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_tpg->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, TCM_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 			      int lun, int task, enum tcm_tmreq_table tmr)
222 {
223 	struct se_cmd *se_cmd = NULL;
224 	struct se_session *se_sess;
225 	struct se_portal_group *se_tpg;
226 	struct tcm_loop_nexus *tl_nexus;
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 	/*
232 	 * Locate the tl_nexus and se_sess pointers
233 	 */
234 	tl_nexus = tl_tpg->tl_nexus;
235 	if (!tl_nexus) {
236 		pr_err("Unable to perform device reset without"
237 				" active I_T Nexus\n");
238 		return ret;
239 	}
240 
241 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
242 	if (!tl_cmd) {
243 		pr_err("Unable to allocate memory for tl_cmd\n");
244 		return ret;
245 	}
246 
247 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
248 	if (!tl_tmr) {
249 		pr_err("Unable to allocate memory for tl_tmr\n");
250 		goto release;
251 	}
252 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
253 
254 	se_cmd = &tl_cmd->tl_se_cmd;
255 	se_tpg = &tl_tpg->tl_se_tpg;
256 	se_sess = tl_tpg->tl_nexus->se_sess;
257 	/*
258 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
259 	 */
260 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
261 				DMA_NONE, TCM_SIMPLE_TAG,
262 				&tl_cmd->tl_sense_buf[0]);
263 
264 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
265 	if (rc < 0)
266 		goto release;
267 
268 	if (tmr == TMR_ABORT_TASK)
269 		se_cmd->se_tmr_req->ref_task_tag = task;
270 
271 	/*
272 	 * Locate the underlying TCM struct se_lun
273 	 */
274 	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
275 		ret = TMR_LUN_DOES_NOT_EXIST;
276 		goto release;
277 	}
278 	/*
279 	 * Queue the TMR to TCM Core and sleep waiting for
280 	 * tcm_loop_queue_tm_rsp() to wake us up.
281 	 */
282 	transport_generic_handle_tmr(se_cmd);
283 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
284 	/*
285 	 * The TMR LUN_RESET has completed, check the response status and
286 	 * then release allocations.
287 	 */
288 	ret = se_cmd->se_tmr_req->response;
289 release:
290 	if (se_cmd)
291 		transport_generic_free_cmd(se_cmd, 1);
292 	else
293 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
294 	kfree(tl_tmr);
295 	return ret;
296 }
297 
298 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
299 {
300 	struct tcm_loop_hba *tl_hba;
301 	struct tcm_loop_tpg *tl_tpg;
302 	int ret = FAILED;
303 
304 	/*
305 	 * Locate the tcm_loop_hba_t pointer
306 	 */
307 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
308 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
309 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
310 				 sc->request->tag, TMR_ABORT_TASK);
311 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
312 }
313 
314 /*
315  * Called from SCSI EH process context to issue a LUN_RESET TMR
316  * to struct scsi_device
317  */
318 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
319 {
320 	struct tcm_loop_hba *tl_hba;
321 	struct tcm_loop_tpg *tl_tpg;
322 	int ret = FAILED;
323 
324 	/*
325 	 * Locate the tcm_loop_hba_t pointer
326 	 */
327 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
328 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
329 
330 	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
331 				 0, TMR_LUN_RESET);
332 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
333 }
334 
335 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
336 {
337 	struct tcm_loop_hba *tl_hba;
338 	struct tcm_loop_tpg *tl_tpg;
339 
340 	/*
341 	 * Locate the tcm_loop_hba_t pointer
342 	 */
343 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
344 	if (!tl_hba) {
345 		pr_err("Unable to perform device reset without"
346 				" active I_T Nexus\n");
347 		return FAILED;
348 	}
349 	/*
350 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
351 	 */
352 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
353 	if (tl_tpg) {
354 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
355 		return SUCCESS;
356 	}
357 	return FAILED;
358 }
359 
360 static int tcm_loop_slave_alloc(struct scsi_device *sd)
361 {
362 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
363 	return 0;
364 }
365 
366 static struct scsi_host_template tcm_loop_driver_template = {
367 	.show_info		= tcm_loop_show_info,
368 	.proc_name		= "tcm_loopback",
369 	.name			= "TCM_Loopback",
370 	.queuecommand		= tcm_loop_queuecommand,
371 	.change_queue_depth	= scsi_change_queue_depth,
372 	.eh_abort_handler = tcm_loop_abort_task,
373 	.eh_device_reset_handler = tcm_loop_device_reset,
374 	.eh_target_reset_handler = tcm_loop_target_reset,
375 	.can_queue		= 1024,
376 	.this_id		= -1,
377 	.sg_tablesize		= 256,
378 	.cmd_per_lun		= 1024,
379 	.max_sectors		= 0xFFFF,
380 	.use_clustering		= DISABLE_CLUSTERING,
381 	.slave_alloc		= tcm_loop_slave_alloc,
382 	.module			= THIS_MODULE,
383 	.use_blk_tags		= 1,
384 	.track_queue_depth	= 1,
385 };
386 
387 static int tcm_loop_driver_probe(struct device *dev)
388 {
389 	struct tcm_loop_hba *tl_hba;
390 	struct Scsi_Host *sh;
391 	int error, host_prot;
392 
393 	tl_hba = to_tcm_loop_hba(dev);
394 
395 	sh = scsi_host_alloc(&tcm_loop_driver_template,
396 			sizeof(struct tcm_loop_hba));
397 	if (!sh) {
398 		pr_err("Unable to allocate struct scsi_host\n");
399 		return -ENODEV;
400 	}
401 	tl_hba->sh = sh;
402 
403 	/*
404 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
405 	 */
406 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
407 	/*
408 	 * Setup single ID, Channel and LUN for now..
