xref: /linux/drivers/target/loopback/tcm_loop.c (revision a429638cac1e5c656818a45aaff78df7b743004e)
1 /*******************************************************************************
2  *
3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
4  * for emulated SAS initiator ports
5  *
6  * © Copyright 2011 RisingTide Systems LLC.
7  *
8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
9  *
10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  ****************************************************************************/
22 
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/configfs.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_cmnd.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_transport.h>
37 #include <target/target_core_fabric_ops.h>
38 #include <target/target_core_fabric_configfs.h>
39 #include <target/target_core_fabric_lib.h>
40 #include <target/target_core_configfs.h>
41 #include <target/target_core_device.h>
42 #include <target/target_core_tpg.h>
43 #include <target/target_core_tmr.h>
44 
45 #include "tcm_loop.h"
46 
47 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
48 
49 /* Local pointer to allocated TCM configfs fabric module */
50 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
51 
52 static struct kmem_cache *tcm_loop_cmd_cache;
53 
54 static int tcm_loop_hba_no_cnt;
55 
56 /*
57  * Allocate a tcm_loop cmd descriptor from target_core_mod code
58  *
59  * Can be called from interrupt context in tcm_loop_queuecommand() below
60  */
61 static struct se_cmd *tcm_loop_allocate_core_cmd(
62 	struct tcm_loop_hba *tl_hba,
63 	struct se_portal_group *se_tpg,
64 	struct scsi_cmnd *sc)
65 {
66 	struct se_cmd *se_cmd;
67 	struct se_session *se_sess;
68 	struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
69 	struct tcm_loop_cmd *tl_cmd;
70 	int sam_task_attr;
71 
72 	if (!tl_nexus) {
73 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
74 				" does not exist\n");
75 		set_host_byte(sc, DID_ERROR);
76 		return NULL;
77 	}
78 	se_sess = tl_nexus->se_sess;
79 
80 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
81 	if (!tl_cmd) {
82 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
83 		set_host_byte(sc, DID_ERROR);
84 		return NULL;
85 	}
86 	se_cmd = &tl_cmd->tl_se_cmd;
87 	/*
88 	 * Save the pointer to struct scsi_cmnd *sc
89 	 */
90 	tl_cmd->sc = sc;
91 	/*
92 	 * Locate the SAM Task Attr from struct scsi_cmnd *
93 	 */
94 	if (sc->device->tagged_supported) {
95 		switch (sc->tag) {
96 		case HEAD_OF_QUEUE_TAG:
97 			sam_task_attr = MSG_HEAD_TAG;
98 			break;
99 		case ORDERED_QUEUE_TAG:
100 			sam_task_attr = MSG_ORDERED_TAG;
101 			break;
102 		default:
103 			sam_task_attr = MSG_SIMPLE_TAG;
104 			break;
105 		}
106 	} else
107 		sam_task_attr = MSG_SIMPLE_TAG;
108 
109 	/*
110 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
111 	 */
112 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
113 			scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
114 			&tl_cmd->tl_sense_buf[0]);
115 
116 	if (scsi_bidi_cmnd(sc))
117 		se_cmd->se_cmd_flags |= SCF_BIDI;
118 
119 	/*
120 	 * Locate the struct se_lun pointer and attach it to struct se_cmd
121 	 */
122 	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
123 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
124 		set_host_byte(sc, DID_NO_CONNECT);
125 		return NULL;
126 	}
127 
128 	return se_cmd;
129 }
130 
131 /*
132  * Called by struct target_core_fabric_ops->new_cmd_map()
133  *
134  * Always called in process context.  A non zero return value
135  * here will signal to handle an exception based on the return code.
136  */
137 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
138 {
139 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
140 				struct tcm_loop_cmd, tl_se_cmd);
141 	struct scsi_cmnd *sc = tl_cmd->sc;
142 	struct scatterlist *sgl_bidi = NULL;
143 	u32 sgl_bidi_count = 0;
144 	int ret;
145 	/*
146 	 * Allocate the necessary tasks to complete the received CDB+data
147 	 */
148 	ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
149 	if (ret != 0)
150 		return ret;
151 	/*
152 	 * For BIDI commands, pass in the extra READ buffer
153 	 * to transport_generic_map_mem_to_cmd() below..
154 	 */
155 	if (se_cmd->se_cmd_flags & SCF_BIDI) {
156 		struct scsi_data_buffer *sdb = scsi_in(sc);
157 
158 		sgl_bidi = sdb->table.sgl;
159 		sgl_bidi_count = sdb->table.nents;
160 	}
161 	/*
162 	 * Because some userspace code via scsi-generic do not memset their
163 	 * associated read buffers, go ahead and do that here for type
164 	 * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
165 	 * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
166 	 * by target core in transport_generic_allocate_tasks() ->
167 	 * transport_generic_cmd_sequencer().
168 	 */
169 	if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
170 	    se_cmd->data_direction == DMA_FROM_DEVICE) {
171 		struct scatterlist *sg = scsi_sglist(sc);
172 		unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
173 
174 		if (buf != NULL) {
175 			memset(buf, 0, sg->length);
176 			kunmap(sg_page(sg));
177 		}
178 	}
179 
180 	/* Tell the core about our preallocated memory */
181 	return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
182 			scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
183 }
184 
185 /*
186  * Called from struct target_core_fabric_ops->check_stop_free()
187  */
188 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
189 {
190 	/*
191 	 * Do not release struct se_cmd's containing a valid TMR
192 	 * pointer.  These will be released directly in tcm_loop_device_reset()
193 	 * with transport_generic_free_cmd().
