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 26 #define RDAC_NAME "rdac" 27 28 /* 29 * LSI mode page stuff 30 * 31 * These struct definitions and the forming of the 32 * mode page were taken from the LSI RDAC 2.4 GPL'd 33 * driver, and then converted to Linux conventions. 34 */ 35 #define RDAC_QUIESCENCE_TIME 20; 36 /* 37 * Page Codes 38 */ 39 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c 40 41 /* 42 * Controller modes definitions 43 */ 44 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS 0x02 45 46 /* 47 * RDAC Options field 48 */ 49 #define RDAC_FORCED_QUIESENCE 0x02 50 51 #define RDAC_TIMEOUT (60 * HZ) 52 #define RDAC_RETRIES 3 53 54 struct rdac_mode_6_hdr { 55 u8 data_len; 56 u8 medium_type; 57 u8 device_params; 58 u8 block_desc_len; 59 }; 60 61 struct rdac_mode_10_hdr { 62 u16 data_len; 63 u8 medium_type; 64 u8 device_params; 65 u16 reserved; 66 u16 block_desc_len; 67 }; 68 69 struct rdac_mode_common { 70 u8 controller_serial[16]; 71 u8 alt_controller_serial[16]; 72 u8 rdac_mode[2]; 73 u8 alt_rdac_mode[2]; 74 u8 quiescence_timeout; 75 u8 rdac_options; 76 }; 77 78 struct rdac_pg_legacy { 79 struct rdac_mode_6_hdr hdr; 80 u8 page_code; 81 u8 page_len; 82 struct rdac_mode_common common; 83 #define MODE6_MAX_LUN 32 84 u8 lun_table[MODE6_MAX_LUN]; 85 u8 reserved2[32]; 86 u8 reserved3; 87 u8 reserved4; 88 }; 89 90 struct rdac_pg_expanded { 91 struct rdac_mode_10_hdr hdr; 92 u8 page_code; 93 u8 subpage_code; 94 u8 page_len[2]; 95 struct rdac_mode_common common; 96 u8 lun_table[256]; 97 u8 reserved3; 98 u8 reserved4; 99 }; 100 101 struct c9_inquiry { 102 u8 peripheral_info; 103 u8 page_code; /* 0xC9 */ 104 u8 reserved1; 105 u8 page_len; 106 u8 page_id[4]; /* "vace" */ 107 u8 avte_cvp; 108 u8 path_prio; 109 u8 reserved2[38]; 110 }; 111 112 #define SUBSYS_ID_LEN 16 113 #define SLOT_ID_LEN 2 114 115 struct c4_inquiry { 116 u8 peripheral_info; 117 u8 page_code; /* 0xC4 */ 118 u8 reserved1; 119 u8 page_len; 120 u8 page_id[4]; /* "subs" */ 121 u8 subsys_id[SUBSYS_ID_LEN]; 122 u8 revision[4]; 123 u8 slot_id[SLOT_ID_LEN]; 124 u8 reserved[2]; 125 }; 126 127 struct rdac_controller { 128 u8 subsys_id[SUBSYS_ID_LEN]; 129 u8 slot_id[SLOT_ID_LEN]; 130 int use_ms10; 131 struct kref kref; 132 struct list_head node; /* list of all controllers */ 133 union { 134 struct rdac_pg_legacy legacy; 135 struct rdac_pg_expanded expanded; 136 } mode_select; 137 }; 138 struct c8_inquiry { 139 u8 peripheral_info; 140 u8 page_code; /* 0xC8 */ 141 u8 reserved1; 142 u8 page_len; 143 u8 page_id[4]; /* "edid" */ 144 u8 reserved2[3]; 145 u8 vol_uniq_id_len; 146 u8 vol_uniq_id[16]; 147 u8 vol_user_label_len; 148 u8 vol_user_label[60]; 149 u8 array_uniq_id_len; 150 u8 array_unique_id[16]; 151 u8 array_user_label_len; 152 u8 array_user_label[60]; 153 u8 lun[8]; 154 }; 155 156 struct c2_inquiry { 157 u8 peripheral_info; 158 u8 page_code; /* 0xC2 */ 159 u8 reserved1; 160 u8 page_len; 161 u8 page_id[4]; /* "swr4" */ 162 u8 sw_version[3]; 163 u8 sw_date[3]; 164 u8 features_enabled; 165 u8 max_lun_supported; 166 u8 partitions[239]; /* Total allocation length should be 0xFF */ 167 }; 168 169 struct rdac_dh_data { 170 struct rdac_controller *ctlr; 171 #define UNINITIALIZED_LUN (1 << 8) 172 unsigned lun; 173 #define RDAC_STATE_ACTIVE 0 174 #define RDAC_STATE_PASSIVE 1 175 unsigned char state; 176 177 #define RDAC_LUN_UNOWNED 0 178 #define RDAC_LUN_OWNED 1 179 #define RDAC_LUN_AVT 2 180 char lun_state; 181 