1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_pscsi.c
4  *
5  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
6  *
7  * (c) Copyright 2003-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  ******************************************************************************/
12 
13 #include <linux/string.h>
14 #include <linux/parser.h>
15 #include <linux/timer.h>
16 #include <linux/blkdev.h>
17 #include <linux/blk_types.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/genhd.h>
21 #include <linux/cdrom.h>
22 #include <linux/ratelimit.h>
23 #include <linux/module.h>
24 #include <asm/unaligned.h>
25 
26 #include <scsi/scsi_device.h>
27 #include <scsi/scsi_host.h>
28 #include <scsi/scsi_tcq.h>
29 
30 #include <target/target_core_base.h>
31 #include <target/target_core_backend.h>
32 
33 #include "target_core_alua.h"
34 #include "target_core_internal.h"
35 #include "target_core_pscsi.h"
36 
37 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
38 {
39 	return container_of(dev, struct pscsi_dev_virt, dev);
40 }
41 
42 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
43 static void pscsi_req_done(struct request *, blk_status_t);
44 
45 /*	pscsi_attach_hba():
46  *
47  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
48  *	from the passed SCSI Host ID.
49  */
50 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
51 {
52 	struct pscsi_hba_virt *phv;
53 
54 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
55 	if (!phv) {
56 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
57 		return -ENOMEM;
58 	}
59 	phv->phv_host_id = host_id;
60 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
61 
62 	hba->hba_ptr = phv;
63 
64 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
65 		" Generic Target Core Stack %s\n", hba->hba_id,
66 		PSCSI_VERSION, TARGET_CORE_VERSION);
67 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
68 	       hba->hba_id);
69 
70 	return 0;
71 }
72 
73 static void pscsi_detach_hba(struct se_hba *hba)
74 {
75 	struct pscsi_hba_virt *phv = hba->hba_ptr;
76 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
77 
78 	if (scsi_host) {
79 		scsi_host_put(scsi_host);
80 
81 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
82 			" Generic Target Core\n", hba->hba_id,
83 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
84 			"Unknown");
85 	} else
86 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
87 			" from Generic Target Core\n", hba->hba_id);
88 
89 	kfree(phv);
90 	hba->hba_ptr = NULL;
91 }
92 
93 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
94 {
95 	struct pscsi_hba_virt *phv = hba->hba_ptr;
96 	struct Scsi_Host *sh = phv->phv_lld_host;
97 	/*
98 	 * Release the struct Scsi_Host
99 	 */
100 	if (!mode_flag) {
101 		if (!sh)
102 			return 0;
103 
104 		phv->phv_lld_host = NULL;
105 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
106 
107 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
108 			" %s\n", hba->hba_id, (sh->hostt->name) ?
109 			(sh->hostt->name) : "Unknown");
110 
111 		scsi_host_put(sh);
112 		return 0;
113 	}
114 	/*
115 	 * Otherwise, locate struct Scsi_Host from the original passed
116 	 * pSCSI Host ID and enable for phba mode
117 	 */
118 	sh = scsi_host_lookup(phv->phv_host_id);
119 	if (!sh) {
120 		pr_err("pSCSI: Unable to locate SCSI Host for"
121 			" phv_host_id: %d\n", phv->phv_host_id);
122 		return -EINVAL;
123 	}
124 
125 	phv->phv_lld_host = sh;
126 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
127 
128 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
129 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
130 
131 	return 1;
132 }
133 
134 static void pscsi_tape_read_blocksize(struct se_device *dev,
135 		struct scsi_device *sdev)
136 {
137 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
138 	int ret;
139 
140 	buf = kzalloc(12, GFP_KERNEL);
141 	if (!buf)
142 		goto out_free;
143 
144 	memset(cdb, 0, MAX_COMMAND_SIZE);
145 	cdb[0] = MODE_SENSE;
146 	cdb[4] = 0x0c; /* 12 bytes */
147 
148 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
149 			HZ, 1, NULL);
150 	if (ret)
151 		goto out_free;
152 
153 	/*
154 	 * If MODE_SENSE still returns zero, set the default value to 1024.
