xref: /openbmc/linux/drivers/target/loopback/tcm_loop.c (revision 6c9e92476bc924ede6d6d2f0bfed2c06ae148d29)
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 static void tcm_loop_submission_work(struct work_struct *work)
114 {
115 	struct tcm_loop_cmd *tl_cmd =
116 		container_of(work, struct tcm_loop_cmd, work);
117 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
118 	struct scsi_cmnd *sc = tl_cmd->sc;
119 	struct tcm_loop_nexus *tl_nexus;
120 	struct tcm_loop_hba *tl_hba;
121 	struct tcm_loop_tpg *tl_tpg;
122 	struct scatterlist *sgl_bidi = NULL;
123 	u32 sgl_bidi_count = 0, transfer_length;
124 	int rc;
125 
126 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
127 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
128 
129 	/*
130 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
131 	 * has already been configured via tcm_loop_make_naa_tpg().
132 	 */
133 	if (!tl_tpg->tl_hba) {
134 		set_host_byte(sc, DID_NO_CONNECT);
135 		goto out_done;
136 	}
137 	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
138 		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
139 		goto out_done;
140 	}
141 	tl_nexus = tl_hba->tl_nexus;
142 	if (!tl_nexus) {
143 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
144 				" does not exist\n");
145 		set_host_byte(sc, DID_ERROR);
146 		goto out_done;
147 	}
148 	if (scsi_bidi_cmnd(sc)) {
149 		struct scsi_data_buffer *sdb = scsi_in(sc);
150 
151 		sgl_bidi = sdb->table.sgl;
152 		sgl_bidi_count = sdb->table.nents;
153 		se_cmd->se_cmd_flags |= SCF_BIDI;
154 
155 	}
156 
157 	transfer_length = scsi_transfer_length(sc);
158 	if (!scsi_prot_sg_count(sc) &&
159 	    scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
160 		se_cmd->prot_pto = true;
161 		/*
162 		 * loopback transport doesn't support
163 		 * WRITE_GENERATE, READ_STRIP protection
164 		 * information operations, go ahead unprotected.
165 		 */
166 		transfer_length = scsi_bufflen(sc);
167 	}
168 
169 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
170 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
171 			transfer_length, MSG_SIMPLE_TAG,
172 			sc->sc_data_direction, 0,
173 			scsi_sglist(sc), scsi_sg_count(sc),
174 			sgl_bidi, sgl_bidi_count,
175 			scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
176 	if (rc < 0) {
177 		set_host_byte(sc, DID_NO_CONNECT);
178 		goto out_done;
179 	}
180 	return;
181 
182 out_done:
183 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
184 	sc->scsi_done(sc);
185 	return;
186 }
187 
188 /*
189  * ->queuecommand can be and usually is called from interrupt context, so
190  * defer the actual submission to a workqueue.
191  */
192 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
193 {
194 	struct tcm_loop_cmd *tl_cmd;
195 
196 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%llu got CDB: 0x%02x"
197 		" scsi_buf_len: %u\n", sc->device->host->host_no,
198 		sc->device->id, sc->device->channel, sc->device->lun,
199 		sc->cmnd[0], scsi_bufflen(sc));
200 
201 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
202 	if (!tl_cmd) {
203 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
204 		set_host_byte(sc, DID_ERROR);
205 		sc->scsi_done(sc);
206 		return 0;
207 	}
208 
209 	tl_cmd->sc = sc;
210 	tl_cmd->sc_cmd_tag = sc->request->tag;
211 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
212 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
213 	return 0;
214 }
215 
216 /*
217  * Called from SCSI EH process context to issue a LUN_RESET TMR
218  * to struct scsi_device
219  */
220 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
221 			      struct tcm_loop_nexus *tl_nexus,
222 			      int lun, int task, enum tcm_tmreq_table tmr)
223 {
224 	struct se_cmd *se_cmd = NULL;
225 	struct se_session *se_sess;
226 	struct se_portal_group *se_tpg;
227 	struct tcm_loop_cmd *tl_cmd = NULL;
228 	struct tcm_loop_tmr *tl_tmr = NULL;
229 	int ret = TMR_FUNCTION_FAILED, rc;
230 
231 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
232 	if (!tl_cmd) {
233 		pr_err("Unable to allocate memory for tl_cmd\n");
234 		return ret;
235 	}
236 
237 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
238 	if (!tl_tmr) {
239 		pr_err("Unable to allocate memory for tl_tmr\n");
240 		goto release;
241 	}
242 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
243 
244 	se_cmd = &tl_cmd->tl_se_cmd;
245 	se_tpg = &tl_tpg->tl_se_tpg;
246 	se_sess = tl_nexus->se_sess;
247 	/*
248 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
249 	 */
250 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
251 				DMA_NONE, MSG_SIMPLE_TAG,
252 				&tl_cmd->tl_sense_buf[0]);
253 
254 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
255 	if (rc < 0)
256 		goto release;
257 
258 	if (tmr == TMR_ABORT_TASK)
259 		se_cmd->se_tmr_req->ref_task_tag = task;
260 
261 	/*
262 	 * Locate the underlying TCM struct se_lun
263 	 */
264 	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
265 		ret = TMR_LUN_DOES_NOT_EXIST;
266 		goto release;
267 	}
268 	/*
269 	 * Queue the TMR to TCM Core and sleep waiting for
270 	 * tcm_loop_queue_tm_rsp() to wake us up.
