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 #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 /* Local pointer to allocated TCM configfs fabric module */
45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
46 
47 static struct workqueue_struct *tcm_loop_workqueue;
48 static struct kmem_cache *tcm_loop_cmd_cache;
49 
50 static int tcm_loop_hba_no_cnt;
51 
52 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
53 
54 /*
55  * Called from struct target_core_fabric_ops->check_stop_free()
56  */
57 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
58 {
59 	/*
60 	 * Do not release struct se_cmd's containing a valid TMR
61 	 * pointer.  These will be released directly in tcm_loop_device_reset()
62 	 * with transport_generic_free_cmd().
63 	 */
64 	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
65 		return 0;
66 	/*
67 	 * Release the struct se_cmd, which will make a callback to release
68 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
69 	 */
70 	transport_generic_free_cmd(se_cmd, 0);
71 	return 1;
72 }
73 
74 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
75 {
76 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
77 				struct tcm_loop_cmd, tl_se_cmd);
78 
79 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
80 }
81 
82 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
83 {
84 	seq_printf(m, "tcm_loop_proc_info()\n");
85 	return 0;
86 }
87 
88 static int tcm_loop_driver_probe(struct device *);
89 static int tcm_loop_driver_remove(struct device *);
90 
91 static int pseudo_lld_bus_match(struct device *dev,
92 				struct device_driver *dev_driver)
93 {
94 	return 1;
95 }
96 
97 static struct bus_type tcm_loop_lld_bus = {
98 	.name			= "tcm_loop_bus",
99 	.match			= pseudo_lld_bus_match,
100 	.probe			= tcm_loop_driver_probe,
101 	.remove			= tcm_loop_driver_remove,
102 };
103 
104 static struct device_driver tcm_loop_driverfs = {
105 	.name			= "tcm_loop",
106 	.bus			= &tcm_loop_lld_bus,
107 };
108 /*
109  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
110  */
111 struct device *tcm_loop_primary;
112 
113 /*
114  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
115  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
116  */
117 static int tcm_loop_change_queue_depth(
118 	struct scsi_device *sdev,
119 	int depth,
120 	int reason)
121 {
122 	switch (reason) {
123 	case SCSI_QDEPTH_DEFAULT:
124 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
125 		break;
126 	case SCSI_QDEPTH_QFULL:
127 		scsi_track_queue_full(sdev, depth);
128 		break;
129 	case SCSI_QDEPTH_RAMP_UP:
130 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
131 		break;
132 	default:
133 		return -EOPNOTSUPP;
134 	}
135 	return sdev->queue_depth;
136 }
137 
138 /*
139  * Locate the SAM Task Attr from struct scsi_cmnd *
140  */
141 static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
142 {
143 	if (sc->device->tagged_supported) {
144 		switch (sc->tag) {
145 		case HEAD_OF_QUEUE_TAG:
146 			return MSG_HEAD_TAG;
147 		case ORDERED_QUEUE_TAG:
148 			return MSG_ORDERED_TAG;
149 		default:
150 			break;
151 		}
152 	}
153 
154 	return MSG_SIMPLE_TAG;
155 }
156 
157 static void tcm_loop_submission_work(struct work_struct *work)
158 {
159 	struct tcm_loop_cmd *tl_cmd =
160 		container_of(work, struct tcm_loop_cmd, work);
161 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
162 	struct scsi_cmnd *sc = tl_cmd->sc;
163 	struct tcm_loop_nexus *tl_nexus;
164 	struct tcm_loop_hba *tl_hba;
165 	struct tcm_loop_tpg *tl_tpg;
166 	struct scatterlist *sgl_bidi = NULL;
167 	u32 sgl_bidi_count = 0;
168 	int rc;
169 
170 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
171 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
172 
173 	/*
174 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
175 	 * has already been configured via tcm_loop_make_naa_tpg().
176 	 */
177 	if (!tl_tpg->tl_hba) {
178 		set_host_byte(sc, DID_NO_CONNECT);
179 		goto out_done;
180 	}
181 
182 	tl_nexus = tl_hba->tl_nexus;
183 	if (!tl_nexus) {
184 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
185 				" does not exist\n");
186 		set_host_byte(sc, DID_ERROR);
187 		goto out_done;
188 	}
189 	if (scsi_bidi_cmnd(sc)) {
190 		struct scsi_data_buffer *sdb = scsi_in(sc);
191 
192 		sgl_bidi = sdb->table.sgl;
193 		sgl_bidi_count = sdb->table.nents;
194 		se_cmd->se_cmd_flags |= SCF_BIDI;
195 
196 	}
197 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
198 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
199 			scsi_bufflen(sc), tcm_loop_sam_attr(sc),
200 			sc->sc_data_direction, 0,
201 			scsi_sglist(sc), scsi_sg_count(sc),
202 			sgl_bidi, sgl_bidi_count);
203 	if (rc < 0) {
204 		set_host_byte(sc, DID_NO_CONNECT);
205 		goto out_done;
206 	}
207 	return;
208 
209 out_done:
210 	sc->scsi_done(sc);
211 	return;
212 }
213 
214 /*
215  * ->queuecommand can be and usually is called from interrupt context, so
216  * defer the actual submission to a workqueue.
