1 /*******************************************************************************
2  *
3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
4  * for emulated SAS initiator ports
5  *
6  * © Copyright 2011-2013 Datera, Inc.
7  *
8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
9  *
10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  ****************************************************************************/
22 
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/configfs.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_cmnd.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_fabric.h>
37 #include <target/target_core_fabric_configfs.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "tcm_loop.h"
41 
42 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
43 
44 /* Local pointer to allocated TCM configfs fabric module */
45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
46 
47 static struct workqueue_struct *tcm_loop_workqueue;
48 static struct kmem_cache *tcm_loop_cmd_cache;
49 
50 static int tcm_loop_hba_no_cnt;
51 
52 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
53 
54 /*
55  * Called from struct target_core_fabric_ops->check_stop_free()
56  */
57 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
58 {
59 	/*
60 	 * Do not release struct se_cmd's containing a valid TMR
61 	 * pointer.  These will be released directly in tcm_loop_device_reset()
62 	 * with transport_generic_free_cmd().
63 	 */
64 	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
65 		return 0;
66 	/*
67 	 * Release the struct se_cmd, which will make a callback to release
68 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
69 	 */
70 	transport_generic_free_cmd(se_cmd, 0);
71 	return 1;
72 }
73 
74 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
75 {
76 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
77 				struct tcm_loop_cmd, tl_se_cmd);
78 
79 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
80 }
81 
82 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
83 {
84 	seq_printf(m, "tcm_loop_proc_info()\n");
85 	return 0;
86 }
87 
88 static int tcm_loop_driver_probe(struct device *);
89 static int tcm_loop_driver_remove(struct device *);
90 
91 static int pseudo_lld_bus_match(struct device *dev,
92 				struct device_driver *dev_driver)
93 {
94 	return 1;
95 }
96 
97 static struct bus_type tcm_loop_lld_bus = {
98 	.name			= "tcm_loop_bus",
99 	.match			= pseudo_lld_bus_match,
100 	.probe			= tcm_loop_driver_probe,
101 	.remove			= tcm_loop_driver_remove,
102 };
103 
104 static struct device_driver tcm_loop_driverfs = {
105 	.name			= "tcm_loop",
106 	.bus			= &tcm_loop_lld_bus,
107 };
108 /*
109  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
110  */
111 struct device *tcm_loop_primary;
112 
113 /*
114  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
115  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
116  */
117 static int tcm_loop_change_queue_depth(
118 	struct scsi_device *sdev,
119 	int depth,
120 	int reason)
121 {
122 	switch (reason) {
123 	case SCSI_QDEPTH_DEFAULT:
124 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
125 		break;
126 	case SCSI_QDEPTH_QFULL:
127 		scsi_track_queue_full(sdev, depth);
128 		break;
129 	case SCSI_QDEPTH_RAMP_UP:
130 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
131 		break;
132 	default:
133 		return -EOPNOTSUPP;
134 	}
135 	return sdev->queue_depth;
136 }
137 
138 static int tcm_loop_change_queue_type(struct scsi_device *sdev, int tag)
139 {
140 	if (sdev->tagged_supported) {
141 		scsi_set_tag_type(sdev, tag);
142 
143 		if (tag)
144 			scsi_activate_tcq(sdev, sdev->queue_depth);
145 		else
146 			scsi_deactivate_tcq(sdev, sdev->queue_depth);
147 	} else
148 		tag = 0;
149 
150 	return tag;
151 }
152 
153 /*
154  * Locate the SAM Task Attr from struct scsi_cmnd *
155  */
156 static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
157 {
158 	if (sc->device->tagged_supported) {
159 		switch (sc->tag) {
160 		case HEAD_OF_QUEUE_TAG:
161 			return MSG_HEAD_TAG;
162 		case ORDERED_QUEUE_TAG:
163 			return MSG_ORDERED_TAG;
164 		default:
165 			break;
166 		}
167 	}
168 
169 	return MSG_SIMPLE_TAG;
170 }
171 
172 static void tcm_loop_submission_work(struct work_struct *work)
173 {
174 	struct tcm_loop_cmd *tl_cmd =
175 		container_of(work, struct tcm_loop_cmd, work);
176 	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
177 	struct scsi_cmnd *sc = tl_cmd->sc;
178 	struct tcm_loop_nexus *tl_nexus;
179 	struct tcm_loop_hba *tl_hba;
180 	struct tcm_loop_tpg *tl_tpg;
181 	struct scatterlist *sgl_bidi = NULL;
182 	u32 sgl_bidi_count = 0;
183 	int rc;
184 
185 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
186 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
187 
188 	/*
189 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
190 	 * has already been configured via tcm_loop_make_naa_tpg().
191 	 */
192 	if (!tl_tpg->tl_hba) {
193 		set_host_byte(sc, DID_NO_CONNECT);
194 		goto out_done;
195 	}
196 	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
197 		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
198 		goto out_done;
199 	}
200 	tl_nexus = tl_hba->tl_nexus;
201 	if (!tl_nexus) {
202 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
203 				" does not exist\n");
204 		set_host_byte(sc, DID_ERROR);
205 		goto out_done;
206 	}
207 	if (scsi_bidi_cmnd(sc)) {
208 		struct scsi_data_buffer *sdb = scsi_in(sc);
209 
210 		sgl_bidi = sdb->table.sgl;
211 		sgl_bidi_count = sdb->table.nents;
212 		se_cmd->se_cmd_flags |= SCF_BIDI;
213 
214 	}
215 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
216 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
217 			scsi_bufflen(sc), tcm_loop_sam_attr(sc),
218 			sc->sc_data_direction, 0,
219 			scsi_sglist(sc), scsi_sg_count(sc),
220 			sgl_bidi, sgl_bidi_count);
221 	if (rc < 0) {
222 		set_host_byte(sc, DID_NO_CONNECT);
223 		goto out_done;
224 	}
225 	return;
226 
227 out_done:
228 	sc->scsi_done(sc);
229 	return;
230 }
231 
232 /*
233  * ->queuecommand can be and usually is called from interrupt context, so
234  * defer the actual submission to a workqueue.
