xref: /openbmc/linux/drivers/target/target_core_pscsi.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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/smp_lock.h>
38 #include <linux/genhd.h>
39 #include <linux/cdrom.h>
40 #include <linux/file.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_device.h>
43 #include <scsi/scsi_cmnd.h>
44 #include <scsi/scsi_host.h>
45 #include <scsi/libsas.h> /* For TASK_ATTR_* */
46 
47 #include <target/target_core_base.h>
48 #include <target/target_core_device.h>
49 #include <target/target_core_transport.h>
50 
51 #include "target_core_pscsi.h"
52 
53 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
54 
55 static struct se_subsystem_api pscsi_template;
56 
57 static void pscsi_req_done(struct request *, int);
58 
59 /*	pscsi_get_sh():
60  *
61  *
62  */
63 static struct Scsi_Host *pscsi_get_sh(u32 host_no)
64 {
65 	struct Scsi_Host *sh = NULL;
66 
67 	sh = scsi_host_lookup(host_no);
68 	if (IS_ERR(sh)) {
69 		printk(KERN_ERR "Unable to locate SCSI HBA with Host ID:"
70 				" %u\n", host_no);
71 		return NULL;
72 	}
73 
74 	return sh;
75 }
76 
77 /*	pscsi_attach_hba():
78  *
79  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
80  *	from the passed SCSI Host ID.
81  */
82 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
83 {
84 	int hba_depth;
85 	struct pscsi_hba_virt *phv;
86 
87 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
88 	if (!(phv)) {
89 		printk(KERN_ERR "Unable to allocate struct pscsi_hba_virt\n");
90 		return -1;
91 	}
92 	phv->phv_host_id = host_id;
93 	phv->phv_mode = PHV_VIRUTAL_HOST_ID;
94 	hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
95 	atomic_set(&hba->left_queue_depth, hba_depth);
96 	atomic_set(&hba->max_queue_depth, hba_depth);
97 
98 	hba->hba_ptr = (void *)phv;
99 
100 	printk(KERN_INFO "CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
101 		" Generic Target Core Stack %s\n", hba->hba_id,
102 		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
103 	printk(KERN_INFO "CORE_HBA[%d] - Attached SCSI HBA to Generic"
104 		" Target Core with TCQ Depth: %d\n", hba->hba_id,
105 		atomic_read(&hba->max_queue_depth));
106 
107 	return 0;
108 }
109 
110 static void pscsi_detach_hba(struct se_hba *hba)
111 {
112 	struct pscsi_hba_virt *phv = hba->hba_ptr;
113 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
114 
115 	if (scsi_host) {
116 		scsi_host_put(scsi_host);
117 
118 		printk(KERN_INFO "CORE_HBA[%d] - Detached SCSI HBA: %s from"
119 			" Generic Target Core\n", hba->hba_id,
120 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
121 			"Unknown");
122 	} else
123 		printk(KERN_INFO "CORE_HBA[%d] - Detached Virtual SCSI HBA"
124 			" from Generic Target Core\n", hba->hba_id);
125 
126 	kfree(phv);
127 	hba->hba_ptr = NULL;
128 }
129 
130 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
131 {
132 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
133 	struct Scsi_Host *sh = phv->phv_lld_host;
134 	int hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
135 	/*
136 	 * Release the struct Scsi_Host
137 	 */
138 	if (!(mode_flag)) {
139 		if (!(sh))
140 			return 0;
141 
142 		phv->phv_lld_host = NULL;
143 		phv->phv_mode = PHV_VIRUTAL_HOST_ID;
144 		atomic_set(&hba->left_queue_depth, hba_depth);
145 		atomic_set(&hba->max_queue_depth, hba_depth);
146 
147 		printk(KERN_INFO "CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
148 			" %s\n", hba->hba_id, (sh->hostt->name) ?
149 			(sh->hostt->name) : "Unknown");
150 
151 		scsi_host_put(sh);
152 		return 0;
153 	}
154 	/*
155 	 * Otherwise, locate struct Scsi_Host from the original passed
156 	 * pSCSI Host ID and enable for phba mode
157 	 */
158 	sh = pscsi_get_sh(phv->phv_host_id);
159 	if (!(sh)) {
160 		printk(KERN_ERR "pSCSI: Unable to locate SCSI Host for"
161 			" phv_host_id: %d\n", phv->phv_host_id);
162 		return -1;
163 	}
164 	/*
165 	 * Usually the SCSI LLD will use the hostt->can_queue value to define
166 	 * its HBA TCQ depth.  Some other drivers (like 2.6 megaraid) don't set
167 	 * this at all and set sh->can_queue at runtime.
168 	 */
169 	hba_depth = (sh->hostt->can_queue > sh->can_queue) ?
170 		sh->hostt->can_queue : sh->can_queue;
171 
172 	atomic_set(&hba->left_queue_depth, hba_depth);
173 	atomic_set(&hba->max_queue_depth, hba_depth);
174 
175 	phv->phv_lld_host = sh;
176 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
177 
178 	printk(KERN_INFO "CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
179 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
180 
181 	return 1;
182 }
183 
184 static void pscsi_tape_read_blocksize(struct se_device *dev,
185 		struct scsi_device *sdev)
186 {
187 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
188 	int ret;
189 
190 	buf = kzalloc(12, GFP_KERNEL);
191 	if (!buf)
192 		return;
193 
194 	memset(cdb, 0, MAX_COMMAND_SIZE);
195 	cdb[0] = MODE_SENSE;
196 	cdb[4] = 0x0c; /* 12 bytes */
197 
198 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
199 			HZ, 1, NULL);
200 	if (ret)
201 		goto out_free;
202 
203 	/*
204 	 * If MODE_SENSE still returns zero, set the default value to 1024.