409 	 */
410 	sh->max_id = 2;
411 	sh->max_lun = 0;
412 	sh->max_channel = 0;
413 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
414 
415 	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
416 		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
417 		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
418 
419 	scsi_host_set_prot(sh, host_prot);
420 	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
421 
422 	error = scsi_add_host(sh, &tl_hba->dev);
423 	if (error) {
424 		pr_err("%s: scsi_add_host failed\n", __func__);
425 		scsi_host_put(sh);
426 		return -ENODEV;
427 	}
428 	return 0;
429 }
430 
431 static int tcm_loop_driver_remove(struct device *dev)
432 {
433 	struct tcm_loop_hba *tl_hba;
434 	struct Scsi_Host *sh;
435 
436 	tl_hba = to_tcm_loop_hba(dev);
437 	sh = tl_hba->sh;
438 
439 	scsi_remove_host(sh);
440 	scsi_host_put(sh);
441 	return 0;
442 }
443 
444 static void tcm_loop_release_adapter(struct device *dev)
445 {
446 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
447 
448 	kfree(tl_hba);
449 }
450 
451 /*
452  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
453  */
454 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
455 {
456 	int ret;
457 
458 	tl_hba->dev.bus = &tcm_loop_lld_bus;
459 	tl_hba->dev.parent = tcm_loop_primary;
460 	tl_hba->dev.release = &tcm_loop_release_adapter;
461 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
462 
463 	ret = device_register(&tl_hba->dev);
464 	if (ret) {
465 		pr_err("device_register() failed for"
466 				" tl_hba->dev: %d\n", ret);
467 		return -ENODEV;
468 	}
469 
470 	return 0;
471 }
472 
473 /*
474  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
475  * tcm_loop SCSI bus.
476  */
477 static int tcm_loop_alloc_core_bus(void)
478 {
479 	int ret;
480 
481 	tcm_loop_primary = root_device_register("tcm_loop_0");
482 	if (IS_ERR(tcm_loop_primary)) {
483 		pr_err("Unable to allocate tcm_loop_primary\n");
484 		return PTR_ERR(tcm_loop_primary);
485 	}
486 
487 	ret = bus_register(&tcm_loop_lld_bus);
488 	if (ret) {
489 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
490 		goto dev_unreg;
491 	}
492 
493 	ret = driver_register(&tcm_loop_driverfs);
494 	if (ret) {
495 		pr_err("driver_register() failed for"
496 				"tcm_loop_driverfs\n");
497 		goto bus_unreg;
498 	}
499 
500 	pr_debug("Initialized TCM Loop Core Bus\n");
501 	return ret;
502 
503 bus_unreg:
504 	bus_unregister(&tcm_loop_lld_bus);
505 dev_unreg:
506 	root_device_unregister(tcm_loop_primary);
507 	return ret;
508 }
509 
510 static void tcm_loop_release_core_bus(void)
511 {
512 	driver_unregister(&tcm_loop_driverfs);
513 	bus_unregister(&tcm_loop_lld_bus);
514 	root_device_unregister(tcm_loop_primary);
515 
516 	pr_debug("Releasing TCM Loop Core BUS\n");
517 }
518 
519 static char *tcm_loop_get_fabric_name(void)
520 {
521 	return "loopback";
522 }
523 
524 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
525 {
526 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
527 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
528 	/*
529 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
530 	 * time based on the protocol dependent prefix of the passed configfs group.
531 	 *
532 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
533 	 * ProtocolID using target_core_fabric_lib.c symbols.
