1 /*
2  * Engenio/LSI 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 
28 #define RDAC_NAME "rdac"
29 #define RDAC_RETRY_COUNT 5
30 
31 /*
32  * LSI mode page stuff
33  *
34  * These struct definitions and the forming of the
35  * mode page were taken from the LSI RDAC 2.4 GPL'd
36  * driver, and then converted to Linux conventions.
37  */
38 #define RDAC_QUIESCENCE_TIME 20;
39 /*
40  * Page Codes
41  */
42 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
43 
44 /*
45  * Controller modes definitions
46  */
47 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS	0x02
48 
49 /*
50  * RDAC Options field
51  */
52 #define RDAC_FORCED_QUIESENCE 0x02
53 
54 #define RDAC_TIMEOUT	(60 * HZ)
55 #define RDAC_RETRIES	3
56 
57 struct rdac_mode_6_hdr {
58 	u8	data_len;
59 	u8	medium_type;
60 	u8	device_params;
61 	u8	block_desc_len;
62 };
63 
64 struct rdac_mode_10_hdr {
65 	u16	data_len;
66 	u8	medium_type;
67 	u8	device_params;
68 	u16	reserved;
69 	u16	block_desc_len;
70 };
71 
72 struct rdac_mode_common {
73 	u8	controller_serial[16];
74 	u8	alt_controller_serial[16];
75 	u8	rdac_mode[2];
76 	u8	alt_rdac_mode[2];
77 	u8	quiescence_timeout;
78 	u8	rdac_options;
79 };
80 
81 struct rdac_pg_legacy {
82 	struct rdac_mode_6_hdr hdr;
83 	u8	page_code;
84 	u8	page_len;
85 	struct rdac_mode_common common;
86 #define MODE6_MAX_LUN	32
87 	u8	lun_table[MODE6_MAX_LUN];
88 	u8	reserved2[32];
89 	u8	reserved3;
90 	u8	reserved4;
91 };
92 
93 struct rdac_pg_expanded {
94 	struct rdac_mode_10_hdr hdr;
95 	u8	page_code;
96 	u8	subpage_code;
97 	u8	page_len[2];
98 	struct rdac_mode_common common;
99 	u8	lun_table[256];
100 	u8	reserved3;
101 	u8	reserved4;
102 };
103 
104 struct c9_inquiry {
105 	u8	peripheral_info;
106 	u8	page_code;	/* 0xC9 */
107 	u8	reserved1;
108 	u8	page_len;
109 	u8	page_id[4];	/* "vace" */
110 	u8	avte_cvp;
111 	u8	path_prio;
112 	u8	reserved2[38];
113 };
114 
115 #define SUBSYS_ID_LEN	16
116 #define SLOT_ID_LEN	2
117 #define ARRAY_LABEL_LEN	31
118 
119 struct c4_inquiry {
120 	u8	peripheral_info;
121 	u8	page_code;	/* 0xC4 */
122 	u8	reserved1;
123 	u8	page_len;
124 	u8	page_id[4];	/* "subs" */
125 	u8	subsys_id[SUBSYS_ID_LEN];
126 	u8	revision[4];
127 	u8	slot_id[SLOT_ID_LEN];
128 	u8	reserved[2];
129 };
130 
131 struct rdac_controller {
132 	u8			subsys_id[SUBSYS_ID_LEN];
133 	u8			slot_id[SLOT_ID_LEN];
134 	int			use_ms10;
135 	struct kref		kref;
136 	struct list_head	node; /* list of all controllers */
137 	union			{
138 		struct rdac_pg_legacy legacy;
139 		struct rdac_pg_expanded expanded;
140 	} mode_select;
141 	u8	index;
142 	u8	array_name[ARRAY_LABEL_LEN];
143 	spinlock_t		ms_lock;
144 	int			ms_queued;
145 	struct work_struct	ms_work;
146 	struct scsi_device	*ms_sdev;
147 	struct list_head	ms_head;
148 };
149 
150 struct c8_inquiry {
151 	u8	peripheral_info;
152 	u8	page_code; /* 0xC8 */
153 	u8	reserved1;
154 	u8	page_len;
155 	u8	page_id[4]; /* "edid" */
156 	u8	reserved2[3];
157 	u8	vol_uniq_id_len;
158 	u8	vol_uniq_id[16];
159 	u8	vol_user_label_len;
160 	u8	vol_user_label[60];
161 	u8	array_uniq_id_len;
162 	u8	array_unique_id[16];
163 	u8	array_user_label_len;
164 	u8	array_user_label[60];
165 	u8	lun[8];
166 };
167 
168 struct c2_inquiry {
169 	u8	peripheral_info;
170 	u8	page_code;	/* 0xC2 */
171 	u8	reserved1;
172 	u8	page_len;
173 	u8	page_id[4];	/* "swr4" */
174 	u8	sw_version[3];
175 	u8	sw_date[3];
176 	u8	features_enabled;
177 	u8	max_lun_supported;
178 	u8	partitions[239]; /* Total allocation length should be 0xFF */
179 };
180 
181 struct rdac_dh_data {
182 	struct rdac_controller	*ctlr;
