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 <scsi/scsi.h>
  24 #include <scsi/scsi_eh.h>
  25 #include <scsi/scsi_dh.h>
  26 #include <scsi/scsi_device.h>
  27
  28 #define CLARIION_NAME                   "emc_clariion"
  29
  30 #define CLARIION_TRESPASS_PAGE          0x22
  31 #define CLARIION_BUFFER_SIZE            0x80
  32 #define CLARIION_TIMEOUT                (60 * HZ)
  33 #define CLARIION_RETRIES                3
  34 #define CLARIION_UNBOUND_LU             -1
  35
  36 static unsigned char long_trespass[] = {
  37         0, 0, 0, 0,
  38         CLARIION_TRESPASS_PAGE, /* Page code */
  39         0x09,                   /* Page length - 2 */
  40         0x81,                   /* Trespass code + Honor reservation bit */
  41         0xff, 0xff,             /* Trespass target */
  42         0, 0, 0, 0, 0, 0        /* Reserved bytes / unknown */
  43 };
  44
  45 static unsigned char long_trespass_hr[] = {
  46         0, 0, 0, 0,
  47         CLARIION_TRESPASS_PAGE, /* Page code */
  48         0x09,                   /* Page length - 2 */
  49         0x01,                   /* Trespass code + Honor reservation bit */
  50         0xff, 0xff,             /* Trespass target */
  51         0, 0, 0, 0, 0, 0        /* Reserved bytes / unknown */
  52 };
  53
  54 static unsigned char short_trespass[] = {
  55         0, 0, 0, 0,
  56         CLARIION_TRESPASS_PAGE, /* Page code */
  57         0x02,                   /* Page length - 2 */
  58         0x81,                   /* Trespass code + Honor reservation bit */
  59         0xff,                   /* Trespass target */
  60 };
  61
  62 static unsigned char short_trespass_hr[] = {
  63         0, 0, 0, 0,
  64         CLARIION_TRESPASS_PAGE, /* Page code */
  65         0x02,                   /* Page length - 2 */
  66         0x01,                   /* Trespass code + Honor reservation bit */
  67         0xff,                   /* Trespass target */
  68 };
  69
  70 struct clariion_dh_data {
  71         /*
  72          * Use short trespass command (FC-series) or the long version
  73          * (default for AX/CX CLARiiON arrays).
  74          */
  75         unsigned short_trespass;
  76         /*
  77          * Whether or not (default) to honor SCSI reservations when
  78          * initiating a switch-over.
  79          */
  80         unsigned hr;
  81         /* I/O buffer for both MODE_SELECT and INQUIRY commands. */
  82         char buffer[CLARIION_BUFFER_SIZE];
  83         /*
  84          * SCSI sense buffer for commands -- assumes serial issuance
  85          * and completion sequence of all commands for same multipath.
  86          */
  87         unsigned char sense[SCSI_SENSE_BUFFERSIZE];
  88         /* which SP (A=0,B=1,UNBOUND=-1) is dflt SP for path's mapped dev */
  89         int default_sp;
  90         /* which SP (A=0,B=1,UNBOUND=-1) is active for path's mapped dev */
  91         int current_sp;
  92 };
  93
  94 static inline struct clariion_dh_data
  95                         *get_clariion_data(struct scsi_device *sdev)
  96 {
  97         struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
  98         BUG_ON(scsi_dh_data == NULL);
  99         return ((struct clariion_dh_data *) scsi_dh_data->buf);
 100 }
 101
 102 /*
 103  * Parse MODE_SELECT cmd reply.
 104  */
 105 static int trespass_endio(struct scsi_device *sdev, int result)
 106 {
 107         int err = SCSI_DH_OK;
 108         struct scsi_sense_hdr sshdr;
 109         struct clariion_dh_data *csdev = get_clariion_data(sdev);
 110         char *sense = csdev->sense;
 111
 112         if (status_byte(result) == CHECK_CONDITION &&
 113             scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)) {
 114                 sdev_printk(KERN_ERR, sdev, "Found valid sense data 0x%2x, "
 115                             "0x%2x, 0x%2x while sending CLARiiON trespass "
 116                             "command.\n", sshdr.sense_key, sshdr.asc,
 117                              sshdr.ascq);
 118
 119                 if ((sshdr.sense_key == 0x05) && (sshdr.asc == 0x04) &&
 120                      (sshdr.ascq == 0x00)) {
 121                         /*
 122                          * Array based copy in progress -- do not send
 123                          * mode_select or copy will be aborted mid-stream.
