linux/drivers/scsi/device_handler/scsi_dh_rdac.c
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   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
  57struct rdac_mode_6_hdr {
  58        u8      data_len;
  59        u8      medium_type;
  60        u8      device_params;
  61        u8      block_desc_len;
  62};
  63
  64struct 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
  72struct 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
  81struct 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
  93struct 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
 104struct 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
 119struct 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
 131struct rdac_controller {
 132        u8                      subsys_id[SUBSYS_ID_LEN];
 133        u8                      slot_id[SLOT_ID_LEN];
 134        int                     use_ms10;
 135        struct kref             kref;
 136        struct list_head        node; /* list of all controllers */
 137        union                   {
 138                struct rdac_pg_legacy legacy;
 139                struct rdac_pg_expanded expanded;
 140        } mode_select;
 141        u8      index;
 142        u8      array_name[ARRAY_LABEL_LEN];
 143        spinlock_t              ms_lock;
 144        int                     ms_queued;
 145        struct work_struct      ms_work;
 146        struct scsi_device      *ms_sdev;
 147        struct list_head        ms_head;
 148};
 149
 150struct c8_inquiry {
 151        u8      peripheral_info;
 152        u8      page_code; /* 0xC8 */
 153        u8      reserved1;
 154        u8      page_len;
 155        u8      page_id[4]; /* "edid" */
 156        u8      reserved2[3];
 157        u8      vol_uniq_id_len;
 158        u8      vol_uniq_id[16];
 159        u8      vol_user_label_len;
 160        u8      vol_user_label[60];
 161        u8      array_uniq_id_len;
 162        u8      array_unique_id[16];
 163        u8      array_user_label_len;
 164        u8      array_user_label[60];
 165        u8      lun[8];
 166};
 167
 168struct c2_inquiry {
 169        u8      peripheral_info;
 170        u8      page_code;      /* 0xC2 */
 171        u8      reserved1;
 172        u8      page_len;
 173        u8      page_id[4];     /* "swr4" */
 174        u8      sw_version[3];
 175        u8      sw_date[3];
 176        u8      features_enabled;
 177        u8      max_lun_supported;
 178        u8      partitions[239]; /* Total allocation length should be 0xFF */
 179};
 180
 181struct rdac_dh_data {
 182        struct rdac_controller  *ctlr;
 183#define UNINITIALIZED_LUN       (1 << 8)
 184        unsigned                lun;
 185#define RDAC_STATE_ACTIVE       0
 186#define RDAC_STATE_PASSIVE      1
 187        unsigned char           state;
 188
 189#define RDAC_LUN_UNOWNED        0
 190#define RDAC_LUN_OWNED          1
 191#define RDAC_LUN_AVT            2
 192        char                    lun_state;
 193        unsigned char           sense[SCSI_SENSE_BUFFERSIZE];
 194        union                   {
 195                struct c2_inquiry c2;
 196                struct c4_inquiry c4;
 197                struct c8_inquiry c8;
 198                struct c9_inquiry c9;
 199        } inq;
 200};
 201
 202static const char *lun_state[] =
 203{
 204        "unowned",
 205        "owned",
 206        "owned (AVT mode)",
 207};
 208
 209struct rdac_queue_data {
 210        struct list_head        entry;
 211        struct rdac_dh_data     *h;
 212        activate_complete       callback_fn;
 213        void                    *callback_data;
 214};
 215
 216static LIST_HEAD(ctlr_list);
 217static DEFINE_SPINLOCK(list_lock);
 218static struct workqueue_struct *kmpath_rdacd;
 219static void send_mode_select(struct work_struct *work);
 220
 221/*
 222 * module parameter to enable rdac debug logging.