183 #define UNINITIALIZED_LUN	(1 << 8)
184 	unsigned		lun;
185 
186 #define RDAC_MODE		0
187 #define RDAC_MODE_AVT		1
188 #define RDAC_MODE_IOSHIP	2
189 	unsigned char		mode;
190 
191 #define RDAC_STATE_ACTIVE	0
192 #define RDAC_STATE_PASSIVE	1
193 	unsigned char		state;
194 
195 #define RDAC_LUN_UNOWNED	0
196 #define RDAC_LUN_OWNED		1
197 	char			lun_state;
198 
199 #define RDAC_PREFERRED		0
200 #define RDAC_NON_PREFERRED	1
201 	char			preferred;
202 
203 	unsigned char		sense[SCSI_SENSE_BUFFERSIZE];
204 	union			{
205 		struct c2_inquiry c2;
206 		struct c4_inquiry c4;
207 		struct c8_inquiry c8;
208 		struct c9_inquiry c9;
209 	} inq;
210 };
211 
212 static const char *mode[] = {
213 	"RDAC",
214 	"AVT",
215 	"IOSHIP",
216 };
217 static const char *lun_state[] =
218 {
219 	"unowned",
220 	"owned",
221 };
222 
223 struct rdac_queue_data {
224 	struct list_head	entry;
225 	struct rdac_dh_data	*h;
226 	activate_complete	callback_fn;
227 	void			*callback_data;
228 };
229 
230 static LIST_HEAD(ctlr_list);
231 static DEFINE_SPINLOCK(list_lock);
232 static struct workqueue_struct *kmpath_rdacd;
233 static void send_mode_select(struct work_struct *work);
234 
235 /*
236  * module parameter to enable rdac debug logging.
237  * 2 bits for each type of logging, only two types defined for now
238  * Can be enhanced if required at later point
239  */
240 static int rdac_logging = 1;
241 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
242 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
243 		"Default is 1 - failover logging enabled, "
244 		"set it to 0xF to enable all the logs");
245 
246 #define RDAC_LOG_FAILOVER	0
247 #define RDAC_LOG_SENSE		2
248 
249 #define RDAC_LOG_BITS		2
250 
251 #define RDAC_LOG_LEVEL(SHIFT)  \
252 	((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
253 
254 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
255 do { \
256 	if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
257 		sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
258 } while (0);
259 
260 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
261 {
262 	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
263 	BUG_ON(scsi_dh_data == NULL);
264 	return ((struct rdac_dh_data *) scsi_dh_data->buf);
265 }
266 
267 static struct request *get_rdac_req(struct scsi_device *sdev,
268 			void *buffer, unsigned buflen, int rw)
269 {
270 	struct request *rq;
271 	struct request_queue *q = sdev->request_queue;
272 
273 	rq = blk_get_request(q, rw, GFP_NOIO);
274 
275 	if (!rq) {
276 		sdev_printk(KERN_INFO, sdev,
277 				"get_rdac_req: blk_get_request failed.\n");
278 		return NULL;
279 	}
280 
281 	if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
282 		blk_put_request(rq);
283 		sdev_printk(KERN_INFO, sdev,
284 				"get_rdac_req: blk_rq_map_kern failed.\n");
285 		return NULL;
286 	}
287 
288 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
289 	rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
290 			 REQ_FAILFAST_DRIVER;
291 	rq->retries = RDAC_RETRIES;
292 	rq->timeout = RDAC_TIMEOUT;
293 
294 	return rq;
295 }
296 
297 static struct request *rdac_failover_get(struct scsi_device *sdev,
298 			struct rdac_dh_data *h, struct list_head *list)
299 {
300 	struct request *rq;
301 	struct rdac_mode_common *common;
302 	unsigned data_size;
303 	struct rdac_queue_data *qdata;
304 	u8 *lun_table;
305 
306 	if (h->ctlr->use_ms10) {
307 		struct rdac_pg_expanded *rdac_pg;
308 
309 		data_size = sizeof(struct rdac_pg_expanded);
310 		rdac_pg = &h->ctlr->mode_select.expanded;
311 		memset(rdac_pg, 0, data_size);
