 {
468 	return "loopback";
469 }
470 
471 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
472 {
473 	return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
474 }
475 
476 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
477 {
478 	/*
479 	 * Return the passed NAA identifier for the Target Port
480 	 */
481 	return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
482 }
483 
484 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
485 {
486 	/*
487 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
488 	 * to represent the SCSI Target Port.
489 	 */
490 	return tl_tpg(se_tpg)->tl_tpgt;
491 }
492 
493 /*
494  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
495  * based upon the incoming fabric dependent SCSI Initiator Port
496  */
497 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
498 {
499 	return 1;
500 }
501 
502 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
503 {
504 	return 0;
505 }
506 
507 /*
508  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
509  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
510  */
511 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
512 {
513 	return 0;
514 }
515 
516 /*
517  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
518  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
519  * It has been added here as a nop for target_fabric_tf_ops_check()
520  */
521 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
522 {
523 	return 0;
524 }
525 
526 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
527 {
528 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
529 						   tl_se_tpg);
530 	return tl_tpg->tl_fabric_prot_type;
531 }
532 
533 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
534 {
535 	return 1;
536 }
537 
538 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
539 {
540 	return 1;
541 }
542 
543 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
544 {
545 	return;
546 }
547 
548 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
549 {
550 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
551 			struct tcm_loop_cmd, tl_se_cmd);
552 
553 	return tl_cmd->sc_cmd_state;
554 }
555 
556 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
557 {
558 	/*
559 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
560 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
561 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
562 	 * format with transport_generic_map_mem_to_cmd().
563 	 *
564 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
565 	 * object execution queue.
566 	 */
567 	target_execute_cmd(se_cmd);
568 	return 0;
569 }
570 
571 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
572 {
573 	return 0;
574 }
575 
576 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
577 {
578 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
579 				struct tcm_loop_cmd, tl_se_cmd);
580 	struct scsi_cmnd *sc = tl_cmd->sc;
581 
582 	pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
583 		 __func__, sc, sc->cmnd[0]);
584 
585 	sc->result = SAM_STAT_GOOD;
586 	set_host_byte(sc, DID_OK);
587 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
588 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
589 		scsi_set_resid(sc, se_cmd->residual_count);
590 	sc->scsi_done(sc);
591 	return 0;
592 }
593 
594 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
595 {
596 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
597 				struct tcm_loop_cmd, tl_se_cmd);
598 	struct scsi_cmnd *sc = tl_cmd->sc;
599 
600 	pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
601 		 __func__, sc, sc->cmnd[0]);
602 
603 	if (se_cmd->sense_buffer &&
604 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
605 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
606 
607 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
608 				SCSI_SENSE_BUFFERSIZE);
609 		sc->result = SAM_STAT_CHECK_CONDITION;
610 		set_driver_byte(sc, DRIVER_SENSE);
611 	} else
612 		sc->result = se_cmd->scsi_status;
613 
614 	set_host_byte(sc, DID_OK);
615 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
616 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
617 		scsi_set_resid(sc, se_cmd->residual_count);
618 	sc->scsi_done(sc);
619 	return 0;
620 }
621 
622 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
623 {
624 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
625 				struct tcm_loop_cmd, tl_se_cmd);
626 
627 	/* Wake up tcm_loop_issue_tmr(). */
628 	complete(&tl_cmd->tmr_done);
629 }
630 
631 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
632 {
633 	return;
634 }
635 
636 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
637 {
638 	switch (tl_hba->tl_proto_id) {
639 	case SCSI_PROTOCOL_SAS:
640 		return "SAS";
641 	case SCSI_PROTOCOL_FCP:
642 		return "FCP";
643 	case SCSI_PROTOCOL_ISCSI:
644 		return "iSCSI";
645 	default:
646 		break;
647 	}
648 
649 	return "Unknown";
650 }
651 
652 /* Start items for tcm_loop_port_cit */
653 
654 static int tcm_loop_port_link(
655 	struct se_portal_group *se_tpg,
656 	struct se_lun *lun)
657 {
658 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
659 				struct tcm_loop_tpg, tl_se_tpg);
660 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
661 
662 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
663 	/*
