xref: /linux/drivers/scsi/device_handler/scsi_dh_rdac.c (revision 1ccd4b7bfdcfcc8cc7ffc4a9c11d3ac5b6da8ca0)
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 #define UNIQUE_ID_LEN 16
132 struct c8_inquiry {
133 	u8	peripheral_info;
134 	u8	page_code; /* 0xC8 */
135 	u8	reserved1;
136 	u8	page_len;
137 	u8	page_id[4]; /* "edid" */
138 	u8	reserved2[3];
139 	u8	vol_uniq_id_len;
140 	u8	vol_uniq_id[16];
141 	u8	vol_user_label_len;
142 	u8	vol_user_label[60];
143 	u8	array_uniq_id_len;
144 	u8	array_unique_id[UNIQUE_ID_LEN];
145 	u8	array_user_label_len;
146 	u8	array_user_label[60];
147 	u8	lun[8];
148 };
149 
150 struct rdac_controller {
151 	u8			array_id[UNIQUE_ID_LEN];
152 	int			use_ms10;
153 	struct kref		kref;
154 	struct list_head	node; /* list of all controllers */
155 	union			{
156 		struct rdac_pg_legacy legacy;
157 		struct rdac_pg_expanded expanded;
158 	} mode_select;
159 	u8	index;
160 	u8	array_name[ARRAY_LABEL_LEN];
161 	struct Scsi_Host	*host;
162 	spinlock_t		ms_lock;
163 	int			ms_queued;
164 	struct work_struct	ms_work;
165 	struct scsi_device	*ms_sdev;
166 	struct list_head	ms_head;
167 };
168 
169 struct c2_inquiry {
170 	u8	peripheral_info;
171 	u8	page_code;	/* 0xC2 */
172 	u8	reserved1;
173 	u8	page_len;
174 	u8	page_id[4];	/* "swr4" */
175 	u8	sw_version[3];
176 	u8	sw_date[3];
177 	u8	features_enabled;
178 	u8	max_lun_supported;
179 	u8	partitions[239]; /* Total allocation length should be 0xFF */
180 };
181 
182 struct rdac_dh_data {
183 	struct rdac_controller	*ctlr;
184 #define UNINITIALIZED_LUN	(1 << 8)
185 	unsigned		lun;
186 
187 #define RDAC_MODE		0
188 #define RDAC_MODE_AVT		1
189 #define RDAC_MODE_IOSHIP	2
190 	unsigned char		mode;
191 
192 #define RDAC_STATE_ACTIVE	0
193 #define RDAC_STATE_PASSIVE	1
194 	unsigned char		state;
195 
196 #define RDAC_LUN_UNOWNED	0
197 #define RDAC_LUN_OWNED		1
198 	char			lun_state;
199 
200 #define RDAC_PREFERRED		0
201 #define RDAC_NON_PREFERRED	1
202 	char			preferred;
203 
204 	unsigned char		sense[SCSI_SENSE_BUFFERSIZE];
205 	union			{
206 		struct c2_inquiry c2;
207 		struct c4_inquiry c4;
208 		struct c8_inquiry c8;
209 		struct c9_inquiry c9;
210 	} inq;
211 };
212 
213 static const char *mode[] = {
214 	"RDAC",
215 	"AVT",
216 	"IOSHIP",
217 };
218 static const char *lun_state[] =
219 {
220 	"unowned",
221 	"owned",
222 };
223 
224 struct rdac_queue_data {
225 	struct list_head	entry;
226 	struct rdac_dh_data	*h;
227 	activate_complete	callback_fn;
228 	void			*callback_data;
229 };
230 
231 static LIST_HEAD(ctlr_list);
232 static DEFINE_SPINLOCK(list_lock);
233 static struct workqueue_struct *kmpath_rdacd;
234 static void send_mode_select(struct work_struct *work);
235 
236 /*
237  * module parameter to enable rdac debug logging.
