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
  28 #include "dasd_int.h"
  29 #include "dasd_diag.h"
  30
  31 #define PRINTK_HEADER "dasd(diag):"
  32
  33 MODULE_LICENSE("GPL");
  34
  35 /* The maximum number of blocks per request (max_blocks) is dependent on the
  36  * amount of storage that is available in the static I/O buffer for each
  37  * device. Currently each device gets 2 pages. We want to fit two requests
  38  * into the available memory so that we can immediately start the next if one
  39  * finishes. */
  40 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
  41                            sizeof(struct dasd_diag_req)) / \
  42                            sizeof(struct dasd_diag_bio)) / 2)
  43 #define DIAG_MAX_RETRIES        32
  44 #define DIAG_TIMEOUT            50 * HZ
  45
  46 static struct dasd_discipline dasd_diag_discipline;
  47
  48 struct dasd_diag_private {
  49         struct dasd_diag_characteristics rdc_data;
  50         struct dasd_diag_rw_io iob;
  51         struct dasd_diag_init_io iib;
  52         blocknum_t pt_block;
  53         struct ccw_dev_id dev_id;
  54 };
  55
  56 struct dasd_diag_req {
  57         unsigned int block_count;
  58         struct dasd_diag_bio bio[0];
  59 };
  60
  61 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
  62
  63 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
  64  * and function code cmd.
  65  * In case of an exception return 3. Otherwise return result of bitwise OR of
  66  * resulting condition code and DIAG return code. */
  67 static inline int dia250(void *iob, int cmd)
  68 {
  69         register unsigned long reg2 asm ("2") = (unsigned long) iob;
  70         typedef union {
  71                 struct dasd_diag_init_io init_io;
  72                 struct dasd_diag_rw_io rw_io;
  73         } addr_type;
  74         int rc;
  75
  76         rc = 3;
  77         asm volatile(
  78                 "       diag    2,%2,0x250\n"
  79                 "0:     ipm     %0\n"
  80                 "       srl     %0,28\n"
  81                 "       or      %0,3\n"
  82                 "1:\n"
  83                 EX_TABLE(0b,1b)
  84                 : "+d" (rc), "=m" (*(addr_type *) iob)
  85                 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
  86                 : "3", "cc");
  87         return rc;
  88 }
  89
  90 /* Initialize block I/O to DIAG device using the specified blocksize and
  91  * block offset. On success, return zero and set end_block to contain the
  92  * number of blocks on the device minus the specified offset. Return non-zero
  93  * otherwise. */
  94 static inline int
  95 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
  96              blocknum_t offset, blocknum_t *end_block)
  97 {
  98         struct dasd_diag_private *private;
  99         struct dasd_diag_init_io *iib;
 100         int rc;
 101
 102         private = (struct dasd_diag_private *) device->private;
 103         iib = &private->iib;
 104         memset(iib, 0, sizeof (struct dasd_diag_init_io));
 105
 106         iib->dev_nr = private->dev_id.devno;
 107         iib->block_size = blocksize;
 108         iib->offset = offset;
 109         iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
 110
 111         rc = dia250(iib, INIT_BIO);
 112
 113         if ((rc & 3) == 0 && end_block)
 114                 *end_block = iib->end_block;
 115
 116         return rc;
 117 }
 118
 119 /* Remove block I/O environment for device. Return zero on success, non-zero
 120  * otherwise. */
 121 static inline int
 122 mdsk_term_io(struct dasd_device * device)
 123 {
 124         struct dasd_diag_private *private;
 125         struct dasd_diag_init_io *iib;
 126         int rc;
 127
 128         private = (struct dasd_diag_private *) device->private;
 129         iib = &private->iib;
 130         memset(iib, 0, sizeof (struct dasd_diag_init_io));
 131         iib->dev_nr = private->dev_id.devno;
 132         rc = dia250(iib, TERM_BIO);
 133         return rc;
 134 }
 135
 136 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
 137  * environment. */
 138 static void
 139 dasd_diag_erp(struct dasd_device *device)
 140 {
 141         int rc;
 142
 143         mdsk_term_io(device);
 144         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
 145         if (rc)
 146                 DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, "
 147                             "rc=%d", rc);
 148 }
 149
 150 /* Start a given request at the device. Return zero on success, non-zero
 151  * otherwise. */
 152 static int
 153 dasd_start_diag(struct dasd_ccw_req * cqr)
 154 {
 155         struct dasd_device *device;
