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.h>
40#include <scsi/scsi_device.h>
41#include <scsi/scsi_cmnd.h>
42#include <scsi/scsi_host.h>
43#include <scsi/scsi_tcq.h>
44
45#include <target/target_core_base.h>
46#include <target/target_core_backend.h>
47#include <target/target_core_backend_configfs.h>
48
49#include "target_core_alua.h"
50#include "target_core_pscsi.h"
51
52#define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
53
54static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
55{
56	return container_of(dev, struct pscsi_dev_virt, dev);
57}
58
59static struct se_subsystem_api pscsi_template;
60
61static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
62static void pscsi_req_done(struct request *, int);
63
64/*	pscsi_attach_hba():
65 *
66 * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
67 *	from the passed SCSI Host ID.
68 */
69static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
70{
71	struct pscsi_hba_virt *phv;
72
73	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
74	if (!phv) {
75		pr_err("Unable to allocate struct pscsi_hba_virt\n");
76		return -ENOMEM;
77	}
78	phv->phv_host_id = host_id;
79	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
80
81	hba->hba_ptr = phv;
82
83	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
84		" Generic Target Core Stack %s\n", hba->hba_id,
85		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
86	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
87	       hba->hba_id);
88
89	return 0;
90}
91
92static void pscsi_detach_hba(struct se_hba *hba)
93{
94	struct pscsi_hba_virt *phv = hba->hba_ptr;
95	struct Scsi_Host *scsi_host = phv->phv_lld_host;
96
97	if (scsi_host) {
98		scsi_host_put(scsi_host);
99
100		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
101			" Generic Target Core\n", hba->hba_id,
102			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
103			"Unknown");
104	} else
105		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
106			" from Generic Target Core\n", hba->hba_id);
107
108	kfree(phv);
109	hba->hba_ptr = NULL;
110}
111
112static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
113{
114	struct pscsi_hba_virt *phv = hba->hba_ptr;
115	struct Scsi_Host *sh = phv->phv_lld_host;
116	/*
117	 * Release the struct Scsi_Host
118	 */
119	if (!mode_flag) {
120		if (!sh)
121			return 0;
122
123		phv->phv_lld_host = NULL;
124		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
125
126		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
127			" %s\n", hba->hba_id, (sh->hostt->name) ?
128			(sh->hostt->name) : "Unknown");
129
130		scsi_host_put(sh);
131		return 0;
132	}
133	/*
134	 * Otherwise, locate struct Scsi_Host from the original passed
135	 * pSCSI Host ID and enable for phba mode
136	 */
137	sh = scsi_host_lookup(phv->phv_host_id);
138	if (!sh) {
139		pr_err("pSCSI: Unable to locate SCSI Host for"
140			" phv_host_id: %d\n", phv->phv_host_id);
141		return -EINVAL;
142	}
143
144	phv->phv_lld_host = sh;
145	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
146
147	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
148		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
149
150	return 1;
151}
152
153static void pscsi_tape_read_blocksize(struct se_device *dev,
154		struct scsi_device *sdev)
155{
156	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
157	int ret;
158
159	buf = kzalloc(12, GFP_KERNEL);
160	if (!buf)
161		return;
162
163	memset(cdb, 0, MAX_COMMAND_SIZE);
164	cdb[0] = MODE_SENSE;
165	cdb[4] = 0x0c; /* 12 bytes */
166
167	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
168			HZ, 1, NULL);
169	if (ret)
170		goto out_free;
171
172	/*
173	 * If MODE_SENSE still returns zero, set the default value to 1024.
