1 /*******************************************************************************
2  *
3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
4  * for emulated SAS initiator ports
5  *
6  * © Copyright 2011 RisingTide Systems LLC.
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_proc_info(struct Scsi_Host *host, char *buffer,
83 				char **start, off_t offset,
84 				int length, int inout)
85 {
86 	return sprintf(buffer, "tcm_loop_proc_info()\n");
87 }
88 
89 static int tcm_loop_driver_probe(struct device *);
90 static int tcm_loop_driver_remove(struct device *);
91 
92 static int pseudo_lld_bus_match(struct device *dev,
93 				struct device_driver *dev_driver)
94 {
95 	return 1;
96 }
97 
98 static struct bus_type tcm_loop_lld_bus = {
99 	.name			= "tcm_loop_bus",
100 	.match			= pseudo_lld_bus_match,
101 	.probe			= tcm_loop_driver_probe,
102 	.remove			= tcm_loop_driver_remove,
103 };
104 
105 static struct device_driver tcm_loop_driverfs = {
106 	.name			= "tcm_loop",
107 	.bus			= &tcm_loop_lld_bus,
108 };
109 /*
110  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
111  */
112 struct device *tcm_loop_primary;
113 
114 /*
115  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
116  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
117  */
118 static int tcm_loop_change_queue_depth(
119 	struct scsi_device *sdev,
120 	int depth,
121 	int reason)
122 {
123 	switch (reason) {
124 	case SCSI_QDEPTH_DEFAULT:
125 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
126 		break;
127 	case SCSI_QDEPTH_QFULL:
128 		scsi_track_queue_full(sdev, depth);
129 		break;
130 	case SCSI_QDEPTH_RAMP_UP:
131 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
132 		break;
133 	default:
134 		return -EOPNOTSUPP;
135 	}
136 	return sdev->queue_depth;
137 }
138 
139 /*
140  * Locate the SAM Task Attr from struct scsi_cmnd *
141  */
142 static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
143 {
144 	if (sc->device->tagged_supported) {
145 		switch (sc->tag) {
146 		case HEAD_OF_QUEUE_TAG:
147 			return MSG_HEAD_TAG;
148 		case ORDERED_QUEUE_TAG:
149 			return MSG_ORDERED_TAG;
150 		default:
151 			break;
152 		}
153 	}
154 
155 	return MSG_SIMPLE_TAG;
156 }
157 
158 static void tcm_loop_submission_work(struct work_struct *work)
159 {
160 	struct tcm_loop_cmd *tl_cmd =
161 		container_of(work, struct tcm_loop_cmd, work);
162 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
163 	struct scsi_cmnd *sc = tl_cmd->sc;
164 	struct tcm_loop_nexus *tl_nexus;
165 	struct tcm_loop_hba *tl_hba;
166 	struct tcm_loop_tpg *tl_tpg;
167 	struct scatterlist *sgl_bidi = NULL;
168 	u32 sgl_bidi_count = 0;
169 	int rc;
170 
171 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
172 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
173 
174 	/*
175 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
176 	 * has already been configured via tcm_loop_make_naa_tpg().
177 	 */
178 	if (!tl_tpg->tl_hba) {
179 		set_host_byte(sc, DID_NO_CONNECT);
180 		goto out_done;
181 	}
182 
183 	tl_nexus = tl_hba->tl_nexus;
184 	if (!tl_nexus) {
185 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
186 				" does not exist\n");
187 		set_host_byte(sc, DID_ERROR);
188 		goto out_done;
189 	}
190 	if (scsi_bidi_cmnd(sc)) {
191 		struct scsi_data_buffer *sdb = scsi_in(sc);
192 
193 		sgl_bidi = sdb->table.sgl;
194 		sgl_bidi_count = sdb->table.nents;
195 		se_cmd->se_cmd_flags |= SCF_BIDI;
196 
197 	}
198 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
199 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
200 			scsi_bufflen(sc), tcm_loop_sam_attr(sc),
201 			sc->sc_data_direction, 0,
202 			scsi_sglist(sc), scsi_sg_count(sc),
203 			sgl_bidi, sgl_bidi_count);
204 	if (rc < 0) {
205 		set_host_byte(sc, DID_NO_CONNECT);
206 		goto out_done;
207 	}
208 	return;
209 
210 out_done:
211 	sc->scsi_done(sc);
212 	return;
213 }
214 
215 /*
216  * ->queuecommand can be and usually is called from interrupt context, so
217  * defer the actual submission to a workqueue.
