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(sdev, cdb, DMA_TO_DEVICE, csdev->buffer, len, NULL,
 280                         &sshdr, CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
 281                         req_flags, 0, NULL);
 282         if (err) {
 283                 if (scsi_sense_valid(&sshdr))
 284                         res = trespass_endio(sdev, &sshdr);
 285                 else {
 286                         sdev_printk(KERN_INFO, sdev,
 287                                     "%s: failed to send MODE SELECT: %x\n",
 288                                     CLARIION_NAME, err);
 289                         res = SCSI_DH_IO;
 290                 }
 291         }
 292
 293         return res;
 294 }
 295
 296 static int clariion_check_sense(struct scsi_device *sdev,
 297                                 struct scsi_sense_hdr *sense_hdr)
 298 {
 299         switch (sense_hdr->sense_key) {
 300         case NOT_READY:
 301                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
 302                         /*
 303                          * LUN Not Ready - Manual Intervention Required
 304                          * indicates this is a passive path.
 305                          *
 306                          * FIXME: However, if this is seen and EVPD C0
 307                          * indicates that this is due to a NDU in
 308                          * progress, we should set FAIL_PATH too.
 309                          * This indicates we might have to do a SCSI
 310                          * inquiry in the end_io path. Ugh.
 311                          *
 312                          * Can return FAILED only when we want the error
 313                          * recovery process to kick in.
 314                          */
 315                         return SUCCESS;
 316                 break;
 317         case ILLEGAL_REQUEST:
 318                 if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
 319                         /*
 320                          * An array based copy is in progress. Do not
 321                          * fail the path, do not bypass to another PG,
 322                          * do not retry. Fail the IO immediately.
 323                          * (Actually this is the same conclusion as in
 324                          * the default handler, but lets make sure.)
 325                          *
 326                          * Can return FAILED only when we want the error
 327                          * recovery process to kick in.
 328                          */
 329                         return SUCCESS;
 330                 break;
 331         case UNIT_ATTENTION:
 332                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 333                         /*
 334                          * Unit Attention Code. This is the first IO
 335                          * to the new path, so just retry.
 336                          */
 337                         return ADD_TO_MLQUEUE;
 338                 break;
 339         }
 340
 341         return SCSI_RETURN_NOT_HANDLED;
 342 }
 343
 344 static int clariion_prep_fn(struct scsi_device *sdev, struct request *req)
 345 {
 346         struct clariion_dh_data *h = sdev->handler_data;
 347         int ret = BLKPREP_OK;
 348
 349         if (h->lun_state != CLARIION_LUN_OWNED) {
 350                 ret = BLKPREP_KILL;
 351                 req->rq_flags |= RQF_QUIET;
 352         }
 353         return ret;
 354
 355 }
 356
 357 static int clariion_std_inquiry(struct scsi_device *sdev,
 358                                 struct clariion_dh_data *csdev)
 359 {
 360         int err = SCSI_DH_OK;
 361         char *sp_model;
 362
 363         sp_model = parse_sp_model(sdev, sdev->inquiry);
 364         if (!sp_model) {
 365                 err = SCSI_DH_DEV_UNSUPP;
 366                 goto out;
 367         }
 368
 369         /*
 370          * FC Series arrays do not support long trespass
 371          */
 372         if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
 373                 csdev->flags |= CLARIION_SHORT_TRESPASS;
 374
 375         sdev_printk(KERN_INFO, sdev,
 376                     "%s: detected Clariion %s, flags %x\n",
 377                     CLARIION_NAME, sp_model, csdev->flags);
 378 out:
 379         return err;
 380 }
 381
 382 static int clariion_send_inquiry(struct scsi_device *sdev,
 383                                  struct clariion_dh_data *csdev)
 384 {
 385         int err = SCSI_DH_IO;
 386
 387         if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
 388                                CLARIION_BUFFER_SIZE))
 389                 err = parse_sp_info_reply(sdev, csdev);
 390
 391         return err;
 392 }
 393
 394 static int clariion_activate(struct scsi_device *sdev,
 395                                 activate_complete fn, void *data)
 396 {
 397         struct clariion_dh_data *csdev = sdev->handler_data;
 398         int result;
 399
 400         result = clariion_send_inquiry(sdev, csdev);
 401         if (result != SCSI_DH_OK)
 402                 goto done;
 403
 404         if (csdev->lun_state == CLARIION_LUN_OWNED)
 405                 goto done;
 406
 407         result = send_trespass_cmd(sdev, csdev);
 408         if (result != SCSI_DH_OK)
 409                 goto done;
 410         sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
 411                     CLARIION_NAME,
 412                     csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
 413
 414         /* Update status */
 415         result = clariion_send_inquiry(sdev, csdev);
 416         if (result != SCSI_DH_OK)
 417                 goto done;
 418
 419 done:
 420         sdev_printk(KERN_INFO, sdev,
 421                     "%s: at SP %c Port %d (%s, default SP %c)\n",
 422                     CLARIION_NAME, csdev->current_sp + 'A',
 423                     csdev->port, lun_state[csdev->lun_state],
 424                     csdev->default_sp + 'A');
 425
 426         if (fn)
 427                 fn(data, result);
 428         return 0;
 429 }
 430 /*
 431  * params - parameters in the following format
 432  *      "no_of_params\0param1\0param2\0param3\0...\0"
 433  *      for example, string for 2 parameters with value 10 and 21
 434  *      is specified as "2\010\021\0".