174	 */
175	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
176	if (!sdev->sector_size)
177		sdev->sector_size = 1024;
178out_free:
179	kfree(buf);
180}
181
182static void
183pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
184{
185	unsigned char *buf;
186
187	if (sdev->inquiry_len < INQUIRY_LEN)
188		return;
189
190	buf = sdev->inquiry;
191	if (!buf)
192		return;
193	/*
194	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
195	 */
196	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
197	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
198	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
199}
200
201static int
202pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
203{
204	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
205	int ret;
206
207	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
208	if (!buf)
209		return -ENOMEM;
210
211	memset(cdb, 0, MAX_COMMAND_SIZE);
212	cdb[0] = INQUIRY;
213	cdb[1] = 0x01; /* Query VPD */
214	cdb[2] = 0x80; /* Unit Serial Number */
215	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
216	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
217
218	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
219			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
220	if (ret)
221		goto out_free;
222
223	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
224
225	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
226
227	kfree(buf);
228	return 0;
229
230out_free:
231	kfree(buf);
232	return -EPERM;
233}
234
235static void
236pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
237		struct t10_wwn *wwn)
238{
239	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
240	int ident_len, page_len, off = 4, ret;
241	struct t10_vpd *vpd;
242
243	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
244	if (!buf)
245		return;
246
247	memset(cdb, 0, MAX_COMMAND_SIZE);
248	cdb[0] = INQUIRY;
249	cdb[1] = 0x01; /* Query VPD */
250	cdb[2] = 0x83; /* Device Identifier */
251	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
252	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
253
254	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
255			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
256			      NULL, HZ, 1, NULL);
257	if (ret)
258		goto out;
259
260	page_len = (buf[2] << 8) | buf[3];
261	while (page_len > 0) {
262		/* Grab a pointer to the Identification descriptor */
263		page_83 = &buf[off];
264		ident_len = page_83[3];
265		if (!ident_len) {
266			pr_err("page_83[3]: identifier"
267					" length zero!\n");
268			break;
269		}
270		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
271
272		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
273		if (!vpd) {
274			pr_err("Unable to allocate memory for"
275					" struct t10_vpd\n");
276			goto out;
277		}
278		INIT_LIST_HEAD(&vpd->vpd_list);
279
280		transport_set_vpd_proto_id(vpd, page_83);
281		transport_set_vpd_assoc(vpd, page_83);
282
283		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
284			off += (ident_len + 4);
285			page_len -= (ident_len + 4);
286			kfree(vpd);
287			continue;
288		}
289		if (transport_set_vpd_ident(vpd, page_83) < 0) {
290			off += (ident_len + 4);
291			page_len -= (ident_len + 4);
292			kfree(vpd);
293			continue;
294		}
295
296		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
297		off += (ident_len + 4);
298		page_len -= (ident_len + 4);
299	}
300
301out:
302	kfree(buf);
303}
304
305static int pscsi_add_device_to_list(struct se_device *dev,
306		struct scsi_device *sd)
307{
308	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
309	struct request_queue *q = sd->request_queue;
310
311	pdv->pdv_sd = sd;
312
313	if (!sd->queue_depth) {
314		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
315
316		pr_err("Set broken SCSI Device %d:%d:%llu"
317			" queue_depth to %d\n", sd->channel, sd->id,
318				sd->lun, sd->queue_depth);
319	}
320
321	dev->dev_attrib.hw_block_size = sd->sector_size;
322	dev->dev_attrib.hw_max_sectors =
323		min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
324	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
325
326	/*
327	 * Setup our standard INQUIRY info into se_dev->t10_wwn
328	 */
329	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
330
331	/*
332	 * Locate VPD WWN Information used for various purposes within
333	 * the Storage Engine.
334	 */
335	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
336		/*
337		 * If VPD Unit Serial returned GOOD status, try
338		 * VPD Device Identification page (0x83).
339		 */
340		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
341	}
342
343	/*
344	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
345	 */
346	if (sd->type == TYPE_TAPE)
347		pscsi_tape_read_blocksize(dev, sd);
348	return 0;
349}
350
351static struct se_device *pscsi_alloc_device(struct se_hba *hba,
352		const char *name)
353{
354	struct pscsi_dev_virt *pdv;
355
356	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
357	if (!pdv) {
358		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
359		return NULL;
360	}
361
362	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
363	return &pdv->dev;
364}
365
366/*
367 * Called with struct Scsi_Host->host_lock called.