194 	 */
195 	if (se_cmd->se_tmr_req)
196 		return 0;
197 	/*
198 	 * Release the struct se_cmd, which will make a callback to release
199 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
200 	 */
201 	transport_generic_free_cmd(se_cmd, 0);
202 	return 1;
203 }
204 
205 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
206 {
207 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
208 				struct tcm_loop_cmd, tl_se_cmd);
209 
210 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
211 }
212 
213 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
214 				char **start, off_t offset,
215 				int length, int inout)
216 {
217 	return sprintf(buffer, "tcm_loop_proc_info()\n");
218 }
219 
220 static int tcm_loop_driver_probe(struct device *);
221 static int tcm_loop_driver_remove(struct device *);
222 
223 static int pseudo_lld_bus_match(struct device *dev,
224 				struct device_driver *dev_driver)
225 {
226 	return 1;
227 }
228 
229 static struct bus_type tcm_loop_lld_bus = {
230 	.name			= "tcm_loop_bus",
231 	.match			= pseudo_lld_bus_match,
232 	.probe			= tcm_loop_driver_probe,
233 	.remove			= tcm_loop_driver_remove,
234 };
235 
236 static struct device_driver tcm_loop_driverfs = {
237 	.name			= "tcm_loop",
238 	.bus			= &tcm_loop_lld_bus,
239 };
240 /*
241  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
242  */
243 struct device *tcm_loop_primary;
244 
245 /*
246  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
247  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
248  */
249 static int tcm_loop_change_queue_depth(
250 	struct scsi_device *sdev,
251 	int depth,
252 	int reason)
253 {
254 	switch (reason) {
255 	case SCSI_QDEPTH_DEFAULT:
256 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
257 		break;
258 	case SCSI_QDEPTH_QFULL:
259 		scsi_track_queue_full(sdev, depth);
260 		break;
261 	case SCSI_QDEPTH_RAMP_UP:
262 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
263 		break;
264 	default:
265 		return -EOPNOTSUPP;
266 	}
267 	return sdev->queue_depth;
268 }
269 
270 /*
271  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
272  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
273  */
274 static int tcm_loop_queuecommand(
275 	struct Scsi_Host *sh,
276 	struct scsi_cmnd *sc)
277 {
278 	struct se_cmd *se_cmd;
279 	struct se_portal_group *se_tpg;
280 	struct tcm_loop_hba *tl_hba;
281 	struct tcm_loop_tpg *tl_tpg;
282 
283 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
284 		" scsi_buf_len: %u\n", sc->device->host->host_no,
285 		sc->device->id, sc->device->channel, sc->device->lun,
286 		sc->cmnd[0], scsi_bufflen(sc));
287 	/*
288 	 * Locate the tcm_loop_hba_t pointer
289 	 */
290 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
291 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
292 	/*
293 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
294 	 * has already been configured via tcm_loop_make_naa_tpg().
295 	 */
296 	if (!tl_tpg->tl_hba) {
297 		set_host_byte(sc, DID_NO_CONNECT);
298 		sc->scsi_done(sc);
299 		return 0;
300 	}
301 	se_tpg = &tl_tpg->tl_se_tpg;
302 	/*
303 	 * Determine the SAM Task Attribute and allocate tl_cmd and
304 	 * tl_cmd->tl_se_cmd from TCM infrastructure
305 	 */
306 	se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
307 	if (!se_cmd) {
308 		sc->scsi_done(sc);
309 		return 0;
310 	}
311 	/*
312 	 * Queue up the newly allocated to be processed in TCM thread context.
313 	*/
314 	transport_generic_handle_cdb_map(se_cmd);
315 	return 0;
316 }
317 
318 /*
319  * Called from SCSI EH process context to issue a LUN_RESET TMR
320  * to struct scsi_device
321  */
322 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
323 {
324 	struct se_cmd *se_cmd = NULL;
325 	struct se_portal_group *se_tpg;
326 	struct se_session *se_sess;
327 	struct tcm_loop_cmd *tl_cmd = NULL;
328 	struct tcm_loop_hba *tl_hba;
329 	struct tcm_loop_nexus *tl_nexus;
330 	struct tcm_loop_tmr *tl_tmr = NULL;
331 	struct tcm_loop_tpg *tl_tpg;
332 	int ret = FAILED;
333 	/*
334 	 * Locate the tcm_loop_hba_t pointer
335 	 */
336 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
337 	/*
338 	 * Locate the tl_nexus and se_sess pointers
339 	 */
340 	tl_nexus = tl_hba->tl_nexus;
341 	if (!tl_nexus) {
342 		pr_err("Unable to perform device reset without"
343 				" active I_T Nexus\n");
344 		return FAILED;
345 	}
346 	se_sess = tl_nexus->se_sess;
347 	/*
348 	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
349 	 */
350 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
351 	se_tpg = &tl_tpg->tl_se_tpg;
352 
353 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
354 	if (!tl_cmd) {
355 		pr_err("Unable to allocate memory for tl_cmd\n");
356 		return FAILED;
357 	}
358 
359 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
360 	if (!tl_tmr) {
361 		pr_err("Unable to allocate memory for tl_tmr\n");
362 		goto release;
363 	}
364 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
365 
366 	se_cmd = &tl_cmd->tl_se_cmd;
367 	/*
368 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
369 	 */
370 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
371 				DMA_NONE, MSG_SIMPLE_TAG,
372 				&tl_cmd->tl_sense_buf[0]);
373 	/*
374 	 * Allocate the LUN_RESET TMR
375 	 */
376 	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
377 						TMR_LUN_RESET, GFP_KERNEL);
378 	if (IS_ERR(se_cmd->se_tmr_req))
379 		goto release;
380 	/*
381 	 * Locate the underlying TCM struct se_lun from sc->device->lun
382 	 */
383 	if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
384 		goto release;
385 	/*
386 	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
387 	 * to wake us up.
