1/*
2 * LSI/Engenio/NetApp E-Series RDAC SCSI Device Handler
3 *
4 * Copyright (C) 2005 Mike Christie. All rights reserved.
5 * Copyright (C) Chandra Seetharaman, IBM Corp. 2007
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 */
22#include <scsi/scsi.h>
23#include <scsi/scsi_eh.h>
24#include <scsi/scsi_dh.h>
25#include <linux/workqueue.h>
26#include <linux/slab.h>
27#include <linux/module.h>
28
29#define RDAC_NAME "rdac"
30#define RDAC_RETRY_COUNT 5
31
32/*
33 * LSI mode page stuff
34 *
35 * These struct definitions and the forming of the
36 * mode page were taken from the LSI RDAC 2.4 GPL'd
37 * driver, and then converted to Linux conventions.
38 */
39#define RDAC_QUIESCENCE_TIME 20
40/*
41 * Page Codes
42 */
43#define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
44
45/*
46 * Controller modes definitions
47 */
48#define RDAC_MODE_TRANSFER_SPECIFIED_LUNS	0x02
49
50/*
51 * RDAC Options field
52 */
53#define RDAC_FORCED_QUIESENCE 0x02
54
55#define RDAC_TIMEOUT	(60 * HZ)
56#define RDAC_RETRIES	3
57
58struct rdac_mode_6_hdr {
59	u8	data_len;
60	u8	medium_type;
61	u8	device_params;
62	u8	block_desc_len;
63};
64
65struct rdac_mode_10_hdr {
66	u16	data_len;
67	u8	medium_type;
68	u8	device_params;
69	u16	reserved;
70	u16	block_desc_len;
71};
72
73struct rdac_mode_common {
74	u8	controller_serial[16];
75	u8	alt_controller_serial[16];
76	u8	rdac_mode[2];
77	u8	alt_rdac_mode[2];
78	u8	quiescence_timeout;
79	u8	rdac_options;
80};
81
82struct rdac_pg_legacy {
83	struct rdac_mode_6_hdr hdr;
84	u8	page_code;
85	u8	page_len;
86	struct rdac_mode_common common;
87#define MODE6_MAX_LUN	32
88	u8	lun_table[MODE6_MAX_LUN];
89	u8	reserved2[32];
90	u8	reserved3;
91	u8	reserved4;
92};
93
94struct rdac_pg_expanded {
95	struct rdac_mode_10_hdr hdr;
96	u8	page_code;
97	u8	subpage_code;
98	u8	page_len[2];
99	struct rdac_mode_common common;
100	u8	lun_table[256];
101	u8	reserved3;
102	u8	reserved4;
103};
104
105struct c9_inquiry {
106	u8	peripheral_info;
107	u8	page_code;	/* 0xC9 */
108	u8	reserved1;
109	u8	page_len;
110	u8	page_id[4];	/* "vace" */
111	u8	avte_cvp;
112	u8	path_prio;
113	u8	reserved2[38];
114};
115
116#define SUBSYS_ID_LEN	16
117#define SLOT_ID_LEN	2
118#define ARRAY_LABEL_LEN	31
119
120struct c4_inquiry {
121	u8	peripheral_info;
122	u8	page_code;	/* 0xC4 */
123	u8	reserved1;
124	u8	page_len;
125	u8	page_id[4];	/* "subs" */
126	u8	subsys_id[SUBSYS_ID_LEN];
127	u8	revision[4];
128	u8	slot_id[SLOT_ID_LEN];
129	u8	reserved[2];
130};
131
132#define UNIQUE_ID_LEN 16