218  */
219 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
220 {
221 	struct tcm_loop_cmd *tl_cmd;
222 
223 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
224 		" scsi_buf_len: %u\n", sc->device->host->host_no,
225 		sc->device->id, sc->device->channel, sc->device->lun,
226 		sc->cmnd[0], scsi_bufflen(sc));
227 
228 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
229 	if (!tl_cmd) {
230 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
231 		set_host_byte(sc, DID_ERROR);
232 		sc->scsi_done(sc);
233 		return 0;
234 	}
235 
236 	tl_cmd->sc = sc;
237 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
238 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
239 	return 0;
240 }
241 
242 /*
243  * Called from SCSI EH process context to issue a LUN_RESET TMR
244  * to struct scsi_device
245  */
246 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
247 {
248 	struct se_cmd *se_cmd = NULL;
249 	struct se_portal_group *se_tpg;
250 	struct se_session *se_sess;
251 	struct tcm_loop_cmd *tl_cmd = NULL;
252 	struct tcm_loop_hba *tl_hba;
253 	struct tcm_loop_nexus *tl_nexus;
254 	struct tcm_loop_tmr *tl_tmr = NULL;
255 	struct tcm_loop_tpg *tl_tpg;
256 	int ret = FAILED, rc;
257 	/*
258 	 * Locate the tcm_loop_hba_t pointer
259 	 */
260 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
261 	/*
262 	 * Locate the tl_nexus and se_sess pointers
263 	 */
264 	tl_nexus = tl_hba->tl_nexus;
265 	if (!tl_nexus) {
266 		pr_err("Unable to perform device reset without"
267 				" active I_T Nexus\n");
268 		return FAILED;
269 	}
270 	se_sess = tl_nexus->se_sess;
271 	/*
272 	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
273 	 */
274 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
275 	se_tpg = &tl_tpg->tl_se_tpg;
276 
277 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
278 	if (!tl_cmd) {
279 		pr_err("Unable to allocate memory for tl_cmd\n");
280 		return FAILED;
281 	}
282 
283 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
284 	if (!tl_tmr) {
285 		pr_err("Unable to allocate memory for tl_tmr\n");
286 		goto release;
287 	}
288 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
289 
290 	se_cmd = &tl_cmd->tl_se_cmd;
291 	/*
292 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
293 	 */
294 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
295 				DMA_NONE, MSG_SIMPLE_TAG,
296 				&tl_cmd->tl_sense_buf[0]);
297 
298 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
299 	if (rc < 0)
300 		goto release;
301 	/*
302 	 * Locate the underlying TCM struct se_lun from sc->device->lun
303 	 */
304 	if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
305 		goto release;
306 	/*
307 	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
308 	 * to wake us up.
309 	 */
310 	transport_generic_handle_tmr(se_cmd);
311 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
312 	/*
313 	 * The TMR LUN_RESET has completed, check the response status and
314 	 * then release allocations.
315 	 */
316 	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
317 		SUCCESS : FAILED;
318 release:
319 	if (se_cmd)
320 		transport_generic_free_cmd(se_cmd, 1);
321 	else
322 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
323 	kfree(tl_tmr);
324 	return ret;
325 }
326 
327 static int tcm_loop_slave_alloc(struct scsi_device *sd)
328 {
329 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
330 	return 0;
331 }
332 
333 static int tcm_loop_slave_configure(struct scsi_device *sd)
334 {
335 	return 0;
336 }
337 
338 static struct scsi_host_template tcm_loop_driver_template = {
339 	.proc_info		= tcm_loop_proc_info,
340 	.proc_name		= "tcm_loopback",
341 	.name			= "TCM_Loopback",
342 	.queuecommand		= tcm_loop_queuecommand,
343 	.change_queue_depth	= tcm_loop_change_queue_depth,
344 	.eh_device_reset_handler = tcm_loop_device_reset,
345 	.can_queue		= 1024,
346 	.this_id		= -1,
347 	.sg_tablesize		= 256,
348 	.cmd_per_lun		= 1024,
349 	.max_sectors		= 0xFFFF,
350 	.use_clustering		= DISABLE_CLUSTERING,
351 	.slave_alloc		= tcm_loop_slave_alloc,
352 	.slave_configure	= tcm_loop_slave_configure,
353 	.module			= THIS_MODULE,
354 };
355 
356 static int tcm_loop_driver_probe(struct device *dev)
357 {
358 	struct tcm_loop_hba *tl_hba;
359 	struct Scsi_Host *sh;
360 	int error;
361 
362 	tl_hba = to_tcm_loop_hba(dev);
363 
364 	sh = scsi_host_alloc(&tcm_loop_driver_template,
365 			sizeof(struct tcm_loop_hba));
366 	if (!sh) {
367 		pr_err("Unable to allocate struct scsi_host\n");
368 		return -ENODEV;
369 	}
370 	tl_hba->sh = sh;
371 
372 	/*
373 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
374 	 */
375 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
376 	/*
377 	 * Setup single ID, Channel and LUN for now..
