drivers/scsi/device_handler/scsi_dh_emc.c

   1 /*
   2  * Target driver for EMC CLARiiON AX/CX-series hardware.
   3  * Based on code from Lars Marowsky-Bree <lmb@suse.de>
   4  * and Ed Goggin <egoggin@emc.com>.
   5  *
   6  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   7  * Copyright (C) 2006 Mike Christie
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2, or (at your option)
  12  * any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; see the file COPYING.  If not, write to
  21  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/scsi_eh.h>
  27 #include <scsi/scsi_dh.h>
  28 #include <scsi/scsi_device.h>
  29
  30 #define CLARIION_NAME                   "emc"
  31
  32 #define CLARIION_TRESPASS_PAGE          0x22
  33 #define CLARIION_BUFFER_SIZE            0xFC
  34 #define CLARIION_TIMEOUT                (60 * HZ)
  35 #define CLARIION_RETRIES                3
  36 #define CLARIION_UNBOUND_LU             -1
  37 #define CLARIION_SP_A                   0
  38 #define CLARIION_SP_B                   1
  39
  40 /* Flags */
  41 #define CLARIION_SHORT_TRESPASS         1
  42 #define CLARIION_HONOR_RESERVATIONS     2
  43
  44 /* LUN states */
  45 #define CLARIION_LUN_UNINITIALIZED      -1
  46 #define CLARIION_LUN_UNBOUND            0
  47 #define CLARIION_LUN_BOUND              1
  48 #define CLARIION_LUN_OWNED              2
  49
  50 static unsigned char long_trespass[] = {
  51         0, 0, 0, 0, 0, 0, 0, 0,
  52         CLARIION_TRESPASS_PAGE, /* Page code */
  53         0x09,                   /* Page length - 2 */
  54         0x01,                   /* Trespass code */
  55         0xff, 0xff,             /* Trespass target */
  56         0, 0, 0, 0, 0, 0        /* Reserved bytes / unknown */
  57 };
  58
  59 static unsigned char short_trespass[] = {
  60         0, 0, 0, 0,
  61         CLARIION_TRESPASS_PAGE, /* Page code */
  62         0x02,                   /* Page length - 2 */
  63         0x01,                   /* Trespass code */
  64         0xff,                   /* Trespass target */
  65 };
  66
  67 static const char * lun_state[] =
  68 {
  69     "not bound",
  70     "bound",
  71     "owned",
  72 };
  73
  74 struct clariion_dh_data {
  75         /*
  76          * Flags:
  77          *  CLARIION_SHORT_TRESPASS
  78          * Use short trespass command (FC-series) or the long version
  79          * (default for AX/CX CLARiiON arrays).
  80          *
  81          *  CLARIION_HONOR_RESERVATIONS
  82          * Whether or not (default) to honor SCSI reservations when
  83          * initiating a switch-over.
  84          */
  85         unsigned flags;
  86         /*
  87          * I/O buffer for both MODE_SELECT and INQUIRY commands.
  88          */
  89         unsigned char buffer[CLARIION_BUFFER_SIZE];
  90         /*
  91          * LUN state
  92          */
  93         int lun_state;
  94         /*
  95          * SP Port number
  96          */
  97         int port;
  98         /*
  99          * which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
 100          * path's mapped LUN
 101          */
 102         int default_sp;
 103         /*
 104          * which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
 105          * path's mapped LUN
 106          */
 107         int current_sp;
 108 };
 109
 110 /*
 111  * Parse MODE_SELECT cmd reply.
 112  */
 113 static int trespass_endio(struct scsi_device *sdev,
 114                           struct scsi_sense_hdr *sshdr)
 115 {
 116         int err = SCSI_DH_IO;
 117
 118         sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
 119                     "0x%2x, 0x%2x while sending CLARiiON trespass "
 120                     "command.\n", CLARIION_NAME, sshdr->sense_key,
 121                     sshdr->asc, sshdr->ascq);
 122
 123         if (sshdr->sense_key == 0x05 && sshdr->asc == 0x04 &&
 124             sshdr->ascq == 0x00) {
 125                 /*
 126                  * Array based copy in progress -- do not send
 127                  * mode_select or copy will be aborted mid-stream.
