xref: /linux/drivers/target/loopback/tcm_loop.c (revision 492c826b9facefa84995f4dea917e301b5ee0884)
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 #include <scsi/libsas.h> /* For TASK_ATTR_* */
35 
36 #include <target/target_core_base.h>
37 #include <target/target_core_transport.h>
38 #include <target/target_core_fabric_ops.h>
39 #include <target/target_core_fabric_configfs.h>
40 #include <target/target_core_fabric_lib.h>
41 #include <target/target_core_configfs.h>
42 #include <target/target_core_device.h>
43 #include <target/target_core_tpg.h>
44 #include <target/target_core_tmr.h>
45 
46 #include "tcm_loop.h"
47 
48 #define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)
49 
50 /* Local pointer to allocated TCM configfs fabric module */
51 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
52 
53 static struct kmem_cache *tcm_loop_cmd_cache;
54 
55 static int tcm_loop_hba_no_cnt;
56 
57 /*
58  * Allocate a tcm_loop cmd descriptor from target_core_mod code
59  *
60  * Can be called from interrupt context in tcm_loop_queuecommand() below
61  */
62 static struct se_cmd *tcm_loop_allocate_core_cmd(
63 	struct tcm_loop_hba *tl_hba,
64 	struct se_portal_group *se_tpg,
65 	struct scsi_cmnd *sc)
66 {
67 	struct se_cmd *se_cmd;
68 	struct se_session *se_sess;
69 	struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
70 	struct tcm_loop_cmd *tl_cmd;
71 	int sam_task_attr;
72 
73 	if (!tl_nexus) {
74 		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
75 				" does not exist\n");
76 		set_host_byte(sc, DID_ERROR);
77 		return NULL;
78 	}
79 	se_sess = tl_nexus->se_sess;
80 
81 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
82 	if (!tl_cmd) {
83 		printk(KERN_ERR "Unable to allocate struct tcm_loop_cmd\n");
84 		set_host_byte(sc, DID_ERROR);
85 		return NULL;
86 	}
87 	se_cmd = &tl_cmd->tl_se_cmd;
88 	/*
89 	 * Save the pointer to struct scsi_cmnd *sc
90 	 */
91 	tl_cmd->sc = sc;
92 	/*
93 	 * Locate the SAM Task Attr from struct scsi_cmnd *
94 	 */
95 	if (sc->device->tagged_supported) {
96 		switch (sc->tag) {
97 		case HEAD_OF_QUEUE_TAG:
98 			sam_task_attr = TASK_ATTR_HOQ;
99 			break;
100 		case ORDERED_QUEUE_TAG:
101 			sam_task_attr = TASK_ATTR_ORDERED;
102 			break;
103 		default:
104 			sam_task_attr = TASK_ATTR_SIMPLE;
105 			break;
106 		}
107 	} else
108 		sam_task_attr = TASK_ATTR_SIMPLE;
109 
110 	/*
111 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
112 	 */
113 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
114 			scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
115 			&tl_cmd->tl_sense_buf[0]);
116 
117 	/*
118 	 * Signal BIDI usage with T_TASK(cmd)->t_tasks_bidi
119 	 */
120 	if (scsi_bidi_cmnd(sc))
121 		T_TASK(se_cmd)->t_tasks_bidi = 1;
122 	/*
123 	 * Locate the struct se_lun pointer and attach it to struct se_cmd
124 	 */
125 	if (transport_get_lun_for_cmd(se_cmd, NULL, tl_cmd->sc->device->lun) < 0) {
126 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
127 		set_host_byte(sc, DID_NO_CONNECT);
128 		return NULL;
129 	}
130 
131 	transport_device_setup_cmd(se_cmd);
132 	return se_cmd;
133 }
134 
135 /*
136  * Called by struct target_core_fabric_ops->new_cmd_map()
137  *
138  * Always called in process context.  A non zero return value
139  * here will signal to handle an exception based on the return code.
140  */
141 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
142 {
143 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
144 				struct tcm_loop_cmd, tl_se_cmd);
145 	struct scsi_cmnd *sc = tl_cmd->sc;
146 	void *mem_ptr, *mem_bidi_ptr = NULL;
147 	u32 sg_no_bidi = 0;
148 	int ret;
149 	/*
150 	 * Allocate the necessary tasks to complete the received CDB+data
151 	 */
152 	ret = transport_generic_allocate_tasks(se_cmd, tl_cmd->sc->cmnd);
153 	if (ret == -1) {
154 		/* Out of Resources */
155 		return PYX_TRANSPORT_LU_COMM_FAILURE;
156 	} else if (ret == -2) {
157 		/*
158 		 * Handle case for SAM_STAT_RESERVATION_CONFLICT
159 		 */
160 		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
161 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
162 		/*
163 		 * Otherwise, return SAM_STAT_CHECK_CONDITION and return
164 		 * sense data.
165 		 */
166 		return PYX_TRANSPORT_USE_SENSE_REASON;
167 	}
168 	/*
169 	 * Setup the struct scatterlist memory from the received
170 	 * struct scsi_cmnd.
171 	 */
172 	if (scsi_sg_count(sc)) {
173 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM;
174 		mem_ptr = (void *)scsi_sglist(sc);
175 		/*
176 		 * For BIDI commands, pass in the extra READ buffer
177 		 * to transport_generic_map_mem_to_cmd() below..
178 		 */
179 		if (T_TASK(se_cmd)->t_tasks_bidi) {
180 			struct scsi_data_buffer *sdb = scsi_in(sc);
181 
182 			mem_bidi_ptr = (void *)sdb->table.sgl;
183 			sg_no_bidi = sdb->table.nents;
184 		}
185 	} else {
186 		/*
187 		 * Used for DMA_NONE
188 		 */
189 		mem_ptr = NULL;
190 	}
191 	/*
192 	 * Map the SG memory into struct se_mem->page linked list using the same
193 	 * physical memory at sg->page_link.