 223 * 2 bits for each type of logging, only two types defined for now
 224 * Can be enhanced if required at later point
 225 */
 226static int rdac_logging = 1;
 227module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 228MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
 229                "Default is 1 - failover logging enabled, "
 230                "set it to 0xF to enable all the logs");
 231
 232#define RDAC_LOG_FAILOVER       0
 233#define RDAC_LOG_SENSE          2
 234
 235#define RDAC_LOG_BITS           2
 236
 237#define RDAC_LOG_LEVEL(SHIFT)  \
 238        ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
 239
 240#define RDAC_LOG(SHIFT, sdev, f, arg...) \
 241do { \
 242        if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 243                sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 244} while (0);
 245
 246static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
 247{
 248        struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
 249        BUG_ON(scsi_dh_data == NULL);
 250        return ((struct rdac_dh_data *) scsi_dh_data->buf);
 251}
 252
 253static struct request *get_rdac_req(struct scsi_device *sdev,
 254                        void *buffer, unsigned buflen, int rw)
 255{
 256        struct request *rq;
 257        struct request_queue *q = sdev->request_queue;
 258
 259        rq = blk_get_request(q, rw, GFP_NOIO);
 260
 261        if (!rq) {
 262                sdev_printk(KERN_INFO, sdev,
 263                                "get_rdac_req: blk_get_request failed.\n");
 264                return NULL;
 265        }
 266
 267        if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
 268                blk_put_request(rq);
 269                sdev_printk(KERN_INFO, sdev,
 270                                "get_rdac_req: blk_rq_map_kern failed.\n");
 271                return NULL;
 272        }
 273
 274        rq->cmd_type = REQ_TYPE_BLOCK_PC;
 275        rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 276                         REQ_FAILFAST_DRIVER;
 277        rq->retries = RDAC_RETRIES;
 278        rq->timeout = RDAC_TIMEOUT;
 279
 280        return rq;
 281}
 282
 283static struct request *rdac_failover_get(struct scsi_device *sdev,
 284                                         struct rdac_dh_data *h)
 285{
 286        struct request *rq;
 287        struct rdac_mode_common *common;
 288        unsigned data_size;
 289
 290        if (h->ctlr->use_ms10) {
 291                struct rdac_pg_expanded *rdac_pg;
 292
 293                data_size = sizeof(struct rdac_pg_expanded);
 294                rdac_pg = &h->ctlr->mode_select.expanded;
 295                memset(rdac_pg, 0, data_size);
 296                common = &rdac_pg->common;
 297                rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 298                rdac_pg->subpage_code = 0x1;
 299                rdac_pg->page_len[0] = 0x01;
 300                rdac_pg->page_len[1] = 0x28;
 301        } else {
 302                struct rdac_pg_legacy *rdac_pg;
 303
 304                data_size = sizeof(struct rdac_pg_legacy);
 305                rdac_pg = &h->ctlr->mode_select.legacy;
 306                memset(rdac_pg, 0, data_size);
 307                common = &rdac_pg->common;
 308                rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 309                rdac_pg->page_len = 0x68;
 310        }
 311        common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 312        common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 313        common->rdac_options = RDAC_FORCED_QUIESENCE;
 314
 315        /* get request for block layer packet command */
 316        rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
 317        if (!rq)
 318                return NULL;
 319
 320        /* Prepare the command. */
 321        if (h->ctlr->use_ms10) {
 322                rq->cmd[0] = MODE_SELECT_10;
 323                rq->cmd[7] = data_size >> 8;
 324                rq->cmd[8] = data_size & 0xff;
 325        } else {
 326                rq->cmd[0] = MODE_SELECT;
 327                rq->cmd[4] = data_size;
 328        }
 329        rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
 330
 331        rq->sense = h->sense;
 332        memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 333        rq->sense_len = 0;
 334
 335        return rq;
 336}
 337
 338static void release_controller(struct kref *kref)
 339{
 340        struct rdac_controller *ctlr;
 341        ctlr = container_of(kref, struct rdac_controller, kref);
 342
 343        flush_workqueue(kmpath_rdacd);
 344        spin_lock(&list_lock);
 345        list_del(&ctlr->node);
 346        spin_unlock(&list_lock);
 347        kfree(ctlr);
 348}
 349
 350static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id,
 351                                                char *array_name)
 352{
 353        struct rdac_controller *ctlr, *tmp;
 354
 355        spin_lock(&list_lock);
 356
 357        list_for_each_entry(tmp, &ctlr_list, node) {
