1 /*******************************************************************************
2  * Filename:  target_core_pscsi.c
3  *
4  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
5  *
6  * (c) Copyright 2003-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/string.h>
27 #include <linux/parser.h>
28 #include <linux/timer.h>
29 #include <linux/blkdev.h>
30 #include <linux/blk_types.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/genhd.h>
34 #include <linux/cdrom.h>
35 #include <linux/ratelimit.h>
36 #include <linux/module.h>
37 #include <asm/unaligned.h>
38 
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_tcq.h>
42 
43 #include <target/target_core_base.h>
44 #include <target/target_core_backend.h>
45 
46 #include "target_core_alua.h"
47 #include "target_core_internal.h"
48 #include "target_core_pscsi.h"
49 
50 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
51 
52 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
53 {
54 	return container_of(dev, struct pscsi_dev_virt, dev);
55 }
56 
57 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
58 static void pscsi_req_done(struct request *, int);
59 
60 /*	pscsi_attach_hba():
61  *
62  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
63  *	from the passed SCSI Host ID.
64  */
65 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
66 {
67 	struct pscsi_hba_virt *phv;
68 
69 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
70 	if (!phv) {
71 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
72 		return -ENOMEM;
73 	}
74 	phv->phv_host_id = host_id;
75 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
76 
77 	hba->hba_ptr = phv;
78 
79 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
80 		" Generic Target Core Stack %s\n", hba->hba_id,
81 		PSCSI_VERSION, TARGET_CORE_VERSION);
82 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
83 	       hba->hba_id);
84 
85 	return 0;
86 }
87 
88 static void pscsi_detach_hba(struct se_hba *hba)
89 {
90 	struct pscsi_hba_virt *phv = hba->hba_ptr;
91 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
92 
93 	if (scsi_host) {
94 		scsi_host_put(scsi_host);
95 
96 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
97 			" Generic Target Core\n", hba->hba_id,
98 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
99 			"Unknown");
100 	} else
101 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
102 			" from Generic Target Core\n", hba->hba_id);
103 
104 	kfree(phv);
105 	hba->hba_ptr = NULL;
106 }
107 
108 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
109 {
110 	struct pscsi_hba_virt *phv = hba->hba_ptr;
111 	struct Scsi_Host *sh = phv->phv_lld_host;
112 	/*
113 	 * Release the struct Scsi_Host
114 	 */
115 	if (!mode_flag) {
116 		if (!sh)
117 			return 0;
118 
119 		phv->phv_lld_host = NULL;
120 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
121 
122 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
123 			" %s\n", hba->hba_id, (sh->hostt->name) ?
124 			(sh->hostt->name) : "Unknown");
125 
126 		scsi_host_put(sh);
127 		return 0;
128 	}
129 	/*
130 	 * Otherwise, locate struct Scsi_Host from the original passed
131 	 * pSCSI Host ID and enable for phba mode
132 	 */
133 	sh = scsi_host_lookup(phv->phv_host_id);
134 	if (!sh) {
135 		pr_err("pSCSI: Unable to locate SCSI Host for"
136 			" phv_host_id: %d\n", phv->phv_host_id);
137 		return -EINVAL;
138 	}
139 
140 	phv->phv_lld_host = sh;
141 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
142 
143 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
144 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
145 
146 	return 1;
147 }
148 
149 static void pscsi_tape_read_blocksize(struct se_device *dev,
150 		struct scsi_device *sdev)
151 {
152 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
153 	int ret;
154 
155 	buf = kzalloc(12, GFP_KERNEL);
156 	if (!buf)
157 		goto out_free;
158 
159 	memset(cdb, 0, MAX_COMMAND_SIZE);
160 	cdb[0] = MODE_SENSE;
161 	cdb[4] = 0x0c; /* 12 bytes */
162 
163 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
164 			HZ, 1, NULL);
165 	if (ret)
166 		goto out_free;
167 
168 	/*
169 	 * If MODE_SENSE still returns zero, set the default value to 1024.