133struct c8_inquiry {
134	u8	peripheral_info;
135	u8	page_code; /* 0xC8 */
136	u8	reserved1;
137	u8	page_len;
138	u8	page_id[4]; /* "edid" */
139	u8	reserved2[3];
140	u8	vol_uniq_id_len;
141	u8	vol_uniq_id[16];
142	u8	vol_user_label_len;
143	u8	vol_user_label[60];
144	u8	array_uniq_id_len;
145	u8	array_unique_id[UNIQUE_ID_LEN];
146	u8	array_user_label_len;
147	u8	array_user_label[60];
148	u8	lun[8];
149};
150
151struct rdac_controller {
152	u8			array_id[UNIQUE_ID_LEN];
153	int			use_ms10;
154	struct kref		kref;
155	struct list_head	node; /* list of all controllers */
156	union			{
157		struct rdac_pg_legacy legacy;
158		struct rdac_pg_expanded expanded;
159	} mode_select;
160	u8	index;
161	u8	array_name[ARRAY_LABEL_LEN];
162	struct Scsi_Host	*host;
163	spinlock_t		ms_lock;
164	int			ms_queued;
165	struct work_struct	ms_work;
166	struct scsi_device	*ms_sdev;
167	struct list_head	ms_head;
168	struct list_head	dh_list;
169};
170
171struct c2_inquiry {
172	u8	peripheral_info;
173	u8	page_code;	/* 0xC2 */
174	u8	reserved1;
175	u8	page_len;
176	u8	page_id[4];	/* "swr4" */
177	u8	sw_version[3];
178	u8	sw_date[3];
179	u8	features_enabled;
180	u8	max_lun_supported;
181	u8	partitions[239]; /* Total allocation length should be 0xFF */
182};
183
184struct rdac_dh_data {
185	struct list_head	node;
186	struct rdac_controller	*ctlr;
187	struct scsi_device	*sdev;
188#define UNINITIALIZED_LUN	(1 << 8)
189	unsigned		lun;
190
191#define RDAC_MODE		0
192#define RDAC_MODE_AVT		1
193#define RDAC_MODE_IOSHIP	2
194	unsigned char		mode;
195
196#define RDAC_STATE_ACTIVE	0
197#define RDAC_STATE_PASSIVE	1
198	unsigned char		state;
199
200#define RDAC_LUN_UNOWNED	0
201#define RDAC_LUN_OWNED		1
202	char			lun_state;
203
204#define RDAC_PREFERRED		0
205#define RDAC_NON_PREFERRED	1
206	char			preferred;
207
208	union			{
209		struct c2_inquiry c2;
210		struct c4_inquiry c4;
211		struct c8_inquiry c8;
212		struct c9_inquiry c9;
213	} inq;
214};
215
216static const char *mode[] = {
217	"RDAC",
218	"AVT",
219	"IOSHIP",
220};
221static const char *lun_state[] =
222{
223	"unowned",
224	"owned",
225};
226
227struct rdac_queue_data {
228	struct list_head	entry;
229	struct rdac_dh_data	*h;
230	activate_complete	callback_fn;
231	void			*callback_data;
232};
233
234static LIST_HEAD(ctlr_list);
235static DEFINE_SPINLOCK(list_lock);
236static struct workqueue_struct *kmpath_rdacd;
237static void send_mode_select(struct work_struct *work);
238
239/*
240 * module parameter to enable rdac debug logging.