271 	 */
272 	transport_generic_handle_tmr(se_cmd);
273 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
274 	/*
275 	 * The TMR LUN_RESET has completed, check the response status and
276 	 * then release allocations.
277 	 */
278 	ret = se_cmd->se_tmr_req->response;
279 release:
280 	if (se_cmd)
281 		transport_generic_free_cmd(se_cmd, 1);
282 	else
283 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
284 	kfree(tl_tmr);
285 	return ret;
286 }
287 
288 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
289 {
290 	struct tcm_loop_hba *tl_hba;
291 	struct tcm_loop_nexus *tl_nexus;
292 	struct tcm_loop_tpg *tl_tpg;
293 	int ret = FAILED;
294 
295 	/*
296 	 * Locate the tcm_loop_hba_t pointer
297 	 */
298 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
299 	/*
300 	 * Locate the tl_nexus and se_sess pointers
301 	 */
302 	tl_nexus = tl_hba->tl_nexus;
303 	if (!tl_nexus) {
304 		pr_err("Unable to perform device reset without"
305 				" active I_T Nexus\n");
306 		return FAILED;
307 	}
308 
309 	/*
310 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
311 	 */
312 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
313 	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
314 				 sc->request->tag, TMR_ABORT_TASK);
315 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
316 }
317 
318 /*
319  * Called from SCSI EH process context to issue a LUN_RESET TMR
320  * to struct scsi_device
321  */
322 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
323 {
324 	struct tcm_loop_hba *tl_hba;
325 	struct tcm_loop_nexus *tl_nexus;
326 	struct tcm_loop_tpg *tl_tpg;
327 	int ret = FAILED;
328 
329 	/*
330 	 * Locate the tcm_loop_hba_t pointer
331 	 */
332 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
333 	/*
334 	 * Locate the tl_nexus and se_sess pointers
335 	 */
336 	tl_nexus = tl_hba->tl_nexus;
337 	if (!tl_nexus) {
338 		pr_err("Unable to perform device reset without"
339 				" active I_T Nexus\n");
340 		return FAILED;
341 	}
342 	/*
343 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
344 	 */
345 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
346 	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
347 				 0, TMR_LUN_RESET);
348 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
349 }
350 
351 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
352 {
353 	struct tcm_loop_hba *tl_hba;
354 	struct tcm_loop_tpg *tl_tpg;
355 
356 	/*
357 	 * Locate the tcm_loop_hba_t pointer
358 	 */
359 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
360 	if (!tl_hba) {
361 		pr_err("Unable to perform device reset without"
362 				" active I_T Nexus\n");
363 		return FAILED;
364 	}
365 	/*
366 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
367 	 */
368 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
369 	if (tl_tpg) {
370 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
371 		return SUCCESS;
372 	}
373 	return FAILED;
374 }
375 
376 static int tcm_loop_slave_alloc(struct scsi_device *sd)
377 {
378 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
379 	return 0;
380 }
381 
382 static struct scsi_host_template tcm_loop_driver_template = {
383 	.show_info		= tcm_loop_show_info,
384 	.proc_name		= "tcm_loopback",
385 	.name			= "TCM_Loopback",
386 	.queuecommand		= tcm_loop_queuecommand,
387 	.change_queue_depth	= scsi_change_queue_depth,
388 	.change_queue_type	= scsi_change_queue_type,
389 	.eh_abort_handler = tcm_loop_abort_task,
390 	.eh_device_reset_handler = tcm_loop_device_reset,
391 	.eh_target_reset_handler = tcm_loop_target_reset,
392 	.can_queue		= 1024,
393 	.this_id		= -1,
394 	.sg_tablesize		= 256,
395 	.cmd_per_lun		= 1024,
396 	.max_sectors		= 0xFFFF,
397 	.use_clustering		= DISABLE_CLUSTERING,
398 	.slave_alloc		= tcm_loop_slave_alloc,
399 	.module			= THIS_MODULE,
400 	.use_blk_tags		= 1,
401 	.track_queue_depth	= 1,
402 };
403 
404 static int tcm_loop_driver_probe(struct device *dev)
405 {
406 	struct tcm_loop_hba *tl_hba;
407 	struct Scsi_Host *sh;
408 	int error, host_prot;
409 
410 	tl_hba = to_tcm_loop_hba(dev);
411 
412 	sh = scsi_host_alloc(&tcm_loop_driver_template,
413 			sizeof(struct tcm_loop_hba));
414 	if (!sh) {
415 		pr_err("Unable to allocate struct scsi_host\n");
416 		return -ENODEV;
417 	}
418 	tl_hba->sh = sh;
419 
420 	/*
421 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
422 	 */
423 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
424 	/*
425 	 * Setup single ID, Channel and LUN for now..