170 	 */
171 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
172 out_free:
173 	if (!sdev->sector_size)
174 		sdev->sector_size = 1024;
175 
176 	kfree(buf);
177 }
178 
179 static void
180 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
181 {
182 	unsigned char *buf;
183 
184 	if (sdev->inquiry_len < INQUIRY_LEN)
185 		return;
186 
187 	buf = sdev->inquiry;
188 	if (!buf)
189 		return;
190 	/*
191 	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
192 	 */
193 	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
194 	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
195 	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
196 }
197 
198 static int
199 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
200 {
201 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
202 	int ret;
203 
204 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
205 	if (!buf)
206 		return -ENOMEM;
207 
208 	memset(cdb, 0, MAX_COMMAND_SIZE);
209 	cdb[0] = INQUIRY;
210 	cdb[1] = 0x01; /* Query VPD */
211 	cdb[2] = 0x80; /* Unit Serial Number */
212 	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
213 	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
214 
215 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
216 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
217 	if (ret)
218 		goto out_free;
219 
220 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
221 
222 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
223 
224 	kfree(buf);
225 	return 0;
226 
227 out_free:
228 	kfree(buf);
229 	return -EPERM;
230 }
231 
232 static void
233 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
234 		struct t10_wwn *wwn)
235 {
236 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
237 	int ident_len, page_len, off = 4, ret;
238 	struct t10_vpd *vpd;
239 
240 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
241 	if (!buf)
242 		return;
243 
244 	memset(cdb, 0, MAX_COMMAND_SIZE);
245 	cdb[0] = INQUIRY;
246 	cdb[1] = 0x01; /* Query VPD */
247 	cdb[2] = 0x83; /* Device Identifier */
248 	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
249 	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
250 
251 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
252 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
253 			      NULL, HZ, 1, NULL);
254 	if (ret)
255 		goto out;
256 
257 	page_len = (buf[2] << 8) | buf[3];
258 	while (page_len > 0) {
259 		/* Grab a pointer to the Identification descriptor */
260 		page_83 = &buf[off];
261 		ident_len = page_83[3];
262 		if (!ident_len) {
263 			pr_err("page_83[3]: identifier"
264 					" length zero!\n");
265 			break;
266 		}
267 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
268 
269 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
270 		if (!vpd) {
271 			pr_err("Unable to allocate memory for"
272 					" struct t10_vpd\n");
273 			goto out;
274 		}
275 		INIT_LIST_HEAD(&vpd->vpd_list);
276 
277 		transport_set_vpd_proto_id(vpd, page_83);
278 		transport_set_vpd_assoc(vpd, page_83);
279 
280 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
281 			off += (ident_len + 4);
282 			page_len -= (ident_len + 4);
283 			kfree(vpd);
284 			continue;
285 		}
286 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
287 			off += (ident_len + 4);
288 			page_len -= (ident_len + 4);
289 			kfree(vpd);
290 			continue;
291 		}
292 
293 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
294 		off += (ident_len + 4);
295 		page_len -= (ident_len + 4);
296 	}
297 
298 out:
299 	kfree(buf);
300 }
301 
302 static int pscsi_add_device_to_list(struct se_device *dev,
303 		struct scsi_device *sd)
304 {
305 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
306 	struct request_queue *q = sd->request_queue;
307 
308 	pdv->pdv_sd = sd;
309 
310 	if (!sd->queue_depth) {
311 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
312 
313 		pr_err("Set broken SCSI Device %d:%d:%llu"
314 			" queue_depth to %d\n", sd->channel, sd->id,
315 				sd->lun, sd->queue_depth);
316 	}
317 
318 	dev->dev_attrib.hw_block_size =
319 		min_not_zero((int)sd->sector_size, 512);
320 	dev->dev_attrib.hw_max_sectors =
321 		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
322 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
323 
324 	/*
325 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
326 	 */
327 	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
328 
329 	/*
330 	 * Locate VPD WWN Information used for various purposes within
331 	 * the Storage Engine.
