LXR linux/drivers/scsi/device_handler/scsi_dh

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Target driver for EMC CLARiiON AX/CX-series hardware.
   4 * Based on code from Lars Marowsky-Bree <lmb@suse.de>
   5 * and Ed Goggin <egoggin@emc.com>.
   6 *
   7 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8 * Copyright (C) 2006 Mike Christie
   9 */
  10#include <linux/slab.h>
  11#include <linux/module.h>
  12#include <scsi/scsi.h>
  13#include <scsi/scsi_eh.h>
  14#include <scsi/scsi_dh.h>
  15#include <scsi/scsi_device.h>
  16
  17#define CLARIION_NAME                   "emc"
  18
  19#define CLARIION_TRESPASS_PAGE          0x22
  20#define CLARIION_BUFFER_SIZE            0xFC
  21#define CLARIION_TIMEOUT                (60 * HZ)
  22#define CLARIION_RETRIES                3
  23#define CLARIION_UNBOUND_LU             -1
  24#define CLARIION_SP_A                   0
  25#define CLARIION_SP_B                   1
  26
  27/* Flags */
  28#define CLARIION_SHORT_TRESPASS         1
  29#define CLARIION_HONOR_RESERVATIONS     2
  30
  31/* LUN states */
  32#define CLARIION_LUN_UNINITIALIZED      -1
  33#define CLARIION_LUN_UNBOUND            0
  34#define CLARIION_LUN_BOUND              1
  35#define CLARIION_LUN_OWNED              2
  36
  37static unsigned char long_trespass[] = {
  38        0, 0, 0, 0, 0, 0, 0, 0,
  39        CLARIION_TRESPASS_PAGE, /* Page code */
  40        0x09,                   /* Page length - 2 */
  41        0x01,                   /* Trespass code */
  42        0xff, 0xff,             /* Trespass target */
  43        0, 0, 0, 0, 0, 0        /* Reserved bytes / unknown */
  44};
  45
  46static unsigned char short_trespass[] = {
  47        0, 0, 0, 0,
  48        CLARIION_TRESPASS_PAGE, /* Page code */
  49        0x02,                   /* Page length - 2 */
  50        0x01,                   /* Trespass code */
  51        0xff,                   /* Trespass target */
  52};
  53
  54static const char * lun_state[] =
  55{
  56    "not bound",
  57    "bound",
  58    "owned",
  59};
  60
  61struct clariion_dh_data {
  62        /*
  63         * Flags:
  64         *  CLARIION_SHORT_TRESPASS
  65         * Use short trespass command (FC-series) or the long version
  66         * (default for AX/CX CLARiiON arrays).
  67         *
  68         *  CLARIION_HONOR_RESERVATIONS
  69         * Whether or not (default) to honor SCSI reservations when
  70         * initiating a switch-over.
  71         */
  72        unsigned flags;
  73        /*
  74         * I/O buffer for both MODE_SELECT and INQUIRY commands.
  75         */
  76        unsigned char buffer[CLARIION_BUFFER_SIZE];
  77        /*
  78         * LUN state
  79         */
  80        int lun_state;
  81        /*
  82         * SP Port number
  83         */
  84        int port;
  85        /*
  86         * which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
  87         * path's mapped LUN
  88         */
  89        int default_sp;
  90        /*
  91         * which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
  92         * path's mapped LUN
  93         */
  94        int current_sp;
  95};
  96
  97/*
  98 * Parse MODE_SELECT cmd reply.
  99 */
 100static int trespass_endio(struct scsi_device *sdev,
 101                          struct scsi_sense_hdr *sshdr)
 102{
 103        int err = SCSI_DH_IO;
 104
 105        sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
 106                    "0x%2x, 0x%2x while sending CLARiiON trespass "
 107                    "command.\n", CLARIION_NAME, sshdr->sense_key,
 108                    sshdr->asc, sshdr->ascq);
 109
 110        if (sshdr->sense_key == 0x05 && sshdr->asc == 0x04 &&
 111            sshdr->ascq == 0x00) {
 112                /*
 113                 * Array based copy in progress -- do not send
 114                 * mode_select or copy will be aborted mid-stream.