312 		common = &rdac_pg->common;
313 		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
314 		rdac_pg->subpage_code = 0x1;
315 		rdac_pg->page_len[0] = 0x01;
316 		rdac_pg->page_len[1] = 0x28;
317 		lun_table = rdac_pg->lun_table;
318 	} else {
319 		struct rdac_pg_legacy *rdac_pg;
320 
321 		data_size = sizeof(struct rdac_pg_legacy);
322 		rdac_pg = &h->ctlr->mode_select.legacy;
323 		memset(rdac_pg, 0, data_size);
324 		common = &rdac_pg->common;
325 		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
326 		rdac_pg->page_len = 0x68;
327 		lun_table = rdac_pg->lun_table;
328 	}
329 	common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
330 	common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
331 	common->rdac_options = RDAC_FORCED_QUIESENCE;
332 
333 	list_for_each_entry(qdata, list, entry) {
334 		lun_table[qdata->h->lun] = 0x81;
335 	}
336 
337 	/* get request for block layer packet command */
338 	rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
339 	if (!rq)
340 		return NULL;
341 
342 	/* Prepare the command. */
343 	if (h->ctlr->use_ms10) {
344 		rq->cmd[0] = MODE_SELECT_10;
345 		rq->cmd[7] = data_size >> 8;
346 		rq->cmd[8] = data_size & 0xff;
347 	} else {
348 		rq->cmd[0] = MODE_SELECT;
349 		rq->cmd[4] = data_size;
350 	}
351 	rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
352 
353 	rq->sense = h->sense;
354 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
355 	rq->sense_len = 0;
356 
357 	return rq;
358 }
359 
360 static void release_controller(struct kref *kref)
361 {
362 	struct rdac_controller *ctlr;
363 	ctlr = container_of(kref, struct rdac_controller, kref);
364 
365 	flush_workqueue(kmpath_rdacd);
366 	spin_lock(&list_lock);
367 	list_del(&ctlr->node);
368 	spin_unlock(&list_lock);
369 	kfree(ctlr);
370 }
371 
372 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id,
373 						char *array_name)
374 {
375 	struct rdac_controller *ctlr, *tmp;
376 
377 	spin_lock(&list_lock);
378 
379 	list_for_each_entry(tmp, &ctlr_list, node) {
380 		if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) &&
381 			  (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
382 			kref_get(&tmp->kref);
383 			spin_unlock(&list_lock);
384 			return tmp;
385 		}
386 	}
387 	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
388 	if (!ctlr)
389 		goto done;
390 
391 	/* initialize fields of controller */
392 	memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
393 	memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
394 	memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
395 
396 	/* update the controller index */
397 	if (slot_id[1] == 0x31)
398 		ctlr->index = 0;
399 	else
400 		ctlr->index = 1;
401 
402 	kref_init(&ctlr->kref);
403 	ctlr->use_ms10 = -1;
404 	ctlr->ms_queued = 0;
405 	ctlr->ms_sdev = NULL;
406 	spin_lock_init(&ctlr->ms_lock);
407 	INIT_WORK(&ctlr->ms_work, send_mode_select);
408 	INIT_LIST_HEAD(&ctlr->ms_head);
409 	list_add(&ctlr->node, &ctlr_list);
410 done:
411 	spin_unlock(&list_lock);
412 	return ctlr;
413 }
414 
415 static int submit_inquiry(struct scsi_device *sdev, int page_code,
416 			  unsigned int len, struct rdac_dh_data *h)
417 {
418 	struct request *rq;
419 	struct request_queue *q = sdev->request_queue;
420 	int err = SCSI_DH_RES_TEMP_UNAVAIL;
421 
422 	rq = get_rdac_req(sdev, &h->inq, len, READ);
423 	if (!rq)
424 		goto done;
425 
426 	/* Prepare the command. */
427 	rq->cmd[0] = INQUIRY;
428 	rq->cmd[1] = 1;
429 	rq->cmd[2] = page_code;
430 	rq->cmd[4] = len;
431 	rq->cmd_len = COMMAND_SIZE(INQUIRY);
432 