368 */
369static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
370	__releases(sh->host_lock)
371{
372	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
373	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
374	struct Scsi_Host *sh = sd->host;
375	struct block_device *bd;
376	int ret;
377
378	if (scsi_device_get(sd)) {
379		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
380			sh->host_no, sd->channel, sd->id, sd->lun);
381		spin_unlock_irq(sh->host_lock);
382		return -EIO;
383	}
384	spin_unlock_irq(sh->host_lock);
385	/*
386	 * Claim exclusive struct block_device access to struct scsi_device
387	 * for TYPE_DISK using supplied udev_path
388	 */
389	bd = blkdev_get_by_path(dev->udev_path,
390				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
391	if (IS_ERR(bd)) {
392		pr_err("pSCSI: blkdev_get_by_path() failed\n");
393		scsi_device_put(sd);
394		return PTR_ERR(bd);
395	}
396	pdv->pdv_bd = bd;
397
398	ret = pscsi_add_device_to_list(dev, sd);
399	if (ret) {
400		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
401		scsi_device_put(sd);
402		return ret;
403	}
404
405	pr_debug("CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%llu\n",
406		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
407	return 0;
408}
409
410/*
411 * Called with struct Scsi_Host->host_lock called.
412 */
413static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
414	__releases(sh->host_lock)
415{
416	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
417	struct Scsi_Host *sh = sd->host;
418	int ret;
419
420	if (scsi_device_get(sd)) {
421		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
422			sh->host_no, sd->channel, sd->id, sd->lun);
423		spin_unlock_irq(sh->host_lock);
424		return -EIO;
425	}
426	spin_unlock_irq(sh->host_lock);
427
428	ret = pscsi_add_device_to_list(dev, sd);
429	if (ret) {
430		scsi_device_put(sd);
431		return ret;
432	}
433	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
434		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
435		sd->channel, sd->id, sd->lun);
436
437	return 0;
438}
439
440/*
441 * Called with struct Scsi_Host->host_lock called.
442 */
443static int pscsi_create_type_other(struct se_device *dev,
444		struct scsi_device *sd)
445	__releases(sh->host_lock)
446{
447	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
448	struct Scsi_Host *sh = sd->host;
449	int ret;
450
451	spin_unlock_irq(sh->host_lock);
452	ret = pscsi_add_device_to_list(dev, sd);
453	if (ret)
454		return ret;
455
456	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
457		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
458		sd->channel, sd->id, sd->lun);
459	return 0;
460}
461
462static int pscsi_configure_device(struct se_device *dev)
463{
464	struct se_hba *hba = dev->se_hba;
465	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
466	struct scsi_device *sd;
467	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
468	struct Scsi_Host *sh = phv->phv_lld_host;
469	int legacy_mode_enable = 0;
470	int ret;
471
472	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
473	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
474	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
475		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
476			" scsi_lun_id= parameters\n");
477		return -EINVAL;
478	}
479
480	/*
481	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
482	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
483	 */
484	if (!sh) {
485		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
486			pr_err("pSCSI: Unable to locate struct"
487				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
488			return -ENODEV;
489		}
490		/*
491		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
492		 * reference, we enforce that udev_path has been set
493		 */
494		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
495			pr_err("pSCSI: udev_path attribute has not"
496				" been set before ENABLE=1\n");
497			return -EINVAL;
498		}
499		/*
500		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
501		 * use the original TCM hba ID to reference Linux/SCSI Host No
502		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
503		 */
504		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
505			if (hba->dev_count) {
506				pr_err("pSCSI: Unable to set hba_mode"
507					" with active devices\n");
508				return -EEXIST;
509			}
510
511			if (pscsi_pmode_enable_hba(hba, 1) != 1)
512				return -ENODEV;
513
514			legacy_mode_enable = 1;
515			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
516			sh = phv->phv_lld_host;
517		} else {
518			sh = scsi_host_lookup(pdv->pdv_host_id);
519			if (!sh) {
520				pr_err("pSCSI: Unable to locate"
521					" pdv_host_id: %d\n", pdv->pdv_host_id);
522				return -EINVAL;
523			}
524			pdv->pdv_lld_host = sh;
525		}
526	} else {
527		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
528			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
529				" struct Scsi_Host exists\n");
530			return -EEXIST;
531		}
532	}
533
534	spin_lock_irq(sh->host_lock);
535	list_for_each_entry(sd, &sh->__devices, siblings) {
536		if ((pdv->pdv_channel_id != sd->channel) ||
537		    (pdv->pdv_target_id != sd->id) ||
538		    (pdv->pdv_lun_id != sd->lun))
539			continue;
540		/*
541		 * Functions will release the held struct scsi_host->host_lock
542		 * before calling calling pscsi_add_device_to_list() to register
543		 * struct scsi_device with target_core_mod.
