xref: /linux/drivers/target/loopback/tcm_loop.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*******************************************************************************
2  *
3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
4  * for emulated SAS initiator ports
5  *
6  * © Copyright 2011 RisingTide Systems LLC.
7  *
8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
9  *
10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  ****************************************************************************/
22 
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/configfs.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_cmnd.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_fabric.h>
37 #include <target/target_core_fabric_configfs.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "tcm_loop.h"
41 
42 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
43 
44 /* Local pointer to allocated TCM configfs fabric module */
45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
46 
47 static struct kmem_cache *tcm_loop_cmd_cache;
48 
49 static int tcm_loop_hba_no_cnt;
50 
51 /*
52  * Allocate a tcm_loop cmd descriptor from target_core_mod code
53  *
54  * Can be called from interrupt context in tcm_loop_queuecommand() below
55  */
56 static struct se_cmd *tcm_loop_allocate_core_cmd(
57 	struct tcm_loop_hba *tl_hba,
58 	struct se_portal_group *se_tpg,
59 	struct scsi_cmnd *sc)
60 {
61 	struct se_cmd *se_cmd;
62 	struct se_session *se_sess;
63 	struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
64 	struct tcm_loop_cmd *tl_cmd;
65 	int sam_task_attr;
66 
67 	if (!tl_nexus) {
68 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
69 				" does not exist\n");
70 		set_host_byte(sc, DID_ERROR);
71 		return NULL;
72 	}
73 	se_sess = tl_nexus->se_sess;
74 
75 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
76 	if (!tl_cmd) {
77 		pr_err("Unable to allocate struct tcm_loop_cmd\n");
78 		set_host_byte(sc, DID_ERROR);
79 		return NULL;
80 	}
81 	se_cmd = &tl_cmd->tl_se_cmd;
82 	/*
83 	 * Save the pointer to struct scsi_cmnd *sc
84 	 */
85 	tl_cmd->sc = sc;
86 	/*
87 	 * Locate the SAM Task Attr from struct scsi_cmnd *
88 	 */
89 	if (sc->device->tagged_supported) {
90 		switch (sc->tag) {
91 		case HEAD_OF_QUEUE_TAG:
92 			sam_task_attr = MSG_HEAD_TAG;
93 			break;
94 		case ORDERED_QUEUE_TAG:
95 			sam_task_attr = MSG_ORDERED_TAG;
96 			break;
97 		default:
98 			sam_task_attr = MSG_SIMPLE_TAG;
99 			break;
100 		}
101 	} else
102 		sam_task_attr = MSG_SIMPLE_TAG;
103 
104 	/*
105 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
106 	 */
107 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
108 			scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
109 			&tl_cmd->tl_sense_buf[0]);
110 
111 	if (scsi_bidi_cmnd(sc))
112 		se_cmd->se_cmd_flags |= SCF_BIDI;
113 
114 	/*
115 	 * Locate the struct se_lun pointer and attach it to struct se_cmd
116 	 */
117 	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
118 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
119 		set_host_byte(sc, DID_NO_CONNECT);
120 		return NULL;
121 	}
122 
123 	return se_cmd;
124 }
125 
126 /*
127  * Called by struct target_core_fabric_ops->new_cmd_map()
128  *
129  * Always called in process context.  A non zero return value
130  * here will signal to handle an exception based on the return code.
131  */
132 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
133 {
134 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
135 				struct tcm_loop_cmd, tl_se_cmd);
136 	struct scsi_cmnd *sc = tl_cmd->sc;
137 	struct scatterlist *sgl_bidi = NULL;
138 	u32 sgl_bidi_count = 0;
139 	int ret;
140 	/*
141 	 * Allocate the necessary tasks to complete the received CDB+data
142 	 */
143 	ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
144 	if (ret != 0)
145 		return ret;
146 	/*
147 	 * For BIDI commands, pass in the extra READ buffer
148 	 * to transport_generic_map_mem_to_cmd() below..
149 	 */
150 	if (se_cmd->se_cmd_flags & SCF_BIDI) {
151 		struct scsi_data_buffer *sdb = scsi_in(sc);
152 
153 		sgl_bidi = sdb->table.sgl;
154 		sgl_bidi_count = sdb->table.nents;
155 	}
156 	/*
157 	 * Because some userspace code via scsi-generic do not memset their
158 	 * associated read buffers, go ahead and do that here for type
159 	 * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
160 	 * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
161 	 * by target core in transport_generic_allocate_tasks() ->
162 	 * transport_generic_cmd_sequencer().
163 	 */
164 	if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
165 	    se_cmd->data_direction == DMA_FROM_DEVICE) {
166 		struct scatterlist *sg = scsi_sglist(sc);
167 		unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
168 
169 		if (buf != NULL) {
170 			memset(buf, 0, sg->length);
171 			kunmap(sg_page(sg));
172 		}
173 	}
174 
175 	/* Tell the core about our preallocated memory */
176 	return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
177 			scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
178 }
179 
180 /*
181  * Called from struct target_core_fabric_ops->check_stop_free()
182  */
183 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
184 {
185 	/*
186 	 * Do not release struct se_cmd's containing a valid TMR
187 	 * pointer.  These will be released directly in tcm_loop_device_reset()
188 	 * with transport_generic_free_cmd().