426 	 */
427 	sh->max_id = 2;
428 	sh->max_lun = 0;
429 	sh->max_channel = 0;
430 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
431 
432 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
433 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
434 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
435 
436 	scsi_host_set_prot(sh, host_prot);
437 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
438 
439 	error = scsi_add_host(sh, &tl_hba->dev);
440 	if (error) {
441 		pr_err("%s: scsi_add_host failed\n", __func__);
442 		scsi_host_put(sh);
443 		return -ENODEV;
444 	}
445 	return 0;
446 }
447 
448 static int tcm_loop_driver_remove(struct device *dev)
449 {
450 	struct tcm_loop_hba *tl_hba;
451 	struct Scsi_Host *sh;
452 
453 	tl_hba = to_tcm_loop_hba(dev);
454 	sh = tl_hba->sh;
455 
456 	scsi_remove_host(sh);
457 	scsi_host_put(sh);
458 	return 0;
459 }
460 
461 static void tcm_loop_release_adapter(struct device *dev)
462 {
463 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
464 
465 	kfree(tl_hba);
466 }
467 
468 /*
469  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
470  */
471 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
472 {
473 	int ret;
474 
475 	tl_hba->dev.bus = &tcm_loop_lld_bus;
476 	tl_hba->dev.parent = tcm_loop_primary;
477 	tl_hba->dev.release = &tcm_loop_release_adapter;
478 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
479 
480 	ret = device_register(&tl_hba->dev);
481 	if (ret) {
482 		pr_err("device_register() failed for"
483 				" tl_hba->dev: %d\n", ret);
484 		return -ENODEV;
485 	}
486 
487 	return 0;
488 }
489 
490 /*
491  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
492  * tcm_loop SCSI bus.
493  */
494 static int tcm_loop_alloc_core_bus(void)
495 {
496 	int ret;
497 
498 	tcm_loop_primary = root_device_register("tcm_loop_0");
499 	if (IS_ERR(tcm_loop_primary)) {
500 		pr_err("Unable to allocate tcm_loop_primary\n");
501 		return PTR_ERR(tcm_loop_primary);
502 	}
503 
504 	ret = bus_register(&tcm_loop_lld_bus);
505 	if (ret) {
506 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
507 		goto dev_unreg;
508 	}
509 
510 	ret = driver_register(&tcm_loop_driverfs);
511 	if (ret) {
512 		pr_err("driver_register() failed for"
513 				"tcm_loop_driverfs\n");
514 		goto bus_unreg;
515 	}
516 
517 	pr_debug("Initialized TCM Loop Core Bus\n");
518 	return ret;
519 
520 bus_unreg:
521 	bus_unregister(&tcm_loop_lld_bus);
522 dev_unreg:
523 	root_device_unregister(tcm_loop_primary);
524 	return ret;
525 }
526 
527 static void tcm_loop_release_core_bus(void)
528 {
529 	driver_unregister(&tcm_loop_driverfs);
530 	bus_unregister(&tcm_loop_lld_bus);
531 	root_device_unregister(tcm_loop_primary);
532 
533 	pr_debug("Releasing TCM Loop Core BUS\n");
534 }
535 
536 static char *tcm_loop_get_fabric_name(void)
537 {
538 	return "loopback";
539 }
540 
541 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
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 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
547 	 * time based on the protocol dependent prefix of the passed configfs group.
548 	 *
549 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
550 	 * ProtocolID using target_core_fabric_lib.c symbols.
551 	 */
552 	switch (tl_hba->tl_proto_id) {
553 	case SCSI_PROTOCOL_SAS:
554 		return sas_get_fabric_proto_ident(se_tpg);
555 	case SCSI_PROTOCOL_FCP:
556 		return fc_get_fabric_proto_ident(se_tpg);
557 	case SCSI_PROTOCOL_ISCSI:
558 		return iscsi_get_fabric_proto_ident(se_tpg);
559 	default:
560 		pr_err("Unknown tl_proto_id: 0x%02x, using"
561 			" SAS emulation\n", tl_hba->tl_proto_id);
562 		break;
563 	}
564 
565 	return sas_get_fabric_proto_ident(se_tpg);
566 }
567 
568 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
569 {
570 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
571 	/*
572 	 * Return the passed NAA identifier for the SAS Target Port
573 	 */
574 	return &tl_tpg->tl_hba->tl_wwn_address[0];
575 }
576 
577 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
578 {
579 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
580 	/*
581 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
582 	 * to represent the SCSI Target Port.
