1 /*******************************************************************************
2  * Filename:  target_core_pscsi.c
3  *
4  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
5  *
6  * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
7  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
8  * Copyright (c) 2007-2010 Rising Tide Systems
9  * Copyright (c) 2008-2010 Linux-iSCSI.org
10  *
11  * Nicholas A. Bellinger <nab@kernel.org>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26  *
27  ******************************************************************************/
28 
29 #include <linux/version.h>
30 #include <linux/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
33 #include <linux/blkdev.h>
34 #include <linux/blk_types.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/genhd.h>
38 #include <linux/cdrom.h>
39 #include <linux/file.h>
40 #include <scsi/scsi.h>
41 #include <scsi/scsi_device.h>
42 #include <scsi/scsi_cmnd.h>
43 #include <scsi/scsi_host.h>
44 #include <scsi/libsas.h> /* For TASK_ATTR_* */
45 
46 #include <target/target_core_base.h>
47 #include <target/target_core_device.h>
48 #include <target/target_core_transport.h>
49 
50 #include "target_core_pscsi.h"
51 
52 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
53 
54 static struct se_subsystem_api pscsi_template;
55 
56 static void pscsi_req_done(struct request *, int);
57 
58 /*	pscsi_get_sh():
59  *
60  *
61  */
62 static struct Scsi_Host *pscsi_get_sh(u32 host_no)
63 {
64 	struct Scsi_Host *sh = NULL;
65 
66 	sh = scsi_host_lookup(host_no);
67 	if (IS_ERR(sh)) {
68 		printk(KERN_ERR "Unable to locate SCSI HBA with Host ID:"
69 				" %u\n", host_no);
70 		return NULL;
71 	}
72 
73 	return sh;
74 }
75 
76 /*	pscsi_attach_hba():
77  *
78  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
79  *	from the passed SCSI Host ID.
80  */
81 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
82 {
83 	int hba_depth;
84 	struct pscsi_hba_virt *phv;
85 
86 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
87 	if (!(phv)) {
88 		printk(KERN_ERR "Unable to allocate struct pscsi_hba_virt\n");
89 		return -1;
90 	}
91 	phv->phv_host_id = host_id;
92 	phv->phv_mode = PHV_VIRUTAL_HOST_ID;
93 	hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
94 	atomic_set(&hba->left_queue_depth, hba_depth);
95 	atomic_set(&hba->max_queue_depth, hba_depth);
96 
97 	hba->hba_ptr = (void *)phv;
98 
99 	printk(KERN_INFO "CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
100 		" Generic Target Core Stack %s\n", hba->hba_id,
101 		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
102 	printk(KERN_INFO "CORE_HBA[%d] - Attached SCSI HBA to Generic"
103 		" Target Core with TCQ Depth: %d\n", hba->hba_id,
104 		atomic_read(&hba->max_queue_depth));
105 
106 	return 0;
107 }
108 
109 static void pscsi_detach_hba(struct se_hba *hba)
110 {
111 	struct pscsi_hba_virt *phv = hba->hba_ptr;
112 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
113 
114 	if (scsi_host) {
115 		scsi_host_put(scsi_host);
116 
117 		printk(KERN_INFO "CORE_HBA[%d] - Detached SCSI HBA: %s from"
118 			" Generic Target Core\n", hba->hba_id,
119 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
120 			"Unknown");
121 	} else
122 		printk(KERN_INFO "CORE_HBA[%d] - Detached Virtual SCSI HBA"
123 			" from Generic Target Core\n", hba->hba_id);
124 
125 	kfree(phv);
126 	hba->hba_ptr = NULL;
127 }
128 
129 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
130 {
131 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
132 	struct Scsi_Host *sh = phv->phv_lld_host;
133 	int hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
134 	/*
135 	 * Release the struct Scsi_Host
136 	 */
137 	if (!(mode_flag)) {
138 		if (!(sh))
139 			return 0;
140 
141 		phv->phv_lld_host = NULL;
142 		phv->phv_mode = PHV_VIRUTAL_HOST_ID;
143 		atomic_set(&hba->left_queue_depth, hba_depth);
144 		atomic_set(&hba->max_queue_depth, hba_depth);
145 
146 		printk(KERN_INFO "CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
147 			" %s\n", hba->hba_id, (sh->hostt->name) ?
148 			(sh->hostt->name) : "Unknown");
149 
150 		scsi_host_put(sh);
151 		return 0;
152 	}
153 	/*
154 	 * Otherwise, locate struct Scsi_Host from the original passed
155 	 * pSCSI Host ID and enable for phba mode
156 	 */
157 	sh = pscsi_get_sh(phv->phv_host_id);
158 	if (!(sh)) {
159 		printk(KERN_ERR "pSCSI: Unable to locate SCSI Host for"
160 			" phv_host_id: %d\n", phv->phv_host_id);
161 		return -1;
162 	}
163 	/*
164 	 * Usually the SCSI LLD will use the hostt->can_queue value to define
165 	 * its HBA TCQ depth.  Some other drivers (like 2.6 megaraid) don't set
166 	 * this at all and set sh->can_queue at runtime.
167 	 */
168 	hba_depth = (sh->hostt->can_queue > sh->can_queue) ?
169 		sh->hostt->can_queue : sh->can_queue;
170 
171 	atomic_set(&hba->left_queue_depth, hba_depth);
172 	atomic_set(&hba->max_queue_depth, hba_depth);
173 
174 	phv->phv_lld_host = sh;
175 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
176 
177 	printk(KERN_INFO "CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
178 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
179 
180 	return 1;
181 }
182 
183 static void pscsi_tape_read_blocksize(struct se_device *dev,
184 		struct scsi_device *sdev)
185 {
186 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
187 	int ret;
188 
189 	buf = kzalloc(12, GFP_KERNEL);
190 	if (!buf)
191 		return;
192 
193 	memset(cdb, 0, MAX_COMMAND_SIZE);
194 	cdb[0] = MODE_SENSE;
195 	cdb[4] = 0x0c; /* 12 bytes */
196 
197 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
198 			HZ, 1, NULL);
199 	if (ret)
200 		goto out_free;
201 
202 	/*
203 	 * If MODE_SENSE still returns zero, set the default value to 1024.