388 	 */
389 	transport_generic_handle_tmr(se_cmd);
390 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
391 	/*
392 	 * The TMR LUN_RESET has completed, check the response status and
393 	 * then release allocations.
394 	 */
395 	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
396 		SUCCESS : FAILED;
397 release:
398 	if (se_cmd)
399 		transport_generic_free_cmd(se_cmd, 1);
400 	else
401 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
402 	kfree(tl_tmr);
403 	return ret;
404 }
405 
406 static int tcm_loop_slave_alloc(struct scsi_device *sd)
407 {
408 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
409 	return 0;
410 }
411 
412 static int tcm_loop_slave_configure(struct scsi_device *sd)
413 {
414 	return 0;
415 }
416 
417 static struct scsi_host_template tcm_loop_driver_template = {
418 	.proc_info		= tcm_loop_proc_info,
419 	.proc_name		= "tcm_loopback",
420 	.name			= "TCM_Loopback",
421 	.queuecommand		= tcm_loop_queuecommand,
422 	.change_queue_depth	= tcm_loop_change_queue_depth,
423 	.eh_device_reset_handler = tcm_loop_device_reset,
424 	.can_queue		= TL_SCSI_CAN_QUEUE,
425 	.this_id		= -1,
426 	.sg_tablesize		= TL_SCSI_SG_TABLESIZE,
427 	.cmd_per_lun		= TL_SCSI_CMD_PER_LUN,
428 	.max_sectors		= TL_SCSI_MAX_SECTORS,
429 	.use_clustering		= DISABLE_CLUSTERING,
430 	.slave_alloc		= tcm_loop_slave_alloc,
431 	.slave_configure	= tcm_loop_slave_configure,
432 	.module			= THIS_MODULE,
433 };
434 
435 static int tcm_loop_driver_probe(struct device *dev)
436 {
437 	struct tcm_loop_hba *tl_hba;
438 	struct Scsi_Host *sh;
439 	int error;
440 
441 	tl_hba = to_tcm_loop_hba(dev);
442 
443 	sh = scsi_host_alloc(&tcm_loop_driver_template,
444 			sizeof(struct tcm_loop_hba));
445 	if (!sh) {
446 		pr_err("Unable to allocate struct scsi_host\n");
447 		return -ENODEV;
448 	}
449 	tl_hba->sh = sh;
450 
451 	/*
452 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
453 	 */
454 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
455 	/*
456 	 * Setup single ID, Channel and LUN for now..
457 	 */
458 	sh->max_id = 2;
459 	sh->max_lun = 0;
460 	sh->max_channel = 0;
461 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
462 
463 	error = scsi_add_host(sh, &tl_hba->dev);
464 	if (error) {
465 		pr_err("%s: scsi_add_host failed\n", __func__);
466 		scsi_host_put(sh);
467 		return -ENODEV;
468 	}
469 	return 0;
470 }
471 
472 static int tcm_loop_driver_remove(struct device *dev)
473 {
474 	struct tcm_loop_hba *tl_hba;
475 	struct Scsi_Host *sh;
476 
477 	tl_hba = to_tcm_loop_hba(dev);
478 	sh = tl_hba->sh;
479 
480 	scsi_remove_host(sh);
481 	scsi_host_put(sh);
482 	return 0;
483 }
484 
485 static void tcm_loop_release_adapter(struct device *dev)
486 {
487 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
488 
489 	kfree(tl_hba);
490 }
491 
492 /*
493  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
494  */
495 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
496 {
497 	int ret;
498 
499 	tl_hba->dev.bus = &tcm_loop_lld_bus;
500 	tl_hba->dev.parent = tcm_loop_primary;
501 	tl_hba->dev.release = &tcm_loop_release_adapter;
502 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
503 
504 	ret = device_register(&tl_hba->dev);
505 	if (ret) {
506 		pr_err("device_register() failed for"
507 				" tl_hba->dev: %d\n", ret);
508 		return -ENODEV;
509 	}
510 
511 	return 0;
512 }
513 
514 /*
515  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
516  * tcm_loop SCSI bus.
517  */
518 static int tcm_loop_alloc_core_bus(void)
519 {
520 	int ret;
521 
522 	tcm_loop_primary = root_device_register("tcm_loop_0");
523 	if (IS_ERR(tcm_loop_primary)) {
524 		pr_err("Unable to allocate tcm_loop_primary\n");
525 		return PTR_ERR(tcm_loop_primary);
526 	}
527 
528 	ret = bus_register(&tcm_loop_lld_bus);
529 	if (ret) {
530 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
531 		goto dev_unreg;
532 	}
533 
534 	ret = driver_register(&tcm_loop_driverfs);
535 	if (ret) {
536 		pr_err("driver_register() failed for"
537 				"tcm_loop_driverfs\n");
538 		goto bus_unreg;
539 	}
540 
541 	pr_debug("Initialized TCM Loop Core Bus\n");
542 	return ret;
543 
544 bus_unreg:
545 	bus_unregister(&tcm_loop_lld_bus);
546 dev_unreg:
547 	root_device_unregister(tcm_loop_primary);
548 	return ret;
549 }
550 
551 static void tcm_loop_release_core_bus(void)
552 {
553 	driver_unregister(&tcm_loop_driverfs);
554 	bus_unregister(&tcm_loop_lld_bus);
555 	root_device_unregister(tcm_loop_primary);
556 
557 	pr_debug("Releasing TCM Loop Core BUS\n");
558 }
559 
560 static char *tcm_loop_get_fabric_name(void)
561 {
562 	return "loopback";
563 }
564 
565 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
566 {
567 	struct tcm_loop_tpg *tl_tpg =
568 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
569 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
570 	/*
571 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
572 	 * time based on the protocol dependent prefix of the passed configfs group.