 128                  */
 129                 sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
 130                             "progress while sending CLARiiON trespass "
 131                             "command.\n", CLARIION_NAME);
 132                 err = SCSI_DH_DEV_TEMP_BUSY;
 133         } else if (sshdr->sense_key == 0x02 && sshdr->asc == 0x04 &&
 134                    sshdr->ascq == 0x03) {
 135                 /*
 136                  * LUN Not Ready - Manual Intervention Required
 137                  * indicates in-progress ucode upgrade (NDU).
 138                  */
 139                 sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
 140                             "ucode upgrade NDU operation while sending "
 141                             "CLARiiON trespass command.\n", CLARIION_NAME);
 142                 err = SCSI_DH_DEV_TEMP_BUSY;
 143         } else
 144                 err = SCSI_DH_DEV_FAILED;
 145         return err;
 146 }
 147
 148 static int parse_sp_info_reply(struct scsi_device *sdev,
 149                                struct clariion_dh_data *csdev)
 150 {
 151         int err = SCSI_DH_OK;
 152
 153         /* check for in-progress ucode upgrade (NDU) */
 154         if (csdev->buffer[48] != 0) {
 155                 sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
 156                             "ucode upgrade NDU operation while finding "
 157                             "current active SP.", CLARIION_NAME);
 158                 err = SCSI_DH_DEV_TEMP_BUSY;
 159                 goto out;
 160         }
 161         if (csdev->buffer[4] > 2) {
 162                 /* Invalid buffer format */
 163                 sdev_printk(KERN_NOTICE, sdev,
 164                             "%s: invalid VPD page 0xC0 format\n",
 165                             CLARIION_NAME);
 166                 err = SCSI_DH_NOSYS;
 167                 goto out;
 168         }
 169         switch (csdev->buffer[28] & 0x0f) {
 170         case 6:
 171                 sdev_printk(KERN_NOTICE, sdev,
 172                             "%s: ALUA failover mode detected\n",
 173                             CLARIION_NAME);
 174                 break;
 175         case 4:
 176                 /* Linux failover */
 177                 break;
 178         default:
 179                 sdev_printk(KERN_WARNING, sdev,
 180                             "%s: Invalid failover mode %d\n",
 181                             CLARIION_NAME, csdev->buffer[28] & 0x0f);
 182                 err = SCSI_DH_NOSYS;
 183                 goto out;
 184         }
 185
 186         csdev->default_sp = csdev->buffer[5];
 187         csdev->lun_state = csdev->buffer[4];
 188         csdev->current_sp = csdev->buffer[8];
 189         csdev->port = csdev->buffer[7];
 190         if (csdev->lun_state == CLARIION_LUN_OWNED)
 191                 sdev->access_state = SCSI_ACCESS_STATE_OPTIMAL;
 192         else
 193                 sdev->access_state = SCSI_ACCESS_STATE_STANDBY;
 194         if (csdev->default_sp == csdev->current_sp)
 195                 sdev->access_state |= SCSI_ACCESS_STATE_PREFERRED;
 196 out:
 197         return err;
 198 }
 199
 200 #define emc_default_str "FC (Legacy)"
 201
 202 static char * parse_sp_model(struct scsi_device *sdev, unsigned char *buffer)
 203 {
 204         unsigned char len = buffer[4] + 5;
 205         char *sp_model = NULL;
 206         unsigned char sp_len, serial_len;
 207
 208         if (len < 160) {
 209                 sdev_printk(KERN_WARNING, sdev,
 210                             "%s: Invalid information section length %d\n",
 211                             CLARIION_NAME, len);
 212                 /* Check for old FC arrays */
 213                 if (!strncmp(buffer + 8, "DGC", 3)) {
 214                         /* Old FC array, not supporting extended information */
 215                         sp_model = emc_default_str;
 216                 }
 217                 goto out;
 218         }
 219
 220         /*
 221          * Parse extended information for SP model number
 222          */
 223         serial_len = buffer[160];
 224         if (serial_len == 0 || serial_len + 161 > len) {
 225                 sdev_printk(KERN_WARNING, sdev,