189 	 */
190 	if (se_cmd->se_tmr_req)
191 		return 0;
192 	/*
193 	 * Release the struct se_cmd, which will make a callback to release
194 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
195 	 */
196 	transport_generic_free_cmd(se_cmd, 0);
197 	return 1;
198 }
199 
200 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
201 {
202 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
203 				struct tcm_loop_cmd, tl_se_cmd);
204 
205 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
206 }
207 
208 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
209 				char **start, off_t offset,
210 				int length, int inout)
211 {
212 	return sprintf(buffer, "tcm_loop_proc_info()\n");
213 }
214 
215 static int tcm_loop_driver_probe(struct device *);
216 static int tcm_loop_driver_remove(struct device *);
217 
218 static int pseudo_lld_bus_match(struct device *dev,
219 				struct device_driver *dev_driver)
220 {
221 	return 1;
222 }
223 
224 static struct bus_type tcm_loop_lld_bus = {
225 	.name			= "tcm_loop_bus",
226 	.match			= pseudo_lld_bus_match,
227 	.probe			= tcm_loop_driver_probe,
228 	.remove			= tcm_loop_driver_remove,
229 };
230 
231 static struct device_driver tcm_loop_driverfs = {
232 	.name			= "tcm_loop",
233 	.bus			= &tcm_loop_lld_bus,
234 };
235 /*
236  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
237  */
238 struct device *tcm_loop_primary;
239 
240 /*
241  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
242  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
243  */
244 static int tcm_loop_change_queue_depth(
245 	struct scsi_device *sdev,
246 	int depth,
247 	int reason)
248 {
249 	switch (reason) {
250 	case SCSI_QDEPTH_DEFAULT:
251 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
252 		break;
253 	case SCSI_QDEPTH_QFULL:
254 		scsi_track_queue_full(sdev, depth);
255 		break;
256 	case SCSI_QDEPTH_RAMP_UP:
257 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
258 		break;
259 	default:
260 		return -EOPNOTSUPP;
261 	}
262 	return sdev->queue_depth;
263 }
264 
265 /*
266  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
267  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
268  */
269 static int tcm_loop_queuecommand(
270 	struct Scsi_Host *sh,
271 	struct scsi_cmnd *sc)
272 {
273 	struct se_cmd *se_cmd;
274 	struct se_portal_group *se_tpg;
275 	struct tcm_loop_hba *tl_hba;
276 	struct tcm_loop_tpg *tl_tpg;
277 
278 	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
279 		" scsi_buf_len: %u\n", sc->device->host->host_no,
280 		sc->device->id, sc->device->channel, sc->device->lun,
281 		sc->cmnd[0], scsi_bufflen(sc));
282 	/*
283 	 * Locate the tcm_loop_hba_t pointer
284 	 */
285 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
286 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
287 	/*
288 	 * Ensure that this tl_tpg reference from the incoming sc->device->id
289 	 * has already been configured via tcm_loop_make_naa_tpg().
290 	 */
291 	if (!tl_tpg->tl_hba) {
292 		set_host_byte(sc, DID_NO_CONNECT);
293 		sc->scsi_done(sc);
294 		return 0;
295 	}
296 	se_tpg = &tl_tpg->tl_se_tpg;
297 	/*
298 	 * Determine the SAM Task Attribute and allocate tl_cmd and
299 	 * tl_cmd->tl_se_cmd from TCM infrastructure
300 	 */
301 	se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
302 	if (!se_cmd) {
303 		sc->scsi_done(sc);
304 		return 0;
305 	}
306 	/*
307 	 * Queue up the newly allocated to be processed in TCM thread context.
