drivers/s390/block/dasd_diag.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd_diag.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  * Based on.......: linux/drivers/s390/block/mdisk.c
   5  * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
   8  *
   9  */
  10
  11 #include <linux/stddef.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/hdreg.h>
  15 #include <linux/bio.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/jiffies.h>
  19
  20 #include <asm/dasd.h>
  21 #include <asm/debug.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/io.h>
  24 #include <asm/s390_ext.h>
  25 #include <asm/todclk.h>
  26 #include <asm/vtoc.h>
  27 #include <asm/diag.h>
  28
  29 #include "dasd_int.h"
  30 #include "dasd_diag.h"
  31
  32 #define PRINTK_HEADER "dasd(diag):"
  33
  34 MODULE_LICENSE("GPL");
  35
  36 /* The maximum number of blocks per request (max_blocks) is dependent on the
  37  * amount of storage that is available in the static I/O buffer for each
  38  * device. Currently each device gets 2 pages. We want to fit two requests
  39  * into the available memory so that we can immediately start the next if one
  40  * finishes. */
  41 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
  42                            sizeof(struct dasd_diag_req)) / \
  43                            sizeof(struct dasd_diag_bio)) / 2)
  44 #define DIAG_MAX_RETRIES        32
  45 #define DIAG_TIMEOUT            50 * HZ
  46
  47 static struct dasd_discipline dasd_diag_discipline;
  48
  49 struct dasd_diag_private {
  50         struct dasd_diag_characteristics rdc_data;
  51         struct dasd_diag_rw_io iob;
  52         struct dasd_diag_init_io iib;
  53         blocknum_t pt_block;
  54         struct ccw_dev_id dev_id;
  55 };
  56
  57 struct dasd_diag_req {
  58         unsigned int block_count;
  59         struct dasd_diag_bio bio[0];
  60 };
  61
  62 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
  63
  64 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
  65  * and function code cmd.
  66  * In case of an exception return 3. Otherwise return result of bitwise OR of
  67  * resulting condition code and DIAG return code. */
  68 static inline int dia250(void *iob, int cmd)
  69 {
  70         register unsigned long reg2 asm ("2") = (unsigned long) iob;
  71         typedef union {
  72                 struct dasd_diag_init_io init_io;
  73                 struct dasd_diag_rw_io rw_io;
  74         } addr_type;
  75         int rc;
  76
  77         rc = 3;
  78         asm volatile(
  79                 "       diag    2,%2,0x250\n"
  80                 "0:     ipm     %0\n"
  81                 "       srl     %0,28\n"
  82                 "       or      %0,3\n"
  83                 "1:\n"
  84                 EX_TABLE(0b,1b)
  85                 : "+d" (rc), "=m" (*(addr_type *) iob)
  86                 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
  87                 : "3", "cc");
  88         return rc;
  89 }
  90
  91 /* Initialize block I/O to DIAG device using the specified blocksize and
  92  * block offset. On success, return zero and set end_block to contain the
  93  * number of blocks on the device minus the specified offset. Return non-zero
  94  * otherwise. */
  95 static inline int
  96 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
  97              blocknum_t offset, blocknum_t *end_block)
  98 {
  99         struct dasd_diag_private *private;
 100         struct dasd_diag_init_io *iib;
 101         int rc;
 102
 103         private = (struct dasd_diag_private *) device->private;
 104         iib = &private->iib;
 105         memset(iib, 0, sizeof (struct dasd_diag_init_io));
 106
 107         iib->dev_nr = private->dev_id.devno;
 108         iib->block_size = blocksize;
 109         iib->offset = offset;
 110         iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
 111
 112         rc = dia250(iib, INIT_BIO);
 113
 114         if ((rc & 3) == 0 && end_block)
 115                 *end_block = iib->end_block;
 116
 117         return rc;
 118 }
 119
 120 /* Remove block I/O environment for device. Return zero on success, non-zero
 121  * otherwise. */
 122 static inline int
 123 mdsk_term_io(struct dasd_device * device)
 124 {
 125         struct dasd_diag_private *private;
 126         struct dasd_diag_init_io *iib;
 127         int rc;
 128
 129         private = (struct dasd_diag_private *) device->private;
 130         iib = &private->iib;
 131         memset(iib, 0, sizeof (struct dasd_diag_init_io));
 132         iib->dev_nr = private->dev_id.devno;
 133         rc = dia250(iib, TERM_BIO);
 134         return rc;
 135 }
 136
 137 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
 138  * environment. */
 139 static void
 140 dasd_diag_erp(struct dasd_device *device)
 141 {
 142         int rc;
 143
 144         mdsk_term_io(device);