583 	 */
584 	return tl_tpg->tl_tpgt;
585 }
586 
587 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
588 {
589 	return 1;
590 }
591 
592 static u32 tcm_loop_get_pr_transport_id(
593 	struct se_portal_group *se_tpg,
594 	struct se_node_acl *se_nacl,
595 	struct t10_pr_registration *pr_reg,
596 	int *format_code,
597 	unsigned char *buf)
598 {
599 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
600 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
601 
602 	switch (tl_hba->tl_proto_id) {
603 	case SCSI_PROTOCOL_SAS:
604 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
605 					format_code, buf);
606 	case SCSI_PROTOCOL_FCP:
607 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
608 					format_code, buf);
609 	case SCSI_PROTOCOL_ISCSI:
610 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
611 					format_code, buf);
612 	default:
613 		pr_err("Unknown tl_proto_id: 0x%02x, using"
614 			" SAS emulation\n", tl_hba->tl_proto_id);
615 		break;
616 	}
617 
618 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
619 			format_code, buf);
620 }
621 
622 static u32 tcm_loop_get_pr_transport_id_len(
623 	struct se_portal_group *se_tpg,
624 	struct se_node_acl *se_nacl,
625 	struct t10_pr_registration *pr_reg,
626 	int *format_code)
627 {
628 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
629 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
630 
631 	switch (tl_hba->tl_proto_id) {
632 	case SCSI_PROTOCOL_SAS:
633 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
634 					format_code);
635 	case SCSI_PROTOCOL_FCP:
636 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
637 					format_code);
638 	case SCSI_PROTOCOL_ISCSI:
639 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
640 					format_code);
641 	default:
642 		pr_err("Unknown tl_proto_id: 0x%02x, using"
643 			" SAS emulation\n", tl_hba->tl_proto_id);
644 		break;
645 	}
646 
647 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
648 			format_code);
649 }
650 
651 /*
652  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
653  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
654  */
655 static char *tcm_loop_parse_pr_out_transport_id(
656 	struct se_portal_group *se_tpg,
657 	const char *buf,
658 	u32 *out_tid_len,
659 	char **port_nexus_ptr)
660 {
661 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
662 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
663 
664 	switch (tl_hba->tl_proto_id) {
665 	case SCSI_PROTOCOL_SAS:
666 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
667 					port_nexus_ptr);
668 	case SCSI_PROTOCOL_FCP:
669 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
670 					port_nexus_ptr);
671 	case SCSI_PROTOCOL_ISCSI:
672 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
673 					port_nexus_ptr);
674 	default:
675 		pr_err("Unknown tl_proto_id: 0x%02x, using"
676 			" SAS emulation\n", tl_hba->tl_proto_id);
677 		break;
678 	}
679 
680 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
681 			port_nexus_ptr);
682 }
683 
684 /*
685  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
686  * based upon the incoming fabric dependent SCSI Initiator Port
687  */
688 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
689 {
690 	return 1;
691 }
692 
693 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
694 {
695 	return 0;
696 }
697 
698 /*
699  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
700  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
701  */
702 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
703 {
704 	return 0;
705 }
706 
707 /*
708  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
709  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
710  * It has been added here as a nop for target_fabric_tf_ops_check()
711  */
712 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
713 {
714 	return 0;
715 }
716 
717 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
718 	struct se_portal_group *se_tpg)
719 {
720 	struct tcm_loop_nacl *tl_nacl;
721 
722 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
723 	if (!tl_nacl) {
724 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
725 		return NULL;
726 	}
727 
728 	return &tl_nacl->se_node_acl;
729 }
730 
731 static void tcm_loop_tpg_release_fabric_acl(
732 	struct se_portal_group *se_tpg,
733 	struct se_node_acl *se_nacl)
734 {
735 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
736 				struct tcm_loop_nacl, se_node_acl);
737 
738 	kfree(tl_nacl);
739 }
740 
741 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
742 {
743 	return 1;
744 }
745 
746 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
747 {
748 	return 1;
749 }
750 
751 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
752 {
753 	return;
754 }
755 
756 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
757 {
758 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
759 			struct tcm_loop_cmd, tl_se_cmd);
760 
761 	return tl_cmd->sc_cmd_tag;
762 }
763 
764 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
765 {
766 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
767 			struct tcm_loop_cmd, tl_se_cmd);
768 
769 	return tl_cmd->sc_cmd_state;
770 }
771 
772 static int tcm_loop_shutdown_session(struct se_session *se_sess)
773 {
774 	return 0;
775 }
776 
777 static void tcm_loop_close_session(struct se_session *se_sess)
778 {
779 	return;
780 };
781 
782 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
783 {
784 	/*
785 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
786 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
787 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
788 	 * format with transport_generic_map_mem_to_cmd().
789 	 *
790 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
791 	 * object execution queue.