573 	 *
574 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
575 	 * ProtocolID using target_core_fabric_lib.c symbols.
576 	 */
577 	switch (tl_hba->tl_proto_id) {
578 	case SCSI_PROTOCOL_SAS:
579 		return sas_get_fabric_proto_ident(se_tpg);
580 	case SCSI_PROTOCOL_FCP:
581 		return fc_get_fabric_proto_ident(se_tpg);
582 	case SCSI_PROTOCOL_ISCSI:
583 		return iscsi_get_fabric_proto_ident(se_tpg);
584 	default:
585 		pr_err("Unknown tl_proto_id: 0x%02x, using"
586 			" SAS emulation\n", tl_hba->tl_proto_id);
587 		break;
588 	}
589 
590 	return sas_get_fabric_proto_ident(se_tpg);
591 }
592 
593 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
594 {
595 	struct tcm_loop_tpg *tl_tpg =
596 		(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
597 	/*
598 	 * Return the passed NAA identifier for the SAS Target Port
599 	 */
600 	return &tl_tpg->tl_hba->tl_wwn_address[0];
601 }
602 
603 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
604 {
605 	struct tcm_loop_tpg *tl_tpg =
606 		(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
607 	/*
608 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
609 	 * to represent the SCSI Target Port.
610 	 */
611 	return tl_tpg->tl_tpgt;
612 }
613 
614 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
615 {
616 	return 1;
617 }
618 
619 static u32 tcm_loop_get_pr_transport_id(
620 	struct se_portal_group *se_tpg,
621 	struct se_node_acl *se_nacl,
622 	struct t10_pr_registration *pr_reg,
623 	int *format_code,
624 	unsigned char *buf)
625 {
626 	struct tcm_loop_tpg *tl_tpg =
627 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
628 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
629 
630 	switch (tl_hba->tl_proto_id) {
631 	case SCSI_PROTOCOL_SAS:
632 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
633 					format_code, buf);
634 	case SCSI_PROTOCOL_FCP:
635 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
636 					format_code, buf);
637 	case SCSI_PROTOCOL_ISCSI:
638 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
639 					format_code, buf);
640 	default:
641 		pr_err("Unknown tl_proto_id: 0x%02x, using"
642 			" SAS emulation\n", tl_hba->tl_proto_id);
643 		break;
644 	}
645 
646 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
647 			format_code, buf);
648 }
649 
650 static u32 tcm_loop_get_pr_transport_id_len(
651 	struct se_portal_group *se_tpg,
652 	struct se_node_acl *se_nacl,
653 	struct t10_pr_registration *pr_reg,
654 	int *format_code)
655 {
656 	struct tcm_loop_tpg *tl_tpg =
657 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
658 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
659 
660 	switch (tl_hba->tl_proto_id) {
661 	case SCSI_PROTOCOL_SAS:
662 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
663 					format_code);
664 	case SCSI_PROTOCOL_FCP:
665 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
666 					format_code);
667 	case SCSI_PROTOCOL_ISCSI:
668 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
669 					format_code);
670 	default:
671 		pr_err("Unknown tl_proto_id: 0x%02x, using"
672 			" SAS emulation\n", tl_hba->tl_proto_id);
673 		break;
674 	}
675 
676 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
677 			format_code);
678 }
679 
680 /*
681  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
682  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
683  */
684 static char *tcm_loop_parse_pr_out_transport_id(
685 	struct se_portal_group *se_tpg,
686 	const char *buf,
687 	u32 *out_tid_len,
688 	char **port_nexus_ptr)
689 {
690 	struct tcm_loop_tpg *tl_tpg =
691 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
692 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
693 
694 	switch (tl_hba->tl_proto_id) {
695 	case SCSI_PROTOCOL_SAS:
696 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
697 					port_nexus_ptr);
698 	case SCSI_PROTOCOL_FCP:
699 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
700 					port_nexus_ptr);
701 	case SCSI_PROTOCOL_ISCSI:
702 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
703 					port_nexus_ptr);
704 	default:
705 		pr_err("Unknown tl_proto_id: 0x%02x, using"
706 			" SAS emulation\n", tl_hba->tl_proto_id);
707 		break;
708 	}
709 
710 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
711 			port_nexus_ptr);
712 }
713 
714 /*
715  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
716  * based upon the incoming fabric dependent SCSI Initiator Port
717  */
718 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
719 {
720 	return 1;
721 }
722 
723 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
724 {
725 	return 0;
726 }
727 
728 /*
729  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
730  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
731  */
732 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
733 {
734 	return 0;
735 }
736 
737 /*
738  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
739  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
740  * It has been added here as a nop for target_fabric_tf_ops_check()
741  */
742 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
743 {
744 	return 0;
745 }
746 
747 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
748 	struct se_portal_group *se_tpg)
749 {
750 	struct tcm_loop_nacl *tl_nacl;
751 
752 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
753 	if (!tl_nacl) {
754 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
755 		return NULL;
756 	}
757 
758 	return &tl_nacl->se_node_acl;
759 }
760 
761 static void tcm_loop_tpg_release_fabric_acl(
762 	struct se_portal_group *se_tpg,
763 	struct se_node_acl *se_nacl)
764 {
765 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
766 				struct tcm_loop_nacl, se_node_acl);
767 
768 	kfree(tl_nacl);
769 }
770 
771 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
772 {
773 	return 1;
774 }
775 
776 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
777 {
778 	/*
779 	 * Assume struct scsi_cmnd is not in remove state..