378 	 */
379 	sh->max_id = 2;
380 	sh->max_lun = 0;
381 	sh->max_channel = 0;
382 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
383 
384 	error = scsi_add_host(sh, &tl_hba->dev);
385 	if (error) {
386 		pr_err("%s: scsi_add_host failed\n", __func__);
387 		scsi_host_put(sh);
388 		return -ENODEV;
389 	}
390 	return 0;
391 }
392 
393 static int tcm_loop_driver_remove(struct device *dev)
394 {
395 	struct tcm_loop_hba *tl_hba;
396 	struct Scsi_Host *sh;
397 
398 	tl_hba = to_tcm_loop_hba(dev);
399 	sh = tl_hba->sh;
400 
401 	scsi_remove_host(sh);
402 	scsi_host_put(sh);
403 	return 0;
404 }
405 
406 static void tcm_loop_release_adapter(struct device *dev)
407 {
408 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
409 
410 	kfree(tl_hba);
411 }
412 
413 /*
414  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
415  */
416 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
417 {
418 	int ret;
419 
420 	tl_hba->dev.bus = &tcm_loop_lld_bus;
421 	tl_hba->dev.parent = tcm_loop_primary;
422 	tl_hba->dev.release = &tcm_loop_release_adapter;
423 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
424 
425 	ret = device_register(&tl_hba->dev);
426 	if (ret) {
427 		pr_err("device_register() failed for"
428 				" tl_hba->dev: %d\n", ret);
429 		return -ENODEV;
430 	}
431 
432 	return 0;
433 }
434 
435 /*
436  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
437  * tcm_loop SCSI bus.
438  */
439 static int tcm_loop_alloc_core_bus(void)
440 {
441 	int ret;
442 
443 	tcm_loop_primary = root_device_register("tcm_loop_0");
444 	if (IS_ERR(tcm_loop_primary)) {
445 		pr_err("Unable to allocate tcm_loop_primary\n");
446 		return PTR_ERR(tcm_loop_primary);
447 	}
448 
449 	ret = bus_register(&tcm_loop_lld_bus);
450 	if (ret) {
451 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
452 		goto dev_unreg;
453 	}
454 
455 	ret = driver_register(&tcm_loop_driverfs);
456 	if (ret) {
457 		pr_err("driver_register() failed for"
458 				"tcm_loop_driverfs\n");
459 		goto bus_unreg;
460 	}
461 
462 	pr_debug("Initialized TCM Loop Core Bus\n");
463 	return ret;
464 
465 bus_unreg:
466 	bus_unregister(&tcm_loop_lld_bus);
467 dev_unreg:
468 	root_device_unregister(tcm_loop_primary);
469 	return ret;
470 }
471 
472 static void tcm_loop_release_core_bus(void)
473 {
474 	driver_unregister(&tcm_loop_driverfs);
475 	bus_unregister(&tcm_loop_lld_bus);
476 	root_device_unregister(tcm_loop_primary);
477 
478 	pr_debug("Releasing TCM Loop Core BUS\n");
479 }
480 
481 static char *tcm_loop_get_fabric_name(void)
482 {
483 	return "loopback";
484 }
485 
486 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
487 {
488 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
489 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
490 	/*
491 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
492 	 * time based on the protocol dependent prefix of the passed configfs group.
493 	 *
494 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
495 	 * ProtocolID using target_core_fabric_lib.c symbols.
496 	 */
497 	switch (tl_hba->tl_proto_id) {
498 	case SCSI_PROTOCOL_SAS:
499 		return sas_get_fabric_proto_ident(se_tpg);
500 	case SCSI_PROTOCOL_FCP:
501 		return fc_get_fabric_proto_ident(se_tpg);
502 	case SCSI_PROTOCOL_ISCSI:
503 		return iscsi_get_fabric_proto_ident(se_tpg);
504 	default:
505 		pr_err("Unknown tl_proto_id: 0x%02x, using"
506 			" SAS emulation\n", tl_hba->tl_proto_id);
507 		break;
508 	}
509 
510 	return sas_get_fabric_proto_ident(se_tpg);
511 }
512 
513 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
514 {
515 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
516 	/*
517 	 * Return the passed NAA identifier for the SAS Target Port
518 	 */
519 	return &tl_tpg->tl_hba->tl_wwn_address[0];
520 }
521 
522 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
523 {
524 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
525 	/*
526 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
527 	 * to represent the SCSI Target Port.