155 	 */
156 	sdev->sector_size = get_unaligned_be24(&buf[9]);
157 out_free:
158 	if (!sdev->sector_size)
159 		sdev->sector_size = 1024;
160 
161 	kfree(buf);
162 }
163 
164 static void
165 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
166 {
167 	if (sdev->inquiry_len < INQUIRY_LEN)
168 		return;
169 	/*
170 	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
171 	 */
172 	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
173 	snprintf(wwn->vendor, sizeof(wwn->vendor),
174 		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
175 	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
176 	snprintf(wwn->model, sizeof(wwn->model),
177 		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
178 	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
179 	snprintf(wwn->revision, sizeof(wwn->revision),
180 		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
181 }
182 
183 static int
184 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
185 {
186 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
187 	int ret;
188 
189 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
190 	if (!buf)
191 		return -ENOMEM;
192 
193 	memset(cdb, 0, MAX_COMMAND_SIZE);
194 	cdb[0] = INQUIRY;
195 	cdb[1] = 0x01; /* Query VPD */
196 	cdb[2] = 0x80; /* Unit Serial Number */
197 	put_unaligned_be16(INQUIRY_VPD_SERIAL_LEN, &cdb[3]);
198 
199 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
200 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
201 	if (ret)
202 		goto out_free;
203 
204 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
205 
206 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
207 
208 	kfree(buf);
209 	return 0;
210 
211 out_free:
212 	kfree(buf);
213 	return -EPERM;
214 }
215 
216 static void
217 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
218 		struct t10_wwn *wwn)
219 {
220 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
221 	int ident_len, page_len, off = 4, ret;
222 	struct t10_vpd *vpd;
223 
224 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
225 	if (!buf)
226 		return;
227 
228 	memset(cdb, 0, MAX_COMMAND_SIZE);
229 	cdb[0] = INQUIRY;
230 	cdb[1] = 0x01; /* Query VPD */
231 	cdb[2] = 0x83; /* Device Identifier */
232 	put_unaligned_be16(INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, &cdb[3]);
233 
234 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
235 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
236 			      NULL, HZ, 1, NULL);
237 	if (ret)
238 		goto out;
239 
240 	page_len = get_unaligned_be16(&buf[2]);
241 	while (page_len > 0) {
242 		/* Grab a pointer to the Identification descriptor */
243 		page_83 = &buf[off];
244 		ident_len = page_83[3];
245 		if (!ident_len) {
246 			pr_err("page_83[3]: identifier"
247 					" length zero!\n");
248 			break;
249 		}
250 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
251 
252 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
253 		if (!vpd) {
254 			pr_err("Unable to allocate memory for"
255 					" struct t10_vpd\n");
256 			goto out;
257 		}
258 		INIT_LIST_HEAD(&vpd->vpd_list);
259 
260 		transport_set_vpd_proto_id(vpd, page_83);
261 		transport_set_vpd_assoc(vpd, page_83);
262 
263 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
264 			off += (ident_len + 4);
265 			page_len -= (ident_len + 4);
266 			kfree(vpd);
267 			continue;
268 		}
269 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
270 			off += (ident_len + 4);
271 			page_len -= (ident_len + 4);
272 			kfree(vpd);
273 			continue;
274 		}
275 
276 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
277 		off += (ident_len + 4);
278 		page_len -= (ident_len + 4);
279 	}
280 
281 out:
282 	kfree(buf);
283 }
284 
285 static int pscsi_add_device_to_list(struct se_device *dev,
286 		struct scsi_device *sd)
287 {
288 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
289 	struct request_queue *q = sd->request_queue;
290 
291 	pdv->pdv_sd = sd;
292 
293 	if (!sd->queue_depth) {
294 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
295 
296 		pr_err("Set broken SCSI Device %d:%d:%llu"
297 			" queue_depth to %d\n", sd->channel, sd->id,
298 				sd->lun, sd->queue_depth);
299 	}
300 
301 	dev->dev_attrib.hw_block_size =
302 		min_not_zero((int)sd->sector_size, 512);
303 	dev->dev_attrib.hw_max_sectors =
304 		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
305 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
306 
307 	/*
308 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
309 	 */
310 	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
311 
312 	/*
313 	 * Locate VPD WWN Information used for various purposes within
314 	 * the Storage Engine.