780 	 */
781 	return 0;
782 }
783 
784 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
785 {
786 	/*
787 	 * Assume that TL Nexus is always active
788 	 */
789 	return 1;
790 }
791 
792 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
793 {
794 	return 1;
795 }
796 
797 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
798 {
799 	return;
800 }
801 
802 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
803 {
804 	return 1;
805 }
806 
807 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
808 {
809 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
810 			struct tcm_loop_cmd, tl_se_cmd);
811 
812 	return tl_cmd->sc_cmd_state;
813 }
814 
815 static int tcm_loop_shutdown_session(struct se_session *se_sess)
816 {
817 	return 0;
818 }
819 
820 static void tcm_loop_close_session(struct se_session *se_sess)
821 {
822 	return;
823 };
824 
825 static void tcm_loop_stop_session(
826 	struct se_session *se_sess,
827 	int sess_sleep,
828 	int conn_sleep)
829 {
830 	return;
831 }
832 
833 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
834 {
835 	return;
836 }
837 
838 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
839 {
840 	/*
841 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
842 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
843 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
844 	 * format with transport_generic_map_mem_to_cmd().
845 	 *
846 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
847 	 * object execution queue.
848 	 */
849 	transport_generic_process_write(se_cmd);
850 	return 0;
851 }
852 
853 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
854 {
855 	return 0;
856 }
857 
858 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
859 {
860 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
861 				struct tcm_loop_cmd, tl_se_cmd);
862 	struct scsi_cmnd *sc = tl_cmd->sc;
863 
864 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
865 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
866 
867 	sc->result = SAM_STAT_GOOD;
868 	set_host_byte(sc, DID_OK);
869 	sc->scsi_done(sc);
870 	return 0;
871 }
872 
873 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
874 {
875 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
876 				struct tcm_loop_cmd, tl_se_cmd);
877 	struct scsi_cmnd *sc = tl_cmd->sc;
878 
879 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
880 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
881 
882 	if (se_cmd->sense_buffer &&
883 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
884 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
885 
886 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
887 				SCSI_SENSE_BUFFERSIZE);
888 		sc->result = SAM_STAT_CHECK_CONDITION;
889 		set_driver_byte(sc, DRIVER_SENSE);
890 	} else
891 		sc->result = se_cmd->scsi_status;
892 
893 	set_host_byte(sc, DID_OK);
894 	sc->scsi_done(sc);
895 	return 0;
896 }
897 
898 static int 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 	return 0;
909 }
910 
911 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
912 {
913 	return 0;
914 }
915 
916 static u16 tcm_loop_get_fabric_sense_len(void)
917 {
918 	return 0;
919 }
920 
921 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
922 {
923 	switch (tl_hba->tl_proto_id) {
924 	case SCSI_PROTOCOL_SAS:
925 		return "SAS";
926 	case SCSI_PROTOCOL_FCP:
927 		return "FCP";
928 	case SCSI_PROTOCOL_ISCSI:
929 		return "iSCSI";
930 	default:
931 		break;
932 	}
933 
934 	return "Unknown";
935 }
936 
937 /* Start items for tcm_loop_port_cit */
938 
939 static int tcm_loop_port_link(
940 	struct se_portal_group *se_tpg,
941 	struct se_lun *lun)
942 {
943 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
944 				struct tcm_loop_tpg, tl_se_tpg);
945 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
946 
947 	atomic_inc(&tl_tpg->tl_tpg_port_count);
948 	smp_mb__after_atomic_inc();
949 	/*
950 	 * Add Linux/SCSI struct scsi_device by HCTL
951 	 */
952 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
953 
954 	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
955 	return 0;
956 }
957 
958 static void tcm_loop_port_unlink(
959 	struct se_portal_group *se_tpg,
960 	struct se_lun *se_lun)
961 {
962 	struct scsi_device *sd;
963 	struct tcm_loop_hba *tl_hba;
964 	struct tcm_loop_tpg *tl_tpg;
965 
966 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
967 	tl_hba = tl_tpg->tl_hba;
968 
969 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
970 				se_lun->unpacked_lun);
971 	if (!sd) {
972 		pr_err("Unable to locate struct scsi_device for %d:%d:"
973 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
974 		return;
975 	}
976 	/*
977 	 * Remove Linux/SCSI struct scsi_device by HCTL
978 	 */
979 	scsi_remove_device(sd);
980 	scsi_device_put(sd);
981 
982 	atomic_dec(&tl_tpg->tl_tpg_port_count);
983 	smp_mb__after_atomic_dec();
984 
985 	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
986 }
987 
988 /* End items for tcm_loop_port_cit */
989 
990 /* Start items for tcm_loop_nexus_cit */
991 
992 static int tcm_loop_make_nexus(
993 	struct tcm_loop_tpg *tl_tpg,
994 	const char *name)
995 {
996 	struct se_portal_group *se_tpg;
997 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
998 	struct tcm_loop_nexus *tl_nexus;
999 	int ret = -ENOMEM;
1000 
1001 	if (tl_tpg->tl_hba->tl_nexus) {
1002 		pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
1003 		return -EEXIST;
1004 	}
1005 	se_tpg = &tl_tpg->tl_se_tpg;
1006 
1007 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1008 	if (!tl_nexus) {
1009 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
1010 		return -ENOMEM;
1011 	}
1012 	/*
1013 	 * Initialize the struct se_session pointer
1014 	 */
1015 	tl_nexus->se_sess = transport_init_session();
1016 	if (IS_ERR(tl_nexus->se_sess)) {
1017 		ret = PTR_ERR(tl_nexus->se_sess);
1018 		goto out;
1019 	}
1020 	/*
1021 	 * Since we are running in 'demo mode' this call with generate a
1022 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1023 	 * Initiator port name of the passed configfs group 'name'.