 145         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
 146         if (rc)
 147                 DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, "
 148                             "rc=%d", rc);
 149 }
 150
 151 /* Start a given request at the device. Return zero on success, non-zero
 152  * otherwise. */
 153 static int
 154 dasd_start_diag(struct dasd_ccw_req * cqr)
 155 {
 156         struct dasd_device *device;
 157         struct dasd_diag_private *private;
 158         struct dasd_diag_req *dreq;
 159         int rc;
 160
 161         device = cqr->device;
 162         if (cqr->retries < 0) {
 163                 DEV_MESSAGE(KERN_WARNING, device, "DIAG start_IO: request %p "
 164                             "- no retry left)", cqr);
 165                 cqr->status = DASD_CQR_FAILED;
 166                 return -EIO;
 167         }
 168         private = (struct dasd_diag_private *) device->private;
 169         dreq = (struct dasd_diag_req *) cqr->data;
 170
 171         private->iob.dev_nr = private->dev_id.devno;
 172         private->iob.key = 0;
 173         private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
 174         private->iob.block_count = dreq->block_count;
 175         private->iob.interrupt_params = (addr_t) cqr;
 176         private->iob.bio_list = dreq->bio;
 177         private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
 178
 179         cqr->startclk = get_clock();
 180         cqr->starttime = jiffies;
 181         cqr->retries--;
 182
 183         rc = dia250(&private->iob, RW_BIO);
 184         switch (rc) {
 185         case 0: /* Synchronous I/O finished successfully */
 186                 cqr->stopclk = get_clock();
 187                 cqr->status = DASD_CQR_DONE;
 188                 /* Indicate to calling function that only a dasd_schedule_bh()
 189                    and no timer is needed */
 190                 rc = -EACCES;
 191                 break;
 192         case 8: /* Asynchronous I/O was started */
 193                 cqr->status = DASD_CQR_IN_IO;
 194                 rc = 0;
 195                 break;
 196         default: /* Error condition */
 197                 cqr->status = DASD_CQR_QUEUED;
 198                 DEV_MESSAGE(KERN_WARNING, device, "dia250 returned rc=%d", rc);
 199                 dasd_diag_erp(device);
 200                 rc = -EIO;
 201                 break;
 202         }
 203         return rc;
 204 }
 205
 206 /* Terminate given request at the device. */
 207 static int
 208 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
 209 {
 210         struct dasd_device *device;
 211
 212         device = cqr->device;
 213         mdsk_term_io(device);
 214         mdsk_init_io(device, device->bp_block, 0, NULL);
 215         cqr->status = DASD_CQR_CLEAR;
 216         cqr->stopclk = get_clock();
 217         dasd_schedule_bh(device);
 218         return 0;
 219 }
 220
 221 /* Handle external interruption. */
 222 static void
 223 dasd_ext_handler(__u16 code)
 224 {
 225         struct dasd_ccw_req *cqr, *next;
 226         struct dasd_device *device;
 227         unsigned long long expires;
 228         unsigned long flags;
 229         u8 int_code, status;
 230         addr_t ip;
 231         int rc;
 232
 233         int_code = *((u8 *) DASD_DIAG_LC_INT_CODE);
 234         status = *((u8 *) DASD_DIAG_LC_INT_STATUS);
 235         switch (int_code) {
 236         case DASD_DIAG_CODE_31BIT:
 237                 ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT);
 238                 break;
 239         case DASD_DIAG_CODE_64BIT:
 240                 ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT);
 241                 break;
 242         default:
 243                 return;
 244         }
 245         if (!ip) {              /* no intparm: unsolicited interrupt */
 246                 MESSAGE(KERN_DEBUG, "%s", "caught unsolicited interrupt");
 247                 return;
 248         }
 249         cqr = (struct dasd_ccw_req *) ip;
 250         device = (struct dasd_device *) cqr->device;
 251         if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 252                 DEV_MESSAGE(KERN_WARNING, device,
 253                             " magic number of dasd_ccw_req 0x%08X doesn't"
 254                             " match discipline 0x%08X",
 255                             cqr->magic, *(int *) (&device->discipline->name));
 256                 return;
 257         }
 258
 259         /* get irq lock to modify request queue */
 260         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 261
 262         /* Check for a pending clear operation */
 263         if (cqr->status == DASD_CQR_CLEAR) {
 264                 cqr->status = DASD_CQR_QUEUED;
 265                 dasd_clear_timer(device);
 266                 dasd_schedule_bh(device);