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 182 union { 183 struct c2_inquiry c2; 184 struct c4_inquiry c4; 185 struct c8_inquiry c8; 186 struct c9_inquiry c9; 187 } inq; 188 }; 189 190 static const char *lun_state[] = 191 { 192 "unowned", 193 "owned", 194 "owned (AVT mode)", 195 }; 196 197 static LIST_HEAD(ctlr_list); 198 static DEFINE_SPINLOCK(list_lock); 199 200 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev) 201 { 202 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; 203 BUG_ON(scsi_dh_data == NULL); 204 return ((struct rdac_dh_data *) scsi_dh_data->buf); 205 } 206 207 static struct request *get_rdac_req(struct scsi_device *sdev, 208 void *buffer, unsigned buflen, int rw) 209 { 210 struct request *rq; 211 struct request_queue *q = sdev->request_queue; 212 213 rq = blk_get_request(q, rw, GFP_NOIO); 214 215 if (!rq) { 216 sdev_printk(KERN_INFO, sdev, 217 "get_rdac_req: blk_get_request failed.\n"); 218 return NULL; 219 } 220 221 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { 222 blk_put_request(rq); 223 sdev_printk(KERN_INFO, sdev, 224 "get_rdac_req: blk_rq_map_kern failed.\n"); 225 return NULL; 226 } 227 228 rq->cmd_type = REQ_TYPE_BLOCK_PC; 229 rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | 230 REQ_FAILFAST_DRIVER; 231 rq->retries = RDAC_RETRIES; 232 rq->timeout = RDAC_TIMEOUT; 233 234 return rq; 235 } 236 237 static struct request *rdac_failover_get(struct scsi_device *sdev, 238 struct rdac_dh_data *h) 239 { 240 struct request *rq; 241 struct rdac_mode_common *common; 242 unsigned data_size; 243 244 if (h->ctlr->use_ms10) { 245 struct rdac_pg_expanded *rdac_pg; 246 247 data_size = sizeof(struct rdac_pg_expanded); 248 rdac_pg = &h->ctlr->mode_select.expanded; 249 memset(rdac_pg, 0, data_size); 250 common = &rdac_pg->common; 251 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40; 252 rdac_pg->subpage_code = 0x1; 253 rdac_pg->page_len[0] = 0x01; 254 rdac_pg->page_len[1] = 0x28; 255 rdac_pg->lun_table[h->lun] = 0x81; 256 } else { 257 struct rdac_pg_legacy *rdac_pg; 258 259 data_size = sizeof(struct rdac_pg_legacy); 260 rdac_pg = &h->ctlr->mode_select.legacy; 261 memset(rdac_pg, 0, data_size); 262 common = &rdac_pg->common; 263 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER; 264 rdac_pg->page_len = 0x68; 265 rdac_pg->lun_table[h->lun] = 0x81; 266 } 267 common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS; 268 common->quiescence_timeout = RDAC_QUIESCENCE_TIME; 269 common->rdac_options = RDAC_FORCED_QUIESENCE; 270 271 /* get request for block layer packet command */ 272 rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE); 273 if (!rq) 274 return NULL; 275 276 /* Prepare the command. */ 277 if (h->ctlr->use_ms10) { 278 rq->cmd[0] = MODE_SELECT_10; 279 rq->cmd[7] = data_size >> 8; 280 rq->cmd[8] = data_size & 0xff; 281 } else { 282 rq->cmd[0] = MODE_SELECT; 283 rq->cmd[4] = data_size; 284 } 285 rq->cmd_len = COMMAND_SIZE(rq->cmd[0]); 286 287 rq->sense = h->sense; 288 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 289 rq->sense_len = 0; 290 291 return rq; 292 } 293 294 static void release_controller(struct kref *kref) 295 { 296 struct rdac_controller *ctlr; 297 ctlr = container_of(kref, struct rdac_controller, kref); 298 299 spin_lock(&list_lock); 300 list_del(&ctlr->node); 301 spin_unlock(&list_lock); 302 kfree(ctlr); 303 } 304 305 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id) 306 { 307 struct rdac_controller *ctlr, *tmp; 308 