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 
58 struct rdac_mode_6_hdr {
59 	u8	data_len;
60 	u8	medium_type;
61 	u8	device_params;
62 	u8	block_desc_len;
63 };
64 
65 struct 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 
73 struct 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 
82 struct 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 
94 struct 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 
105 struct 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 
120 struct 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
133 struct 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 
151 struct 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 };
169 
170 struct c2_inquiry {
171 	u8	peripheral_info;
172 	u8	page_code;	/* 0xC2 */
173 	u8	reserved1;
174 	u8	page_len;
175 	u8	page_id[4];	/* "swr4" */
176 	u8	sw_version[3];
177 	u8	sw_date[3];
178 	u8	features_enabled;
179 	u8	max_lun_supported;
180 	u8	partitions[239]; /* Total allocation length should be 0xFF */
181 };
182 
183 struct rdac_dh_data {
184 	struct scsi_dh_data	dh_data;
185 	struct rdac_controller	*ctlr;
186 #define UNINITIALIZED_LUN	(1 << 8)
187 	unsigned		lun;
188 
189 #define RDAC_MODE		0
190 #define RDAC_MODE_AVT		1
191 #define RDAC_MODE_IOSHIP	2
192 	unsigned char		mode;
193 
194 #define RDAC_STATE_ACTIVE	0
195 #define RDAC_STATE_PASSIVE	1
196 	unsigned char		state;
197 
198 #define RDAC_LUN_UNOWNED	0
199 #define RDAC_LUN_OWNED		1
200 	char			lun_state;
201 
202 #define RDAC_PREFERRED		0
203 #define RDAC_NON_PREFERRED	1
204 	char			preferred;
205 
206 	unsigned char		sense[SCSI_SENSE_BUFFERSIZE];
207 	union			{
208 		struct c2_inquiry c2;
209 		struct c4_inquiry c4;
210 		struct c8_inquiry c8;
211 		struct c9_inquiry c9;
212 	} inq;
213 };
214 
215 static const char *mode[] = {
216 	"RDAC",
217 	"AVT",
218 	"IOSHIP",
219 };
220 static const char *lun_state[] =
221 {
222 	"unowned",
223 	"owned",
224 };
225 
226 struct rdac_queue_data {
227 	struct list_head	entry;
228 	struct rdac_dh_data	*h;
229 	activate_complete	callback_fn;
230 	void			*callback_data;
231 };
232 
233 static LIST_HEAD(ctlr_list);
234 static DEFINE_SPINLOCK(list_lock);
235 static struct workqueue_struct *kmpath_rdacd;
236 static void send_mode_select(struct work_struct *work);
237 
238 /*
239  * module parameter to enable rdac debug logging.
240  * 2 bits for each type of logging, only two types defined for now
241  * Can be enhanced if required at later point
242  */
243 static int rdac_logging = 1;
244 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
245 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
246 		"Default is 1 - failover logging enabled, "
247 		"set it to 0xF to enable all the logs");
248 
249 #define RDAC_LOG_FAILOVER	0
250 #define RDAC_LOG_SENSE		2
251 
252 #define RDAC_LOG_BITS		2
253 
254 #define RDAC_LOG_LEVEL(SHIFT)  \
255 	((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
256 
257 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
258 do { \
259 	if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
260 		sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
261 } while (0);
262 
263 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
264 {
265 	return container_of(sdev->scsi_dh_data, struct rdac_dh_data, dh_data);
266 }
267 
268 static struct request *get_rdac_req(struct scsi_device *sdev,
269 			void *buffer, unsigned buflen, int rw)
270 {
271 	struct request *rq;
272 	struct request_queue *q = sdev->request_queue;
273 
274 	rq = blk_get_request(q, rw, GFP_NOIO);
275 
276 	if (IS_ERR(rq)) {