204 	 */
205 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
206 	if (!sdev->sector_size)
207 		sdev->sector_size = 1024;
208 out_free:
209 	kfree(buf);
210 }
211 
212 static void
213 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
214 {
215 	unsigned char *buf;
216 
217 	if (sdev->inquiry_len < INQUIRY_LEN)
218 		return;
219 
220 	buf = sdev->inquiry;
221 	if (!buf)
222 		return;
223 	/*
224 	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
225 	 */
226 	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
227 	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
228 	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
229 }
230 
231 static int
232 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
233 {
234 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
235 	int ret;
236 
237 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
238 	if (!buf)
239 		return -1;
240 
241 	memset(cdb, 0, MAX_COMMAND_SIZE);
242 	cdb[0] = INQUIRY;
243 	cdb[1] = 0x01; /* Query VPD */
244 	cdb[2] = 0x80; /* Unit Serial Number */
245 	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
246 	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
247 
248 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
249 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
250 	if (ret)
251 		goto out_free;
252 
253 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
254 
255 	wwn->t10_sub_dev->su_dev_flags |= SDF_FIRMWARE_VPD_UNIT_SERIAL;
256 
257 	kfree(buf);
258 	return 0;
259 
260 out_free:
261 	kfree(buf);
262 	return -1;
263 }
264 
265 static void
266 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
267 		struct t10_wwn *wwn)
268 {
269 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
270 	int ident_len, page_len, off = 4, ret;
271 	struct t10_vpd *vpd;
272 
273 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
274 	if (!buf)
275 		return;
276 
277 	memset(cdb, 0, MAX_COMMAND_SIZE);
278 	cdb[0] = INQUIRY;
279 	cdb[1] = 0x01; /* Query VPD */
280 	cdb[2] = 0x83; /* Device Identifier */
281 	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
282 	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
283 
284 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
285 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
286 			      NULL, HZ, 1, NULL);
287 	if (ret)
288 		goto out;
289 
290 	page_len = (buf[2] << 8) | buf[3];
291 	while (page_len > 0) {
292 		/* Grab a pointer to the Identification descriptor */
293 		page_83 = &buf[off];
294 		ident_len = page_83[3];
295 		if (!ident_len) {
296 			printk(KERN_ERR "page_83[3]: identifier"
297 					" length zero!\n");
298 			break;
299 		}
300 		printk(KERN_INFO "T10 VPD Identifer Length: %d\n", ident_len);
301 
302 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
303 		if (!vpd) {
304 			printk(KERN_ERR "Unable to allocate memory for"
305 					" struct t10_vpd\n");
306 			goto out;
307 		}
308 		INIT_LIST_HEAD(&vpd->vpd_list);
309 
310 		transport_set_vpd_proto_id(vpd, page_83);
311 		transport_set_vpd_assoc(vpd, page_83);
312 
313 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
314 			off += (ident_len + 4);
315 			page_len -= (ident_len + 4);
316 			kfree(vpd);
317 			continue;
318 		}
319 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
320 			off += (ident_len + 4);
321 			page_len -= (ident_len + 4);
322 			kfree(vpd);
323 			continue;
324 		}
325 
326 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
327 		off += (ident_len + 4);
328 		page_len -= (ident_len + 4);
329 	}
330 
331 out:
332 	kfree(buf);
333 }
334 
335 /*	pscsi_add_device_to_list():
336  *
337  *
338  */
339 static struct se_device *pscsi_add_device_to_list(
340 	struct se_hba *hba,
341 	struct se_subsystem_dev *se_dev,
342 	struct pscsi_dev_virt *pdv,
343 	struct scsi_device *sd,
344 	int dev_flags)
345 {
346 	struct se_device *dev;
347 	struct se_dev_limits dev_limits;
348 	struct request_queue *q;
349 	struct queue_limits *limits;
350 
351 	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
352 
353 	if (!sd->queue_depth) {
354 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
355 
356 		printk(KERN_ERR "Set broken SCSI Device %d:%d:%d"
357 			" queue_depth to %d\n", sd->channel, sd->id,
358 				sd->lun, sd->queue_depth);
359 	}
360 	/*
361 	 * Setup the local scope queue_limits from struct request_queue->limits
362 	 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
363 	 */
364 	q = sd->request_queue;
365 	limits = &dev_limits.limits;
366 	limits->logical_block_size = sd->sector_size;
367 	limits->max_hw_sectors = (sd->host->max_sectors > queue_max_hw_sectors(q)) ?
368 				  queue_max_hw_sectors(q) : sd->host->max_sectors;
369 	limits->max_sectors = (sd->host->max_sectors > queue_max_sectors(q)) ?
370 				  queue_max_sectors(q) : sd->host->max_sectors;
371 	dev_limits.hw_queue_depth = sd->queue_depth;
372 	dev_limits.queue_depth = sd->queue_depth;
373 	/*
374 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
375 	 */
376 	pscsi_set_inquiry_info(sd, &se_dev->t10_wwn);
377 
378 	/*
379 	 * Set the pointer pdv->pdv_sd to from passed struct scsi_device,
380 	 * which has already been referenced with Linux SCSI code with
381 	 * scsi_device_get() in this file's pscsi_create_virtdevice().
382 	 *
383 	 * The passthrough operations called by the transport_add_device_*
384 	 * function below will require this pointer to be set for passthroug
385 	 *  ops.
386 	 *
387 	 * For the shutdown case in pscsi_free_device(), this struct
388 	 * scsi_device  reference is released with Linux SCSI code
389 	 * scsi_device_put() and the pdv->pdv_sd cleared.
390 	 */
391 	pdv->pdv_sd = sd;
392 
393 	dev = transport_add_device_to_core_hba(hba, &pscsi_template,
394 				se_dev, dev_flags, (void *)pdv,
395 				&dev_limits, NULL, NULL);
396 	if (!(dev)) {
397 		pdv->pdv_sd = NULL;
398 		return NULL;
399 	}
400 
401 	/*
402 	 * Locate VPD WWN Information used for various purposes within
403 	 * the Storage Engine.