 156         struct dasd_diag_private *private;
 157         struct dasd_diag_req *dreq;
 158         int rc;
 159
 160         device = cqr->device;
 161         if (cqr->retries < 0) {
 162                 DEV_MESSAGE(KERN_WARNING, device, "DIAG start_IO: request %p "
 163                             "- no retry left)", cqr);
 164                 cqr->status = DASD_CQR_FAILED;
 165                 return -EIO;
 166         }
 167         private = (struct dasd_diag_private *) device->private;
 168         dreq = (struct dasd_diag_req *) cqr->data;
 169
 170         private->iob.dev_nr = private->dev_id.devno;
 171         private->iob.key = 0;
 172         private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
 173         private->iob.block_count = dreq->block_count;
 174         private->iob.interrupt_params = (addr_t) cqr;
 175         private->iob.bio_list = dreq->bio;
 176         private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
 177
 178         cqr->startclk = get_clock();
 179         cqr->starttime = jiffies;
 180         cqr->retries--;
 181
 182         rc = dia250(&private->iob, RW_BIO);
 183         switch (rc) {
 184         case 0: /* Synchronous I/O finished successfully */
 185                 cqr->stopclk = get_clock();
 186                 cqr->status = DASD_CQR_DONE;
 187                 /* Indicate to calling function that only a dasd_schedule_bh()
 188                    and no timer is needed */
 189                 rc = -EACCES;
 190                 break;
 191         case 8: /* Asynchronous I/O was started */
 192                 cqr->status = DASD_CQR_IN_IO;
 193                 rc = 0;
 194                 break;
 195         default: /* Error condition */
 196                 cqr->status = DASD_CQR_QUEUED;
 197                 DEV_MESSAGE(KERN_WARNING, device, "dia250 returned rc=%d", rc);
 198                 dasd_diag_erp(device);
 199                 rc = -EIO;
 200                 break;
 201         }
 202         return rc;
 203 }
 204
 205 /* Terminate given request at the device. */
 206 static int
 207 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
 208 {
 209         struct dasd_device *device;
 210
 211         device = cqr->device;
 212         mdsk_term_io(device);
 213         mdsk_init_io(device, device->bp_block, 0, NULL);
 214         cqr->status = DASD_CQR_CLEAR;
 215         cqr->stopclk = get_clock();
 216         dasd_schedule_bh(device);
 217         return 0;
 218 }
 219
 220 /* Handle external interruption. */
 221 static void
 222 dasd_ext_handler(__u16 code)
 223 {
 224         struct dasd_ccw_req *cqr, *next;
 225         struct dasd_device *device;
 226         unsigned long long expires;
 227         unsigned long flags;
 228         u8 int_code, status;
 229         addr_t ip;
 230         int rc;
 231
 232         int_code = *((u8 *) DASD_DIAG_LC_INT_CODE);
 233         status = *((u8 *) DASD_DIAG_LC_INT_STATUS);
 234         switch (int_code) {
 235         case DASD_DIAG_CODE_31BIT:
 236                 ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT);
 237                 break;
 238         case DASD_DIAG_CODE_64BIT:
 239                 ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT);
 240                 break;
 241         default:
 242                 return;
 243         }
 244         if (!ip) {              /* no intparm: unsolicited interrupt */
 245                 MESSAGE(KERN_DEBUG, "%s", "caught unsolicited interrupt");
 246                 return;
 247         }
 248         cqr = (struct dasd_ccw_req *) ip;
 249         device = (struct dasd_device *) cqr->device;
 250         if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
 251                 DEV_MESSAGE(KERN_WARNING, device,
 252                             " magic number of dasd_ccw_req 0x%08X doesn't"
 253                             " match discipline 0x%08X",
 254                             cqr->magic, *(int *) (&device->discipline->name));
 255                 return;
 256         }
 257
 258         /* get irq lock to modify request queue */
 259         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 260
 261         /* Check for a pending clear operation */
 262         if (cqr->status == DASD_CQR_CLEAR) {
 263                 cqr->status = DASD_CQR_QUEUED;
 264                 dasd_clear_timer(device);
 265                 dasd_schedule_bh(device);
 266                 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 267                 return;
 268         }
 269
 270         cqr->stopclk = get_clock();
 271
 272         expires = 0;
 273         if (status == 0) {
 274                 cqr->status = DASD_CQR_DONE;