332 	 */
333 	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
334 		/*
335 		 * If VPD Unit Serial returned GOOD status, try
336 		 * VPD Device Identification page (0x83).
337 		 */
338 		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
339 	}
340 
341 	/*
342 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
343 	 */
344 	if (sd->type == TYPE_TAPE) {
345 		pscsi_tape_read_blocksize(dev, sd);
346 		dev->dev_attrib.hw_block_size = sd->sector_size;
347 	}
348 	return 0;
349 }
350 
351 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
352 		const char *name)
353 {
354 	struct pscsi_dev_virt *pdv;
355 
356 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
357 	if (!pdv) {
358 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
359 		return NULL;
360 	}
361 
362 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
363 	return &pdv->dev;
364 }
365 
366 /*
367  * Called with struct Scsi_Host->host_lock called.
368  */
369 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
370 	__releases(sh->host_lock)
371 {
372 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
373 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
374 	struct Scsi_Host *sh = sd->host;
375 	struct block_device *bd;
376 	int ret;
377 
378 	if (scsi_device_get(sd)) {
379 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
380 			sh->host_no, sd->channel, sd->id, sd->lun);
381 		spin_unlock_irq(sh->host_lock);
382 		return -EIO;
383 	}
384 	spin_unlock_irq(sh->host_lock);
385 	/*
386 	 * Claim exclusive struct block_device access to struct scsi_device
387 	 * for TYPE_DISK using supplied udev_path
388 	 */
389 	bd = blkdev_get_by_path(dev->udev_path,
390 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
391 	if (IS_ERR(bd)) {
392 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
393 		scsi_device_put(sd);
394 		return PTR_ERR(bd);
395 	}
396 	pdv->pdv_bd = bd;
397 
398 	ret = pscsi_add_device_to_list(dev, sd);
399 	if (ret) {
400 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
401 		scsi_device_put(sd);
402 		return ret;
403 	}
404 
405 	pr_debug("CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%llu\n",
406 		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
407 	return 0;
408 }
409 
410 /*
411  * Called with struct Scsi_Host->host_lock called.
412  */
413 static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
414 	__releases(sh->host_lock)
415 {
416 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
417 	struct Scsi_Host *sh = sd->host;
418 	int ret;
419 
420 	if (scsi_device_get(sd)) {
421 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
422 			sh->host_no, sd->channel, sd->id, sd->lun);
423 		spin_unlock_irq(sh->host_lock);
424 		return -EIO;
425 	}
426 	spin_unlock_irq(sh->host_lock);
427 
428 	ret = pscsi_add_device_to_list(dev, sd);
429 	if (ret) {
430 		scsi_device_put(sd);
431 		return ret;
432 	}
433 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
434 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
435 		sd->channel, sd->id, sd->lun);
436 
437 	return 0;
438 }
439 
440 static int pscsi_configure_device(struct se_device *dev)
441 {
442 	struct se_hba *hba = dev->se_hba;
443 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
444 	struct scsi_device *sd;
445 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
446 	struct Scsi_Host *sh = phv->phv_lld_host;
447 	int legacy_mode_enable = 0;
448 	int ret;
449 
450 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
451 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
452 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
453 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
454 			" scsi_lun_id= parameters\n");
455 		return -EINVAL;
456 	}
457 
458 	/*
459 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
460 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
461 	 */
462 	if (!sh) {
463 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
464 			pr_err("pSCSI: Unable to locate struct"
465 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
466 			return -ENODEV;
467 		}
468 		/*
469 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
470 		 * reference, we enforce that udev_path has been set
471 		 */
472 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