235  */
236 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
237 {
238 	struct tcm_loop_cmd *tl_cmd;
239 
240 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
241 		" scsi_buf_len: %u\n", sc->device->host->host_no,
242 		sc->device->id, sc->device->channel, sc->device->lun,
243 		sc->cmnd[0], scsi_bufflen(sc));
244 
245 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
246 	if (!tl_cmd) {
247 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
248 		set_host_byte(sc, DID_ERROR);
249 		sc->scsi_done(sc);
250 		return 0;
251 	}
252 
253 	tl_cmd->sc = sc;
254 	tl_cmd->sc_cmd_tag = sc->tag;
255 	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
256 	queue_work(tcm_loop_workqueue, &tl_cmd->work);
257 	return 0;
258 }
259 
260 /*
261  * Called from SCSI EH process context to issue a LUN_RESET TMR
262  * to struct scsi_device
263  */
264 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
265 			      struct tcm_loop_nexus *tl_nexus,
266 			      int lun, int task, enum tcm_tmreq_table tmr)
267 {
268 	struct se_cmd *se_cmd = NULL;
269 	struct se_session *se_sess;
270 	struct se_portal_group *se_tpg;
271 	struct tcm_loop_cmd *tl_cmd = NULL;
272 	struct tcm_loop_tmr *tl_tmr = NULL;
273 	int ret = TMR_FUNCTION_FAILED, rc;
274 
275 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
276 	if (!tl_cmd) {
277 		pr_err("Unable to allocate memory for tl_cmd\n");
278 		return ret;
279 	}
280 
281 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
282 	if (!tl_tmr) {
283 		pr_err("Unable to allocate memory for tl_tmr\n");
284 		goto release;
285 	}
286 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
287 
288 	se_cmd = &tl_cmd->tl_se_cmd;
289 	se_tpg = &tl_tpg->tl_se_tpg;
290 	se_sess = tl_nexus->se_sess;
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, GFP_KERNEL);
299 	if (rc < 0)
300 		goto release;
301 
302 	if (tmr == TMR_ABORT_TASK)
303 		se_cmd->se_tmr_req->ref_task_tag = task;
304 
305 	/*
306 	 * Locate the underlying TCM struct se_lun
307 	 */
308 	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
309 		ret = TMR_LUN_DOES_NOT_EXIST;
310 		goto release;
311 	}
312 	/*
313 	 * Queue the TMR to TCM Core and sleep waiting for
314 	 * tcm_loop_queue_tm_rsp() to wake us up.
315 	 */
316 	transport_generic_handle_tmr(se_cmd);
317 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
318 	/*
319 	 * The TMR LUN_RESET has completed, check the response status and
320 	 * then release allocations.
321 	 */
322 	ret = se_cmd->se_tmr_req->response;
323 release:
324 	if (se_cmd)
325 		transport_generic_free_cmd(se_cmd, 1);
326 	else
327 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
328 	kfree(tl_tmr);
329 	return ret;
330 }
331 
332 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
333 {
334 	struct tcm_loop_hba *tl_hba;
335 	struct tcm_loop_nexus *tl_nexus;
336 	struct tcm_loop_tpg *tl_tpg;
337 	int ret = FAILED;
338 
339 	/*
340 	 * Locate the tcm_loop_hba_t pointer
341 	 */
342 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
343 	/*
344 	 * Locate the tl_nexus and se_sess pointers
345 	 */
346 	tl_nexus = tl_hba->tl_nexus;
347 	if (!tl_nexus) {
348 		pr_err("Unable to perform device reset without"
349 				" active I_T Nexus\n");
350 		return FAILED;
351 	}
352 
353 	/*
354 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
355 	 */
356 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
357 	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
358 				 sc->tag, TMR_ABORT_TASK);
359 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
360 }
361 
362 /*
363  * Called from SCSI EH process context to issue a LUN_RESET TMR
364  * to struct scsi_device
365  */
366 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
367 {
368 	struct tcm_loop_hba *tl_hba;
369 	struct tcm_loop_nexus *tl_nexus;
370 	struct tcm_loop_tpg *tl_tpg;
371 	int ret = FAILED;
372 
373 	/*
374 	 * Locate the tcm_loop_hba_t pointer
375 	 */
376 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
377 	/*
378 	 * Locate the tl_nexus and se_sess pointers
379 	 */
380 	tl_nexus = tl_hba->tl_nexus;
381 	if (!tl_nexus) {
382 		pr_err("Unable to perform device reset without"
383 				" active I_T Nexus\n");
384 		return FAILED;
385 	}
386 	/*
387 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
388 	 */
389 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
390 	ret = tcm_loop_issue_tmr(tl_tpg, tl_nexus, sc->device->lun,
391 				 0, TMR_LUN_RESET);
392 	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
393 }
394 
395 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
396 {
397 	struct tcm_loop_hba *tl_hba;
398 	struct tcm_loop_tpg *tl_tpg;
399 
400 	/*
401 	 * Locate the tcm_loop_hba_t pointer
402 	 */
403 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
404 	if (!tl_hba) {
405 		pr_err("Unable to perform device reset without"
406 				" active I_T Nexus\n");
407 		return FAILED;
408 	}
409 	/*
410 	 * Locate the tl_tpg pointer from TargetID in sc->device->id
411 	 */