792 	 */
793 	target_execute_cmd(se_cmd);
794 	return 0;
795 }
796 
797 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
798 {
799 	return 0;
800 }
801 
802 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
803 {
804 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
805 				struct tcm_loop_cmd, tl_se_cmd);
806 	struct scsi_cmnd *sc = tl_cmd->sc;
807 
808 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
809 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
810 
811 	sc->result = SAM_STAT_GOOD;
812 	set_host_byte(sc, DID_OK);
813 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
814 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
815 		scsi_set_resid(sc, se_cmd->residual_count);
816 	sc->scsi_done(sc);
817 	return 0;
818 }
819 
820 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
821 {
822 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
823 				struct tcm_loop_cmd, tl_se_cmd);
824 	struct scsi_cmnd *sc = tl_cmd->sc;
825 
826 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
827 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
828 
829 	if (se_cmd->sense_buffer &&
830 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
831 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
832 
833 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
834 				SCSI_SENSE_BUFFERSIZE);
835 		sc->result = SAM_STAT_CHECK_CONDITION;
836 		set_driver_byte(sc, DRIVER_SENSE);
837 	} else
838 		sc->result = se_cmd->scsi_status;
839 
840 	set_host_byte(sc, DID_OK);
841 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
842 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
843 		scsi_set_resid(sc, se_cmd->residual_count);
844 	sc->scsi_done(sc);
845 	return 0;
846 }
847 
848 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
849 {
850 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
851 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
852 	/*
853 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
854 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
855 	 */
856 	atomic_set(&tl_tmr->tmr_complete, 1);
857 	wake_up(&tl_tmr->tl_tmr_wait);
858 }
859 
860 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
861 {
862 	return;
863 }
864 
865 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
866 {
867 	switch (tl_hba->tl_proto_id) {
868 	case SCSI_PROTOCOL_SAS:
869 		return "SAS";
870 	case SCSI_PROTOCOL_FCP:
871 		return "FCP";
872 	case SCSI_PROTOCOL_ISCSI:
873 		return "iSCSI";
874 	default:
875 		break;
876 	}
877 
878 	return "Unknown";
879 }
880 
881 /* Start items for tcm_loop_port_cit */
882 
883 static int tcm_loop_port_link(
884 	struct se_portal_group *se_tpg,
885 	struct se_lun *lun)
886 {
887 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
888 				struct tcm_loop_tpg, tl_se_tpg);
889 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
890 
891 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
892 	/*
893 	 * Add Linux/SCSI struct scsi_device by HCTL
894 	 */
895 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
896 
897 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
898 	return 0;
899 }
900 
901 static void tcm_loop_port_unlink(
902 	struct se_portal_group *se_tpg,
903 	struct se_lun *se_lun)
904 {
905 	struct scsi_device *sd;
906 	struct tcm_loop_hba *tl_hba;
907 	struct tcm_loop_tpg *tl_tpg;
908 
909 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
910 	tl_hba = tl_tpg->tl_hba;
911 
912 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
913 				se_lun->unpacked_lun);
914 	if (!sd) {
915 		pr_err("Unable to locate struct scsi_device for %d:%d:"
916 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
917 		return;
918 	}
919 	/*
920 	 * Remove Linux/SCSI struct scsi_device by HCTL
921 	 */
922 	scsi_remove_device(sd);
923 	scsi_device_put(sd);
924 
925 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
926 
927 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
928 }
929 
930 /* End items for tcm_loop_port_cit */
931 
932 /* Start items for tcm_loop_nexus_cit */
933 
934 static int tcm_loop_make_nexus(
935 	struct tcm_loop_tpg *tl_tpg,
936 	const char *name)
937 {
938 	struct se_portal_group *se_tpg;
939 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
940 	struct tcm_loop_nexus *tl_nexus;
941 	int ret = -ENOMEM;
942 
943 	if (tl_tpg->tl_hba->tl_nexus) {
944 		pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
945 		return -EEXIST;
946 	}
947 	se_tpg = &tl_tpg->tl_se_tpg;
948 
949 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
950 	if (!tl_nexus) {
951 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
952 		return -ENOMEM;
953 	}
954 	/*
955 	 * Initialize the struct se_session pointer
956 	 */
957 	tl_nexus->se_sess = transport_init_session(TARGET_PROT_ALL);
958 	if (IS_ERR(tl_nexus->se_sess)) {
959 		ret = PTR_ERR(tl_nexus->se_sess);
960 		goto out;
961 	}
962 	/*
963 	 * Since we are running in 'demo mode' this call with generate a
964 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
965 	 * Initiator port name of the passed configfs group 'name'.
966 	 */
967 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
968 				se_tpg, (unsigned char *)name);
969 	if (!tl_nexus->se_sess->se_node_acl) {
970 		transport_free_session(tl_nexus->se_sess);
971 		goto out;
972 	}
973 	/*
974 	 * Now, register the SAS I_T Nexus as active with the call to
975 	 * transport_register_session()
976 	 */
977 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