1024 	 */
1025 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1026 				se_tpg, (unsigned char *)name);
1027 	if (!tl_nexus->se_sess->se_node_acl) {
1028 		transport_free_session(tl_nexus->se_sess);
1029 		goto out;
1030 	}
1031 	/*
1032 	 * Now, register the SAS I_T Nexus as active with the call to
1033 	 * transport_register_session()
1034 	 */
1035 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1036 			tl_nexus->se_sess, tl_nexus);
1037 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
1038 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1039 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1040 		name);
1041 	return 0;
1042 
1043 out:
1044 	kfree(tl_nexus);
1045 	return ret;
1046 }
1047 
1048 static int tcm_loop_drop_nexus(
1049 	struct tcm_loop_tpg *tpg)
1050 {
1051 	struct se_session *se_sess;
1052 	struct tcm_loop_nexus *tl_nexus;
1053 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1054 
1055 	tl_nexus = tpg->tl_hba->tl_nexus;
1056 	if (!tl_nexus)
1057 		return -ENODEV;
1058 
1059 	se_sess = tl_nexus->se_sess;
1060 	if (!se_sess)
1061 		return -ENODEV;
1062 
1063 	if (atomic_read(&tpg->tl_tpg_port_count)) {
1064 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
1065 			" active TPG port count: %d\n",
1066 			atomic_read(&tpg->tl_tpg_port_count));
1067 		return -EPERM;
1068 	}
1069 
1070 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1071 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1072 		tl_nexus->se_sess->se_node_acl->initiatorname);
1073 	/*
1074 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
1075 	 */
1076 	transport_deregister_session(tl_nexus->se_sess);
1077 	tpg->tl_hba->tl_nexus = NULL;
1078 	kfree(tl_nexus);
1079 	return 0;
1080 }
1081 
1082 /* End items for tcm_loop_nexus_cit */
1083 
1084 static ssize_t tcm_loop_tpg_show_nexus(
1085 	struct se_portal_group *se_tpg,
1086 	char *page)
1087 {
1088 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1089 			struct tcm_loop_tpg, tl_se_tpg);
1090 	struct tcm_loop_nexus *tl_nexus;
1091 	ssize_t ret;
1092 
1093 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
1094 	if (!tl_nexus)
1095 		return -ENODEV;
1096 
1097 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1098 		tl_nexus->se_sess->se_node_acl->initiatorname);
1099 
1100 	return ret;
1101 }
1102 
1103 static ssize_t tcm_loop_tpg_store_nexus(
1104 	struct se_portal_group *se_tpg,
1105 	const char *page,
1106 	size_t count)
1107 {
1108 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1109 			struct tcm_loop_tpg, tl_se_tpg);
1110 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1111 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1112 	int ret;
1113 	/*
1114 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1115 	 */
1116 	if (!strncmp(page, "NULL", 4)) {
1117 		ret = tcm_loop_drop_nexus(tl_tpg);
1118 		return (!ret) ? count : ret;
1119 	}
1120 	/*
1121 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1122 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1123 	 * tcm_loop_make_nexus()
1124 	 */
1125 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1126 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1127 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1128 		return -EINVAL;
1129 	}
1130 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1131 
1132 	ptr = strstr(i_port, "naa.");
1133 	if (ptr) {
1134 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1135 			pr_err("Passed SAS Initiator Port %s does not"
1136 				" match target port protoid: %s\n", i_port,
1137 				tcm_loop_dump_proto_id(tl_hba));
1138 			return -EINVAL;
1139 		}
1140 		port_ptr = &i_port[0];
1141 		goto check_newline;
1142 	}
1143 	ptr = strstr(i_port, "fc.");
1144 	if (ptr) {
1145 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1146 			pr_err("Passed FCP Initiator Port %s does not"
1147 				" match target port protoid: %s\n", i_port,
1148 				tcm_loop_dump_proto_id(tl_hba));
1149 			return -EINVAL;
1150 		}
1151 		port_ptr = &i_port[3]; /* Skip over "fc." */
1152 		goto check_newline;
1153 	}
1154 	ptr = strstr(i_port, "iqn.");
1155 	if (ptr) {
1156 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1157 			pr_err("Passed iSCSI Initiator Port %s does not"
1158 				" match target port protoid: %s\n", i_port,
1159 				tcm_loop_dump_proto_id(tl_hba));
1160 			return -EINVAL;
1161 		}
1162 		port_ptr = &i_port[0];
1163 		goto check_newline;
1164 	}
1165 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1166 			" %s\n", i_port);
1167 	return -EINVAL;
1168 	/*
1169 	 * Clear any trailing newline for the NAA WWN
1170 	 */
1171 check_newline:
1172 	if (i_port[strlen(i_port)-1] == '\n')
1173 		i_port[strlen(i_port)-1] = '\0';
1174 
1175 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1176 	if (ret < 0)
1177 		return ret;
1178 
1179 	return count;
1180 }
1181 
1182 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1183 
1184 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1185 	&tcm_loop_tpg_nexus.attr,
1186 	NULL,
1187 };
1188 