194 	 */
195 	ret = transport_generic_map_mem_to_cmd(se_cmd, mem_ptr,
196 			scsi_sg_count(sc), mem_bidi_ptr, sg_no_bidi);
197 	if (ret < 0)
198 		return PYX_TRANSPORT_LU_COMM_FAILURE;
199 
200 	return 0;
201 }
202 
203 /*
204  * Called from struct target_core_fabric_ops->check_stop_free()
205  */
206 static void tcm_loop_check_stop_free(struct se_cmd *se_cmd)
207 {
208 	/*
209 	 * Do not release struct se_cmd's containing a valid TMR
210 	 * pointer.  These will be released directly in tcm_loop_device_reset()
211 	 * with transport_generic_free_cmd().
212 	 */
213 	if (se_cmd->se_tmr_req)
214 		return;
215 	/*
216 	 * Release the struct se_cmd, which will make a callback to release
217 	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
218 	 */
219 	transport_generic_free_cmd(se_cmd, 0, 1, 0);
220 }
221 
222 /*
223  * Called from struct target_core_fabric_ops->release_cmd_to_pool()
224  */
225 static void tcm_loop_deallocate_core_cmd(struct se_cmd *se_cmd)
226 {
227 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
228 				struct tcm_loop_cmd, tl_se_cmd);
229 
230 	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
231 }
232 
233 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
234 				char **start, off_t offset,
235 				int length, int inout)
236 {
237 	return sprintf(buffer, "tcm_loop_proc_info()\n");
238 }
239 
240 static int tcm_loop_driver_probe(struct device *);
241 static int tcm_loop_driver_remove(struct device *);
242 
243 static int pseudo_lld_bus_match(struct device *dev,
244 				struct device_driver *dev_driver)
245 {
246 	return 1;
247 }
248 
249 static struct bus_type tcm_loop_lld_bus = {
250 	.name			= "tcm_loop_bus",
251 	.match			= pseudo_lld_bus_match,
252 	.probe			= tcm_loop_driver_probe,
253 	.remove			= tcm_loop_driver_remove,
254 };
255 
256 static struct device_driver tcm_loop_driverfs = {
257 	.name			= "tcm_loop",
258 	.bus			= &tcm_loop_lld_bus,
259 };
260 /*
261  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
262  */
263 struct device *tcm_loop_primary;
264 
265 /*
266  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
267  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
268  */
269 static int tcm_loop_change_queue_depth(
270 	struct scsi_device *sdev,
271 	int depth,
272 	int reason)
273 {
274 	switch (reason) {
275 	case SCSI_QDEPTH_DEFAULT:
276 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
277 		break;
278 	case SCSI_QDEPTH_QFULL:
279 		scsi_track_queue_full(sdev, depth);
280 		break;
281 	case SCSI_QDEPTH_RAMP_UP:
282 		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
283 		break;
284 	default:
285 		return -EOPNOTSUPP;
286 	}
287 	return sdev->queue_depth;
288 }
289 
290 /*
291  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
292  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
293  */
294 static int tcm_loop_queuecommand(
295 	struct Scsi_Host *sh,
296 	struct scsi_cmnd *sc)
297 {
298 	struct se_cmd *se_cmd;
299 	struct se_portal_group *se_tpg;
300 	struct tcm_loop_hba *tl_hba;
301 	struct tcm_loop_tpg *tl_tpg;
302 
303 	TL_CDB_DEBUG("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
304 		" scsi_buf_len: %u\n", sc->device->host->host_no,
305 		sc->device->id, sc->device->channel, sc->device->lun,
306 		sc->cmnd[0], scsi_bufflen(sc));
307 	/*
308 	 * Locate the tcm_loop_hba_t pointer
309 	 */
310 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
311 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
312 	se_tpg = &tl_tpg->tl_se_tpg;
313 	/*
314 	 * Determine the SAM Task Attribute and allocate tl_cmd and
315 	 * tl_cmd->tl_se_cmd from TCM infrastructure
316 	 */
317 	se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
318 	if (!se_cmd) {
319 		sc->scsi_done(sc);
320 		return 0;
321 	}
322 	/*
323 	 * Queue up the newly allocated to be processed in TCM thread context.
324 	*/
325 	transport_generic_handle_cdb_map(se_cmd);
326 	return 0;
327 }
328 
329 /*
330  * Called from SCSI EH process context to issue a LUN_RESET TMR
331  * to struct scsi_device
332  */
333 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
334 {
335 	struct se_cmd *se_cmd = NULL;
336 	struct se_portal_group *se_tpg;
337 	struct se_session *se_sess;
338 	struct tcm_loop_cmd *tl_cmd = NULL;
339 	struct tcm_loop_hba *tl_hba;
340 	struct tcm_loop_nexus *tl_nexus;
341 	struct tcm_loop_tmr *tl_tmr = NULL;
342 	struct tcm_loop_tpg *tl_tpg;
343 	int ret = FAILED;
344 	/*
345 	 * Locate the tcm_loop_hba_t pointer
346 	 */
347 	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
348 	/*
349 	 * Locate the tl_nexus and se_sess pointers
350 	 */
351 	tl_nexus = tl_hba->tl_nexus;
352 	if (!tl_nexus) {
353 		printk(KERN_ERR "Unable to perform device reset without"
354 				" active I_T Nexus\n");
355 		return FAILED;
356 	}
357 	se_sess = tl_nexus->se_sess;
358 	/*
359 	 * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
360 	 */
361 	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
362 	se_tpg = &tl_tpg->tl_se_tpg;
363 
364 	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
365 	if (!tl_cmd) {
366 		printk(KERN_ERR "Unable to allocate memory for tl_cmd\n");
367 		return FAILED;
368 	}
369 
370 	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
371 	if (!tl_tmr) {
372 		printk(KERN_ERR "Unable to allocate memory for tl_tmr\n");
373 		goto release;
374 	}
375 	init_waitqueue_head(&tl_tmr->tl_tmr_wait);
376 
377 	se_cmd = &tl_cmd->tl_se_cmd;
378 	/*
379 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
380 	 */
381 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
382 				DMA_NONE, TASK_ATTR_SIMPLE,
383 				&tl_cmd->tl_sense_buf[0]);
384 	/*
385 	 * Allocate the LUN_RESET TMR
386 	 */
387 	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, (void *)tl_tmr,
388 				TMR_LUN_RESET);
389 	if (!se_cmd->se_tmr_req)
390 		goto release;
391 	/*
392 	 * Locate the underlying TCM struct se_lun from sc->device->lun
393 	 */
394 	if (transport_get_lun_for_tmr(se_cmd, sc->device->lun) < 0)
395 		goto release;
396 	/*
397 	 * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
398 	 * to wake us up.