473 			pr_err("pSCSI: udev_path attribute has not"
474 				" been set before ENABLE=1\n");
475 			return -EINVAL;
476 		}
477 		/*
478 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
479 		 * use the original TCM hba ID to reference Linux/SCSI Host No
480 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
481 		 */
482 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
483 			if (hba->dev_count) {
484 				pr_err("pSCSI: Unable to set hba_mode"
485 					" with active devices\n");
486 				return -EEXIST;
487 			}
488 
489 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
490 				return -ENODEV;
491 
492 			legacy_mode_enable = 1;
493 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
494 			sh = phv->phv_lld_host;
495 		} else {
496 			sh = scsi_host_lookup(pdv->pdv_host_id);
497 			if (!sh) {
498 				pr_err("pSCSI: Unable to locate"
499 					" pdv_host_id: %d\n", pdv->pdv_host_id);
500 				return -EINVAL;
501 			}
502 			pdv->pdv_lld_host = sh;
503 		}
504 	} else {
505 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
506 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
507 				" struct Scsi_Host exists\n");
508 			return -EEXIST;
509 		}
510 	}
511 
512 	spin_lock_irq(sh->host_lock);
513 	list_for_each_entry(sd, &sh->__devices, siblings) {
514 		if ((pdv->pdv_channel_id != sd->channel) ||
515 		    (pdv->pdv_target_id != sd->id) ||
516 		    (pdv->pdv_lun_id != sd->lun))
517 			continue;
518 		/*
519 		 * Functions will release the held struct scsi_host->host_lock
520 		 * before calling calling pscsi_add_device_to_list() to register
521 		 * struct scsi_device with target_core_mod.
522 		 */
523 		switch (sd->type) {
524 		case TYPE_DISK:
525 			ret = pscsi_create_type_disk(dev, sd);
526 			break;
527 		default:
528 			ret = pscsi_create_type_nondisk(dev, sd);
529 			break;
530 		}
531 
532 		if (ret) {
533 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
534 				scsi_host_put(sh);
535 			else if (legacy_mode_enable) {
536 				pscsi_pmode_enable_hba(hba, 0);
537 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
538 			}
539 			pdv->pdv_sd = NULL;
540 			return ret;
541 		}
542 		return 0;
543 	}
544 	spin_unlock_irq(sh->host_lock);
545 
546 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
547 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
548 
549 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
550 		scsi_host_put(sh);
551 	else if (legacy_mode_enable) {
552 		pscsi_pmode_enable_hba(hba, 0);
553 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
554 	}
555 
556 	return -ENODEV;
557 }
558 
559 static void pscsi_dev_call_rcu(struct rcu_head *p)
560 {
561 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
562 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
563 
564 	kfree(pdv);
565 }
566 
567 static void pscsi_free_device(struct se_device *dev)
568 {
569 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
570 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
571 	struct scsi_device *sd = pdv->pdv_sd;
572 
573 	if (sd) {
574 		/*
575 		 * Release exclusive pSCSI internal struct block_device claim for
576 		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
577 		 */
578 		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
579 			blkdev_put(pdv->pdv_bd,
580 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
581 			pdv->pdv_bd = NULL;
582 		}
583 		/*
584 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
585 		 * to struct Scsi_Host now.
586 		 */
587 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
588 		    (phv->phv_lld_host != NULL))
589 			scsi_host_put(phv->phv_lld_host);
590 		else if (pdv->pdv_lld_host)
591 			scsi_host_put(pdv->pdv_lld_host);
592 
593 		scsi_device_put(sd);
594 
595 		pdv->pdv_sd = NULL;
596 	}
597 	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
598 }
599 
600 static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
601 				     unsigned char *sense_buffer)
602 {
603 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
604 	struct scsi_device *sd = pdv->pdv_sd;
605 	int result;
606 	struct pscsi_plugin_task *pt = cmd->priv;
607 	unsigned char *cdb;
608 	/*
609 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
610 	 * not been allocated because TCM is handling the emulation directly.