528 	 */
529 	return tl_tpg->tl_tpgt;
530 }
531 
532 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
533 {
534 	return 1;
535 }
536 
537 static u32 tcm_loop_get_pr_transport_id(
538 	struct se_portal_group *se_tpg,
539 	struct se_node_acl *se_nacl,
540 	struct t10_pr_registration *pr_reg,
541 	int *format_code,
542 	unsigned char *buf)
543 {
544 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
545 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
546 
547 	switch (tl_hba->tl_proto_id) {
548 	case SCSI_PROTOCOL_SAS:
549 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
550 					format_code, buf);
551 	case SCSI_PROTOCOL_FCP:
552 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
553 					format_code, buf);
554 	case SCSI_PROTOCOL_ISCSI:
555 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
556 					format_code, buf);
557 	default:
558 		pr_err("Unknown tl_proto_id: 0x%02x, using"
559 			" SAS emulation\n", tl_hba->tl_proto_id);
560 		break;
561 	}
562 
563 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
564 			format_code, buf);
565 }
566 
567 static u32 tcm_loop_get_pr_transport_id_len(
568 	struct se_portal_group *se_tpg,
569 	struct se_node_acl *se_nacl,
570 	struct t10_pr_registration *pr_reg,
571 	int *format_code)
572 {
573 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
574 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
575 
576 	switch (tl_hba->tl_proto_id) {
577 	case SCSI_PROTOCOL_SAS:
578 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
579 					format_code);
580 	case SCSI_PROTOCOL_FCP:
581 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
582 					format_code);
583 	case SCSI_PROTOCOL_ISCSI:
584 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
585 					format_code);
586 	default:
587 		pr_err("Unknown tl_proto_id: 0x%02x, using"
588 			" SAS emulation\n", tl_hba->tl_proto_id);
589 		break;
590 	}
591 
592 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
593 			format_code);
594 }
595 
596 /*
597  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
598  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
599  */
600 static char *tcm_loop_parse_pr_out_transport_id(
601 	struct se_portal_group *se_tpg,
602 	const char *buf,
603 	u32 *out_tid_len,
604 	char **port_nexus_ptr)
605 {
606 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
607 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
608 
609 	switch (tl_hba->tl_proto_id) {
610 	case SCSI_PROTOCOL_SAS:
611 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
612 					port_nexus_ptr);
613 	case SCSI_PROTOCOL_FCP:
614 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
615 					port_nexus_ptr);
616 	case SCSI_PROTOCOL_ISCSI:
617 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
618 					port_nexus_ptr);
619 	default:
620 		pr_err("Unknown tl_proto_id: 0x%02x, using"
621 			" SAS emulation\n", tl_hba->tl_proto_id);
622 		break;
623 	}
624 
625 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
626 			port_nexus_ptr);
627 }
628 
629 /*
630  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
631  * based upon the incoming fabric dependent SCSI Initiator Port
632  */
633 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
634 {
635 	return 1;
636 }
637 
638 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
639 {
640 	return 0;
641 }
642 
643 /*
644  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
645  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
646  */
647 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
648 {
649 	return 0;
650 }
651 
652 /*
653  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
654  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
655  * It has been added here as a nop for target_fabric_tf_ops_check()
656  */
657 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
658 {
659 	return 0;
660 }
661 
662 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
663 	struct se_portal_group *se_tpg)
664 {
665 	struct tcm_loop_nacl *tl_nacl;
666 
667 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
668 	if (!tl_nacl) {
669 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
670 		return NULL;
671 	}
672 
673 	return &tl_nacl->se_node_acl;
674 }
675 
676 static void tcm_loop_tpg_release_fabric_acl(
677 	struct se_portal_group *se_tpg,
678 	struct se_node_acl *se_nacl)
679 {
680 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
681 				struct tcm_loop_nacl, se_node_acl);
682 
683 	kfree(tl_nacl);
684 }
685 
686 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
687 {
688 	return 1;
689 }
690 
691 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
692 {
693 	return 1;
694 }
695 
696 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
697 {
698 	return;
699 }
700 
701 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
702 {
703 	return 1;
704 }
705 
706 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
707 {
708 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
709 			struct tcm_loop_cmd, tl_se_cmd);
710 
711 	return tl_cmd->sc_cmd_state;
712 }
713 
714 static int tcm_loop_shutdown_session(struct se_session *se_sess)
715 {
716 	return 0;
717 }
718 
719 static void tcm_loop_close_session(struct se_session *se_sess)
720 {
721 	return;
722 };
723 
724 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
725 {
726 	/*
727 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
728 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
729 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
730 	 * format with transport_generic_map_mem_to_cmd().
731 	 *
732 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
733 	 * object execution queue.