 275                 /* Start first request on queue if possible -> fast_io. */
 276                 if (!list_empty(&device->ccw_queue)) {
 277                         next = list_entry(device->ccw_queue.next,
 278                                           struct dasd_ccw_req, list);
 279                         if (next->status == DASD_CQR_QUEUED) {
 280                                 rc = dasd_start_diag(next);
 281                                 if (rc == 0)
 282                                         expires = next->expires;
 283                                 else if (rc != -EACCES)
 284                                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 285                                                     "Interrupt fastpath "
 286                                                     "failed!");
 287                         }
 288                 }
 289         } else {
 290                 cqr->status = DASD_CQR_QUEUED;
 291                 DEV_MESSAGE(KERN_WARNING, device, "interrupt status for "
 292                             "request %p was %d (%d retries left)", cqr, status,
 293                             cqr->retries);
 294                 dasd_diag_erp(device);
 295         }
 296
 297         if (expires != 0)
 298                 dasd_set_timer(device, expires);
 299         else
 300                 dasd_clear_timer(device);
 301         dasd_schedule_bh(device);
 302
 303         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 304 }
 305
 306 /* Check whether device can be controlled by DIAG discipline. Return zero on
 307  * success, non-zero otherwise. */
 308 static int
 309 dasd_diag_check_device(struct dasd_device *device)
 310 {
 311         struct dasd_diag_private *private;
 312         struct dasd_diag_characteristics *rdc_data;
 313         struct dasd_diag_bio bio;
 314         struct vtoc_cms_label *label;
 315         blocknum_t end_block;
 316         unsigned int sb, bsize;
 317         int rc;
 318
 319         private = (struct dasd_diag_private *) device->private;
 320         if (private == NULL) {
 321                 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
 322                 if (private == NULL) {
 323                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 324                                 "memory allocation failed for private data");
 325                         return -ENOMEM;
 326                 }
 327                 ccw_device_get_id(device->cdev, &private->dev_id);
 328                 device->private = (void *) private;
 329         }
 330         /* Read Device Characteristics */
 331         rdc_data = (void *) &(private->rdc_data);
 332         rdc_data->dev_nr = private->dev_id.devno;
 333         rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
 334
 335         rc = diag210((struct diag210 *) rdc_data);
 336         if (rc) {
 337                 DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "
 338                             "information (rc=%d)", rc);
 339                 return -ENOTSUPP;
 340         }
 341
 342         /* Figure out position of label block */
 343         switch (private->rdc_data.vdev_class) {
 344         case DEV_CLASS_FBA:
 345                 private->pt_block = 1;
 346                 break;
 347         case DEV_CLASS_ECKD:
 348                 private->pt_block = 2;
 349                 break;
 350         default:
 351                 DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "
 352                             "(class=%d)", private->rdc_data.vdev_class);
 353                 return -ENOTSUPP;
 354         }
 355
 356         DBF_DEV_EVENT(DBF_INFO, device,
 357                       "%04X: %04X on real %04X/%02X",
 358                       rdc_data->dev_nr,
 359                       rdc_data->vdev_type,
 360                       rdc_data->rdev_type, rdc_data->rdev_model);
 361
 362         /* terminate all outstanding operations */
 363         mdsk_term_io(device);
 364
 365         /* figure out blocksize of device */
 366         label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
 367         if (label == NULL)  {
 368                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 369                             "No memory to allocate initialization request");
 370                 return -ENOMEM;
 371         }
 372         rc = 0;
 373         end_block = 0;
 374         /* try all sizes - needed for ECKD devices */
 375         for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
 376                 mdsk_init_io(device, bsize, 0, &end_block);
 377                 memset(&bio, 0, sizeof (struct dasd_diag_bio));
 378                 bio.type = MDSK_READ_REQ;