 124                          */
 125                         sdev_printk(KERN_INFO, sdev, "Array Based Copy in "
 126                                     "progress while sending CLARiiON trespass "
 127                                     "command.\n");
 128                         err = SCSI_DH_DEV_TEMP_BUSY;
 129                 } else if ((sshdr.sense_key == 0x02) && (sshdr.asc == 0x04) &&
 130                             (sshdr.ascq == 0x03)) {
 131                         /*
 132                          * LUN Not Ready - Manual Intervention Required
 133                          * indicates in-progress ucode upgrade (NDU).
 134                          */
 135                         sdev_printk(KERN_INFO, sdev, "Detected in-progress "
 136                                     "ucode upgrade NDU operation while sending "
 137                                     "CLARiiON trespass command.\n");
 138                         err = SCSI_DH_DEV_TEMP_BUSY;
 139                 } else
 140                         err = SCSI_DH_DEV_FAILED;
 141         } else if (result) {
 142                 sdev_printk(KERN_ERR, sdev, "Error 0x%x while sending "
 143                             "CLARiiON trespass command.\n", result);
 144                 err = SCSI_DH_IO;
 145         }
 146
 147         return err;
 148 }
 149
 150 static int parse_sp_info_reply(struct scsi_device *sdev, int result,
 151                 int *default_sp, int *current_sp, int *new_current_sp)
 152 {
 153         int err = SCSI_DH_OK;
 154         struct clariion_dh_data *csdev = get_clariion_data(sdev);
 155
 156         if (result == 0) {
 157                 /* check for in-progress ucode upgrade (NDU) */
 158                 if (csdev->buffer[48] != 0) {
 159                         sdev_printk(KERN_NOTICE, sdev, "Detected in-progress "
 160                                "ucode upgrade NDU operation while finding "
 161                                "current active SP.");
 162                         err = SCSI_DH_DEV_TEMP_BUSY;
 163                 } else {
 164                         *default_sp = csdev->buffer[5];
 165
 166                         if (csdev->buffer[4] == 2)
 167                                 /* SP for path is current */
 168                                 *current_sp = csdev->buffer[8];
 169                         else {
 170                                 if (csdev->buffer[4] == 1)
 171                                         /* SP for this path is NOT current */
 172                                         if (csdev->buffer[8] == 0)
 173                                                 *current_sp = 1;
 174                                         else
 175                                                 *current_sp = 0;
 176                                 else
 177                                         /* unbound LU or LUNZ */
 178                                         *current_sp = CLARIION_UNBOUND_LU;
 179                         }
 180                         *new_current_sp =  csdev->buffer[8];
 181                 }
 182         } else {
 183                 struct scsi_sense_hdr sshdr;
 184
 185                 err = SCSI_DH_IO;
 186
 187                 if (scsi_normalize_sense(csdev->sense, SCSI_SENSE_BUFFERSIZE,
 188                                                            &sshdr))
 189                         sdev_printk(KERN_ERR, sdev, "Found valid sense data "
 190                               "0x%2x, 0x%2x, 0x%2x while finding current "
 191                               "active SP.", sshdr.sense_key, sshdr.asc,
 192                               sshdr.ascq);
 193                 else
 194                         sdev_printk(KERN_ERR, sdev, "Error 0x%x finding "
 195                               "current active SP.", result);
 196         }
 197
 198         return err;
 199 }
 200
 201 static int sp_info_endio(struct scsi_device *sdev, int result,
 202                                         int mode_select_sent, int *done)
 203 {
 204         struct clariion_dh_data *csdev = get_clariion_data(sdev);
 205         int err_flags, default_sp, current_sp, new_current_sp;
 206
 207         err_flags = parse_sp_info_reply(sdev, result, &default_sp,
 208                                              &current_sp, &new_current_sp);
 209
 210         if (err_flags != SCSI_DH_OK)
 211                 goto done;
 212
 213         if (mode_select_sent) {
 214                 csdev->default_sp = default_sp;
 215                 csdev->current_sp = current_sp;
 216         } else {
 217                 /*
 218                  * Issue the actual module_selec request IFF either
 219                  * (1) we do not know the identity of the current SP OR
 220                  * (2) what we think we know is actually correct.