241 * 2 bits for each type of logging, only two types defined for now
242 * Can be enhanced if required at later point
243 */
244static int rdac_logging = 1;
245module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
246MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
247		"Default is 1 - failover logging enabled, "
248		"set it to 0xF to enable all the logs");
249
250#define RDAC_LOG_FAILOVER	0
251#define RDAC_LOG_SENSE		2
252
253#define RDAC_LOG_BITS		2
254
255#define RDAC_LOG_LEVEL(SHIFT)  \
256	((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
257
258#define RDAC_LOG(SHIFT, sdev, f, arg...) \
259do { \
260	if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
261		sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
262} while (0);
263
264static unsigned int rdac_failover_get(struct rdac_controller *ctlr,
265				      struct list_head *list,
266				      unsigned char *cdb)
267{
268	struct rdac_mode_common *common;
269	unsigned data_size;
270	struct rdac_queue_data *qdata;
271	u8 *lun_table;
272
273	if (ctlr->use_ms10) {
274		struct rdac_pg_expanded *rdac_pg;
275
276		data_size = sizeof(struct rdac_pg_expanded);
277		rdac_pg = &ctlr->mode_select.expanded;
278		memset(rdac_pg, 0, data_size);
279		common = &rdac_pg->common;
280		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
281		rdac_pg->subpage_code = 0x1;
282		rdac_pg->page_len[0] = 0x01;
283		rdac_pg->page_len[1] = 0x28;
284		lun_table = rdac_pg->lun_table;
285	} else {
286		struct rdac_pg_legacy *rdac_pg;
287
288		data_size = sizeof(struct rdac_pg_legacy);
289		rdac_pg = &ctlr->mode_select.legacy;
290		memset(rdac_pg, 0, data_size);
291		common = &rdac_pg->common;
292		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
293		rdac_pg->page_len = 0x68;
294		lun_table = rdac_pg->lun_table;
295	}
296	common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
297	common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
298	common->rdac_options = RDAC_FORCED_QUIESENCE;
299
300	list_for_each_entry(qdata, list, entry) {
301		lun_table[qdata->h->lun] = 0x81;
302	}
303
304	/* Prepare the command. */
305	if (ctlr->use_ms10) {
306		cdb[0] = MODE_SELECT_10;
307		cdb[7] = data_size >> 8;
308		cdb[8] = data_size & 0xff;
309	} else {
310		cdb[0] = MODE_SELECT;
311		cdb[4] = data_size;
312	}
313
314	return data_size;
315}
316
317static void release_controller(struct kref *kref)
318{
319	struct rdac_controller *ctlr;
320	ctlr = container_of(kref, struct rdac_controller, kref);
321
322	list_del(&ctlr->node);
323	kfree(ctlr);
324}
325
326static struct rdac_controller *get_controller(int index, char *array_name,
327			u8 *array_id, struct scsi_device *sdev)
328{
329	struct rdac_controller *ctlr, *tmp;
330
331	list_for_each_entry(tmp, &ctlr_list, node) {
332		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
333			  (tmp->index == index) &&
334			  (tmp->host == sdev->host)) {
335			kref_get(&tmp->kref);
336			return tmp;
337		}
338	}
339	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
340	if (!ctlr)
341		return NULL;
342
343	/* initialize fields of controller */
344	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
345	ctlr->index = index;
346	ctlr->host = sdev->host;
347	memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
348
349	kref_init(&ctlr->kref);
350	ctlr->use_ms10 = -1;
351	ctlr->ms_queued = 0;
352	ctlr->ms_sdev = NULL;
353	spin_lock_init(&ctlr->ms_lock);
354	INIT_WORK(&ctlr->ms_work, send_mode_select);
355	INIT_LIST_HEAD(&ctlr->ms_head);
356	list_add(&ctlr->node, &ctlr_list);