277 		sdev_printk(KERN_INFO, sdev,
278 				"get_rdac_req: blk_get_request failed.\n");
279 		return NULL;
280 	}
281 	blk_rq_set_block_pc(rq);
282 
283 	if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
284 		blk_put_request(rq);
285 		sdev_printk(KERN_INFO, sdev,
286 				"get_rdac_req: blk_rq_map_kern failed.\n");
287 		return NULL;
288 	}
289 
290 	rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
291 			 REQ_FAILFAST_DRIVER;
292 	rq->retries = RDAC_RETRIES;
293 	rq->timeout = RDAC_TIMEOUT;
294 
295 	return rq;
296 }
297 
298 static struct request *rdac_failover_get(struct scsi_device *sdev,
299 			struct rdac_dh_data *h, struct list_head *list)
300 {
301 	struct request *rq;
302 	struct rdac_mode_common *common;
303 	unsigned data_size;
304 	struct rdac_queue_data *qdata;
305 	u8 *lun_table;
306 
307 	if (h->ctlr->use_ms10) {
308 		struct rdac_pg_expanded *rdac_pg;
309 
310 		data_size = sizeof(struct rdac_pg_expanded);
311 		rdac_pg = &h->ctlr->mode_select.expanded;
312 		memset(rdac_pg, 0, data_size);
313 		common = &rdac_pg->common;
314 		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
315 		rdac_pg->subpage_code = 0x1;
316 		rdac_pg->page_len[0] = 0x01;
317 		rdac_pg->page_len[1] = 0x28;
318 		lun_table = rdac_pg->lun_table;
319 	} else {
320 		struct rdac_pg_legacy *rdac_pg;
321 
322 		data_size = sizeof(struct rdac_pg_legacy);
323 		rdac_pg = &h->ctlr->mode_select.legacy;
324 		memset(rdac_pg, 0, data_size);
325 		common = &rdac_pg->common;
326 		rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
327 		rdac_pg->page_len = 0x68;
328 		lun_table = rdac_pg->lun_table;
329 	}
330 	common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
331 	common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
332 	common->rdac_options = RDAC_FORCED_QUIESENCE;
333 
334 	list_for_each_entry(qdata, list, entry) {
335 		lun_table[qdata->h->lun] = 0x81;
336 	}
337 
338 	/* get request for block layer packet command */
339 	rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
340 	if (!rq)
341 		return NULL;
342 
343 	/* Prepare the command. */
344 	if (h->ctlr->use_ms10) {
345 		rq->cmd[0] = MODE_SELECT_10;
346 		rq->cmd[7] = data_size >> 8;
347 		rq->cmd[8] = data_size & 0xff;
348 	} else {
349 		rq->cmd[0] = MODE_SELECT;
350 		rq->cmd[4] = data_size;
351 	}
352 	rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
353 
354 	rq->sense = h->sense;
355 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
356 	rq->sense_len = 0;
357 
358 	return rq;
359 }
360 
361 static void release_controller(struct kref *kref)
362 {
363 	struct rdac_controller *ctlr;
364 	ctlr = container_of(kref, struct rdac_controller, kref);
365 
366 	list_del(&ctlr->node);
367 	kfree(ctlr);
368 }
369 
370 static struct rdac_controller *get_controller(int index, char *array_name,
371 			u8 *array_id, struct scsi_device *sdev)
372 {
373 	struct rdac_controller *ctlr, *tmp;
374 
375 	list_for_each_entry(tmp, &ctlr_list, node) {
376 		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
377 			  (tmp->index == index) &&
378 			  (tmp->host == sdev->host)) {
379 			kref_get(&tmp->kref);
380 			return tmp;
381 		}
382 	}
383 	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
384 	if (!ctlr)
385 		return NULL;
386 
387 	/* initialize fields of controller */
388 	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
389 	ctlr->index = index;
390 	ctlr->host = sdev->host;
391 	memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
392 
393 	kref_init(&ctlr->kref);
394 	ctlr->use_ms10 = -1;
395 	ctlr->ms_queued = 0;