611 	 */
612 	if (!pt)
613 		return;
614 
615 	cdb = &pt->pscsi_cdb[0];
616 	result = pt->pscsi_result;
617 	/*
618 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
619 	 * forced.
620 	 */
621 	if (!cmd->data_length)
622 		goto after_mode_sense;
623 
624 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
625 	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
626 		bool read_only = target_lun_is_rdonly(cmd);
627 
628 		if (read_only) {
629 			unsigned char *buf;
630 
631 			buf = transport_kmap_data_sg(cmd);
632 			if (!buf)
633 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
634 
635 			if (cdb[0] == MODE_SENSE_10) {
636 				if (!(buf[3] & 0x80))
637 					buf[3] |= 0x80;
638 			} else {
639 				if (!(buf[2] & 0x80))
640 					buf[2] |= 0x80;
641 			}
642 
643 			transport_kunmap_data_sg(cmd);
644 		}
645 	}
646 after_mode_sense:
647 
648 	if (sd->type != TYPE_TAPE || !cmd->data_length)
649 		goto after_mode_select;
650 
651 	/*
652 	 * Hack to correctly obtain the initiator requested blocksize for
653 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
654 	 * struct scsi_device->sector_size will not contain the correct value
655 	 * by default, so we go ahead and set it so
656 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
657 	 * storage engine.
658 	 */
659 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
660 	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
661 		unsigned char *buf;
662 		u16 bdl;
663 		u32 blocksize;
664 
665 		buf = sg_virt(&sg[0]);
666 		if (!buf) {
667 			pr_err("Unable to get buf for scatterlist\n");
668 			goto after_mode_select;
669 		}
670 
671 		if (cdb[0] == MODE_SELECT)
672 			bdl = (buf[3]);
673 		else
674 			bdl = (buf[6] << 8) | (buf[7]);
675 
676 		if (!bdl)
677 			goto after_mode_select;
678 
679 		if (cdb[0] == MODE_SELECT)
680 			blocksize = (buf[9] << 16) | (buf[10] << 8) |
681 					(buf[11]);
682 		else
683 			blocksize = (buf[13] << 16) | (buf[14] << 8) |
684 					(buf[15]);
685 
686 		sd->sector_size = blocksize;
687 	}
688 after_mode_select:
689 
690 	if (sense_buffer && (status_byte(result) & CHECK_CONDITION)) {
691 		memcpy(sense_buffer, pt->pscsi_sense, TRANSPORT_SENSE_BUFFER);
692 		cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
693 	}
694 }
695 
696 enum {
697 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
698 	Opt_scsi_lun_id, Opt_err
699 };
700 
701 static match_table_t tokens = {
702 	{Opt_scsi_host_id, "scsi_host_id=%d"},
703 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
704 	{Opt_scsi_target_id, "scsi_target_id=%d"},
705 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
706 	{Opt_err, NULL}
707 };
708 
709 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
710 		const char *page, ssize_t count)
711 {
712 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
713 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
714 	char *orig, *ptr, *opts;
715 	substring_t args[MAX_OPT_ARGS];
716 	int ret = 0, arg, token;
717 
718 	opts = kstrdup(page, GFP_KERNEL);
719 	if (!opts)
720 		return -ENOMEM;
721 
722 	orig = opts;
723 
724 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
725 		if (!*ptr)
726 			continue;
727 
728 		token = match_token(ptr, tokens, args);
729 		switch (token) {
730 		case Opt_scsi_host_id:
731 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
732 				pr_err("PSCSI[%d]: Unable to accept"
733 					" scsi_host_id while phv_mode =="
734 					" PHV_LLD_SCSI_HOST_NO\n",
735 					phv->phv_host_id);
736 				ret = -EINVAL;
737 				goto out;
738 			}
739 			ret = match_int(args, &arg);
740 			if (ret)
741 				goto out;
742 			pdv->pdv_host_id = arg;
743 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
744 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
745 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
746 			break;
747 		case Opt_scsi_channel_id:
748 			ret = match_int(args, &arg);
749 			if (ret)
750 				goto out;