404 	 */
405 	if (!pscsi_get_inquiry_vpd_serial(sd, &se_dev->t10_wwn)) {
406 		/*
407 		 * If VPD Unit Serial returned GOOD status, try
408 		 * VPD Device Identification page (0x83).
409 		 */
410 		pscsi_get_inquiry_vpd_device_ident(sd, &se_dev->t10_wwn);
411 	}
412 
413 	/*
414 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
415 	 */
416 	if (sd->type == TYPE_TAPE)
417 		pscsi_tape_read_blocksize(dev, sd);
418 	return dev;
419 }
420 
421 static void *pscsi_allocate_virtdevice(struct se_hba *hba, const char *name)
422 {
423 	struct pscsi_dev_virt *pdv;
424 
425 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
426 	if (!(pdv)) {
427 		printk(KERN_ERR "Unable to allocate memory for struct pscsi_dev_virt\n");
428 		return NULL;
429 	}
430 	pdv->pdv_se_hba = hba;
431 
432 	printk(KERN_INFO "PSCSI: Allocated pdv: %p for %s\n", pdv, name);
433 	return (void *)pdv;
434 }
435 
436 /*
437  * Called with struct Scsi_Host->host_lock called.
438  */
439 static struct se_device *pscsi_create_type_disk(
440 	struct scsi_device *sd,
441 	struct pscsi_dev_virt *pdv,
442 	struct se_subsystem_dev *se_dev,
443 	struct se_hba *hba)
444 	__releases(sh->host_lock)
445 {
446 	struct se_device *dev;
447 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
448 	struct Scsi_Host *sh = sd->host;
449 	struct block_device *bd;
450 	u32 dev_flags = 0;
451 
452 	if (scsi_device_get(sd)) {
453 		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
454 			sh->host_no, sd->channel, sd->id, sd->lun);
455 		spin_unlock_irq(sh->host_lock);
456 		return NULL;
457 	}
458 	spin_unlock_irq(sh->host_lock);
459 	/*
460 	 * Claim exclusive struct block_device access to struct scsi_device
461 	 * for TYPE_DISK using supplied udev_path
462 	 */
463 	bd = blkdev_get_by_path(se_dev->se_dev_udev_path,
464 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
465 	if (IS_ERR(bd)) {
466 		printk(KERN_ERR "pSCSI: blkdev_get_by_path() failed\n");
467 		scsi_device_put(sd);
468 		return NULL;
469 	}
470 	pdv->pdv_bd = bd;
471 
472 	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
473 	if (!(dev)) {
474 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
475 		scsi_device_put(sd);
476 		return NULL;
477 	}
478 	printk(KERN_INFO "CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%d\n",
479 		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
480 
481 	return dev;
482 }
483 
484 /*
485  * Called with struct Scsi_Host->host_lock called.
486  */
487 static struct se_device *pscsi_create_type_rom(
488 	struct scsi_device *sd,
489 	struct pscsi_dev_virt *pdv,
490 	struct se_subsystem_dev *se_dev,
491 	struct se_hba *hba)
492 	__releases(sh->host_lock)
493 {
494 	struct se_device *dev;
495 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
496 	struct Scsi_Host *sh = sd->host;
497 	u32 dev_flags = 0;
498 
499 	if (scsi_device_get(sd)) {
500 		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
501 			sh->host_no, sd->channel, sd->id, sd->lun);
502 		spin_unlock_irq(sh->host_lock);
503 		return NULL;
504 	}
505 	spin_unlock_irq(sh->host_lock);
506 
507 	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
508 	if (!(dev)) {
509 		scsi_device_put(sd);
510 		return NULL;
511 	}
512 	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
513 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
514 		sd->channel, sd->id, sd->lun);
515 
516 	return dev;
517 }
518 
519 /*
520  *Called with struct Scsi_Host->host_lock called.
521  */
522 static struct se_device *pscsi_create_type_other(
523 	struct scsi_device *sd,
524 	struct pscsi_dev_virt *pdv,
525 	struct se_subsystem_dev *se_dev,
526 	struct se_hba *hba)
527 	__releases(sh->host_lock)
528 {
529 	struct se_device *dev;
530 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
531 	struct Scsi_Host *sh = sd->host;
532 	u32 dev_flags = 0;
533 
534 	spin_unlock_irq(sh->host_lock);
535 	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
536 	if (!(dev))
537 		return NULL;
538 
539 	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
540 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
541 		sd->channel, sd->id, sd->lun);
542 
543 	return dev;
544 }
545 
546 static struct se_device *pscsi_create_virtdevice(
547 	struct se_hba *hba,
548 	struct se_subsystem_dev *se_dev,
549 	void *p)
550 {
551 	struct pscsi_dev_virt *pdv = (struct pscsi_dev_virt *)p;
552 	struct se_device *dev;
553 	struct scsi_device *sd;
554 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
555 	struct Scsi_Host *sh = phv->phv_lld_host;
556 	int legacy_mode_enable = 0;
557 
558 	if (!(pdv)) {
559 		printk(KERN_ERR "Unable to locate struct pscsi_dev_virt"
560 				" parameter\n");
561 		return ERR_PTR(-EINVAL);
562 	}
563 	/*
564 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
565 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
566 	 */
567 	if (!(sh)) {
568 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
569 			printk(KERN_ERR "pSCSI: Unable to locate struct"
570 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
571 			return ERR_PTR(-ENODEV);
572 		}
573 		/*
574 		 * For the newer PHV_VIRUTAL_HOST_ID struct scsi_device
575 		 * reference, we enforce that udev_path has been set
576 		 */
577 		if (!(se_dev->su_dev_flags & SDF_USING_UDEV_PATH)) {
578 			printk(KERN_ERR "pSCSI: udev_path attribute has not"
579 				" been set before ENABLE=1\n");
580 			return ERR_PTR(-EINVAL);
581 		}
582 		/*
583 		 * If no scsi_host_id= was passed for PHV_VIRUTAL_HOST_ID,
584 		 * use the original TCM hba ID to reference Linux/SCSI Host No
585 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
586 		 */
587 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
588 			spin_lock(&hba->device_lock);
589 			if (!(list_empty(&hba->hba_dev_list))) {
590 				printk(KERN_ERR "pSCSI: Unable to set hba_mode"
591 					" with active devices\n");
592 				spin_unlock(&hba->device_lock);
593 				return ERR_PTR(-EEXIST);
594 			}
595 			spin_unlock(&hba->device_lock);
596 
597 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
598 				return ERR_PTR(-ENODEV);
599 
600 			legacy_mode_enable = 1;
601 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
602 			sh = phv->phv_lld_host;
603 		} else {
604 			sh = pscsi_get_sh(pdv->pdv_host_id);
605 			if (!(sh)) {
606 				printk(KERN_ERR "pSCSI: Unable to locate"
607 					" pdv_host_id: %d\n", pdv->pdv_host_id);
608 				return ERR_PTR(-ENODEV);
609 			}
610 		}
611 	} else {
612 		if (phv->phv_mode == PHV_VIRUTAL_HOST_ID) {
613 			printk(KERN_ERR "pSCSI: PHV_VIRUTAL_HOST_ID set while"
614 				" struct Scsi_Host exists\n");
615 			return ERR_PTR(-EEXIST);
616 		}
617 	}
618 
619 	spin_lock_irq(sh->host_lock);
620 	list_for_each_entry(sd, &sh->__devices, siblings) {
621 		if ((pdv->pdv_channel_id != sd->channel) ||
622 		    (pdv->pdv_target_id != sd->id) ||
623 		    (pdv->pdv_lun_id != sd->lun))
624 			continue;
625 		/*
626 		 * Functions will release the held struct scsi_host->host_lock
627 		 * before calling calling pscsi_add_device_to_list() to register
628 		 * struct scsi_device with target_core_mod.