412 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
413 	if (tl_tpg) {
414 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
415 		return SUCCESS;
416 	}
417 	return FAILED;
418 }
419 
420 static int tcm_loop_slave_alloc(struct scsi_device *sd)
421 {
422 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
423 	return 0;
424 }
425 
426 static int tcm_loop_slave_configure(struct scsi_device *sd)
427 {
428 	if (sd->tagged_supported) {
429 		scsi_activate_tcq(sd, sd->queue_depth);
430 		scsi_adjust_queue_depth(sd, MSG_SIMPLE_TAG,
431 					sd->host->cmd_per_lun);
432 	} else {
433 		scsi_adjust_queue_depth(sd, 0,
434 					sd->host->cmd_per_lun);
435 	}
436 
437 	return 0;
438 }
439 
440 static struct scsi_host_template tcm_loop_driver_template = {
441 	.show_info		= tcm_loop_show_info,
442 	.proc_name		= "tcm_loopback",
443 	.name			= "TCM_Loopback",
444 	.queuecommand		= tcm_loop_queuecommand,
445 	.change_queue_depth	= tcm_loop_change_queue_depth,
446 	.change_queue_type	= tcm_loop_change_queue_type,
447 	.eh_abort_handler = tcm_loop_abort_task,
448 	.eh_device_reset_handler = tcm_loop_device_reset,
449 	.eh_target_reset_handler = tcm_loop_target_reset,
450 	.can_queue		= 1024,
451 	.this_id		= -1,
452 	.sg_tablesize		= 256,
453 	.cmd_per_lun		= 1024,
454 	.max_sectors		= 0xFFFF,
455 	.use_clustering		= DISABLE_CLUSTERING,
456 	.slave_alloc		= tcm_loop_slave_alloc,
457 	.slave_configure	= tcm_loop_slave_configure,
458 	.module			= THIS_MODULE,
459 };
460 
461 static int tcm_loop_driver_probe(struct device *dev)
462 {
463 	struct tcm_loop_hba *tl_hba;
464 	struct Scsi_Host *sh;
465 	int error;
466 
467 	tl_hba = to_tcm_loop_hba(dev);
468 
469 	sh = scsi_host_alloc(&tcm_loop_driver_template,
470 			sizeof(struct tcm_loop_hba));
471 	if (!sh) {
472 		pr_err("Unable to allocate struct scsi_host\n");
473 		return -ENODEV;
474 	}
475 	tl_hba->sh = sh;
476 
477 	/*
478 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
479 	 */
480 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
481 	/*
482 	 * Setup single ID, Channel and LUN for now..
483 	 */
484 	sh->max_id = 2;
485 	sh->max_lun = 0;
486 	sh->max_channel = 0;
487 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
488 
489 	error = scsi_add_host(sh, &tl_hba->dev);
490 	if (error) {
491 		pr_err("%s: scsi_add_host failed\n", __func__);
492 		scsi_host_put(sh);
493 		return -ENODEV;
494 	}
495 	return 0;
496 }
497 
498 static int tcm_loop_driver_remove(struct device *dev)
499 {
500 	struct tcm_loop_hba *tl_hba;
501 	struct Scsi_Host *sh;
502 
503 	tl_hba = to_tcm_loop_hba(dev);
504 	sh = tl_hba->sh;
505 
506 	scsi_remove_host(sh);
507 	scsi_host_put(sh);
508 	return 0;
509 }
510 
511 static void tcm_loop_release_adapter(struct device *dev)
512 {
513 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
514 
515 	kfree(tl_hba);
516 }
517 
518 /*
519  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
520  */
521 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
522 {
523 	int ret;
524 
525 	tl_hba->dev.bus = &tcm_loop_lld_bus;
526 	tl_hba->dev.parent = tcm_loop_primary;
527 	tl_hba->dev.release = &tcm_loop_release_adapter;
528 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
529 
530 	ret = device_register(&tl_hba->dev);
531 	if (ret) {
532 		pr_err("device_register() failed for"
533 				" tl_hba->dev: %d\n", ret);
534 		return -ENODEV;
535 	}
536 
537 	return 0;
538 }
539 
540 /*
541  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
542  * tcm_loop SCSI bus.
543  */
544 static int tcm_loop_alloc_core_bus(void)
545 {
546 	int ret;
547 
548 	tcm_loop_primary = root_device_register("tcm_loop_0");
549 	if (IS_ERR(tcm_loop_primary)) {
550 		pr_err("Unable to allocate tcm_loop_primary\n");
551 		return PTR_ERR(tcm_loop_primary);
552 	}
553 
554 	ret = bus_register(&tcm_loop_lld_bus);
555 	if (ret) {
556 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
557 		goto dev_unreg;
558 	}
559 
560 	ret = driver_register(&tcm_loop_driverfs);
561 	if (ret) {
562 		pr_err("driver_register() failed for"
563 				"tcm_loop_driverfs\n");
564 		goto bus_unreg;
565 	}
566 
567 	pr_debug("Initialized TCM Loop Core Bus\n");
568 	return ret;
569 
570 bus_unreg:
571 	bus_unregister(&tcm_loop_lld_bus);
572 dev_unreg:
573 	root_device_unregister(tcm_loop_primary);
574 	return ret;
575 }
576 
577 static void tcm_loop_release_core_bus(void)
578 {
579 	driver_unregister(&tcm_loop_driverfs);
580 	bus_unregister(&tcm_loop_lld_bus);
581 	root_device_unregister(tcm_loop_primary);
582 
583 	pr_debug("Releasing TCM Loop Core BUS\n");
584 }
585 
586 static char *tcm_loop_get_fabric_name(void)
587 {
588 	return "loopback";
589 }
590 
591 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
592 {
593 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
594 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
595 	/*
596 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
597 	 * time based on the protocol dependent prefix of the passed configfs group.
