xref: /linux/drivers/target/target_core_pscsi.c (revision 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb)
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 #include <target/target_core_backend_configfs.h>
46 
47 #include "target_core_alua.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 struct se_subsystem_api pscsi_template;
58 
59 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
60 static void pscsi_req_done(struct request *, int);
61 
62 /*	pscsi_attach_hba():
63  *
64  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
65  *	from the passed SCSI Host ID.
66  */
67 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
68 {
69 	struct pscsi_hba_virt *phv;
70 
71 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
72 	if (!phv) {
73 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
74 		return -ENOMEM;
75 	}
76 	phv->phv_host_id = host_id;
77 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
78 
79 	hba->hba_ptr = phv;
80 
81 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
82 		" Generic Target Core Stack %s\n", hba->hba_id,
83 		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
84 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
85 	       hba->hba_id);
86 
87 	return 0;
88 }
89 
90 static void pscsi_detach_hba(struct se_hba *hba)
91 {
92 	struct pscsi_hba_virt *phv = hba->hba_ptr;
93 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
94 
95 	if (scsi_host) {
96 		scsi_host_put(scsi_host);
97 
98 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
99 			" Generic Target Core\n", hba->hba_id,
100 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
101 			"Unknown");
102 	} else
103 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
104 			" from Generic Target Core\n", hba->hba_id);
105 
106 	kfree(phv);
107 	hba->hba_ptr = NULL;
108 }
109 
110 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
111 {
112 	struct pscsi_hba_virt *phv = hba->hba_ptr;
113 	struct Scsi_Host *sh = phv->phv_lld_host;
114 	/*
115 	 * Release the struct Scsi_Host
116 	 */
117 	if (!mode_flag) {
118 		if (!sh)
119 			return 0;
120 
121 		phv->phv_lld_host = NULL;
122 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
123 
124 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
125 			" %s\n", hba->hba_id, (sh->hostt->name) ?
126 			(sh->hostt->name) : "Unknown");
127 
128 		scsi_host_put(sh);
129 		return 0;
130 	}
131 	/*
132 	 * Otherwise, locate struct Scsi_Host from the original passed
133 	 * pSCSI Host ID and enable for phba mode
134 	 */
135 	sh = scsi_host_lookup(phv->phv_host_id);
136 	if (!sh) {
137 		pr_err("pSCSI: Unable to locate SCSI Host for"
138 			" phv_host_id: %d\n", phv->phv_host_id);
139 		return -EINVAL;
140 	}
141 
142 	phv->phv_lld_host = sh;
143 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
144 
145 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
146 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
147 
148 	return 1;
149 }
150 
151 static void pscsi_tape_read_blocksize(struct se_device *dev,
152 		struct scsi_device *sdev)
153 {
154 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
155 	int ret;
156 
157 	buf = kzalloc(12, GFP_KERNEL);
158 	if (!buf)
159 		return;
160 
161 	memset(cdb, 0, MAX_COMMAND_SIZE);
162 	cdb[0] = MODE_SENSE;
163 	cdb[4] = 0x0c; /* 12 bytes */
164 
165 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
166 			HZ, 1, NULL);
167 	if (ret)
168 		goto out_free;
169 
170 	/*
171 	 * If MODE_SENSE still returns zero, set the default value to 1024.