 115                 */
 116                sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
 117                            "progress while sending CLARiiON trespass "
 118                            "command.\n", CLARIION_NAME);
 119                err = SCSI_DH_DEV_TEMP_BUSY;
 120        } else if (sshdr->sense_key == 0x02 && sshdr->asc == 0x04 &&
 121                   sshdr->ascq == 0x03) {
 122                /*
 123                 * LUN Not Ready - Manual Intervention Required
 124                 * indicates in-progress ucode upgrade (NDU).
 125                 */
 126                sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
 127                            "ucode upgrade NDU operation while sending "
 128                            "CLARiiON trespass command.\n", CLARIION_NAME);
 129                err = SCSI_DH_DEV_TEMP_BUSY;
 130        } else
 131                err = SCSI_DH_DEV_FAILED;
 132        return err;
 133}
 134
 135static int parse_sp_info_reply(struct scsi_device *sdev,
 136                               struct clariion_dh_data *csdev)
 137{
 138        int err = SCSI_DH_OK;
 139
 140        /* check for in-progress ucode upgrade (NDU) */
 141        if (csdev->buffer[48] != 0) {
 142                sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
 143                            "ucode upgrade NDU operation while finding "
 144                            "current active SP.", CLARIION_NAME);
 145                err = SCSI_DH_DEV_TEMP_BUSY;
 146                goto out;
 147        }
 148        if (csdev->buffer[4] > 2) {
 149                /* Invalid buffer format */
 150                sdev_printk(KERN_NOTICE, sdev,
 151                            "%s: invalid VPD page 0xC0 format\n",
 152                            CLARIION_NAME);
 153                err = SCSI_DH_NOSYS;
 154                goto out;
 155        }
 156        switch (csdev->buffer[28] & 0x0f) {
 157        case 6:
 158                sdev_printk(KERN_NOTICE, sdev,
 159                            "%s: ALUA failover mode detected\n",
 160                            CLARIION_NAME);
 161                break;
 162        case 4:
 163                /* Linux failover */
 164                break;
 165        default:
 166                sdev_printk(KERN_WARNING, sdev,
 167                            "%s: Invalid failover mode %d\n",
 168                            CLARIION_NAME, csdev->buffer[28] & 0x0f);
 169                err = SCSI_DH_NOSYS;
 170                goto out;
 171        }
 172
 173        csdev->default_sp = csdev->buffer[5];
 174        csdev->lun_state = csdev->buffer[4];
 175        csdev->current_sp = csdev->buffer[8];
 176        csdev->port = csdev->buffer[7];
 177        if (csdev->lun_state == CLARIION_LUN_OWNED)
 178                sdev->access_state = SCSI_ACCESS_STATE_OPTIMAL;
 179        else
 180                sdev->access_state = SCSI_ACCESS_STATE_STANDBY;
 181        if (csdev->default_sp == csdev->current_sp)
 182                sdev->access_state |= SCSI_ACCESS_STATE_PREFERRED;
 183out:
 184        return err;
 185}
 186
 187#define emc_default_str "FC (Legacy)"
 188
 189static char * parse_sp_model(struct scsi_device *sdev, unsigned char *buffer)
 190{
 191        unsigned char len = buffer[4] + 5;
 192        char *sp_model = NULL;
 193        unsigned char sp_len, serial_len;
 194
 195        if (len < 160) {
 196                sdev_printk(KERN_WARNING, sdev,
 197                            "%s: Invalid information section length %d\n",
 198                            CLARIION_NAME, len);
 199                /* Check for old FC arrays */
 200                if (!strncmp(buffer + 8, "DGC", 3)) {
 201                        /* Old FC array, not supporting extended information */
 202                        sp_model = emc_default_str;
 203                }
 204                goto out;
 205        }
 206
 207        /*
 208         * Parse extended information for SP model number
 209         */
 210        serial_len = buffer[160];
 211        if (serial_len == 0 || serial_len + 161 > len) {
 212                sdev_printk(KERN_WARNING, sdev,
 213                            "%s: Invalid array serial number length %d\n",