433 	rq->sense = h->sense;
434 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
435 	rq->sense_len = 0;
436 
437 	err = blk_execute_rq(q, NULL, rq, 1);
438 	if (err == -EIO)
439 		err = SCSI_DH_IO;
440 
441 	blk_put_request(rq);
442 done:
443 	return err;
444 }
445 
446 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
447 			char *array_name)
448 {
449 	int err, i;
450 	struct c8_inquiry *inqp;
451 
452 	err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
453 	if (err == SCSI_DH_OK) {
454 		inqp = &h->inq.c8;
455 		if (inqp->page_code != 0xc8)
456 			return SCSI_DH_NOSYS;
457 		if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
458 		    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
459 			return SCSI_DH_NOSYS;
460 		h->lun = inqp->lun[7]; /* Uses only the last byte */
461 
462 		for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
463 			*(array_name+i) = inqp->array_user_label[(2*i)+1];
464 
465 		*(array_name+ARRAY_LABEL_LEN-1) = '\0';
466 	}
467 	return err;
468 }
469 
470 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
471 {
472 	int err;
473 	struct c9_inquiry *inqp;
474 
475 	h->state = RDAC_STATE_ACTIVE;
476 	err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
477 	if (err == SCSI_DH_OK) {
478 		inqp = &h->inq.c9;
479 		/* detect the operating mode */
480 		if ((inqp->avte_cvp >> 5) & 0x1)
481 			h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
482 		else if (inqp->avte_cvp >> 7)
483 			h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
484 		else
485 			h->mode = RDAC_MODE; /* LUN in RDAC mode */
486 
487 		/* Update ownership */
488 		if (inqp->avte_cvp & 0x1)
489 			h->lun_state = RDAC_LUN_OWNED;
490 		else {
491 			h->lun_state = RDAC_LUN_UNOWNED;
492 			if (h->mode == RDAC_MODE)
493 				h->state = RDAC_STATE_PASSIVE;
494 		}
495 
496 		/* Update path prio*/
497 		if (inqp->path_prio & 0x1)
498 			h->preferred = RDAC_PREFERRED;
499 		else
500 			h->preferred = RDAC_NON_PREFERRED;
501 	}
502 
503 	return err;
504 }
505 
506 static int initialize_controller(struct scsi_device *sdev,
507 				 struct rdac_dh_data *h, char *array_name)
508 {
509 	int err;
510 	struct c4_inquiry *inqp;
511 
512 	err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
513 	if (err == SCSI_DH_OK) {
514 		inqp = &h->inq.c4;
515 		h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id,
516 					array_name);
517 		if (!h->ctlr)
518 			err = SCSI_DH_RES_TEMP_UNAVAIL;
519 	}
520 	return err;
521 }
522 
523 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
524 {
525 	int err;
526 	struct c2_inquiry *inqp;
527 
528 	err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
529 	if (err == SCSI_DH_OK) {
530 		inqp = &h->inq.c2;
531 		/*
532 		 * If more than MODE6_MAX_LUN luns are supported, use
533 		 * mode select 10
534 		 */
535 		if (inqp->max_lun_supported >= MODE6_MAX_LUN)
536 			h->ctlr->use_ms10 = 1;
537 		else
538 			h->ctlr->use_ms10 = 0;
539 	}
540 	return err;
541 }
542 
543 static int mode_select_handle_sense(struct scsi_device *sdev,
544 					unsigned char *sensebuf)
545 {
546 	struct scsi_sense_hdr sense_hdr;
547 	int err = SCSI_DH_IO, ret;
548 	struct rdac_dh_data *h = get_rdac_data(sdev);
549 
550 	ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
551 	if (!ret)
552 		goto done;
553 
554 	switch (sense_hdr.sense_key) {
555 	case NO_SENSE:
556 	case ABORTED_COMMAND:
557 	case UNIT_ATTENTION:
558 		err = SCSI_DH_RETRY;
559 		break;
560 	case NOT_READY:
561 		if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
562 			/* LUN Not Ready and is in the Process of Becoming