217  */
218 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
219 {
220 	struct tcm_loop_cmd *tl_cmd;
221 
222 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
223 		" scsi_buf_len: %u\n", sc->device->host->host_no,
224 		sc->device->id, sc->device->channel, sc->device->lun,
225 		sc->cmnd[0], scsi_bufflen(sc));
226 
227 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
228 	if (!tl_cmd) {
229 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
230 		set_host_byte(sc, DID_ERROR);
231 		sc->scsi_done(sc);
232 		return 0;
233 	}
234 
235 	tl_cmd->sc = sc;
236 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
237 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
238 	return 0;
239 }
240 
241 /*
242  * Called from SCSI EH process context to issue a LUN_RESET TMR
243  * to struct scsi_device
244  */
245 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
246 {
247 	struct se_cmd *se_cmd = NULL;
248 	struct se_portal_group *se_tpg;
249 	struct se_session *se_sess;
250 	struct tcm_loop_cmd *tl_cmd = NULL;
251 	struct tcm_loop_hba *tl_hba;
252 	struct tcm_loop_nexus *tl_nexus;
253 	struct tcm_loop_tmr *tl_tmr = NULL;
254 	struct tcm_loop_tpg *tl_tpg;
255 	int ret = FAILED, rc;
256 	/*
257 	 * Locate the tcm_loop_hba_t pointer
258 	 */
259 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
260 	/*
261 	 * Locate the tl_nexus and se_sess pointers
262 	 */
263 	tl_nexus = tl_hba->tl_nexus;
264 	if (!tl_nexus) {
265 		pr_err("Unable to perform device reset without"
266 				" active I_T Nexus\n");
267 		return FAILED;
268 	}
269 	se_sess = tl_nexus->se_sess;
270 	/*
271 	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
272 	 */
273 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
274 	se_tpg = &tl_tpg->tl_se_tpg;
275 
276 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
277 	if (!tl_cmd) {
278 		pr_err("Unable to allocate memory for tl_cmd\n");
279 		return FAILED;
280 	}
281 
282 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
283 	if (!tl_tmr) {
284 		pr_err("Unable to allocate memory for tl_tmr\n");
285 		goto release;
286 	}
287 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
288 
289 	se_cmd = &tl_cmd->tl_se_cmd;
290 	/*
291 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
292 	 */
293 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
294 				DMA_NONE, MSG_SIMPLE_TAG,
295 				&tl_cmd->tl_sense_buf[0]);
296 
297 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
298 	if (rc < 0)
299 		goto release;
300 	/*
301 	 * Locate the underlying TCM struct se_lun from sc->device->lun
302 	 */
303 	if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
304 		goto release;
305 	/*
306 	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
307 	 * to wake us up.
308 	 */
309 	transport_generic_handle_tmr(se_cmd);
310 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
311 	/*
312 	 * The TMR LUN_RESET has completed, check the response status and
313 	 * then release allocations.
314 	 */
315 	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
316 		SUCCESS : FAILED;
317 release:
318 	if (se_cmd)
319 		transport_generic_free_cmd(se_cmd, 1);
320 	else
321 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
322 	kfree(tl_tmr);
323 	return ret;
324 }
325 
326 static int tcm_loop_slave_alloc(struct scsi_device *sd)
327 {
328 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
329 	return 0;
330 }
331 
332 static int tcm_loop_slave_configure(struct scsi_device *sd)
333 {
334 	return 0;
335 }
336 
337 static struct scsi_host_template tcm_loop_driver_template = {
338 	.show_info		= tcm_loop_show_info,
339 	.proc_name		= "tcm_loopback",
340 	.name			= "TCM_Loopback",
341 	.queuecommand		= tcm_loop_queuecommand,
342 	.change_queue_depth	= tcm_loop_change_queue_depth,
343 	.eh_device_reset_handler = tcm_loop_device_reset,
344 	.can_queue		= 1024,
345 	.this_id		= -1,
346 	.sg_tablesize		= 256,
347 	.cmd_per_lun		= 1024,
348 	.max_sectors		= 0xFFFF,
349 	.use_clustering		= DISABLE_CLUSTERING,
350 	.slave_alloc		= tcm_loop_slave_alloc,
351 	.slave_configure	= tcm_loop_slave_configure,
352 	.module			= THIS_MODULE,
353 };
354 
355 static int tcm_loop_driver_probe(struct device *dev)
356 {
357 	struct tcm_loop_hba *tl_hba;
358 	struct Scsi_Host *sh;
359 	int error;
360 
361 	tl_hba = to_tcm_loop_hba(dev);
362 
363 	sh = scsi_host_alloc(&tcm_loop_driver_template,
364 			sizeof(struct tcm_loop_hba));
365 	if (!sh) {
366 		pr_err("Unable to allocate struct scsi_host\n");
367 		return -ENODEV;
368 	}
369 	tl_hba->sh = sh;
370 
371 	/*
372 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
373 	 */
374 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
375 	/*
376 	 * Setup single ID, Channel and LUN for now..