238  * 2 bits for each type of logging, only two types defined for now
239  * Can be enhanced if required at later point
240  */
241 static int rdac_logging = 1;
242 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
243 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
244 		"Default is 1 - failover logging enabled, "
245 		"set it to 0xF to enable all the logs");
246 
247 #define RDAC_LOG_FAILOVER	0
248 #define RDAC_LOG_SENSE		2
249 
250 #define RDAC_LOG_BITS		2
251 
252 #define RDAC_LOG_LEVEL(SHIFT)  \
253 	((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
254 
255 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
256 do { \
257 	if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
258 		sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
259 } while (0);
260 
261 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
262 {
263 	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
264 	BUG_ON(scsi_dh_data == NULL);
265 	return ((struct rdac_dh_data *) scsi_dh_data->buf);
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 (!rq) {
277 		sdev_printk(KERN_INFO, sdev,
278 				"get_rdac_req: blk_get_request failed.\n");
279 		return NULL;
280 	}
281 
282 	if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
283 		blk_put_request(rq);
284 		sdev_printk(KERN_INFO, sdev,
285 				"get_rdac_req: blk_rq_map_kern failed.\n");
286 		return NULL;
287 	}
288 
289 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
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 	flush_workqueue(kmpath_rdacd);
367 	spin_lock(&list_lock);
368 	list_del(&ctlr->node);
369 	spin_unlock(&list_lock);
370 	kfree(ctlr);
371 }
372 
373 static struct rdac_controller *get_controller(int index, char *array_name,
374 			u8 *array_id, struct scsi_device *sdev)
375 {
376 	struct rdac_controller *ctlr, *tmp;
377 
378 	spin_lock(&list_lock);
379 
380 	list_for_each_entry(tmp, &ctlr_list, node) {
381 		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
382 			  (tmp->index == index) &&
383 			  (tmp->host == sdev->host)) {
384 			kref_get(&tmp->kref);
385 			spin_unlock(&list_lock);
386 			return tmp;
387 		}
388 	}
389 	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
390 	if (!ctlr)
391 		goto done;
392 
393 	/* initialize fields of controller */
394 	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
395 	ctlr->index = index;
396 	ctlr->host = sdev->host;
397 	memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
398 
399 	kref_init(&ctlr->kref);
400 	ctlr->use_ms10 = -1;
401 	ctlr->ms_queued = 0;
402 	ctlr->ms_sdev = NULL;
403 	spin_lock_init(&ctlr->ms_lock);
404 	INIT_WORK(&ctlr->ms_work, send_mode_select);
405 	INIT_LIST_HEAD(&ctlr->ms_head);
406 	list_add(&ctlr->node, &ctlr_list);
407 done:
408 	spin_unlock(&list_lock);
409 	return ctlr;
410 }
411 
412 static int submit_inquiry(struct scsi_device *sdev, int page_code,
413 			  unsigned int len, struct rdac_dh_data *h)
414 {
415 	struct request *rq;
416 	struct request_queue *q = sdev->request_queue;
417 	int err = SCSI_DH_RES_TEMP_UNAVAIL;
418 
419 	rq = get_rdac_req(sdev, &h->inq, len, READ);
420 	if (!rq)
421 		goto done;
422 
423 	/* Prepare the command. */
424 	rq->cmd[0] = INQUIRY;
425 	rq->cmd[1] = 1;
426 	rq->cmd[2] = page_code;
427 	rq->cmd[4] = len;
428 	rq->cmd_len = COMMAND_SIZE(INQUIRY);
429 
430 	rq->sense = h->sense;
431 	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
432 	rq->sense_len = 0;
433 
434 	err = blk_execute_rq(q, NULL, rq, 1);
435 	if (err == -EIO)
436 		err = SCSI_DH_IO;
437 
438 	blk_put_request(rq);
439 done:
440 	return err;
441 }
442 
443 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
444 			char *array_name, u8 *array_id)
445 {
446 	int err, i;
447 	struct c8_inquiry *inqp;
448 
449 	err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
450 	if (err == SCSI_DH_OK) {
451 		inqp = &h->inq.c8;
452 		if (inqp->page_code != 0xc8)
453 			return SCSI_DH_NOSYS;