534 	 */
535 	switch (tl_hba->tl_proto_id) {
536 	case SCSI_PROTOCOL_SAS:
537 		return sas_get_fabric_proto_ident(se_tpg);
538 	case SCSI_PROTOCOL_FCP:
539 		return fc_get_fabric_proto_ident(se_tpg);
540 	case SCSI_PROTOCOL_ISCSI:
541 		return iscsi_get_fabric_proto_ident(se_tpg);
542 	default:
543 		pr_err("Unknown tl_proto_id: 0x%02x, using"
544 			" SAS emulation\n", tl_hba->tl_proto_id);
545 		break;
546 	}
547 
548 	return sas_get_fabric_proto_ident(se_tpg);
549 }
550 
551 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
552 {
553 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
554 	/*
555 	 * Return the passed NAA identifier for the SAS Target Port
556 	 */
557 	return &tl_tpg->tl_hba->tl_wwn_address[0];
558 }
559 
560 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
561 {
562 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
563 	/*
564 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
565 	 * to represent the SCSI Target Port.
566 	 */
567 	return tl_tpg->tl_tpgt;
568 }
569 
570 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
571 {
572 	return 1;
573 }
574 
575 static u32 tcm_loop_get_pr_transport_id(
576 	struct se_portal_group *se_tpg,
577 	struct se_node_acl *se_nacl,
578 	struct t10_pr_registration *pr_reg,
579 	int *format_code,
580 	unsigned char *buf)
581 {
582 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
583 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
584 
585 	switch (tl_hba->tl_proto_id) {
586 	case SCSI_PROTOCOL_SAS:
587 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
588 					format_code, buf);
589 	case SCSI_PROTOCOL_FCP:
590 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
591 					format_code, buf);
592 	case SCSI_PROTOCOL_ISCSI:
593 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
594 					format_code, buf);
595 	default:
596 		pr_err("Unknown tl_proto_id: 0x%02x, using"
597 			" SAS emulation\n", tl_hba->tl_proto_id);
598 		break;
599 	}
600 
601 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
602 			format_code, buf);
603 }
604 
605 static u32 tcm_loop_get_pr_transport_id_len(
606 	struct se_portal_group *se_tpg,
607 	struct se_node_acl *se_nacl,
608 	struct t10_pr_registration *pr_reg,
609 	int *format_code)
610 {
611 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
612 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
613 
614 	switch (tl_hba->tl_proto_id) {
615 	case SCSI_PROTOCOL_SAS:
616 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
617 					format_code);
618 	case SCSI_PROTOCOL_FCP:
619 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
620 					format_code);
621 	case SCSI_PROTOCOL_ISCSI:
622 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
623 					format_code);
624 	default:
625 		pr_err("Unknown tl_proto_id: 0x%02x, using"
626 			" SAS emulation\n", tl_hba->tl_proto_id);
627 		break;
628 	}
629 
630 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
631 			format_code);
632 }
633 
634 /*
635  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
636  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
637  */
638 static char *tcm_loop_parse_pr_out_transport_id(
639 	struct se_portal_group *se_tpg,
640 	const char *buf,
641 	u32 *out_tid_len,
642 	char **port_nexus_ptr)
643 {
644 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
645 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
646 
647 	switch (tl_hba->tl_proto_id) {
648 	case SCSI_PROTOCOL_SAS:
649 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
650 					port_nexus_ptr);
651 	case SCSI_PROTOCOL_FCP:
652 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
653 					port_nexus_ptr);
654 	case SCSI_PROTOCOL_ISCSI:
655 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
656 					port_nexus_ptr);
657 	default:
658 		pr_err("Unknown tl_proto_id: 0x%02x, using"
659 			" SAS emulation\n", tl_hba->tl_proto_id);
660 		break;
661 	}
662 
663 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
664 			port_nexus_ptr);
665 }
666 
667 /*
668  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
669  * based upon the incoming fabric dependent SCSI Initiator Port
670  */
671 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
672 {
673 	return 1;
674 }
675 
676 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
677 {
678 	return 0;
679 }
680 
681 /*
682  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
683  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
684  */
685 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
686 {
687 	return 0;
688 }
689 
690 /*
691  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
692  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
693  * It has been added here as a nop for target_fabric_tf_ops_check()
694  */
695 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
696 {
697 	return 0;
698 }
699 
700 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
701 	struct se_portal_group *se_tpg)
702 {
703 	struct tcm_loop_nacl *tl_nacl;
704 
705 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
706 	if (!tl_nacl) {
707 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
708 		return NULL;
709 	}
710 
711 	return &tl_nacl->se_node_acl;
712 }
713 
714 static void tcm_loop_tpg_release_fabric_acl(
715 	struct se_portal_group *se_tpg,
716 	struct se_node_acl *se_nacl)
717 {
718 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
719 				struct tcm_loop_nacl, se_node_acl);
720 
721 	kfree(tl_nacl);
722 }
723 
724 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
725 {
726 	return 1;
727 }
728 
729 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
730 {
731 	return 1;
732 }
733 
734 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
735 {
736 	return;
737 }
738 
739 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
740 {
741 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
742 			struct tcm_loop_cmd, tl_se_cmd);
743 
744 	return tl_cmd->sc_cmd_tag;
745 }
746 
747 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
748 {
749 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
750 			struct tcm_loop_cmd, tl_se_cmd);
751 
752 	return tl_cmd->sc_cmd_state;
753 }
754 
755 static int tcm_loop_shutdown_session(struct se_session *se_sess)
756 {
757 	return 0;
758 }
759 
760 static void tcm_loop_close_session(struct se_session *se_sess)
761 {
762 	return;
763 };
764 
765 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
766 {
767 	/*
768 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
769 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
770 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
771 	 * format with transport_generic_map_mem_to_cmd().