978 			tl_nexus->se_sess, tl_nexus);
979 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
980 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
981 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
982 		name);
983 	return 0;
984 
985 out:
986 	kfree(tl_nexus);
987 	return ret;
988 }
989 
990 static int tcm_loop_drop_nexus(
991 	struct tcm_loop_tpg *tpg)
992 {
993 	struct se_session *se_sess;
994 	struct tcm_loop_nexus *tl_nexus;
995 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
996 
997 	if (!tl_hba)
998 		return -ENODEV;
999 
1000 	tl_nexus = tl_hba->tl_nexus;
1001 	if (!tl_nexus)
1002 		return -ENODEV;
1003 
1004 	se_sess = tl_nexus->se_sess;
1005 	if (!se_sess)
1006 		return -ENODEV;
1007 
1008 	if (atomic_read(&tpg->tl_tpg_port_count)) {
1009 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
1010 			" active TPG port count: %d\n",
1011 			atomic_read(&tpg->tl_tpg_port_count));
1012 		return -EPERM;
1013 	}
1014 
1015 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1016 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1017 		tl_nexus->se_sess->se_node_acl->initiatorname);
1018 	/*
1019 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
1020 	 */
1021 	transport_deregister_session(tl_nexus->se_sess);
1022 	tpg->tl_hba->tl_nexus = NULL;
1023 	kfree(tl_nexus);
1024 	return 0;
1025 }
1026 
1027 /* End items for tcm_loop_nexus_cit */
1028 
1029 static ssize_t tcm_loop_tpg_show_nexus(
1030 	struct se_portal_group *se_tpg,
1031 	char *page)
1032 {
1033 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1034 			struct tcm_loop_tpg, tl_se_tpg);
1035 	struct tcm_loop_nexus *tl_nexus;
1036 	ssize_t ret;
1037 
1038 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
1039 	if (!tl_nexus)
1040 		return -ENODEV;
1041 
1042 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1043 		tl_nexus->se_sess->se_node_acl->initiatorname);
1044 
1045 	return ret;
1046 }
1047 
1048 static ssize_t tcm_loop_tpg_store_nexus(
1049 	struct se_portal_group *se_tpg,
1050 	const char *page,
1051 	size_t count)
1052 {
1053 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1054 			struct tcm_loop_tpg, tl_se_tpg);
1055 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1056 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1057 	int ret;
1058 	/*
1059 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1060 	 */
1061 	if (!strncmp(page, "NULL", 4)) {
1062 		ret = tcm_loop_drop_nexus(tl_tpg);
1063 		return (!ret) ? count : ret;
1064 	}
1065 	/*
1066 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1067 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1068 	 * tcm_loop_make_nexus()
1069 	 */
1070 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1071 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1072 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1073 		return -EINVAL;
1074 	}
1075 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1076 
1077 	ptr = strstr(i_port, "naa.");
1078 	if (ptr) {
1079 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1080 			pr_err("Passed SAS Initiator Port %s does not"
1081 				" match target port protoid: %s\n", i_port,
1082 				tcm_loop_dump_proto_id(tl_hba));
1083 			return -EINVAL;
1084 		}
1085 		port_ptr = &i_port[0];
1086 		goto check_newline;
1087 	}
1088 	ptr = strstr(i_port, "fc.");
1089 	if (ptr) {
1090 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1091 			pr_err("Passed FCP Initiator Port %s does not"
1092 				" match target port protoid: %s\n", i_port,
1093 				tcm_loop_dump_proto_id(tl_hba));
1094 			return -EINVAL;
1095 		}
1096 		port_ptr = &i_port[3]; /* Skip over "fc." */
1097 		goto check_newline;
1098 	}
1099 	ptr = strstr(i_port, "iqn.");
1100 	if (ptr) {
1101 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1102 			pr_err("Passed iSCSI Initiator Port %s does not"
1103 				" match target port protoid: %s\n", i_port,
1104 				tcm_loop_dump_proto_id(tl_hba));
1105 			return -EINVAL;
1106 		}
1107 		port_ptr = &i_port[0];
1108 		goto check_newline;
1109 	}
1110 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1111 			" %s\n", i_port);
1112 	return -EINVAL;
1113 	/*
1114 	 * Clear any trailing newline for the NAA WWN
1115 	 */
1116 check_newline:
1117 	if (i_port[strlen(i_port)-1] == '\n')
1118 		i_port[strlen(i_port)-1] = '\0';
1119 
1120 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1121 	if (ret < 0)
1122 		return ret;
1123 
1124 	return count;
1125 }
1126 
1127 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1128 
1129 static ssize_t tcm_loop_tpg_show_transport_status(
1130 	struct se_portal_group *se_tpg,
1131 	char *page)
1132 {
1133 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1134 			struct tcm_loop_tpg, tl_se_tpg);
1135 	const char *status = NULL;
1136 	ssize_t ret = -EINVAL;
1137 
1138 	switch (tl_tpg->tl_transport_status) {
1139 	case TCM_TRANSPORT_ONLINE:
1140 		status = "online";
1141 		break;
1142 	case TCM_TRANSPORT_OFFLINE:
1143 		status = "offline";
1144 		break;
1145 	default:
1146 		break;
1147 	}
1148 
1149 	if (status)
1150 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1151 
1152 	return ret;
1153 }
1154 
1155 static ssize_t tcm_loop_tpg_store_transport_status(
1156 	struct se_portal_group *se_tpg,
1157 	const char *page,
1158 	size_t count)
1159 {
1160 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1161 			struct tcm_loop_tpg, tl_se_tpg);
1162 
1163 	if (!strncmp(page, "online", 6)) {
1164 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1165 		return count;