399 	 */
400 	transport_generic_handle_tmr(se_cmd);
401 	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
402 	/*
403 	 * The TMR LUN_RESET has completed, check the response status and
404 	 * then release allocations.
405 	 */
406 	ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
407 		SUCCESS : FAILED;
408 release:
409 	if (se_cmd)
410 		transport_generic_free_cmd(se_cmd, 1, 1, 0);
411 	else
412 		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
413 	kfree(tl_tmr);
414 	return ret;
415 }
416 
417 static int tcm_loop_slave_alloc(struct scsi_device *sd)
418 {
419 	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
420 	return 0;
421 }
422 
423 static int tcm_loop_slave_configure(struct scsi_device *sd)
424 {
425 	return 0;
426 }
427 
428 static struct scsi_host_template tcm_loop_driver_template = {
429 	.proc_info		= tcm_loop_proc_info,
430 	.proc_name		= "tcm_loopback",
431 	.name			= "TCM_Loopback",
432 	.queuecommand		= tcm_loop_queuecommand,
433 	.change_queue_depth	= tcm_loop_change_queue_depth,
434 	.eh_device_reset_handler = tcm_loop_device_reset,
435 	.can_queue		= TL_SCSI_CAN_QUEUE,
436 	.this_id		= -1,
437 	.sg_tablesize		= TL_SCSI_SG_TABLESIZE,
438 	.cmd_per_lun		= TL_SCSI_CMD_PER_LUN,
439 	.max_sectors		= TL_SCSI_MAX_SECTORS,
440 	.use_clustering		= DISABLE_CLUSTERING,
441 	.slave_alloc		= tcm_loop_slave_alloc,
442 	.slave_configure	= tcm_loop_slave_configure,
443 	.module			= THIS_MODULE,
444 };
445 
446 static int tcm_loop_driver_probe(struct device *dev)
447 {
448 	struct tcm_loop_hba *tl_hba;
449 	struct Scsi_Host *sh;
450 	int error;
451 
452 	tl_hba = to_tcm_loop_hba(dev);
453 
454 	sh = scsi_host_alloc(&tcm_loop_driver_template,
455 			sizeof(struct tcm_loop_hba));
456 	if (!sh) {
457 		printk(KERN_ERR "Unable to allocate struct scsi_host\n");
458 		return -ENODEV;
459 	}
460 	tl_hba->sh = sh;
461 
462 	/*
463 	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
464 	 */
465 	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
466 	/*
467 	 * Setup single ID, Channel and LUN for now..
468 	 */
469 	sh->max_id = 2;
470 	sh->max_lun = 0;
471 	sh->max_channel = 0;
472 	sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
473 
474 	error = scsi_add_host(sh, &tl_hba->dev);
475 	if (error) {
476 		printk(KERN_ERR "%s: scsi_add_host failed\n", __func__);
477 		scsi_host_put(sh);
478 		return -ENODEV;
479 	}
480 	return 0;
481 }
482 
483 static int tcm_loop_driver_remove(struct device *dev)
484 {
485 	struct tcm_loop_hba *tl_hba;
486 	struct Scsi_Host *sh;
487 
488 	tl_hba = to_tcm_loop_hba(dev);
489 	sh = tl_hba->sh;
490 
491 	scsi_remove_host(sh);
492 	scsi_host_put(sh);
493 	return 0;
494 }
495 
496 static void tcm_loop_release_adapter(struct device *dev)
497 {
498 	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
499 
500 	kfree(tl_hba);
501 }
502 
503 /*
504  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
505  */
506 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
507 {
508 	int ret;
509 
510 	tl_hba->dev.bus = &tcm_loop_lld_bus;
511 	tl_hba->dev.parent = tcm_loop_primary;
512 	tl_hba->dev.release = &tcm_loop_release_adapter;
513 	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
514 
515 	ret = device_register(&tl_hba->dev);
516 	if (ret) {
517 		printk(KERN_ERR "device_register() failed for"
518 				" tl_hba->dev: %d\n", ret);
519 		return -ENODEV;
520 	}
521 
522 	return 0;
523 }
524 
525 /*
526  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
527  * tcm_loop SCSI bus.
528  */
529 static int tcm_loop_alloc_core_bus(void)
530 {
531 	int ret;
532 
533 	tcm_loop_primary = root_device_register("tcm_loop_0");
534 	if (IS_ERR(tcm_loop_primary)) {
535 		printk(KERN_ERR "Unable to allocate tcm_loop_primary\n");
536 		return PTR_ERR(tcm_loop_primary);
537 	}
538 
539 	ret = bus_register(&tcm_loop_lld_bus);
540 	if (ret) {
541 		printk(KERN_ERR "bus_register() failed for tcm_loop_lld_bus\n");
542 		goto dev_unreg;
543 	}
544 
545 	ret = driver_register(&tcm_loop_driverfs);
546 	if (ret) {
547 		printk(KERN_ERR "driver_register() failed for"
548 				"tcm_loop_driverfs\n");
549 		goto bus_unreg;
550 	}
551 
552 	printk(KERN_INFO "Initialized TCM Loop Core Bus\n");
553 	return ret;
554 
555 bus_unreg:
556 	bus_unregister(&tcm_loop_lld_bus);
557 dev_unreg:
558 	root_device_unregister(tcm_loop_primary);
559 	return ret;
560 }
561 
562 static void tcm_loop_release_core_bus(void)
563 {
564 	driver_unregister(&tcm_loop_driverfs);
565 	bus_unregister(&tcm_loop_lld_bus);
566 	root_device_unregister(tcm_loop_primary);
567 
568 	printk(KERN_INFO "Releasing TCM Loop Core BUS\n");
569 }
570 
571 static char *tcm_loop_get_fabric_name(void)
572 {
573 	return "loopback";
574 }
575 
576 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
577 {
578 	struct tcm_loop_tpg *tl_tpg =
579 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
580 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
581 	/*
582 	 * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
583 	 * time based on the protocol dependent prefix of the passed configfs group.
584 	 *
585 	 * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
586 	 * ProtocolID using target_core_fabric_lib.c symbols.