664 	 * Add Linux/SCSI struct scsi_device by HCTL
665 	 */
666 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
667 
668 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
669 	return 0;
670 }
671 
672 static void tcm_loop_port_unlink(
673 	struct se_portal_group *se_tpg,
674 	struct se_lun *se_lun)
675 {
676 	struct scsi_device *sd;
677 	struct tcm_loop_hba *tl_hba;
678 	struct tcm_loop_tpg *tl_tpg;
679 
680 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
681 	tl_hba = tl_tpg->tl_hba;
682 
683 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
684 				se_lun->unpacked_lun);
685 	if (!sd) {
686 		pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
687 		       0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
688 		return;
689 	}
690 	/*
691 	 * Remove Linux/SCSI struct scsi_device by HCTL
692 	 */
693 	scsi_remove_device(sd);
694 	scsi_device_put(sd);
695 
696 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
697 
698 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
699 }
700 
701 /* End items for tcm_loop_port_cit */
702 
703 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
704 		struct config_item *item, char *page)
705 {
706 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
707 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
708 						   tl_se_tpg);
709 
710 	return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
711 }
712 
713 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
714 		struct config_item *item, const char *page, size_t count)
715 {
716 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
717 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
718 						   tl_se_tpg);
719 	unsigned long val;
720 	int ret = kstrtoul(page, 0, &val);
721 
722 	if (ret) {
723 		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
724 		return ret;
725 	}
726 	if (val != 0 && val != 1 && val != 3) {
727 		pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
728 		return -EINVAL;
729 	}
730 	tl_tpg->tl_fabric_prot_type = val;
731 
732 	return count;
733 }
734 
735 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
736 
737 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
738 	&tcm_loop_tpg_attrib_attr_fabric_prot_type,
739 	NULL,
740 };
741 
742 /* Start items for tcm_loop_nexus_cit */
743 
744 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
745 				  struct se_session *se_sess, void *p)
746 {
747 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
748 					struct tcm_loop_tpg, tl_se_tpg);
749 
750 	tl_tpg->tl_nexus = p;
751 	return 0;
752 }
753 
754 static int tcm_loop_make_nexus(
755 	struct tcm_loop_tpg *tl_tpg,
756 	const char *name)
757 {
758 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
759 	struct tcm_loop_nexus *tl_nexus;
760 	int ret;
761 
762 	if (tl_tpg->tl_nexus) {
763 		pr_debug("tl_tpg->tl_nexus already exists\n");
764 		return -EEXIST;
765 	}
766 
767 	tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
768 	if (!tl_nexus)
769 		return -ENOMEM;
770 
771 	tl_nexus->se_sess = target_alloc_session(&tl_tpg->tl_se_tpg, 0, 0,
772 					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
773 					name, tl_nexus, tcm_loop_alloc_sess_cb);
774 	if (IS_ERR(tl_nexus->se_sess)) {
775 		ret = PTR_ERR(tl_nexus->se_sess);
776 		kfree(tl_nexus);
777 		return ret;
778 	}
779 
780 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
781 		 tcm_loop_dump_proto_id(tl_hba), name);
782 	return 0;
783 }
784 
785 static int tcm_loop_drop_nexus(
786 	struct tcm_loop_tpg *tpg)
787 {
788 	struct se_session *se_sess;
789 	struct tcm_loop_nexus *tl_nexus;
790 
791 	tl_nexus = tpg->tl_nexus;
792 	if (!tl_nexus)
793 		return -ENODEV;
794 
795 	se_sess = tl_nexus->se_sess;
796 	if (!se_sess)
797 		return -ENODEV;
798 
799 	if (atomic_read(&tpg->tl_tpg_port_count)) {
800 		pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
801 		       atomic_read(&tpg->tl_tpg_port_count));
802 		return -EPERM;
803 	}
804 
805 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
806 		 tcm_loop_dump_proto_id(tpg->tl_hba),
807 		 tl_nexus->se_sess->se_node_acl->initiatorname);
808 	/*
809 	 * Release the SCSI I_T Nexus to the emulated Target Port
810 	 */
811 	transport_deregister_session(tl_nexus->se_sess);
812 	tpg->tl_nexus = NULL;
813 	kfree(tl_nexus);
814 	return 0;
815 }
816 
817 /* End items for tcm_loop_nexus_cit */
818 
819 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
820 {
821 	struct se_portal_group *se_tpg = to_tpg(item);
822 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
823 			struct tcm_loop_tpg, tl_se_tpg);
824 	struct tcm_loop_nexus *tl_nexus;
825 	ssize_t ret;
826 
827 	tl_nexus = tl_tpg->tl_nexus;
828 	if (!tl_nexus)
829 		return -ENODEV;
830 
831 	ret = snprintf(page, PAGE_SIZE, "%s\n",
832 		tl_nexus->se_sess->se_node_acl->initiatorname);
833 
834 	return ret;
835 }
836 
837 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
838 		const char *page, size_t count)
839 {
840 	struct se_portal_group *se_tpg = to_tpg(item);
841 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
842 			struct tcm_loop_tpg, tl_se_tpg);
843 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
844 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
845 	int ret;
846 	/*
847 	 * Shutdown the active I_T nexus if 'NULL' is passed..