751 			pdv->pdv_channel_id = arg;
752 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
753 				" ID: %d\n",  phv->phv_host_id,
754 				pdv->pdv_channel_id);
755 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
756 			break;
757 		case Opt_scsi_target_id:
758 			ret = match_int(args, &arg);
759 			if (ret)
760 				goto out;
761 			pdv->pdv_target_id = arg;
762 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
763 				" ID: %d\n", phv->phv_host_id,
764 				pdv->pdv_target_id);
765 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
766 			break;
767 		case Opt_scsi_lun_id:
768 			ret = match_int(args, &arg);
769 			if (ret)
770 				goto out;
771 			pdv->pdv_lun_id = arg;
772 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
773 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
774 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
775 			break;
776 		default:
777 			break;
778 		}
779 	}
780 
781 out:
782 	kfree(orig);
783 	return (!ret) ? count : ret;
784 }
785 
786 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
787 {
788 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
789 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
790 	struct scsi_device *sd = pdv->pdv_sd;
791 	unsigned char host_id[16];
792 	ssize_t bl;
793 	int i;
794 
795 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
796 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
797 	else
798 		snprintf(host_id, 16, "PHBA Mode");
799 
800 	bl = sprintf(b, "SCSI Device Bus Location:"
801 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
802 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
803 		host_id);
804 
805 	if (sd) {
806 		bl += sprintf(b + bl, "        ");
807 		bl += sprintf(b + bl, "Vendor: ");
808 		for (i = 0; i < 8; i++) {
809 			if (ISPRINT(sd->vendor[i]))   /* printable character? */
810 				bl += sprintf(b + bl, "%c", sd->vendor[i]);
811 			else
812 				bl += sprintf(b + bl, " ");
813 		}
814 		bl += sprintf(b + bl, " Model: ");
815 		for (i = 0; i < 16; i++) {
816 			if (ISPRINT(sd->model[i]))   /* printable character ? */
817 				bl += sprintf(b + bl, "%c", sd->model[i]);
818 			else
819 				bl += sprintf(b + bl, " ");
820 		}
821 		bl += sprintf(b + bl, " Rev: ");
822 		for (i = 0; i < 4; i++) {
823 			if (ISPRINT(sd->rev[i]))   /* printable character ? */
824 				bl += sprintf(b + bl, "%c", sd->rev[i]);
825 			else
826 				bl += sprintf(b + bl, " ");
827 		}
828 		bl += sprintf(b + bl, "\n");
829 	}
830 	return bl;
831 }
832 
833 static void pscsi_bi_endio(struct bio *bio)
834 {
835 	bio_put(bio);
836 }
837 
838 static inline struct bio *pscsi_get_bio(int nr_vecs)
839 {
840 	struct bio *bio;
841 	/*
842 	 * Use bio_malloc() following the comment in for bio -> struct request
843 	 * in block/blk-core.c:blk_make_request()
844 	 */
845 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
846 	if (!bio) {
847 		pr_err("PSCSI: bio_kmalloc() failed\n");
848 		return NULL;
849 	}
850 	bio->bi_end_io = pscsi_bi_endio;
851 
852 	return bio;
853 }
854 
855 static sense_reason_t
856 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
857 		struct request *req)
858 {
859 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
860 	struct bio *bio = NULL;
861 	struct page *page;
862 	struct scatterlist *sg;
863 	u32 data_len = cmd->data_length, i, len, bytes, off;
864 	int nr_pages = (cmd->data_length + sgl[0].offset +
865 			PAGE_SIZE - 1) >> PAGE_SHIFT;
866 	int nr_vecs = 0, rc;
867 	int rw = (cmd->data_direction == DMA_TO_DEVICE);
868 
869 	BUG_ON(!cmd->data_length);
870 
871 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
872 
873 	for_each_sg(sgl, sg, sgl_nents, i) {
874 		page = sg_page(sg);
875 		off = sg->offset;
876 		len = sg->length;
877 
878 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
879 			page, len, off);
880 
881 		/*
882 		 * We only have one page of data in each sg element,
883 		 * we can not cross a page boundary.