454 		if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
455 		    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
456 			return SCSI_DH_NOSYS;
457 		h->lun = inqp->lun[7]; /* Uses only the last byte */
458 
459 		for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
460 			*(array_name+i) = inqp->array_user_label[(2*i)+1];
461 
462 		*(array_name+ARRAY_LABEL_LEN-1) = '\0';
463 		memset(array_id, 0, UNIQUE_ID_LEN);
464 		memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
465 	}
466 	return err;
467 }
468 
469 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
470 {
471 	int err;
472 	struct c9_inquiry *inqp;
473 
474 	h->state = RDAC_STATE_ACTIVE;
475 	err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
476 	if (err == SCSI_DH_OK) {
477 		inqp = &h->inq.c9;
478 		/* detect the operating mode */
479 		if ((inqp->avte_cvp >> 5) & 0x1)
480 			h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
481 		else if (inqp->avte_cvp >> 7)
482 			h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
483 		else
484 			h->mode = RDAC_MODE; /* LUN in RDAC mode */
485 
486 		/* Update ownership */
487 		if (inqp->avte_cvp & 0x1)
488 			h->lun_state = RDAC_LUN_OWNED;
489 		else {
490 			h->lun_state = RDAC_LUN_UNOWNED;
491 			if (h->mode == RDAC_MODE)
492 				h->state = RDAC_STATE_PASSIVE;
493 		}
494 
495 		/* Update path prio*/
496 		if (inqp->path_prio & 0x1)
497 			h->preferred = RDAC_PREFERRED;
498 		else
499 			h->preferred = RDAC_NON_PREFERRED;
500 	}
501 
502 	return err;
503 }
504 
505 static int initialize_controller(struct scsi_device *sdev,
506 		struct rdac_dh_data *h, char *array_name, u8 *array_id)
507 {
508 	int err, index;
509 	struct c4_inquiry *inqp;
510 
511 	err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
512 	if (err == SCSI_DH_OK) {
513 		inqp = &h->inq.c4;
514 		/* get the controller index */
515 		if (inqp->slot_id[1] == 0x31)
516 			index = 0;
517 		else
518 			index = 1;
519 		h->ctlr = get_controller(index, array_name, array_id, sdev);
520 		if (!h->ctlr)
521 			err = SCSI_DH_RES_TEMP_UNAVAIL;
522 	}
523 	return err;
524 }
525 
526 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
527 {
528 	int err;
529 	struct c2_inquiry *inqp;
530 
531 	err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
532 	if (err == SCSI_DH_OK) {
533 		inqp = &h->inq.c2;
534 		/*
535 		 * If more than MODE6_MAX_LUN luns are supported, use
536 		 * mode select 10
537 		 */
538 		if (inqp->max_lun_supported >= MODE6_MAX_LUN)
539 			h->ctlr->use_ms10 = 1;
540 		else
541 			h->ctlr->use_ms10 = 0;
542 	}
543 	return err;
544 }
545 
546 static int mode_select_handle_sense(struct scsi_device *sdev,
547 					unsigned char *sensebuf)
548 {
549 	struct scsi_sense_hdr sense_hdr;
550 	int err = SCSI_DH_IO, ret;
551 	struct rdac_dh_data *h = get_rdac_data(sdev);
552 
553 	ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
554 	if (!ret)
555 		goto done;
556 
557 	switch (sense_hdr.sense_key) {
558 	case NO_SENSE:
559 	case ABORTED_COMMAND:
560 	case UNIT_ATTENTION:
561 		err = SCSI_DH_RETRY;
562 		break;
563 	case NOT_READY:
564 		if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
565 			/* LUN Not Ready and is in the Process of Becoming
566 			 * Ready
567 			 */
568 			err = SCSI_DH_RETRY;
569 		break;
570 	case ILLEGAL_REQUEST:
571 		if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
572 			/*
573 			 * Command Lock contention
574 			 */
575 			err = SCSI_DH_RETRY;
576 		break;
577 	default:
578 		break;
579 	}
580 
581 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
582 		"MODE_SELECT returned with sense %02x/%02x/%02x",
583 		(char *) h->ctlr->array_name, h->ctlr->index,
584 		sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
585 
586 done:
587 	return err;
588 }
589 
590 static void send_mode_select(struct work_struct *work)
591 {
592 	struct rdac_controller *ctlr =
593 		container_of(work, struct rdac_controller, ms_work);
594 	struct request *rq;