172 	 */
173 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
174 	if (!sdev->sector_size)
175 		sdev->sector_size = 1024;
176 out_free:
177 	kfree(buf);
178 }
179 
180 static void
181 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
182 {
183 	unsigned char *buf;
184 
185 	if (sdev->inquiry_len < INQUIRY_LEN)
186 		return;
187 
188 	buf = sdev->inquiry;
189 	if (!buf)
190 		return;
191 	/*
192 	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
193 	 */
194 	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
195 	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
196 	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
197 }
198 
199 static int
200 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
201 {
202 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
203 	int ret;
204 
205 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
206 	if (!buf)
207 		return -ENOMEM;
208 
209 	memset(cdb, 0, MAX_COMMAND_SIZE);
210 	cdb[0] = INQUIRY;
211 	cdb[1] = 0x01; /* Query VPD */
212 	cdb[2] = 0x80; /* Unit Serial Number */
213 	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
214 	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
215 
216 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
217 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
218 	if (ret)
219 		goto out_free;
220 
221 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
222 
223 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
224 
225 	kfree(buf);
226 	return 0;
227 
228 out_free:
229 	kfree(buf);
230 	return -EPERM;
231 }
232 
233 static void
234 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
235 		struct t10_wwn *wwn)
236 {
237 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
238 	int ident_len, page_len, off = 4, ret;
239 	struct t10_vpd *vpd;
240 
241 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
242 	if (!buf)
243 		return;
244 
245 	memset(cdb, 0, MAX_COMMAND_SIZE);
246 	cdb[0] = INQUIRY;
247 	cdb[1] = 0x01; /* Query VPD */
248 	cdb[2] = 0x83; /* Device Identifier */
249 	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
250 	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
251 
252 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
253 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
254 			      NULL, HZ, 1, NULL);
255 	if (ret)
256 		goto out;
257 
258 	page_len = (buf[2] << 8) | buf[3];
259 	while (page_len > 0) {
260 		/* Grab a pointer to the Identification descriptor */
261 		page_83 = &buf[off];
262 		ident_len = page_83[3];
263 		if (!ident_len) {
264 			pr_err("page_83[3]: identifier"
265 					" length zero!\n");
266 			break;
267 		}
268 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
269 
270 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
271 		if (!vpd) {
272 			pr_err("Unable to allocate memory for"
273 					" struct t10_vpd\n");
274 			goto out;
275 		}
276 		INIT_LIST_HEAD(&vpd->vpd_list);
277 
278 		transport_set_vpd_proto_id(vpd, page_83);
279 		transport_set_vpd_assoc(vpd, page_83);
280 
281 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
282 			off += (ident_len + 4);
283 			page_len -= (ident_len + 4);
284 			kfree(vpd);
285 			continue;
286 		}
287 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
288 			off += (ident_len + 4);
289 			page_len -= (ident_len + 4);
290 			kfree(vpd);
291 			continue;
292 		}
293 
294 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
295 		off += (ident_len + 4);
296 		page_len -= (ident_len + 4);
297 	}
298 
299 out:
300 	kfree(buf);
301 }
302 
303 static int pscsi_add_device_to_list(struct se_device *dev,
304 		struct scsi_device *sd)
305 {
306 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
307 	struct request_queue *q = sd->request_queue;
308 
309 	pdv->pdv_sd = sd;
310 
311 	if (!sd->queue_depth) {
312 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
313 
314 		pr_err("Set broken SCSI Device %d:%d:%llu"
315 			" queue_depth to %d\n", sd->channel, sd->id,
316 				sd->lun, sd->queue_depth);
317 	}
318 
319 	dev->dev_attrib.hw_block_size = sd->sector_size;
320 	dev->dev_attrib.hw_max_sectors =
321 		min_t(int, 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 	return 0;
347 }
348 
349 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
350 		const char *name)
351 {
352 	struct pscsi_dev_virt *pdv;
353 
354 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
355 	if (!pdv) {
356 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
357 		return NULL;
358 	}
359 
360 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
361 	return &pdv->dev;
362 }
363 
364 /*
365  * Called with struct Scsi_Host->host_lock called.
366  */
367 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
368 	__releases(sh->host_lock)
369 {
370 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
371 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
372 	struct Scsi_Host *sh = sd->host;
373 	struct block_device *bd;
374 	int ret;
375 
376 	if (scsi_device_get(sd)) {
377 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
378 			sh->host_no, sd->channel, sd->id, sd->lun);
379 		spin_unlock_irq(sh->host_lock);
380 		return -EIO;
381 	}
382 	spin_unlock_irq(sh->host_lock);
383 	/*
384 	 * Claim exclusive struct block_device access to struct scsi_device
385 	 * for TYPE_DISK using supplied udev_path
386 	 */
387 	bd = blkdev_get_by_path(dev->udev_path,
388 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
389 	if (IS_ERR(bd)) {
390 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
391 		scsi_device_put(sd);
392 		return PTR_ERR(bd);
393 	}
394 	pdv->pdv_bd = bd;
395 
396 	ret = pscsi_add_device_to_list(dev, sd);
397 	if (ret) {
398 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
399 		scsi_device_put(sd);
400 		return ret;
401 	}
402 
403 	pr_debug("CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%llu\n",
404 		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
405 	return 0;
406 }
407 
408 /*
409  * Called with struct Scsi_Host->host_lock called.