884 		 */
885 		if (off + len > PAGE_SIZE)
886 			goto fail;
887 
888 		if (len > 0 && data_len > 0) {
889 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
890 			bytes = min(bytes, data_len);
891 
892 			if (!bio) {
893 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
894 				nr_pages -= nr_vecs;
895 				/*
896 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
897 				 */
898 				bio = pscsi_get_bio(nr_vecs);
899 				if (!bio)
900 					goto fail;
901 
902 				if (rw)
903 					bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
904 
905 				pr_debug("PSCSI: Allocated bio: %p,"
906 					" dir: %s nr_vecs: %d\n", bio,
907 					(rw) ? "rw" : "r", nr_vecs);
908 			}
909 
910 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
911 				" bio: %p page: %p len: %d off: %d\n", i, bio,
912 				page, len, off);
913 
914 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
915 					bio, page, bytes, off);
916 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
917 				bio_segments(bio), nr_vecs);
918 			if (rc != bytes) {
919 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
920 					" %d i: %d bio: %p, allocating another"
921 					" bio\n", bio->bi_vcnt, i, bio);
922 
923 				rc = blk_rq_append_bio(req, bio);
924 				if (rc) {
925 					pr_err("pSCSI: failed to append bio\n");
926 					goto fail;
927 				}
928 
929 				/*
930 				 * Clear the pointer so that another bio will
931 				 * be allocated with pscsi_get_bio() above.
932 				 */
933 				bio = NULL;
934 			}
935 
936 			data_len -= bytes;
937 		}
938 	}
939 
940 	if (bio) {
941 		rc = blk_rq_append_bio(req, bio);
942 		if (rc) {
943 			pr_err("pSCSI: failed to append bio\n");
944 			goto fail;
945 		}
946 	}
947 
948 	return 0;
949 fail:
950 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
951 }
952 
953 static sense_reason_t
954 pscsi_parse_cdb(struct se_cmd *cmd)
955 {
956 	if (cmd->se_cmd_flags & SCF_BIDI)
957 		return TCM_UNSUPPORTED_SCSI_OPCODE;
958 
959 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
960 }
961 
962 static sense_reason_t
963 pscsi_execute_cmd(struct se_cmd *cmd)
964 {
965 	struct scatterlist *sgl = cmd->t_data_sg;
966 	u32 sgl_nents = cmd->t_data_nents;
967 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
968 	struct pscsi_plugin_task *pt;
969 	struct request *req;
970 	sense_reason_t ret;
971 
972 	/*
973 	 * Dynamically alloc cdb space, since it may be larger than
974 	 * TCM_MAX_COMMAND_SIZE
975 	 */
976 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
977 	if (!pt) {
978 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
979 	}
980 	cmd->priv = pt;
981 
982 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
983 		scsi_command_size(cmd->t_task_cdb));
984 
985 	req = blk_get_request(pdv->pdv_sd->request_queue,
986 			cmd->data_direction == DMA_TO_DEVICE ?