 435  */
 436 static int clariion_set_params(struct scsi_device *sdev, const char *params)
 437 {
 438         struct clariion_dh_data *csdev = sdev->handler_data;
 439         unsigned int hr = 0, st = 0, argc;
 440         const char *p = params;
 441         int result = SCSI_DH_OK;
 442
 443         if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
 444                 return -EINVAL;
 445
 446         while (*p++)
 447                 ;
 448         if ((sscanf(p, "%u", &st) != 1) || (st > 1))
 449                 return -EINVAL;
 450
 451         while (*p++)
 452                 ;
 453         if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
 454                 return -EINVAL;
 455
 456         if (st)
 457                 csdev->flags |= CLARIION_SHORT_TRESPASS;
 458         else
 459                 csdev->flags &= ~CLARIION_SHORT_TRESPASS;
 460
 461         if (hr)
 462                 csdev->flags |= CLARIION_HONOR_RESERVATIONS;
 463         else
 464                 csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;
 465
 466         /*
 467          * If this path is owned, we have to send a trespass command
 468          * with the new parameters. If not, simply return. Next trespass
 469          * command would use the parameters.
 470          */
 471         if (csdev->lun_state != CLARIION_LUN_OWNED)
 472                 goto done;
 473
 474         csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
 475         result = send_trespass_cmd(sdev, csdev);
 476         if (result != SCSI_DH_OK)
 477                 goto done;
 478
 479         /* Update status */
 480         result = clariion_send_inquiry(sdev, csdev);
 481
 482 done:
 483         return result;
 484 }
 485
 486 static int clariion_bus_attach(struct scsi_device *sdev)
 487 {
 488         struct clariion_dh_data *h;
 489         int err;
 490
 491         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 492         if (!h)
 493                 return -ENOMEM;
 494         h->lun_state = CLARIION_LUN_UNINITIALIZED;
 495         h->default_sp = CLARIION_UNBOUND_LU;
 496         h->current_sp = CLARIION_UNBOUND_LU;
 497
 498         err = clariion_std_inquiry(sdev, h);
 499         if (err != SCSI_DH_OK)
 500                 goto failed;
 501
 502         err = clariion_send_inquiry(sdev, h);
 503         if (err != SCSI_DH_OK)
 504                 goto failed;
 505
 506         sdev_printk(KERN_INFO, sdev,
 507                     "%s: connected to SP %c Port %d (%s, default SP %c)\n",
 508                     CLARIION_NAME, h->current_sp + 'A',
 509                     h->port, lun_state[h->lun_state],
 510                     h->default_sp + 'A');
 511
 512         sdev->handler_data = h;
 513         return 0;
 514
 515 failed:
 516         kfree(h);
 517         return -EINVAL;
 518 }
 519
 520 static void clariion_bus_detach(struct scsi_device *sdev)
 521 {
 522         kfree(sdev->handler_data);
 523         sdev->handler_data = NULL;
 524 }
 525
 526 static struct scsi_device_handler clariion_dh = {
 527         .name           = CLARIION_NAME,
 528         .module         = THIS_MODULE,
 529         .attach         = clariion_bus_attach,
 530         .detach         = clariion_bus_detach,
 531         .check_sense    = clariion_check_sense,
 532         .activate       = clariion_activate,
 533         .prep_fn        = clariion_prep_fn,
 534         .set_params     = clariion_set_params,
 535 };
 536
 537 static int __init clariion_init(void)
 538 {
 539         int r;
 540
 541         r = scsi_register_device_handler(&clariion_dh);
 542         if (r != 0)
 543                 printk(KERN_ERR "%s: Failed to register scsi device handler.",
 544                         CLARIION_NAME);
 545         return r;
 546 }
 547
 548 static void __exit clariion_exit(void)
 549 {
 550         scsi_unregister_device_handler(&clariion_dh);
 551 }
 552
 553 module_init(clariion_init);
 554 module_exit(clariion_exit);
 555
 556 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
 557 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
 558 MODULE_LICENSE("GPL");