1166 	}
1167 	if (!strncmp(page, "offline", 7)) {
1168 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1169 		return count;
1170 	}
1171 	return -EINVAL;
1172 }
1173 
1174 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1175 
1176 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1177 	&tcm_loop_tpg_nexus.attr,
1178 	&tcm_loop_tpg_transport_status.attr,
1179 	NULL,
1180 };
1181 
1182 /* Start items for tcm_loop_naa_cit */
1183 
1184 static struct se_portal_group *tcm_loop_make_naa_tpg(
1185 	struct se_wwn *wwn,
1186 	struct config_group *group,
1187 	const char *name)
1188 {
1189 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1190 			struct tcm_loop_hba, tl_hba_wwn);
1191 	struct tcm_loop_tpg *tl_tpg;
1192 	char *tpgt_str, *end_ptr;
1193 	int ret;
1194 	unsigned short int tpgt;
1195 
1196 	tpgt_str = strstr(name, "tpgt_");
1197 	if (!tpgt_str) {
1198 		pr_err("Unable to locate \"tpgt_#\" directory"
1199 				" group\n");
1200 		return ERR_PTR(-EINVAL);
1201 	}
1202 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1203 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1204 
1205 	if (tpgt >= TL_TPGS_PER_HBA) {
1206 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1207 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1208 		return ERR_PTR(-EINVAL);
1209 	}
1210 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1211 	tl_tpg->tl_hba = tl_hba;
1212 	tl_tpg->tl_tpgt = tpgt;
1213 	/*
1214 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1215 	 */
1216 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1217 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1218 			TRANSPORT_TPG_TYPE_NORMAL);
1219 	if (ret < 0)
1220 		return ERR_PTR(-ENOMEM);
1221 
1222 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1223 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1224 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1225 
1226 	return &tl_tpg->tl_se_tpg;
1227 }
1228 
1229 static void tcm_loop_drop_naa_tpg(
1230 	struct se_portal_group *se_tpg)
1231 {
1232 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1233 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1234 				struct tcm_loop_tpg, tl_se_tpg);
1235 	struct tcm_loop_hba *tl_hba;
1236 	unsigned short tpgt;
1237 
1238 	tl_hba = tl_tpg->tl_hba;
1239 	tpgt = tl_tpg->tl_tpgt;
1240 	/*
1241 	 * Release the I_T Nexus for the Virtual SAS link if present
1242 	 */
1243 	tcm_loop_drop_nexus(tl_tpg);
1244 	/*
1245 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1246 	 */
1247 	core_tpg_deregister(se_tpg);
1248 
1249 	tl_tpg->tl_hba = NULL;
1250 	tl_tpg->tl_tpgt = 0;
1251 
1252 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1253 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1254 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1255 }
1256 
1257 /* End items for tcm_loop_naa_cit */
1258 
1259 /* Start items for tcm_loop_cit */
1260 
1261 static struct se_wwn *tcm_loop_make_scsi_hba(
1262 	struct target_fabric_configfs *tf,
1263 	struct config_group *group,
1264 	const char *name)
1265 {
1266 	struct tcm_loop_hba *tl_hba;
1267 	struct Scsi_Host *sh;
1268 	char *ptr;
1269 	int ret, off = 0;
1270 
1271 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1272 	if (!tl_hba) {
1273 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1274 		return ERR_PTR(-ENOMEM);
1275 	}
1276 	/*
1277 	 * Determine the emulated Protocol Identifier and Target Port Name
1278 	 * based on the incoming configfs directory name.
1279 	 */
1280 	ptr = strstr(name, "naa.");
1281 	if (ptr) {
1282 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1283 		goto check_len;
1284 	}
1285 	ptr = strstr(name, "fc.");
1286 	if (ptr) {
1287 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1288 		off = 3; /* Skip over "fc." */
1289 		goto check_len;
1290 	}
1291 	ptr = strstr(name, "iqn.");
1292 	if (!ptr) {
1293 		pr_err("Unable to locate prefix for emulated Target "
1294 				"Port: %s\n", name);
1295 		ret = -EINVAL;
1296 		goto out;
1297 	}
1298 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1299 
1300 check_len:
1301 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1302 		pr_err("Emulated NAA %s Address: %s, exceeds"
1303 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1304 			TL_WWN_ADDR_LEN);
1305 		ret = -EINVAL;
1306 		goto out;
1307 	}
1308 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1309 
1310 	/*
1311 	 * Call device_register(tl_hba->dev) to register the emulated
1312 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1313 	 * device_register() callbacks in tcm_loop_driver_probe()
1314 	 */
1315 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1316 	if (ret)
1317 		goto out;
1318 
1319 	sh = tl_hba->sh;
1320 	tcm_loop_hba_no_cnt++;
1321 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1322 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1323 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1324 
1325 	return &tl_hba->tl_hba_wwn;
1326 out:
1327 	kfree(tl_hba);
1328 	return ERR_PTR(ret);
1329 }
1330 
1331 static void tcm_loop_drop_scsi_hba(
1332 	struct se_wwn *wwn)
1333 {
1334 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1335 				struct tcm_loop_hba, tl_hba_wwn);
1336 
1337 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1338 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1339 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1340 	/*
1341 	 * Call device_unregister() on the original tl_hba->dev.
