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 | REQ_NOMERGE; 230 rq->retries = RDAC_RETRIES; 231 rq->timeout = RDAC_TIMEOUT; 232 233 return rq; 234 } 235 236 static struct request *rdac_failover_get(struct scsi_device *sdev, 237 struct rdac_dh_data *h) 238 { 239 struct request *rq; 240 struct rdac_mode_common *common; 241 unsigned data_size; 242 243 if (h->ctlr->use_ms10) { 244 struct rdac_pg_expanded *rdac_pg; 245 246 data_size = sizeof(struct rdac_pg_expanded); 247 rdac_pg = &h->ctlr->mode_select.expanded; 248 memset(rdac_pg, 0, data_size); 249 common = &rdac_pg->common; 250 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40; 251 rdac_pg->subpage_code = 0x1; 252 rdac_pg->page_len[0] = 0x01; 253 rdac_pg->page_len[1] = 0x28; 254 rdac_pg->lun_table[h->lun] = 0x81; 255 } else { 256 struct rdac_pg_legacy *rdac_pg; 257 258 data_size = sizeof(struct rdac_pg_legacy); 259 rdac_pg = &h->ctlr->mode_select.legacy; 260 memset(rdac_pg, 0, data_size); 261 common = &rdac_pg->common; 262 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER; 263 rdac_pg->page_len = 0x68; 264 rdac_pg->lun_table[h->lun] = 0x81; 265 } 266 common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS; 267 common->quiescence_timeout = RDAC_QUIESCENCE_TIME; 268 common->rdac_options = RDAC_FORCED_QUIESENCE; 269 270 /* get request for block layer packet command */ 271 rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE); 272 if (!rq) 273 return NULL; 274 275 /* Prepare the command. */ 276 if (h->ctlr->use_ms10) { 277 rq->cmd[0] = MODE_SELECT_10; 278 rq->cmd[7] = data_size >> 8; 279 rq->cmd[8] = data_size & 0xff; 280 } else { 281 rq->cmd[0] = MODE_SELECT; 282 rq->cmd[4] = data_size; 283 } 284 rq->cmd_len = COMMAND_SIZE(rq->cmd[0]); 285 286 rq->sense = h->sense; 287 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 288 rq->sense_len = 0; 289 290 return rq; 291 } 292 293 static void release_controller(struct kref *kref) 294 { 295 struct rdac_controller *ctlr; 296 ctlr = container_of(kref, struct rdac_controller, kref); 297 298 spin_lock(&list_lock); 299 list_del(&ctlr->node); 300 spin_unlock(&list_lock); 301 kfree(ctlr); 302 } 303 304 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id) 305 { 306 struct rdac_controller *ctlr, *tmp; 307 308 spin_lock(&list_lock); 309 310 list_for_each_entry(tmp, &ctlr_list, node) { 311 if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) && 312 (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) { 313 kref_get(&tmp->kref); 314 spin_unlock(&list_lock); 315 return tmp; 316 } 317 } 318 ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC); 319 if (!ctlr) 320 goto done; 321 322 /* initialize fields of controller */ 323 memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN); 324 memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN); 325 kref_init(&ctlr->kref); 326 ctlr->use_ms10 = -1; 327 list_add(&ctlr->node, &ctlr_list); 328 done: 329 spin_unlock(&list_lock); 330 return ctlr; 331 } 332 333 static int submit_inquiry(struct scsi_device *sdev, int page_code, 334 unsigned int len, struct rdac_dh_data *h) 335 { 336 struct request *rq; 337 struct request_queue *q = sdev->request_queue; 338 int err = SCSI_DH_RES_TEMP_UNAVAIL; 339 340 rq = get_rdac_req(sdev, &h->inq, len, READ); 341 if (!rq) 342 goto done; 343 344 /* Prepare the command. */ 345 rq->cmd[0] = INQUIRY; 346 rq->cmd[1] = 1; 347 rq->cmd[2] = page_code; 348 rq->cmd[4] = len; 349 rq->cmd_len = COMMAND_SIZE(INQUIRY); 350 351 rq->sense = h->sense; 352 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 353 rq->sense_len = 0; 354 355 err = blk_execute_rq(q, NULL, rq, 1); 356 if (err == -EIO) 357 err = SCSI_DH_IO; 358 359 blk_put_request(rq); 360 done: 361 return err; 362 } 363 364 static int get_lun(struct scsi_device *sdev, struct rdac_dh_data *h) 365 { 366 int err; 367 struct c8_inquiry *inqp; 368 369 err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h); 370 if (err == SCSI_DH_OK) { 371 inqp = &h->inq.c8; 372 if (inqp->page_code != 0xc8) 373 return SCSI_DH_NOSYS; 374 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' || 375 inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd') 376 return SCSI_DH_NOSYS; 377 