410  */
411 static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
412 	__releases(sh->host_lock)
413 {
414 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
415 	struct Scsi_Host *sh = sd->host;
416 	int ret;
417 
418 	if (scsi_device_get(sd)) {
419 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
420 			sh->host_no, sd->channel, sd->id, sd->lun);
421 		spin_unlock_irq(sh->host_lock);
422 		return -EIO;
423 	}
424 	spin_unlock_irq(sh->host_lock);
425 
426 	ret = pscsi_add_device_to_list(dev, sd);
427 	if (ret) {
428 		scsi_device_put(sd);
429 		return ret;
430 	}
431 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
432 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
433 		sd->channel, sd->id, sd->lun);
434 
435 	return 0;
436 }
437 
438 /*
439  * Called with struct Scsi_Host->host_lock called.
440  */
441 static int pscsi_create_type_other(struct se_device *dev,
442 		struct scsi_device *sd)
443 	__releases(sh->host_lock)
444 {
445 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
446 	struct Scsi_Host *sh = sd->host;
447 	int ret;
448 
449 	spin_unlock_irq(sh->host_lock);
450 	ret = pscsi_add_device_to_list(dev, sd);
451 	if (ret)
452 		return ret;
453 
454 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
455 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
456 		sd->channel, sd->id, sd->lun);
457 	return 0;
458 }
459 
460 static int pscsi_configure_device(struct se_device *dev)
461 {
462 	struct se_hba *hba = dev->se_hba;
463 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
464 	struct scsi_device *sd;
465 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
466 	struct Scsi_Host *sh = phv->phv_lld_host;
467 	int legacy_mode_enable = 0;
468 	int ret;
469 
470 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
471 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
472 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
473 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
474 			" scsi_lun_id= parameters\n");
475 		return -EINVAL;
476 	}
477 
478 	/*
479 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
480 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
481 	 */
482 	if (!sh) {
483 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
484 			pr_err("pSCSI: Unable to locate struct"
485 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
486 			return -ENODEV;
487 		}
488 		/*
489 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
490 		 * reference, we enforce that udev_path has been set
491 		 */
492 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
493 			pr_err("pSCSI: udev_path attribute has not"
494 				" been set before ENABLE=1\n");
495 			return -EINVAL;
496 		}
497 		/*
498 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
499 		 * use the original TCM hba ID to reference Linux/SCSI Host No
500 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
501 		 */
502 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
503 			if (hba->dev_count) {
504 				pr_err("pSCSI: Unable to set hba_mode"
505 					" with active devices\n");
506 				return -EEXIST;
507 			}
508 
509 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
510 				return -ENODEV;
511 
512 			legacy_mode_enable = 1;
513 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
514 			sh = phv->phv_lld_host;
515 		} else {
516 			sh = scsi_host_lookup(pdv->pdv_host_id);
517 			if (!sh) {
518 				pr_err("pSCSI: Unable to locate"
519 					" pdv_host_id: %d\n", pdv->pdv_host_id);
520 				return -EINVAL;
521 			}
522 			pdv->pdv_lld_host = sh;
523 		}
524 	} else {
525 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
526 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
527 				" struct Scsi_Host exists\n");
528 			return -EEXIST;
529 		}
530 	}
531 
532 	spin_lock_irq(sh->host_lock);
533 	list_for_each_entry(sd, &sh->__devices, siblings) {
534 		if ((pdv->pdv_channel_id != sd->channel) ||
535 		    (pdv->pdv_target_id != sd->id) ||
536 		    (pdv->pdv_lun_id != sd->lun))
537 			continue;
538 		/*
539 		 * Functions will release the held struct scsi_host->host_lock
540 		 * before calling calling pscsi_add_device_to_list() to register
541 		 * struct scsi_device with target_core_mod.