629 		 */
630 		switch (sd->type) {
631 		case TYPE_DISK:
632 			dev = pscsi_create_type_disk(sd, pdv, se_dev, hba);
633 			break;
634 		case TYPE_ROM:
635 			dev = pscsi_create_type_rom(sd, pdv, se_dev, hba);
636 			break;
637 		default:
638 			dev = pscsi_create_type_other(sd, pdv, se_dev, hba);
639 			break;
640 		}
641 
642 		if (!(dev)) {
643 			if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
644 				scsi_host_put(sh);
645 			else if (legacy_mode_enable) {
646 				pscsi_pmode_enable_hba(hba, 0);
647 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
648 			}
649 			pdv->pdv_sd = NULL;
650 			return ERR_PTR(-ENODEV);
651 		}
652 		return dev;
653 	}
654 	spin_unlock_irq(sh->host_lock);
655 
656 	printk(KERN_ERR "pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
657 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
658 
659 	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
660 		scsi_host_put(sh);
661 	else if (legacy_mode_enable) {
662 		pscsi_pmode_enable_hba(hba, 0);
663 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
664 	}
665 
666 	return ERR_PTR(-ENODEV);
667 }
668 
669 /*	pscsi_free_device(): (Part of se_subsystem_api_t template)
670  *
671  *
672  */
673 static void pscsi_free_device(void *p)
674 {
675 	struct pscsi_dev_virt *pdv = p;
676 	struct pscsi_hba_virt *phv = pdv->pdv_se_hba->hba_ptr;
677 	struct scsi_device *sd = pdv->pdv_sd;
678 
679 	if (sd) {
680 		/*
681 		 * Release exclusive pSCSI internal struct block_device claim for
682 		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
683 		 */
684 		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
685 			blkdev_put(pdv->pdv_bd,
686 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
687 			pdv->pdv_bd = NULL;
688 		}
689 		/*
690 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
691 		 * to struct Scsi_Host now.
692 		 */
693 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
694 		    (phv->phv_lld_host != NULL))
695 			scsi_host_put(phv->phv_lld_host);
696 
697 		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
698 			scsi_device_put(sd);
699 
700 		pdv->pdv_sd = NULL;
701 	}
702 
703 	kfree(pdv);
704 }
705 
706 static inline struct pscsi_plugin_task *PSCSI_TASK(struct se_task *task)
707 {
708 	return container_of(task, struct pscsi_plugin_task, pscsi_task);
709 }
710 
711 
712 /*	pscsi_transport_complete():
713  *
714  *
715  */
716 static int pscsi_transport_complete(struct se_task *task)
717 {
718 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
719 	struct scsi_device *sd = pdv->pdv_sd;
720 	int result;
721 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
722 	unsigned char *cdb = &pt->pscsi_cdb[0];
723 
724 	result = pt->pscsi_result;
725 	/*
726 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
727 	 * forced.
728 	 */
729 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
730 	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
731 		if (!TASK_CMD(task)->se_deve)
732 			goto after_mode_sense;
733 
734 		if (TASK_CMD(task)->se_deve->lun_flags &
735 				TRANSPORT_LUNFLAGS_READ_ONLY) {
736 			unsigned char *buf = (unsigned char *)
737 				T_TASK(task->task_se_cmd)->t_task_buf;
738 
739 			if (cdb[0] == MODE_SENSE_10) {
740 				if (!(buf[3] & 0x80))
741 					buf[3] |= 0x80;
742 			} else {
743 				if (!(buf[2] & 0x80))
744 					buf[2] |= 0x80;
745 			}
746 		}
747 	}
748 after_mode_sense:
749 
750 	if (sd->type != TYPE_TAPE)
751 		goto after_mode_select;
752 
753 	/*
754 	 * Hack to correctly obtain the initiator requested blocksize for
755 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
756 	 * struct scsi_device->sector_size will not contain the correct value
757 	 * by default, so we go ahead and set it so
758 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
759 	 * storage engine.