772 	 *
773 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
774 	 * object execution queue.
775 	 */
776 	target_execute_cmd(se_cmd);
777 	return 0;
778 }
779 
780 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
781 {
782 	return 0;
783 }
784 
785 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
786 {
787 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
788 				struct tcm_loop_cmd, tl_se_cmd);
789 	struct scsi_cmnd *sc = tl_cmd->sc;
790 
791 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
792 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
793 
794 	sc->result = SAM_STAT_GOOD;
795 	set_host_byte(sc, DID_OK);
796 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
797 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
798 		scsi_set_resid(sc, se_cmd->residual_count);
799 	sc->scsi_done(sc);
800 	return 0;
801 }
802 
803 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
804 {
805 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
806 				struct tcm_loop_cmd, tl_se_cmd);
807 	struct scsi_cmnd *sc = tl_cmd->sc;
808 
809 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
810 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
811 
812 	if (se_cmd->sense_buffer &&
813 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
814 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
815 
816 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
817 				SCSI_SENSE_BUFFERSIZE);
818 		sc->result = SAM_STAT_CHECK_CONDITION;
819 		set_driver_byte(sc, DRIVER_SENSE);
820 	} else
821 		sc->result = se_cmd->scsi_status;
822 
823 	set_host_byte(sc, DID_OK);
824 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
825 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
826 		scsi_set_resid(sc, se_cmd->residual_count);
827 	sc->scsi_done(sc);
828 	return 0;
829 }
830 
831 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
832 {
833 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
834 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
835 	/*
836 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
837 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
838 	 */
839 	atomic_set(&tl_tmr->tmr_complete, 1);
840 	wake_up(&tl_tmr->tl_tmr_wait);
841 }
842 
843 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
844 {
845 	return;
846 }
847 
848 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
849 {
850 	switch (tl_hba->tl_proto_id) {
851 	case SCSI_PROTOCOL_SAS:
852 		return "SAS";
853 	case SCSI_PROTOCOL_FCP:
854 		return "FCP";
855 	case SCSI_PROTOCOL_ISCSI:
856 		return "iSCSI";
857 	default:
858 		break;
859 	}
860 
861 	return "Unknown";
862 }
863 
864 /* Start items for tcm_loop_port_cit */
865 
866 static int tcm_loop_port_link(
867 	struct se_portal_group *se_tpg,
868 	struct se_lun *lun)
869 {
870 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
871 				struct tcm_loop_tpg, tl_se_tpg);
872 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
873 
874 	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
875 	/*
876 	 * Add Linux/SCSI struct scsi_device by HCTL
877 	 */
878 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
879 
880 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
881 	return 0;
882 }
883 
884 static void tcm_loop_port_unlink(
885 	struct se_portal_group *se_tpg,
886 	struct se_lun *se_lun)
887 {
888 	struct scsi_device *sd;
889 	struct tcm_loop_hba *tl_hba;
890 	struct tcm_loop_tpg *tl_tpg;
891 
892 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
893 	tl_hba = tl_tpg->tl_hba;
894 
895 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
896 				se_lun->unpacked_lun);
897 	if (!sd) {
898 		pr_err("Unable to locate struct scsi_device for %d:%d:"
899 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
900 		return;
901 	}
902 	/*
903 	 * Remove Linux/SCSI struct scsi_device by HCTL
904 	 */
905 	scsi_remove_device(sd);
906 	scsi_device_put(sd);
907 
908 	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
909 
910 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
911 }
912 
913 /* End items for tcm_loop_port_cit */
914 
915 /* Start items for tcm_loop_nexus_cit */
916 
917 static int tcm_loop_make_nexus(
918 	struct tcm_loop_tpg *tl_tpg,
919 	const char *name)
920 {
921 	struct se_portal_group *se_tpg;
922 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
923 	struct tcm_loop_nexus *tl_nexus;
924 	int ret = -ENOMEM;
925 
926 	if (tl_tpg->tl_nexus) {
927 		pr_debug("tl_tpg->tl_nexus already exists\n");
928 		return -EEXIST;
929 	}
930 	se_tpg = &tl_tpg->tl_se_tpg;
931 
932 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
933 	if (!tl_nexus) {
934 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
935 		return -ENOMEM;
936 	}
937 	/*
938 	 * Initialize the struct se_session pointer
939 	 */
940 	tl_nexus->se_sess = transport_init_session(TARGET_PROT_ALL);
941 	if (IS_ERR(tl_nexus->se_sess)) {
942 		ret = PTR_ERR(tl_nexus->se_sess);
943 		goto out;
944 	}
945 	/*
946 	 * Since we are running in 'demo mode' this call with generate a
947 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
948 	 * Initiator port name of the passed configfs group 'name'.