309 spin_lock(&list_lock); 310 311 list_for_each_entry(tmp, &ctlr_list, node) { 312 if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) && 313 (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) { 314 kref_get(&tmp->kref); 315 spin_unlock(&list_lock); 316 return tmp; 317 } 318 } 319 ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC); 320 if (!ctlr) 321 goto done; 322 323 /* initialize fields of controller */ 324 memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN); 325 memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN); 326 kref_init(&ctlr->kref); 327 ctlr->use_ms10 = -1; 328 list_add(&ctlr->node, &ctlr_list); 329 done: 330 spin_unlock(&list_lock); 331 return ctlr; 332 } 333 334 static int submit_inquiry(struct scsi_device *sdev, int page_code, 335 unsigned int len, struct rdac_dh_data *h) 336 { 337 struct request *rq; 338 struct request_queue *q = sdev->request_queue; 339 int err = SCSI_DH_RES_TEMP_UNAVAIL; 340 341 rq = get_rdac_req(sdev, &h->inq, len, READ); 342 if (!rq) 343 goto done; 344 345 /* Prepare the command. */ 346 rq->cmd[0] = INQUIRY; 347 rq->cmd[1] = 1; 348 rq->cmd[2] = page_code; 349 rq->cmd[4] = len; 350 rq->cmd_len = COMMAND_SIZE(INQUIRY); 351 352 rq->sense = h->sense; 353 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 354 rq->sense_len = 0; 355 356 err = blk_execute_rq(q, NULL, rq, 1); 357 if (err == -EIO) 358 err = SCSI_DH_IO; 359 360 blk_put_request(rq); 361 done: 362 return err; 363 } 364 365 static int get_lun(struct scsi_device *sdev, struct rdac_dh_data *h) 366 { 367 int err; 368 struct c8_inquiry *inqp; 369 370 err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h); 371 if (err == SCSI_DH_OK) { 372 inqp = &h->inq.c8; 373 if (inqp->page_code != 0xc8) 374 return SCSI_DH_NOSYS; 375 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' || 376 inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd') 377 return SCSI_DH_NOSYS; 378 h->lun = inqp->lun[7]; /* Uses only the last byte */ 379 } 380 return err; 381 } 382 383 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h) 384 { 385 int err; 386 struct c9_inquiry *inqp; 387 388 h->lun_state = RDAC_LUN_UNOWNED; 389 err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h); 390 if (err == SCSI_DH_OK) { 391 inqp = &h->inq.c9; 392 if ((inqp->avte_cvp >> 7) == 0x1) { 393 /* LUN in AVT mode */ 394 sdev_printk(KERN_NOTICE, sdev, 395 "%s: AVT mode detected\n", 396 RDAC_NAME); 397 h->lun_state = RDAC_LUN_AVT; 398 } else if ((inqp->avte_cvp & 0x1) != 0) { 399 /* LUN was owned by the controller */ 400 h->lun_state = RDAC_LUN_OWNED; 401 } 402 } 403 404 if (h->lun_state == RDAC_LUN_UNOWNED) 405 h->state = RDAC_STATE_PASSIVE; 406 407 return err; 408 } 409 410 static int initialize_controller(struct scsi_device *sdev, 411 struct rdac_dh_data *h) 412 { 413 int err; 414 struct c4_inquiry *inqp; 415 416 err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h); 417 if (err == SCSI_DH_OK) { 418 inqp = &h->inq.c4; 419 h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id); 420 if (!h->ctlr) 421 err = SCSI_DH_RES_TEMP_UNAVAIL; 422 } 423 return err; 424 } 425 426 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h) 427 { 428 int err; 429 struct c2_inquiry *inqp; 430 431 err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h); 432 if (err == SCSI_DH_OK) { 433 inqp = &h->inq.c2; 434 /* 435 * If more than MODE6_MAX_LUN luns are supported, use 436 * mode select 10 437 */ 438 if (inqp->max_lun_supported >= MODE6_MAX_LUN) 439 h->ctlr->use_ms10 = 1; 440 else 441 h->ctlr->use_ms10 = 0; 442 } 443 return err; 444 } 445 446 static int mode_select_handle_sense(struct scsi_device *sdev, 447 unsigned char *sensebuf) 448 { 449 struct scsi_sense_hdr sense_hdr; 450 int sense, err = SCSI_DH_IO, ret; 451 452 ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr); 453 if (!ret) 454 goto done; 455 456 err = SCSI_DH_OK; 457 sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) | 458 sense_hdr.ascq; 459 /* If it is retryable failure, submit the c9 inquiry again */ 460 if (sense == 0x59136 || sense == 0x68b02 || sense == 0xb8b02 || 461 sense == 0x62900) { 462 /* 0x59136 - Command lock contention 463 * 0x[6b]8b02 - Quiesense in progress or achieved 464 * 0x62900 - Power On, Reset, or Bus Device Reset 465 */ 466 err = SCSI_DH_RETRY; 467 } 468 469 if (sense) 470 sdev_printk(KERN_INFO, sdev, 471 "MODE_SELECT failed with sense 0x%x.\n", sense); 472 done: 473 return err; 474 } 475 476 static int send_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h) 477 { 478 struct request *rq; 479 struct request_queue *q = sdev->request_queue; 480 int err = SCSI_DH_RES_TEMP_UNAVAIL; 481 482 rq = rdac_failover_get(sdev, h); 483 if (!rq) 484 goto done; 485 486 sdev_printk(KERN_INFO, sdev, "queueing MODE_SELECT command.\n"); 487 488 err = blk_execute_rq(q, NULL, rq, 1); 489 if (err != SCSI_DH_OK) 490 err = mode_select_handle_sense(sdev, h->sense); 491 if (err == SCSI_DH_OK) 492 h->state = RDAC_STATE_ACTIVE; 493 494 blk_put_request(rq); 495 done: 496 return err; 497 } 498 499 static int rdac_activate(struct scsi_device *sdev) 500 { 501 struct rdac_dh_data *h = get_rdac_data(sdev); 502 int err = SCSI_DH_OK; 503 504 err = check_ownership(sdev, h); 505 if (err != SCSI_DH_OK) 506 goto done; 507 508 if (!h->ctlr) { 509 err = initialize_controller(sdev, h); 510 if (err != SCSI_DH_OK) 511 goto done; 512 } 513 514 if (h->ctlr->use_ms10 == -1) { 515 err = set_mode_select(sdev, h); 516 if (err != SCSI_DH_OK) 517 goto done; 518 } 519 if (h->lun_state == RDAC_LUN_UNOWNED) 520 err = send_mode_select(sdev, h); 521 done: 522 return err; 523 } 524 525 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req) 526 { 527 struct rdac_dh_data *h = get_rdac_data(sdev); 528 int ret = BLKPREP_OK; 529 530 if (h->state != RDAC_STATE_ACTIVE) { 531 ret = BLKPREP_KILL; 532 req->cmd_flags |= REQ_QUIET; 533 } 534 return ret; 535 536 } 537 538 static int rdac_check_sense(struct scsi_device *sdev, 539 struct scsi_sense_hdr *sense_hdr) 540 { 541 struct rdac_dh_data *h = get_rdac_data(sdev); 542 switch (sense_hdr->sense_key) { 543 case NOT_READY: 544 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81) 545 /* LUN Not Ready - Storage firmware incompatible 546 * Manual code synchonisation required. 547 * 548 * Nothing we can do here. Try to bypass the path. 549 */ 550 return SUCCESS; 551 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1) 552 /* LUN Not Ready - Quiescense in progress 553 * 554 * Just retry and wait. 555 */ 556 return ADD_TO_MLQUEUE; 557 break; 558 case ILLEGAL_REQUEST: 559 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) { 560 /* Invalid Request - Current Logical Unit Ownership. 561 * Controller is not the current owner of the LUN, 562 * Fail the path, so that the other path be used. 563 */ 564 h->state = RDAC_STATE_PASSIVE; 565 return SUCCESS; 566 } 567 break; 568 case UNIT_ATTENTION: 569 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) 570 /* 571 * Power On, Reset, or Bus Device Reset, just retry. 