598 	 *
599 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
600 	 * ProtocolID using target_core_fabric_lib.c symbols.
601 	 */
602 	switch (tl_hba->tl_proto_id) {
603 	case SCSI_PROTOCOL_SAS:
604 		return sas_get_fabric_proto_ident(se_tpg);
605 	case SCSI_PROTOCOL_FCP:
606 		return fc_get_fabric_proto_ident(se_tpg);
607 	case SCSI_PROTOCOL_ISCSI:
608 		return iscsi_get_fabric_proto_ident(se_tpg);
609 	default:
610 		pr_err("Unknown tl_proto_id: 0x%02x, using"
611 			" SAS emulation\n", tl_hba->tl_proto_id);
612 		break;
613 	}
614 
615 	return sas_get_fabric_proto_ident(se_tpg);
616 }
617 
618 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
619 {
620 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
621 	/*
622 	 * Return the passed NAA identifier for the SAS Target Port
623 	 */
624 	return &tl_tpg->tl_hba->tl_wwn_address[0];
625 }
626 
627 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
628 {
629 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
630 	/*
631 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
632 	 * to represent the SCSI Target Port.
633 	 */
634 	return tl_tpg->tl_tpgt;
635 }
636 
637 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
638 {
639 	return 1;
640 }
641 
642 static u32 tcm_loop_get_pr_transport_id(
643 	struct se_portal_group *se_tpg,
644 	struct se_node_acl *se_nacl,
645 	struct t10_pr_registration *pr_reg,
646 	int *format_code,
647 	unsigned char *buf)
648 {
649 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
650 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
651 
652 	switch (tl_hba->tl_proto_id) {
653 	case SCSI_PROTOCOL_SAS:
654 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
655 					format_code, buf);
656 	case SCSI_PROTOCOL_FCP:
657 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
658 					format_code, buf);
659 	case SCSI_PROTOCOL_ISCSI:
660 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
661 					format_code, buf);
662 	default:
663 		pr_err("Unknown tl_proto_id: 0x%02x, using"
664 			" SAS emulation\n", tl_hba->tl_proto_id);
665 		break;
666 	}
667 
668 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
669 			format_code, buf);
670 }
671 
672 static u32 tcm_loop_get_pr_transport_id_len(
673 	struct se_portal_group *se_tpg,
674 	struct se_node_acl *se_nacl,
675 	struct t10_pr_registration *pr_reg,
676 	int *format_code)
677 {
678 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
679 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
680 
681 	switch (tl_hba->tl_proto_id) {
682 	case SCSI_PROTOCOL_SAS:
683 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
684 					format_code);
685 	case SCSI_PROTOCOL_FCP:
686 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
687 					format_code);
688 	case SCSI_PROTOCOL_ISCSI:
689 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
690 					format_code);
691 	default:
692 		pr_err("Unknown tl_proto_id: 0x%02x, using"
693 			" SAS emulation\n", tl_hba->tl_proto_id);
694 		break;
695 	}
696 
697 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
698 			format_code);
699 }
700 
701 /*
702  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
703  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
704  */
705 static char *tcm_loop_parse_pr_out_transport_id(
706 	struct se_portal_group *se_tpg,
707 	const char *buf,
708 	u32 *out_tid_len,
709 	char **port_nexus_ptr)
710 {
711 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
712 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
713 
714 	switch (tl_hba->tl_proto_id) {
715 	case SCSI_PROTOCOL_SAS:
716 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
717 					port_nexus_ptr);
718 	case SCSI_PROTOCOL_FCP:
719 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
720 					port_nexus_ptr);
721 	case SCSI_PROTOCOL_ISCSI:
722 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
723 					port_nexus_ptr);
724 	default:
725 		pr_err("Unknown tl_proto_id: 0x%02x, using"
726 			" SAS emulation\n", tl_hba->tl_proto_id);
727 		break;
728 	}
729 
730 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
731 			port_nexus_ptr);
732 }
733 
734 /*
735  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
736  * based upon the incoming fabric dependent SCSI Initiator Port
737  */
738 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
739 {
740 	return 1;
741 }
742 
743 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
744 {
745 	return 0;
746 }
747 
748 /*
749  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
750  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
751  */
752 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
753 {
754 	return 0;
755 }
756 
757 /*
758  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
759  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
760  * It has been added here as a nop for target_fabric_tf_ops_check()
761  */
762 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
763 {
764 	return 0;
765 }
766 
767 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
768 	struct se_portal_group *se_tpg)
769 {
770 	struct tcm_loop_nacl *tl_nacl;
771 
772 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
773 	if (!tl_nacl) {
774 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
775 		return NULL;
776 	}
777 
778 	return &tl_nacl->se_node_acl;
779 }
780 
781 static void tcm_loop_tpg_release_fabric_acl(
782 	struct se_portal_group *se_tpg,
783 	struct se_node_acl *se_nacl)
784 {
785 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
786 				struct tcm_loop_nacl, se_node_acl);
787 
788 	kfree(tl_nacl);
789 }
790 
791 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
792 {
793 	return 1;
794 }
795 
796 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
797 {
798 	return 1;
799 }
800 
801 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
802 {
803 	return;
804 }
805 
806 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
807 {
808 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
809 			struct tcm_loop_cmd, tl_se_cmd);
810 
811 	return tl_cmd->sc_cmd_tag;
812 }
813 
814 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
815 {
816 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
817 			struct tcm_loop_cmd, tl_se_cmd);
818 
819 	return tl_cmd->sc_cmd_state;
820 }
821 
822 static int tcm_loop_shutdown_session(struct se_session *se_sess)
823 {
824 	return 0;
825 }
826 
827 static void tcm_loop_close_session(struct se_session *se_sess)
828 {
829 	return;
830 };
831 
832 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
833 {
834 	/*
835 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
836 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
837 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
838 	 * format with transport_generic_map_mem_to_cmd().