949 	 */
950 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
951 				se_tpg, (unsigned char *)name);
952 	if (!tl_nexus->se_sess->se_node_acl) {
953 		transport_free_session(tl_nexus->se_sess);
954 		goto out;
955 	}
956 	/*
957 	 * Now, register the SAS I_T Nexus as active with the call to
958 	 * transport_register_session()
959 	 */
960 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
961 			tl_nexus->se_sess, tl_nexus);
962 	tl_tpg->tl_nexus = tl_nexus;
963 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
964 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
965 		name);
966 	return 0;
967 
968 out:
969 	kfree(tl_nexus);
970 	return ret;
971 }
972 
973 static int tcm_loop_drop_nexus(
974 	struct tcm_loop_tpg *tpg)
975 {
976 	struct se_session *se_sess;
977 	struct tcm_loop_nexus *tl_nexus;
978 
979 	tl_nexus = tpg->tl_nexus;
980 	if (!tl_nexus)
981 		return -ENODEV;
982 
983 	se_sess = tl_nexus->se_sess;
984 	if (!se_sess)
985 		return -ENODEV;
986 
987 	if (atomic_read(&tpg->tl_tpg_port_count)) {
988 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
989 			" active TPG port count: %d\n",
990 			atomic_read(&tpg->tl_tpg_port_count));
991 		return -EPERM;
992 	}
993 
994 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
995 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tpg->tl_hba),
996 		tl_nexus->se_sess->se_node_acl->initiatorname);
997 	/*
998 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
999 	 */
1000 	transport_deregister_session(tl_nexus->se_sess);
1001 	tpg->tl_nexus = NULL;
1002 	kfree(tl_nexus);
1003 	return 0;
1004 }
1005 
1006 /* End items for tcm_loop_nexus_cit */
1007 
1008 static ssize_t tcm_loop_tpg_show_nexus(
1009 	struct se_portal_group *se_tpg,
1010 	char *page)
1011 {
1012 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1013 			struct tcm_loop_tpg, tl_se_tpg);
1014 	struct tcm_loop_nexus *tl_nexus;
1015 	ssize_t ret;
1016 
1017 	tl_nexus = tl_tpg->tl_nexus;
1018 	if (!tl_nexus)
1019 		return -ENODEV;
1020 
1021 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1022 		tl_nexus->se_sess->se_node_acl->initiatorname);
1023 
1024 	return ret;
1025 }
1026 
1027 static ssize_t tcm_loop_tpg_store_nexus(
1028 	struct se_portal_group *se_tpg,
1029 	const char *page,
1030 	size_t count)
1031 {
1032 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1033 			struct tcm_loop_tpg, tl_se_tpg);
1034 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1035 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1036 	int ret;
1037 	/*
1038 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1039 	 */
1040 	if (!strncmp(page, "NULL", 4)) {
1041 		ret = tcm_loop_drop_nexus(tl_tpg);
1042 		return (!ret) ? count : ret;
1043 	}
1044 	/*
1045 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1046 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1047 	 * tcm_loop_make_nexus()
1048 	 */
1049 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1050 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1051 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1052 		return -EINVAL;
1053 	}
1054 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1055 
1056 	ptr = strstr(i_port, "naa.");
1057 	if (ptr) {
1058 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1059 			pr_err("Passed SAS Initiator Port %s does not"
1060 				" match target port protoid: %s\n", i_port,
1061 				tcm_loop_dump_proto_id(tl_hba));
1062 			return -EINVAL;
1063 		}
1064 		port_ptr = &i_port[0];
1065 		goto check_newline;
1066 	}
1067 	ptr = strstr(i_port, "fc.");
1068 	if (ptr) {
1069 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1070 			pr_err("Passed FCP Initiator Port %s does not"
1071 				" match target port protoid: %s\n", i_port,
1072 				tcm_loop_dump_proto_id(tl_hba));
1073 			return -EINVAL;
1074 		}
1075 		port_ptr = &i_port[3]; /* Skip over "fc." */
1076 		goto check_newline;
1077 	}
1078 	ptr = strstr(i_port, "iqn.");
1079 	if (ptr) {
1080 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1081 			pr_err("Passed iSCSI Initiator Port %s does not"
1082 				" match target port protoid: %s\n", i_port,
1083 				tcm_loop_dump_proto_id(tl_hba));
1084 			return -EINVAL;
1085 		}
1086 		port_ptr = &i_port[0];
1087 		goto check_newline;
1088 	}
1089 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1090 			" %s\n", i_port);
1091 	return -EINVAL;
1092 	/*
1093 	 * Clear any trailing newline for the NAA WWN
1094 	 */
1095 check_newline:
1096 	if (i_port[strlen(i_port)-1] == '\n')