542 		 */
543 		switch (sd->type) {
544 		case TYPE_DISK:
545 			ret = pscsi_create_type_disk(dev, sd);
546 			break;
547 		case TYPE_ROM:
548 			ret = pscsi_create_type_rom(dev, sd);
549 			break;
550 		default:
551 			ret = pscsi_create_type_other(dev, sd);
552 			break;
553 		}
554 
555 		if (ret) {
556 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
557 				scsi_host_put(sh);
558 			else if (legacy_mode_enable) {
559 				pscsi_pmode_enable_hba(hba, 0);
560 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
561 			}
562 			pdv->pdv_sd = NULL;
563 			return ret;
564 		}
565 		return 0;
566 	}
567 	spin_unlock_irq(sh->host_lock);
568 
569 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
570 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
571 
572 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
573 		scsi_host_put(sh);
574 	else if (legacy_mode_enable) {
575 		pscsi_pmode_enable_hba(hba, 0);
576 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
577 	}
578 
579 	return -ENODEV;
580 }
581 
582 static void pscsi_free_device(struct se_device *dev)
583 {
584 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
585 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
586 	struct scsi_device *sd = pdv->pdv_sd;
587 
588 	if (sd) {
589 		/*
590 		 * Release exclusive pSCSI internal struct block_device claim for
591 		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
592 		 */
593 		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
594 			blkdev_put(pdv->pdv_bd,
595 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
596 			pdv->pdv_bd = NULL;
597 		}
598 		/*
599 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
600 		 * to struct Scsi_Host now.
601 		 */
602 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
603 		    (phv->phv_lld_host != NULL))
604 			scsi_host_put(phv->phv_lld_host);
605 		else if (pdv->pdv_lld_host)
606 			scsi_host_put(pdv->pdv_lld_host);
607 
608 		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
609 			scsi_device_put(sd);
610 
611 		pdv->pdv_sd = NULL;
612 	}
613 
614 	kfree(pdv);
615 }
616 
617 static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
618 				     unsigned char *sense_buffer)
619 {
620 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
621 	struct scsi_device *sd = pdv->pdv_sd;
622 	int result;
623 	struct pscsi_plugin_task *pt = cmd->priv;
624 	unsigned char *cdb;
625 	/*
626 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
627 	 * not been allocated because TCM is handling the emulation directly.
628 	 */
629 	if (!pt)
630 		return;
631 
632 	cdb = &pt->pscsi_cdb[0];
633 	result = pt->pscsi_result;
634 	/*
635 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
636 	 * forced.
637 	 */
638 	if (!cmd->se_deve || !cmd->data_length)
639 		goto after_mode_sense;
640 
641 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
642 	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
643 		if (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY) {
644 			unsigned char *buf;
645 
646 			buf = transport_kmap_data_sg(cmd);
647 			if (!buf)
648 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
649 
650 			if (cdb[0] == MODE_SENSE_10) {
651 				if (!(buf[3] & 0x80))
652 					buf[3] |= 0x80;
653 			} else {
654 				if (!(buf[2] & 0x80))
655 					buf[2] |= 0x80;
656 			}
657 
658 			transport_kunmap_data_sg(cmd);
659 		}
660 	}
661 after_mode_sense:
662 
663 	if (sd->type != TYPE_TAPE || !cmd->data_length)
664 		goto after_mode_select;
665 
666 	/*
667 	 * Hack to correctly obtain the initiator requested blocksize for
668 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
669 	 * struct scsi_device->sector_size will not contain the correct value
670 	 * by default, so we go ahead and set it so
671 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
672 	 * storage engine.