987 			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
988 			GFP_KERNEL);
989 	if (IS_ERR(req)) {
990 		pr_err("PSCSI: blk_get_request() failed\n");
991 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
992 		goto fail;
993 	}
994 
995 	scsi_req_init(req);
996 
997 	if (sgl) {
998 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
999 		if (ret)
1000 			goto fail_put_request;
1001 	}
1002 
1003 	req->end_io = pscsi_req_done;
1004 	req->end_io_data = cmd;
1005 	scsi_req(req)->cmd_len = scsi_command_size(pt->pscsi_cdb);
1006 	scsi_req(req)->cmd = &pt->pscsi_cdb[0];
1007 	if (pdv->pdv_sd->type == TYPE_DISK)
1008 		req->timeout = PS_TIMEOUT_DISK;
1009 	else
1010 		req->timeout = PS_TIMEOUT_OTHER;
1011 	scsi_req(req)->retries = PS_RETRY;
1012 
1013 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1014 			(cmd->sam_task_attr == TCM_HEAD_TAG),
1015 			pscsi_req_done);
1016 
1017 	return 0;
1018 
1019 fail_put_request:
1020 	blk_put_request(req);
1021 fail:
1022 	kfree(pt);
1023 	return ret;
1024 }
1025 
1026 /*	pscsi_get_device_type():
1027  *
1028  *
1029  */
1030 static u32 pscsi_get_device_type(struct se_device *dev)
1031 {
1032 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1033 	struct scsi_device *sd = pdv->pdv_sd;
1034 
1035 	return (sd) ? sd->type : TYPE_NO_LUN;
1036 }
1037 
1038 static sector_t pscsi_get_blocks(struct se_device *dev)
1039 {
1040 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1041 
1042 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1043 		return pdv->pdv_bd->bd_part->nr_sects;
1044 
1045 	return 0;
1046 }
1047 
1048 static void pscsi_req_done(struct request *req, int uptodate)
1049 {
1050 	struct se_cmd *cmd = req->end_io_data;
1051 	struct pscsi_plugin_task *pt = cmd->priv;
1052 
1053 	pt->pscsi_result = scsi_req(req)->result;
1054 	pt->pscsi_resid = scsi_req(req)->resid_len;
1055 
1056 	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
1057 	if (cmd->scsi_status) {
1058 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1059 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1060 			pt->pscsi_result);
1061 	}
1062 
1063 	switch (host_byte(pt->pscsi_result)) {
1064 	case DID_OK:
1065 		target_complete_cmd(cmd, cmd->scsi_status);
1066 		break;
1067 	default:
1068 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1069 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1070 			pt->pscsi_result);
1071 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1072 		break;
1073 	}
1074 
1075 	memcpy(pt->pscsi_sense, scsi_req(req)->sense, TRANSPORT_SENSE_BUFFER);
1076 	__blk_put_request(req->q, req);
1077 	kfree(pt);
1078 }
1079 
1080 static const struct target_backend_ops pscsi_ops = {
1081 	.name			= "pscsi",
1082 	.owner			= THIS_MODULE,
1083 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH |
1084 				  TRANSPORT_FLAG_PASSTHROUGH_ALUA |
1085 				  TRANSPORT_FLAG_PASSTHROUGH_PGR,
1086 	.attach_hba		= pscsi_attach_hba,
1087 	.detach_hba		= pscsi_detach_hba,
1088 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1089 	.alloc_device		= pscsi_alloc_device,
1090 	.configure_device	= pscsi_configure_device,
1091 	.free_device		= pscsi_free_device,
1092 	.transport_complete	= pscsi_transport_complete,
1093 	.parse_cdb		= pscsi_parse_cdb,
1094 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1095 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1096 	.get_device_type	= pscsi_get_device_type,
1097 	.get_blocks		= pscsi_get_blocks,
1098 	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1099 };
1100 
1101 static int __init pscsi_module_init(void)
1102 {
1103 	return transport_backend_register(&pscsi_ops);
1104 }
1105 
1106 static void __exit pscsi_module_exit(void)
1107 {
1108 	target_backend_unregister(&pscsi_ops);
1109 }
1110 
1111 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1112 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1113 MODULE_LICENSE("GPL");
1114 
1115 module_init(pscsi_module_init);
1116 module_exit(pscsi_module_exit);
1117