 267                 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 268                 return;
 269         }
 270
 271         cqr->stopclk = get_clock();
 272
 273         expires = 0;
 274         if (status == 0) {
 275                 cqr->status = DASD_CQR_DONE;
 276                 /* Start first request on queue if possible -> fast_io. */
 277                 if (!list_empty(&device->ccw_queue)) {
 278                         next = list_entry(device->ccw_queue.next,
 279                                           struct dasd_ccw_req, list);
 280                         if (next->status == DASD_CQR_QUEUED) {
 281                                 rc = dasd_start_diag(next);
 282                                 if (rc == 0)
 283                                         expires = next->expires;
 284                                 else if (rc != -EACCES)
 285                                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 286                                                     "Interrupt fastpath "
 287                                                     "failed!");
 288                         }
 289                 }
 290         } else {
 291                 cqr->status = DASD_CQR_QUEUED;
 292                 DEV_MESSAGE(KERN_WARNING, device, "interrupt status for "
 293                             "request %p was %d (%d retries left)", cqr, status,
 294                             cqr->retries);
 295                 dasd_diag_erp(device);
 296         }
 297
 298         if (expires != 0)
 299                 dasd_set_timer(device, expires);
 300         else
 301                 dasd_clear_timer(device);
 302         dasd_schedule_bh(device);
 303
 304         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 305 }
 306
 307 /* Check whether device can be controlled by DIAG discipline. Return zero on
 308  * success, non-zero otherwise. */
 309 static int
 310 dasd_diag_check_device(struct dasd_device *device)
 311 {
 312         struct dasd_diag_private *private;
 313         struct dasd_diag_characteristics *rdc_data;
 314         struct dasd_diag_bio bio;
 315         struct vtoc_cms_label *label;
 316         blocknum_t end_block;
 317         unsigned int sb, bsize;
 318         int rc;
 319
 320         private = (struct dasd_diag_private *) device->private;
 321         if (private == NULL) {
 322                 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
 323                 if (private == NULL) {
 324                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 325                                 "memory allocation failed for private data");
 326                         return -ENOMEM;
 327                 }
 328                 ccw_device_get_id(device->cdev, &private->dev_id);
 329                 device->private = (void *) private;
 330         }
 331         /* Read Device Characteristics */
 332         rdc_data = (void *) &(private->rdc_data);
 333         rdc_data->dev_nr = private->dev_id.devno;
 334         rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
 335
 336         rc = diag210((struct diag210 *) rdc_data);
 337         if (rc) {
 338                 DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "
 339                             "information (rc=%d)", rc);
 340                 return -ENOTSUPP;
 341         }
 342
 343         /* Figure out position of label block */
 344         switch (private->rdc_data.vdev_class) {
 345         case DEV_CLASS_FBA:
 346                 private->pt_block = 1;
 347                 break;
 348         case DEV_CLASS_ECKD:
 349                 private->pt_block = 2;
 350                 break;
 351         default:
 352                 DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "
 353                             "(class=%d)", private->rdc_data.vdev_class);
 354                 return -ENOTSUPP;
 355         }
 356
 357         DBF_DEV_EVENT(DBF_INFO, device,
 358                       "%04X: %04X on real %04X/%02X",
 359                       rdc_data->dev_nr,
 360                       rdc_data->vdev_type,
 361                       rdc_data->rdev_type, rdc_data->rdev_model);
 362
 363         /* terminate all outstanding operations */
 364         mdsk_term_io(device);
 365
 366         /* figure out blocksize of device */
 367         label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
 368         if (label == NULL)  {
 369                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 370                             "No memory to allocate initialization request");
 371                 return -ENOMEM;
 372         }
 373         rc = 0;
 374         end_block = 0;
 375         /* try all sizes - needed for ECKD devices */
 376         for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
 377                 mdsk_init_io(device, bsize, 0, &end_block);
 378                 memset(&bio, 0, sizeof (struct dasd_diag_bio));