1342 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1343 	 * release *tl_hba;
1344 	 */
1345 	device_unregister(&tl_hba->dev);
1346 }
1347 
1348 /* Start items for tcm_loop_cit */
1349 static ssize_t tcm_loop_wwn_show_attr_version(
1350 	struct target_fabric_configfs *tf,
1351 	char *page)
1352 {
1353 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1354 }
1355 
1356 TF_WWN_ATTR_RO(tcm_loop, version);
1357 
1358 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1359 	&tcm_loop_wwn_version.attr,
1360 	NULL,
1361 };
1362 
1363 /* End items for tcm_loop_cit */
1364 
1365 static int tcm_loop_register_configfs(void)
1366 {
1367 	struct target_fabric_configfs *fabric;
1368 	int ret;
1369 	/*
1370 	 * Set the TCM Loop HBA counter to zero
1371 	 */
1372 	tcm_loop_hba_no_cnt = 0;
1373 	/*
1374 	 * Register the top level struct config_item_type with TCM core
1375 	 */
1376 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1377 	if (IS_ERR(fabric)) {
1378 		pr_err("tcm_loop_register_configfs() failed!\n");
1379 		return PTR_ERR(fabric);
1380 	}
1381 	/*
1382 	 * Setup the fabric API of function pointers used by target_core_mod
1383 	 */
1384 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1385 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1386 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1387 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1388 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1389 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1390 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1391 					&tcm_loop_get_pr_transport_id_len;
1392 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1393 					&tcm_loop_parse_pr_out_transport_id;
1394 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1395 	fabric->tf_ops.tpg_check_demo_mode_cache =
1396 					&tcm_loop_check_demo_mode_cache;
1397 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1398 					&tcm_loop_check_demo_mode_write_protect;
1399 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1400 					&tcm_loop_check_prod_mode_write_protect;
1401 	/*
1402 	 * The TCM loopback fabric module runs in demo-mode to a local
1403 	 * virtual SCSI device, so fabric dependent initator ACLs are
1404 	 * not required.
1405 	 */
1406 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1407 	fabric->tf_ops.tpg_release_fabric_acl =
1408 					&tcm_loop_tpg_release_fabric_acl;
1409 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1410 	/*
1411 	 * Used for setting up remaining TCM resources in process context
1412 	 */
1413 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1414 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1415 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1416 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1417 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1418 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1419 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1420 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1421 	/*
1422 	 * Not used for TCM loopback
1423 	 */
1424 	fabric->tf_ops.set_default_node_attributes =
1425 					&tcm_loop_set_default_node_attributes;
1426 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1427 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1428 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1429 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1430 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1431 	fabric->tf_ops.aborted_task = &tcm_loop_aborted_task;
1432 
1433 	/*
1434 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1435 	 */
1436 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1437 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1438 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1439 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1440 	/*
1441 	 * fabric_post_link() and fabric_pre_unlink() are used for
1442 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1443 	 */
1444 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1445 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1446 	fabric->tf_ops.fabric_make_np = NULL;
1447 	fabric->tf_ops.fabric_drop_np = NULL;
1448 	/*
1449 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1450 	 */
1451 	fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1452 	fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1453 	fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1454 	fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1455 	fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1456 	/*
1457 	 * Once fabric->tf_ops has been setup, now register the fabric for
1458 	 * use within TCM
1459 	 */
1460 	ret = target_fabric_configfs_register(fabric);
1461 	if (ret < 0) {
1462 		pr_err("target_fabric_configfs_register() for"
1463 				" TCM_Loop failed!\n");
1464 		target_fabric_configfs_free(fabric);
1465 		return -1;
1466 	}
1467 	/*
1468 	 * Setup our local pointer to *fabric.
1469 	 */
1470 	tcm_loop_fabric_configfs = fabric;
1471 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1472 			" tcm_loop_fabric_configfs\n");
1473 	return 0;
1474 }
1475 
1476 static void tcm_loop_deregister_configfs(void)
1477 {
1478 	if (!tcm_loop_fabric_configfs)
1479 		return;
1480 
1481 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1482 	tcm_loop_fabric_configfs = NULL;
1483 	pr_debug("TCM_LOOP[0] - Cleared"
1484 				" tcm_loop_fabric_configfs\n");
1485 }
1486 
1487 static int __init tcm_loop_fabric_init(void)
1488 {
1489 	int ret = -ENOMEM;
1490 
1491 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1492 	if (!tcm_loop_workqueue)
1493 		goto out;
1494 
1495 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1496 				sizeof(struct tcm_loop_cmd),
1497 				__alignof__(struct tcm_loop_cmd),
1498 				0, NULL);
1499 	if (!tcm_loop_cmd_cache) {
1500 		pr_debug("kmem_cache_create() for"
1501 			" tcm_loop_cmd_cache failed\n");
1502 		goto out_destroy_workqueue;
1503 	}
1504 
1505 	ret = tcm_loop_alloc_core_bus();
1506 	if (ret)
1507 		goto out_destroy_cache;
1508 
1509 	ret = tcm_loop_register_configfs();
1510 	if (ret)
1511 		goto out_release_core_bus;
1512 
1513 	return 0;
1514 
1515 out_release_core_bus:
1516 	tcm_loop_release_core_bus();
1517 out_destroy_cache:
1518 	kmem_cache_destroy(tcm_loop_cmd_cache);
1519 out_destroy_workqueue:
1520 	destroy_workqueue(tcm_loop_workqueue);
1521 out:
1522 	return ret;
1523 }
1524 
1525 static void __exit tcm_loop_fabric_exit(void)
1526 {
1527 	tcm_loop_deregister_configfs();
1528 	tcm_loop_release_core_bus();
1529 	kmem_cache_destroy(tcm_loop_cmd_cache);
1530 	destroy_workqueue(tcm_loop_workqueue);
1531 }
1532 
1533 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1534 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1535 MODULE_LICENSE("GPL");
1536 module_init(tcm_loop_fabric_init);
1537 module_exit(tcm_loop_fabric_exit);
1538