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 #define KMSG_COMPONENT "dasd" 12 13 #include <linux/kernel_stat.h> 14 #include <linux/stddef.h> 15 #include <linux/kernel.h> 16 #include <linux/slab.h> 17 #include <linux/hdreg.h> 18 #include <linux/bio.h> 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/jiffies.h> 22 23 #include <asm/dasd.h> 24 #include <asm/debug.h> 25 #include <asm/ebcdic.h> 26 #include <asm/io.h> 27 #include <asm/irq.h> 28 #include <asm/vtoc.h> 29 #include <asm/diag.h> 30 31 #include "dasd_int.h" 32 #include "dasd_diag.h" 33 34 #define PRINTK_HEADER "dasd(diag):" 35 36 MODULE_LICENSE("GPL"); 37 38 /* The maximum number of blocks per request (max_blocks) is dependent on the 39 * amount of storage that is available in the static I/O buffer for each 40 * device. Currently each device gets 2 pages. We want to fit two requests 41 * into the available memory so that we can immediately start the next if one 42 * finishes. */ 43 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \ 44 sizeof(struct dasd_diag_req)) / \ 45 sizeof(struct dasd_diag_bio)) / 2) 46 #define DIAG_MAX_RETRIES 32 47 #define DIAG_TIMEOUT 50 48 49 static struct dasd_discipline dasd_diag_discipline; 50 51 struct dasd_diag_private { 52 struct dasd_diag_characteristics rdc_data; 53 struct dasd_diag_rw_io iob; 54 struct dasd_diag_init_io iib; 55 blocknum_t pt_block; 56 struct ccw_dev_id dev_id; 57 }; 58 59 struct dasd_diag_req { 60 unsigned int block_count; 61 struct dasd_diag_bio bio[0]; 62 }; 63 64 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */ 65 66 /* Perform DIAG250 call with block I/O parameter list iob (input and output) 67 * and function code cmd. 68 * In case of an exception return 3. Otherwise return result of bitwise OR of 69 * resulting condition code and DIAG return code. */ 70 static inline int dia250(void *iob, int cmd) 71 { 72 register unsigned long reg2 asm ("2") = (unsigned long) iob; 73 typedef union { 74 struct dasd_diag_init_io init_io; 75 struct dasd_diag_rw_io rw_io; 76 } addr_type; 77 int rc; 78 79 rc = 3; 80 asm volatile( 81 " diag 2,%2,0x250\n" 82 "0: ipm %0\n" 83 " srl %0,28\n" 84 " or %0,3\n" 85 "1:\n" 86 EX_TABLE(0b,1b) 87 : "+d" (rc), "=m" (*(addr_type *) iob) 88 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob) 89 : "3", "cc"); 90 return rc; 91 } 92 93 /* Initialize block I/O to DIAG device using the specified blocksize and 94 * block offset. On success, return zero and set end_block to contain the 95 * number of blocks on the device minus the specified offset. Return non-zero 96 * otherwise. */ 97 static inline int 98 mdsk_init_io(struct dasd_device *device, unsigned int blocksize, 99 blocknum_t offset, blocknum_t *end_block) 100 { 101 struct dasd_diag_private *private; 102 struct dasd_diag_init_io *iib; 103 int rc; 104 105 private = (struct dasd_diag_private *) device->private; 106 iib = &private->iib; 107 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 108 109 iib->dev_nr = private->dev_id.devno; 110 iib->block_size = blocksize; 111 iib->offset = offset; 112 iib->flaga = DASD_DIAG_FLAGA_DEFAULT; 113 114 rc = dia250(iib, INIT_BIO); 115 116 if ((rc & 3) == 0 && end_block) 117 *end_block = iib->end_block; 118 119 return rc; 120 } 121 122 /* Remove block I/O environment for device. Return zero on success, non-zero 123 * otherwise. */ 124 static inline int 125 mdsk_term_io(struct dasd_device * device) 126 { 127 struct dasd_diag_private *private; 128 struct dasd_diag_init_io *iib; 129 int rc; 130 131 private = (struct dasd_diag_private *) device->private; 132 iib = &private->iib; 133 memset(iib, 0, sizeof (struct dasd_diag_init_io)); 134 iib->dev_nr = private->dev_id.devno; 135 rc = dia250(iib, TERM_BIO); 136 return rc; 137 } 138 139 /* Error recovery for failed DIAG requests - try to reestablish the DIAG 140 * environment. */ 141 static void 142 dasd_diag_erp(struct dasd_device *device) 143 { 144 int rc; 145 146 mdsk_term_io(device); 147 rc = mdsk_init_io(device, device->block->bp_block, 0, NULL); 148 if (rc == 4) { 149 if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags))) 150 pr_warning("%s: The access mode of a DIAG device " 151 "changed to read-only\n", 152 dev_name(&device->cdev->dev)); 153 rc = 0; 154 } 155 if (rc) 156 pr_warning("%s: DIAG ERP failed with " 157 "rc=%d\n", dev_name(&device->cdev->dev), rc); 158 } 159 160 /* Start a given request at the device. Return zero on success, non-zero 161 * otherwise. */ 162 static int 163 dasd_start_diag(struct dasd_ccw_req * cqr) 164 { 165 struct dasd_device *device; 166 struct dasd_diag_private *private; 167 struct dasd_diag_req *dreq; 168 int rc; 169 170 device = cqr->startdev; 171 if (cqr->retries < 0) { 172 DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p " 173 "- no retry left)", cqr); 174 cqr->status = DASD_CQR_ERROR; 175 return -EIO; 176 } 177 private = (struct dasd_diag_private *) device->private; 178 dreq = (struct dasd_diag_req *) cqr->data; 179 180 private->iob.dev_nr = private->dev_id.devno; 181 private->iob.key = 0; 182 private->iob.flags = DASD_DIAG_RWFLAG_ASYNC; 183 private->iob.block_count = dreq->block_count; 184 private->iob.interrupt_params = (addr_t) cqr; 185 private->iob.bio_list = dreq->bio; 186 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT; 187 188 cqr->startclk = get_clock(); 189 cqr->starttime = jiffies; 190 cqr->retries--; 191 192 rc = dia250(&private->iob, RW_BIO); 193 switch (rc) { 194 case 0: /* Synchronous I/O finished successfully */ 195 cqr->stopclk = get_clock(); 196 cqr->status = DASD_CQR_SUCCESS; 197 /* Indicate to calling function that only a dasd_schedule_bh() 198 and no timer is needed */ 199 rc = -EACCES; 200 break; 201 case 8: /* Asynchronous I/O was started */ 202 cqr->status = DASD_CQR_IN_IO; 203 rc = 0; 204 break; 205 default: /* Error condition */ 206 cqr->status = DASD_CQR_QUEUED; 207 DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc); 208 dasd_diag_erp(device); 209 rc = -EIO; 210 break; 211 } 212 cqr->intrc = rc; 213 return rc; 214 } 215 216 /* Terminate given request at the device. */ 217 static int 218 dasd_diag_term_IO(struct dasd_ccw_req * cqr) 219 { 220 struct dasd_device *device; 221 222 device = cqr->startdev; 223 mdsk_term_io(device); 224 mdsk_init_io(device, device->block->bp_block, 0, NULL); 225 cqr->status = DASD_CQR_CLEAR_PENDING; 226 cqr->stopclk = get_clock(); 227 dasd_schedule_device_bh(device); 228 return 0; 229 } 230 231 /* Handle external interruption. */ 232 static void dasd_ext_handler(unsigned int ext_int_code, 233 unsigned int param32, unsigned long param64) 234 { 235 struct dasd_ccw_req *cqr, *next; 236 struct dasd_device *device; 237 unsigned long long expires; 238 unsigned long flags; 239 addr_t ip; 240 int rc; 241 242 switch (ext_int_code >> 24) { 243 case DASD_DIAG_CODE_31BIT: 244 ip = (addr_t) param32; 245 break; 246 case DASD_DIAG_CODE_64BIT: 247 ip = (addr_t) param64; 248 break; 249 default: 250 return; 251 } 252 kstat_cpu(smp_processor_id()).irqs[EXTINT_DSD]++; 253 if (!ip) { /* no intparm: unsolicited interrupt */ 254 DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited " 255 "interrupt"); 256 return; 257 } 258 cqr = (struct dasd_ccw_req *) ip; 259 device = (struct dasd_device *) cqr->startdev; 260 if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { 261 DBF_DEV_EVENT(DBF_WARNING, device, 262 " magic number of dasd_ccw_req 0x%08X doesn't" 263 " match discipline 0x%08X", 264 cqr->magic, *(int *) (&device->discipline->name)); 265 return; 266 } 267 268 /* get irq lock to modify request queue */ 269 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); 270 271 /* Check for a pending clear operation */ 272 if (cqr->status == DASD_CQR_CLEAR_PENDING) { 273 cqr->status = DASD_CQR_CLEARED; 274 dasd_device_clear_timer(device); 275 dasd_schedule_device_bh(device); 