1097 		i_port[strlen(i_port)-1] = '\0';
1098 
1099 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1100 	if (ret < 0)
1101 		return ret;
1102 
1103 	return count;
1104 }
1105 
1106 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1107 
1108 static ssize_t tcm_loop_tpg_show_transport_status(
1109 	struct se_portal_group *se_tpg,
1110 	char *page)
1111 {
1112 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1113 			struct tcm_loop_tpg, tl_se_tpg);
1114 	const char *status = NULL;
1115 	ssize_t ret = -EINVAL;
1116 
1117 	switch (tl_tpg->tl_transport_status) {
1118 	case TCM_TRANSPORT_ONLINE:
1119 		status = "online";
1120 		break;
1121 	case TCM_TRANSPORT_OFFLINE:
1122 		status = "offline";
1123 		break;
1124 	default:
1125 		break;
1126 	}
1127 
1128 	if (status)
1129 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1130 
1131 	return ret;
1132 }
1133 
1134 static ssize_t tcm_loop_tpg_store_transport_status(
1135 	struct se_portal_group *se_tpg,
1136 	const char *page,
1137 	size_t count)
1138 {
1139 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1140 			struct tcm_loop_tpg, tl_se_tpg);
1141 
1142 	if (!strncmp(page, "online", 6)) {
1143 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1144 		return count;
1145 	}
1146 	if (!strncmp(page, "offline", 7)) {
1147 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1148 		return count;
1149 	}
1150 	return -EINVAL;
1151 }
1152 
1153 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1154 
1155 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1156 	&tcm_loop_tpg_nexus.attr,
1157 	&tcm_loop_tpg_transport_status.attr,
1158 	NULL,
1159 };
1160 
1161 /* Start items for tcm_loop_naa_cit */
1162 
1163 static struct se_portal_group *tcm_loop_make_naa_tpg(
1164 	struct se_wwn *wwn,
1165 	struct config_group *group,
1166 	const char *name)
1167 {
1168 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1169 			struct tcm_loop_hba, tl_hba_wwn);
1170 	struct tcm_loop_tpg *tl_tpg;
1171 	char *tpgt_str, *end_ptr;
1172 	int ret;
1173 	unsigned short int tpgt;
1174 
1175 	tpgt_str = strstr(name, "tpgt_");
1176 	if (!tpgt_str) {
1177 		pr_err("Unable to locate \"tpgt_#\" directory"
1178 				" group\n");
1179 		return ERR_PTR(-EINVAL);
1180 	}
1181 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1182 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1183 
1184 	if (tpgt >= TL_TPGS_PER_HBA) {
1185 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1186 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1187 		return ERR_PTR(-EINVAL);
1188 	}
1189 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1190 	tl_tpg->tl_hba = tl_hba;
1191 	tl_tpg->tl_tpgt = tpgt;
1192 	/*
1193 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1194 	 */
1195 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1196 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1197 			TRANSPORT_TPG_TYPE_NORMAL);
1198 	if (ret < 0)
1199 		return ERR_PTR(-ENOMEM);
1200 
1201 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1202 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1203 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1204 
1205 	return &tl_tpg->tl_se_tpg;
1206 }
1207 
1208 static void tcm_loop_drop_naa_tpg(
1209 	struct se_portal_group *se_tpg)
1210 {
1211 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1212 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1213 				struct tcm_loop_tpg, tl_se_tpg);
1214 	struct tcm_loop_hba *tl_hba;
1215 	unsigned short tpgt;
1216 
1217 	tl_hba = tl_tpg->tl_hba;
1218 	tpgt = tl_tpg->tl_tpgt;
1219 	/*
1220 	 * Release the I_T Nexus for the Virtual SAS link if present
1221 	 */
1222 	tcm_loop_drop_nexus(tl_tpg);
1223 	/*
1224 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1225 	 */
1226 	core_tpg_deregister(se_tpg);
1227 
1228 	tl_tpg->tl_hba = NULL;
1229 	tl_tpg->tl_tpgt = 0;
1230 
1231 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1232 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1233 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1234 }
1235 
1236 /* End items for tcm_loop_naa_cit */
1237 
1238 /* Start items for tcm_loop_cit */
1239 
1240 static struct se_wwn *tcm_loop_make_scsi_hba(
1241 	struct target_fabric_configfs *tf,
1242 	struct config_group *group,
1243 	const char *name)
1244 {
1245 	struct tcm_loop_hba *tl_hba;
1246 	struct Scsi_Host *sh;
1247 	char *ptr;
1248 	int ret, off = 0;
1249 
1250 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1251 	if (!tl_hba) {