 379                 bio.block_number = private->pt_block + 1;
 380                 bio.buffer = label;
 381                 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
 382                 private->iob.dev_nr = rdc_data->dev_nr;
 383                 private->iob.key = 0;
 384                 private->iob.flags = 0; /* do synchronous io */
 385                 private->iob.block_count = 1;
 386                 private->iob.interrupt_params = 0;
 387                 private->iob.bio_list = &bio;
 388                 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
 389                 rc = dia250(&private->iob, RW_BIO);
 390                 if (rc == 3) {
 391                         DEV_MESSAGE(KERN_WARNING, device, "%s",
 392                                 "DIAG call failed");
 393                         rc = -EOPNOTSUPP;
 394                         goto out;
 395                 }
 396                 mdsk_term_io(device);
 397                 if (rc == 0)
 398                         break;
 399         }
 400         if (bsize > PAGE_SIZE) {
 401                 DEV_MESSAGE(KERN_WARNING, device, "device access failed "
 402                             "(rc=%d)", rc);
 403                 rc = -EIO;
 404                 goto out;
 405         }
 406         /* check for label block */
 407         if (memcmp(label->label_id, DASD_DIAG_CMS1,
 408                   sizeof(DASD_DIAG_CMS1)) == 0) {
 409                 /* get formatted blocksize from label block */
 410                 bsize = (unsigned int) label->block_size;
 411                 device->blocks = (unsigned long) label->block_count;
 412         } else
 413                 device->blocks = end_block;
 414         device->bp_block = bsize;
 415         device->s2b_shift = 0;  /* bits to shift 512 to get a block */
 416         for (sb = 512; sb < bsize; sb = sb << 1)
 417                 device->s2b_shift++;
 418         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
 419         if (rc) {
 420                 DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization "
 421                         "failed (rc=%d)", rc);
 422                 rc = -EIO;
 423         } else {
 424                 DEV_MESSAGE(KERN_INFO, device,
 425                             "(%ld B/blk): %ldkB",
 426                             (unsigned long) device->bp_block,
 427                             (unsigned long) (device->blocks <<
 428                                 device->s2b_shift) >> 1);
 429         }
 430 out:
 431         free_page((long) label);
 432         return rc;
 433 }
 434
 435 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
 436  * otherwise. */
 437 static int
 438 dasd_diag_fill_geometry(struct dasd_device *device, struct hd_geometry *geo)
 439 {
 440         if (dasd_check_blocksize(device->bp_block) != 0)
 441                 return -EINVAL;
 442         geo->cylinders = (device->blocks << device->s2b_shift) >> 10;
 443         geo->heads = 16;
 444         geo->sectors = 128 >> device->s2b_shift;
 445         return 0;
 446 }
 447
 448 static dasd_era_t
 449 dasd_diag_examine_error(struct dasd_ccw_req * cqr, struct irb * stat)
 450 {
 451         return dasd_era_fatal;
 452 }
 453
 454 static dasd_erp_fn_t
 455 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
 456 {
 457         return dasd_default_erp_action;
 458 }
 459
 460 static dasd_erp_fn_t
 461 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
 462 {
 463         return dasd_default_erp_postaction;
 464 }
 465
 466 /* Create DASD request from block device request. Return pointer to new
 467  * request on success, ERR_PTR otherwise. */
 468 static struct dasd_ccw_req *
 469 dasd_diag_build_cp(struct dasd_device * device, struct request *req)
 470 {
 471         struct dasd_ccw_req *cqr;
 472         struct dasd_diag_req *dreq;
 473         struct dasd_diag_bio *dbio;
 474         struct bio *bio;
 475         struct bio_vec *bv;
 476         char *dst;
 477         unsigned int count, datasize;
 478         sector_t recid, first_rec, last_rec;
 479         unsigned int blksize, off;
 480         unsigned char rw_cmd;
 481         int i;
 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_bio(bio, req) {
 496                 bio_for_each_segment(bv, bio, i) {
 497                         if (bv->bv_len & (blksize - 1))
 498                                 /* Fba can only do full blocks. */
 499                                 return ERR_PTR(-EINVAL);
 500                         count += bv->bv_len >> (device->s2b_shift + 9);
 501                 }
 502         }
 503         /* Paranoia. */
 504         if (count != last_rec - first_rec + 1)