 358                if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) &&
 359                          (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
 360                        kref_get(&tmp->kref);
 361                        spin_unlock(&list_lock);
 362                        return tmp;
 363                }
 364        }
 365        ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 366        if (!ctlr)
 367                goto done;
 368
 369        /* initialize fields of controller */
 370        memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
 371        memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
 372        memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 373
 374        /* update the controller index */
 375        if (slot_id[1] == 0x31)
 376                ctlr->index = 0;
 377        else
 378                ctlr->index = 1;
 379
 380        kref_init(&ctlr->kref);
 381        ctlr->use_ms10 = -1;
 382        ctlr->ms_queued = 0;
 383        ctlr->ms_sdev = NULL;
 384        spin_lock_init(&ctlr->ms_lock);
 385        INIT_WORK(&ctlr->ms_work, send_mode_select);
 386        INIT_LIST_HEAD(&ctlr->ms_head);
 387        list_add(&ctlr->node, &ctlr_list);
 388done:
 389        spin_unlock(&list_lock);
 390        return ctlr;
 391}
 392
 393static int submit_inquiry(struct scsi_device *sdev, int page_code,
 394                          unsigned int len, struct rdac_dh_data *h)
 395{
 396        struct request *rq;
 397        struct request_queue *q = sdev->request_queue;
 398        int err = SCSI_DH_RES_TEMP_UNAVAIL;
 399
 400        rq = get_rdac_req(sdev, &h->inq, len, READ);
 401        if (!rq)
 402                goto done;
 403
 404        /* Prepare the command. */
 405        rq->cmd[0] = INQUIRY;
 406        rq->cmd[1] = 1;
 407        rq->cmd[2] = page_code;
 408        rq->cmd[4] = len;
 409        rq->cmd_len = COMMAND_SIZE(INQUIRY);
 410
 411        rq->sense = h->sense;
 412        memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 413        rq->sense_len = 0;
 414
 415        err = blk_execute_rq(q, NULL, rq, 1);
 416        if (err == -EIO)
 417                err = SCSI_DH_IO;
 418
 419        blk_put_request(rq);
 420done:
 421        return err;
 422}
 423
 424static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 425                        char *array_name)
 426{
 427        int err, i;
 428        struct c8_inquiry *inqp;
 429
 430        err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
 431        if (err == SCSI_DH_OK) {
 432                inqp = &h->inq.c8;
 433                if (inqp->page_code != 0xc8)
 434                        return SCSI_DH_NOSYS;
 435                if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 436                    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 437                        return SCSI_DH_NOSYS;
 438                h->lun = inqp->lun[7]; /* Uses only the last byte */
 439
 440                for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 441                        *(array_name+i) = inqp->array_user_label[(2*i)+1];
 442
 443                *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 444        }
 445        return err;
 446}
 447
 448static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 449{
 450        int err;
 451        struct c9_inquiry *inqp;
 452
 453        h->lun_state = RDAC_LUN_UNOWNED;
 454        h->state = RDAC_STATE_ACTIVE;
 455        err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
 456        if (err == SCSI_DH_OK) {
 457                inqp = &h->inq.c9;
 458                if ((inqp->avte_cvp >> 7) == 0x1) {
 459                        /* LUN in AVT mode */
 460                        sdev_printk(KERN_NOTICE, sdev,
 461                                    "%s: AVT mode detected\n",
 462                                    RDAC_NAME);
 463                        h->lun_state = RDAC_LUN_AVT;
 464                } else if ((inqp->avte_cvp & 0x1) != 0) {
 465                        /* LUN was owned by the controller */
 466                        h->lun_state = RDAC_LUN_OWNED;
 467                }
 468        }
 469
 470        if (h->lun_state == RDAC_LUN_UNOWNED)
 471                h->state = RDAC_STATE_PASSIVE;
 472
 473        return err;
 474}
 475
 476static int initialize_controller(struct scsi_device *sdev,
 477                                 struct rdac_dh_data *h, char *array_name)
 478{
 479        int err;
 480        struct c4_inquiry *inqp;
 481
 482        err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
 483        if (err == SCSI_DH_OK) {
 484                inqp = &h->inq.c4;
 485                h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id,
 486                                        array_name);
 487                if (!h->ctlr)
 488                        err = SCSI_DH_RES_TEMP_UNAVAIL;
 489        }
 490        return err;
 491}
 492
 493static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 494{
 495        int err;