308 	*/
309 	transport_generic_handle_cdb_map(se_cmd);
310 	return 0;
311 }
312 
313 /*
314  * Called from SCSI EH process context to issue a LUN_RESET TMR
315  * to struct scsi_device
316  */
317 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
318 {
319 	struct se_cmd *se_cmd = NULL;
320 	struct se_portal_group *se_tpg;
321 	struct se_session *se_sess;
322 	struct tcm_loop_cmd *tl_cmd = NULL;
323 	struct tcm_loop_hba *tl_hba;
324 	struct tcm_loop_nexus *tl_nexus;
325 	struct tcm_loop_tmr *tl_tmr = NULL;
326 	struct tcm_loop_tpg *tl_tpg;
327 	int ret = FAILED;
328 	/*
329 	 * Locate the tcm_loop_hba_t pointer
330 	 */
331 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
332 	/*
333 	 * Locate the tl_nexus and se_sess pointers
334 	 */
335 	tl_nexus = tl_hba->tl_nexus;
336 	if (!tl_nexus) {
337 		pr_err("Unable to perform device reset without"
338 				" active I_T Nexus\n");
339 		return FAILED;
340 	}
341 	se_sess = tl_nexus->se_sess;
342 	/*
343 	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
344 	 */
345 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
346 	se_tpg = &tl_tpg->tl_se_tpg;
347 
348 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
349 	if (!tl_cmd) {
350 		pr_err("Unable to allocate memory for tl_cmd\n");
351 		return FAILED;
352 	}
353 
354 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
355 	if (!tl_tmr) {
356 		pr_err("Unable to allocate memory for tl_tmr\n");
357 		goto release;
358 	}
359 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
360 
361 	se_cmd = &tl_cmd->tl_se_cmd;
362 	/*
363 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
364 	 */
365 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
366 				DMA_NONE, MSG_SIMPLE_TAG,
367 				&tl_cmd->tl_sense_buf[0]);
368 	/*
369 	 * Allocate the LUN_RESET TMR
370 	 */
371 	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
372 						TMR_LUN_RESET, GFP_KERNEL);
373 	if (IS_ERR(se_cmd->se_tmr_req))
374 		goto release;
375 	/*
376 	 * Locate the underlying TCM struct se_lun from sc->device->lun
377 	 */
378 	if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
379 		goto release;
380 	/*
381 	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
382 	 * to wake us up.
383 	 */
384 	transport_generic_handle_tmr(se_cmd);
385 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
386 	/*
387 	 * The TMR LUN_RESET has completed, check the response status and
388 	 * then release allocations.
389 	 */
390 	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
391 		SUCCESS : FAILED;
392 release:
393 	if (se_cmd)
394 		transport_generic_free_cmd(se_cmd, 1);
395 	else
396 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
397 	kfree(tl_tmr);
398 	return ret;
399 }
400 
401 static int tcm_loop_slave_alloc(struct scsi_device *sd)
402 {
403 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
404 	return 0;
405 }
406 
407 static int tcm_loop_slave_configure(struct scsi_device *sd)
408 {
409 	return 0;
410 }
411 
412 static struct scsi_host_template tcm_loop_driver_template = {
413 	.proc_info		= tcm_loop_proc_info,
414 	.proc_name		= "tcm_loopback",
415 	.name			= "TCM_Loopback",
416 	.queuecommand		= tcm_loop_queuecommand,
417 	.change_queue_depth	= tcm_loop_change_queue_depth,
418 	.eh_device_reset_handler = tcm_loop_device_reset,
419 	.can_queue		= 1024,
420 	.this_id		= -1,
421 	.sg_tablesize		= 256,
422 	.cmd_per_lun		= 1024,
423 	.max_sectors		= 0xFFFF,
424 	.use_clustering		= DISABLE_CLUSTERING,
425 	.slave_alloc		= tcm_loop_slave_alloc,
426 	.slave_configure	= tcm_loop_slave_configure,
427 	.module			= THIS_MODULE,
428 };
429 
430 static int tcm_loop_driver_probe(struct device *dev)
431 {
432 	struct tcm_loop_hba *tl_hba;
433 	struct Scsi_Host *sh;
434 	int error;
435 
436 	tl_hba = to_tcm_loop_hba(dev);
437 
438 	sh = scsi_host_alloc(&tcm_loop_driver_template,
439 			sizeof(struct tcm_loop_hba));
440 	if (!sh) {
441 		pr_err("Unable to allocate struct scsi_host\n");
442 		return -ENODEV;
443 	}
444 	tl_hba->sh = sh;
445 
446 	/*
447 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
448 	 */
449 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
450 	/*
451 	 * Setup single ID, Channel and LUN for now..
452 	 */
453 	sh->max_id = 2;
454 	sh->max_lun = 0;
455 	sh->max_channel = 0;
456 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
457 
458 	error = scsi_add_host(sh, &tl_hba->dev);
459 	if (error) {
460 		pr_err("%s: scsi_add_host failed\n", __func__);
461 		scsi_host_put(sh);
462 		return -ENODEV;
463 	}
464 	return 0;
465 }
466 
467 static int tcm_loop_driver_remove(struct device *dev)
468 {
469 	struct tcm_loop_hba *tl_hba;
470 	struct Scsi_Host *sh;
471 
472 	tl_hba = to_tcm_loop_hba(dev);
473 	sh = tl_hba->sh;
474 
475 	scsi_remove_host(sh);
476 	scsi_host_put(sh);
477 	return 0;
478 }
479 
480 static void tcm_loop_release_adapter(struct device *dev)
481 {
482 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
483 
484 	kfree(tl_hba);
485 }
486 
487 /*
488  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
489  */
490 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
491 {
492 	int ret;
493 
494 	tl_hba->dev.bus = &tcm_loop_lld_bus;
495 	tl_hba->dev.parent = tcm_loop_primary;
496 	tl_hba->dev.release = &tcm_loop_release_adapter;
497 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
498 
499 	ret = device_register(&tl_hba->dev);
500 	if (ret) {
501 		pr_err("device_register() failed for"
502 				" tl_hba->dev: %d\n", ret);
503 		return -ENODEV;
504 	}
505 
506 	return 0;
507 }
508 
509 /*
510  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
511  * tcm_loop SCSI bus.