1252 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1253 		return ERR_PTR(-ENOMEM);
1254 	}
1255 	/*
1256 	 * Determine the emulated Protocol Identifier and Target Port Name
1257 	 * based on the incoming configfs directory name.
1258 	 */
1259 	ptr = strstr(name, "naa.");
1260 	if (ptr) {
1261 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1262 		goto check_len;
1263 	}
1264 	ptr = strstr(name, "fc.");
1265 	if (ptr) {
1266 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1267 		off = 3; /* Skip over "fc." */
1268 		goto check_len;
1269 	}
1270 	ptr = strstr(name, "iqn.");
1271 	if (!ptr) {
1272 		pr_err("Unable to locate prefix for emulated Target "
1273 				"Port: %s\n", name);
1274 		ret = -EINVAL;
1275 		goto out;
1276 	}
1277 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1278 
1279 check_len:
1280 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1281 		pr_err("Emulated NAA %s Address: %s, exceeds"
1282 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1283 			TL_WWN_ADDR_LEN);
1284 		ret = -EINVAL;
1285 		goto out;
1286 	}
1287 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1288 
1289 	/*
1290 	 * Call device_register(tl_hba->dev) to register the emulated
1291 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1292 	 * device_register() callbacks in tcm_loop_driver_probe()
1293 	 */
1294 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1295 	if (ret)
1296 		goto out;
1297 
1298 	sh = tl_hba->sh;
1299 	tcm_loop_hba_no_cnt++;
1300 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1301 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1302 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1303 
1304 	return &tl_hba->tl_hba_wwn;
1305 out:
1306 	kfree(tl_hba);
1307 	return ERR_PTR(ret);
1308 }
1309 
1310 static void tcm_loop_drop_scsi_hba(
1311 	struct se_wwn *wwn)
1312 {
1313 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1314 				struct tcm_loop_hba, tl_hba_wwn);
1315 
1316 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1317 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1318 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1319 	/*
1320 	 * Call device_unregister() on the original tl_hba->dev.
1321 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1322 	 * release *tl_hba;
1323 	 */
1324 	device_unregister(&tl_hba->dev);
1325 }
1326 
1327 /* Start items for tcm_loop_cit */
1328 static ssize_t tcm_loop_wwn_show_attr_version(
1329 	struct target_fabric_configfs *tf,
1330 	char *page)
1331 {
1332 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1333 }
1334 
1335 TF_WWN_ATTR_RO(tcm_loop, version);
1336 
1337 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1338 	&tcm_loop_wwn_version.attr,
1339 	NULL,
1340 };
1341 
1342 /* End items for tcm_loop_cit */
1343 
1344 static int tcm_loop_register_configfs(void)
1345 {
1346 	struct target_fabric_configfs *fabric;
1347 	int ret;
1348 	/*
1349 	 * Set the TCM Loop HBA counter to zero
1350 	 */
1351 	tcm_loop_hba_no_cnt = 0;
1352 	/*
1353 	 * Register the top level struct config_item_type with TCM core
1354 	 */
1355 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1356 	if (IS_ERR(fabric)) {
1357 		pr_err("tcm_loop_register_configfs() failed!\n");
1358 		return PTR_ERR(fabric);
1359 	}
1360 	/*
1361 	 * Setup the fabric API of function pointers used by target_core_mod
1362 	 */
1363 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1364 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1365 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1366 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1367 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1368 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1369 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1370 					&tcm_loop_get_pr_transport_id_len;
1371 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1372 					&tcm_loop_parse_pr_out_transport_id;
1373 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1374 	fabric->tf_ops.tpg_check_demo_mode_cache =
1375 					&tcm_loop_check_demo_mode_cache;
1376 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1377 					&tcm_loop_check_demo_mode_write_protect;
1378 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1379 					&tcm_loop_check_prod_mode_write_protect;
1380 	/*
1381 	 * The TCM loopback fabric module runs in demo-mode to a local
1382 	 * virtual SCSI device, so fabric dependent initator ACLs are
1383 	 * not required.