h->lun = inqp->lun[7]; /* Uses only the last byte */ 378 } 379 return err; 380 } 381 382 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h) 383 { 384 int err; 385 struct c9_inquiry *inqp; 386 387 h->lun_state = RDAC_LUN_UNOWNED; 388 err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h); 389 if (err == SCSI_DH_OK) { 390 inqp = &h->inq.c9; 391 if ((inqp->avte_cvp >> 7) == 0x1) { 392 /* LUN in AVT mode */ 393 sdev_printk(KERN_NOTICE, sdev, 394 "%s: AVT mode detected\n", 395 RDAC_NAME); 396 h->lun_state = RDAC_LUN_AVT; 397 } else if ((inqp->avte_cvp & 0x1) != 0) { 398 /* LUN was owned by the controller */ 399 h->lun_state = RDAC_LUN_OWNED; 400 } 401 } 402 403 return err; 404 } 405 406 static int initialize_controller(struct scsi_device *sdev, 407 struct rdac_dh_data *h) 408 { 409 int err; 410 struct c4_inquiry *inqp; 411 412 err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h); 413 if (err == SCSI_DH_OK) { 414 inqp = &h->inq.c4; 415 h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id); 416 if (!h->ctlr) 417 err = SCSI_DH_RES_TEMP_UNAVAIL; 418 } 419 return err; 420 } 421 422 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h) 423 { 424 int err; 425 struct c2_inquiry *inqp; 426 427 err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h); 428 if (err == SCSI_DH_OK) { 429 inqp = &h->inq.c2; 430 /* 431 * If more than MODE6_MAX_LUN luns are supported, use 432 * mode select 10 433 */ 434 if (inqp->max_lun_supported >= MODE6_MAX_LUN) 435 h->ctlr->use_ms10 = 1; 436 else 437 h->ctlr->use_ms10 = 0; 438 } 439 return err; 440 } 441 442 static int mode_select_handle_sense(struct scsi_device *sdev, 443 unsigned char *sensebuf) 444 { 445 struct scsi_sense_hdr sense_hdr; 446 int sense, err = SCSI_DH_IO, ret; 447 448 ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr); 449 if (!ret) 450 goto done; 451 452 err = SCSI_DH_OK; 453 sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) | 454 sense_hdr.ascq; 455 /* If it is retryable failure, submit the c9 inquiry again */ 456 if (sense == 0x59136 || sense == 0x68b02 || sense == 0xb8b02 || 457 sense == 0x62900) { 458 /* 0x59136 - Command lock contention 459 * 0x[6b]8b02 - Quiesense in progress or achieved 460 * 0x62900 - Power On, Reset, or Bus Device Reset 461 */ 462 err = SCSI_DH_RETRY; 463 } 464 465 if (sense) 466 sdev_printk(KERN_INFO, sdev, 467 "MODE_SELECT failed with sense 0x%x.\n", sense); 468 done: 469 return err; 470 } 471 472 static int send_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h) 473 { 474 struct request *rq; 475 struct request_queue *q = sdev->request_queue; 476 int err = SCSI_DH_RES_TEMP_UNAVAIL; 477 478 rq = rdac_failover_get(sdev, h); 479 if (!rq) 480 goto done; 481 482 sdev_printk(KERN_INFO, sdev, "queueing MODE_SELECT command.\n"); 483 484 err = blk_execute_rq(q, NULL, rq, 1); 485 if (err != SCSI_DH_OK) 486 err = mode_select_handle_sense(sdev, h->sense); 487 if (err == SCSI_DH_OK) 488 h->state = RDAC_STATE_ACTIVE; 489 490 blk_put_request(rq); 491 done: 492 return err; 493 } 494 495 static int rdac_activate(struct scsi_device *sdev) 496 { 497 struct rdac_dh_data *h = get_rdac_data(sdev); 498 int err = SCSI_DH_OK; 499 500 err = check_ownership(sdev, h); 501 if (err != SCSI_DH_OK) 502 goto done; 503 504 if (!h->ctlr) { 505 err = initialize_controller(sdev, h); 506 if (err != SCSI_DH_OK) 507 goto done; 508 } 509 510 if (h->ctlr->use_ms10 == -1) { 511 err = set_mode_select(sdev, h); 512 if (err != SCSI_DH_OK) 513 goto done; 514 } 515 if (h->lun_state == RDAC_LUN_UNOWNED) 516 err = send_mode_select(sdev, h); 517 done: 518 return err; 519 } 520 521 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req) 522 { 523 struct rdac_dh_data *h = get_rdac_data(sdev); 524 int ret = BLKPREP_OK; 525 526 if (h->state != RDAC_STATE_ACTIVE) { 527 ret = BLKPREP_KILL; 528 req->cmd_flags |= REQ_QUIET; 529 } 530 return ret; 531 532 } 533 534 static int rdac_check_sense(struct scsi_device *sdev, 535 struct scsi_sense_hdr *sense_hdr) 536 { 537 struct rdac_dh_data *h = get_rdac_data(sdev); 538 switch (sense_hdr->sense_key) { 539 case NOT_READY: 540 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81) 541 /* LUN Not Ready - Storage firmware incompatible 542 * Manual code synchonisation required. 