357	INIT_LIST_HEAD(&ctlr->dh_list);
358
359	return ctlr;
360}
361
362static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
363			char *array_name, u8 *array_id)
364{
365	int err = SCSI_DH_IO, i;
366	struct c8_inquiry *inqp = &h->inq.c8;
367
368	if (!scsi_get_vpd_page(sdev, 0xC8, (unsigned char *)inqp,
369			       sizeof(struct c8_inquiry))) {
370		if (inqp->page_code != 0xc8)
371			return SCSI_DH_NOSYS;
372		if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
373		    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
374			return SCSI_DH_NOSYS;
375		h->lun = inqp->lun[7]; /* Uses only the last byte */
376
377		for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
378			*(array_name+i) = inqp->array_user_label[(2*i)+1];
379
380		*(array_name+ARRAY_LABEL_LEN-1) = '\0';
381		memset(array_id, 0, UNIQUE_ID_LEN);
382		memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
383		err = SCSI_DH_OK;
384	}
385	return err;
386}
387
388static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
389{
390	int err = SCSI_DH_IO, access_state;
391	struct rdac_dh_data *tmp;
392	struct c9_inquiry *inqp = &h->inq.c9;
393
394	h->state = RDAC_STATE_ACTIVE;
395	if (!scsi_get_vpd_page(sdev, 0xC9, (unsigned char *)inqp,
396			       sizeof(struct c9_inquiry))) {
397		/* detect the operating mode */
398		if ((inqp->avte_cvp >> 5) & 0x1)
399			h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
400		else if (inqp->avte_cvp >> 7)
401			h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
402		else
403			h->mode = RDAC_MODE; /* LUN in RDAC mode */
404
405		/* Update ownership */
406		if (inqp->avte_cvp & 0x1) {
407			h->lun_state = RDAC_LUN_OWNED;
408			access_state = SCSI_ACCESS_STATE_OPTIMAL;
409		} else {
410			h->lun_state = RDAC_LUN_UNOWNED;
411			if (h->mode == RDAC_MODE) {
412				h->state = RDAC_STATE_PASSIVE;
413				access_state = SCSI_ACCESS_STATE_STANDBY;
414			} else
415				access_state = SCSI_ACCESS_STATE_ACTIVE;
416		}
417
418		/* Update path prio*/
419		if (inqp->path_prio & 0x1) {
420			h->preferred = RDAC_PREFERRED;
421			access_state |= SCSI_ACCESS_STATE_PREFERRED;
422		} else
423			h->preferred = RDAC_NON_PREFERRED;
424		rcu_read_lock();
425		list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
426			/* h->sdev should always be valid */
427			BUG_ON(!tmp->sdev);
428			tmp->sdev->access_state = access_state;
429		}
430		rcu_read_unlock();
431		err = SCSI_DH_OK;
432	}
433
434	return err;
435}
436
437static int initialize_controller(struct scsi_device *sdev,
438		struct rdac_dh_data *h, char *array_name, u8 *array_id)
439{
440	int err = SCSI_DH_IO, index;
441	struct c4_inquiry *inqp = &h->inq.c4;
442
443	if (!scsi_get_vpd_page(sdev, 0xC4, (unsigned char *)inqp,
444			       sizeof(struct c4_inquiry))) {
445		/* get the controller index */
446		if (inqp->slot_id[1] == 0x31)
447			index = 0;
448		else
449			index = 1;
450
451		spin_lock(&list_lock);
452		h->ctlr = get_controller(index, array_name, array_id, sdev);
453		if (!h->ctlr)
454			err = SCSI_DH_RES_TEMP_UNAVAIL;
455		else {
456			h->sdev = sdev;
457			list_add_rcu(&h->node, &h->ctlr->dh_list);
458		}
459		spin_unlock(&list_lock);
460		err = SCSI_DH_OK;
461	}
462	return err;
463}
464
465static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
466{
467	int err = SCSI_DH_IO;
468	struct c2_inquiry *inqp = &h->inq.c2;
469
470	if (!scsi_get_vpd_page(sdev, 0xC2, (unsigned char *)inqp,
471			       sizeof(struct c2_inquiry))) {
472		/*
473		 * If more than MODE6_MAX_LUN luns are supported, use
474		 * mode select 10
475		 */