315 	 */
316 	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
317 		/*
318 		 * If VPD Unit Serial returned GOOD status, try
319 		 * VPD Device Identification page (0x83).
320 		 */
321 		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
322 	}
323 
324 	/*
325 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
326 	 */
327 	if (sd->type == TYPE_TAPE) {
328 		pscsi_tape_read_blocksize(dev, sd);
329 		dev->dev_attrib.hw_block_size = sd->sector_size;
330 	}
331 	return 0;
332 }
333 
334 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
335 		const char *name)
336 {
337 	struct pscsi_dev_virt *pdv;
338 
339 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
340 	if (!pdv) {
341 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
342 		return NULL;
343 	}
344 
345 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
346 	return &pdv->dev;
347 }
348 
349 /*
350  * Called with struct Scsi_Host->host_lock called.
351  */
352 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
353 	__releases(sh->host_lock)
354 {
355 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
356 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
357 	struct Scsi_Host *sh = sd->host;
358 	struct block_device *bd;
359 	int ret;
360 
361 	if (scsi_device_get(sd)) {
362 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
363 			sh->host_no, sd->channel, sd->id, sd->lun);
364 		spin_unlock_irq(sh->host_lock);
365 		return -EIO;
366 	}
367 	spin_unlock_irq(sh->host_lock);
368 	/*
369 	 * Claim exclusive struct block_device access to struct scsi_device
370 	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
371 	 */
372 	bd = blkdev_get_by_path(dev->udev_path,
373 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
374 	if (IS_ERR(bd)) {
375 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
376 		scsi_device_put(sd);
377 		return PTR_ERR(bd);
378 	}
379 	pdv->pdv_bd = bd;
380 
381 	ret = pscsi_add_device_to_list(dev, sd);
382 	if (ret) {
383 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
384 		scsi_device_put(sd);
385 		return ret;
386 	}
387 
388 	pr_debug("CORE_PSCSI[%d] - Added TYPE_%s for %d:%d:%d:%llu\n",
389 		phv->phv_host_id, sd->type == TYPE_DISK ? "DISK" : "ZBC",
390 		sh->host_no, sd->channel, sd->id, sd->lun);
391 	return 0;
392 }
393 
394 /*
395  * Called with struct Scsi_Host->host_lock called.
396  */
397 static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
398 	__releases(sh->host_lock)
399 {
400 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
401 	struct Scsi_Host *sh = sd->host;
402 	int ret;
403 
404 	if (scsi_device_get(sd)) {
405 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
406 			sh->host_no, sd->channel, sd->id, sd->lun);
407 		spin_unlock_irq(sh->host_lock);
408 		return -EIO;
409 	}
410 	spin_unlock_irq(sh->host_lock);
411 
412 	ret = pscsi_add_device_to_list(dev, sd);
413 	if (ret) {
414 		scsi_device_put(sd);
415 		return ret;
416 	}
417 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
418 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
419 		sd->channel, sd->id, sd->lun);
420 
421 	return 0;
422 }
423 
424 static int pscsi_configure_device(struct se_device *dev)
425 {
426 	struct se_hba *hba = dev->se_hba;
427 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
428 	struct scsi_device *sd;
429 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
430 	struct Scsi_Host *sh = phv->phv_lld_host;
431 	int legacy_mode_enable = 0;
432 	int ret;
433 
434 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
435 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
436 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
437 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
438 			" scsi_lun_id= parameters\n");
439 		return -EINVAL;
440 	}
441 
442 	/*
443 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
444 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
445 	 */
446 	if (!sh) {
447 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