734 	 */
735 	target_execute_cmd(se_cmd);
736 	return 0;
737 }
738 
739 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
740 {
741 	return 0;
742 }
743 
744 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
745 {
746 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
747 				struct tcm_loop_cmd, tl_se_cmd);
748 	struct scsi_cmnd *sc = tl_cmd->sc;
749 
750 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
751 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
752 
753 	sc->result = SAM_STAT_GOOD;
754 	set_host_byte(sc, DID_OK);
755 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
756 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
757 		scsi_set_resid(sc, se_cmd->residual_count);
758 	sc->scsi_done(sc);
759 	return 0;
760 }
761 
762 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
763 {
764 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
765 				struct tcm_loop_cmd, tl_se_cmd);
766 	struct scsi_cmnd *sc = tl_cmd->sc;
767 
768 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
769 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
770 
771 	if (se_cmd->sense_buffer &&
772 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
773 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
774 
775 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
776 				SCSI_SENSE_BUFFERSIZE);
777 		sc->result = SAM_STAT_CHECK_CONDITION;
778 		set_driver_byte(sc, DRIVER_SENSE);
779 	} else
780 		sc->result = se_cmd->scsi_status;
781 
782 	set_host_byte(sc, DID_OK);
783 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
784 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
785 		scsi_set_resid(sc, se_cmd->residual_count);
786 	sc->scsi_done(sc);
787 	return 0;
788 }
789 
790 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
791 {
792 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
793 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
794 	/*
795 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
796 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
797 	 */
798 	atomic_set(&tl_tmr->tmr_complete, 1);
799 	wake_up(&tl_tmr->tl_tmr_wait);
800 	return 0;
801 }
802 
803 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
804 {
805 	switch (tl_hba->tl_proto_id) {
806 	case SCSI_PROTOCOL_SAS:
807 		return "SAS";
808 	case SCSI_PROTOCOL_FCP:
809 		return "FCP";
810 	case SCSI_PROTOCOL_ISCSI:
811 		return "iSCSI";
812 	default:
813 		break;
814 	}
815 
816 	return "Unknown";
817 }
818 
819 /* Start items for tcm_loop_port_cit */
820 
821 static int tcm_loop_port_link(
822 	struct se_portal_group *se_tpg,
823 	struct se_lun *lun)
824 {
825 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
826 				struct tcm_loop_tpg, tl_se_tpg);
827 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
828 
829 	atomic_inc(&tl_tpg->tl_tpg_port_count);
830 	smp_mb__after_atomic_inc();
831 	/*
832 	 * Add Linux/SCSI struct scsi_device by HCTL
833 	 */
834 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
835 
836 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
837 	return 0;
838 }
839 
840 static void tcm_loop_port_unlink(
841 	struct se_portal_group *se_tpg,
842 	struct se_lun *se_lun)
843 {
844 	struct scsi_device *sd;
845 	struct tcm_loop_hba *tl_hba;
846 	struct tcm_loop_tpg *tl_tpg;
847 
848 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
849 	tl_hba = tl_tpg->tl_hba;
850 
851 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
852 				se_lun->unpacked_lun);
853 	if (!sd) {
854 		pr_err("Unable to locate struct scsi_device for %d:%d:"
855 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
856 		return;
857 	}
858 	/*
859 	 * Remove Linux/SCSI struct scsi_device by HCTL
860 	 */
861 	scsi_remove_device(sd);
862 	scsi_device_put(sd);
863 
864 	atomic_dec(&tl_tpg->tl_tpg_port_count);
865 	smp_mb__after_atomic_dec();
866 
867 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
868 }
869 
870 /* End items for tcm_loop_port_cit */
871 
872 /* Start items for tcm_loop_nexus_cit */
873 
874 static int tcm_loop_make_nexus(
875 	struct tcm_loop_tpg *tl_tpg,
876 	const char *name)
877 {
878 	struct se_portal_group *se_tpg;
879 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
880 	struct tcm_loop_nexus *tl_nexus;
881 	int ret = -ENOMEM;
882 
883 	if (tl_tpg->tl_hba->tl_nexus) {
884 		pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
885 		return -EEXIST;
886 	}
887 	se_tpg = &tl_tpg->tl_se_tpg;
888 
889 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
890 	if (!tl_nexus) {
891 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
892 		return -ENOMEM;
893 	}
894 	/*
895 	 * Initialize the struct se_session pointer
896 	 */
897 	tl_nexus->se_sess = transport_init_session();
898 	if (IS_ERR(tl_nexus->se_sess)) {
899 		ret = PTR_ERR(tl_nexus->se_sess);
900 		goto out;
901 	}
902 	/*
903 	 * Since we are running in 'demo mode' this call with generate a
904 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
905 	 * Initiator port name of the passed configfs group 'name'.