 214                            CLARIION_NAME, serial_len);
 215                goto out;
 216        }
 217        sp_len = buffer[99];
 218        if (sp_len == 0 || serial_len + sp_len + 161 > len) {
 219                sdev_printk(KERN_WARNING, sdev,
 220                            "%s: Invalid model number length %d\n",
 221                            CLARIION_NAME, sp_len);
 222                goto out;
 223        }
 224        sp_model = &buffer[serial_len + 161];
 225        /* Strip whitespace at the end */
 226        while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
 227                sp_len--;
 228
 229        sp_model[sp_len] = '\0';
 230
 231out:
 232        return sp_model;
 233}
 234
 235static int send_trespass_cmd(struct scsi_device *sdev,
 236                            struct clariion_dh_data *csdev)
 237{
 238        unsigned char *page22;
 239        unsigned char cdb[MAX_COMMAND_SIZE];
 240        int err, res = SCSI_DH_OK, len;
 241        struct scsi_sense_hdr sshdr;
 242        u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 243                REQ_FAILFAST_DRIVER;
 244
 245        if (csdev->flags & CLARIION_SHORT_TRESPASS) {
 246                page22 = short_trespass;
 247                if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 248                        /* Set Honor Reservations bit */
 249                        page22[6] |= 0x80;
 250                len = sizeof(short_trespass);
 251                cdb[0] = MODE_SELECT;
 252                cdb[1] = 0x10;
 253                cdb[4] = len;
 254        } else {
 255                page22 = long_trespass;
 256                if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 257                        /* Set Honor Reservations bit */
 258                        page22[10] |= 0x80;
 259                len = sizeof(long_trespass);
 260                cdb[0] = MODE_SELECT_10;
 261                cdb[8] = len;
 262        }
 263        BUG_ON((len > CLARIION_BUFFER_SIZE));
 264        memcpy(csdev->buffer, page22, len);
 265
 266        err = scsi_execute(sdev, cdb, DMA_TO_DEVICE, csdev->buffer, len, NULL,
 267                        &sshdr, CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
 268                        req_flags, 0, NULL);
 269        if (err) {
 270                if (scsi_sense_valid(&sshdr))
 271                        res = trespass_endio(sdev, &sshdr);
 272                else {
 273                        sdev_printk(KERN_INFO, sdev,
 274                                    "%s: failed to send MODE SELECT: %x\n",
 275                                    CLARIION_NAME, err);
 276                        res = SCSI_DH_IO;
 277                }
 278        }
 279
 280        return res;
 281}
 282
 283static enum scsi_disposition clariion_check_sense(struct scsi_device *sdev,
 284                                        struct scsi_sense_hdr *sense_hdr)
 285{
 286        switch (sense_hdr->sense_key) {
 287        case NOT_READY:
 288                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
 289                        /*
 290                         * LUN Not Ready - Manual Intervention Required
 291                         * indicates this is a passive path.
 292                         *
 293                         * FIXME: However, if this is seen and EVPD C0
 294                         * indicates that this is due to a NDU in
 295                         * progress, we should set FAIL_PATH too.
 296                         * This indicates we might have to do a SCSI
 297                         * inquiry in the end_io path. Ugh.
 298                         *
 299                         * Can return FAILED only when we want the error
 300                         * recovery process to kick in.
 301                         */
 302                        return SUCCESS;
 303                break;
 304        case ILLEGAL_REQUEST:
 305                if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
 306                        /*
 307                         * An array based copy is in progress. Do not
 308                         * fail the path, do not bypass to another PG,
 309                         * do not retry. Fail the IO immediately.