673 	 */
674 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
675 	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
676 		unsigned char *buf;
677 		u16 bdl;
678 		u32 blocksize;
679 
680 		buf = sg_virt(&sg[0]);
681 		if (!buf) {
682 			pr_err("Unable to get buf for scatterlist\n");
683 			goto after_mode_select;
684 		}
685 
686 		if (cdb[0] == MODE_SELECT)
687 			bdl = (buf[3]);
688 		else
689 			bdl = (buf[6] << 8) | (buf[7]);
690 
691 		if (!bdl)
692 			goto after_mode_select;
693 
694 		if (cdb[0] == MODE_SELECT)
695 			blocksize = (buf[9] << 16) | (buf[10] << 8) |
696 					(buf[11]);
697 		else
698 			blocksize = (buf[13] << 16) | (buf[14] << 8) |
699 					(buf[15]);
700 
701 		sd->sector_size = blocksize;
702 	}
703 after_mode_select:
704 
705 	if (sense_buffer && (status_byte(result) & CHECK_CONDITION)) {
706 		memcpy(sense_buffer, pt->pscsi_sense, TRANSPORT_SENSE_BUFFER);
707 		cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
708 	}
709 }
710 
711 enum {
712 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
713 	Opt_scsi_lun_id, Opt_err
714 };
715 
716 static match_table_t tokens = {
717 	{Opt_scsi_host_id, "scsi_host_id=%d"},
718 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
719 	{Opt_scsi_target_id, "scsi_target_id=%d"},
720 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
721 	{Opt_err, NULL}
722 };
723 
724 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
725 		const char *page, ssize_t count)
726 {
727 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
728 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
729 	char *orig, *ptr, *opts;
730 	substring_t args[MAX_OPT_ARGS];
731 	int ret = 0, arg, token;
732 
733 	opts = kstrdup(page, GFP_KERNEL);
734 	if (!opts)
735 		return -ENOMEM;
736 
737 	orig = opts;
738 
739 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
740 		if (!*ptr)
741 			continue;
742 
743 		token = match_token(ptr, tokens, args);
744 		switch (token) {
745 		case Opt_scsi_host_id:
746 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
747 				pr_err("PSCSI[%d]: Unable to accept"
748 					" scsi_host_id while phv_mode =="
749 					" PHV_LLD_SCSI_HOST_NO\n",
750 					phv->phv_host_id);
751 				ret = -EINVAL;
752 				goto out;
753 			}
754 			ret = match_int(args, &arg);
755 			if (ret)
756 				goto out;
757 			pdv->pdv_host_id = arg;
758 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
759 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
760 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
761 			break;
762 		case Opt_scsi_channel_id:
763 			ret = match_int(args, &arg);
764 			if (ret)
765 				goto out;
766 			pdv->pdv_channel_id = arg;
767 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
768 				" ID: %d\n",  phv->phv_host_id,
769 				pdv->pdv_channel_id);
770 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
771 			break;
772 		case Opt_scsi_target_id:
773 			ret = match_int(args, &arg);
774 			if (ret)
775 				goto out;
776 			pdv->pdv_target_id = arg;
777 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
778 				" ID: %d\n", phv->phv_host_id,
779 				pdv->pdv_target_id);
780 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
781 			break;
782 		case Opt_scsi_lun_id:
783 			ret = match_int(args, &arg);
784 			if (ret)
785 				goto out;
786 			pdv->pdv_lun_id = arg;
787 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
788 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
789 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
790 			break;
791 		default:
792 			break;
793 		}
794 	}
795 
796 out:
797 	kfree(orig);
798 	return (!ret) ? count : ret;
799 }
800 
801 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
802 {
803 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
804 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
805 	struct scsi_device *sd = pdv->pdv_sd;
806 	unsigned char host_id[16];
807 	ssize_t bl;
808 	int i;
809 
810 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
811 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
812 	else
813 		snprintf(host_id, 16, "PHBA Mode");
814 
815 	bl = sprintf(b, "SCSI Device Bus Location:"