848 	 */
849 	if (!strncmp(page, "NULL", 4)) {
850 		ret = tcm_loop_drop_nexus(tl_tpg);
851 		return (!ret) ? count : ret;
852 	}
853 	/*
854 	 * Otherwise make sure the passed virtual Initiator port WWN matches
855 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
856 	 * tcm_loop_make_nexus()
857 	 */
858 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
859 		pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
860 		       page, TL_WWN_ADDR_LEN);
861 		return -EINVAL;
862 	}
863 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
864 
865 	ptr = strstr(i_port, "naa.");
866 	if (ptr) {
867 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
868 			pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
869 			       i_port, tcm_loop_dump_proto_id(tl_hba));
870 			return -EINVAL;
871 		}
872 		port_ptr = &i_port[0];
873 		goto check_newline;
874 	}
875 	ptr = strstr(i_port, "fc.");
876 	if (ptr) {
877 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
878 			pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
879 			       i_port, tcm_loop_dump_proto_id(tl_hba));
880 			return -EINVAL;
881 		}
882 		port_ptr = &i_port[3]; /* Skip over "fc." */
883 		goto check_newline;
884 	}
885 	ptr = strstr(i_port, "iqn.");
886 	if (ptr) {
887 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
888 			pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
889 			       i_port, tcm_loop_dump_proto_id(tl_hba));
890 			return -EINVAL;
891 		}
892 		port_ptr = &i_port[0];
893 		goto check_newline;
894 	}
895 	pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
896 	       i_port);
897 	return -EINVAL;
898 	/*
899 	 * Clear any trailing newline for the NAA WWN
900 	 */
901 check_newline:
902 	if (i_port[strlen(i_port)-1] == '\n')
903 		i_port[strlen(i_port)-1] = '\0';
904 
905 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
906 	if (ret < 0)
907 		return ret;
908 
909 	return count;
910 }
911 
912 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
913 		char *page)
914 {
915 	struct se_portal_group *se_tpg = to_tpg(item);
916 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
917 			struct tcm_loop_tpg, tl_se_tpg);
918 	const char *status = NULL;
919 	ssize_t ret = -EINVAL;
920 
921 	switch (tl_tpg->tl_transport_status) {
922 	case TCM_TRANSPORT_ONLINE:
923 		status = "online";
924 		break;
925 	case TCM_TRANSPORT_OFFLINE:
926 		status = "offline";
927 		break;
928 	default:
929 		break;
930 	}
931 
932 	if (status)
933 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
934 
935 	return ret;
936 }
937 
938 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
939 		const char *page, size_t count)
940 {
941 	struct se_portal_group *se_tpg = to_tpg(item);
942 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
943 			struct tcm_loop_tpg, tl_se_tpg);
944 
945 	if (!strncmp(page, "online", 6)) {
946 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
947 		return count;
948 	}
949 	if (!strncmp(page, "offline", 7)) {
950 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
951 		if (tl_tpg->tl_nexus) {
952 			struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
953 
954 			core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
955 		}
956 		return count;
957 	}
958 	return -EINVAL;
959 }
960 
961 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
962 					 char *page)
963 {
964 	struct se_portal_group *se_tpg = to_tpg(item);
965 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
966 			struct tcm_loop_tpg, tl_se_tpg);
967 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
968 
969 	return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
970 			tl_hba->sh->host_no, tl_tpg->tl_tpgt);
971 }
972 
973 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
974 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
975 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
976 
977 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
978 	&tcm_loop_tpg_attr_nexus,
979 	&tcm_loop_tpg_attr_transport_status,
980 	&tcm_loop_tpg_attr_address,
981 	NULL,
982 };
983 
984 /* Start items for tcm_loop_naa_cit */
985 
986 static struct se_portal_group *tcm_loop_make_naa_tpg(
987 	struct se_wwn *wwn,
988 	struct config_group *group,
989 	const char *name)
990 {
991 	struct tcm_loop_hba *tl_hba = container_of(wwn,
992 			struct tcm_loop_hba, tl_hba_wwn);