 496        struct c2_inquiry *inqp;
 497
 498        err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
 499        if (err == SCSI_DH_OK) {
 500                inqp = &h->inq.c2;
 501                /*
 502                 * If more than MODE6_MAX_LUN luns are supported, use
 503                 * mode select 10
 504                 */
 505                if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 506                        h->ctlr->use_ms10 = 1;
 507                else
 508                        h->ctlr->use_ms10 = 0;
 509        }
 510        return err;
 511}
 512
 513static int mode_select_handle_sense(struct scsi_device *sdev,
 514                                        unsigned char *sensebuf)
 515{
 516        struct scsi_sense_hdr sense_hdr;
 517        int err = SCSI_DH_IO, ret;
 518        struct rdac_dh_data *h = get_rdac_data(sdev);
 519
 520        ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 521        if (!ret)
 522                goto done;
 523
 524        switch (sense_hdr.sense_key) {
 525        case NO_SENSE:
 526        case ABORTED_COMMAND:
 527        case UNIT_ATTENTION:
 528                err = SCSI_DH_RETRY;
 529                break;
 530        case NOT_READY:
 531                if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
 532                        /* LUN Not Ready and is in the Process of Becoming
 533                         * Ready
 534                         */
 535                        err = SCSI_DH_RETRY;
 536                break;
 537        case ILLEGAL_REQUEST:
 538                if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
 539                        /*
 540                         * Command Lock contention
 541                         */
 542                        err = SCSI_DH_RETRY;
 543                break;
 544        default:
 545                break;
 546        }
 547
 548        RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 549                "MODE_SELECT returned with sense %02x/%02x/%02x",
 550                (char *) h->ctlr->array_name, h->ctlr->index,
 551                sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
 552
 553done:
 554        return err;
 555}
 556
 557static void send_mode_select(struct work_struct *work)
 558{
 559        struct rdac_controller *ctlr =
 560                container_of(work, struct rdac_controller, ms_work);
 561        struct request *rq;
 562        struct scsi_device *sdev = ctlr->ms_sdev;
 563        struct rdac_dh_data *h = get_rdac_data(sdev);
 564        struct request_queue *q = sdev->request_queue;
 565        int err, retry_cnt = RDAC_RETRY_COUNT;
 566        struct rdac_queue_data *tmp, *qdata;
 567        LIST_HEAD(list);
 568        u8 *lun_table;
 569
 570        spin_lock(&ctlr->ms_lock);
 571        list_splice_init(&ctlr->ms_head, &list);
 572        ctlr->ms_queued = 0;
 573        ctlr->ms_sdev = NULL;
 574        spin_unlock(&ctlr->ms_lock);
 575
 576        if (ctlr->use_ms10)
 577                lun_table = ctlr->mode_select.expanded.lun_table;
 578        else
 579                lun_table = ctlr->mode_select.legacy.lun_table;
 580
 581retry:
 582        err = SCSI_DH_RES_TEMP_UNAVAIL;
 583        rq = rdac_failover_get(sdev, h);
 584        if (!rq)
 585                goto done;
 586
 587        list_for_each_entry(qdata, &list, entry) {
 588                lun_table[qdata->h->lun] = 0x81;
 589        }
 590
 591        RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 592                "%s MODE_SELECT command",
 593                (char *) h->ctlr->array_name, h->ctlr->index,
 594                (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 595
 596        err = blk_execute_rq(q, NULL, rq, 1);
 597        blk_put_request(rq);
 598        if (err != SCSI_DH_OK) {
 599                err = mode_select_handle_sense(sdev, h->sense);
 600                if (err == SCSI_DH_RETRY && retry_cnt--)
 601                        goto retry;
 602        }
 603        if (err == SCSI_DH_OK) {
 604                h->state = RDAC_STATE_ACTIVE;
 605                RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 606                                "MODE_SELECT completed",
 607                                (char *) h->ctlr->array_name, h->ctlr->index);
 608        }
 609
 610done:
 611        list_for_each_entry_safe(qdata, tmp, &list, entry) {
 612                list_del(&qdata->entry);
 613                if (err == SCSI_DH_OK)
 614                        qdata->h->state = RDAC_STATE_ACTIVE;
 615                if (qdata->callback_fn)
 616                        qdata->callback_fn(qdata->callback_data, err);
 617                kfree(qdata);
 618        }
 619        return;
 620}
 621
 622static int queue_mode_select(struct scsi_device *sdev,
 623                                activate_complete fn, void *data)
 624{
 625        struct rdac_queue_data *qdata;
 626        struct rdac_controller *ctlr;
 627
 628        qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 629        if (!qdata)