512  */
513 static int tcm_loop_alloc_core_bus(void)
514 {
515 	int ret;
516 
517 	tcm_loop_primary = root_device_register("tcm_loop_0");
518 	if (IS_ERR(tcm_loop_primary)) {
519 		pr_err("Unable to allocate tcm_loop_primary\n");
520 		return PTR_ERR(tcm_loop_primary);
521 	}
522 
523 	ret = bus_register(&tcm_loop_lld_bus);
524 	if (ret) {
525 		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
526 		goto dev_unreg;
527 	}
528 
529 	ret = driver_register(&tcm_loop_driverfs);
530 	if (ret) {
531 		pr_err("driver_register() failed for"
532 				"tcm_loop_driverfs\n");
533 		goto bus_unreg;
534 	}
535 
536 	pr_debug("Initialized TCM Loop Core Bus\n");
537 	return ret;
538 
539 bus_unreg:
540 	bus_unregister(&tcm_loop_lld_bus);
541 dev_unreg:
542 	root_device_unregister(tcm_loop_primary);
543 	return ret;
544 }
545 
546 static void tcm_loop_release_core_bus(void)
547 {
548 	driver_unregister(&tcm_loop_driverfs);
549 	bus_unregister(&tcm_loop_lld_bus);
550 	root_device_unregister(tcm_loop_primary);
551 
552 	pr_debug("Releasing TCM Loop Core BUS\n");
553 }
554 
555 static char *tcm_loop_get_fabric_name(void)
556 {
557 	return "loopback";
558 }
559 
560 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
561 {
562 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
563 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
564 	/*
565 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
566 	 * time based on the protocol dependent prefix of the passed configfs group.
567 	 *
568 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
569 	 * ProtocolID using target_core_fabric_lib.c symbols.
570 	 */
571 	switch (tl_hba->tl_proto_id) {
572 	case SCSI_PROTOCOL_SAS:
573 		return sas_get_fabric_proto_ident(se_tpg);
574 	case SCSI_PROTOCOL_FCP:
575 		return fc_get_fabric_proto_ident(se_tpg);
576 	case SCSI_PROTOCOL_ISCSI:
577 		return iscsi_get_fabric_proto_ident(se_tpg);
578 	default:
579 		pr_err("Unknown tl_proto_id: 0x%02x, using"
580 			" SAS emulation\n", tl_hba->tl_proto_id);
581 		break;
582 	}
583 
584 	return sas_get_fabric_proto_ident(se_tpg);
585 }
586 
587 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
588 {
589 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
590 	/*
591 	 * Return the passed NAA identifier for the SAS Target Port
592 	 */
593 	return &tl_tpg->tl_hba->tl_wwn_address[0];
594 }
595 
596 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
597 {
598 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
599 	/*
600 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
601 	 * to represent the SCSI Target Port.
602 	 */
603 	return tl_tpg->tl_tpgt;
604 }
605 
606 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
607 {
608 	return 1;
609 }
610 
611 static u32 tcm_loop_get_pr_transport_id(
612 	struct se_portal_group *se_tpg,
613 	struct se_node_acl *se_nacl,
614 	struct t10_pr_registration *pr_reg,
615 	int *format_code,
616 	unsigned char *buf)
617 {
618 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
619 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
620 
621 	switch (tl_hba->tl_proto_id) {
622 	case SCSI_PROTOCOL_SAS:
623 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
624 					format_code, buf);
625 	case SCSI_PROTOCOL_FCP:
626 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
627 					format_code, buf);
628 	case SCSI_PROTOCOL_ISCSI:
629 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
630 					format_code, buf);
631 	default:
632 		pr_err("Unknown tl_proto_id: 0x%02x, using"
633 			" SAS emulation\n", tl_hba->tl_proto_id);
634 		break;
635 	}
636 
637 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
638 			format_code, buf);
639 }
640 
641 static u32 tcm_loop_get_pr_transport_id_len(
642 	struct se_portal_group *se_tpg,
643 	struct se_node_acl *se_nacl,
644 	struct t10_pr_registration *pr_reg,
645 	int *format_code)
646 {
647 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
648 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
649 
650 	switch (tl_hba->tl_proto_id) {
651 	case SCSI_PROTOCOL_SAS:
652 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
653 					format_code);
654 	case SCSI_PROTOCOL_FCP:
655 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
656 					format_code);
657 	case SCSI_PROTOCOL_ISCSI:
658 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
659 					format_code);
660 	default:
661 		pr_err("Unknown tl_proto_id: 0x%02x, using"
662 			" SAS emulation\n", tl_hba->tl_proto_id);
663 		break;
664 	}
665 
666 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
667 			format_code);
668 }
669 
670 /*
671  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
672  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
673  */
674 static char *tcm_loop_parse_pr_out_transport_id(
675 	struct se_portal_group *se_tpg,
676 	const char *buf,
677 	u32 *out_tid_len,
678 	char **port_nexus_ptr)
679 {
680 	struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