595 	struct scsi_device *sdev = ctlr->ms_sdev;
596 	struct rdac_dh_data *h = get_rdac_data(sdev);
597 	struct request_queue *q = sdev->request_queue;
598 	int err, retry_cnt = RDAC_RETRY_COUNT;
599 	struct rdac_queue_data *tmp, *qdata;
600 	LIST_HEAD(list);
601 
602 	spin_lock(&ctlr->ms_lock);
603 	list_splice_init(&ctlr->ms_head, &list);
604 	ctlr->ms_queued = 0;
605 	ctlr->ms_sdev = NULL;
606 	spin_unlock(&ctlr->ms_lock);
607 
608 retry:
609 	err = SCSI_DH_RES_TEMP_UNAVAIL;
610 	rq = rdac_failover_get(sdev, h, &list);
611 	if (!rq)
612 		goto done;
613 
614 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
615 		"%s MODE_SELECT command",
616 		(char *) h->ctlr->array_name, h->ctlr->index,
617 		(retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
618 
619 	err = blk_execute_rq(q, NULL, rq, 1);
620 	blk_put_request(rq);
621 	if (err != SCSI_DH_OK) {
622 		err = mode_select_handle_sense(sdev, h->sense);
623 		if (err == SCSI_DH_RETRY && retry_cnt--)
624 			goto retry;
625 	}
626 	if (err == SCSI_DH_OK) {
627 		h->state = RDAC_STATE_ACTIVE;
628 		RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
629 				"MODE_SELECT completed",
630 				(char *) h->ctlr->array_name, h->ctlr->index);
631 	}
632 
633 done:
634 	list_for_each_entry_safe(qdata, tmp, &list, entry) {
635 		list_del(&qdata->entry);
636 		if (err == SCSI_DH_OK)
637 			qdata->h->state = RDAC_STATE_ACTIVE;
638 		if (qdata->callback_fn)
639 			qdata->callback_fn(qdata->callback_data, err);
640 		kfree(qdata);
641 	}
642 	return;
643 }
644 
645 static int queue_mode_select(struct scsi_device *sdev,
646 				activate_complete fn, void *data)
647 {
648 	struct rdac_queue_data *qdata;
649 	struct rdac_controller *ctlr;
650 
651 	qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
652 	if (!qdata)
653 		return SCSI_DH_RETRY;
654 
655 	qdata->h = get_rdac_data(sdev);
656 	qdata->callback_fn = fn;
657 	qdata->callback_data = data;
658 
659 	ctlr = qdata->h->ctlr;
660 	spin_lock(&ctlr->ms_lock);
661 	list_add_tail(&qdata->entry, &ctlr->ms_head);
662 	if (!ctlr->ms_queued) {
663 		ctlr->ms_queued = 1;
664 		ctlr->ms_sdev = sdev;
665 		queue_work(kmpath_rdacd, &ctlr->ms_work);
666 	}
667 	spin_unlock(&ctlr->ms_lock);
668 	return SCSI_DH_OK;
669 }
670 
671 static int rdac_activate(struct scsi_device *sdev,
672 			activate_complete fn, void *data)
673 {
674 	struct rdac_dh_data *h = get_rdac_data(sdev);
675 	int err = SCSI_DH_OK;
676 	int act = 0;
677 
678 	err = check_ownership(sdev, h);
679 	if (err != SCSI_DH_OK)
680 		goto done;
681 
682 	switch (h->mode) {
683 	case RDAC_MODE:
684 		if (h->lun_state == RDAC_LUN_UNOWNED)
685 			act = 1;
686 		break;
687 	case RDAC_MODE_IOSHIP:
688 		if ((h->lun_state == RDAC_LUN_UNOWNED) &&
689 		    (h->preferred == RDAC_PREFERRED))
690 			act = 1;
691 		break;
692 	default:
693 		break;
694 	}
695 
696 	if (act) {
697 		err = queue_mode_select(sdev, fn, data);
698 		if (err == SCSI_DH_OK)
699 			return 0;
700 	}
701 done:
702 	if (fn)
703 		fn(data, err);
704 	return 0;
705 }
706 
707 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
708 {
709 	struct rdac_dh_data *h = get_rdac_data(sdev);
710 	int ret = BLKPREP_OK;
711 
712 	if (h->state != RDAC_STATE_ACTIVE) {
713 		ret = BLKPREP_KILL;
714 		req->cmd_flags |= REQ_QUIET;
715 	}
716 	return ret;
717 
718 }
719 
720 static int rdac_check_sense(struct scsi_device *sdev,
721 				struct scsi_sense_hdr *sense_hdr)
722 {
723 	struct rdac_dh_data *h = get_rdac_data(sdev);
724 
725 	RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
726 			"I/O returned with sense %02x/%02x/%02x",
727 			(char *) h->ctlr->array_name, h->ctlr->index,
728 			sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
729 
730 	switch (sense_hdr->sense_key) {
731 	case NOT_READY:
732 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
733 			/* LUN Not Ready - Logical Unit Not Ready and is in
734 			* the process of becoming ready
735 			* Just retry.