205 	 */
206 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
207 	if (!sdev->sector_size)
208 		sdev->sector_size = 1024;
209 out_free:
210 	kfree(buf);
211 }
212 
213 static void
214 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
215 {
216 	unsigned char *buf;
217 
218 	if (sdev->inquiry_len < INQUIRY_LEN)
219 		return;
220 
221 	buf = sdev->inquiry;
222 	if (!buf)
223 		return;
224 	/*
225 	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
226 	 */
227 	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
228 	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
229 	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
230 }
231 
232 static int
233 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
234 {
235 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
236 	int ret;
237 
238 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
239 	if (!buf)
240 		return -1;
241 
242 	memset(cdb, 0, MAX_COMMAND_SIZE);
243 	cdb[0] = INQUIRY;
244 	cdb[1] = 0x01; /* Query VPD */
245 	cdb[2] = 0x80; /* Unit Serial Number */
246 	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
247 	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
248 
249 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
250 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
251 	if (ret)
252 		goto out_free;
253 
254 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
255 
256 	wwn->t10_sub_dev->su_dev_flags |= SDF_FIRMWARE_VPD_UNIT_SERIAL;
257 
258 	kfree(buf);
259 	return 0;
260 
261 out_free:
262 	kfree(buf);
263 	return -1;
264 }
265 
266 static void
267 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
268 		struct t10_wwn *wwn)
269 {
270 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
271 	int ident_len, page_len, off = 4, ret;
272 	struct t10_vpd *vpd;
273 
274 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
275 	if (!buf)
276 		return;
277 
278 	memset(cdb, 0, MAX_COMMAND_SIZE);
279 	cdb[0] = INQUIRY;
280 	cdb[1] = 0x01; /* Query VPD */
281 	cdb[2] = 0x83; /* Device Identifier */
282 	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
283 	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
284 
285 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
286 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
287 			      NULL, HZ, 1, NULL);
288 	if (ret)
289 		goto out;
290 
291 	page_len = (buf[2] << 8) | buf[3];
292 	while (page_len > 0) {
293 		/* Grab a pointer to the Identification descriptor */
294 		page_83 = &buf[off];
295 		ident_len = page_83[3];
296 		if (!ident_len) {
297 			printk(KERN_ERR "page_83[3]: identifier"
298 					" length zero!\n");
299 			break;
300 		}
301 		printk(KERN_INFO "T10 VPD Identifer Length: %d\n", ident_len);
302 
303 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
304 		if (!vpd) {
305 			printk(KERN_ERR "Unable to allocate memory for"
306 					" struct t10_vpd\n");
307 			goto out;
308 		}
309 		INIT_LIST_HEAD(&vpd->vpd_list);
310 
311 		transport_set_vpd_proto_id(vpd, page_83);
312 		transport_set_vpd_assoc(vpd, page_83);
313 
314 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
315 			off += (ident_len + 4);
316 			page_len -= (ident_len + 4);
317 			kfree(vpd);
318 			continue;
319 		}
320 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
321 			off += (ident_len + 4);
322 			page_len -= (ident_len + 4);
323 			kfree(vpd);
324 			continue;
325 		}
326 
327 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
328 		off += (ident_len + 4);
329 		page_len -= (ident_len + 4);
330 	}
331 
332 out:
333 	kfree(buf);
334 }
335 
336 /*	pscsi_add_device_to_list():
337  *
338  *
339  */
340 static struct se_device *pscsi_add_device_to_list(
341 	struct se_hba *hba,
342 	struct se_subsystem_dev *se_dev,
343 	struct pscsi_dev_virt *pdv,
344 	struct scsi_device *sd,
345 	int dev_flags)
346 {
347 	struct se_device *dev;
348 	struct se_dev_limits dev_limits;
349 	struct request_queue *q;
350 	struct queue_limits *limits;
351 
352 	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
353 
354 	if (!sd->queue_depth) {
355 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
356 
357 		printk(KERN_ERR "Set broken SCSI Device %d:%d:%d"
358 			" queue_depth to %d\n", sd->channel, sd->id,
359 				sd->lun, sd->queue_depth);
360 	}
361 	/*
362 	 * Setup the local scope queue_limits from struct request_queue->limits
363 	 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
364 	 */
365 	q = sd->request_queue;
366 	limits = &dev_limits.limits;
367 	limits->logical_block_size = sd->sector_size;
368 	limits->max_hw_sectors = (sd->host->max_sectors > queue_max_hw_sectors(q)) ?
369 				  queue_max_hw_sectors(q) : sd->host->max_sectors;
370 	limits->max_sectors = (sd->host->max_sectors > queue_max_sectors(q)) ?
371 				  queue_max_sectors(q) : sd->host->max_sectors;
372 	dev_limits.hw_queue_depth = sd->queue_depth;
373 	dev_limits.queue_depth = sd->queue_depth;
374 	/*
375 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
376 	 */
377 	pscsi_set_inquiry_info(sd, &se_dev->t10_wwn);
378 
379 	/*
380 	 * Set the pointer pdv->pdv_sd to from passed struct scsi_device,
381 	 * which has already been referenced with Linux SCSI code with
382 	 * scsi_device_get() in this file's pscsi_create_virtdevice().
383 	 *
384 	 * The passthrough operations called by the transport_add_device_*
385 	 * function below will require this pointer to be set for passthroug
386 	 *  ops.
387 	 *
388 	 * For the shutdown case in pscsi_free_device(), this struct
389 	 * scsi_device  reference is released with Linux SCSI code
390 	 * scsi_device_put() and the pdv->pdv_sd cleared.
391 	 */
392 	pdv->pdv_sd = sd;
393 
394 	dev = transport_add_device_to_core_hba(hba, &pscsi_template,
395 				se_dev, dev_flags, (void *)pdv,
396 				&dev_limits, NULL, NULL);
397 	if (!(dev)) {
398 		pdv->pdv_sd = NULL;
399 		return NULL;
400 	}
401 
402 	/*
403 	 * Locate VPD WWN Information used for various purposes within
404 	 * the Storage Engine.