681 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
682 
683 	switch (tl_hba->tl_proto_id) {
684 	case SCSI_PROTOCOL_SAS:
685 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
686 					port_nexus_ptr);
687 	case SCSI_PROTOCOL_FCP:
688 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
689 					port_nexus_ptr);
690 	case SCSI_PROTOCOL_ISCSI:
691 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
692 					port_nexus_ptr);
693 	default:
694 		pr_err("Unknown tl_proto_id: 0x%02x, using"
695 			" SAS emulation\n", tl_hba->tl_proto_id);
696 		break;
697 	}
698 
699 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
700 			port_nexus_ptr);
701 }
702 
703 /*
704  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
705  * based upon the incoming fabric dependent SCSI Initiator Port
706  */
707 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
708 {
709 	return 1;
710 }
711 
712 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
713 {
714 	return 0;
715 }
716 
717 /*
718  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
719  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
720  */
721 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
722 {
723 	return 0;
724 }
725 
726 /*
727  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
728  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
729  * It has been added here as a nop for target_fabric_tf_ops_check()
730  */
731 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
732 {
733 	return 0;
734 }
735 
736 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
737 	struct se_portal_group *se_tpg)
738 {
739 	struct tcm_loop_nacl *tl_nacl;
740 
741 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
742 	if (!tl_nacl) {
743 		pr_err("Unable to allocate struct tcm_loop_nacl\n");
744 		return NULL;
745 	}
746 
747 	return &tl_nacl->se_node_acl;
748 }
749 
750 static void tcm_loop_tpg_release_fabric_acl(
751 	struct se_portal_group *se_tpg,
752 	struct se_node_acl *se_nacl)
753 {
754 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
755 				struct tcm_loop_nacl, se_node_acl);
756 
757 	kfree(tl_nacl);
758 }
759 
760 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
761 {
762 	return 1;
763 }
764 
765 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
766 {
767 	/*
768 	 * Assume struct scsi_cmnd is not in remove state..
769 	 */
770 	return 0;
771 }
772 
773 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
774 {
775 	/*
776 	 * Assume that TL Nexus is always active
777 	 */
778 	return 1;
779 }
780 
781 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
782 {
783 	return 1;
784 }
785 
786 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
787 {
788 	return;
789 }
790 
791 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
792 {
793 	return 1;
794 }
795 
796 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
797 {
798 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
799 			struct tcm_loop_cmd, tl_se_cmd);
800 
801 	return tl_cmd->sc_cmd_state;
802 }
803 
804 static int tcm_loop_shutdown_session(struct se_session *se_sess)
805 {
806 	return 0;
807 }
808 
809 static void tcm_loop_close_session(struct se_session *se_sess)
810 {
811 	return;
812 };
813 
814 static void tcm_loop_stop_session(
815 	struct se_session *se_sess,
816 	int sess_sleep,
817 	int conn_sleep)
818 {
819 	return;
820 }
821 
822 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
823 {
824 	return;
825 }
826 
827 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
828 {
829 	/*
830 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
831 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
832 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
833 	 * format with transport_generic_map_mem_to_cmd().
834 	 *
835 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
836 	 * object execution queue.
837 	 */
838 	transport_generic_process_write(se_cmd);
839 	return 0;
840 }
841 
842 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
843 {
844 	return 0;
845 }
846 
847 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
848 {
849 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
850 				struct tcm_loop_cmd, tl_se_cmd);
851 	struct scsi_cmnd *sc = tl_cmd->sc;
852 
853 	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
854 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
855 
856 	sc->result = SAM_STAT_GOOD;
857 	set_host_byte(sc, DID_OK);
858 	sc->scsi_done(sc);
859 	return 0;
860 }
861 
862 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
863 {
864 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
865 				struct tcm_loop_cmd, tl_se_cmd);
866 	struct scsi_cmnd *sc = tl_cmd->sc;
867 
868 	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
869 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
870 
871 	if (se_cmd->sense_buffer &&
872 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