 221                  */
 222                 if ((current_sp != CLARIION_UNBOUND_LU) &&
 223                     (new_current_sp != current_sp)) {
 224
 225                         csdev->default_sp = default_sp;
 226                         csdev->current_sp = current_sp;
 227
 228                         sdev_printk(KERN_INFO, sdev, "Ignoring path group "
 229                                "switch-over command for CLARiiON SP%s since "
 230                                " mapped device is already initialized.",
 231                                current_sp ? "B" : "A");
 232                         if (done)
 233                                 *done = 1; /* as good as doing it */
 234                 }
 235         }
 236 done:
 237         return err_flags;
 238 }
 239
 240 /*
 241  * Get block request for REQ_BLOCK_PC command issued to path.  Currently
 242  * limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
 243  *
 244  * Uses data and sense buffers in hardware handler context structure and
 245  * assumes serial servicing of commands, both issuance and completion.
 246  */
 247 static struct request *get_req(struct scsi_device *sdev, int cmd)
 248 {
 249         struct clariion_dh_data *csdev = get_clariion_data(sdev);
 250         struct request *rq;
 251         unsigned char *page22;
 252         int len = 0;
 253
 254         rq = blk_get_request(sdev->request_queue,
 255                         (cmd == MODE_SELECT) ? WRITE : READ, GFP_ATOMIC);
 256         if (!rq) {
 257                 sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
 258                 return NULL;
 259         }
 260
 261         memset(&rq->cmd, 0, BLK_MAX_CDB);
 262         rq->cmd[0] = cmd;
 263         rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
 264
 265         switch (cmd) {
 266         case MODE_SELECT:
 267                 if (csdev->short_trespass) {
 268                         page22 = csdev->hr ? short_trespass_hr : short_trespass;
 269                         len = sizeof(short_trespass);
 270                 } else {
 271                         page22 = csdev->hr ? long_trespass_hr : long_trespass;
 272                         len = sizeof(long_trespass);
 273                 }
 274                 /*
 275                  * Can't DMA from kernel BSS -- must copy selected trespass
 276                  * command mode page contents to context buffer which is
 277                  * allocated by kmalloc.
 278                  */
 279                 BUG_ON((len > CLARIION_BUFFER_SIZE));
 280                 memcpy(csdev->buffer, page22, len);
 281                 rq->cmd_flags |= REQ_RW;
 282                 rq->cmd[1] = 0x10;
 283                 break;
 284         case INQUIRY:
 285                 rq->cmd[1] = 0x1;
 286                 rq->cmd[2] = 0xC0;
 287                 len = CLARIION_BUFFER_SIZE;
 288                 memset(csdev->buffer, 0, CLARIION_BUFFER_SIZE);
 289                 break;
 290         default:
 291                 BUG_ON(1);
 292                 break;
 293         }
 294
 295         rq->cmd[4] = len;
 296         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 297         rq->cmd_flags |= REQ_FAILFAST;
 298         rq->timeout = CLARIION_TIMEOUT;
 299         rq->retries = CLARIION_RETRIES;
 300
 301         rq->sense = csdev->sense;
 302         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 303         rq->sense_len = 0;
 304
 305         if (blk_rq_map_kern(sdev->request_queue, rq, csdev->buffer,
 306                                                         len, GFP_ATOMIC)) {
 307                 __blk_put_request(rq->q, rq);
 308                 return NULL;
 309         }
 310
 311         return rq;
 312 }
 313
 314 static int send_cmd(struct scsi_device *sdev, int cmd)
 315 {
 316         struct request *rq = get_req(sdev, cmd);
 317
 318         if (!rq)
 319                 return SCSI_DH_RES_TEMP_UNAVAIL;
 320
 321         return blk_execute_rq(sdev->request_queue, NULL, rq, 1);
 322 }
 323
 324 static int clariion_activate(struct scsi_device *sdev)
 325 {
 326         int result, done = 0;
 327
 328         result = send_cmd(sdev, INQUIRY);
 329         result = sp_info_endio(sdev, result, 0, &done);
 330         if (result || done)
 331                 goto done;
 332
 333         result = send_cmd(sdev, MODE_SELECT);
 334         result = trespass_endio(sdev, result);
 335         if (result)
 336                 goto done;
 337
 338         result = send_cmd(sdev, INQUIRY);
 339         result = sp_info_endio(sdev, result, 1, NULL);
 340 done:
 341         return result;
 342 }
 343
 344 static int clariion_check_sense(struct scsi_device *sdev,
 345                                 struct scsi_sense_hdr *sense_hdr)
 346 {
 347         switch (sense_hdr->sense_key) {
 348         case NOT_READY:
 349                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
 350                         /*
 351                          * LUN Not Ready - Manual Intervention Required
 352                          * indicates this is a passive path.