 226                             "%s: Invalid array serial number length %d\n",
 227                             CLARIION_NAME, serial_len);
 228                 goto out;
 229         }
 230         sp_len = buffer[99];
 231         if (sp_len == 0 || serial_len + sp_len + 161 > len) {
 232                 sdev_printk(KERN_WARNING, sdev,
 233                             "%s: Invalid model number length %d\n",
 234                             CLARIION_NAME, sp_len);
 235                 goto out;
 236         }
 237         sp_model = &buffer[serial_len + 161];
 238         /* Strip whitespace at the end */
 239         while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
 240                 sp_len--;
 241
 242         sp_model[sp_len] = '\0';
 243
 244 out:
 245         return sp_model;
 246 }
 247
 248 static int send_trespass_cmd(struct scsi_device *sdev,
 249                             struct clariion_dh_data *csdev)
 250 {
 251         unsigned char *page22;
 252         unsigned char cdb[COMMAND_SIZE(MODE_SELECT)];
 253         int err, res = SCSI_DH_OK, len;
 254         struct scsi_sense_hdr sshdr;
 255         u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 256                 REQ_FAILFAST_DRIVER;
 257
 258         if (csdev->flags & CLARIION_SHORT_TRESPASS) {
 259                 page22 = short_trespass;
 260                 if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 261                         /* Set Honor Reservations bit */
 262                         page22[6] |= 0x80;
 263                 len = sizeof(short_trespass);
 264                 cdb[0] = MODE_SELECT;
 265                 cdb[1] = 0x10;
 266                 cdb[4] = len;
 267         } else {
 268                 page22 = long_trespass;
 269                 if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
 270                         /* Set Honor Reservations bit */
 271                         page22[10] |= 0x80;
 272                 len = sizeof(long_trespass);
 273                 cdb[0] = MODE_SELECT_10;
 274                 cdb[8] = len;
 275         }
 276         BUG_ON((len > CLARIION_BUFFER_SIZE));
 277         memcpy(csdev->buffer, page22, len);
 278
 279         err = scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
 280                                      csdev->buffer, len, &sshdr,
 281                                      CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
 282                                      NULL, req_flags, 0);
 283         if (err) {
 284                 if (scsi_sense_valid(&sshdr))
 285                         res = trespass_endio(sdev, &sshdr);
 286                 else {
 287                         sdev_printk(KERN_INFO, sdev,
 288                                     "%s: failed to send MODE SELECT: %x\n",
 289                                     CLARIION_NAME, err);
 290                         res = SCSI_DH_IO;
 291                 }
 292         }
 293
 294         return res;
 295 }
 296
 297 static int clariion_check_sense(struct scsi_device *sdev,
 298                                 struct scsi_sense_hdr *sense_hdr)
 299 {
 300         switch (sense_hdr->sense_key) {
 301         case NOT_READY:
 302                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
 303                         /*
 304                          * LUN Not Ready - Manual Intervention Required
 305                          * indicates this is a passive path.
 306                          *
 307                          * FIXME: However, if this is seen and EVPD C0
 308                          * indicates that this is due to a NDU in
 309                          * progress, we should set FAIL_PATH too.
 310                          * This indicates we might have to do a SCSI
 311                          * inquiry in the end_io path. Ugh.
 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 ILLEGAL_REQUEST:
 319                 if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
 320                         /*
 321                          * An array based copy is in progress. Do not
 322                          * fail the path, do not bypass to another PG,
 323                          * do not retry. Fail the IO immediately.