873 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
874 
875 		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
876 				SCSI_SENSE_BUFFERSIZE);
877 		sc->result = SAM_STAT_CHECK_CONDITION;
878 		set_driver_byte(sc, DRIVER_SENSE);
879 	} else
880 		sc->result = se_cmd->scsi_status;
881 
882 	set_host_byte(sc, DID_OK);
883 	sc->scsi_done(sc);
884 	return 0;
885 }
886 
887 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
888 {
889 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
890 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
891 	/*
892 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
893 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
894 	 */
895 	atomic_set(&tl_tmr->tmr_complete, 1);
896 	wake_up(&tl_tmr->tl_tmr_wait);
897 	return 0;
898 }
899 
900 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
901 {
902 	return 0;
903 }
904 
905 static u16 tcm_loop_get_fabric_sense_len(void)
906 {
907 	return 0;
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 	tl_nexus = tpg->tl_hba->tl_nexus;
1045 	if (!tl_nexus)
1046 		return -ENODEV;
1047 
1048 	se_sess = tl_nexus->se_sess;
1049 	if (!se_sess)
1050 		return -ENODEV;
1051 
1052 	if (atomic_read(&tpg->tl_tpg_port_count)) {
1053 		pr_err("Unable to remove TCM_Loop I_T Nexus with"
1054 			" active TPG port count: %d\n",
1055 			atomic_read(&tpg->tl_tpg_port_count));
1056 		return -EPERM;
1057 	}
1058 
1059 	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1060 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1061 		tl_nexus->se_sess->se_node_acl->initiatorname);
1062 	/*
1063 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
1064 	 */
1065 	transport_deregister_session(tl_nexus->se_sess);
1066 	tpg->tl_hba->tl_nexus = NULL;
1067 	kfree(tl_nexus);
1068 	return 0;
1069 }
1070 
1071 /* End items for tcm_loop_nexus_cit */
1072 
1073 static ssize_t tcm_loop_tpg_show_nexus(
1074 	struct se_portal_group *se_tpg,
1075 	char *page)
1076 {
1077 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1078 			struct tcm_loop_tpg, tl_se_tpg);
1079 	struct tcm_loop_nexus *tl_nexus;
1080 	ssize_t ret;
1081 
1082 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
1083 	if (!tl_nexus)
1084 		return -ENODEV;
1085 
1086 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1087 		tl_nexus->se_sess->se_node_acl->initiatorname);
1088 
1089 	return ret;
1090 }
1091 
1092 static ssize_t tcm_loop_tpg_store_nexus(
1093 	struct se_portal_group *se_tpg,
1094 	const char *page,
1095 	size_t count)
1096 {
1097 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1098 			struct tcm_loop_tpg, tl_se_tpg);
1099 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1100 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1101 	int ret;
1102 	/*
1103 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1104 	 */
1105 	if (!strncmp(page, "NULL", 4)) {
1106 		ret = tcm_loop_drop_nexus(tl_tpg);
1107 		return (!ret) ? count : ret;
1108 	}
1109 	/*
1110 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1111 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1112 	 * tcm_loop_make_nexus()
1113 	 */
1114 	if (strlen(page) >= TL_WWN_ADDR_LEN) {
1115 		pr_err("Emulated NAA Sas Address: %s, exceeds"
1116 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1117 		return -EINVAL;
1118 	}
1119 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1120 
1121 	ptr = strstr(i_port, "naa.");
1122 	if (ptr) {
1123 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1124 			pr_err("Passed SAS Initiator Port %s does not"
1125 				" match target port protoid: %s\n", i_port,
1126 				tcm_loop_dump_proto_id(tl_hba));
1127 			return -EINVAL;
1128 		}
1129 		port_ptr = &i_port[0];
1130 		goto check_newline;
1131 	}
1132 	ptr = strstr(i_port, "fc.");
1133 	if (ptr) {
1134 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1135 			pr_err("Passed FCP 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[3]; /* Skip over "fc." */
1141 		goto check_newline;
1142 	}
1143 	ptr = strstr(i_port, "iqn.");
1144 	if (ptr) {
1145 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1146 			pr_err("Passed iSCSI 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[0];
1152 		goto check_newline;
1153 	}
1154 	pr_err("Unable to locate prefix for emulated Initiator Port:"
1155 			" %s\n", i_port);
1156 	return -EINVAL;
1157 	/*
1158 	 * Clear any trailing newline for the NAA WWN
1159 	 */
1160 check_newline:
1161 	if (i_port[strlen(i_port)-1] == '\n')
1162 		i_port[strlen(i_port)-1] = '\0';
1163 
1164 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1165 	if (ret < 0)
1166 		return ret;
1167 
1168 	return count;
1169 }
1170 
1171 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1172 
1173 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1174 	&tcm_loop_tpg_nexus.attr,
1175 	NULL,
1176 };
1177 
1178 /* Start items for tcm_loop_naa_cit */
1179 
1180 struct se_portal_group *tcm_loop_make_naa_tpg(