544		 */
545		switch (sd->type) {
546		case TYPE_DISK:
547			ret = pscsi_create_type_disk(dev, sd);
548			break;
549		case TYPE_ROM:
550			ret = pscsi_create_type_rom(dev, sd);
551			break;
552		default:
553			ret = pscsi_create_type_other(dev, sd);
554			break;
555		}
556
557		if (ret) {
558			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
559				scsi_host_put(sh);
560			else if (legacy_mode_enable) {
561				pscsi_pmode_enable_hba(hba, 0);
562				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
563			}
564			pdv->pdv_sd = NULL;
565			return ret;
566		}
567		return 0;
568	}
569	spin_unlock_irq(sh->host_lock);
570
571	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
572		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
573
574	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
575		scsi_host_put(sh);
576	else if (legacy_mode_enable) {
577		pscsi_pmode_enable_hba(hba, 0);
578		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
579	}
580
581	return -ENODEV;
582}
583
584static void pscsi_free_device(struct se_device *dev)
585{
586	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
587	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
588	struct scsi_device *sd = pdv->pdv_sd;
589
590	if (sd) {
591		/*
592		 * Release exclusive pSCSI internal struct block_device claim for
593		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
594		 */
595		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
596			blkdev_put(pdv->pdv_bd,
597				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
598			pdv->pdv_bd = NULL;
599		}
600		/*
601		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
602		 * to struct Scsi_Host now.
603		 */
604		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
605		    (phv->phv_lld_host != NULL))
606			scsi_host_put(phv->phv_lld_host);
607		else if (pdv->pdv_lld_host)
608			scsi_host_put(pdv->pdv_lld_host);
609
610		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
611			scsi_device_put(sd);
612
613		pdv->pdv_sd = NULL;
614	}
615
616	kfree(pdv);
617}
618
619static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
620				     unsigned char *sense_buffer)
621{
622	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
623	struct scsi_device *sd = pdv->pdv_sd;
624	int result;
625	struct pscsi_plugin_task *pt = cmd->priv;
626	unsigned char *cdb;
627	/*
628	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
629	 * not been allocated because TCM is handling the emulation directly.
630	 */
631	if (!pt)
632		return;
633
634	cdb = &pt->pscsi_cdb[0];
635	result = pt->pscsi_result;
636	/*
637	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
638	 * forced.
639	 */
640	if (!cmd->se_deve || !cmd->data_length)
641		goto after_mode_sense;
642
643	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
644	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
645		if (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY) {
646			unsigned char *buf;
647
648			buf = transport_kmap_data_sg(cmd);
649			if (!buf)
650				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
651
652			if (cdb[0] == MODE_SENSE_10) {
653				if (!(buf[3] & 0x80))
654					buf[3] |= 0x80;
655			} else {
656				if (!(buf[2] & 0x80))
657					buf[2] |= 0x80;
658			}
659
660			transport_kunmap_data_sg(cmd);
661		}
662	}
663after_mode_sense:
664
665	if (sd->type != TYPE_TAPE || !cmd->data_length)
666		goto after_mode_select;
667
668	/*
669	 * Hack to correctly obtain the initiator requested blocksize for
670	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
671	 * struct scsi_device->sector_size will not contain the correct value
672	 * by default, so we go ahead and set it so
673	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
674	 * storage engine.