760 	 */
761 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
762 	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
763 		unsigned char *buf;
764 		struct scatterlist *sg = task->task_sg;
765 		u16 bdl;
766 		u32 blocksize;
767 
768 		buf = sg_virt(&sg[0]);
769 		if (!(buf)) {
770 			printk(KERN_ERR "Unable to get buf for scatterlist\n");
771 			goto after_mode_select;
772 		}
773 
774 		if (cdb[0] == MODE_SELECT)
775 			bdl = (buf[3]);
776 		else
777 			bdl = (buf[6] << 8) | (buf[7]);
778 
779 		if (!bdl)
780 			goto after_mode_select;
781 
782 		if (cdb[0] == MODE_SELECT)
783 			blocksize = (buf[9] << 16) | (buf[10] << 8) |
784 					(buf[11]);
785 		else
786 			blocksize = (buf[13] << 16) | (buf[14] << 8) |
787 					(buf[15]);
788 
789 		sd->sector_size = blocksize;
790 	}
791 after_mode_select:
792 
793 	if (status_byte(result) & CHECK_CONDITION)
794 		return 1;
795 
796 	return 0;
797 }
798 
799 static struct se_task *
800 pscsi_alloc_task(struct se_cmd *cmd)
801 {
802 	struct pscsi_plugin_task *pt;
803 	unsigned char *cdb = T_TASK(cmd)->t_task_cdb;
804 
805 	pt = kzalloc(sizeof(struct pscsi_plugin_task), GFP_KERNEL);
806 	if (!pt) {
807 		printk(KERN_ERR "Unable to allocate struct pscsi_plugin_task\n");
808 		return NULL;
809 	}
810 
811 	/*
812 	 * If TCM Core is signaling a > TCM_MAX_COMMAND_SIZE allocation,
813 	 * allocate the extended CDB buffer for per struct se_task context
814 	 * pt->pscsi_cdb now.
815 	 */
816 	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb) {
817 
818 		pt->pscsi_cdb = kzalloc(scsi_command_size(cdb), GFP_KERNEL);
819 		if (!(pt->pscsi_cdb)) {
820 			printk(KERN_ERR "pSCSI: Unable to allocate extended"
821 					" pt->pscsi_cdb\n");
822 			kfree(pt);
823 			return NULL;
824 		}
825 	} else
826 		pt->pscsi_cdb = &pt->__pscsi_cdb[0];
827 
828 	return &pt->pscsi_task;
829 }
830 
831 static inline void pscsi_blk_init_request(
832 	struct se_task *task,
833 	struct pscsi_plugin_task *pt,
834 	struct request *req,
835 	int bidi_read)
836 {
837 	/*
838 	 * Defined as "scsi command" in include/linux/blkdev.h.
839 	 */
840 	req->cmd_type = REQ_TYPE_BLOCK_PC;
841 	/*
842 	 * For the extra BIDI-COMMAND READ struct request we do not
843 	 * need to setup the remaining structure members
844 	 */
845 	if (bidi_read)
846 		return;
847 	/*
848 	 * Setup the done function pointer for struct request,
849 	 * also set the end_io_data pointer.to struct se_task.
850 	 */
851 	req->end_io = pscsi_req_done;
852 	req->end_io_data = (void *)task;
853 	/*
854 	 * Load the referenced struct se_task's SCSI CDB into
855 	 * include/linux/blkdev.h:struct request->cmd
856 	 */
857 	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
858 	req->cmd = &pt->pscsi_cdb[0];
859 	/*
860 	 * Setup pointer for outgoing sense data.
861 	 */
862 	req->sense = (void *)&pt->pscsi_sense[0];
863 	req->sense_len = 0;
864 }
865 
866 /*
867  * Used for pSCSI data payloads for all *NON* SCF_SCSI_DATA_SG_IO_CDB
868 */
869 static int pscsi_blk_get_request(struct se_task *task)
870 {
871 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
872 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
873 
874 	pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
875 			(task->task_data_direction == DMA_TO_DEVICE),
876 			GFP_KERNEL);
877 	if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
878 		printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
879 				IS_ERR(pt->pscsi_req));
880 		return PYX_TRANSPORT_LU_COMM_FAILURE;
881 	}
882 	/*
883 	 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
884 	 * and setup rq callback, CDB and sense.
885 	 */
886 	pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
887 	return 0;
888 }
889 
890 /*      pscsi_do_task(): (Part of se_subsystem_api_t template)
891  *
892  *
893  */
894 static int pscsi_do_task(struct se_task *task)
895 {
896 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
897 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
898 	/*
899 	 * Set the struct request->timeout value based on peripheral
900 	 * device type from SCSI.
901 	 */
902 	if (pdv->pdv_sd->type == TYPE_DISK)
903 		pt->pscsi_req->timeout = PS_TIMEOUT_DISK;
904 	else
905 		pt->pscsi_req->timeout = PS_TIMEOUT_OTHER;
906 
907 	pt->pscsi_req->retries = PS_RETRY;
908 	/*
909 	 * Queue the struct request into the struct scsi_device->request_queue.
910 	 * Also check for HEAD_OF_QUEUE SAM TASK attr from received se_cmd
911 	 * descriptor
912 	 */
913 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, pt->pscsi_req,
914 			(task->task_se_cmd->sam_task_attr == TASK_ATTR_HOQ),
915 			pscsi_req_done);
916 
917 	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
918 }
919 
920 static void pscsi_free_task(struct se_task *task)
921 {
922 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
923 	struct se_cmd *cmd = task->task_se_cmd;
924 
925 	/*
926 	 * Release the extended CDB allocation from pscsi_alloc_task()
927 	 * if one exists.
928 	 */
929 	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb)
930 		kfree(pt->pscsi_cdb);
931 	/*
932 	 * We do not release the bio(s) here associated with this task, as
933 	 * this is handled by bio_put() and pscsi_bi_endio().