993 	struct tcm_loop_tpg *tl_tpg;
994 	int ret;
995 	unsigned long tpgt;
996 
997 	if (strstr(name, "tpgt_") != name) {
998 		pr_err("Unable to locate \"tpgt_#\" directory group\n");
999 		return ERR_PTR(-EINVAL);
1000 	}
1001 	if (kstrtoul(name+5, 10, &tpgt))
1002 		return ERR_PTR(-EINVAL);
1003 
1004 	if (tpgt >= TL_TPGS_PER_HBA) {
1005 		pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
1006 		       tpgt, TL_TPGS_PER_HBA);
1007 		return ERR_PTR(-EINVAL);
1008 	}
1009 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1010 	tl_tpg->tl_hba = tl_hba;
1011 	tl_tpg->tl_tpgt = tpgt;
1012 	/*
1013 	 * Register the tl_tpg as a emulated TCM Target Endpoint
1014 	 */
1015 	ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
1016 	if (ret < 0)
1017 		return ERR_PTR(-ENOMEM);
1018 
1019 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
1020 		 tcm_loop_dump_proto_id(tl_hba),
1021 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1022 	return &tl_tpg->tl_se_tpg;
1023 }
1024 
1025 static void tcm_loop_drop_naa_tpg(
1026 	struct se_portal_group *se_tpg)
1027 {
1028 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1029 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1030 				struct tcm_loop_tpg, tl_se_tpg);
1031 	struct tcm_loop_hba *tl_hba;
1032 	unsigned short tpgt;
1033 
1034 	tl_hba = tl_tpg->tl_hba;
1035 	tpgt = tl_tpg->tl_tpgt;
1036 	/*
1037 	 * Release the I_T Nexus for the Virtual target link if present
1038 	 */
1039 	tcm_loop_drop_nexus(tl_tpg);
1040 	/*
1041 	 * Deregister the tl_tpg as a emulated TCM Target Endpoint
1042 	 */
1043 	core_tpg_deregister(se_tpg);
1044 
1045 	tl_tpg->tl_hba = NULL;
1046 	tl_tpg->tl_tpgt = 0;
1047 
1048 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
1049 		 tcm_loop_dump_proto_id(tl_hba),
1050 		 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1051 }
1052 
1053 /* End items for tcm_loop_naa_cit */
1054 
1055 /* Start items for tcm_loop_cit */
1056 
1057 static struct se_wwn *tcm_loop_make_scsi_hba(
1058 	struct target_fabric_configfs *tf,
1059 	struct config_group *group,
1060 	const char *name)
1061 {
1062 	struct tcm_loop_hba *tl_hba;
1063 	struct Scsi_Host *sh;
1064 	char *ptr;
1065 	int ret, off = 0;
1066 
1067 	tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
1068 	if (!tl_hba)
1069 		return ERR_PTR(-ENOMEM);
1070 
1071 	/*
1072 	 * Determine the emulated Protocol Identifier and Target Port Name
1073 	 * based on the incoming configfs directory name.
1074 	 */
1075 	ptr = strstr(name, "naa.");
1076 	if (ptr) {
1077 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1078 		goto check_len;
1079 	}
1080 	ptr = strstr(name, "fc.");
1081 	if (ptr) {
1082 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1083 		off = 3; /* Skip over "fc." */
1084 		goto check_len;
1085 	}
1086 	ptr = strstr(name, "iqn.");
1087 	if (!ptr) {
1088 		pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1089 		       name);
1090 		ret = -EINVAL;
1091 		goto out;
1092 	}
1093 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1094 
1095 check_len:
1096 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1097 		pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1098 		       name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1099 		ret = -EINVAL;
1100 		goto out;
1101 	}
1102 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1103 
1104 	/*
1105 	 * Call device_register(tl_hba->dev) to register the emulated
1106 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1107 	 * device_register() callbacks in tcm_loop_driver_probe()
1108 	 */
1109 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1110 	if (ret)
1111 		goto out;
1112 
1113 	sh = tl_hba->sh;
1114 	tcm_loop_hba_no_cnt++;
1115 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1116 		 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1117 	return &tl_hba->tl_hba_wwn;
1118 out:
1119 	kfree(tl_hba);
1120 	return ERR_PTR(ret);
1121 }
1122 
1123 static void tcm_loop_drop_scsi_hba(
1124 	struct se_wwn *wwn)
1125 {
1126 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1127 				struct tcm_loop_hba, tl_hba_wwn);
1128 
1129 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1130 		 tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1131 		 tl_hba->sh->host_no);
1132 	/*
1133 	 * Call device_unregister() on the original tl_hba->dev.