675	 */
676	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
677	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
678		unsigned char *buf;
679		u16 bdl;
680		u32 blocksize;
681
682		buf = sg_virt(&sg[0]);
683		if (!buf) {
684			pr_err("Unable to get buf for scatterlist\n");
685			goto after_mode_select;
686		}
687
688		if (cdb[0] == MODE_SELECT)
689			bdl = (buf[3]);
690		else
691			bdl = (buf[6] << 8) | (buf[7]);
692
693		if (!bdl)
694			goto after_mode_select;
695
696		if (cdb[0] == MODE_SELECT)
697			blocksize = (buf[9] << 16) | (buf[10] << 8) |
698					(buf[11]);
699		else
700			blocksize = (buf[13] << 16) | (buf[14] << 8) |
701					(buf[15]);
702
703		sd->sector_size = blocksize;
704	}
705after_mode_select:
706
707	if (sense_buffer && (status_byte(result) & CHECK_CONDITION)) {
708		memcpy(sense_buffer, pt->pscsi_sense, TRANSPORT_SENSE_BUFFER);
709		cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
710	}
711}
712
713enum {
714	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
715	Opt_scsi_lun_id, Opt_err
716};
717
718static match_table_t tokens = {
719	{Opt_scsi_host_id, "scsi_host_id=%d"},
720	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
721	{Opt_scsi_target_id, "scsi_target_id=%d"},
722	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
723	{Opt_err, NULL}
724};
725
726static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
727		const char *page, ssize_t count)
728{
729	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
730	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
731	char *orig, *ptr, *opts;
732	substring_t args[MAX_OPT_ARGS];
733	int ret = 0, arg, token;
734
735	opts = kstrdup(page, GFP_KERNEL);
736	if (!opts)
737		return -ENOMEM;
738
739	orig = opts;
740
741	while ((ptr = strsep(&opts, ",\n")) != NULL) {
742		if (!*ptr)
743			continue;
744
745		token = match_token(ptr, tokens, args);
746		switch (token) {
747		case Opt_scsi_host_id:
748			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
749				pr_err("PSCSI[%d]: Unable to accept"
750					" scsi_host_id while phv_mode =="
751					" PHV_LLD_SCSI_HOST_NO\n",
752					phv->phv_host_id);
753				ret = -EINVAL;
754				goto out;
755			}
756			ret = match_int(args, &arg);
757			if (ret)
758				goto out;
759			pdv->pdv_host_id = arg;
760			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
761				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
762			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
763			break;
764		case Opt_scsi_channel_id:
765			ret = match_int(args, &arg);
766			if (ret)
767				goto out;
768			pdv->pdv_channel_id = arg;
769			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
770				" ID: %d\n",  phv->phv_host_id,
771				pdv->pdv_channel_id);
772			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
773			break;
774		case Opt_scsi_target_id:
775			ret = match_int(args, &arg);
776			if (ret)
777				goto out;
778			pdv->pdv_target_id = arg;
779			pr_debug("PSCSI[%d]: Referencing SCSI Target"
780				" ID: %d\n", phv->phv_host_id,
781				pdv->pdv_target_id);
782			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
783			break;
784		case Opt_scsi_lun_id:
785			ret = match_int(args, &arg);
786			if (ret)
787				goto out;
788			pdv->pdv_lun_id = arg;
789			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
790				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
791			pdv->pdv_flags |= PDF_HAS_LUN_ID;
792			break;
793		default:
794			break;
795		}
796	}
797
798out:
799	kfree(orig);
800	return (!ret) ? count : ret;
801}
802
803static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
804{