405 	 */
406 	if (!pscsi_get_inquiry_vpd_serial(sd, &se_dev->t10_wwn)) {
407 		/*
408 		 * If VPD Unit Serial returned GOOD status, try
409 		 * VPD Device Identification page (0x83).
410 		 */
411 		pscsi_get_inquiry_vpd_device_ident(sd, &se_dev->t10_wwn);
412 	}
413 
414 	/*
415 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
416 	 */
417 	if (sd->type == TYPE_TAPE)
418 		pscsi_tape_read_blocksize(dev, sd);
419 	return dev;
420 }
421 
422 static void *pscsi_allocate_virtdevice(struct se_hba *hba, const char *name)
423 {
424 	struct pscsi_dev_virt *pdv;
425 
426 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
427 	if (!(pdv)) {
428 		printk(KERN_ERR "Unable to allocate memory for struct pscsi_dev_virt\n");
429 		return NULL;
430 	}
431 	pdv->pdv_se_hba = hba;
432 
433 	printk(KERN_INFO "PSCSI: Allocated pdv: %p for %s\n", pdv, name);
434 	return (void *)pdv;
435 }
436 
437 /*
438  * Called with struct Scsi_Host->host_lock called.
439  */
440 static struct se_device *pscsi_create_type_disk(
441 	struct scsi_device *sd,
442 	struct pscsi_dev_virt *pdv,
443 	struct se_subsystem_dev *se_dev,
444 	struct se_hba *hba)
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 {
493 	struct se_device *dev;
494 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
495 	struct Scsi_Host *sh = sd->host;
496 	u32 dev_flags = 0;
497 
498 	if (scsi_device_get(sd)) {
499 		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
500 			sh->host_no, sd->channel, sd->id, sd->lun);
501 		spin_unlock_irq(sh->host_lock);
502 		return NULL;
503 	}
504 	spin_unlock_irq(sh->host_lock);
505 
506 	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
507 	if (!(dev)) {
508 		scsi_device_put(sd);
509 		return NULL;
510 	}
511 	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
512 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
513 		sd->channel, sd->id, sd->lun);
514 
515 	return dev;
516 }
517 
518 /*
519  *Called with struct Scsi_Host->host_lock called.
520  */
521 static struct se_device *pscsi_create_type_other(
522 	struct scsi_device *sd,
523 	struct pscsi_dev_virt *pdv,
524 	struct se_subsystem_dev *se_dev,
525 	struct se_hba *hba)
526 {
527 	struct se_device *dev;
528 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
529 	struct Scsi_Host *sh = sd->host;
530 	u32 dev_flags = 0;
531 
532 	spin_unlock_irq(sh->host_lock);
533 	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
534 	if (!(dev))
535 		return NULL;
536 
537 	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
538 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
539 		sd->channel, sd->id, sd->lun);
540 
541 	return dev;
542 }
543 
544 static struct se_device *pscsi_create_virtdevice(
545 	struct se_hba *hba,
546 	struct se_subsystem_dev *se_dev,
547 	void *p)
548 {
549 	struct pscsi_dev_virt *pdv = (struct pscsi_dev_virt *)p;
550 	struct se_device *dev;
551 	struct scsi_device *sd;
552 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
553 	struct Scsi_Host *sh = phv->phv_lld_host;
554 	int legacy_mode_enable = 0;
555 
556 	if (!(pdv)) {
557 		printk(KERN_ERR "Unable to locate struct pscsi_dev_virt"
558 				" parameter\n");
559 		return NULL;
560 	}
561 	/*
562 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
563 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
564 	 */
565 	if (!(sh)) {
566 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
567 			printk(KERN_ERR "pSCSI: Unable to locate struct"
568 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
569 			return NULL;
570 		}
571 		/*
572 		 * For the newer PHV_VIRUTAL_HOST_ID struct scsi_device
573 		 * reference, we enforce that udev_path has been set
574 		 */
575 		if (!(se_dev->su_dev_flags & SDF_USING_UDEV_PATH)) {
576 			printk(KERN_ERR "pSCSI: udev_path attribute has not"
577 				" been set before ENABLE=1\n");
578 			return NULL;
579 		}
580 		/*
581 		 * If no scsi_host_id= was passed for PHV_VIRUTAL_HOST_ID,
582 		 * use the original TCM hba ID to reference Linux/SCSI Host No
583 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
584 		 */
585 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
586 			spin_lock(&hba->device_lock);
587 			if (!(list_empty(&hba->hba_dev_list))) {
588 				printk(KERN_ERR "pSCSI: Unable to set hba_mode"
589 					" with active devices\n");
590 				spin_unlock(&hba->device_lock);
591 				return NULL;
592 			}
593 			spin_unlock(&hba->device_lock);
594 
595 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
596 				return NULL;
597 
598 			legacy_mode_enable = 1;
599 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
600 			sh = phv->phv_lld_host;
601 		} else {
602 			sh = pscsi_get_sh(pdv->pdv_host_id);
603 			if (!(sh)) {
604 				printk(KERN_ERR "pSCSI: Unable to locate"
605 					" pdv_host_id: %d\n", pdv->pdv_host_id);
606 				return NULL;
607 			}
608 		}
609 	} else {
610 		if (phv->phv_mode == PHV_VIRUTAL_HOST_ID) {
611 			printk(KERN_ERR "pSCSI: PHV_VIRUTAL_HOST_ID set while"
612 				" struct Scsi_Host exists\n");
613 			return NULL;
614 		}
615 	}
616 
617 	spin_lock_irq(sh->host_lock);
618 	list_for_each_entry(sd, &sh->__devices, siblings) {
619 		if ((pdv->pdv_channel_id != sd->channel) ||
620 		    (pdv->pdv_target_id != sd->id) ||
621 		    (pdv->pdv_lun_id != sd->lun))
622 			continue;
623 		/*
624 		 * Functions will release the held struct scsi_host->host_lock
625 		 * before calling calling pscsi_add_device_to_list() to register
626 		 * struct scsi_device with target_core_mod.