 324                          * (Actually this is the same conclusion as in
 325                          * the default handler, but lets make sure.)
 326                          *
 327                          * Can return FAILED only when we want the error
 328                          * recovery process to kick in.
 329                          */
 330                         return SUCCESS;
 331                 break;
 332         case UNIT_ATTENTION:
 333                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 334                         /*
 335                          * Unit Attention Code. This is the first IO
 336                          * to the new path, so just retry.
 337                          */
 338                         return ADD_TO_MLQUEUE;
 339                 break;
 340         }
 341
 342         return SCSI_RETURN_NOT_HANDLED;
 343 }
 344
 345 static int clariion_prep_fn(struct scsi_device *sdev, struct request *req)
 346 {
 347         struct clariion_dh_data *h = sdev->handler_data;
 348         int ret = BLKPREP_OK;
 349
 350         if (h->lun_state != CLARIION_LUN_OWNED) {
 351                 ret = BLKPREP_KILL;
 352                 req->rq_flags |= RQF_QUIET;
 353         }
 354         return ret;
 355
 356 }
 357
 358 static int clariion_std_inquiry(struct scsi_device *sdev,
 359                                 struct clariion_dh_data *csdev)
 360 {
 361         int err;
 362         char *sp_model;
 363
 364         sp_model = parse_sp_model(sdev, sdev->inquiry);
 365         if (!sp_model) {
 366                 err = SCSI_DH_DEV_UNSUPP;
 367                 goto out;
 368         }
 369
 370         /*
 371          * FC Series arrays do not support long trespass
 372          */
 373         if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
 374                 csdev->flags |= CLARIION_SHORT_TRESPASS;
 375
 376         sdev_printk(KERN_INFO, sdev,
 377                     "%s: detected Clariion %s, flags %x\n",
 378                     CLARIION_NAME, sp_model, csdev->flags);
 379 out:
 380         return err;
 381 }
 382
 383 static int clariion_send_inquiry(struct scsi_device *sdev,
 384                                  struct clariion_dh_data *csdev)
 385 {
 386         int err = SCSI_DH_IO;
 387
 388         if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
 389                                CLARIION_BUFFER_SIZE))
 390                 err = parse_sp_info_reply(sdev, csdev);
 391
 392         return err;
 393 }
 394
 395 static int clariion_activate(struct scsi_device *sdev,
 396                                 activate_complete fn, void *data)
 397 {
 398         struct clariion_dh_data *csdev = sdev->handler_data;
 399         int result;
 400
 401         result = clariion_send_inquiry(sdev, csdev);
 402         if (result != SCSI_DH_OK)
 403                 goto done;
 404
 405         if (csdev->lun_state == CLARIION_LUN_OWNED)
 406                 goto done;
 407
 408         result = send_trespass_cmd(sdev, csdev);
 409         if (result != SCSI_DH_OK)
 410                 goto done;
 411         sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
 412                     CLARIION_NAME,
 413                     csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
 414
 415         /* Update status */
 416         result = clariion_send_inquiry(sdev, csdev);
 417         if (result != SCSI_DH_OK)
 418                 goto done;
 419
 420 done:
 421         sdev_printk(KERN_INFO, sdev,
 422                     "%s: at SP %c Port %d (%s, default SP %c)\n",
 423                     CLARIION_NAME, csdev->current_sp + 'A',
 424                     csdev->port, lun_state[csdev->lun_state],
 425                     csdev->default_sp + 'A');
 426
 427         if (fn)
 428                 fn(data, result);
 429         return 0;
 430 }
 431 /*
 432  * params - parameters in the following format
 433  *      "no_of_params\0param1\0param2\0param3\0...\0"
 434  *      for example, string for 2 parameters with value 10 and 21
 435  *      is specified as "2\010\021\0".