377 	 */
378 	sh->max_id = 2;
379 	sh->max_lun = 0;
380 	sh->max_channel = 0;
381 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
382 
383 	error = scsi_add_host(sh, &tl_hba->dev);
384 	if (error) {
385 		pr_err("%s: scsi_add_host failed\n", __func__);
386 		scsi_host_put(sh);
387 		return -ENODEV;
388 	}
389 	return 0;
390 }
391 
392 static int tcm_loop_driver_remove(struct device *dev)
393 {
394 	struct tcm_loop_hba *tl_hba;
395 	struct Scsi_Host *sh;
396 
397 	tl_hba = to_tcm_loop_hba(dev);
398 	sh = tl_hba->sh;
399 
400 	scsi_remove_host(sh);
401 	scsi_host_put(sh);
402 	return 0;
403 }
404 
405 static void tcm_loop_release_adapter(struct device *dev)
406 {
407 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
408 
409 	kfree(tl_hba);
410 }
411 
412 /*
413  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
414  */
415 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
416 {
417 	int ret;
418 
419 	tl_hba->dev.bus = &tcm_loop_lld_bus;
420 	tl_hba->dev.parent = tcm_loop_primary;
421 	tl_hba->dev.release = &tcm_loop_release_adapter;
422 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
423 
424 	ret = device_register(&tl_hba->dev);
425 	if (ret) {
426 		pr_err("device_register() failed for"
427 				" tl_hba->dev: %d\n", ret);
428 		return -ENODEV;
429 	}
430 
431 	return 0;
432 }
433 
434 /*
435  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
436  * tcm_loop SCSI bus.
437  */
438 static int tcm_loop_alloc_core_bus(void)
439 {
440 	int ret;
441 
442 	tcm_loop_primary = root_device_register("tcm_loop_0");
443 	if (IS_ERR(tcm_loop_primary)) {
444 		pr_err("Unable to allocate tcm_loop_primary\n");
445 		return PTR_ERR(tcm_loop_primary);
446 	}
447 
448 	ret = bus_register(&tcm_loop_lld_bus);
449 	if (ret) {
450 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
451 		goto dev_unreg;
452 	}
453 
454 	ret = driver_register(&tcm_loop_driverfs);
455 	if (ret) {
456 		pr_err("driver_register() failed for"
457 				"tcm_loop_driverfs\n");
458 		goto bus_unreg;
459 	}
460 
461 	pr_debug("Initialized TCM Loop Core Bus\n");
462 	return ret;
463 
464 bus_unreg:
465 	bus_unregister(&tcm_loop_lld_bus);
466 dev_unreg:
467 	root_device_unregister(tcm_loop_primary);
468 	return ret;
469 }
470 
471 static void tcm_loop_release_core_bus(void)
472 {
473 	driver_unregister(&tcm_loop_driverfs);
474 	bus_unregister(&tcm_loop_lld_bus);
475 	root_device_unregister(tcm_loop_primary);
476 
477 	pr_debug("Releasing TCM Loop Core BUS\n");
478 }
479 
480 static char *tcm_loop_get_fabric_name(void)
481 {
482 	return "loopback";
483 }
484 
485 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
486 {
487 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
488 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
489 	/*
490 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
491 	 * time based on the protocol dependent prefix of the passed configfs group.
492 	 *
493 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
494 	 * ProtocolID using target_core_fabric_lib.c symbols.
495 	 */
496 	switch (tl_hba->tl_proto_id) {
497 	case SCSI_PROTOCOL_SAS:
498 		return sas_get_fabric_proto_ident(se_tpg);
499 	case SCSI_PROTOCOL_FCP:
500 		return fc_get_fabric_proto_ident(se_tpg);
501 	case SCSI_PROTOCOL_ISCSI:
502 		return iscsi_get_fabric_proto_ident(se_tpg);
503 	default:
504 		pr_err("Unknown tl_proto_id: 0x%02x, using"
505 			" SAS emulation\n", tl_hba->tl_proto_id);
506 		break;
507 	}
508 
509 	return sas_get_fabric_proto_ident(se_tpg);
510 }
511 
512 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
513 {
514 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
515 	/*
516 	 * Return the passed NAA identifier for the SAS Target Port
517 	 */
518 	return &tl_tpg->tl_hba->tl_wwn_address[0];
519 }
520 
521 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
522 {
523 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
524 	/*
525 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
526 	 * to represent the SCSI Target Port.