934 	 */
935 	kfree(pt);
936 }
937 
938 enum {
939 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
940 	Opt_scsi_lun_id, Opt_err
941 };
942 
943 static match_table_t tokens = {
944 	{Opt_scsi_host_id, "scsi_host_id=%d"},
945 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
946 	{Opt_scsi_target_id, "scsi_target_id=%d"},
947 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
948 	{Opt_err, NULL}
949 };
950 
951 static ssize_t pscsi_set_configfs_dev_params(struct se_hba *hba,
952 	struct se_subsystem_dev *se_dev,
953 	const char *page,
954 	ssize_t count)
955 {
956 	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
957 	struct pscsi_hba_virt *phv = hba->hba_ptr;
958 	char *orig, *ptr, *opts;
959 	substring_t args[MAX_OPT_ARGS];
960 	int ret = 0, arg, token;
961 
962 	opts = kstrdup(page, GFP_KERNEL);
963 	if (!opts)
964 		return -ENOMEM;
965 
966 	orig = opts;
967 
968 	while ((ptr = strsep(&opts, ",")) != NULL) {
969 		if (!*ptr)
970 			continue;
971 
972 		token = match_token(ptr, tokens, args);
973 		switch (token) {
974 		case Opt_scsi_host_id:
975 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
976 				printk(KERN_ERR "PSCSI[%d]: Unable to accept"
977 					" scsi_host_id while phv_mode =="
978 					" PHV_LLD_SCSI_HOST_NO\n",
979 					phv->phv_host_id);
980 				ret = -EINVAL;
981 				goto out;
982 			}
983 			match_int(args, &arg);
984 			pdv->pdv_host_id = arg;
985 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Host ID:"
986 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
987 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
988 			break;
989 		case Opt_scsi_channel_id:
990 			match_int(args, &arg);
991 			pdv->pdv_channel_id = arg;
992 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Channel"
993 				" ID: %d\n",  phv->phv_host_id,
994 				pdv->pdv_channel_id);
995 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
996 			break;
997 		case Opt_scsi_target_id:
998 			match_int(args, &arg);
999 			pdv->pdv_target_id = arg;
1000 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Target"
1001 				" ID: %d\n", phv->phv_host_id,
1002 				pdv->pdv_target_id);
1003 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
1004 			break;
1005 		case Opt_scsi_lun_id:
1006 			match_int(args, &arg);
1007 			pdv->pdv_lun_id = arg;
1008 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI LUN ID:"
1009 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
1010 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
1011 			break;
1012 		default:
1013 			break;
1014 		}
1015 	}
1016 
1017 out:
1018 	kfree(orig);
1019 	return (!ret) ? count : ret;
1020 }
1021 
1022 static ssize_t pscsi_check_configfs_dev_params(
1023 	struct se_hba *hba,
1024 	struct se_subsystem_dev *se_dev)
1025 {
1026 	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
1027 
1028 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
1029 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
1030 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
1031 		printk(KERN_ERR "Missing scsi_channel_id=, scsi_target_id= and"
1032 			" scsi_lun_id= parameters\n");
1033 		return -1;
1034 	}
1035 
1036 	return 0;
1037 }
1038 
1039 static ssize_t pscsi_show_configfs_dev_params(struct se_hba *hba,
1040 					      struct se_subsystem_dev *se_dev,
1041 					      char *b)
1042 {
1043 	struct pscsi_hba_virt *phv = hba->hba_ptr;
1044         struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
1045 	struct scsi_device *sd = pdv->pdv_sd;
1046 	unsigned char host_id[16];
1047 	ssize_t bl;
1048 	int i;
1049 
1050 	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
1051 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
1052 	else
1053 		snprintf(host_id, 16, "PHBA Mode");
1054 
1055 	bl = sprintf(b, "SCSI Device Bus Location:"
1056 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
1057 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
1058 		host_id);
1059 
1060 	if (sd) {
1061 		bl += sprintf(b + bl, "        ");
1062 		bl += sprintf(b + bl, "Vendor: ");
1063 		for (i = 0; i < 8; i++) {
1064 			if (ISPRINT(sd->vendor[i]))   /* printable character? */
1065 				bl += sprintf(b + bl, "%c", sd->vendor[i]);
1066 			else
1067 				bl += sprintf(b + bl, " ");
1068 		}
1069 		bl += sprintf(b + bl, " Model: ");
1070 		for (i = 0; i < 16; i++) {
1071 			if (ISPRINT(sd->model[i]))   /* printable character ? */
1072 				bl += sprintf(b + bl, "%c", sd->model[i]);
1073 			else
1074 				bl += sprintf(b + bl, " ");
1075 		}
1076 		bl += sprintf(b + bl, " Rev: ");
1077 		for (i = 0; i < 4; i++) {
1078 			if (ISPRINT(sd->rev[i]))   /* printable character ? */
1079 				bl += sprintf(b + bl, "%c", sd->rev[i]);
1080 			else
1081 				bl += sprintf(b + bl, " ");
1082 		}
1083 		bl += sprintf(b + bl, "\n");
1084 	}
1085 	return bl;
1086 }
1087 
1088 static void pscsi_bi_endio(struct bio *bio, int error)
1089 {
1090 	bio_put(bio);
1091 }
1092 
1093 static inline struct bio *pscsi_get_bio(struct pscsi_dev_virt *pdv, int sg_num)
1094 {
1095 	struct bio *bio;
1096 	/*
1097 	 * Use bio_malloc() following the comment in for bio -> struct request
1098 	 * in block/blk-core.c:blk_make_request()
1099 	 */
1100 	bio = bio_kmalloc(GFP_KERNEL, sg_num);
1101 	if (!(bio)) {
1102 		printk(KERN_ERR "PSCSI: bio_kmalloc() failed\n");
1103 		return NULL;
1104 	}
1105 	bio->bi_end_io = pscsi_bi_endio;
1106 
1107 	return bio;
1108 }
1109 
1110 #if 0
1111 #define DEBUG_PSCSI(x...) printk(x)
1112 #else
1113 #define DEBUG_PSCSI(x...)
1114 #endif
1115 
1116 static int __pscsi_map_task_SG(
1117 	struct se_task *task,
1118 	struct scatterlist *task_sg,
1119 	u32 task_sg_num,
1120 	int bidi_read)
1121 {
1122 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1123 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
1124 	struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
1125 	struct page *page;
1126 	struct scatterlist *sg;
1127 	u32 data_len = task->task_size, i, len, bytes, off;
1128 	int nr_pages = (task->task_size + task_sg[0].offset +
1129 			PAGE_SIZE - 1) >> PAGE_SHIFT;
1130 	int nr_vecs = 0, rc, ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
1131 	int rw = (task->task_data_direction == DMA_TO_DEVICE);
1132 
1133 	if (!task->task_size)
1134 		return 0;
1135 	/*
1136 	 * For SCF_SCSI_DATA_SG_IO_CDB, Use fs/bio.c:bio_add_page() to setup
1137 	 * the bio_vec maplist from TC< struct se_mem -> task->task_sg ->
1138 	 * struct scatterlist memory.  The struct se_task->task_sg[] currently needs
1139 	 * to be attached to struct bios for submission to Linux/SCSI using
1140 	 * struct request to struct scsi_device->request_queue.