563 			 * Ready
564 			 */
565 			err = SCSI_DH_RETRY;
566 		break;
567 	case ILLEGAL_REQUEST:
568 		if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
569 			/*
570 			 * Command Lock contention
571 			 */
572 			err = SCSI_DH_RETRY;
573 		break;
574 	default:
575 		break;
576 	}
577 
578 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
579 		"MODE_SELECT returned with sense %02x/%02x/%02x",
580 		(char *) h->ctlr->array_name, h->ctlr->index,
581 		sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
582 
583 done:
584 	return err;
585 }
586 
587 static void send_mode_select(struct work_struct *work)
588 {
589 	struct rdac_controller *ctlr =
590 		container_of(work, struct rdac_controller, ms_work);
591 	struct request *rq;
592 	struct scsi_device *sdev = ctlr->ms_sdev;
593 	struct rdac_dh_data *h = get_rdac_data(sdev);
594 	struct request_queue *q = sdev->request_queue;
595 	int err, retry_cnt = RDAC_RETRY_COUNT;
596 	struct rdac_queue_data *tmp, *qdata;
597 	LIST_HEAD(list);
598 
599 	spin_lock(&ctlr->ms_lock);
600 	list_splice_init(&ctlr->ms_head, &list);
601 	ctlr->ms_queued = 0;
602 	ctlr->ms_sdev = NULL;
603 	spin_unlock(&ctlr->ms_lock);
604 
605 retry:
606 	err = SCSI_DH_RES_TEMP_UNAVAIL;
607 	rq = rdac_failover_get(sdev, h, &list);
608 	if (!rq)
609 		goto done;
610 
611 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
612 		"%s MODE_SELECT command",
613 		(char *) h->ctlr->array_name, h->ctlr->index,
614 		(retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
615 
616 	err = blk_execute_rq(q, NULL, rq, 1);
617 	blk_put_request(rq);
618 	if (err != SCSI_DH_OK) {
619 		err = mode_select_handle_sense(sdev, h->sense);
620 		if (err == SCSI_DH_RETRY && retry_cnt--)
621 			goto retry;
622 	}
623 	if (err == SCSI_DH_OK) {
624 		h->state = RDAC_STATE_ACTIVE;
625 		RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
626 				"MODE_SELECT completed",
627 				(char *) h->ctlr->array_name, h->ctlr->index);
628 	}
629 
630 done:
631 	list_for_each_entry_safe(qdata, tmp, &list, entry) {
632 		list_del(&qdata->entry);
633 		if (err == SCSI_DH_OK)
634 			qdata->h->state = RDAC_STATE_ACTIVE;
635 		if (qdata->callback_fn)
636 			qdata->callback_fn(qdata->callback_data, err);
637 		kfree(qdata);
638 	}
639 	return;
640 }
641 
642 static int queue_mode_select(struct scsi_device *sdev,
643 				activate_complete fn, void *data)
644 {
645 	struct rdac_queue_data *qdata;
646 	struct rdac_controller *ctlr;
647 
648 	qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
649 	if (!qdata)
650 		return SCSI_DH_RETRY;
651 
652 	qdata->h = get_rdac_data(sdev);
653 	qdata->callback_fn = fn;
654 	qdata->callback_data = data;
655 
656 	ctlr = qdata->h->ctlr;
657 	spin_lock(&ctlr->ms_lock);
658 	list_add_tail(&qdata->entry, &ctlr->ms_head);
659 	if (!ctlr->ms_queued) {
660 		ctlr->ms_queued = 1;
661 		ctlr->ms_sdev = sdev;
662 		queue_work(kmpath_rdacd, &ctlr->ms_work);
663 	}
664 	spin_unlock(&ctlr->ms_lock);
665 	return SCSI_DH_OK;
666 }
667 
668 static int rdac_activate(struct scsi_device *sdev,
669 			activate_complete fn, void *data)
670 {
671 	struct rdac_dh_data *h = get_rdac_data(sdev);
672 	int err = SCSI_DH_OK;
673 	int act = 0;
674 
675 	err = check_ownership(sdev, h);
676 	if (err != SCSI_DH_OK)
677 		goto done;
678 
679 	switch (h->mode) {
680 	case RDAC_MODE:
681 		if (h->lun_state == RDAC_LUN_UNOWNED)
682 			act = 1;
683 		break;
684 	case RDAC_MODE_IOSHIP:
685 		if ((h->lun_state == RDAC_LUN_UNOWNED) &&
686 		    (h->preferred == RDAC_PREFERRED))
687 			act = 1;
688 		break;
689 	default:
690 		break;