627 		 */
628 		switch (sd->type) {
629 		case TYPE_DISK:
630 			dev = pscsi_create_type_disk(sd, pdv, se_dev, hba);
631 			break;
632 		case TYPE_ROM:
633 			dev = pscsi_create_type_rom(sd, pdv, se_dev, hba);
634 			break;
635 		default:
636 			dev = pscsi_create_type_other(sd, pdv, se_dev, hba);
637 			break;
638 		}
639 
640 		if (!(dev)) {
641 			if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
642 				scsi_host_put(sh);
643 			else if (legacy_mode_enable) {
644 				pscsi_pmode_enable_hba(hba, 0);
645 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
646 			}
647 			pdv->pdv_sd = NULL;
648 			return NULL;
649 		}
650 		return dev;
651 	}
652 	spin_unlock_irq(sh->host_lock);
653 
654 	printk(KERN_ERR "pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
655 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
656 
657 	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
658 		scsi_host_put(sh);
659 	else if (legacy_mode_enable) {
660 		pscsi_pmode_enable_hba(hba, 0);
661 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
662 	}
663 
664 	return NULL;
665 }
666 
667 /*	pscsi_free_device(): (Part of se_subsystem_api_t template)
668  *
669  *
670  */
671 static void pscsi_free_device(void *p)
672 {
673 	struct pscsi_dev_virt *pdv = p;
674 	struct pscsi_hba_virt *phv = pdv->pdv_se_hba->hba_ptr;
675 	struct scsi_device *sd = pdv->pdv_sd;
676 
677 	if (sd) {
678 		/*
679 		 * Release exclusive pSCSI internal struct block_device claim for
680 		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
681 		 */
682 		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
683 			blkdev_put(pdv->pdv_bd,
684 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
685 			pdv->pdv_bd = NULL;
686 		}
687 		/*
688 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
689 		 * to struct Scsi_Host now.
690 		 */
691 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
692 		    (phv->phv_lld_host != NULL))
693 			scsi_host_put(phv->phv_lld_host);
694 
695 		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
696 			scsi_device_put(sd);
697 
698 		pdv->pdv_sd = NULL;
699 	}
700 
701 	kfree(pdv);
702 }
703 
704 static inline struct pscsi_plugin_task *PSCSI_TASK(struct se_task *task)
705 {
706 	return container_of(task, struct pscsi_plugin_task, pscsi_task);
707 }
708 
709 
710 /*	pscsi_transport_complete():
711  *
712  *
713  */
714 static int pscsi_transport_complete(struct se_task *task)
715 {
716 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
717 	struct scsi_device *sd = pdv->pdv_sd;
718 	int result;
719 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
720 	unsigned char *cdb = &pt->pscsi_cdb[0];
721 
722 	result = pt->pscsi_result;
723 	/*
724 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
725 	 * forced.
726 	 */
727 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
728 	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
729 		if (!TASK_CMD(task)->se_deve)
730 			goto after_mode_sense;
731 
732 		if (TASK_CMD(task)->se_deve->lun_flags &
733 				TRANSPORT_LUNFLAGS_READ_ONLY) {
734 			unsigned char *buf = (unsigned char *)
735 				T_TASK(task->task_se_cmd)->t_task_buf;
736 
737 			if (cdb[0] == MODE_SENSE_10) {
738 				if (!(buf[3] & 0x80))
739 					buf[3] |= 0x80;
740 			} else {
741 				if (!(buf[2] & 0x80))
742 					buf[2] |= 0x80;
743 			}
744 		}
745 	}
746 after_mode_sense:
747 
748 	if (sd->type != TYPE_TAPE)
749 		goto after_mode_select;
750 
751 	/*
752 	 * Hack to correctly obtain the initiator requested blocksize for
753 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
754 	 * struct scsi_device->sector_size will not contain the correct value
755 	 * by default, so we go ahead and set it so
756 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
757 	 * storage engine.
758 	 */
759 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
760 	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
761 		unsigned char *buf;
762 		struct scatterlist *sg = task->task_sg;
763 		u16 bdl;
764 		u32 blocksize;
765 
766 		buf = sg_virt(&sg[0]);
767 		if (!(buf)) {
768 			printk(KERN_ERR "Unable to get buf for scatterlist\n");
769 			goto after_mode_select;
770 		}
771 
772 		if (cdb[0] == MODE_SELECT)
773 			bdl = (buf[3]);
774 		else
775 			bdl = (buf[6] << 8) | (buf[7]);
776 
777 		if (!bdl)
778 			goto after_mode_select;
779 
780 		if (cdb[0] == MODE_SELECT)
781 			blocksize = (buf[9] << 16) | (buf[10] << 8) |
782 					(buf[11]);
783 		else
784 			blocksize = (buf[13] << 16) | (buf[14] << 8) |
785 					(buf[15]);
786 
787 		sd->sector_size = blocksize;
788 	}
789 after_mode_select:
790 
791 	if (status_byte(result) & CHECK_CONDITION)
792 		return 1;
793 
794 	return 0;
795 }
796 
797 static struct se_task *
798 pscsi_alloc_task(struct se_cmd *cmd)
799 {
800 	struct pscsi_plugin_task *pt;
801 	unsigned char *cdb = T_TASK(cmd)->t_task_cdb;
802 
803 	pt = kzalloc(sizeof(struct pscsi_plugin_task), GFP_KERNEL);
804 	if (!pt) {
805 		printk(KERN_ERR "Unable to allocate struct pscsi_plugin_task\n");
806 		return NULL;
807 	}
808 
809 	/*
810 	 * If TCM Core is signaling a > TCM_MAX_COMMAND_SIZE allocation,
811 	 * allocate the extended CDB buffer for per struct se_task context
812 	 * pt->pscsi_cdb now.