1141 	 *
1142 	 * Note that this will be changing post v2.6.28 as Target_Core_Mod/pSCSI
1143 	 * is ported to upstream SCSI passthrough functionality that accepts
1144 	 * struct scatterlist->page_link or struct page as a paraemeter.
1145 	 */
1146 	DEBUG_PSCSI("PSCSI: nr_pages: %d\n", nr_pages);
1147 
1148 	for_each_sg(task_sg, sg, task_sg_num, i) {
1149 		page = sg_page(sg);
1150 		off = sg->offset;
1151 		len = sg->length;
1152 
1153 		DEBUG_PSCSI("PSCSI: i: %d page: %p len: %d off: %d\n", i,
1154 			page, len, off);
1155 
1156 		while (len > 0 && data_len > 0) {
1157 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
1158 			bytes = min(bytes, data_len);
1159 
1160 			if (!(bio)) {
1161 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
1162 				nr_pages -= nr_vecs;
1163 				/*
1164 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
1165 				 */
1166 				bio = pscsi_get_bio(pdv, nr_vecs);
1167 				if (!(bio))
1168 					goto fail;
1169 
1170 				if (rw)
1171 					bio->bi_rw |= REQ_WRITE;
1172 
1173 				DEBUG_PSCSI("PSCSI: Allocated bio: %p,"
1174 					" dir: %s nr_vecs: %d\n", bio,
1175 					(rw) ? "rw" : "r", nr_vecs);
1176 				/*
1177 				 * Set *hbio pointer to handle the case:
1178 				 * nr_pages > BIO_MAX_PAGES, where additional
1179 				 * bios need to be added to complete a given
1180 				 * struct se_task
1181 				 */
1182 				if (!hbio)
1183 					hbio = tbio = bio;
1184 				else
1185 					tbio = tbio->bi_next = bio;
1186 			}
1187 
1188 			DEBUG_PSCSI("PSCSI: Calling bio_add_pc_page() i: %d"
1189 				" bio: %p page: %p len: %d off: %d\n", i, bio,
1190 				page, len, off);
1191 
1192 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
1193 					bio, page, bytes, off);
1194 			if (rc != bytes)
1195 				goto fail;
1196 
1197 			DEBUG_PSCSI("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
1198 				bio->bi_vcnt, nr_vecs);
1199 
1200 			if (bio->bi_vcnt > nr_vecs) {
1201 				DEBUG_PSCSI("PSCSI: Reached bio->bi_vcnt max:"
1202 					" %d i: %d bio: %p, allocating another"
1203 					" bio\n", bio->bi_vcnt, i, bio);
1204 				/*
1205 				 * Clear the pointer so that another bio will
1206 				 * be allocated with pscsi_get_bio() above, the
1207 				 * current bio has already been set *tbio and
1208 				 * bio->bi_next.
1209 				 */
1210 				bio = NULL;
1211 			}
1212 
1213 			page++;
1214 			len -= bytes;
1215 			data_len -= bytes;
1216 			off = 0;
1217 		}
1218 	}
1219 	/*
1220 	 * Setup the primary pt->pscsi_req used for non BIDI and BIDI-COMMAND
1221 	 * primary SCSI WRITE poayload mapped for struct se_task->task_sg[]
1222 	 */
1223 	if (!(bidi_read)) {
1224 		/*
1225 		 * Starting with v2.6.31, call blk_make_request() passing in *hbio to
1226 		 * allocate the pSCSI task a struct request.
1227 		 */
1228 		pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
1229 					hbio, GFP_KERNEL);
1230 		if (!(pt->pscsi_req)) {
1231 			printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
1232 			goto fail;
1233 		}
1234 		/*
1235 		 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
1236 		 * and setup rq callback, CDB and sense.
1237 		 */
1238 		pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
1239 
1240 		return task->task_sg_num;
1241 	}
1242 	/*
1243 	 * Setup the secondary pt->pscsi_req->next_rq used for the extra BIDI-COMMAND
1244 	 * SCSI READ paylaod mapped for struct se_task->task_sg_bidi[]
1245 	 */
1246 	pt->pscsi_req->next_rq = blk_make_request(pdv->pdv_sd->request_queue,
1247 					hbio, GFP_KERNEL);
1248 	if (!(pt->pscsi_req->next_rq)) {
1249 		printk(KERN_ERR "pSCSI: blk_make_request() failed for BIDI\n");
1250 		goto fail;
1251 	}
1252 	pscsi_blk_init_request(task, pt, pt->pscsi_req->next_rq, 1);
1253 
1254 	return task->task_sg_num;
1255 fail:
1256 	while (hbio) {
1257 		bio = hbio;
1258 		hbio = hbio->bi_next;
1259 		bio->bi_next = NULL;
1260 		bio_endio(bio, 0);
1261 	}
1262 	return ret;
1263 }
1264 
1265 static int pscsi_map_task_SG(struct se_task *task)
1266 {
1267 	int ret;
1268 
1269 	/*
1270 	 * Setup the main struct request for the task->task_sg[] payload
1271 	 */
1272 
1273 	ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_num, 0);
1274 	if (ret >= 0 && task->task_sg_bidi) {
1275 		/*
1276 		 * If present, set up the extra BIDI-COMMAND SCSI READ
1277 		 * struct request and payload.