691 	}
692 
693 	if (act) {
694 		err = queue_mode_select(sdev, fn, data);
695 		if (err == SCSI_DH_OK)
696 			return 0;
697 	}
698 done:
699 	if (fn)
700 		fn(data, err);
701 	return 0;
702 }
703 
704 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
705 {
706 	struct rdac_dh_data *h = get_rdac_data(sdev);
707 	int ret = BLKPREP_OK;
708 
709 	if (h->state != RDAC_STATE_ACTIVE) {
710 		ret = BLKPREP_KILL;
711 		req->cmd_flags |= REQ_QUIET;
712 	}
713 	return ret;
714 
715 }
716 
717 static int rdac_check_sense(struct scsi_device *sdev,
718 				struct scsi_sense_hdr *sense_hdr)
719 {
720 	struct rdac_dh_data *h = get_rdac_data(sdev);
721 
722 	RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
723 			"I/O returned with sense %02x/%02x/%02x",
724 			(char *) h->ctlr->array_name, h->ctlr->index,
725 			sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
726 
727 	switch (sense_hdr->sense_key) {
728 	case NOT_READY:
729 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
730 			/* LUN Not Ready - Logical Unit Not Ready and is in
731 			* the process of becoming ready
732 			* Just retry.
733 			*/
734 			return ADD_TO_MLQUEUE;
735 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
736 			/* LUN Not Ready - Storage firmware incompatible
737 			 * Manual code synchonisation required.
738 			 *
739 			 * Nothing we can do here. Try to bypass the path.
740 			 */
741 			return SUCCESS;
742 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
743 			/* LUN Not Ready - Quiescense in progress
744 			 *
745 			 * Just retry and wait.
746 			 */
747 			return ADD_TO_MLQUEUE;
748 		if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
749 			/* LUN Not Ready - Quiescense in progress
750 			 * or has been achieved
751 			 * Just retry.
752 			 */
753 			return ADD_TO_MLQUEUE;
754 		break;
755 	case ILLEGAL_REQUEST:
756 		if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
757 			/* Invalid Request - Current Logical Unit Ownership.
758 			 * Controller is not the current owner of the LUN,
759 			 * Fail the path, so that the other path be used.
760 			 */
761 			h->state = RDAC_STATE_PASSIVE;
762 			return SUCCESS;
763 		}
764 		break;
765 	case UNIT_ATTENTION:
766 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
767 			/*
768 			 * Power On, Reset, or Bus Device Reset, just retry.
769 			 */
770 			return ADD_TO_MLQUEUE;
771 		if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
772 			/*
773 			 * Quiescence in progress , just retry.
774 			 */
775 			return ADD_TO_MLQUEUE;
776 		break;
777 	}
778 	/* success just means we do not care what scsi-ml does */
779 	return SCSI_RETURN_NOT_HANDLED;
780 }
781 
782 static const struct scsi_dh_devlist rdac_dev_list[] = {
783 	{"IBM", "1722"},
784 	{"IBM", "1724"},
785 	{"IBM", "1726"},
786 	{"IBM", "1742"},
787 	{"IBM", "1745"},
788 	{"IBM", "1746"},
789 	{"IBM", "1814"},
790 	{"IBM", "1815"},
791 	{"IBM", "1818"},
792 	{"IBM", "3526"},
793 	{"SGI", "TP9400"},
794 	{"SGI", "TP9500"},
795 	{"SGI", "IS"},
796 	{"STK", "OPENstorage D280"},
797 	{"SUN", "CSM200_R"},
798 	{"SUN", "LCSM100_I"},
799 	{"SUN", "LCSM100_S"},
800 	{"SUN", "LCSM100_E"},
801 	{"SUN", "LCSM100_F"},
802 	{"DELL", "MD3000"},
803 	{"DELL", "MD3000i"},
804 	{"DELL", "MD32xx"},
805 	{"DELL", "MD32xxi"},
806 	{"DELL", "MD36xxi"},
807 	{"DELL", "MD36xxf"},
808 	{"LSI", "INF-01-00"},
809 	{"ENGENIO", "INF-01-00"},
810 	{"STK", "FLEXLINE 380"},
811 	{"SUN", "CSM100_R_FC"},
812 	{"SUN", "STK6580_6780"},
813 	{"SUN", "SUN_6180"},
814 	{NULL, NULL},
815 };
816 
817 static int rdac_bus_attach(struct scsi_device *sdev);