813 	 */
814 	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb) {
815 
816 		pt->pscsi_cdb = kzalloc(scsi_command_size(cdb), GFP_KERNEL);
817 		if (!(pt->pscsi_cdb)) {
818 			printk(KERN_ERR "pSCSI: Unable to allocate extended"
819 					" pt->pscsi_cdb\n");
820 			return NULL;
821 		}
822 	} else
823 		pt->pscsi_cdb = &pt->__pscsi_cdb[0];
824 
825 	return &pt->pscsi_task;
826 }
827 
828 static inline void pscsi_blk_init_request(
829 	struct se_task *task,
830 	struct pscsi_plugin_task *pt,
831 	struct request *req,
832 	int bidi_read)
833 {
834 	/*
835 	 * Defined as "scsi command" in include/linux/blkdev.h.
836 	 */
837 	req->cmd_type = REQ_TYPE_BLOCK_PC;
838 	/*
839 	 * For the extra BIDI-COMMAND READ struct request we do not
840 	 * need to setup the remaining structure members
841 	 */
842 	if (bidi_read)
843 		return;
844 	/*
845 	 * Setup the done function pointer for struct request,
846 	 * also set the end_io_data pointer.to struct se_task.
847 	 */
848 	req->end_io = pscsi_req_done;
849 	req->end_io_data = (void *)task;
850 	/*
851 	 * Load the referenced struct se_task's SCSI CDB into
852 	 * include/linux/blkdev.h:struct request->cmd
853 	 */
854 	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
855 	req->cmd = &pt->pscsi_cdb[0];
856 	/*
857 	 * Setup pointer for outgoing sense data.
858 	 */
859 	req->sense = (void *)&pt->pscsi_sense[0];
860 	req->sense_len = 0;
861 }
862 
863 /*
864  * Used for pSCSI data payloads for all *NON* SCF_SCSI_DATA_SG_IO_CDB
865 */
866 static int pscsi_blk_get_request(struct se_task *task)
867 {
868 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
869 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
870 
871 	pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
872 			(task->task_data_direction == DMA_TO_DEVICE),
873 			GFP_KERNEL);
874 	if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
875 		printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
876 				IS_ERR(pt->pscsi_req));
877 		return PYX_TRANSPORT_LU_COMM_FAILURE;
878 	}
879 	/*
880 	 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
881 	 * and setup rq callback, CDB and sense.
882 	 */
883 	pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
884 	return 0;
885 }
886 
887 /*      pscsi_do_task(): (Part of se_subsystem_api_t template)
888  *
889  *
890  */
891 static int pscsi_do_task(struct se_task *task)
892 {
893 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
894 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
895 	/*
896 	 * Set the struct request->timeout value based on peripheral
897 	 * device type from SCSI.
898 	 */
899 	if (pdv->pdv_sd->type == TYPE_DISK)
900 		pt->pscsi_req->timeout = PS_TIMEOUT_DISK;
901 	else
902 		pt->pscsi_req->timeout = PS_TIMEOUT_OTHER;
903 
904 	pt->pscsi_req->retries = PS_RETRY;
905 	/*
906 	 * Queue the struct request into the struct scsi_device->request_queue.
907 	 * Also check for HEAD_OF_QUEUE SAM TASK attr from received se_cmd
908 	 * descriptor
909 	 */
910 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, pt->pscsi_req,
911 			(task->task_se_cmd->sam_task_attr == TASK_ATTR_HOQ),
912 			pscsi_req_done);
913 
914 	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
915 }
916 
917 static void pscsi_free_task(struct se_task *task)
918 {
919 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
920 	struct se_cmd *cmd = task->task_se_cmd;
921 
922 	/*
923 	 * Release the extended CDB allocation from pscsi_alloc_task()
924 	 * if one exists.
925 	 */
926 	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb)
927 		kfree(pt->pscsi_cdb);
928 	/*
929 	 * We do not release the bio(s) here associated with this task, as
930 	 * this is handled by bio_put() and pscsi_bi_endio().