805	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
806	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
807	struct scsi_device *sd = pdv->pdv_sd;
808	unsigned char host_id[16];
809	ssize_t bl;
810	int i;
811
812	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
813		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
814	else
815		snprintf(host_id, 16, "PHBA Mode");
816
817	bl = sprintf(b, "SCSI Device Bus Location:"
818		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
819		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
820		host_id);
821
822	if (sd) {
823		bl += sprintf(b + bl, "        ");
824		bl += sprintf(b + bl, "Vendor: ");
825		for (i = 0; i < 8; i++) {
826			if (ISPRINT(sd->vendor[i]))   /* printable character? */
827				bl += sprintf(b + bl, "%c", sd->vendor[i]);
828			else
829				bl += sprintf(b + bl, " ");
830		}
831		bl += sprintf(b + bl, " Model: ");
832		for (i = 0; i < 16; i++) {
833			if (ISPRINT(sd->model[i]))   /* printable character ? */
834				bl += sprintf(b + bl, "%c", sd->model[i]);
835			else
836				bl += sprintf(b + bl, " ");
837		}
838		bl += sprintf(b + bl, " Rev: ");
839		for (i = 0; i < 4; i++) {
840			if (ISPRINT(sd->rev[i]))   /* printable character ? */
841				bl += sprintf(b + bl, "%c", sd->rev[i]);
842			else
843				bl += sprintf(b + bl, " ");
844		}
845		bl += sprintf(b + bl, "\n");
846	}
847	return bl;
848}
849
850static void pscsi_bi_endio(struct bio *bio, int error)
851{
852	bio_put(bio);
853}
854
855static inline struct bio *pscsi_get_bio(int nr_vecs)
856{
857	struct bio *bio;
858	/*
859	 * Use bio_malloc() following the comment in for bio -> struct request
860	 * in block/blk-core.c:blk_make_request()
861	 */
862	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
863	if (!bio) {
864		pr_err("PSCSI: bio_kmalloc() failed\n");
865		return NULL;
866	}
867	bio->bi_end_io = pscsi_bi_endio;
868
869	return bio;
870}
871
872static sense_reason_t
873pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
874		enum dma_data_direction data_direction, struct bio **hbio)
875{
876	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
877	struct bio *bio = NULL, *tbio = NULL;
878	struct page *page;
879	struct scatterlist *sg;
880	u32 data_len = cmd->data_length, i, len, bytes, off;
881	int nr_pages = (cmd->data_length + sgl[0].offset +
882			PAGE_SIZE - 1) >> PAGE_SHIFT;
883	int nr_vecs = 0, rc;
884	int rw = (data_direction == DMA_TO_DEVICE);
885
886	*hbio = NULL;
887
888	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
889
890	for_each_sg(sgl, sg, sgl_nents, i) {
891		page = sg_page(sg);
892		off = sg->offset;
893		len = sg->length;
894
895		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
896			page, len, off);
897
898		/*
899		 * We only have one page of data in each sg element,
900		 * we can not cross a page boundary.
901		 */
902		if (off + len > PAGE_SIZE)
903			goto fail;
904
905		if (len > 0 && data_len > 0) {
906			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
907			bytes = min(bytes, data_len);
908
909			if (!bio) {
910				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
911				nr_pages -= nr_vecs;
912				/*
913				 * Calls bio_kmalloc() and sets bio->bi_end_io()
914				 */
915				bio = pscsi_get_bio(nr_vecs);
916				if (!bio)
917					goto fail;
918
919				if (rw)
920					bio->bi_rw |= REQ_WRITE;
921
922				pr_debug("PSCSI: Allocated bio: %p,"
923					" dir: %s nr_vecs: %d\n", bio,
924					(rw) ? "rw" : "r", nr_vecs);
925				/*
926				 * Set *hbio pointer to handle the case:
927				 * nr_pages > BIO_MAX_PAGES, where additional
928				 * bios need to be added to complete a given
929				 * command.