1181 	struct se_wwn *wwn,
1182 	struct config_group *group,
1183 	const char *name)
1184 {
1185 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1186 			struct tcm_loop_hba, tl_hba_wwn);
1187 	struct tcm_loop_tpg *tl_tpg;
1188 	char *tpgt_str, *end_ptr;
1189 	int ret;
1190 	unsigned short int tpgt;
1191 
1192 	tpgt_str = strstr(name, "tpgt_");
1193 	if (!tpgt_str) {
1194 		pr_err("Unable to locate \"tpgt_#\" directory"
1195 				" group\n");
1196 		return ERR_PTR(-EINVAL);
1197 	}
1198 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1199 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1200 
1201 	if (tpgt >= TL_TPGS_PER_HBA) {
1202 		pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1203 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1204 		return ERR_PTR(-EINVAL);
1205 	}
1206 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1207 	tl_tpg->tl_hba = tl_hba;
1208 	tl_tpg->tl_tpgt = tpgt;
1209 	/*
1210 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1211 	 */
1212 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1213 			wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1214 			TRANSPORT_TPG_TYPE_NORMAL);
1215 	if (ret < 0)
1216 		return ERR_PTR(-ENOMEM);
1217 
1218 	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1219 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1220 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1221 
1222 	return &tl_tpg->tl_se_tpg;
1223 }
1224 
1225 void tcm_loop_drop_naa_tpg(
1226 	struct se_portal_group *se_tpg)
1227 {
1228 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1229 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1230 				struct tcm_loop_tpg, tl_se_tpg);
1231 	struct tcm_loop_hba *tl_hba;
1232 	unsigned short tpgt;
1233 
1234 	tl_hba = tl_tpg->tl_hba;
1235 	tpgt = tl_tpg->tl_tpgt;
1236 	/*
1237 	 * Release the I_T Nexus for the Virtual SAS link if present
1238 	 */
1239 	tcm_loop_drop_nexus(tl_tpg);
1240 	/*
1241 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1242 	 */
1243 	core_tpg_deregister(se_tpg);
1244 
1245 	tl_tpg->tl_hba = NULL;
1246 	tl_tpg->tl_tpgt = 0;
1247 
1248 	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1249 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1250 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1251 }
1252 
1253 /* End items for tcm_loop_naa_cit */
1254 
1255 /* Start items for tcm_loop_cit */
1256 
1257 struct se_wwn *tcm_loop_make_scsi_hba(
1258 	struct target_fabric_configfs *tf,
1259 	struct config_group *group,
1260 	const char *name)
1261 {
1262 	struct tcm_loop_hba *tl_hba;
1263 	struct Scsi_Host *sh;
1264 	char *ptr;
1265 	int ret, off = 0;
1266 
1267 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1268 	if (!tl_hba) {
1269 		pr_err("Unable to allocate struct tcm_loop_hba\n");
1270 		return ERR_PTR(-ENOMEM);
1271 	}
1272 	/*
1273 	 * Determine the emulated Protocol Identifier and Target Port Name
1274 	 * based on the incoming configfs directory name.
1275 	 */
1276 	ptr = strstr(name, "naa.");
1277 	if (ptr) {
1278 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1279 		goto check_len;
1280 	}
1281 	ptr = strstr(name, "fc.");
1282 	if (ptr) {
1283 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1284 		off = 3; /* Skip over "fc." */
1285 		goto check_len;
1286 	}
1287 	ptr = strstr(name, "iqn.");
1288 	if (!ptr) {
1289 		pr_err("Unable to locate prefix for emulated Target "
1290 				"Port: %s\n", name);
1291 		ret = -EINVAL;
1292 		goto out;
1293 	}
1294 	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1295 
1296 check_len:
1297 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
1298 		pr_err("Emulated NAA %s Address: %s, exceeds"
1299 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1300 			TL_WWN_ADDR_LEN);
1301 		ret = -EINVAL;
1302 		goto out;
1303 	}
1304 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1305 
1306 	/*
1307 	 * Call device_register(tl_hba->dev) to register the emulated
1308 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1309 	 * device_register() callbacks in tcm_loop_driver_probe()
1310 	 */
1311 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1312 	if (ret)
1313 		goto out;
1314 
1315 	sh = tl_hba->sh;
1316 	tcm_loop_hba_no_cnt++;
1317 	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1318 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1319 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1320 
1321 	return &tl_hba->tl_hba_wwn;
1322 out:
1323 	kfree(tl_hba);
1324 	return ERR_PTR(ret);
1325 }
1326 
1327 void tcm_loop_drop_scsi_hba(
1328 	struct se_wwn *wwn)
1329 {
1330 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1331 				struct tcm_loop_hba, tl_hba_wwn);
1332 
1333 	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1334 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1335 		tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1336 	/*
1337 	 * Call device_unregister() on the original tl_hba->dev.