906 	 */
907 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
908 				se_tpg, (unsigned char *)name);
909 	if (!tl_nexus->se_sess->se_node_acl) {
910 		transport_free_session(tl_nexus->se_sess);
911 		goto out;
912 	}
913 	/*
914 	 * Now, register the SAS I_T Nexus as active with the call to
915 	 * transport_register_session()
916 	 */
917 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
918 			tl_nexus->se_sess, tl_nexus);
919 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
920 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
921 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
922 		name);
923 	return 0;
924 
925 out:
926 	kfree(tl_nexus);
927 	return ret;
928 }
929 
930 static int tcm_loop_drop_nexus(
931 	struct tcm_loop_tpg *tpg)
932 {
933 	struct se_session *se_sess;
934 	struct tcm_loop_nexus *tl_nexus;
935 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
936 
937 	tl_nexus = tpg->tl_hba->tl_nexus;
938 	if (!tl_nexus)
939 		return -ENODEV;
940 
941 	se_sess = tl_nexus->se_sess;
942 	if (!se_sess)
943 		return -ENODEV;
944 
945 	if (atomic_read(&tpg->tl_tpg_port_count)) {
946 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
947 			" active TPG port count: %d\n",
948 			atomic_read(&tpg->tl_tpg_port_count));
949 		return -EPERM;
950 	}
951 
952 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
953 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
954 		tl_nexus->se_sess->se_node_acl->initiatorname);
955 	/*
956 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
957 	 */
958 	transport_deregister_session(tl_nexus->se_sess);
959 	tpg->tl_hba->tl_nexus = NULL;
960 	kfree(tl_nexus);
961 	return 0;
962 }
963 
964 /* End items for tcm_loop_nexus_cit */
965 
966 static ssize_t tcm_loop_tpg_show_nexus(
967 	struct se_portal_group *se_tpg,
968 	char *page)
969 {
970 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
971 			struct tcm_loop_tpg, tl_se_tpg);
972 	struct tcm_loop_nexus *tl_nexus;
973 	ssize_t ret;
974 
975 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
976 	if (!tl_nexus)
977 		return -ENODEV;
978 
979 	ret = snprintf(page, PAGE_SIZE, "%s\n",
980 		tl_nexus->se_sess->se_node_acl->initiatorname);
981 
982 	return ret;
983 }
984 
985 static ssize_t tcm_loop_tpg_store_nexus(
986 	struct se_portal_group *se_tpg,
987 	const char *page,
988 	size_t count)
989 {
990 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
991 			struct tcm_loop_tpg, tl_se_tpg);
992 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
993 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
994 	int ret;
995 	/*
996 	 * Shutdown the active I_T nexus if 'NULL' is passed..
997 	 */
998 	if (!strncmp(page, "NULL", 4)) {
999 		ret = tcm_loop_drop_nexus(tl_tpg);
1000 		return (!ret) ? count : ret;
1001 	}
1002 	/*
1003 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1004 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1005 	 * tcm_loop_make_nexus()
1006 	 */
1007 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1008 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1009 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1010 		return -EINVAL;
1011 	}
1012 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1013 
1014 	ptr = strstr(i_port, "naa.");
1015 	if (ptr) {
1016 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1017 			pr_err("Passed SAS Initiator Port %s does not"
1018 				" match target port protoid: %s\n", i_port,
1019 				tcm_loop_dump_proto_id(tl_hba));
1020 			return -EINVAL;
1021 		}
1022 		port_ptr = &i_port[0];
1023 		goto check_newline;
1024 	}
1025 	ptr = strstr(i_port, "fc.");
1026 	if (ptr) {
1027 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1028 			pr_err("Passed FCP Initiator Port %s does not"
1029 				" match target port protoid: %s\n", i_port,
1030 				tcm_loop_dump_proto_id(tl_hba));
1031 			return -EINVAL;
1032 		}
1033 		port_ptr = &i_port[3]; /* Skip over "fc." */
1034 		goto check_newline;
1035 	}
1036 	ptr = strstr(i_port, "iqn.");
1037 	if (ptr) {
1038 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1039 			pr_err("Passed iSCSI Initiator Port %s does not"
1040 				" match target port protoid: %s\n", i_port,
1041 				tcm_loop_dump_proto_id(tl_hba));
1042 			return -EINVAL;
1043 		}
1044 		port_ptr = &i_port[0];
1045 		goto check_newline;
1046 	}
1047 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1048 			" %s\n", i_port);
1049 	return -EINVAL;
1050 	/*
1051 	 * Clear any trailing newline for the NAA WWN
1052 	 */
1053 check_newline:
1054 	if (i_port[strlen(i_port)-1] == '\n')
1055 		i_port[strlen(i_port)-1] = '\0';
1056 
1057 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1058 	if (ret < 0)
1059 		return ret;
1060 
1061 	return count;
1062 }
1063 
1064 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1065 
1066 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1067 	&tcm_loop_tpg_nexus.attr,
1068 	NULL,
1069 };
1070 
1071 /* Start items for tcm_loop_naa_cit */
1072 
1073 struct se_portal_group *tcm_loop_make_naa_tpg(
1074 	struct se_wwn *wwn,
1075 	struct config_group *group,
1076 	const char *name)
1077 {
1078 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1079 			struct tcm_loop_hba, tl_hba_wwn);
1080 	struct tcm_loop_tpg *tl_tpg;
1081 	char *tpgt_str, *end_ptr;
1082 	int ret;
1083 	unsigned short int tpgt;
1084 
1085 	tpgt_str = strstr(name, "tpgt_");
1086 	if (!tpgt_str) {
1087 		pr_err("Unable to locate \"tpgt_#\" directory"
1088 				" group\n");
1089 		return ERR_PTR(-EINVAL);
1090 	}
1091 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1092 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1093 
1094 	if (tpgt >= TL_TPGS_PER_HBA) {
1095 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1096 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1097 		return ERR_PTR(-EINVAL);
1098 	}
1099 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1100 	tl_tpg->tl_hba = tl_hba;
1101 	tl_tpg->tl_tpgt = tpgt;
1102 	/*
1103 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1104 	 */