476		if (inqp->max_lun_supported >= MODE6_MAX_LUN)
477			h->ctlr->use_ms10 = 1;
478		else
479			h->ctlr->use_ms10 = 0;
480		err = SCSI_DH_OK;
481	}
482	return err;
483}
484
485static int mode_select_handle_sense(struct scsi_device *sdev,
486				    struct scsi_sense_hdr *sense_hdr)
487{
488	struct rdac_dh_data *h = sdev->handler_data;
489
490	if (!scsi_sense_valid(sense_hdr))
491		return SCSI_DH_IO;
492
493	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
494		"MODE_SELECT returned with sense %02x/%02x/%02x",
495		(char *) h->ctlr->array_name, h->ctlr->index,
496		sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
497
498	return SCSI_DH_IO;
499}
500
501static void send_mode_select(struct work_struct *work)
502{
503	struct rdac_controller *ctlr =
504		container_of(work, struct rdac_controller, ms_work);
505	struct scsi_device *sdev = ctlr->ms_sdev;
506	struct rdac_dh_data *h = sdev->handler_data;
507	int rc, err;
508	struct rdac_queue_data *tmp, *qdata;
509	LIST_HEAD(list);
510	unsigned char cdb[MAX_COMMAND_SIZE];
511	struct scsi_sense_hdr sshdr;
512	unsigned int data_size;
513	blk_opf_t opf = REQ_OP_DRV_OUT | REQ_FAILFAST_DEV |
514				REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
515	struct scsi_failure failure_defs[] = {
516		{
517			.sense = NO_SENSE,
518			.asc = SCMD_FAILURE_ASC_ANY,
519			.ascq = SCMD_FAILURE_ASCQ_ANY,
520			.result = SAM_STAT_CHECK_CONDITION,
521		},
522		{
523			.sense = ABORTED_COMMAND,
524			.asc = SCMD_FAILURE_ASC_ANY,
525			.ascq = SCMD_FAILURE_ASCQ_ANY,
526			.result = SAM_STAT_CHECK_CONDITION,
527		},
528		{
529			.sense = UNIT_ATTENTION,
530			.asc = SCMD_FAILURE_ASC_ANY,
531			.ascq = SCMD_FAILURE_ASCQ_ANY,
532			.result = SAM_STAT_CHECK_CONDITION,
533		},
534		/* LUN Not Ready and is in the Process of Becoming Ready */
535		{
536			.sense = NOT_READY,
537			.asc = 0x04,
538			.ascq = 0x01,
539			.result = SAM_STAT_CHECK_CONDITION,
540		},
541		/* Command Lock contention */
542		{
543			.sense = ILLEGAL_REQUEST,
544			.asc = 0x91,
545			.ascq = 0x36,
546			.allowed = SCMD_FAILURE_NO_LIMIT,
547			.result = SAM_STAT_CHECK_CONDITION,
548		},
549		{}
550	};
551	struct scsi_failures failures = {
552		.total_allowed = RDAC_RETRY_COUNT,
553		.failure_definitions = failure_defs,
554	};
555	const struct scsi_exec_args exec_args = {
556		.sshdr = &sshdr,
557		.failures = &failures,
558	};
559
560	spin_lock(&ctlr->ms_lock);
561	list_splice_init(&ctlr->ms_head, &list);
562	ctlr->ms_queued = 0;
563	ctlr->ms_sdev = NULL;
564	spin_unlock(&ctlr->ms_lock);
565
566	memset(cdb, 0, sizeof(cdb));
567
568	data_size = rdac_failover_get(ctlr, &list, cdb);
569
570	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, queueing MODE_SELECT command",
571		(char *)h->ctlr->array_name, h->ctlr->index);
572
573	rc = scsi_execute_cmd(sdev, cdb, opf, &h->ctlr->mode_select, data_size,
574			      RDAC_TIMEOUT * HZ, RDAC_RETRIES, &exec_args);
575	if (!rc) {
576		h->state = RDAC_STATE_ACTIVE;
577		RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
578				"MODE_SELECT completed",
579				(char *) h->ctlr->array_name, h->ctlr->index);
580		err = SCSI_DH_OK;
581	} else if (rc < 0) {
582		err = SCSI_DH_IO;
583	} else {
584		err = mode_select_handle_sense(sdev, &sshdr);
585	}
586
587	list_for_each_entry_safe(qdata, tmp, &list, entry) {
588		list_del(&qdata->entry);
589		if (err == SCSI_DH_OK)
590			qdata->h->state = RDAC_STATE_ACTIVE;
591		if (qdata->callback_fn)
592			qdata->callback_fn(qdata->callback_data, err);
593		kfree(qdata);
594	}
595	return;
596}
597