396 	ctlr->ms_sdev = NULL;
397 	spin_lock_init(&ctlr->ms_lock);
398 	INIT_WORK(&ctlr->ms_work, send_mode_select);
399 	INIT_LIST_HEAD(&ctlr->ms_head);
400 	list_add(&ctlr->node, &ctlr_list);
401 
402 	return ctlr;
403 }
404 
405 static int submit_inquiry(struct scsi_device *sdev, int page_code,
406 			  unsigned int len, struct rdac_dh_data *h)
407 {
408 	struct request *rq;
409 	struct request_queue *q = sdev->request_queue;
410 	int err = SCSI_DH_RES_TEMP_UNAVAIL;
411 
412 	rq = get_rdac_req(sdev, &h->inq, len, READ);
413 	if (!rq)
414 		goto done;
415 
416 	/* Prepare the command. */
417 	rq->cmd[0] = INQUIRY;
418 	rq->cmd[1] = 1;
419 	rq->cmd[2] = page_code;
420 	rq->cmd[4] = len;
421 	rq->cmd_len = COMMAND_SIZE(INQUIRY);
422 
423 	rq->sense = h->sense;
424 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
425 	rq->sense_len = 0;
426 
427 	err = blk_execute_rq(q, NULL, rq, 1);
428 	if (err == -EIO)
429 		err = SCSI_DH_IO;
430 
431 	blk_put_request(rq);
432 done:
433 	return err;
434 }
435 
436 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
437 			char *array_name, u8 *array_id)
438 {
439 	int err, i;
440 	struct c8_inquiry *inqp;
441 
442 	err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
443 	if (err == SCSI_DH_OK) {
444 		inqp = &h->inq.c8;
445 		if (inqp->page_code != 0xc8)
446 			return SCSI_DH_NOSYS;
447 		if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
448 		    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
449 			return SCSI_DH_NOSYS;
450 		h->lun = inqp->lun[7]; /* Uses only the last byte */
451 
452 		for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
453 			*(array_name+i) = inqp->array_user_label[(2*i)+1];
454 
455 		*(array_name+ARRAY_LABEL_LEN-1) = '\0';
456 		memset(array_id, 0, UNIQUE_ID_LEN);
457 		memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
458 	}
459 	return err;
460 }
461 
462 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
463 {
464 	int err;
465 	struct c9_inquiry *inqp;
466 
467 	h->state = RDAC_STATE_ACTIVE;
468 	err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
469 	if (err == SCSI_DH_OK) {
470 		inqp = &h->inq.c9;
471 		/* detect the operating mode */
472 		if ((inqp->avte_cvp >> 5) & 0x1)
473 			h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
474 		else if (inqp->avte_cvp >> 7)
475 			h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
476 		else
477 			h->mode = RDAC_MODE; /* LUN in RDAC mode */
478 
479 		/* Update ownership */
480 		if (inqp->avte_cvp & 0x1)
481 			h->lun_state = RDAC_LUN_OWNED;
482 		else {
483 			h->lun_state = RDAC_LUN_UNOWNED;
484 			if (h->mode == RDAC_MODE)
485 				h->state = RDAC_STATE_PASSIVE;
486 		}
487 
488 		/* Update path prio*/
489 		if (inqp->path_prio & 0x1)
490 			h->preferred = RDAC_PREFERRED;
491 		else
492 			h->preferred = RDAC_NON_PREFERRED;
493 	}
494 
495 	return err;
496 }
497 
498 static int initialize_controller(struct scsi_device *sdev,
499 		struct rdac_dh_data *h, char *array_name, u8 *array_id)
500 {
501 	int err, index;
502 	struct c4_inquiry *inqp;
503 
504 	err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
505 	if (err == SCSI_DH_OK) {
506 		inqp = &h->inq.c4;
507 		/* get the controller index */
508 		if (inqp->slot_id[1] == 0x31)
509 			index = 0;
510 		else
511 			index = 1;
512 
513 		spin_lock(&list_lock);
514 		h->ctlr = get_controller(index, array_name, array_id, sdev);
515 		if (!h->ctlr)
516 			err = SCSI_DH_RES_TEMP_UNAVAIL;
517 		spin_unlock(&list_lock);
518 	}
519 	return err;
520 }
521 
522 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