816 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
817 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
818 		host_id);
819 
820 	if (sd) {
821 		bl += sprintf(b + bl, "        ");
822 		bl += sprintf(b + bl, "Vendor: ");
823 		for (i = 0; i < 8; i++) {
824 			if (ISPRINT(sd->vendor[i]))   /* printable character? */
825 				bl += sprintf(b + bl, "%c", sd->vendor[i]);
826 			else
827 				bl += sprintf(b + bl, " ");
828 		}
829 		bl += sprintf(b + bl, " Model: ");
830 		for (i = 0; i < 16; i++) {
831 			if (ISPRINT(sd->model[i]))   /* printable character ? */
832 				bl += sprintf(b + bl, "%c", sd->model[i]);
833 			else
834 				bl += sprintf(b + bl, " ");
835 		}
836 		bl += sprintf(b + bl, " Rev: ");
837 		for (i = 0; i < 4; i++) {
838 			if (ISPRINT(sd->rev[i]))   /* printable character ? */
839 				bl += sprintf(b + bl, "%c", sd->rev[i]);
840 			else
841 				bl += sprintf(b + bl, " ");
842 		}
843 		bl += sprintf(b + bl, "\n");
844 	}
845 	return bl;
846 }
847 
848 static void pscsi_bi_endio(struct bio *bio, int error)
849 {
850 	bio_put(bio);
851 }
852 
853 static inline struct bio *pscsi_get_bio(int nr_vecs)
854 {
855 	struct bio *bio;
856 	/*
857 	 * Use bio_malloc() following the comment in for bio -> struct request
858 	 * in block/blk-core.c:blk_make_request()
859 	 */
860 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
861 	if (!bio) {
862 		pr_err("PSCSI: bio_kmalloc() failed\n");
863 		return NULL;
864 	}
865 	bio->bi_end_io = pscsi_bi_endio;
866 
867 	return bio;
868 }
869 
870 static sense_reason_t
871 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
872 		enum dma_data_direction data_direction, struct bio **hbio)
873 {
874 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
875 	struct bio *bio = NULL, *tbio = NULL;
876 	struct page *page;
877 	struct scatterlist *sg;
878 	u32 data_len = cmd->data_length, i, len, bytes, off;
879 	int nr_pages = (cmd->data_length + sgl[0].offset +
880 			PAGE_SIZE - 1) >> PAGE_SHIFT;
881 	int nr_vecs = 0, rc;
882 	int rw = (data_direction == DMA_TO_DEVICE);
883 
884 	*hbio = NULL;
885 
886 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
887 
888 	for_each_sg(sgl, sg, sgl_nents, i) {
889 		page = sg_page(sg);
890 		off = sg->offset;
891 		len = sg->length;
892 
893 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
894 			page, len, off);
895 
896 		/*
897 		 * We only have one page of data in each sg element,
898 		 * we can not cross a page boundary.
899 		 */
900 		if (off + len > PAGE_SIZE)
901 			goto fail;
902 
903 		if (len > 0 && data_len > 0) {
904 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
905 			bytes = min(bytes, data_len);
906 
907 			if (!bio) {
908 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
909 				nr_pages -= nr_vecs;
910 				/*
911 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
912 				 */
913 				bio = pscsi_get_bio(nr_vecs);
914 				if (!bio)
915 					goto fail;
916 
917 				if (rw)
918 					bio->bi_rw |= REQ_WRITE;
919 
920 				pr_debug("PSCSI: Allocated bio: %p,"
921 					" dir: %s nr_vecs: %d\n", bio,
922 					(rw) ? "rw" : "r", nr_vecs);
923 				/*
924 				 * Set *hbio pointer to handle the case:
925 				 * nr_pages > BIO_MAX_PAGES, where additional
926 				 * bios need to be added to complete a given
927 				 * command.
928 				 */
929 				if (!*hbio)
930 					*hbio = tbio = bio;
931 				else
932 					tbio = tbio->bi_next = bio;
933 			}
934 
935 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
936 				" bio: %p page: %p len: %d off: %d\n", i, bio,
937 				page, len, off);
938 
939 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
940 					bio, page, bytes, off);
941 			if (rc != bytes)
942 				goto fail;
943 
944 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
945 				bio->bi_vcnt, nr_vecs);
946 
947 			if (bio->bi_vcnt > nr_vecs) {
948 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
949 					" %d i: %d bio: %p, allocating another"
950 					" bio\n", bio->bi_vcnt, i, bio);
951 				/*
952 				 * Clear the pointer so that another bio will
953 				 * be allocated with pscsi_get_bio() above, the
954 				 * current bio has already been set *tbio and
955 				 * bio->bi_next.