543 * 544 * Nothing we can do here. Try to bypass the path. 545 */ 546 return SUCCESS; 547 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1) 548 /* LUN Not Ready - Quiescense in progress 549 * 550 * Just retry and wait. 551 */ 552 return ADD_TO_MLQUEUE; 553 break; 554 case ILLEGAL_REQUEST: 555 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) { 556 /* Invalid Request - Current Logical Unit Ownership. 557 * Controller is not the current owner of the LUN, 558 * Fail the path, so that the other path be used. 559 */ 560 h->state = RDAC_STATE_PASSIVE; 561 return SUCCESS; 562 } 563 break; 564 case UNIT_ATTENTION: 565 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) 566 /* 567 * Power On, Reset, or Bus Device Reset, just retry. 568 */ 569 return ADD_TO_MLQUEUE; 570 break; 571 } 572 /* success just means we do not care what scsi-ml does */ 573 return SCSI_RETURN_NOT_HANDLED; 574 } 575 576 static const struct scsi_dh_devlist rdac_dev_list[] = { 577 {"IBM", "1722"}, 578 {"IBM", "1724"}, 579 {"IBM", "1726"}, 580 {"IBM", "1742"}, 581 {"IBM", "1814"}, 582 {"IBM", "1815"}, 583 {"IBM", "1818"}, 584 {"IBM", "3526"}, 585 {"SGI", "TP9400"}, 586 {"SGI", "TP9500"}, 587 {"SGI", "IS"}, 588 {"STK", "OPENstorage D280"}, 589 {"SUN", "CSM200_R"}, 590 {"SUN", "LCSM100_F"}, 591 {"DELL", "MD3000"}, 592 {"DELL", "MD3000i"}, 593 {NULL, NULL}, 594 }; 595 596 static int rdac_bus_attach(struct scsi_device *sdev); 597 static void rdac_bus_detach(struct scsi_device *sdev); 598 599 static struct scsi_device_handler rdac_dh = { 600 .name = RDAC_NAME, 601 .module = THIS_MODULE, 602 .devlist = rdac_dev_list, 603 .prep_fn = rdac_prep_fn, 604 .check_sense = rdac_check_sense, 605 .attach = rdac_bus_attach, 606 .detach = rdac_bus_detach, 607 .activate = rdac_activate, 608 }; 609 610 static int rdac_bus_attach(struct scsi_device *sdev) 611 { 612 struct scsi_dh_data *scsi_dh_data; 613 struct rdac_dh_data *h; 614 unsigned long flags; 615 int err; 616 617 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *) 618 + sizeof(*h) , GFP_KERNEL); 619 if (!scsi_dh_data) { 620 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", 621 RDAC_NAME); 622 return 0; 623 } 624 625 scsi_dh_data->scsi_dh = &rdac_dh; 626 h = (struct rdac_dh_data *) scsi_dh_data->buf; 627 h->lun = UNINITIALIZED_LUN; 628 h->state = RDAC_STATE_ACTIVE; 629 630 err = get_lun(sdev, h); 631 if (err != SCSI_DH_OK) 632 goto failed; 633 634 err = check_ownership(sdev, h); 635 if (err != SCSI_DH_OK) 636 goto failed; 637 638 if (!try_module_get(THIS_MODULE)) 639 goto failed; 640 641 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 642 sdev->scsi_dh_data = scsi_dh_data; 643 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 644 645 sdev_printk(KERN_NOTICE, sdev, 646 "%s: LUN %d (%s)\n", 647 RDAC_NAME, h->lun, lun_state[(int)h->lun_state]); 648 649 return 0; 650 651 failed: 652 kfree(scsi_dh_data); 653 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", 654 RDAC_NAME); 655 return -EINVAL; 656 } 657 658 static void rdac_bus_detach( struct scsi_device *sdev ) 659 { 660 struct scsi_dh_data *scsi_dh_data; 661 struct rdac_dh_data *h; 662 unsigned long flags; 663 664 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 665 scsi_dh_data = sdev->scsi_dh_data; 666 sdev->scsi_dh_data = NULL; 667 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 668 669 h = (struct rdac_dh_data *) scsi_dh_data->buf; 670 if (h->ctlr) 671 kref_put(&h->ctlr->kref, release_controller); 672 kfree(scsi_dh_data); 673 module_put(THIS_MODULE); 674 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME); 675 } 676 677 678 679 static int __init rdac_init(void) 680 { 681 int r; 682 683 r = scsi_register_device_handler(&rdac_dh); 684 if (r != 0) 685 printk(KERN_ERR "Failed to register scsi device handler."); 686 return r; 687 } 688 689 static void __exit rdac_exit(void) 690 { 691 scsi_unregister_device_handler(&rdac_dh); 692 } 693 694 module_init(rdac_init); 695 module_exit(rdac_exit); 696 697 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver"); 698 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman"); 699 MODULE_LICENSE("GPL"); 700