587 	 */
588 	switch (tl_hba->tl_proto_id) {
589 	case SCSI_PROTOCOL_SAS:
590 		return sas_get_fabric_proto_ident(se_tpg);
591 	case SCSI_PROTOCOL_FCP:
592 		return fc_get_fabric_proto_ident(se_tpg);
593 	case SCSI_PROTOCOL_ISCSI:
594 		return iscsi_get_fabric_proto_ident(se_tpg);
595 	default:
596 		printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
597 			" SAS emulation\n", tl_hba->tl_proto_id);
598 		break;
599 	}
600 
601 	return sas_get_fabric_proto_ident(se_tpg);
602 }
603 
604 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
605 {
606 	struct tcm_loop_tpg *tl_tpg =
607 		(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
608 	/*
609 	 * Return the passed NAA identifier for the SAS Target Port
610 	 */
611 	return &tl_tpg->tl_hba->tl_wwn_address[0];
612 }
613 
614 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
615 {
616 	struct tcm_loop_tpg *tl_tpg =
617 		(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
618 	/*
619 	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
620 	 * to represent the SCSI Target Port.
621 	 */
622 	return tl_tpg->tl_tpgt;
623 }
624 
625 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
626 {
627 	return 1;
628 }
629 
630 static u32 tcm_loop_get_pr_transport_id(
631 	struct se_portal_group *se_tpg,
632 	struct se_node_acl *se_nacl,
633 	struct t10_pr_registration *pr_reg,
634 	int *format_code,
635 	unsigned char *buf)
636 {
637 	struct tcm_loop_tpg *tl_tpg =
638 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
639 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
640 
641 	switch (tl_hba->tl_proto_id) {
642 	case SCSI_PROTOCOL_SAS:
643 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
644 					format_code, buf);
645 	case SCSI_PROTOCOL_FCP:
646 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
647 					format_code, buf);
648 	case SCSI_PROTOCOL_ISCSI:
649 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
650 					format_code, buf);
651 	default:
652 		printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
653 			" SAS emulation\n", tl_hba->tl_proto_id);
654 		break;
655 	}
656 
657 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
658 			format_code, buf);
659 }
660 
661 static u32 tcm_loop_get_pr_transport_id_len(
662 	struct se_portal_group *se_tpg,
663 	struct se_node_acl *se_nacl,
664 	struct t10_pr_registration *pr_reg,
665 	int *format_code)
666 {
667 	struct tcm_loop_tpg *tl_tpg =
668 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
669 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
670 
671 	switch (tl_hba->tl_proto_id) {
672 	case SCSI_PROTOCOL_SAS:
673 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
674 					format_code);
675 	case SCSI_PROTOCOL_FCP:
676 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
677 					format_code);
678 	case SCSI_PROTOCOL_ISCSI:
679 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
680 					format_code);
681 	default:
682 		printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
683 			" SAS emulation\n", tl_hba->tl_proto_id);
684 		break;
685 	}
686 
687 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
688 			format_code);
689 }
690 
691 /*
692  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
693  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
694  */
695 static char *tcm_loop_parse_pr_out_transport_id(
696 	struct se_portal_group *se_tpg,
697 	const char *buf,
698 	u32 *out_tid_len,
699 	char **port_nexus_ptr)
700 {
701 	struct tcm_loop_tpg *tl_tpg =
702 			(struct tcm_loop_tpg *)se_tpg->se_tpg_fabric_ptr;
703 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
704 
705 	switch (tl_hba->tl_proto_id) {
706 	case SCSI_PROTOCOL_SAS:
707 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
708 					port_nexus_ptr);
709 	case SCSI_PROTOCOL_FCP:
710 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
711 					port_nexus_ptr);
712 	case SCSI_PROTOCOL_ISCSI:
713 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
714 					port_nexus_ptr);
715 	default:
716 		printk(KERN_ERR "Unknown tl_proto_id: 0x%02x, using"
717 			" SAS emulation\n", tl_hba->tl_proto_id);
718 		break;
719 	}
720 
721 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
722 			port_nexus_ptr);
723 }
724 
725 /*
726  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
727  * based upon the incoming fabric dependent SCSI Initiator Port
728  */
729 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
730 {
731 	return 1;
732 }
733 
734 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
735 {
736 	return 0;
737 }
738 
739 /*
740  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
741  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
742  */
743 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
744 {
745 	return 0;
746 }
747 
748 /*
749  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
750  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
751  * It has been added here as a nop for target_fabric_tf_ops_check()
752  */
753 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
754 {
755 	return 0;
756 }
757 
758 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
759 	struct se_portal_group *se_tpg)
760 {
761 	struct tcm_loop_nacl *tl_nacl;
762 
763 	tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
764 	if (!tl_nacl) {
765 		printk(KERN_ERR "Unable to allocate struct tcm_loop_nacl\n");
766 		return NULL;
767 	}
768 
769 	return &tl_nacl->se_node_acl;
770 }
771 
772 static void tcm_loop_tpg_release_fabric_acl(
773 	struct se_portal_group *se_tpg,
774 	struct se_node_acl *se_nacl)
775 {
776 	struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
777 				struct tcm_loop_nacl, se_node_acl);
778 
779 	kfree(tl_nacl);
780 }
781 
782 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
783 {
784 	return 1;
785 }
786 
787 static void tcm_loop_new_cmd_failure(struct se_cmd *se_cmd)
788 {
789 	/*
790 	 * Since TCM_loop is already passing struct scatterlist data from
791 	 * struct scsi_cmnd, no more Linux/SCSI failure dependent state need
792 	 * to be handled here.
793 	 */
794 	return;
795 }
796 
797 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
798 {
799 	/*
800 	 * Assume struct scsi_cmnd is not in remove state..
801 	 */
802 	return 0;
803 }
804 
805 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
806 {
807 	/*
808 	 * Assume that TL Nexus is always active
809 	 */
810 	return 1;
811 }
812 
813 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
814 {
815 	return 1;
816 }
817 
818 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
819 {
820 	return;
821 }
822 
823 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
824 {
825 	return 1;
826 }
827 
828 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
829 {
830 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
831 			struct tcm_loop_cmd, tl_se_cmd);
832 
833 	return tl_cmd->sc_cmd_state;
834 }
835 
836 static int tcm_loop_shutdown_session(struct se_session *se_sess)
837 {
838 	return 0;
839 }
840 
841 static void tcm_loop_close_session(struct se_session *se_sess)
842 {
843 	return;
844 };
845 
846 static void tcm_loop_stop_session(
847 	struct se_session *se_sess,
848 	int sess_sleep,
849 	int conn_sleep)
850 {
851 	return;
852 }
853 
854 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
855 {
856 	return;
857 }
858 
859 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
860 {
861 	/*
862 	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
863 	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
864 	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
865 	 * format with transport_generic_map_mem_to_cmd().