956 				 */
957 				bio = NULL;
958 			}
959 
960 			data_len -= bytes;
961 		}
962 	}
963 
964 	return 0;
965 fail:
966 	while (*hbio) {
967 		bio = *hbio;
968 		*hbio = (*hbio)->bi_next;
969 		bio_endio(bio, 0);	/* XXX: should be error */
970 	}
971 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
972 }
973 
974 static sense_reason_t
975 pscsi_parse_cdb(struct se_cmd *cmd)
976 {
977 	if (cmd->se_cmd_flags & SCF_BIDI)
978 		return TCM_UNSUPPORTED_SCSI_OPCODE;
979 
980 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
981 }
982 
983 static sense_reason_t
984 pscsi_execute_cmd(struct se_cmd *cmd)
985 {
986 	struct scatterlist *sgl = cmd->t_data_sg;
987 	u32 sgl_nents = cmd->t_data_nents;
988 	enum dma_data_direction data_direction = cmd->data_direction;
989 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
990 	struct pscsi_plugin_task *pt;
991 	struct request *req;
992 	struct bio *hbio;
993 	sense_reason_t ret;
994 
995 	/*
996 	 * Dynamically alloc cdb space, since it may be larger than
997 	 * TCM_MAX_COMMAND_SIZE
998 	 */
999 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
1000 	if (!pt) {
1001 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1002 	}
1003 	cmd->priv = pt;
1004 
1005 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
1006 		scsi_command_size(cmd->t_task_cdb));
1007 
1008 	if (!sgl) {
1009 		req = blk_get_request(pdv->pdv_sd->request_queue,
1010 				(data_direction == DMA_TO_DEVICE),
1011 				GFP_KERNEL);
1012 		if (IS_ERR(req)) {
1013 			pr_err("PSCSI: blk_get_request() failed\n");
1014 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1015 			goto fail;
1016 		}
1017 
1018 		blk_rq_set_block_pc(req);
1019 	} else {
1020 		BUG_ON(!cmd->data_length);
1021 
1022 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, data_direction, &hbio);
1023 		if (ret)
1024 			goto fail;
1025 
1026 		req = blk_make_request(pdv->pdv_sd->request_queue, hbio,
1027 				       GFP_KERNEL);
1028 		if (IS_ERR(req)) {
1029 			pr_err("pSCSI: blk_make_request() failed\n");
1030 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1031 			goto fail_free_bio;
1032 		}
1033 	}
1034 
1035 	req->end_io = pscsi_req_done;
1036 	req->end_io_data = cmd;
1037 	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
1038 	req->cmd = &pt->pscsi_cdb[0];
1039 	req->sense = &pt->pscsi_sense[0];
1040 	req->sense_len = 0;
1041 	if (pdv->pdv_sd->type == TYPE_DISK)
1042 		req->timeout = PS_TIMEOUT_DISK;
1043 	else
1044 		req->timeout = PS_TIMEOUT_OTHER;
1045 	req->retries = PS_RETRY;
1046 
1047 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1048 			(cmd->sam_task_attr == TCM_HEAD_TAG),
1049 			pscsi_req_done);
1050 
1051 	return 0;
1052 
1053 fail_free_bio:
1054 	while (hbio) {
1055 		struct bio *bio = hbio;
1056 		hbio = hbio->bi_next;
1057 		bio_endio(bio, 0);	/* XXX: should be error */
1058 	}
1059 	ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1060 fail:
1061 	kfree(pt);
1062 	return ret;
1063 }
1064 
1065 /*	pscsi_get_device_type():
1066  *
1067  *
1068  */
1069 static u32 pscsi_get_device_type(struct se_device *dev)
1070 {
1071 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1072 	struct scsi_device *sd = pdv->pdv_sd;
1073 
1074 	return (sd) ? sd->type : TYPE_NO_LUN;
1075 }
1076 
1077 static sector_t pscsi_get_blocks(struct se_device *dev)