448 			pr_err("pSCSI: Unable to locate struct"
449 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
450 			return -ENODEV;
451 		}
452 		/*
453 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
454 		 * reference, we enforce that udev_path has been set
455 		 */
456 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
457 			pr_err("pSCSI: udev_path attribute has not"
458 				" been set before ENABLE=1\n");
459 			return -EINVAL;
460 		}
461 		/*
462 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
463 		 * use the original TCM hba ID to reference Linux/SCSI Host No
464 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
465 		 */
466 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
467 			if (hba->dev_count) {
468 				pr_err("pSCSI: Unable to set hba_mode"
469 					" with active devices\n");
470 				return -EEXIST;
471 			}
472 
473 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
474 				return -ENODEV;
475 
476 			legacy_mode_enable = 1;
477 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
478 			sh = phv->phv_lld_host;
479 		} else {
480 			sh = scsi_host_lookup(pdv->pdv_host_id);
481 			if (!sh) {
482 				pr_err("pSCSI: Unable to locate"
483 					" pdv_host_id: %d\n", pdv->pdv_host_id);
484 				return -EINVAL;
485 			}
486 			pdv->pdv_lld_host = sh;
487 		}
488 	} else {
489 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
490 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
491 				" struct Scsi_Host exists\n");
492 			return -EEXIST;
493 		}
494 	}
495 
496 	spin_lock_irq(sh->host_lock);
497 	list_for_each_entry(sd, &sh->__devices, siblings) {
498 		if ((pdv->pdv_channel_id != sd->channel) ||
499 		    (pdv->pdv_target_id != sd->id) ||
500 		    (pdv->pdv_lun_id != sd->lun))
501 			continue;
502 		/*
503 		 * Functions will release the held struct scsi_host->host_lock
504 		 * before calling calling pscsi_add_device_to_list() to register
505 		 * struct scsi_device with target_core_mod.
506 		 */
507 		switch (sd->type) {
508 		case TYPE_DISK:
509 		case TYPE_ZBC:
510 			ret = pscsi_create_type_disk(dev, sd);
511 			break;
512 		default:
513 			ret = pscsi_create_type_nondisk(dev, sd);
514 			break;
515 		}
516 
517 		if (ret) {
518 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
519 				scsi_host_put(sh);
520 			else if (legacy_mode_enable) {
521 				pscsi_pmode_enable_hba(hba, 0);
522 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
523 			}
524 			pdv->pdv_sd = NULL;
525 			return ret;
526 		}
527 		return 0;
528 	}
529 	spin_unlock_irq(sh->host_lock);
530 
531 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
532 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
533 
534 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
535 		scsi_host_put(sh);
536 	else if (legacy_mode_enable) {
537 		pscsi_pmode_enable_hba(hba, 0);
538 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
539 	}
540 
541 	return -ENODEV;
542 }
543 
544 static void pscsi_dev_call_rcu(struct rcu_head *p)
545 {
546 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
547 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
548 
549 	kfree(pdv);
550 }
551 
552 static void pscsi_free_device(struct se_device *dev)
553 {
554 	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
555 }
556 
557 static void pscsi_destroy_device(struct se_device *dev)
558 {
559 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
560 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
561 	struct scsi_device *sd = pdv->pdv_sd;
562 
563 	if (sd) {
564 		/*
565 		 * Release exclusive pSCSI internal struct block_device claim for
566 		 * struct scsi_device with TYPE_DISK or TYPE_ZBC
567 		 * from pscsi_create_type_disk()
568 		 */
569 		if ((sd->type == TYPE_DISK || sd->type == TYPE_ZBC) &&
570 		    pdv->pdv_bd) {
571 			blkdev_put(pdv->pdv_bd,
572 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
573 			pdv->pdv_bd = NULL;
574 		}
575 		/*
576 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
577 		 * to struct Scsi_Host now.