866 	 *
867 	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
868 	 * object execution queue.
869 	 */
870 	transport_generic_process_write(se_cmd);
871 	return 0;
872 }
873 
874 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
875 {
876 	return 0;
877 }
878 
879 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
880 {
881 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
882 				struct tcm_loop_cmd, tl_se_cmd);
883 	struct scsi_cmnd *sc = tl_cmd->sc;
884 
885 	TL_CDB_DEBUG("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
886 		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);
887 
888 	sc->result = SAM_STAT_GOOD;
889 	set_host_byte(sc, DID_OK);
890 	sc->scsi_done(sc);
891 	return 0;
892 }
893 
894 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
895 {
896 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
897 				struct tcm_loop_cmd, tl_se_cmd);
898 	struct scsi_cmnd *sc = tl_cmd->sc;
899 
900 	TL_CDB_DEBUG("tcm_loop_queue_status() called for scsi_cmnd: %p"
901 			" cdb: 0x%02x\n", sc, sc->cmnd[0]);
902 
903 	if (se_cmd->sense_buffer &&
904 	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
905 	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
906 
907 		memcpy((void *)sc->sense_buffer, (void *)se_cmd->sense_buffer,
908 				SCSI_SENSE_BUFFERSIZE);
909 		sc->result = SAM_STAT_CHECK_CONDITION;
910 		set_driver_byte(sc, DRIVER_SENSE);
911 	} else
912 		sc->result = se_cmd->scsi_status;
913 
914 	set_host_byte(sc, DID_OK);
915 	sc->scsi_done(sc);
916 	return 0;
917 }
918 
919 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
920 {
921 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
922 	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
923 	/*
924 	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
925 	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
926 	 */
927 	atomic_set(&tl_tmr->tmr_complete, 1);
928 	wake_up(&tl_tmr->tl_tmr_wait);
929 	return 0;
930 }
931 
932 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
933 {
934 	return 0;
935 }
936 
937 static u16 tcm_loop_get_fabric_sense_len(void)
938 {
939 	return 0;
940 }
941 
942 static u64 tcm_loop_pack_lun(unsigned int lun)
943 {
944 	u64 result;
945 
946 	/* LSB of lun into byte 1 big-endian */
947 	result = ((lun & 0xff) << 8);
948 	/* use flat space addressing method */
949 	result |= 0x40 | ((lun >> 8) & 0x3f);
950 
951 	return cpu_to_le64(result);
952 }
953 
954 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
955 {
956 	switch (tl_hba->tl_proto_id) {
957 	case SCSI_PROTOCOL_SAS:
958 		return "SAS";
959 	case SCSI_PROTOCOL_FCP:
960 		return "FCP";
961 	case SCSI_PROTOCOL_ISCSI:
962 		return "iSCSI";
963 	default:
964 		break;
965 	}
966 
967 	return "Unknown";
968 }
969 
970 /* Start items for tcm_loop_port_cit */
971 
972 static int tcm_loop_port_link(
973 	struct se_portal_group *se_tpg,
974 	struct se_lun *lun)
975 {
976 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
977 				struct tcm_loop_tpg, tl_se_tpg);
978 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
979 
980 	atomic_inc(&tl_tpg->tl_tpg_port_count);
981 	smp_mb__after_atomic_inc();
982 	/*
983 	 * Add Linux/SCSI struct scsi_device by HCTL
984 	 */
985 	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
986 
987 	printk(KERN_INFO "TCM_Loop_ConfigFS: Port Link Successful\n");
988 	return 0;
989 }
990 
991 static void tcm_loop_port_unlink(
992 	struct se_portal_group *se_tpg,
993 	struct se_lun *se_lun)
994 {
995 	struct scsi_device *sd;
996 	struct tcm_loop_hba *tl_hba;
997 	struct tcm_loop_tpg *tl_tpg;
998 
999 	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
1000 	tl_hba = tl_tpg->tl_hba;
1001 
1002 	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
1003 				se_lun->unpacked_lun);
1004 	if (!sd) {
1005 		printk(KERN_ERR "Unable to locate struct scsi_device for %d:%d:"
1006 			"%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
1007 		return;
1008 	}
1009 	/*
1010 	 * Remove Linux/SCSI struct scsi_device by HCTL
1011 	 */
1012 	scsi_remove_device(sd);
1013 	scsi_device_put(sd);
1014 
1015 	atomic_dec(&tl_tpg->tl_tpg_port_count);
1016 	smp_mb__after_atomic_dec();
1017 
1018 	printk(KERN_INFO "TCM_Loop_ConfigFS: Port Unlink Successful\n");
1019 }
1020 
1021 /* End items for tcm_loop_port_cit */
1022 
1023 /* Start items for tcm_loop_nexus_cit */
1024 
1025 static int tcm_loop_make_nexus(
1026 	struct tcm_loop_tpg *tl_tpg,
1027 	const char *name)
1028 {
1029 	struct se_portal_group *se_tpg;
1030 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1031 	struct tcm_loop_nexus *tl_nexus;
1032 
1033 	if (tl_tpg->tl_hba->tl_nexus) {
1034 		printk(KERN_INFO "tl_tpg->tl_hba->tl_nexus already exists\n");
1035 		return -EEXIST;
1036 	}
1037 	se_tpg = &tl_tpg->tl_se_tpg;
1038 
1039 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
1040 	if (!tl_nexus) {
1041 		printk(KERN_ERR "Unable to allocate struct tcm_loop_nexus\n");
1042 		return -ENOMEM;
1043 	}
1044 	/*
1045 	 * Initialize the struct se_session pointer
1046 	 */
1047 	tl_nexus->se_sess = transport_init_session();
1048 	if (!tl_nexus->se_sess)
1049 		goto out;
1050 	/*
1051 	 * Since we are running in 'demo mode' this call with generate a
1052 	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1053 	 * Initiator port name of the passed configfs group 'name'.