 505                 return ERR_PTR(-EINVAL);
 506         /* Build the request */
 507         datasize = sizeof(struct dasd_diag_req) +
 508                 count*sizeof(struct dasd_diag_bio);
 509         cqr = dasd_smalloc_request(dasd_diag_discipline.name, 0,
 510                                    datasize, device);
 511         if (IS_ERR(cqr))
 512                 return cqr;
 513
 514         dreq = (struct dasd_diag_req *) cqr->data;
 515         dreq->block_count = count;
 516         dbio = dreq->bio;
 517         recid = first_rec;
 518         rq_for_each_bio(bio, req) {
 519                 bio_for_each_segment(bv, bio, i) {
 520                         dst = page_address(bv->bv_page) + bv->bv_offset;
 521                         for (off = 0; off < bv->bv_len; off += blksize) {
 522                                 memset(dbio, 0, sizeof (struct dasd_diag_bio));
 523                                 dbio->type = rw_cmd;
 524                                 dbio->block_number = recid + 1;
 525                                 dbio->buffer = dst;
 526                                 dbio++;
 527                                 dst += blksize;
 528                                 recid++;
 529                         }
 530                 }
 531         }
 532         cqr->retries = DIAG_MAX_RETRIES;
 533         cqr->buildclk = get_clock();
 534         if (req->cmd_flags & REQ_FAILFAST)
 535                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
 536         cqr->device = device;
 537         cqr->expires = DIAG_TIMEOUT;
 538         cqr->status = DASD_CQR_FILLED;
 539         return cqr;
 540 }
 541
 542 /* Release DASD request. Return non-zero if request was successful, zero
 543  * otherwise. */
 544 static int
 545 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
 546 {
 547         int status;
 548
 549         status = cqr->status == DASD_CQR_DONE;
 550         dasd_sfree_request(cqr, cqr->device);
 551         return status;
 552 }
 553
 554 /* Fill in IOCTL data for device. */
 555 static int
 556 dasd_diag_fill_info(struct dasd_device * device,
 557                     struct dasd_information2_t * info)
 558 {
 559         struct dasd_diag_private *private;
 560
 561         private = (struct dasd_diag_private *) device->private;
 562         info->label_block = (unsigned int) private->pt_block;
 563         info->FBA_layout = 1;
 564         info->format = DASD_FORMAT_LDL;
 565         info->characteristics_size = sizeof (struct dasd_diag_characteristics);
 566         memcpy(info->characteristics,
 567                &((struct dasd_diag_private *) device->private)->rdc_data,
 568                sizeof (struct dasd_diag_characteristics));
 569         info->confdata_size = 0;
 570         return 0;
 571 }
 572
 573 static void
 574 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
 575                      struct irb *stat)
 576 {
 577         DEV_MESSAGE(KERN_ERR, device, "%s",
 578                     "dump sense not available for DIAG data");
 579 }
 580
 581 static struct dasd_discipline dasd_diag_discipline = {
 582         .owner = THIS_MODULE,
 583         .name = "DIAG",
 584         .ebcname = "DIAG",
 585         .max_blocks = DIAG_MAX_BLOCKS,
 586         .check_device = dasd_diag_check_device,
 587         .fill_geometry = dasd_diag_fill_geometry,
 588         .start_IO = dasd_start_diag,
 589         .term_IO = dasd_diag_term_IO,
 590         .examine_error = dasd_diag_examine_error,
 591         .erp_action = dasd_diag_erp_action,
 592         .erp_postaction = dasd_diag_erp_postaction,
 593         .build_cp = dasd_diag_build_cp,
 594         .free_cp = dasd_diag_free_cp,
 595         .dump_sense = dasd_diag_dump_sense,
 596         .fill_info = dasd_diag_fill_info,
 597 };
 598
 599 static int __init
 600 dasd_diag_init(void)
 601 {
 602         if (!MACHINE_IS_VM) {
 603                 MESSAGE_LOG(KERN_INFO,
 604                             "Machine is not VM: %s "
 605                             "discipline not initializing",
 606                             dasd_diag_discipline.name);
 607                 return -ENODEV;
 608         }
 609         ASCEBC(dasd_diag_discipline.ebcname, 4);
 610
 611         ctl_set_bit(0, 9);
 612         register_external_interrupt(0x2603, dasd_ext_handler);
 613         dasd_diag_discipline_pointer = &dasd_diag_discipline;
 614         return 0;
 615 }
 616
 617 static void __exit
 618 dasd_diag_cleanup(void)
 619 {
 620         unregister_external_interrupt(0x2603, dasd_ext_handler);
 621         ctl_clear_bit(0, 9);
 622         dasd_diag_discipline_pointer = NULL;
 623 }
 624
 625 module_init(dasd_diag_init);
 626 module_exit(dasd_diag_cleanup);