598static int queue_mode_select(struct scsi_device *sdev,
599				activate_complete fn, void *data)
600{
601	struct rdac_queue_data *qdata;
602	struct rdac_controller *ctlr;
603
604	qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
605	if (!qdata)
606		return SCSI_DH_RETRY;
607
608	qdata->h = sdev->handler_data;
609	qdata->callback_fn = fn;
610	qdata->callback_data = data;
611
612	ctlr = qdata->h->ctlr;
613	spin_lock(&ctlr->ms_lock);
614	list_add_tail(&qdata->entry, &ctlr->ms_head);
615	if (!ctlr->ms_queued) {
616		ctlr->ms_queued = 1;
617		ctlr->ms_sdev = sdev;
618		queue_work(kmpath_rdacd, &ctlr->ms_work);
619	}
620	spin_unlock(&ctlr->ms_lock);
621	return SCSI_DH_OK;
622}
623
624static int rdac_activate(struct scsi_device *sdev,
625			activate_complete fn, void *data)
626{
627	struct rdac_dh_data *h = sdev->handler_data;
628	int err = SCSI_DH_OK;
629	int act = 0;
630
631	err = check_ownership(sdev, h);
632	if (err != SCSI_DH_OK)
633		goto done;
634
635	switch (h->mode) {
636	case RDAC_MODE:
637		if (h->lun_state == RDAC_LUN_UNOWNED)
638			act = 1;
639		break;
640	case RDAC_MODE_IOSHIP:
641		if ((h->lun_state == RDAC_LUN_UNOWNED) &&
642		    (h->preferred == RDAC_PREFERRED))
643			act = 1;
644		break;
645	default:
646		break;
647	}
648
649	if (act) {
650		err = queue_mode_select(sdev, fn, data);
651		if (err == SCSI_DH_OK)
652			return 0;
653	}
654done:
655	if (fn)
656		fn(data, err);
657	return 0;
658}
659
660static blk_status_t rdac_prep_fn(struct scsi_device *sdev, struct request *req)
661{
662	struct rdac_dh_data *h = sdev->handler_data;
663
664	if (h->state != RDAC_STATE_ACTIVE) {
665		req->rq_flags |= RQF_QUIET;
666		return BLK_STS_IOERR;
667	}
668
669	return BLK_STS_OK;
670}
671
672static enum scsi_disposition rdac_check_sense(struct scsi_device *sdev,
673					      struct scsi_sense_hdr *sense_hdr)
674{
675	struct rdac_dh_data *h = sdev->handler_data;
676
677	RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
678			"I/O returned with sense %02x/%02x/%02x",
679			(char *) h->ctlr->array_name, h->ctlr->index,
680			sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
681
682	switch (sense_hdr->sense_key) {
683	case NOT_READY:
684		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
685			/* LUN Not Ready - Logical Unit Not Ready and is in
686			* the process of becoming ready
687			* Just retry.
688			*/
689			return ADD_TO_MLQUEUE;
690		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
691			/* LUN Not Ready - Storage firmware incompatible
692			 * Manual code synchonisation required.
693			 *
694			 * Nothing we can do here. Try to bypass the path.
695			 */
696			return SUCCESS;
697		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
698			/* LUN Not Ready - Quiescense in progress
699			 *
700			 * Just retry and wait.
701			 */
702			return ADD_TO_MLQUEUE;
703		if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
704			/* LUN Not Ready - Quiescense in progress
705			 * or has been achieved
706			 * Just retry.
707			 */
708			return ADD_TO_MLQUEUE;
709		break;
710	case ILLEGAL_REQUEST:
711		if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
712			/* Invalid Request - Current Logical Unit Ownership.
713			 * Controller is not the current owner of the LUN,
714			 * Fail the path, so that the other path be used.
715			 */
716			h->state = RDAC_STATE_PASSIVE;
717			return SUCCESS;
718		}
719		break;
720	case UNIT_ATTENTION:
721		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
722			/*
723			 * Power On, Reset, or Bus Device Reset, just retry.