1338 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1339 	 * release *tl_hba;
1340 	 */
1341 	device_unregister(&tl_hba->dev);
1342 }
1343 
1344 /* Start items for tcm_loop_cit */
1345 static ssize_t tcm_loop_wwn_show_attr_version(
1346 	struct target_fabric_configfs *tf,
1347 	char *page)
1348 {
1349 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1350 }
1351 
1352 TF_WWN_ATTR_RO(tcm_loop, version);
1353 
1354 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1355 	&tcm_loop_wwn_version.attr,
1356 	NULL,
1357 };
1358 
1359 /* End items for tcm_loop_cit */
1360 
1361 static int tcm_loop_register_configfs(void)
1362 {
1363 	struct target_fabric_configfs *fabric;
1364 	struct config_group *tf_cg;
1365 	int ret;
1366 	/*
1367 	 * Set the TCM Loop HBA counter to zero
1368 	 */
1369 	tcm_loop_hba_no_cnt = 0;
1370 	/*
1371 	 * Register the top level struct config_item_type with TCM core
1372 	 */
1373 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1374 	if (IS_ERR(fabric)) {
1375 		pr_err("tcm_loop_register_configfs() failed!\n");
1376 		return PTR_ERR(fabric);
1377 	}
1378 	/*
1379 	 * Setup the fabric API of function pointers used by target_core_mod
1380 	 */
1381 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1382 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1383 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1384 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1385 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1386 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1387 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1388 					&tcm_loop_get_pr_transport_id_len;
1389 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1390 					&tcm_loop_parse_pr_out_transport_id;
1391 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1392 	fabric->tf_ops.tpg_check_demo_mode_cache =
1393 					&tcm_loop_check_demo_mode_cache;
1394 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1395 					&tcm_loop_check_demo_mode_write_protect;
1396 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1397 					&tcm_loop_check_prod_mode_write_protect;
1398 	/*
1399 	 * The TCM loopback fabric module runs in demo-mode to a local
1400 	 * virtual SCSI device, so fabric dependent initator ACLs are
1401 	 * not required.
1402 	 */
1403 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1404 	fabric->tf_ops.tpg_release_fabric_acl =
1405 					&tcm_loop_tpg_release_fabric_acl;
1406 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1407 	/*
1408 	 * Used for setting up remaining TCM resources in process context
1409 	 */
1410 	fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1411 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1412 	fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1413 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1414 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1415 	fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1416 	fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1417 	fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1418 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1419 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1420 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1421 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1422 	/*
1423 	 * Not used for TCM loopback
1424 	 */
1425 	fabric->tf_ops.set_default_node_attributes =
1426 					&tcm_loop_set_default_node_attributes;
1427 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1428 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1429 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1430 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1431 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1432 	fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1433 	fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1434 	fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1435 
1436 	tf_cg = &fabric->tf_group;
1437 	/*
1438 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1439 	 */
1440 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1441 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1442 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1443 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1444 	/*
1445 	 * fabric_post_link() and fabric_pre_unlink() are used for
1446 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1447 	 */
1448 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1449 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1450 	fabric->tf_ops.fabric_make_np = NULL;
1451 	fabric->tf_ops.fabric_drop_np = NULL;
1452 	/*
1453 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1454 	 */
1455 	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1456 	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1457 	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1458 	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1459 	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1460 	/*
1461 	 * Once fabric->tf_ops has been setup, now register the fabric for
1462 	 * use within TCM
1463 	 */
1464 	ret = target_fabric_configfs_register(fabric);
1465 	if (ret < 0) {
1466 		pr_err("target_fabric_configfs_register() for"
1467 				" TCM_Loop failed!\n");
1468 		target_fabric_configfs_free(fabric);
1469 		return -1;
1470 	}
1471 	/*
1472 	 * Setup our local pointer to *fabric.
1473 	 */
1474 	tcm_loop_fabric_configfs = fabric;
1475 	pr_debug("TCM_LOOP[0] - Set fabric ->"
1476 			" tcm_loop_fabric_configfs\n");
1477 	return 0;
1478 }
1479 
1480 static void tcm_loop_deregister_configfs(void)
1481 {
1482 	if (!tcm_loop_fabric_configfs)
1483 		return;
1484 
1485 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1486 	tcm_loop_fabric_configfs = NULL;
1487 	pr_debug("TCM_LOOP[0] - Cleared"
1488 				" tcm_loop_fabric_configfs\n");
1489 }
1490 
1491 static int __init tcm_loop_fabric_init(void)
1492 {
1493 	int ret;
1494 
1495 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1496 				sizeof(struct tcm_loop_cmd),
1497 				__alignof__(struct tcm_loop_cmd),
1498 				0, NULL);
1499 	if (!tcm_loop_cmd_cache) {
1500 		pr_debug("kmem_cache_create() for"
1501 			" tcm_loop_cmd_cache failed\n");
1502 		return -ENOMEM;
1503 	}
1504 
1505 	ret = tcm_loop_alloc_core_bus();
1506 	if (ret)
1507 		return ret;
1508 
1509 	ret = tcm_loop_register_configfs();
1510 	if (ret) {
1511 		tcm_loop_release_core_bus();
1512 		return ret;
1513 	}
1514 
1515 	return 0;
1516 }
1517 
1518 static void __exit tcm_loop_fabric_exit(void)
1519 {
1520 	tcm_loop_deregister_configfs();
1521 	tcm_loop_release_core_bus();
1522 	kmem_cache_destroy(tcm_loop_cmd_cache);
1523 }
1524 
1525 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1526 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1527 MODULE_LICENSE("GPL");
1528 module_init(tcm_loop_fabric_init);
1529 module_exit(tcm_loop_fabric_exit);
1530