523 {
524 	int err;
525 	struct c2_inquiry *inqp;
526 
527 	err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
528 	if (err == SCSI_DH_OK) {
529 		inqp = &h->inq.c2;
530 		/*
531 		 * If more than MODE6_MAX_LUN luns are supported, use
532 		 * mode select 10
533 		 */
534 		if (inqp->max_lun_supported >= MODE6_MAX_LUN)
535 			h->ctlr->use_ms10 = 1;
536 		else
537 			h->ctlr->use_ms10 = 0;
538 	}
539 	return err;
540 }
541 
542 static int mode_select_handle_sense(struct scsi_device *sdev,
543 					unsigned char *sensebuf)
544 {
545 	struct scsi_sense_hdr sense_hdr;
546 	int err = SCSI_DH_IO, ret;
547 	struct rdac_dh_data *h = get_rdac_data(sdev);
548 
549 	ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
550 	if (!ret)
551 		goto done;
552 
553 	switch (sense_hdr.sense_key) {
554 	case NO_SENSE:
555 	case ABORTED_COMMAND:
556 	case UNIT_ATTENTION:
557 		err = SCSI_DH_RETRY;
558 		break;
559 	case NOT_READY:
560 		if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
561 			/* LUN Not Ready and is in the Process of Becoming
562 			 * Ready
563 			 */
564 			err = SCSI_DH_RETRY;
565 		break;
566 	case ILLEGAL_REQUEST:
567 		if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
568 			/*
569 			 * Command Lock contention
570 			 */
571 			err = SCSI_DH_RETRY;
572 		break;
573 	default:
574 		break;
575 	}
576 
577 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
578 		"MODE_SELECT returned with sense %02x/%02x/%02x",
579 		(char *) h->ctlr->array_name, h->ctlr->index,
580 		sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
581 
582 done:
583 	return err;
584 }
585 
586 static void send_mode_select(struct work_struct *work)
587 {
588 	struct rdac_controller *ctlr =
589 		container_of(work, struct rdac_controller, ms_work);
590 	struct request *rq;
591 	struct scsi_device *sdev = ctlr->ms_sdev;
592 	struct rdac_dh_data *h = get_rdac_data(sdev);
593 	struct request_queue *q = sdev->request_queue;
594 	int err, retry_cnt = RDAC_RETRY_COUNT;
595 	struct rdac_queue_data *tmp, *qdata;
596 	LIST_HEAD(list);
597 
598 	spin_lock(&ctlr->ms_lock);
599 	list_splice_init(&ctlr->ms_head, &list);
600 	ctlr->ms_queued = 0;
601 	ctlr->ms_sdev = NULL;
602 	spin_unlock(&ctlr->ms_lock);
603 
604 retry:
605 	err = SCSI_DH_RES_TEMP_UNAVAIL;
606 	rq = rdac_failover_get(sdev, h, &list);
607 	if (!rq)
608 		goto done;
609 
610 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
611 		"%s MODE_SELECT command",
612 		(char *) h->ctlr->array_name, h->ctlr->index,
613 		(retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
614 
615 	err = blk_execute_rq(q, NULL, rq, 1);
616 	blk_put_request(rq);
617 	if (err != SCSI_DH_OK) {
618 		err = mode_select_handle_sense(sdev, h->sense);
619 		if (err == SCSI_DH_RETRY && retry_cnt--)
620 			goto retry;
621 	}
622 	if (err == SCSI_DH_OK) {
623 		h->state = RDAC_STATE_ACTIVE;
624 		RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
625 				"MODE_SELECT completed",
626 				(char *) h->ctlr->array_name, h->ctlr->index);
627 	}
628 
629 done:
630 	list_for_each_entry_safe(qdata, tmp, &list, entry) {
631 		list_del(&qdata->entry);
632 		if (err == SCSI_DH_OK)
633 			qdata->h->state = RDAC_STATE_ACTIVE;
634 		if (qdata->callback_fn)
635 			qdata->callback_fn(qdata->callback_data, err);
636 		kfree(qdata);
637 	}
638 	return;
639 }
640 
641 static int queue_mode_select(struct scsi_device *sdev,
642 				activate_complete fn, void *data)
643 {
644 	struct rdac_queue_data *qdata;
645 	struct rdac_controller *ctlr;
646 
647 	qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