 310                         * (Actually this is the same conclusion as in
 311                         * the default handler, but lets make sure.)
 312                         *
 313                         * Can return FAILED only when we want the error
 314                         * recovery process to kick in.
 315                         */
 316                        return SUCCESS;
 317                break;
 318        case UNIT_ATTENTION:
 319                if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 320                        /*
 321                         * Unit Attention Code. This is the first IO
 322                         * to the new path, so just retry.
 323                         */
 324                        return ADD_TO_MLQUEUE;
 325                break;
 326        }
 327
 328        return SCSI_RETURN_NOT_HANDLED;
 329}
 330
 331static blk_status_t clariion_prep_fn(struct scsi_device *sdev,
 332                struct request *req)
 333{
 334        struct clariion_dh_data *h = sdev->handler_data;
 335
 336        if (h->lun_state != CLARIION_LUN_OWNED) {
 337                req->rq_flags |= RQF_QUIET;
 338                return BLK_STS_IOERR;
 339        }
 340
 341        return BLK_STS_OK;
 342}
 343
 344static int clariion_std_inquiry(struct scsi_device *sdev,
 345                                struct clariion_dh_data *csdev)
 346{
 347        int err = SCSI_DH_OK;
 348        char *sp_model;
 349
 350        sp_model = parse_sp_model(sdev, sdev->inquiry);
 351        if (!sp_model) {
 352                err = SCSI_DH_DEV_UNSUPP;
 353                goto out;
 354        }
 355
 356        /*
 357         * FC Series arrays do not support long trespass
 358         */
 359        if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
 360                csdev->flags |= CLARIION_SHORT_TRESPASS;
 361
 362        sdev_printk(KERN_INFO, sdev,
 363                    "%s: detected Clariion %s, flags %x\n",
 364                    CLARIION_NAME, sp_model, csdev->flags);
 365out:
 366        return err;
 367}
 368
 369static int clariion_send_inquiry(struct scsi_device *sdev,
 370                                 struct clariion_dh_data *csdev)
 371{
 372        int err = SCSI_DH_IO;
 373
 374        if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
 375                               CLARIION_BUFFER_SIZE))
 376                err = parse_sp_info_reply(sdev, csdev);
 377
 378        return err;
 379}
 380
 381static int clariion_activate(struct scsi_device *sdev,
 382                                activate_complete fn, void *data)
 383{
 384        struct clariion_dh_data *csdev = sdev->handler_data;
 385        int result;
 386
 387        result = clariion_send_inquiry(sdev, csdev);
 388        if (result != SCSI_DH_OK)
 389                goto done;
 390
 391        if (csdev->lun_state == CLARIION_LUN_OWNED)
 392                goto done;
 393
 394        result = send_trespass_cmd(sdev, csdev);
 395        if (result != SCSI_DH_OK)
 396                goto done;
 397        sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
 398                    CLARIION_NAME,
 399                    csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
 400
 401        /* Update status */
 402        result = clariion_send_inquiry(sdev, csdev);
 403        if (result != SCSI_DH_OK)
 404                goto done;
 405
 406done:
 407        sdev_printk(KERN_INFO, sdev,
 408                    "%s: at SP %c Port %d (%s, default SP %c)\n",
 409                    CLARIION_NAME, csdev->current_sp + 'A',
 410                    csdev->port, lun_state[csdev->lun_state],
 411                    csdev->default_sp + 'A');
 412
 413        if (fn)
 414                fn(data, result);
 415        return 0;
 416}
 417/*
 418 * params - parameters in the following format
 419 *      "no_of_params\0param1\0param2\0param3\0...\0"
 420 *      for example, string for 2 parameters with value 10 and 21
 421 *      is specified as "2\010\021\0".
