drivers/scsi/device_handler/scsi_dh_rdac.c

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