572 */ 573 return ADD_TO_MLQUEUE; 574 break; 575 } 576 /* success just means we do not care what scsi-ml does */ 577 return SCSI_RETURN_NOT_HANDLED; 578 } 579 580 static const struct scsi_dh_devlist rdac_dev_list[] = { 581 {"IBM", "1722"}, 582 {"IBM", "1724"}, 583 {"IBM", "1726"}, 584 {"IBM", "1742"}, 585 {"IBM", "1814"}, 586 {"IBM", "1815"}, 587 {"IBM", "1818"}, 588 {"IBM", "3526"}, 589 {"SGI", "TP9400"}, 590 {"SGI", "TP9500"}, 591 {"SGI", "IS"}, 592 {"STK", "OPENstorage D280"}, 593 {"SUN", "CSM200_R"}, 594 {"SUN", "LCSM100_F"}, 595 {"DELL", "MD3000"}, 596 {"DELL", "MD3000i"}, 597 {NULL, NULL}, 598 }; 599 600 static int rdac_bus_attach(struct scsi_device *sdev); 601 static void rdac_bus_detach(struct scsi_device *sdev); 602 603 static struct scsi_device_handler rdac_dh = { 604 .name = RDAC_NAME, 605 .module = THIS_MODULE, 606 .devlist = rdac_dev_list, 607 .prep_fn = rdac_prep_fn, 608 .check_sense = rdac_check_sense, 609 .attach = rdac_bus_attach, 610 .detach = rdac_bus_detach, 611 .activate = rdac_activate, 612 }; 613 614 static int rdac_bus_attach(struct scsi_device *sdev) 615 { 616 struct scsi_dh_data *scsi_dh_data; 617 struct rdac_dh_data *h; 618 unsigned long flags; 619 int err; 620 621 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *) 622 + sizeof(*h) , GFP_KERNEL); 623 if (!scsi_dh_data) { 624 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", 625 RDAC_NAME); 626 return 0; 627 } 628 629 scsi_dh_data->scsi_dh = &rdac_dh; 630 h = (struct rdac_dh_data *) scsi_dh_data->buf; 631 h->lun = UNINITIALIZED_LUN; 632 h->state = RDAC_STATE_ACTIVE; 633 634 err = get_lun(sdev, h); 635 if (err != SCSI_DH_OK) 636 goto failed; 637 638 err = check_ownership(sdev, h); 639 if (err != SCSI_DH_OK) 640 goto failed; 641 642 if (!try_module_get(THIS_MODULE)) 643 goto failed; 644 645 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 646 sdev->scsi_dh_data = scsi_dh_data; 647 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 648 649 sdev_printk(KERN_NOTICE, sdev, 650 "%s: LUN %d (%s)\n", 651 RDAC_NAME, h->lun, lun_state[(int)h->lun_state]); 652 653 return 0; 654 655 failed: 656 kfree(scsi_dh_data); 657 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", 658 RDAC_NAME); 659 return -EINVAL; 660 } 661 662 static void rdac_bus_detach( struct scsi_device *sdev ) 663 { 664 struct scsi_dh_data *scsi_dh_data; 665 struct rdac_dh_data *h; 666 unsigned long flags; 667 668 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 669 scsi_dh_data = sdev->scsi_dh_data; 670 sdev->scsi_dh_data = NULL; 671 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 672 673 h = (struct rdac_dh_data *) scsi_dh_data->buf; 674 if (h->ctlr) 675 kref_put(&h->ctlr->kref, release_controller); 676 kfree(scsi_dh_data); 677 module_put(THIS_MODULE); 678 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME); 679 } 680 681 682 683 static int __init rdac_init(void) 684 { 685 int r; 686 687 r = scsi_register_device_handler(&rdac_dh); 688 if (r != 0) 689 printk(KERN_ERR "Failed to register scsi device handler."); 690 return r; 691 } 692 693 static void __exit rdac_exit(void) 694 { 695 scsi_unregister_device_handler(&rdac_dh); 696 } 697 698 module_init(rdac_init); 699 module_exit(rdac_exit); 700 701 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver"); 702 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman"); 703 MODULE_LICENSE("GPL"); 704