578 		 */
579 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
580 		    (phv->phv_lld_host != NULL))
581 			scsi_host_put(phv->phv_lld_host);
582 		else if (pdv->pdv_lld_host)
583 			scsi_host_put(pdv->pdv_lld_host);
584 
585 		scsi_device_put(sd);
586 
587 		pdv->pdv_sd = NULL;
588 	}
589 }
590 
591 static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
592 			       unsigned char *req_sense)
593 {
594 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
595 	struct scsi_device *sd = pdv->pdv_sd;
596 	struct pscsi_plugin_task *pt = cmd->priv;
597 	unsigned char *cdb;
598 	/*
599 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
600 	 * not been allocated because TCM is handling the emulation directly.
601 	 */
602 	if (!pt)
603 		return;
604 
605 	cdb = &pt->pscsi_cdb[0];
606 	/*
607 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
608 	 * forced.
609 	 */
610 	if (!cmd->data_length)
611 		goto after_mode_sense;
612 
613 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
614 	    scsi_status == SAM_STAT_GOOD) {
615 		bool read_only = target_lun_is_rdonly(cmd);
616 
617 		if (read_only) {
618 			unsigned char *buf;
619 
620 			buf = transport_kmap_data_sg(cmd);
621 			if (!buf) {
622 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
623 			} else {
624 				if (cdb[0] == MODE_SENSE_10) {
625 					if (!(buf[3] & 0x80))
626 						buf[3] |= 0x80;
627 				} else {
628 					if (!(buf[2] & 0x80))
629 						buf[2] |= 0x80;
630 				}
631 
632 				transport_kunmap_data_sg(cmd);
633 			}
634 		}
635 	}
636 after_mode_sense:
637 
638 	if (sd->type != TYPE_TAPE || !cmd->data_length)
639 		goto after_mode_select;
640 
641 	/*
642 	 * Hack to correctly obtain the initiator requested blocksize for
643 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
644 	 * struct scsi_device->sector_size will not contain the correct value
645 	 * by default, so we go ahead and set it so
646 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
647 	 * storage engine.
648 	 */
649 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
650 	     scsi_status == SAM_STAT_GOOD) {
651 		unsigned char *buf;
652 		u16 bdl;
653 		u32 blocksize;
654 
655 		buf = sg_virt(&cmd->t_data_sg[0]);
656 		if (!buf) {
657 			pr_err("Unable to get buf for scatterlist\n");
658 			goto after_mode_select;
659 		}
660 
661 		if (cdb[0] == MODE_SELECT)
662 			bdl = buf[3];
663 		else
664 			bdl = get_unaligned_be16(&buf[6]);
665 
666 		if (!bdl)
667 			goto after_mode_select;
668 
669 		if (cdb[0] == MODE_SELECT)
670 			blocksize = get_unaligned_be24(&buf[9]);
671 		else
672 			blocksize = get_unaligned_be24(&buf[13]);
673 
674 		sd->sector_size = blocksize;
675 	}
676 after_mode_select:
677 
678 	if (scsi_status == SAM_STAT_CHECK_CONDITION) {
679 		transport_copy_sense_to_cmd(cmd, req_sense);
680 
681 		/*
682 		 * check for TAPE device reads with
683 		 * FM/EOM/ILI set, so that we can get data
684 		 * back despite framework assumption that a
685 		 * check condition means there is no data
686 		 */
687 		if (sd->type == TYPE_TAPE &&
688 		    cmd->data_direction == DMA_FROM_DEVICE) {
689 			/*
690 			 * is sense data valid, fixed format,
691 			 * and have FM, EOM, or ILI set?