 630                return SCSI_DH_RETRY;
 631
 632        qdata->h = get_rdac_data(sdev);
 633        qdata->callback_fn = fn;
 634        qdata->callback_data = data;
 635
 636        ctlr = qdata->h->ctlr;
 637        spin_lock(&ctlr->ms_lock);
 638        list_add_tail(&qdata->entry, &ctlr->ms_head);
 639        if (!ctlr->ms_queued) {
 640                ctlr->ms_queued = 1;
 641                ctlr->ms_sdev = sdev;
 642                queue_work(kmpath_rdacd, &ctlr->ms_work);
 643        }
 644        spin_unlock(&ctlr->ms_lock);
 645        return SCSI_DH_OK;
 646}
 647
 648static int rdac_activate(struct scsi_device *sdev,
 649                        activate_complete fn, void *data)
 650{
 651        struct rdac_dh_data *h = get_rdac_data(sdev);
 652        int err = SCSI_DH_OK;
 653
 654        err = check_ownership(sdev, h);
 655        if (err != SCSI_DH_OK)
 656                goto done;
 657
 658        if (h->lun_state == RDAC_LUN_UNOWNED) {
 659                err = queue_mode_select(sdev, fn, data);
 660                if (err == SCSI_DH_OK)
 661                        return 0;
 662        }
 663done:
 664        if (fn)
 665                fn(data, err);
 666        return 0;
 667}
 668
 669static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 670{
 671        struct rdac_dh_data *h = get_rdac_data(sdev);
 672        int ret = BLKPREP_OK;
 673
 674        if (h->state != RDAC_STATE_ACTIVE) {
 675                ret = BLKPREP_KILL;
 676                req->cmd_flags |= REQ_QUIET;
 677        }
 678        return ret;
 679
 680}
 681
 682static int rdac_check_sense(struct scsi_device *sdev,
 683                                struct scsi_sense_hdr *sense_hdr)
 684{
 685        struct rdac_dh_data *h = get_rdac_data(sdev);
 686
 687        RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 688                        "I/O returned with sense %02x/%02x/%02x",
 689                        (char *) h->ctlr->array_name, h->ctlr->index,
 690                        sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 691
 692        switch (sense_hdr->sense_key) {
 693        case NOT_READY:
 694                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 695                        /* LUN Not Ready - Logical Unit Not Ready and is in
 696                        * the process of becoming ready
 697                        * Just retry.
 698                        */
 699                        return ADD_TO_MLQUEUE;
 700                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 701                        /* LUN Not Ready - Storage firmware incompatible
 702                         * Manual code synchonisation required.
 703                         *
 704                         * Nothing we can do here. Try to bypass the path.
 705                         */
 706                        return SUCCESS;
 707                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 708                        /* LUN Not Ready - Quiescense in progress
 709                         *
 710                         * Just retry and wait.
 711                         */
 712                        return ADD_TO_MLQUEUE;
 713                if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 714                        /* LUN Not Ready - Quiescense in progress
 715                         * or has been achieved
 716                         * Just retry.
 717                         */
 718                        return ADD_TO_MLQUEUE;
 719                break;
 720        case ILLEGAL_REQUEST:
 721                if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 722                        /* Invalid Request - Current Logical Unit Ownership.
 723                         * Controller is not the current owner of the LUN,
 724                         * Fail the path, so that the other path be used.
 725                         */
 726                        h->state = RDAC_STATE_PASSIVE;
 727                        return SUCCESS;
 728                }
 729                break;
 730        case UNIT_ATTENTION:
 731                if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 732                        /*
 733                         * Power On, Reset, or Bus Device Reset, just retry.
 734                         */
 735                        return ADD_TO_MLQUEUE;
 736                if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 737                        /*
 738                         * Quiescence in progress , just retry.
 739                         */
 740                        return ADD_TO_MLQUEUE;
 741                break;
 742        }
 743        /* success just means we do not care what scsi-ml does */
 744        return SCSI_RETURN_NOT_HANDLED;
 745}
 746
 747static const struct scsi_dh_devlist rdac_dev_list[] = {
 748        {"IBM", "1722"},
 749        {"IBM", "1724"},
 750        {"IBM", "1726"},
 751        {"IBM", "1742"},
 752        {"IBM", "1745"},
 753        {"IBM", "1746"},