648 	if (!qdata)
649 		return SCSI_DH_RETRY;
650 
651 	qdata->h = get_rdac_data(sdev);
652 	qdata->callback_fn = fn;
653 	qdata->callback_data = data;
654 
655 	ctlr = qdata->h->ctlr;
656 	spin_lock(&ctlr->ms_lock);
657 	list_add_tail(&qdata->entry, &ctlr->ms_head);
658 	if (!ctlr->ms_queued) {
659 		ctlr->ms_queued = 1;
660 		ctlr->ms_sdev = sdev;
661 		queue_work(kmpath_rdacd, &ctlr->ms_work);
662 	}
663 	spin_unlock(&ctlr->ms_lock);
664 	return SCSI_DH_OK;
665 }
666 
667 static int rdac_activate(struct scsi_device *sdev,
668 			activate_complete fn, void *data)
669 {
670 	struct rdac_dh_data *h = get_rdac_data(sdev);
671 	int err = SCSI_DH_OK;
672 	int act = 0;
673 
674 	err = check_ownership(sdev, h);
675 	if (err != SCSI_DH_OK)
676 		goto done;
677 
678 	switch (h->mode) {
679 	case RDAC_MODE:
680 		if (h->lun_state == RDAC_LUN_UNOWNED)
681 			act = 1;
682 		break;
683 	case RDAC_MODE_IOSHIP:
684 		if ((h->lun_state == RDAC_LUN_UNOWNED) &&
685 		    (h->preferred == RDAC_PREFERRED))
686 			act = 1;
687 		break;
688 	default:
689 		break;
690 	}
691 
692 	if (act) {
693 		err = queue_mode_select(sdev, fn, data);
694 		if (err == SCSI_DH_OK)
695 			return 0;
696 	}
697 done:
698 	if (fn)
699 		fn(data, err);
700 	return 0;
701 }
702 
703 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
704 {
705 	struct rdac_dh_data *h = get_rdac_data(sdev);
706 	int ret = BLKPREP_OK;
707 
708 	if (h->state != RDAC_STATE_ACTIVE) {
709 		ret = BLKPREP_KILL;
710 		req->cmd_flags |= REQ_QUIET;
711 	}
712 	return ret;
713 
714 }
715 
716 static int rdac_check_sense(struct scsi_device *sdev,
717 				struct scsi_sense_hdr *sense_hdr)
718 {
719 	struct rdac_dh_data *h = get_rdac_data(sdev);
720 
721 	RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
722 			"I/O returned with sense %02x/%02x/%02x",
723 			(char *) h->ctlr->array_name, h->ctlr->index,
724 			sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
725 
726 	switch (sense_hdr->sense_key) {
727 	case NOT_READY:
728 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
729 			/* LUN Not Ready - Logical Unit Not Ready and is in
730 			* the process of becoming ready
731 			* Just retry.
732 			*/
733 			return ADD_TO_MLQUEUE;
734 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
735 			/* LUN Not Ready - Storage firmware incompatible
736 			 * Manual code synchonisation required.
737 			 *
738 			 * Nothing we can do here. Try to bypass the path.
739 			 */
740 			return SUCCESS;
741 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
742 			/* LUN Not Ready - Quiescense in progress
743 			 *
744 			 * Just retry and wait.
745 			 */
746 			return ADD_TO_MLQUEUE;
747 		if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
748 			/* LUN Not Ready - Quiescense in progress
749 			 * or has been achieved
750 			 * Just retry.
751 			 */
752 			return ADD_TO_MLQUEUE;
753 		break;
754 	case ILLEGAL_REQUEST:
755 		if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
756 			/* Invalid Request - Current Logical Unit Ownership.
757 			 * Controller is not the current owner of the LUN,
758 			 * Fail the path, so that the other path be used.
759 			 */
760 			h->state = RDAC_STATE_PASSIVE;
761 			return SUCCESS;
762 		}
763 		break;
764 	case UNIT_ATTENTION:
765 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
766 			/*
767 			 * Power On, Reset, or Bus Device Reset, just retry.
768 			 */
769 			return ADD_TO_MLQUEUE;
770 		if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
771 			/*
772 			 * Quiescence in progress , just retry.