1278 		 */
1279 		ret = __pscsi_map_task_SG(task, task->task_sg_bidi,
1280 					task->task_sg_num, 1);
1281 	}
1282 
1283 	if (ret < 0)
1284 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1285 	return 0;
1286 }
1287 
1288 /*	pscsi_map_task_non_SG():
1289  *
1290  *
1291  */
1292 static int pscsi_map_task_non_SG(struct se_task *task)
1293 {
1294 	struct se_cmd *cmd = TASK_CMD(task);
1295 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1296 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
1297 	int ret = 0;
1298 
1299 	if (pscsi_blk_get_request(task) < 0)
1300 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1301 
1302 	if (!task->task_size)
1303 		return 0;
1304 
1305 	ret = blk_rq_map_kern(pdv->pdv_sd->request_queue,
1306 			pt->pscsi_req, T_TASK(cmd)->t_task_buf,
1307 			task->task_size, GFP_KERNEL);
1308 	if (ret < 0) {
1309 		printk(KERN_ERR "PSCSI: blk_rq_map_kern() failed: %d\n", ret);
1310 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1311 	}
1312 	return 0;
1313 }
1314 
1315 static int pscsi_CDB_none(struct se_task *task)
1316 {
1317 	return pscsi_blk_get_request(task);
1318 }
1319 
1320 /*	pscsi_get_cdb():
1321  *
1322  *
1323  */
1324 static unsigned char *pscsi_get_cdb(struct se_task *task)
1325 {
1326 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1327 
1328 	return pt->pscsi_cdb;
1329 }
1330 
1331 /*	pscsi_get_sense_buffer():
1332  *
1333  *
1334  */
1335 static unsigned char *pscsi_get_sense_buffer(struct se_task *task)
1336 {
1337 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1338 
1339 	return (unsigned char *)&pt->pscsi_sense[0];
1340 }
1341 
1342 /*	pscsi_get_device_rev():
1343  *
1344  *
1345  */
1346 static u32 pscsi_get_device_rev(struct se_device *dev)
1347 {
1348 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1349 	struct scsi_device *sd = pdv->pdv_sd;
1350 
1351 	return (sd->scsi_level - 1) ? sd->scsi_level - 1 : 1;
1352 }
1353 
1354 /*	pscsi_get_device_type():
1355  *
1356  *
1357  */
1358 static u32 pscsi_get_device_type(struct se_device *dev)
1359 {
1360 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1361 	struct scsi_device *sd = pdv->pdv_sd;
1362 
1363 	return sd->type;
1364 }
1365 
1366 static sector_t pscsi_get_blocks(struct se_device *dev)
1367 {
1368 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1369 
1370 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1371 		return pdv->pdv_bd->bd_part->nr_sects;
1372 
1373 	dump_stack();
1374 	return 0;
1375 }
1376 
1377 /*	pscsi_handle_SAM_STATUS_failures():
1378  *
1379  *
1380  */
1381 static inline void pscsi_process_SAM_status(
1382 	struct se_task *task,
1383 	struct pscsi_plugin_task *pt)
1384 {
1385 	task->task_scsi_status = status_byte(pt->pscsi_result);
1386 	if ((task->task_scsi_status)) {
1387 		task->task_scsi_status <<= 1;
1388 		printk(KERN_INFO "PSCSI Status Byte exception at task: %p CDB:"
1389 			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
1390 			pt->pscsi_result);
1391 	}
1392 
1393 	switch (host_byte(pt->pscsi_result)) {
1394 	case DID_OK:
1395 		transport_complete_task(task, (!task->task_scsi_status));
1396 		break;
1397 	default:
1398 		printk(KERN_INFO "PSCSI Host Byte exception at task: %p CDB:"
1399 			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
1400 			pt->pscsi_result);
1401 		task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
1402 		task->task_error_status = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
1403 		TASK_CMD(task)->transport_error_status =
1404 					PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
1405 		transport_complete_task(task, 0);
1406 		break;
1407 	}
1408 
1409 	return;
1410 }
1411 
1412 static void pscsi_req_done(struct request *req, int uptodate)
1413 {
1414 	struct se_task *task = req->end_io_data;
1415 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1416 
1417 	pt->pscsi_result = req->errors;
1418 	pt->pscsi_resid = req->resid_len;
1419 
1420 	pscsi_process_SAM_status(task, pt);
1421 	/*
1422 	 * Release BIDI-READ if present
1423 	 */
1424 	if (req->next_rq != NULL)
1425 		__blk_put_request(req->q, req->next_rq);
1426 
1427 	__blk_put_request(req->q, req);
1428 	pt->pscsi_req = NULL;
1429 }
1430 
1431 static struct se_subsystem_api pscsi_template = {
1432 	.name			= "pscsi",
1433 	.owner			= THIS_MODULE,
1434 	.transport_type		= TRANSPORT_PLUGIN_PHBA_PDEV,
1435 	.cdb_none		= pscsi_CDB_none,
1436 	.map_task_non_SG	= pscsi_map_task_non_SG,
1437 	.map_task_SG		= pscsi_map_task_SG,
1438 	.attach_hba		= pscsi_attach_hba,
1439 	.detach_hba		= pscsi_detach_hba,
1440 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1441 	.allocate_virtdevice	= pscsi_allocate_virtdevice,
1442 	.create_virtdevice	= pscsi_create_virtdevice,
1443 	.free_device		= pscsi_free_device,
1444 	.transport_complete	= pscsi_transport_complete,
1445 	.alloc_task		= pscsi_alloc_task,
1446 	.do_task		= pscsi_do_task,
1447 	.free_task		= pscsi_free_task,
1448 	.check_configfs_dev_params = pscsi_check_configfs_dev_params,
1449 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1450 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1451 	.get_cdb		= pscsi_get_cdb,
1452 	.get_sense_buffer	= pscsi_get_sense_buffer,
1453 	.get_device_rev		= pscsi_get_device_rev,
1454 	.get_device_type	= pscsi_get_device_type,
1455 	.get_blocks		= pscsi_get_blocks,
1456 };
1457 
1458 static int __init pscsi_module_init(void)
1459 {
1460 	return transport_subsystem_register(&pscsi_template);
1461 }
1462 
1463 static void pscsi_module_exit(void)
1464 {
1465 	transport_subsystem_release(&pscsi_template);
1466 }
1467 
1468 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1469 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1470 MODULE_LICENSE("GPL");
1471 
1472 module_init(pscsi_module_init);
1473 module_exit(pscsi_module_exit);
1474