527 	 */
528 	return tl_tpg->tl_tpgt;
529 }
530 
531 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
532 {
533 	return 1;
534 }
535 
536 static u32 tcm_loop_get_pr_transport_id(
537 	struct se_portal_group *se_tpg,
538 	struct se_node_acl *se_nacl,
539 	struct t10_pr_registration *pr_reg,
540 	int *format_code,
541 	unsigned char *buf)
542 {
543 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
544 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
545 
546 	switch (tl_hba->tl_proto_id) {
547 	case SCSI_PROTOCOL_SAS:
548 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
549 					format_code, buf);
550 	case SCSI_PROTOCOL_FCP:
551 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
552 					format_code, buf);
553 	case SCSI_PROTOCOL_ISCSI:
554 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
555 					format_code, buf);
556 	default:
557 		pr_err("Unknown tl_proto_id: 0x%02x, using"
558 			" SAS emulation\n", tl_hba->tl_proto_id);
559 		break;
560 	}
561 
562 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
563 			format_code, buf);
564 }
565 
566 static u32 tcm_loop_get_pr_transport_id_len(
567 	struct se_portal_group *se_tpg,
568 	struct se_node_acl *se_nacl,
569 	struct t10_pr_registration *pr_reg,
570 	int *format_code)
571 {
572 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
573 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
574 
575 	switch (tl_hba->tl_proto_id) {
576 	case SCSI_PROTOCOL_SAS:
577 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
578 					format_code);
579 	case SCSI_PROTOCOL_FCP:
580 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
581 					format_code);
582 	case SCSI_PROTOCOL_ISCSI:
583 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
584 					format_code);
585 	default:
586 		pr_err("Unknown tl_proto_id: 0x%02x, using"
587 			" SAS emulation\n", tl_hba->tl_proto_id);
588 		break;
589 	}
590 
591 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
592 			format_code);
593 }
594 
595 /*
596  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
597  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
598  */
599 static char *tcm_loop_parse_pr_out_transport_id(
600 	struct se_portal_group *se_tpg,
601 	const char *buf,
602 	u32 *out_tid_len,
603 	char **port_nexus_ptr)
604 {
605 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
606 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
607 
608 	switch (tl_hba->tl_proto_id) {
609 	case SCSI_PROTOCOL_SAS:
610 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
611 					port_nexus_ptr);
612 	case SCSI_PROTOCOL_FCP:
613 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
614 					port_nexus_ptr);
615 	case SCSI_PROTOCOL_ISCSI:
616 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
617 					port_nexus_ptr);
618 	default:
619 		pr_err("Unknown tl_proto_id: 0x%02x, using"
620 			" SAS emulation\n", tl_hba->tl_proto_id);
621 		break;
622 	}
623 
624 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
625 			port_nexus_ptr);
626 }
627 
628 /*
629  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
630  * based upon the incoming fabric dependent SCSI Initiator Port
631  */
632 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
633 {
634 	return 1;
635 }
636 
637 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
638 {
639 	return 0;
640 }
641 
642 /*
643  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
644  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
645  */
646 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
647 {
648 	return 0;
649 }
650 
651 /*
652  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
653  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
654  * It has been added here as a nop for target_fabric_tf_ops_check()
655  */
656 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
657 {
658 	return 0;
659 }
660 
661 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
662 	struct se_portal_group *se_tpg)
663 {
664 	struct tcm_loop_nacl *tl_nacl;
665 
666 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
667 	if (!tl_nacl) {
668 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
669 		return NULL;
670 	}
671 
672 	return &tl_nacl->se_node_acl;
673 }
674 
675 static void tcm_loop_tpg_release_fabric_acl(
676 	struct se_portal_group *se_tpg,
677 	struct se_node_acl *se_nacl)
678 {
679 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
680 				struct tcm_loop_nacl, se_node_acl);
681 
682 	kfree(tl_nacl);
683 }
684 
685 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
686 {
687 	return 1;
688 }
689 
690 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
691 {
692 	return 1;
693 }
694 
695 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
696 {
697 	return;
698 }
699 
700 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
701 {
702 	return 1;
703 }
704 
705 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
706 {
707 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
708 			struct tcm_loop_cmd, tl_se_cmd);
709 
710 	return tl_cmd->sc_cmd_state;
711 }
712 
713 static int tcm_loop_shutdown_session(struct se_session *se_sess)
714 {
715 	return 0;
716 }
717 
718 static void tcm_loop_close_session(struct se_session *se_sess)
719 {
720 	return;
721 };
722 
723 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
724 {
725 	/*
726 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
727 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
728 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
729 	 * format with transport_generic_map_mem_to_cmd().
730 	 *
731 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
732 	 * object execution queue.