839 	 *
840 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
841 	 * object execution queue.
842 	 */
843 	target_execute_cmd(se_cmd);
844 	return 0;
845 }
846 
847 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
848 {
849 	return 0;
850 }
851 
852 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
853 {
854 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
855 				struct tcm_loop_cmd, tl_se_cmd);
856 	struct scsi_cmnd *sc = tl_cmd->sc;
857 
858 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
859 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
860 
861 	sc->result = SAM_STAT_GOOD;
862 	set_host_byte(sc, DID_OK);
863 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
864 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
865 		scsi_set_resid(sc, se_cmd->residual_count);
866 	sc->scsi_done(sc);
867 	return 0;
868 }
869 
870 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
871 {
872 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
873 				struct tcm_loop_cmd, tl_se_cmd);
874 	struct scsi_cmnd *sc = tl_cmd->sc;
875 
876 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
877 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
878 
879 	if (se_cmd->sense_buffer &&
880 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
881 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
882 
883 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
884 				SCSI_SENSE_BUFFERSIZE);
885 		sc->result = SAM_STAT_CHECK_CONDITION;
886 		set_driver_byte(sc, DRIVER_SENSE);
887 	} else
888 		sc->result = se_cmd->scsi_status;
889 
890 	set_host_byte(sc, DID_OK);
891 	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
892 	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
893 		scsi_set_resid(sc, se_cmd->residual_count);
894 	sc->scsi_done(sc);
895 	return 0;
896 }
897 
898 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
899 {
900 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
901 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
902 	/*
903 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
904 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
905 	 */
906 	atomic_set(&tl_tmr->tmr_complete, 1);
907 	wake_up(&tl_tmr->tl_tmr_wait);
908 }
909 
910 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
911 {
912 	switch (tl_hba->tl_proto_id) {
913 	case SCSI_PROTOCOL_SAS:
914 		return "SAS";
915 	case SCSI_PROTOCOL_FCP:
916 		return "FCP";
917 	case SCSI_PROTOCOL_ISCSI:
918 		return "iSCSI";
919 	default:
920 		break;
921 	}
922 
923 	return "Unknown";
924 }
925 
926 /* Start items for tcm_loop_port_cit */
927 
928 static int tcm_loop_port_link(
929 	struct se_portal_group *se_tpg,
930 	struct se_lun *lun)
931 {
932 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
933 				struct tcm_loop_tpg, tl_se_tpg);
934 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
935 
936 	atomic_inc(&tl_tpg->tl_tpg_port_count);
937 	smp_mb__after_atomic_inc();
938 	/*
939 	 * Add Linux/SCSI struct scsi_device by HCTL
940 	 */
941 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
942 
943 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
944 	return 0;
945 }
946 
947 static void tcm_loop_port_unlink(
948 	struct se_portal_group *se_tpg,
949 	struct se_lun *se_lun)
950 {
951 	struct scsi_device *sd;
952 	struct tcm_loop_hba *tl_hba;
953 	struct tcm_loop_tpg *tl_tpg;
954 
955 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
956 	tl_hba = tl_tpg->tl_hba;
957 
958 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
959 				se_lun->unpacked_lun);
960 	if (!sd) {
961 		pr_err("Unable to locate struct scsi_device for %d:%d:"
962 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
963 		return;
964 	}
965 	/*
966 	 * Remove Linux/SCSI struct scsi_device by HCTL
967 	 */
968 	scsi_remove_device(sd);
969 	scsi_device_put(sd);
970 
971 	atomic_dec(&tl_tpg->tl_tpg_port_count);
972 	smp_mb__after_atomic_dec();
973 
974 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
975 }
976 
977 /* End items for tcm_loop_port_cit */
978 
979 /* Start items for tcm_loop_nexus_cit */
980 
981 static int tcm_loop_make_nexus(
982 	struct tcm_loop_tpg *tl_tpg,
983 	const char *name)
984 {
985 	struct se_portal_group *se_tpg;
986 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
987 	struct tcm_loop_nexus *tl_nexus;
988 	int ret = -ENOMEM;
989 
990 	if (tl_tpg->tl_hba->tl_nexus) {
991 		pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
992 		return -EEXIST;
993 	}
994 	se_tpg = &tl_tpg->tl_se_tpg;
995 
996 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
997 	if (!tl_nexus) {
998 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
999 		return -ENOMEM;
1000 	}
1001 	/*
1002 	 * Initialize the struct se_session pointer
1003 	 */
1004 	tl_nexus->se_sess = transport_init_session();
1005 	if (IS_ERR(tl_nexus->se_sess)) {
1006 		ret = PTR_ERR(tl_nexus->se_sess);
1007 		goto out;
1008 	}
1009 	/*
1010 	 * Since we are running in 'demo mode' this call with generate a
1011 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1012 	 * Initiator port name of the passed configfs group 'name'.