1105 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1106 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1107 			TRANSPORT_TPG_TYPE_NORMAL);
1108 	if (ret < 0)
1109 		return ERR_PTR(-ENOMEM);
1110 
1111 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1112 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1113 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1114 
1115 	return &tl_tpg->tl_se_tpg;
1116 }
1117 
1118 void tcm_loop_drop_naa_tpg(
1119 	struct se_portal_group *se_tpg)
1120 {
1121 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1122 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1123 				struct tcm_loop_tpg, tl_se_tpg);
1124 	struct tcm_loop_hba *tl_hba;
1125 	unsigned short tpgt;
1126 
1127 	tl_hba = tl_tpg->tl_hba;
1128 	tpgt = tl_tpg->tl_tpgt;
1129 	/*
1130 	 * Release the I_T Nexus for the Virtual SAS link if present
1131 	 */
1132 	tcm_loop_drop_nexus(tl_tpg);
1133 	/*
1134 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1135 	 */
1136 	core_tpg_deregister(se_tpg);
1137 
1138 	tl_tpg->tl_hba = NULL;
1139 	tl_tpg->tl_tpgt = 0;
1140 
1141 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1142 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1143 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1144 }
1145 
1146 /* End items for tcm_loop_naa_cit */
1147 
1148 /* Start items for tcm_loop_cit */
1149 
1150 struct se_wwn *tcm_loop_make_scsi_hba(
1151 	struct target_fabric_configfs *tf,
1152 	struct config_group *group,
1153 	const char *name)
1154 {
1155 	struct tcm_loop_hba *tl_hba;
1156 	struct Scsi_Host *sh;
1157 	char *ptr;
1158 	int ret, off = 0;
1159 
1160 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1161 	if (!tl_hba) {
1162 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1163 		return ERR_PTR(-ENOMEM);
1164 	}
1165 	/*
1166 	 * Determine the emulated Protocol Identifier and Target Port Name
1167 	 * based on the incoming configfs directory name.
1168 	 */
1169 	ptr = strstr(name, "naa.");
1170 	if (ptr) {
1171 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1172 		goto check_len;
1173 	}
1174 	ptr = strstr(name, "fc.");
1175 	if (ptr) {
1176 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1177 		off = 3; /* Skip over "fc." */
1178 		goto check_len;
1179 	}
1180 	ptr = strstr(name, "iqn.");
1181 	if (!ptr) {
1182 		pr_err("Unable to locate prefix for emulated Target "
1183 				"Port: %s\n", name);
1184 		ret = -EINVAL;
1185 		goto out;
1186 	}
1187 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1188 
1189 check_len:
1190 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1191 		pr_err("Emulated NAA %s Address: %s, exceeds"
1192 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1193 			TL_WWN_ADDR_LEN);
1194 		ret = -EINVAL;
1195 		goto out;
1196 	}
1197 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1198 
1199 	/*
1200 	 * Call device_register(tl_hba->dev) to register the emulated
1201 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1202 	 * device_register() callbacks in tcm_loop_driver_probe()
1203 	 */
1204 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1205 	if (ret)
1206 		goto out;
1207 
1208 	sh = tl_hba->sh;
1209 	tcm_loop_hba_no_cnt++;
1210 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1211 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1212 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1213 
1214 	return &tl_hba->tl_hba_wwn;
1215 out:
1216 	kfree(tl_hba);
1217 	return ERR_PTR(ret);
1218 }
1219 
1220 void tcm_loop_drop_scsi_hba(
1221 	struct se_wwn *wwn)
1222 {
1223 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1224 				struct tcm_loop_hba, tl_hba_wwn);
1225 
1226 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1227 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1228 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1229 	/*
1230 	 * Call device_unregister() on the original tl_hba->dev.
1231 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1232 	 * release *tl_hba;
1233 	 */
1234 	device_unregister(&tl_hba->dev);
1235 }
1236 
1237 /* Start items for tcm_loop_cit */
1238 static ssize_t tcm_loop_wwn_show_attr_version(
1239 	struct target_fabric_configfs *tf,
1240 	char *page)
1241 {
1242 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1243 }
1244 
1245 TF_WWN_ATTR_RO(tcm_loop, version);
1246 
1247 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1248 	&tcm_loop_wwn_version.attr,
1249 	NULL,
1250 };
1251 
1252 /* End items for tcm_loop_cit */
1253 
1254 static int tcm_loop_register_configfs(void)
1255 {
1256 	struct target_fabric_configfs *fabric;
1257 	int ret;
1258 	/*
1259 	 * Set the TCM Loop HBA counter to zero
1260 	 */
1261 	tcm_loop_hba_no_cnt = 0;
1262 	/*
1263 	 * Register the top level struct config_item_type with TCM core
1264 	 */
1265 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1266 	if (IS_ERR(fabric)) {
1267 		pr_err("tcm_loop_register_configfs() failed!\n");
1268 		return PTR_ERR(fabric);
1269 	}
1270 	/*
1271 	 * Setup the fabric API of function pointers used by target_core_mod
1272 	 */
1273 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1274 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1275 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1276 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1277 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1278 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1279 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1280 					&tcm_loop_get_pr_transport_id_len;
1281 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1282 					&tcm_loop_parse_pr_out_transport_id;
1283 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1284 	fabric->tf_ops.tpg_check_demo_mode_cache =
1285 					&tcm_loop_check_demo_mode_cache;
1286 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1287 					&tcm_loop_check_demo_mode_write_protect;
1288 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1289 					&tcm_loop_check_prod_mode_write_protect;
1290 	/*
1291 	 * The TCM loopback fabric module runs in demo-mode to a local
1292 	 * virtual SCSI device, so fabric dependent initator ACLs are
1293 	 * not required.