692 			 */
693 			if (req_sense[0] == 0xf0 &&	/* valid, fixed format */
694 			    req_sense[2] & 0xe0 &&	/* FM, EOM, or ILI */
695 			    (req_sense[2] & 0xf) == 0) { /* key==NO_SENSE */
696 				pr_debug("Tape FM/EOM/ILI status detected. Treat as normal read.\n");
697 				cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
698 			}
699 		}
700 	}
701 }
702 
703 enum {
704 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
705 	Opt_scsi_lun_id, Opt_err
706 };
707 
708 static match_table_t tokens = {
709 	{Opt_scsi_host_id, "scsi_host_id=%d"},
710 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
711 	{Opt_scsi_target_id, "scsi_target_id=%d"},
712 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
713 	{Opt_err, NULL}
714 };
715 
716 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
717 		const char *page, ssize_t count)
718 {
719 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
720 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
721 	char *orig, *ptr, *opts;
722 	substring_t args[MAX_OPT_ARGS];
723 	int ret = 0, arg, token;
724 
725 	opts = kstrdup(page, GFP_KERNEL);
726 	if (!opts)
727 		return -ENOMEM;
728 
729 	orig = opts;
730 
731 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
732 		if (!*ptr)
733 			continue;
734 
735 		token = match_token(ptr, tokens, args);
736 		switch (token) {
737 		case Opt_scsi_host_id:
738 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
739 				pr_err("PSCSI[%d]: Unable to accept"
740 					" scsi_host_id while phv_mode =="
741 					" PHV_LLD_SCSI_HOST_NO\n",
742 					phv->phv_host_id);
743 				ret = -EINVAL;
744 				goto out;
745 			}
746 			ret = match_int(args, &arg);
747 			if (ret)
748 				goto out;
749 			pdv->pdv_host_id = arg;
750 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
751 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
752 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
753 			break;
754 		case Opt_scsi_channel_id:
755 			ret = match_int(args, &arg);
756 			if (ret)
757 				goto out;
758 			pdv->pdv_channel_id = arg;
759 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
760 				" ID: %d\n",  phv->phv_host_id,
761 				pdv->pdv_channel_id);
762 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
763 			break;
764 		case Opt_scsi_target_id:
765 			ret = match_int(args, &arg);
766 			if (ret)
767 				goto out;
768 			pdv->pdv_target_id = arg;
769 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
770 				" ID: %d\n", phv->phv_host_id,
771 				pdv->pdv_target_id);
772 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
773 			break;
774 		case Opt_scsi_lun_id:
775 			ret = match_int(args, &arg);
776 			if (ret)
777 				goto out;
778 			pdv->pdv_lun_id = arg;
779 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
780 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
781 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
782 			break;
783 		default:
784 			break;
785 		}
786 	}
787 
788 out:
789 	kfree(orig);
790 	return (!ret) ? count : ret;
791 }
792 
793 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
794 {
795 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
796 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
797 	struct scsi_device *sd = pdv->pdv_sd;
798 	unsigned char host_id[16];
799 	ssize_t bl;
800 
801 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
802 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
803 	else
804 		snprintf(host_id, 16, "PHBA Mode");
805 
806 	bl = sprintf(b, "SCSI Device Bus Location:"
807 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
808 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
809 		host_id);
810 
811 	if (sd) {
812 		bl += sprintf(b + bl, "        Vendor: %."
813 			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
814 		bl += sprintf(b + bl, " Model: %."
815 			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
816 		bl += sprintf(b + bl, " Rev: %."
817 			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
818 	}
819 	return bl;
820 }
821 
822 static void pscsi_bi_endio(struct bio *bio)
823 {
824 	bio_put(bio);
825 }
826 
827 static inline struct bio *pscsi_get_bio(int nr_vecs)
828 {
829 	struct bio *bio;
830 	/*
831 	 * Use bio_malloc() following the comment in for bio -> struct request
832 	 * in block/blk-core.c:blk_make_request()
833 	 */
834 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
835 	if (!bio) {
836 		pr_err("PSCSI: bio_kmalloc() failed\n");
837 		return NULL;
838 	}
839 	bio->bi_end_io = pscsi_bi_endio;
840 
841 	return bio;
842 }
843 
844 static sense_reason_t
845 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
846 		struct request *req)
847 {
848 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
849 	struct bio *bio = NULL;
850 	struct page *page;
851 	struct scatterlist *sg;
852 	u32 data_len = cmd->data_length, i, len, bytes, off;
853 	int nr_pages = (cmd->data_length + sgl[0].offset +
854 			PAGE_SIZE - 1) >> PAGE_SHIFT;
855 	int nr_vecs = 0, rc;
856 	int rw = (cmd->data_direction == DMA_TO_DEVICE);
857 
858 	BUG_ON(!cmd->data_length);
859 
860 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
861 
862 	for_each_sg(sgl, sg, sgl_nents, i) {
863 		page = sg_page(sg);
864 		off = sg->offset;
865 		len = sg->length;
866 
867 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
868 			page, len, off);
869 
870 		/*
871 		 * We only have one page of data in each sg element,
872 		 * we can not cross a page boundary.