1013 	 */
1014 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1015 				se_tpg, (unsigned char *)name);
1016 	if (!tl_nexus->se_sess->se_node_acl) {
1017 		transport_free_session(tl_nexus->se_sess);
1018 		goto out;
1019 	}
1020 	/*
1021 	 * Now, register the SAS I_T Nexus as active with the call to
1022 	 * transport_register_session()
1023 	 */
1024 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1025 			tl_nexus->se_sess, tl_nexus);
1026 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
1027 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1028 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1029 		name);
1030 	return 0;
1031 
1032 out:
1033 	kfree(tl_nexus);
1034 	return ret;
1035 }
1036 
1037 static int tcm_loop_drop_nexus(
1038 	struct tcm_loop_tpg *tpg)
1039 {
1040 	struct se_session *se_sess;
1041 	struct tcm_loop_nexus *tl_nexus;
1042 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1043 
1044 	if (!tl_hba)
1045 		return -ENODEV;
1046 
1047 	tl_nexus = tl_hba->tl_nexus;
1048 	if (!tl_nexus)
1049 		return -ENODEV;
1050 
1051 	se_sess = tl_nexus->se_sess;
1052 	if (!se_sess)
1053 		return -ENODEV;
1054 
1055 	if (atomic_read(&tpg->tl_tpg_port_count)) {
1056 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
1057 			" active TPG port count: %d\n",
1058 			atomic_read(&tpg->tl_tpg_port_count));
1059 		return -EPERM;
1060 	}
1061 
1062 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1063 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1064 		tl_nexus->se_sess->se_node_acl->initiatorname);
1065 	/*
1066 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
1067 	 */
1068 	transport_deregister_session(tl_nexus->se_sess);
1069 	tpg->tl_hba->tl_nexus = NULL;
1070 	kfree(tl_nexus);
1071 	return 0;
1072 }
1073 
1074 /* End items for tcm_loop_nexus_cit */
1075 
1076 static ssize_t tcm_loop_tpg_show_nexus(
1077 	struct se_portal_group *se_tpg,
1078 	char *page)
1079 {
1080 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1081 			struct tcm_loop_tpg, tl_se_tpg);
1082 	struct tcm_loop_nexus *tl_nexus;
1083 	ssize_t ret;
1084 
1085 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
1086 	if (!tl_nexus)
1087 		return -ENODEV;
1088 
1089 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1090 		tl_nexus->se_sess->se_node_acl->initiatorname);
1091 
1092 	return ret;
1093 }
1094 
1095 static ssize_t tcm_loop_tpg_store_nexus(
1096 	struct se_portal_group *se_tpg,
1097 	const char *page,
1098 	size_t count)
1099 {
1100 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1101 			struct tcm_loop_tpg, tl_se_tpg);
1102 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1103 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1104 	int ret;
1105 	/*
1106 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1107 	 */
1108 	if (!strncmp(page, "NULL", 4)) {
1109 		ret = tcm_loop_drop_nexus(tl_tpg);
1110 		return (!ret) ? count : ret;
1111 	}
1112 	/*
1113 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1114 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1115 	 * tcm_loop_make_nexus()
1116 	 */
1117 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1118 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1119 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1120 		return -EINVAL;
1121 	}
1122 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1123 
1124 	ptr = strstr(i_port, "naa.");
1125 	if (ptr) {
1126 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1127 			pr_err("Passed SAS Initiator Port %s does not"
1128 				" match target port protoid: %s\n", i_port,
1129 				tcm_loop_dump_proto_id(tl_hba));
1130 			return -EINVAL;
1131 		}
1132 		port_ptr = &i_port[0];
1133 		goto check_newline;
1134 	}
1135 	ptr = strstr(i_port, "fc.");
1136 	if (ptr) {
1137 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1138 			pr_err("Passed FCP Initiator Port %s does not"
1139 				" match target port protoid: %s\n", i_port,
1140 				tcm_loop_dump_proto_id(tl_hba));
1141 			return -EINVAL;
1142 		}
1143 		port_ptr = &i_port[3]; /* Skip over "fc." */
1144 		goto check_newline;
1145 	}
1146 	ptr = strstr(i_port, "iqn.");
1147 	if (ptr) {
1148 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1149 			pr_err("Passed iSCSI Initiator Port %s does not"
1150 				" match target port protoid: %s\n", i_port,
1151 				tcm_loop_dump_proto_id(tl_hba));
1152 			return -EINVAL;
1153 		}
1154 		port_ptr = &i_port[0];
1155 		goto check_newline;
1156 	}
1157 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1158 			" %s\n", i_port);
1159 	return -EINVAL;
1160 	/*
1161 	 * Clear any trailing newline for the NAA WWN
1162 	 */
1163 check_newline:
1164 	if (i_port[strlen(i_port)-1] == '\n')
1165 		i_port[strlen(i_port)-1] = '\0';
1166 
1167 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1168 	if (ret < 0)
1169 		return ret;
1170 
1171 	return count;
1172 }
1173 
1174 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1175 
1176 static ssize_t tcm_loop_tpg_show_transport_status(
1177 	struct se_portal_group *se_tpg,
1178 	char *page)
1179 {
1180 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1181 			struct tcm_loop_tpg, tl_se_tpg);
1182 	const char *status = NULL;
1183 	ssize_t ret = -EINVAL;
1184 
1185 	switch (tl_tpg->tl_transport_status) {
1186 	case TCM_TRANSPORT_ONLINE:
1187 		status = "online";
1188 		break;
1189 	case TCM_TRANSPORT_OFFLINE:
1190 		status = "offline";
1191 		break;
1192 	default:
1193 		break;
1194 	}
1195 
1196 	if (status)
1197 		ret = snprintf(page, PAGE_SIZE, "%s\n", status);
1198 
1199 	return ret;
1200 }
1201 
1202 static ssize_t tcm_loop_tpg_store_transport_status(
1203 	struct se_portal_group *se_tpg,
1204 	const char *page,