1078 {
1079 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1080 
1081 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1082 		return pdv->pdv_bd->bd_part->nr_sects;
1083 
1084 	dump_stack();
1085 	return 0;
1086 }
1087 
1088 static void pscsi_req_done(struct request *req, int uptodate)
1089 {
1090 	struct se_cmd *cmd = req->end_io_data;
1091 	struct pscsi_plugin_task *pt = cmd->priv;
1092 
1093 	pt->pscsi_result = req->errors;
1094 	pt->pscsi_resid = req->resid_len;
1095 
1096 	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
1097 	if (cmd->scsi_status) {
1098 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1099 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1100 			pt->pscsi_result);
1101 	}
1102 
1103 	switch (host_byte(pt->pscsi_result)) {
1104 	case DID_OK:
1105 		target_complete_cmd(cmd, cmd->scsi_status);
1106 		break;
1107 	default:
1108 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1109 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1110 			pt->pscsi_result);
1111 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1112 		break;
1113 	}
1114 
1115 	__blk_put_request(req->q, req);
1116 	kfree(pt);
1117 }
1118 
1119 DEF_TB_DEV_ATTRIB_RO(pscsi, hw_pi_prot_type);
1120 TB_DEV_ATTR_RO(pscsi, hw_pi_prot_type);
1121 
1122 DEF_TB_DEV_ATTRIB_RO(pscsi, hw_block_size);
1123 TB_DEV_ATTR_RO(pscsi, hw_block_size);
1124 
1125 DEF_TB_DEV_ATTRIB_RO(pscsi, hw_max_sectors);
1126 TB_DEV_ATTR_RO(pscsi, hw_max_sectors);
1127 
1128 DEF_TB_DEV_ATTRIB_RO(pscsi, hw_queue_depth);
1129 TB_DEV_ATTR_RO(pscsi, hw_queue_depth);
1130 
1131 static struct configfs_attribute *pscsi_backend_dev_attrs[] = {
1132 	&pscsi_dev_attrib_hw_pi_prot_type.attr,
1133 	&pscsi_dev_attrib_hw_block_size.attr,
1134 	&pscsi_dev_attrib_hw_max_sectors.attr,
1135 	&pscsi_dev_attrib_hw_queue_depth.attr,
1136 	NULL,
1137 };
1138 
1139 static struct se_subsystem_api pscsi_template = {
1140 	.name			= "pscsi",
1141 	.owner			= THIS_MODULE,
1142 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH,
1143 	.attach_hba		= pscsi_attach_hba,
1144 	.detach_hba		= pscsi_detach_hba,
1145 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1146 	.alloc_device		= pscsi_alloc_device,
1147 	.configure_device	= pscsi_configure_device,
1148 	.free_device		= pscsi_free_device,
1149 	.transport_complete	= pscsi_transport_complete,
1150 	.parse_cdb		= pscsi_parse_cdb,
1151 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1152 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1153 	.get_device_type	= pscsi_get_device_type,
1154 	.get_blocks		= pscsi_get_blocks,
1155 };
1156 
1157 static int __init pscsi_module_init(void)
1158 {
1159 	struct target_backend_cits *tbc = &pscsi_template.tb_cits;
1160 
1161 	target_core_setup_sub_cits(&pscsi_template);
1162 	tbc->tb_dev_attrib_cit.ct_attrs = pscsi_backend_dev_attrs;
1163 
1164 	return transport_subsystem_register(&pscsi_template);
1165 }
1166 
1167 static void __exit pscsi_module_exit(void)
1168 {
1169 	transport_subsystem_release(&pscsi_template);
1170 }
1171 
1172 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1173 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1174 MODULE_LICENSE("GPL");
1175 
1176 module_init(pscsi_module_init);
1177 module_exit(pscsi_module_exit);
1178