1054 	 */
1055 	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1056 				se_tpg, (unsigned char *)name);
1057 	if (!tl_nexus->se_sess->se_node_acl) {
1058 		transport_free_session(tl_nexus->se_sess);
1059 		goto out;
1060 	}
1061 	/*
1062 	 * Now, register the SAS I_T Nexus as active with the call to
1063 	 * transport_register_session()
1064 	 */
1065 	__transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1066 			tl_nexus->se_sess, (void *)tl_nexus);
1067 	tl_tpg->tl_hba->tl_nexus = tl_nexus;
1068 	printk(KERN_INFO "TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1069 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1070 		name);
1071 	return 0;
1072 
1073 out:
1074 	kfree(tl_nexus);
1075 	return -ENOMEM;
1076 }
1077 
1078 static int tcm_loop_drop_nexus(
1079 	struct tcm_loop_tpg *tpg)
1080 {
1081 	struct se_session *se_sess;
1082 	struct tcm_loop_nexus *tl_nexus;
1083 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1084 
1085 	tl_nexus = tpg->tl_hba->tl_nexus;
1086 	if (!tl_nexus)
1087 		return -ENODEV;
1088 
1089 	se_sess = tl_nexus->se_sess;
1090 	if (!se_sess)
1091 		return -ENODEV;
1092 
1093 	if (atomic_read(&tpg->tl_tpg_port_count)) {
1094 		printk(KERN_ERR "Unable to remove TCM_Loop I_T Nexus with"
1095 			" active TPG port count: %d\n",
1096 			atomic_read(&tpg->tl_tpg_port_count));
1097 		return -EPERM;
1098 	}
1099 
1100 	printk(KERN_INFO "TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1101 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1102 		tl_nexus->se_sess->se_node_acl->initiatorname);
1103 	/*
1104 	 * Release the SCSI I_T Nexus to the emulated SAS Target Port
1105 	 */
1106 	transport_deregister_session(tl_nexus->se_sess);
1107 	tpg->tl_hba->tl_nexus = NULL;
1108 	kfree(tl_nexus);
1109 	return 0;
1110 }
1111 
1112 /* End items for tcm_loop_nexus_cit */
1113 
1114 static ssize_t tcm_loop_tpg_show_nexus(
1115 	struct se_portal_group *se_tpg,
1116 	char *page)
1117 {
1118 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1119 			struct tcm_loop_tpg, tl_se_tpg);
1120 	struct tcm_loop_nexus *tl_nexus;
1121 	ssize_t ret;
1122 
1123 	tl_nexus = tl_tpg->tl_hba->tl_nexus;
1124 	if (!tl_nexus)
1125 		return -ENODEV;
1126 
1127 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1128 		tl_nexus->se_sess->se_node_acl->initiatorname);
1129 
1130 	return ret;
1131 }
1132 
1133 static ssize_t tcm_loop_tpg_store_nexus(
1134 	struct se_portal_group *se_tpg,
1135 	const char *page,
1136 	size_t count)
1137 {
1138 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1139 			struct tcm_loop_tpg, tl_se_tpg);
1140 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1141 	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1142 	int ret;
1143 	/*
1144 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1145 	 */
1146 	if (!strncmp(page, "NULL", 4)) {
1147 		ret = tcm_loop_drop_nexus(tl_tpg);
1148 		return (!ret) ? count : ret;
1149 	}
1150 	/*
1151 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1152 	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1153 	 * tcm_loop_make_nexus()
1154 	 */
1155 	if (strlen(page) > TL_WWN_ADDR_LEN) {
1156 		printk(KERN_ERR "Emulated NAA Sas Address: %s, exceeds"
1157 				" max: %d\n", page, TL_WWN_ADDR_LEN);
1158 		return -EINVAL;
1159 	}
1160 	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1161 
1162 	ptr = strstr(i_port, "naa.");
1163 	if (ptr) {
1164 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1165 			printk(KERN_ERR "Passed SAS Initiator Port %s does not"
1166 				" match target port protoid: %s\n", i_port,
1167 				tcm_loop_dump_proto_id(tl_hba));
1168 			return -EINVAL;
1169 		}
1170 		port_ptr = &i_port[0];
1171 		goto check_newline;
1172 	}
1173 	ptr = strstr(i_port, "fc.");
1174 	if (ptr) {
1175 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1176 			printk(KERN_ERR "Passed FCP Initiator Port %s does not"
1177 				" match target port protoid: %s\n", i_port,
1178 				tcm_loop_dump_proto_id(tl_hba));
1179 			return -EINVAL;
1180 		}
1181 		port_ptr = &i_port[3]; /* Skip over "fc." */
1182 		goto check_newline;
1183 	}
1184 	ptr = strstr(i_port, "iqn.");
1185 	if (ptr) {
1186 		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1187 			printk(KERN_ERR "Passed iSCSI Initiator Port %s does not"
1188 				" match target port protoid: %s\n", i_port,
1189 				tcm_loop_dump_proto_id(tl_hba));
1190 			return -EINVAL;
1191 		}
1192 		port_ptr = &i_port[0];
1193 		goto check_newline;
1194 	}
1195 	printk(KERN_ERR "Unable to locate prefix for emulated Initiator Port:"
1196 			" %s\n", i_port);
1197 	return -EINVAL;
1198 	/*
1199 	 * Clear any trailing newline for the NAA WWN
1200 	 */
1201 check_newline:
1202 	if (i_port[strlen(i_port)-1] == '\n')
1203 		i_port[strlen(i_port)-1] = '\0';
1204 
1205 	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1206 	if (ret < 0)
1207 		return ret;
1208 
1209 	return count;
1210 }
1211 
1212 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1213 