 379                 bio.type = MDSK_READ_REQ;
 380                 bio.block_number = private->pt_block + 1;
 381                 bio.buffer = label;
 382                 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
 383                 private->iob.dev_nr = rdc_data->dev_nr;
 384                 private->iob.key = 0;
 385                 private->iob.flags = 0; /* do synchronous io */
 386                 private->iob.block_count = 1;
 387                 private->iob.interrupt_params = 0;
 388                 private->iob.bio_list = &bio;
 389                 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
 390                 rc = dia250(&private->iob, RW_BIO);
 391                 if (rc == 3) {
 392                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 393                                 "DIAG call failed");
 394                         rc = -EOPNOTSUPP;
 395                         goto out;
 396                 }
 397                 mdsk_term_io(device);
 398                 if (rc == 0)
 399                         break;
 400         }
 401         if (bsize > PAGE_SIZE) {
 402                 DEV_MESSAGE(KERN_WARNING, device, "device access failed "
 403                             "(rc=%d)", rc);
 404                 rc = -EIO;
 405                 goto out;
 406         }
 407         /* check for label block */
 408         if (memcmp(label->label_id, DASD_DIAG_CMS1,
 409                   sizeof(DASD_DIAG_CMS1)) == 0) {
 410                 /* get formatted blocksize from label block */
 411                 bsize = (unsigned int) label->block_size;
 412                 device->blocks = (unsigned long) label->block_count;
 413         } else
 414                 device->blocks = end_block;
 415         device->bp_block = bsize;
 416         device->s2b_shift = 0;  /* bits to shift 512 to get a block */
 417         for (sb = 512; sb < bsize; sb = sb << 1)
 418                 device->s2b_shift++;
 419         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
 420         if (rc) {
 421                 DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization "
 422                         "failed (rc=%d)", rc);
 423                 rc = -EIO;
 424         } else {
 425                 DEV_MESSAGE(KERN_INFO, device,
 426                             "(%ld B/blk): %ldkB",
 427                             (unsigned long) device->bp_block,
 428                             (unsigned long) (device->blocks <<
 429                                 device->s2b_shift) >> 1);
 430         }
 431 out:
 432         free_page((long) label);
 433         return rc;
 434 }
 435
 436 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
 437  * otherwise. */
 438 static int
 439 dasd_diag_fill_geometry(struct dasd_device *device, struct hd_geometry *geo)
 440 {
 441         if (dasd_check_blocksize(device->bp_block) != 0)
 442                 return -EINVAL;
 443         geo->cylinders = (device->blocks << device->s2b_shift) >> 10;
 444         geo->heads = 16;
 445         geo->sectors = 128 >> device->s2b_shift;
 446         return 0;
 447 }
 448
 449 static dasd_era_t
 450 dasd_diag_examine_error(struct dasd_ccw_req * cqr, struct irb * stat)
 451 {
 452         return dasd_era_fatal;
 453 }
 454
 455 static dasd_erp_fn_t
 456 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
 457 {
 458         return dasd_default_erp_action;
 459 }
 460
 461 static dasd_erp_fn_t
 462 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
 463 {
 464         return dasd_default_erp_postaction;
 465 }
 466
 467 /* Create DASD request from block device request. Return pointer to new
 468  * request on success, ERR_PTR otherwise. */
 469 static struct dasd_ccw_req *
 470 dasd_diag_build_cp(struct dasd_device * device, struct request *req)
 471 {
 472         struct dasd_ccw_req *cqr;
 473         struct dasd_diag_req *dreq;
 474         struct dasd_diag_bio *dbio;
 475         struct req_iterator iter;
 476         struct bio_vec *bv;
 477         char *dst;
 478         unsigned int count, datasize;
 479         sector_t recid, first_rec, last_rec;
 480         unsigned int blksize, off;
 481         unsigned char rw_cmd;
 482
 483         if (rq_data_dir(req) == READ)
 484                 rw_cmd = MDSK_READ_REQ;
 485         else if (rq_data_dir(req) == WRITE)
 486                 rw_cmd = MDSK_WRITE_REQ;
 487         else
 488                 return ERR_PTR(-EINVAL);
 489         blksize = device->bp_block;
 490         /* Calculate record id of first and last block. */
 491         first_rec = req->sector >> device->s2b_shift;
 492         last_rec = (req->sector + req->nr_sectors - 1) >> device->s2b_shift;
 493         /* Check struct bio and count the number of blocks for the request. */
 494         count = 0;
 495         rq_for_each_segment(bv, req, iter) {