1205 	size_t count)
1206 {
1207 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1208 			struct tcm_loop_tpg, tl_se_tpg);
1209 
1210 	if (!strncmp(page, "online", 6)) {
1211 		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
1212 		return count;
1213 	}
1214 	if (!strncmp(page, "offline", 7)) {
1215 		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
1216 		return count;
1217 	}
1218 	return -EINVAL;
1219 }
1220 
1221 TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
1222 
1223 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1224 	&tcm_loop_tpg_nexus.attr,
1225 	&tcm_loop_tpg_transport_status.attr,
1226 	NULL,
1227 };
1228 
1229 /* Start items for tcm_loop_naa_cit */
1230 
1231 struct se_portal_group *tcm_loop_make_naa_tpg(
1232 	struct se_wwn *wwn,
1233 	struct config_group *group,
1234 	const char *name)
1235 {
1236 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1237 			struct tcm_loop_hba, tl_hba_wwn);
1238 	struct tcm_loop_tpg *tl_tpg;
1239 	char *tpgt_str, *end_ptr;
1240 	int ret;
1241 	unsigned short int tpgt;
1242 
1243 	tpgt_str = strstr(name, "tpgt_");
1244 	if (!tpgt_str) {
1245 		pr_err("Unable to locate \"tpgt_#\" directory"
1246 				" group\n");
1247 		return ERR_PTR(-EINVAL);
1248 	}
1249 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1250 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1251 
1252 	if (tpgt >= TL_TPGS_PER_HBA) {
1253 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1254 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1255 		return ERR_PTR(-EINVAL);
1256 	}
1257 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1258 	tl_tpg->tl_hba = tl_hba;
1259 	tl_tpg->tl_tpgt = tpgt;
1260 	/*
1261 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1262 	 */
1263 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1264 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1265 			TRANSPORT_TPG_TYPE_NORMAL);
1266 	if (ret < 0)
1267 		return ERR_PTR(-ENOMEM);
1268 
1269 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1270 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1271 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1272 
1273 	return &tl_tpg->tl_se_tpg;
1274 }
1275 
1276 void tcm_loop_drop_naa_tpg(
1277 	struct se_portal_group *se_tpg)
1278 {
1279 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1280 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1281 				struct tcm_loop_tpg, tl_se_tpg);
1282 	struct tcm_loop_hba *tl_hba;
1283 	unsigned short tpgt;
1284 
1285 	tl_hba = tl_tpg->tl_hba;
1286 	tpgt = tl_tpg->tl_tpgt;
1287 	/*
1288 	 * Release the I_T Nexus for the Virtual SAS link if present
1289 	 */
1290 	tcm_loop_drop_nexus(tl_tpg);
1291 	/*
1292 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1293 	 */
1294 	core_tpg_deregister(se_tpg);
1295 
1296 	tl_tpg->tl_hba = NULL;
1297 	tl_tpg->tl_tpgt = 0;
1298 
1299 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1300 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1301 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1302 }
1303 
1304 /* End items for tcm_loop_naa_cit */
1305 
1306 /* Start items for tcm_loop_cit */
1307 
1308 struct se_wwn *tcm_loop_make_scsi_hba(
1309 	struct target_fabric_configfs *tf,
1310 	struct config_group *group,
1311 	const char *name)
1312 {
1313 	struct tcm_loop_hba *tl_hba;
1314 	struct Scsi_Host *sh;
1315 	char *ptr;
1316 	int ret, off = 0;
1317 
1318 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1319 	if (!tl_hba) {
1320 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1321 		return ERR_PTR(-ENOMEM);
1322 	}
1323 	/*
1324 	 * Determine the emulated Protocol Identifier and Target Port Name
1325 	 * based on the incoming configfs directory name.
1326 	 */
1327 	ptr = strstr(name, "naa.");
1328 	if (ptr) {
1329 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1330 		goto check_len;
1331 	}
1332 	ptr = strstr(name, "fc.");
1333 	if (ptr) {
1334 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1335 		off = 3; /* Skip over "fc." */
1336 		goto check_len;
1337 	}
1338 	ptr = strstr(name, "iqn.");
1339 	if (!ptr) {
1340 		pr_err("Unable to locate prefix for emulated Target "
1341 				"Port: %s\n", name);
1342 		ret = -EINVAL;
1343 		goto out;
1344 	}
1345 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1346 
1347 check_len:
1348 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1349 		pr_err("Emulated NAA %s Address: %s, exceeds"
1350 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1351 			TL_WWN_ADDR_LEN);
1352 		ret = -EINVAL;
1353 		goto out;
1354 	}
1355 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1356 
1357 	/*
1358 	 * Call device_register(tl_hba->dev) to register the emulated
1359 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1360 	 * device_register() callbacks in tcm_loop_driver_probe()
1361 	 */
1362 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1363 	if (ret)
1364 		goto out;
1365 
1366 	sh = tl_hba->sh;
1367 	tcm_loop_hba_no_cnt++;
1368 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1369 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1370 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1371 
1372 	return &tl_hba->tl_hba_wwn;
1373 out:
1374 	kfree(tl_hba);
1375 	return ERR_PTR(ret);
1376 }
1377 
1378 void tcm_loop_drop_scsi_hba(
1379 	struct se_wwn *wwn)
1380 {
1381 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1382 				struct tcm_loop_hba, tl_hba_wwn);
1383 
1384 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1385 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1386 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1387 	/*
1388 	 * Call device_unregister() on the original tl_hba->dev.