733 	 */
734 	target_execute_cmd(se_cmd);
735 	return 0;
736 }
737 
738 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
739 {
740 	return 0;
741 }
742 
743 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
744 {
745 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
746 				struct tcm_loop_cmd, tl_se_cmd);
747 	struct scsi_cmnd *sc = tl_cmd->sc;
748 
749 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
750 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
751 
752 	sc->result = SAM_STAT_GOOD;
753 	set_host_byte(sc, DID_OK);
754 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
755 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
756 		scsi_set_resid(sc, se_cmd->residual_count);
757 	sc->scsi_done(sc);
758 	return 0;
759 }
760 
761 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
762 {
763 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
764 				struct tcm_loop_cmd, tl_se_cmd);
765 	struct scsi_cmnd *sc = tl_cmd->sc;
766 
767 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
768 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
769 
770 	if (se_cmd->sense_buffer &&
771 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
772 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
773 
774 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
775 				SCSI_SENSE_BUFFERSIZE);
776 		sc->result = SAM_STAT_CHECK_CONDITION;
777 		set_driver_byte(sc, DRIVER_SENSE);
778 	} else
779 		sc->result = se_cmd->scsi_status;
780 
781 	set_host_byte(sc, DID_OK);
782 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
783 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
784 		scsi_set_resid(sc, se_cmd->residual_count);
785 	sc->scsi_done(sc);
786 	return 0;
787 }
788 
789 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
790 {
791 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
792 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
793 	/*
794 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
795 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
796 	 */
797 	atomic_set(&tl_tmr->tmr_complete, 1);
798 	wake_up(&tl_tmr->tl_tmr_wait);
799 }
800 
801 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
802 {
803 	switch (tl_hba->tl_proto_id) {
804 	case SCSI_PROTOCOL_SAS:
805 		return "SAS";
806 	case SCSI_PROTOCOL_FCP:
807 		return "FCP";
808 	case SCSI_PROTOCOL_ISCSI:
809 		return "iSCSI";
810 	default:
811 		break;
812 	}
813 
814 	return "Unknown";
815 }
816 
817 /* Start items for tcm_loop_port_cit */
818 
819 static int tcm_loop_port_link(
820 	struct se_portal_group *se_tpg,
821 	struct se_lun *lun)
822 {
823 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
824 				struct tcm_loop_tpg, tl_se_tpg);
825 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
826 
827 	atomic_inc(&tl_tpg->tl_tpg_port_count);
828 	smp_mb__after_atomic_inc();
829 	/*
830 	 * Add Linux/SCSI struct scsi_device by HCTL
831 	 */
832 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
833 
834 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
835 	return 0;
836 }
837 
838 static void tcm_loop_port_unlink(
839 	struct se_portal_group *se_tpg,
840 	struct se_lun *se_lun)
841 {
842 	struct scsi_device *sd;
843 	struct tcm_loop_hba *tl_hba;
844 	struct tcm_loop_tpg *tl_tpg;
845 
846 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
847 	tl_hba = tl_tpg->tl_hba;
848 
849 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
850 				se_lun->unpacked_lun);
851 	if (!sd) {
852 		pr_err("Unable to locate struct scsi_device for %d:%d:"
853 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
854 		return;
855 	}
856 	/*
857 	 * Remove Linux/SCSI struct scsi_device by HCTL
858 	 */
859 	scsi_remove_device(sd);
860 	scsi_device_put(sd);
861 
862 	atomic_dec(&tl_tpg->tl_tpg_port_count);
863 	smp_mb__after_atomic_dec();
864 
865 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
866 }
867 
868 /* End items for tcm_loop_port_cit */
869 
870 /* Start items for tcm_loop_nexus_cit */
871 
872 static int tcm_loop_make_nexus(
873 	struct tcm_loop_tpg *tl_tpg,
874 	const char *name)
875 {
876 	struct se_portal_group *se_tpg;
877 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
878 	struct tcm_loop_nexus *tl_nexus;
879 	int ret = -ENOMEM;
880 
881 	if (tl_tpg->tl_hba->tl_nexus) {
882 		pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
883 		return -EEXIST;
884 	}
885 	se_tpg = &tl_tpg->tl_se_tpg;
886 
887 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
888 	if (!tl_nexus) {
889 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
890 		return -ENOMEM;
891 	}
892 	/*
893 	 * Initialize the struct se_session pointer
894 	 */
895 	tl_nexus->se_sess = transport_init_session();
896 	if (IS_ERR(tl_nexus->se_sess)) {
897 		ret = PTR_ERR(tl_nexus->se_sess);
898 		goto out;
899 	}
900 	/*
901 	 * Since we are running in 'demo mode' this call with generate a
902 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
903 	 * Initiator port name of the passed configfs group 'name'.