818 static void rdac_bus_detach(struct scsi_device *sdev);
819 
820 static struct scsi_device_handler rdac_dh = {
821 	.name = RDAC_NAME,
822 	.module = THIS_MODULE,
823 	.devlist = rdac_dev_list,
824 	.prep_fn = rdac_prep_fn,
825 	.check_sense = rdac_check_sense,
826 	.attach = rdac_bus_attach,
827 	.detach = rdac_bus_detach,
828 	.activate = rdac_activate,
829 };
830 
831 static int rdac_bus_attach(struct scsi_device *sdev)
832 {
833 	struct scsi_dh_data *scsi_dh_data;
834 	struct rdac_dh_data *h;
835 	unsigned long flags;
836 	int err;
837 	char array_name[ARRAY_LABEL_LEN];
838 
839 	scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
840 			       + sizeof(*h) , GFP_KERNEL);
841 	if (!scsi_dh_data) {
842 		sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
843 			    RDAC_NAME);
844 		return 0;
845 	}
846 
847 	scsi_dh_data->scsi_dh = &rdac_dh;
848 	h = (struct rdac_dh_data *) scsi_dh_data->buf;
849 	h->lun = UNINITIALIZED_LUN;
850 	h->state = RDAC_STATE_ACTIVE;
851 
852 	err = get_lun_info(sdev, h, array_name);
853 	if (err != SCSI_DH_OK)
854 		goto failed;
855 
856 	err = initialize_controller(sdev, h, array_name);
857 	if (err != SCSI_DH_OK)
858 		goto failed;
859 
860 	err = check_ownership(sdev, h);
861 	if (err != SCSI_DH_OK)
862 		goto clean_ctlr;
863 
864 	err = set_mode_select(sdev, h);
865 	if (err != SCSI_DH_OK)
866 		goto clean_ctlr;
867 
868 	if (!try_module_get(THIS_MODULE))
869 		goto clean_ctlr;
870 
871 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
872 	sdev->scsi_dh_data = scsi_dh_data;
873 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
874 
875 	sdev_printk(KERN_NOTICE, sdev,
876 		    "%s: LUN %d (%s) (%s)\n",
877 		    RDAC_NAME, h->lun, mode[(int)h->mode],
878 		    lun_state[(int)h->lun_state]);
879 
880 	return 0;
881 
882 clean_ctlr:
883 	kref_put(&h->ctlr->kref, release_controller);
884 
885 failed:
886 	kfree(scsi_dh_data);
887 	sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
888 		    RDAC_NAME);
889 	return -EINVAL;
890 }
891 
892 static void rdac_bus_detach( struct scsi_device *sdev )
893 {
894 	struct scsi_dh_data *scsi_dh_data;
895 	struct rdac_dh_data *h;
896 	unsigned long flags;
897 
898 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
899 	scsi_dh_data = sdev->scsi_dh_data;
900 	sdev->scsi_dh_data = NULL;
901 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
902 
903 	h = (struct rdac_dh_data *) scsi_dh_data->buf;
904 	if (h->ctlr)
905 		kref_put(&h->ctlr->kref, release_controller);
906 	kfree(scsi_dh_data);
907 	module_put(THIS_MODULE);
908 	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
909 }
910 
911 
912 
913 static int __init rdac_init(void)
914 {
915 	int r;
916 
917 	r = scsi_register_device_handler(&rdac_dh);
918 	if (r != 0) {
919 		printk(KERN_ERR "Failed to register scsi device handler.");
920 		goto done;
921 	}
922 
923 	/*
924 	 * Create workqueue to handle mode selects for rdac
925 	 */
926 	kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
927 	if (!kmpath_rdacd) {
928 		scsi_unregister_device_handler(&rdac_dh);
929 		printk(KERN_ERR "kmpath_rdacd creation failed.\n");
930 	}
931 done:
932 	return r;
933 }
934 
935 static void __exit rdac_exit(void)
936 {
937 	destroy_workqueue(kmpath_rdacd);
938 	scsi_unregister_device_handler(&rdac_dh);
939 }
940 
941 module_init(rdac_init);
942 module_exit(rdac_exit);
943 
944 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver");
945 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
946 MODULE_VERSION("01.00.0000.0000");
947 MODULE_LICENSE("GPL");
948