931 	 */
932 	kfree(pt);
933 }
934 
935 enum {
936 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
937 	Opt_scsi_lun_id, Opt_err
938 };
939 
940 static match_table_t tokens = {
941 	{Opt_scsi_host_id, "scsi_host_id=%d"},
942 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
943 	{Opt_scsi_target_id, "scsi_target_id=%d"},
944 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
945 	{Opt_err, NULL}
946 };
947 
948 static ssize_t pscsi_set_configfs_dev_params(struct se_hba *hba,
949 	struct se_subsystem_dev *se_dev,
950 	const char *page,
951 	ssize_t count)
952 {
953 	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
954 	struct pscsi_hba_virt *phv = hba->hba_ptr;
955 	char *orig, *ptr, *opts;
956 	substring_t args[MAX_OPT_ARGS];
957 	int ret = 0, arg, token;
958 
959 	opts = kstrdup(page, GFP_KERNEL);
960 	if (!opts)
961 		return -ENOMEM;
962 
963 	orig = opts;
964 
965 	while ((ptr = strsep(&opts, ",")) != NULL) {
966 		if (!*ptr)
967 			continue;
968 
969 		token = match_token(ptr, tokens, args);
970 		switch (token) {
971 		case Opt_scsi_host_id:
972 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
973 				printk(KERN_ERR "PSCSI[%d]: Unable to accept"
974 					" scsi_host_id while phv_mode =="
975 					" PHV_LLD_SCSI_HOST_NO\n",
976 					phv->phv_host_id);
977 				ret = -EINVAL;
978 				goto out;
979 			}
980 			match_int(args, &arg);
981 			pdv->pdv_host_id = arg;
982 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Host ID:"
983 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
984 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
985 			break;
986 		case Opt_scsi_channel_id:
987 			match_int(args, &arg);
988 			pdv->pdv_channel_id = arg;
989 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Channel"
990 				" ID: %d\n",  phv->phv_host_id,
991 				pdv->pdv_channel_id);
992 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
993 			break;
994 		case Opt_scsi_target_id:
995 			match_int(args, &arg);
996 			pdv->pdv_target_id = arg;
997 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Target"
998 				" ID: %d\n", phv->phv_host_id,
999 				pdv->pdv_target_id);
1000 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
1001 			break;
1002 		case Opt_scsi_lun_id:
1003 			match_int(args, &arg);
1004 			pdv->pdv_lun_id = arg;
1005 			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI LUN ID:"
1006 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
1007 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
1008 			break;
1009 		default:
1010 			break;
1011 		}
1012 	}
1013 
1014 out:
1015 	kfree(orig);
1016 	return (!ret) ? count : ret;
1017 }
1018 
1019 static ssize_t pscsi_check_configfs_dev_params(
1020 	struct se_hba *hba,
1021 	struct se_subsystem_dev *se_dev)
1022 {
1023 	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
1024 
1025 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
1026 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
1027 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
1028 		printk(KERN_ERR "Missing scsi_channel_id=, scsi_target_id= and"
1029 			" scsi_lun_id= parameters\n");
1030 		return -1;
1031 	}
1032 
1033 	return 0;
1034 }
1035 
1036 static ssize_t pscsi_show_configfs_dev_params(struct se_hba *hba,
1037 					      struct se_subsystem_dev *se_dev,
1038 					      char *b)
1039 {
1040 	struct pscsi_hba_virt *phv = hba->hba_ptr;
1041         struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
1042 	struct scsi_device *sd = pdv->pdv_sd;
1043 	unsigned char host_id[16];
1044 	ssize_t bl;
1045 	int i;
1046 
1047 	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
1048 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
1049 	else
1050 		snprintf(host_id, 16, "PHBA Mode");
1051 
1052 	bl = sprintf(b, "SCSI Device Bus Location:"
1053 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
1054 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
1055 		host_id);
1056 
1057 	if (sd) {
1058 		bl += sprintf(b + bl, "        ");
1059 		bl += sprintf(b + bl, "Vendor: ");
1060 		for (i = 0; i < 8; i++) {
1061 			if (ISPRINT(sd->vendor[i]))   /* printable character? */
1062 				bl += sprintf(b + bl, "%c", sd->vendor[i]);
1063 			else
1064 				bl += sprintf(b + bl, " ");
1065 		}
1066 		bl += sprintf(b + bl, " Model: ");
1067 		for (i = 0; i < 16; i++) {
1068 			if (ISPRINT(sd->model[i]))   /* printable character ? */
1069 				bl += sprintf(b + bl, "%c", sd->model[i]);
1070 			else
1071 				bl += sprintf(b + bl, " ");
1072 		}
1073 		bl += sprintf(b + bl, " Rev: ");
1074 		for (i = 0; i < 4; i++) {
1075 			if (ISPRINT(sd->rev[i]))   /* printable character ? */
1076 				bl += sprintf(b + bl, "%c", sd->rev[i]);
1077 			else
1078 				bl += sprintf(b + bl, " ");
1079 		}
1080 		bl += sprintf(b + bl, "\n");
1081 	}
1082 	return bl;
1083 }
1084 
1085 static void pscsi_bi_endio(struct bio *bio, int error)
1086 {
1087 	bio_put(bio);
1088 }
1089 
1090 static inline struct bio *pscsi_get_bio(struct pscsi_dev_virt *pdv, int sg_num)
1091 {
1092 	struct bio *bio;
1093 	/*
1094 	 * Use bio_malloc() following the comment in for bio -> struct request
1095 	 * in block/blk-core.c:blk_make_request()
1096 	 */
1097 	bio = bio_kmalloc(GFP_KERNEL, sg_num);
1098 	if (!(bio)) {
1099 		printk(KERN_ERR "PSCSI: bio_kmalloc() failed\n");
1100 		return NULL;
1101 	}
1102 	bio->bi_end_io = pscsi_bi_endio;
1103 
1104 	return bio;
1105 }
1106 
1107 #if 0
1108 #define DEBUG_PSCSI(x...) printk(x)
1109 #else
1110 #define DEBUG_PSCSI(x...)
1111 #endif
1112 
1113 static int __pscsi_map_task_SG(
1114 	struct se_task *task,
1115 	struct scatterlist *task_sg,
1116 	u32 task_sg_num,
1117 	int bidi_read)
1118 {
1119 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1120 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
1121 	struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
1122 	struct page *page;
1123 	struct scatterlist *sg;
1124 	u32 data_len = task->task_size, i, len, bytes, off;
1125 	int nr_pages = (task->task_size + task_sg[0].offset +
1126 			PAGE_SIZE - 1) >> PAGE_SHIFT;
1127 	int nr_vecs = 0, rc, ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
1128 	int rw = (task->task_data_direction == DMA_TO_DEVICE);
1129 
1130 	if (!task->task_size)
1131 		return 0;
1132 	/*
1133 	 * For SCF_SCSI_DATA_SG_IO_CDB, Use fs/bio.c:bio_add_page() to setup
1134 	 * the bio_vec maplist from TC< struct se_mem -> task->task_sg ->
1135 	 * struct scatterlist memory.  The struct se_task->task_sg[] currently needs
1136 	 * to be attached to struct bios for submission to Linux/SCSI using
1137 	 * struct request to struct scsi_device->request_queue.
1138 	 *
1139 	 * Note that this will be changing post v2.6.28 as Target_Core_Mod/pSCSI
1140 	 * is ported to upstream SCSI passthrough functionality that accepts
1141 	 * struct scatterlist->page_link or struct page as a paraemeter.