 353                          *
 354                          * FIXME: However, if this is seen and EVPD C0
 355                          * indicates that this is due to a NDU in
 356                          * progress, we should set FAIL_PATH too.
 357                          * This indicates we might have to do a SCSI
 358                          * inquiry in the end_io path. Ugh.
 359                          *
 360                          * Can return FAILED only when we want the error
 361                          * recovery process to kick in.
 362                          */
 363                         return SUCCESS;
 364                 break;
 365         case ILLEGAL_REQUEST:
 366                 if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
 367                         /*
 368                          * An array based copy is in progress. Do not
 369                          * fail the path, do not bypass to another PG,
 370                          * do not retry. Fail the IO immediately.
 371                          * (Actually this is the same conclusion as in
 372                          * the default handler, but lets make sure.)
 373                          *
 374                          * Can return FAILED only when we want the error
 375                          * recovery process to kick in.
 376                          */
 377                         return SUCCESS;
 378                 break;
 379         case UNIT_ATTENTION:
 380                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 381                         /*
 382                          * Unit Attention Code. This is the first IO
 383                          * to the new path, so just retry.
 384                          */
 385                         return NEEDS_RETRY;
 386                 break;
 387         }
 388
 389         /* success just means we do not care what scsi-ml does */
 390         return SUCCESS;
 391 }
 392
 393 const struct scsi_dh_devlist clariion_dev_list[] = {
 394         {"DGC", "RAID"},
 395         {"DGC", "DISK"},
 396         {NULL, NULL},
 397 };
 398
 399 static int clariion_bus_attach(struct scsi_device *sdev);
 400 static void clariion_bus_detach(struct scsi_device *sdev);
 401
 402 static struct scsi_device_handler clariion_dh = {
 403         .name           = CLARIION_NAME,
 404         .module         = THIS_MODULE,
 405         .devlist        = clariion_dev_list,
 406         .attach         = clariion_bus_attach,
 407         .detach         = clariion_bus_detach,
 408         .check_sense    = clariion_check_sense,
 409         .activate       = clariion_activate,
 410 };
 411
 412 /*
 413  * TODO: need some interface so we can set trespass values
 414  */
 415 static int clariion_bus_attach(struct scsi_device *sdev)
 416 {
 417         struct scsi_dh_data *scsi_dh_data;
 418         struct clariion_dh_data *h;
 419         unsigned long flags;
 420
 421         scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
 422                                + sizeof(*h) , GFP_KERNEL);
 423         if (!scsi_dh_data) {
 424                 sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
 425                             CLARIION_NAME);
 426                 return -ENOMEM;
 427         }
 428
 429         scsi_dh_data->scsi_dh = &clariion_dh;
 430         h = (struct clariion_dh_data *) scsi_dh_data->buf;
 431         h->default_sp = CLARIION_UNBOUND_LU;
 432         h->current_sp = CLARIION_UNBOUND_LU;
 433
 434         spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 435         sdev->scsi_dh_data = scsi_dh_data;
 436         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 437
 438         sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", CLARIION_NAME);
 439         try_module_get(THIS_MODULE);
 440
 441         return 0;
 442 }
 443
 444 static void clariion_bus_detach(struct scsi_device *sdev)
 445 {
 446         struct scsi_dh_data *scsi_dh_data;
 447         unsigned long flags;
 448
 449         spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 450         scsi_dh_data = sdev->scsi_dh_data;
 451         sdev->scsi_dh_data = NULL;
 452         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 453
 454         sdev_printk(KERN_NOTICE, sdev, "Detached %s.\n",
 455                     CLARIION_NAME);
 456
 457         kfree(scsi_dh_data);
 458         module_put(THIS_MODULE);
 459 }
 460
 461 static int __init clariion_init(void)
 462 {
 463         int r;
 464
 465         r = scsi_register_device_handler(&clariion_dh);
 466         if (r != 0)
 467                 printk(KERN_ERR "Failed to register scsi device handler.");
 468         return r;
 469 }
 470
 471 static void __exit clariion_exit(void)
 472 {
 473         scsi_unregister_device_handler(&clariion_dh);
 474 }
 475
 476 module_init(clariion_init);
 477 module_exit(clariion_exit);
 478
 479 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
 480 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
 481 MODULE_LICENSE("GPL");