1189 /* Start items for tcm_loop_naa_cit */
1190 
1191 struct se_portal_group *tcm_loop_make_naa_tpg(
1192 	struct se_wwn *wwn,
1193 	struct config_group *group,
1194 	const char *name)
1195 {
1196 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1197 			struct tcm_loop_hba, tl_hba_wwn);
1198 	struct tcm_loop_tpg *tl_tpg;
1199 	char *tpgt_str, *end_ptr;
1200 	int ret;
1201 	unsigned short int tpgt;
1202 
1203 	tpgt_str = strstr(name, "tpgt_");
1204 	if (!tpgt_str) {
1205 		pr_err("Unable to locate \"tpgt_#\" directory"
1206 				" group\n");
1207 		return ERR_PTR(-EINVAL);
1208 	}
1209 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1210 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1211 
1212 	if (tpgt >= TL_TPGS_PER_HBA) {
1213 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1214 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1215 		return ERR_PTR(-EINVAL);
1216 	}
1217 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1218 	tl_tpg->tl_hba = tl_hba;
1219 	tl_tpg->tl_tpgt = tpgt;
1220 	/*
1221 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1222 	 */
1223 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1224 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1225 			TRANSPORT_TPG_TYPE_NORMAL);
1226 	if (ret < 0)
1227 		return ERR_PTR(-ENOMEM);
1228 
1229 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1230 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1231 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1232 
1233 	return &tl_tpg->tl_se_tpg;
1234 }
1235 
1236 void tcm_loop_drop_naa_tpg(
1237 	struct se_portal_group *se_tpg)
1238 {
1239 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1240 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1241 				struct tcm_loop_tpg, tl_se_tpg);
1242 	struct tcm_loop_hba *tl_hba;
1243 	unsigned short tpgt;
1244 
1245 	tl_hba = tl_tpg->tl_hba;
1246 	tpgt = tl_tpg->tl_tpgt;
1247 	/*
1248 	 * Release the I_T Nexus for the Virtual SAS link if present
1249 	 */
1250 	tcm_loop_drop_nexus(tl_tpg);
1251 	/*
1252 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1253 	 */
1254 	core_tpg_deregister(se_tpg);
1255 
1256 	tl_tpg->tl_hba = NULL;
1257 	tl_tpg->tl_tpgt = 0;
1258 
1259 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1260 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1261 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1262 }
1263 
1264 /* End items for tcm_loop_naa_cit */
1265 
1266 /* Start items for tcm_loop_cit */
1267 
1268 struct se_wwn *tcm_loop_make_scsi_hba(
1269 	struct target_fabric_configfs *tf,
1270 	struct config_group *group,
1271 	const char *name)
1272 {
1273 	struct tcm_loop_hba *tl_hba;
1274 	struct Scsi_Host *sh;
1275 	char *ptr;
1276 	int ret, off = 0;
1277 
1278 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1279 	if (!tl_hba) {
1280 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1281 		return ERR_PTR(-ENOMEM);
1282 	}
1283 	/*
1284 	 * Determine the emulated Protocol Identifier and Target Port Name
1285 	 * based on the incoming configfs directory name.
1286 	 */
1287 	ptr = strstr(name, "naa.");
1288 	if (ptr) {
1289 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1290 		goto check_len;
1291 	}
1292 	ptr = strstr(name, "fc.");
1293 	if (ptr) {
1294 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1295 		off = 3; /* Skip over "fc." */
1296 		goto check_len;
1297 	}
1298 	ptr = strstr(name, "iqn.");
1299 	if (!ptr) {
1300 		pr_err("Unable to locate prefix for emulated Target "
1301 				"Port: %s\n", name);
1302 		ret = -EINVAL;
1303 		goto out;
1304 	}
1305 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1306 
1307 check_len:
1308 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1309 		pr_err("Emulated NAA %s Address: %s, exceeds"
1310 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1311 			TL_WWN_ADDR_LEN);
1312 		ret = -EINVAL;
1313 		goto out;
1314 	}
1315 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1316 
1317 	/*
1318 	 * Call device_register(tl_hba->dev) to register the emulated
1319 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1320 	 * device_register() callbacks in tcm_loop_driver_probe()
1321 	 */
1322 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1323 	if (ret)
1324 		goto out;
1325 
1326 	sh = tl_hba->sh;
1327 	tcm_loop_hba_no_cnt++;
1328 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1329 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1330 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1331 
1332 	return &tl_hba->tl_hba_wwn;
1333 out:
1334 	kfree(tl_hba);
1335 	return ERR_PTR(ret);
1336 }
1337 
1338 void tcm_loop_drop_scsi_hba(
1339 	struct se_wwn *wwn)
1340 {
1341 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1342 				struct tcm_loop_hba, tl_hba_wwn);
1343 
1344 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1345 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1346 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1347 	/*
1348 	 * Call device_unregister() on the original tl_hba->dev.