1142 	 */
1143 	DEBUG_PSCSI("PSCSI: nr_pages: %d\n", nr_pages);
1144 
1145 	for_each_sg(task_sg, sg, task_sg_num, i) {
1146 		page = sg_page(sg);
1147 		off = sg->offset;
1148 		len = sg->length;
1149 
1150 		DEBUG_PSCSI("PSCSI: i: %d page: %p len: %d off: %d\n", i,
1151 			page, len, off);
1152 
1153 		while (len > 0 && data_len > 0) {
1154 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
1155 			bytes = min(bytes, data_len);
1156 
1157 			if (!(bio)) {
1158 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
1159 				nr_pages -= nr_vecs;
1160 				/*
1161 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
1162 				 */
1163 				bio = pscsi_get_bio(pdv, nr_vecs);
1164 				if (!(bio))
1165 					goto fail;
1166 
1167 				if (rw)
1168 					bio->bi_rw |= REQ_WRITE;
1169 
1170 				DEBUG_PSCSI("PSCSI: Allocated bio: %p,"
1171 					" dir: %s nr_vecs: %d\n", bio,
1172 					(rw) ? "rw" : "r", nr_vecs);
1173 				/*
1174 				 * Set *hbio pointer to handle the case:
1175 				 * nr_pages > BIO_MAX_PAGES, where additional
1176 				 * bios need to be added to complete a given
1177 				 * struct se_task
1178 				 */
1179 				if (!hbio)
1180 					hbio = tbio = bio;
1181 				else
1182 					tbio = tbio->bi_next = bio;
1183 			}
1184 
1185 			DEBUG_PSCSI("PSCSI: Calling bio_add_pc_page() i: %d"
1186 				" bio: %p page: %p len: %d off: %d\n", i, bio,
1187 				page, len, off);
1188 
1189 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
1190 					bio, page, bytes, off);
1191 			if (rc != bytes)
1192 				goto fail;
1193 
1194 			DEBUG_PSCSI("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
1195 				bio->bi_vcnt, nr_vecs);
1196 
1197 			if (bio->bi_vcnt > nr_vecs) {
1198 				DEBUG_PSCSI("PSCSI: Reached bio->bi_vcnt max:"
1199 					" %d i: %d bio: %p, allocating another"
1200 					" bio\n", bio->bi_vcnt, i, bio);
1201 				/*
1202 				 * Clear the pointer so that another bio will
1203 				 * be allocated with pscsi_get_bio() above, the
1204 				 * current bio has already been set *tbio and
1205 				 * bio->bi_next.
1206 				 */
1207 				bio = NULL;
1208 			}
1209 
1210 			page++;
1211 			len -= bytes;
1212 			data_len -= bytes;
1213 			off = 0;
1214 		}
1215 	}
1216 	/*
1217 	 * Setup the primary pt->pscsi_req used for non BIDI and BIDI-COMMAND
1218 	 * primary SCSI WRITE poayload mapped for struct se_task->task_sg[]
1219 	 */
1220 	if (!(bidi_read)) {
1221 		/*
1222 		 * Starting with v2.6.31, call blk_make_request() passing in *hbio to
1223 		 * allocate the pSCSI task a struct request.
1224 		 */
1225 		pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
1226 					hbio, GFP_KERNEL);
1227 		if (!(pt->pscsi_req)) {
1228 			printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
1229 			goto fail;
1230 		}
1231 		/*
1232 		 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
1233 		 * and setup rq callback, CDB and sense.
1234 		 */
1235 		pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
1236 
1237 		return task->task_sg_num;
1238 	}
1239 	/*
1240 	 * Setup the secondary pt->pscsi_req->next_rq used for the extra BIDI-COMMAND
1241 	 * SCSI READ paylaod mapped for struct se_task->task_sg_bidi[]
1242 	 */
1243 	pt->pscsi_req->next_rq = blk_make_request(pdv->pdv_sd->request_queue,
1244 					hbio, GFP_KERNEL);
1245 	if (!(pt->pscsi_req->next_rq)) {
1246 		printk(KERN_ERR "pSCSI: blk_make_request() failed for BIDI\n");
1247 		goto fail;
1248 	}
1249 	pscsi_blk_init_request(task, pt, pt->pscsi_req->next_rq, 1);
1250 
1251 	return task->task_sg_num;
1252 fail:
1253 	while (hbio) {
1254 		bio = hbio;
1255 		hbio = hbio->bi_next;
1256 		bio->bi_next = NULL;
1257 		bio_endio(bio, 0);
1258 	}
1259 	return ret;
1260 }
1261 
1262 static int pscsi_map_task_SG(struct se_task *task)
1263 {
1264 	int ret;
1265 
1266 	/*
1267 	 * Setup the main struct request for the task->task_sg[] payload
1268 	 */
1269 
1270 	ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_num, 0);
1271 	if (ret >= 0 && task->task_sg_bidi) {
1272 		/*
1273 		 * If present, set up the extra BIDI-COMMAND SCSI READ
1274 		 * struct request and payload.