 754        {"IBM", "1814"},
 755        {"IBM", "1815"},
 756        {"IBM", "1818"},
 757        {"IBM", "3526"},
 758        {"SGI", "TP9400"},
 759        {"SGI", "TP9500"},
 760        {"SGI", "IS"},
 761        {"STK", "OPENstorage D280"},
 762        {"SUN", "CSM200_R"},
 763        {"SUN", "LCSM100_I"},
 764        {"SUN", "LCSM100_S"},
 765        {"SUN", "LCSM100_E"},
 766        {"SUN", "LCSM100_F"},
 767        {"DELL", "MD3000"},
 768        {"DELL", "MD3000i"},
 769        {"DELL", "MD32xx"},
 770        {"DELL", "MD32xxi"},
 771        {"DELL", "MD36xxi"},
 772        {"LSI", "INF-01-00"},
 773        {"ENGENIO", "INF-01-00"},
 774        {"STK", "FLEXLINE 380"},
 775        {"SUN", "CSM100_R_FC"},
 776        {"SUN", "STK6580_6780"},
 777        {"SUN", "SUN_6180"},
 778        {NULL, NULL},
 779};
 780
 781static int rdac_bus_attach(struct scsi_device *sdev);
 782static void rdac_bus_detach(struct scsi_device *sdev);
 783
 784static struct scsi_device_handler rdac_dh = {
 785        .name = RDAC_NAME,
 786        .module = THIS_MODULE,
 787        .devlist = rdac_dev_list,
 788        .prep_fn = rdac_prep_fn,
 789        .check_sense = rdac_check_sense,
 790        .attach = rdac_bus_attach,
 791        .detach = rdac_bus_detach,
 792        .activate = rdac_activate,
 793};
 794
 795static int rdac_bus_attach(struct scsi_device *sdev)
 796{
 797        struct scsi_dh_data *scsi_dh_data;
 798        struct rdac_dh_data *h;
 799        unsigned long flags;
 800        int err;
 801        char array_name[ARRAY_LABEL_LEN];
 802
 803        scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
 804                               + sizeof(*h) , GFP_KERNEL);
 805        if (!scsi_dh_data) {
 806                sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
 807                            RDAC_NAME);
 808                return 0;
 809        }
 810
 811        scsi_dh_data->scsi_dh = &rdac_dh;
 812        h = (struct rdac_dh_data *) scsi_dh_data->buf;
 813        h->lun = UNINITIALIZED_LUN;
 814        h->state = RDAC_STATE_ACTIVE;
 815
 816        err = get_lun_info(sdev, h, array_name);
 817        if (err != SCSI_DH_OK)
 818                goto failed;
 819
 820        err = initialize_controller(sdev, h, array_name);
 821        if (err != SCSI_DH_OK)
 822                goto failed;
 823
 824        err = check_ownership(sdev, h);
 825        if (err != SCSI_DH_OK)
 826                goto clean_ctlr;
 827
 828        err = set_mode_select(sdev, h);
 829        if (err != SCSI_DH_OK)
 830                goto clean_ctlr;
 831
 832        if (!try_module_get(THIS_MODULE))
 833                goto clean_ctlr;
 834
 835        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 836        sdev->scsi_dh_data = scsi_dh_data;
 837        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 838
 839        sdev_printk(KERN_NOTICE, sdev,
 840                    "%s: LUN %d (%s)\n",
 841                    RDAC_NAME, h->lun, lun_state[(int)h->lun_state]);
 842
 843        return 0;
 844
 845clean_ctlr:
 846        kref_put(&h->ctlr->kref, release_controller);
 847
 848failed:
 849        kfree(scsi_dh_data);
 850        sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
 851                    RDAC_NAME);
 852        return -EINVAL;
 853}
 854
 855static void rdac_bus_detach( struct scsi_device *sdev )
 856{
 857        struct scsi_dh_data *scsi_dh_data;
 858        struct rdac_dh_data *h;
 859        unsigned long flags;
 860
 861        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 862        scsi_dh_data = sdev->scsi_dh_data;
 863        sdev->scsi_dh_data = NULL;
 864        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 865
 866        h = (struct rdac_dh_data *) scsi_dh_data->buf;
 867        if (h->ctlr)
 868                kref_put(&h->ctlr->kref, release_controller);
 869        kfree(scsi_dh_data);
 870        module_put(THIS_MODULE);
 871        sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
 872}
 873
 874
 875
 876static int __init rdac_init(void)
 877{
 878        int r;
 879
 880        r = scsi_register_device_handler(&rdac_dh);
 881        if (r != 0) {
 882                printk(KERN_ERR "Failed to register scsi device handler.");
 883                goto done;
 884        }
 885
 886        /*
 887         * Create workqueue to handle mode selects for rdac
 888         */
 889        kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 890        if (!kmpath_rdacd) {
 891                scsi_unregister_device_handler(&rdac_dh);
 892                printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 893        }
 894done:
 895        return r;
 896}
 897
 898static void __exit rdac_exit(void)
 899{
 900        destroy_workqueue(kmpath_rdacd);
 901        scsi_unregister_device_handler(&rdac_dh);
 902}
 903
 904module_init(rdac_init);
 905module_exit(rdac_exit);
 906
 907MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver");
 908MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 909MODULE_LICENSE("GPL");
 910