736 			*/
737 			return ADD_TO_MLQUEUE;
738 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
739 			/* LUN Not Ready - Storage firmware incompatible
740 			 * Manual code synchonisation required.
741 			 *
742 			 * Nothing we can do here. Try to bypass the path.
743 			 */
744 			return SUCCESS;
745 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
746 			/* LUN Not Ready - Quiescense in progress
747 			 *
748 			 * Just retry and wait.
749 			 */
750 			return ADD_TO_MLQUEUE;
751 		if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
752 			/* LUN Not Ready - Quiescense in progress
753 			 * or has been achieved
754 			 * Just retry.
755 			 */
756 			return ADD_TO_MLQUEUE;
757 		break;
758 	case ILLEGAL_REQUEST:
759 		if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
760 			/* Invalid Request - Current Logical Unit Ownership.
761 			 * Controller is not the current owner of the LUN,
762 			 * Fail the path, so that the other path be used.
763 			 */
764 			h->state = RDAC_STATE_PASSIVE;
765 			return SUCCESS;
766 		}
767 		break;
768 	case UNIT_ATTENTION:
769 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
770 			/*
771 			 * Power On, Reset, or Bus Device Reset, just retry.
772 			 */
773 			return ADD_TO_MLQUEUE;
774 		if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
775 			/*
776 			 * Quiescence in progress , just retry.
777 			 */
778 			return ADD_TO_MLQUEUE;
779 		break;
780 	}
781 	/* success just means we do not care what scsi-ml does */
782 	return SCSI_RETURN_NOT_HANDLED;
783 }
784 
785 static const struct scsi_dh_devlist rdac_dev_list[] = {
786 	{"IBM", "1722"},
787 	{"IBM", "1724"},
788 	{"IBM", "1726"},
789 	{"IBM", "1742"},
790 	{"IBM", "1745"},
791 	{"IBM", "1746"},
792 	{"IBM", "1814"},
793 	{"IBM", "1815"},
794 	{"IBM", "1818"},
795 	{"IBM", "3526"},
796 	{"SGI", "TP9400"},
797 	{"SGI", "TP9500"},
798 	{"SGI", "IS"},
799 	{"STK", "OPENstorage D280"},
800 	{"SUN", "CSM200_R"},
801 	{"SUN", "LCSM100_I"},
802 	{"SUN", "LCSM100_S"},
803 	{"SUN", "LCSM100_E"},
804 	{"SUN", "LCSM100_F"},
805 	{"DELL", "MD3000"},
806 	{"DELL", "MD3000i"},
807 	{"DELL", "MD32xx"},
808 	{"DELL", "MD32xxi"},
809 	{"DELL", "MD36xxi"},
810 	{"DELL", "MD36xxf"},
811 	{"LSI", "INF-01-00"},
812 	{"ENGENIO", "INF-01-00"},
813 	{"STK", "FLEXLINE 380"},
814 	{"SUN", "CSM100_R_FC"},
815 	{"SUN", "STK6580_6780"},
816 	{"SUN", "SUN_6180"},
817 	{NULL, NULL},
818 };
819 
820 static int rdac_bus_attach(struct scsi_device *sdev);
821 static void rdac_bus_detach(struct scsi_device *sdev);
822 
823 static struct scsi_device_handler rdac_dh = {
824 	.name = RDAC_NAME,
825 	.module = THIS_MODULE,
826 	.devlist = rdac_dev_list,
827 	.prep_fn = rdac_prep_fn,
828 	.check_sense = rdac_check_sense,
829 	.attach = rdac_bus_attach,
830 	.detach = rdac_bus_detach,
831 	.activate = rdac_activate,
832 };
833 
834 static int rdac_bus_attach(struct scsi_device *sdev)
835 {
836 	struct scsi_dh_data *scsi_dh_data;
837 	struct rdac_dh_data *h;
838 	unsigned long flags;
839 	int err;
840 	char array_name[ARRAY_LABEL_LEN];