1389 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1390 	 * release *tl_hba;
1391 	 */
1392 	device_unregister(&tl_hba->dev);
1393 }
1394 
1395 /* Start items for tcm_loop_cit */
1396 static ssize_t tcm_loop_wwn_show_attr_version(
1397 	struct target_fabric_configfs *tf,
1398 	char *page)
1399 {
1400 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1401 }
1402 
1403 TF_WWN_ATTR_RO(tcm_loop, version);
1404 
1405 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1406 	&tcm_loop_wwn_version.attr,
1407 	NULL,
1408 };
1409 
1410 /* End items for tcm_loop_cit */
1411 
1412 static int tcm_loop_register_configfs(void)
1413 {
1414 	struct target_fabric_configfs *fabric;
1415 	int ret;
1416 	/*
1417 	 * Set the TCM Loop HBA counter to zero
1418 	 */
1419 	tcm_loop_hba_no_cnt = 0;
1420 	/*
1421 	 * Register the top level struct config_item_type with TCM core
1422 	 */
1423 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1424 	if (IS_ERR(fabric)) {
1425 		pr_err("tcm_loop_register_configfs() failed!\n");
1426 		return PTR_ERR(fabric);
1427 	}
1428 	/*
1429 	 * Setup the fabric API of function pointers used by target_core_mod
1430 	 */
1431 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1432 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1433 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1434 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1435 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1436 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1437 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1438 					&tcm_loop_get_pr_transport_id_len;
1439 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1440 					&tcm_loop_parse_pr_out_transport_id;
1441 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1442 	fabric->tf_ops.tpg_check_demo_mode_cache =
1443 					&tcm_loop_check_demo_mode_cache;
1444 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1445 					&tcm_loop_check_demo_mode_write_protect;
1446 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1447 					&tcm_loop_check_prod_mode_write_protect;
1448 	/*
1449 	 * The TCM loopback fabric module runs in demo-mode to a local
1450 	 * virtual SCSI device, so fabric dependent initator ACLs are
1451 	 * not required.
1452 	 */
1453 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1454 	fabric->tf_ops.tpg_release_fabric_acl =
1455 					&tcm_loop_tpg_release_fabric_acl;
1456 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1457 	/*
1458 	 * Used for setting up remaining TCM resources in process context
1459 	 */
1460 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1461 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1462 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1463 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1464 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1465 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1466 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1467 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1468 	/*
1469 	 * Not used for TCM loopback
1470 	 */
1471 	fabric->tf_ops.set_default_node_attributes =
1472 					&tcm_loop_set_default_node_attributes;
1473 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1474 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1475 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1476 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1477 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1478 
1479 	/*
1480 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1481 	 */
1482 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1483 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1484 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1485 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1486 	/*
1487 	 * fabric_post_link() and fabric_pre_unlink() are used for
1488 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1489 	 */
1490 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1491 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1492 	fabric->tf_ops.fabric_make_np = NULL;
1493 	fabric->tf_ops.fabric_drop_np = NULL;
1494 	/*
1495 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1496 	 */
1497 	fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1498 	fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1499 	fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
1500 	fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
1501 	fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
1502 	/*
1503 	 * Once fabric->tf_ops has been setup, now register the fabric for
1504 	 * use within TCM
1505 	 */
1506 	ret = target_fabric_configfs_register(fabric);
1507 	if (ret < 0) {
1508 		pr_err("target_fabric_configfs_register() for"
1509 				" TCM_Loop failed!\n");
1510 		target_fabric_configfs_free(fabric);
1511 		return -1;
1512 	}
1513 	/*
1514 	 * Setup our local pointer to *fabric.
1515 	 */
1516 	tcm_loop_fabric_configfs = fabric;
1517 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1518 			" tcm_loop_fabric_configfs\n");
1519 	return 0;
1520 }
1521 
1522 static void tcm_loop_deregister_configfs(void)
1523 {
1524 	if (!tcm_loop_fabric_configfs)
1525 		return;
1526 
1527 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1528 	tcm_loop_fabric_configfs = NULL;
1529 	pr_debug("TCM_LOOP[0] - Cleared"
1530 				" tcm_loop_fabric_configfs\n");
1531 }
1532 
1533 static int __init tcm_loop_fabric_init(void)
1534 {
1535 	int ret = -ENOMEM;
1536 
1537 	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
1538 	if (!tcm_loop_workqueue)
1539 		goto out;
1540 
1541 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1542 				sizeof(struct tcm_loop_cmd),
1543 				__alignof__(struct tcm_loop_cmd),
1544 				0, NULL);
1545 	if (!tcm_loop_cmd_cache) {
1546 		pr_debug("kmem_cache_create() for"
1547 			" tcm_loop_cmd_cache failed\n");
1548 		goto out_destroy_workqueue;
1549 	}
1550 
1551 	ret = tcm_loop_alloc_core_bus();
1552 	if (ret)
1553 		goto out_destroy_cache;
1554 
1555 	ret = tcm_loop_register_configfs();
1556 	if (ret)
1557 		goto out_release_core_bus;
1558 
1559 	return 0;
1560 
1561 out_release_core_bus:
1562 	tcm_loop_release_core_bus();
1563 out_destroy_cache:
1564 	kmem_cache_destroy(tcm_loop_cmd_cache);
1565 out_destroy_workqueue:
1566 	destroy_workqueue(tcm_loop_workqueue);
1567 out:
1568 	return ret;
1569 }
1570 
1571 static void __exit tcm_loop_fabric_exit(void)
1572 {
1573 	tcm_loop_deregister_configfs();
1574 	tcm_loop_release_core_bus();
1575 	kmem_cache_destroy(tcm_loop_cmd_cache);
1576 	destroy_workqueue(tcm_loop_workqueue);
1577 }
1578 
1579 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1580 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1581 MODULE_LICENSE("GPL");
1582 module_init(tcm_loop_fabric_init);
1583 module_exit(tcm_loop_fabric_exit);
1584