930				 */
931				if (!*hbio)
932					*hbio = tbio = bio;
933				else
934					tbio = tbio->bi_next = bio;
935			}
936
937			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
938				" bio: %p page: %p len: %d off: %d\n", i, bio,
939				page, len, off);
940
941			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
942					bio, page, bytes, off);
943			if (rc != bytes)
944				goto fail;
945
946			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
947				bio->bi_vcnt, nr_vecs);
948
949			if (bio->bi_vcnt > nr_vecs) {
950				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
951					" %d i: %d bio: %p, allocating another"
952					" bio\n", bio->bi_vcnt, i, bio);
953				/*
954				 * Clear the pointer so that another bio will
955				 * be allocated with pscsi_get_bio() above, the
956				 * current bio has already been set *tbio and
957				 * bio->bi_next.
958				 */
959				bio = NULL;
960			}
961
962			data_len -= bytes;
963		}
964	}
965
966	return 0;
967fail:
968	while (*hbio) {
969		bio = *hbio;
970		*hbio = (*hbio)->bi_next;
971		bio_endio(bio, 0);	/* XXX: should be error */
972	}
973	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
974}
975
976static sense_reason_t
977pscsi_parse_cdb(struct se_cmd *cmd)
978{
979	if (cmd->se_cmd_flags & SCF_BIDI)
980		return TCM_UNSUPPORTED_SCSI_OPCODE;
981
982	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
983}
984
985static sense_reason_t
986pscsi_execute_cmd(struct se_cmd *cmd)
987{
988	struct scatterlist *sgl = cmd->t_data_sg;
989	u32 sgl_nents = cmd->t_data_nents;
990	enum dma_data_direction data_direction = cmd->data_direction;
991	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
992	struct pscsi_plugin_task *pt;
993	struct request *req;
994	struct bio *hbio;
995	sense_reason_t ret;
996
997	/*
998	 * Dynamically alloc cdb space, since it may be larger than
999	 * TCM_MAX_COMMAND_SIZE
1000	 */
1001	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
1002	if (!pt) {
1003		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1004	}
1005	cmd->priv = pt;
1006
1007	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
1008		scsi_command_size(cmd->t_task_cdb));
1009
1010	if (!sgl) {
1011		req = blk_get_request(pdv->pdv_sd->request_queue,
1012				(data_direction == DMA_TO_DEVICE),
1013				GFP_KERNEL);
1014		if (IS_ERR(req)) {
1015			pr_err("PSCSI: blk_get_request() failed\n");
1016			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1017			goto fail;
1018		}
1019
1020		blk_rq_set_block_pc(req);
1021	} else {
1022		BUG_ON(!cmd->data_length);
1023
1024		ret = pscsi_map_sg(cmd, sgl, sgl_nents, data_direction, &hbio);
1025		if (ret)
1026			goto fail;
1027
1028		req = blk_make_request(pdv->pdv_sd->request_queue, hbio,
1029				       GFP_KERNEL);
1030		if (IS_ERR(req)) {
1031			pr_err("pSCSI: blk_make_request() failed\n");
1032			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1033			goto fail_free_bio;
1034		}
1035	}
1036
1037	req->end_io = pscsi_req_done;
1038	req->end_io_data = cmd;
1039	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
1040	req->cmd = &pt->pscsi_cdb[0];
1041	req->sense = &pt->pscsi_sense[0];
1042	req->sense_len = 0;
1043	if (pdv->pdv_sd->type == TYPE_DISK)
1044		req->timeout = PS_TIMEOUT_DISK;
1045	else
1046		req->timeout = PS_TIMEOUT_OTHER;
1047	req->retries = PS_RETRY;
1048
1049	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1050			(cmd->sam_task_attr == TCM_HEAD_TAG),
1051			pscsi_req_done);
1052
1053	return 0;
1054
1055fail_free_bio:
1056	while (hbio) {
1057		struct bio *bio = hbio;
1058		hbio = hbio->bi_next;
1059		bio_endio(bio, 0);	/* XXX: should be error */
1060	}