773 			 */
774 			return ADD_TO_MLQUEUE;
775 		break;
776 	}
777 	/* success just means we do not care what scsi-ml does */
778 	return SCSI_RETURN_NOT_HANDLED;
779 }
780 
781 static const struct {
782 	char *vendor;
783 	char *model;
784 } rdac_dev_list[] = {
785 	{"IBM", "1722"},
786 	{"IBM", "1724"},
787 	{"IBM", "1726"},
788 	{"IBM", "1742"},
789 	{"IBM", "1745"},
790 	{"IBM", "1746"},
791 	{"IBM", "1813"},
792 	{"IBM", "1814"},
793 	{"IBM", "1815"},
794 	{"IBM", "1818"},
795 	{"IBM", "3526"},
796 	{"SGI", "TP9"},
797 	{"SGI", "IS"},
798 	{"STK", "OPENstorage D280"},
799 	{"STK", "FLEXLINE 380"},
800 	{"SUN", "CSM"},
801 	{"SUN", "LCSM100"},
802 	{"SUN", "STK6580_6780"},
803 	{"SUN", "SUN_6180"},
804 	{"SUN", "ArrayStorage"},
805 	{"DELL", "MD3"},
806 	{"NETAPP", "INF-01-00"},
807 	{"LSI", "INF-01-00"},
808 	{"ENGENIO", "INF-01-00"},
809 	{NULL, NULL},
810 };
811 
812 static bool rdac_match(struct scsi_device *sdev)
813 {
814 	int i;
815 
816 	if (scsi_device_tpgs(sdev))
817 		return false;
818 
819 	for (i = 0; rdac_dev_list[i].vendor; i++) {
820 		if (!strncmp(sdev->vendor, rdac_dev_list[i].vendor,
821 			strlen(rdac_dev_list[i].vendor)) &&
822 		    !strncmp(sdev->model, rdac_dev_list[i].model,
823 			strlen(rdac_dev_list[i].model))) {
824 			return true;
825 		}
826 	}
827 	return false;
828 }
829 
830 static struct scsi_dh_data *rdac_bus_attach(struct scsi_device *sdev)
831 {
832 	struct rdac_dh_data *h;
833 	int err;
834 	char array_name[ARRAY_LABEL_LEN];
835 	char array_id[UNIQUE_ID_LEN];
836 
837 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
838 	if (!h)
839 		return ERR_PTR(-ENOMEM);
840 	h->lun = UNINITIALIZED_LUN;
841 	h->state = RDAC_STATE_ACTIVE;
842 
843 	err = get_lun_info(sdev, h, array_name, array_id);
844 	if (err != SCSI_DH_OK)
845 		goto failed;
846 
847 	err = initialize_controller(sdev, h, array_name, array_id);
848 	if (err != SCSI_DH_OK)
849 		goto failed;
850 
851 	err = check_ownership(sdev, h);
852 	if (err != SCSI_DH_OK)
853 		goto clean_ctlr;
854 
855 	err = set_mode_select(sdev, h);
856 	if (err != SCSI_DH_OK)
857 		goto clean_ctlr;
858 
859 	sdev_printk(KERN_NOTICE, sdev,
860 		    "%s: LUN %d (%s) (%s)\n",
861 		    RDAC_NAME, h->lun, mode[(int)h->mode],
862 		    lun_state[(int)h->lun_state]);
863 
864 	return &h->dh_data;
865 
866 clean_ctlr:
867 	spin_lock(&list_lock);
868 	kref_put(&h->ctlr->kref, release_controller);
869 	spin_unlock(&list_lock);
870 
871 failed:
872 	kfree(h);
873 	return ERR_PTR(-EINVAL);
874 }
875 
876 static void rdac_bus_detach( struct scsi_device *sdev )
877 {
878 	struct rdac_dh_data *h = get_rdac_data(sdev);
879 
880 	if (h->ctlr && h->ctlr->ms_queued)
881 		flush_workqueue(kmpath_rdacd);
882 
883 	spin_lock(&list_lock);
884 	if (h->ctlr)
885 		kref_put(&h->ctlr->kref, release_controller);
886 	spin_unlock(&list_lock);
887 	kfree(h);
888 }
889 
890 static struct scsi_device_handler rdac_dh = {
891 	.name = RDAC_NAME,
892 	.module = THIS_MODULE,
893 	.prep_fn = rdac_prep_fn,
894 	.check_sense = rdac_check_sense,
895 	.attach = rdac_bus_attach,
896 	.detach = rdac_bus_detach,
897 	.activate = rdac_activate,
898 	.match = rdac_match,
899 };
900 
901 static int __init rdac_init(void)
902 {
903 	int r;
904 
905 	r = scsi_register_device_handler(&rdac_dh);
906 	if (r != 0) {
907 		printk(KERN_ERR "Failed to register scsi device handler.");
908 		goto done;
909 	}
910 
911 	/*
912 	 * Create workqueue to handle mode selects for rdac
913 	 */
914 	kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
915 	if (!kmpath_rdacd) {
916 		scsi_unregister_device_handler(&rdac_dh);
917 		printk(KERN_ERR "kmpath_rdacd creation failed.\n");
918 
919 		r = -EINVAL;
920 	}
921 done:
922 	return r;
923 }
924 
925 static void __exit rdac_exit(void)
926 {
927 	destroy_workqueue(kmpath_rdacd);
928 	scsi_unregister_device_handler(&rdac_dh);
929 }
930 
931 module_init(rdac_init);
932 module_exit(rdac_exit);
933 
934 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
935 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
936 MODULE_VERSION("01.00.0000.0000");
937 MODULE_LICENSE("GPL");
938