841 	char array_id[UNIQUE_ID_LEN];
842 
843 	scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
844 			       + sizeof(*h) , GFP_KERNEL);
845 	if (!scsi_dh_data) {
846 		sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
847 			    RDAC_NAME);
848 		return 0;
849 	}
850 
851 	scsi_dh_data->scsi_dh = &rdac_dh;
852 	h = (struct rdac_dh_data *) scsi_dh_data->buf;
853 	h->lun = UNINITIALIZED_LUN;
854 	h->state = RDAC_STATE_ACTIVE;
855 
856 	err = get_lun_info(sdev, h, array_name, array_id);
857 	if (err != SCSI_DH_OK)
858 		goto failed;
859 
860 	err = initialize_controller(sdev, h, array_name, array_id);
861 	if (err != SCSI_DH_OK)
862 		goto failed;
863 
864 	err = check_ownership(sdev, h);
865 	if (err != SCSI_DH_OK)
866 		goto clean_ctlr;
867 
868 	err = set_mode_select(sdev, h);
869 	if (err != SCSI_DH_OK)
870 		goto clean_ctlr;
871 
872 	if (!try_module_get(THIS_MODULE))
873 		goto clean_ctlr;
874 
875 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
876 	sdev->scsi_dh_data = scsi_dh_data;
877 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
878 
879 	sdev_printk(KERN_NOTICE, sdev,
880 		    "%s: LUN %d (%s) (%s)\n",
881 		    RDAC_NAME, h->lun, mode[(int)h->mode],
882 		    lun_state[(int)h->lun_state]);
883 
884 	return 0;
885 
886 clean_ctlr:
887 	kref_put(&h->ctlr->kref, release_controller);
888 
889 failed:
890 	kfree(scsi_dh_data);
891 	sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
892 		    RDAC_NAME);
893 	return -EINVAL;
894 }
895 
896 static void rdac_bus_detach( struct scsi_device *sdev )
897 {
898 	struct scsi_dh_data *scsi_dh_data;
899 	struct rdac_dh_data *h;
900 	unsigned long flags;
901 
902 	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
903 	scsi_dh_data = sdev->scsi_dh_data;
904 	sdev->scsi_dh_data = NULL;
905 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
906 
907 	h = (struct rdac_dh_data *) scsi_dh_data->buf;
908 	if (h->ctlr)
909 		kref_put(&h->ctlr->kref, release_controller);
910 	kfree(scsi_dh_data);
911 	module_put(THIS_MODULE);
912 	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
913 }
914 
915 
916 
917 static int __init rdac_init(void)
918 {
919 	int r;
920 
921 	r = scsi_register_device_handler(&rdac_dh);
922 	if (r != 0) {
923 		printk(KERN_ERR "Failed to register scsi device handler.");
924 		goto done;
925 	}
926 
927 	/*
928 	 * Create workqueue to handle mode selects for rdac
929 	 */
930 	kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
931 	if (!kmpath_rdacd) {
932 		scsi_unregister_device_handler(&rdac_dh);
933 		printk(KERN_ERR "kmpath_rdacd creation failed.\n");
934 	}
935 done:
936 	return r;
937 }
938 
939 static void __exit rdac_exit(void)
940 {
941 	destroy_workqueue(kmpath_rdacd);
942 	scsi_unregister_device_handler(&rdac_dh);
943 }
944 
945 module_init(rdac_init);
946 module_exit(rdac_exit);
947 
948 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver");
949 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
950 MODULE_VERSION("01.00.0000.0000");
951 MODULE_LICENSE("GPL");
952