1384 	 */
1385 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1386 	fabric->tf_ops.tpg_release_fabric_acl =
1387 					&tcm_loop_tpg_release_fabric_acl;
1388 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1389 	/*
1390 	 * Used for setting up remaining TCM resources in process context
1391 	 */
1392 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1393 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1394 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1395 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1396 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1397 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1398 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1399 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1400 	/*
1401 	 * Not used for TCM loopback
1402 	 */
1403 	fabric->tf_ops.set_default_node_attributes =
1404 					&tcm_loop_set_default_node_attributes;
1405 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1406 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1407 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1408 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1409 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1410 	fabric->tf_ops.aborted_task = &tcm_loop_aborted_task;
1411 
1412 	/*
1413 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1414 	 */
1415 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1416 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1417 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1418 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1419 	/*
1420 	 * fabric_post_link() and fabric_pre_unlink() are used for
1421 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1422 	 */
1423 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1424 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1425 	fabric->tf_ops.fabric_make_np = NULL;
1426 	fabric->tf_ops.fabric_drop_np = NULL;
1427 	/*
1428 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1429 	 */
1430 	fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1431 	fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1432 	fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1433 	fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1434 	fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1435 	/*
1436 	 * Once fabric->tf_ops has been setup, now register the fabric for
1437 	 * use within TCM
1438 	 */
1439 	ret = target_fabric_configfs_register(fabric);
1440 	if (ret < 0) {
1441 		pr_err("target_fabric_configfs_register() for"
1442 				" TCM_Loop failed!\n");
1443 		target_fabric_configfs_free(fabric);
1444 		return -1;
1445 	}
1446 	/*
1447 	 * Setup our local pointer to *fabric.
1448 	 */
1449 	tcm_loop_fabric_configfs = fabric;
1450 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1451 			" tcm_loop_fabric_configfs\n");
1452 	return 0;
1453 }
1454 
1455 static void tcm_loop_deregister_configfs(void)
1456 {
1457 	if (!tcm_loop_fabric_configfs)
1458 		return;
1459 
1460 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1461 	tcm_loop_fabric_configfs = NULL;
1462 	pr_debug("TCM_LOOP[0] - Cleared"
1463 				" tcm_loop_fabric_configfs\n");
1464 }
1465 
1466 static int __init tcm_loop_fabric_init(void)
1467 {
1468 	int ret = -ENOMEM;
1469 
1470 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1471 	if (!tcm_loop_workqueue)
1472 		goto out;
1473 
1474 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1475 				sizeof(struct tcm_loop_cmd),
1476 				__alignof__(struct tcm_loop_cmd),
1477 				0, NULL);
1478 	if (!tcm_loop_cmd_cache) {
1479 		pr_debug("kmem_cache_create() for"
1480 			" tcm_loop_cmd_cache failed\n");
1481 		goto out_destroy_workqueue;
1482 	}
1483 
1484 	ret = tcm_loop_alloc_core_bus();
1485 	if (ret)
1486 		goto out_destroy_cache;
1487 
1488 	ret = tcm_loop_register_configfs();
1489 	if (ret)
1490 		goto out_release_core_bus;
1491 
1492 	return 0;
1493 
1494 out_release_core_bus:
1495 	tcm_loop_release_core_bus();
1496 out_destroy_cache:
1497 	kmem_cache_destroy(tcm_loop_cmd_cache);
1498 out_destroy_workqueue:
1499 	destroy_workqueue(tcm_loop_workqueue);
1500 out:
1501 	return ret;
1502 }
1503 
1504 static void __exit tcm_loop_fabric_exit(void)
1505 {
1506 	tcm_loop_deregister_configfs();
1507 	tcm_loop_release_core_bus();
1508 	kmem_cache_destroy(tcm_loop_cmd_cache);
1509 	destroy_workqueue(tcm_loop_workqueue);
1510 }
1511 
1512 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1513 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1514 MODULE_LICENSE("GPL");
1515 module_init(tcm_loop_fabric_init);
1516 module_exit(tcm_loop_fabric_exit);
1517