1214 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1215 	&tcm_loop_tpg_nexus.attr,
1216 	NULL,
1217 };
1218 
1219 /* Start items for tcm_loop_naa_cit */
1220 
1221 struct se_portal_group *tcm_loop_make_naa_tpg(
1222 	struct se_wwn *wwn,
1223 	struct config_group *group,
1224 	const char *name)
1225 {
1226 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1227 			struct tcm_loop_hba, tl_hba_wwn);
1228 	struct tcm_loop_tpg *tl_tpg;
1229 	char *tpgt_str, *end_ptr;
1230 	int ret;
1231 	unsigned short int tpgt;
1232 
1233 	tpgt_str = strstr(name, "tpgt_");
1234 	if (!tpgt_str) {
1235 		printk(KERN_ERR "Unable to locate \"tpgt_#\" directory"
1236 				" group\n");
1237 		return ERR_PTR(-EINVAL);
1238 	}
1239 	tpgt_str += 5; /* Skip ahead of "tpgt_" */
1240 	tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1241 
1242 	if (tpgt > TL_TPGS_PER_HBA) {
1243 		printk(KERN_ERR "Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1244 				" %u\n", tpgt, TL_TPGS_PER_HBA);
1245 		return ERR_PTR(-EINVAL);
1246 	}
1247 	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1248 	tl_tpg->tl_hba = tl_hba;
1249 	tl_tpg->tl_tpgt = tpgt;
1250 	/*
1251 	 * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1252 	 */
1253 	ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1254 			wwn, &tl_tpg->tl_se_tpg, (void *)tl_tpg,
1255 			TRANSPORT_TPG_TYPE_NORMAL);
1256 	if (ret < 0)
1257 		return ERR_PTR(-ENOMEM);
1258 
1259 	printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated 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 	return &tl_tpg->tl_se_tpg;
1264 }
1265 
1266 void tcm_loop_drop_naa_tpg(
1267 	struct se_portal_group *se_tpg)
1268 {
1269 	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1270 	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1271 				struct tcm_loop_tpg, tl_se_tpg);
1272 	struct tcm_loop_hba *tl_hba;
1273 	unsigned short tpgt;
1274 
1275 	tl_hba = tl_tpg->tl_hba;
1276 	tpgt = tl_tpg->tl_tpgt;
1277 	/*
1278 	 * Release the I_T Nexus for the Virtual SAS link if present
1279 	 */
1280 	tcm_loop_drop_nexus(tl_tpg);
1281 	/*
1282 	 * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1283 	 */
1284 	core_tpg_deregister(se_tpg);
1285 
1286 	printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated Emulated %s"
1287 		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1288 		config_item_name(&wwn->wwn_group.cg_item), tpgt);
1289 }
1290 
1291 /* End items for tcm_loop_naa_cit */
1292 
1293 /* Start items for tcm_loop_cit */
1294 
1295 struct se_wwn *tcm_loop_make_scsi_hba(
1296 	struct target_fabric_configfs *tf,
1297 	struct config_group *group,
1298 	const char *name)
1299 {
1300 	struct tcm_loop_hba *tl_hba;
1301 	struct Scsi_Host *sh;
1302 	char *ptr;
1303 	int ret, off = 0;
1304 
1305 	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1306 	if (!tl_hba) {
1307 		printk(KERN_ERR "Unable to allocate struct tcm_loop_hba\n");
1308 		return ERR_PTR(-ENOMEM);
1309 	}
1310 	/*
1311 	 * Determine the emulated Protocol Identifier and Target Port Name
1312 	 * based on the incoming configfs directory name.
1313 	 */
1314 	ptr = strstr(name, "naa.");
1315 	if (ptr) {
1316 		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1317 		goto check_len;
1318 	}
1319 	ptr = strstr(name, "fc.");
1320 	if (ptr) {
1321 		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1322 		off = 3; /* Skip over "fc." */
1323 		goto check_len;
1324 	}
1325 	ptr = strstr(name, "iqn.");
1326 	if (ptr) {
1327 		tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1328 		goto check_len;
1329 	}
1330 
1331 	printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
1332 			" %s\n", name);
1333 	return ERR_PTR(-EINVAL);
1334 
1335 check_len:
1336 	if (strlen(name) > TL_WWN_ADDR_LEN) {
1337 		printk(KERN_ERR "Emulated NAA %s Address: %s, exceeds"
1338 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1339 			TL_WWN_ADDR_LEN);
1340 		kfree(tl_hba);
1341 		return ERR_PTR(-EINVAL);
1342 	}
1343 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1344 
1345 	/*
1346 	 * Call device_register(tl_hba->dev) to register the emulated
1347 	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1348 	 * device_register() callbacks in tcm_loop_driver_probe()
1349 	 */
1350 	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1351 	if (ret)
1352 		goto out;
1353 
1354 	sh = tl_hba->sh;
1355 	tcm_loop_hba_no_cnt++;
1356 	printk(KERN_INFO "TCM_Loop_ConfigFS: Allocated emulated Target"
1357 		" %s Address: %s at Linux/SCSI Host ID: %d\n",
1358 		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1359 
1360 	return &tl_hba->tl_hba_wwn;
1361 out:
1362 	kfree(tl_hba);
1363 	return ERR_PTR(ret);
1364 }
1365 
1366 void tcm_loop_drop_scsi_hba(
1367 	struct se_wwn *wwn)
1368 {
1369 	struct tcm_loop_hba *tl_hba = container_of(wwn,
1370 				struct tcm_loop_hba, tl_hba_wwn);
1371 	int host_no = tl_hba->sh->host_no;
1372 	/*
1373 	 * Call device_unregister() on the original tl_hba->dev.