1349 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1350 	 * release *tl_hba;
1351 	 */
1352 	device_unregister(&tl_hba->dev);
1353 }
1354 
1355 /* Start items for tcm_loop_cit */
1356 static ssize_t tcm_loop_wwn_show_attr_version(
1357 	struct target_fabric_configfs *tf,
1358 	char *page)
1359 {
1360 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1361 }
1362 
1363 TF_WWN_ATTR_RO(tcm_loop, version);
1364 
1365 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1366 	&tcm_loop_wwn_version.attr,
1367 	NULL,
1368 };
1369 
1370 /* End items for tcm_loop_cit */
1371 
1372 static int tcm_loop_register_configfs(void)
1373 {
1374 	struct target_fabric_configfs *fabric;
1375 	struct config_group *tf_cg;
1376 	int ret;
1377 	/*
1378 	 * Set the TCM Loop HBA counter to zero
1379 	 */
1380 	tcm_loop_hba_no_cnt = 0;
1381 	/*
1382 	 * Register the top level struct config_item_type with TCM core
1383 	 */
1384 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1385 	if (IS_ERR(fabric)) {
1386 		pr_err("tcm_loop_register_configfs() failed!\n");
1387 		return PTR_ERR(fabric);
1388 	}
1389 	/*
1390 	 * Setup the fabric API of function pointers used by target_core_mod
1391 	 */
1392 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1393 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1394 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1395 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1396 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1397 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1398 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1399 					&tcm_loop_get_pr_transport_id_len;
1400 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1401 					&tcm_loop_parse_pr_out_transport_id;
1402 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1403 	fabric->tf_ops.tpg_check_demo_mode_cache =
1404 					&tcm_loop_check_demo_mode_cache;
1405 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1406 					&tcm_loop_check_demo_mode_write_protect;
1407 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1408 					&tcm_loop_check_prod_mode_write_protect;
1409 	/*
1410 	 * The TCM loopback fabric module runs in demo-mode to a local
1411 	 * virtual SCSI device, so fabric dependent initator ACLs are
1412 	 * not required.
1413 	 */
1414 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1415 	fabric->tf_ops.tpg_release_fabric_acl =
1416 					&tcm_loop_tpg_release_fabric_acl;
1417 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1418 	/*
1419 	 * Used for setting up remaining TCM resources in process context
1420 	 */
1421 	fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1422 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1423 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1424 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1425 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1426 	fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1427 	fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1428 	fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1429 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1430 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1431 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1432 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1433 	/*
1434 	 * Not used for TCM loopback
1435 	 */
1436 	fabric->tf_ops.set_default_node_attributes =
1437 					&tcm_loop_set_default_node_attributes;
1438 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1439 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1440 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1441 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1442 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1443 	fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1444 	fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1445 	fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1446 
1447 	tf_cg = &fabric->tf_group;
1448 	/*
1449 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1450 	 */
1451 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1452 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1453 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1454 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1455 	/*
1456 	 * fabric_post_link() and fabric_pre_unlink() are used for
1457 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1458 	 */
1459 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1460 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1461 	fabric->tf_ops.fabric_make_np = NULL;
1462 	fabric->tf_ops.fabric_drop_np = NULL;
1463 	/*
1464 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1465 	 */
1466 	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1467 	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1468 	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1469 	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1470 	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1471 	/*
1472 	 * Once fabric->tf_ops has been setup, now register the fabric for
1473 	 * use within TCM
1474 	 */
1475 	ret = target_fabric_configfs_register(fabric);
1476 	if (ret < 0) {
1477 		pr_err("target_fabric_configfs_register() for"
1478 				" TCM_Loop failed!\n");
1479 		target_fabric_configfs_free(fabric);
1480 		return -1;
1481 	}
1482 	/*
1483 	 * Setup our local pointer to *fabric.
1484 	 */
1485 	tcm_loop_fabric_configfs = fabric;
1486 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1487 			" tcm_loop_fabric_configfs\n");
1488 	return 0;
1489 }
1490 
1491 static void tcm_loop_deregister_configfs(void)
1492 {
1493 	if (!tcm_loop_fabric_configfs)
1494 		return;
1495 
1496 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1497 	tcm_loop_fabric_configfs = NULL;
1498 	pr_debug("TCM_LOOP[0] - Cleared"
1499 				" tcm_loop_fabric_configfs\n");
1500 }
1501 
1502 static int __init tcm_loop_fabric_init(void)
1503 {
1504 	int ret;
1505 
1506 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1507 				sizeof(struct tcm_loop_cmd),
1508 				__alignof__(struct tcm_loop_cmd),
1509 				0, NULL);
1510 	if (!tcm_loop_cmd_cache) {
1511 		pr_debug("kmem_cache_create() for"
1512 			" tcm_loop_cmd_cache failed\n");
1513 		return -ENOMEM;
1514 	}
1515 
1516 	ret = tcm_loop_alloc_core_bus();
1517 	if (ret)
1518 		return ret;
1519 
1520 	ret = tcm_loop_register_configfs();
1521 	if (ret) {
1522 		tcm_loop_release_core_bus();
1523 		return ret;
1524 	}
1525 
1526 	return 0;
1527 }
1528 
1529 static void __exit tcm_loop_fabric_exit(void)
1530 {
1531 	tcm_loop_deregister_configfs();
1532 	tcm_loop_release_core_bus();
1533 	kmem_cache_destroy(tcm_loop_cmd_cache);
1534 }
1535 
1536 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1537 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1538 MODULE_LICENSE("GPL");
1539 module_init(tcm_loop_fabric_init);
1540 module_exit(tcm_loop_fabric_exit);
1541