1294 	 */
1295 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1296 	fabric->tf_ops.tpg_release_fabric_acl =
1297 					&tcm_loop_tpg_release_fabric_acl;
1298 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1299 	/*
1300 	 * Used for setting up remaining TCM resources in process context
1301 	 */
1302 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1303 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1304 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1305 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1306 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1307 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1308 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1309 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1310 	/*
1311 	 * Not used for TCM loopback
1312 	 */
1313 	fabric->tf_ops.set_default_node_attributes =
1314 					&tcm_loop_set_default_node_attributes;
1315 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1316 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1317 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1318 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1319 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1320 
1321 	/*
1322 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1323 	 */
1324 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1325 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1326 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1327 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1328 	/*
1329 	 * fabric_post_link() and fabric_pre_unlink() are used for
1330 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1331 	 */
1332 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1333 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1334 	fabric->tf_ops.fabric_make_np = NULL;
1335 	fabric->tf_ops.fabric_drop_np = NULL;
1336 	/*
1337 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1338 	 */
1339 	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1340 	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1341 	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1342 	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1343 	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1344 	/*
1345 	 * Once fabric->tf_ops has been setup, now register the fabric for
1346 	 * use within TCM
1347 	 */
1348 	ret = target_fabric_configfs_register(fabric);
1349 	if (ret < 0) {
1350 		pr_err("target_fabric_configfs_register() for"
1351 				" TCM_Loop failed!\n");
1352 		target_fabric_configfs_free(fabric);
1353 		return -1;
1354 	}
1355 	/*
1356 	 * Setup our local pointer to *fabric.
1357 	 */
1358 	tcm_loop_fabric_configfs = fabric;
1359 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1360 			" tcm_loop_fabric_configfs\n");
1361 	return 0;
1362 }
1363 
1364 static void tcm_loop_deregister_configfs(void)
1365 {
1366 	if (!tcm_loop_fabric_configfs)
1367 		return;
1368 
1369 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1370 	tcm_loop_fabric_configfs = NULL;
1371 	pr_debug("TCM_LOOP[0] - Cleared"
1372 				" tcm_loop_fabric_configfs\n");
1373 }
1374 
1375 static int __init tcm_loop_fabric_init(void)
1376 {
1377 	int ret = -ENOMEM;
1378 
1379 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1380 	if (!tcm_loop_workqueue)
1381 		goto out;
1382 
1383 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1384 				sizeof(struct tcm_loop_cmd),
1385 				__alignof__(struct tcm_loop_cmd),
1386 				0, NULL);
1387 	if (!tcm_loop_cmd_cache) {
1388 		pr_debug("kmem_cache_create() for"
1389 			" tcm_loop_cmd_cache failed\n");
1390 		goto out_destroy_workqueue;
1391 	}
1392 
1393 	ret = tcm_loop_alloc_core_bus();
1394 	if (ret)
1395 		goto out_destroy_cache;
1396 
1397 	ret = tcm_loop_register_configfs();
1398 	if (ret)
1399 		goto out_release_core_bus;
1400 
1401 	return 0;
1402 
1403 out_release_core_bus:
1404 	tcm_loop_release_core_bus();
1405 out_destroy_cache:
1406 	kmem_cache_destroy(tcm_loop_cmd_cache);
1407 out_destroy_workqueue:
1408 	destroy_workqueue(tcm_loop_workqueue);
1409 out:
1410 	return ret;
1411 }
1412 
1413 static void __exit tcm_loop_fabric_exit(void)
1414 {
1415 	tcm_loop_deregister_configfs();
1416 	tcm_loop_release_core_bus();
1417 	kmem_cache_destroy(tcm_loop_cmd_cache);
1418 	destroy_workqueue(tcm_loop_workqueue);
1419 }
1420 
1421 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1422 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1423 MODULE_LICENSE("GPL");
1424 module_init(tcm_loop_fabric_init);
1425 module_exit(tcm_loop_fabric_exit);
1426