904 	 */
905 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
906 				se_tpg, (unsigned char *)name);
907 	if (!tl_nexus->se_sess->se_node_acl) {
908 		transport_free_session(tl_nexus->se_sess);
909 		goto out;
910 	}
911 	/*
912 	 * Now, register the SAS I_T Nexus as active with the call to
913 	 * transport_register_session()
914 	 */
915 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
916 			tl_nexus->se_sess, tl_nexus);
917 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
918 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
919 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
920 		name);
921 	return 0;
922 
923 out:
924 	kfree(tl_nexus);
925 	return ret;
926 }
927 
928 static int tcm_loop_drop_nexus(
929 	struct tcm_loop_tpg *tpg)
930 {
931 	struct se_session *se_sess;
932 	struct tcm_loop_nexus *tl_nexus;
933 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
934 
935 	tl_nexus = tpg->tl_hba->tl_nexus;
936 	if (!tl_nexus)
937 		return -ENODEV;
938 
939 	se_sess = tl_nexus->se_sess;
940 	if (!se_sess)
941 		return -ENODEV;
942 
943 	if (atomic_read(&tpg->tl_tpg_port_count)) {
944 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
945 			" active TPG port count: %d\n",
946 			atomic_read(&tpg->tl_tpg_port_count));
947 		return -EPERM;
948 	}
949 
950 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
951 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
952 		tl_nexus->se_sess->se_node_acl->initiatorname);
953 	/*
954 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
955 	 */
956 	transport_deregister_session(tl_nexus->se_sess);
957 	tpg->tl_hba->tl_nexus = NULL;
958 	kfree(tl_nexus);
959 	return 0;
960 }
961 
962 /* End items for tcm_loop_nexus_cit */
963 
964 static ssize_t tcm_loop_tpg_show_nexus(
965 	struct se_portal_group *se_tpg,
966 	char *page)
967 {
968 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
969 			struct tcm_loop_tpg, tl_se_tpg);
970 	struct tcm_loop_nexus *tl_nexus;
971 	ssize_t ret;
972 
973 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
974 	if (!tl_nexus)
975 		return -ENODEV;
976 
977 	ret = snprintf(page, PAGE_SIZE, "%s\n",
978 		tl_nexus->se_sess->se_node_acl->initiatorname);
979 
980 	return ret;
981 }
982 
983 static ssize_t tcm_loop_tpg_store_nexus(
984 	struct se_portal_group *se_tpg,
985 	const char *page,
986 	size_t count)
987 {
988 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
989 			struct tcm_loop_tpg, tl_se_tpg);
990 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
991 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
992 	int ret;
993 	/*
994 	 * Shutdown the active I_T nexus if 'NULL' is passed..
995 	 */
996 	if (!strncmp(page, "NULL", 4)) {
997 		ret = tcm_loop_drop_nexus(tl_tpg);
998 		return (!ret) ? count : ret;
999 	}
1000 	/*
1001 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1002 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1003 	 * tcm_loop_make_nexus()
1004 	 */
1005 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1006 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1007 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1008 		return -EINVAL;
1009 	}
1010 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1011 
1012 	ptr = strstr(i_port, "naa.");
1013 	if (ptr) {
1014 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1015 			pr_err("Passed SAS Initiator Port %s does not"
1016 				" match target port protoid: %s\n", i_port,
1017 				tcm_loop_dump_proto_id(tl_hba));
1018 			return -EINVAL;
1019 		}
1020 		port_ptr = &i_port[0];
1021 		goto check_newline;
1022 	}
1023 	ptr = strstr(i_port, "fc.");
1024 	if (ptr) {
1025 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1026 			pr_err("Passed FCP Initiator Port %s does not"
1027 				" match target port protoid: %s\n", i_port,
1028 				tcm_loop_dump_proto_id(tl_hba));
1029 			return -EINVAL;
1030 		}
1031 		port_ptr = &i_port[3]; /* Skip over "fc." */
1032 		goto check_newline;
1033 	}
1034 	ptr = strstr(i_port, "iqn.");
1035 	if (ptr) {
1036 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1037 			pr_err("Passed iSCSI Initiator Port %s does not"
1038 				" match target port protoid: %s\n", i_port,
1039 				tcm_loop_dump_proto_id(tl_hba));
1040 			return -EINVAL;
1041 		}
1042 		port_ptr = &i_port[0];
1043 		goto check_newline;
1044 	}
1045 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1046 			" %s\n", i_port);
1047 	return -EINVAL;
1048 	/*
1049 	 * Clear any trailing newline for the NAA WWN
1050 	 */
1051 check_newline:
1052 	if (i_port[strlen(i_port)-1] == '\n')
1053 		i_port[strlen(i_port)-1] = '\0';
1054 
1055 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1056 	if (ret < 0)
1057 		return ret;
1058 
1059 	return count;
1060 }
1061 
1062 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1063 
1064 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1065 	&tcm_loop_tpg_nexus.attr,
1066 	NULL,
1067 };
1068 
1069 /* Start items for tcm_loop_naa_cit */
1070 