1275 		 */
1276 		ret = __pscsi_map_task_SG(task, task->task_sg_bidi,
1277 					task->task_sg_num, 1);
1278 	}
1279 
1280 	if (ret < 0)
1281 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1282 	return 0;
1283 }
1284 
1285 /*	pscsi_map_task_non_SG():
1286  *
1287  *
1288  */
1289 static int pscsi_map_task_non_SG(struct se_task *task)
1290 {
1291 	struct se_cmd *cmd = TASK_CMD(task);
1292 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1293 	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
1294 	int ret = 0;
1295 
1296 	if (pscsi_blk_get_request(task) < 0)
1297 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1298 
1299 	if (!task->task_size)
1300 		return 0;
1301 
1302 	ret = blk_rq_map_kern(pdv->pdv_sd->request_queue,
1303 			pt->pscsi_req, T_TASK(cmd)->t_task_buf,
1304 			task->task_size, GFP_KERNEL);
1305 	if (ret < 0) {
1306 		printk(KERN_ERR "PSCSI: blk_rq_map_kern() failed: %d\n", ret);
1307 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1308 	}
1309 	return 0;
1310 }
1311 
1312 static int pscsi_CDB_none(struct se_task *task)
1313 {
1314 	return pscsi_blk_get_request(task);
1315 }
1316 
1317 /*	pscsi_get_cdb():
1318  *
1319  *
1320  */
1321 static unsigned char *pscsi_get_cdb(struct se_task *task)
1322 {
1323 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1324 
1325 	return pt->pscsi_cdb;
1326 }
1327 
1328 /*	pscsi_get_sense_buffer():
1329  *
1330  *
1331  */
1332 static unsigned char *pscsi_get_sense_buffer(struct se_task *task)
1333 {
1334 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1335 
1336 	return (unsigned char *)&pt->pscsi_sense[0];
1337 }
1338 
1339 /*	pscsi_get_device_rev():
1340  *
1341  *
1342  */
1343 static u32 pscsi_get_device_rev(struct se_device *dev)
1344 {
1345 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1346 	struct scsi_device *sd = pdv->pdv_sd;
1347 
1348 	return (sd->scsi_level - 1) ? sd->scsi_level - 1 : 1;
1349 }
1350 
1351 /*	pscsi_get_device_type():
1352  *
1353  *
1354  */
1355 static u32 pscsi_get_device_type(struct se_device *dev)
1356 {
1357 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1358 	struct scsi_device *sd = pdv->pdv_sd;
1359 
1360 	return sd->type;
1361 }
1362 
1363 static sector_t pscsi_get_blocks(struct se_device *dev)
1364 {
1365 	struct pscsi_dev_virt *pdv = dev->dev_ptr;
1366 
1367 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1368 		return pdv->pdv_bd->bd_part->nr_sects;
1369 
1370 	dump_stack();
1371 	return 0;
1372 }
1373 
1374 /*	pscsi_handle_SAM_STATUS_failures():
1375  *
1376  *
1377  */
1378 static inline void pscsi_process_SAM_status(
1379 	struct se_task *task,
1380 	struct pscsi_plugin_task *pt)
1381 {
1382 	task->task_scsi_status = status_byte(pt->pscsi_result);
1383 	if ((task->task_scsi_status)) {
1384 		task->task_scsi_status <<= 1;
1385 		printk(KERN_INFO "PSCSI Status Byte exception at task: %p CDB:"
1386 			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
1387 			pt->pscsi_result);
1388 	}
1389 
1390 	switch (host_byte(pt->pscsi_result)) {
1391 	case DID_OK:
1392 		transport_complete_task(task, (!task->task_scsi_status));
1393 		break;
1394 	default:
1395 		printk(KERN_INFO "PSCSI Host Byte exception at task: %p CDB:"
1396 			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
1397 			pt->pscsi_result);
1398 		task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
1399 		task->task_error_status = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
1400 		TASK_CMD(task)->transport_error_status =
1401 					PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
1402 		transport_complete_task(task, 0);
1403 		break;
1404 	}
1405 
1406 	return;
1407 }
1408 
1409 static void pscsi_req_done(struct request *req, int uptodate)
1410 {
1411 	struct se_task *task = req->end_io_data;
1412 	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
1413 
1414 	pt->pscsi_result = req->errors;
1415 	pt->pscsi_resid = req->resid_len;
1416 
1417 	pscsi_process_SAM_status(task, pt);
1418 	/*
1419 	 * Release BIDI-READ if present
1420 	 */
1421 	if (req->next_rq != NULL)
1422 		__blk_put_request(req->q, req->next_rq);
1423 
1424 	__blk_put_request(req->q, req);
1425 	pt->pscsi_req = NULL;
1426 }
1427 
1428 static struct se_subsystem_api pscsi_template = {
1429 	.name			= "pscsi",
1430 	.owner			= THIS_MODULE,
1431 	.transport_type		= TRANSPORT_PLUGIN_PHBA_PDEV,
1432 	.cdb_none		= pscsi_CDB_none,
1433 	.map_task_non_SG	= pscsi_map_task_non_SG,
1434 	.map_task_SG		= pscsi_map_task_SG,
1435 	.attach_hba		= pscsi_attach_hba,
1436 	.detach_hba		= pscsi_detach_hba,
1437 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1438 	.allocate_virtdevice	= pscsi_allocate_virtdevice,
1439 	.create_virtdevice	= pscsi_create_virtdevice,
1440 	.free_device		= pscsi_free_device,
1441 	.transport_complete	= pscsi_transport_complete,
1442 	.alloc_task		= pscsi_alloc_task,
1443 	.do_task		= pscsi_do_task,
1444 	.free_task		= pscsi_free_task,
1445 	.check_configfs_dev_params = pscsi_check_configfs_dev_params,
1446 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1447 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1448 	.get_cdb		= pscsi_get_cdb,
1449 	.get_sense_buffer	= pscsi_get_sense_buffer,
1450 	.get_device_rev		= pscsi_get_device_rev,
1451 	.get_device_type	= pscsi_get_device_type,
1452 	.get_blocks		= pscsi_get_blocks,
1453 };
1454 
1455 static int __init pscsi_module_init(void)
1456 {
1457 	return transport_subsystem_register(&pscsi_template);
1458 }
1459 
1460 static void pscsi_module_exit(void)
1461 {
1462 	transport_subsystem_release(&pscsi_template);
1463 }
1464 
1465 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1466 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1467 MODULE_LICENSE("GPL");
1468 
1469 module_init(pscsi_module_init);
1470 module_exit(pscsi_module_exit);
1471