276 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 277 return; 278 } 279 280 cqr->stopclk = get_clock(); 281 282 expires = 0; 283 if ((ext_int_code & 0xff0000) == 0) { 284 cqr->status = DASD_CQR_SUCCESS; 285 /* Start first request on queue if possible -> fast_io. */ 286 if (!list_empty(&device->ccw_queue)) { 287 next = list_entry(device->ccw_queue.next, 288 struct dasd_ccw_req, devlist); 289 if (next->status == DASD_CQR_QUEUED) { 290 rc = dasd_start_diag(next); 291 if (rc == 0) 292 expires = next->expires; 293 } 294 } 295 } else { 296 cqr->status = DASD_CQR_QUEUED; 297 DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for " 298 "request %p was %d (%d retries left)", cqr, 299 (ext_int_code >> 16) & 0xff, cqr->retries); 300 dasd_diag_erp(device); 301 } 302 303 if (expires != 0) 304 dasd_device_set_timer(device, expires); 305 else 306 dasd_device_clear_timer(device); 307 dasd_schedule_device_bh(device); 308 309 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); 310 } 311 312 /* Check whether device can be controlled by DIAG discipline. Return zero on 313 * success, non-zero otherwise. */ 314 static int 315 dasd_diag_check_device(struct dasd_device *device) 316 { 317 struct dasd_block *block; 318 struct dasd_diag_private *private; 319 struct dasd_diag_characteristics *rdc_data; 320 struct dasd_diag_bio bio; 321 struct vtoc_cms_label *label; 322 blocknum_t end_block; 323 unsigned int sb, bsize; 324 int rc; 325 326 private = (struct dasd_diag_private *) device->private; 327 if (private == NULL) { 328 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL); 329 if (private == NULL) { 330 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 331 "Allocating memory for private DASD data " 332 "failed\n"); 333 return -ENOMEM; 334 } 335 ccw_device_get_id(device->cdev, &private->dev_id); 336 device->private = (void *) private; 337 } 338 block = dasd_alloc_block(); 339 if (IS_ERR(block)) { 340 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 341 "could not allocate dasd block structure"); 342 device->private = NULL; 343 kfree(private); 344 return PTR_ERR(block); 345 } 346 device->block = block; 347 block->base = device; 348 349 /* Read Device Characteristics */ 350 rdc_data = (void *) &(private->rdc_data); 351 rdc_data->dev_nr = private->dev_id.devno; 352 rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics); 353 354 rc = diag210((struct diag210 *) rdc_data); 355 if (rc) { 356 DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device " 357 "information (rc=%d)", rc); 358 rc = -EOPNOTSUPP; 359 goto out; 360 } 361 362 device->default_expires = DIAG_TIMEOUT; 363 364 /* Figure out position of label block */ 365 switch (private->rdc_data.vdev_class) { 366 case DEV_CLASS_FBA: 367 private->pt_block = 1; 368 break; 369 case DEV_CLASS_ECKD: 370 private->pt_block = 2; 371 break; 372 default: 373 pr_warning("%s: Device type %d is not supported " 374 "in DIAG mode\n", dev_name(&device->cdev->dev), 375 private->rdc_data.vdev_class); 376 rc = -EOPNOTSUPP; 377 goto out; 378 } 379 380 DBF_DEV_EVENT(DBF_INFO, device, 381 "%04X: %04X on real %04X/%02X", 382 rdc_data->dev_nr, 383 rdc_data->vdev_type, 384 rdc_data->rdev_type, rdc_data->rdev_model); 385 386 /* terminate all outstanding operations */ 387 mdsk_term_io(device); 388 389 /* figure out blocksize of device */ 390 label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL); 391 if (label == NULL) { 392 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 393 "No memory to allocate initialization request"); 394 rc = -ENOMEM; 395 goto out; 396 } 397 rc = 0; 398 end_block = 0; 399 /* try all sizes - needed for ECKD devices */ 400 for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) { 401 mdsk_init_io(device, bsize, 0, &end_block); 402 memset(&bio, 0, sizeof (struct dasd_diag_bio)); 403 bio.type = MDSK_READ_REQ; 404 bio.block_number = private->pt_block + 1; 405 bio.buffer = label; 406 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io)); 407 private->iob.dev_nr = rdc_data->dev_nr; 408 private->iob.key = 0; 409 private->iob.flags = 0; /* do synchronous io */ 410 private->iob.block_count = 1; 411 private->iob.interrupt_params = 0; 412 private->iob.bio_list = &bio; 413 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT; 414 rc = dia250(&private->iob, RW_BIO); 415 if (rc == 3) { 416 pr_warning("%s: A 64-bit DIAG call failed\n", 417 dev_name(&device->cdev->dev)); 418 rc = -EOPNOTSUPP; 419 goto out_label; 420 } 421 mdsk_term_io(device); 422 if (rc == 0) 423 break; 424 } 425 if (bsize > PAGE_SIZE) { 426 pr_warning("%s: Accessing the DASD failed because of an " 427 "incorrect format (rc=%d)\n", 428 dev_name(&device->cdev->dev), rc); 429 rc = -EIO; 430 goto out_label; 431 } 432 /* check for label block */ 433 if (memcmp(label->label_id, DASD_DIAG_CMS1, 434 sizeof(DASD_DIAG_CMS1)) == 0) { 435 /* get formatted blocksize from label block */ 436 bsize = (unsigned int) label->block_size; 437 block->blocks = (unsigned long) label->block_count; 438 } else 439 block->blocks = end_block; 440 block->bp_block = bsize; 441 block->s2b_shift = 0; /* bits to shift 512 to get a block */ 442 for (sb = 512; sb < bsize; sb = sb << 1) 443 block->s2b_shift++; 444 rc = mdsk_init_io(device, block->bp_block, 0, NULL); 445 if (rc && (rc != 4)) { 446 pr_warning("%s: DIAG initialization failed with rc=%d\n", 447 dev_name(&device->cdev->dev), rc); 448 rc = -EIO; 449 } else { 450 if (rc == 4) 451 set_bit(DASD_FLAG_DEVICE_RO, &device->flags); 452 pr_info("%s: New DASD with %ld byte/block, total size %ld " 453 "KB%s\n", dev_name(&device->cdev->dev), 454 (unsigned long) block->bp_block, 455 (unsigned long) (block->blocks << 456 block->s2b_shift) >> 1, 457 (rc == 4) ? ", read-only device" : ""); 458 rc = 0; 459 } 460 out_label: 461 free_page((long) label); 462 out: 463 if (rc) { 464 device->block = NULL; 465 dasd_free_block(block); 466 device->private = NULL; 467 kfree(private); 468 } 469 return rc; 470 } 471 472 /* Fill in virtual disk geometry for device. Return zero on success, non-zero 473 * otherwise. */ 474 static int 475 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo) 476 { 477 if (dasd_check_blocksize(block->bp_block) != 0) 478 return -EINVAL; 479 geo->cylinders = (block->blocks << block->s2b_shift) >> 10; 480 geo->heads = 16; 481 geo->sectors = 128 >> block->s2b_shift; 482 return 0; 483 } 484 485 static dasd_erp_fn_t 486 dasd_diag_erp_action(struct dasd_ccw_req * cqr) 487 { 488 return dasd_default_erp_action; 489 } 490 491 static dasd_erp_fn_t 492 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr) 493 { 494 return dasd_default_erp_postaction; 495 } 496 497 /* Create DASD request from block device request. Return pointer to new 498 * request on success, ERR_PTR otherwise. */ 499 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev, 500 struct dasd_block *block, 501 struct request *req) 502 { 503 struct dasd_ccw_req *cqr; 504 struct dasd_diag_req *dreq; 505 struct dasd_diag_bio *dbio; 506 struct req_iterator iter; 507 struct bio_vec *bv; 508 char *dst; 509 unsigned int count, datasize; 510 sector_t recid, first_rec, last_rec; 511 unsigned int blksize, off; 512 unsigned char rw_cmd; 513 514 if (rq_data_dir(req) == READ) 515 rw_cmd = MDSK_READ_REQ; 516 else if (rq_data_dir(req) == WRITE) 517 rw_cmd = MDSK_WRITE_REQ; 518 else 519 return ERR_PTR(-EINVAL); 520 blksize = block->bp_block; 521 /* Calculate record id of first and last block. */ 522 first_rec = blk_rq_pos(req) >> block->s2b_shift; 523 last_rec = 524 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift; 525 /* Check struct bio and count the number of blocks for the request. */ 526 count = 0; 527 rq_for_each_segment(bv, req, iter) { 528 if (bv->bv_len & (blksize - 1)) 529 /* Fba can only do full blocks. */ 530 return ERR_PTR(-EINVAL); 531 count += bv->bv_len >> (block->s2b_shift + 9); 532 } 533 /* Paranoia. */ 534 if (count != last_rec - first_rec + 1) 535 return ERR_PTR(-EINVAL); 536 /* Build the request */ 537 datasize = sizeof(struct dasd_diag_req) + 538 count*sizeof(struct dasd_diag_bio); 539 cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev); 540 if (IS_ERR(cqr)) 541 return cqr; 542 543 dreq = (struct dasd_diag_req *) cqr->data; 544 dreq->block_count = count; 545 dbio = dreq->bio; 546 recid = first_rec; 547 rq_for_each_segment(bv, req, iter) { 548 dst = page_address(bv->bv_page) + bv->bv_offset; 549 for (off = 0; off < bv->bv_len; off += blksize) { 550 memset(dbio, 0, sizeof (struct dasd_diag_bio)); 551 dbio->type = rw_cmd; 552 dbio->block_number = recid + 1; 553 dbio->buffer = dst; 554 dbio++; 555 dst += blksize; 556 recid++; 557 } 558 } 559 cqr->retries = DIAG_MAX_RETRIES; 560 cqr->buildclk = get_clock(); 561 if (blk_noretry_request(req) || 562 block->base->features & DASD_FEATURE_FAILFAST) 563 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags); 564 cqr->startdev = memdev; 565 cqr->memdev = memdev; 566 cqr->block = block; 567 cqr->expires = memdev->default_expires * HZ; 568 cqr->status = DASD_CQR_FILLED; 569 return cqr; 570 } 571 572 /* Release DASD request. Return non-zero if request was successful, zero 573 * otherwise. */ 574 static int 575 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req) 576 { 577 int status; 578 579 status = cqr->status == DASD_CQR_DONE; 580 dasd_sfree_request(cqr, cqr->memdev); 581 return status; 582 } 583 584 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr) 585 { 586 cqr->status = DASD_CQR_FILLED; 587 }; 588 589 /* Fill in IOCTL data for device. */ 590 static int 591 dasd_diag_fill_info(struct dasd_device * device, 592 struct dasd_information2_t * info) 593 { 594 struct dasd_diag_private *private; 595 596 private = (struct dasd_diag_private *) device->private; 597 info->label_block = (unsigned int) private->pt_block; 598 info->FBA_layout = 1; 599 info->format = DASD_FORMAT_LDL; 600 info->characteristics_size = sizeof (struct dasd_diag_characteristics); 601 memcpy(info->characteristics, 602 &((struct dasd_diag_private *) device->private)->rdc_data, 603 sizeof (struct dasd_diag_characteristics)); 604 info->confdata_size = 0; 605 return 0; 606 } 607 608 static void 609 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req, 610 struct irb *stat) 611 { 612 DBF_DEV_EVENT(DBF_WARNING, device, "%s", 613 "dump sense not available for DIAG data"); 614 } 615 616 static struct dasd_discipline dasd_diag_discipline = { 617 .owner = THIS_MODULE, 618 .name = "DIAG", 619 .ebcname = "DIAG", 620 .max_blocks = DIAG_MAX_BLOCKS, 621 .check_device = dasd_diag_check_device, 622 .verify_path = dasd_generic_verify_path, 623 .fill_geometry = dasd_diag_fill_geometry, 624 .start_IO = dasd_start_diag, 625 .term_IO = dasd_diag_term_IO, 626 .handle_terminated_request = dasd_diag_handle_terminated_request, 627 .erp_action = dasd_diag_erp_action, 628 .erp_postaction = dasd_diag_erp_postaction, 629 .build_cp = dasd_diag_build_cp, 630 .free_cp = dasd_diag_free_cp, 631 .dump_sense = dasd_diag_dump_sense, 632 .fill_info = dasd_diag_fill_info, 633 }; 634 635 static int __init 636 dasd_diag_init(void) 637 { 638 if (!MACHINE_IS_VM) { 639 pr_info("Discipline %s cannot be used without z/VM\n", 640 dasd_diag_discipline.name); 641 return -ENODEV; 642 } 643 ASCEBC(dasd_diag_discipline.ebcname, 4); 644 645 service_subclass_irq_register(); 646 register_external_interrupt(0x2603, dasd_ext_handler); 647 dasd_diag_discipline_pointer = &dasd_diag_discipline; 648 return 0; 649 } 650 651 static void __exit 652 dasd_diag_cleanup(void) 653 { 654 unregister_external_interrupt(0x2603, dasd_ext_handler); 655 service_subclass_irq_unregister(); 656 dasd_diag_discipline_pointer = NULL; 657 } 658 659 module_init(dasd_diag_init); 660 module_exit(dasd_diag_cleanup); 661