1374 	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1375 	 * release *tl_hba;
1376 	 */
1377 	device_unregister(&tl_hba->dev);
1378 
1379 	printk(KERN_INFO "TCM_Loop_ConfigFS: Deallocated emulated Target"
1380 		" SAS Address: %s at Linux/SCSI Host ID: %d\n",
1381 		config_item_name(&wwn->wwn_group.cg_item), host_no);
1382 }
1383 
1384 /* Start items for tcm_loop_cit */
1385 static ssize_t tcm_loop_wwn_show_attr_version(
1386 	struct target_fabric_configfs *tf,
1387 	char *page)
1388 {
1389 	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1390 }
1391 
1392 TF_WWN_ATTR_RO(tcm_loop, version);
1393 
1394 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1395 	&tcm_loop_wwn_version.attr,
1396 	NULL,
1397 };
1398 
1399 /* End items for tcm_loop_cit */
1400 
1401 static int tcm_loop_register_configfs(void)
1402 {
1403 	struct target_fabric_configfs *fabric;
1404 	struct config_group *tf_cg;
1405 	int ret;
1406 	/*
1407 	 * Set the TCM Loop HBA counter to zero
1408 	 */
1409 	tcm_loop_hba_no_cnt = 0;
1410 	/*
1411 	 * Register the top level struct config_item_type with TCM core
1412 	 */
1413 	fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1414 	if (!fabric) {
1415 		printk(KERN_ERR "tcm_loop_register_configfs() failed!\n");
1416 		return -1;
1417 	}
1418 	/*
1419 	 * Setup the fabric API of function pointers used by target_core_mod
1420 	 */
1421 	fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1422 	fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1423 	fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1424 	fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1425 	fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1426 	fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1427 	fabric->tf_ops.tpg_get_pr_transport_id_len =
1428 					&tcm_loop_get_pr_transport_id_len;
1429 	fabric->tf_ops.tpg_parse_pr_out_transport_id =
1430 					&tcm_loop_parse_pr_out_transport_id;
1431 	fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1432 	fabric->tf_ops.tpg_check_demo_mode_cache =
1433 					&tcm_loop_check_demo_mode_cache;
1434 	fabric->tf_ops.tpg_check_demo_mode_write_protect =
1435 					&tcm_loop_check_demo_mode_write_protect;
1436 	fabric->tf_ops.tpg_check_prod_mode_write_protect =
1437 					&tcm_loop_check_prod_mode_write_protect;
1438 	/*
1439 	 * The TCM loopback fabric module runs in demo-mode to a local
1440 	 * virtual SCSI device, so fabric dependent initator ACLs are
1441 	 * not required.
1442 	 */
1443 	fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1444 	fabric->tf_ops.tpg_release_fabric_acl =
1445 					&tcm_loop_tpg_release_fabric_acl;
1446 	fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1447 	/*
1448 	 * Since tcm_loop is mapping physical memory from Linux/SCSI
1449 	 * struct scatterlist arrays for each struct scsi_cmnd I/O,
1450 	 * we do not need TCM to allocate a iovec array for
1451 	 * virtual memory address mappings
1452 	 */
1453 	fabric->tf_ops.alloc_cmd_iovecs = NULL;
1454 	/*
1455 	 * Used for setting up remaining TCM resources in process context
1456 	 */
1457 	fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1458 	fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1459 	fabric->tf_ops.release_cmd_to_pool = &tcm_loop_deallocate_core_cmd;
1460 	fabric->tf_ops.release_cmd_direct = &tcm_loop_deallocate_core_cmd;
1461 	fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1462 	fabric->tf_ops.close_session = &tcm_loop_close_session;
1463 	fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1464 	fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1465 	fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1466 	fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1467 	fabric->tf_ops.sess_get_initiator_sid = NULL;
1468 	fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1469 	fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1470 	/*
1471 	 * Not used for TCM loopback
1472 	 */
1473 	fabric->tf_ops.set_default_node_attributes =
1474 					&tcm_loop_set_default_node_attributes;
1475 	fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1476 	fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1477 	fabric->tf_ops.new_cmd_failure = &tcm_loop_new_cmd_failure;
1478 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1479 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1480 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1481 	fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1482 	fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1483 	fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1484 	fabric->tf_ops.pack_lun = &tcm_loop_pack_lun;
1485 
1486 	tf_cg = &fabric->tf_group;
1487 	/*
1488 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c
1489 	 */
1490 	fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1491 	fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1492 	fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1493 	fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1494 	/*
1495 	 * fabric_post_link() and fabric_pre_unlink() are used for
1496 	 * registration and release of TCM Loop Virtual SCSI LUNs.
1497 	 */
1498 	fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1499 	fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1500 	fabric->tf_ops.fabric_make_np = NULL;
1501 	fabric->tf_ops.fabric_drop_np = NULL;
1502 	/*
1503 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
1504 	 */
1505 	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1506 	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1507 	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1508 	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1509 	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1510 	/*
1511 	 * Once fabric->tf_ops has been setup, now register the fabric for
1512 	 * use within TCM
1513 	 */
1514 	ret = target_fabric_configfs_register(fabric);
1515 	if (ret < 0) {
1516 		printk(KERN_ERR "target_fabric_configfs_register() for"
1517 				" TCM_Loop failed!\n");
1518 		target_fabric_configfs_free(fabric);
1519 		return -1;
1520 	}
1521 	/*
1522 	 * Setup our local pointer to *fabric.
1523 	 */
1524 	tcm_loop_fabric_configfs = fabric;
1525 	printk(KERN_INFO "TCM_LOOP[0] - Set fabric ->"
1526 			" tcm_loop_fabric_configfs\n");
1527 	return 0;
1528 }
1529 
1530 static void tcm_loop_deregister_configfs(void)
1531 {
1532 	if (!tcm_loop_fabric_configfs)
1533 		return;
1534 
1535 	target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1536 	tcm_loop_fabric_configfs = NULL;
1537 	printk(KERN_INFO "TCM_LOOP[0] - Cleared"
1538 				" tcm_loop_fabric_configfs\n");
1539 }
1540 
1541 static int __init tcm_loop_fabric_init(void)
1542 {
1543 	int ret;
1544 
1545 	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1546 				sizeof(struct tcm_loop_cmd),
1547 				__alignof__(struct tcm_loop_cmd),
1548 				0, NULL);
1549 	if (!tcm_loop_cmd_cache) {
1550 		printk(KERN_ERR "kmem_cache_create() for"
1551 			" tcm_loop_cmd_cache failed\n");
1552 		return -ENOMEM;
1553 	}
1554 
1555 	ret = tcm_loop_alloc_core_bus();
1556 	if (ret)
1557 		return ret;
1558 
1559 	ret = tcm_loop_register_configfs();
1560 	if (ret) {
1561 		tcm_loop_release_core_bus();
1562 		return ret;
1563 	}
1564 
1565 	return 0;
1566 }
1567 
1568 static void __exit tcm_loop_fabric_exit(void)
1569 {
1570 	tcm_loop_deregister_configfs();
1571 	tcm_loop_release_core_bus();
1572 	kmem_cache_destroy(tcm_loop_cmd_cache);
1573 }
1574 
1575 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1576 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1577 MODULE_LICENSE("GPL");
1578 module_init(tcm_loop_fabric_init);
1579 module_exit(tcm_loop_fabric_exit);
1580