 496                 if (bv->bv_len & (blksize - 1))
 497                         /* Fba can only do full blocks. */
 498                         return ERR_PTR(-EINVAL);
 499                 count += bv->bv_len >> (device->s2b_shift + 9);
 500         }
 501         /* Paranoia. */
 502         if (count != last_rec - first_rec + 1)
 503                 return ERR_PTR(-EINVAL);
 504         /* Build the request */
 505         datasize = sizeof(struct dasd_diag_req) +
 506                 count*sizeof(struct dasd_diag_bio);
 507         cqr = dasd_smalloc_request(dasd_diag_discipline.name, 0,
 508                                    datasize, device);
 509         if (IS_ERR(cqr))
 510                 return cqr;
 511
 512         dreq = (struct dasd_diag_req *) cqr->data;
 513         dreq->block_count = count;
 514         dbio = dreq->bio;
 515         recid = first_rec;
 516         rq_for_each_segment(bv, req, iter) {
 517                 dst = page_address(bv->bv_page) + bv->bv_offset;
 518                 for (off = 0; off < bv->bv_len; off += blksize) {
 519                         memset(dbio, 0, sizeof (struct dasd_diag_bio));
 520                         dbio->type = rw_cmd;
 521                         dbio->block_number = recid + 1;
 522                         dbio->buffer = dst;
 523                         dbio++;
 524                         dst += blksize;
 525                         recid++;
 526                 }
 527         }
 528         cqr->retries = DIAG_MAX_RETRIES;
 529         cqr->buildclk = get_clock();
 530         if (req->cmd_flags & REQ_FAILFAST)
 531                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
 532         cqr->device = device;
 533         cqr->expires = DIAG_TIMEOUT;
 534         cqr->status = DASD_CQR_FILLED;
 535         return cqr;
 536 }
 537
 538 /* Release DASD request. Return non-zero if request was successful, zero
 539  * otherwise. */
 540 static int
 541 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
 542 {
 543         int status;
 544
 545         status = cqr->status == DASD_CQR_DONE;
 546         dasd_sfree_request(cqr, cqr->device);
 547         return status;
 548 }
 549
 550 /* Fill in IOCTL data for device. */
 551 static int
 552 dasd_diag_fill_info(struct dasd_device * device,
 553                     struct dasd_information2_t * info)
 554 {
 555         struct dasd_diag_private *private;
 556
 557         private = (struct dasd_diag_private *) device->private;
 558         info->label_block = (unsigned int) private->pt_block;
 559         info->FBA_layout = 1;
 560         info->format = DASD_FORMAT_LDL;
 561         info->characteristics_size = sizeof (struct dasd_diag_characteristics);
 562         memcpy(info->characteristics,
 563                &((struct dasd_diag_private *) device->private)->rdc_data,
 564                sizeof (struct dasd_diag_characteristics));
 565         info->confdata_size = 0;
 566         return 0;
 567 }
 568
 569 static void
 570 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
 571                      struct irb *stat)
 572 {
 573         DEV_MESSAGE(KERN_ERR, device, "%s",
 574                     "dump sense not available for DIAG data");
 575 }
 576
 577 static struct dasd_discipline dasd_diag_discipline = {
 578         .owner = THIS_MODULE,
 579         .name = "DIAG",
 580         .ebcname = "DIAG",
 581         .max_blocks = DIAG_MAX_BLOCKS,
 582         .check_device = dasd_diag_check_device,
 583         .fill_geometry = dasd_diag_fill_geometry,
 584         .start_IO = dasd_start_diag,
 585         .term_IO = dasd_diag_term_IO,
 586         .examine_error = dasd_diag_examine_error,
 587         .erp_action = dasd_diag_erp_action,
 588         .erp_postaction = dasd_diag_erp_postaction,
 589         .build_cp = dasd_diag_build_cp,
 590         .free_cp = dasd_diag_free_cp,
 591         .dump_sense = dasd_diag_dump_sense,
 592         .fill_info = dasd_diag_fill_info,
 593 };
 594
 595 static int __init
 596 dasd_diag_init(void)
 597 {
 598         if (!MACHINE_IS_VM) {
 599                 MESSAGE_LOG(KERN_INFO,
 600                             "Machine is not VM: %s "
 601                             "discipline not initializing",
 602                             dasd_diag_discipline.name);
 603                 return -ENODEV;
 604         }
 605         ASCEBC(dasd_diag_discipline.ebcname, 4);
 606
 607         ctl_set_bit(0, 9);
 608         register_external_interrupt(0x2603, dasd_ext_handler);
 609         dasd_diag_discipline_pointer = &dasd_diag_discipline;
 610         return 0;
 611 }
 612
 613 static void __exit
 614 dasd_diag_cleanup(void)
 615 {
 616         unregister_external_interrupt(0x2603, dasd_ext_handler);
 617         ctl_clear_bit(0, 9);
 618         dasd_diag_discipline_pointer = NULL;
 619 }
 620
 621 module_init(dasd_diag_init);
 622 module_exit(dasd_diag_cleanup);