1071 struct se_portal_group *tcm_loop_make_naa_tpg(
1072 	struct se_wwn *wwn,
1073 	struct config_group *group,
1074 	const char *name)
1075 {
1076 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1077 			struct tcm_loop_hba, tl_hba_wwn);
1078 	struct tcm_loop_tpg *tl_tpg;
1079 	char *tpgt_str, *end_ptr;
1080 	int ret;
1081 	unsigned short int tpgt;
1082 
1083 	tpgt_str = strstr(name, "tpgt_");
1084 	if (!tpgt_str) {
1085 		pr_err("Unable to locate \"tpgt_#\" directory"
1086 				" group\n");
1087 		return ERR_PTR(-EINVAL);
1088 	}
1089 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1090 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1091 
1092 	if (tpgt >= TL_TPGS_PER_HBA) {
1093 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1094 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1095 		return ERR_PTR(-EINVAL);
1096 	}
1097 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1098 	tl_tpg->tl_hba = tl_hba;
1099 	tl_tpg->tl_tpgt = tpgt;
1100 	/*
1101 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1102 	 */
1103 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1104 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1105 			TRANSPORT_TPG_TYPE_NORMAL);
1106 	if (ret < 0)
1107 		return ERR_PTR(-ENOMEM);
1108 
1109 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1110 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1111 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1112 
1113 	return &tl_tpg->tl_se_tpg;
1114 }
1115 
1116 void tcm_loop_drop_naa_tpg(
1117 	struct se_portal_group *se_tpg)
1118 {
1119 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1120 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1121 				struct tcm_loop_tpg, tl_se_tpg);
1122 	struct tcm_loop_hba *tl_hba;
1123 	unsigned short tpgt;
1124 
1125 	tl_hba = tl_tpg->tl_hba;
1126 	tpgt = tl_tpg->tl_tpgt;
1127 	/*
1128 	 * Release the I_T Nexus for the Virtual SAS link if present
1129 	 */
1130 	tcm_loop_drop_nexus(tl_tpg);
1131 	/*
1132 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1133 	 */
1134 	core_tpg_deregister(se_tpg);
1135 
1136 	tl_tpg->tl_hba = NULL;
1137 	tl_tpg->tl_tpgt = 0;
1138 
1139 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1140 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1141 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1142 }
1143 
1144 /* End items for tcm_loop_naa_cit */
1145 
1146 /* Start items for tcm_loop_cit */
1147 
1148 struct se_wwn *tcm_loop_make_scsi_hba(
1149 	struct target_fabric_configfs *tf,
1150 	struct config_group *group,
1151 	const char *name)
1152 {
1153 	struct tcm_loop_hba *tl_hba;
1154 	struct Scsi_Host *sh;
1155 	char *ptr;
1156 	int ret, off = 0;
1157 
1158 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1159 	if (!tl_hba) {
1160 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1161 		return ERR_PTR(-ENOMEM);
1162 	}
1163 	/*
1164 	 * Determine the emulated Protocol Identifier and Target Port Name
1165 	 * based on the incoming configfs directory name.
1166 	 */
1167 	ptr = strstr(name, "naa.");
1168 	if (ptr) {
1169 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1170 		goto check_len;
1171 	}
1172 	ptr = strstr(name, "fc.");
1173 	if (ptr) {
1174 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1175 		off = 3; /* Skip over "fc." */
1176 		goto check_len;
1177 	}
1178 	ptr = strstr(name, "iqn.");
1179 	if (!ptr) {
1180 		pr_err("Unable to locate prefix for emulated Target "
1181 				"Port: %s\n", name);
1182 		ret = -EINVAL;
1183 		goto out;
1184 	}
1185 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1186 
1187 check_len:
1188 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1189 		pr_err("Emulated NAA %s Address: %s, exceeds"
1190 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1191 			TL_WWN_ADDR_LEN);
1192 		ret = -EINVAL;
1193 		goto out;
1194 	}
1195 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1196 
1197 	/*
1198 	 * Call device_register(tl_hba->dev) to register the emulated
1199 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1200 	 * device_register() callbacks in tcm_loop_driver_probe()
1201 	 */
1202 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1203 	if (ret)
1204 		goto out;
1205 
1206 	sh = tl_hba->sh;
1207 	tcm_loop_hba_no_cnt++;
1208 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1209 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1210 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1211 
1212 	return &tl_hba->tl_hba_wwn;
1213 out:
1214 	kfree(tl_hba);
1215 	return ERR_PTR(ret);
1216 }
1217 
1218 void tcm_loop_drop_scsi_hba(
1219 	struct se_wwn *wwn)
1220 {
1221 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1222 				struct tcm_loop_hba, tl_hba_wwn);
1223 
1224 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1225 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1226 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1227 	/*
1228 	 * Call device_unregister() on the original tl_hba->dev.