873 		 */
874 		if (off + len > PAGE_SIZE)
875 			goto fail;
876 
877 		if (len > 0 && data_len > 0) {
878 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
879 			bytes = min(bytes, data_len);
880 
881 			if (!bio) {
882 new_bio:
883 				nr_vecs = bio_max_segs(nr_pages);
884 				/*
885 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
886 				 */
887 				bio = pscsi_get_bio(nr_vecs);
888 				if (!bio)
889 					goto fail;
890 
891 				if (rw)
892 					bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
893 
894 				pr_debug("PSCSI: Allocated bio: %p,"
895 					" dir: %s nr_vecs: %d\n", bio,
896 					(rw) ? "rw" : "r", nr_vecs);
897 			}
898 
899 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
900 				" bio: %p page: %p len: %d off: %d\n", i, bio,
901 				page, len, off);
902 
903 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
904 					bio, page, bytes, off);
905 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
906 				bio_segments(bio), nr_vecs);
907 			if (rc != bytes) {
908 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
909 					" %d i: %d bio: %p, allocating another"
910 					" bio\n", bio->bi_vcnt, i, bio);
911 
912 				rc = blk_rq_append_bio(req, bio);
913 				if (rc) {
914 					pr_err("pSCSI: failed to append bio\n");
915 					goto fail;
916 				}
917 
918 				/*
919 				 * Clear the pointer so that another bio will
920 				 * be allocated with pscsi_get_bio() above.
921 				 */
922 				bio = NULL;
923 				goto new_bio;
924 			}
925 
926 			data_len -= bytes;
927 		}
928 	}
929 
930 	if (bio) {
931 		rc = blk_rq_append_bio(req, bio);
932 		if (rc) {
933 			pr_err("pSCSI: failed to append bio\n");
934 			goto fail;
935 		}
936 	}
937 
938 	return 0;
939 fail:
940 	if (bio)
941 		bio_put(bio);
942 	while (req->bio) {
943 		bio = req->bio;
944 		req->bio = bio->bi_next;
945 		bio_put(bio);
946 	}
947 	req->biotail = NULL;
948 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
949 }
950 
951 static sense_reason_t
952 pscsi_parse_cdb(struct se_cmd *cmd)
953 {
954 	if (cmd->se_cmd_flags & SCF_BIDI)
955 		return TCM_UNSUPPORTED_SCSI_OPCODE;
956 
957 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
958 }
959 
960 static sense_reason_t
961 pscsi_execute_cmd(struct se_cmd *cmd)
962 {
963 	struct scatterlist *sgl = cmd->t_data_sg;
964 	u32 sgl_nents = cmd->t_data_nents;
965 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
966 	struct pscsi_plugin_task *pt;
967 	struct request *req;
968 	sense_reason_t ret;
969 
970 	/*
971 	 * Dynamically alloc cdb space, since it may be larger than
972 	 * TCM_MAX_COMMAND_SIZE
973 	 */
974 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
975 	if (!pt) {
976 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
977 	}
978 	cmd->priv = pt;
979 
980 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
981 		scsi_command_size(cmd->t_task_cdb));
982 
983 	req = scsi_alloc_request(pdv->pdv_sd->request_queue,
984 			cmd->data_direction == DMA_TO_DEVICE ?