1134 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1135 	 * release *tl_hba;
1136 	 */
1137 	device_unregister(&tl_hba->dev);
1138 }
1139 
1140 /* Start items for tcm_loop_cit */
1141 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1142 {
1143 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1144 }
1145 
1146 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1147 
1148 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1149 	&tcm_loop_wwn_attr_version,
1150 	NULL,
1151 };
1152 
1153 /* End items for tcm_loop_cit */
1154 
1155 static const struct target_core_fabric_ops loop_ops = {
1156 	.module				= THIS_MODULE,
1157 	.name				= "loopback",
1158 	.get_fabric_name		= tcm_loop_get_fabric_name,
1159 	.tpg_get_wwn			= tcm_loop_get_endpoint_wwn,
1160 	.tpg_get_tag			= tcm_loop_get_tag,
1161 	.tpg_check_demo_mode		= tcm_loop_check_demo_mode,
1162 	.tpg_check_demo_mode_cache	= tcm_loop_check_demo_mode_cache,
1163 	.tpg_check_demo_mode_write_protect =
1164 				tcm_loop_check_demo_mode_write_protect,
1165 	.tpg_check_prod_mode_write_protect =
1166 				tcm_loop_check_prod_mode_write_protect,
1167 	.tpg_check_prot_fabric_only	= tcm_loop_check_prot_fabric_only,
1168 	.tpg_get_inst_index		= tcm_loop_get_inst_index,
1169 	.check_stop_free		= tcm_loop_check_stop_free,
1170 	.release_cmd			= tcm_loop_release_cmd,
1171 	.sess_get_index			= tcm_loop_sess_get_index,
1172 	.write_pending			= tcm_loop_write_pending,
1173 	.write_pending_status		= tcm_loop_write_pending_status,
1174 	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
1175 	.get_cmd_state			= tcm_loop_get_cmd_state,
1176 	.queue_data_in			= tcm_loop_queue_data_in,
1177 	.queue_status			= tcm_loop_queue_status,
1178 	.queue_tm_rsp			= tcm_loop_queue_tm_rsp,
1179 	.aborted_task			= tcm_loop_aborted_task,
1180 	.fabric_make_wwn		= tcm_loop_make_scsi_hba,
1181 	.fabric_drop_wwn		= tcm_loop_drop_scsi_hba,
1182 	.fabric_make_tpg		= tcm_loop_make_naa_tpg,
1183 	.fabric_drop_tpg		= tcm_loop_drop_naa_tpg,
1184 	.fabric_post_link		= tcm_loop_port_link,
1185 	.fabric_pre_unlink		= tcm_loop_port_unlink,
1186 	.tfc_wwn_attrs			= tcm_loop_wwn_attrs,
1187 	.tfc_tpg_base_attrs		= tcm_loop_tpg_attrs,
1188 	.tfc_tpg_attrib_attrs		= tcm_loop_tpg_attrib_attrs,
1189 };
1190 
1191 static int __init tcm_loop_fabric_init(void)
1192 {
1193 	int ret = -ENOMEM;
1194 
1195 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1196 	if (!tcm_loop_workqueue)
1197 		goto out;
1198 
1199 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1200 				sizeof(struct tcm_loop_cmd),
1201 				__alignof__(struct tcm_loop_cmd),
1202 				0, NULL);
1203 	if (!tcm_loop_cmd_cache) {
1204 		pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1205 		goto out_destroy_workqueue;
1206 	}
1207 
1208 	ret = tcm_loop_alloc_core_bus();
1209 	if (ret)
1210 		goto out_destroy_cache;
1211 
1212 	ret = target_register_template(&loop_ops);
1213 	if (ret)
1214 		goto out_release_core_bus;
1215 
1216 	return 0;
1217 
1218 out_release_core_bus:
1219 	tcm_loop_release_core_bus();
1220 out_destroy_cache:
1221 	kmem_cache_destroy(tcm_loop_cmd_cache);
1222 out_destroy_workqueue:
1223 	destroy_workqueue(tcm_loop_workqueue);
1224 out:
1225 	return ret;
1226 }
1227 
1228 static void __exit tcm_loop_fabric_exit(void)
1229 {
1230 	target_unregister_template(&loop_ops);
1231 	tcm_loop_release_core_bus();
1232 	kmem_cache_destroy(tcm_loop_cmd_cache);
1233 	destroy_workqueue(tcm_loop_workqueue);
1234 }
1235 
1236 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1237 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1238 MODULE_LICENSE("GPL");
1239 module_init(tcm_loop_fabric_init);
1240 module_exit(tcm_loop_fabric_exit);
1241