 422 */
 423static int clariion_set_params(struct scsi_device *sdev, const char *params)
 424{
 425        struct clariion_dh_data *csdev = sdev->handler_data;
 426        unsigned int hr = 0, st = 0, argc;
 427        const char *p = params;
 428        int result = SCSI_DH_OK;
 429
 430        if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
 431                return -EINVAL;
 432
 433        while (*p++)
 434                ;
 435        if ((sscanf(p, "%u", &st) != 1) || (st > 1))
 436                return -EINVAL;
 437
 438        while (*p++)
 439                ;
 440        if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
 441                return -EINVAL;
 442
 443        if (st)
 444                csdev->flags |= CLARIION_SHORT_TRESPASS;
 445        else
 446                csdev->flags &= ~CLARIION_SHORT_TRESPASS;
 447
 448        if (hr)
 449                csdev->flags |= CLARIION_HONOR_RESERVATIONS;
 450        else
 451                csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;
 452
 453        /*
 454         * If this path is owned, we have to send a trespass command
 455         * with the new parameters. If not, simply return. Next trespass
 456         * command would use the parameters.
 457         */
 458        if (csdev->lun_state != CLARIION_LUN_OWNED)
 459                goto done;
 460
 461        csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
 462        result = send_trespass_cmd(sdev, csdev);
 463        if (result != SCSI_DH_OK)
 464                goto done;
 465
 466        /* Update status */
 467        result = clariion_send_inquiry(sdev, csdev);
 468
 469done:
 470        return result;
 471}
 472
 473static int clariion_bus_attach(struct scsi_device *sdev)
 474{
 475        struct clariion_dh_data *h;
 476        int err;
 477
 478        h = kzalloc(sizeof(*h) , GFP_KERNEL);
 479        if (!h)
 480                return SCSI_DH_NOMEM;
 481        h->lun_state = CLARIION_LUN_UNINITIALIZED;
 482        h->default_sp = CLARIION_UNBOUND_LU;
 483        h->current_sp = CLARIION_UNBOUND_LU;
 484
 485        err = clariion_std_inquiry(sdev, h);
 486        if (err != SCSI_DH_OK)
 487                goto failed;
 488
 489        err = clariion_send_inquiry(sdev, h);
 490        if (err != SCSI_DH_OK)
 491                goto failed;
 492
 493        sdev_printk(KERN_INFO, sdev,
 494                    "%s: connected to SP %c Port %d (%s, default SP %c)\n",
 495                    CLARIION_NAME, h->current_sp + 'A',
 496                    h->port, lun_state[h->lun_state],
 497                    h->default_sp + 'A');
 498
 499        sdev->handler_data = h;
 500        return SCSI_DH_OK;
 501
 502failed:
 503        kfree(h);
 504        return err;
 505}
 506
 507static void clariion_bus_detach(struct scsi_device *sdev)
 508{
 509        kfree(sdev->handler_data);
 510        sdev->handler_data = NULL;
 511}
 512
 513static struct scsi_device_handler clariion_dh = {
 514        .name           = CLARIION_NAME,
 515        .module         = THIS_MODULE,
 516        .attach         = clariion_bus_attach,
 517        .detach         = clariion_bus_detach,
 518        .check_sense    = clariion_check_sense,
 519        .activate       = clariion_activate,
 520        .prep_fn        = clariion_prep_fn,
 521        .set_params     = clariion_set_params,
 522};
 523
 524static int __init clariion_init(void)
 525{
 526        int r;
 527
 528        r = scsi_register_device_handler(&clariion_dh);
 529        if (r != 0)
 530                printk(KERN_ERR "%s: Failed to register scsi device handler.",
 531                        CLARIION_NAME);
 532        return r;
 533}
 534
 535static void __exit clariion_exit(void)
 536{
 537        scsi_unregister_device_handler(&clariion_dh);
 538}
 539
 540module_init(clariion_init);
 541module_exit(clariion_exit);
 542
 543MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
 544MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
 545MODULE_LICENSE("GPL");
 546