 436  */
 437 static int clariion_set_params(struct scsi_device *sdev, const char *params)
 438 {
 439         struct clariion_dh_data *csdev = sdev->handler_data;
 440         unsigned int hr = 0, st = 0, argc;
 441         const char *p = params;
 442         int result = SCSI_DH_OK;
 443
 444         if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
 445                 return -EINVAL;
 446
 447         while (*p++)
 448                 ;
 449         if ((sscanf(p, "%u", &st) != 1) || (st > 1))
 450                 return -EINVAL;
 451
 452         while (*p++)
 453                 ;
 454         if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
 455                 return -EINVAL;
 456
 457         if (st)
 458                 csdev->flags |= CLARIION_SHORT_TRESPASS;
 459         else
 460                 csdev->flags &= ~CLARIION_SHORT_TRESPASS;
 461
 462         if (hr)
 463                 csdev->flags |= CLARIION_HONOR_RESERVATIONS;
 464         else
 465                 csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;
 466
 467         /*
 468          * If this path is owned, we have to send a trespass command
 469          * with the new parameters. If not, simply return. Next trespass
 470          * command would use the parameters.
 471          */
 472         if (csdev->lun_state != CLARIION_LUN_OWNED)
 473                 goto done;
 474
 475         csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
 476         result = send_trespass_cmd(sdev, csdev);
 477         if (result != SCSI_DH_OK)
 478                 goto done;
 479
 480         /* Update status */
 481         result = clariion_send_inquiry(sdev, csdev);
 482
 483 done:
 484         return result;
 485 }
 486
 487 static int clariion_bus_attach(struct scsi_device *sdev)
 488 {
 489         struct clariion_dh_data *h;
 490         int err;
 491
 492         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 493         if (!h)
 494                 return -ENOMEM;
 495         h->lun_state = CLARIION_LUN_UNINITIALIZED;
 496         h->default_sp = CLARIION_UNBOUND_LU;
 497         h->current_sp = CLARIION_UNBOUND_LU;
 498
 499         err = clariion_std_inquiry(sdev, h);
 500         if (err != SCSI_DH_OK)
 501                 goto failed;
 502
 503         err = clariion_send_inquiry(sdev, h);
 504         if (err != SCSI_DH_OK)
 505                 goto failed;
 506
 507         sdev_printk(KERN_INFO, sdev,
 508                     "%s: connected to SP %c Port %d (%s, default SP %c)\n",
 509                     CLARIION_NAME, h->current_sp + 'A',
 510                     h->port, lun_state[h->lun_state],
 511                     h->default_sp + 'A');
 512
 513         sdev->handler_data = h;
 514         return 0;
 515
 516 failed:
 517         kfree(h);
 518         return -EINVAL;
 519 }
 520
 521 static void clariion_bus_detach(struct scsi_device *sdev)
 522 {
 523         kfree(sdev->handler_data);
 524         sdev->handler_data = NULL;
 525 }
 526
 527 static struct scsi_device_handler clariion_dh = {
 528         .name           = CLARIION_NAME,
 529         .module         = THIS_MODULE,
 530         .attach         = clariion_bus_attach,
 531         .detach         = clariion_bus_detach,
 532         .check_sense    = clariion_check_sense,
 533         .activate       = clariion_activate,
 534         .prep_fn        = clariion_prep_fn,
 535         .set_params     = clariion_set_params,
 536 };
 537
 538 static int __init clariion_init(void)
 539 {
 540         int r;
 541
 542         r = scsi_register_device_handler(&clariion_dh);
 543         if (r != 0)
 544                 printk(KERN_ERR "%s: Failed to register scsi device handler.",
 545                         CLARIION_NAME);
 546         return r;
 547 }
 548
 549 static void __exit clariion_exit(void)
 550 {
 551         scsi_unregister_device_handler(&clariion_dh);
 552 }
 553
 554 module_init(clariion_init);
 555 module_exit(clariion_exit);
 556
 557 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
 558 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
 559 MODULE_LICENSE("GPL");