1061	ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1062fail:
1063	kfree(pt);
1064	return ret;
1065}
1066
1067/*	pscsi_get_device_type():
1068 *
1069 *
1070 */
1071static u32 pscsi_get_device_type(struct se_device *dev)
1072{
1073	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1074	struct scsi_device *sd = pdv->pdv_sd;
1075
1076	return (sd) ? sd->type : TYPE_NO_LUN;
1077}
1078
1079static sector_t pscsi_get_blocks(struct se_device *dev)
1080{
1081	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1082
1083	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1084		return pdv->pdv_bd->bd_part->nr_sects;
1085
1086	dump_stack();
1087	return 0;
1088}
1089
1090static void pscsi_req_done(struct request *req, int uptodate)
1091{
1092	struct se_cmd *cmd = req->end_io_data;
1093	struct pscsi_plugin_task *pt = cmd->priv;
1094
1095	pt->pscsi_result = req->errors;
1096	pt->pscsi_resid = req->resid_len;
1097
1098	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
1099	if (cmd->scsi_status) {
1100		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1101			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1102			pt->pscsi_result);
1103	}
1104
1105	switch (host_byte(pt->pscsi_result)) {
1106	case DID_OK:
1107		target_complete_cmd(cmd, cmd->scsi_status);
1108		break;
1109	default:
1110		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1111			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1112			pt->pscsi_result);
1113		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1114		break;
1115	}
1116
1117	__blk_put_request(req->q, req);
1118	kfree(pt);
1119}
1120
1121DEF_TB_DEV_ATTRIB_RO(pscsi, hw_pi_prot_type);
1122TB_DEV_ATTR_RO(pscsi, hw_pi_prot_type);
1123
1124DEF_TB_DEV_ATTRIB_RO(pscsi, hw_block_size);
1125TB_DEV_ATTR_RO(pscsi, hw_block_size);
1126
1127DEF_TB_DEV_ATTRIB_RO(pscsi, hw_max_sectors);
1128TB_DEV_ATTR_RO(pscsi, hw_max_sectors);
1129
1130DEF_TB_DEV_ATTRIB_RO(pscsi, hw_queue_depth);
1131TB_DEV_ATTR_RO(pscsi, hw_queue_depth);
1132
1133static struct configfs_attribute *pscsi_backend_dev_attrs[] = {
1134	&pscsi_dev_attrib_hw_pi_prot_type.attr,
1135	&pscsi_dev_attrib_hw_block_size.attr,
1136	&pscsi_dev_attrib_hw_max_sectors.attr,
1137	&pscsi_dev_attrib_hw_queue_depth.attr,
1138	NULL,
1139};
1140
1141static struct se_subsystem_api pscsi_template = {
1142	.name			= "pscsi",
1143	.owner			= THIS_MODULE,
1144	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH,
1145	.attach_hba		= pscsi_attach_hba,
1146	.detach_hba		= pscsi_detach_hba,
1147	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1148	.alloc_device		= pscsi_alloc_device,
1149	.configure_device	= pscsi_configure_device,
1150	.free_device		= pscsi_free_device,
1151	.transport_complete	= pscsi_transport_complete,
1152	.parse_cdb		= pscsi_parse_cdb,
1153	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1154	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1155	.get_device_type	= pscsi_get_device_type,
1156	.get_blocks		= pscsi_get_blocks,
1157};
1158
1159static int __init pscsi_module_init(void)
1160{
1161	struct target_backend_cits *tbc = &pscsi_template.tb_cits;
1162
1163	target_core_setup_sub_cits(&pscsi_template);
1164	tbc->tb_dev_attrib_cit.ct_attrs = pscsi_backend_dev_attrs;
1165
1166	return transport_subsystem_register(&pscsi_template);
1167}
1168
1169static void __exit pscsi_module_exit(void)
1170{
1171	transport_subsystem_release(&pscsi_template);
1172}
1173
1174MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1175MODULE_AUTHOR("nab@Linux-iSCSI.org");
1176MODULE_LICENSE("GPL");
1177
1178module_init(pscsi_module_init);
1179module_exit(pscsi_module_exit);
1180