1229 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1230 	 * release *tl_hba;
1231 	 */
1232 	device_unregister(&tl_hba->dev);
1233 }
1234 
1235 /* Start items for tcm_loop_cit */
1236 static ssize_t tcm_loop_wwn_show_attr_version(
1237 	struct target_fabric_configfs *tf,
1238 	char *page)
1239 {
1240 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1241 }
1242 
1243 TF_WWN_ATTR_RO(tcm_loop, version);
1244 
1245 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1246 	&tcm_loop_wwn_version.attr,
1247 	NULL,
1248 };
1249 
1250 /* End items for tcm_loop_cit */
1251 
1252 static int tcm_loop_register_configfs(void)
1253 {
1254 	struct target_fabric_configfs *fabric;
1255 	int ret;
1256 	/*
1257 	 * Set the TCM Loop HBA counter to zero
1258 	 */
1259 	tcm_loop_hba_no_cnt = 0;
1260 	/*
1261 	 * Register the top level struct config_item_type with TCM core
1262 	 */
1263 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1264 	if (IS_ERR(fabric)) {
1265 		pr_err("tcm_loop_register_configfs() failed!\n");
1266 		return PTR_ERR(fabric);
1267 	}
1268 	/*
1269 	 * Setup the fabric API of function pointers used by target_core_mod
1270 	 */
1271 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1272 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1273 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1274 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1275 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1276 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1277 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1278 					&tcm_loop_get_pr_transport_id_len;
1279 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1280 					&tcm_loop_parse_pr_out_transport_id;
1281 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1282 	fabric->tf_ops.tpg_check_demo_mode_cache =
1283 					&tcm_loop_check_demo_mode_cache;
1284 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1285 					&tcm_loop_check_demo_mode_write_protect;
1286 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1287 					&tcm_loop_check_prod_mode_write_protect;
1288 	/*
1289 	 * The TCM loopback fabric module runs in demo-mode to a local
1290 	 * virtual SCSI device, so fabric dependent initator ACLs are
1291 	 * not required.
1292 	 */
1293 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1294 	fabric->tf_ops.tpg_release_fabric_acl =
1295 					&tcm_loop_tpg_release_fabric_acl;
1296 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1297 	/*
1298 	 * Used for setting up remaining TCM resources in process context
1299 	 */
1300 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1301 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1302 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1303 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1304 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1305 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1306 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1307 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1308 	/*
1309 	 * Not used for TCM loopback
1310 	 */
1311 	fabric->tf_ops.set_default_node_attributes =
1312 					&tcm_loop_set_default_node_attributes;
1313 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1314 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1315 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1316 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1317 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1318 
1319 	/*
1320 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1321 	 */
1322 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1323 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1324 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1325 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1326 	/*
1327 	 * fabric_post_link() and fabric_pre_unlink() are used for
1328 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1329 	 */
1330 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1331 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1332 	fabric->tf_ops.fabric_make_np = NULL;
1333 	fabric->tf_ops.fabric_drop_np = NULL;
1334 	/*
1335 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1336 	 */
1337 	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1338 	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1339 	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1340 	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1341 	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1342 	/*
1343 	 * Once fabric->tf_ops has been setup, now register the fabric for
1344 	 * use within TCM
1345 	 */
1346 	ret = target_fabric_configfs_register(fabric);
1347 	if (ret < 0) {
1348 		pr_err("target_fabric_configfs_register() for"
1349 				" TCM_Loop failed!\n");
1350 		target_fabric_configfs_free(fabric);
1351 		return -1;
1352 	}
1353 	/*
1354 	 * Setup our local pointer to *fabric.
1355 	 */
1356 	tcm_loop_fabric_configfs = fabric;
1357 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1358 			" tcm_loop_fabric_configfs\n");
1359 	return 0;
1360 }
1361 
1362 static void tcm_loop_deregister_configfs(void)
1363 {
1364 	if (!tcm_loop_fabric_configfs)
1365 		return;
1366 
1367 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1368 	tcm_loop_fabric_configfs = NULL;
1369 	pr_debug("TCM_LOOP[0] - Cleared"
1370 				" tcm_loop_fabric_configfs\n");
1371 }
1372 
1373 static int __init tcm_loop_fabric_init(void)
1374 {
1375 	int ret = -ENOMEM;
1376 
1377 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1378 	if (!tcm_loop_workqueue)
1379 		goto out;
1380 
1381 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1382 				sizeof(struct tcm_loop_cmd),
1383 				__alignof__(struct tcm_loop_cmd),
1384 				0, NULL);
1385 	if (!tcm_loop_cmd_cache) {
1386 		pr_debug("kmem_cache_create() for"
1387 			" tcm_loop_cmd_cache failed\n");
1388 		goto out_destroy_workqueue;
1389 	}
1390 
1391 	ret = tcm_loop_alloc_core_bus();
1392 	if (ret)
1393 		goto out_destroy_cache;
1394 
1395 	ret = tcm_loop_register_configfs();
1396 	if (ret)
1397 		goto out_release_core_bus;
1398 
1399 	return 0;
1400 
1401 out_release_core_bus:
1402 	tcm_loop_release_core_bus();
1403 out_destroy_cache:
1404 	kmem_cache_destroy(tcm_loop_cmd_cache);
1405 out_destroy_workqueue:
1406 	destroy_workqueue(tcm_loop_workqueue);
1407 out:
1408 	return ret;
1409 }
1410 
1411 static void __exit tcm_loop_fabric_exit(void)
1412 {
1413 	tcm_loop_deregister_configfs();
1414 	tcm_loop_release_core_bus();
1415 	kmem_cache_destroy(tcm_loop_cmd_cache);
1416 	destroy_workqueue(tcm_loop_workqueue);
1417 }
1418 
1419 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1420 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1421 MODULE_LICENSE("GPL");
1422 module_init(tcm_loop_fabric_init);
1423 module_exit(tcm_loop_fabric_exit);
1424