985 			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
986 	if (IS_ERR(req)) {
987 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
988 		goto fail;
989 	}
990 
991 	if (sgl) {
992 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
993 		if (ret)
994 			goto fail_put_request;
995 	}
996 
997 	req->end_io = pscsi_req_done;
998 	req->end_io_data = cmd;
999 	scsi_req(req)->cmd_len = scsi_command_size(pt->pscsi_cdb);
1000 	scsi_req(req)->cmd = &pt->pscsi_cdb[0];
1001 	if (pdv->pdv_sd->type == TYPE_DISK ||
1002 	    pdv->pdv_sd->type == TYPE_ZBC)
1003 		req->timeout = PS_TIMEOUT_DISK;
1004 	else
1005 		req->timeout = PS_TIMEOUT_OTHER;
1006 	scsi_req(req)->retries = PS_RETRY;
1007 
1008 	blk_execute_rq_nowait(NULL, req, (cmd->sam_task_attr == TCM_HEAD_TAG),
1009 			pscsi_req_done);
1010 
1011 	return 0;
1012 
1013 fail_put_request:
1014 	blk_mq_free_request(req);
1015 fail:
1016 	kfree(pt);
1017 	return ret;
1018 }
1019 
1020 /*	pscsi_get_device_type():
1021  *
1022  *
1023  */
1024 static u32 pscsi_get_device_type(struct se_device *dev)
1025 {
1026 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1027 	struct scsi_device *sd = pdv->pdv_sd;
1028 
1029 	return (sd) ? sd->type : TYPE_NO_LUN;
1030 }
1031 
1032 static sector_t pscsi_get_blocks(struct se_device *dev)
1033 {
1034 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1035 
1036 	if (pdv->pdv_bd)
1037 		return bdev_nr_sectors(pdv->pdv_bd);
1038 	return 0;
1039 }
1040 
1041 static void pscsi_req_done(struct request *req, blk_status_t status)
1042 {
1043 	struct se_cmd *cmd = req->end_io_data;
1044 	struct pscsi_plugin_task *pt = cmd->priv;
1045 	int result = scsi_req(req)->result;
1046 	enum sam_status scsi_status = result & 0xff;
1047 
1048 	if (scsi_status != SAM_STAT_GOOD) {
1049 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1050 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1051 			result);
1052 	}
1053 
1054 	pscsi_complete_cmd(cmd, scsi_status, scsi_req(req)->sense);
1055 
1056 	switch (host_byte(result)) {
1057 	case DID_OK:
1058 		target_complete_cmd_with_length(cmd, scsi_status,
1059 			cmd->data_length - scsi_req(req)->resid_len);
1060 		break;
1061 	default:
1062 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1063 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1064 			result);
1065 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1066 		break;
1067 	}
1068 
1069 	blk_mq_free_request(req);
1070 	kfree(pt);
1071 }
1072 
1073 static const struct target_backend_ops pscsi_ops = {
1074 	.name			= "pscsi",
1075 	.owner			= THIS_MODULE,
1076 	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH |
1077 				   TRANSPORT_FLAG_PASSTHROUGH_ALUA |
1078 				   TRANSPORT_FLAG_PASSTHROUGH_PGR,
1079 	.attach_hba		= pscsi_attach_hba,
1080 	.detach_hba		= pscsi_detach_hba,
1081 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1082 	.alloc_device		= pscsi_alloc_device,
1083 	.configure_device	= pscsi_configure_device,
1084 	.destroy_device		= pscsi_destroy_device,
1085 	.free_device		= pscsi_free_device,
1086 	.parse_cdb		= pscsi_parse_cdb,
1087 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1088 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1089 	.get_device_type	= pscsi_get_device_type,
1090 	.get_blocks		= pscsi_get_blocks,
1091 	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1092 };
1093 
1094 static int __init pscsi_module_init(void)
1095 {
1096 	return transport_backend_register(&pscsi_ops);
1097 }
1098 
1099 static void __exit pscsi_module_exit(void)
1100 {
1101 	target_backend_unregister(&pscsi_ops);
1102 }
1103 
1104 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1105 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1106 MODULE_LICENSE("GPL");
1107 
1108 module_init(pscsi_module_init);
1109 module_exit(pscsi_module_exit);
1110