724			 */
725			return ADD_TO_MLQUEUE;
726		if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
727			/*
728			 * Quiescence in progress , just retry.
729			 */
730			return ADD_TO_MLQUEUE;
731		break;
732	}
733	/* success just means we do not care what scsi-ml does */
734	return SCSI_RETURN_NOT_HANDLED;
735}
736
737static int rdac_bus_attach(struct scsi_device *sdev)
738{
739	struct rdac_dh_data *h;
740	int err;
741	char array_name[ARRAY_LABEL_LEN];
742	char array_id[UNIQUE_ID_LEN];
743
744	h = kzalloc(sizeof(*h) , GFP_KERNEL);
745	if (!h)
746		return SCSI_DH_NOMEM;
747	h->lun = UNINITIALIZED_LUN;
748	h->state = RDAC_STATE_ACTIVE;
749
750	err = get_lun_info(sdev, h, array_name, array_id);
751	if (err != SCSI_DH_OK)
752		goto failed;
753
754	err = initialize_controller(sdev, h, array_name, array_id);
755	if (err != SCSI_DH_OK)
756		goto failed;
757
758	err = check_ownership(sdev, h);
759	if (err != SCSI_DH_OK)
760		goto clean_ctlr;
761
762	err = set_mode_select(sdev, h);
763	if (err != SCSI_DH_OK)
764		goto clean_ctlr;
765
766	sdev_printk(KERN_NOTICE, sdev,
767		    "%s: LUN %d (%s) (%s)\n",
768		    RDAC_NAME, h->lun, mode[(int)h->mode],
769		    lun_state[(int)h->lun_state]);
770
771	sdev->handler_data = h;
772	return SCSI_DH_OK;
773
774clean_ctlr:
775	spin_lock(&list_lock);
776	kref_put(&h->ctlr->kref, release_controller);
777	spin_unlock(&list_lock);
778
779failed:
780	kfree(h);
781	return err;
782}
783
784static void rdac_bus_detach( struct scsi_device *sdev )
785{
786	struct rdac_dh_data *h = sdev->handler_data;
787
788	if (h->ctlr && h->ctlr->ms_queued)
789		flush_workqueue(kmpath_rdacd);
790
791	spin_lock(&list_lock);
792	if (h->ctlr) {
793		list_del_rcu(&h->node);
794		kref_put(&h->ctlr->kref, release_controller);
795	}
796	spin_unlock(&list_lock);
797	sdev->handler_data = NULL;
798	synchronize_rcu();
799	kfree(h);
800}
801
802static struct scsi_device_handler rdac_dh = {
803	.name = RDAC_NAME,
804	.module = THIS_MODULE,
805	.prep_fn = rdac_prep_fn,
806	.check_sense = rdac_check_sense,
807	.attach = rdac_bus_attach,
808	.detach = rdac_bus_detach,
809	.activate = rdac_activate,
810};
811
812static int __init rdac_init(void)
813{
814	int r;
815
816	r = scsi_register_device_handler(&rdac_dh);
817	if (r != 0) {
818		printk(KERN_ERR "Failed to register scsi device handler.");
819		goto done;
820	}
821
822	/*
823	 * Create workqueue to handle mode selects for rdac
824	 */
825	kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
826	if (!kmpath_rdacd) {
827		scsi_unregister_device_handler(&rdac_dh);
828		printk(KERN_ERR "kmpath_rdacd creation failed.\n");
829
830		r = -EINVAL;
831	}
832done:
833	return r;
834}
835
836static void __exit rdac_exit(void)
837{
838	destroy_workqueue(kmpath_rdacd);
839	scsi_unregister_device_handler(&rdac_dh);
840}
841
842module_init(rdac_init);
843module_exit(rdac_exit);
844
845MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
846MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
847MODULE_VERSION("01.00.0000.0000");
848MODULE_LICENSE("GPL");
849